US4173700A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bis (difluoromaleimide) capped propolymers and polymers
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1978-06-21
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Granted: 1979-11-06
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Expires: 1998-06-21
Abstract
Abstract End-capping an aromatic diamine or a precursor formed by reaction of an aromatic diamine with an aromatic dianhydride with difluoromaleic anhydride yields prepolymers which thermally cure at temperatures from about 150° to about 200° C. to form polymers which display long-term thermal stability at temperatures up to 300° C. and more.
Inventors
- 👤 Howard E. Green
- 👤 Robert J. Jones
- 👤 Michael K. O'Rell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:39
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1057; C08G73/1064; C08G73/1003; C08G73/1007; C08G73/101; C08G73/1014; C08G73/1046; C08G73/1067; C08G73/1071; C08G73/12; C08G73/121; C08G73/122; C08G73/123
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
57 words
Thermally curable prepolymers of the formula: ##STR11## wherein n has a value from 0 to about 3, each R is independently an aromatic radical and R' is a tetra functional radical selected from the group consisting of: ##STR12## wherein R" is a difunctional radical selected from the group consisting of --SO 2 --, --0--, --S--, --CO--, ##STR13##
Claim 2
Dependent Claim
57 words
Thermally curable prepolymers of the formula: ##STR11## wherein n has a value from 0 to about 3, each R is independently an aromatic radical and R' is a tetra functional radical selected from the group consisting of: ##STR12## wherein R" is a difunctional radical selected from the group consisting of --SO 2 --, --0--, --S--, --CO--, ##STR13##
Claim 3
Dependent Claim
34 words
A thermally curable prepolymer as claimed in claim 1 in which R is a aromatic radical of an aromatic diamine selected from the group consisting of 4,4'-diamino-diphenyl methane, meta-phenylene diamine and bis-2,2,-[4-(4-aminophenoxy) phenyl] hexafluoropropane.
Claim 4
Dependent Claim
19 words
A thermally curable prepolymer as claimed in claim 1 in which R' is a radical of bis-2,2-[4-(3,4 dicarboxyphenoxy)phenyl]-hexafluoropropane dianhydride.
Claim 5
Dependent Claim
19 words
A thermally curable prepolymer as claimed in claim 2 in which R' is a radical of bis-2,2-[4-(3,4 dicarboxyphenoxy)phenyl]-hexafluoropropane dianhydride.
Claim 6
Dependent Claim
8 words
A thermally curable prepolymer of the formula: ##STR14##
Claim 7
Dependent Claim
8 words
A thermally curable prepolymer of the formula: ##STR14##
Claim 8
Dependent Claim
8 words
A thermally curable prepolymer of the formula: ##STR15##
Claim 9
Dependent Claim
8 words
A thermally curable prepolymer of the formula: ##STR15##
Claim 10
Dependent Claim
8 words
A thermally curable prepolymer of the formula: ##STR16##
Claim 11
Dependent Claim
8 words
A thermally curable prepolymer of the formula: ##STR16##
Claim 12
Dependent Claim
22 words
A polymer made by the step of thermally curing the prepolymer defined in claims 1, 2, 3, 4, 5, 6 or 7.
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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) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |