US5344591A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-regulating laminar heating device and method of forming same
Assignee: Individual
•
Filing: 1993-04-01
•
Granted: 1994-09-06
•
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 17:41
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.
References Cited (Backward Citations)
US2715668A
Cited
US3287684A
Cited
US3457537A
Cited
US3793716A
Cited
US4061601A
Cited
US3878362A
Cited
US4658121A
Cited
US4071736A
Cited
US4775778A
Cited
US4250398A
Cited
US4485297A
Cited
US4575620A
Cited
US4761541A
Cited
US4777351A
Cited
US4882466A
Cited
US4857711A
Cited
US4980541A
Cited
US5093036A
Cited
US5077889A
Cited
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 |