Surface preparation agent and surface preparation method

Abstract

An agent suitable for use in preparing metal surfaces, especially surfaces containing aluminum, is provided which contains at least one water-soluble vanadium compound, at least one titanium-containing or zirconium-containing water-soluble complex fluoride, and at least one resin. The agent is capable of forming a strongly rust preventive base coating that is highly adherent for top coats and bonded films.

What is claimed is:  
     
         1 . A surface preparation agent comprising: 
 (A) at least one water-soluble vanadium compound;    (B) at least one water-soluble complex fluoride selected from the group consisting of titanium-containing water-soluble complex fluorides and zirconium-containing water-soluble complex fluorides; and    (C) at least one resin.    
     
     
         2 . The surface preparation agent of  claim 1  wherein at least one water-soluble vanadium compound is a compound that generates water-soluble vanadium-containing ions in the presence of water.  
     
     
         3 . The surface preparation agent of  claim 1  or  2 , wherein at least one water-soluble vanadium compound is selected from the group consisting of metavanadic acid, salts of metavanadic acid, vanadium halides, vanadyl sulfate, vanadium nitrate, vanadium phosphate, vanadium biphosphate, vanadium acetate and organovanadium compounds.  
     
     
         4 . The surface preparation agent of  claim 1 ,  2  or  3  wherein at least one water-soluble complex fluoride is a compound capable of releasing protons in the presence of water.  
     
     
         5 . The surface preparation agent of  claim 1 ,  2 ,  3  or  4  wherein at least one water-soluble complex fluoride is a compound capable of generating hydrofluoric acid in the presence of water.  
     
     
         6 . The surface preparation agent of  claim 1 ,  2 ,  3 ,  4  or  5  wherein at least one water-soluble complex fluoride is selected from the group consisting of fluozironic acid, salts of fluozirconic acid, fluotitanic acid, and salts of fluotitanic acid.  
     
     
         7 . The surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 , or  6  having a V: (Zr+Ti) weight ratio in a range of from 1:5000 to 5000:1.  
     
     
         8 . The surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 ,  6 , or  7  having a {V+(Zr+Ti)}: resin weight ratio in a range of 10:1 to 1:100.  
     
     
         9 . The surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  or  8  wherein at least one resin is soluble or dispersible in water.  
     
     
         10 . The surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7  or  8  wherein at least one resin is a resin which is soluble in water but loses water solubility when said surface preparation agent is dried.  
     
     
         11 . The surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9  or  10  wherein at least one resin is selected from the group consisting of polyacrylic acids, polyacrylamides, polyamides, polyurethanes, polyesters, phenolic resins and epoxy resins.  
     
     
         12 . A metal sheet having on at least one surface a coating comprised of the surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 ,  10  or  11 .  
     
     
         13 . The metal sheet of  claim 12  wherein said metal sheet is comprised of aluminum.  
     
     
         14 . The metal sheet of  claim 12  wherein the total amount of V+Zr+Ti in said coating is from 0.05 to 100 mg/m 2 .  
     
     
         15 . A method of preparing a metal surface, said method comprising applying the surface preparation agent of  claim 1 ,  2 ,  3 ,  4 ,  5 ,  6 ,  7 ,  8 ,  9 ,  10  or  11  to said metal surface to form a coating.  
     
     
         16 . The method of  claim 15  wherein the total amount of V+Zr+Ti in said coating is from 0.05 to 100 mg/m 2 .  
     
     
         17 . The method of  claim 15  wherein said surface preparation agent additionally comprises water and said method comprises an additional step of drying the coating.  
     
     
         18 . The method of  claim 17  wherein said drying is carried out at a temperature of 150° C. to 250° C.  
     
     
         19 . The method of  claim 15  or  16  wherein said metal surface is comprised of aluminum.