JPS5943585B2 - Resin composition for wet porous film formation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin composition for forming a wet porous coating for articles such as synthetic leather, which has excellent pressure resistance during molding of shoes, etc., and is easy to remove solvent. The object of the present invention is to provide the above-mentioned resin composition which provides a porous film having a pore structure with good properties.

Conventionally, synthetic leather-like articles have been manufactured by applying a solution of polyurethane resin, etc. dissolved in an organic solvent to the base material, and then applying a medium (generally water) that does not dissolve the resin but is miscible with the solvent in the solution. The resin is processed to solidify the resin onto the substrate and make the resin layer porous.

However, this method results in non-uniform pore structure and
Since complete extraction of the solvent is extremely difficult, conventionally various surfactants have been used to homogenize the pore structure and promote solvent removal.

However, the effects of these surfactants are still not sufficient, and a new drawback arises in that the quality of the formed porous resin layer deteriorates, and more importantly, the synthetic leather-like material formed in this way When processing and molding shoes or the like using a mold or the like, the pore structure is crushed, making it difficult to obtain a good molded product.

To this end, there is a conventional method of adding fillers such as calcium carbonate or pulp powder, but in this case, the physical strength of the porous layer itself, such as flexibility, decreases.

In addition, attempts have been made to change the composition and base material of the resin itself in order to prevent such collapse of the pore structure, but the result is that the porous layer becomes extremely hard, making it difficult to produce products with a soft texture. I couldn't get it.

The present inventors have conducted intensive research to solve the drawbacks of the conventional technology, and have found that when a certain substance is added to the conventional wet film forming resin composition, all of the above-mentioned problems can be solved. Even with compression molding, the pore structure is compressed when the pressure is applied, but after the pressure is released, the pore structure immediately returns to its original state.
The present invention was achieved by discovering that a molded product with a very soft texture can be obtained.

That is, the present invention provides (a) a film-forming resin material, (b)
This is a wet porous film-forming resin composition comprising vegetable oil, a derivative thereof, or a mixture thereof, and (C) an organic solvent that dissolves components a) and (b).

To explain the present invention in detail, the above component (a) constituting the composition of the present invention is a film-forming resin material that is insoluble in water, and any material known in the technical field can be used. Particularly suitable materials are polyurethane resins (including polyurethane urea groups).

These resins are elastic polymers obtained by reacting polymer polyols such as polyesters, polyethers, and polyacetals, organic diisocyanates, and chain extenders containing at least two active hydrogen atoms. Various additives such as vinyl chloride, polyacrylic acid alkyl ester, polyvinyl acetate, polystyrene, other resins, dyes and pigments, and various stabilizers can be blended.

Component (b) is a vegetable oil, a modified product thereof, or a mixture thereof, and preferred oils and fats for the present invention include linseed oil, eno oil, tung oil (produced in Japan), tung oil (produced in China), sunflower oil, and hempseed oil. oil, oiticica oil, poppy oil,
Drying oils such as safflower oil and mulberry oil, soybean oil, cottonseed oil,
Semi-drying oils such as sesame oil, rapeseed oil, bran oil, mustard oil, and corn oil; non-drying oils such as olive oil, castor oil, camellia oil, tea oil, fallen beef oil, sasanya oil, tonsil oil, camellia oil, and pen oil; Vegetable oils and fats such as cacao butter, coconut oil, wood wax, shea oil, kapok oil, and palm kernel oil, various modified products of such oils and fats, or mixtures thereof, and particularly preferred among these are linseed oil and palm kernel oil. Modified fats and oils include soybean oil, castor oil, coconut oil, camellia oil, etc., and their epoxidized modified oils, ethylene oxide adducts, and esterified products.

The amount of vegetable oil used is usually about 0.5 to 30 parts by weight, preferably about 1 to 30 parts by weight, from 100 parts by weight of the resin.
It is 10 parts by weight.

If the usage ratio exceeds the above upper limit, the smoothness of the wet solidification surface will be impaired, and the strength between micropores (interlaminar strength) will decrease, and in some cases, disadvantages such as the generation of oily bleed from the coating surface may occur. On the other hand, when the lower limit is exceeded, the desired effect of the present invention is not sufficient.

Component (e) is a component that can dissolve the above components (a) and (b), and preferred examples include dimethylformamide, diethylformamide, dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, acetone, etc., which are freely miscible with water. These solvents are organic solvents, and the amount of these solvents used is such that the solid content of the resulting composition of the present invention is about 1
The amount is ~30% by weight.

The essential components of the present invention are as described above, but various other additives used in the technical field can also be used as desired in amounts that do not impede the effects of the present invention.

The composition of the present invention comprising the above-mentioned components can be obtained by simply mixing and stirring the above-mentioned components.

Substrates to which the compositions of the present invention are applied include all substrates used in the art, such as woven fabrics, knitted fabrics,
The method of applying the composition is already well known. For example, after applying an appropriate amount of the composition of the present invention to a substrate, it is applied in a coagulation bath set at an appropriate temperature, preferably in water. The object of the present invention is achieved by processing and then performing various treatments such as drying.

According to the present invention, since the composition of the present invention includes the component (b) as described above, when the solvent is removed according to a conventional method after coating on a substrate, when the coated layer comes into contact with water, the coated layer The initial solidification of the solvent is relaxed and very uniform, fine pores are formed on the surface, so that the replacement of solvent and water, that is, desolvation, can be smoothly carried out through these initially formed pores.

On the other hand, in the case of conventional compositions that do not contain component (b), the initial solidification is rapid when they first come into contact with water, making it difficult to form pores uniformly on the surface. Replacement with the solvent does not occur smoothly, and it takes a long time to remove the solvent.

Therefore, when using the composition of the present invention, the solvent extraction in the coagulation bath is about 3 to 1
It is completed 0 times faster and more completely, and in addition, the micropore structure is formed extremely uniformly, and a product with a good texture rich in flexibility, thickness, drapability, etc. can be obtained.

The most noteworthy point is that when the product with the porous structure layer obtained as described above is molded into shoes, bags, band bags, and other products by applying pressure using a mold, etc. In the case of conventional products, the pores in the porous structure were crushed by pressure, and the pores were not restored, making it impossible to obtain a good product.In contrast, in the case of the present invention, the porous layer is soft. Even though the texture is soft, the original pore structure is immediately restored when the pressure is released, resulting in a molded product with a good and soft texture.

Next, the present invention will be specifically explained with reference to Examples and Comparative Examples.

Note that "%" or "%" in the text is based on weight.

Examples 1-2 and Reference Examples 1-2 Polyethylene butylene adipate with a molecular weight of about 2000,
4,4'-diphenylmethane diisocyanate and 1
- Polyurethane was obtained by reacting 4-butanediol at a molar ratio of 1:3:2, and this was dissolved in dimethylformamide to prepare a 30% resin solution.

The above solution was blended with other components as shown in Table 1 below, the resulting solution composition was completely defoamed, applied to a thickness of 1 mrIL on a glass plate, and immersed in warm water adjusted to 50°C for 30 minutes. After that, it was dried with hot air at about 80°C, and the performance of the obtained porous sheet was examined, and the results were as shown in Table 2.

In the above Table 2, in the case of Examples 1 and 2, the temperature was 50°C.
While sufficient desolvation was completed in 30 minutes, in the case of Reference Example 1, the desolvation was not completed even after 5 hours at 50°C, and in the case of Reference Example 2, the desolvation time was 3 hours at 50°C. It cost.

Examples 3-4 and Comparative Examples 3-4 Polybutylene adipate with a molecular weight of about 2000, 4.4-
Diphenylmethane diisocyanate and ethylene diamine were reacted in a molar ratio of 1:3.5:2.5 to obtain a polyurethane resin, which was dissolved in dimethylformamide to form a 30% solution.

Based on this solution, the formulations shown in Table 3 below were prepared,
After complete defoaming, about 1000? / m2 (as a solution), immersed in a 20°C water tank for 20 minutes and 50°C warm water for 15 minutes, squeezed out the water with a mangle, dried with hot air at 80°C, and made synthetic leather. I obtained the raw material for use.

The properties of this original fabric were as shown in Table 4 below.

In the case of Examples 3 and 4 in Table 4 above, 50°C1
While sufficient desolvation was completed in 5 minutes, in the case of Reference Example 3, the desolvation was not completed even after 5 hours at 50°C, and in the case of Reference Example 4, the desolvation time was 3 hours at 50°C. It cost.

Claims (1)

[Scope of Claims] 1 (a) a film-forming resin material, (b) a vegetable oil or a derivative thereof, or a mixture thereof; and (e) the above (
A wet porous film-forming resin composition comprising an organic solvent capable of dissolving component (a) and (b). 2. The composition according to claim 1, wherein the component (a) is a polyurethane resin material. 3(b) Ingredients are castor oil, soybean oil, coconut oil, linseed oil,
The composition according to claim 1, which is camellia oil or a modified product thereof. 4. The composition according to claim 1, wherein component 4(c) is dimethylformamide, diethylformamide, acetamide or dimethylsulfoxide.