Patent US3705236A successfully refreshed from Google Patents.
US3705236A
Expired / Lapsed
US
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Method of producing carbon fibers
Assignee: Nippon Carbon Co Ltd
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Filing: 1970-10-28
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Granted: 1972-12-05
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Expires: 1990-10-28
Abstract
Abstract A METHOD IS PROVDED FOR PRODUCING CARBON FIBERS HAVING A TENSILE STRENGTH OF MORE THAN 150 KG./MM.2 AND A YOUNG''S MODULUS OF MORE THAN 32,000 KG./MM.2 BY APPLYING A VIBRATIONAL ENERGY TO ORGANIC FIBERS UNDER A TENSION IN AT LEAST ONE OF A DRAWING STEP FOR OBTAINING THE PRECURSOR SUITABLE FOR THE PRODUCTION OF CARBON FIBERS, A PRETREATMENT STEP FOR FACILITATING CARBONIZATION OF THE PRECURSOR, A CARBONIZATION STEP FOR SUBSTANTIALLY CARBONIZING THE PRECURSOR AND A GRAPHITIZATION STEP FOR GRAPHITIZING THE CARBONIZED FOBERS AND FOR IMPROVING YOUNG''S MODULUS.
Inventors
- 👤 Toshikatsu Ishikawa
- 👤 Haruo Teranishi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:19
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-05 | 1976-06-05 | 1976-12-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-05 | 1980-06-05 | 1980-12-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-05 | 1984-06-05 | 1984-12-05 | $7700.00 | Window Closed / Lapsed |