Photosensitive compositions and lithographic printing plates with reduced propensity to blinding

Abstract From the Canadian patent

Photosensitive compositions, useful in lithographic printing plates which can be developed with aqueous developing solutions, comprise a diazo resin, an acid-substituted ternary acetal polymer and, a copolyester of an unsaturated dicarboxylic acid and an oxyalkylene ether of an alkylidene diphenol. The acid-substituted ternary acetal polymers are comprised of recurring units which include three six-membered cyclic acetal groups, one of which is unsubstituted or substituted with an alkyl or hydroxyalkyl group another of which is substituted with an aromatic or heterocyclic moiety, and a third of which is substituted with an acid group, an acid-substituted alkyl group or an acid-substituted …