Photosensitive composition and planographic printing plate precursor using same

摘要

Disclosed are a photosensitive composition characterized by high sensitivity and good latitude in development, and a positive-type planographic printing plate precursor that uses the composition in a direct plate production process and enables an image to be formed with high sensitivity with an infrared laser. Namely, the photosensitive composition is disclosed comprising components (a) and (b) as follows and becoming soluble in an aqueous alkaline solution when irradiated with an infrared laser: (a) an infrared-ray absorbing agent represented by formula (I) as follows; and (b) a polymeric compound insoluble in water but soluble in an aqueous alkaline solution