# US 4,397,830 A · Starting pitches for carbon fibers

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- Number: US 4,397,830 A
- Document ID: US4397830A
- Status: Granted
- Kind: A
- Application number: 06/366,917
- Filed: 1982-04-09
- Granted: 1983-08-09
- Earliest claimed: 1981-04-13
- Assignees: Nippon Oil Co., Ltd.
- Inventors: Seiichi Uemura; Shunichi Yamamoto; Takao Hirose; Hiroaki Takashima; Osami Kato
- Web page: https://patentgrep.com/patent/US4397830A

## CPC

- D01F 9/155: from petroleum pitch
- C10C 3/00: Working-up pitch, asphalt, bitumen {(compositions of asphalts and other bitumenous materials C08L95/00)}
- D01F 9/322: {for manufacturing filaments from pitch}
- D01F: CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES OR RIBBONS; APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBON FILAMENTS
- C10C: WORKING-UP PITCH, ASPHALT, BITUMEN, TAR; PYROLIGNEOUS ACID (compositions of bituminous materials C08L95/00; carbon filaments by decomposition of organic filaments D01F9/14)

## Abstract

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.

## Claims

### Claim 1

A process for the production of carbon fibers which comprises heat treating a starting pitch to obtain a precursor pitch, melt spinning the thus obtained precursor pitch, infusibilizing the thus spun pitch, carbonizing the thus infusibilized pitch, and if desired, graphitizing the thus carbonated pitch, wherein the starting pitch is produced by the following method:
(A) mixing 100 parts by volume of (1) a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking of petroleum with 10-200 parts by volume of (2) a hydrogenated oil selected from the group consisting of:
(a) aromatic nucleus hydrogenated hydrocarbons prepared from aromatic hydrocarbons of 2-10 rings by hydrogenating the aromatic nucleus thereof;
(b) a hydrogenated oil obtained by contacting a fraction oil boiling at 160.degree.-650.degree. C. produced at the time of heat treating, at 370.degree.-480.degree. C., a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of steam cracking a fraction and/or petroleum boiling at 160.degree.-650.degree. C. obtained at the time of steam cracking petroleum, with hydrogen in the presence of a hydrogenating catalyst to hydrogenate 10-70% of the aromatic nucleus of aromatic hydrocarbons contained in said fraction boiling at 160.degree.-650.degree. C.; and
(c) a hydrogenated oil obtained by contacting a fraction boiling at 160.degree.-650.degree. C. produced at the time of preparing the starting pitches by heat treatment,
with hydrogen in the presence of a hydrogenating catalyst to hydrogenate 10-70% of the aromatic nuclei of aromatic hydrocarbons contained in said fraction boiling at 160.degree.-650.degree. C., to form a mixture of the oils (1) and (2), and then
(B) heat treating the thus formed oil mixture at 370.degree.-480.degree. C. under a pressure of 2-50 kg/cm.sup.2.G thereby to obtain the starting pitch.

### Claim 2 (depends on 1)

A process for the production of carbon fibers according to claim 1, wherein the hydrogenated oil (2)(c) is a hydrogenated oil prepared by collecting a fraction boiling at 160.degree.-650.degree. C. at the time of fluidized catalytic cracking of petroleum and hydrogenating the thus collected fraction to effect 10-70% nuclear hydrogenation therein, a hydrogenated oil prepared by collecting a fraction boiling at 160.degree.-650.degree. C. at the time of heat treating a heavy fraction oil (1) at 370.degree.-480.degree. C. and hydrogenating the thus collected fraction to effect 10-70% nuclear hydrogenation therein, or a hydrogenated oil prepared by collecting a fraction boiling at 160.degree.-650.degree. C. produced at the time of heat treating a heavy fraction oil boiling at not lower than 200.degree. C. obtained at the time of fluidized catalytic cracking of petroleum and hydrogenating the thus collected fraction to effect 10-70% nuclear hydrogenation therein.