KR790001863B1 - Manufacturing method of synthetic leather - Google Patents

Abstract

Sythetic leather impregnating nonwoven fabric with waste polyurethane fiber (spandex) was manufd. by wet process. Thus, nonwoven fabric was impregnated by passing through waste polyurethane fiber adhesive soln. bath, after passing through 20% aq. tin chloride soln, 20% aq. zinc chloride soln, and 45OC clean water bath. One side of obtained non-woven fabric was knifecoated at 45OC and passed through 20% aq. tin chloride soln. at 45OC to form a foam layer, and later knifecoated by the adhesive soln. to give synthetic leather.

Description

Manufacturing method of synthetic leather by wet method

1 is a first process diagram of the present invention.

2 is a first process diagram of the method of the present invention.

3 is a structural cross-sectional view of the synthetic leather according to the method of the present invention.

The present invention relates to a method for producing synthetic leather by the wet method.

More specifically, the present invention relates to a method for producing synthetic leather by a wet method using a waste polyurethane fiber (spantex) as a main raw material.

Conventionally, the dry method which apply | coats or coats polymers, such as polyurethane, to fiber base materials, such as a nonwoven fabric, and hardens by hot air drying is common.

However, according to this dry method, the coating or coating is not uniform, and the final product has a defect in that the coated surface is cracked or peeled off during use due to poor flexural strength, tactile adhesion, and the like.

It is therefore an object of the present invention to provide a method for producing a new synthetic leather that can completely overcome these shortcomings and be comparable to natural leather.

This purpose is to pass through a plurality of rollers through an adhesive liquid tank mainly composed of polyurethane waste fibers on a known nonwoven fabric through a plurality of rollers, 20% aqueous solution of tin chloride, 20% aqueous solution of zinc chloride, and 45 ° C. The first coating process to pass through the water purification tank and the second coating to pass the 20% aqueous solution tank of tin chloride by knife coating the above-mentioned polyurethane waste fiber adhesive solution on the surface of the primary coating again at 45 ° C. It is achieved by the manufacturing method of synthetic leather by the wet method which consists of a process.

The adhesive liquid of the polyurethane waste fiber base material according to the present invention is a polyurethane resin is appropriately reinforced with a polyurethane resin, and a plasticizer, a curing aid, a foaming agent, a predetermined pigment, a wetting agent and the like are dissolved in a suitable organic solvent.

DBP or DOP is used as a plasticizer, and triphenylethane diisocyanate (TDI) is used as a foaming agent.

Wetting agents are intended to give more flexibility to the surface of the product and can be easily obtained from silicone oil and kerosene.

As a solvent, methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), and acetone (AC) can be used individually or in mixture.

In addition, an appropriate amount of epoxy resin and rubber may be used as an adhesive and an elastic aid.

If a typical example of the formulation of the adhesive according to the present invention is introduced as follows.

ingredient

Compounding ratio (% by weight)

Polyurethane Waste Fiber ‥‥‥‥‥‥‥‥‥‥‥‥

Polyurethane Resin ‥‥‥‥‥‥‥‥‥‥‥‥‥ 50

DBP ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 0.5

MIBK ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 30

MEK ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 40

AC ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 15

TDI ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 10

DMF ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 50

Buna-S ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 20

Silicone oil ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 0.4

Kerosene ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 0.1

Pigment ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 0.5

(However, TDI may not be added depending on the treatment process.)

The reason why the above-mentioned adhesive liquid is applied to the nonwoven fabric and then passed through an aqueous solution tank of tin chloride and zinc chloride is an operation for causing the polyurethane coating layer to uniformly occur.

The polyurethane waste fiber can be effective by mixing a small amount of PVC.

When the present invention is described in detail according to the accompanying drawings as follows.

1 is a schematic illustration of a primary process according to the method of the invention.

A and B each add two sets of the above-described mixing solution tanks, and the number thereof can be increased or decreased appropriately.

Group B can contain an adhesive liquid tank of the same component as Group A.

C. D is a 20% aqueous bath of tin chloride and zinc chloride, respectively.

E is a water purification tank maintained at 45 ° C., and the polyurethane is uniformly cured while passing through the water purification tank.

The nonwoven fabric wound on the winding roller 1 is introduced in order to each of the above-mentioned A-E via a plurality of guide rollers and a compression roller.

The nonwoven fabric which has passed through the adhesive liquid tank is pressed by a pressing roller.

Groups C and D may randomly change their order.

Polyurethane coating layer on the nonwoven fabric which passed the tank E can be dried by the drying roller provided in the drying part F, and can be wound up by the winding roller 2. As shown in FIG.

The nonwoven fabric impregnated with the polyurethane which has passed through the process according to this first drawing (primary roting step) is in a foamed state.

Therefore, by using a needle or punched nonwoven fabric in advance, the ventilation is very excellent.

However, the polyurethane impregnated nonwoven fabric treated by this primary process forms an application layer by the same process as the example shown in FIG.

The non-woven fabric impregnated with the polyurethane wound on the winding roller 2 in FIG. 1 is supplied with the above-mentioned adhesive from the hopper 4 in the primary knife coating bath G maintained at 45 ° C., and the knife nose in the roller 3. Forming a foam layer and immediately passing through a 20% tin chloride bath H of 45 ° C. while giving a constant tension by manipulating the position of the movable roller, and then drying it to around 120 ° C. in the secondary drying chamber I, followed by a secondary knife. A wet thin film layer is formed by knife coating the adhesive (not including foaming agent) fed to the coating tank J and fed from the hopper 5 by the roller 6.

After this secondary coating tank, a liquid tank such as H may be provided.

The above-mentioned liquid bath H contains an aqueous solution in which 20% of tin chloride is dissolved, thereby achieving the same purpose as in the first step.

According to the wet method of the present invention as described above, the polyurethane immersed in the nonwoven fabric increases the fire resistance and adhesion by the action of tin chloride and zinc chloride before hardening occurs, and the surface and the internal hardening occur uniformly. The gloss becomes good.

As shown in the cross section of the synthetic leather according to the present invention schematically shown in FIG. 3, the coating layer by the primary coating process is a wet foam layer on the nonwoven fabric and the coating layer by the secondary coating process is the upper portion thereof. On wet thin film layer.

It is preferable that the thickness of the wet foam layer and the wet thin film layer is 1: 1 to 2: 1.

The enamel protective layer can also be formed on a wet thin film layer by a well-known method.

As described above, the synthetic leather according to the method of the present invention has a foam layer of the same quality as the upper layer therein, so that the flexibility is good and the adhesive strength is strong, so that the phenomenon of peeling during processing or use does not occur, and the fire resistant treatment is a high quality leather. to be.

Hereinafter will be described as an embodiment of the present invention.

Example 1

Adhesives 1 and 2 were prepared in the following compounding amounts.

Adhesive 1: Component Compounding Amount (g)

Polyurethane Waste Fiber 100

PVC (# 427) 10

Polyurethane Resin (5,707) 50

DBP (or DOP) (plasticizer) 0.8

MIBK (Solvent) 135

TDI (foaming agent) 10

Buna-S 20

Silicone Oil (KF-96) 0.4

Epoxy Resin 0.5

Korom sulfur (pigment) 0.05

336.75

Adhesive 2: 331.75 of the same ingredient as Adhesive 1 was added except that foaming agent (TDI) was omitted.

Example 2

The adhesive 2 obtained in Example 1 was introduced into A, B of FIG. 1 and the second knife coating bath J of FIG. 2, and the adhesive 1 was introduced into the hopper 4 of FIG. 2 to store the nonwoven fabric in the storage winding roller 1 Consistent work was done by supplying

When passing through the impregnating tanks A and B, the adhesive liquid is sufficiently removed by the pressing roller, and the nonwoven fabric passed through the tin chloride bath, zinc chloride bath, and water purification tank is knives coated from the primary knife coating tank G to the rollers (3) by the adhesive 1. After passing through a water bath (containing 20% tin chloride) immediately after drying, it was dried at 120 ° C. and coated again with adhesive 2 in secondary knife coating.

The water tank passing process after the 2nd coating was not performed. The physical properties of the product are as follows.

Tensile Strength: 12-13kg / ㎠

Tear Strength: 18.5-19.0kg / ㎠

Modulus of elasticity: 10-15%

Oil absorption rate: 0.1% or less

Hygroscopic heat: less than 0.3%

Heat Deflection Temperature: 1, 200 ℃ or higher

Chemical resistance: excellent.

Claims (1)

A known nonwoven fabric is passed through a plurality of rollers at least two times through an adhesive liquid tank mainly composed of polyurethane waste fibers, and then passed through a 20% aqueous solution tank of tin chloride, a 20% aqueous solution tank of zinc chloride, and a 45 ° C water purification tank in this order. The first step of obtaining a non-woven fabric impregnated with the adhesive, and first adhesive coating the adhesive on one surface of the non-adhesive impregnated nonwoven fabric again at 45 ℃ to pass through a 45% aqueous solution of 20% tin chloride to form a foam layer, A method for producing synthetic leather by the wet method, characterized in that it consists of a combination of a secondary process of coating the adhesive (without foaming agent) on the foaming layer.

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