Patent ID: 8206573

Claim:
A method for producing an aqueous solution of a quaternary ammonium hydroxide which comprises the steps of: synthesizing a quaternary ammonium inorganic acid salt by the reaction of a trialkylamine with a dialkyl carbonate; and electrolyzing the inorganic acid salt in an electrolytic cell partitioned by a cation exchange membrane with the use of an electrode for electrolysis, wherein the electrode comprises: an electrode base material of an electrically conductive metal of a metal selected from the group consisting of Ti, Ta, Nb and Zr or an alloy of at least one metal selected from the group consisting of Ti, Ta, Nb and Zr; an electrode active layer of a mixed oxide of an oxide of Sn and an oxide of at least one metal selected from the group consisting of In and Ir covering the electrode base material; and an intermediate layer of a mixed oxide of an oxide of Sn and an oxide of at least one metal selected from the group consisting of In and Ir disposed between the electrode base material and the electrode active layer, wherein a content of Sn in the mixed oxide forming the electrode active layer is 50-80% by weight, a content of Sn in the mixed oxide forming the intermediate layer is 50-80% by weight, and the mixed oxide of the intermediate layer further contains an oxide of at least one metal selected from the group consisting of Ti, Ta and Nb, and the mixed oxide of the electrode active layer does not contain essentially an oxide of an oxide of the electrically conductive metal.