EP0018802A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Process for preparing a piezoelectric pyroelectric film, and capacitors, piezoelectric and pyroelectric devices incorporating the film
Assignee: Kureha Corp
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Filing: 1980-04-25
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Granted: —
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Expires: 2000-04-25
Abstract
Abstract Previously, the piezoelectric and pyroelectric properties of polyvinylidene fluoride type films prepared by simultaneously stretching and applying a voltage across the film have not been particularly marked. In order to overcome this problem a piezoelectric pyroelectric polyvinylidene fluoride type film is now prepared by stretching the film (1) between electrodes (3) whilst causing a corona discharge between the electrodes, to thereby polarize the film. The resultant films can be used in piezoelectric or pyroelectric devices or as a dielectric material in capacitors.
Inventors
- 👤 Eiichi Fukada
- 👤 Takeo Furukawa
- 👤 Munehiro Date
- 👤 Toshiaki Takamatsu
- 👤 Ken'ichi Nakamura
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 04:25
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
39 words
A process for preparing a piezoelectric pyroelectric film of a high polymer which process comprises stretching a polyvinylidene fluoride type film (1) disposed between electrodes (3) whilst causing a corona discharge between said electrodes to thereby polarize said film.
Claim 2
Dependent Claim
39 words
A process for preparing a piezoelectric pyroelectric film of a high polymer which process comprises stretching a polyvinylidene fluoride type film (1) disposed between electrodes (3) whilst causing a corona discharge between said electrodes to thereby polarize said film.
Claim 3
Dependent Claim
30 words
A process according to claim 1 wherein the tip of at least one of the electrodes (3) between which the polymeric film is positioned when it is stretched is pointed.
Claim 4
Dependent Claim
18 words
A process according to claim 2, wherein the film (1) is disposed between electrodes (3) having pointed tips.
Claim 5
Dependent Claim
44 words
A process according to any one cfthe preceding claims, wherein a positive voltage is applied to the electrode(s) (3) on one side of the film (1) and a negative voltage is applied to the electrode(s) (3) on the other side of the film (1).
Claim 6
Dependent Claim
18 words
A process according to any one of the preceding claims wherein stretching and polarization is effected below 80°C.
Claim 7
Dependent Claim
18 words
A process according to claim 5 wherein stretching and polarization is effected below 70°C but above room temperature.
Claim 8
Dependent Claim
16 words
A process according to claim 6 wherein stretching and polarization is effected between 30°C and 60°C.
Claim 9
Dependent Claim
20 words
A process according to any one of claims 1 to 7, wherein said film (1) is a vinylidene fluoride homopolymer.
Claim 10
Dependent Claim
22 words
A capacitor incorporating a film prepared by a process as claimed in any one of the preceding claims as a dielectric material.
Claim 11
Dependent Claim
23 words
A piezoelectric device or a pyroelectric device incorporating a film prepared by a process as claimed in any one of the preceding claims.
References Cited (Backward Citations)
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