Patent ID: 7906591

Claim:
A process for modifying a (co)polymer (a) containing acid groups comprising reacting (a) with (b) wherein (a) is selected from one or more (co)polymer comprising at least 5% by weight of a (co)polymerized monoethylenically unsaturated monomer containing acid groups and having a weight average molecular weight from 1000 to 200,000, and (b) is selected from one or more compounds of formula I, II, III or IV wherein R 1 is selected from C 1 -C 50 alkyl; R 2 and R 3 are independently selected from H, methyl or ethyl; and R 4 is independently selected from C 1 -C 50 alkyl, hydroxyethyl, acetoxyethyl, hydroxy-isopropyl, or acetoxy-isopropyl; and n is an integer from 1-230; wherein the reaction of (a) and (b) is conducted at up to 250° C., and wherein (1) the (co)polymer(s) used as component (a) are obtained by free-radical polymerization of monoethylenically unsaturated acids in aqueous solution in the presence or absence of other monoethylenically unsaturated monomers and in the presence of at least 2% by weight, based on the monomers used in the polymerization, of a hypophosphite-containing chain transfer agent; or (2) wherein the reaction of (a) and (b) is chosen from esterification and amidation of (a) with (b) and, further wherein, the mixture of (a) and (b) comprises as an esterification or amidation catalyst a hypophosphorous acid or salt(s) thereof.