Patent ID: 9487670
Filing Date: 2016-11-08
CPC Classification: C01P,C08K,C09C,C09D

Claim Text:
1. A method for making a pigment grind dispersion of titanium dioxide pigment-polymer composite particles, which method comprises: (a1) mixing titanium dioxide particles with an aqueous emulsion containing water-insoluble film-forming first polymer particles that do not by themselves form composite particles with the titanium dioxide particles, and then (b1) adding an aqueous emulsion containing water-insoluble film-forming second polymer particles that adsorb to the titanium dioxide particles, or (a2) circulating an aqueous emulsion containing water-insoluble film-forming first polymer particles that do not by themselves form composite particles with titanium dioxide particles, and (b2) independently and concurrently adding to such first polymer particles (i) a dispersion of titanium dioxide particles and (ii) an aqueous emulsion containing water-insoluble film-forming second polymer particles that adsorb to the titanium dioxide particles, thereby forming titanium dioxide pigment-polymer composite particles that provide improved coating composition opacity compared to a coating composition that does not contain such composite particles.