US4820791A
Expired / Lapsed
US
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Polyimides containing carbonyl and ether connecting groups
Assignee: National Aeronautics and Space Administration
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Filing: 1987-02-05
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Granted: 1989-04-11
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Expires: 2007-02-05
Abstract
Abstract New polyimides have been prepared from the reaction of aromatic dianhydrides with novel aromatic diamines containing carbonyl and ether connecting groups between the aromatic rings. Several of these polyimides were shown to be semi-crystalline as evidenced by wide angle x-ray diffraction and differential scanning calorimetry. Most of the semi-crystalline polyimides form tough solvent resistant films with high tensile properties. One of these materials exhibits very high fracture toughness and can be thermally processed.
Inventors
- 👤 Paul M. Hergenrother
- 👤 Stephen J. Havens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 20:08
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/26; C08G69/32
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
148 words
A high molecular weight linear polyimide having high strength, modulus, toughness, and solvent resistance, the polyimide having the general structural formula: ##STR45## (a) wherein Ar is a radical selected from the group consisting of: ##STR46## wherein Y is not a substituent or is a substituent selected from the group consisting of: O, S, ##STR47## SO 2 , CH 2 , C(CH 3 ) 2 , C(CF 3 ) 2 and Si(CH 3 ) 2 ; (b) wherein Ar' is a radical having the structural formula: ##STR48## wherein R is a radical selected from the group consisting of: ##STR49## wherein Y is not a substituent or is a substituent selected from the group consisting of: O, S, ##STR50## SO 2 , CH 2 , C(CH 3 ) 2 , and C(CF 3 ) 2 , and mixtures thereof; and (c) wherein n is an integer between 4 and 100.
Claim 2
Dependent Claim
148 words
A high molecular weight linear polyimide having high strength, modulus, toughness, and solvent resistance, the polyimide having the general structural formula: ##STR45## (a) wherein Ar is a radical selected from the group consisting of: ##STR46## wherein Y is not a substituent or is a substituent selected from the group consisting of: O, S, ##STR47## SO 2 , CH 2 , C(CH 3 ) 2 , C(CF 3 ) 2 and Si(CH 3 ) 2 ; (b) wherein Ar' is a radical having the structural formula: ##STR48## wherein R is a radical selected from the group consisting of: ##STR49## wherein Y is not a substituent or is a substituent selected from the group consisting of: O, S, ##STR50## SO 2 , CH 2 , C(CH 3 ) 2 , and C(CF 3 ) 2 , and mixtures thereof; and (c) wherein n is an integer between 4 and 100.
Claim 3
Dependent Claim
56 words
A diamine having the general structural formula: ##STR51## wherein R is a radical selected from the group consisting of: ##STR52## wherein Y is not a substituent or is a substituent selected from the group consisting of: O, S, ##STR53## SO 2 , CH 2 , C(CH 3 ) 2 , and C(CF 3 ) 2 .
Claim 4
Dependent Claim
56 words
A diamine having the general structural formula: ##STR51## wherein R is a radical selected from the group consisting of: ##STR52## wherein Y is not a substituent or is a substituent selected from the group consisting of: O, S, ##STR53## SO 2 , CH 2 , C(CH 3 ) 2 , and C(CF 3 ) 2 .
Claim 5
Dependent Claim
24 words
A film from a semi-crystalline polyimide according to claim 1 which is unaffected by immersion in a strong base for up to 18 hours.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |