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US4550177A
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Maleimido substituted aromatic cyclotriphosphazenes
Assignee: National Aeronautics and Space Administration
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Filing: 1984-04-11
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Granted: 1985-10-29
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Expires: 2004-04-11
Abstract
Abstract 4-Aminophenoxy cyclotriphosphazenes are reacted with maleic anhydride to produce maleamic acids which are converted to the maleimides. The maleimides are polymerized. By selection of starting materials (e.g. hexakis amino or trisaminophenoxy-trisphenoxy-cyclotriphosphazenes), selection of molar proportions of reactants, use of mixtures of anhydrides and use of dianhydrides as bridging groups a variety of maleimides and polymers are produced. The polymers have high limiting oxygen indices, high char yields and other useful heat and fire resistant properties making them useful as, for example, impregnants of fabrics.
Inventors
- 👤 Devendra Kumar
- 👤 George M. Fohlen
- 👤 John A. Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 10:37
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/128; C07; C07F; C07F9/00; C07F9/02; C07F9/547; C07F9/6564; C07F9/6581; C07F9/65812; C07F9/65815; Y; Y10; Y10T; Y10T428/00; Y10T428/31; Y10T428/315
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
72 words
A cyclotriphosphazene derivative having the structure: ##STR24## wherein R 1 is a maleamic acid group of the formula (a) ##STR25## or a maleimido group of the formula (b) ##STR26## X is O or NH and R 2 is selected from the class of hydrogen, primary amino, the maleamic acid group of formula (a), a, a perfluoroamic acid group of the formula ##STR27## the maleimido group of formula (b) and a 2,2,3,3,-tetrafluorosuccinimido group.
Claim 2
Dependent Claim
72 words
A cyclotriphosphazene derivative having the structure: ##STR24## wherein R 1 is a maleamic acid group of the formula (a) ##STR25## or a maleimido group of the formula (b) ##STR26## X is O or NH and R 2 is selected from the class of hydrogen, primary amino, the maleamic acid group of formula (a), a, a perfluoroamic acid group of the formula ##STR27## the maleimido group of formula (b) and a 2,2,3,3,-tetrafluorosuccinimido group.
Claim 3
Dependent Claim
9 words
The derivative of claim 1 wherein X is O.
Claim 4
Dependent Claim
9 words
The derivative of claim 1 wherein X is NH.
Claim 5
Dependent Claim
31 words
The derivative of claim 2 wherein both R 1 and R 2 are maleamic acid groups (a) or maleimido groups (b) and R 1 and R 2 are in the 4-positions.
Claim 6
Dependent Claim
41 words
The derivative of claim 2 wherein R 1 and R 2 are different and R 1 is the maleamic acid group of formula (a) or the maleimido group of formula (b) and R 1 and R 2 are in the 4-positions.
Claim 7
Dependent Claim
75 words
A cyclotriphosphazene derivative having the structure: ##STR28## wherein R 1 is the maleamic acid group (a) ##STR29## or the maleimido group (b) ##STR30## X is O or NH and R 2 is selected from the class of hydrogen, primary amino, the maleamic acid group of formula (a), a, a perfluoroamic acid group of the formula ##STR31## the maleimido group of formula (b) and a 2,2,3,3-tetrafluorosuccinimido group and R 3 is one of the groups ##STR32##
Claim 8
Dependent Claim
75 words
A cyclotriphosphazene derivative having the structure: ##STR28## wherein R 1 is the maleamic acid group (a) ##STR29## or the maleimido group (b) ##STR30## X is O or NH and R 2 is selected from the class of hydrogen, primary amino, the maleamic acid group of formula (a), a, a perfluoroamic acid group of the formula ##STR31## the maleimido group of formula (b) and a 2,2,3,3-tetrafluorosuccinimido group and R 3 is one of the groups ##STR32##
Claim 9
Dependent Claim
17 words
Cyclotriphosphazene derivative of claim 6 wherein R 1 is the maleimido group (b) and X is oxygen.
References Cited (Backward Citations)
US3329663A
Cited
US3280222A
Cited
US3803081A
Cited
US3575924A
Cited
US3671490A
Cited
US3676311A
Cited
US3711389A
Cited
US3962278A
Cited
US3763114A
Cited
DE2350472A1
Cited
US3939228A
Cited
US4082768A
Cited
US4029634A
Cited
US4117041A
Cited
US4094856A
Cited
US4225498A
Cited
US4108805A
Cited
US4225497A
Cited
US4191715A
Cited
US4258172A
Cited
US4288585A
Cited
US4276344A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-10-28 | 1989-04-29 | 1989-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-10-28 | 1993-04-29 | 1993-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-10-28 | 1997-04-29 | 1997-10-29 | $7700.00 | Window Closed / Lapsed |