Conductive antioxidant paint and graphite electrode

Abstract

There are disclosed a conductive antioxidant paint suitably used as an antioxidant material for a graphite electrode used in arc furnaces such as electric steel-making furnaces, and a graphite electrode coated with the conductive antioxidant paint.

What is claimed is:  
     
         1 . A conductive antioxidant paint comprising a conductive material, an antioxidant material, a polymer emulsion and an inorganic colloid as a binder, and a transition metal; and having a pH value of not more than 9.  
     
     
         2 . A conductive antioxidant paint according to  claim 1 , wherein said antioxidant material is previously oxidized.  
     
     
         3 . A conductive antioxidant paint according to  claim 1 , wherein said antioxidant material is a carbide or nitride of an element selected from the group consisting of B, Si, Ge, Sb, Ti, Sn, Al and Zr, a boron element or a silicon element.  
     
     
         4 . A conductive antioxidant paint according to  claim 1 , wherein said inorganic colloid has an average particle size of not more than 100 nm.  
     
     
         5 . A conductive antioxidant paint according to  claim 1 , wherein said transition metal is at least one element selected from the group consisting of Cr, W, Co, Ti and Ni.  
     
     
         6 . A conductive antioxidant paint comprising a conductive material, an antioxidant material, a polymer emulsion and an inorganic colloid as a binder, and a transition metal, the content of alkali metal and/or alkali earth metal being not more than 20% by weight based on the weight of the antioxidant material.  
     
     
         7 . A conductive antioxidant paint according to  claim 6 , wherein said antioxidant material is previously oxidized.  
     
     
         8 . A conductive antioxidant paint according to  claim 6 , wherein said antioxidant material is a carbide or nitride of an element selected from the group consisting of B, Si, Ge, Sb, Ti, Sn, Al and Zr, a boron element or a silicon element.  
     
     
         9 . A conductive antioxidant paint according to  claim 6 , wherein said inorganic colloid has an average particle size of not more than 100 nm.  
     
     
         10 . A conductive antioxidant paint according to  claim 6 , wherein said transition metal is at least one element selected from the group consisting of Cr, W, Co, Ti and Ni.  
     
     
         11 . A conductive antioxidant paint comprising a conductive material, an antioxidant material and a binder; and having a total content of aluminum and silicon elements of not more than 1% by weight based on the weight of a solid content of the paint.  
     
     
         12 . A conductive antioxidant paint according to  claim 11 , wherein said antioxidant material is previously oxidized.  
     
     
         13 . A conductive antioxidant paint according to  claim 11 , wherein said antioxidant material is a carbide or nitride of an element selected from the group consisting of B, Si, Ge, Sb, Ti, Sn, Al and Zr, a boron element or a silicon element.  
     
     
         14 . A conductive antioxidant paint according to  claim 11 , further comprising an inorganic colloid having an average particle size of not more than 100 nm.  
     
     
         15 . A conductive antioxidant paint according to  claim 11 , further comprising at least one transition metal selected from the group consisting of Cr, W, Co, Ti and Ni.  
     
     
         16 . A graphite electrode coated with the conductive antioxidant paint as defined in claims  1 ,  6  or  11 .