Back to results
US 5,348,719 AGranted
Process for producing carbon fibers having high strand strength
AssigneeMitsubishi Kasei Corporation
InventorsIwao Yamamoto, Akihiko Yoshiya, Akira Nakagoshi
Life of this patent
Estimating the term…
Abstract
A process for producing carbon fibers having high strand strength, which comprises subjecting pitch fibers obtained by melt-spinning pitch, followed by gathering, to infusible treatment to obtain infusible fibers, followed by carbonization treatment, and if necessary, graphitization treatment, to obtain carbon fibers, wherein the infusible fibers or the carbon fibers are heat-treated in an atmosphere containing steam or carbon dioxide at a temperature of from 500.degree. to 1,800.degree. C.
Claims9
A process for producing carbon fibers, which consists essentially of:
- preparing pitch fibers by melt-spinning pitch, at least 40% of which is of an optically anisotropic structure;
- gathering the resulting fibers;
- infusibilizing the gathered fibers;
- carbonizing the infusibilized fibers at a temperature of 400.degree. to 1800.degree. C. in an inert gas;
- if necessary, graphitizing said carbonized fibers;
- and
- heat treating said infusibilized fibers or carbonized fibers at a temperature of from 500.degree.-1800.degree. C. in an atmosphere consisting essentially of an inert gas with an effective amount of at least one of steam and carbon dioxide to enhance the tensile strength of the carbon strand product to a level of at least 210 kg/mm.sup.2.
4 more elements
Dependencies are inferred from the claim text.