SU1288204A1 - Method of tawing leather - Google Patents

Abstract

The invention relates to a method for producing leather and allows for increasing the intensity of coloring of leather and its grade. The semi-finished product after planing is dyed in the presence of an electrolyte-resistant fat emulsion in an amount of 1.0-1.5% by weight of the cut leather. Then, simultaneous retanning and neutralization with the consumption of synthetic tanning agents 7., 0-2.5%, counting on oak - 1cc, based on the mass of sliced leather, greasing and treatment with organic acid is carried out. 1 tab. i

Description

The invention relates to the chemical treatment of leather and can be used in the production of soft types of mineral tanning leather.

The purpose of the invention is to increase the intensity of skin coloring and increase their grade.

The essence of the invention is that according to the method of producing leather, including neutralization, retanning, dyeing, fattening and treatment with organic acid, before neutralization, dyeing in the presence of a fat emulsion resistant to electrolytes is 1.0-1.5% of the masses of skinned leather, and the duplication is carried out simultaneously with the neutralization at a flow rate of synthetic tanning of 2.0-2.5%, considering duplicate, of the mass of planed leather.

According to the proposed method, the dyeing is carried out before neutralization, which allows the dyes to bind more tightly to the leather fabric and increases the intensity of coloring.

Before neutralization after chrome tanning, the skin has a pH of 3.8-4.2, which contributes to better sorption of the dye and its binding to the fibers. When dyeing a fat emulsion, SUSTAINABLE to electrolytes ensures uniform color and eliminates skin patches. In addition, the use of fat emulsion contributes to the loosening of the microstructure of the fibers of the skin and thereby increase the permeability of the fibers for the diffusion of dye particles. With such a system of dyeing, the dye gradually passes first into the fat emulsion, and then into the fiber, which contributes to a deeper penetration of the dye.

The process technology is as follows.

The semifinished product obtained according to a known method, after planing, is painted together in one drum with a liquid coefficient (gf) of 1.0-1.2 and at 50-55 ° C at a dye consumption of 1.5-2.0%. An electrolyte-resistant emulsion in an amount of 1.0-1.5%, counting on fattening agents, is introduced into the drum either simultaneously with the dye or 10-15 minutes after dye injection. Dyeing lead for 20-30 minutes

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Then, a synthetic tanning agent in the amount of 2.0-2.5% is loaded into the drum, counting on the tanning ones, by weight of the cut leather and 0.5-0.7% of sodium bicarbonate. After 20 minutes, give the second portion of sodium bicarbonate. 0.5-0.7% of the mass of the planed leather and rotate for 20 minutes. After the pH of the bath reaches 5.0-5.5, the fat emulsion is washed down into the drum with the consumption of fatty substances of 6.0-8.0%, counting on the fatty substances.

After 45-50 minutes, the treatment with organic acid is carried out at a flow rate of 1.0-1.5% for 15-20 minutes.

The semifinished product is washed and unloaded. Subsequent processes and operations are carried out according to a known method.

Example 1. A semi-finished product from a light goat raw material, produced by a known method, after planing, is washed for 15 minutes at 50 ° C in running water. Then dyeing is performed at a liquid ratio of 1.0; the dye consumption is 1.5% (by weight of planed leather) in the presence of the fat emulsion of the paste VNIIZh - 1.0%, calculated on the fatty. After 20 minutes, Sintan No. 2 is loaded into the same bath in an amount of 2.0% counting for tanning and 0.5% sodium bicarbonate. The treatment is carried out for 20 minutes, then another 0.7% sodium bicarbonate is poured. After 20 minutes, fattening is carried out for 45 minutes at a fat consumption of 6.0%, based on pure fat, as follows, in wt%: sulphurized brew 40; synthetic fat 40; mineral oil 20.

The treatment with acetic acid was carried out for 10 minutes, the consumption of acetic acid was 1.0%. Further processes are carried out according to a known method.

PRI mme R 2. A semi-finished product from a medium-dexterity raw material produced according to a known method is treated as in Example 1, but dyeing is carried out in the presence of Polyx's fat emulsion at a rate of 1.25% by weight of sliced leather, based on , and retanning is carried out simultaneously with neutralization with a synthetic tanning agent of BNS in the amount of 2-3%, counting as tanning.

EXAMPLE 3 A semi-finished product from light raw material produced by a known method is treated as in Example 1, but dyeing is carried out in the presence of fatty emulsin Chloropol — 1.5%, considering fattening, and retanning is carried out simultaneously with the neutralization of synthetic tanning agent NB in the amount of 2.5%, counting on the dubious ones.

As a result of examples -3, ready-made skins are obtained that meet all the requirements and have physical and mechanical properties and grade,

Claims (1)

shown in the table. Invention Formula A method of making leathers, including neutralization, retanning, breaking. Strength at stretching, MPa Stress when the surface layer cracks, MPa Elongation at a voltage of 9.8 MPa,% Grade finished leather,% Adhesion Coating, 098 N / m to dry skin to wet skin Color stability of direct dyes, score greasing and treatment with organic acid, characterized in that, in order to increase the intensity of skin coloring and increase their grade, dyeing the wire before neutralization in the presence of a fat emulsion resistant to electrolytes in an amount of 1.0-1.5% by weight of sliced leather , and retanning is carried out simultaneously with neutralization at a consumption of synthetic tanning agents of 2.0-2.5%, counting on dubbing, of the mass of sliced leather. 34,534,032.4 29,228,427,0 29,528,927,8 84,384,882,2 651629443 215196135