Preparation of pigmentary 2,9-dichloroquinacridone
US5424429A · kind A · utility
18Cited by
12References
20Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1993 |
| Grant date | Jun 13, 1995 |
| Priority date | — |
| Expiry date | Sep 15, 2013 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B67/0036
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
A process for the direct preparation of pigmentary 2,9-dichloroquinacridone, which comprises oxidizing 2,9-dichloro-6,13-dihydroquinacridone directly to pigmentary 2,9-dichloroquinacridone by heating a reaction mixture comprising 2,9-dichloro-6,13-dihydroquinacridone, an alkali metal hydroxide, a water-soluble organic solvent, water and effective amounts of an oxidizing agent and a phthalimidomethylquinacridone particle growth inhibitor. The process yields pigmentary 2,9-dichloroquinacridone directly; without the need for additional particle-size reducing aftertreatments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.