INFRARED-SENSITIVE CHROMOGENIC COMPOSITION, INFRARED-CURABLE CHROMOGENIC COMPOSITION, LITHOGRAPHIC PRINTING PLATE PRECURSOR, AND PLATE FORMATION METHOD

摘要

A light-sensitive color-forming composition and a curable color-forming composition each of which forms color at a high density by exposure with an infrared laser and has a small fading due to aging is provided by an infrared sensitive color-forming composition containing (A) a compound having an infrared absorbing skeleton and a thermochromic skeleton in its molecule wherein the infrared absorbing skeleton and the thermochromic skeleton are connected with a covalent bond or an ionic bond, and (B) a binder, and an infrared curable color-forming composition in which the infrared sensitive color-forming composition described above further contains (C) a radical initiator and (D) a polymerizable compound. A lithographic printing plate precursor which has the curable color-forming composition described above in the image-recording layer, is extremely excellent in the plate inspection property, has good preservation stability and maintains a high color-forming property, is excellent in the on-press development property, and provides a lithographic printing plate having a good printing durability and a plate making method of producing a lithographic printing plate precursor using the lithographic printing plate precursor described above are provided by a lithographic printing plate precursor having an image-recording layer comprising the infrared curable color-forming composition described above and a plate making method of producing a lithographic printing plate precursor by image exposing the lithographic printing plate precursor described above with infrared ray and then performing on-press development.