Nippon Oil Company

Shinagawa Refractories Co., Ltd.

Takao Hirose

Seiichi Uemura

Hiroaki Takashima

Makoto Sasaki

Shunichi Yamamoto

Yoshio Sohda

Syunichi Yamamoto

Takayoshi Sakamoto

Osamu Kato

Sakuya Iwai

Minoru Nagai

Kenji Katoh

Hajime Asami

Tadashi Zenbutsu

Kazuyoshi Okamoto

Yoshio Shohda

Minoru Nagi

Yoshio Kishimoto

Osami Kato

Osamu Katoh

In a process for producing carbon fibers from a carbonaceous pitch, the improvement characterized in that an end portion of infusiblized fiber or carbonized fiber to be first subjected to a carbonizing or graphitizing treatment and that of infusiblized fiber or carbonized fiber to be next subjected to the same treatment are bonded together using a composition comprising (a) at least one member selected from the group consisting of phenolic resins and pitches and (b) graphite powder, and the thus-bonded fibers are fed successively to a carbonizing apparatus or a graphitizing apparatus.

Process for producing pitch-based carbon fibers

In the process for producing pitch carbon fibers by melt-spinning a carbonaceous pitch, and infusiblizing the resulting pitch fibers followed by carbonization and, additionally as needed, graphitization, the pitch fibers are subjected to infusiblization treatment following application of a dimethyl polysiloxane having a viscosity at 25.degree. C. in the range between 0.5 and 500 cSt and removing said dimethyl polysiloxane by washing prior to the carbonization.

Process for producing pitch carbon fibers

Provided is a process for producing pitch carbon fibers by subjecting pitch fibers obtained by melt-spinning a carbonaceous pitch to infusibilization treatment and then to carbonization treatment or both carbonization treatment and subsequent graphitization treatment, characterized in that a dimethyl polysiloxane having a viscosity at 25.degree. C. in the range of 12,000 to 1,000,000 cSt is applied to the fibers after the infusibilization treatment, and the infusibilized fibers with the dimethyl polysiloxane thus applied thereto are then subjected to the carbonization treatment or both the carbonization treatment and the subsequent graphitization treatment.

A precursor pitch for the production of carton fibers is obtained by heat-treating a carbonaceous pitch in the form of a thin film having a thickness not larger than 5 mm at a temperature in the range of 250.degree. to 390.degree. C. and under a reduced pressure not higher than 100 mmHg. By melt-spinning this precursor pitch and subjecting the resultant pitch fiber to infusiblization and carbonization and, if required, to subsequent graphitization, there is obtained a high quality carbon fiber.

Process for preparing precursor pitch for carbon fibers

Provided is a process for producing a pitch-based graphite fiber, which process comprises treating a pitch fiber in an oxidative gas atmosphere to render it infusible, said pitch fiber being obtained by melt-spinning a carbonaceous pitch, then heat-treating the infusibilized fiber at 400.degree.-750.degree. C. in an inert gas atmosphere to obtain a precarbonized fiber substantially containing oxygen, then raising the temperature to 2,000.degree.-3,000.degree. C. at a rate of 500.degree. C. or higher per minute in an inert gas atmosphere and heat-treating the precarbonized fiber at the raised temperature of 2,000.degree.-3,000.degree. C. in said inert gas atmosphere.

Process for producing pitch based graphite fibers

A process for producing carbon fibers, comprising melt spinning a carbonaceous pitch to obtain pitch fibers, contacting the thus obtained pitch fibers with hydrobromic acid, making the thus contacted fibers infusible in an oxidizing atmosphere and then carbonizing and, if desirable, graphitizing the thus treated pitch fibers to obtain the carbon fibers.

Process for producing carbon fibers

A starting pitch for carbon fibers is obtained by mixing (1) 100 parts by volume of a heavy fraction oil boiling at not lower than 200.degree. C. and obtained at the time of fluidized catalytic cracking of petroleum with (2) 10 to 200 parts by volume of a fraction boiling in the range of 250.degree. to 550.degree. C. obtained by distilling under reduced pressure an oil produced at the time of heat treating a starting pitch and then heat treating the resulting mixture at a temperature of from 370.degree. C. to 480.degree. C. under a pressure of from 2 to 50 Kg/cm.sup.2.G thereby to obtain the starting pitch for carbon fibers. The thus obtained starting pitch is heat treated to obtain a precursor pitch which is melt spun, infusibilized, carbonized or graphitized to obtain the carbon fibers.

Starting pitches for carbon fibers

A starting pitch for carbon fibers, obtained by (A) mixing together (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of fluidized catalytic cracking of petroleum, (2) a hydrogenated oil selected from aromatic hydrocarbons of 2-10 rings having their nuclei partly hydrogenated and specific fractions boiling at 160.degree.-650.degree. C. and containing such aromatic hydrocarbons and (3) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum, to form a mixture of the oils (1), (2) and (3), and then (B) heat treating the thus formed oil mixture at 370.degree.-480.degree. C. and 2-50 Kg/cm.sup.2.G thereby to obtain the starting pitch.

A pitch which affords a carbon fiber having a high strength and a high elastic modulus is obtained by treating a pitch containing 5 to 35 weight percent of an optically anisotropic region with sulfur.

Pitch for carbon fibers

A pitch which affords a carbon fiber having a high strength and a high elastic modulus is obtained by treating a pitch containing 5 to 35 wt. % of an optically anisotropic region with an oxidizing gas, followed by hydrogenation treatment if required.

A process for the production of carbon fibers which comprises using a specific optically isotropic pitch having a reflectivity of 9.0-11.0% as the material for the carbon fibers.

Process for the production of pitch-derived carbon fibers

A process for the production of high performance carbon fibers which comprises using as the starting material a specific pitch having the lowest reflectivity in the range of 8.5-9.3% and the highest reflectivity in the range of 11.8-12.5%.

Process for production of pitch-derived carbon fibers

A process for the production of carbon fibers comprising heat treating a starting material, melt spinning the resulting precursor pitch, infusibilizing the pitch fibers and carbonizing or graphitizing the infusibilized pitch fibers, characterized in that the starting pitch is obtained by heat treating coal tar and/or coal liquefaction pitch at a specific temperature and a specific hydrogen pressure or by mixing coal tar and/or coal liquefaction tar with at least one nucleus-hydrogenated hydrocarbon of 2-3 rings in a specific mixing ratio and then heat treating the resulting mixture at a specific temperature and a specific pressure. In one embodiment, this invention relates to the starting pitch and carbon fibers obtained by said process.

A starting pitch for carbon fibers, obtained by mixing (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum with (2) wax and then heat treating the resulting mixture at a specified temperature and pressure thereby to obtain the starting pitch, the thus obtained starting pitch being heat treated to produce a precursor pitch which is melt spun, infusibilized, carbonized or graphitized to obtain the carbon fibers.

A starting pitch for carbon fibers, obtained by (A) mixing (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum with (2) a hydrogenated oil selected from aromatic hydrocarbons of 2-10 rings in which the nuclei have been hydrogenated and specific fractions boiling at 160.degree.-650.degree. C. and containing such nuclei-hydrogenated hydrocarbons and then (B) heat treating the resulting mixed oil at 370.degree.-480.degree. C. and 2-50 Kg/cm.sup.2.G to obtain the starting pitch for carbon fibers.

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Kamakura, Japan

Takao Hirose