Patent US5793276A successfully refreshed from Google Patents.
US5793276A
Expired / Lapsed
US
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Organic PTC thermistor
Assignee: TDK Corp
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Filing: 1996-07-17
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Granted: 1998-08-11
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Expires: 2016-07-17
Abstract
Abstract An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein the conductive substance is tungsten carbide powder; or the electrodes each comprise a metal mesh and a metal layer.
Inventors
- 👤 Hisanao Tosaka
- 👤 Minoru Takaya
- 👤 Shigeru Moriya
- 👤 Hisashi Kobuke
- 👤 Munemitsu Hamada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:06
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/02; H01C7/027; H01C1/00; H01C1/01; H01C1/14; H01C1/1406
Claims Analysis
Total Claims: 31
Claim 1
Independent Claim
41 words
An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein said conductive substance is tungsten carbide powder.
Claim 2
Dependent Claim
41 words
An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein said conductive substance is tungsten carbide powder.
Claim 3
Dependent Claim
23 words
The organic PTC thermistor according to claim 1, wherein said tungsten carbide powder has an average particle size of 0.1 to 10 μm.
Claim 4
Dependent Claim
41 words
An organic PTC thermistor according to claim 1, wherein said organic polymer is at least one polymer selected from the group consisting of polyvinylidene fluoride, polyethylene, polypropylene, polyvinyl chloride, polyvinyl acetate, an ionomer, and a copolymer comprising monomers of these polymers.
Claim 5
Dependent Claim
33 words
An organic PTC thermistor according to claim 1, wherein said tungsten carbide powder is present in an amount of 20 to 50% by volume based on the total volume of the PTC composition.
Claim 6
Dependent Claim
24 words
An organic PTC thermistor according to claim 1, wherein said electrodes each have a structure composed of a metal mesh and a metal layer.
Claim 7
Dependent Claim
29 words
An organic PTC thermistor according to claim 5, wherein said metal mesh is embedded in the surface of said PTC composition, a part of said metal mesh being exposed.
Claim 8
Dependent Claim
21 words
An organic PTC thermistor according to claim 5, wherein said metal mesh has an opening size of 200 to 600 mesh.
Claim 9
Dependent Claim
45 words
An organic PTC thermistor according to claim 5, wherein said metal mesh is at least one of plain weave mesh, twilled weave mesh, plain weave mesh having been squashed, twilled weave mesh having been squashed, and mesh with no difference in level at the intersections.
Claim 10
Dependent Claim
26 words
An organic PTC thermistor according to claim 5, wherein said metal layer is formed by chemical plating, electroplating, vacuum vapor phase deposition or flame spray coating.
Claim 11
Dependent Claim
27 words
An organic PTC thermistor according to claim 5, wherein said metal layer is formed on an abraded surface of said PTC composition inclusive of said metal mesh.
Claim 12
Dependent Claim
24 words
The organic PTC thermistor according to claim 2, wherein said tungsten carbide powder has an average particle size of about 0.1 to 1 μm.
Claim 13
Dependent Claim
24 words
The organic PTC thermistor according to claim 11, wherein said tungsten carbide powder has an average particle size of about 0.5 to 1 μm.
Claim 14
Dependent Claim
25 words
The organic PTC thermistor according to claim 4, wherein said tungsten carbide powder is present in an amount of about 23 to 50% by volume.
Claim 15
Dependent Claim
25 words
The organic PTC thermistor according to claim 13, wherein said tungsten carbide powder is present in an amount of about 25 to 40% by volume.
Claim 16
Dependent Claim
45 words
An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein said electrodes each comprise a metal mesh and a metal layer.
Claim 17
Dependent Claim
45 words
An organic PTC thermistor having a positive temperature coefficient of resistivity, which comprises a PTC composition comprising an organic polymer having dispersed therein a conductive substance, and at least one pair of electrodes, wherein said electrodes each comprise a metal mesh and a metal layer.
Claim 18
Dependent Claim
29 words
An organic PTC thermistor according to claim 15, wherein said metal mesh is embedded in the surface of said PTC composition, a part of said metal mesh being exposed.
Claim 19
Dependent Claim
21 words
An organic PTC thermistor according to claim 15, wherein said metal mesh has an opening size of 200 to 600 mesh.
Claim 20
Dependent Claim
45 words
An organic PTC thermistor according to claim 15, wherein said metal mesh is at least one of plain weave mesh, twilled weave mesh, plain weave mesh having been squashed, twilled weave mesh having been squashed, and mesh with no difference in level at the intersections.
Claim 21
Dependent Claim
26 words
An organic PTC thermistor according to claim 15, wherein said metal layer is formed by chemical plating, electroplating, vacuum vapor phase deposition or flame spray coating.
Claim 22
Dependent Claim
27 words
An organic PTC thermistor according to claim 15, wherein said metal layer is formed on an abraded surface of said PTC composition inclusive of said metal mesh.
Claim 23
Dependent Claim
69 words
The organic PTC thermistor according to claim 15, wherein said organic polymer is at least one member selected from the group consisting of polyvinylidene fluoride, polyethylene, polypropylene, polyvinyl chloride, polyvinyl acetate, an ionomer, and a copolymer comprising monomers of these polymers, and said conductive substance is at least one member selected from the group consisting of carbon black, graphite, carbon fiber, conductive whiskers, metallic particles, and conductive ceramic powder.
Claim 24
Independent Claim
68 words
An apparatus for preventing abnormal overheat of a fluorescent tube comprising a fluorescent tube and an organic PTC thermistor element having a positive temperature coefficient of resistivity which is thermally in contact with said fluorescent tube, said thermistor element comprising a PTC composition comprising an organic polymer having dispersed therein a conductive substance and at least one pair of electrodes, wherein said conductive substance is tungsten carbide powder.
Claim 25
Independent Claim
68 words
An apparatus for preventing abnormal overheat of a fluorescent tube comprising a fluorescent tube and an organic PTC thermistor element having a positive temperature coefficient of resistivity which is thermally in contact with said fluorescent tube, said thermistor element comprising a PTC composition comprising an organic polymer having dispersed therein a conductive substance and at least one pair of electrodes, wherein said conductive substance is tungsten carbide powder.
Claim 26
Dependent Claim
50 words
The apparatus for preventing abnormal overheat of a fluorescent tube according to claim 22, wherein one electrode terminal of said thermistor element and one electrode lead of said fluorescent tube are electrically connected, and said thermistor element is integrated into a lighting circuit of said fluorescent tube with series connection.
Claim 27
Dependent Claim
45 words
The apparatus for preventing abnormal overheat of a fluorescent tube according to claim 22, wherein an increase of resistivity of said thermistor due to abnormal overheat of said fluorescent tube is detected in a detecting circuit dependent of the lighting circuit of said fluorescent tube.
Claim 28
Dependent Claim
30 words
The apparatus for preventing abnormal overheat of a fluorescent tube according to claim 22, wherein said tungsten carbide powder has an average particle size of about 0.1 to 1 μm.
Claim 29
Dependent Claim
30 words
The apparatus for preventing abnormal overheat of a fluorescent tube according to claim 22, wherein said tungsten carbide powder has an average particle size of about 0.5 to 1 μm.
Claim 30
Dependent Claim
31 words
The apparatus for preventing abnormal overheat of a fluorescent tube according to claim 22, wherein said tungsten carbide powder is present in an amount of about 23 to 50% by volume.
Claim 31
Dependent Claim
31 words
The apparatus for preventing abnormal overheat of a fluorescent tube according to claim 22, wherein said tungsten carbide powder is present in an amount of about 25 to 40% by volume.
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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) | 2001-08-10 | 2002-02-09 | 2002-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-08-10 | 2006-02-09 | 2006-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-08-10 | 2010-02-09 | 2010-08-11 | $7700.00 | Window Closed / Lapsed |