Patent US5344591A successfully refreshed from Google Patents.
US5344591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-regulating laminar heating device and method of forming same
Assignee: Individual
•
Filing: 1993-04-01
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Granted: 1994-09-06
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Expires: 2013-04-01
Abstract
Abstract A positive temperature coefficient composition comprising a dispersion of conductive particles in a solvated or solvatable crystalline organic polymer is disclosed. Temperature self-regulating devices incorporating the composition and related method of manufacture are described.
Inventors
- 👤 Jack H. Smuckler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 17:47
CPC Classifications
B; B60; B60R; B60R1/00; B60R1/02; B60R1/06; B60R1/0602; B60S; B60S1/00; B60S1/02; B60S1/023; B60S1/026; H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/146; H05B3/84; H05B3/845
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
109 words
A PTC composition comprising: a. a continuous, single phase solution comprising (1) greater than 10% by weight of a crystalline polyurethane or polychloroprene polymer having a degree of crystallinity of at least 5%, and (ii) an organic solvent or solvent blend, wherein said polymer remains soluble in said solvent or solvent blend at a temperature in the range of from about 60° F. to about 80° F.; and b. electrically conductive particulate material dispersed throughout said single phase solution in an amount of from about 20% to about 60% by weight, wherein said composition when dried has a switching temperature which approximates the crystalline melt temperature of the polymer.
Claim 2
Dependent Claim
109 words
A PTC composition comprising: a. a continuous, single phase solution comprising (1) greater than 10% by weight of a crystalline polyurethane or polychloroprene polymer having a degree of crystallinity of at least 5%, and (ii) an organic solvent or solvent blend, wherein said polymer remains soluble in said solvent or solvent blend at a temperature in the range of from about 60° F. to about 80° F.; and b. electrically conductive particulate material dispersed throughout said single phase solution in an amount of from about 20% to about 60% by weight, wherein said composition when dried has a switching temperature which approximates the crystalline melt temperature of the polymer.
Claim 3
Dependent Claim
19 words
The composition of claim 1 wherein the degree of crystallinity of the crystalline polymer is determined by x-ray diffraction.
Claim 4
Dependent Claim
14 words
The composition of claim 1 wherein said electrically conductive particulate material comprises carbon black.
Claim 5
Dependent Claim
19 words
The composition of claim 1 wherein said electrically conductive particulate material is a blend of carbon black and graphite.
Claim 6
Dependent Claim
28 words
The composition of claim 3 wherein said electrically conductive particulate material is low structure carbon black having a DBP absorption less than 100 cc/100 g of carbon black.
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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) | 1997-09-05 | 1998-03-07 | 1998-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-05 | 2002-03-07 | 2002-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-05 | 2006-03-07 | 2006-09-06 | $7700.00 | Window Closed / Lapsed |