Patent US3855273A successfully refreshed from Google Patents.
US3855273A
Expired / Lapsed
US
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Polyamic acids and esters
Assignee: Raytheon Co
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Filing: 1972-09-05
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Granted: 1974-12-17
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Expires: 1992-09-05
Abstract
Abstract This invention is concerned with an improved polyimide which makes an excellent electrical insulation for metal conductors. It may be used as the insulating layer around the periphery of the metal conductor or as an adhesive for tape used as the insulating layer. The invention is also concerned with a novel prepolymer which is essentially a polyamide in structure and which is readily curable to the corresponding polyimide. The prepolymer is prepared by reacting a tetraalkyl ester of benzophenone tetracarboxylic acid or its anhydride with 1,3-bis(paminophenoxy)benzene.
Inventors
- 👤 N Bilow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:04
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067; C08G73/1071; C08G73/1046; C08G73/105; H; H01; H01B; H01B3/00; H01B3/18; H01B3/30; H01B3/303; H01B3/306; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/31678; Y10T428/31681
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
10 words
A POLYIMIDE PRECURSOR CONSISTING ESSENTIALLY OF TH FOLLOWING RECURRING UNIT:
Claim 2
Dependent Claim
10 words
A POLYIMIDE PRECURSOR CONSISTING ESSENTIALLY OF TH FOLLOWING RECURRING UNIT:
Claim 3
Dependent Claim
18 words
A novel precursor of claim 1 wherein n is an average number from about 1 to about 5.
Claim 4
Dependent Claim
10 words
A novel precursor of claim 2 wherein R is H.
Claim 5
Dependent Claim
10 words
A novel precursor of claim 2 wherein R is ethyl.
Claim 6
Dependent Claim
12 words
A novel precursor of claim 2 wherein the phenyl ether moiety is
Claim 7
Dependent Claim
12 words
A novel precursor of claim 2 wherein the phenyl ether moiety is
Claim 8
Dependent Claim
21 words
A novel precursor of claim 5 wherein R is ethyl and n is an average number from 1 to about 5.
Claim 9
Dependent Claim
21 words
A novel precursor of claim 6 wherein R is ethyl and n is an average number from 1 to about 5.
References Cited (Backward Citations)
US3726831A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |