Patent ID: 6471885
Filing Date: 2002-10-29
Classification: C08F,C09D,C14C

Abstract:
An aqueous leather coating composition comprising a multi-stage aqueous emulsion-polymer comprising(i) a predominantly acrylic first stage polymer comprising at least one copolymerized monoethylenically-unsaturated nonionic monomer and from 0.5% to 10% of a copolymerized monoethylenically-unsaturated carboxylic acid monomer, based on the weight of said first stage polymer, said first stage polymer being substantially free from copolymerized multiethylenically-unsaturated monomer, said first stage polymer having Tg less than 10Â° C., said first stage polymer having been contacted with a transition metal oxide, hydroxide, or carbonate at a pH of less than 9 in an amount greater than 0.1 equivalent of transition metal per equivalent of said copolymerized carboxylic acid monomer in said first stage polymer; and (ii) a second stage polymer comprising at least one copolymerized monoethylenically-unsaturated nonionic monomer and from 0% to 10% of a copolymerized monoethylenically-unsaturated carboxylic acid monomer, based on the weight of said second stage polymer wherein said second stage polymer is formed in the presence of from 1% to 15% by weight based on the weight of said second stage polymer of chain transfer agent, provided that said second stage copolymerized carboxylic acid monomer is less than 25%, by weight, of the total copolymerized carboxylic acid monomer in said multi-stage emulsion polymer, said second stage polymer being substantially free from copolymerized multiethylenically-unsaturated monomer, said second stage polymer having Tg greater than 20Â° C.; and said second stage polymer being from 1% to 50% of the weight of said first stage polymer, based on dry polymer weights.