Back to results
US 3,945,895 AGranted
Method of producing colored anodic coating on aluminum and its alloys
AssigneeFujisash Industries, Ltd.
InventorsMasanori Osuga, Hayao Adachi
Life of this patent
Estimating the term…
Abstract
Colored anodic coating of aluminum and its alloys can be obtained by immersing the aluminum or its alloys as an anode in an aqueous electrolyte solution containing aromatic sulfonic acid and at least one of formic acid and formate salts, which solution preferably contains at least one of sulfuric acid and water soluble sulfate or bisulfate salts and by passing electric current through the electrolyte solution for a predetermined time.
Claims13
A method of producing colored anodic coating on aluminum and its alloys comprising:
- providing at least one cathode;
- immersing the aluminum or its alloys as an anode into an aqueous electrolyte comprising an aromatic sulfonic acid;
- passing a direct current through the electrolyte solution between the anode and cathode to obtain a colored anodic coating on the aluminum;
- wherein, an improvement comprises employing, as said aqueous electrolyte, an aqueous electrolyte solution containing (a) aromatic sulfonic acid in an amount of 10 to 500 g/liter and (b) at least one member selected from the group consisting of formic acid and formate salts in an amount of 5 to 200 g, in terms of the weight of formic acid, per liter of the electrolyte.
1 more element
A method of producing colored anodic coating on aluminum and its alloys comprising:
- providing at least one cathode;
- immersing the aluminum or its alloys as an anode into an aqueous electrolyte comprising aromatic sulfonic acid;
- passing a direct current through the electrolyte solution between the anode and cathode to obtain a colored anodic coating on the aluminum anode;
- wherein an improvement comprises employing, as said aqueous electrolyte, an aqueous electrolyte solution containing (a) aromatic sulfonic acid in an amount of from 10 to 500 g/liter (b) at least one first member selected from the group consisting of formic acid and formate salts in an amount of from 5 to 200 g, in terms of the weight of formic acid, per liter of the electrolyte and (c) at least one second member selected from the group consisting of sulfuric acid and water soluble sulfate or bisulfate salts in an amount not higher than 5g, in terms of the weight of sulfuric acid, per litre of the electrolyte.
1 more element
Dependencies are inferred from the claim text.