JPH083879A - Method for manufacturing leather-like sheet - Google Patents

Abstract

(57) [Summary] [Structure] A thermoplastic polymer elastic body extruded in the form of a film is pressed between a fibrous substrate and a shaping roll while having fluidity, and is adhered to the fibrous substrate and at the same time the surface is A leather-like sheet is manufactured by shaping. [Effect] (1) The thermoplastic polymer elastic body on the outermost surface has a small heat history, and therefore has excellent surface abrasion resistance. (2) Since there is no adhesive layer between the fibrous base material layer and the coat layer, it has a leather-like texture with a sense of unity. (3) Good adhesion between the fibrous base material layer and the coat layer, and excellent peeling strength. (4) Since the coat thickness of the outermost thermoplastic polymer elastic material can be freely changed, and it is imprinted in a fluid state, a desired unevenness and surface feeling can be obtained, from deep grain patterns to enamel tones. Obtainable. (5) Since the film-shaped thermoplastic polymer elastic material is laminated on the fibrous substrate, the unevenness of the fibrous substrate surface hardly affects the sheet surface, and a sheet having a constant surface feeling can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite sheet made of a polymer elastic material. Especially excellent surface durability,
The present invention also relates to a method for producing a leather-like composite sheet having a soft texture.

[0002]

2. Description of the Related Art Conventionally, in a method for producing a leather-like sheet having an excellent unevenness, there is a method of embossing the surface of a composite sheet having a leather-like texture composed of fibers and a polymer elastic body with a heated roll. Japanese Examined Patent Publication No. 47-24662,
Alternatively, a method in which a composite sheet is heated to have plasticity and then embossed is described in Japanese Patent Publication No. 38-14495, or after a film-like polymer elastic body having plasticity is attached to a substrate, the film surface having plasticity A method of stamping from a mold is proposed in Japanese Patent Publication No. 55-51074.
There is also known a method in which a film-like sheet which has already been embossed and has an uneven pattern is attached to a composite sheet having a leather-like texture. Further, there is a method of pressing the film with the base material in a state where the shape-imparting film, the resin layer and the base material are laminated and removing the shape-imparting film.
No. 71 is proposed.

[0003]

However, in the conventional method, a leather-like sheet having an arbitrary unevenness feeling, a soft texture, and practical durability is obtained by heating the surface with heat or a chemical agent. The surface strength decreases because it is used for embossing, the surface hardens and the texture becomes hard,
In addition, in the method of pasting embossed sheets with an adhesive, an adhesive layer is placed between the film having surface abrasion resistance and the substrate, so that the texture does not have a sense of unity, However, there is a problem in the peeling state between the sheet and the base material, a leather-like sheet having a soft texture and practical durability has not been obtained. The present invention, which has not been obtained by the prior art, gives an arbitrary unevenness to the surface, has a feeling of unity and has a soft texture, and has high adhesion between the surface layer polymer elastic film and the substrate. An object of the present invention is to provide a method for producing a leather-like sheet which has both strength and strength.

[0004]

According to the present invention, a thermoplastic polymer elastic body extruded in the form of a film is pressed between a fibrous substrate and a shaping roll while having fluidity and is bonded to the fibrous substrate. In addition, the method for producing a leather-like sheet is characterized in that

As long as the fibrous substrate used in the present invention is a sheet having an appropriate thickness and a sense of fulfillment, and having a soft texture, various fibrous materials conventionally used for the production of leather-like sheets are used. Substrates can be used. For example,
Ultrafine fibers or bundled fibers thereof, special porous fibers, entangled nonwoven fabric composed of ordinary fibers, etc., and a polymeric elastic body such as polyurethane is contained in the internal space of a raised woven or knitted fabric in a porous or non-porous state. Examples of the fibrous sheet include a fibrous sheet, and a fibrous sheet having a porous coating layer of an elastic polymer on the surface of these fibrous sheets. Among them, it has the texture closest to leather, and the state of adhesion when the thermoplastic polymer elastic material is coated in a layer on the surface, the strength, from the viewpoint of strength, contains the polymer elastic material in the non-woven fabric composed of ultrafine fiber bundles. It is preferable to use a fibrous sheet. The elastic polymer is
Resins that have been conventionally used in the production of leather-like sheets, such as polyurethane resin, vinyl chloride resin, polyvinyl butyral resin, polyacrylic acid resin, polyamino acid resin, silicone resin, and mixtures and copolymers of these resins. . From the viewpoint of adhesiveness, it is preferable that the polymer elastic body that constitutes at least the surface portion of the fibrous substrate is the same resin as the thermoplastic polymer elastic body laminated on the surface. Further, in order to increase the adhesive strength, it is also preferable to apply a surface treatment agent such as a resin having a high affinity for the thermoplastic polymer elastic body to the surface of the fibrous base material. In this case, the applied thickness is about 5 μm as a guide. When the coating thickness is large, the surface treatment agent forms a layer between the fibrous base material and the thermoplastic polymer elastic body, and it becomes difficult to obtain a soft texture and a texture with a sense of unity.

The thickness of the fibrous base layer can be arbitrarily selected depending on the use of the obtained leather-like sheet, etc., but is preferably in the range of 0.5 to 3.0 mm from the balance of the texture with the coat layer. Further, it is preferably 1.0 to 1.5 mm. The apparent density of the fibrous base layer is preferably in the range of 0.25 to 0.5 g / cm ³ , and more preferably 0.3 to 0.
It is in the range of 35 g / cm ³ . When the apparent density becomes large, the texture is strongly influenced by the fibrous sheet and the polymer elastic body, and the texture becomes rubber-like and loses its stiffness.
On the other hand, when the apparent density becomes smaller, the resilience and the firm texture are obtained, and the texture is far from the leather-like texture.
The weight ratio of the fibrous sheet to the polymeric elastic material is also important for obtaining a leather-like texture, and the proportion of the polymeric elastic material in the fibrous base layer is preferably 20 to 60% by weight. When the ratio of the polymer elastic body is small, the elastic feeling is not felt, and when the ratio of the polymer elastic body is high, the feeling of repulsion is too strong and the rubber-like texture is obtained.

The thermoplastic polymer elastic material used as the coat layer of the leather-like sheet in the present invention includes polyurethane resin, vinyl chloride resin, polyvinyl butyral resin, polyacrylic acid resin, polyamino acid resin, silicone resin and these resins. Examples thereof include a mixture and a copolymer. Above all,
Thermoplasticity, surface strength and adhesion to substrate, peel strength,
From the point of view of texture, it is preferable to use a polyurethane resin. The polyurethane resin used in the coating layer in the present invention is not particularly limited as long as it can be melt-formed into a film, but is not limited to polybutylene adipate, polymethylpentane adipate, polynonanediol adipate / polyoctanediol adipate. Polyurethane resins such as those used in the present invention are preferably used. Polymethylpentane adipate-based polyurethane is preferred from the viewpoints of abrasion resistance and texture of the obtained leather-like sheet. You may add additives, such as a pigment and a light stabilizer, to these resins.

The thermoplastic polymer elastic material is melt-extruded into a film by using an extruder such as a T-die. The thickness of the coat layer differs depending on the type and performance of the thermoplastic polymer elastic body, and is particularly limited as long as it has a leather-like texture and satisfies the surface strength, adhesive strength and flexibility. Although it is not limited, it is usually preferably in the range of 50 μm or more and 500 μm or less, and 100 μm
It is more preferable that the thickness is m or more and 200 μm or less. If the coat layer is too thin, the base layer is likely to be exposed due to surface abrasion, and the durability in practical use decreases, and if the coat layer is too thick, the flexibility deteriorates or the surface is coated. It becomes close to the flexibility of the polymeric elastic body and does not have a leather-like texture.

The coat layer does not have to be a single layer,
Plural layers of resins having different compositions may be extruded together, or may be extruded separately and then laminated. For example, it is also possible to use a thermoplastic polymer elastic body having high physical properties as the outermost surface layer, and apply a coating having a thermoplastic polymer elastic body layer having a low film physical property in which an intermediate layer is added with a pigment or the like. By this method, the migration of the pigment can be suppressed by the clear layer on the outermost surface, so that a colored coat having good friction fastness and migration property is possible. In addition, in the case of stacking in multiple layers, it is possible to color each layer and simultaneously develop multiple colors, so that a coat having an elegant surface feeling and texture is possible.

The thermoplastic polymer elastic body melt-extruded in the form of a film is pressed between the fibrous substrate and the shaping roll while having fluidity to be adhered to the fibrous substrate and shaped on the surface. The shaping roll referred to in the present invention may be a combination of an embossing roll having a mirror surface or an uneven embossing pattern on the surface or a releasable embossing sheet and a normal roll. In addition, the imprinting in the present invention includes, in addition to imparting an uneven pattern to the surface, mirror finishing such as an enamel-like sheet using a mirror roll or a mirror sheet. When using an embossing roll, it is preferable because it can easily give a desired deep unevenness feeling,
When an embossed sheet is used, it is preferable because an arbitrary embossed pattern can be selected only by replacing the embossed sheet.

As a method for pressing the thermoplastic polymer elastic body extruded in the form of a film between the fibrous substrate and the shaping roll, the thermoplastic polymer elastic body is extruded onto the fibrous substrate in advance and then the A method of pressing through a mold roll and a back roll facing the shaping roll, and a fiber between the shaping roll and the back roll facing the shaping roll after the thermoplastic polymer elastic body is extruded onto the shaping roll. There is a method of supplying and pressing a polymer base material, or a method of directly extruding a thermoplastic polymer elastic body between a shaping roll and a fibrous base material and pressing it with an opposing back roll. As long as the polymeric elastic body has fluidity, there is no particular difference in any method. Particularly preferred is a method in which a thermoplastic elastic body is extruded onto a fibrous substrate and then shaped by a shaping roll in terms of less air biting and good pattern transferability on the roll surface. In the case of an embossing roll, a metal roll is usually used as the roll material. The back roll may be either a metal roll or an elastic roll, but it is preferable to use the elastic roll from the viewpoint of stability of pressing force.

It is important that the pressing with the shaping roll is performed while the thermoplastic polymer elastic material has fluidity. That is, even if pressure treatment is performed after the fluidity is lost, the shaping and the adhesion to the fibrous substrate cannot be performed, and the thermoplastic polymer elastic film is heated again for the shaping and the adhesion to the fibrous substrate. It is not preferable to impart fluidity because surface physical properties such as abrasion resistance of the thermoplastic polymer elastic body are deteriorated each time thermal history is repeated. By this pressing treatment, the surface is sufficiently shaped by a shaping roll, and at the same time, a part of the thermoplastic polymer elastic body flows into the inside of the fibrous substrate and adheres to the fibrous substrate by a physical anchor effect. Be integrated.
For this reason, the fibrous base material layer and the thermoplastic polymer elastic body coating layer have an effect of practically sufficient peel strength as a leather-like sheet without using an adhesive. The pressure to press is
It depends on the fluidity of the thermoplastic polymer elastic body, the apparent density and flexibility of the fibrous base material, etc., but cannot be said to be unequivocal, but generally the gauge pressure is in the range of 5 to 15 kg / cm ² Select as appropriate within the range that satisfies your strength. If the pressing force is low, sufficient shaping and adhesive force of the coat layer cannot be obtained, but if the pressing force is too high, the thermoplastic polymer elastic body excessively penetrates into the inside of the fibrous substrate, and the texture tends to be hard.

The leather-like sheet shaped on the surface is peeled off from the shaping roll after the fluidity of the thermoplastic polymer elastic material is substantially lost. If it is separated from the shaping roll while it has fluidity, the corners of the protrusions collapse, causing a so-called grain flow, and a sharp uneven pattern cannot be obtained. Therefore, when the embossing roll is used as the shaping roll, it is cooled by circulating a cooling liquid inside, if necessary, without heating the roll, and the pressed sheet is wound around the embossing roll for about a half turn. It is preferable to cool it sufficiently. Further, in the case of using an embossed sheet for shaping, it is also preferable to cool with a cooling roll or the like, or to wind the laminated embossed sheet once and age it, and then peel off the embossed sheet.

[0014]

EXAMPLES Next, the embodiments of the present invention will be specifically described with reference to Examples. The present invention is not limited to these examples. The abrasion resistance measured in the examples was measured by a Taber rotary abrader (with a dust suction unit) according to JIS
The amount of wear reduction was measured according to L1096 6.17.3 and compared. Further, the peel strength was measured by a method in which the measured substance was adhered to the support on the coat layer side, allowed to stand in a standard state for 24 hours, and then peeled at 180 degrees.

Example 1 A 1.5 mm-thick fibrous substrate containing polyurethane in an entangled nonwoven fabric of ultrafine fiber bundles of nylon was prepared. Polymethylpentane adipate-type polyurethane as a thermoplastic polymer elastic body coated on the surface between a fibrous substrate passed through a back roll and a metal embossing roll having a textured pattern of pores on the surface and the embossing roll. Was extruded from a T-die and cold-pressed at a gauge pressure of 10 kg / cm ² to obtain a leather-like sheet having pores and wrinkles. The polyurethane coating on the surface had a thickness of 100 μm. The texture and unevenness had a deep texture similar to the textured texture of natural leather and had a soft texture. Also,
The peel strength was as high as 15 kg / 2.54 cm, and the surface abrasion resistance was 4 mg as the abrasion loss.

Comparative Example 1 On a release paper having a textured pattern of pores, a solution of a polycarbonate-based polyurethane as a skin layer polyurethane was applied at a solid content of 50 g / m ² , dried and solidified, and a polyether-based polyurethane as an adhesive polyurethane. The solution was applied in a solid content of 50 g / m ² and was adhered to the surface of the same fibrous substrate as in Example 1 while having an adhesive property, aged, and the release paper was removed to obtain a leather-like sheet. The obtained leather-like sheet had a leather-like texture coming from the base material, but the peeling strength was 7 kg / 2.54 cm, and the surface abrasion resistance was 20 mg in terms of abrasion loss. Both were worse than Example 1 of the present invention.

Comparative Example 2 A 100 μm-thick polymethylpentane adipate-based polyurethane film having a textured pattern of pores and pores on its surface was coated with 30 g / m ² of a two-component polyurethane adhesive, and the same fibrous substrate as in Example 1 was applied. After laminating, pressing and drying, a leather-like sheet was obtained. The textured pattern on the surface changed so that the unevenness that had been shaped due to pressing became shallow, and the texture had a strong repulsive force when bent and was a hard leather.
As for physical properties, the Taber abrasion was 4 mg, but the peel strength was as low as 5 kg / 2.54 cm after peeling from the adhesive surface between the film and the fibrous substrate.

COMPARATIVE EXAMPLE 3 On the surface of the same fibrous substrate as in Example 1, an emulsion of polymethylpentane adipate type polyurethane was added in a solid content of 1: 1.
After applying 00 g / m ² and drying, a leather-like sheet was obtained by pressing with an embossing roll having a hair grain pattern heated to 180 ° C. The obtained leather-like sheet had deep texture, full texture, and was close in texture and texture to natural leather, but the Taber abrasion was 120 mg and the abrasion resistance was poor, and the deterioration of polyurethane due to embossing heating. It seems to be the influence of.

Example 2 On the same fibrous substrate as in Example 1, 20 PH of yellow pigment was added.
Polymethylpentane adipate polyurethane with R added and 50 PHR of blue pigment with polymethylpentane adipate polyurethane were co-extruded to a thickness of 50 μm so that the yellow layer is on the surface side, and the polyurethane surface has fluidity. A leather-like sheet was obtained by cold embossing with an embossing roll having a textured pore inside. The obtained leather-like sheet has a color impression such that the blue color of the lower layer is bleeding out on a yellow background, and when pressed by embossing, the blue color of the lower layer is deeply transparent and has two-color impression. It was a leather-like sheet with a face.

Comparative Example 4 Polycarbonate-based polyurethane solution containing 20 PHR of yellow pigment was coated at 30 g / m ² in solid content on a release paper having a textured pattern of pores, dried and solidified, and further 30 PHR of blue-based pigment was added. The added polyether-based polyurethane solution for the adhesive layer was applied at a solid content of 50 g / m ² and lightly dried to bond the same fibrous substrate as in Example 1 while having a tacky surface, aged, and release paper. Was removed to obtain a leather-like sheet. Regarding the color appearance of the obtained leather-like sheet, the pigments of the skin layer and the adhesive layer were mixed at the interface to give a cloudy color, and the transparent color tone as in Example 2 was not obtained.

[0021]

The leather-like sheet produced by the method of the present invention has the following features. (1) Since the thermoplastic polymer elastic body on the outermost surface has a small heat history, it has excellent surface abrasion resistance. (2) Since there is no adhesive layer between the fibrous base material layer and the coat layer, it has a leather-like texture with a sense of unity. (3) Good adhesion between the fibrous base material layer and the coat layer, and excellent peeling strength. (4) Since the coat thickness of the outermost thermoplastic polymer elastic material can be freely changed, and it is imprinted in a fluid state, a desired unevenness and surface feeling can be obtained, from deep grain patterns to enamel tones. Obtainable. (5) Since the film-shaped thermoplastic polymer elastic material is laminated on the fibrous substrate, the unevenness of the fibrous substrate surface hardly affects the sheet surface, and a sheet having a constant surface feeling can be obtained.

Claims (1)

[Claims] 1. A thermoplastic polymer elastic body extruded in the form of a film is pressed between a fibrous base material and a shaping roll while having fluidity so as to adhere to the fibrous base material and be shaped on the surface. And a method for producing a leather-like sheet.