Patent ID: 8349981

Claim:
An anionically modified copolymer obtained by polymerization of monomers (A), (B), (C) and (D) to obtain nonionic copolymers having reactive terminal OH groups, and subsequent conversion of the terminal OH groups to anionic end groups, 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) where 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 copolymer is of the formulae (V) or (VI) wherein A is C 2 -C 4 -alkylene, B is a C 2 -C 4 -alkylene other than A, D is a C 3 -alkylene, m is from 1 to 500; n is from 1 to 500; and the sum total of m+n is from 2 to 1000; o is from 2 to 500; 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, Z c is H or (C 1 -C 4 )-alkyl; R is hydrogen or methyl, R 1 is hydrogen or methyl, R 2 is hydrogen or methyl, Y is an aliphatic hydrocarbon 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, W b is oxygen or an NH group; X b is an aromatic or araliphatic radical having 3 to 30 carbon atoms optionally containing heteroatoms selected from the group consisting of O, N and S, W a is oxygen or an NH group, Q is SO 3 , CH 2 COO, PO 3 M or sulfosuccinate, and M is H, a metal cation, an ammonium, an alkylated ammonium ion, or a combination thereof; a=0.001-0.9 b=0.001-0.9 c=0.001-0.9 d=0.001-0.9 subject to the proviso that the sum total of a+b+c+d is equal to 1.