JPS6051592B2 - Artificial leather manufacturing method - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing artificial leather.

More specifically, the present invention is a method for producing artificial leather with excellent adhesion and migration resistance, which is characterized by using a specific colorant and a specific polyurethane resin. Conventionally, a first paint layer made of a mixture of a colorant and a resin is formed on a base layer,
A method for manufacturing artificial leather by forming a second paint layer made of a mixture of a cellulose resin and a coloring agent as a main component on the first paint layer is known. Various resins such as polyurethane resins, acrylic acid resins, and methacrylic acid resins are used as the resin for the first paint layer, and dyes and pigments are used as the colorants for the second paint layer. However, if conventionally used resins are randomly used as the resin for the first paint layer, the adhesion of the resulting artificial leather will not be satisfactory, and dyes may not be used as the coloring agent for the second paint layer. However, the disadvantage of using this method was that the migration resistance was poor.

In addition, if a randomly selected resin is used to form the first paint layer and then a second paint layer is formed, if a pigment is used as a colorant at that time, even if the migration resistance is excellent, the bending resistance is The disadvantage was that the value decreased. As a result of intensive studies in order to provide a method for manufacturing artificial leather free from these drawbacks, the present inventor used an aromatic polyurethane resin containing an acrylic acid resin having a specific modulus as the resin of the first paint layer, It was discovered that by using only pigments as the colorant for the two paint layers, the adhesion between the first paint layer and the second paint layer could be greatly improved, and artificial leather with good migration resistance could be obtained. However, the present invention was achieved.

That is, in the present invention, a first paint layer made of a mixture of a colorant and a resin is formed on a base layer, and a mixture of a colorant and a resin whose main component is a cellulose resin is formed on the first paint layer. When manufacturing artificial leather by forming a second paint layer made of a mixture, the resin of the first paint layer has a modulus of 0.1 to 0.65 at 20% elongation of the film of 9/Tr! lft aromatic polyurethane resin; add 3 to 3 acrylic acid resin
This is a method for producing artificial leather with excellent adhesion and migration resistance, which is characterized by using a resin containing 20% and using a pigment as a coloring agent in the second paint layer.

In the present invention, the base layer refers to nonwoven fabric, woven fabric, or knitted fabric (including those impregnated with resin), or nonwoven fabric, woven fabric, or knitted fabric (including those impregnated with resin) on which a resin layer is formed. It is something that

As the coloring agent used in the first paint layer formed on the top of the base layer, known dyes and pigments are used.

As the pigment, both organic pigments and inorganic pigments can be used. The resin used for the first paint layer is an aromatic polyurethane resin containing 3 to 2% acrylic acid resin by volume, and the modulus of the film at 20% elongation is 0.
．． Must be between 1 and 0.65k9/TI7lt.

Aromatic polyurethane resin is diphenylmethane-4,4
- diisocyanates, triene diisocyanates,
Some are composed of diisocyanates such as phenyl diisocyanates, soft segments such as polyethylene glycol, polytetramethylene glycol, and polyethylene adipate, and chain extenders such as ethylene glycol, hexamethylene glycol, and ethanolamine.

Examples of the acrylic acid resin contained in the aromatic polyester resin include butyl acrylate/methyl methacrylate copolymer, butyl acrylate/methyl acrylate copolymer, methyl methacrylate/styrene copolymer, etc. . The content of these acrylic acid resins is 3 to 2% by weight, preferably 5 to 15% by weight, based on the aromatic monopolyester resin.

If the content of acrylic acid resin is less than 3% by weight,
The adhesion between the first paint layer and the second paint layer deteriorates, resulting in
If the amount exceeds % by weight, the bending resistance will deteriorate. Furthermore, the modulus of a film made of these aromatic polyurethane resins containing an acrylic acid resin at 20% elongation must be within the range of 0.1 to 0.65 k9/i. Modulus at 20% elongation is 0.1kg
/Trrlt, the adhesiveness of the surface to be coated increases, which adversely affects workability during painting and when producing secondary products.

Furthermore, if a resin exceeding 0.65k9/Trllt is used, there is a drawback that the bending resistance deteriorates. The above-mentioned resin, that is, the modulus of the film at 20% elongation is 0.
By using a resin of aromatic polyurethane resin of 1 to 0.65k9/Tl7it containing 3 to 2% of acrylic acid resin as the resin of the first paint layer,
Artificial leather with good adhesion can be obtained.

The first paint layer is formed by applying a polymer solution (including a heterogeneous system) consisting of the pigment or dye described above, the resin described above, and a solvent (containing water) to the base layer and drying it. . In the present invention, a second paint layer is then applied on top of the first paint layer.
Form a paint layer. The cellulose resin used as the main component of the second paint layer has a nitrification degree of 11 to 12, for example. There are nitrocellulose, cellulose acetate, etc. with a weight of %. The coloring agent used in the second paint layer must be a pigment.

Examples of pigments used include benzidine yellow,
Pigments that are compatible with cellulose resins are used, such as organic pigments such as phthalocyanine blue, and inorganic pigments such as carbon black, titanium white, and Bengara. By using such pigments as colorants, artificial leather with excellent migration resistance can be obtained. In addition to the above-mentioned cellulose resin and pigments, the second paint layer contains resins that have good compatibility with cellulose resins, such as polyvinyl acetate resin, polyurethane resin, polyacrylic acid resin, dioctyl phthalate, dibutyl phthalate, tricresyl phosphate, and castor resin. Plasticizers such as oil, coconut oil and palm oil, solvents such as ethyl acetate, butyl acetate and amyl acetate, co-solvents such as ethyl alcohol and butyl alcohol, and diluents such as benzene and toluene can be used in appropriate combinations.

Before or after making the artificial leather obtained by the method of the present invention into any final product such as shoes, bags, etc., a part of the surface layer at the desired location is appropriately removed using an abrasive. It can be made into artificial leather with a desired pattern or color.

In the present invention, the first paint layer on the base layer contains an acrylic acid resin in a specific resin, that is, an aromatic polyurethane resin having a modulus of 0.1 to 0.65 k9/i when the film is stretched by 20%. By using a pigment as a coloring agent in the second paint layer, artificial leather with excellent adhesion and migration resistance can be obtained.

The present invention will be explained below with reference to Examples.

Note that all parts in the examples are based on weight. Example 1 Aromatic polyurethane resin based on diphenylmethane-4,4''-diisocyanate aliphatic polyester was added to the nonwoven fabric layer of a polyester fiber nonwoven fabric in a solid content of 6% of the weight of the nonwoven fabric.
A polyurethane resin having the same composition was coated on the surface of the resulting product with a solid content of 200 y/y to form a porous layer to obtain a base layer.

In this base layer, 13 parts of pigment, diphenylmethane-4,4''
42 parts of diisocyanate aliphatic polyester aromatic polyurethane resin, 5 parts of methyl methacrylate/butyl acrylate copolymer, tetrahydrofuran/dioxane/dimethylformamide (weight mixing ratio 40/40/20)
) A first paint layer was formed by applying a paint consisting of 40 parts to a solid content of 15μ, and then a nitrification degree of 12%.
A second paint layer was formed by applying a paint consisting of 4 parts of nitrocellulose, 15 parts of pigment, 15 parts of dibutyl phthalate, and 5 parts of ethyl acetate so that the solid content was 5 μm thick. When the second paint layer of the thus obtained artificial leather A was polished and abraded, an anti-glare appearance with good polishability was obtained. In addition, 20% of the resin film of the first paint layer
The modulus during elongation was 0.27k9/Wllt. Example 2 Pigment 1 was added to the base layer formed up to the porous layer in Example 1.
5 parts, diphenylmethane-4,4''-diisocyanate aliphatic polyester aromatic polyurethane resin 4 (
2) Apply a paint consisting of 4 parts of methyl methacrylate/styrene copolymer and 41 parts of tetrahydrofuran/dioxane/dimethylformamide (weight mixing ratio 30/40/30) so that the solid content is 15 μm thick. A first paint layer was formed.

Next, 38 parts of nitrocellulose with a degree of nitrification of 12%, 1 part of pigment
0.5 parts, 15 parts of dioctyl phthalate, 1.0 parts of castor oil.
A paint consisting of 5 parts and 35 parts of acetic acid has a solid content of 5 μm.
A second paint layer was formed by applying the following coating to form a second paint layer. In this way, artificial leather B was obtained. The modulus of the resin film of the first paint layer at 20% elongation was 0.36 kg/i. Example 3 Pigment 1 was added to the base layer formed up to the porous layer in Example 1.
3 parts, diphenylmethane-4,4''-diisocyanate aliphatic polyester aromatic polyurethane resin 4?
, 5 parts of methyl acrylate/butyl acrylate, and 5 parts of tetrahydrofuran/dioxane/dimethylformamide (weight mixing ratio 40/40/20) were applied to a solid content of 15 μm thick. A paint layer was formed.

Next, nitrocellulose with a nitrification degree of 12%, pigment 15
part, 5 parts of dioctyl phthalate, 3 parts of ethyl acetate? A second coat of paint was applied so that the solid content was 5μ thick.
A paint layer was formed. In this way, artificial leather C was obtained. The modulus of the resin film of the first paint layer at 20% elongation was 0.27 kg/TrJft. Comparative Example 1 Pigment 2 was added to the base layer formed up to the porous layer in Example 1.
5 parts, diphenylmethane-4,4''-diisocyanate aliphatic polyester aromatic polyurethane resin 44
A paint consisting of 48 parts of tetrahydrofuran/dioxane/dimethylformamide (mixing ratio by weight 40/40/20) was applied so that the solid content was 15 μm thick.
A paint layer was formed, and then a second paint layer, which was the same as that for artificial leather A, was formed.

In this way, artificial leather D was obtained. The modulus of the resin film of the first paint layer at 20% elongation is 0.23k9/
It was Tnlt. Comparative Example 2 In the base layer formed up to the first paint layer in Example 1, 7 parts of metal-containing complex salt dye and nitrocellulose 37 with a nitrification degree of 12% were added.
15 parts of dibutyl phthalate and 4 parts of ethyl acetate was applied to a thickness of 5 μm in solid content.
Artificial leather E was thus obtained by forming a paint layer.

Comparative Example 3 In the base layer j formed up to the porous layer in Example 1, 13 parts of pigment and diphenylmethane-4,4''-diisocyanate aliphatic polyester-based aromatic polyurethane resin 4 were added.
5 parts of tetrahydrofuran/dioxane/dimethylformamide (mixing ratio by weight 40/40/20) 4'5 to form a first coating layer with a solid content of 15 μm; A second paint layer was formed by applying a paint consisting of 7 parts of metal-containing complex dye, 37 parts of nitrocellulose with a degree of nitrification of 12%, 15 parts of dibutyl phthalate, and 41 parts of ethyl acetate so that the solid content was 5 μm thick. did.

In this way, artificial leather F was obtained. In addition, the modulus of the resin film of the first paint layer at 20% elongation is 0.23 kg/
It was Wd. Comparative Example 4 A paint consisting of 125 pigments, 38 parts of nitrocellulose with a degree of nitrification of 12%, 15 parts of dibutite mephthalate, and 35 parts of ethyl acetate was applied to the base layer formed up to the first paint layer in Comparative Example 3, with a solid content of 125 parts. A second paint layer was formed by applying the paint to a thickness of 5p.

In this way, artificial leather G was obtained. Artificial leather A obtained above,
B, C, D, E, F, G bending test (JIS-K65
45-''70), abrasion fastness test (JIS
-0849-''71) The results are shown in Table 1.

Regarding the bending resistance test, 300,000 times at room temperature and -10℃
Two cases of 100,000 cycles were tested.

The abrasion fastness test involves wet abrasion when the sample is wetted with water,
It was measured by dry rubbing when dry. In the bending resistance test, results of grades 1 to 3 indicate that the peeling of the second paint layer is large, and results of grades 4 to 5 indicate excellent bending resistance. In the abrasion fastness test, results of grades 1 to 3 indicate poor migration resistance, and grades 4 to 5 indicate excellent migration resistance. As shown in Table 1, when the resin used in the present invention is not used, when the pigment is not used as a coloring agent in the second paint layer, or when neither the resin nor the pigment used in the present invention is used, the resistance This indicates poor flexibility (adhesion) or migration resistance.

Claims (1)

[Claims] 1. A first paint layer made of a mixture of a colorant and a resin is formed on the base layer, and a second paint layer made of a mixture of a colorant and a resin whose main component is a cellulose resin is formed on the first paint layer. When manufacturing artificial leather by forming a layer, the resin of the first paint layer has a modulus of 0.0 when the film is stretched by 20%.
It is characterized by using a resin containing 3 to 20% by weight of an acrylic acid resin in an aromatic polyurethane resin having a weight of 1 to 0.65 kg/mm^2, and using only a pigment as a coloring agent in the second paint layer. A method for manufacturing artificial leather.