JPH0617378A - Synthetic leather and its production - Google Patents

Abstract

PURPOSE:To obtain a synthetic leather using a polyurethane resin on the surface skin layer, exhibiting moisture permeability, hygroscopic property and dry touch surface properties and simultaneously having suppressed surface glass with high-grade feeling and having fine and deep crepe pattern close to natural leather and its production method. CONSTITUTION:A surface layer 3 consisting of a polyurethane resin containing collagen fine powder 4 is laminated onto a substrate consisting of integrated laminate of a fibrous base material 1 and a wet fine porous layer 2 and the integrated laminate is subjected to rubbing treatment. At this time, water content is added to the integrated laminate and the integrated laminate containing water content may be subjected to rubbing treatment. As the collagen fine powder 4, powder having 20mum or smaller particle diameter is used and the content of the fine powder 4 is 1-100wt.%. Water content of the integrated laminate in rubbing treatment is 30-150% and the temperature is 70-100 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic leather which uses a polyurethane resin for its skin layer.

[0002]

2. Description of the Related Art Conventionally, synthetic leather is manufactured, for example, as follows. First, a hydrophilic organic solvent solution of polyurethane resin is applied to a base material made of woven cloth, knitted cloth, non-woven cloth or the like. Then, it is immersed in water to dissolve and remove the hydrophilic organic solvent in the solution, and the polyurethane resin is solidified to form a wet microporous layer of the polyurethane resin. Then, a skin layer of polyurethane resin is formed on the surface of the microporous layer.

Conventionally, in order to impart a natural leather-like appearance, texture, grain pattern, etc. to the synthetic leather produced as described above, (1) the grain pattern attached to the release paper is used for the polyurethane. Transferring to the resin skin layer, so-called “transfer method” (that is, applying a polyurethane resin solution, which is the material of the skin layer, onto release paper, and drying and gelling it, and laminating it on the above-mentioned polyurethane resin wet microporous layer. Then, the release paper is peeled off, and the grain pattern on the release paper is transferred to the skin layer), (2) a method of rubbing while applying heat.
Has been adopted.

However, in the methods (1) and (2), it is considered that the appearance and texture are insufficient, and (3) the polyurethane resin is mixed with a fine powder of a water-soluble polymer compound such as gelatin or natural leather. A method in which a fine powder is used as a skin layer, (4) a skin layer in which a natural leather fine powder is added to a polyurethane resin is formed on a fibrous base material to form a microporous layer of the polyurethane resin. After laminating on a loose wet base, a rubbing treatment while heating or heating in water or in a humidified atmosphere (Japanese Patent Laid-Open No. 127127/1990).
No. 574), etc. have been developed.

According to the above method (3), a material having moisture permeability and hygroscopicity and a dry-touch surface texture can be obtained. According to the method (4), in addition to these characteristics, ,
A product having a deep grain pattern with low surface gloss is obtained. Although these reasons are not always clear, in the method (3), (i) the fine powder of natural leather contains hydrophilicity or water solubility including glue, gelatin, casein, collagen, etc. It is considered that the skin layer containing the fine powder or the water-soluble polymer compound fine powder has moisture permeability and hygroscopicity,
In the method of (4), in addition to (i), (ii) a rubbing treatment carried out in water or in a humidified atmosphere dissolves and removes the fine powder of natural leather in water to form pores on the surface of the epidermis layer. A porous structure, (iii) the fine powder in the epidermis layer swells and causes distortion in the epidermis layer, (iv)
Contraction of the above-mentioned substrate, (v) distortion of the epidermis layer due to swelling of the natural leather fine powder in (iii) above, and (iv)
It is conceivable that wrinkles caused by the rubbing treatment are synergistic with the shrinkage of the base material.

[0006]

The synthetic leather obtained by the above method (4) has a moisture permeability, a hygroscopicity, a dry touch feeling, a deep grain pattern, etc., which are the closest to those of natural leather. However, since the surface glossiness is low, there is a problem in that the depth of color is impaired, and especially in the case of black, the jet-blackness is impaired.

Therefore, the surface glossiness is suppressed as much as possible in order to maintain a sense of quality without impairing the depth of color, especially jet blackness in the case of black, and it has excellent moisture permeability and hygroscopicity in dry touch, and There is a demand for synthetic leather with a deep grain pattern that closely resembles natural leather.

In order to meet such demands, the present inventors previously formed a skin layer by the above-mentioned transfer method using a polyurethane resin containing a fine powder of hydrophilic (water-soluble) collagen. Then, after laminating this on a base material and kneading it in warm water, the surface layer of the microporous structure where the collagen fine powder was eluted and dropped off the skin layer and the fibrous structure structure in which the collagen fine powder was made into fibers I proposed a synthetic leather with a two-layer structure with the inner part of the. This synthetic leather has a microporous structure that provides a reduction in surface glossiness, moisture permeability, hygroscopicity, and a dry touch feeling, and a fibrous structure has a deep hue, especially excellent jet blackness in the case of black, Gives a certain grain pattern.

It is an object of the present invention to provide a synthetic leather which meets the above-mentioned requirements and a method for producing the synthetic leather by a technique different from the previous proposal by the present inventors.

[0010]

Means for Solving the Problems In the process of further studying the above-mentioned previously proposed technique, the present inventors (a)
Even if the rubbing process of the synthetic leather containing the collagen powder is not carried out in warm water, it is possible to obtain a product having characteristics similar to those of natural leather. (B) Moreover, according to such a rubbing process, What is proposed is that the surface part or the inner part of the epidermis layer exhibits different properties, and as a result, a synthetic leather having different textures (however, similar to the texture of natural leather) can be provided, (c ) Furthermore, when performing a rubbing process, it is possible to obtain a synthetic leather with a particularly preferable texture when the object to be processed (the one in which the skin layer is laminated on the base material) is allowed to contain water directly and the process is carried out under heating. I got the knowledge of.

The present invention is based on the above findings,
(I) A synthetic leather in which a skin layer made of a polyurethane resin containing fine collagen powder is laminated on a substrate, and wrinkles are formed on the skin layer by rubbing, and (II) the substrate of (I) A method for producing a synthetic leather as described in (I) is characterized in that a laminate of a skin layer and a skin layer is allowed to contain water, and this is subjected to a kneading process under heating. At this time, the collagen fine powder having a particle size of 20 μm or less is used, and the content of the collagen fine powder is set to 1 to 100% by weight. Also, the water content during kneading is 3
It is also characterized in that the temperature is set to 0 to 150% and the temperature is set to 70 to 100 ° C.

In the present invention, the fine collagen powder contained in the epidermis layer is obtained by crushing collagen. Collagen has a primary structure of a polypeptide, and three molecules of the polypeptide molecule are entangled as a higher order structure. It is an aggregate having a triple helical structure collagen molecule as a unit structure, and as natural protein fibers, vertebrate skin, bone,
There is a large amount in tendons and the like. In particular, it is said that 1/3 of all proteins in mammals are collagen, 90% or more in bones and tendons, and 50% or more in skins.

The fine collagen powder contained in the epidermis layer is
It is desirable to use particles having a particle size of 20 μm or less.
That is, in the method of the present invention, as will be described later, the collagen fine powder is hardly eluted by the rubbing process, and most of it remains in the surface layer of the synthetic leather product, so that the particle size is 20 μm.
This is because if it is larger, the texture of the surface may be rough. The lower limit of the particle size is not particularly limited, but if it is too small, it may not be fibrillated well by rubbing, and the minimum size that can be pulverized by the current pulverization technique of collagen fiber, From the viewpoint of ease of handling and the like, the thickness is preferably 1 μm or more.

The content of the collagen fine powder is 1 to 100.
% By weight, preferably 5 to 50% by weight. If the content of the collagen fine powder is larger than this, the texture of the surface may be rough as in the case where the above-mentioned particle size is too large. This is because the effect of inclusion cannot be obtained.

The polyurethane resin containing the above collagen fine powder is the same as the polyurethane resin constituting the surface layer of conventional synthetic leather, specifically, polyester urethane resin, polyether urethane resin, ester. / Ether-based polyurethane resin, polycarbonate-based urethane resin, polyamino acid / polyurethane copolymer, etc. (either one-pack type or two-pack type may be used) as they are.

The skin layer made of the above constituent materials is formed, for example, by the above-mentioned transfer method or the like. That is,
On the grain pattern attached to the surface of the release paper, a polyurethane resin solution containing the above collagen fine powder (hereinafter, referred to as "skin layer constituent material"), doctor knife, comma doctor, roll coater, gravure coater, Apply by a rotary screen or other appropriate means to dry and gel.

At this time, the skin layer may be a single layer or a plurality of layers. When using multiple layers,
Each layer may be formed of the same material constituting the skin layer (containing the same polyurethane resin and the same proportion of the fine collagen powder having the same particle size), or different materials constituting the skin layer (different or the same polyurethane). It is also possible to form each layer with a resin containing collagen fine powder of the same or different particle size in the same or different ratio).

The skin layer is formed as described above, and this is laminated on the base material. As the base material, similar to the previously proposed synthetic leather, a so-called wet base in which a wet microporous layer of polyurethane resin is integrally formed on a fibrous base material made of woven cloth, knitted cloth, non-woven cloth, etc. Can be used.
Further, instead of the wet microporous layer, a dry foam layer (for example, a polyurethane resin solution containing a foaming agent formed into a sheet and heated and foamed) may be provided. It may have no microporous layer or dry foam layer (that is, only a fibrous base material).

The above-mentioned skin layer is laminated on the substrate by heating and pressing. The heating and pressurizing conditions at this time are different depending on the types of the above-mentioned skin layer constituent materials and the base material, or depending on the thickness of the skin layer and the thickness of the wet microporous layer or the dry foam layer of the base material, etc. However, if the temperature is too low and the pressure is low, a sufficient integration effect cannot be obtained.On the contrary, if the temperature is too high and the pressure is high, the gloss of the release paper is adversely affected, or the thickness of the wet microporous layer is reduced by the softening or the skin layer. In the present invention, 120 to 170 ° C. and 3 to 8 kg / m are generally caused because problems such as disappearance of a grain pattern due to melting of the resin occur.
It is appropriately selected within the range of about ² .

Further, in the present invention, an adhesive layer may be interposed between the base material and the skin layer in the above-mentioned lamination. As this adhesive, a one-component or two-component polyurethane resin adhesive can be preferably used.

In the present invention, the above-mentioned finely divided collagen powder may also be contained in the wet microporous layer, dry foam layer and adhesive layer. The particle size and content of the collagen fine powder at this time may be the same as the particle size and content of the above-mentioned epidermal layer, but the particle size is rather large because it does not lead to a direct contact feeling. However, the effect is not as great as when it is contained in the skin layer. Therefore, the content is preferably set to be slightly low in terms of material cost.

After the skin layer is laminated on the substrate as described above, the release paper is peeled off. Then, a kneading process is performed. It is preferable that this rubbing process is performed by adding water to the laminated integrated product of the base material and the skin layer and heating the mixture by the method of the present invention. At this time, if the water content is too low, the action due to the kneading process described later (such as fibrosis of fine collagen powder or formation of grain pattern) will not be sufficiently exhibited, and conversely if it is too high,
The same action as that of the previously proposed rubbing process in warm water (elution of collagen fine powder) is expressed, and the collagen fine powder from the epidermis layer is eluted. Therefore, in the method of the present invention, it is preferable to set the water content (ratio of the weight of water to the weight of the laminated integrated body of the substrate and the skin layer) to 30 to 150%.

The temperature at the time of kneading when water is contained varies depending on the type of the above-mentioned material for forming the skin layer or the base material, or the thickness of the skin layer or the base material, etc., and cannot be determined unconditionally. However, if it is too low, the action of kneading by adding water (such as fibrosis of fine collagen powder and formation of grain pattern) will not be sufficiently expressed. Conversely, if it is too high, water will evaporate too quickly. Therefore, the same effect as when water is not contained is exhibited. Therefore, according to the method of the present invention, 7
The optimum temperature is selected from the range of 0 to 100 ° C.

Further, the means for kneading is not particularly limited, but as a means for easily carrying out the kneading under the above water content and temperature conditions, a rotary dryer such as a tumbler dryer is used. Is preferably adopted.

When a rotary drying machine is used, the kneading process is not sufficiently performed even if the rotation speed is too fast or too slow. Therefore, in the present invention, the rotation speed is about 20 to 30 rpm / minute. It is preferable. Then, it is preferable to perform rubbing processing for about 30 to 60 minutes at such a rotation speed. This is because if it is less than 30 minutes, sufficient kneading cannot be performed, and even if it is longer than 60 minutes, the action of the kneading is saturated and it becomes uneconomical.

[0026]

According to the present invention, by kneading the laminated integrated product of the base material and the skin layer, an effect different from the previously proposed one is exhibited. That is, the collagen fine powder contained in the epidermis layer hardly elutes and falls off even on the surface part of the epidermis layer, and most of it is fibrillated from the surface part to the inner part of the epidermis layer. At this time, according to the method of the present invention, the kneading process under heating in a state in which the laminated integrated body of the base material and the skin layer contains water has a more remarkable effect.

This situation will be schematically described with reference to the drawings. Before the rubbing process, as shown in FIG. 1 (a), an integrated product of the fibrous substrate 1 and the wet microporous layer 2 (this wet substrate is used). The microporous layer 2 may be a dry foam layer, or both layers may be omitted), and a skin layer 3 containing collagen fine powder 4 uniformly distributed therein is laminated and integrated. . And
After the rubbing process, as shown in FIG. 1 (b), the fine collagen powder is fibrillated 41, and the skin layer 3 has a polyurethane resin as a matrix, and the collagen fiber 41 is provided inside the matrix.
In other words, it has a fiber structure.

The reason why the collagen fine powder 4 is made into fibrous matter 41 is not necessarily clear, but the collagen fine powder 4 which is a lump of fibers is kneaded and loosened to form the fibrous 41.
Presumed to return to.

The skin layer 3 having the structure of the fibrous structure as shown in FIG. 1 (b) does not have fine porosity in the surface portion as in the above-mentioned prior proposal, but is dull to the synthetic leather product. In addition to imparting a deep surface gloss, it also imparts a dry touch feeling, moisture permeability, and hygroscopicity. Although the reason for this is not always clear, the hydrophilic property which is the original property of collagen is not lost even by the fibrosis by the above-mentioned rubbing process, and the hydrophilic property of the hydrophilic collagen fiber 41 is applied to the entire skin layer 3. It is presumed that this is due to the addition of.

Moreover, the skin layer 3 having a fibrous structure as shown in FIG. 1 (b) has a fine grain pattern and a deep depth (these are referred to as "fractal effect") to improve hue and sharpness. It also contributes to a natural matt effect (effect of reducing the surface glossiness), and particularly imparts excellent jet blackness in the case of black. It is presumed that the reason for this is that the fibrous base material 1 shrinks under heat and humidity, while the hydrophilic collagen fibers swell to cause distortion in the epidermis layer 3, and wrinkles due to the rubbing process are synergized with these. .

However, in the present invention, since fine pores are not formed on the surface portion of the skin layer 3 unlike the above-mentioned proposal,
Provided is a synthetic leather which has a slightly different texture (similar to the texture of natural leather, of course) from the previously proposed synthetic leather in terms of surface gloss, dry touch, texture pattern, and the like.

Further, in the method of the present invention, the wet microporous layer, the dry foam layer or the adhesive layer may contain fine collagen powder, and in this case, collagen fiber is formed also in these layers. As a result, moisture permeability and hygroscopicity are imparted, the fractal effect described above is further improved, and the grain pattern is formed with a greater depth, and it goes without saying that the structure is infinitely similar to natural leather.

[0033]

EXAMPLES Specific examples and comparative examples of the present invention will be given with reference to FIGS. 1 (a) and 1 (b).

Example 1 Rayon woven fabric 1 having a thickness of 0.5 mm, one side of which is rough-raised
20% / cm ^{2 of} 100% Mogellas on the rough brushed surface of
12% by weight of polyester-based polyurethane resin DMF
(Dimethylformamide) solution with a basis weight of 700 g
/ M ² and then the solvent was removed in water at 20 ° C. to solidify the polyurethane resin. After this, dehydrate,
It was dried under hot air at 120 ° C. to obtain a substrate having a wet microporous layer 2 having a thickness of 0.65 mm.

On the other hand, 40% by weight of collagen fine powder 4 having an average particle size of 9 μm is contained on the surface of the release paper with a grain 10.
20% by weight DMF-MEK (methyl ethyl ketone) equal volume mixed solution of a polyester-based polyurethane resin having a 0% modulus of 60 kg / cm ² (containing 20 parts by weight of a black colorant per 100 parts by weight of the polyurethane resin), the thickness when dried To have a thickness of 25 μm with a knife coater and dried at 90 ° C. for 2 minutes to form a skin layer 3.

While heating the surface of the microporous layer 2 of the substrate on which the wet microporous layer 2 is formed and integrated on the upper surface of the skin layer 3, heat is applied at a temperature of 140 ° C. and a pressure of 4 kg / m ^2. After pressure bonding and lamination, the release paper was peeled off. As a result, a product obtained by laminating and integrating the skin layer 3 made of a polyurethane resin containing the collagen fine powder 4 by the transfer method and the base material was obtained.

Next, water content of the attached integrated product is 1
It is contained at 00% and is tumbler rotary dryer at 90 ° C.
While heating to 50 ° C., it was dried and kneaded for 35 minutes at a rotation speed of 20 rpm / min to obtain a synthetic leather according to the present invention.

Example 2 A synthetic leather according to the present invention was obtained in the same manner as in Example 1 except that no water was added during the rubbing process and no heating was performed.

Example 3 On a raised surface of a polyester / rayon blended woven fabric 1 having a thickness of 0.8 mm and having one side raised, a 100% modulus was 4
1 of 0 kg / cm ² polyester polyurethane resin
A 4 wt% DMF solution was applied so that the basis weight was 850 g / m ^2, and then the solvent was removed in water at 20 ° C. to solidify the polyurethane resin. Then, it was dehydrated and dried under hot air at 130 ° C. to obtain a substrate having a wet microporous layer 2 having a thickness of 0.95 mm.

On the other hand, 100% containing 35% by weight of collagen fine powder having an average particle size of 9 μm on the surface of the release paper with a grain.
20% by weight DMF-MEK mixed solution of 20% by weight of polyester-based polyurethane resin having a% module of 110 kg / cm ² (containing 20 parts by weight of black colorant per 100 parts by weight of polyurethane resin) and having a dry thickness of 15 μm. It was applied with a knife coater as described above and dried at 90 ° C. for 2 minutes to form a first skin layer. Further, on the first epidermis layer, 100% modular gel containing 35% by weight of collagen fine powder having an average particle diameter of 9 μm was 30 kg / c.
20% by weight of polyester-based polyurethane resin of m ² D
MF-MEK equal volume mixed solution (containing 20 parts by weight of black colorant per 100 parts by weight of polyurethane resin) was applied with a knife coater so that the thickness when dried was 20 μm, and dried at 90 ° C. for 2 minutes. Then, the second epidermis layer was formed.

Then, the microporous layer 2 of the base material in which the wet microporous layer 2 is integrally formed on the upper surface of the second skin layer.
While heating the surface, thermocompression bonding was performed at a temperature of 140 ° C. and a pressure of 4 kg / m ² to laminate, and then the release paper was peeled off. As a result, a product obtained by laminating and integrating the skin layer 3 made of a polyurethane resin containing the collagen fine powder 4 by the transfer method and the base material was obtained.

Next, water content of 1 is obtained for the integrated product.
It is contained at 00% and is tumbler rotary dryer at 85 ° C.
While heating to 50 ° C., the mixture was dried and kneaded for 40 minutes at a rotation speed of 25 rpm / min to obtain a synthetic leather according to the present invention.

Example 4 Polyester 0.85 mm thick with one side raised
On the raised surface of the rayon-blended woven fabric 1, a 15% by weight DMF solution of a polycarbonate-based polyurethane resin having a 100% modulus is 40 kg / cm ² , and a basis weight of 900 g / m ^2.
And then the solvent was removed in water at 20 ° C. to solidify the polyurethane resin. After this, dehydration, 130
It was dried under hot air at ℃ to obtain a substrate having a wet microporous layer 2 having a thickness of 1.0 mm.

On the other hand, 100% of 30% by weight of fine collagen powder having an average particle size of 9 μm is contained on the surface of the release paper with wrinkles.
% Modularity of 120 kg / cm ² Polycarbonate-based polyurethane resin 18% by weight DMF-MEK equal volume mixed solution (containing 20 parts by weight of black colorant per 100 parts by weight of polyurethane resin) with a dry thickness of 20 μm. It was applied with a knife coater so that it was dried at 100 ° C. for 2 minutes to form a first skin layer. Further, on the first epidermis layer, 100% modella containing 30% by weight of collagen fine powder having an average particle diameter of 9 μm is 50 k
² g / cm ² of polycarbonate-based polyurethane resin
0 wt% DMF-MEK equal volume mixed solution (containing 20 parts by weight of black colorant per 100 parts by weight of polyurethane resin)
Was applied by a knife coater so that the thickness when dried was 20 μm, and dried at 90 ° C. for 2 minutes to form a second skin layer.

Then, the microporous layer 2 of the base material in which the wet microporous layer 2 is integrally formed on the upper surface of the second skin layer.
While heating the surface, thermocompression bonding was performed at a temperature of 140 ° C. and a pressure of 4 kg / m ² to laminate, and then the release paper was peeled off. As a result, a product obtained by laminating and integrating the skin layer 3 made of a polyurethane resin containing the collagen fine powder 4 by the transfer method and the base material was obtained.

Next, water content of the laminated integrated product is 1
It is contained at 00% and is tumbler rotary dryer at 90 ° C.
While heating to 50 ° C., it was dried and kneaded for 50 minutes at a rotation speed of 25 rpm / min to obtain a synthetic leather according to the present invention.

Comparative Example 1 Comparative synthetic leather was obtained in the same manner as in Example 1, except that the fine collagen powder was not added to the epidermis layer and the rubbing process was not performed.

Comparative Example 2 Comparative synthetic leather was obtained in the same manner as in Example 1 except that the rubbing process was not performed.

Comparative Example 3 Comparative synthetic leather was obtained in the same manner as in Example 1 except that fine collagen powder was not added to the epidermis layer.

Comparative Example 4 Comparative synthetic leather was obtained in the same manner as in Example 2 except that the rubbing process was not performed.

Comparative Example 5 Comparative synthetic leather was obtained in the same manner as in Example 3, except that the fine collagen powder was not added to the epidermis layer.

Performance Test Examples of Synthetic Leather Performances of the synthetic leather according to the present invention and comparative synthetic leather obtained in Examples 1 to 3 and Comparative Examples 1 to 5 (glossiness, jet blackness, depth of diaphragm, moisture permeability) , Hygroscopicity) in the following manner, and the results are shown in Table 1.

Glossiness: light incident angle 75 °, light receiving angle 75
Measured with a specular gloss meter (made by Murakami Color Research Laboratory) having an optical system of ° (unit:%) ・ Jetness, depth of grain: visually determined ・ Moisture vapor transmission: measured according to JIS Z 0208 (unit: g /
m ² · 24hr) · hygroscopic: in comparison with the weight of the atmosphere of temperature 40 ° C. × humidity of 40%, weight increase after leaving for 1 hour in an atmosphere of temperature 40 ° C. × 90% humidity (in%)

[0054]

[Table 1]

[0055]

As described in detail above, according to the present invention,
By rubbing the laminated integrated body of the base material and the skin layer containing the collagen fine powder, the collagen fine powder hardly elutes from the surface portion unlike the case of performing the rubbing process in warm water proposed previously. Since most of them stay in the epidermis layer and become fibrous, the epidermis layer has a structure of a fibrous tissue in which collagen fibers are contained in the matrix polyurethane resin. As a result, the surface texture (that is, extremely similar to natural leather) that is slightly different from that of the previous proposal (that is,
Despite having excellent moisture permeability and hygroscopicity, and suppressed surface glossiness with a high-class feeling, it has excellent jet-blackness, especially in the case of black, and forms the same grain pattern as natural leather due to the fractal effect. It is possible to provide a very good synthetic leather having a texture slightly different from that of the previous proposal. In particular, according to the method of the invention,
The above effect is more remarkably exhibited by performing a rubbing process under heating while the laminated integrated product contains water.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment according to the present invention, in which (a) is a diagram schematically showing a situation in which a base material before rubbing and a skin layer are laminated and integrated, and (b) is a rubbing process. It is a figure which shows the latter situation and is a figure which showed typically the structure of the product synthetic leather by this invention.

[Explanation of symbols]

 1 Fibrous Substrate 2 Wet Microporous Layer 3 Epidermal Layer 4 Collagen Fine Powder 41 Collagen Fiber

Claims (4)

[Claims] 1. Synthetic leather comprising a base material, a skin layer made of a polyurethane resin containing fine collagen powder, and a wrinkle formed by rubbing on the skin layer. 2. A collagen fine powder having a particle size of 20 μm or less is used, and the content of the collagen fine powder is 1.
The synthetic leather according to claim 1, which is -100% by weight. 3. A method for producing synthetic leather, which comprises laminating a skin layer made of a polyurethane resin containing fine collagen powder on a base material, allowing it to contain water, and kneading it under heating. . 4. The method for producing synthetic leather according to claim 3, wherein the water content during rubbing is 30 to 150%, and the temperature is 70 to 100 ° C.