The positive type photosensitive composition, positive type photosensitive planographic printing edition and the positive picture formation methodological null below-mentioned

摘要

PROBLEM TO BE SOLVED: To provide a positive photosensitive composition having a wide development latitude as well as high sensitivity to light in the near IR region and stably giving an image excellent in contrast between image and non-image areas with respect to a positive photosensitive composition comprising a photothermal conversion material and an alkali-soluble resin and to provide a positive photosensitive planographic printing plate and a positive image forming method using the same.;SOLUTION: The positive photosensitive composition comprises (A) a photothermal conversion material which absorbs light of a light source for imagewise exposure and converts the light to heat, (B) an alkali-soluble resin and (C) a surfactant, and when the concentration of the component (B) is within the range of 0 to 40 wt.% and the weight ratio of the component (C) to the component (B) is within the range of 0 to 0.25, the positive photosensitive composition has such relation as to produce regions in which both the components are made compatible to form a single phase and regions in which both the components separate into two phases.;COPYRIGHT: (C)2003,JPO