Patent ID: 6033442
Filing Date: 2000-03-07
Classification: C08F,C14C

Abstract:
A method of self-tanning, pre-tanning or assist tanning leather pelts or skin pelts or of retanning leather or skins, which comprises using, as a tanning agent, an aqueous solution or dispersion of copolymers composed ofA) from 5 to 95 mol % of ethylenically unsaturated mono- or dicarboxylic acids having 3 to 10 carbons, their anhydrides, their alkali metal, alkaline earth metal or ammonium salts, or mixtures thereof,B) from 5 to 95 mol % of ethylenically unsaturated acetals, ketals or orthocarboxylic esters of the formula I ##STR8## wherein R.sup.1 and R.sup.2 independently are hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.1 -C.sub.10 -alkoxy, amino, C.sub.1 -C.sub.4 -alkylamino or di-C.sub.1 -C.sub.4 -alkylamino,R.sup.3, R.sup.4, R.sup.5, R.sup.6, R.sup.8, R.sup.9, R.sup.10 and R.sup.11 independently are hydrogen C.sub.1 -C.sub.10 -alkoxy, amino, C.sub.1 -C.sub.4 -alkylamino, di-C.sub.1 -C.sub.4 -alkylamino, C.sub.6 -C.sub.14 -aryl, C.sub.7 -C.sub.18 -aralkyl, carboxyl, C.sub.1 -C.sub.20 -alkoxycarbonyl, C.sub.2 -C.sub.18 -alkyl interrupted by 1-5 nonadjacent oxygens, or are sulfo or phosphono,R.sup.7 is hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.6 -C.sub.14 -aryl, C.sub.7 -C.sub.18 -aralkyl or C.sub.1 -C.sub.10 -acyl,R.sup.12 is hydrogen, C.sub.1 -C.sub.10 -alkyl, C.sub.1 -C.sub.10 -alkoxy, hydroxyl or C.sub.1 -C.sub.10 -acyloxy, anda, b, c and independently are 0 or 1, it also being possible forR.sup.2 and R.sup.4 together to form a 1,3- or 1,4-alkylene group of 3 to 12 carbons and forR.sup.5 and R.sup.7 together to form a 1,2- or 1,3-alkylene group of 2 to 12 carbons, andC) from 0 to 70 mol % of other copolymerizable monomers,or their hydrolysis products or polymer-analogous reaction products.