Methods and compositions for coating aluminum substrates

摘要

The present invention relates to methods and compositions for coating aluminum substrates. In an embodiment, the invention includes a method of applying a coating on an aluminum substrate including contacting the aluminum substrate with a first solution. The first solution can include a zinc metal salt, a sugar acid or alkali metal salt thereof, and an alkali metal hydroxide. The method can also include contacting the aluminum substrate with a second solution. The second solution can include a molybdate salt, an alkanolamine, and a fluorine acid. Other embodiments are also included herein.

主权项

1. A kit for applying a coating exhibiting black color stability for a period of 60 days to an aluminum substrate, the kit comprising:
a first solution comprising
at least about 2 grams per liter of a zinc metal salt;at least about 2 grams per liter of a sugar acid selected from the group consisting of gluconic acid, glucoheptonic acid, and alkali metal salts thereof;at least about 20 grams per liter of an alkali metal hydroxide; and a second solution comprising
at least about 20 grams per liter of a molybdate salt;at least about 10 grams per liter of an alkanolamine; andat least about 2 grams per liter of a fluorine acid.