Patent ID: 6891011

Claim:
A water-soluble or water-swellable copolymer obtained by free-radical copolymerization of A) 50 to 99% by weight of acryloyldimethyltaurine and/or acryloyldimethyltaurine based on a total weight of said copolymer, said acryloyldimethyltaurine and/or acryloyldimethyltaurine having a degree of neutralization of more than 80%, B) optionally, one or more other olefinically unsaturated, noncationic, comonomer containing at least one oxygen, nitrogen, sulfur or phosphorus atom and having a molecular weight of less than 500 g/mol, C) one or more olefinically unsaturated, cationic comonomer containing at least one oxygen, nitrogen, sulfur or phosphorus atom and having a molecular weight of less than 500 g/mol, D) optionally, one or more at least monofunctional, silicon-containing components capable of free-radical polymerization, E) optionally, one or more at least monofunctional, fluorine-containing components capable of free-radical polymerization, F) optionally, one or more mono- or polyolefinically unsaturated, optionally crosslinking macromonomers each possessing at least one oxygen, nitrogen, sulfur or phosphorus atom and having a number-average molecular weight of greater than or equal to 200 g/mol, the macromonomers not being a silicon-containing component D) or fluorine-containing component E), G) the copolymerization taking place in the absence of at least one polymeric additive having number-average molecular weight of from 200 g/mol to 10 9 g/mol. H) with the proviso that component A) is copolymerized with at least two components selected from at least two of the groups C) to F).