US4276344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphorus-containing bisimide resins
Assignee: United States, AS REPRESENTED BY NATIONAL AERONAUTICS AND SPACE ADMINSTRATION
•
Filing: 1980-08-05
•
Granted: 1981-06-30
•
Expires: 2000-08-05
Abstract
Abstract Fire-resistant resins particularly useful for making laminates with inorganic fibers such as graphite fibers, are made by (1) condensation of an ethylenically unsaturated cyclic anhydride with a bis(diaminophenyl)phosphine oxide, and (2) by addition polymerization of the bisimide so obtained. Up to about 50%, on a molar basis, of benzophenonetetracarboxylic acid anhydride can be substituted for some of the cyclic anhydride to alter the properties of the products. Graphite cloth laminates made with these resins have shown 800° C. char yields greater than 70% by weight in nitrogen. Limiting oxygen indexes (LOI) of more than 100% have been determined for these resins, as per ASTM D 2863-4.
Inventors
- 👤 Indra K. Varma
- 👤 George M. Fohlen
- 👤 John A. Parker
- 👤 Robert A. Frosch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:59
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/125; C08L; C08L79/00; C08L79/04; C08L79/08; C08L79/085; Y; Y10; Y10S; Y10S428/00; Y10S428/902; Y10S428/92; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249924; Y10T428/24994; Y10T428/249942; Y10T428/249945; Y10T428/29; Y10T428/2913; Y10T428/2918; Y10T428/30; Y10T442/00; Y10T442/20; Y10T442/2631; Y10T442/2672; Y10T442/268; Y10T442/2926; Y10T442/2984
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
33 words
A bisimide obtained by the condensation reaction of a polymerizable ethylenically unsaturated cyclic anhydride with a phosphorus-containing diamine of the formula ##STR3## in which R stands for a methyl, ethyl, or phenyl group.
Claim 2
Dependent Claim
33 words
A bisimide obtained by the condensation reaction of a polymerizable ethylenically unsaturated cyclic anhydride with a phosphorus-containing diamine of the formula ##STR3## in which R stands for a methyl, ethyl, or phenyl group.
Claim 3
Dependent Claim
24 words
The bisimide of claim 1 wherein the anhydride is selected from the class consisting of maleic anhydride, dichloromaleic anhydride, citraconic anhydride, and mixtures thereof.
Claim 4
Dependent Claim
23 words
The bisimide of claim 2 wherein up to 50% of the molar quantity of the cyclic anhydride is replaced by benzophenonetetracarboxylic acid dianhydride.
Claim 5
Dependent Claim
11 words
The bisimide of claim 2 wherein the diamine is bis(3-aminophenyl)methylphosphine oxide.
Claim 6
Dependent Claim
23 words
A light weight laminate that comprises inorganic fibers embedded in a resin formed by the addition polymerization of the bisimide of claim 1.
Claim 7
Dependent Claim
17 words
The laminte of claim 5 where the inorganic fibers are in the form of a graphite cloth.
References Cited (Backward Citations)
US2444536A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-06-29 | 1984-12-29 | 1985-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-29 | 1988-12-29 | 1989-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-29 | 1992-12-29 | 1993-06-30 | $7700.00 | Window Closed / Lapsed |