Imaging system employing photosensitive microcapsules containing 3-substituted coumarins and other photobleachable sensitizers

Claim 1

An imaging sheet useful in forming full color images comprising a support having on a surface thereof a layer containing three sets of microcapsules having distinct sensitivities and containing respectively cyan, magenta, and yellow image-forming agents; one of said three sets of microcapsules being blue light-sensitive and including in the internal phase thereof a free radical addition polymerizable material and a photoinitiator system including a photobleachable sensitizer, said sensitizer being bleachable upon exposure to radiation in the wavelength range of 390 to 500 nm and being represented by formula (I): ##STR10## wherein Q is --Z--R 1 , Z is carbonyl, R 1 is a hydroxyl group, an alkenyl group, an alkoxy group, an alkyl group, an aryl group, a carboxyclic group or a heterocyclic group; R 2 , R 3 , R 4 and R 5 each independently represent hydrogen, an alkoxy group, a dialkylamino group, a halogen atom, an acyloxy group, a nitro group, a 5- or 6-membered heterocyclic group, or a group having the formula (II): ##STR11## wherein R 9 is an alkylene group; R 6 is hydrogen, an alkyl group or an aryl group; and wherein two or three of R 2 , R 3 , R 4 and R 5 and the nuclear carbon atoms to which they are attached can together form a fused ring or fused ring system, each ring being a 5- or 6-membered ring.