Patent ID: 7241834

Claim:
A method for improving the scrub resistance of a dry coating comprising: a) forming an aqueous coating composition comprising an aqueous acrylic emulsion polymer, said polymer comprising, as copolymerized units, 70 to 99.5% by weight, based on dry polymer weight, monoethylenically unsaturated nonionic (meth)acrylic monomer and from 0.3 to 10% by weight, based on dry polymer weight, monoethylenically unsaturated acid monomer, wherein at least 40% by weight, based on dry polymer weight, of said emulsion polymer is formed by redox polymerization in the presence of 0.001 to 0.05 moles chain transfer agent per kg dry polymer weight; b) applying said coating composition to a substrate; and c) drying, or allowing to dry, said applied coating composition.