JPS5818419A - Raw material pitch for carbon fiber - Google Patents

Abstract

PURPOSE:To obtain the titled pitch, capable of retaining the softening point at a low value and forming a mesophase easily, and having improved properties, by heat-treating a mixture of two specific heavy oils with a nuclear hydrogenated aromatic hydrocarbon under specific conditions. CONSTITUTION:A mixture of (A) a heavy oil, having a boiling point >=200 deg.C, and formed in preparing an olefin by cracking petroleum with ateam as a by- product with (B) a heavy oil, having a boiling point >=200 deg.C, and formed in preparing gasoline by the fluid catalytic cracking of petroleum as a by-product and (C) a nuclear hydrogenated bi- or frinuclear aromatic hydrocarbon, preferably dihydroanthracene, is heat-treated at 370-480 deg.C and 2-50kg/cm<2>.G to give the aimed pitch. Usually, the resultant precursor pitch obtained by heat-treating the pitch is preferably melt spun, made infusible, and carbonized, etc. to afford the carbon fibers. EFFECT:Carbon fibers having improved elasticity and strength are obtained.

Description

【発明の詳細な説明】 本発明は炭素繊維製造用原料としての優れた性能を有す
るピッチに関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pitch having excellent performance as a raw material for producing carbon fibers.

現在、炭素繊維は主にポリアクリロニトリルを原料とし
て製造されている。しかしながらポリアクリロニトリル
を原料とした場合、原料が高価であり、また加熱炭化時
において繊維状の原形がくずれ易く、さらに炭化収率も
悪いという欠点がある。Currently, carbon fiber is mainly manufactured using polyacrylonitrile as a raw material. However, when polyacrylonitrile is used as a raw material, there are disadvantages in that the raw material is expensive, the original fibrous shape is easily destroyed during heating and carbonization, and the carbonization yield is also poor.

近年、こ、の点に着目してピッチを原料として炭素繊維
を製造する方法が数多く報告されている。In recent years, focusing on this point, many methods have been reported for producing carbon fibers using pitch as a raw material.

ピッチを原料として用いた場合、原料が安価で゛あり、
また炭化収率が通常８５〜９５％と高いため、安価に炭
素繊維を製造できることが期待される。When pitch is used as a raw material, the raw material is inexpensive;
Furthermore, since the carbonization yield is usually as high as 85 to 95%, it is expected that carbon fibers can be produced at low cost.

しかしながら、ピッチを原料として得られる炭素繊維は
、ポリアクリロニトリル系炭素繊維に比べ、弾性率は高
いものの、強度が劣るという問題がある。従って、もし
この問題点を解決し、また弾性率をさらに向上し得るこ
とができれば、ピッチから安価に高強度かつ高弾性率の
炭素繊維を製造することが可能となる。However, carbon fiber obtained using pitch as a raw material has a problem in that although it has a higher elastic modulus than polyacrylonitrile carbon fiber, it has inferior strength. Therefore, if this problem can be solved and the elastic modulus can be further improved, it will be possible to inexpensively produce carbon fibers with high strength and high elastic modulus from pitch.

最近になって、市販の石油ピッチを熱処理してメソ相（
ｍｅｓｏｐｂａｓｅ　）と呼ばれる光学的異方性の液晶
を含有するピッチを得、このメソ相を含有するピッチを
前駆体ピッチ（以後、溶融紡糸時におけるピッチを前駆
体ピッチと呼ぶ）として用い、この前駆体ピッチを溶融
紡糸した後、不融化し、次いで炭化あるいは更に黒鉛化
することにより、弾性率および強度が向上した炭素繊維
が得られることが報告された（特開昭４９−１９１２７
号）。Recently, commercially available petroleum pitch has been heat treated to form a mesophase (
A pitch containing an optically anisotropic liquid crystal called mesopbase is obtained, and the pitch containing this mesophase is used as a precursor pitch (hereinafter, the pitch during melt spinning is referred to as precursor pitch), and this precursor is It has been reported that carbon fibers with improved elastic modulus and strength can be obtained by melt-spinning pitch, making it infusible, and then carbonizing or graphitizing it (Japanese Patent Laid-Open No. 49-19127).
issue).

しかしながら、ピッチが液晶を形成し得るか否かは種々
の要因により決まるものであり、また液晶の構造や軟化
点、粘度等の物性は原料ピッチに大きく依存するもので
ある。前記特開昭４９−１９１２７号はメソ相を含有す
るピッチ（以後、メソ相ピッチと略記する）の調製法に
関するものであって、良質のメソ相ピッチを形成するた
めの原料ピッチについては何ら言及していない。前記し
たように、良質のメソ相ピッチは原料ピッチに大きく依
存するものであり、最適な原料ピッチを見出すことがで
きれば弾性率お！゛び強度がさらに優れた炭素繊維を製
造することが可能となる。それ故、この最適の原料ぎッ
チを見出すことが当該技術分野の重要な課題である。However, whether a pitch can form a liquid crystal is determined by various factors, and the structure, softening point, viscosity, and other physical properties of the liquid crystal greatly depend on the raw material pitch. JP-A-49-19127 relates to a method for preparing pitch containing a mesophase (hereinafter abbreviated as mesophase pitch), and does not mention anything about the raw material pitch for forming high quality mesophase pitch. I haven't. As mentioned above, high-quality mesophase pitch is highly dependent on the raw material pitch, and if the optimal raw material pitch can be found, the elastic modulus can be improved! It becomes possible to produce carbon fibers with even better strength and strength. Therefore, finding this optimal raw material ratio is an important challenge in the technical field.

例えば、コールタールピッチはカービンプラック状のキ
ノリンに不溶で不融性の物質を含有しており、これらは
前駆体ピッチの不均一性の原因となり紡糸性を悪くさせ
るばかりか、炭素繊維の強度および弾性率に悪影響を及
ぼす。For example, coal tar pitch contains substances that are insoluble and infusible in carbine plaque-like quinoline, and these not only cause non-uniformity of the precursor pitch and deteriorate spinnability, but also reduce the strength and strength of carbon fibers. Adversely affects elastic modulus.

一方、市販の石油ピッチやその他の合成ピッチの多くは
、キノリンに不溶で不融性の物質をほとんど含有してい
ないが、これらのピッチを加熱処理して前駆体ピッチを
調製する段階でキノリンに不溶な高分子量成分が生成す
る。すなわち、これらのピッチを熱処理すると熱分解と
重縮合反応が併発し、低分子量成分は徐々に高分子量化
し、キノリンに不溶の高分子量成分となり、また同時に
高分子量成分はさらに高分子量化する。これに伴ってピ
ッチの軟化点も上昇する。このキノリンネ溶分カコール
タール中のカーボンブラック状物質に類似の物質であれ
ば、前述の如く紡糸以降の工程で悪影響を及ぼす。また
、前記のカーボンブラック状物質とは異なる物質であっ
たとしても、多　　　”葉のキノリンネ溶分の存在と高
い軟化点は溶融紡糸の段階で悪影響を及ぼす。すなわち
、前駆体ピッチを溶融紡糸するためには、前駆体ピッチ
が紡糸可能な粘度になるまで紡糸温度を上げることが必
要であって、前駆体ピッチの軟化点が余りにも高過ぎれ
ば、紡糸温度も当然高くせざるを得す、その結果、キノ
リンネ溶分は一層高分子量化すると共に、ピッチの熱分
解が起こり軽質ガスが発生し、均一な前駆体ピッチとは
な９得ず、紡糸することが事実上不可能となる。On the other hand, many commercially available petroleum pitches and other synthetic pitches contain almost no insoluble and infusible substances in quinoline, but during the heat treatment of these pitches to prepare precursor pitch, quinoline is Insoluble high molecular weight components are produced. That is, when these pitches are heat-treated, thermal decomposition and polycondensation reactions occur simultaneously, and the low molecular weight components gradually increase in molecular weight to become high molecular weight components that are insoluble in quinoline, and at the same time, the high molecular weight components further increase in molecular weight. Along with this, the softening point of the pitch also increases. If the substance is similar to the carbon black-like substance in the quinoline-soluble cacol tar, it will have an adverse effect on the steps after spinning as described above. In addition, even if the material is different from the carbon black-like material mentioned above, the presence of multi-leaf quinoline dissolved components and a high softening point have a negative effect on the melt-spinning stage. In order to achieve this, it is necessary to raise the spinning temperature until the precursor pitch has a viscosity that allows spinning, and if the softening point of the precursor pitch is too high, the spinning temperature must also be raised. As a result, the molecular weight of the quinoline solution becomes higher, and the pitch is thermally decomposed to generate light gas, resulting in a uniform precursor pitch, making spinning virtually impossible.

このように前駆体ピッチは、比較的低い軟化点と紡糸す
るために適当な粘度を持っていなければならない。また
、紡糸時さらには炭化時に揮発性成分を実質的に含有す
るものであってはならない。The precursor pitch must thus have a relatively low softening point and a suitable viscosity for spinning. Furthermore, it must not substantially contain volatile components during spinning or carbonization.

このため、生成したキノリンネ溶分を加圧ｐ過や溶剤分
別等の手段により除去することにより炭素繊維製造用前
駆体ピッチを調製することが行われている（特開昭４７
−９８０４号、同５０−１４２８２０号、同５５−１３
４２号、同５５−５９５４号）。しかしながら、これら
の手段を用いた場合には処理装置の複雑化および処理費
用の増大を招き、経済的観点から好ましいものではない
。For this reason, precursor pitch for producing carbon fibers is prepared by removing the generated quinoline-solubilized content by pressure filtration, solvent fractionation, etc.
-9804, 50-142820, 55-13
No. 42, No. 55-5954). However, when these means are used, the processing equipment becomes complicated and the processing cost increases, which is not preferable from an economic point of view.

もし、原料ピッチとして優れた性能を有するピッチを用
いることにより、メソ相化の加熱段階でキノリンネ溶分
となる高分子量成分を生成させないことができれば最も
好ましいものである。It is most preferable if pitch having excellent performance is used as the raw material pitch so that high molecular weight components which become quinoline-soluble components can be prevented from being produced in the heating step of mesophase formation.

本発明者らは、これらの課題について鋭意研究した結果
、本発明を完成したものである。すなわち、本発明者ら
は、前駆体ピッチを調製する段階で高分子量成分の生成
を抑制し、最適な粘度を有し、また炭化初期の段階では
芳香族平面が秩序だって配列をし易い組成を持つことが
できる性能の優れた原料ピッチを見出したものである。The present inventors have completed the present invention as a result of intensive research into these problems. That is, the present inventors suppressed the formation of high molecular weight components at the stage of preparing the precursor pitch, had an optimal viscosity, and created a composition in which the aromatic planes were easily arranged in an orderly manner at the early stage of carbonization. We have discovered a raw material pitch with excellent performance.

換言すれば、本発明は軟化点が比較的低く保持され、か
つメソ相を容易に形成するような原料ピッチを提供する
ものである。In other words, the present invention provides a raw material pitch whose softening point is kept relatively low and which readily forms a mesophase.

以下に本発明を詳述する。The present invention will be explained in detail below.

本発明は、原料ピッチを加熱処理して得られる前駆体ぎ
ッチを溶融紡糸した後、不融化処理および炭化あるいは
更に黒鉛化処理して炭素繊維を製造するに当たり、該原
料ピッチが（１）石油類を水蒸気分解した際に得られる
沸点２００℃以上の重質油と（２）石油類を流動接触分
解した際に得られる沸点２００℃以上の重質油と（３）
２環もしくは３環の芳香族系炭化水素の核水素化物との
混合物を温度３８０〜４８０℃、圧力２〜５０　’ｒｑ
ｌｄ　・Ｇにて熱処理して得られるものであ乏ことを特
徴とする炭素繊維用原料ピッチに関する。The present invention provides a method for manufacturing carbon fibers by melt-spinning a precursor fiber obtained by heat-treating raw material pitch, and then subjecting it to infusible treatment and carbonization or further graphitization treatment. (2) Heavy oil with a boiling point of 200°C or higher obtained when petroleum is subjected to fluid catalytic cracking and (3)
A mixture of a 2- or 3-ring aromatic hydrocarbon with a nuclear hydride is heated at a temperature of 380 to 480°C and a pressure of 2 to 50'rq.
The present invention relates to a raw material pitch for carbon fibers, which is characterized in that it is obtained by heat treatment at ld.G.

本発明の原料ピッチを用いてメソ相化反応を行わせしめ
た場合、キノリンネ溶分の生成が抑制されるばかりか、
ピ°ッチが改質され、最終製品である炭素繊維が高弾性
率で、かつ高強度となり得たこと°は全く予期され得な
いものであった。When the mesophase reaction is carried out using the raw material pitch of the present invention, not only the production of quinoline-soluble components is suppressed, but also
It was totally unexpected that the pitch could be modified and the final product, carbon fiber, could have a high modulus of elasticity and high strength.

これに対し、コールタールピッチ、市販の石油ピッチあ
るいは合成ピッチを特開昭４９−１９１２７号の方法に
従って加熱処理し、メソ相化を行ったところ、生成ピッ
チの軟化点が３４０　’Ｃ以上のもの、固形物が沈積し
たもの、あるいは固形物が沈積しないまでもキノリンネ
溶分が７０％以上にも達したもの等、多くの場合、溶融
紡糸が事実上不可能であった。また溶融紡糸を行い得た
場合でも、さらに不融化、炭化および黒鉛化処理して得
た炭素繊維の強度は１２０〜２００　ｋｇ７ｍｎ２、弾
性率は１２〜２０　ｔｏｎ／ＩＩｌ＋１２程度であった
。また高軟化点のものを紡糸した場合には、紡糸物中に
熱分解ガス発生に起因する空孔が存在していた。On the other hand, when coal tar pitch, commercially available petroleum pitch, or synthetic pitch was heat-treated according to the method of JP-A-49-19127 to convert it into a mesophase, the resulting pitch had a softening point of 340'C or higher. In many cases, melt spinning was practically impossible, such as those in which solid matter was deposited, or even if no solid matter was deposited, the quinoline dissolved content reached 70% or more. Further, even when melt spinning could be performed, the strength of the carbon fiber obtained by further infusibility, carbonization, and graphitization treatment was about 120 to 200 kg7m2, and the elastic modulus was about 12 to 20 ton/IIl+12. Furthermore, when a material with a high softening point was spun, pores were present in the spun material due to the generation of thermal decomposition gas.

本発明において用いられる石油類を水蒸気分解した際に
得られる沸点、２００℃以上の重質油とは、ナフサ、灯
油あるいは軽油等の石油類を通常７００〜１２００℃で
水蒸気分解して、エチレン、プロピレン等のオレフィン
類を製造する際に副生ずる重質油であって、実質的に沸
点が２００〜４５０℃の範囲内の重質油である。The heavy oil with a boiling point of 200°C or higher obtained by steam cracking petroleum used in the present invention means ethylene, It is a heavy oil that is produced as a by-product when producing olefins such as propylene, and has a boiling point substantially within the range of 200 to 450°C.

本発明において用いられる石油類を流動接触分解した際
に得られる沸点２００　℃以上の重質油とは、灯油゛、
軽油あるいは常圧残油等の石油類を天然あるいは合成の
シリカ・アルミナ触媒あるいはぜオライド触媒の存在下
に４５０〜５５０℃、ｔ−圧〜２０　ｋｌ／ｃｒｌ　・
Ｇにて流動接触分解することにより、ガソリン等の軽質
油を製造する際に副生ずる重質油であって、実質的に沸
点が２００〜４５０℃の範囲内の重質油である。The heavy oil with a boiling point of 200°C or higher obtained by fluid catalytic cracking of petroleum used in the present invention refers to kerosene,
Petroleum such as light oil or atmospheric residual oil is heated at 450 to 550°C and t-pressure to 20 kl/crl in the presence of a natural or synthetic silica/alumina catalyst or zeolide catalyst.
It is a heavy oil that is produced as a by-product when producing light oil such as gasoline by fluid catalytic cracking in G, and is a heavy oil that substantially has a boiling point within the range of 200 to 450°C.

本発明において使用する２環もしくは３環の芳香族系炭
化水素の核水素化物とは、ナフタリン、インデン、ビフ
ェニル、アセナフチレン、アンスラセン、フェナンスレ
ンおよびこれらの炭素数１〜３のアルキル置換体の核水
素化物である。具′体的には、デカリン、メチルデカリ
ン、テトラリン、メチルテトラリン、ジメチルテトラリ
ン、エチルテトラリン、インプロピルテトラリン、イン
ダン、デカヒドロビフェニル、アセナフテン、メチルア
セナフテン、テトラヒドロアセナフテン、ジヒドロアン
スラセン、メチルヒドロアンスラセン、ジメチルヒドロ
アンスラセン、エチルヒドロアンスラセン、テトラヒド
ロアンスラセン、ヘキサヒドロアンスラセン、オクタヒ
ドロアンスラセン、ドデカヒドロアンスラセン、テトラ
デカヒドロアンスラセン１．ジヒドロフェナンスレン、
メチルジヒドロフェナンスレン、テトラヒドロフェナン
スレン、ヘキサヒドロフェナンスレン、オクタヒドロフ
ェナンスレン、ドデカヒドロフェナンスレンおよびテト
ラデカヒドロフェナンスレンを挙げることができる。特
に２環また屯肉環の縮合環状芳香族系炭化水素の核水素
化物が好ましい。本発明においては、これらの２種以上
の混合物として用いることもできる。Nuclear hydrides of two- or three-ring aromatic hydrocarbons used in the present invention include naphthalene, indene, biphenyl, acenaphthylene, anthracene, phenanthrene, and alkyl substituted products thereof having 1 to 3 carbon atoms. It is. Specifically, decalin, methyldecalin, tetralin, methyltetralin, dimethyltetralin, ethyltetralin, inpropyltetralin, indane, decahydrobiphenyl, acenaphthene, methylacenaphthene, tetrahydroacenaphthene, dihydroanthracene, methylhydroanthracene. 1. dihydrophenanthrene,
Mention may be made of methyldihydrophenanthrene, tetrahydrophenanthrene, hexahydrophenanthrene, octahydrophenanthrene, dodecahydrophenanthrene and tetradecahydrophenanthrene. In particular, a nuclear hydride of a condensed cyclic aromatic hydrocarbon having two rings or a thick ring is preferable. In the present invention, a mixture of two or more of these can also be used.

本発明の原料ピッチは、（１）石油類を水蒸気分解した
際に得られる沸点２００　’Ｃ以上の重質油と（２）石
油類を流動接触分解した際に得られる沸点２００℃以上
の重質油と（３）２環もしくは３環の芳香族系炭化水素
の核水素化物を特定の割合で混合し、かつ特定の条件下
に加熱処理することにより得られる。The raw material pitch of the present invention consists of (1) heavy oil with a boiling point of 200'C or more obtained when petroleum is steam cracked and (2) heavy oil with a boiling point of 200'C or more obtained when petroleum is subjected to fluid catalytic cracking. It is obtained by mixing quality oil and (3) a nuclear hydride of a two- or three-ring aromatic hydrocarbon in a specific ratio and heat-treating the mixture under specific conditions.

上記の成分（１）と成分（２）の混合割合は、成分（１
）：成分（２）が重量比で１：０．１〜９、好ましくは
１：０．２〜４である。成分（３）の混合割合は、成分
（１）と成分（２）の合計量に対し、重量比で０．１〜
２倍、好ましくは０２〜１．５倍用いる。加熱処理温度
としては３７０〜４８０℃、好ましくは３９０〜４６０
℃の範囲内の温度で行う。加熱処理温度が３７０℃より
も低いと反応の進行が遅く、長時間を要するため不経済
である。また４８０℃よりも高い温度で熱処理を行うと
コーキング等の問題が生じ、好ましくない。加熱処理時
間は、加熱処理温度との兼ね合いで決められるものであ
り、低温の場合は長時間、高温の場合は短時間行う。通
常は、１５分〜２０時間、爵ましくけ３０分〜１０時間
の範囲内の処理時間を採用することができる。圧力に関
しては任意の圧力下で実施し得るが、原料中の有効成分
が未反応の′１ま実質的に系外に留出しない圧力が好ま
しく、具体的には２〜５０　ｋＶｃｒｒｔ”Ｇ。The mixing ratio of component (1) and component (2) above is
): component (2) in a weight ratio of 1:0.1 to 9, preferably 1:0.2 to 4. The mixing ratio of component (3) is 0.1 to 0.1 to the total amount of component (1) and component (2) by weight.
Use twice, preferably 02 to 1.5 times. The heat treatment temperature is 370 to 480°C, preferably 390 to 460°C.
Perform at a temperature within the range of °C. If the heat treatment temperature is lower than 370° C., the reaction progresses slowly and takes a long time, which is uneconomical. Further, heat treatment at a temperature higher than 480° C. causes problems such as caulking, which is not preferable. The heat treatment time is determined in consideration of the heat treatment temperature; when the temperature is low, the heat treatment is performed for a long time, and when the temperature is high, the heat treatment is performed for a short time. Usually, a treatment time within the range of 15 minutes to 20 hours, more preferably 30 minutes to 10 hours, can be employed. Regarding the pressure, it can be carried out under any pressure, but it is preferably at a pressure at which the active ingredients in the raw materials are not substantially distilled out of the system until they are unreacted, specifically from 2 to 50 kVcrrt''G.

好ましくは５〜３０　ｋＮｉ・Ｇが採用される。Preferably, 5 to 30 kNi.G is employed.

熱処理を行った後、必要であれば蒸留等の操作によシ軽
質分を除去することも好ましく採用される。After the heat treatment, it is also preferable to remove light components by distillation or the like, if necessary.

かくして得られる本発明の原料ピッチを用いることによ
り、加熱処理してメソ相化を行った際、キノリンネ溶分
である高分子量成分の生成が抑制されると同時にピッチ
の軟化点の上昇を防ぐことができ、さらに芳香族平面が
秩序だって配列し易い組成を持った良好な前駆体ピッチ
となる。この結果、弾性率および強度がきわめて優れた
炭素繊維を得ることができる。By using the raw material pitch of the present invention obtained in this way, when heat-treated to form a mesophase, the production of a high molecular weight component that is a quinoline-soluble component can be suppressed, and at the same time, an increase in the softening point of the pitch can be prevented. This results in a good precursor pitch having a composition in which the aromatic planes are easily arranged in an orderly manner. As a result, carbon fibers with extremely excellent elastic modulus and strength can be obtained.

本発明の原料ピッチを用いて炭素繊維をＦ造する方法は
公知の方法を採用することができる。すなわち、原料ピ
ッチを加熱処理してメソ相化を行い、得られる前駆体ピ
ッチを溶融紡糸した後、不融化処理および炭化あるいは
さらに黒鉛化処理を行って炭素繊維を製造する。A known method can be used to fabricate carbon fibers using the raw material pitch of the present invention. That is, raw material pitch is heat-treated to form a mesophase, the resulting precursor pitch is melt-spun, and then subjected to infusibility treatment and carbonization or further graphitization treatment to produce carbon fibers.

原料ピッチを加熱処理し、メソ相化を行って前駆体ピッ
チを得る段階での反応は、通常、温度３４０〜４５０℃
、好ましくは３７０〜４２０　”ｃで常圧あるいは減圧
下に窒素等の不活性ガスを通気することによって行われ
る。この時の加熱処理時間は、温度、不活性ガスの通気
量等の条件により任意に行い得るものであるが、通常、
１〜５゜時間、好ましくは３〜２０時間で行う。不活性
がスの通気量は０．７〜５．　Ｏ５ｃｆｈ／ｌｂピツチ
が好ましい。The reaction at the stage of heat-treating the raw pitch and converting it into a mesophase to obtain the precursor pitch is usually carried out at a temperature of 340 to 450°C.
It is preferably carried out at 370 to 420"C by bubbling inert gas such as nitrogen under normal pressure or reduced pressure. The heat treatment time at this time can be determined as desired depending on conditions such as temperature and amount of inert gas aerated. However, usually
This is carried out for 1 to 5 hours, preferably 3 to 20 hours. The aeration rate of inert gas is 0.7 to 5. A pitch of O5cfh/lb is preferred.

前駆体ピッチを溶融紡糸する方法としては、押出法、遠
心法、霧吹法等の公知の方法を用いるこ　　　　１とが
できる。As a method for melt-spinning the precursor pitch, known methods such as an extrusion method, a centrifugation method, and an atomization method can be used.

溶融紡糸されて得られるピッチ繊維は、次に酸化性ガス
雰囲気下で不融化処理が施される。酸化性ガスとしては
、通常、酸素、オゾン、空気、窒素酸化物、ハロゲン、
亜硫酸ガス等の酸化性ガスを１種あるいは２種以上用い
る。この不融化処理は、被処理体である溶融紡糸された
ピッチ繊維が軟化変形しない温度条件下で実施される。The pitch fibers obtained by melt spinning are then subjected to infusibility treatment in an oxidizing gas atmosphere. Oxidizing gases usually include oxygen, ozone, air, nitrogen oxides, halogens,
One or more oxidizing gases such as sulfur dioxide gas are used. This infusibility treatment is carried out under temperature conditions in which the melt-spun pitch fibers, which are the objects to be treated, are not softened or deformed.

例えば２０〜３６０℃、好ましくは２０〜３００℃の温
度が採用される。また処理時間は通常、５分〜１０時間
である。For example, a temperature of 20 to 360°C, preferably 20 to 300°C is employed. Moreover, the processing time is usually 5 minutes to 10 hours.

不融化処理されたピッチ繊維は、次に不活性ガス雰囲気
下で炭化あるいは更に黒鉛化を行い、炭素繊維を得る。The infusible pitch fibers are then carbonized or further graphitized in an inert gas atmosphere to obtain carbon fibers.

炭化は通常、温度ＳＯＯ〜２５００℃で行う。一般には
炭化に要する処理時間は０．５分〜１０時間である。さ
らに黒鉛化を行う場合には、温度２５００〜３５００°
Ｃで通常１秒〜１時間行う。Carbonization is usually carried out at a temperature of SOO to 2500°C. Generally, the treatment time required for carbonization is 0.5 minutes to 10 hours. When further graphitizing, the temperature is 2500 to 3500°.
It is usually carried out at C for 1 second to 1 hour.

また、不融化、炭化あるいは黒鉛化処理の際、必要であ
れば収縮や変形等を防止する目的で、被処理体に若干の
荷重あるいは張力をかけておくこともできる。Furthermore, during the infusibility, carbonization, or graphitization treatment, a slight load or tension may be applied to the object to be treated, if necessary, in order to prevent shrinkage, deformation, etc.

以下に実施例をあげ本発明を具体的に説明するが、一本
発明はこれらに制限されるものではない。The present invention will be specifically explained below with reference to Examples, but the present invention is not limited thereto.

実施例１　。Example 1.

ナフサを８３０℃で水蒸気分解した際に副生じた沸点２
００℃以上の重質油（以下、重質油（１）と略す。その
性状を第１表に示す）１００重量部と、アラビア系原油
の減圧軽油（ＶＧＯ）の水素化処理油をシリカ・アルミ
ナ系触媒を用いて５００℃にて接触分解して得られた沸
点２００℃以上の重質油（以下、重質油（２）と略す。Boiling point 2 produced by-product when naphtha is steam cracked at 830℃
100 parts by weight of heavy oil (hereinafter referred to as heavy oil (1) whose properties are shown in Table 1) with a temperature of 00°C or higher and hydrogenated oil of vacuum gas oil (VGO) of Arabian crude oil were mixed with silica. Heavy oil with a boiling point of 200°C or higher obtained by catalytic cracking at 500°C using an alumina catalyst (hereinafter abbreviated as heavy oil (2)).

その性状を第２表に示す）５０重量部と、テトラリン５
０重量部とを混合し、圧力２０　ｋｌ？／ｉ　ｊ　Ｇ　
、温度４３０″Ｃにて３時間熱処理した。この熱処理油
を２５０°Ｃ／１０ヨ）（ｇで蒸留して軽質弁を留出さ
せ、軟化点６２℃、ベンゼン不溶分０．８チの原料ピッ
チを得た。Its properties are shown in Table 2) 50 parts by weight, and tetralin 5
0 parts by weight and a pressure of 20 kl? /i j G
The oil was heat-treated at 430"C for 3 hours. The heat-treated oil was distilled at 250°C/10g to remove light valves, and the raw material had a softening point of 62°C and a benzene insoluble content of 0.8g. Got the pitch.

次に、この原料ピッチ３０．９に対し、窒素を６００　
ｍｌ１分で通気しながら攪拌し、温度４００℃で１０時
間熱処理を行い、軟化点２８１℃、キノリンネ溶分２６
重量％、メソ相含量７５％のビッチを得た。このピッチ
をノズル径０．３蛎φ、Ｌ／Ｄ＝２の紡糸器を用い３３
８℃にて溶融紡糸を行い、１２〜１７μのピッチ繊維を
つくり、さらに下記に示す条件にて不融化、炭化および
黒鉛化処理して炭素繊維を得た。Next, to this raw material pitch of 30.9, nitrogen was added to 600
Stir with ventilation for 1 minute and heat treat at 400°C for 10 hours to obtain a softening point of 281°C and a quinoline solubility of 26.
A bitch with a mesophase content of 75% by weight was obtained. This pitch is 33 mm using a spinner with a nozzle diameter of 0.3 mm and L/D = 2.
Melt spinning was performed at 8° C. to produce pitch fibers of 12 to 17 μm, and carbon fibers were obtained by infusibility, carbonization, and graphitization treatment under the conditions shown below.

不融化、炭化および黒鉛化の処理条件は以下の如くであ
る。The processing conditions for infusibility, carbonization and graphitization are as follows.

Ｏ不融化条件：空気雰囲気中で、２００℃までは３℃／
分、３００°Ｃまでは１℃／分 の昇温速度で加熱し、３００℃で １５分間保持。O infusibility conditions: In air atmosphere, 3℃/up to 200℃
Heating at a temperature increase rate of 1°C/min up to 300°C, and held at 300°C for 15 minutes.

Ｏ炭化条件：窒素雰囲気中で、５℃／分で昇温し１００
０℃で３０分間保持。O carbonization conditions: In a nitrogen atmosphere, the temperature was raised at a rate of 5°C/min to 100°C.
Hold at 0°C for 30 minutes.

Ｏ黒鉛化条件：アルゴン気流中で、２５℃／分の昇温速
度で、２５００°Ｃまで加熱処理。O graphitization conditions: Heat treatment up to 2500°C at a heating rate of 25°C/min in an argon stream.

得られた炭素繊維の引張強度は２８５　ｋｇ／ｌｔｍ？
、ヤング率は４５　ｔｏｎ／ｍ１２であった。The tensile strength of the obtained carbon fiber is 285 kg/ltm?
, Young's modulus was 45 ton/m12.

第１表　　重質油（１）の性状 第２表　　重質油（２）の性状 比較例１ 実施例１で用いた重質油（１）　１００重量部と重質油
（２）　５０重量部との混合物を圧力１５　ｋｇ／ｃｒ
ｌ　、Ｇ　％温度４００℃にて３時間熱処理した。この
熱処理油を２５０℃／　１．　Ｏｍ＋Ｈｇにて蒸留し、
軽質分を留去させ、軟化点４９℃の原料ピッチを得た０
次に、実施例１と同様の方法でこの原料ピッチを熱処理
して、軟化点３０８℃、キノリンネ溶分４８重量％、メ
ソ相含量８６チのピッチを得た。Table 1 Properties of heavy oil (1) Table 2 Comparative example 1 of properties of heavy oil (2) 100 parts by weight of heavy oil (1) used in Example 1 and 50 parts by weight of heavy oil (2) A mixture of
Heat treatment was performed at a temperature of 400° C. for 3 hours. This heat treated oil was heated at 250℃/1. Distilled at Om+Hg,
Light components were distilled off to obtain raw material pitch with a softening point of 49°C.
Next, this raw pitch was heat-treated in the same manner as in Example 1 to obtain a pitch having a softening point of 308° C., a quinoline soluble content of 48% by weight, and a mesophase content of 86%.

このピッチを実施例１で用いた紡糸器により、３５８℃
で溶融紡糸し、２０〜２７μのピッチ繊維をつくり、実
施例１と同様な方法で不融化、炭化および黒鉛化処理し
て炭素繊維を得た。この炭素繊維の引張強度は１５４　
ｋｇ／ｌｒｄ’　、ヤング率は２７　ｔｏｎ／−であっ
た。This pitch was spun at 358°C using the spinning machine used in Example 1.
The fibers were melt-spun to produce pitch fibers of 20 to 27 μm, and treated in the same manner as in Example 1 to be infusible, carbonized, and graphitized to obtain carbon fibers. The tensile strength of this carbon fiber is 154
kg/lrd' and Young's modulus was 27 ton/-.

比較例２ 実施例１において使用した本発明の原料ピンチの代わり
に、市販の石油ピッチであるアッシーランド（Ａｓｈ　
１ａｎｄ）　２４０ＬＳ　（軟化点１２０℃）を用いて
、実施例１と同様な方法で熱処理を行つたところ、メソ
相含量５０％のピッチを得た。このピッチを実施例１と
同様の方法で溶融紡糸、不融化処理、炭化および黒鉛化
処理して炭素繊維を得た。Comparative Example 2 Instead of the raw material pinch of the present invention used in Example 1, Ashland (Ashland), a commercially available petroleum pitch, was used.
1and) 240LS (softening point: 120° C.) and heat-treated in the same manner as in Example 1, a pitch with a mesophase content of 50% was obtained. This pitch was subjected to melt spinning, infusibility treatment, carbonization and graphitization treatment in the same manner as in Example 1 to obtain carbon fibers.

得られた炭素繊維の引張強度は１３７　ｋｇ□２、ヤン
グ率は２８　ｔｏｎ／１１ＩＩＩ＋２であった。The obtained carbon fiber had a tensile strength of 137 kg□2 and a Young's modulus of 28 ton/11III+2.

実施例２ 実施例１で使用した重質油（１）　１００重量部と重質
油（２）５０重量部とジヒドロアンスラセン４０重量部
とを混合し、圧力１５　ｋｇ／ｃｒｒｉ！−Ｇ　、温度
４３０℃にて２時間熱処理を行った。この熱処理油を減
圧蒸留して軽質分を留去させ、軟化点６３℃の原料ぎッ
チを得た。Example 2 100 parts by weight of the heavy oil (1) used in Example 1, 50 parts by weight of the heavy oil (2) and 40 parts by weight of dihydroanthracene were mixed, and the pressure was 15 kg/crri! -G, heat treatment was performed at a temperature of 430°C for 2 hours. This heat-treated oil was distilled under reduced pressure to remove light components to obtain a raw material with a softening point of 63°C.

次に、この原料ピッチを実施例１と同様の方法で熱処理
を行い、軟化点２６９℃、キノリンネ溶分２３重量％、
メソ相含量７２％のピッチを得た。Next, this raw material pitch was heat-treated in the same manner as in Example 1, with a softening point of 269°C and a quinoline soluble content of 23% by weight.
A pitch with a mesophase content of 72% was obtained.

このピッチを実施例１で用いた紡糸器により３１７℃で
溶融紡糸し、９〜１３μのピッチ繊維をつくり、実施例
１と同様の方法で不融化、炭化、黒鉛化処理して炭素繊
維を得た。この炭素繊維の引張強度は２８７　ｋｇ／１
ａｎ２、ヤング率は５１　ｔｏｎ／１−であった０ 比較例３ 実施例２において、重質油（１）と重質油（２）とジヒ
ドロアンスラセンとの混合物を３６０　℃で熱処理する
ことを除いては実施例１と同様の方法で炭素繊維を得た
。この炭素繊維の引張強度は２１０ｋｆ／ｍｇ２、ヤン
グ率は３０　ｔｏｎ／−であった。This pitch was melt-spun at 317°C using the same spinning machine used in Example 1 to produce pitch fibers of 9 to 13 μm, and treated to be infusible, carbonized, and graphitized in the same manner as in Example 1 to obtain carbon fibers. Ta. The tensile strength of this carbon fiber is 287 kg/1
an2, Young's modulus was 51 ton/1-0 Comparative Example 3 In Example 2, the mixture of heavy oil (1), heavy oil (2), and dihydroanthracene was heat-treated at 360 °C. Carbon fibers were obtained in the same manner as in Example 1 except for the following. This carbon fiber had a tensile strength of 210 kf/mg2 and a Young's modulus of 30 ton/-.

比較例４ 実施例２において、重質油（１）、重質油（２）および
ジヒドロアンスラセンの混合物を５００℃で０５時間熱
処理したところ、反応器内に炭素質物質が沈積し、均一
な原料ピッチを得ることができなかった０ 特許出願人　　日本石油株式会社 代理人　弁理士　伊　東　辰　雄 〃　〃　伊東哲也 手続補正書 昭和５７年１月】９目 特許庁長官　　島　１）春　樹　　殿 １、　事件の表示 昭和５６年特許ｐｐ第１１６３３１号 ２、発明の名称　　　炭素線維用原料ピッチろ、補正を
する者 事件との関係　　　特許出願人 居　所　　東京都港区西新橋−丁目３番１２号名称　（
４４４）日本石油株式会社 代表者　建内保興 ４、代理人　〒１０５ 住　所　　東京都港区虎ノ門二丁目８番１号“′史７．
ニン′ ６、補正の対象 明細書中、［特許請求の範囲の欄」および［発明の詳細
な説明の欄」 ｌ　補正の内容 （１１明細書第７頁第４行の”　３８０〜ｂを１３７０
〜４８０℃」に訂正する。Comparative Example 4 In Example 2, when the mixture of heavy oil (1), heavy oil (2) and dihydroanthracene was heat treated at 500°C for 05 hours, carbonaceous substances were deposited in the reactor and a uniform Unable to obtain raw material pitch 0 Patent applicant: Nippon Oil Co., Ltd. Agent, Patent attorney: Tatsuo Ito 〃 Tetsuya Ito procedural amendment January 1980] 9th Patent Office Commissioner Shima 1) Tono Haruki 1 , Indication of the case Patent No. 116331 No. 116331 of 1982, Title of the invention Pitch filter of raw material for carbon fiber, Person making the amendment Relationship to the case Patent applicant's residence 3-12 Nishi-Shinbashi-chome, Minato-ku, Tokyo Name (
444) Nippon Oil Co., Ltd. Representative: Yasuko Kenuchi 4, Agent: 105 Address: 2-8-1 Toranomon, Minato-ku, Tokyo 7.
6. In the specification subject to amendment, [Claims column] and [Detailed description of the invention column] l Contents of the amendment (11 Specification, page 7, line 4, ``380-b'' to 1370
〜480℃''.

（２、特許請求の範囲を別紙の通り訂正する。(2. The scope of claims is amended as shown in the attached sheet.

別　　　紙 特許請求の範囲Attachment Scope of claims

Claims (1)

【特許請求の範囲】[Claims] 原料ピッチを加熱処理して得られる前駆体ピッチを溶融
紡糸した後、不融化処理および炭化あるｂは更に黒鉛化
処理して炭素繊維を製造するに当たり、該原料ピッチが
（１）石油類を水蒸気分解した際に得られる沸点２００
　”Ｃ以上の重質油と（２）石油類を流動接触分解した
際に得られる沸点２００℃以上の重質油と（３）２環も
しくは３環の芳香族系炭化水素の核水素化物との混合物
を温度３８０〜４８０℃、圧力２〜５０　ｋｔｉ／ｄ　
・Ｇにて熱処理して得られるものであることを特徴とす
る炭素繊維用原料ピッチ。After the precursor pitch obtained by heating the raw material pitch is melt-spun, it is subjected to infusibility treatment and carbonization treatment.b) In order to produce carbon fiber by further graphitization treatment, the raw material pitch is (1) petroleum-based with steam. The boiling point obtained when decomposed is 200
(2) Heavy oil with a boiling point of 200°C or higher obtained by fluid catalytic cracking of petroleum, and (3) Nuclear hydrides of 2- or 3-ring aromatic hydrocarbons. A mixture of
- A raw material pitch for carbon fibers, which is obtained by heat treatment in G.