| 摘要 |
PROBLEM TO BE SOLVED: To prevent the dissolution of an anodically oxidized film in a developing process so as to avoid whitening in a nonpicture part, to decrease or eliminate contamination caused when a plate is neglected or caused after erasing, and to obtain excellent printing durability by using an aluminum base body treated with a soln. containing sugar. SOLUTION: The base body is an aluminum plate which is subjected to roughening treatment and anodic oxidation treatment and then to treatment with a soln. containing sugar. If the plate is not treated with a soln. containing sugar, whitening occurs in a nonpicture part where a photosensitive layer exposed to light is removed by development, and moreover, the anodic oxidation film dissolved by the developer accumulates in the developer to produce sludge or contaminant. This causes deterioration in the cleaning property of an automatic developing machine, clogging in a spray. Further, the pore diameter of the anodically oxidized film increases and an ink is hardly removed during printing, which accelerates contamination of the neglected plate. |
