JPH05339507A - Esterified protein/resin composition for synthetic leather - Google Patents

Abstract

PURPOSE:To obtain a resin composition from which a synthetic leather almost comparable to a natural leather in moisture retention, air permeability, touch, etc., can be produced, by mixing a chemically modified protein with a thermoplastic resin. CONSTITUTION:The title composition comprises 95-20wt.% thermoplastic resin and 5-80wt.% protein derivative obtained either by esterifying a protein by reacting it with a polyhydric alcohol to extend a carboxyl side chain of the protein, or by modifying the ester by further reacting the alcohol-derived functional group present in the side chain. A (non)woven fabric made of natural or synthetic fibers or a synthetic resin foam is coated or sprayed on at least one side with the composition and then heated to obtain a synthetic leather. This leather is almost comparable to a natural leather in moisture retention, air permeability, touch, etc.

Description

Detailed Description of the Invention

[0001]

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

[0002]

BACKGROUND OF THE INVENTION Natural leather has long been superior in heat retention, breathability, and moisture swelling, giving it a non-greasy feel and softness and toughness. Since it is excellent and has fashionability, it has been widely used as a cover for clothing or furniture, sports equipment, daily necessities, etc.
However, such natural leather is expensive because it has a limited supply and requires a special technique for surface treatment, and cannot be used easily in daily life. Therefore, in recent years as an alternative to natural leather, hollow fibers, or artificial leather in which a nonwoven fabric or woven fabric in which three-dimensionally entwined ultrafine fibers are impregnated with a binder mainly composed of an elastomer or a synthetic resin is applied, vinyl chloride, or polyamide , Synthetic leather such as vinyl leather, which is made of synthetic resin foam such as 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 a material having moisture retention, breathability, and touch feeling similar to natural leather. Therefore, in order to impart the characteristics that natural leather has,
Natural leather, gelatin, etc. are crushed into powder form, mixed with synthetic resin and applied to non-woven fabric or woven fabric to make synthetic leather, or applied to foam to make synthetic leather. There is.

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 natural leather or gelatin has a poor affinity for synthetic resin, and it is difficult to obtain a product 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 during dry and wet conditions, which may cause unexpected distortion, wrinkling, or cracking of the molded product, which may not be leather-like and impair its beauty. There is. An object of the present invention is to provide a synthetic leather resin composition having a moisturizing property similar to natural leather, breathability, a touch feeling, and a sufficient strength, and a synthetic leather obtained by the composition. ..

[0004]

In view of the above situation, the present inventors have overcome the disadvantages 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 synthetic leather resin composition for producing 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 originally hydrophilic, and for this purpose, it is better to use an esterified protein. The inventors have found that the above effects can be obtained and have reached the present invention.

That is, the gist of the present invention is (1) A. Esterification is performed by reacting a protein with a polyfunctional alcohol to form an esterified product of a protein in which the carboxyl group of the side chain of the protein is chain-extended (hereinafter simply referred to as an esterified product of the protein) or an esterified product side chain of the protein. Synthesis of protein derivative (hereinafter simply referred to as protein derivative) obtained by further reacting an existing polyfunctional alcohol-derived functional group: 5 to 80% by weight, and B: thermoplastic resin: 95 to 20% by weight Resin composition for leather, (2) Synthetic leather obtained by applying or spraying the composition on at least one side of a non-woven fabric or a woven fabric of natural fibers or synthetic fibers, and (3) foaming the composition with synthetic resin The present invention relates to synthetic leather obtained by applying or spraying on at least one side of a body and then heating.

The esterified protein in the present invention is
It means an esterified product or a protein derivative of a protein, and specifically the following are exemplified. (1) An aqueous solution of protein, a fine powder or a suspension thereof is reacted with excess polyfunctional alcohol for esterification, and an esterified product of a protein in which a carboxyl group of a protein side chain is extended, (2) polyfunctional Using a polyhydric alcohol as the alcohol, a protein derivative urethanized by reacting a compound having an isocyanate group with a hydroxyl group derived from the polyhydric alcohol present in the chain-extended side chain,
(3) A polyhydric alcohol is used as the polyfunctional alcohol, a compound having an epoxy group is reacted with a hydroxyl group derived from the polyhydric alcohol present in the chain-extended side chain, and then the resin derivative is resinified, and (4 ) An alcohol having an unsaturated bond is used as the polyfunctional alcohol, and a vinyl monomer is subjected to addition polymerization in the presence of a polymerization initiator to an unsaturated group derived from the alcohol present in the chain-extended side chain, or a synthetic high It is a protein derivative in which a molecule is graft-polymerized or an esterified product of the protein having the unsaturated group is graft-polymerized in a synthetic polymer.

In order to synthesize such an esterified product or protein derivative of the protein used in the present invention, the first step is to react the carboxyl group of the side chain of the amino acids constituting the protein with a polyfunctional alcohol. Chain extension by esterification to prepare an esterified product of a protein having a functional group derived from a polyfunctional alcohol in the protein side chain. And as the second stage,
Organic solvents such as toluene, dimethylformamide,
Epoxy resin or urethane resin raw material compounds or other compounds were obtained from the esterified product obtained in the first step in a solvent such as ethyl acetate, tetrahydrofuran, cyclohexane, dimethyl sulfoxide, etc. By combining the so-called conventional polymerization techniques such as addition polymerization of the polymerizable vinyl monomer of, or graft polymerization with a synthetic polymer,
Produce a protein derivative.

Such a manufacturing method will be described in detail for each mode. (1) First embodiment (production of protein esterified product): A protein aqueous solution, a fine powder or a suspension thereof is reacted with an excess of a polyfunctional alcohol to effect esterification to remove a carboxyl group of a protein side chain. By chain extension, an esterified product of protein can be produced. The protein used in the present invention is not particularly limited, and examples thereof include gelatin, collagen,
Casein etc. are illustrated. Also, leather powders for leather such as chrome tanned leather containing these proteins, eg cowhide,
You may use leather powders such as pig skin and sheep skin.

In the present invention, an aqueous solution of protein,
An esterified product of a protein can be obtained by adding a polyfunctional alcohol to a fine powder or a suspension thereof and performing an esterification reaction. Examples of the polyfunctional alcohol used herein include polyhydric alcohols such as diethylene glycol, triethylene glycol, polyethylene glycol, glycerin or butanediol, propanediol, or allyl alcohol, hydroxyethyl acrylate, hydroxyethyl methacrylate, 4-allyl catechol, allyl carbyl. Examples thereof include alcohols having an unsaturated bond such as norol, and may be alcohols having an epoxy group.

The amount of these polyfunctional alcohols used is
Although not particularly limited, an excess amount is usually used with respect to the carboxyl group in the protein, and specifically, an amount of 0.0015 to 0.1 mol per 1 g of the protein is an appropriate amount. The esterification reaction temperature is usually 10 to 1
The reaction can be performed at any temperature within the range of 00 ° C., and the time required for the reaction is not uniquely determined because the esterification rate can be arbitrarily selected depending on the amount of the polyfunctional alcohol used and the reaction temperature, but usually 1 hour to It is selected within a range of 4 days. By reacting these polyfunctional alcohols with the protein, glutamic acid (Glu) in the protein,
A side chain carboxyl group such as aspartic acid (Asp) is esterified to extend the chain. The chain thus extended gives esterified products of proteins having various functional groups derived from polyfunctional alcohols. For example, among the above polyfunctional alcohols, when a polyhydric alcohol is used, an esterified product of a protein having a hydroxyl group in the extended chain is obtained, and when an alcohol having an unsaturated bond is used, , An esterified product of a protein having an unsaturated group in the extended chain is obtained.

(2) Second mode (production of protein derivative): In the above-mentioned first mode, a polyhydric alcohol is used as the polyfunctional alcohol, and a hydroxyl group derived from the polyhydric alcohol is added to the chain-extended side chain. A protein derivative can be produced by synthesizing an esterified product of the protein having and then reacting the compound having an isocyanate group with the hydroxyl group to form a urethane. Examples of the polyhydric alcohol used here include alcohols having two or more hydroxyl groups in the molecule, such as diethylene glycol, triethylene glycol, polyethylene glycol, glycerin or butanediol, propanediol among the above-mentioned polyfunctional alcohols. Is mentioned. The method for urethane-forming the hydroxyl group present in the extended side chain of the obtained esterified product is carried out by reacting the esterified product with a compound having an isocyanate group.
Specifically, for example, the esterified product may be reacted with a compound having an isocyanate group and then urethanized with a polyol or a diamine. Further, as a compound having an isocyanate group, a prepolymer of a terminal diisocyanate is used to react with the esterified product to form a urethane,
It may be a protein derivative. The compound having an isocyanate group, the polyol, and the diamine used here can be selected according to the purpose and are usually general-purpose ones.

(3) Third mode (production of protein derivative): In the above-mentioned first mode, a polyhydric alcohol is used as the polyfunctional alcohol, and a hydroxyl group derived from the polyhydric alcohol is added to the chain-extended side chain. A protein derivative can be produced by synthesizing an esterified product of the protein, then reacting the compound having an epoxy group with the hydroxyl group, and further converting the compound into a resin. As the polyhydric alcohol used here, the same one as in the case of the second aspect is used. As the compound having an epoxy group, for example, epichlorohydrin and the like can be mentioned, and after the esterification product is epoxidized using this, for example, polyhydric phenol may be reacted to be resinified sequentially, or terminal epoxidized. The resin may be reacted with the hydroxyl group of the esterified product to give a protein derivative.

(4) Fourth Aspect (Production of Protein Derivative): In the above-mentioned first aspect, an alcohol having an unsaturated bond is used as the polyfunctional alcohol, and an unsaturated bond is added to the chain-extended side chain. Alcohol-derived unsaturated group-containing protein esterification product is synthesized, and then vinyl monomer is added to the unsaturated group in the presence of a polymerization initiator, or a synthetic polymer is graft-polymerized, or A protein derivative can be produced by graft-polymerizing an esterified product of a protein having the unsaturated group on the molecule. Examples of the alcohol having an unsaturated bond used here include allyl alcohol, 4-allylcatechol, and allylcarbinol as described above. There are various methods for producing a protein derivative using such an esterified product having an unsaturated group. Examples thereof include a method in which a conventional polymerization initiator is used for addition polymerization with various polymerizable vinyl monomers, a synthetic polymer is graft-polymerized with an ester compound, and an ester compound is graft-polymerized with the synthetic polymer.

The above-mentioned polymerization initiator is, for example, benzoyl peroxide, azobisisobutyronitrile or the like, and a known polymerization technique utilizing radiation polymerization, ultraviolet polymerization or polymerization by mechanochemical reaction is used. May be. 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 unsaturated group of the esterified product is cleaved by a polymerization initiator on the synthetic polymer or synthetic polymer molded article, the esterified product is grafted to the synthetic polymer, or vice versa. It is carried out by grafting onto the esterified 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, silicon rubber, polybutadiene rubber, chloroprene rubber, and thermoplastic rubber. However, rubber can be grafted with a vulcanized product, but its effect is smaller than that of an unvulcanized product.

The protein derivative of the present invention is obtained by each of the second to fourth aspects with the esterified product obtained by the above-mentioned first aspect as an intermediate. The structural feature of the protein derivative thus obtained is that the side chain of the protein has a urethane bond (obtained in the second mode), and the side chain of the protein is epoxidized (in the third mode). (Obtained), and that the synthetic polymer is bound to the side chain of the protein (obtained in the fourth aspect).

The esterification product or protein derivative of such a protein is used to prepare a synthetic leather resin composition by mixing it with a thermoplastic resin.
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, holamide-based resins, polystyrene-based resins and polyesters. Examples of the resin include a thermoplastic resin and a thermoplastic rubber resin. The mixing ratio of the above-mentioned protein esterified product or protein derivative and the thermoplastic resin is 5 to 80% by weight of the protein esterified product or protein derivative, and 95 to 20% by weight of the thermoplastic resin is suitable. If the amount of esterified protein or protein derivative is less than 5% by weight, the effect of modifying moisture retention, breathability, and touch is not found, and if more than 80% by weight, the amount of thermoplastic resin decreases. However, it is not preferable because it may be difficult to mold and the esterified product of the protein or the protein derivative may be dropped from the obtained molded product. The particle size of the esterified product or protein derivative of these proteins and the thermoplastic resin is not particularly limited, but in order to sufficiently mix the two,
Esterified products or protein derivatives of proteins have no thermoplasticity, so they should be as small as possible.
In many cases, a molded product obtained by using one having a thickness of 500 μm or less, preferably 300 μm or less, has a smooth surface finish and a good texture. 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 by using the synthetic leather resin composition of the present invention (hereinafter sometimes simply referred to as the composition of the present invention) has two modes. (1) First embodiment Protein esterified product or protein derivative 5
A synthetic leather obtained by applying or spraying the composition of the present invention comprising 80% by weight and a thermoplastic resin of 95 to 20% by weight to at least one side of a woven or non-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 spraying the composition of the present invention on at least one side of a woven or non-woven fabric of natural fibers or synthetic fibers, and heating. The properties of the obtained synthetic leather are variously changed depending on the type and shape of the natural fiber, the synthetic fiber woven or non-woven fabric used, the mixing ratio of the protein esterification product or protein derivative and the thermoplastic resin, the type of the thermoplastic resin, etc. It is possible.

As the natural fibers, 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. In addition, hollow fibers and other fibers obtained by recent technological advances with various shapes can also be used depending on the application. The amount of the composition of the esterified product or protein derivative of the protein and the thermoplastic resin applied onto the woven or non-woven fabric of natural fibers or synthetic fibers is 5 to 2000 g / m ² , preferably 50 to
A suitable amount is 1000 g / m ² . When a composition of a protein esterification product or protein derivative and a thermoplastic resin is applied, the composition is made into a solution or emulsion using an appropriate solvent, and the composition solid content is 5 to 2000 g / m. ² , preferably 50 to 1000 g /
It may be applied so as to be m ² . An amount of less than 5 g / m ² is not enough to give the synthetic leather a moisturizing property, breathability and touch feeling similar to natural leather, and 2000 g / m 2
^The use of more than ² is not preferable because the thickness of the synthetic leather becomes thicker and the use is limited. Examples of the solvent used here include dimethyl sulfoxide, methyl ethyl ketone, toluene, xylene and the like. After coating or spraying a composition of a protein esterification product or protein derivative and a thermoplastic resin on a woven or non-woven fabric, the thermoplastic resin in the composition is melted by heating and is bonded and integrated with the woven or non-woven fabric. It is possible to obtain synthetic leather. The heating temperature at this time is 10 from the melting point of the thermoplastic resin in the composition used.
Temperatures up to ~ 50 ° C are suitable. It goes without saying that the melting point is not higher than the melting point of the woven fabric or nonwoven fabric as the base material.

(2) Second embodiment Protein esterified product or protein derivative 5
A synthetic leather obtained by applying or spraying the composition of the present invention comprising 80% 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 the composition.
That is, the synthetic leather of the present invention can be obtained by applying or spraying 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 esterified product or protein derivative of protein and the thermoplastic resin is sprayed onto the synthetic resin foam is 5 to 2000 g / m ² , preferably 50 to 1000 g / m ^2. .. When a composition of a protein esterification product or protein derivative and a thermoplastic resin is applied, the composition is made into a solution or emulsion using an appropriate solvent, and the composition solid content is 5 to 2000 g / m. ² , preferably 50 to 10
It may be applied so that the amount becomes 00 g / m ² . If the amount is less than 5 g / m ² , it is not enough to give the obtained synthetic leather a moisturizing property, breathability and touch feeling similar to natural leather.
Use of more than 0 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. After coating or spraying a composition of an esterification 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 and adheres to the synthetic resin foam, It can be 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 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 having moisturizing properties, breathability, and touch feeling that are close to those of natural leather.

[0022]

EXAMPLES The present invention will be described in detail below with reference to production examples and examples, but the present invention is not limited to these examples. Production Example 1 A 500 ml separable flask equipped with a stirrer was treated with an alkali-treated gelatin (Konica Gelatin Co., Ltd., molecular weight: about 10).
45 g (dry matter) of 10,000 alpha gelatin) is added, and this is dissolved in 100 ml of distilled water. Next, 50 ml of allyl alcohol was added and reacted at 50 ° C. for 24 hours. In order to recover the esterified product, water as a solvent and excess allyl alcohol that did not participate in the reaction were evaporated under reduced pressure at 50 ° C., and subsequently, they were completely dried and removed under reduced pressure at 80 ° C. for 24 hours. The obtained esterified product was dissolved again in 100 ml of distilled water, and the same operation as above was repeated 3 times. As a result, the yield of the esterified product reached a constant amount. The final yield was 48 g. The fine powder obtained is a diffuse reflection method F.
The absorption at 1724 cm ⁻¹ by T-IR and the color reaction with hydroxamic acid-iron (III) confirmed the presence of an ester bond from the color change from yellow to magenta. Further, it was found from a 200 MHz NMR analysis that about 91% of the carboxyl groups of gelatin were esterified products of gelatin (gelatin / allyl alcohol).

Production Example 2 51 g of chrome-tanned leather (cowhide) powder pulverized to about 10 μm or less in terms of dry matter was placed in a 500 ml separable flask equipped with a stirrer together with 50 ml of allyl alcohol to be in a suspended state, and stirred at 50 ° C. The reaction was carried out for 24 hours. Next, excess allyl alcohol was distilled off under reduced pressure and then completely distilled off under reduced pressure at 40 ° C. for 24 hours. The obtained esterified product was washed with 100 ml of distilled water,
A small amount of alcohol was removed by the same method as in Production Example 1.
As a result of repeating this operation three times, the yield of the esterified product (chromic tanned leather / allyl alcohol) reached a constant amount.
The final yield obtained was 52.4 g, and the esterification rate due to weight increase was about 37%.

Production Example 3 50 ml in a 500 ml separable flask equipped with a stirrer
Diethylene glycol and 53 g casein (reagent 1
Grade) and 0.1N HCl (50 ml) were added, and the reaction was performed while maintaining the temperature at 50 ° C. with stirring. After reacting for 24 hours, the reaction was stopped, the reaction product was precipitated in methanol, and washed repeatedly with water to completely remove diethylene glycol that did not participate in binding. This was air-dried and further dried under reduced pressure to remove a trace amount of water. As a result, 5
3.6 g of esterified product (casein / diethylene glycol) was obtained.

Production Example 4 40 g of the esterified product (gelatin / allyl alcohol) obtained in Production Example 1 and 100 ml of a 2 mmol / liter toluene solution of a radical initiator benzoyl peroxide (hereinafter referred to as BPO) were mixed with 1 liter equipped with a stirrer. After being placed in a separable flask, 38 g of styrene monomer and 250 ml of toluene were further added, and after substitution with nitrogen, reaction was carried out at 80 ° C. for 3 hours. Then, methanol was added to stop the reaction, and then the styrene monomer in the obtained graft product and polystyrene not involved in binding were removed by washing with acetone to obtain 43 g of a protein derivative (gelatin / polystyrene graft product). It was

Production Example 5 In a 300 ml separable flask equipped with a stirrer, 50 g of vinyl chloride powder and 4.5 g of the esterified product (gelatin / allyl alcohol) obtained in Production Example 1 were placed, and then 3 m
1 ml of a dimethylsulfoxide solution of mol / liter BPO and 50 ml of toluene were added and reacted at 80 ° C. for 3 hours. After filtering with a Nutze, it was thoroughly washed with ethanol and then dried to obtain 54.3 g of a protein derivative (gelatin / vinyl chloride graft product).

Production Example 6 86% of gelatin obtained in the same manner as in Production Example 3 except that butanediol was used in place of diethylene glycol and gelatin was used in place of casein.
The esterified product (gelatin / butanediol) was dried under reduced pressure at 80 ° C. for 24 hours to remove water, and then 10.2
g was dissolved in dimethyl sulfoxide to give a solution of about 15%. While stirring this solution, tolylene diisocyanate was added at an equivalent ratio of -NCO / OH of 1.02 to obtain a protein derivative (gelatin / urethane compound complex).

Production Example 7 50 g of an esterified product (gelatin / butanediol) obtained in the same manner as in Production Example 6 and 2 g of caustic soda were added to 250 m.
It was dissolved in 1 l of distilled water. On the other hand, 20 ml of epichlorohydrin was placed in a three-necked flask equipped with a dropping funnel containing 50 ml of dimethyl sulfoxide and a condenser. Next, a caustic soda solution of the esterified product was dropped from the dropping funnel over about 10 minutes, and the reaction was carried out for 5 hours while stirring. After the reaction, the mixture was poured into excess acetone, filtered, washed, and then vacuum dried to obtain an esterified epoxidized intermediate. Subsequently, 40 g of this epoxidized intermediate was dissolved in 250 ml of dimethylsulfoxide. This solution was placed in a three-necked flask equipped with a condenser and a dropping funnel, heated to 50 ° C., and 85 mmol of bisphenol A was added. After dissolution, gradually add a 40% caustic soda solution in an equimolar amount to bisphenol A,
The reaction was carried out for 6 hours. After stopping the reaction, the reaction product was filtered with excess acetone and washed repeatedly.

Next, in order to remove the caustic soda contained therein, the reaction product was put in a bisking tube and the pH was adjusted.
After dialysis in a sodium borate solution of 7.2 for 2 days,
When dried, about 53 g of product was obtained. In order to modify 53 g of this into a curable resin, the same procedure as the above-mentioned epoxidation intermediate was repeated to obtain a protein derivative (protein / epoxy compound complex) in which the terminal hydroxyl group was epoxidized. Obtained.

Production Example 8 46.8 g of the esterified product (casein / diethylene glycol) of Production Example 3 which had been dried under reduced pressure at 60 ° C. for 24 hours to remove water and 100 ml of dimethyl sulfoxide were placed in a reaction vessel. Next, while stirring the solution with a stirrer, 9.52 g of butanediol and 100 ml of
Dimethylsulfoxide solution of No. 3, and then 3.6.
A solution of g of diphenylmethane diisocyanate in 50 ml of dimethylformamide was added. Next, the reaction vessel was heated to 50 ° C. and reacted for about 2 hours, then the reaction product was precipitated in methanol to recover the polymer, and the unreacted mixture remaining in the polymer was soaked with ethyl acetate for 24 hours. Extracted. As a result, the obtained protein derivative (protein / urethane compound complex) was powdery.

Production Example 9 A toluene solution containing 3 mmol / liter of BPO in 50 m
1), put this solution in a polymerization tube,
52.5 g of the esterified product (gelatin / allyl alcohol) (fine powder) obtained in Production Example 1 in which water was removed by vacuum drying for an hour was added. Further, 10 ml of a chloroprene monomer purified by a conventional method was dissolved in this toluene mixed solution, the inside of the polymerization tube was replaced with nitrogen, and then polymerization was started at 60 ° C. After performing a polymerization reaction for 6 hours, the reaction mixture was poured into methanol to collect the polymer. Soxhlet extraction was carried out for 24 hours with benzene on the monomers and homopolymers remaining in the obtained polymer. After drying under reduced pressure, the amount of the polymer obtained was about 55 g.
(Protein / synthetic polymer complex).

Example 1 30 g of an esterified product of gelatin / allyl alcohol (esterified gelatin) obtained in Production Example 1 and a particle size of 150 μm
Polystyrene resin powder (trade name: "Vitax V"
After thoroughly mixing 70 g of "-6702A" manufactured by Hitachi Chemical Co., Ltd.), a polypropylene non-woven fabric (trade name "Tafnel PA-"
4021 "manufactured by Mitsui Petrochemical Co., Ltd., weight 100 per 1 m ²
g) Dispersed evenly over 1 m ² . Then, it was heated to 120 ° C. to melt the polystyrene resin powder and fuse it to a non-woven fabric to obtain synthetic leather. Its surface was leather-like, and its moisturizing properties, breathability, and touch were similar to those of natural leather.

Examples 2 to 9 By the same method as in Example 1, a mixture of the esterified product or protein derivative of the protein shown in Table 1 and the thermoplastic resin powder was sprinkled on 1 m ² of non-woven fabric or woven fabric, and then heated by heating. The synthetic resin powder was melted and fused to a non-woven fabric or a woven fabric to obtain a synthetic leather. The surface of each of the obtained synthetic leathers was leather-like, and the moisturizing properties and breathability were similar to those of natural leathers.

[0034]

[Table 1]

Examples 10 to 12 By the same method as in Example 1, a mixture of the esterified product of the protein shown in Table 2 and the thermoplastic resin powder was formed to a thickness of 3 m.
It was sprayed on a urethane resin foam having an area of m and an area of 1 m ² and then the thermoplastic resin powder was melted by heating and fused to obtain a synthetic leather. The surface of each of the obtained synthetic leathers was leather-like, and their moisturizing properties, breathability, and touch were similar to those of natural leathers.

[0036]

[Table 2]

Example 13 30 g of the esterified product of gelatin / allyl alcohol (esterified gelatin) obtained in Production Example 1 and 70 g of polystyrene resin powder (trade name: "Vitax V-6702A" manufactured by Hitachi Chemical Co., Ltd.) were added to dimethyl sulfoxide. After dissolving in 1 kg, a urethane resin foam with a thickness of 3 mm and an area of 1 m ² (trade name “Clara Foam KM-54” manufactured by Kurabo Industries)
Applied on top. After evaporating dimethylsulfoxide by drying at room temperature, it was heated to 120 ° C., and a mixture of esterified gelatin and polystyrene was attached to the urethane resin foam,
It was 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.

[0038]

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, a synthetic leather having moisturizing properties, breathability, touch feeling and the like similar to natural leather can be obtained.

Claims (9)

[Claims] 1. A. A functional group derived from a polyfunctional alcohol present in the esterified product of a protein in which a protein and a polyfunctional alcohol are reacted to perform esterification, and the carboxyl group of the protein side chain is chain-extended, or the esterified product side chain of the protein. The resin composition for synthetic leather, which comprises 5 to 80% by weight of a protein derivative and B: 95 to 20% by weight of a thermoplastic resin. 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. A functional group derived from a polyfunctional alcohol present in the esterified product of a protein in which a protein and a polyfunctional alcohol are reacted to perform esterification, and the carboxyl group of the protein side chain is chain-extended, or the esterified product side chain of the protein. Is further reacted with 5 to 80% by weight of a protein derivative and B: 95 to 20% by weight of a thermoplastic resin, and the composition is applied or sprayed on at least one side of a non-woven fabric or a woven fabric of natural fibers or synthetic fibers. Later, synthetic leather obtained by 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. A functional group derived from a polyfunctional alcohol present in the esterified product of a protein in which a protein and a polyfunctional alcohol are reacted to perform esterification, and the carboxyl group of the protein side chain is chain-extended, or the esterified product side chain of the protein. Is further reacted to obtain a protein derivative: 5 to 80% by weight, and B: a thermoplastic resin: 95 to 20% by weight. The synthetic leather obtained. 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.