JP2002179806A - Resin particle, method for producing thereof and application thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce fine particles of a resin capable of being homogeneously dispersed when added to a substrate resin and excellent in affinity to a binder resin when used as a paint. SOLUTION: The fine resin particles are obtained by polymerizing a (meth) acrylic ester monomer and forming a coated film on the surface of the particles with a coupling agent comprising a silane-based compound having a polymerizable vinyl group and a coupling agent comprising one or more of species selected from a titanate-based compound, an aluminate-based compound, a zirconate-based compound and a silane-based compound having no polymerizable vinyl group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to resin fine particles and a method for producing the same, and more particularly, to a resin fine particle which is uniformly dispersed when added to a base resin, and has an affinity for a binder resin when formed into a paint. Resin fine particles which are excellent in sedimentation, hardly settle out in the coating composition, and hardly fall off from the coated film after coating, a method for producing the resin fine particles, a coating composition containing the resin fine particles, and the coating composition And to a coated product obtained by applying

[0002]

2. Description of the Related Art Fine resin particles produced by suspension polymerization are widely used in place of inorganic particles as matting agents for paints, lubricants for cosmetics, additives for improving the physical properties of resins, light diffusing agents, and the like. Is used in various fields. In general, inorganic particles used as additives for synthetic resins or matting agents for paints enhance the affinity with the resin as the base material to improve the uniformity of dispersion, and the resulting molded products and coated products It is known that the surface is treated with an organic compound such as a surfactant and a higher fatty acid or various coupling agents in order to improve physical properties, appearance, and the like.

However, even the inorganic particles subjected to the above-mentioned surface treatment still have insufficient affinity with the base resin. On the other hand, the resin fine particles have a higher affinity with the base resin, for example, when added to the base resin, can effectively improve intended physical properties such as impact resistance and slipperiness. This has the effect of increasing transparency.
In addition, when added to the paint, the coating film after coating is prevented from being damaged, and furthermore, effects such as reduction of detachment of resin fine particles from the coating film are brought about. However, even with such resin fine particles, for example, in order to suppress the sedimentation of the resin fine particles in the coating composition and further reduce the falling of the resin fine particles from the coating film, further improvement in affinity is required. .

[0004]

To cope with such a situation, Japanese Patent Application Laid-Open No. Hei 10-273503 discloses that an amino-modified silicone is dispersed in an organic solvent in which a monomer is dissolved but a produced polymer is insoluble. A method for producing polymer fine particles having a hydrophobic surface useful for a paint or the like by dispersing and polymerizing a monomer using the method has been proposed. However, according to this method, a part of the amino-modified silicone used as a dispersion stabilizer makes the surface of the resin particles hydrophobic, but the obtained resin particles do not have sufficient affinity for the amino-modified silicone remaining on the surface. In addition, it is difficult to obtain crosslinked polymer fine particles, the efficiency is low because a large amount of amino-modified silicone is used as compared with the amount when treating the particle surface, and the step of recovering amino-modified silicone with an organic solvent. There are many problems, such as the increase in the number and complexity. An object of the present invention is to provide a resin fine particle having excellent dispersibility by efficiently forming a strong coating with a coupling agent on the surface of the resin fine particle by a simple method, and a method of producing and using the same. .

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the surface of (meth) acrylate-based resin fine particles was coated with two or more specific coupling agents. It has been found that the formation of the resin has extremely good affinity of the fine resin particles for the base resin, and the present invention has been completed.

That is, according to the present invention, there are provided resin fine particles obtained by polymerizing a (meth) acrylic acid ester monomer, wherein the coupling agent comprises a silane compound having a polymerizable vinyl group; A coupling agent comprising at least one compound selected from a compound, an aluminate compound, a zirconate compound and a silane compound having no polymerizable vinyl group (hereinafter referred to as “a specific combination of The ringing agent) provides resin fine particles having a film formed on the surface of the resin fine particles.

Further, resin fine particles obtained by polymerizing a (meth) acrylate monomer are suspended in an aqueous medium,
A method for producing resin fine particles, characterized by adding a specific combination of coupling agents in the presence of a radical polymerization initiator and heating the mixture. Further, there are provided a coating composition comprising the resin fine particles and a coating product obtained by applying the coating composition.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The resin fine particles of the present invention in which a film is formed on the surface of the resin fine particles by a coupling agent are prepared by dispersing a (meth) acrylate monomer in an aqueous medium containing a dispersion stabilizer. The resin particles obtained by suspension polymerization in the presence of a polymerization initiator are redispersed in an aqueous medium, and a specific combination of coupling agents is added thereto and heated, or the above-mentioned suspension polymerization is carried out. In this case, it is obtained by adding a specific combination of coupling agents and polymerizing.

[0009] Examples of (meth) acrylic ester monomers include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and lauryl. (Meth) acrylate, stearyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxyethyl (meth) acrylate, diethylene glycol mono Examples include (meth) acrylate, methoxyethyl (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, and isobornyl (meth) acrylate.

[0010] The (meth) acrylate monomer is
Depending on the purpose of the modification or the like, other monomers copolymerizable with the (meth) acrylate-based monomer can be used in combination within a range that does not impair the effects of the present invention. Such other monomers include, for example, alkylstyrenes such as styrene, methylstyrene, dimethylstyrene, trimethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene;
Fluorostyrene, chlorostyrene, bromostyrene,
Dibromostyrene, iodide styrene; nitrostyrene,
Acetyl styrene, styrene monomers such as substituted styrenes such as methoxy styrene, vinyl pyridines, vinyl pyrrolidone, vinyl carbazole, vinyl monomers such as vinyl acetate, butadiene, isoprene, conjugated diene compounds such as chloroprene, vinyl chloride, Examples thereof include vinylidene halides such as vinyl bromide, and nitrile group-containing unsaturated compounds such as acrylonitrile.

Further, for example, methyl (meth) acrylic acid,
α-ethyl (meth) acrylic acid, crotonic acid, α-methyl crotonic acid, α-ethyl crotonic acid, isocrotonic acid, tiglic acid, ungeric acid; maleic acid, fumaric acid, itaconic acid, citraconic acid, mesaconic acid, glutaconic acid Further, an addition-polymerizable unsaturated aliphatic carboxylic acid such as hydromuconic acid may be used as another copolymerizable monomer. Further, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate ) Acrylate,
Two or more of 1,1,1-trihydroxymethylmethane triacrylate, 1,1,1-trihydroxymethylethane triacrylate, 1,1,1-trihydroxymethylpropane triacrylate, divinylbenzene, trivinylbenzene and the like When a polyfunctional vinyl monomer having the above functional group is used in combination as another copolymerizable monomer, the effect of improving the solvent resistance of the finally obtained resin fine particles can be obtained.

The monomers to be used in combination can be used alone or in combination of two or more. The proportion of the monomers added is preferably about 1 to 50% by weight of the whole monomers, and 3 to 30% by weight. The degree is more preferred. The polymerization initiator is not particularly limited, and for example, azo compounds such as 2,2′-azobis (2,4-dimethylvaleronitrile) and azoisobisbutyronitrile; dilauroyl peroxide, dibenzoyl peroxide, t Organic peroxides such as -butyl peroxide and 2-ethylhexanoate, which are well known for radical polymerization, can be used.

These polymerization initiators can be used alone or in combination of two or more kinds. The addition ratio thereof is not particularly limited, but is usually about 0.01 to 3% by weight of the whole monomer. is there. The dispersion stabilizer is not particularly limited, for example, polyvinyl alcohol, methyl cellulose,
Well-known compounds such as water-soluble polymer compounds such as hydroxyethyl cellulose and sodium polyacrylate, and poorly water-soluble inorganic salts such as tribasic calcium phosphate, magnesium hydroxide, magnesium pyrophosphate and barium sulfate can be used. Among them, the poorly water-soluble inorganic salt is preferable because it can be easily removed from the surface of the resin fine particles obtained after the polymerization, and the particle size distribution of the generated resin fine particles can be narrowed.

Although the addition ratio of the dispersion stabilizer is not particularly limited, it is usually about 0.1 to 20 parts by weight per 100 parts by weight of the finally obtained resin fine particles. In suspension polymerization,
A surfactant can be used together with the dispersion stabilizer.
For example, when a poorly water-soluble inorganic salt is used as the dispersion stabilizer, an anionic surfactant is preferably used. The anionic surfactant is not particularly limited, and those used in suspension polymerization can be used.Examples thereof include sodium dodecyl sulfate, sodium dodecyl benzene sulfonate, sodium polyoxyethylene lauryl ether sulfate, and sodium dioctyl sulfosuccinate. And the like. The addition ratio of such an anionic surfactant is not particularly limited, but is usually about 0.005 to 0.3% by weight based on the aqueous medium used for the polymerization reaction.

[0015] The temperature and time during suspension polymerization are controlled by a polymerization initiator,
It is appropriately set according to the type of the monomer, but is usually 40 to
It is about 0.5 to 10 hours at about 100 ° C., and preferably about 1 to 5 hours at about 50 to 90 ° C. After completion of the polymerization reaction, the resin fine particles are separated from the aqueous medium by filtration, centrifugation, etc., washed with water, and dried to obtain resin fine particles. The average particle diameter of the obtained resin fine particles is usually 1 to 100 μm.
The particle size can be adjusted to a desired value by appropriately setting the type and amount of the dispersion stabilizer or surfactant, the stirring conditions, and the like.

In the resin fine particles of the present invention, a film is formed on the surface of the resin fine particles obtained by polymerizing the (meth) acrylate monomer as described above, using a specific combination of coupling agents. It is. Examples of the coupling agent comprising a silane-based compound having a polymerizable vinyl group, which is one component of the coupling agent of a specific combination, include vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, and γ-methacrylic acid. Roxypropyltrimethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltriethoxysilane, and the like.

Among the other components, examples of the coupling agent comprising a titanate compound include isopropyl triisostearoylated titanate, tetraoctyl bis (ditridecyl phosphite) titanate, bis (dioctyl pyrophosphate) oxyacetate titanate, Isopropyl tridodecyl benzene sulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetra (2,
2-diallyloxymethyl-1-butyl) bis- (ditridecyl) phosphite titanate, bis (dioctylpyrophosphate) ethylene titanate, isopropyltrioctanoyl titanate, isopropyldimethacrylisostearoyl titanate, isopropyltristearoyldiacryl titanate, isopropyltriate (Dioctyl phosphate) titanate, isopropyltricumylphenyl titanate, dicumylphenyloxyacetate titanate, diisostearoylethylene titanate and the like can be mentioned.

Examples of the coupling agent comprising an aluminate compound include acetoalkoxyaluminum diisopropylate. Examples of the coupling agent composed of a zirconate-based compound include acetoalkoxyzirconium diisopropionate and a compound represented by the following formula.

[0019]

Embedded image[Wherein X is-(CH_Two)_TwoNH_Two,-(CH_Two)_FourCOO
H,-(CH_Two)₁₂CH _ThreeOr -C (CH_Three) = CH_Twoso
is there]

As the coupling agent comprising a silane compound having no polymerizable vinyl group, for example, 2-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl)-
3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-
Examples include aminopropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, isobutyltrimethoxysilane, dimethyldimethoxysilane, and methyltrimethoxysilane.

The addition ratio of the coupling agent in a specific combination is appropriately set depending on the particle diameter of the resin fine particles. It is preferably about 0.05 to 5 parts by weight, more preferably about 0.1 to 3 parts by weight.
If the addition ratio of the coupling agent in the specific combination is less than 0.05 part by weight, sufficient affinity for the base resin cannot be obtained, and practical properties balanced in mechanical properties and chemical properties are not obtained. It is not preferable because it is difficult to obtain effective resin fine particles. On the other hand, if the addition ratio of the coupling agent in a specific combination exceeds 5 parts by weight, the effect corresponding to the addition cannot be obtained, which is not preferable.

The ratio of the combination in the specific combination of the coupling agent includes a coupling agent comprising a silane compound having a polymerizable vinyl group and a coupling agent comprising a titanate compound, an aluminate compound, a zirconate compound and a polymerizable vinyl group. 1: 9 in weight ratio with a coupling agent of at least one kind selected from silane compounds not used
9 to 99: 1, more preferably 20:80 to 8
0:20, more preferably 30:70 to 70:30. In the above weight ratio, if one of the coupling agents is less than 1, sufficient affinity for the base resin cannot be obtained.

As the coupling agent, a coupling agent composed of a silane compound having a radically polymerizable vinyl group alone, or a titanate compound, an aluminate compound, a zirconate compound, or a silane having no radically polymerizable vinyl group can be used. Sufficient effects cannot be obtained even when a coupling agent composed of at least one or more compounds selected from the series compounds is used alone, and by using the coupling agent of the specific combination of the present invention, Excellent affinity is obtained. The formation of a film on the surface of the resin fine particles by a specific combination of the coupling agent is performed, for example, by dispersing the resin fine particles obtained by the above-mentioned suspension polymerization, washed with water, and dried in an aqueous medium. Or by adding a coupling agent to the above-mentioned suspension polymerization system.

In the former method, in order to form a uniform film on the surface of the fine resin particles in an aqueous medium, it is preferable to add a specific combination of coupling agents in the form of an emulsion with an anionic surfactant or the like. . As the anionic surfactant, the same one as described above can be used. In the latter method, the formation of a film on the surface of the resin fine particles is performed by simultaneously or separately adding a specific combination of coupling agents to a reaction system containing a radical polymerization initiator and heating. in this way,
When the polymerization conversion of the monomer used in the suspension polymerization becomes 95% or more, a specific combination of coupling agents is added to the suspension polymerization system, and the polymerization of the monomer and the formation of a film are simultaneously performed. This is preferable because the manufacturing process can be simplified. To efficiently form a more uniform coating, add a silane coupling agent having a polymerizable vinyl group first, adsorb it to the resin fine particles to form a coating, and then add the remaining coupling agent. Then, it is preferable to form a coating film by adsorbing the resin fine particles.

The heat treatment after the addition of each coupling agent is performed at a temperature of 80 ° C. or higher, more preferably 90 ° C. or higher. Among the resin fine particles of the present invention, in that the affinity with the base resin is extremely good,
When 0.1 g of resin fine particles are spread on the liquid surface of 50 ml of distilled water and methanol is dropped under slow stirring such that vortex and turbulence do not occur on the liquid surface, all the resin fine particles wet the liquid and The amount of added methanol A (ml) when completely settled in the sample was measured, and the formula: wettability value = (14.49 × A + 1171.5) / (A +
50) Those having a wettability value of 23 or less are preferable, and
Those having 8 to 22.5 are more preferred.

The coating composition of the present invention is obtained by adding the resin fine particles having the film formed thereon as described above in a resin binder to an organic solvent. The resin binder is not particularly limited, and a thermoplastic, thermosetting or photocurable resin can be used.Specifically, for example, acrylic resin, polyester resin, polyvinyl chloride, polyurethane, silicone resin, melamine Resins. In this coating composition, sedimentation of resin fine particles is suppressed,
Stable for long periods.

When light transmittance after coating is expected, a transparent resin such as an acrylic resin or a polyester resin is preferably used. The coating composition of the present invention may contain various known additives such as a leveling agent, a surface modifier, a defoaming agent, and a coloring agent such as a pigment. The coating composition is a known method, for example, after dissolving a resin binder in an organic solvent, adding the resin fine particles of the present invention, using a sand mill, a ball mill, an attritor, a high-speed rotary stirrer, a three-roll, etc. It can be manufactured by a method of mixing and dispersing.

The organic solvent is not particularly limited as long as it dissolves the resin binder. For example, toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (ethyl Cellosolve), ethyl acetate, butyl acetate, isopropyl alcohol, acetone, anisole and the like. These organic solvents can be used alone or
More than one species can be used in combination. The coated product of the present invention is obtained by applying the above-mentioned coating composition. This coated product is preferable because the resin particles can be easily removed. The coating method of the coating composition is not particularly limited,
For example, a known method such as a spray method, a bar coating method, a doctor blade method, a roll coating method, a spin coating method or a dipping method can be used. After applying the coating composition by these methods, the coating composition is dried to remove the organic solvent, thereby obtaining a coated product.

[0029]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by these Examples. The measurement of the wettability value, the evaluation of the sedimentation property, and the measurement of the detachability of the resin fine particles in the examples were performed by the following methods.

[Measurement of wettability value] 0.1 g of resin microparticles are sprayed on a liquid surface of 50 ml of distilled water in a 100 ml glass beaker (inner diameter of about 50 mm), spread and floated, and a stirrer having a length of 30 mm is used. About 5 with a magnetic stirrer
At 00 rpm, methanol is added dropwise while stirring slowly so as not to cause vortex or turbulence on the liquid surface. The end point is when all the resin particles are completely wetted with the liquid and completely settled in the liquid,
The amount of added methanol A (ml) at that time is measured. The wettability value is calculated by substituting the added methanol amount A into the following equation. Wettability value = [(14.49 × A) + (50 × 23.4)
3)] / (A + 50) Solubility parameter value of water = 23.43 Methanol solubility parameter value = 14.49 Methanol dropping amount = A ml

[Evaluation of Sedimentation Property] A coating composition was prepared according to the following formulation, and after standing for 72 hours, the sedimentation state of the resin fine particles was observed. When the sedimentation was partially settled, and when no sedimentation was observed, it was marked as ○. Composition of paint Binder resin Byron 200 (Polyester manufactured by Toyobo Co., Ltd.) 50.0 parts by weight Resin fine particles 7.0 parts by weight Toluene 100.0 parts by weight Methyl ethyl ketone 20.0 parts by weight

[Measurement of detachability of resin fine particles] A coating composition having the above composition was applied to a black-and-white concealment test paper with an applicator having a wet thickness of 100 μm.
Dried in oven at ℃. The surface of the dried coating film was rubbed 20 times with a black cloth, and a large amount of white resin fine particles that fell off the coating film and adhered to the cloth were observed. Was evaluated as ○.

Example 1 3 kg of water was put into a 5 liter stainless steel autoclave equipped with a stirrer, 80 g of tribasic calcium phosphate was added and dispersed with stirring, and 1.2 g of sodium dodecyl sulfate was added and dissolved. , An aqueous medium was prepared.
Separately, to 544 g of methyl methacrylate, 16 g of trimethylolpropane trimethacrylate and 5 g of azoisobisbutyronitrile were added and dissolved to obtain a monomer composition. This monomer composition was placed in the above aqueous medium, and a TK-homomixer manufactured by Tokushu Kika Co., Ltd. was used.
It was finely dispersed in droplets of the order. Thereafter, the temperature was raised to 60 ° C. under a nitrogen stream under stirring at 200 rpm, and the polymerization was carried out by keeping the temperature for 8 hours. The polymerization conversion rate after holding for 8 hours is 97%,
The volume average particle diameter of the obtained resin fine particles was 8.3 μm.

Next, this dispersion was heated to 70 ° C., and separately added to 5 g of γ-methacryloxypropyltrimethoxysilane and 4 g of isobutyltrimethoxysilane in 20 g of water in which 0.1 g of sodium dodecyl sulfate was dissolved. And a mixture of 0.05 g of benzoyl peroxide,
Using an ultrasonic homogenizer, an emulsion finely dispersed until the particle diameter of the oil droplets became 2 μm was added. After maintaining the dispersion at 70 ° C. for 5 hours, the temperature was increased to 100 ° C.
After holding for 3 hours, polymerization and formation of a film on the surface of the resin fine particles were completed. After cooling the reaction solution and adding hydrochloric acid to completely dissolve the tricalcium phosphate, the resin fine particles were collected by filtration,
It was washed with water, dehydrated, and dried in an oven at 60 ° C. overnight to obtain resin fine particles on which a film was formed. The wettability value, sedimentation property, and shedding property of the resin fine particles were evaluated. Table 1 shows the results.

Example 2 3 kg of water was placed in a 5 liter stainless steel autoclave equipped with a stirrer, 80 g of tribasic calcium phosphate was added and dispersed with stirring, and 1.2 g of sodium dodecyl sulfate was dissolved to prepare an aqueous medium. Prepared. Separately, a monomer composition was prepared by dissolving 16 g of trimethylolpropane trimethacrylate and 5 g of azoisobisbutyronitrile in 544 g of methyl methacrylate.
This monomer composition was added to the above aqueous medium, and finely dispersed into droplets of about 7 μm using a TK-homomixer manufactured by Tokushu Kika Co., Ltd. Thereafter, the temperature was raised to 70 ° C. under a nitrogen stream under stirring at 200 rpm, and the polymerization was carried out by keeping the temperature for 8 hours. 8
The polymerization conversion rate after the time polymerization was 97%, and the volume average particle diameter of the obtained resin fine particles was 6.3 μm.

Next, 4 g of γ-methacryloxypropyltrimethoxylane, 4 g of acetoalkoxyaluminum diisopropylate and 0.05 g of benzoyl peroxide were mixed in 20 g of water in which 0.1 g of sodium dodecyl sulfate was dissolved. The liquid was charged, and an emulsion finely dispersed using an ultrasonic homogenizer until the particle diameter of the oil droplets became 2 μm was added. This dispersion is
After keeping at 5 ° C. for 5 hours, the temperature was raised to 100 ° C. and kept for 3 hours to complete the polymerization and the formation of the resin fine particle film. After cooling the reaction solution and adding hydrochloric acid to completely dissolve the tricalcium phosphate, the resin fine particles are collected by filtration, washed with water, and dehydrated.
It was dried in an oven at 60 ° C. overnight to obtain resin fine particles on which a film was formed. Table 1 shows the results of the evaluation performed on the resin fine particles.

Example 3 3 kg of water was placed in a stainless steel autoclave having an internal volume of 5 liters and equipped with a stirrer, 80 g of tribasic calcium phosphate was added and dispersed with stirring, and 1.2 g of sodium dodecyl sulfate was dissolved to prepare an aqueous medium. Prepared. Separately, 16 g of trimethylolpropane trimethacrylate and 5 g of azoisobisbutyronitrile were dissolved in 544 g of methyl methacrylate to prepare a monomer mixture. This monomer mixture was added to the aqueous medium, and finely dispersed into droplets of about 12 μm using a TK-homomixer manufactured by Tokushu Kika Co., Ltd. Thereafter, the temperature was raised to 70 ° C. under a nitrogen stream under stirring at 200 rpm, and the polymerization was carried out by keeping the temperature for 8 hours. 8
The polymerization conversion after the time polymerization was 95%, and the volume average particle diameter of the obtained resin fine particles was 11.3 μm.

Next, 6 g of γ-methacryloxypropyltrimethoxysilane and tetra (2,5) were added to 30 g of water in which 0.15 g of sodium dodecyl sulfate was dissolved.
An emulsion in which a mixed solution of 6 g of 2-diallyloxymethyl-1-butyl) bis- (ditridecyl) phosphite titanate and 0.05 g of benzoyl peroxide is finely dispersed using an ultrasonic homogenizer until the oil droplets have a particle diameter of 2 μm. Was added. After the dispersion was maintained at 70 ° C. for 5 hours, the temperature was raised to 100 ° C., and the temperature was maintained for 3 hours to complete the polymerization and the formation of a film of the resin fine particles. After the reaction solution was cooled and hydrochloric acid was added to completely dissolve the tricalcium phosphate, the resin fine particles were washed with water, dehydrated, and dried in an oven at 60 ° C. overnight to obtain resin fine particles on which a film was formed. Table 1 shows the results of the evaluation performed on the resin fine particles.

Example 4 After charging a separately prepared emulsion,
Resin fine particles were obtained in the same manner as in Example 1 except that polymerization was performed at 70 ° C. for 6 hours instead of performing polymerization for hours. Table 1 shows the evaluation results of the resin fine particles.

Comparative Example 1 Resin fine particles were obtained in the same manner as in Example 1 except that no separately prepared emulsion was added. Table 1 shows the evaluation results of the resin fine particles. Comparative Example 2 Resin fine particles were obtained in the same manner as in Example 1 except that isobutyltrimethoxysilane was not added to the separately prepared emulsion. Table 1 shows the evaluation results of the resin fine particles. Comparative Example 3 Example 1 was repeated except that γ-methacryloxypropyltrimethoxysilane was not added to the separately prepared emulsion.
Resin fine particles were obtained in the same manner as described above. Table 1 shows the evaluation results of the resin fine particles.

[0041]

[Table 1]

[0042]

According to the present invention, a coupling agent composed of a silane compound having a polymerizable vinyl group on the particle surface, and a coupling agent selected from a titanate compound, an aluminate compound, a zirconate compound, and a silane compound having no polymerizable vinyl group. (Meth) acrylate-based resin fine particles, in particular, resin fine particles having a wettability value of 23 or less, having a coating formed with at least one type of coupling agent, have an affinity for the resin as the base material. Very good. By blending the resin fine particles into the coating composition, the sedimentation of the resin fine particles is suppressed, and in the coated product obtained by applying the coating composition, it is possible to improve the detachability of the resin fine particles from the coating film. it can.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F070 AA32 AB09 AC36 AC52 AC63 AC74 AE27 DB03 DC02 DC06 DC13 4J011 PA25 PA47 PA69 PB40 PC02 PC07 4J038 CD031 CG141 CG142 CL002 DA161 DD001 DG001 DL031 EA011 FA212 JA23 JC32 KA03 J08 NA01 NA11

Claims (5)

[Claims] 1. A resin fine particle obtained by polymerizing a (meth) acrylate monomer, comprising a coupling agent comprising a silane compound having a polymerizable vinyl group, a titanate compound, and an aluminate compound. Resin fine particles, wherein a film is formed on the particle surface with a coupling agent comprising at least one selected from a zirconate compound and a silane compound having no polymerizable vinyl group. 2. When 0.1 g of resin fine particles are spread on a liquid surface of 50 ml of distilled water and methanol is dropped under slow stirring such that vortex and turbulence do not occur on the liquid surface, all the resin fine particles are removed. Based on the amount of added methanol A (ml) when wet and completely settled in the liquid, the formula: wettability value = (14.49 × A + 1171.5) / (A +
50. The resin fine particles according to claim 1, wherein the wettability value calculated by the above is not more than 23. 3. A resin fine particle obtained by polymerizing a (meth) acrylic ester monomer is suspended in an aqueous medium, and a silane compound having a polymerizable vinyl group is suspended in the presence of a radical polymerization initiator. Adding a coupling agent and at least one coupling agent selected from a titanate compound, an aluminate compound, a zirconate compound and a silane compound having no polymerizable vinyl group, and heating. Characteristic method for producing resin fine particles. 4. A coating composition comprising the resin fine particles according to claim 1 or 2. 5. A coated article obtained by applying the coating composition according to claim 4.