JPS6249364B2 - - Google Patents
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- JPS6249364B2 JPS6249364B2 JP58211050A JP21105083A JPS6249364B2 JP S6249364 B2 JPS6249364 B2 JP S6249364B2 JP 58211050 A JP58211050 A JP 58211050A JP 21105083 A JP21105083 A JP 21105083A JP S6249364 B2 JPS6249364 B2 JP S6249364B2
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- 239000007789 gas Substances 0.000 claims description 55
- 239000000463 material Substances 0.000 claims description 36
- 239000000835 fiber Substances 0.000 claims description 35
- 239000003054 catalyst Substances 0.000 claims description 31
- 229930195733 hydrocarbon Natural products 0.000 claims description 27
- 150000002430 hydrocarbons Chemical class 0.000 claims description 27
- 239000004215 Carbon black (E152) Substances 0.000 claims description 25
- 239000002245 particle Substances 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 17
- 230000006911 nucleation Effects 0.000 claims description 16
- 238000010899 nucleation Methods 0.000 claims description 16
- 239000000758 substrate Substances 0.000 claims description 16
- 229920000049 Carbon (fiber) Polymers 0.000 claims description 14
- 239000004917 carbon fiber Substances 0.000 claims description 14
- 238000004519 manufacturing process Methods 0.000 claims description 10
- 239000012159 carrier gas Substances 0.000 claims description 7
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 3
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 150000001875 compounds Chemical class 0.000 claims description 3
- 239000002612 dispersion medium Substances 0.000 claims description 3
- 230000005294 ferromagnetic effect Effects 0.000 claims description 3
- 229910052751 metal Inorganic materials 0.000 claims description 3
- 239000002184 metal Substances 0.000 claims description 3
- 239000003960 organic solvent Substances 0.000 claims description 3
- 238000001947 vapour-phase growth Methods 0.000 claims description 2
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 30
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 11
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 8
- 239000002134 carbon nanofiber Substances 0.000 description 8
- 229910052799 carbon Inorganic materials 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 6
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 6
- 239000006185 dispersion Substances 0.000 description 5
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 5
- 239000001257 hydrogen Substances 0.000 description 4
- 229910052739 hydrogen Inorganic materials 0.000 description 4
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 229910052786 argon Inorganic materials 0.000 description 3
- 238000007796 conventional method Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 2
- NHTMVDHEPJAVLT-UHFFFAOYSA-N Isooctane Chemical compound CC(C)CC(C)(C)C NHTMVDHEPJAVLT-UHFFFAOYSA-N 0.000 description 2
- UFWIBTONFRDIAS-UHFFFAOYSA-N Naphthalene Chemical compound C1=CC=CC2=CC=CC=C21 UFWIBTONFRDIAS-UHFFFAOYSA-N 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 238000011437 continuous method Methods 0.000 description 2
- JVSWJIKNEAIKJW-UHFFFAOYSA-N dimethyl-hexane Natural products CCCCCC(C)C JVSWJIKNEAIKJW-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- YNPNZTXNASCQKK-UHFFFAOYSA-N phenanthrene Chemical compound C1=CC=C2C3=CC=CC=C3C=CC2=C1 YNPNZTXNASCQKK-UHFFFAOYSA-N 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 239000011882 ultra-fine particle Substances 0.000 description 2
- -1 unsaturated fatty acid ions Chemical class 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- HSFWRNGVRCDJHI-UHFFFAOYSA-N alpha-acetylene Natural products C#C HSFWRNGVRCDJHI-UHFFFAOYSA-N 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 125000002534 ethynyl group Chemical group [H]C#C* 0.000 description 1
- 229910002804 graphite Inorganic materials 0.000 description 1
- 239000010439 graphite Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 125000005575 polycyclic aromatic hydrocarbon group Chemical group 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- 235000021122 unsaturated fatty acids Nutrition 0.000 description 1
- 238000009423 ventilation Methods 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Description
本発明は気相成長式炭素繊維の製造方法に関す
る。さらに詳しくは炭化水素ガスをキヤリヤガス
と共に電気炉内に導入し、熱分解することにより
炉内に設置した基材上で炭素繊維を製造する方法
に関するものである。
炭化水素を熱分解し、炭素繊維を得る方法は特
開昭48−41039号公報、特公昭51−33210号公報な
どに記載されている。
特開昭48−41039号公報の方法は高弾性率を有
する炭素繊維を得る為に、混合ガスの流速を10〜
30cm／分とし、核生成を1050〜1100℃の低い炉温
で行なわせるものであるが、核生成に長時間を要
し、生成する炭素繊維の発生密度〔基材単位面積
あたりの発生本数）が低く且つ繊維径のバラツキ
が大きい欠点を有する。
特開昭51−33210号公報に開示される方法は核
生成と繊維成長の混合ガス流速を分けて、始めに
100〜1500cm／分の流速で10〜90秒間送入して核
生成を行なわせ、次いで同流速を10〜30cm／分と
して繊維を成長させているが、繊維の発生密度が
充分なものではなく、且つ繊維径のバラツキも満
足されるものではない。
本発明者等は、触媒の分散混合ガスの流速、炭
化水素ガスの濃度及び基材温度について種々検討
した結果本発明に到達した。
即ち、本発明は、触媒が粒径200Å以下の強磁
性金属元素又はその化合物若しくはそれらを含む
合金であり、該触媒の分散媒が非極性有機溶媒で
ある触媒を実質的に独立粒子状態に散布した基材
を電気炉内に設置し、初めにキヤリヤガス中に
0.1〜４容量％の炭化水素ガスを含む混合ガスを
基材温度が1050〜1150℃に保持された炉芯管内に
１〜10cm／分の流速で導入し、30〜90分間繊維の
核生成及び長さ成長を行なわせた後、基材温度を
上昇させつつ混合ガス流速を５〜50cm／分の範囲
内で繊維径の増加と共に混合ガス流速を上げつつ
炭化水素の単位時間当たりの供給量を増加させな
がら繊維の太さ成長を行なわせることを特徴とす
る気相成長式炭素繊維の製造方法であり、従来法
に比べ繊維の発生密度が高く、且つ長さ成長を効
率よく行なわせ、径のバラツキの小さい気相成長
炭素繊維を短時間に大量に製造できる本発明に到
達したものである。
本発明でいう気相成長式炭素繊維とは炭化水素
ガスを熱分解して得られる炭素繊維を意味し、そ
の用語の意味は例えば工業材料第30巻第７号
（1982年）に示されている。
気相成長式炭素繊維の製造方法を第１図を用い
て説明する。発熱体を備えた電気炉９に炉芯管１
を設置し、炉芯管内中央部に触媒散布基材６を装
入し、炉芯管の一端から三方コツク３を用いてキ
ヤリヤガスのみを導入しつつ所定炉温まで昇温す
る。次に三方コツク３を用いてキヤリヤガスを恒
温槽１中のバブラー５に入れ所定濃度の混合ガス
を炉内に導入することにより基材に炭素繊維を生
成させる。
本発明の方法によれば、初めに混合ガス中の炭
化水素ガス濃度を0.1〜４容量％という従来法に
比べ低濃度にすることにより繊維の核が高発生密
度で生成する。特に炭化水素ガス通気初期は上記
範囲内で低濃度の方が好ましい。しかし0.1容量
％以下では供給炭化水素ガス量が少ない為に発生
密度が低くなると共にその後の成長速度が遅く、
好ましくない。４容量％以上では理由が明らかで
はないが炭化水素ガス濃度が高すぎて触媒上への
炭素吸着速度が炭素拡散・析出速度よりも速い為
か基材上に多量の炭素フイルムが生成する。核生
成は炭化水素ガス分圧と共に混合ガスの流速も大
きな影響を及ぼし、本発明によれば１〜10cm／分
という低流速により繊維核が高密度で発生し、そ
の後の長さ成長も充分に行なわれる。従来は10〜
30cm／分あるいは100〜1500cm／分の流速で核生
成が行なわれているが流速が速い為に触媒上への
炭素吸着が不十分な為に発生密度が低くなるもの
と考えられる。従つて混合ガス流速10cm／分以上
では核生成、長さ成長共に不充分となり、そのま
ま炭化水素ガス供給を続けるならば炭素フイルム
が多量に生成する結果となる。混合ガス流速が１
cm／分以下では炭化水素ガスの単位時間当たりの
供給量が低い為に成長速度が遅く、炭化水素ガス
分圧で補足するならば前記したように炭素フイル
ムが生成し好ましくない。
さらに基材温度についても初期の核生成及び長
さ成長に大きな影響を及ぼすことが判り、本発明
によれば1050〜1150℃にすることにより核生成、
長さ成長共に満足される。特に1080〜1120℃の範
囲が両方のバランスがよい。1050℃以下では長さ
成長速度が遅いので長時間を必要とし、1150℃以
上では長さ成長速度は速いが発生密度が低く、炭
化水素ガス分圧を高くするのと同じ傾向を示す。
さらに基材に散布する触媒の種類、粒径、散布
量なども核生成・長さ成長に影響を及ぼす。触媒
としては粒径200Å以下の強磁性金属元素（例え
ばFe.Ni.Coなど）又はその化合物若しくはそれ
らを含む合金を使用する。該超微粒子触媒を長鎖
不飽和脂肪酸イオンの強い化学吸着性を利用して
各種溶媒に安定にコロイド分散できる。本発明に
おいて、分散媒として揮発性の非極性有機溶媒
（例えば、ペンタン、ヘキサンイソオクタンな
ど）を用いることを特徴としている。該触媒分散
液をスプレーにて基材に均一に散布し、該触媒粒
子を実質的に独立した一次粒子の状態で存在させ
ることができる。ただしこの場合触媒粒子の30％
以下が凝集していてもよい。従来、Feなどの遷
移金属超微粒子状触媒をエタノールなどの揮発性
溶媒に懸濁させたものを基材に散布して使用して
いるが、各粒子が数珠玉状に連結しており、各
個々の粒子に析出・成長する気相成長式炭素繊維
の発生密度向上を阻害しているものである。本発
明において、基材に散布した触媒粒子を実質的に
独立粒子状態に存在させることは必要不可欠であ
る。当然のことながら最適触媒散布量があり、最
適触媒散布量は基材単位面積あたり５〜500mg／
m2が好ましく、５mg／m2以下では触媒散布量が少
ない為に発生密度が低く、500mg／m2以上では触
媒粒子の重なりが多くなる為に発生密度が低くな
る。
このように最適条件にて触媒を散布した基材を
電気炉内に設置し、初めにキヤリヤガス中に0.1
〜４容量％の炭化水素ガスを含む混合ガスを基材
温度が1050〜1150℃に保持された炉芯管内に１〜
10cm／分の流速で導入し、30〜90分間繊維の核生
成及び長さ成長を行なわせるが、この場合太さ成
長が全然起らないのではなく長さ成長が主体にな
つていることを付記しておく。この段階で反応を
停止しても、高発生密度で長さの長い炭素繊維が
生成しているので充分各種用途に提供することが
可能である。しかしながら、さらに効率よく繊維
径を太くし繊維径のバラツキの小さい気相成長式
炭素繊維を短時間に製造できることは工業的に極
めて有用であり、本発明によれば長さ成長がほぼ
終了した後、基材温度を上昇させつつ混合ガス流
速を５〜50cm／分の範囲内で繊維径の増加と共に
混合ガス流速を上げつつ単位時間当たりの炭化水
素ガス供給量を増加させながら反応時間を選定す
ることにより任意の繊維径に調節することができ
る。従来法のように混合ガス流速が一定では基材
長さ方向の繊維径のバラツキが大きく、特に基材
後半部（炭化水素ガス排出側）の径の肥大化速度
が遅く反応時間を長くとればとるほど径のバラツ
キは大きくなる。本発明の方法によれば、繊維径
の増加と共に基材温度、混合ガス流速、炭化水素
ガス供給量を上げることにより、理由はよくわか
らないが基材全体に繊維径のバラツキの小さい炭
素繊維を生成させることができる。各々の上昇方
法は連続式でも段階式でもよいが、好ましくは連
続式の方が繊維径のバラツキは小さい。
基材温度の上昇速度は0.2〜２℃／分とするの
が好ましく、0.2℃／分以下では繊維径のバラツ
キが大きく、且つ太さ成長速度が低く、２℃／分
以上ではスス状炭素が繊維に付着しやすいので好
ましくない。
炭化水素ガス供給量は炭化水素ガス濃度一定で
も混合ガス流速上昇により増加するが、炭化水素
ガス濃度を高くすることにより単位時間当たりの
生成量を増加させることができる。
以上のような本発明の方法によれば、基材全体
に高発生密度で且つ繊維径のバラツキの小さい気
相成長式炭素繊維を短時間に大量に製造すること
が可能となり工業的に極めて有利である。
本発明で用いるキヤリヤガスは水素ガスを用い
るが、これにアルゴン、窒素ガス等の不活性ガス
を混合してもよい。
炭化水素はベンゼン、トルエン、キシレン等の
芳香族炭化水素類、メタン、エタン、プロパン、
エチレン、プロピレン、アセチレン等の脂肪族炭
化水素類、ナフタレン、フエナントレン等の多環
芳香族炭化水素類等を用いる。
炉芯管内に設置する繊維生成用基材はアルミナ
などのセラミツクス質あるいは黒鉛質のものを使
用する。
キヤリヤガスと炭化水素ガスを、内部に繊維生
成用基材を備えた炉芯管内に送入するが、その際
混合ガスの流速としては炉芯管入口断面における
常温換算値とする。
以下、触媒を実質的に独立粒子状態に散布した
基材を用いて核生成及び長さ成長を行なわせた例
を参考例に、又、本発明の態様を実施例によつて
説明する。
参考例 １
平均粒径100ÅのFe（真空治金株式会社製）を
ｎ−ヘキサン中に均一分散後、該分散液をスプレ
ーにてアルミナ質基材（外径58mm、内径50mm、長
さ150mmを長さ方向に２分割にしたもの）に50
mg／m2相当量のFeを散布した。
シリコニツト発熱体を備えた電気炉内に水平に
設置されたムライト質炉芯管（内径60mm、長さ
2000mm）内に上記の触媒散布基材を装入した。炉
芯管の一端にガス導入管、他端に排出管を接続
し、炉芯管内をアルゴンガスで置換後、水素ガス
を導入しつつ基材温度が1120℃になるまで昇温し
た。
昇温後、ベンゼン2.4容量％を含む水素ガスと
の混合スガを150c.c.／分（流速5.3cm／分）を60分
間通した。その後、ガスをアルゴンに切換えて冷
却し繊維生成基材を取り出した。生成した炭素繊
維を基材から採取し、繊維の径、長さ、生成量を
測定し、発生密度を算出した。その結果を第１表
に示す。
比較例 １
参考例１と同様の方法にて触媒を散布したアル
ミナ質基材を炉芯管内に装入し、水素ガスを導入
しつつ基材温度を1100℃まで昇温した。昇温後、
ベンゼン10容量％を含む水素との混合ガスを420
c.c.／分（流速14.9cm／分）を60分間流した。その
結果を第１表に示す。
比較例 ２
参考例１と同様の方法にて触媒を散布したアル
ミナ質基材を炉芯管内に装入し、水素ガスを導入
しつつ基材温度を1100℃まで昇温した。
昇温後、ベンゼン2.4容量％を含む水素との混
合ガスを14100c.c.／分（流速500cm／分）を40秒間
流した。その後、混合ガス流速を705c.c.／分（流
速25cm／分）として60分間流した。その結果を第
１表に示す。
比較例 ３
平均粒径100ÅのFe（真空治金株式会社製）を
エタノールに懸濁した触媒液を用いる以外は全て
参考例１と同様の方法にて実施した。その結果を
第１表に示す。
比較例 ４
触媒散布量を1000mg／m2とする以外は全て参考
例１と同様の方法にて実施した。その結果を第１
表に示す。
実施例 １
参考例１と同様の方法にて触媒を散布したアル
ミナ質基材を炉芯管内に装入し、水素ガスを導入
しつつ基材温度を1100℃まで昇温した。
昇温後、ベンゼン3.6容量％を含む水素との混
合ガスを100c.c.／分（流速3.5cm／分）を送入し、
45分間核生成及び長さ成長を行なわせた。その
後、135分かけて1235℃まで昇温しつつベンゼン
分圧を2.4容量％から10.5容量％まで徐々に上
げ、且つ混合ガスの流速を1180c.c.／分（流速42
cm／分）まで８c.c.／分の速度で上げていつた。
冷却後、生成した炭素繊維の径、長さ、生成量
を測定し、発生密度を算出した。その結果を第１
表に示す。
比較例 ５
基材温度を最初から最後まで1100℃一定とする
以外は全て実施例１と同様の方法にて実施した。
その結果を第１表に示す。
比較例 ６
混合ガス流量を最初から最後まで100c.c.／分と
する以外は全て実施例１と同様の方法にて実施し
た。その結果を第１表に示す。
比較例 ７
ベンゼン供給量を最初から最後まで12.5mg／分
（基材温度と混合ガス流量は実施例１のように上
げていくが、ベンゼン分圧は徐々に下げていく）
とする以外は全て実施例１と同様の方法にて実施
した。その結果を第１表に示す。
実施例 ２
平均粒径150ÅのFe−Ni（真空治金株式会社
製）をイソオクタン中に均一分散後、該分散液を
アルミナ質基材に100mg／m2相当量のFe−Niを散
布した。該基材を炉芯管内に装入し、水素ガスを
導入しつつ基材温度を1100℃まで昇温した。
昇温後、ベンゼン1.2容量％を含む水素との混
合ガスを150c.c.／分（流速5.3cm／分）を45分間送
入し、核生成及び長さ成長を行なわせた。その
後、基材温度を1130℃、1160℃、1190℃、混合ガ
ス流量を300c.c.／分、600c.c.／分、1200c.c.／分、ベ
ンゼン分圧を2.4容量％、4.8容量％、9.6容量％と
いう条件で各45分間階段式に上げていつた。その
結果を第１表に示す。
The present invention relates to a method for manufacturing vapor-grown carbon fiber. More specifically, the present invention relates to a method of manufacturing carbon fibers on a base material placed in the furnace by introducing hydrocarbon gas together with a carrier gas into an electric furnace and thermally decomposing the gas. Methods for obtaining carbon fibers by thermally decomposing hydrocarbons are described in Japanese Patent Application Laid-open No. 48-41039, Japanese Patent Publication No. 51-33210, and the like. The method disclosed in Japanese Patent Application Laid-open No. 48-41039 aims to increase the flow rate of the mixed gas from 10 to
The speed is 30cm/min, and nucleation is performed at a low furnace temperature of 1050 to 1100℃, but nucleation takes a long time and the density of the carbon fibers produced [number of fibers generated per unit area of base material] It has the disadvantages of low fiber diameter and large variation in fiber diameter. The method disclosed in JP-A-51-33210 separates the mixed gas flow rate for nucleation and fiber growth, and
The fibers are fed at a flow rate of 100 to 1500 cm/min for 10 to 90 seconds to cause nucleation, and then the same flow rate is changed to 10 to 30 cm/min to grow fibers, but the density of the fibers generated is not sufficient. , and the variation in fiber diameter is also unsatisfactory. The present inventors have arrived at the present invention as a result of various studies regarding the flow rate of the catalyst dispersed mixed gas, the concentration of hydrocarbon gas, and the substrate temperature. That is, the present invention provides a method in which a catalyst is a ferromagnetic metal element, a compound thereof, or an alloy containing them with a particle size of 200 Å or less, and a catalyst in which the dispersion medium of the catalyst is a nonpolar organic solvent is dispersed in the state of substantially independent particles. The base material is placed in an electric furnace and first immersed in carrier gas.
A mixed gas containing 0.1 to 4% by volume of hydrocarbon gas is introduced into the furnace core tube whose substrate temperature is maintained at 1050 to 1150°C at a flow rate of 1 to 10 cm/min, and fiber nucleation and After the length growth, the mixed gas flow rate is increased within the range of 5 to 50 cm/min while increasing the substrate temperature, and the amount of hydrocarbon supplied per unit time is increased as the fiber diameter increases. This is a method for manufacturing carbon fiber using a vapor phase growth method, which is characterized by growing the fiber thickness while increasing the fiber thickness.Compared to conventional methods, the fiber generation density is higher, the length growth is performed more efficiently, and the diameter is increased. The present invention has been achieved which enables the production of large quantities of vapor-grown carbon fibers with small variations in carbon fibers in a short period of time. The term "vapor-grown carbon fiber" as used in the present invention refers to carbon fiber obtained by thermally decomposing hydrocarbon gas, and the meaning of the term is as shown in, for example, Kogyo Materials Vol. 30, No. 7 (1982). There is. A method for producing vapor-grown carbon fiber will be explained with reference to FIG. A furnace core tube 1 is installed in an electric furnace 9 equipped with a heating element.
A catalyst dispersion base material 6 is placed in the center of the furnace core tube, and the temperature is raised to a predetermined furnace temperature while introducing only the carrier gas from one end of the furnace core tube using the three-way pot 3. Next, a carrier gas is put into the bubbler 5 in the thermostatic chamber 1 using the three-way pot 3, and a mixed gas of a predetermined concentration is introduced into the furnace, thereby producing carbon fibers on the base material. According to the method of the present invention, fiber nuclei are generated at a high density by first lowering the hydrocarbon gas concentration in the mixed gas to 0.1 to 4% by volume, which is lower than in the conventional method. Particularly in the initial stage of hydrocarbon gas ventilation, a low concentration within the above range is preferable. However, if it is less than 0.1% by volume, the amount of hydrocarbon gas supplied is small, so the generation density is low and the subsequent growth rate is slow.
Undesirable. At 4% by volume or more, a large amount of carbon film is formed on the substrate, probably because the hydrocarbon gas concentration is too high and the rate of carbon adsorption onto the catalyst is faster than the rate of carbon diffusion and precipitation, although the reason is not clear. Nucleation is greatly influenced by the flow rate of the mixed gas as well as the partial pressure of the hydrocarbon gas, and according to the present invention, fiber nuclei are generated at a high density at a low flow rate of 1 to 10 cm/min, and the subsequent length growth is also sufficient. It is done. Previously 10~
Nucleation is performed at a flow rate of 30 cm/min or 100 to 1500 cm/min, but it is thought that due to the high flow rate, carbon adsorption onto the catalyst is insufficient, resulting in a low generation density. Therefore, if the mixed gas flow rate exceeds 10 cm/min, both nucleation and length growth will be insufficient, and if the hydrocarbon gas supply continues as it is, a large amount of carbon film will result. Mixed gas flow rate is 1
cm/min or less, the growth rate is slow because the amount of hydrocarbon gas supplied per unit time is low, and if supplemented by the hydrocarbon gas partial pressure, a carbon film will be produced as described above, which is undesirable. Furthermore, it has been found that the substrate temperature has a great effect on initial nucleation and length growth, and according to the present invention, by setting the temperature to 1050 to 1150°C, nucleation and
Satisfied with both length and growth. In particular, the range of 1080 to 1120°C has a good balance of both. At temperatures below 1050°C, the length growth rate is slow and a long time is required; at temperatures above 1150°C, the length growth rate is fast but the generation density is low, showing the same tendency as increasing the hydrocarbon gas partial pressure. Furthermore, the type, particle size, and amount of catalyst sprayed on the substrate also affect nucleation and length growth. As the catalyst, a ferromagnetic metal element (for example, Fe.Ni.Co) or a compound thereof or an alloy containing them with a particle size of 200 Å or less is used. The ultrafine particle catalyst can be stably colloidally dispersed in various solvents by utilizing the strong chemical adsorption of long-chain unsaturated fatty acid ions. The present invention is characterized in that a volatile nonpolar organic solvent (eg, pentane, hexane isooctane, etc.) is used as a dispersion medium. The catalyst dispersion liquid can be uniformly dispersed onto the substrate by spraying, so that the catalyst particles can exist in the state of substantially independent primary particles. However, in this case, 30% of the catalyst particles
The following may be aggregated. Conventionally, transition metal ultrafine particle catalysts such as Fe are suspended in volatile solvents such as ethanol and used by scattering them on a substrate, but each particle is connected in a bead-like manner, and each individual particle is suspended in a volatile solvent such as ethanol. This prevents the increase in the density of vapor-grown carbon fibers that precipitate and grow into particles. In the present invention, it is essential that the catalyst particles dispersed on the substrate exist in a substantially independent particle state. Naturally, there is an optimum amount of catalyst to be applied, and the optimum amount of catalyst to be applied is 5 to 500 mg per unit area of the base material.
m 2 is preferable; if it is less than 5 mg/m 2 , the amount of catalyst sprayed is small, resulting in a low generation density, and if it is 500 mg/m 2 or more, the catalyst particles overlap, resulting in a low generation density. The base material on which the catalyst was sprayed under optimal conditions was placed in an electric furnace, and 0.1
A mixed gas containing ~4% by volume of hydrocarbon gas is placed in a furnace core tube whose base material temperature is maintained at 1050~1150℃.
The fibers were introduced at a flow rate of 10 cm/min to allow nucleation and length growth of the fibers for 30 to 90 minutes, but in this case, it was not that no thickness growth occurred at all, but that the length growth was the main factor. I would like to add this. Even if the reaction is stopped at this stage, carbon fibers with a high generation density and a long length are produced, so that they can be sufficiently provided for various uses. However, it is extremely useful industrially to be able to increase the fiber diameter more efficiently and produce vapor-grown carbon fibers with less variation in fiber diameter in a short time. , the reaction time is selected while increasing the mixed gas flow rate within the range of 5 to 50 cm/min while increasing the base material temperature and increasing the hydrocarbon gas supply amount per unit time while increasing the mixed gas flow rate as the fiber diameter increases. By this, the fiber diameter can be adjusted to any desired value. If the mixed gas flow rate is constant as in the conventional method, there will be large variations in the fiber diameter in the longitudinal direction of the base material, especially if the diameter of the rear half of the base material (hydrocarbon gas discharge side) increases slowly and the reaction time is long. The larger the diameter, the greater the variation in diameter. According to the method of the present invention, by increasing the base material temperature, mixed gas flow rate, and hydrocarbon gas supply amount as well as increasing the fiber diameter, carbon fibers with small variations in fiber diameter over the entire base material are produced, although the reason is not clear. can be done. Although each raising method may be a continuous method or a stepwise method, it is preferable that the continuous method has a smaller variation in fiber diameter. The rate of increase in substrate temperature is preferably 0.2 to 2°C/min. Below 0.2°C/min, the fiber diameter will vary widely and the thickness growth rate will be low, and if it is over 2°C/min, soot-like carbon will increase. It is not preferred because it tends to adhere to fibers. The amount of hydrocarbon gas supplied increases as the mixed gas flow rate increases even if the hydrocarbon gas concentration is constant, but by increasing the hydrocarbon gas concentration, the amount of production per unit time can be increased. According to the method of the present invention as described above, it is possible to produce a large amount of vapor-grown carbon fiber in a short time with high generation density and small variation in fiber diameter over the entire base material, which is extremely advantageous industrially. It is. Although hydrogen gas is used as the carrier gas in the present invention, an inert gas such as argon or nitrogen gas may be mixed therein. Hydrocarbons include aromatic hydrocarbons such as benzene, toluene, and xylene, methane, ethane, propane,
Aliphatic hydrocarbons such as ethylene, propylene, and acetylene, and polycyclic aromatic hydrocarbons such as naphthalene and phenanthrene are used. The fiber-generating base material installed in the furnace core tube is made of ceramic such as alumina or graphite. A carrier gas and a hydrocarbon gas are fed into a furnace core tube that is provided with a fiber-producing base material therein, and the flow rate of the mixed gas is a normal temperature equivalent value at the cross section at the entrance of the furnace core tube. Hereinafter, embodiments of the present invention will be explained by referring to reference examples, in which nucleation and length growth are carried out using a substrate on which a catalyst is dispersed in substantially independent particle state, and embodiments of the present invention. Reference Example 1 After uniformly dispersing Fe (manufactured by Shinku Yakin Co., Ltd.) with an average particle size of 100 Å in n-hexane, the dispersion was sprayed onto an alumina base material (outer diameter 58 mm, inner diameter 50 mm, length 150 mm). (divided into two in the length direction) 50
Fe was sprayed in an amount equivalent to mg/m 2 . A mullite furnace tube (inner diameter 60 mm, length
2000 mm) was charged with the above catalyst dispersion base material. A gas inlet pipe was connected to one end of the furnace core tube, and a discharge pipe was connected to the other end, and after replacing the inside of the furnace core tube with argon gas, the temperature of the base material was raised to 1120°C while introducing hydrogen gas. After raising the temperature, a mixture of hydrogen gas containing 2.4% by volume of benzene was passed through the tube at 150 c.c./min (flow rate 5.3 cm/min) for 60 minutes. Thereafter, the gas was switched to argon to cool it down, and the fiber-forming base material was taken out. The generated carbon fibers were collected from the base material, the fiber diameter, length, and amount produced were measured, and the generation density was calculated. The results are shown in Table 1. Comparative Example 1 An alumina base material sprinkled with a catalyst in the same manner as in Reference Example 1 was charged into a furnace core tube, and the base material temperature was raised to 1100° C. while introducing hydrogen gas. After raising the temperature,
420% mixed gas with hydrogen containing 10% by volume of benzene
cc/min (flow rate 14.9 cm/min) for 60 minutes. The results are shown in Table 1. Comparative Example 2 An alumina base material sprinkled with a catalyst in the same manner as in Reference Example 1 was charged into a furnace core tube, and the base material temperature was raised to 1100° C. while introducing hydrogen gas. After raising the temperature, a mixed gas containing 2.4% by volume of benzene and hydrogen was flowed at 14100 c.c./min (flow rate 500 cm/min) for 40 seconds. Thereafter, the mixed gas was flowed for 60 minutes at a flow rate of 705 c.c./min (flow rate 25 cm/min). The results are shown in Table 1. Comparative Example 3 A test was carried out in the same manner as in Reference Example 1, except that a catalyst solution in which Fe (manufactured by Shinku Yakin Co., Ltd.) having an average particle size of 100 Å was suspended in ethanol was used. The results are shown in Table 1. Comparative Example 4 The same method as in Reference Example 1 was carried out except that the amount of catalyst sprayed was 1000 mg/m 2 . The result is the first
Shown in the table. Example 1 An alumina base material sprinkled with a catalyst in the same manner as in Reference Example 1 was charged into a furnace core tube, and the base material temperature was raised to 1100° C. while introducing hydrogen gas. After raising the temperature, a mixed gas with hydrogen containing 3.6% by volume of benzene was introduced at a rate of 100c.c./min (flow rate 3.5cm/min).
Nucleation and length growth were allowed to occur for 45 minutes. After that, while raising the temperature to 1235℃ over 135 minutes, the benzene partial pressure was gradually increased from 2.4% by volume to 10.5% by volume, and the flow rate of the mixed gas was increased to 1180c.c./min (flow rate 42% by volume).
cm/min) at a rate of 8 c.c./min. After cooling, the diameter, length, and amount of generated carbon fibers were measured, and the generated density was calculated. The result is the first
Shown in the table. Comparative Example 5 The same method as in Example 1 was carried out except that the substrate temperature was kept constant at 1100°C from beginning to end.
The results are shown in Table 1. Comparative Example 6 The same procedure as in Example 1 was carried out except that the mixed gas flow rate was 100 c.c./min from beginning to end. The results are shown in Table 1. Comparative Example 7 Benzene supply rate was 12.5 mg/min from beginning to end (substrate temperature and mixed gas flow rate were increased as in Example 1, but benzene partial pressure was gradually decreased)
Everything was carried out in the same manner as in Example 1 except for the following. The results are shown in Table 1. Example 2 After uniformly dispersing Fe-Ni (manufactured by Shinku Yakin Co., Ltd.) with an average particle size of 150 Å in isooctane, the dispersion liquid was sprinkled on an alumina base material in an amount equivalent to 100 mg/m 2 of Fe-Ni. The base material was placed in a furnace core tube, and the temperature of the base material was raised to 1100° C. while introducing hydrogen gas. After raising the temperature, a mixed gas containing 1.2% by volume of benzene and hydrogen was fed at 150 c.c./min (flow rate 5.3 cm/min) for 45 minutes to cause nucleation and length growth. After that, the base material temperature was set to 1130℃, 1160℃, and 1190℃, the mixed gas flow rate was set to 300c.c./min, 600c.c./min, and 1200c.c./min, and the benzene partial pressure was set to 2.4% by volume and 4.8% by volume. % and 9.6% by volume for 45 minutes each. The results are shown in Table 1.
【表】【table】
【表】
第１表に示す変動率とは（標準偏差／平均値）
×100である。繊維発生密度とは生成した炭素繊
維の基材単位面積当たりの発生本数である。[Table] What is the fluctuation rate shown in Table 1 (standard deviation/average value)?
×100. The fiber generation density is the number of carbon fibers generated per unit area of the base material.
第１図は本発明の気相成長式炭素繊維の製造方
法を示す説明用図である。
１……恒温槽、２……炭化水素、３……三方コ
ツク、４……炉芯管、５……バブラー、６……基
材、７……炭素繊維、８……シール用ゴム栓、９
……電気炉。
FIG. 1 is an explanatory diagram showing the method for manufacturing vapor-grown carbon fiber of the present invention. 1... Constant temperature bath, 2... Hydrocarbon, 3... Three-way pot, 4... Furnace core tube, 5... Bubbler, 6... Base material, 7... Carbon fiber, 8... Rubber stopper for sealing, 9
……Electric furnace.
Claims (1)
その化合物若しくはそれらを含む合金であり、該
触媒の分散媒が非極性有機溶媒である触媒を独立
粒子状態に散布した基材を電気炉内に設置し、初
めにキヤリヤガス中に0.1〜４容量％の炭化水素
ガスを含む混合ガスを基材温度が1050〜1150℃に
保持された炉芯管内に１〜10cm／分の流速で導入
し、30〜90分間繊維の核生成及び長さ成長を行な
わせた後、基材温度を上昇させつつ混合ガス流速
を５〜50cm／分の範囲内で繊維径の増加と共に混
合ガス流速を上げつつ単位時間当たりの炭化水素
ガス供給量を増加させながら繊維の太さ成長を行
なわせることを特徴とする気相成長式炭素繊維の
製造方法。 ２ 基材に散布する触媒量が３〜500mg／m2であ
ることを特徴とする特許請求の範囲第１項記載の
製造方法。 ３ 基材温度を0.2〜２℃／分の速度で上昇させ
ることを特徴とする特許請求の範囲第１項記載の
製造方法。[Scope of Claims] 1. A group in which a catalyst is dispersed in the state of independent particles, in which the catalyst is a ferromagnetic metal element with a particle size of 200 Å or less, a compound thereof, or an alloy containing them, and the dispersion medium of the catalyst is a nonpolar organic solvent. The material is placed in an electric furnace, and a mixed gas containing 0.1 to 4% by volume of hydrocarbon gas in the carrier gas is heated at a rate of 1 to 10 cm/min into the furnace core tube whose base material temperature is maintained at 1050 to 1150°C. After introducing fibers at a flow rate to allow fiber nucleation and length growth for 30 to 90 minutes, the mixed gas flow rate was increased within the range of 5 to 50 cm/min while increasing the substrate temperature as the fiber diameter increased. A method for manufacturing carbon fiber by vapor phase growth, characterized by growing the thickness of the fiber while increasing the flow rate and the amount of hydrocarbon gas supplied per unit time. 2. The manufacturing method according to claim 1, wherein the amount of catalyst sprayed onto the substrate is 3 to 500 mg/ m2 . 3. The manufacturing method according to claim 1, wherein the substrate temperature is increased at a rate of 0.2 to 2° C./min.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21105083A JPS60104526A (en) | 1983-11-11 | 1983-11-11 | Preparation of carbon fiber by gaseous-phase growth method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP21105083A JPS60104526A (en) | 1983-11-11 | 1983-11-11 | Preparation of carbon fiber by gaseous-phase growth method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60104526A JPS60104526A (en) | 1985-06-08 |
| JPS6249364B2 true JPS6249364B2 (en) | 1987-10-19 |
Family
ID=16599549
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP21105083A Granted JPS60104526A (en) | 1983-11-11 | 1983-11-11 | Preparation of carbon fiber by gaseous-phase growth method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60104526A (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4663230A (en) * | 1984-12-06 | 1987-05-05 | Hyperion Catalysis International, Inc. | Carbon fibrils, method for producing same and compositions containing same |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5064527A (en) * | 1973-10-18 | 1975-05-31 | ||
| JPS57117622A (en) * | 1981-01-14 | 1982-07-22 | Showa Denko Kk | Production of carbon fiber through vapor-phase process |
-
1983
- 1983-11-11 JP JP21105083A patent/JPS60104526A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5064527A (en) * | 1973-10-18 | 1975-05-31 | ||
| JPS57117622A (en) * | 1981-01-14 | 1982-07-22 | Showa Denko Kk | Production of carbon fiber through vapor-phase process |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60104526A (en) | 1985-06-08 |
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