JPS59121198A - Preparation of silicon carbide whisker - Google Patents
Preparation of silicon carbide whiskerInfo
- Publication number
- JPS59121198A JPS59121198A JP57227040A JP22704082A JPS59121198A JP S59121198 A JPS59121198 A JP S59121198A JP 57227040 A JP57227040 A JP 57227040A JP 22704082 A JP22704082 A JP 22704082A JP S59121198 A JPS59121198 A JP S59121198A
- Authority
- JP
- Japan
- Prior art keywords
- carbon
- silicon
- silicon carbide
- mixture
- compound
- 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
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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
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/76—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by a space-group or by other symmetry indications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/80—Compositional purity
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Crystallography & Structural Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Inorganic Chemistry (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
Description
【発明の詳細な説明】 に関するものである。[Detailed description of the invention] It is related to.
ウィスカーとは針状結晶を意味し、単一の針状結晶内の
格子欠陥が皆無に近いので、その機械的強度は、材料に
一期゛待される理想的な最高値に近い強度の素材である
。A whisker is a needle-shaped crystal, and since there are almost no lattice defects within a single needle-shaped crystal, its mechanical strength is close to the ideal maximum expected for the material. It is.
炭化ケイ素は耐熱性、耐蝕性の勝れた化合物である。Silicon carbide is a compound with excellent heat resistance and corrosion resistance.
炭化ケイ素ウィスカーは、これらの性質を併せて有する
機械的強度及び耐熱耐蝕性に勝れた新しい素材であシ、
金属、セラミンクなどに加えてこれらの機械的強度や耐
熱耐蝕性を高める補強剤としての用途が期待されている
。Silicon carbide whiskers are a new material that combines these properties with excellent mechanical strength, heat resistance, and corrosion resistance.
In addition to metals and ceramics, it is expected to be used as a reinforcing agent to increase the mechanical strength, heat resistance, and corrosion resistance of these materials.
従来技術では、炭化ケイ素ウィスカーはＳ ｉ ＣＪ４
、（ ＣＨ３ ）４ ｓｉなどのケイ素化合物と、ＯＨ
４、０３Ｈ９、００４などの炭素化合物の蒸気を水素気
流によって高温雰囲気の反応器に搬送し、気相で反応さ
せた後、反応器の下流側の低温部に析出させて得る方法
が知られている。しかし、この方法ではケイ素化合物が
少なからずそのままガス状態で反応の系外に揮散する点
と、大量の水素の供給を必要とする問題点があり、また
炭化ケイ素ウィスカーの析出設備は、小型のバッチ方式
から工業的な生産に適する大型化にすることが困難な欠
点があった。In the prior art, silicon carbide whiskers are Si CJ4
, (CH3)4si and other silicon compounds, and OH
There is a known method in which vapors of carbon compounds such as 4, 03H9, and 004 are transported by a hydrogen stream to a reactor in a high-temperature atmosphere, reacted in the gas phase, and then precipitated in a low-temperature section on the downstream side of the reactor. There is. However, this method has the problem that a considerable amount of the silicon compound evaporates out of the reaction system in a gaseous state, and that a large amount of hydrogen is required to be supplied.Additionally, the silicon carbide whisker precipitation equipment is not suitable for small batch production. Due to the method, it was difficult to make it large enough for industrial production.
また固体の原料から炭化ケイ素ウィスカーが生成する例
としては、ケイ石とコークスとを粉砕、混合したものを
アチソン炉を用いて強熱する炭化ケイ素の製造工程にお
いて、生成した炭化ケイ素インゴットに局部的に付着し
た炭化ケイ素ウィスカーが観察されることは従来よシ知
られている。しかし、ケイ素換算での収率は０．１係に
も満たないものであった。In addition, as an example of silicon carbide whiskers being generated from solid raw materials, in the silicon carbide manufacturing process in which a mixture of silica stone and coke is ignited using an Acheson furnace, there are It has been known for a long time that silicon carbide whiskers can be observed attached to. However, the yield in terms of silicon was less than 0.1%.
本発明者らは、これら従来技術の得失を充分に検討した
結果、ケイ素化合物、炭素化合物及び・水素から直接炭
化ケイ素ウィスカーを得る従来の方法とは異なる方法、
即ち充分に均一性が高く、かつ構成粒度の細かいケイ素
酸化物と炭素を含む混合物を製造し、これを特定の状態
で加熱すれば、目的とする炭化ケイ素ウィスカーがケイ
素換算での収率で１００％近くの高収率で得られること
を見出し、本発明に到った。As a result of thorough consideration of the advantages and disadvantages of these conventional techniques, the present inventors have discovered a method different from the conventional method of directly obtaining silicon carbide whiskers from silicon compounds, carbon compounds, and hydrogen.
In other words, if a mixture containing silicon oxide and carbon with sufficiently high uniformity and fine particle size is produced and heated under a specific condition, the desired silicon carbide whiskers can be produced in a yield of 100% in terms of silicon. It has been found that it can be obtained with a high yield of nearly 1.9%, and has led to the present invention.
即ち本発明は、炭化ケイ素ウィスカーの新規な製造法で
あって、水蒸気を含む熱ガス中に、分解性のケイ素化合
物と炭素化合物を装入して、ケイ素酸化物と炭素を含む
混合物（以下単Ｋ「微細含炭素混合物」と略称する）で
、その嵩比重が０，２２／ｃｃ以下の含炭素混合物を加
熱することを特徴とするものである。そして、本発明に
おいて微細含炭素混合物の比表面積が２ ｓ ｒｎ’
／ ｙ以上であることは、一層よく本発明の目的を達す
ることができる。That is, the present invention provides a novel method for producing silicon carbide whiskers, in which a decomposable silicon compound and a carbon compound are charged into a hot gas containing water vapor to form a mixture containing silicon oxide and carbon (hereinafter simply referred to as "silicon carbide whisker"). This method is characterized by heating a carbon-containing mixture having a bulk specific gravity of 0.22/cc or less. In the present invention, the specific surface area of the fine carbon-containing mixture is 2 s rn'
/y or more can better achieve the object of the present invention.
比表面積とは、粉体状固形物の平均粒子径を簡便に示す
尺度として用いられるが、粉体状固形物はそれぞれ固有
の形状、粒子径分布を有するため、粉体全体について粒
子径、粒子径分布を正確に測定し、表示することは極め
て困難である。このため固形物の表面に吸着する物質例
えば窒素ガスの量を測定し、これを平均粒子径に対応す
る尺度として用いることが便オリに行なわれている。窒
素吸着比表面積が大きいことは、即ち平均粒子径が小さ
いことを意味する。The specific surface area is used as a simple measure of the average particle diameter of powdered solids, but since each powdered solid has its own unique shape and particle size distribution, Accurately measuring and displaying diameter distribution is extremely difficult. For this reason, it has been convenient to measure the amount of a substance, such as nitrogen gas, adsorbed on the surface of a solid material and use this as a measure corresponding to the average particle diameter. A large nitrogen adsorption specific surface area means a small average particle diameter.
本発明の詳細な説明すると、まず単体炭素のエーロゾル
は、分解性の炭素化合物を熱ガス中に装入して容易に得
ることができる。他方、ケイ素酸化物のエーロゾルは、
例えば８ｉ（至）４の如き分解性のケイ素化合物を水蒸
気を含む熱ガス中に装入すると、加水分解、熱分解ある
いは酸化によシ得ることができる。To explain the present invention in detail, first, an aerosol of elemental carbon can be easily obtained by charging a decomposable carbon compound into hot gas. On the other hand, silicon oxide aerosol is
When a decomposable silicon compound such as 8i4 is introduced into a hot gas containing water vapor, it can be hydrolyzed, pyrolyzed or oxidized.
容易に理解できるように、水蒸気を含む熱ガス中に炭素
化合物及びケイ素化合物を同時に装入すれば、直ちに単
体炭素とケイ素酸化物を含む混合エーロゾルとなる。As can be easily understood, if a carbon compound and a silicon compound are simultaneously charged into a hot gas containing water vapor, a mixed aerosol containing elemental carbon and silicon oxide is immediately formed.
本発明で使用しうるケイ素化合物としては、一般式５ｉ
ｎＸ２．１＋２（ｎは１から４の整数）で表わされるも
ので、Ｘは水素もしくはハロゲン原子またはアルキル基
もしくはアルコキシル基であり、具体的なケイ素化合物
を挙げればＳｉ（至）４、Ｈ８１（至）３、ＳｉＨ４、
Ｓｉ２Ｈ６、（ＯＨ３）４ Ｓｉ、 （ＯＨ３）２Ｓｉ
ＣＪ２、ＯＨ３Ｓ ｉ（至）３．５ｉＰ４、Ｓ ｉ （
００２Ｈｓ ）４などであシ、またこれらの混合物であ
っても本発明には何等の支障もない。As silicon compounds that can be used in the present invention, general formula 5i
n )3, SiH4,
Si2H6, (OH3)4Si, (OH3)2Si
CJ2, OH3S i (to) 3.5iP4, S i (
002Hs)4, etc., or a mixture thereof, there is no problem in the present invention.
本発明に用いうる炭素化合物は、そのままで気相可能で
ある。炭化水素の例としてはメタノール、エタノール、
アセトン、ｎ−ヘキサン、ベンゼン、キシレンなどの石
油化学生成物、ナフサ、プロパン、軽油、灯油、重油な
どの石油類などかあシ、石油ピッチ、メチル油、アント
ラセン油、クレオソート油などの精製残留物、０，９留
分混合物、エチレンボトムなどの石油化学残留物でも使
用可能である。ハロゲン化炭化水素の例としてはクロロ
ホルム、塩化ビニル、クロルベンゼンナトかアシ、・・
ロゲン化炭素の例としては四塩化炭素がある。The carbon compound that can be used in the present invention can be used as it is in a gas phase. Examples of hydrocarbons are methanol, ethanol,
Petrochemical products such as acetone, n-hexane, benzene, xylene, etc., petroleum products such as naphtha, propane, light oil, kerosene, heavy oil, etc. Refined residues such as limestone, petroleum pitch, methyl oil, anthracene oil, creosote oil, etc. It is also possible to use petrochemical residues such as oil, 0.9 fraction mixtures, and ethylene bottoms. Examples of halogenated hydrocarbons are chloroform, vinyl chloride, chlorobenzenate, etc.
An example of carbon chloride is carbon tetrachloride.
本発明では炭素化合物は炭素の供給が目的であるから、
その種類は広範囲に選択可能であるｏしかし取扱いの簡
便さ、炭素収率の面からトルエン２、キシレン、ベンゼ
ン、灯油、軽油、重油、Ｃ９留分混合物、エチレンボト
ムなどが好ましい。In the present invention, since the purpose of the carbon compound is to supply carbon,
The type thereof can be selected from a wide range; however, from the viewpoint of ease of handling and carbon yield, toluene 2, xylene, benzene, kerosene, light oil, heavy oil, C9 fraction mixture, ethylene bottoms, etc. are preferred.
本発明に用いる微細含炭素混合物を得るには炉を用いる
のが好適である。It is preferable to use a furnace to obtain the fine carbon-containing mixture used in the present invention.
この炉には、加熱装置及びケイ素化合物、炭素化合物の
装入用ノズルと、ガス装入ダクト、混合エーロゾル排出
ダクトとが具備されており、加熱装置としては燃焼バー
ナー通電発熱体などがある・が、燃焼バーナーが簡便で
あシ、また熱効率の面でも好ましい。第１図はこれに用
いる炉の１例を示すものである。This furnace is equipped with a heating device, a nozzle for charging silicon compounds and carbon compounds, a gas charging duct, and a mixed aerosol discharge duct.The heating device includes a combustion burner, an energized heating element, etc. A combustion burner is preferable because it is simple and thermally efficient. FIG. 1 shows an example of a furnace used for this purpose.
この炉内には少なくとも７００℃以上の空間領域がなけ
ればならない。この温度以上であれば炭素化合物からは
炭体炭素が、更に水蒸気を含む雰囲気下でケイ素化合物
からはケイ素酸化物が得られ、気体とこれら固形物との
混合体である混合エーロゾル状態を発生する。Inside this furnace there must be a spatial region with a temperature of at least 700°C or higher. At temperatures above this temperature, carbonaceous carbon is obtained from carbon compounds, and silicon oxide is obtained from silicon compounds in an atmosphere containing water vapor, creating a mixed aerosol state that is a mixture of gas and these solids. .
なおケイ素酸化物に加えて、単体ケイ素あるいはケイ素
ハライドが挟在していても、本発明の目的とする炭化ケ
イ素ウィスカーを得るのに格別の妨げにはな゛らない。Incidentally, even if elemental silicon or silicon halide is interposed in addition to silicon oxide, it will not be a particular hindrance to obtaining the silicon carbide whiskers that are the object of the present invention.
水蒸気を含む熱ガスを得る方法としては、通電発熱方式
、高周波加熱方式、放電方式によって得た熱ガス中に、
水蒸気を注入することによっても得ることができるが、
水素、メタン、エタン、プロパンなどあるいは原料とす
る炭化水素のように燃焼して水蒸気を生成する可燃物を
空気で燃焼させる方法が装置上簡便であシ、熱効率の面
から経済本発明の実施に用いられ２ケイ素化合物として
は、熱ガス中で熱分解反応によって単体ケイ素の固形物
に変化する性質に゛加えて、水蒸気との加水分解反応に
よってケイ素酸化物に変化する性質を有するものを用い
るので、熱と水蒸気が共存する雰囲気下では、ケイ素化
合物がガス状態のままで反応の系外に揮散することを防
ぐことができる。Methods for obtaining hot gas containing water vapor include hot gas obtained by energization heating method, high frequency heating method, and discharge method.
It can also be obtained by injecting water vapor, but
A method of burning combustible substances such as hydrogen, methane, ethane, propane, etc. or hydrocarbons as raw materials, which produce water vapor by combustion, with air is simple in terms of equipment, and is economical from the standpoint of thermal efficiency to carry out the present invention. The 2-silicon compound used is one that has the property of converting into a solid substance of elemental silicon through a thermal decomposition reaction in hot gas, and also the property of changing into silicon oxide through a hydrolysis reaction with water vapor. In an atmosphere where heat and water vapor coexist, it is possible to prevent the silicon compound from evaporating out of the reaction system while remaining in a gaseous state.
生成した混合エーロゾルは、炉の系外に誘導した後、含
まれる固形物をバッグフィルター、サイクロン、電気業
じん機等の捕集装置で捕集する。The generated mixed aerosol is guided out of the furnace system, and then the solids contained therein are collected by a collection device such as a bag filter, cyclone, or electric dust machine.
捕集された微細含炭素混合物は、高周波加熱炉、通電抵
抗炉、直火式管状加熱炉などを用いて１４００℃から１
９００℃好ましくは１５００から１７００℃に加熱する
ことによって、炭化ケイ素ウィスカーとすることができ
る。The collected fine carbon-containing mixture is heated from 1400°C to 1°C using a high-frequency heating furnace, current-carrying resistance furnace, direct-fired tubular heating furnace, etc.
Silicon carbide whiskers can be obtained by heating to 900°C, preferably 1500 to 1700°C.
本発明において、微細含炭素混合物の比表面積は２５ｒ
ｒ？／ｆ以上であることは一層好ましい。その理由は、
比表面積が２５ｄ／ｆ以下であると、これを加熱して得
られる炭化ケイ素にはや３粒状なのが混入しがちとなる
という本発明者らの実験的知見に基づくものである。In the present invention, the specific surface area of the fine carbon-containing mixture is 25r
r? It is more preferable that it is equal to or greater than /f. The reason is,
This is based on the inventors' experimental findings that when the specific surface area is 25 d/f or less, silicon carbide obtained by heating the silicon carbide tends to contain particles in the form of particles.
この理由は詳らかにし得ないが、恐らくは、窒素吸着量
の小さい、即ち粒子径の大きい微細含炭素混合物におい
ては、その混合エーロゾルの段階において、ケイ素酸化
物および単体炭素の粒子径が太きいために、それぞれの
単一粒子の移動速度が比較的遅く、ケイ素酸化物と単体
炭素の混合形態が均一々ものになシにくいためではない
かと推察される。The reason for this cannot be explained in detail, but it is probably because in a fine carbon-containing mixture with a small amount of nitrogen adsorption, that is, a large particle size, the particle size of silicon oxide and elemental carbon is large in the mixed aerosol stage. It is speculated that this is because the movement speed of each single particle is relatively slow, and the mixed form of silicon oxide and elemental carbon is difficult to break even if the mixture is uniform.
微細含炭素混合物の嵩比重は加熱する前の段階において
０．２５’１０ｃ１好ましくは０．１５２７’ｃｃ以下
が必要である。The bulk specific gravity of the fine carbon-containing mixture is required to be 0.25'10 cc or less, preferably 0.1527' cc or less, before heating.
その理由は、嵩比重が０．２ｆ／Ｃｔ以上であると、加
熱して得られる炭化ケイ素が粒状あるいは彎曲した形状
となシ易い傾向が急激に増大するという本発明者らの実
験的知見に基づくものである。The reason for this is based on the experimental findings of the present inventors that when the bulk specific gravity is 0.2 f/Ct or more, the tendency of silicon carbide obtained by heating to form a granular or curved shape increases rapidly. It is based on
この理由は詳らかにし得ないが、恐らくは、反応中間生
成物として一旦ＳｉＯが生成し、８ｉ０が更に炭素と反
応して炭化ケイ素となる反応過程において、ＳｉＯの移
動可能距離が長い方がＳｉＯの炭化ケイ素ウィスカーの
成長活性点に移行する確率が高くなると推察され、移動
距離が長いことが空間容積が大きいこと、即ち嵩比重が
小さいことに対応するためと推察される。The reason for this cannot be explained in detail, but it is probably that in the reaction process in which SiO is once produced as a reaction intermediate product and 8i0 further reacts with carbon to form silicon carbide, the longer the distance that SiO can move, the more likely it is that SiO will be carbonized. It is presumed that the probability of migration to active sites of silicon whisker growth increases, and it is presumed that this is because a long migration distance corresponds to a large spatial volume, that is, a small bulk specific gravity.
混合物を加熱する工程において、酸素が雰囲気中に存在
すると単体炭素が燃焼除去されるため、アルゴン、ヘリ
ウム、窒素、水素などの非酸化性雰囲気中で加熱するこ
とが好ましい。しかしこのことは、加熱段階でケイ素酸
化物と単体炭素が反応し、炭化ケイ素が生成すると同時
に一酸化炭素が生成しておのずと非酸化性雰囲気となる
庭め、本発明に分いて特定するところでは々い。In the step of heating the mixture, if oxygen is present in the atmosphere, elemental carbon will be burned and removed, so it is preferable to heat the mixture in a non-oxidizing atmosphere such as argon, helium, nitrogen, or hydrogen. However, this is because silicon oxide and elemental carbon react during the heating step, producing silicon carbide and carbon monoxide at the same time, naturally creating a non-oxidizing atmosphere. Many.
微細含炭素混合物の嵩比重は０．２ｆ／ｃｃ以下が必要
な点において、生成した混合エーロゾルから含炭素混合
物を捕集し、加熱するまでの工程は、含炭素混合物が緊
縮される工程を出来るだけ除くことが望ましい。この意
味において、混合エーロゾルよシ微細含炭素混合物を捕
集する方法としては、バッグフィルター、電気業じん器
、サイクロンなどがあるが、水など液体の粉体を凝集さ
せる性質をオリ用した捕集装置である湿式電気集じん器
、湿式サイクロンなどは適しない。Since the bulk specific gravity of the fine carbon-containing mixture must be 0.2 f/cc or less, the process of collecting the carbon-containing mixture from the generated mixed aerosol and heating it can be a process in which the carbon-containing mixture is compressed. It is desirable to remove only In this sense, methods for collecting fine carbon-containing mixtures using mixed aerosols include bag filters, electric dust generators, and cyclones. Equipment such as wet electrostatic precipitators and wet cyclones are not suitable.
この理由は、折角の微粉の含炭素混合物でも水々どに分
散させてスラリー状態とし、これを乾燥したものは粒子
の凝集が起ておりしかも嵩比重がｏ、ａｙ／ｃｃ以上の
ケーク状態となシ易く、これを解砕やふるい振とうなど
を行なったとしても嵩比重は０．２ｆ／ｃｃ以下にはな
りにくいからである０本発明においては、微細含炭素混
合物の比表面積は２５ ？ｌＬ’ ／ ９以上であるこ
とが一層好ましいが、一般的に云ってこの比表面積は原
料とするケイ素化合物および炭素花合物の炉内への装入
量を多くすると低くなシ、少くすると高く彦る傾向にあ
る。The reason for this is that even finely powdered carbon-containing mixtures are dispersed in water to form a slurry, and when this is dried, the particles are agglomerated and the bulk density is more than o, ay/cc. In the present invention, the specific surface area of the fine carbon-containing mixture is 25? It is more preferable that the specific surface area be 1L'/9 or more, but generally speaking, this specific surface area decreases as the amount of silicon compounds and carbon composites used as raw materials charged into the furnace increases, and increases as it decreases. There is a tendency to fall.
つマシ第１図に示した炉において、空気および燃料の供
給量を一定にしておいて、ノズル（４）からのケイ素化
合物および炭素化合物の装入量を増減させることで調整
することができる。In the furnace shown in FIG. 1, the amount of air and fuel supplied can be kept constant and adjusted by increasing or decreasing the amount of silicon compound and carbon compound charged from the nozzle (4).
本発明はこのように、比較的簡略な方法で炭化ケイ素ウ
ィスカーを高収率で製造する方法でｓｂ、大量生産に適
する安価な製造法を提供するものでちる。The present invention thus provides a relatively simple method for producing silicon carbide whiskers in high yield, and provides an inexpensive production method suitable for mass production.
ウィスカーは、これを金属、セラミックなどに加える補
強剤として用いる場合、鍼・曲のない直線状の形態であ
ることが、例えば金属中での分散状態が均一になシ易い
点で望ましいとされている。また、直径（Ｄ）に対する
長さくＬ）の比（Ｌ／Ｄ）が大きい程、補強剤としての
効果が太きいとされている。When whiskers are used as a reinforcing agent to be added to metals, ceramics, etc., it is desirable that the whiskers be in the form of a straight line with no needles or curves, as this facilitates uniform dispersion in the metal. There is. Further, it is said that the larger the ratio (L/D) of the length L to the diameter (D), the greater the effect as a reinforcing agent.
本発明では、電子顕微鏡映像をもとに、Ｌ／Ｄの算術平
均値をウィスカーの形態評価因子とした。In the present invention, the arithmetic mean value of L/D was used as a whisker morphology evaluation factor based on electron microscope images.
以下実施例を示して本発明を具体的に説明する。The present invention will be specifically described below with reference to Examples.
実施例１゜
第１図に示す炉（直径３００那、長さ３ｆｎ）を用い、
ダクト（２）よシ空気を、燃焼バーナー（３）よシ熱風
用燃料としての水素を夫々８０ Ｎ７７ｊ／Ｈ，１２Ｎ
７１１／Ｈの流量で装入し、またケイ素化合物としてＳ
ｉ （１１３４を、炭素化合物としてＣ９留分混合物
を予め重量比で１：１に混合したものを１４Ｋｐ／Ｈの
流量でノズル（４）よシ炉内に装入した。炉内は第１図
のＡの位置で１０００〜１１００℃の温度に保つた。炉
内で生成したエーロゾルはダクト（５）より抜き出し、
バッグフィルターで分散質を捕集して微細含炭素混合物
４．８ Ｋ９／ Ｈ（乾燥重量）を得た。Example 1 Using the furnace shown in Figure 1 (diameter 300mm, length 3fn),
Air from the duct (2) and hydrogen as hot air fuel from the combustion burner (3), respectively 80 N77j/H, 12N
711/H, and S as a silicon compound.
i (1134) was preliminarily mixed with a C9 fraction mixture at a weight ratio of 1:1 as a carbon compound and charged into the furnace through the nozzle (4) at a flow rate of 14 Kp/H.The interior of the furnace is shown in Figure 1. The temperature was maintained at 1000 to 1100°C at position A.The aerosol generated in the furnace was extracted from the duct (5),
The dispersoids were collected using a bag filter to obtain a fine carbon-containing mixture of 4.8 K9/H (dry weight).
このものには炭素４８，５重量％、ケイ素２４．０重量
％（単体換算）が含まれ（残シは結合性の酸素２７．４
重量％、炭素付着の水素０．１重量％、その他０．１重
量％以下）、Ｂ５０Ａスペクトル解析の結果、ケイ素と
他元素との結合形態には８ｉ−０結合のみ）が観察され
た。微細含炭素混合物の窒素吸着比表面積の測定はＡ８
ＴＭ Ｄ３０３７−７８に従って行ない、４８．５ ｒ
ｒ？／ｌであった。This material contains 48.5% by weight of carbon and 24.0% by weight of silicon (calculated as a single element) (the balance is 27.4% by weight of binding oxygen).
As a result of B50A spectrum analysis, only 8i-0 bond) was observed in the bond form between silicon and other elements. Measurement of nitrogen adsorption specific surface area of fine carbon-containing mixture is A8
Performed according to TM D3037-78, 48.5 r
r? /l.
バッグフィルターより取り出しだ微細含炭素混合物の嵩
比重は０．０８８ｆ／ｃｃであった。The bulk specific gravity of the fine carbon-containing mixture taken out from the bag filter was 0.088 f/cc.
これの３Ｏｆを黒鉛ルツボに装入し、アルゴン雰囲気中
１６００℃２時間加熱し、一旦冷却後空気中で７００℃
に加熱して、残存した単体炭素を空気中で燃焼除去し、
炭化ケイ素９．７ｆを得た。粉末Ｘ線回折スペクトル解
析の結果、結晶形状はβ型であシ、電子顕微鏡映偉観、
察の結果、針状のウィスカーのみが観察され、Ｌ／Ｄは
６２で、あった。3Of of this was charged into a graphite crucible, heated at 1600℃ for 2 hours in an argon atmosphere, and once cooled, heated to 700℃ in air.
The remaining elemental carbon is removed by combustion in the air.
9.7f of silicon carbide was obtained. As a result of powder X-ray diffraction spectrum analysis, the crystal shape was β-type, as observed by electron microscopy.
As a result of inspection, only needle-like whiskers were observed, and L/D was 62.
第２図にその映像を示す。Figure 2 shows the image.
微細含炭素混合物中のケイ素が炭化ケイ素に転換した割
合は、単体元素換算で９５％と算出された。The conversion rate of silicon in the fine carbon-containing mixture to silicon carbide was calculated to be 95% in terms of a single element.
比較例１゜
実施例１．と全く同様にして生成させた混合エーロゾ四
をダクト（５）よシ抜き出し、湿式サイクロンを用いて
、水１００重量部に分散質が１５重量部分散されたスラ
リー状態で含炭素混合物を捕集した。Comparative example 1゜Example 1. The mixed aerosol 4 produced in exactly the same manner as above was extracted through the duct (5), and a carbon-containing mixture was collected using a wet cyclone in the form of a slurry in which 15 parts by weight of the dispersoid was dispersed in 100 parts by weight of water. .
これをｆ過、乾燥して得た含炭素混合物には炭素４８．
７重量％、ケイ素２３．９重量％が含まれ（残シは結合
性の酸素２７．３重量％、炭素付着の水素０．１重量％
、その他０１重量係以下）、嵩比重は０．４２ｆ／ｃｃ
でケーク状であった。これをふるい振とり器で解砕しな
がら６０メツシユの金網に通過させて得た嵩比重が０．
２６ｆ／ｃｃの含炭素混合物３０ｔを実施例１．と全く
同様にして加熱し、炭化ケイ氷９，９ｔを得た。粉末Ｘ
線回折スペクトル解析の結果、結晶形状はβ型であシ、
電子顕微鏡映像観察の結果、粒状の形状のもののみが観
察された。The carbon-containing mixture obtained by filtering and drying this had 48% carbon.
7% by weight and 23.9% by weight of silicon (the balance is 27.3% by weight of bonding oxygen and 0.1% by weight of hydrogen attached to carbon).
, other 01 weight ratio or less), bulk specific gravity is 0.42f/cc
It was cake-like. The bulk specific gravity obtained by passing this through a 60-mesh wire mesh while crushing it with a sieve shaker was 0.
30 tons of 26f/cc carbon-containing mixture was prepared in Example 1. It was heated in exactly the same manner as above to obtain 9.9 tons of carbide silicon ice. powder
As a result of line diffraction spectrum analysis, the crystal shape is β type.
As a result of electron microscope image observation, only granular shapes were observed.
実施例２゜
比較例１で得られた嵩比重が０．４２ｆ／＆のケーク状
の含炭素混合物をふるい振とう器で解砕しながら２００
メツシユの金網に通過さ・せて得た嵩比重が０．１ ’
８ ｙ ／ｃｃの含炭素混合物３０りを実施例１、と全
く同様にして加熱し、炭化ケイ素９．８ｆを得た。電子
顕微鏡映像観察の結果、その形態は彎曲した形状と針状
のもの及び粒状のものとの混合形態であシ、Ｌ／Ｄは２
９であった。Example 2 The cake-like carbon-containing mixture obtained in Comparative Example 1 and having a bulk specific gravity of 0.42 f/& was crushed with a sieve shaker while
The bulk specific gravity obtained by passing through the mesh wire mesh is 0.1'
Thirty grams of a carbon-containing mixture of 8 y /cc was heated in exactly the same manner as in Example 1 to obtain 9.8 f of silicon carbide. As a result of electron microscope image observation, the morphology was a mixture of curved, needle-like, and granular, and the L/D was 2.
It was 9.
実施例３〜６
実施例１゜における熱風用燃料には、水素の他にメタン
、プロパンも用い、分解性のケイ素化合物、炭素化合物
としては表１に示すものを、表１に示す重量比で混合し
てノズル（４）より炉内に装入し、それぞれバッグフィ
ルターで捕集して、それぞれ表１に示す組成、嵩比重の
微細含炭素混合物を得た。これらそれぞれ３０ｆを実施
例１．と同様にして高周波加熱炉を用いてアルゴン雰囲
気中で、それぞれ表２に示す温度と時間の加熱を行ない
、一旦冷却後空気中で７００℃に加熱して残、存した単
化ケイ素を得た。Examples 3 to 6 In addition to hydrogen, methane and propane were used as the fuel for hot air in Example 1°, and decomposable silicon compounds and carbon compounds shown in Table 1 were used at the weight ratios shown in Table 1. The mixture was charged into a furnace through a nozzle (4), and each was collected using a bag filter to obtain a fine carbon-containing mixture having the composition and bulk specific gravity shown in Table 1. Each of these 30f was used in Example 1. In the same manner as above, heating was performed in an argon atmosphere using a high-frequency heating furnace at the temperatures and times shown in Table 2, and after cooling, the remaining silicon monoxide was obtained by heating to 700°C in air. .
粉末Ｘ線回折スペクトル解析の結果、結晶形状はいずれ
もβ型であシ、電子顕微鏡映像観察の結果、その形態は
実施例３．においては針状のウィスカーに加えて粒状の
ものが、実施例４．〜６はいずれも針状のウィスカーの
みが観察された。それぞれのＬ／Ｄは表２に示した通シ
であった。第３図に、実施例３．で得た炭化ケイ素の電
子顕微鏡映像を示す。As a result of powder X-ray diffraction spectrum analysis, the crystal shape was β-type in all cases, and as a result of electron microscope image observation, the morphology was that of Example 3. In Example 4, granular whiskers were used in addition to needle-like whiskers. -6, only needle-like whiskers were observed. Each L/D was as shown in Table 2. FIG. 3 shows Example 3. This shows an electron microscope image of silicon carbide obtained in .
加熱した微細含炭素混合物中の単体換算でのケイ素が炭
化ケイ素に転換した割合はそれぞれ表２に示した通シで
あった。The ratio of silicon converted into silicon carbide in terms of a single substance in the heated fine carbon-containing mixture was as shown in Table 2.
表 ２Table 2
第１図は、本発明の実施に使用する炉の断面図の１例を
示したものである。
図面において
１・・・炉材、 ２・・・ダクト、 ３・・・燃焼バ
ーナー、４・・ノズル、 ５・・・ダクト を示す。
第２，３図は走査型電子顕微燥を用いて撮影した炭化ケ
イ素の拡大写真を示す。倍率はいずれも２０００倍でお
る。
第２，３図はそれぞれ実施例１，３で得た炭化ケイ素の
拡大写真である。
特許出願人
三井東圧化学株式会社
第 １ 図
第 ２ 図
第 ３ 図FIG. 1 shows an example of a cross-sectional view of a furnace used in carrying out the present invention. In the drawing, 1...Furnace material, 2...Duct, 3...Combustion burner, 4...Nozzle, 5...Duct are shown. Figures 2 and 3 show enlarged photographs of silicon carbide taken using a scanning electron microscope. The magnification is 2000x in both cases. Figures 2 and 3 are enlarged photographs of silicon carbide obtained in Examples 1 and 3, respectively. Patent applicant Mitsui Toatsu Chemical Co., Ltd. Figure 1 Figure 2 Figure 3
Claims (1)
び炭素化合物を装入し、ケイ素酸化物と単体炭素を含む
混合エーロゾルを生成させて、この分散質を捕集して得
た窩比重が０．２ ｆ ／ ｃｃ以下の微細含炭素混合
物を加熱する仁とを特徴とする炭化ケイ素ウィスカーの
製造法。 ２）微細含炭素混合物の比表面積が２Ｆｍ”７９以上で
あることを特徴とする特許請求の範囲第１項に記載の方
法。[Claims] l) A decomposable silicon compound and a carbon compound are charged into hot gas containing water vapor to generate a mixed aerosol containing silicon oxide and elemental carbon, and this dispersoid is collected. 1. A method for producing silicon carbide whiskers, comprising: heating a fine carbon-containing mixture having a specific gravity of 0.2 f/cc or less. 2) The method according to claim 1, wherein the specific surface area of the fine carbon-containing mixture is 2Fm''79 or more.
Priority Applications (7)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57227040A JPS59121198A (en) | 1982-12-27 | 1982-12-27 | Preparation of silicon carbide whisker |
| US06/886,768 US4752456A (en) | 1982-06-01 | 1983-06-01 | Process for preparing metal carbides and precursors thereof |
| DE8383901729T DE3381007D1 (en) | 1982-06-01 | 1983-06-01 | METHOD OF PRODUCING METAL CARBIDES AND THEIR PRE-PRODUCTS. |
| PCT/JP1983/000180 WO1983004188A1 (en) | 1982-06-01 | 1983-06-01 | Process for manufacturing metal carbides and their precursors |
| EP83901729A EP0111008B1 (en) | 1982-06-01 | 1983-06-01 | Process for manufacturing metal carbides and their precursors |
| CA000436445A CA1214309A (en) | 1982-09-14 | 1983-09-12 | Process for preparing metal carbides and precursors thereof |
| IT48972/83A IT1170492B (en) | 1982-09-14 | 1983-09-13 | Metal carbide and metal carbide precursor mfr. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57227040A JPS59121198A (en) | 1982-12-27 | 1982-12-27 | Preparation of silicon carbide whisker |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59121198A true JPS59121198A (en) | 1984-07-13 |
| JPS612640B2 JPS612640B2 (en) | 1986-01-27 |
Family
ID=16854581
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57227040A Granted JPS59121198A (en) | 1982-06-01 | 1982-12-27 | Preparation of silicon carbide whisker |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59121198A (en) |
-
1982
- 1982-12-27 JP JP57227040A patent/JPS59121198A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS612640B2 (en) | 1986-01-27 |
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