| 摘要 |
PROBLEM TO BE SOLVED: To eliminate developing or a wiping operation and to improve sensitivity, resolution, printing characteristics by partially decomposing a photosensitive layer by irradiating with a light, losing a hydrophilic property of the layer, and changing the layer to an ink receptive property. SOLUTION: The plate for printing a lithographic plate comprises a hydrophilic resin photosensitive layer insoluble in water on a base plate, in such a manner that the layer loses its hydrophilic property by partially decomposing the layer by irradiating with a light and changes to an ink receptive property. The hydrophilic resin photosensitive layer is formed by coating with a photosensitive composition containing a hydrophilic polymer, a crosslinking agent and a light absorbent, and crosslinking it. In this case, the polymer has a functional group, and is partially decomposed by a heat generated by irradiating with the light. The crosslinking agent crosslinks with the polymer to convert the polymer to water insolubility, thereby improving water resistance of the photosensitive layer. The absorbent absorbs a light to generate a heat. Thus, developing and wiping are eliminated, and good sensitivity, resolution and plate wear resistance can be provided. |
