PHOTO-POLYMERIZATION COMPOSITION AND PHOTOSENSITIVE LITHOGRAPHIC PRINTING PLATE

摘要

PURPOSE: To provide a photo-polymerization composition and a photosensitive lithographic printing plate shortening the gradation without reducing the sensitivity of the photo-polymerization composition and having high dot image quality and a good safe light property. CONSTITUTION: This photo-polymerization composition contains a polymerizable compound having addition polymerization unsaturated bond, a photo-polymerization initiator, an alkali-soluble polymer compound, and a compound reacted via an exposure to change the absorption spectrum in the region from ultraviolet light to visible light and not changing the solubility in a developer via an exposure. A photosensitive lithographic plate has the photo-polymerization composition layer containing the polymerizable compound having addition polymerization unsaturated bond, the photo-polymerization initiator, and the alkali-soluble polymer compound and an overcoat layer on a base. The overcoat layer contains the compound reacted via an exposure to change the absorption spectrum in the region from ultraviolet light to visible light and not changing the solubility in a developer via an exposure.