Lead chromate pigment with improved thermal stability
US4059459A · kind A · utility
1Cited by
3References
5Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1976 |
| Grant date | Nov 22, 1977 |
| Priority date | — |
| Expiry date | Oct 7, 1996 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/32
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Dense silica-coated lead chromate pigment prepared by adding from 0.2% to 1% by weight of a soluble silicate compound to an aqueous solution of chromate, and, optionally, at least one of sulfate and molybdate, contacting the aqueous solution with an aqueous lead salt to precipitate the base lead chromate pigment, treating the pigment with at least one hydrous oxide, and applying from 2% to 40% by weight of dense, amorphous silica to the treated lead chromate pigment. The resulting dense silica-coated lead chromate pigment exhibits higher thermal stability in plastics than conventional dense silica-coated lead chromate pigment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.