| 摘要 |
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 <IMAGE> (I) wherein R1 and R3 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, R2 and R4 are cyano, or wherein R3 and R4, 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. |
