阅读说明：本技术 空心颗粒分散体 (Hollow particle dispersion ) 是由 片山悠吾 松浦春彦 野田百夏 大内卓太 于 2019-03-13 设计创作，主要内容包括：一种空心颗粒分散体,其含有：具有由至少一个以上的层形成的壳的空心颗粒、酸性化合物和有机溶剂,前述层的至少一者含有氮原子和碳原子,前述酸性化合物的含量相对于前述空心颗粒与前述酸性化合物的总计100质量份为0.01～70质量份,前述空心颗粒的含量相对于前述空心颗粒分散体100质量份为0.01～30质量份。(A hollow particle dispersion comprising: the hollow particles comprise a shell formed by at least one layer, at least one of the layers contains a nitrogen atom and a carbon atom, the content of the acidic compound is 0.01-70 parts by mass relative to 100 parts by mass of the total of the hollow particles and the acidic compound, and the content of the hollow particles is 0.01-30 parts by mass relative to 100 parts by mass of the hollow particle dispersion.)

1. A hollow particle dispersion comprising: hollow particles having a shell formed of at least one or more layers, an acidic compound, and an organic solvent,

at least one of the layers contains nitrogen atoms and carbon atoms,

the content of the acidic compound is 0.01-70 parts by mass relative to 100 parts by mass of the total of the hollow particles and the acidic compound, and the content of the hollow particles is 0.01-30 parts by mass relative to 100 parts by mass of the hollow particle dispersion.

2. The hollow particle dispersion according to claim 1, wherein the acidic compound shows an acid value of 10 to 300 mgKOH/g.

3. The hollow particle dispersion according to claim 1 or 2, wherein the hollow particles show an average particle diameter of 30 to 120nm, showing a hollow rate of 10 to 70%.

4. The hollow particle dispersion according to any one of claims 1 to 3, wherein a presence ratio N of nitrogen atoms to a presence ratio C of carbon atoms in the XPS measurement of the hollow particles satisfies a relationship of 0.01. ltoreq.N/C.ltoreq.0.2.

5. The hollow particle dispersion according to any one of claims 1 to 4, wherein at least one of the layers contains silicon atoms and carbon atoms, and a presence ratio of silicon atoms Si to carbon atoms C in XPS measurement of the hollow particles satisfies a relationship of 0.001. ltoreq. Si/C. ltoreq.0.1.

6. The hollow particle dispersion according to any one of claims 1 to 5, wherein the hollow particles are 810cm in an infrared absorption spectrum measured by ATR-FTIR^-1Absorbance (A810) and 1720cm^-1The absorbance ratio alpha (absorbance ratio alpha: A810/A1720) of (A1720) shows an absorbance ratio alpha of 0.015 to 0.50.

7. The hollow particle dispersion according to any one of claims 1 to 6, wherein the acidic compound is selected from the group consisting of an inorganic acid, a carboxylic acid compound, an alkyl ester compound of an acid, a sulfonic acid compound, a phosphate ester compound, a phosphonic acid compound, and a phosphinic acid compound.

8. The hollow particle dispersion according to any one of claims 1 to 7, wherein the organic solvent is selected from an alcohol-based solvent, a ketone-based solvent, an ester-based solvent, a glycol ether-based solvent, and a glycol ester-based solvent.

9. A coating agent comprising the hollow particle dispersion according to any one of claims 1 to 8.

10. A hollow particle dispersion for a heat insulating film, which uses the hollow particle dispersion as claimed in any one of claims 1 to 8 for a heat insulating film.

11. An antireflection film and a dispersion of hollow particles for an antireflection film-equipped substrate, wherein the dispersion of hollow particles described in any one of claims 1 to 8 is used for an antireflection film and an antireflection film-equipped substrate.

12. A light extraction film and a hollow particle dispersion for a substrate with a light extraction film, wherein the hollow particle dispersion according to any one of claims 1 to 8 is used for the light extraction film and the substrate with the light extraction film.

13. A hollow particle dispersion for a low dielectric constant film, which uses the hollow particle dispersion as defined in any one of claims 1 to 8 for a low dielectric constant film.

Technical Field

The present invention relates to a hollow particle dispersion. According to the hollow particle dispersion of the present invention, a cured product having high dispersibility in a curable resin and having abrasion resistance and high transparency by curing a curable resin composition containing hollow particles can be obtained.

Background

Particles having voids inside can be used as microcapsule particles by incorporating various substances into the voids. These particles having voids therein are also referred to as hollow particles, and can be used as a light scattering material, a low reflection material, a heat insulating material, a low dielectric constant material, or the like. These materials can be used as a light scattering film, a low reflection film, a heat insulating film, a low dielectric constant film, and the like by being added to a thermosetting or thermoplastic resin to be molded into a plate shape or being added to an ultraviolet-curable resin to be formed into a film shape.

However, when the hollow particles are added to a thermosetting or thermoplastic resin and molded, or when the hollow particles are added to a curable resin composition and cured, there is a problem that the mechanical strength, particularly the abrasion resistance of the surface, of the molded or cured product is lowered. Techniques for solving this problem have been proposed in japanese patent laid-open nos. 2010-084017 (patent document 1), 2010-084018 (patent document 2), and 5411477 (patent document 3). These patent documents describe hollow particles obtained by surface-treating with an alkoxysilane and then further surface-treating with a silane coupling agent having a radical polymerizable group.

Disclosure of Invention

Problems to be solved by the invention

However, the hollow particles of the above patent documents have low dispersibility in organic solvents and curable resins, and therefore, molded articles and cured articles having sufficient abrasion resistance and transparency cannot be obtained.

Means for solving the problems

Thus according to the present invention there is provided a dispersion of hollow particles comprising: hollow particles having a shell formed of at least one or more layers, an acidic compound, and an organic solvent,

at least one of the foregoing layers contains nitrogen atoms and carbon atoms,

the content of the acidic compound is 0.01 to 70 parts by mass relative to 100 parts by mass of the total of the hollow particles and the acidic compound, and the content of the hollow particles is 0.01 to 30 parts by mass relative to 100 parts by mass of the hollow particle dispersion.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, a hollow particle dispersion suitable for producing a molded article having sufficient abrasion resistance can be provided.

According to the present invention, in the case of any of the following aspects, a hollow particle dispersion suitable for producing a molded article having more sufficient abrasion resistance can be provided.

(1) The acidic compound has an acid value of 10 to 300 mgKOH/g.

(2) The hollow particles have an average particle diameter of 30 to 120nm and a hollow ratio of 10 to 70%.

(3) The hollow particles have a relationship of 0.01. ltoreq.N/C.ltoreq.0.2 in the XPS measurement.

(4) For the hollow particles, the presence ratio of silicon atoms Si to the presence ratio of carbon atoms C in XPS measurement satisfies the relationship of 0.001. ltoreq. Si/C.ltoreq.0.1.

(5) The infrared absorption spectrum of the hollow particles measured by ATR-FTIR was calculated to be 810cm^-1Absorbance (A810) and 1720cm^-1The absorbance ratio alpha (absorbance ratio alpha: A810/A1720) of (A1720) shows an absorbance ratio alpha of 0.015 to 0.50.

(6) The acidic compound is selected from the group consisting of inorganic acids, carboxylic acid compounds, alkyl ester compounds of acids, sulfonic acid compounds, phosphate ester compounds, phosphonic acid compounds, and phosphinic acid compounds.

(7) The organic solvent is selected from alcohol solvents, ketone solvents, ester solvents, glycol ether solvents, and glycol ester solvents.

Detailed Description

(A) Hollow particle dispersion

The hollow particle dispersion contains at least: hollow particles, an acidic compound, and an organic solvent for dispersing the hollow particles. The hollow particles may be contained in an amount of 0.01 to 30 parts by mass per 100 parts by mass of the hollow particle dispersion.

The organic solvent is not particularly limited as long as it dissolves the hollow particles, and an aqueous or oily medium can be used. Examples thereof include: alcohol solvents such as ethanol and isopropanol, hydrocarbon solvents such as toluene, xylene and cyclohexane, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, ether solvents such as diisopropyl ether and 1, 4-dioxane, glycol solvents such as ethylene glycol and diethylene glycol, glycol ether solvents such as propylene glycol monomethyl ether and propylene glycol monobutyl ether, glycol ester solvents such as ethylene glycol monoethyl ether acetate and propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether solvents such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether, halogen solvents such as perchloroethylene and 1-bromopropane, dimethylformamide, N-methyl-2-pyrrolidone and dimethyl sulfoxide. Among them, alcohol solvents, ketone solvents, ester solvents, glycol ether solvents, and glycol ester solvents are preferable from the viewpoint of handling properties. In addition, water or one or more different organic solvents may be added to the organic solvent as necessary.

The hollow particle dispersion contains an acidic compound as a dispersant. By containing the acidic compound, the dispersibility of the hollow particles can be further improved. The acid group constituting the acidic compound interacts with the lone electron pair of the nitrogen atom contained in the hollow particles, so that dispersibility in the organic solvent can be improved. As a result, higher abrasion resistance and high transparency can be imparted to the molded article and cured article obtained using the hollow particle dispersion. Further, the surface smoothness of the molded article and the cured product can be improved. The acidic compound is selected from, for example, inorganic acids such as nitric acid, phosphoric acid, sulfuric acid, and carbonic acid, carboxylic acid compounds, alkyl ester compounds of inorganic acids, sulfonic acid compounds, phosphoric acid ester compounds, phosphonic acid compounds, and phosphinic acid compounds. Among these, as the acidic compound, alkyl ester compounds of sulfuric acid, sulfonic acid compounds, phosphate compounds, phosphonic acid compounds, and phosphinic acid compounds which can further improve the dispersibility of the hollow particles are preferable.

The acidic compound preferably has an acid value of 10 to 300 mgKOH/g. When the acid value is less than 10mgKOH/g, the improvement of the dispersibility of the hollow particles becomes insufficient, and the abrasion resistance of a molded article obtained using the hollow particle dispersion may become insufficient. When the amount of the catalyst is more than 300mgKOH/g, the dispersibility of the hollow particles in the organic solvent may be lowered. The acid value may be 10mgKOH/g, 15mgKOH/g, 20mgKOH/g, 50mgKOH/g, 100mgKOH/g, 150mgKOH/g, 200mgKOH/g, 250mgKOH/g, or 300 mgKOH/g. The acid value is preferably 15 to 300mgKOH/g, more preferably 20 to 250 mgKOH/g.

The content of the acidic compound is 0.01-70 parts by mass relative to 100 parts by mass of the total of the hollow particles and the acidic compound. When the content is less than 0.01 part by mass, good dispersibility may not be obtained. When the amount is more than 70 parts by mass, the abrasion resistance of a molded article obtained using the hollow particle dispersion may be poor. The content may be 0.01 part by mass, 0.1 part by mass, 0.5 part by mass, 1 part by mass, 2 parts by mass, 5 parts by mass, 10 parts by mass, 30 parts by mass, 50 parts by mass and 70 parts by mass. The content is preferably 1 to 50 parts by mass, more preferably 2 to 30 parts by mass.

In addition, the hollow particle dispersion may contain any binder.

The binder is not particularly limited, and a known binder resin can be used as the binder. Examples of the binder resin include thermosetting resins, thermoplastic resins, and the like, and more specifically, examples thereof include fluorine-based resins, polyamide resins, acrylic resins, polyurethane resins, acrylic urethane resins, butyral resins, and the like. These binder resins may be used alone or in combination of 2 or more. The binder resin may be a homopolymer of 1 reactive monomer or a copolymer of a plurality of monomers. In addition, reactive monomers may also be used as binders.

Examples of the reactive monomer include: methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, pentyl (meth) acrylate, (cyclo) hexyl (meth) acrylate, heptyl (meth) acrylate, (iso) octyl (meth) acrylate, nonyl (meth) acrylate, monofunctional reactive monomers such as esters of (meth) acrylic acid and alcohols having 1 to 25 carbon atoms, such as (iso) decyl (meth) acrylate, norbornyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, lauryl (meth) acrylate, tetradecyl (meth) acrylate, (iso) stearyl (meth) acrylate, phenoxyethylene glycol (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, and 2-ethylhexyl (meth) acrylate;

trimethylolpropane tri (meth) acrylate, tripropylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 1, 6-hexanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, tripentaerythritol octa (meth) acrylate, tetrapentaerythritol deca (meth) acrylate, isocyanuric acid tri (meth) acrylate, isocyanuric acid di (meth) acrylate, polyester tri (meth) acrylate, polyester di (meth) acrylate, ethylene glycol di (meth) acrylate, propylene glycol di (meth), And polyfunctional reactive monomers such as bisphenol di (meth) acrylate, diglycerol tetra (meth) acrylate, adamantyl di (meth) acrylate, isobornyl di (meth) acrylate, dicyclopentane di (meth) acrylate, tricyclodecane di (meth) acrylate, and ditrimethylolpropane tetra (meth) acrylate.

In addition, when these reactive monomers are used, a polymerization initiator that initiates a curing reaction by ionizing radiation may be contained in the hollow particle dispersion. Examples of the polymerization initiator include imidazole derivatives, bisimidazole derivatives, N-arylglycine derivatives, organic azide compounds, titanocenes, aluminate complexes, organic peroxides, N-alkoxypyridinium salts, thioxanthone derivatives, and the like.

As the binder, for example, an inorganic binder such as a hydrolysate of silanolate can be used. Examples of the silanolate include: tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, 2-hydroxypropyltrimethoxysilane, 2-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, 3-hydroxypropyltriethoxysilane, 3-hydroxypropyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, allyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxytrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, tetraethoxysilane, methyltrimethoxysilane, and mixtures thereof, 3-methacryloxypropyltriethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-isocyanatopropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltriethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3- (meth) acryloxypropyltriethoxysilane, 3-ureidopropyltrimethoxysilane, 3-ureidopropyltriethoxysilane, and mixtures thereof, Dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, and the like.

The hollow particle dispersion may further contain other additives such as a curing agent, a coloring agent, an antistatic agent, and a leveling agent.

The substrate to be coated with the hollow particle dispersion is not particularly limited, and a substrate suitable for the purpose may be used. Examples of the substrate to be coated include transparent substrates such as glass substrates and transparent resin substrates for optical applications.

(hollow particle)

The hollow particles have a shell formed from at least one more layer. The layer constituting the shell may be composed of one or more than two layers.

At least one of the layers constituting the shell contains nitrogen atoms and carbon atoms. At least one of the layers constituting the shell preferably contains a vinyl resin. The vinyl resin is a resin containing a portion composed of a vinyl monomer. A vinyl resin composed of a vinyl monomer having no aromatic ring is particularly preferable because it has high weather resistance and can suppress yellowing over time. The entire shell may be made of a vinyl resin. The vinyl resin is preferably a polymer obtained by crosslinking a polymer of at least 1 or more kinds of radically reactive monomers having an epoxy group or an oxetanyl group with a crosslinkable monomer such as a polyamine-based compound.

For the hollow particles, in the measurement under XPS (X-ray photoelectron spectroscopy), it is preferable that the presence ratio of nitrogen atoms N to the presence ratio of carbon atoms C have a relationship of 0.01. ltoreq.N/C.ltoreq.0.2. When the N/C ratio is less than 0.01, the crosslinking density is low, and a low-molecular binder component may easily penetrate into the hollow interior. In addition, the acid compound is less likely to interact with the polymer, and sufficient dispersibility may not be imparted to the polymer. When the crosslinking density exceeds 0.2, pinholes tend to be generated and the low-molecular binder component may easily penetrate into the hollow interior. N/C may be 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1 and 0.2. N/C is more preferably 0.01 to 0.15, still more preferably 0.02 to 0.1.

In addition, at least one of the layers may contain a phosphorus atom and/or a sulfur atom. When these atoms are contained in at least one layer or more, the dispersibility of the hollow particles in the curable resin can be improved, or the physical strength of the hollow particles can be improved, whereby sufficient abrasion resistance and transparency can be imparted to the molded article. The phosphorus atom and/or sulfur atom of at least one or more layers may be confirmed for its presence by fluorescent X-ray analysis, XPS, or the like. The phosphorus atom and/or sulfur atom may be contained in at least one or more layers by using a monomer in which the vinyl-based resin itself contains a phosphorus atom and/or sulfur atom. In particular, it is preferable that at least one or more layers contain a phosphorus atom and a sulfur atom by performing surface treatment with a surface treatment agent containing a phosphorus atom and a sulfur atom, which will be described below. The entire shell may be a layer containing phosphorus atoms and/or sulfur atoms, or only a part of the layer may contain phosphorus atoms and/or sulfur atoms. The content of phosphorus atoms or sulfur atoms is preferably 0.2 to 5.00 mass%. When the content is less than 0.2% by mass, sufficient abrasion resistance may not be imparted to the molded article including the hollow particles. When the amount is more than 5.00% by mass, the dispersibility of the hollow particles in the curable resin may be lowered, or the hardness of the molded article may be excessively increased, resulting in a decrease in the abrasion resistance. The content may be 0.2 mass%, 0.3 mass%, 0.5 mass%, 1.00 mass%, 2.00 mass%, 3.00 mass%, 4.00 mass%, and 5.00 mass%. The content is more preferably 0.2 to 4.00 mass%, and still more preferably 0.3 to 3.00 mass%. The phosphorus atom and the sulfur atom may contain only one or both of them in at least one or more layers. When both atoms are contained, the content thereof may be 0.2 to 10.0 mass%. The content may be 0.2 mass%, 0.5 mass%, 1.00 mass%, 3.00 mass%, 5.00 mass%, 7.00 mass%, or 10.00 mass%.

Further, as the hollow particles, the following particles are preferable: from the infrared absorption spectrum obtained by measuring the hollow particles by ATR-FTIR (Infrared emission Spectroscopy) to calculate 810cm^-1Absorbance (A810) and 1720cm^-1The particles having an absorbance ratio alpha of 0.015 to 0.50 when the ratio alpha of the absorbance (A1720) is (absorbance ratio alpha: A810/A1720). The absorbance a810 is the absorbance corresponding to the absorption spectrum of out-of-plane bending vibration originating from the vinyl CH. The absorbance a1720 is an absorbance corresponding to an absorption spectrum of C ═ O stretching vibration derived from a carbonyl group. The absorbance ratio α can be used as an index indicating the degree of introduction of the radical reactive group into the hollow particles. Specifically, if the absorbance ratio α is increased, the radical reactive group introduced into the particles tends to be increased. By introducing a radical reactive group into the particles, the dispersibility in the curable resin and the adhesion to the cured resin are improved, and a molded product having high abrasion resistance is easily obtained. When the absorbance ratio α is less than 0.015, dispersibility and adhesiveness of the hollow particles may be lowered, and a molded article having low abrasion resistance may be obtained. Basically, a larger absorbance ratio α provides a molded article with higher abrasion resistance, and therefore, it is preferable that the absorbance ratio α is larger, but when it is larger than 0.50, the radical reactive group introduced into the hollow particles with time reacts, and aggregation may occur in the dispersion. The absorbance ratio α may be 0.015, 0.020, 0.050, 0.10, 0.20, 0.30, 0.40, and 0.50. The absorbance ratio α is more preferably 0.015 to 0.400, and still more preferably 0.020 to 0.300.

At least one of the aforementioned layers constituting the shell preferably contains silicon atoms. Further, an organic-inorganic hybrid vinyl resin (Si-containing resin) containing a silicon component is preferable. In the present specification, "organic-inorganic" means that silicon is used as an inorganic component and a resin other than silicon is used as an organic component.

The Si-containing resin is preferably a Si-containing resin obtained by: a Si-containing resin obtained by polymerizing or copolymerizing at least one monomer having a radical-reactive functional group such as a vinyl group, (meth) acryloyl group, allyl group, maleoyl group, fumaroyl group, styryl group, cinnamoyl group, or the like to obtain a copolymer, and crosslinking the obtained copolymer with a crosslinkable monomer such as a polyamine-based compound.

The Si-containing resin is preferably a copolymer obtained as follows: a copolymer obtained by crosslinking a copolymer of at least 1 or more kinds of radically reactive monomers having an epoxy group or an oxetanyl group and at least 1 or more kinds of radically reactive monomers having a silyl group with a crosslinkable monomer such as a polyamine-based compound. The epoxy group, oxetanyl group and silyl group are also referred to as a non-radical-reactive functional group.

In addition, as for the hollow particles, in the measurement by XPS, it is preferable that the presence ratio of silicon atoms Si to the presence ratio of carbon atoms C having the relationship of 0.001. ltoreq. Si/C. ltoreq.0.1 be satisfied. When the Si/C ratio is less than 0.001, the crosslinking density becomes low, and the low-molecular binder component may easily intrude into the hollow particles. When the crosslinking density exceeds 0.1, pinholes tend to be generated due to excessively high crosslinking density, and the low-molecular binder component may easily penetrate into the hollow particles. Si/C may be 0.001, 0.002, 0.005, 0.01, 0.03, 0.05, 0.08 and 0.1. Si/C is more preferably 0.002 to 0.05, still more preferably 0.002 to 0.02.

In addition, at least one or more layers of the hollow particles contain at least 1 of silicon atoms, sulfur atoms, and phosphorus atoms, and carbon atoms, and preferably have a total presence ratio M of silicon atoms, sulfur atoms, and phosphorus atoms in XPS of the hollow particles, in which the presence ratio M of the total of silicon atoms, sulfur atoms, and phosphorus atoms and the presence ratio C of carbon atoms satisfy the relationship of 0.001. ltoreq. M/C. ltoreq.0.2. When the M/C ratio is less than 0.001, the strength of the particles becomes insufficient, and deformed particles may easily occur. When the amount exceeds 0.2, the particles may be deformed. The NM/C is more preferably 0.001 to 0.15, still more preferably 0.001 to 0.1.

The hollow particles preferably have an average particle diameter of 30 to 120 nm. The hollow particles having an average particle diameter of less than 30nm may aggregate with each other, and the handling properties may deteriorate. When hollow particles having a particle size of more than 120nm are kneaded with a coating agent or a resin, surface irregularities and scattering at particle interfaces become large, and whitening may occur. The average particle diameter can be 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 100nm, or 120 nm. The average particle diameter is more preferably 30 to 100nm, and still more preferably 30 to 80 nm.

The hollow particles preferably exhibit a hollow ratio of 10 to 70%. If the content is less than 10%, the hollow portion is small, and desired characteristics may not be obtained. If the content is more than 70%, the hollow portion may become excessively large, and the strength of the hollow particles may be lowered. The hollow rate can be 10%, 15%, 20%, 25%, 30%, 40%, 50%, 60% and 70%. The hollow ratio is more preferably 20 to 60%, and still more preferably 25 to 50%.

The V value, which is an index for evaluating monodispersity, of the hollow particles in the hollow particle dispersion is preferably 30% or less, more preferably 25% or less, and still more preferably 20% or less. When the CV value exceeds 30%, the wear resistance may be lowered due to the presence of coarse particles. CV values may take 30%, 25%, 20%, 15%, 10% and 5%.

The shell preferably has few pinholes. When the number of pinholes in the shell is large, when these particles are used in a member whose thermal conductivity is desired to be adjusted, the low-molecular binder component is likely to enter the hollow particles. Therefore, when the hollow particles are used for a low refractive index material, a sufficient low refractive index may not be obtained, or when the hollow particles are used as a thermal conductivity modifier, the thermal conductivity may not be adjusted.

(1) Radically reactive monomers having epoxy or oxetanyl groups

At least 1 or more kinds of radical-reactive monomers having an epoxy group or an oxetanyl group have an epoxy group or an oxetanyl group and a radical-reactive functional group.

The radical-reactive functional group is not particularly limited as long as it is an ethylenically unsaturated group (vinyl group or vinyl group-containing functional group) which is reacted in radical polymerization. Examples thereof include vinyl, (meth) acryloyl, allyl, maleoyl, fumaroyl, styryl, and cinnamoyl groups. Among them, vinyl group, (meth) acryloyl group and allyl group are preferable in terms of easy control of reactivity.

The epoxy group or oxetanyl group is a functional group which reacts with a compound having an amino group, a carboxyl group, a chlorosulfonic group, a mercapto group, a hydroxyl group, an isocyanate group, or the like to form a polymer.

The reactive monomer having a radical reactive functional group and an epoxy group or an oxetanyl group is not particularly limited. Examples thereof include p-glycidylstyrene, glycidyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate glycidyl ether, (3-ethyloxetan-3-yl) methyl (meth) acrylate, and 3, 4-epoxycyclohexylmethyl (meth) acrylate. These monomers may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(2) Radically reactive monomers having silyl groups

At least 1 or more of the radically reactive monomers having a silyl group have a silyl group and a radically reactive functional group.

The radical reactive functional group is not particularly limited as long as it is an ethylenically unsaturated group that reacts in radical polymerization. Examples thereof include a vinyl group, (meth) acryloyl group, allyl group, maleoyl group, fumaroyl group, styryl group, cinnamoyl group, and the like. Among these, vinyl groups, (meth) acryloyl groups, and allyl groups, in which reactivity can be easily controlled, are preferable.

The reactive monomer having a silyl group and a radical reactive functional group is not particularly limited. Examples thereof include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, p-vinylmethoxysilane, 3-methacryloxypropyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 8-methacryloxyoctyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane. These monomers may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(3) Copolymers of radically reactive monomers having epoxy or oxetanyl groups and radically reactive monomers having silyl groups

In the aforementioned copolymer, the ratio (mass ratio) of components derived from the radical-reactive monomer having an epoxy group or an oxetanyl group and the radical-reactive monomer having a silyl group is preferably 1: 100 to 0.001. When the ratio of the component derived from the radical reactive monomer having a silyl group is less than 0.001, the strength of the shell is lowered, the hollow particles are deformed, or the hollow particles may not be obtained. If the thickness exceeds 100, the shell becomes too brittle, pinholes tend to be formed, and it may be difficult to improve the heat insulation of the film. The ratio (mass ratio) of the components may be 1: 100. 1: 50. 1: 10. 1: 5. 1: 1. 1: 0.1, 1: 0.01 and 1: 0.001. more preferred ratios are 1: 10 to 0.001, and more preferably in a ratio of 1: 1 to 0.01.

(4) Monofunctional monomers

The polymer formed from a radically reactive monomer having an epoxy group or an oxetane group may comprise a component derived from a monofunctional monomer having only 1 reactive functional group. Examples of the monofunctional monomer include esters of styrene, (meth) acrylic acid and alcohols having 1 to 25 carbon atoms.

Examples of the ester of (meth) acrylic acid and an alcohol having 1 to 25 carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, (cyclo) hexyl (meth) acrylate, heptyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) nonyl (meth) acrylate, (iso) decyl (meth) acrylate, (norbornyl (meth) acrylate, (isobornyl (meth) acrylate, adamantyl (meth) acrylate, lauryl (meth) acrylate, tetradecyl (meth) acrylate, (iso) stearyl (meth) acrylate, phenoxyethyleneglycol (meth) acrylate, phenoxydiethyleneglycol (meth) acrylate, and mixtures thereof, 2-ethylhexyl (meth) acrylate, and the like.

The monofunctional monomer may be used in 1 kind alone, or 2 or more kinds may be used in combination.

The content of the component derived from the radical-reactive monomer having an epoxy group or an oxetanyl group and the radical-reactive monomer having a silyl group is preferably 10% by mass or more of the total of the components derived from the reactive monomers. If the content is less than 10% by mass, the particles may not be hollow particles. The content may be 10 mass%, 20 mass%, 30 mass%, 40 mass%, 50 mass%, 60 mass%, 70 mass%, 80 mass%, 90 mass% and 100 mass%. The content of the component derived from the radical-reactive monomer having an epoxy group or an oxetanyl group and the radical-reactive monomer having a silyl group is more preferably 30% by mass or more, and still more preferably 50% by mass or more.

(5) Crosslinkable monomer

The vinyl resin may contain a component derived from a crosslinkable monomer such as a polyamine compound.

Examples of the polyamine-based compound include: ethylenediamine and its adducts, diethylenetriamine, dipropylenetriamine, triethylenetetramine, tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, dibutylaminopropylamine, hexamethylenediamine and its modifications;

aliphatic amines such as N-aminoethylpiperazine, bis-aminopropylpiperazine, trimethylhexamethylenediamine, bis-hexamethylenetriamine, dicyandiamide, diacetone acrylamide, various modified aliphatic polyamines, and polyoxypropylene diamine, alicyclic amines such as 3,3 ' -dimethyl-4, 4 ' -diaminodicyclohexylmethane, 3-amino-1-cyclohexylaminopropane, 4 ' -diaminodicyclohexylmethane, isophoronediamine, 1, 3-bis (aminomethyl) cyclohexane, N-dimethylcyclohexylamine, and bis (aminomethyl) norbornane, and modified products thereof;

aromatic amines such as 4,4 ' -diaminodiphenylmethane (methylenedianiline), 4 ' -diaminodiphenyl ether, diaminodiphenyl sulfone, m-phenylenediamine, 2,4 ' -tolylenediamine, m-tolylenediamine, o-tolylenediamine, m-xylylenediamine, and modified products thereof, and modified products of other specific amines;

tertiary amines such as polyamidoamines such as amidoamines and aminopolyamide resins, tris-2-ethylhexane salts of dimethylaminomethylphenol, 2,4, 6-tris (dimethylaminomethyl) phenol and tris (dimethylaminomethyl) phenol;

and the like.

The crosslinkable monomer may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

(6) Surface treating agent

The hollow particles may have: a surface treated with a compound having at least one anionic group. The surface treated with the compound imparts heat resistance, dispersibility in an organic solvent, and properties that a low-molecular binder component is less likely to penetrate into the hollow interior to the hollow particles.

The compound having an anionic group is selected from hydrochloric acid, organic dianhydrides, and oxo acids (for example, inorganic acids such as nitric acid, phosphoric acid, sulfuric acid, and carbonic acid, carboxylic acid compounds, alkyl ester compounds of sulfuric acid, sulfonic acid compounds, phosphate ester compounds, phosphonic acid compounds, phosphinic acid compounds, and other organic acids). These compounds are preferably compounds containing a phosphorus atom and/or a sulfur atom as a constituent.

The carboxylic acid compound is not particularly limited as long as it is a compound containing a carboxyl group. Examples thereof include straight chain carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, valeric acid, caproic acid, enanthic acid, caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, and stearic acid; branched carboxylic acids such as pivalic acid, 2-dimethylbutyric acid, 3-dimethylbutyric acid, 2-dimethylpentanoic acid, 2-diethylbutyric acid, 3-diethylbutyric acid, 2-ethylhexanoic acid, 2-methylheptanoic acid, 4-methyloctanoic acid and neodecanoic acid; cyclic carboxylic acids such as naphthenic acid and cyclohexanedicarboxylic acid. Among them, in order to effectively improve the dispersibility in an organic solvent, a linear carboxylic acid having 4 to 20 carbon atoms, a branched carboxylic acid, and the like are preferable.

In addition, as the carboxylic acid compound, carboxylic acids having a radically reactive functional group such as a vinyl group, (meth) acryloyl group, allyl group, maleoyl group, fumaroyl group, styryl group, cinnamoyl group, or the like can also be used. Examples thereof include acrylic acid, methacrylic acid, 2-acryloyloxyethylsuccinic acid, 2-methacryloyloxyethylsuccinic acid, 2-acryloyloxyethylhexahydrophthalic acid, 2-methacryloyloxyethylhexahydrophthalic acid, 2-acryloyloxyethylphthalic acid, 2-methacryloyloxyethylphthalic acid, vinylbenzoic acid and the like.

Examples of the alkyl ester compound of sulfuric acid include lauryl sulfate and the like.

The sulfonic acid compound is not particularly limited as long as it is a compound containing a sulfo group. Examples thereof include p-toluenesulfonic acid, benzenesulfonic acid, dodecylbenzenesulfonic acid, methanesulfonic acid, ethylsulfonic acid, vinylsulfonic acid, allylsulfonic acid, methallylsulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid.

The phosphate ester compound is not particularly limited as long as it is an ester compound of phosphoric acid. Examples thereof include dodecyl phosphate and polyoxyethylene alkyl ether phosphoric acid represented by the following general formula (a).

In the above formula, R₁Is C4-19 alkyl or allyl (CH)₂＝CHCH₂-, (meth) acryloyl group, and styryl group. Examples of the alkyl group having 4 to 19 carbon atoms include butyl, pentyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, stearyl, and the like. These groups may be linear or branched. Further, 1 kind or a plurality of kinds of them may be used in combination.

R₂Is H or CH₃。

n is the number of moles of alkylene oxide added, and is a value in a range necessary to provide a number of moles of alkylene oxide added of 0 to 30 when the total is 1 mole.

The combination of a and b is a combination of 1 and 2 or a combination of 2 and 1.

Further, KAYAMER PM-21, manufactured by Nippon Kabushiki Kaisha, and the like can be used.

Further, as the oxo acid, a polymer having an acid group may also be used. Examples thereof include: disperbyk103, Disperbyk 110, Disperbyk 118, Disperbyk 111, Disperbyk 190, Disperbyk 194N, Disperbyk 2015 (BYK-Chemie), Solsperse 3000, Solsperse 21000, Solsperse26000, Solsperse 36000, Solsperse 36600, Solsperse 41000, Solsperse 41090, Solsperse 43000, Solsperse 44000, Solsperse 46000, Solsperse 47000, Solsperse53095, Solsperse 55000 (Lubrizol), EFKA4401, EFKA4550(Efuca Additiveves), Flowten G-600, Flowten G-700, PAR G-900, Flowen-PB 1500, PAR-2200, LOjDA 375, LOjGW 1210, PARP 2, PARP 1210, DISPER-P1210, DISPER-PEN 1210, LOjDA 325, LOjBO, LOjPA-D.S.S.A.K.K.K.K.

If necessary, the surface treatment may be performed with a surface treatment agent such as a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a zirconate coupling agent, or an isocyanate compound.

Examples of the silane coupling agent include: methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, 1, 6-bis (trimethoxysilyl) hexane, alkoxysilanes such as trifluoropropyltrimethoxysilane, silazanes such as hexamethyldisilazane, chlorosilanes such as trimethylsilyl chloride, vinyltrimethoxysilane, vinyltriethoxysilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, dimethyldimethoxysilane, dimethyltrimethoxysilane, dimethyltriethoxysilane, decyltrimethoxysilane, 1, 6-bis (trimethoxysilyl) hexane, and trifluoropropyltrimethoxysilane, silazan, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N- (1, 3-dimethyl-butylidene) propylamine, N-phenyl-3-aminopropyltrimethoxysilane, tris- (trimethoxysilylpropyl) isocyanurate, 3-ureidopropyltrialkoxysilane, 3-mercaptopropylmethyldimethoxysilane, N-methyl-N-propyltrimethoxysilane, N-ethyl-3-aminopropyltrimethoxysilane, N-methyl-N-propyltrimethoxysilane, N-propyl-, Silane coupling agents such as 3-mercaptopropyltrimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide and 3-isocyanatopropyltriethoxysilane.

In addition to the silane-based coupling agent, a silane-based coupling agent represented by the following general formula (I) may be mentioned.

In the general formula (I), R¹Each independently represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 4 carbon atoms, or a phenyl group.

R²Each independently represents a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, an alkoxyalkyl group having 2 to 4 carbon atoms, or a phenyl group.

R³Represents a C1-30 organic group with a valence of 2.

R⁴Represents a hydrogen atom or a methyl group.

m represents an integer of 0 to 2.

R¹And R²In the above formula, examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group and a hexyl group. These alkyl groups may contain structural isomers.

R¹And R²In (3), examples of the alkoxyalkyl group having 2 to 4 carbon atoms include a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, a methoxybutyl group, an ethoxyethyl group, and a butoxymethyl group. These alkoxyalkyl groups may contain structural isomers.

As R¹And R²As the substituent(s), there may be mentioned a halogen atom(s) (fluoro atom (s))A chlorine atom, a bromine atom, an iodine atom), a hydroxyl group, an amino group, a phenyl group, etc.

R³In the above formula, the organic group having a valence of 2 and having 1 to 30 carbon atoms includes alkanediyl groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, tridecamethylene, and tetradecamethylene. The alkanediyl group may have a branched structure substituted with an alkyl group.

Specific examples of the silane-based coupling agent represented by the general formula (I) include:

3- (meth) acryloyloxypropyltrimethoxysilane, 3- (meth) acryloyloxypropyltriethoxysilane, 3- (meth) acryloyloxypropylmethyldimethoxysilane, 3- (meth) acryloyloxypropylmethyldiethoxysilane, 4- (meth) acryloyloxybutyltrimethoxysilane, 4- (meth) acryloyloxybutylmethyldimethoxysilane, 4- (meth) acryloyloxybutylmethyldiethoxysilane, 5- (meth) acryloyloxypentyltrimethoxysilane, 5- (meth) acryloyloxypentyltriethoxysilane, 5- (meth) acryloyloxypentylmethyldimethoxysilane, 5- (meth) acryloyloxypentylmethyldiethoxysilane, a salt thereof, a hydrate thereof, and a method, 6- (meth) acryloyloxyhexyltrimethoxysilane, 6- (meth) acryloyloxyhexyltriethoxysilane, 6- (meth) acryloyloxyhexylmethyldimethoxysilane, 6- (meth) acryloyloxyhexylmethyldiethoxysilane, 7- (meth) acryloyloxyheptyltrimethoxysilane, 7- (meth) acryloyloxyheptyltriethoxysilane, 7- (meth) acryloyloxyheptylmethyldimethoxysilane, 7- (meth) acryloyloxyheptylmethyldiethoxysilane, 8- (meth) acryloyloxyoctyltrimethoxysilane, 8- (meth) acryloyloxyoctyltriethoxysilane, 8- (meth) acryloyloxyoctylmethyldimethoxysilane, 8- (meth) acryloyloxyoctylmethyldiethoxysilane, 6- (meth) acryloyloxyhexyltrimethoxysilane, 6- (meth) acryloyloxyhexyltriethoxysilane, 6- (meth) acryloyloxyhexylmethyldimethoxysilane, 6- (meth) acryloyloxyheptyloxymethyldimethoxysilane, 7- (meth) acryloyloxymethyldiet, 9- (meth) acryloyloxynonyltrimethoxysilane, 9- (meth) acryloyloxynonyltriethoxysilane, 9- (meth) acryloyloxynonylmethyldimethoxysilane, 9- (meth) acryloyloxynonylmethyldiethoxysilane, 10- (meth) acryloyloxydecyltrimethoxysilane, 10- (meth) acryloyloxydecyltriethoxysilane, 10- (meth) acryloyloxydecylmethyldimethoxysilane, 10- (meth) acryloyloxydecylmethyldiethoxysilane, 11- (meth) acryloyloxyundecyltrimethoxysilane, 11- (meth) acryloyloxyundecyltriethoxysilane, 11- (meth) acryloyloxyundecylmethyldimethoxysilane, a salt thereof, a base, a polymer, 11- (meth) acryloyloxyundecylmethyldiethoxysilane, 12- (meth) acryloyloxydodecyltrimethoxysilane, 12- (meth) acryloyloxydodecyltriethoxysilane, 12- (meth) acryloyloxydodecylmethyldimethoxysilane, 12- (meth) acryloyloxydodecylmethyldiethoxysilane, 13- (meth) acryloyloxytridecyltrimethoxysilane, 13- (meth) acryloyloxytridecyltriethoxysilane, 13- (meth) acryloyloxytridecylmethyldimethoxysilane, 13- (meth) acryloyloxytridecylmethyldiethoxysilane, 14- (meth) acryloyloxytetradecyltrimethoxysilane, 14- (meth) acryloyloxytetradecyltriethoxysilane, 12- (meth) acryloyloxydodecyltrimethoxysilane, 12- (meth) acryloyloxydodecyltriethoxysilane, 14- (meth) acryloyloxytetradecylmethyldimethoxysilane, 14- (meth) acryloyloxytetradecylmethyldiethoxysilane and the like.

The silane coupling agent used in the present invention is not limited to these. The silane coupling agent is available from a Silicone manufacturer such as Shin-Etsu Silicone Company, for example.

Among the silane-based coupling agents, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 8-methacryloxyoctyltriethoxysilane, and 3-acryloxypropyltrimethoxysilane are preferable.

Examples of the titanate-based coupling agent include pleact TTS manufactured by Ajinomoto Fine Techno co., ltd., pleact 46B, Plenact 55, pleact 41B, Plenact 38S, Plenact 138S, Plenact 238S, Plenact 338X, Plenact 44, pleact 9SA, and pleact ET, but the titanate-based coupling agent used in the present invention is not limited to these.

Examples of the aluminate coupling agent include pleact AL-M manufactured by Ajinomoto Fine Techno co., ltd., and the aluminate coupling agent used in the present invention is not limited to these.

Examples of the zirconate coupling agent include, but are not limited to, ORGATIX ZA-45, ORGATIX ZA-65, ORGATIX ZC-150, ORGATIX ZC-540, ORGATIX ZC-700, ORGATIX ZC-580, ORGATIX ZC-200, ORGATIX ZC-320, ORGATIX ZC-126 and ORGATIX ZC-300 manufactured by Matsumoto Fine Chemical Co., Ltd.

Examples of the isocyanate compound include ethyl isocyanate, propyl isocyanate, isopropyl isocyanate, butyl isocyanate, tert-butyl isocyanate, hexyl isocyanate, dodecyl isocyanate, octadecyl isocyanate, cyclohexyl isocyanate, benzyl isocyanate, phenyl isocyanate, 4-butylphenyl isocyanate, 2-isocyanatoethyl methacrylate, 2-isocyanatoethyl acrylate, and 1,1- (bisacryloxymethyl) isocyanate, but the isocyanate compound used in the present invention is not limited to these.

The surface treatment agent may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

(7) Other additives

The hollow particles may contain other additives such as pigment particles (pigments), dyes, stabilizers, ultraviolet absorbers, antifoaming agents, thickeners, heat stabilizers, leveling agents, lubricants, and antistatic agents as necessary within a range not to impair the effects of the present invention.

The pigment particles are not particularly limited as long as they are pigment particles used in the art. Examples thereof include iron oxide pigments such as mica-like iron oxide and iron black; lead oxide pigments such as red lead and yellow lead; titanium oxide pigments such as titanium white (rutile type titanium oxide), titanium yellow, and titanium black; cobalt oxide; zinc oxide pigments such as zinc yellow; molybdenum oxide pigments such as molybdenum red and molybdenum white. The pigment particles may be used in a single amount of 1 kind, or in combination of 2 or more kinds.

(8) Use of hollow particle dispersions

The hollow particle dispersion is useful as a raw material for additives for applications where improvement in abrasion resistance is desired, i.e., paints, papers, information recording papers, heat insulating films, and thermoelectric conversion materials. The hollow particle dispersion is also useful as an additive for a coating agent (coating composition) used for a light diffusion film (optical sheet), a light guide plate ink, an antireflection film, a light extraction film, or the like, an additive for a master batch for forming a molded body such as a light diffusion plate or a light guide plate, or a raw material for an additive for cosmetics.

(a) Master batch

The master batch comprises hollow particles and a base resin.

The base resin is not particularly limited as long as it is a common thermoplastic resin. Examples of the resin include (meth) acrylic resins, alkyl (meth) acrylate-styrene copolymer resins, polycarbonate resins, polyester resins, polyethylene resins, polypropylene resins, and polystyrene resins. In particular, when transparency is required, the resin may be a (meth) acrylic resin, an alkyl (meth) acrylate-styrene copolymer resin, a polycarbonate resin, or a polyester resin. These base resins may be used alone or in combination of 2 or more. The base resin may contain a small amount of additives such as an ultraviolet absorber, a heat stabilizer, a colorant, and a filler.

The base particles can be produced by melt-kneading the hollow particles and the base resin, and molding the mixture by extrusion molding, injection molding, or other molding methods. The blending ratio of the hollow particles in the base particle is not particularly limited, but is preferably about 0.1 to 60% by mass, more preferably about 0.3 to 30% by mass, and further preferably about 0.4 to 10% by mass. If the blending ratio is higher than 60% by mass, the production of the base particles may be difficult. If the content is less than 0.1% by mass, the effect of the present invention may be reduced.

The base particles are molded into a molded article by, for example, extrusion molding, injection molding or pressure molding. In addition, a base resin may be newly added at the time of molding. The amount of the base resin added may be such that the proportion of the hollow particles contained in the finally obtained molded article is about 0.1 to 60% by mass. In addition, additives such as an ultraviolet absorber, a heat stabilizer, a colorant, and a filler may be added in a small amount during molding.

(b) Cosmetic material

Specific cosmetic materials capable of containing the hollow particles include: solid cosmetic such as perfume powder and foundation, powdery cosmetic such as baby powder and toilet powder, and liquid cosmetic such as lotion, milky lotion, cream, and body lotion. The dispersion of hollow particles is compounded into these cosmetics after removing the medium as necessary. In the case of a liquid cosmetic, the dispersion of hollow particles may be directly compounded into the cosmetic without removing the medium.

The compounding ratio of the hollow particles to these cosmetics also differs depending on the kind of the cosmetics. For example, in the case of a solid cosmetic such as a powder or foundation, the amount is preferably 1 to 20% by mass, and particularly preferably 3 to 15% by mass. In addition, in the case of powdery cosmetics such as baby powder and toilet powder, the amount is preferably 1 to 20% by mass, and particularly preferably 3 to 15% by mass. Further, in the case of liquid cosmetics such as lotions, milky lotions, creams, liquid foundations, body lotions, and preshift emulsions, the amount is preferably 1 to 15% by mass, and particularly preferably 3 to 10% by mass.

In these cosmetics, inorganic compounds such as mica and talc, coloring pigments such as iron oxide, titanium oxide, ultramarine blue, navy blue and carbon black, synthetic dyes such as azo dyes, and the like may be added for the purpose of improving optical functions and improving touch. In the case of a liquid cosmetic, the liquid medium is not particularly limited, and water, alcohol, hydrocarbon, silicone oil, vegetable or animal fat and oil may be used. These cosmetics may be added with moisturizers, anti-inflammatory agents, whitening agents, ultraviolet screening agents, bactericides, perspiration-removing agents, cooling agents, perfumes, and the like, which are generally used in cosmetics, in addition to the other components described above, and may be added with various functions.

(c) Heat-insulating film

The heat insulating film contains at least the hollow particles. The film or sheet-like article containing the hollow particles has an air layer inside the hollow particles, and therefore can be used as a heat insulating film. Further, since the hollow particles have a small particle diameter, a heat insulating film having high transparency can be obtained, and since the binder does not easily intrude into the hollow particles, a heat insulating film having high heat insulating property can be easily obtained. The aforementioned heat insulating film can be obtained as follows: the coating agent can be obtained by applying the coating agent to a base material by a known method such as a dipping method, a spray coating method, a spin coating method, a spinner method, or a roll coating method, drying the coating agent, and further heating, ultraviolet irradiation, or baking the coating agent as necessary.

(d) Anti-reflection film

The antireflection film contains at least the hollow particles. The film or sheet-like article containing the hollow particles has a refractive index lowered by an air layer inside the hollow particles, and therefore can be used as an antireflection film. In addition, the hollow particles have high heat resistance, and therefore, an antireflection film having high heat resistance can be obtained. The antireflection film can be obtained as follows: the coating agent can be obtained by applying the coating agent to a base material by a known method such as a dipping method, a spray coating method, a spin coating method, a spinner method, or a roll coating method, drying the coating agent, and further heating, ultraviolet irradiation, or baking the coating agent as necessary.

(e) Substrate with antireflection film

The substrate with an antireflection film is obtained by forming the antireflection film on the surface of a substrate such as glass, polycarbonate, acrylic resin, plastic sheets such as PET and TAC, a substrate such as a plastic film, a plastic lens or a plastic panel, a cathode ray tube, a fluorescent display tube or a liquid crystal display panel. Depending on the application, the coating film may be formed alone or in combination with a protective film, a hard coat film, a planarizing film, a high refractive index film, an insulating film, a conductive resin film, a conductive metal particle film, a conductive metal oxide particle film, a pretreatment agent film used as needed, or the like on the substrate. When used in combination, the antireflection film is not necessarily formed on the outermost surface.

(f) Light extraction film

The light extraction film contains at least the hollow particles. In LED and organic EL lighting, since the difference in refractive index between an air layer and a light-emitting layer is large, emitted light is easily confined in the element. Therefore, a light extraction film is used for the purpose of improving the light emission efficiency. The film or sheet-like article containing the hollow particles has a refractive index lowered by an air layer inside the hollow particles, and therefore can be used as a light extraction film. In addition, the hollow particles have high heat resistance, and therefore, a light extraction film having high heat resistance can be obtained. The light extraction film can be obtained as follows: the coating agent can be obtained by applying the coating agent to a base material by a known method such as a dipping method, a spray coating method, a spin coating method, a spinner method, or a roll coating method, drying the coating agent, and further heating, ultraviolet irradiation, or baking the coating agent as necessary.

(g) Base material with light extraction film

The substrate with a light extraction film is formed by forming the light extraction film on the surface of a substrate such as glass, polycarbonate, acrylic resin, plastic sheets such as PET and TAC, plastic films, plastic lenses, plastic panels, cathode ray tubes, fluorescent display tubes, and liquid crystal display panels. Depending on the application, the coating film may be formed alone or in combination with a protective film, a hard coat film, a planarizing film, a high refractive index film, an insulating film, a conductive resin film, a conductive metal particle film, a conductive metal oxide particle film, a pretreatment agent film used as needed, or the like on the substrate. When used in combination, the light extraction film is not necessarily formed on the outermost surface.

(h) Low dielectric constant film

The low dielectric constant film contains at least the hollow particles. The thin film or sheet-like article containing the hollow particles has an air layer inside the hollow particles, and thus can be used as a low dielectric constant film. Further, since the hollow particles have a small particle diameter, a low dielectric constant film having high transparency can be obtained, and since the binder hardly penetrates into the hollow portion, a low dielectric constant film having a low relative dielectric constant can be easily obtained. Further, since the hollow particles are excellent in alkali resistance, a low dielectric constant film having high alkali resistance can be easily obtained. The aforementioned low dielectric constant film can be obtained as follows: the coating agent can be obtained by applying the coating agent to a base material by a known method such as a dipping method, a spray coating method, a spin coating method, a spinner method, or a roll coating method, drying the coating agent, and further heating, ultraviolet irradiation, or baking the coating agent as necessary.

(9) Method for producing hollow particle dispersion

The hollow particle dispersion is not particularly limited, and can be produced, for example, by performing the following steps: a step (polymerization step) of producing polymer particles containing a non-reactive solvent; a step of phase-separating the non-reactive solvent from the polymer particles (phase separation step); a step of removing the non-reactive solvent (solvent removal step); and a step of dispersing the dispersion in a medium (dispersing step) as necessary.

In the conventional method for producing hollow particles, a reactive monomer is polymerized 1 time to form a shell, and phase separation of an organic solvent (non-reactive solvent) and the shell is performed simultaneously with the polymerization. The present inventors considered that in this method, the step of simultaneously performing phase separation and polymerization causes the occurrence of pinholes and the reduction of monodispersity. In addition, it is considered that the pinholes of the shell prevent the decrease in thermal conductivity of the thin film and the decrease in reflectance of the thin film when the hollow particles are used as a thermal conductivity modifier. Therefore, the inventors considered that, if polymer particles are temporarily formed before phase separation of a non-reactive solvent and then phase separation occurs, the occurrence of pinholes can be suppressed and monodispersity can be improved.

Specifically, a reactive monomer having a radical-reactive functional group and a non-radical-reactive functional group is polymerized based on either of the two functional groups to produce polymer particles. The non-reactive solvent is previously mixed with the reactive monomer or absorbed after the polymer particles are manufactured, thereby being contained in the polymer particles. Then, the polymer is phase-separated from the non-reactive solvent by polymerization of the remaining other functional group based on the two functional groups, whereby microcapsule particles in which the non-reactive solvent is encapsulated can be obtained. Thereafter, the non-reactive solvent is removed, whereby hollow particles can be obtained.

The foregoing manufacturing method has the following advantages by separating polymerization and phase separation:

the gaps between the polymers of the shell existing in the conventional production method are not present, and the occurrence of pinholes in the obtained shell can be suppressed

Since the shape of the hollow particles does not depend on the oil droplets but depends on the shape and particle size distribution of the polymer particles before phase separation, the hollow particles having high monodispersity can be easily obtained.

The following describes a description of the production method.

(9-1) polymerization step

In the polymerization step, a reactive monomer having a radical-reactive functional group and a non-radical-reactive functional group is polymerized based on either of the two functional groups to produce polymer particles. The non-reactive solvent is previously mixed with the reactive monomer or absorbed after the polymer particles are manufactured, thereby being contained in the polymer particles.

(a) Method for producing polymer particles

As the method for producing the polymer particles, any method can be adopted from known methods such as bulk polymerization, solution polymerization, dispersion polymerization, suspension polymerization, emulsion polymerization, and the like. Among them, the suspension polymerization method or the emulsion polymerization method is preferable in that polymer particles can be produced relatively easily. Further, the emulsion polymerization method is more preferable in that polymer particles having high monodispersity can be easily obtained.

The polymer particles are obtained by polymerizing a radical reactive functional group or a non-radical reactive functional group.

The polymerization is preferably carried out by adding a compound which polymerizes a functional group to be polymerized.

(i) In the case of polymerizing the radical reactive functional group, a polymerization initiator may be used for the compound. The polymerization initiator is not particularly limited, and examples thereof include: persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate, cumene hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, dimethyl bis (t-butyl peroxide) hexane, dimethyl bis (t-butyl peroxide) hexyne-3, bis (t-butylperoxide isopropyl) benzene, bis (t-butyl peroxide) trimethylcyclohexane, butyl-bis (t-butyl peroxide) valerate, t-butyl 2-ethylhexane peroxide, dibenzoyl peroxide, p-menthane hydroperoxide and t-butylbenzoate peroxide, organic peroxides such as 2,2 '-azobis [2- (2-imidazolin-2-yl) propane ] dihydrochloride, 2' -azobis [2- (2-imidazolin-2-yl) propane ] disulfate dihydrate, 2,2 '-azobis (2-amidinopropane) dihydrochloride, 2' -azobis [ N- (2-carboxyethyl) -2-methylpropionamidine ] hydrate, 2 '-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl ] propane } dihydrochloride, 2' -azobis [2- (2-imidazolin-2-yl) propane ], 2 '-azobis (1-imino-1-pyrrolidine-2-ethylpropane) dihydrochloride, 2' -azobis { 2-methyl-N- [1, 1-bis (hydroxymethyl) -2-hydroxyethyl ] propionamide }, salts thereof, pharmaceutical compositions containing the same, and pharmaceutical compositions containing the same, 2,2 ' -azobis [ 2-methyl-N- (2-hydroxyethyl) propionamide ], 4,4 ' -azobis (4-cyanovaleric acid), 2 ' -azobisisobutyronitrile, 2 ' -azobis (2-methyl-butyronitrile), 2 ' -azobis (2-isopropylbutyronitrile), 2 ' -azobis (2, 3-dimethylbutyronitrile), 2 ' -azobis (2, 4-dimethylbutyronitrile), 2 ' -azobis (2-methylhexanitrile), 2 ' -azobis (2,3, 3-trimethylbutyronitrile), 2 ' -azobis (2,4, 4-trimethylvaleronitrile), 2 ' -azobis (2, 4-dimethylvaleronitrile), 2,2 '-azobis (2, 4-dimethyl-4-ethoxyvaleronitrile), 2' -azobis (2, 4-dimethyl-4-N-butoxyvaleronitrile), 2 '-azobis (4-methoxy-2, 4-dimethylvaleronitrile), 2' -azobis [ N- (2-propenyl) -2-methylpropionamide ], 2 '-azobis (N-butyl-2-methylpropionamide), 2' -azobis (N-cyclohexyl-2-methylpropionamide), 1 '-azobis (1-acetoxy-1-phenylethane), 1' -azobis (cyclohexane-1-carbonitrile), Azo compounds such as dimethyl-2, 2 '-azobis (2-methylpropionate), dimethyl-2, 2' -azobisisobutyrate, dimethyl-2, 2 '-azobis (2-methylpropionate), 2- (carbamoylazo) isobutyronitrile, and 4, 4' -azobis (4-cyanovaleric acid). The polymerization initiator may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Further, a redox initiator in which the above-mentioned polymerization initiator of the persulfate type and the organic peroxide type is combined with a reducing agent such as sodium formaldehyde sulfoxylate, sodium hydrogen sulfite, ammonium bisulfite, sodium thiosulfate, ammonium thiosulfate, hydrogen peroxide, sodium hydroxymethanesulfinate, L-ascorbic acid and salts thereof, cuprous salt, ferrous salt, or the like may be used as the polymerization initiator.

When the polymerization is emulsion polymerization, the polymerization initiator is preferably a water-soluble polymerization initiator capable of emulsion polymerization in an aqueous solvent. The water-soluble polymerization initiator is not particularly limited, and examples thereof include: persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, 2 '-azobis [2- (2-imidazolin-2-yl) propane ] dihydrochloride, 2' -azobis [2- (2-imidazolin-2-yl) propane ] disulfate dihydrate, 2 '-azobis (2-amidinopropane) dihydrochloride, 2' -azobis [ N- (2-carboxyethyl) -2-methylpropionamidine ] hydrate, 2 '-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl ] propane } dihydrochloride, 2' -azobis [2- (2-imidazolin-2-yl) propane ], azo compounds such as 2,2 '-azobis (1-imino-1-pyrrolidine-2-ethylpropane) dihydrochloride, 2' -azobis { 2-methyl-N- [1, 1-bis (hydroxymethyl) -2-hydroxyethyl ] propionamide }, 2 '-azobis [ 2-methyl-N- (2-hydroxyethyl) propionamide ], 4' -azobis (4-cyanopentanoic acid), and the like.

(ii) The polymer particles preferably have the free radical reactive functional groups polymerized first, thereby having unreacted non-free radical reactive functional groups in the polymer. If the non-radical reactive functional group is polymerized first, the non-reactive solvent may not be easily absorbed.

The polymer particles preferably have the reactive functional group of one of the radical reactive functional group and the non-radical reactive functional group unreacted in the polymer by polymerizing the reactive functional group of the other. However, there is no big problem that the total amount of the functional groups polymerized in the production of the polymer particles is not polymerized, and the partial polymerization is performed, or there is no big problem that the other reactive functional group is partially polymerized. For example, when a radical-reactive functional group of glycidyl methacrylate is polymerized to prepare polymer particles having an epoxy group, an unreacted radical-reactive functional group may remain, or a ring-opening reaction may be partially performed on the epoxy group (in other words, an amount of epoxy group capable of undergoing a phase separation may remain in the polymer particles).

(iii) Chain transfer agents may be used in the polymerization of the reactive monomers. The chain transfer agent is not particularly limited, and examples thereof include alkyl mercaptans such as n-hexyl mercaptan, n-octyl mercaptan, tert-octyl mercaptan, n-dodecyl mercaptan and tert-dodecyl mercaptan, phenol compounds such as α -methylstyrene dimer, 2, 6-di-tert-butyl-4-methylphenol and styrenated phenol, allyl compounds such as allyl alcohol, and halogenated hydrocarbon compounds such as methylene chloride, methylene bromide and carbon tetrachloride. The chain transfer agent may be used in a single species or in combination of 2 or more species.

The upper limit of the amount of the chain transfer agent to be used is 50 parts by mass with respect to 100 parts by mass of the reactive monomer.

(b) Absorption of non-reactive solvents

The absorption of the polymer particles by the non-reactive solvent may be performed at the time of or after the manufacture of the polymer particles. In addition, the absorption of the non-reactive solvent may be carried out in the presence or absence of a dispersion medium that is not compatible with the non-reactive solvent. When the reaction is carried out in the presence of a dispersion medium, the absorption of the non-reactive solvent can be efficiently carried out, and therefore, the reaction is preferable. When a medium is used in the production of the polymer particles, the medium may be used as it is as a dispersion medium, or the medium may be once separated from the medium and then dispersed in the dispersion medium.

The polymer particles can be absorbed with a non-reactive solvent by adding the non-reactive solvent incompatible with the dispersion medium to the dispersion medium containing the polymer particles and stirring the mixture for a predetermined period of time.

The absorption of the non-reactive solvent in the production of the polymer particles can be achieved by selecting a dispersion medium and a non-reactive solvent suitable for the production of the polymer particles. For example, when polymer particles are produced by emulsion polymerization in an aqueous solvent, the production of polymer particles and the absorption of polymer particles can be performed simultaneously by adding a non-reactive solvent incompatible with water to the aqueous solvent in advance and polymerizing a reactive monomer. If the production of the polymer particles and the absorption of the polymer particles are performed simultaneously, the time taken for the absorption of the non-reactive solvent can be reduced.

(i) Dispersion medium

The dispersion medium is not particularly limited as long as it is a liquid that does not completely dissolve the polymer particles. Examples thereof include: water; alcohols such as ethanol, methanol, and isopropanol; alkanes such as butane, pentane, hexane, cyclohexane, heptane, decane, hexadecane and the like; aromatic hydrocarbons such as toluene and xylene; ester solvents such as ethyl acetate and butyl acetate; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; a halogen-based solvent such as methyl chloride, methylene chloride, chloroform or carbon tetrachloride. These may be used alone in 1 kind, or in combination of 2 or more kinds.

(ii) Non-reactive solvent

The non-reactive solvent is not particularly limited as long as it is a liquid that is not compatible with the dispersion medium. Here, the term "not compatible with the dispersion medium" means that the solubility of the non-reactive solvent in the dispersion medium (at 25 ℃) is 10% by mass or less. For example, when water is used as the dispersion medium, examples of the non-reactive solvent that can be used include butane, pentane, hexane, cyclohexane, heptane, decane, hexadecane, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 1, 4-dioxane, monochloromethane, dichloromethane, chloroform, carbon tetrachloride, and the like. These may be used alone in 1 kind, or in combination of 2 or more kinds.

The amount of the non-reactive solvent to be added is not particularly limited, and is 20 to 5000 parts by mass per 100 parts by mass of the polymer particles. If the amount is less than 20 parts by mass, the hollow portion of the resulting hollow particles becomes small, and desired properties may not be obtained. If it exceeds 5000 parts by mass, the hollow portion becomes excessively large, and the strength of the resulting hollow particles may be lowered.

(9-2) phase separation Process

Subsequently, the residual reactive functional groups are polymerized, and the polymer is phase-separated from the non-reactive solvent. By phase separation, microcapsule particles having a non-reactive solvent encapsulated therein can be obtained. In the present invention, the hollow portion of the hollow particle includes not only the case where air is present in the hollow portion but also microcapsule particles in which a non-reactive solvent or other dispersion medium is present in the hollow portion.

The compound to be added for polymerizing the residual reactive functional group may be the same as the polymerization initiator for polymerizing the radical reactive functional group and the crosslinking agent for polymerizing the non-radical reactive functional group described in the polymerization step.

(9-3) solvent removal (substitution) step

If necessary, the non-reactive solvent contained in the microcapsule particles is removed or replaced, whereby hollow particles having air or another solvent in the hollow portion can be obtained. The method for removing the non-reactive solvent is not particularly limited, and examples thereof include a vacuum drying method. The conditions for the reduced pressure drying method include, for example, a pressure of 500Pa or less, 30 to 200 ℃ and 30 minutes to 50 hours. Alternatively, the non-reactive solvent may be replaced by a solvent replacement operation. For example, a suitable dispersion medium is added to microcapsule particles or these dispersions in which a non-reactive solvent is encapsulated, and stirring or the like is performed, whereby the non-reactive solvent in the interior of the particles is replaced with the dispersion medium. Thereafter, the excess non-reactive solvent and the dispersion medium are removed by a reduced pressure drying method, a centrifugal separation method, an ultrafiltration method, or the like, whereby the non-reactive solvent can be replaced. The solvent substitution may be carried out only once or a plurality of times.

(9-4) (Dispersion step)

The hollow particle dispersion may be, for example, a microcapsule particle dispersion containing a non-reactive solvent obtained after the phase separation step as it is, or a dispersion obtained by substitution with another solvent.

In the case of substitution with another solvent, the solvent present after the phase separation step is temporarily removed to remove the hollow particles, and the hollow particles thus removed can be dispersed in a desired medium.

(9-5) other steps

The surface of the hollow particles may be treated with the compound having an anionic group by adding the compound having an anionic group to the hollow particle dispersion after the phase separation step and stirring the mixture, or adding the compound having an anionic group to the hollow particles after the solvent removal step and mixing the mixture. Among these, it is preferable that after removing the excessive crosslinking agent after the phase separation step, the compound having an anionic group is added to the hollow particle dispersion and stirred. The treatment conditions include, for example, 30 to 200 ℃ for 30 minutes to 50 hours.

The hollow particles may be used in the form of a dry powder obtained by drying a dispersion of hollow particles, if necessary. The method for drying the hollow particles is not particularly limited, and examples thereof include a vacuum drying method. In the dried powder, a dispersion solvent, a non-reactive solvent, and the like may remain without being dried.