JPH0841786A - Silvered-type synthetic leather substitute and its production - Google Patents

Abstract

PURPOSE:To produce a new silvered-type synthetic leather substitute free from stuffy feeling, resistant to staining when used as shoes, clothes, etc., and having smooth and elegant appearance and abrasion resistance at the same time. CONSTITUTION:This silvered-type synthetic leather substitute is obtained by forming a polyurethane layer (b) having communicating pores and a thickness of 50-300mum, on one side of a base material (a) consisting of fibrous material or a fibrous material and a polymer elastic material, and further forming a finishing polyurethane coating (c) thereon. In the obtained silvered-type synthetic leather substitute, open holes of 0.5-35mum in diameter are distributed on the surface in a density of >=200 per 1cm<2> and their inner walls are covered with the finishing polyurethane coating (c). The open holes are formed in such a manner as to reach to the communicating pores of the polyurethane layer (c). The silvered-type synthetic leather substitute has an air permeability of >=0.5liter/cm<2>.hr and a moisture permeability of >=6mg/cm<2>.hr. The method for producing the silvered-type synthetic leather substitute is also provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a silver-toned artificial material having functionality such as breathability and moisture permeability, and improved surface smoothness, antifouling property, abrasion resistance, etc. The present invention relates to leather and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, artificial leather composed of fibrous material and polymer elastic body has been widely used as a substitute for leather for shoe upper materials, shoe accessory materials, clothing materials, etc. Has become an indispensable material. These artificial leathers are roughly classified into suede type, nubuck type, and silvered type according to their surface morphology. Among them, the suede type and nubuck type have high breathability and moisture permeability, but the silver type has a non-porous surface synthetic resin, so its breathability and moisture permeability are high. The current situation is that is not satisfied. In particular, when it is used for shoe upper materials and clothing, the "feeling of stuffiness" at the time of wearing is great, and improvement from the market is desired.

In order to solve these problems, an attempt is made to reduce the "stuffy feeling" during wearing by mechanically making holes with a needle to give breathability to the surface of the artificial leather of the type with silver. However, in this case, the diameter of the needle hole is too large, so that dirt may get into the hole when worn, causing a defect in appearance, or even if the hole is open, sufficient transparency is obtained. The humidity is not obtained and the objective is not achieved.

There is also proposed a method in which a finish polyurethane film is formed on the surface where fibrous material and polymer elastic material are mixed, and the property of the discontinuous film is utilized. Since it is too large, it causes dirt, and the fiber skin cannot be concealed and a smooth, elegant appearance cannot be obtained.
Alternatively, the porous polyurethane layer is not provided, so that there are drawbacks such as poor abrasion resistance, and therefore it is not satisfied.

Further, Japanese Patent Laid-Open No. 59-116479 proposes a method of forming pores by forming a silver surface on the surface of fibers or a mixture of fibers and a high molecular weight polymer. However, in this method, since the silver surface layer is directly formed on the fibrous material, the fiber skin is directly formed at the time of stretching, so that the fiber skin is likely to appear at the time of stretching, or the cushion is formed because there is no porous polyurethane layer. At present, they are not satisfactory for shoe applications because they have drawbacks such as poor performance and poor abrasion strength.

Further, Japanese Patent Laid-Open No. 3-79443 proposes a method for producing a synthetic leather having ventilation and moisture permeability by forming a finishing polyurethane coating as a porous coating from W / O emulsion. However, in this method, since the finish polyurethane coating on the outermost surface is porous, its mechanical strength is weaker than that of the non-porous polyurethane coating, and the abrasion resistance is defective. Further, it is a prerequisite that stable open pores are formed on the surface of the wet porous polyurethane layer, and this method cannot be said to be industrially completed. Furthermore, handling of W / O emulsions is subject to many restrictions in terms of pot life, spreadability, etc., and requires sophisticated technology, which has not been industrially implemented at this stage. In addition, polyurethane resin
When an attempt is made to form a porous film by the / O emulsion method, there is a large shrinkage during solvent evaporation and drying, and what is once formed as a porous film is enriched, and there are many restrictions on environmental conditions for controlling the porosity. In order to avoid such a restriction, JP-A-3-
As disclosed in Japanese Patent No. 90684, a method mainly composed of polyamino acid has been proposed, but it is economically disadvantageous because it is industrially manufactured but its price is high.

Further, Japanese Patent Laid-Open No. 3-140320 proposes a method of producing a breathable artificial leather by forming a polyamino acid urethane as a porous finish coating by using a phase separation coagulation nucleating agent in combination. . However, also in this method, since the finish polyurethane coating on the outermost surface is porous as described above, its mechanical strength is weaker than that of the non-porous polyurethane coating, and the abrasion resistance is defective, or There are many problems such as that open pores must be stably formed on the surface of the wet porous polyurethane layer.
Further, polyamino acid urethane is disadvantageous in that it is expensive and economical.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide shoes,
Providing a low-priced new artificial leather with a silver finish, which has a low damp feel when used or worn for clothing, is hard to stain, and has a smooth and elegant surface appearance and abrasion resistance. Especially.

[0009]

According to the present invention, a continuous porous polyurethane layer (b) having a thickness of 50 μm to 300 μm is provided on one surface of a substrate (a) made of a fiber or a fiber and a polymer elastic material. Is formed on the surface of the silver-finished artificial leather having a finished polyurethane coating (C) formed on the surface thereof with open pores having a diameter of 0.5 μm to 35 μm of 1 cm.
There above 200 per ^2, finishing polyurethane film (c) covers the pore walls of the open pores is formed so as to reach inside the communicating porous polyurethane layer (b), air permeability 0.5 l / cm ²・ Hr or higher, moisture permeability 6 mg /
It is an artificial leather with a silver tone that is at least cm ² · hr.

Further, according to the present invention, a continuous porous polyurethane layer (b) having a thickness of 50 μm to 300 μm is formed on one surface of a substrate (a) composed of a fibrous material or a fibrous material and a polymeric elastic body by a wet method. In the method for producing a silver-tone artificial leather by forming a finished polyurethane coating (C) on the surface of the continuous porous polyurethane layer (B),
A good solvent, a poor solvent, a mixed solvent of a good solvent and a poor solvent, or a mixed solvent of a good solvent and a non-solvent of polyurethane is applied with a gravure mesh roll, and the surface has a diameter of 5 μm.
It is possible to generate open pores of ˜40 μm, then form a finished polyurethane coating (c), and express the open pores of the communicating porous polyurethane layer (b) in the finished polyurethane coating (c) as open pores. A method for producing the above-mentioned silver-tone artificial leather, which is characterized.

The fibers constituting the silver-tone artificial leather of the present invention include woven fabrics, knitted fabrics, non-woven fabrics and the like made of conventionally known natural fibers, regenerated fibers and synthetic fibers. For the purpose of reducing the "stuffy feeling" during wearing of the present invention, a fiber material having a high hygroscopic property is desirable in the sense that the back surface side has a sweat absorbing property. Therefore, rayon fibers having high hygroscopicity are preferably used. However, in consideration of the physical strength of the sheet-like material, it is preferable to use the polyester fiber such as polyethylene terephthalate or the fiber having high physical strength such as polyamide fiber in combination.

The polymer elastic body of the present invention is a polymer elastic body used as a conventionally known leather substitute. For example, polyurethane, polyurea, polyurethane polyurea, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and the like, these are water-based emulsion,
Alternatively, after impregnating the fibrous material as a solvent solution, the fibrous material is coagulated to obtain a substrate (ii) composed of the fibrous material and the elastic polymer.

As the continuous porous polyurethane layer (b) formed on one surface of the substrate (a) composed of these fibers or the fibers and the polymer elastic material, all conventionally known polyurethanes can be applied. Those formed by a conventionally known molding method can be applied. For example, a solution of polyurethane in an organic solvent is coated on one surface of a substrate (a) composed of fibrous material or a fibrous material and a polymeric elastic material, and then is miscible with a non-solvent of polyurethane and an organic solvent in which polyurethane is dissolved. A method of causing coagulation in a coagulating bath, or a solution of polyurethane in an organic solvent, or a W / O type emulsion in which water is finely dispersed in a dispersion is made of a fiber or a fiber and a polymer elastic body. After coating on one side of the substrate (a), there is a method in which the organic solvent is selectively evaporated to solidify the polyurethane.

The continuous porous polyurethane layer of the present invention (b)
The thickness is 50 μm to 300 μm, preferably 100 to 200 μm in order to obtain wear resistance, surface smoothness, cushioning property and volume feeling. If the thickness is less than 50 μm, it is not preferable because a fibrous texture appears on the surface and it is difficult to obtain a smooth feeling on the surface. On the other hand, the thickness is 3
When it exceeds 00 μm, it is not preferable because it becomes a rubber-like artificial leather and productivity is reduced.

Since the purpose of the present invention is air permeability, the continuous porous polyurethane layer (b) must be continuous porous. That is, the communicating porous polyurethane layer (b) needs to have air permeability from the surface of the substrate (a) side composed of the fibrous material or the fibrous material and the polymer elastic body to the surface by the communicating hole. In any of the above-mentioned conventional methods, since the outermost surface of the porous polyurethane layer becomes dense, even if a small amount of air permeability is obtained, the open pores are dissolved by the solvent when forming the finished polyurethane film. It is either closed or hidden by the finishing polyurethane and loses breathability. There is also a method of increasing the diameter of the open pores on the surface by using a porosity adjusting agent (coagulation adjusting agent) together when molding the porous polyurethane, but in most cases, the same reason as above when forming the finished polyurethane film Breathability is lost. The present invention has been earnestly studied and completed a method for forming an open hole having an appropriate diameter in which air permeability is not lost when forming a finished polyurethane coating (C). The production method of the present invention will be described below.

In order to ensure that open pores appear on the surface of the porous polyurethane layer (b), a good solvent, a poor solvent, or a mixture of a good solvent and a poor solvent of polyurethane is mixed on the surface of the porous polyurethane layer (b). Either the solvent or a mixed solvent of a good solvent and a non-solvent is applied with a gravure mesh roll. Here, the good solvent of polyurethane means a good solvent capable of dissolving the polyurethane actually used,
For example, in the case of polyurethane synthesized from aromatic organic diisocyanate, polar solvents such as dimethylformamide, tetrahydrofuran and dioxane can be used.
Further, the poor solvent of polyurethane is a solvent that can swell but does not dissolve the polyurethane actually used, for example, ketones such as methyl ethyl ketone, alcohols such as isopropyl alcohol, and aromatic solvents such as toluene. Can be mentioned. Further, the non-solvent of polyurethane is one that does not dissolve or swell the polyurethane that is actually used, and is typically water.

By selecting these solvents, the solubility in the polyurethane actually used can be adjusted, and appropriate open pores can be developed. In this case, if a solvent having too high a solubility is used, the open pores will once appear, but due to the too strong a solubility, the open pores will be closed again in the process of evaporation and drying of the solvent. on the other hand,
On the contrary, if a solvent having too weak solubility is used, open pores do not appear.

A properly selected solvent is applied to the surface of the continuous porous polyurethane layer (b) with a gravure mesh roll. In this case, the size of the mesh of the gravure mesh roll greatly affects the size of the diameter of the open hole formed. That is, if a roll with a fine mesh is used, an open hole with a relatively small diameter is obtained, and if a roll with a coarse mesh is used, an open hole with a relatively large diameter is obtained. Further, the coating pressure also affects the size of the diameter of the open hole formed. That is, if the coating pressure is large,
The obtained open holes have a large diameter, and if the coating pressure is low, the obtained open holes have a small diameter. As mentioned above,
By selecting the appropriate solvent, selecting the gravure mesh roll, and optimizing the coating pressure, the communicating porous polyurethane layer (b)
5 μm to 40 μm, preferably 10 μm to 30 on the surface of
Develop an opening of μm.

After making open pores of 5 μm to 40 μm on the surface of the continuous porous polyurethane layer (b), a finish polyurethane coating (c) is formed on the surface. In the present invention, it goes without saying that the finish polyurethane coating (c) is formed on the surface of the continuous porous polyurethane layer (b).
Abrasion resistance and antifouling are obtained by coating the pore walls of the open pores formed on the surface of the communicating porous polyurethane layer (b) and also covering the inside of the communicating porous polyurethane layer (b). It is necessary from the viewpoint of sex. Such a finished polyurethane coating (c) can be formed by applying an organic solvent solution of polyurethane as a paint on the surface of the continuous porous polyurethane layer (b) having open pores. That is, when the coating material is applied to the surface of the communicating porous polyurethane layer (b) having the open pores, the paint flows into the open pores and the pore walls are also applied. In this case, the viscosity of the coating material also has an important influence on the coating amount on the pore wall and the coating depth on the communicating porous polyurethane layer (b), but it is the viscosity of a general gravure coating coating. A centipoise to 200 centipoise, preferably 100 centipoise to 140 centipoise is sufficient to achieve the structure of the present invention.

In this case, the type of organic solvent used in the coating material for forming the finished polyurethane coating (C) has a great influence on the diameter of the finally formed open pores. That is, if the solubility of the polyurethane forming the porous layer is large, the pore walls of the open pores previously formed on the surface of the communicating porous polyurethane layer (b) are dissolved to reduce the pore diameter. Is. The smaller the solubility, the more the diameter of the open pores expressed on the surface of the continuous porous polyurethane layer (b) can be maintained. However, in order to increase the adhesiveness between the continuous porous polyurethane layer (b) and the finished polyurethane coating (c), it is also necessary to use a paint that uses an organic solvent having a certain degree of solubility. Therefore, as the organic solvent used as the coating material, it is preferable to use a mixed solvent having a large solubility and a small solubility in the polyurethane forming the continuous porous polyurethane layer (b). As described above, in order to obtain a silver-tone artificial leather having open pores of 0.5 μm to 35 μm on the surface of the continuous porous polyurethane layer (b), after the finish polyurethane coating (c) is formed, Since the hole diameter is slightly smaller,
The diameter of the open pores on the surface of the communicating porous polyurethane layer (b) before forming the finished polyurethane coating (c) is 5 μm to
This means that the range of 40 μm is appropriate.

A conventional coating method can be adopted as the coating method, but a gravure coating machine, a doctor knife coater and the like are preferable. The coating amount is within the range of the conventional artificial leather finish coating, and the solid film thickness is 3 g / m 2.
^{2 to} 20 g / m ² , preferably 5 g / m ^{2 to} 10 g / m
² The finished polyurethane coating (c) can be colored with pigments, dyes, etc. to improve the costume. Further, since the silver-tone artificial leather having the open pores of the present invention has air permeability from the front surface to the back surface, when it is used as a shoe upper material, clothing, etc., water such as rain may enter. Therefore, it is important to add a water repellent agent to the finished polyurethane film (C) to impart water repellent property. Permanent water repellent property can be achieved by using a fluorine-modified polyurethane as the finishing polyurethane film (c). Here, as the water repellent, a urethane-modified fluorine-based water repellent having excellent compatibility with polyurethane [Crisbon Assister FX-3, manufactured by Dainippon Ink and Chemicals, Inc.]
And the like. Further, as the fluorine-modified polyurethane, Rezaroid FF411 manufactured by Dainichiseika Kogyo Co., Ltd.
0, the same FF 4115, and the like. In addition, it can be characterized by adding an antioxidant, a fungicide, an ultraviolet absorber, etc. to the finishing polyurethane film (c).

The silver-finished artificial leather of the present invention is permeable to NOx gas and the like because it has breathability, and there is a concern that the discoloration of polyurethane may occur. In particular, the polyurethane forming the continuous porous polyurethane (b) is
Generally, polyurethane synthesized from aromatic diisocyanate is often used. Therefore, the polyurethane used for the finishing polyurethane coating (c) is a polyurethane with little discoloration, for example, a polyurethane synthesized from an aliphatic diisocyanate such as 1,6-hexane diisocyanate, or isophorone diisocyanate,
Polyurethanes synthesized from alicyclic diisocyanates such as 4,4'-methylenebis (cyclohexyl isocyanate) are preferred. In the present invention, the polyurethane constituting the finished polyurethane coating (c) deeply covers the pore walls of the open pores formed by the communicating porous polyurethane layer (b), and therefore acts more effectively in preventing discoloration. Become.

In the present invention, in order to enhance the costume effect on the surface, various patterns can be applied by an embossing roll, which is usually performed in the production of artificial leather. The embossing step can be performed before, after, or after forming the open pores, after forming the finished polyurethane coating (c), or during the process. However, care must be taken when performing the hot embossing method because the open holes may be melted by heat and become smaller. Also, if performed before the open pore expression treatment,
It should be noted that the density of the dense part of the surface of the continuous porous polyurethane layer (b) may be further increased, which may make it difficult to open the pores.

By the method as described above, the surface of 0.5 μm
A silver-tone artificial leather having open pores with a diameter of 35 μm is produced. If the diameter of the open hole is less than 0.5 μm, the resistance against the passage of air becomes large, and the air permeability targeted by the present invention cannot be obtained, which is not preferable. On the other hand, if the diameter of the open holes exceeds 35 μm, it tends to get dirty when worn as a processed product such as shoe upper materials, shoe interior materials, and clothing,
Alternatively, it is not preferable because dirt enters the open hole and it is difficult to remove dirt even by washing. Since particles causing stains generally have a diameter of 30 μm or more, it is preferable that the diameter of the open pores on the surface of the silver-tone artificial leather be 30 μm or less.

Further, it is necessary that 200 or more, preferably 500 to 3,000, open holes are formed per cm ² on the surface of the silver-tone artificial leather of the present invention. Since the air permeability is determined by the size and number of the open holes, the number may be large if the diameter is small and small if the diameter of the open hole is large. However, since the moisture permeability depends largely on the number of open holes, the number of open holes needs to be 200 or more per 1 cm ² in order to achieve the object of the present invention. When the number of open holes is less than 200, it becomes difficult to obtain the moisture permeability of the present invention.

However, if the number of open holes is too large, problems such as antifouling property and abrasion resistance will occur. As an upper limit of the number of open holes, the area of the openings formed by the open holes is preferably 1% or less, more preferably 0.1% of the total area.
Is to be 0.3%. If it exceeds 1%, wear resistance and antifouling property are extremely lowered regardless of the size and number of open holes, which is not preferable.

The artificial leather with tone of silver of the present invention has the above-mentioned open pores having a diameter of 0.5 μm to 35 μm at ² per cm 2.
An artificial leather having 00 or more and the opening area of which is preferably 1% or less of the total area, and having an air permeability of 0.5 liter / cm ² · hr or more, preferably 2 liter / cm ² ·. hr-9 liters / cm ² · hr, water vapor transmission rate is 6 mg / cm ² · hr or more, preferably 8 mg / c
An artificial leather having m ² · hr to 14 mg / cm ² · hr. Both air permeability and moisture permeability are 0.5 liter / c
When it is less than m ² · hr and 6 mg / cm ² · hr, there is no difference compared to conventional artificial leather when used for shoe materials, clothing, etc., and it feels damp. In order to feel comfortable, the air permeability and moisture permeability of the present invention are required.

The structure of the present invention should satisfy the above-mentioned air permeability and moisture permeability in most cases. However, the fibrous material or the fibrous material and the polymeric elastic material constituting the silver-tone artificial leather of the present invention are used. Depending on the structure of the substrate (1) consisting of (3), it is possible that the air permeability and moisture permeability of the present invention are not satisfied. Conversely speaking, it is a necessary condition that the substrate structure according to the present invention provides the air permeability of 0.5 liter / cm ² · hr or more and the moisture permeability of 6 mg / cm ² · hr or more. For example, it is necessary that there is no structure that hinders air permeability and moisture permeability such as a solid film of a polymeric elastic material formed on the back surface of the substrate (a).

[0029]

EXAMPLES The present invention will be described in more detail with reference to examples. In the examples, "parts" and "%" are based on weight, and the characteristic measurement values were obtained by the following methods. Open hole diameter, number of holes Measured from images of scanning electron microscope [Asahi Kasei Co., Ltd.,
High-definition image analysis file system IP-1000 is used]. Area ratio of opening of open hole Measured from the image of scanning electron microscope [Asahi Kasei Co., Ltd.,
High-definition image analysis file system IP-1000 is used]. Air permeability According to the method of JIS P8117, "liter / cm ² · hr" is calculated from the time required for 50 cc of air measured using a Gurley densometer to pass through.
It is a value converted to the unit of. In value was measured according to the method of moisture permeability JIS K6549 expressed in "mg / cm ² · hr." The ash (mild seven) of antifouling tobacco is ground in a mortar and has a diameter of 36 mm, which is rotated 25 times by rotating the middle finger clockwise.
After rubbing it 25 times counterclockwise, wipe it with absorbent cotton,
The 5th grade is expressed as 1st to 5th grade without stain.

Example 1 <Preparation of Substrate-1> A basis weight of 330 g / m ² and a thickness of 1.0 m
18% on one side of an impregnated base fabric in which a non-woven fabric composed of polyester fibers of m is impregnated with a 13% concentration of polyester polyurethane (synthesized from P, P'-diphenylmethane diisocyanate) -dimethylformamide solution.
Polyurethane (the same as the above-mentioned polyurethane for impregnation) in a concentration-dimethylformamide solution was coated with a basis weight of 650 g / m ² , then water-immersed and solidified, washed with water and dried to prepare Substrate-1. The obtained substrate had a fibrous layer thickness of 1.0 mm and a porous polyurethane layer thickness of 280 μm.
It was composed of m.

<Open Pore Development Treatment> 40% of methyl ethyl ketone and 60% of dimethylformamide were formed on the surface of the substrate-1.
The mixed solution of was applied with a gravure coater (using a 110 mesh roll) at a pressure of 4 kg / cm ² and dried. When the surface of the obtained substrate-1 was observed with a scanning electron microscope, innumerable open pores of about 30 μm were formed.

<Formation of Finished Polyurethane Coating> Coating-1 prepared by the following composition is applied to the surface of the substrate subjected to the above-described open pore development treatment with a gravure coating machine (using a 110 mesh roll) and drying is repeated 3 times, Next, a pattern was applied in a pore-like pattern with a heating embossing roll, and then a paint-2 having the following composition was applied to the surface thereof with a gravure coater (using a 110 mesh roll) and dried to obtain artificial leather-1. (Paint-1) Crisbon NY320 [manufactured by Dainippon Ink and Chemicals, Inc.] 100 parts Howrack A5303 [manufactured by Dainippon Ink and Chemicals, Inc.] 30 parts Howrack A1008 mat [manufactured by Dainippon Ink and Chemicals, Inc.] 30 Part Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts (Paint-2) Howruck A3454 [Dainippon Ink and Chemicals, Inc.] 100 parts Howrack A1008 mat [Dainippon Ink and Chemicals, Inc.] 20 parts Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts

The artificial leather-1 thus obtained had a white surface and had open pores with a diameter of about 13 μm on the surface and paint on the pore walls.
Approximately 1,700 pieces / cm ^{2 when} covered with 1 and paint- ²
It was present and the area of the open part was equivalent to 0.23% of the total area. Both the air permeability and the water vapor transmission rate were superior to those of the conventional silver-tone artificial leather, and were less likely to stain. The characteristic values of the obtained artificial leather-1 are shown in Table 1.

Example 2 <Preparation of Substrate-2> A non-woven fabric made of a mixed fiber of 75% fiber and 25% rayon fiber obtained by dividing a divisible fiber in which polyester and 6-nylon are alternately adjacent to each other (300 g of basis weight). / M ² , thickness 1.3 mm), 13% concentration of polyester / polyether polyurethane (P, P'-
(Synthesized from diphenylmethane diisocyanate) -A dimethylformamide solution impregnated with a 20% concentration of polyurethane (the same as the above-mentioned polyurethane for impregnation) -dimethylformamide solution
After coating with a basis weight of 00 g / m ² , it was immersed in water for coagulation, washed with water, and dried to prepare Substrate-2. The obtained substrate had a fibrous layer thickness of 1.3 mm and a porous polyurethane layer thickness of 210 μm.

<Open Pore Development Treatment> On the surface of the substrate-2, 30% of methyl ethyl ketone and 70% of dimethylformamide were formed.
The mixed solution of was applied with a gravure coater (using a 110 mesh roll) at a pressure of 3 kg / cm ² and dried. When the surface of the obtained substrate-2 was observed with a scanning electron microscope, innumerable open pores of about 25 μm were formed.

<Formation of Finished Polyurethane Coating> Coating-3 prepared with the following composition was applied to the surface of the above-mentioned substrate subjected to the open pore development treatment with a gravure coating machine (using a 110 mesh roll) and drying was repeated twice, Next, a paint-4 having the following composition was applied to the surface by a gravure coater (using a 110-mesh roll), drying was repeated twice, and a heating embossing roll was used to apply a blood-skin pattern to obtain artificial leather-2. . (Paint-3) Crisbon NY320 [manufactured by Dainippon Ink and Chemicals, Inc.] 100 parts Howlac A5303 [manufactured by Dainippon Ink and Chemicals, Inc.] 30 parts Howrack A1008 mat [manufactured by Dainippon Ink and Chemicals, Inc.] 30 Part Crisbon Assister FX3 (water repellent) [manufactured by Dainippon Ink and Chemicals, Inc.] 2 parts Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts (Paint-4) Howruck A3454 [Dainippon Ink and Chemicals Inc.] Made 100 parts Howlac A1008 Matte [manufactured by Dainippon Ink and Chemicals, Inc.] 20 parts Crisbon Assister FX3 (water repellent) [manufactured by Dainippon Ink and Chemicals, Inc.] 2 parts Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethyl Formamide 10 parts

The artificial leather-2 thus obtained had a white surface and had open pores with a diameter of about 10 μm on the surface and paint on the pore walls.
Approximately 2,200 pieces / cm ^{2 when} covered with 3 and paint-4
It was present and the area of the open part was equivalent to 0.17% of the total area. Both the air permeability and the water vapor transmission rate were superior to those of the conventional silver-tone artificial leather, and the stain-resistant and water-repellent material was large. The characteristic values of the obtained artificial leather-2 are shown in Table 1.

Example 3 <Open Pore Generating Treatment> Methyl ethyl ketone 30 was formed on the surface of the substrate-2 prepared in Example 2 before the open pore developing treatment.
%, 70% dimethylformamide mixed solution with a gravure coating machine (using a 200 mesh roll) at 5 kg / cm ²
It was applied under the pressure of and dried. When the surface of the obtained Substrate-3 was observed with a scanning electron microscope, innumerable open pores of about 15 μm were formed.

<Formation of Finished Polyurethane Coating> Example 2
A gravure coating machine (using a 200 mesh roll) on the surface of the base material on which the above-described coating material-3 prepared in 1) has been subjected to open pore development treatment
Repeat coating and drying 3 times, then apply paint-5 of the following composition to the surface with a gravure coating machine (using a 200 mesh roll), repeat drying 2 times, and apply a bloody tone pattern with a heating embossing roll. Then, artificial leather-3 was obtained. (Paint-5) Rezaroid LU4180SF (fluorine modified polyurethane) [manufactured by Dainichiseika Kogyo KK] 100 parts Crisbon Assister FX3 (water repellent) [manufactured by Dainippon Ink and Chemicals, Inc.] 2 parts

The obtained artificial leather-3 had a white surface, and the surface had open pores with a diameter of about 7 μm, and the pore wall had paint-3.
There was about 3,100 pieces / cm ² covered with the paint-5, and the area of the open part was equivalent to 0.12% of the whole area. Both the air permeability and the water vapor transmission rate were superior to those of the conventional silver-tone artificial leather, and the stain-resistant and water-repellent material was large. Obtained artificial leather-
The characteristic values of No. 3 are shown in Table 1.

Example 4 A coating 6 prepared with the following composition was applied to the surface of the substrate-2, which had been subjected to the open pore development treatment prepared in Example 2, by a gravure coating machine (1
Application and drying are repeated twice with a 10 mesh roll), and then paint-4 prepared in Example 2 is applied to the surface with a gravure coater (using a 110 mesh roll) and drying is repeated twice. Artificial leather-4 was obtained by patterning with a heating embossing roll in a bloody tone. (Paint-6) Crisbon NY320 [manufactured by Dainippon Ink and Chemicals, Inc.] 100 parts Howruck A5303 [manufactured by Dainippon Ink and Chemicals, Inc.] 30 parts Howrack A1361 [manufactured by Dainippon Ink and Chemicals, Inc.] 2 parts Howlac A1008 Mat [Dainippon Ink and Chemicals, Inc.] 30 parts Crisbon Assister FX3 (water repellent) [Dainippon Ink and Chemicals, Inc.] 2 parts Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts

The obtained artificial leather-4 had a uniform gray color even though the porous polyurethane layer was white, and the surface thereof had open pores in exactly the same state as the artificial leather-2 obtained in Example 2. Was formed, and the characteristic value was about the same as the artificial leather-2. The characteristic values of the obtained artificial leather-4 are shown in Table 1.

Comparative Example 1 The coating material-1 prepared in Example 1 was applied to the surface of the substrate-1 prepared in Example 1 (one having no open pore developing treatment) by a gravure coating machine (using a 110 mesh roll). , Drying 3 times, then patterning with a heating embossing roll in a pore-like pattern, and further coating the paint-2 prepared in Example 1 on the surface with a gravure coating machine (using a 110 mesh roll) and drying, Artificial leather-5 was obtained. The obtained artificial leather has a white surface, and at first glance, the artificial leather obtained in Example 1
1 It is the same, but when observed with a scanning electron microscope, there are no open pores and there is no air permeability,
The moisture vapor transmission rate was similar to that of conventional artificial leather. The characteristic values of the obtained artificial leather-5 are shown in Table 2.

Comparative Example 2 The surface of the artificial leather-5 prepared in Comparative Example 1 was mechanically treated with a needle to form 9 holes per 1 cm ² . The diameter of the open pores on the surface was 150 μm, and although it had air permeability, it had moisture permeability comparable to that of conventional artificial leather. When it was actually molded into shoes and worn, it was easy to get dirty, and even if it was washed, it hardly entered because the dirt had entered the open holes. Table 2 shows the characteristic values of the artificial leather-6 having the needle holes.
Shown in

Comparative Example 3 A non-woven fabric made of polyester fiber having a basis weight of 330 g / m ² and a thickness of 1.0 mm was used, and the same procedure as in Example 1 was performed on one side of the impregnated substrate.
The dimethylformamide solution was coated with a basis weight of 90 g / m ² , then water-immersed and solidified, washed with water, and dried to give a substrate-3.
It was created. The obtained substrate has a fibrous layer thickness of 1.0.
mm, and the thickness of the porous polyurethane layer was 38 μm. On the surface of the base body-3, an open pore developing treatment, a finish polyurethane film formation and a patterning were applied in the same manner as in Example 1 to obtain artificial leather-7. On the surface of the obtained artificial leather-7, there were about the same number of open pores having the same diameter as the surface of the artificial leather-1, and the air permeability and the moisture permeability were the same as those of the artificial leather-1, When the surface was not smooth and the convex portions due to fluff were conspicuous, and when it was still elongated, the fibrous skin of the non-woven fabric was conspicuous, impairing the commercial value. Table 2 shows the characteristic values of the artificial leather-7.

Comparative Example 4 A mixed solution of 30% of methyl ethyl ketone and 70% of dimethylformamide was applied to the surface of the substrate-1 (having no open pore developing treatment) prepared in Example 1 by a gravure coater (roll of 70 mesh). Was used) and was applied and dried at a pressure of 4 kg / cm ² . When the surface of the obtained substrate-1 was observed with a scanning electron microscope, innumerable open pores of about 45 μm were formed. On the surface of the substrate-1 which had been subjected to the open pore expressing treatment, a finishing polyurethane film was formed and patterned in the same manner as in Example 1 to obtain artificial leather-8. About 850 open pores having a diameter of about 40 μm were present on the surface of the obtained artificial leather-8, and the area of the open portion corresponded to 1.07% of the total area. As shown in Table 2, both the air permeability and the water vapor transmission rate were excellent as compared with the conventional artificial leather, but stains tended to adhere, and when actually molded into shoes and worn, It was easy, and even if it was washed, the dirt did not completely remove because it entered the open holes. In addition, it was easily worn, the diameter of the open hole became large, and the stain became severe with the wearing time.

Example 5 A mixed solution of 50% of methyl ethyl ketone and 50% of dimethylformamide was applied to the surface of the substrate-1 prepared in Example 1 (one having no open pore developing treatment) by a gravure coating machine (200).
A roll of mesh having a mesh portion of 60% was used), and was applied and dried at a pressure of 4 kg / cm ² .
When the surface of the obtained substrate-1 was observed with a scanning electron microscope, innumerable open pores of about 15 μm were formed. On the surface of the substrate-1 which has been subjected to this open pore developing treatment, Example 1
A finished polyurethane film was formed and a pattern was applied in the same manner as in 1. to obtain artificial leather-9. Obtained artificial leather-
There were about 630 open pores having a diameter of about 6 μm on the surface of No. 9, and the area of the open portion corresponded to 0.02% of the total area. As shown in Table 1, both the air permeability and the water vapor permeability were superior to those of the conventional artificial leather.

Comparative Example 5 On the surface of Substrate-1 prepared in Example 1 (no open pore developing treatment), a mixed solution of 70% methyl ethyl ketone and 30% dimethylformamide was applied to a gravure coating machine (200).
A roll of mesh having a mesh portion of 60% was used) and applied and dried at a pressure of ² kg / cm ² .
When the surface of the obtained substrate-1 was observed with a scanning electron microscope, open pores of about 9 μm were scatteredly formed. On the surface of the substrate-1 which had been subjected to this open pore expressing treatment, a finishing polyurethane film was formed and patterned in the same manner as in Example 1 to obtain artificial leather-10. Obtained artificial leather-
There were about 150 open pores having a diameter of about 3 μm on the surface of No. 10, and the area of the open portion was equivalent to 0.001% of the total area. Table 2 shows the air permeability and moisture permeability.
As shown in, 0.1 liter / cm ² · hr, 3.7
It was mg / cm ² · hr, and when it was actually molded into shoes and worn, it felt “steamy” and no difference from conventional artificial leather was felt.

[0049]

[Table 1]

[0050]

[Table 2]

Test Example <Wearing test after shoe molding> Artificial leather-1 produced in Example 1, artificial leather-2 produced in Example-2, and artificial leather-5 produced in Comparative Example-1, and The artificial leather-6 prepared in Comparative Example-2 was used as a shoe upper material and molded into tennis shoes in the same process, and these shoes were worn on the right foot and the left foot at the same time.
After jogging at a distance of m, the temperature and the humidity inside the worn shoes were measured after 10 minutes. This test was carried out by 10 people, and the average value was compared.
1 and artificial leather-2, the temperature and humidity in the shoes of the shoes molded are artificial leather-5 and artificial leather-6.
In comparison with that of shoes molded in, each 1 ℃, 20%
The RH was low, and the wearer was able to fully feel the difference in stuffiness.

[0052]

EFFECTS OF THE INVENTION According to the present invention, when used and worn for shoes, clothing, etc., it has less "stuffy feeling", less stains, and a smooth and dignified surface appearance and abrasion resistance. A new artificial leather with a silver tone can be obtained.

Claims (4)

[Claims] 1. A thickness of 50 μm to 30 on one surface of a substrate (a) composed of fibrous material or fibrous material and elastic polymer.
A continuous porous polyurethane layer (b) of 0 μm is formed,
In a silver-tone artificial leather having a finish polyurethane coating (C) formed on the surface thereof, the surface has a thickness of 0.5 μm to 35 μm.
There are 200 or more open pores with a diameter of μm per 1 cm ² , and the finish polyurethane coating (c) is formed so as to cover the pore walls of the open pores and reach the inside of the communicating porous polyurethane layer (b). Is 0.5 liter / cm ² · hr
As mentioned above, the artificial leather with a silver tone having a moisture permeability of 6 mg / cm ² · hr or more. 2. The silver-finished artificial leather according to claim 1, wherein the finished polyurethane coating (c) has water repellent property. 3. The silver-finished artificial leather according to claim 1, wherein the finish polyurethane coating (c) is made of fluorine-modified polyurethane. 4. The thickness of 50 μm to 30 on one surface of a substrate (a) composed of fibrous material or fibrous material and elastic polymer.
0 μm continuous porous polyurethane layer by wet method (b)
In the method for producing a silver-tone artificial leather by forming a finished polyurethane coating (C) on the surface of the same, a polyurethane good solvent, a poor solvent, Either a mixed solvent of a good solvent and a poor solvent or a mixed solvent of a good solvent and a non-solvent is applied by a gravure mesh roll to generate open pores having a diameter of 5 μm to 40 μm on the surface, and then a finish polyurethane coating (ha And forming the open pores of the continuous porous polyurethane layer (b) in the finished polyurethane coating (c) as open pores. .