| abstract |
An imaging member, such as a negative-working printing plate,ncan be prepared using a hydrophilic imaging layer comprised of a heat-sensitivenhydrophilic polymer having a positively charged moiety, and optionally anphotothermal conversion material. The heat-sensitive polymer has recurring unitsncontaining an N-alkylated aromatic heterocyclic group or an organoonium groupnthat reacts to provide increased oleophilicity in areas exposed to energy thatnprovides or generates heat. For example, heat can be supplied by laser irradiationnin the IR region of the electromagnetic spectrum. Thus, the heat-sensitivenpolymer is considered "switchable" in response to heat, and provides an imagingnmeans without wet processing. |