Nippon Steel Corporation

Nippon Steel Chemical Co., Ltd.

Kunio Miura

Yutaka Arai

Kazuhiko Mizuuchi

Mitsuaki Matsumoto

Ken Kobayashi

Yasuo Nagata

Hiroyuki Tadokoro

Toshihisa Nishikawa

A method for producing carbon fiber comprising applying an infusibilization to a pitch fiber yarn made using mesophase pitch as a starting material in a state with substantially no tension applied to the yarn and in an oxidizing gas atmosphere including nitrogen dioxide and oxygen, then sintering in an inert gas atmosphere of 350.degree. C. to less than 400.degree. C. for 10 minutes or more for primary carbonization, then applying secondary carbonization at a temperature of 800.degree. to 1300.degree. C. for 5 to 120 seconds, while feeding out the yarn in the linear form and continuously transporting the same.

Method for producing carbon fiber

A bundle of pitch-based carbon fibers which is composed of 1000 to 100,000 continuous fiber filaments having an average diameter of 4 to 8 .mu.m, a filament tensile strength of at least 3.0 GPa, and a modulus of at least 600 GPa, and also a method for producing a fine diameter pitch-based carbon fiber wherein use is made of a spinning nozzle with a single nozzle plate which has at least 1000 capillary holes, has the capillaries arranged concentrically and circularly in 3 to 20 rows, has the capillaries positioned to be divided into at least two blocks, has a columnar projection protruding at least 20 mm from the surface of the nozzle plate at the center of the nozzle plate, and has capillaries of a diameter of 50 to 110 .mu.m.

Small diameter pitch-based carbon fiber bundle and production method

Growing community of inventors

Himeji, Japan

Kunio Miura