JP2771316B2 - Highly breathable synthetic leather - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to a highly permeable synthetic leather, and more particularly, to a surface having a tactile sensation rich in natural skin feeling,
The present invention relates to a synthetic leather having functionality such as hygroscopicity and moisture release.

[Prior Art] Since its appearance as a substitute for natural leather, synthetic leather has been proposed many improvements, and has now grown into an indispensable material for applications such as shoes, balls, and clothing. However, in these applications, humans often use the skin directly in contact with the skin, have a surface feel that does not cause discomfort when in contact with the skin, there is no stickiness due to sweat, and high moisture permeability, Synthetic leather having high moisture absorption and high moisture release properties has been desired. At present, none of these requirements can be satisfied, but as a recent measure, polyurethane with hydrophilic groups introduced, polyurethane with dispersed leather powder, silicone-modified polyurethane, or polyamino acid urethane has been used as the surface film. Synthetic leather formed has been proposed. However, these methods have not been practically satisfactory. For example, synthetic leather in which a polyurethane or a silicone-modified polyurethane having a hydrophilic group introduced is formed as a surface film has increased moisture permeability, but has a sticky feeling peculiar to polyurethane, particularly a sticky feeling when contacted with sweaty skin. Is not preferable because it is large.
In order to improve this, synthetic leather having a surface film in which leather powder is dispersed in polyurethane has been proposed.However, in the case of a white paint, the coloring is large and unsuitable because the leather powder contains a metal. And if the content of leather powder is too large, the functions such as surface feel and moisture permeability are satisfied, but the film strength is small, and there are disadvantages such as the leather powder falling off from the surface film when rubbed, satisfactory It is not something to be done. As you can see, there is nothing to be satisfied at the moment,
The demand for synthetic leather as a new material having these functions is increasing from various application fields.

[Object of the Invention] The object of the present invention is to solve the problems that are not satisfied by the conventional methods, to have a surface feel that is not uncomfortable with human skin, and to provide functionality such as moisture permeability, moisture absorption, and moisture release. It is to propose an excellent synthetic leather.

[Structure and Effect of the Invention] That is, according to the present invention, a film formed by dispersing synthetic polyamino acid particles in a synthetic resin mainly composed of a polyamino acid urethane resin is formed on the surface of a synthetic leather substrate made of a fibrous synthetic resin. It is a synthetic leather characterized by being hampered. As the fibers constituting the synthetic leather substrate used in the present invention, conventionally known synthetic fibers, regenerated fibers, natural fibers, nonwoven fabrics, knitted fabrics, woven fabrics and the like can be used. A choice is made from Next, as the synthetic resin which is combined with these fibers to constitute the synthetic leather substrate, a conventionally known polymer can be used, for example, a polyurethane resin,
Vinyl chloride resin, vinyl chloride-polyurethane copolymer,
SBR resin, NBR resin and the like. A synthetic leather substrate is formed from these fibers and a synthetic resin. As the synthetic leather substrate, a type in which a synthetic resin is impregnated into a fiber,
A type in which a synthetic resin is further formed on the surface of the impregnated substrate, a type in which a synthetic resin is formed on a fibrous surface, and the like can be used. These synthetic resins are compounded with a fiber by a conventionally known molding method. That is, N, N-dimethylformamide or the like, a conventionally known wet method from a solution such as N, N-dimethylformamide, a conventionally known dry method from a methyl ethyl ketone solution, a conventionally known wet method from an aqueous emulsion, and a porous composite formed by a dry method or the like. . Naturally, nonporous composite 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 urethane can be used. As a general production method of polyamino acid urethane, N-carboxy-α is added to polyurethane.
-There is a method in which an amino acid anhydride is subjected to addition polymerization. As the polyurethane used here, all conventionally known polyurethanes can be used. For example, a polyurethane obtained by reacting an organic diisocyanate with a long-chain diol, and a chain extender is typical.As the organic diisocyanate, an alicyclic organic diisocyanate, an aliphatic organic diisocyanate, an aromatic organic diisocyanate, or the like can be used. As long-chain diols, polyester diols, polyether diols, polyamide ester diols, polycarbonate diols and the like can be used, and as chain extenders, activities of low molecular glycols, low molecular diamines, low molecular amino alcohols and the like can be used. A compound containing two hydrogen atoms can be used, and a polyurethane composed of a mixture of these compounds may be used. Depending on the application, these materials should be selected. For example, in applications where hydrolysis resistance is required and discoloration resistance is required, as the organic diisocyanate, alicyclic diisocyanate,
Alternatively, using an aliphatic diisocyanate, as the long-chain diol, a polycarbonate diol, or
A polyether diol may be used. Examples of the N-carboxy-α-amino acid anhydride to be added to the polyurethane include an anhydride of γ-methyl-L-glutamate or ethyl and propyl of a carboxylic acid at the γ-position.
This anhydride includes butyl ester and the like, or leucine anhydride. The polyamino acid segment ratio in the polyamino acid urethane obtained by these reactions is 3% by weight.
8585% by weight, preferably 10-60% by weight. If the polyamino acid segment ratio is less than 3% by weight, the synthetic polyamino acid particles fall off from the coating film, or the functional properties such as moisture permeability cannot be satisfied. Is not preferred because In addition, the polyamino acid segment ratio,
If the content exceeds 85% by weight, the resulting coating film has low elongation, and the mechanical strength against bending, rubbing and the like is undesirably reduced. The polyamino acid urethane thus obtained is used as an organic solvent solution. Examples of the organic solvent for dissolving the polyamino acid urethane include methylene chloride, chloroform, and chlorinated aliphatic hydrocarbons such as 1,2-dichloroethane, but when the polyurethane segment ratio in the polyamino acid urethane is high, it is difficult to dissolve, Moreover, it is better to avoid as much as possible from the viewpoint of hygiene. Preferred organic solvents include polar organic solvents such as dioxane, N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone, methyl ethyl ketone, and tetrahydrofuran. When the organic solvent used is such a polar organic solvent, when the ratio of the amino acid segments of the polyamino acid urethane is 40% or more, it generally tends to become a translucent gel without being dissolved. Therefore, the amino acid segment ratio should be designed in consideration of the type of organic solvent used, the concentration used, and the like. In the present invention, in the organic solvent solution of the polyamino acid urethane thus obtained, in order to modify the properties of the obtained surface film, another synthetic resin or a natural resin is mixed and used. be able to. Also in this case, it is naturally preferable that the polyamino acid segment ratio in the mixed resin is 3% by weight to 85% by weight. The above-mentioned synthetic polyamino acid particles dispersed and used in the synthetic resin mainly composed of polyamino acid urethane are those described in detail above.
-Carboxy-α-amino acid anhydride is a polymer particle obtained by a method of addition polymerization. Examples of the N-carboxy-α-amino acid anhydride include γ-methyl-L
-Glutamate anhydride, or γ-carboxylic acid ethyl, propyl, butyl ester and other such anhydrides,
Or leucine anhydride. Regarding these polymerization methods, polymer, 30,365 (1973), polymer, 30,3
There are many documents in the past such as 9 (1973) and Polymer, 30, 357 (1973), and polymer particles obtained by these conventionally known methods can be used in the present invention. When a mechanical force such as cutting or crushing is applied to the gel obtained by these reactions, the gel is structurally transformed from α-type to β-type, and the particles are not dissolved. Synthetic polyamino acid particles obtained in this way, in some cases, the more fine particles, the larger the particle surface per unit weight, the resulting synthetic leather moisture permeability, moisture absorption, moisture release, etc. Functional properties are easily obtained, and the synthetic leather has a smooth surface feel, which is preferable. The average particle size of the particles is preferably 20 μm or less, more preferably 10 μm or less. The thus-obtained synthetic polyamino acid particles are added and dispersed in the above-described organic solvent solution of the polyamino acid urethane, and used as the surface-forming film of the synthetic leather substrate as the object of the present invention. The surface-forming film obtained from a resin mainly composed of polyamino acid urethane and synthetic polyamino acid particles has a large elongation even when a mechanical force such as bending or kneading is applied. Since the polyamino acid segment and the synthetic polyamino acid particles have an affinity from the same amino acid molecular structure, neither whitening nor dropping of the synthetic polyamino acid particles occurs. Therefore,
The amount of the synthetic polyamino acid particles added to the polyamino acid urethane (solid) can be widely selected. The amount of the polyamino acid urethane and the polyamino acid segments of the synthetic polyamino acid particles in the total solid content greatly affects the surface texture and functional properties of the resulting surface-forming film. By increasing the number of the polyamino acid segments, a surface-formed film having a large amount of polyamino acid segments and rich in functional characteristics can be obtained. That is, when the synthetic polyamino acid particles are used in combination with another synthetic resin such as polyurethane without using the polyamino acid urethane, the amount of the particles added is limited in order to prevent the particles from falling off. Since the amount of the polyamino acid segment in the surface film is relatively small, it is difficult to obtain a surface film rich in functional properties which is the object of the present invention. In addition, the surface film consisting of only polyamino acid urethane, when the polyamino acid segment ratio is large, although a coating film rich in functionality intended for the present invention is obtained, it becomes a coating film with low elongation, The mechanical durability such as bending is poor, and the object of the present invention cannot be achieved. As described above, a feature of the present invention is a synthetic leather having a highly functional surface film having a large polyamino acid segment ratio, which is composed of a molecular polyamino acid segment and a particulate polyamino acid segment, and has a bending property. Is also excellent in mechanical strength. The weight of the polyamino acid segment in which the polyamino acid segment in the polyamino acid urethane constituting the surface film of the present invention and the synthetic polyamino acid particles are preferably 20% by weight or more based on the total solid content, more preferably 40% by weight or more. % By weight or more. However, these numerical values do not limit the present invention.

In some cases, by adding a coloring agent such as a pigment or a dye to the surface film thus obtained, the cosmetic property of the coating film obtained can be enhanced. Further, an antioxidant, an anti-NOx gas discoloration inhibitor, various deterioration inhibitors, and the like can be added to obtain a good surface film.

The surface film obtained as described above is formed on the surface of the synthetic leather substrate. As the surface forming method, conventionally known methods such as spray coating, gravure coating, knife coating, roll coating, and lamination using release paper can be employed. The concentration may be adjusted so as to obtain an optimum viscosity according to these coating methods. In a single application, if the coating thickness is insufficient, the coating and drying may be repeated to adjust the coating thickness to a target thickness. The synthetic leather thus obtained has a surface feel that is comfortable when a person comes into direct contact with the skin, and there is no stickiness due to sweat,
In addition, it has high moisture permeability, high moisture absorption, and high moisture release, and has high strength so that powder does not fall off even when rubbed. Furthermore, in order to enhance these functional effects, for example, when designing as an upper material for shoes, using a base cloth such as rayon or cotton having high hygroscopicity as a fiber constituting the synthetic leather substrate, and using the present invention as a synthetic resin Polyamino acid urethane and synthetic polyamino acid particles forming a surface film may be used.
That is, by absorbing the sweat diverging from the feet from the back surface having a large hygroscopic property and diverging the moisture from the surface film having excellent moisture permeability and moisture releasing properties, it is possible to provide a shoe with less stuffy feet. As described above, the present invention brings about an even greater effect by appropriately selecting the materials constituting the present invention according to the intended use.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples. In the examples, “parts” and “%” are based on weight, and the characteristic measured values are obtained by the following methods.

(B) Moisture permeability According to the method of JIS L1099 A-1 method, the moisture permeability (g / m ²
day).

(B) Moisture absorption Moisture absorption (g / m ² ) when left for 1 hour in an atmosphere at a temperature of 23 ° C and a relative humidity of 30%, and then left for 30 minutes in an atmosphere of a temperature of 23 ° C and a relative humidity of 80%. Expressed by

(C) Humidity release The amount of water released (g / m ² ) when left for 1 hour in an atmosphere at a temperature of 23 ° C and a relative humidity of 80%, and then left for 30 minutes in an atmosphere at a temperature of 23 ° C and a relative humidity of 30%. Expressed by

(D) Bending resistance In accordance with the method of JIS K6545 method, it is represented by 1 to 5 grade.

Example 1 (Preparation of Synthetic Leather Base-1) A non-woven fabric made of polyester fiber having a weight of 280 g / m ² and a thickness of 1.0 mm was impregnated with a 13% polyester-polyurethane-dimethylformamide solution. The surface was coated with an 18% polyester-polyurethane-dimethylformamide solution at a basis weight of 600 g / m ² , and then immersion-coagulated, washed with water and dried to prepare a synthetic leather base.

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

Crisbon NY320 100 parts (Dainippon Ink and Chemicals Co., Ltd.) Howlack A1003 White 80 parts (Dainippon Ink and Chemicals Co., Ltd.) Howlack A1008 Mat 30 parts (Dainippon Ink and Chemicals Ltd.) Isopropyl alcohol 50 Part Methyl ethyl ketone 40 parts N, N-dimethylformamide 10 parts (Preparation of paint-2) Polyamino acid urethane (use of non-yellowing type urethane:
In 100 parts of N, N-dimethylformamide solution (solid content 10%) of LUCKSKIN-UA-3295A (polyamino acid segment 35%, manufactured by Seiko Chemical Co., Ltd.), synthetic polyamino acid particles (manufactured by Ajinomoto Co .; PA-1000; poly-γ-methyl-L-glutamate; average particle size: 10 μm) was added, mixed and dispersed to prepare a stable dispersion. Among them, a matting agent (manufactured by Dainippon Ink and Chemicals, Incorporated; Howlack B135)
6) 15 parts were added and uniformly mixed to obtain a dispersion liquid paint.

(Coating on Synthetic Leather Surface) Paint-1 on the surface of the synthetic leather base-1 created earlier.
Was applied and dried three times with a gravure coater (using a 110 mesh roll), and then patterned with a heated embossing roll. Then, the paint-2 was applied with a gravure coater (using a 110 mesh roll). Drying was repeated three times to obtain a synthetic leather having a white surface. When the surface of the obtained synthetic leather touches the skin, it does not feel cold, it feels warm, and even sweaty skin has no sticky feeling and has excellent tactile sensation, for volleyball, handball It was excellent. In addition, the moisture permeability was larger than that of conventional synthetic leather, and was excellent as an upper material for sports shoes. Table 1 shows the obtained characteristic values.

Example 2 (Preparation of Paint-3) Paint-3 was prepared with the following composition.

LUCKSKIN-UA3295A 100 parts (manufactured by Seiko Kasei Co., Ltd.) (18%) Ajicoat PA-1000 10 parts (manufactured by Ajinomoto Co .; average particle size 7 μm) Dairac SL-3440 Red 5 parts (Dainippon Ink & Chemicals, Inc.) )) N, N-dimethylformamide 40 parts Methyl ethyl ketone 40 parts (Coating on the surface of synthetic leather) Paint-3 was prepared in Example 1 for synthetic leather base-1.
Gravure coating machine (110 mesh rolls)
Then, coating and drying were repeated three times, and then patterned with a heated embossing roll to obtain a synthetic leather having a red coating film on the surface. The surface of the resulting synthetic leather, when touching the skin, does not feel cold, feels warm, and has excellent feeling without sweatiness even on sweaty skin, basketball, rugby It was excellent for balls. Table 1 shows the obtained characteristic values.

Example-3 (Preparation and application of paint-4) Polyamino acid urethane (use of non-yellowing type urethane:
Mitsubishi Chemical Corporation PAU-300: Polyamino acid segment 3
5%) N, N-dimethylformamide solution (solid content 15%)
100 parts of synthetic polyamino acid particles (Ajinomoto Co., Inc.)
(Agikoto PA-1000; poly-γ-methyl-L-glutamate; average particle size 7 μm) was added and mixed and dispersed to prepare a stable dispersion. Among them, black pigment (manufactured by Dainippon Ink and Chemicals, Inc .; DIRAC SL-343) as a colorant
0) 8 parts, and black dye (Kayaset BLACK, Nippon Kayaku Co., Ltd.)
-KR) was added and mixed uniformly to obtain a black paint. This black paint was applied on a patterned release paper so as to have a basis weight of 70 g / m ² and dried, and then an adhesive was applied so as to have a basis weight of 50 g / m ² and was prepared in Example 1. The surface of the synthetic leather base-1 thus obtained was stuck and sufficiently adhered. The surface of the synthetic leather separated from the release paper, when touching the skin, does not feel cold, feels warm, has excellent tackiness even with sweaty skin, and has excellent tactile sensation, tennis It was suitable for racket grip materials and glove flats. Table 1 shows the obtained characteristic values.

Example 4 (Synthesis create leather base -2) Weight 280 g / m ^2, the nonwoven fabric made of polyester fibers having a thickness of 1,0Mm, mixed polymers of polycarbonate-based polyurethane and a polyamino acid urethane (mixing ratio 60:40) N, N-dimethylformamide solution (concentration: 10%) in synthetic polyamino acid particles (manufactured by Ajinomoto Co., Inc .; Adiquat PA-1000; poly-γ)
-Methyl-L-glutamate; 5 parts of an average particle diameter of 7 μm) was added to a surface of an impregnated base material impregnated with a stable dispersion liquid mixed and dispersed, and a mixed polymer of a polycarbonate-based polyurethane and a polyamino acid urethane (mixing ratio: 60) : 40) in an N, N-dimethylformamide solution (concentration: 18%) in a synthetic polyamino acid particle (manufactured by Ajinomoto Co .; Adiquat PA-1000; poly-γ).
-Methyl-L-glutamate; 5 parts of average particle size) was added, mixed and dispersed, coated with a stable dispersion at a basis weight of 600 g / m ² , water-immersed and coagulated, washed with water and dried to prepare a synthetic leather base. did.

(Coating on Synthetic Leather Surface) The coating material-1 prepared in Example-1 was repeatedly coated and dried three times on the surface of the synthetic leather base-2 with a gravure coating machine (using a 110 mesh roll), and then After patterning with a heated embossing roll, paint-2 was applied to a gravure coater (11
Coating and drying were repeated three times, and then patterned with a heated embossing roll.
Was applied and dried three times with a gravure coater (using a 110 mesh roll) to obtain a synthetic leather having a white surface. The surface of the obtained synthetic leather was excellent in surface feel as in Example 1, but the moisture permeability, moisture absorption, and moisture release became more distinctive, and as an upper material for sports shoes, It was excellent with no stuffiness when worn. Table 1 shows the obtained characteristic values.

Using examples -5 (synthetic leather create a base -3) weight 280 g / m ^2, consisting of polyester fibers and rayon fibers having a thickness of 1.0 mm (mixing ratio 30:70) nonwoven, synthesis of Example -4 leather Synthetic leather base-3 was prepared in the same manner using the same synthetic resin as the base.

(Coating on Synthetic Leather Surface) The coating-drying machine (using a 110-mesh roll) was used to repeatedly apply and dry the coating material-3 prepared in Example-2 on the surface of the synthetic leather base-3 three times, and further heated. It was patterned with an embossing roll to obtain a synthetic leather having a red coating film on the surface. The surface of the obtained synthetic leather is excellent in surface texture as in Example-2, but has further characteristics of moisture permeability, moisture absorption, and moisture release, and is optimal for shoes and upper materials. Met. The obtained characteristic value is
It is shown in the table.

Example-6 Paint prepared in Example-3 on the surface of nylon taffeta
4 was applied to a basis weight of 70 g / m ² and dried. The obtained product had high moisture permeability, good touch, and was optimal for sports clothing. Table 1 shows the obtained characteristic values.

Comparative Example 1 (Preparation of Paint-5) Paint-5 was prepared with the following composition.

Haurak A3454 (20%) 100% (Dainippon Ink & Chemicals, Inc.) Ajicoat PA-1000 10 parts (Ajinomoto Co., Ltd .; average particle diameter 7 μm) Haurak A1008 Mat 30 parts (Dainippon Ink & Chemicals, Inc.) )) Isopropyl alcohol 50 parts Methyl ethyl ketone 50 parts (Coating on synthetic leather surface) Paint-1 is applied to the surface of the artificial leather base-1 prepared in Example-1 using a gravure roll (110 mesh).
After the drying was repeated three times, a pattern was formed with a heated embossing roll, and a paint-5 was coated on the surface with a gravure roll (11).
Coating and drying were repeated three times with a 0 mesh) to obtain a synthetic leather having a white surface. The resulting synthetic leather had an unsatisfactory moisture permeability, and when subjected to a bending test, powder likely to be synthetic polyamino acid particles Ajiko PA-1000 fell off. Table 1 shows the obtained characteristic values.

Comparative Example-2 (Preparation of Paint-6) Paint-6 was prepared with the following composition.

LUCKSKIN-UA3295A 100 parts (manufactured by Seiko Chemical Co., Ltd.) (18%) Haurak B1356 Mat 20 parts (manufactured by Dainippon Ink and Chemicals, Inc.) N, N-dimethylformamide 40 parts Methyl ethyl ketone 40 parts (to the surface of synthetic leather) Coating) Coating-1 is applied to the surface of the artificial leather base-1 created in Example-1 with a gravure roll (110 mesh).
After the drying was repeated three times, a pattern was formed with a heated embossing roll, and a coating material 6 was further coated with a gravure roll (11
Coating and drying were repeated three times with a 0 mesh) to obtain a synthetic leather having a white surface. The resulting synthetic leather had an unsatisfactory moisture permeability, and had a slightly sticky surface feel. Table 1 shows the obtained characteristic values.

Comparative Example-3 (Preparation of Paint-7) Paint-7 was prepared with the following composition.

Haurac A3454 (20%) 100 parts (Dainippon Ink and Chemicals, Inc.) Haurac A1008 Mat 30 parts (Dainippon Ink and Chemicals, Inc.) Isopropyl alcohol 50 parts Methyl ethyl ketone 50 parts (Coating on the surface of synthetic leather) Paint-1 is applied to the surface of the synthetic leather base-1 prepared in Example-1 with a gravure roll (110 mesh).
After the drying was repeated three times, a pattern was formed with a heated embossing roll, and a paint-7 was coated on the surface with a gravure roll (11).
Coating and drying were repeated three times with a 0 mesh) to obtain a synthetic leather having a white surface. The resulting synthetic leather has an unsatisfactory moisture permeability, and the surface feel is a sticky feeling peculiar to polyurethane of conventional synthetic leather, especially when touching with sweaty skin. Came out. Table 1 shows the obtained characteristic values.

Claims (5)

(57) [Claims] 1. A high-permeability coating comprising a synthetic leather substrate composed of a fibrous material and a synthetic resin, on the surface of which is formed a film mainly composed of a polyamino acid urethane resin in which synthetic polyamino acid particles are dispersed in the synthetic resin. Wet synthetic leather. 2. The method of claim 1, wherein the polyamino acid urethane resin is poly-γ-polyurethane.
The synthetic leather according to claim 1, which is a polyamino acid segment containing methyl-L-glutamate as a main component, and has a content of 3% to 85% by weight based on the weight of the polyamino acid urethane resin. 3. The synthetic leather according to claim 1, wherein the synthetic polyamino acid particles are poly-γ-methyl-L-glutamate. 4. The synthetic leather according to any one of (1) to (3), wherein the synthetic resin constituting the synthetic leather substrate is a synthetic resin mainly composed of a polyamino acid urethane resin. 5. The synthetic leather constituting the synthetic leather substrate is obtained by dispersing synthetic polyamino acid particles in a synthetic resin mainly comprising a polyamino acid urethane resin.
The synthetic leather according to any one of (4).