HEAT SENSITIVE PLANOGRAPHIC PRINTING ORIGINAL PLATE

摘要

PROBLEM TO BE SOLVED: To provide a planographic printing original plate for CTP which eliminates the disadvantage of use of a dark room and can be handled in a light room. SOLUTION: The heat sensitive planographic printing original plate has 1) a thermopolymerizable layer containing a polymer having an addition polymerizable unsaturated bond in a side chain and soluble in an aqueous alkali solution and a thermopolymerization initiator and 2) an overcoat layer containing a water-soluble polymer and a photothermal converting agent in this order on a substrate having a hydrophilic surface.