Aluminum foil as electrolytic condenser electrodes.

摘要

An aluminum foil for use as the electrolytic condenser electrodes is composed of 99.9 % or more of aluminum. The fil also contains given amounts of one or more auxiliary elements selected from a group consisting of Cu, Si, Zn, Mn, Ga, P, V, Ti, Cr, Ni, Ta, Zr, C, Be, Pb, In and rare-earth elements, with the auxiliary elements being contained either in a boundary region disposed between a foil body and an oxide layer thereon, or in surface portion of the oxide layer, at a concentrated state such that an ion strength ratio of the concentration of the auxiliary elements in the region or the portion to their concentration in the foil body is from 1.2 : 1 to 30 : 1. Alternatively, the foil may contain given amounts of one or more auxiliary elements selected from a group consisting of Fe, Cu, Si, Zn, Mn, Ga, P, V, Ti, Cr, Ni, Ta, Zr, C, Be, B, Mg, Pb, In, Bi and rare-earth elements, with the auxiliary elements being contained not only in the boundary region but also in the surface portion at the same concentrated state as described above.