JP2784060B2 - Manufacturing method of high purity silicon nitride powder - Google Patents
Manufacturing method of high purity silicon nitride powderInfo
- Publication number
- JP2784060B2 JP2784060B2 JP1243145A JP24314589A JP2784060B2 JP 2784060 B2 JP2784060 B2 JP 2784060B2 JP 1243145 A JP1243145 A JP 1243145A JP 24314589 A JP24314589 A JP 24314589A JP 2784060 B2 JP2784060 B2 JP 2784060B2
- Authority
- JP
- Japan
- Prior art keywords
- silicon nitride
- gas
- nitride powder
- laser beam
- amorphous
- 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 - Fee Related
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/06—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron
- C01B21/068—Binary compounds of nitrogen with metals, with silicon, or with boron, or with carbon, i.e. nitrides; Compounds of nitrogen with more than one metal, silicon or boron with silicon
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、窒化ケイ素粉末の製法、特に、粒子径0.5
〜３μｍの等軸的粒状粒子からなる高純度窒化ケイ素粉
末の製法に関する。このような窒化ケイ素は、高温構造
材料としてガスタービン部材、ノズル、軸受等に利用さ
れるものである。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing silicon nitride powder,
The present invention relates to a method for producing a high-purity silicon nitride powder composed of equiaxed granular particles of about 3 μm. Such silicon nitride is used as a high-temperature structural material for gas turbine members, nozzles, bearings, and the like.
従来、化学的に高純度で、α型窒化ケイ素の含有率が
高く、粒子径が微細でかつその形状が等軸的粒状である
窒化ケイ素粉末は、もっぱら、（水素化）ハロゲン化ケ
イ素とアンモニアとを反応させてシリコンイミドもしく
は非晶質の反応生成物（非晶質窒化ケイ素とも言われて
いる。以下、そのように言うこともある。）を合成し、
それを窒素あるいはアンモニア雰囲気下で高温加熱して
結晶化する方法により製造されている。（例えば、特開
昭59−21506号公報、特開昭59−21507号公報、窯業協会
誌80〔３〕1972P114〜120等）。Conventionally, silicon nitride powder of high chemical purity, high content of α-type silicon nitride, fine particle diameter and equiaxed granular shape is mainly composed of (hydrogenated) silicon halide and ammonia. To synthesize silicon imide or an amorphous reaction product (also referred to as amorphous silicon nitride; hereinafter, this may be referred to as such).
It is manufactured by a method of crystallization by heating it at a high temperature in a nitrogen or ammonia atmosphere. (For example, JP-A-59-21506, JP-A-59-21507, Journal of the Ceramic Industry Association 80 [3] 1972P114-120, etc.).
しかしながら、この方法では、シリコンイミドもしく
は非晶質の反応生成物を一度系外に取出し、その後、等
軸状にせしめるべく操作、例えば種添加に伴う混合や摩
砕等を行なう必要があるため、工程が複雑になったり一
部大気暴露により窒化ケイ素粉末中の酸素や金属不純物
が増加する欠点があった。However, in this method, it is necessary to take out the silicon imide or the amorphous reaction product once out of the system, and then perform operations such as mixing and milling accompanying seed addition to make it equiaxed. There were drawbacks that the process became complicated and that oxygen and metal impurities in the silicon nitride powder increased due to partial exposure to air.
本発明者らは、これらの欠点を解決することを目的に
種々検討した結果、ハロゲン化ケイ素とアンモニアとを
反応させて得られた非晶質の反応生成物は、電子顕微鏡
観察によれば500〜1,000Åの球状の一次粒子のかなりの
強固な凝集粒子になっており、理由はよくわからない
が、それが等軸的粒状窒化ケイ素を得るための重要な要
因になっていることをつきとめた。そこでそれを系外に
取出すことなしに何んらかの操作で解きぼぐし、そして
そこに何んらかの窒化ケイ素の種（核）を導入すること
ができないかという観点にたってさらに検討を進めたと
ころ、その手段としてCO2ガスレーザビームを用にれば
よいことを見い出し、本発明に到達したものである。The present inventors have conducted various studies with the aim of solving these drawbacks.As a result, an amorphous reaction product obtained by reacting silicon halide with ammonia was found to be 500 It is a fairly strong agglomerated particle of spherical primary particles of ~ 1,000 mm2, and for unknown reasons, it was found that it is an important factor for obtaining equiaxed granular silicon nitride. Therefore, it is dismantled by some operation without taking it out of the system, and further investigation is made from the viewpoint of whether some kind of silicon nitride seed (nucleus) can be introduced there. As a result, they have found that a CO 2 gas laser beam can be used as the means, and have reached the present invention.
CO2ガスレーザビームを用いて窒化ケイ素微粒子を合
成する方法は公知である（例えば、特開昭60−51539号
公報）が、この方法は、CO2ガスレーザビームの波長10.
6μｍと同波長の赤外吸収帯を持つSiH4による超微粉い
主眼を置いたものであり、本発明のように非晶質窒化ケ
イ素粉末の凝集・架橋を解きほぐすことにより、窒化ケ
イ素の種（核）を導入し等軸状の窒化ケイ素粉末を合成
するという製法とは異なるものである。Method for synthesizing silicon nitride particles with CO 2 gas laser beam is known (e.g., JP 60-51539 JP) is the method, CO 2 gas laser beam wavelength 10.
The main focus is on ultra-fine powder of SiH 4 having an infrared absorption band of the same wavelength as 6 μm, and the seeds of silicon nitride ( This is different from the production method of introducing a nucleus) to synthesize an equiaxial silicon nitride powder.
すなわち、本発明は、ハロゲン化ケイ素とアンモニア
とを、CO2ガスレーザビーム照射により反応させて、非
晶質の反応生成物を得、それを非酸化性雰囲気下、温度
1,400〜1,600℃で0.5〜10時間加熱することを特徴とす
る等軸的粒状粒子からなる高純度窒化ケイ素粉末の製法
である。That is, the present invention provides a reaction between silicon halide and ammonia by irradiation of a CO 2 gas laser beam to obtain an amorphous reaction product, which is heated in a non-oxidizing atmosphere at a temperature
This is a method for producing high-purity silicon nitride powder comprising equiaxed granular particles, characterized by heating at 1,400 to 1,600 ° C. for 0.5 to 10 hours.
以下、更に詳しく本発明について説明する。 Hereinafter, the present invention will be described in more detail.
本発明は、先ず、第１段階として、ハロゲン化ケイ素
とアンモニアとを気相反応させるに際し、CO2ガスレー
ザビームを照射して、窒化ケイ素の種（核）を一部生じ
せしめた非晶質の反応生成物粉末（非晶質窒化ケイ素粉
末）を合成する。一般に、レーザビームで粉末を合成し
ようとする場合、レーザの固有波長に近い赤外吸収帯を
持つガスが必要であるが、本発明に用いたハロゲン化ケ
イ素にはそれがない。しかし、NH3の赤外吸収帯が、10.
5μｍであることより（化学便覧（改訂３版）、日本化
学会編、II−609（1984））、その赤外吸収帯を利用で
きないか種々検討した結果、NH3流量を増すに従ってレ
ーザビームの照射特有の反応炎が生じることを見い出す
と共に、反応炎が生じないNH3量においてもそこにハロ
ゲン化ケイ素例えばSiCl4ガスを通過させて得られた非
晶質の反応生成物（非晶質窒化ケイ素）粉末を加熱結晶
化させると窒化ケイ素が等軸的粒状粒子になることを確
認した。つまり、超微粉が生成するような反応炎でなく
ても使用するレーザビーム固有波長と同領域の赤外吸収
帯を持つガス存在下で気相反応を行なえば、前述した凝
集粒子が解放され、更に、微粒の窒化ケイ素の種（核）
が導入された形となることを見い出したものである。According to the present invention, first, as a first step, when a silicon halide and ammonia are subjected to a gas phase reaction, a CO 2 gas laser beam is irradiated to partially generate a silicon nitride seed (nucleus). A reaction product powder (amorphous silicon nitride powder) is synthesized. Generally, when a powder is to be synthesized by a laser beam, a gas having an infrared absorption band close to the intrinsic wavelength of the laser is required, but the silicon halide used in the present invention does not have such a gas. However, the infrared absorption band of NH 3 is 10.
Than it is 5μm (Chemical Handbook (third revised edition), edited by the Chemical Society of Japan, II-609 (1984)) , that do not use the infrared absorption band a result of various studies, of the laser beam in accordance with the increase of the flow rate of NH 3 together we found that irradiation specific reaction flame occurs, an amorphous reaction product of the reaction flame obtained therein passed through a silicon halide e.g. SiCl 4 gas is also in the amount of NH 3 does not occur (amorphous nitride It was confirmed that silicon nitride powder became equiaxed granular particles when heat-crystallized. In other words, if the gas phase reaction is performed in the presence of a gas having an infrared absorption band in the same region as the laser beam specific wavelength to be used even if it is not a reaction flame that generates ultrafine powder, the above-described aggregated particles are released, In addition, fine silicon nitride seeds (nuclei)
Has been found to have been introduced.
ここで、非晶質の反応生成物（非晶質窒化ケイ素）と
は、前掲した窯業協会誌にも示されているように、Ｘ線
回折図において、２θ（CuKα）が20゜〜40゜にかけて
ブロードな弱い回折が認められるだけであって、α−Si
3N4又はβ−Si3N4の特性回折が認められないものをい
う。Here, the amorphous reaction product (amorphous silicon nitride) is, as shown in the above-mentioned Journal of the Ceramics Association, 2θ (CuKα) of 20 ° to 40 ° in the X-ray diffraction diagram. Only weak broad diffraction is observed toward
3 N 4 or refers to those properties diffraction beta-Si 3 N 4 is not observed.
以上のことより、本発明に用いるNH3/ハロゲン化ケイ
素の反応ガスモル比は、温度により異なるが、下記反応
式のモル比並びに経済的事由を加味して30未満程度で十
分と考えられる。From the above, the reaction gas molar ratio of NH 3 / silicon halide used in the present invention differs depending on the temperature, but it is considered that a molar ratio of less than about 30 is sufficient considering the molar ratio of the following reaction formula and economic reasons.
SiX4＋6NH3＝Si（NH）２＋4NH4X ただし、Ｘはハロゲン また、その下限値については特別な制限はないが、１
以下になるとCO2ガスレーザビームの照射効果が小さく
なり、窒化ケイ素の粒径が大きくなったり一部針状晶が
生じて好ましくなくなる。SiX 4 + 6NH 3 = Si (NH) 2 + 4NH 4 X where X is a halogen.
Below this, the irradiation effect of the CO 2 gas laser beam decreases, and the particle size of silicon nitride increases, or some needle crystals are formed, which is not preferable.
本発明では、ハロゲン化ケイ素とCO2ガスレーザビー
ムとには何んらの結びつきがないので、本発明で使用さ
れるハロゲン化ケイ素としては、SiCl4、SiBr4などの他
にSiH2Cl2、SiH3Cl、SiH2Br2、SiH3Brをも使用できる。
これらは単独又は混合して用いられる。In the present invention, since there is no link between what Nra in the silicon halide and CO 2 gas laser beam, as the silicon halide to be used in the present invention, SiH 2 Cl 2 to other such SiCl 4, SiBr 4, SiH 3 Cl, SiH 2 Br 2 and SiH 3 Br can also be used.
These are used alone or in combination.
反応温度は1,000℃以下であるが好ましくは150℃以下
である。1,000℃を超える温度ではCO2ガスレーザビーム
10.6μｍ波長と同領域の赤外吸収帯を持つアンモニアガ
スの分解が生じる。The reaction temperature is 1,000 ° C. or lower, preferably 150 ° C. or lower. CO 2 gas laser beam at temperatures over 1,000 ° C
Decomposition of ammonia gas having an infrared absorption band in the same region as the wavelength of 10.6 μm occurs.
CO2ガスレーザビームは原料ガスの流れの方向と交差
する方向好ましくは直交する方向から照射する。レーザ
用の窓材としてはZn−Se等の材料が使用される。CO2ガ
スレーザビームの強度としては1cm2当り100ワット以上
あれば十分であり、その時のガス流速はレーザ照射部で
の滞留時間が0.01秒以上になるように調整する。反応器
としては温度にもよるが、SUS、石英、炭化ケイ素、黒
鉛等の材質が使用される。The CO 2 gas laser beam is emitted from a direction intersecting, preferably orthogonal to, the direction of the flow of the source gas. A material such as Zn—Se is used as the window material for the laser. It is sufficient for the intensity of the CO 2 gas laser beam to be 100 watts or more per 1 cm 2 , and the gas flow rate at that time is adjusted so that the residence time in the laser irradiation section becomes 0.01 seconds or more. Depending on the temperature, a material such as SUS, quartz, silicon carbide, or graphite is used as the reactor.
次に、第２工程の加熱結晶化について説明する。 Next, the heat crystallization in the second step will be described.
CO2ガスレーザビームを照射して得られた非晶質の反
応生成物（非晶質窒化ケイ素）粉末は更に高温加熱し、
副生したNH4Clを除去し結晶化される。結晶化のための
加熱はN2、H2、Ar、He、NH3等の非酸化性雰囲気下、温
度1,400〜1,600℃で0.5〜10時間行う。加熱温度が1,400
℃未満では結晶化が十分に進まず、また、1,600℃を超
えるとβ型窒化ケイ素が生成し高強度焼結体の原料とし
ては適当でなくなる。加熱時間は0.5時間以上でないと
脱ハロゲンが十分でなく、また、10時間を越えると粒成
長がおこり、得られる粉末粒子が３μｍを越え焼結性が
低下する。加熱結晶化の方法には特に制限はなく、特開
平１−100005号公報に示す連続炉でも良く、さらには、
るつぼ炉のようなバッチ式でも十分に本発明の目的は達
せられる。The amorphous reaction product (amorphous silicon nitride) powder obtained by irradiating a CO 2 gas laser beam is further heated to a high temperature,
The by-product NH 4 Cl is removed and crystallized. Heating for crystallization N 2, H 2, Ar, He, non-oxidizing atmosphere such as NH 3, carried out for 0.5 to 10 hours at a temperature 1,400 to 1,600 ° C.. Heating temperature is 1,400
If the temperature is lower than ℃, crystallization does not proceed sufficiently, and if it exceeds 1600 ° C, β-type silicon nitride is generated and is not suitable as a raw material for a high-strength sintered body. If the heating time is not longer than 0.5 hours, dehalogenation will not be sufficient, and if it exceeds 10 hours, grain growth will occur, and the resulting powder particles will exceed 3 μm, deteriorating sinterability. The method of heat crystallization is not particularly limited, and may be a continuous furnace described in JP-A-1-100005.
The object of the present invention can be sufficiently achieved even in a batch type such as a crucible furnace.
本発明の方法に従うとき、得られる窒化ケイ素粉末は
酸素量1.5％以下、Ca、Feなどの金属不純物量0.05％以
下と非常に高純度で、α型窒化ケイ素の含有率もα分率
で90％以上と高く、しかもその粒子形状は等軸的粒状
で、その大きさも0.5〜３μｍと細かいもので、焼結体
原料として非常にすぐれたものである。なお、窒化ケイ
素粉末の等軸的粒状粒子の大きさは、NH3/ハロゲン化ケ
イ素の反応ガスモル比、NH3量、CO2ガスレーザビームの
強度がそれぞれ大であればある程小さくなる。According to the method of the present invention, the obtained silicon nitride powder has a very high purity of not more than 1.5% of oxygen and not more than 0.05% of metal impurities such as Ca and Fe, and the content of α-type silicon nitride is 90% by α fraction. % Or more, and its particle shape is equiaxed granular, its size is as fine as 0.5 to 3 μm, and it is very excellent as a raw material for a sintered body. The size of the equiaxial granular particles of the silicon nitride powder becomes smaller as the reaction gas molar ratio of NH 3 / silicon halide, the amount of NH 3 , and the intensity of the CO 2 gas laser beam increase.
以下、実施例と比較例をあげてさらに具体的に説明す
る。Hereinafter, examples and comparative examples will be described more specifically.
実施例１〜６、比較例１〜５ 窒素ガスをキャリヤーとして、市販のSiCl4及びアン
モニアガス（99.99％）を用い、第１表に示す非晶質窒
化ケイ素粉末を合成した。CO2ガスレーザビーム導入方
法については、レーザ光入口及び出口に相当する部分に
Zn−Se窓を備えた石英反応管（40φ×240L）を用いた。
また、CO2ガス発振器は600Wのスペクトロフィジックス
社製の装置を用い、Zn−Seレンズとフィルターを通して
1cm2程度に集光し照射した。Examples 1 to 6 and Comparative Examples 1 to 5 Using nitrogen gas as a carrier, commercially available SiCl 4 and ammonia gas (99.99%) were used to synthesize amorphous silicon nitride powders shown in Table 1. Regarding the CO 2 gas laser beam introduction method, the parts corresponding to the laser light entrance and exit
A quartz reaction tube (40 φ × 240 L ) equipped with a Zn—Se window was used.
The CO 2 gas oscillator uses a 600 W spectrophysics device and passes through a Zn-Se lens and filter.
The light was condensed to about 1 cm 2 and irradiated.
得られた非晶質の反応生成物（非晶質窒化ケイ素）粉
末は、大気に十分注意し、グローボックス内で黒鉛製ル
ツボに充填しビニール袋で覆い速かに電気炉に入れ、第
１表に示す条件で加熱結晶化した。The obtained amorphous reaction product (amorphous silicon nitride) powder was carefully watched in the air, filled in a graphite crucible in a glow box, covered with a plastic bag, and quickly placed in an electric furnace. Heat crystallization was performed under the conditions shown in the table.
得られた窒化ケイ素粉末について、酸素、金属不純
物、α分率、粒子形態及び粒子径の測定並びにSEM写真
観察を実施した。第１図及び第２図には、それぞれ実施
例１及び比較例１によって得られた窒化ケイ素粉末の粒
子構造を示す走査型電子顕微鏡写真を示した。With respect to the obtained silicon nitride powder, measurement of oxygen, metal impurities, α fraction, particle morphology and particle diameter, and SEM photograph observation were performed. FIGS. 1 and 2 show scanning electron micrographs showing the particle structures of the silicon nitride powders obtained in Example 1 and Comparative Example 1, respectively.
（１）．酸素（重量％） :LECO社製TC−136型O/N同時
分析計による。(1). Oxygen (% by weight): Using a TC-136 O / N simultaneous analyzer manufactured by LECO.
（２）．金属不純物（ppm）:JIS−Ｇ−1322に準拠し
た。表にはFe、Al、Ca、Mgの合計を示した。(2). Metal impurities (ppm): Based on JIS-G-1322. The table shows the total of Fe, Al, Ca, and Mg.
（３）．α分率（％） ：理学電機社製のガイガーフ
ラックスRAD−II B型のＸ線回折による。(3). α fraction (%): By X-ray diffraction of Geiger flux RAD-IIB type manufactured by Rigaku Corporation.
（４）．粒子形態及び粒子径：日本電子（株）製走査型
電子顕微鏡による。(4). Particle morphology and particle size: by a scanning electron microscope manufactured by JEOL Ltd.
〔発明の効果〕 本発明によれば、ハロゲン化ケイ素とNH3ガスを原料
として合成された非晶質の反応生成物（非晶質窒化ケイ
素）粉末に、種添加や摩砕等の操作を加えることなく簡
単に、酸素や金属不純物の含有量の小さい高純度な等軸
的粒状粒子を製造することができる。 [Effects of the Invention] According to the present invention, operations such as seed addition and grinding are performed on an amorphous reaction product (amorphous silicon nitride) powder synthesized using silicon halide and NH 3 gas as raw materials. It is possible to easily produce high-purity equiaxed granular particles having a small content of oxygen and metal impurities without addition.
第１図及び第２図は、それぞれ実施例１及び比較例１で
得られた窒化ケイ素粉末の粒子構造を示す倍率5,000倍
及び10,000倍のSEM写真である。FIGS. 1 and 2 are SEM photographs at 5,000 and 10,000 magnifications showing the particle structure of the silicon nitride powder obtained in Example 1 and Comparative Example 1, respectively.
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.6，ＤＢ名) C01B 21/068──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. 6 , DB name) C01B 21/068
Claims (1)
ガスレーザビーム照射により反応させて、非晶質の反応
生成物を得、それを非酸化性雰囲気下、温度1,400〜1,6
00℃で0.5〜10時間加熱することを特徴とする等軸的粒
状粒子からなる高純度窒化ケイ素粉末の製法。1. A method according to claim 1, wherein the silicon halide and ammonia are mixed with CO 2
The reaction was performed by irradiation with a gas laser beam to obtain an amorphous reaction product, which was then heated at a temperature of 1,400 to 1,6 in a non-oxidizing atmosphere.
A method for producing high-purity silicon nitride powder comprising equiaxed granular particles, characterized by heating at 00 ° C. for 0.5 to 10 hours.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1243145A JP2784060B2 (en) | 1989-09-19 | 1989-09-19 | Manufacturing method of high purity silicon nitride powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1243145A JP2784060B2 (en) | 1989-09-19 | 1989-09-19 | Manufacturing method of high purity silicon nitride powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH03109208A JPH03109208A (en) | 1991-05-09 |
| JP2784060B2 true JP2784060B2 (en) | 1998-08-06 |
Family
ID=17099459
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1243145A Expired - Fee Related JP2784060B2 (en) | 1989-09-19 | 1989-09-19 | Manufacturing method of high purity silicon nitride powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2784060B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115432677B (en) * | 2021-06-04 | 2024-03-22 | 中国科学院过程工程研究所 | System and method for preparing high-quality silicon nitride powder by impinging stream coupling fluidized bed |
-
1989
- 1989-09-19 JP JP1243145A patent/JP2784060B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH03109208A (en) | 1991-05-09 |
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