| abstract |
Method for thickening an aqueous system, which comprises incorporating into said system a thickening agent in situ with uniform mixing, said thickening agent comprising the latex composition, prepared by subjecting in emulsion polymerization, in an aqueous acidic medium, a monomeric material containing 20 to 55% by weight of methacrylic acid, up to 10% of which may be replaced by one or more different monomers, each of which contains at least one carboxyl group, from 3 to 35% by weight of an ester of a Ethylenically unsaturated carboxylic acid anhydride and a polyoxyethylated alcohol or phenol, the balance comprising at least about 35% by weight of styrene, butadiene, or a mixture thereof, optionally together with a small amount of one or more additional copolymerizable, ethylenically unsaturated monomers, and in which method an alkaline material is then added with stirring to the aqueous system, to adjust the system to a pH of 8 to 1 0. (Machine-translation by Google Translate, not legally binding) |