US4439491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Oxidation retardant for graphite
Assignee: GREAT LAKES CARBON Corp
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Filing: 1982-11-18
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Granted: 1984-03-27
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Expires: 2002-11-18
Abstract
Abstract Carbon or graphite is protected against oxidation by application of a solution comprising monoammonium phosphate, zinc orthophosphate, phosphoric acid, boric acid, cupric oxide, wetting agent in water.
Inventors
- 👤 William F. Wilson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:37
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5076; C04B41/5092; C04B41/80; C04B41/81; C04B41/85; H; H05; H05B; H05B7/00; H05B7/02; H05B7/12; Y; Y10; Y10T; Y10T428/00; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/30
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
24 words
An oxidation retardant solution for carbon and graphite comprising a solution of monobasic ammonium phosphate, zinc orthophosphate, phosphoric acid, boric acid and cupric oxide.
Claim 2
Dependent Claim
24 words
An oxidation retardant solution for carbon and graphite comprising a solution of monobasic ammonium phosphate, zinc orthophosphate, phosphoric acid, boric acid and cupric oxide.
Claim 3
Dependent Claim
39 words
The solution of claim 1 containing approximately 10 to 30% of monobasic ammonium phosphate, 2 to 6% of zinc orthophosphate, 8 to 25% of phosphoric acid, 0.1 to 1% of cupric oxide, and 0.1 to 1% of wetting agent.
Claim 4
Dependent Claim
10 words
A graphite electrode treated with the solution of claim 1.
Claim 5
Dependent Claim
31 words
An oxidation retardant solution for elemental carbon comprising by weight, monoammonium phosphate, 19.8%; zinc orthophosphate, 3.5%; phosphoric acid, 15.3%; boric acid, 0.9%; cupric oxide 0.3%; wetting agent 1%; and water 59.2%.
Claim 6
Dependent Claim
31 words
An oxidation retardant solution for elemental carbon comprising by weight, monoammonium phosphate, 19.8%; zinc orthophosphate, 3.5%; phosphoric acid, 15.3%; boric acid, 0.9%; cupric oxide 0.3%; wetting agent 1%; and water 59.2%.
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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) | 1987-03-27 | 1987-09-26 | 1988-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-03-27 | 1991-09-26 | 1992-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-03-27 | 1995-09-26 | 1996-03-27 | $7700.00 | Window Closed / Lapsed |