Preparation of pigmentary grade pigment from crude pigment
US4541872A · kind A · utility
19Cited by
1References
13Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 26, 1984 |
| Grant date | Sep 17, 1985 |
| Priority date | — |
| Expiry date | Mar 26, 2004 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B67/0014
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Finished grade pigments are prepared from crude pigment precursors by conversion to aggregated low crystallinity pigment followed by milling the aggregated low crystallinity pigment in water having a pH of from 7 to 14 and from 5 to 25% based on pigment of a separate phase comprising an organic liquid which is effective in growing and improving the crystallinity of the pigment particles. The resulting material is extracted in dilute acid, washed free of acid and dried to produce the final finished grade pigment.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.