Process for producing an ornamental rust finish on a ferrous metal surface

• US 5,728,236 A
• Filed: 10/24/1995
• Issued: 03/17/1998
• Est. Priority Date: 10/24/1995
• Status: Expired due to Fees

• Current Assignee: ChemPro, Inc. (CR Brands Incorporated)
• Original Assignee: Chem-Pro
• Inventors: Rundhaug, Patrick A.
• Primary Examiner(s): Silverberg, Sam
• Application Number:
  US08/547,227
• Time in Patent Office: 875 Days
• Field of Search: 148/269, 148/270, 148/273, 148/271
• US Class Current: 148/270
• CPC Class Codes: B44C 1/005 by altering locally the surface material surface treatment to obtain special artistic surface effects or finishes B44D5/00
• CPC Class Codes: C23C 22/46 containing oxalates
• CPC Class Codes: C23C 22/50 Treatment of iron or alloys based thereon

Abstract

A chemically derived product that rusts metal instantly upon contacting the surface of a metal and which can be easily and safely used by ornamental metal craftpersons. The chemically derived product is a liquid compound that contains the following constituents: (a) 93.0% by weight of water; (b) up to 5.0% by weight of a copper salt, the copper salt being selected from a copper salt group consisting of copper sulfate, copper nitrate, and copper chloride; and (c) a remaining amount consisting of an acid compound selected from an acid compound group consisting of sulfamic acid, oxalic acid, hydrochloric acid and nitric acid. The liquid compound can be particularly formulated for oxidizing steel or copper and may be produced having a predetermined coloring dye constituent selected from a color dye group consisting of copper, auburn, or gold, if oxidizing steel, or a color dye selected from a color dye group consisting of patina, aqua blue, or green, if oxidizing copper.

Claims

1. A process for producing an ornamental rust finish on a ferrous metal surface, comprising the steps of:

(a) applying to said ferrous metal surface an aqueous solution having ferric oxide-forming oxidizing reactivity with said ferrous metal surface, said aqueous solution comprising a copper salt and an acid in relative concentrations effective for imparting said oxidizing reactivity to said aqueous solution, said copper salt being selected from the group consisting of copper sulfate, copper nitrate and copper chloride said acid being selected from the group consisting of sulfamic acid and oxalic acid; and

(b) oxidizing said ferrous metal surface with said aqueous solution so as to form said rust finish as an oxidation reaction product composed primarily of ferric oxide.

2. The process of claim 1, wherein said aqueous solution comprises up to 5.0% by weight of said copper salt and at least 1.0% by weight of said acid.

3. The process of claim 2, wherein said copper salt is cooper sulfate and said acid is sulfamic acid.

4. The process of claim 1, wherein said aqueous solution further comprises a coloring dye selected from a color dye group consisting of copper, auburn and gold.

5. The process of claim 1, whereto said aqueous solution is applied to said ferrous metal surface by spraying a mist of said aqueous solution onto said ferrous metal surface.