Energy enhanced process for treating a conductive surface and products formed thereby
View Patent ↗The disclosure relates to a process for forming a deposit on the surface of a metallic or conductive surface. The process employs an energy enhanced process to deposit a silicate containing coating or film upon a metallic or conductive surface.
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 water and at least one silicate,
introducing a current to said medium wherein said surface is employed as a cathode under conditions and form a time sufficient to form a film comprising silica upon the surface; and
recovering the substrate.
2. The method of claim 1 wherein the silicate containing medium comprises sodium silicate.
3. 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.
4. The method of claim 1 wherein further comprising a post-treatment comprising contacting the surface with a second medium comprising a combination comprising water and at least one water soluble compound selected from the group consisting of chlorides, fluorides, nitrates, zirconates, titanates, sulphates and water soluble lithium compounds.
5. The method of claim 1 further comprising a post-treatment comprising contacting with a medium comprising at least one of silanes and silica.
6. The method of claim 4 wherein said water soluble compound comprises at least one member selected from the group consisting of from the group of titanium chloride, tin chloride, zirconium acetate, zirconium oxychloride, calcium fluoride, tin fluoride, titanium fluoride, zirconium fluoride; ammonium fluorosilicate, aluminum nitrate; magnesium sulphate, sodium sulphate, zinc sulphate, copper sulphate; lithium acetate, lithium bicarbonate, lithium citrate, lithium metaborate, lithium vanadate and lithium tungstate.
7. The method of claim 1 further comprising a post-treatment comprising contacting with at least one member selected from the group consisting of nitric acid, citric acid, and ammonium dibasic group.
8. A method for treating a metallic or an electrically conductive surface comprising:
exposing at least a portion of the surface to a medium comprising at least one polar carrier and at least one silicate that is soluble within said carrier wherein said medium has a basic pH and is substantially free of chromates,
introducing an energy source into said medium, wherein the surface is employed as a cathode;
recovering the surface from the medium wherein the treated surface comprises a first film comprising at least one silicate and a second film upon the first film comprising silica.
9. The method of claim 8 wherein the medium comprises greater than 3 wt. % of at least one silicate.
10. The method of claim 8 wherein said medium comprises an anode that comprises platinum or nickel.
11. The method of claim wherein the silicate containing medium further comprises at least on dopant.
12. The method of claim 11 wherein the dopant comprises at least one member selected from the group consisting of molybdenum, chromium, titanium, zirconium, vanadium, phosphorus, aluminum, iron, boron, bismuth, gallium, tellurium, germanium, antimony, niobium, magnesium, manganese, and their oxides and salts.
13. The method of claim 11 wherein the dopant is provided by the anode of the electrolytic environment.
14. The method of claim 8 further comprising contacting said surface with at least one member selected from the group consisting of nitric acid, citric acid and ammonium dibasic citrate subsequent to said recovering.
15. The method of claim 8 further comprising applying a coating composition comprising at least one member chosen from the group of latex, silanes, epoxies, silicone, amines, alkyds, urethanes and acrylics.
16. A method for treating a substrate having an electrically conductive surface comprising:
establishing an electrolytic environment within a medium comprising water and at least one silicate wherein said medium is substantially free of chromates,
contacting at least a portion of the surface with the medium, wherein said surface is employed as a cathode, under conditions and form a time sufficient to form a film comprising silica upon the surface; and recovering the substrate.
17. The method of claim 16 wherein the medium has a basic pH and comprises water, sodium silicate and silica.
18. The method of claim 16 further comprising anodically cleaning the surface prior to said contacting.
19. The method of claim 16 wherein the medium is substantially free of heavy metals.
20. The method of claim 16 further comprising applying at least one coating upon the recovered substrate.
21. The method of claim 20 wherein the coating comprises at least one member selected from the group consisting of silanes, epoxies, latexes, acrylics, titanates and zirconates.
22. The method of claim 16 further comprising rinsing the recovered substrate.