Electrolytic electrode and process of producing the same
View Patent ↗An electrolytic electrode having an interlayer having more excellent peeling resistance and corrosion resistance and longer electrolytic life than conventional electrolytic electrodes and capable of flowing a large amount of current at the industrial level and a process of producing the same are provided. The electrolytic electrode includes a valve metal or valve metal alloy electrode substrate on the surface of which is formed a high-temperature oxidation film by oxidation, and which is coated with an electrode catalyst. The high-temperature oxidation film is integrated with the electrode substrate, whereby peeling resistance is enhanced. Further, by heating the high-temperature oxidation film together with the electrode catalyst, non-electron conductivity of the interlayer is modified, thereby making it possible to flow a large amount of current.
1. An electrolytic electrode comprising:
a valve metal or valve metal alloy electrode substrate,
a high-temperature oxidation film having a rutile structure formed from the substrate itself on the surface of the valve metal or valve metal alloy electrode by high-temperature oxidation treatment such that an increase of weight is 0.67 g/m 2 to 17 g/m 2 , the high-temperature oxidation film and underlying substrate assuming an oxygen concentration gradient in a depth direction, and
an electrode catalyst layer formed on the surface of the high-temperature oxidation film.
2. The electrolytic electrode as claimed in claim 1 , wherein the increase of weight is 0.67 g/m 2 or more.
3. The electrolytic electrode as claimed in claim 1 , wherein within the structure having an oxygen concentration gradient, the oxygen concentration is highest in an outermost surface layer portion of the high-temperature oxidation film.
4. The electrolytic electrode as claimed in claim 1 , wherein the high-temperature oxidation film is formed by heating at a temperature of at least 600° C. in an oxidizing atmosphere.
5. The electrolytic electrode as claimed in claim 1 , wherein the valve metal comprises Ti and the high-temperature oxidation film comprises TiO 2 having a rutile structure.
6. A process of producing an electrolytic electrode comprising:
forming a high-temperature oxidation film having a rutile structure on the surface of a valve metal or valve metal alloy substrate, said high-temperature oxidation film being formed by high-temperature oxidation treatment and from the substrate itself such that its increase of weight is 0.67 g/m 2 to 17 g/m 2 , the high-temperature oxidation film and underlying substrate assuming an oxygen concentration gradient in a depth direction, and
forming an electrode catalyst layer on the high-temperature oxidation film.
7. The process as claimed in claim 6 , wherein in providing an electrode catalyst layer on the high-temperature oxidation film, the electrode catalyst layer is formed by the coating thermal decomposition method.
8. The process as claimed in claim 6 , wherein within the structure having an oxygen concentration gradient, the oxygen concentration is highest in an outermost surface layer portion of the high-temperature oxidation film.
9. The process as claimed in claim 6 , wherein the valve metal comprises Ti and the high-temperature oxidation film comprises TiO 2 having a rutile structure.
10. A process of producing an electrolytic electrode comprising:
forming a high-temperature oxidation film on the surface of a valve metal or valve metal alloy electrode by high-temperature oxidation treatment, and
forming an electrode catalyst layer on the high-temperature oxidation film, wherein in forming the high-temperature oxidation film, an increase of weight of the high-temperature oxidation film is at least an increase of weight of a high-temperature oxidation film of a valve metal or valve metal alloy electrode substrate formed at a heating temperature of 600° C. for a holding time of one hour in air.
11. The process as claimed in claim 10 , wherein in providing an electrode catalyst layer on the high-temperature oxidation film, the electrode catalyst layer is formed by the coating thermal decomposition method.