US4395557A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phosphorus-containing imide resins
Assignee: National Aeronautics and Space Administration
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Filing: 1981-07-30
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Granted: 1983-07-26
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Expires: 2001-07-30
Abstract
Abstract Bis- and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride. Such monomers or their oligomers may be used to impregnate fibers and fabrics which when cured, are flame resistant. Also an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst.
Inventors
- 👤 Indra K. Varma
- 👤 George M. Fohlen
- 👤 John A. Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:34
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/125; C07; C07F; C07F9/00; C07F9/02; C07F9/547; C07F9/553; C07F9/5537; C08L; C08L79/00; C08L79/04; C08L79/08; C08L79/085
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
35 words
Imides having the structure ##STR6## wherein R 1 and R 2 are selected from the class consisting of chloro, lower alkyls and hydrogen and R 3 is the amino group or an imide group ##STR7##
Claim 2
Dependent Claim
35 words
Imides having the structure ##STR6## wherein R 1 and R 2 are selected from the class consisting of chloro, lower alkyls and hydrogen and R 3 is the amino group or an imide group ##STR7##
Claim 3
Dependent Claim
11 words
Imides of claim 1 wherein R 3 is the amino group.
Claim 4
Dependent Claim
11 words
Imides of claim 1 wherein R 3 is an imide group.
Claim 5
Dependent Claim
13 words
Imides of claim 1 wherein R 1 and R 2 are each hydrogen.
Claim 6
Dependent Claim
68 words
Monomers having the structure ##STR8## wherein R 1 and R 2 are selected from the class consisting of hydrogen chloro, and lower alkyls, R 3 is --NH 2 or the imide group ##STR9## and wherein X is a linking entity selected from the class consisting of a valence bond, --O--, --S--, --C n H 2n -- wherein n is 1, 2 or 3, ##STR10## and --SO 2 --.
Claim 7
Dependent Claim
68 words
Monomers having the structure ##STR8## wherein R 1 and R 2 are selected from the class consisting of hydrogen chloro, and lower alkyls, R 3 is --NH 2 or the imide group ##STR9## and wherein X is a linking entity selected from the class consisting of a valence bond, --O--, --S--, --C n H 2n -- wherein n is 1, 2 or 3, ##STR10## and --SO 2 --.
Claim 8
Dependent Claim
11 words
Monomers of claim 5 wherein R 3 is an amino group.
Claim 9
Dependent Claim
11 words
Monomers of claim 5 wherein R 3 is an imide group.
Claim 10
Dependent Claim
17 words
Monomers of claim 5 wherein R 1 and R 2 are each hydrogen and X is ##STR11##
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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) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |