Aluminum alloy plate for lithographic printing plate, lithographic printing plate support, presensitized plate, method of manufacturing aluminum alloy plate for lithographic printing plate and method of manufacturing lithographic printing plate support

A method of manufacturing a lithographic printing plate support, the method comprising the steps of:

• a semicontinuous casting step for forming an ingot from an aluminum alloy melt containing 0.08 to 0.45 wt % of iron and 0.05 to 0.20 wt % of silicon with the balance being inadvertent impurities and aluminum;
• a scalping step for scalping the ingot formed in the semicontinuous casting step;
• a hot rolling step for rolling the scalped ingot to obtain a rolled plate;
• a cold rolling step for reducing a thickness of the rolled plate following the hot rolling step to obtain an aluminum alloy plate;
• and
• a surface treatment step in which a surface of the aluminum alloy plate following the cold rolling step is subjected to a surface roughening treatment including an electrochemical graining treatment and an anodizing treatment in this order to obtain the lithographic printing plate support,
• wherein a thickness (X) of the ingot following the semicontinuous casting step, a plate thickness (Y) following the cold rolling step, an amount (A) of material removed by the scalping step, an amount (B) of material removed by the surface roughening treatment and a thickness (C) of an anodized film satisfy the following expression (i):
• 4
• ≦
• Z
• =
• X
• -
• A
• Y
• ×
• (
• B
• +
• C
• )
• ×
• 10
• -
• 3
• +
• A
• ≦
• 20.
• (
• i
• )