Rinsing coated metallic surfaces
AssigneeAmchem Products, Inc.
InventorsWilbur S. Hall, Lester Steinbrecher
Life of this patent
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Abstract
A metallic surface is coated with a polymeric resinous coating by immersing the surface in an acidic aqueous coating composition comprising polymeric resinous coating-forming material and an oxidizing agent. The corrosion resistance and/or the surface appearance of the resinous coating is modified by rinsing the coating with an aqueous rinse solution containing hexavalent chromium or an aqueous rinse solution containing hexavalent chromium and reduced forms of chromium.
Claims46
A method for modifying the properties of a polymeric resinous-coated metallic surface comprising:
- forming a polymeric resinous coating on a metallic surface by treating the surface with an acidic aqueous coating composition comprising a polymeric resinous coating-forming material and an oxidizing agent and thereafter treating the polymeric resinous coating with an aqueous rinse solution containing hexavalent chromium in an amount at least sufficient to improve the corrosion resistant properties of said coating.
A method for coating a metallic surface comprising:
- immersing the surface in an aqueous composition comprising, in coating-forming amounts, hydrogen ion, fluoride ion, an oxidizing agent selected from the class consisting of hydrogen peroxide and dichromate, and particles of resin dispersed in the composition;
- withdrawing the resinous-coated surface from the composition;
- and treating said resinous coated surface with an aqueous rinse solution comprising hexavalent chromium in an amount at least sufficient to improve the corrosion resistant properties of said coating.
A process for applying a coating to a metallic surface comprising:
- a. immersing a metallic surface in an aqueous acidic organic coating composition comprising, in coating-forming proportions, water, hydrogen ion, an oxidizing agent which contains oxygen, and an organic coating material selected from the group consisting of water-soluble, water-dispersible and water-emulsifiable film-forming polymeric resinous materials;
- b. depositing said resinous material on said surface to form thereon a resinous coating while said surface is immersed in said composition;
- c. maintaining said surface in said composition and depositing thereon additional resinous material to thereby produce a resinous coating, the thickness of of which increases during at least a portion of the time said surface is immersed in said composition;
- and
- d. withdrawing the resinous-coated surface from said composition after the desired amount of resinous coating has been deposited on said surface;
- wherein said composition will produce said coating on said metallic surface in the absence of any electrical charge on said metallic surface other than that imparted thereto by said composition;
- and wherein said composition is sufficiently acidic to effect an increase in the amount of resinous coating deposited within at least about 10 minutes from the time said metallic surface is immersed in said composition;
- and wherein said resinous coating is initially adherent and resists being removed from said surface when it is rinsed after it is withdrawn from said composition;
- and
- e. thereafter treating the resinous coated surface with an aqueous rinse solution containing chromium in an amount at least sufficient to improve the corrosion resistant properties of said coating.
An improvement in the process of coating metallic articles by acidic deposition which comprises:
- contacting an unbaked or uncured acidic deposited coating of a synthetic film-forming resin on a metallic article with a solution comprising a material selected from the group consisting of chromium trioxide, and water or acid soluble chromates and dichromates, wherein said material is present in said solution in an amount at least sufficient to improve the corrosion resistant properties of said coating.
An improvement in the process of coating metallic articles by acidic deposition which comprises:
- contacting an unbaked or uncured acidic deposited coating of a synthetic film-forming resin on a metallic article with a solution comprising a material selected from the group consisting of chromium trioxide, and water or acid soluble chromates and dichromates;
- and baking said article for a time sufficient to cure the coating thereon;
- wherein said material is present in said solution in an amount at least sufficient to improve the corrosion resistant properties of said coating.
Dependencies are inferred from the claim text.