JPH0860446A - Method for heat-treating carbon fiber by vapor-phase method - Google Patents
Method for heat-treating carbon fiber by vapor-phase methodInfo
- Publication number
- JPH0860446A JPH0860446A JP21667394A JP21667394A JPH0860446A JP H0860446 A JPH0860446 A JP H0860446A JP 21667394 A JP21667394 A JP 21667394A JP 21667394 A JP21667394 A JP 21667394A JP H0860446 A JPH0860446 A JP H0860446A
- Authority
- JP
- Japan
- Prior art keywords
- molded body
- carbon fiber
- molding
- vapor grown
- cylinder
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は気相法の炭素繊維、より
詳しくは有機化合物の熱分解による気相成長法によって
得られた炭素繊維を熱処理する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor grown carbon fiber, and more particularly to a method for heat treating a carbon fiber obtained by a vapor growth method by thermal decomposition of an organic compound.
【０００２】[0002]
【従来の技術】気相成長炭素繊維の製造方法は、反応炉
内で有機化合物を熱分解してウイスカー状の微細な炭素
繊維を１工程で得ることの出来る優れた方法である。し
かし工業的な生産性に問題があり種々改善がなされてき
た。例えば初めはセラミック基板に遷移金属の超微粒子
を付着させてから有機化合物を供給し分解させ長時間成
長させて比較的太く長い気相法炭素繊維を製造する方法
であった（特開昭５２−１０３５２８）。2. Description of the Related Art A method for producing a vapor grown carbon fiber is an excellent method in which a fine whisker-like carbon fiber can be obtained in one step by thermally decomposing an organic compound in a reaction furnace. However, there are problems in industrial productivity and various improvements have been made. For example, a method of initially depositing ultrafine particles of a transition metal on a ceramic substrate and then supplying an organic compound to decompose and grow for a long time to produce a relatively thick and long vapor grown carbon fiber (Japanese Patent Laid-Open No. 52-52). 103528).
【０００３】この方法は良好な物性の炭素繊維が得られ
るが、繊維径が太くなることや反応速度が遅いことが、
工業生産に向かないなど不十分な点が多かった。これを
改善するために、鉄を始めとする遷移金属またはその化
合物を触媒とし、この触媒とキャリヤーガス及び例えば
ベンゼン、トルエン、天然ガス等の有機化合物を液また
は気体状で反応炉に導入して有機化合物を８００℃〜１
３００℃程度で熱分解し、微細な炭素繊維を短時間で生
産する方法が開発され生産性が改善された。Although carbon fibers having good physical properties can be obtained by this method, the fact that the fiber diameter becomes large and the reaction rate is slow,
There were many inadequate points such as not suitable for industrial production. In order to improve this, a transition metal such as iron or a compound thereof is used as a catalyst, and the catalyst and a carrier gas and an organic compound such as benzene, toluene and natural gas are introduced into a reaction furnace in a liquid or gaseous state. 800 ° C to 1 for organic compounds
A method for producing fine carbon fibers by thermal decomposition at about 300 ° C. in a short time was developed to improve productivity.
【０００４】これら気相法炭素繊維の製造方法としては フェロセン等の遷移金属化合物を気化させ反応炉（熱
分解炉）に導入し、遷移金属の微粒子を生成させシード
として用い製造する方法（特開昭６０−５４９９８）。 鉄等の遷移金属を直接熱分解炉中で気化させてシード
を作り製造する方法（特開昭６１−２９１４９７）。 フェロセン等の遷移金属化合物を液体有機化合物に分
散あるいは溶解させて反応炉中にスプレーしてシードと
して製造する方法（特開昭５８−１８０６１５）。 等によって製造されるようになった。これらの方法によ
って得られる気相法炭素繊維は繊維径が０．０１μｍ〜
５μｍ、長さ１μｍ〜１０００μｍ程度の繊維状を形成
し、黒鉛構造の網面が繊維軸に沿って発達し、内部に中
空の孔があるのが特徴である。As a method for producing these vapor grown carbon fibers, a method in which a transition metal compound such as ferrocene is vaporized and introduced into a reaction furnace (pyrolysis furnace), fine particles of the transition metal are produced and used as seeds (JP 60-54998). A method for producing a seed by directly vaporizing a transition metal such as iron in a pyrolysis furnace (JP-A-61-291497). A method in which a transition metal compound such as ferrocene is dispersed or dissolved in a liquid organic compound and sprayed in a reaction furnace to produce a seed (Japanese Patent Application Laid-Open No. 58-180615). It came to be manufactured by. The vapor grown carbon fiber obtained by these methods has a fiber diameter of 0.01 μm to
It is characterized by forming a fibrous form having a length of 5 μm and a length of about 1 μm to 1000 μm, a mesh surface of a graphite structure developed along the fiber axis, and having hollow holes inside.
【０００５】この炭素繊維には通常タール分、粒状炭
素、触媒の金属やその化合物が含まれ、これらの炭素や
金属等がタールによって繊維に付着している。製品とし
てはこれらを除去する必要がある。通常は加熱（熱処
理）してタール分を炭化し、得られた繊維の凝集体を解
砕あるいは粉砕し、気流分級等で粒状炭素や金属等を除
去している。また気相法炭素繊維は高くとも１３００℃
程度の温度で製造されたものであり、黒鉛の結晶構造が
十分に発達していない。そのために用途によってはさら
に高温で熱処理して黒鉛の結晶構造を発達させ、電気や
熱の伝導性をよくする方法が採用されている。従来の熱
処理方法は繊維の集合体を加熱されている管内を通すか
あるいは容器に入れて電気炉等の中で加熱する等の外熱
法がとられている。This carbon fiber usually contains tar, granular carbon, a metal of a catalyst and its compound, and these carbon and metal are attached to the fiber by tar. These need to be removed as a product. Usually, the tar content is carbonized by heating (heat treatment), the obtained fiber aggregates are crushed or crushed, and the particulate carbon, metal, etc. are removed by airflow classification or the like. In addition, vapor grown carbon fiber is at most 1300 ℃
It was manufactured at a moderate temperature, and the crystal structure of graphite is not fully developed. Therefore, depending on the application, a method is adopted in which heat treatment is further performed at a high temperature to develop the crystal structure of graphite and improve the electrical and thermal conductivity. The conventional heat treatment method is an external heating method such as passing the fiber aggregate through a heated tube or putting it in a container and heating it in an electric furnace or the like.
【０００６】[0006]
【発明が解決しようとする課題】本発明における気相法
炭素繊維は上記のような微細なもので、それが集合体を
なし、粉末状を呈している（以下この集合体を繊維状粉
末という）。 １）繊維状粉末はその嵩密度が０．００５ｇ／ｃｍ2 以
下と小さいため繊維状粉末のまま熱処理するには処理に
要する加熱炉を始め処理設備容量が大きくなり処理コス
トが高くなる原因となる。 ２）繊維状粉末の熱処理は通常外部加熱の炉を使う。し
かし、繊維状粉末は嵩密度が小さいために設備容量が大
きく充填率も小さい。従って、熱伝導率も小さく熱効率
が悪くなり、結果的にコストが高くなる。 ３）繊維状粉末のまま加熱処理するには繊維状粉末の移
送機構が必要となり、しかも１５００℃以上の高温域を
移送するには設備的にも材質的にも問題が多く複雑とな
るばかりではなく、繊維状粉末の付着や詰まりのトラブ
ルで実用になりにくい。そこで、通常繊維状粉末を容器
に充填し、ほとんどが容器のまま加熱処理する方法がと
られている。しかしこの方法では、繊維状粉末のように
嵩密度が小さい粉体では容器内に充填する繊維の量は著
しく少なく、熱はほとんど容器を加熱することに費やさ
れ、その結果熱処理コストが高くなる。 ４）容器の材質は１４００℃以上、特に２０００℃以上
での高温処理になるとこの温度にもつ材料は少なく、ま
た繊維状粉末の異種元素による汚染などを考慮し、黒鉛
ルツボの様な炭素材料が望ましい。しかし黒鉛でも高温
では僅かに混入する酸素や窒素等による腐食が激しく長
期間の使用は無理で消耗品となってしまう。本発明は繊
維状粉末を熱処理する際の上記の様な装置上等の問題が
なく、かつ熱効率のよい熱処理方法を提供することを目
的とする。The vapor grown carbon fiber according to the present invention is such a fine fiber as described above, which forms an aggregate and is in the form of powder (hereinafter, this aggregate is referred to as fibrous powder. ). 1) Since the bulk density of fibrous powder is as small as 0.005 g / cm 2 or less, heat treatment of fibrous powder as it is causes a large amount of processing equipment such as a heating furnace required for the treatment and a high treatment cost . 2) The heat treatment of the fibrous powder usually uses an external heating furnace. However, since the fibrous powder has a small bulk density, it has a large installed capacity and a small filling rate. Therefore, the thermal conductivity is small and the thermal efficiency is poor, resulting in a high cost. 3) In order to heat-treat the fibrous powder as it is, a transfer mechanism for the fibrous powder is required, and in order to transfer a high temperature region of 1500 ° C. or higher, there are many problems in terms of equipment and materials, and it is not only complicated. No, it is difficult to put into practical use due to the trouble of adhesion and clogging of fibrous powder. Therefore, a method is generally used in which a fibrous powder is filled in a container and most of the container is heat-treated as it is. However, in this method, in the case of powder having a low bulk density such as fibrous powder, the amount of fibers filled in the container is extremely small, and most of the heat is spent for heating the container, resulting in high heat treatment cost. . 4) The material of the container is 1400 ° C or higher, especially at 2000 ° C or higher, there are few materials that have this temperature, and in consideration of contamination of fibrous powder by different elements, carbon material such as graphite crucible is used. desirable. However, even with graphite, at high temperatures, it is corroded slightly by oxygen and nitrogen, etc., and it is impossible to use it for a long time and it becomes a consumable product. An object of the present invention is to provide a heat treatment method which is free from the above-mentioned problems in the apparatus for heat treatment of fibrous powder and has high thermal efficiency.
【０００７】[0007]
【課題を解決するための手段】本発明者は微細な気相法
炭素繊維は単繊維自体で電気比抵抗は０．０００１〜
０．００１Ωｃｍであって通常の炭素材料と同様に導電
性がよいこと、また生成したままの繊維状粉末は嵩密度
が非常に小さいがタール分等が含まれているため、圧縮
成形することにより、嵩密度の高い成形体が得られるこ
とに着目し、本発明に到達した。即ち、本発明は微細な
気相法炭素繊維を圧縮成形して成形体の嵩密度を０．０
３ｇ／ｃｍ3 以上とし、該成形体の両側に電極端子を当
接し、成形体に通電加熱することを特徴とする気相法炭
素繊維の熱処理方法である。The present inventors have found that fine vapor grown carbon fiber is a single fiber itself and has an electrical resistivity of 0.0001 to
It has a conductivity of 0.001 Ωcm as well as a normal carbon material, and the as-produced fibrous powder has a very low bulk density but contains tar and the like. The present invention has been achieved, focusing on the fact that a molded product having a high bulk density can be obtained. That is, in the present invention, fine vapor grown carbon fibers are compression-molded to have a bulk density of 0.0
The heat treatment method for vapor grown carbon fiber is characterized in that it is 3 g / cm 3 or more, and electrode terminals are brought into contact with both sides of the molded body, and the molded body is electrically heated.
【０００８】本発明で使用される微細な気相法炭素繊維
は前記したように直径が０．０１μｍ〜５μｍ、長さが
１μｍ〜１０００μｍ程度の繊維が集合した繊維状粉末
である。生成したままの繊維状粉末は嵩密度が０．００
５ｇ／ｃｍ3 以下と非常に小さいので、先ずこれを圧縮
成形する。繊維状粉末は金型や圧縮方法を選ぶことによ
りあらゆる形状に成形が可能である。例えば円柱状、立
方体、直方体、角柱、平板状等であり、その他複雑な形
状でも成形できる。しかし工業的にはできるだけ単純な
形状でかつ両側（両端）から通電し易いように円柱や角
柱が望ましい。The fine vapor grown carbon fiber used in the present invention is a fibrous powder in which fibers having a diameter of 0.01 μm to 5 μm and a length of 1 μm to 1000 μm are aggregated as described above. The fibrous powder as produced has a bulk density of 0.00
Since it is very small, 5 g / cm 3 or less, it is first compression molded. The fibrous powder can be molded into any shape by selecting a mold and a compression method. For example, the shape is a cylinder, a cube, a rectangular parallelepiped, a prism, a flat plate or the like, and other complicated shapes can be formed. However, industrially, it is desirable to use a cylinder or prism so that the shape is as simple as possible and that electricity can be easily supplied from both sides (both ends).
【０００９】成形方法はプレス成形法や押出し成形法が
最も容易である。繊維状粉末は各繊維の絡みがよく、ま
たタール分が少量含まれているので、そのまま圧縮成形
しただけでも通電加熱に支障ない程度に形状が保持され
るが、さらに高い強度を望む場合は繊維状粉末に澱粉、
ＣＭＣ、タール、ナフタレン、アントラセン等の１次結
合材を少量添加して成形すればよい。As the molding method, the press molding method and the extrusion molding method are the easiest. Since the fibrous powder has good entanglement of each fiber and contains a small amount of tar, the shape can be retained even if compression molding is performed as it is so as not to interfere with electric heating, but if higher strength is desired, the fiber can be Star-shaped powder,
It may be molded by adding a small amount of a primary binder such as CMC, tar, naphthalene or anthracene.
【００１０】成形体の強度は、成形時の加圧圧力と繊維
状粉末の嵩密度によって調整できるので目的とする成形
体の強度、目標の嵩密度によって最適な圧力条件を選定
する。具体的には０．１ｋｇ／ｃｍ2 以上あればよい。
圧力は高いほどしっかりした成形品が得られるが高くな
りすぎると繊維の崩壊を起こし繊維特性が低下する。即
ち加圧圧力が０．１ｋｇ／ｃｍ2 より小さくなると、成
形品の強度が不十分で取扱中に崩壊して粉化する確率が
高くなる。一方１００ｋｇ／ｃｍ2 以上の圧力になると
繊維の切断や崩壊が多くなり繊維特性が悪くなる。また
加圧圧力が高くなると金型を始め加圧システム自体の設
備費が高くなるので設備面コストから見ても圧力は低い
方が好ましい。従って成形圧力としては０．１〜１００
ｋｇ／ｃｍ2 程度、好ましくは１〜１０ｋｇ／ｃｍ2 程
度がよい。Since the strength of the molded body can be adjusted by the pressure applied during molding and the bulk density of the fibrous powder, the optimum pressure condition is selected according to the strength of the target molded body and the target bulk density. Specifically, it may be 0.1 kg / cm 2 or more.
When the pressure is higher, a solid molded product can be obtained, but when the pressure is too high, the fibers are collapsed and the fiber characteristics are deteriorated. That is, when the pressurizing pressure is less than 0.1 kg / cm 2 , the strength of the molded product is insufficient and the probability of disintegration and powdering during handling increases. On the other hand, when the pressure is 100 kg / cm 2 or more, the fibers are often cut or broken and the fiber characteristics are deteriorated. Further, since the equipment cost of the pressurizing system itself including the mold becomes high when the pressurizing pressure becomes high, it is preferable that the pressure is low in view of the equipment cost. Therefore, the molding pressure is 0.1-100
kg / cm 2 or so, preferably from about 1 to 10 kg / cm 2.
【００１１】成形圧力が０．１ｋｇ／ｃｍ2 以上であれ
ば成形体は嵩密度が通常０．０３ｇ／ｃｍ3 以上とな
る。しかし繊維状粉末の成形体は圧力が開放されると多
少復元する性質があるので通電加熱する際にはこれを考
慮する必要がある。本発明においては成形体の嵩密度は
通電加熱時において０．０３ｇ／ｃｍ3 以上とする。こ
の密度であれば電気比抵抗は１００Ωｃｍ以下となる。
成形体の通電加熱は例えば図１のような方法で行なう。
図において１は繊維状粉末の成形体でその嵩密度は０．
０３ｇ／ｃｍ3 以上である。２は成形体の上下の電極で
導体４′により電源４に接続されている。電極は導電性
がよくかつ高温に耐える炭素電極が最も適する。３はセ
ラミックス等の絶縁体である。通電加熱は非酸化性雰囲
気下で行なう必要があり、また成形体よりガスが発生す
るので通電部を筐体５で囲み、筐体５に窒素ガス、アル
ゴンガス等の導入口６及びガス排出口７を設ける。When the molding pressure is 0.1 kg / cm 2 or more, the bulk density of the molded product is usually 0.03 g / cm 3 or more. However, since the fibrous powder compact has a property of recovering to some extent when the pressure is released, this must be taken into consideration when electrically heating. In the present invention, the bulk density of the molded product is set to 0.03 g / cm 3 or more during electric heating. With this density, the electrical resistivity is 100 Ωcm or less.
The electric heating of the molded body is performed, for example, by the method shown in FIG.
In the figure, 1 is a fibrous powder compact, and its bulk density is 0.
It is at least 03 g / cm 3 . Reference numeral 2 denotes upper and lower electrodes of the molded body, which are connected to a power source 4 by a conductor 4 '. The most suitable electrode is a carbon electrode having good conductivity and withstanding high temperature. Reference numeral 3 is an insulator such as ceramics. It is necessary to perform the energization heating in a non-oxidizing atmosphere, and since gas is generated from the molded body, the energizing part is surrounded by the housing 5, and the housing 5 is provided with an inlet 6 for gas such as nitrogen gas and argon gas and a gas outlet. 7 is provided.
【００１２】成形体に負荷する圧力は上部の電極に取付
けた保持装置（図示せず）により調整できるようにす
る。電極と成形体の接触をよくし、かつ成形体の嵩密度
が０．０３ｇ／ｃｍ3 となっておれば圧力は殆ど負荷し
なくても通電は可能であるが好ましくは１００ｇ／ｃｍ
2 以上に加圧して通電する。成形体の加圧力は高過ぎる
と崩壊するので通常上限は１００ｋｇ／ｃｍ2 程度であ
る。通電加熱は繊維状粉末を成形したままのものでもよ
く、またその成形体を一旦外熱法で可能な温度で加熱し
たものでもよい。成形したままのものは急速加熱すると
ガスの発生が激しいのでゆっくり加熱することが好まし
い。通電加熱は黒鉛化のような高温処理に特に有効であ
る。２５００℃以上の高温処理の際には電極間の電圧が
高いと熱放電のおそれがあるので、あまり電圧は高くし
ない方がよく、例えば２０Ｖ以下程度が好ましい。この
電圧でも必要な発熱が得られるように成形体の断面積、
高さ等を調整する。熱処理のための加熱温度は１３００
℃位から３０００℃前後の範囲で通常選ばれる。The pressure applied to the molded body can be adjusted by a holding device (not shown) attached to the upper electrode. If the contact between the electrode and the molded body is good and the bulk density of the molded body is 0.03 g / cm 3 , it is possible to energize with almost no pressure, but preferably 100 g / cm.
Energize by applying a pressure of 2 or more. Since the pressing force of the molded body will collapse if it is too high, the upper limit is usually about 100 kg / cm 2 . The electric heating may be carried out by molding the fibrous powder as it is, or by heating the molded body once at a temperature which can be carried out by the external heating method. It is preferable to heat the as-molded product slowly because rapid generation of gas causes severe gas generation. Electric heating is particularly effective for high temperature treatment such as graphitization. In the case of high temperature treatment of 2500 ° C. or higher, if the voltage between the electrodes is high, heat discharge may occur. Therefore, it is better not to increase the voltage so much, for example, about 20 V or less is preferable. The cross-sectional area of the molded body so that the required heat generation can be obtained even at this voltage,
Adjust height etc. The heating temperature for heat treatment is 1300
It is usually selected in the range from about ℃ to about 3000 ℃.
【００１３】図２は成形体を電気絶縁性の型８内で通電
加熱する方法を示す。成形体１は別に成形したものを型
８に入れてもよく、またこの型で成形し、続いて通電す
ることもできる。図２の方法では成形体が崩壊すること
がないので目的とする温度における型の耐圧力の範囲で
加圧力を高めることが可能である。しかし、絶縁性の型
としてはアルミナ等のセラミックスが用いられるが、加
熱温度は１８００℃程度が限度である。FIG. 2 shows a method of electrically heating a molded body in an electrically insulating mold 8. The molded body 1 may be separately molded and placed in the mold 8, or the molded body 1 may be molded and subsequently energized. In the method of FIG. 2, since the molded body does not collapse, it is possible to increase the pressing force within the range of the pressure resistance of the mold at the target temperature. However, although ceramics such as alumina are used as the insulating mold, the heating temperature is limited to about 1800 ° C.
【００１４】図３は成形装置と通電加熱装置を直結し、
成形と通電加熱を連続的にできるようにしたものであ
る。生成した繊維状粉末はホッパー９内に一時収容す
る。ホッパーの下部にシリンダー１０とプランジャー１
１からなる成形装置を設置する。１１′はプランジャー
の駆動装置である。ホッパーから繊維状粉末を所定量シ
リンダー内に落しプランジャーで圧縮成形する。粉末の
落下量はホッパー下部のフィダー９′で定量的に調整す
るのが好ましい。繊維状粉末は圧縮すると体積が非常に
小さくなるので所定の成形体にするには落下した粉末を
受ける部分の容積を十分大きくするかあるいは粉末の落
下と予備圧縮を繰り返し、最後に所定の成形体に圧縮す
る方法などを採用する。前者の場合はシリンダーに直角
方向（紙面に垂直方向）に空間を設け、そこに落下した
粉末をシリンダーに直角方向に作動するプランジャー
（図示してない）でシリンダーと同じ位置まで圧縮し、
次いで図示のプランジャー１１で圧縮するなどの方法が
可能である。図示のシリンダーは断面が四角であるがシ
リンダーが円筒の場合は直角方向のプランジャーの先端
をシリンダーに合せた半円形とする。In FIG. 3, the molding device and the electric heating device are directly connected,
The molding and the electric heating can be continuously performed. The generated fibrous powder is temporarily stored in the hopper 9. Cylinder 10 and plunger 1 at the bottom of the hopper
A molding device consisting of 1 is installed. 11 'is a drive device for the plunger. A predetermined amount of fibrous powder is dropped from the hopper into the cylinder and compression molded with a plunger. It is preferable that the amount of powder dropped is quantitatively adjusted by a feeder 9'under the hopper. Since the volume of fibrous powder becomes very small when compressed, the volume of the part that receives the dropped powder should be made sufficiently large to make it a prescribed compact, or the dropping and pre-compression of the powder should be repeated, and finally the prescribed compact. The method of compressing is adopted. In the case of the former, a space is provided in the cylinder at a right angle (perpendicular to the paper surface), and the powder that falls there is compressed to the same position as the cylinder with a plunger (not shown) that operates in a direction perpendicular to the cylinder.
Then, a method such as compression with the illustrated plunger 11 is possible. The illustrated cylinder has a square cross section, but when the cylinder is a cylinder, the tip of the plunger in the right angle direction is a semicircle with the cylinder fitted.
【００１５】シリンダーの底部は開閉ダンパー１２がそ
の保持装置１３内を駆動装置１２′によりスライドする
ようになっている。保持装置は中央部分がシリンダーと
同一の穴を有している。成形時はダンパーを閉とし、成
形終了後ダンパーを開にし、成形体をプランジャーで押
出す。成形体は次に通電加熱するのがその方法は前記図
１の場合と本質的な変りはない。加熱が終了した成形体
は受け器１４内に収容する。At the bottom of the cylinder, an opening / closing damper 12 is slidable in a holding device 13 thereof by a driving device 12 '. The holding device has a hole in the center that is the same as the cylinder. The damper is closed during molding, the damper is opened after the molding is completed, and the molded body is extruded by the plunger. Next, the molded body is electrically heated, and the method is essentially the same as in the case of FIG. The molded body that has been heated is housed in the receiver 14.
【００１６】図４は成形体が通電加熱される前に外熱法
による加熱（焼成）領域を設けた方法を示す。その他は
図３と変りはない。ダンパーから出た成形体は加熱装置
１６を備えた炉芯管１５内に入り、そこで焼成される。
炉芯管は成形体が充填されていてもガスが通るように成
形体より太くする。炉芯管による焼成及び通電加熱にお
いてガスが発生するが、これらのガスは導入される窒素
ガス６等により通電加熱室から炉芯管内を通り、排出口
７より出るが、そのガスの揮発分を凝縮、吸着、吸収等
の方法で除いてリサイクル使用することも可能である。
この装置では炉芯管による焼成は１８００℃程度以下と
し、その後通電により３０００℃位まで加熱することが
できる。以上の図示の方法は成形体を上下より電極で挟
んで縦に通電しているが、左右から横方向に通電するこ
とも勿論可能である。FIG. 4 shows a method in which a heating (sintering) region is provided by an external heating method before the molded body is electrically heated. Others are the same as those in FIG. The molded body exiting from the damper enters the furnace core tube 15 equipped with the heating device 16, and is fired there.
The furnace core tube is made thicker than the molded body so that gas can pass through even when the molded body is filled. Gas is generated during firing by the furnace core tube and electric heating, and these gases pass through the furnace core tube from the electric heating chamber by the nitrogen gas 6 introduced into the furnace core tube and exit from the discharge port 7. It can be recycled for use except by condensation, adsorption, absorption or the like.
In this apparatus, the firing by the furnace core tube is set to about 1800 ° C. or lower, and thereafter, it can be heated to about 3000 ° C. by energizing. In the method shown above, the molded body is sandwiched between the electrodes from above and below, and the electrodes are energized vertically, but it is of course possible to energize laterally from the left and right.
【００１７】[0017]
［実施例１］繊維状粉末として各繊維の大部分が直径
０．０５〜３μｍ、長さが２〜１００μｍの範囲にある
ものを用い、図３の装置によりその成形体に通電加熱し
た。シリンダーは断面が３０ｍｍ×３０ｍｍの角筒体で
ある。ホッパーから繊維状粉末をシリンダーに供給し、
５ｋｇ／ｃｍ2 の圧力で成形した。成形後ダンパー１２
を開とし、成形体を押出した。成形体の長さは５０ｍ
ｍ、嵩密度は０．０８ｇ／ｃｍ3 で、電気比抵抗は０．
４Ωｃｍであった。この成形体の３０×５０ｍｍの両面
を上下の黒鉛電極で挟み、５ｇ／ｃｍ2 の加圧で通電し
た。初期の電圧は２．５Ｖ、電流は１Ａで、徐々に電圧
を上げ、最終的には電圧を１５．２Ｖ、電流を１８．５
Ａとし、それまでのスタートからの時間は５分であっ
た。この最終的な電圧、電流の条件で１０分間保持し
た。成形体は約１４００℃となった。通電中は窒素ガス
を０．５リットル／分流した。冷却後成形体を取外し、
粉砕して気流分級器により粒状の炭素や鉄化合物を除き
製品とした。製品のＣｏは６．９２８Å、Ｌｃは５０Å
であった。[Example 1] As the fibrous powder, most of each fiber had a diameter of 0.05 to 3 µm and a length of 2 to 100 µm, and the molded body was electrically heated by the apparatus shown in Fig. 3. The cylinder is a rectangular cylinder having a cross section of 30 mm × 30 mm. Supply the fibrous powder from the hopper to the cylinder,
It was molded at a pressure of 5 kg / cm 2 . Damper 12 after molding
Was opened and the molded body was extruded. The length of the molded body is 50m
m, the bulk density is 0.08 g / cm 3 , and the electrical resistivity is 0.1.
It was 4 Ωcm. Both sides of 30 × 50 mm of this molded body were sandwiched between upper and lower graphite electrodes, and electricity was applied by applying a pressure of 5 g / cm 2 . The initial voltage is 2.5V, the current is 1A, and the voltage is gradually increased until the voltage is 15.2V and the current is 18.5.
It was A, and the time from the start up to that point was 5 minutes. The final voltage and current conditions were maintained for 10 minutes. The temperature of the molded body was about 1400 ° C. Nitrogen gas was flowed at 0.5 liters / minute during energization. After cooling, remove the molded body,
The product was pulverized to remove granular carbon and iron compounds by an air stream classifier to obtain a product. Product Co is 6.928Å, Lc is 50Å
Met.
【００１８】［実施例２］図４に示す装置で熱処理し
た。成形までは実施例１と同様である。成形体は先ず炉
芯管内に送り、熱処理した。炉芯管の最高温度領域は１
４００℃である。この領域での滞溜時間は１０分間であ
る。次に成形体を熱いまま通電加熱装置に移し実施例１
と同様に黒鉛電極に挟み５ｋｇ／ｃｍ2 の加圧下で通電
した。初期の電圧２．５Ｖ、電流１Ａで徐々に電圧を上
げ、最終的には電圧２０．３Ｖ、電流６１Ａとし、それ
までのスタートからの時間は１０分であった。最終的な
電圧、電流で１０分間保持した。成形体の温度は放射温
度計で推定３０１４℃であった。実施例１と同様に粉
砕、分級し製品とした。製品のＣｏは６．７６５Å、Ｌ
ｃは２８０Åでよく黒鉛化されていた。[Example 2] Heat treatment was performed using the apparatus shown in FIG. The process up to the molding is the same as in Example 1. The molded body was first sent into the furnace core tube and heat-treated. Maximum temperature range of furnace core tube is 1
It is 400 ° C. The retention time in this area is 10 minutes. Next, the molded body was transferred to an electric heating device while still hot, and Example 1
In the same manner as above, it was sandwiched between graphite electrodes and energized under a pressure of 5 kg / cm 2 . The voltage was gradually increased with an initial voltage of 2.5 V and a current of 1 A, and was finally set to a voltage of 20.3 V and a current of 61 A, and the time from the start until then was 10 minutes. The final voltage and current were held for 10 minutes. The temperature of the molded body was 3014 ° C. estimated by a radiation thermometer. The product was pulverized and classified in the same manner as in Example 1. The product Co is 6.765Å, L
c was 280Å and was well graphitized.
【００１９】[0019]
【発明の効果】嵩密度の小さい気相法炭素繊維の熱処理
は効率が悪かったが、本発明のように圧力を加えること
によって成形して得られた成形体の嵩密度が０．０３ｇ
／ｃｍ3 以上となり、成形体の電気比抵抗が１００Ωｃ
ｍ以下に出来たことによって気相法炭素繊維に通電加熱
できるようになった。この結果本発明では気相法炭素繊
維を容器に入れることなく短時間で連続的に効率よく熱
処理できるようになった。EFFECT OF THE INVENTION Although the heat treatment of vapor grown carbon fiber having a small bulk density was inefficient, the bulk density of the molded product obtained by molding by applying pressure as in the present invention was 0.03 g.
/ Cm 3 or more, the electrical resistivity of the molded body is 100 Ωc
By being able to make m or less, it became possible to electrically heat the vapor grown carbon fiber. As a result, according to the present invention, it becomes possible to continuously and efficiently heat treat the vapor grown carbon fiber in a short time without putting it in a container.
【図１】微細な気相法炭素繊維の成形体の通電加熱を示
す断面図。FIG. 1 is a cross-sectional view showing electric heating of a molded body of fine vapor grown carbon fiber.
【図２】図１における成形体を電気絶縁体の中に入れて
通電加熱する場合を示す断面図。FIG. 2 is a cross-sectional view showing a case where the molded body in FIG. 1 is put into an electric insulator and electrically heated.
【図３】微細な気相法炭素繊維を成形し、次いで通電加
熱を示す断面図。FIG. 3 is a cross-sectional view showing molding of fine vapor grown carbon fiber and subsequent heating by electric current.
【図４】図３における成形と通電加熱の間に外熱式の加
熱装置を設けた場合を示す断面図。FIG. 4 is a cross-sectional view showing a case where an external heating type heating device is provided between the molding and the electric heating in FIG.
１ 微細な気相法炭素繊維の成形体 ２ 電極 ４ 電源 ６ 不活性ガス導入口 ７ ガス排出口 ８ セラミックス絶縁体 ９ ホッパー ９′ フィダー １０ シリンダー １１ プランジャー １２ ダンパー １４ 受け器 １５ 炉芯管 １６ 加熱装置 1 Fine carbon fiber molded body 2 Electrode 4 Power supply 6 Inert gas inlet 7 Gas outlet 8 Ceramics insulator 9 Hopper 9'Fider 10 Cylinder 11 Plunger 12 Damper 14 Receiver 15 Furnace tube 16 Heating apparatus
Claims (6)
形体の嵩密度を０．０３ｇ／ｃｍ3 以上とし、該成形体
の両側に電極端子を当接し、成形体に通電加熱すること
を特徴とする気相法炭素繊維の熱処理方法。1. A fine vapor grown carbon fiber is compression-molded to have a bulk density of 0.03 g / cm 3 or more, an electrode terminal is brought into contact with both sides of the molded body, and the molded body is electrically heated. A heat treatment method for a vapor grown carbon fiber, which is characterized in that
載の気相法炭素繊維の熱処理方法。2. The heat treatment method for vapor grown carbon fiber according to claim 1, wherein the molded body is electrically heated in the mold.
型の成形装置で微細な気相法炭素繊維を成形し、成形後
シリンダーのダンパーを開とし、成形体をシリンダーか
ら押出し、該成形体の両側に電極端子を当接し、成形体
に通電加熱することを特徴とする気相法炭素繊維の熱処
理方法。3. A fine molding carbon fiber is molded by a cylinder type molding device having an opening / closing damper at the bottom, and after the molding, the damper of the cylinder is opened and the molded body is extruded from the cylinder. A method for heat treating a vapor grown carbon fiber, which comprises bringing an electrode terminal into contact with the electrode and heating the molded body by applying electricity.
型の成形装置で微細な気相法炭素繊維を成形し、成形後
シリンダーのダンパーを開とし、成形体をシリンダーか
ら押出してシリンダーに接続された炉芯管内に送り込
み、成形体を焼成し、次いで炉芯管から押出された成形
体の両側に電極端子を当接し、焼成成形体に通電加熱す
ることを特徴とする気相法炭素繊維の熱処理方法。4. A fine molding carbon fiber is molded with a cylinder type molding device having an opening / closing damper at the bottom, and after the molding, the damper of the cylinder is opened, and the molded body is extruded from the cylinder and connected to the cylinder. Heat treatment of vapor grown carbon fiber characterized by feeding into the furnace core tube, firing the molded body, then contacting electrode terminals on both sides of the molded body extruded from the furnace core tube, and electrically heating the fired molded body. Method.
ーの下部にシリンダー型成形装置を直結して該炭素繊維
の成形を行なう請求項３又は４記載の気相法炭素繊維の
熱処理方法。5. The heat treatment method for vapor grown carbon fiber according to claim 3, wherein a cylinder type molding apparatus is directly connected to the lower portion of the hopper accommodating the fine vapor grown carbon fiber to form the carbon fiber.
上の加圧下で行なう請求項１〜５のいずれかに記載の気
相法炭素繊維の熱処理方法。6. The heat treatment method for a vapor grown carbon fiber according to claim 1, wherein the current applied to the molded body is heated under a pressure of 100 g / cm 2 or more.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21667394A JP3600640B2 (en) | 1994-08-17 | 1994-08-17 | Heat treatment method of vapor grown carbon fiber |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21667394A JP3600640B2 (en) | 1994-08-17 | 1994-08-17 | Heat treatment method of vapor grown carbon fiber |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0860446A true JPH0860446A (en) | 1996-03-05 |
| JP3600640B2 JP3600640B2 (en) | 2004-12-15 |
Family
ID=16692137
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21667394A Expired - Fee Related JP3600640B2 (en) | 1994-08-17 | 1994-08-17 | Heat treatment method of vapor grown carbon fiber |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3600640B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002235279A (en) * | 2001-02-08 | 2002-08-23 | Showa Denko Kk | Vapor-grown carbon fiber coated with electrical insulator, method for producing the same, and use thereof |
| WO2004038074A1 (en) * | 2002-10-28 | 2004-05-06 | Bussan Nanotech Reserch Institute Inc. | Method and apparatus for heat treatment of powder of fine carbon fiber |
| WO2006100877A1 (en) * | 2005-03-22 | 2006-09-28 | Bussan Nanotech Research Institute Inc. | Carbon fiber conjugate and composite material using the same |
| JP2006335624A (en) * | 2005-06-06 | 2006-12-14 | Denso Corp | Method and apparatus for manufacturing carbon nanotube fiber |
| JP2007138338A (en) * | 2005-11-18 | 2007-06-07 | Bussan Nanotech Research Institute Inc | Composite material |
| WO2015108056A1 (en) | 2014-01-14 | 2015-07-23 | 昭和電工株式会社 | Lithium secondary battery and conductive assistant used in same |
-
1994
- 1994-08-17 JP JP21667394A patent/JP3600640B2/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002235279A (en) * | 2001-02-08 | 2002-08-23 | Showa Denko Kk | Vapor-grown carbon fiber coated with electrical insulator, method for producing the same, and use thereof |
| WO2004038074A1 (en) * | 2002-10-28 | 2004-05-06 | Bussan Nanotech Reserch Institute Inc. | Method and apparatus for heat treatment of powder of fine carbon fiber |
| WO2006100877A1 (en) * | 2005-03-22 | 2006-09-28 | Bussan Nanotech Research Institute Inc. | Carbon fiber conjugate and composite material using the same |
| JP2006265751A (en) * | 2005-03-22 | 2006-10-05 | Bussan Nanotech Research Institute Inc | Combined carbon fiber material and composite material produced by using the same |
| JP2006335624A (en) * | 2005-06-06 | 2006-12-14 | Denso Corp | Method and apparatus for manufacturing carbon nanotube fiber |
| JP2007138338A (en) * | 2005-11-18 | 2007-06-07 | Bussan Nanotech Research Institute Inc | Composite material |
| WO2015108056A1 (en) | 2014-01-14 | 2015-07-23 | 昭和電工株式会社 | Lithium secondary battery and conductive assistant used in same |
| KR20160098370A (en) | 2014-01-14 | 2016-08-18 | 쇼와 덴코 가부시키가이샤 | Lithium secondary battery and conductive assistant used in same |
| US10084190B2 (en) | 2014-01-14 | 2018-09-25 | Showa Denko K.K. | Lithium secondary battery and conductive assistant used in same |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3600640B2 (en) | 2004-12-15 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP3502490B2 (en) | Carbon fiber material and method for producing the same | |
| KR100226807B1 (en) | Microwave sintering process | |
| JP3461805B2 (en) | Carbon fiber, method for producing the same, and battery electrode | |
| JP4533146B2 (en) | Fine carbon fiber powder heat treatment method and heat treatment apparatus | |
| CZ292640B6 (en) | Method for increasing regularity of carbon particle nanostructure | |
| US4080413A (en) | Porous carbon fuel cell substrates and method of manufacture | |
| JP2004003097A (en) | Carbon fiber, process for producing the same and electrode for electric batteries | |
| JP3600640B2 (en) | Heat treatment method of vapor grown carbon fiber | |
| JP4920135B2 (en) | Electrical insulator-coated vapor-phase carbon fiber, method for producing the same, and use thereof | |
| JPH09502487A (en) | Graphite fibril material | |
| JP2004119386A (en) | Carbon fiber material and its composite material | |
| JP3153471B2 (en) | Carbon or graphite powder for negative electrode material of lithium battery and method for producing the same | |
| JPH01270543A (en) | Granulated carbon fiber by vapor process | |
| JP2003020527A (en) | Carbon fiber, method for producing the same and use thereof | |
| JP3609458B2 (en) | Heat treatment method and apparatus for fine carbon fiber | |
| JPH0214805A (en) | Production of expanded graphite and heating furnace for producing expanded graphite | |
| CA2510748A1 (en) | Nanostructures | |
| JPH09251855A (en) | Manufacture of carbon powder for negative electrode of lithium ton secondary battery | |
| KR101905701B1 (en) | Semi-continuous coating device for nanostructure and coating method using the same | |
| CN113574015A (en) | Heating furnace and method for producing graphite | |
| JPH0733420A (en) | Carbonaceous fine particles of special shape, compact of them and their production | |
| JP2006306724A (en) | Graphite carbon powder and method and apparatus for producing the same | |
| JP4552163B2 (en) | Manufacturing method of carbonaceous granular heat insulating material | |
| JP2808807B2 (en) | Production method of raw material powder for carbon material | |
| JPH1197017A (en) | Manufacture of charcoal material for electrode |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A131 | Notification of reasons for refusal |
Effective date: 20040622 Free format text: JAPANESE INTERMEDIATE CODE: A131 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20040726 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Effective date: 20040914 Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Effective date: 20040917 Free format text: JAPANESE INTERMEDIATE CODE: A61 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20100924 Year of fee payment: 6 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20130924 Year of fee payment: 9 |
|
| LAPS | Cancellation because of no payment of annual fees |