Hollow resin particles, method for producing same, and application of same

Abstract

Provided are hollow resin particles having a shell part and a hollow portion surrounded by the shell part, the hollow resin particles having exceptional dielectric characteristics that are not affected by a high-temperature environment. Also provided is a method for producing the hollow resin particles. Furthermore provided is an application of the hollow resin particles.　Hollow resin particles according to an embodiment of the present invention have a shell part and a hollow portion surrounded by the shell part, wherein when a heating test under conditions I of 180°C and one hour is performed, the dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and the dielectric loss tangent Df2 at a measurement frequency of 10 GHz after the heating test under the conditions I satisfy the expression Df2 – Df1 ≤ 0.004.

Description

Hollow resin particles, their manufacturing method, and their uses

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

[0002] In order to increase the speed of information processing using electronic devices, attempts have been made to reduce the dielectric constant and dielectric loss tangent of the insulating layers of multilayer printed circuit boards. As part of these efforts, studies have been made to introduce voids into the resin layer by mixing hollow particles, each having a shell portion and a hollow portion surrounded by the shell portion, into a thermosetting resin, thereby reducing the dielectric constant and dielectric loss tangent.

[0003] Conventional hollow resin particles have been reported to be obtained by suspension polymerization of a monomer primarily composed of an acrylic polyfunctional monomer such as trimethylolpropane tri(meth)acrylate and an acrylic monofunctional monomer such as methyl acrylate together with a hydrophobic solvent (Patent Document 1). However, acrylic resins generally have high dielectric constants and dielectric loss tangents and insufficient heat resistance. For these reasons, the hollow particles described in Patent Document 1 are unsuitable for achieving a low dielectric constant and dielectric loss tangent for a resin layer.

[0004] Conventional hollow resin particles have been reported to be obtained by suspension polymerization of a polymerizable monomer containing a large amount of a crosslinkable hydrocarbon monomer such as divinylbenzene together with a hydrophobic solvent (Patent Document 2). However, hollow resin particles containing a large amount of divinylbenzene have a high dielectric loss tangent due to the large amount of vinyl groups remaining within the particles.

[0005] International Publication No. 2022-107674 International Publication No. 2023-074651

[0006] Conventional hollow resin particles suffer from oxidative degradation of resins in high-temperature environments, potentially deteriorating the dielectric properties of components incorporating the hollow resin particles. In particular, conventional hollow resin particles can deteriorate in dielectric constant and dielectric loss tangent when exposed to heat during processing, potentially preventing the components from achieving low dielectric constant and dielectric loss tangent. Therefore, there is a need for hollow resin particles that are not affected by high-temperature environments. The present invention has been made to solve the above problems, and its primary object is to provide hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion, which have excellent dielectric properties that are not affected by high-temperature environments. It also aims to provide a method for producing such hollow resin particles. It also aims to provide uses for such hollow resin particles.

[0007] [1] According to an embodiment of the present invention, hollow resin particles have a shell portion and a hollow portion surrounded by the shell portion, and when a heating test under Condition I is conducted at 180°C for 1 hour, the dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and the dielectric loss tangent Df2 at a measurement frequency of 10 GHz after the heating test under Condition I satisfy the following formula (1): Df2 - Df1 ≦ 0.004 (1) [2] The hollow resin particles described in [1] above may have a dielectric loss tangent Df1 of less than 0.002. [3] The hollow resin particles described in [1] or [2] above may have a relative dielectric constant of less than 1.5 at a measurement frequency of 10 GHz. [4] In the hollow resin particle according to any one of the above items [1] to [3], the shell portion may contain a polymer (P) obtained by reacting a composition (A) containing a crosslinkable monomer (a) and at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by formula (2). [5] In the hollow resin particle described in [4] above, the crosslinkable monomer (a) may be an aromatic crosslinkable monomer. [6] In the hollow resin particle described in [5] above, when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is 100 parts by weight, the aromatic crosslinkable monomer may be 1 part by weight to 50 parts by weight. [7] In the hollow resin particle described in any one of [4] to [6] above, the monofunctional monomer (b) may be at least one selected from the group consisting of styrene, α-methylstyrene, ethylvinylbenzene, vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, vinylbiphenyl, vinylnaphthalene, and acenaphthylene. [8] In the hollow resin particle described in any one of [4] to [7] above, the shell portion may contain 0 parts by weight to 10 parts by weight of the hydrocarbon resin (B) relative to 100 parts by weight of the total amount of the polymer (P) and the hydrocarbon resin (B). [9] The hollow resin particles according to any one of [1] to [8] above may have a 5% thermal weight loss temperature of 270°C or higher when heated at a rate of 10°C / min in an air atmosphere.

[10] The hollow resin particles according to any one of [1] to [9] above may have a volume average particle diameter of 0.1 μm to 30 μm.

[11] The hollow resin particles according to any one of [1] to

[10] above may have a dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and a dielectric loss tangent Df3 at a measurement frequency of 10 GHz after the heating test under condition II at 260°C for 2 minutes, which satisfy formula (3). Df3-Df1≦0.004 (3)

[12] 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 when a heating test under Condition II at 260°C for 2 minutes is performed, a dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and a dielectric loss tangent Df3 at a measurement frequency of 10 GHz after the heating test under Condition II satisfy formula (3).Df3 - Df1 ≦ 0.004 (3)

[13] The hollow resin particles described in

[12] above may have a dielectric loss tangent Df1 of less than 0.002.

[14] The hollow resin particles described in any one of [1] to

[13] above may be used in a resin composition for a semiconductor member.

[15] A resin composition for a semiconductor member according to an embodiment of the present invention includes the hollow resin particles described in any one of [1] to

[13] above.

[16] A method for producing hollow resin particles according to an embodiment of the present invention includes reacting a composition (A) containing a crosslinkable monomer (a) and at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by formula (2) in an aqueous medium in the presence of a non-reactive solvent, so that the crosslinkable monomer (a) is 1 part by weight to 50 parts by weight when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is 100 parts by weight.

[0008] According to an embodiment of the present invention, hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion and having excellent dielectric properties that are not affected by high-temperature environments 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.

[0009] FIG. 1 is a schematic cross-sectional view illustrating the structure of a hollow portion. FIG. 2 is a SEM photograph of a cross section of a particle (1) obtained in Example 1. FIG. 3 is a SEM photograph of a cross section of a particle (2) obtained in Example 2. FIG. 4 is a SEM photograph of a cross section of a particle (3) obtained in Example 3. FIG. 5 is a SEM photograph of a cross section of a particle (4) obtained in Example 4. FIG. 6 is a SEM photograph of a cross section of a particle (5) obtained in Example 5. FIG. 7 is a SEM photograph of a cross section of a particle (6) obtained in Example 6. FIG. 8 is a SEM photograph of a cross section of a particle (7) obtained in Example 7. FIG. 9 is a SEM photograph of a cross section of a particle (C1) obtained in Comparative Example 1. FIG. 10 is a SEM photograph of a cross section of a particle (C2) obtained in Comparative Example 2.

[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 term "(meth)acrylic" means "acrylic and / or methacrylic", the term "(meth)acrylate" means "acrylate and / or methacrylate", the term "(meth)allyl" means "allyl and / or methallyl", and the term "(meth)acryloyl" means "acryloyl and / or methacryloyl".

[0012] <<1. Hollow Resin Particles>> <<1-1. Structure and Properties of Hollow Resin Particles>> 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. When the hollow resin particles according to an embodiment of the present invention are subjected to a heating test under Condition I at 180°C for 1 hour, the dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and the dielectric loss tangent Df2 at a measurement frequency of 10 GHz after the heating test under Condition I satisfy the following formula (1): Df2 - Df1 ≦ 0.004 (1)

[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. The hollow portion preferably has a porous structure. FIG. 1( a) is a schematic cross-sectional view of a hollow resin particle whose hollow portion consists of a single hollow region. FIG. 1( b) is a schematic cross-sectional view of a hollow resin particle whose hollow portion consists of multiple hollow regions. FIG. 1( c) is a schematic cross-sectional view of a hollow resin particle whose hollow portion consists of a porous structure. When the hollow portion consists of multiple hollow regions, the hollow portion has multiple closed pores as shown in FIG. 1( b). When the hollow portion has a porous structure, the hollow portion has interconnected pores like a three-dimensional network structure. When the hollow portion has a porous structure, for example, the hollow portion may consist of a single hollow region (interconnected pores) or a mixture of multiple closed pores and one or more interconnected pores.

[0015] In hollow resin particles according to an embodiment of the present invention, in which the dielectric loss tangent Df1 before the heating test and the dielectric loss tangent Df2 after the heating test under condition I satisfy the relationship of formula (1) above, the difference between Df2 and Df1 is sufficiently small, so that an increase in the dielectric loss tangent due to exposure to high temperatures is suppressed. According to the above configuration, deterioration of dielectric properties due to high-temperature environments is reduced, and hollow resin particles having excellent dielectric properties that are not affected by high-temperature environments can be realized. As a result, resin compositions using hollow resin particles according to an embodiment of the present invention can exhibit excellent dielectric properties that are not affected by high-temperature environments. Examples of excellent dielectric properties include a low dielectric constant and a low dielectric loss tangent.

[0016] The dielectric loss tangent Df1 before the heating test is preferably less than 0.002, which allows the hollow resin particles according to the embodiment of the present invention to have even more excellent dielectric properties.

[0017] The lower limit of the difference between Df2 and Df1, expressed as Df2-Df1, is, for example, not less than -0.01, and preferably not less than 0. The difference between Df2 and Df1 is preferably not more than 0.003, more preferably not more than 0.002, even more preferably not more than 0.001, and particularly preferably not more than 0.0005.

[0018] When the hollow resin particles according to an embodiment of the present invention are subjected to a heating test under Condition II at 260° C. for 2 minutes, the dielectric loss tangent Df1 and the dielectric loss tangent Df3 at a measurement frequency of 10 GHz after the heating test under Condition II preferably satisfy the following formula (3): Df3−Df1≦0.004 (3)

[0019] In another aspect, the present invention provides hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion, wherein, when a heating test under Condition II is conducted, a dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and a dielectric loss tangent Df3 at a measurement frequency of 10 GHz after the heating test under Condition II satisfy formula (3).

[0020] Such hollow resin particles suppress an increase in dielectric loss tangent even under higher temperature conditions. According to the above configuration, hollow resin particles having excellent dielectric properties that are not affected by high-temperature environments can be realized. As a result, a resin composition using hollow resin particles according to an embodiment of the present invention can exhibit excellent dielectric properties that are not affected by high-temperature environments.

[0021] In this specification, the "dielectric loss tangent Df1 (before heating test)" refers to the dielectric loss tangent of the hollow resin particles in their initial state, i.e., before the heating test, i.e., not placed under the environment of Condition I or the environment of Condition II. Therefore, the above formula (1) shows the relationship of the amount of change in the dielectric loss tangent of the hollow resin particles from their initial value due to the heating test under Condition I, and the above formula (3) shows the relationship of the amount of change in the dielectric loss tangent of the hollow resin particles from their initial value due to the heating test under Condition II. The dielectric loss tangent Df1 is preferably less than 0.002, more preferably less than 0.0017.

[0022] The lower limit of the difference between Df3 and Df1, expressed as Df3-Df1, is, for example, not less than 0. The difference between Df3 and Df1 is preferably not more than 0.0035, more preferably not more than 0.003, even more preferably not more than 0.0025, and particularly preferably not more than 0.002.

[0023] The volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is preferably 0.1 μm to 100 μm, more preferably 0.2 μm to 50.0 μm, even more preferably 0.3 μm to 30.0 μm, and particularly preferably 0.4 μm to 20.0 μm. The volume average particle diameter of the hollow resin particles according to an embodiment of the present invention may be 0.1 μm to 30 μm. When the volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is within the above range, the effects of the present invention can be more effectively exhibited. If the volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is too small and outside the above range, the shell thickness becomes relatively thin, which may result in hollow resin particles that do not have sufficient strength. Furthermore, when the hollow resin particles are kneaded with a thermosetting resin, the thermosetting resin may penetrate into the hollow resin particles. If the volume average particle diameter of the hollow resin particles according to an embodiment of the present invention is too large and deviates from the above range, phase separation between the polymer and the solvent produced by polymerization of the monomer components during suspension polymerization may be difficult to occur, which may make it difficult to form the shell portion.

[0024] The coefficient of variation (CV value) of the particle size of the hollow resin particles according to an embodiment of the present invention is preferably 10% to 50%, more preferably 15% to 45%, even more preferably 18% to 42%, and particularly preferably 20% to 40%. When the coefficient of variation (CV value) of the particle size of the hollow resin particles according to an embodiment of the present invention is within the above range, the effects of the present invention can be more effectively achieved. If the coefficient of variation (CV value) of the particle size of the hollow resin particles according to an embodiment of the present invention is too small and outside the above range, when the hollow resin particles are kneaded with a thermosetting resin to form a resin composition, the hollow resin particles are difficult to disperse within the thermosetting resin, and for example, when a resin layer is formed from the resin composition, the thickness may vary. If the coefficient of variation (CV value) of the particle size of the hollow resin particles according to an embodiment of the present invention is too large and outside the above range, the amount of coarse particles may increase, making it difficult to form a thin film or causing thickness variation, for example, when a resin layer is formed from the resin composition.

[0025] The hollow resin particles according to an embodiment of the present invention preferably have a 5% thermal weight loss temperature of 300°C or higher, more preferably 320°C or higher, even more preferably 340°C or higher, and particularly preferably 360°C or higher, when heated at a rate of 10°C / min in a nitrogen atmosphere. In reality, the upper limit of the 5% thermal weight loss temperature in a nitrogen atmosphere is preferably 500°C or lower. If the hollow resin particles according to an embodiment of the present invention have a 5% thermal weight loss temperature within the above range when heated at a rate of 10°C / min in a nitrogen atmosphere, the hollow resin particles according to an embodiment of the present invention can exhibit excellent heat resistance. If the 5% thermal weight loss temperature of the hollow resin particles according to an embodiment of the present invention when heated at 10°C / min in a nitrogen atmosphere is too low and outside the above range, for example, when the hollow resin particles are kneaded with a thermosetting resin to form a resin composition, the particles may be deformed by heating for the curing reaction, and the hollow portion may be lost, which may result in a decrease in the dielectric properties that the hollow resin particles should exhibit in the resin composition, such as the effect of reducing the dielectric constant and the effect of reducing the dielectric tangent.

[0026] The hollow resin particles according to an embodiment of the present invention preferably have a 5% thermal weight loss temperature of 270°C or higher, more preferably 280°C or higher, even more preferably 290°C or higher, and particularly preferably 300°C or higher, when heated in an air atmosphere at a rate of 10°C / min. In practice, the upper limit of the 5% thermal weight loss temperature in an air atmosphere is preferably 500°C or lower. If the hollow resin particles according to an embodiment of the present invention have a 5% thermal weight loss temperature within the above range when heated in an air atmosphere at a rate of 10°C / min, the hollow resin particles according to an embodiment of the present invention can exhibit excellent heat resistance. If the 5% thermal weight loss temperature of the hollow resin particles according to an embodiment of the present invention when heated at 10°C / min in an air atmosphere is too low and outside the above range, for example, when the hollow resin particles are kneaded with a thermosetting resin, the particles will be deformed by heating for the curing reaction, and the hollow portion will be lost, which may result in a decrease in the dielectric properties that the hollow resin particles should exhibit in the resin composition, such as the effect of reducing the dielectric constant and the effect of reducing the dielectric tangent.

[0027] <1-2. Shell Portion> The shell portion includes a polymer (P) obtained by the reaction of a composition (A) containing, for example, a crosslinkable monomer (a) with at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by the following formula (2). The reaction is, for example, a polymerization reaction. The polymer (P) is preferably obtained by the polymerization reaction of a monomer component (M) containing the crosslinkable monomer (a) and the monofunctional monomer (b), or the polymerization reaction of the monomer component (M) and the compound (c). When the shell portion includes a polymer (P) having such a structure, the effects of the present invention can be more effectively exhibited.

[0028] The polymer (P) may be of one type only, or of two or more types.

[0029] The content of the polymer (P) 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 exhibit the effects of the present invention.

[0030] The shell portion may contain any appropriate other component as long as the effects of the present invention are not impaired. For example, the shell portion may contain a hydrocarbon-based resin (B). The hydrocarbon-based resin (B) may be one type or two or more types. When the shell portion contains the hydrocarbon-based resin (B), it becomes easier to construct a particle structure having a shell portion and a hollow portion surrounded by the shell portion. Furthermore, when the shell portion contains the hydrocarbon-based resin (B), the effects of the present invention can be more effectively exhibited. The shell portion may contain 0 to 10 parts by weight of the hydrocarbon-based resin (B) relative to 100 parts by weight of the total amount of the polymer (P) and the hydrocarbon-based resin (B). In order to further demonstrate the effects of the present invention, the proportion of the hydrocarbon-based resin (B) relative to 100 parts by weight of the total amount of the polymer (P) and the hydrocarbon-based resin (B) is preferably 1 to 10 parts by weight, more preferably 1 to 8 parts by weight, even more preferably 2 to 8 parts by weight, particularly preferably 2 to 6 parts by weight, and most preferably 2 to 5 parts by weight. Alternatively, the hydrocarbon-based resin (B) may be 1 to 5 parts by weight. When the proportion of the hydrocarbon-based resin (B) is within the above range, the effects of the present invention can be further demonstrated. This allows for the realization of hollow resin particles that have excellent dielectric properties that are not affected by the temperature environment and high heat resistance.

[0031] The shell portion may not contain the hydrocarbon resin (B).

[0032] The total content of the polymer (P) and the hydrocarbon-based resin (B) in the shell 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, still more preferably 90% by weight to 100% by weight, particularly preferably 95% by weight to 100% by weight, and most preferably 98% by weight to 100% by weight, in order to further exhibit the effects of the present invention.

[0033] Any appropriate compound can be used as the hydrocarbon resin (B) as long as it does not impair the effects of the present invention. Examples of the hydrocarbon resin (B) include aliphatic / aromatic hydrocarbon resins, aromatic hydrocarbon resins, alicyclic hydrocarbon resins, and aliphatic hydrocarbon resins. The hydrocarbon resin (B) 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. Based on the above, hollow resin particles having excellent dielectric properties unaffected by temperature environments can be realized, and hollow resin particles having excellent heat resistance can be realized. As a result, when the hollow resin particles are mixed with a resin such as a thermosetting resin to form a resin composition, the hollow resin particles are less likely to undergo substantial changes even when heated during molding or soldering of the thermosetting resin containing the hollow resin particles, thereby enabling the resin composition to better exhibit the dielectric properties expected of the resin composition. These hydrocarbon resins may be used alone or in combination of two or more.

[0034] The aliphatic / aromatic hydrocarbon resin refers to a hydrocarbon resin in which an aliphatic hydrocarbon and an aromatic hydrocarbon are copolymerized, such as a resin polymerized using styrene, vinyltoluene, indene, piperylene, or the like as a main raw material.

[0035] The aromatic hydrocarbon resin is a resin obtained by polymerizing, for example, styrene, vinyltoluene, indene, or the like as a main raw material.

[0036] The alicyclic hydrocarbon resin is, for example, a resin obtained by hydrogenating an aliphatic / aromatic hydrocarbon resin or an aromatic hydrocarbon resin.

[0037] The aliphatic hydrocarbon resin is a hydrocarbon resin obtained by polymerizing one or more aliphatic hydrocarbons having a polymerizable unsaturated bond.

[0038] The polymer (P) can be obtained, for example, by polymerizing a composition (A) containing a crosslinkable monomer (a) and at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by formula (2). That is, the polymer (P) has a structural unit derived from the crosslinkable monomer and at least one selected from the group consisting of a structural unit derived from the monofunctional monomer and an ether structure represented by formula (2).

[0039] The polymer (P) may preferably be a polymer obtained by polymerizing a monomer component (M) containing a crosslinkable monomer (a) and a monofunctional monomer (b), or may be a polymer obtained by polymerizing the monomer component (M) with the compound (c).

[0040] Examples of the crosslinkable monomer (a) include polyfunctional (meth)acrylic acid esters such as ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, and glycerin tri(meth)acrylate; polyfunctional acrylamide derivatives such as N,N'-methylenebis(meth)acrylamide and N,N'-ethylenebis(meth)acrylamide; polyfunctional allyl derivatives such as diallylamine and tetraallyloxyethane; and aromatic crosslinkable monomers such as divinylbenzene, divinylnaphthalene, diallyl phthalate, and divinylbiphenyl. In terms of being able to more effectively exhibit the effects of the present invention, aromatic crosslinkable monomers are preferred as the crosslinkable monomer (a), and divinylbenzene is more preferred. The crosslinkable monomer (a) may be of one type, or two or more types.

[0041] When composition (A) contains an aromatic crosslinkable monomer, the aromatic crosslinkable monomer is preferably present in an amount of 1 to 50 parts by weight, more preferably 1 to 40 parts by weight, even more preferably 1 to 35 parts by weight, particularly preferably 1 to 30 parts by weight, and most preferably 1 to 26 parts by weight, based on 100 parts by weight of the total amount of crosslinkable monomer (a), monofunctional monomer (b), and compound (c). The aromatic crosslinkable monomer is preferably present in an amount of 3 to 50 parts by weight, more preferably 5 to 50 parts by weight, even more preferably 8 to 40 parts by weight, particularly preferably 10 to 40 parts by weight, and most preferably 10 to 35 parts by weight. This allows for the realization of hollow resin particles with excellent dielectric properties that are not affected by high-temperature environments. If the content of the aromatic crosslinkable monomer is too high outside the above range, the dielectric properties of the hollow resin particles may deteriorate. If the content of the aromatic crosslinkable monomer is too small and outside the above range, the particles may aggregate during the production process, and a sufficient number of hollow resin particles may not be obtained.

[0042] Examples of the monofunctional monomer (b) include alkyl (meth)acrylates having 1 to 16 carbon atoms, such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, and cetyl (meth)acrylate; aromatic monofunctional monomers, such as styrene, α-methylstyrene, ethylvinylbenzene, vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, vinylbiphenyl, and vinylnaphthalene; dicarboxylic acid ester monomers, such as dimethyl maleate, diethyl fumarate, dimethyl fumarate, and diethyl fumarate; maleic anhydride; N-vinylcarbazole; and (meth)acrylonitrile. Aromatic monofunctional monomers are preferred as the monofunctional monomer (b) in that they can better exhibit the effects of the present invention. The monofunctional monomer (b) is preferably at least one selected from the group consisting of styrene, α-methylstyrene, ethylvinylbenzene, vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, vinylbiphenyl, vinylnaphthalene, and acenaphthylene, and more preferably styrene or ethylvinylbenzene. The monofunctional monomer (b) may be one type or two or more types.

[0043] When composition (A) contains an aromatic monofunctional monomer, the amount of the aromatic monofunctional monomer is preferably 10 to 99 parts by weight, more preferably 20 to 99 parts by weight, even more preferably 30 to 99 parts by weight, and particularly preferably 40 to 99 parts by weight, based on 100 parts by weight of the total amount of crosslinkable monomer (a), monofunctional monomer (b), and compound (c). The amount of the aromatic monofunctional monomer is preferably 20 to 95 parts by weight, more preferably 25 to 90 parts by weight, even more preferably 30 to 90 parts by weight, particularly preferably 35 to 85 parts by weight, and most preferably 40 to 85 parts by weight. This allows for the realization of hollow resin particles with excellent dielectric properties that are not affected by high-temperature environments.

[0044] The total content of the crosslinkable monomer (a) and the monofunctional monomer (b) in the monomer component (M) is, for example, 50% by weight to 100% by weight, and in terms of being able to further exhibit the effects of the present invention, 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, particularly preferably 90% by weight to 100% by weight, and most preferably 95% by weight to 100% by weight.

[0045] The content ratio of the crosslinkable monomer (a) relative to 100 parts by weight of the total amount of the crosslinkable monomer (a) and the monofunctional monomer (b) is preferably 5 to 85 parts by weight, more preferably 10 to 70 parts by weight, even more preferably 15 to 60 parts by weight, still more preferably 15 to 50 parts by weight, particularly preferably 20 to 45 parts by weight, and most preferably 20 to 40 parts by weight, in terms of being able to further exhibit the effects of the present invention.

[0046] The content ratio of the monofunctional monomer (b) relative to 100 parts by weight of the total amount of the crosslinkable monomer (a) and the monofunctional monomer (b) is preferably 15 to 95 parts by weight, more preferably 30 to 90 parts by weight, even more preferably 40 to 85 parts by weight, still more preferably 50 to 85 parts by weight, particularly preferably 55 to 80 parts by weight, and most preferably 60 to 80 parts by weight, in terms of being able to further exhibit the effects of the present invention.

[0047] The monomer component (M) may contain, in addition to the crosslinkable monomer (a) and the monofunctional monomer (b), another monomer (m). The other monomer (m) may be one type only, or two or more types.

[0048] As the other monomer (m), any appropriate monomer may be employed as long as it does not impair the effects of the present invention. As such other monomer (m), for example, a compound having at least one selected from the group consisting of a phosphate ester structure and a radical reactive group, preferably a compound having a phosphate ester structure and a radical reactive group, may be employed. In terms of being able to further exhibit the effects of the present invention, a compound having at least one selected from the group consisting of a phosphate ester structure and a radical reactive group is preferably a compound represented by formula (4).

[0049] In formula (4), R 1 , R 3 is a linear or branched alkylene group having 1 to 30 carbon atoms, and R 2 represents a methyl group or a hydrogen atom. In formula (4), m represents 1 to 300. In formula (4), n represents 1 to 3. In formula (4), a is 0 or 1, b is 0 to 300, and c is 0 or 1.

[0050] In formula (4), R 1 is preferably a linear or branched alkylene group having 1 to 20 carbon atoms, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms, even more preferably a linear or branched alkylene group having 1 to 8 carbon atoms, particularly preferably a linear or branched alkylene group having 1 to 6 carbon atoms, and most preferably a linear or branched alkylene group having 1 to 4 carbon atoms.

[0051] In formula (4), R 3 is preferably a linear or branched alkylene group having 1 to 20 carbon atoms, more preferably a linear or branched alkylene group having 1 to 10 carbon atoms, even more preferably a linear or branched alkylene group having 1 to 8 carbon atoms, particularly preferably a linear or branched alkylene group having 1 to 6 carbon atoms, and most preferably a linear or branched alkylene group having 1 to 4 carbon atoms.

[0052] In formula (4), m is preferably 1 to 100, more preferably 1 to 50, even more preferably 1 to 40, and particularly preferably 1 to 30.

[0053] In formula (4), b is preferably 0 to 100, more preferably 0 to 50, even more preferably 0 to 10, particularly preferably 0 to 5, and most preferably 0 or 1.

[0054] As the compound having at least one selected from the group consisting of a phosphate ester structure and a radical reactive group, a commercially available product may be used. From the viewpoint of compatibility, an example of the compound having at least one selected from the group consisting of a phosphate ester structure and a radical reactive group is the product name "KAYAMER (registered trademark) PM-21" (manufactured by Nippon Kayaku Co., Ltd.).

[0055] The content of the compound having at least one selected from the group consisting of a phosphate ester structure and a radical reactive group in the monomer component (M) is preferably 0 to 10% by weight, more preferably 0.01 to 5% by weight, even more preferably 0.05 to 3% by weight, and particularly preferably 0.1 to 1% by weight, in order to further exhibit the effects of the present invention.

[0056] As the compound (c), any appropriate compound may be used as long as it has the ether structure represented by the above formula (2) and a radical-reactive group, as long as it does not impair the effects of the present invention. In terms of further demonstrating the effects of the present invention, polyphenylene ether is a preferred example of such compound (c). Polyphenylene ether is a reactive polyphenylene ether that reacts with the above-mentioned monomer component (M) in the presence of a polymerization initiator, and is typically a modified polyphenylene ether having a polymerizable double bond at at least one end. The modified polyphenylene ether preferably has polymerizable double bonds at both ends, and more preferably is a low-molecular-weight modified oligomer based on polyphenylene ether and having bifunctional groups. Here, "having bifunctional groups" means that functional groups having double bonds or functional groups having substituents having double bonds are located at both ends of the oligomer. In terms of more easily producing hollow resin particles with excellent heat resistance, the number-average molecular weight Mn of the oligomer is preferably 500 to 3500.

[0057] A preferred example of such a modified polyphenylene ether is a compound represented by the following formula (5).

[0058] In formula (5), n1 and n2 each independently represent an integer of 0 to 300, provided that at least one of them is an integer of 1 or more; L 3 represents a divalent linking group. 3 is preferably selected from the group consisting of an alkylene group, an alkenylene group, -O-, -CO-, -CS-, -SO-, and -SO2-, more preferably an alkylene group, and even more preferably an isopropylidene group (-C(CH3)2-). Commercially available products of the compound represented by formula (5) include, for example, the "Noryl (registered trademark)" series (Noryl (registered trademark) SA9000, etc.) (manufactured by SABIC). As described above, the modified polyphenylene ether preferably has (meth)acryloyl groups at both ends. That is, compound (c) may be a polyphenylene ether having (meth)acryloyl groups at both ends.

[0059] Another preferred example of the modified polyphenylene ether is a compound represented by the following formula (6).

[0060] In formula (6), n1 and n2 each independently represent an integer of 0 to 300, provided that at least one of them is an integer of 1 or greater. Commercially available compounds represented by formula (6) include, for example, the trade name "OPE-2St" series (manufactured by Mitsubishi Gas Chemical Company, Inc.).

[0061] Other commercially available polyphenylene ether products include, for example, the trade name "Iupiace (registered trademark)" series (manufactured by Mitsubishi Chemical Corporation) and the trade name "Zylon (registered trademark)" series (manufactured by Asahi Kasei Corporation).

[0062] The reaction of the composition (A) can be carried out by any suitable reaction method as long as the effects of the present invention are not impaired. Such a reaction is, for example, a suspension polymerization reaction.

[0063] When carrying out a suspension polymerization reaction, typically, an oil phase is added to an aqueous phase and suspended to carry out the polymerization reaction. The aqueous phase or the oil phase may contain any appropriate solvent as long as the effects of the present invention are not impaired. Examples of such solvents include aqueous media and non-reactive solvents as described below. The solvent may be one type only, or two or more types.

[0064] The reaction of the composition (A) may be carried out in the presence of a hydrocarbon-based resin (B). For example, when carrying out the polymerization reaction of the composition (A) consisting of the crosslinkable monomer (a) and the monofunctional monomer (b), the hydrocarbon-based resin (B) may be used. The hydrocarbon-based resin (B) is as described above.

[0065] When reacting the composition (A), any suitable additive (C) that does not fall under any of the crosslinkable monomer (a), monofunctional monomer (b), compound (c), and hydrocarbon resin (B) may be used as long as it does not impair the effects of the present invention. The additive (C) may be one type or two or more types. The additive (C) here does not include solvents such as aqueous media and non-reactive solvents, or dispersion stabilizers, as described below.

[0066] The content of the additive (C) is preferably 0 to 40% by weight, more preferably 0 to 30% by weight, even more preferably 0 to 20% by weight, and particularly preferably 0 to 10% by weight, based on the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c).

[0067] Examples of the additive (C) include a non-crosslinkable polymer, a polymerization initiator, a surfactant, and a chain transfer agent.

[0068] By including a non-crosslinkable polymer as the additive (C), phase separation between the polymer (P) produced as the reaction proceeds and the solvent is promoted, and shell formation can be accelerated.

[0069] The non-crosslinkable polymer may be, for example, at least one selected from the group consisting of polyolefins, styrene-based polymers, (meth)acrylic acid-based polymers, and styrene-(meth)acrylic acid-based polymers.

[0070] Examples of polyolefins include polyethylene, polypropylene, poly-α-olefins, etc. From the viewpoint of solubility in the monomer component (M) and the compound (c), it is preferable to use a side-chain crystalline polyolefin using a long-chain α-olefin as a raw material, or a low-molecular-weight polyolefin or olefin oligomer produced using a metallocene catalyst.

[0071] Examples of styrene polymers include polystyrene, styrene-acrylonitrile copolymers, and acrylonitrile-butadiene-styrene copolymers.

[0072] Examples of the (meth)acrylic acid polymer include polymethyl(meth)acrylate, polyethyl(meth)acrylate, polybutyl(meth)acrylate, and polypropyl(meth)acrylate.

[0073] Examples of styrene-(meth)acrylic acid polymers include styrene-methyl(meth)acrylate copolymer, styrene-ethyl(meth)acrylate copolymer, styrene-butyl(meth)acrylate copolymer, and styrene-propyl(meth)acrylate copolymer.

[0074] In the suspension polymerization reaction, a surfactant may be used as the additive (C) from the viewpoint of more stably producing the desired hollow resin particles. As the surfactant, at least one selected from amphoteric surfactants and anionic surfactants is preferred, and it is more preferred to select at least an amphoteric surfactant, in order to more effectively exhibit the effects of the present invention. Specifically, it is preferred to add at least one selected from amphoteric surfactants and anionic surfactants to the aqueous phase containing the aqueous medium, and it is more preferred to add at least an amphoteric surfactant to the aqueous phase containing the aqueous medium (adding only an amphoteric surfactant, or adding both an amphoteric surfactant and an anionic surfactant).

[0075] As the amphoteric surfactant, any appropriate amphoteric surfactant can be used as long as it does not impair the effects of the present invention. As such an amphoteric surfactant, a known amphoteric surfactant that can be used in the production of resin particles can be used. Examples of amphoteric surfactants include lauryl dimethylamine oxide, lauryl dimethylaminoacetic acid betaine, phosphate surfactants, and phosphite surfactants. Only one type of amphoteric surfactant may be used, or two or more types may be used.

[0076] Any appropriate anionic surfactant can be used as the anionic surfactant as long as it does not impair the effects of the present invention. Examples of such anionic surfactants include fatty acid salts, polysulfonates, polycarboxylates, alkyl sulfate ester salts, alkylaryl sulfonates, alkylnaphthalenesulfonates, dialkylsulfonates, dialkylsulfosuccinates, alkyl phosphates, polyoxyethylene alkyl ether sulfates, polyoxyethylene alkylaryl ether sulfates, naphthalenesulfonate-formalin condensates, polyoxyethylene alkyl phosphate sulfonates, glycerol borate fatty acid esters, and polyoxyethylene glycerol fatty acid esters. Specific examples include sodium dodecylbenzenesulfonate, sodium lauryl sulfate, polyoxyethylene lauryl ether sodium sulfate, polyoxyethylene lauryl ether ammonium sulfate, polyoxyethylene nonylphenyl ether sulfate ester salts, and the sodium salt of β-naphthalenesulfonate-formalin condensates. The anionic surfactant may be used alone or in combination of two or more types.

[0077] The amount of the surfactant used is preferably within a range of 0.01 to 0.3 parts by weight, more preferably within a range of 0.02 to 0.2 parts by weight, relative to 100 parts by weight of the aqueous medium.

[0078] Examples of chain transfer agents include mercaptan compounds, styrene dimers, terpenes, halogenated hydrocarbons, and α-methylstyrene. Examples of mercaptan compounds include n-octyl mercaptan (1-octanethiol), n-dodecyl mercaptan (1-dodecanethiol), tert-dodecyl mercaptan, 2-hydroxyethyl mercaptan, n-octadecyl mercaptan (stearyl mercaptan), alkylenedithiols, and thiocyanuric acid, with n-octyl mercaptan and n-dodecyl mercaptan being preferred. Examples of styrene dimers include α-methylstyrene dimer. Examples of terpenes include γ-terpinene and dipentene. Examples of halogenated hydrocarbons include halogenated hydrocarbons. Among these chain transfer agents, mercaptan, α-methylstyrene, and styrene dimers are preferred, mercaptan and α-methylstyrene are more preferred, and mercaptan is even more preferred. These chain transfer agents may be used alone or in combination of two or more.

[0079] The amount of the chain transfer agent used is preferably 0.1 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, even more preferably 0.1 to 3 parts by weight, and particularly preferably 0.1 to 1 part by weight, when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is 100 parts by weight.

[0080] When reacting the composition (A), any suitable dispersion stabilizer (D) that does not fall under any of the crosslinkable monomer (a), the monofunctional monomer (b), the compound (c), and the hydrocarbon resin (B) may be used within a range that does not impair the effects of the present invention. The dispersion stabilizer (D) may be one type or two or more types.

[0081] The dispersion stabilizer (D) is preferably used in an amount of 0.5 to 10 parts by weight relative to 100 parts by weight of the aqueous medium. The dispersion stabilizer (D) may be used alone or in combination of two or more kinds.

[0082] Examples of the dispersion stabilizer (D) include inorganic water-soluble polymer compounds such as polyvinyl alcohol, polycarboxylic acid, celluloses (e.g., hydroxyethyl cellulose, carboxymethyl cellulose), polyvinylpyrrolidone, and sodium tripolyphosphate. Other examples of the dispersion stabilizer 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.

[0083] <1-3. Dielectric Constant and Dielectric Loss Tangent of Hollow Resin Particles> In electronic devices, which are one application of hollow resin particles, the transmission loss caused by radio waves transmitted for communication being converted into heat in a dielectric is expressed as the product of the square root of the frequency, the dielectric constant, and the dielectric loss tangent. In other words, since the transmission signal is more likely to be converted into heat in proportion to the frequency, the higher the frequency band, the lower the dielectric properties required of the materials used for communication components (semiconductor components) in order to suppress transmission loss.

[0084] Therefore, the dielectric constant of the hollow resin particles according to an embodiment of the present invention is preferably 1.0 to 2.5, more preferably 1.0 to 2.3, even more preferably 1.0 to 2.0, and particularly preferably 1.0 to 1.5, at a measurement frequency of 10 GHz. Herein, when simply referring to the "dielectric constant of the hollow resin particles," this refers to the dielectric constant of the hollow resin particles before a heating test. The dielectric constant before a heating test is the dielectric constant of the hollow resin particles under the conditions for measuring the dielectric loss tangent Df1 (i.e., the hollow resin particles in their initial state).

[0085] The dielectric loss tangent of the hollow resin particles according to an embodiment of the present invention is preferably 0 to 0.0016, more preferably 0 to 0.0015, even more preferably 0 to 0.0014, and particularly preferably 0 to 0.0013, at a measurement frequency of 10 GHz. Herein, when simply referring to the "dielectric loss tangent of the hollow resin particles," this refers to the dielectric loss tangent Df1 of the hollow resin particles before the heating test. When the relative dielectric constant and dielectric loss tangent of the hollow resin particles according to an embodiment of the present invention are within the above ranges, the effects of the present invention can be more effectively exhibited.

[0086] The hollow resin particles according to an embodiment of the present invention preferably have a relative dielectric constant of less than 2.0 and a dielectric loss tangent of less than 0.0017 at a measurement frequency of 10 GHz, and more preferably have a relative dielectric constant of less than 1.5 and a dielectric loss tangent of less than 0.0017 at a measurement frequency of 10 GHz.

[0087] When the dielectric constant of the hollow resin particles according to the embodiment of the present invention exceeds 2.0, even if the hollow resin particles are mixed with, for example, a thermosetting resin, a sufficient effect of lowering the dielectric constant cannot be obtained, and when used in a high frequency band, transmission loss occurs and the amount of heat generated by the component may increase. In particular, when the dielectric constant of the hollow resin particles exceeds 2.5, the above-mentioned problems are more likely to occur.

[0088] The hollow resin particles according to an embodiment of the present invention have a relative dielectric constant after a heating test under Condition I at 180°C for 1 hour at a measurement frequency of 10 GHz of preferably 1.0 to 2.5, more preferably 1.0 to 2.3, even more preferably 1.0 to 2.0, and particularly preferably 1.0 to 1.5.

[0089] The dielectric loss tangent Df2 of the hollow resin particles according to the embodiment of the present invention after the heating test under the above-mentioned condition I is preferably 0 to 0.005, more preferably 0 to 0.004, even more preferably 0 to 0.003, and particularly preferably 0 to 0.002 at a measurement frequency of 10 GHz. When the dielectric constant and dielectric loss tangent of the hollow resin particles according to the embodiment of the present invention after the heating test under the above-mentioned condition I are within the above-mentioned ranges, the effects of the present invention can be more effectively exhibited.

[0090] The hollow resin particles according to an embodiment of the present invention have a relative dielectric constant after a heating test under Condition II at 260°C for 10 minutes at a measurement frequency of 10 GHz of preferably 1.0 to 2.5, more preferably 1.0 to 2.3, and even more preferably 1.0 to 2.0.

[0091] The dielectric loss tangent Df3 of the hollow resin particles according to an embodiment of the present invention after the heating test under the above-mentioned condition II is preferably 0 to 0.010, more preferably 0 to 0.006, even more preferably 0 to 0.005, and particularly preferably 0 to 0.004 at a measurement frequency of 10 GHz. When the dielectric constant and dielectric loss tangent of the hollow resin particles according to an embodiment of the present invention after the heating test under the above-mentioned condition II are within the above-mentioned ranges, the effects of the present invention can be more effectively exhibited.

[0092] The values ​​of the dielectric constant and the dielectric loss tangent of the hollow resin particles according to the embodiment of the present invention are not limited to those described above. For example, when the hollow resin particles according to the embodiment of the present invention are used for applications other than semiconductor materials, the values ​​of the dielectric constant and the dielectric loss tangent are not limited to those described above.

[0093] <1-4. 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 the effects of the present invention can be more effectively utilized, the hollow resin particles according to an embodiment of the present invention are suitable for semiconductor components, and can be typically used in resin compositions for semiconductor components. In addition to the applications in the resin compositions for semiconductor components described above, the hollow resin particles according to an embodiment of the present invention can also be used in applications such as paint compositions, cosmetics, paper coating compositions, heat-insulating resin compositions, light-diffusing resin compositions, and light-diffusing films.

[0094] <Resin Composition for Semiconductor Member> The hollow resin particles according to an embodiment of the present invention can achieve a low dielectric constant and a low dielectric loss tangent and exhibit excellent heat resistance, and therefore can be suitably used in a resin composition for a semiconductor member.

[0095] 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.

[0096] 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.

[0097] A semiconductor package is constructed using an IC chip as an essential component and at least one member selected from a mold resin, an underfill material, a mold underfill material, a die bond material, a prepreg for a semiconductor package substrate, a metal-clad laminate for a semiconductor package substrate, and a build-up material for a printed circuit board for a semiconductor package.

[0098] A semiconductor module is constructed using a semiconductor package as an essential component and at least one member selected from a prepreg for printed circuit boards, a metal-clad laminate for printed circuit boards, a build-up material for printed circuit boards, a solder resist material, a coverlay film, an electromagnetic wave shielding film, and an adhesive sheet for printed circuit boards.

[0099] <Coating Composition> The hollow resin particles according to an embodiment of the present invention can impart an excellent appearance to a coating film containing the hollow resin particles, and therefore can be suitably used in a coating composition.

[0100] A coating composition according to an embodiment of the present invention includes hollow resin particles according to an embodiment of the present invention.

[0101] The coating composition according to an embodiment of the present invention preferably contains at least one selected from a binder resin and a UV-curable resin. The binder resin may be of only one type or may contain two or more types. The UV-curable resin may be of only one type or may contain two or more types.

[0102] Any suitable binder resin can be used as long as it does not impair the effects of the present invention. Examples of such binder resins include resins soluble in organic solvents or water, and emulsion-type aqueous resins that can be dispersed in water. Specific examples of binder resins include acrylic resins, alkyd resins, polyester resins, polyurethane resins, chlorinated polyolefin resins, and amorphous polyolefin resins.

[0103] As the UV-curable resin, any appropriate UV-curable resin can be used as long as it does not impair the effects of the present invention. Examples of such UV-curable resins include polyfunctional (meth)acrylate resins and polyfunctional urethane acrylate resins. Polyfunctional (meth)acrylate resins are preferred, and polyfunctional (meth)acrylate resins having three or more (meth)acryloyl groups in one molecule are more preferred. Specific examples of polyfunctional (meth)acrylate resins having three or more (meth)acryloyl groups in one molecule include trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate, 1,2,4-cyclohexane tetra(meth)acrylate, pentaglycerol triacrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexaacrylate.

[0104] When the coating composition according to an embodiment of the present invention contains at least one selected from a binder resin and a UV-curable resin, any appropriate content ratio can be adopted depending on the purpose. Typically, the hollow resin particles according to an embodiment of the present invention are preferably contained in an amount of 5 to 50% by weight, more preferably 10 to 50% by weight, and even more preferably 20 to 40% by weight of the total amount of the binder resin (in terms of solids content in the case of an emulsion-type aqueous resin), the at least one selected from the UV-curable resin, and the hollow resin particles according to an embodiment of the present invention.

[0105] When a UV-curable resin is used, a photopolymerization initiator is preferably used in combination. Any appropriate photopolymerization initiator can be used as long as it does not impair the effects of the present invention. Examples of such photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, α-hydroxyalkylphenones, α-aminoalkylphenones, anthraquinones, thioxanthones, azo compounds, peroxides (described in JP 2001-139663 A, etc.), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfonium compounds, onium salts, borate salts, active halogen compounds, and α-acyloxime esters.

[0106] The coating composition according to the embodiment of the present invention may contain a solvent. The solvent may be one kind or two or more kinds. When the coating composition according to the embodiment of the present invention contains a solvent, any appropriate content ratio can be adopted depending on the purpose.

[0107] As the solvent, any appropriate solvent can be used as long as it does not impair the effects of the present invention. Such a solvent is preferably a solvent that can dissolve or disperse a binder resin or a UV-curable resin. Examples of such solvents include, for oil-based paints, hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; and ether solvents such as dioxane, ethylene glycol diethyl ether, and ethylene glycol monobutyl ether. For water-based paints, examples of such solvents include water and alcohols.

[0108] The coating composition according to the embodiment of the present invention may be diluted to adjust the viscosity as needed. Any appropriate diluent may be used depending on the purpose. Examples of such diluents include the solvents mentioned above. The diluent may be one type or two or more types.

[0109] The coating composition according to an embodiment of the present invention may contain other components, such as a coating surface conditioner, a flowability conditioner, an ultraviolet absorber, a light stabilizer, a curing catalyst, an extender pigment, a color pigment, a metallic pigment, a mica powder pigment, or a dye, as needed.

[0110] When forming a coating film using the coating composition according to an embodiment of the present invention, any appropriate coating method can be adopted depending on the purpose, such as spray coating, roll coating, brush coating, coating reverse roll coating, gravure coating, die coating, comma coating, and spray coating.

[0111] When forming a coating film using the coating composition according to an embodiment of the present invention, any suitable method can be adopted depending on the purpose. For example, a coating film can be formed by applying the composition to any surface of a substrate, drying the coating film, and then curing the coating film as needed. Examples of substrates include metal, wood, glass, and plastics (PET (polyethylene terephthalate), PC (polycarbonate), acrylic resin, TAC (triacetyl cellulose), etc.).

[0112] The hollow resin particles according to an embodiment of the present invention can impart excellent heat insulating properties to a coating film containing the hollow resin particles, and therefore can be suitably used in a heat insulating resin composition. A coating film containing the hollow resin particles according to an embodiment of the present invention can exhibit excellent reflectance in the wavelength range from ultraviolet light to near-infrared light.

[0113] The heat insulating resin composition according to an embodiment of the present invention includes hollow resin particles according to an embodiment of the present invention.

[0114] The heat insulating resin composition according to an embodiment of the present invention preferably contains at least one selected from a binder resin and a UV-curable resin. The above-mentioned explanations regarding the coating composition can be applied to the binder resin and the UV-curable resin.

[0115] The heat insulating resin composition according to the embodiment of the present invention may contain a solvent. Regarding the solvent, the above explanation regarding the coating composition may be cited.

[0116] The heat insulating resin composition according to the embodiment of the present invention may be diluted to adjust the viscosity as needed. The above description of the coating composition can be used as the diluent.

[0117] The heat insulating resin composition according to an embodiment of the present invention may contain other components, such as a coating surface conditioner, a flowability conditioner, an ultraviolet absorber, a light stabilizer, a curing catalyst, an extender pigment, a color pigment, a metal pigment, a mica powder pigment, or a dye, as needed.

[0118] When a coating film is formed using the heat insulating resin composition according to an embodiment of the present invention, the coating method and formation method can be applied as described above for the coating composition.

[0119] <Light-diffusing resin composition> The hollow resin particles according to an embodiment of the present invention can impart excellent light-diffusing properties to a coating film containing the hollow resin particles, and therefore can be suitably used in a light-diffusing resin composition.

[0120] The light-diffusing resin composition according to an embodiment of the present invention includes hollow resin particles according to an embodiment of the present invention.

[0121] The light-diffusing resin composition according to an embodiment of the present invention preferably contains at least one selected from a binder resin and a UV-curable resin. The above-mentioned explanations regarding the coating composition can be applied to the binder resin and the UV-curable resin.

[0122] The light-diffusing resin composition according to the embodiment of the present invention may contain a solvent. Regarding the solvent, the above explanation regarding the coating composition may be cited.

[0123] The light-diffusing resin composition according to the embodiment of the present invention may be diluted to adjust the viscosity as needed. The above-mentioned description of the coating composition may be applied to the diluent.

[0124] The light-diffusing resin composition according to an embodiment of the present invention may contain other components, such as a coating surface conditioner, a flowability conditioner, an ultraviolet absorber, a light stabilizer, a curing catalyst, an extender pigment, a color pigment, a metal pigment, a mica powder pigment, or a dye, as needed.

[0125] When forming a coating film using the light-diffusing resin composition according to an embodiment of the present invention, the coating method and formation method can be applied as described above for the coating composition.

[0126] <Light Diffusion Film> The hollow resin particles according to an embodiment of the present invention can impart excellent light diffusibility to a film having a coating film containing the hollow resin particles, and therefore can also be suitably used in a light diffusing film.

[0127] The light diffusion film according to an embodiment of the present invention includes hollow resin particles according to an embodiment of the present invention.

[0128] The light diffusion film according to an embodiment of the present invention includes a light diffusion layer formed from the light-diffusing resin composition according to an embodiment of the present invention and a substrate. The light diffusion layer may or may not be the outermost layer of the light diffusion film. The light diffusion film according to an embodiment of the present invention may include any appropriate other layer depending on the purpose. Examples of such other layers include a protective layer, a hard coat layer, a planarizing layer, a high refractive index layer, an insulating layer, a conductive resin layer, a conductive metal fine particle layer, a conductive metal oxide fine particle layer, and a primer layer.

[0129] Examples of the substrate include metal, wood, glass, plastic film, plastic sheet, plastic lens, plastic panel, cathode ray tube, fluorescent display tube, and liquid crystal display panel. Examples of the plastic that constitutes the plastic film, plastic sheet, plastic lens, and plastic panel include polyethylene terephthalate (PET), polycarbonate (PC), acrylic resin, and triacetyl cellulose (TAC).

[0130] <<2. Method for Producing Hollow Resin Particles>> The method for producing hollow resin particles of the present invention involves reacting a composition (A) containing a crosslinkable monomer (a) and at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by the following formula (2) in an aqueous medium in the presence of a non-reactive solvent, wherein the amount of the crosslinkable monomer (a) is 1 to 50 parts by weight when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is 100 parts by weight:

[0131] According to the above-described manufacturing method, for example, hollow resin particles according to an embodiment of the present invention can be easily manufactured.

[0132] In the method for producing hollow resin particles of the present invention, the crosslinkable monomer (a) preferably includes an aromatic crosslinkable monomer. When the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is taken as 100 parts by weight, the amount of the aromatic crosslinkable monomer is preferably 1 to 50 parts by weight, more preferably 1 to 40 parts by weight, even more preferably 1 to 35 parts by weight, particularly preferably 1 to 30 parts by weight, and most preferably 1 to 26 parts by weight. Furthermore, the amount of the aromatic crosslinkable monomer is preferably 3 to 50 parts by weight, more preferably 5 to 50 parts by weight, even more preferably 8 to 40 parts by weight, particularly preferably 10 to 40 parts by weight, and most preferably 10 to 35 parts by weight.

[0133] The composition (A) may contain a monofunctional monomer (b) and a compound (c).

[0134] For example, hollow resin particles according to an embodiment of the present invention can be obtained by reacting a crosslinkable monomer (a) with at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) in an aqueous medium in the presence of a non-reactive solvent.Typically, hollow resin particles according to an embodiment of the present invention can be produced by subjecting a monomer component (M) containing the crosslinkable monomer (a) and the monofunctional monomer (b) to a suspension polymerization reaction, or by subjecting the monomer component (M) and the compound (c) to a suspension polymerization reaction.

[0135] The suspension polymerization is typically suspension polymerization using an aqueous phase containing an aqueous medium and an oil phase containing the composition (A) and a non-reactive solvent, and preferably, the oil phase containing the composition (A) and a non-reactive solvent is added to the aqueous phase containing an aqueous medium, dispersed, and heated to carry out suspension polymerization.

[0136] Any suitable dispersion method can be used for the dispersion, as long as it allows the oil phase to exist in the form of droplets in the aqueous phase, without impairing the effects of the present invention. Typical examples of such dispersion methods include dispersion methods using a homomixer or a homogenizer, such as a Polytron homogenizer, an ultrasonic homogenizer, or a high-pressure homogenizer.

[0137] The polymerization temperature may be any suitable temperature suitable for suspension polymerization as long as it does not impair the effects of the present invention. Such a polymerization temperature is preferably 30°C to 90°C.

[0138] The polymerization time may be any suitable 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 48 hours.

[0139] Post-heating, which is preferably carried out after polymerization, is a treatment suitable for obtaining hollow resin particles with a high degree of perfection.

[0140] 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 the temperature for such post-heating is preferably 70°C to 120°C.

[0141] The time for post-heating preferably carried out after polymerization can be any appropriate time within the range that does not impair the effects of the present invention, and the time for such post-heating is preferably 1 hour to 24 hours.

[0142] For the monomer component (M) and the compound (c), the explanation in the section <<1-2. Shell Portion>> of <<1. Hollow Resin Particles>> can be directly applied.

[0143] The monomer component (M) may contain, in addition to the crosslinkable monomer (a) and the monofunctional monomer (b), another monomer (m). The other monomer (m) may be one type or two or more types. The explanations in <<1-2. Shell Portion>> of <<1. Hollow Resin Particles>> may be used for the crosslinkable monomer (a), the monofunctional monomer (b), and the other monomer (m).

[0144] In order to further exert the effects of the present invention, the production method of the present invention may involve reacting the composition (A) in an aqueous medium in the presence of the hydrocarbon resin (B) and a non-reactive solvent, i.e., the oil phase may contain the hydrocarbon resin (B).

[0145] In order to further demonstrate the effects of the present invention, when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), the compound (c), and the hydrocarbon-based resin (B) is taken as 100 parts by weight, the amount of the hydrocarbon-based resin (B) is preferably 1 to 10 parts by weight, more preferably 1 to 8 parts by weight, even more preferably 2 to 8 parts by weight, particularly preferably 2 to 6 parts by weight, and most preferably 2 to 5 parts by weight. Alternatively, the amount of the hydrocarbon-based resin (B) may be 1 to 5 parts by weight. This allows for hollow resin particles with excellent dielectric properties that are not affected by high-temperature environments.

[0146] When the composition (A) contains the compound (c), the oil phase may not contain the hydrocarbon resin (B).

[0147] For the hydrocarbon resin (B), the explanation in the section <<1. Hollow Resin Particles>>, <<1-2. Shell Portion>> can be directly applied.

[0148] The non-reactive solvent is a solvent that does not chemically react with any of the monomer component (M), the compound (c), and the hydrocarbon-based resin (B), and is preferably an organic solvent. The non-reactive solvent typically acts as a hollowing agent that creates voids in the particles. Examples of non-reactive solvents include heptane, hexane, toluene, cyclohexane, methyl acetate, ethyl acetate, methyl ethyl ketone, chloroform, and carbon tetrachloride. The boiling point of the non-reactive solvent is preferably less than 100°C, as this facilitates removal from the hollow resin particles.

[0149] The non-reactive solvent used as the hollowing agent may be a single solvent or a mixed solvent.

[0150] The amount of the non-reactive solvent added is preferably 20 to 250 parts by weight per 100 parts by weight of the total amount of the monomer component (M) and the compound (c).

[0151] Examples of aqueous media include water and mixed media of water and lower alcohols (methanol, ethanol, etc.).

[0152] The amount of the aqueous medium used may be any appropriate amount as long as the effects of the present invention are not impaired. The amount of such an aqueous medium used is typically an amount that allows the suspension polymerization reaction to proceed appropriately in a suspension reaction carried out by adding an oil phase to an aqueous phase and suspending the oil phase, and is preferably 100 to 5,000 parts by weight, more preferably 150 to 2,000 parts by weight, relative to 100 parts by weight of the total amount of the monomer component (M), the compound (c), the hydrocarbon-based resin (B), and the non-reactive solvent.

[0153] When reacting the composition (A), any suitable additive (C) that does not fall under any of the monomer component (M), the compound (c), and the hydrocarbon resin (B) may be used as long as it does not impair the effects of the present invention. The additive (C) may be one type or two or more types. The additive (C) does not include solvents such as aqueous media and non-reactive solvents, and dispersion stabilizers.

[0154] The content of the additive (C) is preferably 0 to 40% by weight, more preferably 0 to 30% by weight, even more preferably 0 to 20% by weight, and particularly preferably 0 to 10% by weight, based on the total amount of the monomer component (M), the compound (c), and the hydrocarbon-based resin (B).

[0155] Examples of the additive (C) include a non-crosslinkable polymer, a polymerization initiator, and a surfactant.

[0156] For the non-crosslinked polymer, the explanation in the section <<1-2. Shell portion>> of <<1. Hollow resin particles>> can be directly applied.

[0157] Any appropriate polymerization initiator may be used as long as it does not impair the effects of the present invention. Examples of such polymerization initiators include organic peroxides such as lauroyl peroxide, benzoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxy-2-ethylhexanoate, and di-t-butyl peroxide; and azo compounds such as 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanecarbonitrile, and 2,2'-azobis(2,4-dimethylvaleronitrile).

[0158] The content of the polymerization initiator is preferably in the range of 0.1% by weight to 5% by weight based on the total amount of the monomer component (M) and the compound (c). The polymerization initiator may be of one kind or two or more kinds.

[0159] The polymerization initiator may be contained in the oil phase, the water phase, or may be used separately from the oil phase and the water phase. In one exemplary embodiment, the polymerization initiator is contained in the oil phase.

[0160] Regarding the surfactant, the explanation in the section <<1-2. Shell Portion>> of <<1. Hollow Resin Particles>> can be directly applied.

[0161] When the reaction of the composition (A) is carried out, any appropriate dispersion stabilizer (D) may be used within a range that does not impair the effects of the present invention.

[0162] The dispersion stabilizer may be contained in the oil phase, the water phase, or may be used separately from the oil phase and the water phase. In one exemplary embodiment, the dispersion stabilizer is contained in the water phase.

[0163] The amount of the dispersion stabilizer (D) is preferably 0.5 to 10 parts by weight per 100 parts by weight of the aqueous medium contained in the aqueous phase.

[0164] The dispersion stabilizer (D) may be used alone or in combination of two or more kinds.

[0165] As specific examples of the dispersion stabilizer (D), the explanation in the section <<1-2. Shell portion>> of <<1. Hollow resin particles>> can be directly cited.

[0166] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0167] <Measurement of Volume Average Particle Diameter and Coefficient of Variation of Particle Diameter (CV Value)> The volume average particle diameter of particles was measured by the Coulter method as follows. The volume average particle diameter of particles was measured using a Coulter Multisizer (registered trademark) 4e (a measuring device manufactured by Beckman Coulter, Inc.). The measurement was carried out using an aperture calibrated in accordance with the Multisizer 4e user's manual published by Beckman Coulter, Inc. The aperture used for the measurement was appropriately selected depending on the assumed volume average particle diameter of the particles to be measured. For example, when the assumed volume average particle diameter was 0.2 μm to 6 μm, an aperture having a size of 10 μm was selected; when the assumed volume average particle diameter was 1.0 μm to 32 μm, an aperture having a size of 50 μm was selected; and when the assumed volume average particle diameter was 2.0 μm to 60 μm, an aperture having a size of 100 μm was selected. If the volume average particle diameter after measurement differed from the expected volume average particle diameter, the aperture was changed to one with an appropriate size and the measurement was performed again. The measurement sample was prepared by dispersing 0.1 g of particles in 10 mL of a 0.1 wt % nonionic surfactant aqueous solution using a touch mixer (manufactured by Yamato Scientific Co., Ltd., "Touchmixer MT-31") and an ultrasonic cleaner (manufactured by Vervoclear 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 terminated when 100,000 particles had been measured. The volume average particle diameter of the particles was taken as the arithmetic mean of the particle size distribution based on the volume of 100,000 particles. The coefficient of variation (CV value) of the particle diameter of the particles was calculated using the following formula: Coefficient of variation of particle size (CV value) (%) of particles = (standard deviation of particle size distribution based on volume of particles ÷ volume average particle size of particles) × 100 (%)

[0168] <Measurement of 5% Thermal Weight Loss Temperature when Heating at 10°C / min in Air or Nitrogen Atmosphere> The 5% thermal weight loss temperature was measured using a thermogravimetric differential thermal analyzer ("NEXTA STA200RV" manufactured by Hitachi High-Tech Science Corporation). The sampling method and temperature conditions were as follows. 10.5±0.5 mg of sample was packed tightly into the bottom of a platinum measurement vessel to prepare a measurement sample. The 5% thermal weight loss temperature was measured using alumina as the reference material under an air or nitrogen gas flow rate of 200 mL / min. The TG / DTA curve was obtained by heating the sample from 30°C to 800°C at a heating rate of 10°C / min. The temperature at 5% weight loss was calculated from the obtained curve using the analysis software provided with the instrument, and was taken as the 5% thermal weight loss temperature.

[0169] <Observation of the Presence and Shape of Hollow Portions in Particles> The presence and shape of hollow portions in particles were observed by observing the cross section of the particles. The dried particles were mixed with a photocurable resin "D-800" (manufactured by JEOL Ltd.) and irradiated with ultraviolet light to obtain a cured product. The cured product was then cut with nippers, the cross section was smoothed using a cutter, and the sample was coated using a sputtering device (manufactured by JEOL Ltd., "Auto Fine Coater JFC-1300"). Next, the cross section of the sample was photographed using a secondary electron detector of a scanning electron microscope (manufactured by Hitachi High-Technologies Corporation, "SU1510"). At this time, the image was taken at a magnification of 3000x, 4000x, or 5000x.

[0170] <Dielectric Properties of Hollow Resin Particles Before Heating Test> The dielectric properties of the hollow resin particles were measured using a dielectric constant measuring device (ADMS01Nc series) manufactured by AET Corporation. The measurement was performed at a frequency of 10 GHz under the conditions of 23°C and a relative humidity of 51±1%. Based on perturbation theory using a resonator, the relative permittivity and dielectric loss tangent (Df1) of the hollow resin particles before the heating test were calculated.

[0171] <Dielectric Properties of Hollow Resin Particles After Heating Test Under Condition I> First, a heating test under Condition I was performed by leaving a predetermined amount of particles for 1 hour in a constant-humidity oven tank whose internal temperature was adjusted to 180° C. After the heating test, the particles were allowed to cool, and then the dielectric properties were measured under the same conditions and by the same method as in the above <Dielectric Properties of Hollow Resin Particles Before Heating Test>, and the relative dielectric constant and the dielectric loss tangent (Df2) of the hollow resin particles after the heating test under Condition I were calculated.

[0172] <Dielectric Properties of Hollow Resin Particles After Heating Test Under Condition II> First, a heating test was performed by leaving a predetermined amount of particles for 2 minutes in a constant-humidity oven tank whose internal temperature was adjusted to 260° C. After the heating test, the particles were allowed to cool, and then the dielectric properties were measured under the same conditions and by the same method as in the above <Dielectric Properties of Hollow Resin Particles Before Heating Test>, and the relative dielectric constant and the dielectric loss tangent (Df3) of the hollow resin particles after the heating test under Condition II were calculated.

[0173] Example 1 An oil phase was prepared by mixing 87.1 g of styrene (manufactured by Denka Company Limited), 39.0 g of divinylbenzene (DVB) 810 (Nippon Steel Chemical & Material Co., Ltd., 81% content, 19% being ethylvinylbenzene (EVB)), 130 g of heptane, 3.9 g of Petrotack 90 (aliphatic / aromatic hydrocarbon resin, manufactured by Tosoh Corporation), 2.6 g of 2,2′-azobis(2,4-dimethylvaleronitrile) (ADVN, trade name “V-65”, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 0.52 g of “KAYAMER (registered trademark) PM-21” (manufactured by Nippon Kayaku Co., Ltd.) as another monomer. The oil phase was added to 1,111 g of a 2.0 wt % aqueous dispersion of magnesium pyrophosphate as the aqueous phase, and the mixture was dispersed at 7,000 rpm for 5 minutes using a Polytron homogenizer (Central Scientific Trading Co., Ltd., "PT10-35"), followed by emulsification at a processing pressure of 20 MPa using a high-pressure emulsifier (Yoshida Kikai Kogyo Co., Ltd., "NVL-AS200") to produce a suspension. The resulting suspension was heated at 65°C for 5 hours to polymerize, and then heated at 80°C for 3 hours as a residual reaction treatment to complete the polymerization reaction and obtain a slurry. Hydrochloric acid was added to the resulting slurry to decompose the magnesium pyrophosphate, and the solids were separated by dehydration through filtration, purified by repeated water washing, and then heated and dried to obtain particles (1) as a dry powder. The resulting particles (1) had a volume average particle size of 4.1 μm and a coefficient of variation (CV value) of 32.2%. A cross-sectional photograph of the resulting particles (1) is shown in FIG. 2. The obtained particles (1) were confirmed to be hollow resin particles having a porous structure with the hollow space surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0174] Example 2 Particles (2) were obtained in the same manner as in Example 1, except that the blending amount of styrene (manufactured by Denka Company Ltd.) was 74.1 g and the blending amount of divinylbenzene (DVB) 810 (Nippon Steel Chemical & Material Co., Ltd., 81% content, 19% ethylvinylbenzene (EVB)) was 52.0 g. The volume average particle diameter of the obtained particles (2) was 4.4 μm, and the coefficient of variation (CV value) was 24.6%. A cross-sectional photograph of the obtained particles (2) is shown in FIG. 3. It was confirmed that the obtained particles (2) were hollow resin particles with a porous structure surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0175] Example 3 An oil phase was prepared by mixing 39.0 g of a reactive low-molecular-weight polyphenylene ether (trade name "Noryl (registered trademark) SA9000-111 resin", manufactured by SABIC) as a compound having an ether structure, 52.0 g of styrene (manufactured by Denka Company Limited), 39.0 g of divinylbenzene (DVB) 810 (Nippon Steel Chemical & Material Co., Ltd., 81% content, 19% is ethylvinylbenzene (EVB)), 1.3 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN, trade name "V-65", manufactured by Fujifilm Wako Pure Chemical Industries Co., Ltd.) as a polymerization initiator, 0.52 g of "KAYAMER (registered trademark) PM-21" (manufactured by Nippon Kayaku Co., Ltd.) as another monomer, and 0.65 g of a chain transfer agent, octyl mercaptan (1-octanethiol, manufactured by Tokyo Chemical Industry Co., Ltd.) as an additive. The oil phase was added to 1,111 g of a 2.0 wt % aqueous dispersion of magnesium pyrophosphate as the aqueous phase, and the mixture was dispersed at 7,000 rpm for 5 minutes using a Polytron homogenizer (Central Scientific Trading Co., Ltd., "PT10-35"), followed by emulsification at a processing pressure of 20 MPa using a high-pressure emulsifier (Yoshida Kikai Kogyo Co., Ltd., "NVL-AS200") to produce a suspension. The resulting suspension was heated at 60°C for 5 hours, and then stirred at 90°C for an additional 2 hours to complete the polymerization reaction, yielding a slurry. Hydrochloric acid was added to the resulting slurry to decompose the magnesium pyrophosphate, and the solids were separated by dehydration through filtration, purified by repeated water washing, and then heated and dried to obtain particles (3) as a dry powder. The resulting particles (3) had a volume average particle size of 4.4 μm and a coefficient of variation (CV value) of 34.1%. A cross-sectional photograph of the resulting particles (3) is shown in FIG. 4. The obtained particles (3) were confirmed to be hollow resin particles having a porous structure with the hollow space surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0176] Example 4 Particles (4) were obtained in the same manner as in Example 1, except that the blending amount of styrene (manufactured by Denka Company Ltd.) was 52.0 g, the blending amount of divinylbenzene (DVB) 810 (Nippon Steel Chemical & Material Co., Ltd., 81% content, 19% ethylvinylbenzene (EVB)) was 78.0 g, and Petrotack 90 (aliphatic / aromatic hydrocarbon resin, manufactured by Tosoh Corporation) was not used. The volume average particle diameter of the obtained particles (4) was 3.9 μm, and the coefficient of variation (CV value) was 28.9%. A cross-sectional photograph of the obtained particles (4) is shown in FIG. 5. It was confirmed that the obtained particles (4) were hollow resin particles with a porous structure surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0177] Example 5: Instead of 3.9 g of Petrotack 90 (aliphatic / aromatic hydrocarbon resin, manufactured by Tosoh Corporation), VYBAR TM Particles (5) were obtained in the same manner as in Example 1, except that 3.9 g of 260 (paraffin wax, manufactured by Nucera Solutions) was used. The volume average particle diameter of the obtained particles (5) was 4.0 μm, and the coefficient of variation (CV value) was 27.5%. A cross-sectional photograph of the obtained particles (5) is shown in FIG. 6. It was confirmed that the obtained particles (5) were hollow resin particles having a porous structure surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0178] Example 6 An oil phase was prepared in the same manner as in Example 5. The oil phase was added to 1,111 g of a 2.0 wt % aqueous dispersion of magnesium pyrophosphate as the aqueous phase, and the oil phase was emulsified for 5 minutes at 7,000 rpm using a Polytron homogenizer (Central Scientific Trading Co., Ltd., "PT10-35") to prepare a suspension. The resulting suspension was heated at 65°C for 5 hours to polymerize, and then heated at 80°C for 2 hours to complete the polymerization reaction, yielding a slurry. Hydrochloric acid was added to the resulting slurry to decompose the magnesium pyrophosphate, and the solids were separated by filtration and dehydrated. Purification was carried out by repeated water washing, followed by heat drying to obtain particles (6) as a dry powder. The resulting particles (6) had a volume average particle size of 9.1 μm and a coefficient of variation of 42.5%. A cross-sectional photograph of the resulting particles (6) is shown in Figure 7. The resulting particles (6) were confirmed to be hollow resin particles with a porous structure surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0179] Example 7 An oil phase was prepared in the same manner as in Example 3. The oil phase was added to 1,111 g of a 2.0 wt % aqueous dispersion of magnesium pyrophosphate as the aqueous phase, and the oil phase was emulsified for 5 minutes at 7,000 rpm using a Polytron homogenizer (Central Scientific Trading Co., Ltd., "PT10-35") to prepare a suspension. The resulting suspension was heated at 60°C for 5 hours to polymerize, and then heated at 80°C for 2 hours to complete the polymerization reaction, yielding a slurry. Hydrochloric acid was added to the resulting slurry to decompose the magnesium pyrophosphate, and the solids were separated by filtration and dehydrated. Purification was carried out by repeated water washing, followed by heat drying to obtain particles (7) as a dry powder. The resulting particles (7) had a volume average particle size of 11.3 μm and a coefficient of variation of 40.4%. A cross-sectional photograph of the resulting particles (7) is shown in Figure 8. The resulting particles (7) were confirmed to be hollow resin particles with a porous structure surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0180] Comparative Example 1 65.0 g of methyl methacrylate, 65.0 g of ethylene glycol dimethacrylate, 130 g of cyclohexane, 1.3 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN, trade name "V-65", manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) as a polymerization initiator, and 0.52 g of "KAYAMER (registered trademark) PM-21" (manufactured by Nippon Kayaku Co., Ltd.) as another monomer were mixed to prepare an oil phase. The oil phase was added to 1111 g of a 2.0 wt% aqueous dispersion of magnesium pyrophosphate as the aqueous phase, and the mixture was dispersed and emulsified at 7,000 rpm for 5 minutes using a Polytron homogenizer (manufactured by Central Scientific Trading Co., Ltd., "PT10-35") to prepare a suspension. The resulting suspension was heated at 55°C for 5 hours to polymerize, and then heated at 80°C for 2 hours as a residual reaction treatment to complete the polymerization reaction and obtain a slurry. Hydrochloric acid was added to the resulting slurry to decompose the magnesium pyrophosphate, and the solids were separated by dehydration through filtration. Purification was carried out by repeated washing with water, followed by heat drying to obtain particles (C1) as a dry powder. The resulting particles (C1) had a volume average particle size of 7.6 μm and a coefficient of variation (CV value) of 26.8%. A cross-sectional photograph of the resulting particles (C1) is shown in FIG. 9. The resulting particles (C1) were confirmed to be hollow resin particles with a porous structure surrounded by a shell. The blending amounts and various measurement results are shown in Table 1.

[0181] Comparative Example 2 Particles (C2) were obtained in the same manner as in Example 1, except that styrene (manufactured by Denka Company Limited) was not used and the amount of divinylbenzene (DVB) 810 (Nippon Steel Chemical & Material Co., Ltd., 81% content, 19% ethylvinylbenzene (EVB)) blended was 130.0 g. The volume average particle diameter of the obtained particles (C2) was 4.3 μm, and the coefficient of variation (CV value) was 28.9%. A cross-sectional photograph of the obtained particles (C2) is shown in FIG. 10. It was confirmed that the obtained particles (C2) were hollow resin particles with a porous structure surrounded by a shell. The blend amounts and various measurement results are shown in Table 1.

[0182]

[0183] From the results in Table 1, it can be seen that the particles obtained in Examples 1 to 7 were hollow resin particles that were not affected by high-temperature environments and had excellent dielectric properties.

[0184] <Performance Evaluation: Evaluation of Relative Dielectric Constant and Dielectric Loss Tangent of Particle-Added Films> A film containing particles (1) obtained in Example 1, a film containing particles (3) obtained in Example 3, and a film containing particles (C1) obtained in Comparative Example 1 were prepared as follows, and the relative dielectric constant and dielectric loss tangent of the films were evaluated. 0.425 g of the obtained particles, 8.3 g of ethyl acetate, and 1.7 g of solvent-soluble polyimide KPI-MX300F (manufactured by Kawamura Sangyo Co., Ltd.) were degassed and stirred using a planetary stirring defoamer (manufactured by KURABO Corporation, "Mazerustar KK-250") to prepare a mixture for evaluation. The mixture for evaluation was applied to a 5 mm-thick glass plate using an applicator set to a wet thickness of 250 μm, and then heated at 60°C for 30 minutes, 90°C for 10 minutes, 150°C for 30 minutes, and 200°C for 30 minutes to remove ethyl acetate. Films containing each particle were then obtained by cooling to room temperature. The dielectric constant and dielectric loss tangent of the obtained film were evaluated by a cavity resonance method (measurement frequency: 10 GHz). The measurement results were expressed as a relative percentage (%), with the measurement value of a film containing no particles being 100%. The results are shown in Table 2.

[0185]

[0186] From the results in Table 2, it can be confirmed that the hollow resin particles provided by the present invention have the effect of further reducing the relative dielectric constant and dielectric loss tangent of the substrate compared to the particles (C1) of Comparative Example 1, and are therefore effective for the purpose of lowering the dielectric constant and dielectric loss tangent of semiconductor materials.

[0187] 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 used as semiconductor materials and the like.

Claims

1. Hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion, wherein when a heating test under condition I is conducted at 180°C for 1 hour, a dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and a dielectric loss tangent Df2 at a measurement frequency of 10 GHz after the heating test under condition I satisfy formula (1): Df2-Df1≦0.004 ... (1).

2. The hollow resin particle according to claim 1, wherein the dielectric loss tangent Df1 is less than 0.

002.

3. The hollow resin particle according to claim 1, having a relative dielectric constant of less than 1.5 at a measurement frequency of 10 GHz.

4. The hollow resin particle according to claim 1, wherein the shell portion comprises a polymer (P) obtained by reacting a composition (A) containing a crosslinkable monomer (a) and at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by formula (2).

5. The hollow resin particle according to claim 4, wherein the crosslinkable monomer (a) is an aromatic crosslinkable monomer.

6. The hollow resin particles according to claim 5, wherein the aromatic crosslinkable monomer is 1 part by weight to 50 parts by weight when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is 100 parts by weight.

7. The hollow resin particles according to claim 4, wherein the monofunctional monomer (b) is at least one selected from the group consisting of styrene, α-methylstyrene, ethylvinylbenzene, vinyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, vinylbiphenyl, vinylnaphthalene, and acenaphthylene.

8. The hollow resin particle according to claim 4, wherein the shell portion contains 0 to 10 parts by weight of the hydrocarbon resin (B) per 100 parts by weight of the total amount of the polymer (P) and the hydrocarbon resin (B).

9. The hollow resin particles according to claim 1, which have a 5% thermal weight loss temperature of 270° C. or higher when the hollow resin particles are heated at a rate of 10° C. / min in an air atmosphere.

10. The hollow resin particles according to claim 1, having a volume average particle size of 0.1 μm to 30 μm.

11. Hollow resin particles having a shell portion and a hollow portion surrounded by the shell portion, wherein when a heating test under condition II is conducted at 260°C for 2 minutes, a dielectric loss tangent Df1 at a measurement frequency of 10 GHz before the heating test and a dielectric loss tangent Df3 at a measurement frequency of 10 GHz after the heating test under condition II satisfy formula (3): Df3-Df1≦0.004 ... (3).

12. The hollow resin particle according to claim 11, wherein the dielectric loss tangent Df1 is less than 0.

002.

13. The hollow resin particles according to any one of claims 1 to 12, which are used in a resin composition for semiconductor members.

14. A resin composition for semiconductor members, comprising the hollow resin particles according to claim 13.

15. A method for producing hollow resin particles, comprising reacting a composition (A) containing a crosslinkable monomer (a) and at least one selected from the group consisting of a monofunctional monomer (b) and a compound (c) having an ether structure represented by formula (2) in an aqueous medium in the presence of a non-reactive solvent, wherein the amount of the crosslinkable monomer (a) is 1 to 50 parts by weight when the total amount of the crosslinkable monomer (a), the monofunctional monomer (b), and the compound (c) is 100 parts by weight.

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