Abstract: Horny substances are removed from animal hides by a process wherein animal hides are treated in a liquor comprising from 0.05 to 5% by weight, based on the salted weight, of one or more compounds of the formula I or the corresponding alkali metal or alkaline earth metal or ammonium or phosphonium salts thereof, the variables being defined as follows: R1 is selected from hydrogen and C1-C12-alkyl, unsubstituted or substituted by one or more S—H or O—H groups; X1 to X4 are identical or different and are selected from hydrogen, C1-C4-alkyl, O—H, S—H and N—HR2, R2 is hydrogen or C1-C12-alkyl or a C1-C4-alkyl-C?O group, at least one of the radicals X1 to X4 being S—H, and, if R1 contains neither O—H nor S—H, at least one further radical from among X1 to X4 is selected from S—H, OH and NH—R2, and furthermore with at least one compound which catalyzes the hydrolysis of peptide bonds.

Abstract: horny substances are removed from hides of dead animals by a process wherein the hides of dead animals are treated with at least one substance of the formula I or at least one corresponding alkali metal, alkaline earth metal, ammonium or phosphonium salt, where R1 and R4 are identical or different and are selected from hydrogen, C6-C14-aryl and C1-C12-alkyl, unsubstituted or substituted by one or more SH or OH groups, R2 and R3 are identical or different and are selected from hydrogen, C6-C14-aryl and C1-C12-alkyl, unsubstituted or substituted by one or more SH or OH groups, at least one radical R2 or R3 not being hydrogen or R1 and R4 not being hydrogen, and it being possible in each case for two vicinal radicals R1 to R4 together to be C3-C10-alkylene, R5 is selected from hydrogen, C1-C12-alkyl, H—C?O or C1-C4-alkyl-C?O, X1, X2, X3 and X4 are selected from OH, SH and NHR5, where, if R1 to R4 contain at least one sulfur atom, at least one radical X1 to X4 is SH, and, if R1 to R4 contain no sulf

Abstract: Semifinished products or leather are or is produced by a process in which pelts, pickled pelts or semifinished products are treated with a) at least one sheet silicate and b) at least one copolymer which is obtainable by copolymerization of at least one ethylenically unsaturated dicarboxylic anhydride (A), derived from at least one dicarboxylic acid of 4 to 8 carbon atoms, at least one vinylaromatic compound (B1) or at least one oligomer (B2) of branched or straight-chain C2-C10-alkene, at least one oligomer having an average molecular weight Mn of from 300 to 5 000 g/mol or being obtainable by oligomerization of at least 3 equivalents of C2-C10-alkene, and optionally at least one ethylenically unsaturated monomer (C) differing from (A) and having at least one hetero atom, and reaction with at least one compound (D) of the formula I a or I b and optionally hydrolysis with water or aqueous alkaline solution, where, in formula I a and I b, A1 are identical or different and are C2-C6-alkylene R1 is linear

Abstract: Leather is produced by a process comprising at least two of the following process steps A) to D): A) use of one or more polyelectrolytes in the production of semifinished products or intermediate products, comprising the addition of one or more polyelectrolytes in at least one of the steps (a) to (d) (a) together with from 0 to 1.5% by weight, based on the salted weight, of lime, immediately before or during liming, (b) before or during deliming, (c) before or during bating, (d) together with, altogether, from 0 to 3% by weight, based on the pelt weight, of alkali metal or alkaline earth metal salt, immediately before or during pickling; B) treatment of the hides during liming in an aqueous liquor with one or more compounds of the formula B.1 ?or the corresponding alkali metal, alkaline earth metal, ammonium or phosphonium salts thereof, R10 and X1 to X4 having the meanings stated in the description, with the proviso that at least two mercapto groups are present in the compound or the compounds B.

Abstract: A semifinished leather product is produced from an animal hide by pretanning with the use of a chromium-free tanning agent and of a clay mineral which, after stirring for 30 minutes in water at 50° C. at a circumferential rotor speed of from 5 to 25 m/s, has a number average particle diameter of less than 2 ?m or a bimodal particle size distribution with a first, finely divided fraction whose number average particle diameter is less than 0.5 ?m and a second, coarser fraction whose number average particle diameter is less than 5 ?m, determined in each case by the method according to ISO 13320-1, by combined laser light diffraction and light scattering, a proportion of the first, finely divided fraction being from 10 to 90% by weight, and drying of the pretanned animal hide to a water content of from 5 to 45% based on the total weight of the semifinished leather product.

Abstract: The invention relates to a method for removing horn substances from animal skin. Said method is characterised in that animal skins are treated in an aqueous bath containing between 0.05 and 5 wt. %—in relation to the weight of the salt—of at least one compound of general formula I or the corresponding alkali metallic salts or alkaline-earth metallic salts thereof or ammonium or phosphonium salts, the variables having the following definitions: R1 is selected from hydrogen or C1-C12 alkyl, unsubstituted or substituted by at least one S—H group or one O—H group; X1 to X4 are the same or different and selected from hydrogen, C1-C4 alkyl, O—H, S—H or N—HR2; and R2 represents hydrogen or C1-C12 alkyl or a C1-C4-alkyl-C?O group, at least one X1 to X4 representing S—H. If R1 contains neither O—H nor S—H, at least one other X1 to X4 is selected from S—H, OH or NH—R2. Said aqueous bath also comprises at least one compound which catalyses the hydrolysis of peptide compounds.

Abstract: Horny substances are removed from hides, pelts or skins of dead animals by treating the hides, pelts or skins in aqueous liquor with one or more compounds of the formula I or their corresponding alkali metal or alkaline earth metal salts or ammonium or phosphonium salts, the variables being defined as follows: R1 is selected from hydrogen and C1-C12-alkyl, unsubstituted or substituted by one or more S—H or O—H groups; X1 to X4 are identical or different and are selected from hydrogen, C1-C4-alkyl, O—H, S—H and N—HR2, R2 is hydrogen or C1-C12-alkyl or a C1-C4-Alkyl-C?O group, at least one radical X1 to X4 being S—H when R1 contains at least one sulfur atom and at least two radicals X1 to X4 being S—H when R1 contains no sulfur atom.

Abstract: A process for the production of semifinished products and intermediates in the production of leather using one or more organic polyelectrolytes comprises at least one of the following steps: (a) Addition of one or more polyelectrolytes and from 0 to 0.7% by weight, based on the salted weight, of lime immediately before or during liming, (b) addition of one or more polyelectrolytes before or during deliming, (c) addition of one or more polyelectrolytes before or during bating, (d) addition of one or more polyelectrolytes and a total of from 0 to 3% by weight, based on the pelt weight, of alkali metal or alkaline earth metal salt immediately before or in the pickle.

Abstract: The invention relates to a tanning agent that is produced by reacting at least one aldehyde of general formula (I) with at least another identical or different aldehyde of formula (I), wherein the variables are defined as follows: Z is a single chemical bond, an optionally substituted C1-C12-alkyl, an optionally substituted C5-C12-cycloalkyl or an optionally substituted C6-C14-aryl, wherein the reaction is carried out in the presence of an acid catalyst and optionally in the presence of at least another carbonyl compound of formula (II), R1 to R4 represent, independent of one another, hydrogen, optionally substituted C1-C12-allyl, optionally substituted C3-C12-cycloalkyl, optionally substituted C7-C13-aralkyl or optionally substituted C6-C14-aryl, provided that at least another aldehyde of formula (I) in which the radical of Z contains ? hydrogen atoms or at least another carbonyl compound of formula (I) is present when Z is a single chemical bond or a radical without any hydrogen atoms.

Abstract: The present invention relates to C4-C6-polymercaptopolyols as regulators in the free-radically initiated solution and precipitation polymerization of ethylenically unsaturated monomers.

Abstract: An oligomerized polyorganosiloxane cocondensate which may be obtained, in part, by mixing an water-soluble amino-functional organosilane represented with at least one of the followoing: a fluoro-functional organosilane, an organosilane, and an organosilane. The cocondensate may be used, for example, in a method of treating surfaces.

Abstract: A method for preparing unhaired hides ready for tanning from hides and skins using proteolytic and lipolytic enzymes in the beamhouse, whereby in at least one of the partial steps of the beamhouse consisting of a) liming in the pH range 11.5-14 and b) bating in the pH range 5-11.5, alkaline lipases (E.C.3.1.3.) having an activity optimum in the pH range 9-11 are added to the aqueous floats corresponding to these partial steps.

Abstract: A method for liming hides and skins using a proteolytic enzyme in an aqueous-alkaline float is taught, wherein the liming float has a pH value from 10-14 and contains both thiourea dioxide and an alkaline protease having elastase activity.

Abstract: Liquid enzyme preparations comprising at least one anhydrous organic liquid as a vehicle for one or more enzymes and methods for using such preparations e.g. in beamhouse operations in the commercial production of leather.

Abstract: The soaking of hides and skins is enzymatically assisted in a method using an aqueous float having a pH from 9 to 11 which containsA) a lipase having an activity optimum in the pH region from 9 to 11,B) a protease with activity in the pH region from 9 to 11, andC) a surface active agent.

Abstract: A method for the wet degreasing of raw hides and skins, pelts, and wet blues under the conditions of enzymatic bating, wherein enzymatic bating of the hide stock is carried out with proteolytic enzymes in the presence of synthetic surface active substances, for example, a mixture of a non-ionic emulsifier and anionic emulsifier.

Abstract: Tanning agents containing a complex formed between chromium ions and an acrylate or methacrylate polymer and further including an organically bound thio group present in said polymer or in a mercapto compound added to the tanning agents, and methods for pickling, tanning, and retanning skins and hides with such tanning agents.

Abstract: A process for liming skins and hides with preservation and separation of the hair, including the following successive steps:(A) a soaking step in a aqueous liquor containing a surfactant;(B) an incubation step in an aqueous liquor free of inorganic sulfur but containing hydrotropes and organic sulfur compounds as unhairing agents;(C) an step for immunization of the hair at a pH between 10 and 14;(D) a hair loosening step in which inorganic sulfide is added to the float;(E) a separation step in which the hair is separated from the skins and hides; and(F) a liming step in which the pelts so obtained are limed in an aqueous alkaline liquor comprising liming aids.

Abstract: Liquid enzyme preparations comprising at least one anhydrous organic liquid as a vehicle for one or more enzymes and methods for using such preparations e.g. in beamhouse operations in the commercial production of leather.

Abstract: An enzymatic method for the unhairing of hides and skins in the alkaline pH range by treating them in a liquor at a pH from 9 to 11 with a proteolytic enzyme having an optimum activity in the pH range from 2 to 7.5, and then unhairing.