US3948788A
Expired / Lapsed
US
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Dielectric composition for impregnating electrical capacitors
Assignee: Monsanto Co
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Filing: 1973-12-13
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Granted: 1976-04-06
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Expires: 1993-12-13
Abstract
Abstract Electrical capacitors are impregnated with liquid dielectric compositions comprising mixtures of diaryl sulfones and halogen-free aromatic organic compounds.
Inventors
- 👤 Ralph H. Munch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:09
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/20; H01G; H01G4/00; H01G4/002; H01G4/018; H01G4/20; H01G4/22; H01G4/221
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
87 words
A composition useful as a capacitor impregnant comprising a mixture of a diaryl sulfone and a halogen-free aromatic organic compound selected from the group consisting of alkyl benzene, alkyl naphthalene, alkyl biphenyl, alkyl polyphenyl, alkaryl ethers and alkyl-substituted derivatives thereof, diaryl alkanes and alkyl-substituted derivatives thereof, and diaryl ethers and alkyl-substituted derivatives thereof wherein said alkyl groups and alkanes have from 1 to about 20 carbon atoms, said aryl radicals are phenyl, naphthyl, biphenyl or polyphenyl and said polyphenyls include from 3 to about 5 phenyl groups.
Claim 2
Dependent Claim
87 words
A composition useful as a capacitor impregnant comprising a mixture of a diaryl sulfone and a halogen-free aromatic organic compound selected from the group consisting of alkyl benzene, alkyl naphthalene, alkyl biphenyl, alkyl polyphenyl, alkaryl ethers and alkyl-substituted derivatives thereof, diaryl alkanes and alkyl-substituted derivatives thereof, and diaryl ethers and alkyl-substituted derivatives thereof wherein said alkyl groups and alkanes have from 1 to about 20 carbon atoms, said aryl radicals are phenyl, naphthyl, biphenyl or polyphenyl and said polyphenyls include from 3 to about 5 phenyl groups.
Claim 3
Dependent Claim
24 words
A composition of claim 1 wherein the diaryl sulfone is present in an amount of from about 10 to about 80 percent by weight.
Claim 4
Dependent Claim
18 words
A composition of claim 2 containing from about 0.001 to 8 percent by weight of an epoxide stabilizer.
Claim 5
Dependent Claim
52 words
A composition of claim 2 wherein the diaryl sulfone is represented by the structure ##EQU2## wherein each Ar is individually a phenyl, naphthyl or indane radical, each R is individually an alkyl radical of 1 to about 8 carbon atoms, and each n is individually an integer of from 0 to 3.
Claim 6
Dependent Claim
12 words
A composition of claim 3 wherein the diaryl sulfone is tolylxylyl sulfone.
Claim 7
Dependent Claim
15 words
A composition of claim 5 wherein the halogen-free aromatic organic compound is benzyl ethyl benzene.
Claim 8
Dependent Claim
14 words
A composition of claim 5 wherein the halogen-free aromatic organic compound is isopropyl biphenyl.
Claim 9
Dependent Claim
29 words
A composition of claim 7 comprising from about 10 to 30 percent by weight of tolylxylyl sulfone and from about 70 to 90 percent by weight of isopropyl biphenyl.
Claim 10
Dependent Claim
16 words
A composition of claim 8 containing from about 0.1 to 3 percent by weight 3,4-epoxycyclohexyl-methyl-3,4-epoxycyclohexane carboxylate.
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) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |