The way we produce leather

 

(57) Abstract:

The method can be used for the production of leather for various purposes. Semi-finished hides and skins of bovine doublenaut chrome tanning agent. Neutralize with liquid coefficient of 0,4 - 0,8 simultaneously with the processing of ethoxylated fat in the amount of 1.5 to 2.5% by weight of semi-finished product, counting for 100% fat. Treat the product of saponification aqueous dispersion of polyacrylonitrile with the content of carboxyl groups of 10 to 14% by weight of polymer in the amount of 3 - 4% by weight of semi-finished product, counting on a dry residue. Then paint, it is greased and doublenaut organic tanning agent. This method allows to improve the quality of skin by improving their mechanical properties. table 1.

The invention relates to leather production, in particular for dyeing and greasing processes, and can be used in making leather for various purposes.

There is a method of generation of leather, including the processing of semi-finished product within 30 to 45 min with a solution of polyacrylamide with a molecular weight (4,5-5,5)106previously neutralized with alkali to pH 7.5 to 8.0, in the amount of 0.7 to 2.0% by weight of semi-finished product, counting on the dry matter, the processing in the course is the processing for 40-60 min greasing emulsion [1].

The disadvantage of this method is that the use as filler polyacrylamide with a very high molecular weight prevents the latter evenly distributed layers of the dermis, resulting in skin with nonuniform thickness and topographic plots properties.

The closest analogue of the proposed technical solution is the way to making skins, including retanning semi-finished chrome tanning agent, neutralization, processing sulfotyrosine fat in the presence of the acrylic copolymer in their consumption by 2-3% by weight of the semifinished product, counting for 100% fat and the dry residue, dyeing with W.to. 0.3 to 0.4 and temperature of 20-25oC, greasing and retanning organic tanning agent. [2]

The disadvantage of this method is that it does not allow the skin with high flow properties.

The technical result of the invention is to improve the quality of skin by increasing their flow properties. This result is achieved in that in the method of manufacture of leathers, including retanning semi-finished chrome tanning agent, neutralization processing greasing emulsion and acrylic copolymer, dying, greasing and double the ri liquid ratio of 0.4 to 0.8, as greasing emulsions using ethoxylated fat in the amount of 1.5 to 2.5% by weight of semi-finished product, counting for 100% fat, and as an acrylic copolymer using the product of the saponification aqueous dispersion of polyacrylonitrile (Acres) with the content of carboxyl groups 10-14% by weight of polymer in the amount of 3-4% by weight of semi-finished product, counting on the dry matter.

A distinctive feature of the proposed method is neutralised at low W.to. in the presence of ethoxylated fat and the use of an acrylic copolymer of Acres with the content of carboxyl groups 10-14% by weight of polymer that provides a deeper and more uniform neutralization throughout the thickness of the semi-finished product, as well as the higher strength properties of the skin due to more uniform and intense binding and distribution of the copolymer according to the skin layers by reaction of carboxyl groups with free chromium atoms contained in the material is chrome tanned.

The technology of filling material Acris (saponified polyacrylonitrile) is as follows:

In the reactor 0.7 m3equipped with a bright stirrer and reflux condenser, download 400 l actor load 250 kg aqueous dispersion of polyacrylonitrile. The temperature in the reactor increased to 955oC and the process of saponification is carried out for 3.0 to 3.5 h to the content of carboxyl groups in the final product 10-14% by weight of the polymer. After cooling to 40oC the finished product is unloaded.

Neutralised with W.to. less than 0.4 leads to the formation of whiskers on the front surface of the skin due to intense friction of her on the wall of the drum. Neutralised with W.to. more than 0.8 slows down the process of neutralization.

Introduction ethoxylated fat less than 1.5% by weight of semi-finished product, counting for 100% fat, and acrylic copolymer of Acres with the content of carboxyl groups is less than 10% by weight of polymer in the amount of less than 3% of the mass of the semi-finished product, counting on the dry matter, do not provide the supple leather with high strength properties. Introduction ethoxylated fat more than 2.5% by weight of semi-finished and acrylic copolymer of Acres with the content of carboxyl groups of more than 14% by weight of polymer in the amount of more than 4% by weight of semi-finished product is impractical because of the further increase of the strength properties does not occur.

The method is as follows.

The drum load of prefabrica rinsing for 15-20 minutes Then the drum fill in water temperature 30-35oC calculation of W. K. 0,4-0,8, dispense a neutralizing agent in an amount of 2.0 to 2.5% by weight of intermediate product together with 1.5 to 2.5% by weight of semi-finished ethoxylated fat, 30-45 min in the dryer injected acrylic copolymer Acres in the amount of 3-4% by weight of semi-finished product, counting on a solid residue, and the treatment continued for 1.0 to 1.5 hours after the neutralization control indicator bromo-kresolver green to end-to-end pokras. Then make a short rinse. The subsequent processes of dyeing, fatliquoring and dublirovaniya organic tanning agent are carried out by a known method at a flow rate of dyes 2-3% by weight of semi-finished and doublelayer materials 2-4% by weight of proletariata, considering tanney and tanning.

Example 1. The semi-finished product obtained by standard methods from the skins of cattle, after retanning chrome tanning agent is subjected to washing at a temperature of 30oC and W.to. 2.0 V for 20 min, neutralization with sodium bicarbonate in the amount of 2% by weight of semi-finished product with W.to. 0.4 and temperature 30oC in the presence of ethoxylated fat CBT MEMBER in the amount of 1.5% by weight of the semifinished product, counting for 10% fat. After 45 min in the balance, and the treatment continued for 1.0 hours Further processes of dyeing, fatliquoring and retanning organic tanning agent are carried out by standard methods.

Example 2. The semi-finished product obtained by standard methods from the skins of cattle, after retanning chrome tanning agent is treated as in example 1, but the neutralization is carried out at W.to. 0,6, ethoxylated fat swift 1 enter in the amount of 2.0% by weight of semi-finished product, counting for 100% fat, and acrylic copolymer Acres to 3.5% by weight of semi-finished product, counting on the dry matter.

Example 3. The semi-finished product obtained by standard methods from the skins of cattle, after retanning chrome tanning agent is treated as in example 1, but the neutralization is carried out at W.to. 0,8, ethoxylated fat swift L enter in the amount of 2.5% by weight of semi-finished product, counting for 100% fat, and acrylic copolymer Acres to 4.0% by weight of semi-finished product, counting on the dry matter.

Example 4. The semi-finished product obtained by standard methods from the skins of cattle, after dublirovaniya chrome tanning agent, is treated as in example 1, but the neutralization is carried out at W.to. 0,3, ethoxylated fat CBT CL enter in the amount of 1.3% by weight of none who CLASS="ptx2">

Example 5. The semi-finished product obtained by standard methods from the skins of cattle, after retanning chrome tanning agent is treated as in example 1, but the neutralization is carried out at W.to. 0,9, ethoxylated fat swift 1 enter in the amount of 2.7% by weight of semi-finished product, counting for 100% fat, and acrylic copolymer Acres of 4.2% by weight of semi-finished product, counting on the dry matter.

Qualitative indicators of finished leather, obtained by the proposed method and the method prototype, presented in the table.

Using the proposed method allows to obtain uniformly filled in all topographical areas for the uppers with high strength properties.

The method of manufacture of leathers, including retanning semi-finished chrome tanning agent, neutralization, processing greasing emulsion and acrylic copolymer, dying, greasing and retanning organic tanning agent, characterized in that the neutralization and processing of greasing emulsion takes place simultaneously with volume ratio of 0.4 to 0.8, as greasing emulsions used ethoxylated fat in the amount of 1.5 to 2.5% by weight of semi-finished product, counting for 100% fat, but as acrylic p 10 - 14% by weight of polymer, in the amount of 3 - 4% by weight of semi-finished product, counting on a dry residue.

 

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FIELD: leather industry.

SUBSTANCE: semifinished product is degreased, neutralized, dyed, and lubricated. Dyeing is performed in two washing-interrupted steps with anionic black dye consumed in amount 0.5-0.6% of the weight of semifinished product in each dyeing step. Lubrication is followed by retannage with chrome tanner in amount 0.6-1.0% of the weight of semifinished product (calculated for chromium oxide) and treatment with 0.8-1.0% of spindle oil.

EFFECT: achieved deep black color and high performance characteristics.

1 tbl, 5 ex

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