KR900008705B1 - Method for the preparation of grain face artificial leather - Google Patents

Abstract

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Description

Manufacturing method of silver artificial leather

The present invention relates to a method of manufacturing a silver artificial leather useful for clothing, and more particularly, by coating a plasticized polymer elastomer on a flexible leather sheet to form a surface coating layer, thereby providing excellent touch, moisture permeability and surface pattern. In particular, the present invention relates to a method of manufacturing artificial leather suitable for clothing.

In general, polyurethane elastomer, a polymer elastomer used in artificial leather, is composed of a soft segment acting as an elastic component and a hard segment acting as an inelastic component, and a strong hydrogen bond between the action of the elastic component and the molecular chain. Due to this, the elongation and elastic recovery rate of the polyurethane elastomer are very high.

Such a high elastic recovery rate is deteriorated in physical properties by applying a polyurethane elastic body to a silver artificial artificial leather, due to the high rebound elasticity, such as dull shrinkage due to rubber.

In addition, when wet molding a polyurethane elastic body, in the drying process, since 20% or more of the area is twisted due to shrinkage, it has been the biggest drawback in the manufacturing of conventional silver artificial leather.

In addition, Japanese Laid-Open Patent Publication No. 58-42305 discloses a method of coating and laminating a polymer elastic body that is a microporous coating alone on a leather sheet, but in this case, the flexibility and surface coating layer of the ultra-fine leather sheet are obtained. Due to the lack of balance with rubber resilience, there is a problem in that the touch is not excellent.In addition, the Japanese special offices 47-48505, 48-30361, 58-42305, and 60-28304 release the microporous membrane by the wet processing method. Alternatively, a method of coating on a polyethylene film, stretching the shrinkage upon drying by about 10% in the axial direction, laminating the leather sheet, and mixing a low molecular weight polyurethane solution to produce a wet film to laminate the leather sheet. These methods suggest that certain methods can be established between the leather sheet and the surface coating polymer elastomer. Although it is balanced, the rubber resilience of the surface coating layer still remains, and the use of adhesives, such as the low moisture permeability and the touch gives a feeling of a slight stiffness. In addition, Japanese Patent Office 60-17892, 60-34676, etc., describes a method of manufacturing a silver artificial leather, in which a polymer elastic body is formed into a nonporous thin film and then bonded to the leather-like sheet by a dry method. It has been pointed out that there are drawbacks of reduced moisture permeability and lack of surface abrasion resistance by the dry air layer.

In order to solve these problems, in the present invention, a polyvinyl chloride copolymer or a polyvinyl acetate polymer plasticized with a plasticizer such as dioctylphthalate is mixed with a polyurethane elastomer used as a surface coating layer, and the surface is formed by wet coating. It was found that the elastic properties of the coating layer were alleviated and the modular group of the leather-like sheet composed of the ultrafine fibers and the polyurethane elastic body was maintained to significantly reduce the kink and shrinkage during molding.

Therefore, an object of the present invention is to reduce the rubber properties of the high rebound elastic polyurethane by plasticizing the polyurethane elastic body with polyvinyl chloride or the like when the polyurethane elastic body is coated on the leather-like sheet to produce a silver-faced artificial leather, In addition, it provides a manufacturing method of silver-type artificial leather for clothing, which has a soft feeling, no tangling phenomenon, and excellent moisture permeability and surface pattern sharpness without reducing rubber shrinkage during drying.

Hereinafter, the present invention will be described in detail.

The present invention is to form a surface coating layer by coating a polyurethane elastomer solution on one surface of a leather-like sheet consisting of a nonwoven fabric and a polyurethane elastic body, and to form a silver artificial artificial leather by embossing after coagulation, washing and drying. The composite fiber is composed of 0.5 to 0.001 denier, and the surface coating layer polyurethane elastomer is composed of a solution of polyvinyl chloride dissolved in dioctylphthalate or dioxadiate-based plasticizer in 100 parts of a polyurethane solution having a solid content of 30%. It is characterized by the production of silver-faced artificial leather by using 20 parts made of a plasticized surface coating layer made of polyurethane elastomer.

Referring to the present invention in more detail as follows.

The present invention is a laminated sheet composed largely of a nonwoven fabric and a polyurethane elastic body, and the sub-foam is a sea island-type composite fiber that can be micronized to 0.5 to 0.001 denier, and the polyurethane elastomer solution forming the surface coating layer is a one-component type having a solid content of 30%. A mixture of 2 to 20 parts of plasticized polyvinyl chloride polymer in 100 parts of dimethylformamide solution of linear polyurethane elastomer is used, wherein the plasticized polyvinyl chloride polymer is used in 30 parts to 50 parts of plasticizer of polyvinyl chloride polymer. In addition, it is good to use it as the paste resin which mixed 0.5-2 parts of stabilizers.

On the other hand, the polyurethane used in the present invention is a dimethyl formamide soluble polymer elastomer obtained by reacting an ester or ether type glycol having a molecular weight of 1300 to 2000, 4, 4'-diphenyl methane diisocyanate and a diol or diamine chain extender, This elastomer and its properties are 30-50 kg / cm 2 of 100% modulus, 50-180 ° C. of softening point, and the mixed polyvinyl polymer of the polyurethane elastomer is a polyvinyl fluoride soluble in a plasticizer and has a main composition of 700-1700. According to the kind of plasticizer, there is little change of viscosity with time, high heat resistance and suspension polymerization, and excellent compatibility with dimethylformamide solution.

Table 1 below compares the physical properties of the polyurethane elastomer solution alone film with the physical properties of 10 parts of a plasticized polyvinyl chloride polymer resin plasticized to 100 parts of the polyurethane elastomer solution. In Table 1, it can be seen that the elastic recovery rate of the blended (A film) was 70 to 80%, which was considerably alleviated than that of polyurethane alone. It also shows that the shrinkage in film forming is also significantly reduced.

TABLE 1

The thickness of the wet film. 200μ

A… Wet film of polyvinyl polymer + polyurethane polymer

B… Polyurethane Single Wet Film

Meanwhile, in order to manufacture the flexible leather-like sheet of the present invention, a special island-in-the-sea composite fiber is used as a nonwoven fabric, and a polyurethane elastic body is filled by a wet processing method in a three-dimensionally interwoven nonwoven fabric, and the fiber and the filled polyurethane elastic body are filled. Does not directly adhere to form voids, and the polyurethane elastomer is microfabricated by the wet process. In this case, the island-in-the-sea composite fiber is denatured into an ultrafine fiber by chemical treatment to have an average fineness of 0.5 to 0.001 denier after modification. The ratio of fiber to polyurethane elastic body in the leather sheet is 70/30 to 40/60, and the leather sheet of the present invention is characterized in that the microfiber of the fiber, the pores between the fiber and the polyurethane elastic body, the micropores of the polyurethane elastic body, etc. Due to this, the touch is soft and exhibits the appearance and function of natural leather with excellent physical properties.

The leather sheet is adjusted to a thickness of 0.6 to 1 mm, suitable for clothing, and then coated on one side with the plasticized polymer solution mentioned in the present invention, solidified and washed to form a film layer having a thickness of 10 to 50 µm. . Next, after fixing the coated surface with heat and pressure using an embossing roll, the desired surface pattern is expressed on the coated surface, thereby increasing durability of the coated film.

In the manufacture of such artificial leather, the polymer elastic body, that is, the polyurethane elastic body, which is the surface coating layer, has a thickness of 10 to 50 μm, the hemispherical plasticity of the coating layer alone is 80% or more, and 100% extension for 3 minutes It is preferable to use an elastic recovery rate of 65 to 85% at the time of removal, and a wet shrinker area shrinkage of 10% or less.

In addition, the island-in-the-sea composite fiber used as a nonwoven fabric in the leather sheet is preferably polyethylene terephthalate or nylon 6 as the island component, and polyester, polystyrene, polyethylene, or polyamide as the sea component. The silver-type artificial leather manufactured in this way exhibits a soft touch and appearance due to wet processing, and the rebound elasticity is alleviated by using a plasticized coating layer, so there is no rubber feeling, the surface pattern is clear, durability is excellent, and moisture permeability is excellent. It showed various characteristics suitable as artificial leather for clothing.

Hereinafter, the present invention will be described in detail with reference to Examples.

Example 1

A sea island type ultrafine fiber staple fiber having a fineness of 3 denier and a length of 51 mm to 70 mm was prepared using 60 parts of nylon-6 as a island component and 40 parts of polyethylene as a sea component. A web was formed from this fiber and needle punched to produce a three-dimensionally tightly interwoven nonwoven fabric with a weight of 150 g / m 2 and a thickness of 2.2 mm apparent density of 2.34 g / cm 3. Heat shrinkage, heat-press (Heat-press) and dried to fill the ether-based polyurethane with 100kg modulus of 40kg / ㎠ and to remove the marine polyethylene by toluene. At this time, the ratio of microfibers / elastics is 65/35, and the fibers and the filling elastics do not directly adhere to each other to maintain a constant void, and the filling elastics also form fine processing by wet processing, which is excellent in flexibility and touch. Next, the front and back areas were removed with a slicing machine, and then bisected into 0.6 mm to produce a leather-like sheet. The calender roll gave smoothness, and at the same time, 100% modulus of the sliced surface was 30 kg / ㎠ and a softening point of 150 ° C. 22.12 parts of ester ether copolymer polyurethane elastomer, 61.8 parts of polyvinyl chloride having a degree of polymerization of 1300, 37.2 parts of dioctylphthalate as a plasticizer and 4 parts of stabilizer, 4.47 parts of a solution, 0.27 parts of hydrophilic surfactant, 0.37 parts of hydrophobic surfactant, 3.67 parts of silica gel, dimethyl The solution for the coating layer consisting of 69.1 parts of formamide was apply | coated with a coater, it solidified in 30 degreeC-40 degreeC water, wash | cleaned sufficiently in water of 50 degreeC-60 degreeC, and dried at 100 degreeC.

Next, the surface was heat-set with a kid pattern having a temperature of 130 'to 140 ° C and a pressure of 3.5 kg / cm 2 using an embossing roll. The artificial leather for the silver-type garment thus obtained has a weight of 297g / cm 2 and thickness of 0.63mm, and the resilient elastic recovery is similar to calf, and the recovery angle after 55 minutes is 55 ~ 80 °, and the touch and appearance are excellent. It was.

Comparative Example 1

It is the same as that of Example 1 except the coating elastic body apply | coated and laminated | stacked on the leather sheet was apply | coated and the polyurethane solution which has the same characteristic as Example 1 was apply | coated.

Comparative Example 2

An elastic body laminated on the leather sheet is a wet film having a thickness of 40 µ obtained by applying a polyurethane solution used in Comparative Example 1 alone on a polyethylene film, except that it was laminated using a one-component polyurethane adhesive on the leather sheet. Same as 1

The embossing conditions in Example 1 and Comparative Examples 1 and 2 are the same and are shown in Table 2 by comparing the characteristics of the manufactured artificial leather.

TABLE 2

(Note) * The numerical value by kender lever method is small, so it is flexible.

** Sensory test results of 5 artificial leather technicians

*** Irradiation after 10 days at room temperature after manufacture

As can be seen from the above table, it can be seen that the technique of Example 1 is superior in moisture permeability, touch, and surface pattern sharpness as compared to Comparative Examples 1 and 2.

Claims (1)

The surface of the leather-like sheet composed of a nonwoven fabric and a polyurethane elastomer is coated with a polyurethane elastomer solution to form a surface coating layer, and solidified, washed, dried and embossed to produce a silver-cotton artificial leather. It is composed of 0.5 to 0.001 denier, and the surface coating layer polyurethane elastomer is mixed with 2 to 200 parts of a solution in which polyvinyl chloride is dissolved in dioctylphthalate or dioctyl adipate-based plasticizer in 100 parts of polyurethane solution having a solid content of 30%. A method for producing a silver artificial leather, characterized in that it is manufactured by using a plasticized surface coating layer made of a polyurethane elastomer.