HU192421B - Composition for the unhairing and liming of animal hides - Google Patents

Abstract

The reagent for animal hide hair removal and calcification comprises (%w/w): 1-10 ammonium-, alkaline metal- and/or alkaline earth metal polysulphates and 2-40 acid amide.

Description

The present invention relates to a composition for depilation and liming of animal skins. The animal skins suitable for the composition are gentle, non-water-soluble and do not leave water-insoluble residues.

The effect of hair removal agents can be traced back to two processes:

1.) Reduction, i.e. solubility, of keratin disulfide bridges in hairs. '9

2.) For solubilization of proteins by hydrolysis. In addition to completing the above two processes, it is important that the surface of the skin is not damaged; the previous two processes are limited to the hairs. A further requirement is that after the epilation, liming c, insoluble residues do not contaminate the skin, as this is a further, subsequent removal! requires action. In the past, lime milk (W. Grassmann, editor, Handbuch dér Gerbereichemie und Lederfabrikation, Vol. 1, Band 2, Die Wasser-Werkstatt, Springer, 1938, Wien) was used for depilation and liming, but its disadvantageous properties (low solubility). , does not reduce, destroys the skin surface, forms water-insoluble calcium carbonate deposits).

Its place has been taken up by sulphide-containing liming agents which, in addition to sodium and / or calcium sulphide, contain alkalizing agents such as lime and soda ash. Their disadvantage is that when used, there is a risk of developing hydrogen sulphide, calcium-containing lime deposits on the skin, while caustic soda can cause skin damage. To counteract this latter effect, the addition of saline, calcium chloride, and aliphatic amines has been introduced, which, however, softens the surface of the skin and thus contributes to its damage both mechanically and chemically,

Particularly disadvantageous when using sulfide-containing limestones is the fact that lime treatment must always be used as a finishing operation, which again leads to the aforementioned harmful calcium carbonate deposition. Removing this requires another technological step: acid descaling. 40

The object of the present invention was to provide a depilatory, liming composition which, in addition to its stronger reducing and hydrolyzing properties, does not damage the skin surface, does not form water-insoluble deposits and thus does not require subsequent operations. 45

Thus, the present invention provides a composition for depilation, liming of animal skins, comprising 1-5% by weight, preferably 1-3% by weight of ammonium, alkali metal, alkaline earth metal polysulphide, wherein the stoichiometric ratio of cation Jcene is 1: 0.6-6. ), preferably 1: (1,4-3), to provide 15-25% by weight of N-substituted, unsubstituted formic acid, acetic acid amido and carbonic diamido and alkalinity pH = 9.5-11, hydroxide solution.

According to the present invention, the polysulfide of the formula I is used in an amount of 1 to 5% by weight, preferably 1 to 3% by weight, wherein M is ammonium, sodium, potassium, calcium cation, n is 1 or 2 and x 0.6-6, preferably 1.4-3.

The composition of the invention comprises an acid amide of general formula 15 to 25% by weight of (II), wherein Y is hydrogen, chloromethyl, containing methyl or amino, R ^r and ^R are identical and represent hydrogen or methyl.

The alkalinity of the composition is adjusted to the desired pH of 9.5 to 11, preferably 9.8 to 10.2 with ammonium hydroxide solution and diluted with water to the desired concentration.

The composition of the present invention can be produced in both batch and continuous operation. In a batch operation, the required amount of polysulfide, 70% by weight of the required water, acid amide is added to a vessel suitable for dissolving and mixing the individual components, then dissolved in ammonium hydroxide and adjusted to the desired pH with additional water.

It is irrelevant for the purposes of the present invention that these polysulphides are prepared by reaction of the appropriate alkali with sulfur, alkali, hydrogen sulfide and sulfur, or with a sulfide and sulfur, or in vessels suitable for dissolving the other components themselves, and using their solution, dissolve the remaining components therein.

In a continuous operation process, each component is added in the form of a solid or solution, together with the required water, to a suitable mixing unit, which may be a mechanical mixing vessel or a static mixing tube. After adjusting the residence time to ensure complete homogenization, the solution is adjusted to pH with ammonium hydroxide and the composition is transferred to the filling unit.

The composition of the present invention is illustrated by the following examples:

Example 1

Dissolve 2.56 kp of ammonium sulfide in 10 l of water and add 2.2 kp of smear during cooking. Dilute to 60 L and add 18 kp of dimethylformamide. Adjust the pH to 9.5 with 12 kp ammonium hydroxide and make up to 100 liters with water.

2nd-8th examples.

In the same manner as in Example 1, only the cation of the polysulphide and the amounts measured were changed according to Table 1:

192 421

Table 1 (Data for Examples 2-8)

Example of polysulfide formation 25% by weight of acid amide (kp) Final number of alkali (kp) sulfur (kp) NH 4 OH (kp) pH

- - *

2 KOH 3.2 3.6 chloroacetamide 15 14.2 9.8 3 NaOH 1.6 1.8 urea 18 9.6 10.2 4 NaOH 2.3 2.1 acetamide 15 13.8 10.0 5 CaO 2.3 2.1 chloroacetamide 15 14.2 10.1 6 CaO 2.3 1.8 urea 18 10.4 10.0 7 NaOH 1.1 2.1 Ν, Ν-dimethylformamide 14 17.0 10.2 8 NaOH 1.1 2.1 N, N-dimethylacetamide 16 17.0 10.2

The inventive composition is preferably exemplified by the application of bovine soaking-lime technology for the sorting, liming, spinning of animal skins in a state-of-the-art mixer using the modem Erhavit A (ROHH 0.5-1.5% w / w by skin). These advantages are numerically illustrated in Figure 9.

Example 9 (beef soaking-lime)

Operation number Erhavit A, liming agents time (H) According to the invention, composition, liming agents time (H) 1 1001 water 0.5 1001 water 0.5 2 1001 water 0.5 100 Flood 0.5 3 1001 water 0.1 kp moisturizer 3.5 lOOlvíz 0.1 kp moisturizer 3.5 4 1001 water 1.0 kp Na ₂ S 3.5 100 Flow 1.0 kp Na ₂ S 3.5 2.5 kp CaO. 2.0 - '- 1.0 kp Na ₂ S 4.5 1.0 kp Na ₂ S 2.0 5 100 kp of water 1 sec Arhavit 1 kp CaO 4.0 100 kp of water 1 kp composition 4.0 6 100 kp of water 0.3 100 kp of water 0.3 7 100 kp of water 0.3 100 kp of water 0.3

Quality Even Cattle Swollen Hair Decalcification Needed Even Cows Lightly Swollen Hair Decalcification Required

From the data of Example 9, it can be concluded that the composition of the present invention provides the following hair removal benefits:

- less time consuming - less use of chemicals and consequently less waste

- less swollen hair - descaling is not required. 60

Claims (3)

CLAIMS 1. An composition for depilation, liming of animal skins, wherein the polysulphide of formula (f) is present in an amount of from 1 to 5% by weight, wherein M is ammonium, an alkali or alkaline earth cation, n is 1 or 2, x is 192 421 From 0.6 to 6, preferably from 1.4 to 3, and comprises 15-25 wt% (II) amide of the formula wherein Y is hydrogen, chloro-methyl, 5-methyl or amino group, R ¹ and R ¹ are the same and a hydrogen atom or a methyl group in an amount of aqueous ammonium hydroxide solution needed to adjust the pH to 9.5-11. 2. The composition of claim 1. It is understood that the composition comprises polysulfide of ammonium, magnesium, sodium, or calcium. Composition according to claim 1 or 2, characterized in that it contains Ν, Ν-dimethylformartide Ν, Ν-dimethylacetamide, chloroacetamide or urea as the acid amide. 1 drawing Published by: National Office of Inventions Responsible publisher: Zoltán Himer o.v. CODE -4192.421 International class mark; C 14 C 1/06