Use of aromatic compounds as phase directors and particle size reducers for quinacridone pigments
US6626990B2 · kind B2 · utility
1Cited by
33References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 18, 2002 |
| Grant date | Sep 30, 2003 |
| Priority date | — |
| Expiry date | Mar 18, 2022 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B48/00
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The present invention relates to a process for producing alpha, gamma-I, gamma-II and gamma-III crystal modifications of quinacridone and transparent quinacridone pigments including the solid solutions of various quinacridones, using a variety of tris-aryl-s-triazines, particularly resorcinol triazine derivatives, or aromatic- or heteraromatic-compounds having at least one hydroxyl or keto group bonded to the ring, as an additive, prior to or concurrently with the oxidation of corresponding dihydroquinacridone salts.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.