Process of making graphite fiber
US5269984A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 14, 1992 |
| Grant date | Dec 14, 1993 |
| Priority date | — |
| Expiry date | Aug 14, 2012 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F9/22
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A graphite fiber having an elastic modulus E of 340-680 GPa, a microvoid radius of not larger than 20 .ANG. and a crystal size L.sub.c (.ANG.) satisfying the following formula: EQU L.sub.c.sup.3 .ltoreq.0.918.times.10.sup.3 E-3.times.10.sup.5 is valuable for a composite material having an improved compression strength. The graphite fiber is made preferably by oxidizing an acrylonitrile polymer precursor containing 0.05-8 wt. % of comonomer units and having an iodine adsorption amount of not larger than 3 wt. % and an orientation degree of at least 85%, at 200.degree.-300.degree. C. in an oxidative atmosphere under tension to obtain an oxidized fiber having a water adsorption of not larger than 7 wt. % and an orientation degree of at least 78%, followed by carbonization and graphitization of the oxidized fiber under tension.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.