US5968419A
Expired / Lapsed
US
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Conductive polymer compositions, electrical devices and methods of making
Assignee: Westinghouse Electric Co LLC
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Filing: 1997-12-08
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Granted: 1999-10-19
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Expires: 2017-12-08
Abstract
Abstract The present invention is directed to conductive polymer composition that have positive temperature coefficients, electrical devices comprised thereof and methods of making the same. The composition comprises a thermoset polymer matrix containing discretely distributed thermoplastic material and dispersed conductive material. Preferably, the thermoset and thermoplastic polymers are substantially immiscible and have comparable volume transition temperatures, such as bisphenol A liquid epoxy resins and oxidized polyethylene.
Inventors
- 👤 Rajender K. Sadhir
- 👤 Howard E. Saudners
- 👤 Karl F. Schoch, Jr.
- 👤 James D. B. Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:11
CPC Classifications
H; H01; H01B; H01B1/00; H01B1/20; H01B1/22; H01B1/24; H01C; H01C7/00; H01C7/02; H01C7/022
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
52 words
An electrically conductive polymer composition comprising: A polymer matrix having a volume transition temperature and comprising at least one thermoset polymer; thermoplastic material having a volume transition temperature; and, electrically conductive material dispersed in said matrix, wherein said thermoplastic material volume transition temperature is substantially equal to that of said polymer matrix.
Claim 2
Dependent Claim
52 words
An electrically conductive polymer composition comprising: A polymer matrix having a volume transition temperature and comprising at least one thermoset polymer; thermoplastic material having a volume transition temperature; and, electrically conductive material dispersed in said matrix, wherein said thermoplastic material volume transition temperature is substantially equal to that of said polymer matrix.
Claim 3
Dependent Claim
26 words
The composition of claim 1 wherein said thermoplastic material has a crystalline structure and said within 20° C. of the volume transition temperature is polymer matrix.
Claim 4
Dependent Claim
26 words
The composition of claim 1 wherein said thermoplastic material has a crystalline structure and said volume transition temperature corresponds to a crystalline to amorphous transition temperature.
Claim 5
Dependent Claim
18 words
The composition of claim 1 wherein said polymer matrix volume transition temperature corresponds to a glass transition temperature.
Claim 6
Dependent Claim
18 words
The composition of claim 1 wherein said polymer matrix volume transition temperature corresponds to a matrix softening temperature.
Claim 7
Dependent Claim
21 words
The composition of claim 1 wherein said polymer matrix volume transition temperature corresponds to a resistance switching temperature of said composition.
Claim 8
Dependent Claim
15 words
The composition of claim 1 wherein said thermoplastic material is substantially immiscible in said matrix.
Claim 9
Dependent Claim
16 words
The composition of claim 1 wherein said electrically conductive material is dispersed in said thermoplastic material.
Claim 10
Dependent Claim
29 words
The composition of claim 1 wherein: said thermoplastic material is comprised of oxidized polyethylene; and, said polymer matrix is comprised of a bisphenol A epoxy resin based thermoset polymer.
Claim 11
Dependent Claim
37 words
The composition of claim 1 wherein said polymer matrix is comprised of at least one thermoset polymer selected from the group consisting of epoxy resins, polyimides, unsaturated polyesters, silicones, polyurethanes, phenolic resins, cyanate esters and combinations thereof.
Claim 12
Dependent Claim
20 words
The composition of claim 1 wherein said polymer matrix is comprised of a bisphenol A epoxy resin based thermoset polymer.
Claim 13
Dependent Claim
37 words
The composition of claim 11 wherein said thermoplastic material is selected from the group consisting of ethyl cellulose, ethylene/ethyl cellulose, hydroxyethyl cellulose, methyl cellulose, poly(p-tert-butylstyrene), poly(methacrylonitrile), poly(phenylene sulfide), polystyrene, poly(4-vinyldiphenyl), styrene/maleic anhydride, styrene/maleic anhydride and combinations thereof.
Claim 14
Dependent Claim
25 words
The composition of claim 1 wherein said electrically conductive material is selected from the group consisting of carbon, electrically conductive metals, ceramics and combinations thereof.
Claim 15
Dependent Claim
17 words
The composition of claim 1 wherein said electrically conductive material includes at least one electrically conductive metal.
Claim 16
Dependent Claim
34 words
The composition of claim 1 wherein said polymer matrix further comprises additives selected from the group consisting of chemical crosslinking agents, reaction controlling materials, arc controlling materials, thermal conductivity altering materials and combinations thereof.
Claim 17
Dependent Claim
29 words
The composition of claim 15 wherein said chemical crosslinking agents are selected from the group consisting of peroxides, anhydrides, Lewis acids, carboxylic acids, phenolics, amide-imines, amines and combinations thereof.
Claim 18
Dependent Claim
33 words
The composition of claim 1 wherein: said polymer matrix comprises a biphenol A epoxy resin based thermoset polymer; said thermoplastic material comprises oxidized polyethylene particles; and, said electrically conductive material comprises nickel particles.
Claim 19
Dependent Claim
15 words
The composition of claim 11 wherein said thermoplastic material is discretely distributed in said matrix.
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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) | 2002-10-18 | 2003-04-19 | 2003-10-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-10-18 | 2007-04-19 | 2007-10-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-10-18 | 2011-04-19 | 2011-10-19 | $7700.00 | Window Closed / Lapsed |