| 摘要 |
PURPOSE: To provide a planographic printing plate hardly scratchable on the surface of diffusion transferred silver in printing, enhanced in water-holding property, and improved in ink transfer ratio and the storage stability of printing performance by incorporating a specified water-soluble oligomer in a layer containing physical development nuclei and/or its adjacent layer. CONSTITUTION: The planographic printing plate having a silver halide emulsion layer and the layer containing the physical development nuclei on a support contains the water-soluble oligomer having a molecular weight of <=2000 and N-methylolated acrylamide units in the molecule each represented by the formula in the layer containing the nuclei and/or its adjacent layer. In the formula, R1 is an H atom or a lower alkyl group. This oligomer is a dimer, trimer, or tetramer or the like, and if the average molecular weight is >=2000, its gradual diffusion into a gelatin layer and contribution to film hardening becomes difficult and resistances to scratching and staining, and ink transfer efficiency are deteriorated, and accordingly, it is preferred that the average molecular weight is 200-1800. |
