Patent US4298609A successfully refreshed from Google Patents.
US3676752A
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Aluminum electrolytic capacitor
Assignee: Sprague Electric Co
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Filing: 1971-03-19
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Granted: 1972-07-11
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Expires: 1991-03-19
Abstract
Abstract Undesirable anodic side reactions in aluminum electrolytic capacitors are controlled by employing glycol-based electrolytes which include additives of less than 2 percent of selected alphahydroxy carboxylic acids and their salts.
Inventors
- 👤 Francis J P J Burger
- 👤 Jie Chu Wu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 00:10
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/004; H01G9/022; H01G11/00; H01G11/54; H01G11/58; Y; Y02; Y02E; Y02E60/00; Y02E60/13
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
87 words
An aluminum electrolytic capacitor comprising at least two aluminum electrodes, at least one of said electrodes having a dielectric oxide film thereon, an electrolyte in contact with said electrodes, said electrolyte having a predominantly glycol solVent and a predominantly borate solute, said electrolyte further having an additive of from about 0.02 percent to less than about 2 percent of a member selected from the group consisting of aliphatic alpha-hydroxy carboxylic acids having at least two carboxyl groups, aromatic alpha-hydroxy carboxylic acids, salts thereof, and boron complexes thereof.
Claim 2
Dependent Claim
87 words
An aluminum electrolytic capacitor comprising at least two aluminum electrodes, at least one of said electrodes having a dielectric oxide film thereon, an electrolyte in contact with said electrodes, said electrolyte having a predominantly glycol solVent and a predominantly borate solute, said electrolyte further having an additive of from about 0.02 percent to less than about 2 percent of a member selected from the group consisting of aliphatic alpha-hydroxy carboxylic acids having at least two carboxyl groups, aromatic alpha-hydroxy carboxylic acids, salts thereof, and boron complexes thereof.
Claim 3
Dependent Claim
24 words
The capacitor of claim 1 wherein said additive is selected from the group consisting of citric, tartaric, tartronic and malic acids and salts thereof.
Claim 4
Dependent Claim
27 words
The capacitor of claim 1 wherein said additive is selected from the group consisting of salicylic, 1-hydroxy-2 naphthoic, 2-hydroxy-1 naphthoic, and 2-hydroxy-3 naphthoic acids, and salts thereof.
Claim 5
Dependent Claim
34 words
The capacitor of claim 1 wherein said additive is selected from the group consisting of boron complexes of citric, tartaric, tartronic, malic, salicylic, 1-hydroxy-2 naphthoic, 2-hydroxy-1 naphthoic, and 2-hydroxy-3 naphthoic acids, and salts thereof.
Claim 6
Dependent Claim
30 words
The capacitor of claim 1 wherein said additive is selected from salicylic acid, salts of salicylic acid, boron complexes of salicylic acid, and salts of boron complexes of salicylic acid.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |