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US4554024A
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Method for preparing an improved pitch impregnant for a carbon-carbon composite
Assignee: United States, UNITED STATES AIR FORCE, Secretary of
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Filing: 1984-02-13
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Granted: 1985-11-19
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Expires: 2004-02-13
Abstract
Abstract A pitch fraction for impregnating a carbon fiber reinforcing structure which represents the portion of a pitch which is insoluble in cyclohexane and soluble in pyridine. Also provided is a carbon fiber-reinforced carbon-carbon composite made by impregnating a multidirectional carbon fiber reinforcing structure with the above-described pitch fraction, carbonizing the pitch and graphitizing the resulting structure.
Inventors
- 👤 James E. Zimmer
- 👤 Linda M. Salvador
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:44
CPC Classifications
C; C04; C04B; C04B35/00; C04B35/71; C04B35/78; C04B35/80; C04B35/83; Y; Y10; Y10T; Y10T428/00; Y10T428/30
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
62 words
In a process for producing a carbon fiber-reinforced carbon-carbon composite comprising the steps of impregnating a multidirectional carbon fiber reinforcing structure with a pitch, carbonizing said pitch and graphitizing the resulting structure, the improvement which comprises solvent extracting said pitch sequentially with cyclohexane and pyridine and impregnating said reinforcing structure with the fraction which is insoluble in cyclohexane and soluble in pyridine.
Claim 2
Dependent Claim
62 words
In a process for producing a carbon fiber-reinforced carbon-carbon composite comprising the steps of impregnating a multidirectional carbon fiber reinforcing structure with a pitch, carbonizing said pitch and graphitizing the resulting structure, the improvement which comprises solvent extracting said pitch sequentially with cyclohexane and pyridine and impregnating said reinforcing structure with the fraction which is insoluble in cyclohexane and soluble in pyridine.
Claim 3
Dependent Claim
15 words
The process of claim 1 wherein said carbon fiber reinforcing structure is a 223 composite.
Claim 4
Dependent Claim
12 words
The process of claim 1 wherein said pitch is a petroleum pitch.
Claim 5
Dependent Claim
12 words
The process of claim 1 wherein said pitch is a coal-tar pitch.
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) | 1988-11-18 | 1989-05-20 | 1989-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-11-18 | 1993-05-20 | 1993-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-11-18 | 1997-05-20 | 1997-11-19 | $7700.00 | Window Closed / Lapsed |