Birchwood Laboratories, Inc.

David J Halverson

William V Block

John T Nguyen

James N Tuttle, Jr

Richard K Williams

John Thanh Ngoc Nguyen

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.

Methods and compositions for coating aluminum substrates

The invention is the chemical composition and method for forming a chemical conversion coating on ferrous metal surfaces and subsequent coloring of said conversion coating through the application of a water-soluble dye. The conversion coating has an ordered crystalline structure composed of ferrous oxalate or other ferrous dicarboxylates. The conversion coating can be colored through the application of a water-soluble reactive dye which bonds with Fe (II) within the ferrous dicarboxylate matrix, bound to the dicarboxylate molecules, thereby becoming water insoluble and permanent. When sealed with an appropriate rust preventive top coat, the result is an attractive and protective finish of minimal thickness which can be applied through simple immersion process techniques. Said finish can serve as a final protective finish on a fabricated ferrous metal article and also affords a degree of lubricity for assembly, break-in purposes, or anti-galling protection and serves as an adhesive base for paint.

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Greenfield, MN, United States of America

David J Halverson