Use of copolymers based on ethylenically unsaturated dicarboxylic acids or dicarboxylic acid anhydrides, lower olefins and hydrophobic comonomers for after-tanning, stuffing or waterproofing leather and furs

Aqueous solutions or dispersions of copolymers obtainable by free-radical copolymerization of(a) from 20 to 90% by weight of at least one monoethylenically unsaturated C4-6-dicarboxylic acid or the anhydride thereof, as component A,(b) from 5 to 50% by weight of at least one olefin having 2 to 6 carbon atoms, as component B,(c) from 5 to 50% by weight of at least one hydrophobic comonomer from the group consisting of long-chain olefins, esters of long-chain alcohols with acrylic acid or methacrylic acid, long-chain amides of acrylic acid or methacrylic acid, and long-chain alkyl vinyl ethers, as component C,(d) from 0 to 40% by weight of further comonomers which can be copolymerized with the above monomers, as component D,where the sum of the amounts of components A, B, C and, if used, D is 100% by weight, followed by at least partial esterification or hydrolysis and neutralization and/or reaction of the carboxyl groups formed during the hydrolysis with bases, for treating leather and/or fur skins.