Patent ID: 8304171

Claim:
A plate making method of a lithographic printing plate precursor comprising: exposing imagewise a lithographic printing plate precursor comprising a support and an image-forming layer and containing (A) a compound generating an acid with light or heat, (B) an aromatic hydrocarbon compound or heterocyclic compound substituted with a functional group containing a nitrogen atom and (C) a compound represented by the following formula (I): wherein R 1 to R 5 each independently represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, an aryl group, a heteroaryl group, a hydroxy group, an alkoxy group, an aryloxy group, —OCORa, —OCONRaRb, —NRaRb, —N(Ra)CORb, —N(Ra)COORb, —COORa, —CONRaRb, —SRa or a cyano group, each of these groups may contain an atom or atomic group selected from O, S, N(Ra), CO and combinations thereof between an appropriate carbon chain thereof, or at least two of R 1 to R 5 may be combined with each other to form a condensed ring, X 1 and X 2 each independently represents —ORx, —NRxRy or —SRx, plural Rx and Ry may be combined with each other to form a cyclic structure, Ra and Rb each independently represents a hydrogen atom, an alkyl group, an aryl group or a heteroaryl group, and Rx and Ry each independently represents an alkyl group, an aryl group or a heteroaryl group, and removing an unexposed area of the image-forming layer of the lithographic printing plate precursor by supplying at least one of dampening water and ink on a cylinder of a printing machine.