| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive photosensitive composition irresponsive to a light in the ultraviolet region and superior in handleability under a while fluorescent light and high in sensitivity and contrast between image parts and nonimage parts and capable of maintaining a film thickness in image parts and to provide the lithographic printing plate formed by using this composition. SOLUTION: This positive photosensitive composition comprises (A) a photothermo-converting compound absorbing a light from an image exposure light source and converting it into heat, preferably, a near infrared absorptive cyanine dye, (B) a novolak resin, and (C) an alcohol compound boiling at >=150 deg.C in normal pressure, preferably, a polyol, and the lithographic printing plate is formed by coating the surface of a support with this composition and imagewise exposing, and subjected to a proper treatment. |
