Patent US4423191A successfully refreshed from Google Patents.
US4423191A
Expired / Lapsed
US
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High frequency electric field curing of polymeric composites
Assignee: Massachusetts Institute of Technology
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Filing: 1981-05-01
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Granted: 1983-12-27
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Expires: 2001-05-01
Abstract
Abstract A method for curing a resinous composition comprising an admixture of a thermosetting resin and dielectrically lossy particles is described wherein the lossy particles have a dielectric constant substantially the same as the dielectric constant of the resin. The method comprises subjecting said admixture to a high frequency alternating electric field for sufficient time to heat the lossy particles and initiate the chemical reaction to cure the resin. Also described are shaped articles of manufacture made by curing resinous compositions in accord with the described method. Such articles have enhanced mechanical properties due to the curing process.
Inventors
- 👤 Richard E. Haven
- 👤 Nam P. Suh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:28
CPC Classifications
C; C08; C08J; C08J3/00; C08J3/28; C08L; C08L67/00; C08L67/06
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
65 words
A method for curing a resinous composition comprising an admixture of a thermosetting resin and dielectrically lossy particles, said lossy particles having a dielectric constant substantially the same as the dielectric constant of the resin, said method comprising subjecting said admixture to a high frequency alternating electric field for sufficient time to heat the lossy particles and initiate the chemical reaction to cure the resin.
Claim 2
Independent Claim
65 words
A method for curing a resinous composition comprising an admixture of a thermosetting resin and dielectrically lossy particles, said lossy particles having a dielectric constant substantially the same as the dielectric constant of the resin, said method comprising subjecting said admixture to a high frequency alternating electric field for sufficient time to heat the lossy particles and initiate the chemical reaction to cure the resin.
Claim 3
Dependent Claim
25 words
The method of claim 1 wherein the admixture is placed in a mold and maintained under pressure during the period required to cure the resin.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the electric field has a strength of at least 500 V/cm in the admixture.
Claim 5
Dependent Claim
15 words
The method of claim 1 wherein the electric field strength is at least 2000 V/cm.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein said electric field induces substantially uniform heating of the admixture.
Claim 7
Dependent Claim
18 words
The method of claim 1 wherein the electric field has a frequency of at least about 1 MHz.
Claim 8
Dependent Claim
23 words
The method of claim 1 wherein the electric field as a frequency in the range of from about 1 to about 100 MHz.
Claim 9
Dependent Claim
24 words
The method of claim 1 wherein the electric field has a frequency in the range of from about 900 MHz to about 30 GiHz.
Claim 10
Dependent Claim
11 words
The method of claim 1 wherein the resin is a polyester.
Claim 11
Dependent Claim
24 words
The method of claim 1 wherein the lossy particles are present in the admixture in an amount of at least about 1% by volume.
Claim 12
Dependent Claim
26 words
The method of claim 1 wherein the lossy particles are present in the admixture in an amount of from about 1% to about 10% by volume.
Claim 13
Dependent Claim
11 words
The method of claim 1 wherein said lossy particles comprise polyvinylchloride.
Claim 14
Dependent Claim
14 words
The method of claim 1 wherein said resin additionaly comprises non-lossy fillers or pigments.
Claim 15
Dependent Claim
19 words
The method of claim 1 wherein said lossy particles comprise a non-lossy particle coated with a highly lossy material.
Claim 16
Dependent Claim
28 words
The method of claim 1 wherein the ratio of the dielectric constant of the lossy particle to the dielectric constant of the resin is less than about 10.
Claim 17
Dependent Claim
11 words
The method of claim 15 wherein said ratio is about 1.
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) | 1986-12-26 | 1987-06-27 | 1987-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-26 | 1991-06-27 | 1991-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-26 | 1995-06-27 | 1995-12-27 | $7700.00 | Window Closed / Lapsed |