JP5034349B2 - Zirconia fine powder, production method thereof and use thereof - Google Patents
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本発明は、光コネクター部品，精密加工部品及び粉砕機用部材等の構造用セラミックスの原料に用いられる、とくに成形性がよく、低温焼結性にも優れた新規ジルコニア微粉末及びその製造方法並びにそのジルコニア微粉末をスラリーにして噴霧造粒して得られるジルコニア顆粒に関するものである。 The present invention relates to a novel zirconia fine powder which is used as a raw material for structural ceramics such as optical connector parts, precision processed parts and pulverizer members, and which has particularly good formability and excellent low-temperature sinterability, and a method for producing the same. The present invention relates to zirconia granules obtained by making the zirconia fine powder into a slurry and spray granulating.
ジルコニアセラミックスは、高強度，高靭性を発現するため、光コネクター部品，精密加工部品，粉砕メディア，粉砕機用部剤，刃物等の幅広い用途で使用されている。しかしながら、このような高強度・高靭性を有するジルコニアセラミックスは、空気中、２００〜３００℃の温度で長時間曝されると、準安定相である正方晶が安定相の単斜晶へ約４％の体積膨張を伴って相変態するので、微細クラックが発生して強度・靭性が低下、すなわち劣化することが指摘されている。この欠点を改善するために、出発原料であるジルコニア粉末の焼結性を改善して、ジルコニアセラミックスの耐劣化性を向上させている。焼結性の改善には、ジルコニア粉末の比表面積を高くすることが有効であるが、いっぽう、比表面積の増加とともに粉末の凝集性が高くなって、成形しにくくなるという欠点も有している。通常、凝集性の高い粉末を用いて乾式プレスを行うと、成形体密度が不均一になってラミネーションが発生し、またプレス時に金型壁面と成形体との付着性が大きく、金型から成形体を取出す際、成形体の破片が金型に貼りつきやすくなって得られる焼結体に傷や割れが発生する。このような傷や割れは、比表面積の大きいものほど著しく発生しやすくなる。 Since zirconia ceramics exhibit high strength and high toughness, they are used in a wide range of applications such as optical connector parts, precision processed parts, grinding media, pulverizer parts, blades and the like. However, when such zirconia ceramics having high strength and high toughness are exposed to a temperature of 200 to 300 ° C. for a long time in air, the tetragonal crystal, which is a metastable phase, is converted to a monoclinic crystal having a stable phase by about 4%. It has been pointed out that microcracks are generated and the strength and toughness are lowered, that is, deteriorated. In order to improve this defect, the sinterability of the zirconia powder as a starting material is improved to improve the deterioration resistance of the zirconia ceramics. In order to improve the sinterability, it is effective to increase the specific surface area of the zirconia powder, but on the other hand, as the specific surface area increases, the cohesiveness of the powder increases and it becomes difficult to form. . Normally, when dry pressing is performed using highly cohesive powder, the density of the compact becomes uneven and lamination occurs, and the adhesion between the mold wall surface and the compact is large during pressing, and molding is performed from the mold. When the body is taken out, scratches and cracks occur in the sintered body that is obtained when the fragments of the molded body easily stick to the mold. Such scratches and cracks are more likely to occur as the specific surface area increases.
例えば、ＢＥＴ比表面積が１〜１０ｍ２／ｇ、平均粒子径０．１〜１μｍ、及び累積分布において０．１μｍ以下及び１０μｍを超える粒子の占める割合が５％以下の酸化ジルコニウム粉末が提案されている（特許文献１）。この酸化ジルコニウム粉末は、低比表面積のため良好な成形性を示すものの、焼結温度が１５００℃と高く、焼結性という観点でまだ改善の余地が残っていた。 For example, zirconium oxide powder having a BET specific surface area of 1 to 10 m 2 / g, an average particle diameter of 0.1 to 1 μm, and a proportion of particles having a cumulative distribution of 0.1 μm or less and more than 10 μm is 5% or less has been proposed. (Patent Document 1). Although this zirconium oxide powder exhibits good moldability due to its low specific surface area, the sintering temperature is as high as 1500 ° C., and there is still room for improvement in terms of sinterability.
最近、焼結性のよいジルコニア粉末が提案されている（例えば特許文献２）。このジルコニア粉末は、ＢＥＴ比表面積が５〜２０ｍ２／ｇ、平均粒径が０．２〜１μｍ、かつ粒径分布が０．１〜１０μｍの範囲において２つのピークを有するものであり、この粉末に少量のアルミナを含有させ、成形し焼結させると１３５０℃の温度で高密度のジルコニア焼結体が得られることが開示されている。しかし、特許文献２の粉末は、平均粒径が０．７μｍであり、かつ、２μｍ以上の粒子を多く含むものであった。 Recently, zirconia powder with good sinterability has been proposed (for example, Patent Document 2). This zirconia powder has two peaks in a BET specific surface area of 5 to 20 m 2 / g, an average particle size of 0.2 to 1 μm, and a particle size distribution of 0.1 to 10 μm. It is disclosed that a high-density zirconia sintered body can be obtained at a temperature of 1350 ° C. when a small amount of alumina is contained in and then molded and sintered. However, the powder of Patent Document 2 has an average particle size of 0.7 μm and contains many particles of 2 μm or more.
最近では、種々の用途での高性能化の要求がさらに高まってきており、特に使用環境の厳しい条件でも劣化しない信頼性の高いジルコニアセラミックスが望まれ、成形性がよく、かつ、低い温度で焼結するジルコニア粉末が求められている。 Recently, there has been an increasing demand for higher performance in various applications. In particular, a highly reliable zirconia ceramic that does not deteriorate even under severe conditions of use is desired, and has good formability and is fired at a low temperature. There is a need for zirconia powders to set.
本発明では、上記のような従来方法における欠点を解消した、成形性がよく、かつ、低温焼結性にも優れ、これらに加えて焼結体にしたときの品質の信頼性にも優れたジルコニア微粉末の提供、ならびにそのジルコニア微粉末を簡易なプロセスにより製造することのできる方法の提供を目的とするものである。 In the present invention, the disadvantages in the conventional method as described above are eliminated, the moldability is good, and the low-temperature sinterability is excellent. In addition to these, the quality of the sintered body is also excellent in reliability. An object of the present invention is to provide a zirconia fine powder and a method capable of producing the zirconia fine powder by a simple process.
本発明者らは、ジルコニア粉末の粒径分布と成形及び焼結性との関係について詳細に検討し、本発明に到達した。 The present inventors have studied in detail the relationship between the particle size distribution of zirconia powder and the molding and sintering properties, and have reached the present invention.
即ち、本発明は、
１）安定化剤としてイットリア，カルシア，マグネシア及びセリアの１種以上を含むジルコニア微粉末であって、該ジルコニア微粉末のＢＥＴ比表面積が５〜１０ｍ２／ｇ、平均粒径が０．３〜０．６μｍの範囲内にあり、かつ、粒径分布の累積曲線において、粒径０．２μｍ，１μｍ及び２μｍでの粒子が占める割合がそれぞれ０％，９５％以上及び１００％であるジルコニア微粉末。
２）粒径分布のピークが０．２〜２μｍの範囲にのみ存在する上記２）のジルコニア微粉末。
３）安定化剤としてイットリアを２〜４モル％含み、かつ、単斜晶相率が１０〜４０％である上記１）又は２）のジルコニア微粉末。
４）ジルコニア微粉末が１種以上の添加物を含む上記１）乃至３）のいずれかのジルコニア微粉末。
５）該添加物の陽イオンが、ジルコニウムイオンのイオン半径よりも小さいイオン半径を有する陽イオン及び／又は価数が４価以外の陽イオンである上記４）記載のジルコニア微粉末。
６）添加物の陽イオンが、アルミニウム，珪素及びゲルマニウムの群から選ばれる一種以上の陽イオンである上記４）又は５）記載のジルコニア微粉末。
７）ジルコニウム塩水溶液の加水分解で得られる水和ジルコニアゾルを、乾燥，仮焼，粉砕してジルコニア粉末を得る方法において、該ジルコニウム塩水溶液にアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を加えた後に、反応率が９８％以上になるまで加水分解を行って得られる水和ジルコニアゾルに、安定化剤の原料としてイットリウム，カルシウム，マグネシウム及びセリウムの化合物の１種以上を添加して乾燥し、１０００〜１２００℃の範囲で仮焼してジルコニア粉末を得、次いで該ジルコニア粉末の平均粒径が０．３〜０．６μｍの範囲になるように、直径３ｍｍ以下のジルコニアボールを用いて湿式粉砕することを特徴とする上記１）乃至３）のいずれかに記載のジルコニア微粉末の製造方法。
８）上記７）記載のジルコニア微粉末の製造方法において、水和ジルコニアゾル、又は、仮焼して得られる粉末に添加物を加えることを特徴とする請求項４乃至６のいずれかに記載のジルコニア微粉末の製造方法。
９）該イットリウムの化合物を酸化物換算で２〜４モル％添加することを特徴とする上記７）又は８）記載のジルコニア微粉末の製造方法。
１０）上記１）乃至６）のいずれかに記載のジルコニア微粉末をスラリーにして噴霧造粒することにより得られ、平均粒径が３０〜８０μｍ、軽装嵩密度が１．００〜１．４０ｇ／ｃｍ３であるジルコニア顆粒。
That is, the present invention
1) A zirconia fine powder containing at least one of yttria, calcia, magnesia and ceria as a stabilizer, the zirconia fine powder having a BET specific surface area of 5 to 10 m 2 / g and an average particle size of 0.3 to Zirconia fine powder in the range of 0.6 μm, and in the cumulative curve of the particle size distribution, the proportions of particles having a particle size of 0.2 μm, 1 μm and 2 μm are 0%, 95% or more and 100%, respectively. .
2) The zirconia fine powder according to 2) above, wherein the peak of the particle size distribution exists only in the range of 0.2 to 2 μm.
3) The zirconia fine powder according to 1) or 2) above, containing 2 to 4 mol% of yttria as a stabilizer and having a monoclinic phase ratio of 10 to 40%.
4) The zirconia fine powder according to any one of 1) to 3) above , wherein the zirconia fine powder contains one or more additives.
5) The zirconia fine powder according to 4) above, wherein the cation of the additive is a cation having an ionic radius smaller than that of zirconium ions and / or a cation having a valence other than tetravalent.
6) The zirconia fine powder according to 4) or 5) above, wherein the cation of the additive is at least one cation selected from the group of aluminum, silicon and germanium.
7) In a method of obtaining a zirconia powder by drying, calcining, and pulverizing a hydrated zirconia sol obtained by hydrolysis of an aqueous zirconium salt solution, an alkali metal hydroxide and / or an alkaline earth metal water is added to the aqueous zirconium salt solution. Add one or more compounds of yttrium, calcium, magnesium and cerium as raw materials for the stabilizer to the hydrated zirconia sol obtained by hydrolysis until the reaction rate reaches 98% or more after adding the oxide And dried and calcined in the range of 1000 to 1200 ° C. to obtain zirconia powder, and then the zirconia balls having a diameter of 3 mm or less so that the average particle diameter of the zirconia powder is in the range of 0.3 to 0.6 μm. The method for producing a fine zirconia powder according to any one of the above 1) to 3) , wherein wet pulverization is performed using
8) In the above 7) the production method of the fine zirconia fine powder according hydrated zirconia sol, or, according to one of claims 4 to 6, wherein the addition of additives to the powder obtained by calcining A method for producing zirconia fine powder.
9) The method for producing a fine zirconia powder according to 7) or 8) above, wherein the yttrium compound is added in an amount of 2 to 4 mol% in terms of oxide.
10) It is obtained by spray granulating the zirconia fine powder according to any one of 1) to 6) above, having an average particle size of 30 to 80 μm, and a light bulk density of 1.00 to 1.40 g / Zirconia granules that are cm 3 .
本発明の「安定化剤としてイットリア，カルシア，マグネシア及びセリアの１種以上を含むジルコニア微粉末であって、該ジルコニア微粉末のＢＥＴ比表面積が５〜１０ｍ２／ｇ、平均粒径が０．３〜０．６μｍの範囲内にあり、かつ、粒径分布の累積曲線において、粒径０．２μｍ，１μｍ及び２μｍでの粒子が占める割合がそれぞれ０％，９５％以上及び１００％であるジルコニア微粉末」を成形して焼結すると低い焼結温度で高い焼結密度や曲げ強度のジルコニア焼結体が得られる事が判明して本発明を完成するに至った。 “A zirconia fine powder containing at least one of yttria, calcia, magnesia and ceria as a stabilizer, the zirconia fine powder has a BET specific surface area of 5 to 10 m 2 / g and an average particle size of 0.1 of the present invention. Zirconia is in the range of 3 to 0.6 μm, and the proportion of particles having a particle size of 0.2 μm, 1 μm, and 2 μm in the cumulative particle size distribution curve is 0%, 95% or more, and 100%, respectively. When the “fine powder” is molded and sintered, a zirconia sintered body having a high sintering density and bending strength can be obtained at a low sintering temperature, and the present invention has been completed.
以下、本発明をさらに詳細に説明する。 Hereinafter, the present invention will be described in more detail.
本明細書において、ジルコニア微粉末に係わる「平均粒径」とは、体積基準で表される粒径分布の累積カーブが中央値（メディアン径；累積カーブの５０％に対応する粒径）である粒子と同じ体積の球の直径をいい、レーザー回折法による粒径分布測定装置によって測定することができる。 In the present specification, the “average particle size” related to the fine zirconia powder is a median value (median diameter; particle size corresponding to 50% of the cumulative curve) of the cumulative particle size distribution expressed by volume. The diameter of a sphere having the same volume as the particle, which can be measured by a particle size distribution measuring apparatus using a laser diffraction method.
「安定化剤濃度」とは、安定化剤／（ＺｒＯ２＋安定化剤）の比率をモル％として表した値をいう。 “Stabilizer concentration” refers to a value expressed as mole% of the ratio of stabilizer / (ZrO 2 + stabilizer).
「単斜晶相率（ｆｍ）」とは、粉末Ｘ腺回折（ＸＲＤ）測定により単斜晶相の（１１１）及び（１１−１）面，正方晶相の（１１１）面，立方晶の（１１１）面の回折強度をそれぞれ求めて、以下の数式１により算出されたものの値をいう。
The “monoclinic phase ratio (f m )” means the (111) and (11-1) planes of the monoclinic phase, the (111) plane of the tetragonal phase, and the cubic crystal by powder X-ray diffraction (XRD) measurement. The diffraction intensities of the (111) plane are calculated, and the values calculated by the following
「イオン半径」とは、Ｓｈａｎｎｏｎによって報告（Ａｃｔａ．Ｃｒｙｓｔａｌｌｏｇｒ．，Ａ３２，７５１−６７（１９７６）．）されている値のことをいう。 The “ion radius” refers to a value reported by Shannon (Acta. Crystallogr., A32, 751-67 (1976).).
「添加物含有量」とは、添加物／（ＺｒＯ２＋安定化剤＋添加物）の比率を重量％として表した値をいう。ここで、添加物は酸化物に換算した値である。 “Additive content” refers to a value expressed as a weight% ratio of additive / (ZrO 2 + stabilizer + additive). Here, the additive is a value converted to an oxide.
水和ジルコニアゾルに係わる「反応率」とは、水和ジルコニアゾル含有液を限外濾過して、その濾液中に存在する未反応物のジルコニウム量を誘導結合プラズマ発光分光分析により求めて、水和ジルコニアゾルの生成量を算出し、原料仕込量に対する水和ジルコニアゾル量の比率として表したものの値をいう。 The “reaction rate” related to the hydrated zirconia sol is obtained by ultrafiltration of a hydrated zirconia sol-containing liquid and determining the amount of zirconium in the unreacted substance present in the filtrate by inductively coupled plasma emission spectrometry. The amount of zirconia sol produced is calculated and the value expressed as the ratio of the amount of hydrated zirconia sol to the amount of raw material charged.
「平均粒径」とは、粒度分布測定装置または電子顕微鏡等で測定されるものであり、例えば光子相関法で得られたものの値をいう。 The “average particle diameter” is measured with a particle size distribution measuring apparatus or an electron microscope, and refers to a value obtained by, for example, a photon correlation method.
本発明のジルコニア微粉末は、安定化剤としてイットリア，カルシア，マグネシア及びセリアの１種以上を含むことを必須とする。上記の安定化剤を含まないジルコニア微粉末を成形し焼結させると、焼結時にマルテンサイト変態に伴う膨張・収縮が起こり、その結果として材料が破壊するため、セラミックス原料粉末に適さないものとなるからである。 The zirconia fine powder of the present invention must contain at least one of yttria, calcia, magnesia and ceria as a stabilizer. When molding and sintering zirconia fine powder that does not contain the above stabilizers, expansion and contraction associated with martensite transformation occurs during sintering, and as a result, the material is destroyed. Because it becomes.
また、上記のジルコニア微粉末は、ＢＥＴ比表面積が５〜１０ｍ２／ｇの範囲にあるものでなければならない。ジルコニア微粉末のＢＥＴ比表面積が、５ｍ２／ｇよりも小さくなると低温側で焼結しにくい粉末となり、また、１０ｍ２／ｇよりも大きくなると粒子間の凝集力が著しい粉末となるために、セラミックス原料粉末としては扱いにくく適さないものとなる。より好ましいＢＥＴ比表面積は６〜９ｍ２／ｇである。 The fine zirconia powder must have a BET specific surface area in the range of 5 to 10 m 2 / g. When the BET specific surface area of the zirconia fine powder is smaller than 5 m 2 / g, it becomes a powder that is difficult to sinter on the low temperature side, and when larger than 10 m 2 / g, the cohesive force between particles becomes a remarkable powder, As ceramic raw material powder, it is difficult to handle and unsuitable. A more preferable BET specific surface area is 6 to 9 m 2 / g.
本発明のジルコニア微粉末は、平均粒径が０．３〜０．６μｍの範囲内であることを必要とする。ジルコニア微粉末の平均粒径が０．３μｍよりも小さくなると粉末の凝集性を高める微小粒子が多くなって成形しにくいものとなり、いっぽう、０．６μｍよりも大きくなると硬い凝集粒子を含む粗粒が多くなるために、成形しにくいものとなり、かつ、粗粒が焼結の緻密化を阻害するために焼結性の悪いものとなるからである。好ましい平均粒径は０．４〜０．５μｍである。 The fine zirconia powder of the present invention needs to have an average particle size in the range of 0.3 to 0.6 μm. If the average particle size of the zirconia fine powder is smaller than 0.3 μm, the number of fine particles that increase the cohesiveness of the powder increases, making it difficult to mold. On the other hand, if the average particle size is larger than 0.6 μm, coarse particles containing hard agglomerated particles are formed. This is because the amount increases, so that it becomes difficult to mold, and the coarse particles inhibit the densification of the sintering, so that the sinterability becomes poor. A preferable average particle diameter is 0.4 to 0.5 μm.
更に、上記のジルコニア微粉末は、粒径分布の累積曲線において、粒径０．２μｍ，１μｍ及び２μｍでの粒子が占める割合がそれぞれ０％，９５％以上及び１００％でなければならない。粒径０．２μｍでの粒子の占める割合が０％よりも大きくなると粉末の凝集性を高める微小粒子が多くなり、いっぽう、粒径１μｍでの粒子の占める割合が９５％よりも小さく、又は、粒径２μｍでの粒子の占める割合が１００％未満になると、硬い凝集粒子を含む粗粒が多くなって、上記のとおり、成形性及び焼結性の劣るものになるからである。粒径１μｍでの粒子の占める割合が１００％であれば、さらに焼結性のよいものとなる。 Furthermore, in the cumulative curve of the particle size distribution, the proportion of particles having a particle size of 0.2 μm, 1 μm and 2 μm should be 0%, 95% or more and 100%, respectively. When the proportion of particles with a particle size of 0.2 μm is greater than 0%, the number of fine particles that increase the cohesiveness of the powder increases, whereas the proportion of particles with a particle size of 1 μm is less than 95%, or This is because when the proportion of particles having a particle size of 2 μm is less than 100%, coarse particles containing hard aggregated particles increase, and as described above, the moldability and sinterability are poor. If the proportion of particles with a particle size of 1 μm is 100%, the sinterability is further improved.
上記の条件に付け加えて、粒径分布のピークが０．２〜２μｍの範囲にのみ存在すれば、よりいっそう成形性及び焼結性のよいものとなる。 In addition to the above conditions, if the peak of the particle size distribution exists only in the range of 0.2 to 2 μm, the moldability and sinterability will be even better.
ジルコニアセラミックスの特性は、安定化剤の種類や濃度によって変化するので、必要に応じて安定化剤を選択し、安定化剤の濃度を設定すればよい。安定化剤がジルコニア粒子に固溶しているものであれば、焼結の緻密化が均一に進行するのでより好ましいものとなる。特に、安定化剤としてイットリアを２〜４モル％含み、かつ、単斜晶相率が１０〜４０％である結晶構造を有するものであれば、成形し焼結させて得られる焼結体に残る気孔のサイズが小さくなり、かつ、その数が少なくなり、従って高密度の焼結体となって、機械的強度及び靭性に優れたジルコニアセラミックスとなる。より好ましいイットリア濃度は２．３〜３．５モル％であり、単斜晶相率は１０〜３０％である。 Since the characteristics of zirconia ceramics vary depending on the type and concentration of the stabilizer, the stabilizer may be selected as necessary and the concentration of the stabilizer may be set. If the stabilizer is a solid solution in the zirconia particles, the densification of sintering proceeds uniformly, which is more preferable. In particular, as long as it contains 2 to 4 mol% of yttria as a stabilizer and has a crystal structure with a monoclinic phase ratio of 10 to 40%, a sintered body obtained by molding and sintering is used. The size of the remaining pores is reduced and the number thereof is reduced, so that the sintered body becomes a high-density sintered body and becomes zirconia ceramics excellent in mechanical strength and toughness. A more preferable yttria concentration is 2.3 to 3.5 mol%, and a monoclinic phase rate is 10 to 30%.
さらに、上記のジルコニア微粉末が一種以上の添加物を含むと、成形して焼結する際の緻密化速度が促進されるので、よりいっそう焼結性に優れたものになる。このようなジルコニア微粉末を原料に用いて、成形し焼結させると、低い焼結温度で高密度の焼結体が得られるので、上記のとおり、劣化しにくいものとなって、極めて信頼性の高いジルコニアセラミックスとなる。特に、添加物の陽イオンが、ジルコニウムイオンのイオン半径（０．８６オングストローム）よりも小さいイオン半径（ｒ）を有するもの及び／又は価数（Ｚ）が４価以外のものであれば、焼結の緻密化速度が著しく促進されるのでより好ましいものとなる。最適な添加物含有量は、酸化物換算で０．０５〜１重量％である。添加物の陽イオンとしては、アルミニウム（ｒ＝０．６８オングストローム，Ｚ＝３），珪素（ｒ＝０．５４オングストローム，Ｚ＝４）及びゲルマニウム（ｒ＝０．６７オングストローム，Ｚ＝４）の群から選ばれる一種以上のものが効果的であり、これらの中でアルミニウムとゲルマニウムの組合せが最もよい。 Furthermore, when the above zirconia fine powder contains one or more additives, the densification rate at the time of molding and sintering is accelerated, so that the sinterability is further improved. When such a zirconia fine powder is used as a raw material and then molded and sintered, a high-density sintered body can be obtained at a low sintering temperature. High zirconia ceramics. In particular, if the cation of the additive has an ionic radius (r) smaller than the ionic radius of zirconium ion (0.86 angstrom) and / or the valence (Z) is other than tetravalent, This is more preferable because the densification speed of the knot is significantly accelerated. The optimum additive content is 0.05 to 1% by weight in terms of oxide. Additive cations include aluminum (r = 0.68 angstrom, Z = 3), silicon (r = 0.54 angstrom, Z = 4) and germanium (r = 0.67 angstrom, Z = 4). One or more selected from the group is effective, and among these, the combination of aluminum and germanium is the best.
本発明のジルコニア微粉末を得るにあたっては、ジルコニウム塩水溶液の加水分解で得られる水和ジルコニアゾルを、乾燥，仮焼，粉砕してジルコニア粉末を得る方法において、該ジルコニウム塩水溶液にアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を加えた後に、反応率が９８％以上になるまで加水分解を行って得られる水和ジルコニアゾルに、安定化剤の原料としてイットリウム，カルシウム，マグネシウム及びセリウムの化合物の１種以上を添加して乾燥することを必要とする。ジルコニウム塩水溶液にアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を加えないと、又は水和ジルコニアゾルの生成率が９８％よりも小さくなると、上記水酸化物の未添加によって生成する極めて粒径の小さい水和ジルコニアゾルの前駆体、又は未反応物に起因する粒子間の強固な焼結が起るために、粒子間の凝集性が著しく、かつ、硬い凝集粒子を含む粗粒も多くなり、上記のとおり、成形しにくく、かつ、焼結性の悪いものとなるからである。好ましいアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物の添加量は［ＯＨ］／［Ｚｒ］のモル濃度比として０．００５〜０．１の範囲であり、好ましい反応率は９９％以上である。水和ジルコニアゾルと安定化剤の原料化合物との混合方法に制限はなく、例えば加水分解後の水和ジルコニアゾル含有液に安定化剤の原料化合物を所定量添加してもよく、あるいは加水分解前のジルコニウム塩水溶液に前もって添加していてもよい。安定化剤の原料に用いられる化合物としては、塩化物，フッ化物，硝酸塩，炭酸塩，硫酸塩，酢酸塩，酸化物，水酸化物などを挙げることができる。安定化剤の原料としてイットリウム化合物を酸化物換算で２〜４モル％添加すると、上記の仮焼及び粉砕条件で得られるジルコニア微粉末の単斜晶相率が１０〜４０％の範囲内となり、前記のとおり、機械的強度及び靭性に優れたものになる。より好ましいイットリア濃度は２．３〜３．５モル％である。また、水和ジルコニアゾルの乾燥方法については、例えば、混合溶液をそのまま、または該混合溶液に有機溶媒を添加して噴霧乾燥する方法、該混合溶液にアルカリなどを添加して濾過，水洗したあとに乾燥する方法を挙げることができる。 In obtaining the zirconia fine powder of the present invention, the hydrated zirconia sol obtained by hydrolysis of the zirconium salt aqueous solution is dried, calcined, and pulverized to obtain the zirconia powder. To the hydrated zirconia sol obtained by performing hydrolysis until the reaction rate is 98% or more after adding the product and / or alkaline earth metal hydroxide, and yttrium, calcium, magnesium and It is necessary to add and dry one or more cerium compounds. If the alkali metal hydroxide and / or alkaline earth metal hydroxide is not added to the zirconium salt aqueous solution, or if the rate of formation of the hydrated zirconia sol is less than 98%, it is generated by the addition of the hydroxide. Precipitation of hydrated zirconia sol with a very small particle diameter, or strong sintering between particles due to unreacted substances occurs, so that coarse particles containing remarkably agglomerated particles and containing hard agglomerated particles This is because, as described above, it is difficult to mold and the sinterability is poor. The addition amount of the preferred alkali metal hydroxide and / or alkaline earth metal hydroxide is in the range of 0.005 to 0.1 as the molar concentration ratio of [OH] / [Zr], and the preferred reaction rate is 99%. That's it. There is no restriction on the method of mixing the hydrated zirconia sol and the raw material of the stabilizer. For example, a predetermined amount of the raw material of the stabilizer may be added to the hydrous hydrated zirconia sol-containing liquid, or hydrolysis may be performed. It may be added in advance to the previous aqueous zirconium salt solution. Examples of the compound used as the raw material for the stabilizer include chloride, fluoride, nitrate, carbonate, sulfate, acetate, oxide, hydroxide and the like. When 2-4 mol% of yttrium compound is added in terms of oxide as a raw material for the stabilizer, the monoclinic phase ratio of the zirconia fine powder obtained under the above calcining and pulverization conditions is in the range of 10-40%, As described above, the mechanical strength and toughness are excellent. A more preferred yttria concentration is 2.3 to 3.5 mol%. As for the method of drying the hydrated zirconia sol, for example, the mixed solution is used as it is or spray-dried by adding an organic solvent to the mixed solution, and after adding alkali or the like to the mixed solution and filtering and washing with water. The method of drying can be mentioned.
上記の水和ジルコニアゾルは、ジルコニウム塩水溶液にアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を添加して加水分解させ、反応率が９８％以上を満足しているものが得られる方法であれば、いかなる反応条件で得られたものでもよい。例えば、ジルコニウム塩水溶液にアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を所定量添加して加水分解させる、加水分解で得られた水和ジルコニアゾルとアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物をジルコニウム塩水溶液に所定量添加して加水分解させる、などの方法を挙げることができる。とくに、所定量のアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を添加したジルコニウム塩水溶液の加水分解で得られた水和ジルコニアゾル含有液の一部を反応槽から連続及び／又は間欠的に排出し、かつ、当該水和ジルコニアゾル含有液の体積が一定に保たれるように、その排出量と同量の所定量のアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物を添加したジルコニウム塩水溶液を連続及び／又は間欠的に反応槽に供給しながら加水分解させると、より反応率の高い水和ジルコニアゾルが効率よく得られるので効果的である。 The above hydrated zirconia sol is obtained by adding an alkali metal hydroxide and / or an alkaline earth metal hydroxide to a zirconium salt aqueous solution and hydrolyzing it, so that a reaction rate of 98% or more is obtained. As long as it is a method, it may be obtained under any reaction conditions. For example, a predetermined amount of an alkali metal hydroxide and / or alkaline earth metal hydroxide is added to a zirconium salt aqueous solution to cause hydrolysis, and a hydrated zirconia sol obtained by hydrolysis and an alkali metal hydroxide and / or Examples thereof include a method in which a predetermined amount of an alkaline earth metal hydroxide is added to a zirconium salt aqueous solution to cause hydrolysis. In particular, a part of the hydrated zirconia sol-containing liquid obtained by hydrolysis of an aqueous zirconium salt solution to which a predetermined amount of alkali metal hydroxide and / or alkaline earth metal hydroxide is added is continuously and / or removed from the reaction vessel. Discharge intermittently and keep the volume of the hydrated zirconia sol-containing liquid constant so that a predetermined amount of alkali metal hydroxide and / or alkaline earth metal hydroxide equivalent to the discharge amount is maintained. It is effective to hydrolyze the aqueous zirconium salt solution to which the product is added while continuously and / or intermittently supplying it to the reaction vessel, since a hydrated zirconia sol having a higher reaction rate can be obtained efficiently.
水和ジルコニアゾルの製造に用いられるジルコニウム塩としては、オキシ塩化ジルコニウム，硝酸ジルコニル，塩化ジルコニウム，硫酸ジルコニウムなどが挙げられるが、この他に水酸化ジルコニウムと酸との混合物を用いてもよい。ジルコニウム塩水溶液に加えるアルカリ金属水酸化物及び／又はアルカリ土類金属水酸化物としては、リチウム，ナトリウム，カリウム，マグネシウム，カルシウム等の水酸化物を挙げることができる。上記の水酸化物は、水溶液にして加えることが好ましい。 Zirconium salts used for the production of the hydrated zirconia sol include zirconium oxychloride, zirconyl nitrate, zirconium chloride, zirconium sulfate and the like, but in addition, a mixture of zirconium hydroxide and acid may be used. Examples of the alkali metal hydroxide and / or alkaline earth metal hydroxide added to the zirconium salt aqueous solution include hydroxides such as lithium, sodium, potassium, magnesium, and calcium. The hydroxide is preferably added as an aqueous solution.
次いで、本発明では、上記で得られた水和ジルコニアゾルの乾燥粉を１０００〜１２００℃の温度で仮焼する。仮焼温度がこの範囲外になると、本発明の下記粉砕条件で得られるジルコニア微粉末の凝集性が著しく強くなって、あるいは硬い凝集粒子を含む粗粒が多くなるために平均粒径が０．３〜０．５μｍの範囲外、かつ、粒径分布の累積カーブにおける粒径０．２μｍ，１μｍ又は２μｍでの粒子が占める割合がそれぞれ０％より大きく，９５％未満又は１００％未満となって、本発明のジルコニア微粉末が得られなり易い。より好ましい仮焼温度は１０００〜１１００℃である。仮焼温度の保持時間は０．５〜１０時間がよく、昇温速度は０．５〜１０℃／ｍｉｎが好ましい。保持時間が０．５よりも短くなると均一に仮焼されにくく、１０時間よりも長くなると生産性が低下するので好ましくない。また、昇温速度が０．５℃／ｍｉｎよりも小さくなると設定温度に達するまでの時間が長くなり、１０℃／ｍｉｎよりも大きくなると仮焼時に粉末が激しく飛散して操作性が悪くなり生産性が低下する。 Next, in the present invention, the dried powder of the hydrated zirconia sol obtained above is calcined at a temperature of 1000 to 1200 ° C. If the calcining temperature is outside this range, the agglomeration property of the zirconia fine powder obtained under the following pulverization conditions of the present invention becomes remarkably strong, or the average particle size becomes 0.00 because the number of coarse particles containing hard agglomerated particles increases. The proportion of particles with a particle size of 0.2 μm, 1 μm or 2 μm outside the range of 3 to 0.5 μm and in the cumulative curve of particle size distribution is greater than 0%, less than 95% or less than 100%, respectively. The zirconia fine powder of the present invention is not easily obtained. A more preferable calcining temperature is 1000 to 1100 ° C. The holding time of the calcining temperature is preferably 0.5 to 10 hours, and the temperature raising rate is preferably 0.5 to 10 ° C./min. If the holding time is shorter than 0.5, uniform calcination is difficult, and if it is longer than 10 hours, the productivity is lowered, which is not preferable. Also, if the rate of temperature rise is less than 0.5 ° C / min, the time until the set temperature is reached is longer, and if it is greater than 10 ° C / min, the powder scatters vigorously during calcination, resulting in poor operability and production. Sex is reduced.
次いで、上記で得られた仮焼粉を平均粒径が０．３〜０．６μｍの範囲になるまで、直径３ｍｍ以下のジルコニアボールを用いて湿式粉砕することが好ましい。 Next, it is preferable to wet pulverize the calcined powder obtained above using zirconia balls having a diameter of 3 mm or less until the average particle diameter is in the range of 0.3 to 0.6 μm.
水和ジルコニアゾル合成時に、ジルコニウム塩水溶液にアルカリ金属及び／又はアルカリ土類金属の水酸化物を添加しないと、この湿式粉砕が効率的に実施できなくなる。この原因は定かでないが、上記水酸化物を添加する事により、ジルコニア粉末同士の凝集力を低下するためと考えられる。 If an alkali metal and / or alkaline earth metal hydroxide is not added to the zirconium salt aqueous solution during the synthesis of the hydrated zirconia sol, this wet pulverization cannot be carried out efficiently. Although this cause is not certain, it is considered that the cohesive strength between the zirconia powders is reduced by adding the hydroxide.
直径が３ｍｍよりも大きいジルコニアボールを用いて湿式粉砕すると、平均粒径が０．６μｍよりも大きく、かつ、粒径分布の累積カーブにおける粒径１μｍ及び２μｍにおいて、粒子の占める割合がそれぞれ９５％未満、１００％未満のものとなって、本発明のジルコニア微粉末が得られにくい。より好ましいジルコニアボールの直径は２ｍｍ以下である。粉砕機器としては、振動ミル，連続式媒体撹拌ミルを用いればよい。また、粉砕条件は、機種により異なるが、振動ミルの場合、スラリー濃度３０〜６０ｗｔ％，５〜３０時間がよく、媒体撹拌ミルの場合、スラリー濃度３０〜６０ｗｔ％，１０〜３０時間が最適である。粉砕する前に、仮焼粉を水洗処理、あるいは稀薄なアンモニア水で洗浄処理すると、ジルコニウム塩原料に由来する、焼結を阻害する微量の不純物が除去されるので、焼結性を向上させるのに効果的である。 When wet pulverization is performed using zirconia balls having a diameter larger than 3 mm, the average particle size is larger than 0.6 μm, and the proportion of the particles is 95% in the cumulative particle size distribution curve of 1 μm and 2 μm, respectively. It becomes difficult to obtain the zirconia fine powder of the present invention. A more preferable diameter of the zirconia ball is 2 mm or less. As a grinding device, a vibration mill or a continuous medium stirring mill may be used. The grinding conditions vary depending on the model, but in the case of a vibration mill, the slurry concentration is 30 to 60 wt% and 5 to 30 hours is good. In the case of a medium stirring mill, the slurry concentration is 30 to 60 wt% and 10 to 30 hours is optimal. is there. Washing the calcined powder with water or dilute ammonia water before pulverization removes a small amount of impurities that hinder sintering, which is derived from the zirconium salt raw material, thus improving the sinterability. It is effective.
必要に応じて、添加物を含むジルコニア微粉末を得る場合には、水和ジルコニアゾルに添加物を加えればよく、あるいは仮焼粉に添加物を加えて湿式粉砕すればよい。添加物の陽イオンがアルミニウムである原料化合物としては、アルミナ，水和アルミナ，アルミナゾル，水酸化アルミニウム，塩化アルミニウム，硝酸アルミニウム，硫酸アルミニウムなどを挙げることができる。陽イオンが珪素である原料化合物としては、シリカ、シリカゾル、ケイ酸などが挙げられる。また、陽イオンがゲルマニウムである原料化合物としては、酸化ゲルマニウム，水酸化ゲルマニウムなどを挙げることができる。 If necessary, when obtaining a zirconia fine powder containing an additive, the additive may be added to the hydrated zirconia sol, or the additive may be added to the calcined powder and wet pulverized. Examples of the raw material compound in which the cation of the additive is aluminum include alumina, hydrated alumina, alumina sol, aluminum hydroxide, aluminum chloride, aluminum nitrate, and aluminum sulfate. Examples of the raw material compound whose cation is silicon include silica, silica sol, and silicic acid. Examples of the raw material compound whose cation is germanium include germanium oxide and germanium hydroxide.
本発明で得られるジルコニア微粉末をスラリーにして噴霧乾燥することによりジルコニア顆粒が得られ、その粒径は３０〜８０μｍ、軽装嵩密度が１．１０〜１．４０ｇ／ｃｍ３となる。顆粒の製造方法については、特に限定されないが、例えば、特開平１０−１９４７４３に記載の方法により、本発明で得られるジルコニア微粉末からジルコニア顆粒を製造することが可能である。 The zirconia fine powder obtained in the present invention is made into a slurry and spray-dried to obtain zirconia granules having a particle size of 30 to 80 μm and a light bulk density of 1.10 to 1.40 g / cm 3 . Although it does not specifically limit about the manufacturing method of a granule, For example, it is possible to manufacture a zirconia granule from the zirconia fine powder obtained by this invention by the method of Unexamined-Japanese-Patent No. 10-194743.
本発明のジルコニア微粉末は、０．２μｍ未満の微粒子がなく、１μｍ以上の粗粒の比率が低減され、主要な粒径分布が１μｍ以下に制御された粉末であるため、従来の微粉末に比べて成形性及び低温焼結性が著しく改善され、さらに焼結体にしたときの品質の信頼性に優れている。 The zirconia fine powder of the present invention is a powder in which there are no fine particles of less than 0.2 μm, the ratio of coarse particles of 1 μm or more is reduced, and the main particle size distribution is controlled to 1 μm or less. Compared with this, the moldability and low-temperature sinterability are remarkably improved, and the quality of the sintered body is excellent in reliability.
以下、実施例により本発明を具体的に説明するが、本発明はこれらの実施例に何等限定されるものではない。 EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these Examples at all.
例中、水和ジルコニアゾルの平均粒径は、光子相関法による粒度分布測定装置により求めた。ジルコニア微粉末の平均粒径は、マイクロトラック粒度分布計（Ｈｏｎｅｙｗｅｌｌ社製，９３２０−ＨＲＡ）を用いて測定した。試料の前処理条件としては、粉末を蒸留水に懸濁させ、超音波ホモジナイザー（日本精機製作所製，ＵＳ−１５０Ｔ）を用いて３分間分散させた。ＸＲＤ測定により求められる単斜晶相率は数式１より算出した（いずれの例においても、立方晶は含まれていなかった）。また、ジルコニア顆粒の平均粒径は、ふるい分け試験方法によって求めた。 In the examples, the average particle size of the hydrated zirconia sol was determined by a particle size distribution measuring apparatus using a photon correlation method. The average particle size of the zirconia fine powder was measured using a Microtrac particle size distribution meter (manufactured by Honeywell, 9320-HRA). As sample pretreatment conditions, the powder was suspended in distilled water and dispersed using an ultrasonic homogenizer (Nippon Seiki Seisakusho, US-150T) for 3 minutes. The monoclinic phase ratio determined by XRD measurement was calculated from Equation 1 (in all examples, cubic crystals were not included). Moreover, the average particle diameter of the zirconia granule was calculated | required with the screening test method.
原料粉末の成形は、金型プレスにより成形圧力７００ｋｇｆ／ｃｍ２で行い、得られた成形体は所定温度（保持時間２時間）に設定して焼結させた。得られた焼結体の相対密度は、アルキメデス法で測定し、理論密度を６．０８ｇ／ｃｍ３として算出した。焼結体の強度は、３点曲げ測定法で評価した。また、劣化試験は、焼結体を１４０℃の熱水中に５時間浸漬させ、生成する単斜晶相の比率（単斜晶相率）を求めることによって評価した。単斜晶相率は、浸漬処理した焼結体についてＸＲＤ測定を行い、ジルコニア微粉末の単斜晶相率と同様の算出方法で、数式１により求めた。
The raw material powder was molded by a mold press at a molding pressure of 700 kgf / cm 2 , and the obtained molded body was sintered at a predetermined temperature (holding time 2 hours). The relative density of the obtained sintered body was measured by Archimedes method, and the theoretical density was calculated as 6.08 g / cm 3 . The strength of the sintered body was evaluated by a three-point bending measurement method. The deterioration test was evaluated by immersing the sintered body in 140 ° C. hot water for 5 hours and determining the ratio of the monoclinic phase to be formed (monoclinic phase ratio). The monoclinic phase rate was obtained by
実施例１
０．４モル／リットルのオキシ塩化ジルコニウム水溶液に水酸化カリウム水溶液を添加して、モル濃度比が［ＯＨ］／［Ｚｒ］＝０．０２の水溶液を調製した。この溶液を還流器付きフラスコ中で攪拌しながら加水分解反応を煮沸温度で３５０時間行った。得られた水和ジルコニアゾルの反応率は９９％であった。この水和ジルコニアゾルに塩化イットリウムをイットリア濃度が３モル％になるように添加して乾燥させ、１１００℃の温度で２時間仮焼した。得られた仮焼粉を水洗処理したあとに、アルミナ粉末をアルミナ含有量が０．２５重量％になるように添加し、さらに蒸留水を加えてジルコニア濃度４５重量％のスラリーにした。このスラリーを直径２ｍｍのジルコニアボールを用いて、振動ミルで８時間粉砕して乾燥させた。得られたジルコニア微粉末のＢＥＴ比表面積，平均粒径，粒径０．２μｍ，１μｍ及び２μｍでの粒子の占める割合，単斜晶相率の値を表１に示す。
Example 1
A potassium hydroxide aqueous solution was added to a 0.4 mol / liter zirconium oxychloride aqueous solution to prepare an aqueous solution having a molar concentration ratio of [OH] / [Zr] = 0.02. While stirring this solution in a flask equipped with a reflux condenser, the hydrolysis reaction was carried out at the boiling temperature for 350 hours. The reaction rate of the obtained hydrated zirconia sol was 99%. To this hydrated zirconia sol, yttrium chloride was added to a yttria concentration of 3 mol%, dried, and calcined at a temperature of 1100 ° C. for 2 hours. After the obtained calcined powder was washed with water, alumina powder was added so that the alumina content was 0.25 wt%, and distilled water was further added to make a slurry having a zirconia concentration of 45 wt%. This slurry was pulverized with a vibration mill for 8 hours using zirconia balls having a diameter of 2 mm and dried. Table 1 shows values of the BET specific surface area, average particle diameter, particle diameter of 0.2 μm, 1 μm and 2 μm, and monoclinic phase ratio of the obtained zirconia fine powder.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０℃の条件で焼結させた。得られた焼結体の相対密度，曲げ強度，劣化試験後の単斜晶相率を表２に示す。劣化試験後の単斜晶相率が０％であり、極めて劣化しにくい焼結体であることが確認された。また、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1350 ° C. Table 2 shows the relative density, bending strength, and monoclinic phase rate after the deterioration test of the obtained sintered body. The monoclinic phase rate after the deterioration test was 0%, and it was confirmed that the sintered body was extremely difficult to deteriorate. Further, when an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
実施例２
実施例１の水和ジルコニアゾルに蒸留水を加えて、ジルコニア換算濃度０．３モル／リットルの溶液を調製した。これを出発溶液に用いて、溶液の５体積％を反応槽から間欠的に排出し、かつ、溶液の体積が一定に保たれるように、その排出量と同量の０．３モル／リットルの水酸化ナトリウム水溶液を添加したオキシ塩化ジルコニウム水溶液（［ＯＨ］／［Ｚｒ］＝０．０２）を３０分毎に反応槽に供給しながら煮沸温度で加水分解反応を２００時間行った。反応槽から排出された水和ジルコニアゾルの反応率は９９％であった。この水和ジルコニアゾルに、塩化イットリウムをイットリア濃度が３モル％になるように添加して乾燥させ、１０９０℃の温度で２時間仮焼した。得られた仮焼粉を水洗処理したあとに、蒸留水を加えてジルコニア濃度４５重量％のスラリーにした。このスラリーを直径２ｍｍのジルコニアボールを用いて、振動ミルで２４時間粉砕して乾燥させた。得られたジルコニア微粉末の特性を表１に示す。また、ジルコニア微粉末の粒径分布（頻度及び累積曲線）を図１に示す。
Example 2
Distilled water was added to the hydrated zirconia sol of Example 1 to prepare a solution having a zirconia equivalent concentration of 0.3 mol / liter. Using this as a starting solution, 5% by volume of the solution is intermittently discharged from the reaction vessel, and 0.3 mol / liter of the same amount as the discharged amount so that the volume of the solution is kept constant. Hydrolysis reaction was carried out at boiling temperature for 200 hours while supplying an aqueous zirconium oxychloride solution ([OH] / [Zr] = 0.02) to which a sodium hydroxide aqueous solution was added to the reaction vessel every 30 minutes. The reaction rate of the hydrated zirconia sol discharged from the reaction vessel was 99%. To this hydrated zirconia sol, yttrium chloride was added to a yttria concentration of 3 mol%, dried, and calcined at a temperature of 1090 ° C. for 2 hours. The obtained calcined powder was washed with water, and distilled water was added to make a slurry having a zirconia concentration of 45% by weight. This slurry was pulverized for 24 hours with a vibration mill using zirconia balls having a diameter of 2 mm and dried. The characteristics of the obtained zirconia fine powder are shown in Table 1. The particle size distribution (frequency and cumulative curve) of the zirconia fine powder is shown in FIG.
次いで、上記で得られたジルコニア微粉末をプレス成形し１４００℃の条件で焼結させた。得られた焼結体の特性を表２に示す。赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1400 ° C. Table 2 shows the characteristics of the obtained sintered body. When an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
実施例３
仮焼粉を水洗処理したあとに、アルミナゾルをアルミナ含有量が０．３重量％になるように添加した以外は、実施例２と同様の条件でジルコニア微粉末を得た。ジルコニア微粉末の特性を表１に示す。
Example 3
A zirconia fine powder was obtained under the same conditions as in Example 2, except that after the calcined powder was washed with water, alumina sol was added so that the alumina content was 0.3 wt%. The characteristics of the zirconia fine powder are shown in Table 1.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０℃の条件で焼結させた。得られた焼結体の特性を表２に示す。劣化試験後の単斜晶相率が０％であり、極めて劣化しにくい焼結体であることが確認された。また、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1350 ° C. Table 2 shows the characteristics of the obtained sintered body. The monoclinic phase rate after the deterioration test was 0%, and it was confirmed that the sintered body was extremely difficult to deteriorate. Further, when an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
実施例４
アルミナゾルの代りに、酸化ゲルマニウムを０．５重量％添加した以外は、実施例２と同様の条件でジルコニア微粉末を得た。ジルコニア微粉末の特性を表１に示す。
Example 4
Zirconia fine powder was obtained under the same conditions as in Example 2 except that 0.5% by weight of germanium oxide was added instead of alumina sol. The characteristics of the zirconia fine powder are shown in Table 1.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０℃の条件で焼結させた。得られた焼結体の特性を表２に示す。劣化試験後の単斜晶相率が０％であり、極めて劣化しにくい焼結体であることが確認された。また、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1350 ° C. Table 2 shows the characteristics of the obtained sintered body. The monoclinic phase rate after the deterioration test was 0%, and it was confirmed that the sintered body was extremely difficult to deteriorate. Further, when an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
実施例５
アルミナゾルの代りに、アルミナゾルをアルミナ含有量０．２５重量％及び酸化ゲルマニウムを０．２５重量％添加した以外は、実施例３と同様の条件でジルコニア微粉末を得た。ジルコニア微粉末の特性を表１に示す。
Example 5
A zirconia fine powder was obtained under the same conditions as in Example 3 except that alumina content was 0.25 wt% and germanium oxide was added 0.25 wt% instead of alumina sol. The characteristics of the zirconia fine powder are shown in Table 1.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３００℃の条件で焼結させた。得られた焼結体の特性を表２に示す。劣化試験後の単斜晶相率が０％であり、極めて劣化しにくい焼結体であることが確認された。また、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered at 1300 ° C. Table 2 shows the characteristics of the obtained sintered body. The monoclinic phase rate after the deterioration test was 0%, and it was confirmed that the sintered body was extremely difficult to deteriorate. Further, when an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
実施例６
アルミナゾルの代りに、アルミナゾルをアルミナ含有量０．１５重量％及びシリカゾルを０．１５重量％添加した以外は、実施例３と同様の条件でジルコニア微粉末を得た。ジルコニア微粉末の特性を表１に示す。
Example 6
Zirconia fine powder was obtained under the same conditions as in Example 3 except that alumina content was 0.15 wt% and silica sol was 0.15 wt% instead of alumina sol. The characteristics of the zirconia fine powder are shown in Table 1.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０℃の条件で焼結させた。得られた焼結体の特性を表２に示す。劣化試験後の単斜晶相率が０％であり、極めて劣化しにくい焼結体であることが確認された。また、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1350 ° C. Table 2 shows the characteristics of the obtained sintered body. The monoclinic phase rate after the deterioration test was 0%, and it was confirmed that the sintered body was extremely difficult to deteriorate. Further, when an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
実施例７
実施例３で得られたジルコニア微粉末を水に分散させてスラリー濃度５０％のジルコニアスラリーを得、このスラリーに増粘剤を添加して粘度調整を行ったあとに噴霧造粒を実施した。得られたジルコニア顆粒の平均粒径が５５μｍ、軽装嵩密度が１．２０ｇ／ｃｍ３であった。
Example 7
The zirconia fine powder obtained in Example 3 was dispersed in water to obtain a zirconia slurry having a slurry concentration of 50%. After the viscosity was adjusted by adding a thickener to this slurry, spray granulation was performed. The obtained zirconia granules had an average particle size of 55 μm and a light bulk density of 1.20 g / cm 3 .
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０℃の条件で焼結させた。得られた焼結体の特性を表２に示す。劣化試験後の単斜晶相率が０％であり、極めて劣化しにくい焼結体であることが確認された。また、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れは観察されなかった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1350 ° C. Table 2 shows the characteristics of the obtained sintered body. The monoclinic phase rate after the deterioration test was 0%, and it was confirmed that the sintered body was extremely difficult to deteriorate. Further, when an impregnation test with a red dye was performed, scratches and cracks due to lamination or the like were not observed on the surface of the sintered body.
比較例１
実施例１の仮焼温度を９００℃にする以外は、実施例１と同様の条件でジルコニア微粉末を得た。ジルコニア微粉末の特性を表１に示す。
Comparative Example 1
Zirconia fine powder was obtained under the same conditions as in Example 1 except that the calcining temperature in Example 1 was set to 900 ° C. The characteristics of the zirconia fine powder are shown in Table 1.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０℃の条件で焼結させた。得られた焼結体の特性を表２に示す。劣化試験後の単斜晶相率が０％であり劣化しにくい焼結体であることが確認されたが、曲げ強度が低く、かつ、赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れが観察され、成形しにくいものであることが分かった。 Subsequently, the zirconia fine powder obtained above was press-molded and sintered under the condition of 1350 ° C. Table 2 shows the characteristics of the obtained sintered body. It was confirmed that the monoclinic phase ratio after the deterioration test was 0% and it was a sintered body that was not easily deteriorated. However, when the bending strength was low and an impregnation test with a red dye was performed, the surface of the sintered body was Scratches and cracks due to lamination and the like were observed, and it was found to be difficult to mold.
比較例２
実施例１の加水分解反応の時間を２００時間にする以外は、実施例１と同様の条件でジルコニア微粉末を得た。水和ジルコニアゾルの反応率は、８９％であった。得られたジルコニア微粉末の特性を表１に、粒径分布（頻度及び累積曲線）を図２にそれぞれ示す。
Comparative Example 2
A zirconia fine powder was obtained under the same conditions as in Example 1 except that the hydrolysis reaction time in Example 1 was changed to 200 hours. The reaction rate of the hydrated zirconia sol was 89%. The characteristics of the obtained fine zirconia powder are shown in Table 1, and the particle size distribution (frequency and cumulative curve) is shown in FIG.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０、１４００℃の条件でそれぞれ焼結させたが、得られた焼結体の相対密度が９７．３及び９８．６％と低いため、更に高い温度である１４５０℃で焼結させて得られた焼結体の特性を評価した。結果を表２に示す。赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れが観察されず、曲げ強度も高い値を示したが、劣化試験後の単斜晶相率が６５％であり、極めて劣化しやすい信頼性の低い焼結体であることが分かった。 Next, the zirconia fine powder obtained above was press-molded and sintered under the conditions of 1350 ° C. and 1400 ° C., respectively, but the relative density of the obtained sintered body was as low as 97.3 and 98.6%. Further, the characteristics of the sintered body obtained by sintering at 1450 ° C., which is a higher temperature, were evaluated. The results are shown in Table 2. When an impregnation test with a red dye was performed, scratches and cracks due to lamination and the like were not observed on the surface of the sintered body, and the bending strength was high, but the monoclinic phase ratio after the deterioration test was 65. %, And it was found that the sintered body was extremely low in reliability and easily deteriorated.
比較例３
実施例１のジルコニウム塩水溶液に水酸化カリウムを添加せず、かつ、仮焼温度を１２００℃にする以外は、実施例１と同様の条件でジルコニア微粉末を得た。得られたジルコニア微粉末の特性を表１に、粒径分布（頻度及び累積曲線）を図３にそれぞれ示す。
Comparative Example 3
Zirconia fine powder was obtained under the same conditions as in Example 1 except that potassium hydroxide was not added to the aqueous zirconium salt solution of Example 1 and the calcining temperature was 1200 ° C. The characteristics of the obtained fine zirconia powder are shown in Table 1, and the particle size distribution (frequency and cumulative curve) is shown in FIG.
次いで、上記で得られたジルコニア微粉末をプレス成形し１３５０〜１５００℃の条件でそれぞれ焼結させたが、得られた焼結体の相対密度が９８％よりも低いため、更に高い温度である１５５０℃で焼結させて得られた焼結体の特性を評価した。結果を表２に示す。赤色染料による含浸試験を行ったところ、焼結体表面にはラミネーション等に起因する傷やひび割れが観察され、曲げ強度も低く、更に劣化試験後の単斜晶相率が７８％であり、極めて劣化しやすい信頼性の低い焼結体であることが分かった。 Next, the zirconia fine powder obtained above was press-molded and sintered under the conditions of 1350-1500 ° C., but since the relative density of the obtained sintered body was lower than 98%, the temperature was higher. The characteristics of the sintered body obtained by sintering at 1550 ° C. were evaluated. The results are shown in Table 2. When an impregnation test with a red dye was performed, scratches and cracks due to lamination and the like were observed on the surface of the sintered body, the bending strength was low, and the monoclinic phase ratio after the deterioration test was 78%. It was found that the sintered body is easily deteriorated and has low reliability.
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|---|---|---|---|---|
| JP2009227507A (en) * | 2008-03-21 | 2009-10-08 | Sumitomo Osaka Cement Co Ltd | Zirconia composite microparticle, zirconia composite microparticle dispersion liquid, and method for producing zirconia composite microparticle |
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| JP6405699B2 (en) * | 2014-05-22 | 2018-10-17 | 東ソー株式会社 | Zirconia sintered body and manufacturing method thereof |
| JP6250242B1 (en) | 2016-03-30 | 2017-12-20 | 第一稀元素化学工業株式会社 | Zirconia fine powder and method for producing the same |
| JP2021088501A (en) * | 2019-04-25 | 2021-06-10 | 東ソー株式会社 | Sintered body, powder, and method for producing the same |
| CN113429202A (en) * | 2021-06-29 | 2021-09-24 | 乌鲁木齐市口腔医院 | Aluminum oxide and germanium oxide co-doped zirconia composite material and preparation method thereof |
| CN116409990A (en) * | 2021-12-31 | 2023-07-11 | 万华化学集团股份有限公司 | Zirconia ceramic and preparation method thereof |
Family Cites Families (20)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6291421A (en) * | 1985-10-18 | 1987-04-25 | Tokyo Inst Of Technol | Production of fine zirconium oxide particle |
| JPS62226815A (en) * | 1986-03-27 | 1987-10-05 | Nippon Shokubai Kagaku Kogyo Co Ltd | Production of zirconia base colloidal sol |
| JPS62226816A (en) * | 1986-03-28 | 1987-10-05 | Sumitomo Metal Mining Co Ltd | Production of fine zirconium oxide particle |
| JP2600341B2 (en) * | 1987-11-17 | 1997-04-16 | 日本合成ゴム株式会社 | Method for producing particulate metal compound |
| JPH0292825A (en) * | 1988-09-28 | 1990-04-03 | Sumitomo Chem Co Ltd | Production of zirconium oxide fine powder |
| JP3284244B2 (en) * | 1991-05-31 | 2002-05-20 | 東ソー株式会社 | Zirconium oxide powder and method for producing the same |
| JPH0543243A (en) * | 1991-08-08 | 1993-02-23 | Seiko Instr Inc | Method for regenerating scrap of zirconia compound after injection molding |
| JP3368507B2 (en) * | 1991-11-06 | 2003-01-20 | 東ソー株式会社 | Zirconia powder and method for producing the same |
| JPH06157037A (en) * | 1992-11-20 | 1994-06-03 | Tosoh Corp | Production of zirconium oxide powder |
| JPH07118016A (en) * | 1993-10-22 | 1995-05-09 | Etsuro Kato | Uniform-composition zirconia solid solution monodisperse fine globular powder and its production |
| JP4061679B2 (en) * | 1996-11-12 | 2008-03-19 | 東ソー株式会社 | Zirconia fine powder and method for producing the same |
| JPH1135323A (en) * | 1997-07-15 | 1999-02-09 | Nippon Shokubai Co Ltd | Zirconia powder and zirconia molded body |
| JP4253877B2 (en) * | 1998-10-01 | 2009-04-15 | 東ソー株式会社 | Zirconia fine powder and method for producing the same |
| FR2812630B1 (en) * | 2000-08-04 | 2002-10-04 | Rhodia Terres Rares | ZIRCONE IN THE FORM OF FINE POWDER, ZIRCONIUM HYDROXYCARBONATE AND PROCESSES FOR THEIR PREPARATION |
| JP4752098B2 (en) * | 2000-09-28 | 2011-08-17 | 東ソー株式会社 | Method for producing zirconia spherical sintered body |
| JP4254222B2 (en) * | 2002-12-05 | 2009-04-15 | 東レ株式会社 | Zirconia powder |
| JP4210533B2 (en) * | 2003-03-11 | 2009-01-21 | 第一工業製薬株式会社 | Sinterable tetragonal zirconia powder and method for producing the same |
| JP2004035403A (en) * | 2003-09-08 | 2004-02-05 | Nippon Shokubai Co Ltd | Zirconia-based powder and zirconia-based formed article |
| JP2005219934A (en) * | 2004-02-03 | 2005-08-18 | Dowa Mining Co Ltd | Zirconium oxide fine particle suspension and method of manufacturing the same |
| JP5356639B2 (en) * | 2005-03-04 | 2013-12-04 | 東ソー株式会社 | Zirconia fine powder and method for producing the same |
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