| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for making a heat-mode negative lithographic printing plate which can be made easily without the necessity of development and also can be made by fitting directly to a press, is excellent in printing resistance, reduces printing fouling on a printing surface, can be made easily by a scanning type image exposure method by laser beams, is excellent in discriminating an image part and a non-image part, and can be used repeatedly. SOLUTION: In a method for making a negative non-treated printing plate for lithographic printing, an original plate for lithographic printing having a metal oxide layer in which a surface supporting fine photothermal-convertible particles is hydrophilic and has photocatalytic properties on a support is irradiated with heat-mode imagelike light, and the polarity of the metal oxide layer is changed to form an imagelike hydrophobic area. In a method for reusing an original printing plate, the use printing plate is irradiated with active light or heated at a high temperature hydrophilicity development temperature. |
