Aluminum support for planographic printing plate, its manufacturing process, and planographic printing plate material

摘要

Disclosed is an aluminum support for a planographic printing plate comprising an electrolytically surface-roughened aluminum plate, and a sulfuric acid anodization layer and a phosphoric acid anodization layer provided in that order on the surface-roughened surface of the surface-roughened aluminum plate, the sulfuric acid anodization layer having micro-pores with a pore size of from 8 to 15 nm and the phosphoric acid anodization layer having micro-pores with a pore size of from 40 to 100 nm, wherein the sulfuric acid anodization layer has been formed by anodizing the aluminum plate in a sulfuric acid electrolytic solution and the phosphoric acid anodization layer has been formed by anodizing the aluminum plate in a phosphoric acid electrolytic solution.