| 摘要 |
PROBLEM TO BE SOLVED: To provide a plate making method of planographic printing plate which performs development within 120 see after an original plate of planographic printing plate which is capable of heat mode recording is subjected to image exposure by means of laser beams and can obtain an original plate of planographic printing plate which causes no deterioration of the development. SOLUTION: The original plate of planographic printing which is provided with a heat sensitive layer which contains a photothermal conversion agent and a binder polymer on a substrate and, further, a hydrophilic layer or lipophobic layer on the heat sensitive layer is subjected to laser exposure in a state of image, thereafter, the development treatment is applied within 120 see, thereby, the hydrophilic layer or the lipophobic layer of laser exposure part is removed and the planographic printing plate is formed. Therein, it is a feature of this plate making method of planographic printing plate that the photothermal conversion agent which is contained in the original plate of planographic printing is an infrared ray absorbing dye. |
