JP6801249B2 - Organic-inorganic composite particles, their latex, and their manufacturing method - Google Patents

Description

The present invention relates to organic-inorganic composite particles and latex thereof.

Molds made of thermoplastic resins are widely used in various fields such as automobiles and electric / electronic devices, and these thermoplastic resins have high impact resistance, color development, weather resistance, and flow. Gender is required. In order to improve these physical properties, a method of adding a resin modifier is common.
For example, in Patent Document 1, a composite rubber-based graft copolymer obtained by graft-polymerizing a vinyl-based monomer to a composite rubber composed of a polyorganosiloxane rubber and a polyalkyl (meth) acrylate rubber is used as a resin modifier. Has been proposed.
On the other hand, organic-inorganic composite materials are attracting attention because they are expected to improve physical properties such as mechanical strength, optical physical properties, and thermal physical properties of the matrix by finely dispersing inorganic fine particles in a matrix made of an organic resin. Patent Document 2 proposes a technique for improving the refractive index of the entire composite material by finely dispersing inorganic fine particles having a high refractive index in the matrix. About an organic-inorganic composite material using polyorganosiloxane as a matrix. Has also been proposed.

Japanese Unexamined Patent Publication No. 63-69859 JP-A-2007-302799

In the method proposed in Patent Document 1, since the refractive index of the polyorganosiloxane rubber is low, there is a problem that the color development property is remarkably lowered as compared with other impact resistance modifiers. Further, in Patent Document 1, no measures for improving the refractive index are discussed.
Further, in the method proposed in Patent Document 2, a polyorganosiloxane is produced by cross-linking a siloxane compound having a reactive functional group, and the polyorganosiloxane using an organosiloxane having no reactive functional group is used. Has not been manufactured. In addition, particulate polyorganosiloxane used as a material for resin modifiers has not been produced.
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide organic-inorganic composite particles having an improved refractive index by containing inorganic fine particles.

As a result of diligent research to solve the above problems, the present inventors have completed the present invention. That is, the present invention has the following features [1] to [7].
[1] Inorganic fine particles are organic-inorganic composite particles in which inorganic fine particles are dispersed in a polyorganosiloxane containing an organosiloxane unit represented by the following general formula (1), and the inorganic fine particles are zirconium oxide, titanium oxide, tin oxide. , Alumina, magnesium oxide, antimony oxide and calcium oxide. Organic-inorganic composite particles which are compounds selected from the group.
(In formula (1), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively.)
[2] An organic-inorganic composite particle latex containing the organic-inorganic composite particles according to [1].
[3] A method for producing an organic-inorganic composite particle latex in which inorganic fine particles are dispersed in a polyorganosiloxane containing an organosiloxane unit represented by the following general formula (1).
The polyorganosiloxane is obtained by polymerizing an organosiloxane.
A method for producing an organic-inorganic composite particle latex in which the inorganic fine particles are a compound selected from the group consisting of zirconium oxide, titanium oxide, tin oxide, alumina, magnesium oxide, antimony oxide and calcium oxide.
(In formula (1), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively.)
[4] The organosiloxane is one or more selected from the group composed of the cyclic diorganosiloxane represented by the following general formula (2) and the chain-shaped diorganosiloxane represented by the following general formula (3). , [3]. The method for producing an organic-inorganic composite particle latex.
(In formula (2), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively. N is a natural number of 2 to 10.)
(In formula (3), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively. N is a natural number of 2 to 10).
[5] A method for producing an organic-inorganic composite particle latex, in which an emulsion obtained by pre-stirring a mixture of an organosiloxane dispersion of inorganic fine particles, an emulsifier, an acid catalyst, and water is heated and polymerized.
One or more of the inorganic fine particle organosiloxane dispersions selected from the group consisting of the cyclic diorganosiloxane represented by the general formula (2) and the chain-shaped diorganosiloxane represented by the general formula (3). Inorganic fine particles are dispersed in the organosiloxane of
The method for producing an organic-inorganic composite particle latex according to [4].
[6] The method for producing an organic-inorganic composite particle latex according to [5], wherein the amount of the acid catalyst added is 0.25 times or more the mass of the inorganic fine particles.
[7] After mixing a carboxylic acid having 4 or more carbon atoms in an aqueous dispersion in which inorganic fine particles are dispersed in water, water is removed to hydrophobize the inorganic fine particles, and the hydrophobized inorganic fine particles are treated as organoxane. The method for producing an organic-inorganic composite particle latex according to [5] or [6], wherein an organosiloxane dispersion liquid of inorganic fine particles is obtained by dispersing in siloxane.

According to the present invention, an inorganic fine particle composite latex having an improved refractive index can be obtained.

<Inorganic fine particles>
The inorganic fine particles of the present invention are inorganic fine particles formed from oxides, composites thereof, and the like.
Examples of the oxide include zirconium oxide, titanium oxide, tin oxide, alumina, magnesium oxide, antimony oxide, and calcium oxide.
One type of these inorganic fine particles may be used alone, or two or more types may be used in combination.

The inorganic fine particles are preferably inorganic oxides from the viewpoint of being transparent and having a high refractive index, more preferably zirconium oxide (ZrO ₂ ), titanium oxide (TIO ₂ ) , and tin oxide (SnO ₂ ), and their transparency and refractive index. Zirconium oxide is more preferable because of its height.

The particle size of the inorganic fine particles is preferably 100 nm or less, more preferably 30 nm or less, and even more preferably 20 nm or less, in terms of forming highly transparent organic-inorganic composite particles, the average particle size obtained by dynamic light scattering (DLS) is 100 nm or less. Further, from the viewpoint of easy dispersion of inorganic fine particles in organosiloxane, the average particle diameter obtained by DLS is preferably 0.5 nm or more, more preferably 1 nm or more, still more preferably 5 nm or more.

<Hydrophobic treatment>
In order to disperse the inorganic fine particles in the organosiloxane, the inorganic fine particles may be subjected to various known hydrophobizing treatments, if necessary. The hydrophobizing treatment is to improve the affinity with organic substances such as organic solvents and resins by hydrophobicizing the surface of hydrophilic inorganic fine particles with a predetermined hydrophobizing agent. is there.
Examples of the compound that can be used for such hydrophobization treatment include hexamethyldisilazane, trimethylethoxysilane, trimethylmethoxysilane, trimethylsilyl chloride, methyltriethoxysilane, dimethyldiethoxysilane, decyltrimethoxysilane, and vinyltricrol. Organic silane coupling agents such as silane, vinyltrimethoxysilane, vinyltriethoxysilane, N- (2-aminoethyl) -3-aminopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane; butanoic acid, isocyanate, Carboxylic acids such as methacrylic acid, hexanoic acid, octanoic acid, oleic acid, linoleic acid, and lauric acid; acrylic groups such as acryloyl isocyanate, methacryloyl isocyanate, 2-isocyanate ethyl acrylate, and 2-isocyanate ethyl methacrylate. Examples thereof include isocyanate compounds having.

Of these, the method using a carboxylic acid is preferable because the amount of the hydrophobizing agent can be suppressed to a small amount. The carboxylic acid used for the hydrophobization treatment is a carboxylic acid having 4 or more carbon atoms and a thiocarboxylic acid having 4 or more carbon atoms in which the oxygen atom constituting the carboxyl group of the carboxylic acid is replaced with a sulfur atom from the viewpoint of dispersibility of the inorganic fine particles. It is more preferable to use an acid or a dithiocarboxylic acid having 4 or more carbon atoms. From the viewpoint of availability, the carboxylic acid is more preferably a saturated or unsaturated carboxylic acid having 4 to 18 carbon atoms.
Examples thereof include monovalent aliphatic carboxylic acids such as butanoic acid, isobutane acid, methacrylic acid, caproic acid, octanoic acid, oleic acid, linoleic acid and lauric acid. One of these may be used alone, or two or more thereof may be used in combination.
In particular, when the inorganic fine particles after the hydrophobizing treatment are dispersed in a resin and used, it is preferable to appropriately select and use a carboxylic acid that easily improves the affinity with the resin according to the type of the resin and the like. ..

As a hydrophobizing treatment method, hydrophobized inorganic fine particles can be obtained by performing the following steps.
(1) In a transparent inorganic fine particle dispersion in which hydrophilic inorganic fine particles are dispersed in water or an organic solvent, an appropriate amount of carboxylic acid as a hydrophobizing agent, a predetermined amount of a water-insoluble organic solvent, and an amphoteric organic solvent The process of mixing and stirring.
(2) After that, a step of obtaining a dispersion liquid in which inorganic fine particles hydrophobicized in a water-insoluble organic solvent are transparently and uniformly dispersed by removing mainly water and an amphoteric organic solvent by azeotrope.
(3) A step of separating and obtaining the inorganic fine particles by further evaporating and removing the water-insoluble organic solvent from the dispersion liquid in which the inorganic fine particles are transparently and uniformly dispersed in the water-insoluble organic solvent obtained above.

In the above, the amphoteric organic solvent means that it is water-soluble and also has compatibility with a water-insoluble organic solvent. Examples of such an amphoteric organic solvent include alcohols such as methanol, ethanol, propanol and butanol; and acetone. One of these may be used alone, or two or more thereof may be used in combination.
The amphoteric organic solvent used mainly produces a uniform liquid phase containing water and a water-insoluble organic solvent, and is therefore used for the purpose of removing water from the liquid phase by azeotropically boiling with water. Therefore, it is preferable that a uniform liquid phase containing water and a water-insoluble organic solvent is produced in a small amount and that the solvent has a relatively low boiling point, and it is experimental depending on the type of the water-insoluble organic solvent used. It is preferable to determine. In general, alcohol or acetone having a relatively small molecular weight and having a carbon number of 3 or less, which is highly compatible with water, is preferably used.

Examples of the water-insoluble organic solvent include aromatic hydrocarbons such as toluene, xylene and benzene; and alicyclic hydrocarbons such as cyclohexane. One of these may be used alone, or two or more thereof may be used in combination.
The water-insoluble organic solvent is for dispersing and holding the hydrophobized inorganic fine particles, and is preferably one having a low vapor pressure that does not cause excessive evaporation when water is removed. After that, it is preferable to select and use a compound having high compatibility with the target resin compound.

The amount of the hydrophobizing agent used for the hydrophobizing treatment varies depending on the type and particle size of the inorganic fine particles used, but is 0.05 times the mass of the inorganic fine particles to be hydrophobized from the viewpoint of improving the dispersibility of the inorganic fine particles. The above amount is preferable, 0.1 times amount or more is more preferable, and 0.2 times amount or more is further preferable. Further, when the main purpose is to increase the refractive index of the resin, the amount is preferably 10 times or less the mass of the inorganic fine particles in that the refractive index can be increased by reducing the amount of the hydrophobizing agent. A 5-fold amount or less is more preferable, and a 1-fold amount or less is further preferable.

<Polyorganosiloxane>
As the polyorganosiloxane of the present invention, a polyorganosiloxane containing an organosiloxane unit represented by the following general formula (1) can be used.
In the general formula (1), R is independently an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group.
Specific examples of the alkyl group include a methyl group, an ethyl group and a propyl group. Specific examples of the cycloalkyl group include a cyclobutyl group, a cyclohexyl group, and an adamantyl group. Specific examples of the aryl group include a phenyl group and a naphthyl group. Specific examples of the heterocyclic group include lactone rings such as γ-lactone group and ε-caprolactone group.

<Organosiloxane>
As the organosiloxane used for producing the polyorganosiloxane, any one of the cyclic diorganosiloxane represented by the following general formula (2) and the chain diorganosiloxane represented by the following general formula (3) alone, or two or more kinds thereof. A mixture can be used.
In the general formula (2), R is independently an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group. n is a natural number from 2 to 10.
In the general formula (3), R is independently an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group. n is a natural number from 2 to 10.

As the diorganosiloxane, dimethylsiloxane is preferable because of its easy availability.
Examples of the dimethylsiloxane include cyclic dimethylsiloxane having a 3-membered ring or more, and those having a 3- to 7-membered ring are preferable. Examples thereof include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane. One of these may be used alone, or two or more thereof may be used in combination.
Considering the ease of controlling the particle size distribution, it is preferable to use octamethylcyclotetrasiloxane as the main component.

In the present invention, a vinyl polymerizable functional group-containing siloxane may be added to the organosiloxane. By adding a vinyl polymerizable functional group-containing siloxane, the polyorganosiloxane can have a polymerizable functional group.
The vinyl polymerizable functional group-containing siloxane is a copolymer of a monomer containing a vinyl polymerizable functional group and capable of binding to dimethylsiloxane via a siloxane bond, and the monomer.

Considering the reactivity with dimethylsiloxane, it is preferable to use various alkoxysilane compounds containing a vinyl polymerizable functional group.
For example, β-methacryloyloxyethyl dimethoxymethylsilane, γ-methacryloyloxypropyldimethoxymethylsilane, γ-methacryloyloxypropylmethoxydimethylsilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropylethoxydiethylsilane, γ-methacryloyl. Methacryloxysilanes such as oxypropyldiethoxyethylsilane and δ-methacryloyloxybutyldiethoxymethylsilane; vinylsiloxanes such as tetramethyltetravinylcyclotetrasiloxane; vinylphenylsilanes such as p-vinylphenyldimethoxymethylsilane; γ-mercapto Examples thereof include mercaptosiloxanes such as propyldimethoxymethylsilane and γ-mercaptopropyltrimethoxysilane.
One of these may be used alone, or two or more thereof may be used in combination.

The amount of the vinyl polymerizable functional group-containing siloxane added is preferably 0.05 times or less, more preferably 0.02 times or less, based on the mass of the organosiloxane, in that the flexible properties of the organosiloxane are not impaired. It is preferable, and the amount of 0.01 times or less is more preferable.

In the present invention, a siloxane-based cross-linking agent may be added to the organosiloxane. By adding a siloxane-based cross-linking agent, a cross-linked site can be formed in the polyorganosiloxane. As the siloxane-based cross-linking agent, trifunctional or tetra-functional silane-based cross-linking agents such as trimethoxymethylsilane, triethoxyphenylsilane, tetramethoxysilane, tetraethoxysilane, and tetrabutoxysilane are used.
The amount of the siloxane-based cross-linking agent added is not particularly limited, but is preferably 0.05 times or less, preferably 0.02 times or less the mass of the organosiloxane, from the viewpoint of not impairing the flexible properties of the organosiloxane. More preferably, 0.01 times or less is further preferable.

<Organosiloxane dispersion of inorganic fine particles>
The inorganic fine particles can be uniformly redispersed in the organosiloxane to form a transparent organosiloxane dispersion that does not cause precipitation. Examples of the method for producing the organosiloxane dispersion liquid of the inorganic fine particles include stirring the inorganic fine particles and the organosiloxane in a reaction vessel equipped with a stirrer or the like.
The ratio of the inorganic fine particles in the organosiloxane dispersion of the inorganic fine particles is preferably 5% by mass or more, more preferably 20% by mass or more, still more preferably 40% by mass or more from the viewpoint of improving the refractive index. Further, from the viewpoint of improving the dispersibility of the inorganic fine particles in the organosiloxane, the ratio of the inorganic fine particles in the organosiloxane dispersion liquid of the inorganic fine particles is preferably 90% by mass or less, more preferably 80% by mass or less, and 70% by mass. The following is more preferable.

<Emulsifier>
As the emulsifier used in the production of polyorganosiloxane, an anionic emulsifier is preferable, and an emulsifier selected from sodium alkylbenzene sulfonate, sodium polyoxyethylene nonylphenyl ether sulfate and the like is used.
Sodium alkylbenzene sulfonate and sodium lauryl sulfate are preferable because of their availability.

From the viewpoint of dispersion stability during polymerization, the amount of emulsifier is preferably 0.1 times or more, more preferably 0.2 times or more, and 0.5 times or more the mass of the organosiloxane dispersion of inorganic fine particles. Is more preferable. Further, from the viewpoint that the refractive index can be increased by reducing the amount of emulsifier, the amount of emulsifier is preferably 10 times or less, more preferably 5 times or less, and further preferably 2 times or less.

<Acid catalyst>
Examples of the acid catalyst used for the polymerization of polyorganosiloxane include sulfonic acids such as aliphatic sulfonic acid, aliphatic substituted benzenesulfonic acid and aliphatic substituted naphthalenesulfonic acid; and mineral acids such as sulfuric acid, hydrochloric acid and nitric acid. One of these may be used alone, or two or more thereof may be used in combination.

The amount of the acid catalyst used is preferably 0.1 times or more, more preferably 0.25 times or more, and 0.5 times the mass of the inorganic fine particles, from the viewpoint of improving the yield during polymerization. The above is more preferable. Further, from the viewpoint that the refractive index can be increased by reducing the amount of the acid catalyst, the amount is preferably 10 times or less, more preferably 5 times or less, and further preferably 1 time or less with respect to the mass of the inorganic fine particles.

<Polymerization>
As a method for producing the above-mentioned polyorganosiloxane, a method of heating and polymerizing an emulsion obtained by pre-stirring a mixture of an organosiloxane dispersion of inorganic fine particles, an emulsifier, an acid catalyst and water, and then neutralizing the acid with an alkaline substance is used. Can be mentioned.
Examples of the method of pre-stirring include a method of atomizing by using a shearing force due to high-speed rotation, a homogenizer which atomizes by the jet output of a high-pressure generator, and the like. Among them, the method using a homogenizer is preferable because the distribution of the particle size of the polyorganosiloxane latex is narrowed.

The polymerization temperature is preferably 50 ° C. or higher, more preferably 70 ° C. or higher. The polymerization time is preferably 2 hours or more, more preferably 5 hours or more.
The polymerization can be stopped by cooling the reaction solution and neutralizing the latex with an alkaline substance such as caustic soda, caustic potash, or sodium carbonate.

Hereinafter, the present invention will be described with reference to Examples. However, the present invention is not limited to the following examples. In the following, "part" means "part by mass". The average particle size and the refractive index were evaluated by the following methods.

(1) Average particle size The average particle size obtained by measuring at 25 ° C. using a dynamic light scattering photometer (manufactured by Otsuka Electronics Co., Ltd., trade name: ELS-800) and analyzing by the cumulant method was used.

(2) Refractive index About 1 mL of latex containing particles was dropped onto a PET film and dried in a dryer at 40 ° C. for 24 hours to obtain a film. The refractive index of this film was measured using a prism coupler refractive index meter (manufactured by Metricon, trade name: 2010 / M prism coupler).

[Production Example 1] Hydrophobicization Treatment of Zirconium Oxide Fine Particles Lauric acid (manufactured by Wako Pure Chemical Industries, Ltd.) is a hydrophobizing agent so as to be 30% by mass with respect to the processed zirconium oxide fine particles in a eggplant flask in which a stirrer chip is set. ) Was weighed in 30 parts. Toluene (manufactured by Wako Pure Chemical Industries, Ltd.) (750 parts) as a water-insoluble organic solvent, 83 parts of methanol (manufactured by Wako Pure Chemical Industries, Ltd.), which is an amphoteric organic solvent, are added, and zirconium oxide fine particle methanol dispersion (manufactured by Sakai Chemical Industries, Ltd. Product name: SZR-M, zirconium oxide content: 30% by mass, average particle size: 13.2 nm) 333 parts were added and mixed.
The mixed solution obtained above was stirred at room temperature for 1 hour, and then the dispersion medium was evaporated and removed by a rotary evaporator. Evaporation and removal of the dispersion medium was carried out by reducing the pressure of the atmosphere to a pressure that does not cause bumping in the liquid phase while keeping the mixed solution at room temperature.
About 100 parts of toluene was further added to the mixed solution remaining in the eggplant flask after the first evaporation and removal of the dispersion medium, and the operation of evaporation was performed again. By repeating this operation approximately 2 to 3 times, the dispersion liquid was changed from a cloudy state to a colorless and transparent state, and the remaining liquid phase became a single phase. As a result, a toluene dispersion of zirconium oxide fine particles was obtained.
Toluene was evaporated and removed by evaporation and then vacuum dried at room temperature for 8 hours to obtain a powder composed of zirconium oxide fine particles. The zirconium oxide fine particles subjected to the above hydrophobization treatment could be redispersed in organosiloxane.

[Example 1] Fine particle-containing polyorganosiloxane latex (L-1)
30 parts of the zirconium oxide fine particles hydrophobized in Production Example 1 were dispersed with respect to 69.6 parts of octamethylcyclotetrasiloxane to obtain a transparent organosiloxane dispersion of zirconium oxide fine particles. 0.4 part of γ-methacryloyloxypropyldimethoxymethylsilane was mixed with the above dispersion to obtain 100 parts of a siloxane-based mixture. To this, 200 parts of distilled water in which 15 parts of dodecylbenzenesulfonic acid and 1 part of sodium dodecylbenzenesulfonic acid were dissolved was added, and an ultrasonic homogenizer was used for 15 minutes to obtain a stable premixed organosiloxane emulsion. The above emulsion was placed in a three-necked flask equipped with a cooling condenser, heated to 80 ° C., polymerized at a temperature of 5 hours, and cooled. The reaction was then held at room temperature for 48 hours and then neutralized with aqueous caustic soda.

When the latex thus obtained was dried at 180 ° C. for 30 minutes to determine the solid content, it was 27.3% by mass. The average particle size of the latex was 138 nm. The refractive index of the film obtained by drying the latex was 1.46, which was 1.46. By containing the zirconium oxide fine particles, the refractive index was improved as compared with the polyorganosiloxane containing no zirconium oxide fine particles shown below. did.

[Example 2] Fine particle-containing polyorganosiloxane latex (L-2)
A fine particle-containing polyorganosiloxane latex (L-2) was obtained in the same manner as in Example 1 except that the composition was changed to that shown in Table 1.
The latex was dried at 180 ° C. for 30 minutes to determine the solid content, which was 25.9% by mass, and the average particle size was 180 nm. In addition, the refractive index was 1.52, and by containing the zirconium oxide fine particles, the refractive index was improved as compared with the polyorganosiloxane containing no zirconium oxide fine particles shown below.

[Comparative Example 1] Polyorganosiloxane Latex (L-3)
A polyorganosiloxane latex (L-3) was obtained in the same manner as in Example 1 except that the composition was changed to that shown in Table 1.
The solid content of the latex was determined to be 25.8% by mass, and the average particle size was 247 nm. The refractive index was 1.40, which was lower than that of polyorganosiloxane containing zirconium oxide fine particles.

Claims (7)

Inorganic fine particles are organic-inorganic composite particles in which inorganic fine particles are dispersed in a polyorganosiloxane containing an organosiloxane unit represented by the following general formula (1), and the inorganic fine particles are zirconium oxide, titanium oxide, tin oxide, alumina, and the like. Organic-inorganic composite particles that are compounds selected from the group consisting of magnesium oxide, antimony oxide and calcium oxide.

(In formula (1), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively.) An organic-inorganic composite particle latex containing the organic-inorganic composite particle according to claim 1. A method for producing an organic-inorganic composite particle latex in which inorganic fine particles are dispersed in a polyorganosiloxane containing an organosiloxane unit represented by the following general formula (1).
The polyorganosiloxane is obtained by polymerizing an organosiloxane.
A method for producing an organic-inorganic composite particle latex in which the inorganic fine particles are a compound selected from the group consisting of zirconium oxide, titanium oxide, tin oxide, alumina, magnesium oxide, antimony oxide and calcium oxide.
(In formula (1), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively.) Claim that the organosiloxane is one or more selected from the group composed of the cyclic diorganosiloxane represented by the following general formula (2) and the chain-shaped diorganosiloxane represented by the following general formula (3). 3. The method for producing an organic-inorganic composite particle latex according to 3.

(In formula (2), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively. N is a natural number of 2 to 10.)

(In formula (3), R is an alkyl group, a cycloalkyl group, an aryl group or a heterocyclic group, respectively. N is a natural number of 2 to 10). A method for producing an organic-inorganic composite particle latex, in which an emulsion obtained by pre-stirring a mixture of an organosiloxane dispersion of inorganic fine particles, an emulsifier, an acid catalyst, and water is heated and polymerized.
One or more selected from the group in which the organosiloxane dispersion of the inorganic fine particles is composed of the cyclic diorganosiloxane represented by the general formula (2) and the chain-shaped diorganosiloxane represented by the general formula (3). The method for producing an organic-inorganic composite particle latex according to claim 4 , wherein the inorganic fine particles are dispersed in the organosiloxane of the above. The method for producing an organic-inorganic composite particle latex according to claim 5 , wherein the amount of the acid catalyst added is 0.25 times or more the mass of the inorganic fine particles. A carboxylic acid having 4 or more carbon atoms is mixed with an aqueous dispersion in which inorganic fine particles are dispersed in water, and then water is removed to hydrophobize the inorganic fine particles.
The method for producing an organic-inorganic composite particle latex according to claim 5 or 6 , wherein the hydrophobized inorganic fine particles are dispersed in the organosiloxane to obtain an organosiloxane dispersion liquid of the inorganic fine particles.