Valspar Sourcing, Inc.

Swimc LLC

Karl A Booth

Stephen M Korenkiewicz

Jeffrey F Taylor

Laura E Harris

Alexis R Kipping

A pigment grind dispersion contains non-adsorbed titanium dioxide particles dispersed in an aqueous emulsion containing a mixture of (a) water-insoluble film-forming first polymer particles that adsorb to titanium dioxide particles, the first polymer particle amount in the emulsion being less than the saturation level of adsorption when another polymer is not present, (b) water-insoluble film-forming second polymer particles that do not by themselves form composite particles with titanium dioxide particles, the second polymer particle amount in the emulsion being sufficient to inhibit or interfere with adsorption of the first polymer particles to titanium dioxide particles, and (c) extender particles. The pigment grind dispersion has a titanium dioxide pigment volume concentration of about 25 to about 50 and a titania composite ratio of about 32 to about 60.

Titanium dioxide pigment grind dispersion and paint

Titanium dioxide may be more efficiently used in a coating composition containing a composite pigment particle-forming polymer if during composite formation, the polymer is initially present in a low concentration and the titanium dioxide particles and newly-formed composite particles are dispersed in a waterborne emulsion polymer that does not form such a composite. A pigment grind dispersion of titanium dioxide pigment-polymer composite particles may be made by mixing titanium dioxide particles with the waterborne emulsion polymer. The composite-forming polymer is then added to the waterborne emulsion polymer, or is added independently and concurrently with the titanium dioxide particles. The resulting titanium dioxide pigment-polymer composite particles provide improved coating composition opacity compared to a coating composition that does not contain such composite particles. The coating compositions can contain reduced titanium dioxide amounts and less than a saturation level of the composite-forming polymer.

Method for making titanium dioxide pigment grind dispersion and paint

A pigment grind dispersion of titanium dioxide pigment-polymer composite particles is made by mixing titanium dioxide particles with an aqueous emulsion containing (i) less than a saturation level amount of water-insoluble film-forming first polymer particles that adsorb to the titanium dioxide particles, and (ii) an inhibiting or interfering amount of water-insoluble film-forming second polymer particles that do not adsorb to the titanium dioxide particles, wherein the pigment grind dispersion has a titanium dioxide pigment volume concentration of about 25 to about 50 and a titanic composite ratio of about 32 to about 60. The resulting titanium dioxide pigment-polymer composite particles can provide improved coating composition opacity compared to a coating composition that does not contain such composite particles, can employ reduced titanium dioxide amounts and less than a saturation level of the first polymer, and can provide improved storage stability.

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Minneapolis, MN, United States of America

Karl A Booth