Toa Nenryo Kogyo Kabushiki Kaisha

Toa Nenryo Kogyo, K. K.

Takayuki Izumi

Tsutomu Naito

Tomio Nomura

Masuo Shinya

Tomoo Nakamura

Kikuji Komine

Kiyoshi Takazawa

Yoshio Uenoyama

Hisao Tanaka

Seikoh Igarashi

Wataru Kobayashi

Seiko Igarashi

A process for manufacturing a carbon fiber or graphite fiber includes melt-spinning a carbonaceous pitch, infusibilizing the resulting pitch fiber, carbonizing, and when necessary graphitizing the fiber. A precursor of the carbonaceous pitch is centrifuged in a molten state to separate the precursor pitch simultaneously into a solids slurry layer, an optically isotropic phase, and an optically anisotropic phase, and the latter is utilized as the carbonaceous pitch.

Process for manufacturing carbon fiber and graphite fiber

In a melt spinning operation, a heated wash gas such as nitrogen or nitrogen and air is blown across the melt spinning nozzles to remove volatiles thereby preventing wetting of the nozzle discharge. The wash gas is maintained at a temperature substantially equal to the melt spinning temperature. The preferred melt spinning material is petroleum pitch.

Method and apparatus for melt spinning

In a process for producing an optically anisotropic carbonaceous pitch having a low softening point for the production of carbon material starting oil to be used is a tar-like substance which is a mixture of compounds not substantially containing chloroform insolubles but containing components having a boiling point of 540.degree. C. or more as principal components and consisting principally of carbon and hydrogen. The tar-like substance has a content of n-heptane insolubles of up to 1 wt % and contains an aromatic oil fraction and a resin fraction as the principal components of n-heptane soluble components. The aromatic carbon fraction, fa, is at least 0.7, the number-average molecular weight is up to 1,000 and the maximum molecular weight is up to 2,000 for each of the aromatic oil and resin fractions.

Optically anisotropic carbonaceous pitch

In a process for producing an optically anisotropic carbonaceous pitch having a low softening point for the production of carbon material a starting oil to be used is a tar-like substance which is a mixture of compounds not substantially containing chloroform insolubles but containing components having a boiling point of 540.degree. C. or more as principal components and consisting principally of carbon and hydrogen. The tar-like substance has a content of n-heptane insolubles of up to 1 wt % and contains an aromatic oil fraction and a resin fraction as the principal components of n-heptane soluble components. The aromatic carbon fraction, fa, is at least 0.7, the number-average molecular weight is up to 1,000 and the maximum molecular weight is up to 2,000 for each of the aromatic oil and resin fractions.

Process for producing optically anisotropic carbonaceous pitch

This invention describes a substantially homogeneous, optically anisotropic carbonaceous pitch characterized in that the major portion of said pitch consists of a continuous, optically anisotropic phase, said optically anisotropic phase contains spherules of an optically isotropic phase having diameters of not more than about 100 .mu.m and dispersed in said optically anisotropic phase, the content of said optically isotropic spherules is up to about 20% on the basis of said pitch as a whole, said pitch contains at least about 30 wt % (based on said pitch) of a quinoline-soluble component, and said pitch has a lower softening point.

Optically anisotropic carbonaceous pitch and process for producing the

A composition for an optically anisotropic carbonaceous pitch suitable for the production of a carbon material having a high tensile strength and a high modulus of elasticity. The composition comprises about 2 to 20 percent by weight of a first, n-heptane-soluble component, about 15 to 45 percent by weight of an n-heptane-insoluble and benzene-soluble, second component and the balance of the composition including benzene-insoluble components. The composition has a volume ratio of an optically anisotropic phase of at least about 90% and a softening point of up to about 320.degree. C.

Optically antisotropic carbonaceous pitch

A substantially uniform mesophase pitch is prepared by treating a mesophase forming pitch material at elevated temperatures above about 380.degree. C. to produce a mixture of mesophase and non-mesophase pitch containing about 20% to about 80% mesophase. The mixture is then maintained at a temperature below about 400.degree. C. for a time sufficient to allow the mesophase to coalesce and settle as a lower separable layer. A mesophase pitch so produced may contain from 90 to 100% mesophase with a softening point of less than 320.degree. C.

Process for producing mesophase pitch

A continuous process for producing an optically anisotropic pitch. A reaction tank is used to treat a starting material. An upper section is utilized for thermal decomposition polycondensation zone. A lower portion of the tank is used as a settling zone.

Process for continuous production of optically anisotropic pitch

A process for producing optically anisotropic pitch containing 80% or more of an anisotropic phase. A starting material is pyrolytically polycondensed. Afterward, the material is maintained at a temperature of between 350.degree. and 400.degree. C. to precipitate a portion of the material rich in the anisotropic phase having a high specific gravity. This portion is separated and further heat treated.

Process for producing a homogeneous low softening point, optically

A homogeneous, optically anisotropic pitch used for the production of carbon materials is prepared from a starting oil comprising a substantially chloroform-insoluble matter-free oily or tarry substance. The starting oil is subjected to thermal cracking and polycondensation to form approximately 20-80% of optically anisotropic phase pitch.

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Iruma, Japan

Takayuki Izumi