Patent ID: 6384166
Filing Date: 2002-05-07
Classification: C08F

Abstract:
A low color or colorless polymaleate as determined by a Gardner color number of 8 or less, said polymaleate is prepared by aqueous solution polymerization comprising:(a) 70 to 99.9 weight percent of maleic acid; (b) 0.1 to 30 weight percent of an allylic sulfonate monomer having the formula wherein R1 is selected from the group consisting of H, C1-C4 alkyl, C1-C6 alkoxy, C6-C10 aryl, ester, and COOH; R2 is Oâ€”R3 wherein R3 is selected from the group consisting of C1-C4 alkyl, C1-C6 alkoxy, and C6-C10 aryl; n is from 0 to 1, and M+ is a cation selected from the group consisting of H+, NH4+, alkali metals, alkaline earth metals, and quaternary organic amines, and wherein said allylic sulfonate is selected from the group consisting of sodium methallyl sulfonate, sodium allyl sulfonate, and sodium 1-allyloxy-2-hydroxypropyl sulfonate; and(c) 0.5 to 50 &mgr;m, based on the moles of monomer, of a polyvalent transition metal ion selected from group consisting of Group IVA, VA, VIA, VIIA, VIIIA, IB, IIB, and combinations thereof; wherein the weight percents are based on the total weight of monomer, provided that 10 to 60 mole percent of the carboxylic acid groups on the maleic acid are neutralized prior to polymerization.