JPH05105419A - Production of spherical ceramic powder - Google Patents
Production of spherical ceramic powderInfo
- Publication number
- JPH05105419A JPH05105419A JP3120113A JP12011391A JPH05105419A JP H05105419 A JPH05105419 A JP H05105419A JP 3120113 A JP3120113 A JP 3120113A JP 12011391 A JP12011391 A JP 12011391A JP H05105419 A JPH05105419 A JP H05105419A
- Authority
- JP
- Japan
- Prior art keywords
- ceramic powder
- spherical
- powder
- sol
- alumina
- 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
- 239000000919 ceramic Substances 0.000 title claims abstract description 54
- 239000000843 powder Substances 0.000 title claims abstract description 53
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 239000002245 particle Substances 0.000 claims abstract description 34
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims abstract description 24
- 238000010304 firing Methods 0.000 claims abstract description 13
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 claims abstract description 12
- 239000006185 dispersion Substances 0.000 claims abstract description 10
- 239000007787 solid Substances 0.000 claims abstract description 7
- 238000005507 spraying Methods 0.000 claims description 10
- 239000007788 liquid Substances 0.000 claims description 6
- 229910004298 SiO 2 Inorganic materials 0.000 claims description 4
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract description 11
- 230000002776 aggregation Effects 0.000 abstract description 11
- 238000004220 aggregation Methods 0.000 abstract description 5
- 239000000377 silicon dioxide Substances 0.000 abstract description 5
- 239000000203 mixture Substances 0.000 abstract description 4
- 229910052681 coesite Inorganic materials 0.000 abstract 1
- 229910052593 corundum Inorganic materials 0.000 abstract 1
- 229910052906 cristobalite Inorganic materials 0.000 abstract 1
- 239000003595 mist Substances 0.000 abstract 1
- 235000012239 silicon dioxide Nutrition 0.000 abstract 1
- 229910052682 stishovite Inorganic materials 0.000 abstract 1
- 229910052905 tridymite Inorganic materials 0.000 abstract 1
- 229910001845 yogo sapphire Inorganic materials 0.000 abstract 1
- KZHJGOXRZJKJNY-UHFFFAOYSA-N dioxosilane;oxo(oxoalumanyloxy)alumane Chemical compound O=[Si]=O.O=[Si]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O.O=[Al]O[Al]=O KZHJGOXRZJKJNY-UHFFFAOYSA-N 0.000 description 19
- 229910052863 mullite Inorganic materials 0.000 description 19
- 230000000052 comparative effect Effects 0.000 description 16
- 238000000034 method Methods 0.000 description 9
- 239000011148 porous material Substances 0.000 description 7
- 239000007921 spray Substances 0.000 description 7
- 238000005054 agglomeration Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000002425 crystallisation Methods 0.000 description 4
- 230000008025 crystallization Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 238000005245 sintering Methods 0.000 description 4
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 3
- 229910001593 boehmite Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- FAHBNUUHRFUEAI-UHFFFAOYSA-M hydroxidooxidoaluminium Chemical compound O[Al]=O FAHBNUUHRFUEAI-UHFFFAOYSA-M 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 238000010298 pulverizing process Methods 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 239000007864 aqueous solution Substances 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- 238000005118 spray pyrolysis Methods 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- MXRIRQGCELJRSN-UHFFFAOYSA-N O.O.O.[Al] Chemical compound O.O.O.[Al] MXRIRQGCELJRSN-UHFFFAOYSA-N 0.000 description 1
- BOTDANWDWHJENH-UHFFFAOYSA-N Tetraethyl orthosilicate Chemical compound CCO[Si](OCC)(OCC)OCC BOTDANWDWHJENH-UHFFFAOYSA-N 0.000 description 1
- 229910001570 bauxite Inorganic materials 0.000 description 1
- 229910001680 bayerite Inorganic materials 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000001273 butane Substances 0.000 description 1
- 238000001354 calcination Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 229910003460 diamond Inorganic materials 0.000 description 1
- 239000010432 diamond Substances 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000010419 fine particle Substances 0.000 description 1
- -1 for example Chemical compound 0.000 description 1
- 235000019253 formic acid Nutrition 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 229910021485 fumed silica Inorganic materials 0.000 description 1
- 230000004927 fusion Effects 0.000 description 1
- 229910001679 gibbsite Inorganic materials 0.000 description 1
- 239000012442 inert solvent Substances 0.000 description 1
- 150000007522 mineralic acids Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 1
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 150000007524 organic acids Chemical class 0.000 description 1
- 239000003208 petroleum Substances 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 239000007858 starting material Substances 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
- Silicates, Zeolites, And Molecular Sieves (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、例えば構造用セラミッ
クスや電子回路用絶縁セラミックス等を製造するのに適
したムライト系のセラミックス球状粉末の製造方法に関
するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a mullite ceramic spherical powder suitable for producing structural ceramics, insulating ceramics for electronic circuits and the like.
【０００２】[0002]
【従来の技術】セラミックス粉末を成形、焼成してセラ
ミックス焼結体を得るに際して、出発原料であるセラミ
ックス粉末の純度がセラミックス焼結体の特性に大きな
影響を与えていることは周知の通りである。しかし、純
度のみではなくセラミックス粉末の粒子形状、粒子サイ
ズ、比表面積、凝集の程度といった物性もセラミックス
焼結体の特性に大きな影響を与えることが知られてい
る。2. Description of the Related Art It is well known that when a ceramic powder is molded and fired to obtain a ceramic sintered body, the purity of the starting ceramic powder has a great influence on the characteristics of the ceramic sintered body. .. However, it is known that not only the purity but also the physical properties such as the particle shape, particle size, specific surface area, and degree of aggregation of the ceramic powder have a great influence on the characteristics of the ceramic sintered body.
【０００３】例えば、セラミックス粉末の粒子形状につ
いて考察して見ると、一般的には球状であることが好ま
しい。すなわち、粉砕により粒度調整された粉末のよう
に粒子形状に異方性があると、つまり球形から外れる
程、成形体の密度が不均一となり、焼結される時に起き
る収縮に異方性が生じ易く、また焼成による変形、歪み
も大きくなる。一方、球状粉末では、成形時の粒子同士
の滑りが良いため、充填性に優れ、成形体の密度は大き
く、均一であるため、焼成収縮も等方的である。従っ
て、出発原料のセラミック粉末は球状であることが好ま
しいのである。For example, considering the particle shape of the ceramic powder, it is generally preferable that it is spherical. That is, if the particle shape is anisotropic, such as the powder whose particle size has been adjusted by pulverization, that is, the more it deviates from the spherical shape, the more uneven the density of the molded body becomes, and the anisotropic shrinkage that occurs during sintering occurs. It is easy, and the deformation and distortion due to firing become large. On the other hand, in the case of spherical powder, since the particles slide well during molding, the filling property is excellent, and the density of the molded body is large and uniform, so that the firing shrinkage is isotropic. Therefore, the starting ceramic powder is preferably spherical.
【０００４】又、一般にセラミックス粉末の粒子サイズ
が小さい程比表面積は大きくなり、その活性度は高くな
ってより低い温度で焼結が始まる。しかしながら、セラ
ミックス粉末の粒子サイズが小さい程嵩高いものとな
り、成形時の密度は低くなるので、焼成収縮が大きく、
変形やひび割れが発生しやすく、寸法精度が悪くなる。
一方、セラミックス粉末の粒子サイズが大きくなる程比
表面積は小さくなり、成形し易くなるものの、活性度は
低くなり、焼き締まりが不十分なものとなる。Further, generally, the smaller the particle size of the ceramic powder, the larger the specific surface area, the higher its activity, and the sintering starts at a lower temperature. However, the smaller the particle size of the ceramic powder, the more bulky it becomes, and the lower the density at the time of molding becomes, so that the firing shrinkage is large,
Deformation and cracks are likely to occur, resulting in poor dimensional accuracy.
On the other hand, the larger the particle size of the ceramic powder, the smaller the specific surface area and the easier it becomes to mold, but the lower the activity and the less tight the baking.
【０００５】又、粒子同士が融着したような強い凝集が
あるセラミックス粉末が用いられて焼成された場合に
は、焼結体に表面ピンホールや内部気孔が発生しがちで
あり、このような表面ピンホールや内部気孔が有る焼結
体は構造用セラミックスや電子回路用絶縁セラミックス
等には不適当なものである。この為、このような欠点を
解決する為に、焼成前にセラミックス粉末を長時間かけ
て粉砕して凝集体の破断を行うことが行われているもの
の、充分なものではない。Further, when a ceramic powder having strong agglomeration such that particles are fused to each other is used and fired, surface pinholes and internal pores are apt to occur in the sintered body. A sintered body having surface pinholes and internal pores is unsuitable for structural ceramics, insulating ceramics for electronic circuits, and the like. Therefore, in order to solve such a drawback, it has been attempted to break the agglomerates by crushing the ceramic powder for a long time before firing, but this is not sufficient.
【０００６】このようなことから、構造用セラミックス
や電子回路用絶縁セラミックスの出発原料であるムライ
ト系のセラミックス粉末は凝集がなく、球状であり、一
定範囲の粒度であることが望ましい。そして、このよう
な望ましい物性のセラミックス粉末を得る為の技術が各
種提案されている。例えば、硝酸アルミニウムとオルソ
ケイ酸エチルの混合水溶液を６００℃で噴霧熱分解法に
よりアルミナ−シリカ系粉末を合成し、この合成粉末を
９５０℃で仮焼した後に粉砕し、そしてこれを成形して
１６５０℃で焼成する技術（特開昭６１−２７５６１３
号公報）とか、アルミナゾル及びシリカゾルの混合ゾル
を３００℃程度の温度下で噴霧乾燥し、このようにして
得たセラミックス粉末を成形して１５００℃程度の温度
で焼成する技術（特開昭６１−２３６６４９号公報）が
提案されている。From the above, it is desirable that the mullite-based ceramic powder, which is a starting material for structural ceramics and insulating ceramics for electronic circuits, has no agglomeration, is spherical, and has a particle size within a certain range. Various techniques have been proposed for obtaining a ceramic powder having such desired physical properties. For example, an alumina-silica-based powder is synthesized by spray pyrolysis of a mixed aqueous solution of aluminum nitrate and ethyl orthosilicate at 600 ° C., the synthetic powder is calcined at 950 ° C., then crushed, and then molded at 1650. Technology of firing at ℃ (JP-A-61-275613)
(Japanese Patent Application Laid-Open No. 6-61), or a mixed sol of alumina sol and silica sol is spray-dried at a temperature of about 300 ° C., and the ceramic powder thus obtained is molded and fired at a temperature of about 1500 ° C. No. 236649) has been proposed.
【０００７】[0007]
【発明が解決しようとする課題】ところで、特開昭６１
−２７５６１３号公報で提案されている噴霧熱分解法の
技術では、例えばアルミナ源に硝酸塩等が用いられてい
る為熱分解により水分を含む腐食性の強いガスが大量に
発生して反応容器の耐久性が問題となったり、噴霧によ
って得られた球状粉末は非晶質なものであるため比表面
積が大きく、その後９００℃以上の温度で熱処理して結
晶化処理すると凝集が起き易かったり、得られる球状粉
末内部に閉気孔が形成され易かつたり等の問題点が有
る。By the way, Japanese Unexamined Patent Publication No. Sho 61-61
In the technology of the spray pyrolysis method proposed in Japanese Patent Application Laid-Open No. 275613/1993, for example, nitrate or the like is used as an alumina source, so that a large amount of highly corrosive gas containing water is generated by the pyrolysis and durability of the reaction vessel is increased. Property becomes a problem, and the spherical powder obtained by spraying has a large specific surface area because it is amorphous, and if it is subsequently heat-treated at a temperature of 900 ° C. or higher to be crystallized, agglomeration easily occurs. There is a problem that closed pores are easily formed inside the spherical powder.
【０００８】又、特開昭６１−２３６６４９号公報の技
術にあっても、焼成時に凝集が起きており、この為その
後の粉砕処理が必要である等の問題点がある。そこで、
本発明の目的は、実質上凝集がなく、球状で、適切な粒
子サイズのセラミックス粉末を容易に製造する方法を提
供することにより、構造用セラミックスや電子回路用絶
縁セラミックスなどに有用なムライト系のセラミックス
焼結体を提供することである。Further, even the technique disclosed in Japanese Patent Laid-Open No. 61-236649 has a problem that agglomeration occurs at the time of firing, which necessitates a subsequent pulverization process. Therefore,
An object of the present invention is to provide a method for easily producing a ceramic powder having a substantially spherical shape, a spherical shape, and an appropriate particle size, thereby providing a mullite-based material useful for structural ceramics, insulating ceramics for electronic circuits, and the like. It is to provide a ceramics sintered body.
【０００９】[0009]
【課題を解決する為の手段】アルミナゾルとシリカゾル
との混合ゾルを噴霧加熱することによりムライト粉末を
製造する方法についての研究を鋭意押し進めて行く中
で、この噴霧加熱の技術によれば球状のムライト粉末が
得られることが判ったのみではなく、この加熱温度が高
い条件であれば、すなわち単なる乾燥といった程度を越
えた温度条件下での処理、つまり噴霧焼成が行われる
と、凝集がなく球状で適切な粒子サイズのムライト粉末
が得られることが判って来た。Means for Solving the Problems In the course of intensive research on a method of producing mullite powder by spray heating a mixed sol of alumina sol and silica sol, according to this spray heating technique, spherical mullite is used. Not only was it found that a powder was obtained, but if the heating temperature was high, that is, if the treatment under a temperature condition exceeding the degree of simple drying, that is, spray firing, was performed, it was spherical without aggregation. It has been found that a mullite powder of suitable particle size is obtained.
【００１０】すなわち、特開昭６１−２３６６４９号公
報の技術における噴霧時の温度が低い場合には、球状粉
末が得られるものの、この球状粉末は非晶質なものであ
り、しかも比表面積が大きいものであり、このようなも
のは焼結体を製造するのに好ましくない。しかしなが
ら、この噴霧時の温度を上げて行くと、得られるムライ
ト粉末は比表面積が小さくなり、噴霧条件を最適化する
ことにより充分結晶化（ムライト結晶は約１０００℃以
上で結晶化）したものが得られた。尚、高過ぎる温度で
はムライト結晶子径が大きくなり過ぎ、そしてムライト
結晶子径が大きくなり過ぎると、例えばムライト結晶子
径が２００ｎｍを越えて大きくなり過ぎると焼結時の活
性度が低くなり、焼き締まりが悪くなったことから、噴
霧時の温度は高過ぎない方が好ましいものであった。例
えば、１０００℃〜１７００℃の範囲内での温度下への
噴霧を行うと、凝集がなく、球状で、適切な粒子サイズ
のムライト粉末が得られたのである。That is, when the temperature at the time of spraying in the technique of Japanese Patent Laid-Open No. 61-236649 is low, spherical powder can be obtained, but this spherical powder is amorphous and has a large specific surface area. However, such a material is not preferable for producing a sintered body. However, when the temperature during the spraying is increased, the specific surface area of the obtained mullite powder becomes small, and the mullite powder that is sufficiently crystallized (mullite crystals are crystallized at about 1000 ° C. or higher) by optimizing the spraying conditions Was obtained. Incidentally, if the temperature is too high, the mullite crystallite size becomes too large, and if the mullite crystallite size becomes too large, for example, if the mullite crystallite size becomes too large exceeding 200 nm, the activity during sintering becomes low, It was preferable that the temperature at the time of spraying was not too high because the baking tightness became worse. For example, when spraying was carried out at a temperature in the range of 1000 ° C. to 1700 ° C., mullite powder having a spherical shape and an appropriate particle size without aggregation was obtained.
【００１１】特に、噴霧する反応室に、例えばメタン、
プロパン、ブタン等のガス又は石油系の燃料を燃焼させ
たバーナーの火炎を吹き込み、すなわち火炎が存在して
いる１０００℃〜１７００℃の雰囲気下にアルミナゾル
とシリカゾルとの混合ゾルを噴霧すると、ムライト粒子
同士の融着凝集は殆ど起きないものであった。又、ムラ
イト粉末の焼結特性についての研究を進めて行く中で、
ムライト粉末の粒子サイズは平均粒径が１０μｍ以下が
望ましいことが判り、これについての研究を更に押し進
めて行った結果、アルミナゾルとシリカゾルとの混合ゾ
ルの噴霧時における粒径の大きさにより影響を受けるこ
とが判って来た。例えば、噴霧液滴粒径が最大１５０μ
ｍであるように制御されて噴霧が行われると、平均粒径
が１０μｍ以下の結晶化率の高いムライト粉末の得られ
る傾向が高かったのである。そして、１５０μｍを越え
て大き過ぎる液滴粒径のものが焼成されると、結晶化率
が低下して行く傾向が認められた。In particular, in the atomizing reaction chamber, for example methane,
When a flame of a burner that burns a gas such as propane or butane or a petroleum-based fuel is blown, that is, when a mixed sol of alumina sol and silica sol is sprayed in an atmosphere of 1000 ° C to 1700 ° C in which the flame exists, mullite particles are obtained. Almost no fusion and cohesion between them occurred. Also, while proceeding with the research on the sintering characteristics of mullite powder,
It was found that the average particle size of the mullite powder is preferably 10 μm or less. As a result of further research on this, it was affected by the particle size of the mixed sol of alumina sol and silica sol. I knew that. For example, the maximum atomized droplet size is 150μ.
When the spraying was carried out while being controlled to be m, the mullite powder having an average particle size of 10 μm or less and a high crystallization rate tended to be obtained. When a droplet having a particle diameter exceeding 150 μm and having a too large particle size was fired, the crystallization rate tended to decrease.
【００１２】又、噴霧液滴粒径が１５０μｍ以下のもの
を効率良く製造するには、分散液の固形分濃度が２５重
量％以下であることが好ましかった。すなわち、２５重
量％を越えると、粒子が粗大化し易く、球状から大きく
歪む傾向があったからである。尚、分散液の固形分濃度
が３重量％以下の少なすぎる場合には、噴霧焼成して得
られる粉末粒子の形状が大きな凹みができるなど大きく
歪む傾向に有り、球形から遠ざかるものとなることか
ら、３重量％以上であることが、望ましくは５重量％以
上であることが好ましい。Further, in order to efficiently produce a sprayed droplet having a particle diameter of 150 μm or less, it is preferable that the solid content concentration of the dispersion liquid is 25% by weight or less. That is, if it exceeds 25% by weight, the particles tend to become coarse and tend to be largely distorted from spherical shapes. If the solid content concentration of the dispersion liquid is too low, that is, 3% by weight or less, the shape of the powder particles obtained by spray firing tends to be greatly distorted such as large dents, and the particles become far from spherical. It is preferably 3% by weight or more, and more preferably 5% by weight or more.
【００１３】又、噴霧される分散液のｐＨが２〜４の場
合には、分散液の粘性も安定し、噴霧状態も良好となる
為、短時間でも結晶化率の高いムライト粉末が得られ
た。本発明はこのような知見を基にして達成されたもの
であり、前記本発明の目的は、アルミナゾルとシリカゾ
ルとをＡｌ2 Ｏ3 ／ＳｉＯ2 （重量比）が４０／６０〜
８０／２０の割合で混合し、ｐＨが２〜４、固形分濃度
が３〜２５重量％となるように調整した分散液を、火炎
温度が１０００℃〜１７００℃の雰囲気中に分散液の噴
霧液滴粒径が１５０μｍ以下の粒径で噴霧、焼成するこ
とを特徴とするセラミックス球状粉末の製造方法によっ
て成し遂げられる。Further, when the pH of the sprayed dispersion is 2 to 4, the viscosity of the dispersion is stable and the sprayed state is good, so that mullite powder having a high crystallization rate can be obtained even in a short time. It was The present invention has been achieved based on such knowledge, and the object of the present invention is to provide alumina sol and silica sol with Al 2 O 3 / SiO 2 (weight ratio) of 40/60 to.
The dispersion liquid, which was mixed at a ratio of 80/20 and adjusted to have a pH of 2 to 4 and a solid content concentration of 3 to 25% by weight, was sprayed in an atmosphere having a flame temperature of 1000 ° C to 1700 ° C. This can be achieved by a method for producing a ceramic spherical powder characterized by spraying and firing with a droplet size of 150 μm or less.
【００１４】本発明において用いられるアルミナゾルの
アルミナ源としては、非晶質アルミナ若しくはγ−アル
ミナ、δ−アルミナ、θ−アルミナ、κ−アルミナ等の
非水和アルミナ、又はギブサイト、バイヤライト、ノー
トストランダイト、ボーキサイト、ベーマイト、ダイヤ
スポア、トーダイト等の水和アルミナの何れか一種又は
二種以上を組み合わせたものが有り、そしてこのような
アルミナ源が水または不活性溶媒に分散された液が本発
明のセラミックス粉末の製造には用いられる。特に、好
ましくは、γ−アルミナやベーマイトの水分散液を８０
℃以上に加熱しながら、硝酸、塩酸等の無機酸や酢酸、
ギ酸等の有機酸を適量加えて、解膠することによって得
られたアルミナゾルが用いられる。As the alumina source of the alumina sol used in the present invention, amorphous alumina or non-hydrated alumina such as γ-alumina, δ-alumina, θ-alumina and κ-alumina, or gibbsite, bayerite, and notebook stran. Dite, bauxite, boehmite, diamond spore, there is a combination of any two or more hydrated alumina such as todite, and a liquid in which such an alumina source is dispersed in water or an inert solvent is of the present invention. Used in the manufacture of ceramic powder. Particularly preferably, an aqueous dispersion of γ-alumina or boehmite is added to 80
Inorganic acid such as nitric acid and hydrochloric acid, acetic acid,
An alumina sol obtained by adding an appropriate amount of organic acid such as formic acid and peptizing is used.
【００１５】シリカゾルのシリカ源としては、シリカ微
粒子、例えば湿式法で製造されるホワイトカーボンや乾
式法のヒュームドシリカを水中に分散させたコロイド水
溶液が用いられる。そして、これらアルミナゾル又はシ
リカゾル各々単独のゾルを用いて噴霧焼成することによ
り本発明になるセラミックス粉末が得られる訳である
が、セラミックス粉末のＡｌ2 Ｏ3 ／ＳｉＯ2 （重量
比）が４０／６０ないし８０／２０の範囲内のものとな
るようにアルミナゾルとシリカゾルとを均質に混合し、
このような特定の配合割合の混合ゾルを、例えば１１０
０℃ないし１６００℃の火炎条件下において噴霧焼成
し、平均粒径が１０μｍ以下のセラミックス粉末を得、
これを用いて通常の手段により成形、焼成すると、構造
用セラミックスや電子回路用絶縁セラミックス等に好適
な焼結体が得られた。As the silica source of the silica sol, fine particles of silica, for example, white carbon produced by a wet method or a colloidal aqueous solution in which fumed silica of a dry method is dispersed in water is used. Then, the ceramic powder according to the present invention can be obtained by spraying and firing each of these sol of alumina sol or silica sol alone, and the Al 2 O 3 / SiO 2 (weight ratio) of the ceramic powder is 40/60. To homogeneously mix the alumina sol and silica sol so that they fall within the range of 80/20.
A mixed sol having such a specific mixing ratio is, for example, 110
Spray firing under a flame condition of 0 ° C. to 1600 ° C. to obtain a ceramic powder having an average particle size of 10 μm or less,
When this was used and molded and fired by ordinary means, a sintered body suitable for structural ceramics, insulating ceramics for electronic circuits and the like was obtained.
【００１６】すなわち、本発明によれば、構造用セラミ
ックスや電子回路用絶縁セラミックスを製造するのに適
したムライト系の良質なセラミックス粉末が簡便に製造
できたのである。特に、この際、従来のような腐食性の
有るガスは発生せず、又、仮焼工程は要らず、さらには
粉砕工程が無くても済み、短時間でセラミックス粉末が
得られ、製造能率が高く、しかも製造が一段と簡便であ
り、さらには得られる粉末は球状で、成形性が良く、粒
子内部に閉気孔がなく、凝集は実質上なく、良質で均質
な焼結体が容易に製造できるのである。That is, according to the present invention, a high-quality mullite-based ceramic powder suitable for producing structural ceramics and insulating ceramics for electronic circuits can be easily produced. In particular, at this time, the conventional corrosive gas is not generated, the calcination step is not required, and further, the pulverization step is not necessary, the ceramic powder can be obtained in a short time, and the manufacturing efficiency is improved. It is high, and the production is much simpler. Furthermore, the obtained powder is spherical, has good moldability, has no closed pores inside the particles, and has substantially no agglomeration, so that a good quality and homogeneous sintered body can be easily produced. Of.
【００１７】[0017]
〔原料ゾルの作成〕原料となるアルミナゾルは、べーマ
イトを解膠剤として少量の酸を加えたイオン交換水に投
入し、加熱、攪拌しながら分散して作成した。シリカゾ
ルは、ホワイトカーボンを解膠剤として少量の酸を加え
たイオン交換水に攪拌しながら分散して作成した。[Preparation of raw material sol] Alumina sol as a raw material was prepared by adding boehmite as a peptizing agent to ion-exchanged water to which a small amount of acid was added, and dispersing the mixture while heating and stirring. The silica sol was prepared by dispersing it in ion-exchanged water containing white carbon as a deflocculant with a small amount of acid added thereto while stirring.
【００１８】アルミナ−シリカ系の粉末を製造する場合
は、上記のようにしてアルミナゾル及びシリカゾルを別
々に作成した後、下記の表１に示すような所定の割合に
混合し、これを均質になるよう充分に攪拌してｐＨ及び
固形分濃度が下記の表１に示されるような原料ゾルとし
た。 〔セラミックス粉末の作成〕反応室にプロパンを燃焼さ
せた火炎を供給し、この反応室内を１０００℃〜１７０
０℃の温度に加熱し、充分に温度が安定した条件下にお
いて前記の原料ゾルを下記の表１に示すような液滴粒径
にノズルで噴霧し、焼成してセラミックス粉末を得た。In the case of producing the alumina-silica powder, the alumina sol and the silica sol are separately prepared as described above, and then mixed at a predetermined ratio as shown in Table 1 below to homogenize the mixture. Thus, the raw material sol whose pH and solid content concentration are shown in Table 1 below was sufficiently stirred. [Preparation of ceramic powder] A flame in which propane is burned is supplied to the reaction chamber, and the temperature in the reaction chamber is 1000 ° C to 170 ° C.
The raw material sol was heated to a temperature of 0 ° C. and sprayed with a nozzle into droplet diameters shown in Table 1 below under conditions where the temperature was sufficiently stable, and fired to obtain a ceramic powder.
【００１９】[0019]
【特性】上記のようにして得られたセラミックス粉末に
ついての物性を調べたので、その結果を下記の表１，２
に示す。 表 １ 分散液 固形分 Ａｌ2 Ｏ3 ／ＳｉＯ2 噴霧液滴粒径 噴霧温度 ｐＨ ％ （重量比） （最大） （℃） 実施例１ ２．７ １０ ４５／６５ １２０μ １３００ 実施例２ ２．７ １０ ７２／２８ １２０μ １４００ 実施例３ ３．１ ２０ ７２／２８ ９０μ １４００ 実施例４ ２．７ １０ ７２／２８ １２０μ １６００ 実施例５ ３．１ ２０ ７８／２２ ９０μ １５００ 比較例１ ２．７ １０ ４５／６５ １２０μ ５００ 比較例２ ４．２ １０ ４５／６５ １２０μ ５００ 比較例３ ２．７ １０ ４５／６５ １２０μ ８００ 比較例４ ４．２ １０ ４５／６５ １２０μ １４００ 比較例５ ３．１ ３０ ４５／６５ １８０μ ８００ 比較例６ ２．７ １０ １００／０ １２０μ １４００ 比較例７ ３．１ ２０ ０／１００ ９０μ １１００ 比較例８ ２．７ ２ ４５／６５ １２０μ １３００ 表 ２ 形状 平均粒径 内部気孔 凝集 結晶化率 結晶子径 実施例１ 球状 ７．４μｍ 無し 無し ７０％ ２０ｎｍ 実施例２ 球状 ６．９μｍ 無し 無し ８０％ ２５ｎｍ 実施例３ 球状 ９．１μｍ 無し 無し ８０％ ２５ｎｍ 実施例４ 球状 ６．７μｍ 無し 無し ９０％以上 １２０ｎｍ 実施例５ 球状 ８．８μｍ 無し 無し ９０％以上 ８０ｎｍ 比較例１ 球状 ４０μｍ 無し 無し ０ − 比較例２ 球状 ５５μｍ 無し 無し ０ − 比較例３ 球状 ３５μｍ 無し 無し ０ − 比較例４ 球状 １８μｍ 無し 無し ６０％ − 比較例５ 球状 ７０μｍ 無し 無し ０ − 比較例６ 球状 ６．３μｍ 無し 無し − − 比較例７ 球状 ９．３μｍ 無し 無し − − 比較例８ 凹凸の形成が大きく、非球状な粉末が３５％もの割合で発生 これによれば、本発明になるものでは、実質上凝集がな
く、粒子内部に気孔がなく、球状で、適切な粒子サイズ
のセラミックス粉末が簡単に製造出来ており、そしてこ
れら各例で得たセラミックス粉末を成形し、焼成した
所、本実施例のものでは表面ピンホールや内部気孔が無
い、例えば構造用セラミックスや電子回路用絶縁セラミ
ックスなどに有用な優れた特性のセラミックス焼結体の
得られていることが判った。[Characteristics] The physical properties of the ceramic powder obtained as described above were examined. The results are shown in Tables 1 and 2 below.
Shown in. Table 1 Dispersion Solid content Al 2 O 3 / SiO 2 spray droplet particle size Spray temperature pH% (weight ratio) (maximum) (° C) Example 1 2.7 10 45/65 120μ 1300 Example 2 2.7 10 72/28 120μ 1400 Example 3 3.1 20 72/28 90μ 1400 Example 4 2.7 10 72/28 120μ 1600 Example 5 3.1 20 78/22 90μ 1500 Comparative Example 1 2.7 10 45 / 65 120μ 500 Comparative Example 2 4.2 10 45/65 120μ 500 Comparative Example 3 2.7 10 45/65 120μ 800 Comparative Example 4 4.2 10 45/65 120μ 1400 Comparative Example 5 3.1 30 45/65 180μ 800 Comparative Example 6 2.7 10 100/0 120μ 1400 Comparative Example 7 3.1 20 0/100 90μ 1100 Comparative Example 8 2.7 2 4 5/65 120 μ 1300 Table 2 Shape Average particle size Internal pore Aggregation Crystallization rate Crystallite size Example 1 Spherical 7.4 μm None None 70% 20 nm Example 2 Spherical 6.9 μm None None 80% 25 nm Example 3 Spherical 9. 1 μm None None 80% 25 nm Example 4 Spherical 6.7 μm None None 90% or more 120 nm Example 5 Spherical 8.8 μm None None 90% or more 80 nm Comparative Example 1 Spherical 40 μm None None 0-Comparative Example 2 Spherical 55 μm None None-0- Comparative Example 3 Spherical 35 μm None None 0 − Comparative Example 4 Spherical 18 μm None None 60% − Comparative Example 5 Spherical 70 μm None None 0 − Comparative Example 6 Spherical 6.3 μm None None − − Comparative Example 7 Spherical 9.3 μm None None − − Comparative Example 8 Concavo-convex formation was large, and non-spherical powder was generated at a ratio of 35%. In this case, there is virtually no agglomeration, there are no pores inside the particles, and a spherical, suitable particle size ceramic powder can be easily produced, and the ceramic powder obtained in each of these examples is molded and fired. As a result, it was found that in the present example, a ceramic sintered body having no surface pinholes or internal pores and having excellent characteristics useful for, for example, structural ceramics or insulating ceramics for electronic circuits was obtained.
【００２０】尚、比較例のものでは、本実施例から得ら
れたようなセラミックス焼結体は得られなかった。In the comparative example, the ceramic sintered body obtained in this example could not be obtained.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 熊木 孝夫 埼玉県熊谷市大字三ケ尻5310番地 秩父セ メント株式会社フアインセラミツクス本部 内 (72)発明者 根本 文夫 埼玉県熊谷市大字三ケ尻5310番地 秩父セ メント株式会社フアインセラミツクス本部 内 (72)発明者 片山 恵一 埼玉県熊谷市大字三ケ尻5310番地 秩父セ メント株式会社フアインセラミツクス本部 内 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takao Kumaki 5310, Mikajiri, Kumagaya, Saitama Prefecture Chichibu Cement, Huain Ceramics Division, Inc. (72) Fumio Nemoto 5353, Mikajiri, Kumagaya, Saitama Prefecture Chichibu cement Huain Ceramics Headquarters (72) Inventor Keiichi Katayama 5310 Mikajiri, Kumagaya-shi, Saitama Chichibu Sentence Huain Ceramics Headquarters
Claims (1)
3 ／ＳｉＯ2 （重量比）が４０／６０〜８０／２０の割
合で混合し、ｐＨが２〜４、固形分濃度が３〜２５重量
％となるように調整した分散液を、火炎温度が１０００
℃〜１７００℃の雰囲気中に分散液の噴霧液滴粒径が１
５０μｍ以下の粒径で噴霧、焼成することを特徴とする
セラミックス球状粉末の製造方法。1. Alumina sol and silica sol are mixed with Al 2 O.
3 / SiO 2 (weight ratio) was mixed at a ratio of 40/60 to 80/20, and the dispersion liquid adjusted to have a pH of 2 to 4 and a solid content concentration of 3 to 25% by weight had a flame temperature of 1000
The particle size of sprayed droplets of the dispersion liquid is 1 in an atmosphere of ℃ to 1700 ℃.
A method for producing a spherical ceramic powder, which comprises spraying and firing with a particle size of 50 μm or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3120113A JPH05105419A (en) | 1991-05-24 | 1991-05-24 | Production of spherical ceramic powder |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3120113A JPH05105419A (en) | 1991-05-24 | 1991-05-24 | Production of spherical ceramic powder |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05105419A true JPH05105419A (en) | 1993-04-27 |
Family
ID=14778268
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3120113A Pending JPH05105419A (en) | 1991-05-24 | 1991-05-24 | Production of spherical ceramic powder |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05105419A (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008542178A (en) * | 2005-06-02 | 2008-11-27 | アンスティテュ フランセ デュ ペトロール | Mesostructured material with high aluminum content |
| CN102503387A (en) * | 2011-09-27 | 2012-06-20 | 中国地质大学（武汉） | Method for preparing high-purity super-fine mullite powder |
| JP2012123196A (en) * | 2010-12-08 | 2012-06-28 | Canon Inc | Toner |
| CN102963896A (en) * | 2012-11-28 | 2013-03-13 | 华北水利水电学院 | Preparation method of mullite precursor and nano mullite |
| JP2013180905A (en) * | 2012-02-29 | 2013-09-12 | Kao Corp | Production method of spherical ceramic particle |
| JP2014525389A (en) * | 2011-09-09 | 2014-09-29 | ユーオーピー エルエルシー | Process for forming zeolite from homogeneous amorphous silica alumina |
-
1991
- 1991-05-24 JP JP3120113A patent/JPH05105419A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008542178A (en) * | 2005-06-02 | 2008-11-27 | アンスティテュ フランセ デュ ペトロール | Mesostructured material with high aluminum content |
| JP2012123196A (en) * | 2010-12-08 | 2012-06-28 | Canon Inc | Toner |
| JP2014525389A (en) * | 2011-09-09 | 2014-09-29 | ユーオーピー エルエルシー | Process for forming zeolite from homogeneous amorphous silica alumina |
| CN102503387A (en) * | 2011-09-27 | 2012-06-20 | 中国地质大学（武汉） | Method for preparing high-purity super-fine mullite powder |
| JP2013180905A (en) * | 2012-02-29 | 2013-09-12 | Kao Corp | Production method of spherical ceramic particle |
| CN102963896A (en) * | 2012-11-28 | 2013-03-13 | 华北水利水电学院 | Preparation method of mullite precursor and nano mullite |
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