Patent ID: 7217489

Claim:
A negative-type planographic printing plate having, disposed on a support, at least a recording layer comprising a radical-polymerizable negative-type image recording material on which an image can be recorded by irradiation with an infrared ray, the radical-polymerizable negative-type image recording material including an infrared ray absorbing agent comprising a cyanine dye in which at least one of substituents on nitrogen atoms at both terminal ends thereof is selected from the group consisting of the following substituents: —C(═X)R 1 ; —C(═X)R 2 R 3 ; —CH═CR 4 R 5 ; —C≡CR 6 ; —CR 9 R 10 R 11 ; and —Ar, wherein X represents O or S; R 1 to R 6 each independently represent H or a hydrocarbon group having 20 or fewer carbon atoms which may have a substituent; R 7 to R 11 each independently represent a hydrocarbon group having 20 or fewer carbon atoms which may have a substituent; Ar represents an aromatic group which may have a substituent; and wherein the radical-polymerizable negative-type image recording material further comprises a radical generating agent and a radical polymerizable compound.