JPH069877A - Resin composition for synthetic leather using amidated protein - Google Patents

Abstract

PURPOSE:To provide a resin composition comprising a specific protein derivative and a thermoplastic resin in a specified ratio and giving synthetic leathers similar to natural leathers and excellent in its moisture retaining property, air permeability, skin touch, flexibility, fashionability, and toughness. CONSTITUTION:The composition comprises (A)5-80wt.% of an unsaturated group- containing protein amide compound obtained by amidating a protein such as gelatin with an unsaturated carboxylic acid (derivative) to elongate the side chains of the protein at their amino groups, or a protein derivative obtained by addition-polymerizing a vinyl monomer such as vinyl chloride or graft- polymerizing a synthetic polymer to the unsaturated groups existing on the side chains of the protein amide compound or obtained by graft-polymerizing the unsaturated group-having protein amide compound to the synthetic polymer, and (B) 95-20wt.% of a thermoplastic resin such as PE. The composition is coated or sprayed on nonwoven fabric and subsequently heated to provide a synthetic leather.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic leather resin composition using an amidated protein, and a synthetic leather having a moisturizing property, breathability and touch feeling similar to natural leather obtained by the composition.

[0002]

2. Description of the Related Art Natural leather has long been excellent in heat retention, breathability and hygroscopic swelling, and it has excellent softness and toughness without being sticky. Since it is excellent and has fashionability, it has been widely used as a cover for clothing or daily life items. However, such natural leather is expensive because it has a limited supply and requires a special technique for surface treatment, and cannot be easily used in daily life. Therefore, in recent years, hollow fibers as an alternative to natural leather, or artificial leather coated with synthetic resin or impregnated with a binder mainly composed of elastomer in a nonwoven fabric or woven fabric in which ultrafine fibers are entwined three-dimensionally, vinyl chloride, There has been provided synthetic leather such as vinyl leather which is made of synthetic resin foam such as polyamide and polyuretatan, or whose surface is coated with synthetic resin. However, the artificial leather and the synthetic leather described above have poor hygroscopicity, and are insufficient as materials having moisture retention, breathability, touch feeling, and the like similar to natural leather. Therefore,
In order to impart the characteristics possessed by natural leather, it is possible to pulverize natural leather or gelatin into powder, mix it with synthetic resin, and apply it to a non-woven fabric or woven fabric or foam to obtain synthetic leather. It is being appreciated.

Mixing of natural leather or gelatin and synthetic resin is not well compatible with each other, and natural leather or gelatin is not uniformly dispersed in the synthetic resin but exists as a lump, and a uniform one is difficult to obtain during molding. However, there is a problem that the adhesive strength between natural leather or gelatin and the synthetic resin is poor, and it is difficult to obtain a material having sufficient strength. Further, when leather powder is not uniformly dispersed in the molded product, heat shrinkage during molding between natural leather or gelatin and the synthetic resin,
There is a difference in the degree of swelling when dry and wet, which may cause unexpected distortion, wrinkling, or cracking of the molded product, which may impair the cosmetic appearance as leather. . An object of the present invention is to provide a synthetic leather resin composition having moisturizing properties similar to natural leather, breathability, touch feeling, and having sufficient strength, and synthetic leather obtained by the composition. .

[0004]

In view of the above situation, the present inventors have overcome the drawbacks of synthetic leather obtained by mixing conventional natural leather or gelatin with a synthetic resin, or artificial leather. The present inventors have made extensive studies to provide a resin composition for synthetic leather for manufacturing leather. as a result,
In order to improve the familiarity between the natural leather or gelatin and the synthetic resin, it suffices to impart hydrophobicity to the natural leather or gelatin, which is hydrophilic in nature, and for this purpose, the use of amidated protein has an excellent effect. The inventors have found that they can be obtained and reached the present invention.

That is, the gist of the present invention is (1) A. Amidation of a protein having an unsaturated group obtained by reacting a protein with an unsaturated carboxylic acid or a derivative of the carboxylic acid to perform amidation to extend the amino group of the side chain of the protein (hereinafter, simply referred to as a protein Amidated compound), or an unsaturated group present in the side chain of the amidated protein of the above protein, in the presence of a polymerization initiator, by addition polymerization of a vinyl monomer or by graft polymerization of a synthetic polymer, or by a synthetic polymer. Synthetic leather consisting of a protein derivative obtained by graft-polymerizing an amidation product of the protein having an unsaturated group (hereinafter, simply referred to as protein derivative: 5 to 80% by weight, and B: thermoplastic resin: 95 to 20% by weight) (2) A non-woven fabric of natural fibers or synthetic fibers or at least one side of a woven fabric After coating or spraying, it is synthetic leather obtained by heating, and (3) after coating or spraying to at least one surface of the composition a synthetic resin foam, to synthetic leather obtained by heating.

[0006] The amidated protein in the present invention means an amidated protein or a protein derivative of the protein, and specifically includes the following. That is, an amidation product of a protein is obtained by reacting an aqueous solution of a protein, a fine powder or a suspension thereof with a carboxylic acid or a carboxylic acid derivative having an unsaturated group to perform amidation, and to remove the amino group on the side chain of the protein. By prolonging, an amidated product of protein can be produced.

The protein used in the present invention is not particularly limited and various proteins can be mentioned. Examples thereof include gelatin, collagen, casein and the like. Further, leather powder such as chrome tanned leather containing these proteins, for example, leather powder such as cowhide, pig skin, sheep skin, etc. may be used.

As the carboxylic acid or carboxylic acid derivative, acrylic acid, propiolic acid, methacrylic acid, vinyl acetic acid, allyl acetic acid, crotonic acid, cinnamic acid or acrylic acid chloride, propiolic acid chloride, methacrylic acid chloride, vinyl acetic acid. Chloride,
Examples include allyl acetic acid chloride, crotonic acid chloride, cinnamic acid chloride, methacrylic anhydride, vinyl acetic anhydride, crotonic anhydride and the like. The amount of these carboxylic acids or carboxylic acid derivatives to be used is not particularly limited, but 0.0015 to 0.1 per 1 g of protein.
An amount of 0 mol is suitable. The amidation can be arbitrarily performed within a range of 10 to 100 ° C as a reaction temperature, and the time required for the reaction is unique because the amidation rate can be arbitrarily selected depending on the amount of the carboxylic acid or the carboxylic acid derivative and the reaction time. Although not specifically determined, it is usually selected within a range of 1 hour to 4 days. By reacting a carboxylic acid or a carboxylic acid derivative having such an unsaturated group with the above-mentioned protein, side chain amino groups such as lysine (Lys) and arginine (Arg) in the protein are amidated and chain-extended. . In this way, an amidated product of a protein having an unsaturated group derived from a carboxylic acid or a carboxylic acid derivative in the extended chain is obtained.

Further, the protein derivative uses a carboxylic acid or a carboxylic acid derivative having an unsaturated group similar to that used in obtaining the amidated product of the protein, and has an unsaturated group in the chain-extended side chain. Synthesis of an amidated protein, and then in the presence of a polymerization initiator at the unsaturated group,
A protein derivative can be produced by addition-polymerizing a vinyl monomer, graft-polymerizing a synthetic polymer, or graft-polymerizing an amidation product of a protein having the unsaturated group on the synthetic polymer. That is, there are various methods for producing a protein derivative using such an amidation product of a protein having an unsaturated group. Examples thereof include a method of performing addition polymerization with various polymerizable vinyl monomers using a conventional polymerization initiator, a graft polymerization of a synthetic polymer with an amidated product, and a graft polymerization of the synthetic polymer with an amidated product.

The above-mentioned polymerization initiator is, for example, benzoyl peroxide, azobisisobutyronitrile or the like, and known polymerization techniques such as radiation polymerization, ultraviolet polymerization or polymerization by mechanochemical reaction may be used. Further, as the polymerizable vinyl monomer, vinyl chloride, ethylene, styrene, methyl methacrylate, butadiene, chloroprene, and the like, as well as a silicon-based monomer can be used.

In the above, or in the above, the unsaturated group of the amidated product is cleaved by a polymerization initiator on the synthetic polymer or the molded product of the synthetic polymer to graft the amidated product on the synthetic polymer, or vice versa. It is carried out by grafting a polymer onto the amidation product. As the polymerization initiator used here, the same ones as listed above can be used. Further, examples of the synthetic polymer include polyvinyl chloride, polyethylene, polyamide resin, silicone rubber, polybutadiene rubber, polychloroprene rubber, and thermoplastic rubber. However, rubber can be grafted with a vulcanized product, but its effect is smaller than that of an unvulcanized product.

As the thermoplastic resin used in the present invention, usual ones can be used, and examples thereof include polyolefin resins such as polyethylene and polypropylene, ethylene-vinyl acetate copolymers, polyamide resins and polystyrene resins. Examples thereof include resins, polyester resins, thermoplastic rubber resins and the like.

The synthetic leather resin composition of the present invention is prepared by mixing such an amidated product or protein derivative of protein with a thermoplastic resin. As for the mixing ratio of the amidation product or protein derivative of protein and the thermoplastic resin, 95 to 20% by weight of the thermoplastic resin is suitable for 5 to 80% by weight of the amidation product or protein derivative of the protein. When the amount of amidated protein or protein derivative of protein is less than 5% by weight, the effect of modifying protein such as moisturizing property, breathability and touch feeling due to mixing of protein is not found, and 80% by weight is obtained.
If a larger amount is used, the amount of the thermoplastic resin becomes too small and molding is difficult, or the amidation product of the protein or the protein derivative may drop out from the obtained molded product, which is not preferable. The particle size of the amidated product or protein derivative of these proteins and the thermoplastic resin is not particularly limited, but in order for the two to be sufficiently mixed, the amidated product or protein derivative of the protein has no thermoplasticity and therefore it should be as fine as possible. Those having an average particle size of 500 μm or less, preferably 400
In many cases, when a product having a particle size of less than or equal to μm is used, a finished product having a smooth surface finish and a good texture can be obtained. However, in addition to the above-mentioned granular material, it is also possible to use an elliptical or fibrous material. For the mixing, a Henschel mixer or a Nauter mixer which is usually used is used. Further, a filler, a pigment, a short fiber or the like may be appropriately added to the composition of the present invention.

The synthetic leather of the present invention obtained using the resin composition for synthetic leather of the present invention (hereinafter sometimes simply referred to as the composition of the present invention) has two modes. (1) First embodiment Amidated protein or protein derivative 5-8
Synthetic leather obtained by applying or spraying the composition of the present invention comprising 0% by weight and a thermoplastic resin of 95 to 20% by weight to at least one side of a nonwoven fabric or a woven fabric of natural fibers or synthetic fibers, and then heating. That is, the synthetic leather of the present invention can be obtained by applying or spreading the composition of the present invention on at least one side of a non-woven fabric or a woven fabric of natural fibers, synthetic fibers, and heating. The properties of the synthetic leather obtained are
It is possible to make various changes depending on the type and shape of the non-woven fabric or woven fabric of natural fibers or synthetic fibers used, the mixing ratio of the amidation product or protein derivative of protein and the thermoplastic resin, the type of thermoplastic resin, and the like.

The natural fibers include hemp, cotton, silk, wool, etc.
As the synthetic fiber, a woven fabric or a non-woven fabric of ordinary fibers such as nylon, polyester and acrylic can be used. Further, fibers obtained by changing the shape of fibers such as hollow fibers obtained by recent technological advances can be used properly according to the purpose. The amount of the composition of the protein amidation product or protein derivative and the thermoplastic resin to be spread on the non-woven fabric or woven fabric of natural fibers or synthetic fibers is 5 to 2000 g / m ² , preferably 50 to 1
A suitable amount is 000 g / m ² . When a composition of a protein amidation product or a protein derivative and a thermoplastic resin is applied, the composition is made into a solution or an emulsion using an appropriate solvent, and the composition solid content is 5 to 5.
2000 g / m ^2, preferably from 50 to 1000 g / m ²
It may be applied so that When the amount is less than 5 g / m ² , the synthetic leather obtained has moisturizing properties similar to natural leather, breathability,
It is not sufficient to give a feeling of touch, and the use of more than 2000 g / m ² is not preferable because the thickness of the synthetic leather becomes thick and the use is limited. Examples of the solvent used here include dimethyl sulfoxide, methyl ethyl ketone, toluene, xylene and the like.

[0016] The composition of the protein amidation or protein derivative and the thermoplastic resin is applied or sprinkled onto the non-woven fabric or the woven fabric, and then the thermoplastic resin in the composition is melted by heating to bond with the non-woven fabric or the woven fabric. Then, it can be integrated to obtain synthetic leather. The heating temperature at this time is appropriately 10 to 50 ° C. higher than the melting point of the thermoplastic resin in the composition used. It goes without saying that the melting point is not higher than the melting point of the non-woven fabric or the woven fabric as the base material.

(2) Second embodiment Amidated protein or protein derivative 5-8
Synthetic leather obtained by applying or spraying the composition of the present invention comprising 0% by weight and a thermoplastic resin of 95 to 20% by weight on at least one side of a synthetic resin foam, and then heating. That is, the synthetic leather of the present invention can be obtained by applying or spreading the composition of the present invention on at least one side of a synthetic resin foam, and then heating the composition. Examples of the synthetic resin foam used here include synthetic resin foams such as vinyl chloride, polyamide, and polyurethane.

A suitable amount of the composition of the protein amidation product or protein derivative and the thermoplastic resin to be sprayed on the synthetic resin foam is 5 to 2000 g / m ² , preferably 50 to 1000 g / m ^2. . When a composition of a protein amidation product or a protein derivative and a thermoplastic resin is applied, the composition is made into a solution or emulsion using a suitable solvent, and the composition solid content is 5 to 2000 g / m. ² , preferably 50-1000
It may be applied so as to be g / m ² . A moisturizing effect similar to that of natural leather on synthetic leather obtained with an amount of less than 5 g / m ² ,
Not enough to give breathability and feel, 2000g
If you use more than / m ^{2, the} synthetic leather becomes thicker,
It is not preferable because it has limited applications.
Examples of the solvent used here include dimethyl sulfoxide, methyl ethyl ketone, toluene, xylene and the like.

After coating or spraying a composition of an amidation product of a protein or a protein derivative and a thermoplastic resin on a synthetic resin foam, the thermoplastic resin in the composition is melted by heating to form a synthetic resin foam. It can be adhered and integrated to obtain synthetic leather. The heating temperature at this time is 10 to 10 from the melting point of the thermoplastic resin in the composition used.
Temperatures higher by 50 ° C are suitable. It goes without saying that the melting point is not higher than the melting point of the synthetic resin foam used as the base material.

The synthetic leather resin composition of the present invention can be used not only as a raw material for producing the above-mentioned synthetic leather but also as a raw material for producing artificial leather. Artificial leather is usually 0.
An ultrafine fiber having a denier of 3 denier or less is used, which is formed into a random three-dimensional fiber entangled body and is impregnated with a binder mainly composed of a polyurethane elastomer. By incorporating the composition of the present invention into the binder component, It is also possible to obtain artificial leather that has moisturizing properties, breathability, and a feeling of touch that are close to those of natural leather.

[0021]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Production Example 1 94.6 g (dry weight) of alkali-treated gelatin (Konica Gelatin Co., Ltd., α-gelatin having a molecular weight of 100,000) was placed in an eggplant-shaped flask and dissolved in 200 g of distilled water.
Acrylic acid (25 g) was added thereto, and the mixture was reacted at 50 ° C. for 24 hours while stirring with a Magnetaster. In order to recover the obtained amidated product, water and acrylic acid which did not participate in the reaction were dried under reduced pressure at 80 ° C. for 24 hours. As a result, the yield of the obtained amidation product was 105 g, the average particle diameter was about 40 μm, and the amidation ratio due to the weight increase was 75%. The amidation ratio due to weight increase is measured by measuring the weight increase after washing and drying the protein after the reaction.
The weight increase due to the unsaturated carboxylic acid or the carboxylic acid derivative in the case of 100% amidation is taken as a theoretical value and expressed as a ratio to that value.

Production Example 2 95.2 g of the amidated gelatin obtained in Production Example 1 and 300 ml of a toluene solution of the radical initiator benzoyl peroxide of 2 mmol / liter were placed in a reaction vessel.
91.4 g of styrene monomer and 700 ml of toluene were added thereto, the atmosphere was replaced with nitrogen, and the mixture was reacted at 80 ° C. for 3 hours. Then, methanol was added to stop the reaction. The styrene monomer in the obtained graft product and polystyrene that did not participate in the binding were removed by washing with acetone to obtain 103 g of a protein derivative (gelatin / polystyrene complex).

Production Example 3 4.5 g of the amidated gelatin obtained in Production Example 1 and 50 g of vinyl chloride powder were placed in a reaction vessel, and 1 ml of a dimethylsulfoxide solution of radical initiator benzoyl peroxide 3 mmol / liter and 50 ml of toluene were placed therein. added. After purging with nitrogen, the mixture was reacted at 80 ° C. for 3 hours. Then, the reaction solution is filtered, and the residue is washed with ethanol,
After drying, 54.1 g of a protein derivative (gelatin / vinyl chloride graft complex) was obtained.

Production Example 4 Alkali-treated gelatin 1 same as that used in Production Example 1
00 g (dry matter 89.8 g) was put in an eggplant-shaped flask,
400 g of toluene and 25.0 g of acrylic acid were added thereto to make a suspension. After reacting at 20 ° C. for 24 hours with stirring, the reaction solution is filtered to wash the amidated gelatin obtained with 200 ml of toluene, filtered, and completely dried under reduced pressure at 80 ° C. for 24 hours to give 94 amidated gelatin. .6
g was obtained. The amidation ratio due to the increase in weight was 65%. The average particle size was about 40 μm.

Production Examples 5 to 6 Using the proteins, carboxylic acids and solvents shown in Table 1, the amidated product of the protein was obtained in the same manner as in Production Example 4.

[0026]

[Table 1]

Example 1 30 g of an amidated product (amidated gelatin) of the protein obtained in Production Example 1 and 70 g of polystyrene resin powder (trade name: "Vitax V-6702A" manufactured by Hitachi Chemical Co., Ltd.) having an average particle size of 150 μm. after thorough mixing, polypropylene nonwoven fabric (trade name "Tufnell PA-4021" by Mitsui petrochemical Industries, Ltd., 1 m ² per weight 100g) was uniformly sprayed on 1 m ^2. Then, it was heated to 120 ° C. to melt the polystyrene-based resin powder and fuse it to a non-woven fabric to obtain a synthetic leather. The surface of the obtained synthetic leather was leather-like, and its moisturizing properties, breathability, and touch were similar to those of natural leather.

Examples 2 to 6 In the same manner as in Example 1, the amidation products or protein derivatives of the proteins shown in Table 2 and the average particle size 400 μm
The mixture with the pulverized thermoplastic resin powder was sprinkled onto a 1 m ² non-woven fabric or woven fabric. Then, the thermoplastic resin powder was melted by heating and fused to a non-woven fabric or a woven fabric to obtain a synthetic leather. The surface of the obtained synthetic leather was leather-like, and its moisturizing properties, breathability, and touch were similar to those of natural leather.

[0029]

[Table 2]

Examples 7 to 9 By the same method as in Examples 2 to 6, amidated products or protein derivatives of the proteins shown in Table 3 and average particle size 40
A mixture with a thermoplastic resin powder pulverized to 0 μm or less was sprayed on a urethane synthetic resin foam having a thickness of 3 mm and an area of 1 m ² . Then, the thermoplastic resin powder was melted by heating and fused to obtain a synthetic leather. The surface of the obtained synthetic leather was leather-like, and its moisturizing properties, breathability, and touch were similar to those of natural leather.

[0031]

[Table 3]

Example 10 30 g of the amidated product (amidated gelatin) of the protein obtained in Production Example 1 and 70 g of polystyrene resin powder (trade name: "Vitax V-6702A" manufactured by Hitachi Chemical Co., Ltd.) having an average particle size of 150 μm. A urethane resin foam having a thickness of 3 mm and an area of 1 m ² after being dissolved in 1 kg of dimethyl sulfoxide (trade name “Clara Foam KM-54” manufactured by Kurabo Industries)
Applied on top. After evaporating dimethyl sulfoxide by drying at room temperature, the mixture was heated to 120 ° C., and a mixture of amidated gelatin and polystyrene was attached to a urethane resin foam and melted to obtain a synthetic leather. The surface of the obtained synthetic leather was leather-like, and its moisturizing properties, breathability, and touch were similar to those of natural leather.

[0033]

INDUSTRIAL APPLICABILITY The resin composition for synthetic leather of the present invention comprises a natural protein that is chemically modified to improve its compatibility with a thermoplastic resin, so that the chemically modified protein has a uniform thermoplasticity. It is distributed in the resin. Therefore, when the synthetic leather resin composition of the present invention is used to make synthetic leather, synthetic leather having moisturizing properties, breathability, touch feeling, and the like similar to natural leather can be obtained.

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Claims (9)

[Claims] 1. A. Amidation of a protein having an unsaturated group obtained by reacting a protein with an unsaturated carboxylic acid or a derivative of the carboxylic acid to perform amidation to extend the amino group of the side chain of the protein, or an amide of the protein In the presence of a polymerization initiator, an unsaturated group existing in the side chain of the compound is subjected to addition polymerization of a vinyl monomer or graft polymerization of a synthetic polymer, or an amidation product of a protein having the unsaturated group in the synthetic polymer. Derivatives obtained by graft polymerizing 5:80
%, And B: thermoplastic resin: 95 to 20% by weight, a resin composition for synthetic leather. 2. The resin composition for synthetic leather according to claim 1, wherein the protein is gelatin, collagen or casein. 3. The synthetic leather resin composition according to claim 1, wherein the protein is leather powder. 4. A. Amidation of a protein having an unsaturated group obtained by reacting a protein with an unsaturated carboxylic acid or a derivative of the carboxylic acid to perform amidation to extend the amino group of the side chain of the protein, or an amide of the protein In the presence of a polymerization initiator, an unsaturated group existing in the side chain of the compound is subjected to addition polymerization of a vinyl monomer or graft polymerization of a synthetic polymer, or an amidation product of a protein having the unsaturated group in the synthetic polymer. Derivatives obtained by graft polymerizing 5:80
%, And B: thermoplastic resin: 95 to 20% by weight, a synthetic leather obtained by applying or spraying a non-woven fabric of natural fibers or synthetic fibers or at least one side of a woven fabric, and then heating. 5. The synthetic leather according to claim 4, wherein the protein is gelatin, collagen or casein. 6. The synthetic leather according to claim 4, wherein the protein is leather powder. 7. A. Amidation of a protein having an unsaturated group obtained by reacting a protein with an unsaturated carboxylic acid or a derivative of the carboxylic acid to perform amidation to extend the amino group of the side chain of the protein, or an amide of the protein In the presence of a polymerization initiator, an unsaturated group existing in the side chain of the compound is subjected to addition polymerization of a vinyl monomer or graft polymerization of a synthetic polymer, or an amidation product of a protein having the unsaturated group in the synthetic polymer. Derivatives obtained by graft polymerizing 5:80
%, And B: thermoplastic resin: 95 to 20% by weight, a synthetic leather obtained by applying or spraying a composition comprising at least one side of a synthetic resin foam, and then heating. 8. The synthetic leather according to claim 7, wherein the protein is gelatin, collagen or casein. 9. The synthetic leather according to claim 7, wherein the protein is leather powder.