Patent US6043865A successfully refreshed from Google Patents.
Patent US4855391A successfully refreshed from Google Patents.
US4855391A
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High temperature stable polyetherimides from oxydiphthalic dianhydride and a mixture of m- and p-phenylene diamines and diaminodiphenyl ether
Assignee: General Electric Co
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Filing: 1988-06-03
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Granted: 1989-08-08
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Expires: 2008-06-03
Abstract
Abstract Polyetherimides are prepared from at least two diamines selected from the group consisting of o-phenylenediamine, m-phenylenediamine and 4-aminophenyl ether and a dicarboxyphenyl ether anhydride, or the esterification product thereof with a low molecular weight alkanol such as methanol. 3,4-Dicarboxyphenyl ether dianhydride is preferred. Said polyimides are tough, flexible and stable at high temperatures.
Inventors
- 👤 Donald R. Berdahl
- 👤 James A. Cella
- 👤 Gary K. Shank
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 19:11
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1067; C08G73/1071; C08G73/1003; C08G73/1007; C08G73/1028; C08G73/1042
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
33 words
A polyetherimide which is free from olefinic groups and which consists essentially of structural units of at least two of the formulas ##STR3## each present in the proportions of about 25-75% by number.
Claim 2
Dependent Claim
33 words
A polyetherimide which is free from olefinic groups and which consists essentially of structural units of at least two of the formulas ##STR3## each present in the proportions of about 25-75% by number.
Claim 3
Dependent Claim
16 words
A polyetherimide according to claim 1 which consists essentially of structural units having the formulas ##STR4##
Claim 4
Dependent Claim
16 words
A polyetherimide according to claim 1 which consists essentially of structural units having the formulas ##STR5##
References Cited (Backward Citations)
US3312663A
Cited
US3326851A
Cited
US3349061A
Cited
US3376260A
Cited
US3700649A
Cited
US3745149A
Cited
US4720539A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |