US4966729A
Expired / Lapsed
US
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Material having a resistivity with a positive temperature coefficient
Assignee: Mersen SA
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Filing: 1988-04-04
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Granted: 1990-10-30
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Expires: 2008-04-04
Abstract
Abstract The invention relates to an electrically conductive, polymer based material with electrical resistivity having a positive temperature coefficient. The material comprises a matrix of thermosetting polymer having conductive particles in the form of fibers distributed through the polymer. The polymer can be an epoxy resin, polyimide, unsaturated polyester, silicone, polyurethane or phenolic resin, and the fibers can be carbon fibers, carbon fibers coated with metal or metal alloy, graphite fibers, graphite fibers coated with metal or metal alloy, graphite intercalation compound fibers, metal fibers, ceramic fibers, or ceramic fibers coated with a metal or metal alloy.
Inventors
- 👤 Francois Carmona
- 👤 Jacques Maire
- 👤 Helene Septier
- 👤 Roland Canet
- 👤 Pierre Delhaes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 08:21
CPC Classifications
B; B29; B29C; B29C65/00; B29C65/02; B29C65/34; B29C65/3404; B29C65/3408; B29C65/3416; B29C65/3472; B29C65/3476; B29C65/3484; B29C65/3488; B29C65/3492; B29C66/00; B29C66/70; B29C66/73; B29C66/739; B29C66/7394; H; H01; H01C; H01C7/00; H01C7/02; H01C7/027
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
64 words
Electrically conductive, polymer based material with electrical resistivity having a positive temperature coefficient, comprising: (a) a matrix of a thermosetting polymer selected from the group consisting of epoxy resins, polyimides, unsaturated polyesters, silicones, polyurethanes and phenolic resins; and said material having electrically resistivity which is substantially constant from about 20° C. up to a defined temperature, and which increases rapidly above the defined temperature.
Claim 2
Dependent Claim
64 words
Electrically conductive, polymer based material with electrical resistivity having a positive temperature coefficient, comprising: (a) a matrix of a thermosetting polymer selected from the group consisting of epoxy resins, polyimides, unsaturated polyesters, silicones, polyurethanes and phenolic resins; and said material having electrically resistivity which is substantially constant from about 20° C. up to a defined temperature, and which increases rapidly above the defined temperature.
Claim 3
Dependent Claim
23 words
Material according to claim 1, wherein the fibres have a diameter of approximately 10 μm and a length of 1 to 3 mm.
Claim 4
Dependent Claim
16 words
Material according to claim 1, wherein said fibers are graphite fibers, coated with nickel or copper.
Claim 5
Dependent Claim
13 words
Material according to claim 1, wherein said ceramic fibers are silicon carbide fibers.
Claim 6
Dependent Claim
123 words
Electrically conductive, polymer based material comprising: (a) a matrix of a thermosetting polymer selected from the group consisting of epoxy resins, polyimides, unsaturated polyesters, silicones, polyurethanes and phenolic resins; and (b) 1 to 3% by volume conductive particles distributed through the matrix, said particles in the form of fibers of length 1-3 mm selected from the group consisting of carbon fibers, carbon fibers coated with metal or metal alloy, graphite fibers, graphite fibers coated with metal or metal alloy, graphite intercalation compound fibers, metal fibers, ceramic fibers, and ceramic fibers coated with a metal or metal alloy, said material having electrically resistivity which is substantially constant from about 20° C. up to a defined temperature, and which increases rapidly above the defined temperature.
Claim 7
Dependent Claim
123 words
Electrically conductive, polymer based material comprising: (a) a matrix of a thermosetting polymer selected from the group consisting of epoxy resins, polyimides, unsaturated polyesters, silicones, polyurethanes and phenolic resins; and (b) 1 to 3% by volume conductive particles distributed through the matrix, said particles in the form of fibers of length 1-3 mm selected from the group consisting of carbon fibers, carbon fibers coated with metal or metal alloy, graphite fibers, graphite fibers coated with metal or metal alloy, graphite intercalation compound fibers, metal fibers, ceramic fibers, and ceramic fibers coated with a metal or metal alloy, said material having electrically resistivity which is substantially constant from about 20° C. up to a defined temperature, and which increases rapidly above the defined temperature.
Claim 8
Dependent Claim
13 words
Material according to claim 5, wherein the defined temperature is about 80°-120° C.
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) | 1993-10-29 | 1994-04-30 | 1994-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-29 | 1998-04-30 | 1998-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-29 | 2002-04-30 | 2002-10-30 | $7700.00 | Window Closed / Lapsed |