Triphendioxazine compounds
US6355795B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 2000 |
| Grant date | Mar 12, 2002 |
| Priority date | — |
| Expiry date | May 31, 2020 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B19/02
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
The triphendioxazine compounds of the general formula (I) in which the rings labelled A in positions 1,2-, 2,3- or 3,4- and 8,9-, 9,10- or 10,11- carry a linearly or angularly fused heterocyclic ring containing at least one nitrogen atom which is substituted or unsubstituted, with the proviso that compounds with only unsubstituted nitrogen atoms and symmetrically disubstituted compounds with C1-2alkyl and unsubstituted phenyl substituents are excluded, are outstanding pigments and are notable over the closest comparable pigments in particular for better migration, light and solvent fastnesses, better heat stability and enhanced coloring power and also better dispersibility and capability to be brought into pigment form.The invention also relates to a process for preparing these triphendioxazine compounds which is characterized by a cyclization step conducted in the presence of manganese dioxide and concentrated sulphuric acid.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.