US3784679A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing carbon fibres
Assignee: Charbonnages de France CDF
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Filing: 1971-04-27
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Granted: 1974-01-08
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Expires: 1991-04-27
Abstract
Abstract A PROCESS FOR THE PRODUCTION OF CARBON FIBRES FROM COAL TAR PITCH OR FROM OTHER STRONGLY AROMATIC DISTILLATION RESIDUES SUBJECTED TO HEAT TREATMENT AT A MODERATE TEMPERATURE WHEREIN A HYDROCARBON POLYMER IS ADDED TO THE STARTING MATERIAL BEFORE OR DURING SAID HEAT TREATMENT WHICH IS FOLLOWED BY SPINNING, OXIDIZING, AND CARBONIZING. POLYETHYLENE, POLYPROPYLENE, POLYSTYRENE, POLYBICYCLO (2,2,1)HEPTENE-2, AND RUBBER ARE PREFERRED POLYMERS.
Inventors
- 👤 P Chiche
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:03
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/145; D01F9/15; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
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References Cited (Backward Citations)
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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) | 1977-01-07 | 1977-07-09 | 1978-01-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-07 | 1981-07-09 | 1982-01-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-07 | 1985-07-09 | 1986-01-08 | $7700.00 | Window Closed / Lapsed |