JPS5973412A - Preparation of powder of silicone nitride - Google Patents

Abstract

PURPOSE:To enable stable preparation of fine powder of extremely high-purity Si3N4 by reacting a silicon halide or a silicon hydride halide with ammonia in a gaseous phase to give a reaction product, heating it in an ammonia-containing gas and successively in an inert gas at high temperature. CONSTITUTION:A silicon halide such as SiCl4, SiBr4, etc. or a silicon hydride halide such as SiHCl2, SiHBr2, etc. is reacted with ammonia at 600-1,500 deg.C in a gaseous phase, The reaction product obtained by this reaction is heated in an ammonia-containing gas consisting of >=20vol% ammonia and the rest of N2 or Ar at 1,400 deg.C for 50hr-10min. It is successively heated in an inert gas such as N2 or Ar, etc. at 1,000-1,600 deg.C for 30hr-10min, to give fine powder of high- purity amorphous or alpha crystal Si3N4 containing <=0.5wt% halogen content, <=3wt% oxygen content and <=20wt% needle-like substance.

Description

【発明の詳細な説明】 この発明は窒化けい素粉体Ｓ〜の製造方泄す・悶し、特
にハロゲンおよび酸素の含有量を有利に少くすることに
関する１Ｍ発成果を提案しようとするものである。DETAILED DESCRIPTION OF THE INVENTION The present invention seeks to propose a method for producing silicon nitride powder S, in particular an advantageous reduction in the content of halogen and oxygen. be.

窒化けい素は優れた耐熱性、耐食性などに関して有用で
あり、種々の用途に用いられている。近年特に注目され
ているのはガス・タービンなどの高温材料の使途への適
合であり、その原料としての窒化けい素粉体も、高純度
でかつ微細な粉末の要請は、殊のほか強くのぞまれるに
至った。Silicon nitride is useful for its excellent heat resistance and corrosion resistance, and is used for various purposes. In recent years, the application of high-temperature materials such as gas turbines has received particular attention, and the demand for high-purity and fine silicon nitride powder as a raw material is especially strong. It has come to be.

従来、窒化けい素粉体の製造方法としては１）　　金属
シリコン粉末を直接窒化する方法８ン　シリカ粉末を黒
鉛粉末で還元し窒化する方法および ８）ハロゲン化けい素とアンモニアとを反応させる方法 などがあり、特に最後に掲げた方法は、金属不純物の少
ない窒化けい素粉体を製造する方法として優れている。Conventionally, methods for producing silicon nitride powder include 1) a method of directly nitriding metal silicon powder, a method of reducing silica powder with graphite powder and nitriding it, and 8) a method of reacting silicon halide with ammonia. In particular, the last method is excellent as a method for producing silicon nitride powder with low metal impurities.

そしてこの方法はざらに（イン室温付近様るいは低温で
反応させる方法と、（ロ）高温で反応、坊せる方法とに
大別される。This method is roughly divided into (2) a method in which the reaction is carried out at around room temperature or at a low temperature, and (2) a method in which the reaction is carried out at a high temperature.

低温性（イ）による反応生成物は、シ刃コンイミド５ｉ
（ＮＨ）Ｂおよびこれのアンモニア付加物で示される゛
含窒素シラン化合物であり、窒素あるいはアンモニア雰
囲気中での熱処理によって容易に７１０ゲン含有ｈ１の
少ない窒化けい素粉体な得ることができる点で有利な反
面、反応時の副生物として多量のハロゲン化アンモニウ
ムが生成し、これを熱処理して除去する必要があるため
、炉の容積効率が大きく低下し、また炉低温部にハロゲ
ン化アンモニウムが再析出して炉の閉塞をもたらす欠点
がある。The reaction product due to low temperature property (a) is Shiblade conimide 5i
It is a nitrogen-containing silane compound represented by (NH)B and its ammonia adduct, and it can be easily obtained as a silicon nitride powder with a low h1 content of 710 by heat treatment in a nitrogen or ammonia atmosphere. Although this is advantageous, a large amount of ammonium halide is produced as a by-product during the reaction, which must be removed by heat treatment, which greatly reduces the volumetric efficiency of the furnace, and also prevents ammonium halide from being recycled into the low-temperature section of the furnace. It has the disadvantage of depositing and clogging the furnace.

一方、高温法（ロ）では副生物としてガス状の塩化水素
が生成し、ハロゲン化アンモニウムによる弊簀は生じな
いか少くとも著しく軽減させること力τでき、しかもか
かる反応生成物は（イ）の場合と同様に熱処理して窒化
けい素粉体とすることができる０この際熱処理の雰囲気
としては窒素および／またはアンモニア中で行なうこと
は公知であるシタ低温法（イ）で得られる含窒素シラン
化合物と異なり、反応生成物中に直接結合したノ１０ゲ
ンが存在する。On the other hand, in the high-temperature method (b), gaseous hydrogen chloride is produced as a by-product, and the adverse effects of ammonium halides do not occur or at least can be significantly reduced. Nitrogen-containing silane obtained by the low-temperature method (a), which is known to be heat-treated in a nitrogen and/or ammonia atmosphere, can be made into silicon nitride powder by heat treatment in the same manner as in the case. Unlike the chemical compound, there is a directly bound compound in the reaction product.

−そのため窒素中の熱処理ではこの／％ロゲン番ま除去
できず焼結性に悪影響を及ぼし、またこのｉｔ力）岸晶
化させて、α−窒化けい素粉体とすること力（巾難であ
り、さらに／１０ゲンを除こうとしてより高温および／
または長時間にわたる熱処理を行な、うと窒化けい素粉
体はβ晶化してしまし）、焼結体原料として適さなくな
る。- Therefore, heat treatment in nitrogen cannot remove this /% rogen number, which has a negative effect on sinterability, and it is difficult to crystallize it to form α-silicon nitride powder. Yes, and/or higher temperature and/or
Otherwise, the silicon nitride powder becomes β crystallized due to prolonged heat treatment), making it unsuitable as a raw material for a sintered body.

さればといってアンモニア中で熱処理を行なう、ＩＩ＋
　、ハロゲンは除去できるにしても、アンモニアにより
アルミナやムライト質などの炉材が侵食されて、炉材寿
命を低下させ、また炉材からの不純物汚染を受ける原因
になり易く、さらに窒化はし１素粉体中の＾ψ素含有量
も多くなって、焼結体の高温特性の低下をもたらす欠点
に加えてここに得られる窒化けい素粉体は針状物が多く
、焼結性が低下する欠点も看過され難い。However, heat treatment is performed in ammonia, II+
Even if halogens can be removed, ammonia corrodes furnace materials such as alumina and mullite, reducing the lifespan of the furnace materials and easily causing impurity contamination from the furnace materials. In addition to the drawback that the content of ^ψ elements in the raw powder increases, resulting in a decrease in the high-temperature properties of the sintered body, the silicon nitride powder obtained here has many needle-like objects, resulting in a decrease in sinterability. Its shortcomings are also hard to overlook.

発明者らはかかる従来法における未解決の問題点を克服
しようとして種々検討を行ない実験を重ねた結果、ハロ
ゲン化けい素または水素化ハロゲン化けい素とアンモニ
アとを６００〜１６００℃の気相で反応させて得られる
反応生成物を、アンモニア含有ガス中で熱処理する際に
、炉材の侵食が生じない比較的低い温度であっても反応
生成物中のハロゲンを除き得ることを究明し、とくにか
かる脱ハロゲンを行なった反応生成物を更に不活１ガス
中で熱処理するごとにより、−貫した不活性ガス中の熱
処理のみではα晶化しにくいような比較的低い温度で容
易にα晶化させることができ、てこに、アンモニア昇囲
気中での熱処理ち継続する場合のような炉材の侵食が生
じることがなく、その上窒化けい素中の酸素含量も有利
に低減でき、更１゛１ごはアンモニア雰囲気中の熱処理
のみでは、酸−□が関与した気相成長により生成すると
考えられ条針状物の生成も大きく抑制できることなどが
逐次に判明した。The inventors conducted various studies and repeated experiments in an attempt to overcome the unresolved problems in the conventional methods, and found that silicon halides or hydrogenated silicon halides and ammonia were mixed in a gas phase at 600 to 1600°C. It was discovered that when the reaction product obtained by the reaction is heat-treated in an ammonia-containing gas, the halogen in the reaction product can be removed even at a relatively low temperature that does not cause corrosion of the furnace material. By further heat-treating the dehalogenated reaction product in an inert gas, it can be easily alpha-crystallized at a relatively low temperature that would be difficult to alpha-crystallize by heat treatment alone in a penetrating inert gas. In addition, corrosion of the furnace material does not occur as in the case of continuous heat treatment in an atmosphere of elevated ammonia, and furthermore, the oxygen content in silicon nitride can be advantageously reduced. It has been successively discovered that heat treatment in an ammonia atmosphere alone can greatly suppress the formation of needle-like objects, which are thought to be formed by vapor phase growth involving acid.

この発明、はこれらの知見にもとずいて完成したもので
あって、ハロゲン化けい素または水素化ハロゲン化けい
素とこれに対しでモル比０．１〜１．８５のアンモニア
とを、６００〜１５００℃の気相で反応させて得られた
反応生成物を、アンモニア含有ガス中で加熱すること、
次いで不活性ガス中で加熱することの結合により、高純
度で、ハロゲンおよび酸素の含有量が少ない無定形また
はα晶形の窒化けい素である点で焼結原料として格段に
優れた窒化けい素粉体の提供を、現実に可能としたので
ある。This invention was completed based on these findings, and consists of silicon halide or hydrogenated silicon halide and ammonia in a molar ratio of 0.1 to 1.85 to 600 heating the reaction product obtained by reacting in the gas phase at ~1500°C in an ammonia-containing gas;
Next, by heating in an inert gas, a silicon nitride powder with high purity and an amorphous or α-crystalline form with a low content of halogen and oxygen, which is extremely excellent as a sintering raw material, is produced. This made it actually possible to donate one's body.

以下、この発明の詳細な説明する。The present invention will be described in detail below.

この発明の方法の出発物質として使用するハロゲン化け
い素または水素化ハロゲン化けい素としては、５ｉＯｌ
、　５ｉＢｒ　　、　Ｓｉｌ　　や５ｊ−ＨＣｌ２．５
ｉＨＢｒ、。The silicon halide or hydrogenated silicon halide used as a starting material for the process of this invention includes 5iOl
, 5iBr, Sil and 5j-HCl2.5
iHBr,.

４　　　　　　　　４　　　　　　　４ＳｉＩ（Ｉ　　
もしくはＳｉｎ　Ｃｌ　　＋　ＳｉＨ，Ｂｒｇｒ　Ｓｉ
Ｈ，Ｉ、な８　　　　　　　　　　　　　　２　　２Ｖ
、ＩしＳｉｎ、Ｏ７，５ｉＨ８Ｂｒ　、　５ｉＨ８Ｉ　
ｇらにはＳ’１０１２Ｂｒ、２゜１９１０７、Ｉ、など
であり、これらとアンモニアとの反馬は温度６００〜１
５００℃の気相にて行なわれそ。4 4 4SiI(I
Or Sin Cl + SiH, Brgr Si
H, I, na8 2 2V
, ISin, O7,5iH8Br, 5iH8I
Examples include S'1012Br, 2゜19107, I, etc., and the reaction between these and ammonia is at a temperature of 600 to 1
It will be carried out in the gas phase at 500°C.

ここに四塩化けい素など室温で液状や、また固例状を呈
するものは適当に加温して蒸気とし、必要、であれば窒
素やアルゴンなどの不活性ガスを牛ヤリャーとして、ア
ンモニアと反応させるのが好ましい。Here, silicon tetrachloride, which is liquid or solid at room temperature, is heated appropriately to form steam, and if necessary, reacted with ammonia using an inert gas such as nitrogen or argon. It is preferable to let

反応温度は６００℃よりも低すぎ邸と、反応時多量に生
成するハロゲン化アンモニウムが反応炉低温部に堆積し
炉の閉塞をひき起し、また１５００°Ｃをこえるとアン
モニアの熱分解速度が早すぎて反応効率の低下を来たす
。反応時間は特に限定しないが、比較的速やかに反応を
生じるので、長時間行なう必要はない。If the reaction temperature is too low than 600°C, a large amount of ammonium halide produced during the reaction will accumulate in the low temperature part of the reactor, causing clogging of the reactor, and if it exceeds 1500°C, the rate of thermal decomposition of ammonia will decrease. If it is too fast, the reaction efficiency will decrease. The reaction time is not particularly limited, but since the reaction occurs relatively quickly, it is not necessary to carry out the reaction for a long time.

こうして得られた反応生成物はまずアンモニア含有ガス
中で加熱し、次いで不活性ガス中で加熱を行ないこの二
段処理がこの発明の目的に照らして重要である。その具
体的な方法としては、■　アンモニア含有ガス中で加熱
した後、雰囲気ガスを不活性ガスに切換えて加熱を継続
する。The reaction product thus obtained is first heated in an ammonia-containing gas and then heated in an inert gas, and this two-stage treatment is important in view of the purpose of the present invention. The specific method is as follows: (1) After heating in an ammonia-containing gas, the atmospheric gas is switched to an inert gas and heating is continued.

■　アンモニア含有ガス中で加熱し、脱ハロゲンを行な
った反応生成物を移送し、不活性ガス雰、囲気に保った
炉中にて加熱を行なう。(2) The reaction product, which has been dehalogenated by heating in an ammonia-containing gas, is transferred and heated in a furnace maintained in an inert gas atmosphere.

徹どがあげられるがこれらに限定されるものでは；い。This includes thorough implementation, but is not limited to these.

ここでアンモニア含有ガスとは、アンモニアガスのみの
場合と、アンモニアガスを他のガスにて希釈した場合と
を包含し、希釈ガスのアンモニア含有）量は少くとも２
０容積釜で、残りは音素および／またはアルゴンガスで
あるものが好ましい。ここにアンモニアの含有量が２０
容積％未満であると、ハロゲンの除去に対する効果が認
められない。Here, the ammonia-containing gas includes ammonia gas alone and ammonia gas diluted with another gas, and the ammonia content of the diluted gas is at least 2
Preferably, it is a 0 volume pot, with the remainder being phonemes and/or argon gas. The ammonia content here is 20
If the amount is less than % by volume, no effect on halogen removal will be observed.

次にアンモニア含有ガス中の加熱は１００〜１４００℃
好ましくは５００〜１４００℃ざらに好ましくは９００
〜１４００　”Ｃで５０時間〜１゜分間行なうのが好ま
しい０１００°Ｃ未満ではハロゲンの除去効果が認めら
れず、また１　４００　”Ｃを超るとハロゲンの除去効
果の向上は期待できずしてしかも炉材の侵食が多くなり
、ざらに背化けい素中の酸素含量も多くなるだけでなく
針状物の生成が多くなる０加熱時間は１０分間に満たな
いとハロゲンの除去効果が実質的に認められずまた６０
時間をこえて長時間にわたらせてもハロゲン除去効果の
向上は望めず、不経済である。Next, heating in ammonia-containing gas is from 100 to 1400℃.
Preferably 500-1400℃, preferably 900℃
It is preferable to carry out the treatment at ~1400"C for 50 hours to 1°C. Below 0.100"C, the halogen removal effect is not observed, and when it exceeds 1400"C, no improvement in the halogen removal effect can be expected. Moreover, the corrosion of the furnace material increases, the oxygen content in the rough silicon increases, and the formation of needle-like substances increases.If the heating time is less than 10 minutes, the halogen removal effect is not substantial. 60 again due to not being recognized by
Even if it continues for a long time, no improvement in the halogen removal effect can be expected and it is uneconomical.

次に後段加熱での不活性ガスというのは窒素、アヤゴン
ときにはヘリウムなどを含むが、窒素お畜；び／または
アルゴンが実際上好ましい。Next, the inert gas used in the post-heating includes nitrogen, helium, etc., but nitrogen and/or argon are practically preferred.

不活性ガス中での加熱は１０００−１６５０’Ｃ「８０
時間〜１０分間行なうことが好ましい。Heating in inert gas is 1000-1650'C "80
It is preferable to carry out for 10 minutes.

１０００℃未満ではこの加熱処理による酸素低減！１７
）−：効果が少なく、また１６５０”Ｃをこえると窒化
番フい素がβ晶化してしまい焼結原料として適さなくｌ
なる。更に好ましくは１４００〜１６５０　”Ｃの温度
域で加熱することにより単に一貫して不活性雰囲気中で
の熱処理をしただけでは全くのぞみ得ないα晶化が進み
、かつ針状物が少ない窒化けい素粉体が得られる。加熱
時間は１ｏ分間に満たないと酸素除去の効果がなく８０
時間をこえると酸素除去の効果の向上は望めず不経済と
なる。At temperatures below 1000℃, this heat treatment reduces oxygen! 17
)-: Less effective, and when the temperature exceeds 1650"C, fluorine nitride becomes β crystallized, making it unsuitable as a sintering raw material.
Become. More preferably, silicon nitride is heated in a temperature range of 1,400 to 1,650"C to promote alpha crystallization, which cannot be achieved by simply consistently heat-treating in an inert atmosphere, and to produce silicon nitride with fewer needles. A powder is obtained.If the heating time is less than 1 minute, oxygen removal will not be effective and 80%
If the time is exceeded, no improvement in the oxygen removal effect can be expected and it becomes uneconomical.

以上説明した如く、　この発明によれば、ハロゲンおよ
び酸素の含有量の少ない高純度の窒化けい素粉体が得ら
れ、またアルミナやムライトなどの炉材の侵食をも防止
す、ることかできるのみならずα−窒化けい素を主体と
してとくに針状物が少ない窒化けい素粉体が有利に得ら
れる。As explained above, according to the present invention, high purity silicon nitride powder with low halogen and oxygen contents can be obtained, and it is also possible to prevent corrosion of furnace materials such as alumina and mullite. In addition, a silicon nitride powder containing α-silicon nitride as a main component and having particularly few needles can be advantageously obtained.

この発明の方法に従うとき、ハロゲン含有量は０．５重
量係以下、酸素含有量８重量−以下であり、無一定形ま
たはα晶形の５ｉｓＮ４であって、しかも針状物の生ｒ
ｉｔｅが２０％以下であるような、著しい高品質化が達
せられる。ここにα−８ｉ８Ｎ、はＸ線討法による同定
、また針状物は電子顕微鏡観察・ヰμる粒子形状の判定
によることとした。When the method of the present invention is followed, the halogen content is 0.5% by weight or less, the oxygen content is 8% by weight or less, the 5isN4 is amorphous or α-crystalline, and the needle-like raw material is
Significantly higher quality can be achieved, such that ite is less than 20%. Here, α-8i8N was identified by X-ray analysis, and needle-like objects were determined by electron microscopic observation and particle shape determination.

１下次表に掲げた実施例についてのべる。1 The examples listed in the table below will be described.

）＼１１．寿□験煮１〜７は、窒素ガスをキャリヤーと
して大して反応させた。反応管は内径４０邸、長さ１０
１００Ｏのアルミナ管であり、縦型管状炉により表に掲
げた各温度に保持した。)\11. Kotobuki Test Boiled 1 to 7 were reacted to a large extent using nitrogen gas as a carrier. The reaction tube has an inner diameter of 40 mm and a length of 10 mm.
It was a 100O alumina tube and was maintained at each temperature listed in the table in a vertical tube furnace.

得られた反応生成物は反応管下部に取り付けた容器にて
捕集した。The obtained reaction product was collected in a container attached to the bottom of the reaction tube.

このとき、反応させた後のガスをガスクロマトグラフィ
ーで分析した結果、塩化水素の生成が認められ一方反応
生成物はＩＲ分析の結果、シリコンイミドとは異なる粉
末であることが確認された。At this time, as a result of gas chromatography analysis of the gas after the reaction, the production of hydrogen chloride was observed, and on the other hand, as a result of IR analysis, it was confirmed that the reaction product was a powder different from silicon imide.

この反応生成物は次のアンモニア含有ガス処理に供した
。すなわち反応生成物をアルミナ製炉心管中に挿入し、
電気炉にて表に記した所定温度、所定時間にわたる加熱
を、窒素ガスによる希釈で所定のアンモニア含有量に調
整し、または希釈をしないアンモニアガス流中で行なっ
た。次いでアンモニア含有ガスを止めその代わりに不活
性ガス層流して置換を行なった上で不活性ガス処理を、
同表の所定温度、所定時間にわたる加熱下に行なった。This reaction product was subjected to the next ammonia-containing gas treatment. That is, the reaction product is inserted into an alumina furnace tube,
Heating was carried out in an electric furnace at the specified temperature and for a specified period of time as shown in the table, and the ammonia content was adjusted to a specified value by dilution with nitrogen gas, or in a stream of ammonia gas without dilution. Next, the ammonia-containing gas is stopped and replaced with an inert gas laminar flow, and the inert gas treatment is performed.
The test was carried out under heating at the specified temperature and for the specified period of time shown in the same table.

上記の２段階加熱処理して得られた窒化けい素１末につ
いて、酸素含量は酸素分析Ｈ１（レフ社；９ｉ０−１８
）にて、塩素含量はけい光Ｘ線法にて１また結晶形はＸ
線回折法にてそれぞれ分析を行なった。結果を表１に示
す。なお表の製品の分析結果の欄においてα／βが９０
％以上のものをα晶ノ膝とした。The oxygen content of silicon nitride 1 powder obtained by the above two-step heat treatment was determined by oxygen analysis H1 (Ref Corporation; 9i0-18
), the chlorine content was determined to be 1 by the fluorescent X-ray method, and the crystal form was
Each was analyzed using a line diffraction method. The results are shown in Table 1. In addition, α/β is 90 in the column of product analysis results in the table.
% or more was regarded as α crystal knee.

また、窒化けい素粉末の電顕写真を撮り、粒子形状を観
察した結果の１例を、第１図に示した。Further, an example of the results of taking an electron micrograph of silicon nitride powder and observing the particle shape is shown in FIG.

また長径／短径比が５以上の針状物と５以下の粒状物の
面積割合を測定した結果、いずれの場合も針状物の含有
は２０％以下でそれぞれ表に併記したとおりであった。In addition, as a result of measuring the area ratio of needles with a length/breadth ratio of 5 or more and granules with a ratio of 5 or less, the content of needles was 20% or less in both cases, as shown in the table. .

実験屋８〜９は、上記の四塩化けい素の代わりに５ｉＨ
Ｏ！８およびＳｉＢｒ４をそれぞれ用いて実験墓１〜７
と同様に実施した結果は、各段階加熱処理条件とともに
表に併記したとおりである。Experimenters 8 to 9 used 5iH instead of the above silicon tetrachloride.
O! Experimental graves 1 to 7 using SiBr4 and SiBr4, respectively.
The results obtained in the same manner as above are shown in the table together with the heat treatment conditions for each stage.

なお実験Ａ１０〜１２は実験Ａｌ〜７と同様の方法で得
た反応生成物を、アンモニア中もしくはアンモニア含有
ガス中および窒素中のみで表に示した条件で加熱した比
較例の結果を示す。Note that Experiments A10 to A12 show the results of comparative examples in which reaction products obtained in the same manner as Experiments Al to 7 were heated only in ammonia or ammonia-containing gas and in nitrogen under the conditions shown in the table.

また実験Ａ　Ｉ　０　、１１の粒子形状を観察した結果
の１例を第２図に示し、実験Ａ１〜７についてｐべた判
定の基準でいずれも針状物の含有は９０−係をこえてい
た。Figure 2 shows an example of the results of observing the particle shapes of Experiments A I 0 and 11, and in Experiments A1 to A7, the content of needles exceeded 90-90 in all cases according to the criteria for determining p solidity. .

上記したこの発明の実施例および比較例により得られた
製品（Ａ　８　＊　Ａ　１０　）の６０００倍の電子°
顕微鏡写真を第１図、第２図に示す。6000 times more electrons than the products (A 8 * A 10 ) obtained in the Examples and Comparative Examples of the present invention described above.
Microscopic photographs are shown in Figs. 1 and 2.

以上のべたようにしてこの発明によれば、ハロゲンおよ
び酸素含有歯が著しく少く、α−８ｉ８Ｎ。As described above, according to the present invention, there are significantly fewer halogen and oxygen-containing teeth, and α-8i8N.

を主体として、しかも針状物の少い微細粉末状の窒化け
い素粉体を有利に得ることができる。It is possible to advantageously obtain a finely powdered silicon nitride powder mainly composed of silicon nitride and having fewer needles.

【図面の簡単な説明】[Brief explanation of the drawing]

第１図、第２図は、この発明の方法と従来法とによって
得られた窒化けい素粉体の粒状形状の対比を示す電子顕
微鏡写真である。 特許出願人　−Ｃ−１１支幅院を 第１図 第２図FIGS. 1 and 2 are electron micrographs showing a comparison of the granular shapes of silicon nitride powder obtained by the method of the present invention and the conventional method. Patent applicant - C-11 branch office Figure 1 Figure 2

Claims (1)

【特許請求の範囲】 Ｌ　ハロゲン化けい素または水素化ハロゲン化けい素と
アンモニアとを、６ｏｏ〜１５００℃の温度の気相で反
応させて得られる反応生成物につき、 アンモニア含有ガス中で加熱すること、次いで不活性ガ
ス中にて加熱する、こと、を結合して、ハロゲン含有ｆ
ｉＯ，５重量％以下でがっ酸素含有思８重量俤以下であ
って、Ｘ＃ｊ回折法による同定で無定形またはα晶形の
５ｉ８Ｎ。 でありしかも、電子顕微鏡観察による粒子形状の判定で
針状物の含有が２０％以下の微細粉状生成物を得ること
を特徴とする窒化けい素粉体の製造方法。 、ａ　アンモニア含有ガスが、アンモニアまたはその含
有量が少くとも２ｏ容Ｊ１％と残り窒素および／もしく
はアルゴンであり、不活性ガスが、窒素および／または
アルゴンである、１記載の方法。 ＆　アンモニア含有ガス中での加熱が、１００〜１４０
０°Ｃで、５０時間〜１０分間、不活性ガス中での加熱
が、１０００〜１６５０°Ｃにて８０時間〜１０分間に
、それぞれわたるものである、１または２・記載の方法
。[Scope of Claims] L A reaction product obtained by reacting silicon halide or hydrogenated silicon halide with ammonia in a gas phase at a temperature of 6oo to 1500°C, heated in an ammonia-containing gas. and then heating in an inert gas, the halogen-containing f
5i8N containing less than 5% by weight of iO and less than 8% by weight of oxygen, and which is amorphous or α-crystalline as identified by X#j diffraction method. A method for producing silicon nitride powder, characterized in that a fine powder product containing 20% or less of needle-shaped particles is obtained as determined by particle shape by electron microscopy. , a The method according to 1, wherein the ammonia-containing gas is ammonia or its content is at least 2O volume J1% and the remainder nitrogen and/or argon, and the inert gas is nitrogen and/or argon. & Heating in ammonia-containing gas is 100 to 140
2. The method according to 1 or 2, wherein the heating in an inert gas is performed at 0°C for 50 hours to 10 minutes and at 1000 to 1650°C for 80 hours to 10 minutes, respectively.