| 摘要 |
PURPOSE:To prevent the degeneration of the surface of an aluminum substrate body effected an anodic oxidation, and to processing a negative and a positive type lithographic printing plate favorably by processing it at a high pH range using the developing solution having a specific composition. CONSTITUTION:The composition of the developing solution contains a compd. soluble to water or an alkaline solution which comprises the alkaline agent, a sulfite and at least one kind of an element selected from the element belonging to the group IIa, IIIa and IIIb elements. The negative and positive type photosensitive lithographic printing plate formed an image forming layer on the aluminum substrate effected the anodic oxidation is processed at pH11.5-14.0 using the prescribed developing solution. As the alkaline agent, one may use the inorg. alkaline agent such as sodium silicate and ammonium carbonate and an org.alkaline agent such as a tetraalkylammonium hydroxide and an org. ammonium silicate. As the sulfite, one may use the alkaline metal salt and a mag alkaline earth metal salt. As the elements belonging to the groups IIa, IIIa and IIIb elements of the periodic table, calcium, strontium, barium or boron are preferable. |
