JPH10194721A - Organic group-containing silica fine particle-dispersed sol and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain sol having a high affinity for organic solvents and resins, in which silica fine particles is readily subjected to monodispersion in water by dispersing silica fine particles containing an organic group directly bonded to silicon into water. SOLUTION: In this organic group-containing silica fine particle disperse sol, silica fine particles containing an organic group directly bonded to silicon is dispersed in water. A ratio of molar number (SR) of silicon in which an organic group is directly bonded to a molar number (Sr ) of whole silicon in silica fine particles is preferably 0.001-0.9, especially 0.01-0.7. This method for producing the organic group-containing silica fine particle disperse sol comprises simultaneously adding an acidic silicic acid solution and a hydrolyzate of an organic silicon compound represented by the formula Rn R'm SiX4-(n+m) [R and R' are each a 1-10C nonsubstituted or substituted hydrocarbon group; X is a 1-4C alkoxy group, silanol group, a halogen or hydrogen; (n) and (m) are each 0-3; (n)+(m)=1-3] into an alkali solution having pH >=10 to produce colloidal fine particles.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sol in which silica fine particles containing organic groups are dispersed in water, and a method for producing the same.

[0002]

2. Description of the Related Art Conventionally, sols of silica and metal oxides are used in various applications, and usually, these sols are water-dispersed sols. When these sols are mixed with an organic solvent or resin, the metal oxide particles themselves are inorganic substances,
The affinity with organic solvents and resins is poor, and aggregates tend to form when mixed, and furthermore, when a mixture with resin is molded,
It is easy for the fine particles to fall off from the molded product, and the use thereof is also limited.

On the other hand, a sol having an affinity to an organic solvent or the like is obtained by hydrolyzing an organosilicon compound, and contains an organic group on the particle surface or inside. Such a silica sol is usually produced using an organic solvent, and thus is a sol using an organic solvent as a dispersion medium. Therefore, in order to use the organic solvent-dispersed sol as a water-dispersed sol, it is necessary to replace the solvent with water or to re-disperse the fine particles after taking it out of the organic solvent. However, since the fine particles contain an organic group, it is difficult to carry out solvent substitution with water or redispersion in water.

[0004]

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, wherein silica fine particles having high affinity to organic solvents and resins and easily monodispersed in water are dispersed in water. It is an object of the present invention to provide a sol and a method for producing the same.

[0005]

SUMMARY OF THE INVENTION The organic group-containing fine silica particle dispersion sol of the present invention is characterized in that fine silica particles containing an organic group directly bonded to silicon are dispersed in water. The silica fine particles are fine particles consisting entirely of silica, or fine particles containing a core consisting of silica, a metal oxide or a composite oxide of these, and an organic group is bonded to a part of silicon in these fine particles. .

The number of moles of total silicon in the silica fine particles (S
The ratio [S _R / (S _T + M)] of the number of moles of silicon (S _R ) to which the organic group is directly bonded to the sum of the number _T of moles and the number of moles of metal element of the metal oxide (M) is 0 It is preferably in the range of .001 to 0.9. However, in the case where the silica fine particle does not contain a nucleus and in the case where the nucleus does not contain a metal oxide, M = 0.

The method for producing an organic group-containing fine silica particle dispersion sol according to the present invention comprises simultaneously adding an acid silicic acid solution and a hydrolyzate of an organic silicon compound represented by [Chemical formula 2] to an alkaline aqueous solution having a pH of 10 or more. It is characterized in that colloidal particles are produced.

[0008]

Embedded image R _n R ′ _m SiX _{4- (n + m) wherein} R and R ′ each represent an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, X represents an alkoxy group having 1 to 4 carbon atoms, Silanol group, halogen, hydrogen, n, m: 0-3, n + m = 1-3]

Further, according to the method for producing an organic group-containing silica fine particle dispersion sol according to the present invention, pH 10, in which fine particles consisting of silica, metal oxide or composite oxide thereof are dispersed.
An acidic silicic acid solution and a hydrolyzate of the organosilicon compound represented by the above [Chemical formula 2] are simultaneously added to the above dispersion liquid, and particle growth is performed with the fine particles as nuclei to form colloidal fine particles. It is characterized by

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the fine silica particles as the dispersoid include solid fine silica particles, a core consisting of silica, metal oxide or composite oxide thereof, and silica formed around the core. And microparticles.

As the metal oxide, Al ₂ O ₃ , T
Examples include iO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , and the like, and as the composite oxide, SiO ₂ -A
l ₂ O ₃ , TiO ₂ -Al ₂ O ₃ , TiO ₂ -Zr
O ₂ , SiO ₂ -TiO ₂ , SiO ₂ -TiO ₂ -Al
₂ O ₃ etc. can be exemplified.

In the present invention, an organic group is directly bonded to part of silicon in the silica fine particles. The content of the organic group in the silica fine particles is, in the case of a pure silica fine particle, the ratio of the number of moles of silicon directly bonded with the organic group (S _R ) to the number of moles of total silicon (S _T ) in the silica fine particles. [S _R /
S _T ] is from 0.001 to 0.9, in particular from 0.01 to 0.
It is preferable to be in the range of 7. In the case of fine particles having nuclei of metal oxides other than silica, the sum of the number of moles of total silicon (S _T ) in the fine particles of silica and the number of moles of metal elements of metal oxides other than silica (M) , The ratio of the number of moles of silicon (S _R ) to which an organic group is directly bonded (S _R / (S _T +
M)] is from 0.001 to 0.9, in particular from 0.01 to 0.
It is preferable to be in the range of 7. When the above ratio is less than 0.001, the effect of containing the organic group is difficult to express, and when it exceeds 0.9, the property of the organic group becomes strong, and the particles are easily aggregated in water.

As the organic group directly bonded to silicon, a C 1-10 substituted or unsubstituted hydrocarbon group is used,
Examples thereof include a hydrocarbon group, a halogenated hydrocarbon group, an epoxyalkyl group, an aminoalkyl group, a methacrylalkyl group and a mercaptoalkyl group. Specifically, methyl group, phenyl group, isobutyl group, vinyl group, trifluoropropyl group, β- (3,4-epoxycyclohexyl) group, γ-glycidoxypropyl group, γ-methacryloxypropyl group, N- (beta) (aminoethyl) gamma-aminopropyl group, gamma-aminopropyl, N-phenyl- gamma-aminopropyl group, gamma-mercaptopropyl group etc. can be mentioned. In addition, such an organic group is introduce | transduced in the silica particle manufacturing process from the organic silicon compound used as a raw material.

Next, the method for producing the organic group-containing fine silica particle dispersion sol according to the present invention will be described. The fine silica particle-dispersed sol can be produced by simultaneously adding the acid silicic acid solution and the hydrolyzate of the organic silicon compound represented by the above [Chemical formula 2] to an aqueous alkaline solution having a pH of 10 or more.

The acidic silicic acid solution is a silicic acid obtained by removing an alkali by treating an aqueous alkali silicate solution with a cation exchange resin, etc.
It is preferable to use an acidic silicic acid solution having a SiO ₂ concentration of about 7% by weight or less.

Specific examples of the organic silicon compound shown in the above-mentioned [Chemical formula 2] include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane and phenyltriethoxysilane. Ethoxysilane, diphenyldiethoxysilane, isobutyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (β-methoxyethoxy) silane, 3,3,3-trifluoropropyltrimethoxysilane, methyl-3,3, 3-trifluoropropyldimethoxysilane, β- (3,4 epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxytripropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysila Γ-glycidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, N- β (aminoethyl) γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ
-Aminopropyltrimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, γ-
Aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, trimethylsilanol, methyltrichlorosilane, methyldichlorosilane, dimethyldichlorosilane, trimethyl Examples include chlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, vinyltrichlorosilane, trimethylbromosilane, diethylsilane and the like.

Since the above organic silicon compounds are poor in hydrophilicity, it is necessary to be able to uniformly mix them in the reaction system by hydrolyzing them in advance. Hydrolysis is
A well-known method can be adopted as a method for hydrolyzing these organic silicon compounds. When a basic metal hydroxide such as an alkali metal hydroxide, ammonia water, an amine or the like is used as a hydrolysis catalyst, it is preferable to use the basic solution after hydrolysis by removing the basic catalyst and using it as an acidic solution. Also,
When a hydrolyzate is prepared using an acidic catalyst such as an organic acid or inorganic acid, it is preferable to remove the acidic catalyst by ion exchange or the like after hydrolysis. In addition, it is desirable to use the hydrolyzate of the obtained organic silicon compound in the form of aqueous solution.

In order to produce a silica fine particle dispersed sol, an aqueous solution of an acid silicic acid solution and an aqueous solution of a hydrolyzate of an organic silicon compound are separately prepared, and this aqueous solution is simultaneously made of an alkaline aqueous solution of pH 10 or more at a predetermined ratio. Add slowly into the reaction mother liquor with stirring. Alternatively, prepare a mixed aqueous solution of an acid silicic acid solution and a hydrolyzate of an organosilicon compound,
This mixed aqueous solution can also be added to the aqueous alkali solution.

Furthermore, an aqueous solution obtained by removing an alkali after hydrolyzing an organosilicon compound with an aqueous solution of alkali silicate or an aqueous solution obtained by hydrolyzing an organosilicon compound with an acidic silicic acid solution is added to the above aqueous alkali solution. Thus, an organic group-containing fine silica particle dispersion sol can also be produced.

Number of moles of silicon in the acidic silicic acid solution (S _K )
Wherein the sum of the number of moles of silicon organic group is directly bonded (S _R), the number of moles of silicon organic group is directly bonded ratio (S _{R) [S R / (S K + S} R) ] and, It is preferable to be in the range of 0.01 to 0.9.

Although the pH value of the reaction mother liquor changes simultaneously with the addition of these aqueous solutions, in the present invention, an operation to control the pH value to a predetermined range is not particularly required. The reaction mother liquor is
Finally, the pH value is determined by the kind of the acidic silicic acid solution and the organosilicon compound and the mixing ratio thereof.

In the method of producing an organic group-containing fine silica particle dispersion sol of the present invention, a sol in which fine particles of silica, metal oxide or composite oxide thereof are dispersed in the aqueous alkali solution can also be used. This method is a method of growing particles to predetermined particle sizes using these inorganic oxide fine particles as seed particles, and organic group-containing silica fine particles having an inorganic oxide fine particle as a core can be obtained.

There are no particular restrictions on the inorganic oxide as seed particles, and SiO ₂ , Al ₂ O ₃ , TiO ₂ or Z
Fine particles of inorganic oxides such as rO ₂ or complex oxides thereof are used, and these sols can usually be used. When SiO ₂ is used as the seed particles of the present invention, the sol obtained by the production method of the present invention may be used as a seed particle dispersion.

An aqueous solution of the above compound is added to the inorganic oxide fine particle dispersion adjusted to pH 10 or more while stirring. Also in this case, the pH control of the dispersion is not performed and left to the end. As described above, when the organic group-containing silica fine particle is grown with the inorganic oxide fine particle as a nucleus, the particle diameter control of the grown particle is easy, and it is possible to obtain the uniform particle size.

When the organic group introduced into the silica fine particles is made reactive, it is possible to react the organic group with a desired compound to modify the surface of the particles.

The organic group-containing silica fine particles obtained by the above method become porous because they contain an organic group in the skeleton of silica.

When concentrating the organic group-containing silica fine particle dispersion sol of the present invention, it is more stable to remove some of the alkali metal ions, alkaline earth metal ions, ammonium ions, etc. in the sol and then concentrate it. Concentrated sol is obtained. As a removal method, a known method such as ultrafiltration can be adopted.

Also, the sol of the present invention can be organolized by solvent substitution with an organic solvent such as alcohol, glycol or cellosolve. The method of solvent substitution adopts a known method such as ultrafiltration.

[0029]

EXAMPLES Examples of the present invention will be shown below.

The diluted Example 1 SiO ₂ concentration of 24.0 wt%, the sodium silicate aqueous solution of SiO ₂ / Na ₂ O molar ratio 3.1 with pure water, SiO ₂
A dilute sodium silicate aqueous solution having a concentration of 5.2% by weight was prepared. This aqueous solution was subjected to a hydrogen cation exchange resin layer (Mitsubishi Chemical Corporation)
, Manufactured by Diaion SK-1B), and passed through an ion exchange column filled with SiO _{2 at a} concentration of 5.0% by weight, pH 2.
An acidic silicic acid solution of 7 was prepared. Moreover, the Na ₂ O concentration is 0.
It was 1% by weight or less.

967.5 g of a 0.65% by weight aqueous solution of sodium hydroxide 32.5 g of methyltrimethoxysilane
The mixture was stirred at room temperature for 1 hour to obtain an aqueous solution of 1.6% by weight of methyltrimethoxysilane hydrolyzate as CH ₃ SiO _3/2 . The aqueous solution was passed through the above ion exchange column to prepare an acidic aqueous solution. The concentration of CH ₃ SiO _3/2 in the obtained acidic aqueous solution is 1.5% by weight, and the pH is 3.5
Met. In addition, the Na ₂ O concentration was 0.1% by weight or less.

A mixture of 20 g of silica sol having an average particle diameter of 12 nm and a SiO ₂ concentration of 30% by weight and 380 g of pure water was adjusted to pH 12 by adding a 5% by weight sodium hydroxide aqueous solution and heated to 80 ° C. In this reaction mother liquor, SiO ₂
The above acidic silicic acid 90 diluted with pure water to a concentration of 1.5% by weight
0 g and 900 g of the above acidic aqueous solution were simultaneously added over 10 hours. Meanwhile, the temperature of the reaction solution was maintained at 80 ° C. After completion of the addition, the reaction solution was cooled to room temperature to obtain a sol containing fine particles of a methyl group-containing silica fine particle.

The specific surface area S (m ² / g) and the average particle diameter Dp (nm) of the silica fine particles dispersed in the sol are shown in Table 1 together with the pH of the reaction mother liquor. The specific surface area is determined by the titration method [Analytical Chemistry Vol. 28, No. 12 (1956)
The average particle size was measured by dynamic light scattering.

Further, the ratio of silicon to which organic groups are directly bonded in all silicon is determined by the following method. The sol is vacuum dried overnight at 100 ° C., and about 5 g of a powder sample obtained by completely removing volatile components such as water is precisely weighed, dispersed in 250 ml of 0.05 N aqueous NaOH solution, and stirred at room temperature for 10 hours Continue.
As a result, all unreacted hydrolyzable groups in the powder sample are hydrolyzed and extracted into water of the dispersion medium. The powder sample in the dispersion was separated by ultracentrifugation and repeatedly washed with water, and then the total carbon content of the powder sample dried at 200 ° C. for 5 hours was measured by elemental analysis, and the organic group used as the raw material From the average carbon number, the number of moles of silicon directly bonded to the organic group was determined, and the ratio to the number of moles of total silicon was calculated.

Example 2 59.2 g of vinyltrimethoxysilane was mixed with 940.8 g of a 1.3 wt% aqueous solution of sodium hydroxide, and 1 at room temperature.
Stirring time gave an aqueous solution of 3.2% by weight of vinyltrimethoxysilane hydrolyzate as CH ₂ CHSiO _3/2 . This aqueous solution was passed through the ion exchange column used in Example 1 to prepare an acidic aqueous solution. The CH ₂ CHSiO _3/2 concentration in the obtained acidic aqueous solution was 3.0% by weight, and the pH was 3.7. In addition, the Na ₂ O concentration was 0.1% by weight or less.

In place of the acidic aqueous solution obtained by hydrolyzing and ion-exchange methyltrimethoxysilane of Example 1, except that the acidic aqueous solution obtained by hydrolyzing and ion-exchanging the above vinyltrimethoxysilane was used. In the same manner as in Example 1, a sol containing fine particles of vinyl group-containing silica particles was obtained.

EXAMPLE 3 32.5 g of methyltrimethoxysilane and 1967.5 g of a dilute aqueous solution of sodium silicate having a concentration of SiO ₂ 0.8 wt% by diluting the aqueous solution of sodium silicate of Example 1 with pure water were mixed. . The mixture solution is stirred at room temperature for 1 hour, CH ₃ S
As iO _2/3 -SiO ₂ was obtained 1.6% by weight aqueous solution. This aqueous solution was passed through the ion exchange column used in Example 1 to prepare an acidic aqueous solution. The CH ₃ SiO _2/3 -SiO ₂ concentration in the obtained acidic aqueous solution is 1.5% by weight,
The pH was 2.9. In addition, the Na ₂ O concentration was 0.1% by weight or less.

In the same manner as in Example 1, except that 1800 g of the above acidic aqueous solution was used instead of the acidic aqueous solution obtained by hydrolyzing and ion-exchange the acid silicic acid solution of Example 1 with methyltrimethoxysilane, methyl A group-containing silica fine particle dispersed sol was obtained.

EXAMPLE 4 0.65% by Weight of 26.0 g of Dimethyldimethoxysilane
The solution was mixed with 974.0 g of an aqueous solution of sodium hydroxide and stirred at room temperature for 1 hour to obtain an aqueous solution of dimethyldimethoxysilane hydrolyzate of 1.6% by weight as (CH ₃ ) ₂ SiO ₂ . This aqueous solution was passed through the ion exchange column used in Example 1 to prepare an acidic aqueous solution. The (CH ₃ ) ₂ SiO concentration in the obtained acidic aqueous solution was 1.5% by weight, and the pH was 3.3. In addition, the Na ₂ O concentration was 0.1% by weight or less.

In place of the acidic aqueous solution obtained by hydrolyzing and ion-exchange methyltrimethoxysilane of Example 1, except that the acidic aqueous solution obtained by hydrolyzing and ion-exchanged the above dimethyldimethoxysilane was used. In the same manner as in Example 1, a methyl group-containing fine silica particle dispersion sol was obtained.

EXAMPLE 5 The procedure of Example 1 was repeated except that the reaction mother liquor of Example 1 was replaced with 400 g of a 11.5 aqueous solution of sodium hydroxide.
A methyl group-containing fine silica particle dispersion sol was obtained.

EXAMPLE 6 Instead of the reaction mother liquor of Example 1, an average particle diameter of 300 nm, S
30 g of silica sol with an iO ₂ concentration of 20% by weight and pure water 370
The reaction mother liquor adjusted to pH 11.5 by adding a 5 wt% aqueous sodium hydroxide solution to a mixture of g and using methyl group-containing in the same manner as Example 1 except that 100 g of the acidic aqueous solution to be added was used Silica fine particle dispersed sol was obtained.

EXAMPLE 7 Instead of the reaction mother liquor of Example 1, an average particle size of 60 nm, Ti
60 g of titania sol at 10 wt% O ₂ concentration and 340 g of pure water
The reaction mother liquor is adjusted to pH 11 by adding a 5 wt% aqueous sodium hydroxide solution to a mixture of g, the temperature of the reaction mother liquor is brought to 60 ° C., and 100 g each of the amount of acidic silicic acid solution and acidic aqueous solution to be added A methyl group-containing fine silica particle dispersed sol containing titanium oxide as a nucleus was obtained in the same manner as in Example 1 except for the above.

[0044]

TABLE 1 Reaction mother liquor S pH of _R U B A de grains terminal _{S T + S R Dp S S} × Dp S R (nm) (m 2 / g) S T + M Example 1 12 0.47 24 500 12000 0.38 Example 2 12 0.60 28 620 17360 0.51 Example 3 12 0.48 24 470 11280 0.37 Example 4 12 0.45 26 750 19500 0.36 Example 5 11.5 0.47 9 1020 9180 0.47 Example 6 11.5 0.09 450 10 4500 0.06 Example 7 11 0.47 67 110 7370 0.18

[0045]

[Effects of the Invention] The organic group-containing fine silica particle dispersion sol according to claims 1 to 4 has organic groups on the inside and on the surface of the dispersed fine particles, so that the affinity with organic solvents, organic substances and resins is obtained. Is high. In addition, the specific surface area of the dispersed particles is large, and the particles have many pores inside. Therefore, besides the application as a catalyst, the present invention can be applied to various applications as follows.

(1) Since the silica fine particles contain an organic group, when dispersed as a filler in an organic substance or resin, aggregation in the paint is less likely to occur, and when it is further incorporated into a film for a magnetic tape Also, it is difficult for aggregation and dropout to occur.

(2) It is porous and has a high affinity to organic substances and resins, so it is used as a filler for low refractive index,
It is also possible to fix a dye or pigment in the pores of the silica fine particle and use it as a dye material.

(3) Since the binder strength is large, molded articles of high strength can be obtained if used as binders for various refractories, for example, when used as a binder for the lost wax method for precision casting, the strength is increased. You can get a good type. Moreover, if it uses as a binder of inorganic fibers, such as a ceramic sheet, the inorganic fiber excellent in tensile strength will be obtained.

(4) In particular, since it is stable on the high alkali side, it can also be used as a cement compounding agent or a soil curing agent, and when used as a soil curing agent, gelation of the curing agent depending on the compounding amount It is possible to adjust the speed.

(5) In addition, lowering agents, chromatography fillers, slipperiness improving agents, cosmetic additives, lubricants, thickeners, freshness keeping agents for foodstuffs, etc. used in the process of producing sake and beer Useful for

The organic group-containing fine silica particle dispersion sol according to the third and fourth aspects of the invention can use various metal oxides as nuclei as seed particles, and therefore, uses utilizing the function of the metal oxide It can be used for For example, if a metal oxide having a specific refractive index is used, it can be used as a filler for adjusting the refractive index. Moreover, if the metal oxide which has an ultraviolet-ray shielding function is used, it can be set as the filler for ultraviolet-ray shielding.

The method for producing the organic group-containing fine silica particle dispersion sol according to the fifth and sixth aspects of the present invention, the pH of the reaction solution
Since the control is unnecessary, the operation of producing colloidal particles is easy, and the manufacturing process can be simplified.

Claims (6)

[Claim of claim] An organic group-containing silica fine particle dispersed sol characterized in that silica fine particles containing an organic group directly bonded to silicon are dispersed in water. 2. The ratio (S _R / S _T ) of the number of moles of silicon directly bonded to the organic group (S _R ) to the number of moles of total silicon (S _T ) in the silica fine particles is 0.001. An organic group-containing silica particle-dispersed sol according to claim 1, wherein the sol is in the range of 0.9 to 0.9. 3. The organic group-containing silica fine particle-dispersed sol according to claim 1, wherein the silica fine particles contain a nucleus composed of silica, a metal oxide or a composite oxide of these. 4. The number of moles of silicon directly bonded to the organic group relative to the sum of the number of moles of total silicon (S _T ) in the silica fine particles and the number of moles of metal elements of the metal oxide (M) the ratio of _{R) [S R / (S T + M} ) ] is an organic group containing silica fine particle dispersion sol of claim 3, wherein a is in the range of 0.001 to 0.9. (However, if the nucleus does not contain a metal oxide, then M = 0.) 5. An organic group-containing, characterized in that an acidic silicic acid solution and a hydrolyzate of an organosilicon compound represented by Chemical Formula 1 are simultaneously added to an alkaline aqueous solution having a pH of 10 or more to form colloidal fine particles. Method for producing a silica fine particle dispersed sol Embedded image R _n R ′ _m SiX _{4- (n + m) wherein} R and R ′ each represent an unsubstituted or substituted hydrocarbon group having 1 to 10 carbon atoms, X represents an alkoxy group having 1 to 4 carbon atoms, Silanol group, halogen, hydrogen, n, m: 0-3, n + m = 1-3] 6. Hydrolysis of an acid silicic acid solution and an organosilicon compound represented by the above [Chemical formula 1] in a dispersion having a pH of 10 or more in which fine particles of silica, metal oxide or composite oxide thereof are dispersed. A method of producing an organic group-containing fine silica particle-dispersed sol, comprising the steps of: simultaneously adding substances; and growing particles with the fine particles as cores to form colloidal fine particles.