| 摘要 |
PURPOSE:To obtain a positive type hotosensitive lithographic printing plate assuming no halftone red during development, leaving no stain after erasure and having high sensitivity by forming a photosensitive layer contg. specified compounds on a support. CONSTITUTION:A photosensitive layer of a photosensitive composition contg. a compound producing an acid by exposure and a compound having one or more imino groups (-C-C=N-C-) which are decomposed by the acid is formed on a support. When an alkali-soluble resin such as cresol-formaldehyde resin or phenol-cresol-formamide resin is used in the photosensitive composition, the chemical resistance and solubility of the composition are improved. the preferred amount of the resin used is 30-90wt%, especially 50-85wt% of the total amount of the solid substances in the composition. A sensitizer for enhancing the acid producing effect, a print-out material, a surfactant contg. fluorine and a plasticizer may be added to the photosensitive composition. |
