Patent ID: 7341815
Filing Date: 2008-03-11
Classification: B41C,C09B

Abstract:
1. A photosensitive planographic printing plate precursor comprising a support having successively disposed thereon a lower thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound, and an upper thermosensitive layer containing a water-insoluble but alkali-soluble polymer compound, with solubility in an aqueous alkali solution increasing under heat, wherein at least one of the upper thermosensitive layer and the lower thermosensitive layer contains an IR absorbent having, in one molecule, at least two chromophoric groups that absorb IR light, with the chromophoric groups in the IR absorbent bonding to each other via a covalent bond and in which the IR absorbent is represented by the following general formula (I): wherein A represents a divalent or more polyvalent organic group; n indicates an integer of 2 or more; D represents at least one chromophoric group having an absorption in infrared ray range; two or more chromophoric groups may be the same or different, and when the chromophoric group has a charged partial structure, it may have an ionic group charged oppositely to the charge of the chromophoric group so as to neutralize the charge of the chromophoric group.