NEGATIVE PHOTOSENSITIVE COMPOSITION AND NEGATIVE PHOTOSENSITIVE LITHOGRAPHIC PRINTING PLATE

摘要

A negative photosensitive composition which comprises (A) an infrared ray absorber, (B) an organic boron compound exhibiting the function as a polymerization initiator by the combination with the infrared ray absorber (A), (C) an onium salt, and (D) a compound having a polymerizable unsaturated group. The use of the above negative photosensitive composition allows the preparation of a negative photosensitive composition which can be cured by an infrared ray, is less susceptible to the inhibition of polymerization due to oxygen in the radical polymerization thereof, and is excellent in storage stability, and also allows the production of a negative photosensitive lithographic printing plate which can directly form an image without preheating by the irradiation of an infrared ray from a solid laser or a semiconductor laser based on a digital signal, exhibits high sensitivity and is excellent in the resistance to printing and in storage stability.