Method For Depositing Anti-Corrosive Coating Onto Metal Surface

Abstract

The invention provides a method for depositing a stable anti-corrosive metal oxide and/or metal hydroxide layer onto a metal surface. The invention further provides a stable anti-corrosive coating layer on a metal object, which layer comprises metal oxide and/or metal hydroxide.

1 . A method for depositing a stable anti-corrosive metal oxide and/or metal hydroxide layer onto a metal surface comprising the step of: 
 contacting said metal surface with a mixture comprising: 
 an organic amine;  
 a phosphoric acid and/or an inorganic phosphate; and  
 a metal oxide and/or a metal hydroxide,  
   thereby depositing said metal oxide and/or said metal hydroxide layer onto said metal surface.    
     
     
         2 . The method according to  claim 1 , wherein said organic amine and said phosphoric acid and/or said inorganic phosphate react to form an organic phosphate.  
     
     
         3 . The method according to  claim 2 , wherein said organic phosphate reacts with said metal oxide and/or said metal hydroxide to form oxiaminophosphate.  
     
     
         4 . The method according to  claim 1 , wherein said organic amine is a quaternary amine.  
     
     
         5 . The method according to  claim 1 , wherein said organic amine is morpholine, dicyclohexylamine, ethanolamine, an aliphatic amine, an aromatic amine, melamine, hexamethylentetramine, pentamethylentetramine or any combination thereof.  
     
     
         6 . The method according to  claim 5 , wherein said ethanolamine is a mono, di or tri ethanolamine or any combination thereof.  
     
     
         7 . The method according to  claim 1 , wherein said metal oxide and/or said metal hydroxide is formed in solution by adding a base to a metal salt solution.  
     
     
         8 . The method according to  claim 1 , wherein said metal of said metal oxide and/or said metal hydroxide is magnesium, calcium, iron, zinc, molybdenum, aluminum or any combination thereof.  
     
     
         9 . The method according to  claim 8 , wherein said metal is magnesium.  
     
     
         10 . The method according to  claim 1 , wherein said metal oxide is MgO.  
     
     
         11 . The method according to  claim 1 , wherein said metal hydroxide is Mg(OH) 2 .  
     
     
         12 . The method according to  claim 1 , wherein said mixture is a solution, emulsion suspension or slurry.  
     
     
         13 . The method according to  claim 12 , wherein said mixture is an aqueous mixture.  
     
     
         14 . The method according to  claim 1 , wherein the thickness of said layer is between 1-100 nm.  
     
     
         15 . The method according to  claim 1 , wherein the thickness of said layer is between 5-60 nm.  
     
     
         16 . The method according to  claim 1 , wherein said metal surface comprises iron, magnesium, aluminum or any combination thereof.  
     
     
         17 . The method according to  claim 1 , wherein said mixture further comprising surface active agent, anti-corrosive agents, bactericides, colorants, or a combination thereof.  
     
     
         18 . A stable anti-corrosive coating layer on a metal object, which layer comprises metal oxide and/or metal hydroxide whereby said layer is obtained by contacting the surface of said object with a mixture comprising: 
 an organic amine;    a phosphoric acid and/or an inorganic phosphate; and    a metal oxide and/or a metal hydroxide.    
     
     
         19 . The coating according to  claim 18 , wherein said organic amine and said phosphoric acid and/or said inorganic phosphate react to form an organic phosphate.  
     
     
         20 . The coating according to  claim 19 , wherein said organic phosphate reacts with said metal oxide and/or said metal hydroxide to form oxiaminophosphate.  
     
     
         21 . The coating according to  claim 18 , wherein said organic amine is a quaternary amine.  
     
     
         22 . The coating according to  claim 18 , wherein said organic amine is morpholine, dicyclohexylamine, ethanolamine, an aliphatic amine, an aromatic amine, melamine, hexamethylentetramine, pentamethylentetramine or any combination thereof.  
     
     
         23 . The method according to  claim 22 , wherein said ethanolamine is a mono, di or tri ethanolamine or any combination thereof.  
     
     
         24 . The coating according to  claim 18 , wherein said metal oxide and/or said metal hydroxide is formed in solution by adding a base to a metal salt solution.  
     
     
         25 . The coating according to  claim 18 , wherein said metal of said metal oxide and/or said metal hydroxide is magnesium, calcium, iron, zinc, molybdenum, aluminum or any combination thereof.  
     
     
         26 . The coating according to  claim 25 , wherein said metal is magnesium.  
     
     
         27 . The coating according to  claim 18 , wherein said metal oxide is MgO.  
     
     
         28 . The coating according to  claim 18 , wherein said metal hydroxide is Mg(OH) 2 .  
     
     
         29 . The coating according to  claim 18 , wherein said mixture is a solution, emulsion suspension or slurry.  
     
     
         30 . The coating according to  claim 29 , wherein said mixture is an aqueous mixture.  
     
     
         31 . The coating according to  claim 18 , wherein the thickness of said layer is between 1-100 nm.  
     
     
         32 . The coating according to  claim 18 , wherein the thickness of said layer is between 5-60 nm.  
     
     
         33 . The coating according to  claim 18 , wherein said metal object comprises iron, magnesium, aluminum or any combination thereof.  
     
     
         34 . The coating according to  claim 18 , wherein said mixture further comprising surface active agent, anti-corrosive agents, bactericides, colorants, or a combination thereof.  
     
     
         35 . The coating according to  claim 18 , wherein said metal object is a metal plate or a metal sheet.