JPH05294615A - Alumina powder for single crystal production raw material - Google Patents
Alumina powder for single crystal production raw materialInfo
- Publication number
- JPH05294615A JPH05294615A JP4121133A JP12113392A JPH05294615A JP H05294615 A JPH05294615 A JP H05294615A JP 4121133 A JP4121133 A JP 4121133A JP 12113392 A JP12113392 A JP 12113392A JP H05294615 A JPH05294615 A JP H05294615A
- Authority
- JP
- Japan
- Prior art keywords
- single crystal
- alumina powder
- raw material
- alumina
- metal
- 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.)
- Pending
Links
- 239000013078 crystal Substances 0.000 title claims abstract description 51
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 239000000843 powder Substances 0.000 title claims abstract description 30
- 239000002994 raw material Substances 0.000 title claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 title abstract description 12
- 229910052751 metal Inorganic materials 0.000 claims abstract description 15
- 239000002184 metal Substances 0.000 claims abstract description 15
- 150000001875 compounds Chemical class 0.000 claims abstract description 9
- 150000002739 metals Chemical class 0.000 claims abstract description 5
- 238000010438 heat treatment Methods 0.000 abstract description 15
- 238000002845 discoloration Methods 0.000 abstract 1
- 238000004904 shortening Methods 0.000 abstract 1
- 239000011800 void material Substances 0.000 abstract 1
- 238000000034 method Methods 0.000 description 25
- 239000012535 impurity Substances 0.000 description 11
- 230000000052 comparative effect Effects 0.000 description 6
- 150000003839 salts Chemical class 0.000 description 6
- 229910052782 aluminium Inorganic materials 0.000 description 3
- 235000011124 aluminium ammonium sulphate Nutrition 0.000 description 3
- LCQXXBOSCBRNNT-UHFFFAOYSA-K ammonium aluminium sulfate Chemical compound [NH4+].[Al+3].[O-]S([O-])(=O)=O.[O-]S([O-])(=O)=O LCQXXBOSCBRNNT-UHFFFAOYSA-K 0.000 description 3
- 238000004040 coloring Methods 0.000 description 3
- 238000010304 firing Methods 0.000 description 3
- 239000005357 flat glass Substances 0.000 description 3
- 239000002002 slurry Substances 0.000 description 3
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- -1 aluminum compound Chemical class 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 238000005520 cutting process Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000007062 hydrolysis Effects 0.000 description 2
- 238000006460 hydrolysis reaction Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000005498 polishing Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 1
- YZCKVEUIGOORGS-OUBTZVSYSA-N Deuterium Chemical compound [2H] YZCKVEUIGOORGS-OUBTZVSYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- WNROFYMDJYEPJX-UHFFFAOYSA-K aluminium hydroxide Chemical compound [OH-].[OH-].[OH-].[Al+3] WNROFYMDJYEPJX-UHFFFAOYSA-K 0.000 description 1
- SMZOGRDCAXLAAR-UHFFFAOYSA-N aluminium isopropoxide Chemical compound [Al+3].CC(C)[O-].CC(C)[O-].CC(C)[O-] SMZOGRDCAXLAAR-UHFFFAOYSA-N 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910052805 deuterium Inorganic materials 0.000 description 1
- 238000007580 dry-mixing Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000010534 mechanism of action Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000011164 primary particle Substances 0.000 description 1
- 238000001953 recrystallisation Methods 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 238000001694 spray drying Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
- 238000004857 zone melting Methods 0.000 description 1
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、単結晶の製造に際して
その原料として用いられるアルミナ粉末に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an alumina powder used as a raw material for producing a single crystal.
【０００２】[0002]
【従来の技術】従来、単結晶の製造においては、単結晶
の成長を容易にするためにも純度の高い原料が使用され
るのが普通であって、例えばアルミナ粉末から単結晶の
製造方法の１つであるベルヌーイ法によりアルミナ単結
晶を製造する際には、その原料のアルミナ粉末として、
アンモニウムミョウバンを焼成して得られたγ−アルミ
ナが主として用いられている。2. Description of the Related Art Conventionally, in the production of single crystals, it has been customary to use raw materials of high purity also for facilitating the growth of the single crystals. When producing an alumina single crystal by the Bernoulli method, which is one of the methods, as the raw material alumina powder,
Gamma-alumina obtained by firing ammonium alum is mainly used.
【０００３】このアルミナは、Ｎａ，Ｓｉ，Ｆｅ，Ｍｇ
等の不純物を通常数１０ｐｐｍ含有しており、これを単
結晶製造原料として使用した場合には、これらの不純物
が単結晶育成時に結晶の配列を乱し、アルミナ単結晶プ
ール中に気泡が取り込まれるという問題があった。この
ような欠点を解決するため、原料アルミナ粉末を精製
し、不純物濃度を下げたものを使用する方法は、例えば
前記のアンモニウムミヨウバンの再結晶を繰り返して不
純物を除いた後、焼成して得られるアルミナ粉末を原料
として用いる方法等が採用されているが、この場合には
気泡が減少するものの、得られるアルミナ単結晶プール
にＣ面が顕著に現れ、プールが四角柱となる現象が生じ
るため、主として円柱状単結晶が製品形状として要求さ
れる現状においては、四角柱から円柱状への研磨コスト
が増大すると共に製品の収率を大幅に低下させるという
不都合を有する。This alumina is composed of Na, Si, Fe, Mg
When such a single crystal is used as a raw material for producing a single crystal, these impurities disturb the crystal arrangement during the growth of the single crystal, and bubbles are taken into the alumina single crystal pool. There was a problem. In order to solve such a drawback, a method of purifying the raw material alumina powder and using the one with a reduced impurity concentration is, for example, obtained by repeating the recrystallization of the above-mentioned ammonium deuterium to remove the impurities and then firing. Although a method of using the alumina powder as a raw material has been adopted, in this case, although the bubbles are reduced, the C-plane appears prominently in the obtained alumina single crystal pool, and the phenomenon that the pool becomes a square column occurs. In the present situation where a columnar single crystal is mainly required as a product shape, there are disadvantages that the polishing cost from a rectangular column to a column increases and the product yield is significantly reduced.
【０００４】この問題に対応して、気泡、着色がなく、
かつＣ面の発現が抑制された円柱状単結晶を得ることを
目的として、Ｎａ，Ｓｉ，Ｆｅ及びＭｇの金属或いはこ
れら金属の化合物を、Ｎａ，Ｓｉ，Ｆｅ及びＭｇ原子と
して各々２０ｐｐｍ以下を含有し、かつＴｉ金属又は該
金属の化合物をＴｉ原子として１０〜５０ｐｐｍ含有す
るアルミナ粉末をベルヌーイ法単結晶用の原料とするこ
とが提案されており（特開昭６３−１１２４９８号公
報）、この方法によると円柱として切りだせる有効面積
が増大するなどの効果が得られている。In response to this problem, there are no bubbles or coloring,
In addition, for the purpose of obtaining a columnar single crystal in which the expression of the C-plane is suppressed, the metal of Na, Si, Fe and Mg or the compound of these metals contains 20 ppm or less as Na, Si, Fe and Mg atoms, respectively. In addition, it has been proposed to use an alumina powder containing Ti metal or a compound of the metal as a Ti atom in an amount of 10 to 50 ppm as a raw material for a Bernoulli method single crystal (Japanese Patent Laid-Open No. 63-112498). According to the above, the effect that the effective area that can be cut out as a cylinder is increased is obtained.
【０００５】[0005]
【発明が解決しようとする課題】しかし、前記のアルミ
ナ粉末はＴｉ原子を含有せしめたために、この原料アル
ミナ粉末により製造したプールは、次に示すような新た
な問題を生ずるに至った。すなわち、一般にベルヌーイ
法により製造された単結晶プールは、波長が２５４ｎｍ
付近の紫外線を照射することにより黄褐色に着色するこ
とが知られている。一方、アルミナ単結晶プールは現在
腕時計の窓ガラスとして使用され、その需要が大きく伸
びている。そして、その窓ガラスの時計ケースへの組み
込みの際には、紫外線硬化型の接着剤が主として用いら
れている。このため、前記の組み込みの工程において強
力な紫外線が照射されると、ベルヌーイ法により製造さ
れた窓ガラスは黄褐色に着色してしまう。このような不
都合を解決するために、通常アルミナ単結晶プールを高
温で長時間熱処理を行う方法が採用されているが、前記
特開昭６３−１１２４９８号公報のアルミナ粉末を用い
るときには、Ｔｉ原子を含有することにより、前記の熱
処理をしても熱処理の効果が現れ難くなり、熱処理の時
間を大幅に延長させなければならないという、新たな経
済的な不都合を生じさせている。However, since the above-mentioned alumina powder contains Ti atoms, the pool produced from this raw material alumina powder has caused the following new problems. That is, generally, a single crystal pool manufactured by the Bernoulli method has a wavelength of 254 nm.
It is known to be colored yellowish brown by irradiating ultraviolet rays in the vicinity. On the other hand, the alumina single crystal pool is currently used as a window glass for wristwatches, and the demand for it is greatly increasing. When the window glass is incorporated into the watch case, an ultraviolet curable adhesive is mainly used. Therefore, when strong ultraviolet rays are radiated in the assembling step, the window glass manufactured by the Bernoulli method is colored yellowish brown. In order to solve such an inconvenience, a method of heat-treating an alumina single crystal pool at a high temperature for a long time is usually adopted. However, when the alumina powder of JP-A-63-112498 is used, Ti atoms are Due to the inclusion, the effect of the heat treatment is less likely to appear even if the heat treatment is performed, and a new economical inconvenience is caused in that the heat treatment time must be greatly extended.
【０００６】このことから、アルミナ粉末を製造原料と
する単結晶の製造において、気泡、着色がなく、熱処理
時間を長くする必要がなく、かつＣ面の発現が抑制され
た円柱状単結晶を得ることができるアルミナ粉末を得る
ことが望ましく、本発明はこのような条件を満たしたア
ルミナ粉末を得ることを目的とするものである。From the above, in the production of a single crystal using alumina powder as a raw material, there is no bubble or coloration, there is no need to lengthen the heat treatment time, and a cylindrical single crystal in which the expression of the C plane is suppressed is obtained. It is desirable to obtain an alumina powder that can be obtained, and the present invention aims to obtain an alumina powder that satisfies such conditions.
【０００７】[0007]
【課題を解決するための手段】本発明者は、前記の目的
を達成するために鋭意検討した結果、原料アルミナ中の
不純物原子の種類及びその量を種々変えて調べることに
より、前記の目的を達成しうる特定の不純物原子の種類
及びその量を見いだすことにより、本発明を完成した。Means for Solving the Problems As a result of extensive studies to achieve the above-mentioned object, the present inventor found that the above-mentioned object can be achieved by variously investigating the kind and amount of impurity atoms in the raw material alumina. The present invention has been completed by finding the type and amount of specific impurity atoms that can be achieved.
【０００８】すなわち、本発明は、Ｎａ，Ｓｉ，Ｍｇ及
びＦｅの金属或いはこれら金属の化合物を、Ｎａ，Ｓ
ｉ，Ｍｇ及びＦｅ原子として各々２０ｐｐｍ以下、Ｃａ
金属或いは該金属の化合物をＣａ原子として１〜５ｐｐ
ｍ含有することを特徴とする単結晶製造原料用アルミナ
粉末である。Ｎａ，Ｓｉ，Ｍｇ，Ｆｅが上記の範囲を越
える場合には、得られる単結晶に気泡が発生するので、
好ましくない。また、Ｃａ量が上記した１ｐｐｍに満た
ないときにはＣ面の発現を抑えるには十分でなく、他方
５ｐｐｍを越える場合には気泡が発生するので好ましく
ない。That is, according to the present invention, metals such as Na, Si, Mg and Fe or compounds of these metals are added to Na, S.
20 ppm or less for each of i, Mg and Fe atoms, Ca
1 to 5 pp for a metal or a compound of the metal as a Ca atom
It is an alumina powder for a raw material for producing a single crystal characterized by containing m. If Na, Si, Mg, Fe exceeds the above range, bubbles will be generated in the obtained single crystal.
Not preferable. Further, when the amount of Ca is less than 1 ppm described above, it is not sufficient to suppress the development of the C plane, and when it exceeds 5 ppm, bubbles are generated, which is not preferable.
【０００９】また、本発明のアルミナ粉末にはＴｉを添
加してもよく、例えばＴｉ又はその化合物をＴｉ原子と
して２ｐｐｍ以上１０ｐｐｍ未満含有することができる
が、ゼロであってもよい。Ｔｉ量が１０ｐｐｍを越える
場合には、熱処理に長時間を必要とし好ましくない。本
発明の単結晶製造原料用アルミナ粉末は、単結晶を製造
するための種々の製造法に使用することができ、例えば
ベルヌーイ法、結晶引き上げ法、ゾーンメルティング法
などの各製造方法に使用することができるが、なかでも
ベルヌーイ法に好ましく適用することができる。このア
ルミナ粉末はアルミナ単結晶の製造に好ましく用いられ
るが、これを用いて他の組成の単結晶を製造することが
できる場合にはそれらの単結晶の製造にも用いることが
できる。Further, Ti may be added to the alumina powder of the present invention. For example, Ti or its compound may be contained as Ti atoms in an amount of 2 ppm or more and less than 10 ppm, but it may be zero. When the amount of Ti exceeds 10 ppm, it takes a long time for heat treatment, which is not preferable. The alumina powder for use as a raw material for producing a single crystal of the present invention can be used in various production methods for producing a single crystal, for example, in Bernoulli method, crystal pulling method, zone melting method and the like. Among them, the Bernoulli method can be preferably applied. This alumina powder is preferably used for the production of alumina single crystals, but if it can be used to produce single crystals of other compositions, it can also be used for the production of those single crystals.
【００１０】このアルミナ粉末の粒径は、単結晶製造時
に溶融し得る程度の範囲にあればよく、特に限定されな
いが、通常一次粒子で約１μｍ以下、より好ましくは約
０．５μｍ以下がよく、これをそのまま使用したり、或
いは造粒して使用する。このような単結晶原料用アルミ
ナ粉末の製造方法としては、基本的にはＮａ，Ｓｉ，Ｍ
ｇ，Ｆｅの不純物の含有量のなるべく少ないアルミナま
たはアルミニウム化合物にＣａ分、必要によりＴｉ分を
加え、アルミニウム化合物の場合にはその後加水分解等
によりアルミナに変えるという方法が用いられ、具体的
には次のような方法を挙げることができる。 （１） 有機アルミニウム溶液にＣａ塩、Ｔｉ塩を添加
し、加水分解した後、必要に応じ乾燥し、焼成する方
法。 （２） アンモニウムミョウバンにＣａ塩、Ｔｉ塩を添
加し、これを熱分解する方法。 （３） バイヤー法により得られたアルミナを精製した
アルミナ粉末、有機アルミニウムの加水分解法やアンモ
ニウムミョウバン熱分解法により得られたアルミナ粉末
に、Ｃａ含有物、更に金属Ｔｉ又はＴｉ含有物を振動ミ
ルやボールミル等の乾式混合装置でＣａ、Ｔｉが均一に
分散するように混合する方法。 （４） アルミナスラリー中にＣａ塩、Ｔｉ塩を添加
し、湿式混合した後、通常の加熱乾燥或いはスプレード
ライ法等により乾燥する方法。The particle size of this alumina powder is not particularly limited as long as it can be melted during the production of a single crystal, and is usually about 1 μm or less, more preferably about 0.5 μm or less in terms of primary particles. This is used as it is, or granulated and used. Basically, a method for producing such alumina powder for a single crystal raw material is Na, Si, M.
A method is used in which Ca and Ti, if necessary, are added to alumina or an aluminum compound containing as little g and Fe impurities as possible, and then, in the case of an aluminum compound, it is changed to alumina by hydrolysis or the like. The following methods can be mentioned. (1) A method in which a Ca salt and a Ti salt are added to an organic aluminum solution, which is hydrolyzed, then dried if necessary, and baked. (2) A method of adding Ca salt and Ti salt to ammonium alum and thermally decomposing it. (3) An alumina powder obtained by purifying alumina obtained by the Bayer method, an alumina powder obtained by a hydrolysis method of organoaluminum or a thermal decomposition method of ammonium alum, and a Ca-containing substance, and further a metal-Ti or Ti-containing substance are vibrated by a vibration mill. A method of mixing with a dry mixing device such as a ball mill or the like so that Ca and Ti are uniformly dispersed. (4) A method in which a Ca salt and a Ti salt are added to an alumina slurry, the mixture is wet mixed, and then dried by a usual heat drying or spray drying method.
【００１１】これらにより得られるアルミナ粉末の結晶
形態も、通常単結晶原料用アルミナ粉末として公知の形
態であればよく、水酸化アルミニウムからθ，γ，δ，
σ等の遷移アルミナ、更にはα−アルミナ迄のいずれの
形態であってもよい。The crystal form of the alumina powder obtained from these may be any of the forms generally known as alumina powders for single crystal raw materials, such as θ, γ, δ from aluminum hydroxide.
It may be in any form up to transitional alumina such as σ, and further up to α-alumina.
【００１２】[0012]
【作用】本発明の単結晶製造原料用アルミナ粉末は、Ｎ
ａ，Ｓｉ，Ｍｇ，Ｆｅの不純物の含有量をなるべく少な
くし、かつＣａ分をＣａ原子として１〜５ｐｐｍ含有さ
せることにより、単結晶の製造において気泡、着色がな
く、かつＣ面の発現が抑えられた単結晶を得ることがで
きる。しかし、その作用機構は現在のところまだ解明さ
れていない。The function of the alumina powder for producing a single crystal of the present invention is N
By reducing the content of impurities of a, Si, Mg, Fe as much as possible, and by containing Ca content of 1 to 5 ppm as Ca atoms, there is no bubble or coloring in the production of a single crystal, and the development of the C plane is suppressed. The obtained single crystal can be obtained. However, its mechanism of action has not yet been elucidated.
【００１３】[0013]
【実施例】以下、実施例により本発明を具体的に説明す
るが、本発明はかかる実施例により制限されるものでは
ない。なお、以下にいう有効径率は、得られた単結晶プ
ールの最大径に対して、該プールより得られる最大径の
円柱の直径の割合を百分率で示したものであり、熱処理
時間短縮度は、比較例１で示すアルミア粉末より得られ
た単結晶プールの熱処理に必要とする時間に対して、各
々のアルミナ粉末から得られた単結晶プールの熱処理に
必要とする時間の割合を百分率で示したものである。 実施例１〜５ アルミニウムイソプロポキシドを蒸留精製し、加水分解
した後焼成して得られた、不純物としてＮａ ２ｐｐ
ｍ，Ｓｉ ２ｐｐｍ，Ｍｇ １ｐｐｍ，及びＦｅ１ｐｐ
ｍを含有するγ−アルミナに対して、Ｃａ及びＴｉとし
て第１表に示す量のＣａ（ＯＨ）2 及びＴｉ（ＳＯ4 ）
2 の水溶液を混合し、スラリー状とした後、スプレード
ライヤーで乾燥した。このようにして得られたアルミナ
粉末をベルヌーイ法単結晶製造装置で単結晶に結晶成長
させ、得られた単結晶プールの気泡、円柱として切りだ
せる有効径、色及び熱処理に必要とする時間を測定し
た。EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the examples. The effective diameter ratio described below is a ratio of the diameter of the cylinder having the maximum diameter obtained from the pool to the maximum diameter of the obtained single crystal pool, which is shown as a percentage. Shows the percentage of the time required for the heat treatment of the single crystal pool obtained from each alumina powder with respect to the time required for the heat treatment of the single crystal pool obtained from the aluminum powder shown in Comparative Example 1. It is a thing. Examples 1 to 5 Na 2pp as an impurity obtained by distilling and refining aluminum isopropoxide, hydrolyzing it, and then firing it.
m, Si 2 ppm, Mg 1 ppm, and Fe 1 pp
With respect to γ-alumina containing m, the amounts of Ca (OH) 2 and Ti (SO 4 ) shown in Table 1 as Ca and Ti.
The aqueous solutions of 2 were mixed to form a slurry and then dried with a spray dryer. The alumina powder thus obtained was grown into a single crystal with a Bernoulli method single crystal manufacturing apparatus, and the bubbles of the obtained single crystal pool, the effective diameter for cutting out as a cylinder, the color, and the time required for heat treatment were measured. did.
【００１４】その結果を第１表に示す。The results are shown in Table 1.
【００１５】[0015]
【表１】 [Table 1]
【００１６】比較例１〜８ 第２表に示す不純物を含有するγ−アルミナに対して、
第２表に示す量のＣａ（ＯＨ）2 及びＴｉ（ＳＯ4 ）2
の水溶液を混合しスラリー状とした後、スプレードライ
ヤーで乾燥した。このようにして得られたアルミナ粉末
をベルヌーイ法単結晶製造装置で結晶成長させ、得られ
たプールの気泡、円柱として切りだせる有効径、色及び
熱処理に必要とする時間を測定した。Comparative Examples 1 to 8 For γ-alumina containing impurities shown in Table 2,
The amounts of Ca (OH) 2 and Ti (SO 4 ) 2 shown in Table 2
The resulting aqueous solution was mixed to form a slurry and then dried with a spray dryer. The alumina powder thus obtained was subjected to crystal growth with a Bernoulli method single crystal manufacturing apparatus, and the bubbles of the pool obtained, the effective diameter for cutting out as a cylinder, the color, and the time required for heat treatment were measured.
【００１７】その結果を第２表に示す。The results are shown in Table 2.
【００１８】[0018]
【表２】 [Table 2]
【００１９】第２表からわかるように、従来技術である
比較例２の単結晶プールは有効径率が低く、この有効径
率を上げるためＴｉを１０〜２０ｐｐｍ添加した改良技
術である比較例１、３は、有効径率は上昇するが熱処理
時間が比較例２よりも増加する。また、Ｃａを添加して
も、本発明の範囲を越えた量である比較例４は、熱処理
時間などが改善されるが、気泡を含有してしまう。ま
た、不純物が多いものはＣａを所定量含有しても気泡を
含むものとなる。これに対して、本発明では第１表にみ
るように、有効径率が高く、気泡を含まず、熱処理時間
が短縮される。As can be seen from Table 2, the single crystal pool of Comparative Example 2 which is a conventional technique has a low effective diameter ratio and Comparative Example 1 which is an improved technique in which 10 to 20 ppm of Ti is added to increase the effective diameter ratio. In No. 3, the effective diameter ratio increases, but the heat treatment time increases as compared with Comparative Example 2. Further, even if Ca is added, Comparative Example 4 in which the amount exceeds the range of the present invention improves the heat treatment time and the like, but contains bubbles. In addition, even if a large amount of impurities is contained in a material containing a large amount of impurities, it still contains bubbles. On the other hand, in the present invention, as shown in Table 1, the effective diameter ratio is high, no bubbles are contained, and the heat treatment time is shortened.
【００２０】[0020]
【発明の効果】本発明によれば、このアルミナ粉末を用
いて単結晶を製造したとき、得られる単結晶に気泡、着
色がなく、Ｃ面の発現が抑制されて、有効径率の高い円
柱状のもので、かつ短時間の熱処理により紫外線に不活
性とすることができる単結晶が得られるので、研磨コス
ト、熱処理コストの低減並びに製品の収率向上がなさ
れ、その工業的価値が非常に大きい。According to the present invention, when a single crystal is produced using this alumina powder, the obtained single crystal is free from bubbles and coloring, and the development of the C plane is suppressed, resulting in a circle having a high effective diameter ratio. Since a single crystal that is columnar and can be made inert to ultraviolet rays by heat treatment for a short time is obtained, polishing cost, heat treatment cost is reduced and product yield is improved, and its industrial value is extremely high. large.
Claims (1)
これら金属の化合物を、Ｎａ，Ｓｉ，Ｍｇ及びＦｅ原子
として各々２０ｐｐｍ以下、Ｃａ金属或いは該金属の化
合物をＣａ原子として１〜５ｐｐｍ含有することを特徴
とする単結晶製造原料用アルミナ粉末。1. A metal of Na, Si, Mg and Fe or a compound of these metals is contained in an amount of 20 ppm or less as Na, Si, Mg and Fe atoms, respectively, and a Ca metal or a compound of the metal is contained as 1 to 5 ppm as Ca atoms. Alumina powder for use as a raw material for producing a single crystal, characterized in that
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4121133A JPH05294615A (en) | 1992-04-16 | 1992-04-16 | Alumina powder for single crystal production raw material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4121133A JPH05294615A (en) | 1992-04-16 | 1992-04-16 | Alumina powder for single crystal production raw material |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05294615A true JPH05294615A (en) | 1993-11-09 |
Family
ID=14803695
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4121133A Pending JPH05294615A (en) | 1992-04-16 | 1992-04-16 | Alumina powder for single crystal production raw material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05294615A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013245149A (en) * | 2012-05-28 | 2013-12-09 | Sumitomo Chemical Co Ltd | Raw material alumina for producing sapphire single crystal and method for producing the sapphire single crystal |
-
1992
- 1992-04-16 JP JP4121133A patent/JPH05294615A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013245149A (en) * | 2012-05-28 | 2013-12-09 | Sumitomo Chemical Co Ltd | Raw material alumina for producing sapphire single crystal and method for producing the sapphire single crystal |
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