JPH01282314A - Production of pitch-based carbon fiber - Google Patents
Production of pitch-based carbon fiberInfo
- Publication number
- JPH01282314A JPH01282314A JP11400288A JP11400288A JPH01282314A JP H01282314 A JPH01282314 A JP H01282314A JP 11400288 A JP11400288 A JP 11400288A JP 11400288 A JP11400288 A JP 11400288A JP H01282314 A JPH01282314 A JP H01282314A
- Authority
- JP
- Japan
- Prior art keywords
- fiber
- yarn
- pitch
- precarbonization
- carbonization
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229920000049 Carbon (fiber) Polymers 0.000 title claims description 9
- 239000004917 carbon fiber Substances 0.000 title claims description 9
- 238000004519 manufacturing process Methods 0.000 title claims description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 title description 8
- 238000001816 cooling Methods 0.000 claims abstract description 14
- 238000010000 carbonizing Methods 0.000 claims description 4
- 238000003763 carbonization Methods 0.000 abstract description 16
- 238000009656 pre-carbonization Methods 0.000 abstract description 15
- 238000000034 method Methods 0.000 abstract description 13
- 239000000835 fiber Substances 0.000 abstract description 12
- 239000002994 raw material Substances 0.000 abstract description 5
- 238000009987 spinning Methods 0.000 abstract description 4
- 239000012212 insulator Substances 0.000 abstract 1
- 239000011295 pitch Substances 0.000 description 11
- 230000000704 physical effect Effects 0.000 description 9
- 238000005087 graphitization Methods 0.000 description 7
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- 239000011300 coal pitch Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 238000007254 oxidation reaction Methods 0.000 description 3
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000002074 melt spinning Methods 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010894 electron beam technology Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000002783 friction material Substances 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 239000011301 petroleum pitch Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 239000003566 sealing material Substances 0.000 description 1
- 238000010583 slow cooling Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
（産業上の利用分野）
本発明は、断熱材、シール材、電気材料部品、構造部材
、摩擦材料、炭素電極などに使用されているピッチ系炭
素繊維の製造法に関する。Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing pitch-based carbon fibers used in heat insulating materials, sealing materials, electrical material parts, structural members, friction materials, carbon electrodes, etc. .
（従来の技術）
ピッチ系炭素繊維は、素原料が安い、炭化収率が高い、
原料の物理・化学構造に起因して高弾性率が得やすいな
どの特徴があり、注目を集めている。(Conventional technology) Pitch-based carbon fiber has low raw materials, high carbonization yield,
Due to the physical and chemical structure of the raw material, it has characteristics such as the ability to easily obtain a high elastic modulus, and is attracting attention.
一般に高強度、高弾性率ピッチ系炭素繊維製造プロセス
は、溶融紡糸、不融化、炭化、黒鉛化という工程を経て
作られるが、不融化終了時の糸の物性は、強度が６に９
／ｍｍ２、伸度が２％程度と極めて弱くハンドリング性
に劣っている。Generally, high strength, high modulus pitch carbon fiber manufacturing process is made through the steps of melt spinning, infusibility, carbonization, and graphitization, but the physical properties of the yarn after infusibility is 6 to 9.
/mm2, the elongation is extremely weak at about 2%, and the handling property is poor.
一方、炭化以降の処理は、その操作性及び経済性を考慮
したとき、連続糸として扱うことが好ましく、そのため
実際のプロセスでは、炭化炉に糸を投入する前に、糸を
不活性雰囲気中、数百度で焼成するいわゆる前炭化処理
を施すことが行われている。特開昭６０−２１９１１に
は、紡糸したピッチ糸をボビンに巻きとるかネット上に
堆積させたまま、不融化後ａｏｏ ’ｃ〜６５０°Ｃの
範囲で前炭化処理し、次いで糸をたちあげて、連続系で
炭化する方法が示されている。かかる方法によれば、前
炭化領域では、温度が上昇するにつれて強度が序々に増
加する一方、伸度は５００°Ｃ〜６００ °Ｃで５〜８
％の極大値をもつという特異な挙動を示し、この物性の
糸は、結節も容易で、速い送出しを行うことが可能であ
るということが示されている。On the other hand, in the treatment after carbonization, it is preferable to treat the yarn as a continuous yarn when considering its operability and economical efficiency. Therefore, in the actual process, the yarn is treated in an inert atmosphere before being introduced into the carbonization furnace. A so-called pre-carbonization treatment, which involves firing at several hundred degrees, is performed. Japanese Patent Application Laid-Open No. 60-21911 discloses that the spun pitch yarn is wound around a bobbin or deposited on a net, and after being infusible, it is pre-carbonized at a temperature of 650°C to 650°C, and then the yarn is taken up. A continuous carbonization method has been proposed. According to this method, in the pre-carbonized region, the strength gradually increases as the temperature increases, while the elongation is 5 to 8 at 500 °C to 600 °C.
It has been shown that a yarn with this physical property can be easily knotted and can be delivered quickly.
しかしながら、上述の方法においては、前炭化終了後の
処理法についての記載がなく、往々にして前炭化で１ｑ
られた高伸度がその冷却時に失われてしまうという欠点
が起っている。とくにボビン、及びネット上への積層状
態で処理し、系全体の熱容量が大きく、冷却速度が遅い
ときには、上述の問題点が無視できなくなっている。そ
のため、次の炭化、黒鉛化において、例えば張力を付与
しながら焼成をする場合など、その張力に耐えず、糸切
れにつながるという欠点を有していた。However, in the above-mentioned method, there is no description of the treatment method after the completion of pre-carbonization, and in many cases, 1q
The disadvantage is that the high elongation obtained is lost during cooling. In particular, when processing is performed in a stacked state on a bobbin or net, the heat capacity of the entire system is large, and the cooling rate is slow, the above-mentioned problems cannot be ignored. Therefore, in the subsequent carbonization and graphitization, for example, when firing is performed while applying tension, the fiber cannot withstand the tension, resulting in thread breakage.
（発明が解決しようとする課題）
本発明の目的はかかる課題を解決し、炭化、黒鉛化工程
を連続系でしかも安定に行い得るだけの十分なハンドリ
ング性を有す高伸度炭素繊維前駆体を提供することにお
る。(Problems to be Solved by the Invention) The purpose of the present invention is to solve the above-mentioned problems, and to provide a high elongation carbon fiber precursor that has sufficient handling properties to perform carbonization and graphitization processes continuously and stably. We are here to provide you with the following.
（課題を解決するための手段）
上記目的を達成するために本発明は、次の構成を有する
。(Means for Solving the Problems) In order to achieve the above object, the present invention has the following configuration.
すなわち本発明は、不融化糸を前炭化処理するにあたり
、前炭化の最高処理温度に到達後、ただちに８°Ｃ／ｍ
ｉ ｎ以上の速度で冷却することを特徴とするピッチ
系炭素繊維の製造法に関する。That is, in the present invention, when pre-carbonizing the infusible yarn, the temperature is increased to 8°C/m immediately after reaching the maximum pre-carbonizing temperature.
The present invention relates to a method for producing pitch-based carbon fiber, which is characterized by cooling at a rate of at least i n.
以下本尭明を詳細に説明する。Motoyaaki will be explained in detail below.
本発明における不融化糸は、公知の方法で得ることがで
きる。すなわち、原料ピッチを紡糸した後、不融化する
ことで得られる。The infusible yarn in the present invention can be obtained by a known method. That is, it is obtained by spinning raw material pitch and then making it infusible.
本発明におけるピッチ系炭素繊維原料としては、石油系
ピッチ、石炭系ピッチのどちらでもかまわない。また、
光学的異方性の発達したピッチ、等方性ピッチのどちら
でもよいが、高強度の物性を有し、連続繊維として用途
のある前者のほうが本発明の特徴を最大限生かしうる。The pitch-based carbon fiber raw material in the present invention may be either petroleum-based pitch or coal-based pitch. Also,
Either a pitch with developed optical anisotropy or an isotropic pitch may be used, but the former, which has high strength physical properties and is useful as a continuous fiber, can make the most of the features of the present invention.
本発明における紡糸は、通常の溶融紡糸をとり得る。巻
きとりは、脆弱な糸に対し負荷を与えなければ特に規定
はされず、ボビン形式、ネット積層方式などが可能ある
。The spinning in the present invention can be carried out by ordinary melt spinning. Winding is not particularly stipulated as long as no load is applied to the fragile thread, and bobbin style, net layered style, etc. are possible.
本発明における不融化処理は、空気酸化が代表的でおる
が、その他、亜ｆＩ酸ガス、オゾンなどの気相酸化や、
硝酸、過酸化水素水などを用いた液相酸化によっても可
能であり、溶融性のピッチを不融性にしさえすればよく
、場合によっては、電子線架橋など物理的手段でも差支
えない。The infusibility treatment in the present invention is typically air oxidation, but other methods include gas phase oxidation using fI acid gas, ozone, etc.
It is also possible to perform liquid phase oxidation using nitric acid, hydrogen peroxide, etc., as long as the meltable pitch is made infusible, and in some cases, physical means such as electron beam crosslinking may also be used.
ｊｑられた不融化糸は、次いで前炭化処理が施される。The jqed infusible yarn is then subjected to a pre-carbonization treatment.
前炭化は、不活性雰囲気中、数百度、例えば４００ ’
Ｃ〜８００ ’Ｃで行いうる。温度が高ければ高いほど
強度は上昇するが、伸度は５００℃〜６５０℃で極大値
を持つため、炭化以降の処理条件などにより両者のかね
あいで決定されうる。すなわち、炭化時に、張力をかけ
たい場合などには、高伸度を得ることに重きを置くべき
である。前炭化における昇温速度は、速すぎると単糸間
で融着を起こすため、２０°Ｃ／ｍｉｎ以下が好ましい
。一方、昇温速度が過度に遅すぎることは、プロセス上
何等得策ではなく、より好ましくは５°Ｃ／１Ｉｌｉｎ
〜１５℃／ｍｉｎである。Pre-carbonization is carried out at several hundred degrees, e.g. 400', in an inert atmosphere.
It can be carried out at temperatures between C and 800'C. The higher the temperature, the higher the strength, but the elongation has its maximum value at 500°C to 650°C, so it can be determined by the balance between the two depending on the processing conditions after carbonization. That is, when it is desired to apply tension during carbonization, emphasis should be placed on obtaining high elongation. The temperature increase rate during pre-carbonization is preferably 20°C/min or less because if it is too fast, fusion will occur between the single filaments. On the other hand, an excessively slow temperature increase rate is not a good idea in terms of the process, and more preferably 5°C/1Ilin.
~15°C/min.
前炭化処理における糸形態は、糸に過度の負荷がかから
なければよく、ボビン形態、ネット上に堆積した状態な
ど、不融化処理と同じ形態でされうる。The yarn form in the pre-carbonization treatment may be the same as in the infusible treatment, such as a bobbin form or a state deposited on a net, as long as an excessive load is not applied to the yarn.
本発明における最大の特徴は、前記前炭化温度に到達後
、直ちに８°Ｃ／ｍｉｎ以上の速度で冷却することにあ
る。前炭化温度に到達後、その温度で糸を保持したり、
徐冷した場合には、強度はそれほど上昇しない一方で伸
度が低下してしまい、せっかく（ｑられたハンドリング
可能な物性が失われてしまうからである。本発明でいう
徐冷とは、８°Ｃ／ｍｉｎ以下の速度での冷却を指す。The most important feature of the present invention is that immediately after reaching the pre-carbonization temperature, cooling is performed at a rate of 8°C/min or more. After reaching the pre-carbonization temperature, hold the yarn at that temperature,
In the case of slow cooling, the strength does not increase so much, but the elongation decreases, and the physical properties that are able to be handled are lost. Refers to cooling at a rate of less than °C/min.
８℃／ｍｉｎ以上の速度で冷却する方法は特に規定され
ない。系全体の熱容量が小さい場合には、ヒーターを切
るだ【ブの自然冷却で達成され得る。また、系の熱容量
が大きい場合には、強制的に冷却することが必要となり
、それは、不活性ガスを系内へ吹込む、掌温なと低温の
不活性雰囲気中に糸を移動させる、炉全体をファンを用
いて冷やす、などにより達成される。A method of cooling at a rate of 8° C./min or higher is not particularly specified. If the heat capacity of the entire system is small, turning off the heater can be achieved by natural cooling. In addition, if the heat capacity of the system is large, forced cooling may be necessary, such as blowing an inert gas into the system, moving the yarn into an inert atmosphere at a low temperature, or using a furnace. This is achieved by cooling the entire unit using a fan.
かかる方式で得られた前炭化糸の物性は、前炭化温度に
到達した瞬間に得られた高伸度を維持し、ハンドリング
性も高いままである。したがって、次いで炭化、黒鉛化
を連続方式でより安定に、さらには、張力付与下での安
定炭化、黒鉛化を可能にするものである。The physical properties of the pre-carbonized yarn obtained by this method maintain the high elongation obtained at the moment the pre-carbonization temperature is reached, and the handling properties remain high. Therefore, it is possible to carry out carbonization and graphitization more stably in a continuous manner, and further, to perform stable carbonization and graphitization under tension.
以下、本発明を実施例を用いて更に詳細に説明する。Hereinafter, the present invention will be explained in more detail using Examples.
（実施例）
実施例１
石炭系ピッチ（光学的異方性９０％）をホール数１００
の紡糸機で溶融紡糸し、ネット上へ積層した。(Example) Example 1 Coal-based pitch (90% optical anisotropy) with 100 holes
The fibers were melt-spun using a spinning machine and laminated onto a net.
糸に負荷を与えないようネットごとオーブン中へ移し、
空気雰囲気下で不融化処理を行った。不融化条件は、０
．５℃／ｍｉｎで３００ ’Ｃまで昇温し、１０分保持
した後、自然冷却するものであった。得られた不融化糸
の物性は、強度６ｋｑ／ｍｍ２、伸度１，５％と弱く、
ローラーでたちあげることはできなかった。ついで１ｑ
られた不融化糸をネット上に積層したまま、不活性雰囲
気中、昇温速度１０℃／ｍｉｎで６００°Ｃまで昇温し
、前炭化処理を行った。６００ ’Ｃに到達後、直ちに
ヒーターを切り、炉内に室温の窒素を吹込み、系全体を
強制冷却させた。このときの冷却速度は、１５℃／ｍｉ
ｎであった。得られた前炭化糸の物性は、強度２８ ｋ
ｇ ７ｒｒｍ２、伸度６．６％であり、ローラーで送出
し、巻きとりができるだけの十分なハンドリング性を有
していた。しだがって、次工程の炭化を、安定した連続
系で行うことが可能であった。Transfer the net to the oven so as not to put stress on the threads.
Infusibility treatment was performed in an air atmosphere. The infusibility conditions are 0
．． The temperature was raised to 300'C at a rate of 5°C/min, held for 10 minutes, and then naturally cooled. The physical properties of the obtained infusible yarn were weak, with a strength of 6 kq/mm2 and an elongation of 1.5%.
I couldn't lift it up with rollers. Then 1q
While the infusible yarns were stacked on the net, the temperature was raised to 600°C at a temperature increase rate of 10°C/min in an inert atmosphere to perform a pre-carbonization treatment. Immediately after reaching 600'C, the heater was turned off and nitrogen at room temperature was blown into the furnace to forcefully cool the entire system. The cooling rate at this time was 15°C/mi
It was n. The physical properties of the obtained pre-carbonized yarn are as follows: strength 28k
g 7rrm2 and elongation 6.6%, and had sufficient handling properties to be able to be sent out with a roller and wound up. Therefore, it was possible to carry out the next step, carbonization, in a stable continuous system.
実施例２
実施例１と同様、光学的異方性９０％の石炭系ピッチを
溶融紡糸し、糸を耐熱性のボビンに８００ ｍ／ｍｉｎ
の速度で巻きとった。ついでボビンごと実施例１のごと
く不融化を行ったところ、得られた不融化糸は糸物性が
弱く、ボビンから解じょしようとすると、その張力に耐
えず、糸切れを生じた。Example 2 As in Example 1, coal-based pitch with an optical anisotropy of 90% was melt-spun, and the yarn was spun on a heat-resistant bobbin at 800 m/min.
It was wound at a speed of . When the bobbin was then infusible as in Example 1, the resulting infusible yarn had poor thread properties, and when it was attempted to be unraveled from the bobbin, it could not withstand the tension and the yarn broke.
この不融化糸をボビンごと実施例１と同条件で前炭化し
、終了接直ちに窒素を吹込み、強制冷却した。このとき
の冷却速度は、１５°Ｑ／ｍｉｎであった。This infusible yarn was pre-carbonized together with the bobbin under the same conditions as in Example 1, and immediately after the welding was completed, nitrogen was blown into the yarn and forcedly cooled. The cooling rate at this time was 15°Q/min.
１ｑられた前炭化糸の物性は、強度３０ｋｌ ／ ｍｍ
２ 、伸度７．０％であり、ボビンから解じょしても
糸切れしないだ【プのハンドリング性を有していた。し
たがって、次工程の炭化を、安定した連続系で行うこと
が可能であった。The physical properties of the 1q pre-carbonized yarn are strength 30kl/mm
2. The elongation was 7.0%, and the thread did not break even when unwound from the bobbin. Therefore, it was possible to carry out the next step of carbonization in a stable continuous system.
比較例
実施例１において得られた前炭化糸を強制冷却せず、自
然冷却としたところ、その冷却速度は４°Ｃ／ｍｉｎで
あった。この前炭化糸の物性を測定したところ、強度３
１ｋＣＪ／ｍｍ２ 、伸度３．２％でおり、伸度が実施
例１に比べて低下しているのが認められた。引続いて、
この糸をローラーを用いた連続炉で炭化・黒鉛化したと
ころ、多数のケバが認められた上に、糸切れも頻繁に発
生した。Comparative Example When the pre-carbonized yarn obtained in Example 1 was naturally cooled without being forced to cool, the cooling rate was 4°C/min. When the physical properties of the carbonized yarn were previously measured, the strength was 3.
It was found that the elongation was 1 kCJ/mm2 and the elongation was 3.2%, which was lower than that of Example 1. Subsequently,
When this yarn was carbonized and graphitized in a continuous furnace using rollers, not only many fluffs were observed, but also yarn breakage occurred frequently.
（発明の効果）
本発明は、炭化、黒鉛化工程を連続系でしかも安定に行
い得るだけの十分なハンドリング性を有する高伸度ピッ
チ系炭素繊維が提供できる。本発明により、緊張状態で
の炭化、黒鉛化も可能となる。(Effects of the Invention) The present invention can provide a high elongation pitch-based carbon fiber that has sufficient handling properties to carry out carbonization and graphitization processes continuously and stably. The present invention also enables carbonization and graphitization under tension.
Claims (1)
高処理温度に到達後、ただちに８℃／ｍｉｎ以上の速度
で冷却することを特徴とするピッチ系炭素繊維の製造法
。(1) A method for producing pitch-based carbon fibers, which comprises pre-carbonizing the infusible yarn and immediately cooling it at a rate of 8° C./min or more after reaching the maximum pre-carbonizing temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11400288A JPH01282314A (en) | 1988-05-10 | 1988-05-10 | Production of pitch-based carbon fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11400288A JPH01282314A (en) | 1988-05-10 | 1988-05-10 | Production of pitch-based carbon fiber |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01282314A true JPH01282314A (en) | 1989-11-14 |
Family
ID=14626601
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11400288A Pending JPH01282314A (en) | 1988-05-10 | 1988-05-10 | Production of pitch-based carbon fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01282314A (en) |
-
1988
- 1988-05-10 JP JP11400288A patent/JPH01282314A/en active Pending
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