KR950013195B1 - A method for preparation sinthetic leather - Google Patents

Abstract

The synthetic leather is produced by (a) wet coating a polyurethane resin composition composed of 40-50 wt.% polyurethane resin, 40-50 wt.% dimethyl formamide(DME) as a diluting solvent, 1-3 wt.% anion surfactant, 1-3 wt.% nonion surfactant, 2-10 wt.% resin coloring pigment and 5-20 wt.% cellulosic filler(KC floc) on a woven, knitted or non-woven fabric, (b) solidifying, washing and drying the coated fabric, (c) bonding the fabric to a base cotton fabric with an acryl, polyurethan or polyester adhesive, and (d) stripping of the fabric to form a micro cell of the polyurethane resin on the surface of the base fabric.

Description

Manufacturing method of synthetic leather

The present invention relates to a method for producing synthetic leather having a texture similar to natural leather and having excellent gloss and functionality. Conventional synthetic leather is applied to the polyurethane resin composition on the fabric, such as woven, knitted or non-woven fabric to form a silver surface layer, by polishing or embossing the surface of the silver surface layer gave a texture and functionality similar to natural leather.

In other words, the conventional method of manufacturing synthetic leather was an attempt to approach natural leather in post-processing after the formation of a silver layer, so that there was a lot of problems in expressing the soft texture, gloss, and functionality which are the characteristics of natural leather.

The present invention has solved such a problem, and the polyurethane resin microcell (Micro Cell) by wet coating the polyurethane resin composition on the forge, solidified, washed with water and dried and then peeling the forge after combining it with a bubble paper and an adhesive. ) To be formed, which will be described in detail below.

The present invention prevents the coating from excessively infiltrating into the back side of the forge when wet coding by padding a cloth such as a woven, knitted or nonwoven fabric with an aqueous solution of 10 to 30% of dimethyl formamide (DMF). Make sure that the adhesive strength between and forge is maintained properly.

Subsequently, 40-50 wt% of polyurethane resin, DMF 40-50 wt% of diluent solvent, 1-3 wt% of anionic surfactant, 1-3 wt% of nonionic surfactant, 2-10 wt% of resin coloring pigment and cellulose filler The coated polyurethane resin composition was wet coated on the surface of the forge treated as described above.

The filler used in the present invention is a pulverized product of cellulose that is light, has excellent thermal stability, is stable to solvents such as strong acids and strong alkalis, and has hydrophilic radicals.

This cellulose ground material was K. floc (pulp product) and 5-20% of the weight ratio was added.

If the input amount exceeds 20wt%, there is a problem of operability due to the increase in moisture content, and if it is less than 5wt%, the effect is insignificant.

The characteristics of KC floc are 7% water content, particle size of 20-400 mesh, whiteness is at least 80% and hydrogen ion concentration is 10 ^-7 .

The higher the whiteness is, the higher the whiteness is for obtaining a vivid color.

KPC is manufactured as follows. That is to say, pure pulp is filtered by hydrolysis, washed, dehydrated, dried, pulverized and filtered to a suitable size to make powder of 20 to 400 mesh, especially 300 mesh.

At this time, when the size of the particles is too large, it is difficult to coat and poor in terms of liquid stability. Since the KC floc used in the present invention has excellent hygroscopicity, it also has a function of very uniformly dyeing or dispersing a hydrophilic dye or pigment in a state in which it is relatively uniformly dispersed in the resin layer.

In addition, the KCC has repulsive elasticity due to the characteristics of the pulp, and thus exhibits a property of restoring the silver layer immediately to its original state when the pressure applied to the silver layer is removed. In addition, unlike the silver layer applying inorganic fillers or other fillers, it gives a very flexible texture.

The reason for this is that the case where the CCC has a high water content, even if present in a dispersed state in the resin of the silver surface layer does not come into direct contact with the resin, thereby forming more voids in the silver surface layer. As described above, the wet coated coated paper with the polyurethane resin composition is coagulated, washed with water and dried, and then bubbled with a bubble paper and an adhesive made of woven, knitted or nonwoven fabric.

The adhesive agent used at this time may use any of normal acrylic type, polyurethane type, and polyester type.

When the forge is finally peeled from the one produced as above, a micro cell of a polyurethane resin is artificially formed on the surface of the bubble paper.

Example 1

The fabric forge is passed through an impregnation bath where water and DMF are mixed at 6: 4 and then squeezed at 4Kg / cm ² .

The over was then coated using a coater at a speed of 5 m per minute.

At this time, the distance from the surface of the fabric cloth was set to 500μm and the resin composition was used in Table 1. After coagulation for 5 minutes in a solidification bath at room temperature, washed with water for 10 minutes in a 60 ℃ washing tank and dried for 5 minutes by hot air at 160 ℃.

The above-mentioned thing was combined with the bubble paper of the cotton fabric of the weft density of 120x bone / inch, and the adhesive composition of Table 2. Next, the fabric was peeled off to form a microcell of polyurethane resin, and the results are shown in Table 5.

TABLE 1 Polyurethane Resin Composition

TABLE 2 Composite Adhesive Composition

Comparative Example 1

A cotton fabric having a warp density of 120 ol / inch and a weft density of 60 ol / inch is passed through an anti-precipitation bath in which water and DMF are mixed 6: 4 and squeezed at a pressure of ⁴ Kg / cm ² .

The over was coated at a speed of 5 m / min using a coater.

At this time, the distance from the fabric surface was set to 500μm and the resin composition was used in Table 1.

After solidifying for 5 minutes in a coagulation bath at room temperature, water was washed for 10 minutes in a 60 ° C water bath and dried for 5 minutes with a hot air of 160 ° C.

Example 2

As in Example 1, but foamed bubble paper was used 36 gauge polyester tricoat paper.

Example 3

It was processed under the same conditions as in Example 1, but the surface was polished with sandpaper 180 times after peeling the forge.

Example 4

The process was carried out under the same conditions as in Example 2, but the embossed process was performed after peeling the forge.

Comparative Example 2

All conditions were treated under the same conditions as in Comparative Example 1, but a resin composition was prepared using the wet coating aid of Table 3.

TABLE 3 Polyurethane composition

Comparative Example 3

All conditions were treated under the same conditions as in Comparative Example 1, but were prepared using the wet coating aid of Table 4.

TABLE 4 Polyurethane composition

The physical properties of the synthetic leathers prepared in Examples 1 to 4 and Comparative Examples 1 to 3 are shown in Table 5.

TABLE 5

* Water vapor permeability measuring method = according to JIS Z 0208 method.

* Resilience, touch, and color are based on the sensory test.

Claims (2)

Polyurethane resin composition is produced by forming a polyurethane resin foam layer by a wet coating method on the paper, and then combining the bubble paper and the polyurethane resin foam layer with an adhesive layer and then peeling off the paper. A method for producing synthetic leather, characterized in that the forge is treated with an aqueous 10% to 30% DMF solution before wet coating. The method of producing synthetic leather according to claim 1, wherein the polyurethane resin composition contains 5 to 20 wt% of a cellulose filler.