Process for producing pitch-based carbon fibers
US5061413A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 1990 |
| Grant date | Oct 29, 1991 |
| Priority date | — |
| Expiry date | Apr 27, 2010 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD01F9/155
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A pitch-based carbon fiber having a high strength is produced by (a) treating a heavy oil at a temperature of 370.degree. to 480.degree. C. and a pressure of 2 to 50 kg/cm.sup.2 ; (b) separating and removing insoluble solids from the heat-treated oil so that the insoluble solids content is not higher than 50 ppm; (c) subjecting the oil to thin film distillation at a temperature of 250.degree. to 450.degree. C., a pressure of not higher than 100 mm Hg and a film thickness of not larger than 5 mm; (d) heat-treating the resulting pitch at a temperature of 340.degree. to 450.degree. C. while passing an inert gas at atmospheric or reduced pressure to obtain an optically anisotropic pitch having a softening point of 260.degree. to 300.degree. C., a quinoline insolubles content of not higher than 40 wt % and an optically anisotropic phase content of 60 to 100 vol %; (e) melt-spinning said optically anesotropic pitch in a melt-spinning apparatus having a nozzle with a vertically longer molded product disposed therein, at a temperature of 280.degree. to 360.degree. C. and a spinning viscosity of 300 to 3,000 poise; (f) rendering the resulting pitch fiber infusible and (g) calcining the infu…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.