Copolymer dispersant composition for inorganic pigments

摘要

The present invention is directed to a pigment dispersant composition for use with inorganic pigments in coating compositions. The dispersant composition includes a vinyl or acrylic copolymer and a transition metal or rare earth metal salt. The metal salt in combination with the copolymer is useful with inorganic pigment as it lowers the viscosity of the pigment dispersions, thus allowing a higher concentration of pigment in the dispersion and consequently providing dispersions with higher non-volatile content and higher pigment to binder ratios. The presence of the metal salts in the dispersant composition when used with surface coated metal flake pigment provides excellent corrosion reduction of the metal pigment, indicated by the reduction or elimination of hydrogen gassing by the pigment in a coating composition.