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US 3,944,449 AGranted
Method of producing tarnish resistant copper and copper alloys and products thereof
AssigneeOlin Corporation
InventorElmer J. Caule
Life of this patent
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Abstract
The instant invention comprises providing copper or a copper alloy which has on its surface a uniform glassy like and substantially pore free coating of copper phosphate, rinsing the coated material for at least 2 seconds in water at a pH of from 4.9 to 6.3, at a temperature of 90.degree.C to the boiling point and drying.
Claims11
A method of producing a flexible laminate, comprising:
- A. providing a material selected from the group consisting of copper foil and copper sheet,
- B. applying to a surface of said material a phosphoric acid solution of at least 8 percent concentration and containing from 3.5 grams per liter up to the solubility limit of a material selected from the group consisting of sodium dichromate and potassium dichromate and mixtures thereof, for at least 2 seconds, to form a uniform, glassy-like, substantially pore-free coating of copper phosphate from 20 to 1000 Angstroms thick, provided that when the concentration of phosphoric acid is increased, the minimum dichromate concentration is proportionately increased,
- C. rinsing said material for at least two seconds in water at a pH of from about 4.9 to 6.3 and at a temperature from about 90.degree. C up to the boiling point,
- D. drying said material, and
- E. adhesively laminating a plastic film to said surface.
2 more elements
A method of producing a flexible laminate comprising:
- A. providing a material selected from the group consisting
- of copper foil and copper sheet,
- B. oxidizing a surface of said material to form a surface oxide film from 150 to 1000 Angstrom units in thickness,
- C. applying a phosphoric acid solution to said oxide film to form thereon a uniform, glassy-like, substantially porefree coating of copper phosphate,
- D. rinsing said material for at least two seconds in water at a pH of from about 4.9 to 6.3 and at a temperature from about 90.degree. C up to the boiling point,
- E. drying said material, and
- F. adhesively laminating a plastic film to said surface.
4 more elements
Dependencies are inferred from the claim text.