JPH0482974A - Highly moisture-permeable synthetic leather - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field 1] The present invention relates to highly moisture permeable synthetic leather, and more specifically, the surface has a texture rich in the feel of natural skin, and has moisture permeability, hygroscopicity, and release properties. This invention relates to synthetic leather that has functionality such as moisture resistance.

[Prior Art] Since synthetic leather first appeared as a substitute for natural leather, numerous improvements have been proposed, and it has now become an indispensable material for uses such as shoes, balls, and clothing.

However, in these applications, people often use the product in direct contact with the skin, and when it comes into contact with the skin, it has a surface that does not feel uncomfortable, does not feel sticky due to sweat, and
Synthetic leather with high moisture permeability, high moisture absorption, and high moisture release properties has been desired. At present, there is no product that satisfies all of these requirements, but recent measures include polyurethane with parent wood groups, polyurethane with leather powder dispersed, silicone-modified polyurethane, or polyamino acid urethane. Synthetic leather formed as a membrane has been proposed. However, these methods
The current situation is that it is not satisfactory in practical terms. For example, synthetic leather with hydrophilic group-introduced polyurethane or silicone-modified polyurethane formed as a surface film has increased moisture permeability, but has the sticky feeling characteristic of polyurethane, especially when it comes in contact with sweaty skin. is not desirable because it is large. In order to improve this problem, synthetic leather has been proposed that has a surface film made by dispersing leather powder in polyurethane, but since the leather powder contains metals, self-painting is unsuitable because the coloring is too thick. However, if the content of leather powder is too high, functionality such as surface feel and moisture permeability will be satisfied.
It has some drawbacks such as low film strength and leather powder falling off from the surface film when rubbed, so it is not satisfactory.

As described above, there is still no satisfactory product at present, and the demand for synthetic leather as a new material having these functions is increasing from various application fields.

[Objective of the Invention] The object of the present invention is to solve the problems that are not satisfied with these conventional methods, to have a surface texture that is similar to human skin, and to have functionality such as moisture permeability, moisture absorption, and moisture release. Our goal is to offer superior synthetic leather to customers.

[Configuration and Effects of the Invention] In other words, the present invention provides a coating in which particles made of natural collagen are dispersed in a synthetic resin mainly composed of polyamino acid urethane resin, on the surface of a synthetic leather base made of fibrous synthetic resin. It is a synthetic leather characterized by the fact that it has been formed. The synthetic leather substrate used in the present invention is composed of a fibrous material, and the fibers are conventionally known synthetic fibers, regenerated fibers, nonwoven fabrics made of natural fibers, silk fabrics, woven fabrics, etc. The choice is made based on its characteristics, depending on the intended use. Next, as the synthetic resin that is combined with these fibers to form the synthetic leather base, conventionally known polymers can be used, such as polyurethane resin, vinyl chloride resin, vinyl chloride-polyurethane copolymer, SBR, etc. Resin, NBR
Examples include resin. A synthetic leather base is formed from these fibers and a synthetic resin, or the synthetic leather base is a type in which the fiber is impregnated with a synthetic resin, a type in which a synthetic resin is further formed on the surface of this impregnated base, A type with synthetic resin formed on the fibrous surface can be used.

These synthetic resins are composited with fibers by a conventionally known molding method. That is, the conventionally known wet method from a solution such as N,N-dimethylformamide, the dry method from a methyl ethyl ketone solution, the wet method from an aqueous emulsion,
It is made into a porous composite using a dry method. Naturally, non-porous composites can also be adopted.

The polyamino acid urethane of the present invention formed on the surface of such a synthetic leather substrate is a copolymer of polyurethane and polyamino acid, and conventionally known polyamino acid urethanes can be used. A general method for producing polyamino acid urethane is to add N-carboxy-α- to polyurethane.
There is a method of addition polymerizing amino acid anhydrides. As the polyurethane used here, all conventionally known polyurethanes can be used. For example, polyurethane obtained by reacting an organic diisocyanate with a long-chain diol and a chain extender is typical.As the organic diisocyanate, alicyclic organic diisocyanates, aliphatic organic diisocyanates, aromatic organic diisocyanates, etc. can be used. As long-chain diols, polyester diols, polyether diols, polyamide ester diols, polycarbonate diols, etc. can be used, and as chain extenders, active agents such as low-molecular glycols, low-molecular diamines, and low-molecular amino alcohols can be used. A compound containing two hydrogen atoms can be used, and a polyurethane composed of a mixture thereof may also be used. These raw materials should be selected depending on the application. For example, in applications where hydrolysis resistance and discoloration resistance are required, alicyclic diisocyanates or aliphatic diisocyanates may be used as the organic diisocyanate. As the long-chain diol used, polycarbonate diol or polyether diol may be used. Examples of the N-carboxy-α-amino acid anhydride to be added to the above polyurethane include the anhydride of γ-methyl monoglutamate, or the anhydride of ethyl, propyl, and butyl esters of carboxylic acid at the γ-position. , or the anhydride of leucine. The polyamino acid segment ratio in the polyamino acid urethane obtained by these reactions is 3% by weight ~
85% by weight, preferably 10% to 60% by weight. The polyamino acid segment ratio is 3% by weight
If the coating does not have grooves, the synthetic polyamino acid particles may fall off from the coating film, or the functional properties such as moisture permeability may not be satisfactory, which is not preferable because the present invention cannot be satisfied. Furthermore, if the polyamino acid segment 1 ratio exceeds 85% by weight, the elongation of the obtained coating film will be low and the mechanical strength against bending, rolling, etc. will be reduced, which is not preferable. The polyamino acid urethane thus obtained is used as an organic solvent solution. Organic solvents for dissolving polyamino acid urethane include chlorinated aliphatic hydrocarbons such as methylene chloride, chloroform, and 2-dichloroethane, but they are difficult to dissolve when the polyamino acid segment ratio in polyamino acid urethane is high. In addition, from the viewpoint of handling with hygiene in mind,
It is better to avoid it as much as possible. Preferred organic solvents include:
Dioxane, N,N-dimethylpolamide, N,N-
Polar organic solvents include dimethylacetamide, N-methylpyrrolidone, methylethylketone, and tetrahydrofuran. When the organic solvent used is such a polar organic solvent, if the ratio of amino acid segments in polyamino acid urethane is 40% or more, - it tends to not dissolve between the shells and form a translucent gel-like substance. Therefore, the amino acid segment ratio should be designed in consideration of the type of organic solvent used, the concentration used, etc. In the present invention, other synthetic resins or natural resins are mixed and dissolved in the thus obtained organic solvent solution of polyamino acid urethane in order to modify the properties of the obtained surface film. be able to. In this case as well, naturally, the polyamino acid segment ratio in the mixed resin is preferably 3% by weight to 85% by weight. The particles made of natural collagen dispersed in the synthetic resin mainly composed of polyamino acid urethane are particles obtained from animal skin, hair, bone, etc. through various treatments. For example, currently produced industrially, there are leather powders that are made by grinding so-called leathers that have been treated with chromium at low temperatures, or leather that has not been treated with chrome. There is particulate collagen that is purified by removing excess components other than collagen such as fat through an enzymatic decomposition reaction from skin, hair, bones, etc. In the present invention, any of the above can be used, but it is preferable to use the latter particles, which are purified from skin, hair, bone, etc. that are not coated with chrome, in view of coloring or discoloration of the particles. In other words, the particles crushed from the former chrome-treated leather are colored in chrome, so it is difficult to use them for light colors such as white, and when used, Due to impurities such as fat, it tends to discolor when exposed to light. On the other hand, collagen particles purified through biochemical reaction treatment without chromium are colorless (white) particles, so they can be used for white purposes, and they do not contain impurities such as fat. , there is almost no discoloration due to light, etc., which is preferable. However, collagen purified through biochemical reaction treatment has high swellability in water and is easily degraded by proteolytic enzymes such as amylase, so collagen has been molecularly crosslinked through chemical reactions. It is preferable that there be. In some cases, the particles made of natural collagen as described above are subjected to a treatment such as pulverization to make them even finer particles. The smaller the particle system, the larger the particle surface area per unit weight, which makes it easier to obtain functional properties such as moisture permeability, moisture absorption, and moisture release properties of the resulting coating film, and furthermore, the surface texture of the coating film becomes smoother. preferable. The average particle size of the particles is preferably 20 μm or less,
More preferably, it is 10 μm or less. The particles made of natural collagen thus obtained are added and dispersed in the above-described organic solvent solution of polyamino acid urethane, and used as a surface forming film of a synthetic leather substrate, which is the object of the present invention. .

The surface-forming film obtained from particles consisting of a resin mainly composed of polyamino acid urethane and natural collagen is an amino acid urethane with excellent mechanical strength that has high elongation even when mechanical forces such as bending and kneading are applied. Because the polyamino acid segment and natural collagen particles have an affinity due to the same protein molecular structure, there is no whitening or shedding of particles made of natural collagen. Therefore, the amount of particles made of natural collagen to be added to polyamino acid urethane (solid) can be selected over a wide range. The amount of polyamino acid segments in the particles consisting of polyamino acid urethane and natural collagen, which is a polyamino acid, in the whole solid content greatly affects the surface feel and functional properties of the resulting surface-forming film. By increasing the amount of particles added, a surface-formed film with a large amount of polyamino acid segments and rich in functional properties can be obtained. That is, when particles made of natural collagen are used in combination with other synthetic resins such as polyurethane without using polyamino acid urethane, there is a limit to the amount of particles added in order to prevent the particles from falling off. On the other hand, since the amount of polyamino acid segments in the surface film is relatively reduced, a surface film rich in the functional properties targeted by the present invention can be obtained.

In addition, when a surface film consisting only of polyamino acid urethane has a high polyamino acid segment ratio, a coating film rich in functionality, which is the objective of the present invention, can be obtained, but the elongation is low. Mechanical durability such as bending is poor, and the object of the present invention cannot be achieved. As described above, the present invention is characterized by a synthetic leather having a highly functional surface film with a high ratio of polyamino acid segments consisting of molecular polyamino acid segments and particulate polyamino acid segments. It also has excellent mechanical strength. The total weight of the polyamino acid segment in the polyamino acid urethane constituting the surface film of the present invention and the particles made of natural collagen, which is a polyamino acid, is 20% of the total solid content.
It is preferably 40% by weight or more, more preferably 40% by weight.
That's all. However, these values are not intended to limit the invention.

In some cases, a coloring agent such as a pigment or a dye may be added to the surface film thus obtained to enhance the cosmetic properties of the resulting coating film. Further, antioxidants, NOx gas discoloration inhibitors, various deterioration inhibitors, and the like can also be added in order to obtain a good surface film.

The surface film obtained as described above is formed on the surface of the synthetic leather substrate. Spray coating,
Conventionally known methods such as gravure coating, knife coating, roll coating, and lamination using release paper can be employed. Depending on these application methods, the concentration may be adjusted to achieve the optimum viscosity. If the coating thickness is insufficient with one application, repeat application and drying.
Just adjust it to the target coating thickness. The synthetic leather thus obtained has a surface feel that does not feel uncomfortable when a person comes into direct contact with the skin, does not feel sticky due to sweat, and
It has high moisture permeability, high moisture absorption, and high moisture release properties, and is strong enough to prevent powder from falling off even when rubbed. Furthermore, in order to enhance these functional effects, for example, when designing an upper material for shoes, a base fabric such as rayon or cotton with high hygroscopicity is used as the fiber material constituting the synthetic leather base, and the surface of the present invention is used as a synthetic resin. Particles made of polyamino acid urethane and natural collagen that form a membrane may be used. That is, by absorbing sweat emanating from the feet from the highly hygroscopic back surface and dissipating it to the outside through the surface film having excellent moisture permeability and moisture release properties, shoes that do not make the feet feel stuffy can be made. Thus, depending on the application, the present invention can
By appropriately selecting the materials constituting the present invention, even greater effects can be brought about.

[Examples] Hereinafter, the present invention will be specifically explained in detail with reference to Examples. In the examples, "parts" and "%" are all based on weight, and the measured characteristic values were obtained by the following method.

(a) Moisture permeability It is expressed as water vapor permeability (87 m2・day) according to JIS L1099 A-1 method.

(b) Moisture absorption It is expressed as a moisture absorption landscape (87 m2) when the sample was left in an atmosphere with a temperature of 23°C and a relative humidity of 30% for 1 hour, and then left in an atmosphere with a temperature of 23°C and a relative humidity of 80% for 30 minutes.

(c) Humidity release Expressed as the amount of moisture released (87 m2) when the sample was left in an atmosphere with a temperature of 23°C and a relative humidity of 80% for 1 hour, and then left in an atmosphere with a temperature of 23°C and a relative humidity of 30% for 30 minutes.

(d) Flexibility: expressed in grades 1 to 5 according to the JIS K6545 method.

Example-1 (Creation of synthetic leather base-1) An impregnated base material was prepared by impregnating a nonwoven fabric made of polyester fibers with a weight of 280 g/m2 and a thickness of 1.01111 with a 13% concentration polyester polyurethane-dimethylformamide solution. The surface was coated with a 18% polyester polyurethane-dimethylformamide solution with a basis weight of 600 g/m2, followed by water immersion coagulation, washing, and drying to prepare a synthetic leather base.

(Creation of paint-1) Paint-1 was prepared with the following composition.

Crisbon NY320 100 parts (manufactured by Dainippon Ink & Chemicals) Hauluck A1003 White 80 parts (manufactured by Dainippon Ink & Chemicals) Hauluck A1008 Matte 30 parts (manufactured by Dainippon Ink & Chemicals) Isopropyl alcohol 50 parts Methyl ethyl getone 40 parts N,N-dimethylformamide 10 parts (preparation of paint-2) Polyamino acid urethane (non-yellowing type urethane used: Seiko Kasei ■ LUCKSK INUA-3295A
, polyamino acid segment (35%) dissolved in N,N-dimethylformamide (solid content 10%) in 100 parts, particles made of chromium-free natural collagen (manufactured by Showa Denko ■; CX260; average particle size 7 μm) were added. 5 parts were added, mixed and dispersed to prepare a stable dispersion. In this, there is a matting agent (
Manufactured by Dainippon Ink &Chemicals; Hauluck B1356) 1
5 parts were added and mixed uniformly to obtain a dispersion paint.

(Application on the synthetic leather surface) Paint-1 was gravure coated on the surface of the synthetic leather base-1 prepared earlier (using a roll of 110 mesh).
After repeating coating and drying three times, and then applying a pattern with a heated embossing roll, paint-2 was applied with gravure coating I! (using a roll of 110 mesh), repeat coating and drying three times,
A synthetic leather with a white surface was obtained. The surface of the obtained synthetic leather does not feel cold when it comes in contact with the skin, but gives a feeling of warmth, and has an excellent texture without stickiness even on sweaty skin, making it suitable for use in volleyball and handball. It was excellent. It also has greater moisture permeability than conventional synthetic leather, making it an excellent material for the uppers of sports shoes.

The obtained characteristic values are shown in Table 1.

Example-2 (Creation of paint-3) Create paint-3 with the composition below.

LUCKSKIN-UA3295A 100 parts (Seiko Kasei ■) (18%) Natural collagen particles CX-26010 parts (Showa Denko ■
Dailac 5L-3440 Red 5 parts (manufactured by Dainippon Ink & Chemicals) N,N-dimethylformamide 40 parts Methyl ethyl ketone 40 parts (application on the surface of synthetic leather) Synthetic leather prepared from Paint-3 in Example-1 Gravure coating machine (using 110 mesh roll) on the surface of base-1
The coating and drying process was repeated three times, and then patterned using a heated embossing roll to obtain synthetic leather with a red coating on the surface. The surface of the resulting synthetic leather does not make you feel cold when it comes in contact with your skin, but gives you a sense of warmth.It has an excellent texture and does not feel sticky even on sweaty skin, and is suitable for basketball, rugby, etc. It was excellent for balls. The obtained characteristic values are shown in Table 1.

Example-3 (Preparation and application of paint-4) N,N-dimethylformamide of polyamino acid urethane (R yellowing type urethane toilet: Mitsubishi Kasei ■ PAU-300: 1 polyamide acid segment) A stable dispersion was prepared by adding, mixing and dispersing 8 parts of natural collagen particles (manufactured by Showa Denko Corporation; CX-260, average particle size 7 μm) into 100 parts of the solution (solid content 15%). In this, 8 parts of black pigment (manufactured by Dainippon Ink & Chemicals, Ltd.; TAIRAK 5L-34, 30) as a coloring agent, and 8 parts of black dye (Nippon Kayaku Oki Kayaset BLACK-KR,
3 parts were added and mixed uniformly to obtain a black paint. This black paint was applied to a patterned release paper so that it had a basis weight of 70 g/m2, and after drying, the adhesive was applied so that it had a basis weight of 50 g/m2 to create the product in Example-1. Attach the surfaces of the synthetic leather base-1 and adhere thoroughly. When the surface of the synthetic leather separated from the release paper comes in contact with the skin, it does not feel cold but feels warm, and even on sweaty skin it does not feel sticky and has an excellent texture. It was suitable for racket clips, glove flat tops, etc. The obtained characteristic values are shown in Table 1.

Example-4 (Creation of synthetic leather base-2) Weight: 280 g/m2, thickness: 1. A mixed polymer of polycarbonate polyurethane and polyamino acid urethane (mixing ratio 60:
40) in N,N-dimethylformamide (concentration 1
0%) and particles made of natural collagen (manufactured by Showa Denko ■,
CX-260. A mixed polymer of polycarbonate-based polyurethane and polyamino acid urethane was added to the surface of the impregnated base material, which had been impregnated with a stable dispersion prepared by adding and dispersing 5 parts (average particle size 7 μm) of N, N- at a mixing ratio of 60:40). Particles made of natural collagen (manufactured by Showa Denko; CX-260; average particle size 7μ) were added to dimethylformamide solution (concentration 18%).
m) Add 10 parts and mix and disperse to make 600g of stable dispersion.
After coating with a basis weight of /m2, water immersion coagulation, water washing,
After drying, a synthetic leather base was created.

(Application on the surface of synthetic leather) Coating-1 prepared in Example-1 was applied to the surface of synthetic leather base-2 using a Clavia coating machine (using a roll of 110 mesh), and the coating and drying process was repeated three times, and then After applying the pattern with a heated embossing roll, paint 2 is applied using a gravure coating machine (110
The coating and drying process was repeated three times using a mesh roll (using a mesh roll) to obtain synthetic leather with a white surface. The surface of the obtained synthetic leather had an excellent surface feel as in Example 1, but its moisture permeability, moisture absorption, and moisture release properties were even more distinctive, and it could be used as an upper material for sports shoes. It was excellent and did not feel stuffy when worn. Table 1 shows the characteristic values obtained.

Example-5 (Creation of synthetic leather base-3) The synthetic leather of Example-4 was made using a nonwoven fabric made of polyester fiber and rayon fiber (mixing ratio 30:70) with a weight of 280 g/m2 and a thickness of 1.0 ml1. Synthetic leather base-3 was created in the same manner using the same synthetic resin as the base.

(Application to the surface of synthetic leather) Clavia coating of paint-3 prepared in Example-2 was applied to the surface of synthetic leather base-3. The coating and drying process was repeated three times (using a 110 mesh roll), and a pattern was added using a heated embossing roll to obtain synthetic leather having a red coating on the surface. The surface of the obtained synthetic leather has an excellent surface texture as in Example-2, but its moisture permeability, moisture absorption, and moisture release properties are even more distinctive, making it ideal for shoes and upper materials. Met. The first characteristic value that cannot be obtained is
Shown in the table.

Example-6 Paint-4 prepared in Example-3 on the surface of nylon taffeta
was applied to a basis weight of 70 g/m2 and dried. The obtained product had high moisture permeability and was comfortable to the touch, making it ideal for sports clothing. The obtained characteristic value is the first
Shown in the table.

Comparative example-1 (Creation of paint-5) Paint-5 was prepared with the following composition.

Howlac A3454 (20%) 100 parts (manufactured by Dainippon Ink & Chemicals ■) Natural collagen particles CX-2601, 0 parts (manufactured by Showa Denko ■) Howlac A 1. OO8 Pine 1 to 30 parts (manufactured by Dainippon Ink & Chemicals) Isopropyl alcohol 50 parts Methyl ethyl ketone 50 parts (application to the surface of synthetic leather) Paint-1 was prepared in Example-1 using a gravure roll (110 mesh) Applied to the surface of artificial leather base-1
After repeating the drying process three times, a pattern is applied using a heated embossing roll, and then paint-5 is applied to the surface using a gravure roll (1
The coating and drying process was repeated three times (10 meshes) to obtain synthetic leather with a white surface. The resulting synthetic leather had unsatisfactory moisture permeability, and when subjected to a bending test, powder that appeared to be CTC-260 particles made of natural collagen fell off. The obtained characteristic values are shown in Table 1.

Comparative example-2 (Creation of paint-6) Paint-6 was prepared with the following composition.

1,, UCK SKI N-U
A 3 2 9 5 A 1. OO
Part (manufactured by Seiko Kasei ■) (18%) Howlac 81356 Matte 20 parts (manufactured by Dainippon Ink & Chemicals ■) N,N-dimethylformamide 40 parts Methyl ethyl ketone 40 parts (application on the surface of synthetic leather) Apply paint-1 to a gravure roll (110 mesh), applied to the surface of the artificial leather base-1 prepared in Example-1.
After repeating the drying process three times, a pattern is applied using a heated embossing roll, and then paint-6 is applied to the surface using a gravure roll (1
Repeat coating and drying three times using 10 meshes to obtain synthetic leather with a white surface. The resulting synthetic leather had unsatisfactory moisture permeability, and the surface had a slightly sticky feel to the touch. The obtained characteristic values are shown in Table 1.

Comparative example-3 (Creation of paint-7) Paint-7 was prepared with the following composition.

Howlac A3454 (20%) 100 parts (manufactured by Dainippon Ink & Chemicals) Hauluck A1008 Pine 1 to 30 parts (manufactured by Dainippon Ink & Chemicals) Isopropyl alcohol 50 parts Methyl ethyl ketone 50 parts (application to synthetic leather surface) Paint - 1 was applied to the surface of the synthetic leather base-1 prepared in Example-1 using a gravure roll (110 mesh).
After repeating the drying process three times, a pattern is applied using a heated embossing roll, and paint-7 is applied to the surface using a gravure roll (1
The coating and drying process was repeated three times (10 meshes) to obtain synthetic leather with a white surface. The resulting synthetic leather has unsatisfactory moisture permeability, and the surface texture is sticky, which is typical of polyurethane in conventional synthetic leather, and it feels particularly sticky and sticky when touched with sweaty skin. It's something I feel. The obtained characteristic values are shown in Table 1.

Table (2) In the above table, the overall rating of 1 to tightness on sweaty skin is based on the following.

◎)・Very good with no luck ○ Good without sticky feeling △ Slightly sticky feeling, but good × It has a sticky feel and is not good. Patent issuer Teijin Cordley Co., Ltd.

Claims (5)

[Claims] (1) High transparency characterized by forming a coating on the surface of a synthetic leather base made of fibers and synthetic resin, in which particles made of natural collagen are dispersed in a synthetic resin mainly made of polyamino acid urethane resin. Moisture synthetic leather. (2) The polyamino acid urethane resin is a polyamino acid segment whose main component is poly-γ-methyl-L-glutamate, and the content thereof is 3% to 85% by weight based on the weight of the polyamino acid urethane resin. Certain claims (1)
synthetic leather. (3) The synthetic leather according to claim 1 or claim 2, wherein the particles made of natural collagen are purified by biochemical treatment from animal skin or the like, and are thermally chemically crosslinked particles. (4) Claim (1) wherein the synthetic resin constituting the synthetic leather base is a synthetic resin mainly composed of polyamino acid urethane resin.
Synthetic leather according to any one of ) to (3). (5) The synthetic resin constituting the synthetic leather base is obtained by dispersing particles of natural collagen in a synthetic resin mainly composed of polyamino acid urethane resin.
Synthetic leather according to any one of (4).