| 摘要 |
Provided are: a lithographic printing original plate which has an image recording layer that contains (A) a cyanine dye represented by general formula (1), (B) a binder polymer and (C) a polymerizable monomer on a supporting body, and which provides a lithographic printing plate having excellent printing durability; and a plate making method using this lithographic printing original plate. Also provided are: a lithographic printing original plate which provides a lithographic printing plate that has excellent on-press developability and is capable of forming a color image that has good visibility even after long-term storage, while having excellent printing durability; and a plate making method using this lithographic printing original plate. In general formula (1), each of R1 and R8 independently represents a hydrocarbon group; each of R2, R3, R4, R5, R6 and R7 independently represents a hydrogen atom or a hydrocarbon group, and R4 and R5 may combine together to form a ring; each of Q1 and Q2 independently represents -NR0-, S, O, -CH=CH- or a dialkyl methylene group; R0 represents a hydrogen atom or a hydrocarbon group; each of T1 and T2 independently represents an atomic group necessary for forming an aromatic ring or a heteroaromatic ring; each of A- and B- independently represents a counter ion selected from among a halide ion, a perchlorate ion, a tetraphenyl borate ion, a tetrafluoroborate ion, a hexafluorophosphate ion and a sulfonate ion; and each of R9-R22 independently represents a hydrogen atom, a halogen atom or a monovalent organic group, provided that at least two of the R13-R22 moieties are electron-withdrawing groups selected from among a chlorine atom, a fluorine atom and a trifluoromethyl group and at least two of the R9-R12 moieties are hydrocarbon groups. |
