Patent ID: 7655279

Claim:
A passivating layer on a metal surface, obtained by contacting the metal surface with a composition comprising a copolymer as component A, synthesized from aa) 50 to 99.9% by weight of (meth)acrylic acid or salts thereof as component Aa; ab1) 0.1 to 50% by weight of a carboxylate-containing monomer of the formula I in which the symbols have the following definitions: n is 0 to 10, R 1 R 2 and R 3 independently of one another are hydrogen, C 1 to C 18 alkyl, which is branched or unbranched, C 3 to C 6 cycloalkyl, C 2 to C 18 alkenyl, which is branched or unbranched, C 3 to C 6 cycloalkenyl, C 6 to C 12 aryl, which is unsubstituted or substituted by alkyl substituents or aryl substituents, R 1 , R 2 and/or R 3 are optionally substituted by at least one carboxyl group, or are a carboxyl group; R 4 and R 5 are independently of one another hydrogen, C 1 to C 18 alkyl, which is branched or unbranched, C 3 to C 6 cycloalkyl, C 2 to C 18 alkenyl, which is branched or unbranched, C 3 to C 6 cycloalkenyl, C 6 to C 12 aryl, which is optionally substituted by alkyl substituents or aryl substituents; or salts, anhydrides, esters of compounds of the formula I, with the exception of (meth)acrylic acid or salts thereof, as component Ab1; and ab2) 0.1 to 50% by weight of monomers containing groups containing phosphonic acid or salts thereof, as component Ab2, and polymerizable with the monomers specified under aa) and ac), and also with component Ab1; ac) 0 to 30% by weight of further comonomers polymerizable with the monomers specified under aa) and ab1), and ab2) as component Ac.