Low temperature sealing of anodized aluminum
AssigneeAluminum Company of America
InventorsEdward G. Remaley, Robert W. Baker, Raymond J. Meyer
Life of this patent
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Abstract
A method of forming a low temperature seal on anodized aluminum and removing sealing smudge therefrom comprises treating anodized aluminum with an aqueous sealing solution at a temperature of at least 140.degree. F. and containing 2 to 6 g/l of hydrolyzable metallic salt, 5 to 20 ml/l of an ethanolamine and 50 to 2000 mg/l soluble sulfate (SO.sub.4 .sup.=), and thereafter removing sealing smudge formed by this treatment with mineral acid.
Claims8
A method for forming a low temperature seal on anodized aluminum and removing sealing smudge therefrom comprising:
- a. contacting said anodized aluminum with an aqueous sealing solution containing 2 to 6 g/l of hydrolyzable metallic salt, 5 to 20 ml/l of an ethanolamine, and 50 to 2000 mg/l soluble sulfate (SO.sub.4 .sup.=), for a period of time sufficient to provide said seal, said solution being capable of providing a seal at a temperature of at least 140.degree. F;
- and
- b. removing sealing smudge formed in said prior step with mineral acid.
A method of forming a low temperature seal on anodized aluminum and removing sealing smudge therefrom comprising:
- a. providing a sealing solution consisting essentially of water, 2 to 6 g/l hydrolyzable metallic salt selected from the group consisting of nickel acetate and nickel sulfate, 5 to 20 ml/l of triethanolamine, and 50 to 2000 mg/l soluble sulfate (SO.sub.4 .sup.=), wherein said soluble sulfate (SO.sub.4 .sup.=) is added to said water before said salt or said triethanolamine,
- b. treating said anodized aluminum in said sealing solution at a temperature in the range of 150.degree. to 170.degree. F for a time period not greater than 45 minutes to provide said seal, and
- c. removing sealing smudge formed in said treating step with mineral acid to provide smudge-free, anodized aluminum.
Dependencies are inferred from the claim text.