Photosensitive resin composition for lithographic printing plate and lithographic printing original plate

A photosensitive resin composition for a lithographic printing plate comprising not less than 10% by weight and not more than 90% by weight of a hydrophilic polymer having at least a hydrophilic group, based on the amount of the photosensitive resin composition, and not less than 0.5% by weight and not more than 20% by weight, based on the amount of the hydrophilic polymer, of a compound represented by formula (1):

• 4
• wherein X represents at least one selected from the group consisting of CHR1=CR2- and N(R3)(R4);
• each of R1, R2, R3 and R4 independently represents at least one selected from the group consisting of hydrogen atom, an alkyl group, an alkoxy group, an aryl group and a heterocyclic group, Y1 and Y2 independently represent at least one selected from the group consisting of hydrogen atom, an alkyl group, an alkoxy group and an aryl group, or Y1 and Y2 are taken together to form a ring with the nitrogen atom and the ring optionally contains at least one hetero atom.

A lithographic printing original plate comprising a hydrophilic photosensitive layer obtained from a photosensitive resin composition comprising not less than 10% by weight and not more than 90% by weight of a hydrophilic polymer having at least a hydrophilic group, based on the amount of the photosensitive resin composition, and not less than 0.5% by weight and not more than 20% by weight, based on the amount of the hydrophilic polymer, of a compound represented by formula (1):

• 5
• wherein X represents at least one selected from the group consisting of CHR1=CR2- and N(R3)(R4);
• each of R1, R2, R3 and R4 independently represents at least one selected from the group consisting of hydrogen atom, an alkyl group, an alkoxy group, an aryl group and a heterocyclic group, Y1 and Y2 independently represent at least one selected from the group consisting of hydrogen atom, an alkyl group, an alkoxy group and an aryl group, or Y1 and Y2 are taken together to form a ring with the nitrogen atom and the ring optionally contains at least one hetero atom.

A lithographic printing original plate comprising a hydrophilic resin photosensitive layer comprising a photosensitive resin composition comprising not less than 10% by weight and not more than 90% by weight of a hydrophilic polymer having at least a hydrophilic group, based on the amount of the photosensitive resin composition, and not less than 0.5% by weight and not more than 20% by weight, based on the amount of the hydrophilic polymer, of a compound that inhibits hydrogen bonding within the molecule and/or between the molecules of the hydrophilic polymer.