Process for producing coated TiO.sub.2 pigment using cooxidation to provide hydrous oxide coatings
US5922120A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 23, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | Dec 23, 2017 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2004/84
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.