Secondary protective treatments for metal surfaces
AssigneeHenkel Corporation
InventorsLawrence R. Carlson, Philip M. Johnson, John R. Pierce
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Abstract
Seal coating compositions and methods of applying them to metallic surfaces, particularly aluminum or alloys thereof, beating a previously formed protective coating, particularly a conversion coating, such as a chromate or phosphate coating or a chrome-free metal oxide conversion coating, or a coating formed by anodization, provide improved corrosion resistance beyond that provided by the previously formed protective coating. The seal coating compositions preferably contain at least one of benzotriazole, nickel and/or cobalt cations and borates, or aminated polymers of vinyl styrene.
Claims10
A process for increasing the corrosion resistance of a metal object bearing a pre-existing protective coating, said process comprising steps of:
- (I) contacting the pre-existing coating with a sealing composition consisting essentially of water and;
- (A) benzotriazole and, optionally, one or more of the following;
- (B) other water soluble corrosion inhibitors for aluminum;
- (C) water soluble poly{oxyalkylenes};
- and
- (D) surfactants;
- and
- (II) drying the metal object after completion of step (A).
Dependencies are inferred from the claim text.