Patent attributes
A process for preparing a water-soluble carboxyl group-containing polymer comprising reacting an α,β-unsaturated carboxylic acid with a compound having at least two ethylenically unsaturated groups in an inert solvent in the presence of a radical polymerization initiator, the process for preparing a water-soluble carboxyl group-containing polymer being characterized in that the α,β-unsaturated carboxylic acid is further added to a reaction mixture in which 20 to 70% by mol of an unreacted α,β-unsaturated carboxylic acid remains, and the α,β-unsaturated carboxylic acid is reacted with the compound having at least two ethylenically unsaturated groups; and a water-soluble carboxyl group-containing polymer obtainable by the above-mentioned process, wherein the reducing ratio of viscosity of a 0.2% by weight neutralized viscous liquid is less than 25%, and the equilibrium viscosity of the neutralized viscous liquid is 20000 to 50000 mPa·s. The water-soluble carboxyl group-containing polymer obtainable by the present invention can be suitably used as a thickener for cosmetics and the like, a moisturizer for poultices and the like, an emulsifier, or a suspension stabilizer for suspensions, and the like.
