JPH10324519A - Production of easily sinterable high purity alumina powder - Google Patents
Production of easily sinterable high purity alumina powderInfo
- Publication number
- JPH10324519A JPH10324519A JP9144588A JP14458897A JPH10324519A JP H10324519 A JPH10324519 A JP H10324519A JP 9144588 A JP9144588 A JP 9144588A JP 14458897 A JP14458897 A JP 14458897A JP H10324519 A JPH10324519 A JP H10324519A
- Authority
- JP
- Japan
- Prior art keywords
- alumina powder
- acid
- powder
- purity
- slurry
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000843 powder Substances 0.000 title claims abstract description 71
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 title claims abstract description 56
- 238000004519 manufacturing process Methods 0.000 title claims description 15
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 25
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims abstract description 22
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims abstract description 20
- 229910052742 iron Inorganic materials 0.000 claims abstract description 11
- 238000005406 washing Methods 0.000 claims abstract description 11
- 239000002245 particle Substances 0.000 claims abstract description 10
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 claims abstract description 7
- 229910017604 nitric acid Inorganic materials 0.000 claims abstract description 7
- 238000000034 method Methods 0.000 abstract description 11
- 239000002002 slurry Substances 0.000 abstract description 11
- 239000002253 acid Substances 0.000 abstract description 8
- 238000010298 pulverizing process Methods 0.000 abstract description 8
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 6
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 abstract description 2
- 239000011324 bead Substances 0.000 abstract description 2
- 238000010438 heat treatment Methods 0.000 abstract description 2
- 239000002904 solvent Substances 0.000 abstract description 2
- 230000000052 comparative effect Effects 0.000 description 12
- 239000011148 porous material Substances 0.000 description 12
- 238000005245 sintering Methods 0.000 description 8
- 238000011109 contamination Methods 0.000 description 5
- 239000012535 impurity Substances 0.000 description 5
- PPQREHKVAOVYBT-UHFFFAOYSA-H dialuminum;tricarbonate Chemical group [Al+3].[Al+3].[O-]C([O-])=O.[O-]C([O-])=O.[O-]C([O-])=O PPQREHKVAOVYBT-UHFFFAOYSA-H 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 230000005484 gravity Effects 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- -1 aluminum carbonate hydroxide ammonium Chemical compound 0.000 description 3
- 238000000227 grinding Methods 0.000 description 3
- QGZKDVFQNNGYKY-UHFFFAOYSA-O Ammonium Chemical compound [NH4+] QGZKDVFQNNGYKY-UHFFFAOYSA-O 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 229940118662 aluminum carbonate Drugs 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 2
- 238000004140 cleaning Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000004065 semiconductor Substances 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 238000007088 Archimedes method Methods 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 230000010354 integration Effects 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000000967 suction filtration Methods 0.000 description 1
- 238000005979 thermal decomposition reaction Methods 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
Description
【0001】[0001]
【発明の属する技術分野】本発明は、高純度のアルミナ
粉末の製造方法に関し、特に易焼結性を有する高純度の
アルミナ粉末の製造方法に関する。The present invention relates to a method for producing high-purity alumina powder, and more particularly to a method for producing high-purity alumina powder having easy sinterability.
【0002】[0002]
【従来の技術】半導体の高集積化と小型化により、半導
体の製造装置に用いる部品や部材には、耐薬品性、耐プ
ラズマ性に優れるのみならず、ポアの極めて少ないセラ
ミックスが要望されており、そのセラミックスには安価
で使い易いアルミナセラミックスに特にその要望が高ま
っている。2. Description of the Related Art Due to the high integration and miniaturization of semiconductors, ceramics having not only excellent chemical resistance and plasma resistance but also extremely few pores are required for parts and members used in semiconductor manufacturing equipment. In particular, the demand for alumina ceramics which are inexpensive and easy to use is increasing.
【0003】この要望に対応するため、従来は、高純度
のアルミナ粉末を常圧焼結した後、さらにHIP処理
(熱間静水圧処理)することにより、常圧焼結で残留し
た焼結体中のポアを押しつぶすことでその数を低減して
いた。しかし、この方法は、常圧焼結に1500℃以上
の高温を必要とするので、粒成長を生じ、HIP処理し
ても十分なポア低減の効果が発揮されず、焼結体に多く
のポアが残存するという問題があった。[0003] In order to respond to this demand, conventionally, high-purity alumina powder has been subjected to normal pressure sintering and then HIP treatment (hot isostatic pressure treatment) to obtain a sintered body remaining in normal pressure sintering. The number was reduced by crushing the inside pore. However, since this method requires a high temperature of 1500 ° C. or more for normal pressure sintering, grain growth occurs, and a sufficient pore reduction effect is not exhibited even by HIP treatment, and many pores are formed in the sintered body. There is a problem that remains.
【0004】また、常圧焼結に1500℃以上の高温を
必要とするためHIP処理温度も1400℃以上の温度
を必要とするので、HIP処理装置の熱源(ヒータ)や
断熱材をカーボン材で形成する必要があった。そのた
め、HIP処理装置の構造や耐久性に問題が生じ、14
00℃以上でHIP処理を行える大型のHIP装置がな
く、作製する製品の大きさが制限されるという問題もあ
った。[0004] In addition, since a high temperature of 1500 ° C or more is required for normal pressure sintering, a HIP processing temperature of 1400 ° C or more is required. Therefore, a heat source (heater) and a heat insulating material of the HIP processing apparatus are made of carbon material. Needed to be formed. As a result, problems arise in the structure and durability of the HIP processing apparatus,
There is no large-scale HIP device capable of performing the HIP process at a temperature of 00 ° C. or higher, and there is a problem that the size of a manufactured product is limited.
【0005】これを解決するため、1400℃以下の温
度で焼結可能とする高純度のアルミナ粉末を得る製造方
法として、アルミニウム・カーボネイト・ハイドロオキ
サイド・アンモニウム(NH4AlCO3(OH))を熱
分解した後、1200〜1400℃の温度で焙焼して製
造する方法が「窯協,84,255〜258(199
6)」で提案されている。この他、アルミニウムアルコ
キシドを加水分解し、得られた水和物を焼成して製造す
る方法も「化学総説,48,173〜178(198
5)」で提案されている。これらの方法は、製造された
アルミナ粉末が、高純度である上に極めて微粉であるた
め、1400℃以下の低温でも常圧焼結できる粉末を得
ることのできる製造方法となっている。In order to solve this problem, as a method for producing high-purity alumina powder which can be sintered at a temperature of 1400 ° C. or less, aluminum carbonate hydroxide ammonium (NH 4 AlCO 3 (OH)) is used. After the decomposition, a method of manufacturing by roasting at a temperature of 1200 to 1400 ° C. is described in “Kirakukyo, 84, 255 to 258 (199).
6) ". In addition, a method of hydrolyzing an aluminum alkoxide and calcining the obtained hydrate to produce the hydrate is also described in “Chemical Review, 48, 173-178 (198).
5) ". These methods are high-purity and extremely fine powders of the produced alumina powder, so that the powder can be sintered under normal pressure even at a low temperature of 1400 ° C. or less.
【0006】[0006]
【発明が解決しようとする課題】しかしながら、前記し
た前者の方法では、製造工程が複雑であるため、アルミ
ナ粉末を多量に製造することができないという問題があ
った。また、後者の方法でも、使用するアルミニウムア
ルコキシドが高価であるため、製造されたアルミナ粉末
が非常に高価となり、アルミナ粉末を安価に製造するこ
とができないという問題があった。However, the former method has a problem that a large amount of alumina powder cannot be produced due to the complicated production steps. Also, in the latter method, since the aluminum alkoxide to be used is expensive, the produced alumina powder becomes very expensive, and there is a problem that the alumina powder cannot be produced at low cost.
【0007】本発明は、上述した低温で焼結可能な易焼
結性高純度アルミナ粉末の製造方法が有する課題に鑑み
なされたものであって、その目的は、安価で多量に製造
することのできる易焼結性高純度アルミナ粉末の製造方
法を提供することにある。SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the method for producing an easily sinterable high-purity alumina powder which can be sintered at a low temperature. An object of the present invention is to provide a method for producing a high-purity alumina powder that can be easily sintered.
【0008】[0008]
【課題を解決するための手段】本発明者等は、上記目的
を達成するため鋭意研究した結果、市販の高純度アルミ
ナ粉末を比重の大きい鉄製の小径媒体で粉砕した後、媒
体から混入したFeを酸洗浄により除去すれば、易焼結
性を有する高純度のアルミナ粉末が安価で多量に得られ
るとの知見を得て本発明を完成するに至った。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and as a result, obtained by pulverizing a commercially available high-purity alumina powder with a small diameter medium made of iron having a large specific gravity, and then mixing Fe powder mixed from the medium. It has been found that removal of acid by acid washing can provide a large amount of high-purity alumina powder having easy sintering properties at low cost and completed the present invention.
【0009】即ち本発明は、純度が99.99%以上の
アルミナ粉末を直径が2mm以下の鉄媒体で平均粒径が
0.2ミクロン以下で、比表面積が15×103m2/k
g以上に粉砕した後、そのアルミナ粉末を塩酸または硝
酸で洗浄し、さらに濃度が10N以上の硫酸で洗浄する
ことを特徴とする易焼結性高純度アルミナ粉末の製造方
法とすることを要旨とする。以下、さらに詳細に説明す
る。That is, according to the present invention, an alumina powder having a purity of 99.99% or more is prepared by using an iron medium having a diameter of 2 mm or less with an average particle size of 0.2 μm or less and a specific surface area of 15 × 10 3 m 2 / k.
g, and then the alumina powder is washed with hydrochloric acid or nitric acid, and further washed with sulfuric acid having a concentration of 10 N or more. I do. The details will be described below.
【0010】この製造方法は、安価に購入できる市販の
高純度アルミナ粉末を微粉砕することで、易焼結性を有
する高純度のアルミナ微粉末を安価でしかも多量に得る
製造方法であって、その出発原料としては、純度が9
9.99%以上の高純度のアルミナ粉末とした。純度が
99.99%より低くなると、1400℃より低い温度
で焼結できても粒成長を生じ、ポアの少ない焼結体が得
られ難くなるので好ましくない。[0010] This production method is a production method in which a commercially available high-purity alumina powder which can be purchased at a low cost is finely pulverized to obtain a high-purity alumina fine powder having an easy sintering property at a low cost and in a large amount. The starting material has a purity of 9
A high-purity alumina powder of 9.99% or more was obtained. If the purity is lower than 99.99%, it is not preferable because sintering can be performed at a temperature lower than 1400 ° C., but grain growth occurs, and it becomes difficult to obtain a sintered body having few pores.
【0011】その高純度のアルミナ粉末を粉砕で微細化
する。粉砕操作で原料粉末を微細化することで、粉末の
活性が向上し、易焼結性の粉末が得られることはよく知
られているが、その粉砕で媒体の摩耗は避け難く、この
摩耗によりコンタミが発生し、このコンタミにより、易
焼結性は向上するものの、逆に粒成長が生じ、ポアを低
減することが難しくなる。The high-purity alumina powder is pulverized into fine particles. It is well known that the activity of the powder is improved by pulverizing the raw material powder by a pulverizing operation, so that an easily sinterable powder can be obtained.However, abrasion of the medium cannot be avoided by the pulverization. Contamination occurs, and although the sinterability is improved due to the contamination, grain growth occurs on the contrary, and it becomes difficult to reduce pores.
【0012】そのため、用いる媒体としては、コンタミ
は発生するが、そのコンタミの除去が可能であって、し
かも微細化をより進めることのできるものとして、比重
の大きい鉄媒体とした。比重の大きいZrO2媒体も考
えられるが、それから混入するコンタミの除去が難し
く、高純度化することができない。また、コンタミの混
入には問題のない高純度のアルミナを媒体として用いる
ことも考えられるが、媒体の比重が小さいため、粉砕効
率が悪く、目的とする微細化には長時間の粉砕を要し、
現実的ではない。For this reason, as a medium to be used, contamination is generated, but an iron medium having a large specific gravity is used as a medium that can remove the contamination and can further advance the miniaturization. Although a ZrO 2 medium having a large specific gravity is conceivable, it is difficult to remove contaminants from the ZrO 2 medium, and high purity cannot be achieved. It is also conceivable to use high-purity alumina which has no problem for contamination as a medium.However, since the specific gravity of the medium is small, the grinding efficiency is poor, and long-term grinding is required to achieve the desired fineness. ,
Not realistic.
【0013】用いる鉄媒体の大きさとしては、直径2m
m以下とした。2mmより大きいと微細化が難しくなる
ので好ましくない。その粉砕する細かさとしては、平均
粒径で0.2μm以下とし、比表面積で15×103m2
/kg以上とした。平均粒径が0.2μmより粗いと易
焼結性が望めず、比表面積が15×103m2/kgより
小さいとこれも同様易焼結性が望めない。The size of the iron medium used is 2 m in diameter.
m or less. If it is larger than 2 mm, miniaturization becomes difficult, which is not preferable. The fineness of the pulverization is 0.2 μm or less in average particle size and 15 × 10 3 m 2 in specific surface area.
/ Kg or more. If the average particle size is coarser than 0.2 μm, sinterability cannot be expected, and if the specific surface area is less than 15 × 10 3 m 2 / kg, sinterability cannot be expected.
【0014】粉砕で摩耗して混入するFeの除去として
は、先ずアルミナ粉末を塩酸または硝酸で洗浄した後、
さらに硫酸で洗浄することとした。粉砕により数%のF
eが混入するので、その大部分を先ず塩酸または硝酸で
洗浄する。この洗浄を行った粉末中にはまだ50〜50
0ppmのFeが含まれているため、さらに洗浄力の強
い硫酸で洗浄する。その硫酸の濃度としては、10N以
上が必要であり、10Nより低いと洗浄効果が弱く、残
存するFe等(Fe、Fe2O3等)を十分に除去できな
い。脱鉄した粉末を最後に酸を洗い流して乾燥すること
により、易焼結性の微細で高純度のアルミナ粉末が得ら
れる。In order to remove Fe mixed in by abrasion in pulverization, alumina powder is first washed with hydrochloric acid or nitric acid,
Further, it was decided to wash with sulfuric acid. Several% of F by grinding
Most of them are first washed with hydrochloric acid or nitric acid because e is mixed. Some 50-50 still exist in the washed powder.
Since it contains 0 ppm of Fe, it is further washed with sulfuric acid having a strong detergency. The sulfuric acid concentration needs to be 10 N or more. If the concentration is lower than 10 N, the cleaning effect is weak, and the remaining Fe and the like (Fe, Fe 2 O 3, etc.) cannot be sufficiently removed. The acid is finally washed away from the de-ironed powder, followed by drying, so that a fine and high-purity alumina powder that is easily sintered can be obtained.
【0015】[0015]
【発明の実施の形態】本発明の製造方法をさらに詳細に
述べると、先ず純度が99.99%以上の市販されてい
る高純度アルミナ粉末を用意する。その粉末に水あるい
はアルコール等の溶媒を加え、それを粉砕機、例えばア
トリッションミル、ボールミル、アトライター、ビーズ
ミル等の粉砕機に入れ、直径が2mm以下の鉄媒体で所
望の細かさに粉砕する。粉砕時間は、それぞれの粉砕機
に合わせて決めればよい。また、アルミナのスラリー中
の濃度は、所望する平均粒径の大きさと粉砕機の種類な
どにより異なるが、平均粒径が0.2〜0.1μmを狙
いとする場合には、20〜40wt%程度でよい。BEST MODE FOR CARRYING OUT THE INVENTION The production method of the present invention will be described in more detail. First, a commercially available high-purity alumina powder having a purity of 99.99% or more is prepared. A solvent such as water or alcohol is added to the powder, which is then put into a pulverizer such as an attrition mill, a ball mill, an attritor, a bead mill, and pulverized to a desired fineness with an iron medium having a diameter of 2 mm or less. I do. The crushing time may be determined according to each crusher. The concentration of alumina in the slurry varies depending on the desired average particle size and the type of the pulverizer, but when the average particle size is aimed at 0.2 to 0.1 μm, the concentration is 20 to 40 wt%. Degree is fine.
【0016】次いで、粉砕したアルミナスラリーを塩酸
または硝酸で洗浄する。この洗浄は、次式に示す理論量
の10〜50倍の酸溶液で洗浄、濾過を数回繰り返す。
なお、塩酸を使用する場合、洗浄効果をより発揮させる
ためには、希塩酸を使用するとよい。洗浄後、10N以
上の濃度の硫酸でさらに加熱洗浄した後、酸を除去する
ため、純水で洗浄、濾過する。そのスラリーをフィルタ
ープレス等で濾過し、乾燥するか、あるいはスプレード
ライヤ等で乾燥する。 2Fe+6HCl → 2FeCl3+3H2 2Fe+6HNO3 → 2Fe(NO3)3+3H2 Next, the pulverized alumina slurry is washed with hydrochloric acid or nitric acid. In this washing, washing and filtration are repeated several times with an acid solution of 10 to 50 times the theoretical amount shown in the following formula.
When hydrochloric acid is used, dilute hydrochloric acid is preferably used in order to further exhibit the cleaning effect. After the washing, the substrate is further heated and washed with sulfuric acid having a concentration of 10 N or more, and then washed with pure water and filtered to remove the acid. The slurry is filtered by a filter press or the like and dried, or dried by a spray dryer or the like. 2Fe + 6HCl → 2FeCl 3 + 3H 2 2Fe + 6HNO 3 → 2Fe (NO 3 ) 3 + 3H 2
【0017】以上の方法でアルミナ粉末を製造すれば、
微細で高純度の易焼結性に優れたアルミナ粉末を得るこ
とができる。If alumina powder is produced by the above method,
Fine, high-purity alumina powder excellent in sinterability can be obtained.
【0018】[0018]
【実施例】以下、本発明の実施例を比較例と共に具体的
に挙げ、本発明をより詳細に説明する。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples of the present invention and Comparative Examples.
【0019】(実施例1〜2) (1)アルミナ粉末の粉砕 純度が99.99%、平均粒径が0.5μmのアルミナ
粉末(昭和電工社製、KP−20)に、イオン交換水を
加えて固形分が25%のスラリーとした。このスラリー
を表1に示す媒体を用い、アトリッションミルで20分
間粉砕した。(Examples 1 and 2) (1) Pulverization of alumina powder Ion-exchanged water was added to alumina powder (KP-20, manufactured by Showa Denko KK) having a purity of 99.99% and an average particle size of 0.5 μm. In addition, a slurry having a solid content of 25% was obtained. This slurry was pulverized by an attrition mill for 20 minutes using the media shown in Table 1.
【0020】(2)アルミナ粉末の洗浄 得られたスラリー中には、化学分析したところ、5wt
%のFeを含んでいたので、2Nの塩酸または硝酸で3
回洗浄と吸引濾過を行った。そのスラリーにさらに10
Nの硫酸をアルミナ粉末100重量部に対し2重量部加
え、60℃で加熱洗浄し、濾過した。そのアルミナ粉末
に対し3重量部の純水を加え2回洗浄、濾過を繰り返し
た後、乾燥してアルミナ粉末を得た。(2) Washing of alumina powder The obtained slurry was analyzed by chemical analysis to find that 5 wt.
% Fe, so 3N with 2N hydrochloric acid or nitric acid
Washing and suction filtration were performed twice. Add 10 more to the slurry
N sulfuric acid was added in an amount of 2 parts by weight based on 100 parts by weight of the alumina powder, washed with heating at 60 ° C., and filtered. 3 parts by weight of pure water was added to the alumina powder, and washing and filtration were repeated twice, and then dried to obtain an alumina powder.
【0021】(3)評価 得られた粉末の平均粒径を沈降法で測定し、比表面積を
窒素吸着法で測定した。また、得られた粉末中の不純物
を化学分析で分析した。さらに、得られた粉末を用いて
以下のように作製した常圧焼結体とHIP処理した焼結
体の密度をアルキメデス法で求めると共に、HIP処理
した焼結体を研削し、鏡面加工した表面を顕微鏡観察し
て5μm以上のポアの数を調べた。それらの結果を表1
に示す。なお、焼結体の作製は、アルミナ粉末を金型成
形した後、1400Kg/cm2の圧力でφ50×t5
0mmの成形体をCIP成形し、その成形体を大気中で
1350℃の温度で2hr常圧焼結した後、1400℃
の温度で1800Kg/cm2の圧力でHIP処理し
た。(3) Evaluation The average particle size of the obtained powder was measured by a sedimentation method, and the specific surface area was measured by a nitrogen adsorption method. In addition, impurities in the obtained powder were analyzed by chemical analysis. Further, the densities of the atmospheric pressure sintered body and the HIP-treated sintered body prepared as described below using the obtained powder are determined by the Archimedes method, and the HIP-treated sintered body is ground and mirror-finished. Was observed under a microscope to determine the number of pores of 5 μm or more. Table 1 shows the results.
Shown in The sintered body was formed by molding a die of alumina powder and then pressing the powder at a pressure of 1400 Kg / cm 2 at φ50 × t5.
A 0 mm compact was subjected to CIP molding, and the compact was sintered at 1350 ° C. in the atmosphere under normal pressure for 2 hours, and then 1400 ° C.
HIP treatment at a temperature of 1800 Kg / cm 2 .
【0022】(比較例1〜5)比較のために、比較例1
では直径が5mmのFe媒体を用いて60分間粉砕し、
比較例2ではFe媒体ではなくAl2O3媒体を用いて6
0分間粉砕し、比較例3ではZrO2媒体を用いた他
は、実施例1と同様にアルミナ粉末を粉砕し、洗浄し、
評価した。また、比較例4では、5Nの硫酸を用いた他
は実施例1と同様にアルミナ粉末を粉砕し、洗浄し、評
価した。さらに、比較例5では、参考のためアルミニウ
ム・カーボネイト・ハイドロオキサイド・アンモニウム
の熱分解で得られたアルミナ粉末を用いて実施例1と同
様に作製した焼結体を評価した。それらの結果を表1に
示す。(Comparative Examples 1 to 5) For comparison, Comparative Example 1
Then, pulverize for 60 minutes using a 5 mm diameter Fe medium,
In Comparative Example 2, the Al 2 O 3 medium was used instead of the Fe medium.
The alumina powder was ground and washed in the same manner as in Example 1 except that ZrO 2 medium was used in Comparative Example 3 except that the alumina powder was ground.
evaluated. In Comparative Example 4, the alumina powder was pulverized, washed and evaluated in the same manner as in Example 1 except that 5N sulfuric acid was used. Further, in Comparative Example 5, for reference, a sintered body produced in the same manner as in Example 1 using an alumina powder obtained by thermal decomposition of aluminum carbonate, hydroxide and ammonium was evaluated. Table 1 shows the results.
【0023】[0023]
【表1】 [Table 1]
【0024】表1から明らかなように、実施例1、2に
おいては、アルミナ粉末の細かさが本発明の範囲内の細
かさとなっている。また、その粉末中の不純物は、10
0ppmより大幅に低くなっている。そしてこの粉末を
用いHIP処理して作製した焼結体のポア数は、4個以
下であった。このことは、得られたアルミナ粉末が、ア
ルミニウム・カーボネイト・ハイドロオキサイド・アン
モニウムの熱分解で得られたアルミナ粉末と同等の微細
で高純度の粉末であることを示し、その微細で高純度な
粉末であれば、低温度で焼結でき、しかも焼結体中のポ
アを極めて少なくすることができることを示している。As is clear from Table 1, in Examples 1 and 2, the fineness of the alumina powder is within the range of the present invention. The impurities in the powder are 10%.
It is significantly lower than 0 ppm. The number of pores of the sintered body produced by performing HIP treatment using this powder was 4 or less. This indicates that the obtained alumina powder is a fine and high-purity powder equivalent to the alumina powder obtained by pyrolysis of aluminum carbonate, hydroxide and ammonium, and the fine and high-purity powder This indicates that sintering can be performed at a low temperature and that pores in the sintered body can be extremely reduced.
【0025】これに対して比較例1では、媒体の大きさ
が大きすぎるため、アルミナ粉末の細かさが本発明の細
かさにならず、実施例1の温度では緻密化しなかった。
また、比較例2では、媒体がアルミナであるため、不純
物は少ないものの、これも比較例1と同じく粉末の細か
さが粗く、緻密化しなかった。さらに、比較例3では、
媒体がジルコニアであるため、細かさは満足するもの
の、不純物(ZrO2)が3%も残り、焼結体中のポア
を十分に低減できず、ポア数が実施例に比べはるかに多
かった。さらにまた、比較例4では、硫酸の濃度が低す
ぎるため、不純物が除去しきれずかなり残り、これも同
様ポア数が多かった。On the other hand, in Comparative Example 1, the size of the medium was too large, so that the fineness of the alumina powder did not become the fineness of the present invention, and the powder was not densified at the temperature of Example 1.
Further, in Comparative Example 2, although the medium was alumina, although the amount of impurities was small, the fineness of the powder was also coarse as in Comparative Example 1, and the powder was not densified. Further, in Comparative Example 3,
Since the medium was zirconia, fineness was satisfied, but as much as 3% of impurities (ZrO 2 ) remained, the pores in the sintered body could not be reduced sufficiently, and the number of pores was much larger than in the examples. Furthermore, in Comparative Example 4, since the concentration of sulfuric acid was too low, impurities could not be completely removed and remained considerably, and this also had a large number of pores.
【0026】[0026]
【発明の効果】本発明の方法でアルミナ粉末を製造する
ことにより、市販の高純度アルミナを粉砕することで、
微細で、高純度のアルミナ粉末が得られることができる
ようになった。これにより、従来の製造方法で得られる
易焼結性で高純度のアルミナ粉末と同等のアルミナ粉末
を安価で多量に得ることのできる製造方法を提供できる
ようになった。By producing alumina powder by the method of the present invention, commercially available high-purity alumina is crushed,
Fine, high-purity alumina powder can now be obtained. As a result, it has become possible to provide a production method capable of obtaining a large amount of alumina powder that is equivalent to the easily sinterable and high-purity alumina powder obtained by the conventional production method at low cost.
Claims (1)
を直径が2mm以下の鉄媒体で平均粒径が0.2ミクロ
ン以下で、比表面積が15×103m2/kg以上に粉砕
した後、そのアルミナ粉末を塩酸または硝酸で洗浄し、
さらに濃度が10N以上の硫酸で洗浄することを特徴と
する易焼結性高純度アルミナ粉末の製造方法。1. An alumina powder having a purity of 99.99% or more is pulverized with an iron medium having a diameter of 2 mm or less to an average particle diameter of 0.2 μm or less and a specific surface area of 15 × 10 3 m 2 / kg or more. After that, the alumina powder is washed with hydrochloric acid or nitric acid,
A method for producing an easily sinterable high-purity alumina powder, further comprising washing with sulfuric acid having a concentration of 10 N or more.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9144588A JPH10324519A (en) | 1997-05-20 | 1997-05-20 | Production of easily sinterable high purity alumina powder |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP9144588A JPH10324519A (en) | 1997-05-20 | 1997-05-20 | Production of easily sinterable high purity alumina powder |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH10324519A true JPH10324519A (en) | 1998-12-08 |
Family
ID=15365590
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP9144588A Pending JPH10324519A (en) | 1997-05-20 | 1997-05-20 | Production of easily sinterable high purity alumina powder |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH10324519A (en) |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001302233A (en) * | 2000-04-27 | 2001-10-31 | Sumitomo Chem Co Ltd | Method for producing alumina powder |
JP2005263529A (en) * | 2004-03-17 | 2005-09-29 | Sumitomo Chemical Co Ltd | Method for producing activated alumina having low alkali content |
JP2006111508A (en) * | 2004-10-18 | 2006-04-27 | Fujimi Inc | Method for manufacturing aluminum oxide powder |
WO2007037498A1 (en) * | 2005-09-30 | 2007-04-05 | Fujifilm Corporation | Method of manufacturing composite structure, impurity removal processing apparatus, film forming apparatus, composite structure and raw material powder |
US8124048B2 (en) | 2006-12-15 | 2012-02-28 | Nippon Light Metal Company, Ltd. | Process for producing high-purity α-alumina |
-
1997
- 1997-05-20 JP JP9144588A patent/JPH10324519A/en active Pending
Cited By (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2001302233A (en) * | 2000-04-27 | 2001-10-31 | Sumitomo Chem Co Ltd | Method for producing alumina powder |
JP4547770B2 (en) * | 2000-04-27 | 2010-09-22 | 住友化学株式会社 | Method for producing alumina powder |
JP2005263529A (en) * | 2004-03-17 | 2005-09-29 | Sumitomo Chemical Co Ltd | Method for producing activated alumina having low alkali content |
JP2006111508A (en) * | 2004-10-18 | 2006-04-27 | Fujimi Inc | Method for manufacturing aluminum oxide powder |
WO2007037498A1 (en) * | 2005-09-30 | 2007-04-05 | Fujifilm Corporation | Method of manufacturing composite structure, impurity removal processing apparatus, film forming apparatus, composite structure and raw material powder |
US8268408B2 (en) | 2005-09-30 | 2012-09-18 | Fujifilm Corporation | Method of manufacturing composite structure, impurity removal processing apparatus, film forming apparatus, composite structure and raw material powder |
US8124048B2 (en) | 2006-12-15 | 2012-02-28 | Nippon Light Metal Company, Ltd. | Process for producing high-purity α-alumina |
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