Anode for oxygen generation

Abstract

In an insoluble anode for use in an electrolysis step accompanied by oxygen generation, by making the anode exert sufficient durability even in electrolysis accompanied by cathodic polarization besides anodic polarization, a service life of an electrode is prolonged and works of electrode repair, replacement, and the like are reduced. In order to realize this, an active material supporting member made of a porous metal sheet such as an expanded metal, a punching metal, or a bamboo blind-like or net-shaped metal is bonded to a conductive metal as an electrode structure, to configure an electrode substrate. The electrode substrate is coated, on the side to which the supporting member is bonded, with an electrode active material consisting mainly of iridium oxide. Thus, the anode for oxygen generation, which is highly resistant to a cathodization phenomenon, is obtained.

1 . An anode for oxygen generation exhibiting resistance to a cathodization phenomenon, formed by coating a surface of an electrode substrate with an electrode active material,
 wherein   the electrode substrate is configured by bonding an active material supporting member made of a porous metal sheet to a surface of a conductive metal as an electrode structure, and   the electrode substrate is coated, on a side to which the active material supporting member is bonded, with the electrode active material comprising predominantly iridium oxide.   
     
     
         2 . The anode of  claim 1 , wherein the porous metal sheet is selected from the group consisting of an expanded metal, a punching metal, and a bamboo blind-like or net-shaped metal. 
     
     
         3 . The anode of  claim 1 , wherein the electrode active material is a mixture of metal oxides comprising
 iridium in an amount of 50 to 95 wt % on the metal equivalent basis, and   at least one valve metal in an amount of 5 to 50 wt % on the metal equivalent basis.   
     
     
         4 . The anode of  claim 3 , wherein one valve metal is tantalum, and an amount (wt %) of the iridium on the metal equivalent basis is twice or more the content (wt %) of the tantalum. 
     
     
         5 . The anode of  claim 4 , wherein the metal oxides consist of 70 wt % or more of iridium oxide, on the metal equivalent basis, and tantalum oxide. 
     
     
         6 . An insoluble anode for electroplating, comprising the anode of  claim 1 , wherein a cathodization phenomenon occurs in the insoluble anode. 
     
     
         7 . (canceled) 
     
     
         8 . The anode of  claim 1 , wherein the conductive metal and the porous metal sheet are made of a valve metal. 
     
     
         9 . The anode of  claim 8 , wherein the valve metal is selected from the group consisting of titanium, tantalum, niobium, tungsten, and zirconium. 
     
     
         10 . The anode of  claim 2 , wherein the electrode active material is a mixture of metal oxides comprising
 iridium in an amount of 50 to 95 wt % on a metal equivalent basis, and   at least one valve metal in an amount of 5 to 50 wt % on the metal equivalent basis.   
     
     
         11 . An electroplating process, comprising electroplating a metal with the anode of  claim 1 , wherein the anode is an insoluble anode in which a cathodization phenomenon occurs. 
     
     
         12 . The anode of  claim 2 , wherein the conductive metal and the porous metal sheet are made of a valve metal. 
     
     
         13 . The anode of  claim 3 , wherein the conductive metal and the porous metal sheet are made of a valve metal. 
     
     
         14 . The anode of  claim 4 , wherein the conductive metal and the porous metal sheet are made of a valve metal. 
     
     
         15 . The anode of  claim 5 , wherein the conductive metal and the porous metal sheet are made of a valve metal. 
     
     
         16 . The anode of  claim 6 , wherein the conductive metal and the porous metal sheet are made of a valve metal. 
     
     
         17 . The anode of  claim 12 , wherein the valve metal is selected from the group consisting of titanium, tantalum, niobium, tungsten, and zirconium. 
     
     
         18 . The anode of  claim 13 , wherein the valve metal is selected from the group consisting of titanium, tantalum, niobium, tungsten, and zirconium. 
     
     
         19 . The anode of  claim 14 , wherein the valve metal is selected from the group consisting of titanium, tantalum, niobium, tungsten, and zirconium. 
     
     
         20 . The anode of  claim 15 , wherein the valve metal is selected from the group consisting of titanium, tantalum, niobium, tungsten, and zirconium. 
     
     
         21 . The anode of  claim 16 , wherein the valve metal is selected from the group consisting of titanium, tantalum, niobium, tungsten, and zirconium.