錫陽極の不働態化に關する研究 (III)

抄録

The passivity of the impure tin anodes were studied. Each one of Pb, Cu, Bi, or Sb is added to the anode in amount of about 0.5, 5.0, and 10% as impurity. The electrolytes used are H₂SO₄, H₂SiFG, and their mixtures. The effect of impurity on the passivation of tin anode differs so greatly with its kind with the change of composition of electrolyte that it is impossible to express in one word.
As a rule, the passifying tendency increases with the amount of impurity, except the case of Bi, which shows no effect in H₂SO₄ and max. passifying tendency by its content of 5% in the other kinds of electrolytes.
As a particular case in Pb, its presence in amount of 5% is exceptionally harmful in the electrolyte of SO₄=0.5 n, SiF₆=1.5 n, Sn⁺⁺0.5 n. Passifying tendency decreases generally with the increasing proportion of SiF₆.