The method of tanning leather

 

(57) Abstract:

The invention: the pickled hide after preliminary chrome tanning tan composition containing, in wt.%: chrome tanning agent 23 - 35, neutralizing means 30 and 40, the waste product of adipic acid 3 - 33, polyethylenepolyamines sodium 2 - 16, sodium lignosulphonate 2 - 16. Tanning carried out initially at a temperature of 20 - 25 C and a flow rate of 1.0 to 1.5% by weight of the hide within 1 to 2 h, and then at a temperature of 30 - 35C and a flow rate of 2.0 to 3.5 percent by weight of the hide for 4 - 6 hours 1 table.

The invention relates to methods tanned using chromium compounds and can be used in making leather for Shoe uppers.

There is a method of tanning leather, including a preliminary plating of the hide for 1 h chrome tanning agent basicity of 33% with Cr content2O326% at a flow rate of 3-4% by weight of the hide, and the final tanning for 7-8 h at 40-45aboutA composition containing, in wt.%: chrome tanning agent 21-60, neutralizing means 6-13, aromatic di - and tricarboxylic acids WITH8-C136,7-16.3 and their salts 17,8-61,5. The flow rate of 5-6% by weight of the hide [1].

A prototype of the proposed solution is a basicity of 33% with Cr content2O326% at a flow rate of 3-4% by weight of the pickling and tanning for 7-8 h at 40-45aboutA composition containing, in wt.%: chrome tanning agent 29-55, neutralizing means 1,5-23,0, aliphatic dicarboxylic acid WITH4-C612-22 and/or their salts 22,0-69,5. The flow rate of 6-7% by weight of the hide, [2].

A disadvantage of known methods is that they do not allow to increase the output of pelt. In addition, the content of Cr2O3in the waste liquid is 0.1-0.7 g/l, which pollute the waste water tanneries chromium compounds.

The purpose of the invention is to increase the output of pelt and reduction of pollution of wastewater compounds of chromium.

For this purpose, the method of tanning leather, including a preliminary plating and tanning composition containing chromium tanning agent, neutralizing means and aliphatic dicarboxylic acid WITH4-C6in the composition additionally impose polyethylenepolyamines sodium and sodium lignosulphonate, as well as aliphatic dicarboxylic acids used waste product of adipic acid in the following ratio, wt.%: Chrome tanning agent 23-35 Neutralizing means 30-40 Waste production adipine the e stage: the first stage at a temperature of 20-25aboutC and a flow rate of 1.0 to 1.5% by weight of the hide, and the second stage at a temperature of 30-35aboutC and a flow rate of 2.0 to 3.5 percent by weight of the hide. The first stage of the tanning is carried out for 1-2 hours, and the second for 4-6 hours

A distinctive feature of the proposed method is that the final tanning in two stages, with the aforementioned modes, as well as the introduction of polyethyleneglycolate sodium and sodium lignosulphonate with filling and plasticizing action in the presence of neutralizing means and dicarboxylic acids, allows the composition fuller and deeper understanding of the structure of the dermis and evenly distributed in layers that aligns properties of skin topography plots and increases their output area.

In addition, chrome tanning agent forms stable complexes with the components of the mixture, creating chemically active compounds that interact with the functional groups of the protein and form additional cross-links. This leads to the fact that chrome tanning agent is almost completely processed, which reduces the pollution of waste water by chromium compounds.

Waste adipic acid production (TU 113-03-20-70-828 the tion.

Polyethylenepolyamines sodium (TU 6-36-0204229-625-90) and sodium lignosulphonate (OST 13-183-83) currently used in the construction of buildings as concrete admixtures.

The introduction of the neutralizing means less than 30% and waste production adipic acid less than 3% does not allow you to create the optimal pH for complexation of chromium ions with organic components of the composition in the process of tanning, which reduces viviremos chrome tanning agent skin. With the introduction of neutralizing means more than 40% deterioration in the quality of the skin and reduction of output by area, due to the fact that chrome tanning agent is deposited in the surface layers of the skin. Introduction waste adipic acid production more than 33% also leads to deterioration of the quality of the skins because of the high acidity of the composition. Introduction polyethyleneglycolate sodium lignosulphonate sodium less than 2% of each is not possible to increase the output of pelt, in addition reduces the number formed with a chrome tanning agent complexes that affects its development.

The introduction of these substances more than 16% of each is impractical because of the further increase of the output of pelt and otrabotka.net 20 and 30aboutS, respectively, and less than 1 and 4 h reduces the degree of absorption of chromium by semi-finished products and improving them over 25 and 35aboutWith over 2 and 6 h impractical, so as to further enhance the effect of absorption does not occur.

Introduction tanning composition in the final tanning less than 1.0% in the first stage and less than 2% on the second leads to the decrease of the output of pelt, and the increase in consumption of more than 1.5% and 3.5% respectively impractical because of the further increase of the output of pelt does not occur and increases the content of Cr2O3in the wastewater.

The technology of the method is as follows.

The hide, obtained by standard methods from raw cattle, after pickling homeroot in the same tub at the expense of chrome tanning agent (the basicity of 38-40% with Cr content2O326%) of 0.8-1.1% of the weight of the hide during 1-1,5 h at 20-25aboutC. Then, in the same tub impose a powder composition containing, by weight. % : chrome tanning agent 23-35, neutralizing means 30-40, waste production adipic acid 3-33, polyethylenepolyamines sodium 2-16 and sodium lignosulphonate 2-16. All ingredients pre-mixed sequentially in specifically what the temperature 20-25aboutWith the processing time is 1-2 hours Then spend the second stage of tanning the same part in its consumption of 2.0 to 3.5% by weight of the hide, and a temperature of 30-35aboutC for 4-6 hours All further processes and operations carried out by standard methods.

P R I m e R 1. The hide, obtained by standard methods from raw materials byczyna after pickling was chromasomal at a flow rate of chrome tanning agent (the basicity of 38-40% with Cr content2O326%) of 1.1% by weight of the hide for 1 h Then conducted the first stage of tanning, which in the same bath was added the following composition, wt.%: chrome tanning agent basicity 38-40% with Cr content2O326% 23, dolomite 3,6, magnesium oxide 4, the waste product of adipic acid 33, polyethylenepolyamines sodium 2, the sodium lignosulphonate 2. The flow rate of 1,5%, temperature 20aboutWith the duration of treatment 2 hours Then carried out the second stage of tanning, which was added to the composition at the rate of 2% by weight of the hide, the temperature of the 35aboutAnd the processing continued 6 Further including the processes and operations performed by standard methods.

P R I m m e R 2. The hide, obtained by standard methods from raw materials rawhide heavy, was treated as in example 1, but the first stage of tanning was carried out following insolvent sodium 9 and sodium lignosulphonate 9. The flow rate of 1.25 percent by weight of the hide, the temperature of the 23aboutWith, the processing time of 1.5 h, and the second stage of tanning was carried out at the expense of the same composition of 2.8% by weight of the hide, when the temperature of the 33aboutC for 5 h

P R I m e R 3. The hide, obtained by standard methods from raw materials of the bull, was treated as in example 1, but the first stage of the tanning conducted in the following composition, wt.%: chrome tanning agent 35, dolomite 29, sodium bicarbonate 1, the waste product of adipic acid 3, polyethylenepolyamines sodium 16 and sodium lignosulphonate 16. The flow rate of 1.0% of the weight of the hide, temperature 25aboutWith, the processing time for the 1 o'clock of the Second stage of tanning was carried out at the expense of the same composition of 3.5% by weight of the hide and temperature 30aboutC for 4 h

P R I m e R 4. The hide, obtained by standard methods from raw materials rawhide average, were processed as in example 1, but the first stage of the tanning produced the following composition, wt. % : chrome tanning agent 22, dolomite 37, magnesium oxide 4, the waste product of adipic acid 34, polyethylenepolyamines sodium 1.5 and sodium lignosulphonate of 1.5, at a flow rate of 0.8 percent by weight of the hide, and the temperature of the 26aboutC for 0.8 h, and the second stage of the tanning ASU is. the ollier, obtained by standard methods from raw materials bull, was treated as in example 1, but the first stage of the tanning produced the following composition, wt.%: chrome tanning agent 36, 26 dolomite, magnesium oxide 3, the waste adipic acid production 2, polyethylenepolyamines sodium 16.5 and sodium lignosulphonate 16,5, at a flow rate of 1.7 percent by weight of the hide, and the temperature of the 18aboutWith over 2.2 hours, and the second stage of tanning was carried out at a flow rate of 1.8% and a temperature of 37aboutWith over 6,3 h

In all the examples were obtained finished leather, which met all the requirements of GOST 939-88 and had the figures shown in the table.

The use of the proposed method will allow to increase the output of pelt 1.0-1.5% and significantly reduce the pollution of waste water tanneries of chromium compounds.

The METHOD of TANNING LEATHER, including preliminary chrome tanning and tanning composition containing chromium tanning agent, neutralizing means and aliphatic dicarboxylic acids (C4- C6, characterized in that the composition additionally impose polyethylenepolyamines sodium and sodium lignosulphonate, as well as aliphatic dicarbonate>Chrome tanning agent - 23 - 35

Neutralizing means - 30 - 40

The waste product of adipic acid - 3 - 33

Polyethylenepolyamines sodium - 2 - 16

Sodium lignosulphonate - 2 - 16

and tanning is carried out in two stages, the first stage at 20 - 25oC and a flow rate of 1.0 to 1.5% by weight of the hide within 1 to 2 h, and the second stage at 30 - 35oC and a flow rate of 2 to 3.5% by weight of the hide for 4 - 6 hours

 

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