Abstract: A water soluble copolymer useful as an inorganic pigment dispersant is comprised of a polymerized (1) monomer which is an ethylenically unsaturated organic phosphate or phosphonate and (2) an ethylenically unsaturated carboxylated monomer, wherein the amount of the ethylenically unsaturated carboxylated monomer is sufficient to permit the copolymer to associate with an inorganic pigment in an aqueous medium in a manner which disperses the inorganic pigment in the aqueous medium to form a stable aqueous dispersion of the inorganic pigment. The pigment dispersants according to the invention are particularly useful for dispersing concentrated ZnO slurries having a ZnO content of up to about 70% and in slurries containing ZnO in the presence of TiO2.

Abstract: A method of preparing an inorganic pigment dispersion useful in the preparation of latex paints is provided. The method comprises dispersing an inorganic pigment in an aqueous medium further comprised of a dispersing polymer, said aqueous medium being essentially free of volatile organic solvents. The dispersing polymer is derived from monomers consisting essentially of an ethylenically unsaturated aromatic monomer having an unsubstituted ethylenic group, an ethylenically unsaturated aromatic monomer having an alkyl-substituted ethylenic group, and an ethylenically unsaturated acid monomer. The amount of the ethylenically unsaturated acid monomer is sufficient to permit the dispersing polymer to associate with an inorganic pigment in an aqueous medium in a manner which disperses the inorganic pigment in the aqueous medium to form a stable aqueous dispersion of said inorganic pigment.