Mitsubishi Chemical Corporation

Mitsubishi Rayon Company, Limited

Akito Hatayama

Nobuyuki Yamamoto

Hiroshi Hashimoto

Atsushi Nakajima

Naoki Sugiura

Katsuhiko Ikeda

Yusuke Oka

Masahiro Hata

Yasuyuki Fujii

Norifumi Hirota

Kouki Wakabayashi

Kenji Kaneta

Kenji Hirano

Naomasa Matsuyama

Akihiro Itou

Yuutarou Nakamura

Hiroko Matsumura

Tadashi Ootani

Kazunori Sumiya

Takahiro Okuya

A first aspect of the present invention is carbon fiber wherein the surface of a monofilament has a center line average roughness Ra of 6.0 nm or more and 13 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. A second aspect of the present invention is carbon fiber precursor acrylic fiber wherein the surface of a monofilament has a center line average roughness Ra of 18 nm or more and 27 nm or less, and the monofilament has a long diameter/short diameter ratio of 1.11 or more and 1.245 or less. The carbon fiber according to the first aspect is obtained by stabilizing and carbonizing under specific conditions the carbon fiber precursor acrylic fiber according to the second aspect.

Carbon fiber precursor acrylic fiber, carbon fiber, and method for producing same

A carbon fiber manufacturing method with which high quality carbon fibers can be obtained. The carbon fiber manufacturing method includes introducing carbon fiber precursor fiber bundles that have been spread in sheet form into a flameproofing furnace, flameproofing the carbon fiber precursor fiber bundles introduced into the flameproofing furnace in a temperature range of 200&#xb0; C. to 300&#xb0; C., introducing the flameproofed fiber bundles obtained from the flameproofing treatment into a carbonization furnace, and carbonizing the flameproofed fiber bundles introduced into the carbonization furnace in a temperature range of 300&#xb0; C. to 2500&#xb0; C. The flameproofing furnace includes a heat-treatment chamber and a sealing chamber adjacent thereto and discharges air from the sealing chamber to outside of the flameproofing furnace. The space velocity (SV) (1/h) of hot air blown from the heat-treatment chamber into the sealing chamber satisfies relationship: 80&#x2264;SV&#x2264;400.

Carbon fiber manufacturing method

Provided is a carbonization furnace in which disordering of fiber bundles does not occur and there is no lack of uniformity throughout the entire furnace interior, even in the supply of heated inert gas. A carbonization furnace for manufacturing carbon fiber bundles, the furnace being provided with a heat treatment chamber, an inlet sealed chamber and an outlet sealed chamber, a gas spray nozzle, and a conveyance path, wherein: the gas spray nozzle () has a double tube structure obtained from a hollow cylindrical inner tube () and a hollow cylindrical outer tube (), and is disposed in a direction that is horizontal and is orthogonal to the fiber bundle conveyance direction; in the outer tube, multiple gas-spraying holes () are disposed across the width of the conveyance path in the longitudinal direction of the outer tube, and the area of the gas-spraying holes of the outer tube is 0.5 mm2 to 20 mm2; in the inner tube, multiple gas-spraying holes () are disposed across the width of the conveyance path in the longitudinal direction of the inner tube such that the gas-spraying directions of the gas-spraying holes are in two or more directions of the circumferential direction of the inner tube, and the interval of the gas-spraying holes of the inner tube in the longitudinal direction of the inner tube is 300 mm or less.

Carbonization furnace for manufacturing carbon fiber bundle and method for manufacturing carbon fiber bundle

Growing community of inventors

Toyohashi, Japan

Akito Hatayama