US4291244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrets
Assignee: Union Carbide Chemicals and Plastics Technology LLC
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Filing: 1979-09-04
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Granted: 1981-09-22
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Expires: 1999-09-04
Abstract
Abstract A process for preparing polymer electrets comprising the following steps: (a) providing two electrodes in a deposition zone, said electrodes being in a spaced relationship to one another, having opposing surfaces, and being connected to an external voltage source capable of impressing an intense electric field between the opposing surfaces; (b) providing a dipolar substituted p-xylylene monomer vapor in sufficient amount to coat the opposing surfaces of the electrodes; (c) activating the power source; and (d) introducing the vapor from step (b) into the deposition zone, said zone being under vacuum and at a temperature at which the vapor will condense, whereby the vapor condenses on the opposing surfaces of the electrodes, the monomer polymerizing to parylene, coating said surfaces, and forming electrets.
Inventors
- 👤 William F. Beach
- 👤 Dennis M. Mahoney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:38
CPC Classifications
H; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/913; Y10S428/922; Y10S428/9265; Y10S428/929; Y10S428/9335; Y10S428/934; Y10S428/938; Y10S55/00; Y10S55/39; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31692; Y10T428/31855
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
135 words
A process for preparing polymer electrets comprising the following steps: (a) providing two electrodes in a deposition zone, said electrodes being in a spaced relationship to one another, having opposing surfaces, and being connected to an external voltage source capable of impressing an intense electric field between the opposing surfaces; (b) providing a dipolar p-xylylene monomer vapor in sufficient amount to coat the opposing surfaces of the electrodes; (c) activating the power source to provide sufficient potential to align the dipoles of the p-xylene monomer coat; and (d) introducing the vapor from step (b) into the deposition zone, said zone being under vacuum and at a temperature at which the vapor will condense, whereby the vapor condenses on the opposing surfaces of the electrodes, the monomer polymerizing to parylene, coating said surfaces, and forming electrets.
Claim 2
Dependent Claim
135 words
A process for preparing polymer electrets comprising the following steps: (a) providing two electrodes in a deposition zone, said electrodes being in a spaced relationship to one another, having opposing surfaces, and being connected to an external voltage source capable of impressing an intense electric field between the opposing surfaces; (b) providing a dipolar p-xylylene monomer vapor in sufficient amount to coat the opposing surfaces of the electrodes; (c) activating the power source to provide sufficient potential to align the dipoles of the p-xylene monomer coat; and (d) introducing the vapor from step (b) into the deposition zone, said zone being under vacuum and at a temperature at which the vapor will condense, whereby the vapor condenses on the opposing surfaces of the electrodes, the monomer polymerizing to parylene, coating said surfaces, and forming electrets.
Claim 3
Dependent Claim
20 words
The process defined in claim 1 wherein the aromatic nucleus of the monomer contains chloro, ortho-dichloro, cyano, or ortho-dicyano radicals.
Claim 4
Dependent Claim
22 words
The process defined in claim 1 wherein fluorine atoms are substituted for the hydrogen atoms of the methylene groups in the monomer.
Claim 5
Dependent Claim
29 words
An electret comprising, in combination, a conductive metal layer coated with a film of a dipolar parylene, said parylene film having aligned electric dipoles and an external electric field.
Claim 6
Dependent Claim
29 words
An electret comprising, in combination, a conductive metal layer coated with a film of a dipolar parylene, said parylene film having aligned electric dipoles and an external electric field.
Claim 7
Dependent Claim
20 words
The electret defined in claim 4 wherein the parylene has chloro, ortho-dichloro, cyano, or ortho-dicyano substituents in its aromatic nucleus.
Claim 8
Dependent Claim
22 words
The electret defined in claim 4 wherein fluorine atoms are substituted for the hydrogen atoms of the methylene groups in the parylene.
Claim 9
Dependent Claim
11 words
An electret consisting essentially of a film of a dipolar parylene.
Claim 10
Dependent Claim
11 words
An electret consisting essentially of a film of a dipolar parylene.
Claim 11
Dependent Claim
22 words
The electret defined in claim 7 wherein fluorine atoms are substituted for the hydrogen atoms of the methylene groups in the parylene.
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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) | 1984-09-21 | 1985-03-23 | 1985-09-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-21 | 1989-03-23 | 1989-09-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-21 | 1993-03-23 | 1993-09-22 | $7700.00 | Window Closed / Lapsed |