JPS63159299A - Production of silicon carbide whisker - Google Patents
Production of silicon carbide whiskerInfo
- Publication number
- JPS63159299A JPS63159299A JP61305123A JP30512386A JPS63159299A JP S63159299 A JPS63159299 A JP S63159299A JP 61305123 A JP61305123 A JP 61305123A JP 30512386 A JP30512386 A JP 30512386A JP S63159299 A JPS63159299 A JP S63159299A
- Authority
- JP
- Japan
- Prior art keywords
- silicon carbide
- carbide whiskers
- raw material
- carbon
- reaction
- 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
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 title claims description 49
- 238000004519 manufacturing process Methods 0.000 title claims description 17
- 229910010271 silicon carbide Inorganic materials 0.000 title description 9
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims abstract description 49
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000002994 raw material Substances 0.000 claims abstract description 26
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 25
- 239000000377 silicon dioxide Substances 0.000 claims abstract description 24
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 23
- 235000012239 silicon dioxide Nutrition 0.000 claims abstract description 21
- 239000001257 hydrogen Substances 0.000 claims abstract description 19
- 229910052739 hydrogen Inorganic materials 0.000 claims abstract description 19
- 239000007787 solid Substances 0.000 claims abstract description 15
- 238000010438 heat treatment Methods 0.000 claims abstract description 11
- 239000003054 catalyst Substances 0.000 claims abstract description 6
- 238000006243 chemical reaction Methods 0.000 claims description 32
- 239000000843 powder Substances 0.000 claims description 8
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical group [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 4
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 4
- 150000001875 compounds Chemical class 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 2
- 229910017052 cobalt Inorganic materials 0.000 claims description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 2
- 229910052742 iron Inorganic materials 0.000 claims description 2
- 229910052759 nickel Inorganic materials 0.000 claims description 2
- 229910052681 coesite Inorganic materials 0.000 abstract 3
- 229910052906 cristobalite Inorganic materials 0.000 abstract 3
- 229910052682 stishovite Inorganic materials 0.000 abstract 3
- 229910052905 tridymite Inorganic materials 0.000 abstract 3
- 238000000034 method Methods 0.000 description 21
- 239000007789 gas Substances 0.000 description 19
- 239000006229 carbon black Substances 0.000 description 7
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 7
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 6
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 6
- 229910052786 argon Inorganic materials 0.000 description 3
- 239000012071 phase Substances 0.000 description 3
- 238000010532 solid phase synthesis reaction Methods 0.000 description 3
- 238000001308 synthesis method Methods 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 238000005452 bending Methods 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 239000007809 chemical reaction catalyst Substances 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 2
- 230000035484 reaction time Effects 0.000 description 2
- 229910052814 silicon oxide Inorganic materials 0.000 description 2
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 239000002131 composite material Substances 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
- 238000001125 extrusion Methods 0.000 description 1
- 238000002309 gasification Methods 0.000 description 1
- 238000005469 granulation Methods 0.000 description 1
- 230000003179 granulation Effects 0.000 description 1
- 229910052736 halogen Inorganic materials 0.000 description 1
- 150000002367 halogens Chemical class 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 150000003961 organosilicon compounds Chemical class 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- NDLPOXTZKUMGOV-UHFFFAOYSA-N oxo(oxoferriooxy)iron hydrate Chemical compound O.O=[Fe]O[Fe]=O NDLPOXTZKUMGOV-UHFFFAOYSA-N 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000001376 precipitating effect Effects 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- -1 silicon halides Chemical class 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B25/00—Single-crystal growth by chemical reaction of reactive gases, e.g. chemical vapour-deposition growth
- C30B25/005—Growth of whiskers or needles
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B29/00—Single crystals or homogeneous polycrystalline material with defined structure characterised by the material or by their shape
- C30B29/10—Inorganic compounds or compositions
- C30B29/36—Carbides
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、炭化ケイ素ウィスカーの製造方法に関し、詳
しくは、高純度であって、且つ、直線性にすぐれる針状
単結晶炭化ケイ素ウィスカーを高収率にて製造する方法
に関する。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method for producing silicon carbide whiskers, and more specifically, to a method for producing acicular single crystal silicon carbide whiskers with high purity and excellent linearity. Relating to a method of manufacturing at a high rate.
従来の技術
炭化ケイ素ウィスカーは、軽量、高強度、高弾性を有し
、返本、複合材料の強化材として、種々の用途が期待さ
れている。BACKGROUND OF THE INVENTION Silicon carbide whiskers are lightweight, have high strength, and have high elasticity, and are expected to have various uses such as book return and reinforcing materials for composite materials.
このような炭化ケイ素ウィスカーの製造方法としては、
従来より、気相合成法と固相合成法とが代表的に知られ
ている。気相合成法としては、ハロゲン化ケイ素と炭化
水素との混合ガス、又は炭素及びハロゲンを含む有機ケ
イ素化合物ガスを水素気流中で熱分解する方法や、ケイ
素化合物を仕込んだ反応炉内に炭化水素や塩化水素等の
ガスを流通させることによって反応炉内に炭化ケイ素ウ
ィスカーを生成させる方法（特公昭５２−２８７５７号
公等外、二酸化ケイ素、炭素粉末、フッ化ナトリウム等
を充填したるつぼを不活性雰囲気中で加熱し、気化した
一酸化ケイ素や一酸化炭素を低温域で反応させて、炭化
ケイ素ウィスカーを析出成長させる方法（特公昭５４−
１５５５５号公報、特開昭５６−１００１２５号公報）
等が知られている。しかし、これらの方法はいずれも、
バッチ方式によらざるを得す、炭化ケイ素ウィスカーを
連続方式にて得ることができないので、炭化ケイ素ウィ
スカーを量産するには不適当である。The method for manufacturing such silicon carbide whiskers is as follows:
Conventionally, gas phase synthesis method and solid phase synthesis method are typically known. Gas phase synthesis methods include thermally decomposing a mixed gas of silicon halides and hydrocarbons, or organosilicon compound gas containing carbon and halogen, in a hydrogen stream; A method of producing silicon carbide whiskers in a reactor by circulating a gas such as carbon dioxide, hydrogen chloride, etc. (Japanese Patent Publication No. 52-28757, etc.) A method of precipitating and growing silicon carbide whiskers by heating in an atmosphere and reacting vaporized silicon monoxide and carbon monoxide in a low temperature range (Special Publication No. 1973-
15555, JP-A-56-100125)
etc. are known. However, all of these methods
Since silicon carbide whiskers cannot be obtained continuously by a batch method, it is not suitable for mass production of silicon carbide whiskers.
一方、固相合成法としては、粉末状ケイ素含有原料と粉
末状炭素含有原料とを均一に混合し、これをアチソン型
加熱炉において加熱して、炭化ケイ素ウィスカーを生成
させる方法（特開昭５８−１４５７００号公報）粉末状
ケイ素含有原料と炭素含有原料を混合して、成形し、こ
の成形体を匣鉢に入れてトレープッシャ一式加熱炉にて
加熱する方法（特開昭５８−２０７９９号公報、特開昭
５８−９１０１０号公報、特公昭ａｏ−２５９０７号公
１１）等が等外れている。このような同相合成法のうち
、前者の方法は、バッチ方式であるために量産には適さ
ない、従って、現在、工業的規模での炭化ケイ素ウィス
カーの製造には、殆どの場合、後者による連続製造方法
が採用されている。On the other hand, as a solid phase synthesis method, a powdered silicon-containing raw material and a powdered carbon-containing raw material are uniformly mixed and heated in an Acheson-type heating furnace to produce silicon carbide whiskers (Japanese Patent Laid-Open No. 58 -145700 Publication) A method in which a powdered silicon-containing raw material and a carbon-containing raw material are mixed and molded, and the molded body is placed in a sagger and heated in a heating furnace equipped with a tray pusher (Japanese Unexamined Patent Publication No. 58-20799) , Japanese Patent Application Laid-Open No. 58-91010, Japanese Patent Publication No. Sho-Ao-25907 (11), etc. are out of the range. Among these in-phase synthesis methods, the former method is not suitable for mass production because it is a batch method. Therefore, currently, in most cases, the latter method is used continuously for producing silicon carbide whiskers on an industrial scale. manufacturing method is used.
しかし、−Ｃに、固相合成法によるときは、粉状乃至屈
曲状の炭化ケイ素を多く生成し、直線性にすぐれる炭化
ケイ素ウィスカーを得ることが困難であるほか、得られ
た炭化ケイ素ウィスカーから上記のような粉状乃至屈曲
状の炭化ケイ素を分離除去することも容易ではない。However, when solid-phase synthesis is used for -C, a large amount of powdery or bent silicon carbide is produced, making it difficult to obtain silicon carbide whiskers with excellent linearity, and the resulting silicon carbide whiskers It is also not easy to separate and remove the powdery or bent silicon carbide as described above from the powder.
発明が解決しようとする問題点
本発明者らは、従来の炭化ケイ素ウィスカーの製造にお
ける上記した問題を解決するために鋭意研究した結果、
二酸化ケイ素を含むケイ素原料を予め成形し、これを限
られた反応空間内において炭素含有原料粉末と共に所定
量の水素を含む雰囲気下に所定の温度に加熱することに
よって、直線性にすぐれた針状単結晶炭化ケイ素ウィス
カーを高収率にて得ることができることを見出して本発
明に至ったものである。Problems to be Solved by the Invention As a result of intensive research by the present inventors to solve the above-mentioned problems in the production of conventional silicon carbide whiskers,
By pre-forming silicon raw material containing silicon dioxide and heating it to a predetermined temperature in an atmosphere containing a predetermined amount of hydrogen together with carbon-containing raw material powder in a limited reaction space, a needle shape with excellent linearity is formed. The present invention was achieved by discovering that single-crystal silicon carbide whiskers can be obtained in high yield.
間 点を解決するための 段
本発明は、限られた反応空間内で水素ガス及び触媒の存
在下に固体ケイ素含有原料と固体炭素含有原料とを加熱
して、炭化ケイ素ウィスカーを製造する方法において、
水素濃度７０％以上の雰囲気下で二酸化ケイ素を含有す
る成形体と炭素含有原料粉末とを１３００〜１７００℃
の温度に加熱することを特徴とする。The present invention provides a method for producing silicon carbide whiskers by heating a solid silicon-containing raw material and a solid carbon-containing raw material in the presence of hydrogen gas and a catalyst in a limited reaction space. ,
The molded body containing silicon dioxide and the carbon-containing raw material powder are heated at 1300 to 1700°C in an atmosphere with a hydrogen concentration of 70% or more.
It is characterized by being heated to a temperature of
本発明の方法において、二酸化ケイ素を含有する成形体
とは、例えば、ケイ石粉、粉状シリカゲル、各種の非晶
質シリカ、沈降性シリカ、粘土等の二酸化ケイ素を含む
原料を適宜の手段、例えば、押出成形、プレス成形、造
粒等の手段によって成形し、板、棒、管、粒乃至球、容
器や箱、線状又はこれらの組み合わせとしての形状を与
えた立体的な固体をいう。この成形体が例えば管状や箱
型の容器等のような成形体であるとき、固体炭素含有原
料を充填するための容器を兼ねさせることができる。In the method of the present invention, the silicon dioxide-containing molded body is defined as a silicon dioxide-containing raw material such as silica powder, powdered silica gel, various amorphous silicas, precipitated silica, clay, etc., by an appropriate means, e.g. A three-dimensional solid that is formed by extrusion molding, press molding, granulation, etc., and given the shape of a plate, rod, tube, particle or sphere, container or box, linear shape, or a combination thereof. When this molded body is a molded body such as a tubular or box-shaped container, it can also serve as a container for filling the solid carbon-containing raw material.
本発明において、上記二酸化ケイ素含有成形体は、高い
収率にて炭化ケイ素ウィスカーを得るためには、二酸化
ケイ素を３０重量％以上含有することが好ましく、特に
、４０重景％以上含有することが好ましい。In the present invention, in order to obtain silicon carbide whiskers at a high yield, the silicon dioxide-containing molded article preferably contains silicon dioxide in an amount of 30% by weight or more, particularly preferably 40% by weight or more. preferable.
また、固体炭素含有原料としては、カーボンブラックや
粉末活性炭、或いはタールやピッチの熱処理によって得
られる炭素等を用いることができる。Further, as the solid carbon-containing raw material, carbon black, powdered activated carbon, carbon obtained by heat treatment of tar or pitch, etc. can be used.
本発明の方法においては、上記二酸化ケイ素含有成形体
と固体炭素含有原料を水素ガス雰囲気下において、例え
ば、電気炉のような限られた空間内で所定温度に加熱し
て、炭化ケイ素ウィスカーを得るものであり、ここに、
水素ガス雰囲気として水素ガス濃度を常に７０％以上に
保持することによって、炭化ケイ素ウィスカーを著しく
高い収率にて得ることができる。尚、反応炉が、例えば
、二酸化ケイ素成形体と固体炭素含有原料とを加熱反応
させる反応帯域を含む複数の帯域からなる場合は、本発
明によれば、限られた空間とは、上記反応帯域をいい、
反応炉の少なくともこの帯域を雰囲気を水素濃度７０％
以上の雰囲気に保持すればよい。In the method of the present invention, the silicon dioxide-containing molded body and the solid carbon-containing raw material are heated to a predetermined temperature in a limited space such as an electric furnace in a hydrogen gas atmosphere to obtain silicon carbide whiskers. and here,
By always maintaining the hydrogen gas concentration at 70% or higher in the hydrogen gas atmosphere, silicon carbide whiskers can be obtained at a significantly high yield. In addition, when the reactor is composed of a plurality of zones including a reaction zone in which a silicon dioxide molded body and a solid carbon-containing raw material are heated and reacted, according to the present invention, the limited space is defined as the reaction zone say,
At least this zone of the reactor has an atmosphere with a hydrogen concentration of 70%.
It is sufficient to maintain the above atmosphere.
かかる本発明の方法においては、炭化ケイ素つイスカー
は、次のような反応によって生成するものとみられる。In the method of the present invention, silicon carbide iscar is thought to be produced by the following reaction.
但し、本発明は、反応機構によって何ら制限されるもの
ではない。However, the present invention is not limited in any way by the reaction mechanism.
Ｃ＋ ２８２→Ｃ）＋４
（１）Ｓｉ（ｈ＋ ＣＯ３−ＳｉＯ＋ Ｃｏ ＋ ２
Ｈｚ （２）ＳｉＯ＋ ２ＣＨａ→ ＳｉＣ
＋ ＣＯ＋ ４Ｈｚ （３１即ち、先ず、水
素ガスと固体炭素原料とが反応（１）によってメタンガ
スを生成し、これが二酸化ケイ素含有成形体の表面にお
いて、反応（２）によって−酸化ケイ素ガスが生成する
。次いで、この−酸化ケイ素ガスとメタンガスとの反応
（３）によって、炭化ケイ素が生成する。従って、総括
反応式は、５ｒＯｔ ＋ ３Ｃ→ＳｉＣ＋ ２ＣＯ（４
１で表わされることとなる。C+ 282→C)+4
(1) Si(h+ CO3-SiO+ Co + 2
Hz (2)SiO+ 2CHa→ SiC
+CO+ 4Hz (31 That is, first, hydrogen gas and solid carbon raw material generate methane gas by reaction (1), and -silicon oxide gas is generated by reaction (2) on the surface of the silicon dioxide-containing molded body. Next, silicon carbide is produced by the reaction (3) of this -silicon oxide gas and methane gas.Therefore, the overall reaction formula is 5rOt + 3C→SiC+ 2CO(4
It will be expressed as 1.
上記反応式（４）においては、水素は炭化ケイ素の生成
に関与していないが、水素は、反応（１）から（３）に
みられるように、反応過程に不可欠であり、更に、水素
ガスは、分子が小さいために、反応容器内を容易に拡散
して、二酸化ケイ素の一酸化ケイ素への還元及び炭素の
メタンガス化を容易ならしめるので、炭化ケイ素ウィス
カーの収量の増大に寄与し、しかも、本発明の方法にお
いては、最終的には反応（４）に示したように、炭化ケ
イ素ウィスカーは、気体反応によって生成するので、針
状性にすぐれるのであろう。In the above reaction formula (4), hydrogen does not participate in the production of silicon carbide, but hydrogen is essential to the reaction process as seen in reactions (1) to (3), and hydrogen gas Because of its small molecular size, it easily diffuses within the reaction vessel and facilitates the reduction of silicon dioxide to silicon monoxide and the gasification of carbon into methane, contributing to an increase in the yield of silicon carbide whiskers. In the method of the present invention, silicon carbide whiskers are ultimately produced by a gas reaction, as shown in reaction (4), so they probably have excellent needle-like properties.
以上のように、上記の反応においては、水素ガスが炭化
ケイ素ウィスカーの生成に重要な寄与をなし、本発明に
よれば、反応域における雰囲気が水素ガスを常に７０％
以上とすることによって、炭化ケイ素ウィスカーの収率
を著しく高めると共に、その針状性を著しく高めること
ができる。反応域における雰囲気を常に７０％以上の水
素ガスを含むようにするには、具体的には、例えば、反
応炉中に大量の水素を流通させ、上記したように、副生
ずる一酸化炭素の生成に伴う水素濃度の低減を防止する
。水素ガス濃度が７０％よりも少ないときは、炭化ケイ
素ウィスカーの収量が著しく低減するのみならず、その
長きも短く、また、粉状や屈曲状の炭化ケイ素ウィスカ
ーの生成量が増大する。As described above, in the above reaction, hydrogen gas makes an important contribution to the formation of silicon carbide whiskers, and according to the present invention, the atmosphere in the reaction zone always contains 70% of hydrogen gas.
By doing so, the yield of silicon carbide whiskers can be significantly increased, and the acicularity thereof can be significantly improved. In order to make the atmosphere in the reaction zone always contain 70% or more hydrogen gas, for example, a large amount of hydrogen is passed through the reactor, and as mentioned above, carbon monoxide is generated as a by-product. prevent the reduction in hydrogen concentration associated with When the hydrogen gas concentration is less than 70%, not only the yield of silicon carbide whiskers is significantly reduced, but also the length thereof is short, and the amount of powdered or curved silicon carbide whiskers produced increases.
本発明の方法による炭化ケイ素ウィスカーの製造におい
ては、好ましくは反応触媒が用いられる。In the production of silicon carbide whiskers by the method of the invention, preferably a reaction catalyst is used.
反応触媒としては、鉄、ニッケル、コバルト又はこれら
の化合物、例えば、酸化物、硝酸塩、炭酸塩、硫酸塩等
が用いられる。これら化合物は、粉末、水溶液その他適
宜の形態で炭素含有原料粉末に加え、混在せしめられる
。これら触媒は、特に、前記反応（３）を促進して、直
線状で高純度の炭化ケイ素ウィスカーの生成速度を早め
ると共に、その結果として、併発的に生じる望ましくな
い反応を抑制する作用がある。As the reaction catalyst, iron, nickel, cobalt, or compounds thereof, such as oxides, nitrates, carbonates, sulfates, etc., are used. These compounds are added to and mixed with the carbon-containing raw material powder in the form of powder, aqueous solution, or other appropriate form. In particular, these catalysts have the effect of accelerating the reaction (3) and increasing the rate of production of linear, highly pure silicon carbide whiskers, and as a result, suppressing undesirable reactions that occur concurrently.
本発明の方法において、二酸化ケイ素含有成形体と固体
炭素原料とを水素を含む雰囲気下で加熱する温度は、１
３００℃以上が好適であり、特に、１４００℃以上が好
ましい。１３００℃よりも低い温度では、炭化ケイ素ウ
ィスカーの生成が掘めて遅く、実用上好ましくないから
である。一方、余りに高温であるときは、反応条件が過
激にすぎて、ウィスカー径が肥大化し、また、ウィスカ
ーに分岐や折れ曲がり等の乱れが発生するようになる。In the method of the present invention, the temperature at which the silicon dioxide-containing molded body and the solid carbon raw material are heated in an atmosphere containing hydrogen is 1
The temperature is preferably 300°C or higher, particularly preferably 1400°C or higher. This is because, at a temperature lower than 1300° C., silicon carbide whisker formation is slow and is not practical. On the other hand, when the temperature is too high, the reaction conditions are too extreme, the diameter of the whiskers increases, and disturbances such as branching and bending occur in the whiskers.
従って、反応温度は、通常、１７００℃以下がよい。ま
た、加熱時間は、特に制限されるものではないが、通常
、０．５〜３０時間が適当である。Therefore, the reaction temperature is usually 1700°C or lower. Further, the heating time is not particularly limited, but is usually suitable for 0.5 to 30 hours.
反応時間が余りに短いときは、未反応原料が多量に残留
し、一方、余りに長時間反応させても、炭化ケイ素ウィ
スカーの収量の増加が僅かであるので、生産性及び熱エ
ネルギー費用の観点からみて、何ら利点がないからであ
る。If the reaction time is too short, a large amount of unreacted raw materials will remain; on the other hand, if the reaction time is too long, the yield of silicon carbide whiskers will increase only slightly, so it is difficult from the viewpoint of productivity and thermal energy cost. , because there is no advantage.
上記のように、二酸化ケイ素含有成形体と固体炭素含有
原料とを所定の水素雰囲気下に所定の温度に加熱した後
、これを徐冷若しくは放冷し、好ましくは、反応生成物
に含まれる余剰の炭素を酸化焼却することによって、通
常、綿状の炭化ケイ素ウィスカーを得ることができる。As described above, after heating the silicon dioxide-containing molded body and the solid carbon-containing raw material to a predetermined temperature in a predetermined hydrogen atmosphere, this is slowly cooled or left to cool, and preferably, the surplus contained in the reaction product is By oxidizing and incinerating the carbon, flocculent silicon carbide whiskers can usually be obtained.
光里皇四困
以上のように、本発明の方法によれば、二酸化ケイ素含
有成形体と固体炭素含有原料とを所定濃度以上の高濃度
の水素ガスを含む雰囲気下で加熱することによって、針
状性にすぐれた高純度炭化ケイ素ウィスカーを高収率に
て得ることができる。As described above, according to the method of the present invention, a silicon dioxide-containing molded body and a solid carbon-containing raw material are heated in an atmosphere containing hydrogen gas at a high concentration of at least a predetermined concentration, thereby forming an acicular shape. High purity silicon carbide whiskers with excellent properties can be obtained in high yield.
遺」１媚
以下に実施例を挙げて本発明を説明するが、本発明はこ
れら実施例によって何ら限定されるものではない。The present invention will be described below with reference to Examples, but the present invention is not limited to these Examples in any way.
実施例１
外径２５ｍ、内径２０ｍ、長さ１２０鶴の一端を閉じた
ほぼ円筒状のムライト（シリカ５０％及びアルミナ５０
％）製であって、水素の供給口と排ガス出口とを備えた
反応容器を二酸化ケイ素含有成形体として用い、この反
応容器内に酸化第二鉄０．５重量％を添加したカーボン
ブラック２，５ｇを充填し、管状電気炉に挿入した。こ
の電気炉内に水素ガスを１００ｗ１／分の割合で通気さ
せながら、昇温し、１５００℃の温度で４時間保持した
後、降温した。この間、電気炉の排ガス出口からのガス
の水素濃度は９２％であった。Example 1 A nearly cylindrical mullite with an outer diameter of 25 m, an inner diameter of 20 m, and a length of 120 mm (50% silica and 50% alumina) with one end closed.
%), a reaction vessel equipped with a hydrogen supply port and an exhaust gas outlet was used as a silicon dioxide-containing molded body, and carbon black 2, in which 0.5% by weight of ferric oxide was added to the reaction vessel, 5 g and inserted into a tubular electric furnace. While hydrogen gas was passed through the electric furnace at a rate of 100w1/min, the temperature was raised, held at a temperature of 1500°C for 4 hours, and then lowered. During this period, the hydrogen concentration of the gas from the exhaust gas outlet of the electric furnace was 92%.
次いで、電気炉内から上記反応容器を取り出し、反応容
器内に析出している炭化ケイ素ウィスカーを取り出し、
未反応のカーボンブラックを焼却除去して、屈曲のない
直線状の炭化ケイ素ウィスカー２．５ｇを得た。Next, the reaction vessel is taken out from the electric furnace, and the silicon carbide whiskers deposited inside the reaction vessel are taken out.
Unreacted carbon black was removed by incineration to obtain 2.5 g of straight, unbent silicon carbide whiskers.
実施例２
電気炉内に水素８０％とアルゴン２０％とからなる混合
ガスを供給した以外は、実施例１と同じ方法にて二酸化
ケイ素含有成形体とカーボンブラックとを加熱反応させ
た。この反応の間、電気炉の排ガス出口からＱガスの水
素濃度は７５％であった。この方法によって、屈曲のな
い直線状の炭化ケイ素ウィスカー２．０ｇを得た。しか
し、その長さは、実施例１において得られた炭化ケイ素
ウィスカーに比べれば、幾分短いものであった。Example 2 A silicon dioxide-containing molded body and carbon black were heated and reacted in the same manner as in Example 1, except that a mixed gas consisting of 80% hydrogen and 20% argon was supplied into the electric furnace. During this reaction, the hydrogen concentration of the Q gas from the exhaust gas outlet of the electric furnace was 75%. By this method, 2.0 g of straight silicon carbide whiskers without bending were obtained. However, the length was somewhat shorter than that of the silicon carbide whiskers obtained in Example 1.
比較例１
電気炉内に水素６０％とアルゴン４０％とからなる混合
ガスを供給した以外は、実施例１と同じ方法にて二酸化
ケイ素含有成形体とカーボンブラックとを加熱反応させ
た。この反応の間、電気炉の排ガス出口からのガスの水
素濃度は５８％であった。この方法によれば、粉状物を
含み、しかも、細く、また、長さも実施例１の場合約１
７１０程度の短い炭化ケイ素ウィスカー０．２ｇを得た
にとどまった。Comparative Example 1 A silicon dioxide-containing molded body and carbon black were heated and reacted in the same manner as in Example 1, except that a mixed gas consisting of 60% hydrogen and 40% argon was supplied into the electric furnace. During this reaction, the hydrogen concentration of the gas from the exhaust gas outlet of the electric furnace was 58%. According to this method, it contains powdery material, is thin, and has a length of about 1 in the case of Example 1.
Only 0.2 g of short silicon carbide whiskers of about 710 was obtained.
比較例２
電気炉内にアルゴンを供給した以外は、実施例１と同じ
方法にて二酸化ケイ素含有成形体とカーボンブラックと
を加熱反応させた。この方法によるときは、反応容器と
接触しているカーボンブラックのみが反応に関与するた
めに、炭化ケイ素ウィスカー０．１ｇを得たにとどまっ
た。また、この炭化ケイ素ウィスカーは粉状又は塊状で
あって、針状のものは殆どなかった。Comparative Example 2 A silicon dioxide-containing molded body and carbon black were heated and reacted in the same manner as in Example 1, except that argon was supplied into the electric furnace. When using this method, only 0.1 g of silicon carbide whiskers were obtained because only the carbon black in contact with the reaction vessel took part in the reaction. In addition, the silicon carbide whiskers were powder-like or lump-like, and there were almost no needle-like whiskers.
特許出願人 株式会社神戸製鋼所 同 鐘紡株式会社Patent applicant: Kobe Steel, Ltd. Kanebo Co., Ltd.
Claims (3)
に固体ケイ素含有原料と固体炭素含有原料とを加熱して
、炭化ケイ素ウィスカーを製造する方法において、水素
濃度７０％以上の雰囲気下で二酸化ケイ素を含有する成
形体と炭素含有原料粉末とを１３００〜１７００℃の温
度に加熱することを特徴とする炭化ケイ素ウィスカーの
製造方法。(1) A method for producing silicon carbide whiskers by heating a solid silicon-containing raw material and a solid carbon-containing raw material in the presence of hydrogen gas and a catalyst in a limited reaction space, in an atmosphere with a hydrogen concentration of 70% or more. A method for producing silicon carbide whiskers, which comprises heating a molded body containing silicon dioxide and a carbon-containing raw material powder to a temperature of 1300 to 1700°C.
とする特許請求の範囲第１項記載の炭化ケイ素ウィスカ
ーの製造方法。(2) The method for producing silicon carbide whiskers according to claim 1, characterized in that a catalyst is mixed in the carbon-containing raw material powder.
であることを特徴とする特許請求の範囲第１項記載の炭
化ケイ素ウィスカーの製造方法。(3) The method for producing silicon carbide whiskers according to claim 1, wherein the catalyst is iron, nickel, cobalt, or a compound thereof.
Priority Applications (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61305123A JPS63159299A (en) | 1986-12-20 | 1986-12-20 | Production of silicon carbide whisker |
| US07/096,743 US4873070A (en) | 1986-12-17 | 1987-09-15 | Process for producing silicon carbide whiskers |
| DE8787308276T DE3777577D1 (en) | 1986-12-17 | 1987-09-18 | METHOD FOR PRODUCING SILICON CARBIDE WHISKERS. |
| EP87308276A EP0272773B1 (en) | 1986-12-17 | 1987-09-18 | Process for production silicon carbide whiskers |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61305123A JPS63159299A (en) | 1986-12-20 | 1986-12-20 | Production of silicon carbide whisker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63159299A true JPS63159299A (en) | 1988-07-02 |
| JPH0351679B2 JPH0351679B2 (en) | 1991-08-07 |
Family
ID=17941375
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61305123A Granted JPS63159299A (en) | 1986-12-17 | 1986-12-20 | Production of silicon carbide whisker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63159299A (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57101000A (en) * | 1980-12-12 | 1982-06-23 | Sumitomo Electric Ind Ltd | Preparation of ceramic whisker |
| JPS58120599A (en) * | 1982-01-12 | 1983-07-18 | Onoda Cement Co Ltd | Production of beta-silicon carbide whisker |
-
1986
- 1986-12-20 JP JP61305123A patent/JPS63159299A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57101000A (en) * | 1980-12-12 | 1982-06-23 | Sumitomo Electric Ind Ltd | Preparation of ceramic whisker |
| JPS58120599A (en) * | 1982-01-12 | 1983-07-18 | Onoda Cement Co Ltd | Production of beta-silicon carbide whisker |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0351679B2 (en) | 1991-08-07 |
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