| 摘要 |
PROBLEM TO BE SOLVED: To directly make a plate from digital data of a computer or the like, by an infrared laser, increase the sensitivity, and prevent fouling from occurring by a method wherein on a hydrophilic supporting body, a photo-sensitive layer containing an infrared ray absorbing agent having a hydrophobic functional group which changes to hydrophilic by heat, is provided. SOLUTION: In a photo-sensitive layer on a hydrophilic supporting body, an infrared ray absorbing agent containing a hydrophobic functional group which changes to hydrophilic by heat, especially, a sulfonate, is contained, and thus, after a light-heat conversion, the infrared ray absorbing agent itself decomposes and changes from hydrophobic to hydrophilic, and is dissolved into wetting water at the time of a printing. Therefore, the infrared ray absorbing agent is prevented from remaining as a residual film on an exposed part, and also, is prevented from becoming the cause for fouling. by becoming a foreign matter-form solid phase during a wetting. The plate making can be directly performed from digital data of a computer or the like by an infrared laser, and the sensitivity is high, fouling is prevented from occurring, and a high practicality is provided. |
