| 摘要 |
The present invention provides a photosensitive composition for an infrared laser used for direct plate making, which has high sensitivity and good developing latitude and storage stability, and provides a planographic printing plate in which this composition is used. The positive-type photosensitive composition of the present invention has (a) a macromolecular compound having alkali-soluble groups and (b) a compound that has a phthalocyanine skeleton and has in its molecule at least one group which can form a bond by interaction with an alkali-soluble group in the macromolecular compound (a), or an infrared absorbent expressed by the following General Formula 2, wherein alkali aqueous solution solubility is suppressed prior to infrared irradiation, but Äsaid photosensitive compositionÜ becomes soluble in an alkali aqueous solution upon infrared irradiation. <CHEM> In General Formula 2, X and Y are each an oxygen atom, sulfur atom, selenium atom, or tellurium atom. M is a methine chain with at least five conjugated carbons. Rx1 to Rx4 and Ry1 to Ry4 may be the same or different and are each a hydrogen atom, halogen atom, cyano group, alkyl group, aryl group, alkenyl group, alkynyl group, carbonyl group, thio group, sulfonyl group, sulfinyl group, oxy group, or amino group. W<-> is an anion. |
