JP2013241315A - Microparticle group and method for producing microparticle group - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a microparticle group having a small particle diameter, and small fluctuation of the particle diameter.SOLUTION: A microparticle group is composed of a number of microparticles, the particle diameter of the microparticle is in a range of 100-1,000 nm, the sphericity of the microparticle is 10 nm or less and the deviation coefficient of the microparticle's particle diameter is 10.0% or less.

Description

  The present invention relates to a fine particle group composed of fine particles having a particle diameter of 1 μm or less and a method for producing the fine particle group.

  Conventionally, fine particles made of silica have been used as, for example, a sealing filler or a spacer for a liquid crystal cell.

  In Patent Document 1, a silicon alkoxide is added to a dispersion in which silica seed particles are dispersed in a mixed solvent of alcohol and aqueous ammonia to hydrolyze the silica seed particles. A method for producing silica particles is described in which the average particle size of the fine silica particles is 90% or less of the average particle size of the silica seed particles, or the silica seed particles have an average particle size of 2 μm or more.

  In Patent Document 2, after polyorganosiloxane particles are pre-baked at a temperature that is 100 ° C. lower than the decomposition temperature of the organic group contained therein and less than the decomposition temperature of the organic group. And a method for producing silica particles, which is fired at a temperature equal to or higher than the decomposition temperature of the organic group. In Patent Document 2, polyorganosiloxane particles obtained by hydrolyzing and condensing an alkoxysilane compound having a non-hydrolyzable organic group are heat-treated to obtain surface-activated silica particles. A method is described in which the seed particles are grown with tetraalkoxysilane or alkyltrialkoxysilane and then heat-treated as necessary to obtain silica particles of 3 μm or more.

  In Patent Document 3, a preparatory step of preparing a reaction solution by adding a mixed solution of an alkoxysilane having a non-hydrolyzable group and an alcohol to an aqueous solvent, and adding aqueous ammonia to the reaction solution to prepare polyorganosiloxane particles. It was produced by a production method including a precipitation / growth step for depositing and growing, a reaction completion step for adding ammonia water to the reaction solution to complete the reaction of the polyorganosiloxane particles, and a firing step for firing the polyorganosiloxane particles. Fine particles having an average particle size of 7 μm or more are disclosed.

Japanese Patent Laid-Open No. 10-203820 JP 2001-302227 A JP 2009-102189 A

  As described above, Patent Document 1 discloses a method of producing silica fine particles having an average particle diameter of 2 μm or more, Patent Document 2 of 3 μm or more, and Patent Document 3 of 7 μm or more, respectively. The demand for fine particles is increasing.

  Possible applications of fine particles having a particle size smaller than those of Patent Documents 1 to 3 are, for example, applications as spacers for liquid crystal cells having a high response speed, and standards having an average particle size of 1 μm or less, called submicrons. Applications as particles, applications as chemical mechanical polishing (CMP) slurry for polishing silicon wafers, applications as cosmetic materials using structural colors, photonics that control light by arranging fine particles uniformly Application as a material for artificial opal that displays crystals and particles uniformly and expresses structural color, matting agent for paints below the wavelength of light, slippery material for film, light diffusion plate for liquid crystal display panels below the wavelength of light, light There are uses as a material for diffusion films and antiglare films.

  An object of the present invention is to provide a group of fine particles having a smaller particle size and a smaller variation in particle size than conventional ones, and a method for producing the same.

  In order to achieve the above object, the present inventors have conducted extensive research and have arrived at the present invention.

That is, the present invention is a fine particle group consisting of a large number of fine particles,
The particle diameter of the fine particles is in the range of 100 nm to 1000 nm, and the sphericity is 10 nm or less.
The fine particle group is characterized in that the deviation coefficient of the particle diameter of the fine particles is 10.0% or less.

  The raw material of the fine particles can be alkoxysilane.

  The fine particles may be manufactured using a sol-gel method.

  The ammonia concentration at the time of hydrolysis and dehydration condensation can be 1 wt% or more and 28 wt% or less.

  The fine particle group includes an alkoxysilane compound consisting of only a hydrolyzable group alone or an alkoxysilane compound consisting only of a hydrolyzable group in an aqueous solution containing ammonia or a mixed solution of water and alcohol and / or ketone. A mixture with an alkoxysilane compound having a non-hydrolyzable group can be used as a raw material, and it can be made of fine particles obtained by hydrolysis and dehydration condensation.

  The fine particle group expresses a structural color when the fine particles are closely packed, and can be used as a raw material for cosmetics.

Further, as an invention of a method for producing a fine particle group, the fine particle group is composed of a large number of fine particles having a particle diameter in a range of 100 nm to 1,000 nm and a sphericity of 10 nm or less. A method for producing a fine particle group of 0% or less,
The above-mentioned fine particles are obtained using a sol-gel method using alkoxysilane as a raw material.

  The fine particles having a particle diameter in the range of 100 nm to 1000 nm are extremely smaller than the conventional fine particles disclosed in Patent Documents 1 to 3. And since the sphericity of each fine particle is 10 nm or less, the shape of each fine particle becomes a shape close to a true sphere. Furthermore, when the deviation coefficient of the particle diameter of the fine particles is 10.0% or less, the particle diameters of the fine particles constituting the fine particle group are made uniform.

  Here, the display speed of the liquid crystal is determined by the gap of the liquid crystal, that is, the size of the spacer for the liquid crystal cell and the viscosity of the liquid crystal. When the fine particle group of the present invention is used as a spacer for a liquid crystal cell, it is a fine fine particle, its shape is close to a true sphere, and its particle size distribution is very narrow. The gap can be accurately controlled. Thereby, the liquid crystal display element which has the ultra-high-speed response which was not realizable with the microparticles | fine-particles of patent documents 1-3 can be obtained, maintaining high quality.

  In addition, since the fine particles are close to true spheres in the range of 100 nm to 1000 nm and the particle size distribution is narrow, the particle size is less varied and the utility value as submicron standard particles is high.

  In addition, since the deviation coefficient is as low as 10.0% or less, giant particles or extremely fine particles do not exist in the fine particle group. Therefore, when used as a CMP slurry, the risk of damaging the silicon wafer is extremely low, and the entire polished surface of the silicon wafer can be uniformly polished.

  For example, when a group of fine particles is used as a raw material for cosmetics, the particle diameter can be reduced to about ½ of the wavelength of light. Expresses a structural color. Therefore, when the fine particle group is used as a raw material for cosmetics, a cosmetic product having an unprecedented design like a rainbow color can be obtained. Moreover, since the particle diameter can be strictly controlled, its color can be finely adjusted.

  And since the particle diameter is 100 nm or more, the possibility that the fine particles penetrate into the skin is low, and when the raw material of the fine particles is alkoxysilane, it is harmless to the human body. Can increase the sex.

  In addition, if the fine particles constituting the fine particle group are arranged three-dimensionally and uniformly, the refractive index of light inside each fine particle changes, so it can be used as a photonic crystal, as an optical switch or a new laser element. It is valid.

  Further, if the fine particles constituting the fine particle group of the present invention are made of silica, and they are arranged three-dimensionally to obtain a three-dimensional object, and the three-dimensional object is arbitrarily combined and integrally molded, the color at the viewing angle can be obtained. It is possible to produce artificial opals with the same components as natural opals that change.

  Further, the fine particles constituting the fine particle group of the present invention can be used as a material for matting agents for paints, slipperiness imparting materials for films, light diffusion plates for liquid crystals, light diffusion films and antiglare films, It is possible to provide a new function that does not exist in the conventional one.

  According to the present invention, a fine particle group is composed of fine particles having a particle size in the range of 100 nm to 1000 nm and a sphericity of 10 nm or less, and the deviation coefficient of the particle size of the fine particles is 10.0% or less. Therefore, for example, when used for spacers for liquid crystal cells, standard particles, CMP slurries, cosmetics, etc., remarkable effects that cannot be obtained with conventional fine particles can be obtained.

It is an electron micrograph of the fine particle group concerning embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail. It should be noted that the following description of the preferred embodiment is merely illustrative in nature, and is not intended to limit the present invention, its application, or its use.

  The fine particle group of the present invention comprises a large number of fine particles as shown in FIG. The photograph on the right side of FIG. 1 is taken at a magnification larger than that of the photograph on the left side. The length of the straight line on the lower right side in the left photograph is 1.0 μm, and the length of the straight line at the same position in the right photograph is 0.5 μm.

  Each fine particle is an organic silicone particle or a silica particle obtained by firing the same. The particle diameter of each fine particle is set to 100 nm or more and 1000 nm or less. The sphericity of the fine particles is set to 10 nm or less. Furthermore, the deviation coefficient of the particle diameter of the fine particles constituting the fine particle group is set to 10.0% or less.

  The sphericity is a radius difference between the minimum circumscribed sphere and the maximum inscribed sphere with respect to the fine particles observed using an electron microscope. The sphericity is more preferably 8 nm or less, and further preferably 5 nm or less.

  The deviation coefficient of the particle diameter of the fine particles is obtained by observing the fine particle group with an electron microscope, measuring the diameter of 300 fine particles, obtaining a standard deviation, and dividing the standard deviation by the average particle diameter as a percentage. It is a representation. The deviation coefficient is more preferably 6.0% or less, and still more preferably 4.0% or less.

  Next, the manufacturing method of the fine particle group which consists of the said organosilicon particle is demonstrated.

  The method for producing organosilicone particles as fine particles according to the present invention includes a step of producing fine particles by hydrolyzing and dehydrating and condensing an alkoxysilane compound using a sol-gel method, and a step of completing the reaction of the produced fine particles. Is included. Moreover, the manufacturing method of the silica particle as a fine particle concerning this invention includes the process of baking the organosilicone particle obtained at the said process.

  Specifically, first, an aqueous solution containing ammonia is prepared. While stirring this aqueous solution, an alkoxysilane compound consisting solely of a hydrolyzable group is continuously dropped into the aqueous solution at a constant rate, and the alkoxysilane compound is hydrolyzed and dehydrated in the aqueous solution to produce fine particles. Let

  After completion of dropping the alkoxysilane compound, the aqueous solution is continuously stirred to complete the reaction of the fine particles in the aqueous solution.

  In the above method, an aqueous solution containing ammonia is used, but a mixed solution of water and alcohol and / or ketone may be used instead.

  Moreover, you may make it dripping the mixture of the alkoxysilane compound which consists only of a hydrolysable group, and the alkoxysilane compound which has a non-hydrolyzable group into the said aqueous solution and the said mixed solution.

  Examples of the alkoxysilane compound comprising only a hydrolyzable group include tetraalkoxysilane compounds such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane; tetraalkylalkoxysilane compounds such as tetramethylmethoxysilane and tetraethylethoxysilane A tetraacylalkoxysilane such as tetraacetoxysilane; Examples of the alkoxysilane compound having a non-hydrolyzable group include methyltrimethoxysilane, methyltriethoxysilane, methyltriisopropoxysilane, methyltris (methoxyethoxy) silane, ethyltrimethoxysilane, ethyltriethoxysilane, propyltrimethyl. Ethoxysilane, butyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-methacrylic And organotrialkoxysilanes such as loxypropyltrimethoxysilane.

  Among the above compounds, tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane are preferable.

  The raw material alkoxysilane compound may be used alone or as a mixture of two or more. However, when a mixture of compounds having different alkoxy groups is used as a raw material, the particle size distribution of the generated fine particles tends to be widened. Is recognized. For this reason, when using 2 or more types of mixtures as a raw material, it is preferable to set it as the mixture of the alkoxysilane compounds which have the same alkoxy group. Moreover, the raw material alkoxysilane compound may be used as it is, or may be diluted with an organic solvent. At this time, the organic solvent is selected from the following reaction solvents, and it is preferable to select the same alcohol as the alcohol to be eliminated.

  The water used for the reaction needs to be free of unnecessary components such as insoluble matter, ions, and silicon. Therefore, it is preferable to use a material from which impurities have been removed in advance using microfiltration, ion exchange resin, ultraviolet light, RO (reverse osmosis membrane) or the like.

  As the organic solvent used in the reaction, an organic solvent compatible with water, for example, one or a mixture of two or more selected from alcohols, ethers, ketones and the like is used.

  Alcohols include monohydric alcohols such as methyl alcohol, ethyl alcohol, propyl alcohol, and butyl alcohol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, and hexanetriol; ethylene glycol monomethyl ether, ethylene Glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol And monoethers of polyhydric alcohols such as monopropyl ether and propylene glycol monobutyl ether. Examples of ketones include acetone, methyl ethyl ketone, and methyl isoamyl ketone.

  Among the above solvents, alcohol solvents such as methanol, ethanol, isopropanol and butanol are preferable. Furthermore, from the viewpoint of hydrolysis and dehydration condensation reaction, it is more preferable to select the same alcohol as the alcohol to be eliminated.

  The concentration of ammonia used for the reaction is selected in the range of 1 wt% to 28 wt%. More preferably, it is in the range of 3 wt% to 12 wt%. A concentration lower than 1% by weight is not preferable because a non-spherical by-product is produced.

  Fine particles can be obtained in the same way when acids, bases, or organic metals other than ammonia are used as the condensation catalyst, but a catalyst residue or impurities that are difficult to remove after the reaction is produced, so the purification process And a cleaning step is required, which is not preferable.

  When the concentration of ammonia is less than 1% by weight, the shape of the fine particles is hardly spherical and the deviation coefficient is higher than 10.0%, which is not preferable.

  On the other hand, when the ammonia concentration is higher than 28% by weight, the particle diameter of the generated fine particles becomes smaller than 100 nm. When the particle diameter is smaller than 100 nm, it is not preferable in terms of optical characteristics and safety.

  This ammonia is used as an aqueous solution or a mixed solution of water and an organic solvent. It is preferable to use water from which impurities have been removed in advance. Examples of the organic solvent include water-compatible organic solvents such as alcohols, ethers, and ketones. Among these, it is preferable to select from the solvents used in the reaction system.

  The reaction temperature and reaction time for the hydrolysis and dehydration condensation depend on the alkoxysilane compound used as a raw material, the type of solvent, and the like, but are usually in the temperature range of −10 ° C. to 60 ° C. for 1 hour to 24 hours. It is selected within the following range. Completion of the subsequent reaction may be performed at the same temperature as in the previous reaction, or may be performed at a slightly elevated temperature. The time for completing the reaction is selected in the range of 1 hour to 24 hours.

  After completion of the reaction, the produced fine particles are sufficiently washed and then dried. The drying treatment depends on the types of raw materials and solvents and the amount of treatment, but is usually performed at a temperature ranging from room temperature to 100 ° C. for 1 hour to 24 hours under normal pressure or reduced pressure.

  In this way, organosilicone particles as fine particles are obtained. The fine particle group may be composed only of the organic silicone particles, or the fine particle group may be composed of the silica particles obtained by baking the organic silicone particles.

  The temperature and time for firing the organosilicone particles depend on the type, particle size, amount of treatment, etc. of the silicone particles, but are usually 3 hours or more and 24 hours or less in a temperature range of 250 ° C to 1100 ° C. Selected by range.

  This firing treatment step may be performed as a single step or may be performed as a multi-step process of two or more times. However, in order to prevent cracking or chipping of fine particles due to rapid temperature rise, occurrence of cracks, etc. It is desirable to set it as a process.

  In particular, when organic silicone particles using an alkoxysilane compound having a non-hydrolyzable group as a raw material are fired, fine particles are cracked or chipped, cracks are easily generated due to decomposition or desorption of the organic groups. For this reason, it is preferable to perform preliminary baking at a temperature lower by about 50 ° C. to 100 ° C. than the decomposition temperature of the organic group. In this way, monodispersed silica particles can be obtained.

  As described above, in this embodiment, a large number of fine particles can be produced without using a surfactant. Therefore, after the fine particles are generated and concentrated in the solution and dried, there is no impurity, so it is not necessary to remove the impurity by filtration or centrifugation, and high production efficiency can be obtained.

  Next, the case where the fine particle group obtained as described above is used will be described.

  As described above, since the particle diameter of the fine particles is in the range of 100 nm or more and 1000 nm or less, the fine particle group can be composed of extremely small fine particles as compared with the conventional fine particles. And since the sphericity of each fine particle is 10 nm or less, the shape of each fine particle becomes a shape close to a true sphere. Furthermore, when the deviation coefficient of the particle diameter of the fine particles is 10.0% or less, the particle diameters of the fine particles constituting the fine particle group are made uniform.

  Applications of the fine particle group include spacers for liquid crystal cells, submicron standard particles, CMP slurry materials, cosmetic materials, photonic crystals and artificial opal materials, paint matting agents and film slippers, and liquid crystal display panels. There are uses as a material for a light diffusion plate, a light diffusion film and an antiglare film.

  For example, when using a group of particles as a spacer for a liquid crystal cell, the fine particles are nearly spherical and the particle size distribution is very narrow, so that the gap can be accurately controlled while narrowing the gap of the liquid crystal. it can. Thereby, it is possible to obtain a liquid crystal display element having ultrafast response while maintaining high quality.

  In addition, since the fine particles have a shape close to a true sphere and the particle size distribution is narrow, there is less variation in the particle size, and the utility value as a submicron standard particle is high.

  In addition, since the deviation coefficient is as low as 10.0% or less, giant particles or extremely fine particles do not exist in the fine particle group. Therefore, when used as a CMP slurry, the risk of damaging the silicon wafer is extremely low, and the entire polished surface of the silicon wafer can be uniformly polished.

  For example, when a fine particle group is used as a cosmetic raw material, the particle diameter can be reduced to about ½ of the wavelength of light, so that a structural color is expressed when the fine particles are arranged. Therefore, when the fine particle group is used as a raw material for cosmetics, a cosmetic product having an unprecedented design like a rainbow color can be obtained. Further, since the particle diameter of the fine particles can be strictly controlled, the color of the fine particles can be finely adjusted.

  And since a particle diameter is 100 nm or more, possibility that it will osmose | permeate in skin is low. In addition, the organic silicone particles or silica particles are harmless to the human body. By these things, the safety | security of cosmetics can be improved.

  In addition, if the fine particles constituting the fine particle group are arranged three-dimensionally and uniformly, the refractive index of light inside each fine particle changes, so it can be used as a photonic crystal, as an optical switch or a new laser element. It is valid.

  In addition, it is possible to produce artificial opals with the same components as natural opals whose color changes depending on the viewing angle if three-dimensional objects are obtained by arranging three-dimensional particles in three dimensions to obtain a three-dimensional object. is there.

  In addition, when the closest packing is used, a structural color is developed.

  Furthermore, the fine particles can be used as a matting agent for paints, a slipperiness imparting material for films, a light diffusing plate for liquid crystals, a light diffusing film or an antiglare film, Can have a function.

  When the sphericity of the fine particles is larger than 10 nm, the difference in the distance through which light passes between the fine particles becomes large. In this case, when used as a raw material for optical applications, that is, cosmetics, photonic crystals, and artificial opals, the sphericity of the fine particles is preferably 10 nm or less because the above-described effects cannot be sufficiently exhibited. .

  On the other hand, if the deviation coefficient is larger than 10.0%, similarly, the difference in the light transmission distance between the respective fine particles becomes large, so that a sufficient effect cannot be exhibited in an optical application. When the deviation coefficient is larger than 10.0%, the difference in particle diameter between the fine particles becomes large, and huge particles and ultrafine particles are included in the fine particle group. For this reason, it becomes difficult to set it as uses, such as a spacer for liquid crystal cells, a standard particle, and CMP slurry.

  Examples of the present invention will be described below.

Example 1
(1) Production of organic silicone particles 218 g of a mixed solution of RO water and ethanol containing 11% by weight of ammonia is stirred at 25 ° C., and 105 g of tetraethoxysilane is added to the solution at a constant rate of 0.5 g / min. Was continuously added dropwise.

  After completion of the dropwise addition of tetraethoxysilane, stirring was continued for 20 hours at the same temperature to complete the reaction. After completion of the reaction, the stirring was stopped and the solution containing ammonia was removed.

Next, the obtained fine particles were filtered and thoroughly washed until the methanol used as the washing liquid became neutral, and then dried at 80 ° C. for 3 hours. The obtained organic silicone particles had a sphericity of 5 nm, an average particle diameter of 231 nm, and a deviation coefficient of 3.8%. The group of fine particles adhering to the surface of the glass plate developed a pink structural color.
(2) Manufacture of silica particles The organosilicone particles were fired in three stages of 250 ° C for 12 hours, 500 ° C for 12 hours, and 750 ° C for 12 hours to obtain silica particles. The resulting silica particles had a sphericity of 6 nm, an average particle size of 204 nm, and a deviation coefficient of 4.0%. The group of fine particles attached to the surface of the glass plate developed a blue structural color.

(Example 2)
(1) Production of organic silicone particles 218 g of a mixed solution of RO water and ethanol containing 11% by weight of ammonia was stirred at 30 ° C., and 105 g of tetraethoxysilane was added to the solution at a constant rate of 0.5 g / min. Was continuously added dropwise.

  After completion of the dropwise addition, stirring was continued for 20 hours at the same temperature to complete the reaction. After completion of the reaction, the stirring was stopped and the solution containing ammonia was removed. Next, after filtering the obtained particle | grains and wash | cleaning sufficiently until the methanol used as a washing | cleaning liquid showed neutrality, the drying process was performed at 80 degreeC for 3 hours. The obtained organic silicone particles had a sphericity of 8 nm, an average particle diameter of 331 nm, and a deviation coefficient of 5.0%. The group of fine particles adhering to the surface of the glass plate showed a yellow structural color.

(2) Production of silica particles The organosilicone particles were fired in three stages of 250 ° C for 12 hours, 500 ° C for 12 hours, and 750 ° C for 12 hours. The resulting silica particles had a sphericity of 9 nm, an average particle size of 291 nm, and a deviation coefficient of 5.2%. The group of particles adhering to the glass developed a green structural color.

(Comparative Example 1)
(1) Production of organic silicone particles 218 g of a mixed solution of RO water and ethanol containing 0.5% by weight of ammonia was stirred at 30 ° C., and 105 g of tetraethoxysilane was added at 0.5 g / min to the solution. It was dripped continuously at a constant speed.

  After completion of the dropwise addition, stirring was continued for 20 hours at the same temperature to complete the reaction. After completion of the reaction, the stirring was stopped and the solution containing ammonia was removed.

  Next, after filtering the obtained particle | grains and wash | cleaning sufficiently until the methanol used as a washing | cleaning liquid showed neutrality, the drying process was performed at 80 degreeC for 3 hours. The obtained organic silicone particles had a sphericity of 90 nm, an average particle size of 1250 nm, and a deviation coefficient of 23.3%. No structural color was observed in the particles attached to the surface of the glass plate.

(2) Production of silica particles The organosilicone particles were fired in three stages of 250 ° C for 12 hours, 500 ° C for 12 hours, and 750 ° C for 12 hours. The obtained silica particles had a sphericity of 93 nm, an average particle diameter of 1075 nm, and a deviation coefficient of 27.9%. No structural color was observed in the particles attached to the surface of the glass plate.

  As described above, the present invention can be used for, for example, a spacer for liquid crystal cells, cosmetics, and the like.

Claims (7)

A group of fine particles composed of a large number of fine particles,
The particle diameter of the fine particles is in the range of 100 nm to 1000 nm, and the sphericity is 10 nm or less.
A fine particle group, wherein a deviation coefficient of a particle diameter of the fine particles is 10.0% or less. In the fine particle group according to claim 1,
A group of fine particles, wherein the raw material of the fine particles is alkoxysilane. In the fine particle group according to claim 2,
A group of fine particles, wherein the fine particles are produced using a sol-gel method. In the fine particle group according to claim 2,
A group of fine particles characterized in that the ammonia concentration during hydrolysis and dehydration condensation is 1% by weight or more and 28% by weight or less. In the fine particle group according to claim 2 or 3,
Non-hydrolyzable with an alkoxysilane compound consisting of only a hydrolyzable group alone or in an aqueous solution containing ammonia, or in a mixed solution of water and alcohol and / or ketone. A fine particle group comprising fine particles obtained by hydrolysis and dehydration condensation using a mixture with an alkoxysilane compound having a group as a raw material. In the fine particle group according to any one of claims 1 to 5,
A group of fine particles characterized by exhibiting a structural color when the fine particles are closely packed and used as a raw material for cosmetics. A method for producing a group of fine particles comprising a large number of fine particles having a particle size in the range of 100 nm to 1000 nm and a sphericity of 10 nm or less, wherein the deviation coefficient of the particle size of the fine particles is 10.0% or less. There,
A method for producing a fine particle group, wherein the fine particles are obtained using a sol-gel method using alkoxysilane as a raw material.