Colorless sealing layers for anodized aluminum surfaces
AssigneeHenkel Kommanditgesellschaft auf Aktien
InventorsDieter Brodalla, Winfried Kirchhoff, Hans J. Goehausen
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Abstract
A process and composition for producing colorless, cold-sealed, anodized aluminum or aluminum alloy surfaces. The composition comprises an aqueous solution containing nickel ions and a solution of at least one azo or azo metal dye, the colors imparted by the nickel ions and dye offsetting each other.
Claims35
A process for producing colorless, cold-sealed, anodized aluminum or aluminum alloy surfaces comprising the treatment of said surfaces at a temperature of about 15.degree.-70.degree. C. with
- (A) an aqueous solution consisting essentially of nickel ions, present in a sealingly effective amount and
- (B) an aqueous solution consisting essentially of at least one organic dye present in an amount effective to offset any color imparted to said surface by said nickel ions which
- (a) has an absorption maximum of about from 450 to 600 nm;
- (b) has an extinction coefficient of at least 10.sup.3 liter/mol cm;
- (c) is capable of being dissolved to form a molecular dispersion;
- and
- (d) does not undergo a precipitation reaction with nickel ions or the other components of the solution at the treatment solution concentrations wherein said solutions are used simultaneously or in any sequence.
A composition for producing colorless, cold-sealed, anodized aluminum or aluminum alloy surfaces consisting essentially of the mixture:
- (A) an aqueous solution containing nickel ions present in a sealingly effective amount;
- and
- (B) an aqueous solution containing at least one organic dye present in an amount effective to offset any color imparted to said aluminum or aluminum alloy surface by said nickel ions, wherein said at least one organic dye
- (a) has an absorption maximum of from 450 to 600 nm;
- (b) has an extinction coefficient of at least 10.sup.3 liter/mol cm;
- (c) is capable of being dissolved to form a molecular dispersion;
- and
- (d) does not undergo a precipitation reaction with nickel ions or the other components of said solution at the treatment solution concentration.
Dependencies are inferred from the claim text.