| 摘要 |
PROBLEM TO BE SOLVED: To improve a photothermal conversion efficiency, to form a rigid resin image, to enhance adhesive properties of a support to a resin image portion and to improve a plate wear resistance by incorporating a gradient in a film thickness direction of an image forming layer in a containing ratio of a photothermal conversion substance. SOLUTION: A gradient is set in a film thickness direction to a containing ratio of a photothermal conversion substance in an image forming layer so that an emitted light of an image exposure arrives at the innermost side of the layer. Thus, photothermal conversion is efficiently conducted, thermoplastic resin particles are effectively fusion bonded to form a rigid resin image. In the case that the image forming layer exists on a normally grained aluminum support, the substance in the forming layer is increased at its content ratio in the film thickness direction from an air side to a support interface side so that the conversion is sufficiently uniformly spread in the layer with the result that the image becomes tough and the image at the interface side is rigidly adhered, thereby obtaining the lithographic printing plate having excellent plate wear resistance. |
