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US4634759A
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Fire and heat resistant laminating resins based on maleimido substituted aromatic cyclotriphosphazene polymer
Assignee: National Aeronautics and Space Administration
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Filing: 1985-07-30
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Granted: 1987-01-06
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Expires: 2005-07-30
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 yeilds 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 13:28
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/547; C07F9/6564; C07F9/6581; C07F9/65812; C07F9/65815; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/128; Y; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154; Y10T428/31721; Y10T428/31855
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
77 words
A polymer produced by thermally polymerizing 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 perfluoroamic acid group of the formula ##STR27## the maleimido group of formula (b) or a 2,2,3,3-tetrafluorosuccinylimido group.
Claim 2
Dependent Claim
77 words
A polymer produced by thermally polymerizing 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 perfluoroamic acid group of the formula ##STR27## the maleimido group of formula (b) or a 2,2,3,3-tetrafluorosuccinylimido group.
Claim 3
Dependent Claim
41 words
The polymer of claim 1 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 4
Dependent Claim
80 words
A polymer produced by thermally polymerizing 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 perfluoroamic acid group of the formula ##STR31## the maleimido group of formula (b) or a 2,2,3,3-tetrafluorosuccinylimido group and R 3 is one of the groups ##STR32##
Claim 5
Dependent Claim
80 words
A polymer produced by thermally polymerizing 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 perfluoroamic acid group of the formula ##STR31## the maleimido group of formula (b) or a 2,2,3,3-tetrafluorosuccinylimido group and R 3 is one of the groups ##STR32##
Claim 6
Dependent Claim
9 words
The polymer of claim 3 wherein X is oxygen.
Claim 7
Dependent Claim
38 words
The polymer of claim 4 wherein R 1 and R 2 are each a maleamic acid group of formula (a) or a maleimido group of formula (b), and R 1 and R 2 are each in the 4-positions.
Claim 8
Dependent Claim
44 words
The polymer of claim 4 wherein R 1 and R 2 are different and R 1 is selected from the maleamic acid group of formula (a) or the maleimido group of formula (b), and R 1 and R 2 are each in the 4-positions.
Claim 9
Dependent Claim
10 words
The polymer of claim 6 wherein R 2 is hydrogen.
Claim 10
Dependent Claim
12 words
The polymer of claim 6 wherein R 2 is NH 2 .
Claim 11
Dependent Claim
18 words
The polymer of claim 6 wherein R 2 is an imido group other than that of formula (b).
Claim 12
Dependent Claim
12 words
The polymer of claim 9 wherein R 2 is a 2,2,3,3-tetrafluorosuccinylimido group.
Claim 13
Dependent Claim
12 words
The polymer of claim 9 wherein R 2 is an amido group.
Claim 14
Dependent Claim
87 words
A methof of producing a fire- and heat-resistant polymer comprising: (a) thermally polymerizing the cyclotriphosphazene derivative of claim 1 wherein R 1 and R 2 are independently selected from hydrogen or NH 2 ; (b) reacting the derivative of step (a) with maleic anhydride to form a maleamic acid wherein some or all of the primary amino groups of the derivative of step (a) are converted to maleamic acid groups; (c) converting the maleamic acid groups to maleimide groups, and (d) polymerizing the maleimide of step (c).
Claim 15
Dependent Claim
19 words
The polymer of claim 3 wherein R 1 is the maleimido group of formula (b) and X is oxygen.
Claim 16
Dependent Claim
23 words
A cured resin composite comprising the cured product of an admixture of the polymer resin of claim 1 and a fibrous reinforcing agent.
Claim 17
Dependent Claim
18 words
The cured resin composite of claim 14 wherein the agent is an assembly of plies of graphite cloth.
Claim 18
Dependent Claim
22 words
The cured resin composite comprising the cured product of an admixture of the resin of claim 3 and a fibrous reinforcing agent.
Claim 19
Dependent Claim
18 words
The cured resin composite of claim 16 wherein the agent is an assembly of plies of graphite cloth.
References Cited (Backward Citations)
US4550177A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1990-01-05 | 1990-07-07 | 1991-01-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-01-05 | 1994-07-07 | 1995-01-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-01-05 | 1998-07-07 | 1999-01-06 | $7700.00 | Window Closed / Lapsed |