JPH0561367B2 - - Google Patents
Info
- Publication number
- JPH0561367B2 JPH0561367B2 JP23530684A JP23530684A JPH0561367B2 JP H0561367 B2 JPH0561367 B2 JP H0561367B2 JP 23530684 A JP23530684 A JP 23530684A JP 23530684 A JP23530684 A JP 23530684A JP H0561367 B2 JPH0561367 B2 JP H0561367B2
- Authority
- JP
- Japan
- Prior art keywords
- pitch
- spinning
- fiber
- cross
- carbon 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.)
- Expired - Lifetime
Links
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 56
- 239000004917 carbon fiber Substances 0.000 claims description 56
- 239000000835 fiber Substances 0.000 claims description 48
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 38
- 239000013078 crystal Substances 0.000 claims description 18
- 238000002441 X-ray diffraction Methods 0.000 claims description 5
- 230000001747 exhibiting effect Effects 0.000 claims description 2
- 239000011295 pitch Substances 0.000 description 67
- 238000009987 spinning Methods 0.000 description 50
- 230000000704 physical effect Effects 0.000 description 19
- 241000446313 Lamella Species 0.000 description 15
- 238000010438 heat treatment Methods 0.000 description 13
- 238000002844 melting Methods 0.000 description 11
- 230000008018 melting Effects 0.000 description 11
- 230000003287 optical effect Effects 0.000 description 8
- 239000011337 anisotropic pitch Substances 0.000 description 6
- 229920002239 polyacrylonitrile Polymers 0.000 description 6
- 239000002994 raw material Substances 0.000 description 6
- 238000002074 melt spinning Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- SMWDFEZZVXVKRB-UHFFFAOYSA-N Quinoline Chemical compound N1=CC=CC2=CC=CC=C21 SMWDFEZZVXVKRB-UHFFFAOYSA-N 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000010304 firing Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 241000234282 Allium Species 0.000 description 3
- 235000002732 Allium cepa var. cepa Nutrition 0.000 description 3
- 239000003245 coal Substances 0.000 description 3
- 230000001276 controlling effect Effects 0.000 description 3
- 230000007547 defect Effects 0.000 description 3
- 238000009826 distribution Methods 0.000 description 3
- 239000012299 nitrogen atmosphere Substances 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 239000003208 petroleum Substances 0.000 description 3
- 239000000843 powder Substances 0.000 description 3
- 238000012545 processing Methods 0.000 description 3
- 238000011160 research Methods 0.000 description 3
- 238000005245 sintering Methods 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 239000011294 coal tar pitch Substances 0.000 description 2
- 239000002131 composite material Substances 0.000 description 2
- 230000000875 corresponding effect Effects 0.000 description 2
- 239000000295 fuel oil Substances 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 239000004973 liquid crystal related substance Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000000047 product Substances 0.000 description 2
- 238000001878 scanning electron micrograph Methods 0.000 description 2
- 238000009736 wetting Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229920000297 Rayon Polymers 0.000 description 1
- AZDRQVAHHNSJOQ-UHFFFAOYSA-N alumane Chemical compound [AlH3] AZDRQVAHHNSJOQ-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000010426 asphalt Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 238000003763 carbonization Methods 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 239000011280 coal tar Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000002596 correlated effect Effects 0.000 description 1
- 238000007872 degassing Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000001125 extrusion Methods 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 238000005984 hydrogenation reaction Methods 0.000 description 1
- 238000010191 image analysis Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- PNDPGZBMCMUPRI-UHFFFAOYSA-N iodine Chemical compound II PNDPGZBMCMUPRI-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000013081 microcrystal Substances 0.000 description 1
- 238000001000 micrograph Methods 0.000 description 1
- 239000003027 oil sand Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- 239000002964 rayon Substances 0.000 description 1
- 239000012783 reinforcing fiber Substances 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- 239000011269 tar Substances 0.000 description 1
- 238000010998 test method Methods 0.000 description 1
- 238000011144 upstream manufacturing Methods 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
- 238000004736 wide-angle X-ray diffraction Methods 0.000 description 1
Landscapes
- Inorganic Fibers (AREA)
Description
【発明の詳細な説明】
［産業上の利用分野］
本発明は新規でかつ特異な内部断面構造を有
し、且つ、特異なミクロ構造を有する高強度、高
モジユラスのピツチ系炭素繊維に関するものであ
る。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a high-strength, high-modulus pitch-based carbon fiber having a novel and unique internal cross-sectional structure and a unique microstructure. be.
［従来技術］
炭素繊維は、当初レーヨンを原料として製造さ
れたが、その特性ならびに経済性の点で、現在
は、ポリアクリロニトリル（PAN）繊維を原料
とするPAN系炭素繊維と石炭又は石油系のピツ
チ類を原料とするピツチ系炭素繊維によつて占め
られている。なかでも、ピツチを原料として高性
能グレートの炭素繊維を製造する技術は、経済性
にすぐれているため注目を集めており、例えば、
光学異方性ピツチを溶融紡糸して得たピツチ繊維
を不融化・焼成した炭素繊維は、それまでのピツ
チ系炭素繊維に比して高強度、高モジユラスのも
のが得られている（例えば、特開昭49−19127号
公報参照）。[Prior art] Carbon fiber was initially produced using rayon as a raw material, but due to its characteristics and economic efficiency, it is now produced using PAN-based carbon fiber, which is made from polyacrylonitrile (PAN) fiber, and coal-based or petroleum-based carbon fiber. It is dominated by pituti-based carbon fibers made from pituti. Among these, the technology to produce high-performance grade carbon fiber using pituti as a raw material is attracting attention due to its excellent economic efficiency.For example,
Carbon fibers obtained by infusible and fired pitch fibers obtained by melt-spinning optically anisotropic pitch fibers have higher strength and higher modulus than conventional pitch carbon fibers (for example, (Refer to Japanese Patent Application Laid-open No. 19127-1983).
また、ピツチ系炭素繊維の内部断面構造を制御
することにより、更に高い物性が発現し得るとい
うことも見出されている（Fuel，1980，60，
839，特開昭59−53717号公報参照）。すなわち、
ピツチ系炭素繊維の断面構造としては、ランダ
ム、ラジアル、オニオン構造又はその複合構造が
存在し、ラジアル構造は、クラツクを生じやすく
マクロ欠陥による物性低下が生じるため好ましく
ないとされている。 It has also been discovered that even higher physical properties can be developed by controlling the internal cross-sectional structure of pitch-based carbon fibers (Fuel, 1980, 60 ,
839, see Japanese Unexamined Patent Publication No. 59-53717). That is,
The cross-sectional structures of pitch-based carbon fibers include random, radial, onion structures, or composite structures thereof. Radial structures are considered unfavorable because they tend to cause cracks and deteriorate physical properties due to macro defects.
そして、ピツチ系炭素繊維におけるランダム構
造は、実際はラメラのサイズが小さいラジアル構
造であり、強度的には好ましい構造と考えられる
が、ピツチ調製及び紡糸の高ドラフト化又は急冷
化が充分でないとクラツクが生じやすいため、製
造条件が限定される。 The random structure in pitch-based carbon fibers is actually a radial structure with small lamella sizes, and is considered to be a preferable structure in terms of strength, but cracks may occur if the pitch preparation and spinning draft or rapid cooling are not sufficient. Since this occurs easily, manufacturing conditions are limited.
オニオン構造は、現象的には紡糸ピツチの粘性
変化温度よりも高い温度まで昇温させた後、紡糸
することによつて得られるが（特開昭59−53717
号公報参照）、通常の光学異方性ピツチにおいて
は、この粘性変化温度が350℃以上の高温である
ため、紡糸の安定性が悪く、得られる繊維もボイ
ドを含んだものになりやすいため、ボイドレスの
オニオン構造の繊維を溶融紡糸で安定に得ること
は極めてむつかしい。 The onion structure can be obtained by spinning after raising the temperature of the spinning pitch to a temperature higher than the viscosity change temperature.
In the case of ordinary optically anisotropic pitches, the viscosity change temperature is as high as 350°C or higher, resulting in poor spinning stability and the resulting fibers tend to contain voids. It is extremely difficult to stably obtain void-free onion-structured fibers by melt spinning.
このため、従来のピツチ系炭素繊維は引張強度
が高々300Kg／mm2どまりであり、その用途が制限
されているのが実情である。 For this reason, the tensile strength of conventional pitch-based carbon fibers is only 300 kg/mm 2 at most, which limits its use.
［発明が解決しようとする課題］
本発明者らは、強度、モジユラスなどの性能に
おいてPAN系炭素繊維に匹敵するか、より優れ
ているピツチ系炭素繊維を開発するために鋭意研
究を行つた結果、光学的異方性ピツチを溶融紡糸
する際、特別の工夫を加えることにより、ピツチ
分子の配列を意のままに制御できることを究明
し、従来のラジアル、ランダム又はオニオン構造
とは全く異なつた特異な断面内部構造を有し、
PAN系炭素繊維に匹敵する優れた物性（機械的
性質）を示す、新規なピツチ系炭素繊維が得られ
ることを見出し、さきに特願昭59−125048号（特
開昭61−6314号）において、炭素繊維の断面の少
なくとも30％にリーフ状ラメラ配列を有する新規
なピツチ系炭素繊維を提案した。[Problems to be Solved by the Invention] The present inventors have conducted extensive research to develop pitch-based carbon fibers that are comparable to or superior to PAN-based carbon fibers in terms of performance such as strength and modulus. , discovered that when optically anisotropic pitch is melt-spun, the arrangement of pitch molecules can be controlled at will by adding a special device, creating a unique structure that is completely different from conventional radial, random, or onion structures. It has a cross-sectional internal structure,
It was discovered that a new pitch-based carbon fiber showing excellent physical properties (mechanical properties) comparable to PAN-based carbon fiber could be obtained, and was previously published in Japanese Patent Application No. 59-125048 (Japanese Unexamined Patent Publication No. 61-6314). proposed a new pitch-based carbon fiber with a leaf-like lamella arrangement in at least 30% of the cross section of the carbon fiber.
ここでいう「リーフ状ラメラ配列」とは、炭素
繊維の長さ方向とほぼ垂直な方向に切断した断面
を走査型電子顕微鏡（SEM）によつて観察する
ことにより識別できるもので、中心軸から対称に
15〜90°の角度、好ましくは45〜90°の角度で多数
のラメラが両側に伸びた木の葉状のラメラ配列を
指し、従来全く知られていなかつた新規な構造で
ある。かかる繊維は300Kg／mm2を超える優れた引
張強度を示すもので有用性の大きなものである。 The "leaf-like lamellar arrangement" referred to here can be identified by observing a cross section cut almost perpendicular to the length direction of the carbon fiber using a scanning electron microscope (SEM), and can be identified from the central axis. symmetrically
It refers to a leaf-like lamellar arrangement in which a large number of lamellae extend on both sides at an angle of 15 to 90 degrees, preferably an angle of 45 to 90 degrees, and is a novel structure completely unknown in the past. Such fibers exhibit excellent tensile strength exceeding 300 Kg/mm 2 and are highly useful.
本発明者らは、かかる知見に立脚し、さきに提
案したものよりも更に優れた性能を有するピツチ
系炭素繊維を得るべく鋭意研究した結果、リーフ
状ラメラ配列を有する繊維にあつては、その配向
角および結晶サイスを特定範囲に制御することに
より、その物性が飛躍的に向上する事実を見出
し、本発明を完成するに至つた。 Based on this knowledge, the present inventors conducted intensive research to obtain a pitch-based carbon fiber with even better performance than the one proposed earlier. The present inventors have discovered that by controlling the orientation angle and crystal size within a specific range, the physical properties of the material can be dramatically improved, leading to the completion of the present invention.
［課題を解決するための手段］
すなわち、本発明のピツチ系炭素繊維は、繊維
の断面形状が実質的に楕円形であつて、繊維断面
の50％以上にリーフ状ラメラ配列を有し、且つ、
Ｘ線回折より求められる配向角（OA）が20〜
35°、結晶サイズ（Lc）が15〜40Åを示すミクロ
構造を有し、しかも、引張強度が少なくとも550
Kg／mm2、モジユラスが少なくとも20T／mm2である
ことを特徴とするピツチ系炭素繊維である。[Means for Solving the Problems] That is, the pitch-based carbon fiber of the present invention has a fiber having a substantially elliptical cross-sectional shape, a leaf-like lamella arrangement in 50% or more of the fiber cross-section, and ,
Orientation angle (OA) determined by X-ray diffraction is 20~
35°, has a microstructure exhibiting a crystal size (Lc) of 15-40 Å, and has a tensile strength of at least 550 Å.
Kg/mm 2 and modulus of at least 20T/mm 2 .
本発明のピツチ系炭素繊維は、実質的に楕円形
の断面形状を持ち、且つ特殊な繊維断面構造（ラ
メラ配列）とともに特定のミクロ構造を有する。
このため、本発明の繊維では、上述の特願昭59−
125048号で定義されたリーフ状ラメラ配列とは見
掛け上若干異なるリーフ状ラメラ配列を有する場
合がある。すなわち、SEMにより観察した場合、
特願昭59−125048号に記載された中心軸が不明瞭
となり、実質上認められない場合もある。しか
し、この場合でも本来有していた中心軸がSEM
的に観察されなくなつたと理解すべきであり、こ
の考えに基づき、中心軸を仮想することにより、
このようなラメラ配列も上述の定義に従つたリー
フ状ラメラ配列の範ちゆうに属することが理解さ
れる。 The pitch-based carbon fiber of the present invention has a substantially elliptical cross-sectional shape, a special fiber cross-sectional structure (lamellar arrangement), and a specific microstructure.
Therefore, in the fiber of the present invention, the above-mentioned patent application No.
It may have a leaf-like lamella arrangement that is slightly different in appearance from the leaf-like lamella arrangement defined in No. 125048. In other words, when observed by SEM,
In some cases, the central axis described in Japanese Patent Application No. 125048/1983 becomes unclear and is virtually unrecognizable. However, even in this case, the original central axis of the SEM
Based on this idea, by imagining the central axis,
It is understood that such a lamellar arrangement also falls within the category of leaf-like lamellar arrangement according to the above definition.
したがつて、本発明におけるリーフ状ラメラ配
列とは、中心軸が明瞭に観察されるものばかりで
なく、観察されないものも含み、中心軸が認めら
れないものは、中心軸を仮想することで上述の定
義に従うラメラ配列と解する。 Therefore, the leaf-like lamella arrangement in the present invention includes not only those in which the central axis is clearly observed, but also those in which the central axis is not observed. It is interpreted as a lamellar arrangement according to the definition of
本発明のピツチ系炭素繊維は、このようなリー
フ状ラメラ配列を、繊維断面積に占める割合にし
て、50％以上有することを第１の特徴とする。 The first feature of the pitch-based carbon fiber of the present invention is that it has such a leaf-like lamella arrangement in a proportion of 50% or more of the fiber cross-sectional area.
本発明のピツチ系炭素繊維は、断面構造におい
てこのようなリーフ状ラメラ配列を有するだけで
なく、Ｘ線回折より求められる配向角（OA）お
よび結晶サイズ（Lc）が特定範囲にあるという
第２の特徴を有する。すなわち、このピツチ系炭
素繊維は、繊維軸方向に整つた配向角を有すると
ともに小さな結晶サイズを有する。従来の光学異
方性（液晶）ピツチからの炭素繊維は、配向角を
整えやすい反面、結晶サイズが大きくなり、この
ためモジユラスは上りやすいものの、結晶界面に
欠陥が生じやすく、強伸度が低いものとなりがち
であつた。 The pitch-based carbon fiber of the present invention not only has such a leaf-like lamellar arrangement in its cross-sectional structure, but also has the second characteristic that the orientation angle (OA) and crystal size (Lc) determined by X-ray diffraction are within a specific range. It has the characteristics of That is, this pitch-based carbon fiber has a uniform orientation angle in the fiber axis direction and a small crystal size. Carbon fibers made from conventional optically anisotropic (liquid crystal) pitches are easy to adjust the orientation angle, but the crystal size is large, which makes it easy to increase modulus, but defects tend to occur at crystal interfaces, resulting in low strength and elongation. I tended to become a nuisance.
これに対し、本発明のピツチ系炭素繊維は、20
〜35°、好ましくは25〜35°という整つた配向角
（OA）を有し、且つ、15〜40Å、好ましくは18
〜35Åという微細な結晶サイズ（Lc）を有する。
このため、すでに述べたリーフ状ラメラ配列の効
果と相まつて、本発明の繊維は、引張強度550
Kg／mm2以上、モジユラス20T／mm2以上という従来
のピツチ系炭素繊維の物性からみて驚異的な物性
を示す。しかるに、リーフ状ラメラ配列を有する
ものでも配向角、結晶サイズがこの範囲外のもの
は、これほどの物性を示さない。 On the other hand, the pitch-based carbon fiber of the present invention has 20
It has a well-ordered orientation angle (OA) of ~35°, preferably 25-35°, and 15-40 Å, preferably 18
It has a fine crystal size (Lc) of ~35 Å.
Therefore, together with the effect of the leaf-like lamella arrangement mentioned above, the fiber of the present invention has a tensile strength of 550
Kg/mm 2 or more and modulus 20T/mm 2 or more, which are amazing physical properties compared to conventional pitch-based carbon fibers. However, even those with a leaf-like lamellar arrangement whose orientation angle and crystal size are outside this range do not exhibit such physical properties.
先に述べたリーフ状ラメラ配列の中心線が認め
られなくなる現象は、明確には説明できないが、
おそらく、本発明のピツチ系炭素繊維における結
晶サイズ（Lc）の微細化と何らかのかかわりを
持つものと推定される。 The phenomenon that the center line of the leaf-like lamellar arrangement mentioned above is no longer recognized cannot be clearly explained, but
It is presumed that this is probably somehow related to the refinement of the crystal size (Lc) in the pitch-based carbon fiber of the present invention.
本発明に係るピツチ系炭素繊維の断面形状（外
形）は、第１図に例示するような楕円形（長円
形）であることが必要である。この断面形状の繊
維はリーフ状ラメラ配列を最も大きい割合で含有
しやすい形状であるため繊維物性に良好な影響を
与えると考えられる。 The cross-sectional shape (outer shape) of the pitch-based carbon fiber according to the present invention needs to be an ellipse (ellipse) as illustrated in FIG. The fibers having this cross-sectional shape are considered to have a favorable influence on the physical properties of the fibers because they tend to contain the largest proportion of leaf-like lamellar arrangements.
このような特異な構造を有する本発明のピツチ
系炭素繊維は、光学異方性領域を50％以上、特に
80％以上含有する紡糸用ピツチを溶融した後、特
定の形状・寸法を有する紡糸孔から特定の条件下
に溶融紡糸し、これを不融化・焼成することによ
つて、容易に且つ安定に製造することができる。 The pitch-based carbon fiber of the present invention having such a unique structure has an optical anisotropy region of 50% or more, especially
After melting a spinning pitch containing 80% or more, it is melt-spun under specific conditions through a spinning hole with a specific shape and size, and then it is made infusible and fired to produce it easily and stably. can do.
次に、この製造方法について詳細に説明する。 Next, this manufacturing method will be explained in detail.
本発明のピツチ系炭素繊維を製造するための原
料としては、光学異方性領域を50％以上、好まし
くは80％以上、有する光学異方性ピツチを用い
る。光学異方性領域の割合が50％未満のピツチ
は、可紡性が悪く、均質且つ安定な物性のものが
得られないばかりでなく、本発明の繊維を得るこ
とが難しく、得られる繊維の物性も低いものとな
る。 As a raw material for producing the pitch-based carbon fiber of the present invention, optically anisotropic pitch having an optically anisotropic region of 50% or more, preferably 80% or more is used. Pitch with an optically anisotropic region ratio of less than 50% has poor spinnability, making it difficult to obtain homogeneous and stable physical properties, and making it difficult to obtain the fiber of the present invention. The physical properties are also poor.
紡糸用ピツチの融点は260〜320℃が好ましく、
更に好ましくは270〜310℃である。また紡糸用ピ
ツチのキノリン可溶部の割合は30重量％以上が好
ましく、特に30〜80重量％が好適である。これら
のパラメーターは原料ピツチによつて異なるが通
常は相関があり、光学異方性量が多い程、融点が
高く、キノリン可溶部の割合は低くなる。本発明
において好適に用いられる紡糸用ピツチの光学異
方性領域の割合（以下、光学異方性量という）が
多い程よく実質上100％のものが最適である。こ
のようなピツチは系が均質であり、可紡性にすぐ
れている。 The melting point of the pitch for spinning is preferably 260 to 320°C,
More preferably it is 270-310°C. The proportion of the quinoline-soluble portion in the spinning pitch is preferably 30% by weight or more, particularly preferably 30 to 80% by weight. Although these parameters vary depending on the raw material pitch, they are usually correlated; the greater the amount of optical anisotropy, the higher the melting point, and the lower the proportion of quinoline soluble portion. The ratio of the optically anisotropic region (hereinafter referred to as the amount of optical anisotropy) of the spinning pitch suitably used in the present invention is preferably as high as possible, and substantially 100% is optimal. Such pitches have a homogeneous system and are excellent in spinnability.
このような紡糸用ピツチの原料としては、例え
ばコールタール、コールタールピツチ、石炭液化
物のような石炭系重質油や、石油の常圧残留油、
減圧蒸留残油又はこれらの残油の熱処理によつて
副生するタールやピツチ、オイルサンド、ビチユ
ーメンのような石油系重質油を精製したものを用
い、これを熱処理、溶剤抽出、水素化処理等を組
合せて処理することによつて得られる。 Raw materials for such spinning pitches include, for example, coal tar, coal tar pitch, coal-based heavy oils such as coal liquefied products, atmospheric residual oil of petroleum,
Refined petroleum-based heavy oils such as tar, pitch, oil sand, and bitumen, which are by-products of vacuum distillation residual oil or heat treatment of these residual oils, are used and are subjected to heat treatment, solvent extraction, and hydrogenation treatment. It can be obtained by processing in combination.
本発明のピツチ系炭素繊維を製造するには、前
述の如き紡糸用ピツチを溶融紡糸する際に、繊維
軸方向の配向を促進させ、且つ、繊維断面方向の
配向を制御することが大切である。このことを実
現する上で、紡糸口金の紡糸孔（ノズル）形状・
寸法が特に重要な役割を果す。 In order to produce the pitch-based carbon fiber of the present invention, it is important to promote orientation in the fiber axis direction and to control orientation in the cross-sectional direction of the fibers when melt-spinning the spinning pitch as described above. . In order to achieve this, the shape of the spinning hole (nozzle) of the spinneret,
Dimensions play a particularly important role.
すなわち、前述の如き紡糸用ピツチの溶融物を
次式（）（）を同時に満足する単一スリツト
部を有する紡糸孔を通じて溶融紡糸することが必
要である。 That is, it is necessary to melt-spun the melt in the spinning pitch as described above through a spinning hole having a single slit portion that simultaneously satisfies the following formulas () and ().
かかる紡糸孔としては、該紡糸孔における中心
線距離をLnとし、それに対応するぬれぶち幅を
Wnとしたとき（但しｎ＝１〜10の整数）、Lnの
少なくとも１つが、
Ln＜5.0（mm） ……（）
1.5＜Ln／Wn＜20 ……（）
を同時に満足するものを使用する。 For such a spinning hole, the centerline distance in the spinning hole is Ln, and the corresponding wetting edge width is
When Wn (n = integer from 1 to 10), at least one of Ln satisfies Ln<5.0 (mm) ...() 1.5<Ln/Wn<20 ...() .
かかる紡糸孔としては、直線状又は曲線状の単
一スリツトからなる紡糸孔が用いられ、これら
は、いずれも優れた物性を発現し得るが、なかで
も直線状の単一スリツトよりなるものが好まし
い。 As such a spinning hole, a spinning hole consisting of a straight or curved single slit is used, and any of these can exhibit excellent physical properties, but among them, a spinning hole consisting of a straight single slit is preferable. .
本発明者らの研究によれば、単一スリツトの場
合、なかでも、
３＜Ln／Wn＜15（但しｎ＝１）
を満足するものが好ましいリーフ状ラメラ配列を
形成し易く、特に好適であることが確認された。
かかる単一の直線状スリツトよりなる、一文字形
紡糸孔においては、スリツトの両端部を滑らかな
曲線により形成するのが好ましい。第２図には、
かかる好適な紡糸孔の形状の一例を示す。 According to the research conducted by the present inventors, in the case of a single slit, one that satisfies 3<Ln/Wn<15 (however, n=1) is particularly preferable because it is easy to form a leaf-like lamellar arrangement. It was confirmed that there is.
In such a single-character shaped spinning hole consisting of a single linear slit, both ends of the slit are preferably formed with smooth curves. In Figure 2,
An example of such a suitable spinning hole shape is shown.
これに対し、従来のピツチ繊維の溶融紡糸に使
用されている円形紡糸孔を有する紡糸口金を用い
た場合や、Ln／Wnが前記範囲外の異形紡糸孔
（例えば正三角形、正多角形等の紡糸孔）を有す
る紡糸口金を用いた場合には、炭素繊維の断面が
リーフ状ラメラ配列となり得ず、アジアル構造又
はランダム構造となつてしまう。 On the other hand, when a spinneret with a circular spinning hole, which is used in the conventional melt spinning of pitch fibers, is used, or when a spinneret with an irregularly shaped spinning hole with Ln/Wn outside the above range (for example, a regular triangle, a regular polygon, etc.) is used. When a spinneret having spinning holes (spinning holes) is used, the cross section of the carbon fibers cannot have a leaf-like lamellar arrangement, but instead has an asian structure or a random structure.
このような特殊な単一スリツト状紡糸孔の使用
は、軸方向の配向を助け断面方向の配向を制御す
るのに有効であるが、単に、かかる紡糸孔を用い
るだけでは、配向角（OA）と結晶サイズ（Lc）
を上記範囲内に制御することは困難である。この
ため、断面方向の配向を制御し結晶の生長を抑え
る目的で、紡糸口金板の上流側に整流板を設置す
ることが有効である。このような整流板として
は、流線に対し垂直な断面形状が、平行スリツ
ト、格子状、微小円の集合形状等任意のものを使
用できるが、整流板により一つの溶融ピツチ流を
細かく分割して形成された個々の流線が互いに交
絡しない形状である必要がある。流線が交絡する
場合、それにより流れに乱れが生じ、繊維軸方向
の配向が阻害されるため好ましくない。 Although the use of such a special single slit spinning hole is effective in assisting the axial orientation and controlling the cross-sectional orientation, simply using such a spinning hole does not increase the orientation angle (OA). and crystal size (Lc)
It is difficult to control within the above range. Therefore, it is effective to install a current plate on the upstream side of the spinneret plate in order to control the orientation in the cross-sectional direction and suppress the growth of crystals. As such a current plate, any cross-sectional shape perpendicular to the streamlines can be used, such as parallel slits, a lattice shape, or a collection of microcircles. It is necessary that the individual streamlines formed by the process are shaped so that they do not intertwine with each other. If the streamlines are intertwined, this is not preferable because it causes turbulence in the flow and obstructs the orientation of the fiber axis.
また、断面方向の配向の制御を確実にするため
に別の方法を採用することもできる。それは、吐
出速度を通常よりも低く抑えることであり、これ
により断面方向の巨大な配向の形成を抑制でき
る。このような吐出速度としては、紡糸孔で
1m／分以下が好ましい。 Other methods may also be employed to ensure control of cross-sectional orientation. The purpose is to keep the ejection speed lower than usual, thereby suppressing the formation of a huge orientation in the cross-sectional direction. Such a discharge speed is
1 m/min or less is preferable.
以上のように、本発明のピツチ系炭素繊維は、
光学異方性ピツチの溶融紡糸に際し、上述した特
殊な単一スリツト紡糸孔を有する口金を使用する
ことを中心とし、これに整流板の使用および／又
は吐出速度条件を組合せることにより、安定に製
造できる。 As mentioned above, the pitch-based carbon fiber of the present invention is
When melt-spinning optically anisotropic pitch, we mainly use the above-mentioned special spinneret with a single slit spinning hole, and by combining this with the use of a rectifying plate and/or the discharge speed conditions, we can achieve stability. Can be manufactured.
紡糸温度は、融点より40〜100℃高い温度を採
用することができるが、優れた物性を得るために
は380℃を越える温度は避けるべきである。この
ような温度以上では炭化反応が開始され、これに
伴なうガス発生が、繊維物性の低下にとつて無視
できない影響を持つからである。 The spinning temperature can be 40 to 100°C higher than the melting point, but temperatures exceeding 380°C should be avoided in order to obtain excellent physical properties. This is because at temperatures above such a temperature, a carbonization reaction is initiated, and the accompanying gas generation has a non-negligible effect on the deterioration of fiber properties.
前述のごとき紡糸孔を用い、且つ前述のごとき
特殊な条件で光学異方性ピツチを溶融紡糸する
と、何故微細なリーフ状ラメラ配列を生ずるかは
未だ充分解明されておらず、今後の詳細な検討を
待たねばならないが、およそ次のように考えられ
る。 It is still not fully understood why a fine leaf-like lamella arrangement is produced when optically anisotropic pitch is melt-spun using the above-mentioned spinning holes and under the above-mentioned special conditions, and this will require detailed investigation in the future. We will have to wait until then, but it can be thought of as follows.
光学異方性を有するピツチ（液晶ピツチ）の配
向単位は２次元の平板状（これに対し合繊用ポリ
マーは１次元線状）と推定され、このような平板
状配向単位は、紡糸時に流動軸（押出し）方向に
配列すると同時に紡糸口金のノズル（紡糸孔）内
の等速度線に対し直角方向に配列し易い。円形ノ
ズル内の等速度線は同心円状であり、これに直角
に配列するため、得られるピツチ繊維の断面内で
はラジアル状に配列する。このため不融化・焼成
段階で、分子面間隔の収縮時に応力歪みが生じ易
くクラツクを生じる。 The alignment unit of pitch (liquid crystal pitch) having optical anisotropy is estimated to be two-dimensional plate-like (in contrast, polymers for synthetic fibers are one-dimensional linear), and such a plate-shaped alignment unit is not aligned with the flow axis during spinning. It is easy to arrange them in the (extrusion) direction and at the same time in the direction perpendicular to the constant velocity line in the nozzle (spinning hole) of the spinneret. The constant velocity lines in the circular nozzle are concentric circles and are arranged at right angles thereto, so that they are arranged radially in the cross section of the pitch fibers obtained. For this reason, during the infusibility and sintering stages, stress distortion is likely to occur when the molecular spacing contracts, resulting in cracks.
これに対し、前述の寸法を有するスリツト部を
もつノズル内の等速度線が該スリツト部ではＵ字
状となり、これに直角に配列するとピツチの配向
単位は繊維断面内で第１図の如くリーフ状に配列
する。この配列は、平板状の配向単位が繊維断面
では並列に並んでいる状態であり、不融化・焼成
段階での面間隔の収縮時に応力歪みを吸収し易い
配列であるため、不融化・焼成時に配向単位が微
細に充填される等の理由により、クラツク等の欠
陥の発生が非常に少なくなり、すぐれた物性が発
現すると考えられる。そして、この際に、整流板
の使用又は吐出条件の選定により、繊維軸方向に
整つた配向となるとともに結晶サイズが小さくな
つて、ラメラが微細化するため、この効果が助長
され、一段とすぐれた物性が発現する。 On the other hand, the uniform velocity line in a nozzle with a slit section having the above-mentioned dimensions becomes U-shaped at the slit section, and when arranged at right angles to this, the pitch orientation unit becomes a leaf within the fiber cross section as shown in Figure 1. Arrange in a shape. In this arrangement, the flat orientation units are arranged in parallel in the cross section of the fiber, and because it is an arrangement that easily absorbs stress strain when the interplanar spacing shrinks during the infusibility and sintering stages, It is thought that due to the finely packed orientation units, the occurrence of defects such as cracks is extremely reduced and excellent physical properties are exhibited. At this time, by using a rectifying plate or selecting discharge conditions, the fibers are oriented in the axial direction, the crystal size is reduced, and the lamella becomes finer, which promotes this effect and provides even better results. Physical properties are revealed.
このように溶融紡糸されたピツチ繊維は、ドラ
フト率30以上、好まくは50以上で引き取ることが
好適である。ここでドラフト率とは次式で定義さ
れる値であり、この値が大きいことは紡糸時の変
形速度が大きく、他の条件が同一の場合はドラフ
ト率が大きい程、急冷効果が大となる。 The pitch fibers melt-spun as described above are preferably taken at a draft rate of 30 or more, preferably 50 or more. Here, the draft rate is a value defined by the following formula, and the larger this value is, the higher the deformation speed during spinning is.If other conditions are the same, the larger the draft rate, the greater the quenching effect. .
ドラフト率＝紡糸引取速度／紡糸口金からの吐出線速
度
ドラフト率30以上、特に50以上で引き取ると、
引続く不融化・焼成処理により、好適な物性を発
現し易いので好ましい。 Draft rate = spinning take-off speed / linear velocity of discharge from the spinneret If the draft rate is over 30, especially over 50,
This is preferable because suitable physical properties can be easily developed through the subsequent infusibility and sintering treatment.
紡糸引取速度は、前述の紡糸条件では1000m／
分以上の高速でもきわめて円滑に紡糸することが
できるが、通常100〜2000m／分の範囲が好まし
く用いられる。 The spinning take-off speed is 1000 m/min under the above spinning conditions.
Although spinning can be carried out very smoothly even at high speeds of 100 to 2000 m/min or more, the preferred range is usually 100 to 2000 m/min.
上述のようにして得られたピツチ繊維は、次い
で、酸素の存在下に不融化処理される。 The pitch fibers obtained as described above are then treated to be infusible in the presence of oxygen.
この不融化処理工程は生産性および繊維物性を
左右する重要な工程で、できるだけ短時間で実施
することが好ましい。このため、不融化温度、昇
温速度、雰囲気ガス等を紡糸ピツチ繊維に対し適
宜選択する必要があるが、本発明におけるピツチ
繊維は、高融点の光学異方性ピツチを用いている
こと、繊維断面形状が楕円形で単位断面積当りの
表面積が大きいこと等により、通常の円形断面か
ら紡糸された従来のピツチ繊維よりも処理時間を
短縮することが可能である。また、この工程にお
いては、融着を防止するため無機系微粉末等の融
着防止剤を用いてもよい。 This infusibility treatment step is an important step that affects productivity and fiber properties, and is preferably carried out in as short a time as possible. For this reason, it is necessary to appropriately select the infusibility temperature, heating rate, atmospheric gas, etc. for the spun pitch fiber, but the pitch fiber in the present invention uses optically anisotropic pitch with a high melting point, Because the cross-sectional shape is elliptical and the surface area per unit cross-sectional area is large, the processing time can be reduced compared to conventional pitch fibers spun from a normal circular cross-section. Further, in this step, an anti-fusing agent such as an inorganic fine powder may be used to prevent fusing.
さらに、不融化処理の短時間化のために、不融
化促進剤として、沃素、塩素等も好適に用いられ
る。 Furthermore, in order to shorten the time of the infusibility treatment, iodine, chlorine, etc. are preferably used as the infusibility accelerator.
このように不融化処理した繊維は、次に、不活
性ガス中において通常1000〜1500℃、好ましくは
1300℃付近の温度で焼成することにより本発明の
ピツチ系炭素繊維を得ることができる。このもの
をそのまま使用してもよいが、さらに約3000℃程
度まで加熱して黒鉛化させてから使用することも
できる。 The fibers thus infusible are then heated in an inert gas at usually 1000 to 1500°C, preferably
The pitch-based carbon fiber of the present invention can be obtained by firing at a temperature around 1300°C. This product may be used as it is, but it can also be used after being further heated to about 3000°C to graphitize it.
［発明の効果］
前述の如き本発明のピツチ系炭素繊維は、その
断面構造がリーフ状ラメラ配列を有し、且つ上述
のように結晶の配向及びサイズが特定範囲内にあ
るために、クラツクがほぼ完全に防止され、さら
に不融化・焼成段階での収縮が円滑におこなわれ
るため、後述の実施例に示す如く、強度、モジユ
ラスが飛躍的に増大し、PAN系炭素繊維の物性
を凌駕するものとなる。したがつて、本発明のピ
ツチ系炭素繊維は複合材の補強繊維としてきわめ
て有用である。[Effects of the Invention] The pitch-based carbon fiber of the present invention as described above has a leaf-like lamellar arrangement in its cross-sectional structure, and the orientation and size of the crystals are within a specific range as described above, so that cracks do not occur. Since shrinkage is almost completely prevented and shrinkage occurs smoothly during the infusibility and firing stages, the strength and modulus are dramatically increased, and the physical properties surpass those of PAN-based carbon fibers, as shown in the examples below. becomes. Therefore, the pitch-based carbon fiber of the present invention is extremely useful as a reinforcing fiber for composite materials.
［各指標の測定法］
次に本発明における紡糸用ピツチおよび繊維特
性を表わす各指標の測定法について説明する。[Method for Measuring Each Index] Next, a method for measuring each index representing the spinning pitch and fiber properties in the present invention will be explained.
(a) 紡糸用ピツチの融点
パーキンエルマー社製DSC−1D型を用い、ア
ルミニウム製セル（内径5m／ｍ）に100メツシユ
以下に粉砕したピツチ微粉末10mgを入れ、上から
押えた後、窒素雰囲気中、昇温速度10℃／分で
400℃近くまで昇温しつつ測定し、DSCのチヤー
トにおける融点を示す吸熱ピークをもつて紡糸用
ピツチの融点とする。(a) Melting point of pitch for spinning Using a PerkinElmer DSC-1D model, 10 mg of pitch fine powder crushed to 100 meshes or less was placed in an aluminum cell (inner diameter 5 m/m), pressed from above, and placed in a nitrogen atmosphere. Medium, heating rate 10℃/min
Measurement is performed while raising the temperature to nearly 400°C, and the endothermic peak that indicates the melting point in the DSC chart is determined as the melting point of the spinning pitch.
(b) 紡糸用ピツチの光学異方性量
反射型偏光顕微鏡を用いて紡糸ピツチの偏光顕
微鏡写真を任意に５枚撮り、画像解析処理装置を
用いて等方性領域の面積分率（％）を算出し、こ
のものの平均値を光学異方性量とする。(b) Amount of optical anisotropy of the spinning pitch Five arbitrary polarized micrographs of the spinning pitch were taken using a reflective polarizing microscope, and the area fraction (%) of the isotropic region was calculated using an image analysis processing device. However, the average value of these values is taken as the amount of optical anisotropy.
(c) 炭素繊維の物性
炭素繊維の繊維径（単糸径）、引張強度、伸度、
モジユラスは、JIS Ｒ−7601「炭素繊維試験方法」
に従つて測定する。なお繊維径の測定は、円形断
面繊維についてはレーザーによる測定を行い、非
円形断面繊維については走査型電子顕微鏡写真よ
りｎ＝15の断面積の平均値を算出する。なお、実
施例等においては繊維径を相当する断面積を有す
る円に換算したときの直径で表示した。(c) Physical properties of carbon fiber Carbon fiber fiber diameter (single fiber diameter), tensile strength, elongation,
Modulus is JIS R-7601 "Carbon fiber test method"
Measure according to. The fiber diameter is measured using a laser for fibers with a circular cross section, and for fibers with a non-circular cross section, the average value of the cross-sectional area of n=15 is calculated from scanning electron micrographs. In addition, in Examples etc., the fiber diameter is expressed as a diameter when converted into a circle having a corresponding cross-sectional area.
(d) リーフ状ラメラ配列の分率
炭素繊維断面の走査型電子顕微鏡写真より、断
面積当りのリーフ状ラメラ配列部分の面積比率で
表わす。(d) Fraction of leaf-like lamella arrangement Based on a scanning electron micrograph of a cross section of carbon fiber, it is expressed as the area ratio of the leaf-like lamella arrangement part per cross-sectional area.
(e) ミクロ構造パラメーター
配向角（OA）、結晶サイズ（Lc）は、ともに
広角Ｘ線回折により求められる繊維のミクロ（微
細）構造を表わすパラメーターである。配向角
（OA）は、結晶の繊維軸方向に対する配向の程
度を示すもので、この角度が小さい程配向が進ん
でいることを意味する。結晶サイズ（Lc）は炭
素微結晶の見掛け積層高さを表わす。(e) Microstructure parameters The orientation angle (OA) and the crystal size (Lc) are both parameters representing the microstructure of the fiber determined by wide-angle X-ray diffraction. The orientation angle (OA) indicates the degree of orientation of the crystal with respect to the fiber axis direction, and the smaller this angle, the more advanced the orientation is. Crystal size (Lc) represents the apparent stacking height of carbon microcrystals.
炭素繊維においては、これらの値が焼成温度と
ともに変化することが知られているが、焼成温度
を定めた場合、各種炭素繊維は、その製法により
定まる一定の構造パラメーターを示す。 It is known that these values of carbon fibers change with the firing temperature, but when the firing temperature is determined, each type of carbon fiber exhibits certain structural parameters determined by its manufacturing method.
本発明で特定した配向角（OA）、結晶サイズ
（Lc）は、全て1300℃で焼成した炭素繊維の構造
パラメーターとして表示され、Ｘ線回折は、繊維
を一束にし、Ｘ線ビームに垂直に装着し、方位角
2θを０〜90°スキヤンし、（002）帯（約26°近傍）
の強度分布の最大値の1/2の位置における全幅
（半価幅）Ｂ、及び方位角2θより下記式でLcが算
出される。 The orientation angle (OA) and crystal size (Lc) specified in this invention are all displayed as structural parameters of carbon fibers fired at 1300℃, and X-ray diffraction is performed by arranging the fibers into a bundle and perpendicular to the X-ray beam. Mounted and azimuth
Scan 2θ from 0 to 90° and find the (002) band (approximately 26°)
Lc is calculated by the following formula from the full width (half width) B at the position of 1/2 of the maximum value of the intensity distribution and the azimuth 2θ.
Lc＝Kλ／（Ｂ−ｂ）cosθ
（ここでＫ＝0.9，ｂ＝0.0017rad，λ＝1.5418
Å）
また、（002）帯の強度分布の最大値を示す方位
角の位置において繊維束をＸ線ビームの垂直面内
において180℃回転することにより、（002）帯の
強度分布をとり、強度最大値の1/2の点における
半価幅を配向角（OA）とする。 Lc=Kλ/(B-b) cosθ (where K=0.9, b=0.0017rad, λ=1.5418
Å) In addition, by rotating the fiber bundle by 180 degrees in the vertical plane of the X-ray beam at the azimuth angle position that indicates the maximum value of the intensity distribution of the (002) band, the intensity distribution of the (002) band is obtained. The half width at half the maximum value is defined as the orientation angle (OA).
［実施例］
以下、実施例をあげて本発明をさらに詳細に説
明するが、本発明はこれらの実施例によつて何等
限定されるものではない。[Examples] Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples in any way.
実施例 １
市販のコールタールピツチを原料とし、特開昭
59−53717号公報に記載の方法に準じ、全面流れ
構造で光学異方性量を92％有し、キノリン不溶部
35.4％、融点286℃の紡糸用ピツチを調製した。Example 1 Using commercially available coal tar pitch as a raw material,
According to the method described in Publication No. 59-53717, it has a full-surface flow structure and an optical anisotropy of 92%, and a quinoline-insoluble part.
A spinning pitch of 35.4% and a melting point of 286°C was prepared.
該紡糸用ピツチを加熱ヒーターを備えた定量フ
イーダーに仕込み、溶融脱泡後、別に設けた加熱
ゾーンを経て、スリツト幅60μm、中心線距離
540μmの直線状単一スリツト紡糸孔を有する口金
を用いて、紡糸を行つた。 The spinning pitch is charged into a metering feeder equipped with a heating heater, and after melting and degassing, it passes through a separately prepared heating zone to form a slit with a width of 60 μm and a center line distance.
Spinning was carried out using a spindle with a 540 μm linear single slit spinning hole.
この場合のフイーダー吐出量は0.032ml／分／
孔、吐出速度は1m／分、フイーダー部温度
（T1）＝320℃、加熱ゾーン温度（T2）＝320℃と
し、口金温度（T3）＝340℃となし、引取速度
600m／分で巻き取つた。 In this case, the feeder discharge amount is 0.032ml/min/
The hole and discharge speed are 1 m/min, the feeder temperature (T 1 ) = 320℃, the heating zone temperature (T 2 ) = 320℃, the mouth temperature (T 3 ) = 340℃, and the take-up speed.
It was wound at a speed of 600m/min.
このピツチ繊維をシリカ微粉末を融着防止剤と
して塗布した後、乾燥空気中にて10℃／分の昇温
速度で200℃から300℃まで昇温加熱し、300℃で
30分間保持し不融化させた。 After applying fine silica powder as an anti-fusing agent to this pitch fiber, it was heated in dry air at a heating rate of 10°C/min from 200°C to 300°C.
It was held for 30 minutes to make it insoluble.
次いで、窒素雰囲気中にて500℃／分の昇温速
度で1300℃まで昇温加熱し、５分間保持すること
により焼成を行い、炭素繊維とした。 Next, the mixture was heated to 1300° C. at a heating rate of 500° C./min in a nitrogen atmosphere, and fired by holding for 5 minutes to obtain carbon fibers.
得られた繊維の断面形状は楕円形であり、リー
フ状ラメラ分率は98％であつた。この炭素繊維を
Ｘ線回折にかけたところ、OA＝31.92°，Lc＝
20.12Åであり、物性特定の結果、円換算糸径＝
6.47μm、強度＝604Kg／mm2、伸度＝2.23％、モジ
ユラス＝27.2T／mm2の極めて優れた値を示した。 The cross-sectional shape of the obtained fiber was elliptical, and the leaf-like lamella fraction was 98%. When this carbon fiber was subjected to X-ray diffraction, OA = 31.92°, Lc =
20.12 Å, and as a result of physical property identification, the circular equivalent thread diameter =
It showed extremely excellent values of 6.47 μm, strength = 604 Kg/mm 2 , elongation = 2.23%, and modulus = 27.2 T/mm 2 .
比較例 １
光学異方性量を88％有し、キノリン不溶部39
％、融点274℃の紡糸用ピツチを定量フイーダー
に仕込み、フイーダー吐出量0.06ml／分／孔、吐
出速度1.9m／分、フイーダー温度（T1）＝320℃、
加熱ゾーン温度（T2）＝320℃、口金温度（3）＝
335℃、引取速度800m／分で実施例１と同じ単一
スリツト紡糸孔を有する口金を用いて紡糸し、得
られたピツチ繊維を乾燥空気中で10℃／分の昇温
速度で200℃から300℃まで昇温加熱し、300℃で
30分保持することにより不融化処理を施した後、
窒素雰囲気中にて500℃／分の昇温速度で1300℃
まで昇温加熱し、５分間保持することによりリー
フ状ラメラ分率100％のピツチ系炭素繊維を製造
した。Comparative Example 1 Optical anisotropy of 88%, quinoline insoluble portion 39
%, a spinning pitch with a melting point of 274°C was placed in a metering feeder, feeder discharge amount was 0.06ml/min/hole, discharge speed was 1.9m/min, feeder temperature (T 1 ) = 320°C,
Heating zone temperature (T 2 ) = 320℃, base temperature ( 3 ) =
The yarn was spun at 335°C at a take-up speed of 800 m/min using the spindle having the same single slit spinning hole as in Example 1, and the resulting pitch fiber was spun from 200°C at a heating rate of 10°C/min in dry air. Heat up to 300℃, and at 300℃
After being infusible by holding for 30 minutes,
1300℃ at a heating rate of 500℃/min in nitrogen atmosphere
Pitch-based carbon fibers with a leaf-like lamella fraction of 100% were produced by heating the mixture to 100% and holding it for 5 minutes.
該炭素繊維のOA，Lcを測定した結果、OA＝
29.8°、Lc＝43.5Åであり、本発明の炭素繊維と比
較し大きなLcを有していた。 As a result of measuring the OA and Lc of the carbon fiber, OA=
29.8°, Lc=43.5 Å, and had a larger Lc than the carbon fiber of the present invention.
この炭素繊維の物性は、引張強度＝462Kg／mm2、
伸度＝1.83％、モジユラス＝25.3T／mm2であり、
リーフ状ラメラ配列による物性の向上は認められ
るものの、本発明の炭素繊維と比べ引張強度が低
いものであつた。 The physical properties of this carbon fiber are tensile strength = 462Kg/mm 2 ,
Elongation = 1.83%, modulus = 25.3T/ mm2 ,
Although the physical properties were improved due to the leaf-like lamella arrangement, the tensile strength was lower than that of the carbon fiber of the present invention.
第１図は、本発明に係るピツチ系炭素繊維の断
面構造を模式的に示す拡大図である。第２図は、
本発明に係るピツチ系炭素繊維を製造する場合に
用いられる紡糸孔形状の一例を示す紡糸孔断面の
拡大である。
Ln……中心線距離、Wn……ぬれぶち幅。
FIG. 1 is an enlarged view schematically showing the cross-sectional structure of pitch carbon fiber according to the present invention. Figure 2 shows
1 is an enlarged view of a cross-section of a spinning hole showing an example of the shape of a spinning hole used when manufacturing pitch-based carbon fibers according to the present invention. Ln...Center line distance, Wn...Wetting edge width.
Claims (1)
繊維断面の50％以上にリーフ状ラメラ配列を有
し、且つ、Ｘ線回折より求められる配向角
（OA）が20〜35°、結晶サイズ（Lc）が15〜40Å
のミクロ構造を有し、しかも引張強度が少なくと
も550Kg／mm2、モジユラスが少なくとも20T／mm2
を示すことを特徴とするピツチ系炭素繊維。1 The cross-sectional shape of the fiber is substantially elliptical,
It has a leaf-like lamellar arrangement in 50% or more of the fiber cross section, and the orientation angle (OA) determined by X-ray diffraction is 20 to 35° and the crystal size (Lc) is 15 to 40 Å.
microstructure with a tensile strength of at least 550 Kg/mm 2 and a modulus of at least 20 T/mm 2
A pitch-based carbon fiber characterized by exhibiting the following characteristics.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23530684A JPS61113828A (en) | 1984-11-09 | 1984-11-09 | Pitch-based carbon fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23530684A JPS61113828A (en) | 1984-11-09 | 1984-11-09 | Pitch-based carbon fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS61113828A JPS61113828A (en) | 1986-05-31 |
| JPH0561367B2 true JPH0561367B2 (en) | 1993-09-06 |
Family
ID=16984158
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP23530684A Granted JPS61113828A (en) | 1984-11-09 | 1984-11-09 | Pitch-based carbon fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS61113828A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62170526A (en) * | 1986-01-22 | 1987-07-27 | Osaka Gas Co Ltd | Production of carbon fiber having elliptic cross-section |
| US4859382A (en) * | 1986-01-22 | 1989-08-22 | Osaka Gas Company Limited | Process for preparing carbon fibers elliptical in section |
| US4915926A (en) * | 1988-02-22 | 1990-04-10 | E. I. Dupont De Nemours And Company | Balanced ultra-high modulus and high tensile strength carbon fibers |
| US5437927A (en) * | 1989-02-16 | 1995-08-01 | Conoco Inc. | Pitch carbon fiber spinning process |
| US5202072A (en) * | 1989-02-16 | 1993-04-13 | E. I. Du Pont De Nemours And Company | Pitch carbon fiber spinning process |
| TW459075B (en) * | 1996-05-24 | 2001-10-11 | Toray Ind Co Ltd | Carbon fiber, acrylic fiber and preparation thereof |
| CN102317516A (en) | 2008-12-19 | 2012-01-11 | 帝人株式会社 | Carbon fibers and method for producing the same |
-
1984
- 1984-11-09 JP JP23530684A patent/JPS61113828A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS61113828A (en) | 1986-05-31 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4628001A (en) | Pitch-based carbon or graphite fiber and process for preparation thereof | |
| JPS6246644B2 (en) | ||
| JPH0370012B2 (en) | ||
| JPH026624A (en) | Carbon fiber well-balanced in ultrahigh modulus and high tensile force | |
| US4913889A (en) | High strength high modulus carbon fibers | |
| US5536486A (en) | Carbon fibers and non-woven fabrics | |
| JPH0561367B2 (en) | ||
| JPH0790725A (en) | Milled meso-phase pitch carbon fiber and production thereof | |
| JP2652932B2 (en) | Flexible pitch carbon fiber with high elastic modulus | |
| JPS5953717A (en) | Pitch-based carbon fiber having high strength and modulus and its manufacture | |
| JPH0133572B2 (en) | ||
| TW201033419A (en) | Carbon fibers and method for producing the same | |
| JPS616316A (en) | Graphite fiber | |
| JPH0370011B2 (en) | ||
| JPH0415289B2 (en) | ||
| JPH0545685B2 (en) | ||
| JPH0781211B2 (en) | Carbon fiber manufacturing method | |
| JPH0380888B2 (en) | ||
| JPH0144805B2 (en) | ||
| JPS5936726A (en) | Precursor pitch fiber for carbon fiber | |
| JPH0788604B2 (en) | Method for manufacturing pitch-based carbon fiber | |
| JP2722270B2 (en) | Carbon fiber and non-woven fabric containing it as a main component | |
| JPS6147825A (en) | Pitch-based carbon fiber | |
| JPS62177222A (en) | Production of pitch based carbon fiber | |
| JPS626919A (en) | Pitch-based carbon fiber having high strength and high modulus |