JPS5910377B2 - Method for manufacturing microporous structure - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a microporous structure.

More specifically, the present invention relates to a method for producing a microporous structure having excellent moisture permeability, flexibility, appearance, mechanical properties, etc. from an elastomer having a specific hydrophilic group and a specific organic polymer. . In recent years, there has been an increase in the production of so-called leather substitutes in order to obtain large quantities of natural leather with excellent properties and uniform quality.

When this type of microporous structure is intended for use on the human body, it is particularly important that it does not get stuffy when worn with shoes, clothes, etc. For this reason, various methods for manufacturing microporous structures having water vapor permeability have been proposed. One such proposal is to prepare a dispersion by adding water to an organic solvent solution or suspension of a polyurethane elastomer containing only polyoxyethylene groups as hydrophilic groups, and to impregnate or coat a substrate with the dispersion. There is a method of obtaining a microporous structure by first selectively evaporating the organic solvent and drying it (Japanese Patent Publication No. 48-4380 (Patent No. 70)).
4073)).

In addition, a dispersion liquid is prepared by adding water to an organic solvent solution or suspension of a polyurethane elastomer containing only ionic hydrophilic groups as hydrophilic groups, and the dispersion liquid is impregnated or coated on a base material. There is a method of selectively evaporating and further drying to obtain a microporous structure (JP-A-49-11959, JP-A-49-88958).

According to these methods, better microporous structures can be obtained than conventional wet or dry methods. However, even with these methods, it is difficult to obtain microporous structures with sufficiently low apparent densities, and as a result, moisture permeability, flexibility, and appearance are still not fully satisfactory. There also remained room for improvement in the mechanical properties of microporous structures. The present inventors have arrived at the present invention as a result of intensive research aimed at improving the above method and developing a method for manufacturing microporous structures with even better moisture permeability, flexibility, appearance, and mechanical properties. It is.

That is, the present invention provides at least one organic solvent selected from the group consisting of (a) an organic solvent having a boiling point of 120°C or less and a water solubility of 1 to 509 (per 1009 organic solvent) at 25°C; and a polyoxyethylene group. The organic solvent (
(a) an elastomer soluble in the organic solvent (a); and (c) an organic polymer that is insoluble or swellable in the organic solvent (a) and is a powder with a diameter of 50 μm or less, and the weight ratio of the elastomer to the organic polymer is 70: 30-15:8
Add and mix water in an amount of 10 to 95% by weight of the critical water addition amount defined in the text to the slurry in the range of 5 to form a water-containing slurry, and coat and/or impregnate a substrate with the water-containing slurry. After that, the organic solvent (a
) is selectively evaporated to gel the elastomer and organic polymer, and then dried.

The organic solvent (a) used in the present invention has a boiling point of 12
0°C or lower, and the water solubility at 25°C is 1 to
50 g (per 1009 organic solvent), and must also have the property of dissolving the elastomer described below.

As mentioned above, since the method of the present invention is a dry method, that is, evaporation drying of an organic solvent to coagulate and form fine pores in the elastomer and organic polymer, it is appropriate to use a material with a relatively low boiling point, which is much lower than the boiling point of water. When an organic solvent with a high boiling point is used, rapid solidification and formation of micropores becomes difficult. Also, those having too low a boiling point are unfavorable in terms of operation. Therefore, the temperature of the organic solvent used in the present invention is 120°C or lower, preferably 100°C or lower and 50°C or higher. Also,
In order to form a stable water-containing slurry, the solvent must be able to dissolve a specific amount of water, and the solubility of water in the solvent 1009 at 25°C is 1 to 509, preferably 5 to 30.
Must be 9. Examples of solvents that satisfy these conditions include methyl ethyl ketone (MEK), methyl-n-propyl ketone, and methyl isobutyl ketone (
MIBK), diethyl ketone (DEK-), methyl formate, ethyl formate, propyl formate, methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate, and the like.

Furthermore, by mixing acetone, tetrahydrofuran (THF), dioxane, etc., which have a high water solubility in an organic solvent, and benzene, toluene, n-hexane, 1,2-dichloroethane, etc., which have a low solubility in water or the above solvent, It is also possible to use a mixed solvent in which the solubility of water in the mixed solvent is adjusted to 1 to 509 (per 1009 of the organic solvent). Particularly preferred solvents from the viewpoint of ease of recovery and appropriate solubility of the elastomer and water are MEKl ethyl acetate and a mixed solvent of THF and ethyl acetate. The elastomer in the present invention contains at least one type of hydrophilic group in its molecular chain in an amount of 10 to 98% by weight, preferably 15 to 50% of the amount of critical phase inversion hydrophilic groups defined below.
Weight% containing polyurethane elastomer, polyester elastomer, polyester ether elastomer,
Examples include polycarbonate elastomer.

Of course, those containing two or more types of salt type groups in the molecular chain can also be used, but if the cation type and anion type are used together, the hydrophilic group will be lost due to chemical reaction, so either the cation or the anion type will be used. Two or more of them should be used together or in combination with a polyoxyethylene group. When the amount of hydrophilic groups contained in the molecular chain of the elastomer is less than 10% by weight of the amount of critical phase inversion hydrophilic groups, the amount of water necessary to obtain a microporous structure having continuous micropores in the slurry is , it cannot be stably dispersed, and the structure targeted by the present invention cannot be obtained. If the amount of hydrophilic groups exceeds 98% by weight of the amount of critical phase inversion hydrophilic groups, the hydrophilicity of the polymer is too large, so the porous structure is formed once by water containing residual solvent in the selective evaporation step or drying step described later. This is not preferable because it tends to fuse. The critical phase inversion hydrophilic group amount in the present invention means that when water is added to an organic solvent solution of an elastomer,
It becomes a W/O emulsion, but even if you add more water, it becomes an O/O emulsion.
It refers to the maximum amount (% by weight) of hydrophilic groups contained in an elastomer that cannot form a W-type emulsion. The "critical phase inversion hydrophilic group amount" can be determined from the relationship between the amount of water and the viscosity when water is added to the elastomer solution, as shown in FIG. That is, when this elastomer solution has a hydrophilic group content that can become an O/W type aqueous dispersion (aqueous latex), there exists a mode represented by the curves A, b, and c, and the maximum point of the curve (Ma, Mb, Mc) is W/
It shows the phase change point from type 0 to O/W type. Here, c
-+b→a contains more hydrophilic groups,
The more hydrophilic groups the elastomer solution contains, the smaller the viscosity increase and the smaller the viscosity at the phase inversion point. If the amount of hydrophilic groups is decreased, the W/0 type emulsion will eventually fail to become an O/W type emulsion, as shown by d in Figure 1, and the viscosity will continue to increase, and the system will eventually become Either gelation occurs or water becomes liberated from the system.

When the amount of hydrophilic groups is reduced from a-+b-+c to d in this way, the elastomer solution has a critical amount of hydrophilic groups such as d, which prevents the elastomer solution from changing from a W/O type to an O/W type emulsion. The solution is called "a solution of an elastomer having a critical phase inversion hydrophilic group content." The amount of critical phase inversion hydrophilic groups varies depending on the type of hydrophilic groups, the composition of the elastomer, the solvent of the elastomer solution, the concentration, the temperature, the water addition rate, and the stirring rate, but in the present invention, it is measured under the following conditions.

First, an elastomer solution containing an arbitrary amount of hydrophilic groups was added to the
009 and heated to 3000r. while keeping the temperature at 30℃. p
．． m. While stirring with a homo mixer (manufactured by Tokushu Kika Kogyo (4)), water at 30°C was added at a rate of 10ml/11.

At this time, record the relationship between the amount of water and the viscosity, and create a graph as shown in Figure 1.

This operation was carried out on various solutions of the same type of elastomer with the same concentration but only the amount of hydrophilic groups was changed, and it was found that the elastomer gelled or water was liberated from the system.
An elastomer having the maximum amount of hydrophilic groups among the elastomers having the amount of hydrophilic groups that cannot be converted into an O/W type emulsion (aqueous latex) from a /0 type is determined. The amount of hydrophilic groups is defined as the amount of critical phase inversion hydrophilic groups of the elastomer at that concentration. Among the elastomers of the present invention containing hydrophilic groups as described above, polyurethane elastomers include, for example,
A method in which a prepolymer having substantially terminal isocyanate groups is prepared from a long-chain diol and an excess molar amount of diisocyanate, and then a chain extension reaction of the prepolymer is carried out in the solvent, the diisocyanate and long-chain diol serving as raw materials for polyurethane. It can be easily produced by a method using a compound capable of forming a hydrophilic group as at least one of a chain extender or an end capping agent.

Examples of hydrophobic diisocyanate compounds include 4,4
'-Diphenylmethane diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, 2,4-tolylene diisocyanate, 2,6
-Tolylene diisocyanate, 1,5-naphthalene diisocyanate, m-phenylene diisocyanate, P-
Examples include phenylene diisocyanate.

Examples of the group capable of becoming hydrophilic or the diisocyanate compound having a hydrophilic group include bischloromethyldiphenylmethane diisocyanate, 2,4-diisocyanate benzyl chloride, and 2,6-diisocyanate benzyl chloride. The group that can become hydrophilic, that is, the halogen atom bonded to these diisocyanate compounds, is a basic tertiary amino group that can be quaternized by reacting with a halogen atom such as trimelamine, triethylamine, tributylamine, pyridine, and triethanolamine. At least one of the compounds having
It can be quaternized with a species and become a hydrophilic group as a quaternary ammonium salt. Hydrophilization may be carried out at the raw material stage, during the production of the elastomer, or after the formation of the elastomer. Examples of hydrophobic long-chain diols include polyethylene adipate, polyethylene propylene adipate, polyethylene butylene adipate, polydiethylene adipate, polybutylene adipate, polyethylene succinate, and polybutylene succinate, each having a molecular weight of 500 to 4,000 and whose terminal group is substantially a hydroxyl group. nate, polyethylene sebacate, polybutylene sebacate, polytetramethylene teterglyceride. Coal, poly-ε-caprolactone diol, etc. can be mentioned. Groups that can become hydrophilic groups or long-chain diols that have hydrophilic groups include, for example, polyesters that have an aliphatically bonded reactive halogen atom with a molecular weight of 500 to 4,000 and whose terminal ends are essentially hydroxyl groups, and which have tertiary amino groups. Examples include polyester, polyester having a tertiary amine salt, and polyester having a quaternary amine salt. These groups that can become hydrophilic groups, ie, tertiary amino groups, become salts with organic acids, inorganic acids, compounds having a reactive halogen atom, and esters of corresponding strong acids, and become hydrophilic groups. As the hydrophobic chain extender, it is preferable to mainly use aliphatic low-molecular-weight diols such as ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol; however, these aliphatic diols It is also possible to carry out chain extension to a certain extent with a difunctional amino compound and then carry out the remaining chain extension with a difunctional amino compound.

These difunctional amino compounds include ethylenediamine, 1,2-propylenediamine, trimethylenediamine, tetramethylenediamine, hexamethylenediamine, decamethylenediamine, m-xylylenediamine, pentidine, 4,4'-diaminodiphenyl methane, m-
phenylenediamine, hydrazine, methylhydrazine,
Examples include aminoacetic acid hydrazide and ω-aminopropionic acid hydrazide. Examples of chain blocking agents that can be hydrophilic include (1) compounds having two hydroxy groups and a carboxylic acid; dioxymaleic acid, dioxyfumaric acid, tartaric acid, 2,6-dioxybenzoic acid, protocatechuic acid; , α-resorcylic acid, β-resorcylic acid, hydroquinone-2,5-dicarboxylic acid, 4,6-dihydroxyisophthalic acid, 2,8-dihydroxynaphthoic acid-(3)(2) Two hydroxyl groups and a sulfone Compounds with acids; 1,7-dihydroxy-naphthalene sulfonic acid (3), 1,8-dihydroxynaphthalene disulfonic acid (2,4), chromotropic acid, pentaerythritol bis-benzosulfonate, glycerin-monomethane Sulfonates, (3) phosphines; diethyl-β-hydroxyethylphosphine, methyl-bis-β-hydroxyethylphosphine, tris-β-hydroxymethyl-phosphine, bis-(α-hydroxy-isopropyl)-phosphinic acid (2) Sulfide, dihydroxy dihexyl sulfide, diaminodipropanol Pilsulfide, bis-(β-hydroxy-β-phenyl-ethyl)-sulfide, 5-methyl-thioblycerin,
Thiodiglycolic acid, sulfide mono-β-dipropionic acid, sulfide mono-α-dibutyric acid, (5) Tertiary amino compound N-methyldiethanolamine, N-butyldiethanolamine, N-oleyldiethanolamine, N-cyclohexyldiethanolamine, N-methyl Examples include diisoprobanolamine and N,N-dihydroxyethylaniline.

For the compounds (1), (2) and (3), organic and inorganic bases such as sodium hydroxide, potassium hydroxide, potassium carbonate, sodium bicarbonate, ammonia, primary, Secondary and tertiary amines are suitable.

For compounds (3), (4) and (5), an alkylating agent is used as a salt forming agent.

For example, methyl chloride, methyl bromide, butyl bromide, dimethyl sulfate, diethyl sulfate, benzyl chloride, p-nitrobenzyl chloride, benzyl bromide, ethylene chlorohydrin, ethylene bromohydrin, epichlorohydrin, ethylene oxide, propylene oxide, bromobutane. Alternatively, p-toluenesulfonic acid ester may be mentioned. Further, the chain extender may be a compound having a sulfonic acid, a boshoodrin atom, or a sulfide sulfur atom.

Examples of the terminal capping agent include polyoxyethylene glycol monoalkyl ester.

The hydrophilic polyoxyethylene group usually has a molecular weight of 200 to 4.
000, and the polyoxyethylene group is a polyester having an 0H group at the terminal obtained from the diisocyanate compound, a long chain diol, a chain extender and polyoxyethylene glycol, or from a dicarboxylic acid and polyoxyethylene glycol. is introduced into the polyurethane elastomer by reacting.

The hydrophilic group content or hydrophilic strength of a polyurethane elastomer containing such hydrophilic groups can be expressed as the percentage (weight) of the hydrophilic groups contained in the polyurethane elastomer.

In the case of an elastomer having a small content of hydrophilic groups, sufficient water cannot be stably dispersed in the elastomer solution to obtain a microporous structure. If the content of hydrophilic groups is too large, the elastomer solution will change from W/0 type to O/
Since this may result in a W-type emulsion (aqueous latex), the microporous structure aimed at in the present invention cannot be obtained. The amount of hydrophilic groups required to obtain the microporous structure targeted by the present invention varies depending on the composition of the elastomer, the type of hydrophilic groups, the concentration of the elastomer, etc.;
In a 20% by weight solution of polyurethane-methyl ethyl ketone, the telether has a molecular weight of 1,000 to 5,000, preferably 1,500 to 3,000.

The polyester elastomer of the present invention has an optimum range for satisfying desirable properties as a leather substitute material, such as heat resistance, solvent resistance, flexibility, etc., but the composition and proportion of the crystalline polyester segment must be set to an appropriate ratio. You can reach your goal by. As a method for introducing hydrophilic groups into the polyester elastomer of the present invention, an appropriate amount of the compound listed above as a chain extender that can become a hydrophilic group in the polyurethane is mixed into the dihydric alcohol that is a component of the polyester elastomer. This can be achieved by

The method for producing the polyester elastomer used in the present invention is, for example, to previously produce an oligopolyester consisting of terephthalic acid and ethylene glycol as a crystalline polyester segment, and then to mix polytetramethylene glycol therein and perform a melt reaction. It can be manufactured by

Another method is to mix a dibasic acid such as terephthalic acid or adipic acid with ethylene glycol at an appropriate mixing ratio, perform a preliminary reaction at 150°C to 180°C using an esterification catalyst, and then perform a preliminary reaction under reduced pressure. 200~2 while removing water with
Although a method of completing the reaction at 70° C. can be used, the present invention is not limited to these production methods. The powdered organic polymer used in the present invention must be swellable or insoluble in the organic solvent. Preferably, a powdered organic polymer having a swelling degree of 35% or less in the organic solvent is used. The degree of swelling is defined as follows. That is, the test polymer had a thickness of 0.10±0.0211
! Film and pear test Suspended from above into an organic solvent 5C! ! LC is the value expressed as the degree of elongation under its own weight after 15 minutes of immersion in an organic solvent.
I! When L, it is expressed by the following formula. Swelling degree = (L-15
)/15×100 When using a powdered organic polymer with a swelling degree of over 35%,
During the selective evaporation of the organic solvent, which will be described later, the elastomer dissolved in the powdered organic polymer undergoes a large contraction, so that the object of the present invention is to obtain an improved microporous structure having a low apparent density. I can't.

The powdered organic polymer of the present invention has a particle size of 50μ or less,
Preferably 1 to 30 microns should be used.

If particles with a particle size exceeding 50 μm are used, the surface smoothness will be unfavorable and the strength of the product will also be reduced. The powdered organic polymer prevents the selective evaporation of the organic solvent mentioned later and the shrinkage and fusing of the dissolved elastomer that occurs during drying, and serves as a support for the elastomer. Preferably, the polymer has some degree of adhesion with the elastomer. Examples of such powder organic polymers include polyester, polyester polyether copolymer, polyamide, etc., as well as polyvinyl chloride, polyvinylidene chloride, polyacrylic ester copolymer, polymethacrylic ester copolymer, polystyrene, etc. , cellulose acetate, ethyl cellulose, butyl cellulose, etc. The polyester powder can be manufactured using the raw materials exemplified as the crystalline polyester segment of the polyester elastomer.

In this case as well, the polyester powder obtained must satisfy the above-mentioned solubility conditions in the solvent used. As is clear from Table 1, the mixing ratio of the elastomer and powdered organic polymer is elastomer: powdered organic polymer = 70:30 to 15 by weight.
:Should be in the range of 85.

If the mixing ratio is outside the above range, a microporous structure with low apparent density and excellent mechanical properties, which is the object of the present invention, cannot be obtained. In the present invention, the powder organic polymer molecules can also contain the same amount or less of the hydrophilic groups contained in the molecular structure of the elastomer used at the same time, and in this case, when a water-containing slurry is formed, This is preferable because it provides stable dispersion. The method of mixing the elastomer soluble in the organic solvent and the powdered organic polymer is (
1) Adding the powdered organic polymer before starting the elastomer polymerization reaction, (2) Adding the powdered organic polymer during the elastomer polymerization reaction, (3) Adding the powdered organic polymer into the elastomer organic solvent solution and stirring. Either method can be adopted. The organic solvent slurry of the elastomer and powdered organic polymer prepared in the present invention has a total polymer concentration of 10 to 40% by weight, preferably 15 to 30% by weight.
It is best to adjust it to % by weight.

If the concentration is less than 10% by weight, the viscosity of the water-containing slurry obtained from this slurry is low and the fluidity is high, making it difficult to coat a substrate, which is not preferable. If the total polymer concentration exceeds 40% by weight, it is not preferable because the viscosity is too high and a gel-like substance is likely to form, making impregnation and coating difficult. In the present invention, a water-containing slurry is formed by adding and mixing water to the slurry consisting of the elastomer and powdered organic polymer.

The added water is very stably retained in the slurry due to the synergistic effect of using an elastomer with a specific amount of hydrophilic groups and a solvent with limited water solubility. The appearance of this water-containing slurry is white and creamy, and it is clear that water is emulsified and dispersed by the specific elastomer. The amount of water added in the present invention is 10 to 95% by weight of the amount of critical water added.

If the amount of water added is less than the critical water amount of 1001), a structure with a high density and some transparency is obtained, making it difficult to obtain the desired continuous microporous structure. In addition, if the amount of water added exceeds 95% of the amount of critical water added, water close to the amount of critical water added will be added, and the resulting water-containing slurry will be unstable and will have a large tendency to liberate water. It does not become a water-containing slurry.

The "amount of critical water added" here refers to when water is added to a slurry of elastomers and organic polymers having hydrophilic groups of 98% by weight or less of the critical hydrophilic group amount, as shown in Figure 2.
As the amount of water increases, the viscosity of the system increases, but if the critical amount P is exceeded, the elastomer and organic polymer of the system will gel or water will be liberated from the system.

The amount of water at this critical point P is called the critical water addition amount, and slurry 1
It is expressed by the number 9 of water relative to 009. As a method for preparing such a water-containing slurry, 1) a method of adding water to the slurry in batches, 2) a method of continuously mixing the slurry and water, etc. are employed. In either method, since a solvent with limited water solubility is used in the present invention, there is an advantage that local coagulation and precipitation of the elastomer and organic polymer is less likely to occur when water is added. If necessary, known additives such as dyes, pigments, crosslinking agents, stabilizers, fillers, etc. can be added to the water-containing slurry to the extent that the dispersion system is not destroyed. The solid content concentration of the water-containing slurry is generally in the range of 5 to 30% by weight, preferably 8 to 20% by weight.

The process of forming a microporous structure using such a slurry includes 1) coating or impregnating a desired base material with a water-containing slurry, and 2) selectively removing a solvent from the water-containing slurry while preventing water evaporation. 3) drying the remaining solvent and water. As a base material,
Woven fabrics, non-woven fabrics or other similar materials can be used.

In addition, if a suitable support (e.g., glass plate, metal foil, plastic film, etc.) is used as a base material, and a water-containing slurry is coated on this and peeled off from the support after evaporation drying, a film-like material useful as the skin of synthetic leather can be obtained. Microporous structures can be obtained. Any known method can be used to coat and/or impregnate the substrate with the water-containing slurry.

For example, there are coating methods, dipping methods, etc. In the selective evaporation step, it is necessary to selectively evaporate the solvent while leaving as much water as possible.

"Selective evaporation" here means that the ratio of water to solvent increases with the time of the evaporation process. To carry out such selective evaporation, it is necessary to suppress water evaporation as much as possible, so the atmosphere is kept humid or the temperature of the evaporation process is set to 8.
It is desirable that the temperature be below 0°C and at least 10°C lower than the boiling point of the lowest boiling point solvent in the aqueous slurry.

At temperatures above 80°C, it becomes too close to the boiling point of water, making it difficult to suppress water evaporation and making it difficult to selectively evaporate the solvent.

When a considerable amount of water evaporates along with the evaporation of the solvent, the polymer does not coagulate into a porous structure, making it impossible to obtain a microporous structure with high water vapor permeability. Furthermore, if the temperature is 10°C lower than the boiling point of the solvent, the solvent evaporates too quickly, which tends to cause large pores that are visible to the naked eye in the layer applied to the base material, which may deteriorate the surface condition. . The time required for the selective evaporation step is at least the time required for the water-containing slurry to reach the gel point.

The gel point is the point at which the elastomer-organic polymer in the slurry solidifies as a result of evaporation of most of the solvent from the slurry layer applied to the substrate (the point at which the film formed by the elastomer-organic polymer separates from the substrate). The point is that the film can be peeled off while maintaining its shape. At the end of the selective evaporation process of the solvent, the structure is already in a fairly solidified state, although a small amount of solvent still remains in the structure.
The desired microporous structure can be obtained by drying without performing a coagulation bath treatment and removing the remaining solvent together with water.

The structure thus obtained has numerous interconnected micropores and has excellent water vapor permeability, high strength, flexibility, and excellent feel, as well as excellent thermal properties.

Since almost all of the solvent is evaporated in the selective evaporation step and the drying step, the solvent can be recovered easily and quickly, which is extremely advantageous in terms of operation. According to the method of the present invention, a microporous structure having the above characteristics can be produced quickly and economically, and the obtained microporous structure can be used in various forms.

For example, those obtained using woven fabrics, non-woven fabrics, or similar materials as substrates may be used as is or laminated onto other substrates, or in some cases may be produced in the form of a film made separately. A microporous structure can also be used as a skin. These structures can be widely used in the fields of shoe uppers, bags, clothing, etc. as leather substitutes. Next, the present invention will be explained in detail with reference to Examples.

All parts and percentages in the examples are by weight unless otherwise specified. In addition, the tensile strength and cutting elongation in the examples are JIS-K-6301, and the moisture permeability rate is JIS-K-6301.
549, 5% elongation stress was measured according to JIS-K-6301, and the softening point was measured according to ASTM-D-1525.

In the case of polyurethane, the intrinsic viscosity is a value measured by measuring the viscosity of a 0.2% by weight dimethylformamide solution at 30°C using an Ostwald viscometer. In the case of polyester elastomer, the value is the viscosity of a 1.2% by weight orthochlorophenol solution at 30°C measured using an Ostwald viscometer. The apparent density is a value calculated from the weight and thickness of a sample of 10CIL x 10CIIL. Production examples of elastomers and organic polymers used in the present invention [
P-1. Polyurethane P1] Molecular weight 1900 obtained by copolymerization of adipic acid, 1,4-butanediol and neopentyl glycol (molar ratio of 1,4-butanediol and neopentyl glycol is 8.5:1.5) 669.6 parts of polyester diol, 40 parts of polyoxyethylene glycol with a molecular weight of 1540
．． 0 parts, 239.3 parts of 4,4'-diphenylmethane diisocyanate were dissolved in 231 parts of tetrahydrofuran and reacted to obtain a prepolymer of terminal isocyanate.

Next, a solution of 51.1 parts of 1,4-butanediol dissolved in 950 parts of tetrahydrofuran was added to carry out a chain extension reaction, and when the reaction was completed, 28 parts of methyl ethyl ketone was added.
19 parts were added to obtain a 20% polyurethane solution.

[P-2 Polymerization of polyurethane P2] Polyester diol 668.3 used in P-1 above
Part, 4,4'-diphenylmethane diisocyanate 26
7.3 parts were dissolved in 234 parts of methyl ethyl ketone and reacted to obtain a prepolymer.

Next, 60.1 parts of 1,4-butanediol and 4.2 parts of N-methyldiethanolamine were added to 766 parts of methyl ethyl ketone.
A chain elongation reaction was carried out by adding a solution dissolved in 1 part of 20 (F6 polyurethane methyl ethyl ketone solution) to which 3.0 parts of acetic acid was finally mixed. [P-3. Polymerization of polyester elastomer P] Crystallinity 35% by weight of polyethylene terephthalate as a component, 60% by weight of copolyester of sebacic acid, terephthalic acid, and ethylene glycol (molar ratio of sebacic acid and terephthalic acid is 90:10) as an amorphous component, and polyethylene with a molecular weight of 1500. A copolymerized polyester elastomer containing 5% by weight of glycol was dissolved in methyl ethyl ketone to give 20% by weight.
A % concentration solution was prepared. [P-4. Polymerization of polyester elastomer P4] As a crystalline component, a copolymerized polyester of adipic acid, terephthalic acid, and 1,4-butanediol (the molar ratio of adipic acid and terephthalic acid is 30:70)
) 40% by weight, polyoxytetramethylene glycol (average molecular weight 2000) 56% by weight as an amorphous component, and polyoxyethylene glycol (average molecular weight 160)
A 20(f) solution was prepared by dissolving a copolymerized polyester elastomer consisting of 0) 4% by weight in methyl ethyl ketone in an autoclave.

[P-5. Production of Powdered Organic Polymer] A copolymerized polyester obtained from 70 mol% of terephthalic acid, 30 mol% of isophthalic acid, and ethylene glycol was ground at low temperature to produce granules having an average particle size of 20 μm.

The degree of swelling of this polymerized polyester in methyl ethyl ketone was 15%. Example 1 20% of the granular polyester of P-5 was added to the solution obtained in P-1 to correspond to 40% of the total polymer.
% concentration methyl ethyl ketone solution to form a stable dispersion.

To this dispersion, 35 parts of water was added to 100 parts of the dispersion while stirring with a homomixer to form a stable water-containing slurry. A nonwoven fabric sheet made of polyester fibers is immersed in this water-containing slurry and squeezed with a squeezing roll having a gap of 120% of the thickness of the nonwoven fabric, and then the surface of this nonwoven fabric is
? ! The water-containing slurry was coated with a thickness of 40° C.
30 minutes in an atmosphere of 70% relative humidity, then at a temperature of 60°C
, left in an atmosphere with a relative humidity of 60 (fl) for 20 minutes to gel, then heated at a temperature of 80°C for 10 minutes at a temperature of 110°C.
After drying at ℃ for 10 minutes, a leather-like structure was obtained. This structure has a microporous structure with excellent water vapor permeability,
It has a good texture and excellent durability, making it ideal as a leather substitute. (See Table 2). Example 2 A microporous structure was prepared using polymers P-2 and P-5 in the same manner as in Example 1 (see Table 2).

Example 3 A microporous structure was prepared using polymers P-3 and P-5 in the same manner as in Example 1 (see Table 2).

Example 4 A microporous structure was prepared using polymers P-4 and P-5 in the same manner as in Example 1 (see Table 2).

Comparative Example 1 i Porous molding was attempted in the same manner as in Example 1 without adding P-5 powder polymer to the P-1 polymer solution, but
It could not be porous and had an unfavorable texture (see Table 2).

Comparative Example 2 Polyester with a molecular weight of 1900 obtained by copolymerization of adipic acid, 1,4-butanediol and neopentyl glycol (molar ratio of 1,4-butanediol and neopentyl glycol is 8.5:1.5) 587.2 parts of diol, polyoxyethylene glycol 40 with a molecular weight of 1540
part, 4,4'-diphenylmethane diisocyanate 29
7.4 parts were dissolved in 231.2 parts of methyl ethyl ketone and reacted to obtain a prepolymer with terminal isocyanate.

Next, a solution of 75.4 parts of 1,4-butanediol dissolved in 435.5 parts of methyl ethyl ketone was added to carry out a chain extension reaction, and when the reaction was completed, 3333 parts of methyl ethyl ketone was added to make 20 (fl) of polyurethane. It was made into a dispersion liquid.

That is, the polyurethane is not soluble in methyl ethyl ketone and contains an insoluble portion. This polyurethane dispersion was subjected to porous molding in the same manner as in Example 1. The microporous structure thus obtained was superior to that of Comparative Example 1, but inferior to that of the invention (see Table 2). The polymer for microporous structures obtained by this method is a slurry obtained by simultaneously producing solvent-insoluble polymer particles and dissolved polymer in the polymerization step, and it is difficult to control the polymerization. There still remains the problem that variations in polymerization conditions cause variations in product quality, or giant particles appear on the product surface, causing defects in appearance. There is also the problem that it is small.

Example 5 Adding P to the polyurethane methyl ethyl ketone solution of P-1
-5 Dispersions containing different amounts of polyester powder were prepared, and porous molding was attempted using the same procedure as in Example 1.

The results are shown in Table 1.

Examples 6 to 10 The following 20% polyurethane solution was prepared using diphenylmethane diisocyanate as the organic diisocyanate, polyethylene adipate with a molecular weight of 1710 as the polyol, 1,4-butanediol as the chain extender, and methyl ethyl ketone as the solvent. Then, the polyester powder of P-5 was mixed in the same manner as in Example 1.
A leather-like structure was obtained in the same manner as above.

The results are summarized in Table 2. Among the above raw materials, tartaric acid and sodium isothionate are mixed with a chain extender and reacted, and bis-(β-hydroxyethyl) phosphate, thiodiethanol, and methyl-bis-hydroxyethylphosphine benzyl chloride are used to create polyethylene adipate. When doing this, it was used as a diol component mixed with ethylene glycol and reacted.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the amount of critical phase inversion hydrophilic groups, and FIG. 2 is an explanatory diagram of the amount of critical water added.

Claims (1)

[Scope of Claims] 1(a) An organic solvent having a boiling point of 120°C or less and a water solubility of 1 to 50g (per 100g of organic solvent) at 25°C, (b) ▲A mathematical formula, a chemical formula, a table, etc. There are ▼, ▲mathematical formulas, chemical formulas,
There are tables, etc. ▼, -S^■<, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼, ▲
There are mathematical formulas, chemical formulas, tables, etc. ▼ and at least one hydrophilic group selected from the group of polyoxyethylene groups,
an elastomer soluble in the organic solvent (a) containing 10 to 98% by weight of the amount of critical phase inversion hydrophilic groups defined herein; and (c) an elastomer that is insoluble or swellable in the organic solvent (a) and has a diameter of A slurry made of an organic polymer in the form of a powder of 50 μ or less, and in which the weight ratio of the elastomer to the organic polymer is in the range of 70:30 to 15:85,
Add and mix water in an amount of 10 to 95% by weight of the critical water addition amount defined herein to form a water-containing slurry, coat and/or impregnate a substrate with the water-containing slurry, and then remove the water from the substrate. 1. A method for producing a microporous structure, which comprises selectively evaporating an organic solvent (a) to gel an elastomer and an organic polymer, and then drying.