US4026788A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing mesophase pitch
Assignee: BP Corp North America Inc
•
Filing: 1973-12-11
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Granted: 1977-05-31
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Expires: 1993-12-11
Abstract
Abstract An improved process for producing carbon fibers from pitch which has been transformed, in part, to a liquid crystal or so-called "mesophase" state. According to the process, pitch of a given mesophase content, suitable for producing carbon fibers, is produced in substantially shorter periods of time than heretofore possible, at a given temperature, by passing an inert gas through the pitch during formation of the mesophase.
Inventors
- 👤 Edgar Ronald McHenry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:23
CPC Classifications
C; C10; C10C; C10C3/00; C10C3/002; D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
72 words
A process for producing a mesophase pitch which comprises heating a carbonaceous pitch in an inert atmosphere at a temperature of from 350° C. to 450° C. for a time sufficient to produce a mesophase content of from 40 percent by weight to 90 percent by weight while passing an inert gas through the pitch during formation of the mesophase at a rate of at least 0.5 scfh. per pound of pitch.
Claim 2
Dependent Claim
72 words
A process for producing a mesophase pitch which comprises heating a carbonaceous pitch in an inert atmosphere at a temperature of from 350° C. to 450° C. for a time sufficient to produce a mesophase content of from 40 percent by weight to 90 percent by weight while passing an inert gas through the pitch during formation of the mesophase at a rate of at least 0.5 scfh. per pound of pitch.
Claim 3
Dependent Claim
41 words
A process as in claim 1 wherein the pitch is heated at a temperature of from 380° C. to 440° C. for a time sufficient to produce a mesophase content of from 50 percent by weight to 65 percent by weight.
Claim 4
Dependent Claim
28 words
A process as in claim 2 wherein the inert gas is passed through the pitch at a rate of 0.7 scfh. to 5.0 scfh. per pound of pitch.
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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) | 1980-05-30 | 1980-11-29 | 1981-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-30 | 1984-11-29 | 1985-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-30 | 1988-11-29 | 1989-05-31 | $7700.00 | Window Closed / Lapsed |