US4518651A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Microwave absorber
Assignee: EIDP Inc
•
Filing: 1983-02-16
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Granted: 1985-05-21
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Expires: 2003-02-16
Abstract
Abstract A flexible composite material is disclosed which exhibits a controlled absorption of microwave energy based on presence of particulate carbon in a polymeric matrix bound to a porous substrate. The material is used in packages for microwave cooking. A process for making the material is also disclosed.
Inventors
- 👤 William R. Wolfe, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:21
CPC Classifications
B; B65; B65D; B65D81/00; B65D81/34; B65D81/3446; B65D2581/00; B65D2581/34; B65D2581/3437; B65D2581/3463; B65D2581/3464; B65D2581/3471; B65D2581/3483; B65D2581/3486; B65D2581/3494; Y; Y10; Y10S; Y10S99/00; Y10S99/14; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249953; Y10T428/249955; Y10T428/249959
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
86 words
A composite material for generation of heat by absorption of microwve energy comprising: (a) a porous, dielectric, substrate substantially transparent to microwave radiation; (b) an electrically conductive coating on one surface of the substrate comprising; (i) electrically conductive particles in (ii) a thermoplastic dielectric matrix, wherein, at least some of the matrix is beneath the surface of the substrate, is substantially free of electrically conductive particles, and is intermingled with the substrate; and (c) a protective layer of polyethylene terephthalate adhered to the electrically conductive coating.
Claim 2
Dependent Claim
86 words
A composite material for generation of heat by absorption of microwve energy comprising: (a) a porous, dielectric, substrate substantially transparent to microwave radiation; (b) an electrically conductive coating on one surface of the substrate comprising; (i) electrically conductive particles in (ii) a thermoplastic dielectric matrix, wherein, at least some of the matrix is beneath the surface of the substrate, is substantially free of electrically conductive particles, and is intermingled with the substrate; and (c) a protective layer of polyethylene terephthalate adhered to the electrically conductive coating.
Claim 3
Dependent Claim
91 words
A composite material for generation of heat by absorption of microwave energy comprising: (a) a porous, dielectric paperboard substrate substantially transparent to microwave radiation; (b) a coating on one surface of the substrate comprising: (i) 25 to 60 weight percent finely-divided carbon particles in (ii) 40 to 75 weight percent thermoplastic dielectric matrix, wherein at least some of the matrix is beneath the surface of the substrate, is substantially free of carbon particles, and is intermingled with the substrate; and (c) a protective layer of polyethylene terephthalate adhered to the coating.
Claim 4
Dependent Claim
91 words
A composite material for generation of heat by absorption of microwave energy comprising: (a) a porous, dielectric paperboard substrate substantially transparent to microwave radiation; (b) a coating on one surface of the substrate comprising: (i) 25 to 60 weight percent finely-divided carbon particles in (ii) 40 to 75 weight percent thermoplastic dielectric matrix, wherein at least some of the matrix is beneath the surface of the substrate, is substantially free of carbon particles, and is intermingled with the substrate; and (c) a protective layer of polyethylene terephthalate adhered to the coating.
Claim 5
Dependent Claim
86 words
A process for manufacturing a composite material generation of heat by absorption of microwave energy comprising: (a) providing a porous, dielectric, substrate substantially transparent to microwave radiation; (b) applying to the substrate a coating of a dispersion of finely-divided, electrically conductive, particles in a thermoplastic dielectric matrix; (c) heating the coating and the substrate to a temperature above the softening point of the matrix; and (d) pressing the heated coating against the substrate at a pressure of 600 to 8700 kilopascals for 0.03 to 200 seconds.
Claim 6
Dependent Claim
86 words
A process for manufacturing a composite material generation of heat by absorption of microwave energy comprising: (a) providing a porous, dielectric, substrate substantially transparent to microwave radiation; (b) applying to the substrate a coating of a dispersion of finely-divided, electrically conductive, particles in a thermoplastic dielectric matrix; (c) heating the coating and the substrate to a temperature above the softening point of the matrix; and (d) pressing the heated coating against the substrate at a pressure of 600 to 8700 kilopascals for 0.03 to 200 seconds.
Claim 7
Dependent Claim
30 words
The process of claim 3 wherein the coating is applied to the substrate by first coating a liquid dispersion in a solvent onto the substrate and then evaporating the solvent.
Claim 8
Dependent Claim
43 words
The process of claim 3 wherein the coating is applied to the substrate by first coating a liquid dispersion in a solvent onto a protective layer and evaporating the solvent and then pressing the coated side of the protective layer to the substrate.
Claim 9
Dependent Claim
12 words
The process of claim 5 wherein the protective layer is polyethylene terephthalate.
Claim 10
Dependent Claim
10 words
The process of claim 3 wherein the substrate is paper.
Claim 11
Dependent Claim
12 words
The process of claim 3 wherein the electrically conductive particles are carbon.
References Cited (Backward Citations)
US4391833A
Cited
US4190757A
Cited
GB1595198A
Cited
US4204336A
Cited
EP0000797A1
Cited
US4144438A
Cited
US4144435A
Cited
GB2022977A
Cited
US4267420A
Cited
US4264668A
Cited
US4196331A
Cited
US4304987A
Cited
US4230924A
Cited
US4237441A
Cited
JPS55104648A
Cited
GB2046060A
Cited
DE3010189A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-05-20 | 1988-11-19 | 1989-05-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-05-20 | 1992-11-19 | 1993-05-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-05-20 | 1996-11-19 | 1997-05-21 | $7700.00 | Window Closed / Lapsed |