JP3330984B2 - Method for producing monodisperse spherical silica - Google Patents
Method for producing monodisperse spherical silicaInfo
- Publication number
- JP3330984B2 JP3330984B2 JP26308892A JP26308892A JP3330984B2 JP 3330984 B2 JP3330984 B2 JP 3330984B2 JP 26308892 A JP26308892 A JP 26308892A JP 26308892 A JP26308892 A JP 26308892A JP 3330984 B2 JP3330984 B2 JP 3330984B2
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- Prior art keywords
- solution
- reaction
- silica
- alkoxysilane
- particles
- Prior art date
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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 particles consisting of spherical particles with a particle size of submicron to micron units and extremely narrow particle size distribution are used as spacers for liquid crystal display devices, various fillers, fillers for chromatography, precision It is attracting attention as a material suitable for use in abrasives and the like. In the present invention, in order to obtain such silica particles, a method of growing spherical silica seeds to increase the diameter, particularly, hydrolyzing and dehydrating polycondensation of alkoxysilane to have an average particle diameter of 0.1 to 10 μm
To obtain a monodispersed spherical silica of In the present specification, the monodispersion means that the coefficient of variation of the particle size distribution (percentage value of the standard deviation of the particle diameter based on the average particle diameter) 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 monodispersed spherical silica of about 0.05 to 2 .mu.m by hydrolysis and dehydration condensation polymerization of alkoxysilane is known (W. Stover, Journal).
ofColloid & Interface Sc
i. , 26, 62-69, 1968). This reaction is described as follows using tetraethoxysilane as an example. First, a necessary amount of water and pH of ammonia water are added to a raw material solution obtained by diluting tetraethoxysilane with ethyl alcohol.
When a mixed solution is prepared by adding an adjusting agent and stirring, ethoxysilane in the raw material solution is hydrolyzed by water in the added solution into silicic acid and ethyl alcohol as shown in the following chemical formula 1. Then, when the concentration of the silicic acid in the solution reaches the supersaturation point, as shown in the chemical formula 2, extremely fine silica is generated by the dehydration-condensation polymerization. In this case, spherical silica having a relatively uniform particle size is obtained.
【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。[0005] During this time, the mixture changes from a transparent state to a translucent state, and the degree of transparency decreases and the degree of cloudiness increases. Very fine silica has already been generated in the state of being visually transparent to slightly translucent, and it becomes opaque or cloudy as it aggregates and increases in diameter. A large number of large-diameter silica and small-diameter silica or fine-particle silica are mixed to some extent, and it is extremely difficult to directly obtain a large-diameter monodisperse spherical silica of 10 μm from this mixture.
【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 the spherical silica obtained by fractionating the liquid in a separately prepared dispersing medium is used as a reaction liquid, and the alkoxysilane is mixed with an alcohol or the like. The raw material liquid dissolved in the organic solvent is continuously dropped, and water and additional liquids such as a pH adjusting solution necessary for the reaction are continuously dropped, and the reaction solution shown in the above formulas (1) and (2) is newly added to the reaction solution. The fine silica produced in the above is aggregated into a seed to further increase the diameter. This is also known (Japanese Unexamined Patent Publication No. Sho 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 growing method, generally, the above-mentioned alkoxysilane raw material liquid is supplied continuously and dropwise to a reaction liquid in a tank in which seeds are dispersed, and water necessary for the reaction and pH control for pH adjustment are generally used. The additive liquid is supplied dropwise from a separate supply source, and the hydrolysis reaction of the raw material alkoxysilane and the generation of silica by the subsequent dehydration-condensation polymerization proceed in parallel in one tank containing the reaction liquid. . According to this method, it is possible to increase the diameter of the seed, but at the same time, it is easy to newly generate fine silica and small-diameter spherical silica that do not contribute to the growth of the seed in the reaction solution, and the growth of the seed is also difficult. In fact, it is difficult to stably produce spherical silica having a desired particle size with a sharp 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。SUMMARY OF THE INVENTION An object of the present invention is to eliminate the above-mentioned disadvantages of the conventional production technology, and to provide 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。As a result of repeated studies to achieve the above object, the above-mentioned drawbacks of the conventional seed growth method are that a small amount of alkoxysilane is contained in the reaction solution. In order to hydrolyze the alkoxysilane in the reaction solution, the reaction solution was stirred by a normal stirring operation, and the raw material solution and the added solution for adjusting the pH were separately and sequentially supplied. It was presumed that this was because it was difficult to mix the solution and each additive solution evenly throughout the large-volume reaction solution.
According to experiments, when the conventional seed growth method is used, the state of the hydrolysis reaction in the reaction solution in the above-mentioned tank and the formation of new silica due to the subsequent polycondensation become locally inhomogeneous. It was confirmed that the particle growth due to the aggregate of the fine silica particles thus obtained 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 present inventors have studied the means for solving the above problems, and as a result, have found that the following method is effective, and reached the present invention. That is, the solution principle of the present invention is to minimize the simultaneous hydrolysis of the added alkoxysilane and the growth of the seed in a single reaction solution,
The purpose is to allow them to be performed separately in different places.
By dividing these two processes into separate processes without coexisting in one tank, the desired monodispersed spherical silica was easily and stably obtained.
【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、
ｐＨを所定の値１１〜１４に調整したアルカリ水溶液お
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、ｐＨを所定の値１１〜１４に調整したアルカリ水溶
液および有機溶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 follows:
As described in the claims, alkoxysilane,
Preliminary treatment in which an alkaline aqueous solution and an organic solvent whose pH has been adjusted to a predetermined value of 11 to 14 are continuously poured into a preliminary reaction tank and mixed to obtain a liquid containing silicic acid, which is a hydrolyzate of alkoxysilane. The step and the solution containing the hydrolyzate are continuously placed in a main reaction tank containing a reaction solution obtained by dispersing spherical silica seeds in an alkaline aqueous solution and an organic solvent whose pH has been adjusted to a predetermined value of 11 to 14. And the main reaction step of growing fine particles produced by the dehydration condensation reaction of the hydrolyzate and adhering to the surface of the seed to grow particles and increase the diameter of the monodispersed spherical silica. is there.
【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 structure of the method of the present invention will be described in order as follows. Pretreatment step: In the pretreatment step, the alkoxysilane in the organic solvent is hydrolyzed using water and alkali adjustment water to prepare a liquid containing silicic acid. The alkoxysilane, the alkali adjustment water and the organic solvent may be those conventionally used for the production of silica particles using the hydrolysis / condensation reaction of alkoxysilane. As the alkoxysilane, tetraethoxysilane (ethyl silicate) and tetramethoxysilane (methyl silicate) are suitable and easily available. Preferable examples of the organic solvent include ethanol, methanol and propanol. As the alkali source, ammonia or caustic soda is preferably used.
【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 good 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, inconvenience is caused.) In the polycondensation for the hydrolysis of the alkoxysilane and the formation of silica in the main reaction step. To adjust the reaction rate and prevent the silica particles from dissolving, add water to adjust the pH.
Used as alkali adjusted water of Nos. 11 to 14. The water in the alkali adjusted water has a water concentration of 1 to 50 in the pretreatment reaction solution.
It is adjusted to be 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 the alkali adjusted water is also dissolved in an organic solvent in advance, but the concentration in the solvent is 12.5 vol.
l. % To 50 vol. % Is preferable. If the concentration of the alkali adjustment water in the solvent is too high, the hydrolysis will be too large, and if it is too low, the hydrolysis rate will be low and unreacted alkoxysilane will remain. Diameter control becomes difficult.
【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。At the time of the pretreatment, an alkali adjusted water adjusted to a predetermined pH value is dissolved in an organic solvent, the temperature of the solution is adjusted to the temperature set in the pretreatment tank, and the organic solvent is adjusted so that the alkoxysilane also has a predetermined concentration. , And the temperature of the liquid is adjusted in the same manner. Next, these liquids are continuously poured into the pretreatment tank and mixed with stirring. In the tank, the hydrolysis reaction of Formula 1 occurs mainly and generates heat. However, since the calorific value is small, the temperature of the mixed reaction solution can be easily adjusted. The reaction temperature is appropriately determined in consideration of the boiling point and the 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 need to match the temperature of the main reaction, and can be different to improve the particle size distribution and manufacturing efficiency of the final product.
【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 rate at which the liquid after the pretreatment step is fed into the main reaction tank depends on the concentration of the silica seed particles in the main reaction tank and the amount of the liquid. If the rate is too high, self-nucleation tends to occur. In general, if the rate is too low, the particle growth is retarded.
It is preferable to be 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
リ性有機溶媒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 previously stored in the main reaction tank preferably has a particle size of 0.5 μm or less and a coefficient of variation of the particle size of 15% or less. Seed particles must be dispersed in an alkaline organic solvent medium, the particle size distribution to generate a self nuclei fine silica produced in the reaction tank number density thereof is low are independent without gathering coalesce to seed When the number concentration is high, the grown spherical silica particles aggregate and become coarse, so that 1 × 10 10 particles / l to 1 × 10 15
/ L, preferably 1 × 10 13 / l to 1 × 10 14
ケ / l. As the organic dispersion medium for dispersing the seed particles, the same solvent as the above-mentioned solvent used in the preliminary treatment step can be used. P of this liquid
H adjusts the pH value using the appropriate alkali source to stabilize the condensation reaction and obtain spherical silica particles having a uniform particle size, and adjusts the pH value of the silicic acid solution supplied through the pretreatment step. 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) From the top of a pre-reaction tank (capacity 10 ml) equipped with a stirring rod having a vertical axis and having a plurality of horizontal blades attached to a vertical axis in order to have a function of preventing liquid from running ahead, a micro tube was formed. An ethanol solution containing 1.6 mol / l of ethoxysilane and a pH of 12.5 by a pump.
Of ammonia water at 25 vol. % Ethanol solution was added at a rate of 0.25 ml / min, stirred and mixed. The pH of this mixture was 11.9, and the temperature of the mixture was 20 ° C. The average residence time of the injection liquid in the tank is 1 minute, during which time the ethoxysilane in the liquid completes the required reaction and reaches a lower part of the preliminary reaction layer as a uniform hydrolysis solution, that is, a silicic acid solution. 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% previously obtained by hydrolysis and polycondensation of alkoxysilane were mixed in an amount of 6 × 10 13 particles / l. An alkaline ethanol solvent 1 containing ammonia so as to have a number concentration.
It is 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。Next, the solution containing silicic acid obtained by the above-mentioned hydrolysis is continuously supplied dropwise from the lower outlet of the preliminary reaction tank to the main reaction tank, and the alkaline organic solution in which the silica seed in the main reaction tank is dispersed is dispersed. The particles were grown from the seed particles 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. As a result, a monodisperse spherical particle having an average particle size of 1.60 μm and a variation coefficient of 4% was obtained. Silica particles could be obtained. In addition, the photograph observation by SEM is JXA JXA
Performed using a Model-840A.
【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 tank (capacity: 20 ml) used in Example 1, propoxysilane was 1.6 m from above with a micro tube pump.
ol / l of an ethanol solution and pH 12.5 aqueous ammonia at 25 vol. % Ethanol solution at a rate of 0.25 ml / min, stirred and mixed.
The pH of the mixture was 11.9, and the temperature of the mixture was 10 ° C. The average residence time of the injection liquid in the tank is 2 minutes, during which time the propoxysilane in the liquid completes the required reaction and reaches a lower part of the preliminary reaction tank as a uniform hydrolysis solution, that is, a silicic acid solution. On the other hand, in the main reaction tank (capacity: 1 liter), monodispersed silica particles having an average particle diameter of 0.343 μm and a coefficient of variation of 9% previously obtained by hydrolysis and polycondensation of alkoxysilane in a 6 × The solution is diluted and dispersed in 100 ml of an alkaline ethanol solvent containing ammonia so as to have a number concentration of 10 13 / 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。Next, the solution containing silicic acid obtained by the above-mentioned hydrolysis is continuously supplied dropwise from the lower outlet of the preliminary reaction tank to the main reaction tank, and the alkaline organic dispersion in which the silica seeds in the main reaction tank are dispersed. The particles were grown from the seed particles by stirring and mixing with a solvent (temperature: 8 ° C.). After 25 hours, the supply of the silicic acid solution was stopped, and the obtained slurry was subjected to solid-liquid separation. The particle diameter was evaluated by SEM photograph observation. The average particle diameter was 2.53 μm, and the coefficient of variation 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 used in Example 1 were mixed with an ethanol dispersion of the same silica seed particles as used in Example 1. Each of the main reaction tanks was directly dropped and supplied, and seed particles were grown under the same conditions as in the example. When the particle size of the obtained slurry product was evaluated in the same manner as before, the average particle size was 0.95 μm, and the shape of the particle size distribution diagram showed a small particle size from the peak centered on the average particle size. , And showed a polydisperse particle distribution with a coefficient of variation of 23.3%. Therefore, after preliminarily hydrolyzing the alkoxysilane in the pretreatment step, adding the liquid containing the hydrolyzate to the main reaction liquid in which the silica seed particles are dispersed to control the growth of the particles makes it possible to form the silica particles. It has been proven 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 embodiment of the present invention has been described above, the embodiment of the present invention is not limited to the above-described embodiment. 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 a liquid obtained by dispersing the silica particles as a seed as the main reaction solution, and further drop the same preliminary reaction solution as before to grow the particles. Thereby, monodispersed spherical silica particles having an arbitrary particle size and suitable for various uses can be easily obtained.
【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 for growing monodispersed spherical silica particles from the silica seed particles of the present invention comprises a pretreatment step of hydrolyzing alkoxysilane and a hydrolyzate obtained in this step in a solvent. By performing a main reaction step in which polycondensation is performed on the surface of the dispersed silica seed particles to grow the particles, the monodispersed spherical silica having an average particle diameter of 0.1 to 10 μm and a variation coefficient of 15% or less is obtained. Since the particles can be obtained easily and efficiently as compared with the conventional method, it is industrially useful.
───────────────────────────────────────────────────── フロントページの続き 審査官 関 美祝 (58)調査した分野(Int.Cl.7，ＤＢ名) C01B 33/113 - 33/193 ＪＩＣＳＴファイル（ＪＯＩＳ)────────────────────────────────────────────────── ─── Continued on the front page Examiner Yoshihisa Seki (58) Field surveyed (Int. Cl. 7 , DB name) C01B 33/113-33/193 JICST file (JOIS)
Claims (1)
〜１４に調整したアルカリ水溶液および有機溶媒を、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、ｐＨを所定の値１
１〜１４に調整したアルカリ水溶液および有機溶媒に球
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. An alkoxysilane having a pH of a predetermined value of 11.
A pretreatment step of continuously pouring and mixing an alkaline aqueous solution and an organic solvent adjusted to ~ 14 into a preliminary reaction tank to form a liquid containing silicic acid which is a hydrolyzate of alkoxysilane; The pH of the liquid containing the substance is adjusted to a predetermined value of 1.
The aqueous solution prepared by dispersing the seeds of spherical silica in an aqueous alkali solution and an organic solvent adjusted to 1 to 14 is continuously supplied into a main reaction tank containing the reaction solution, and the fine particles formed by the dehydration condensation reaction of the hydrolyzate And a main reaction step of growing particles and increasing the diameter by adhering a suitable silica to the surface of the seed.
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 JPH0687608A (en) | 1994-03-29 |
| JP3330984B2 true JP3330984B2 (en) | 2002-10-07 |
Family
ID=17384666
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26308892A Expired - Fee Related JP3330984B2 (en) | 1992-09-04 | 1992-09-04 | Method for producing monodisperse spherical silica |
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| Country | Link |
|---|---|
| JP (1) | JP3330984B2 (en) |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20030156319A1 (en) | 2000-01-28 | 2003-08-21 | Sajeev John | Photonic bandgap materials based on silicon |
| 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 |
| JP4976894B2 (en) * | 2007-03-23 | 2012-07-18 | 積水化学工業株式会社 | Thermosetting resin composition and molded product obtained therefrom |
| JP4976957B2 (en) * | 2007-08-20 | 2012-07-18 | 積水化学工業株式会社 | Thermosetting resin composition and method for producing the same |
| JP2011202181A (en) * | 2011-07-08 | 2011-10-13 | Ube Nitto Kasei Co Ltd | Method of preparing silica particles |
| JP6854683B2 (en) | 2017-03-30 | 2021-04-07 | 株式会社フジミインコーポレーテッド | Manufacturing method of 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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1992
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| Publication number | Publication date |
|---|---|
| JPH0687608A (en) | 1994-03-29 |
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