JPH04243912A - Production of silicate grain - Google Patents

Abstract

PURPOSE:To obtain silicate particles excellent in dispersibility by suspending an aqueous solution containing a metallic compound and a hydrolyzable silicon compound in an incompatible organic liquid using a cellulosic dispersing agent and gelatinizing the resultant suspension. CONSTITUTION:At least one compound (e.g. tetraisopropoxytitanium) of a metal selected from groups I, II, III and IV of the periodic table and a hydrolyzable silicon compound (e.g. tetramethoxytitanium) are dissolved in water. The resultant mixed solution is then suspended in an organic liquid (e.g. toluene) incompatible with the aforementioned mixture solution using a water-insoluble cellulosic ester or cellulosic ether (e.g. ethyl cellulose) insoluble in the above-mentioned organic liquid as a dispersion stabilizer. The obtained suspension is subsequently heated and gelatinized while being stirred and the produced get particles are separated, dried and burned to afford the objective spherical silicate grains having a relatively large grain diameter without aggregation. The aforementioned silicate grains are suitable as a filler, etc., for resins used) in sealing semiconductors.

Description

Detailed Description of the Invention [0001] [Industrial Application Field] The present invention has a spherical shape and a particle size of 0.1 to 10.
The present invention relates to a method for obtaining silicate particles whose main constituents are silicon and metal elements from Groups I to IV of the periodic table, which are free from agglomeration in the range of 0 μm and therefore have good dispersibility. The silicate particles obtained by the present invention are used as fillers for resin sealing of semiconductor devices such as ICs and LSIs, fillers in various fields such as dental repair materials, ceramics, raw materials for glass, catalyst carriers, and the like. [Prior Art] As a method for producing silicate particles whose main constituents are silicon and metal elements belonging to groups I to IV of the periodic table, silica and metal elements belonging to groups I to IV of the periodic table are produced. A method of mixing metal oxides, melting the mixture at a temperature higher than the melting point and cooling it to form a glassy material, and crushing the glassy material to obtain square particles;
A mixed solution containing a low condensate of hydrolyzable organosilicon compounds described in Japanese Patent Publication Nos. 1-38043 and 38044 and a hydrolyzable organic compound of groups I to IV of the periodic table is mixed with the organic compound. A low condensation product of a silicon compound and an organic compound of Groups I to IV of the periodic table are dissolved in an alkaline solvent in which the reaction product is not substantially dissolved, and hydrolysis is carried out to precipitate the reaction product, This is then fired to 0.
Wet methods for obtaining silicate particles of 1-0.53 μm are known. [0003] However, the particles obtained by the above-mentioned melt-grinding method have a rectangular amorphous shape and a wide particle size distribution, and
In the wet method, only fine particles of 0.1 to 0.53 μm can be obtained, and both methods have a problem in that they can only be used for limited purposes. [Problems to be Solved by the Invention] The object of the present invention is to reduce the particle size to 0.
．． To obtain spherical silicate particles whose main constituents are silicon and metal elements of groups I to IV of the periodic table, which have no agglomeration in the range of 1 to 100 μm and therefore have good dispersibility. be. [Means for Solving the Problems] The present inventors have determined that the periodic table I and I
If a mixed solution containing compounds of metals of groups I, III, and IV, a hydrolyzable silicon compound, and water is hydrolyzed and polymerized under specific conditions, spherical silicate particles without agglomeration can be obtained. They discovered this and arrived at the present invention. [0006]The gist of the present invention is that periodic table I,
A mixed solution containing at least one metal compound selected from Groups II, III, and IV, a hydrolyzable silicon compound, and water is suspended in an organic liquid that is substantially incompatible with the mixed solution. A method for producing silicate particles by gelling the silicate particles, the silicate being characterized in that a water-insoluble cellulose ester or cellulose ether soluble in the organic liquid is present as a dispersion stabilizer in the organic liquid. The problem lies in the method of manufacturing the particles. The present invention will be explained in detail below. The silicon compound used in the present invention is selected from hydrolyzable compounds, specifically, alkyl esters of orthosilicic acid such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetraptoxysilane, and condensates thereof. is a typical compound. In addition, alkoxyalkylsilanes such as trimethoxymethylsilane, dimethoxydimethylsilane, triethoxyethylsilane, diethoxydiethylsilane, and condensates thereof may be used. [0008] Another raw material, Periodic Table I
The compound of the ~IV group metal can be selected from a wide range, and those known for use in this type of reaction can be used, but they can form a homogeneous aqueous solution with the hydrolyzable silicon compound during the reaction. selected from compounds. A small amount of a co-solvent such as alcohol can be used if necessary to form a homogeneous aqueous solution. Preferably, the general formula M1 (OR'), M
2 (OR')2 , M3 (OR')3 , M4 (
OR') 4, (where R' is an alkyl group) metal alkoxide compound or one or two alkoxide groups (OR') in the above general formula are substituted with a carboxyl group or a β-dicarbonyl group Examples include compounds. Here, M1 is a metal of group I, M2 is a metal of group II, M3 is a metal of group III, and M4 is a metal of group IV, specifically, for example, lithium, sodium, potassium, magnesium, calcium, Strontium, barium, aluminium, titanium, zirconium, germanium, hafnium, tin or lead are preferably used. [0010] The organic liquid used as a dispersion medium is a mixed solution containing at least one metal compound of Groups I, II, III and IV of the periodic table, a hydrolyzable silicon compound, and water. Any substance may be used as long as it is substantially incompatible with the hydrocarbon, but hydrocarbons or halogenated aromatic hydrocarbons are usually used. The hydrocarbons are preferably aromatic hydrocarbons, alicyclic hydrocarbons, or aliphatic hydrocarbons having 6 to 10 carbon atoms, and the halogenated aromatic hydrocarbons are preferably chlorinated benzenes. Particularly suitable organic solvents are benzene, toluene, xylene, cyclohexane, methylcyclohexane, cyclooctane, decalin, n-hexane, n-heptane, n-octane, n-decane, chlorobenzene, dichlorobenzene, cymene, cumene, etc. be. In the method of the present invention, periodic table I, II, II
A raw material solution is prepared by mixing at least one metal compound of Groups I and IV, a hydrolyzable silicon compound, and water. At this time, the metal compound, the hydrolyzable organosilicon compound, and water may not form a homogeneous solution and phase separation may occur, but in such cases, a homogeneous solution is obtained by adding a solvent such as alcohol. This homogeneous solution is used as a raw material solution. Note that a catalyst can also be added in order to shorten the time required for gelation in the subsequent step. As the catalyst, acidic catalysts such as hydrochloric acid, nitric acid, sulfuric acid, acetic acid, oxalic acid, and formic acid, and basic catalysts such as ammonia, amine, and caustic alkali can be used. Next, the raw material solution prepared as described above is mixed with an organic liquid serving as a dispersion medium that is substantially incompatible with the raw material solution to form an emulsion in which the raw material solution is dispersed as suspended particles. , followed by gelation of the suspended particles to produce gel particles. At this time, the volume of the dispersion medium may be sufficient to form an emulsion in which the raw material solution is dispersed as suspended particles, and is usually at least the same amount as the raw material solution. Note that a dispersion stabilizer is added to increase the stability of the emulsion. As the dispersion stabilizer, cellulose ester or cellulose ether is used, which is insoluble in the raw material solution and soluble in the organic liquid that is the dispersion medium. Specifically, cellulose acetate butyrate,
Oil-soluble cellulose esters or ethers such as ethylcellulose and ethylhydroxyethylcellulose can be mentioned. [0014] Furthermore, there are no particular limitations on the mixing method;
Methods such as extruding the raw material solution into an organic liquid through an impeller-type rotary stirrer, an emulsifier for emulsion polymerization, a nozzle or a filter having fine holes, etc. can be used. Among these methods, the method using an impeller-type rotary stirrer or the method of extruding the raw material solution into the organic liquid through a nozzle or filter with fine holes is usually used.
The method using an emulsifying machine for emulsion polymerization is suitable for producing fine particles of 50 μm or less. In addition, when producing fine particles of 50 μm or less, the raw material solution and an organic liquid that is substantially incompatible with the raw material solution are introduced into a continuous mixing and dispersing device, and 0.1 k
A continuous method is preferred in which the mixture is mixed under conditions of strong stirring power of W/m3 or more, preferably 0.2 to 2000 kW/m3, and residence time in the suspension step of 10 minutes or less, preferably 0.1 to 5 minutes. At this time, the power required for stirring is 0.1kW/m3
If it is smaller than this, it is not preferable because mixing will not be done sufficiently and a non-uniform emulsion will likely result.If the residence time in the suspension step is longer than 10 minutes, gelation of the raw material solution that has been formed into suspension droplets will begin. This is not preferable because some gel particles may be crushed or aggregated. Here, the continuous mixing and dispersing device refers to a continuous mixing vessel, such as a pipeline mixer, which is capable of finely and homogeneously mixing a medium and a dispersoid by a strong shearing force generated in a homogeneous micro gap. [0016] After the suspension step, if necessary, the reaction solution is allowed to stand as it is, or is allowed to stand under heating, or is left to stand with gentle stirring to promote the formation of a gel. The generated gel particles can be separated from the reaction solution by decantation, filtration, etc., and the dispersion stabilizer attached to the particle surface can be dissolved and washed with an organic solvent, then dried, or left as is.
Silicate particles are obtained by heating to about 00 to 400°C to burn and decompose the dispersion stabilizer. The silicate particles are obtained as spherical particles with a large specific surface area without agglomeration, and can be used as fillers or catalyst supports in various fields as they are, but are usually calcined at a temperature of 1000°C or higher to become dense. become Even when calcined, no agglomeration occurs and spherical silicate can be obtained. [Examples] The present invention will be specifically explained below with reference to Examples, but the present invention is not limited to the following Examples unless the gist thereof is exceeded. The power required for stirring and the residence time in the suspension step in the present invention were determined as follows. (1) Power required for stirring per unit volume The power required for stirring can be determined from the following equation. p=Np ・ρ/gc ・n3 ・d5 p:
Power required for stirring [kg・m/sec] Np:
Constant determined by the shape of the stirring blade ρ: Density of the liquid [kg/m3] gc: Gravity conversion coefficient [kg・m/kg・sec2] n: Stirring speed [l/sec2] d: Blade length of the stirring blade [m] The power required for stirring per unit volume is obtained by dividing p obtained from the above formula by the internal volume v of the stirrer. P=p/v/101.972 P: Required stirring power per unit volume [kW
/m3]p: Required stirring power [kg・m/s
ec]v: Stirrer internal volume [m3] However, 1kW=101.972kg・m/sec 0019
] (2) Residence time in the suspension step T=v/m v: Stirrer internal volume [m3] m:
The flow rate at which the liquid to be stirred is fed into the stirrer [m3/mi
[0020] Example 1 1.8 g of ethyl cellulose containing 49% of ethoxy groups based on the total weight as a dispersion stabilizer was added to 429 g of p-cymene (p-isopropyltoluene) and heated at 60° C. for 30 minutes to form ethyl cellulose. A sufficiently dissolved solution was put into a flask and kept in a constant temperature bath at 60° C. while stirring with an anchor-type stirring blade (300 rpm) to serve as a dispersion medium. Separately, 34.1 g of tetramethoxysilane pre-cooled to 5°C
To a mixed solution of 8.4 g of titanium, tetraisopropoxy titanium, and 38.9 g of methanol, 18.5 g of a 1.4 wt% acetic acid aqueous solution previously cooled to 5°C was added dropwise over 17 minutes with stirring, and then held at 5°C for 2 hours. A transparent homogeneous raw material solution was obtained. The raw material solution was added to the dispersion medium and kept at 60° C. for 30 minutes in a constant temperature bath while stirring at 300 rpm to perform gelation, thereby obtaining a gel particle dispersion slurry. Spherical gel particles with no agglomeration were produced in the gel particle dispersion slurry. Next, after separating the gel particles by decantation, the gel particles were heated at 200°C.
The powder was dried for 24 hours and then calcined in air at 1000°C for 2 hours to obtain silicate particles. The silicate particles were spherical with no agglomeration and had an average particle size of 52 μm. Examples 2 to 4, Comparative Examples 1 and 2 As a dispersion stabilizer, 97 g of ethylcellulose containing 49% of ethoxy groups based on the total weight was added to 23.19 kg of p-cymene (p-isopropyltoluene) at 60°C. A solution in which ethyl cellulose was sufficiently dissolved by heating for 15 minutes was used as a dispersion medium. Separately, tetramethoxysilane 1 pre-cooled to 5°C
A mixed solution of 12 g of acetic acid and 837 g of distilled water, previously cooled to 5°C, was added dropwise to a mixed solution of 562 g of titanium, 387 g of tetraisopropoxytitanium, and 1782 g of methanol under stirring over 17 minutes, and then kept at 5°C for 2 hours to make it transparent. A uniform raw material solution was obtained. Next, the amount of the dispersion medium is 4 to 1 of the raw material solution.
．． 5 into a pipeline homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) and mixed under the conditions of stirring power and residence time listed in Table 1 to turn the raw material solution into a suspension. An emulsion was obtained which was dispersed as droplets. This emulsion was further heated at 60° C. for 30 minutes to complete gelation by hydrolysis and polymerization of tetramethoxysilane to obtain a gel particle-dispersed slurry. Next, the gel particles were separated by decantation, washed with acetone, dried at 200°C for 24 hours, and further calcined in air at 1000°C for 2 hours to obtain silicate particles. Table 1 shows the shape, agglomeration state, and average particle size of the silicate particles. [Table 1] Required stirring power Residence time For silicate particles For spherical silicate particles
(kW/m3) (minutes)
Dispersion and aggregation state Average particle size (μm) Comparative example 1
210 11
With aggregation - Comparative Example 2
0.05 0.2 Coarse aggregation - Example 2
0.2 0.5 No agglomeration
41.8 μm Example 3 50
0.2 No agglomeration
14.7 μm Example 4 740
0.2 No agglomeration
1.6μm Example 5 1180
0.2 No agglomeration
0.8 μm [Effect of the invention] According to the method of the present invention, the particle size is 0.1 to 10 μm.
It is possible to obtain a spherical silicate having a relatively large particle size of 0 μm and having good dispersibility and mainly consisting of silicon and metal.

Claims (2)

[Claims] 1. A mixed solution containing at least one metal compound selected from Groups I, II, III and IV of the Periodic Table, a hydrolyzable silicon compound, and water,
A method for producing silicate particles by suspending the particles in an organic liquid that is substantially incompatible with the mixed solution and then gelling the water-insoluble cellulose ester, which is soluble in the organic liquid, in the organic liquid. Alternatively, a method for producing silicate particles, characterized in that cellulose ether is present as a dispersion stabilizer. 2. A mixed solution containing at least one metal compound selected from Groups I, II, III, and IV of the Periodic Table, a hydrolyzable silicon compound, and water, and a solution substantially compatible with the mixed solution. A claim characterized in that an insoluble organic liquid is supplied to a continuous mixing and dispersing device and suspended under conditions of a required stirring power of 0.1 kW/m3 or more and a residence time in the suspension step of 10 minutes or less. Item 1. A method for continuously producing silicate particles according to item 1.