Patent ID: 8372929

Claim:
A copolymer obtained by polymerization of monomers (A), (B), (C) and (D), wherein (A) is a monomer of formula (I) wherein A is C 2 -C 4 -alkylene, B is a C 2 -C 4 -alkylene other than A, R is hydrogen or methyl, m is from 1 to 500; n is from 1 to 500, and the sum total of m+n is from 2 to 1000; (B) is a monomer of formula (II) wherein D is C 3 -alkylene, R is hydrogen or methyl, o is from 2 to 500; (C) is an ethylenically unsaturated monomer containing an aromatic group; and (D) is an ethylenically unsaturated monomer containing an alkyl radical, wherein the monomer (C) is a compound of formula (IIIa) or (IIIb) wherein X a is an aromatic or araliphatic radical having 3 to 30 carbon atoms, optionally containing heteroatoms selected from the group consisting of N, O and S, Z a is H or (C 1 -C 4 )-alkyl, Z b is H or (C 1 -C 4 )-alkyl, and Z c is H or (C 1 -C 4 )-alkyl; wherein R 1 is hydrogen or methyl, X b is an aromatic or araliphatic radical having 3 to 30 carbon atoms optionally containing heteroatoms from the group consisting of N, O and S, W a is oxygen or an NH group and wherein the monomer (D) is a compound of formula (IV): wherein R 2 is hydrogen or methyl, Y is an aliphatic hydrocarbyl radical having 1 to 30 carbon atoms, optionally linear or branched or cyclic, and optionally contains heteroatoms selected from the group consisting of O, N and S and is optionally unsaturated, and W b is oxygen or an NH group.