US3595946A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the production of carbon filaments from coal tar pitch
Assignee: Akzo NV
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Filing: 1968-06-04
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Granted: 1971-07-27
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Expires: 1988-06-04
Abstract
Abstract CARBON FILAMENTS ARE MADE FROM SPECIALLY TREATED HIGH TEMPERATURE COAL TAR PITCH. THE PITCH IS FILTERED, HEAT TREATED AND ITS LOW MOLECULAR WEIGHT COMPONENTS ARE REMOVED BY DISTILLATION. THE TREATED PITCH IS SPUN INTO FILAMENTS, THE FILAMENTS PARTIALLY OXIDIZED AND THEN CARBONIZED UNDER CAREFULLY REGULATED CONDITIONS TO YIELD FILAMENTARY CARBON HAVING A TENSILE STRENGHT OF MORE THAN 100,000 P.S.I. THE FILAMENTS MAY BE GRAPHITIZED.
Inventors
- 👤 Louis A Joo
- 👤 John A Mckee
- 👤 Frederick L Shea
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 13:15
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; D01F9/15; Y; Y10; Y10S; Y10S264/00; Y10S264/19
Claims Analysis
Total Claims: 0
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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) | 1974-07-26 | 1975-01-25 | 1975-07-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-07-26 | 1979-01-25 | 1979-07-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-07-26 | 1983-01-25 | 1983-07-27 | $7700.00 | Window Closed / Lapsed |