| abstract |
(57) [Problem] To provide a water-soluble thickener having excellent usability and safety without decreasing viscosity in a cosmetic formulation in a wide pH range. SOLUTION: A copolymer obtained by copolymerizing 2-acrylamido-2-methylpropanesulfonic acid or a salt thereof with hydroxyethyl methacrylate or vinylpyrrolidone and a crosslinkable monomer, or a copolymer obtained therefrom is further treated with an alkali agent. A water-soluble thickener comprising a copolymer obtained by neutralization. |