PURPOSE: To obtain a photosensitive material large in reduction degree, and small in fluctuation of reduction performance, by forming an upper nonphotosensitive layer on the upper part of a photosensitive silver halide emulsion layer, and using a combination of a polymer hardening agent and a low mol. wt. hardening agent having activated vinyl groups, and rendering the necessary melting time of the nonphotosensitive layer longer than that of the photosensitive layer.
CONSTITUTION: A combination of a polymer hardening agent and a low mol. wt. hardening agent having activated vinyl groups is used for a photosensitive material for plate making, and at least one of upper nonphotosensitive layers is hardened so as to have a melting time longer than that of the photosensitive silver halide emulsion layer. It is desired for the nonphotosensitive layer to be given a melting time longer by ≥100sec than the photosensitive layer by setting an amt. of hardening agent to be used. To synthesize a typical vinyl sulfonic group used for synthesis of said polymer hardening agent, 2-(3-chloroethylsulfonyl)-propionyloxy-ethyl acrylate is usable. A typical example of said low mol. wt. hardening agent having activated vinyl groups is CH2=CHSO2CH2 CH2CH2SO2CH=CH2, etc.
NAKAMURA TAKU
MORIUCHI SHIGENORI
URATA YUKIHIDE
