Patent ID: 6040360
Filing Date: 2000-03-21
Classification: C01P,C08K,C09C,C09D

Abstract:
A waterborne coating composition comprising a principal resin selected from the group consisting of polyurethane resins, acrylic resins and mixtures thereof, water, an inorganic pigment used in mixture with a pigment treatment composition comprising ester resin selected from the group consisting of polyester, phosphate ester and pyrophosphate ester resins, aminoplast resin and solvent, wherein the pigment is selected from the group consisting of titanium dioxide, iron oxides, chromium oxides, lead oxides, zinc chromate, antimony oxides, cadmium sulfide, cadmium selenide and nickel titanate and any of the preceding pigments treated with aluminum oxides, and mixtures thereof, treated by a method ofa) forming a pigment treatment composition comprisingi) 25.0 to 65% by weight based on total pigment treatment composition weight of a resin selected from the group consisting of polyester resins having an acid number between 15 and 50, and phosphate ester and pyrophosphate ester resins having an acid number between 10 and 50, andii) 5.0 to 25.0% by weight based on total pigment treatment composition of an aminoplast resin, andiii) 10 to 45% by weight based on total pigment treatment composition of solvent selected from the group consisting of ethylene and propylene glycol ethers,b) combining the pigment treatment composition and the inorganic pigment to form a mixturec)grinding the pigment mixture to form a pigment paste, andd) forming a dispersion of the pigment grind, wherein the dispersion comprises between 1 and 20.0% by weight of the coating composition.