| 摘要 |
PROBLEM TO BE SOLVED: To provide a color developing photosensitive composition exhibiting high color development and low decoloration after the color development by an infrared laser exposure, to provide lithographic printing original plate having the composition as an image recording layer and good storage stability, high plate inspectability, printing durability and no image development process, and to provide an engraving method using the lithographic printing original plate.SOLUTION: A color developing composition contains a compound (A) represented by general formula (1), a sensitizer (B), and a binder (C), where Ar, Arand Arare each an aryl group, Arand Arare each independently a phenyl group or a naphthyl group having an amino group at 4-position, Ris a hydrogen atom, an alkyl group or an aryl group, Arand Ar, or Arand Rmay bind each other via an oxygen atom, a nitrogen atom or a sulfur atom to form a ring structure when Ris an aryl group, and Xis a cation. |
