JP2010105884A - Tough and transparent alumina sintered compact, and manufacturing process and application for the same - Google Patents

Tough and transparent alumina sintered compact, and manufacturing process and application for the same Download PDF

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JP2010105884A
JP2010105884A JP2008281556A JP2008281556A JP2010105884A JP 2010105884 A JP2010105884 A JP 2010105884A JP 2008281556 A JP2008281556 A JP 2008281556A JP 2008281556 A JP2008281556 A JP 2008281556A JP 2010105884 A JP2010105884 A JP 2010105884A
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Koji Tsukuma
孝次 津久間
Isao Yamashita
勲 山下
Masayuki Kudo
正行 工藤
Naoki Shinozaki
直樹 篠崎
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Tosoh Corp
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Abstract

<P>PROBLEM TO BE SOLVED: To solve the problem that a transparent alumina sintered compact does not have a strength enough to be used as a dental material in particular for an orthodontic bracket, because of its low toughness. <P>SOLUTION: An alumina containing at least one kind of oxide selected from the group consisting of lanthanoid, zirconia, and yttria in a total amount of 100-1,000 ppm, and at least one kind selected from the group consisting of Group 1A alkali metal oxides, Group 2A alkaline earth metal oxides, SiO<SB>2</SB>, B<SB>2</SB>O<SB>3</SB>, P<SB>2</SB>O<SB>5</SB>and GeO<SB>2</SB>B in a total amount of 20-1,000 ppm is subjected to sintering under normal pressure and an HIP treatment at ≥1,550°C to obtain a sintered compact. The sintered compact has a fracture toughness of ≥4.5 MPa*m<SP>0.5</SP>and a light transmission of ≥60% to a visible light with a wavelength of 600 nm (sample thickness: 1 mm) and finds an excellent application for a dental material. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は靭性が高く、かつ透光性にも優れることにより歯列矯正ブラケットや歯科修復用ミルブランク等の歯科材料に適するアルミナ焼結体に関する。又透光性の高温劣化が少なく、ランプ管等にも適用できる。   The present invention relates to an alumina sintered body suitable for dental materials such as orthodontic brackets and dental restoration mill blanks because of its high toughness and excellent translucency. In addition, translucent high-temperature deterioration is small and it can be applied to lamp tubes and the like.

近年、歯科材料に透光性アルミナ焼結体が広く用いられており、透光性に優れ、なおかつ高強度、特に高靭性のアルミナ焼結体が望まれている。これまで靭性の高いアルミナ焼結体としては種々の焼結体が提案されているが、それらは透光性が十分なものではなかった。   In recent years, translucent alumina sintered bodies have been widely used for dental materials, and an alumina sintered body having excellent translucency and high strength, particularly high toughness, is desired. Until now, various sintered bodies have been proposed as high-toughness alumina sintered bodies, but they have not been sufficiently translucent.

例えば、数千ｐｐｍの不純物を含むバイヤー法アルミナ粉末を用いてなる異方粒成長した板状粒子を含むアルミナ焼結体が異方形状粒子のために高靭性化することが報告されている（特許文献１）。５〜８ＭＰａ・ｍ０．５の高い破壊靭性が報告されているが、焼結体の密度は３．９３〜３．９４ｇ／ｃｍ３（相対密度９９．０％）であり、透光性を発揮できる高密度（＞９９．８％）に達しておらず、透光性が十分ではなかった。 For example, it has been reported that an alumina sintered body containing plate-like particles grown anisotropically using a buyer's method alumina powder containing impurities of several thousand ppm is made tough due to the anisotropic shaped particles ( Patent Document 1). Although high fracture toughness of 5-8 MPa · m 0.5 has been reported, the density of the sintered body is 3.93 to 3.94 g / cm 3 (relative density 99.0%), and the translucency is high. The high density (> 99.8%) that can be exhibited was not reached, and the translucency was not sufficient.

アルミナ焼結体では、異方形状粒子が発達すると緻密化が進み難く、透光性が得難いことが知られており、異方成長を抑制するため、ＺｒＯ２、Ｙ２Ｏ３、Ｌａ２Ｏ３、ＭｇＯ等の粒成長抑制剤を添加することが知られている。これら抑制剤を添加した焼結体では粒子は等軸形状となり、１００％に近い高密度化が容易となることから、透光性アルミナが得られている（特許文献２〜８、非特許文献１）。しかし、従来のＺｒＯ２、Ｙ２Ｏ３、Ｌａ２Ｏ３、ＭｇＯ等の粒成長抑制剤を添加した焼結体では、異方形状粒子が形成されず、靭性が低いものしか得られていなかった。 In an alumina sintered body, it is known that when anisotropically shaped particles develop, densification hardly progresses and it is difficult to obtain translucency. In order to suppress anisotropic growth, ZrO 2 , Y 2 O 3 , La 2 O 3. It is known to add grain growth inhibitors such as MgO. In the sintered body to which these inhibitors are added, the particles have an equiaxed shape, and it is easy to increase the density close to 100%, so that translucent alumina is obtained (Patent Documents 2 to 8, Non-Patent Documents). 1). However, in the conventional sintered body to which a grain growth inhibitor such as ZrO 2 , Y 2 O 3 , La 2 O 3 , MgO is added, anisotropically shaped particles are not formed, and only those having low toughness are obtained. It was.

高純度アルミナ粉末を常圧焼結し、それをＨＩＰ処理で高密度化して、透光性を付与する方法が知られている（特許文献９〜１６）。この方法では、９９．９９％以上の高純度アルミナ粉末（又はＺｒＯ２、Ｙ２Ｏ３、Ｌａ２Ｏ３、ＭｇＯ等の粒成長抑制剤を添加したもの）による等軸形状粒子からなる透光性焼結体が得られている。しかし焼結粒子の形状が等軸であるため、いずれも靭性が低いものであった。 A method is known in which high-purity alumina powder is sintered under normal pressure and densified with HIP treatment to impart translucency (Patent Documents 9 to 16). In this method, translucent particles composed of equiaxed particles made of 99.99% or more of high-purity alumina powder (or added with a grain growth inhibitor such as ZrO 2 , Y 2 O 3 , La 2 O 3 , MgO). A sintered body is obtained. However, since the shape of the sintered particles is equiaxed, all of them have low toughness.

この様に、これまで高純度アルミナ、又はＺｒＯ２、Ｙ２Ｏ３、Ｌａ２Ｏ３、ＭｇＯ等の粒成長抑制剤を含むアルミナでは、たとえ熱間静水圧プレス（ＨＩＰ）処理しても、透光性と高い靭性を両立したアルミナ焼結体は得られていなかった。 Thus, in high-purity alumina or alumina containing a grain growth inhibitor such as ZrO 2 , Y 2 O 3 , La 2 O 3 , MgO, etc., even if hot isostatic pressing (HIP) treatment is used, An alumina sintered body having both translucency and high toughness has not been obtained.

特開平１１−１３６５号公報Japanese Patent Laid-Open No. 11-1365 米国特許第３０２６２１０号US Pat. No. 3,062,210 特開昭５３−１１１３１２号公報JP-A-53-111312 特開昭５６−１４００７２号公報JP-A-56-140072 特開昭５６−１６０３７４号公報JP 56-160374 A 特開平４−１９８０６０号公報Japanese Patent Laid-Open No. 4-198060 特開平６−３４０４６９号公報JP-A-6-340469 特開平９−２８６５号公報JP-A-9-2865 特開昭６３−２３６７５７号公報JP-A-63-236757 特開平３−１６８１４０号公報Japanese Patent Laid-Open No. 3-168140 特開平３−２６１６４８号公報Japanese Patent Laid-Open No. 3-261648 特開２００１−３２２８６６号公報JP 2001-322866 A 米国特許第６８７８４５６号US Pat. No. 6,878,456 米国特許第６６４８６３８号US Pat. No. 6,648,638 特開平２００６−８７９１５号JP 2006-87915 A 特表２００５−５３２２５０号公報JP 2005-532250 A Ｊ．Ｃｅｒａｍ．Ｓｏｃ．Ｊｐｎ．１０８［６］５５８−５６４（２０００）J. et al. Ceram. Soc. Jpn. 108 [6] 558-564 (2000)

本発明は高靭性でなおかつ透光性に優れるアルミナ焼結体を提供するものである。   The present invention provides an alumina sintered body having high toughness and excellent translucency.

従来、ＺｒＯ２、Ｙ２Ｏ３、Ｌａ２Ｏ３及びＭｇＯ等の粒成長抑制剤の存在下ではアルミナ粒子は異方形状とはならないとされてきたが、本発明者等はその様な粒子成長抑制剤と同時にＮａ２Ｏ，ＳｉＯ２等のガラス相形成剤を共存させると、１５５０℃以上の特定の温度領域での焼結温度において、アルミナ焼結粒子が異方粒成長を開始するために、焼結体の気孔の低減と高靭性化が可能となり、この様な焼結体では熱処理によって透光性の低下のない耐熱性にも優れる透光性アルミナ焼結体となることを見出し、本発明を完成するに到ったものである。 Conventionally, alumina particles have not been anisotropically shaped in the presence of grain growth inhibitors such as ZrO 2 , Y 2 O 3 , La 2 O 3, and MgO. When a glass phase forming agent such as Na 2 O or SiO 2 coexists with the growth inhibitor, the alumina sintered particles start anisotropic grain growth at a sintering temperature in a specific temperature range of 1550 ° C. or higher. In addition, the pores of the sintered body can be reduced and the toughness can be increased, and it has been found that such a sintered body becomes a translucent alumina sintered body that has excellent heat resistance without deterioration of translucency by heat treatment. The present invention has been completed.

以下、本発明の透光性アルミナ焼結体について説明する。   Hereinafter, the translucent alumina sintered body of the present invention will be described.

本発明の焼結体は、粒成長抑制剤としてランタノイド、ジルコニア及びイットリアの群から選ばれる少なくとも１種以上の酸化物を総量で１００〜１０００ｐｐｍ、ガラス相形成剤である１Ａ族アルカリ金属酸化物、２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５及びＧｅＯ２の群から選ばれる少なくとも１種以上を総量で２０〜１０００ｐｐｍ含有し、なおかつ破壊靭性が４．５ＭＰａ・ｍ０．５以上、波長６００ｎｍの可視光に対する全光線透過率（試料厚さ１ｍｍ）が６０％以上であるアルミナ焼結体である。 The sintered body of the present invention has a total amount of at least one oxide selected from the group of lanthanoids, zirconia and yttria as a grain growth inhibitor, 100 to 1000 ppm in total, a group 1A alkali metal oxide which is a glass phase forming agent, 2A group alkaline earth metal oxide, SiO 2 , B 2 O 3 , P 2 O 5 and at least one selected from the group of GeO 2 is contained in a total amount of 20 to 1000 ppm, and fracture toughness is 4.5 MPa · m Alumina sintered body having a total light transmittance (sample thickness of 1 mm) for visible light having a wavelength of 0.5 nm or more and a wavelength of 600 nm of 60% or more.

本発明の焼結体は、ランタノイド、ジルコニア及びイットリアの群から選ばれる少なくとも１種以上の酸化物と、Ｎａ２Ｏ等の１Ａ族アルカリ金属酸化物、２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５、ＧｅＯ２の中から選ばれる少なくとも１種以上の酸化物との両方を含有することを必須とし、総含有量は前者が１００〜１０００ｐｐｍ、後者が２０〜１０００ｐｐｍである。 The sintered body of the present invention comprises at least one oxide selected from the group consisting of lanthanoids, zirconia and yttria, a group 1A alkali metal oxide such as Na 2 O, a group 2A alkaline earth metal oxide, SiO 2. , B 2 O 3 , P 2 O 5 , GeO 2 and at least one selected from oxides are essential, and the total content is 100 to 1000 ppm for the former and 20 to 20 for the latter. 1000 ppm.

本発明で用いるＮａ２Ｏ等の１Ａ族アルカリ金属酸化物、２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５、ＧｅＯ２はガラス相形成剤として働き、アルミナ粒子の異方成長を促進する。このうち、特にガラス相形成能力の高い酸化物はＮａ２Ｏ、Ｎａ２Ｏ＋ＳｉＯ２である。この効果は総含有量２０ｐｐｍ未満では発現せず、又１０００ｐｐｍを超えると焼結を阻害する。 1A group alkali metal oxides such as Na 2 O used in the present invention, 2A group alkaline earth metal oxides, SiO 2 , B 2 O 3 , P 2 O 5 , GeO 2 act as glass phase forming agents, and alumina particles Promote anisotropic growth. Among these, oxides with particularly high glass phase forming ability are Na 2 O and Na 2 O + SiO 2 . This effect is not exhibited when the total content is less than 20 ppm, and sintering is inhibited when the total content exceeds 1000 ppm.

本発明では上記の添加物と同時に粒成長抑制剤としてランタノイド、ジルコニア及びイットリアの群から選ばれる少なくとも１種以上の酸化物を用いるが、本発明でいうランタノイドの酸化物としては特にＬａ２Ｏ３のＬｕ２Ｏ３いずれかが好ましい。これらの添加物は前述の添加物によって進む異方性成長の発現する温度を制御し、これらの成分との組み合せによって初めて靭性と透光性の双方を満足する焼結体を得る効果を発揮する。添加量は総含有量１００〜１０００ｐｐｍで効果が特に顕著であり、１００ｐｐｍ未満では効果が薄れ、１０００ｐｐｍを超えると透光性の低下をもたらす。 In the present invention, at least one oxide selected from the group consisting of lanthanoid, zirconia and yttria is used as a grain growth inhibitor simultaneously with the above-mentioned additives, and the lanthanoid oxide referred to in the present invention is particularly La 2 O 3. Any of Lu 2 O 3 is preferred. These additives control the temperature at which anisotropic growth proceeds by the above-mentioned additives, and exhibit the effect of obtaining a sintered body that satisfies both toughness and translucency for the first time in combination with these components. . The effect is particularly remarkable when the total content is 100 to 1000 ppm. When the content is less than 100 ppm, the effect is reduced. When the content exceeds 1000 ppm, the translucency is lowered.

ＭｇＯは２Ａ族アルカリ土類金属酸化物であるが、ＭｇＯの添加効果は粒成長抑制剤として働くため、２Ａ族アルカリ土類金属酸化物にＭｇＯを用いる場合には、１Ａ族アルカリ金属酸化物、ＭｇＯ以外の２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５及びＧｅＯ２の群からさらに少なくとも１種以上の成分を添加することが必要であり、２Ａ族元素としてはＭｇＯ以外の酸化物を用いることがより好ましい。 MgO is a group 2A alkaline earth metal oxide. However, since the effect of adding MgO works as a grain growth inhibitor, when using MgO as the group 2A alkaline earth metal oxide, a group 1A alkali metal oxide, It is necessary to add at least one more component from the group of 2A group alkaline earth metal oxides other than MgO, SiO 2 , B 2 O 3 , P 2 O 5 and GeO 2 , More preferably, an oxide other than MgO is used.

本発明の焼結体は、破壊靱性は４．５ＭＰａ・ｍ０．５以上であり、特に５ＭＰａ・ｍ０．５以上、さらには６ＭＰａ・ｍ０．５以上であることが好ましい。 Sintered body of the present invention, fracture toughness is at 4.5 MPa · m 0.5 or more, in particular 5 MPa · m 0.5 or more, and further preferably not 6 MPa · m 0.5 or more.

本発明の焼結体の曲げ強度は特に規定されないが、高いことが好ましく、特に３５０ＭＰａ以上であることが好ましい。曲げ強度は破壊靱性が高くなると低下する傾向があり、破壊靱性８〜１０ＭＰａ・ｍ０．５では３５０〜４００ＭＰａとなる。ここでの破壊靱性、曲げ強度の評価方法はいずれもＪＩＳに規定される方法による。 The bending strength of the sintered body of the present invention is not particularly specified, but is preferably high, and particularly preferably 350 MPa or more. The bending strength tends to decrease as the fracture toughness increases, and the fracture toughness of 8 to 10 MPa · m 0.5 is 350 to 400 MPa. The evaluation methods of fracture toughness and bending strength here are both according to the methods specified in JIS.

本発明の焼結体は試料厚み１ｍｍにおいて、６００ｎｍの可視光に対して６０％以上の高い全光線透過率を有するものであり、特に６５％以上、さらには７０％以上であることが好ましい。   The sintered body of the present invention has a high total light transmittance of 60% or more with respect to visible light of 600 nm at a sample thickness of 1 mm, particularly preferably 65% or more, and more preferably 70% or more.

本発明の焼結体は焼結粒子に長軸長さが１０μｍ以上、アスペクト比１．５以上の異方性粒子を含むことが好ましい。焼結体を構成するアルミナ粒子の代表例を図１に示す。   The sintered body of the present invention preferably contains anisotropic particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more in the sintered particles. A representative example of alumina particles constituting the sintered body is shown in FIG.

異方性粒子のアスペクト比は、大きいほど破壊靭性が高まる。異方性粒子のアスペクト比は３以上であることが好ましい。異方性粒子の含量は２０ｖｏｌ％以上、さらには５０ｖｏｌ％以上であることが好ましい。異方性粒子の含量が増加するほど、焼結体の破壊靱性は増加する。ただし、異方性粒子の含有量が１００ｖｏｌ％になると、破壊靱性は１０ＭＰａ・ｍ０．５以上に達するが、曲げ強度が低下しやすくなるので、異方性粒子の含有量を過度に増加させる必要はない。 The larger the aspect ratio of the anisotropic particles, the higher the fracture toughness. The aspect ratio of the anisotropic particles is preferably 3 or more. The content of anisotropic particles is preferably 20 vol% or more, more preferably 50 vol% or more. As the content of anisotropic particles increases, the fracture toughness of the sintered body increases. However, when the content of anisotropic particles becomes 100 vol%, the fracture toughness reaches 10 MPa · m 0.5 or more, but the bending strength tends to decrease, so the content of anisotropic particles is excessively increased. There is no need.

本発明の異方性粒子は特に板状（異方性板状粒子）であることが好ましい。   The anisotropic particles of the present invention are particularly preferably plate-shaped (anisotropic plate-shaped particles).

本発明のアルミナ焼結体は、異方性粒子以外の焼結粒子は等軸形状粒子からなり、異方性粒子が破壊靱性向上に寄与する一方、等軸形状粒子は異方性粒子を結合する働きをし、強度維持に寄与する。   In the alumina sintered body of the present invention, the sintered particles other than the anisotropic particles are made of equiaxed particles, and the anisotropic particles contribute to the improvement of fracture toughness, while the equiaxed particles bind the anisotropic particles. To help maintain strength.

次に、本発明のアルミナ焼結体の製造法について説明する。   Next, the manufacturing method of the alumina sintered compact of this invention is demonstrated.

本発明のアルミナ焼結体は、ランタノイド、ジルコニア及びイットリアの群から選ばれる少なくとも１種以上の酸化物を総量で１００〜１０００ｐｐｍ、１Ａ族アルカリ金属酸化物、２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５及びＧｅＯ２の群から選ばれる少なくとも１種以上を総量で２０〜１０００ｐｐｍ含有するアルミナ粉末を成形後、常圧焼結した後、さらに熱間静水圧プレス（ＨＩＰ）処理することによって製造することができる。 The alumina sintered body of the present invention comprises at least one oxide selected from the group of lanthanoids, zirconia and yttria in a total amount of 100 to 1000 ppm, a group 1A alkali metal oxide, a group 2A alkaline earth metal oxide, SiO 2, B 2 O 3, P 2 O 5 and after molding the alumina powder containing 20~1000ppm in a total amount of at least one selected from the group consisting of GeO 2, after pressureless sintering, further hot isostatic pressing (HIP) It can manufacture by processing.

前者の粒成長抑制剤（ＺｒＯ２等）、及び後者のガラス相形成剤（１Ａ族アルカリ金属酸化物等）の添加方法は特に限定されないが、例えば、アルミナ粉末に添加し、混合・粉砕等によって分散させればよい。また酸化物粉末として添加しても良いが、焼成によって酸化物になる前駆体として添加してもよい。例えば、ＺｒＯ２の場合、ＺｒＯＣｌ２或いはＺｒＯ（ＮＯ３）２を水溶液とし、アルミナ粉末と湿式混合した後、乾燥・焼成する方法が例示できる。同様にＮａ２Ｏの場合、Ｎａ２ＣＯ３或いはＮａＣｌ等の水溶性塩を用いることができる。 The method of adding the former grain growth inhibitor (such as ZrO 2 ) and the latter glass phase forming agent (such as a group 1A alkali metal oxide) is not particularly limited. For example, it may be added to alumina powder, mixed, pulverized, etc. What is necessary is just to disperse. Moreover, although it may be added as an oxide powder, it may be added as a precursor that becomes an oxide by firing. For example, in the case of ZrO 2, a method in which ZrOCl 2 or ZrO (NO 3 ) 2 is made into an aqueous solution, wet-mixed with alumina powder, and then dried and fired can be exemplified. Similarly, in the case of Na 2 O, a water-soluble salt such as Na 2 CO 3 or NaCl can be used.

本発明の方法における成形方法も特に限定されるものではなく、金型プレス、ラバープレス、スリップキャスティング、射出成形等あらゆる方法が適用できる。   The molding method in the method of the present invention is not particularly limited, and any method such as a die press, rubber press, slip casting, injection molding, etc. can be applied.

本発明における焼結は、常圧焼結した後、さらに熱間静水圧プレス（ＨＩＰ）処理を実施する。   In the sintering in the present invention, after performing normal pressure sintering, a hot isostatic pressing (HIP) treatment is further performed.

常圧焼結は、大気、酸素、真空等の雰囲気中で、温度１２５０℃〜１４５０℃で実施することが好ましい。常圧焼結では、焼結体を次のＨＩＰ処理を施すに必要な密度（理論密度の約９５％）まで緻密化する。常圧焼結後の密度が９５％以下では、ＨＩＰ処理の圧力媒体ガスが焼結体内部に浸透し、気孔の除去が十分に達成されず、透光性が得られない。一方、常圧焼結時において焼結温度が高すぎると、気孔が焼結粒子内に取り込まれる現象（粒内気孔）が起こり易く、その様な気孔はＨＩＰ処理によって除去され難い。したがって、理論密度の９５％以上及び粒内気孔の生成抑止の観点から、常圧焼結は温度１２５０〜１４５０℃が好ましい。   The normal pressure sintering is preferably performed at a temperature of 1250 ° C. to 1450 ° C. in an atmosphere such as air, oxygen, and vacuum. In the normal pressure sintering, the sintered body is densified to the density necessary for the next HIP treatment (about 95% of the theoretical density). When the density after atmospheric pressure sintering is 95% or less, the pressure medium gas of the HIP treatment penetrates into the sintered body, and the removal of pores is not sufficiently achieved, so that the translucency cannot be obtained. On the other hand, if the sintering temperature is too high during normal pressure sintering, a phenomenon in which pores are taken into the sintered particles (intragranular pores) is likely to occur, and such pores are difficult to remove by HIP treatment. Therefore, from the viewpoint of 95% or more of the theoretical density and suppression of formation of intragranular pores, the normal pressure sintering is preferably performed at a temperature of 1250 to 1450 ° C.

本発明の方法におけるＨＩＰ処理は焼結体中の残留気孔を消滅させ、透光性を付与する目的でなされる。処理温度は１２００℃以上、処理圧力は５０ＭＰａ以上が好ましく、特に１５５０〜１７００℃が好ましい。本発明の組成では特に１５５０℃以上で焼結粒子の異方成長が始まり、異方性粒子を含む組織形成が進行する。従ってＨＩＰ処理温度は１５５０〜１６００℃の温度が特に好ましい。一方、１７００℃を超えると異方成長が進みすぎ、粒子が粗大になり、曲げ強度が低下し易い。   The HIP treatment in the method of the present invention is performed for the purpose of eliminating residual pores in the sintered body and imparting translucency. The treatment temperature is preferably 1200 ° C. or more, and the treatment pressure is preferably 50 MPa or more, particularly preferably 1550 to 1700 ° C. In the composition of the present invention, the anisotropic growth of sintered particles starts particularly at 1550 ° C. or higher, and the formation of a structure including anisotropic particles proceeds. Accordingly, the HIP treatment temperature is particularly preferably 1550 to 1600 ° C. On the other hand, when the temperature exceeds 1700 ° C., anisotropic growth proceeds excessively, the grains become coarse, and the bending strength tends to decrease.

ＨＩＰ処理における圧力媒体としては通常用いられるアルゴンガスを用いることができる。その他のガス、例えば窒素、酸素なども適用可能である。   As a pressure medium in the HIP process, a commonly used argon gas can be used. Other gases such as nitrogen and oxygen are also applicable.

ＨＩＰ処理の圧力は５０ＭＰａ以上が好ましく、通常適用される１００〜２００ＭＰａであれば十分の効果が得られる。   The pressure of the HIP treatment is preferably 50 MPa or more, and a sufficient effect can be obtained if it is normally applied 100 to 200 MPa.

本発明では、粒成長抑制剤とガラス相形成剤とを共存させることにより、１５５０℃までのＨＩＰ処理では微細な等方性粒子が支配的であるが、それ以上の温度から急激に異方形状粒子が出現するため、透光性に必要な気孔低減と、高靭性化に必要な異方性粒子の形成が理想的に進行することを見出した。   In the present invention, fine isotropic particles are dominant in the HIP treatment up to 1550 ° C. by coexistence of the grain growth inhibitor and the glass phase forming agent, but the anisotropic shape rapidly increases from the temperature higher than that. It has been found that since particles appear, pore formation necessary for translucency and formation of anisotropic particles necessary for high toughness proceed ideally.

本発明の方法で用いるアルミナ粉末は特に限定されないが、純度９９．９９％以上、比表面積５〜２０ｍ２／ｇ、１μｍ以下の微粒子比率９０ｖｏｌ％以上の微細粒子からなるものが好ましい。本発明の焼結体原料として、微粒子比率は特に重要で、９０ｖｏｌ％以下では焼結温度が高くなる。本発明では、各種添加物を添加して焼結するが、アルミナ粉末そのものに高純度のものを用いることにより、各種成分の添加の効果にばらつきがなく、均質な品質の焼結体が得られる。 The alumina powder used in the method of the present invention is not particularly limited, but is preferably composed of fine particles having a purity of 99.99% or more, a specific surface area of 5 to 20 m 2 / g, and a fine particle ratio of 1 vol. The fine particle ratio is particularly important as the raw material of the sintered body of the present invention, and the sintering temperature becomes high at 90 vol% or less. In the present invention, various additives are added and sintered. By using high-purity alumina powder itself, there is no variation in the effect of adding various components, and a homogeneous quality sintered body can be obtained. .

本発明のアルミナ焼結体は高靭性と透光性を兼ね備えており、歯科材料、特に歯列矯正ブラケット又は歯科修復用ミルブランクとしての用途に適している。特に、耐熱性に優れており、熱処理後に透光性の低下がないため、加熱コーティング、ガラス融着等の高温二次処理が可能である。   The alumina sintered body of the present invention has high toughness and translucency, and is suitable for use as a dental material, particularly as an orthodontic bracket or a dental restoration blank. In particular, since it is excellent in heat resistance and does not deteriorate translucency after heat treatment, high temperature secondary treatment such as heat coating and glass fusion is possible.

本発明のアルミナ焼結体は特に靭性が高いため、歯科材料に用いる上で、以下の様な利点もある。   Since the alumina sintered body of the present invention has particularly high toughness, there are the following advantages when used for dental materials.

ブラケットには矯正用ワイヤーから受ける捻り応力に耐える破壊抵抗力（トルク強度）が要求される。トルク強度は材料の破壊靭性によって決まるものであり、本発明の焼結体は高靭性であるため、高いトルク強度が獲得される。そのため、従来に比してよりコンパクトかつより複雑な形状からなるブラケットが設計でき、高機能セルフライゲーションブラケット等が可能になる。   The bracket is required to have a fracture resistance (torque strength) that can withstand the torsional stress received from the straightening wire. The torque strength is determined by the fracture toughness of the material. Since the sintered body of the present invention has high toughness, high torque strength is obtained. Therefore, it is possible to design a bracket having a more compact and more complicated shape than the conventional one, and a high-function self-ligation bracket or the like is possible.

クラウン、ブリッジ等の歯科修復材料には噛み合わせ応力に対する破壊抵抗力と自然歯に近い審美性を出すための透光性が要求される。この用途に利用されている従来のアルミナ焼結体の破壊靭性は４ＭＰａ・ｍ０．５以下であり、又透光性にも乏しい。本発明の焼結体は高い破壊靭性と高い透光性を兼備しているので、審美性の増したクラウン、ブリッジ等を可能にする。近年、クラウン、ブリッジ等は焼結体をＣＡＤ−ＣＡＭ方式で加工して製造され、この焼結体披加工材をミルブランクと称している。本発明の焼結体は高靭性であるため、加工時のチッピング、欠けの発生がない、優れたミルブランクとなる。 Dental restoration materials such as crowns and bridges are required to have fracture resistance against biting stress and translucency to produce aesthetics similar to natural teeth. The fracture toughness of the conventional alumina sintered body used for this purpose is 4 MPa · m 0.5 or less, and the translucency is poor. Since the sintered body of the present invention has both high fracture toughness and high translucency, crowns, bridges and the like with increased aesthetics can be realized. In recent years, crowns, bridges, and the like are manufactured by processing a sintered body by a CAD-CAM method, and this sintered body material is called a mill blank. Since the sintered body of the present invention has high toughness, it is an excellent mill blank without chipping or chipping during processing.

本発明のアルミナ焼結体は透光性が高く、なおかつ従来のものに比べて高い靭性を有しているため、特に歯科用途に適している。また、熱処理によって透光性の低下がないため、加熱コーティング、加熱融着などの二次処理に対して高い耐久性を有する。さらに二次処理によって、ブラケットのスロット部分に金属、ガラス等の被膜を形成し、矯正ワイヤーとの摩擦が軽減されるため、従来にない高機能のブラケット、クラウン・ブリッジ等を提供することができる。   Since the alumina sintered body of the present invention has high translucency and has high toughness as compared with the conventional one, it is particularly suitable for dental use. Further, since there is no decrease in translucency due to heat treatment, it has high durability against secondary treatment such as heat coating and heat fusion. Furthermore, the secondary treatment forms a coating of metal, glass, etc. on the slot portion of the bracket and reduces friction with the straightening wire, so that it is possible to provide a highly functional bracket, crown bridge, etc. .

以下、実施例及び比較例により本発明を具体的に説明するが、本発明はこれら実施例に限定されるものではない。   EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited to these Examples.

本発明の焼結体の評価方法を以下に説明する。
（１）破壊靭性
破壊靭性試験はＪＩＳＲ１６０７「ファインセラミックスの破壊靱性試験方法」に基づきＳＥＰＢ法により測定した。５本の平均値を採用した。
（２）曲げ強度
曲げ試験はＪＩＳＲ１６０１「ファインセラミックスの曲げ強さ試験方法」に基づき３点曲げ試験により測定し、１０本の平均値を採用した。
（３）全光線透過率
全光線透過率はＪＩＳＫ７１０５「プラスティックスの光学特性試験方法」およびＪＩＳＫ７３６１−１「プラスティック・透明材料の全光線透過率の試験方法」に基づき、ダブルビーム方式の分光光度計（日本分光株式会社製、Ｖ−６５０型）で測定した。測定試料は焼結体厚みを１ｍｍに加工し表面粗さＲａ＝０．０２μｍ以下に両面鏡面研磨したものを用いた。光源（重水素ランプおよびハロゲンランプ）より発生した光を試料に透過および散乱させ積分球を用いて全光線透過量を測定した。測定波長領域は２００〜８００ｎｍの領域で測定し、本件での全光線透過率は、可視光線領域の６００ｎｍの波長での透過率とした。
（４）粒子の長軸長さ、アスペクト比、異方性粒子の割合
焼結体を鏡面研磨し、ケミカルエッチングにより粒界を際立たせ、金コーティングしたものを走査型電子顕微鏡或いは光学顕微鏡写真で観察し、この写真の画像解析より算出した。各粒子を矩形近似し、長辺を長軸長さ、短辺を短軸長さとして測定した。長軸長さを短軸長さで除した値をアスペクト比とした。長軸長さ１０μｍ以上、アスペクト比１．５以上の粒子をピックアップし、その粒子が占める面積から体積比率を求めた。その際の測定粒子数は１００個以上とした。なお、ケミカルエッチングは焼結体を８０℃の過飽和ホウ酸ナトリウム溶液に浸して表面に付着させた後、９００℃で０．５時間加熱し冷却後、塩酸溶液で洗浄する方法で行った。
（５）焼結体密度
焼結体の水中での重量を測定するアルキメデス法によって求めた。相対密度は理論密度を３．９８ｇ／ｃｍ３として計算した。 The method for evaluating the sintered body of the present invention will be described below.
(1) Fracture toughness The fracture toughness test was measured by the SEPB method based on JIS R1607 “Fracture toughness test method for fine ceramics”. An average value of 5 was adopted.
(2) Bending strength The bending test was measured by a three-point bending test based on JIS R1601 “Bending strength test method of fine ceramics”, and an average value of 10 pieces was adopted.
(3) Total light transmittance The total light transmittance is a double beam spectrophotometer based on JISK7105 “Testing method for optical properties of plastics” and JISK7361-1 “Testing method for total light transmittance of plastics and transparent materials”. (Measured by JASCO Corporation, V-650 type). The measurement sample was processed to have a sintered body thickness of 1 mm and mirror-polished to a surface roughness Ra = 0.02 μm or less. The light emitted from the light source (deuterium lamp and halogen lamp) was transmitted and scattered through the sample, and the total light transmission amount was measured using an integrating sphere. The measurement wavelength region was measured in the region of 200 to 800 nm, and the total light transmittance in this case was the transmittance at a wavelength of 600 nm in the visible light region.
(4) Long axis length of particles, aspect ratio, proportion of anisotropic particles The sintered body is mirror-polished, the grain boundary is made to stand out by chemical etching, and the gold coating is shown in a scanning electron microscope or optical micrograph. Observed and calculated from image analysis of this photograph. Each particle was approximated to a rectangle, and the long side was measured as the long axis length and the short side was measured as the short axis length. The aspect ratio was obtained by dividing the major axis length by the minor axis length. Particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more were picked up, and the volume ratio was determined from the area occupied by the particles. The number of measured particles at that time was 100 or more. The chemical etching was performed by a method in which the sintered body was immersed in a supersaturated sodium borate solution at 80 ° C. and adhered to the surface, heated at 900 ° C. for 0.5 hours, cooled, and then washed with a hydrochloric acid solution.
(5) Density of sintered body The density was determined by Archimedes method for measuring the weight of the sintered body in water. The relative density was calculated with a theoretical density of 3.98 g / cm 3 .

実施例１〜３
純度９９．９９％以上、比表面積１４ｍ２／ｇ、１μｍ以下の微粒子比率１００ｖｏｌ％の高純度アルミナ粉末（大明化学工業製）、ジルコニア粉末（東ソー製３Ｙ（３モル％Ｙ２Ｏ３−９７モル％ＺｒＯ２））、Ｎａ２Ｏ、ＳｉＯ２等不純物を含有するワックス系熱可塑性樹脂を用い、アルミナ１０００ｇにジルコニア０．４ｇ、樹脂２００ｇを添加し、加温ニーダーで混練し、ジルコニア添加アルミナコンパウンドを作製した。 Examples 1-3
High purity alumina powder (manufactured by Daimei Chemical Co., Ltd.) having a purity of 99.99% or more and a specific surface area of 14 m 2 / g, 1 μm or less, and a zirconia powder (Tosoh 3Y (3 mol% Y 2 O 3 -97 mol) % ZrO 2 )), Na 2 O, SiO 2 and other wax-based thermoplastic resin containing impurities, 0.4 g of zirconia and 200 g of resin are added to 1000 g of alumina, kneaded with a heating kneader, and zirconia-added alumina compound Was made.

当該コンパウンドを射出成形機によりプレート形状に成形した。成形体を６００℃まで加熱し脱脂した後、大気中にて１３００℃、２時間焼成し一次焼結体を得た。一次焼結体をＨＩＰ装置にて、１５０ＭＰａのアルゴンガス雰囲気中で処理温度を１５５０、１６００、１６５０℃の各温度で１時間処理した。   The compound was molded into a plate shape by an injection molding machine. The molded body was heated to 600 ° C. and degreased, and then fired in the atmosphere at 1300 ° C. for 2 hours to obtain a primary sintered body. The primary sintered body was treated with a HIP apparatus at a treatment temperature of 1550, 1600, and 1650 ° C. for 1 hour in an argon gas atmosphere of 150 MPa.

１６００℃でＨＩＰ処理した焼結体のケミカルエッチング面光学顕微鏡写真の一例を図１に示す。異なる箇所から同様の写真を７枚撮影し、それを用いた画像解析結果を表１に示す。焼結体組織は２０μｍ以上の大きい異方性板状アルミナ粒子と１０μｍ以下の小さい等軸形状粒子との２種類の焼結粒子組織からなるものであった。   An example of a chemical etching surface optical micrograph of a sintered body HIP-treated at 1600 ° C. is shown in FIG. Seven similar photographs were taken from different locations, and Table 1 shows the image analysis results using them. The sintered body structure consisted of two kinds of sintered particle structures of large anisotropic plate-like alumina particles of 20 μm or more and small equiaxed particles of 10 μm or less.

長軸長さ１０μｍ以上、アスペクト比１．５以上の異方性粒子割合、破壊靱性、曲げ強度、全光線透過率、密度の測定を行った。結果を表２に示す。焼結体は異方性粒子を含有し、高い破壊靱性と優れた透光性を有するものであった。また、１６００℃ＨＩＰ処理試料の化学分析を行った。結果を表３に示す。Ｚｒ、Ｎａ、Ｓｉの各元素が含有されていることを確認した。   The ratio of anisotropic particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more, fracture toughness, bending strength, total light transmittance, and density were measured. The results are shown in Table 2. The sintered body contained anisotropic particles and had high fracture toughness and excellent translucency. Moreover, the chemical analysis of the 1600 degreeC HIP processing sample was performed. The results are shown in Table 3. It was confirmed that each element of Zr, Na, and Si was contained.

Figure 2010105884
Figure 2010105884

Figure 2010105884
Figure 2010105884

Figure 2010105884
Figure 2010105884

実施例４〜６
実施例１〜３で用いたものと同様の高純度アルミナ粉末（大明化学工業製）にＺｒＯ２粉末を０．０５ｗｔ％、炭酸ナトリウムをＮａ２Ｏ換算で０．０３ｗｔ％添加し、高純度アルミナボールを用い水溶媒中で混合し、ＺｒＯ２・Ｎａ２Ｏ含有アルミナ粉末を調製した。同様の方法で、Ｙ２Ｏ３・Ｎａ２Ｏ含有アルミナ粉末、Ｌａ２Ｏ３・Ｎａ２Ｏ含有アルミナ粉末を得た。 Examples 4-6
0.05% by weight of ZrO 2 powder and 0.03% by weight of sodium carbonate in terms of Na 2 O were added to the same high-purity alumina powder (manufactured by Daimei Chemical Co., Ltd.) as used in Examples 1 to 3. ZrO 2 · Na 2 O-containing alumina powder was prepared by mixing in a water solvent using a ball. In the same manner, Y 2 O 3 .Na 2 O-containing alumina powder and La 2 O 3 .Na 2 O-containing alumina powder were obtained.

これらの粉末を用い、金型一軸プレス装置で圧力５０ＭＰａを加えて４０ｍｍ×５０ｍｍ、厚さ５ｍｍの板状成形体とし、さらにゴム型に入れ冷間静水圧プレス装置で圧力２００ＭＰａを加えて成形した。成形体を大気中１４００℃で２時間焼結し一次焼結体とし、さらにそれをＨＩＰ装置によりアルゴンガス中、温度１５５０℃、圧力１５０ＭＰａで１時間処理した。   Using these powders, a plate-shaped molded body of 40 mm × 50 mm and a thickness of 5 mm was formed by applying a pressure of 50 MPa with a uniaxial pressing device of a mold, and further molded into a rubber mold by applying a pressure of 200 MPa with a cold isostatic pressing device. . The formed body was sintered in the atmosphere at 1400 ° C. for 2 hours to obtain a primary sintered body, which was further treated with an HIP apparatus in argon gas at a temperature of 1550 ° C. and a pressure of 150 MPa for 1 hour.

得られた焼結体試料の化学分析を行った。結果を表４に示す。焼結体のケミカルエッチング面の観察から、これらの焼結体は異方性粒子を含有していた。実施例１〜３と同様の画像解析を行い、長軸長さ１０μｍ以上、アスペクト比１．５以上の異方性粒子割合を求め、破壊靱性、曲げ強度、全光線透過率、密度の測定を行った。結果を表５に示す。いずれの焼結体も異方性粒子を含み、高い破壊靱性と優れた透光性を有するものであった。   The obtained sintered body sample was subjected to chemical analysis. The results are shown in Table 4. From the observation of the chemically etched surface of the sintered bodies, these sintered bodies contained anisotropic particles. The same image analysis as in Examples 1 to 3 is performed, the ratio of anisotropic particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more is determined, and fracture toughness, bending strength, total light transmittance, and density are measured. went. The results are shown in Table 5. All of the sintered bodies contained anisotropic particles and had high fracture toughness and excellent translucency.

Figure 2010105884
Figure 2010105884

Figure 2010105884
Figure 2010105884

実施例７〜１０
実施例１及び３と同様の処理を施した焼結体から両面鏡面研磨した厚さ１ｍｍの試料を作製し、１３００℃、１４００℃の各温度で大気中１時間加熱処理し、処理前後の全光線透過率を測定した。全光線透過率の変化を表６に示す。 Examples 7-10
A sample having a thickness of 1 mm, which is mirror-polished on both sides from a sintered body that has been subjected to the same treatment as in Examples 1 and 3, is heated at 1300 ° C. and 1400 ° C. for 1 hour in the air, The light transmittance was measured. Table 6 shows changes in the total light transmittance.

Figure 2010105884
Figure 2010105884

実施例１１
実施例１〜３と同様のコンパウンドを用い、射出成形により歯列矯正ブラケットを作製した。成形体を６００℃まで加熱し脱脂した後、大気中にて１３００℃、２時間焼成し一次焼結体を得た。その一次焼結体を蓋つきアルミナ容器に入れ、ＨＩＰ装置に設置し、アルゴンガス雰囲気中１５０ＭＰａの圧力下で１６００℃、１時間処理した。得られたブラケットは実施例２のサンプルと同程度の透光性を示していた。ブラケットのトルク強度を測定した結果、０．６９ｋｇ・ｃｍの値が得られ、市販アルミナブラケットに比較して２０％以上高強度であった。 Example 11
An orthodontic bracket was produced by injection molding using the same compounds as in Examples 1 to 3. The molded body was heated to 600 ° C. and degreased, and then fired in the atmosphere at 1300 ° C. for 2 hours to obtain a primary sintered body. The primary sintered body was placed in an alumina container with a lid, placed in a HIP apparatus, and treated at 1600 ° C. for 1 hour under a pressure of 150 MPa in an argon gas atmosphere. The obtained bracket exhibited the same degree of translucency as the sample of Example 2. As a result of measuring the torque strength of the bracket, a value of 0.69 kg · cm was obtained, which was 20% or more higher than the commercially available alumina bracket.

なお、トルク強度は、ブラケットを試料台に接着した後、そのスロットに０．０１８×０．０２５インチＳＵＳ製ワイヤーを挿入し、トルク測定装置においてブラケットを、ワイヤーを固定した状態で回転させ、それが破壊するときの応力から算出した。測定値５点の平均値とした。   The torque strength is determined by bonding the bracket to the sample table, inserting a 0.018 x 0.025 inch SUS wire into the slot, and rotating the bracket with the wire fixed in the torque measuring device. Was calculated from the stress at the time of failure. The average value of five measured values was used.

比較例１〜４
実施例で用いたものと同じ高純度アルミナ粉末（大明化学工業製 純度９９．９９％以上）にＺｒＯ２のみを０．０５ｗｔ％添加した粉末、Ｙ２Ｏ３のみを０．０５ｗｔ％添加した粉末、Ｌａ２Ｏ３のみを０．０５ｗｔ％添加した粉末、及び無添加の粉末を用い、ＨＩＰ温度を１４００℃とした以外は、実施例４〜６と全く同様の方法で透光性アルミナ焼結体を得た。焼結体の化学分析結果を表７に示す。 Comparative Examples 1-4
Powder obtained by adding 0.05 wt% of ZrO 2 alone to the same high purity alumina powder (purity 99.99% or more manufactured by Daimei Chemical Industries) as used in Examples, and powder containing 0.05 wt% of Y 2 O 3 alone Translucent alumina sintered in the same manner as in Examples 4 to 6 except that 0.05 wt% of La 2 O 3 added powder and non-added powder were used and the HIP temperature was 1400 ° C. Got the body. Table 7 shows the chemical analysis results of the sintered body.

いずれも図２に示すような等軸形状粒子からなり、異方形状粒子は認められなかった。平均粒径、平均アスペクト比、破壊靱性、曲げ強度、全光線透過率、密度の測定を行った。結果を表８に示す。ＺｒＯ２等の添加による粒成長抑制効果により、長軸長さ１０μｍ以上、アスペクト比１．５以上の異方性粒子が含まれず、曲げ強度は高いが破壊靱性は低いものであった。ＺｒＯ２等を添加したものは密度が十分に高いにもかかわらず透光性に劣るものであった。 All consisted of equiaxed particles as shown in FIG. 2, and no anisotropically shaped particles were observed. The average particle size, average aspect ratio, fracture toughness, bending strength, total light transmittance, and density were measured. The results are shown in Table 8. Due to the effect of suppressing grain growth by adding ZrO 2 or the like, anisotropic particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more were not included, and the bending strength was high but the fracture toughness was low. A material obtained by adding ZrO 2, etc. density was inferior in sufficiently high despite translucency.

Figure 2010105884
Figure 2010105884

Figure 2010105884
Figure 2010105884

比較例５〜６
比較例４で用いた無添加の焼結体を実施例７〜１０と同様の方法で加熱処理し、処理前後の全光線透過率を測定し、加熱による透光性の低下を評価した。実施例７〜１０に比較して、透過率の低下が顕著であった。結果を表９に示す。 Comparative Examples 5-6
The additive-free sintered body used in Comparative Example 4 was heat-treated in the same manner as in Examples 7 to 10, the total light transmittance before and after the treatment was measured, and the decrease in translucency due to heating was evaluated. Compared with Examples 7-10, the fall of the transmittance | permeability was remarkable. The results are shown in Table 9.

Figure 2010105884
Figure 2010105884

本発明の焼結体組織（実施例２）を示す光学顕微鏡写真Optical micrograph showing the sintered body structure of the present invention (Example 2) 等軸形状粒子からなる焼結体組織（比較例４）を示す光学顕微鏡写真Optical micrograph showing sintered body structure (Comparative Example 4) composed of equiaxed particles

Claims (10)

ランタノイド、ジルコニア及びイットリアの群から選ばれる少なくとも１種以上の酸化物を総量で１００〜１０００ｐｐｍ、１Ａ族アルカリ金属酸化物、２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５及びＧｅＯ２の群から選ばれる少なくとも１種以上を総量で２０〜１０００ｐｐｍ含有し、なおかつ破壊靭性が４．５ＭＰａ・ｍ０．５以上、波長６００ｎｍの可視光に対する全光線透過率（試料厚さ１ｍｍ）が６０％以上であるアルミナ焼結体。 Lanthanoid, 100 to 1000 ppm in a total amount of at least one oxide selected from the group consisting of zirconia and yttria, 1A Group alkali metal oxides, 2A group alkaline earth metal oxide, SiO 2, B 2 O 3 , P 2 Total light transmittance (visible thickness of sample light) for visible light containing at least one selected from the group of O 5 and GeO 2 in a total amount of 20 to 1000 ppm and having a fracture toughness of 4.5 MPa · m 0.5 or more and a wavelength of 600 nm 1 mm) is an alumina sintered body having 60% or more. ランタノイドの酸化物がＬａ２Ｏ３のＬｕ２Ｏ３いずれか1種以上である請求項１に記載のアルミナ焼結体。 The alumina sintered body according to claim 1, wherein the lanthanoid oxide is at least one of La 2 O 3 and Lu 2 O 3 . 焼結粒子に長軸長さが１０μｍ以上、アスペクト比１．５以上の異方性粒子を含むことを特徴とする請求項１乃至２に記載のアルミナ焼結体。 3. The alumina sintered body according to claim 1, wherein the sintered particles include anisotropic particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more. 長軸長さが１０μｍ以上、アスペクト比１．５以上の異方性粒子の含有率が２０ｖｏｌ％以上である請求項１乃至３に記載のアルミナ焼結体。 4. The alumina sintered body according to claim 1, wherein the content of anisotropic particles having a major axis length of 10 μm or more and an aspect ratio of 1.5 or more is 20 vol% or more. ランタノイド、ジルコニア及びイットリアの群から選ばれる少なくとも１種以上の酸化物を総量で１００〜１０００ｐｐｍ、１Ａ族アルカリ金属酸化物、２Ａ族アルカリ土類金属酸化物、ＳｉＯ２、Ｂ２Ｏ３、Ｐ２Ｏ５及びＧｅＯ２の群から選ばれる少なくとも１種以上を総量で２０〜１０００ｐｐｍ含有するアルミナ粉末を成形後、常圧焼結した後、さらに熱間静水圧プレス（ＨＩＰ）処理するアルミナ焼結体の製造方法。 Lanthanoid, 100 to 1000 ppm in a total amount of at least one oxide selected from the group consisting of zirconia and yttria, 1A Group alkali metal oxides, 2A group alkaline earth metal oxide, SiO 2, B 2 O 3 , P 2 An alumina sintered body that is subjected to hot isostatic pressing (HIP) after forming an alumina powder containing 20 to 1000 ppm in total of at least one selected from the group consisting of O 5 and GeO 2 and then sintering at atmospheric pressure Manufacturing method. 比表面積５〜２０ｍ２／ｇ、１μｍ以下の微粒子が９０ｖｏｌ％以上のアルミナ粉末を用いる請求項５に記載の製造方法。 The production method according to claim 5, wherein alumina powder having a specific surface area of 5 to 20 m 2 / g and fine particles of 1 μm or less of 90 vol% or more is used. 常圧焼結温度が１２５０〜１４５０℃である請求項５乃至６に記載の製造方法。 The manufacturing method according to claim 5, wherein the atmospheric pressure sintering temperature is 1250 to 1450 ° C. 熱間静水圧プレス（ＨＩＰ）処理が温度１５５０〜１７００℃、圧力５０ＭＰａ以上で行う請求項５乃至７に記載の製造方法。 The manufacturing method of Claim 5 thru | or 7 which performs a hot isostatic press (HIP) process at the temperature of 1550-1700 degreeC, and the pressure of 50 Mpa or more. 請求項１乃至４に記載のアルミナ焼結体を用いた歯科材料。 A dental material using the alumina sintered body according to claim 1. 歯列矯正ブラケット又は歯科修復用ミルブランクのいずれかである請求項９の歯科材料。 The dental material of claim 9 which is either an orthodontic bracket or a dental restoration mill blank.
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Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130002952A (en) * 2011-06-29 2013-01-08 가부시키가이샤 니혼 세라떽꾸 Alumina-based ceramics and method for the preparation thereof
WO2015037788A1 (en) * 2013-09-10 2015-03-19 주식회사 하스 Method for fabricating ready-made ceramic restoration, and ready-made ceramic restoration fabricated thereby for dental and veterinary services
CN108546097A (en) * 2018-07-03 2018-09-18 洛阳欣珑陶瓷有限公司 Ice porcelain and its preparation process
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

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5458553B2 (en) * 2008-11-18 2014-04-02 東ソー株式会社 Highly tough and translucent colored alumina sintered body, method for producing the same, and use
JP5458552B2 (en) * 2008-11-18 2014-04-02 東ソー株式会社 Highly tough and translucent colored alumina sintered body, method for producing the same, and use

Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56160374A (en) * 1980-05-15 1981-12-10 Ngk Insulators Ltd Polycrystal transparent alumina sintered body, manufacture thereof and high pressure vapor discharge lamp therewith
JPS63174646A (en) * 1987-01-12 1988-07-19 住友化学工業株式会社 Orthodontic material
JPH04198060A (en) * 1990-11-29 1992-07-17 Sumitomo Metal Mining Co Ltd Light-transmitting ceramics and production thereof
WO1995006622A1 (en) * 1993-09-02 1995-03-09 Toto Ltd. Light-permeable ceramic material and method of manufacturing the same
JPH0817396A (en) * 1993-12-10 1996-01-19 Ngk Insulators Ltd High-pressure discharge lamp with ceramic discharge tube, sintered body suitable for said discharge tube and manufacture of said sintered body
JPH08151254A (en) * 1994-11-28 1996-06-11 Kyocera Corp Alumina-based sintered compact
JPH08208317A (en) * 1995-01-31 1996-08-13 Kyocera Corp Alumina sintered body and production thereof
JPH0987008A (en) * 1995-09-28 1997-03-31 Kyocera Corp Aluminous sintered compact and its production
JPH111365A (en) * 1997-06-12 1999-01-06 Agency Of Ind Science & Technol High tenacity aluminum oxide sintered material and production thereof
JP2004315313A (en) * 2003-04-17 2004-11-11 Kagawa Prefecture Method for manufacturing alumina arc tube and alumina arc tube manufactured by the manufacturing method
JP2006087915A (en) * 2004-08-27 2006-04-06 Tosoh Corp Orthodontic bracket and manufacturing method thereof
JP2008195581A (en) * 2007-02-14 2008-08-28 Tosoh Corp Translucent alumina sintered compact and its manufacturing method

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56160374A (en) * 1980-05-15 1981-12-10 Ngk Insulators Ltd Polycrystal transparent alumina sintered body, manufacture thereof and high pressure vapor discharge lamp therewith
JPS63174646A (en) * 1987-01-12 1988-07-19 住友化学工業株式会社 Orthodontic material
JPH04198060A (en) * 1990-11-29 1992-07-17 Sumitomo Metal Mining Co Ltd Light-transmitting ceramics and production thereof
WO1995006622A1 (en) * 1993-09-02 1995-03-09 Toto Ltd. Light-permeable ceramic material and method of manufacturing the same
JPH0817396A (en) * 1993-12-10 1996-01-19 Ngk Insulators Ltd High-pressure discharge lamp with ceramic discharge tube, sintered body suitable for said discharge tube and manufacture of said sintered body
JPH08151254A (en) * 1994-11-28 1996-06-11 Kyocera Corp Alumina-based sintered compact
JPH08208317A (en) * 1995-01-31 1996-08-13 Kyocera Corp Alumina sintered body and production thereof
JPH0987008A (en) * 1995-09-28 1997-03-31 Kyocera Corp Aluminous sintered compact and its production
JPH111365A (en) * 1997-06-12 1999-01-06 Agency Of Ind Science & Technol High tenacity aluminum oxide sintered material and production thereof
JP2004315313A (en) * 2003-04-17 2004-11-11 Kagawa Prefecture Method for manufacturing alumina arc tube and alumina arc tube manufactured by the manufacturing method
JP2006087915A (en) * 2004-08-27 2006-04-06 Tosoh Corp Orthodontic bracket and manufacturing method thereof
JP2008195581A (en) * 2007-02-14 2008-08-28 Tosoh Corp Translucent alumina sintered compact and its manufacturing method

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20130002952A (en) * 2011-06-29 2013-01-08 가부시키가이샤 니혼 세라떽꾸 Alumina-based ceramics and method for the preparation thereof
JP2013010668A (en) * 2011-06-29 2013-01-17 Taiheiyo Cement Corp Alumina ceramics, and method for producing the same
KR101907038B1 (en) * 2011-06-29 2018-10-11 니뽄 도쿠슈 도교 가부시키가이샤 Alumina-based ceramics and method for the preparation thereof
WO2015037788A1 (en) * 2013-09-10 2015-03-19 주식회사 하스 Method for fabricating ready-made ceramic restoration, and ready-made ceramic restoration fabricated thereby for dental and veterinary services
CN108546097A (en) * 2018-07-03 2018-09-18 洛阳欣珑陶瓷有限公司 Ice porcelain and its preparation process
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

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