JPS60224880A - Preparation of artificial leather - Google Patents

Abstract

PURPOSE:To obtain a suede-like leather having blight hue and a soft feeling, by providing a substrate consisting of woven or knitted cloth or nonwoven fabric with a high polymer elastomer, pressing the polymer in such a way the surface layer is not formed so that the polymer is transferred to the central part of the substrate. CONSTITUTION:One surface of a substrate consisting of woven or knitted cloth or nonwoven fabirc is provided with 5-40wt% based on the weight of the substrate of at least one polymer selected from a high polymer elastomer and a nonrigid synthetic resin, the substrate is passed through nip rollers so that the polymer is transferred to the central layer of the substrate, and the polymer is coagulated in a dry or wet method. Before and/or after the coagulation, the surface of the substrate is buffed and napped into a suede tone. Dyeing and processing of the substrate may be carried out in any stages. Pile woven or knitted cloth, etc. comprising conjugated fibers of separable type dividable into each segment at least in a napped part is preferable as the substrate.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing suede-like fake leather.

Conventionally, as a method for making suede-like fake leather, a base material made of woven or non-woven fabric is coated with a resin such as polyurethane, acrylonitrile-butadiene rubber (NBR), or styrene-butadiene rubber (SBR), and then filtered. There are several methods of obtaining suede-like artificial leather that has a unique appearance that cannot be obtained from natural leather by using puff ink to completely increase surface fluff and surface smoothness, and then dyeing. In particular, a method in which a continuous microporous skin is formed on a base material by a wet film forming method using urethane, and then a suede-like texture is created by puff inbrewing is preferred in terms of excellent hand feel.

However, in the method described above, after the ink is puffed and fluffed, the remaining polymer layer appears patchy between the fluffs. Since the polymer layer cannot have the same hue as the base fiber, the polymer, which looks microscopically mottled, ends up making the base as a whole have a completely uniform hue.

The present invention was completed as a result of intensive research to solve all of these drawbacks.

That is, the present invention involves applying at least one kind of polymer selected from a polymer elastomer and a soft synthetic resin to a base material made of a knitted woven fabric or a non-woven fabric, and then dry coagulating or wet coagulating the polymer. In a method of producing suede-like leather, which includes fluffing the VC surface before and/or after the process, the polymer is applied to one surface of the substrate and then pressed so that the polymer is applied to the surface of the substrate. A method is provided which is characterized in that it transfers from the intermediate layer to the intermediate layer and then performs surface processing.

In the present invention the polymer is applied onto one side of the substrate, for example by coating. The polymer can be used by itself or in the form of a solution, emulsion, etc., but in any case, after application, the polymer remains close to the surface layer without substantially penetrating into the intermediate layer of the substrate. .

This is transferred to the intermediate layer of the entire polymer matrix by nipping and pressing, for example with suitable rollers. At this time, if you press too hard, the polymer will break from the opposite surface VC.
It's not good because it reaches up to that point. The appropriate pressure to be applied depends on the viscosity of the polymer, the affinity between the base material and the polymer liquid, the roughness of the base material, etc., and can be easily determined by those skilled in the art by testing each time. For example, 5//an from 10 to 60
may be preferred. However, it is not limited to this range.

The polymer thus transferred to the intermediate layer of the base material is solidified according to a conventional method. On the other hand, in order to obtain a suede look, the surface opposite to the surface to which the polymer is applied (or to be applied) is fluffed before or after the polymer application M hardening step, or before and after the polymer hardening step. After light fluffing, the polymer is applied and solidified.The substrate can be dyed at any stage.

According to the invention, no polymer is present in the surface layer near the fluffed surface, so even if the polymer is not dyed to the same degree as the fibers, this does not impair the color of the fluffed surface.

If, as in the present invention, the polymer is applied to one side of the substrate but is not suppressed, the dyed hue of that side will not become dull because the polymer will not reach the opposite side. However, since the coating surface is flat, it feels cheap. Also, the texture is hard, ruining the suede feel.

Products made according to the method of the present invention not only have vivid colors, but also have extremely favorable textures. Therefore, even when color retention is not a particular problem, the method of the present invention is suitable for producing suede-like leather.

As the base material in the present invention, base materials that are normally used for manufacturing fake leather can be used. However, in particular, two types of fiber-forming polymers with low mutual adhesion are joined along the longitudinal direction, and segments of one component (A) branching radially in the cross section of the other component (B) are bonded together in the longitudinal direction. K A pile knitted fabric or a raised knitted fabric in which splittable composite fibers separated into at least three segments constitute at least the napped portion is subjected to chemical treatment and/or heat treatment to swell and swell the fiber-forming polymer. At the same time as collecting the composite fiber and dividing it into each segment, or after the division,
It is also possible to use a material obtained by shrinking this in area by 10 inches or more (Japanese Patent Publication No. 55-20561).

In this case, after application and coagulation of the polymer, the entire raised surface of the substrate is polished to fluff it. Furthermore, it is also possible to use a nonwoven fabric made of splittable conjugate fibers as described above and a base material obtained by splitting and shrinking rainbow conjugate fibers in the same process as described above (Japanese Patent Publication No. 55-57456). In this case, the puff KL can be fluffed after application and coagulation of the polymer.

Examples of the polymer include polyurethane, polyamide resin, vinyl chloride resin, acrylic resin, etc. Among them, polyurethane elastomers are preferred. Further, if necessary, a crosslinking agent, a coloring agent, a filler, a light stabilizer, etc. may all be mixed together.

The polymer itself or a solution, emulsion or paste resin containing the polymer may be applied to the substrate by any commonly used method such as coating or spraying. The amount applied is 5 to 50%, preferably 5 to 40% (weight! Ik) based on the weight of the base material as polymer solid content.
It is. If the applied amount is less than 3% by weight, the leather will not have enough strength and the texture will be poor, while if it exceeds 5% by weight, it will lack flexibility and have a rubber-like texture, which is undesirable.

As a method for coagulating the polymer, a dry method in which the solvent is directly evaporated (so-called dry coagulation method), or a wet coagulation method in which the polymer is coagulated by immersion in a coagulating liquid is adopted. After wet coagulation, it is washed with water to remove all the solvent, and then dried. The latter is preferred in order to make the solidified fcst fat layer retain the pores and have flexibility. Examples of the coagulating liquid used in the wet coagulation method include water, a mixture of dimethylformamide and water, and an aqueous solution of an inorganic salt (salt, sodium sulfate, ammonium sulfate).

Thus, according to the present invention, the color is altered and the hue becomes dull due to the normally porous polymer present in the surface layer, which is a problem with suede-like simulated leather that is coated with polymers using conventional padding or coating methods. The coated surface (back side) is flat, with no cracks, and there is no deterioration in quality or hardness due to I/C, making it possible to obtain suede-like faux leather that is extremely flexible and has a clear color tone. It is.

In the following, the present invention 1 will be explained with reference to examples.

The base material used in the examples was obtained as follows. In other words, the filament has a cross-shaped 6-Nyro/
Split type composite filaments (50 denier/28 filaments) made of polyethylene terephthalate (50 denier/28 filaments) filling the gap and having a circular filament cross section were knitted into fabrics as a back system and a front system using a 28-gate tricot knitting machine. Next, after sufficiently raising the fluff using a bullion needle cloth raising machine, the above-mentioned splittable composite fiber was divided by treatment with benzyl alcohol t/C and the silk fabric was shrunk (%
Publication No. 55-20561 Example 1). This was dyed using a conventional method and used as a base material.

100 Scenery 1 Polyu v Tough (0RISVON 8
166=Registered trademark, manufactured by Dainippon Ink Chemical, solid content 50%
), 20 parts by weight of dimethylformamide, and a small amount of a coagulating agent for making FA. The resin magnetism in the liquid is 25% by weight, and the viscosity of the liquid is 20,000 cp.
s (25°C).

One side of the above substrate is coated with the above resin solution using a doctor knife (4-thickness). The resin remains near the surface of the coated substrate.

Next, the substrate is passed through a pair of nip rollers. Line pressure approx. 50
kg and 7 cm. After nipping, the polymer is wet coagulated by soaking in 40°C water, followed by washing and drying. This was inked and brushed in the usual way.

The obtained central product had a bright hue and a good texture.

Agent Hikaru Esaki Agent: Hikaru Esaki

Claims (1)

[Claims] 1. Dry coagulation or wet coagulation after applying at least one type of polymer selected from polymeric elastomers and soft synthetic resins to a base material made of knitted or nonwoven fabric, and before and/or after this step. In a method of producing suede-like leather that includes raising the surface, the polymer is applied to one surface of the substrate and then pressed to transfer the polymer from the surface of the substrate to the intermediate layer. A method characterized by performing a coagulation treatment afterwards.