US4898723A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing high strength, high modulus mesophase-pitch based carbon fibers
Assignee: Petoca Ltd
•
Filing: 1988-06-03
•
Granted: 1990-02-06
•
Expires: 2008-06-03
Abstract
Abstract A method for producing mesophase pitch based carbon fibers which enables to produce high strength high modulus carbon fibers at a relatively low temperature with stabilized production manner. This method comprises carbonizing infusibilized fibers, in an inert atmosphere under no tension state or a tension of 1 mg/denier or less in the first stage to give a specified interlayer spacing and a crystallite thickness and then carbonizing under a tension of 50-300 mg/denier at a temperature of 2600° C. or more in the second stage.
Inventors
- 👤 Yoshinori Suto
- 👤 Toshiyuki Ito
- 👤 Hideyuki Nakajima
- 👤 Keiichiro Okamura
- 👤 Shin-ichi Nayuki
- 👤 Hiroyasu Ogawa
- 👤 Harumitsu Enomoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:54
CPC Classifications
D; D01; D01F; D01F9/00; D01F9/08; D01F9/12; D01F9/14; D01F9/145; D01F9/15; D01F9/155
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
80 words
A method for producing mesophase pitch based carbon fibers which comprises carbonizing infusiblized fibers, obtained by treating mesophase-pitch-fibers, in an inert atmosphere under no tension or under a tension of 1 mg/denier or less in a first stage until an interlayer spacing d 002 of 0.3460-0.3490 nm and a crystallite thickness L c (002) of 1.6-2.2 nm are attained and then carbonizing under a tension of 50-300 mg/denier at the temperature of 2600° C. or more in the second stage.
Claim 2
Independent Claim
80 words
A method for producing mesophase pitch based carbon fibers which comprises carbonizing infusiblized fibers, obtained by treating mesophase-pitch-fibers, in an inert atmosphere under no tension or under a tension of 1 mg/denier or less in a first stage until an interlayer spacing d 002 of 0.3460-0.3490 nm and a crystallite thickness L c (002) of 1.6-2.2 nm are attained and then carbonizing under a tension of 50-300 mg/denier at the temperature of 2600° C. or more in the second stage.
References Cited (Backward Citations)
US3775520A
Cited
US3976746A
Cited
US4100004A
Cited
US4452860A
Cited
US4314981A
Cited
WO1985001752A1
Cited
US4610860A
Cited
US4609540A
Cited
US4705618A
Cited
US4671950A
Cited
US4656022A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-02-05 | 1993-08-07 | 1994-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-05 | 1997-08-07 | 1998-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-05 | 2001-08-07 | 2002-02-06 | $7700.00 | Window Closed / Lapsed |