Patent ID: 7678515
Filing Date: 2010-03-16
Classification: B41M,Y10S

Abstract:
1. An image forming medium, comprising: a substrate; and an imaging layer coated on or impregnated into the substrate, wherein the imaging layer comprises an imaging composition that exhibits a reversible transition between a colorless state and a colored state and further comprises a thermally gated diarylethene photochromic material dissolved in a solvent or polymeric binder, and further wherein the diarylethene photochromic material comprises a diarylethene molecule represented by a general formula selected from the group consisting of wherein in formula (I) each X independently represents a hydrogen, an alkyl chain having 1 to 20 carbon atoms, cyano, fluorine, bromine, chlorine or an iodine atom; in formula (II) X represents S or O; in formula (IV) X represents S, O or C═O, and Y represents O, CH 2 or C═O; in formula (V) Y represents CH 2 or C═O; in formula (VI), X represents CH or N; in formula (VII), Y represents CH 2 or C═O; in formula (VIII), X represents S or O; and in formulas (II), (III), (V) and (VIII), R 1 -R 3 represents an alkyl group wherein the alkyl group can be a straight, branched or cyclic, substituted or unsubstituted, from 1 to about 40 carbon atoms, an substituted or unsubstituted aromatic or heteroaromatic group; further wherein: A represents a formula selected from the group consisting of (g), (h) and (i) as shown below; and B represents a formula selected from the group consisting of (j), (k) and (l) as shown below and further wherein: R R R R Q represents direct bonds, aryl, alkylaryl, heteroaryl, heteroalkylaryl, straight, branched or cyclic, hetero substituted or unsubstituted, alkyl groups from 1 to about 10 carbon atoms, alkenyl, alkynyl, or fluoroalkyl groups, wherein hetero atoms either may or may not be present and are optionally substituted; and U and Z each independently represent sulfur or oxygen atoms.