US4935156A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Conductive polymer compositions
Assignee: Tyco International Ltd Bermuda
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Filing: 1982-09-27
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Granted: 1990-06-19
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Expires: 2002-09-27
Abstract
Abstract Conductive polymer compositions based on polyvinylidene fluoride have improved properties when the polyvinylidene fluoride has a very regular structure which can be characterized by a low head-to-head content in the repeating units. The improved properties include electrical stability when contacted by organic fluids and/or when maintained at elevated temperatures in air. Such compositions which exhibit PTC behavior are particularly useful in the form of self-limiting heaters which are immersed in organic fluids, especially flexible strip heaters for heating diesel fuel before it passes through a fuel filter.
Inventors
- 👤 Peter H. van Konynenburg
- 👤 Andrew Au
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:27
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/146; H01; H01B; H01B1/00; H01B1/20; H01B1/24; H01C; H01C7/00; H01C7/02; H01C7/027; F; F02; F02B; F02B3/00; F02B3/06
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
48 words
A conductive polymer composition which comprises carbon black dispersed in a polymeric component which consists essentially of 65 to 100% by weight of a crystalline polyvinylidene fluoride which has a head-to-head content of less than 5.0%, and 0 to 35% by weight of at least one elastomeric polymer.
Claim 2
Dependent Claim
48 words
A conductive polymer composition which comprises carbon black dispersed in a polymeric component which consists essentially of 65 to 100% by weight of a crystalline polyvinylidene fluoride which has a head-to-head content of less than 5.0%, and 0 to 35% by weight of at least one elastomeric polymer.
Claim 3
Dependent Claim
18 words
A composition according to claim 1 wherein the polyvinylidene fluoride has a head-to-head content of less than 4.5%.
Claim 4
Dependent Claim
18 words
A composition according to claim 2 wherein the polyvinylidene fluoride has a head-to-head content of less than 4.0%.
Claim 5
Dependent Claim
20 words
A composition according to claim 1 which contains an amount of carbon black such that the composition exhibits PTC behavior.
Claim 6
Independent Claim
68 words
A device which comprises (i) a conductive polymer element comprising carbon black dispersed in a polymeric component which consists essentially of 65 to 100% by weight of a crystalline polyvinylidene fluoride which has a head-to-head content of less than 5%, and 0 to 35% by weight of at least one elastomeric polymer; and (ii) at least one electrode which is in electrical contact with the conductive polymer element.
Claim 7
Independent Claim
68 words
A device which comprises (i) a conductive polymer element comprising carbon black dispersed in a polymeric component which consists essentially of 65 to 100% by weight of a crystalline polyvinylidene fluoride which has a head-to-head content of less than 5%, and 0 to 35% by weight of at least one elastomeric polymer; and (ii) at least one electrode which is in electrical contact with the conductive polymer element.
Claim 8
Dependent Claim
18 words
A device according to claim 5 wherein the polyvinylidene fluoride has a head-to-head content of less than 4.5%.
Claim 9
Dependent Claim
18 words
A device according to claim 6 wherein the polyvinylidene fluoride has a head-to-head content of less than 4.0%.
Claim 10
Dependent Claim
30 words
A device according to claim 5 which is a self-regulating heater in which the conductive polymer composition comprises an amount of carbon black such that the composition exhibits PTC behavior.
Claim 11
Dependent Claim
32 words
A device according to claim 6 which comprises at least two electrodes which can be connected to a source of electrical power to cause current to flow through the conductive polymer element.
Claim 12
Dependent Claim
16 words
A device according to claim 6 wherein the polyvinylidene fluoride is a homopolymer of vinylidene fluoride.
Claim 13
Dependent Claim
16 words
A device according to claim 6 which contains 16 to 25% by weight of carbon black.
Claim 14
Dependent Claim
16 words
A composition according to claim 1 where the polyvinylidene fluoride is a homopolymer of vinylidene fluoride.
Claim 15
Dependent Claim
38 words
A composition according to claim 1 wherein the polyvinylidene fluoride is a copolymer of vinylidene fluoride and a comonomer which is present in amount up to 15% by weight and which is selected from tetrafluoroethylene, hexafluoropropylene and ethylene.
Claim 16
Dependent Claim
29 words
A composition according to claim 1 in which the polymeric ingredients consist essentially of the polyvinylidene fluoride and 0 to 20% by weight of at least one elastomeric polymer.
Claim 17
Dependent Claim
16 words
A composition according to claim 1 which contains 16 to 25% by weight of carbon black.
Claim 18
Dependent Claim
10 words
A composition according to claim 1 which has been cross-linked.
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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) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |