Electrolytic and electroless process for treating metallic surfaces and products formed thereby

Abstract

The disclosure relates to an electroless or electrolytic process for treating metallic surfaces. The process employs a medium comprising at least one oxygen containing water soluble compound (e.g., stannates, molybdates, vanadates and hydrated cerium compounds) having a controlled and predetermined concentration, temperature and pH wherein the metallic surface is at least partially corroded or solubilized.

1 . A method for treating a substrate having an electrically conductive surface comprising: 
 contacting at least a portion of the surface with a medium comprising at least one oxygen containing water soluble and having a basic pH and wherein said medium is substantially free of chromates,    drying the substrate,    rinsing the substrate, and;    again drying the substrate.    
     
     
         2 . An aqueous medium for use in increasing the electrical resistance of a conductive surface comprising a combination comprising water, at least one member selected from the group of water soluble stannates, molybdates, vanadates and hydrated cerium compounds, wherein the medium has a basic pH and is substantially free of chromates.  
     
     
         3 . The medium of  claim 2  wherein said medium further comprises colloidal silica.  
     
     
         4 . The method of  claim 1  wherein the surface comprises at least one member selected from the group consisting of copper, nickel, tin, iron, zinc, aluminum, magnesium, stainless steel and steel and alloys thereof.  
     
     
         5 . The method of  claim 1  wherein said drying is conducted at a temperature of at least about 120 C.  
     
     
         6 . The method of  claim 1  further comprising applying at least one coating upon the last dried surface.  
     
     
         7 . The method of  claim 1  further comprising applying an adherent composition comprising at least one member chosen from the group of latex, silanes, epoxies, silicone, amines, alkyds, urethanes and acrylics.  
     
     
         8 . The method of  claim 1  wherein said medium comprises the medium of  claim 2 .  
     
     
         9 . The method of  claim 1  wherein said medium comprises the medium of  claim 3 .  
     
     
         10 . The medium of  claim 2  wherein said water soluble compounds comprise at least one member selected from the group consisting of sodium stannate hydrate, sodium molybdate hydrate, ammonium metavanadate and cerium nitrate hydrate.  
     
     
         11 . The method of  claim 1  wherein the pH is sufficient to at least partially dissolve the surface.