Process for the preparation of opaque diketopyrrolo-pyrrole pigments
US4992101A · kind A · utility
10Cited by
6References
11Claims
0Family size
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Key dates
| Filing date | Sep 19, 1989 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Sep 19, 2009 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B67/0022
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
Process for the preparation of opaque 1,4-diketopyrrolo-[3,4-c]pyrroles of the formula ##STR1## wherein one of R.sub.1 and R.sub.2 is hydrogen, halogen or C.sub.1 -C.sub.4 -alkyl and other is hydrogen, which process essentially consists of milling the pigment in an alcohol and in the presence of a base at a temperature below 50.degree. C., the resulting product being a highly crystalline readily dispersable diketopyrrolopyrrole pigment having outstanding color strength, purity of shade and saturation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.