Process for the manufacture of organosilicon compound-treated pigments
US7250080B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 6, 2006 |
| Grant date | Jul 31, 2007 |
| Priority date | — |
| Expiry date | Sep 6, 2026 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2004/84
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
An improved process for making an organosilicon compound surface-treated titanium dioxide material, comprising (a) forming a mixture of the titanium dioxide material in water, (b) wet milling the mixture, (c) adjusting the pH of the slurry resulting from step (b) to between about 5.0 and about 8.5, (d) after step (c), removing the titanium dioxide material from the mixture by vacuum or pressure filtration, (e) after step (d), washing the titanium dioxide material so removed, (f) after step (e), converting the washed titanium dioxide material to a fluid dispersion having a pH of from about 3.5 to less than about 7 via addition of a fluidizing agent comprising a water-soluble monoprotic acid, (g) after, or concurrently with, step (f), adding to the resulting dispersion of titanium dioxide material an organosilicon compound, with mixing, and (h) spray drying the dispersion of the washed titanium dioxide material resulting from step (g) to yield a dry titanium dioxide pigment powder.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.