JP2586609B2 - Method for producing fine α-alumina powder - Google Patents
Method for producing fine α-alumina powderInfo
- Publication number
- JP2586609B2 JP2586609B2 JP63275256A JP27525688A JP2586609B2 JP 2586609 B2 JP2586609 B2 JP 2586609B2 JP 63275256 A JP63275256 A JP 63275256A JP 27525688 A JP27525688 A JP 27525688A JP 2586609 B2 JP2586609 B2 JP 2586609B2
- Authority
- JP
- Japan
- Prior art keywords
- alumina
- alumina powder
- size
- powder
- fine
- 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
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- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
【発明の詳細な説明】 （利用分野） 本発明は硬度特性，研磨特性や焼結特性にすぐれかつ
大きさの均一な微細α−アルミナ粉末の製造方法に関す
る。Description: FIELD OF THE INVENTION The present invention relates to a method for producing a fine α-alumina powder having excellent hardness characteristics, polishing characteristics and sintering characteristics and uniform size.
（従来技術とその問題点） 現在アルミナの用途としては、セラミツクス原料，触
媒，触媒の担体，耐火物，焼結体，骨材，研削材，研磨
材等への利用が知られているが、その製造方法はバイヤ
ー法と呼ばれる通常の湿式法で得られたアルミン酸ソー
ダを酸で中和して水酸化アルミニウムとし、これを高温
（1,200℃以上）で焼成するのが一般的である。しか
し、この製造方法では水酸化アルミニウムを生成させ、
これを焼成すると得られたアルミナ粒子の大きさは1,20
0℃以上で長時間加熱するので、不均一で、しかも該粒
子は粒子同志の焼結が起こり、１μｍ以上の粗大なもの
になる。又α−アルミナ粉末はAlアルコキシド、例え
ば、Alイソプロポキシドの加水分解によつて水酸化アル
ミニウムを生成し、これを高温でα−アルミナ化するこ
とによつても得られることが知られているが、微細なα
−アルミナを得ようとすると、アルコキシドの加水分解
を均一にする必要があり、生産性が悪くなる。(Prior art and its problems) At present, alumina is known to be used for ceramic materials, catalysts, catalyst carriers, refractories, sintered bodies, aggregates, abrasives, abrasives, etc. In the production method, sodium aluminate obtained by an ordinary wet method called a Bayer method is generally neutralized with an acid to obtain aluminum hydroxide, which is fired at a high temperature (1,200 ° C. or higher). However, this method produces aluminum hydroxide,
The size of the alumina particles obtained by firing this was 1,20
Since the particles are heated at a temperature of 0 ° C. or more for a long time, the particles are non-uniform, and the particles are sintered by each other, resulting in coarse particles of 1 μm or more. It is known that α-alumina powder can also be obtained by producing aluminum hydroxide by hydrolysis of an Al alkoxide, for example, Al isopropoxide, and converting this to α-alumina at a high temperature. But fine α
-In order to obtain alumina, it is necessary to make the hydrolysis of the alkoxide uniform, resulting in poor productivity.
（発明の目的） 本発明者らは上記の従来技術の問題点を解決し、硬度
特性、研磨特性や焼結特性にすぐれ、かつ大きさの均一
な微細α−アルミナ粉末の製造方法を提供すべく、研究
を重ねた結果、三塩化アルミニウムをγ−アルミナ粉末
とし、かつγ−アルミナ粉末を造粒して焼成することに
よつて、前記目的を達成し得ることを見出し、本発明に
到達した。(Object of the Invention) The present inventors have solved the above-mentioned problems of the prior art and provided a method for producing fine α-alumina powder having excellent hardness characteristics, polishing characteristics and sintering characteristics, and having a uniform size. As a result of repeated studies, the present inventors have found that the above object can be achieved by converting aluminum trichloride into γ-alumina powder, and granulating and firing γ-alumina powder. .
（発明の構成） すなわち、本発明によれば、酸水素炎中で三塩化アル
ミニウムを反応させて得たγ−アルミナ粉末を、10μｍ
以上のサイズに造粒して焼成することを特徴とする大き
さ１μｍ以下の微細α−アルミナ粉末の製造方法、が得
られる。(Constitution of the Invention) That is, according to the present invention, γ-alumina powder obtained by reacting aluminum trichloride in an oxyhydrogen flame is 10 μm
A method for producing a fine α-alumina powder having a size of 1 μm or less, characterized by granulating and firing to the above size, is obtained.
本発明者らは上記のように、研究の結果、三塩化アル
ミニウムを酸水素炎中で反応させて得たγ−アルミナ
（2AlCl3＋3H2O→Al2O3＋6HCl）は0.02μｍと粒子の大
きさは小さいが、非常に均一であるため、α−アルミナ
化した時に粒子がそろい易いこと、及びこのγ−アルミ
ナ粉末を造粒して焼成すると、α−アルミナ化を促進す
ることを見出したのである。ここでいうγ−アルミナと
は低温で生成するアルミナのことで、Ｘ線的にはδ，
γ，θ等のアルミナの総称を意味する。As described above, the present inventors have found that γ-alumina (2AlCl 3 + 3H 2 O → Al 2 O 3 + 6HCl) obtained by reacting aluminum trichloride in an oxyhydrogen flame has a particle size of 0.02 μm as described above. Although the size was small, it was found to be very uniform, so that the particles were easy to form when converted to α-alumina, and that when the γ-alumina powder was granulated and fired, the α-alumina was promoted. It is. Here, γ-alumina is alumina produced at a low temperature, and δ,
A general term for alumina such as γ and θ.
本発明においては、γ−アルミナ粉末を10μｍ以上の
サイズに造粒することが要求される。これは造粒のサイ
ズが10μｍ未満ではγ−アルミナのα−アルミナ化の促
進に効果がないからである。又造粒のサイズの上限はな
いが、実際の生産上は通常5mm以下となる。この場合の
造粒と焼成温度、焼成時間の関係は次の如くである。In the present invention, it is required that γ-alumina powder is granulated to a size of 10 μm or more. This is because if the granulation size is less than 10 μm, there is no effect in promoting the conversion of γ-alumina to α-alumina. Although there is no upper limit on the size of granulation, it is usually 5 mm or less in actual production. In this case, the relationship between granulation, firing temperature and firing time is as follows.
因みに、γ−アルミナからα−アルミナへの転換温度
は1,150℃〜1,250℃の範囲であり、1,150℃未満ではα
−アルミナ化に長時間かかり、又1,250℃以上ではα−
アルミナ粒子が１μｍ以上の大きさに成長する。 Incidentally, the conversion temperature from γ-alumina to α-alumina ranges from 1,150 ° C. to 1,250 ° C.
-It takes a long time for aluminization, and α-
Alumina particles grow to a size of 1 μm or more.
次に、γ−アルミナ粉末を10μｍ以上のサイズに造粒
する方法は次の如きものである。Next, a method of granulating the γ-alumina powder to a size of 10 μm or more is as follows.
（１） γ−アルミナ粉末に水またはバインダーを該γ
−アルミナの0.1％〜５％の範囲に含む水を加えてペー
スト状にし、これを乾燥して軽く粉砕し、ふるいに通し
て所要サイズに造粒する方法、 （２） γ−アルミナ粉末に水を加えて泥漿状にしてス
プレードライし、これを所要サイズに造粒する方法、 （３） γ−アルミナ粉末をダイスを用いてプレスまた
は静水圧プレスし、これを軽く粉砕してふるいに通し、
所要サイズに造粒する方法、 （４） 通常の造粒機（例えば、不二パウダル社のスパ
ルタンリユーザー等）を用いる方法。(1) Water or binder is added to γ-alumina powder
A method in which water containing 0.1% to 5% of alumina is added to form a paste, which is dried, lightly crushed, and granulated to a required size through a sieve; (2) water is added to γ-alumina powder; (3) γ-alumina powder is pressed or isostatically pressed using a die, gently pulverized and passed through a sieve,
(4) A method using an ordinary granulator (for example, a Spartan re-user of Fuji Paudal).
このように、本発明においては、酸水素炎中で三塩化
アルミニウムを反応させてγ−アルミナ粉末をつくり、
このγ−アルミナ粉末を10μｍ以上のサイズに造粒する
と、α−アルミナ化は促進され、例えば、焼成温度を1,
200℃とすると、焼成時間は造粒しない場合の1/10の１
時間でよく、大きさは１μｍ以下で均一な微細α−アル
ミナ粉末が得られるのである。このα−アルミナ粉末は
もちろん硬度特性，研磨特性及び焼結特性にすぐれたも
のである。Thus, in the present invention, aluminum trichloride is reacted in an oxyhydrogen flame to produce γ-alumina powder,
When this γ-alumina powder is granulated to a size of 10 μm or more, α-alumina formation is promoted.
Assuming 200 ° C, firing time is 1/10 of the case without granulation
Time is sufficient, and a uniform fine α-alumina powder having a size of 1 μm or less can be obtained. This α-alumina powder is of course excellent in hardness characteristics, polishing characteristics and sintering characteristics.
次に、本発明を実施例によつてさらに具体的に説明す
るが、これら実施例は本発明の範囲を限定するものでは
ない。Next, the present invention will be described more specifically with reference to examples, but these examples do not limit the scope of the present invention.
実施例１ 三塩化アルミニウムを酸水素炎中で反応させて得たア
ルミナ（デグサ社製アルミナOxide C）粉末400gをPVA
（ポリビニールアルコール）8gを溶かした水１に混練
し110℃で乾燥後軽く粉砕しながらふるい分けを行な
い、100〜200μｍのサイズに造粒した。Example 1 400 g of alumina (alumina Oxide C manufactured by Degussa) powder obtained by reacting aluminum trichloride in an oxyhydrogen flame was used for PVA.
(Polyvinyl alcohol) 8 g was dissolved in water 1 and kneaded, dried at 110 ° C., sieved while lightly pulverized, and granulated to a size of 100 to 200 μm.
これをアルミナポートに入れ、マツフル炉にて1,200
℃で１時間焼成した。得られた粉末の比表面積は10.0m2
/g（約0.2μｍ）であり、電子顕微鏡写真によると、ほ
ぼ球形で粒子の大きさは均一であつた。Ｘ線回折ではα
相のピークのみが得られた。Put this in an alumina port and use a Matsufuru furnace for 1,200
Calcination was carried out at ℃ for 1 hour. The specific surface area of the obtained powder is 10.0 m 2
/ g (about 0.2 μm). According to the electron micrograph, it was almost spherical and the particle size was uniform. Α in X-ray diffraction
Only phase peaks were obtained.
実施例２ デグサ社製アルミナOxide C 400gを水１に混練し、
ヤマト科学社製スプレードライヤーで約20μｍのサイズ
に造粒し、これを1,250℃で30分焼成した。生成した粉
末の比表面積は15m2/g（約0.1μｍ）であり、電子顕微
鏡写真では粒子は球状で大きさは均一であり、又Ｘ線回
折ではα相のピークのみであつた。Example 2 400 g of alumina Oxide C manufactured by Degussa Kneaded in water 1
It was granulated to a size of about 20 μm with a spray dryer manufactured by Yamato Scientific Co., Ltd., and calcined at 1,250 ° C. for 30 minutes. The specific surface area of the produced powder was 15 m 2 / g (approximately 0.1 μm), the particles were spherical and uniform in size in an electron micrograph, and only the α phase peak was found in the X-ray diffraction.
実施例３ デグサ社製アルミナOxide C 20gを鋼製ダイス（径2c
m）を用い、１トン/cm2の圧力でプレスをした。プレス
後は固まつた状態であるが、これを軽く砕きながら1mm
〜4mmの間の粒子とした。これを1,180℃において４時間
焼成した。得られた粉末の比表面積は8m2/g（0.2μｍ）
であり、電子顕微鏡写真では粉末は球状で大きさは均一
であり、又Ｘ線回折ではα相のピークのみであつた。Example 3 20 g of alumina Oxide C manufactured by Degussa Co., Ltd. was
m) and pressed at a pressure of 1 ton / cm 2 . After pressing, it is in a solid state, but while crushing it lightly 1 mm
Particles between 44 mm. This was fired at 1,180 ° C. for 4 hours. The specific surface area of the obtained powder is 8m 2 / g (0.2μm)
In the electron micrograph, the powder was spherical and uniform in size, and the X-ray diffraction showed only a peak of the α phase.
比較例１ デグサ社製アルミナOxide Cを造粒せずに、そのまま
1,200℃で１時間焼成した。得られた粉末のＸ線回折で
は、わずかにα−アルミナのピークが認められるが、ま
だほとんどがγ−アルミナのままであつた。Comparative Example 1 Alumina Oxide C manufactured by Degussa Co., without granulation
Baking was performed at 1,200 ° C. for 1 hour. In the X-ray diffraction of the obtained powder, a slight peak of α-alumina was recognized, but most of the powder was still γ-alumina.
比較例２ 市販の水酸化アルミニウム400gを実施例１と同様に造
粒し、これをアルミナポートに入れ、マツフル炉にて1,
200℃で１時間焼成した。得られた粉末の比表面積は3.1
m2/g（約0.7μｍ）であり、Ｘ線回折ではα相のピーク
のみであつたが、電子顕微鏡写真では、１μｍ以上の粒
子と細かい粒子との混合であり、不均一なものであつ
た。Comparative Example 2 400 g of commercially available aluminum hydroxide was granulated in the same manner as in Example 1 and put into an alumina port.
It was baked at 200 ° C. for 1 hour. The specific surface area of the obtained powder is 3.1
m 2 / g (approximately 0.7 μm). In the X-ray diffraction, there was only the peak of the α phase. However, in the electron micrograph, it was a mixture of particles of 1 μm or more and fine particles, and was uneven. Was.
（発明の効果） 本発明は上記の如く、酸水素炎中で反応させて得たγ
−アルミナ粉末を用い、これを造粒するという構成をと
ることによつて、次の効果を示す。(Effect of the Invention) As described above, the present invention provides γ obtained by reacting in an oxyhydrogen flame.
-The following effects are obtained by using an alumina powder and granulating it.
（１） １μｍ以下でかつ均一な大きさのα−アルミナ
粉末をうることができる。(1) An α-alumina powder having a uniform size of 1 μm or less can be obtained.
（２） 焼成時間を大幅に短縮することまたは焼成温度
を大幅に低下させることができる。(2) The firing time can be significantly reduced or the firing temperature can be significantly reduced.
Claims (4)
せて得たγ−アルミナ粉末を、10μｍ以上のサイズに造
粒して焼成することを特徴とする大きさ１μｍ以下の微
細α−アルミナ粉末の製造方法。1. A fine .alpha.-alumina powder having a size of 1 .mu.m or less, characterized in that .gamma.-alumina powder obtained by reacting aluminum trichloride in an oxyhydrogen flame is granulated to a size of 10 .mu.m or more and fired. Powder manufacturing method.
ルミナ粉末の製造方法であつて、該γ−アルミナ粉末に
水またはバインダーを該γ−アルミナの0.1％〜５％の
範囲に含む水を加えてペースト状にし、これを乾燥して
軽く粉砕し、ふるいに通して所要サイズに造粒すること
を特徴とする該製造方法。2. The method for producing a fine α-alumina powder according to claim 1, wherein water or a binder is added to the γ-alumina powder in a range of 0.1% to 5% of the γ-alumina. The method according to claim 1, wherein water is added to form a paste, which is dried, lightly pulverized, and passed through a sieve to granulate to a required size.
ルミナ粉末の製造方法であつて、該γ−アルミナ粉末に
水を加えて泥漿状にしてスプレードライし、これを所要
サイズに造粒することを特徴とする該製造方法。3. A method for producing a fine α-alumina powder according to claim 1, wherein water is added to the γ-alumina powder to form a slurry, which is spray-dried, and the powder is reduced to a required size. The production method, characterized by granulating.
ルミナ粉末の製造方法であつて、該γ−アルミナ粉末を
ダイスを用いてプレスまたは静水圧プレスし、それを軽
く粉砕してふるいに通し、所要サイズに造粒することを
特徴とする該製造方法。4. The method for producing fine α-alumina powder according to claim 1, wherein said γ-alumina powder is pressed or isostatically pressed using a die, and lightly pulverized. The method according to claim 1, wherein the mixture is passed through a sieve and granulated to a required size.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63275256A JP2586609B2 (en) | 1988-10-31 | 1988-10-31 | Method for producing fine α-alumina powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63275256A JP2586609B2 (en) | 1988-10-31 | 1988-10-31 | Method for producing fine α-alumina powder |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH02124711A JPH02124711A (en) | 1990-05-14 |
| JP2586609B2 true JP2586609B2 (en) | 1997-03-05 |
Family
ID=17552879
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP63275256A Expired - Lifetime JP2586609B2 (en) | 1988-10-31 | 1988-10-31 | Method for producing fine α-alumina powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2586609B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100950165B1 (en) | 2002-01-16 | 2010-03-30 | 스미또모 가가꾸 가부시키가이샤 | Calcined alumina, its production method and fine ?-alumina powder obtained by using the calcined alumina |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994014988A1 (en) * | 1992-12-24 | 1994-07-07 | Commonwealth Scientific And Industrial Research Organisation | Agglomeration of alumina material |
| CN102502745B (en) * | 2011-11-25 | 2014-05-14 | 苏州华微特粉体技术有限公司 | Manufacture method and device of nanometer alumina powder |
-
1988
- 1988-10-31 JP JP63275256A patent/JP2586609B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100950165B1 (en) | 2002-01-16 | 2010-03-30 | 스미또모 가가꾸 가부시키가이샤 | Calcined alumina, its production method and fine ?-alumina powder obtained by using the calcined alumina |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH02124711A (en) | 1990-05-14 |
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