Patent ID: 6387198
Filing Date: 2002-05-14
Classification: B41N,C22C,C22F

Abstract:
A process for producing an aluminum alloy substrate for a lithographic printing plate, consisting essentially of the steps of:preparing an aluminum alloy ingot comprising 0.10 to 0.40 wt % of Fe, 0.03 to 0.30 wt % of Si, 0.004 to 0.050 wt % of Cu, 0.01 to 0.05 wt % of Ti, 0.0001 to 0.02 wt % of B and the balance of Al and unavoidable impurities, homogenizing the ingot at a temperature of 350 to 450Â° C., subsequently hot-rolling the ingot in a plurality of passes to form a hot-rolled plate in such a manner that the aluminum alloy is not recrystallized prior to a final pass of said plurality of passes and is recrystallized at least in a surface layer of the hot-rolled plate only in the final pass to form a recrystallized structure having an average recrystallized grain size of less than 50 &mgr;m in a direction normal to the rolling direction, wherein a reduction in said hot rolling of the final pass is at least 55%, and cold-rolling the hot-rolled plate, said recrystallized structure having a maximum recrystallized grain size of less than 100 &mgr;m in a direction normal to the rolling direction.