JP2006160783A - Method for producing aqueous organic-inorganic hybrid particle dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an aqueous organic-inorganic hybrid particle dispersion in which particles having a substantially equal particle size and a high degree of sphericity are stably dispersed. <P>SOLUTION: The method for producing an aqueous organic-inorganic hybrid particle dispersion comprises aging a mixture comprising (1) a polyvalent metal alkoxide or a hydrolytic condensation product of the polyvalent metal alkoxide, (2) a resin having an anionic group, (3) water or a water-miscible organic solvent and optionally a basic compound at room temperature or above, thereby advancing the hydrolytic condensation reaction of the polyvalent metal alkoxide or the hydrolytic condensation product thereof in the mixture; and then emulsifying the mixture in water to allow the polyvalent metal alkoxide or the hydrolytic condensation product of the polyvalent metal alkoxide in emulsified droplets to gelate. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an aqueous dispersion of organic-inorganic hybrid particles having a uniform particle size and stable dispersion.

  Conventionally, inorganic particles such as ceramics are used alone or in combination with organic polymers for various purposes such as increasing the amount, absorbing ultraviolet light, wear resistance, and imparting optical / electromagnetic properties. On the other hand, organic polymer particles are used in electrophotographic toners, matting agents, colorants, etc. by utilizing the flexibility, adhesion, and processability that are the characteristics of polymers. It is difficult to obtain properties such as properties, high elastic modulus, weather resistance, and solvent resistance. Therefore, in order to obtain materials having excellent properties of organic polymers and inorganic materials, both compounds are used, but in general, the compatibility between inorganic compounds and organic polymers is not sufficient, and various compounds using polyvalent metal alkoxides are used. However, it is not easy to form an organic-inorganic hybrid material that is a uniform composite material, and it has been difficult to put particles made of such a material into practical use.

As a specific method for producing organic-inorganic hybrid particles, for example, seed particles are swollen with a swelling solvent containing a polyvalent metal alkoxide, and then polymerized by an unsaturated double bond in the polyvalent metal alkoxide, and then the polyvalent metal alkoxide is polymerized. A production method in which an alkoxy group of a metal alkoxide is hydrolyzed and condensed is used (see Patent Document 1). However, the particles formed in the manufacturing method have seed particles arranged in the central portion and do not have a uniform internal structure. In addition, the production process such as swelling treatment and subsequent polymerization, and the use of a surfactant and a dispersant is complicated, and it is difficult to control the particle size. For this reason, the particles are not necessarily spherical, and it has been difficult to give the particles sufficient uniformity in terms of shape and physical properties. It was difficult to produce a particle size smaller than 1 μm.
Japanese Patent Laid-Open No. 07-265686

The present invention solves the problems related to the organic-inorganic hybrid particles.
That is, an object of the present invention is to provide a production method capable of easily producing organic-inorganic hybrid particles having stable dispersion, high sphericity, and uniform particle diameter.

The above object is achieved by the present invention described below.
That is, the present invention requires (1) a polyvalent metal alkoxide or a hydrolysis condensation product of a polyvalent metal alkoxide, (2) a resin having an anionic group, and (3) water or a water-miscible organic solvent. A method for producing an aqueous dispersion of an organic-inorganic hybrid in which a mixture containing a basic compound is emulsified in water and the polyvalent metal alkoxide or hydrolysis product of the polyvalent metal alkoxide in the emulsion droplets is gelled In addition, the present invention provides a method for producing an aqueous dispersion of organic-inorganic hybrid particles, wherein the mixture is aged at room temperature or higher before emulsification of the mixture.

  The organic-inorganic hybrid particles obtained from the method for producing an aqueous dispersion of organic-inorganic hybrid particles containing a reaction gel of an anionic group and a polyvalent metal alkoxide according to the present invention have a uniform mixture of organic and inorganic components. Thus, an aqueous dispersion having a uniform particle size and excellent dispersion stability is formed. Furthermore, it has excellent granulation properties during production, is extremely easy to be granulated, and has a high sphericity. The organic-inorganic hybrid particles obtained from the method for producing an aqueous dispersion of organic-inorganic hybrid particles of the present invention form a domain in which the organic component and the inorganic component have a fine structure, and in addition to the hardness as abrasive particles, wear resistance It combines the characteristics of conventional inorganic particles such as flexibility, heat resistance, high elastic modulus, weather resistance, and solvent resistance with the characteristics of conventional organic particles such as flexibility, adhesion, workability, and granulation.

  The organic-inorganic hybrid particle in the present invention is a composite particle in which an organic polymer and an inorganic polymer are uniformly distributed in the same particle, and the properties as an inorganic polymer, such as wear resistance and heat resistance, It is a particle that also has characteristics as an organic polymer such as flexibility. The organic-inorganic hybrid particles of the present invention are composite particles containing a reaction gel of a resin having an anionic group and a polyvalent metal alkoxide. Here, the reaction gel of the polyvalent metal alkoxide is a wet gel or a dry gel containing a metal oxide formed by further proceeding with the sol formed by hydrolysis and polymerization of the polyvalent metal alkoxide. is there.

The anionic group of the resin used in the production method of the present invention is not particularly limited and includes a carboxyl group, a sulfonic acid group, a sulfinic acid group, a phosphoric acid group, and a phenolic hydroxyl group. A general resin can be used, which is preferable because it makes it easy to form organic-inorganic hybrid particles by the production method described later.
The resin having an anionic group is not particularly limited, such as a natural resin and a synthetic resin, but a resin suitable for the production method described below is preferably a resin soluble in an organic solvent in the absence of a basic compound. Specifically, acrylic acid resin, maleic acid resin, polyester resin, epoxy resin, phenol resin and the like can be mentioned, and these can be subjected to three-dimensional crosslinking by a known method as necessary after formation of the composite particles. As the acrylic resin, for example, a copolymer of (meth) acrylic acid with at least one monomer selected from the group consisting of styrene, substituted styrene, (meth) acrylic acid ester, and hydroxyalkyl (meth) acrylic acid ester is It is preferable in terms of resin particle formation and crosslinking with polyvalent metal ions.

  Specifically, styrene; substituted styrene such as α-methylstyrene; acrylic acid methyl ester, acrylic acid ethyl ester, acrylic acid butyl ester, acrylic acid 2-ethylhexyl ester, and other acrylic acid esters; methacrylic acid methyl ester, ethyl methacrylate At least one monomer selected from esters, methacrylic acid esters such as butyl methacrylate and 2-ethylhexyl methacrylate; and hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl methacrylate; and acrylic acid and methacrylic acid. A (meth) acrylic acid copolymer containing at least one monomer selected from acids is preferred.

The acid value of the resin having an anionic group is not particularly limited. However, when the acid value is less than 10, the resin tends to be insufficient in dispersibility, and an aqueous dispersion of organic-inorganic hybrid particles in the production method described later is formed. Tends to be insufficient. When the acid value exceeds 200, the resin tends to swell or dissolve in water in the production method described later, and it tends to be difficult to obtain a desired aqueous dispersion of organic-inorganic hybrid particles. For this reason, it is preferable that the acid value of resin which has anionic group exists in the range of 10-200. In particular, in the case of a self-water dispersible resin in the range of 50 to 200, since a part of the anionic group of the resin is neutralized with a base, it exhibits good dispersibility or solubility in water. More preferred.
The molecular weight range of the resin is not particularly limited, but a resin having a molecular weight of 1000 or more and 100,000 or less is more preferable. The ratio of the resin to the polyvalent metal alkoxide is not particularly limited, but is preferably in the range of 1:10 to 10: 1 by mass ratio.

When increasing the hardness of the organic-inorganic hybrid particles, it is not preferable to use a large amount of a monomer having a low glass transition temperature, such as (meth) acrylic acid ester, in the combination of the above monomers, and the glass transition of the resin of the present invention. The temperature is preferably room temperature or higher, preferably 50 ° C. or higher.
The resin used in the method for producing an aqueous dispersion of organic-inorganic hybrid particles of the present invention can obtain particles having high strength by organic-inorganic hybridization. However, a crosslinkable monomer and an initiator or a catalyst are previously used as organic-inorganic hybrid particles. Incorporating and cross-linking after particle formation, or preferably taking polyvalent metal ions when forming organic-inorganic hybrid particles to form a so-called ionomer resin in which a part of the anionic group of the resin having an anionic group is cross-linked Thus, it can be made tougher organic-inorganic hybrid particles.

The metal of the polyvalent metal alkoxide used in the production method supplement of the present invention is a divalent or higher polyvalent metal, such as silicon, titanium, zirconium, cerium, calcium, barium, manganese, zinc, nickel, tin, copper, iron, Although there are cobalt, boron, aluminum, tungsten, bismuth, molybdenum, niobium, yttrium, strontium, gallium, germanium, and the like, it is not limited to these, and at least one kind can be included.
As the alkoxide combined with the metal, at least one alkoxy group (OR) is bonded to the metal, and R of the alkoxy group (OR) is an alkyl group, an alkylene group, an allyl group, a vinyl group, or a vinylbenzyl group. , A (meth) acrylate group or the like may be selected arbitrarily, but an alkyl group having 1 to 4 carbon atoms is common and easy to use. In addition, other functional groups may be directly bonded to the metal. For example, a hydroxyl group, an alkyl group, an alkylene group, an allyl group, a vinyl group, a vinylbenzyl group, a (meth) acrylate group, a carboxyl group, an acetylacetone group, an acetoacetate group. There are ligands such as acetate groups. When all the functional groups bonded to the metal are alkoxy groups, it is possible to form inorganic polymer chains consisting only of siloxane bonds by hydrolytic polycondensation of polyvalent metal alkoxides, resulting in higher properties as inorganic compounds. It is preferable because it can be expressed. Specific examples of the compound include, but are not limited to, the following.

  In the production method of the present invention, (1) a polyvalent metal alkoxide or a hydrolysis condensation product of a polyvalent metal alkoxide, (2) a resin having an anionic group, and (3) water or a water-miscible organic solvent An aqueous dispersion of an organic-inorganic hybrid that emulsifies a mixture containing a basic compound as necessary in water and gels the polyvalent metal alkoxide or the hydrolysis product of the polyvalent metal alkoxide in the emulsion droplets. In the production method, the mixture is aged at a temperature of room temperature or higher before emulsification of the mixture.

Aging is performed by heating at room temperature, preferably 60 ° C. or more and 100 ° C. or less. A suitable aging time is 1 hour to 48 hours, and an optimum time may be selected according to temperature conditions. At this time, care should be taken so that gelation does not proceed excessively.
Aging causes hydrolysis and condensation of the polyvalent metal alkoxide, or further hydrolysis and condensation of the polyvalent metal alkoxide. For this reason, a mixture containing a polyvalent metal alkoxide, a resin having an anionic group, and water or a water-miscible organic solvent is rich in hydrolytic condensation products of a polyvalent metal alkoxide containing a metal oxide sol. In addition, they have a high affinity with a resin having an anionic group and are uniformly mixed with a resin having an anionic group in a mixture before emulsification in advance. For this reason, even in the emulsified droplets formed by emulsification, the hydrolysis condensate of the resin having an anionic group and the polyvalent metal alkoxide is uniformly mixed. Condensation further proceeds and gelation proceeds, and when the solvent in the droplets is distilled off, organic-inorganic hybrid particles in which the resin component and the inorganic material component are uniformly mixed are formed. Further, by reducing the amount of the unreacted polyvalent metal alkoxide as much as possible, a more complete inorganic material portion is formed by subsequent condensation of the hydrolysis product.

Examples of the water-miscible organic solvent for dissolving the resin having an anionic group contained in the mixture include ketone solvents such as acetone, dimethyl ketone, and methyl ethyl ketone, and alcohol solvents such as methanol, ethanol, and isopropyl alcohol. , Ester solvents such as ethyl acetate, glycol ether solvents such as ethylene glycol monomethyl ether and ethylene glycol dimethyl ether, amides, etc., which are miscible with water alone or in combination with other organic solvents Can be used. When the resin component is an acrylic resin, a good aqueous dispersion can be obtained by using a combination of at least one or more of ketone solvents and alcohols. In this way, the hydrolysis of the polyvalent metal alkoxide is suppressed during emulsification, and the resin and the polyvalent metal alkoxide can be used in combination to allow the resin and the polyvalent metal alkoxide to be uniformly mixed before the condensation polymerization proceeds and the gelation proceeds. good.
The amount of the organic solvent used is not particularly defined as long as the effect of the present invention is achieved, but is preferably an amount such that the weight ratio of resin / organic solvent is 1/1 to 1/20.
As hydrolysis inhibitors other than the alcohol amine (base) and alcohol (organic solvent) described above, for example, chelating agents such as acetylacetone, acetoacetate ester, diacetoacetate alkyl ester, and polyols such as acetoin, diethylene glycol and polyethylene glycol are suitable. It is.

After aging the mixture, the mixture is emulsified in water. The anionic group in the resin containing an anionic group used in the present invention is more excellent in dispersion stability of the organic-inorganic hybrid particles when at least a part thereof forms a counter ion with the basic compound. It is easy to emulsify and can form a good aqueous dispersion.
For this reason, it is preferable that at least a part of the anionic group in the resin forms a counter ion with a monovalent base so that the particle surface becomes hydrophilic. Examples of the monovalent base herein include alkali metals such as lithium, potassium, and sodium, and organic bases such as ammonia and organic amines, alcohol amines, morpholines, and pyridines. Therefore, it is better to use alcohol amines such as monoethanolamine, diethanolamine, and triethanolamine, which have the effect of suppressing rapid hydrolysis of polyvalent metal alkoxides while being a hydrolysis catalyst, during emulsification. This is preferable because the resin and the polyvalent metal oxide are mixed more uniformly. When the organic / inorganic hybrid particles of the present invention are used particularly for semiconductors, it is preferable to reduce the alkali metal ion component as much as possible, and to use alcohol amine or the like because the adverse effects on the semiconductor characteristics due to residual metal ions can be eliminated. .

The amount of the monovalent base used should be an amount corresponding to 10% or more, preferably 50 mol% or more of the anionic group of the resin, and an amount corresponding to 100 mol% or more if necessary depending on the purpose of use. Even when a base is added, an aqueous dispersion of organic-inorganic hybrid particles that are stable in a fine particle size with an increased free base amount can be obtained.
On the other hand, when the amount of the monovalent base added is reduced, the particle diameter of the organic-inorganic hybrid particles can be increased. Thus, by adjusting the amount of monovalent base, an aqueous dispersion of organic-inorganic hybrid particles having a uniform particle size and an arbitrary particle size can be obtained.

  In the production method of the present invention, (1) a polyvalent metal alkoxide or a hydrolysis condensation product of a polyvalent metal alkoxide, (2) a resin having an anionic group, (3) water or a water-miscible organic solvent, If necessary, a mixture containing a basic compound is produced, and organic-inorganic hybrid particles are produced through aging and emulsification of the mixture, but there are some examples of the composition and production method of the mixture, and the emulsification method of the mixture. It is possible to use this method.

A) For example, a mixture containing (1) a polyvalent metal alkoxide or a hydrolysis product of a polyvalent metal alkoxide, (2) a resin having an anionic group, and (3) a water-miscible organic solvent is prepared. After aging, a method of producing an aqueous dispersion of organic-inorganic hybrid particles by adding water to the mixture and emulsifying in the presence of a basic compound can be used. This method is preferable because the particle size can be controlled by the addition amount of the basic compound.

More specifically, the production method can be carried out as follows: a) First, a resin having an anionic group and a polyvalent metal alkoxide are dissolved in a water-miscible organic solvent solution. Next, in order to hydrolyze the polyvalent metal alkoxide, an appropriate amount of water, acid or alkali catalyst is added. A known acid catalyst can be used, but a resin having an anionic group also functions as an acid catalyst. Known alkali catalysts are used, but an emulsifying base for making an aqueous dispersion may be used.
After aging, a base and water are added and emulsified in a water-miscible organic solvent solution of a resin having an anionic group and a polyvalent metal alkoxide. Specifically, a resin having an anionic group is dissolved in a water-miscible organic solvent solution, and inorganic or organic insoluble particles are dispersed by kneading as necessary at this point, after which a base is added, and then Then, water is added little by little to emulsify the resin to form composite particles of the resin and the polyvalent metal alkoxide reaction gel. Even if the polyvalent metal alkoxide reaction gel remains as it is, it undergoes hydrolysis or polycondensation reaction in a resin having an anionic group, and gelation proceeds to form organic-inorganic hybrid particles, but it becomes more gelled by distilling off the organic solvent. Progresses to strong organic-inorganic hybrid particles. At this time, by placing it in a high-temperature environment with an autoclave or the like, stronger organic-inorganic hybrid particles containing a metal oxide are obtained.

Furthermore, the following can be given as a method for producing an aqueous dispersion of organic-inorganic hybrid particles using another method for preparing a mixture before emulsification and another method for emulsifying the mixture.
(B) A polyvalent metal alkoxide or a hydrolysis condensation product thereof is added to water or a water-miscible organic solvent containing an acid catalyst or a base catalyst to prepare a mixture, which is then hydrolyzed at an appropriate time and temperature. Thereafter, a resin having an anionic group or a resin solution is added and dissolved. Furthermore, a base and water are added little by little to emulsify the resin to produce an emulsified droplet containing the polyvalent metal alkoxide and its hydrolysis condensation product, and the solvent in the liquid is distilled off into the resin particles. An aqueous dispersion of organic-inorganic hybrid particles having a polyvalent metal alkoxide reaction gel is prepared.

(C) In an aqueous solution of a resin having an anionic group, in which at least a part of the anionic group is neutralized with a base, an alcohol is added as necessary to prepare a mixture, , Hydrolysis of polyvalent metal alkoxide or its hydrolysis condensation product, or hydrolysis and condensation. Emulsified droplets containing the hydrolysis condensation product of the resin and the polyvalent metal alkoxide are prepared by diluting with water as necessary, and then reducing the solubility of the resin in the mixture. As a specific method for reducing the solubility of the resin, a method in which at least a part of the volatile component is distilled off in advance using a volatile base such as ammonia or the pH is lowered by adding an acid can be used. .
In any of the methods, a mixture containing a polyvalent metal alkoxide or a hydrolysis-condensation product thereof and a resin having an anionic group is subjected to hydrolysis before hydrolysis, or hydrolysis and condensation. It is important to perform sufficient aging.

The aqueous dispersion of organic-inorganic hybrid particles obtained by the above production method is further heated to further proceed with gelation, and then at least part of the liquid component is removed to obtain an aqueous dispersion or powder particles of organic-inorganic hybrid particles. Can also be manufactured. The aqueous dispersion of the obtained organic-inorganic hybrid particles is heated by further laminating unreacted polyvalent metal alkoxide as a hydrolysis product on the surface of the organic-inorganic hybrid particles, It becomes possible to do. On the other hand, by removing unreacted polyvalent metal alkoxide, the dispersion stability of the aqueous dispersion can be greatly improved, and organic-inorganic hybrid particles having a uniform internal structure having no inclined structure can be produced. Can do.
In addition, you may add a crosslinking agent in the arbitrary steps before insolubilizing resin as needed.

  The organic-inorganic hybrid particles can also be produced by further heating the aqueous dispersion of organic-inorganic hybrid particles obtained by the production method described above to further promote gelation and then removing the liquid component.

In addition to the aging, heating of the obtained aqueous dispersion of organic-inorganic hybrid particles provides a more stable dispersion by the method for producing organic-inorganic hybrid particles having a step of completing the gelation of the polyvalent metal alkoxide.
A more stable dispersion can be obtained by the method for producing an aqueous dispersion of organic-inorganic hybrid particles having a step of removing an organic solvent or unreacted polyvalent metal alkoxide from the obtained aqueous dispersion of organic-inorganic hybrid particles.
In the present invention, the inorganic or organic particles prepared separately can be used as a core, and the surface can be coated with the hybrid of the present invention to facilitate particle formation or reduce the cost.

The aqueous dispersion of organic-inorganic hybrid particles obtained by the above production method can be used as a dispersion as it is, but it may be used as a powder by completely removing liquid components such as water and organic solvent. Further, extremely porous inorganic particles having high surface activity can be obtained by further baking the powder at a temperature of several hundred degrees or more, wet-oxidizing organic components, or removing soluble components with an organic solvent. In particular, firing of organic-inorganic hybrid particles in which particles are ion-crosslinked with polyvalent metal ions of an element different from the polyvalent metal alkoxide used can easily obtain porous inorganic particles uniformly doped with different metals. It becomes possible.
An aqueous dispersion containing abrasive particles composed of organic-inorganic hybrid particles obtained in accordance with the above-described production method, when used as it is as an aqueous abrasive slurry, an organic solvent having a boiling point lower than that of water as much as possible after emulsification. It is desirable to prepare by introducing a step of removing, whereby the dissolution and swelling of the abrasive particles are eliminated, and an excellent polishing ability and a stable aqueous dispersion can be obtained.
Organic-inorganic hybrid particles obtained by the present invention and inorganic particles obtained by removing organic components from organic-inorganic hybrid particles include, for example, spacers, liquid chromatography fillers, cosmetics, resin compositions, paints, magnetic materials, clinical diagnostic agents It can be suitably used in a wide range of fields.

Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following examples, “part” represents “part by mass”.
Example 1
8 parts of styrene acrylic acid resin (styrene / acrylic acid / methacrylic acid = 77/13/10; acid value 150; molecular weight 50,000) and 1 part of acetylacetone aluminum salt into 20 parts of methyl ethyl ketone, 10 parts of isopropyl alcohol and 10 parts of acetylacetone Dissolve. 20 parts of tetraethoxysilane Si (O—C ₂ H ₅ ) ₄ is dissolved in the obtained resin solution, 1 part of triethanolamine is further added, and the mixture is stirred at room temperature for 24 hours.
Next, 30 parts of a 10% triethanolamine aqueous solution was added with stirring, and then 30 parts of pure water was added dropwise at a rate of 5 ml per minute to obtain a dispersion. Thereafter, methyl ethyl ketone, isopropyl alcohol, a part of water and unreacted tetraethoxysilane were distilled off using a rotary evaporator to obtain an aqueous dispersion.
The obtained aqueous dispersion was centrifuged to remove coarse particles to obtain an organic-inorganic hybrid particle aqueous dispersion. The obtained aqueous dispersion was stable with no increase in viscosity over time. The organic-inorganic hybrid particles in the obtained aqueous medium had a volume average particle size of 180 nm, good sphericity, good uniformity of particle size, no sediment, and stable dispersion.

(Comparative Example 1)
Immediately without stirring for 24 hours at room temperature in Example 1, 30 parts of a 10% triethanolamine aqueous solution was added with stirring, and then 30 parts of pure water was added dropwise at a rate of 5 ml / min to obtain a dispersion. Thereafter, methyl ethyl ketone, isopropyl alcohol, a part of water and unreacted tetraethoxysilane were distilled off using a rotary evaporator to obtain an aqueous dispersion.
The obtained aqueous dispersion was centrifuged to remove coarse particles to obtain an organic-inorganic hybrid particle aqueous dispersion. The obtained organic-inorganic hybrid particles had a volume average particle size of 180 nm and good particle size uniformity, and there was no sediment, but the whole gelled after 2 days.

(Example 2)
5 parts of styrene acrylic acid resin (styrene / acrylic acid / methacrylic acid = 77/13/10; acid value 150; molecular weight 50,000) and 0.2 part of acetylacetone cerium salt, 20 parts of methyl ethyl ketone, 20 parts of isopropyl alcohol, acetylacetone 2 Dissolve in part. 30 parts of tetraethoxysilane Si (O—C ₂ H ₅ ) ₄ is dissolved in the obtained resin solution, 1 part of triethanolamine is further added, and the mixture is heated at 60 ° C. for 6 hours. After returning to room temperature, 1 part of triethanolamine was added with stirring, and then 40 parts of pure water was added dropwise at a rate of 5 ml / min to obtain a dispersion. Thereafter, methyl ethyl ketone, isopropyl alcohol, a part of water and unreacted tetraethoxysilane were distilled off using a rotary evaporator to obtain an aqueous dispersion.
The obtained aqueous dispersion was centrifuged to remove coarse particles to obtain an organic-inorganic hybrid particle aqueous dispersion. The obtained aqueous dispersion was stable with no increase in viscosity over time. The organic-inorganic hybrid particles in the obtained aqueous medium had a volume average particle size of 200 nm, good sphericity, good particle size uniformity, no sediment, and stable dispersion.

(Comparative Example 2)
In Example 2, heating was omitted at 60 ° C. for 6 hours, 1 part of triethanolamine was added with stirring, and then 40 parts of pure water was added dropwise at a rate of 5 ml / min to obtain a dispersion. Thereafter, methyl ethyl ketone, isopropyl alcohol, a part of water and unreacted tetraethoxysilane were distilled off using a rotary evaporator to obtain an aqueous dispersion.
The obtained aqueous dispersion was centrifuged to remove coarse particles to obtain an organic-inorganic hybrid particle aqueous dispersion. The obtained organic-inorganic hybrid particles had an initial volume average particle size of 200 nm and good particle size uniformity and no sediment, but after 3 days the viscosity of the aqueous dispersion increased and gelled.

(Example 3)
5 parts of styrene acrylic acid resin (styrene / acrylic acid / methacrylic acid = 77/13/10; acid value 150; molecular weight 50,000) is dissolved in 20 parts of methyl ethyl ketone and 20 parts of isopropyl alcohol. 30 parts of tetraethoxysilane Si (O—C ₂ H ₅ ) ₄ is dissolved in the obtained resin solution, 10 parts of water is further added, and the mixture is refluxed at 60 ° C. for 3 hours.
After returning to room temperature and storing at 30 ° C. for 24 hours, 2 parts of triethanolamine was added with stirring, and then 40 parts of pure water was added dropwise at a rate of 5 ml / min to obtain a dispersion. Thereafter, methyl ethyl ketone, isopropyl alcohol and a part of water were distilled off using a rotary evaporator to obtain an aqueous dispersion. The obtained aqueous dispersion was heated and stirred in an autoclave at 80 ° C. for 6 hours, and then coarse particles were removed by centrifugation to obtain an organic-inorganic hybrid particle aqueous dispersion. The obtained aqueous dispersion was stable with no increase in viscosity over time. The organic-inorganic hybrid particles in the obtained aqueous medium had a volume average particle size of 120 nm, good sphericity, good particle size uniformity, no sediment, and stable dispersion.

(Comparative Example 3)
In Example 1, the mixture was refluxed at 60 ° C. for 3 hours and returned to room temperature, and storage at 30 ° C. for 24 hours was omitted to obtain an aqueous dispersion. The obtained aqueous dispersion was heated and stirred in an autoclave at 80 ° C. for 6 hours, and then coarse particles were removed by centrifugation to obtain an organic-inorganic hybrid particle aqueous dispersion. The obtained organic-inorganic hybrid particle aqueous dispersion was gelled with many aggregates.
As shown in the examples above, organic-inorganic hybrid particles having excellent particle size uniformity and good dispersibility could be produced.

  The organic-inorganic hybrid particle aqueous dispersion and hybrid particles obtained from the method for producing an aqueous dispersion of organic-inorganic hybrid particles of the present invention include an abrasive / abrasion-resistant coating material or a molded article / adhesive using its mechanical strength. Various industrial uses as particles alone or paints, such as various optical films and optical communication materials that use optical properties, electronic materials such as semiconductor sealing materials that use their electrical properties and heat resistance, and other composite materials Is possible.

Claims (7)

(1) a polyvalent metal alkoxide or a hydrolysis condensation product of a polyvalent metal alkoxide, (2) a resin having an anionic group, (3) water or a water-miscible organic solvent, and a basic compound as necessary A method for producing an aqueous dispersion of an organic-inorganic hybrid in which a polyhydric metal alkoxide or a hydrolyzed product of a polyvalent metal alkoxide in an emulsified droplet is gelled in water, A method for producing an aqueous dispersion of organic-inorganic hybrid particles, wherein the mixture is aged at room temperature or higher before emulsification. The mixture contains (1) a polyvalent metal alkoxide or a hydrolysis product of a polyvalent metal alkoxide, (2) a resin having an anionic group, and (3) a water-miscible organic solvent in the presence of a basic compound. The method for producing an aqueous dispersion of organic-inorganic hybrid particles according to claim 1, wherein water is added to the mixture to emulsify. An aqueous dispersion of organic-inorganic hybrid particles having a step of completing the gelation of the polyvalent metal alkoxide by further heating the aqueous dispersion of organic-inorganic hybrid particles produced by the production method according to claim 1 or 2. Manufacturing method. Production of an aqueous dispersion of organic-inorganic hybrid particles having a step of removing an organic solvent or unreacted polyvalent metal alkoxide from the aqueous dispersion of organic-inorganic hybrid particles produced by the production method according to claim 1 or 2. Method. The method for producing an aqueous dispersion of organic-inorganic hybrid particles according to claim 1 or 2, wherein the acid value of the resin having an anionic group is 10 to 200. The method for producing an aqueous dispersion of organic-inorganic hybrid particles according to claim 1 or 2, wherein the anionic group of the resin having an anionic group is a carboxyl group. The resin having the anionic group is a copolymer of at least one monomer selected from the group consisting of styrene, substituted styrene, (meth) acrylic acid ester, and hydroxyalkyl (meth) acrylic acid ester, and (meth) acrylic acid. The method for producing an aqueous dispersion of organic-inorganic hybrid particles according to claim 1, which is a coalescence.