JPS6235040Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a novel synthetic leather that uses a knitted or woven fabric for its surface layer and has a clear three-dimensional pattern and an elegant luster and transparency. More specifically, the surface layer, which corresponds to the grain layer of natural leather, is a fluff-free knitted fabric (knitted fabric or woven fabric) made of modacrylic fibers with a deep and clear three-dimensional pattern, and the base layer, which corresponds to the reticulated layer of leather, is heated. It is composed of a soft foam made of moldable synthetic resin, and the convex parts on the surface are the fabric surface, and the recesses formed by the surface layer biting into the base layer are smooth, which can be called skin surfaces, and the whole or part of the surface is This invention relates to synthetic leather consisting of a novel structure in which the outer layer is covered with a transparent or semi-transparent paint layer that can be called a skin.

Traditionally, it has been used as an alternative to natural leather for clothing, furniture,
Synthetic leather, which is widely used as a material for wall coverings, bags, shoes, etc., mainly consists of a base fabric layer (woven fabric, knitted fabric, non-woven fabric) that corresponds to the net layer of natural leather, and a silver layer of leather. It has a two-layer structure in which a resin layer corresponding to the surface layer is coated or adhered. The resin layer is made of porous or non-porous polyvinyl chloride (also called vinyl leather or sponge leather), polyurethane, polyamide,
Polyamino acids, etc. (referred to as synthetic leather in a narrow sense)
A synthetic resin having a texture and physical properties similar to those of natural leather is used, and if necessary, coating or other surface treatments are applied. The former is inexpensive, versatile, and used in extremely large quantities, but the image of its low price and low quality has now permeated consumers and it is starting to be disliked. The latter has been devised in a wide variety of ways by combining each component, that is, the base fabric layer and the resin layer, and various improvements, and is now replacing natural leather in many fields. However, these synthetic leathers are intended to reproduce natural leather, and their appearance and texture are not much different from natural leather.

On the other hand, a wide variety of fabrics are also used for the above-mentioned purposes. The difference between this fiber knitted fabric and synthetic leather or vinyl leather is that the former has a knitting structure, so the surface appearance, texture,
It has a wide variety of colors and a surface with excellent physical and chemical strength. However, it does have some drawbacks, such as the surface staining is inferior to the synthetic leather that forms the film surface.

By the way, if we look at trends in past trends, there was a time when leather and synthetic leather preferred the appearance and texture of the glossy film surface represented by enamel, and a time when the appearance and texture of the fabric surface was preferred. There have been alternating periods in which the preference for Particularly in recent years, trends have been changing rapidly and there has been a tendency for people to prefer newer items, so there is a strong desire to provide materials that match these trends. For example, suede-like synthetic leather, Jiaguard woven fabric, and simple, shiny, lightweight taffeta are used as materials that have an element intermediate between the surface of cloth and the surface of film. Also,
Materials in which the fabric surface is oil-coated or transparent or translucent polyurethane film is directly coated on thin fabric also allow the structure and color of the underlying fabric to appear on the surface through the film layer, and are in line with recent clothing sensibilities. It has been well received as a. However, these materials cannot fundamentally be said to deviate from the conventional techniques of cloth and synthetic leather, and have recently become increasingly disliked.

Therefore, the inventor of the present invention continued to research various prototypes from the viewpoint of developing new materials, and found that the composition, especially the surface layer, is completely different from conventional synthetic leather, which aims to be natural leather, and that the appearance and texture of the skin surface and cloth surface are completely different. Developed a new synthetic leather with both sides (patent application 1983-
31503). This synthetic leather is a textile fabric made of modacrylic fibers that has been treated with fluff to prevent fluffing, and the fabric side of the foam laminate has a soft foam made of thermoplastic synthetic resin as a base layer. It has an embossed pattern in which the convex portions are the fabric surface and the concave portions are the skin-like smooth surface, and can also be called modacrylic synthetic leather. By fluffing, a deep and clear three-dimensional pattern with a gentle luster is obtained, and it has the appearance, texture, and unique feel and physical properties of both conventional synthetic leather and textile fabric.

The present invention further improves the modacrylic synthetic leather described above to give the fabric surface an elegant luster and deep transparency, and also makes uneven patterns, textures, and stitches more prominent to emphasize changes in the fabric surface. In addition, the present invention provides a new material, synthetic leather, which prevents the disadvantages of fabrics, such as easy staining and water permeability. Hereinafter, the present invention will be explained in detail based on the drawings.

FIG. 1 shows an example of synthetic leather 1 according to the present invention. As shown in Figure 2 (an enlarged cross-sectional view of the section taken along the line X-X in Figure 1), this is a polyacrylic fiber, especially the product name ``Kanekalon'' (manufactured by Kanegafuchi Chemical Industry Co., Ltd.).
The surface layer is a fabric 2 with a satin texture made of modacrylic fiber known as "Dynel" (manufactured by Union Carbide Co., Ltd.), and a foam 3 of a 1,2-polybutadiene resin alone or a polymer blend containing this as one component ( An embossed pattern is applied to the fabric side of the foam laminate (formbacks) 4, which has a base layer of ``1,2-PBD foam'' (hereinafter referred to as "1,2-PBD foam"), in which the protrusions A are on the fabric surface and the recesses B are on the smooth surface. Furthermore, the surface of the fabric 2 is thinly covered with a transparent paint layer 5.
In the figure, reference numeral 6 is an adhesive layer, and 7 is a knitted fabric serving as a reinforcing backing material. Further, the recess B is formed using dielectric heating using high frequency, and
The 2-PBD foam is softened and compressed according to the heating mold, and becomes closer to the unfoamed 1,2-PBD resin by the depth. On the other hand, modacrylic fibers are similarly softened or partially melted by the heating mold, and the 1,2-
It expands and deforms along the PBD foam, and a part of the bottom part takes on the shape of a thin film. However, other parts that are not pressurized do not undergo any changes,
The surface remains as a cloth, the 1,2-PBD foam also maintains its cushioning function in its original state, and the boundary between the convex portions A and the concave portions B is clearly visible.

By the way, the inventor of the present invention previously created a three-dimensional patterned cloth material consisting of a structure similar to that of the present invention (Utility Application 1983-
19660). However, modacrylic fibers are generally in the form of staples, and the fabric surface inevitably becomes fluffy. This fuzz remains as it is on the surface of the fabric, which is a convex part, making the deep embossed pattern unclear, and in the concave part, the fuzz becomes an obstacle, making it difficult to form a clear and glossy skin surface, making it difficult to apply paint. When processed, the texture and stitches were hidden by the fuzz, and irregular small protrusions were formed, making the surface less clear. In particular, when a thin coat of paint is applied to make the most of the texture of cloth, the fuzz will stick out on the surface, and when only the convex areas are coated, the fuzz in the concave areas will be noticeable. Moreover, in the three-dimensional patterned cloth material, no limitations were taken into consideration regarding the weaving structure, thread residue, etc., and it was difficult to obtain a clear uneven pattern.

Therefore, the inventor of the present invention continued his research, and by treating the fluff of the fabric and selecting an appropriate fabric, he created synthetic leather with a three-dimensional effect that takes advantage of the feel of the fabric and has an elegant luster and deep transparency. This is what led to this.

Therefore, the fabric used in the present invention is a knitted fabric using modacrylic fiber (vinyl chloride acrylonitrile copolymer fiber), and is fluffed and the physical properties of the grain layer (skin layer) of the leather are improved before and after embossing. must be similar to.
The fluff treatment may be done by using a calender roll to lay out the fluff.
It is most preferable to remove fuzz by burning the yarn or cloth.

In addition to the satin weave shown in FIG. 1, the fabric is preferably one that has a relatively dense and thin texture, such as a broad weave (plain weave), and has a flat texture with little change in the fabric surface. The reason why the texture is dense is that the base resin (soft foam) does not protrude from the gaps between the threads in the embossed part in a peeled state. Furthermore, the thin and flat surface provides smoothness and flexibility comparable to the skin layer of natural leather before and after embossing, and in particular allows the formation of a thin and soft film layer after embossing.
It also needs to be soft to the touch.
In order to satisfy the above conditions, it is necessary to select the thread thickness, basis weight, and weaving or knitting structure as described below. If the fabric is knitted, elongation (stretchability)
Synthetic leather with good quality can be obtained.

By the way, even if the physical properties of a single fiber or yarn are harder than those of a soft film, depending on the structure of the fabric and appropriate processing conditions, it is possible to achieve drapability similar to that of a low modulus soft material. The ability to provide certain properties is an important point in making this structure match the texture of leather. This modacrylic fiber has much better thermoformability than other synthetic fibers such as nylon and Tetron. Generally, the thermoformability of fibers is expressed as Pt (plasticity), and is expressed as "elongation at break / tensile strength x 100".
However, in the case of modacrylic fiber, the value is
The change is significant at temperatures above 120℃, approximately 80 times greater than at room temperature. Also, the energy that distorts fibers is called TI (toughness index), and if this value is small, less energy is needed to distort fibers during molding, resulting in better thermoformability, but for modacrylic fibers, TI with an elongation of 50% is Some fibers are about 1/10th the temperature at room temperature at 120℃, making them extremely easy to thermoform compared to other fibers.

The appropriate temperature for embossing is 80 to 160°C, but if it exceeds 140°C, the embossed surface will become hard due to melt hardening, change color, and deteriorate the texture and appearance. Therefore, the optimum processing temperature is 140°C or less, especially 100 to 130°C, and in this case, the texture of the concave surface B is smoothed while retaining the softness of the original fabric.

Therefore, the thermoforming temperature of the soft foam of the base layer that is integrated with the surface layer by embossing must also be within the range of 80 to 160°C, especially 100 to 160°C.
A temperature of 130℃ is optimal. From this point of view, soft foams include, in addition to the aforementioned 1,2-PBD foams, thermoplastic polyurethane elastomer foams, partially crosslinked ethylene-vinyl acetate copolymer foams, and soft (partially crosslinked) polyvinyl chloride foams. foam,
Other thermoplastic elastomer foams may be used.

In the present invention, the resin layer is limited to a soft foam in order to obtain a synthetic leather having a low modulus, rich in stretchability and elasticity, and having drapability without impairing the feel of the fabric. In the present invention, the concave portion is compressed to increase its density and become hard.
Therefore, a foam with a relatively high magnification (5 to 20 times) is required. In particular, in order to obtain a deep embossed pattern, the sheet must be thick, and in order to reduce weight, it is necessary and sufficient that the resin layer in the present invention be a foam. The thickness of the foam is preferably about 0.6 to 2.0 mm, although it depends on the expansion ratio. In addition, when foam bags made by laminating soft foam on fabric are embossed from the fabric surface, the fabric and the soft foam are molded at the same time, which buffers the thermoforming of the modacrylic fiber fabric and increases the molding expansion magnification. The hardness of large concave portions and small convex portions is almost the same. If the soft foam is embossed without backing, the concave portions will harden and the physical properties will change, resulting in a decrease in tensile strength and tear strength, making it unusable for practical use. Further, the great practical advantages of foam bags are that they have a warm feel, have heat retention properties, and are lightweight and easy to handle when used in portable items such as bags and bags.

As mentioned above, there are various kinds of flexible foams that satisfy these conditions, but in particular, 1,2-polybutadiene resin or a polymer blend containing this as one component is processed by, for example, an ultraviolet crosslinking method before foaming. Therefore, 1,2-PBD obtained by pre-crosslinking so that the gel fraction is within the range of 10 to 75% (gel fraction after 15 hours of boiling toluene) and then foaming by the blowing agent decomposition method. The foam has a suitable temperature for thermoforming of 80
-130°C, and it is one of the most preferable fibers because it can be heated dielectrically like modacrylic fibers. Furthermore, the foaming ratio can be freely changed over a wide range, and it has rubber-like behavior with high elasticity, permanent elongation, extremely low compression set, and good recovery properties, and is lightweight. However, it is also possible to use other flexible foams, such as flexible polyvinyl chloride foam, which is somewhat heavier but inexpensive. These foam laminates may be molded in a molding temperature range of 80 to 160° C. for modacrylic fibers in accordance with the softening point of each foam. In addition, these soft foams are desirably endless from the viewpoint of manufacturing efficiency, and need to be stretchable to prevent cracks from forming at the edges of the pattern during embossing.

On the other hand, adhesives for laminating fabric and soft foam include urethane, acrylic copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, etc., which have good adhesion between modacrylic fiber fabric and foam. An excellent one is preferably used. Also,
The backing material 7 that is adhered to the back surface of the foam is made of knitted material, woven material, or non-woven material, but these backing materials have the purpose of protecting the foam and increasing its physical strength such as overall tensile strength and tear strength. It is something that you have.

Next, in the synthetic leather 1 of the present invention, a paint layer 5 which can be said to be the surface of the natural leather surface and the grain layer.
I will explain about it. The paint used here is preferably a urethane or urethane-acrylic paint, since the paint film needs to have elasticity like the fabric 2 and foam 3. Moreover, the solvent type is a solvent (toluene,
DMF, etc.) attack modacrylic fibers, causing the surface of fabric 1 to darken and dyed items to change color.
An emulsion type is preferred. However, when methyl ethyl ketone (MEK) is used as a solvent, there is little risk of discoloration because MEK evaporates quickly.

Then, a paint using urethane or urethane-acrylic emulsion type or MEK solvent is applied to the surface of the fabric 2 using a spray, roll coater, direct coater, reverse coater, doctor knife, etc.
The synthetic leather is dried at a temperature of about 0.degree. C. and the surface of the fabric 2 is covered with a paint layer 5 as shown in FIG. 2. In this case, the amount of coating depends on the depth of the embossing, but it is 5 to 50μ as a dry film, usually about 10 to 30μ,
If it is too thick, it will look like vinyl leather and lose the characteristics of the invented product. On the other hand, if it is extremely thin (several microns), there is a problem with waterproofness, but the surface of the fabric has an elegant luster and transparency, giving it an appearance that is different from conventional synthetic leather or fabric.

Note that this paint layer 5 is not applied to the entire surface of the fabric as in the above example, but is applied only to the protrusions A, which are the surface of the fabric, or only to the recesses B, which is the smooth skin surface, as shown in FIG. You can. In this case, a silica-based matting agent may be added to the paint to make it translucent, or a paint mixed with a transparent pigment may be used to create mountain stains or valley stains. This allows the uneven pattern to be more clearly expressed. This colored paint can also be used for full surface coating.

On the other hand, this paint layer 5 can also be made into two layers consisting of an anchor coat 51 and a top coat 52 (FIG. 4). In this case, the anchor coat 51 uses an emulsion in which 7 to 3 parts of vinyl acetate or acrylic emulsion are mixed to 3 to 7 parts of urethane emulsion. When using this anchor coat 51, a solvent-based top coat 52 may also be used since there is no risk of changing the surface of the fabric. In addition, the vinyl acetate or acrylic emulsion acts as an adhesive to the fibers and acts as a bond with the urethane emulsion.
When applying both coats 51 and 52, the coating amount is 10
It is preferably about μ to 20 μ, or about 10 μ to 20 μ.

Next, the present invention will be explained in more detail with reference to examples.

<Example 1> Warp #40 single yarn 150 pieces/inch, weft #30 single yarn 65
A fabric (weighing approx. 160 g/m ² ) woven with 5 sheets of satin weave using yarn per inch (all products of Dal's modacrylic fiber "Kanekalon") is burnt on one side using a burner method, and then beamed with a cationic dye. After dyeing, the fabric was subjected to softening and water-repellent treatments to obtain a fabric with almost no fuzz and a glossy satin surface.
Next, the unburned side of this fabric was coated with an endless 1,2-PBD foam [trade name "Calsoft", manufactured by Takiron Co., Ltd.] (specific gravity 0.1 thickness 1 m/m).
were laminated using a two-component solvent type polyurethane adhesive using a reverse coater method. In addition, nylon tricot (40d/28G) was laminated on the other side of the foam using the same adhesive to obtain a foam laminate in which the middle layer was the foam.

This foam laminate was placed directly under a mold (in which a desired pattern with many relatively fine convex parts was engraved) fixed to the upper press plate of a high-frequency welder that had been preheated to 80°C. Feed with the plate facing up, immediately close the press and pressurize (approximately 30
kg/ ^cm2 ). At the same time, a high frequency of 13.56MHz is oscillated to raise the temperature of the pressurized part to about 120℃ and emboss it (2 to 5
seconds), then cooled at mold temperature (80° C.) for 2-5 seconds. After that, open the press and pull out the embossed fabric by the pitch of the mold (the cycle during this time varies depending on the embossed pattern, but it takes about 10
Embossing was repeated intermittently to obtain synthetic leather with a clear three-dimensional pattern and a gentle luster.

The convex portions of the synthetic leather either retain the original structure of the modacrylic fiber fabric as they are, or are deformed into a somewhat open state depending on the state of the pattern around the convex portions. In addition, the recesses embossed with fine patterns,
The fibers become soft or semi-molten to the extent that they hardly retain their original structure, and when the convex part of the mold is mirror-like and flat, a shiny skin appears (second
figure). The part that exhibits this skin condition can be called a special synthetic leather that has a completely different appearance from conventional synthetic leather or textile fabrics, and together with the flat surface of the fabric, the entire surface resembles a unique leather. Texture/
It gives a feeling. The embossed design gives the entire laminated body a relaxed, “bone” feel.
It is flexible, has no horns, has appropriate cushioning and drape properties, is lightweight, has a warm feel, and has an excellent surface abrasion resistance. In the case of other soft foams that cannot be heated by dielectric, normal heating methods such as infrared heating and hot air heating are used, but in any case, the pattern engraved on the mold is repeated. When the seams are eliminated, synthetic leather having a long three-dimensional repeating pattern is obtained.

On the other hand, if this embossing is carried out using a roll (there is a method in which the foam laminate is heated to a predetermined temperature and then embossed with a cooled roll, or a method in which the foam laminate is embossed with a roll that is heated at room temperature), there is a continuous embossing process. Processing becomes possible, which increases production efficiency, but unless the depth of the unevenness of the roll is greater than the thickness of the foam laminate, the convex surface of the embossed body, that is, the fabric surface, will also be heated and the entire surface will become glossy and contrasty, as if it had been calendered. There is a risk that it will disappear.

Next, the surface of the synthetic leather thus obtained was coated with approximately 35 g/ ^m2 of a transparent soft ultraviolet curing paint (manufactured by Sanyo Chemical Industries, Ltd.) using a reverse coater, and then heated with a 1KW high-pressure mercury lamp. It was cured by irradiating it for about 5 minutes from a distance of 30 cm. This material has a moderate degree of transparency, and has a three-dimensional appearance due to the shadows of the uneven pattern, giving it the image of a high-class product.

<Example 2> Synthetic leather obtained in the same manner as in Example 1 was coated with a polyurethane paint soluble in readily volatile methyl ethyl ketone and isopropyl alcohol (volume ratio 1:9) using a gravure coater [Honey Kasei Kogyo Co., Ltd. Co., Ltd.; product name 9039E] mixed with a predetermined amount of pigment [Number Color; Sanyo Shiki Co., Ltd.] is applied thinly to only the convex parts of the uneven pattern to remove the so-called stained multicolored surface. We created synthetic leather with These convex parts do not become hard because the polyurethane paint is extremely flexible, and do not impair the texture of the original synthetic leather.
In fact, the gloss has been increased somewhat, and the multicolored effect has increased the sense of luxury.

<Example 3> Anionic urethane emulsion [Elastron H-3 Catalyst 3] was added to the synthetic leather of Example 1.
%; produced by Daiichi Kogyo Co., Ltd.] mixed with a predetermined amount of Disperse Color [manufactured by Dainippon Ink & Chemicals Co., Ltd.] was applied thinly to only the convex portions of the uneven pattern, and heat treated at 90°C for about 10 minutes. As a result, a synthetic leather with a stained multicolored surface and good water resistance was obtained.

As detailed above, the synthetic leather of the present invention has a surface layer made of modacrylic fiber knitted fabric, which is a type of polyacrylic fiber, which has a relatively dense and thin texture, but whose surface has been fluffed. , on the fabric side of the foam laminate, which has a base layer of a soft foam made of thermoplastic synthetic resin whose molding temperature is similar to that of modacrylic fibers, the convex portions are on the fabric surface and the concave portions are on the smooth surface (depending on the embossed pattern of the mold, there may be multiple layers). The fabric has an embossed pattern (in some cases), and a thin layer of transparent or semi-transparent paint is applied to the entire surface or part of the fabric surface. Therefore, the surface layer has a deep and clear three-dimensional pattern, elegant gloss and transparency, and has excellent stain resistance and waterproof properties, and has the appearance and texture of both conventional synthetic leather and textile fabric. A unique feeling of being close to
Synthetic leather with good physical properties and excellent physical strength can be obtained, and can fully meet the recent demands for new materials.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of the synthetic leather of the present invention;
FIG. 2 is a partially enlarged sectional view taken along the line X--X in FIG. 1, and FIGS. 3 and 4 are partially enlarged sectional views showing other embodiments. 1...Synthetic leather, 2...Fabric, 3...Foam,
4... Foam laminate, 5... Paint layer, 6...
...Adhesive layer, 7...Reinforcement backing material, A...Protrusion, B
...Concavity.

Claims (1)

[Claims for Utility Model Registration] 1. A textile fabric made of modacrylic fibers whose surface layer is fluff-treated to prevent fluffing, and a soft thermoplastic synthetic resin having a molding temperature of 80 to 160°C. An embossed pattern is applied to the fabric side of the foam laminate with foam as the base layer, in which the convex portions are the fabric surface and the concave areas are the smooth surface, and a transparent or translucent urethane-based or urethane is applied to the entire or part of the fabric side. - Synthetic leather with a glossy cloth surface coated with acrylic paint. 2. Synthetic leather having a glossy cloth surface according to claim 1, which is obtained by staining the cloth surface with an embossed pattern with valleys or peaks with a paint containing a pigment. 3. Synthetic leather having a glossy cloth surface according to claim 1 or 2 of the utility model registration claim, which uses a paint containing a matte material and/or a transparent pigment.