JPH1077395A - Biodegradable resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition, excellent in flexibility and biodegradability and usable in applications such as containers, etc., by mixing an aliphatic polyester having a specific melt viscosity with a specified amount of biodegradable organic fine particles. SOLUTION: This biodegradable resin composition is obtained by mixing and reacting (A) 100 pts.wt. aliphatic polyester having 1,000-150,000P melt viscosity at 200 deg.C with (B) 10-260 pts.wt. biodegradable organic fine particles and (C) 0.5-10 pts.wt. polyfunctional isocyanate compound. One or more of starches, wood flour, etc., are preferably used as the component B; however, the starches having a high biodegradation rate are more preferably used. Diisocyanates, trisocyanates, etc., are preferably used as the component C; however, one or more of the diisocyanates are more preferably used. Since the resultant composition has excellent flexibility, rigidity, biodegradability, etc., and is relatively inexpensive, a wide range of used such as films, containers or fibers can thereby be expected.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a biodegradable polyester composition having excellent flexibility and biodegradability and suitably used for a wide range of uses such as films, containers and fibers.

[0002]

2. Description of the Related Art In recent years, biodegradable polymers that can be decomposed by microorganisms and the like have attracted attention as social demands for environmental conservation have increased. Specific examples of the biodegradable polymer include melt-moldable aliphatic polyesters such as polyhydroxybutyrate, polycaprolactone, polylactic acid, and polybutylene succinate.

[0003] However, microbial-producing biodegradable polymers such as polyhydroxybutyrate are extremely expensive and can be obtained using chemical synthesis techniques such as polycaprolactone, polylactic acid, polybutylene succinate and the like. The cost of biodegradable polymers is also two to three times higher than general-purpose resins such as olefin-based resins, and these cost issues hinder the versatility of biodegradable polymers. It is.

[0004] In order to address the above problems, a biodegradable polymer is blended with an inexpensive organic extender (for example, starches) or an inorganic extender (for example, an inorganic filler such as talc or calcium carbonate). Various attempts have been made to reduce the cost of biodegradable polymers.

[0005] For example, in Japanese Patent Application Laid-Open No. 5-32822, it is known that "a polysaccharide such as starch is composed of 90 to 10% by weight and a modified ethylene-vinyl alcohol copolymer having an ionic group at a terminal is 10 to 90% by weight. A disintegrable resin composition "has been proposed, and Japanese Patent Application Laid-Open No. 4-353535 discloses a composition having" a composition having an ethylene content of 20 to 60 mol%, a degree of saponification of vinyl acetate units of 90 mol% or less, and Melting point is 1
Biodegradable resin composition comprising partially saponified ethylene-vinyl acetate copolymer having a temperature of 50 ° C. or lower and a starch-based polymer ”
Further, Japanese Patent Application Laid-Open No. Hei 4-248851 discloses that “aliphatic polyester resin 20 to 80% by weight”.
And a biodegradable composition comprising 80 to 20% by weight of vegetable protein and / or starch.

However, the biodegradable compositions according to the above series of proposals have poor compatibility between an ethylene-vinyl acetate resin or an aliphatic polyester resin used as a binder resin and starches, and therefore have poor moldability and physical properties, particularly There is a problem that flexibility is poor and lacks practicality.

In Japanese Patent Application Laid-Open No. 7-102114,
"A biodegradable composition containing a cellulose ester, a starch and a plasticizer, wherein the content of the plasticizer in the biodegradable composition is 30 to 70% by weight, and the weight ratio of the cellulose ester to the starch is 99: 1 to 20:80, a biodegradable composition "has been proposed.

[0008] However, the biodegradable composition proposed above has a drawback of poor rigidity because it contains a large amount of a plasticizer, although the compatibility between the cellulose ester used as a binder resin and the starches is good. In addition, when used for films and containers, there is a concern that the plasticizer may be eluted (bleathing), which limits the practical use.

Japanese Patent Application Laid-Open No. 7-70367 discloses a biodegradable resin containing at least one hydroxycarboxylate and containing at least one thermoplastic starch and at least one thermoplastic aliphatic polyester. Molding compositions "have been proposed.

However, since the biodegradable composition proposed above uses a thermoplastic starch, that is, a gelatinized starch, the physical properties are degraded due to hydrolysis of the aliphatic polyester at the time of molding, or the molded product is heated. It is not practical due to concerns about deterioration.

As described above, while having excellent flexibility, rigidity, biodegradability, etc., films and containers,
Biodegradable compositions suitably used for a wide range of uses such as fibers have not been put to practical use.

[0012]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned conventional problems by providing excellent flexibility and biodegradability, as well as being relatively inexpensive and suitable for use in a wide range of applications. It is an object to provide a polyester composition.

[0013]

Means for Solving the Problems The biodegradable polyester composition according to the invention of claim 1 (hereinafter referred to as "first invention") is used in an amount of 100 parts by weight of the following component (a).
10-260 parts by weight of component (b) and 0.5-component (c)
It is characterized in that 10 parts by weight are mixed and reacted. Component (a): a melt viscosity at 200 ° C. of 1000 to 1
Aliphatic polyester having 50,000 poise (b) component: biodegradable organic fine particles (c) component: polyfunctional isocyanate compound

Specific examples of the above linear aliphatic polyester are not particularly limited, but polyethylene adipate, polypropylene adipate, polybutylene adipate obtained by condensation polymerization of a polyhydric alcohol and an aliphatic dicarboxylic acid. And polyhexyl adipate, polybutylene succinate, polybutylene succinate adipate, and polycaprolactone obtained by ring-opening polymerization of caprolactone. One or more of these are suitably used.

Specific examples of the side chain aliphatic polyester are not particularly limited, but include polylactic acid, poly-3-hydroxybutyrate, poly-3-hydroxyvalerate, and poly-3-hydroxycaprate. Proate, poly-3-hydroxyheptanoate, poly-3-hydroxyoctanoate, poly-3-hydroxynanoate,
Poly-3-hydroxydecanoate, poly-3-hydroxydodecanoate, poly-3-methyl-5-hydroxyvalerate salate, poly-3,3'-dimethylpropylene adipate, and the like. Or 2
Species or more are preferably used, and among them, those having an alkyl group having 1 to 9 carbon atoms as a substituent are excellent in biodegradability and are more preferably used.

The aliphatic polyester of the component (a) means a linear aliphatic polyester or a side-chain aliphatic polyester synthesized using only a monomer containing no aromatic ring. There is no particular limitation.

The method for synthesizing the aliphatic polyester is not particularly limited. Examples thereof include condensation polymerization of a polyhydric alcohol and an aliphatic dicarboxylic acid, polymerization of a hydroxy group-containing carboxylic acid, and ring-opening polymerization of caprolactone. ,
Conventionally known methods such as production by microorganisms are mentioned, and any of these methods is suitably employed.

Specific examples of the above polyhydric alcohol are not particularly limited, but include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, and butanediol. , 4, hexanediol 1, 6 and the like. Specific examples of the aliphatic dicarboxylic acid include, but are not particularly limited to, adipic acid, succinic acid, and succinic anhydride.

In the first invention, the aliphatic polyester has a melt viscosity at 200 ° C. of 1000 to 1500.
It must be 00 poise. In addition, the melt viscosity mentioned here is a melt viscosity measured by the following method. [Measurement method of melt viscosity] Measuring device: Parallel disk type rheometer RMS (manufactured by Toyo Seiki Co., Ltd.) Measurement conditions: temperature 200 ° C., strain 20%, frequency 1 ra
d / sec

If the melt viscosity of the aliphatic polyester at 200 ° C. is less than 1000 poise, the mechanical strength of the resulting biodegradable polyester composition becomes insufficient. The fluidity during heating and melting of the water-soluble polyester composition is poor, and the molding workability is reduced.

Examples of the biodegradable organic fine particles of the component (b) include, but are not particularly limited to, starches, wood flour, cellulose, chitin, chitosan, collagen, keratin, fibroin and the like. One or more of these are preferably used, and among them, starches having a high biodegradation rate are more preferably used.

The particle size of the biodegradable organic fine particles is not particularly limited, but is preferably 50 μm or less. If the particle size of the biodegradable organic fine particles exceeds 50 μm, the mechanical strength of a molded article finally obtained from the biodegradable polyester composition may be insufficient.

Specific examples of the polyfunctional isocyanate compound (c) are not particularly limited, but include hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 3-isocyanatomethyl-3, 5,5-trimethylcyclohexyl isocyanate, dicyclohexylmethane-4,4 '
-Aliphatic diisocyanates such as diisocyanates,
2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, mixed isocyanate of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, diphenyl Aromatic diisocyanates such as methylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, isophorone diisocyanate, an adduct of trimethylolpropane and toluylene diisocyanate, and trimethylolpropane and 1, Triisocyanates such as adducts with 6-hexamethylene diisocyanate, etc., and one or more of these are preferably used. Among them, 1 of diisocyanates
Species or two or more species are more preferably used.

Among the above polyfunctional isocyanate compounds, when emphasis is placed on improving the flexibility of the biodegradable polyester composition, a diphenylmethane diisocyanate having a structure in which an electron-withdrawing aromatic ring is adjacent to an isocyanate group is used. Aromatic diisocyanates are more preferably used, and when emphasis is placed on improving the biodegradability of the biodegradable polyester composition, aliphatic diisocyanates such as hexamethylene diisocyanate having no aromatic ring in the molecular chain are preferred. Are more preferably used.

In the biodegradable polyester composition of the first invention, the aliphatic polyester 100
10 to 260 parts by weight, preferably 50 to 150 parts by weight, of the biodegradable organic fine particles of the component (b),
It is necessary that 0.5 to 10 parts by weight, preferably 3 to 6 parts by weight, of the polyfunctional isocyanate compound (c) is mixed and reacted.

When the amount of the biodegradable organic fine particles of the component (b) is less than 10 parts by weight per 100 parts by weight of the aliphatic polyester of the component (a), a sufficient cost-reducing effect cannot be obtained. If it exceeds 260 parts by weight, the flexibility of the molded article finally obtained from the biodegradable polyester composition becomes poor.

The aliphatic polyester 10 of the component (a)
If the amount of the polyfunctional isocyanate compound (c) is less than 0.5 part by weight relative to 0 part by weight, the effect of improving the flexibility by the chain extension of the aliphatic polyester cannot be sufficiently obtained, and conversely, 10 parts by weight. If it exceeds, an excess of isocyanate groups will cause cross-linking between molecules, causing an increase in the gel fraction, resulting in poor flexibility of the biodegradable polyester composition.

The invention according to claim 2 (hereinafter referred to as "the second invention")
That. ) The biodegradable polyester composition according to (1) contains the component (e) in an amount of 1 to 70 with respect to 100 parts by weight of the following component (d).
Parts by weight, and the total amount of the components (d) and (e) is 10
Component (f) is 10 to 260 parts by weight per 0 parts by weight,
(G) The components are mixed so as to be 0.5 to 25 parts by weight,
It is characterized by reacting. Component (d): a melt viscosity at 200 ° C. of 1000 to 1
Aliphatic polyester having 50,000 poise (e) component: aliphatic polyester having a number average molecular weight of 500 to 5,000 (f) component: biodegradable organic fine particles (g) component: polyfunctional isocyanate compound

The second invention is obtained by using a combination of a high molecular weight component (d) defined by the above range of melt viscosity and a low molecular weight component (e) defined by the number average molecular weight of the above range. It imparts even more excellent flexibility to the resulting biodegradable resin composition.

Examples of the aliphatic polyester of the component (d) include the same as the component (a) of the first invention.

The aliphatic polyester of the component (e) is the same as the component (d) except that the number average molecular weight is from 500 to 5,000. In addition, the number average molecular weight mentioned here is a number average molecular weight measured by the following method. [Method of Measuring Number Average Molecular Weight] Measuring device: Showa Denko column “shodex K-8”
GPC measurement by "02, K-803, K-804" Measurement conditions: mobile phase chloroform, flow rate 1 ml / min

When the number average molecular weight of the aliphatic polyester as the component (e) is less than 500, the mechanical strength of the resulting biodegradable resin composition becomes insufficient, and
If it exceeds 0, the elastic modulus of the obtained biodegradable resin composition will be high, and the flexibility of the finally obtained molded article will be reduced.

Further, it is preferable to use an oligomer of caprolactone as the component (e). The oligomer of caprolactone means polycaprolactone having a number average molecular weight of 500 to 5,000 obtained by ring-opening polymerization of caprolactone. By using an oligomer of caprolactone as the component (e), a biodegradable resin composition having both low elastic modulus and high flexibility can be obtained.

The biodegradable organic fine particles of the component (f) are the same as the component (b) of the first invention, and the polyfunctional isocyanate compound of the component (g) is a polyfunctional isocyanate compound of the first invention. The same as the component (c) can be used.

In the biodegradable polyester composition of the second invention, (e) is added to 100 parts by weight of the component (d).
The amount of the component is 1 to 70 parts by weight, and the total amount of the component (d) and the component (e) is 100 parts by weight, and the component (f) is 10 to 26 parts by weight.
It is necessary to mix and react 0 parts by weight, more preferably 3 to 15 parts by weight, and the component (g) to 0.5 to 25 parts by weight, more preferably 3 to 15 parts by weight. .

In the biodegradable resin composition according to the second invention, when the content of the component (e) is less than 1 part by weight per 100 parts by weight of the component (d), the elastic modulus of the resulting biodegradable resin composition is obtained. And the flexibility of the finally obtained molded article is lowered. On the other hand, when it exceeds 70 parts by weight, the residual amount of the component (e) which is not chain-extended increases, and the finally obtained molded article becomes Does not sufficiently improve, and the component (e) tends to bleed out on the surface of the molded product, making it difficult to obtain a good molded product.

If the amount of the biodegradable organic fine particles of the component (f) is less than 10 parts by weight based on 100 parts by weight of the total amount of the aliphatic polyesters of the components (d) and (e), it is sufficient. If the cost reduction effect cannot be obtained, and if it exceeds 260 parts by weight, the flexibility of the molded article finally obtained from the biodegradable polyester composition becomes poor.

If the amount of the polyfunctional isocyanate compound (g) is less than 0.5 part by weight based on 100 parts by weight of the total amount of the aliphatic polyesters (d) and (e), If the effect of improving the flexibility by chain extension cannot be sufficiently obtained, and if the amount exceeds 25 parts by weight, an excess of isocyanate groups causes cross-linking between molecules to increase the gel fraction, and the biodegradable polyester composition Is less flexible. In addition, as the amount of the polyfunctional isocyanate compound of the component (g) increases, the chain extension reaction of the aliphatic polyester is promoted and the molecular weight increases. Therefore, when the component (g) is used in an amount of 10 parts by weight or more, the fatty acid of the component (d) It is preferable to use an aromatic polyester having a melt viscosity of 100,000 or less.

The method for producing the biodegradable polyester composition according to the first and second aspects of the present invention is not particularly limited, and a predetermined amount of each of the aliphatic polyester, the biodegradable organic fine particles, and the polyfunctional isocyanate compound is extruded by uniaxial extrusion. Machine, twin screw extruder, Banbury mixer, kneading roll, Brabender,
Using a known mixing device such as a plastograph and a kneader, at a temperature of about 100 to 300 ° C. for about 3 to 15 minutes,
What is necessary is just to mix by a conventional method.

In the above production, the polyfunctional isocyanate compound (c) component or (g) component is prepared by previously mixing (a) component and (b) component or (d) component, or (e) component and (f) component. And may be added at the same time.

Further, in the biodegradable polyester compositions according to the first and second aspects of the present invention, by using starch as the biodegradable organic fine particles, more excellent biodegradability and flexibility can be obtained. Can be done.

Specific examples of the above-mentioned starches are not particularly limited, but may be corn, wheat, potato,
Raw starch obtained from rice, tapioca, sweet potato, etc., physically modified starch such as α-starch, oxidized starch, esterified starch,
Chemically modified starches such as etherified starch and cross-linked starch, and enzyme-modified starches such as dextrin and amylose are preferred, and one or more of these are preferably used. Further, the shape of the starch is not particularly limited, and may be tuber-like or granular.

The above-mentioned starch is treated at 80 ° C. to prevent hydrolysis when mixed with the aliphatic polyester.
It is preferable to use a pre-dried one for about 2 hours.

In the biodegradable polyester composition according to the second invention, as the amount of the starch added to 100 parts by weight of the aliphatic polyester increases in the range of 10 to 260 parts by weight, the obtained biodegradable polyester composition The rate of biodegradation of the material increases.

To the biodegradable polyester compositions according to the first and second inventions, various additives such as extenders, coloring agents, reinforcing agents, waxes and the like may be added as needed as long as the objects of the present invention are not hindered. One or more of the agents may be contained.

Specific examples of the extender include, but are not particularly limited to, talc, calcium carbonate, magnesium carbonate, barium carbonate, magnesium hydroxide, aluminum hydroxide, magnesium oxide, aluminum oxide, diatomaceous earth, and feldspar powder. , Mica, clay, silica, alumina, glass powder, inorganic powder such as stainless steel, aluminum, copper, magnetic iron and wood powder, cellulose, chitin, chitosan,
Organic powders such as collagen, keratin, fibroin and the like can be mentioned, and one or more of these are suitably used.

The biodegradable polyester compositions according to the first and second inventions can be used in an unstretched state after molding, or in a state after post-processing such as uniaxial stretching or biaxial stretching. Of course, it can also be used.

[0048]

The biodegradable polyester composition according to the first invention is an aliphatic polyester 100 having a specific melt viscosity.
With respect to parts by weight, a specific amount of biodegradable organic fine particles is mixed, and the aliphatic polyester is chain-extended by a specific amount of a polyfunctional isocyanate compound, so that excellent flexibility and biodegradability are obtained. And relatively inexpensive.

The biodegradable resin composition according to the second invention comprises a specific amount of an aliphatic polyester having a specific number average molecular weight mixed with a specific amount of an aliphatic polyester having a specific melt viscosity, and The specific amount of the polyfunctional isocyanate compound is mixed with respect to the total amount of the aliphatic polyester, and the aliphatic polyester is chain-extended and / or co-chain-extended, so that it exhibits excellent flexibility and biodegradability. I do.

Further, in the biodegradable resin composition according to the second aspect of the present invention, by using an oligomer of caprolactone as the aliphatic polyester having a specific number average molecular weight, more excellent flexibility and biodegradability are exhibited.

Further, by using starch as the biodegradable organic fine particles, more excellent biodegradability and excellent flexibility are exhibited.

[0052]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the examples, “parts” means “parts by weight”, “melt viscosity” means “melt viscosity at 200 ° C.”, and “molecular weight” means “number average molecular weight”.

Example 1 (1) Production of Biodegradable Polyester Composition In a Laboplastomill (manufactured by Toyo Seiki Co., Ltd.), as a component (a), polycaprolactone having a melt viscosity of 5000 poise (trade name “Placcel”) H7 "(manufactured by Daicel Chemical Industries, Ltd.) (100 parts) and 50 parts of corn starch starch (average particle size: 30 μm) as the component (b) were added and mixed at 180 ° C. for 4 minutes. 6 parts of diphenylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added and mixed at 180 ° C. for further 10 minutes to obtain a biodegradable polyester composition.

(2) Preparation of Molded Body Using a hydraulic press (manufactured by Toyo Seiki Co., Ltd.), the biodegradable polyester composition obtained above was molded into a sheet having a thickness of 0.4 mm, and an unstretched sheet was formed. A shaped body was obtained.

(3) Evaluation The performance (elongation, biodegradation) of the obtained molded article was evaluated by the following method. The results were as shown in Table 1. The evaluation was performed at 23 ° C-65 unless otherwise specified.
% RH in a constant temperature and humidity room.

Elongation A sheet sample (0.4 mm thick) was punched out with a No. 1 dumbbell to prepare a sample for measurement. Then, Tensilon (O
Using a tensile speed of 200 mm /
The elongation (%) was obtained by performing a tensile test of the obtained sample in minutes.

The degree of biodegradation of the sheet-shaped molded product (0.
4 mm thick) was cooled to below the glass transition temperature of the molded article by pouring it into liquid nitrogen, and then pulverized together with several pieces of dry ice using a personal mill SCM-40A pulverizer (manufactured by SIBATA). A powder for measurement of 0.8 mm was prepared.

In accordance with JIS K-6950 "Test method for aerobic biodegradation using plastic-activated sludge", a coulometer OM3001A type (manufactured by Okura Electric Co., Ltd.) was used as a biodegradability evaluation apparatus, and activated sludge A was used as activated sludge. hand,
A biodegradation test of the obtained powder was performed, and 28
The degree of biodegradation (%) after one day was determined. DB = [(SB) / ThOD] × 100 DB: Degradation degree (%) of plastic or control substance after 28 days S: BOD value of culture medium for biological test or control substance after 28 days (mg) B) BOD value (mg) of culture medium for biological blank test ThOD: Calculated value of oxygen consumption required for complete oxidation of plastic or control substance (theoretical oxygen demand,
mg)

Example 2 In the production of a biodegradable polyester composition, corn starch (average particle size 3
Example 1 except that the added amount was 0 part).
In the same manner as in the above, a biodegradable polyester composition was obtained.

Example 3 In the production of a biodegradable polyester composition, the component (a) had a melt viscosity of 1000
0 poise polybutylene succinate adipate (trade name "Bionole # 3010", manufactured by Showa Kogyo KK)
A biodegradable polyester composition was obtained in the same manner as in Example 1 except that 100 parts was used.

Example 4 In the production of a biodegradable polyester composition, corn starch (average particle size of 3) was used.
Example 3 except that the added amount was 0 part).
In the same manner as in the above, a biodegradable polyester composition was obtained.

Comparative Example 1 In the production of a biodegradable polyester composition, corn starch (average particle size 3
Biodegradable polyester composition in the same manner as in Example 1 except that the addition amount of 0 μm) was 100 parts and the polyfunctional isocyanate compound (4,4′-diphenylmethane diisocyanate) as the component (c) was not added. I got

Comparative Example 2 In the production of a biodegradable polyester composition, corn starch (average particle size of 3) was used.
Biodegradable polyester composition in the same manner as in Example 3 except that the addition amount of 0 μm) was 100 parts, and the polyfunctional isocyanate compound (4,4′-diphenylmethane diisocyanate) as the component (c) was not added. I got

Using the five types of biodegradable polyester compositions obtained in Examples 2 to 4 and Comparative Examples 1 and 2,
5 unstretched sheet-like molded articles (0.4
mm thickness). Next, the performance of the obtained five types of molded bodies was evaluated in the same manner as in Example 1. The results were as shown in Table 1.

[0065]

[Table 1]

Example 5 (1) Production of Biodegradable Polyester Composition Polycaprolactone having a melt viscosity of 5000 poise (trade name “Placcel”) was used as a component (d) in Labo Plastomill (manufactured by Toyo Seiki Co., Ltd.). H7 "(manufactured by Daicel Chemical Industries, Ltd.) (100 parts) and 60 parts of corn starch starch (average particle size: 30 μm) as the component (f) were added and mixed at 180 ° C. for 4 minutes.
After adding 20 parts by weight of polycaprolactone, which is 0 poise, and mixing at 180 ° C. for 2 minutes, 6 parts of 4,4′-diphenylmethane diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) is added as a component (g). And further mixed for 14 minutes to obtain a biodegradable polyester composition.

Example 6 The procedure of Example 5 was repeated, except that 100 parts of polybutylene succinate having a melt viscosity of 6,400 poise was used as the component (d) in the production of the biodegradable resin composition. Thus, a biodegradable resin composition was obtained.

Example 7 The procedure of Example 5 was repeated, except that 100 parts of polybutylene succinate adipate having a melt viscosity of 10,000 poise was used as the component (d) in the production of the biodegradable resin composition. A biodegradable resin composition was obtained.

Example 8 A biodegradable resin composition was prepared in the same manner as in Example 5 except that the amount of the corn starch as the component (f) was changed to 120 parts in the production of the biodegradable resin composition. Obtained.

Example 9 A biodegradable resin composition was prepared in the same manner as in Example 6, except that the amount of the corn starch as the component (f) was changed to 120 parts in the production of the biodegradable resin composition. Obtained.

Example 10 A biodegradable resin composition was produced in the same manner as in Example 5 except that the amount of the corn starch as the component (f) was changed to 240 parts in the production of the biodegradable resin composition. Obtained.

Example 11 A biodegradable resin composition was prepared in the same manner as in Example 6 except that the amount of the corn starch as the component (f) was changed to 240 parts in the production of the biodegradable resin composition. Obtained.

Example 12 In the production of the biodegradable resin composition, the amount of the polycaprolactone having a molecular weight of 2,000 as the component (e) was set to 11 parts, and the amount of the corn starch as the component (f) was changed to 120. And a biodegradable resin composition was obtained in the same manner as in Example 5 except that the amount of the component (g) 4,4′-diphenylmethane diisocyanate was 2.04 parts.

Example 13 In the production of a biodegradable resin composition, the amount of the polycaprolactone having a molecular weight of 2,000 as the component (e) was set to 67 parts, and the amount of the corn starch as the component (f) was set to 120. And a biodegradable resin composition was obtained in the same manner as in Example 5, except that the amount of component (g) 4,4′-diphenylmethane diisocyanate was 6.96 parts.

Example 14 In the production of a biodegradable resin composition, 100 parts of polycaprolactone having a melt viscosity of 100,000 poise as the component (d) and 20 parts of polycaprolactone (molecular weight 2000) as the component (e) were used. A biodegradable resin composition was obtained in the same manner as in Example 5, except that the amount of 4,4′-diphenylmethane diisocyanate, which was the component (g), was changed to 2.4 parts.

Comparative Example 3 In the production of a biodegradable resin composition, 100 parts of polycaprolactone having a melt viscosity of 5000 poise as a component (d) was added without adding the components (e) and (g). A biodegradable resin composition was obtained in the same manner as in Example 8, except that 100 parts of corn starch was used as the component (f) and mixed at 180 ° C. for 5 minutes.

Comparative Example 4 In the production of the biodegradable resin composition, 100 parts of polybutylene succinate adipate having a melt viscosity of 10,000 poise as the component (d) and 100 parts of corn starch starch as the component (f) were used. Except that, a biodegradable resin composition was obtained in the same manner as in Comparative Example 3.

Comparative Example 5 A biodegradable resin composition was prepared in the same manner as in Comparative Example 3, except that the amount of the corn starch starch (f) was changed to 200 parts. Obtained.

(Comparative Example 6) A biodegradable resin composition was prepared in the same manner as in Comparative Example 4 except that the amount of the corn starch as the component (f) was changed to 200 parts. Obtained.

Comparative Example 7 A biodegradable resin composition was prepared in the same manner as in Example 8 except that the amount of the corn starch starch (f) was changed to 360 parts in the production of the biodegradable resin composition. Obtained.

Comparative Example 8 The procedure of Example 8 was repeated, except that the amount of the component (g) 4,4′-diphenylmethane diisocyanate was changed to 0.36 part in the production of the biodegradable resin composition. A biodegradable resin composition was obtained.

(Comparative Example 9) Biodegradation was carried out in the same manner as in Example 8, except that the amount of the component (g) 4,4'-diphenylmethane diisocyanate was changed to 36 parts in the production of the biodegradable resin composition. A resin composition was obtained. When a sheet-like molded body was prepared in the same manner as in Example 1, a large amount of air bubbles was contained, and a good molded body was not obtained.

Comparative Example 10 Example 8 was repeated except that the component (g) 4,4′-diphenylmethane diisocyanate was not used in the production of the biodegradable resin composition.
In the same manner as in the above, a biodegradable resin composition was obtained. When a sheet-like molded product was prepared in the same manner as in Example 1, the product was sticky and a good molded product was not obtained.

Comparative Example 11 A biodegradable resin composition was produced in the same manner as in Example 8 except that 100 parts of polycaprolactone having a melt viscosity of 200000 poise was used as the component (d). A resin composition was obtained.
Using the obtained biodegradable resin composition, an attempt was made to produce a sheet-like molded body having a thickness of 0.4 mm in the same manner as in Example 5, but the flowability of the biodegradable resin composition was poor and the thickness was uniform. Could not be obtained.

Using the nine types of biodegradable resin compositions obtained in Examples 5 to 14, ten types of unstretched sheet-like molded articles (0.4 mm thick) were produced in the same manner as in Example 1. .
Next, the performance of the obtained 10 types of molded articles was evaluated in the same manner as in Example 1. The results were as shown in Table 2.

[0086]

[Table 2]

Using the nine types of biodegradable resin compositions obtained in Comparative Examples 3 to 11, an attempt was made to produce an unstretched sheet-like molded article (0.4 mm thick) in the same manner as in Example 1. Was. Good molded articles were not obtained from the compositions of Comparative Examples 9 and 10. The composition of Comparative Example 11 could not be formed into a uniform thickness. Next, the performance of the obtained molded body was evaluated in the same manner as in Example 1. The results were as shown in Table 3.

[0088]

[Table 3]

[0089]

As described above, the biodegradable polyester composition according to the present invention has excellent flexibility and biodegradability and is relatively inexpensive.
It is suitably used for a wide range of uses such as fibers.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08G 18/40 NDW A23L 1/04

Claims (4)

[Claims] 1. A method according to claim 1, wherein 100 parts by weight of the following component (a) is
10-260 parts by weight of component (b) and 0.5-component (c)
A biodegradable resin composition obtained by mixing and reacting 10 parts by weight. Component (a): a melt viscosity at 200 ° C. of 1000 to 1
Aliphatic polyester having 50,000 poise (b) component: biodegradable organic fine particles (c) component: polyfunctional isocyanate compound 2. With respect to 100 parts by weight of the following component (d),
The component (e) is 1 to 70 parts by weight, and the component (f) is 1 to 100 parts by weight in total of the component (d) and the component (e).
A biodegradable resin composition obtained by mixing and reacting 0 to 260 parts by weight and the component (g) to 0.5 to 25 parts by weight. Component (d): a melt viscosity at 200 ° C. of 1000 to 1
Aliphatic polyester having 50,000 poise (e) component: aliphatic polyester having a number average molecular weight of 500 to 5,000 (f) component: biodegradable organic fine particles (g) component: polyfunctional isocyanate compound 3. Component (e) having a number average molecular weight of 500 to 5
3. The biodegradable resin composition according to claim 2, wherein the aliphatic polyester (000) is an oligomer of caprolactone. 4. The biodegradable polyester composition according to claim 1, wherein the biodegradable organic fine particles are starches.