Light-sensitive planographic printing plate with layer of diazo resin containing photopolymerizable composition

Claim 1

A light-sensitive planographic printing plate comprising a layer of a photo-polymerizable composition provided on at least one side of a base, wherein said photo-polymerizable composition is soluble in an organic solvent and comprises in admixture: (A) a polymer which is a copolymer of methacrylic acid and a monomer having an unsaturated group represented by the general formula (I) ##STR10## wherein R 1 to R 5 each represent a member selected from the group consisting of a hydrogen atom, a halogen atom, a carboxyl group, a sulfo group, a nitro group, a cyano group, an amido group, an amino group and a substituted or unsubstituted alkyl group, aryl group, alkoxy group, aryloxy group, alkylamino group, arylamino group, alkylsulfonyl group and arylsulfonyl group and Z represents an oxygen atom, a sulfur atom, NH or NR, wherein R represents and alkyl group; wherein said monomer is selected from the group consisting of allyl methacrylate, cinnamoyl methacrylate, crotonyl methacrylate and methallyl methacrylate, and wherein the monomer content and the methacrylic acid content in said polymer are 10 to 90% by mol and 5 to 60% by mol, respectively; (B) a monomer or oligomer having at least two polymerizable ethylenically unsaturated bonds; (C) a photo-polymerization initiator; and (D) a diazo resin soluble in organic solvents and which is the reaction product of a condensate product with an anion, wherein said diazo resin (D) is homogenously blended with components (A)-(C) in an amount of from 1-30% by weight based on the total amount of the photo-polymerizable composition, wherein the weight ratio of component (B) to polymer (A) is in the range of from 1:9 to 7:3 and wherein the amount of component (C) employed is from about 0.5% by weight to about 15% by weight based on the total weight of the photo-polymerizable composition.