US4452643A
Expired / Lapsed
US
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Method of removing copper and copper oxide from a ferrous metal surface
Assignee: Halliburton Co
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Filing: 1983-01-12
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Granted: 1984-06-05
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Expires: 2003-01-12
Abstract
Abstract A method of removing copper and copper oxide from a ferrous metal surface comprising contacting said metal and said copper oxide with an aqueous composition having a pH from about 3.0 to about 6.0 and comprising an oxidizing agent, a compound selected from the group consisting of oxalic acid, the alkali metal, and ammonium salts of oxalic acid and mixtures thereof, and an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids and mixtures thereof.
Inventors
- 👤 Larry D. Martin
- 👤 Gary W. Bradley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 19:43
CPC Classifications
C; C23; C23G; C23G1/00; C23G1/02; C23G1/08; C23G1/088; C23G1/24
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
107 words
A method of removing copper and copper oxide from a ferrous metal surface comprising: contacting said copper and copper oxide with an aqueous composition having a pH of from about 3.0 to about 6.0 said composition consisting essentially of: (a) an oxidizing agent which is stable at a pH of about 3.0 to about 6.0; (b) a compound selected from the group consisting of oxalic acid, the alkali metal and ammonium salts of oxalic acid and mixtures thereof; and, (c) an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids, and mixtures thereof.
Claim 2
Independent Claim
107 words
A method of removing copper and copper oxide from a ferrous metal surface comprising: contacting said copper and copper oxide with an aqueous composition having a pH of from about 3.0 to about 6.0 said composition consisting essentially of: (a) an oxidizing agent which is stable at a pH of about 3.0 to about 6.0; (b) a compound selected from the group consisting of oxalic acid, the alkali metal and ammonium salts of oxalic acid and mixtures thereof; and, (c) an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids, and mixtures thereof.
Claim 3
Dependent Claim
13 words
The method recited in claim 1 wherein said oxidizing agent is hydrogen peroxide.
Claim 4
Dependent Claim
16 words
The method recited in claim 1 wherein said compound is the ammonium salt of oxalic acid.
Claim 5
Dependent Claim
47 words
The method recited in claim 1 wherein said ingredient is selected from the group consisting of ethylenediamine tetraacetic acid, diethylenetriamine pentaaceticacid, N-2-hydroxyethylethylene diamine triacetic acid, propylene-1,2-diamine tetraacetic acid, propylene-1,3 diamine tetraacetic acid, nitrilo triacetic acid, the ammonium and alkali metal salts of said acids, and mixtures thereof.
Claim 6
Dependent Claim
12 words
The method recited in claim 1 wherein said ingredient is citric acid.
Claim 7
Dependent Claim
13 words
The method recited in claim 2 wherein said ingredient is nitrilo triacetic acid.
Claim 8
Dependent Claim
22 words
The method recited in claim 1 wherein said composition is contacted with the metal surface at a temperature of about 100° F.
Claim 9
Dependent Claim
24 words
The method recited in claim 2 wherein said hydrogen peroxide is present in the range of about 2 percent by weight of the composition.
Claim 10
Dependent Claim
12 words
The method recited in claim 1 wherein said pH is about 4.5.
Claim 11
Independent Claim
132 words
A method of cleaning a ferrous metal surface whereby copper and copper oxide is removed from said surface without replating of said copper and said copper oxide on said metal surface comprising: contacting the surface for a sufficient time to remove the copper and copper oxide with an aqueous composition having a pH of about 3.0 to about 6.0 said composition consisting essentially of: (a) an oxidizing agent which is stable at a pH of about 3.0 to about 6.0; (b) a compound selected from the group consisting of oxalic acid, the alkali metal and ammonium salts of oxalic acid and mixtures thereof; and, (c) an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids, and mixtures thereof.
Claim 12
Independent Claim
132 words
A method of cleaning a ferrous metal surface whereby copper and copper oxide is removed from said surface without replating of said copper and said copper oxide on said metal surface comprising: contacting the surface for a sufficient time to remove the copper and copper oxide with an aqueous composition having a pH of about 3.0 to about 6.0 said composition consisting essentially of: (a) an oxidizing agent which is stable at a pH of about 3.0 to about 6.0; (b) a compound selected from the group consisting of oxalic acid, the alkali metal and ammonium salts of oxalic acid and mixtures thereof; and, (c) an ingredient selected from the group consisting of citric acid, polyaminocarboxylic acids, the ammonium and alkali metal salts of citric acid and polyaminocarboxylic acids, and mixtures thereof.
Claim 13
Dependent Claim
13 words
The method recited in claim 10 wherein said oxidizing agent is hydrogen peroxide.
Claim 14
Dependent Claim
16 words
The method recited in claim 10 wherein said compound is the ammonium salt of oxalic acid.
Claim 15
Dependent Claim
47 words
The method recited in claim 10 wherein said ingredient is selected from the group consisting of ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid, N-2-hydroxyethylethylene diamine triacetic acid, propylene-1,2-diamine tetraacetic acid, propylene-1,3 diamine tetraacetic acid, nitrilotriacetic acid, the ammonium and, alkali metal salts of said acids, and mixtures thereof.
Claim 16
Dependent Claim
12 words
The method recited in claim 10 wherein said ingredient is citric acid.
Claim 17
Dependent Claim
13 words
The method recited in claim 10 wherein said ingredient is nitrilo triacetic acid.
Claim 18
Dependent Claim
22 words
The method recited in claim 10 wherein said composition is contacted with the metal surface at a temperature of about 100° F.
Claim 19
Dependent Claim
24 words
The method recited in claim 11 wherein said hydrogen peroxide is present in the range of about 2 percent by weight of the composition.
Claim 20
Dependent Claim
12 words
The method recited in claim 10 wherein said pH is about 4.5.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-06-05 | 1987-12-05 | 1988-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-05 | 1991-12-05 | 1992-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-05 | 1995-12-05 | 1996-06-05 | $7700.00 | Window Closed / Lapsed |