JPH06173122A - High-elongation carbon fiber and its production - Google Patents
High-elongation carbon fiber and its productionInfo
- Publication number
- JPH06173122A JPH06173122A JP34358692A JP34358692A JPH06173122A JP H06173122 A JPH06173122 A JP H06173122A JP 34358692 A JP34358692 A JP 34358692A JP 34358692 A JP34358692 A JP 34358692A JP H06173122 A JPH06173122 A JP H06173122A
- Authority
- JP
- Japan
- Prior art keywords
- carbon fiber
- heat treatment
- elongation
- filament
- temperature
- 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
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、各種複合材料の補強材
として好適な、非晶質構造を有する高伸度炭素繊維及び
その製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high elongation carbon fiber having an amorphous structure, which is suitable as a reinforcing material for various composite materials, and a method for producing the same.
【０００２】[0002]
【従来の技術】炭素繊維は、高い強度と優れた耐蝕性、
耐薬品性に加えて、高い導電性や熱伝導性、自己潤滑性
など優れた特性を有する繊維であり、多種多様な分野で
広範囲に使用されている材料である。この炭素繊維を補
強材として使用したプラスチック、ゴム、セメント系材
料などの繊維強化複合材料は各種工業用材料として利用
価値が高く、大量に使用されている。これらの繊維強化
複合材料には、強度の信頼性を高めるため、ある程度以
上のじん性が要求されるので、複合材料の補強材として
用いる繊維としては、できるだけ高い伸度を有するもの
が好ましい。高い伸度を有する材料は吸収エネルギ−が
大きいことからバネ材等の緩衝材の補強用フィラ−とし
て有用である。また、製織時の繊維の屈曲に対に対する
抵抗力が強いので製織時の糸切れや毛羽の発生を抑制す
ることができる。2. Description of the Related Art Carbon fiber has high strength and excellent corrosion resistance,
In addition to chemical resistance, the fiber has excellent properties such as high electrical conductivity, thermal conductivity, and self-lubricating property, and is a material widely used in various fields. Fiber-reinforced composite materials such as plastics, rubbers, and cement-based materials that use this carbon fiber as a reinforcing material have high utility value as various industrial materials and are used in large quantities. Since these fiber-reinforced composite materials are required to have a certain degree of toughness in order to increase the reliability of strength, it is preferable that the fibers used as the reinforcing material of the composite material have as high elongation as possible. A material having a high elongation has a large absorbed energy and is useful as a filler for reinforcing a cushioning material such as a spring material. Further, since the resistance against the bending of the fibers during weaving is strong, it is possible to suppress the occurrence of yarn breakage and fluff during weaving.
【０００３】現在、市販されている炭素繊維は大部分ポ
リアクリロニトリル（ＰＡＮ）あるいはピッチを原料と
するものであり、それぞれの使用目的に応じて多種多様
のグレ−ドのものが製造されている。これらの炭素繊維
には、大きく分けて引張強度１００ｋｇ／ｍｍ2、弾性
率１０ｔｏｎ／ｍｍ2程度の汎用グレ−ドと引張強度や
弾性率の高い高性能グレ−ドとがあり、高性能グレ−ド
は更に引張強度３００〜８００ｋｇ／ｍｍ2、弾性率２
５ｔｏｎ／ｍｍ2程度の高強度グレ−ドと引張強度３０
０ｋｇ／ｍｍ2、弾性率３５〜９０ｔｏｎ／ｍｍ2程度の
高弾性率グレ−ドとに大別されている。各種複合材料を
製造しようとする場合には、これらの炭素繊維の中から
適当な物性値のものを選んで使用しているが、一般に炭
素繊維は、その優れた特性値に比較して伸度が小さいと
いう特徴を有している。At present, most commercially available carbon fibers are made of polyacrylonitrile (PAN) or pitch as raw materials, and various grades of carbon fibers are manufactured according to their intended use. These carbon fibers are roughly classified into a general-purpose grade having a tensile strength of 100 kg / mm 2 and an elastic modulus of about 10 ton / mm 2, and a high-performance grade having a high tensile strength and elastic modulus. The tensile strength is 300 to 800 kg / mm 2 , and the elastic modulus is 2
High strength grade of about 5 ton / mm 2 and tensile strength of 30
It is roughly classified into a high elastic modulus grade of 0 kg / mm 2 and an elastic modulus of about 35 to 90 ton / mm 2 . When manufacturing various composite materials, those with suitable physical property values are selected from these carbon fibers and used, but carbon fibers generally have higher elongation than their excellent characteristic values. Has the characteristic of being small.
【０００４】前記のように、複合材料の補強用繊維とし
ては、できるだけ高い伸度を有するものが好ましいの
で、伸度の高い炭素繊維を得る方法も試みられている。
炭素繊維の伸度を高める方法の一つは、紡糸原料の濾過
精度を高めて、不純物の混入を防ぎ、更に耐炎化炉や炭
化炉内での浮遊粉塵を除去することによって繊維中の欠
陥を少なくする方法であるが、一般に紡糸原料の濾過精
製は難しく、この方法で達成できる炭素繊維の伸度は、
ＰＡＮ系の炭素繊維で３．０％、ピッチ系の炭素繊維で
は２．４％程度が限界とみられている。また、炭素繊維
の特性の一つにその結晶構造があるが、結晶の発達した
異方性のものに比較して、等方性のものの方が化学的に
安定であり、また圧縮強度も高い。更に製織時や繊維の
摩擦によるフィブリル化を抑制し、かつ繊維の圧縮強度
を高めるためにも等方性の結晶構造を有する繊維が好ま
しい場合がある。炭素繊維の結晶構造は、炭化時の加熱
処理温度によって変わるが、従来のＰＡＮ系あるいは高
弾性ピッチ系繊維の場合には、２０００℃程度までの温
度でほとんどが異方性となってしまい、２０００℃以上
の温度で熱処理してもＸ線的な等方性を維持している炭
素繊維は知られていない。As described above, as the reinforcing fibers of the composite material, those having as high elongation as possible are preferable. Therefore, a method of obtaining carbon fibers having high elongation has also been attempted.
One of the methods to increase the elongation of carbon fiber is to improve the filtration accuracy of the spinning raw material, prevent the inclusion of impurities, and further remove the floating dust in the flameproofing furnace and the carbonization furnace to eliminate defects in the fiber. Although it is a method of reducing it, it is generally difficult to filter and refine the spinning raw material, and the elongation of the carbon fiber which can be achieved by this method is
It is considered that the limit is 3.0% for PAN-based carbon fibers and 2.4% for pitch-based carbon fibers. Also, one of the characteristics of carbon fiber is its crystal structure, but isotropic ones are chemically more stable and have higher compressive strength than those with anisotropic crystals. . Further, a fiber having an isotropic crystal structure may be preferable in order to suppress fibrillation due to weaving or friction of the fiber and to increase the compressive strength of the fiber. The crystal structure of carbon fiber varies depending on the heat treatment temperature during carbonization, but in the case of conventional PAN-based or high-elasticity pitch-based fiber, most of it becomes anisotropic at temperatures up to about 2000 ° C. There is no known carbon fiber that maintains X-ray isotropy even after heat treatment at a temperature of ℃ or higher.
【０００５】[0005]
【発明が解決しようとする課題】本発明の目的は、前記
従来技術の問題点を解決し、従来の炭素繊維に比較して
著しく高い伸度を有し、しかも等方性の結晶構造を有す
る炭素繊維及びその製造方法を提供することにある。The object of the present invention is to solve the above-mentioned problems of the prior art, to have a remarkably high elongation as compared with the conventional carbon fiber, and to have an isotropic crystal structure. It is to provide a carbon fiber and a manufacturing method thereof.
【０００６】[0006]
【課題を解決するための手段】本発明の第１は、伸度
２．５〜４．０％、引張強度１００〜４００ｋｇ／ｍｍ
2、弾性率３．５〜１０．０ｔｏｎ／ｍｍ2の物性値を有
し、かつＸ線回折測定により００２回折線を示さないＸ
線的に非晶質であることを特徴とする高伸度炭素繊維で
ある。本発明の第２は、芳香族スルホン酸類又はそれら
の塩がメチレン型結合を介して結合した高分子化合物を
主成分とする原料組成物を紡糸して得られる炭素繊維前
駆体フィラメントを炭化するに際し、この炭素繊維前駆
体フィラメントを、フィラメントの延伸率が０〜１００
％の範囲になるよう緊張力を付与して延伸させながら２
００〜５００℃の温度範囲内で、最高温度３８０〜５０
０℃となるような条件で熱処理し、更にこの延伸フィラ
メントを非酸化雰囲気下にフィラメントの収縮率が０〜
２０％の範囲に収まるように緊張力を付与しつつ５００
〜２４００℃の温度範囲内で、最高温度８００〜２４０
０℃となるような条件で熱処理することを特徴とする伸
度２．５〜４．０％、引張強度１００〜４００ｋｇ／ｍ
ｍ2、弾性率３．５〜１０．０ｔｏｎ／ｍｍ2の物性値を
有し、かつＸ線回折測定により００２回折線を示さない
Ｘ線的に非晶質である高伸度炭素繊維の製造方法であ
る。The first aspect of the present invention is that the elongation is 2.5 to 4.0% and the tensile strength is 100 to 400 kg / mm.
2, has a physical property values of the elastic modulus 3.5~10.0ton / mm 2, and do not show 002 diffraction line by X-ray diffraction measurement X
It is a high elongation carbon fiber characterized by being linearly amorphous. The second aspect of the present invention is to carbonize a carbon fiber precursor filament obtained by spinning a raw material composition mainly comprising a polymer compound in which aromatic sulfonic acids or salts thereof are bound through a methylene type bond. The carbon fiber precursor filament has a filament draw ratio of 0 to 100.
While applying tension and stretching so that it is within the range of 2%, 2
Within the temperature range of 00 to 500 ° C, the maximum temperature is 380 to 50
Heat treatment is performed under the condition that the temperature is 0 ° C., and the drawn filament has a shrinkage ratio of 0 to 0 in a non-oxidizing atmosphere.
500 while applying tension so that it falls within the range of 20%
Within the temperature range of ~ 2400 ° C, the maximum temperature is 800 ~ 240
Elongation 2.5 to 4.0%, tensile strength 100 to 400 kg / m, characterized by heat treatment under the condition of 0 ° C.
Production of X-ray amorphous high elongation carbon fiber having m 2 and a physical property value of elasticity of 3.5 to 10.0 ton / mm 2 and showing no 002 diffraction line by X-ray diffraction measurement. Is the way.
【０００７】本発明の炭素繊維の最大の特徴は、引張強
度の値に比較して弾性率が小さく、従来公知の炭素繊維
に比較して著しく高い伸度を有することである。更に、
２４００℃までの熱処理によっても、等方性の結晶構造
を維持しているという特徴も有している。本発明の炭素
繊維の好ましい製造方法の一つに芳香族スルホン酸類又
はそれらの塩がメチレン型結合を介して結合した高分子
化合物を原料とする方法がある。以下、芳香族スルホン
酸類又はそれらの塩がメチレン型結合を介して結合した
高分子化合物（以下、高分子化合物と略称する）を原料
とした本発明の炭素繊維の製造方法について、プロセス
に従って説明する。The most characteristic feature of the carbon fiber of the present invention is that it has a small elastic modulus as compared with the value of tensile strength and a remarkably high elongation as compared with the conventionally known carbon fiber. Furthermore,
It is also characterized in that it maintains an isotropic crystal structure even by heat treatment up to 2400 ° C. One of the preferred methods for producing the carbon fiber of the present invention is a method using as a raw material a polymer compound in which aromatic sulfonic acids or salts thereof are bound via a methylene type bond. Hereinafter, a method for producing a carbon fiber of the present invention using a polymer compound (hereinafter, abbreviated as polymer compound) in which aromatic sulfonic acids or salts thereof are bound through a methylene type bond as a raw material will be described according to processes. .
【０００８】本発明で使用する高分子化合物は、フェノ
−ルスルホン酸、ナフタレンスルホン酸、アントラセン
スルホン酸、フェナントレンスルホン酸等の各種芳香族
スルホン酸化合物若しくはそれらの塩又はこれらの混合
物をメチレン型結合を介して結合させたものであって、
これらの芳香族スルホン酸類をホルマリン等のアルデヒ
ド化合物と縮合反応させるなど、それ自体公知の方法に
より製造することができる。この高分子化合物の好まし
い例としては、ナフタレンスルホン酸のホルマリン縮合
物があげられる。これらの高分子化合物は、そのまま、
あるいは中和した形で水溶液として使用する。なお、必
要によりメタノ−ル等のアルコ−ル類などの水と容易に
混合する溶媒を添加し、水とこれらの溶媒を混合した水
系溶媒の溶液として使用してもよい。この水溶液の段階
で濾過することにより、紡糸及び炭化して得られる炭素
繊維の強度及び伸度の低下の原因となる繊維中の欠陥を
生じさせる不溶性の不純物を除去するのが好ましい。高
分子化合物は、アンモニウム塩又はナトリウム塩の形で
使用すると、安定で、しかも水やメタノ−ル等のアルコ
−ル系溶媒に容易に溶解し、濾過による不純物の除去が
容易であり、特に好ましい。この高分子化合物の水系溶
媒溶液に、必要により紡糸助剤として適量のポリビニル
アルコ−ル、ポリエチレングリコ−ル等の水溶性高分子
化合物を添加したのち、５０℃における粘度が５０〜２
０００ポイズとなるように水分量を調整して紡糸原液と
する。As the polymer compound used in the present invention, various aromatic sulfonic acid compounds such as phenol sulfonic acid, naphthalene sulfonic acid, anthracene sulfonic acid and phenanthrene sulfonic acid, salts thereof, or a mixture thereof with a methylene type bond. Connected through
It can be produced by a method known per se, such as a condensation reaction of these aromatic sulfonic acids with an aldehyde compound such as formalin. A preferable example of this polymer compound is a formalin condensate of naphthalene sulfonic acid. These high molecular compounds are
Alternatively, it is used as an aqueous solution in a neutralized form. If necessary, a solvent such as alcohols such as methanol, which is easily mixed with water, may be added and the mixture may be used as a solution of an aqueous solvent in which water and these solvents are mixed. It is preferable to remove insoluble impurities that cause defects in the fiber, which causes reduction in strength and elongation of the carbon fiber obtained by spinning and carbonizing, by filtering at the stage of this aqueous solution. When the polymer compound is used in the form of an ammonium salt or a sodium salt, it is stable and easily dissolved in an alcohol solvent such as water or methanol, and impurities can be easily removed by filtration, which is particularly preferable. . If necessary, an appropriate amount of a water-soluble polymer compound such as polyvinyl alcohol or polyethylene glycol is added as a spinning aid to the aqueous solvent solution of the polymer compound, and then the viscosity at 50 ° C. is 50 to 2
The water content is adjusted so as to be 000 poise to prepare a spinning dope.
【０００９】この紡糸原液を乾式紡糸し、炭素繊維前駆
体フィラメントを得る。紡糸は、通常、紡糸原液を複数
の紡糸孔を有する紡糸口金から押し出すことによって行
う。本発明の高分子化合物から得られる前駆体繊維フィ
ラメントは、熱溶融しないという特性を有しており、、
通常のＰＡＮ系やピッチ系の炭素繊維の製造においては
必須の工程である不融化処理工程を経ることなく、その
まま熱処理することにより炭素繊維を得ることができ
る。紡糸口金を出て、適度に乾燥された前駆体繊維フィ
ラメントは集束され、熱処理工程に処し、炭素繊維とす
る。This spinning dope is dry-spun to obtain carbon fiber precursor filaments. Spinning is usually performed by extruding a spinning dope from a spinneret having a plurality of spinning holes. The precursor fiber filament obtained from the polymer compound of the present invention has the property of not being melted by heat,
The carbon fiber can be obtained by heat treatment as it is without passing through the infusibilizing treatment step which is an essential step in the production of ordinary PAN-based or pitch-based carbon fiber. The appropriately dried precursor fiber filaments exiting the spinneret are bundled and subjected to a heat treatment step to form carbon fibers.
【００１０】本発明の方法においては、この熱処理工程
を２段階に分けて行うことを特徴とする。先ず、適度に
乾燥され、紡糸工程を出た炭素繊維前駆体フィラメント
を、フィラメントの延伸率が０〜１００％の範囲になる
よう緊張力を付与して延伸させながら２００〜５００℃
の温度範囲内で、最高温度３８０〜５００℃となるよう
な条件で熱処理する。ここで延伸率とは、次の式で表さ
れる数値である。 （延伸処理糸長さ−延伸処理前糸長さ）／延伸処理前糸
長さ×１００（％） 紡糸工程を出た炭素繊維前駆体フィラメントを、この温
度範囲内で緊張力を付与することなく熱処理するとフィ
ラメントは元の長さの７０〜８０％に収縮する。この第
１段の熱処理の温度は、高分子化合物中のスルホン酸基
が分解し、ＳＯ2の形で脱離する温度範囲であるため、
この温度範囲内で緊張力を付与することなく熱処理する
とフィラメント中に気泡等の欠陥が生じる原因となる。
そのため、この段階では繊維を延伸させることによりこ
れらの気泡の影響を防いでいるのである。熱処理時の最
高温度が３８０℃未満ではＳＯ2の脱離が不十分であ
り、また十分な延伸を行うことができず、５００℃を超
えると収縮が始まるので延伸率をコントロ−ルするのが
難しくなるので好ましくない。The method of the present invention is characterized in that the heat treatment step is performed in two steps. First, the carbon fiber precursor filaments that have been appropriately dried and have exited the spinning step are stretched by applying tension to stretch the filaments at a temperature of 0 to 100% while stretching at 200 to 500 ° C.
Within the temperature range, the heat treatment is performed under the condition that the maximum temperature is 380 to 500 ° C. Here, the stretching ratio is a numerical value represented by the following formula. (Length of stretch-treated yarn-Length of yarn before stretch treatment) / Length of yarn before stretch treatment × 100 (%) The carbon fiber precursor filaments that have gone out of the spinning process are not applied with tension in this temperature range. Upon heat treatment, the filament shrinks to 70-80% of its original length. The temperature of this first-stage heat treatment is in the temperature range in which the sulfonic acid group in the polymer compound is decomposed and released in the form of SO 2 ,
Heat treatment within this temperature range without applying tension causes defects such as bubbles in the filament.
Therefore, at this stage, the influence of these bubbles is prevented by stretching the fiber. If the maximum temperature during heat treatment is less than 380 ° C., the desorption of SO 2 is insufficient and sufficient stretching cannot be performed, and if it exceeds 500 ° C., shrinkage begins, so the stretching ratio should be controlled. It is difficult because it becomes difficult.
【００１１】ＳＯ2の脱離反応は吸熱反応であるため、
短時間で熱処理を行ってもフィラメントが融着する虞は
ない。従って、熱処理時間は５分以内、通常は２分以内
で十分である。延伸率が０％未満（収縮した状態）では
延伸による効果が小さく、また、１００％を超えるとフ
ィラメントの破断や毛羽の発生が生じるので好ましくな
い。付与する緊張力の大きさと延伸率とは、ほぼ比例関
係にあり、延伸率を０〜１００％の範囲とするために
は、フィラメント単位断面積当り２８〜２２６ｇ／ｍｍ
2の緊張力を付与すればよい。Since the elimination reaction of SO 2 is an endothermic reaction,
Even if the heat treatment is performed for a short time, there is no fear that the filaments will be fused. Therefore, a heat treatment time of 5 minutes or less, usually 2 minutes or less is sufficient. If the stretching ratio is less than 0% (shrinked state), the effect of stretching is small, and if it exceeds 100%, filament breakage or fuzzing occurs, which is not preferable. The magnitude of the tension applied and the draw ratio are almost in proportion to each other, and in order to set the draw ratio in the range of 0 to 100%, 28 to 226 g / mm per filament unit cross-sectional area is required.
A tension of 2 should be applied.
【００１２】また、延伸処理は一段で行ってもよいが、
この温度域において加熱ロ−ラ−等を用いて多段で行う
と一層効果的である。また、フィラメントに振動を与え
ながら延伸するのも効果がある。次にこの第１段の熱処
理を行った延伸フィラメントを、非酸化雰囲気下にフィ
ラメントの収縮率が０〜２０％の範囲に収まるように緊
張力を付与しつつ５００〜２４００℃の温度範囲内で、
最高温度８００〜２４００℃となるような条件で第２段
の熱処理を行い炭化する。ここで収縮率とは、次の式で
表される数値である。The stretching treatment may be carried out in a single stage,
It is more effective to carry out in multiple stages in this temperature range using a heating roller or the like. It is also effective to stretch the filament while applying vibration. Next, the drawn filament that has been subjected to the first-stage heat treatment is applied in a temperature range of 500 to 2400 ° C. under a non-oxidizing atmosphere while applying tension so that the shrinkage rate of the filament falls within the range of 0 to 20%. ,
The second stage heat treatment is performed under the condition that the maximum temperature is 800 to 2400 ° C. to carbonize. Here, the contraction rate is a numerical value represented by the following formula.
【００１３】（延伸処理糸長さ−炭化処理糸長さ）／延
伸処理糸長さ×１００（％） この熱処理は、繊維の酸化を防止するため、非酸化性雰
囲気下に行うことが必要である。 この第２段の熱処理
も１段で行ってもよいが、この温度域において炭化炉を
多段にし、中間に速度の異なるフィ−ドロ−ラ−を入れ
るなどの方法により、多段の収縮抑制処理を行いながら
炭化するのが効果的である。第１段の熱処理を行った延
伸フィラメントを、この温度範囲内で緊張力を付与する
ことなく熱処理するとフィラメントは延伸されたフィラ
メントの長さの６０〜８０％に収縮する。この第２段の
熱処理では、主として硫化水素、タ−ル、炭化水素及び
水素が揮散し、炭化が進行する。この段階では、繊維の
炭素化が一部進行しているため、もはや延伸させること
はできないが、緊張力を付与させながら熱処理すること
により収縮率を０〜２０％の範囲に抑え、それにより延
伸と同様の効果を生じさせているのである。(Length of stretched yarn-length of carbonized yarn) / length of stretched yarn × 100 (%) This heat treatment needs to be carried out in a non-oxidizing atmosphere in order to prevent oxidation of the fibers. is there. This second-stage heat treatment may also be performed in a single stage, but a multistage shrinkage suppression treatment can be performed by, for example, making the carbonization furnace multistage in this temperature range and inserting a feeder roller having a different speed in the middle. It is effective to carbonize while performing. When the first-stage heat-treated drawn filament is heat-treated within this temperature range without applying tension, the filament shrinks to 60 to 80% of the length of the drawn filament. In this second stage heat treatment, mainly hydrogen sulfide, tar, hydrocarbons and hydrogen are volatilized and carbonization proceeds. At this stage, the carbonization of the fibers has been partially progressed, so that it cannot be stretched anymore, but the shrinkage rate is suppressed to a range of 0 to 20% by heat treatment while imparting a tension force, whereby the stretching is performed. It produces the same effect as.
【００１４】熱処理時の最高温度が８００℃未満では炭
化が不十分であり、２４００℃を超えると異方性が発現
し、またこれ以上温度を上昇させても弾性率の大幅な増
加は認められないのでエネルギ−のロスとなるので好ま
しくない。熱処理時間は０．５〜５分とする。０．５分
未満では炭化が不十分となりやすく、また、５分の熱処
理で得られる炭素繊維の諸物性は上限値になり、より長
時間の熱処理を行ってもそれ以上の物性の向上は期待で
きない。このように短時間で熱処理を完了させるために
は繊維を開繊した状態で熱処理するのが望ましい。When the maximum temperature during heat treatment is less than 800 ° C, carbonization is insufficient, and when it exceeds 2400 ° C, anisotropy is exhibited, and even if the temperature is further increased, a large increase in elastic modulus is recognized. Since there is no energy, energy loss occurs, which is not preferable. The heat treatment time is 0.5 to 5 minutes. If it is less than 0.5 minutes, carbonization tends to be insufficient, and the physical properties of the carbon fiber obtained by the heat treatment for 5 minutes become the upper limit values, and further improvement of the physical properties is expected even if the heat treatment is performed for a longer time. Can not. In order to complete the heat treatment in such a short time, it is desirable to perform the heat treatment with the fibers being opened.
【００１５】収縮率を０％未満に抑えようとすると繊維
の破断を生じやすくなり、また、２０％を超えると収縮
抑制の効果が小さくなり、強度が低くなるので好ましく
ない。収縮率を前記範囲内に抑えるためには、フィラメ
ントの単位断面積当り１１０〜８７０ｇ／ｍｍ2の緊張
力を付与しつつ熱処理を行えばよい。本炭素繊維の製造
方法においては、前記の延伸処理に必要な緊張力に比べ
収縮抑制に必要な緊張力の方が大であるので、延伸熱処
理工程と収縮制御熱処理工程とでは別々に緊張力を制御
する必要がある。延伸熱処理工程と収縮制御熱処理工程
を直結し、１段階で緊張力を付与して熱処理すると、延
伸用に十分な緊張力では収縮抑制に不十分となり、また
収縮抑制に十分な緊張力では延伸時にかかる張力が大き
すぎ糸切れを起しやすくなる。本発明の方法によれば、
フィラメントの径が２０μｍ以下であれば、８００℃で
の熱処理により１００ｋｇ／ｍｍ2以上の強度の炭素繊
維が得られ、強度は熱処理温度の上昇に伴って増加し、
最高４００ｋｇ／ｍｍ2程度の炭素繊維を得ることがで
きる。If the shrinkage ratio is controlled to be less than 0%, the fiber tends to be broken, and if it exceeds 20%, the effect of suppressing the shrinkage becomes small and the strength becomes low, which is not preferable. In order to suppress the shrinkage ratio within the above range, heat treatment may be performed while applying a tension force of 110 to 870 g / mm 2 per unit cross-sectional area of the filament. In the production method of the present carbon fiber, since the tension force required for shrinkage suppression is larger than the tension force required for the stretching treatment, tension forces are separately applied in the stretching heat treatment step and the shrinkage control heat treatment step. Need to control. When the stretching heat treatment step and the shrinkage control heat treatment step are directly connected and heat treatment is performed by applying tension in one step, sufficient tension for stretching will not be enough to suppress shrinkage, and tension sufficient to suppress shrinkage will cause Such tension is too high and thread breakage easily occurs. According to the method of the present invention,
If the diameter of the filament is 20 μm or less, heat treatment at 800 ° C. gives carbon fibers having a strength of 100 kg / mm 2 or more, and the strength increases as the heat treatment temperature increases,
It is possible to obtain carbon fibers having a maximum of about 400 kg / mm 2 .
【００１６】本発明の方法によって得られる炭素繊維
は、熱処理温度を２４００℃まで上げてもＸ線回折測定
による００２回折線を示さないＸ線的に非晶質の炭素繊
維である。従って、熱処理温度が上昇しても弾性率が大
きくなる傾向は小さく、２４００℃で熱処理して炭化し
たものでも弾性率は１０ｔｏｎ／ｍｍ2以下である。The carbon fibers obtained by the method of the present invention are X-ray amorphous carbon fibers which do not show 002 diffraction lines by X-ray diffraction measurement even if the heat treatment temperature is raised to 2400 ° C. Therefore, even if the heat treatment temperature rises, the elastic modulus does not tend to increase, and even the one heat-treated at 2400 ° C. and carbonized has an elastic modulus of 10 ton / mm 2 or less.
【００１７】[0017]
【実施例】以下、実施例により本発明を更に具体的に説
明する。The present invention will be described in more detail with reference to the following examples.
【００１８】（実施例１）精製ナフタレン（純度９９．
９ｗｔ％）１０モルに９８％硫酸１０モルを加え、１６
０℃で２時間反応させてスルホン化し、未反応ナフタレ
ン及び反応生成水を減圧下に留去した。次いでホルムア
ルデヒド１０モル相当量の３５％ホルマリン水溶液を加
え、１０５℃で５時間反応させ、ナフタレンスルホン酸
のメチレン型縮合物を得た。これをアンモニアで中和し
たのち、未溶解物を濾別し、濾液を濃縮して水分を３４
重量％に調整して紡糸原液とした。この紡糸原液を直径
０．１ｍｍの紡糸孔２０００を有するステンレス製口金
を用いて紡糸し、２０００本のフィラメントからなる原
糸（炭素繊維前駆体マルチフィラメント）を得た。この
原糸を入口温度２００℃、出口温度４５０℃にセットし
た延伸用（第１段熱処理用）電気炉に連続的に送糸し、
空気雰囲気下に、所定の緊張力を付与して延伸を制御し
ながら炉内の滞留時間１分間の延伸熱処理（第１段熱処
理）を行った。第１段熱処理を受けた延伸糸を、続いて
入口温度５００℃、出口温度１６００℃にセットした収
縮制御用（第２段熱処理用）電気炉に送糸し、非酸化雰
囲気下に、緊張力を付与して収縮率が所定の値になるよ
う制御しながら炉内の滞留時間４０秒で通過させて熱処
理（第２段熱処理）して炭化した。延伸率及び収縮率を
変化させ、得られた炭素繊維の物性を表１に示す。表１
の結果から、本発明の炭素繊維は、従来の炭素繊維には
見られない高い伸度を有する繊維であることが分かる。(Example 1) Purified naphthalene (purity 99.
9 wt%) 10 mol, 98% sulfuric acid 10 mol was added to give 16
The mixture was reacted at 0 ° C. for 2 hours to be sulfonated, and unreacted naphthalene and reaction product water were distilled off under reduced pressure. Then, a 35% formalin aqueous solution corresponding to 10 mol of formaldehyde was added, and the mixture was reacted at 105 ° C. for 5 hours to obtain a methylene type condensate of naphthalenesulfonic acid. After neutralizing this with ammonia, the undissolved material is filtered off and the filtrate is concentrated to remove water.
The spinning dope was prepared by adjusting it to the weight percentage. This spinning dope was spun using a stainless steel spinneret having a spinning hole 2000 with a diameter of 0.1 mm to obtain a yarn (carbon fiber precursor multifilament) consisting of 2000 filaments. The raw yarn was continuously fed to an electric furnace for drawing (for first stage heat treatment) set at an inlet temperature of 200 ° C. and an outlet temperature of 450 ° C.,
A stretching heat treatment (first-stage heat treatment) was performed under an air atmosphere for a residence time of 1 minute in the furnace while applying a predetermined tension force to control the stretching. The drawn yarn that has undergone the first-stage heat treatment is then fed into an electric furnace for shrinkage control (for the second-stage heat treatment) set at an inlet temperature of 500 ° C and an outlet temperature of 1600 ° C, and tensioned under a non-oxidizing atmosphere. Was added to control the shrinkage ratio to be a predetermined value, and the mixture was allowed to pass through the furnace with a residence time of 40 seconds to be heat-treated (second heat treatment) and carbonized. Table 1 shows the physical properties of the carbon fibers obtained by changing the stretching ratio and the shrinkage ratio. Table 1
From the results, it can be seen that the carbon fiber of the present invention is a fiber having a high elongation not found in conventional carbon fibers.
【００１９】[0019]
【表１】 [Table 1]
【００２０】更に表１の実験Ｎｏ．４−３の炭素繊維を
２０００〜３０００℃で３０分間熱処理し、Ｘ線回折測
定を行った。図１に各温度で処理した炭素繊維につい
て、炭素００２面のＸ線回折測定結果を示す。図１か
ら、本発明の炭素繊維は２４００℃までは００２回折線
は認められず、非晶質（等方性）の繊維であることが分
かる。Further, the experiment No. The carbon fiber No. 4-3 was heat-treated at 2000 to 3000 ° C. for 30 minutes, and X-ray diffraction measurement was performed. FIG. 1 shows the X-ray diffraction measurement result of the carbon 002 surface of the carbon fiber treated at each temperature. It can be seen from FIG. 1 that the carbon fiber of the present invention has no 002 diffraction line up to 2400 ° C. and is an amorphous (isotropic) fiber.
【００２１】（実施例２）実施例１で使用したのと同じ
原糸を入口温度２００℃、出口温度５００℃にセットし
た延伸用（第１段熱処理用）電気炉に連続的に送糸し、
酸素濃度１０％の窒素気流下で、延伸率が１００％とな
るように緊張力を付与しながら炉内の滞留時間４０秒で
延伸熱処理（第１段熱処理）を行った。第１段熱処理を
受けた延伸糸を、続いて入口温度５００℃、出口温度７
００℃にセットした前段の収縮制御用（第２段熱処理
用）電気炉（低温側）に送糸し、非酸化雰囲気下に、収
縮率が０％となるように緊張力を付与しながら通過さ
せ、次いで入口温度７００℃、出口温度１６００℃にセ
ットした後段の収縮制御用（第２段熱処理用）電気炉
（高温側）に送糸し、非酸化雰囲気下に、収縮率が５％
となるように緊張力を付与しながら通過させるよう制御
しながら炉内の滞留時間４０秒で通過させて熱処理（第
２段熱処理）して炭化した。得られた炭素繊維の繊維径
は８．６μｍ、伸度は４．２％、引張強度は３９３ｋｇ
／ｍｍ2、弾性率は９．３６ｔｏｎ／ｍｍ2であり、繊維
束には毛羽は認められず良好な状態であった。(Example 2) The same raw yarn as used in Example 1 was continuously fed to an electric furnace for drawing (for first stage heat treatment) set at an inlet temperature of 200 ° C and an outlet temperature of 500 ° C. ,
Stretching heat treatment (first-stage heat treatment) was performed under a nitrogen stream with an oxygen concentration of 10% while applying tension so that the stretching ratio would be 100%, with a residence time of 40 seconds in the furnace. The drawn yarn that has undergone the first-stage heat treatment is then subjected to an inlet temperature of 500 ° C. and an outlet temperature of 7
The yarn is sent to the electric furnace (low temperature side) for shrinkage control (for the second stage heat treatment) set at 00 ° C and passed under a non-oxidizing atmosphere while applying tension so that the shrinkage rate becomes 0%. Then, the temperature is set to 700 ° C. at the inlet and 1600 ° C. at the outlet, and the yarn is fed to the electric furnace (high temperature side) for the subsequent stage shrinkage control (for the second stage heat treatment).
It was passed through the furnace with a residence time of 40 seconds and heat-treated (second-stage heat treatment) to be carbonized while being controlled so as to give a tension force so that The carbon fiber obtained had a fiber diameter of 8.6 μm, an elongation of 4.2%, and a tensile strength of 393 kg.
/ Mm 2 , the elastic modulus was 9.36 ton / mm 2 , and no fluff was observed in the fiber bundle, which was in a good state.
【００２２】（比較例１）実施例１で使用したのと同じ
原糸を入口温度２００℃、出口温度４００℃にセットし
た電気炉に連続的に送糸し、非酸化性雰囲気下で、緊張
力を付与することなしに炉内の滞留時間１分間で熱処理
（第１段熱処理）した。この熱処理により原糸は２７．
５％収縮した。この熱処理糸を入口温度５００℃、出口
温度１２００℃にセットした電気炉に送糸し、非酸化雰
囲気下に、緊張力を付与することなく炉内の滞留時間４
０秒で通過させて熱処理（第２段熱処理）して炭化し
た。炭化炉内での収縮率は１３．５％であり、原糸から
炭素繊維までの収縮率は３５．２％であった。得られた
炭素繊維は繊維径１５．０μｍで、伸度は２．１％、引
張強度は８０ｋｇ／ｍｍ2、弾性率は３．８ｔｏｎ／ｍ
ｍ2であり、いずれも低い値であった。(Comparative Example 1) The same raw yarn as that used in Example 1 was continuously fed to an electric furnace set at an inlet temperature of 200 ° C and an outlet temperature of 400 ° C, and tensioned in a non-oxidizing atmosphere. Heat treatment (first stage heat treatment) was performed for 1 minute residence time in the furnace without applying force. By this heat treatment, the raw yarn becomes 27.
Shrink 5%. The heat-treated yarn was fed into an electric furnace set at an inlet temperature of 500 ° C. and an outlet temperature of 1200 ° C., and the residence time in the furnace was 4 in a non-oxidizing atmosphere without applying tension.
It was passed in 0 seconds to be heat treated (second heat treatment) and carbonized. The shrinkage ratio in the carbonization furnace was 13.5%, and the shrinkage ratio from the raw yarn to the carbon fiber was 35.2%. The carbon fiber obtained had a fiber diameter of 15.0 μm, an elongation of 2.1%, a tensile strength of 80 kg / mm 2 , and an elastic modulus of 3.8 ton / m.
m 2 and all were low values.
【００２３】（比較例２）実施例１で使用したのと同じ
原糸を入口温度２００℃、出口温度５００℃にセットし
た空気雰囲気の電気炉Ａと入口温度５００℃、出口温度
２２００℃にセットした不活性雰囲気の電気炉Ｂに連続
的に送糸し、電気炉Ａの入口と電気炉Ｂの出口に設けた
フィ−ドロ−ラ−で原糸から炭素繊維までの全工程延伸
率を表１の実施例１の実験Ｎｏ．１−１と同じ−２０％
とし、かつ電気炉Ａ及び電気炉Ｂでの滞留時間を１分４
０秒間として炭素繊維の製造を試みたが、電気炉内での
糸切れが頻発し、良好な炭素繊維を得ることはできなか
った。(Comparative Example 2) The same raw yarn as that used in Example 1 was set in an electric furnace A in an air atmosphere in which the inlet temperature was 200 ° C and the outlet temperature was 500 ° C, and the inlet temperature was 500 ° C and the outlet temperature was 2200 ° C. The yarn was continuously fed to the electric furnace B in an inert atmosphere as described above, and the drawing ratio of the entire process from the raw yarn to the carbon fiber was displayed by a feeder provided at the inlet of the electric furnace A and the outlet of the electric furnace B. Experiment No. 1 of the first embodiment. Same as 1-1-20%
And the residence time in electric furnace A and electric furnace B is 1 minute 4
An attempt was made to produce carbon fibers for 0 seconds, but yarn breakage frequently occurred in the electric furnace, and good carbon fibers could not be obtained.
【００２４】[0024]
【発明の効果】本発明の炭素繊維は、引張強度１００〜
４００ｋｇ／ｍｍ2、弾性率３．５〜１０．０ｔｏｎ／
ｍｍ2と引張強度の割には弾性率が小さく、２．５〜
４．０％という従来の炭素繊維には見られなかった高い
伸度を有し、かつＸ線回折測定により００２回折線を示
さないＸ線的に非晶質である高伸度炭素繊維であり、各
種複合材料の補強用繊維として極めて優れた特性を有し
ており、工業的に利用価値の大きい繊維である。The carbon fiber of the present invention has a tensile strength of 100 to 100.
400 kg / mm 2 , elastic modulus 3.5 to 10.0 ton /
mm 2 and tensile strength have a small elastic modulus,
A high elongation carbon fiber having an elongation of 4.0%, which was not found in conventional carbon fibers, and being amorphous in X-ray, showing no 002 diffraction line by X-ray diffraction measurement. The fiber has excellent properties as a reinforcing fiber for various composite materials and is industrially useful.
【００２５】本発明の方法によれば、炭素繊維前駆体フ
ィラメントの熱処理を２段階に分け、それぞれの段階で
適切な緊張力を付与して、延伸又は収縮の抑制を行いな
がら熱処理することにより、欠陥の少ない繊維を得るこ
とができるようになり、前記特性を有する高伸度炭素繊
維の製造が可能となった。また、熱処理条件をこのよう
に管理することにより、熱処理に要する時間も短縮で
き、プロセスの簡略化ができる効果もある。According to the method of the present invention, the heat treatment of the carbon fiber precursor filaments is divided into two stages, and appropriate tension is applied at each stage to perform heat treatment while suppressing stretching or shrinkage. It has become possible to obtain fibers with few defects, and it has become possible to produce high elongation carbon fibers having the above characteristics. Further, by controlling the heat treatment conditions in this way, the time required for the heat treatment can be shortened and the process can be simplified.
【図１】 本発明の炭素繊維を所定の温度で熱処理した
場合のＸ線回折線図である。FIG. 1 is an X-ray diffraction diagram when the carbon fiber of the present invention is heat-treated at a predetermined temperature.
Claims (2)
〜４００ｋｇ／ｍｍ2、弾性率３．５〜１０．０ｔｏｎ
／ｍｍ2の物性値を有し、かつＸ線回折測定により００
２回折線を示さないＸ線的に非晶質であることを特徴と
する高伸度炭素繊維。1. An elongation of 2.5 to 4.0% and a tensile strength of 100.
~ 400 kg / mm 2 , elastic modulus 3.5 to 10.0 ton
Has a physical property value of / mm 2 and is 00 by X-ray diffraction measurement.
A high elongation carbon fiber characterized by being X-ray amorphous showing no 2 diffraction lines.
チレン型結合を介して結合した高分子化合物を主成分と
する原料組成物を紡糸して得られる炭素繊維前駆体フィ
ラメントを炭化するに際し、この炭素繊維前駆体フィラ
メントを、フィラメントの延伸率が０〜１００％の範囲
になるよう緊張力を付与して延伸させながら２００〜５
００℃の温度範囲内で、最高温度３８０〜５００℃とな
るような条件で熱処理し、更にこの延伸フィラメントを
非酸化雰囲気下にフィラメントの収縮率が０〜２０％の
範囲に収まるように緊張力を付与しつつ５００〜２４０
０℃の温度範囲内で、最高温度８００〜２４００℃とな
るような条件で熱処理することを特徴とする伸度２．５
〜４．０％、引張強度１００〜４００ｋｇ／ｍｍ2、弾
性率３．５〜１０．０ｔｏｎ／ｍｍ2の物性値を有し、
かつＸ線回折測定により００２回折線を示さないＸ線的
に非晶質である高伸度炭素繊維の製造方法。2. When carbonizing a carbon fiber precursor filament obtained by spinning a raw material composition mainly comprising a polymer compound in which aromatic sulfonic acids or salts thereof are bound via a methylene type bond, 200 to 5 while stretching the carbon fiber precursor filament by applying a tension force so that the filament draw ratio is in the range of 0 to 100%.
In the temperature range of 00 ° C, heat treatment is performed under the condition that the maximum temperature is 380 to 500 ° C, and the stretched filament is tensioned in a non-oxidizing atmosphere so that the shrinkage rate of the filament falls within the range of 0 to 20%. 500 to 240 while giving
Within the temperature range of 0 ° C, heat treatment is performed under the condition that the maximum temperature is 800 to 2400 ° C, and the elongation is 2.5.
˜4.0%, tensile strength 100 to 400 kg / mm 2 , elastic modulus 3.5 to 10.0 ton / mm 2 ,
And a method for producing a high elongation carbon fiber which is X-ray amorphous and does not show 002 diffraction line by X-ray diffraction measurement.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34358692A JPH06173122A (en) | 1992-12-01 | 1992-12-01 | High-elongation carbon fiber and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34358692A JPH06173122A (en) | 1992-12-01 | 1992-12-01 | High-elongation carbon fiber and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH06173122A true JPH06173122A (en) | 1994-06-21 |
Family
ID=18362678
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34358692A Pending JPH06173122A (en) | 1992-12-01 | 1992-12-01 | High-elongation carbon fiber and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH06173122A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015105019A1 (en) | 2014-01-08 | 2015-07-16 | 国立大学法人東京大学 | Pan-based carbon fiber and production method therefor |
| CN111393167A (en) * | 2020-03-25 | 2020-07-10 | 宁波材料所杭州湾研究院 | Novel MAX phase composite material and preparation method thereof |
-
1992
- 1992-12-01 JP JP34358692A patent/JPH06173122A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2015105019A1 (en) | 2014-01-08 | 2015-07-16 | 国立大学法人東京大学 | Pan-based carbon fiber and production method therefor |
| KR20160106044A (en) | 2014-01-08 | 2016-09-09 | 고쿠리츠다이가쿠호우진 도쿄다이가쿠 | Pan-based carbon fiber and production method therefor |
| CN111393167A (en) * | 2020-03-25 | 2020-07-10 | 宁波材料所杭州湾研究院 | Novel MAX phase composite material and preparation method thereof |
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