Use of isoindoline pigments for photoelectrophoretic imaging
US4427752A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 28, 1982 |
| Grant date | Jan 24, 1984 |
| Priority date | — |
| Expiry date | Apr 28, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03G17/04
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A photoelectrophoretic imaging process, wherein a suspension of photosensitive pigment particles between two electrodes, at least one of which is transparent, is subjected to the influence of an electric field and exposed to an image, which process comprises using, as photosensitive pigment, an isoindoline of the formula ##STR1## wherein R.sub.1 and R.sub.3 are cyano, --COOR or --CONHR', in which R is alkyl, cycloalkyl, aryl or a heterocyclic aromatic radical, and R' is hydrogen, alkyl, cycloalkyl, aryl or a heterocyclic aromatic radical, R.sub.2 and R.sub.4 are cyano, or wherein R.sub.3 and R.sub.4, together with the carbon atom linking them, form a heterocyclic 6-membered ring. The pigments used in this invention are distinguished by particularly good photoelectrophoretic sensitivity and low fog density.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.