Patent US4568733A successfully refreshed from Google Patents.
US4568733A
Expired / Lapsed
US
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High performance mixed bisimide resins and composites based thereon
Assignee: HC Chem Research and Service Corp
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Filing: 1985-04-04
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Granted: 1986-02-04
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Expires: 2005-04-04
Abstract
Abstract The present invention relates to mixed bismaleimide/biscitraconimide resins. Mixtures of the two resins produces materials which have better handling, processing or mechanical and thermal properties, particularly in graphite composites, than materials made with the individual resins. The mechanical strength of cured graphite composites prepared from a 1:1 copolymer of such bisimide resins is excellent at both ambient and elevated temperatures. The copolymer mixture provides improved composites which are lighter than metals and replace metals in many aerospace applications.
Inventors
- 👤 John A. Parker
- 👤 Alvin H. Heimbuch
- 👤 Ming-Ta S. Hsu
- 👤 Timothy S. Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 13:38
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/12; C08G73/126; C08F; C08F222/00; C08F222/36; C08F222/40; C08F222/406; Y; Y10; Y10T; Y10T428/00; Y10T428/30; Y10T428/31504; Y10T428/31721
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
63 words
A cured copolymeric resin, having improved physical and chemical properties compared to a resin comprising a single bismaleimide, which resin is formed by curing an admixture comprising a bismaleimide of the structure: ##STR4## and a substantially equimolar amount of biscitraconimide of the structure: ##STR5## wherein Ar is an arylene, wherein the molar ratio of bismaleimide to biscitraconimide is between about 2:1 and 1:2.
Claim 2
Dependent Claim
63 words
A cured copolymeric resin, having improved physical and chemical properties compared to a resin comprising a single bismaleimide, which resin is formed by curing an admixture comprising a bismaleimide of the structure: ##STR4## and a substantially equimolar amount of biscitraconimide of the structure: ##STR5## wherein Ar is an arylene, wherein the molar ratio of bismaleimide to biscitraconimide is between about 2:1 and 1:2.
Claim 3
Dependent Claim
17 words
The cured resin of claim 1 wherein the molar ratio of bismaleimide to biscitraconimide is about 1:1.
Claim 4
Dependent Claim
21 words
The cured copolymeric resin of claim 1 wherein Ar is selected from phenylene, diphenylene, bis(phenylene)methane, diphenylene sulfone, oxyphenylene and amide-linked polyaromatics.
Claim 5
Dependent Claim
12 words
The cured copolymeric resin of claim 1 wherein Ar is bisphenylene methane.
Claim 6
Dependent Claim
12 words
The cured copolymeric resin of claim 1 wherein Ar is a phenylene-benzamide.
Claim 7
Dependent Claim
60 words
A cured copolymeric resin, having improved physical and chemical properties compared to a resin comprising a single bismaleimide, which resin is formed by curing an admixture of bismaleimide of the structure: ##STR6## and a substantially equimolar amount of citraconimide of the structure: ##STR7## wherein the molar ratio of said admixture of bismaleimide to biscitraconimide is between about 2:1 and 1:2.
Claim 8
Dependent Claim
60 words
A cured copolymeric resin, having improved physical and chemical properties compared to a resin comprising a single bismaleimide, which resin is formed by curing an admixture of bismaleimide of the structure: ##STR6## and a substantially equimolar amount of citraconimide of the structure: ##STR7## wherein the molar ratio of said admixture of bismaleimide to biscitraconimide is between about 2:1 and 1:2.
Claim 9
Dependent Claim
12 words
The cured resin of claim 6 wherein the molar ratio about 1:1.
Claim 10
Dependent Claim
26 words
A reinforced resin composite comprising 0.5 to 5 parts of reinforcing fiber dispersed in one part by weight of the cured copolymeric resin of claim 1.
Claim 11
Dependent Claim
24 words
A reinforced resin composite comprising 0.5 to 5 parts of reinforcing fiber dispersed in one part of the cured copolymeric resin of claim 1.
Claim 12
Dependent Claim
24 words
A reinforced resin composite comprising 0.5 to 5 parts of reinforcing fiber dispersed in one part of the cured copolymeric resin of claim 6.
Claim 13
Dependent Claim
25 words
The reinforced resin composite of claim 10 wherein the reinforcing fiber is selected from the group consisting of carbon fibers, glass fibers and aramide fibers.
Claim 14
Dependent Claim
14 words
The reinforced resin composite of claim 8 wherein the reinforcing fiber is carbon fiber.
Claim 15
Dependent Claim
14 words
The reinforced resin composite of claim 11 wherein the reinforcing fiber is carbon fiber.
Claim 16
Dependent Claim
12 words
An aircraft structural panel comprising the reinforced resin composite of claim 8.
Claim 17
Dependent Claim
12 words
An aircraft structural panel comprising the reinforced resin composite of claim 13.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |