JP2955204B2 - Leather-like sheet and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a shoe upper material, a shoe sole insole material,
The present invention relates to a leather-like sheet excellent in breathability and moisture permeability which is suitably used as a material of clothing and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Hitherto, as a material for shoe upper materials, shoe insole materials, clothing and the like, a leather-like sheet material simulating natural leather, that is, a wet porous layer of polyurethane resin on a fiber base material, a dry porous material, After forming a dry layer or a dry foam layer, a surface layer corresponding to the silver surface of natural leather is laminated, sprayed,
A leather-like sheet formed by a gravure method or the like is often used.

[0003]

However, the above-mentioned leather-like sheet material is inferior in air permeability and moisture permeability due to its production method and structure. Therefore, when such a leather-like sheet-like material is used as a shoe upper material, a shoe sole insole material, or the like, there has been a problem that the foot gets stuffy when worn. The present invention has been made in order to solve the above-mentioned drawbacks, and provides a leather-like sheet having not only an appearance and a feeling very similar to natural leather but also breathability and moisture permeability. The purpose is to do so.

[0004]

The leather-like sheet of the present invention made to solve the above-mentioned problem is a leather-like sheet having a fiber base, a polyurethane resin layer, and a surface finishing layer. Wherein the polyurethane resin layer is a polyurethane resin layer obtained by impregnating and / or applying a polyurethane resin solution containing a fine polyethylene powder having an average particle size of 5 to 50 μm on a fiber base material and wet-solidifying. It is assumed that.

Further, a method for producing a leather-like sheet according to the present invention, which has been made to solve the above-mentioned problems, is characterized in that a fiber base material is impregnated with a polyurethane resin solution containing fine polyethylene powder having an average particle size of 5 to 50 μm. And / or a step of coating, dipping the fiber base material impregnated and / or coated with the polyurethane resin solution in a non-solvent, wet-coagulating the polyurethane resin, removing the solvent, washing with water, and then drying it to form fine pores on the surface. A step of forming a polyurethane resin porous layer having the following, and a step of surface finishing.

[0006] Examples of the fiber base material used in the present invention include a knitted fabric, a woven fabric, and an entangled nonwoven fabric made of fibers having a single yarn fineness of 2 denier or less. The entangled nonwoven fabric is a nonwoven fabric entangled by a needle punch or a high-speed fluid flow, and is provided with an elastic polymer such as a polyurethane resin or a synthetic rubber as required. When a knitted fabric or a woven fabric is used as the fiber base material, it is preferable that at least the surface to be impregnated and / or coated with the polyurethane resin solution is raised or raised. Furthermore, the weight of the fiber base material is not particularly limited, and is appropriately selected depending on the use of the leather-like sheet. For example, when used as a material for shoes, a fiber base material of about 200 to 400 g / m ² is used.

The fibers constituting the fiber base material include, for example, synthetic fibers such as polyester, polyamide, polyacrylonitrile, polyolefin and polyvinyl alcohol;
Natural fibers such as cotton and hemp, and regenerated fibers such as rayon, swoof, and acetate alone or blended fibers thereof, or modified into ultrafine fibers by dissolving and removing at least one component or splitting bicomponent fibers. Multicomponent fibers and the like can be used.

In order to improve the texture of the obtained leather-like sheet, the above-mentioned fiber base material is coated with polyvinyl alcohol, silicone, or a mixture thereof before the application and / or impregnation of a polyurethane resin solution. May be fixed. At this time, the attached amount of polyvinyl alcohol or the like is about 1 to 15% by weight based on the fiber base material. Further, the fiber base material may be subjected to surface smoothing for the purpose of improving the surface smoothness of the obtained sheet.

The polyurethane resin used in the present invention comprises:
A polyol having an average molecular weight of 500 to 3000, for example, one or more polyol components selected from polyester-based polyols, polyether-based polyols, polyester-ether-based polyols, polycaprolactone-based polyols, polymethylvalerolactone-based polyols, and polycarbonate-based polyols; One or more isocyanate components selected from aliphatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, aliphatic diisocyanates having a cyclic group, and the like; and low molecular compounds having at least two active hydrogen atoms, for example, aliphatic diols, alicyclics Diol, aliphatic diamine, alicyclic diamine, hydrazine derivative and the like, and obtained by reacting with one or more chain extenders. In addition, these polyurethane resins, for example, amino acids, silicone,
It may be a modified polyurethane resin obtained by reacting with fluorine or the like. The composition of the polyurethane resin can be appropriately selected depending on the intended use and purpose of the leather-like sheet.

The polyurethane resin preferably has a 100% modulus of 10 to 120 kg / cm ² .
When the 100% modulus is too small, the mechanical strength of the obtained leather-like sheet decreases, while when the 100% modulus is too large, the texture of the obtained leather-like sheet becomes hard.

The polyurethane resin is added with various additives, if necessary, such as a coagulation regulator (surfactant), a coloring agent, a filler, an antioxidant, and a water / oil repellent. It is dissolved in a solvent such as dimethylacetamide, N-methylpyrrolidone, dimethylsulfoxide, etc., to obtain a polyurethane resin solution having an appropriate concentration. Of the above solvents, dimethylformamide is particularly preferred.

[0012] In the leather-like sheet of the present invention, polyethylene fine powder is added to the polyurethane resin solution in order to impart air permeability and moisture permeability. After the polyurethane resin solution containing the polyethylene fine powder is applied and / or impregnated, the polyurethane resin is wet-coagulated so that the polyethylene fine powder is desorbed and pores of an appropriate size are formed on the surface of the polyurethane resin layer. Are formed with pores having a diameter of about 5 to 100 μm, and the leather-like sheet is provided with air permeability and moisture permeability.

In the leather-like sheet of the present invention, the average particle size is 5 to 5.
Low-density polyethylene fine particles having a thickness of 50 μm, preferably 10 to 30 μm and insoluble in the solvent for the polyurethane resin described above are used. The use of polyethylene fine powder having an average particle size of less than 5 μm has a problem that the particles of the polyethylene fine powder are agglomerated and a problem that the polyethylene fine powder is hard to be detached and the air permeability and the moisture permeability are not sufficiently provided. If a polyethylene fine powder having a particle size of more than 30 μm is used, there is a problem that pores formed on the surface of the polyurethane resin layer become too large and water resistance deteriorates.

The amount of the polyethylene fine powder to be added is about 1 to 40 parts by weight based on 100 parts by weight of the polyurethane resin. If the added amount of the polyethylene fine powder is too small, there is a problem that air permeability and moisture permeability are not sufficiently provided.On the contrary, if the added amount of the polyethylene fine powder is too large, the mechanical strength of the polyurethane resin layer deteriorates, There is a problem that the texture of the obtained leather-like sheet becomes hard.

The surface finishing layer formed on the surface of the polyurethane resin layer is formed of a polyurethane resin solution containing a coloring agent and various additives by a gravure roll coater or the like, a polyamide resin solution, an acrylic resin solution, or the like, similarly to a conventional leather-like sheet. It is formed by means such as applying a surface treatment agent such as a system resin solution, a polyamino acid resin solution, or a mixed solution thereof. Needless to say, as the solvent used for the surface treatment agent used at this time, a solvent that does not block the pores formed on the surface by dissolving the polyurethane resin layer is used.

The leather-like sheet of the present invention can be subjected to secondary processing such as embossing or kneading with a stamping roll or the like, if necessary, similarly to a conventional leather-like sheet.

Next, a method for producing the leather-like sheet of the present invention will be described.

First, if necessary, raising or raising hair,
A polyurethane resin solution to which the above-mentioned fine polyethylene powder is added is applied and / or impregnated on a fiber base material fixed with polyvinyl alcohol or the like or surface smoothed. Means for applying and / or impregnating the polyurethane resin solution include, for example, dipping and application using a knife coater or the like, similarly to the conventional one.

Next, the fiber base material coated and / or impregnated with the polyurethane resin solution is immersed in a non-solvent such as water or an aqueous solution of a solvent used in the polyurethane resin solution, preferably a 0 to 20% aqueous solution of dimethylformamide. After coagulating and desolvating the polyurethane resin, washing with water and drying are performed.
At this time, the solidification temperature of the polyurethane resin is 15 to 40.
It is preferable that the temperature be appropriately selected in the range of ° C. By this step, the polyethylene fine powder added to the polyurethane resin solution is detached, and appropriate pores are formed on the surface of the polyurethane resin layer.

Further, a polyurethane resin solution containing a coloring agent and various additives, a polyamide resin solution, an acrylic resin solution, a polyamino acid resin, and the like, are coated on the polyurethane resin layer by a conventional gravure roll coater or the like. A surface treatment agent such as a solution or a mixed solution of these resins is applied and subjected to surface finishing to obtain a leather-like sheet. In addition, similarly to the conventional leather-like sheet, the obtained leather-like sheet is subjected to embossing with an embossing roll or the like to impart unevenness to the surface of the leather-like sheet,
It is also possible to perform secondary processing such as performing kneading.

[0021]

The leather-like sheet according to the present invention comprises a polyurethane resin forming a polyurethane resin layer, a fine powder of polyethylene having a specific particle diameter insoluble in a solvent of the polyurethane resin solution, and wet coagulation of the polyurethane resin solution. Since the polyurethane resin layer is formed in this manner, appropriate pores are formed on the surface of the polyurethane resin layer, and the polyurethane resin layer has air permeability and moisture permeability.

[0022]

The present invention will be described in more detail with reference to specific examples below, but the present invention is not limited to the following examples.

[Example 1] Nylon / polyester (5
0/50), a fiber web of a splittable fiber having a single fiber fineness of 0.2 denier after division and a fiber length of 30 to 40 mm is needle-punched, and then entangled by high-speed fluid flow processing. Non-woven fabric (weight 200 g / m ² , apparent density 0.22 g / cm ³ ) was added to silicone (Geranex S
H: 2 parts by weight, manufactured by Matsumoto Yushi Co., Ltd., 2 parts by weight of polyvinyl alcohol (GOSELUL GL-05: manufactured by Nippon Gosei)
Immerse in a processing solution consisting of 96 parts by weight of water, and reduce the drawing rate by 120%.
And dried at 100 to 130 ° C. for 7 minutes with a hot air circulating dryer, followed by pressure bonding with a roll heated to 180 ° C. for 2 minutes to perform surface smoothing to obtain a fiber base material. .

The obtained fiber base material was impregnated with a polyurethane resin solution having the composition shown in Table 1 by the DIP-NIP method (basis weight 550 g / m ² ), and then the polyurethane resin solution shown in Table 2 was added. Using a knife coater, the mixture was uniformly applied (basis weight: 700 g / m ² ).

[0025]

[Table 1] Polyester polyurethane resin ^{* 1} 100 parts by weight Polyethylene fine powder ^{* 2} 10 parts by weight Anionic surfactant 0.5 parts by weight Nonionic surfactant 0.5 parts by weight Silicone foam stabilizer 0.5 parts by weight Part Colorant 10 parts by weight Dimethylformamide (solvent) 125 parts by weight * 1 Crisbon 8006HV: manufactured by Dainippon Ink and Chemicals, Inc. (100% modulus 35 kg / cm ² , solid content 30%) * 2 FLOWSEN UF1.5: Sumitomo Seika Made by the company (Average particle size 10-20 μm)

[0026]

[Table 2] Polyester polyurethane resin ^{* 1} 100 parts by weight Polyethylene fine powder ^{* 2} 10 parts by weight Anionic surfactant 1 part by weight Nonionic surfactant 1 part by weight Silicone foam stabilizer 0.5 part by weight Colorant 10 Parts by weight dimethylformamide (solvent) 58 parts by weight

Next, the fiber base material coated with and impregnated with a polyurethane resin is immersed in a 12% aqueous solution of dimethylformamide (solution temperature: 25 ° C.) to coagulate the polyurethane resin, and then the mixture is heated in hot water at 60 ° C. After removing the solvent and washing with water for one minute, the polyethylene fine powder contained in the polyurethane resin solution was removed, and dried with a hot air circulating drier at 100 to 130 ° C. for 10 minutes to form a polyurethane resin layer. 5 to 20 μm on the surface of the obtained polyurethane resin layer
Many pores having a diameter were formed.

Further, a polyurethane resin surface treating agent to which a coloring agent has been added is applied four times with a gravure roll of 80 mesh onto the polyurethane resin layer, and then heated and pressed with an embossing roll having a squeezing pattern on the surface. Embossing was performed to obtain a leather-like sheet. The obtained leather-like sheet material had a sense of unity, had a moderate waist and a soft texture, and was excellent in breathability, moisture permeability and water resistance. Further, the obtained leather-like sheet was tested for air permeability, moisture permeability and water resistance by the following methods. Table 7 shows the results.

[Test Method] (1) Air permeability According to the method specified in "JIS P 8117", the air permeability was measured per hour using a Gurley densometer (l / cm ² · hr). ). (2) Moisture Permeability The moisture permeability (g / m ² · 24 hr) was measured according to the method of condition B defined in “JIS Z 0208”. (3) Water resistance The water resistance water column (mmH ₂ O) was measured according to the method A defined in “JIS L 1092”.

Example 2 Nylon / Polyester (5
0/50), a fiber web of split type fibers having a denier of 1.0 denier and a fiber length of 30 to 40 mm after splitting is needle-punched, and then entangled by high-speed fluid flow processing. Non-woven fabric (weight 250 g / m ² , apparent density 0.25 g / cm ³ ) was added to silicone (Geranex S
H: 2 parts by weight, manufactured by Matsumoto Yushi Co., Ltd., 2 parts by weight of polyvinyl alcohol (GOSELUL GL-05: manufactured by Nippon Gosei)
Immerse in a processing solution consisting of 96 parts by weight of water, and reduce the drawing rate by 120%.
And dried at 100-130 ° C. for 10 minutes with a hot-air circulation dryer, and then rolled at 180 ° C. with a roll 2
The surface was smoothed by pressing under pressure for a minute to obtain a fiber base material.

The obtained fiber base material was impregnated with a polyurethane resin solution having the composition shown in Table 3 by the DIP-NIP method (basis weight 750 g / m ² ). Using a knife coater, the mixture was uniformly applied (basis weight: 800 g / m ² ).

[0032]

[Table 3] Polyester polyurethane resin ^{* 3} 100 parts by weight Polyethylene fine powder ^{* 4} 5 parts by weight Fluorine-containing urethane resin 1 part by weight Anionic surfactant 0.5 parts by weight Nonionic surfactant 0.5 parts by weight Silicone type Foam stabilizer 0.5 parts by weight Coloring agent 10 parts by weight Dimethylformamide (solvent) 125 parts by weight * 3 Resamine CU4310: manufactured by Dainichi Seika Co., Ltd. (100% modulus 40 kg / cm ² , solid content 26%) * 4 FLOWSEN UF- 20: manufactured by Sumitomo Seika (average particle size: 20 to 30 μm)

[0033]

[Table 4] Polyester polyurethane resin ^{* 3} 100 parts by weight Polyethylene fine powder ^{* 4} 5 parts by weight Fluorine-containing urethane resin 1 part by weight Anionic surfactant 0.5 parts by weight Nonionic surfactant 2 parts by weight Silicone foam 1 part by weight Colorant 10 parts by weight 52% by weight of dimethylformamide (solvent)

Next, the fiber substrate coated with and impregnated with a polyurethane resin is immersed in a 12% aqueous solution of dimethylformamide (solution temperature: 25 ° C.) to coagulate the polyurethane resin, and then the mixture is heated in hot water at 60 ° C. After removing the solvent and washing with water for one minute, the polyethylene fine powder contained in the polyurethane resin solution was removed, and dried with a hot air circulating drier at 100 to 130 ° C. for 10 minutes to form a polyurethane resin layer. 5 to 30 μm on the surface of the obtained polyurethane resin layer
Many pores having a diameter were formed.

Further, a polyurethane resin surface treatment agent to which a coloring agent is added is applied four times with a gravure roll of 80 mesh on the polyurethane resin layer, and then heated and pressed with an embossing roll having a pore pattern on the surface. Embossing was performed and further rubbing was performed to obtain a leather-like sheet. The obtained leather-like sheet material had a sense of unity, had a moderate waist and a soft texture, and was excellent in breathability, moisture permeability and water resistance. Further, the air permeability, moisture permeability, and water resistance of the obtained leather-like sheet were measured in Example 1.
The test was performed in the same manner as described above. Table 7 shows the results.

[Example 3] Polyester fiber (1.2 denier) and rayon fiber (1 denier) were blended (weight ratio 65/35), woven into a twill weave, and silicone (Geranex SH: Matsumoto) 2 parts by weight
It is immersed in a treatment liquid consisting of 2 parts by weight of polyvinyl alcohol (Gosellur GL-05: manufactured by Nippon Gosei Co., Ltd.) and 96 parts by weight of water, squeezed at a squeezing rate of 100%, and heated to 100 to 130 ° C. with a hot air circulation dryer. After drying for 7 minutes with a roll heated to 180 ° C., pressure bonding was performed for 2 minutes to perform surface smoothing processing to obtain a fiber base material.

The obtained fiber base material was impregnated (with a basis weight of 500 g / m ² ) with a polyurethane resin solution having the composition shown in Table 5 by the DIP-NIP method. Using a knife coater, the mixture was uniformly applied (basis weight: 800 g / m ² ).

[0038]

[Table 5] Polyester / ether-based polyurethane resin ^{* 5} 100 parts by weight Polyethylene fine powder ^{* 6} 3 parts by weight Anionic surfactant 1 part by weight Nonionic surfactant 1 part by weight Silicone foam stabilizer 0.5 part by weight Coloring Agent 10 parts by weight Dimethylformamide (solvent) 130 parts by weight * 5 Crisbon MP-145: manufactured by Dainippon Ink and Chemicals, Inc. (100% modulus 40 kg / cm ² , solid content 30%) * 6 Flowbeads CL-2080: Sumitomo Chemical Made by the company (average particle size 10μm)

[0039]

[Table 6] Polyester / ether-based polyurethane resin ^{* 5} 100 parts by weight Polyethylene fine powder ^{* 6} 3 parts by weight Anionic surfactant 1 part by weight Nonionic surfactant 2 parts by weight Silicone foam stabilizer 1 part by weight Colorant 10 Parts by weight dimethylformamide (solvent) 60 parts by weight

Next, the fiber substrate coated with and impregnated with a polyurethane resin is immersed in a 15% aqueous solution of dimethylformamide (solution temperature: 25 ° C.) to coagulate the polyurethane resin, and then the mixture is heated to 60 ° C. in warm water. After removing the solvent and washing with water for one minute, the polyethylene fine powder contained in the polyurethane resin solution was removed, and dried with a hot air circulating drier at 100 to 130 ° C. for 10 minutes to form a polyurethane resin layer. 5 to 10 μm on the surface of the obtained polyurethane resin layer
Many pores having a diameter were formed.

Further, a polyurethane resin surface treatment agent to which a coloring agent was added was applied four times with a 100 mesh gravure roll on the polyurethane resin layer, and then heated and pressed with a embossing roll having a squeezing pattern on the surface. The leather-like sheet was obtained by embossing. The obtained leather-like sheet material had a sense of unity, had a moderate waist and a soft texture, and was excellent in breathability, moisture permeability and water resistance. Further, the obtained leather-like sheet was tested for air permeability, moisture permeability, and water resistance in the same manner as in Example 1. Table 7 shows the results.

Comparative Example 1 A leather-like sheet was obtained in the same manner as in Example 1 except that the polyethylene fine powder was not added to the polyurethane resin solutions shown in Tables 1 and 2. The obtained leather-like sheet material had a sense of unity, had a moderate waist and a soft texture, but was inferior in air permeability and moisture permeability. Further, the obtained leather-like sheet was tested for air permeability, moisture permeability, and water resistance in the same manner as in Example 1. Table 7 shows the results.

Comparative Example 2 A leather-like sheet was produced in the same manner as in Example 1 except that the amount of the polyethylene fine powder added to the polyurethane resin solutions shown in Tables 1 and 2 was changed to 0.5 part by weight. I got The obtained leather-like sheet material is
It had a sense of unity and had a moderate waist and soft texture, but was inferior in breathability and moisture permeability. Further, the obtained leather-like sheet was tested for air permeability, moisture permeability, and water resistance in the same manner as in Example 1. Table 7 shows the results
Shown in

Comparative Example 3 A leather-like sheet was prepared in the same manner as in Example 1 except that the polyethylene fine powder added to the polyurethane resin solutions shown in Tables 1 and 2 was changed to a powder having an average particle diameter of 180 μm. Obtained. The obtained leather-like sheet-like material had a sense of unity, had a moderate waist and a soft texture, and had excellent breathability and moisture permeability,
It was poor in water resistance. Further, the obtained leather-like sheet was tested for air permeability, moisture permeability, and water resistance in the same manner as in Example 1. Table 7 shows the results.

[0045]

[Table 7]

[0046]

As described in detail above, the leather-like sheet of the present invention and the leather-like sheet obtained by the method for producing the leather-like sheet of the present invention have excellent air permeability and moisture permeability. , And is also excellent in water resistance, in which the occurrence of stuffiness is a problem, for example, shoe upper materials, shoe sole insole materials,
It is suitably used as a material for clothing and the like.

Claims (2)

(57) [Claims] 1. A leather-like sheet having a fiber substrate, a polyurethane resin layer and a surface finishing layer, wherein the polyurethane resin layer has an average particle size of 5 to 50 μm on the fiber substrate.
A leather-like sheet which is a polyurethane resin layer obtained by impregnating and / or applying a polyurethane resin solution containing polyethylene fine powder of the above and wet-solidifying. 2. A step of impregnating and / or applying a polyurethane resin solution containing a fine polyethylene powder having an average particle diameter of 5 to 50 μm to the fiber base material, and applying a non-solvent to the fiber base material impregnated and / or coated with the polyurethane resin solution. A process of immersing the polyurethane resin in a wet state to wet-solidify the polyurethane resin, removing the solvent, washing with water, and then drying to form a polyurethane resin porous layer having fine pores on its surface. A method for producing a sheet-like material.