KR100221602B1 - Artificial leather - Google Patents

Abstract

The present invention is an artificial leather composed of a microfine fiber bundle and a polyurethane elastic body, the fiber bundle is 3 to 4 denier having 20 to 80% by weight with respect to the ultra fine fiber of 0.1 denier or less and the total fiber weight, the length is 40 to 60mm To provide an artificial leather, characterized in that the stapled synthetic fibers, the artificial leather of the present invention is capable of expressing a variety of colors more than tricolor triangular has the advantage that is suitable as a material for fashion casual shoes.

Description

Artificial leather

The present invention relates to artificial leather, and more particularly, in artificial leather composed of a polar fiber bundle and a polyurethane elastic body, the fineness of the fiber bundle is 20 to 80% by weight with respect to the ultra fine fiber of 0.1 denier or less and the total fiber weight. It relates to artificial leather expressing a natural three-tone, characterized in that 4 denier, composed of synthetic fiber staples of 40 ~ 60mm in length.

Artificial leather is a material that is mainly impregnated with polyurethane resin or coated with non-woven fabrics, and is similar to natural leather in terms of its structure, functionality, and flexibility, but rather has excellent advantages that complement the shortcomings of natural leather. It is in the spotlight as an alternative material for.

In general, artificial leather is carded and cross-wrapped a special composite fiber that can be micronized, and then needle punched to make a three-dimensional entangled nonwoven fabric. It is prepared by manufacturing.

Such artificial leather is roughly divided into suede artificial leather and silver artificial leather. Suede artificial leather is manufactured by buffing the leather sheet and raising the surface layer, followed by dyeing and post-processing to form a wool layer on the surface. Mainly used for clothing, young, gloves, miscellaneous goods. Silver-type artificial leather is manufactured by forming a two-layer structure by wet or dry coating a polyurethane solution on a leather-like sheet and then embossing or laminating a polyurethane film made on a release paper having a pattern. It is mainly used for outer shell, ball outer shell, seat cover, etc.

Looking at the manufacturing method of the conventional artificial leather in more detail, by manufacturing a non-woven fabric consisting of microfiber only and shrinking it in steam or hot water to increase the density, and then filled with a water-soluble polymer such as polyvinyl alcohol or carboxymethyl cellulose, the form of nonwoven fabric Stabilize. Next, the dimethylformamide solution of the polyurethane elastomer is impregnated, coagulated in water and washed with water to fill the microporous polyurethane elastomer inside the nonwoven fabric. Subsequently, the temperature is raised to completely remove the filled water-soluble polymer, and then dried to remove the sea component to make the fiber fine. Finally, the sandpaper is buffed with a buffing machine, dyed, and processed into artificial leather. However, the conventional artificial leather is composed of two different materials of polyurethane and fiber, so it shows two-tone effect when dyed, but it is restricted to the expression of various colors more than tritone, so it is used for casual shoes. As a result, there was a limit in giving fashion when developing a use.

Accordingly, an object of the present invention is to provide an artificial leather capable of expressing various colors of tricolor or more.

That is, the present invention is an artificial leather composed of a microfine fiber bundle and a polyurethane elastic body, the fineness of 3 to 4 denier of 20 to 80% by weight with respect to the ultra fine fiber of 0.1 denier or less of the fiber bundle and the total fiber weight, 40 ~ length It is to provide an artificial leather, characterized in that consisting of 60mm synthetic fiber staples.

Hereinafter, the present invention will be described in more detail.

The artificial leather of the present invention is a non-woven fabric manufacturing step by mixing a very fine staple fiber and a regular yarn (synthetic fiber) staple fiber in a non-woven fabric after a series of post-processing and as a result, the pre-dye is a fine yarn, general yarn It is characterized in that it is composed of three materials, and polyurethane. Therefore, in the artificial leather of the present invention, the apparent color difference is generated by dyeing speed, dyeing degree and fineness difference of each material during dyeing to express tricolor tone.

In the present invention, it is preferable that the mixing ratio of the microfine-use staple fiber is 50%, but when the mixing ratio is less than 50% or more than 50%, there is no uniform tritone expression. In the present invention, nylon is preferably used as the general yarn staple fiber.

In the present invention, if the composition ratio of the synthetic fiber staple is less than 20% by weight with respect to the total fiber weight, it becomes closer to the dichroic tank and the mixing difference for each site is intensified to generate the color difference for each site. If it exceeds 80% by weight, the feel of the forge becomes hard and rough. Therefore, the composition ratio of the synthetic fiber staples in the present invention is essential to be within the above range.

In addition, the fineness of the synthetic fiber staples used in the present invention is preferably 3 to 4 denier, and if the fineness is less than 3 denier, the touch becomes hard and the microfiber composite fibers and fineness difference are increased, so the opening and mixing properties of the nonwoven fabric are increased. In the case of lowering, color difference for each part occurs in the final product, and the fineness exceeds 4 denier, the touch of the forge is not smooth and rough, which is not preferable.

The length of the synthetic fiber staples used in the present invention should be 45mm ~ 60mm, if the length is less than 45mm, opening and mixing properties during the manufacturing of the sub-pore decreases color difference for each part in the final product, 60mm in length If it exceeds, the touch of the forge becomes rough.

Artificial leather of the present invention can be produced, for example, by the following method.

First, the microfiber composite fiber usable in the present invention is a composite spinning or mixed spinning of two kinds of polymer materials capable of forming filaments in the form of sea / doe (海 / 島). As the island component, a modified polyester in which the crystallinity of the yarn is adjusted to less than 35% by copolymerizing a macromolecular molecule composed of an aromatic chain in the polyethylene terephthalate backbone is used. As the copolymerization component, 2,2-bis- (4- (2 -Hydroxyethoxy) phenol) propane, 2- (4- (2-hydroxyethoxy) phenol) propane, or 2- (4-2- (2-hydroxyethoxy) ethoxy) phenol) propane It is possible to use. As the sea component, copolyester, polystyrene, polyethylene, and the like, which have different solvent soluble properties and solvents, may be used.

On the other hand, the ultrafine composite fiber used in the present invention is advantageous to obtain flexibility, strength, and fidelity of bubbles when the fineness after the micronization is 0.5 denier or less, particularly 0.1 denier or less. In the present invention, such a composite fiber is mixed with a common yarn staple fiber 50:50 to open, carded by a conventional nonwoven fabric manufacturing method, laminating the web to the desired weight and then needle punched to produce a three-dimensional interwoven fabric.

Subsequently, when the needle punched nonwoven fabric is shrunk by hot water, steam, or dry heat, the apparent density of the nonwoven fabric is improved, resulting in a more compact state.

The contracted nonwoven fabric is then stabilized by padding the nonwoven fabric with a water-soluble polymer solution such as polyvinyl alcohol or carboxymethyl cellulose at a concentration of 3 to 15% and drying to give 5 to 10% by weight of the fiber. This process is effective not only to stabilize the shape of the bubbles, but also to prevent the subsequent wet processing polyurethane from excessively adhering to the fiber bundle and hardening the touch.

Next, a polyurethane wet impregnation is performed on the nonwoven fabric. Polyurethane elastomers used in this process are readily dissolved in dimethyl formamide (DMF) as linear polymers composed of macro glycols, diisocyanates and low molecular weight diols with molecular weights from 500 to 3,000. As the polyurethane elastomer used in the present invention, polyether glycol, polyester glycol, polyether polyester copolymer glycol, polycarbonate glycol, and the like are applicable as macroglycol, and as diisocyanate, usually 4,4'-diphenylmethane Diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate or 4,4'-dicyclohexyl methane diisocyanate. In the present invention, as the low molecular weight diol, 4,4'-butanediol, ethylene glycol, and the like are used, and a diamine-based chain extension agent is also applicable. A surfactant, a coloring pigment, an antioxidant, and the like are added to the DMF solution of the polyurethane elastomer to be used as an impregnation solution. After impregnation, the polyurethane is solidified in the non-solvent system or the non-solvent and solvent mixture system of the polyurethane, washed with hot water at 50-70 ° C, completely removed the water-soluble polymer filled, and then dried. Flexible elasticity, denseness is expressed, and a feeling of filling like natural leather is given.

The amount of polyurethane given at this time depends on the concentration of the impregnation solution, the gap between the padding roll, and the density of the nonwoven fabric to be treated. Therefore, it is necessary to adjust it to suit the required characteristics of the final bubble. It is preferable to set it as 100 parts.

Next, the sea component is removed by the alkali reduction method to perform an ultrafine process of the microfiber composite fiber. At this time, if the sea component is copolymerized polyester, the sea component is decomposed by treating with 5-15% caustic soda solution in a continuous or batch manner, and if the sea component is polyethylene or polystyrene, it is removed with toluene or perchloroethylene. do. For example, the sea component copolyester is completely decomposed and removed by treatment with a 5% aqueous caustic soda solution at 95 ° C. for 20 to 50 minutes. At this time, the nonwoven fabric has some thickness reduction due to the removal of the sea component, but the shape is maintained and the elongation in the longitudinal direction due to the mechanical tension is not large.

Next, the surface of the leather-like sheet thus obtained is buffed by a buffer equipped with sandpaper of appropriate roughness to prepare surface wool. Subsequently, when the fiber used is polyamide, it is usually dyed with an alloy dye or millipper acid dye, and in the case of polyethylene terephthalate, it is dyed in a high pressure rapid dyeing machine with a disperse dye. At this time, since the initial dyeing speed of the ultrafine fiber is very large, in order to achieve uniformity of the dye, it is necessary to pay attention to the homogeneity of the dye type, the type and method of the leveling agent, and the setting of the temperature raising condition. Lastly, functional preparations such as softeners, water repellents, and antistatic agents are processed to produce tricolor artificial leather.

The artificial leather manufactured by the present invention is made of three materials before dyeing, and apparent color difference occurs due to dyeing speed, dyeing degree, and fineness difference of each material. It is very suitable as a material for casual shoes.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the following Examples.

Example 1

The microfiber staple fiber was made of 65 parts of nylon-6 as a island component, and 35 parts of copolyester as a sea component to prepare a composite fiber staple having a length of 2 inches, a fineness of 3 deniers, and a crimp number of 12-18 pieces / inch. At this time, the number of island components was set to 36 pieces per filament. In addition, general yarn staple fiber produced a nylon staple fiber of 2 inches in length, 1.5 denier fineness, 12-18 pieces / inch crimp number. The two fibers were mixed at 50:50, opened, carded, and needle punched to produce a three-dimensional entangled nonwoven fabric. The nonwoven fabric was shrunk with 100 ° C. steam for 5 minutes, the polyvinyl alcohol aqueous solution was padded on the nonwoven fabric and dried to stabilize its shape. Then, the dimethylformamide solution of the polyether-based polyurethane elastomer was impregnated into the nonwoven fabric sheet. After coagulation with water, it was washed with water and dried in a conventional manner.

Subsequently, alkaline-reduced processing was carried out with a 10% aqueous solution of caustic soda to elute the seaweed components of the composite fibers, washed with water and dried to make the fibers extremely fine. At this time, the ultrafine two-component composite staple fiber was microfiberized to about 0.05 denier. At this time, the thickness of the forge was 1.66 mm and the content ratio of fiber to polyurethane was 63:37. The paper was buffed with sandpaper to uniform the thickness to 1.4 mm and then dyed under the following conditions.

(1) Dyeing temperature and time: 98 ℃ × 60 minutes

(2) Additives during dyeing: * Leveling agent: 0.5% o.w.f.

* pH adjuster (acetic acid): pH 4.5

(3) Fixing agent (Polyfix: manufactured by Korea Fine Chemicals Co., Ltd.): 5% o.w.f.

(4) Dye: Acid dye (C.I. Acid Navy 57): 10% o.w.f.

Acid dye (C.I. Acid Yellow 42): 0.5% o.w.f.

After dyeing, 400 mesh sand paper was buffed to prepare the artificial leather of the present invention by cleaning the surface and the back surface and treating the softener and the water repellent agent. The obtained artificial leather expresses a natural three-tone and is suitable for casual shoes.

Claims (2)

In artificial leather composed of an ultrafine fiber bundle and a polyurethane elastic body, the fiber bundle has a fine fiber of 0.1 denier or less and a fineness of 3 to 4 denier having 20 to 80% by weight of the total fiber weight, and a synthetic fiber staple having a length of 40 to 60 mm. Artificial leather, characterized in that consisting of. The artificial leather of claim 1, wherein the synthetic fiber staples are nylon 6 staples.