JPH0687608A - Production of monodispersive spherical silica - Google Patents
Production of monodispersive spherical silicaInfo
- Publication number
- JPH0687608A JPH0687608A JP26308892A JP26308892A JPH0687608A JP H0687608 A JPH0687608 A JP H0687608A JP 26308892 A JP26308892 A JP 26308892A JP 26308892 A JP26308892 A JP 26308892A JP H0687608 A JPH0687608 A JP H0687608A
- Authority
- JP
- Japan
- Prior art keywords
- liquid
- reaction
- alkoxysilane
- silica
- particles
- 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.)
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Links
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- Silicon Compounds (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】粒径がサブミクロンからミクロン
単位の球状で粒度分布が極めて狭い粒子からなるシリカ
の粉粒は、液晶表示装置のスペーサ、各種の充填材、ク
ロマトグラフィー用充填材、精密研磨材等への用途に適
する材料として注目されている。本発明はこのようなシ
リカの粉粒を得るため、球状シリカのシードを成長させ
て大径化する方法、特にアルコキシシランを加水分解お
よび脱水縮重合して平均粒子径が0.1ないし10μm
の単分散球状シリカを得る新規な方法に関する。本明細
書において、単分散とは粒度分布の変動係数(平均粒子
径を基準とする粒子径の標準偏差の百分率値)が15%
以下であることをいう。[Industrial application] Silica powder consisting of spherical particles with a particle size of submicron to micron and extremely narrow particle size distribution is used for spacers of liquid crystal display devices, various packing materials, packing materials for chromatography, and precision packing materials. It has attracted attention as a material suitable for use as an abrasive. In order to obtain such silica powder particles, the present invention is a method of growing a spherical silica seed to increase the particle size, particularly by hydrolyzing and dehydrating polycondensation of alkoxysilane to give an average particle size of 0.1 to 10 μm.
The present invention relates to a novel method for obtaining monodisperse spherical silica. In the present specification, monodisperse means that the coefficient of variation of particle size distribution (percentage value of standard deviation of particle size based on average particle size) is 15%.
It means the following.
【0002】[0002]
【従来の技術】アルコキシシランを加水分解・脱水縮重
合して0.05〜2μm程度の単分散球状シリカを得る
方法は公知である(W.Stober,Journal
ofColloid & Interface Sc
i.,26,62−69,1968)。この反応をテト
ラエトキシシランを例にとって述べると次のとおりであ
る。まず、テトラエトキシシランをエチルアルコールで
希釈した原料液に、必要量の水とアンモニア水等のpH
調整剤とを添加し攪拌して混合液にすると、次の化1式
に示すように、原料液中のエトキシシランが添加液中の
水により加水分解されて、ケイ酸とエチルアルコールに
なる。ついで、ケイ酸の液中濃度が過飽和点に達する
と、化2式に示すように、その脱水縮重合により極めて
微細なシリカが生成し、これが次第に結集して大径化す
ることにより、反応条件に応じて比較的粒径の揃った球
状シリカとなる。2. Description of the Related Art A method for obtaining monodisperse spherical silica of about 0.05 to 2 .mu.m by hydrolyzing and dehydrating polycondensed alkoxysilane is known (W. Stober, Journal).
ofColloid & Interface Sc
i. , 26, 62-69, 1968). This reaction will be described below using tetraethoxysilane as an example. First, in a raw material liquid prepared by diluting tetraethoxysilane with ethyl alcohol, adjust the pH of necessary amount of water and ammonia water.
When a regulator is added and stirred to form a mixed liquid, ethoxysilane in the raw material liquid is hydrolyzed by water in the added liquid to form silicic acid and ethyl alcohol, as shown in the following chemical formula 1. Then, when the concentration of silicic acid in the liquid reaches the supersaturation point, extremely fine silica is produced by dehydration polycondensation, as shown in Chemical formula 2, and these are gradually aggregated to increase the size of the reaction conditions. The spherical silica has a relatively uniform particle size.
【0003】[0003]
【化1】 Si(OC2H5)4+4H2O→Si(OH)4+4C2H5OHEmbedded image Si (OC 2 H 5 ) 4 + 4H 2 O → Si (OH) 4 + 4C 2 H 5 OH
【0004】[0004]
【化2】Si(OH)4+→SiO2+2H2OEmbedded image Si (OH) 4 + → SiO 2 + 2H 2 O
【0005】この間に、混合液は透明な状態から半透明
に転じ、透明度が減じて白濁の度を増す。可視的に透明
からやや半透明になった状態で、すでに極めて微細なシ
リカが生成しており、それが結集して大径化されるにつ
れて不透明ないし白濁の状態になるが、この状態でも反
応液内には多数の大径化したシリカと小径のシリカない
し微細なシリカが多少混在しており、この混合液から直
接に10μmといった大径の単分散球状シリカを得るこ
とは至難である。In the meantime, the mixed solution changes from a transparent state to a semitransparent state, the transparency is reduced and the degree of white turbidity is increased. Very fine silica has already been formed in a state where it is visibly transparent to slightly translucent, and becomes opaque or cloudy as it aggregates and becomes larger in diameter. A large number of large-diameter silica and a small amount of silica or fine silica are mixed therein, and it is difficult to directly obtain a monodisperse spherical silica having a large diameter of 10 μm from this mixed solution.
【0006】そこで、この球状シリカを含む液を反応液
とし、またはこの液から分別して得た球状シリカを別に
調整した分散媒に分散させてなる液を反応液として、こ
れにアルコキシシランをアルコール等の有機溶媒に溶か
した原料液を連続滴下するとともに、反応に必要な水お
よびpH調整液等の添加液を連続滴下し、反応液中にお
いて上記化1式および化2式に示した反応により新たに
生成した微細なシリカをシードに結集合体させて、さら
に大径化する。このことも知られている(特開昭62−
275005号公報、特開昭63−210016号公報
等)。Therefore, a liquid containing the spherical silica is used as a reaction liquid, or a liquid obtained by dispersing spherical silica obtained by fractionating the liquid in a separately prepared dispersion medium is used as a reaction liquid, and alkoxysilane is added to the liquid. The raw material liquid dissolved in the organic solvent is continuously added dropwise, and addition liquids such as water and pH adjusting liquid necessary for the reaction are continuously added dropwise, and the reaction liquid shown in the above chemical formula 1 and chemical formula 2 is used. The fine silica particles produced in step (3) are aggregated with seeds to further increase the diameter. This is also known (Japanese Patent Laid-Open No. 62-62-62).
275005, JP-A-63-21016, etc.).
【0007】このシード成長方式では一般に、シードを
分散させた一槽内の反応液中に、上記のアルコキシシラ
ン原料液を逐次連続滴下して供給するほか、反応に必要
な水およびpH調整用の添加液を別々の供給源から滴下
供給し、上記原料アルコキシシランの加水分解反応とこ
れに続く脱水縮重合反応によるシリカの生成とを、上記
反応液を収容した一槽内で並行して進行させる。この方
式によると確かにシードの径を増大させることができる
が、それと同時に反応液中において上記シードの成長に
寄与しない微細なシリカおよび小径の球状シリカを新た
に生成しやすく、シードの成長も不均一となり、その結
果粒度分布のシャープな所期の粒径の球状シリカを安定
して製造しにくいのが実情である。In this seed growth method, in general, the above-mentioned alkoxysilane raw material liquid is successively and dropwise added to the reaction liquid in one tank in which the seed is dispersed, and water for adjusting the pH and pH necessary for the reaction are adjusted. The additive liquid is dropped and supplied from different supply sources, and the hydrolysis reaction of the raw material alkoxysilane and the subsequent production of silica by the dehydration polycondensation reaction are allowed to proceed in parallel in one tank containing the reaction liquid. . According to this method, the diameter of the seed can be certainly increased, but at the same time, it is easy to newly generate fine silica and spherical silica having a small diameter which do not contribute to the growth of the seed in the reaction solution, and the seed growth is also unsuccessful. In reality, it is difficult to stably produce spherical silica having a desired particle size and a uniform particle size distribution.
【0008】[0008]
【発明が解決しようとする課題】本発明の目的は、従来
の製造技術にみられる上記の欠点を解消し、平均粒径が
0.1〜10μmの範囲にあり、変動係数が15%以下
の球状シリカを容易かつ安定に得ることができる新規な
製造方法を提供することにある。The object of the present invention is to solve the above-mentioned drawbacks found in the conventional manufacturing techniques, to have an average particle size in the range of 0.1 to 10 μm, and a coefficient of variation of 15% or less. It is an object of the present invention to provide a novel production method capable of easily and stably obtaining spherical silica.
【0009】[0009]
【課題を解決するための手段】本発明者らは前記目的を
達成するための研究を重ねた結果、従来のシード成長法
にみられる上述の欠点は、反応液中に小量のアルコキシ
シランを含む原料液と水やpH調整用の添加液とを別々
に逐次滴下して供給し、反応液中でアルコキシシランを
加水分解するため、反応液を通常の攪拌操作によって攪
拌したのでは、上記原料液と各添加液とを大容量の反応
液全体に均等に混和し難いからではないかと推測した。
そして実験により、従来のシード成長法によるときは上
記一槽内の反応液中での加水分解反応とこれに続く縮重
合による新たなシリカ生成の状態が局所的に不均質とな
り、その結果、生成した微細なシリカのシードへの結集
合体による粒子成長が、局所的に不均質化することを確
かめた。The inventors of the present invention have conducted extensive research to achieve the above-mentioned object, and as a result, the above-mentioned drawbacks of the conventional seed growth method have been found to result in the presence of a small amount of alkoxysilane in the reaction solution. Since the raw material liquid containing water and the additive liquid for water and pH adjustment are successively added dropwise and the alkoxysilane is hydrolyzed in the reaction liquid, the reaction liquid is stirred by a normal stirring operation. It was presumed that it was difficult to mix the liquid and each additive liquid uniformly in the whole reaction liquid of large volume.
Then, according to the experiment, when the conventional seed growth method was used, the state of the new silica formation due to the hydrolysis reaction in the reaction solution in the above tank and the subsequent condensation polymerization became locally inhomogeneous. It was confirmed that the particle growth by aggregates on the seeds of finely divided silica was locally heterogeneous.
【0010】そこで本発明者らは、上記課題の解決手段
を検討した結果、つぎの方法が有効であることをみいだ
し本発明に至った。すなわち、本発明の解決原理は、添
加するアルコキシシランの加水分解反応とシードの成長
とが一槽の反応液中で同時並行するのを可及的に避け、
両者を別々の場所で分けて行わせるようにするにある。
この2つの過程を一槽内で併存させることなく、別々の
過程に分けて行うことによって所期の単分散球状シリカ
を容易に安定して得ることに成功した。The inventors of the present invention have studied the means for solving the above problems, and have found that the following method is effective, and have reached the present invention. That is, the solution principle of the present invention avoids, as much as possible, the hydrolysis reaction of the added alkoxysilane and the growth of the seed in the reaction solution in one tank at the same time.
There is a way to do both in separate places.
We succeeded in easily and stably obtaining the desired monodisperse spherical silica by performing these two processes separately in one tank without coexisting them in one tank.
【0011】この解決原理に依拠した本発明の特徴は、
特許請求の範囲に記載のとおり、アルコキシシラン、
アルカリ調整水および有機溶媒を、連続的に予備反応槽
内に注加し混合して、アルコキシシランの加水分解物で
あるケイ酸を含む液とする予備処理工程と、上記加水
分解物を含む液を、アルカリ性有機分散媒に球状シリカ
のシードを分散させた反応液が収容された主反応槽内に
連続的に供給して、上記加水分解物の脱水縮合反応によ
り生成した微細なシリカを上記シードの表面に付着させ
て粒子を成長させ大径化する主反応工程とを含む単分散
球状シリカの製造方法にある。The features of the present invention based on this solution principle are:
As described in the claims, alkoxysilane,
Alkali-adjusted water and an organic solvent are continuously poured into a preliminary reaction tank and mixed to prepare a liquid containing silicic acid which is a hydrolyzate of alkoxysilane, and a liquid containing the hydrolyzate. Is continuously supplied to the main reaction tank in which the reaction liquid in which the spherical silica seed is dispersed in the alkaline organic dispersion medium is stored, and the fine silica produced by the dehydration condensation reaction of the hydrolyzate is used as the seed. And a main reaction step of adhering to the surface of the particles to grow the particles to increase the diameter thereof.
【0012】(発明の一般説明)本発明方法の構成の特
徴を順次説明すると以下のとおりである。 予備処理工程;予備処理工程では、有機溶媒中のアルコ
キシシランを水およびアルカリ調整水を用いて加水分解
し、ケイ酸を含む液を調整する。アルコキシシラン、ア
ルカリ調整水および有機溶媒は、従来アルコキシシラン
の加水分解・縮合反応を利用したシリカ粒子の製造に用
いられるものであればよい。アルコキシシランとして
は、テトラエトキシシラン(ケイ酸エチル)やテトラメ
トキシシラン(ケイ酸メチル)が好適であり入手も容易
である。有機溶媒としては、エタノール、メタノールお
よびプロパノール等が好適である。アルカリ源として
は、アンモニアや苛性ソーダを用いるのがよい。(General Description of the Invention) The features of the constitution of the method of the present invention will be described below in order. Pretreatment step: In the pretreatment step, the alkoxysilane in the organic solvent is hydrolyzed with water and alkali adjusted water to prepare a liquid containing silicic acid. The alkoxysilane, alkali-adjusted water and organic solvent may be those conventionally used in the production of silica particles utilizing the hydrolysis / condensation reaction of alkoxysilane. As the alkoxysilane, tetraethoxysilane (ethyl silicate) or tetramethoxysilane (methyl silicate) is suitable and easily available. As the organic solvent, ethanol, methanol, propanol and the like are suitable. Ammonia or caustic soda is preferably used as the alkali source.
【0013】アルコキシシランは、予め有機溶媒に溶か
しておくことが好ましい。予備反応槽中に投入される液
中のアルコキシシランの濃度は0.1mol/l〜2m
ol/lの範囲に調整するのがよい。(この場合の溶媒
中の濃度はいずれも15vol.%〜40vol.%の
濃度範囲が好適である。アルコキシシランの溶媒中の濃
度がこの範囲外だと不都合を生ずる。) アルカリは、予備処理工程におけるアルコキシシランの
加水分解および主反応工程におけるシリカの生成のため
の縮重合において、反応触媒として作用する。反応速度
の調整とシリカ粒子の溶解防止のため、水を加えてpH
11〜14のアルカリ調整水として用いる。アルカリ調
整水中の水は、予備処理の反応液に水の濃度が1〜50
mol/lとなるよう調整しておく。The alkoxysilane is preferably dissolved in an organic solvent in advance. The concentration of alkoxysilane in the liquid charged into the preliminary reaction tank is 0.1 mol / l to 2 m.
It is better to adjust to the range of ol / l. (In this case, the concentration in the solvent is preferably in the range of 15 vol.% To 40 vol.%. If the concentration of the alkoxysilane in the solvent is out of this range, disadvantage occurs.) Alkali pretreatment step Acts as a reaction catalyst in the polycondensation for the hydrolysis of the alkoxysilane in and the formation of silica in the main reaction step. Add water to adjust the reaction rate and prevent dissolution of silica particles.
Used as alkali adjusted water of 11-14. Water in alkali-adjusted water has a water concentration of 1 to 50 in the reaction solution of the pretreatment.
Adjust so that it becomes mol / l.
【0014】アルカリ調整水も、予め有機溶媒に溶かし
ておくのが好ましいが、溶媒中の濃度は12.5vo
l.%〜50vol.%とするのが好適である。溶媒中
のアルカリ調整水の濃度が高すぎると、加水分解が大き
くなりすぎ、また低すぎると加水分解速度が小さくなっ
て未反応のアルコキシシランが残り、いずれも主反応工
程でのシリカ粒子の粒径の制御が困難になる。It is preferable that alkaline adjusted water is also dissolved in an organic solvent in advance, but the concentration in the solvent is 12.5 vo.
l. % To 50 vol. % Is preferable. If the concentration of the alkali-adjusted water in the solvent is too high, the hydrolysis will be too large, and if it is too low, the hydrolysis rate will be small and unreacted alkoxysilane will remain, both of which are particles of silica particles in the main reaction step. It becomes difficult to control the diameter.
【0015】予備処理に際して、所定のpH値に調整し
たアルカリ調整水を有機溶媒に溶解した後、この液の温
度を予備処理槽の設定温度に合わせ、またアルコキシシ
ランも所定濃度となるよう有機溶媒に溶解した後、この
液の温度を同様に合わせる。ついで、これらの液を予備
処理槽に連続して注加し、攪拌混合する。槽内では主と
して化1式の加水分解反応が生じ発熱するが、熱量は小
さいため混合反応液の温度調整は容易に行い得る。反応
温度は、アルコキシシランや有機溶媒、アルカリ調整水
の沸点、凝固点を考慮して適宜に決める。温度は通常0
〜70℃の範囲が好ましい。予備反応の温度は、主反応
の温度と一致させる必要はなく、最終製品の粒径分布や
製造効率を向上させるため異なる温度とすることができ
る。In the pretreatment, alkali adjusted water adjusted to a predetermined pH value is dissolved in an organic solvent, the temperature of this solution is adjusted to the set temperature of the pretreatment tank, and the alkoxysilane is also adjusted to a predetermined concentration. After dissolving in, the temperature of this solution is adjusted in the same manner. Then, these solutions are continuously added to the pretreatment tank, and mixed by stirring. Although the hydrolysis reaction of the chemical formula 1 mainly occurs in the tank to generate heat, the temperature of the mixed reaction liquid can be easily adjusted because the amount of heat is small. The reaction temperature is appropriately determined in consideration of the boiling point and freezing point of the alkoxysilane, the organic solvent, and the alkali-adjusted water. Temperature is usually 0
The range of ˜70 ° C. is preferred. The temperature of the preliminary reaction does not have to be the same as the temperature of the main reaction, and can be different temperatures in order to improve the particle size distribution of the final product and the production efficiency.
【0016】予備処理工程を終了した液の主反応槽内へ
の供給速度は、主反応槽内のシリカ種粒子の濃度および
液量により異なるが、速度が過大であると自己核発生が
生じやすく、速度が過小になると粒子成長が遅滞するの
で、一般にシリカのシード1個当たり加水分解物3×1
0-11〜3×10-14mol/時以下とすることが好まし
い。The supply rate of the liquid after the pretreatment process into the main reaction tank varies depending on the concentration and the amount of the silica seed particles in the main reaction tank. If the speed is too high, self-nucleation is likely to occur. However, if the speed is too low, particle growth will be delayed, so 3 x 1 of hydrolyzate per silica seed is generally used.
It is preferably 0 -11 to 3 × 10 -14 mol / hour or less.
【0017】主反応工程;予め主反応槽に収容するシリ
カのシードは、粒径が0.5μm以下にあり、粒径の変
動係数が15%以下のものがよい。シード粒子はアルカ
リ性有機溶液中に分散させておく必要があり、その数濃
度が低いと反応槽内で生成した微細なシリカがシードに
集結合体せずに独立した自己核を生成して粒度分布が悪
化し、数濃度が高いと成長した球状シリカ粒子が凝集し
あって粗大化するので、1×1010ケ/l〜1×1015
ケ/lの範囲、好適には1×1013ケ/l〜1×1014
ケ/lの範囲とすべきである。このシード粒子を分散さ
せる有機分散媒としては、予備処理工程で使用する上記
溶媒と同様のものを使用することができる。この液のp
Hは、縮合反応を安定化させ粒径の揃った球状のシリカ
粒子を得るため、前記適宜のアルカリ源を用いてpH値
を調整し、予備処理工程を経て供給されるケイ酸溶液の
pH値と一致させることが好ましい。Main reaction step: The silica seed to be stored in the main reaction tank in advance has a particle size of 0.5 μm or less and a particle size variation coefficient of 15% or less. It is necessary to disperse the seed particles in an alkaline organic solution, and if the number concentration is low, the fine silica particles generated in the reaction tank will not form aggregates in the seeds and will form independent self-nuclei, resulting in a particle size distribution. When the number density is high, the grown spherical silica particles are aggregated with each other and become coarse. Therefore, 1 × 10 10 pieces / l to 1 × 10 15
Ke / l, preferably 1 × 10 13 ke / l to 1 × 10 14
It should be in the range of 1 / l. As the organic dispersion medium for dispersing the seed particles, the same solvent as that used in the pretreatment step can be used. P of this liquid
In order to stabilize the condensation reaction and obtain spherical silica particles having a uniform particle size, H is a pH value of the silicic acid solution that is supplied through a pretreatment step after adjusting the pH value by using the appropriate alkali source. It is preferable to match with.
【0018】[0018]
【実施例】つぎに、本発明の好適な実施例について比較
例とともに説明する。 (実施例1)縦長円筒状で、内部には液の先走り防止機
能をもたせるため垂直軸に複数個の水平羽根を取り付け
た攪拌棒を備えた予備反応槽(容量10ml)の上部か
ら、マイクロチューブポンプにより、エトキシシランを
1.6mol/l含むエタノール溶液と、pH12.5
のアンモニア水を25vol.%含むエタノール溶液と
を、それぞれ0.25ml/分の速度で注加して攪拌し
混合した。この混合液のpHは11.9であり、液温は
20℃である。注加液の槽内平均滞在時間は1分であ
り、この間に液中のエトキシシランは所要の反応を終了
し、均一な加水分解溶液すなわちケイ酸溶液となって予
備反応層の下部に達する。一方主反応層(容量1l)内
には、予めアルコキシシランの加水分解・縮重合によっ
て得られた平均粒子径0.343μm、変動係数9%の
シリカ単分散粒子を6×1013ケ/lの個数濃度となる
ように、アンモニアを含むアルカリ性エタノール溶媒1
00mlに希釈分散させて収容してある。EXAMPLES Next, preferred examples of the present invention will be described together with comparative examples. (Example 1) A microtube from the upper part of a preliminary reaction tank (capacity: 10 ml) having a vertically long cylindrical shape and having a stirring rod in which a plurality of horizontal blades are attached to a vertical axis in order to have a function of preventing the advance of liquid. With an ethanol solution containing 1.6 mol / l of ethoxysilane by a pump, pH 12.5
Ammonia water of 25 vol. % Ethanol solution was added at a rate of 0.25 ml / min, and the mixture was stirred and mixed. The pH of this mixed liquid is 11.9 and the liquid temperature is 20 ° C. The average residence time of the pouring liquid in the tank is 1 minute, during which the ethoxysilane in the liquid finishes the required reaction and becomes a uniform hydrolysis solution, that is, a silicic acid solution, and reaches the lower part of the preliminary reaction layer. On the other hand, in the main reaction layer (capacity 1 liter), silica monodisperse particles having an average particle diameter of 0.343 μm and a coefficient of variation of 9%, which were previously obtained by hydrolysis / polycondensation of alkoxysilane, of 6 × 10 13 pieces / l were used. Alkaline ethanol solvent containing ammonia so that the number concentration becomes 1
It is stored after being diluted and dispersed in 00 ml.
【0019】ついで、予備反応槽の下部流出口から上記
加水分解によって得られたケイ酸を含む溶液を連続的に
主反応槽に滴下供給し、主反応槽内のシリカのシードを
分散したアルカリ性有機溶媒(温度;10℃)と攪拌混
合することによってシード粒子からの粒子成長を行わせ
た。23時間後にケイ酸溶液の供給を停止し、得られた
スラリーを固液分離し、SEM写真観察によって粒子径
を評価したところ、平均粒径が1.60μm、変動係数
が4%の単分散球状シリカ粒子を得ることができた。な
お、SEMによる写真観察は日本電子株式会社製JXA
−840A型を利用して行った。Then, a solution containing silicic acid obtained by the above hydrolysis is continuously added dropwise to the main reaction tank through the lower outlet of the preliminary reaction tank, and an alkaline organic material in which silica seeds are dispersed in the main reaction tank. Particle growth from seed particles was performed by stirring and mixing with a solvent (temperature; 10 ° C.). After 23 hours, the supply of the silicic acid solution was stopped, the obtained slurry was subjected to solid-liquid separation, and the particle size was evaluated by SEM photograph observation. The average particle size was 1.60 μm, and the variation coefficient was 4%. Silica particles could be obtained. In addition, photograph observation by SEM is JXA manufactured by JEOL Ltd.
-840A type was used.
【0020】(実施例2)実施例1で用いた予備反応槽
(ただし、容量20ml)を用い、その上部からマイク
ロチューブポンプにより、プロポキシシランを1.6m
ol/l含むエタノール溶液と、pH12.5のアンモ
ニア水を25vol.%含むエタノール溶液とをそれぞ
れ0.25ml/分の速度で注加して攪拌し混合した。
この混合液のpHは11.9であり、液温は10℃であ
る。注加液の槽内平均滞在時間は2分であり、この間に
液中のプロポキシシランは所要の反応を終了し、均一な
加水分解溶液すなわちケイ酸溶液となって予備反応槽の
下部に達する。一方主反応槽(容量1l)内には、実施
例1と同様、予めアルコキシシランの加水分解・縮重合
によって得られた平均粒子径0.343μm、変動係数
9%のシリカ単分散粒子を6×1013ケ/lの個数濃度
となるように、アンモニアを含むアルカリ性エタノール
溶媒100mlに希釈分散させて収容してある。Example 2 Using the preliminary reaction vessel used in Example 1 (with a capacity of 20 ml), propoxysilane was added to 1.6 m from the top by a microtube pump.
ol / l of an ethanol solution and ammonia water having a pH of 12.5 at 25 vol. % Ethanol solution was added at a rate of 0.25 ml / min, and the mixture was stirred and mixed.
The pH of this mixed solution is 11.9 and the solution temperature is 10 ° C. The average residence time of the pouring liquid in the tank is 2 minutes, during which the propoxysilane in the liquid completes the required reaction and becomes a uniform hydrolyzed solution, that is, silicic acid solution, reaching the lower part of the preliminary reaction tank. On the other hand, in the same manner as in Example 1, 6 × of silica monodisperse particles having an average particle diameter of 0.343 μm and a coefficient of variation of 9%, which were previously obtained by hydrolysis / condensation of alkoxysilane, were placed in the main reaction tank (volume: 1 l). It is stored by being diluted and dispersed in 100 ml of an alkaline ethanol solvent containing ammonia so that the number concentration thereof is 10 13 pieces / l.
【0021】ついで、予備反応槽の下部流出口から上記
加水分解によって得られたケイ酸を含む溶液を連続的に
主反応槽に滴下供給し、主反応槽内のシリカのシードを
分散したアルカリ性有機溶媒(温度;8℃)と攪拌混合
することによってシード粒子からの粒子成長を行わせ
た。25時間後にケイ酸溶液の供給を停止し、得られた
スラリーを固液分離し、SEM写真観察によって粒子径
を評価したところ、平均粒径が2.53μm、変動係数
が3%の単分散球状シリカ粒子を得ることができた。Then, a solution containing silicic acid obtained by the above hydrolysis is continuously added dropwise to the main reaction tank through the lower outlet of the preliminary reaction tank, and an alkaline organic material in which silica seeds are dispersed in the main reaction tank is supplied. Particle growth from seed particles was performed by stirring and mixing with a solvent (temperature; 8 ° C.). After 25 hours, the supply of the silicic acid solution was stopped, the obtained slurry was subjected to solid-liquid separation, and the particle size was evaluated by SEM photograph observation. The average particle size was 2.53 μm, and the variation coefficient was 3%. Silica particles could be obtained.
【0022】(比較例)実施例1において用いたのと同
一組成のエトキシシランのエタノール溶液およびアルカ
リ調整水エタノール溶液を、同実施例で用いたのと同一
のシリカのシード粒子のエタノール分散液を入れた主反
応槽内にそれぞれ直接滴下供給し、実施例と同様の条件
でシード粒子を成長させた。得られたスラリー生成物に
ついて、前同様に粒子径を評価したところ、その平均粒
径が0.95μmであって、粒子径分布図の形状は平均
粒径を中心とするピークから粒子径の小さな方にかけて
長く裾を引いており、変動係数が23.3%の多分散な
粒子分布を示していた。したがって、予備処理工程によ
りアルコキシシランを予め加水分解させてから、この加
水分解物を含む液を、シリカの種粒子を分散させた主反
応液に加えて粒子の成長を制御することがシリカ粒子を
安定的に効率よく成長させるのに必要かつ有益であるこ
とが実証された。Comparative Example An ethanol solution of ethoxysilane and an ethanol solution of alkali adjusted water having the same composition as that used in Example 1 and an ethanol dispersion of the same silica seed particles as used in the same example were used. Each of them was directly dropped into the main reaction vessel and charged to grow seed particles under the same conditions as in the example. The particle size of the obtained slurry product was evaluated in the same manner as above. The average particle size was 0.95 μm, and the shape of the particle size distribution chart was such that the particle size was smaller than the peak centered on the average particle size. It had a long trailing edge and showed a polydisperse particle distribution with a coefficient of variation of 23.3%. Therefore, it is possible to control the growth of particles by preliminarily hydrolyzing the alkoxysilane in the pretreatment step and then adding a liquid containing this hydrolyzate to the main reaction liquid in which the silica seed particles are dispersed to control the particle growth. It has been proved necessary and beneficial for stable and efficient growth.
【0023】以上に本発明の実施例を示したが、本発明
の実施は上述した実施例に限られるものではない。すな
わち、実施例1の方法によって得た平均粒径が1.6μ
m程度のシリカ粒子を主反応液から分別し、これをシー
ドとして分散した液を主反応液として用い、さらに前同
様の予備反応液を滴下して粒子の成長を行うことも容易
であり、これによって任意の粒径をもつ種々の用途に適
する単分散球状シリカの粉粒を容易に得ることができ
る。Although the embodiments of the present invention have been described above, the embodiments of the present invention are not limited to the above-mentioned embodiments. That is, the average particle size obtained by the method of Example 1 was 1.6 μm.
It is also easy to separate silica particles of about m from the main reaction solution, use this as a seed and disperse the solution as the main reaction solution, and further drop a preliminary reaction solution similar to the previous one to grow the particles. Thus, it is possible to easily obtain powder particles of monodispersed spherical silica having an arbitrary particle diameter and suitable for various uses.
【0024】[0024]
【発明の効果】上述のとおり、本発明のシリカ種粒子か
ら単分散球状シリカ粒子を成長させる方法は、アルコキ
シシランを加水分解させる予備処理工程とこの工程で得
られた加水分解物を溶媒中に分散したシリカ種粒子の表
面上に縮重合させ、粒子を成長させる主反応工程を分け
て行うことにより、平均粒径が0.1〜10μmで、変
動係数が15%以下の単分散球状シリカの粒子を、従来
法に比べて容易に効率よく得ることができるので、産業
上有用である。As described above, the method of growing monodisperse spherical silica particles from the silica seed particles of the present invention is carried out by preliminarily treating the alkoxysilane with a hydrolyzate obtained in this step in a solvent. By subjecting the dispersed silica seed particles to polycondensation on the surface and performing the main reaction step of growing the particles separately, it is possible to obtain monodisperse spherical silica having an average particle diameter of 0.1 to 10 μm and a coefficient of variation of 15% or less. Since the particles can be easily and efficiently obtained as compared with the conventional method, they are industrially useful.
Claims (1)
よび有機溶媒を、連続的に予備反応槽内に注加し混合し
て、アルコキシシランの加水分解物であるケイ酸を含む
液とする予備処理工程と、上記加水分解物を含む液
を、アルカリ性有機分散媒に球状シリカのシードを分散
させた反応液が収容された主反応槽内に連続的に供給し
て、上記加水分解物の脱水縮合反応により生成した微細
なシリカを上記シードの表面に付着させて粒子を成長さ
せ大径化する主反応工程とを含む単分散球状シリカの製
造方法。1. A pretreatment step of continuously adding and mixing an alkoxysilane, alkali-adjusted water and an organic solvent into a preliminary reaction tank to obtain a liquid containing silicic acid which is a hydrolyzate of alkoxysilane. , A liquid containing the hydrolyzate is continuously supplied into a main reaction tank containing a reaction liquid in which spherical silica seeds are dispersed in an alkaline organic dispersion medium, and a dehydration condensation reaction of the hydrolyzate is performed. A method for producing monodisperse spherical silica, which comprises a main reaction step of adhering the generated fine silica to the surface of the seed to grow particles to increase the diameter.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26308892A JP3330984B2 (en) | 1992-09-04 | 1992-09-04 | Method for producing monodisperse spherical silica |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP26308892A JP3330984B2 (en) | 1992-09-04 | 1992-09-04 | Method for producing monodisperse spherical silica |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH0687608A true JPH0687608A (en) | 1994-03-29 |
JP3330984B2 JP3330984B2 (en) | 2002-10-07 |
Family
ID=17384666
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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JP26308892A Expired - Fee Related JP3330984B2 (en) | 1992-09-04 | 1992-09-04 | Method for producing monodisperse spherical silica |
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JP (1) | JP3330984B2 (en) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001055484A2 (en) * | 2000-01-28 | 2001-08-02 | The Governing Council Of The University Of Toronto | Photonic bandgap materials based on silicon |
JP2002038049A (en) * | 2000-07-28 | 2002-02-06 | Ube Nitto Kasei Co Ltd | Silica based fine particle and its manufacturing method |
WO2004076533A1 (en) * | 2003-02-27 | 2004-09-10 | Ube Nitto Kasei Co., Ltd. | Method for producing polyorganosiloxane particles and for producing silica particles |
US7333264B2 (en) | 2000-01-28 | 2008-02-19 | Sajeev John | Photonic bandgap materials based on silicon |
JP2008239649A (en) * | 2007-03-23 | 2008-10-09 | Sekisui Chem Co Ltd | Thermosetting resin composition and molded article obtained therefrom |
JP2009046590A (en) * | 2007-08-20 | 2009-03-05 | Sekisui Chem Co Ltd | Thermosetting resin composition and manufacturing method therefor |
JP2011202181A (en) * | 2011-07-08 | 2011-10-13 | Ube Nitto Kasei Co Ltd | Method of preparing silica particles |
CN108529636A (en) * | 2018-05-31 | 2018-09-14 | 佛山市高明区爪和新材料科技有限公司 | A kind of preparation method of Aerosil 200 micro mist |
KR20190132640A (en) | 2017-03-30 | 2019-11-28 | 가부시키가이샤 후지미인코퍼레이티드 | Method for producing silica sol |
-
1992
- 1992-09-04 JP JP26308892A patent/JP3330984B2/en not_active Expired - Fee Related
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2001055484A2 (en) * | 2000-01-28 | 2001-08-02 | The Governing Council Of The University Of Toronto | Photonic bandgap materials based on silicon |
WO2001055484A3 (en) * | 2000-01-28 | 2002-04-18 | Univ Toronto | Photonic bandgap materials based on silicon |
US7333264B2 (en) | 2000-01-28 | 2008-02-19 | Sajeev John | Photonic bandgap materials based on silicon |
JP2002038049A (en) * | 2000-07-28 | 2002-02-06 | Ube Nitto Kasei Co Ltd | Silica based fine particle and its manufacturing method |
WO2004076533A1 (en) * | 2003-02-27 | 2004-09-10 | Ube Nitto Kasei Co., Ltd. | Method for producing polyorganosiloxane particles and for producing silica particles |
US7476706B2 (en) | 2003-02-27 | 2009-01-13 | Ube Nitto Kasei Co., Ltd. | Method for producing polyorganosiloxane particles and for producing silica particles |
JP2008239649A (en) * | 2007-03-23 | 2008-10-09 | Sekisui Chem Co Ltd | Thermosetting resin composition and molded article obtained therefrom |
JP2009046590A (en) * | 2007-08-20 | 2009-03-05 | Sekisui Chem Co Ltd | Thermosetting resin composition and manufacturing method therefor |
JP2011202181A (en) * | 2011-07-08 | 2011-10-13 | Ube Nitto Kasei Co Ltd | Method of preparing silica particles |
KR20190132640A (en) | 2017-03-30 | 2019-11-28 | 가부시키가이샤 후지미인코퍼레이티드 | Method for producing silica sol |
CN108529636A (en) * | 2018-05-31 | 2018-09-14 | 佛山市高明区爪和新材料科技有限公司 | A kind of preparation method of Aerosil 200 micro mist |
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