Abstract: A photosensitive resin printing plate precursor including: a photosensitive resin layer (A) containing a water-soluble or water-dispersible resin and an ultraviolet-curable monomer; and a water-insoluble heat-sensitive mask layer (C) containing an infrared-absorbing material, deposited in that order on a support is disclosed. By introducing a crosslinked structure or a hydrophobic constituent to the heat-sensitive mask layer (C) so as to be insoluble in water, a difference in polarity is produced between the layers (A) and (C) and, thus, mass transfer between the two layers can be prevented. Also, the scratch resistance of the heat-sensitive mask layer (C) can be dramatically enhanced and, thus, the printing plate precursor becomes easy to handle.

Abstract: An object of the present invention is to provide a photosensitive resin printing plate precursor capable of forming a protruding relief pattern without using any original pattern film. Specifically, the present invention relates to a photosensitive resin printing plate precursor including: a photosensitive resin layer (A) containing a water-soluble or water-dispersible resin and an ultraviolet-curable monomer; and a water-insoluble heat-sensitive mask layer (C) containing an infrared-absorbing material, deposited in that order on a support. By introducing a crosslinked structure or a hydrophobic constituent to the heat-sensitive mask layer (C) so as to be insoluble in water, difference in polarity is produced between the layers (A) and (C) and, thus, mass transfer between the two layers can be prevented. Also, the scratch resistance of the heat-sensitive mask layer (C) can be dramatically enhanced and, thus, the printing plate precursor becomes easy to handle.

Abstract: Disclosed are a photosensitive resin composition essentially comprising 100 parts by weight of modified polyvinyl alcohol comprising a structural units of formulae (I), (II) and (III): ##STR1## wherein R represents a hydrocarbon group having 1 to 20 carbon atoms; X represents an aliphatic, alicyclic or aromatic divalent hydrocarbon group having 1 to 20 carbon atoms or a divalent group having at least one carboxyl group in the molecule thereof, the proportion of the structural unit of formula (I) being from 1 to 40 mol %, the total proportion of the structural units of formulae (II) and (III) being from 60 to 99 mol %, and the carboxyl equivalent attributed to the structural unit of formula (III) being from 0.3 to 5 mol/kg, (B) from 0.1 to 10 parts by weight of an unsaturated epoxy compound, (C) from 20 to 200 parts by weight of a polymerizable unsaturated compound having an ethylenical double bond in the molecule thereof, and (D) from 0.1 to 10 parts by weight of a photopolymerization initiator.