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METHOD FOR PRODUCING α-ALUMINUM OXIDE PARTICLE, AND α-ALUMINUM OXIDE PARTICLE commons meetings

Foreign code F190009789
File No. (GI-H29-03,S2017-1028-N0)
Posted date May 7, 2019
Country WIPO
International application number 2018JP030058
International publication number WO 2019039321
Date of international filing Aug 10, 2018
Date of international publication Feb 28, 2019
Priority data
  • P2017-161397 (Aug 24, 2017) JP
Title METHOD FOR PRODUCING α-ALUMINUM OXIDE PARTICLE, AND α-ALUMINUM OXIDE PARTICLE commons meetings
Abstract Provided are: a method for producing an α-aluminum oxide particle, whereby a particle having a smaller particle size and high dispersibility can be produced with high purity; and an α-aluminum oxide particle produced by the production method. An α-aluminum oxide particle having a Feret diameter of at least 2 nm and less than 20 nm and a circularity of 0.82-0.86 is produced by a production method in which amorphous aluminum hydroxide, water, and carboxylic acid are mixed and stirred to prepare a precursor sol of α-aluminum oxide, and the undried precursor sol or a dried matter of the precursor sol is rapidly heated for 0.1-60 seconds from room temperature to a temperature range of 1000-1200°C, and the rapidly heated matter is rapidly cooled for 1 second to 10 minutes from the temperature range of 1000-1200°C to a temperature range of room temperature to 100°C.
Outline of related art and contending technology BACKGROUND ART
Α - (α - alumina, corundum) is aluminum oxide, a high hardness, electrical insulation, chemical stability, mechanical strength and good balance of properties, a high number of the sub material constituted by an element because, as the ceramic material can be relatively inexpensive and easily available from the, a very widely used in industry is one of a ceramic material.
Is a general method for manufacturing the aluminum oxide of the α -, gibbsite, bayerite, nordstrandite such as aluminum hydroxide, boehmite (AlO (OH) ) by heating, γ - alumina, δ - alumina, η - alumina, κ - alumina, ρ - alumina, an intermediate alumina such as alumina through χ -, α - is generated in the aluminum oxide. In this way via the intermediate aluminum oxide in order to generate the α -, and firing conditions are determined by the difference between the starting material, generation of the various routes are known. However, it may be generated through a route, in order to generate the α - aluminum oxide, about 1300°C or more in the prior art has been fired at high temperature. Such a high temperature when firing for a long time, the crystals of aluminum oxide generated by the α -, polymer growth through more than 1μm and particle size are known.
On the other hand, bond with the particles of the ceramics becomes, the larger particles having a particle diameter is not the appearance of a characteristic, the intermediate layer of the isolation film or a translucent material such as new applications are created from, conventionally, a finer particles have been attempted. As described above is widely used in the industry for α - aluminum oxide, it is required that the finer particles and, using various manufacturing methods have been tried.
For example, 60°C or less of the hydrolysis of the aluminum hydrolysates dispersed seed crystal, 950°C or less by heating, necking of the particles are small in the method of producing the aluminum oxide has been proposed (see Patent Document 1). However, Patent Document 1 is an aluminum oxide obtained by the method of the α -, primary particles of 50nm or more is grown on, strongly aggregated and the aggregate of 200nm or more. (Low dispersion) and strong aggregation, even if the primary particles as small, the characteristics of the fine particles does not exhibit bring.
In addition, an aluminum alkoxide as a raw material by a sol-gel method in the case of producing α - aluminum oxide, by adding a surfactant, 20nm-30nm of particles has been reported (Non-Patent Document 1). However, in the technique of Non-Patent Document 1, sodium dodecyl benzene sulfonate (SDBS) surfactant such as bis (2-ethylhexyl) sodium sulfosuccinate (Na (AOT) ) was used, after firing of the aluminum oxide remains as an impurity element other than constituent elements. In particular, alkali metal such as sodium, the ceramic at a high temperature greatly affects the characteristics.
Scope of claims (In Japanese)請求の範囲 [請求項1]
 非晶質の水酸化アルミニウム、水、及び、カルボン酸を混合・撹拌することにより、α-酸化アルミニウムの前駆体ゾルを調製し、
 乾燥させていない前記前駆体ゾルまたは前記前駆体ゾルの乾燥物を、常温から1000℃~1200℃の温度域まで所要時間0.1秒~60秒で急速加熱し、
 急速加熱後の処理物を、1000℃~1200℃の温度域から常温~100℃の温度域まで所要時間1秒~10分で急速冷却することにより、
 フェレ径が2nm以上20nm未満であるα-酸化アルミニウム粒子を製造する
ことを特徴とするα-酸化アルミニウム粒子の製造方法。

[請求項2]
 前記急速加熱は、乾燥させていない前記前駆体ゾルをミスト状にして温度1000℃~1200℃の雰囲気に噴霧することにより行い、
 前記急速冷却は、前記急速加熱により生成したα-酸化アルミニウム粒子を、温度1000℃~1200℃の雰囲気外に落下させて冷却することにより行う
ことを特徴とする請求項1に記載のα-酸化アルミニウム粒子の製造方法。

[請求項3]
 前記急速加熱は、乾燥させていない前記前駆体ゾルをミスト状にして温度1000℃~1200℃のバーナーによる加熱域に吹き付けることにより行い、
 前記急速冷却は、前記急速加熱により生成したα-酸化アルミニウム粒子を、前記バーナーによる加熱域外に落下させて冷却することにより行う
ことを特徴とする請求項1に記載のα-酸化アルミニウム粒子の製造方法。

[請求項4]
 非晶質の水酸化アルミニウム、水、及び、カルボン酸を混合・撹拌することにより、α-酸化アルミニウムの前駆体ゾルを調製し、
 乾燥させていない前記前駆体ゾルまたは前記前駆体ゾルの乾燥物を収容させた容器を、常温から1000℃~1200℃の温度域まで、所要時間0.1秒~60秒で移動させることにより急速加熱し、
 急速加熱後の処理物を収容している前記容器を、1000℃~1200℃の温度域から常温~100℃の温度域まで、所要時間1秒~10分で移動させて急速冷却することにより、
 フェレ径が2nm以上20nm未満であるα-酸化アルミニウム粒子を製造する
ことを特徴とするα-酸化アルミニウム粒子の製造方法。

[請求項5]
 フェレ径が2nm以上20nm未満であり、
 円形度が0.82~0.86である
ことを特徴とするα-酸化アルミニウム粒子。

[請求項6]
 個数割合で少なくとも90%の粒子のフェレ径が10nm未満である
ことを特徴とする請求項3に記載のα-酸化アルミニウム粒子。

  • Applicant
  • ※All designated countries except for US in the data before July 2012
  • GIFU UNIVERSITY
  • Inventor
  • YOSHIDA Michiyuki
  • SAKURADA Osamu
IPC(International Patent Classification)
Specified countries National States: AE AG AL AM AO AT AU AZ BA BB BG BH BN BR BW BY BZ CA CH CL CN CO CR CU CZ DE DJ DK DM DO DZ EC EE EG ES FI GB GD GE GH GM GT HN HR HU ID IL IN IR IS JO JP KE KG KH KN KP KR KW KZ LA LC LK LR LS LU LY MA MD ME MG MK MN MW MX MY MZ NA NG NI NO NZ OM PA PE PG PH PL PT QA RO RS RU RW SA SC SD SE SG SK SL SM ST SV SY TH TJ TM TN TR TT TZ UA UG US UZ VC VN ZA ZM ZW
ARIPO: BW GH GM KE LR LS MW MZ NA RW SD SL SZ TZ UG ZM ZW
EAPO: AM AZ BY KG KZ RU TJ TM
EPO: AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR
OAPI: BF BJ CF CG CI CM GA GN GQ GW KM ML MR NE SN ST TD TG
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