JP2001158620A - Rare earth-aluminum-garnet fine powder, method for producing the same and sintered compact using the same powder - Google Patents
Rare earth-aluminum-garnet fine powder, method for producing the same and sintered compact using the same powderInfo
- Publication number
- JP2001158620A JP2001158620A JP2000279866A JP2000279866A JP2001158620A JP 2001158620 A JP2001158620 A JP 2001158620A JP 2000279866 A JP2000279866 A JP 2000279866A JP 2000279866 A JP2000279866 A JP 2000279866A JP 2001158620 A JP2001158620 A JP 2001158620A
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- Prior art keywords
- rare earth
- aluminum
- fine powder
- garnet
- particle size
- Prior art date
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Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、分散性、充填性、
焼結性に優れ、焼結体合成用原料として有用な希土類・
アルミニウム・ガーネット微粉末およびその製造方法に
関する。[0001] The present invention relates to dispersibility, filling properties,
Rare earths with excellent sinterability and useful as raw materials for synthesis of sintered compacts
The present invention relates to an aluminum garnet fine powder and a method for producing the same.
【０００２】[0002]
【従来の技術】希土類・アルミニウム・ガーネット粉末
は、透光性セラミックス原料として用いられるほか、他
のセラミックス粉体と混合して焼結体の焼結助剤として
用いられている。これら粉末の製造方法としては、イッ
トリアとアルミナの混合粉をか焼する方法（固体混合
法）や、イットリウムとアルミニウムの鉱酸塩の水溶液
から得られた沈殿をか焼する方法（液相法）が報告され
ている。2. Description of the Related Art Rare earth / aluminum / garnet powder is used as a raw material for translucent ceramics, and is also used as a sintering aid for a sintered body by mixing with other ceramic powders. As a method for producing these powders, a method of calcining a mixed powder of yttria and alumina (solid mixing method) and a method of calcining a precipitate obtained from an aqueous solution of a salt of yttrium and aluminum mineral (liquid phase method) Have been reported.
【０００３】イットリアとアルミナを固体混合の後、こ
れをか焼する方法では、得られる粉体の粒径が大きいも
のとなり、ガーネット相へと相を変化させるためには、
液相法によって得られた粉体よりも高温でか焼する必要
がある。このため、結晶成長が促進されて結晶子が大き
くなり、粒径も大きくなりやすく、比表面積も小さくな
る。この方法による粉末は焼結性が低く、緻密な焼結体
を得にくい。ボールミル等の機械的粉砕により粒径を小
さくしても、元々の結晶子が大きいので焼結性はあまり
向上せず、ボールの破片等の混入等によって純度が低下
する弊害が生ずる場合がある。In a method in which yttria and alumina are mixed and then calcined, the resulting powder has a large particle size. In order to change the phase to a garnet phase,
It needs to be calcined at a higher temperature than the powder obtained by the liquid phase method. For this reason, crystal growth is promoted, crystallites are increased, the grain size is easily increased, and the specific surface area is also reduced. Powder obtained by this method has low sinterability and it is difficult to obtain a dense sintered body. Even if the particle size is reduced by mechanical pulverization with a ball mill or the like, the original crystallites are large, so that the sinterability is not so much improved, and there may be a case where the purity is reduced due to mixing of ball fragments and the like.
【０００４】イットリウム、アルミニウムの鉱酸塩の水
溶液より共沈させる方法では、粒径を小さくするため
に、沈殿生成時の溶液の濃度を薄くする必要があり、生
産性が高くない。さらに、か焼の際に粒子が成長して比
表面積が小さくなり、焼結性も高くならない。したがっ
て、従来の粉末は粒径が大きく、不揃いで焼結性が良く
ないために、焼結体の密度を高くするためには、ＨＩＰ
やホットプレスなどの処理が必要となり、高価な設備が
必要で、生産性も高くなかった。また、粒度分布に幅が
あって、他の粉体への分散性も不十分であった。粉砕に
よる場合には、不純物の混入等の問題もあった。In the method of coprecipitation from an aqueous solution of a salt of yttrium or aluminum, it is necessary to reduce the concentration of the solution at the time of precipitation, in order to reduce the particle size, and the productivity is not high. Furthermore, particles grow during calcination, the specific surface area decreases, and the sinterability does not increase. Therefore, the conventional powder has a large particle size, is irregular and has poor sinterability.
And hot press, etc., expensive equipment was required, and productivity was not high. Further, the particle size distribution was wide and the dispersibility in other powders was insufficient. In the case of pulverization, there is a problem such as mixing of impurities.
【０００５】[0005]
【発明が解決しようとする課題】本発明は、このような
欠点を解決しようとするもので、焼結性、分散性に優
れ、粒度のそろった希土類・アルミニウム・ガーネット
微粉末を提供することを課題とする。An object of the present invention is to solve the above-mentioned drawbacks and to provide a rare earth, aluminum and garnet fine powder having excellent sinterability and dispersibility and uniform particle size. Make it an issue.
【０００６】[0006]
【課題を解決するための手段】本発明の希土類・アルミ
ニウム・ガーネット微粉末は、比表面積が３．５ｍ2／
ｇ以上で、平均粒径Ｄ50が１．８μｍ以下、粒度分布の
９０％粒径（Ｄ90）と１０％粒径（Ｄ10）との差が１
０．０μｍ以下である。一次粒子の形は丸みを帯びた粒
子で、これらが単独もしくは２個以上連なった形状から
なる粒子である。結晶子の大きさが６００Å以下である
ことが好ましい。また、本発明は、Ｒ3Ａｌ5Ｏ12の組成
式で表される希土類・アルミニウム・ガーネットであっ
て、ＲがＡ1-XＢXの組成からなり、ＡはＹ、Ｄｙ、Ｈ
ｏ、Ｅｒ、Ｔｍ、Ｙｂ、Ｌｕから選択された一種又は二
種以上、ＢはＹを含む希土類元素から選択された一種ま
たは二種以上、但し、ＡとＢとは相互に同一のものを含
まない、Ｘは原子比を表し０〜０．２であることを特徴
とする。さらに、Ｍｇ、Ｓｉ、Ｃａの化合物のうち少な
くとも１種以上を合計で１０〜１００００ｐｐｍ含有す
る希土類・アルミニウム・ガーネット微粉末であること
が好ましい。また、本発明は、上記希土類・アルミニウ
ム・ガーネット微粉末を用いた焼結体である。比表面積
が２０〜３００ｍ2／ｇのアルミナを希土類鉱酸塩水溶
液に懸濁させ、沈殿剤を加えて希土類元素をアルミナ表
面にコーティングし、濾過、洗浄後、焼成することによ
り、希土類・アルミニウム・ガーネット微粉末を製造す
る。The rare earth / aluminum / garnet fine powder of the present invention has a specific surface area of 3.5 m 2 /
g, the average particle size D 50 is 1.8 μm or less, and the difference between the 90% particle size (D 90 ) and the 10% particle size (D 10 ) in the particle size distribution is 1
0.0 μm or less. The shape of the primary particles is a rounded particle, and is a particle having a shape of a single particle or a combination of two or more particles. It is preferable that the crystallite size is not more than 600 °. Further, the present invention provides a rare earth aluminum garnet expressed by the composition formula of R 3 Al 5 O 12, R is the composition of A 1-X B X, A is Y, Dy, H
one or more selected from o, Er, Tm, Yb, Lu; B is one or more selected from rare earth elements including Y, provided that A and B include the same as each other X is an atomic ratio and is 0 to 0.2. Further, it is preferable that the rare earth / aluminum / garnet fine powder contains at least one compound of Mg, Si and Ca in total of 10 to 10000 ppm. Further, the present invention is a sintered body using the rare earth / aluminum / garnet fine powder. Alumina having a specific surface area of 20 to 300 m 2 / g is suspended in an aqueous solution of a rare earth mineral, and a precipitant is added to coat the surface of the alumina with a rare earth element. Produce garnet fine powder.
【０００７】[0007]
【発明の実施の形態】本発明者は、一次粒子の形状を丸
くし、粒径を小さく、粒度分布をシャープにすることで
分散性、充填性を向上させ、比表面積が大きくなり、結
晶子を小さくすることで焼結活性を高めることができ、
そのような粉体を用いることにより、温和な条件で焼結
させる事ができることを見出した。即ち、本発明のガー
ネット微粉末は、形状が丸みを帯びており、結晶子はＸ
線回折法によって測定したデータをWilson法によって解
析され、結晶子の大きさが６００Å以下、平均粒径が
１．８μｍ以下で、比表面積が３．５ｍ2／ｇ以上であ
るとともに、粒度分布の９０％粒径（Ｄ90）と１０％粒
径（Ｄ10）との差が１０．０μｍ以下であって粒径がそ
ろっており、充填性に優れ、表面エネルギーが大きいた
めに焼結活性が高い。ここで、丸みを帯びた形状とは、
構成粒子が円もしくは楕円の複合形状からなり、頂点を
有する角がないことを意味するものである。BEST MODE FOR CARRYING OUT THE INVENTION The present inventors have proposed that the shape of primary particles is rounded, the particle size is small, the particle size distribution is sharp, the dispersibility and packing property are improved, the specific surface area is large, and the crystallites are large. Sintering activity can be increased by reducing
It has been found that sintering can be performed under mild conditions by using such a powder. That is, the garnet fine powder of the present invention has a round shape, and the crystallite has X
The data measured by the line diffraction method was analyzed by the Wilson method, and the crystallite size was 600 ° or less, the average particle size was 1.8 μm or less, the specific surface area was 3.5 m 2 / g or more, and the particle size distribution was The difference between the 90% particle size (D 90 ) and the 10% particle size (D 10 ) is 10.0 μm or less, the particle sizes are uniform, the packing property is excellent, and the surface energy is large, so the sintering activity is low. high. Here, the rounded shape means
This means that the constituent particles have a composite shape of a circle or an ellipse and have no corner having a vertex.
【０００８】緻密な焼結体を作る場合、その焼結前の成
形体の密度を大きくする必要があるが、密度の大きい成
形体を得るには、一般的に、粒度が小さく、かつ粒度分
布の幅の狭い粉末が必要である。平均粒径Ｄ50を１．８
μｍ以下とするのは、平均粒径がこれ以上大きいと充填
性が悪く、隙間の大きいものとなるからである。平均粒
径が小さくなると粒子の凝集により充填性が悪くなる。
好ましくは０．２〜１．８μｍの範囲である。粒子は単
独で独立していることが好ましいが、図１に示す程度に
連なっていても、すなわち、粒子の接触点における形態
が亜鈴状のくびれ部分を有していれば、短時間のボール
ミル等による粉砕処理によって容易に分割し得るので、
特に問題とはならない。When a dense sintered body is to be produced, it is necessary to increase the density of the compact before sintering. However, to obtain a compact having a high density, the compact generally has a small particle size and a small particle size distribution. A narrow powder is required. The average particle diameter D 50 1.8
The reason why the particle size is set to be not more than μm is that if the average particle size is larger than this, the filling property is poor and the gap is large. When the average particle diameter is small, the packing property is deteriorated due to aggregation of the particles.
Preferably, it is in the range of 0.2 to 1.8 μm. It is preferable that the particles are independent and independent. However, even if the particles are connected as shown in FIG. 1, that is, if the shape at the contact point of the particles has a dumbbell-shaped constriction, a short-time ball mill or the like can be used. Can be easily divided by the crushing process,
There is no particular problem.
【０００９】粒度分布の９０％粒径（Ｄ90）と１０％粒
径（Ｄ10）との差が１０．０μｍ以下とするのは、粒度
分布に幅があると充填に斑ができて、充填度が悪く、隙
間の多い成形体となるからである。一般に、ガーネット
相を得るためにか焼した後の粉末は、高温履歴を有する
ため、比表面積が小さくなり、それによって表面エネル
ギーが小さくなり、焼結性が悪くなる。比表面積を３．
５ｍ2／ｇ以上とするのは、比表面積がこれより小さい
と表面エネルギーが小さく、焼結性が極度に低下するか
らである。比表面積が大きくなると、嵩密度が小さくな
って成形が困難となるので、好ましくは３．５〜２５ｍ
2／ｇの範囲とするとよい。The reason why the difference between the 90% particle size (D 90 ) and the 10% particle size (D 10 ) of the particle size distribution is 10.0 μm or less is that if the particle size distribution has a wide range, the packing becomes uneven, This is because the molded body has a poor filling degree and has many gaps. Generally, the powder after calcining to obtain a garnet phase has a high temperature history, so that the specific surface area is reduced, thereby reducing the surface energy and deteriorating the sinterability. 2. Specific surface area
The reason why the specific surface area is 5 m 2 / g or more is that if the specific surface area is smaller than this, the surface energy is small and the sinterability is extremely reduced. When the specific surface area is large, the bulk density becomes small and molding becomes difficult.
It is better to be in the range of 2 / g.
【００１０】機械的粉砕によって粒径を小さくし、比表
面積を大きくすることもできるが、その際には結晶内に
ひずみが生じ、焼結性を低下させる原因となり、あまり
好ましくはない。また、ボールミルによる処理時にはボ
ール破片の混入があるなど、このような機械的処理では
不純物混入による純度低下の原因ともなる。微粒子を構
成する結晶子の大きさは、６００Å以下であることが望
ましい。結晶子の大きさを６００Å以下とするのは、こ
れより大きいと焼結性が低下するほか、結晶に歪がな
く、分散性の良い、粒径の小さい粉末を得るのが困難に
なるからである。結晶子の大きさは、原料となるアルミ
ナの結晶子の大きさ、沈殿の形状、粒子径、か焼温度に
より、調整することができる。[0010] The particle size can be reduced and the specific surface area can be increased by mechanical pulverization. However, in that case, distortion occurs in the crystal, which causes a reduction in sinterability, which is not preferred. In addition, such mechanical treatment may cause a decrease in purity due to the contamination of impurities, for example, there is mixing of ball fragments at the time of treatment by a ball mill. The size of the crystallites constituting the fine particles is desirably 600 ° or less. The reason why the crystallite size is set to 600 ° or less is that if the size is larger than this, the sinterability is reduced, and it is difficult to obtain a powder having a small particle size without distortion in the crystal, good dispersibility. is there. The size of the crystallite can be adjusted by the size of the crystallite of alumina as a raw material, the shape of the precipitate, the particle diameter, and the calcination temperature.
【００１１】微粒子（一次粒子）は、微細な単結晶（結
晶子）の集合によって構成される粒子で、形状として
は、プレス成形などにより緻密な成形体を得るために、
表面に角のない丸みをもった構造、球状又は擬球状が好
ましい。微粒子表面に角があると充填の際に粒子間の角
が引っ掛かって、滑りが悪くなるためである。微粒子の
形状は、当初の核になるアルミナの形状で基本的に規定
される。希土類・アルミニウム・ガーネットを生成する
希土類元素としては、Ｙ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙ
ｂ、Ｌｕがあり、これら希土類の一種もしくは二種以上
の混合物であればガーネット相が安定相として存在す
る。しかし、これらの元素の一部を他の３Ａ族元素（Ｙ
を含む希土類元素）で少量置換してもガーネット相が得
られる。置換する３Ａ族元素の置換度は、ガーネットを
生成する上記の希土類元素の２０モル％以下とする。こ
れ以上置換度を大きくすると、ガーネット相を生成する
ことができなくなる。なお、請求項４におけるＡ1-XＢX
において、Ａ・Ｂが二種以上である場合には、合計量で
Ｘないし１−Ｘを考える。Fine particles (primary particles) are particles composed of a collection of fine single crystals (crystallites).
Preference is given to a rounded structure with no corners on the surface, spherical or pseudospherical. This is because if there are corners on the surface of the fine particles, the corners between the particles are caught at the time of filling, and the sliding becomes poor. The shape of the fine particles is basically defined by the shape of the alumina which initially becomes the core. Rare earth elements that form rare earth, aluminum, and garnet include Y, Dy, Ho, Er, Tm, and Y.
b, Lu, and if one or a mixture of two or more of these rare earths, a garnet phase exists as a stable phase. However, some of these elements are replaced with other Group 3A elements (Y
A garnet phase can be obtained even when a small amount of garnet is replaced with a rare earth element containing The substitution degree of the group 3A element to be substituted is 20 mol% or less of the above-mentioned rare earth element that forms garnet. If the substitution degree is further increased, a garnet phase cannot be generated. It should be noted that A 1-X B X in claim 4
In the case where A and B are two or more, X to 1-X are considered in total.
【００１２】本発明による微粉末は、以下の方法によっ
て製造される。用いるアルミナ、希土類塩を上記組成に
なるように配合し、まず、希土類鉱酸塩水溶液にアルミ
ナを懸濁させる。アルミナの結晶相は問わないが、好ま
しくは、粒子径が小さく、比表面積の大きいガンマアル
ミナを用いる。硝酸塩、塩酸塩等の希土類鉱酸塩水溶液
にアルミナを懸濁させた溶液に、希土類に対する沈殿剤
を加え、アルミナに希土類のコーティングを形成させ
る。沈殿剤としては、Ｒ（Ｙを含む希土類元素）と反応
して水に不溶性の沈殿を生成する沈殿剤、例えばアンモ
ニア、炭酸アンモニウム、炭酸水素アンモニウム、蓚
酸、尿素、であれば良く、好ましくは尿素の分解を利用
した均一沈殿法を行なう。尿素の分解を利用した均一沈
殿法は、尿素をＲのモル数の６〜２０倍量、好ましくは
８〜１６倍量用い、７０〜１００℃×２〜１２時間、好
ましくは８０〜１００℃×２〜６時間、加熱して行う。
生じた希土類アルミニウム複合酸化物の沈殿を濾過、洗
浄した後、８００〜１５００℃×１〜８時間、好ましく
は１０００〜１４５０℃×２〜６時間で焼成（か焼）す
ることによって、単一相からなるガーネット構造を有す
る微粉末を得ることができる。得られる希土類アルミニ
ウム複合酸化物の粒度、また、か焼して得られる本発明
のガーネット微粉末の粒度は、粒度分布と共に、用いる
アルミナの粒度および粒度分布に大きく依存する。ま
た、結晶子の大きさは、高温に曝すほど大きくなるの
で、ガーネット相前駆体の複合酸化物の粒径が小さいこ
と、結晶子が成長しにくい構造であることが重要であ
る。The fine powder according to the present invention is produced by the following method. Alumina and rare earth salts to be used are blended so as to have the above-mentioned composition, and alumina is first suspended in a rare earth mineral salt aqueous solution. The crystal phase of alumina is not limited, but gamma alumina having a small particle size and a large specific surface area is preferably used. A precipitant for the rare earth is added to a solution in which the alumina is suspended in an aqueous solution of a rare earth mineral such as nitrate or hydrochloride to form a rare earth coating on the alumina. The precipitant may be any precipitant that reacts with R (a rare earth element including Y) to form a water-insoluble precipitate, such as ammonia, ammonium carbonate, ammonium hydrogen carbonate, oxalic acid, and urea. A homogeneous precipitation method utilizing the decomposition of is carried out. The homogeneous precipitation method using the decomposition of urea uses urea in an amount of 6 to 20 times, preferably 8 to 16 times, the number of moles of R, and 70 to 100 ° C for 2 to 12 hours, preferably 80 to 100 ° C × Perform by heating for 2-6 hours.
The resulting precipitate of the rare earth aluminum composite oxide is filtered and washed, and then fired (calcined) at 800 to 1500 ° C for 1 to 8 hours, preferably at 1000 to 1450 ° C for 2 to 6 hours to obtain a single phase. A fine powder having a garnet structure can be obtained. The particle size of the obtained rare earth aluminum composite oxide and the particle size of the garnet fine powder of the present invention obtained by calcination largely depend on the particle size distribution and the particle size of alumina used together with the particle size distribution. Further, since the size of the crystallite increases as the temperature is increased, it is important that the composite oxide of the garnet phase precursor has a small particle size and a structure in which the crystallite does not easily grow.
【００１３】したがって、アルミナとしては、比表面積
が２０ｍ2/g以上で、粒度分布がシャープであるものを
用いるのが好ましく、さらには、沈殿生成後の濾過のし
やすさから、比表面積は３００ｍ2/g以下であることが
好ましい。懸濁させるアルミナ粒子は、もともと結晶子
の小さい微粒子であり、沈殿剤を加えた後に希土類のコ
ーティングが施されている。この方法によって得られた
ガーネット組成の沈殿は、か焼の際に微小なアルミナを
骨格として粒子が成長するために、粒子の凝集が妨げら
れ、単一相にすべく高温でか焼しても、比表面積が大き
く、成形後の焼結を容易にするのに重要な表面エネルギ
ーを大きく保つことができる。Therefore, it is preferable to use alumina having a specific surface area of not less than 20 m 2 / g and a sharp particle size distribution. Further, the specific surface area is preferably 300 m 2 / g because of easy filtration after precipitation. It is preferably 2 / g or less. The alumina particles to be suspended are originally fine particles having small crystallites, and are coated with a rare earth element after adding a precipitant. Precipitation of the garnet composition obtained by this method, during the calcination, because the particles grow with fine alumina as a skeleton, aggregation of the particles is prevented, and even if calcined at a high temperature to form a single phase, A large specific surface area, and a large surface energy important for facilitating sintering after molding can be maintained.
【００１４】本発明においては、該微粒子を焼結するの
に、Ｍｇ、Ｓｉ、Ｃａの化合物が助剤として有効に作用
する。助剤を含有させる場合、沈殿を生成せしめる工程
からか焼する工程の前までに助剤を導入し、か焼するこ
とにより、粉体粒子に助剤を含有、拡散させることがで
きる。添加時の形態としては、酸化物、ハロゲン化物
（フッ化物、塩化物）や、硝酸塩、酢酸塩などの塩等が
挙げられる。それらの添加方法としては、ボールミル等
によってか焼用の原料粉末と混合させる方法と、沈殿用
の溶液に添加して、当初より粉末に含有させておく方法
がある。In the present invention, a compound of Mg, Si, and Ca effectively acts as an auxiliary in sintering the fine particles. When an auxiliary agent is contained, the auxiliary agent is introduced into the powder particles by introducing the auxiliary agent from the step of forming a precipitate to before the step of calcining, and then calcining, so that the powder particles can contain and diffuse the auxiliary agent. Examples of the form at the time of addition include oxides, halides (fluorides and chlorides), and salts such as nitrates and acetates. As a method of adding them, there are a method of mixing with a raw material powder for calcination by a ball mill or the like, and a method of adding to a solution for precipitation to be contained in the powder from the beginning.
【００１５】ボールミル等によって混合する方法では、
比重差、凝集性の違いなどにより、均一に混合するのが
困難となる場合があり、混合に数時間を要する場合があ
る。一方、当初より粉末に含有されている場合、その粉
末を焼結させるだけでよく、作業性が向上する利点があ
る。助剤の添加量は、１０〜１００００ｐｐｍ、好まし
くは５０〜５０００ｐｐｍの範囲で微粉末に導入するこ
とが好ましい。この添加量の数値を外れると、少ない場
合には該助剤が全体に分布せず効果が薄れる傾向が顕著
になり、多い場合には目的とする相以外の化合物を生成
させることがあるので、共に好ましくない。さらに、本
発明では、上記希土類・アルミニウム・ガーネット微粉
末を成形加工し、焼結して焼結体を得ることができる。
焼結温度は、所望の焼結体となるように温度と時間を選
ぶが、例えば１５００〜１８５０℃×２〜１０時間、好
ましくは１６００〜１８００℃×２〜６時間で焼結させ
るとよい。In the method of mixing with a ball mill or the like,
Due to differences in specific gravity, differences in cohesiveness, etc., it may be difficult to mix uniformly, and it may take several hours to mix. On the other hand, when it is contained in the powder from the beginning, it is only necessary to sinter the powder, and there is an advantage that workability is improved. It is preferable to introduce the auxiliary agent into the fine powder in the range of 10 to 10000 ppm, preferably 50 to 5000 ppm. If the addition amount is out of the range, when the amount is small, the auxiliary tends not to be distributed throughout and the effect tends to be weakened.When the amount is large, a compound other than the intended phase may be formed. Both are not preferred. Further, in the present invention, the above-mentioned rare earth / aluminum / garnet fine powder can be molded and sintered to obtain a sintered body.
The sintering temperature is selected so as to obtain a desired sintered body. For example, the sintering may be performed at 1500 to 1850 ° C. × 2 to 10 hours, preferably 1600 to 1800 ° C. × 2 to 6 hours.
【００１６】[0016]
【実施例】以下、本発明の実施例を説明する。 ［実施例１］純度９９．９９％、比表面積１４５ｍ2／
ｇであるガンマアルミナ２５．５ｇ（０．２５モル）
を、純度９９．９９％の０．０３モル／リットルの硝酸
イットリウム溶液１０リットルに懸濁した。これに尿素
１４４ｇを加えて、８０℃×１２０分に加熱することに
より、アルミナ表面にイットリウム塩基性炭酸塩が付着
した沈殿を得た。これを濾過、洗浄し、乾燥させた後、
１２５０℃×６時間大気雰囲気中でか焼して５６．５ｇ
のイットリウム・アルミニウム・ガーネット（ＹＡＧ）
粉末を得た。Embodiments of the present invention will be described below. Example 1 Purity 99.99%, specific surface area 145 m 2 /
g of gamma alumina 25.5 g (0.25 mol)
Was suspended in 10 l of a 0.03 mol / l yttrium nitrate solution having a purity of 99.99%. 144 g of urea was added thereto, and the mixture was heated at 80 ° C. for 120 minutes to obtain a precipitate having yttrium basic carbonate adhered to the alumina surface. After filtering, washing and drying this,
56.5 g after calcination in air atmosphere at 1250 ° C for 6 hours
Yttrium Aluminum Garnet (YAG)
A powder was obtained.
【００１７】この粉末は、日機装（株）製マイクロトラ
ックＳＰＡ型（商品名）を用いて測定したところ、表１
に示す粒度分布を持ち、比表面積は５．１ｍ2／ｇであ
った。また、一次粒子は、図１の顕微鏡写真で示すとお
り、角のない丸みを帯びた形状をしていた。Ｘ線回折法
によって測定したところ、ＹＡＧ単相であることが分か
った。Wilson法を用いて結晶子の大きさを計算したとこ
ろ、５４６Åであった。比表面積は、（株）島津製作所
製フローソーブ２３００型（商品名）を用いて測定し
た。なお、以下に述べる実施例・比較例における粒子の
性状を併せて表１に示す。The powder was measured using a Microtrac SPA (trade name) manufactured by Nikkiso Co., Ltd.
And the specific surface area was 5.1 m 2 / g. The primary particles had a rounded shape with no corners, as shown in the micrograph of FIG. When measured by the X-ray diffraction method, it was found to be a YAG single phase. The crystallite size calculated using the Wilson method was 546 °. The specific surface area was measured using Flowsorb 2300 (trade name) manufactured by Shimadzu Corporation. Table 1 also shows the properties of the particles in Examples and Comparative Examples described below.
【００１８】[0018]
【表１】 [Table 1]
【００１９】この粉体に水溶性セルロースエーテル（信
越化学工業（株）製品名：メトローズ）を１重量％混合
し、９８．０７ＭＰａ（１０００ｋｇｆ／ｃｍ2）の圧
力で金型プレスによって成形体を作成し、大気雰囲気で
１６５０℃×２時間の条件で焼結させたところ、ＹＡＧ
の理論密度４．５５ｇ／ｃｍ2の９９．４％まで焼結し
ており、透光性を有していた。1% by weight of a water-soluble cellulose ether (Shin-Etsu Chemical Co., Ltd. product name: Metroose) was mixed with the powder, and a molded product was formed by a die press under a pressure of 98.07 MPa (1000 kgf / cm 2 ). After sintering at 1650 ° C. for 2 hours in an air atmosphere,
Was sintered to 99.4% of the theoretical density of 4.55 g / cm 2 , and had translucency.
【００２０】［実施例２］希土類としてＹｂを用いるほ
かは、実施例１と同様にして、Ｙｂ：Ａｌ＝３：５（モ
ル比）となる沈殿を合成し、イッテルビウム・アルミニ
ウム・ガーネットを製造した。焼結性（焼結密度）にお
いても実施例１のＹＡＧと同等の結果が得られた。[Example 2] A precipitate of Yb: Al = 3: 5 (molar ratio) was synthesized in the same manner as in Example 1 except that Yb was used as a rare earth element to produce ytterbium aluminum garnet. . With respect to the sinterability (sintering density), a result equivalent to that of YAG of Example 1 was obtained.
【００２１】［実施例３］希土類としてＥｒを用いるほ
かは、実施例１と同様にして、Ｅｒ：Ａｌ＝３：５（モ
ル比）となる沈殿を合成し、エルビウム・アルミニウム
・ガーネットを製造した。焼結性においても実施例１の
ＹＡＧと同等の結果が得られた。[Example 3] A precipitate having Er: Al = 3: 5 (molar ratio) was synthesized in the same manner as in Example 1 except that Er was used as a rare earth element to produce erbium aluminum garnet. . In terms of sinterability, a result equivalent to that of YAG of Example 1 was obtained.
【００２２】［実施例４］希土類としてＹおよびＮｄを
Ｙ：Ｎｄ＝１４：１（モル比）、Ａ＝Ｙ、Ｂ＝Ｎｄ、３
Ｘ＝０．２となるように用いるほかは、実施例１と同様
にしＹ2.8Ｎｄ0.2Ａｌ5Ｏ12の組成式で表される、ネオ
ジムをドープしたイットリウム・アルミニウム・ガーネ
ットを製造した。焼結性においても実施例１のＹＡＧと
同等の結果が得られた。Example 4 Y: Nd = 14: 1 (molar ratio), A = Y, B = Nd, 3
A neodymium-doped yttrium aluminum garnet represented by a composition formula of Y 2.8 Nd 0.2 Al 5 O 12 was produced in the same manner as in Example 1 except that X was set to 0.2 . In terms of sinterability, a result equivalent to that of YAG of Example 1 was obtained.
【００２３】［実施例５］実施例１で得られたＹＡＧ粉
末に、か焼前に焼結助剤としてＣａＯを１００ｐｐｍ添
加した。この粉末を実施例１と同様にして焼結させたと
ころ、１６５０℃での焼結後の焼結体密度は、理論密度
の１００％に達した。Example 5 To the YAG powder obtained in Example 1, 100 ppm of CaO was added as a sintering aid before calcination. When this powder was sintered in the same manner as in Example 1, the sintered body density after sintering at 1650 ° C. reached 100% of the theoretical density.
【００２４】［比較例１］ＹＡＧ組成になるように、濃
度０．０６モル／リットルの硝酸イットリウム水溶液５
リットルと、濃度０．０５モル／リットルの硫酸アルミ
ニウム水溶液５リットルとを混合し、尿素３８４ｇを加
えて、８０℃×２時間加熱し、アルミニウムとイットリ
ウムの共沈殿物を生成させ、濾過、洗浄し、乾燥させた
後、１２５０℃大気雰囲気中でか焼して、イットリウム
・アルミニウム・ガーネット（ＹＡＧ）粉末を得た。こ
の粉末を実施例１の方法と同様に測定したところ、表１
のような物性であり、粒径が大きく、粒度分布の幅も大
きいことが分かった。また、一次粒子は、図２の顕微鏡
写真で示すとおり、角の多い形状をしていた。この粉体
に水溶性セルロースエーテル（前出）を１重量％混合
し、９８．０７ＭＰａ（１０００ｋｇｆ／ｃｍ2）の圧
力で金型プレスによって成形体を作製し、大気雰囲気で
１６５０℃の条件で焼結させたところ、ＹＡＧの理論密
度の８６．８％までしか焼結密度があがらなかった。Comparative Example 1 An aqueous solution of yttrium nitrate 5 having a concentration of 0.06 mol / liter so as to have a YAG composition was prepared.
Liters and 5 liters of an aqueous solution of aluminum sulfate having a concentration of 0.05 mol / l were mixed, 384 g of urea was added, and the mixture was heated at 80 ° C. for 2 hours to form a coprecipitate of aluminum and yttrium, which was filtered and washed. After drying, the powder was calcined in an air atmosphere at 1250 ° C. to obtain yttrium aluminum garnet (YAG) powder. This powder was measured in the same manner as in Example 1, and Table 1
It was found that the particle size was large and the width of the particle size distribution was large. In addition, the primary particles had a shape with many corners as shown in the micrograph of FIG. This powder was mixed with 1% by weight of a water-soluble cellulose ether (described above), and a molded article was prepared by a die press under a pressure of 98.07 MPa (1000 kgf / cm 2 ), and fired at 1650 ° C. in an air atmosphere. As a result, the sintered density was increased only up to 86.8% of the theoretical density of YAG.
【００２５】［比較例２］純度９９．９９％のアルミナ
（平均粒度０．３２μｍ、比表面積１２．１ｍ2／ｇ）
およびイットリア（平均粒度１．１μｍ、比表面積３
０．６ｍ2／ｇ）をＹＡＧ組成になるように合計１００
ｇ秤量し、１００ミリリットルのイソプロピルアルコー
ルを加え、２００ｇのアルミナボールを用いたボールミ
ルによって混合し、これを乾燥し、１５００℃でか焼し
た。粒度分布を測定したところ、非常に粒度のばらつき
が大きい粉末であることが分かった。Comparative Example 2 Alumina having a purity of 99.99% (average particle size 0.32 μm, specific surface area 12.1 m 2 / g)
And yttria (average particle size 1.1 μm, specific surface area 3
0.6 m 2 / g) to give a YAG composition for a total of 100
g was weighed, 100 ml of isopropyl alcohol was added, mixed by a ball mill using 200 g of alumina balls, dried and calcined at 1500 ° C. When the particle size distribution was measured, it was found that the powder had a very large variation in particle size.
【００２６】Ｘ線回折法によって測定したところ、ＹＡ
Ｇ相のほか、ペロブスカイト相および原料粉体の相が混
在しており、１５００℃まで温度を上げても、か焼が十
分でないことが分かった。また、Wilson法を用いて結晶
子の大きさを計算したところ、６５６Åであった。この
粉を実施例１と同様にして焼結させたところ、１６５０
℃での焼結後の焼結体密度は７６．８％までしかあがら
なかった。When measured by the X-ray diffraction method, YA
In addition to the G phase, the perovskite phase and the phase of the raw material powder were mixed, and it was found that calcination was not sufficient even when the temperature was increased to 1500 ° C. The crystallite size calculated using the Wilson method was 656 °. When this powder was sintered in the same manner as in Example 1, 1650 was obtained.
The sintered body density after sintering at 0 ° C. rose only to 76.8%.
【００２７】[0027]
【発明の効果】以上のように、本発明によれば、比表面
積が３．５ｍ2／ｇ以上で、平均粒径Ｄ50が１．８μｍ
以下であって、９０％粒径（Ｄ90）と１０％粒径
（Ｄ10）の差が１０．０μｍ以下であるような粒度分布
の狭い、一次粒子の形が丸みを帯びた希土類・アルミニ
ウム・ガーネット微粉末は、生産性が高く、充填性に優
れ、また単相であり、焼結活性が高い。そのため、この
希土類・アルミニウム・ガーネット微粉末を用いて成形
し、焼結すれば、温和な条件で焼結密度の高い焼結体を
得ることができる。As described above, according to the present invention, the specific surface area is 3.5 m 2 / g or more, and the average particle diameter D 50 is 1.8 μm.
A rare earth / aluminum having a narrow primary particle size and a round primary particle shape such that the difference between the 90% particle size (D 90 ) and the 10% particle size (D 10 ) is 10.0 μm or less. -Garnet fine powder has high productivity, excellent filling properties, is single-phase, and has high sintering activity. Therefore, if the rare earth / aluminum / garnet fine powder is used for molding and sintering, a sintered body having a high sintering density can be obtained under mild conditions.
【図１】は、本発明の実施例１で得られたＹＡＧの粒子
状態を示す顕微鏡組織写真である。FIG. 1 is a micrograph showing the particle state of YAG obtained in Example 1 of the present invention.
【図２】は、比較例１で得られたＹＡＧの粒子状態を示
す顕微鏡組織写真である。FIG. 2 is a micrograph showing the particle state of YAG obtained in Comparative Example 1.
Claims (7)
粒径Ｄ50が１．８μｍ以下であって、粒度分布の９０％
粒径（Ｄ90）と１０％粒径（Ｄ10）との差が１０．０μ
ｍ以下である希土類・アルミニウム・ガーネット微粉
末。1. A specific surface area of 3.5 m 2 / g or more, an average particle diameter D 50 of 1.8 μm or less, and 90% of the particle size distribution.
The difference between the particle size (D 90 ) and the 10% particle size (D 10 ) is 10.0 μm.
m or less, rare earth, aluminum or garnet fine powder.
れらが単独もしくは２個以上連なった形状からなる粒子
で構成される請求項１に記載の希土類・アルミニウム・
ガーネット微粉末。2. The rare earth / aluminum / primary particle according to claim 1, wherein the primary particles are rounded particles, and are composed of particles having a shape of one or two or more connected.
Garnet fine powder.
とを特徴とする請求項１または請求項２に記載の希土類
・アルミニウム・ガーネット微粉末。3. The rare earth / aluminum / garnet fine powder according to claim 1, wherein the crystallite size is 600 ° or less.
・アルミニウム・ガーネットであって、ＲがＡ1-XＢXの
組成からなり、ＡはＹ、Ｄｙ、Ｈｏ、Ｅｒ、Ｔｍ、Ｙ
ｂ、Ｌｕから選択された一種又は二種以上、ＢはＹを含
む希土類元素から選択された一種または二種以上、但
し、ＡとＢとは相互に同一のものを含まない、Ｘは原子
比を表し０〜０．２であることを特徴とする請求項１〜
３のいずれかに記載の希土類・アルミニウム・ガーネッ
ト微粉末。4. A rare earth aluminum garnet expressed by the composition formula of R 3 Al 5 O 12, R is the composition of A 1-X B X, A is Y, Dy, Ho, Er, Tm, Y
b, one or more selected from Lu, B is one or more selected from rare earth elements including Y, provided that A and B do not include the same thing as each other, and X is an atomic ratio And represents 0 to 0.2.
3. The rare earth / aluminum / garnet fine powder according to any one of 3.
とも１種以上を合計で１０〜１００００ｐｐｍ含有する
請求項１〜４のいずれかに記載の希土類・アルミニウム
・ガーネット微粉末。5. The rare earth / aluminum / garnet fine powder according to claim 1, which contains at least one compound of Mg, Si and Ca in a total amount of 10 to 10000 ppm.
土類・アルミニウム・ガーネット微粉末を用いた焼結
体。6. A sintered body using the rare earth / aluminum / garnet fine powder according to claim 1.
ミナを希土類鉱酸塩水溶液に懸濁させ、沈殿剤を加えて
希土類元素をアルミナ表面にコーティングし、濾過、洗
浄後、焼成することからなる希土類・アルミニウム・ガ
ーネット微粉末の製造方法。7. An alumina having a specific surface area of 20 to 300 m 2 / g is suspended in an aqueous solution of a rare earth mineral, a precipitant is added thereto, and the surface of the alumina is coated with a rare earth element. Of rare earth, aluminum and garnet fine powder.
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| WO2004067474A1 (en) * | 2003-01-27 | 2004-08-12 | Konoshima Chemical Co., Ltd. | Rare earth garnet sintered compact |
| US7691765B2 (en) | 2005-03-31 | 2010-04-06 | Fujifilm Corporation | Translucent material and manufacturing method of the same |
| JP2011136877A (en) * | 2009-12-28 | 2011-07-14 | Sumitomo Osaka Cement Co Ltd | Corrosion-resistant member and method for producing the same |
| JP2013129199A (en) * | 2013-01-25 | 2013-07-04 | National Institutes Of Natural Sciences | Optical material and method for manufacturing the same |
| JP2014019860A (en) * | 2012-07-24 | 2014-02-03 | Shin Etsu Chem Co Ltd | Manufacturing method of phosphor precursor, manufacturing method of phosphor, and wavelength conversion parts |
| JPWO2013111811A1 (en) * | 2012-01-25 | 2015-05-11 | エム・テクニック株式会社 | Garnet precursor fine particles and method for producing fine particles of garnet structure |
| JP2020172702A (en) * | 2019-04-12 | 2020-10-22 | 信越化学工業株式会社 | Thermal spray material, method for manufacturing the same, thermal spray coating, method for forming the same, and thermal spray member |
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| JPH0412049A (en) * | 1990-04-27 | 1992-01-16 | Isuzu Motors Ltd | Production of sintered ceramic material |
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| JPH10114519A (en) * | 1996-08-20 | 1998-05-06 | Kounoshima Kagaku Kogyo Kk | Production of yttrium aluminum garnet powder |
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| JPH0292817A (en) * | 1988-09-27 | 1990-04-03 | Natl Inst For Res In Inorg Mater | Production of yttrium aluminium garnet |
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