Patent US3769390A successfully refreshed from Google Patents.
US3769390A
Expired / Lapsed
US
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Process for producing carbon fibres
Assignee: Bayer AG
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Filing: 1971-03-11
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Granted: 1973-10-30
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Expires: 1991-03-11
Abstract
Abstract CARBON FIBERS ARE PRODUCED BY HEAT-TREATING POLYACRYLONITRILE FIBRES IN AN OXIDIZING ATMOSPHERE AT A TEMPERATURE BETWEEN 150*C. TO 400*C. FOLLOWED BY CARBONISING AT A TEMPERATURE OF OVER 400*C. IN A CARBONISING ATMOSPHERE CONTAINING 0.5-20% BY VOLUME WATER VAPOUR. IN A PREFERRED EMBODIMENT, WATER VAPOUR IS PROVIDED TO THE CARBONISING ATMOSPHERE BY PASSING THE FIBROUS MATERIAL THROUGH WATER OR A LIQUID CONTAINING WATER BETWEEN THE OXIDATIVE HEAT TREATMENT AND THE CARBONISATION.
Inventors
- 👤 R Weisbeck
- 👤 G Pampus
- 👤 C Suling
- 👤 L Prets
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:59
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/20; D01F9/21; D01F9/22; D01F9/32
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |