| 摘要 |
PROBLEM TO BE SOLVED: To suppress the occurrence of an insoluble material by the reaction of a polyvalent metal ion in a developing solution with an IR absorber and to carry out stable development over a long period of time. SOLUTION: The alkali developing solution contains a compound having carboxyl and hydroxyl groups capable of coordinating with a polyvalent metal cation of Mg, Al, Ca, Ti, Fe or Ba contained in the developing solution. An original plate for planographic printing with an image forming layer containing an IR absorber is imagewise exposed by irradiation with IR and developed with the alkali developing solution to produce the objective planographic printing plate. |
