US4173659A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for manufacturing sensitive elements having a permanent electric polarization
Assignee: IFP Energies nouvelles
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Filing: 1977-07-05
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Granted: 1979-11-06
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Expires: 1997-07-05
Abstract
Abstract The permanent electric polarization is imparted to the sensitive element by electronic bombardment within an enclosure wherein prevails a rarefied atmosphere and in which said bombardment is followed with a coating of the so-polarized sensitive element with a film of liquid of very low saturated vapor pressure whose dielectric strength is higher than that of the rarefied air of the enclosure and having advantageously lubricating properties.
Inventors
- 👤 Jean-Claude Dubois
- 👤 Alain Delaunay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:02
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/02; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49226
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
72 words
A method for manufacturing an electret consisting of placing a substrate of plastic material in an air evacuated enclosure under a high vacuum; subjecting said substrate to electron bombardment to impart thereto a permanent electric polarization; and contacting said substrate in said air-evacuated enclosure after said electron bombardment while maintaining said high vacuum with a liquid of very low saturated vapor pressure whose dielectric strength is higher than that of rarified air.
Claim 2
Independent Claim
72 words
A method for manufacturing an electret consisting of placing a substrate of plastic material in an air evacuated enclosure under a high vacuum; subjecting said substrate to electron bombardment to impart thereto a permanent electric polarization; and contacting said substrate in said air-evacuated enclosure after said electron bombardment while maintaining said high vacuum with a liquid of very low saturated vapor pressure whose dielectric strength is higher than that of rarified air.
Claim 3
Dependent Claim
14 words
A method of manufacture according to claim 1, wherein said liquid exhibits lubricating properties.
Claim 4
Dependent Claim
16 words
A method of manufacture according to claim 1, wherein said liquid coats the substrate after polarization.
Claim 5
Dependent Claim
22 words
A method according to claim 2, wherein the lubricating liquid has a saturated vapor pressure from 5.10 -7 to 10 -7 torr.
Claim 6
Dependent Claim
14 words
A method according to claim 2, wherein the lubricating liquid consists of silicone oil.
References Cited (Backward Citations)
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US2955953A
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US2956899A
Cited
US3755043A
Cited
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Cited
US3664605A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |