| 摘要 |
PURPOSE:To obtain an aluminum alloy plate not losing excellent capacity as a printing plate and hard to thermally soften, by performing intermediate annealing so that the electric resistance value of a rolled plate satisfies a specific condition. CONSTITUTION:Intermediate annealing is performed so that the value, which is obtained by subtracting an electric resistance value after heating at 380 deg.C for 6hr and a correction value corresponding to contribution by processing hardening from the electric resistance value of a rolled plate after final cold rolling, is 0.01OMEGA.cm or more. This aluminum alloy is prepared by using Al being a metal with purity of 99.50wt% and the impurities contained in the metal desirably consists of 0.40wt% or less of iron and 0.20wt% or less of silicon. The content of zirconium of the aluminum alloy is set to 0.02-0.20wt% and, if below 0.02%, the improving effect of a heat softening characteristic is insufficient and, if exceeds 0.20wt%, the heat softening characteristic is improved still more but the crystal structure of the aluminum alloy plate becomes non-uniform and the printability thereof is lowered. |
