SU931745A1 - Composition for tanning sheepskins - Google Patents

Description

(54) COMPOSITION FOR VOLVO BOTTOMING

one

The invention relates to light industry and can be used in fur production for dressing ov-. rank

A composition for tanning sheepskins, including negative basicity chromium tanning agent, acid and table salt 1, is known.

However, the use of this composition does not allow to obtain a high yield of the semi-finished product per square meter.

In addition, tanning with the indicated composition implies the need for pickling, as well as the neutralization process.

At present: its time the most promising direction of sheepskin processing is the creation of a self-regulating tanning process, which allows the process to be carried out quickly and efficiently without the introduction of neutralizing agents. Such treatment allows reducing labor costs, consumption of chemical materials, reducing losses of tanning agents, reducing the degree of sunset hair by reducing the processing time of sheepskins in rotating equipment.

The closest to the proposed technical, essence and the achieved result is the composition for tanning sheepskins, including low-base chrome tanning agent, table salt and water 2. This composition is used to treat non-nickel skins without introducing soda during the tanning process.

However, its use for sheepskin tanning is possible only with the obligatory carrying out of preliminary skinning in an acidic medium without the addition of table salt, which causes leather leaking.

The disadvantages of this composition include the production of flesh skins with a low output over the area and the considerable duration of the tanning process.

The purpose of the invention is to increase the yield by area of finished products and to intensify the process.

Claims (3)

This goal is achieved by the fact that the composition, including low-basic chromic tanning agent, sodium chloride and water, additionally contains acetic acid in the following ratio of components, g / l: Chromic tanning agent (in terms of chromium oxide) 3.0-3.5 Cooked salt 40 -50 Acetic acid (100%) 3.5-4.0 Vodado 1 l At the same time, this composition contains a chrome tanning agent with a basicity of 12-15%. Tanning with chromium salts with a basicity of 12–15% in the presence of acetic acid makes it possible to completely exclude the pickling or sour soaking process from sheepskins and achieve a quick and high-quality process without the addition of neutralizing agents. Such a process is self-regulating, and the cast welding temperature required by GOST 1821-75 is achieved within hours. The suggested concentrations of chromium oxide and acetic acid, as well as the basicity of chromium sulfate, are optimal values, which is confirmed by experimental data. With an increase in basicity above 15%, the presence of a “blunt” face of the sheepskin skin is possible; with a decrease in basicity below 12%, the tanning process slows down dramatically and its quality decreases. The concentration of acetic acid of 3.5-4.0 g / l ensures a smooth change in the degree of masking of the tanning agent, which creates the possibility of a uniform tanning process, increases the uniformity of the distribution of tanning agents in leather. With increasing or decreasing acid concentration, this effect is not fully achieved. The use of chromium oxide concentration of 3.0-3.5 g / l provides the required degree of oblivion of the leather. Example 1. Sheepskin coat, wet-salted method of preservation is subjected to soaking, fertilization, degreasing of hair and then tanned with a composition comprising, g / l: Chromium sulfate with 12% basicity 3.5 Salt 40.0 Acetic acid3.5 For 4 h at the end of the treatment, the pH of the tanning solution is 3.85. The temperature of leather sealing at the end of tanning is 85-87 ° C. Subsequent processes and operations are carried out according to the Unified Technology of Fur Sheepskin Processing (1973). The yield of sheepskins in finished form is 88%. Example 2. Sheepskin fur coats of sugary canning are subjected to the 1st and 2nd soak, intestinal degreasing, degreasing of hair and then an oak with a solution containing the following composition, g / l: Chromium sulphate with a basicity of 13.5% 3.0 Cooked salt45.0 Acetic acid 4.0 For a period of 5 hours after the treatment is completed, the pH of the tanning solution is 3.94. Leatherworking temperature at the end of tanning is 84-86 ° G. Subsequent processes and operations were carried out according to the Uniform Technology for the treatment of a shallow sheepskin (1973). The yield of sheepskins in finished form is 89%. Example 3. Sheepskin coat of wet-salted canning process is treated similar to that specified in Example 1 before the tanning process. Tanning is carried out with a composition containing, g / l: Chromium sulphate with a basicity of 15% 3.25. Cooked salt 50.0 Acetic acid 3.75 Within 4 hours after processing the pH of the tanning solution is 3.90. The temperature of leather sealing at the end of tanning is 85-86 ° C. Subsequent processes and operations are carried out according to the Uniform Technology for the treatment of the delicate sheepskin (1973). The yield of sheepskins in finished form is 89%. In all examples, the liquid coefficient has a value of 5.0, the initial temperature of the tanning solution is 38-40 ° C. Control samples are subjected to acid-freezing after degreasing at a sulfuric acid concentration of 0.5 g / l for 4-6 hours, and then dubbed with a known composition for 8 hours. The welding temperature at the end of tanning is 77-79 ° C. Output square sheepskins 86%. Similar results were obtained with tanning with chromium sulfate with a basicity of 0% for 10 hours. Comparison of samples of sheepskins treated by the proposed method and known shows that test samples are more complete and softer by sensory evaluation. Histological analysis shows a better sustainability and a more even distribution of the tanner in the structure of the leather fabric in the test samples. The yield of sheepskins is increased by 2-3%, the duration of treatment is reduced by 5-7 hours by eliminating acid soaking and shortening the tanning time. Claim 1. Composition for sheepskins tanning, comprising a low-base chromic tanning agent, salt and water, characterized in that, in order to increase the yield over an area of 931745 di finished products and intensification2. The composition according to claim 1, wherein process, it additionally contains the c-what it contains chromic tanning agent with arsenic acid in the following ratio of 12-15%. components, g / l: Sources of information. Chrome tanning agent (in re-taken into account during the examination account for chromium oxide) 3.0-3.55 1. USSR author's certificate Cooking salt 40-50№65975, cl. From 14 to 3/06, 1942. Acetic acid2. USSR author's certificate (100 ° / о-на) 3.5-4.0№ 66704, cl. C 14 C 3/06, 194b (protoVodo to 1 ltyp).