JPH01124629A - Graphite fiber having high compressive strength - Google Patents
Graphite fiber having high compressive strengthInfo
- Publication number
- JPH01124629A JPH01124629A JP28153687A JP28153687A JPH01124629A JP H01124629 A JPH01124629 A JP H01124629A JP 28153687 A JP28153687 A JP 28153687A JP 28153687 A JP28153687 A JP 28153687A JP H01124629 A JPH01124629 A JP H01124629A
- Authority
- JP
- Japan
- Prior art keywords
- modulus
- compressive strength
- yarn
- graphite
- fiber
- 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
- 239000000835 fiber Substances 0.000 title claims abstract description 56
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 title claims abstract description 40
- 229910002804 graphite Inorganic materials 0.000 title claims abstract description 33
- 239000010439 graphite Substances 0.000 title claims abstract description 33
- 238000005087 graphitization Methods 0.000 abstract description 14
- 239000002131 composite material Substances 0.000 abstract description 12
- 239000000463 material Substances 0.000 abstract description 7
- 238000003763 carbonization Methods 0.000 abstract description 6
- 238000007334 copolymerization reaction Methods 0.000 abstract description 6
- 239000011159 matrix material Substances 0.000 abstract description 5
- 229920003023 plastic Polymers 0.000 abstract description 5
- 239000004033 plastic Substances 0.000 abstract description 5
- NLHHRLWOUZZQLW-UHFFFAOYSA-N Acrylonitrile Chemical compound C=CC#N NLHHRLWOUZZQLW-UHFFFAOYSA-N 0.000 abstract description 4
- 229920000642 polymer Polymers 0.000 abstract description 4
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 abstract 1
- 239000010931 gold Substances 0.000 abstract 1
- 229910052737 gold Inorganic materials 0.000 abstract 1
- 229920000049 Carbon (fiber) Polymers 0.000 description 19
- 239000004917 carbon fiber Substances 0.000 description 19
- 238000000034 method Methods 0.000 description 17
- 238000010304 firing Methods 0.000 description 12
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 description 10
- 229910052740 iodine Inorganic materials 0.000 description 10
- 239000011630 iodine Substances 0.000 description 10
- 229920002239 polyacrylonitrile Polymers 0.000 description 10
- 230000007423 decrease Effects 0.000 description 9
- 239000013078 crystal Substances 0.000 description 7
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 5
- 238000001179 sorption measurement Methods 0.000 description 5
- 238000009987 spinning Methods 0.000 description 5
- 239000012298 atmosphere Substances 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000003921 oil Substances 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 238000002441 X-ray diffraction Methods 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000015271 coagulation Effects 0.000 description 3
- 238000005345 coagulation Methods 0.000 description 3
- 239000011521 glass Substances 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- NLKNQRATVPKPDG-UHFFFAOYSA-M potassium iodide Chemical compound [K+].[I-] NLKNQRATVPKPDG-UHFFFAOYSA-M 0.000 description 3
- 239000000243 solution Substances 0.000 description 3
- 239000007858 starting material Substances 0.000 description 3
- RNFJDJUURJAICM-UHFFFAOYSA-N 2,2,4,4,6,6-hexaphenoxy-1,3,5-triaza-2$l^{5},4$l^{5},6$l^{5}-triphosphacyclohexa-1,3,5-triene Chemical compound N=1P(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP(OC=2C=CC=CC=2)(OC=2C=CC=CC=2)=NP=1(OC=1C=CC=CC=1)OC1=CC=CC=C1 RNFJDJUURJAICM-UHFFFAOYSA-N 0.000 description 2
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000004744 fabric Substances 0.000 description 2
- 239000003063 flame retardant Substances 0.000 description 2
- -1 foreign matter Substances 0.000 description 2
- 230000005484 gravity Effects 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- SQGYOTSLMSWVJD-UHFFFAOYSA-N silver(1+) nitrate Chemical compound [Ag+].[O-]N(=O)=O SQGYOTSLMSWVJD-UHFFFAOYSA-N 0.000 description 2
- 238000005303 weighing Methods 0.000 description 2
- 238000002166 wet spinning Methods 0.000 description 2
- HFZWRUODUSTPEG-UHFFFAOYSA-N 2,4-dichlorophenol Chemical compound OC1=CC=C(Cl)C=C1Cl HFZWRUODUSTPEG-UHFFFAOYSA-N 0.000 description 1
- 229920002972 Acrylic fiber Polymers 0.000 description 1
- CERQOIWHTDAKMF-UHFFFAOYSA-N Methacrylic acid Chemical compound CC(=C)C(O)=O CERQOIWHTDAKMF-UHFFFAOYSA-N 0.000 description 1
- 230000001133 acceleration Effects 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- BFNBIHQBYMNNAN-UHFFFAOYSA-N ammonium sulfate Chemical compound N.N.OS(O)(=O)=O BFNBIHQBYMNNAN-UHFFFAOYSA-N 0.000 description 1
- 229910052921 ammonium sulfate Inorganic materials 0.000 description 1
- 235000011130 ammonium sulphate Nutrition 0.000 description 1
- 238000005452 bending Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 125000000118 dimethyl group Chemical group [H]C([H])([H])* 0.000 description 1
- 238000000578 dry spinning Methods 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 239000003733 fiber-reinforced composite Substances 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 125000002560 nitrile group Chemical group 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 239000012466 permeate Substances 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 238000003918 potentiometric titration Methods 0.000 description 1
- 239000002243 precursor Substances 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000007363 ring formation reaction Methods 0.000 description 1
- 229910001961 silver nitrate Inorganic materials 0.000 description 1
- 239000007790 solid phase Substances 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 235000021419 vinegar Nutrition 0.000 description 1
- 239000000052 vinegar Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は高い圧縮強度を有する黒鉛繊維、さらに詳しく
はプラスチックをマトリックスとした複合材料の性能向
上に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to improving the performance of graphite fibers having high compressive strength, and more particularly to composite materials having a plastic matrix.
［従来の技術］
炭素繊維は、比強度や比弾性率が金属材料などに比べ高
いので、近年、ゴルフシャフト、釣竿などのスポーツ・
レジャー分野や宇宙航空用途を主体に、軽量構造材とし
て大量に使用されるに至っている。その需要の拡大に伴
って、品質の一層の向上が望まれており、最近、引張強
度の改善には大きな進歩が見られているが、圧縮強度が
同時に向上せず、引張・圧縮のバランスが不均衡になる
という問題が生じている。[Prior art] Carbon fiber has higher specific strength and specific modulus than metal materials, so it has recently been used for sports equipment such as golf shafts and fishing rods.
It has come to be used in large quantities as a lightweight structural material, mainly in the leisure field and aerospace applications. With the increasing demand, further improvement in quality is desired, and although great progress has recently been made in improving tensile strength, the compressive strength has not improved at the same time, and the balance between tension and compression is poor. There is a problem of imbalance.
特に弾性率の高い黒鉛繊維にあっては、その剛性を有効
に活用し、−層の軽量化効果を実現するためにはより薄
肉の構造材とすることが一般的であるが、このような場
合には圧縮強度が制約条件となることが多い。Especially for graphite fibers, which have a high modulus of elasticity, in order to effectively utilize their stiffness and achieve the effect of reducing the weight of the layers, it is common to use thinner structural materials. In many cases, compressive strength is a constraint.
ところで、炭素繊維は良く知られているように。By the way, carbon fiber is well known.
セルロース、ポリアクリロニトリル、ピッチなどの有機
繊維を不活性ガス中で高温で焼成することによって得ら
れる。一般には最終の焼成温度は１０００℃以上であり
、特に黒鉛繊維においては２０００℃を越えることがあ
る。It is obtained by firing organic fibers such as cellulose, polyacrylonitrile, and pitch in an inert gas at high temperatures. Generally, the final firing temperature is 1000°C or higher, and in particular for graphite fibers, it may exceed 2000°C.
また、特にポリアクリロニトリルを出発原料とする場合
、原糸製造段階では高い延伸倍率を適用し、高度に配向
した構造を与え、かつ、これを緊張下に保って焼成する
ことが高強度、高弾性率の炭素繊維を得るための重要な
要件であることが広く知られている。炭素はその結晶構
造として、ダイヤモンド構造とグラフ１イト構造の二種
類をとり得るが、炭素繊維は一般に網面の積層した構造
よりなるグラフフィト構造を示す。このグラフフィト構
造は一般的な金属の結晶構造などと比較すると極めて異
方性の強いものでおり、網面を繊維軸方向に選択的に配
向させることにより、繊維軸方向の力学特性を高めてい
る。In addition, especially when polyacrylonitrile is used as a starting material, it is necessary to apply a high stretching ratio at the yarn manufacturing stage to give it a highly oriented structure, and to maintain this under tension while firing to achieve high strength and high elasticity. It is widely known that this is an important requirement for obtaining carbon fibers with high carbon fibers. Carbon can have two types of crystal structure: a diamond structure and a graphite structure, but carbon fibers generally exhibit a graphite structure consisting of a layered network structure. This graphite structure has extremely strong anisotropy compared to the crystal structure of general metals, and by selectively orienting the mesh plane in the fiber axis direction, the mechanical properties in the fiber axis direction are improved. There is.
高い引張強度を実現するためには、これら結晶構造の完
全性を高めることも重要であるが、一方。In order to achieve high tensile strength, it is also important to improve the integrity of these crystal structures.
単繊維間の接着や、異物、不純物１機械的損傷などの表
層欠陥を排除することが極めて重要であり、改めて例示
するまでもなく１強度向上に関して数多くの改良技術が
提案されている。It is extremely important to eliminate surface defects such as adhesion between single fibers, foreign matter, impurities, mechanical damage, etc., and many improvement techniques have been proposed to improve strength, without needing to exemplify them.
しかし、炭素繊維の圧縮強度に関する改善については、
これまで殆ど検討、提案された例を見ることができない
。僅かに特開昭５９−１１８２０３号公報中に、単糸デ
ニールを太くすると圧縮強度が改善されるとの記載が見
られる程度でおる。However, regarding improvements in the compressive strength of carbon fibers,
I can't see any examples that have been considered or proposed so far. There is only a statement in JP-A-59-118203 that the compressive strength is improved by increasing the single yarn denier.
確かに、繊維強化複合材料において、それを構成する繊
維の太さが圧縮強度に作用することは考えられるが、炭
素！ｉｉ、９Ｍのような脆性材料にあっては、繊維径が
太くなると２反って欠陥を内在する確率が高くなり、高
強度を実現することが困難となる。また炭素繊維の焼成
は同相における熱分解反応であるから、繊維径が太いも
のは均一に焼成することの困難さが一層増すばかりでな
く、反応速度を必然的に低くする必要があることから経
済的にも不利となる。従って、これまでは本質的な解決
を繊維に求めようとするよりも、より剛性の高いマトリ
ックスに期待することが多いこともめって、炭素繊維側
から圧縮強度を向上させようとする試みは殆どなされて
いなかった。It is certainly possible that the thickness of the fibers that make up fiber-reinforced composite materials affects the compressive strength, but carbon! ii. In a brittle material such as 9M, as the fiber diameter increases, the probability of double warping and defects increases, making it difficult to achieve high strength. Furthermore, since firing carbon fibers is a thermal decomposition reaction in the same phase, it is not only more difficult to uniformly fire fibers with large diameters, but it is also economical because the reaction rate must necessarily be lowered. It is also disadvantageous. Therefore, until now, rather than seeking essential solutions in fibers, expectations have often been placed on a matrix with higher rigidity, and there have been few attempts to improve compressive strength from the carbon fiber side. It had not been done.
［発明が解決しようとする問題点コ
本発明者らは、上記従来技術に対し、炭素１１ＡＭの内
部構造に着目し、これを適正化することにより、複合材
料として高い圧縮強度を実現することに関して鋭意検討
し、本発明に至ったものである。[Problems to be Solved by the Invention] In contrast to the above-mentioned conventional technology, the present inventors focused on the internal structure of carbon 11AM, and by optimizing it, realized high compressive strength as a composite material. The present invention was developed after extensive research.
特にその対象としては弾性率が５５ ｔ／ｓ２以上の超
高弾性率黒鉛繊維でおる。その理由は例えばポリアクリ
ロニトリル系炭素繊維においては、弾性率が高くなるに
従い複合材料の圧縮強度が極端に低下する傾向が見られ
るためである。また既述したように、弾性率の高い炭素
繊維は実用上、より薄肉構造材としてその特徴を発揮す
ることが期待されているが、圧縮強度が用途拡大の障害
となっている場合が多いためである。従って、本発明の
目的は炭素繊維の弾性率を低下させることなく、圧縮強
度を向上させ、複合材料における設計上の自由度を更に
拡げることを可能とする超高弾性率黒鉛繊維を提供する
にある。In particular, ultra-high modulus graphite fibers with an elastic modulus of 55 t/s2 or more are suitable for this purpose. This is because, for example, in polyacrylonitrile carbon fibers, as the elastic modulus increases, the compressive strength of the composite material tends to decrease extremely. In addition, as mentioned above, carbon fiber with a high modulus of elasticity is expected to exhibit its characteristics as a thinner structural material in practical use, but its compressive strength is often an obstacle to expanding its use. It is. Therefore, an object of the present invention is to provide ultra-high modulus graphite fibers that can improve the compressive strength without reducing the modulus of elasticity of carbon fibers and further expand the degree of freedom in designing composite materials. be.
［問題点を解決するための手段］
本発明の上記目的は、ネジリ弾性率および圧縮弾性率が
下記式を′ｆ４足する黒鉛繊維によって達成することが
できる。[Means for Solving the Problems] The above object of the present invention can be achieved by using graphite fibers whose torsional elastic modulus and compressive elastic modulus satisfy the following formula plus 'f4.
Ｇ「上２゜１５−０．０１５Ｅｊ
Ｅｆ≧５５
ただし、Ｇｆ：ネジリ弾性率（ｔ／＃２）Ｅｆ：引張弾
性率（ｔ／ｍ” ）
すなわち、本発明者らの検討は如何にして弾性率を高く
保ち、かつ圧縮強度の低下を防止するかにあった。炭素
繊維を用いた複合材料の圧縮強度が低くなる原因は、繊
維の構造の異方性にあるとの認識に立ち、その異方性を
制御することを検討した。G"Upper 2゜15-0.015Ej Ef≧55 However, Gf: Torsional modulus of elasticity (t/#2) Ef: Tensile modulus of elasticity (t/m") In other words, the present inventors' study is how to determine the elasticity The aim was to maintain a high ratio and prevent a decrease in compressive strength. Recognizing that the cause of the low compressive strength of composite materials using carbon fibers is the anisotropy of the fiber structure, we investigated ways to control this anisotropy.
ピッチ系炭素繊維はポリアクリロニトリル系炭素繊維と
比較すると、その異方性は極めて大きく、同一弾性率に
おいてネジリ弾性率は低く、圧縮強度は極めて低いこと
が良く知られている。ピッチ系に比べて優れた圧縮強度
を有するポリアクリロニトリル系の炭素繊維においても
、その引張弾性率を高くしていくと、異方性が大きくな
る。その結果、ネジリ弾性率が低下すると共に、圧縮強
度も低下し、特に引張弾性率が５０ｔ／＃２以上の超高
弾性率の領域では黒鉛化最高処理温度の二千数百度以上
という高温処理のため、異方性の増大と圧縮強度の低下
が顕著に現われる。この黒鉛ｍ維の異方性は繊維を構成
する黒鉛結晶の性状［サイズ（Ｌｏ、Ｌａ）コおよび面
間隔（ｄ ００２） 、割合（結晶化度）配向およびボ
イドによって決まる。It is well known that pitch-based carbon fibers have extremely high anisotropy when compared to polyacrylonitrile-based carbon fibers, have low torsional modulus, and extremely low compressive strength at the same modulus of elasticity. Even in polyacrylonitrile-based carbon fibers which have superior compressive strength compared to pitch-based carbon fibers, anisotropy increases as the tensile modulus increases. As a result, the torsional modulus of elasticity decreases, and the compressive strength also decreases, especially in the ultra-high modulus region with a tensile modulus of 50t/#2 or higher, which is difficult to treat at high temperatures of over 2,000 degrees Celsius, which is the maximum graphitization treatment temperature. Therefore, an increase in anisotropy and a decrease in compressive strength are noticeable. The anisotropy of the graphite m-fibers is determined by the properties of the graphite crystals constituting the fibers [size (Lo, La) and interplanar spacing (d 002), ratio (crystallinity) orientation, and voids.
即ち、より完全な黒鉛結晶に近づけば近づくほど、また
結晶化度が高くなればなるほど、更に配向度が高くなれ
ばなるほど、更にまたボイドが少なければ少ないはど引
張弾性率は高くなり、一方、異方性が大きくなって、ネ
ジリ弾性率は低くなる。That is, the closer to a perfect graphite crystal, the higher the degree of crystallinity, the higher the degree of orientation, and the fewer voids, the higher the tensile modulus. As the anisotropy increases, the torsional modulus decreases.
この引張弾性率発現のために必要最小限の異方性に制御
する、即ち２例えば引張弾性率が５５ ｔ／ｍｍ２の場
合、ネジリ弾性率を１．３３℃／＃ｒ１２以上とするこ
とで、本発明の目的とする極めて優れた圧縮強度を有す
る黒鉛繊維が得られるのである。In order to express this tensile elastic modulus, the anisotropy is controlled to the minimum necessary, that is, 2. For example, when the tensile elastic modulus is 55 t/mm2, the torsional elastic modulus is set to 1.33°C/#r12 or more, Graphite fibers having extremely excellent compressive strength, which is the object of the present invention, can be obtained.
本発明におけるネジリ弾性率および引張弾性率は次の方
法に従った。The torsional modulus and tensile modulus in the present invention were determined according to the following method.
ネジリ弾性率の測定；
第１図に示すように、単繊＃１１（長ざ約１５ ｃｍ）
の一端をガラス毛細管２ （重さ約０．５ｔｊ）中に挿
入して瞬間接着剤で接着し、他端はクツション紙を介し
てクリップ３で固定して単繊ｌｆｆ１ｌをつり下げる。Measurement of torsional modulus; As shown in Figure 1, single fiber #11 (length approximately 15 cm)
One end of the glass capillary tube 2 (weighing about 0.5 tj) is inserted into the glass capillary tube 2 (weighing about 0.5 tj) and glued with instant adhesive, and the other end is fixed with a clip 3 through cushion paper to suspend the single fiber lff1l.
そして毛細管２を回転させて繊維にねじりを与え、この
ときの振動周期（丁）を測定する。Then, the capillary tube 2 is rotated to give twist to the fiber, and the vibration period (di) at this time is measured.
繊維のネジリ弾性率Ｇｆは次式により算出する。The torsional modulus Gf of the fiber is calculated using the following formula.
１２８πｆＩＩ
ここで、ｐ：繊維の長さ
Ｉ：ねじりモーメント
Ｍ：毛細管重量
り二毛細管径
ｄ：繊維径
Ｊ：重力加速度
ただし、繊維断面は厳密には円形でないが、ここでは糸
目付けＷ、単糸数Ｎ、比重
ρを用いて
として繊維径を求めた。128πfII where, p: Fiber length I: Torsional moment M: Capillary weight vs. capillary diameter d: Fiber diameter J: Gravitational acceleration However, although the fiber cross section is not strictly circular, here we use yarn weight W, number of single yarns. The fiber diameter was determined using N and specific gravity ρ.
引張弾性率の測定； Ｊ ｌ５−Ｒ−７６０１に従った。Measurement of tensile modulus; According to J 15-R-7601.
次に本発明繊維の製造例をポリアクリロニトリルを出発
原料とした超高弾性率黒鉛繊維について説明する。Next, an example of manufacturing the fiber of the present invention will be described using ultra-high modulus graphite fiber using polyacrylonitrile as a starting material.
既述したように、本発明繊維の第一の藍件は、所望の引
張弾性率においてネジリ弾性率を所定の値より大きくす
ることにある。本発明者らの検討によれば、炭素繊維の
ネジリ弾性率は出発原料の構造と焼成熱履歴の中で、特
に最高温度の影響を受けることが、また引張弾性率はそ
の他に焼成時の張力履歴、特に最高温度での張力の影響
を受けることが明らかとなった。すなわち、まず原糸は
高配向でかつ焼成の過程で配向緩和が起こりにくい共重
合組成であることが重要である。As mentioned above, the first feature of the fiber of the present invention is to make the torsional modulus larger than a predetermined value at a desired tensile modulus. According to the studies of the present inventors, the torsional modulus of carbon fiber is affected by the structure of the starting material and the firing thermal history, especially the maximum temperature, and the tensile modulus is also affected by the tension during firing. It became clear that it is affected by the history, especially the tension at the highest temperature. That is, first of all, it is important that the raw yarn has a copolymer composition that is highly oriented and that orientation relaxation does not easily occur during the firing process.
その意味で、原糸ポリマの共重合量の選択が重要である
。即ち、共重合量が多くなると、所謂ガラス転移点が下
がり、分子鎖が熱緩和を生じ易くなり、焼成の過程、特
に初期の耐炎化の過程で原糸の配向構造が乱され、結果
として弾性率が上げ難いものとなる。従って、共重合量
は一定の値より小さくしておく必要がある。しかも共重
合成分がアクリロニトリルに比し、嵩高いもの、即ち分
子量の大なるものにあっては、この緩和効果が大きいの
で、モル分率で規定するより重量分率で規定する方がよ
り適切である。本発明にあってはその上限は８ｗｔ％で
あり、好ましくは４ｗｔ％以下とすべきである。In this sense, selection of the amount of copolymerization of the yarn polymer is important. In other words, as the amount of copolymerization increases, the so-called glass transition point decreases, the molecular chains tend to undergo thermal relaxation, and the oriented structure of the yarn is disturbed during the firing process, especially during the initial flame resistance process, resulting in a decrease in elasticity. This makes it difficult to increase the rate. Therefore, it is necessary to keep the amount of copolymerization smaller than a certain value. Furthermore, if the copolymerization component is bulkier than acrylonitrile, that is, has a large molecular weight, this relaxation effect is greater, so it is more appropriate to define it by weight fraction than by mole fraction. be. In the present invention, the upper limit is 8 wt%, preferably 4 wt% or less.
次に重要なのは原糸の緻密性である。緻密性が高いと前
述の配向緩和が起こりにクク、かつ緻密な黒鉛繊維が得
られ易い。この緻密で高配向は得られる黒鉛繊維の引張
弾性率を効果的に高める。The next important thing is the density of the yarn. If the density is high, the above-mentioned orientation relaxation will not occur, and dense graphite fibers will be easily obtained. This dense and high orientation effectively increases the tensile modulus of the graphite fibers obtained.
原糸の緻密性は以下の沃素吸＠量によって評価できる。The density of the yarn can be evaluated by the amount of iodine absorbed as shown below.
すなわち、沃素５０（］ 、 ］２．４−ジクロロフェ
ノール１０ｇ酢ｒ！１９０ｃ＋ 、 および沃化カリウ
ム１０Ｏｇを秤量し、水で希釈し、水溶液として１リツ
トルとする。該水溶液１００ｍ１に乾燥試料０．５０を
浸漬し、６０±０．５℃で５０分吸着処理を行なう。試
料は処理後、流水中で３０分水洗後、遠心脱水する。脱
水した試料を１００ｍ１のジメチルスルホキシドに加温
溶解し、１／１０規定の硝酸銀水溶液で電位差滴定によ
り沃素の濃度を求め、乾燥試料に対する沃素吸着ｉ（ｗ
ｔ％）を算出する。That is, 10 g of iodine 50(], ]2,4-dichlorophenol, vinegar r!190c+, and 100 g of potassium iodide are weighed and diluted with water to make 1 liter of an aqueous solution. 0.50 g of the dried sample is added to 100 ml of the aqueous solution. After the treatment, the sample was washed in running water for 30 minutes, and centrifugally dehydrated.The dehydrated sample was heated and dissolved in 100 ml of dimethyl sulfoxide. The concentration of iodine was determined by potentiometric titration with a /10 normal silver nitrate aqueous solution, and the iodine adsorption i (w
t%).
沃素の吸着ｍは、原糸内に存在するミクロボイド必るい
は構造的に粗な部分の口に対応する。従って、緻密な黒
鉛繊維を得ようとする場合には、原糸自体が緻密である
ことが望ましく、上記沃素の吸着量は少ないことが望ま
しい。本発明の目的を達成するためには、その値は３ｗ
ｔ％以下、より好ましくは２Δｔ％以下である。The iodine adsorption m corresponds to the openings of microvoids or structurally rough portions existing within the yarn. Therefore, in order to obtain dense graphite fibers, it is desirable that the yarn itself is dense, and it is desirable that the amount of iodine adsorbed is small. To achieve the purpose of the invention, its value is 3w
It is t% or less, more preferably 2Δt% or less.
原糸の沃素吸着量は、主として製糸条件の中、紡出・凝
固条件、延伸条件、および付与する油剤に左右される。The amount of iodine adsorbed by the raw yarn mainly depends on the spinning conditions, spinning/coagulation conditions, stretching conditions, and the applied oil agent.
即ち、凝固に際してはなるべくドラフトが小ざくなるよ
うに２口金寸法や紡糸速度を設定する必要がおる。その
意味では紡糸原液の濃度は高い方が好ましく、また湿式
紡糸法よりは吐出糸を一旦空気中に走行させる乾湿式紡
糸の方が容易に緻密な原糸が得られるので好ましい。That is, during solidification, it is necessary to set the dimensions of the two spinnerets and the spinning speed so that the draft is as small as possible. In this sense, it is preferable that the concentration of the spinning dope be high, and wet-dry spinning, in which the discharged yarn is once run in the air, is preferable to the wet spinning method, since dense fibers can be obtained more easily.
延伸は緻密な原糸を得る目的からは、乾燥以前の湿潤状
態での延伸を単糸間の接着を生じさせない範囲で、出来
る限り高倍率とし、高温で延伸することが好ましい。ま
た、乾燥以前に適用する油剤は膨潤状態の糸条の内部に
拡散浸透し、緻密性を阻害することがあるので、なるべ
く分子量の大なるものを選定する必要がある。撥水性の
高いシリコン系の油剤はこの点本発明には好適である。For the purpose of obtaining a dense raw yarn, it is preferable to stretch the yarn in a wet state before drying at a high magnification as much as possible and at a high temperature within a range that does not cause adhesion between single yarns. In addition, an oil agent applied before drying may diffuse into the inside of the swollen yarn and impede denseness, so it is necessary to select one with as large a molecular weight as possible. In this respect, silicone-based oils with high water repellency are suitable for the present invention.
このようにして、緻密なアクリル繊維を形成させた後、
焼成して黒鉛繊維に転換する工程の流れは、通常の焼成
技術と同様である。即ち、酸化性雰囲気での熱処理によ
る耐炎化を施し、次いで不活性雰囲気中で少なくとも１
０００℃以上の炭化処理を施した後、さらに高温で黒鉛
化処理を施すことからなる。ただし、この過程で次のよ
うな条件を採用することが必要である。After forming dense acrylic fibers in this way,
The flow of the process of firing and converting into graphite fibers is the same as that of normal firing technology. That is, flame resistance is achieved by heat treatment in an oxidizing atmosphere, and then at least one heat treatment is performed in an inert atmosphere.
After carbonization treatment is performed at a temperature of 000° C. or higher, graphitization treatment is further performed at a high temperature. However, it is necessary to adopt the following conditions in this process.
耐炎化は通常２００〜３００ ’Ｃの空気中で加熱する
ことにより、ポリアクリロニトリルを環化、および酸化
することによって耐熱性を向上させる工程である。かく
して環化、酸化されたポリアクリロニトリルはその化学
的な構造の変化に従い、吸湿性を示すことが知られてお
り、吸着水分量はその反応量の指標でもある。本発明の
高圧縮強度を有する緻密な黒鉛繊維を得るためには、こ
の反応量はめる程度低く抑えることが必要である。例え
ば、特公昭４４−２１１７５公報などの教えに従えば、
耐炎化では実質的に完全に酸素が内部に浸透するまで行
なうことが好ましいとされているが、本発明者らの検討
によれば、その理由は必ずしも明確ではないが、酸素の
浸透が多過ぎると、その後の炭化工程でミクロボイドの
生成が多く、比重の低いものとなる傾向が強いことが認
められた。Flame resistance is usually a process of improving heat resistance by cyclizing and oxidizing polyacrylonitrile by heating in air at 200 to 300'C. Polyacrylonitrile that has been cyclized and oxidized in this way is known to exhibit hygroscopicity due to changes in its chemical structure, and the amount of adsorbed water is also an indicator of the amount of reaction. In order to obtain the dense graphite fibers with high compressive strength of the present invention, it is necessary to suppress this reaction amount to an acceptable level. For example, if you follow the teachings of Japanese Patent Publication No. 44-21175,
It is said that it is preferable to carry out flameproofing until oxygen has substantially completely penetrated into the interior, but according to the inventors' study, the reason for this is not necessarily clear, but oxygen penetration is too high. It was observed that many microvoids were generated in the subsequent carbonization process, and there was a strong tendency for the specific gravity to be low.
さて、ここで耐炎化繊維の吸着水分量は以下のようにし
て求めることができる。耐炎化糸を固相共存硫酸アンモ
ニウム水溶液を下部に入れたデシケータ中に室温で約１
６時間放置し、平衡吸着に達した水分量を重量法により
算出する。Now, the amount of moisture adsorbed by the flame-resistant fiber can be determined as follows. The flame-retardant thread was placed in a desiccator containing a solid phase coexisting ammonium sulfate aqueous solution at the bottom for about 1 hour at room temperature.
After leaving it for 6 hours, the amount of water that has reached equilibrium adsorption is calculated by gravimetric method.
先のように、十分酸素が浸透するまで耐炎化した場合に
は、この値は１０数％にも達するが、本発明の目的を達
成するためにはこの値は７％以下とするのがよい。下限
は特に限定されないが、低過ぎると炭化収率が低下し、
コスト高になるし、また更に低くなると炭化時に糸切れ
を生じるなど生産に支障を来たすので、３〜４％程度が
好ましい。As mentioned above, if flame resistance is achieved to the point where sufficient oxygen permeates, this value can reach as high as 10%, but in order to achieve the purpose of the present invention, this value should be kept at 7% or less. . The lower limit is not particularly limited, but if it is too low, the carbonization yield will decrease,
The content is preferably about 3 to 4%, since it increases the cost, and if it becomes even lower, it causes problems in production, such as thread breakage during carbonization.
次に重要なのは焼成工程で配向緩和を極力抑えることで
おる。一般に炭素繊維用原糸は高度の延伸倍率で延伸し
、配向の高い繊維としたものが用いられるが、この配向
が焼成の途中で緩和してしまうと無意味となる。特に、
耐炎化の初期において原糸の配向の緩和が生じ易いので
、これを防止することが肝要である。通常原糸であるポ
リアクリロニトリルのＸ線による配向度は８５％以上、
好ましくは９０％以上のものが用いられる。The next important thing is to suppress orientation relaxation as much as possible during the firing process. Generally, carbon fiber yarns are drawn at a high draw ratio to produce highly oriented fibers, but if this orientation is relaxed during firing, it becomes meaningless. especially,
At the initial stage of flame resistance, the orientation of the filaments tends to relax, so it is important to prevent this. The degree of orientation of polyacrylonitrile, which is usually a raw yarn, is 85% or more by X-rays,
Preferably, 90% or more is used.
この原糸における配向は、得られる炭化糸のグラファイ
ト結晶に反映されることは間違いないが、炭素繊維とし
て必要なのはグラフフィト構造の配向度である。一般に
耐炎化を施したものについては、ニトリル基の環化構造
連鎖の生成により、Ｘ線回折を行なうと既にグラフフィ
ト網面に相当する回折パターンが認められる。本発明の
目的を達成するためには、原糸の配向度の如何に拘らず
、得られる耐炎化糸のグラフフィト細面の面指数（００
２＞に相当する回折より求められる配向度が７８％以上
、好ましくは８０％以上となるようにすべきである。こ
こでの配向度が高いことが、より低温でグラファイトの
結晶構造の発達を抑制しつつ、高い圧縮強度を有する黒
鉛繊維を得ようとする本発明の目的を実現するのに極め
て重要なことである。There is no doubt that the orientation in the raw yarn is reflected in the graphite crystals of the carbonized yarn obtained, but what is necessary for carbon fibers is the degree of orientation of the graphite structure. In general, when flame-retardant is applied, a diffraction pattern corresponding to a graphite network is already observed when X-ray diffraction is performed due to the formation of a cyclized chain of nitrile groups. In order to achieve the object of the present invention, regardless of the degree of orientation of the raw yarn, the surface index (00
The degree of orientation determined by diffraction corresponding to 2> should be 78% or more, preferably 80% or more. This high degree of orientation is extremely important in achieving the objective of the present invention, which is to obtain graphite fibers with high compressive strength while suppressing the development of the graphite crystal structure at lower temperatures. be.
この耐炎化糸の配向度の値を制御する工程要因としては
下記のものを挙げることができる。即ら、耐炎化の温度
、張力のほか、耐炎化の雰囲気などである。温度は高い
と、環化に先立ちポリアクリロニトリルの配向緩和が先
ず生じるので好ましくないし、張力はできる限り高く保
つべきである。Process factors that control the degree of orientation of the flame-resistant yarn include the following. That is, in addition to the temperature and tension for flame resistance, the atmosphere for flame resistance, etc. High temperatures are undesirable as this will first cause the polyacrylonitrile to relax its orientation prior to cyclization, and the tension should be kept as high as possible.
耐炎化の雰囲気については、理由は明確ではないが、酸
素濃度が１５％よりも下回ると配向の高い、即ら黒鉛化
した時に弾性率の発現し易い耐炎化糸を得ることができ
ない。As for the flame resistant atmosphere, although the reason is not clear, if the oxygen concentration is less than 15%, it is impossible to obtain a flame resistant yarn that is highly oriented, that is, easily exhibits elastic modulus when graphitized.
むろん、この他に原糸の配向度を高めておくこと、単繊
維デニールはなるべく細いものを使用すること、また既
述したように共重合成分の量はなるべく少なくすること
などの配慮も重要である。Of course, other considerations are also important, such as increasing the degree of orientation of the yarn, using single fibers with as thin a denier as possible, and as mentioned above, minimizing the amount of copolymerization components. be.
かくして得られた耐炎化繊維は黒鉛化に供されるに当り
、少なくとも１０００’Ｃ以上で炭化し得られる炭化糸
の吸着水分率が０．５％以下になるようにする。こうす
ることにより黒鉛化での延伸に十分耐え得ることのでき
る炭化糸となり、延伸による配向向上効果が大きくなる
。黒鉛化は原反に対して５％以上、好ましくは７％〜１
５％の延伸を行なう。延伸に際しては黒鉛化最高温度２
４００’ＣＤ上で、１０００℃以上の滞留時間ハ４０秒
以上、好ましくは１分から３分程度にする。このように
することにより超高弾性率であって、圧縮強度の優れた
黒鉛１維にすることができる。When the flame-resistant fiber thus obtained is subjected to graphitization, it is carbonized at at least 1000'C or higher so that the adsorbed moisture content of the resulting carbonized fiber is 0.5% or less. By doing so, the carbonized yarn can sufficiently withstand stretching during graphitization, and the effect of improving orientation by stretching becomes greater. Graphitization is 5% or more, preferably 7% to 1% of the original fabric.
Stretch by 5%. Maximum graphitization temperature 2 during stretching
On a 400'CD, the residence time at 1000°C or higher is set to 40 seconds or more, preferably about 1 minute to 3 minutes. By doing so, it is possible to obtain a graphite fiber having an ultra-high modulus of elasticity and excellent compressive strength.
［実施例］ 以下、実施例により本発明を一層具体的に説明する。[Example] Hereinafter, the present invention will be explained in more detail with reference to Examples.
実施例１
アクリロニトリル９９讐ｔ％、メタクリル酸１ｗｔ％よ
りなるアクリロニトリル系重合体をジメチルスルホギシ
ド（以下、０Ｍ５Ｏ）溶液中で常法により重合し、［η
］＝１．８（４５℃における溶液粘度６００ボイズ）の
重合体溶液を得た。Example 1 An acrylonitrile-based polymer consisting of 99t% acrylonitrile and 1wt% methacrylic acid was polymerized in a dimethyl sulfogide (hereinafter referred to as 0M5O) solution by a conventional method, and [η
] = 1.8 (solution viscosity at 45°C: 600 voids) was obtained.
これを直径０．２ｍ、孔数３０００の口金を用い、−旦
空気中に吐出し、ついで３０％、１５℃のＤＨ３Ｏ水溶
液に導き凝固させた。This was first discharged into the air using a nozzle with a diameter of 0.2 m and 3000 holes, and then introduced into a 30% DH3O aqueous solution at 15°C to solidify.
凝固糸は水洗、熱水延伸後、アミノシロキサンを主成分
とする油剤を付与し、乾燥緻密化後、５゜５ Ｋ（］／
ｍｍ” Ｇの加圧スチーム中で延伸し、全倍率１２．
４倍、単糸繊度０．７６の原糸を採取した。The coagulated yarn was washed with water, stretched with hot water, applied with an oil agent mainly composed of aminosiloxane, dried and densified, and then heated to 5°5 K (]/
Stretched in a pressurized steam of 1.5 mm"G, with a total magnification of 12.
A raw yarn with a diameter of 4 times and a single yarn fineness of 0.76 was collected.
この原糸は強度７．５ａ／ｄ 、伸度１１．８％２本文
中に記載した方法で求めたヨウ素吸着量は１゜２％であ
った。Ｘ線回折により求めた配向度は９１．４％であっ
た。This yarn had a strength of 7.5 a/d and an elongation of 11.8%2.The amount of iodine adsorption determined by the method described in the text was 1.2%. The degree of orientation determined by X-ray diffraction was 91.4%.
得られた原糸を２４０℃の加熱空気中、伸長率１．０８
倍の緊張熱処理を５分間施し、次いで２５０〜２７０℃
の温度勾配を有する加熱空気中で耐炎化を施した。The obtained yarn was heated in air at 240°C with an elongation rate of 1.08.
Heat treatment under tension for 5 minutes, then at 250-270°C
Flame resistance was applied in heated air with a temperature gradient of .
耐炎化繊維の水分率は５．８％、Ｘ線回折によるグラフ
ァイト網面に相当するグラファイト前駆体構造の配向度
は８２．３％でおった。The moisture content of the flame-resistant fiber was 5.8%, and the degree of orientation of the graphite precursor structure corresponding to the graphite network plane by X-ray diffraction was 82.3%.
かくして得られた耐炎糸を４００〜１０００’Ｃの温度
勾配を有する窒素雰囲気にシールされた炭化炉に、原反
よりも短くならないよう緊張下に保持して炭化し、さら
に最高温度２６５０℃で黒鉛化処理を行なった。この際
、原反よりも約１５％の延伸を施した。The thus obtained flame-resistant yarn is carbonized in a carbonization furnace sealed in a nitrogen atmosphere with a temperature gradient of 400 to 1000'C, held under tension so that it does not become shorter than the original fabric, and then carbonized at a maximum temperature of 2650°C. processing was performed. At this time, the film was stretched approximately 15% more than the original film.
得られた黒鉛化繊維の物性はＪＩＳ−Ｒ−７６０１に従
って含浸ストランド法によって求め、４５０Ｋｇ／ｍ
、引張弾性率６０ｔ／ｍ”と、極めて強度の高い黒鉛化
糸が１ｑられた。このもののネジリ弾性率は１ 、８
ｔ／ｍ２であった。The physical properties of the graphitized fiber obtained were determined by the impregnated strand method according to JIS-R-7601, and the properties were determined at 450 kg/m.
, 1q of extremely strong graphitized yarn with a tensile modulus of 60 t/m'' was produced.The torsional modulus of this yarn was 1.8.
It was t/m2.
上記黒鉛化繊維を用いて、三弗化硼素モノエチルアミン
を配合したエポキシ樹脂（商品名：エピコート８２８．
シェル！！りをマトリックスとし、繊維含有率的６０％
で常法により複合材料テストピースを作成し、コンポジ
ット評価を行なった。Epoxy resin (trade name: Epicoat 828.
shell! ! The fiber content is 60%.
A composite material test piece was prepared using a conventional method, and the composite was evaluated.
引張強度は１７０Ｋｇ／ ｍｍ２．曲げ強度は１１０Ｋ
（］／ｓ、圧縮強度は１００ Ｋ（］／ ｒＮｎ２であ
り、特に引張弾性率が６０ｔ／ｓ２と高い黒鉛化糸を用
いた複合材料としては圧縮強度の極めて高いものである
ことが認められた。Tensile strength is 170Kg/mm2. Bending strength is 110K
(]/s, the compressive strength was 100 K(]/rNn2, and it was recognized that the compressive strength was extremely high, especially for a composite material using graphitized yarn with a high tensile modulus of 60 t/s2. .
実施例２
実施例１と同一ポリマを用い、総孔数６０００ で２口
金吐出孔径を０．０５〜００７５ｍφの範囲内で、また
凝固引取速度を変更することにより紡糸の実質ドラフト
を変更して、湿式紡糸法によりブレカーサを製造した。Example 2 Using the same polymer as in Example 1, the total number of holes was 6000, the diameter of the two-mouth discharge hole was within the range of 0.05 to 0075 mφ, and the actual draft of spinning was changed by changing the coagulation and take-off speed. Brecasa was manufactured by wet spinning method.
なお、ここで実質ドラフトとは凝固条件における引取速
度（Ｖｉ ）と自由吐出線速度（Ｖｆ ）との比、町／
Ｖ（である。Note that the actual draft here refers to the ratio of the take-up speed (Vi) to the free discharge linear velocity (Vf) under coagulation conditions.
V (is.
その他の条件は実施例１に準じたが、ドラフトによって
は全延伸倍率１２．４倍の設定が不能のものがあり、そ
の場合は可能な限り高倍率に設定した。Other conditions were the same as in Example 1, but depending on the draft, there were cases where it was impossible to set the total stretching ratio of 12.4 times, and in that case, the ratio was set as high as possible.
また黒鉛化温度および黒鉛化延伸比はほぼ引張弾性率が
５５ ｔ／ｓ２になるように、各水準について設定した
。Further, the graphitization temperature and graphitization stretching ratio were set for each level so that the tensile modulus was approximately 55 t/s2.
主要条件と）ｑられた結果を第１表に示す。The main conditions and results are shown in Table 1.
この結果から明らかなように、原糸の緻密性が低く、ヨ
ウ素吸着の大なるものは引張弾性率が高くなり難く、黒
鉛化温度および黒鉛化延伸比を上げる必要がある。また
ヨウ素吸着量の小なるものでも黒鉛化延伸比が低いもの
はネジリ弾性率が低く、コンポジットの圧縮強度が低く
なる傾向から。As is clear from this result, if the density of the raw yarn is low and the iodine adsorption is large, the tensile modulus is difficult to increase, and it is necessary to increase the graphitization temperature and graphitization draw ratio. In addition, even if the amount of iodine adsorbed is small, those with a low graphitization stretch ratio have a low torsional modulus, and the compressive strength of the composite tends to be low.
黒鉛化温度を高くする必要がおる。It is necessary to increase the graphitization temperature.
（以下、余白）
実施例３
実施例２で得られた原糸を用い、引張弾性率が６０ｔ／
ｍ２になるように焼成した。(Hereinafter, blank space) Example 3 Using the yarn obtained in Example 2, the tensile modulus was 60t/
It was fired to a size of m2.
主要条件と得られた結果を第２表に示す。The main conditions and the results obtained are shown in Table 2.
この結果から明らかなように、緻密性の高い原糸でも黒
鉛化温度を極端に上げたものはネジリ弾性率が低く、圧
縮強度が低いことがわかる。As is clear from these results, even if the yarn is highly dense, the yarn whose graphitization temperature is extremely raised has a low torsional modulus and a low compressive strength.
また実施例２，３の結果を整理し図示すると、第２図の
ようになる。図中の実線は本発明規定のＧｆ≧２．１５
−０．０１５Ｅｆ
であり、実線より上方の白丸印の圧縮強度はいずれも１
００ Ｋ（１／ ｍｍ２以上と優れた物性を示すことが
わかる。Furthermore, when the results of Examples 2 and 3 are organized and illustrated, they are as shown in FIG. 2. The solid line in the figure indicates Gf≧2.15 defined by the present invention.
-0.015Ef, and the compressive strengths of the white circles above the solid line are all 1
It can be seen that it exhibits excellent physical properties of 00 K (1/mm2 or more).
（以下、余白）
［発明の効果］
上述した如く、本発明の黒鉛繊維はその構造の異方性を
制御することにより所望の引張弾性率との関連において
ネジリ弾性率を所定の値以上、例えば、引張弾性率５５
ｔ／ｓ＋＋２において、１．３３ｔ ／ｒｒｖｎ ”
以上とする点に特徴がある。これによりプラスチックを
マトリックスとした複合材料において、圧縮強度が１０
０ＫＯ／ｓ”以上となり、従来の黒鉛繊維に比較して弾
性率が低下することなく圧縮強度が一段と向上し、力学
特性が均衡化したため、軽量構造材としてより一層の薄
肉軽量化が図れるという、顕著な効果を奏するのである
。(Hereinafter, blank space) [Effects of the Invention] As described above, the graphite fiber of the present invention has a torsional modulus of elasticity greater than a predetermined value, e.g., in relation to a desired tensile modulus, by controlling the anisotropy of its structure. , tensile modulus 55
At t/s++2, 1.33t/rrvn”
It is characterized by the above points. This results in a compressive strength of 10% in plastic matrix composite materials.
0KO/s" or more, the compressive strength is further improved without decreasing the elastic modulus compared to conventional graphite fibers, and the mechanical properties are balanced, making it possible to achieve even thinner and lighter weight structural materials. It has a remarkable effect.
第１図は黒鉛繊維のネジリ弾性率Ｇｆの測定方法を示す
概略図、第２図は黒鉛繊維のネジリ弾性率Ｇ［と圧縮強
度の関係を示す図である。
（符号の説明）
１：単繊維（黒鉛繊維）
２ニガラス毛細管
３：クリップ
引張弾性率（ｔ／１１１１２）
第２図FIG. 1 is a schematic diagram showing a method for measuring the torsional modulus Gf of graphite fibers, and FIG. 2 is a diagram showing the relationship between the torsional modulus G of graphite fibers and compressive strength. (Explanation of symbols) 1: Single fiber (graphite fiber) 2 Glass capillary 3: Clip tensile modulus (t/11112) Fig. 2
Claims (1)
を特徴とする高い圧縮強度を有する黒鉛繊維。 Ｇ＿ｆ≧２．１５−０．０１５Ｅ＿ｆ Ｅ＿ｆ≧５５ ただし、Ｇ＿ｆ；ネジリ弾性率（ｔ／ｍｍ＾２）Ｅ＿ｆ
；引張弾性率（ｔ／ｍｍ＾２）[Claims] A graphite fiber having high compressive strength, characterized in that its torsional modulus and compressive modulus satisfy the following formula. G_f≧2.15-0.015E_f E_f≧55 However, G_f; Torsional elastic modulus (t/mm^2) E_f
;Tensile modulus (t/mm^2)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28153687A JPH01124629A (en) | 1987-11-06 | 1987-11-06 | Graphite fiber having high compressive strength |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP28153687A JPH01124629A (en) | 1987-11-06 | 1987-11-06 | Graphite fiber having high compressive strength |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01124629A true JPH01124629A (en) | 1989-05-17 |
Family
ID=17640541
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP28153687A Pending JPH01124629A (en) | 1987-11-06 | 1987-11-06 | Graphite fiber having high compressive strength |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01124629A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04240221A (en) * | 1991-01-23 | 1992-08-27 | Toray Ind Inc | Graphitized fiber |
| US5395607A (en) * | 1992-06-30 | 1995-03-07 | Tonen Corporation | High compressive strength pitch based carbon fiber |
| US6600660B2 (en) | 1999-03-24 | 2003-07-29 | Nec Corporation | Plug-in unit storage rack-type apparatus |
| JP2009221619A (en) * | 2008-03-14 | 2009-10-01 | Toho Tenax Co Ltd | Precursor fiber and method for producing precursor fiber, flame-resistant fiber and carbon fiber |
| JP2012246596A (en) * | 2012-07-24 | 2012-12-13 | Toho Tenax Co Ltd | Precursor fiber and method for producing precursor fiber, flameproof fiber and carbon fiber |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54112214A (en) * | 1978-02-16 | 1979-09-03 | Toho Rayon Co Ltd | Production and device for high-tensile and high-modulus graphite fibers |
| JPS575922A (en) * | 1980-06-09 | 1982-01-12 | Mitsubishi Rayon Co Ltd | Preparation of graphite fiber |
| JPS57121623A (en) * | 1981-01-20 | 1982-07-29 | Mitsubishi Rayon Co Ltd | Preparation of graphite fiber |
-
1987
- 1987-11-06 JP JP28153687A patent/JPH01124629A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS54112214A (en) * | 1978-02-16 | 1979-09-03 | Toho Rayon Co Ltd | Production and device for high-tensile and high-modulus graphite fibers |
| JPS575922A (en) * | 1980-06-09 | 1982-01-12 | Mitsubishi Rayon Co Ltd | Preparation of graphite fiber |
| JPS57121623A (en) * | 1981-01-20 | 1982-07-29 | Mitsubishi Rayon Co Ltd | Preparation of graphite fiber |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04240221A (en) * | 1991-01-23 | 1992-08-27 | Toray Ind Inc | Graphitized fiber |
| US5395607A (en) * | 1992-06-30 | 1995-03-07 | Tonen Corporation | High compressive strength pitch based carbon fiber |
| US6600660B2 (en) | 1999-03-24 | 2003-07-29 | Nec Corporation | Plug-in unit storage rack-type apparatus |
| JP2009221619A (en) * | 2008-03-14 | 2009-10-01 | Toho Tenax Co Ltd | Precursor fiber and method for producing precursor fiber, flame-resistant fiber and carbon fiber |
| JP2012246596A (en) * | 2012-07-24 | 2012-12-13 | Toho Tenax Co Ltd | Precursor fiber and method for producing precursor fiber, flameproof fiber and carbon fiber |
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