Patent US3995014A successfully refreshed from Google Patents.
US3995014A
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US
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Process for producing carbon fibers from mesophase pitch
Assignee: BP Corp North America Inc
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Filing: 1974-10-31
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Granted: 1976-11-30
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Expires: 1994-10-31
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 subjecting the pitch to reduced pressure during formation of the mesophase.
Inventors
- 👤 Irwin Charles Lewis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:32
CPC Classifications
C; C10; C10C; C10C3/00; C10C3/002; D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; D01F9/32; D01F9/322; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
120 words
In a process for producing a high-modulus, high-strength carbon fiber which comprises spinning a carbonaceous fiber from a nonthixotropic carbonaceous mesophase pitch which under quiescent conditions forms a homogeneous bulk mesophase having large coalesced domains, thermosetting the fiber so produced by heating the fiber in an oxygen-containing atmosphere for a time sufficient to render it infusible, and carbonizing the thermoset fiber by heating it in an inert atmosphere, the improvement which comprises spinning the carbonaceous fiber from a mesophase pitch which has been subjected to a pressure of less than 100 millimeters Hg during formation of the mesophase for a time sufficient to produce a mesophase content of from 40 per cent by weight to 90 per cent by weight.
Claim 2
Dependent Claim
120 words
In a process for producing a high-modulus, high-strength carbon fiber which comprises spinning a carbonaceous fiber from a nonthixotropic carbonaceous mesophase pitch which under quiescent conditions forms a homogeneous bulk mesophase having large coalesced domains, thermosetting the fiber so produced by heating the fiber in an oxygen-containing atmosphere for a time sufficient to render it infusible, and carbonizing the thermoset fiber by heating it in an inert atmosphere, the improvement which comprises spinning the carbonaceous fiber from a mesophase pitch which has been subjected to a pressure of less than 100 millimeters Hg during formation of the mesophase for a time sufficient to produce a mesophase content of from 40 per cent by weight to 90 per cent by weight.
Claim 3
Dependent Claim
21 words
A process as in claim 1 wherein the pitch has been subjected to a pressure of less than 30 millimeters Hg.
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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) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |