The New Jersey Zinc Company

Gulf + Western Industries

John R Brand

A titanium dioxide pigment is provided for use in polymeric compositions comprising a pyrogenic titanium dioxide pigment which has been treated with a composition comprising an organophosphate/alkanolamine addition product. This invention provides for a novel method for treating a pyrogenic titanium dioxide pigment in order to reduce yellowing when such pigment is incorporated into a polymeric composition comprising adding to such pigment a composition which comprises an organophosphate/alkanolamine addition product.

Titanium dioxide pigment treated to suppress yellowing in polymers

A titanium dioxide pigment is provided for use in polymeric compositions comprising a pyrogenic titanium dioxide pigment which has been treated with an addition system comprising:

A weather-resistant TiO.sub.2 pigment having improved optical properties is provided. The pigment is substantially encapsulated with a coating of an amorphous, dense silica in an amount between about 1% and about 7%; a coating of a voluminous silica in an amount between about 1% and about 8%; and preferably a coating of a precipitated alumina in an amount between about 2% and about 8%. In a particularly preferred embodiment the pigment further includes an innermost coating of a precipitated alumina in an amount between about 0.2 and 0.6%, the percentages of silica and alumina being calculated as % SiO.sub.2 and Al.sub.2 O.sub.3 by weight, based on the final treated TiO.sub.2 pigment. A process for manufacturing the pigment is further provided.

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Palmerton, PA, United States of America

John R Brand