JP2005289791A - Method for producing fine particle alpha-alumina exhibiting high rate of polishing - Google Patents
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本発明は高い研磨速度を示す微粒αアルミナの製造方法に関する。 The present invention relates to a method for producing fine α-alumina exhibiting a high polishing rate.
微粒のαアルミナはαアルミナ分を主成分とするアルミナ〔Ａｌ2Ｏ3〕の微細な粒子であって、研磨剤として広く用いられている。かかる微粒αアルミナの製造方法として、特許文献１〔特開２００３−２７７０４８号公報〕には、アルミニウム塩、アルミニウムアルコキシドなどのαアルミナ前駆体をそのまま焼成する方法が開示されている。同文献に記載の方法によれば、高いα化率で、十分に小さな粒子径で、研磨剤として使用しうる微粒αアルミナを製造することができる。 Fine α-alumina is a fine particle of alumina [Al 2 O 3 ] mainly composed of α-alumina and is widely used as an abrasive. As a method for producing such fine α-alumina, Patent Document 1 (Japanese Patent Laid-Open No. 2003-277048) discloses a method in which an α-alumina precursor such as an aluminum salt or aluminum alkoxide is calcined as it is. According to the method described in this document, it is possible to produce fine α-alumina that can be used as an abrasive with a high α conversion rate and a sufficiently small particle diameter.
しかし、研磨剤として使用される微粒αアルミナには、高いα化率および小粒子径であることと共に、より高い研磨速度を示すものが求められている。 However, fine α-alumina used as an abrasive is required to have a high alpha conversion rate and a small particle diameter, and a higher polishing rate.
そこで本発明者は、α化率が高く、十分に小さい粒子径で、研磨速度の高い微粒αアルミナを製造する方法を開発し得るべく鋭意検討した結果、粉末状非晶質中間アルミナと共に塩分解性塩を含む粉末混合物を加熱して、この塩分解性塩を塩分解したのち、水蒸気分圧６００Ｐａ以下の雰囲気下で１０００℃以下の温度で焼成すれば、高いα化率で、粒子径が小さく、しかも、より高い研磨速度を示す微粒αアルミナが得られることを見出し、本発明に至った。 Therefore, the present inventor has intensively studied to develop a method for producing fine α-alumina having a high α conversion rate, a sufficiently small particle diameter, and a high polishing rate. If the powder mixture containing the salt is heated to decompose the salt-decomposable salt and then calcined at a temperature of 1000 ° C. or less in an atmosphere with a water vapor partial pressure of 600 Pa or less, the particle size is increased with a high alpha conversion rate. The inventors have found that fine α-alumina can be obtained which is small and exhibits a higher polishing rate, and has led to the present invention.
すなわち本発明は、粉末状非晶質中間アルミナおよび塩分解性塩を含む粉末混合物を前記粉末状非晶質中間アルミナがα化しない温度に加熱して前記塩分解性塩を塩分解し、
次いで水蒸気分圧６００Ｐａ以下の雰囲気下で、前記粉末状非晶質中間アルミナがα化しうる温度にて焼成することを特徴とする微粒αアルミナの製造方法を提供するものである。
That is, the present invention heats a powder mixture containing a powdery amorphous intermediate alumina and a salt-decomposable salt to a temperature at which the powdery amorphous intermediate alumina is not alphatized, thereby salt-decomposing the salt-decomposable salt,
Next, the present invention provides a method for producing fine α-alumina, characterized in that the powdered amorphous intermediate alumina is calcined at a temperature at which the powdered amorphous intermediate alumina can be α-ized in an atmosphere having a water vapor partial pressure of 600 Pa or less.
本発明の製造方法により得られる微粒αアルミナは、高いα化率を示し、粒子径が小さいほか、高い研磨速度を示す。 The fine α-alumina obtained by the production method of the present invention exhibits a high alpha conversion rate, a small particle diameter, and a high polishing rate.
本発明の製造方法で使用される粉末状非晶質中間アルミナとは、非晶質のアルミナを主成分とする粉末であって、例えば粉末状のアルミニウム加水分解物が挙げられる。アルミニウム加水分解物は、アルミニウム化合物の溶液を加水分解して得られるものである。 The powdery amorphous intermediate alumina used in the production method of the present invention is a powder mainly composed of amorphous alumina, and examples thereof include powdered aluminum hydrolyzate. The aluminum hydrolyzate is obtained by hydrolyzing a solution of an aluminum compound.
アルミニウム化合物としては、例えばアルミニウム塩が挙げられる。アルミニウム塩とは、アルミニウムと酸との塩であって、酸としては、例えば硝酸、硫酸、炭酸、塩酸などの無機酸、シュウ酸、酢酸、ステアリン酸、乳酸、ラウリン酸などの有機酸などが挙げられる。アルミニウム塩として具体的には、硝酸アルミニウム、硝酸アルミニウムアンモニウムなどのアルミニウム硝酸塩、硫酸アルミニウム、硫酸アルミニウムアンモニウムなどのアルミニウム硫酸塩、炭酸アルミニウム、炭酸アルミニウムアンモニウムなどのアルミニウム炭酸塩、アンモニウムみょうばん、塩化アルミニウムなどのアルミニウム無機塩が挙げられる。またシュウ酸アルミニウム、酢酸アルミニウム、ステアリン酸アルミニウム、乳酸アルミニウム、ラウリン酸アルミニウムなどのアルミニウム有機塩なども挙げられる。これらのアルミニウム塩は水に溶解して水溶液となる。この水溶液は通常、酸性を示すので、この水溶液に、炭酸アンモニウム、炭酸水素アンモニウムなどの塩基を加えることで、加水分解によりアルミニウム加水分解物が生成して沈殿する。加水分解後の加水分解混合物から、溶媒留去、濾過など通常の方法で、このアルミニウム加水分解物を取り出し、乾燥し、必要により粉砕することで、粉末状のアルミニウム加水分解物を得ることができる。 As an aluminum compound, an aluminum salt is mentioned, for example. An aluminum salt is a salt of aluminum and an acid. Examples of the acid include inorganic acids such as nitric acid, sulfuric acid, carbonic acid and hydrochloric acid, and organic acids such as oxalic acid, acetic acid, stearic acid, lactic acid and lauric acid. Can be mentioned. Specific examples of aluminum salts include aluminum nitrates such as aluminum nitrate and aluminum ammonium nitrate, aluminum sulfates such as aluminum sulfate and aluminum ammonium sulfate, aluminum carbonates such as aluminum carbonate and aluminum ammonium carbonate, ammonium alum and aluminum chloride. An aluminum inorganic salt is mentioned. Moreover, aluminum organic salts, such as aluminum oxalate, aluminum acetate, aluminum stearate, aluminum lactate, and aluminum laurate, are also mentioned. These aluminum salts dissolve in water to form an aqueous solution. Since this aqueous solution usually shows acidity, by adding a base such as ammonium carbonate or ammonium hydrogen carbonate to this aqueous solution, an aluminum hydrolyzate is generated by precipitation and precipitated. The aluminum hydrolyzate can be taken out from the hydrolyzed mixture after hydrolysis by a usual method such as solvent distillation, filtration, etc., dried, and pulverized if necessary to obtain a powdered aluminum hydrolyzate. .
また、アルミニウム化合物として、アルミニウムイソプロポキシド、アルミニウムｓ−ブトキシド、アルミニウムｔ−ブトキシドなどのアルミニウムアルコキシドも挙げられる。これらアルミニウムアルコキシドは有機溶媒に溶解して溶液となる。このアルミニウムアルコキシドの有機溶媒溶液に水を加えることで、加水分解によって、アルミニウム加水分解物が生成し、沈殿する。加水分解後の加水分解混合物からは、通常の方法、例えば溶媒留去、濾過などの方法で、アルミニウム加水分解物を取り出し、乾燥し、必要により粉砕することで、粉末状のアルミニウム加水分解物を得ることができる。 Examples of the aluminum compound include aluminum alkoxides such as aluminum isopropoxide, aluminum s-butoxide, and aluminum t-butoxide. These aluminum alkoxides are dissolved in an organic solvent to form a solution. By adding water to the organic solvent solution of the aluminum alkoxide, an aluminum hydrolyzate is generated and precipitated by hydrolysis. From the hydrolysis mixture after hydrolysis, the aluminum hydrolyzate is taken out by a usual method such as solvent distillation, filtration, etc., dried, and pulverized if necessary, so that the powdered aluminum hydrolyzate is obtained. Can be obtained.
塩分解性塩とは、非晶質中間アルミナ粉末がα化しない温度で分解しうる塩である。非晶質中間アルミナは通常６００℃未満ではα化しないので、塩分解性塩として通常は、６００℃未満の温度に加熱することで熱分解するものが用いられる。かかる塩分解性塩としては、例えば硝酸アンモニウム、硫酸アンモニウム、亜硫酸アンモニウム、重硫酸アンモニウム、硫酸水素アンモニウム、塩化アンモニウム、過塩素酸アンモニウム、硫化アンモニウム、チオ硫酸アンモニウム、アミド硫酸アンモニウム、炭酸アンモニウム、炭酸水素アンモニウム、硼酸アンモニウム、などの無機アンモニウム塩、ギ酸アンモニウム、シュウ酸アンモニウム、安息香酸アンモニウム、酢酸アンモニウム、ステアリン酸アンモニウム、乳酸アンモニウム、ラウリン酸アンモニウム、アジピン酸アンモニウム、アルギル酸アンモニウム、酒石酸水素アンモニウム、などの有機アンモニウム塩などが挙げられる。塩分解性塩の使用量は、非晶質中間アルミナ粉末１００質量部あたり通常１０質量部〜９０質量部、好ましくは３０質量部〜８０質量部、より好ましくは４０質量部〜７０質量部程度である。 The salt-decomposable salt is a salt that can be decomposed at a temperature at which the amorphous intermediate alumina powder does not become alpha. Amorphous intermediate alumina usually does not become alpha below 600 ° C., and therefore, a salt-decomposable salt that is thermally decomposed by heating to a temperature below 600 ° C. is usually used. Examples of such salt-decomposable salts include ammonium nitrate, ammonium sulfate, ammonium sulfite, ammonium bisulfate, ammonium hydrogen sulfate, ammonium chloride, ammonium perchlorate, ammonium sulfide, ammonium thiosulfate, ammonium amidosulfate, ammonium carbonate, ammonium hydrogen carbonate, ammonium borate, Inorganic ammonium salts such as ammonium formate, ammonium oxalate, ammonium benzoate, ammonium acetate, ammonium stearate, ammonium lactate, ammonium laurate, ammonium adipate, ammonium alginate, ammonium hydrogen tartrate, etc. Can be mentioned. The amount of salt-decomposable salt used is usually 10 to 90 parts by weight, preferably 30 to 80 parts by weight, more preferably about 40 to 70 parts by weight per 100 parts by weight of the amorphous intermediate alumina powder. is there.
粉末状非晶質中間アルミナおよび塩分解性塩の粉末混合物は、粉末状非晶質中間アルミナと、塩分解性塩とを混合することで得ることができる。 A powder mixture of powdered amorphous intermediate alumina and salt-decomposable salt can be obtained by mixing powdered amorphous intermediate alumina and salt-decomposable salt.
また、粉末状非晶質中間アルミナとして、上記アルミニウムと酸との塩の水溶液に塩基を加えて加水分解して得られる粉末状アルミニウム加水分解物を用いる場合には、酸および塩基として、中和により塩分解性塩を形成しうるものを用い、加水分解後の混合物から水を留去することとすれば、アルミニウム加水分解物に塩分解性塩が均一に混合された粉末混合物を得ることができて好ましい。例えばアルミニウム塩として、アルミニウム硝酸塩、アルミニウム硫酸塩、アルミニウム炭酸塩、塩化アルミニウム、アルミニウム有機塩などを用い、塩基としてアンモニアなどを用いることで、アルミニウム加水分解物と共に、硝酸アンモニウム、硫酸アンモニウム、炭酸アンモニウムなどの無機アンモニウム塩や、有機アンモニウムなどの塩分解性塩が生成するので、加水分解後の混合物から、水を留去し、必要により残渣を粉砕することで、粉末状アルミニウム加水分解物および塩分解性塩を含む粉末混合物を得ることができる。 In addition, when using a powdered aluminum hydrolyzate obtained by adding a base to an aqueous solution of the above-mentioned aluminum and acid salt as a powdered amorphous intermediate alumina and hydrolyzing it, neutralize it as an acid and a base. By using a material that can form a salt-decomposable salt by distilling off water from the hydrolyzed mixture, a powder mixture in which the salt-decomposable salt is uniformly mixed with the aluminum hydrolyzate can be obtained. This is preferable. For example, aluminum nitrate, aluminum sulfate, aluminum carbonate, aluminum chloride, aluminum organic salt, etc. are used as the aluminum salt, and ammonia is used as the base, so that aluminum nitrate, ammonium sulfate, ammonium carbonate, etc., together with aluminum hydrolyzate are used. Since salt-decomposable salts such as ammonium salts and organic ammonium are produced, water is distilled off from the hydrolyzed mixture, and the residue is pulverized to obtain powdered aluminum hydrolyzate and salt-decomposable salt. Can be obtained.
本発明の製造方法では、かかる粉末混合物を加熱して塩分解性塩を塩分解する。塩分解を行う塩分解温度は、粉末状非晶質中間アルミナがα化しない温度である。非晶質中間アルミナは通常６００℃以下でα化するので、通常は６００℃未満の温度で塩分解を行えばよい。塩分解温度は通常１００℃以上、好ましくは３００℃以上である。塩分解温度まで昇温する際の昇温速度は特に限定されないが、通常５０℃／時間以上、好ましくは１００℃／時間以上、通常１０００℃／時間以下、好ましくは５００℃／時間以下程度である。塩分解に要する時間は通常１０分以上２４時間以下、好ましくは３０分以上１０時間以下である。 In the production method of the present invention, such a powder mixture is heated to salt decompose the salt-decomposable salt. The salt decomposition temperature at which salt decomposition is performed is a temperature at which the powdered amorphous intermediate alumina does not become alpha. Amorphous intermediate alumina is normally alphatized at 600 ° C. or lower, and therefore, salt decomposition is usually performed at a temperature lower than 600 ° C. The salt decomposition temperature is usually 100 ° C. or higher, preferably 300 ° C. or higher. The rate of temperature rise when raising the temperature to the salt decomposition temperature is not particularly limited, but is usually 50 ° C./hour or more, preferably 100 ° C./hour or more, usually 1000 ° C./hour or less, preferably about 500 ° C./hour or less. . The time required for the salt decomposition is usually 10 minutes to 24 hours, preferably 30 minutes to 10 hours.
塩分解には、例えば管型電気炉、箱型電気炉、トンネル炉、遠赤外線炉、マイクロ波加熱炉、シャフト炉、反射炉、ロータリー炉、ローラーハース炉などのような炉を用いることができる。塩分解に伴い、ガスが発生するので、このガスを排出しながら加熱することが好ましく、このためには、例えば窒素ガス、アルゴンガスなどの不活性ガスの流通下に塩分解を行えばよい。 For salt decomposition, a furnace such as a tube electric furnace, a box electric furnace, a tunnel furnace, a far infrared furnace, a microwave heating furnace, a shaft furnace, a reflection furnace, a rotary furnace, a roller hearth furnace, etc. can be used. . Since gas is generated with the salt decomposition, it is preferable to heat the gas while discharging it. For this purpose, salt decomposition may be performed under the flow of an inert gas such as nitrogen gas or argon gas.
塩分解後、水蒸気分圧６００Ｐａ、即ち絶対圧力で全圧０．１ＭＰａ（１気圧）であれば露点０℃以下、好ましくは１６５Ｐａ以下、即ち全圧０．１ＭＰａ（絶対圧力）であれば露点−１５℃以下、さらに好ましくは４０Ｐａ以下、即ち全圧０．１ＭＰａ（絶対圧力）であれば露点−３０℃以下の雰囲気下、理想的には水蒸気分圧が０Ｐａで水蒸気を全く含まない雰囲気下で焼成する。水蒸気分圧が６００Ｐａを超えると、十分に高い研磨速度の微粒αアルミナが得られない傾向にある。 After salt decomposition, if the partial pressure of water vapor is 600 Pa, that is, if the absolute pressure is 0.1 MPa (1 atm), the dew point is 0 ° C. or less, preferably 165 Pa or less, that is, if the total pressure is 0.1 MPa (absolute pressure), the dew point − 15 ° C. or lower, more preferably 40 Pa or lower, that is, if the total pressure is 0.1 MPa (absolute pressure), an atmosphere with a dew point of −30 ° C. or lower, ideally an atmosphere with a water vapor partial pressure of 0 Pa and no water vapor. Bake. When the water vapor partial pressure exceeds 600 Pa, there is a tendency that fine α-alumina having a sufficiently high polishing rate cannot be obtained.
焼成時は、空気中で行われてもよいし、窒素ガス、アルゴンガスなどの不活性ガス雰囲気下で行われてもよい。また、雰囲気の全圧は大気圧であってもよいし、加圧状態であってもよいし、減圧状態であってもよい。 The firing may be performed in air or in an inert gas atmosphere such as nitrogen gas or argon gas. The total pressure of the atmosphere may be atmospheric pressure, a pressurized state, or a reduced pressure state.
焼成温度は、非晶質中間アルミナがα化する温度以上、通常は６００℃以上、好ましくは７００℃以上である。α化しない温度で焼成したのでは、微粒αアルミナを得ることができない。また、粒子径の小さな微粒αアルミナが得易い点で、１０００℃以下、さらには９５０℃以下で焼成することが好ましい。 The firing temperature is equal to or higher than the temperature at which the amorphous intermediate alumina is pregelatinized, usually 600 ° C. or higher, preferably 700 ° C. or higher. If it is calcined at a temperature that does not become alpha, fine alpha alumina cannot be obtained. Moreover, it is preferable to calcinate at 1000 ° C. or lower, more preferably 950 ° C. or lower, in that fine α-alumina having a small particle diameter is easily obtained.
焼成温度まで昇温する際の昇温速度は特に限定されないが、通常５０℃／時間以上、好ましくは１００℃／時間以上、通常１０００℃／時間以下、好ましくは５００℃／時間以下程度である。焼成に要する時間は通常１０分以上２４時間以下、好ましくは３０分以上１０時間以下である。 The rate of temperature rise when raising the temperature to the firing temperature is not particularly limited, but is usually 50 ° C./hour or more, preferably 100 ° C./hour or more, usually 1000 ° C./hour or less, preferably about 500 ° C./hour or less. The time required for firing is usually 10 minutes to 24 hours, preferably 30 minutes to 10 hours.
焼成は、雰囲気を水蒸気分圧６００Ｐａ以下に調節できる焼成炉で行えばよく、例えば管型電気炉、箱型電気炉、トンネル炉、遠赤外線炉、マイクロ波加熱炉、シャフト炉、反射炉、ロータリー炉、ローラーハース炉などのような焼成炉を用い、炉内からガスを排出したり、炉内へガスを導入することにより焼成することができる。焼成により非晶質アルミナから水が発生することもあるが、炉内の雰囲気を水蒸気分圧６００Ｐａ以下に保つことができるのであれば、焼成炉は密閉式であってもよい。 Firing may be performed in a firing furnace whose atmosphere can be adjusted to a water vapor partial pressure of 600 Pa or less. For example, a tube electric furnace, a box electric furnace, a tunnel furnace, a far infrared furnace, a microwave heating furnace, a shaft furnace, a reflection furnace, a rotary It can be fired by using a firing furnace such as a furnace or a roller hearth furnace, exhausting gas from the furnace, or introducing gas into the furnace. Although water may be generated from amorphous alumina by firing, the firing furnace may be hermetically sealed as long as the atmosphere in the furnace can be maintained at a water vapor partial pressure of 600 Pa or less.
焼成は種晶の存在下に行われることが好ましい。種晶としては、例えばαアルミナ、ダイアスポア、酸化鉄、酸化クロム、酸化チタンなどの粒子が挙げられ、ＢＥＴ比表面積で１２ｍ2／ｇ以上、さらには１５ｍ2／ｇ以上のものが好ましく用いられる。種晶を用いる場合、その使用量は、焼成後の微粒αアルミナを基準として通常１質量％以上、好ましくは２質量％以上、５０質量％以下、さらに好ましくは５質量％以上３０質量％以下である。 The firing is preferably performed in the presence of seed crystals. Examples of seed crystals include particles such as α-alumina, diaspore, iron oxide, chromium oxide, and titanium oxide, and those having a BET specific surface area of 12 m 2 / g or more, and more preferably 15 m 2 / g or more are preferably used. When the seed crystal is used, the amount used is usually 1% by mass or more, preferably 2% by mass or more and 50% by mass or less, more preferably 5% by mass or more and 30% by mass or less, based on the fine α-alumina after firing. is there.
種晶の存在下に焼成するには、粉末混合物を塩分解した後の混合物に種晶を加えて焼成してもよいし、粉末混合物に種晶を加えて塩分解し、次いで焼成してもよいが、アルミニウム化合物の溶液を加水分解して粉末状非晶質中間アルミナを得る場合には、アルミニウム化合物の溶液に予め種晶を加えておき、この溶液を加水分解することで、粉末状アルミニウム加水分解物に種晶を均一に分散させることができて好ましい。 For firing in the presence of seed crystals, seed powder may be added to the mixture after salt decomposition of the powder mixture and fired, or seed crystals may be added to the powder mixture for salt decomposition and then fired. However, when the powdered amorphous intermediate alumina is obtained by hydrolyzing the aluminum compound solution, a seed crystal is added to the aluminum compound solution in advance, and the solution is hydrolyzed to obtain powdered aluminum. It is preferable because seed crystals can be uniformly dispersed in the hydrolyzate.
かくして得られる微粒αアルミナは、α化率９０％以上、好ましくは９５％以上と高く、粒子径は１０ｎｍ〜２００ｎｍと小さいばかりか、研磨速度が高いので、研磨剤として有用である。 The fine α-alumina thus obtained is useful as an abrasive because it has a high alpha conversion rate of 90% or higher, preferably 95% or higher, a small particle diameter of 10 nm to 200 nm, and a high polishing rate.
以下、実施例によって本発明をより詳細に説明するが、本発明は、これら実施例によって限定されるものではない。 EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by these Examples.
なお、各実施例で得られた微粒αアルミナは、以下の方法で評価した。
(1)α化率
微粒αアルミナのα化率は、粉末Ｘ線回折装置を用いて得た微粒αアルミナの回折スペクトルから、２θ＝２５．６°の位置に現れるアルミナα相（０１２面）のピーク高さ（Ｉ25.6）と、２θ＝４６°の位置に現れるγ相、η相、χ相、κ相、θ相およびδ相のピーク高さ（Ｉ46）とから、式（１）
α化率＝ Ｉ25.6 ／ （Ｉ25.6 ＋ Ｉ46 ）×１００（％）・・・（１）
により算出した。
(2)平均一次粒子径
微粒αアルミナの透過電子顕微鏡写真に写った任意の粒子２０個以上について、個々の一次粒子の定方向最大径を測定し、測定値の数平均値として求めた。
(3)相対研磨速度
各実施例で得た微粒αアルミナ５０ｇと粉砕媒体〔「アルミナボール」、粒子径１５ｍｍ〕５．４Ｋｇを内容積３．３Ｌの容器に入れ、振動ミルにて１２分間振動させて、粉砕する。粉砕後の微粒αアルミナ２質量部を水９８質量部と混合して懸濁させたスラリーを調製し、このスラリーをフェライト単結晶面の上に連続的に供給しながら、研磨して、フェライト単結晶面の単位時間あたりの研磨量を求めた。得られた研磨量は、微粒αアルミナに代えて市販の高純度アルミナ〔「ＡＫＰ−２０」、住友化学(株)製〕を用いたときの研磨量に対する相対比（％）で示した。
(4)ＢＥＴ比表面積
窒素吸着法により比表面積測定装置〔「フローソープII２３００」、(株)島津製作所製〕を用いて測定した。
(5)分散性
微粒αアルミナ１質量部に、水９５質量部、分散剤〔「ＳＮディスパーサント５４６８」、サンノブコ(株)製〕０．０１質量部を加えてスラリーとし、媒体攪拌型ミル〔「１／４Ｇ単筒式サンドグラインダー」、アイメックス(株)製〕にて粉砕媒体として粒径０．６５ｍｍのジルコニアビーズを用いて２０００ｒｐｍ、３０分の条件で、このスラリー中の微粒αアルミナを粉砕したのちの微粒αアルミナの中心粒子径を粒度分布測定機〔「Ｍｉｃｒｏｔｒａｃ」、日機装(株)製〕にて測定して評価した。
(6)種晶（αアルミナ）の粉砕度
粉砕後の種晶（αアルミナ）のα相（１１６）面のＸ線回折ピークの半価幅〔Ｈ(116)〕と、粉砕前の種晶（αアルミナ）のα相（１１６）面のＸ線回折ピークの半価幅〔Ｈ0(116)〕とから、式（２）
粉砕度 ＝ Ｈ(116) ／ Ｈ0(116)・・・（２）
により求めた。
The fine α-alumina obtained in each example was evaluated by the following method.
(1) α conversion rate The α conversion rate of fine α-alumina is the alumina α phase (012 plane) appearing at 2θ = 25.6 ° from the diffraction spectrum of fine α-alumina obtained using a powder X-ray diffractometer. From the peak height (I25.6) and the peak heights (I46) of the γ phase, η phase, χ phase, κ phase, θ phase and δ phase appearing at the position of 2θ = 46 ° (1)
Alpha conversion rate = I25.6 / (I25.6 + I46) x 100 (%) (1)
Calculated by
(2) Average primary particle diameter With respect to 20 or more arbitrary particles shown in a transmission electron micrograph of fine α-alumina, the maximum diameter in the fixed direction of each primary particle was measured and obtained as the number average value of the measured values.
(3) Relative polishing rate 50 g of fine α-alumina obtained in each example and 5.4 kg of grinding media (“alumina ball”, particle diameter 15 mm) were placed in a container having an internal volume of 3.3 L and vibrated for 12 minutes in a vibration mill. And pulverize. A slurry obtained by mixing 2 parts by mass of finely divided α-alumina with 98 parts by mass of water and suspending the slurry was prepared, and the slurry was polished while being continuously supplied onto the ferrite single crystal surface. The polishing amount per unit time of the crystal plane was determined. The obtained polishing amount was shown as a relative ratio (%) to the polishing amount when commercially available high-purity alumina [“AKP-20”, manufactured by Sumitomo Chemical Co., Ltd.] was used instead of fine α-alumina.
(4) BET specific surface area It was measured by a nitrogen adsorption method using a specific surface area measuring device [“Flow Soap II 2300”, manufactured by Shimadzu Corporation].
(5) To 1 part by mass of dispersible fine α-alumina, 95 parts by mass of water and 0.01 parts by mass of a dispersant (“SN Dispersant 5468”, Sannobuco Co., Ltd.) are added to form a slurry. The crushed fine α-alumina in this slurry was crushed using zirconia beads with a particle size of 0.65 mm as a grinding medium at 2000 rpm for 30 minutes using “1 / 4G single cylinder sand grinder” manufactured by Imex Co., Ltd. After that, the central particle diameter of the fine α-alumina was measured and evaluated by a particle size distribution measuring instrument [“Microtrac”, manufactured by Nikkiso Co., Ltd.].
(6) Grinding degree of seed crystal (α-alumina) Half width [H (116)] of X-ray diffraction peak of α phase (116) surface of seed crystal (α-alumina) after grinding, and seed crystal before grinding From the half width [H 0 (116)] of the X-ray diffraction peak of the α phase (116) surface of (α alumina), the formula (2)
Grinding degree = H (116) / H 0 (116) (2)
Determined by
実施例１
〔種晶スラリーの製造〕
アルミニウムイソプロポキシドを加水分解して得られた水酸化アルミニウムを仮焼して、主結晶相がθ相であり、α相を３重量％含む中間アルミナを得、この中間アルミナをジェットミルにて粉砕して、嵩密度０．２１ｇ／ｃｍ3の粉末を得た。
Example 1
[Production of seed crystal slurry]
Aluminum hydroxide obtained by hydrolysis of aluminum isopropoxide is calcined to obtain an intermediate alumina whose main crystal phase is the θ phase and 3% by weight of the α phase, and this intermediate alumina is obtained by a jet mill. By grinding, a powder having a bulk density of 0.21 g / cm 3 was obtained.
炉内が露点−１５℃〔水蒸気分圧１６５Ｐａ〕の乾燥空気で満たされた雰囲気炉に上記で得た粉末を連続的に投入しながら、平均滞留時間３時間で連続的に取り出して、最高温度１１７０℃にて焼成して、ＢＥＴ比表面積１４ｍ2／ｇのαアルミナ粒子を得た。 While continuously putting the powder obtained above into an atmospheric furnace filled with dry air having a dew point of −15 ° C. [water vapor partial pressure of 165 Pa], the furnace was continuously taken out with an average residence time of 3 hours, and the maximum temperature Firing was performed at 1170 ° C. to obtain α-alumina particles having a BET specific surface area of 14 m 2 / g.
このαアルミナ粒子１００質量部あたり１質量部の粉砕助剤（プロピレングリコール）を加え、粉砕媒体として直径１５ｍｍのアルミナビーズを加えて振動ミルにて１２時間粉砕して、ＢＥＴ比表面積１７．２ｍ2／ｇ、粉砕度１．１０の種晶（αアルミナ粒子）を得た。 1 part by mass of a grinding aid (propylene glycol) is added per 100 parts by mass of the α-alumina particles, alumina beads having a diameter of 15 mm are added as a grinding medium, and the mixture is pulverized with a vibration mill for 12 hours to obtain a BET specific surface area of 17.2 m 2. / G, seed crystals (α alumina particles) having a pulverization degree of 1.10 were obtained.
上記で得たαアルミナ粒子（粒子径は約０．１μｍ）３７．５ｇを、濃度０．０１モル／Ｌの硝酸アルミニウム水溶液１５０ｇに添加し分散させた後、アルミナビーズ（直径２ｍｍ）７００ｇと共に、１Ｌのポリ容器に充填し、攪拌したのち、濾過操作によりアルミナビーズを除去して、種晶スラリーを得た。 After adding and dispersing 37.5 g of the α alumina particles obtained above (particle diameter is about 0.1 μm) in 150 g of an aluminum nitrate aqueous solution having a concentration of 0.01 mol / L, together with 700 g of alumina beads (diameter 2 mm), After filling a 1 L plastic container and stirring, the alumina beads were removed by a filtration operation to obtain a seed crystal slurry.
〔粉末混合物の製造〕
硝酸アルミニウム（Ａｌ(ＮＯ3)3・９Ｈ2Ｏ）〔関西触媒化学社製、１級、粉末状〕７５０．２６ｇ（２モル）を純水１５５５．７ｇに溶解させて硝酸アルミニウム水溶液を得た。この硝酸アルミニウム水溶液に上記で得た種晶スラリー５６．６７ｇ（αアルミナ粒子１１．３３ｇ）を添加し、室温で攪拌しながらマイクロロータリーポンプにて２５％アンモニア水〔和光純薬工業社製、特級〕３４０．４６ｇ（アンモニア（ＮＨ3）として８５．１２ｇ）を３２ｇ／分の速度で添加した。添加終了後の混合物の水素イオン濃度はｐＨ３．８であった。この混合物を室温で放置した後、６０℃で乾燥させ、乳鉢で粉砕して、アルミニウム加水分解物と硝酸アンモニウムとの粉末混合物を得た。この粉末混合物には、金属成分の酸化物換算で１００質量部あたり１０質量部の種晶（αアルミナ粒子）が含まれている。
[Production of powder mixture]
Aluminum nitrate aqueous solution was obtained by dissolving 750.26 g (2 mol) of aluminum nitrate (Al (NO 3 ) 3 .9H 2 O) (manufactured by Kansai Kagaku Kagaku Kabushiki Kaisha, grade 1, powder) in 1555.7 g of pure water. . To this aluminum nitrate aqueous solution, 56.67 g of seed crystal slurry obtained above (11.33 g of α-alumina particles) was added and 25% aqueous ammonia (made by Wako Pure Chemical Industries, special grade) with a micro rotary pump while stirring at room temperature. 340.46 g (85.12 g as ammonia (NH 3 )) was added at a rate of 32 g / min. The hydrogen ion concentration of the mixture after the addition was pH 3.8. The mixture was allowed to stand at room temperature, dried at 60 ° C., and pulverized in a mortar to obtain a powder mixture of aluminum hydrolyzate and ammonium nitrate. This powder mixture contains 10 parts by mass of seed crystals (α-alumina particles) per 100 parts by mass in terms of oxide of the metal component.
〔塩分解〕
上記で得た粉末混合物を内容積７９３８２ｃｍ3のロータリー炉〔高砂工業(株)製〕にて連続的に塩分解した。ロータリー炉への粉末混合物の供給速度は３０ｇ／分で、塩分解後の粉末を連続的に取り出した。炉内温度は、粉末混合物の入口で３９０℃とし、塩分解後の粉末の取出口は４９０℃とした。炉内は、予め窒素ガスで置換し、塩分解中は常に１０Ｌ／分（大気圧換算）で窒素ガスを流通させた。
[Salt decomposition]
The powder mixture obtained above was continuously subjected to salt decomposition in a rotary furnace (manufactured by Takasago Industry Co., Ltd.) having an internal volume of 79382 cm 3 . The feed rate of the powder mixture to the rotary furnace was 30 g / min, and the powder after salt decomposition was continuously taken out. The furnace temperature was 390 ° C. at the inlet of the powder mixture, and the outlet of the powder after salt decomposition was 490 ° C. The inside of the furnace was previously replaced with nitrogen gas, and nitrogen gas was always circulated at 10 L / min (in terms of atmospheric pressure) during salt decomposition.
〔焼成〕
塩分解後の粉末をアルミナ製るつぼに入れ、水蒸気分圧１３Ｐａの乾燥空気の流通下に、３００℃／時間の昇温速度で９４０℃に昇温し、同温度で３時間保持して焼成して、微粒αアルミナを得た。この微粒αアルミナの評価結果を第１表に示す。
[Baking]
The salt-decomposed powder is put in an alumina crucible, heated to 940 ° C. at a heating rate of 300 ° C./hour under a flow of dry air having a water vapor partial pressure of 13 Pa, and held at that temperature for 3 hours for firing. Thus, fine α-alumina was obtained. The evaluation results of this fine α-alumina are shown in Table 1.
実施例２
〔粉末混合物の製造〕
実施例１と同様に操作して得た硝酸アルミニウム水溶液に、実施例１と同様に操作して得た種晶スラリー２１８．５７ｇ〔αアルミナ粒子４３．７１ｇ〕を添加し、室温で攪拌しながらマイクロロータリーポンプにて２５％アンモニア水（和光純薬工業社製、特級）４０ｇ（アンモニア（ＮＨ3）として１０ｇ）を３２ｇ／分の速度で添加した。添加終了後の混合物の水素イオン濃度はｐＨ３．８であった。この混合物を室温で放置した後、６０℃で乾燥させ、乳鉢で粉砕して、アルミニウム加水分解物と硝酸アンモニウムとの粉末混合物を得た。この粉末混合物には、金属成分の酸化物換算で１００質量部あたり３０質量部の種晶（αアルミナ粒子）が含まれている。
Example 2
[Production of powder mixture]
To the aluminum nitrate aqueous solution obtained by operating in the same manner as in Example 1, 218.57 g [α alumina particles 43.71 g] of the seed crystal slurry obtained by operating in the same manner as in Example 1 was added while stirring at room temperature. 40 g of 25% aqueous ammonia (special grade, manufactured by Wako Pure Chemical Industries, Ltd.) (10 g as ammonia (NH 3 )) was added at a rate of 32 g / min with a micro rotary pump. The hydrogen ion concentration of the mixture after the addition was pH 3.8. The mixture was allowed to stand at room temperature, dried at 60 ° C., and pulverized in a mortar to obtain a powder mixture of aluminum hydrolyzate and ammonium nitrate. This powder mixture contains 30 parts by mass of seed crystals (α alumina particles) per 100 parts by mass in terms of oxide of the metal component.
〔塩分解〕
実施例１で得た粉末混合物に代えて、上記で得た粉末混合物を用いる以外は実施例１と同様に操作して塩分解した。
[Salt decomposition]
Instead of the powder mixture obtained in Example 1, salt decomposition was carried out in the same manner as in Example 1 except that the powder mixture obtained above was used.
〔焼成〕
実施例１で得た塩分解した後の粉末に代えて上記で塩分解した粉末を用い、焼成温度９２０℃で焼成した以外は実施例１と同様に操作して、微粒αアルミナを得た。この微粒αアルミナの評価結果を第１表に示す。
[Baking]
A fine α-alumina was obtained in the same manner as in Example 1 except that the salt-decomposed powder obtained in Example 1 was used instead of the salt-decomposed powder and calcined at a calcining temperature of 920 ° C. The evaluation results of this fine α-alumina are shown in Table 1.
比較例１
〔粉末混合物の製造〕
実施例１と同様に操作して得た硝酸アルミニウム水溶液に、実施例１で得た種晶スラリー５６．６７ｇ〔αアルミナ粒子１１．３３ｇ〕を添加し、室温で攪拌しながらマイクロロータリーポンプにて２５％アンモニア水（和光純薬工業社製、特級）４０ｇ（アンモニア（ＮＨ3）として１０ｇ）を３２ｇ／分の速度で添加した。添加終了後の混合物の水素イオン濃度はｐＨ３．８であった。この混合物を室温で放置した後、６０℃で乾燥させ、乳鉢で粉砕して、アルミニウム加水分解物と硝酸
アンモニウムとの粉末混合物を得た。この粉末混合物には、金属成分の酸化物換算で１００質量部あたり１０質量部の種晶（αアルミナ粒子）が含まれている。
Comparative Example 1
[Production of powder mixture]
56.67 g of seed crystal slurry obtained in Example 1 [11.33 g of α-alumina particles] was added to an aluminum nitrate aqueous solution obtained in the same manner as in Example 1, and the mixture was stirred at room temperature with a micro rotary pump. 40 g of 25% aqueous ammonia (manufactured by Wako Pure Chemical Industries, Ltd., special grade) (10 g as ammonia (NH 3 )) was added at a rate of 32 g / min. The hydrogen ion concentration of the mixture after the addition was pH 3.8. The mixture was allowed to stand at room temperature, dried at 60 ° C., and pulverized in a mortar to obtain a powder mixture of an aluminum hydrolyzate and ammonium nitrate. This powder mixture contains 10 parts by mass of seed crystals (α-alumina particles) per 100 parts by mass in terms of oxide of the metal component.
〔塩分解および焼成〕
実施例１で得た粉末混合物に代えて上記で得た粉末混合物を用いる以外は実施例１と同様に操作して塩分解し、次いで塩分解後の粉末を水蒸気分圧１２００Ｐａの空気中で焼成する以外は実施例１と同様に操作して、微粒αアルミナを得た。この微粒αアルミナの評価結果を第１表に示す。
[Salt decomposition and calcination]
Except for using the powder mixture obtained in Example 1 instead of the powder mixture obtained in Example 1, salt decomposition was carried out in the same manner as in Example 1, and then the powder after salt decomposition was calcined in air having a water vapor partial pressure of 1200 Pa. Except that, fine α-alumina was obtained in the same manner as in Example 1. The evaluation results of this fine α-alumina are shown in Table 1.
比較例２
〔粉末混合物の製造〕
アルミニウムイソプロポキシドのイソプロパノール溶液に水を加えて加水分解して得られたアルミニウム加水分解物を乾燥し、仮焼し、粉砕してθアルミナ分を主成分とするα化率３％の中間アルミナ粉末を得た。
Comparative Example 2
[Production of powder mixture]
An aluminum hydrolyzate obtained by adding water to an isopropanol solution of aluminum isopropoxide and hydrolyzing it is dried, calcined, pulverized, and intermediate alumina having a 3% alpha conversion rate mainly composed of θ alumina. A powder was obtained.
〔焼成〕
上記で得た中間アルミナ粉末１００ｇを内容積８Ｌの管型焼成炉〔(株)モトヤマ製〕に入れ、水蒸気分圧１６５Ｐａの乾燥空気を１Ｌ／分（大気圧換算）で流通させながら１１７０℃に加熱し、同温度で３時間保持して焼成して、微粒αアルミナを得た。この微粒αアルミナの評価結果を第１表に示す。
[Baking]
100 g of the intermediate alumina powder obtained above was placed in a tube-type firing furnace (manufactured by Motoyama Co., Ltd.) having an internal volume of 8 L, and dried air having a water vapor partial pressure of 165 Pa was circulated at 1 L / min (at atmospheric pressure) to 1170 ° C. The mixture was heated, held at the same temperature for 3 hours and fired to obtain fine α-alumina. The evaluation results of this fine α-alumina are shown in Table 1.
比較例３
市販の微粒αアルミナ粉末〔「ＨＩＴ５０」、住友化学(株)製〕を評価した。結果を第１表に示す。
Comparative Example 3
A commercially available fine α-alumina powder [“HIT50”, manufactured by Sumitomo Chemical Co., Ltd.] was evaluated. The results are shown in Table 1.
比較例４
市販の微粒αアルミナ粉末〔「ＨＩＴ１００」、住友化学(株)製〕を評価した。結果を第１表に示す。
Comparative Example 4
A commercially available fine α-alumina powder [“HIT100”, manufactured by Sumitomo Chemical Co., Ltd.] was evaluated. The results are shown in Table 1.
第 １ 表
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
α化率 粒子径 ＢＥＴ比表面積 相対研磨速度 分散性
（％） (μｍ) （ｍ2／ｇ） （％） (μｍ)
─────────────────────────────────────
実施例１ ９７．３ １０７ １６．８ ２１１ ０．１７３
実施例２ ９７．０ ８５ ２０．３ ４１５ ０．１８４
比較例１ ９７．３ １０２ １６．８ １３５ ０．１９８
比較例２ ９８．０ − １６．０ １００ ０．１８８
比較例３ ９９．０ − ８．５ ５００ ０．３０３
比較例４ ９５．６ − ３０ ２００ ０．２１８
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Table 1
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Alpha conversion rate Particle size BET specific surface area Relative polishing rate Dispersibility
(%) (Μm) (m 2 / g) (%) (μm)
─────────────────────────────────────
Example 1 97.3 107 16.8 211 0.173
Example 2 97.0 85 20.3 415 0.184
Comparative Example 1 97.3 102 16.8 135 0.198
Comparative Example 2 98.0-16.0 100 0.188
Comparative Example 3 99.0-8.5 500 0.303
Comparative Example 4 95.6-30 200 0.218
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009501688A (en) * | 2005-07-16 | 2009-01-22 | センター フォー アブレイシブズ アンド リフラクトリーズ リサーチ アンド ディベロップメント シー．エー．アール．アール．ディー． ゲーエムベーハー | Alpha-aluminum oxide-based nanocrystal sintered body, method for producing the same, and use thereof |
| CN102259902A (en) * | 2011-06-20 | 2011-11-30 | 武汉科技大学 | Superfine alpha-Al2O3 powder and preparation method thereof |
| CN107758715A (en) * | 2017-10-13 | 2018-03-06 | 新疆众和股份有限公司 | A kind of method for preparing high-crystallinity high-purity boehmite |
| CN115180641A (en) * | 2022-04-13 | 2022-10-14 | 河南天马新材料股份有限公司 | Method for preparing flaky alumina powder by explosion method |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10101329A (en) * | 1996-09-30 | 1998-04-21 | Sumitomo Chem Co Ltd | Alpha-alumina and its production |
| JP2000344516A (en) * | 1999-06-04 | 2000-12-12 | Ushio Inc | PRODUCTION OF alpha-ALUMINA POWDER |
| JP2005001985A (en) * | 2003-05-19 | 2005-01-06 | Sumitomo Chemical Co Ltd | METHOD OF FINE PARTICULATE alpha-ALUMINA |
| JP2005001984A (en) * | 2003-05-19 | 2005-01-06 | Sumitomo Chemical Co Ltd | METHOD OF FINE PARTICULATE alpha-ALUMINA |
| JP2005044402A (en) * | 2003-07-23 | 2005-02-17 | Sumitomo Chemical Co Ltd | alpha ALUMINA POWDER FOR MAGNETIC RECORDING MEDIUM |
| JP2005097075A (en) * | 2003-03-04 | 2005-04-14 | Sumitomo Chemical Co Ltd | Method for producing alpha-alumina particulate |
| JP2005179116A (en) * | 2003-12-19 | 2005-07-07 | Sumitomo Chemical Co Ltd | METHOD FOR MANUFACTURING PARTICULATE of alpha-ALUMINA |
-
2005
- 2005-01-05 JP JP2005000528A patent/JP4720182B2/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH10101329A (en) * | 1996-09-30 | 1998-04-21 | Sumitomo Chem Co Ltd | Alpha-alumina and its production |
| JP2000344516A (en) * | 1999-06-04 | 2000-12-12 | Ushio Inc | PRODUCTION OF alpha-ALUMINA POWDER |
| JP2005097075A (en) * | 2003-03-04 | 2005-04-14 | Sumitomo Chemical Co Ltd | Method for producing alpha-alumina particulate |
| JP2005001985A (en) * | 2003-05-19 | 2005-01-06 | Sumitomo Chemical Co Ltd | METHOD OF FINE PARTICULATE alpha-ALUMINA |
| JP2005001984A (en) * | 2003-05-19 | 2005-01-06 | Sumitomo Chemical Co Ltd | METHOD OF FINE PARTICULATE alpha-ALUMINA |
| JP2005044402A (en) * | 2003-07-23 | 2005-02-17 | Sumitomo Chemical Co Ltd | alpha ALUMINA POWDER FOR MAGNETIC RECORDING MEDIUM |
| JP2005179116A (en) * | 2003-12-19 | 2005-07-07 | Sumitomo Chemical Co Ltd | METHOD FOR MANUFACTURING PARTICULATE of alpha-ALUMINA |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009501688A (en) * | 2005-07-16 | 2009-01-22 | センター フォー アブレイシブズ アンド リフラクトリーズ リサーチ アンド ディベロップメント シー．エー．アール．アール．ディー． ゲーエムベーハー | Alpha-aluminum oxide-based nanocrystal sintered body, method for producing the same, and use thereof |
| CN102259902A (en) * | 2011-06-20 | 2011-11-30 | 武汉科技大学 | Superfine alpha-Al2O3 powder and preparation method thereof |
| CN107758715A (en) * | 2017-10-13 | 2018-03-06 | 新疆众和股份有限公司 | A kind of method for preparing high-crystallinity high-purity boehmite |
| CN107758715B (en) * | 2017-10-13 | 2020-10-09 | 新疆众和股份有限公司 | Method for preparing high-crystallinity high-purity pseudo-boehmite |
| CN115180641A (en) * | 2022-04-13 | 2022-10-14 | 河南天马新材料股份有限公司 | Method for preparing flaky alumina powder by explosion method |
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