| 摘要 |
PROBLEM TO BE SOLVED: To provide a positive-working original plate for a printing plate for an infrared laser and for so-called direct plate making capable of improving film strength and reduction in film thickness while retaining sensitivity and capable of direct plate making particularly from digital signals of a computer or the like. SOLUTION: The positive-working original plate for a printing plate is obtained by disposing on a support a positive image recording layer comprising a water-insoluble and alkali-soluble resin and an IR absorbent and having solubility in an alkaline aqueous solution increased by exposure with infrared laser light, and the positive image recording layer further contains at least one of the compounds of formula (I) and (II) (where R1 -R9 are each H, alkyl, alkenyl, aryl or allyl each of which may have a substituent, or halogen). |
