Patent FR2090775A5 successfully refreshed from Google Patents.
US4308370A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Piezoelectric and pyroelectric polymer film and process for preparing same
Assignee: Kureha Corp
•
Filing: 1980-04-21
•
Granted: 1981-12-29
•
Expires: 2000-04-21
Abstract
Abstract A process for preparing polyvinylidene fluoride type (PVDF) films having highly stable piezoelectricity and pyroelectricity, by stretching PVDF films, while causing corona discharge, across the electric field formed by discharging, to effect thereby to polarization of film.
Inventors
- 👤 Eiichi Fukada
- 👤 Takeo Furukawa
- 👤 Munehiro Date
- 👤 Toshiaki Takamatsu
- 👤 Ken'ichi Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:09
CPC Classifications
H; H10; H10N; H10N30/00; H10N30/01; H10N30/09; H10N30/098; H01; H01G; H01G7/00; H01G7/02; H01G7/021; H01G7/023; H10N30/04; H10N30/045; H10N30/80; H10N30/85; H10N30/857; Y; Y10; Y10T; Y10T29/00; Y10T29/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
47 words
A process for preparing a piezoelectric pyroelectric film or highpolymer comprising stretching a polyvinylidene fluoride type film, disposed between the electrodes for discharge, while causing corona discharge between said electrodes, across the electric field formed by said discharge, to effect thereby the polarization of said polymeric film.
Claim 2
Dependent Claim
47 words
A process for preparing a piezoelectric pyroelectric film or highpolymer comprising stretching a polyvinylidene fluoride type film, disposed between the electrodes for discharge, while causing corona discharge between said electrodes, across the electric field formed by said discharge, to effect thereby the polarization of said polymeric film.
Claim 3
Dependent Claim
20 words
The process as defined in claim 1, wherein at least one of said electrodes comprises electrode having a pointed top.
Claim 4
Dependent Claim
22 words
The process as defined in claim 2, wherein each of the electrodes comprises an electrode having a configuration of a pointed top.
Claim 5
Dependent Claim
30 words
The process as defined in claim 3, wherein a positive voltage is applied to one of said electrodes and a negative voltage is applied to the other of said electrodes.
Claim 6
Dependent Claim
26 words
The process as defined in any one of claims 1 to 4, wherein the treating temperature in said stretching and polarizing steps is below 80° C.
Claim 7
Dependent Claim
30 words
The process as defined in any one of claims 1 to 4, wherein the treating temperature in said stretching and polarizing steps is below 70° C. and above room temperature.
Claim 8
Dependent Claim
29 words
The process as defined in any one of claims 1 to 4, wherein the treating temperature in said stretching and polarizing steps is between 30° C. and 60° C.
Claim 9
Dependent Claim
25 words
The process as defined in any one of claims 1 to 4, wherein said polymeric film is a polymeric film essentially comprising of polyvinylidene fluoride.
Claim 10
Dependent Claim
49 words
A piezoelectric pyroelectric polymeric film prepared by disposing a polyvinylidene fluoride type film between discharging electrodes at least one of which comprising electrode having a configuration of a pointed top, stretching said polymeric film in transverse to an electric field resulted by continuing corona discharging generated between said electrodes.
Claim 11
Dependent Claim
49 words
A piezoelectric pyroelectric polymeric film prepared by disposing a polyvinylidene fluoride type film between discharging electrodes at least one of which comprising electrode having a configuration of a pointed top, stretching said polymeric film in transverse to an electric field resulted by continuing corona discharging generated between said electrodes.
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) | 1984-12-28 | 1985-06-29 | 1985-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-28 | 1989-06-29 | 1989-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-28 | 1993-06-29 | 1993-12-29 | $7700.00 | Window Closed / Lapsed |