US4245278A
Expired / Lapsed
US
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Electrolytic capacitor containing a metatungstate electrolyte
Assignee: Sprague Electric Co
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Filing: 1979-03-21
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Granted: 1981-01-13
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Expires: 1999-03-21
Abstract
Abstract An electrolytic capacitor contains as electrolyte a metatungstate salt dissolved in a polar solvent. The salt is preferably an ammonium or amine salt, and the solvent consists essentially of at least one polar organic solvent and water.
Inventors
- 👤 Manuel Finkelstein
- 👤 Franz S. Dunkl
- 👤 Sidney D. Ross
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:20
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/022
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
58 words
An electrolytic capacitor that retains at least 70% capacity at 40° C. comprising two electrodes at least one of said electrodes having a thin barrier layer dielectric oxide on the surface thereof, and as electrolyte in contact with said electrodes a solution of a metatungstate salt in a polar organic solvent containing 1 to 22 wt percent water.
Claim 2
Dependent Claim
58 words
An electrolytic capacitor that retains at least 70% capacity at 40° C. comprising two electrodes at least one of said electrodes having a thin barrier layer dielectric oxide on the surface thereof, and as electrolyte in contact with said electrodes a solution of a metatungstate salt in a polar organic solvent containing 1 to 22 wt percent water.
Claim 3
Dependent Claim
17 words
An electrolytic capacitor according to claim 1 wherein said metatungstate salt is an ammonium or amine salt.
Claim 4
Dependent Claim
14 words
An electrolytic capacitor according to claim 2 wherein said metatungstate salt is ammonium metatungstate.
Claim 5
Dependent Claim
14 words
An electrolytic capacitor according to claim 2 wherein said metatungstate salt is diethylammonium metatungstate.
Claim 6
Dependent Claim
14 words
An electrolytic capacitor according to claim 2 wherein said metatungstate salt is piperidinium metatungstate.
Claim 7
Dependent Claim
29 words
An electrolytic capacitor according to claim 1 wherein said polar organic solvent is chosen from the group consisting of amides, glycols, lactones, oxazolidones, carbitols, diols, sulfoxides, and mixtures thereof.
Claim 8
Dependent Claim
31 words
An electrolytic capacitor according to claim 6 wherein said polar organic solvent is chosen from the group consisting of ethylene glycol, dimethylformamide, butyrolactone, 3-ethyl-2-oxazolidone, methyl carbitol, 1,2-propanediol, dimethylsulfoxide, and mixtures thereof.
Claim 9
Dependent Claim
63 words
An electrolytic capacitor according to claim 7 wherein said salt is ammonium metatungstate, said polar organic solvent is ethylene glycol, the amount of said metatungstate is in the range of 14 to 50 weight-percent, the amount of said glycol is in the range of 36 to 83 weight-percent, and the amount of said water is in the range of 3 to 22 weight-percent.
Claim 10
Dependent Claim
77 words
An electrolyte capacitor according to claim 7 wherein said salt is ammonium metatungstate, said polar organic solvent is an ethylene glycol-gamma-butyrolactone mixture, the amount of said metatungstate is in the range of 24 to 48 weight-percent, the amount of ethylene glycol is in the range of 6 to 67 weight-percent, the amount of butyrolactone is in the range of 0 to 61 weight-percent, and the amount of water is in the range of 2 to 5 weight-percent.
Claim 11
Dependent Claim
53 words
An electrolytic capacitor according to claim 7 wherein said salt is ammonium metatungstate, said polar organic solvent is N,N-dimethylformamide, the amount of metatungstate is in the range of 5 to 40 weight-percent, the amount of dimethylformamide is 56 to 94 weight-percent, and the amount of water is about 1 weight-percent to 5 weight-percent.
Claim 12
Dependent Claim
14 words
An electrolytic capacitor according to claim 1 wherein said electrode foils are aluminum foils.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-13 | 1984-07-14 | 1985-01-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-13 | 1988-07-14 | 1989-01-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-13 | 1992-07-14 | 1993-01-13 | $7700.00 | Window Closed / Lapsed |