JPS6247968B2 - - Google Patents
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- Publication number
- JPS6247968B2 JPS6247968B2 JP57170207A JP17020782A JPS6247968B2 JP S6247968 B2 JPS6247968 B2 JP S6247968B2 JP 57170207 A JP57170207 A JP 57170207A JP 17020782 A JP17020782 A JP 17020782A JP S6247968 B2 JPS6247968 B2 JP S6247968B2
- Authority
- JP
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- Prior art keywords
- temperature
- manufacturing
- grinding
- ultrafine
- metal catalyst
- Prior art date
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- 239000000835 fiber Substances 0.000 claims description 40
- 238000006243 chemical reaction Methods 0.000 claims description 39
- 239000000758 substrate Substances 0.000 claims description 30
- 239000003054 catalyst Substances 0.000 claims description 29
- 239000002245 particle Substances 0.000 claims description 27
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 25
- 239000004917 carbon fiber Substances 0.000 claims description 25
- 239000002184 metal Substances 0.000 claims description 25
- 229910052751 metal Inorganic materials 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 24
- 230000003647 oxidation Effects 0.000 claims description 22
- 238000007254 oxidation reaction Methods 0.000 claims description 22
- 238000004519 manufacturing process Methods 0.000 claims description 20
- 238000000227 grinding Methods 0.000 claims description 19
- 239000006185 dispersion Substances 0.000 claims description 15
- 238000010438 heat treatment Methods 0.000 claims description 15
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 13
- 238000011282 treatment Methods 0.000 claims description 13
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 12
- 229930195733 hydrocarbon Natural products 0.000 claims description 10
- 150000002430 hydrocarbons Chemical class 0.000 claims description 10
- 229910052799 carbon Inorganic materials 0.000 claims description 8
- 239000001257 hydrogen Substances 0.000 claims description 8
- 229910052739 hydrogen Inorganic materials 0.000 claims description 8
- 239000007789 gas Substances 0.000 claims description 7
- 239000004215 Carbon black (E152) Substances 0.000 claims description 5
- 239000002612 dispersion medium Substances 0.000 claims description 5
- 239000007788 liquid Substances 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 5
- 239000002134 carbon nanofiber Substances 0.000 claims description 3
- 230000001590 oxidative effect Effects 0.000 claims description 3
- 239000000725 suspension Substances 0.000 claims description 2
- 125000004435 hydrogen atom Chemical class [H]* 0.000 claims 1
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 48
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 27
- 238000010899 nucleation Methods 0.000 description 14
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 12
- 230000008569 process Effects 0.000 description 10
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 230000000694 effects Effects 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 8
- 235000019441 ethanol Nutrition 0.000 description 7
- 239000002923 metal particle Substances 0.000 description 6
- 238000005245 sintering Methods 0.000 description 6
- 239000012159 carrier gas Substances 0.000 description 5
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 4
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 4
- 230000015572 biosynthetic process Effects 0.000 description 4
- 150000001722 carbon compounds Chemical class 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 229910001873 dinitrogen Inorganic materials 0.000 description 4
- 238000005507 spraying Methods 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- GVEPBJHOBDJJJI-UHFFFAOYSA-N fluoranthene Chemical group C1=CC(C2=CC=CC=C22)=C3C2=CC=CC3=C1 GVEPBJHOBDJJJI-UHFFFAOYSA-N 0.000 description 3
- 230000006911 nucleation Effects 0.000 description 3
- 239000011882 ultra-fine particle Substances 0.000 description 3
- 239000012808 vapor phase Substances 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 229910052786 argon Inorganic materials 0.000 description 2
- WDECIBYCCFPHNR-UHFFFAOYSA-N chrysene Chemical group C1=CC=CC2=CC=C3C4=CC=CC=C4C=CC3=C21 WDECIBYCCFPHNR-UHFFFAOYSA-N 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- -1 ethylene, propylene Chemical group 0.000 description 2
- 238000007380 fibre production Methods 0.000 description 2
- 239000010419 fine particle Substances 0.000 description 2
- 229910002804 graphite Inorganic materials 0.000 description 2
- 239000010439 graphite Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- YNPNZTXNASCQKK-UHFFFAOYSA-N phenanthrene Chemical group C1=CC=C2C3=CC=CC=C3C=CC2=C1 YNPNZTXNASCQKK-UHFFFAOYSA-N 0.000 description 2
- BBEAQIROQSPTKN-UHFFFAOYSA-N pyrene Chemical group C1=CC=C2C=CC3=CC=CC4=CC=C1C2=C43 BBEAQIROQSPTKN-UHFFFAOYSA-N 0.000 description 2
- 239000010453 quartz Substances 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- XDTMQSROBMDMFD-UHFFFAOYSA-N Cyclohexane Chemical compound C1CCCCC1 XDTMQSROBMDMFD-UHFFFAOYSA-N 0.000 description 1
- 239000004593 Epoxy Substances 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 230000002776 aggregation Effects 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- MWPLVEDNUUSJAV-UHFFFAOYSA-N anthracene Natural products C1=CC=CC2=CC3=CC=CC=C3C=C21 MWPLVEDNUUSJAV-UHFFFAOYSA-N 0.000 description 1
- 125000005577 anthracene group Chemical group 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 150000001721 carbon Chemical class 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 125000004122 cyclic group Chemical group 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000012770 industrial material Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000005360 mashing Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 239000002609 medium Substances 0.000 description 1
- 150000001247 metal acetylides Chemical class 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- PXHVJJICTQNCMI-UHFFFAOYSA-N nickel Substances [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 125000003367 polycyclic group Chemical group 0.000 description 1
- 229910052573 porcelain Inorganic materials 0.000 description 1
- 239000012255 powdered metal Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229920001187 thermosetting polymer Polymers 0.000 description 1
- 238000001132 ultrasonic dispersion Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 239000000341 volatile oil Substances 0.000 description 1
Description
【発明の詳細な説明】
本発明は、気相法による炭素繊維の製造法の改
良に関する。
気相法による炭素繊維の製造方法については、
いろいろな研究者によつて研究がなされている。
例えば特公昭41−12091、特開昭52−103528、特
公昭53−7538などでは、炭化水素を微粉末金属触
媒の存在下に気相で炭素繊維を生成させる方法が
例示されている。特に最近、学術振興会第８回年
会（昭和56年）、特開昭57−117622、工業材料、
第30巻、第７号、第109〜115頁などで、平均粒径
500Å以下の超微粉粒触属（鉄、鉄−ニツケル合
金など）を高純度アルコールに懸濁せしめ、これ
を耐熱性基板にスプレーして繊維生成核の
Seeding（種まき）を行ない、この基板を1000℃
付近に保持し炭化水素（ベンゼンなど）と水素の
混合ガスを導入することによつて基板上に多量の
炭素繊維を生成させる超微粒金属Seeding法が発
表された。
本発明者等はSeeding及び生成条件に関し鋭意
研究の結果、従来の方法に更に金属超微粒触媒の
摩砕分散および加熱酸化ならびに反応開始時の急
速昇温降温の手段を加えることが再現性良く炭素
繊維の生成とその発生密度を高めるものであるこ
とを知り、本発明に到つた。
さらに本発明者らは炭素繊維の製造において
は、繊維の太さ、長さおよび発生密度が問題とな
るが、Seeding法における繊維の成長過程の考察
から、一般に繊維の太さについては炭素種からの
炭素核発生とその成長条件が効率良く選ばれれ
ば、それに引き続き炭化水素の濃度を増加させる
か、または反応温度を上げるか、または滞留時間
を延ばすかなどによつて容易に達成できるもので
ある以上、炭素核発生とその成長条件をいかに選
ぶかが炭素繊維製造の基本であると考え、素繊維
の発生密度を高めることを目的として本発明に到
つたものである。
超微粒金属Seedingによる気相法で炭素繊維を
生成させるには、既に知られているように、電気
炉などを用いて所定の温度に加熱された耐熱性反
応管に炭化水素蒸気をキヤリアガスで希釈して導
き、高純度アルコールなどの分散媒にけん濁して
スプレーなどの方法で平均粒径500Å以下の金属
超微粒子を分散させた耐熱性基材上に炭素繊維を
生成させている。ここで反応管は通常アルミナ
質、石英等、加熱温度は800〜1300℃、炭化水素
としてはベンゼン、トルエン、メタン、エタン、
プロパン、ブタン、エチレン、プロピレン、シク
ロヘキサンなど飽和あるいは不飽和の脂肪族、芳
香族あるいはアンスラセン、フエナンスレン、ク
リセン、フルオランスレン、ピレンなどの２環以
上の縮合多環構造を有する炭化水素が使用可能で
あり、これらの混合物や揮発油あるいは灯油など
も使用可能である。
キヤリアガスとしては水素、窒素、アルゴンな
どの炭素に対して非酸化性の不活性ガス単独、又
は水蒸気、炭酸ガスなどの800℃で炭素に対して
酸化性または反応性を示す活性ガスを少量添加し
ても用いられ、また反応管内に置かれる耐熱性基
板には黒鉛、石英、またはアルミナ質のものが知
られている。炭素核生成用金属としてはFe、
Co、Niなどの周期律表の第族、Ｖ、Nb等の第
ｂ族の元素またはその炭化物、酸化物などの化
合物が用いられる。これらの金属の超微粒子は、
たとえば金属をヘリウムあるいはアルゴンなどの
雰囲気下で加熱して蒸発させ、これを媒状に凝縮
する方法（ガス中蒸発法）によつて得られる。
これら市販金属超微粉は表面が緻密な酸化皮膜
で覆われているのが通常であり、水またはエチル
アルコールに入れて振盪撹拌してもほとんどが凝
集塊となつて沈降し、極めて凝集しやすいもので
ある。
Seeding法による気相成長炭素繊維の生成機構
は、たとえば鉄超微粒子触媒を用いた場合、酸化
鉄の還元で生成された微小鉄粒子が液滴状で基板
表面に存在し、この液滴表面に炭素種（多環芳香
族的物質）が供給され、この炭素種が表面拡散を
へながら縮合過程を進めて炭素固体に変化して行
き、基板−液滴状粒子の界面部で垂直方向に炭素
層面が形成され、やがて粒子は押し上げられて繊
維が成長するものとされている。この反応過程は
液滴表面のみでなされ、中空チユーブが形成され
ることが、生成した炭素繊維の透過型電子顕微鏡
による観察で認められている。繊維の形成は、液
滴表面における炭素種の拡散が上記の炭素種の縮
合度や液滴表面への炭素供給速度を制限すること
になるので、炭素種の種類（Ｃ／Ｈ比など）や触
媒粒子径は勿論、雰囲気の温度や炭化水素分圧に
よつて敏感に影響される。従つて金属触媒粒子の
Seedingを効果的に行ない生成条件をコントロー
ルすれば、繊維の発生密度やその太さ、長さある
いはその均質性の制御を極めて簡単なプロセスで
かつ工業的な規模で実施可能としている。ここで
効果的なSeedingとは、例えば鉄の場合、粒子径
が300Å以下で基板上への粒子の分散については
アルコールなどの揮発性の分散媒にけん濁させて
スプレーなどにより散布、乾燥して基板上に弧立
した状態で分散させ、極めてわずかの量でよい。
キヤリアガスとして水素を用いる場合は、触媒
は環元されて金属元素として作用するものであ
る。Seedingからの核生成後の炭素繊維の形成
は、先づ長さ方向の成長が行われ（素繊維の成長
過程）、続いて太さ方向の成長（太さ成長過程）
が別々に起る（特開昭57−117622第140頁下段左
欄第４節）とされている。
素繊維の成長過程では、太さ成長過程よりも炭
化水素蒸気濃度および加熱温度を低くし、反応管
断面平均流速を速くすることができるとし、キヤ
リアガス中の水素濃度あるいは反応時間などにつ
いても好ましい範囲についての記載がなされてい
る。
しかしながら、これら従来の方法に従つて行つ
たが、繊維の生成とその発生密度は不充分であつ
た。本発明者らは再現性のよい繊維の生成とその
発生密度を高めるための方法について検討したと
ころ、触媒である金属超微粒子の分散状態および
その表面状態に大きく影響されることを知り、金
属超微粒子を予め摩砕処理することおよび空気雰
囲気下に加熱処理することが極めて効果的である
ことを見出した。水あるいはエチルアルコールを
分散媒として市販の鉄超微粉（平均粒径100Å、
真空冶金(株)製）0.3重量％となるように混合した
ものについて擂潰及び超音波による振動撹拌を別
個にしたが、後に述べるように繊維の生成実験に
よれば超音波分散では不十分で、500Åのような
超微粉の凝集を解離させるためには、直接微粒子
自体に擂潰作用を及ぼすボールミルのような摩砕
粉砕方式が有効であることが判つた。
本発明実施例では摩砕装置としてボールミルを
用いたが、上記の目的に適する装置としては超微
粉体の粉砕用として一般に用いられるチユーブミ
ル、振動ボールミル、コニカルボールミルの他、
擂潰機も用いることができる。
しかし、分散の良いけん濁液のSeedingによつ
ても繊維の生成密度がまばらになり、長さも短か
いものしか得られず不十分である。その原因は、
鏡検によると鉄超微粉が焼結を起こしており、生
成する繊維も成長初期から太くなつており、
Seeding液の調製時に触媒粒子の分散を良くして
も、炉内での昇温の途中に焼結を起こすために生
成の状態が悪くなるものとみられる。
さらに金属超微粉触媒の表面には３〜４原子層
の緻密な酸化皮膜（鉄超微粉の場合Fe3O4）がそ
の製造過程で形成されるとしており、この表面構
造が前記の粒子の焼結に影響を及ぼすと考えられ
る。本発明者らは粒子表面の改質を目的として、
鉄超微粉を空気雰囲気での低温酸化により粗鬆な
結晶構造を示すFe2O3を粒子表面に形成させた。
電子顕微鏡により、低温酸化直後および反応温度
まで昇温後の状態を観察したところ、粒子の分散
が良く粒子同志の焼結も抑えられていることが判
つた。更に低温酸化処理をした上で炭素繊維の生
成実験を行なつたところ、繊維の発生密度は一段
と増加し生成量も増加した。
なお上述の説明は鉄について述べたが、本発明
に用いることのできる周知の金属に対して、金属
超微粉の低温酸化の効果は、基板上に散布された
金属超微粒子のバルク層の表面にある粒子表面が
金属に固着しない粗鬆な金属酸化物のスケール、
あるいは結晶粒間の酸化による金属の脆化が起こ
り、好ましい単一球モデルに近い弧立した金属触
媒粒子の分散状態を与えるものと考えられる。
低温酸化温度は150℃近辺から酸化が起こり、
400℃、600℃、800℃と温度を上げる程、触媒粒
子の焼結が進み、生成密度も低くなるが、生成密
度が低下しない最適の酸化条件は300℃〜600℃、
30分である。
金属超微粉の摩砕分散と低温酸化処理の操作順
序は、後に示す実施例２と実施例３の結果から、
摩砕分散後基板上で酸化処理する方が顕著な効果
を示すことが判つた。摩砕前に加熱酸化すると、
凝集している超微粒子同志の焼結が起こりやす
く、その後の摩砕分散では十分に分散できないと
考えられる。一方摩砕して基板上に分散した後、
加熱酸化した場合は超微粒子同志の焼結が起こり
にくいと考えられる。
低温酸化処理と併せて金属結晶粒界への黒鉛質
の析出、いわゆる炭素核生成を促進する目的で反
応管内温度を所定の反応温度まで上げ、炭化水素
蒸気を導入すると同時に所定の反応温度よりも30
〜100℃、10分程度の短時間で上昇させ所定の反
応温度まで温度が上昇したところで直ちに元の反
応温度まで５分程度でもどす処理をしたところ、
炭素繊維の生成密度を大きくする効果のあるとこ
ろを見出した。急速昇温の温度は多くの実験の結
果、30℃未満では効果がなく、100℃よりも高く
しても効果が飽和して不経済であることが判つ
た。
以下、実施例を挙げて本発明を詳細に説明する
が、本発明はこれらに限定されるものではない。
実施例 １
第１図に示す温度調節のできる加熱部長さ400
mmのシリコンカーバイト系（商品名シリコニツ
ト）加熱体を有する電気炉６，８，９，１０に長
さ1000mm、外径50mm、内径42mmのアルミナ製反応
管７を設置し、その中に反応管より細い長さ300
mm、外径37mm、内径30mmのアルミナ管を縦に半割
りにした基板５に触媒をSeedingし、上下に位置
するように夫々の半割り基板を合わせて反応管中
央部に挿入した装置を用いて、本発明を実施し
た。
先づ、平均粒径100Åの鉄超微粉（真空冶金(株)
製）を0.3重量％の濃度で高純度エチルアルコー
ル200ml中に混合し、磁器製ボールミル粉砕機
（シエル外径98mm、シエル内径84mm、長さ90mm、
内部充填磁製ボール：径20mm25箇および径15mm25
箇、ボール総重量587ｇ）を100r.p.m.で回転させ
24時間摩砕して、鉄超微粒子がエチルアルコール
中に分散けん濁したスプレー用触媒分散液を調製
した。
これを半割りにした上記基板５内壁に0.5ml均
一にスプレーし、反応器７内に夫々触媒分散液を
スプレーした２箇の半割り基板を上下に合わせて
管状に組立てて反応管中央部に装入した。続いて
空気を300c.c.／minで反応管の１端から他端に向
けて流通させながら反応管内温度が400℃になる
まで加熱し、その温度で30分間保持した（加熱酸
化）。引き続いて、空気を窒素ガスに切り換えて
反応管内温度を900℃まで上昇させた。ここで窒
素ガスを水素ガスに切り換えて70c.c.／minとし、
反応管内温度を1000℃まで昇温した。ここでベン
ゼン蒸気が1.2容量％になるように、原料ベンゼ
ン容器２内のベンゼン温度を恒温槽３の温度調節
により5.5℃に維持しながら、水素ガスをキヤリ
アガスとして反応管に導入し反応を開始した。水
素ガスはベンゼン容器２内には19c.c.／min、バイ
パスラインには51c.c.／minを流して、反応管に入
る前でベンゼン濃度が1.2容量％になるようにし
た。
反応開始後、この1000℃の温度と1.2容量％の
ベンゼン濃度で30分間保持した（素繊維の成長過
程）。次に水素のバイパラスラインへの流通を止
め、水素は全量ベンゼン容器内を流通するように
して、反応管内温度を1100℃まで上げるとともに
ベンゼン濃度を7.5容量％（ベンゼン容器内ベン
ゼン温度15℃）まで30分をかけて増加させ、続い
てこの状態を１時間保持した（繊維の太さ成長過
程）。続いて電気炉の電源を遮断し、水素ガスと
ベンゼン蒸気との混合ガスを室温の窒素ガスに切
り換えて基板を冷却した。
以上の操作により繊維長約50mm、最大長さ約
100mmで繊維径約10μｍの炭素繊維が0.46ｇ得ら
れた。この時の供給全ベンゼン量に対する炭素繊
維の収率は、重量基準で28％であつた。基板円周
５mm長さあたり基板の長手方向に集束している炭
素繊維の全本数（発生密度）は1304本であつた。
繊維発生密度の測定は本発明全体を通して次の
方法によつた。
反応管内に置かれた半割基板の下側部分の中央
内壁部分に生成した炭素繊維層をカツターナイフ
で該基板内壁から剥ぎ取り、剥ぎ取つた炭素繊維
層から基板円管の半径方向の断面に存在する炭素
繊維の本数を数えるが、測定は上記炭素繊維層を
鋭利な鋏で適当な大きさに切り取りこれを型枠の
中に固定して、硬化した後にも透明性を失わない
ような例えばエポキシ系熱硬化性樹脂を型枠の中
に流し込んで固化せしめ鏡検用試料とする。この
試料を顕微鏡で撮影し、最終的には125倍に拡大
した写真として、その写真上で基板管壁円周方向
長さ５mmの管半径方向断面に存在する炭素繊維の
本数を数える。
比較例 １
実施例１の操作で鉄超微粉を分散媒液中で摩砕
するだけで酸化処理をしない場合、得られた炭素
繊維の繊維長は実施例１と同様であつたが、繊維
径は太目の約15μｍとなつた。繊維の発生密度は
302本で極めて生成効率の悪い結果しか得られな
かつた。また収率は7.5％であつた。このことか
ら実施例１の酸化処理が著しい効果を奏するもの
であることが判つた。
実施例 ２
実施例１の操作の途中に次の急速昇温降温操作
を加えた。すなわち、反応管内温度を反応温度
1000℃から1040℃まで約10分間で昇温し、その温
度に到達後直ちに反応温度1000℃まで降温させ
た。降温には約５分を要した。
本実施例は、実施例１の金属触媒の摩砕分散後
の加熱酸化処理に加えて反応開始時の急速昇温降
温操作を実施し、引き続き実施例１と同様の素繊
維の成長とその太さ成長の操作を実施したもので
あるが、得られた炭素繊維は繊維径および繊維長
は実施例１と同様であつたが、収率は32％、繊維
の発生密度は1482本となり、急速昇温降温処理を
併用することが有効であることが判つた。
比較例 ２
基板へのスプレー用触媒分散液の調製に実施例
１で述べたボールミルによる摩砕分散に替えて超
音波洗浄器（ヤマト科学(株)製、型番Ｂ−32）を用
いて、発振周波数45KHzの超音波を１時間放射し
て振動撹拌し、その他の操作は実施例２と同様に
処理して炭素繊維を作つた。
得られた繊維の長さは実施例２と同様であつた
が、繊維径は約15μｍと太目のものとなり、繊維
の発生密度は261本と極めて少なかつた。収率は
9.5％であつた。
実施例 ３
実施例２の操作中、金属超微粉触媒の酸化処理
を高純度エチルアルコール中で摩砕処理する前に
実施した場合の効果を比較するため、先づ実施例
１と同じ平均粒径100Åの市販鉄超微粉約１ｇを
磁性灰皿（灰分測定用）に入れて、実施例１記載
の装置を用いて空気を300c.c.／minで反応管内に
貫流させて400℃で30分間保持して該鉄触媒を酸
化した。
酸化終了後、該磁性灰皿を炉外に取出し冷却し
て、該酸化済鉄触媒を用いて実施例１記載と同様
の摩砕によるスプレー用触媒分散液の調製および
基板上への触媒分散液のスプレー分散および窒素
ガス雰囲気下ならびに水素ガス雰囲気下の反応管
内温度の上昇を行つた。引き続きベンゼン蒸気を
水素ガスキヤリアにより反応を開始し、以降は実
施例２記載と同様の急速昇温降温の処理と素繊維
の長さ成長と太さ成長の操作を行つた。
これによつて得られた炭素繊維は、繊維径およ
び繊維長は実施例１又は実施例２と同様であつた
が、収率は16％、繊維の発生密度は735本とな
り、実施例２の鉄超微粉の摩砕後の基板上での酸
化処理操作に較べて繊維の発生は少ないが、比較
例より大であつた。
第１表に一括して示した以上の実施例および比
較例の結果から、本発明の方法がすぐれているこ
とが明らかである。
【表】DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a method for producing carbon fiber by a vapor phase method. Regarding the method of manufacturing carbon fiber using the vapor phase method, please refer to
Research is being conducted by various researchers.
For example, Japanese Patent Publications No. 41-12091, No. 52-103528, and No. 53-7538 exemplify a method of producing carbon fibers from hydrocarbons in the gas phase in the presence of a finely powdered metal catalyst. Particularly recently, the 8th Annual Meeting of the Japan Society for the Promotion of Science (1982), JP-A-117622, Industrial Materials,
Volume 30, No. 7, pp. 109-115, etc., the average particle size
Ultrafine particles (iron, iron-nickel alloy, etc.) of 500 Å or less are suspended in high-purity alcohol and sprayed onto a heat-resistant substrate to form fiber nuclei.
Perform seeding and heat this substrate to 1000℃.
An ultrafine metal seeding method was announced in which a large amount of carbon fibers are produced on a substrate by holding the substrate nearby and introducing a mixed gas of hydrocarbons (such as benzene) and hydrogen. As a result of intensive research on seeding and production conditions, the present inventors found that it is possible to improve reproducibility by adding means of grinding and dispersing ultrafine metal catalysts, heating oxidation, and rapid temperature rise and fall at the start of the reaction to the conventional method. We found that this method increases the production of fibers and their density, and arrived at the present invention. Furthermore, in the production of carbon fibers, the thickness, length, and generation density of the fibers are issues, but from consideration of the fiber growth process in the seeding method, we found that the thickness of the fibers is generally determined from the carbon species. If the conditions for generating carbon nuclei and their growth are efficiently selected, this can be easily achieved by subsequently increasing the concentration of hydrocarbons, raising the reaction temperature, or extending the residence time. As described above, we believe that the basis of carbon fiber production is how to select carbon nucleus generation and its growth conditions, and have arrived at the present invention with the aim of increasing the generation density of elementary fibers. To generate carbon fiber by the vapor phase method using ultrafine metal seeding, as is already known, hydrocarbon vapor is diluted with carrier gas in a heat-resistant reaction tube heated to a predetermined temperature using an electric furnace or the like. Carbon fibers are produced on a heat-resistant base material in which ultrafine metal particles with an average particle size of 500 Å or less are dispersed by suspending them in a dispersion medium such as high-purity alcohol and spraying. Here, the reaction tube is usually made of alumina, quartz, etc., the heating temperature is 800 to 1300℃, and the hydrocarbons are benzene, toluene, methane, ethane, etc.
Saturated or unsaturated aliphatics such as propane, butane, ethylene, propylene, and cyclohexane, aromatics, or hydrocarbons having a fused polycyclic structure of two or more rings such as anthracene, phenanthrene, chrysene, fluoranthrene, and pyrene can be used. A mixture of these, volatile oil or kerosene can also be used. The carrier gas may be an inert gas that is non-oxidizing to carbon, such as hydrogen, nitrogen, or argon, or a small amount of an active gas that is oxidizing or reactive to carbon at 800°C, such as water vapor or carbon dioxide, is added. Graphite, quartz, or alumina are also known as heat-resistant substrates placed inside the reaction tube. Metals for carbon nucleation include Fe;
Elements of Group B of the periodic table such as Co and Ni, Group B such as V and Nb, or compounds thereof such as carbides and oxides are used. These ultrafine metal particles are
For example, it can be obtained by heating a metal in an atmosphere of helium or argon to evaporate it and condensing it into a medium (evaporation in gas method). The surface of these commercially available ultrafine metal powders is usually covered with a dense oxide film, and even if they are shaken and stirred in water or ethyl alcohol, most of them settle into aggregates and are extremely prone to agglomeration. It is. The mechanism for producing vapor-grown carbon fibers by the seeding method is that, for example, when ultrafine iron particle catalysts are used, minute iron particles generated by the reduction of iron oxide are present in the form of droplets on the surface of the substrate. A carbon species (polycyclic aromatic substance) is supplied, and this carbon species undergoes a condensation process while undergoing surface diffusion, changing into a carbon solid, and carbon is distributed vertically at the interface between the substrate and the droplet-like particle. It is believed that a layered surface is formed and the particles are eventually pushed up and fibers grow. This reaction process occurs only on the surface of the droplet, and the formation of hollow tubes has been confirmed by observation of the produced carbon fibers using a transmission electron microscope. The formation of fibers depends on the type of carbon species (such as C/H ratio) and Of course, the catalyst particle size is sensitively influenced by the ambient temperature and hydrocarbon partial pressure. Therefore, the metal catalyst particles
By effectively performing seeding and controlling the production conditions, it is possible to control the density, thickness, length, and homogeneity of fibers in an extremely simple process on an industrial scale. Effective seeding here means, for example, in the case of iron, when the particle size is 300 Å or less, the particles are suspended in a volatile dispersion medium such as alcohol, sprayed, etc., and dried. It can be dispersed in an upright manner on the substrate, and only a very small amount is required. When hydrogen is used as the carrier gas, the catalyst is cyclic and acts as a metal element. In the formation of carbon fibers after nucleation from seeding, growth occurs first in the length direction (fiber growth process), and then in the thickness direction (thickness growth process).
It is said that these occur separately (Japanese Unexamined Patent Publication No. 57-117622, page 140, bottom left column, Section 4). In the fiber growth process, the hydrocarbon vapor concentration and heating temperature can be lowered and the reaction tube cross-sectional average flow velocity can be made faster than in the thickness growth process, and the hydrogen concentration in the carrier gas or reaction time can also be set within a preferable range. There is a description of. However, although these conventional methods were followed, the production of fibers and the density thereof were insufficient. The present inventors investigated a method for producing fibers with good reproducibility and increasing their generation density, and found that it is greatly influenced by the dispersion state of ultrafine metal particles as a catalyst and their surface condition. It has been found that pre-milling the fine particles and heating them in an air atmosphere are very effective. Commercially available ultrafine iron powder (average particle size 100Å,
(manufactured by Shinku Yakini Co., Ltd.) was mixed to a concentration of 0.3% by weight and separately subjected to mashing and ultrasonic vibration stirring, but as will be described later, fiber formation experiments revealed that ultrasonic dispersion was insufficient. In order to dissociate agglomerates of ultrafine powders such as , 500 Å, it has been found that a grinding method such as a ball mill that directly crushes the fine particles itself is effective. In the examples of the present invention, a ball mill was used as the grinding device, but other devices suitable for the above purpose include tube mills, vibrating ball mills, and conical ball mills, which are commonly used for grinding ultrafine powders.
A crusher can also be used. However, even by seeding a suspension with good dispersion, the density of the fibers produced becomes sparse and only short fibers are obtained, which is insufficient. The cause is
Microscopic examination revealed that the ultrafine iron powder was sintered, and the resulting fibers became thicker from the early stages of growth.
Even if the catalyst particles are well dispersed during the preparation of the seeding liquid, sintering occurs during the temperature rise in the furnace, resulting in poor production. Furthermore, it is said that a dense oxide film of 3 to 4 atomic layers (Fe 3 O 4 in the case of ultrafine iron powder) is formed on the surface of the ultrafine metal catalyst during the manufacturing process, and this surface structure is due to the sintering of the particles. This is thought to have an effect on the results. The present inventors aimed at modifying the particle surface.
Ultrafine iron powder was oxidized at low temperature in an air atmosphere to form Fe 2 O 3 with a coarse crystal structure on the particle surface.
When the state was observed using an electron microscope immediately after the low-temperature oxidation and after the temperature was raised to the reaction temperature, it was found that the particles were well dispersed and sintering between the particles was suppressed. Furthermore, when a carbon fiber production experiment was conducted after low-temperature oxidation treatment, the density of the fibers generated further increased and the amount produced also increased. Although the above explanation refers to iron, the effect of low-temperature oxidation of ultrafine metal particles on well-known metals that can be used in the present invention is that the effect of low-temperature oxidation of ultrafine metal particles on the surface of the bulk layer of ultrafine metal particles dispersed on the substrate Rough metal oxide scale that does not adhere to metal on the surface of a certain particle,
Alternatively, it is considered that embrittlement of the metal occurs due to oxidation between crystal grains, giving a dispersed state of erect metal catalyst particles similar to the preferable single sphere model. Oxidation occurs at low-temperature oxidation temperatures of around 150℃.
As the temperature is increased to 400℃, 600℃, and 800℃, the sintering of catalyst particles progresses and the density of the catalyst particles decreases, but the optimal oxidation conditions that do not reduce the density of the particles are 300℃ to 600℃.
It is 30 minutes. The order of operations for grinding and dispersing ultrafine metal powder and low-temperature oxidation treatment is based on the results of Example 2 and Example 3 shown later.
It was found that oxidation treatment on the substrate after grinding and dispersion showed a more significant effect. When heated and oxidized before grinding,
Sintering of the aggregated ultrafine particles tends to occur, and it is thought that the subsequent grinding and dispersion cannot sufficiently disperse the particles. On the other hand, after being ground and dispersed on the substrate,
It is thought that when heated and oxidized, sintering of ultrafine particles among themselves is unlikely to occur. In addition to low-temperature oxidation treatment, the temperature inside the reaction tube is raised to a predetermined reaction temperature for the purpose of promoting the precipitation of graphite at metal grain boundaries, so-called carbon nucleation. 30
When the temperature was raised to ~100℃ in a short period of about 10 minutes and the temperature rose to the specified reaction temperature, it was immediately returned to the original reaction temperature in about 5 minutes.
We have discovered that this method has the effect of increasing the density of carbon fiber produced. As a result of many experiments, it was found that rapid heating is not effective at temperatures below 30°C, and even at temperatures higher than 100°C, the effect saturates and is uneconomical. EXAMPLES Hereinafter, the present invention will be explained in detail with reference to Examples, but the present invention is not limited thereto. Example 1 Heating section length 400 mm with temperature control shown in Figure 1
An alumina reaction tube 7 with a length of 1000 mm, an outer diameter of 50 mm, and an inner diameter of 42 mm is installed in an electric furnace 6, 8, 9, and 10 equipped with a silicon carbide-based (trade name: Siliconite) heating element of mm. thinner length 300
A device was used in which the catalyst was seeded onto a substrate 5 made by vertically splitting an alumina tube with an outer diameter of 37 mm and an inner diameter of 30 mm into the center of the reaction tube, with each half of the substrate aligned vertically. Then, the present invention was implemented. First, ultrafine iron powder with an average particle size of 100 Å (Shinku Yakini Co., Ltd.)
(manufactured by Mimaki Co., Ltd.) in 200 ml of high-purity ethyl alcohol at a concentration of 0.3% by weight.
Internally filled porcelain balls: 25 diameter 20mm balls and 25 diameter 15mm balls
(Total ball weight: 587 g) is rotated at 100 rpm.
By grinding for 24 hours, a catalyst dispersion liquid for spraying in which ultrafine iron particles were dispersed and suspended in ethyl alcohol was prepared. Spray 0.5 ml of this uniformly onto the inner wall of the substrate 5, which has been cut in half, and assemble the two half-split substrates, each sprayed with the catalyst dispersion liquid, into the reactor 7 vertically to form a tube. I loaded it. Subsequently, air was circulated from one end of the reaction tube to the other at a rate of 300 c.c./min, and the reaction tube was heated until the temperature within the tube reached 400° C., and maintained at that temperature for 30 minutes (thermal oxidation). Subsequently, the air was switched to nitrogen gas, and the temperature inside the reaction tube was raised to 900°C. Now switch the nitrogen gas to hydrogen gas and make it 70c.c./min.
The temperature inside the reaction tube was raised to 1000°C. Here, hydrogen gas was introduced into the reaction tube as a carrier gas to start the reaction while maintaining the benzene temperature in the raw benzene container 2 at 5.5°C by controlling the temperature in the constant temperature bath 3 so that the benzene vapor was 1.2% by volume. . Hydrogen gas was flowed at 19 c.c./min into the benzene container 2 and at 51 c.c./min through the bypass line so that the benzene concentration was 1.2% by volume before entering the reaction tube. After the start of the reaction, this temperature of 1000°C and benzene concentration of 1.2% by volume were maintained for 30 minutes (growth process of elementary fibers). Next, the flow of hydrogen to the biparas line is stopped, and the entire amount of hydrogen is allowed to flow through the benzene container, and the temperature inside the reaction tube is raised to 1100°C, and the benzene concentration is reduced to 7.5% by volume (benzene temperature inside the benzene container: 15°C). This state was maintained for 1 hour (fiber thickness growth process). Subsequently, the power to the electric furnace was shut off, and the mixed gas of hydrogen gas and benzene vapor was switched to nitrogen gas at room temperature to cool the substrate. With the above operations, the fiber length is approximately 50 mm, and the maximum length is approximately
0.46 g of carbon fiber with a fiber diameter of about 10 μm was obtained at 100 mm. The yield of carbon fibers based on the total amount of benzene supplied at this time was 28% on a weight basis. The total number of carbon fibers (occurrence density) concentrated in the longitudinal direction of the substrate per 5 mm of substrate circumference was 1304. The fiber generation density was measured throughout the present invention by the following method. The carbon fiber layer formed on the center inner wall of the lower part of the half-split substrate placed in the reaction tube is peeled off from the inner wall of the substrate with a cutter knife, and the carbon fiber layer that is peeled off is present in the radial cross section of the substrate circular tube. The number of carbon fibers is counted, and the measurement is carried out by cutting the carbon fiber layer to an appropriate size with sharp scissors, fixing it in a mold, and using a material such as epoxy that will not lose its transparency even after curing. The thermosetting resin is poured into a mold and allowed to solidify to form a specimen for microscopic examination. This sample was photographed using a microscope, and the final photograph was taken at a magnification of 125 times. The number of carbon fibers present in a cross section in the radial direction of the tube having a length of 5 mm in the circumferential direction of the substrate tube wall was counted on the photograph. Comparative Example 1 When ultrafine iron powder was simply ground in a dispersion medium in the same manner as in Example 1 without oxidation treatment, the fiber length of the obtained carbon fibers was the same as in Example 1, but the fiber diameter was The thickness was approximately 15 μm. The fiber density is
With 302 bottles, results with extremely poor production efficiency were obtained. Moreover, the yield was 7.5%. From this, it was found that the oxidation treatment of Example 1 had a remarkable effect. Example 2 During the operation of Example 1, the following rapid temperature increase/decrease operation was added. In other words, the temperature inside the reaction tube is the reaction temperature.
The temperature was raised from 1000°C to 1040°C in about 10 minutes, and immediately after reaching that temperature, the temperature was lowered to the reaction temperature of 1000°C. It took about 5 minutes to cool down. In this example, in addition to the heating oxidation treatment after the grinding and dispersion of the metal catalyst in Example 1, a rapid heating and cooling operation was carried out at the start of the reaction, and then the growth of elementary fibers and their thickness were continued in the same manner as in Example 1. The fiber diameter and length of the obtained carbon fibers were the same as in Example 1, but the yield was 32%, the fiber density was 1482, and the fiber growth was rapid. It was found that it is effective to use temperature raising and cooling treatments together. Comparative Example 2 To prepare a catalyst dispersion for spraying onto a substrate, an ultrasonic cleaner (manufactured by Yamato Scientific Co., Ltd., model number B-32) was used instead of the grinding and dispersion using a ball mill as described in Example 1. Ultrasonic waves with a frequency of 45 KHz were radiated for 1 hour for vibration stirring, and other operations were performed in the same manner as in Example 2 to produce carbon fibers. The length of the obtained fibers was the same as in Example 2, but the fiber diameter was thicker at about 15 μm, and the fiber generation density was extremely low at 261 fibers. The yield is
It was 9.5%. Example 3 During the operation of Example 2, in order to compare the effect of carrying out the oxidation treatment of the ultrafine metal catalyst before the grinding treatment in high-purity ethyl alcohol, we first used the same average particle size as in Example 1. Approximately 1 g of commercially available ultrafine iron powder of 100 Å was placed in a magnetic ashtray (for ash measurement), and using the apparatus described in Example 1, air was flowed through the reaction tube at 300 c.c./min and held at 400°C for 30 minutes. to oxidize the iron catalyst. After the oxidation is completed, the magnetic ashtray is taken out of the furnace and cooled, and the oxidized iron catalyst is used to prepare a catalyst dispersion for spraying by grinding in the same manner as described in Example 1, and to apply the catalyst dispersion onto a substrate. Spray dispersion and raising the temperature inside the reaction tube under a nitrogen gas atmosphere and a hydrogen gas atmosphere were performed. Subsequently, a reaction was started with benzene vapor using a hydrogen gas carrier, and thereafter, the same rapid heating and cooling processes as described in Example 2 and the operations of growing the length and thickness of the elementary fibers were performed. The carbon fibers obtained in this way had the same fiber diameter and fiber length as in Example 1 or Example 2, but the yield was 16% and the fiber density was 735, which was the same as in Example 2. Although the generation of fibers was smaller than in the oxidation treatment performed on the substrate after grinding ultrafine iron powder, it was larger than in the comparative example. From the results of the above Examples and Comparative Examples collectively shown in Table 1, it is clear that the method of the present invention is superior. 【table】
第１図は、本発明の気相成長炭素繊維を製造し
た実験装置の概略を示す図である。
１……各流量計、２……ベンゼン容器、３……
恒温槽、４……観察窓、５……基板、６……電気
炉、７……反応管、８……熱電対、９……各温度
調節器、１０……温度記録計、１１……空気また
は窒素導入口、１２……水素導入口、１３……各
ガス排出口。
FIG. 1 is a diagram schematically showing an experimental apparatus for manufacturing the vapor-grown carbon fiber of the present invention. 1... Each flow meter, 2... Benzene container, 3...
Constant temperature bath, 4...Observation window, 5...Substrate, 6...Electric furnace, 7...Reaction tube, 8...Thermocouple, 9...Each temperature controller, 10...Temperature recorder, 11... Air or nitrogen inlet, 12...hydrogen inlet, 13...each gas outlet.
Claims (1)
化水素蒸気を水素とともに反応管に導入するに先
立ち、金属超微粉触媒を液体分散媒とともに摩砕
して耐熱基板上に分散させ該基板を反応管内で空
気雰囲気下に加熱酸化するか、又は該金属超微粉
触媒を直接空気雰囲気下に加熱酸化した後に液体
分散媒とともに摩砕して該基板上に分散させるか
の少なくとも金属超微粉触媒の摩砕分散と加熱酸
化処理をすることを特徴とする繊維発生密度の高
い気相法炭素繊維の製造方法。 ２ 金属超微粉触媒の摩砕分散と加熱酸化処理に
加えて、炭化水素蒸気を800〜1300℃の範囲の反
応温度に保たれた反応管内に導入すると同時に反
応管内温度を該反応温度から30℃以上、10分程度
の短時間で急速に昇温し、昇温後直ちに元の反応
温度まで５分程度で降下させることを特徴とする
特許請求の範囲第１項に記載の製造方法。 ３ 金属超微粉触媒の摩砕分散と加熱酸化処理
が、摩砕分散後耐熱基板上で加熱酸化処理するこ
とを特徴とする特許請求の範囲第１項または第２
項記載の製造方法。 ４ 耐熱基板上に分散させる平均粒径300Å以下
の金属超微粉触媒懸濁液を該金属触媒が１重量％
以下、好ましくは0.1〜0.3重量％になるように高
純度低級アルコールと混合し、ボールミルなどに
より摩砕して調製することを特徴とする特許請求
の範囲第１項乃至第３項のいずれかに記載の製造
方法。 ５ 金属超微粉の加熱酸化を150℃以上、好まし
くは300〜600℃で30分間空気雰囲気下で実施する
ことを特徴とする特許請求の範囲第１項乃至第３
項のいずれかに記載の製造方法。 ６ 800〜1300℃の反応温度からの温度上昇を10
分程度の短時間で100℃以下の範囲で行なうこと
を特徴とする特許請求の範囲第２項に記載の製造
方法。[Claims] 1. In a carbon fiber manufacturing method using a gas phase method, before introducing hydrocarbon vapor into a reaction tube together with hydrogen, ultrafine metal catalyst is ground together with a liquid dispersion medium and dispersed on a heat-resistant substrate. The substrate is heated and oxidized in an air atmosphere in a reaction tube, or the ultrafine metal catalyst is directly heated and oxidized in an air atmosphere, and then ground with a liquid dispersion medium to disperse at least the metal. A method for producing vapor-grown carbon fiber with a high fiber density, characterized by grinding and dispersing an ultrafine catalyst and heating and oxidizing it. 2. In addition to the grinding and dispersion of the ultrafine metal catalyst and the heating and oxidation treatment, hydrocarbon vapor is introduced into the reaction tube maintained at a reaction temperature in the range of 800 to 1300°C, and at the same time the temperature inside the reaction tube is lowered by 30°C from the reaction temperature. The manufacturing method according to claim 1, wherein the temperature is rapidly raised in a short period of about 10 minutes, and immediately after the temperature is raised, it is lowered to the original reaction temperature in about 5 minutes. 3. Claims 1 or 2, characterized in that the grinding and dispersion of the ultrafine metal catalyst and the heating oxidation treatment are performed on a heat resistant substrate after grinding and dispersion.
Manufacturing method described in section. 4 A suspension of ultrafine metal catalyst with an average particle size of 300 Å or less to be dispersed on a heat-resistant substrate is prepared by adding 1% by weight of the metal catalyst.
Hereinafter, according to any one of claims 1 to 3, the product is prepared by mixing with a high-purity lower alcohol so as to preferably have a concentration of 0.1 to 0.3% by weight, and grinding with a ball mill or the like. Manufacturing method described. 5. Claims 1 to 3, characterized in that the heating oxidation of ultrafine metal powder is carried out at 150°C or higher, preferably 300 to 600°C, for 30 minutes in an air atmosphere.
The manufacturing method described in any of paragraphs. 6 Temperature rise from 800 to 1300℃ to 10
2. The manufacturing method according to claim 2, wherein the manufacturing method is carried out at a temperature of 100° C. or less in a short time of about minutes.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17020782A JPS5959921A (en) | 1982-09-29 | 1982-09-29 | Manufacture of carbon fiber in vapor phase |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP17020782A JPS5959921A (en) | 1982-09-29 | 1982-09-29 | Manufacture of carbon fiber in vapor phase |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5959921A JPS5959921A (en) | 1984-04-05 |
| JPS6247968B2 true JPS6247968B2 (en) | 1987-10-12 |
Family
ID=15900646
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP17020782A Granted JPS5959921A (en) | 1982-09-29 | 1982-09-29 | Manufacture of carbon fiber in vapor phase |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5959921A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0690215B2 (en) * | 1989-12-08 | 1994-11-14 | 株式会社東芝 | Dispensing nozzle |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2564110B1 (en) * | 1984-05-10 | 1986-09-05 | Lorraine Carbone | PROCESS FOR PRODUCING VAPO-DEPOSITED CARBON FIBERS FROM METHANE |
| US4663230A (en) * | 1984-12-06 | 1987-05-05 | Hyperion Catalysis International, Inc. | Carbon fibrils, method for producing same and compositions containing same |
| US4855091A (en) * | 1985-04-15 | 1989-08-08 | The Dow Chemical Company | Method for the preparation of carbon filaments |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52103528A (en) * | 1976-02-25 | 1977-08-30 | Showa Denko Kk | Manufacture of carbon fibers by gas phase reaction |
| JPS55162412A (en) * | 1979-06-04 | 1980-12-17 | Asahi Chem Ind Co Ltd | Manufacture of carbonaceous whisker |
| JPS57117622A (en) * | 1981-01-14 | 1982-07-22 | Showa Denko Kk | Production of carbon fiber through vapor-phase process |
-
1982
- 1982-09-29 JP JP17020782A patent/JPS5959921A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS52103528A (en) * | 1976-02-25 | 1977-08-30 | Showa Denko Kk | Manufacture of carbon fibers by gas phase reaction |
| JPS55162412A (en) * | 1979-06-04 | 1980-12-17 | Asahi Chem Ind Co Ltd | Manufacture of carbonaceous whisker |
| JPS57117622A (en) * | 1981-01-14 | 1982-07-22 | Showa Denko Kk | Production of carbon fiber through vapor-phase process |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0690215B2 (en) * | 1989-12-08 | 1994-11-14 | 株式会社東芝 | Dispensing nozzle |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5959921A (en) | 1984-04-05 |
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