Method for coating substrate with metal oxide coating

Abstract

The method is disclosed for coating or impregnating a substrate with a metal oxide. The method includes the steps of applying a liquid metal carboxylate composition, or a solution thereof, to a substrate material, and exposing the substrate material to an environment that will cause vaporization or dissipation of any excess carboxylic acids in the liquid metal carboxylate composition and conversion of the metal carboxylates to metal oxides.

What is claimed is:  
     
         1 . A method for forming a metal oxide coating on a substrate, comprising the steps of: 
 (a) applying metal carboxylate composition, or a solution thereof, to a substrate material, and    (b) exposing the substrate material to an environment that will cause vaporization or dissipation of any excess carboxylic acids in the liquid metal carboxylate composition and conversion of the metal carboxylates to metal oxides.    
     
     
         2 . The method or  claim 1 , wherein the liquid metal carboxylate composition comprises a solution of the metal salt of a carboxylic acid.  
     
     
         3 . The method of  claim 2 , wherein the carboxylic acid is an alpha-branched carboxylic acid having having the formula 
       R—C(R″)(R′)—COOH 
       wherein: 
 R is selected from H and C 1  to C 24  alkyl groups; and  
 R′ and R″ are each independently selected from C 1  to C 24  alkyl groups.  
 
     
     
         4 . The method of  claim 2 , wherein the carboxylic acid is a mixture of carboxylic acids having the formula CH 3 (CH 2 ) n C(CH 3 )(C 2 H 5 )—COOH, wherein n is 7 to 10.  
     
     
         5 . The method of  claim 4 , wherein the average molecular weight of the acids contained in this mixture is from about 220 to 270.  
     
     
         6 . The method of  claim 5 , wherein the mixture of carboxylic acids contains the acid CH 3 CH 2 CH 2 CH(CH 3 )—COOH as its lowest boiling acid constituent.  
     
     
         7 . The method of  claim 2 , wherein the liquid metal carboxylate composition comprises a mixture of metals.  
     
     
         8 . The method of  claim 2 , wherein the liquid metal carboxylate composition comprises one or more metals selected from the group consisting of Lithium, Beryllium, Sodium, Magnesium, Potassium, Calcium, Scandium, Titanium, Chromium, Manganese, Iron, Nickel, Cobalt, Copper, Zinc, Gallium, Rubidium, Strontium, Yttrium, Zirconium, Silver, Cadmium, Tin, Cesium, Cerium, Barium, Lanthanum, Hafnium, Tantalum, Gold, Thallium, Lead, Bismuth, Cerium, Praseodymium, Neodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Thorium and Uranium.  
     
     
         9 . The method of  claim 3 , wherein the liquid metal carboxylate composition comprises one or more metals selected from the group consisting of Lithium, Beryllium, Sodium, Magnesium, Potassium, Calcium, Scandium, Titanium, Chromium, Manganese, Iron, Nickel, Cobalt, Copper, Zinc, Gallium, Rubidium, Strontium, Yttrium, Zirconium, Silver, Cadmium, Tin, Cesium, Cerium, Barium, Lanthanum, Hafnium, Tantalum, Gold, Thallium, Lead, Bismuth, Cerium, Praseodymium, Neodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Thorium and Uranium.  
     
     
         10 . The method of  claim 4 , wherein the liquid metal carboxylate composition comprises one or more metals selected from the group consisting of Lithium, Beryllium, Sodium, Magnesium, Potassium, Calcium, Scandium, Titanium, Chromium, Manganese, Iron, Nickel, Cobalt, Copper, Zinc, Gallium, Rubidium, Strontium, Yttrium, Zirconium, Silver, Cadmium, Tin, Cesium, Cerium, Barium, Lanthanum, Hafnium, Tantalum, Gold, Thallium, Lead, Bismuth, Cerium, Praseodymium, Neodymium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, Lutetium, Thorium and Uranium.  
     
     
         11 . The method of  claim 2 , wherein the metal is a mixture comprising: 
 up to 15% by weight of cobalt;    up to 20% by weight of nickel; and    the balance iron;    wherein the minimum total amount of cobalt and nickel is at least 3%.    
     
     
         12 . The method of  claim 2 , wherein the metal is a mixture comprising: 
 up to 20% by weight of cobalt;    up to 10% by weight of chromium; and    the balance cerium;    wherein the minimum total amount of cobalt and chromium is at least 3%.    
     
     
         13 . The method of  claim 2 , wherein the metal is a mixture comprising: 
 3 through 5% by weight of cobalt,    0 through 20% by weight of chromium,    and the balance cerium.    
     
     
         14 . The method of  claim 1  wherein the vaporization or dissipation of any excess carboxylic acids in the liquid metal carboxylate composition and conversion of the metal carboxylates to metal oxides is carried out by heating the coated substrate.  
     
     
         15 . The method of  claim 14 , wherein the substrate is heated to a temperature greater than about 400° C.  
     
     
         16 . The method of  claim 2 , wherein the amount of metal in the liquid metal carboxylate composition is preferably in the range of 30-50 grams of metal per kilogram of liquid metal carboxylate composition.  
     
     
         17 . The method of  claim 2 , wherein the amount of metal in the liquid metal carboxylate composition is 30 to 40 grams of metal per kilogram of liquid metal carboxylate composition.