James R Tuttle

US Patent:

57231834, Mar 3, 1998

Filed:

Sep 16, 1996

Appl. No.:

8/714550

Inventors:

Richard K. Williams - Minnetonka MN
David J. Halverson - Long Lake MN
James N. Tuttle - Harwich Port MA

Assignee:

Birchwood Laboratories, Inc. - Eden Prairie MN

International Classification:

B05D 138
B05D 300
C23C 2284

US Classification:

427409

Abstract:

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.