TWO-LAYER ANODIZING ALUMINUM SUPPORTER, MANUFACTURE AND LITH PRINTING PLATE WITH SAID SUPPORTER

摘要

PURPOSE: To improve a resistance to staining while holding good adhesive properties by existing a bilayered anode formed on an aluminum support having a specific thickness present in a predetermined coverage of an aluminum oxide and phosphate on a surface, and incorporating pores of a specific size in diameter at upper and lower layers. CONSTITUTION: A bilayered anode surface is formed at least on one surface of an aluminum plate of a support material. The bilayered anode surface is formed substantially of an oxide of an aluminum and a phosphate, and its total mean thickness is at least 0.10μm. And an oxide of an aluminum and a phosphate are existed with a total coverage of 100 mg or more per 1m<2> of the support. The support has a bilayered anode surface having the upper and lower layers. The upper layer has pores of a mean pore size of 1.0×10<-8> to 7.5×10<-8> m. The pores of the lower layer are substantially larger in the mean pore size than that of the pores of the upper layer. The lithographic printing plate has a radiation sensitive layer and its support, and the support exhibits a good adhesive properties and improves a resistance to staining of non-image of the printing plate.