| abstract |
An aluminum alloy support material for a lithographic printing plate which consists essentially, on a weight basis, of 0.5-2.0 % Mn, 0.05-1.0 % Si, 0.15-1.0 % Fe, 0-0.10 % Ti, and a balance of Al and inevitable impurities. The support material has a specific resistance satisfying the following inequality: Specific resistance ( mu OMEGA mm)</=14+16[% Ti] as measured in liquid nitrogen at 77 K, and a particular size distribution of precipitates therein. The support is produced from an ingot of an aluminum alloy having the above composition by homogenizing, hot rolling, cold rolling, intermediate annealing, and finish cold rolling under specific conditions followed by electrochemical graining. The support has fine, uniform pits formed by electrochemical graining and improved strength and printability. |