Chalking-resistant titanium dioxide pigment
AssigneeBayer Aktiengesellschaft
InventorsHeinz-Peter Hemmerich, Hans Jurgen Rosenkranz, Wolfgang Papenroth, Aloys Klaeren
Life of this patent
Estimating the term…
Abstract
A chalking-resistant titanium dioxide pigment is produced by mixing the pigment with a vinyl polymer, in form of an aqueous latex, applying the polymer to the pigment in quantities of about 0.1 to 30% by weight based on the final pigment and the mixture containing at least about 30% of water by weight. The polymer is then coagulated, the aqueous phase separated and the pigment-plus-polymer dried. Due to some apparent complexing, the polymer cannot be quantitatively dissolved away from the pigment. The pigment produces chalking-resistant lacquers, paints and coating compositions.
Claims6
In the production of a chalking-resistant titanium dioxide pigment by organic aftertreatment with a vinyl polymer in aqueous phase, separation of the aqueous phase and drying, the improvement comprising mixing the titanium dioxide pigment with a vinyl polymer in form of an aqueous latex, thereby applying the vinyl polymer to the pigment in quantities of at least about 0.1% by weight based on the final pigment, the water content of the mixture being at least about 30% by weight, and then coagulating the latex to separate the polymer-containing pigment from the aqueous phase.
Dependencies are inferred from the claim text.