The present application relates to a positive-working heat-sensitive lithographic plate. The infrared heat-sensitive image recording composition of the plate comprises a resin having self-dissolution inhibiting property and an infrared absorber. The resin having self-dissolution inhibiting property is an alkali-soluble resin that contains phenolic hydroxyl group, and carbamate or thiocarbamate group that has strong electron-absorbing ability. The advantage of the present application is that it requires no dissolution inhibitor when preparing the infrared positive-working heat-sensitive CTP plate. The mechanism could be understood but not limited to that the carbamate or thiocarbamate group contained in the resin has a dissolution inhibiting effect on the phenolic hydroxyl group in the resin, reducing the solubility of the resin in an alkali solution.
Li, Shiyou and Yuan, Wei, "Thermosensitive Imaging Composition and Lithographic Plate Comprising the Same (US Patent 20110271859)" (2011). NCPC Publications and Patents. 9.