E.i. Dupont De Nemours and Company

John Steven Gergely

Alvin Allen

Narayanan Sankara Subramanian

Russell Bertrum Diemer, Jr

Pratibha Laxman Gai

Russell Bertrum Diemer

The present invention provides a process for producing titanium dioxide (TiO.sub.2) pigment having a coating comprising silica and a second oxide selected from the group consisting of oxides of boron, phosphorus, magnesium, niobium, germanium, and mixtures thereof, comprising the steps of (a) reacting titanium tetrachloride (TiCl.sub.4) in the vapor phase with an aluminum compound and an oxygen-containing gas in a reactor at a temperature in the range of about 900.degree. C. to about 1600.degree. C. to provide a gaseous suspension comprising TiO.sub.2 particles, (b) contacting the gaseous suspension comprising the TiO.sub.2 particles with a silicon halide and an oxide precursor of boron, phosphorus, magnesium, niobium, germanium, and mixtures thereof, and (c) cooling the gaseous suspension to produce TiO.sub.2 pigment having a coating comprising silica and a second oxide.

Process for producing coated TiO.sub.2 pigment using cooxidation to

The present invention provides a process for producing titanium dioxide (TiO.sub.2) pigment comprising boron oxide (B.sub.2 O.sub.3), comprising the steps of: (a) reacting titanium tetrachloride (TiCl.sub.4) in the vapor phase with an aluminum compound and an oxygen-containing gas in a reactor at a temperature in the range of about 900.degree. C. to about 1600.degree. C. to provide a gaseous suspension comprising TiO.sub.2 particles, and (b) contacting the gaseous suspension comprising the TiO.sub.2 particles with a boron compound to produce TiO.sub.2 pigment comprising B.sub.2 O.sub.3.

Growing community of inventors

Avondale, PA, United States of America

John Steven Gergely