Abstract:
PROBLEM TO BE SOLVED: To provide a negative photosensitive composition and a negative photosensitive planographic printing plate in which the latitude for preheating can be widened without increasing ablation during exposure. SOLUTION: The negative photosensitive composition contains (a) an alkali- soluble resin, (b) a compound which crosslinks by an acid, (c) a compound which produces an acid by heat, (d) a photo-thermal converting agent and (e) a sulfone compound expressed by general formula (I): R-SO2 -R'. The negative photosensitive lithographic printing plate has a photosensitive layer made of the above photosensitive composition. In formula (I), R and R' is same or different and each represents a substituted or unsubstituted alkyl group, alkenyl group, aryl group or heterocyclic group.
Abstract:
A negative-working photosensitive composition comprises (a) an alkali-soluble resin, (b) a compound which causes a crosslinking reaction by an acid, (c) a compound which generates an acid by heating, and (d) a photothermal converting agent, wherein the compound (c) which generates an acid by heating described above is an onium salt of an acidic dye having a sulfonic group in a molecule. A negative-working photosensitive planographic printing plate is provided with a photosensitive layer comprising the negative-working photosensitive composition, on a surface of a support.