Abstract: Acrylic emulsion copolymers are prepared by emulsion polymerization of (A) a surfactant monomer, (B) an .alpha.,.beta.-ethylenically unsaturated carboxylic acid monomer, (C) a nonionic .alpha.,.beta.-ethylenically unsaturated monomer and (D) optionally a polyethylenically unsaturated cross-linking monomer. The surfactant monomer is prepared by condensing a polyhydric alcohol or primary amine-containing nonionic surfactant with a monoethylenically unsaturated monoisocyanate. At a low pH the copolymer may be in the form of an aqueous dispersion or latex, but thickens upon neutralization of at least some of the carboxyl groups.