CS214055B1 - Method of production of tanned leather - Google Patents

Abstract

The invention is dependent on the invention according to PV 3505-80, the essence of which is that the penetration of tannins into the leather is adjusted and accelerated by adding cationic substances to the leather before tanning with tannins. In this dependent invention, in order to better utilize the used tannins and improve the quality of the leather, a condensate of naphthalene mono-, dia trisulfonic acids is added to the tanning baths. The invention can be used in all tanning plants.

Description

The object of the invention is to improve the method of producing tri-compound leather in a shortened manner.

The essence of the shortened method is the use of cationic substances, which affect the penetration of concentrated tanning substances, especially natural or synthetic tannins, into the leather. The leather is treated with the above-mentioned cationic substances before the actual tanning process. In order to improve the physical and chemical properties of the resulting leather and further improve the usability of the tannins, a condensate of naphthalene mono-, di- and trisulfonic acids is added to the tanning baths. This method allows the leather to be processed without the operation of pickling and pre-tanning. According to the basic patent, it achieves accelerated tanning of the leather.

Improved utilization of the supplied tannins, further shortening of the tanning time and improvement of the properties of the tanned leathers is achieved by using naphthalene mono-, di- and trisulfonic acids, their salts, condensates, or mixtures of raw materials. These acids are added before, during or after the addition of tannins in an amount of 0.1-8 wt. %, calculated on the weight of the choline. If mineral agents are used simultaneously in this process, very good utilization of Cr ₂ 0 ₃ occurs when using the above-mentioned acids.

All types of leather, including pigskin, can be tanned in this way. The values for the tannin and C**2®3 content ⁱⁿ the bath are given at the ^end of the examples.

The process according to the invention is illustrated by the following exemplary embodiments, which represent only a few of the many possible variants.

Example 1.

Combination-tanned pigskin

All data are calculated on the basis of the weight of the tree.

The clearing is prepared according to normal operating conditions.

Laundry - by water flow 30 - 35 °C in tanning barrel Degreasing - 200 wt. X water 30 - 35 °C 0.3 wt. X Oubaryl 30 minutes movement until morning, in peace in the bath * Laundry - with water flow 35 - 38 °C 10 minutes movement Descaling - 200 wt. X with water 35 - 38 °C 10 minutes movement 2 wt. X ammonium sulfate 30 minutes movement 0.04 ha. X aoridlo -Protoase B 72 0.5 ha. X ammonium sulfate 180 minutes movement pH 0, 0-6, .5 Laundry - water flow 28 - 30 °C 15 minutes movement Tanning - 50 wt. X water 28 - 30 °C 180 minutes movement

wt. % cationic dispersant (Syntamin KX) overnight at rest the bath is heated to 30 °C wt. X exchangeable tannin (Kortan M) wt. X basic chromium sulfate (26 wt. X CrgO^) (Chromzaz) wt. X Kortan 5 4 hours , - boil-resistant wt. X PK 20 lubricant 2 hours heat to 35 - 40 °C

214,055

0.5 ha. % NaHC0 ₃ resulting pH 4.0

Further treatment as with normally tanned leather.

The chromium content in the waste bath is in the range of 0.1 - 0.2 g Cr ₂ 0g/l and the tannin content is a maximum of 1 wt. X.

Example 2.

Beef tenderloin

It uses a clearing prepared according to normal operating practices.

Washing: through water flow 30 - 35 °C movement 15 min Descaling: 80 wt. % water 38 °C 3 wt. X ammonium sulfate 30 minutes 0.04 wt. % pickling agent (Protease B 72) 30 minutes 0.04 wt. % HCOOH 0.04 wt. X sulfuric acid 60 minutes Washing: through water flow 25 - 30 °C movement 15 min Tanning:. 50 wt. X water 38 - 40 °C

wt. X cationic dispersant movement 180 min (Syntamin KX) overnight at rest

2nd day - 24 wt. % fresh weight of grade (mixture of 70 wt. % Kortan M 30 wt. % Quebracho) added 3 times after 60 min.

wt. % Kortan R movement 6 hrs. overnight at rest

The use of the invention will contribute to the acceleration of the tanning process and, above all, the utilization of tannins and mineral agents will increase while improving the quality of leather. At the same time, the pollution of wastewater will be reduced and thus the costs of its treatment will be reduced. It can be used in all tanneries of the ZAZ, where it was tested in operation, as well as in other tanneries of the Czechoslovak Socialist Republic.

Claims (1)

SUBJECT OF THE INVENTION A process for the production of tanned leather from decalcified or possibly burned wort, which is not acidified but only acidified and further processed in a dynamic process in a bath consisting of 20 to 200 wt. % water and 0.1 to 5 wt. X cationic substances, such as e.g. alkyl polypropylenepolyamines, wherein the number of amino groups is one larger than the propylene moieties, which is 1-5 and the alkyl group contains ^{Al C} 24 ^{8 NA8} s ^price ý ^{mi 1} unsaturated bonds and a quaternized organic and inorganic acids s to Cg, or quaternized salts of natural oils, or aqueous dispersions of epoxies, followed by tanning according to AO 214 054, characterized in that 0.1 g of naphthalenonone, dl- and trieulfonic acid condensate is added to the tanning baths in an amount of 0.1 up to 0.8 wt. X, calculated on holin weight.