PHOTOSENSITIVE COMPOSITION AND PHOTOSENSITIVE PLANOGRAPHIC PRINTING PLATE

摘要

PROBLEM TO BE SOLVED: To obtain a photosensitive composition having high sensitivity to light in the near IR region by incorporating a near IR absorbing dye having a structure in which an atom other than carbon has been bonded by way of a polymethine chain having an iminium salt group as a substituent. SOLUTION: The photosensitive composition contains a near IR absorbing dye having a structure in which an atom other than carbon has been bonded by way of a polymethine chain having an iminium salt group as a substituent. The near IR absorbing dye has an absorption band in a part or the whole of the near IR region of 700-1,300 nm wavelength and efficiently absorbs light in the region but hardly absorbs light in the UV region or does not substantially respond even if it absorbs the light. The near IR absorbing dye does not modify the photosensitive composition under such weak UV as UV contained in a while light.