JPH0621023B2 - Method for producing fine particles of silicon carbide - Google Patents
Method for producing fine particles of silicon carbideInfo
- Publication number
- JPH0621023B2 JPH0621023B2 JP63079227A JP7922788A JPH0621023B2 JP H0621023 B2 JPH0621023 B2 JP H0621023B2 JP 63079227 A JP63079227 A JP 63079227A JP 7922788 A JP7922788 A JP 7922788A JP H0621023 B2 JPH0621023 B2 JP H0621023B2
- Authority
- JP
- Japan
- Prior art keywords
- fine particles
- laser
- gas
- sic
- silicon carbide
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B32/00—Carbon; Compounds thereof
- C01B32/90—Carbides
- C01B32/914—Carbides of single elements
- C01B32/956—Silicon carbide
- C01B32/963—Preparation from compounds containing silicon
- C01B32/977—Preparation from organic compounds containing silicon
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Health & Medical Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Inorganic Chemistry (AREA)
- Carbon And Carbon Compounds (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、レーザーによる炭化ケイ素（以下、ＳｉＣと
言う）微粒子の製造に関し、詳しくは、ガスブレークダ
ウンを利用したレーザーによるＳｉＣ微粒子の製造法に
関する。TECHNICAL FIELD The present invention relates to the production of silicon carbide (hereinafter referred to as SiC) fine particles by laser, and more specifically, a method of producing SiC fine particles by laser using gas breakdown. Regarding
（従来の技術） 一般に種々の材料となる物質は、原子の数が無限個の集
合体であり、その物質の大きさが極端に小さくなると、
特異な性質を示すようになる。物質の粒径が１μｍ（原
子数にして１０10個）以下のものは微粒子と呼ばれ、焼
結原料、触媒、生物工学等の種々の用途に用いられる新
素材として関心が持たれている。この結果、用いられる
微粒子に望ましい条件は、化学的純度が高いこと、球状
でありその粒径が小さいこと、粒径が均一であること等
である。このような微粒子に製造法としては、固相反応
法、液相反応法、気相反応法等があるが、上記の条件に
適合した微粒子の製造法としては気相反応法が最適であ
る。(Prior Art) In general, substances that are various materials are aggregates with an infinite number of atoms, and when the size of the substance becomes extremely small,
It shows unique properties. Particles having a particle diameter of 1 μm or less (10 10 in terms of the number of atoms) are called fine particles, and are attracting attention as new materials used for various purposes such as sintering raw materials, catalysts and biotechnology. As a result, desirable conditions for the fine particles used are that the chemical purity is high, that the particles are spherical and the particle size is small, and the particle size is uniform. As a method for producing such fine particles, there are a solid phase reaction method, a liquid phase reaction method, a gas phase reaction method and the like, but a gas phase reaction method is most suitable as a method for producing fine particles which meet the above conditions.
他方、レーザー技術に関する進歩は目覚ましく、広い波
長領域で強力な光を発振するレーザーが開発されてい
る。とりわけ、典型的な赤外レーザーである炭酸ガスレ
ーザーは、その高効率、高出力のため、種々の用途が考
えられている。例えば、パルス発振ＴＥＡ−ＣＯ２レー
ザーの赤外多光子解離による同位体分離や連続発振ＣＯ
２レーザーの熱反応による微粒子製造等が研究されてお
り、すでに、第３図に示すような気相反応法とレーザー
誘起反応とを組合わせた微粒子生成法（セラミックス：
１９（１９８４）、No.６、ｐ４８２）が報告されてい
る。これは、反応ガスをＣＯ２レーザーで加熱して、以
下に示す反応によって、Ｓｉ、ＳｉＣ、Ｓｉ３Ｎ４の超
微粒子を生成するものである。On the other hand, progress in laser technology has been remarkable, and lasers that emit strong light in a wide wavelength range have been developed. In particular, carbon dioxide gas laser, which is a typical infrared laser, has been considered for various applications because of its high efficiency and high output. For example, isotope separation by infrared multiphoton dissociation of a pulse oscillation TEA-CO 2 laser or continuous oscillation CO
The production of fine particles by the thermal reaction of two lasers has been studied, and a fine particle production method (ceramics: a combination of a gas phase reaction method and a laser-induced reaction as shown in FIG.
19 (1984), No. 6, p482). In this method, the reaction gas is heated by a CO 2 laser to generate ultrafine particles of Si, SiC, and Si 3 N 4 by the following reaction.
ＳｉＮ４（ｇ）→Ｓｉ（ｓ）＋２Ｈ２（ｇ） ２ＳｉＮ４（ｇ）＋Ｃ２Ｈ４（ｇ）→ ２ＳｉＣ（ｓ）＋６Ｈ２（ｇ） ３ＳｉＮ４（ｇ）＋４ＮＨ３（ｇ）→ Ｓｉ３Ｎ４（ｇ）＋１２Ｈ２（ｇ） （発明が解決しようとする課題） 本発明者等は、レーザー応用技術を研究する過程で、前
述のＣＯ２レーザーの熱反応法に代わって、気体の誘電
破壊（ガスブレークダウン）、すなわち、パルス発振レ
ーザーを気体に照射するとレーザー光の時間的、空間的
な高輝度のために生じる現象を利用して、微粒子を生成
することができることを見い出した。このブレークダウ
ンを利用すると、原料気体にレーザーを照射して種々の
反応を誘起させ粒径の非常に小さい固体生成物を製造す
ることができる。この方法の特長は次のようなものであ
る。(1)照射光の波長領域に吸収帯を有しない物質も原
料として用いることができる。(2)光の吸収効率がよ
い。(3)操作圧が高く、反応は連鎖的なので収量が多
い。(4)器壁からの不純物の混入がない。(5)常温の反応
容器で高融点物質が得られる。(6)粒径分布が狭い微粒
子が得られる。(7)反応装置が単純で容易に行うことが
できる。本発明は、上記のような特長を有するレーザー
によるブレークダウンを利用した高融点物質ＳｉＣの微
粒子を製造する方法を提供することを目的とする。SiN 4 (g) → Si (s) + 2H 2 (g) 2SiN 4 (g) + C 2 H 4 (g) → 2SiC (s) + 6H 2 (g) 3SiN 4 (g) + 4NH 3 (g) → Si 3 N 4 (g) + 12H 2 (g) (Problems to be Solved by the Invention) In the process of studying laser application technology, the present inventors have replaced the thermal reaction method of CO 2 laser described above with a gas dielectric. It has been found that fine particles can be generated by utilizing the phenomenon of destruction (gas breakdown), that is, when a pulsed laser beam is applied to a gas, due to the high temporal and spatial brightness of the laser beam. By utilizing this breakdown, it is possible to produce a solid product having a very small particle size by irradiating the raw material gas with a laser to induce various reactions. The features of this method are as follows. (1) A substance having no absorption band in the wavelength region of irradiation light can also be used as a raw material. (2) High light absorption efficiency. (3) The operating pressure is high and the reaction is chained, so the yield is high. (4) No impurities are mixed in from the vessel wall. (5) A high melting point substance can be obtained in a reaction vessel at room temperature. (6) Fine particles having a narrow particle size distribution can be obtained. (7) The reactor is simple and easy to carry out. It is an object of the present invention to provide a method for producing fine particles of a refractory substance SiC using the breakdown by a laser having the above-mentioned features.
（課題を解決するための手段） テトラメチルシラン（Ｓｉ（ＣＨ３）４）と水素
（Ｈ２）とを含む混合ガスにパルス発振ＣＯ２レーザー
光を照射して、ガスブレークダウン現象により炭化ケイ
素（ＳｉＣ）の微粒子を生成することを特徴とする。(Means for Solving the Problem) A mixed gas containing tetramethylsilane (Si (CH 3 ) 4 ) and hydrogen (H 2 ) is irradiated with pulsed CO 2 laser light, and silicon carbide is generated by a gas breakdown phenomenon. It is characterized by producing fine particles of (SiC).
（作 用） 以下本発明を詳しく説明する。(Operation) The present invention will be described in detail below.
粒径の揃った特性の良い微粒子の製法としては、気体原
料を用いる気相法が適しているが、ＳｉＣの気体の原料
として、テトラメチルシラン（Ｓｉ（ＣＨ３）４）およ
び水素の混合ガスを用いる。この原料にＣＯ２レーザー
のパルス光を照射すると、レーザー光の単位断面積当た
りのエネルギー（フルエンス）が小さい場合には、レー
ザー光のエネルギーは混合ガスにほとんど吸収されない
が、ある程度以上の強さのレーザー光の場合、原料ガス
内でブレークダウンが起こって、照射されたレーザーエ
ネルギーのほとんどが吸収される。これは原料ガス分子
の光エネルギーによるイオン化およびそれによって生じ
た電子の光エネルギー吸収に続くイオン化の繰り返しに
よって次ぎの反応が引き起こされる。A gas phase method using a gas raw material is suitable as a method for producing fine particles having a uniform particle size, but a mixed gas of tetramethylsilane (Si (CH 3 ) 4 ) and hydrogen is used as a raw material for the SiC gas. To use. When this raw material is irradiated with pulsed light of a CO 2 laser, when the energy (fluence) per unit cross-sectional area of the laser light is small, the energy of the laser light is hardly absorbed by the mixed gas, but with a certain intensity or more. In the case of laser light, a breakdown occurs in the raw material gas, and most of the irradiated laser energy is absorbed. This is because the following reaction is caused by the ionization of the source gas molecules by the light energy and the absorption of the resulting light energy by the electrons, followed by the ionization.
Ｓｉ（ＣＨ３）４＋Ｈ２→ ＳｉＣ＋Ｃ２Ｈ６＋Ｃ２Ｈ４＋Ｃ２Ｈ２＋ＣＨ４＋Ｈ２
…… この場合、照射に使用するレーザーの波長は、原料ガス
の吸収波長に関係なく、できるだけパルスエネルギーの
強い発振波長が良い。上記の反応によって得られるＳｉ
Ｃは気相で均一核生成と成長によって生成した粒子状の
もので、原理的に球状で粒径分布が狭く、粒径が１μｍ
以下の微粒子であり、生成条件の制御により得られる微
粒子の特性を変えることが可能である。Si (CH 3 ) 4 + H 2 → SiC + C 2 H 6 + C 2 H 4 + C 2 H 2 + CH 4 + H 2
...... In this case, the wavelength of the laser used for irradiation should be the oscillation wavelength with the strongest pulse energy, regardless of the absorption wavelength of the source gas. Si obtained by the above reaction
C is in the gas phase and is in the form of particles produced by uniform nucleation and growth. In principle, it has a spherical shape with a narrow particle size distribution and a particle size of 1 μm.
The following fine particles can change the characteristics of the fine particles obtained by controlling the production conditions.
実際の微粒子の製造には、回分式又は連続流通式の照射
セルを使用し、生成した微粒子はフィルターやその他の
補集装置で補集することができる。A batch type or continuous flow type irradiation cell is used for the actual production of the fine particles, and the produced fine particles can be collected by a filter or other collecting device.
（発明の効果） このように、本発明によって得られたＳｉＣ微粒子は、
球状でしかも均一であり、また、高硬度、高融点セラミ
ックスとして種々の有用な素材に利用できる。現在、Ｓ
ｉＣ微粒子は粉砕法によって製造されているが、硬度が
大であるため能率が悪く、球状の微粒子が得られにく
い。また、粉砕機からの不純物の混入も避けられない。
本法では前述のように、生成原理も簡単なものであり、
現行法よりも著しく有利である。更に、ＳｉＣ微粒子
は、素材等への用途が具体的であり、ほかのセラミック
スに比べ高密度の焼結素材ができるので有望である。(Effect of the invention) As described above, the SiC fine particles obtained by the present invention are
It is spherical and uniform, and can be used as various useful materials as high hardness and high melting point ceramics. Currently S
Although the iC fine particles are manufactured by a pulverization method, the hardness is high, so that the efficiency is poor and it is difficult to obtain spherical fine particles. In addition, mixing of impurities from the crusher is inevitable.
In this method, as described above, the generation principle is also simple,
Significant advantages over current legislation. Furthermore, the SiC fine particles are particularly promising because they can be used as a material and have a high-density sintered material as compared with other ceramics.
（実施例） 本発明に使用した装置の概略を第１図に示す、適切な波
数のＣＯ２レーザー１１のパルス光１２をＢａＦ２レン
ズ１３で集光し、照射反応容器１４内のＳｉ（ＣＨ３）
４とＨ２の混合気体である試料気体１５に照射する。な
お、図中１６は絞り、１７はＫＢｒ窓板、１８は補集容
器をそれぞれ示す。照射後、残留および生成ガスを排気
除去し、不活性ガスで容器内を充たした後、生成した微
粒子を補集容器から取り出す。(Example) An outline of an apparatus used in the present invention is shown in FIG. 1, pulsed light 12 of a CO 2 laser 11 having an appropriate wave number is condensed by a BaF 2 lens 13, and Si (CH 2) in an irradiation reaction container 14 is condensed. 3 )
The sample gas 15 which is a mixed gas of 4 and H 2 is irradiated. In the figure, 16 is a diaphragm, 17 is a KBr window plate, and 18 is a collection container. After the irradiation, the residual gas and the generated gas are exhausted and removed, the inside of the container is filled with an inert gas, and then the generated fine particles are taken out from the collection container.
３０TorrのＳｉ（ＣＨ３）４と１５０TorrのＨ２の混合
ガスにＣＯ２レーザーの９．６μｍ帯のＰ（２４）、す
なわち１０４３cm-1のパルス光を照射した、この時のパ
ルスエネルギーは約０．４Ｊ／pulse、使用したレンズ
の焦点距離は７．５cmである。A mixed gas of 30 Torr Si (CH 3 ) 4 and 150 Torr H 2 was irradiated with P (24) in the 9.6 μm band of a CO 2 laser, that is, 1043 cm −1 pulsed light, and the pulse energy at this time was about 0. The focal length of the used lens is 7.5 cm.
生成した微粒子のＸ線回折図形を第２図に示す。Ｓｉ
Ｃ、Ｓｉ、Ｃの既知のデータ値と測定したＸ線回折図形
を対比し、該図形の解析から得られる面定数と元素分析
の結果から、生成微粒子はＳｉＣであることをを確認し
た。更に、本法によって得られたＳｉＣは平均粒径が
０．１〜０．５μｍの比較的均一な分布を示し、しかも
球状の微粒子であることが走査型電子顕微鏡写真によっ
て確認された。The X-ray diffraction pattern of the produced fine particles is shown in FIG. Si
It was confirmed that the produced fine particles were SiC from the results of the surface constant and elemental analysis obtained by analyzing the X-ray diffraction pattern obtained by comparing the known data values of C, Si, and C with the measured X-ray diffraction pattern. Further, it was confirmed by scanning electron microscope photographs that the SiC obtained by this method showed a relatively uniform distribution with an average particle size of 0.1 to 0.5 μm and was spherical fine particles.
第１図は、本発明の実施例に用いた装置の概略図、 第２図は、本発明の実施例で得られたＳｉＣ微粒子のＸ
線回折図形を示す。 第３図は、従来の連続発振ＣＯ２レーザーを用いた気相
法による微粒子生成法の反応容器の概略図。 （符号の説明） １１……ＣＯ２レーザー、 １２……レーザー光、 １３……ＢａＦ２レンズ、 １４……照射反応容器、 １５……試料気体、 １６……絞り、 １７……ＫＢｒ窓板、 １８……補集容器、 １９……ＫＢｒ窓板、 ２０……コック。FIG. 1 is a schematic diagram of an apparatus used in the examples of the present invention, and FIG. 2 is an X of the SiC fine particles obtained in the examples of the present invention.
A line diffraction pattern is shown. FIG. 3 is a schematic view of a reaction container of a particle generation method by a gas phase method using a conventional continuous wave CO 2 laser. (Explanation of symbols) 11 ... CO 2 laser, 12 ... laser light, 13 ... BaF 2 lens, 14 ... Irradiation reaction container, 15 ... Sample gas, 16 ... Aperture, 17 ... KBr window plate, 18 ... Collection container, 19 ... KBr window plate, 20 ... Cock.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 西澤 博 東京都小平市小川東町2602―24 (72)発明者 石井 忠浩 東京都日野市平山１―６―５ ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Hiroshi Nishizawa 2602-24 Ogawahigashi-cho, Kodaira-shi, Tokyo (72) Inventor Tadahiro Ishii 1-6-5 Hirayama, Hino-shi, Tokyo
Claims (1)
と水素（Ｈ２）とを含む混合ガスにレーザー光を照射し
て炭化ケイ素（ＳｉＣ）の微粒子を製造する方法。1. Tetramethylsilane (Si (CH 3 ) 4 )
A method for producing fine particles of silicon carbide (SiC) by irradiating a mixed gas containing hydrogen and hydrogen (H 2 ) with laser light.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63079227A JPH0621023B2 (en) | 1988-03-31 | 1988-03-31 | Method for producing fine particles of silicon carbide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63079227A JPH0621023B2 (en) | 1988-03-31 | 1988-03-31 | Method for producing fine particles of silicon carbide |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH01252515A JPH01252515A (en) | 1989-10-09 |
| JPH0621023B2 true JPH0621023B2 (en) | 1994-03-23 |
Family
ID=13684017
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63079227A Expired - Lifetime JPH0621023B2 (en) | 1988-03-31 | 1988-03-31 | Method for producing fine particles of silicon carbide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0621023B2 (en) |
-
1988
- 1988-03-31 JP JP63079227A patent/JPH0621023B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH01252515A (en) | 1989-10-09 |
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