JPH04170306A - Particle concentration control in vapor phase production of superfine particle - Google Patents
Particle concentration control in vapor phase production of superfine particleInfo
- Publication number
- JPH04170306A JPH04170306A JP29715390A JP29715390A JPH04170306A JP H04170306 A JPH04170306 A JP H04170306A JP 29715390 A JP29715390 A JP 29715390A JP 29715390 A JP29715390 A JP 29715390A JP H04170306 A JPH04170306 A JP H04170306A
- Authority
- JP
- Japan
- Prior art keywords
- particles
- alkoxide
- sent
- particle
- reactor
- 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
- 239000002245 particle Substances 0.000 title claims abstract description 94
- 238000004519 manufacturing process Methods 0.000 title claims description 7
- 239000012808 vapor phase Substances 0.000 title 1
- 239000007787 solid Substances 0.000 claims abstract description 18
- 239000002994 raw material Substances 0.000 claims abstract description 16
- 239000010419 fine particle Substances 0.000 claims abstract description 5
- 239000011882 ultra-fine particle Substances 0.000 claims description 5
- 150000004703 alkoxides Chemical class 0.000 abstract description 23
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 abstract description 21
- 238000006243 chemical reaction Methods 0.000 abstract description 17
- 238000009826 distribution Methods 0.000 abstract description 16
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 abstract description 14
- 239000007789 gas Substances 0.000 abstract description 14
- 239000007788 liquid Substances 0.000 abstract description 8
- 238000009833 condensation Methods 0.000 abstract description 6
- 230000005494 condensation Effects 0.000 abstract description 6
- 239000000443 aerosol Substances 0.000 abstract description 4
- 238000006460 hydrolysis reaction Methods 0.000 abstract description 4
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 4
- 239000008246 gaseous mixture Substances 0.000 abstract 1
- 238000000034 method Methods 0.000 description 10
- 239000000843 powder Substances 0.000 description 9
- 229910001873 dinitrogen Inorganic materials 0.000 description 8
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 7
- 239000000919 ceramic Substances 0.000 description 6
- 239000000463 material Substances 0.000 description 5
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 4
- 230000002776 aggregation Effects 0.000 description 4
- JMXKSZRRTHPKDL-UHFFFAOYSA-N titanium ethoxide Chemical compound [Ti+4].CC[O-].CC[O-].CC[O-].CC[O-] JMXKSZRRTHPKDL-UHFFFAOYSA-N 0.000 description 4
- 238000004220 aggregation Methods 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- WOZZOSDBXABUFO-UHFFFAOYSA-N tri(butan-2-yloxy)alumane Chemical compound [Al+3].CCC(C)[O-].CCC(C)[O-].CCC(C)[O-] WOZZOSDBXABUFO-UHFFFAOYSA-N 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 239000003085 diluting agent Substances 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000010304 firing Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 229910052751 metal Inorganic materials 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 230000003287 optical effect Effects 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 238000005245 sintering Methods 0.000 description 2
- 239000012798 spherical particle Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 1
- 238000002441 X-ray diffraction Methods 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- SMZOGRDCAXLAAR-UHFFFAOYSA-N aluminium isopropoxide Chemical compound [Al+3].CC(C)[O-].CC(C)[O-].CC(C)[O-] SMZOGRDCAXLAAR-UHFFFAOYSA-N 0.000 description 1
- JPUHCPXFQIXLMW-UHFFFAOYSA-N aluminium triethoxide Chemical compound CCO[Al](OCC)OCC JPUHCPXFQIXLMW-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910002113 barium titanate Inorganic materials 0.000 description 1
- 230000008033 biological extinction Effects 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 239000011246 composite particle Substances 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 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 1
- 238000004993 emission spectroscopy Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 239000003701 inert diluent Substances 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 229910052863 mullite Inorganic materials 0.000 description 1
- OGHBATFHNDZKSO-UHFFFAOYSA-N propan-2-olate Chemical compound CC(C)[O-] OGHBATFHNDZKSO-UHFFFAOYSA-N 0.000 description 1
- 239000010936 titanium Substances 0.000 description 1
- 229910052719 titanium Inorganic materials 0.000 description 1
- 150000003609 titanium compounds Chemical class 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
新材料開発の分野で、超微粉の純度・粒子形状・粒度分
布等を制御することにより、これを焼結または分散して
得られる材料に、多様な新しい機能を付与することが期
待されている。この中で、サブミクロンサイズで粒度分
布が狭く、かつ球状粒子のセラミック微粉は、焼結原料
粉や充填材、研摩材、標準粒子等として用途の拡大が期
待される。[Detailed description of the invention] [Field of industrial application] In the field of new material development, by controlling the purity, particle shape, particle size distribution, etc. of ultrafine powder, it is possible to create materials obtained by sintering or dispersing it. , is expected to add a variety of new functions. Among these, ceramic fine powder with submicron size, narrow particle size distribution, and spherical particles is expected to find expanded applications as sintering raw material powder, filler, abrasive, standard particles, etc.
本発明はこの粒径の整った球形超微粒子の連続製造方法
に関するものである。The present invention relates to a method for continuously producing ultrafine spherical particles of uniform particle size.
従来、セラミック微粉の多くは液滴を経由しない直接Ｃ
ＶＤによって製造されていた。液滴を経由する製造方法
も利用されているが、その場合、一般的に種粒子は用い
られていなかった。ところで、チタン（ＩＶ）エトキシ
ドなどの４価の液状チタン化合物の液滴を加水分解して
球形の二酸化チタン粒子を製造する際に、ＡｇＣＩ！を
種粒子に用いる方法が知られている。（Ｍ、Ｖｉｓｃａ
ｅｔ ａｌ、、 Ｊｏｕｒｎａｌｏｆ Ｃｏ１１ｏｉ
ｄ ａｎｄ Ｉｎｔｅｒｆａｃｅ ５ｃｉｅｎｃｅ、
ｖｏｌ、 ６８＋Ｎｏ、２． Ｐ３０Ｂ〜３１９．１９
７９）。また、アルミニウム第二ブトキシド蒸気を凝縮
させて液滴を形成し、続いて液滴と水蒸気との化学反応
を乱流系で行なわせることによるサブミクロン単位のア
ルミナ粉を製造する方法も知られている（Ｔ、Ｔ、 Ｋ
ａｄａｓら、Ｐｏｗｄｅｒ Ｔｅｃｈｎｏｌｏｇｙ、５
０巻、４７〜５３頁、１９８７年）。Conventionally, most of the ceramic fine powders were produced by direct C without going through droplets.
Manufactured by VD. Droplet-based production methods have also been used, but generally without seed particles. By the way, when producing spherical titanium dioxide particles by hydrolyzing droplets of a tetravalent liquid titanium compound such as titanium (IV) ethoxide, AgCI! A method is known in which the particle is used as a seed particle. (M, Visca
et al,, Journal of Co11oi
d and Interface 5science,
vol, 68+No, 2. P30B~319.19
79). It is also known to produce submicron-sized alumina powder by condensing aluminum sec-butoxide vapor to form droplets, followed by a chemical reaction between the droplets and water vapor in a turbulent flow system. There is (T, T, K
adas et al., Powder Technology, 5
0, pp. 47-53, 1987).
二のなかでは乱流系と層流系が検討され、さらに凝縮前
に種粒子を加えることによって液滴の壁面での凝縮を減
少させるとともに粒度分布もかなり狭まることが報告さ
れている。In 2, turbulent flow systems and laminar flow systems were investigated, and it was reported that adding seed particles before condensation reduces condensation on the droplet walls and considerably narrows the particle size distribution.
〔発明が解決しようとする課題］
液滴を経由しない直接ＣＶＤは粒度分布が広いばかりで
なく粒形も不揃いであった。液滴を経由する方法の場合
には球形微粒子が得られるが粒度分布が極めて広く、ま
た生成効率にも問題があった。ＡｇＣｆ等の種粒子を用
いる方法は粒度分布の狭い球形微粒子が得られるが純度
が低下するという問題があった。Ｋｏｄａｓらは同一物
質を種粒子として用いる方法を開示しているが粒度分布
が広いという問題があった。[Problems to be Solved by the Invention] Direct CVD without using droplets has not only a wide particle size distribution but also irregular particle shapes. In the case of the method using droplets, spherical fine particles can be obtained, but the particle size distribution is extremely wide, and there are also problems in production efficiency. Although the method using seed particles such as AgCf produces spherical fine particles with a narrow particle size distribution, there is a problem in that the purity decreases. Kodas et al. disclose a method using the same material as seed particles, but there is a problem that the particle size distribution is wide.
本発明は上記の課題を解決して、粒度分布が極めて狭く
、かつ高純度のセラミック微粉を製造する手段を提供す
ることを目的としている。An object of the present invention is to solve the above-mentioned problems and provide a means for producing ceramic fine powder having an extremely narrow particle size distribution and high purity.
本発明は上記目的を達成した球形超微粒子の気相製造法
を提供するものであり、原料の一方を微細液滴群とし、
他方をガス状態としたうえで両者を反応させて固体微粒
子群を得る液滴ＣＶＤにおいて、微細液滴群又は固体微
粒子群を透過する光量を制振量とし、液滴の核となる種
粒子を生成する反応器に送入する原料濃度を操作量とし
て生成する種粒子及び前記固体粒子の濃度を制御するこ
とを特徴としている。The present invention provides a method for producing spherical ultrafine particles in a gas phase that achieves the above object, in which one of the raw materials is a group of fine droplets,
In droplet CVD in which the other is in a gas state and the two are reacted to obtain a group of solid particles, the amount of light that passes through the group of fine droplets or the group of solid particles is used as the vibration damping amount, and the seed particle that becomes the nucleus of the droplet is The method is characterized in that the concentration of the seed particles to be generated and the solid particles are controlled by using the concentration of the raw material fed into the reactor to be generated as a manipulated variable.
球形超微粒子はセラミック等であり、セラミックの例と
してはＡ １ ｚ Ｏ：Ｉ、 Ｔ ｉ Ｏ２，５ｉＯｚ
、ＺｒＯ２等の酸化物、ＢａＴｉＯ３等の複合酸化物、
ムライト（３Ａｆ２０ｆｆ・２ＳｉＯ□）等の複合粒子
等を挙げることができる。平均粒径は０．０５〜５ｎ程
度、好ましくは０．０５〜０．３ｎ程度であり、分布は
幾何標準偏差で１．２〜１．４、特に１．２５〜１．３
５程度である。The spherical ultrafine particles are ceramics, etc. Examples of ceramics are A 1 z O:I, T i O2,5iOz
, oxides such as ZrO2, complex oxides such as BaTiO3,
Examples include composite particles such as mullite (3Af20ff·2SiO□). The average particle size is about 0.05 to 5n, preferably about 0.05 to 0.3n, and the distribution has a geometric standard deviation of 1.2 to 1.4, especially 1.25 to 1.3.
It is about 5.
これらはアルコキシドと水蒸気の反応によって生成させ
ることができる。アルコキシドと水蒸気の反応を例に説
明すると、アルコキシドが微細液滴群を形成する。従っ
て、このアルコキシドは反応時に液状のものであり、例
えばアルミナを製造する場合にはアルミニウムエトキシ
ド、アルミニウムイソプロポキシド、アルミニウムブト
キシド等を利用することができ、チタニアの場合にはチ
タン（ＩＶ）エトキシド、チタン（Ｉいイソプロポキシ
ド等を利用することができる。These can be produced by the reaction of alkoxides and water vapor. Taking the reaction between an alkoxide and water vapor as an example, the alkoxide forms a group of fine droplets. Therefore, this alkoxide is liquid during the reaction, and for example, when producing alumina, aluminum ethoxide, aluminum isopropoxide, aluminum butoxide, etc. can be used, and in the case of titania, titanium (IV) ethoxide can be used. , titanium (I), isopropoxide, etc. can be used.
他方のガス状態とされる原料はアルコキシドと水蒸気の
反応の場合には水蒸気である。The other gaseous raw material is water vapor in the case of a reaction between an alkoxide and water vapor.
液滴を形成させる種粒子は目的物であるセラミックと同
−物質又は乾燥もしくは焼成等によって同一物質となり
うるちのが好ましい。乾燥もしくは焼成によって同一物
質となりうるものとは、例えば水酸化物等である。The seed particles for forming droplets are preferably the same material as the target ceramic, or can be made into the same material by drying, firing, etc. Examples of substances that can be converted into the same substance by drying or firing include hydroxides.
アルコキシドと水蒸気の反応は５０〜１３０°Ｃ程度で
行なわせればよく、圧力は加圧、減圧、常圧のいずれで
あってもよく、例えば７８０〜８５０Ｔｏｒｒ程度でよ
い。アルコキシドと水蒸気は並流で接触させてもよ（、
クロスフローで接触させてもよい。アルコキシドと水蒸
気の混合割合は水蒸気を過剰にするのがよく、アルコキ
シドとの反応に必要な理論量の３〜５倍程度が適当であ
る。適した濃度として反応を制御するために反応に不活
性の希釈ガスを用いることが好ましい。この希釈ガスは
搬送ガスとしても機能するものであり窒素ガス、アルゴ
ンガス、ヘリウムガス等を使用できるが、窒素ガスが安
価で入手が容易な点で好ましい。希釈倍率はモル比でア
ルコキシ−ドは５００〜２０００倍程度、水蒸気は５〜
３０倍程度が好ましい。The reaction between the alkoxide and water vapor may be carried out at about 50 to 130°C, and the pressure may be increased, reduced, or normal pressure, for example, about 780 to 850 Torr. The alkoxide and water vapor may be brought into contact in parallel flow (
Contact may be made through cross flow. The mixing ratio of the alkoxide and water vapor is preferably such that the amount of water vapor is in excess, and is suitably about 3 to 5 times the theoretical amount required for reaction with the alkoxide. It is preferred to use an inert diluent gas in the reaction to control the reaction at a suitable concentration. This diluent gas also functions as a carrier gas, and nitrogen gas, argon gas, helium gas, etc. can be used, but nitrogen gas is preferred because it is inexpensive and easily available. The dilution ratio is about 500 to 2000 times for alkoxide and 5 to 2000 times for water vapor in terms of molar ratio.
About 30 times is preferable.
本発明はこのような方法において、微細液滴群又は固体
微粒子群を透過する光量を制御量とし、反応器に送入す
る原料濃度を操作量として生成する前記固体粒子の濃度
を制御するところに特徴がある。In such a method, the present invention is directed to controlling the concentration of the solid particles produced by using the amount of light transmitted through the fine droplets or solid particles as the control amount and using the concentration of the raw material fed into the reactor as the manipulated variable. It has characteristics.
微細液滴群又は固体微粒子群を透過する光量はこれらの
粒子群の流路に光を照射し、透過光量を測定することに
よって求めることができる。測定機器は通常のものでよ
く、光源部、光を流路を通過させる窓部、受光部及び検
出部があればよい。The amount of light transmitted through a group of fine droplets or a group of solid particles can be determined by irradiating light into the flow path of these particle groups and measuring the amount of transmitted light. The measuring device may be a normal one, and it is sufficient as long as it has a light source section, a window section through which light passes through a flow path, a light receiving section, and a detecting section.
測定は粒子群の流れ全体について行なってもよく、ある
いは流れの一部を分岐させてその分流について行なって
もよい。波長は特に限定されるものでなく、測定機器等
に応じて適宜選択すればよい。The measurement may be performed on the entire flow of the particle group, or a part of the flow may be branched and the measurement may be performed on the branched flow. The wavelength is not particularly limited, and may be appropriately selected depending on the measuring equipment and the like.
受光部は粒子群を間において光源部と反対側に設けても
よく、あるいは光源部と適当な角度に設けて粒子による
散乱光を測定してもよい。受光部には光電管あるいは光
電子増倍管等を設けて受光した光を電気信号に変え、検
出部でこの電気信号を増幅して定量し、結果をメーター
に表示しあるいはレコーダで記録する。The light receiving section may be provided on the opposite side of the light source section with the particle group in between, or may be provided at an appropriate angle to the light source section to measure the light scattered by the particles. The light receiving section is equipped with a phototube or a photomultiplier tube to convert the received light into an electrical signal, and the detecting section amplifies and quantifies this electrical signal, and the results are displayed on a meter or recorded on a recorder.
こうして測定された透過光量を制御量として反応器に送
入される原料濃度を操作する。この操作は原料に加える
希釈ガスの混合割合を変えることによって行なう、原料
濃度の°操作は微細液滴群を形成する原料及・びガス状
態で反応させる原料の両方に対して行なってもよいが、
その一方に対して行なってもよい。アルコキシド−水蒸
気反応の場合には一般に水蒸気が過剰に加えられるので
アルコキシドの送入量を操作すればよい。The concentration of the raw material fed into the reactor is controlled using the amount of transmitted light thus measured as a control variable. This operation is performed by changing the mixing ratio of the diluent gas added to the raw material. The manipulation of the raw material concentration may be performed for both the raw material forming fine droplet groups and the raw material reacting in a gas state. ,
You may perform this on one of them. In the case of an alkoxide-steam reaction, since steam is generally added in excess, the amount of alkoxide fed may be controlled.
得られた超微粒子はサイクロン、フィルター、静電捕集
等で捕集して乾燥し、必要により焼成する。The obtained ultrafine particles are collected using a cyclone, a filter, electrostatic collection, etc., dried, and, if necessary, calcined.
液滴又は生成粒子濃度が高すぎると粒子の衝突、凝集が
起こり、粒子分布の均一性が損なわれる。If the concentration of droplets or generated particles is too high, particle collisions and aggregation occur, impairing the uniformity of particle distribution.
一方、液滴又は生成粒子濃度が低くなると生産性が低下
する。ＣＶＤプロセスは反応が複雑で液滴あるいは生成
粒子濃度を正確に予想することは困難である。本発明に
おいては液滴凝縮部出口から固体微粒子群が捕集される
までの流路に光を照射して透過光量を測定し、その結果
を原料流れにフィードバックすることによって液滴及び
生成粒子の濃度を調節して粒子間衝突による凝集を防止
しつつ生産効率を維持している。On the other hand, when the concentration of droplets or generated particles decreases, productivity decreases. The CVD process involves complex reactions and it is difficult to accurately predict the concentration of droplets or generated particles. In the present invention, the flow path from the exit of the droplet condensing section to the collection of solid fine particles is irradiated with light, the amount of transmitted light is measured, and the results are fed back to the raw material flow, thereby reducing droplets and generated particles. By adjusting the concentration, production efficiency is maintained while preventing agglomeration due to collisions between particles.
粒子衝突頻度は、下記関係式で概算できる。The particle collision frequency can be roughly estimated using the following relational expression.
ｆ、Ｎは空間体積当りの衝突頻度と個数濃度。f and N are the collision frequency and number concentration per space volume.
ｍ、ｄｐは粒子の質量と粒径、Ｒはボルツマン定数であ
る。m and dp are the mass and particle size of the particles, and R is Boltzmann's constant.
０．３μの球形アルミナ粒子の場合、各粒子が単位時間
に衝突する頻度（ｆ／Ｎ）は下記になる。In the case of 0.3μ spherical alumina particles, the frequency (f/N) at which each particle collides per unit time is as follows.
粒子濃度（個／ｃｉｊ） 衝突頻度（回／５ｅｃ）
１０＠０．６６５
１０’ ０．０６７液滴の生成から
主反応器までの粒子滞留時間を０．２ｓｅｃとすると、
生成粒子濃度を１０７個／ｃｄ程度に抑えることにより
衝突凝集を大幅に低減できる。Particle concentration (particles/cij) Collision frequency (times/5ec)
[email protected] 10' 0.067 Assuming that the particle residence time from droplet generation to the main reactor is 0.2 seconds,
Collision aggregation can be significantly reduced by suppressing the concentration of generated particles to about 107 particles/cd.
浮遊粒子群を通過する光の入射光と透過光量の関係は下
記で求められる。すなわち、入射光量、透過光量を１０
．１０粒子径をχ、粒子個数濃度をＮ、光路長をＬとす
るとき、次式で表される。The relationship between the incident light and the amount of transmitted light passing through the suspended particle group is determined below. In other words, the amount of incident light and the amount of transmitted light are 10
．． 10 When the particle diameter is χ, the particle number concentration is N, and the optical path length is L, it is expressed by the following equation.
■／ｌ０＝ｅｘｐ（−ｔｔ ｚ ｚ ”ＮＬ／４）
上式で吸光係数には、粒子径χと用いる光の波長λの比
にもとづくパラメータπχ／λと、粒子の屈折率で定ま
る。■/l0=exp(-tt z z ”NL/4)
In the above equation, the extinction coefficient is determined by the parameter πχ/λ based on the ratio of the particle diameter χ to the wavelength λ of the light used, and the refractive index of the particles.
そ、こで、０．３ ｎのアルミナ粒子群で光路長し＝１
０ｃｍに、連続光光源を用いると透過光量の比率（Ｉ／
■０）は下記となる。So, with a group of 0.3 n alumina particles, the optical path length is 1.
If a continuous light source is used at 0 cm, the ratio of transmitted light amount (I/
■0) is as follows.
粒子濃度（個／ｃｄ） 透過光量比（１／１０）１
０’ ０．９６
１０” ０．７０
本発明では、反応条件、反応装置等に応じて粒子間衝突
を実質的に無視できる最大濃度を求めて反応を、この濃
度に維持することによって粒子の凝集を防止し、粒度分
布を狭く保ちつつ生産効率を高めている。Particle concentration (particles/cd) Transmitted light amount ratio (1/10) 1
0' 0.96 10" 0.70 In the present invention, the maximum concentration at which collisions between particles can be virtually ignored is determined depending on the reaction conditions, reaction equipment, etc., and the reaction is maintained at this concentration to prevent particle aggregation. This improves production efficiency while maintaining a narrow particle size distribution.
実施例１
第１図に示す装置を使用した。この装置はアルコキシド
蒸発器１、核となる種粒子生成用の水蒸発器２、主反応
用水蒸発器３、核となる種粒子を生成させる核発生器４
、アルコキシド蒸気の凝縮器５、主反応器８、捕集器９
等からなっている。Example 1 The apparatus shown in FIG. 1 was used. This device consists of an alkoxide evaporator 1, a water evaporator 2 for generating seed particles that will become the nucleus, a water evaporator 3 for the main reaction, and a nuclear generator 4 that generates the seed particles that will become the nucleus.
, alkoxide vapor condenser 5, main reactor 8, collector 9
It consists of etc.
希釈搬送ガスである窒素ガスはボンベ１ｏがら流量調節
弁１１を経てアルコキシド液又は水が入っている各蒸発
器１．２．３に送られ、そこでバブリングにより各蒸気
を発生させる。アルコキシド蒸発器ｌを出たアルコキシ
ドを飽和状態で含む窒素ガスはボンベＩＯから流量調節
弁１１を経て分岐路６がら送られてくる窒素ガスと混合
希釈され、さらに水蒸発器２を出た水蒸気を飽和状態で
含む窒素ガスと核発生器４で混合され、そこで加水分解
反応して核となる種粒子を生成する。アルコキシド含有
ガスは必要により分岐管７から抜き取られ、組成分析等
に供される。種粒子を含むガスは凝縮器５で冷却されて
過飽和状態になり、種粒子を核として有核凝縮を行ない
、液滴エアロゾルになる。Nitrogen gas, which is a diluted carrier gas, is sent from a cylinder 1o through a flow control valve 11 to each evaporator 1.2.3 containing an alkoxide liquid or water, where it is bubbled to generate various vapors. Nitrogen gas containing alkoxide in a saturated state leaving the alkoxide evaporator 1 is mixed and diluted with nitrogen gas sent from the cylinder IO through the flow control valve 11 and the branch passage 6, and further water vapor leaving the water evaporator 2 is It is mixed with nitrogen gas contained in a saturated state in a nuclear generator 4, where a hydrolysis reaction occurs to generate seed particles that serve as a nucleus. The alkoxide-containing gas is extracted from the branch pipe 7 as necessary and subjected to compositional analysis or the like. The gas containing the seed particles is cooled to a supersaturated state in the condenser 5, and undergoes nucleated condensation using the seed particles as a nucleus to form droplet aerosol.
この液滴エアロゾルは主反応器８に送られ、凝縮器５と
主反応器８との間には対向する２つの窓を有する光透過
部１７が設けられ、光源１８から発せられた光は光透過
部１７を通って受光部１９で受光され、そこで電気信号
に変えられる。この電気信号は制御部２０で定量され、
その結果に基づいて分岐路６の流量調節弁１１が制御さ
れる。主反応器８に送られた液滴のアルコキシドはそこ
で水蒸発器３から送られた過剰量の水蒸気と混合され、
加水分解反応して個々の液滴が固体粒子に変わる。こう
して生成した固体粒子は捕集器９のフィルターで捕集さ
れる。１２は捕集器９を吸引する真空ポンプである。主
反応器８の出口側には分岐管が設けられ、希釈器１３、
静電分級器１４、凝縮核測定器１５が直列に接続されて
いる。分岐管から抜き出されたガスは希釈器１３におい
て窒素ガスボンベ１６から供給される窒素ガスで希釈さ
れ、静電分級器で分級されて凝縮核測定器１５によって
生成粒子が粒径ごとに計数され、粒度分布や濃度が求め
られる。This droplet aerosol is sent to the main reactor 8, and a light transmitting section 17 having two windows facing each other is provided between the condenser 5 and the main reactor 8, and the light emitted from the light source 18 is The light passes through the transmitting section 17 and is received by the light receiving section 19, where it is converted into an electrical signal. This electrical signal is quantified by the control unit 20,
Based on the result, the flow rate control valve 11 of the branch path 6 is controlled. The droplet alkoxide sent to the main reactor 8 is mixed there with an excess amount of water vapor sent from the water evaporator 3;
Hydrolysis reactions convert individual droplets into solid particles. The solid particles thus generated are collected by the filter of the collector 9. 12 is a vacuum pump that sucks the collector 9. A branch pipe is provided on the outlet side of the main reactor 8, and a diluter 13,
An electrostatic classifier 14 and a condensation nucleus measuring device 15 are connected in series. The gas extracted from the branch pipe is diluted with nitrogen gas supplied from a nitrogen gas cylinder 16 in a diluter 13, classified by an electrostatic classifier, and generated particles are counted by particle size by a condensation nucleus measuring device 15. Particle size distribution and concentration are required.
上記装置を用いてアルミナ粒子の連続製造実験を行なっ
た。アルコキシドにはアルミニウムトリセカンダリ−ブ
トキシド（Ａｆ ［Ｃ，Ｈ５ＣＨ（ＣＨ３） Ｏ） ａ
） ’（ＡＴＳＢ）を用いた。アルコキシド蒸発器ｌか
ら流出するＡＴＳＢ流量を６．２Ｘ１０−’ｍｏｌ／ｗ
ｉｎ、 Ｎｚ流量を６．３Ｘ１０−”ｍｏｌ／ｎ＋ｉｎ
とし、種粒子生成用の水蒸発器２から流出するＨ 、
Ｏ流量を４．５Ｘ１０−’＋ｇｏｌ／＠ｉｎ、Ｎｚ流量
を６．７ Ｘ １０− ’ｍｏｌ／ｗｉｎ、主反応用水
蒸発器３から流出するＨ、Ｏ流量を１．９Ｘ１０−”ａ
＋ｏｌ／ｗｉｎ、Ｎ２流量を２−８ Ｘ １０− ｚｍ
ｏｌ／ｓｉｎとした。分岐路６へ送るＮ２流量を制御部
２０により制御して光透過部１７を通過するガス中の液
滴数を３Ｘ１０’個／ｃｄになるように調節した。核発
生器の温度は１６０〜１８０″Ｃ８圧力は７８０〜８６
０Ｔｏｒｒに制御し、凝縮器の温度は７９°Ｃにした。A continuous production experiment of alumina particles was conducted using the above apparatus. The alkoxide includes aluminum trisec-butoxide (Af[C,H5CH(CH3)O) a
)' (ATSB) was used. The ATSB flow rate flowing out from the alkoxide evaporator l is 6.2X10-'mol/w.
in, Nz flow rate to 6.3X10-”mol/n+in
and H flowing out from the water evaporator 2 for seed particle generation,
The O flow rate is 4.5X10-'+gol/@in, the Nz flow rate is 6.7X10-'mol/win, and the H and O flow rate flowing out from the main reaction water evaporator 3 is 1.9X10-''a.
+ol/win, N2 flow rate 2-8 x 10-zm
It was set as ol/sin. The flow rate of N2 sent to the branch path 6 was controlled by the control unit 20, and the number of droplets in the gas passing through the light transmission unit 17 was adjusted to 3×10′ droplets/cd. Nuclear generator temperature is 160~180'' C8 pressure is 780~86
It was controlled at 0 Torr, and the temperature of the condenser was 79°C.
主反応器の温度は５０°Ｃに、そして圧力は圧力は７８
０〜８５０Ｔｏｒｒに制御した。The main reactor temperature is 50°C and the pressure is 78°C.
It was controlled at 0 to 850 Torr.
定常状態における主反応器８から流出するガスを分析し
たところ、固体粒子の濃度は２．１３Ｘ１０７個／ｃｄ
であり、幾何平均粒径は０．１７ｍ、幾何標準偏差は１
．２９であった。粒度分布を第２図に示す。この固体粒
子は完全な球形であった。When the gas flowing out from the main reactor 8 in steady state was analyzed, the concentration of solid particles was 2.13 x 107 particles/cd.
The geometric mean particle size is 0.17 m, and the geometric standard deviation is 1.
．． It was 29. The particle size distribution is shown in Figure 2. The solid particles were perfectly spherical.
得られた固体粒子をマツフル炉で１２００°Ｃで１時間
仮焼し、結晶構造をＸ線回折により調べたところ完全に
αアルミナになっていた。このものも完全な球形であっ
た。The obtained solid particles were calcined in a Matsufuru furnace at 1200°C for 1 hour, and the crystal structure was examined by X-ray diffraction, and it was found to be completely α-alumina. This one was also perfectly spherical.
本実施例で用いた原料ＡＴＳＢ中の金属元素をＩＣＰ発
光分光法により測定した結果、Ａ２の純度は９９．５％
であった。一方、仮焼したアルミナ粉を滴定・他により
組成分析した結果も、金属元素中のＡｌの比率は９９．
５％であり、仮焼粉は原料の純度を保持していた。As a result of measuring the metal elements in the raw material ATSB used in this example by ICP emission spectroscopy, the purity of A2 was 99.5%.
Met. On the other hand, as a result of compositional analysis of calcined alumina powder by titration and other methods, the ratio of Al in the metal elements was 99.
5%, and the calcined powder maintained the purity of the raw material.
本発明の方法により生産性を低下させずに粒度分布が極
めて狭い真球状の球形超微粒子を容易に、しかも高純度
で得ることができる。By the method of the present invention, spherical ultrafine particles having an extremely narrow particle size distribution can be easily obtained with high purity without reducing productivity.
第１図は本発明の実施例で使用された装置の概略を示す
フローシートであり、第２図は実施例で得られた粒子の
粒度分布図である。FIG. 1 is a flow sheet showing an outline of the apparatus used in the examples of the present invention, and FIG. 2 is a particle size distribution diagram of particles obtained in the examples.
Claims (1)
うえで両者を反応させて固体微粒子群を得る液滴ＣＶＤ
において、微細液滴群又は固体微粒子群を透過する光量
を制御量とし、液滴の核となる種粒子を生成する反応器
に送入する原料濃度を操作量として生成する種粒子及び
前記固体粒子の濃度を制御することを特徴とする球形超
微粒子の気相製造法Droplet CVD in which one of the raw materials is made into a group of fine droplets, the other is made into a gas state, and then both are reacted to obtain a group of solid fine particles.
In , the amount of light transmitted through the fine droplet group or the solid particulate group is used as the control amount, and the seed particles and the solid particles to be generated are used as the manipulated variable, the concentration of the raw material sent to the reactor that generates the seed particles that become the nucleus of the droplet. A gas phase production method for spherical ultrafine particles characterized by controlling the concentration of
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29715390A JPH04170306A (en) | 1990-11-05 | 1990-11-05 | Particle concentration control in vapor phase production of superfine particle |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP29715390A JPH04170306A (en) | 1990-11-05 | 1990-11-05 | Particle concentration control in vapor phase production of superfine particle |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04170306A true JPH04170306A (en) | 1992-06-18 |
Family
ID=17842884
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP29715390A Pending JPH04170306A (en) | 1990-11-05 | 1990-11-05 | Particle concentration control in vapor phase production of superfine particle |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04170306A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009042075A3 (en) * | 2007-09-21 | 2009-07-23 | Nanogram Corp | Uniform aerosol delivery for flow-based pyrolysis for inorganic material synthesis |
| JP2010520044A (en) * | 2007-02-28 | 2010-06-10 | コーニング インコーポレイテッド | Apparatus and method for electrostatically deposited aerosol particles |
-
1990
- 1990-11-05 JP JP29715390A patent/JPH04170306A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010520044A (en) * | 2007-02-28 | 2010-06-10 | コーニング インコーポレイテッド | Apparatus and method for electrostatically deposited aerosol particles |
| WO2009042075A3 (en) * | 2007-09-21 | 2009-07-23 | Nanogram Corp | Uniform aerosol delivery for flow-based pyrolysis for inorganic material synthesis |
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