JP2007262366A - Curable bio-plastic binder composition and cured product thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable bio-plastic binder composition satisfying both effects unique to the conventional bio-plastic (environmental properties, effective utilization, etc., of natural resources) and effects unique to the conventional curable plastics (energy saving effects and various characteristics such as heat resistance during production) and to provide a cured product thereof. <P>SOLUTION: The curable bio-plastic binder composition is a solid-liquid type composed of starch as a main component in ≥1/2 ratio of the number of active hydroxy groups to the total number of hydroxy groups on the surface of starch grains and a polyisocyanate as a curing agent for cross-linking the starch. The mutual hydroxy groups in the starch molecule are cross-linked with the polyisocyanate to form a three-dimensional network structure. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a curable bioplastic binder composition and a cured product thereof, and in particular, has strong adhesiveness and excellent heat resistance and environmental properties, and can be applied to the field of manufacturing automobile interior parts, interior building materials, and the like. The present invention relates to a solid liquid (solid + liquid) type and one liquid type curable bioplastic binder composition and a cured product thereof.

Conventionally, curable plastic binders used for manufacturing automobile interior parts and bonding interior building materials have been synthesized mainly from petroleum. In general, phenol resins, urethane resins, melamine resins, epoxy resins, unsaturated polyester resins, acrylic resins, and the like are used as curable plastic binders. As these curable plastic binders, there are a two-component type comprising a main agent and a curing agent (a curing agent or a reactive agent), and a one-component type that is cured by air, moisture or heat. An emulsion type curable plastic binder in which they are made water-based has also been proposed. However, conventional curable plastics are organic compounds that are synthesized using petroleum as the main raw material and do not circulate (non-biodegradable) in the global ecosystem, and the use of this compound increases the CO ₂ concentration in the atmosphere. Can be a factor in promoting global warming. Moreover, in the phenol resin and the melamine resin, formaldehyde is used in the manufacturing process and remains in the product. Therefore, the generation of this VOC (volatile organic compound) may cause sick house syndrome in the usage environment.

On the other hand, in recent years, biodegradable resins using natural polymers such as starch and cellulose circulated in the global ecosystem are the main ingredients from the viewpoints of environmental considerations and prevention of global warming due to increased CO ₂ concentration. However, bioplastic binders have been proposed. In addition, all bioplastic binders currently produced or developed from starch, cellulose and the like are thermoplastic. The production method and product include polylactic acid produced by repolymerizing lactic acid produced by saccharifying and fermenting starch, which is a polymer compound, esterified starch and acetylated directly acetylating starch and cellulose. Acetate and the like are known. However, these thermoplastic bioplastic binders may require more energy for production than thermoplastic binders synthesized from petroleum, and there is room for improvement in terms of environmental considerations due to energy saving. In addition, these thermoplastic bioplastic binders have characteristics unique to thermoplastic resins such as being softened and deformed by heat, and are curable in applications such as automotive parts that require a certain degree of heat resistance and heat resistance. There is a point to be improved compared to plastic.

Here, the present inventors can produce effects that are unique to conventional bioplastics (environmental properties and natural resources) if curable plastics can be produced based on starch and cellulose, which are abundantly produced as ecosystem recycling resources. Efforts were made to study whether it would be possible to satisfy both the effective use, etc.) and the effects unique to conventional curable plastics (energy-saving effects during manufacturing and various properties such as heat resistance). As described above, all the bioplastic binders currently commercialized or developed are thermoplastic, but there are techniques described in Patent Document 1 and Patent Document 2 as techniques related to the curable starch composition.
Japanese Patent Laid-Open No. 2004-224887 JP 2005-343939 A

  Patent Document 1 discloses a curable starch composition that is a mixture of starch and a curing agent such as a polyisocyanate compound having a functional group that reacts complementarily with at least one hydroxyl group contained in the starch molecule. ing. Patent Document 2 discloses a curable starch containing a hydroxyl group-containing starch and a polyisocyanate compound and / or a blocked polyisocyanate compound obtained by blocking part or all of the isocyanate groups of the polyisocyanate. A composition is disclosed.

  However, Patent Document 1 and Patent Document 2 both describe that a known starch or a chemically modified starch having a specific substituent is used as the starch of the curable starch composition. There is no consideration about the three-dimensional structure (double helix structure, etc.) or the decrease in reactivity with the curing agent due to hydrogen bonding. That is, both Patent Document 1 and Patent Document 2 give any knowledge and suggestion about means for overcoming the decrease in reactivity with a curing agent or a crosslinking agent caused by a three-dimensional structure peculiar to starch molecules. is not. Furthermore, neither Patent Document 1 nor Patent Document 2 discloses or suggests any curable bioplastic binder mainly composed of cellulose, which is an abundant natural resource circulating in the global ecosystem.

Therefore, the present inventors use starch or cellulose, which is an organic compound that circulates in the global ecosystem, as a main raw material instead of petroleum, which is a main raw material of a conventional curable plastic, thereby reducing the CO ₂ concentration in the atmosphere. The purpose is to suppress the increase and prevent global warming, and to reduce the impact on the human body and the global ecosystem by not containing substances that become VOCs and environmental hormones. As a result of diligent research, the inventors have conceived the present invention for the purpose of suppressing an increase in production energy caused by decomposing and repolymerizing starch and cellulose. That is, the present invention has effects unique to conventional bioplastics (environmental properties, effective utilization of natural resources, etc.) and effects unique to conventional curable plastics (energy saving effects during production, various characteristics such as heat resistance). It is an object of the present invention to provide a curable bioplastic binder composition that satisfies both, and a cured product thereof.

  The solid-liquid type curable bioplastic binder composition according to claim 1 comprises an activated starch as a main ingredient in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is increased from that of non-activated starch, and the activated starch And a polyisocyanate as a curing agent for cross-linking.

  The solid-liquid curable bioplastic binder composition according to claim 2 is characterized in that, in the configuration according to claim 1, the activated starch is gelatinized by hydrothermally heating the starch and then rapidly drying by heat to make it alpha. Activated the hydroxyl group by activating the hydroxyl group by thermally decomposing the starch by thermally decomposing the starch, and activating the hydroxyl group by activating the hydroxyl group with the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the starch particle surface being 1/2 or more. Thermally decomposed starch (such as roasted dextrin) with a ratio of the number of active hydroxyl groups to the number of hydroxyl groups of 1/2 or more, by pulverizing the starch and destroying the crystal structure to activate the hydroxyl groups, Any one or more of amorphous starches in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups was 1/2 or more were used.

  The solid-liquid curable bioplastic binder composition according to claim 3 is the composition according to claim 1, wherein the activated starch is activated by subjecting the hydroxyl group of starch to esterification to activate the starch granules. Esterified starch in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface was 40% or more was used.

  The solid-liquid curable bioplastic binder composition according to claim 4 is gelled by hydrolyzing esterified starch obtained by esterifying a hydroxyl group of starch as the activated starch in the configuration according to claim 1. Alpha-esterified starch whose hydroxyl groups are activated by rapid thermal drying and alphalation later, and esterified starch whose starch hydroxyl groups are esterified by thermal decomposition One or more of the amorphous esterified starch activated by hydroxyl group activation by pulverizing the esterified starch obtained by esterifying the hydroxyl group of starch to destroy the crystal structure was used.

  The one-component curable bioplastic binder composition according to claim 5 is a block of activated starch as a main ingredient in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is increased from that of non-activated starch, and polyisocyanate It consists of blocked isocyanate as a curing agent which is mixed and dispersed with the activated starch in a state blocked with an agent, and which crosslinks the activated starch by room temperature or heating.

  The one-component curable bioplastic binder composition according to claim 6 is the composition according to claim 5, wherein the activated starch is gelatinized by hydrothermally heating the starch and then rapidly heat-dried to become alpha. Activated the hydroxyl group by activating the hydroxyl group by thermally decomposing the starch by thermally decomposing the starch, and activating the hydroxyl group by activating the hydroxyl group with the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the starch particle surface being 1/2 or more. Thermally decomposed starch in which the ratio of the number of active hydroxyl groups in the number of hydroxyl groups is 1/2 or more, the number of active hydroxyl groups in the total number of hydroxyl groups on the surface of the starch granules by activating the hydroxyl groups by impact pulverizing the starch to destroy the crystal structure Any one or more of amorphous starches having a ratio of ½ or more were used.

  The one-component curable bioplastic binder composition according to claim 7 is the composition according to claim 5, wherein the activated starch is activated by subjecting the hydroxyl groups of the starch to esterification to activate the starch granules. Esterified starch in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface was 40% or more was used.

  The one-component curable bioplastic binder composition according to claim 8 is gelled by hydrolyzing esterified starch obtained by esterifying a hydroxyl group of starch as the activated starch in the configuration according to claim 5. Alpha-esterified starch whose hydroxyl groups are activated by rapid thermal drying and alphalation later, and esterified starch whose starch hydroxyl groups are esterified by thermal decomposition One or more of the amorphous esterified starches which activated the hydroxyl group by impact-pulverizing the esterified starch obtained by esterifying the hydroxyl group of starch and destroying the crystal structure to activate the hydroxyl group were used.

  The one-pack type aqueous curable bioplastic binder composition according to claim 9 comprises heating activated starch as a main ingredient in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is increased from that of non-activated starch. As a hardener that crosslinks the activated starch by normal temperature or heating while being mixed with the colloidal starch and emulsified in a state where the colloidal starch formed into a sol or gel is blocked with a polyisocyanate by a blocking agent. The blocked isocyanate.

  The one-pack type aqueous curable bioplastic binder composition according to claim 10 is the composition according to claim 9, wherein the activated starch is gelatinized by hydrothermally heating starch and then rapidly heat-dried to become alpha. The starch by activating the hydroxyl groups by activating the hydroxyl groups and thermally decomposing the starch so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is 1/2 or more. Pyrolyzed starch in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups is ½ or more, activated hydroxyl groups by impact pulverizing starch to destroy the crystal structure, and the active hydroxyl groups in the total number of hydroxyl groups on the surface of the starch granules Using any one or more of amorphous starches whose ratio of number is 1/2 or more, the colloid is made by adding water to the starch to form a sol or gel A starch was prepared.

  The one-pack type aqueous curable bioplastic binder composition according to claim 11 is the composition according to claim 9, wherein the activated starch is activated by subjecting the hydroxyl group of starch to esterification to activate the starch. The colloidal starch was prepared by using an esterified starch in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the grain surface was 40% or more, and hydrating the starch to form a sol or gel.

  The one-pack type aqueous curable bioplastic binder composition according to claim 12 is gelled by hydrolyzing esterified starch obtained by esterifying a hydroxyl group of starch as the activated starch in the configuration according to claim 9. And then heat-decomposing esterified starch by thermally decomposing the esterified starch by esterifying the hydroxyl group of starch. Starch, using one or more of the amorphous esterified starch activated by activating the hydroxyl group by impact pulverizing the esterified starch obtained by esterifying the hydroxyl group of starch to destroy the crystal structure, The colloidal starch was prepared by adding water to the starch to form a sol or gel.

  The one-pack type aqueous curable bioplastic binder composition according to claim 13 is the composition according to any one of claims 9 to 12, wherein the colloidal starch has a PH of 5-9.

  The one-pack type aqueous curable bioplastic binder composition according to claim 14 is the structure according to any one of claims 9 to 12, wherein an oxime blocking agent is used as the blocking agent.

  The curable bioplastic binder composition according to claim 15 is the composition according to any one of claims 1 to 11, wherein the polyisocyanate has a size corresponding to a distance between active hydroxyl groups of the activated starch. Isocyanate was used.

  The solid-liquid curable bioplastic binder composition according to claim 16 cross-links the activated cellulose as a main agent in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface is increased from that of non-activated cellulose, and the activated cellulose. And polyisocyanate as a curing agent.

  The solid-liquid curable bioplastic binder composition according to claim 17 is the composition according to claim 16, wherein the activated cellulose is activated by subjecting the cellulose to etherification to activate the hydroxyl groups and thereby the total number of hydroxyl groups on the cellulose surface. Etherified cellulose having a ratio of the number of active hydroxyl groups in the water to 1/2 or more was used.

  The solid-liquid curable bioplastic binder composition according to claim 18 is the structure according to claim 16, wherein the activated cellulose is subjected to impact pulverization of etherified cellulose obtained by etherifying cellulose to destroy the crystal structure. The amorphous etherified cellulose which activated the hydroxyl group and made the ratio of the number of active hydroxyl groups with respect to the total number of hydroxyl groups on the surface 1/2 or more was used.

  The one-component curable bioplastic binder composition according to claim 19 comprises activated cellulose as a main agent in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface is increased from that of non-activated cellulose, and polyisocyanate by a blocking agent. In the blocked state, it is mixed and dispersed with the activated cellulose, and is composed of blocked isocyanate as a curing agent that crosslinks the activated cellulose by normal temperature or heating.

  The one-component curable bioplastic binder composition according to claim 20 is the composition according to claim 19, wherein the activated cellulose is activated by subjecting the cellulose to etherification to activate the hydroxyl groups and thereby the total number of hydroxyl groups on the cellulose surface. Etherified cellulose having a ratio of the number of active hydroxyl groups in the water to 1/2 or more was used.

  The one-component curable bioplastic binder composition according to claim 21 is the structure according to claim 19, wherein the activated cellulose is subjected to impact pulverization of etherified cellulose obtained by etherifying cellulose to destroy the crystal structure. The amorphous etherified cellulose which activated the hydroxyl group and made the ratio of the number of active hydroxyl groups with respect to the total number of hydroxyl groups on the surface 1/2 or more was used.

  The one-pack type aqueous curable bioplastic binder composition according to claim 22 activates hydroxyl groups by esterifying cellulose to increase the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface compared to that of non-activated cellulose. Colloidal esterified cellulose as colloidal cellulose hydrated or esterified to esterified cellulose as the main agent, and mixed with the colloidal esterified cellulose in the state where polyisocyanate is blocked with a blocking agent. And a blocked isocyanate as a curing agent that crosslinks the esterified cellulose at room temperature or by heating.

  The one-pack type aqueous curable bioplastic binder composition according to claim 23 activates hydroxyl groups by etherification treatment of cellulose, and increases the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface as compared with that of non-activated cellulose. Colloidal etherified cellulose as colloidal cellulose hydrated or gelled by etherified cellulose as the main agent, and mixed with the colloidal etherified cellulose in the state where polyisocyanate is blocked with a blocking agent. And a blocked isocyanate as a curing agent that crosslinks the etherified cellulose by normal temperature or heating.

  The one-pack type aqueous curable bioplastic binder composition according to claim 24 activates the hydroxyl group by pulverizing the etherified cellulose obtained by etherifying the cellulose and destroying the crystal structure to activate the hydroxyl group. Colloidal amorphous etherified cellulose as colloidal cellulose hydrolyzed to amorphous etherified cellulose as the main agent, and colloidal amorphous etherified cellulose in a state where polyisocyanate is blocked with a blocking agent It is mixed and emulsified, and it consists of blocked isocyanate as a curing agent that crosslinks the amorphous etherified cellulose at room temperature or by heating.

  The one-pack type aqueous curable bioplastic binder composition according to claim 25 is the composition according to any one of claims 22 to 24, wherein the colloidal cellulose has a PH of 5-9.

(Block agent only)
The one-pack type aqueous curable bioplastic binder composition according to claim 26 uses the oxime blocking agent as the blocking agent in the structure according to any one of claims 22 to 24.

(Isocyanate size (length) only)
The curable bioplastic binder composition according to claim 27 is the composition according to any one of claims 17 to 23, wherein the polyisocyanate is a polyisocyanate having a size corresponding to a distance between active hydroxyl groups of the cellulose. used.

(Cured product)
The hardened | cured material which concerns on Claim 28 produced | generated by making the curable bioplastic binder composition of any one of Claims 1 thru | or 27 react and harden | cure by normal temperature or a heating.

In the solid-liquid curable bioplastic binder composition according to claim 1, as a starch as a main ingredient, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is increased from that of non-activated starch (such as natural starch). By using activated starch, it is possible to overcome a decrease in reactivity with a polyisocyanate as a curing agent or a crosslinking agent due to a three-dimensional structure (helical structure or crystal structure) peculiar to starch molecules. The starch units or starch subunits) can be crosslinked with high reactivity with polyisocyanates. As a result, the solid-liquid type curable bioplastic binder composition according to claim 1 has an effect specific to the conventional bioplastic (such as environment and effective utilization of natural resources) and an effect specific to the conventional curable plastic ( It can be cured in a short time with a high reaction rate (curing rate) while satisfying both energy-saving effects and heat-resistant properties at the time of manufacture, and in comparison with petroleum-based curable plastic binders. An increase in the CO ₂ concentration in the atmosphere can be suppressed and global warming can be prevented. In addition, a polyisocyanate is used as a curing agent, and a cross-linking reaction between starches is performed while leaving the starch polymer structure (α1 / 4 glycoside bond), so that a three-dimensional network structure can be easily formed, and a plastic bioplastic binder. It can function as a plastic with less manufacturing energy.

  The solid-liquid curable bioplastic binder composition according to claim 2 further uses a physically modified starch such as alpha starch, pyrolyzed starch, amorphous starch, etc., to increase the curing speed and reduce production energy. Can do.

  The solid-liquid curable bioplastic binder composition according to claim 3 can further increase the curing speed and reduce the production energy by using esterified starch which is a chemically modified starch.

The solid-liquid curable bioplastic binder composition according to claim 4 can be further improved by using chemically and physically modified starches such as alpha esterified starch, pyrolyzed esterified starch, and amorphous esterified starch. The curing speed is increased and the production energy can be reduced. Moreover, the flame retardancy is also higher than that of polyurethane using the same polyisocyanate.

  The one-pack type curable bioplastic binder composition according to claim 5 has increased the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface of the starch granules as compared with non-activated starch (such as natural starch) as starch as a main ingredient. By using activated starch, it is possible to overcome a decrease in reactivity with a polyisocyanate as a curing agent or a cross-linking agent due to a three-dimensional structure (helical structure or crystal structure) peculiar to starch molecules. Between starch units or starch subunits) can be crosslinked with high reactivity with polyisocyanates. As a result, the solid-liquid type curable bioplastic binder composition according to claim 5 has an effect peculiar to conventional bioplastics (environmental properties, effective utilization of natural resources, etc.) and an effect peculiar to conventional curable plastics ( While satisfying both the energy saving effect during manufacturing and various characteristics such as heat resistance), it can be reliably cured in a short time with a high reaction rate (curing rate). Moreover, by combining with such characteristics and using a one-component type, it is possible to cope with a pre-treatment of impregnating a binder into a material in hot press molding for manufacturing automobile interior parts.

  The one-component curable bioplastic binder composition according to claim 6 further uses a physically modified starch such as alpha starch, pyrolyzed starch, and amorphous starch to increase the curing speed and reduce production energy. Can do.

  The one-component curable bioplastic binder composition according to claim 7 can further increase the curing speed and reduce the production energy by using chemically modified esterified starch.

  The one-component curable bioplastic binder composition according to claim 8 is further made by using chemically modified and physically modified starch such as alpha esterified starch, pyrolyzed esterified starch, and amorphous esterified starch. The curing speed is increased and the production energy can be reduced.

  The one-pack type aqueous curable bioplastic binder composition according to claim 9 has an increased ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules as a main ingredient starch, compared to non-activated starch (such as natural starch). By using the activated starch, it is possible to overcome a decrease in reactivity with the polyisocyanate as a curing agent or a crosslinking agent due to a three-dimensional structure (helical structure or crystal structure) peculiar to starch molecules. (Between starch units or starch subunits) can be crosslinked with polyisocyanate with high reactivity. As a result, the solid-liquid curable bioplastic binder composition according to claim 9 has an effect peculiar to conventional bioplastics (environmental property, effective utilization of natural resources, etc.) and an effect peculiar to conventional curable plastics ( While satisfying both the energy saving effect during manufacturing and various characteristics such as heat resistance), it can be reliably cured in a short time with a high reaction rate (curing rate). In addition, combined with these characteristics, the one-component type enables the use of pre-impregnation treatment with binders in materials in the hot press molding of automobile interior parts manufacturing, and suppresses the occurrence of VOC because it is aqueous. And the impact on the environment can be kept to a minimum. In addition, by using a sol-form or gelled colloidal starch, the polyisocyanate can be emulsified smoothly and stably without using an emulsifier such as a surfactant.

  The one-component water-based curable bioplastic binder composition according to claim 10 further uses a physically modified starch such as alpha starch, pyrolyzed starch, amorphous starch, etc., thereby further increasing the curing speed and reducing production energy. be able to.

  The one-pack type aqueous curable bioplastic binder composition according to claim 11 can further increase the curing speed and reduce the production energy by using the chemically modified esterified starch.

  The one-pack type aqueous curable bioplastic binder composition according to claim 12 further uses a chemically modified and physically modified starch such as an alpha esterified starch, a pyrolyzed esterified starch, and an amorphous esterified starch. The curing speed is further increased and the production energy can be reduced.

  In the one-pack type aqueous curable bioplastic binder composition according to the thirteenth aspect of the invention, the emulsion is stabilized by further adjusting the PH of the colloidal starch within the range of 5 to 9.

  The one-part aqueous curable bioplastic binder composition according to claim 14 can further obtain an emulsion in which colloidal starch and blocked isocyanate are uniformly dispersed by using an oxime blocking agent.

  The one-pack type aqueous curable bioplastic binder composition according to claim 15 can further efficiently crosslink between active hydroxyl groups of starch with a polyisocyanate having a predetermined size corresponding to the distance between active hydroxyl groups of activated starch. .

The solid-liquid curable bioplastic binder composition according to claim 16 has an activity in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is increased as compared with non-activated cellulose (such as natural cellulose) as cellulose as a main ingredient. By using a modified cellulose, it is possible to overcome a decrease in reactivity with polyisocyanate as a curing agent or a crosslinking agent due to a structure unique to cellulose molecules (hydrogen bonding between molecules), etc. And can be cross-linked by polyisocyanate. As a result, the solid-liquid curable bioplastic binder composition according to claim 16 has an effect specific to conventional bioplastics (such as environmental properties and effective utilization of natural resources) and an effect specific to conventional curable plastics ( It is an organic compound that can be cured in a short period of time with a high reaction rate (curing rate) while satisfying both energy-saving effects during manufacturing and heat resistance, etc. By using cellulose as the main agent, it is possible to suppress an increase in the CO ₂ concentration in the atmosphere and prevent global warming compared to petroleum-based curable plastic binders. In addition, a polyisocyanate is used as a curing agent, and a three-dimensional network structure is easily formed by performing a cross-linking reaction between celluloses while leaving the macromolecular structure of cellulose (β1 · 4 glycoside bonds), and a plastic bioplastic binder. Functions as plastic can be achieved with less manufacturing energy.

  The solid-liquid curable bioplastic binder composition according to claim 17 can further increase the curing speed and reduce the production energy by using etherified cellulose which is a cellulose derivative.

  The solid-liquid curable bioplastic binder composition according to claim 18 can further increase the curing rate and reduce the production energy by using amorphous etherified cellulose.

  The one-component curable bioplastic binder composition according to claim 19 has an activity in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is increased as compared with non-activated cellulose (such as natural cellulose) as cellulose as a main ingredient. By using a modified cellulose, it is possible to overcome a decrease in reactivity with polyisocyanate as a curing agent or a crosslinking agent due to a structure unique to cellulose molecules (hydrogen bonding between molecules), etc. And can be cross-linked by polyisocyanate. As a result, the solid-liquid curable bioplastic binder composition according to claim 19 has an effect peculiar to conventional bioplastics (environmental properties, effective utilization of natural resources, etc.) and an effect peculiar to conventional curable plastics ( While satisfying both the energy saving effect during manufacturing and various characteristics such as heat resistance), it can be reliably cured in a short time with a high reaction rate (curing rate). Moreover, by combining with such characteristics and using a one-component type, it is possible to cope with a pre-treatment of impregnating a binder into a material in hot press molding for manufacturing automobile interior parts.

  The one-component curable bioplastic binder composition according to the twentieth aspect further uses etherified cellulose, which is an active-treated cellulose, so that the curing speed can be further increased and the production energy can be reduced.

  The one-component curable bioplastic binder composition according to claim 21 can further increase the curing speed and reduce the production energy by using amorphous etherified cellulose starch.

  The one-pack type aqueous curable bioplastic binder composition according to claim 22 has an increased ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface of cellulose as compared with non-activated cellulose (such as natural cellulose). By using activated cellulose, it is possible to overcome a decrease in reactivity with a polyisocyanate as a curing agent or a crosslinking agent due to a structure (hydrogen bonding between molecules) peculiar to cellulose molecules. It is reactive and can be crosslinked with polyisocyanates. As a result, the solid-liquid type curable bioplastic binder composition according to claim 22 has an effect peculiar to conventional bioplastics (environmental property, effective utilization of natural resources, etc.) and an effect peculiar to conventional curable plastics ( While satisfying both the energy saving effect during manufacturing and various characteristics such as heat resistance), it can be reliably cured in a short time with a high reaction rate (curing rate). In addition, combined with these characteristics, the one-component type enables the use of pre-impregnation treatment with binders in materials in the hot press molding of automobile interior parts manufacturing, and suppresses the occurrence of VOC because it is aqueous. And the impact on the environment can be kept to a minimum. In addition, by using colloidal cellulose that has been solated or gelled, polyisocyanate can be emulsified smoothly and stably without using an emulsifier such as a surfactant.

  The one-pack type aqueous curable bioplastic binder composition according to the twenty-third aspect can further increase the curing rate and reduce the production energy by using etherified cellulose.

  The one-pack type aqueous curable bioplastic binder composition according to claim 24 can further increase the curing rate and reduce the production energy by using amorphous esterified cellulose.

  In the curable bioplastic binder composition according to claim 25, the emulsion is further stabilized by adjusting the PH of the colloidal starch in the range of 5 to 9.

  The curable bioplastic binder composition according to claim 26 can further obtain an emulsion in which colloidal starch and blocked isocyanate are uniformly dispersed by using an oxime blocking agent.

  In the curable bioplastic binder composition according to claim 27, the active hydroxyl groups of starch can be efficiently crosslinked with a polyisocyanate having a predetermined size corresponding to the distance between active hydroxyl groups of cellulose.

  The cured product according to claim 28 exhibits specific effects such as heat resistance and environmental properties due to the curable bioplastic binder composition according to any one of claims 1 to 27.

  Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as an embodiment) will be described.

Embodiment 1
The curable plastic binder composition and cured product thereof according to Embodiment 1 will be described. The curable plastic binder composition according to Embodiment 1 is a solid (starch) + liquid (polyisocyanate) type consisting of starch as a main agent and polyisocyanate as a curing agent or a crosslinking agent, that is, a solid-liquid type. It is a room temperature or thermosetting bioplastic binder composition. As the starch of the present invention, an activated starch is used in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is increased from that of non-activated starch such as natural starch. That is, non-activated starch such as natural starch has three hydroxyl groups for each amylose unit of each starch molecule, but only one of them is an active hydroxyl group, and the remaining two are (hydrogen bonds and steric hindrances). It is an inactive hydroxyl group that has lost its activity due to, for example. Therefore, in the non-activated starch such as natural starch, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is about 1/3 as usual. On the other hand, in the present invention, as starch as a main ingredient, non-activated starch is activated by physical modification, chemical modification, or a combination of chemical modification and physical modification, so that the total number of hydroxyl groups on the surface of starch granules is increased. Starch (referred to as “activated starch” in the present application document) in which the ratio of the number of active hydroxyl groups is increased from the case of non-activated starch (1/3) is used. Specifically, in the present invention, the ratio of the active hydroxyl group in the activated starch is 40% or more (in the case of chemically modified starch) or 1/2 or more (physically modified starch and a combination of chemically modified and physically modified) as the main agent. Activated starch as used in the case of physical / chemically modified starch according to As long as that is the case, as the activated starch of the present invention, any starch such as natural starch or modified starch obtained by physically or chemically modifying natural starch can be used. In addition, at present, starch is only natural starch that exists in nature, but if synthetic starch (not modified starch) having an equivalent composition can be produced by chemical synthesis, such synthetic starch can also be used as starch. . Here, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is difficult to measure accurately, but the reaction rate when starch as a main agent and polyisocyanate as a curing agent are mixed and reacted. By comparing these, the ratio of active hydroxyl groups can be estimated. For example, the reaction rate Y when activated starch and polyisocyanate are reacted is compared with the reaction rate X when non-activated starch (the ratio of the number of active hydroxyl groups is 1/3) and polyisocyanate is reacted. If it is doubled, it can be estimated that the ratio of active hydroxyl groups on the surface of starch granules has doubled. In this case, the ratio of active hydroxyl groups on the surface of starch granules of activated starch is 1/3 * 2 = 2/3. It can be estimated that Similarly, the reaction rate Y when activated starch and polyisocyanate are reacted is 1.5 times (3/2 times) the reaction rate X when non-activated starch and polyisocyanate are reacted. If it is, it can be estimated that the ratio of active hydroxyl groups on the surface of starch granules is 1.5 times (3/2 times). In this case, the ratio of active hydroxyl groups on the surface of starch granules of activated starch is 1/3. * It can be estimated that 3/2 = 1/2.

Hereinafter, the starch as the main agent used in the present invention will be described. Starch is a storage polysaccharide of higher plants such as tapioca, potato, corn, wheat, sweet potato, rice and sago, and consists of amylose (amylose molecule) and amylopectin (amylopectin molecule). The proportion of amylose and amylopectin varies depending on the starch species, but is usually about 20-25% for amylose and about 75-80% for amylopectin. Some glutinous rice, glutinous corn (glutinous seeds), etc., contain about 100% amylopectin and hardly contain amylose. Amylose is a polymer (polysaccharide) in which D-glucose is linearly linked by α-1,4 glycosidic bonds and depends on the plant species, but generally has an average degree of polymerization of about 30 to 3000 and an average molecular weight of tens of thousands to It is said to be several hundred thousand, and has one non-reducing end and one reducing end. Some amyloses are branched by α-1,6 glycosidic bonds, but the ratio is very small. Amylose has a double helix (double-stranded helix) structure in water and is uniformly dispersed in water. Further, the inside of the spiral structure is a hydrophobic environment, and the outside is hydrophilic. Furthermore, amylose has a strong interaction with many compounds regardless of polarity or nonpolarity, and forms a complex with these compounds. Furthermore, amylose is regenerated by performing a treatment such as dissolving in a solvent and adding a non-solvent, so that the molecular chain has a single-helix (single-stranded helix) structure such as V-amylose. . Natural starch also contains amylose having a single-stranded helix (single-stranded helix) structure. The general structural formula (partial formula) of the amylose molecule is shown below.

On the other hand, amylopectin is a polymer (polysaccharide) having a three-dimensional structure in which a linear molecule of amylose is branched and polymerized by α-1,6 glycosidic bonds and generally has an average degree of polymerization of about 6,000 to 280,000. It is also said that the average molecular weight is about 160,000 to 6 million, and a relatively short α-1,4 chain of glucose (one unit of about 20-30 glucose residues) is separated from another glucose chain by an α-1,6 glycosidic bond. Are connected. The ratio of α-1,6 glycosidic bonds to all glycosidic bonds is about 4%, which is one per glucose residue unit 25. It is said that amylopectin has a clustered cluster structure, and most of them have a double helix (double helix) structure. The general structural formula (partial formula) of the amylopectin molecule is shown below.

  The starch granules are chemically mixed with the linear amylose and the branched (tufted) amylopectin as described above, and physically the crystalline part (single-helix structure part and double-helix structure part) and It is a heterogeneous substance containing an amorphous part. Such amylose and amylopectin are hydroxyl groups (active hydroxyl groups) that are active due to the three-dimensional structure (steric hindrance) of the crystal part in addition to intermolecular and intramolecular bonds through hydrogen bonding via hydroxyl groups (hydroxyl groups). In general natural starch, as described above, the number of active hydroxyl groups is about 1/3 of the total hydroxyl groups, and about 2/3 of the total hydroxyl groups are active. It has an inactive hydroxyl group. Therefore, if the natural starch is used as it is, the number of active hydroxyl groups that react with the isocyanate group (N = C = O) of the polyisocyanate as a curing agent or a crosslinking agent is not sufficient, and particularly the reactivity or curing at room temperature or the like. Not enough in terms of sex. In addition, in FIG. 1, the structure of normal natural starch is shown typically. As shown in FIG. 1, ordinary natural starch has a plurality of small subunits (12 in FIG. 1) linked to a single-stranded amylose in which double-helix amylopectin is branched and connected. Thus, it can be considered that the entire unit has a radial tufted (cluster) structure. As described above, in normal natural starch, hydroxyl groups are hydrogen-bonded between subunits in starch granules, or hydroxyl groups are hydrogen-bonded between starch grains (between units). is decreasing.

  Therefore, the present inventors have made especially the crystal structure of ordinary natural starch by physical modification, chemical modification, or a combination of chemical modification and physical modification (more preferably, physical modification or a combination of chemical modification and physical modification). The ratio of the number of active hydroxyl groups on the starch granule surface is increased compared to the case of ordinary non-activated starch by releasing hydrogen bonds between molecules by breaking or physical modification of The number of hydroxyl groups is improved to 40% or more, and in the case of physical modification, it is improved to be 1/2 or more of the total number of hydroxyl groups. That is, the starches of Embodiment 1 and the following Embodiments 2 to 24 are prepared such that the number of active hydroxyl groups on the surface of starch granules is 40% or more or 1/2 or more of the total number of hydroxyl groups on the surface of starch granules. Activated starch. The active hydroxyl group means a hydroxyl group that has not lost its reactivity due to hydrogen bonding between hydroxyl groups or steric hindrance of starch molecules. Here, in Embodiment 1, activated starch prepared by physical modification or the like so that the number of active hydroxyl groups on the surface of starch granules is 40% or more or 1/2 or more of the total number of hydroxyl groups on the surface of starch granules. Although it is preferable to use it, it is possible to selectively use natural starch in which the number of active hydroxyl groups on the surface of starch granules is 40% or more or 1/2 or more of the total number of hydroxyl groups on the surface of starch granules.

Next, the polyisocyanate that reacts with the hydroxyl groups of the starch to crosslink starch molecules (between units and / or subunits) will be described. The polyisocyanate is a compound represented by the general formula CON-R-NCO. In the first embodiment, tolylene diisocyanate (TDI) and diphenylmethane diisocyanate (MDI) are preferably used as aromatic isocyanates with high reactivity. Can be used. The general formulas of TDI and MDI are shown below. (Displayed in the order of 2,4′-TDI, 2,6′-TDI, 4,4′-MDI, 2,4′-MDI, and 2,2′-MDI.)

  However, besides these, aromatic isocyanates such as xylylene diisocyanate (XDI), naphthalene diisocyanate (NDI), tetramethylene xylylene diisocyanate (TMXDI), isophorone diisocyanate (IPDI), hydrogenated (hydrogenated) MDI, dicyclohexyl Various organics such as alicyclic isocyanates such as methane diisocyanate (H12MDI), hydrogenated XDI (H6XDI), aliphatic isocyanates such as hexamethylene diisocyanate (HDI), dimer acid diisocyanate (DDI), norbornene diisocyanate (NBDI), etc. Use polyisocyanates, use these biuret compounds, isocyanurates, modified carbodiimides, or use mixtures of these. It can be.

The curable plastic binder composition according to Embodiment 1 configured as described above is cured by mixing the activated starch as a main component and polyisocyanate as a curing agent. For example, with respect to a predetermined part by weight of tapioca starch as starch, a mixture obtained by mixing TDI and MDI as a polyisocyanate at a ratio of 1: 1 is added in the same weight part as the starch and mixed. Then, a plurality of active hydroxyl groups (OH) on the surface of the starch granules are urethane-bonded (NHCOO) with the isocyanate groups (NCO) of the polyisocyanate at room temperature, so that the starch molecules are crosslinked by the polyisocyanate to form a three-dimensional network structure. And harden. Further heating from this state further softens the starch granules and further activates the hydroxyl groups on the surface, thereby further promoting the urethane bond reaction, and the curable resin molding as the final cured product can be quickly and efficiently produced. Generate automatically. In addition, the heating temperature at this time shall be the range of 100 degreeC or more and 200 degreeC, for example, can be 150 degreeC. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 1 is shown in FIG. As shown in FIG. 2, in the first embodiment, between active hydroxyl groups of radial tufted units (consisting of a large number of tufted subunits) showing the general structure (solid) of starch granules (crystals), Polyisocyanate (liquid) will be crosslinked. In the figure, —OH ^* represents an active hydroxyl group.

Example 1
Example 1 is an example corresponding to the first embodiment. In Example 1, 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to and mixed with 50 parts by weight of tapioca starch as the main agent, and 150 Heated at ° C. Thereby, the molecule | numerator of tapioca starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. The reaction formula at this time is represented by the following formula (1).
2 St-OH + OCN-R-NCO → St-O-OCHN-R-NHCO-O-St (1)
In the formula, “St” represents a starch molecule (Starch).

Embodiment 2
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 2 will be described. The curable plastic binder composition according to Embodiment 2 uses modified starch, particularly physical modified starch, as the starch as the main agent in Embodiment 1. Specifically, alpha starch is used as the main agent. This alpha starch is obtained by hydrolyzing natural starch and gelling, followed by rapid thermal drying, alphalation, fine pulverization to activate the hydroxyl groups, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules. Is 1/2 or more. In this way, by heating to natural starch, gelling, and rapid thermal drying and pulverization, the α1,6 glycoside bond of the starch molecule is mainly cleaved to reduce the starch molecule, and these reduced starch molecules are regenerated. By combining, alpha starch having an increased number of active hydroxyl groups on the surface of the starch granules is produced. The curable plastic binder composition according to the second embodiment is cured by mixing the alpha starch as a main agent and the same polyisocyanate as in the first embodiment as a curing agent. For example, with respect to a predetermined part by weight of corn starch as starch, a mixture obtained by adding a predetermined part by weight of water and mixing and stirring is dropped on a twin drum dryer heated to a predetermined temperature, and rapidly gelled and thermally dried. An alpha starch is prepared by grinding to a particle size (eg, 250 μm). The heating temperature at this time is in a range from 120 ° C. to 180 ° C., and can be set to 150 ° C., for example. Then, with respect to a predetermined part by weight of the alpha starch, a mixture obtained by mixing TDI and MDI as a polyisocyanate at a ratio of 1: 1 is added in the same amount by weight as the alpha starch and mixed. Then, in the same manner as in the first embodiment, a plurality of active hydroxyl groups on the surface of the alpha starch granules and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, alpha starch granules have a higher number of active hydroxyl groups and higher reactivity than ordinary natural starch granules. Further, by further heating from this state, as in Embodiment 1, the alpha starch granules are softened, the hydroxyl groups are further activated, and the reaction is promoted. The heating temperature at this time is in the range from 100 ° C. to 200 ° C., for example, 150 ° C., as in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 2 is shown in FIG. As shown in FIG. 3, in the second embodiment, the polyisocyanate crosslinks between active hydroxyl groups of tuft-like subunits (due to physical modification) in starch granules or starch structures (alpha starch granules). . In the figure, —OH ^* represents an active hydroxyl group.

Example 2
Example 2 is an example corresponding to the second embodiment. In Example 2, 100 parts by weight of water was added to 90 parts by weight of corn starch as a main ingredient, and the mixture was stirred and dropped onto a twin drum dryer heated to 150 ° C., and rapidly gelled and thermally dried. Thereafter, the starch was ground to a particle size of less than 250 μm to prepare an alpha starch. Further, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent is added to and mixed with 50 parts by weight of alpha starch as a main ingredient, and the mixture is mixed at 150 ° C. Heated. As a result, the molecules of the alpha starch were crosslinked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (1).

Embodiment 3
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 3 will be described. The curable plastic binder composition according to Embodiment 3 is obtained by using physically modified starch (physically modified starch) as the starch as the main agent in Embodiment 1, as in Embodiment 2. Specifically, pyrolyzed starch is used as the main agent. This pyrolyzed starch is one in which the hydroxyl groups are activated by pyrolyzing natural starch and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is ½ or more. As the starch, roasted dextrin and the like can be suitably used. Thus, by thermally decomposing natural starch, the α1,4 glycoside bond and α1,6 glycoside bond of the starch molecule are randomly cleaved to reduce the molecular weight of the starch molecule, thereby increasing the number of active hydroxyl groups. Degraded starch (such as dextrin) is produced. The curable plastic binder composition according to the third embodiment is cured by mixing the pyrolytic starch as a main agent and the same polyisocyanate as in the first embodiment as a curing agent. For example, corn starch as starch is put into a rotary kiln of a predetermined size heated to a predetermined temperature, and the pyrolyzed starch is prepared by feeding the rotary kiln at a predetermined discharge speed at a predetermined discharge speed and thermally decomposing it. To do. The heating temperature at this time is in the range of 100 ° C. to 250 ° C., and particularly preferably 180 ° C. The rotational speed of the rotary kiln is preferably in the range of 1 to 20 rpm, and the feed speed (discharge speed) is preferably in the range of 10 cm to 40 cm per minute, particularly preferably 30 cm per minute. Then, a mixture obtained by mixing TDI and MDI as a polyisocyanate at a ratio of 1: 1 is added to the predetermined weight part of the pyrolyzed starch by the same weight part as the pyrolyzed starch and mixed. Then, in the same manner as in the first embodiment, the plurality of active hydroxyl groups on the surface of the pyrolyzed starch granules and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, the pyrolyzed starch granules have a higher number of active hydroxyl groups and higher reactivity than ordinary natural starch granules. Further, by further heating from this state, as in the first embodiment, the pyrolyzed starch granules are softened, the hydroxyl groups are further activated, and the reaction is promoted. The heating temperature at this time is in the range from 100 ° C. to 200 ° C., for example, 150 ° C., as in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 3 is shown in FIG. As shown in FIG. 4, in the third embodiment, polyisocyanate crosslinks between active hydroxyl groups of tufted subunits (by physical modification) in starch granules or starch structures (pyrolyzed starch granules). Become. In the figure, —OH ^* represents an active hydroxyl group.

Example 3
Example 3 is an example corresponding to the third embodiment. In Example 3, corn starch as the main agent was charged into a rotary kiln (made by KS Material) having a length of 1.8 m and a diameter of 0.2 m heated to 180 ° C., and the rotational speed of the rotary kiln was 1 to 20 rpm. A discharge rate of 30 cm / min was sent and pyrolyzed to prepare pyrolyzed starch. In addition, 50 parts by weight of a mixture of TDI and MDI as a curing agent in a ratio of 1: 1 (50:50 parts by weight) was added to 50 parts by weight of the pyrolyzed starch as the main ingredient, and mixed at 150 ° C. And heated. Thereby, the molecule | numerator of the pyrolysis starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. The reaction formula at this time is also expressed by the above formula (1).

Embodiment 4
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 4 will be described. The curable plastic binder composition according to Embodiment 4 is obtained by using physically modified starch in the same manner as in Embodiments 2 and 3 as the starch as the main agent in Embodiment 1. Specifically, amorphous starch is used as the main agent. This amorphous starch is produced by impact pulverizing natural starch with a ball mill or the like to destroy the crystal structure (double helix structure, etc.), thereby activating the hydroxyl groups and determining the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules. For example, ball mill-treated starch can be suitably used as the amorphous starch. Thus, by destroying the crystal structure of natural starch by impact pulverization, mainly the hydrogen bonds between the hydroxyl groups at the C2 and C3 positions of adjacent α-glucose in the starch particles are weakened, and the amorphous starch in which the hydroxyl groups are activated is obtained. Generated. The curable plastic binder composition according to Embodiment 3 is cured by mixing the amorphous starch as a main agent and the same polyisocyanate as in Embodiment 1 as a curing agent. For example, corn starch as starch is charged into a dry ball mill, a predetermined amount of alumina balls having a predetermined diameter is charged, the dry ball mill is operated at a predetermined rotation speed for a predetermined time, and corn starch is impact pulverized to prepare amorphous starch. At this time, the diameter of the alumina ball is set in the range of 10 to 100 mm, the input amount is set in the range of 1 to 3 t, the rotational speed of the dry ball mill is set in the range of 30 to 100 rpm, and the operation time is 4 to 8 hours. It is preferable to set it as the range. And with respect to the predetermined weight part of this amorphous starch, only the same weight part as the said amorphous starch is added and mixed the mixture which mixed TDI and MDI as a polyisocyanate in the ratio of 1: 1. Then, in the same manner as in the first embodiment, the plurality of active hydroxyl groups on the surface of the amorphous starch granules and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, the amorphous starch granules have a higher number of active hydroxyl groups than ordinary natural starch granules, and the particles are 10 μm or less, so that the dispersibility is good and the reactivity is very high. Further, by further heating from this state, the amorphous starch granules are softened and the hydroxyl groups are further activated and the reaction is promoted as in the first embodiment. The heating temperature at this time is in the range from 100 ° C. to 200 ° C., for example 150 ° C., as in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 4 is shown in FIG. As shown in FIG. 5, in the fourth embodiment, the active hydroxyl group of a radial tuft-like unit (consisting of a number of tuft-like subunits) is shown to show the general structure (solid) of amorphous starch granules (non-crystal). The polyisocyanate (liquid) is crosslinked in the space. In the figure, —OH ^* represents an active hydroxyl group.

Example 4
Example 4 is an example corresponding to the fourth embodiment. In Example 4, corn starch as a main ingredient was introduced into a dry ball mill (1.2 ton made by Tokai clay industry) and alumina balls (diameter 10 to 100 mm) were introduced in an amount ranging from 1 t to 3 t. Operation was carried out at a rotational speed of 30 to 100 rpm for 4 to 8 hours, and corn starch was impact pulverized to prepare amorphous starch. Further, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to and mixed with 50 parts by weight of amorphous starch as a main ingredient, and the mixture was mixed at 150 ° C. Heated. As a result, the molecules of amorphous starch were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (1).

  As described in Embodiments 2 to 4, when physically modified starch such as alpha starch, pyrolyzed starch, amorphous starch or the like is used as the activated starch as the main agent, the preparation work is simplified, while starch is used. By physically modifying, i.e., breaking or weakening the helical structure of the starch molecule to open (break) or weaken the hydrogen bonds within and / or between the molecules of the starch molecule, As a result, the number of active hydroxyl groups on the surface of the starch granules can be increased to a ratio of 1/2 or more of the total number of hydroxyl groups. And the activated starch (physically modified starch) having increased the number of active hydroxyl groups on the surface of the starch granules in this way is highly reactive with the polyisocyanate, and is effectively cross-linked by the polyisocyanate, quickly, and The desired cured product can be produced stably. At this time, as described above, it is preferable from the viewpoint of early curing that the starch and polyisocyanate are mixed and heated, but since the reactivity of the activated starch is sufficiently enhanced as described above, Even if not, the curing reaction proceeds smoothly at room temperature, and a cured product can be generated stably. Here, in Embodiments 2 to 4, it is preferable to use a polyisocyanate having a predetermined size in order to crosslink between physically modified starches. For example, various polyisocyanates have a size corresponding to the structure represented by the general formula (chemical structural formula), but selectively select a polyisocyanate having a size corresponding to the interval between active hydroxyl groups of starch used as the main agent. By using it, the crosslinking efficiency can be dramatically improved.

  Specifically, as the polyisocyanate, when the starch subjected to physical modification by hydroxyl group activation such as ball mill treatment is used, the physical modified starch (fiber period: 2.8 to 5.6 mm (single amylose) Between helixes), 8 to 10.4 mm (between the single helix centers of amylose), 1.4 to 2.8 mm (between the double helixes of amylopectin), 2.8 to 5.6 mm (between the double helix centers of amylopectin) It is preferable to use a polyisocyanate having a size corresponding to the distance between the intramolecular or intermolecular active hydroxyl groups. More specifically, the size of the polyisocyanate is not constant due to molecular vibration or the like, but the size of the polyisocyanate in this case is preferably in the range of 10 to 60 mm. Here, in the case of modified starch, since the intermolecular distance is larger than that of unmodified starch such as natural starch, the size of the polyisocyanate for modified starch is larger in the above range (for example, The range is preferably 30 to 60 cm, and in the case of an unmodified starch such as natural starch, the range on the smaller side (for example, 10 to 30 cm) of the above range is preferable. Thus, the polyisocyanate can mainly crosslink between the subunits of the starch structure or between the amylose or amylopectin units of the modified starch.

Embodiment 5
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 5 will be described. The curable plastic binder composition according to Embodiment 5 uses a modified starch, particularly a chemically modified starch, as the starch as the main agent in Embodiment 1. Specifically, esterified starch is used as the main agent. This esterified starch is a chemically modified starch or starch derivative in which the hydroxyl group of natural starch is activated by esterification to activate the hydroxyl group, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 40% or more. It is. Examples of such esterified (R′CO—) starch include acetic acid esterified (CH ₃ CO—) acetic acid starch ester, phosphoric acid esterified ((NaO) ₂ PO—) phosphoric acid starch, and starch succinate. Starch organic acid esters such as starch, sulfate sulfate (NaSO _3- ) starch sulfate, starch inorganic acid esters such as starch nitrate, and the like can be used. Thus, by esterifying the hydroxyl group of natural starch, the number of active hydroxyl groups on the surface of the starch granules is increased and esterified starch having a carboxylic acid group as a functional group is produced. The curable plastic binder composition according to Embodiment 5 is cured by mixing the esterified starch as a main agent and the same polyisocyanate as in Embodiment 1 as a curing agent. For example, acetyl tapioca starch is prepared by adding a predetermined part by weight of acetic anhydride to a predetermined part by weight of tapioca starch as starch, heating at a predetermined temperature for a predetermined time, esterifying the hydroxyl group of tapioca starch, washing and drying. To do. And with respect to the predetermined weight part of this esterified starch, only the same weight part as the said esterified starch is added and mixed with the mixture which mixed TDI and MDI as a polyisocyanate in the ratio of 1: 1. Then, in the same manner as in the first embodiment, the plurality of active hydroxyl groups on the esterified starch particle surface and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, esterified starch granules have a higher number of active hydroxyl groups and higher reactivity than ordinary natural starch granules. Further, by further heating from this state, as in the first embodiment, the esterified starch granules are softened, the hydroxyl groups are further activated, and the reaction is promoted. The heating temperature at this time is in the range from 100 ° C. to 200 ° C., for example 150 ° C., as in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 5 is shown in FIG. As shown in FIG. 6, in the fifth embodiment, between the active hydroxyl groups of radial tufted units (consisting of a number of tufted subunits) showing the general structure (solid) of esterified starch granules (crystals) The polyisocyanate (liquid) is crosslinked. In the figure, —OH ^* represents an active hydroxyl group.

Example 5
Example 5 is an example corresponding to the fifth embodiment. In Example 5, 50 parts by weight of acetic anhydride is added to 10 parts by weight of tapioca starch as the main agent and heated at a heating temperature of 100 ° C. for 12 hours, thereby esterifying the hydroxyl group of tapioca starch, and then washing and drying. Acetyl tapioca starch was prepared. In addition, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to 50 parts by weight of acetyl tapioca starch as the main ingredient, and the mixture was mixed at 150 ° C. And heated. Thereby, the molecule | numerator of acetyl tapioca starch was bridge | crosslinked by polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. The reaction formula at this time is also expressed by the above formula (1).

Embodiment 6
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 6 will be described. The curable plastic binder composition according to Embodiment 6 is the same as that of Embodiment 1 except that the esterified starch (chemically modified starch) of Embodiment 5 is used as the starch as the main agent. Alpha-esterified starch as an activated starch further physically modified in the same manner as in the case of physically modified starch) is used. Specifically, this alpha-esterified starch is obtained by hydrolyzing esterified starch obtained by esterifying the hydroxyl group of natural starch to gel, and then rapidly heat-drying to activate the hydroxyl group. Thus, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is set to 1/2 or more. Of course, since the alpha-esterified starch used in Embodiment 6 is a product obtained by further activating the activated starch (double activated product), the alpha starch of Embodiment 2 and that of Embodiment 5 are used. Compared with esterified starch, the proportion of active hydroxyl groups can be further increased, and the curing reactivity can be further improved. As described above, the esterified starch obtained by esterifying the hydroxyl group of natural starch as in the fifth embodiment is further converted into an alpha starch as in the second embodiment, whereby α1,6 glycosides of starch are mainly used. The bond is cut to lower the esterified starch molecules, and the esterified starch molecules having a reduced molecular weight are recombined to produce an alpha-esterified starch in which the number of active hydroxyl groups on the surface of the starch granules is further increased.

The curable plastic binder composition according to Embodiment 6 is cured by mixing such an alpha-esterified starch as a main agent and the same polyisocyanate as in Embodiment 1 as a curing agent. For example, acetyl tapioca starch is prepared by adding a predetermined part by weight of acetic anhydride to a predetermined part by weight of tapioca starch as starch, heating at a predetermined temperature for a predetermined time, esterifying the hydroxyl group of tapioca starch, washing and drying. To do. Next, with respect to a predetermined part by weight of the acetyl tapioca starch, a predetermined part by weight of water added and mixed and stirred is dripped onto a twin drum dryer heated to a predetermined temperature, and rapidly gelled and thermally dried. Grind to less than diameter to prepare alpha starch. Conditions such as the heating temperature at this time can be the same as those in the second and fifth embodiments. In addition, the blending ratio of acetyl tapioca starch to water at this time is about 1 order (one digit) or less less than that in the second embodiment. Then, with respect to a predetermined part by weight of the alpha esterified starch, a mixture obtained by mixing TDI and MDI as a polyisocyanate at a ratio of 1: 1 is added in the same amount by weight as the alpha esterified starch and mixed. Then, in the same manner as in Embodiment 1, a plurality of active hydroxyl groups on the surface of the alpha-esterified starch granules and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, the alpha esterified starch granules have a higher number of active hydroxyl groups and higher reactivity than ordinary natural starch granules. Further, by further heating from this state, the alpha-esterified starch granules are softened as in Embodiment 1, and the hydroxyl groups are further activated to promote the reaction. Conditions such as the heating temperature at this time can be the same as those in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 6 is shown in FIG. As shown in FIG. 7, in the sixth embodiment, the polyisocyanate is present between the active hydroxyl groups of the tuft-like subunits (by chemical modification and physical modification) in starch granules or starch structures (alpha-esterified starch granules). Will be cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

Example 6
Example 6 is an example corresponding to the sixth embodiment. In Example 6, 50 parts by weight of acetic anhydride is added to 90 parts by weight of tapioca starch as the main agent and heated for 12 hours at a heating temperature of 100 ° C., thereby esterifying the hydroxyl group of tapioca starch and then washing and drying. Acetyl tapioca starch was prepared. In addition, after adding 100 parts by weight of water to 5 parts by weight of the prepared acetyl tapioca starch and mixing and stirring, the mixture was dropped on a twin drum dryer heated to 150 ° C. and rapidly gelled and thermally dried, then 250 μm. An alpha-esterified starch was prepared by grinding to a particle size of less than. In addition, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to 50 parts by weight of the alpha-esterified starch as the main ingredient, and the mixture was added. Heated at ° C. As a result, the molecules of the alpha-esterified starch were crosslinked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (1).

Embodiment 7
The solid-liquid curable plastic binder composition and the cured product thereof according to Embodiment 7 will be described. The curable plastic binder composition according to Embodiment 7 is the same as that of Embodiment 1 except that the esterified starch (chemically modified starch) of Embodiment 5 is used as the main starch. Thermally-degraded esterified starch as an activated starch further physically modified by the same method as (physically modified starch) is used. Specifically, this pyrolyzed esterified starch is obtained by activating the hydroxyl groups by thermally decomposing esterified starch obtained by esterifying the hydroxyl groups of natural starch, and thereby the total number of hydroxyl groups on the surface of the starch granules. The ratio of the number of active hydroxyl groups in is set to 1/2 or more. Of course, the pyrolyzed esterified starch used in the seventh embodiment is obtained by further activating the activated starch as in the sixth embodiment. Therefore, the pyrolyzed starch of the third embodiment and the pyrolyzed starch of the fifth embodiment are used. Compared with esterified starch, the proportion of active hydroxyl groups can be further increased, and the curing reactivity can be further improved. Thus, the esterified starch obtained by esterifying the hydroxyl group of natural starch as in Embodiment 5 is further pyrolyzed as in Embodiment 3 to mainly produce α1,4 of starch. The glycoside bond and the α1,6 glycoside bond are randomly cleaved to reduce the molecular weight of the esterified starch molecule, thereby generating pyrolyzed esterified starch having a further increased number of active hydroxyl groups on the surface of the starch granules.

The curable plastic binder composition according to Embodiment 7 is cured by mixing the pyrolyzed esterified starch as a main agent and the same polyisocyanate as in Embodiment 1 as a curing agent. For example, acetyl tapioca starch is prepared by adding a predetermined part by weight of acetic anhydride to a predetermined part by weight of tapioca starch as starch, heating at a predetermined temperature for a predetermined time, esterifying the hydroxyl group of tapioca starch, washing and drying. To do. At this time, the mixing ratio of tapioca starch to acetic anhydride is reduced by about one order (one digit) or more than in the case of the fifth embodiment. Next, acetyl tapioca starch is charged into a rotary kiln of a predetermined size heated to a predetermined temperature, and the pyrolyzed esterified starch is fed through the rotary kiln at a predetermined discharge rate at a predetermined discharge speed and thermally decomposed. Prepare. The heating temperature at this time can be the same as in the third embodiment. On the other hand, the feed rate (discharge speed) of the rotary kiln at this time is preferably in the range of 10 cm to 30 cm per minute, and particularly preferably 20 cm per minute. And with respect to the predetermined weight part of this pyrolyzed esterified starch, only the same weight part as the said pyrolyzed esterified starch is added and mixed with the mixture which mixed TDI and MDI as a polyisocyanate in the ratio of 1: 1. Then, in the same manner as in the first embodiment, the plurality of active hydroxyl groups on the surface of the pyrolyzed esterified starch granules and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, the pyrolyzed esterified starch granules have a higher number of active hydroxyl groups and higher reactivity than ordinary natural starch granules. Further, by further heating from this state, the pyrolyzed esterified starch granules are softened as in the first embodiment, and the hydroxyl groups are further activated to promote the reaction. Conditions such as the heating temperature at this time can be the same as those in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 7 is shown in FIG. As shown in FIG. 8, in the seventh embodiment, the active hydroxyl groups of the tuft-like subunits (due to chemical modification and physical modification) in the starch granules or starch structure (pyrolyzed esterified starch granules) are replaced with polyisocyanate. Will be cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

Example 7
Example 7 is an example corresponding to the seventh embodiment. In Example 7, 20 parts by weight of acetic anhydride is added to 1 part by weight of tapioca starch as the main agent and heated at a heating temperature of 100 ° C. for 12 hours, thereby esterifying the hydroxyl group of tapioca starch, and then washing and drying. Acetyl tapioca starch was prepared. Moreover, the prepared acetyl tapioca starch is put into a rotary kiln (manufactured by Kudo Engineering) having a length of 1 m and a diameter of 30 cm heated to 180 ° C., and the inside of the rotary kiln is fed at a discharge speed of 20 cm per minute, and is thermally decomposed to heat Degraded esterified starch was prepared. Further, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to 50 parts by weight of the pyrolyzed esterified starch as the main agent prepared, and mixed. Heated at 150 ° C. As a result, the molecules of the pyrolyzed esterified starch were cross-linked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (1).

Embodiment 8
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 8 will be described. The curable plastic binder composition according to Embodiment 8 is the same as that of Embodiment 1 except that the esterified starch (chemically modified starch) of Embodiment 5 is used as the starch as the main agent. Amorphous esterified starch as an activated starch that has been further physically modified in the same manner as (physically modified starch) is used. Specifically, this amorphous esterified starch is obtained by activating the hydroxyl groups by impact grinding the esterified starch obtained by esterifying the hydroxyl groups of natural starch and destroying the crystal structure. The ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface is ½ or more. Of course, since the amorphous esterified starch used in the eighth embodiment is obtained by further activating the activated starch as in the sixth and seventh embodiments, the pyrolyzed starch of the fourth embodiment and the fifth embodiment are used. Compared with the esterified starch, the ratio of active hydroxyl groups can be further increased, and the curing reactivity can be further improved. As described above, the esterified starch obtained by esterifying the hydroxyl group of natural starch as in the fifth embodiment is further converted into an amorphous starch as in the fourth embodiment, so that it is mainly adjacent to the starch particles. Hydrogen bonds between the C2-position and C3-position hydroxyl groups of α-glucose are weakened, and amorphous esterified starch in which the hydroxyl groups are further activated is generated.

The curable plastic binder composition according to the eighth embodiment is cured by mixing the amorphous esterified starch as a main agent and the same polyisocyanate as in the first embodiment as a curing agent. For example, acetyl tapioca starch is prepared by adding a predetermined part by weight of acetic anhydride to a predetermined part by weight of tapioca starch as starch, heating at a predetermined temperature for a predetermined time, esterifying the hydroxyl group of tapioca starch, washing and drying. To do. At this time, the mixing ratio of tapioca starch to acetic anhydride is reduced by about one order (one digit) or more than in the case of the fifth embodiment. Next, acetyl tapioca starch is charged into a dry ball mill, a predetermined amount of alumina balls of a predetermined diameter are charged, the dry ball mill is operated at a predetermined rotation speed for a predetermined time, and acetyl tapioca starch is impact pulverized to produce amorphous esterified starch. Prepare. Conditions such as the rotational speed and operating time of the dry ball mill and the diameter and input amount of the alumina ball can be the same as in the fourth embodiment. And with respect to the predetermined weight part of this amorphous esterified starch, only the same weight part as the said amorphous esterified starch is added and mixed with the mixture which mixed TDI and MDI as a polyisocyanate in the ratio of 1: 1. Then, in the same manner as in the first embodiment, a plurality of active hydroxyl groups on the surface of the amorphous esterified starch granules and the polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, the amorphous esterified starch granules have a higher number of active hydroxyl groups than ordinary natural starch granules, and the particles are 10 μm or less, so that the dispersibility is good and the reactivity is very high. Moreover, by further heating from this state, the amorphous esterified starch granules are softened as in Embodiment 1, and the hydroxyl groups are further activated to promote the reaction. Conditions such as the heating temperature at this time can be the same as those in the first embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 8 is shown in FIG. As shown in FIG. 9, Embodiment 8 shows a general structure (solid) of amorphous esterified starch granules (non-crystalline) that has undergone chemical and physical modification (consisting of a large number of small subunits). ) The polyisocyanate (liquid) is crosslinked between the active hydroxyl groups of the radial tuft-like units. In the figure, —OH ^* represents an active hydroxyl group.

Example 8
Example 8 is an example corresponding to the eighth embodiment. In Example 8, 20 parts by weight of acetic anhydride is added to 1 part by weight of tapioca starch as the main ingredient and heated at a heating temperature of 100 ° C. for 12 hours, thereby esterifying the hydroxyl group of tapioca starch, followed by washing and drying. Acetyl tapioca starch was prepared. In addition, the prepared acetyl tapioca starch is charged into a dry ball mill (1.2 ton made by Tokai Clay Industry) and alumina balls (diameter 10 to 100 mm) are charged in an amount ranging from 1 t to 3 t. The acetyl tapioca starch was impact-pulverized by operating at 100 rpm for 4-8 hours to prepare amorphous esterified starch. In addition, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to 50 parts by weight of the amorphous esterified starch as the main ingredient prepared, and then mixed. Heated at ° C. As a result, the molecules of the amorphous esterified starch were crosslinked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (1).

  Here, the X-ray diffraction peak of the amorphous esterified starch (amorphous acetyl tapioca starch) was measured with an X-ray diffraction peak measuring device (Rigaku Miniflex II). As a comparative example, the X-ray diffraction peak of acetyl tapioca starch was also measured with the same X-ray diffraction peak measurement apparatus. The results are shown in FIGS. Furthermore, with regard to curable bioplastic binders using amorphous acetyl tapioca starch as the main ingredient and curable bioplastic binders using esterified starch (acetyl tapioca starch) as the main ingredient, the bond vibration of urethane bonds when cured at room temperature ( The reaction rate) was measured with a Fourier transform infrared spectrometer (FT / IR-6100 manufactured by JASCO Corporation)). The result is shown in FIG. The reaction rate was determined with 100% heat cured. As shown in FIG. 12, it can be seen that the activity of the hydroxyl group is further increased and the reaction rate is further increased by the amorphization of acetyl tapioca starch.

Embodiment 9
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 9 will be described. The curable plastic binder composition according to Embodiment 9 is a one-pack type normal temperature or thermosetting bioplastic binder composition in which starch as a main agent and blocked isocyanate as a curing agent or a crosslinking agent are mixed in advance. . As the starch of the present invention, an activated starch having a ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules of 1/2 or more is used as in the first embodiment. The blocked isocyanate is stabilized by being mixed and dispersed with the starch in a state where the polyisocyanate is blocked with a predetermined blocking agent. On the other hand, when the one-component curable plastic binder composition is heated to a predetermined temperature or more, the blocking agent of the blocked isocyanate is dissociated and the isocyanate group is unblocked, and the isocyanate group of the polyisocyanate is activated. It binds to the active hydroxyl group of starch and crosslinks between intramolecular hydroxyl groups and / or intermolecular hydroxyl groups of amylose and amylopectin. Thereby, the curable plastic binder composition is cured. That is, by heating the curable plastic binder composition, the blocking agent of the blocked isocyanate is removed and the isocyanate group is activated, and a plurality of active hydroxyl groups on the surface of the starch granules are combined with the isocyanate group of the polyisocyanate (even at room temperature). ) By urethane bonding, starch molecules are cross-linked by polyisocyanate to form a three-dimensional network structure and harden. Further heating from this state further softens the starch granules and further activates the hydroxyl groups on the surface, thereby further promoting the urethane bond reaction, and the curable resin molding as the final cured product can be quickly and efficiently produced. Generate automatically. In addition, the heating temperature at this time shall be the range of 100 to 200 degreeC, for example, can be 180 degreeC or more. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 9 is shown in FIG. As shown in FIG. 13, the ninth embodiment shows a general structure (fixed) of starch granules (crystals), a radial tufted unit (consisting of a number of tufted subunits) and a blocked isocyanate (liquid). Are mixed and dispersed, and the polyisocyanate crosslinks between active hydroxyl groups of the unit by removing the blocking agent. In the figure, —OH ^* represents an active hydroxyl group.

Example 9
Example 9 is an example corresponding to the ninth embodiment. In Example 9, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 90 parts by weight of the blocked isocyanate was added as a curing agent to 50 parts by weight of tapioca starch as the main agent, and mixed to prepare a one-component curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of tapioca starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. The reaction formula at this time is represented by the following formula (2).
BL-OCHN-R-NHCO-BL ⇔ 2 BL + OCN-R-NCO
2 St-OH + OCN-R-NCO → St-O-OCHN-R-NHCO-O-St (2)
In the formula, “BL” represents a blocking agent. Here, examples of the blocking agent (BL) include ketoxime blocking agents such as ε-caprolactam, methyl ethyl ketoxime, methyl isoamyl ketoxime, methyl isobutyl ketoxime, oxime blocking agents, phenol, cresol, catechol, nitrophenol and the like. Phenol-based blocking agents, alcohol-based blocking agents such as isopropanol and trimethylolpropane, active methylene-based blocking agents such as malonic acid esters and acetoacetic acid esters, and the like can be suitably used. In particular, when an oxime blocking agent is used as the blocking agent, uniform dispersion of starch in the blocked isocyanate (liquid) can be performed very smoothly. On the other hand, when an alcohol-based blocking agent is used, an ethanol-based one is not so preferable from the viewpoint of uniform dispersibility of starch, and a methanol-based one is preferably used as described above.

Embodiment 10
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 10 will be described. In the ninth embodiment, the curable plastic binder composition according to the tenth embodiment uses the same alpha starch as the second embodiment as the main starch. That is, in the tenth embodiment, as the starch, natural starch is hydrolyzed and gelled by heating, then rapidly heat-dried and alphalated to activate the hydroxyl groups, and the number of active hydroxyl groups in the total number of hydroxyl groups on the starch granule surface. Alpha starch having a ratio of ½ or more is used, and this alpha starch is mixed with the blocked isocyanate to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the alpha starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 10 is shown in FIG. As shown in FIG. 14, in Embodiment 10, the small subunits (by physical modification) and blocked isocyanate in starch granules or starch structures (alpha starch granules) are mixed and dispersed, and the blocking agent is removed. Thus, the polyisocyanate crosslinks between the active hydroxyl groups of the subunits. In the figure, —OH ^* represents an active hydroxyl group.

Example 10
Example 10 is an example corresponding to the tenth embodiment. In Example 10, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 100 parts by weight of water was added to 90 parts by weight of corn starch, and the mixture was stirred and dropped onto a twin drum dryer (manufactured by Central Foods) heated to 150 ° C. to quickly gel and heat dry. Thereafter, the starch was ground to a particle size of less than 250 μm to prepare an alpha starch. Further, 90 parts by weight of the blocked isocyanate as a curing agent was mixed with 50 parts by weight of the prepared alpha starch as a main agent to prepare a one-component curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of the alpha starch were crosslinked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 11
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 11 will be described. The curable plastic binder composition according to Embodiment 11 uses the same pyrolytic starch as in Embodiment 3 as the starch as the main agent in Embodiment 9. That is, in the eleventh embodiment, as the starch, pyrolyzed starch in which natural starch is pyrolyzed to activate the hydroxyl groups so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 1/2 or more. This pyrolyzed starch is mixed with the blocked isocyanate to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. Unblock the group and activate the polyisocyanate to crosslink the starch molecules of the pyrolyzed starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 11 is shown in FIG. As shown in FIG. 15, in the eleventh embodiment, the small subunits (by physical modification) and the blocked isocyanate in the starch granules or starch structure (pyrolyzed starch granules) are mixed and dispersed, and the blocking agent is removed. As a result, the polyisocyanate crosslinks between the active hydroxyl groups of the subunits. In the figure, —OH ^* represents an active hydroxyl group.

Example 11
Example 11 is an example corresponding to the eleventh embodiment. In Example 11, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, the corn starch is charged into a rotary kiln (made by KS Material) having a length of 1.8 m and a diameter of 0.2 m heated to 180 ° C., and the rotational speed of 1 to 20 rpm and the discharge speed per minute in the rotary kiln. Pyrolysis starch was prepared by feeding at a speed of 30 cm and pyrolysis. Further, 90 parts by weight of the blocked isocyanate as a curing agent was mixed with 50 parts by weight of the prepared alpha starch as a main agent to prepare a one-component curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of the pyrolysis starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 12
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 12 will be described. The curable plastic binder composition according to the twelfth embodiment uses the same amorphous starch as in the fourth embodiment as the main starch in the ninth embodiment. That is, in Embodiment 12, as the starch, natural starch is impact pulverized to destroy the crystal structure to activate the hydroxyl groups, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 1/2 or more. Amorphous starch is used, and this amorphous starch is mixed with the blocked isocyanate to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. Unblock the group and activate the polyisocyanate to crosslink the starch molecules of the amorphous starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 12 is shown in FIG. As shown in FIG. 16, the twelfth embodiment shows a general structure (fixed) of physically modified amorphous starch granules (non-crystalline) (radial tuft-like unit composed of a large number of tuft-like subunits). And blocked isocyanate (liquid) are mixed and dispersed, and the blocking agent is removed, so that the polyisocyanate crosslinks between the active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 12
Example 12 is an example corresponding to the twelfth embodiment. In Example 12, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, the corn starch was put into a dry ball mill (1.2 ton made by Tokai clay industry) and operated for 6 hours, and the corn starch was impact pulverized to prepare amorphous starch. In addition, 50 parts by weight of the prepared amorphous starch was mixed with 90 parts by weight of the blocked isocyanate as a curing agent to prepare a one-component curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of amorphous starch were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 13
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 13 will be described. The curable plastic binder composition according to Embodiment 13 uses the same esterified starch as that of Embodiment 5 as starch as the main agent in Embodiment 9. That is, in Embodiment 13, as starch, esterification is performed by esterifying the hydroxyl groups of natural starch to activate the hydroxyl groups so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is 40% or more. Starch is used, and this esterified starch is mixed with the blocked isocyanate to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. Unblock the group and activate the polyisocyanate to crosslink the starch molecules of the esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 13 is shown in FIG. As shown in FIG. 17, the thirteenth embodiment shows a general structure (fixed) of chemically modified esterified starch granules (crystals), which is a radial tuft-shaped unit (consisting of a large number of tuft-shaped subunits). And blocked isocyanate (liquid) are mixed and dispersed, and the blocking agent is removed, so that the polyisocyanate crosslinks between the active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 13
Example 13 is an example corresponding to the thirteenth embodiment. In Example 13, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 50 parts by weight of acetic anhydride is added to 10 parts by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. In addition, 50 parts by weight of the prepared acetyl tapioca starch was mixed with 90 parts by weight of the blocked isocyanate as a curing agent to prepare a one-part curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of esterified starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 14
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 14 will be described. The curable plastic binder composition according to Embodiment 14 is obtained by using the same alpha-esterified starch as in Embodiment 6 as starch as the main agent in Embodiment 9. That is, in Embodiment 14, as an starch, an esterified starch obtained by esterifying the hydroxyl group of natural starch is hydrolyzed and gelled, and then rapidly heat-dried and alphalated to activate the alpha ester. This alpha-esterified starch is mixed with the blocked isocyanate to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the alpha esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 14 is shown in FIG. As shown in FIG. 18, in the fourteenth embodiment, small subunits (by chemical modification and physical modification) and blocked isocyanate in starch granules or starch structures (alpha-esterified starch granules) are mixed and dispersed. By removing the blocking agent, the polyisocyanate crosslinks between the active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 14
Example 14 is an example corresponding to the fourteenth embodiment. In Example 14, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and A part by weight was prepared. Next, 50 parts by weight of acetic anhydride is added to 10 parts by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. Further, 100 parts by weight of water added to 5 parts by weight of the prepared acetyl tapioca starch and mixed and stirred are dropped on a twin drum dryer (manufactured by Central Foods) heated to 150 ° C. to quickly gel and heat. After drying, it was pulverized to a particle size of less than 250 μm to prepare an alpha-esterified starch. Further, 90 parts by weight of the blocked isocyanate as a curing agent was mixed with 50 parts by weight of the prepared alpha-esterified starch as a main agent to prepare a one-component curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of the alpha-esterified starch were crosslinked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 15
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 15 will be described. The curable plastic binder composition according to the fifteenth embodiment uses the same pyrolyzed esterified starch as in the seventh embodiment as the main starch in the ninth embodiment. That is, in the fifteenth embodiment, as the starch, pyrolyzed esterified starch in which the hydroxyl group is activated by thermally decomposing esterified starch obtained by esterifying the hydroxyl group of natural starch is used. Is mixed with the blocked isocyanate to form a one-component type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the pyrolyzed esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 15 is shown in FIG. As shown in FIG. 19, in the fifteenth embodiment, small subunits (by chemical modification and physical modification) and blocked isocyanate (liquid) in starch granules or starch structures (pyrolyzed esterified starch granules) are contained. By mixing and dispersing and releasing the blocking agent, the polyisocyanate crosslinks between active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 15
Example 15 is an example corresponding to the fifteenth embodiment. In Example 15, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 50 parts by weight of acetic anhydride is added to 10 parts by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. Moreover, the prepared acetyl tapioca starch is put into a rotary kiln (manufactured by Kudo Engineering) having a length of 1 m and a diameter of 30 cm heated to 180 ° C., and the inside of the rotary kiln is fed at a discharge speed of 20 cm per minute, and is thermally decomposed to heat Degraded esterified starch was prepared. In addition, 50 parts by weight of the pyrolyzed esterified starch as the main agent thus prepared was mixed with 90 parts by weight of the blocked isocyanate as a curing agent to prepare a one-part curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of the pyrolyzed esterified starch were cross-linked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 16
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 16 will be described. The curable plastic binder composition according to Embodiment 16 uses the same amorphous esterified starch as in Embodiment 8 as the starch as the main agent in Embodiment 9. That is, in Embodiment 16, as the starch, the esterified starch obtained by esterifying the hydroxyl group of natural starch is impact pulverized to destroy the crystal structure, thereby activating the hydroxyl group and activating the hydroxyl group. Starch is used, and this amorphous esterified starch is mixed with the blocked isocyanate to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the ninth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the ninth embodiment. Unblock the group and activate the polyisocyanate to crosslink the starch molecules of the amorphous esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 16 is shown in FIG. As shown in FIG. 20, in the sixteenth embodiment, radial tufted units and blocks (consisting of a number of tufted subunits) showing the general structure (fixed) of amorphous esterified starch granules (non-crystalline) The isocyanate (liquid) is mixed and dispersed, and the blocking agent is removed, so that the polyisocyanate crosslinks between the active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 16
Example 16 is an example corresponding to the sixteenth embodiment. In Example 16, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 50 parts by weight of acetic anhydride is added to 10 parts by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. In addition, the prepared acetyl tapioca starch is charged into a dry ball mill (1.2 ton made by Tokai Clay Industry) and alumina balls (diameter 10 to 100 mm) are charged in an amount ranging from 1 t to 3 t. The acetyl tapioca starch was impact-pulverized by operating at 100 rpm for 4-8 hours to prepare amorphous esterified starch. Further, 90 parts by weight of the blocked isocyanate as a curing agent was mixed with 50 parts by weight of the amorphous esterified starch as the main agent thus prepared to prepare a one-pack type curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of the amorphous esterified starch were crosslinked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (2).

Embodiment 17
The one-pack type aqueous curable plastic binder composition and the cured product thereof according to Embodiment 17 will be described. The curable plastic binder composition according to Embodiment 17 is a premixed mixture of colloidal starch in which starch as a main agent is colloidal (sol or gel) and blocked isocyanate as a curing agent or a crosslinking agent. It is a liquid normal temperature or thermosetting bioplastic binder composition. Colloidal starch is a sol or gelled (sol-like or gel-like) colloidal form obtained by hydrothermally heating starch as a main agent in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is 1/2 or more. It is what makes. Further, the blocked isocyanate is the same as that in the above-mentioned embodiment 9, and is mixed and dispersed with the colloidal starch in a state where the polyisocyanate is blocked with a predetermined blocking agent (in a normal micelle shape or reverse micelle shape). Emulsified and stabilized. That is, in Embodiment 17, colloidal starch and normal micelles (sol-form or gel-form) colloidal starch (usually hydrophobic) without adding or mixing an emulsifier or dispersant such as a surfactant. The block isocyanate is dispersed in the colloidal starch stably and uniformly in the form of particles, or the blocked isocyanate forms a reverse micelle emulsion with the colloidal starch, and the colloidal starch is blocked. The particles are stably dispersed uniformly in the form of particles in the isocyanate. This is thought to be due to the hydrogen bonding of the hydroxyl groups of the starch molecules due to the sol-formation or gelation of the starch. On the other hand, in such a one-pack type curable plastic binder composition, when heated to a predetermined temperature or higher, the water content of the colloidal starch is first evaporated, and the hydrogen bonds in the starch sol or starch gel are released. The blocking agent of the blocked isocyanate is dissociated to unblock the isocyanate group, the isocyanate group of the polyisocyanate is activated and bonded to the active hydroxyl group of the starch, and the intramolecular hydroxyl group and / or intermolecular hydroxyl group of amylose and amylopectin Cross-links between them. Thereby, the curable plastic binder composition is cured. That is, by heating the curable plastic binder composition, the blocking agent of the blocked isocyanate is removed and the isocyanate group is activated, and a plurality of active hydroxyl groups on the surface of the starch granules are combined with the isocyanate group of the polyisocyanate (even at room temperature). ) By urethane bonding, starch molecules are cross-linked by polyisocyanate to form a three-dimensional network structure and harden. Further heating from this state further softens the starch granules and further activates the hydroxyl groups on the surface, thereby further promoting the urethane bond reaction, and the curable resin molding as the final cured product can be quickly and efficiently produced. Generate automatically. In addition, the heating temperature at this time shall be the range of 100 to 200 degreeC, for example, can be 180 degreeC or more. Here, it is particularly preferable to use an oxime-based blocking agent as the blocking agent. In this case, emulsification of blocked isocyanate and colloidal starch can be carried out very smoothly and stably. On the other hand, when using an alcohol-based blocking agent, an ethanol-based one is not so preferable from the viewpoint of stably emulsifying a blocked isocyanate and colloidal starch, and a methanol-based one should be used as described above. Is preferred. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 17 is shown in FIG. As shown in FIG. 21, in the seventeenth embodiment, radial tufted units (consisting of a number of tufted subunits) showing a general structure of sol or gelled starch granules (crystals) and blocked isocyanate By mixing and dispersing and releasing the blocking agent, the polyisocyanate crosslinks between active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 17
Example 17 is an example corresponding to the seventeenth embodiment. In Example 17, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 300 to 500 parts by weight of water was added to 50 parts by weight of tapioca starch as the main agent, and the mixture was heated to 80 ° C. to gel to prepare colloidal starch. Then, 90 parts by weight of the blocked isocyanate is added to the colloidal starch as a curing agent, mixed, and stirred at high speed, whereby a one-component curable plastic binder composition in which a forward micelle structure emulsion is stably produced. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of tapioca starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of tapioca starch as a main ingredient is added to 120 parts by weight of this blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to this mixture, and the mixture is stirred at a low speed to give reverse micelles. A one-part curable plastic binder composition in which an emulsion having a structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of tapioca starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly.

In either case, the reaction formula is represented by the following formula (3).
St-OH ---- H ₂ O → St-OH + H ₂ O ↑
BL-OCHN-R-NHCO-BL ⇔ 2 BL + OCN-R-NCO
2 St-OH + OCN-R-NCO → St-O-OCHN-R-NHCO-O-St (3)

Embodiment 18
A one-component water-based curable plastic binder composition and a cured product thereof according to Embodiment 18 will be described. The curable plastic binder composition according to Embodiment 18 uses the same alpha starch as in Embodiment 2 as the starch as the main agent in Embodiment 17. That is, in the eighteenth embodiment, as the starch, natural starch is hydrolyzed and gelled by heating, and then rapidly heat-dried and alphalated to activate the hydroxyl groups, and the number of active hydroxyl groups in the total number of hydroxyl groups on the surface of the starch granules. Alpha starch having a ratio of ½ or more is used, and this alpha starch is made into a sol or gel to prepare a colloidal starch, which is mixed with the blocked isocyanate and emulsified to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the alpha starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 18 is shown in FIG. As shown in FIG. 22, in the eighteenth embodiment, small subunits (due to physical modification) showing sol or gelled alpha starch granules or starch structures and block isocyanate (liquid) are mixed and dispersed to form a block. The polyisocyanate crosslinks between the active hydroxyl groups of the unit by removing the agent. In the figure, —OH ^* represents an active hydroxyl group.

Example 18
Example 18 is an example corresponding to the eighteenth embodiment. In Example 18, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and A part by weight was prepared. Next, 100 parts by weight of water was added to 5 parts by weight of corn starch, and the mixture was stirred and dripped onto a twin drum dryer (made by Central Foods) heated to 150 ° C., and rapidly gelled and thermally dried. Then, it grind | pulverized so that it might become a particle size of less than 250 micrometers, and the corn alpha starch was prepared. Moreover, 300-500 weight part of water was added with respect to 50 weight part of corn alpha starch as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of corn alpha starch were cross-linked with polyisocyanate to form a urethane bond, and curing proceeded rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of corn alpha starch as a main ingredient is added to 120 parts by weight of this blocked isocyanate and stirred. Further, 1 to 500 parts by weight of water is added to this mixture, and the mixture is stirred at a low speed. A one-part curable plastic binder composition in which a micelle emulsion was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of corn alpha starch were cross-linked with polyisocyanate to form a urethane bond, and curing proceeded rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

Embodiment 19
A one-component water-based curable plastic binder composition and a cured product thereof according to Embodiment 19 will be described. The curable plastic binder composition according to Embodiment 19 uses the same pyrolytic starch as in Embodiment 3 as the starch as the main agent in Embodiment 17. That is, in the nineteenth embodiment, as the starch, pyrolyzed starch in which natural starch is thermally decomposed to activate the hydroxyl groups so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is 1/2 or more. The pyrolyzed starch is used in the form of a sol or gel to prepare a colloidal starch, which is mixed with the blocked isocyanate and emulsified to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the pyrolyzed starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 19 is shown in FIG. As shown in FIG. 23, in the nineteenth embodiment, small subunits (by physical modification) showing a sol or gelled pyrolyzed starch granule or starch structure and block isocyanate (liquid) are mixed and dispersed. When the blocking agent is removed, the polyisocyanate crosslinks between the active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 19
Example 19 is an example corresponding to the nineteenth embodiment. In Example 19, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and A part by weight was prepared. Next, corn starch is charged into a rotary kiln (made by KS Material) having a length of 1.8 m and a diameter of 0.2 m heated to 180 ° C., and the rotational speed of the rotary kiln is 1 to 20 rpm and the discharge speed is 30 cm per minute. And then pyrolyzed to prepare pyrolyzed starch. Moreover, 300-500 weight part of water was added with respect to 50 weight part of pyrolysis starch (corn dextrin) as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of corn dextrin were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of corn dextrin as a main ingredient is added to 120 parts by weight of this blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to this mixture and stirred at a low speed, thereby reverse micelles. A one-part curable plastic binder composition in which an emulsion having a structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of corn dextrin were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

Embodiment 20
The one-pack type aqueous curable plastic binder composition and the cured product thereof according to Embodiment 20 will be described. The curable plastic binder composition according to Embodiment 20 uses the same amorphous starch as in Embodiment 4 as the starch as the main agent in Embodiment 17. That is, in the twentieth embodiment, as starch, natural starch is impact-pulverized to destroy the crystal structure to activate the hydroxyl groups, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 1/2 or more. Amorphous starch is used, and the amorphous starch is made into a sol or gel to prepare a colloidal starch, which is mixed with the blocked isocyanate and emulsified to form a one-pack type. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. Unblock the group and activate the polyisocyanate to crosslink the starch molecules of the amorphous starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 20 is shown in FIG. As shown in FIG. 24, in the twentieth embodiment, a radial tufted unit (consisting of a large number of tufted subunits) showing a general structure of amorphous starch granules (non-crystalline), and a blocked isocyanate (liquid) Are mixed and dispersed, and the polyisocyanate crosslinks between the active hydroxyl groups of the unit by removing the blocking agent. In the figure, —OH ^* represents an active hydroxyl group.

Example 20
Example 20 is an example corresponding to the twentieth embodiment. In Example 20, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed in a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and A part by weight was prepared. Next, corn starch is charged into a dry ball mill (1.2 ton made by Tokai clay industry) and alumina balls (diameter 10 to 100 mm) are charged in an amount ranging from 1 to 3 t, and the dry ball mill is rotated at 30 to 100 rpm. The corn starch was pulverized by impact pulverization for 4 to 8 hours to prepare amorphous starch. Moreover, 300-500 weight part of water was added with respect to 50 weight part of amorphous starch as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of corn dextrin were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. FIG. 25 shows a dispersion example of a forward micelle emulsion prepared under the conditions described in the twentieth embodiment. As a comparative example, FIG. 26 shows a dispersion example of a forward micelle structure emulsion prepared under conditions different from those described in Embodiment 20. Both FIG. 25 and FIG. 26 are optical micrographs at a predetermined magnification (× 100). As shown in FIG. 25, in the forward micelle structure emulsion prepared under the conditions described in Embodiment 20, the sol-like or gel-like amorphous starch (colloidal starch) and the blocked isocyanate are well dispersed. As shown in FIG. 26, in a forward micelle structure emulsion prepared under conditions different from those described in Embodiment 20, sol-like or gel-like amorphous starch (colloidal starch) and blocked isocyanate are sufficiently dispersed. It can be confirmed that the dispersion is poor.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of amorphous starch as a main ingredient is added to 120 parts by weight of the blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to the mixture, and the mixture is stirred at a low speed, thereby reverse micelles. A one-part curable plastic binder composition in which an emulsion having a structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of amorphous starch were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

Embodiment 21
The one-pack type aqueous curable plastic binder composition and the cured product thereof according to Embodiment 21 will be described. The curable plastic binder composition according to Embodiment 21 is obtained by using the same esterified starch as in Embodiment 5 as starch as the main agent in Embodiment 17. That is, in Embodiment 21, as starch, esterification of the hydroxyl group of natural starch is performed by esterification, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is 40% or more. Using starch, the esterified starch is made into a sol or gel to prepare a colloidal starch, and mixed with the blocked isocyanate to be emulsified into a one-pack type. In addition, the preparation of the esterified starch in Embodiment 21 can be performed in the same manner as the preparation of the esterified starch in Embodiments 6 to 9, and the blending ratio of starch such as tapioca starch to acetic anhydride and the like is as follows. The order is reduced by one order (one digit) or more than in the fifth embodiment. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. Unblock the group and activate the polyisocyanate to crosslink the starch molecules of the esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 21 is shown in FIG. As shown in FIG. 27, Embodiment 21 shows a general structure of sol-gelled or gelled esterified starch granules (crystals) (radial tuft-like units composed of a large number of tuft-like subunits) The blocked isocyanate (liquid) is mixed and dispersed, and the polyisocyanate crosslinks between the active hydroxyl groups of the unit by removing the blocking agent. In the figure, —OH ^* represents an active hydroxyl group.

Example 21
Example 21 is an example corresponding to the twenty-first embodiment. In Example 21, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 20 parts by weight of acetic anhydride is added to 1 part by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. Moreover, 300-500 weight part of water was added with respect to 50 weight part of acetyl tapioca starch as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of acetyl tapioca starch was bridge | crosslinked by polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of acetyl tapioca starch as a main ingredient is added to 120 parts by weight of this blocked isocyanate and stirred. Further, 1 to 500 parts by weight of water is added to this mixture, and the mixture is stirred at a low speed. A one-part curable plastic binder composition in which a micelle emulsion was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of acetyl tapioca starch was bridge | crosslinked by polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

Embodiment 22
A one-component aqueous curable plastic binder composition and a cured product thereof according to Embodiment 22 will be described. The curable plastic binder composition according to Embodiment 22 uses the same alpha-esterified starch as in Embodiment 6 as the starch as the main agent in Embodiment 17. That is, in Embodiment 22, as an starch, an esterified starch obtained by esterifying a hydroxyl group of natural starch is heated and gelled, and then rapidly heat-dried and alphalated to activate the hydroxyl ester. Using a modified starch, this alpha-esterified starch is made into a sol or gel to prepare a colloidal starch, which is mixed with the blocked isocyanate and emulsified to form a one-pack type. The esterified starch in Embodiment 22 can be prepared in the same manner as in the preparation of the esterified starch in Embodiment 21, and the ratio of starch such as tapioca starch to acetic anhydride etc. The number is reduced by one order (one digit) or more than in the case of Form 6. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the alpha esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 22 is shown in FIG. As shown in FIG. 28, in Embodiment 22, the tufted subunits showing the sol-gelled or gelled alpha-esterified starch granules and the blocked isocyanate (liquid) are mixed and dispersed, and the blocking agent is removed. Polyisocyanate crosslinks between active hydroxyl groups in the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 22
Example 22 is an example corresponding to the twenty-second embodiment. In Example 22, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 20 parts by weight of acetic anhydride is added to 1 part by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. Further, 100 parts by weight of water added to 5 parts by weight of the prepared acetyl tapioca starch and mixed and stirred are dropped on a twin drum dryer (manufactured by Central Foods) heated to 150 ° C. to quickly gel and heat. After drying, the mixture was pulverized to a particle size of less than 250 μm to prepare an alpha esterified starch (acetyl tapioca alpha starch). Moreover, 300-500 weight part of water was added with respect to 50 weight part of acetyl tapioca alpha starch as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of acetyl tapioca alpha starch were cross-linked with polyisocyanate to form a urethane bond, and curing proceeded rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of acetyl tapioca alpha starch as a main ingredient is added to 120 parts by weight of this blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to this mixture and stirred at a low speed. A one-part curable plastic binder composition in which an emulsion having a reverse micelle structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of acetyl tapioca alpha starch were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

Embodiment 23
A one-component aqueous curable plastic binder composition and a cured product thereof according to Embodiment 23 will be described. The curable plastic binder composition according to Embodiment 23 uses the same pyrolyzed esterified starch as in Embodiment 7 as the main ingredient starch in Embodiment 17. That is, in Embodiment 23, as the starch, pyrolyzed esterified starch in which the hydroxyl group is activated by thermally decomposing esterified starch obtained by esterifying the hydroxyl group of natural starch is used, and this pyrolyzed esterified starch is used. Colloidal starch is prepared by solating or gelling, and is mixed with the blocked isocyanate to be emulsified to form a one-pack type. The preparation of the esterified starch in Embodiment 23 can be performed in the same manner as the preparation of the esterified starch in Embodiment 21 above, and the mixing ratio of starch such as tapioca starch to acetic anhydride etc. The order is reduced by one order (one digit) or more than in the case of Form 7. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the pyrolyzed esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 23 is shown in FIG. As shown in FIG. 29, in Embodiment 23, small subunits showing the general structure of pyrolyzed esterified starch granules that have been solated or gelled and blocked isocyanate (liquid) are mixed and dispersed to form a blocking agent. The polyisocyanate crosslinks between the active hydroxyl groups of the unit. In the figure, —OH ^* represents an active hydroxyl group.

Example 23
Example 23 is an example corresponding to the twenty-third embodiment. In Example 23, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and A part by weight was prepared. Next, 20 parts by weight of acetic anhydride is added to 1 part by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. Moreover, the prepared acetyl tapioca starch is charged into a rotary kiln (made by KS Material) having a length of 1 m and a diameter of 0.2 m heated to 180 ° C., and the rotary kiln is rotated at a rotation speed of 1 to 20 rpm and a discharge speed per minute. Pyrolysis esterified starch (acetulapiocadextrin) was prepared by feeding at a speed of 30 cm and pyrolyzing. Moreover, 300-500 weight part of water was added with respect to 50 weight part of acetyl tapioca dextrin as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of acetyl tapioca dextrin were cross-linked with polyisocyanate to form a urethane bond, and curing proceeded rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of acetyl tapioca dextrin as the main agent is added to 120 parts by weight of this blocked isocyanate and stirred. Further, 1 to 500 parts by weight of water is added to this mixture and the mixture is stirred at a low speed. A one-part curable plastic binder composition in which a micelle emulsion was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of acetyl tapioca dextrin were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

Embodiment 24
The one-component water-based curable plastic binder composition and the cured product thereof according to Embodiment 24 will be described. The curable plastic binder composition according to Embodiment 24 uses the same amorphous esterified starch as in Embodiment 8 as the starch as the main agent in Embodiment 17. That is, in Embodiment 24, as the starch, the esterified starch obtained by esterifying the hydroxyl group of natural starch is impact-pulverized to destroy the crystal structure, thereby activating the hydroxyl group and activating the hydroxyl group. A starch is used, and this amorphous esterified starch is made into a sol or gel to prepare a colloidal starch, which is mixed with the blocked isocyanate and emulsified to form a one-pack type. The preparation of the esterified starch in the embodiment 24 can be performed in the same manner as the preparation of the esterified starch in the embodiment 21, and the mixing ratio of the starch such as tapioca starch to the acetic anhydride or the like is Compared to the case of Form 8, it is reduced by one order (one digit) or more. Such a one-component curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the seventeenth embodiment, whereby the blocking agent of the blocked isocyanate is dissociated as in the seventeenth embodiment. The group is unblocked and the polyisocyanate is activated to crosslink the starch molecules of the amorphous esterified starch. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 24 is shown in FIG. As shown in FIG. 30, in Embodiment 24, small subunits showing the general structure of sol-form or gelled amorphous esterified starch granules and blocked isocyanate (liquid) are mixed and dispersed, and the blocking agent is used. The polyisocyanate crosslinks between the active hydroxyl groups of the unit by coming off. In the figure, —OH ^* represents an active hydroxyl group.

Example 24
Example 24 is an example corresponding to the twenty-fourth embodiment. In Example 24, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 20 parts by weight of acetic anhydride is added to 1 part by weight of tapioca starch and heated at a heating temperature of 100 ° C. for 12 hours to esterify the hydroxyl group of tapioca starch, and then washed and dried to obtain acetyl tapioca starch. Was prepared. In addition, the prepared acetyl tapioca starch is introduced into a dry ball mill (1.2 ton made by Tokai Clay Industry) and alumina balls (diameter 10 to 100 mm) are introduced in an amount ranging from 1 t to 3 t. It was operated at a rotation speed of 100 rpm for 4 to 8 hours, and acetyl tapioca starch was impact pulverized to prepare amorphous acetyl tapioca starch. Moreover, 300-500 weight part of water was added with respect to 50 weight part of amorphous acetyl tapioca starch as a main ingredient prepared, and it heated and gelatinized at 80 degreeC, and prepared the colloidal starch. Then, the one-part curable plastic binder composition in which the emulsion of a normal micelle structure is stably produced by mixing the colloidal starch with 90 parts by weight of the blocked isocyanate as a curing agent and stirring at high speed. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of amorphous acetyl tapioca starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of amorphous acetyl tapioca starch as a main ingredient is added to 120 parts by weight of this blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to this mixture and stirred at a low speed. A one-part curable plastic binder composition in which an emulsion having a reverse micelle structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecule | numerator of amorphous acetyl tapioca starch was bridge | crosslinked by the polyisocyanate, the urethane bond was carried out, and hardening advanced rapidly. In any of the above cases, the reaction formula is represented by the above formula (3).

  By the way, in Examples 17-24 corresponding to the above-described Embodiments 17-24, various starches as the main agent are prepared in a gel form, but this becomes a gel form over time through a sol-like stage. This means that if the gelled starch is stirred, it becomes sol again.

  Moreover, in the said Embodiment 17-23, it is preferable to prepare sol-form or gel-form starch (colloidal starch) so that PH may be set to the range of 5-9. In this way, the starch gel or starch sol (colloidal starch) can be further stabilized.

  Further, when sol- or gel-like starch (colloidal starch) is used as a main agent as in the above-described Embodiments 17 to 23, an oxime-based blocking agent such as a ketoxime-based blocking agent is used as the blocked isocyanate blocking agent It is preferable to use it. In this way, the emulsification of the blocked isocyanate (liquid) and the colloidal starch can be performed more smoothly and stable and uniform dispersion can be achieved.

Embodiment 25
A curable plastic binder composition and a cured product thereof according to Embodiment 25 will be described. The curable plastic binder composition according to Embodiment 25 is a solid (starch) + liquid (polyisocyanate) type, ie, a solid-liquid type, composed of cellulose as a main agent and polyisocyanate as a curing agent or a crosslinking agent. It is a room temperature or thermosetting bioplastic binder composition. As the cellulose of the present invention, activated cellulose is used in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is increased from that of non-activated cellulose such as natural cellulose. That is, non-activated cellulose such as natural cellulose has three hydroxyl groups for each amylose unit of each cellulose molecule, but only one of them is an active hydroxyl group, and the remaining two are (hydrogen bonds and steric hindrances). It is an inactive hydroxyl group that has lost its activity due to, for example. Therefore, in the non-activated cellulose such as natural cellulose, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is about 1/3 as usual. On the other hand, the present invention activates non-activated cellulose as a cellulose as a main agent by physical modification, chemical modification, or a combination of chemical modification and physical modification, thereby increasing the activity in the total number of hydroxyl groups on the cellulose surface. A cellulose (referred to as “activated cellulose” in the present application document) in which the ratio of the number of hydroxyl groups is increased from the case of non-activated cellulose (1/3) is used. Specifically, the present invention uses activated cellulose in which the ratio of the active hydroxyl group in the activated cellulose is ½ or more as the main agent. In addition, as long as the activated cellulose of the present invention is used, any cellulose such as natural cellulose, a cellulose derivative obtained by chemically modifying natural cellulose, or a cellulose derivative obtained by further physical modification can be used. Moreover, at present, cellulose is only natural starch that exists in nature, but if synthetic cellulose (not modified cellulose) having an equivalent composition by chemical synthesis can be produced, such synthetic cellulose can also be used as cellulose. . Here, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is difficult to measure accurately, but as in the case of the above starch, cellulose as a main agent and polyisocyanate as a curing agent are mixed. The ratio of active hydroxyl groups can be estimated by comparing the reaction rates when reacted.

Hereinafter, cellulose as the main agent used in the present invention will be described. Cellulose is a polymer (polysaccharide) in which D-glucose residues are linearly linked by β-1,4 glycosidic bonds, and is a chain polymer having a cellobiose unit as one unit. Natural cellulose is abundant in plant cell walls, and the degree of polymerization and average molecular weight vary depending on the plant species, but cotton and hemp have a degree of polymerization of about 2,000 to 3,000 and an average molecular weight of about 300,000 to 500,000. The general structural formula (partial formula) of the cellulose molecule is shown below.

  The glucose unit (glucose residue) of cellulose has a hydroxy group (hydroxyl group) at the C (2) position, C (3) position and C (6) position, and the hydroxyl groups at the 2nd and 3rd positions are secondary hydroxyl groups, The hydroxyl group at the 6-position is a primary hydroxyl group. In addition, the hydroxyl group at the C (1) position at one end of the cellulose molecule is a reducing end group exhibiting reducibility, and the hydroxyl group at the C (4) position at the other end is a non-reducing end group that does not exhibit reducibility. It is. While the hydroxyl group of the glucose residue in cellulose has an equator bond, while the carbon atom and the hydrogen atom are axially bonded, the cellulose molecular chain has hydrophobic and hydrophilic sites. Cellulose molecules form not only intramolecular hydrogen bonds but also intermolecular hydrogen bonds between hydroxyl groups. Therefore, the cellulose molecule is a rigid plate-like molecule in which hydrogen bonds in the molecule are formed between O3-05, and forms a layered structure in which adjacent cellulose molecules are further bonded by intermolecular hydrogen bonds due to hydroxyl groups. . For this reason, cellulose is almost insoluble in water. Thus, since the functionality of the hydroxyl group (active hydroxyl group) which has activity is inhibited in the cellulose, the isocyanate group (N = C = The number of active hydroxyl groups that react with O) is not sufficient, particularly in terms of reactivity or curability at room temperature or the like.

  Therefore, the present inventors have released the hydrogen bond between the molecules of normal natural cellulose by physical modification or chemical modification, so that the ratio of the number of active hydroxyl groups on the cellulose surface is 1/2 or more of the total number of hydroxyl groups. It has been improved to become. That is, the cellulose of the embodiment 25 and the following embodiments 26 to 30 is a cellulose prepared so that the number of active hydroxyl groups on the cellulose surface becomes a ratio of 1/2 or more of the total number of hydroxyl groups on the cellulose surface. Here, in Embodiment 25, it is preferable to use activated cellulose prepared by chemical modification or the like so that the number of active hydroxyl groups on the cellulose surface is at least a half of the total number of hydroxyl groups on the cellulose surface. It is also possible to selectively use natural cellulose in which the number of active hydroxyl groups on the cellulose surface is a ratio of 1/2 or more of the total number of hydroxyl groups on the cellulose surface.

  As the polyisocyanate that reacts with the hydroxyl group of the cellulose to crosslink the cellulose molecule, the polyisocyanate (TDI, MDI, etc.) described in the first embodiment can be used.

The curable plastic binder composition according to Embodiment 25 configured as described above is cured by mixing the activated cellulose as a main component and polyisocyanate as a curing agent. For example, a mixture obtained by mixing TDI and MDI as a polyisocyanate at a ratio of 1: 1 with respect to a predetermined part by weight of wood flour as cellulose is added in the same weight part as the cellulose and mixed. Then, a plurality of active hydroxyl groups (OH) on the cellulose surface is urethane-bonded (NHCOO) with the isocyanate group (NCO) of the polyisocyanate at room temperature, whereby the cellulose molecules or the cellulose microfibrils (MF) are cross-linked by the polyisocyanate, A three-dimensional network structure is formed and cured. When further heated from this state, the hydroxyl group on the cellulose surface is further activated, whereby the urethane bond reaction is further promoted, and a curable resin molded product as a final cured product is quickly and efficiently produced. In addition, the heating temperature at this time shall be the range of 100 degreeC or more and 200 degreeC, for example, can be 150 degreeC. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 25 is shown in FIG. As shown in FIG. 31, in Embodiment 25, a polyisocyanate (liquid) is crosslinked between active hydroxyl groups of a general structure (fiber) of cellulose (crystal). In the figure, —OH ^* represents an active hydroxyl group.

Example 25
Example 25 is an example corresponding to the twenty-fifth embodiment. In Example 25, 50 parts by weight of polyisocyanate in which TDI and MDI were mixed in a ratio of 1: 1 (50:50 parts by weight) as a curing agent was added to 50 parts by weight of wood flour as a main agent, and mixed. Heated at ° C. As a result, the cellulose molecules in the wood flour were cross-linked with polyisocyanate to form a urethane bond, and curing proceeded rapidly. The reaction formula at this time is represented by the following formula (4).
2 Cel-OH + OCN-R-NCO → Cel-O-OCHN-R-NHCO-O-Cel (4)
In the formula, “Cel” represents a cellulose molecule (Cellulose).

Embodiment 26
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 26 will be described. The curable plastic binder composition according to Embodiment 26 uses, in Embodiment 25, etherified cellulose as a cellulose derivative obtained by etherifying cellulose as cellulose as the main agent. Specifically, the etherified cellulose as the main agent activates the hydroxyl groups by etherifying the hydroxyl groups of natural cellulose, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is ½ or more. It is a cellulose derivative. Examples of the etherified (R ″) cellulose include carboxymethyl cellulose (CMC: —CH ₂ COONa), methyl cellulose (MC: —CH ₃ ), ethyl cellulose (EC: —CH ₂ CH ₃ ), cyanoethyl cellulose (CyEC: It is possible to use hydroxyalkyl cellulose and derivatives thereof such as CH ₂ CH ₂ CN) and hydroxyethyl cellulose (HEC: —CH ₂ CH ₂ OH), Cellulose- (CH ₂ ) ₂ OH, ethyl hydroxyethyl cellulose, hydroxypropyl methyl cellulose and the like. it can. Thus, the esterification cellulose which increased the number of active hydroxyl groups of the cellulose surface by etherifying the hydroxyl group of a natural cellulose is produced | generated. The curable plastic binder composition according to Embodiment 26 is cured by mixing such esterified cellulose as a main agent and the same polyisocyanate as in Embodiment 1 as a curing agent. For example, crude carboxymethylcellulose is prepared by adding NaOH, isopropanol and water to wood flour as cellulose and stirring, and further adding sodium monochloroacetate and reacting at a predetermined temperature for a predetermined time. Further, carboxymethylcellulose is prepared by adding NaCl, glycolic acid, water and isopropylopanol to the crude carboxymethylcellulose and filtering. As the said predetermined temperature and predetermined time, it can be set as about 2 hours in the temperature range of 70-80 degreeC, for example. Then, with respect to a predetermined part by weight of the etherified cellulose, a mixture obtained by mixing TDI and MDI as a polyisocyanate at a ratio of 1: 1 is added to the same part by weight as the etherified cellulose, and the mixture is heated at a predetermined heating temperature. Then, in the same manner as in Embodiment 25, a plurality of active hydroxyl groups on the surface of etherified cellulose and polyisocyanate are bonded by urethane to form a three-dimensional network structure and harden. At this time, etherified cellulose has a higher number of active hydroxyl groups and higher reactivity than ordinary natural cellulose. The heating temperature at this time is in the range from 100 ° C. to 200 ° C., for example, 150 ° C., as in the case of the twenty-fifth embodiment. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 26 is shown in FIG. As shown in FIG. 32, in Embodiment 26, polyisocyanate (liquid) is crosslinked between active hydroxyl groups of the general structure (fiber) of etherified cellulose (crystal). In the figure, —OH ^* represents an active hydroxyl group.

Example 26
Example 26 is an example corresponding to the twenty-sixth embodiment. In Example 26, NaOH, isopropanol and water were added to the wood flour as cellulose as the main agent and stirred, and sodium monochloroacetate was further added to this mixture and reacted at a temperature of 70 to 80 ° C. for 2 hours. A crude carboxymethyl cellulose was prepared. In addition, carboxymethyl cellulose was prepared by adding NaCl, glycolic acid, water and isopropylopanol to the prepared crude carboxymethyl cellulose and filtering. Then, 50 parts by weight of a mixture of TDI and MDI in a ratio of 1: 1 (50:50 parts by weight) as a curing agent is added to 50 parts by weight of carboxymethylcellulose as the main agent prepared, and mixed at 150 ° C. Heated. As a result, the molecules of carboxymethyl cellulose were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. The reaction formula at this time is also expressed by the above formula (4). In Example 26, for the curable bioplastic binder using carboxymethylcellulose as the main agent and the curable bioplastic binder using wood flour as the main agent, the bond vibration (reaction rate) of the urethane bond when cured at room temperature is Fourier transformed. This was measured by a conversion infrared spectrometer (FT / IR-6100 manufactured by JASCO). The result is shown in FIG. The reaction rate was determined with 100% heat cured. As shown in FIG. 33, it can be seen that esterification increased the activity of the hydroxyl group and increased the reaction rate.

Embodiment 27
A solid-liquid curable plastic binder composition and a cured product thereof according to Embodiment 27 will be described. In the curable plastic binder composition according to Embodiment 27, the etherified cellulose of Embodiment 26 described above and the amorphous starch (physically modified starch) of Embodiment 4 are used as cellulose as the main agent in Embodiment 25. Amorphous etherified cellulose as activated cellulose further physically modified by the same method is used. Specifically, this amorphous etherified cellulose weakens the hydrogen bond between etherified cellulose molecules by impact-pulverizing etherified cellulose obtained by etherifying the hydroxyl group of natural cellulose to destroy the crystal structure. As a result, the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is set to 1/2 or more. Of course, since the amorphous etherified cellulose used in the embodiment 27 is obtained by further activating the etherified cellulose of the embodiment 26, even more active hydroxyl groups than the etherified cellulose of the embodiment 26 Can be increased, and the curing reactivity can be further improved. As described above, the etherified cellulose obtained by etherifying the hydroxyl group of natural cellulose as in the embodiment 27 is further amorphized as in the embodiment 4, so that the adjacent α-glucose in the cellulose is mainly used. Hydrogen bonds between the hydroxyl groups at the C2 and C3 positions of the compound are weakened, and amorphous etherified cellulose in which the hydroxyl groups are further activated is generated.

The curable plastic binder composition according to Embodiment 27 is cured by mixing such amorphous etherified cellulose as a main agent and the same polyisocyanate as in Embodiment 1 as a curing agent. That is, a plurality of active hydroxyl groups on the surface of amorphous etherified cellulose and a polyisocyanate are urethane-bonded to form a three-dimensional network structure and harden. At this time, amorphous etherified cellulose such as CMC has a higher number of active hydroxyl groups than ordinary natural cellulose, and is water-soluble and has good dispersibility, and therefore has very high reactivity. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 27 is shown in FIG. As shown in FIG. 34, in Embodiment 27, polyisocyanate (liquid) is crosslinked between active hydroxyl groups of the general structure (fiber) of amorphous etherified cellulose (non-crystalline). In the figure, —OH ^* represents an active hydroxyl group.

Embodiment 28.
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 28 will be described. The curable plastic binder composition according to Embodiment 28 is a one-pack type normal temperature or thermosetting bioplastic binder composition in which cellulose as a main agent and block isocyanate as a curing agent or a crosslinking agent are mixed in advance. . As the cellulose of the present invention, activated cellulose having a ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface of ½ or more is used as in the case of Embodiment 25. The blocked isocyanate is stabilized by being mixed and dispersed with the cellulose in a state where the polyisocyanate is blocked with a predetermined blocking agent. On the other hand, when the one-component curable plastic binder composition is heated to a predetermined temperature or more, the blocking agent of the blocked isocyanate is dissociated and the isocyanate group is unblocked, and the isocyanate group of the polyisocyanate is activated. It binds to the active hydroxyl group of cellulose and crosslinks cellulose molecules. Thereby, the curable plastic binder composition is cured. That is, by heating the curable plastic binder composition, the blocking agent of the blocked isocyanate is removed and the isocyanate group is activated, and a plurality of active hydroxyl groups on the cellulose surface are combined with the isocyanate group of the polyisocyanate (even at room temperature). By urethane bonding, cellulose molecules are cross-linked by polyisocyanate, and a three-dimensional network structure is formed and cured, and a curable resin molded product as a cured product is quickly and efficiently generated. In addition, the heating temperature at this time shall be the range of 100 to 200 degreeC, for example, can be 180 degreeC or more. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 28 is shown in FIG. As shown in FIG. 35, in Embodiment 28, the general structure (fiber) of cellulose (crystal) and the blocked isocyanate (liquid) are mixed and dispersed, and the polyisocyanate is bonded between the active hydroxyl groups of cellulose by removing the blocking agent. It is designed to crosslink. In the figure, —OH ^* represents an active hydroxyl group.

Example 28
Example 27 is an example corresponding to the twenty-eighth embodiment. In Example 27, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, 90 parts by weight of the blocked isocyanate as a curing agent was added to and mixed with 50 parts by weight of wood flour as cellulose as the main agent to prepare a one-pack type curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the cellulose molecules in the wood flour were cross-linked with polyisocyanate to form a urethane bond, and curing proceeded rapidly. The reaction formula at this time is represented by the following formula (5).
BL-OCHN-R-NHCO-BL ⇔ 2 BL + OCN-R-NCO
2 Cel-OH + OCN-R-NCO → Cel-O-OCHN-R-NHCO-O-Cel (5)
In addition, as a blocking agent, the same thing as Embodiment 9 can be used.

Embodiment 29.
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 29 will be described. The curable plastic binder composition according to Embodiment 29 uses the same etherified cellulose as in Embodiment 26 as cellulose as the main agent in Embodiment 28. That is, in Embodiment 29, as the cellulose, etherification is performed by activating the hydroxyl group of natural cellulose by etherification so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is 1/2 or more. Cellulose is used, and this etherified cellulose is mixed with the blocked isocyanate to form a one-component type. Such a one-pack type curable plastic binder composition is heated to a predetermined temperature or higher in the same manner as in the above-described Embodiment 28, so that the blocked agent of the blocked isocyanate is dissociated as in the above-mentioned Embodiment 28. Unblock the group and activate the polyisocyanate to crosslink the cellulose molecules of the etherified cellulose. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 29 is shown in FIG. As shown in FIG. 36, in Embodiment 29, the general structure (fiber) of etherified cellulose (crystal) and the blocked isocyanate (liquid) are mixed and dispersed, and the polyisocyanate is made of etherified cellulose by removing the blocking agent. The active hydroxyl groups are cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

Example 28
Example 28 is an example corresponding to the twenty-ninth embodiment. In Example 28, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, NaOH, isopropanol and water are added to the wood flour as cellulose, which is the main agent, and the mixture is stirred. Further, sodium monochloroacetate is added to this mixture and reacted at a temperature of 70 to 80 ° C. for 2 hours. Carboxymethylcellulose was prepared. In addition, carboxymethyl cellulose was prepared by adding NaCl, glycolic acid, water and isopropylopanol to the prepared crude carboxymethyl cellulose and filtering. Then, 90 parts by weight of the blocked isocyanate as a curing agent was added to and mixed with 50 parts by weight of carboxymethylcellulose as the main agent thus prepared to prepare a one-component curable plastic binder composition. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the cellulose molecules of the etherified cellulose were cross-linked with the polyisocyanate to form a urethane bond, and the curing proceeded rapidly. The reaction formula at this time is also expressed by the formula (5).

Embodiment 30
A one-component curable plastic binder composition and a cured product thereof according to Embodiment 30 will be described. The curable plastic binder composition according to Embodiment 30 uses the amorphous etherified cellulose of Embodiment 27 as the cellulose as the main agent in Embodiment 28. The curable plastic binder composition according to the embodiment 30 is mixed with the amorphous etherified cellulose as a main component and the same block isocyanate as that in the embodiment 28 as a curing agent, so that the block isocyanate has a predetermined amount of polyisocyanate. In the state blocked with a blocking agent, it is mixed and dispersed with the amorphous etherified cellulose and stabilized. On the other hand, when the one-component curable plastic binder composition is heated to a predetermined temperature or more, the blocking agent of the blocked isocyanate is dissociated and the isocyanate group is unblocked, and the isocyanate group of the polyisocyanate is activated. Bonds with active hydroxyl group of amorphous etherified cellulose to crosslink cellulose molecules. Thereby, the curable plastic binder composition is cured. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 30 is shown in FIG. As shown in FIG. 37, in Embodiment 30, the general structure (fiber) of amorphous etherified cellulose (non-crystalline) and blocked isocyanate (liquid) are mixed and dispersed, and the polyisocyanate is converted into amorphous ether by removing the blocking agent. The activated hydroxyl groups of the fluorinated cellulose are cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

Embodiment 31
The one-pack type aqueous curable plastic binder composition and the cured product thereof according to Embodiment 31 will be described. The curable plastic binder composition according to Embodiment 31 includes colloidal esterified cellulose as colloidal cellulose that has been added to esterified cellulose as a main agent to form a sol or gel, and a block as a curing agent or a crosslinking agent. It is a one-component room temperature or thermosetting bioplastic binder composition premixed with isocyanate. Colloidal esterified cellulose is made into a sol or gel by hydrolyzing esterified cellulose as the main agent with the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface being 1/2 or more. ) It is colloidal. The blocked isocyanate is the same as in Embodiment 9 described above, and is mixed and dispersed with the colloidal esterified cellulose in a state where polyisocyanate is blocked with a predetermined blocking agent (forward micelle or reverse micelle). E) Emulsified and stabilized. That is, in Embodiment 31, a block isocyanate (usually hydrophobic) is colloidal esterified cellulose (sol or gel) without adding or mixing an emulsifier or dispersant such as a surfactant. Forms a normal micelle emulsion, and block isocyanate is dispersed in colloidal esterified cellulose in a stable and uniform manner. Conversely, block isocyanate forms colloidal esterified cellulose and reverse micelle emulsion. The colloidal esterified cellulose is stably and uniformly dispersed in the form of particles in the blocked isocyanate. This is thought to be due to the hydrogen bonding of the hydroxyl groups of the cellulose molecules due to the sol or gelation of cellulose. On the other hand, when such a one-pack type curable plastic binder composition is heated to a predetermined temperature or higher, the water in the colloidal esterified cellulose is first evaporated, and hydrogen bonds in the cellulose sol or cellulose gel are released. Subsequently, the blocking agent of the blocked isocyanate is dissociated to unblock the isocyanate group, the isocyanate group of the polyisocyanate is activated and bonded to the active hydroxyl group of the esterified cellulose, and the cellulose molecules are crosslinked. Thereby, a curable plastic binder composition hardens | cures and produces | generates the curable resin molding as a final hardened | cured material rapidly and efficiently. In addition, the heating temperature at this time shall be the range of 100 to 200 degreeC, for example, can be 180 degreeC or more. Here, as the blocking agent, it is particularly preferable to use an oxime blocking agent. In this case, emulsification of blocked isocyanate and colloidal esterified cellulose can be carried out very smoothly and stably. On the other hand, when using alcohol-based blocking agents, ethanol-based ones are less preferred because they can stably emulsify blocked isocyanates and colloidal esterified cellulose. Use methanol-based ones as described above. It is preferable to do. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 31 is shown in FIG. As shown in FIG. 38, in Embodiment 31, the general structure (fiber) of esterified cellulose (crystal) and the blocked isocyanate (liquid) are mixed and dispersed, and the polyisocyanate is mixed with the esterified cellulose by removing the blocking agent. The active hydroxyl groups are cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

Example 29
Example 29 is an example corresponding to Embodiment 31. In Example 29, 40 parts by weight of a blocking agent was added to 50 parts by weight of polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and 90 parts of blocked isocyanate was added. A part by weight was prepared. Next, after adding DMF (dimethylformamide) / SO ₃ (anhydrous sulfuric acid) to the wood flour as cellulose and stirring at a temperature of 0 to 30 ° C. for 4 hours, NaOH, water and methanol are added to form a main agent. Cellulose sulfate as esterified cellulose was prepared. Moreover, 300-500 weight part of water was added with respect to 50 weight part of prepared cellulose sulfate, and it heated and gelatinized at 80 degreeC, and prepared the colloidal cellulose. Then, 90 parts by weight of the blocked isocyanate is added to the colloidal cellulose as a curing agent, mixed, and stirred at a high speed, whereby a one-component curable plastic binder composition in which a forward micelle structure emulsion is stably generated. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecules of cellulose sulfate were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of cellulose sulfate as a main ingredient is added to 120 parts by weight of the blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to the mixture and the mixture is stirred at a low speed, thereby reverse micelles. A one-part curable plastic binder composition in which an emulsion having a structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. Thereby, the molecules of cellulose sulfate were cross-linked by polyisocyanate to form a urethane bond, and the curing proceeded rapidly.

In any of the above cases, the reaction formula is represented by the following formula (6).
Cel-OH ---- H ₂ O → Cel-OH + H ₂ O ↑
BL-OCHN-R-NHCO-BL ⇔ 2 BL + OCN-R-NCO
2 Cel-OH + OCN-R-NCO → Cel-O-OCHN-R-NHCO-O-Cel (6)

Embodiment 32.
A one-component aqueous curable plastic binder composition and a cured product thereof according to Embodiment 32 will be described. The curable plastic binder composition according to Embodiment 31 includes colloidal etherified cellulose as colloidal cellulose hydrated or gelated with etherified cellulose as the main agent, and a block as a curing agent or a crosslinking agent It is a one-component room temperature or thermosetting bioplastic binder composition premixed with isocyanate. The colloidal etherified cellulose may be in the form of a sol or gel (sol or gel) colloid obtained by hydrothermally heating the etherified cellulose of Embodiment 27. Further, the blocked isocyanate is the same as in Embodiment 9 described above, and is mixed and dispersed with the colloidal etherified cellulose in a state where the polyisocyanate is blocked with a predetermined blocking agent (forward micelle or reverse micelle). E) Emulsified and stabilized. That is, in Embodiment 32, the (usually hydrophobic) blocked isocyanate is mixed with the colloidal etherified cellulose (sol or gel) without adding or mixing an emulsifier or dispersant such as a surfactant. Forms a normal micelle emulsion, and blocked isocyanate is dispersed uniformly and uniformly in colloidal etherified cellulose. Conversely, blocked isocyanate forms a reverse micelle emulsion with colloidal etherified cellulose. The colloidal etherified cellulose is stably and uniformly dispersed in the form of particles in the blocked isocyanate. On the other hand, when such a one-component curable plastic binder composition is heated to a predetermined temperature or higher, the water content of the colloidal etherified cellulose is first evaporated, and hydrogen bonds in the cellulose sol or cellulose gel are released. Subsequently, the blocking agent of the blocked isocyanate is dissociated to unblock the isocyanate group, the isocyanate group of the polyisocyanate is activated and bonded to the active hydroxyl group of the etherified cellulose, and the cellulose molecules are crosslinked. Thereby, a curable plastic binder composition hardens | cures and produces | generates the curable resin molding as a final hardened | cured material rapidly and efficiently. In addition, the heating temperature at this time shall be the range of 100 to 200 degreeC, for example, can be 180 degreeC or more. Here, as the blocking agent, it is particularly preferable to use an oxime blocking agent. In this case, emulsification of blocked isocyanate and colloidal esterified cellulose can be carried out very smoothly and stably. On the other hand, when using alcohol-based blocking agents, ethanol-based ones are less preferred because they can stably emulsify blocked isocyanates and colloidal esterified cellulose. Use methanol-based ones as described above. It is preferable to do. A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 32 is shown in FIG. As shown in FIG. 39, in Embodiment 32, the general structure (fiber) of etherified cellulose (crystal) and the blocked isocyanate (liquid) are mixed and dispersed, and the polyisocyanate is made of etherified cellulose by removing the blocking agent. The active hydroxyl groups are cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

Example 30
Example 30 is an example corresponding to the thirty-second embodiment. In Example 30, 40 parts by weight of a blocking agent was added to 50 parts by weight of a polyisocyanate in which TDI and MDI were mixed at a ratio of 1: 1 (50:50 parts by weight) to block the isocyanate group, and A part by weight was prepared. Next, NaOH, isopropanol and water are added to the wood flour as cellulose, which is the main agent, and the mixture is stirred. Further, sodium monochloroacetate is added to this mixture and reacted at a temperature of 70 to 80 ° C. for 2 hours. Carboxymethylcellulose was prepared. In addition, carboxymethyl cellulose was prepared by adding NaCl, glycolic acid, water and isopropylopanol to the prepared crude carboxymethyl cellulose and filtering. And 300-500 weight part of water was added with respect to 50 weight part of carboxymethylcellulose as a prepared main ingredient, and it heated and gelatinized at 80 degreeC, and prepared the colloidal cellulose. Then, 90 parts by weight of the blocked isocyanate is added to the colloidal cellulose as a curing agent, mixed, and stirred at a high speed, whereby a one-component curable plastic binder composition in which a forward micelle structure emulsion is stably generated. Was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of carboxymethyl cellulose were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly.

  On the other hand, 70 parts by weight of a blocking agent is added to 50 parts by weight of polyisocyanate in which TDI and MDI are mixed in a ratio of 1: 1 (50:50 parts by weight) to block isocyanate groups, and 120 parts by weight of blocked isocyanate is prepared. did. Next, 50 parts by weight of carboxymethyl cellulose as a main ingredient is added to 120 parts by weight of the blocked isocyanate and stirred, and further, 1 to 500 parts by weight of water is added to the mixture, and the mixture is stirred at a low speed, thereby reverse micelles. A one-part curable plastic binder composition in which an emulsion having a structure was stably produced was prepared. And at the time of use, this 1 liquid type curable plastic binder composition was heated at 180 degreeC. As a result, the molecules of carboxymethylcellulose were cross-linked by polyisocyanate to form a urethane bond, and curing proceeded rapidly. The reaction formula in either case is represented by the above formula (6).

Embodiment 33.
A one-component aqueous curable plastic binder composition and a cured product thereof according to Embodiment 33 will be described. The curable plastic binder composition according to the thirty-third embodiment activates the hydroxyl group by pulverizing the etherified cellulose of the twenty-seventh embodiment to break the crystal structure as cellulose as the main agent, thereby activating the hydroxyl group. Amorphized amorphous etherified cellulose is used. Then, colloidal amorphous etherified cellulose is prepared as colloidal cellulose which is hydrated or gelated by adding to such amorphous etherified cellulose. The colloidal amorphous etherified cellulose is premixed with the same blocked isocyanate as in Embodiment 32 to constitute a one-pack type normal temperature or thermosetting bioplastic binder composition. The blocked isocyanate is mixed with the colloidal amorphous etherified cellulose in a state where the polyisocyanate is blocked with a blocking agent to form a forward micelle structure or reverse micelle structure emulsion, and the amorphous etherified cellulose is crosslinked by heating. . A cured structure or a crosslinked structure in the curable plastic binder composition according to Embodiment 33 is shown in FIG. As shown in FIG. 40, in Embodiment 33, the general structure (fibers) of amorphous etherified cellulose (non-crystalline) and the blocked isocyanate (liquid) are mixed and dispersed, and the polyisocyanate becomes amorphous ether by removing the blocking agent. The activated hydroxyl groups of the fluorinated cellulose are cross-linked. In the figure, —OH ^* represents an active hydroxyl group.

  By the way, in Examples 31-33 corresponding to the above-described Embodiments 31-33, various celluloses as the main agent are prepared in a gel form, which becomes a gel form over time through a sol-like stage. This means that if the gelled starch is stirred, it becomes sol again.

  Moreover, in the said Embodiment 31-33, it is preferable to prepare sol-form or gel-form cellulose (colloidal cellulose) so that PH shall be the range of 5-9. In this way, the cellulose gel or cellulose sol (colloidal cellulose) can be further stabilized.

  Further, when sol- or gel-like cellulose (colloidal cellulose) is used as a main agent as in the above-described embodiments 31 to 33, an oxime-based blocking agent such as a ketoxime-based blocking agent is used as a blocking agent for blocked isocyanate. It is preferable to use it. In this way, the emulsification of the blocked isocyanate (liquid) and the colloidal starch can be performed more smoothly and stable and uniform dispersion can be achieved.

  In Embodiments 25 to 33, when the cellulose is physically modified, for example, by making it amorphous, it is preferable to use a polyisocyanate having a predetermined size in order to crosslink between the celluloses. For example, various polyisocyanates have a size corresponding to the structure represented by the general formula (chemical structural formula), but selectively select a polyisocyanate having a size corresponding to the interval between active hydroxyl groups of cellulose used as the main agent. By using it, the crosslinking efficiency can be dramatically improved. Specifically, it is preferable to use, as the polyisocyanate, a polyisocyanate having a size corresponding to the intramolecular or intermolecular active hydroxyl group distance of the cellulose subjected to physical modification by hydroxyl group activation such as ball milling. More specifically, the size of the polyisocyanate is preferably in the range of 10 to 60 cm, almost the same as in the case of the starch. Here, in the case of modified cellulose, the intermolecular distance is larger than that of unmodified cellulose such as natural cellulose. Therefore, as the size of the polyisocyanate for modified cellulose, the larger side of the above range (for example, The range is preferably 30 to 60 cm, and in the case of unmodified cellulose such as natural cellulose, the range on the smaller side (for example, 10 to 30 cm) of the above range is preferable.

  By the way, the curable plastic binder composition according to the present invention can be mixed with additives for exhibiting a predetermined function, in addition to the main agent and the curing agent. For example, an accelerator for accelerating the curing reaction may be added. In this case, the reaction rate (curing rate) is further increased, the proportion of unreacted components is decreased, and the properties such as fire resistance are further improved. can do.

  In addition to the above, as the physical modified starch in the present invention, wet-heat treated starch, high-frequency treated starch, radiation-treated starch and the like can be used, and the chemically modified starch includes carboxymethyl starch, hydroxyalkyl. Etherified starch such as starch and cationic starch, cross-linked starch, oxidized starch, acid-modified starch and the like can be used, and enzyme-treated starch such as enzyme-degraded dextrin can also be used.

  Furthermore, the heating temperature at the time of curing in the curable bioplastic binder composition of the present invention is preferably within a range of 100 ° C. to 200 ° C. as described above. Therefore, the temperature is preferably 180 ° C. or higher. In addition, as a curing agent, it is preferable to increase the ratio of MDI from the viewpoint of various characteristics. However, when the ratio of MDI is increased, the heating temperature is set higher than the above temperature to improve curability (reactivity). From the point of view, it is preferable. Even in this case, the MDI is not vaporized by heating. On the other hand, when the ratio of TDI is increased as the curing agent, if the heating temperature is too high, TDI may be vaporized by heating. Therefore, the heating temperature is preferably lower than that for MDI.

Next, an example of a cured product obtained by curing the curable plastic binder composition of the present invention will be described. The cured product of the present invention can be formed into an arbitrary shape by curing the curable plastic binder composition of each of the above embodiments and examples. For example, the curable plastic binder composition of Example 8 can be used. The cured product obtained by curing is also flame retardant, as compared to polyurethane using the same polyisocyanate. Next, the data of the horizontal flame retardancy test based on JISD1201 are shown. Time indicates the burning time when an ester non-woven impregnated with each resin is burned. The shorter the burning time, the higher the flame retardancy.

  The curable plastic binder composition of the present invention can be suitably applied as a binder in the field where conventional petroleum-based curable resins are used, such as molding of automobile parts, etc. It can be suitably applied also in the adhesive field. In addition, it can be applied to any field where conventional resin binders are used.

FIG. 1 is an explanatory view schematically showing the structure of a general natural starch granule. FIG. 2 is a schematic diagram showing a crosslinked structure of the general structure (solid) of starch granules (crystals) according to Embodiment 1 of the present invention with polyisocyanate. FIG. 3 is a schematic diagram showing a crosslinked structure of alpha starch granules according to Embodiment 2 of the present invention by polyisocyanate. FIG. 4 is a schematic diagram showing a crosslinked structure of the pyrolyzed starch granules according to Embodiment 3 of the present invention with polyisocyanate. FIG. 5 is a schematic diagram showing a cross-linked structure of a general structure (solid) of amorphous starch granules (crystals) according to Embodiment 4 of the present invention with polyisocyanate. FIG. 6 is a schematic diagram showing a cross-linked structure of a general structure (solid) of esterified starch granules (crystals) according to Embodiment 5 of the present invention with polyisocyanate. FIG. 7 is a schematic diagram showing a cross-linked structure of alpha-esterified starch granules according to Embodiment 6 of the present invention using polyisocyanate. FIG. 8 is a schematic diagram showing a crosslinked structure of the pyrolyzed esterified starch granules according to Embodiment 7 of the present invention with polyisocyanate. FIG. 9 is a schematic diagram showing a crosslinked structure of a general structure (solid) of amorphous esterified starch granules (crystals) according to Embodiment 8 of the present invention with polyisocyanate. FIG. 10 is a graph showing an X-ray diffraction peak of amorphous esterified starch (amorphous acetyl tapioca starch) in Example 8 corresponding to Embodiment 8 of the present invention. FIG. 11 is a graph showing an X-ray diffraction peak of an esterified starch (acetyl tapioca starch) of a comparative example of Example 8 corresponding to Embodiment 8 of the present invention. FIG. 12 shows a curable bioplastic binder using amorphous acetyl tapioca starch as the main agent and a curable bioplastic binder using acetyl tapioca starch as the main agent in Example 8 corresponding to Embodiment 8 of the present invention. It is a graph which shows the coupling vibration of the urethane bond when it hardens | cures. FIG. 13 is a schematic diagram showing a crosslinked structure of a general structure (solid) of starch granules (crystals) according to Embodiment 9 of the present invention with polyisocyanate. FIG. 14 is a schematic diagram showing a crosslinked structure of alpha starch granules according to Embodiment 10 of the present invention by polyisocyanate. FIG. 15 is a schematic diagram showing a crosslinked structure of the pyrolyzed starch granules according to Embodiment 11 of the present invention with polyisocyanate. FIG. 16 is a schematic diagram showing a crosslinked structure of a general structure (solid) of amorphous starch granules (non-crystal) according to Embodiment 12 of the present invention with polyisocyanate. FIG. 17 is a schematic diagram showing a crosslinked structure of a general structure (solid) of esterified starch granules (crystals) according to Embodiment 13 of the present invention with polyisocyanate. FIG. 18 is a schematic diagram showing a crosslinked structure of amorphous esterified starch granules according to Embodiment 14 of the present invention by polyisocyanate. FIG. 19 is a schematic diagram showing a crosslinked structure of a pyrolyzed esterified starch granule according to Embodiment 15 of the present invention with polyisocyanate. FIG. 20 is a schematic diagram showing a crosslinked structure of a general structure (solid) of amorphous esterified starch granules (non-crystalline) according to Embodiment 16 of the present invention by polyisocyanate. FIG. 21 is a schematic diagram showing a cross-linked structure of a general structure (solid) of colloidal starch granules (crystals) according to Embodiment 17 of the present invention with a polyisocyanate. FIG. 22 is a schematic diagram showing a cross-linked structure of colloidal alpha starch granules according to Embodiment 18 of the present invention with polyisocyanate. FIG. 23 is a schematic diagram showing a cross-linked structure of a colloidal pyrolytic starch granule according to Embodiment 19 of the present invention by polyisocyanate. FIG. 24 is a schematic diagram showing a cross-linked structure of a colloidal amorphous starch granule according to Embodiment 20 of the present invention by polyisocyanate. FIG. 25 is an optical micrograph image showing a dispersion example of a forward micelle emulsion prepared under the conditions described in Embodiment 20 of the present invention. FIG. 26 is an optical micrograph image showing a dispersion example of an emulsion having a normal micelle structure prepared under conditions different from those described in Embodiment 20 as a comparative example of FIG. FIG. 27 is a schematic diagram showing a cross-linked structure of a general structure (solid) of a colloidal esterified starch granule (crystal) according to Embodiment 21 of the present invention with a polyisocyanate. FIG. 28 is a schematic diagram showing a cross-linked structure of colloidal alpha-esterified starch granules according to Embodiment 22 of the present invention by polyisocyanate. FIG. 29 is a schematic diagram showing a cross-linked structure of the colloidal pyrolyzed esterified starch granules according to Embodiment 23 of the present invention by polyisocyanate. FIG. 30 is a schematic diagram showing a cross-linked structure of a general structure (solid) of colloidal amorphous esterified starch granules (non-crystalline) according to Embodiment 24 of the present invention with a polyisocyanate. FIG. 31 is a schematic diagram showing a cross-linked structure of a general structure (fiber) of cellulose (crystal) according to Embodiment 25 of the present invention using polyisocyanate. FIG. 32 is a schematic diagram showing a crosslinked structure of a general structure (fiber) of etherified cellulose (crystal) according to Embodiment 26 of the present invention, using polyisocyanate. FIG. 33 shows a bond vibration of a urethane bond when cured at room temperature for a curable bioplastic binder using carboxymethyl cellulose as a main agent and a curable bioplastic binder using wood flour as a main agent in Embodiment 26 of the present invention. It is a graph which shows (reaction rate). FIG. 34 is a schematic diagram showing a crosslinked structure of polyisocyanate in a general structure (fiber) of amorphous etherified cellulose (non-crystalline) according to Embodiment 27 of the present invention. FIG. 35 is a schematic diagram showing a crosslinked structure of a general structure (fiber) of cellulose (crystal) according to Embodiment 28 of the present invention using polyisocyanate. FIG. 36 is a schematic diagram showing a crosslinked structure of a general structure (fiber) of etherified cellulose (crystal) according to Embodiment 29 of the present invention by polyisocyanate. FIG. 37 is a schematic diagram showing a crosslinked structure of polyisocyanate in the general structure (fiber) of amorphous etherified cellulose (non-crystalline) according to Embodiment 30 of the present invention. FIG. 38 is a schematic diagram showing a crosslinked structure of a general structure (fiber) of esterified cellulose (crystal) according to Embodiment 31 of the present invention by polyisocyanate. FIG. 39 is a schematic diagram showing a crosslinked structure of a general structure (fiber) of etherified cellulose (crystal) according to Embodiment 32 of the present invention by polyisocyanate. FIG. 40 is a schematic diagram showing a crosslinked structure of polyisocyanate in a general structure (fiber) of amorphous etherified cellulose (non-crystalline) according to Embodiment 33 of the present invention.

Claims (28)

An activated starch as a main agent in which the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface of the starch granules is increased from that of non-activated starch;
A solid-liquid curable bioplastic binder composition comprising polyisocyanate as a curing agent for crosslinking the activated starch.   As the activated starch, the starch is hydrolyzed and gelled, and then rapidly heat-dried and alphalated to activate the hydroxyl groups, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is reduced to 1/2. The above-mentioned alpha starch, starch is thermally decomposed to activate the hydroxyl groups, and the pyrolyzed starch, starch, in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 1/2 or more, is impact pulverized. Any one or more of amorphous starches having activated the hydroxyl groups by destroying the crystal structure and having the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules being 1/2 or more are used. Item 2. The solid-liquid curable bioplastic binder composition according to Item 1.   As the activated starch, an esterified starch in which the hydroxyl group of the starch is activated by esterification to activate the hydroxyl group and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is 40% or more is used. The solid-liquid curable bioplastic binder composition according to claim 1.   As the activated starch, the esterified starch obtained by esterifying the hydroxyl group of starch is heated and gelled, and then rapidly heat-dried and alphalated by rapid thermal drying. By thermally decomposing esterified starch that has been esterified, pyrolyzed esterified starch whose hydroxyl groups have been activated, and esterified starch that has been esterified with hydroxyl groups of starch are impact-pulverized to destroy the crystal structure. 2. The solid-liquid curable bioplastic binder composition according to claim 1, wherein any one or more of amorphous esterified starch activated with a hydroxyl group is used. An activated starch as a main agent in which the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface of the starch granules is increased from that of non-activated starch;
A one-component type comprising a block isocyanate as a curing agent which is mixed and dispersed with the activated starch in a state where the polyisocyanate is blocked with a blocking agent and which crosslinks the activated starch by normal temperature or heating. Curable bioplastic binder composition.   As the activated starch, the starch is hydrolyzed and gelled, and then rapidly heat-dried and alphalated to activate the hydroxyl groups, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is reduced to 1/2. The above-mentioned alpha starch, starch is thermally decomposed to activate the hydroxyl groups, and the pyrolyzed starch, starch, in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 1/2 or more, is impact pulverized. Any one or more of amorphous starches having activated the hydroxyl groups by destroying the crystal structure and having the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules being 1/2 or more are used. Item 6. A one-component curable bioplastic binder composition according to Item 5.   As the activated starch, an esterified starch in which the hydroxyl group of the starch is activated by esterification to activate the hydroxyl group and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules is 40% or more is used. 6. The one-component curable bioplastic binder composition according to claim 5,   As the activated starch, the esterified starch obtained by esterifying the hydroxyl group of starch is heated and gelled, and then rapidly heat-dried and alphalated by rapid thermal drying. By thermally decomposing esterified starch that has been esterified, pyrolyzed esterified starch whose hydroxyl groups have been activated, and esterified starch that has been esterified with hydroxyl groups of starch are impact-pulverized to destroy the crystal structure. 6. The one-component curable bioplastic binder composition according to claim 5, wherein any one or more of the amorphous esterified starch having activated hydroxyl groups and activated the hydroxyl groups is used. Colloidal starch obtained by hydrothermally heating activated starch as a main ingredient, in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of starch granules is increased from that of non-activated starch,
The polyisocyanate is mixed with the colloidal starch in a state blocked with a blocking agent to be emulsified, and is composed of blocked isocyanate as a curing agent that crosslinks the activated starch by room temperature or heating. One-pack type aqueous curable bioplastic binder composition.   As the activated starch, the starch is hydrolyzed and gelled, and then rapidly heat-dried and alphalated to activate the hydroxyl groups, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is reduced to 1/2. The above-mentioned alpha starch, starch is thermally decomposed to activate the hydroxyl groups, and the pyrolyzed starch, starch, in which the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the starch granule surface is 1/2 or more, is impact pulverized. Using one or more of the amorphous starches that activate the hydroxyl groups by destroying the crystal structure and make the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules ½ or more. 10. The one-part aqueous curable bioplastic binder composition according to claim 9, wherein the colloidal starch is prepared by solification or gelation.   As the activated starch, an esterified starch in which the hydroxyl group is activated by esterifying the starch to make the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface of the starch granules 40% or more is used. 10. The one-part aqueous curable bioplastic binder composition according to claim 9, wherein the colloidal starch is prepared by adding water to starch to form a sol or gel.   As the activated starch, the esterified starch obtained by esterifying the hydroxyl group of starch is hydrolyzed and gelled, and then rapidly heat-dried and alphalated to activate the hydroxylated starch, the hydroxyl group of starch. By thermally decomposing esterified starch that has been esterified, pyrolyzed esterified starch whose hydroxyl groups have been activated, and esterified starch that has been esterified with hydroxyl groups of starch are impact-pulverized to destroy the crystal structure. The colloidal starch is prepared by activating a hydroxyl group and using any one or more of the amorphous esterified starch activated by the hydroxyl group, and adding the starch to a sol or gel by adding to the starch. The one-component aqueous curable bioplastic binder composition according to claim 9.   The one-part aqueous curable bioplastic binder composition according to any one of claims 9 to 12, wherein PH of the colloidal starch is in the range of 5-9.   The one-component aqueous curable bioplastic binder composition according to any one of claims 9 to 12, wherein an oxime-based blocking agent is used as the blocking agent.   The curable bioplastic binder composition according to any one of claims 1 to 11, wherein a polyisocyanate having a size corresponding to a distance between active hydroxyl groups of the activated starch is used as the polyisocyanate. Activated cellulose as a main agent in which the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface is increased from that of non-activated cellulose;
A solid-liquid curable bioplastic binder composition comprising polyisocyanate as a curing agent for crosslinking the activated cellulose.   As the activated cellulose, an etherified cellulose is used in which the hydroxyl group is activated by etherifying the cellulose so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is 1/2 or more. Item 18. A solid-liquid curable bioplastic binder composition according to Item 16.   As the activated cellulose, etherified cellulose obtained by etherifying cellulose is subjected to impact pulverization to destroy the crystal structure, thereby activating the hydroxyl groups so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface is 1/2 or more. The solid liquid curable bioplastic binder composition according to claim 16, wherein the amorphous etherified cellulose is used. Activated cellulose as a main agent in which the ratio of the number of active hydroxyl groups in the total number of hydroxyl groups on the surface is increased from that of non-activated cellulose;
A one-component type comprising a block isocyanate as a curing agent which is mixed and dispersed with the activated cellulose in a state where the polyisocyanate is blocked with a blocking agent and which crosslinks the activated cellulose by normal temperature or heating. Curable bioplastic binder composition.   As the activated cellulose, an etherified cellulose is used in which the hydroxyl group is activated by etherifying the cellulose so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the cellulose surface is 1/2 or more. Item 20. A one-component curable bioplastic binder composition according to Item 19.   As the activated cellulose, etherified cellulose obtained by etherifying cellulose is subjected to impact pulverization to destroy the crystal structure, thereby activating the hydroxyl groups so that the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface is 1/2 or more. 20. The one-part curable bioplastic binder composition according to claim 19, wherein the amorphous etherified cellulose is used. Colloidal form in which the hydroxyl group is activated by esterification of cellulose, and the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface is increased from that of non-activated cellulose to the esterified cellulose as the main agent to form a sol or gel Colloidal esterified cellulose as cellulose;
The polyisocyanate is mixed with the colloidal esterified cellulose in a state blocked with a blocking agent to be emulsified, and at the same time comprises a blocked isocyanate as a curing agent that crosslinks the esterified cellulose by room temperature or heating. A one-component aqueous curable bioplastic binder composition. Colloidal form obtained by activating the hydroxyl group by etherification treatment of cellulose and adding it to etherified cellulose as the main agent which increased the ratio of the number of active hydroxyl groups to the total number of hydroxyl groups on the surface compared to non-activated cellulose. Colloidal etherified cellulose as cellulose;
The polyisocyanate is blocked with a blocking agent, mixed with the colloidal etherified cellulose to be emulsified, and at the same time comprises a blocked isocyanate as a curing agent that crosslinks the etherified cellulose by room temperature or heating. A one-component aqueous curable bioplastic binder composition. Cellulose etherified cellulose is impact-pulverized and its crystal structure is destroyed by pulverization to activate its hydroxyl group, which is then added to amorphous etherified cellulose as the main agent that activates the hydroxyl group to form a sol or gel. Colloidal amorphous etherified cellulose as colloidal cellulose;
It is mixed with the colloidal amorphous etherified cellulose and emulsified in a state where the polyisocyanate is blocked with a blocking agent, and comprises a blocked isocyanate as a curing agent that crosslinks the amorphous etherified cellulose by room temperature or heating. A one-component aqueous curable bioplastic binder composition.   25. The one-part water-based curable bioplastic binder composition according to any one of claims 22 to 24, wherein the colloidal cellulose has a pH of 5 to 9.   The one-component water-based curable bioplastic binder composition according to any one of claims 22 to 24, wherein an oxime-based blocking agent is used as the blocking agent.   The curable bioplastic binder composition according to any one of claims 17 to 23, wherein a polyisocyanate having a size corresponding to a distance between active hydroxyl groups of the cellulose is used as the polyisocyanate.   A cured product produced by reacting and curing the curable bioplastic binder composition according to any one of claims 1 to 27 at room temperature or by heating.