JPH05195444A - Leather-like sheet material having excellent design effect and its production - Google Patents

Abstract

PURPOSE:To provide a leather-like sheet material moldable over a wide mold temperature range in the forming with a hot mold and to provide a process for producing the sheet material. CONSTITUTION:The objective sheet material is a laminate of a sheet substrate produced by applying a polymeric elastomer to a fibrous substrate, a porous resin layer composed of a polyurethane and a dry-formed polyurethane skin layer having a surface grain pattern. The porous resin layer is produced by the wet-coagulation of a mixture of two or more kinds of polyurethanes having softening point difference of >=30 deg.C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-like material having excellent design effects such as letters and designs, and more specifically, when a leather-like diaphragm is formed and a design is formed by pressing a heating mold. The present invention relates to a leather-like sheet having a wide temperature range in which a heating mold can be used and having an excellent design effect.

[0002]

2. Description of the Related Art Conventionally, as a leather-like sheet material for pressing a heated mold to form designs such as letters and designs, a sheet base material obtained by applying a polymer elastic body to a fibrous base material. It is known that a porous resin layer made of polyurethane is formed on the above, and a resin film layer is formed on the porous resin layer if necessary. Further, in order to impart a leather-like appearance, a method is known in which after forming a diaphragm by embossing on the surface of the above-mentioned porous resin layer or the surface of the resin film layer, the surface is colored with a gravure coater or the like.

The leather-like sheet having excellent design effects as described above is one in which an embossed design is formed on the surface of the sheet by pressing with a mold heated to about 160 to 210 ° C., for example. The temperature of the mold used at this time needs to be appropriately set according to the softening temperature of the porous resin layer. That is, when the softening temperature of the porous resin layer is high, the uneven shape is not sufficiently imparted unless the temperature of the mold is raised accordingly. On the contrary, when the softening temperature of the porous resin layer is low, the mold should not be heated to a correspondingly high temperature, and if the temperature is higher than necessary, the sheet-like material may adhere to or adhere to the mold surface.

In general, in shaping a design on a sheet having excellent design effect, a method of pressing a high temperature mold for a short time is advantageous in terms of processing efficiency. Therefore, the softening temperature of the porous resin layer is high. Is mainly made of a resin having a temperature of 190 ° C. or higher.

However, when a sheet-like material having a porous resin layer having a high softening temperature is subjected to shaping, it is necessary to keep the temperature of the mold at a high temperature and within a certain range, which requires a short time. When a large number of shaping processes are performed, it may be difficult to precisely control the temperature of the mold such that the temperature of the mold temporarily drops. For this reason, with the temperature change of the mold, it is not possible to impart a good uneven shape to the sheet-like material, and it may not be possible to obtain stable quality. Further, the mold temperature conditions and the like often differ depending on the contractor who presses the mold to shape the design. In this case, if a large variety of products are dealt with, the production efficiency will decrease.

Further, in the conventional method of forming a diaphragm on the surface by embossing, it is not possible to express even a delicate diaphragm of natural leather, and only a slightly lacking appearance of natural leather can be obtained. I can't.

[0007]

The present inventors have completed the present invention as a result of intensive studies in view of the above-mentioned problems, and an object of the present invention is to obtain a leather-like appearance having a natural leather-like appearance. Leather that is a sheet and that is excellent in design effect, in which a good uneven shape is stably imparted even when the temperature of the mold fluctuates to some extent when a design is shaped by pressing a heating mold on the surface thereof. A sheet-like product and a method for producing the same.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a sheet substrate made of a fibrous substrate provided with a polymeric elastic material, a porous resin layer made of polyurethane, and a diaphragm formed on the surface. A sheet-like product formed by laminating a polyurethane dry film layer, wherein the porous resin layer is obtained by wet coagulating a mixture of at least two kinds of polyurethanes having different softening temperatures of 30 ° C. or more. This is achieved by a leather-like sheet having an excellent design effect.

Another object of the present invention is to apply a polyurethane solution onto a sheet base material obtained by imparting a polymeric elastic material to a fibrous base material and wet-coagulate it to form a porous resin layer, Further, in the method for producing a sheet-like article by sticking a polyurethane dry film layer thereon, the polyurethane solution comprises:
It is achieved by a method for producing a leather-like sheet material having an excellent design effect, which comprises a mixture of at least two types of polyurethanes having different softening temperatures of 30 ° C. or more.

The sheet base material referred to in the present invention is a fibrous base material made of non-woven fabric, woven fabric, knitted fabric, etc. Is filled with a polymeric elastic material, or a coating layer of the same polymeric elastic material is formed on the surface thereof,
The production may be performed by a known appropriate method.

Examples of the elastic polymer include polymers such as polyurethane resin, vinyl chloride resin, acrylic ester / styrene copolymer, styrene / butadiene copolymer, urethane / vinyl chloride copolymer and mixtures thereof. And preferably a polyurethane resin and a mixture of a polyurethane resin and a urethane / vinyl chloride copolymer.

In the present invention, a resin layer having a porous structure is formed on the surface of the sheet base material. The porous resin layer is made of polyurethane, and usually has a pigment or dye dispersed therein for coloring in a desired color.
The polyurethane forming the porous resin layer is obtained by wet coagulating a solution in which at least two kinds of polyurethanes having different softening temperatures are mixed.

The polyurethane to be mixed is a mixture of polyurethanes having different softening temperatures of 30 ° C. or higher, preferably 30 to 100 ° C., more preferably 40 to 60 ° C. If the difference in softening temperature is less than 30 ° C., the optimum temperature range of the mold for shaping is narrowed. Examples of the combination of the polyurethane include a polyurethane having a softening temperature of 180 to 220 ° C. and a softening temperature of 12
The thing which combined the polyurethane of 0-150 degreeC can be mentioned.

The mixing ratio of the polyurethane having a low softening temperature and the polyurethane having a high softening temperature to be mixed is preferably 1: 9 to 6: 4, more preferably 2: 8 to 4: 6.
Is.

The porous resin layer is formed by the wet coagulation method. When the porous resin layer is formed by the dry foaming method, it is not preferable because the change in color is poor when the design is shaped by heating molding.

In the present invention, the porous resin layer is formed on the surface of the sheet base material. The porous resin layer is prepared by dissolving polyurethane mixed in the above combination in an appropriate solvent and adding an appropriate amount of a pigment or dye of a desired color as necessary to prepare an organic solvent solution, which is then subjected to the above sheet. It can be formed by coating on a substrate, wet coagulation, washing with water and drying. The thickness of the porous resin layer is preferably 0.1 to 0.6 mm, more preferably 0.2 to 0.5 m.
It is about m.

Further, in order to increase the color change when shaped by the heating mold, it is preferable to use a pigment or dye of a color other than white. Furthermore, a solution obtained by adding a small amount of carbon black to a polyurethane solution together with a pigment or a dye is subjected to wet coagulation, whereby a porous resin layer having a large color change can be obtained.

In the sheet-shaped article of the present invention, a dry coating layer made of polyurethane is formed on the porous resin layer. This polyurethane dry coating layer preferably has a thickness of 1
It is a film having a size of about 00 to 400 μm, and a natural leather tone diaphragm is formed on the surface thereof.

The above-mentioned polyurethane dry film layer is formed, for example, by coating a release paper with a polyurethane solution, drying and curing to form a film, and then adhering it to the porous resin layer with an adhesive, or by using a polyurethane solution on the release paper. Can be formed by a method of coating and drying and curing in a state of being superposed and pressure-bonded with the porous resin layer before being dried and cured. The release paper used here is preferably one with a diaphragm because it can form a delicate natural leather-like diaphragm. The method of applying a diaphragm to the surface of the coating layer by embossing is not preferable because a delicate diaphragm cannot be obtained.

The concentration of the polyurethane solution applied to the above-mentioned release paper is not particularly limited, but preferably 1
It is 0 to 30% by weight, more preferably 15 to 25% by weight. The coating amount may be appropriately selected depending on the concentration of the solution and the thickness of the skin layer to be obtained, but for example, 50 to 200 g /
m ² can be mentioned.

[0021]

EFFECTS OF THE INVENTION The leather-like sheet material of the present invention has a much wider temperature range of the mold for good shaping, as compared with the conventional product, so that even if the mold temperature slightly changes, Shaped processing with stable quality is possible. Therefore, it is extremely suitable when a large amount of shaping is performed or when the temperature control of the mold is not precise.

Further, since the leather-like sheet material of the present invention has a delicate diaphragm formed on the surface, it has an appearance very similar to that of natural leather.

According to the method of the present invention, a novel leather-like sheet material having a wide mold temperature range for good shaping can be produced.

[0024]

The present invention will be described in detail below with reference to its examples. In the examples and comparative examples, "part" means "part by weight".

Example 1 Polyurethane elastomer 100 was applied to the surface of release paper with a diaphragm.
Part, 5 parts of organic pigment, and 40 parts of dimethylformamide were applied by a knife coater at 100 g / m ^{2 and} dried at 130 ° C. for about 5 minutes to form a polyurethane thin film layer.

A non-woven fabric (weight of 240 g / m ² , thickness of 1.6 mm) made of ester short fibers (fineness: 1.5 denier, length: 50 mm) was added to polybutylene adipate glycol, diphenylmethane-4,4'-diisocyanate and ethylene. A solution of 100 parts of polyurethane elastomer synthesized from glycol, 1.5 parts of iron oxide brown and 100 parts of dimethylformamide was impregnated, wet-coagulated, thoroughly washed with water and dried to a thickness of 1.5 mm, A base material having an apparent density of 0.34 g / cm ³ was obtained.

Next, on one surface of the obtained substrate, 20 parts of a polyurethane elastomer having a softening temperature of 130 ° C. and 80 parts of a polyurethane elastomer having a softening temperature of 210 ° C., 2 parts of iron oxide brown as a colorant and 3 parts of dimethylformamide were used.
800 g / m ^{2 of a} solution consisting of 0 part and 3 parts of surfactant
After coating, the polyurethane was solidified by immersing it in water. This was washed with warm water to completely remove dimethylformamide, and then dried to form a brown porous resin layer.

Next, a urethane adhesive is applied to the polyurethane thin film layer prepared previously, and then the resultant is superposed on the porous resin layer, and the pressure is 4 kg / cm ² , and the temperature is 100 ° C.
Then, it was heated under pressure, and a polyurethane thin film layer was attached to the porous resin layer. This was aged at 40 ° C. for 24 hours to cure the adhesive by reaction. Then, the release paper was peeled off to obtain a leather-like sheet.

<Shaping processing> On the obtained leather-like sheet material, a mold having an uneven pattern formed on the surface was heated to a temperature shown in Table 1 and heated under pressure for 1 second to perform shaping processing.
The results are as shown in Table 1, and a good three-dimensional design was formed at any heating temperature, and the design was large with a large color change and clear.

Example 2 Polyurethane elastomer 20 having a softening temperature of 150 ° C. was used in place of the two polyurethane elastomers compounded in the solution used for forming the porous resin layer in Example 1.
Parts and polyurethane elastomer 8 with a softening temperature of 200 ° C.
A leather-like sheet material was obtained in the same manner as in Example 1 except that 0 part was blended.

The obtained leather-like sheet was shaped in the same manner as in Example 1. The results are as shown in Table 1.

Example 3 Polyurethane elastomer 20 having a softening temperature of 160 ° C. was used in place of the two polyurethane elastomers compounded in the solution used for forming the porous resin layer in Example 1.
Parts and polyurethane elastomer 8 with a softening temperature of 190 ° C
A leather-like sheet material was obtained in the same manner as in Example 1 except that 0 part was blended.

The obtained leather-like sheet was shaped in the same manner as in Example 1. The results are as shown in Table 1.

Example 4 The mixing ratio of the two polyurethane elastomers mixed in the solution used to form the porous resin layer in Example 1 was 40 parts of polyurethane elastomer having a softening temperature of 130 ° C. and 210 ° C. of a softening temperature. A leather-like sheet material was obtained in the same manner as in Example 1 except that 60 parts of the above polyurethane elastomer was used.

The obtained leather-like sheet was shaped in the same manner as in Example 1. The results are as shown in Table 1.

Comparative Example 1 Polyurethane elastomer 20 having a softening temperature of 150 ° C. was used in place of the two types of polyurethane elastomer compounded in the solution used for forming the porous resin layer in Example 1.
Parts and polyurethane elastomer 8 with a softening temperature of 170 ° C.
A leather-like sheet was obtained in the same manner as in Example 1 except that 0 part was blended.

The obtained leather-like sheet was shaped in the same manner as in Example 1. The results are as shown in Table 1.

Comparative Example 2 Instead of the two polyurethane elastomers blended in the solution used for forming the porous resin layer in Example 1, one polyurethane elastomer having a softening temperature of 160 ° C. was used.
A leather-like sheet material was obtained in the same manner as in Example 1 except that the compounding amount was 00 parts.

The obtained leather-like sheet was shaped in the same manner as in Example 1. The results are as shown in Table 1.

Comparative Example 3 Instead of the two polyurethane elastomers compounded in the solution used for forming the porous resin layer in Example 1, one polyurethane elastomer having a softening temperature of 190 ° C. was used.
A leather-like sheet material was obtained in the same manner as in Example 1 except that the compounding amount was 00 parts.

The obtained leather-like sheet was shaped in the same manner as in Example 1. The results are as shown in Table 1.

[0042]

[Table 1]

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Claims (2)

[Claims] 1. A laminate comprising a sheet substrate made of a fibrous substrate provided with a polymer elastic material, a porous resin layer made of polyurethane, and a polyurethane dry film layer having a diaphragm formed on the surface thereof. A sheet-like material, wherein the porous resin layer is a mixture of at least two kinds of polyurethanes having different softening temperatures of 30 ° C. or more, which are wet-solidified, and a leather-like sheet material having an excellent design effect. . 2. A polyurethane solution is applied onto a sheet base material obtained by imparting a polymer elastic body to a fibrous base material, and wet-coagulated to form a porous resin layer, and a polyurethane dry type is further formed thereon. A method for producing a sheet-like product by attaching a coating layer, wherein the polyurethane solution comprises a mixture of at least two types of polyurethanes having different softening temperatures of 30 ° C. or more, and a leather having an excellent design effect. A method for manufacturing a sheet-like material.