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Anti-tarnish treatment of metal foil

Assignee: Olin Corp
•
Filing: 1989-12-22
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Granted: 1990-08-28
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Expires: 2009-12-22
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Abstract

Abstract A method of imparting tarnish and corrosion resistance to a copper or copper alloy foil, particularly wrought foil having one surface roughened by the application of nodules or dendrites. The foil is treated with an aqueous solution of chromic acid and sulfuric acid. The foil may then be rinsed in a basic solution having a pH greater than 8 and then dried.

Inventors

  • 👤 Lifun Lin
  • 👤 Chung-Yao Chao
  • 👤 Ned W. Polan

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 14:27
CPC Classifications
H; H05; H05K; H05K3/00; H05K3/22; H05K3/28; H05K3/282; C; C23; C23C; C23C22/00; C23C22/05; C23C22/06; C23C22/24; C23C22/82; C23C22/83; C25; C25D; C25D5/00; C25D5/48; C25D5/60; C25D5/605; H05K3/38; H05K3/382; H05K3/385; H05K2201/00; H05K2201/03; H05K2201/0332; H05K2201/0335; H05K2201/0355; H05K2203/00; H05K2203/03; H05K2203/0307; H05K2203/07; H05K2203/0703; H05K2203/0723

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 65 words
A process for imparting tarnish and oxidation resistance to copper and copper alloy foil material, said process comprising: applying a dilute aqueous chromic acid-sulfuric acid solution to said material, said solution having a concentration of chromic acid in the range of about 0.02 g/l to about 5 g/l and a concentration of sulfuric acid in the range of about 0.02 g/l to about 20 g/l.
Claim 2
Dependent Claim 65 words
A process for imparting tarnish and oxidation resistance to copper and copper alloy foil material, said process comprising: applying a dilute aqueous chromic acid-sulfuric acid solution to said material, said solution having a concentration of chromic acid in the range of about 0.02 g/l to about 5 g/l and a concentration of sulfuric acid in the range of about 0.02 g/l to about 20 g/l.
Claim 3
Dependent Claim 14 words
The process of claim 1 further comprising: rinsing said material after applying said solution.
Claim 4
Dependent Claim 14 words
The process of claim 2 further comprising: drying said material after said rinsing step.
Claim 5
Dependent Claim 25 words
The process of claim 2 wherein said rinsing step comprises: applying an aqueous rinse solution have a pH greater than about 8 to said material.
Claim 6
Dependent Claim 42 words
The process of claim 2 wherein said rinsing step comprises: applying an aqueous rinse solution having a pH greater than about 9 to about 11.5 and a temperature in the range of about room temperature to about 100° C. to said material.
Claim 7
Dependent Claim 48 words
The process of claim 5 wherein said rinsing solution contains at least 1 ppm of a material selected from the group consisting of the salts of alkali metals, the salts of alkaline earth metals, the hydroxides of the alkali metals, and the hydroxides of the alkaline earth metals.
Claim 8
Dependent Claim 35 words
The process of claim 5 wherein said rinsing solution contains at least 1 ppm of a material selected from the group consisting of the salts of calcium hydroxide, sodium hydroxide, potassium hydroxide, and ammonium hydroxide.
Claim 9
Dependent Claim 31 words
The process of claim 1 wherein said applying step comprises: immersing said material in said dilute solution for a time i the range of about 1 second to about 120 seconds.
Claim 10
Dependent Claim 50 words
The process of claim 1 wherein said applying step comprises: immersing said material in said dilute solution while said solution is at a temperature in the range of about 20° C. to about 100° C. for a time period in the range of about 1 seconds to about 120 seconds.
Claim 11
Dependent Claim 42 words
The process of claim 1 wherein said applying step comprises: immersing said material in a solution containing from about 0.1 g/l to about 0.3 g/l of said chromic acid and from about 0.02 g/l to about 0.7 g/l of said sulfuric acid.
Claim 12
Dependent Claim 17 words
The process of claim 1 wherein said applying step comprises: spraying said dilute solution onto said material.
Claim 13
Dependent Claim 36 words
The process of claim 1 further comprising: roughening at least one surface of said material prior to said applying step, said roughening step comprising forming a plurality of dendritic particles on said at least one surface.
Claim 14
Dependent Claim 49 words
A treatment for imparting improved tarnish and oxidation resistance to copper and copper alloy material, said treatment comprising a anti-tarnish solution containing from about 0.02 g/l to about 5 g/l of chromic acid, from about 0.02 g/l to about 20 g/l of sulfuric acid and the balance essentially water.
Claim 15
Dependent Claim 49 words
A treatment for imparting improved tarnish and oxidation resistance to copper and copper alloy material, said treatment comprising a anti-tarnish solution containing from about 0.02 g/l to about 5 g/l of chromic acid, from about 0.02 g/l to about 20 g/l of sulfuric acid and the balance essentially water.
Claim 16
Dependent Claim 46 words
The treatment of claim 13 further comprising: said chromic acid concentration in said solution being in the range of about 0.1 g/l to about 0.3 g/l and said sulfuric acid concentration in said solution being in the range of about 0.02 g/l to about 0.7 g/l.
Claim 17
Dependent Claim 33 words
The treatment of claim 13 further comprising: a aqueous caustic rinse solution having a pH greater than about 8, said rinse solution being applied to said material after application of said anti-tarnishing solution.
Claim 18
Dependent Claim 35 words
The treatment of claim 15 wherein said rinse solution has a pH in the range of about 9 to about 11.5 and a temperature in the range of about room temperature to about 100° C.
Claim 19
Dependent Claim 48 words
The process of claim 15 wherein said rinsing solution contains at least 1 ppm of a material selected from the group consisting of the salts of alkali metals, the salts of alkaline earth metals, the hydroxides of the alkali metals, and the hydroxides of the alkaline earth metals.
Claim 20
Dependent Claim 33 words
The treatment of claim 17 wherein said rinse solution contains at least about 1 ppm of a material selected from the group consisting of calcium hydroxide, sodium hydroxide, potassium hydroxide and ammonium hydroxide.
Claim 21
Dependent Claim 83 words
A process for imparting tarnish and oxidation resistance to copper and copper alloy foil material having a plurality of dendritic particles on at least one surface, said process comprising: applying a dilute aqueous chromic acid-sulfuric acid solution to said material having said plurality of dendritic particles, said solution having a concentration of chromic acid in the range of about 0.02 g/l to about 5.0 g/l and a concentration of sulfuric acid in the range of from about 0.02 g/l to about 20 g/l.
Claim 22
Dependent Claim 83 words
A process for imparting tarnish and oxidation resistance to copper and copper alloy foil material having a plurality of dendritic particles on at least one surface, said process comprising: applying a dilute aqueous chromic acid-sulfuric acid solution to said material having said plurality of dendritic particles, said solution having a concentration of chromic acid in the range of about 0.02 g/l to about 5.0 g/l and a concentration of sulfuric acid in the range of from about 0.02 g/l to about 20 g/l.
Claim 23
Dependent Claim 31 words
The process of claim 19 further comprising: applying an aqueous rinse solution having a pH greater than about 8 to said material after said dilute aqueous chromic acid-sulfuric acid solution application.
Claim 24
Dependent Claim 68 words
The process of claim 19 further comprising: rinsing said material in an aqueous rinse solution having a pH in the range of from about 9 to about 11.5 and a temperature in the range of from 20° C. to about 100° C., said solution containing at least about 1 ppm of a material selected from the group consisting of calcium hydroxide, sodium hydroxide, potassium hydroxide, and ammonium hydroxide.
Claim 25
Dependent Claim 75 words
The process of claim 19 wherein said solution applying step comprises: immersing said material in a solution at a temperature in the range of from about 20° C. to about 100° C. for a time period in the range of about 1 seconds to about 120 seconds, said solution containing from about 0.02 g/l to about 5.0 g/l of said chromic acid and from about 0.02 g/l to about 20 g/l of said sulfuric acid.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-08-27 1994-02-26 1994-08-28 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-08-27 1998-02-26 1998-08-28 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-08-27 2002-02-26 2002-08-28 $7700.00 Window Closed / Lapsed

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