US4615848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pyroelectric and isotropic piezoelectric polymer blends
Assignee: 3M Co
•
Filing: 1985-02-15
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Granted: 1986-10-07
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Expires: 2005-02-15
Abstract
Abstract A pyroelectric and isotropic piezoelectric polymeric film, the film being formed from a blend of polyvinylidene fluoride and at least one polymer miscible therewith at a temperature above the melting point of the polyvinylidene fluoride, and a process for preparing the film comprising forming the film, heating it to a temperature sufficient to render the film substantially amorphous, cooling at a rate and to a temperature sufficient to prevent crystallization, and polarizing the film to render same pyroelectric and isotropically piezoelectric.
Inventors
- 👤 Dennis L. Krueger
- 👤 Neil W. Loeding
- 👤 Claudia I. Poser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:55
CPC Classifications
H; H10; H10N; H10N15/00; H10N15/10; H10N15/15; H10N30/00; H10N30/01; H10N30/09; H10N30/098
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
125 words
A process for forming a pyroelectric and isotropic piezoelectric polyeric film which has not been mechanically oriented comprising: (a) forming a melt blend by intimately mixing a polymer blend at a sufficient temperature to cause a homogeneous mixture, said polymer blend comprising polyvinylidene flouride and at least one polymer miscible therewith at a temperature above the melting point of said polyvinylidene flouride; (b) forming a film of said melt blend; (c) heating said film to a temperature above the melting point of said polyvinylodiene flouride for a sufficient time to render said film substantially amorphous; (d) cooling said film at a rate and to a temperature sufficient to prevent crystallization of said film; and (e) polarizing said film to render same pyroelectric and isotropically piezoelectric.
Claim 2
Dependent Claim
125 words
A process for forming a pyroelectric and isotropic piezoelectric polyeric film which has not been mechanically oriented comprising: (a) forming a melt blend by intimately mixing a polymer blend at a sufficient temperature to cause a homogeneous mixture, said polymer blend comprising polyvinylidene flouride and at least one polymer miscible therewith at a temperature above the melting point of said polyvinylidene flouride; (b) forming a film of said melt blend; (c) heating said film to a temperature above the melting point of said polyvinylodiene flouride for a sufficient time to render said film substantially amorphous; (d) cooling said film at a rate and to a temperature sufficient to prevent crystallization of said film; and (e) polarizing said film to render same pyroelectric and isotropically piezoelectric.
Claim 3
Dependent Claim
20 words
The process of claim 1 wherein said polyvinylidene fluoride comprises at least about 50 percent by weight of said blend.
Claim 4
Dependent Claim
23 words
The process of claim 1 wherein said polymer is selected from the group consisting of polymers of acrylates, polymers of methacrylates, and polyvinylacetate.
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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) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |