| 摘要 |
PROBLEM TO BE SOLVED: To provide a support for a lithographic printing plate with superb sensitivity. SOLUTION: This method for manufacturing a support for a lithographic printing plate is to first perform at least two processes out of mechanical surface roughening, etching with an alkaline solution containing caustic soda and electrochemical surface roughening in a solution containing at least either of hydrochloric acid or nitric acid, then form 1 g/m2 or more oxide layer by an anodic oxidation process using a liquid containing at least one kind selected from among sulfuric acid, oxalic acid and phosphoric acid, and reduce the surface area of the oxide layer by 30% or more using a pore sealing process. The anodic oxidation process is constituted of two or more steps in which the temperature, conductivity and specific gravity of an electrolyte are fixed under control and the flow rate of the electrolyte is set within the range of 1-250 cm/sec. The current density of the first process is 50% or below of that of the second process, and the micropore density of the anodic oxide layer before the pore sealing process is 100 pcs/μm2 or more, and further, the average diameter of the micropore is 3 nm or more. |
