| 摘要 |
PURPOSE:To decrease deterioration in sensitivity, definition, and plate wear as against a light source for exposing red laser light by incorporating two kinds of specific sensitizing dyes into a photosensitive silver halide emulsion layer to prepare silver complex salt diffusion transfer lithographic printing plate. CONSTITUTION:The sensitizing dye expressed by formula I and the sensitizing dye expressed by formula II are incorporated into the silver halide emulsion layer. In formula I, R1, R2 denote an alkyl, alkenyl, aryl group, etc.: R3-R6 denote H, alkyl, alkoxy, aryl group, etc.: R7 denotes an alkyl, aryl group, etc.: Y1, Y2 denote O, S, Se, etc.: X denotes cation: (m) denotes 1, 0. In formula II, Z1, Z2 denote an atom. to form a 5- or 6-member contg. N heterocycle: R11, R12 denote an alkyl, alkenyl group, etc.: R13 denotes an alkyl, alkenyl group, etc.: R14-R16 denote H, alkyl, aryl group, etc.: R17 denotes H, alkyl, alkoxy, etc.: l is 0, 1: Y3 is S, O, etc.: X2 denotes anion: (m), (n), (q) denote 1, 2. Since the sensitizing dyes expressed by formulas I and II are incorporated into the above-mentioned layer, the change and deterioration in the sensitivity of the lithographic printing plate with natural aging are decreased. |
