Patent ID: 7317062

Claim:
A copolymer comprising a copolymerization product of (a) 1 to 80 mol % of at least one ethylenically unsaturated 1,2-dicarboxylic acid derivative, (b) 2 to 80 mol % of at least one unsaturated monocarboxylic acid derivative having 12 to 30 carbon atoms and having its unsaturated bond at a non-terminal position, (c) 1 to 90 mol % of at least one polyalkyleneoxyallyl ether having a number-average molecular weight of up to 5000 g/mol and (d) a 0 to 30 mol % of further, unsaturated monomer, which is not a monomeric compound of (a), (b) or (c); and a salt reaction product of the copolymer with ammonia, amines, water, alcohols, amino alcohols and/or alkali metal hydroxides or alkaline earth metal hydroxides.