JPS6134222A - Production of carbon fiber - Google Patents

Abstract

PURPOSE:To reduce remarkably the treating time and obtain carbon fibers at a low cost, by infusibilizing spun pitch fibers at a specific temperature under a specific pressure in an oxidizing atmosphere. CONSTITUTION:Pitch fibers obtained by spinning petroleum based or coal based pitch as a raw material are infusibilized at 200-400 deg.C under >=0.1kg/cm<2>.G pressure, preferably >=0.5kg/cm<2>.G pressure in an oxidizing atmosphere, e.g. atmosphere containing oxygen, and heated to 900-1,200 deg.C at 20-50 deg.C/min heating rate in the presence of an inert gas, e.g. N2, and kept and carbonized at the temperature for 1-10min according to the conventional method to afford the aimed carbon fibers.

Description

【発明の詳細な説明】 産業上の利用分舒 本発明は、炭素繊維の製造方法に関し、更に詳しくは、
石油系又は石炭系ピッチを原料とする炭素繊維の製造方
法の改良に関する。DETAILED DESCRIPTION OF THE INVENTION Industrial Application The present invention relates to a method for producing carbon fiber, and more specifically,
This invention relates to improvements in the manufacturing method of carbon fiber using petroleum-based or coal-based pitch as a raw material.

−従一嵐」２」Ｌ璽− 石油系又は石炭系ピッチを溶融紡糸し、不融化処理し、
焼成することによシ炭素繊維を製造するに際し、炭素繊
維製造原価に占める不融化処理費用の割合は、非常に大
きいので、不敵化処理時間の短縮は、生産性向上及び運
転費用の軽減の観点から極めて重要でらる◎ 従来、紡糸ピッチの不融化は、主に以下の如き条件下に
行なわれて−る。- Juichi Arashi 2" L seal - Melt-spun petroleum-based or coal-based pitch, treated to make it infusible,
When manufacturing carbon fibers by firing, the cost of infusibility treatment accounts for a very large portion of the carbon fiber production cost, so shortening the time for infusibility treatment is an important way to improve productivity and reduce operating costs. Very important from this point of view ◎ Conventionally, infusibility of spinning pitch has been mainly carried out under the following conditions.

（１）　　紡糸ピッチを空気気流中、０．５〜ｂ昇温速
度で２５０〜３５０°Ｃ４で加熱し、５〜３０分間維持
する（特開昭５８−１８４２１号公報）。(1) The spinning pitch is heated at 250 to 350°C4 in an air stream at a temperature increase rate of 0.5 to b and maintained for 5 to 30 minutes (Japanese Patent Laid-Open No. 18421/1983).

（２）　　ＪＪ１素ガスと酸素ガスとからなる雰囲気中
で紡糸ピッチを３００〜３５０℃で５分間以上保持する
（特開昭４９−７５８２８号公報）。(2) The spinning pitch is maintained at 300 to 350° C. for 5 minutes or more in an atmosphere consisting of JJ1 elementary gas and oxygen gas (Japanese Patent Application Laid-open No. 75828/1983).

＜３）　　ＮＯ，ＮＯ２等を含む空気算器気中で紡糸ピ
ッチを４時間かけて１００〜３００℃まで昇温する（特
開昭５５−９８９１４号公報）。<3) The temperature of the spinning pitch is raised to 100 to 300° C. over 4 hours in an air calculator containing NO, NO2, etc. (Japanese Patent Laid-Open No. 55-98914).

発明が解決しようとする問題点 しかしながら、これ等の公知の不融化処理方法は、処理
時間が長いので、前述の如く、炭１Ａ繊維の製造原価低
下の障害と々うておシ、又（２）及び（３）の方法では
雰囲気ガス中に必須成分として含まれる有毒１５スが作
業′ＥＡ＋Ａを悪化させたシ、装置類を腐食させたシす
るおそれがおる。Problems to be Solved by the Invention However, these known infusibility treatment methods require a long treatment time, which, as mentioned above, poses an obstacle to reducing the manufacturing cost of charcoal 1A fibers, and (2) In methods () and (3), there is a risk that the toxic 15-sulfur contained as an essential component in the atmospheric gas may worsen the work 'EA+A' and corrode the equipment.

問題点を解決するための手段 本発明者は、上記の如き従来技術の問題点に鑑みて種々
研究を重ねた結果、紡糸したピッチ繊維を特定の加圧及
び加熱条件下に不敵化処理する場合には、所要時間が大
巾に短縮されることを見出し、本発明を完成するにいた
った。即ち、本発明は、石油系又は石炭系ピッチを原料
とする炭素繊維の製造方法において、紡糸したピッチ繊
維を酸化性雰囲気中でＯ，Ｉ＃／ｄ、０以上の加圧下に
２００〜４００℃で不融化処理することを特徴とする炭
素繊維の製造方法に係る。Means for Solving the Problems The present inventor has conducted various studies in view of the problems of the prior art as described above, and as a result, has devised a process to render spun pitch fibers invulnerable under specific pressure and heating conditions. In some cases, the required time can be significantly shortened, leading to the completion of the present invention. That is, the present invention provides a method for producing carbon fibers using petroleum-based or coal-based pitch as a raw material, in which spun pitch fibers are heated in an oxidizing atmosphere at 200 to 400°C under pressure of O, I#/d, 0 or more. The present invention relates to a method for producing carbon fiber, which is characterized by carrying out an infusibility treatment.

本発明で紡糸原料として使用するピッチは、石油系又は
石炭系の重質油（例えば石油蒸留残渣、ナフサ分解残渣
、エチレンボトム油、石炭液化油、コールタール等）を
常法に従い、例えば固形分除去、による精製、減ＥＥ蒸
留による軽質分の除去、重縮合反応、水素化反応等の処
理を行なうことによル得られる。The pitch used as a spinning raw material in the present invention is obtained by converting petroleum-based or coal-based heavy oil (e.g., petroleum distillation residue, naphtha decomposition residue, ethylene bottom oil, coal liquefied oil, coal tar, etc.) according to a conventional method, for example, to reduce the solid content. It can be obtained by purification by removal, removal of light components by reduced EE distillation, polycondensation reaction, hydrogenation reaction, etc.

原料ピッチの紡糸も、溶融押出し紡糸法、吹き込み紡糸
法、遠心紡糸法等の公知の紡糸法によシ行なうことがで
きる◎例えば、溶融押出し紡糸法による場合には、原料
ピッチを紡糸器に供給し、所定温度に加熱した状態で不
活性ガスによる加圧下にノズルから押出し、紡糸ピッチ
繊維とすれば良い。Spinning of raw material pitch can also be performed by known spinning methods such as melt extrusion spinning, blow spinning, centrifugal spinning, etc. ◎For example, in the case of melt extrusion spinning, raw material pitch is supplied to a spinning machine. Then, while heated to a predetermined temperature, it may be extruded from a nozzle under pressure with an inert gas to produce spun pitch fibers.

本発明においては、紡糸ピッチ繊維の不融化処理を機素
含有雰囲気等の酸化性雰囲気中で０．１　ｋｇ／ｄ、０
以上の加圧下好ましくは０．５に９／１４−０以上の加
圧下且つ２００〜４００°Ｃの加熱下で行なう。かくし
て、ｖ４維の太さ、原料ピッチの性状等によっても異な
るが、通常１時間程度以内、最適条件においては１分間
程度の極めて短い時間内に不融化処理が完了する。本発
明において採用する酸素含有雰囲気ガスとしては、酸素
、酸素富化空気、空気等が例示される。作業環境の悪化
、機器の腐食ＩｓＫ対する対策が講じられている場合に
は、これ等の雰囲気ガスに塩素ガス、Ｎ０ＳＮＯ２等を
添加することができる。In the present invention, the spun pitch fibers are infusible in an oxidizing atmosphere such as an oxygen-containing atmosphere at a rate of 0.1 kg/d, 0.
It is carried out under the above pressure, preferably 0.5 to 9/14-0 or above, and heating at 200 to 400°C. In this way, although it varies depending on the thickness of the V4 fibers, the properties of the raw material pitch, etc., the infusibility treatment is usually completed within about one hour, and under optimal conditions, within an extremely short time of about one minute. Examples of the oxygen-containing atmospheric gas employed in the present invention include oxygen, oxygen-enriched air, and air. When measures are taken against deterioration of the working environment and corrosion of equipment IsK, chlorine gas, NOSNO2, etc. can be added to these atmospheric gases.

不融化処理を終えた紡糸ピッチ繊維は、常法に従って、
例えば窒素ガス等の不活性ガスの存在下に２０〜５０°
Ｃ／分程度の速度で９００〜１２００℃程度まで昇温し
、同温度に１〜１０分間程度保持することによシ炭化処
理され、炭素繊維とされる。After the infusibility treatment, the spun pitch fibers are processed according to the conventional method.
For example, 20 to 50° in the presence of an inert gas such as nitrogen gas.
The temperature is raised to about 900 to 1200° C. at a rate of about C/min, and the material is carbonized by holding at the same temperature for about 1 to 10 minutes, thereby producing carbon fibers.

尚、本発明による不融化は、いわゆる活性炭素繊維の不
融化処理にも適用され得ることは言うまでもない。従っ
て、本発明に−う炭素繊維は、活性炭素繊維を包含する
ものである。It goes without saying that the infusibility according to the present invention can also be applied to so-called infusibility treatment of activated carbon fibers. Therefore, the carbon fibers according to the present invention include activated carbon fibers.

日、の　果 本発明によれば、石油系又は石炭系ピッチを原料として
炭素繊維を製造するに際し、不融化処理の時間が大巾に
短縮されるので、炭素繊維製造コストが大きく低減され
る。しかも、得られる炭素繊維の弾性率、引張強度等の
物性は、従来法による製品のそれと同等若しくはそれ以
上の優れたものである。According to the present invention, when producing carbon fiber using petroleum-based or coal-based pitch as a raw material, the time for infusibility treatment is greatly shortened, so the cost of producing carbon fiber is greatly reduced. Moreover, the physical properties of the obtained carbon fibers, such as elastic modulus and tensile strength, are equivalent to or better than those of products produced by conventional methods.

１−凰一　Ｍ 以下実施例を示し、本発明の特徴とするところをよシ一
層明らかに、する。1-凰一M Examples will be shown below to make the features of the present invention more clear.

実施例１〜４ 石炭タールを２５０℃に加温し、Ｆ紙を使用して加１ｌ
ｌＥ濾過を行ない、タール中の固形分を除去した後、ｉ
精製タールを゛減圧蒸留（常圧換算５００°Ｃ）して軽
質分を除去した。得られたピッチの性状は、軟化点（Ｊ
ＩＳ　　Ｋ　　２４２５によるＲｋＢ法）１１４℃、Ｑ
ｌ−０％、Ｂ１−２５．７％であった。Examples 1 to 4 Coal tar was heated to 250°C and added to 1 liter using F paper.
After performing lE filtration to remove the solid content in the tar, i
The purified tar was distilled under reduced pressure (500°C in terms of normal pressure) to remove light components. The properties of the obtained pitch are determined by the softening point (J
RkB method according to IS K 2425) 114℃, Q
1-0%, B1-25.7%.

次いで、上記ピッチ６０重量部に水紫化アントラｔン油
斗０重量部を加え、４５０°Ｃの塩浴中で窒素ガスを吹
き込みつつ１時間熱処理した。かくして、０１−３３．
４％、Ｂ　Ｉ　−８９，２％、メソ相分率−９０％の熱
処理ピッチを得た。Next, 0 parts by weight of water-purified anthraton oil was added to 60 parts by weight of the pitch, and the mixture was heat-treated in a salt bath at 450°C for 1 hour while blowing nitrogen gas. Thus, 01-33.
A heat-treated pitch with a B I of -89.2% and a mesophase fraction of -90% was obtained.

、　　上記で得た熱処理ピッチを常法によル紡糸し、°
Ｃ×５分間保持の条件で炭化処理した。不融化繊維のｍ
素吸着量及び得られた炭素繊維の物性を第２表に示す。, The heat-treated pitch obtained above was spun by a conventional method, and
Carbonization treatment was carried out under the conditions of holding C for 5 minutes. m of infusible fiber
Table 2 shows the elementary adsorption amount and the physical properties of the obtained carbon fiber.

比較例１〜３ 実施例１−４と同様にして熱処理ピッチのｌ［及び紡糸
を行なった後、第１表に示す条件で不融化を行ない、次
いで実施例１と同様にして炭化処理を行なった０結果は
、第２表に示す通シであムｔｊＳＩ表Comparative Examples 1 to 3 After heat-treated pitch was subjected to l [and spinning] in the same manner as in Example 1-4, it was made infusible under the conditions shown in Table 1, and then carbonized in the same manner as in Example 1. The results are shown in Table 2 and are shown in Table 2.

Claims (1)

【特許請求の範囲】[Claims] （１）石油系又は石炭系ピッチを原料とする炭素繊維の
製造方法において、紡糸したピッチ繊維を酸化性雰囲気
中で０．１ｋｇ／ｃｍ＾３・Ｇ以上の加圧下に２００〜
４００℃で不融化処理することを特徴とする炭素繊維の
製造方法。(1) In a method for producing carbon fiber using petroleum-based or coal-based pitch as a raw material, spun pitch fibers are heated under a pressure of 0.1 kg/cm^3 G or more in an oxidizing atmosphere at 200 to
A method for producing carbon fiber, characterized by carrying out an infusibility treatment at 400°C.