JPH048477B2 - - Google Patents

Description

【発明の詳細な説明】 ［産業上の利用分野］ 本発明は、炭素繊維原料ピツチの製造法に関す
る。さらに詳しくは、紡糸性が良好でありそして
機械的性質に優れた炭素繊維を与える炭素繊維原
料ピツチの製造法に関する。 ［従来の技術］ 従来、各種ピツチを原料として炭素繊維を製造
する方法が知られている。ピツチ類を原料とし
て、HP品の炭素繊維を製造するためには、紡糸
用ピツチは光学的に異方性な性質、すなわちメソ
フエース炭素質であることが必要であり、このこ
とはすでに公知である。 しかしながら、ピツチ類に前処理を行なうこと
なく熱処理によつてメソフエースピツチを調製し
ても、紡糸性の良好なピツチとすることはできな
い。そのため前処理法としていくつかの方法が提
案されており、その代表的な方法は水素化処理法
である。 特公昭57−179286号公報には、原料ピツチとし
て、(1)石油類を流動接触分解したさいに得られる
沸点200℃以上の重質油100容量部と、(2)ピツチか
らの沸点160〜400℃の範囲の留分の水素化油10〜
200容量部、との混合物を用い、これを380〜480
℃の温度で、２〜50Kg／cm²・Ｇの圧力下で熱処理
することによる炭素繊維原料ピツチの製造法が開
示されている。 また特開昭57−168989号公報には、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
質油を20Kg／cm²Ｇ以上の水素圧下で、温度400〜
500℃で熱処理することによる炭素繊維原料ピツ
チの製造法が記載されている。 また特開昭58−18421号公報には、光学的に等
方性のプリメソフエース炭素質又は光学的に等方
性のプリメソフエース炭素質を主体とするピツチ
状物質を、実質的にメソフエース炭素質類が増加
しない条件下で紡糸し、次いで不融化処理したの
ち、炭化処理して、プリメソフエース炭素質の実
質的に全部を光学的に異方性のメソフエース炭素
質に変換させることによる炭素繊維の製造法が記
載されている。この方法で用いられる光学的に等
方性のプリメソフエース炭素質はピツチを高価な
テトラヒドロキノリンで処理するか、触媒の存在
下キノリンと水素で処理するかあるいは芳香族炭
化水素と水素で処理することによつて製造される
ことが同公報に記載されている。しかしながら、
テトラヒドロキノリンは非常に高価なため工業的
に使用するには難点がある。 また、特開昭59−196390号公報にはコールター
ル、コールタールピツチを芳香族系油および接触
分解触媒の存在下あるいは非存在下、自生圧下、
350〜500℃で10〜60分間処理し、ついで固形不溶
分を除去した後、常圧下または減圧下で430℃以
上の温度で60分以内処理することによる炭素繊維
原料ピツチの製造法が記載されている。同公報に
は、上記石炭系ピツチに代えて、石油系ピツチで
あるナフサタールを原料とする場合には、紡糸性
に優れたピツチを得ることができないと記載され
ている。 これらの方法にみられるように原料ピツチをあ
らかじめ水素化処理に付すことは紡糸容易なピツ
チを製造するために、極めて有効な方法である。
しかしながら、水素化処理を行うことは製造コス
トの上昇をもたらす。 ［発明が解決すべき問題］ 本発明の目的は、炭素繊維原料ピツチの新規な
製造法を提供することにある。 本発明の他の目的は、流動接触分解残渣油から
良好な紡糸性を示す炭素繊維原料ピツチの新規な
製造法を提供することにある。 本発明のさらに他の目的は、機械的性能の優れ
た炭素繊維を与える炭素繊維原料ピツチの新規な
製造法を提供することにある。 本発明のさらに他の目的は、簡単な操作で上記
の如き優れた性質を備えた炭素繊維原料ピツチを
製造しうる新規な製造法を提供することにある。 ［問題点を解決するための手段および作用］ 本発明によれば、本発明のかかる目的および利
点は、(1)石油類の流動接触分解により得られる重
質油、その重質油を蒸留して得た留出成分又は残
渣油およびそれらを熱処理して得られたピツチよ
り成る群から選ばれる少なくとも１種の成分であ
つて、炭素原子対水素原子の原子比（Ｃ／Ｈ）が
0.7〜1.4の範囲にありしかも芳香族炭素分率（fa）
が0.4〜0.9の範囲にある原料を、自生圧下、350
〜550℃の範囲で加熱処理し、 (2)上記工程(1)で得られた反応混合物から固形物及
び原料に含まれる触媒粉末を分離除去して第１の
処理混合物を得、 (3)上記工程(2)で得られた第１の処理混合物を250
〜400℃の範囲の温度に加熱して同温度下で留出
する軽質留分を除去して第２の処理混合物を得、
そして (4)上記工程(3)で得られた第２の処理混合物を400
〜550℃の範囲の温度でさらに処理して光学的異
方性度が65〜95％であるピツチを生成する、 ことを特徴とする炭素繊維原料ピツチの製造法に
よつて達成される。 本発明の上記第１工程（上記工程(1)）では、本
発明の出発原料として、石油類の流動接触分解に
より得られる重質油を蒸留して得た留出成分又は
残渣油あるいはそれらを熱処理して得たピツチの
少なくともいずれか一つが用いられる。 原料として用いられるこれらの成分は、炭素原
子対水素原子の原子比（Ｃ／Ｈ）が0.7〜1.4、好
ましくは0.8〜1.3の範囲にある。これらの原子比
は、各成分について行つた元素分析の結果から算
出される。 また、原料として用いられるこれらの成分は、
芳香族炭素分率（fa）が0.4〜0.9、好ましくは0.5
〜0.8の範囲にある。 芳香族炭素分率（fa）は、原料0.05ｇを重クロ
ロホルム１ｇに溶解させた溶液に、内部標準とし
てテトラメチルシランを加えて¹H−NMRを測定
した結果から、常法のBrown−Landner法に基づ
き下式により算出される。 fa＝Ｃ／Ｈ−（Hα＋Hβ）／2H／Hγ／3H／Ｃ／Ｈ fa；芳香族炭素分率 Ha；芳香族水素（６〜10ppm） Hα；α炭素についた脂肪族水素（２〜
4.5ppm） Hβ；β位以上の炭素についた脂肪族水素（1.1
〜2ppm） Hγ；側鎖の末端にあるメチル基水素（0.3〜
1.1ppm） 第１工程で用いられる上記重質油は、石油類を
例えばシリカ・アルミナ系分解触媒又はゼオライ
ト系分解触媒の存在下に480〜560℃程度の温度で
流動接触分解することにより得られる分解油から
の重質油であり、通常同伴された触媒粉末を多少
含んでいる。重質油は通常200〜560℃、より好ま
しくは300〜560℃程度の沸点を有する。 本発明の出発原料はこれらの重質油に含まれる
同伴触媒を除去することなくそのまま用いてもよ
く、またこれを蒸留に付して得た適宜の沸点範囲
の留分あるいは残渣油、またはこれらを熱処理し
て得たピツチでもよい。 第１工程における加熱処理は、自生圧下、350
〜550℃の範囲の温度で行われる。すなわち、原
料を密閉容器、例えばオートクレーブに仕込み、
350〜550℃の範囲の温度に加熱すると自生圧が発
生するが、本発明の第１工程はこの自生圧の下で
実施される。換言すれば、原料を密閉容器に仕込
んだのち、温度を上げる前に反応系に外部から圧
力を負荷するのではなく、加熱によつて発生する
自圧の下で加熱処理を実施する。 密閉容器に原料を仕込んだのち、容器内の雰囲
気を水素ガスで置換し、加熱処理を水素ガスを含
む雰囲気下で実施することもできる。 第１工程の加熱処理は、２〜300Kg／cm²の自生
圧下で実施するのが望ましく、３〜200Kg／cm²の
自生圧下で実施するのがさらに望ましい。またそ
の好ましい加熱温度は380〜450℃であり、その好
ましい加熱時間は５分〜２時間である。上記第１
工程の加熱処理には、シリカ−アルミナ系または
ゼオライト系分解触媒を用いることもできる。ま
た上記原料の他に、流動接触分解装置より得られ
る軽質又は重質循環油を添加して加熱処理するこ
ともできる。 本発明の第２工程では、第１工程で得られた反
応混合物から固形物、原料に含まれる触媒粉末あ
るいは使用した触媒を分離し、除去する。分離、
除去は過、好ましくは減圧ないし加圧過、あ
るいは遠心分離等によつて行うことがでる。 本発明の第３工程では、第２工程で固形物及び
触媒を分離、除去して得られた混合物（第１の処
理混合物）を250〜400℃、好ましくは320〜380℃
の範囲の温度に加熱して、上記第１工程で主とし
て生成した軽質分を、同温度下で留出する軽質留
分として除去する。 この第３工程は不活性ガス例えば窒素ガスを流
通させつつ、減圧下例えば１mmHg程度までの減
圧下で有利に実施させる。 本発明の第４工程は、本発明において特に重要
な工程である。第４工程では、上記第３工程で軽
質留分の除去された第２の処理混合物を400〜550
℃、好ましくは400〜500℃の範囲の温度でさらに
処理する。好ましくは、第４工程は不活性ガス例
えば窒素ガスを流通下で減圧下に実施される。第
４工程の加熱処理は好ましくは１〜60分間程度行
なわれる。 第４工程の処理は、紡糸性の良好なピツチを製
造するために重要である。即ち処理が不充分であ
ると、紡糸性が良好であつても軟化点の低いピツ
チしか得られず、従つてかかるピツチから炭素繊
維を得るには紡糸して得られた糸の不融化処理を
低温で長時間行なう必要があり経済的に不利とな
る。一方、過度の熱処理を行なつた場合には、得
られたピツチの軟化点が高くなりすぎ、紡糸時に
ピツチの変成がおこる。またコーキング状物質が
生成し易く紡糸時に糸切れが多発する場合が生じ
る。 第４工程の熱処理によつて、本発明によれば、
光学的異方性度が65〜95％、好ましくは70〜90％
のピツチが生成する。 第４工程の熱処理はこの得られるピツチの軟化
点が、好ましくは260〜340℃、より好ましくは
280〜320℃となるように、上記条件下で過度にな
らないように比較的短時間実施するのが有利であ
る。第４工程で得られるピツチは、トルエン不溶
解分（以下TIという）が50〜90％であり、また
キノリン不溶解分（以下QIという）が10〜40％
である。 本発明方法により製造された上記の如き原料ピ
ツチは、それ自体公知の方法に従つて紡糸口金か
ら溶融紡糸して紡糸繊維とすることができる。本
発明方法による上記原料ピツチは溶融紡糸の際に
糸切れが極めて少なく良好な紡糸性を示す。紡糸
繊維を次いで例えば200〜350℃の範囲の温度に、
空気中で15分〜２時間保持することにより、不融
化させることができる。不融化繊維はさらに不活
性ガス中1000〜2000℃で炭化して炭素繊維とする
ことができる。また必要に応じてアルゴンガス中
2000〜3000℃で焼成して黒鉛化繊維とすることも
できる。 上述のように、本発明の方法によれば、水素化
処理を行なわずに、紡糸容易なピツチが製造でき
る。しかして、本発明の第１工程において、原料
を触媒存在下または非存在下で熱処理した後のガ
ス成分を分析した結果、水素とメタンの生成が認
められたことから、この生成した水素による水素
化と芳香族側鎖の切断とが本発明の第１工程で生
じているものと思われる。 本発明で得られる原料ピツチから上記の如くし
て製造された炭素繊維は、強度、弾性率等の機械
的性質が以下の実施例において具体的に記載する
とおり極めて優れている。 なお、本明細書において、トルエン不溶解分
（TI）及びキノリン不溶解分（QI）は以下のよう
にして測定したものである。 トルエン30mlに精秤したピツチ約３ｇを入れ
て、110℃で１時間還流後、室温で不溶解分を
過分離後、100℃で減圧乾燥し重量を測定しTIを
算出する。キノリン20mlに精秤したピツチ約２ｇ
を入れて、75℃で１時間抽出後、室温で不溶解分
を過分離後、100℃で減圧乾燥し重量を測定し
QIを算出する。 また、光学的異方性度は、常温下偏光顕微鏡に
おけるピツチ試料中の光学的異方性を示す部分の
面積割合として求めた値である。具体的には、ピ
ツチ試料を数mm角に粉砕したものを、常法に従つ
て直径約２cmの樹脂に埋め込み、表面を研磨後、
偏光顕微鏡（100倍率）下で写真撮影し、試料の
全面積に占める光学的異方性部分の面積割合を測
定することによつて求める。 以下、実施例により本発明をさらに詳細に説明
する。 ［実施例］ 実施例 １ (1) 石油類を流動接触分解により処理して得られ
た重質油（以下FCCオイルという）240ｇを
500mlのオートクレーブに仕込んだ。内部の空
気を窒素ガスで置換したのち、内圧を０Kl／cm²
Ｇとした。ついで撹拌しながら、平均昇温速度
2.5℃／minで温度250℃から410℃まで加熱し、
410℃の温度で１時間保持した。オートクレー
ブ内圧は処理時間とともに高まり、最終圧力は
15.9Kg／cm²となつた。所定時間経過後、直ちに
オートクレーブを炉から取出し、室温まで冷却
した。この熱処理物を定量紙No.5Cを用い加
圧保温過して不溶分を除去した。これを撹拌
機付き三ツ口セパラブルフラスコ中で減圧蒸留
し、減圧度５mmHg以下、温度350℃以下の留分
を回収し、残渣として軟化点146℃、TI4.0％の
ピツチを70.3ｇ得た。 (2) このピツチを撹拌機付き三ツ口セパラブル容
器に入れ、あらかじめ460℃に加熱したスズ浴
上に被覆して加熱溶融させた。その後容器全体
をスズ浴中に浸漬し、それと共に窒素ガスを流
した。激しく留出物が流出した後、15分間、減
圧度３mmHgに保ち分解留出物を除去した。分
解留出物の除去が終了した後、直ちに容器をス
ズ浴から取出し、容器内を窒素ガス雰囲気に保
ちながら室温まで冷却した。このようにして、
Ｃ／Ｈ＝1.05、fa＝0.65、光学的異方性度90％、
軟化点298℃、TI85.7％、QI38.5％のピツチ
35.4ｇを得た。これを紡糸用ピツチに用いた。 (3) このピツチを孔径0.3mmのノズルを有する口
金から温度350℃にて溶融紡糸し、糸径11μｍ
のピツチ繊維を得た。このピツチは30分間以上
糸切れなく紡糸が可能であり紡糸性に優れてい
た。この繊維を空気雰囲気中で温度50℃から昇
温速度３℃／minで350℃まで加熱し、この温
度で30分間保持して不融化した。これを窒素ガ
ス中、３℃／minの昇温速度で温度1000℃まで
加熱し、この温度で30分間保持して炭素繊維を
得た。JIS R7601（炭素繊維試験方法）に従つ
て測定した炭素繊維の機械的物性は次の通りで
あつた。 強度240Kg／mm²、弾性率17.6トン／mm²、伸度
1.4％ この炭素繊維をアルゴンガス中2800℃で焼成
することにより、強度および弾性率のさらに向
上した黒鉛化繊維が得られた。黒鉛化繊維の機
械的物性は次の通りであつた。 強度332Kg／mm²、弾性率50.4t／mm²、伸度0.65
％ 実施例 ２ 原料としてFCCオイル160ｇおよび流動接触分
解装置より得られる軽質循環油（ライトサイクル
オイル、沸点範囲218℃〜352℃）80ｇを用いた以
外は実施例１の(1)と同様の方法により、加熱処
理、過および軽質分の除去を行つた。加熱処理
時の最終圧力は16.8Kg／cm²であつた。ピツチ性状
として軟化点138℃、TI8.4％のピツチ47.4ｇを得
た。このピツチを温度470℃、減圧度５mmHg、時
間13分に変えた以外は実施例１の(2)と同様の処理
を付すことにより、紡糸用ピツチ26.8ｇを得た。
このピツチは、Ｃ／Ｈ＝0.88、fa＝0.60、光学的
異方性度80％、軟化点282℃であり、またTIおよ
びQIはそれぞれ69.5％、35.8％であつた。このピ
ツチは紡糸性が良好であり、さらに実施例１の(3)
と同様の処理により強度233Kg／mm²、弾性率
16.8t／mm²、伸度1.4％の物性をもつた炭素繊維を
与えた。 実施例 ３ FCCオイル240ｇにシリカ−アルミナ触媒24ｇ
を加え、410℃の温度で30分間保持した以外は実
施例１の(1)と同様の方法により、加熱処理、過
および軽質分の除去を行つた。加熱処理時の最終
圧力は17.2Kg／cm²であつた。ピツチ性状として軟
化点133℃、TI3.2％のピツチ45.6ｇを得た。この
ピツチを温度470℃に変えた以外は実施例１の(2)
と同様の処理を付すことにより、紡糸用ピツチ
37.4ｇを得た。このピツチは、Ｃ／Ｈ＝0.82、fa
＝0.53、光学的異方性度70％、軟化点276℃であ
り、またTIおよびQIはそれぞれ60.5％、28.8％で
あつた。このピツチは紡糸性が良好であり、さら
に実施例１の(3)と同様の処理により強度222Kg／
mm²、弾性率16.3t／mm²、伸度1.4％の物性をもつた
炭素繊維を与えた。 実施例 ４ 原料としてFCCオイル160ｇおよび流動接触分
解装置より得られる軽質循環油80ｇにゼオライト
触媒24ｇを加え、410℃で20分間保持した以外は
実施例１の(1)と同様の方法により、加熱処理、
過および軽質分の除去を行つた。加熱処理時の最
終圧力は17.5Kg／cm²であつた。ピツチ性状として
軟化点148℃、TI13.7％のピツチ36.2ｇを得た。
このピツチを実施例１の(2)と同様の処理を付すこ
とにより、紡糸用ピツチ19.2ｇを得た。このピツ
チは、Ｃ／Ｈ＝0.91、fa＝0.63、光学的異方性度
80％、軟化点313℃、でありまたTIおよびQIはそ
れぞれ87.7％、38.5％であつた。このピツチは紡
糸性が良好であり、さらに実施例１の(3)と同様の
処理により強度228Kg／mm²、弾性率15.5t／mm²、伸
度1.5％の物性をもつた炭素繊維を与えた。 実施例 ５ 原料としてFCCオイルのうち常圧換算、沸点
490℃以上の留分および流動接触分解装置より得
られる軽質循環油120ｇを仕込み、410℃の温度で
20分間保持した以外は実施例１の(1)と同様の方法
により、加熱処理、過および軽質分の除去を行
つた。加熱処理時の最終圧力は10.2Kg／cm²であつ
た。ピツチ性状として軟化点136℃、TI6.0％のピ
ツチ69.6ｇを得た。このピツチを実施例１の(2)と
同様の処理を付すことにより、紡糸用ピツチ22.8
ｇを得た。このピツチは、Ｃ／Ｈ＝1.22、fa＝
0.79、光学的異方性度90％、軟化点308℃であり、
またTIおよびQIはそれぞれ84.7％、35.5％であつ
た。このピツチを温度345℃にて紡糸し、さらに
実施例１の(3)と同様の処理により強度222Kg／mm²、
弾性率14.9t／mm²、伸度1.5％の物性をもつた炭素
繊維を与えた。 実施例 ６ 原料としてFCCオイルのうち常圧換算、沸点
400℃以上の留分160ｇ、流動接触分解装置より得
られる軽質循環油80ｇおよびゼオライト系触媒36
ｇ仕込み、410℃の温度で５分間保持した以外は
実施例１の(1)と同様の方法により、加熱処理、
過および軽質分の除去を行つた。加熱処理時の最
終圧力は5.8Kg／cm²であつた。ピツチ性状として
軟化点141℃、TI9.7％のピツチ98.3ｇを得た。こ
のピツチを実施例１の(2)と同様の処理を付すこと
により、紡糸用ピツチ34.7ｇを得た。このピツチ
は、Ｃ／Ｈ＝1.12、fa＝0.71、光学的異方性度70
％、軟化点297℃であり、またTIおよびQIはそれ
ぞれ81.7％、36.3％であつた。このピツチを温度
330℃にて紡糸し、さらに実施例１の(3)と同様の
処理により強度207Kg／mm²、弾性率13.7t／mm²、伸
度1.5％の物性をもつた炭素繊維を与えた。 実施例 ７〜10 オートクレーブ処理時の温度および時間を第１
表に記載のように変えた以外は実施例１と同様の
方法を繰返して炭素繊維を製造した。 得られた紡糸用ピツチ及び炭素繊維の特性を第
１表に示す。 【表】DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing carbon fiber raw material pitch. More specifically, the present invention relates to a method for producing carbon fiber raw material pitch which provides carbon fibers with good spinnability and excellent mechanical properties. [Prior Art] Conventionally, methods for producing carbon fibers using various pitches as raw materials have been known. In order to produce carbon fibers for HP products using pitches as raw materials, the pitches used for spinning must have optically anisotropic properties, that is, mesophase carbonaceous materials, and this is already known. . However, even if mesophase pitches are prepared by heat treatment without pre-treating pitches, it is not possible to obtain pitches with good spinnability. Therefore, several methods have been proposed as pretreatment methods, and the representative method is a hydrogenation treatment method. Japanese Patent Publication No. 57-179286 states that the raw material pits are (1) 100 parts by volume of heavy oil with a boiling point of 200°C or higher obtained from fluid catalytic cracking of petroleum, and (2) boiling points of 160 to 160°C from pitch. Hydrogenated oil of fractions in the range of 400℃ 10~
200 parts by volume, and use a mixture of 380 to 480 parts by volume.
A method for producing a carbon fiber raw material pitch by heat treatment at a temperature of 2°C and a pressure of 2 to 50 kg/cm ² G is disclosed. Furthermore, in JP-A No. 57-168989, heavy oil with a boiling point of 200°C or more obtained when petroleum is subjected to fluid catalytic cracking is heated at a temperature of 400 to 400°C under a hydrogen pressure of 20 kg/cm ² G or more.
A method for producing carbon fiber raw material pitches by heat treatment at 500°C is described. Furthermore, in Japanese Patent Application Laid-open No. 58-18421, a pitch-like substance mainly composed of optically isotropic PRIMESOPHACE carbonaceous material or optically isotropic PRIMESOPHACE carbonaceous material is substantially mesophase By spinning under conditions that do not increase the amount of carbonaceous matter, followed by infusibility treatment, and then carbonization treatment to convert substantially all of the primesophace carbonaceous matter into optically anisotropic mesophace carbonaceous matter. A method for manufacturing carbon fiber is described. The optically isotropic primesophace carbonaceous material used in this method is prepared by treating pitch with expensive tetrahydroquinoline, with quinoline and hydrogen in the presence of a catalyst, or with aromatic hydrocarbons and hydrogen. The same publication states that it can be manufactured by: however,
Tetrahydroquinoline is very expensive, so it is difficult to use it industrially. In addition, JP-A-59-196390 discloses that coal tar and coal tar pitch are treated under autogenous pressure in the presence or absence of an aromatic oil and a catalytic cracking catalyst.
A method for producing carbon fiber raw material pitch is described by treating at 350 to 500°C for 10 to 60 minutes, then removing solid insoluble matter, and then treating at a temperature of 430°C or higher for up to 60 minutes under normal pressure or reduced pressure. ing. The publication states that if naphsatal, which is a petroleum-based pitch, is used as a raw material instead of the coal-based pitch, pitch with excellent spinnability cannot be obtained. As seen in these methods, subjecting the raw material pitch to hydrogenation treatment in advance is an extremely effective method for producing pitch that is easy to spin.
However, performing hydrogenation treatment brings about an increase in manufacturing costs. [Problems to be Solved by the Invention] An object of the present invention is to provide a novel method for producing carbon fiber raw material pitch. Another object of the present invention is to provide a novel method for producing carbon fiber raw material pitch exhibiting good spinnability from fluidized catalytic cracking residue oil. Still another object of the present invention is to provide a novel method for producing carbon fiber raw material pitch that provides carbon fibers with excellent mechanical performance. Still another object of the present invention is to provide a new method for producing carbon fiber raw material pitch having the above-mentioned excellent properties with simple operations. [Means and effects for solving the problems] According to the present invention, the objects and advantages of the present invention are as follows: (1) heavy oil obtained by fluid catalytic cracking of petroleum, distilling the heavy oil; at least one component selected from the group consisting of distillate components or residual oils obtained by heat-treating them, and pitch obtained by heat-treating them, the atomic ratio of carbon atoms to hydrogen atoms (C/H) is
Aromatic carbon fraction (fa) in the range of 0.7 to 1.4
Raw materials with a range of 0.4 to 0.9 are subjected to autogenous pressure, 350
(2) Separate and remove solids and catalyst powder contained in the raw materials from the reaction mixture obtained in step (1) to obtain a first treated mixture; (3) The first treatment mixture obtained in step (2) above was
heating to a temperature in the range of ~400°C and removing light fractions distilled out at the same temperature to obtain a second treated mixture;
and (4) the second treatment mixture obtained in step (3) above at 400%
This is achieved by a method for producing a pitch of carbon fiber raw material, characterized in that the pitch is further processed at a temperature in the range of ~550°C to produce pitch with an optical anisotropy of 65-95%. In the first step (step (1)) of the present invention, as the starting material of the present invention, distillate components or residual oil obtained by distilling heavy oil obtained by fluid catalytic cracking of petroleum, or the like are used. At least one of the pitches obtained by heat treatment is used. These components used as raw materials have an atomic ratio of carbon atoms to hydrogen atoms (C/H) in the range of 0.7 to 1.4, preferably 0.8 to 1.3. These atomic ratios are calculated from the results of elemental analysis performed on each component. In addition, these ingredients used as raw materials are
Aromatic carbon fraction (fa) is 0.4-0.9, preferably 0.5
~0.8. The aromatic carbon fraction (fa) was determined by the conventional Brown-Landner method from the results of ¹ H-NMR measurement by adding tetramethylsilane as an internal standard to a solution of 0.05 g of the raw material dissolved in 1 g of deuterated chloroform. It is calculated by the following formula based on fa=C/H−(Hα+Hβ)/2H/Hγ/3H/C/H fa; aromatic carbon fraction Ha; aromatic hydrogen (6 to 10 ppm) Hα; aliphatic hydrogen attached to α carbon (2 to
4.5ppm) Hβ; aliphatic hydrogen attached to carbons above the β position (1.1
~2ppm) Hγ; methyl group hydrogen at the end of the side chain (0.3~
1.1ppm) The above-mentioned heavy oil used in the first step is obtained by fluid catalytic cracking of petroleum at a temperature of about 480 to 560°C in the presence of, for example, a silica/alumina cracking catalyst or a zeolite cracking catalyst. Heavy oil from cracked oil and usually contains some entrained catalyst powder. Heavy oil usually has a boiling point of about 200 to 560°C, more preferably about 300 to 560°C. The starting materials of the present invention may be used as they are without removing the entrained catalyst contained in these heavy oils, or may be distilled from these heavy oils and used as distillates or residual oils with an appropriate boiling point range, or Pitch obtained by heat-treating may also be used. The heat treatment in the first step is under autogenous pressure, 350
Performed at temperatures ranging from ~550°C. That is, the raw materials are placed in a closed container, such as an autoclave,
Heating to a temperature in the range of 350 to 550° C. generates an autogenous pressure, and the first step of the present invention is carried out under this autogenous pressure. In other words, after the raw materials are charged into a closed container, the heat treatment is performed under the natural pressure generated by heating, rather than applying external pressure to the reaction system before raising the temperature. After charging the raw materials into a sealed container, the atmosphere inside the container may be replaced with hydrogen gas, and the heat treatment may be performed in an atmosphere containing hydrogen gas. The heat treatment in the first step is desirably carried out under an autogenous pressure of 2 to 300 Kg/cm ² , more desirably carried out under an autogenous pressure of 3 to 200 Kg/cm ² . Further, the preferable heating temperature is 380 to 450°C, and the preferable heating time is 5 minutes to 2 hours. 1st above
A silica-alumina-based or zeolite-based decomposition catalyst can also be used for the heat treatment in the process. In addition to the above raw materials, light or heavy circulating oil obtained from a fluid catalytic cracker can also be added and heat treated. In the second step of the present invention, solids, catalyst powder contained in the raw materials, or used catalyst are separated and removed from the reaction mixture obtained in the first step. separation,
Removal can be carried out by filtration, preferably reduced pressure or increased pressure, or centrifugation. In the third step of the present invention, the mixture obtained by separating and removing the solids and catalyst in the second step (first treatment mixture) is heated to 250 to 400°C, preferably 320 to 380°C.
The light fraction mainly produced in the first step is removed as a light fraction distilled out at the same temperature. This third step is advantageously carried out under reduced pressure, for example to about 1 mmHg, while passing an inert gas such as nitrogen gas. The fourth step of the present invention is a particularly important step in the present invention. In the fourth step, the second treated mixture from which light fractions have been removed in the third step is heated to 400 to 550
Further processing at a temperature in the range of 400-500°C. Preferably, the fourth step is carried out under reduced pressure while passing an inert gas such as nitrogen gas. The heat treatment in the fourth step is preferably performed for about 1 to 60 minutes. The treatment in the fourth step is important for producing pitch with good spinnability. In other words, if the treatment is insufficient, even if the spinnability is good, only a pitch with a low softening point can be obtained. Therefore, in order to obtain carbon fiber from such pitch, it is necessary to infusibility treatment of the yarn obtained by spinning. It is economically disadvantageous because it must be carried out at low temperatures for a long time. On the other hand, if excessive heat treatment is performed, the softening point of the pitch obtained will become too high, and the pitch will be denatured during spinning. Further, caulking-like substances are likely to be formed, and yarn breakage may occur frequently during spinning. According to the present invention, by the heat treatment in the fourth step,
Optical anisotropy degree of 65-95%, preferably 70-90%
The pitch is generated. The fourth step of heat treatment is such that the softening point of the resulting pitch is preferably 260 to 340°C, more preferably
It is advantageous to carry out the reaction at a temperature of 280 DEG -320 DEG C. under the above conditions for a relatively short time without being excessive. The pitch obtained in the fourth step has a toluene insoluble content (hereinafter referred to as TI) of 50 to 90% and a quinoline insoluble content (hereinafter referred to as QI) of 10 to 40%.
It is. The above-mentioned raw material pitch produced by the method of the present invention can be melt-spun into spun fibers from a spinneret according to a method known per se. The raw material pitch produced by the method of the present invention exhibits good spinnability with very little yarn breakage during melt spinning. The spun fibers are then brought to a temperature in the range of e.g. 200-350°C,
It can be made infusible by holding it in air for 15 minutes to 2 hours. The infusible fibers can be further carbonized at 1000 to 2000°C in an inert gas to form carbon fibers. Also, if necessary,
Graphitized fibers can also be produced by firing at 2000 to 3000°C. As described above, according to the method of the present invention, pitches that are easy to spin can be produced without hydrogenation treatment. However, in the first step of the present invention, as a result of analyzing the gas components after heat-treating the raw material in the presence or absence of a catalyst, it was found that hydrogen and methane were produced. It is believed that the conversion and cleavage of aromatic side chains occur in the first step of the present invention. The carbon fiber produced as described above from the raw material pitch obtained in the present invention has extremely excellent mechanical properties such as strength and elastic modulus, as will be specifically described in the following examples. In addition, in this specification, toluene insoluble content (TI) and quinoline insoluble content (QI) are measured as follows. Approximately 3 g of precisely weighed pitch is placed in 30 ml of toluene, refluxed at 110°C for 1 hour, and after over-separating the insoluble matter at room temperature, the mixture is dried under reduced pressure at 100°C, the weight is measured, and the TI is calculated. Approximately 2g of pitchch accurately weighed in 20ml of quinoline
After extracting at 75°C for 1 hour, remove the insoluble matter at room temperature, dry under reduced pressure at 100°C, and measure the weight.
Calculate QI. Further, the degree of optical anisotropy is a value determined as the area ratio of a portion exhibiting optical anisotropy in a pitch sample under a polarizing microscope at room temperature. Specifically, a pitch sample was crushed into pieces several mm square, embedded in resin with a diameter of about 2 cm according to the usual method, and after polishing the surface,
It is determined by taking a photograph under a polarizing microscope (100x magnification) and measuring the area ratio of the optically anisotropic portion to the total area of the sample. Hereinafter, the present invention will be explained in more detail with reference to Examples. [Example] Example 1 (1) 240 g of heavy oil (hereinafter referred to as FCC oil) obtained by treating petroleum by fluid catalytic cracking was
It was placed in a 500ml autoclave. After replacing the internal air with nitrogen gas, reduce the internal pressure to 0 Kl/cm ²
It was set as G. Then, while stirring, the average temperature increase rate
Heating from 250℃ to 410℃ at 2.5℃/min,
The temperature was kept at 410°C for 1 hour. The autoclave internal pressure increases with processing time, and the final pressure is
It became 15.9Kg/cm ² . Immediately after the predetermined time had elapsed, the autoclave was taken out of the furnace and cooled to room temperature. This heat-treated product was subjected to pressurization and heat retention using quantitative paper No. 5C to remove insoluble matter. This was distilled under reduced pressure in a three-necked separable flask equipped with a stirrer, and a fraction with a degree of vacuum of 5 mmHg or less and a temperature of 350°C or less was collected, and 70.3 g of pitch was obtained as a residue with a softening point of 146°C and a TI of 4.0%. (2) This pitch was placed in a three-necked separable container equipped with a stirrer, coated on a tin bath preheated to 460°C, and heated to melt. The entire container was then immersed in a tin bath and nitrogen gas was passed along with it. After the distillate had flowed out vigorously, the decomposition degree was maintained at 3 mmHg for 15 minutes to remove the cracked distillate. Immediately after the removal of the cracked distillate was completed, the container was taken out from the tin bath and cooled to room temperature while maintaining the inside of the container in a nitrogen gas atmosphere. In this way,
C/H=1.05, fa=0.65, optical anisotropy 90%,
Pitch with softening point 298℃, TI85.7%, QI38.5%
35.4g was obtained. This was used as a spinning pitch. (3) This pitch was melt-spun at a temperature of 350°C from a nozzle with a hole diameter of 0.3 mm, and the thread diameter was 11 μm.
Pitch fibers were obtained. This pitch could be spun for more than 30 minutes without yarn breakage, and had excellent spinning properties. This fiber was heated in an air atmosphere from 50°C to 350°C at a heating rate of 3°C/min, and held at this temperature for 30 minutes to make it infusible. This was heated in nitrogen gas at a heating rate of 3°C/min to a temperature of 1000°C and held at this temperature for 30 minutes to obtain carbon fibers. The mechanical properties of the carbon fiber measured according to JIS R7601 (carbon fiber testing method) were as follows. Strength 240Kg/mm ² , Modulus of elasticity 17.6 tons/mm ² , Elongation
1.4% By firing this carbon fiber at 2800°C in argon gas, a graphitized fiber with further improved strength and elastic modulus was obtained. The mechanical properties of the graphitized fibers were as follows. Strength 332Kg/mm ² , elastic modulus 50.4t/mm ² , elongation 0.65
% Example 2 The same method as in Example 1 (1) was used except that 160 g of FCC oil and 80 g of light circulating oil (light cycle oil, boiling point range 218°C to 352°C) obtained from a fluid catalytic cracker were used as raw materials. , heat treatment, and removal of excess and light components. The final pressure during the heat treatment was 16.8 Kg/cm ² . 47.4 g of pitch was obtained with a softening point of 138° C. and a TI of 8.4%. This pitch was subjected to the same treatment as in Example 1 (2) except that the temperature was changed to 470° C., the degree of vacuum was changed to 5 mmHg, and the time was changed to 13 minutes to obtain 26.8 g of pitch for spinning.
This pitch had C/H=0.88, fa=0.60, optical anisotropy of 80%, softening point of 282°C, and TI and QI of 69.5% and 35.8%, respectively. This pitch has good spinnability, and in addition, (3) of Example 1
After the same treatment, the strength was 233Kg/mm ² and the elastic modulus was
Carbon fibers with physical properties of 16.8t/mm ² and elongation of 1.4% were obtained. Example 3 240g of FCC oil and 24g of silica-alumina catalyst
was added, and heat treatment and removal of light components were carried out in the same manner as in Example 1 (1), except that the mixture was held at a temperature of 410° C. for 30 minutes. The final pressure during the heat treatment was 17.2 Kg/cm ² . 45.6 g of pitch was obtained with a softening point of 133° C. and a TI of 3.2%. (2) of Example 1 except that the temperature of this pitch was changed to 470°C.
By applying the same treatment as
37.4g was obtained. This pitch is C/H=0.82, fa
= 0.53, the degree of optical anisotropy was 70%, the softening point was 276°C, and the TI and QI were 60.5% and 28.8%, respectively. This pitch had good spinnability, and was further treated in the same manner as in Example 1 (3) to have a strength of 222 kg/
mm ² , elastic modulus of 16.3 t/mm ² , and elongation of 1.4%. Example 4 24 g of zeolite catalyst was added to 160 g of FCC oil as raw materials and 80 g of light circulating oil obtained from a fluid catalytic cracker, and heated in the same manner as in (1) of Example 1, except that the mixture was held at 410°C for 20 minutes. process,
filtration and removal of light components. The final pressure during the heat treatment was 17.5 Kg/cm ² . 36.2 g of pitch was obtained with a softening point of 148° C. and a TI of 13.7%.
This pitch was subjected to the same treatment as in Example 1 (2) to obtain 19.2 g of spinning pitch. This pitch is C/H=0.91, fa=0.63, optical anisotropy
The softening point was 80%, the softening point was 313°C, and the TI and QI were 87.7% and 38.5%, respectively. This pitch has good spinnability, and by the same treatment as in Example 1 (3), carbon fibers with physical properties of strength 228 Kg/mm ² , elastic modulus 15.5 t/mm ² , and elongation 1.5% can be obtained. Ta. Example 5 FCC oil as raw material, boiling point converted to normal pressure
120g of light circulating oil obtained from a fluidized catalytic cracker and a distillate of 490℃ or higher are charged, and the mixture is heated at a temperature of 410℃.
Heat treatment, removal of filtrate and light components were performed in the same manner as in Example 1 (1) except that the mixture was held for 20 minutes. The final pressure during the heat treatment was 10.2 Kg/cm ² . 69.6 g of pitches having a softening point of 136° C. and a TI of 6.0% were obtained. By subjecting this pitch to the same treatment as in (2) of Example 1, a spinning pitch of 22.8
I got g. This pitch is C/H=1.22, fa=
0.79, optical anisotropy 90%, softening point 308℃,
Furthermore, TI and QI were 84.7% and 35.5%, respectively. This pitch was spun at a temperature of 345°C, and further treated in the same manner as in Example 1 (3) to obtain a strength of 222 Kg/mm ² .
A carbon fiber with physical properties of an elastic modulus of 14.9 t/mm ² and an elongation of 1.5% was obtained. Example 6 FCC oil as raw material, boiling point converted to normal pressure
160g of distillate above 400℃, 80g of light circulating oil obtained from a fluid catalytic cracker, and 36g of zeolite catalyst
Heat treatment,
filtration and removal of light components. The final pressure during the heat treatment was 5.8 Kg/cm ² . 98.3 g of pitch was obtained with a softening point of 141° C. and a TI of 9.7%. This pitch was subjected to the same treatment as in (2) of Example 1 to obtain 34.7 g of pitch for spinning. This pitch is C/H=1.12, fa=0.71, optical anisotropy 70
%, the softening point was 297°C, and the TI and QI were 81.7% and 36.3%, respectively. Temperature this pitch
Carbon fibers were spun at 330° C. and further treated in the same manner as in Example 1 (3) to obtain carbon fibers having physical properties of strength 207 Kg/mm ² , elastic modulus 13.7 t/mm ² , and elongation 1.5%. Examples 7 to 10 The temperature and time during autoclave treatment were
Carbon fibers were produced by repeating the same method as in Example 1 except for the changes shown in the table. Table 1 shows the properties of the spinning pitch and carbon fiber obtained. 【table】

Claims (1)

【特許請求の範囲】 １ (1) 石油類の流動接触分解により得られる重
質油、その重質油を蒸留して得た留出成分又は
残渣油およびそれらを熱処理して得られたピツ
チより成る群から選ばれる少なくとも１種の成
分であつて、炭素原子対水素原子の原子比
（Ｃ／Ｈ）が0.7〜1.4の範囲にありしかも芳香
族炭素分率（fa）が0.4〜0.9の範囲にある原料
を、自生圧下、350〜550℃の範囲の温度で加熱
処理し、 (2) 上記工程(1)で得られた反応混合物から固形物
及び原料に含まれる触媒粉末を分離除去して第
１の処理混合物を得、 (3) 上記工程(2)で得られた第１の処理混合物を
250℃〜400℃の範囲の温度に加熱して同温度下
で留出する軽質留分を除去して第２の処理混合
物を得、そして (4) 上記工程(3)で得られた第２の処理混合物を
400℃〜550℃の範囲の温度でさらに処理して光
学的異方性度が65〜95％であるピツチを生成す
る、 ことを特徴とする炭素繊維原料ピツチの製造法。 ２ 工程(1)で用いられる原料が、石油類を分解触
媒の存在下480〜560℃の温度で流動接触分解する
ことによつて得られた分解油からの重質油（同伴
される分解触媒粉末を除去していないもの）、そ
の重質油の蒸留留出成分又は蒸留残渣、あるいは
それらを熱処理して得たピツチである特許請求の
範囲第１項に記載の方法。 ３ 工程(1)で加熱処理を２〜300Kg／cm²の自生圧
下で実施する特許請求の範囲第１項に記載の方
法。 ４ 工程(1)の加熱処理を３〜200Kg／cm²の自生圧
下で実施する特許請求の範囲第１項に記載の方
法。 ５ 工程(1)の加熱処理を分解触媒の存在下で実施
する特許請求の範囲第１項に記載の方法。 ６ 工程(1)の加熱処理を400〜550℃の温度で実施
する特許請求の範囲第１項に記載の方法。 ７ 工程(1)の加熱処理の時間が５分〜２時間であ
る特許請求の範囲第１項に記載の方法。 ８ 工程(1)の加熱処理を実施する前に雰囲気を水
素ガスで置換し、該加熱処理を水素ガスを含む雰
囲気下で実施する特許請求の範囲第１項に記載の
方法。 ９ 工程(1)の加熱処理を、上記原料に、流動接触
分解装置より得られる軽質又は重質循環油を添加
して実施する特許請求の範囲第１項に記載の方
法。 １０ 工程(2)の固形物及び原料に含まれる触媒粉
末および工程(2)の実施のため加えた添加触媒との
分離除去を過又は遠心分離によつて行なう特許
請求の範囲第１項に記載の方法。 １１ 工程(3)の加熱を320〜380℃の範囲の温度で
実施する特許請求の範囲第１項に記載の方法。 １２ 工程(3)の加熱を不活性ガスの雰囲気中、減
圧下で実施する特許請求の範囲第１項に記載の方
法。 １３ 工程(4)の加熱処理を400〜500℃の範囲の温
度で実施する特許請求の範囲第１項に記載の方
法。 １４ 工程(4)の加熱処理の時間が１〜60分間であ
る特許請求の範囲第１項に記載の方法。 １５ 工程(4)の加熱処理を不活性ガスの雰囲気
中、減圧下で実施する特許請求の範囲第１項に記
載の方法。 １６ 工程(4)で生成するピツチが260〜340℃の範
囲の軟化点を有する特許請求の範囲第１項に記載
の方法。 １７ 工程(4)で生成するピツチが50〜90％のトル
エン不溶解分を有する特許請求の範囲第１項に記
載の方法。 １８ 工程(4)で生成するピツチが10〜40％のキノ
リン不溶解分を有する特許請求の範囲第１項に記
載の方法。 １９ 工程(4)で生成するピツチが70〜90％の光学
的異方性度を有する特許請求の範囲第１項に記載
の方法。[Scope of Claims] 1 (1) From heavy oil obtained by fluid catalytic cracking of petroleum, distillate components or residual oil obtained by distilling the heavy oil, and pitts obtained by heat treating them. At least one component selected from the group consisting of carbon atoms to hydrogen atoms (C/H) in the range of 0.7 to 1.4 and aromatic carbon fraction (fa) in the range of 0.4 to 0.9. (2) Separate and remove the solids and catalyst powder contained in the raw materials from the reaction mixture obtained in step (1) above. (3) obtain the first treated mixture obtained in step (2) above;
heating to a temperature in the range of 250°C to 400°C to remove light fractions distilled out at the same temperature to obtain a second treated mixture; and (4) the second treated mixture obtained in step (3) above. processing mixture of
A method for producing carbon fiber raw material pitch, comprising further processing at a temperature in the range of 400°C to 550°C to produce pitch having an optical anisotropy of 65 to 95%. 2 The raw material used in step (1) is heavy oil obtained from cracked oil obtained by fluid catalytic cracking of petroleum at a temperature of 480 to 560°C in the presence of a cracking catalyst (with no accompanying cracking catalyst). 2. The method according to claim 1, which is a distillate component or distillation residue of heavy oil (from which powder has not been removed), a distillate component or distillation residue of the heavy oil, or pitch obtained by heat-treating them. 3. The method according to claim 1, wherein the heat treatment in step (1) is carried out under an autogenous pressure of 2 to 300 Kg/cm ² . 4. The method according to claim 1, wherein the heat treatment in step (1) is carried out under an autogenous pressure of 3 to 200 kg/cm ² . 5. The method according to claim 1, wherein the heat treatment in step (1) is carried out in the presence of a decomposition catalyst. 6. The method according to claim 1, wherein the heat treatment in step (1) is carried out at a temperature of 400 to 550°C. 7. The method according to claim 1, wherein the heat treatment time in step (1) is 5 minutes to 2 hours. 8. The method according to claim 1, wherein the atmosphere is replaced with hydrogen gas before performing the heat treatment in step (1), and the heat treatment is performed in an atmosphere containing hydrogen gas. 9. The method according to claim 1, wherein the heat treatment in step (1) is carried out by adding light or heavy circulating oil obtained from a fluid catalytic cracker to the raw material. 10 The catalyst powder contained in the solids and raw materials in step (2) and the added catalyst added for carrying out step (2) are separated and removed by filtration or centrifugation, as set forth in claim 1. the method of. 11. The method according to claim 1, wherein the heating in step (3) is carried out at a temperature in the range of 320 to 380°C. 12. The method according to claim 1, wherein the heating in step (3) is carried out under reduced pressure in an inert gas atmosphere. 13. The method according to claim 1, wherein the heat treatment in step (4) is carried out at a temperature in the range of 400 to 500°C. 14. The method according to claim 1, wherein the heat treatment time in step (4) is 1 to 60 minutes. 15. The method according to claim 1, wherein the heat treatment in step (4) is carried out under reduced pressure in an inert gas atmosphere. 16. The method according to claim 1, wherein the pitch produced in step (4) has a softening point in the range of 260 to 340°C. 17. The method according to claim 1, wherein the pitch produced in step (4) has a toluene insoluble content of 50 to 90%. 18. The method according to claim 1, wherein the pitch produced in step (4) has a quinoline insoluble content of 10 to 40%. 19. The method according to claim 1, wherein the pitch produced in step (4) has a degree of optical anisotropy of 70 to 90%.