JPS5856569B2 - 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 film constituting articles such as synthetic leather, and when applied to shoes etc., it improves damage caused by repeated bending fatigue and abrasion deterioration. The object of the present invention is to provide a resin composition that provides a porous coating having a pore structure with good properties.

Conventionally, synthetic leather-like articles have been produced by coating a base material with a solution of polyurethane resin or the like dissolved in an organic solvent, and then applying a medium that does not dissolve the resin but is miscible with the solvent in the solution (generally water) to coagulate the resin as a porous resin layer on the base material, and then treat the surface with a coloring agent or the like.

However, it is difficult to form a porous film with good properties using such a general method, and various methods have been developed to form a film by adding various compounds, fillers, etc. to the film-forming resin solution. Although the pore structure of the resulting film is improved to some extent by this method, the repeated bending fatigue resistance and abrasion deterioration resistance are not satisfactory when processed into shoes, etc. No improvement.

It is known that repeated bending fatigue and abrasion deterioration of shoes made of synthetic leather are generally caused by the inherent characteristics of the constituent resin, and are also greatly affected by the cell structure of the porous coating. There is.

Although the conventional improvement method using additives as described above improves the cell structure to some extent, the cell structure is not sufficiently uniform and many large pores are generated.

Other methods to improve the above drawbacks include changing the composition of the coagulation bath, extending the coagulation time, and modifying the coagulation bath, but these methods require complicated control of various conditions and are difficult to manufacture. This method has low performance and cannot be called a practical method.

As a result of intensive research in order to solve the above-mentioned drawbacks of the conventional technology, the present inventors added a plurality of specific compounds in a specific ratio to a conventional wet-type porous film-forming resin composition. The present invention was completed based on the finding that the drawbacks of the prior art can be substantially solved.

That is, the present invention & East a) film-forming polyurethane resin material, (b) glyceride compound, (c) sorbitan surfactant, (d) propylene oxide/ethylene oxide copolymer, and (e) above Ha a) −(d
) A polyurethane resin composition for forming a wet porous film, which is made of an organic solvent that dissolves all of the components.

To explain the present invention in detail, the component (a) used in the composition of the present invention is a film-forming polyurethane resin (including polyurethane urea resin) which is insoluble in water.

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 mainly a vegetable oil, a modified product thereof, or a mixture thereof, and preferred components for the present invention include, for example, linseed oil, eno oil, tung oil (produced in Japan), tung oil (produced in China), sunflower oil, Hempseed oil, Oiticica oil,
Poppy oil 1, drying oils such as saffron oil and mulberry oil, semi-drying oils such as soybean oil, cottonseed oil, sesame oil, rapeseed oil, bran oil, mustard oil, corn oil, olive oil, castor oil, camellia oil, tea oil, Non-drying oils such as fallen raw oil, sasanqua oil, tonsil oil, camellia oil, pen oil, cacao butter, coconut oil, wood wax, shea oil,
Vegetable oils and fats such as kapok oil and balm oil, various modified products of such oils and fats, or mixtures thereof, and among these, particularly preferred are linseed oil, soybean oil, castor oil, coconut oil, camellia oil, etc. Modified oils and fats such as epoxidized modified oils, ethylene oxide additives, and esterified products.

Component (C) includes, for example, sorbitan monolaurate, monopalmitate, monostearate, tristearate, trioleate, polyoxyethylene sorbitan monooleate, monostearate, monopalmitate, tristearate, trioleate, etc. is preferred.

Component (d) is a copolymer of propylene oxide and ethylene oxide, and its molecular weight range is not particularly important, but its copolymerization ratio is important, and the ethylene oxide content in the copolymer is approximately It ranges from 30 to 70% by weight, preferably about 40 to 60% by weight.

Component (e) is an organic solvent that can dissolve all of the above components (a) to (d), and preferred examples include dimethylformamide, diethylformamide, dimethylacetamide, dimethylsulfoxide, tetrahydrofuran,
It is an organic solvent that mixes freely with water, such as acetone,
The amount of these solvents used is such that the resulting composition of the present invention has a solids content of about 1 to 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.

Particularly important technical matters in the composition of the present invention are the combined use of the above components (b) to (d), the ratio of these components to component (a), and the use of the same components (mb) to (d). It is a percentage.

That is, the total amount of component (b), component (C), and component (d) is 0.1 to 30 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of component (a), and these ( The usage amount of each of the three components b) to (d) is (b):
(c): (d) is 5-20: 1-10 near 0-90
A weight ratio of 0 is preferred.

By using the components (b) to (d) in such proportions, the cell structure of the resulting film is so fine and uniform that it cannot be seen with the naked eye, and there is no generation of large pores.

Regarding component (b), if the above upper limit of usage ratio is exceeded, the smoothness of the wet solidification surface will be impaired, and the strength between micropores (interlaminar strength) will decrease, and in some cases, oil buildup from the surface of the coating will occur. Defects such as generation of bleed products occur, and on the other hand, when the lower limit is exceeded, the desired effect of the present invention is not sufficient.

Regarding component (c), if the above-mentioned usage ratio exceeds the upper limit, giant pores will occur between the formed coating and the base material, which is not preferable.

On the other hand, if the lower limit is exceeded, the coagulation time becomes slow, resulting in disadvantages such as insufficient effects aimed at by the present invention, which is not preferable.

Regarding component (d), if the ethylene oxide content exceeds the upper limit of the above-mentioned range, the cells will become gigantic, and if it exceeds the lower limit, the cell formation will be delayed, both of which are undesirable.

Moreover, if the amount used exceeds the upper limit of the range of the amount used, the cell density of the entire coating layer will decrease, and if it exceeds the lower limit, the coagulation time will be delayed, both of which are undesirable.

Furthermore, if the total of the components b) to (d) above exceeds the upper limit of the above range, the strength between the micropores may decrease, and oily substances may bleed from the surface of the coating.

Moreover, if the lower limit is exceeded, the effects of the present invention, such as formation of cells with uniform micropores and shortening of solidification time, will not be achieved satisfactorily.

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, the solvent extraction in the coagulation bath is significantly faster and more complete than with conventional compositions, and the micropore structure is extremely uniformly formed, resulting in flexibility, thickness, and A product with a good texture and drapability can be obtained.

The most noteworthy point is that when the product with the porous structure layer obtained as described above is applied to shoes, bags, etc., there is no damage due to repeated bending fatigue, wear and tear deterioration, etc.
The objective is to significantly improve the performance of such articles.

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

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

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

The above solution was mixed with other components as shown in Table 1 below, and the resulting solution composition was completely defoamed, coated on a glass plate to a thickness of about 1 inch, and heated with 4% dimethylformamide at 25°C. After immersing the porous sheet in water for 15 minutes, the solvent was removed with warm water at 50°C for 30 minutes, and the porous sheet was dried with hot air at 100°C.

Comparative Example of Use The resin compositions of Example 1 and Reference Example 3 were each applied onto a raised fabric at a rate of about 1000 f/m2, and the solvent was removed in water at 25°C for 30 minutes and then in mixed water at 50°C for 2 hours. to completely remove dimethylformamide, then 10
Hot air drying was performed at 0°C.

A surface treatment agent was applied to the surface of each of the formed porous resin layers to obtain synthetic leather.

When this synthetic leather was subjected to a repeated bending test at -10°C using a flexographic cold resistance bending tester, the one using the resin composition of Example 1 was able to pass 200,000 times, whereas the one using the resin composition of Reference Example 1 Those using the composition were out 50,000 times.

*Example 2 and Reference Examples 5 to 6 Various additives were added to the same resin solution as in Example 1 to obtain the resin compositions shown in Table 3 below, and these compositions were prepared in the same manner as in Example 1. Apply it to a thickness of 1 on a glass plate, and
Wet coagulation was carried out in water at 5°C.

At that time, a 5001 weight was placed on the coagulation film for 15 seconds at 1-minute intervals, and the point at which no trace remained was determined as the coagulation time. In the case of the composition of Example 1, it was 11 minutes, and in the case of the composition of Reference Example 5. 15 minutes for the composition of Reference Example 6, and 16 minutes for the composition of Reference Example 6.
It was found that the solidification time of the resin composition of the present invention was very excellent.

Claims (1)

[Scope of Claims] 1 (a) film-forming polyurethane resin material, (b) glyceride compound, (c) sorbitan surfactant, (
d) A polyurethane resin composition for forming a wet porous film, comprising a propylene oxide/ethylene oxide copolymer and (e) an organic solvent that dissolves all of the components a) to (d). 2. The composition according to claim 1, wherein the ethylene oxide content in the propylene oxide/ethylene oxide copolymer is 30 to 70% by weight. 3 (b) component = (C) component: (d) component is 5 to 2 by weight
0:1-10 nia 0-90.