JPH06264371A - Brained artificial leather excellent in design effect and its production - Google Patents

Abstract

PURPOSE:To obtain an oil-up and grained artificial leather capable of completely solving conventional disadvantages in using and wearing for applications such as shoes or clothes and having sufficient surface strength. CONSTITUTION:This grained artificial leather excellent in design effects is obtained by coating one surface of a substrate (a) composed of a fibrous substance or the fibrous substance and a polymeric elastic body with a porous polyurethane layer (b) having 50-400mum thickness and then forming a finish polyurethane film (c) on the surface thereof. In the artificial leather, >=500 opened pores having 0.5-80mum diameter are present per cm<2> in the interface on the side of the finish polyurethane film (c) of the porous polyurethane layer (b). A wax having 40-100 deg.C melting point or a mixture consisting essentially of the wax is present in the opened pores so as to be embedded therein. The bonding area in the interface between the porous polyurethane layer (b) and the finish polyurethane film (c) is >=70% based on the total area. Furthermore, this method for producing the grained artificial leather is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention, when used for applications such as shoes, clothes and bags, changes the lightness of the color of the stretched portion and the compressed portion when it is bent, and causes a natural unevenness. The present invention relates to a silver-tone artificial leather having an excellent effect and a method for producing the same.

[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 silver type is generally widely used for shoes, balls, clothes, bags, furniture and the like. These silver-tone artificial leathers have been made various efforts such as imitating the surface formation of natural leathers to change the color, pattern, etc. according to the application, and efforts have been made to improve the design. Among them, the surface finish of oil-like natural leather, which causes a change in the lightness of the color due to the movement of the oil inside the leather when bent and causes natural unevenness, is desired for each application, and various studies have been made in the past. It was However, the conventional ones have a weak surface strength and are far from practical use.

Among them, the one in which a mixture of wax and a cellulosic resin is applied to the surface of the leather substitute has poor adhesiveness to the surface resin of the leather substitute, and is dropped or peeled off during use. Not only for shoes, but also for furniture, clothing, and bags, there was no practical strength. These materials utilize a phenomenon in which a mixture of wax and a cellulosic resin is deformed, such as bent, causing minute cracks to whiten and change in brightness, so that these materials are formed on the outermost surface. If so, naturally, it will fall into powder. Further, even if a strong protective resin film is formed on the surface of the wax and cellulosic resin layer, peeling occurs from the interface between the surface of the leather substitute and the layer of the wax and cellulosic resin mixture.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide shoes,
An object of the present invention is to provide an oil-up-like silver-tone artificial leather which completely solves the conventional drawbacks when used or worn for clothing and the like and has sufficient surface strength.

[0005]

According to the present invention, a porous polyurethane layer (b) having a thickness of 50 μm to 400 μm is formed on one surface of a substrate (a) made of fibrous material or a fibrous material and a polymeric elastic material. In the artificial leather with a silver tone formed by forming a finishing polyurethane film (C) on the surface,
At the interface of the porous polyurethane layer (b) on the side of the finished polyurethane coating (c), there are 500 or more open pores having a diameter of 0.5 μm to 80 μm per cm ² , and the melting point of the open pores is 40 ° C. A wax at 100 ° C. or a mixture containing the wax as a main component is present so as to be embedded, and the adhesion area at the interface between the porous polyurethane layer (b) and the finished polyurethane coating (c) is 70% or more of the total area. It is an artificial leather with a silver tone that has an excellent design effect.

Further, according to the present invention, a porous polyurethane layer (b) having a thickness of 50 μm to 400 μm is formed on one surface of a substrate (a) made of a fibrous material or a fibrous material and a polymeric elastic body by a wet method. Then, in the method for producing an artificial leather by forming a finished polyurethane film (c) on the surface thereof, the skin layer having a high density on the surface of the porous polyurethane layer (b) is mechanically ground to have a diameter of 0. After opening an opening having a diameter of 5 μm to 80 μm, an organic solvent solution of a wax having a melting point of 50 ° C. to 100 ° C. or a mixture mainly composed of the wax is applied so as to be embedded in the opening, followed by finishing. A method for producing a silver-tone artificial body having an excellent design effect, which comprises forming a polyurethane film (C).

Furthermore, according to the present invention, a porous polyurethane layer (b) having a thickness of 50 μm to 400 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. Then, in the method for producing an artificial leather by forming a finish polyurethane coating (C) on the surface of the porous polyurethane layer (B), a good solvent, poor solvent, good solvent and poor solvent of polyurethane Either a mixed solvent or a mixed solvent of a good solvent and a non-solvent is applied with a gravure mesh roll and the diameter is 0.5 μm to 80 μm on the surface.
After generating open holes of m, the melting point is 50 ° C to 100 ° C.
Of the wax or a mixture mainly composed of the wax,
In the method for producing a silver-tone artificial leather having an excellent design effect, an organic solvent solution is applied so as to be embedded in the open holes, dried, and then a finished polyurethane film (c) is formed.

The fibrous material constituting the artificial leather of the present invention is
It is a conventionally known woven fabric, knitted fabric, non-woven fabric, or the like made of natural fiber, regenerated fiber, or synthetic fiber. Cotton as a natural fiber,
Examples include hemp, wool, and silk, examples of recycled fibers include rayon and acetate, and examples of synthetic fibers include polyester, nylon, acrylic, and the like. With synthetic fibers, the single yarn fineness is 0.5.
It is preferable to use ultrafine fibers having a denier or less, preferably 0.01 denier to 0.2 denier in order to enhance the texture and elegance of the artificial leather of the present invention.

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,
Or after impregnating the fiber as an organic solvent solution,
Substrate which is solidified and consists of fibrous material and elastic polymer (a)
It is said that

For the porous polyurethane layer (b) formed on one surface of the substrate (a) composed of these fibrous materials or the fibrous material and the polymer elastic material, any conventionally known polyurethane can be applied. Those formed by a conventionally known molding method can be applied. For example, an organic solvent solution of polyurethane is coated on one side of a substrate (a) composed of fibrous material or fibrous material and elastic polymer,
A method of causing coagulation in a coagulation bath that is a non-solvent of polyurethane and miscible with an organic solvent in which polyurethane is dissolved, or an organic solvent solution of polyurethane, or a W / O type in which water is finely dispersed in a dispersion liquid. After coating the emulsion of 1) on one surface of a substrate (a) composed of a fiber or a fiber and a polymer elastic material, the organic solvent is selectively evaporated to solidify the polyurethane.

The thickness of the porous polyurethane layer (b) of the present invention is required to have a certain thickness so that the wax or the mixture containing the wax as a main component is present in the open pores, and the abrasion resistance is high. It is also necessary to obtain the smoothness, surface smoothness, cushioning and volume feeling, and the appropriate thickness is 5
0 μm to 400 μm, preferably 70 μm to 300 μm
Is. If the thickness is less than 50 μm, it becomes difficult to uniformly put the wax or the mixture mainly composed of the wax into the open pores, and the fibrous texture appears on the surface, resulting in a smooth feeling on the surface. Is not preferable because it is difficult to obtain On the other hand, when the thickness is more than 400 μm, it is not preferable because it becomes a rubber-like artificial leather and the productivity is lowered.

In the present invention, the porous polyurethane layer (b)
In order to uniformly put the wax or the mixture containing the wax as a main component in the open pores, it is necessary to remove the dense layer on the outermost surface of the porous polyurethane layer (b) to open the open pores. The diameter of the opened open hole is 0.5.
μm to 80 μm, preferably. 10 μm to 50 μm, the number is 500 or more per 1 cm ² , preferably 5,000 to 30,000, and the area of the open portion is less than 30% of the total area, preferably 0.1% to 1
0%, that is, the area that is not open is 7 of the total area
It should be 0% or more, preferably 90% to 99.9%. If the diameter of the open hole is less than 0.5 μm,
It is not preferable because it is difficult to add a wax or a mixture containing the wax as a main component, and the change in brightness upon bending, which is the object of the present invention, cannot be obtained. On the other hand, if the diameter of the open pores exceeds 80 μm, if the number of open pores is small, the change in brightness during bending, which is the object of the present invention, cannot be obtained, and if the number is large, the porous polyurethane layer (b) The adhesion area with the finished polyurethane coating (C) becomes smaller,
This is not preferable because the finished polyurethane coating (C) may peel off. Also, the number of open holes is 1 cm
If the number is less than 500 per ^{2, the} change in brightness during bending is small and the object of the present invention cannot be achieved. In addition to satisfying the above conditions, in order to obtain sufficient interfacial adhesion between the porous polyurethane layer (b) and the finished polyurethane coating (c), the area that is not opened, that is, the adhesion area is 70% of the total area. Must be at least%. If it is less than 70%, there is a problem that the finished polyurethane coating (c) may peel off when worn as a product such as shoes, which is not preferable.

Since the porous polyurethane layer (b) is colored with a dye, a pigment or the like, it is possible to make the change in the lightness at the time of bending, which is the object of the present invention, more effective. As a coloring method, a method of directly mixing a colorant into a solution for forming the porous polyurethane layer (b), a method of coloring by forming after the formation of the porous polyurethane layer (b), a porous polyurethane layer (b) described later ) A method of adding a coloring agent such as a dye into a solvent for forming open pores on the surface, a method of coloring while leaving the open pores on the surface after the formation of the open pores, a wax, or mainly the wax There are a method of adding a colorant to the mixture, a method of adding a colorant to the finished polyurethane film (c), a method of coloring by coloring after forming the finished polyurethane film (c), and the like. With the above combination, the design appearance of the present invention can be further enhanced.

As a method of opening the open holes, there is a method of removing the dense layer of the porous polyurethane layer (b) by a grinder using sandpaper. Also in this method, the diameter of the open hole is 0.5 μm to 80 μm.
However, in this method, it may be difficult to uniformly grind the entire surface due to uneven thickness of the base body (a), and when lightly grinded, a small diameter of 20 μm or less is opened, but there is also a part that is not opened. Therefore, it is necessary to grind away the thickness so that the entire surface is opened. In this case, a relatively large diameter of 10 μm or more, preferably 2
Open pores of 0-50 μm are obtained.

As another method of opening the pores, a good solvent of polyurethane on the surface of the porous polyurethane layer (b),
Either the poor solvent, the mixed solvent of the good solvent and the poor solvent, or the mixed solvent of the good solvent and the non-solvent is applied by a gravure mesh roll. Here, the good solvent of polyurethane means a good solvent capable of dissolving the polyurethane actually used, for example, dimethylformamide in the case of a polyurethane synthesized from an aromatic organic diisocyanate,
Examples include polar solvents such as tetrahydrofuran and dioxane. The poor solvent for polyurethane is a solvent that can swell but does not dissolve the polyurethane actually used, and examples thereof include ketones such as methyl ethyl ketone, alcohols such as isopropyl alcohol, and aromatic solvents such as toluene. . The non-solvent of polyurethane does not dissolve or swell the polyurethane 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 expressed. 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. Also,
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 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 high, the diameter of the obtained open hole is large, and if the coating pressure is low, the diameter of the obtained open hole is small. As described above, 0.5 μm to 80 μm, preferably 5 μm to 40 μm of the present invention is formed on the surface of the porous polyurethane layer (b) by selecting an appropriate solvent, selecting a gravure mesh roll, and optimizing the coating pressure.
Open pores with a diameter of μm can be developed.

On the surface of the porous polyurethane layer (b), 0.
After the open pores of 5 μm to 80 μm are developed, a wax or a mixture containing the wax as a main component is applied to the surface thereof in an organic solvent, dried and substantially buried in the open pores. The wax has a melting point of 40 ° C to 10 ° C.
A natural product or a synthetic product at 0 ° C, preferably 50 ° C to 80 ° C is used. When the one having a melting point of less than 40 ° C. is used, when the wax is used in a season with high temperature such as summer, or in a place with high room temperature, the wax becomes in a molten state and the brightness change at the time of bending which is the object of the present invention. Is not preferable because it cannot be obtained. On the other hand, when a wax having a melting point of more than 100 ° C. is used, it is not preferable because the one whose brightness has once changed during bending is difficult to return to the original. Melting point: 40 ° C-100
By using wax at ℃, it is very effective when used as a product such as shoes because it can be easily restored to its original brightness by heating it with a hair dryer etc. There is also a major feature of the present invention.

Here, as a concrete example of the natural wax,
Animal fats and oils such as beef tallow, lard, and whale fat are included.
Since the synthetic wax is used in combination with a polyurethane resin, a polyurethane group-modified wax having an affinity for polyurethane is preferable. Specific examples of the synthetic wax include urethane group-modified polyester,
Examples include urethane group-modified polyethers. Furthermore, examples of the mixture containing wax as a main component include a mixture of the above-mentioned natural wax and synthetic wax and a resin having brittleness such as a nitrocellulose resin. These waxes form a transparent film when applied and dried as an organic solvent solution, but they are crushed and whitened when mechanical force such as bending is applied at room temperature, and become transparent again when heated while maintaining that state. Phenomenon occurs. Since this principle is used, the wax or the mixture containing the wax as a main component must be appropriately selected in advance.

A wax or a mixture containing wax as a main component is dissolved in an organic solvent and coated as a paint on the surface of the porous polyurethane layer (b) having the above-mentioned open pores. Those that do not dissolve the porous polyurethane layer (b) are preferable. Because, when the solubility of the porous polyurethane layer (b) is large,
This is because the pore wall is melted and the open pores are closed before the coating material enters the open pores formed in advance on the surface of the porous polyurethane layer (b). The smaller the solubility, the more the open pores developed on the surface of the porous polyurethane layer (b) can be maintained, and the paint can be put into the open pores. Also, a wax having a melting point of 40 ° C. to 100 ° C., or a mixture composed mainly of wax and an organic solvent is applied and then the organic solvent is evaporated,
In this case, when heated and evaporated, the wax, or a mixture containing wax as a main component, is in a molten state after evaporation, so that the wax or the wax is mainly contained in a portion in contact with the surface of the substrate such as a guide roll of a dryer. The resulting mixture becomes unfavorable such as adhesion. Therefore, the heating evaporation condition is preferably drying at 40 ° C. or lower, and for that purpose, a highly volatile organic solvent is preferable. From the above,
As the organic solvent constituting the coating material, if the porous polyurethane layer (b) is synthesized from aromatic diisocyanate, it is preferable to use a solvent such as toluene, ethyl acetate or methanol which has a high volatility and does not dissolve polyurethane.

The wax, or a coating composed of a mixture mainly composed of wax and an organic solvent, is applied onto the porous polyurethane layer (b) by a general application method such as a gravure coating machine and a doctor knife coater. As for the coating amount, if it is applied to the surface of the porous polyurethane layer (b) other than the open pores, it will interfere with the adhesion with the finished polyurethane coating (c), so the amount that enters the open pores is sufficient. A small amount is good. Therefore, the coating amount is specifically 5 g / m
^It is preferably about ^{2 to} 80 g / m ² . As a coating method,
In both cases, the higher the pressure of the coating machine, the easier it is to enter the open hole.
Further, in the case of heating for solvent drying, it is preferable to heat from the back surface side rather than from the front surface side because the coating material is easily guided into the open holes. Further, it is also effective to press the surface with a heating embossing roll after forming a finish polyurethane coating (C) described below in order to induce wax or a mixture mainly containing wax into the open holes.

After the wax or the mixture containing the wax as a main component is applied, a finished polyurethane film (c) is formed on the surface of the wax. As the polyurethane constituting the finished polyurethane coating (c), all known polyurethanes can be used, but considering the discoloration of the product, for example, they are synthesized from an aliphatic diisocyanate such as 1,6-hexanediisocyanate. Polyurethane, or isophorone diisocyanate, 4,4'-
Polyurethanes synthesized from alicyclic diisocyanates such as methylene bis (cyclohexyl isocyanate) are preferred. In addition, coloring agents such as pigments and dyes, water repellents, antioxidants, antifungal agents, and ultraviolet absorbers can be added to the finished polyurethane coating (c).

In the case of coloring the finished polyurethane coating (c), it is preferable to use a coloring agent having a small hiding property such as a dye or a transparent pigment as a wax in the lower layer of the finishing polyurethane coating (c) or a wax as a main component. It is preferable that the change in lightness due to the mixture is easily visible from the outside. Further, in order to impart abrasion resistance to the surface, it is possible to use polyurethane or the like having excellent abrasion resistance and laminate two or more kinds of polyurethane coatings (c). Furthermore, the design effect can be enhanced by applying a pattern print to the finished polyurethane coating (C). As a method for forming the finished polyurethane film (c), conventionally known methods such as a method using a gravure coater, a method of forming a polyurethane film on release paper and laminating and adhering it, a film formation by a spray method, and a direct coating method can be adopted.
The coating amount is in the range of the conventional finished polyurethane coating of artificial leather, that is, as a solid film thickness of 1 g / m ² to 10
0 g / m ^2, preferably 3g / m ² ~20g / m ² approximately.

In the present invention, in order to enhance the design effect of the surface, various patterns can be applied by an embossing roll as is usually done in the production of artificial leather. As the embossing step, it is preferable to form the finished polyurethane coating (c) after forming the finished polyurethane coating (c) to enhance the adhesive strength between the porous polyurethane layer (b) and the finished polyurethane coating (c). It is possible. However, care must be taken when the pattern is applied by the hot embossing method after the open pore developing treatment, because the open pores may be melted by heat and become smaller. If the treatment is performed before the open pore developing treatment, the density of the dense portion of the surface of the porous polyurethane layer (b) is further increased, and the open pore developing treatment may be difficult, so care must be taken. When making it smooth, it is possible to use a mirror surface roll instead of the pattern embossing roll.

By the method described above, the oil-up artificial leather of the present invention, whose brightness changes during bending, is manufactured. In this way, wax or a mixture mainly composed of wax was embedded in the open pores of the porous polyurethane layer (b), and the porous polyurethane layer (b) and the open pores were covered with the finishing polyurethane film (c). The artificial leather of the present invention, when folded or when mechanical force is applied, wax, or a mixture containing wax as a main component is whitened to increase its brightness as compared to other parts,
Natural brightness unevenness will occur on the surface and a high-quality design appearance will be obtained, and it can be used for various applications such as shoe uppers, clothing main bodies, clothing parts, bags, furniture sheets, vehicle seats, hats, It is possible to obtain a product having a natural unevenness which is not present in conventional artificial leather. In addition, this unevenness is
It is a reversible substance that recovers naturally if left unattended, and it completely recovers when heated with a hair dryer, etc., and unevenness occurs by bending again at room temperature, and its value is immeasurable. is there.

[0026]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the examples, "parts" and "%" are based on weight, and the characteristic measured values were obtained by the following methods. The diameter of the open hole,
The number of open holes is measured by a scanning electron microscope, and the adhesion area is calculated from the area of open holes.

Example 1 <Preparation of Substrate-1> A basis weight of 330 g / m ² and a thickness of 1.0 m
An impregnated base cloth in which a non-woven fabric made of polyester fiber of m is impregnated with 13% concentration of polyester-based polyurethane (synthesized from P, P'-diphenylmethane diisocyanate) -dimethylformamide solution (pigment added and toning in brown) 18% concentration of polyurethane (the same as the above-mentioned polyurethane for impregnation, to which the same pigment was added and toned in brown) -dimethylformamide solution was coated on one side of the above with a basis weight of 650 g / m ² ,
Substrate-1 was prepared by immersion coagulation, washing with water and drying. The obtained substrate had a brown surface, the thickness of the porous polyurethane layer was 280 μm, and the thickness of the fibrous layer was 1.0 mm.

<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 coating machine (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,
2,800 open pores of about 30 μm were formed per cm ² . The surface area of the porous polyurethane excluding the open pores was 98.0% based on the total area.

<Application of Wax> A solution of urethane-modified wax having a melting point of 50 ° C. to 80 ° C. dissolved in toluene on the surface of the substrate-1 which has been subjected to an open pore developing treatment [manufactured by Dainippon Ink and Chemicals, Inc.]. Howlac Clear U-14
00) was applied by a gravure coater (using a 200 mesh roll) and dried at room temperature twice. The amount of wax applied was 4.5 g / m ² .

<Formation of Finished Polyurethane Film> Coating-1 prepared by the following composition is applied to the surface of the substrate which has been subjected to the above-described open hole development treatment and wax coating by a gravure coating machine (using a 110 mesh roll) and dried. Repeat 3 times, then pattern with pores with a heating embossing roll, further apply paint-2 of the following composition on the surface with a gravure coater (using a 110 mesh roll), and repeat drying 3 times, artificial leather- Got 1. The total coating weight of the finished polyurethane coating was 9 g / m ² .

The obtained artificial leather-1 has a brown surface, and when bent or rubbed, the extension and compression of the surface are subtly changed in brightness to cause natural unevenness, resulting in high-grade oil up. It has a design appearance similar to that of natural leather. When this artificial leather-1 was exposed to a dryer at 100 ° C for 15 seconds, the original brightness was restored. When casual shoes were made using this artificial leather as a shoe upper material, the adhesive strength with the sole was as strong as 2.8 kg / cm, and a pattern with a natural unevenness was formed, making shoes using conventional artificial leather. Compared to the casual shoes, it had a completely different natural feel and a luxurious feel.

(Paint-1) Crisbon NY320 100 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Howlac Brown U1355 30 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts (Paint-2) 100 parts of Howlac A3454 [manufactured by Dainippon Ink and Chemicals, Inc.] 5 parts of Haurak A1008 [manufactured by Dainippon Ink and Chemicals] isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts

Example 2 <Preparation of Substrate-2> 75% ultrafine fibers (average single yarn denier = 0.1 denier) obtained by dividing divisible fibers in which polyester and 6-nylon are alternately adjacent to each other and rayon fibers. (Single yarn denier = 0.8 denier) Non-woven fabric composed of mixed fiber with 25% (Basis weight 300 g / m ² , thickness 1.3 m
m) a polyester / polyether type polyurethane (synthesized from P, P'-diphenylmethane diisocyanate) of 13% concentration-dimethylformamide solution (a pigment is added to adjust the color to green) 20% concentration of polyurethane (the same as the above-mentioned polyurethane for impregnation, to which the same pigment was added and adjusted to a green color) -dimethylformamide solution was coated on one surface with a basis weight of 400 g / m ² , and then water was applied. Substrate-2 was prepared by dipping and solidifying, washing with water and drying. The obtained substrate had a green surface, the thickness of the porous polyurethane layer was 210 μm, and the thickness of the fibrous layer was 1.3 mm.

<Open Pore Generating 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 200 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, 3,600 open pores of about 25 μm were formed per cm ² . The surface area of the porous polyurethane excluding the open pores was 98.2% based on the total area.

<Application of Wax> A solution of urethane-modified wax having a melting point of 50 ° C. to 80 ° C. dissolved in toluene on the surface of the substrate-2 which has been subjected to open pore developing treatment [manufactured by Dainippon Ink and Chemicals, Inc.]. Howlac Clear U-14
00] was applied by a gravure coater (using a 200 mesh roll) and dried at room temperature twice. The amount of wax applied was 4.6 g / m ² .

<Formation of Finished Polyurethane Film> On the surface of the release paper on which the blood streak is formed, the paint-3 prepared by the following composition is coated at a basis weight of 100 g / m ² and dried. The coating composition for adhesion prepared with the above composition was coated with a basis weight of 70 g / m ² and dried, and the substrate-2 coated with wax was laminated so as to adhere to the wax coating side. After leaving the adhesive until it had sufficient strength, the release paper was peeled off to obtain artificial leather-2.

The obtained artificial leather-2 has a green surface, and when it is bent or rubbed, the extension and compression of the surface are subtly changed in lightness to cause natural unevenness, resulting in a high-grade oil. It has a design appearance that is similar to that of up-quality natural leather. In addition, this artificial leather-2 100 ℃
After being exposed to the dryer for 15 seconds, the original brightness was restored.
When casual shoes were made using this artificial leather as a shoe upper material, the adhesion strength with the sole was 3.5 kg.
/ Cm and a pattern with a natural unevenness was included, and compared to a casual shoe made of conventional artificial leather, the natural feeling was completely different and it was a high-class feeling.

(Paint-3) Resamine NPU5NL 100 parts [manufactured by Dainichiseika Kogyo KK] Howlac A1320 Green 5 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Isopropyl alcohol 20 parts Toluene 20 parts Dimethylformamide 20 parts ( Adhesive paint) Crisbon TA265 50 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Crisbon TA290 50 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Crisbon Accel T 3 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Coronate 2094 12 parts [Nippon Polyurethane Industry Co., Ltd.] Methyl ethyl ketone 70 parts Dimethylformamide 30 parts

Example 3 The dense layer on the surface of the porous polyurethane layer of Substrate-2 whose surface was green in Example 2 was ground with 200 mesh sandpaper to expose the open pores therein. 40
Open holes with a diameter of μm to 60 μm per cm ² 2,40
After forming 0 (the surface area of the porous polyurethane excluding the open pores was 96.1% based on the total area), the urethane-modified wax having a melting point of 50 ° C. to 80 ° C. was added to toluene as in Example 1. A dissolved solution [manufactured by Dainippon Ink and Chemicals, Inc .; Haurak Clear U-1400] was applied by a gravure coating machine (using a 200 mesh roll) and dried at room temperature twice, and then a coating material prepared with the following composition -4 is operated in the same manner as in Example 1 for the gravure coating machine (110
Applying and drying with a mesh roll) 3 times,
Next, a pattern is applied in a pore-like pattern with a heating embossing roll, and then paint-2 is applied to the surface with a gravure coater (using a 110-mesh roll) and drying is repeated 3 times to produce artificial leather.
Got 3. The amount of wax applied was 5.2 g / m ² ,
The total coating weight of the finished polyurethane coating was 11 g / m ² .

The artificial leather-3 thus obtained had a green surface and had an adhesive force of 3 kg / cm or more between the porous polyurethane layer and the finished polyurethane film, and when it was bent or kneaded, the surface stretched and compressed. The lightness of the part slightly changed and natural unevenness was generated, giving the design an appearance similar to that of high-quality oil-up natural leather. In addition, when this artificial leather-3 was exposed to a dryer at 100 ° C. for 15 seconds, the original brightness was restored. When a handbag was made using this artificial leather, it was found that the handbag made of conventional artificial leather had a completely different natural feel and a superior luxury feel.

(Paint-4) Crisbon NY320 100 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Howlac A1320 Green 15 parts [manufactured by Dainippon Ink and Chemicals, Inc.] Isopropyl alcohol 50 parts Methyl ethyl ketone 40 parts Dimethylformamide 10 parts

Example 4 The dense layer on the surface of the porous polyurethane layer of Substrate-1 having a brown surface obtained in Example 1 was ground with 200 mesh sandpaper to expose the open pores therein to about 40 μm. ~
After forming 2,400 open pores with a diameter of 60 μm per cm ² (the surface area of the porous polyurethane excluding the open pores was 96.1% based on the total area), the melting point was the same as in Example 1. A solution of urethane-modified wax having a temperature of 50 ° C to 80 ° C dissolved in toluene [Dainippon Ink and Chemicals, Inc.
Manufactured by Howlac Clear U-1400) by a gravure coater (using a 200-mesh roll) and dried at room temperature twice, and then a paint-5 prepared with the following composition-5
Is coated on the surface of the release paper on which the blood streak is formed by the same operation as in Example 2 and dried, the adhesive coating material prepared in Example 2 is coated on the surface, and the dried surface is adhered to the wax coated side. So that After leaving it until the adhesive had sufficient strength, the release paper was peeled off to obtain artificial leather-4. The amount of wax applied is 4.3 g.
/ M ² , total coating amount of polyurethane coating is 75g
/ M ² .

The obtained artificial leather-4 had a brown surface, the adhesive force between the porous polyurethane layer and the finished polyurethane coating was 3 kg / cm or more, and when it was bent or kneaded, the stretched and compressed parts of the surface were formed. Subtly changed the lightness and caused natural unevenness, resulting in a design appearance similar to that of high-quality oil-up natural leather. In addition, if this artificial leather-4 is exposed to a dryer at 100 ° C. for 15 seconds,
It returned to its original brightness. When a furniture sofa was made using this artificial leather, it had a completely different natural feeling and a high-class feeling compared to a furniture sofa made using conventional artificial leather.

(Paint-5) Resamine NPU5NL 100 parts [Dainichi Seika Kogyo Co., Ltd.] Howlac Brown U1355 20 parts [Dainippon Ink and Chemicals Co., Ltd.] Isopropyl alcohol 20 parts Toluene 20 parts Dimethylformamide 20 parts

Comparative Example 1 The porous polyurethane layer of Substrate-2, whose surface was green in Example 2, had a melting point of 50 ° C. or higher as in Example 1.
A solution of urethane modified wax at 80 ° C. dissolved in toluene [manufactured by Dainippon Ink and Chemicals Co., Ltd .; Howlac Clear U-1400] is applied by a gravure coating machine (using a 200 mesh roll) and dried at room temperature twice. Next, the paint-4 prepared in Example 3 was applied in the same manner as in Example 1 using a gravure coater (using a 110-mesh roll) and dried three times, and then patterned with a hot embossing roll in a pore-like pattern. Then, the coating material-2 was applied to the surface thereof with a gravure coating machine (using a 110-mesh roll) and dried three times to obtain artificial leather-5. The amount of wax applied was 4.4 g / m ² , and the amount of the finished polyurethane coating applied was 8.0 g / m ² in total.

The obtained artificial leather-5 had a green surface, the adhesive force between the porous polyurethane layer and the finished polyurethane coating was 0.5 kg / cm or less, and the surface of the artificial leather-5 was stretched when bent or kneaded. The finished polyurethane coating was easily peeled off from the porous polyurethane layer, although the brightness of the compressed part and the compressed part slightly changed to cause natural unevenness. Further, when it is bent with a hair drier or the like and bent or kneaded, the finished polyurethane film is completely peeled off, and it does not have practical strength.

Example 5 2 kg of a mixed solution of 50% of methyl ethyl ketone and 50% of dimethylformamide was gravure coated (using a 200 mesh roll) on the surface of the substrate-1 (before the open pore developing treatment) prepared in Example 1. It was applied at a pressure of / cm ² and dried. Observation of the surface of the obtained substrate with a scanning electron microscope revealed that 1,800 open pores of about 2 μm were formed per cm ² . The surface area of the porous polyurethane layer excluding the open pores was 99.994% of the total area.

Wax coating and final polyurethane coating were formed on the surface of the substrate subjected to the open pore developing treatment in the same manner as in Example 1 to obtain artificial leather-6. In this case, the wax coating amount was 4.0 g / m ² , and the total coating amount of the finished polyurethane coating was 9 g / m ^2.
Met. The obtained artificial leather-6 had a brown surface, and when it was bent or rubbed, the extension and compression of the surface slightly changed in brightness to cause natural unevenness. Although it had a design appearance similar to that seen on leather, the wax did not completely enter the open pores, and the surface of the substrate and the finished polyurethane coating partly peeled off. Became.

Comparative Example 2 A dense layer of the surface of the porous polyurethane layer of Substrate-1 having a brown surface (before the open pore developing treatment) prepared in Example 1 was prepared.
Grinding was repeated twice with 180 mesh sandpaper to expose the open pores inside and to form 2,300 open pores of about 85 to 90 μm per cm ² (surface area of the porous polyurethane layer excluding the open pores). Is 45 for the total area
%Met). Then, on the surface area of the substrate subjected to the open pore expressing treatment, wax was applied and a finish polyurethane coating was applied by the same operation as in Example 1 to obtain artificial leather-7. In this case, the amount of wax applied is 4.9 g /
m ² and the total coating amount of the finished polyurethane film is 9
It was g / m ² . The obtained artificial leather-7 had a brown surface, and when it was bent or rubbed, the extension and compression of the surface slightly changed in brightness to cause natural unevenness. The surface of the porous polyurethane layer was released from the surface, and the object of the present invention could not be achieved.

Comparative Example 3 On the surface of the substrate-1 (before the open pore developing treatment) prepared in Example 1, 4 kg of a mixed solution of 90% methyl ethyl ketone and 10% dimethylformamide was applied by a gravure coater (using a 200 mesh roll). It was applied at a pressure of / cm ² and dried. Observation of the surface of the obtained substrate with a scanning electron microscope revealed that 400 open holes of about 12 μm were formed per cm ² . The surface area of the porous polyurethane layer excluding the open pores was 99.95% based on the total area.

Wax coating and final polyurethane coating were formed on the surface area of the substrate subjected to the open pore developing treatment in the same manner as in Example 1 to obtain artificial leather-8. In this case, the wax coating amount was 4.1 g / m ² , and the total coating amount of the finished polyurethane coating was 9 g / m ^2.
Met. The surface of the obtained artificial leather-8 was brown, and when it was bent or kneaded, the stretched portion and the compressed portion of the surface slightly changed in lightness to cause natural unevenness.
The finished polyurethane coating was in a state of peeling from the surface of the porous polyurethane layer on the substrate surface, and the object of the present invention could not be achieved.

Comparative Example 4 A solution prepared by dissolving a urethane-modified wax having a melting point of 20 to 35 ° C. in toluene was applied to the surface of the substrate-1 having been subjected to the open pore development treatment prepared in Example 1 by using a gravure coating machine (200 mesh). Application and drying were repeated twice using a roll. The amount of wax applied was 5.5 g / m ² . Next, Example 1
By the same operation as above, a finished polyurethane film is formed, a pore-like pattern is applied with a heating embossing roll, and artificial leather-
Got 9. The total coating amount of finish polyurethane film is 9
It was g / m ² . The surface of the obtained artificial leather-9 was brown, and the surface did not show any change even when bent or kneaded at room temperature of 25 ° C. When bent or rubbed at room temperature of 5 ° C., the stretched portion and the compressed portion of the surface are slightly changed in brightness to cause natural unevenness, and it can be said that the object of the present invention is achieved. There wasn't.

Comparative Example 5 A solution prepared by dissolving a urethane-modified wax having a melting point of 115 to 125 ° C. in toluene was applied to a gravure coating machine (200
The coating and drying were repeated twice using a mesh roll).
The amount of wax applied was 4.1 g / m ² . Next, in the same manner as in Example 1, formation of a finished polyurethane film,
Artificial leather-10 was obtained by applying a pore-like pattern with a heating embossing roll. The coating amount of the finishing polyurethane film is
The total amount was 9 g / m ² . The obtained artificial leather-10 is
The surface is brown, and when bent or kneaded, the extension and compression of the surface slightly changed brightness and natural unevenness occurred, but the state was the same as with the simple heating with a hair dryer. It was not possible to say that the object of the present invention was achieved, because it took a considerable time for heating to return to the original state without returning to the state.

[0054]

EFFECTS OF THE INVENTION According to the present invention, when used for shoes, clothes, bags and the like, when it is bent, the lightness of the color of the stretched portion and the compressed portion changes, which causes a natural unevenness. It is possible to obtain an artificial leather with a silver tone, which is excellent in oiliness and has a sufficient surface strength and an excellent oil-up design effect.

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Claims (3)

[Claims] 1. A thickness of 50 μm to 40 on one surface of a substrate (a) made of fibrous material or fibrous material and elastic polymer.
In a silver-tone artificial leather having a 0 μm porous polyurethane layer (b) and a finishing polyurethane coating (c) formed on the surface thereof, the finishing polyurethane coating (c) side of the porous polyurethane layer (b) There are 500 or more open pores having a diameter of 0.5 μm to 80 μm per cm ^{2 at} the interface, and the melting point is 40 ° C.
A wax at 100 ° C. or a mixture containing the wax as a main component is present so as to be embedded, and the adhesion area at the interface between the porous polyurethane layer (b) and the finished polyurethane coating (c) is 70% or more of the total area. An artificial leather with a silver finish that has an excellent design effect. 2. The thickness of 50 μm to 40 on one surface of a substrate (a) made of fibrous material or fibrous material and elastic polymer.
In a method for producing artificial leather by forming a porous polyurethane layer (b) by a wet method of 0 μm and forming a finishing polyurethane film (c) on the surface of the porous polyurethane layer (b), the density of the surface of the porous polyurethane layer (b) After mechanically grinding the high skin layer to open an open hole having a diameter of 0.5 μm to 80 μm, an organic solvent solution of a wax having a melting point of 50 ° C. to 100 ° C. or a mixture containing the wax as a main component is used. 2. The method for producing a silver-tone artificial body having an excellent design effect according to claim 1, wherein the coating is performed so as to be embedded in the open holes, the coating is dried, and then the finished polyurethane coating (c) is formed. 3. The thickness of 50 μm to 40 on one surface of the substrate (a) made of fibrous material or fibrous material and elastic polymer.
A method for producing artificial leather by forming a porous polyurethane layer (b) of 0 μm by a wet method and forming a finishing polyurethane film (c) on the surface of the porous polyurethane layer (b), wherein polyurethane is formed on the surface of the porous polyurethane layer (b). Of 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 is applied with a gravure mesh roll to form open holes with a diameter of 0.5 μm to 80 μm on the surface. After being generated, an organic solvent solution of a wax having a melting point of 50 ° C. to 100 ° C. or a mixture containing the wax as a main component is applied so as to fill the open holes and dried, and then a finished polyurethane film (c) is formed. The method for producing a silver-tone artificial leather having an excellent design effect according to claim 1.