Hollow resin particles, their manufacturing method, and their uses

Abstract

The present invention provides hollow resin particles having a reduced number of coarse particles and excellent particle strength, uses of such hollow resin particles, and a method for producing such hollow resin particles. The hollow resin particles according to an embodiment of the present invention are hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion, and have a porosity of 5 to 90%. The number of particles having a particle diameter of 10 μm or more per 1,000,000 particles is 45 or less, as determined using a flow-type particle image analyzer under measurement condition A below. (Measurement condition A) Particle size measurement range (based on spherical equivalent volume): 0.5 μm to 200.0 μm, circularity measurement range: 0.97 to 1.00

Description

[Technical Field]

[0001] The present invention relates to hollow resin particles, a method for producing the same, and uses thereof. [Background technology]

[0002] Hollow resin particles are a material that can impart properties such as low dielectric constant and low refractive index to components in the semiconductor component market and display component market.

[0003] In recent years, the semiconductor component market has seen a wide range of research aimed at high-performance electronic circuits. For example, in the semiconductor component market, components such as packages, copper-clad laminates (rigid and flexible), interlayer insulating films, and underfill materials are becoming increasingly miniaturized in line with the miniaturization of chips. For example, in the case of underfill materials, a technology has been developed that uses an inorganic filler with an average diameter of approximately 2 μm and few coarse particles, thereby achieving a coating process that reduces viscosity and prevents clogging (Patent Document 1). For example, in the case of copper-clad laminates, a technology has been developed that uses 10 μm top-cut silica as an inorganic filler when creating prepregs (Patent Document 2). In the semiconductor component market, where miniaturization is progressing as shown in these examples, it is extremely important to use fillers with few coarse particles to improve yield and reliability.

[0004] Patent Document 3 describes hollow resin particles of submicron size with few coarse particles and a method for producing the same. However, this technology is characterized by treating silica particles whose surfaces are coated with a resin layer with an alkali metal-containing liquid to remove the silica, and there remains an issue in applying this technology to the semiconductor component market, as alkali metal residues and the like impair the insulating properties of the components.

[0005] Patent Document 4 describes hollow particles that aim to reduce dielectric constant. However, the hollow particles obtained by this technology have issues such as being brittle and prone to cracking, and the presence of a certain number of coarse particles exceeding 10 μm, which reduces yield and reliability when used to make components. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2024 / 075343 [Patent Document 2] International Publication No. 2020 / 203469 [Patent Document 3] Patent Publication No. 2021-094502 [Patent Document 4] International Publication No. 2024 / 048093 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made to solve the above-mentioned problems of the conventional art, and its main object is to provide hollow resin particles having a reduced number of coarse particles and excellent particle strength, a method for producing such hollow resin particles, and uses of such hollow resin particles. [Means for solving the problem]

[0008] [1] The hollow resin particles according to an embodiment of the present invention are A hollow resin particle having a shell portion and a hollow portion surrounded by the shell portion, The porosity is 5 to 90%. The number of particles with a particle diameter of 10 μm or more out of 1,000,000 particles determined using a flow particle image analyzer under the following measurement condition A is 45 or less. (Measurement condition A) Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00 [2] The hollow resin particles according to the above item [1], wherein the shell portion contains a polymer (P1) obtained by polymerizing the radical polymerizable monomer component (M) through a reaction of a composition containing the radical polymerizable monomer component (M), The radical polymerizable monomer component (M) may contain a crosslinkable monomer (a). [3] In the hollow resin particles described in [2] above, the content of the crosslinkable monomer (a) in the radical polymerizable monomer component (M) may be 20% by weight to 96% by weight. [4] In the hollow resin particles according to the above [2] or [3], the radical polymerizable monomer component (M) may contain a monofunctional monomer (b). [5] In the hollow resin particles described in [4] above, the content of the monofunctional monomer (b) in the radical polymerizable monomer component (M) may be 4% by weight to 80% by weight. [6] The hollow resin particles according to any one of [2] to [5] above, wherein the composition contains a polymer component (P2), The polymer component (P2) may have a number average molecular weight of 500 to 200,000. [7] In the hollow resin particles described in [6] above, the polymer component (P2) may be 0.1 to 20 parts by weight when the total amount of the radical polymerizable monomer component (M) is 100 parts by weight. [8] The hollow resin particles according to any one of the above [1] to [7] may have a volume average particle diameter of 0.1 μm to 5.0 μm. [9] The hollow resin particles according to any one of the above [1] to [8] may have a coefficient of variation of the volume average particle diameter of 25% or less.

[10] The hollow resin particles according to any one of the above [1] to [9] may be used as an additive for semiconductor members.

[11] The resin composition for a semiconductor member of the present invention contains the hollow resin particles according to any one of the above items [1] to

[10] .

[12] The hollow resin particles according to any one of the above [1] to [9] may be used as an additive for optical materials.

[13] A method for producing hollow resin particles according to an embodiment of the present invention includes: A method for producing hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion, comprising: The method includes a polymerization step of dispersing an oil phase containing a radical polymerizable monomer component (M), a polymerization initiator, and an organic solvent in an aqueous phase, and then polymerizing the resulting mixture; When the total amount of the radical polymerizable monomer components (M) is taken as 100 parts by weight, the amount of the polymerization initiator is 2.00 parts by weight or less.

[14] In the method for producing hollow resin particles according to the above

[13] , the oil phase contains a polymer component (P2), When the total amount of the radically polymerizable monomer components (M) is taken as 100 parts by weight, the amount of the polymer component (P2) may be 0.1 to 20 parts by weight.

[15] In the method for producing hollow resin particles according to the above

[13] or

[14] , the particles obtained in the polymerization step may have a particle size of 80 or less out of 1,000,000 particles, as determined by a flow particle image analyzer under the following measurement condition A: (Measurement condition A) Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00

[16] In the method for producing hollow resin particles according to any one of

[13] to

[15] above, the particles obtained in the polymerization step may have a ratio of particles having a particle diameter of 10 μm or more, as determined by the Coulter counter method (aperture diameter 50 μm), of 1.0 volume % or less relative to the total of particles having a particle diameter of 1 μm to 30 μm.

[17] The method for producing hollow resin particles according to any one of the above items

[13] to

[16] may include a classification step of classifying the particles obtained in the polymerization step.

[18] In the method for producing hollow resin particles according to

[17] above, the particles obtained in the classification step may have a particle size of 45 or less out of 1,000,000 particles, as determined by a flow particle image analyzer under the following measurement condition A (measurement condition A): Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00

[19] In the method for producing hollow resin particles according to any one of

[13] to

[18] above, the aqueous phase contains a dispersion stabilizer, The polymerization step may include dispersing the oil phase in the aqueous phase, and then emulsifying the resulting mixture at a pressure of 1 MPa to 200 MPa using a high-pressure emulsifier. [Effects of the Invention]

[0009] According to an embodiment of the present invention, hollow resin particles having a reduced number of coarse particles and excellent particle strength can be provided. Also, a method for producing such hollow resin particles can be provided. Furthermore, uses of such hollow resin particles can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

[0011] In this specification, the expression "(meth)acrylic" means "acrylic and / or methacrylic", the expression "(meth)acrylate" means "acrylate and / or methacrylate", and the expression "(meth)acrylonitrile" means "acrylonitrile and / or methacrylonitrile".

[0012] ≪≪1. Hollow resin particles≫≫ ≪1-1. Structure and characteristics of hollow resin particles≫ The hollow resin particles according to an embodiment of the present invention have a shell portion and a hollow portion surrounded by the shell portion. The hollow resin particles according to an embodiment of the present invention have a porosity of 5 to 90%. The hollow resin particles according to an embodiment of the present invention have a number of particles with a particle diameter of 10 μm or more per 1,000,000 particles of 45 or less, as determined using a flow-type particle image analyzer under the following measurement condition A: (Measurement condition A) Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00

[0013] Here, "hollow" means that the interior is filled with a substance other than resin, such as a gas or liquid, and preferably means that the interior is filled with gas, as this can better demonstrate the effects of the present invention.

[0014] The hollow portion may consist of a single hollow region, or may consist of multiple hollow regions or a porous structure. In the hollow resin particles according to an embodiment of the present invention, the hollow portion preferably has a single hollow structure consisting of a single hollow region. When the hollow portion is a single hollow portion, the resin component constituting the shell portion is relatively large, making the particles less likely to crack. Such hollow resin particles may have shell portions that are less likely to be crushed even when kneaded together with inorganic particles in a resin composition. Furthermore, when the hollow portion is a single hollow portion, penetration into the hollow portion of the substrate, etc. can be effectively prevented.

[0015] In this specification, the number of particles with a particle diameter of 10 μm or more out of 1,000,000 particles determined using a flow particle image analyzer under measurement condition A is referred to as the "number of coarse particles with a particle diameter of 10 μm or more." Examples of flow particle image analyzers include the FPIA-3000S (manufactured by Sysmex Corporation) and the Paasche Analyzer (manufactured by Hosokawa Micron Corporation).

[0016] In hollow resin particles according to an embodiment of the present invention, the number of coarse particles having a particle diameter of 10 μm or more determined as described above is 45 or less. That is, hollow resin particles according to an embodiment of the present invention may have a circularity of 0.97 or more and a proportion of coarse particles having a particle diameter of 10 μm or more of 0.0045% or less by number. Hollow resin particles according to an embodiment of the present invention, which have an extremely low number of coarse particles, are less likely to crack or chip and have excellent particle strength. Furthermore, since the hollow resin particles according to an embodiment of the present invention have a low number of coarse particles as described above, it is possible to thin resin layers made from resin compositions containing the particles. Furthermore, clogging can be prevented during the manufacturing process of resin compositions and various components. If the proportion of coarse particles is too high outside the above range, for example, when a resin layer is made from a resin composition containing the particles, it may be difficult to form a thin film or the thickness may vary. Furthermore, clogging may occur during the manufacturing process of the resin composition. Furthermore, unevenness may be formed in the resin layer, which may lead to a deterioration in adhesion to semiconductor components. From the above, the hollow resin particles according to the embodiment of the present invention are suitable for various members such as semiconductor members from the viewpoints of improving reliability and yield.

[0017] In the hollow resin particles according to an embodiment of the present invention, the number of coarse particles having a particle diameter of 10 μm or more, as determined using a flow-type particle image analyzer under the above measurement condition A, is preferably 40 or less, more preferably 30 or less, more preferably 20 or less, more preferably 10 or less, even more preferably 5 or less, particularly preferably 3 or less, and most preferably 1 or less, and may even be 0. According to the above configuration, the hollow resin particles can have superior particle strength.

[0018] In the hollow resin particles according to an embodiment of the present invention, the number of particles having a particle diameter of 8 μm or more and less than 10 μm per 1,000,000 particles, as determined using a flow particle image analyzer under the above measurement condition A (hereinafter referred to as the "number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm"), is preferably 55 or less, more preferably 50 or less, more preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, particularly preferably 15 or less, and most preferably 10 or less. This configuration allows the hollow resin particles to have superior particle strength. Such hollow resin particles are particularly suitable for various components such as semiconductor components.

[0019] The number of coarse particles having a particle size of 10 μm or more and the number of coarse particles having a particle size of 8 μm or more and less than 10 μm can be measured, for example, as follows.

[0020] First, 0.01 parts of surfactant (dodecylbenzenesulfonate) was added to 4.94 parts of ion-exchanged water to prepare a surfactant aqueous solution. 0.06 parts of hollow resin particles were added to the surfactant aqueous solution, and ultrasonic waves were applied for 10 minutes using a disperser (ultrasonic cleaner (VS-150, manufactured by Vervoclear)) to disperse the hollow resin particles in the surfactant aqueous solution, obtaining an aqueous dispersion of hollow resin particles for measurement.

[0021] When using an FPIA-3000S (manufactured by Sysmex Corporation) as a flow-type particle image analyzer, the obtained hollow resin particle aqueous dispersion is introduced into the flow-type particle image analyzer (FPIA-3000S, manufactured by Sysmex Corporation; equipped with a standard objective lens (10x)) and measured under the following measurement conditions: Particle sheath (PSE-900A, manufactured by Sysmex Corporation) is used as the sheath liquid. Measurement mode: HPF mode Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00 Before starting the measurement, the flow particle image analyzer is automatically focused using a suspension of standard polymer particles (for example, Thermo Fisher Scientific's 5200A (standard polystyrene particles diluted with ion-exchanged water)). The circularity is a value obtained by dividing the perimeter calculated from the diameter of a perfect circle having the same projected area as the image of the hollow resin particle by the perimeter of the image of the hollow resin particle. The circle-equivalent diameter (particle diameter) of 100,000 particles is measured within a particle circularity measurement range of 0.97 to 1.0, and the number of hollow resin particles having a particle diameter of 10.0 μm or more and the number of hollow resin particles having a particle diameter of 8 μm or more but less than 10 μm are counted. Here, the number of hollow resin particles having a particle diameter of 8 μm or more but less than 10 μm is the number of hollow resin particles having a particle diameter of 8.0 μm or more but less than 10 μm minus the number of hollow resin particles having a particle diameter of 10.0 μm. These operations were carried out 10 times (i.e., a total of 1,000,000 particle sizes were measured), and the total numbers of hollow resin particles with a volume average particle size of 10.0 μm or more and hollow resin particles with a particle size of 8 μm or more but less than 10 μm were counted. These sums were designated as the "number of coarse particles with a particle size of 10 μm or more" and the "number of coarse particles with a particle size of 8 μm or more but less than 10 μm," respectively.

[0022] When using a Paasche Analyzer (manufactured by Hosokawa Micron Corporation) as a flow-type particle image analyzer for measurement, the hollow resin particle aqueous dispersion prepared as described above is introduced into the flow-type particle image analyzer (manufactured by Hosokawa Micron Corporation, Paasche Analyzer; equipped with a standard objective lens (10x)) and measurement is performed under the following measurement conditions. PAS sheath fluid (manufactured by Hosokawa Micron Corporation) is used as the sheath fluid. Other operations are the same as those for the FPIA-3000S described above. Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00

[0023] In the hollow resin particles according to an embodiment of the present invention, the proportion of particles with a particle diameter of 10 μm or more, as determined by the Coulter counter method (aperture diameter 50 μm), may be 1.0% by volume or less relative to the total of particles with a particle diameter of 1 μm to 30 μm. In this specification, the proportion of particles with a particle diameter of 10 μm or more relative to the total of particles with a particle diameter of 1 μm to 30 μm, as determined by the Coulter counter method (aperture diameter 50 μm), may be referred to as the "proportion of particles with a particle diameter of 10 μm or more." The proportion of particles with a particle diameter of 10 μm or more in the hollow resin particles according to an embodiment of the present invention is preferably 0.70% by volume or less, more preferably 0.50% by volume or less, more preferably 0.30% by volume or less, even more preferably 0.20% by volume or less, particularly preferably 0.10% by volume or less, and most preferably 0.01% by volume or less. In the hollow resin particles according to an embodiment of the present invention, the proportion of particles with a particle diameter of 10 μm or more may be 0.00% by volume.

[0024] The hollow resin particles according to an embodiment of the present invention preferably have a porosity of 10% to 80%, more preferably 15% to 75%, even more preferably 15% to 70%, still more preferably 20% to 65%, particularly preferably 20% to 60%, and most preferably 23% to 55%. If the porosity of the hollow resin particles is within the above range, the hollow resin particles can have superior particle strength.

[0025] The volume average particle diameter (volume average primary particle diameter) of the hollow resin particles according to an embodiment of the present invention is not particularly limited and can be appropriately set depending on the purpose and application. The volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is, for example, 0.1 μm to 10.0 μm, preferably 0.1 μm to 5.0 μm, more preferably 0.2 μm to 5.0 μm, even more preferably 0.3 μm to 5.0 μm, particularly preferably 0.5 μm to 5.0 μm, and most preferably 1.0 μm to 5.0 μm. If the average particle diameter of the hollow resin particles is less than 0.1 μm, the shell thickness becomes relatively thin, which may result in hollow resin particles that do not have sufficient strength. If the average particle diameter of the hollow resin particles is greater than 10.0 μm, phase separation between the polymer and the solvent, which occurs when the monomer component is polymerized during suspension polymerization, may be difficult to occur, which may make it difficult to form the shell. The volume average particle size can be measured using, for example, a laser diffraction / scattering particle size distribution analyzer manufactured by Beckman Coulter.

[0026] The coefficient of variation of the volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is not particularly limited and can be appropriately set depending on the purpose and application. The coefficient of variation of the volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is, for example, 40.0% or less, preferably 30.0% or less, more preferably 25.0% or less, and even more preferably 23.0% or less. The coefficient of variation of the volume average particle diameter of the hollow resin particles according to an embodiment of the present invention may be, for example, 1.0% or more, 5.0% or more, or even 10.0% or more.

[0027] The hollow resin particles according to an embodiment of the present invention preferably have a metal residue content of 100 ppm or less, more preferably 50 ppm or less. If the metal residue content of the hollow resin particles exceeds 100 ppm, there is a risk that excellent low dielectric properties may not be achieved, uniform low dielectric properties may not be achieved, or the insulating properties of the components used may be impaired. Furthermore, if the metal residue content of the hollow resin particles exceeds 100 ppm, it may cause corrosion of the components. For example, the total K content and Na content of the hollow resin particles is preferably 50 ppm or less, more preferably 30 ppm or less, even more preferably 20 ppm or less, and most preferably 15 ppm or less.

[0028] ≪1-2. Shell part≫ The shell portion preferably contains a polymer (P1) obtained by polymerizing the radical polymerizable monomer component (M) through a reaction of a composition containing the radical polymerizable monomer component (M). That is, the polymer (P1) is obtained by a polymerization reaction of the radical polymerizable monomer component (M). The radical polymerizable monomer component (M) typically contains a vinyl-based monomer. Hereinafter, the radical polymerizable monomer component (M) will be referred to as the "monomer component (M)."

[0029] The polymer (P1) may be of one type only, or of two or more types.

[0030] The content of polymer (P1) in the shell portion is preferably 60% by weight to 100% by weight, more preferably 70% by weight to 100% by weight, even more preferably 80% by weight to 100% by weight, and particularly preferably 90% by weight to 100% by weight, in order to further exert the effects of the present invention.

[0031] The monomer component (M) preferably contains a crosslinkable monomer (a). The monomer component (M) preferably contains a monofunctional monomer (b). The monomer component (M) preferably contains the crosslinkable monomer (a) and the monofunctional monomer (b). Therefore, the polymer (P1) is preferably obtained by polymerizing the monomer component (M) containing the crosslinkable monomer (a) and the monofunctional monomer (b), and has a structural unit derived from the crosslinkable monomer (a) and a structural unit derived from the monofunctional monomer (b).

[0032] The polymer (P1) can be defined as being obtained by the reaction of the monomer components (M). This is because the polymer (P1) becomes a polymer through the reaction of the monomer components (M), and therefore it is impossible and almost impractical to directly identify the polymer (P1) by its structure. Therefore, the definition that "is obtained by the reaction of the monomer components (M)" appropriately identifies the polymer (P1) as a "product."

[0033] The crosslinkable monomer (a) may be any suitable crosslinkable monomer as long as it has crosslinkability (having two or more radically polymerizable double bonds in the skeleton) and does not impair the effects of the present invention, and is preferably a crosslinkable vinyl monomer. Examples of such crosslinkable monomer (a) include divinylbenzene, divinylnaphthalene, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, decaethylene glycol di(meth)acrylate, pentadecaethylene glycol di(meth)acrylate, pentacontahexaethylene glycol di(meth)acrylate, 1,3-butylene di(meth)acrylate, allyl (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetraacrylate, and neopentyl glycol di(meth)acrylate. The crosslinkable monomer (a) preferably includes an aromatic crosslinkable monomer having an aromatic functional group and two or more radically polymerizable double bonds in the skeleton, such as divinylbenzene, divinylnaphthalene, etc. The crosslinkable monomer (a) may be used alone or in combination of two or more.

[0034] The content of the crosslinkable monomer (a) in the monomer component (M) is preferably 20% by weight to 99% by weight, more preferably 20% by weight to 97% by weight, more preferably 20% by weight to 96% by weight, more preferably 25% by weight to 96% by weight, even more preferably 30% by weight to 95% by weight, particularly preferably 35% by weight to 90% by weight, and most preferably 35% by weight to 85% by weight, so that the effects of the present invention can be more effectively exhibited. When the shell portion contains the polymer (P1) having such a structure, the effects of the present invention can be more effectively exhibited.

[0035] As the monofunctional monomer (b), any appropriate monofunctional monomer can be adopted as long as it has a molecular structure having one radically polymerizable double bond in the skeleton, within a range that does not impair the effects of the present invention, and a monofunctional vinyl monomer is preferred. Examples of such monofunctional monomers (b) include aromatic monofunctional monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, t-butylstyrene, vinylnaphthalene, styrenesulfonic acid, styrenesulfonates (sodium styrenesulfonate, ammonium styrenesulfonate, etc.), vinylbenzoic acid (o-vinylbenzoic acid, m-vinylbenzoic acid, p-vinylbenzoic acid), vinylphenol (o-vinylphenol, m-vinylphenol, p-vinylphenol); methyl (meth)acrylate (methyl methacrylate, methyl acrylate), ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, s-butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, ethyl, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, (meth) ) (meth)acrylic acid alkyl esters having 1 to 20 carbon atoms in the alkyl group bonded to the ester, such as isostearyl acrylate, nonadecyl (meth)acrylate, and eicosyl (meth)acrylate; (meth)acrylic acid esters having an alicyclic structure in the ester moiety, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicyclopentanyl (meth)acrylate; hydroxyalkyl (meth)acrylate monomers such as hydroxyethyl (meth)acrylate; (meth)acrylic acid;Examples of the monomer include carboxyl group-containing hydrophilic monomers such as 2-methacryloyloxyethyl succinate, 2-methacryloyloxyethyl phthalate, 2-methacryloyloxyethyl hexahydrophthalate, 2-methacryloyloxyethyl maleate, 2-acryloyloxyethyl hexahydrophthalate, 2-acryloyloxyethyl succinate, and 2-acryloyloxyethyl phthalate; polyethylene glycol propylene glycol monomethacrylate; glycidyl group-containing monomers such as glycidyl (meth)acrylate, allyl glycidyl ether, and 4-hydroxybutyl (meth)acrylate glycidyl ether; epoxy group-containing monomers such as 1,2-epoxy-4-vinylcyclohexane and (3,4-epoxycyclohexyl)methyl (meth)acrylate; acrylamide derivative monomers such as 4-vinylphenyl glycidyl ether (meth)acrylamide; and (meth)acrylonitrile-based monomers. The monofunctional monomer (b) preferably contains an aromatic monofunctional monomer, and more preferably styrene, α-methylstyrene, t-butylstyrene, or vinylnaphthalene. The monofunctional monomer (b) may be used alone or in combination of two or more kinds.

[0036] The content of the monofunctional monomer (b) in the monomer component (M) is preferably 1 to 80% by weight, more preferably 3 to 80% by weight, more preferably 4 to 80% by weight, even more preferably 4 to 75% by weight, still more preferably 5 to 70% by weight, particularly preferably 10 to 65% by weight, and most preferably 15 to 65% by weight, so that the effects of the present invention can be more effectively exhibited. When the shell portion contains the polymer (P1) having such a structure, the effects of the present invention can be more effectively exhibited.

[0037] The total content of the crosslinkable monomer (a) and the monofunctional monomer (b) in the monomer component (M) is preferably 50% by weight to 100% by weight, more preferably 80% by weight to 100% by weight, even more preferably 90% by weight to 100% by weight, and particularly preferably 95% by weight to 100% by weight, in order to further exhibit the effects of the present invention.

[0038] The monomer component (M) may contain any other appropriate monomer different from the above-mentioned crosslinkable monomer (a) and monofunctional monomer (b) as long as the effect of the present invention is not impaired. The other monomer may be one kind or two or more kinds.

[0039] Examples of other monomers include halogenated vinyl monomers such as vinyl chloride, vinyl carboxylate monomers such as vinyl acetate, olefin monomers such as ethylene, unsaturated imide monomers, vinyl alcohol, silane coupling agents having a vinyl group, and phosphate ester monomers (product name "KAYAMER (registered trademark) PM-21"). The monomer component (M) may not contain other monomers.

[0040] The content of the monomer component (M) in the composition is preferably 85% by weight to 100% by weight, more preferably 90% by weight to 100% by weight, so that the effects of the present invention can be more effectively exhibited. If the content of the monomer component (M) in the composition is too low, outside the above range, the effects of the present invention may not be exhibited. Here, the monomer component (M) does not include the polymerization initiator and surfactant used in the polymerization reaction.

[0041] The composition preferably contains a polymer component (P2) in addition to the monomer component (M). The polymer component (P2) is a polymer different from the polymer (P1). The polymer component (P2) may or may not contain a polymerizable functional group. The polymer component (P2) may or may not react with the monomer component (M).

[0042] The number-average molecular weight of the polymer component (P2) is preferably 500 to 200,000. The inclusion of such a polymer component (P2) can promote phase separation of polymerized oil droplets during suspension polymerization, facilitating the formation of uniform particles. As a result, hollow resin particles with a small number of coarse particles and excellent particle strength can be obtained. Note that, if a polymer component (P2) with a number-average molecular weight of less than 500 is used, phase separation may be difficult to occur, which may make it difficult to form the shell portion. If a polymer component (P2) with a number-average molecular weight of more than 200,000 is used, the viscosity of the oil droplets may increase, which may result in an increase in the average particle size, irregular particle shape, or difficulty in forming the shell portion. Examples of such polymer component (P2) include polystyrene, polyethylene, polypropylene, aliphatic olefin polymers having 4 or more carbon atoms (which may have a linear structure or a branched side chain structure), polyphenylene ether, modified polyphenylene ether, polymethyl methacrylate, block copolymers of styrene and butadiene (e.g., styrene-butadiene-styrene block copolymer (SBS)), block copolymers of styrene and isoprene (e.g., styrene-isoprene-styrene block copolymer (SIS)), poly(meth)acrylic acid esters (aliphatic chains having 1 or more carbon atoms, which may be linear or branched), and paraffins. The polymer component (P2) may be one type or two or more types.

[0043] When the polymer component (P2) can react with the monomer component (M), the polymer (P1) can contain, for example, structural units derived from the crosslinkable monomer (a), structural units derived from the monofunctional monomer (b), and structural units derived from the polymer component (P2).When the polymer component (P2) does not react with the monomer component (M) or when the reactivity of the polymer component (P2) is low, the shell portion contains the polymer (P1) and the polymer component (P2).

[0044] The polymer component (P2) may contain a hydrocarbon-based resin. Any appropriate compound may be used as the hydrocarbon-based resin as long as it does not impair the effects of the present invention. Examples of hydrocarbon-based resins include aliphatic / aromatic hydrocarbon resins, aromatic hydrocarbon resins, alicyclic hydrocarbon resins, and aliphatic hydrocarbon resins. The hydrocarbon-based resin is preferably at least one selected from the group consisting of aliphatic / aromatic hydrocarbon resins, aromatic hydrocarbon resins, and aliphatic hydrocarbon resins, more preferably at least one selected from the group consisting of aliphatic / aromatic hydrocarbon resins and aromatic hydrocarbon resins, and even more preferably an aliphatic / aromatic hydrocarbon resin. As a result of the above, hollow resin particles with reduced coarse particles can be realized. These hydrocarbon-based resins may be used alone or in combination of two or more.

[0045] The aliphatic / aromatic hydrocarbon resin refers to a hydrocarbon resin in which an aliphatic hydrocarbon and an aromatic hydrocarbon are copolymerized. The aliphatic / aromatic hydrocarbon resin is a resin polymerized using, for example, styrene, vinyltoluene, indene, piperylene, or the like as a main raw material.

[0046] The aromatic hydrocarbon resin is a resin obtained by polymerizing, for example, styrene, vinyltoluene, indene, or the like as a main raw material.

[0047] Alicyclic hydrocarbon resins are resins obtained by hydrogenating, for example, aliphatic / aromatic hydrocarbon resins or aromatic hydrocarbon resins.

[0048] The aliphatic hydrocarbon resin is a hydrocarbon resin obtained by polymerizing one or more aliphatic hydrocarbons having a polymerizable unsaturated bond.

[0049] The content of the polymer component (P2) in the composition is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 20% by weight, even more preferably 0.5 to 18% by weight, particularly preferably 1 to 15% by weight, and most preferably 2 to 10% by weight, relative to 100 parts by weight of the total amount of the monomer components (M), in order to further exhibit the effects of the present invention.

[0050] ≪1-3. Uses of hollow resin particles≫ The hollow resin particles according to an embodiment of the present invention can be used in a variety of applications. Because they can further utilize the effects of the present invention, the hollow resin particles according to an embodiment of the present invention are suitable for use as additives for semiconductor components, additives for optical materials such as light diffusers and antiglare / low-reflection materials, paint additives, and ink additives, and are typically suitable for use in resin compositions for semiconductor components. As an example of the application of the hollow resin particles according to an embodiment of the present invention, a resin composition for semiconductor components will be described below.

[0051] The resin composition for a semiconductor member according to an embodiment of the present invention contains hollow resin particles according to an embodiment of the present invention.

[0052] The term "semiconductor member" refers to a member that constitutes a semiconductor, such as a semiconductor package or a semiconductor module. In this specification, the term "resin composition for a semiconductor member" refers to a resin composition used for a semiconductor member.

[0053] A semiconductor package is constructed using an IC chip as an essential component and at least one member selected from mold resin, underfill material, mold underfill material, die bond material, prepreg for semiconductor package substrate, metal-clad laminate for semiconductor package substrate, and build-up material for printed circuit board for semiconductor package.

[0054] A semiconductor module is constructed using a semiconductor package as an essential component and at least one member selected from prepregs for printed circuit boards, metal-clad laminates for printed circuit boards, build-up materials for printed circuit boards, solder resist materials, coverlay films, electromagnetic wave shielding films, and adhesive sheets for printed circuit boards.

[0055] 2. Method for producing hollow resin particles The hollow resin particles according to the embodiment of the present invention can be produced by any appropriate method as long as the effects of the present invention are not impaired.

[0056] The method for producing the hollow resin particles of the present invention (polymerization method) is not particularly limited as long as it is a known polymerization method, such as emulsion polymerization, suspension polymerization, seed (emulsion) polymerization, dispersion polymerization, miniemulsion polymerization, and microemulsion polymerization.

[0057] In the method for producing hollow resin particles (polymerization method) of the present invention, a polymerization initiator, a surfactant (emulsifier), a dispersant, etc. may be used as needed.

[0058] Emulsion polymerization is a polymerization method in which an aqueous medium, a monomer that is poorly soluble in the medium, and a surfactant (emulsifier) ​​are mixed, and then a polymerization initiator that is soluble in the aqueous medium is added to carry out polymerization. Emulsion polymerization is characterized by the small variation in particle size of the resulting resin particles.

[0059] Suspension polymerization is a polymerization method in which a monomer and an aqueous medium are mechanically stirred to suspend the monomer in the aqueous medium and polymerize it. The particles produced by suspension polymerization are characterized by larger particle diameters and a broader particle size distribution than those produced by emulsion polymerization. Furthermore, by using a microemulsifier such as a homogenizer, ultrasonicator, Nanomizer (registered trademark), Microfluidizer (registered trademark), Nanovaita (registered trademark), or coarse particle processor NVR (registered trademark), it is also possible to obtain particles with a relatively sharp particle size distribution.

[0060] Seed polymerization is a method in which polymer fine particles obtained by polymerizing a monomer are used as seed particles, the seed particles are allowed to absorb the monomer in a medium, the seed particles are swelled with the monomer, and then the monomer is polymerized within the seed particles. Seed polymerization allows the seed particles to grow, thereby producing resin particles with a particle size larger than that of the original seed particles. Seed emulsion polymerization is a method in which seed particles are grown while polymerizing using a water-soluble polymerization initiator.

[0061] Dispersion polymerization is a method in which a monomer is dispersed in a polymerization solvent that may contain a dispersion stabilizer, a polymerization initiator is added, and the monomer is polymerized. To prevent particles from coalescing during polymerization, the polymerization is preferably carried out under stirring by ultrasonic irradiation and / or stirring with a mechanical stirring device such as a magnetic stirrer. Dispersion polymerization is characterized by its ease of particle size control and the ease of obtaining resin particles.

[0062] In the production method according to the embodiment of the present invention, suspension polymerization, seed polymerization, or emulsion polymerization is preferred, and suspension polymerization using a microemulsifier is more preferred, since hollow resin particles having a uniform particle size and a small number of coarse particles can be obtained.

[0063] The method for producing hollow resin particles according to an embodiment of the present invention typically includes a polymerization step in which an oil phase containing a radically polymerizable monomer component (M), a polymerization initiator, and an organic solvent is dispersed in an aqueous phase containing an aqueous medium, followed by suspension polymerization. The monomer component (M) preferably contains a crosslinkable monomer (a) and a monofunctional monomer (b). The oil phase preferably contains a polymer component (P2) in addition to the monomer component (M), the polymerization initiator, and the organic solvent.

[0064] According to the above-described manufacturing method, the hollow resin particles according to the embodiment of the present invention can be easily manufactured.

[0065] The explanations in the section "Shell Portion" above can be applied to the monomer component (M) and the polymer component (P2). When the total amount of the monomer component (M) is taken as 100 parts by weight, the content of the polymer component (P2) is preferably 0.1 to 30 parts by weight, more preferably 0.1 to 20% by weight, even more preferably 0.5 to 18% by weight, particularly preferably 1 to 15% by weight, and most preferably 2 to 10% by weight.

[0066] The organic solvent may be one type only, or two or more types. Any appropriate organic solvent may be used as the organic solvent as long as it does not impair the effects of the present invention. As such an organic solvent, an organic solvent having a boiling point of less than 100°C is preferably used. By using an organic solvent having a boiling point of less than 100°C as the organic solvent, it becomes easy to remove the solvent from the hollow portion of the obtained hollow resin particles, and it becomes possible to reduce the production cost.

[0067] Examples of organic solvents having a boiling point of less than 100° C. include heptane, hexane, cyclohexane, methyl acetate, ethyl acetate, methyl ethyl ketone, chloroform, and carbon tetrachloride.

[0068] The amount of the organic solvent used may be any appropriate amount as long as it does not impair the effects of the present invention, for example, 10 to 250 parts by weight per 100 parts by weight of the monomer component (M).

[0069] The oil phase preferably contains a polymerization initiator. The polymerization initiator may be one type or two or more types. Any appropriate polymerization initiator may be used as the polymerization initiator as long as it does not impair the effects of the present invention.

[0070] The polymerization initiator is preferably a radical polymerization initiator, particularly a thermal polymerization initiator, such as an organic peroxide, an oil-soluble nitrile-azo compound, a water-soluble azo compound, a persulfate (e.g., ammonium persulfate, potassium persulfate, sodium persulfate, etc.), or hydrogen peroxide.

[0071] Examples of the polymerization initiator include 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]n hydrate (trade name "VA-057"), 4,4'-azobis(4-cyanovaleric acid) (trade name "V-501"), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] (trade name "VA-061" and its dihydrochloride salt). water-soluble azo compounds such as 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide] (trade name "VA-044"), 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)-2-hydroxyethyl]propionamide} (trade name "VA-086"), 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-080"), 2,2'-azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-082"), and 2,2'-azobis{2-methyl-N-[2-(1-hydroxybutyl)]propionamide} (trade name "VA-085") (all manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.); cumene hydroperoxide, di-tert-butylperoxide, etc. organic peroxides such as hexamethylpropional, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, dimethylbis(tert-butylperoxy)hexane, dimethylbis(tert-butylperoxy)hexyne-3, bis(tert-butylperoxyisopropyl)benzene, bis(tert-butylperoxy)trimethylcyclohexane, butyl-bis(tert-butylperoxy)valerate, tert-butyl 2-ethylhexaneperoxyate, dibenzoyl peroxide, paramenthane hydroperoxide, tert-butyl-2-ethylperoxyhexanoate, tert-butyl-2-ethylperoxyacetate, and tert-butyl peroxybenzoate;2,2'-Azobisisobutyronitrile, 2,2'-Azobis(2-methylbutyronitrile), 2,2'-Azobis(2-isopropylbutyronitrile), 2,2'-Azobis(2,3-dimethylbutyronitrile), 2,2'-Azobis(2,4-dimethylbutyronitrile), 2,2'-Azobis(2-methylcapronitrile), 2,2'-Azobis(2,3,3-trimethylbutyronitrile), 2,2'-Azobis(2,4,4-trimethylvaleronitrile), 2,2'-Azobis Oil-soluble nitrile-azo compounds such as 2,4-dimethylvaleronitrile, 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(4-ethoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(4-n-butoxy-2,4-dimethylvaleronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2-(carbamoylazo)isobutyronitrile, and 4,4'-azobis(4-cyanopentanoic acid);

[0072] Alternatively, a redox initiator may be used as the polymerization initiator, which is a combination of the above-mentioned persulfate and organic peroxide polymerization initiator with a reducing agent such as sodium sulfoxylate formaldehyde, sodium hydrogen sulfite, ammonium hydrogen sulfite, sodium thiosulfate, ammonium thiosulfate, hydrogen peroxide, sodium hydroxymethanesulfinate, L-ascorbic acid and its salts, cuprous salts, or ferrous salts.

[0073] Among these, the polymerization initiator is 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine]n hydrate (trade name "VA-057"), 4,4'-azobis(4-cyanovaleric acid) (trade name "V-501"), 2,2'-azobis[2-(2-imidazolin-2-yl)propane] (trade name "VA-061"), 2,2'-azobis[2-methyl-N-(2-hydroxypropyl)propane] (trade name "VA-062"), 4,4'-azobis(4-cyanovaleric acid) (trade name "V-501 ... 2,2'-Azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-086"), 2,2'-Azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-080"), 2,2'-Azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-082"), 2,2'-Azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-084"), 2,2'-Azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-085"), 2,2'-Azobis{2-methyl-N-[1,1-bis(hydroxymethyl)ethyl]propionamide} (trade name "VA-086 ... and 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 4,4'-azobis(4-cyanopentanoic acid), cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, tert-butyl-2-ethylperoxyhexanoate, and lauroyl peroxide.

[0074] The amount of the polymerization initiator used may be any appropriate amount as long as it does not impair the effects of the present invention. Such an amount is, for example, preferably 0.05 to 5.0 parts by weight, more preferably 0.08 to 3.0 parts by weight, even more preferably 0.1 to 2.0 parts by weight, particularly preferably 0.1 to 2.0 parts by weight, and most preferably 0.1 to 1.9 parts by weight, relative to 100 parts by weight of the monomer component (M).

[0075] In addition to the above-mentioned components, the oil phase may contain any other appropriate components as long as the effects of the present invention are not impaired. Such other components may be one type only, or two or more types.

[0076] Examples of aqueous media include water and mixed media of water and lower alcohols (alcohols having 5 or less carbon atoms, such as methanol, ethanol, and isopropyl alcohol). As water, at least one selected from the group consisting of ion-exchanged water and distilled water is preferred.

[0077] The amount of the aqueous medium used may be any appropriate amount as long as it does not impair the effects of the present invention. This amount is preferably 100 to 2,000 parts by weight, more preferably 200 to 1,000 parts by weight, relative to 100 parts by weight of the oil phase. By adjusting the amount of the aqueous medium used within the above range, the dispersion stability of the monomer during polymerization can be improved, and the generation of agglomerates of resin particles during polymerization can be suppressed.

[0078] The aqueous phase preferably contains a dispersion stabilizer. Any appropriate dispersion stabilizer may be used as the dispersion stabilizer as long as it does not impair the effects of the present invention. The dispersion stabilizer may be one type or two or more types.

[0079] Examples of dispersion stabilizers include water-soluble polymer compounds such as polyvinyl alcohol, polycarboxylic acid, celluloses (e.g., hydroxyethyl cellulose, carboxymethyl cellulose), and polyvinylpyrrolidone. Other examples of dispersion stabilizers include phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; pyrophosphates such as calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, and zinc pyrophosphate; and poorly water-soluble inorganic compounds such as calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, and colloidal silica. Among these, magnesium pyrophosphate is preferred because it is relatively easy to remove from the hollow resin particles and is less likely to remain on the surface of the hollow resin particles.

[0080] The amount of the dispersion stabilizer used may be any appropriate amount as long as it does not impair the effects of the present invention. The amount of the dispersion stabilizer used is preferably 0.5 to 10 parts by weight per 100 parts by weight of the aqueous medium.

[0081] The aqueous phase preferably contains a surfactant. Any appropriate surfactant may be used as the surfactant as long as it does not impair the effects of the present invention. The surfactant may be one type or two or more types. Examples of such surfactants include anionic surfactants, cationic surfactants, nonionic surfactants, and zwitterionic surfactants.

[0082] Examples of anionic surfactants include sodium oleate; fatty acid soaps such as castor oil potassium soap; polysulfonates; polycarboxylates; alkyl sulfate salts such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzenesulfonates such as sodium dodecylbenzenesulfonate; alkylarylsulfonates; alkylnaphthalenesulfonates; alkanesulfonates; dialkylsulfonates; dialkylsulfosuccinates; alkylphosphates; alkylphosphate ester salts; naphthalenesulfonate formalin condensates or salts thereof, such as the sodium salt of β-naphthalenesulfonate formalin condensate; polyoxyethylene alkylphenyl ether sulfate salts such as polyoxyethylene nonylphenyl ether sulfate salts; polyoxyethylene styrenated phenyl ether phosphate; polyoxyethylene alkyl ether phosphate; polyoxyethylene alkyl ether sulfates such as sodium polyoxyethylene lauryl ether sulfate and ammonium polyoxyethylene lauryl ether sulfate; polyoxyethylene alkyl sulfate salts; polyoxyethylene alkylphosphate sulfonates; glycerol borate fatty acid esters; and polyoxyethylene glycerol fatty acid esters. The anionic surfactant may be one type or two or more types. The counter cation of the anionic group is preferably an ammonium salt. By using such a surfactant, the amount of metal residue can be reduced.

[0083] Examples of cationic surfactants include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride. Only one type of cationic surfactant may be used, or two or more types may be used.

[0084] Examples of nonionic surfactants include (meth)acrylate sulfate ester surfactants (commercially available products include RMA-564, RMA-568, and RMA-1114 manufactured by Nippon Nyukazai Co., Ltd.); polyoxyalkylene branched decyl ethers; polyoxyalkylene alkyl ethers such as polyoxyethylene tridecyl ether, polyoxyethylene isodecyl ether, polyoxyethylene lauryl ether, and polyoxyethylene oleyl cetyl ether; polyoxyalkylene aryl ethers such as polyoxyethylene naphthyl ether and polyoxyethylene phenyl ether; polyoxyalkylene alkylaryl ethers; polyether polyols; polyoxyethylene styrenated phenyl ether; polyoxyethylene polyoxypropylene glycol; polyoxyethylene glyceryl isostearate; polyoxyethylene fatty acid esters; sorbitan fatty acid esters; polyoxysorbitan fatty acid esters; polyoxyethylene alkylamines; glycerin fatty acid esters; and oxyethylene-oxypropylene block polymers. The nonionic surfactants may be used alone or in combination of two or more types.

[0085] Examples of the zwitterionic surfactant include lauryl dimethylamine oxide, alkyldiaminoethylglycine hydrochloride, sodium laurylaminopropionate, alkylbetaine, etc. Only one type of zwitterionic surfactant may be used, or two or more types may be used.

[0086] A reactive surfactant having a vinyl group may be used as the surfactant. The reactive surfactant having a vinyl group may be one type or two or more types. When a reactive surfactant having a vinyl group is used, the reactive surfactant having a vinyl group can be incorporated into the polymer (P1), allowing the surfactant to be effectively localized on the particle surface during suspension polymerization, thereby improving the surfactant effect. This provides an excellent surfactant effect, inhibits particle aggregation and coalescence during production, reduces the by-production of non-standard particles, and reduces coarse particles.

[0087] Examples of reactive surfactants having a vinyl group include anionic surfactants having a vinyl group and nonionic surfactants having a vinyl group.

[0088] Examples of anionic surfactants having a vinyl group include polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium, polyoxyethylene styrenated propenyl phenyl ether sulfate ester ammonium, polyoxyalkylene alkenyl ether sulfate, α-sulfo-ω-(1-alkoxymethyl-2-(2-propenyloxy)ethoxy)-poly(oxy-1,2-ethanediyl)ammonium, polyoxypropylene allyl ether phosphate ester, and bis(polyoxyethylene phenyl ether) methacrylate sulfate ester. Furthermore, the counter cation of the anionic group is preferably an ammonium salt. The use of such surfactants can further reduce the average particle size of hollow resin particles and reduce the amount of coarse particles. Furthermore, the amount of metal residue can be reduced.

[0089] Commercially available polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium products include, for example, "Aqualon KH-10" (trade name) and "Aqualon KH-1025" (25 wt % aqueous solution of "Aqualon KH-10") manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

[0090] Commercially available polyoxyethylene styrenated propenyl phenyl ether sulfate ester ammonium products include, for example, trade names "Aqualon AR-10," "Aqualon AR-20," "Aqualon AR-3025" (a 25 wt % aqueous solution of "Aqualon AR-30"), and "Aqualon AR-1025" (a 25 wt % aqueous solution of "Aqualon AR-10") manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

[0091] An example of a commercially available polyoxyalkylene alkenyl ether ammonium sulfate is "Latemul PD-104" manufactured by Kao Corporation.

[0092] Commercially available α-sulfo-ω-(1-alkoxymethyl-2-(2-propenyloxy)ethoxy)-poly(oxy-1,2-ethanediyl)ammonium products include, for example, ADEKA CORPORATION under the trade names "ADEKA REASOAP SR-10" and "ADEKA REASOAP SR-20."

[0093] An example of a commercially available polyoxypropylene allyl ether phosphate ester is "ADEKA REASOAP PP-70" manufactured by ADEKA CORPORATION.

[0094] An example of a commercially available product of bis(polyoxyethylene phenyl ether) methacrylate sulfate is "Antox MS-60" manufactured by Nippon Nyukazai Co., Ltd.

[0095] Examples of nonionic surfactants having a vinyl group include polyoxyethylene styrenated propenyl phenyl ether, polyoxyethylene-1-(allyloxymethyl) alkyl ether, and polyoxyalkylene alkenyl ether.

[0096] Commercially available polyoxyethylene styrenated propenyl phenyl ethers include, for example, trade names "Aqualon AN-10," "Aqualon AN-20," "Aqualon AN-30," and "Aqualon AN-5065" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.

[0097] Commercially available polyoxyethylene-1-(allyloxymethyl) alkyl ethers include, for example, trade names "Aqualon KN-10," "Aqualon KN-20," "Aqualon KN-30," and "Aqualon KN-5065" manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., and trade names "ADEKA REASOAP ER-10," "ADEKA REASOAP ER-20," "ADEKA REASOAP ER-30," and "ADEKA REASOAP ER-40" manufactured by ADEKA Corporation.

[0098] Commercially available polyoxyalkylene alkenyl ethers include, for example, trade names "Latemul PD-420," "Latemul PD-430," and "Latemul PD-450" manufactured by Kao Corporation.

[0099] The surfactant may be used in any appropriate amount as long as it does not impair the effects of the present invention, and the amount used is preferably 0.001 to 5 parts by weight, more preferably 0.005 to 3 parts by weight, and even more preferably 0.01 to 1 part by weight, relative to 100 parts by weight of the aqueous phase.

[0100] In addition to the above-mentioned components, the aqueous phase may contain any other appropriate components as long as the effects of the present invention are not impaired.

[0101] As a method for mixing the oil phase and the aqueous phase, any appropriate method can be adopted as long as it can carry out suspension polymerization and does not impair the effects of the present invention.

[0102] The suspension is prepared by mixing and stirring the oil phase and the aqueous phase. Typically, this is done by dispersing the oil phase in the aqueous phase. Any appropriate dispersion method can be used to disperse the oil phase in the aqueous phase, as long as it allows the oil phase to exist in droplet form in the aqueous phase, as long as it does not impair the effects of the present invention. A typical dispersion method is a dispersion method using a homogenizer, such as an ultrasonic homogenizer or a high-pressure homogenizer.

[0103] For example, in the production method according to an embodiment of the present invention, it is preferable that the polymerization step includes dispersing the oil phase in the aqueous phase, and then emulsifying the aqueous phase at a pressure of 1 MPa to 200 MPa using a high-pressure emulsifier.

[0104] The polymerization temperature may be any suitable temperature suitable for suspension polymerization, within a range that does not impair the effects of the present invention, such as 30°C to 95°C.

[0105] The polymerization time may be any appropriate time suitable for suspension polymerization, as long as it does not impair the effects of the present invention. Such a polymerization time is preferably 1 hour to 20 hours.

[0106] Post-heating, which is preferably carried out after polymerization, is a treatment suitable for obtaining hollow resin particles with a high degree of perfection.

[0107] The temperature for post-heating preferably carried out after polymerization can be any appropriate temperature within a range that does not impair the effects of the present invention, and is preferably 50°C to 120°C.

[0108] The post-heating time preferably carried out after polymerization can be any appropriate time within the range that does not impair the effects of the present invention, and is preferably 1 to 10 hours.

[0109] The slurry containing the particles obtained by the polymerization step can be subjected to distillation, solvent removal, filtering, washing, drying, classification, etc., as needed, to obtain the particles.

[0110] The particles obtained in the polymerization step preferably have a number of particles with a particle diameter of 10 μm or more (number of coarse particles with a particle diameter of 10 μm or more) of 80 or less per 1,000,000 particles, as determined using a flow particle image analyzer under measurement condition A below. (Measurement condition A) Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00

[0111] The number of coarse particles having a particle diameter of 10 μm or more in the particles obtained in the polymerization step, as determined by a flow particle image analyzer under measurement condition A, is more preferably 60 or less, even more preferably 50 or less, and particularly preferably 45 or less.

[0112] Furthermore, it is preferable that the proportion of particles having a particle diameter of 10 μm or more (proportion of particles having a particle diameter of 10 μm or more) obtained in the polymerization step by the Coulter counter method (aperture diameter 50 μm) is 1.0% by volume or less relative to the total number of particles having a particle diameter of 1 μm to 30 μm.

[0113] The content of particles having a particle size of 10 μm or more among the particles obtained in the polymerization step is more preferably 0.70% by volume or less, even more preferably 0.60% by volume or less, and particularly preferably 0.50% by volume or less.

[0114] In order to obtain hollow resin particles with an even smaller number of coarse particles, it is preferable to include a classification step in which the particles obtained in the polymerization step are classified. The classification step may include at least one selected from the group consisting of dry classification and wet classification. The classification method is not particularly limited, and classification can be performed using known means such as a sieve, a mesh, a nonwoven fabric filter, centrifugation, or air classification. In the classification step, the slurry containing the particles obtained in the polymerization step may be subjected to steps such as solvent removal, washing, and drying as necessary, and then the particles may be classified by air classification. Alternatively, the slurry may be subjected to wet classification using a filter with a desired absolute filtration accuracy (e.g., an absolute filtration accuracy of 10 μm or less), and then steps such as solvent removal, washing, and drying as necessary. According to the above configuration, hollow resin particles with an even smaller number of coarse particles can be obtained.

[0115] The particles obtained in the classification step preferably have a number of coarse particles having a particle diameter of 10 μm or more, as determined by a flow particle image analyzer under the above measurement condition A, of 45 or less, more preferably 40 or less, more preferably 30 or less, more preferably 20 or less, more preferably 10 or less, even more preferably 5 or less, particularly preferably 3 or less, and most preferably 1 or less, and may even be 0. According to the above configuration, hollow resin particles having an extremely small number of coarse particles and excellent particle strength can be obtained.

[0116] The particles obtained in the classification step preferably have a number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm, as determined using a flow particle image analyzer under the above measurement condition A, of 55 or less, more preferably 50 or less, more preferably 40 or less, more preferably 30 or less, even more preferably 20 or less, particularly preferably 15 or less, and most preferably 10 or less. According to the above configuration, hollow resin particles having superior particle strength can be obtained. [Example]

[0117] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0118] <Measurement of volume average particle size> The volume average particle size was measured using a Coulter Multisizer TM Measurements were performed using a Multisizer 4e (a measuring device manufactured by Beckman Coulter, Inc.). TM 4e was performed with the aperture calibrated according to the user's manual. The aperture used for measurement was selected appropriately depending on the size of the particles to be measured. The Current (aperture current) and Gain were set appropriately depending on the size of the selected aperture. For example, if an aperture with a size of 50 μm was selected, the Current (aperture current) was set to -800 and the Gain to 4. The measurement sample was prepared by dispersing 0.1 g of particles in 10 ml of 0.1 wt % polyoxyethylene sorbitan monolaurate "Tween 20" aqueous solution using a touch mixer (Yamato Scientific Co., Ltd., "TOUCHMIXER MT-31") and an ultrasonic cleaner (Velvoclear Co., Ltd., "ULTRASONIC CLEANER VS-150") to prepare a dispersion. During the measurement, the beaker was gently stirred to prevent air bubbles from being introduced, and the measurement was stopped when 100,000 particles had been measured. The volume-average particle diameter was confirmed from the volume-based particle size distribution obtained from the measurement results.

[0119] <Coefficient of variation of volume average particle size> The coefficient of variation (CV value) of the volume average particle size was calculated by the following formula (1). Coefficient of variation [%] = (standard deviation of particle size distribution based on particle volume ÷ volume average particle diameter of particles) × 100 (1)

[0120] <Measurement of the number of coarse particles> [Number of particles with a particle diameter of 10 μm or more / Number of particles with a particle diameter of 8 μm or more but less than 10 μm] The number of coarse particles with a particle diameter of 10 μm or more and the number of coarse particles with a particle diameter of 8 μm or more and less than 10 μm were measured using a flow particle image analyzer. The flow particle image analyzer used was an FPIA-3000S (manufactured by Sysmex Corporation). Either a Paasche analyzer (manufactured by Hosokawa Micron Corporation) or a FPIA-3000S (manufactured by Hosokawa Micron Corporation) could also be used. A surfactant solution was prepared by adding 0.01 parts of surfactant (dodecylbenzenesulfonate) to 4.94 parts of ion-exchanged water. 0.06 parts of hollow resin particles were added to the surfactant solution, and the hollow resin particles were dispersed in the surfactant solution by applying ultrasonic waves for 10 minutes using a disperser (ultrasonic cleaner (VS-150, manufactured by Vervoclear)). An aqueous dispersion of hollow resin particles for measurement was obtained. The obtained aqueous dispersion of hollow resin particles was introduced into a flow particle image analyzer (FPIA-3000S, manufactured by Sysmex Corporation, equipped with a standard objective lens (10x)) and measured under the following measurement conditions: Particle Sheath (PSE-900A, manufactured by Sysmex Corporation) was used as the sheath liquid. Measurement mode: HPF mode Particle size measurement range (sphere equivalent volume basis): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00 Before starting the measurement, the flow particle image analyzer was automatically focused using a suspension of standard polymer particles (for example, Thermo Fisher Scientific 5200A (standard polystyrene particles diluted with ion-exchanged water)). The circularity is a value obtained by dividing the perimeter calculated from the diameter of a perfect circle having the same projected area as the image of the hollow resin particle by the perimeter of the image of the hollow resin particle. The circle-equivalent diameter (particle diameter) of 100,000 particles was measured within a particle circularity measurement range of 0.97 to 1.0, and the number of hollow resin particles having a particle diameter of 10.0 μm or more and the number of hollow resin particles having a particle diameter of 8 μm or more but less than 10 μm were counted. Here, the number of hollow resin particles having a particle diameter of 8 μm or more but less than 10 μm is the number of hollow resin particles having a particle diameter of 8.0 μm or more but less than 10 μm minus the number of hollow resin particles having a particle diameter of 10.0 μm from the number of hollow resin particles having a particle diameter of 8.0 μm or more but less than 10.0 μm. These operations were repeated 10 times (i.e., a total of 1,000,000 particle sizes were measured), and the total numbers of hollow resin particles with a volume average particle size of 10.0 μm or more and hollow resin particles with a particle size of 8 μm or more but less than 10 μm were counted. These sums were designated as the "number of coarse particles with a particle size of 10 μm or more" and the "number of coarse particles with a particle size of 8 μm or more but less than 10 μm," respectively.

[0121] <Proportion of particles with a diameter of 10 μm or more> The proportion of particles with a particle size of 10 μm or more to the total of particles with a particle size of 1 μm to 30 μm was measured using a Coulter Multisizer in the same way as for the measurement of the volume average particle size. TM Using a 4e (measuring device manufactured by Beckman Coulter, Inc.), a 50 μm diameter aperture was selected and 100,000 particles were measured. In the volumetric particle size distribution obtained from the measurement results, the volumetric proportion of particles with a particle diameter of 10 μm or more relative to particles with a particle diameter of 1 μm to 30 μm was confirmed.

[0122] <Internal structure of hollow resin particles> The internal structure of hollow resin particles was confirmed by cross-sectional SEM of hollow resin particles. Hollow resin particles were mixed with photocurable resin "D-800" (manufactured by JEOL Ltd.) and cured by irradiating with ultraviolet light. The cured material was then cut with nippers, and the cross-section was smoothed using a cutter. The sample was then coated using a sputtering device (JEOL Ltd., "Auto Fine Coater JFC-1300"). The cross-section of the sample was then photographed using a secondary electron detector on a scanning electron microscope (Hitachi High-Technologies Corporation, "SU1510") at 3000x magnification. A single-hollow structure was defined as a particle with a void space composed of only a single air layer, with the resin portion surrounding the void space as a shell. A porous structure was defined as a particle with a void space composed of multiple air layers, with the resin portion surrounding the void space as a shell.

[0123] <Porosity> The porosity of the hollow resin particles was obtained from the apparent density and true density of the hollow resin particles. The apparent density of the hollow resin particles was measured using a vibration densitometer (trade name "DMA1001" manufactured by Anton Paar). Specifically, the hollow resin particles and a dispersion medium (trade name "ARUFON UP-1020" manufactured by Toa Gosei Co., Ltd., density 1.027 g / cm) were mixed together so that the proportion of hollow resin particles was 2% by weight. 3 The mixture (25°C) was degassed and stirred using a degassing mixer (Thinky Corporation, trade name "Awatori Rentaro ARE-100") to prepare a mixture for evaluation. The mixture for evaluation was filled into the measurement cell of a vibration density meter, and the vibration frequency of the mixture in the measurement cell was measured to calculate the density of the mixture using the following formula (2). The apparent density of the air-encapsulated hollow resin particles was calculated using the following formula (3) from the densities of the mixture and dispersion medium and their respective weight proportions in the mixture. The true density of the hollow resin particles was measured and calculated using a vibration densitometer (trade name "DMA1001" manufactured by Anton Paar) in the same manner as the apparent density. Here, by using pre-pulverized hollow resin particle pieces instead of hollow resin particles, the density of the resin portion excluding the void portion, i.e., the true density, was calculated.

number

number

[0124] <Evaluation of particle cracking> The particles were pulverized at 0.4 MPa using a jet mill (Current Jet, manufactured by Nisshin Engineering Inc.). The surfaces of the pulverized particles were coated using a sputtering device (Auto Fine Coater JFC-1300, manufactured by JEOL Ltd.) to prepare a sample. The appearance of the sample was then photographed using a secondary electron detector on a scanning electron microscope (SU1510, manufactured by Hitachi High-Technologies Corporation). At this time, the magnification was set to 1000x, and five randomly selected points were photographed. The particle cracking was evaluated based on the number of particles found to be cracked or chipped. The evaluation criteria were as follows: ◎: No cracks or chips were found in any particles. ◯: Cracks or chips were observed in 1 to 3 particles. △: Cracks or chips were observed in 4 to 5 particles. ×: Cracks or chips were found in 5 or more particles.

[0125] <Evaluation of Total K and Na Content> As metal residues in the hollow resin particles, the contents of K element and Na element were measured. Specifically, about 1.0 g of the accurately weighed hollow resin particle sample was heated and ashed at 500 °C for 1 hour. The obtained ash was mixed with 1 mL of conc. hydrochloric acid (Ultrapur-100 ultra-high purity reagent manufactured by Kanto Chemical Co., Inc.). After filtering the insoluble matter in the mixture with ADVANTEC No. 7 filter paper, the filtrate was made up to 25 mL with distilled water and used as the test solution. For the test solution, ICP emission spectrometry under the following conditions was performed. The concentrations of each measured element were determined from the calibration curve prepared in advance. The component amounts of each measured element were calculated from the following formula. Component amount [ppm] = Measured element concentration [μg / mL] × 25 [mL] ÷ Sample amount [g] From the component amounts of each measured element, the total contents of K and Na were calculated. Here, in calculating the total contents of K and Na, elements with measurement results below the quantification limit were not taken into consideration. That is, the sum of the K component amount and Na component amount greater than the quantification limit was taken as the value of the total K content and total Na content. The quantification limit of the K element was 0.5 ppm, and the quantification limit of the Na element was 0.3 ppm. (ICP Measurement Conditions) Measuring device: "ICPE-9000" multi-type ICP emission spectrometer manufactured by Shimadzu Corporation Measured elements: K, Na Observation direction: Axial direction RF output: 1.20 kw Carrier gas flow rate: 0.7 L / min Plasma gas flow rate: 10.0 L / min Auxiliary gas flow rate: 0.6 L / min Exposure time: 30 seconds Standard solution for calibration curve: "XSTC-13" general-purpose mixed standard solution of 31 elements (base 5% HNO3) each about 10 mg / L, "XSTC-8" general-purpose mixed standard solution of 13 elements (base H2O / trace HF) each about 10 mg / L manufactured by SPEX Industries, Inc., USA (Ashing Conditions) Measuring device: Microwave muffle furnace Phoenix large-capacity type (manufactured by CEM Corporation) Ashing conditions: 500°C x 1 hour (sample weight = approx. 1.0 g)

[0126] Example 1 In a beaker, 320 parts by weight of a 2.0 wt % aqueous dispersion of magnesium pyrophosphate and 0.15 parts by weight of sodium lauryl sulfate were mixed with stirring to prepare an aqueous phase. Next, in a beaker different from the aqueous phase, 12 parts by weight of styrene, 7.1 parts by weight of ethylvinylbenzene, 30 parts by weight of divinylbenzene, 23 parts by weight of heptane, and a highly branched hydrocarbon wax (VYBAR manufactured by Nucera Solutions) were added. TM An oil phase was prepared by stirring and mixing 5 parts by weight of 260, Mn: 2,600 to 4,000, and 0.75 parts by weight of a polymerization initiator. The resulting oil phase was poured into the beaker containing the aqueous phase and stirred for 10 minutes at 8,000 rpm using a TK Homomixer (Primix Corporation) to obtain a pre-emulsion. The pre-emulsion was then subjected to high-pressure emulsification using a coarse particle processing system (Yoshida Kikai Kogyo Co., Ltd., model "NVR-EM055-P20-0600-Exp") at a processing pressure of 18 MPa and an outlet pressure of 1 MPa to obtain a finely divided emulsion. The emulsion was then poured into a pressure-resistant polymerization vessel equipped with a stirrer, thermometer, and cooling mechanism. Nitrogen gas was blown in for 3 minutes to create an inert gas atmosphere, and the temperature was then raised to 75°C and polymerization was carried out for 4 hours. The temperature was then further raised to 90°C and polymerization reaction was carried out for 10 hours. After the polymerization process was completed, hydrochloric acid was added to decompose the magnesium pyrophosphate, and the mixture was dehydrated using a centrifuge and washed with ion-exchanged water to obtain a cake containing hollow resin particles. This cake was dried in a vacuum oven under reduced pressure at 90°C for 48 hours to obtain particles (A1). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A1) was 35, and the number of coarse particles having a particle diameter of 10 μm or more was 20. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A1) was 0.32% by volume. When the cross section of the particle (A1) was observed by SEM, it was confirmed that the internal structure had a single hollow portion. The particles (A1) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B1). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B1) was 7. The total content of K and Na in the hollow resin particles (B1) was 13 ppm. Other physical properties and evaluation results of the hollow resin particles (B1) are shown in Table 3.

[0127] Example 2 Particles (A2) were obtained in the same manner as in the production of particles (A1) in Example 1, except that the polymerization initiator was changed as shown in Table 1. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A2) was 36, and the number of coarse particles having a particle diameter of 10 μm or more was 15. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A2) was 0.24% by volume. Cross-sectional SEM observation of particle (A2) confirmed that the internal structure had a single hollow portion. The particles (A2) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B2). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B2) was 9. The total content of K and Na in the hollow resin particles (B2) was 9 ppm. Other physical properties and evaluation results of the hollow resin particles (B2) are shown in Table 3.

[0128] Example 3 As shown in Table 1, particles (A3) were obtained in the same manner as particles (A1) in Example 1, except that polyphenylene ether (Noryl (registered trademark) SA90 resin, Mn: 1,900, manufactured by SABIC) was used instead of the highly branched hydrocarbon wax, the polymerization initiator was changed, and the initial polymerization temperature was changed from 75°C to 60°C. In the obtained particles (A3), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 38, and the number of coarse particles having a particle diameter of 10 μm or more was 22. In the particles (A3), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.34 vol %. Cross-sectional SEM observation of particle (A3) confirmed that the internal structure had a single hollow portion. The particles (A3) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B3). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B3) was 9. The total content of K and Na in the hollow resin particles (B3) was 10 ppm. Other physical properties and evaluation results of the hollow resin particles (B3) are shown in Table 3.

[0129] Example 4 Particles (A4) were obtained in the same manner as particles (A1) in Example 1, except that polystyrene (Mn: 70,000 to 90,000) was used instead of the highly branched hydrocarbon wax and the polymerization initiator was changed, as shown in Table 1. In the obtained particles (A4), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 28, and the number of coarse particles having a particle diameter of 10 μm or more was 21. In the particles (A4), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.32 vol %. Cross-sectional SEM observation of particle (A4) confirmed that the internal structure had a single hollow space. The particles (A4) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B4). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B4) was 7. The total content of K and Na in the hollow resin particles (B4) was 11 ppm. Other physical properties and evaluation results of the hollow resin particles (B4) are shown in Table 3.

[0130] Example 5 Particles (A5) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 1. In the obtained particles (A5), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 38, and the number of coarse particles having a particle diameter of 10 μm or more was 23. In the particles (A5), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.32 vol %. Cross-sectional SEM observation of particle (A5) confirmed that the internal structure had a single hollow portion. The particles (A5) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B5). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B5) was 8. The total content of K and Na in the hollow resin particles (B5) was 12 ppm. Other physical properties and evaluation results of the hollow resin particles (B5) are shown in Table 3.

[0131] Example 6 Particles (A6) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 1. In the obtained particles (A6), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 41, and the number of coarse particles having a particle diameter of 10 μm or more was 23. In the particles (A6), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.32 vol %. Cross-sectional SEM observation of particle (A6) confirmed that the internal structure had a single hollow portion. The particles (A6) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B6). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B6) was 9. The total content of K and Na in the hollow resin particles (B6) was 10 ppm. Other physical properties and evaluation results of the hollow resin particles (B6) are shown in Table 3.

[0132] Example 7 Particles (A7) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 1. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A7) was 38, and the number of coarse particles having a particle diameter of 10 μm or more was 26. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A7) was 0.38% by volume. Cross-sectional SEM observation of particle (A7) confirmed that the internal structure had a single hollow portion. The particles (A7) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B7). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B7) was 7. The total content of K and Na in the hollow resin particles (B7) was 9 ppm. Other physical properties and evaluation results of the hollow resin particles (B7) are shown in Table 3.

[0133] Example 8 Particles (A8) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 1. In the obtained particles (A8), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 51, and the number of coarse particles having a particle diameter of 10 μm or more was 39. In the particles (A8), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.48% by volume. Cross-sectional SEM observation of particle (A8) confirmed that the internal structure had a single hollow portion. The particles (A8) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B8). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B8) was 14. The total content of K and Na in the hollow resin particles (B8) was 13 ppm. Other physical properties and evaluation results of the hollow resin particles (B8) are shown in Table 3.

[0134] Example 9 Particles (A9) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 1. In the obtained particles (A9), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 39, and the number of coarse particles having a particle diameter of 10 μm or more was 24. In the particles (A9), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.30% by volume. Cross-sectional SEM observation of the particle (A9) confirmed that the internal structure had a single hollow portion. The particles (A9) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B9). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B9) was 8. The total content of K and Na in the hollow resin particles (B9) was 12 ppm. Other physical properties and evaluation results of the hollow resin particles (B9) are shown in Table 3.

[0135] Example 10 Particles (A10) were obtained in the same manner as in the production of particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 1. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A10) was 25, and the number of coarse particles having a particle diameter of 10 μm or more was 12. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A10) was 0.38% by volume. Cross-sectional SEM observation of the particle (A10) confirmed that the internal structure had a single hollow space. The particles (A10) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B10). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B10) was 5. The total content of K and Na in the hollow resin particles (B10) was 12 ppm. Other physical properties and evaluation results of the hollow resin particles (B10) are shown in Table 3.

[0136] Example 11 Particles (A11) were obtained in the same manner as in the production of particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A11) was 24, and the number of coarse particles having a particle diameter of 10 μm or more was 25. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A11) was 0.32% by volume. Cross-sectional SEM observation of the particle (A11) confirmed that the internal structure had a single hollow portion. The particles (A11) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B11). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B11) was 10. The total content of K and Na in the hollow resin particles (B11) was 14 ppm. Other physical properties and evaluation results of the hollow resin particles (B11) are shown in Table 3.

[0137] Example 12 Particles (A12) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A12) was 51, and the number of coarse particles having a particle diameter of 10 μm or more was 37. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A12) was 0.44% by volume. Cross-sectional SEM observation of particle (A12) confirmed that the internal structure had a single hollow portion. The particles (A12) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B12). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B12) was 13. The total content of K and Na in the hollow resin particles (B12) was 12 ppm. Other physical properties and evaluation results of the hollow resin particles (B12) are shown in Table 3.

[0138] Example 13 Particles (A13) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. In the obtained particles (A13), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 51, and the number of coarse particles having a particle diameter of 10 μm or more was 38. In the particles (A13), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.49 vol %. Cross-sectional SEM observation of particle (A13) confirmed that the internal structure had a single hollow portion. The particles (A13) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B13). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B13) was 15. The total content of K and Na in the hollow resin particles (B13) was 10 ppm. Other physical properties and evaluation results of the hollow resin particles (B13) are shown in Table 3.

[0139] Example 14 Particles (A14) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A14) was 27, and the number of coarse particles having a particle diameter of 10 μm or more was 18. The proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm in the particles (A14) was 0.28% by volume. Cross-sectional SEM observation of particle (A14) confirmed that the internal structure had a single hollow space. The particles (A14) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B14). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B14) was 6. The total content of K and Na in the hollow resin particles (B14) was 11 ppm. Other physical properties and evaluation results of the hollow resin particles (B14) are shown in Table 3.

[0140] Example 15 Particles (A15) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. In the obtained particles (A15), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 37, and the number of coarse particles having a particle diameter of 10 μm or more was 19. In the particles (A15), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.48% by volume. Cross-sectional SEM observation of the particle (A15) confirmed that the internal structure had a single hollow space. The particles (A15) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B15). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B15) was 9. The total content of K and Na in the hollow resin particles (B15) was 9 ppm. Other physical properties and evaluation results of the hollow resin particles (B15) are shown in Table 3.

[0141] Example 16 Particles (A16) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. In the obtained particles (A16), the number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm was 42, and the number of coarse particles having a particle diameter of 10 μm or more was 41. In the particles (A16), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.49 vol %. Cross-sectional SEM observation of particle (A16) confirmed that the internal structure had a single hollow space. The particles (A16) were subjected to a 10 μm top cut using an air classifier (manufactured by Nisshin Engineering Inc., "Turbo Classifier (registered trademark) TC-15NS") to obtain hollow resin particles (B16). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B16) was 14. The total content of K and Na in the hollow resin particles (B16) was 14 ppm. Other physical properties and evaluation results of the hollow resin particles (B16) are shown in Table 3.

[0142] Example 17 Particles (A17) were obtained in the same manner as for particles (A1) in Example 1, except that the composition of the oil phase was changed as shown in Table 2. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (A17) was 36, and the number of coarse particles having a particle diameter of 10 μm or more was 15. In the particles (A17), the proportion of particles having a particle diameter of 10 μm or more to particles having a particle diameter of 1 μm to 30 μm was 0.24% by volume. Cross-sectional SEM observation of particle (A17) confirmed that the internal structure had a single hollow space. In the production process of particles (A17), after the polymerization step was completed, the slurry containing particles (A17) was wet classified by passing it through a filter (BM-10, manufactured by JNC Filter Co., Ltd.) with an absolute filtration accuracy of 10 μm. Hydrochloric acid was added to the passed slurry to decompose the magnesium pyrophosphate, and the mixture was dehydrated using a centrifuge and washed with ion-exchanged water to obtain a cake containing hollow resin particles. The cake was dried in a vacuum oven under reduced pressure at 90°C for 48 hours to obtain hollow resin particles (B17). The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained hollow resin particles (B17) was three. The total content of K and Na in the hollow resin particles (B17) was 13 ppm. Other physical properties and evaluation results of the hollow resin particles (B17) are shown in Table 3.

[0143] (Comparative Example 1) In a beaker, 320 parts by weight of a 2.0 wt % aqueous dispersion of magnesium pyrophosphate and 0.15 parts by weight of sodium lauryl sulfate were mixed with stirring to prepare an aqueous phase. Next, in a beaker different from the aqueous phase, 3 parts by weight of styrene, 3.6 parts by weight of ethylvinylbenzene, 15.4 parts by weight of divinylbenzene, 50 parts by weight of heptane, 1 part by weight of highly branched hydrocarbon wax (Mn: 2,600), and 0.50 parts by weight of initiator were stirred and mixed to prepare an oil phase. The resulting oil phase was poured into the beaker containing the aqueous phase and stirred for 10 minutes at 8,000 rpm using a TK Homomixer (Primix Corporation) to obtain a pre-emulsion. The pre-emulsion was then subjected to high-pressure emulsification using a coarse particle processing system (Yoshida Kikai Kogyo Co., Ltd., model "NVR-EM055-P20-0600-Exp") at a processing pressure of 18 MPa and an outlet pressure of 1 MPa to obtain a finely divided emulsion. The emulsion was then poured into a pressure-resistant polymerization vessel equipped with a stirrer, thermometer, and cooling mechanism. Nitrogen gas was blown in for 3 minutes to create an inert gas atmosphere, and the temperature was then raised to 75°C and polymerization was carried out for 4 hours. The temperature was then further raised to 90°C and polymerization reaction was carried out for 10 hours. After the polymerization process was completed, hydrochloric acid was added to decompose the magnesium pyrophosphate, and the mixture was dehydrated using a centrifuge and washed with ion-exchanged water to obtain a cake containing hollow resin particles. The cake was dried in a vacuum oven at 90°C under reduced pressure for 48 hours to obtain particles. The obtained particles were sieved using a wire mesh with 45 µm openings. The particles that fell through the wire mesh were designated as hollow resin particles (C1) of Comparative Example 1. When the cross section of the obtained hollow resin particle (C1) was observed by SEM, it was confirmed that the internal structure had a single hollow portion. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the hollow resin particles (C1) was 101. Other physical properties and evaluation results of the hollow resin particles (C1) are shown in Table 3. Air classification of the hollow resin particles (C1) was attempted under the same conditions as for the particles (A1) in Example 1, but cracks and chips were found on the particle surface after classification.

[0144] (Comparative Example 2) Particles (C2) were obtained in the same manner as hollow resin particles (C1) of Comparative Example 1, except that the composition of the oil phase was changed as shown in Table 2. The obtained particles (C2) were confirmed to have irregular shapes and were not hollow. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the obtained particles (C2) was 98. Other physical properties and evaluation results of particles (C2) are shown in Table 3. However, since particles (C2) were confirmed to be deformed, evaluation of particle cracking was not performed.

[0145] (Comparative Example 3) Hollow resin particles (C3) were obtained in the same manner as in the hollow resin particles (C1) of Comparative Example 1, except that the composition of the oil phase was changed as shown in Table 2. When the cross section of the obtained hollow resin particle (C3) was observed by SEM, it was confirmed that the hollow resin particle had a porous structure with the hollow surrounded by a shell. The number of coarse particles having a particle diameter of 8 μm or more and less than 10 μm in the hollow resin particles (C3) was 116. Other physical properties and evaluation results of the hollow resin particles (C3) are shown in Table 3.

[0146] [Table 1]

[0147] [Table 2]

[0148] The abbreviations in Tables 1 and 2 are as follows: LPO: Lauroyl peroxide (NOF Corporation, product name "Perloyl L") BPO: Benzoyl peroxide (manufactured by NOF Corporation, product name "Niper BW") t-BuPEHx: tert-butyl-2-ethylperoxyhexanoate (NOF Corporation, trade name "Perbutyl O") ADVN: 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "V-65") DAMP: 2,2'-azobis(2-methylpropionate)dimethyl (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., trade name "V-601")

[0149] [Table 3] [Industrial Applicability]

[0150] The hollow resin particles according to the embodiment of the present invention and the hollow resin particles obtained by the production method according to the embodiment of the present invention can be suitably used for semiconductor members and the like.

Claims

1. A hollow resin particle having a shell portion and a hollow portion surrounded by the shell portion, The porosity is 5 to 90%, The number of particles having a particle diameter of 10 μm or more per 1,000,000 particles determined using a flow particle image analyzer under the following measurement condition A is 10 or less. Hollow resin particles. (Measurement Condition A) Particle size measurement range (based on spherical equivalent volume): 0.5 μm to 200.0 μm Circularity measurement range: 0.97 to 1.00

2. the shell portion comprises a polymer (P1) obtained by polymerizing a radical polymerizable monomer component (M) through a reaction of a composition containing the radical polymerizable monomer component (M), The hollow resin particle according to claim 1 , wherein the radical polymerizable monomer component (M) comprises a crosslinkable monomer (a).

3. 3. The hollow resin particles according to claim 2, wherein the content of the crosslinkable monomer (a) in the radical polymerizable monomer component (M) is 20% by weight to 96% by weight.

4. The hollow resin particle according to claim 2 , wherein the radical polymerizable monomer component (M) contains a monofunctional monomer (b).

5. 5. The hollow resin particles according to claim 4, wherein the content of said monofunctional monomer (b) in said radical polymerizable monomer component (M) is 4% by weight to 80% by weight.

6. the composition comprises a polymer component (P2), The hollow resin particles according to claim 2, wherein the number average molecular weight of the polymer component (P2) is 500 to 200,000.

7. 7. The hollow resin particles according to claim 6, wherein the polymer component (P2) is 0.1 to 20 parts by weight when the total amount of the radical polymerizable monomer component (M) is 100 parts by weight.

8. 2. The hollow resin particles according to claim 1, having a volume average particle diameter of 0.1 μm to 5.0 μm.

9. 2. The hollow resin particles according to claim 1, wherein the coefficient of variation of the volume average particle diameter is 25% or less.

10. The hollow resin particles according to claim 1, which are used as an additive for semiconductor members.

11. A resin composition for a semiconductor member, comprising the hollow resin particles according to claim 10.

12. The hollow resin particles according to claim 1, which are used as an additive for optical materials.

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