JPH0351679B2 - - Google Patents
Info
- Publication number
- JPH0351679B2 JPH0351679B2 JP61305123A JP30512386A JPH0351679B2 JP H0351679 B2 JPH0351679 B2 JP H0351679B2 JP 61305123 A JP61305123 A JP 61305123A JP 30512386 A JP30512386 A JP 30512386A JP H0351679 B2 JPH0351679 B2 JP H0351679B2
- Authority
- JP
- Japan
- Prior art keywords
- silicon carbide
- carbide whiskers
- carbon
- raw material
- 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.)
- Expired - Lifetime
Links
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical class [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims description 46
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 45
- 238000006243 chemical reaction Methods 0.000 claims description 32
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 31
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 25
- 239000002994 raw material Substances 0.000 claims description 24
- 229910052799 carbon Inorganic materials 0.000 claims description 22
- 239000000377 silicon dioxide Substances 0.000 claims description 22
- 235000012239 silicon dioxide Nutrition 0.000 claims description 19
- 239000001257 hydrogen Substances 0.000 claims description 17
- 229910052739 hydrogen Inorganic materials 0.000 claims description 17
- 238000004519 manufacturing process Methods 0.000 claims description 15
- 239000007787 solid Substances 0.000 claims description 13
- 238000010438 heat treatment Methods 0.000 claims description 11
- 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
- 239000003054 catalyst Substances 0.000 claims description 4
- 238000000034 method Methods 0.000 description 22
- 239000007789 gas Substances 0.000 description 19
- LIVNPJMFVYWSIS-UHFFFAOYSA-N silicon monoxide Chemical compound [Si-]#[O+] LIVNPJMFVYWSIS-UHFFFAOYSA-N 0.000 description 12
- 229910010271 silicon carbide Inorganic materials 0.000 description 8
- 239000006229 carbon black Substances 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
- 238000010532 solid phase synthesis reaction Methods 0.000 description 4
- 229910052786 argon Inorganic materials 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
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- 229910004298 SiO 2 Inorganic materials 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
- 150000001875 compounds Chemical class 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- PUZPDOWCWNUUKD-UHFFFAOYSA-M sodium fluoride Chemical compound [F-].[Na+] PUZPDOWCWNUUKD-UHFFFAOYSA-M 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
- 239000010941 cobalt Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000013078 crystal 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
- 238000001125 extrusion 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
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 description 1
- 229910000041 hydrogen chloride Inorganic materials 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 1
- 229910021421 monocrystalline silicon Inorganic materials 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- 229910052759 nickel 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
- 230000035484 reaction time Effects 0.000 description 1
- 239000012779 reinforcing material Substances 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000741 silica gel Substances 0.000 description 1
- 229910002027 silica gel Inorganic materials 0.000 description 1
- 150000003377 silicon compounds Chemical class 0.000 description 1
- -1 silicon halides Chemical class 0.000 description 1
- 235000013024 sodium fluoride Nutrition 0.000 description 1
- 239000011775 sodium fluoride Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 238000001308 synthesis method Methods 0.000 description 1
- 238000003786 synthesis reaction Methods 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
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Catalysts (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Description
【発明の詳細な説明】
産業上の利用分野
本発明は、炭化ケイ素ウイスカーの製造方法に
関し、詳しくは、高純度であつて、且つ、直線性
にすぐれる針状単結晶炭化ケイ素ウイスカーを高
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
炭化ケイ素ウイスカーは、軽量、高強度、高弾
性を有し、近年、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 ART Silicon carbide whiskers are lightweight, have high strength, and high elasticity, and have recently been expected to be used in various ways as reinforcing materials for composite materials.
このような炭化ケイ素ウイスカーの製造方法と
しては、従来より、気相合成法固相合成法とが代
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
通させることによつて反応炉内に炭化ケイ素ウイ
スカーを生成させる方法（特公昭52−28757号公
報）、二酸化ケイ素、炭素粉末、フツ化ナトリウ
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、炭化ケイ素ウイスカーを析出成長
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、バツチ方式によらざるを
得ず、炭化ケイ素ウイスカーを連続方式にて得る
ことができないので、炭化ケイ素ウイスカーを量
産するには不適当である。 As methods for producing such silicon carbide whiskers, gas phase synthesis and solid phase synthesis are conventionally known as representative methods. 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, and adding hydrocarbons to a reactor containing silicon compounds. A method of producing silicon carbide whiskers in a reactor by circulating a gas such as carbon dioxide or hydrogen chloride (Japanese Patent Publication No. 52-28757), a method in which a crucible filled with silicon dioxide, carbon powder, sodium fluoride, etc. A method of precipitating and growing silicon carbide whiskers by heating in an active atmosphere and reacting vaporized silicon monoxide and carbon monoxide in a low temperature range (Japanese Patent Publication No. 15555/1986, Japanese Patent Application Laid-Open No. 1983-1999)
-100125) etc. are known. However, all of these methods are unsuitable for mass production of silicon carbide whiskers because they must be carried out in batches and silicon carbide whiskers cannot be obtained in a continuous manner.
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、炭化ケイ
素ウイ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
塩料を混合して、成形し、この成形体を匣鉢に入
れてトレープツシヤー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50−25907号公報）等が知られている。
このようなな固相合成法のうち、前者の方法は、
バツチ方式であるために量産には適さない。従つ
て、現在、工業的規模での炭化ケイ素ウイスカー
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 Application Laid-Open No. 1983-1989-1).
No. 145700) A method in which a powdered silicon-containing raw material and a carbon-containing salt are mixed, molded, and the molded body is placed in a sagger and heated in a Trapshear heating furnace (Japanese Patent Laid-Open No. 58-20799, Japanese Patent Application Laid-Open No. 58-91010, Japanese Patent Publication No. 50-25907), etc. are known.
Among these solid phase synthesis methods, the former method is
Since it is a batch method, it is not suitable for mass production. Therefore, the latter continuous production method is currently employed in most cases to produce silicon carbide whiskers on an industrial scale.
しかし、一般に、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イ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イスカーか
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, in general, when solid phase synthesis is used, a large amount of powdered or bent silicon carbide is produced, making it difficult to obtain silicon carbide whiskers with excellent linearity. It is also not easy to separate and remove powdery or bent silicon carbide.
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イスカーの
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つて、直線
性にすぐれた針状短結晶炭化ケイ素ウイスカーを
高収率にて得ることができることを見出して本発
明に至つたものである。Problems to be Solved by the Invention As a result of intensive research in order to solve the above-mentioned problems in the conventional production of silicon carbide whiskers, the present inventors have preformed a silicon raw material containing silicon dioxide, To obtain acicular short-crystal silicon carbide whiskers with excellent linearity in high yield by heating carbon-containing raw material powder together with a carbon-containing raw material powder to a predetermined temperature in an atmosphere containing a predetermined amount of hydrogen in a reaction space. The present invention was achieved by discovering that this can be done.
問題点を解決するための手段
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、炭化ケイ素ウイスカーを製
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。Means for Solving the Problems 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 to a temperature of 1300 to 1700°C in an atmosphere with a hydrogen concentration of 70% or more.
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、造粒等の手段によつ
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 of these. . 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イスカーを得るた
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重量％以上含有すること
が好ましい、
また、固体炭素含有原料とは、カーボンブラツ
クや粉末活性炭、或いはタールやピツチの熱処理
によつて得られる炭素等を用いることができる。 In the present invention, 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, in order to obtain silicon carbide whiskers in a high yield. 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、炭化ケイ素ウイスカー
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
よつて、炭化ケイ素ウイ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. By always maintaining the hydrogen gas concentration at 70% or more in the hydrogen gas atmosphere, silicon carbide whiskers can be obtained at a significantly high yield. Note that the reactor may be, for example,
In the case 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 refers to the reaction zone, and at least this zone of the reactor. The atmosphere in the zone may be maintained at a hydrogen concentration of 70% or more.
かかる本発明の方法においては、炭化ケイ素ウ
イスカーは、次のような反応によつて生成するも
のとみられる。但し、本発明は、反応機構によつ
て何ら制限されるものではない。 In the method of the present invention, silicon carbide whiskers are thought to be produced by the following reaction. However, the present invention is not limited in any way by the reaction mechanism.
Ｃ＋2H2＋CH4 (1)
SiO2＋CH4→SiO＋CO＋2H2 (2)
SiO＋2CH4→SiC＋CO＋4H2 (3)
即ち、先ず、水素ガスと固体炭素原料とが反応
(1)によつ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)によつて
一酸化ケイ素ガスが生成する。次いで、この一酸
化ケイ素ガスとメタンガスとの反応(3)によつて、
炭化ケイ素が生成する。従つて、総括反応式は、
SiO2＋3C→SiC＋2CO (4)
で表わされることとなる。 C+2H 2 +CH 4 (1) SiO 2 +CH 4 →SiO+CO+2H 2 (2) SiO+2CH 4 →SiC+CO+4H 2 (3) That is, first, hydrogen gas and solid carbon raw material react
Methane gas is produced by (1), and silicon monoxide gas is produced by reaction (2) on the surface of the silicon dioxide-containing molded article. Next, through the reaction (3) of this silicon monoxide gas and methane gas,
Silicon carbide is produced. Therefore, the overall reaction formula is expressed as SiO 2 +3C→SiC+2CO (4).
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になら
しめるので、炭化ケイ素ウイ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、炭化ケイ素ウイ
スカーは、気体反応によつて生成するので、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 does not participate in reactions (1) to (3).
Hydrogen gas is essential to the reaction process, as shown in Figure 2. In addition, due to its small molecular size, hydrogen gas easily diffuses within the reaction vessel and facilitates the reduction of silicon dioxide to silicon monoxide and the conversion of carbon to methane gas. This contributes to an increase in the yield of silicon carbide whiskers, and in the method of the present invention, as shown in reaction (4), silicon carbide whiskers are finally This is probably due to its excellent needle-like properties.
以上のように、上記の反応においては、水素ガ
スが炭化ケイ素ウイ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つて、炭
化ケイ素ウイ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通流させ、上記したように、
副生す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、炭化ケイ素ウイスカーの収量が著しく低減
するのみならず、その長さも短く、また、粉状や
屈曲状の炭化ケイ素ウイ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 production of silicon carbide whiskers, and according to the present invention, by keeping the atmosphere in the reaction zone always containing 70% or more hydrogen gas, , it is possible to significantly increase the yield of silicon carbide whiskers and to significantly increase their acicularity. In order to make the atmosphere in the reaction zone always contain 70% or more hydrogen gas, for example, by passing a large amount of hydrogen into the reactor, as described above,
Prevents a reduction in hydrogen concentration due to the production of carbon monoxide as a by-product. 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イスカーの製
造においては、好ましくは反応触媒が用いられ
る。反応触媒としては、鉄、ニツケル、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
度の炭化ケイ素ウイ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。 In the production of silicon carbide whiskers by the method of the invention, preferably a reaction catalyst is used. As a 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) to accelerate the production rate 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、1300℃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、炭化ケイ素ウイスカーの生成が極めて遅く、
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、ウイ
スカー径が肥大化し、また、ウイスカーの分岐や
折れ曲がり等の乱れが発生するようになる。従つ
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。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
素ウイ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。 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 preferably 1300°C or higher, and in particular,
The temperature is preferably 1400°C or higher. At temperatures lower than 1300℃, silicon carbide whisker formation is extremely slow;
This is because it 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 of the whiskers occur. Therefore, the reaction temperature is usually 1700°C or lower. Further, the heating time is not particularly limited, but 0.5 to 30 hours is usually appropriate. If the reaction time is too short, a large amount of unreacted raw materials will remain; on the other hand, if the reaction is too long, the yield of silicon carbide whiskers will increase only slightly, so it is difficult to reduce the productivity and thermal energy costs. , 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つて、通常、線状の炭化ケイ
素ウイ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 Linear silicon carbide whiskers can usually be obtained by oxidizing and incinerating the carbon.
発明の効果
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
することによつて、針状性にすぐれた高純度炭化
ケイ素ウイスカーを高収率にて得ることができ
る。Effects of the Invention As described above, according to the method of the present invention, by heating the silicon dioxide-containing molded body and the solid carbon-containing raw material in an atmosphere containing high concentration hydrogen gas of a predetermined concentration or more, High purity silicon carbide whiskers with excellent properties can be obtained in high yield.
実施例
以上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つて何ら限定されるもの
ではない。EXAMPLES Although the present invention will be described with reference to Examples above, the present invention is not limited to these Examples in any way.
実施例 １
外径25mm、内径20mm、長さ120mm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％）製であつて、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ツク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100ml／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％であつた。Example 1 A reaction vessel made of approximately cylindrical mullite (silica (50% and alumina 50%)) with an outer diameter of 25 mm, an inner diameter of 20 mm, and a length of 120 mm closed at one end and equipped with a hydrogen inlet and an exhaust gas outlet. A container was used as a molded article containing silicon dioxide, and 2.5 g of carbon black to which 0.5% by weight of ferric oxide was added was filled into the reaction container.
It was inserted into a tubular electric furnace. While passing hydrogen gas into this electric furnace at a rate of 100 ml/min, the temperature is raised.
After maintaining the temperature at 1500°C for 4 hours, the temperature was 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イス
カーを取り出し、未反応のカーボンブラツクを焼
却除去して、屈曲のない直線状の炭化ケイ素ウイ
スカー2.5ｇを得た。 Next, the reaction vessel was taken out of the electric furnace, the silicon carbide whiskers precipitated in the reaction vessel were taken out, and the unreacted carbon black was removed by incineration to obtain 2.5 g of straight silicon carbide whiskers without bends. Ta.
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ツク
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75％であつた。
この方法によつて、屈曲のない直線状の炭化ケイ
素ウイスカー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イスカー
に比べれば、幾分短いものであつた。Example 2 A silicon dioxide-containing molded article and carbon black were heated and reacted in the same manner as in Example 1, except that a mixed gas of 80% hydrogen and 20% 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 75%.
By this method, 2.0 g of straight silicon carbide whiskers without bending were obtained. However, its length is
Compared to the silicon carbide whiskers obtained in Example 1, they were somewhat shorter.
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ツク
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％であつた。
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1/10程度の短
い炭化ケイ素ウイスカー0.2ｇを得たにとどまつ
た。Comparative Example 1 A silicon dioxide-containing molded article and carbon black were heated and reacted in the same manner as in Example 1, except that a mixed gas 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, only 0.2 g of silicon carbide whiskers, which contained powdery substances, were thin, and the length was about 1/10 that of Example 1 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
ボンブラツ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
ツクのみが反応に関与するために、炭化ケイ素ウ
イスカー0.1ｇを得たにとどまつた。また、この
炭化ケイ素ウイスカーは粉状又は塊状であつて、
針状のものは殆どなかつた。Comparative Example 2 A silicon dioxide-containing molded article 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. Moreover, this silicon carbide whisker is powdery or lumpy,
There were almost no needle-like objects.
Claims (1)
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、炭化ケイ素ウイ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
る炭化ケイ素ウイスカーの製造方法。 ２ 炭素含有原料粉末に触媒を混在させることを
特徴とする特許請求の範囲第１項記載の炭化ケイ
素ウイスカーの製造方法。[Claims] 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, wherein the hydrogen concentration is 70%. A method for producing silicon carbide whiskers, which comprises heating a silicon dioxide-containing molded body and a carbon-containing raw material powder to a temperature of 1300 to 1700°C in the above atmosphere. 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.
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 |
| EP87308276A EP0272773B1 (en) | 1986-12-17 | 1987-09-18 | Process for production silicon carbide whiskers |
| DE8787308276T DE3777577D1 (en) | 1986-12-17 | 1987-09-18 | METHOD FOR PRODUCING 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 JPS63159299A (en) | 1988-07-02 |
| JPH0351679B2 true 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 |
|---|---|
| JPS63159299A (en) | 1988-07-02 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4619905A (en) | Process for the synthesis of silicon nitride | |
| JPS5913442B2 (en) | Manufacturing method of high purity type silicon nitride | |
| JPH0353279B2 (en) | ||
| EP0272773B1 (en) | Process for production silicon carbide whiskers | |
| JPH0351679B2 (en) | ||
| JPS6122000A (en) | Preparation of silicon carbide whisker | |
| US4975392A (en) | Method for manufacturing silicon carbide whisker | |
| JPH0353280B2 (en) | ||
| JPH0351678B2 (en) | ||
| JPS62260798A (en) | Production of silicon carbide whisker | |
| JPH0448760B2 (en) | ||
| JPH10203818A (en) | Granulated low-oxygen silicone, its production and production of silicon nitride | |
| JPS6126600A (en) | Preparation of beta type silicon carbide whisker | |
| JPS63103898A (en) | Production of silicon carbide whisker of high-quality | |
| JPS63159297A (en) | Production of silicon carbide whisker | |
| JPH0633237B2 (en) | Method for producing high-purity silicon carbide whisker | |
| JPS6272600A (en) | Production of silicon carbide whisker | |
| JPS5945636B2 (en) | Method for manufacturing silicon carbide whiskers | |
| JPH07300399A (en) | Forsterite whisker and its production | |
| JPH042560B2 (en) | ||
| JPH0583518B2 (en) | ||
| JPH03353B2 (en) | ||
| JPH0218399A (en) | Production of silicon carbide whisker | |
| JPH0511047B2 (en) | ||
| JPH0337197A (en) | Production of silicon carbide whisker |