Claims
- 1. A method of producing a colored anodized aluminum strip which comprises drawing aluminum in strip form successively through an anodizing stage and an electrolytic coloring stage comprising in the anodizing stage moving the strip successively past one or more anodes immersed in a sulphuric acid anodizing electrolyte and past one or more cathodes and passing direct current between said cathodes and said anodes through the strip so as to render the strip initially cathodic and subsequently anodic to develop an anodic oxide film on the surface thereof, the thus anodized strip being then passed through, in said electrolytic coloring stage, an acidic electrolyte containing a material selected from a salt of at least one of copper, tin, cobalt, nickel, chromium, iron, silver or lead, or a manganate, tellurite or selenite, and passing alternating current between at least one electrode immersed in said acidic electrolyte and said anodized strip, the circuit for said alternating current being completed through an electrode immersed in the electrolyte of the direct current anodizing stage.
- 2. A method according to claim 1 in which a direct current component is superimposed on the alternating current in the electrolytic coloring stage.
- 3. A method according to claim 2 in which an alternating current source is connected between an anode of the anodizing stage and the electrode in the electrolytic coloring stage whereby a direct current component is superimposed on the alternating current in the electrolytic coloring stage.
- 4. A method of producing a colored anodized aluminum strip which comprises drawing aluminum in strip form successively through an anodizing electrolyte and an acidic coloring electrolyte containing a material selected from a salt of at least one of copper, tin, cobalt, nickel, chromium, iron, silver or lead or a manganate, tellurite or selenite, passing direct current between said strip and at least one cathode immersed in said anodizing electrolyte, direct current being introduced into said strip through an electrical contact at a location where said strip is substantially unanodized and passing alternating current between the anodized strip and at least one electrode immersed in the coloring electrolyte, the circuit for the alternating current being completed by contact with a substantially unanodized area of the surface of the aluminum strip to generate an asymmetric current wave form; the unanodized strip, before entry into the anodization stage, being in contact with a contact roll connected to the positive terminal of said direct current supply and an alternating current source being connected between said contact roll and the electrode in the coloring electrolyte; diode branches in parallel being included in the connection between the contact roll and the coloring electrolyte electrode, the diodes in said branches being conductive in opposite directions, the voltage drops across said diode branches when conductive being unequal whereby to generate an asymmetrical alternating current.
- 5. A method of producing a colored anodized aluminum strip which comprises drawing aluminum in strip form through an anodizing stage, contacting the strip with a sulphuric acid electrolyte in said anodizing stage, said strip being drawn successively past at least one anode electrode and at least one cathode electrode, a D.C. power source being established between said anode electrode and said cathode electrode whereby said strip in rendered initially cathodic and subsequently anodic during its passage through said anodizing stage, advancing the thus anodized strip to and through an electrolytic coloring stage, contacting said strip with an acidic electrolyte containing a material selected from a salt of at least one of copper, tin, cobalt, nickel, chromium, iron, silver or lead or a manganate, tellurite or selenite and establishing an A.C. power source between said anode electrode in said anodizing stage and a counterelectrode in contact with the electrolyte in the electrocoloring stage thereby to establish alternating current with a superimposed D.C. current component flowing between said anodized strip and said counterelectrode in the electrocoloring stage.
- 6. A method according to claim 5 in which said strip successively passes a first anode and a second anode longitudinally spaced from said first anode in the anodizing stage, said anodes being connected in parallel to said A.C. power source, further including establishing a higher resistance path between said A.C. power source and said second anode than the path between said A.C. power source and said first anode.
- 7. A method of producing a colored anodized aluminum strip which comprises drawing aluminum in strip form successively through an anodizing electrolyte and an acidic coloring electrolyte containing a material selected from a salt of at least one of copper, tin, cobalt, nickel, chromium, iron, silver or lead or a manganate, tellurite or selenite, passing direct current between said strip and at least one cathode immersed in said anodizing electrolyte, direct current being introduced into said strip through an electrical contact at a location where said strip is substantially unanodized and passing alternating current between the anodized strip and at least one electrode immersed in the coloring electrolyte, the circuit for the alternating current being completed by contact with a substantially unanodized area of the surface of the aluminum strip to generate an asymmetric current wave form; the alternating-current-passing step comprising passing alternating current through the strip between at least one electrode immersed in the coloring electrolyte and out of contact with said strip and at least one electrode immersed in the anodizing electrolyte and facing a substantially unanodized area of said strip.
- 8. A process for electrolytically treating aluminum or its alloy in the form of a strip, wire or foil material in a continuous manner which comprises continuously passing the material through an anodic oxidation treatment cell and an electrolytic coloring cell to carry out electrolysis in said cells to anodize and color the material in a continuous manner, characterized in that just prior to the anodizing stage, a circuit is formed by commonly connecting to the aluminum material a power source for anodizing and a power source for electrolytically coloring, said power source for anodizing being further connected to the anodizing cell and said power source for electrolytically coloring being further connected to the electrolytic coloring cell; said power source for anodizing being DC and the power source for electrolytically coloring being AC, or the power source for both of them being a single AC-superimposed direct current, whereby a current having an alternating wave form rich in positive component is supplied to the electrode of the electrolytic coloring cell.
- 9. The process according to claim 8 wherein the electrolytic coloring is carried out in a solution containing a tin salt.
- 10. The process according to claim 8 wherein the electrolytic coloring is effected in a solution containing a tin salt and at least one member selected from the group consisting of nickel salts, cobalt salts, iron salts, and magnesium salts.
- 11. The process according to claim 8 wherein the electrolytic coloring is carried out in a solution containing at least one member selected from the group consisting of copper salts, selenium salts, and manganese salts.
- 12. The process according to claim 8 wherein a direct current voltage is applied between an electric power supply element outside the anodic oxidation treatment cell and an electrode plate within said cell and an alternating current voltage is applied between said element and an electrode plate within the electrolytic coloring cell.
- 13. A process according to claim 8, wherein the aluminum material is charged with a current having an alternating wave form rich in cathodic component in the electrolytic coloring cell.
- 14. A process for electrolytically treating aluminum or its alloy in the form of a continuous elongated material in a continuous manner which comprises continuously passing the material through an anodic oxidation treatment cell and an electrolytic coloring cell to carry out electrolysis in said cells to anodize and color the material in a continuous manner, characterized in that just prior to the anodizing stage, a circuit is formed by commonly connecting to the aluminum material a power source for anodizing and a power source for electrolytically coloring, said power source for anodizing being further connected to the anodizing cell and said power source for electrolytically coloring being further connected to the electrolytic coloring cell; said power source for anodizing being a current to anodize the aluminum material in the anodizing cell and said power source for electrolytically coloring being a current having an alternating wave form to color the aluminum material in the coloring cell.
- 15. The process according to claim 14 wherein the electrolytic coloring is carried out in a solution containing a tin salt.
- 16. The process according to claim 14 wherein the electrolytic coloring is effected in a solution containing a tin salt and at least one member selected from the group consisting of nickel salts, cobalt salts, iron salts, magnesium salts, copper salts, chromium salts, silver salts, lead salts, manganites, tellurites, and selenites.
- 17. The process according to claim 14 wherein the electrolytic coloring is carried out in a solution containing at least one member selected from the group consisting of copper salts, selenium salts, manganese salts, tin salts, cobalt salts, nickel salts, chromium salts, iron salts, silver salts, lead salts, and tellurites.
- 18. The process according to claim 14 wherein a direct current voltage is applied between an electric power supply element outside the anodic oxidation treatment cell and an electrode plate within said cell and an alternating current voltage is applied between said element and an electrode plate within the electrolytic coloring cell.
- 19. A process according to claim 14 wherein the aluminum material is charged with a current having an alternating wave form rich in cathodic component in the electrolytic coloring cell.
- 20. A process for electrolytically treating aluminum or its alloy in the form of a strip material in a continuous manner which comprises continuously passing the material through an anodic oxidation treatment cell and an electrolytic coloring cell to carry out electrolysis in said cells to anodize and color the material in a continuous manner, characterized in that just prior to the anodizing stage, a circuit is formed by commonly connecting to the aluminum material a power source for anodizing and a power source for electrolytically coloring, said power source for anodizing being further connected to the anodizing cell and said power source for electrolytically coloring being further connected to the electrolytic coloring cell; said power source for anodizing being DC and the power source for electrolytically coloring being AC, whereby a current having an alternating wave form rich in positive component is supplied to the electrode of the electrolytic coloring cell.
- 21. The process according to claim 20 wherein the electrolytic coloring is carried out in a solution containing a tin salt.
- 22. The process according to claim 20 wherein the electrolytic coloring is effected in a solution containing a tin salt and at least one member selected from the group consisting of nickel salts, cobalt salts, and iron salts.
- 23. The process according to claim 20 wherein the electrolytic coloring is carried out in a solution containing at least one member selected from the group consisting of copper salts, selenium salts, and manganese salts.
- 24. The process according to claim 20 wherein a direct current voltage is applied between an electric power supply element outside the anodic oxidation treatment cell and an electrode plate within said cell and an alternating current voltage is applied between said element and an electrode plate within the electrolytic coloring cell.
- 25. A process according to claim 20 wherein the aluminum material is charged with a current having an alternating wave form rich in cathodic component in the electrolytic coloring cell.
Parent Case Info
This is a continuation of applicaton Ser. No. 550,741, filed Feb. 18, 1975, now abandoned.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
4014758 |
Kawai et al. |
Mar 1977 |
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Continuations (1)
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Number |
Date |
Country |
Parent |
550741 |
Feb 1975 |
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