Curable composition, electronic component device, high-frequency device, dielectric substrate, and microstrip antenna

Abstract

Disclosed is a curable composition which contains: a curable component that is radically polymerizable and contains an ethylenically unsaturated double bond; and an inorganic filler that is at least one substance which is selected from the group consisting of titanium oxide, calcium titanate and strontium titanate.

Description

Curable composition, electronic component device, high frequency device, dielectric substrate and microstrip antenna

[0001] The present disclosure relates to a curable composition, an electronic component device, a high-frequency device, a dielectric substrate, and a microstrip antenna.

[0002] In recent years, with the demand for electronic devices to be more highly functional and lighter, thinner, shorter, and smaller, the integration and even higher density of electronic components have progressed, and the semiconductor packages used in these electronic devices have become smaller than ever before.Furthermore, the radio waves used for communication in electronic devices have become higher in frequency.

[0003] In order to reduce the size of semiconductor packages and to accommodate high frequencies, high-dielectric-constant resin compositions for use in encapsulating semiconductor elements have been proposed (see, for example, Patent Documents 1 to 3). Furthermore, molding resin compositions that exhibit both a high dielectric constant and a low dielectric loss tangent in a cured product after molding have also been proposed (see, for example, Patent Document 4).

[0004] JP 2015-036410 A JP 2017-057268 A JP 2018-141052 A WO 2022 / 123792

[0005] In recent years, in order to accommodate the increasing number of channels accompanying the diversification of information, the radio waves used for communication in electronic devices equipped with semiconductor devices have become higher in frequency. As radio waves become higher in frequency, there is a demand for encapsulating resin compositions with low dielectric loss tangents. When materials with high dielectric loss tangents are used, the transmission signal is converted into heat due to dielectric loss, which tends to reduce communication efficiency. The amount of dielectric loss generated when radio waves transmitted for communication are converted into heat in a dielectric is expressed as the product of the frequency, the square root of the relative dielectric constant, and the dielectric loss tangent. The transmission signal is more likely to be converted into heat in proportion to the frequency. Therefore, to reduce dielectric loss in high-frequency radio waves, it is desirable to reduce the dielectric loss tangent. For example, the molding resin composition of Patent Document 4 can be molded into a cured product exhibiting a low dielectric loss tangent. However, considering changes in applications and molding methods, it is desirable to be able to mold cured products exhibiting low dielectric loss tangents from other molding resin compositions as well.

[0006] An object of one aspect of the present disclosure is to provide a curable composition capable of forming a cured product exhibiting a low dielectric loss tangent, and an electronic component device, a high-frequency device, a dielectric substrate, and a microstrip antenna using the same.An object of another aspect of the present disclosure is to provide a curable composition having excellent flowability and usable for injection molding, and an electronic component device using the same.

[0007] The present disclosure includes the following embodiments. <1> A curable composition comprising: a curable component having an ethylenically unsaturated double bond and capable of radical polymerization; and an inorganic filler that is at least one selected from the group consisting of titanium oxide, calcium titanate, and strontium titanate. <2> A curable composition for injection molding comprising: a curable component having an ethylenically unsaturated double bond and capable of radical polymerization; and an inorganic filler. <3> The curable composition according to <1> or <2>, wherein the curable component includes at least one compound selected from the group consisting of compounds having a vinylphenyl group and compounds having a maleimide group. <4> The curable composition according to any one of <1> to <3>, wherein the curable component includes a compound having a vinylphenyl group that is liquid at 25°C and a compound having a maleimide group that is solid at 25°C. <5> The curable composition according to any one of <1> to <4>, wherein the curable component contains a compound having a vinylphenyl group and a compound having a maleimide group, and the molar ratio of the maleimide group to the vinylphenyl group (maleimide group / vinylphenyl group) is 0.05 to 5.0. <6> The curable composition according to any one of <1> to <5>, which is solid at 25°C. <7> The curable composition according to any one of <1> to <6>, wherein the curable component contains a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a compound represented by the following formula (b1):

[0008]

[0009] (In the formula, X ｂ１represents an organic group, each B independently represents a group containing a vinylphenyl group, and 1 represents an integer of 1 to 5. <8> The curable composition according to any one of <1> to <7>, wherein the curable component contains a compound having a vinylphenyl group, and the compound having a vinylphenyl group contains a compound having two or more vinylphenyl groups. <9> The curable composition according to any one of <1> to <8>, wherein the curable component contains a compound having a vinylphenyl group, and the compound having a vinylphenyl group contains a compound represented by the following formula (b3):

[0010]

[0011] (In the formula, B ｈｂ each independently represents a hydrogen atom or a group represented by the following formula (Bz), and at least one B ｈｂ is a group represented by the following formula (Bz).

[0012]

[0013] (wherein * represents a bonding position.) <10> The curable composition according to any one of <1> to <9>, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a polymer having a vinylphenyl group. <11> The curable composition according to any one of <1> to <10>, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a polymer having a structural unit represented by the following formula (Bb):

[0014]

[0015] (wherein X represents an organic group, B represents each independently a group containing a vinylphenyl group, R represents each independently a substituent, l represents an integer of 1 to 5, m represents an integer of 0 to 10, and * represents a bonding position to another atom.) <12> The curable composition according to any one of <1> to <11>, wherein the curable component contains a compound having a vinylphenyl group, and the compound having a vinylphenyl group contains at least one selected from the group consisting of a polymer represented by the following formula (B3-3) and a polymer represented by the following formula (B3-7):

[0016]

[0017] (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5. The benzene ring may each independently have a substituent at a substitutable position.

[0018]

[0019] (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5. The benzene ring may each independently have a substituent at a substitutable position.

[0020]

[0021] (wherein * represents a bonding position.) <13> The curable composition according to any one of <1> to <12>, wherein the curable component includes a compound having a vinylbenzyl group, and the compound having a vinylbenzyl group includes a compound represented by the following formula (A):

[0022]

[0023] (Wherein, R １ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position to another structure, and a plurality of R １ At least one of R is a vinylbenzyl group; ４ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position to another structure, and R ｘ１ and R ｘ２are each independently a divalent aliphatic hydrocarbon group or a single bond, Ar is a substituted or unsubstituted biphenylene group or a substituted or unsubstituted phenylene group, and n is an integer of 1 or greater.) <14> The curable composition according to any one of <1> to <13>, wherein the cured product has a dielectric dissipation factor of 0.010 or less when cured at 175°C for 6 hours. <15> The curable composition according to any one of <1> to <14>, which is used to form a part of a high-frequency device. <16> An electronic component device comprising an electronic component and a cured product of the curable composition according to any one of <1> to <15>, which seals at least a part of the electronic component. <17> A high-frequency device comprising a cured product of the curable composition according to any one of <1> to <15>. <18> A dielectric substrate obtained by curing the curable composition according to any one of <1> to <15>. <19> A microstrip antenna comprising: the dielectric substrate according to <18>; a radiating element provided on one surface of the dielectric substrate; and a ground conductor plate provided on the other surface of the dielectric substrate.

[0024] According to one aspect of the present disclosure, there are provided a curable composition capable of forming a cured product exhibiting a low dielectric loss tangent, and an electronic component device, a high-frequency device, a dielectric substrate, and a microstrip antenna using the same. According to another aspect of the present disclosure, there are provided a curable composition having excellent flowability and usable for injection molding, and an electronic component device using the same.

[0025] FIG. 1 is a schematic diagram illustrating an example of a method for manufacturing an electronic component device using an injection molding machine.

[0026] Embodiments of the present disclosure will be described. The present disclosure is not limited to the following embodiments. The following embodiments can be implemented alone or in combination. Combinations of multiple embodiments are also included in the present disclosure.

[0027] In the present disclosure, a numerical range indicated using "to" means a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in the present disclosure, the upper or lower limit of a certain numerical range may be replaced with the upper or lower limit of another numerical range. The upper or lower limit of a numerical range described in the present disclosure may be replaced with a value shown in the Examples. A stepped numerical range may be created by selecting a numerical value from the upper and lower limit numerical values ​​described in stages in the present disclosure. The upper and lower limit numerical values ​​described in the present disclosure may be replaced with a value shown in the Examples. In the present disclosure, each component may contain multiple corresponding substances. When multiple substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified. In the present disclosure, each structure in the polymer may contain multiple corresponding structures. When a polymer contains multiple structures corresponding to each structure, the content or amount of each structure refers to the total content or amount of the multiple structures present in the polymer, unless otherwise specified. In the present disclosure, the particles corresponding to each component may contain multiple types of particles. When a composition contains multiple types of particles corresponding to each component, the particle size of each component refers to the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified. The curable composition of the present disclosure is a concept that encompasses the curable composition according to the first embodiment and the cured product composition according to the second embodiment described below.

[0028] <Curable Composition> [First Embodiment] The curable composition according to a first embodiment of the present disclosure is a composition including a curable component that contains an ethylenically unsaturated double bond and is radically polymerizable (hereinafter also referred to as a specific curable component), and an inorganic filler that is at least one selected from the group consisting of titanium oxide, calcium titanate, and strontium titanate (hereinafter also referred to as a specific inorganic filler).

[0029] The curable composition according to the first embodiment contains a specific curable component and a specific inorganic filler. This allows for the formation of a cured product exhibiting a low dielectric loss tangent. The curable composition of the present disclosure is used in various molding methods, such as injection molding, transfer molding, and compression molding. For example, the curable composition of the present disclosure may be used in injection molding. By using the specific curable component, the curable composition tends to have a lower viscosity during injection molding than when a thermoplastic resin is used, which tends to enable injection molding at low pressures.

[0030] [Second embodiment] A curable composition according to a second embodiment of the present disclosure is a composition including an ethylenically unsaturated double bond and a radically polymerizable curable component, and an inorganic filler, and the composition is used for injection molding.

[0031] The curable composition according to the second embodiment includes a specific curable component and an inorganic filler. The use of the specific curable component provides excellent flowability, and the curable composition tends to have a lower viscosity during injection molding than when a thermoplastic resin is used, which tends to enable injection molding at a low pressure.

[0032] For example, in conventionally widely used epoxy resin compositions, the curing reaction causes the ring opening of epoxy groups to generate hydroxyl groups. Because hydroxyl groups are polar groups, the dielectric dissipation factor of the cured product increases. In contrast, certain curable components tend not to generate polar groups such as hydroxyl groups when cured, thereby keeping the dielectric dissipation factor of the cured product low. Therefore, the curable composition of the present disclosure can be suitably applied to high-frequency devices that require a low dielectric dissipation factor.

[0033] The curable composition of the present disclosure may be liquid at 25° C. or solid at 25° C. From the viewpoint of handling such as transportation and mixing, it may be solid at 25° C. The liquid state may be in a range that can be measured with a viscometer.

[0034] The specific curable component contained in the curable composition is a component that contains an ethylenically unsaturated double bond and is radically polymerizable. Examples of the specific curable component include a compound having an acrylic group, a compound having a methacrylic group, a compound having a vinyl group, and a compound having a maleimide group. One type of the specific curable component may be used alone, or two or more types may be used in combination.

[0035] The specific curable component preferably contains at least one compound selected from the group consisting of a compound having a vinylphenyl group (hereinafter also referred to as a "vinylphenyl compound") and a compound having a maleimide group (hereinafter also referred to as a "maleimide compound"), which tends to reduce molding shrinkage when a cured product of the curable composition is produced.

[0036] The specific curable component preferably contains a vinylphenyl compound and a maleimide compound, and more preferably contains a vinylphenyl compound that is liquid at 25° C. and a maleimide compound that is solid at 25° C. Because the vinylphenyl compound and the maleimide compound have excellent reactivity, it is possible to keep the heating temperature lower than when a cured product is obtained by polymerizing only the vinylphenyl compound. Furthermore, it is also possible to keep the heating temperature for curing lower than in conventional general epoxy resin compositions with the curable composition of the present disclosure.

[0037] [Compound Having a Vinylphenyl Group] The vinylphenyl compound is a compound having at least one vinylphenyl group. The vinylphenyl compound has, for example, 1 to 20, 1 to 15, or 1 to 10 vinylphenyl groups. The vinylphenyl compound may be used alone or in combination of two or more types.

[0038] The vinylphenyl group can be represented by any of the following formulas: From the viewpoint of obtaining a cured product with a low dielectric constant and dielectric loss tangent, the vinylphenyl compound preferably contains a compound having a group represented by formula (p): * indicates the bonding position to other atoms.

[0039] The proportion of groups represented by formula (p) relative to the total amount of groups represented by formula (p), groups represented by formula (m), and groups represented by formula (o) in the total amount of the vinylphenyl compound is preferably 40 mol% or more, may be 50 mol% or more, may be 60 mol% or more, or may be 70 mol% or more. Moreover, the proportion of groups represented by formula (p) may be 10 mol% or more, may be 20 mol% or more, or may be 30 mol% or more. The greater the proportion of groups represented by formula (p), the lower the dielectric constant and dielectric loss tangent of the cured product tend to be.

[0040] In the total amount of vinylphenyl compounds contained in the curable composition, the molar ratio of groups represented by formula (p), groups represented by formula (m), and groups represented by formula (o) (groups represented by formula (p): groups represented by formula (m): groups represented by formula (o)) is, for example, 40 to 100: 0 to 60: 0 to 60, 70 to 90: 0: 10 to 30, or 40 to 60: 40 to 60: 0.

[0041] The vinylphenyl compound may be a compound having a vinylphenylmethyl group (also referred to as a "vinylbenzyl group"). In the present disclosure, a compound having a vinylbenzyl group may be referred to as a "vinylbenzyl compound". A vinylbenzyl compound is an example of a vinylphenyl compound. The vinylphenyl compound may be a compound having a vinylphenylmethyloxy group (also referred to as a "vinylbenzyl ether group"). In the present disclosure, a compound having a vinylbenzyl ether group may be referred to as a "vinylbenzyl ether compound". A vinylbenzyl ether compound is an example of a vinylbenzyl compound and a vinylphenyl compound.

[0042] The vinylphenyl compound may further have an aromatic ring in addition to the vinylphenyl group. The vinylphenyl compound may have only one aromatic ring or two or more aromatic rings. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring. The aromatic ring may be a monocyclic ring or a condensed polycyclic ring. Examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, tetracene, fluorene, phenanthrene, indene, indane, and biphenylene. Examples of aromatic heterocyclic rings include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, and benzothiophene. From the viewpoint of the dielectric properties of the cured product, the aromatic ring may be an aromatic hydrocarbon ring or a condensed polycyclic aromatic hydrocarbon ring. In terms of dielectric constant and dielectric loss tangent, examples of aromatic rings include fluorene and indene, and indene is preferred. When the vinylphenyl compound contains indene, a cured product exhibiting a lower dielectric constant and dielectric loss tangent tends to be obtained.

[0043] In some embodiments, the vinyl phenyl compound includes a compound having two or more vinyl phenyl groups. The compound having two or more vinyl phenyl groups may be a monomer or a polymer.

[0044] The vinylphenyl compound may be a monomer or polymer capable of radical polymerization. The vinylphenyl compound includes, for example, a monomer having a vinylphenyl group. In the present disclosure, a monomer having a vinylphenyl group may be referred to as a "vinylphenyl group-containing monomer." The vinylphenyl compound includes, for example, a polymer having a vinylphenyl group. In the present disclosure, a polymer having a vinylphenyl group may be referred to as a "vinylphenyl group-containing polymer." In the present disclosure, the monomer may be a compound that does not contain a repeating structural unit. The polymer may be a compound that contains a repeating structural unit. The polymer may be a polymer with a low degree of polymerization (i.e., an oligomer) or a polymer with a high degree of polymerization.

[0045] Examples of the vinylphenyl compound include compounds represented by the following formula (b1).

[0046]

[0047] In formula (b1), X ｂ１ represents an organic group, B each independently represents a group containing a vinylphenyl group, and l represents an integer of 1 to 5. "Independently each" means that when l is 2 or more and there are multiple Bs, the multiple Bs may be the same "group containing a vinylphenyl group", or some or all of the Bs may be different "groups containing a vinylphenyl group". "Independently each" does not preclude l from being 1, and the structural unit represented by formula (b1) may have one "group containing a vinylphenyl group". The same applies to "independently each" in the present disclosure.

[0048] X ｂ１ The organic group represented by formula (b1) may be a group containing at least one carbon atom. When the compound represented by formula (b1) is a vinylphenyl group-containing monomer, X ｂ１Examples of the organic group represented by formula (b1) include aromatic ring groups. Examples of the aromatic ring contained in the aromatic ring group are as described above. When the compound represented by formula (b1) is a vinylphenyl group-containing monomer, l may be 1 to 3. When the compound represented by formula (b1) is a vinylphenyl group-containing polymer, X ｂ１ The organic group represented by is a polymer.

[0049] (Vinylphenyl Group-Containing Monomer) In some embodiments, the vinylphenyl compound includes a vinylphenyl group-containing monomer. In some embodiments, the vinylphenyl group-containing monomer includes a monomer having two vinylphenyl groups and may further include at least one selected from the group consisting of a monomer having one vinylphenyl group and a monomer having three vinylphenyl groups; or may include a monomer having two vinylphenyl groups, a monomer having one vinylphenyl group, and a monomer having three vinylphenyl groups. When the vinylphenyl group-containing monomer includes two or more vinylphenyl group-containing monomers, the average number of vinylphenyl groups in the vinylphenyl group-containing monomer is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6.

[0050] The vinylphenyl group-containing monomer may further have an aromatic ring other than the benzene ring contained in the vinylphenyl group. The vinylphenyl group-containing monomer may have only one aromatic ring or may have two or more aromatic rings. Examples of aromatic rings are as described above.

[0051] The vinylphenyl group-containing monomer may include, for example, a monomer having one aromatic ring other than the benzene ring contained in the vinylphenyl group and 1 to 3 vinylphenyl groups bonded to the aromatic ring directly or via a linking group; a monomer having one aromatic hydrocarbon and 1 to 3 vinylphenyl groups bonded to the aromatic hydrocarbon directly or via a linking group; or a monomer having one indene ring and 1 to 3 vinylphenyl groups bonded to the indene ring directly or via a linking group. The linking group may be, for example, a group selected from the group consisting of an alkylene group having 1 to 5 carbon atoms, an oxy group, a thio group, a sulfonyl group, a sulfinyl group, a carbonyl group, a carbonyloxy group, an imino group, and a group formed by combining two or more selected from these. Note that "having one aromatic ring and 1 to 3 vinylphenyl groups bonded to the aromatic ring via a linking group" means "having one aromatic ring and 1 to 3 linking groups bonded to the aromatic ring and 1 to 3 vinylphenyl groups bonded to the linking group."

[0052] The vinylphenyl group-containing monomer may have a saturated or unsaturated aliphatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a group containing a hetero atom, or the like in place of or in addition to the aromatic ring.

[0053] The weight average molecular weight (Mw) of the vinylphenyl group-containing monomer is, for example, 200 to 2,000, 200 to 1,000, 200 to 800, 250 to 750, or 300 to 700 from the viewpoint of curability and handleability. In the present disclosure, the weight average molecular weight (Mw) and number average molecular weight (Mn) refer to values ​​measured in polystyrene equivalent by gel permeation chromatography (GPC). Specifically, the weight average molecular weight (Mw) in the present disclosure can be measured by the method described in the Examples. The number average molecular weight (Mn) in the present disclosure can be measured in the same manner as the Mw measurement method described in the Examples.

[0054] When the vinylphenyl group-containing monomer contains a compound represented by formula (b1), it may contain a compound in which l is 2 in formula (b1) and may further contain at least one compound selected from the group consisting of a compound in which l is 1 and a compound in which l is 3; or it may contain a compound in which l is 2, a compound in which l is 1, and a compound in which l is 3. When the vinylphenyl group-containing monomer contains multiple types of compounds represented by formula (b1), the average value of l in the compounds represented by formula (b1) is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6.

[0055] In some embodiments, the vinyl phenyl compound includes a compound represented by the following formula (b2): When the vinyl phenyl compound includes a compound represented by the following formula (b2), better heat resistance and a lower coefficient of linear thermal expansion tend to be obtained.

[0056]

[0057] In formula (b2), X ｂ２ represents an aromatic hydrocarbon group; B ｐ each independently represents a group represented by the following formula (Ph); each L independently represents a direct bond or a linking group; and 1 represents an integer of 1 to 3.

[0058] In formula (Ph), * represents a bonding position.

[0059] Examples of the aromatic hydrocarbon ring contained in the aromatic hydrocarbon ring group are as described above. ｂ２may be, for example, a fused polycyclic aromatic hydrocarbon ring group. Examples of the linking group are as described above. The linking group may be, for example, an alkylene group or a methylene group. The vinylphenyl group-containing monomer may, for example, contain a compound in which l is 2 in formula (b2), and may further contain at least one compound selected from the group consisting of a compound in which l is 1 and a compound in which l is 3; or may contain a compound in which l is 2, a compound in which l is 1, and a compound in which l is 3. When the vinylphenyl group-containing monomer contains multiple types of compounds represented by formula (b2), the average value of l in the compounds represented by formula (b2) is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6. Note that L being a "direct bond" means that X ｂ２ and B ｐ The same applies to "direct bond" in the present disclosure.

[0060] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Ph) may include a group represented by formula (p) above.

[0061] In some embodiments, the vinyl phenyl compound includes a compound represented by the following formula (b3): ​​When the vinyl phenyl compound includes a compound represented by the following formula (b3), better heat resistance and a lower coefficient of linear thermal expansion are obtained, and further, a low dielectric constant and a low dielectric loss tangent tend to be obtained.

[0062]

[0063] In formula (b3), B ｈｂ each independently represents a hydrogen atom or a group represented by the following formula (Bz), and at least one B ｈｂ is a group represented by the following formula (Bz).

[0064] In formula (Bz), * represents a bonding position.

[0065] The vinylphenyl group-containing monomer includes a compound in which, in formula (b3), the number of groups represented by formula (Bz) is 2, and may further include at least one selected from the group consisting of compounds in which the number of groups represented by formula (Bz) is 1 and compounds in which the number of groups represented by formula (Bz) is 3; or may include a compound in which the number of groups represented by formula (Bz) is 2, a compound in which the number is 1, and a compound in which the number is 3. When the vinylphenyl group-containing monomer includes multiple types of compounds represented by formula (b3), the average number of groups represented by formula (Bz) in the compounds represented by formula (b3) is, for example, 1.4 to 2.8, 1.6 to 2.7, or 1.8 to 2.6.

[0066] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Bz) may include a group in which the bonding position of the vinyl group to the benzene ring is para to the bonding position of the methylene group to the benzene ring.

[0067] The method for synthesizing the vinylphenyl group-containing monomer is not particularly limited. For example, when the vinylphenyl group-containing monomer is a compound represented by formula (b2), a method of reacting an aromatic hydrocarbon with a styrene having a halogenated methyl group in the presence of a basic compound can be mentioned. When synthesized by this method, the compound represented by formula (b2) has a methylene group as a linking group.

[0068] Examples of styrenes having a halogenated methyl group include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene, and these can be used alone or in combination of two or more. Examples of basic compounds include alkali metal hydroxides and alkali metal alkoxides. A phase transfer catalyst may be used in this reaction. Examples of phase transfer catalysts include tetrabutylphosphonium bromide and tetra-n-butylammonium bromide. The reaction can be carried out in a solvent. The reaction may be carried out under heating and stirring. A polymerization inhibitor may be added to the reaction system. The resulting product may be purified, as necessary, by known methods such as concentration, reprecipitation, and washing.

[0069] (Vinylphenyl Group-Containing Polymer) In some embodiments, the vinylphenyl compound includes a vinylphenyl group-containing polymer. The vinylphenyl compound may include a polymer having two vinylphenyl groups; or a polymer having three or more vinylphenyl groups. Examples of the vinylphenyl group-containing polymer include a polymer having a hydrocarbon chain skeleton and a vinylphenyl group; a polymer having a phenolic resin skeleton and a vinylphenyl group, and the like. Examples of polymers having a hydrocarbon chain skeleton include polyolefins, vinyl-based polymers, acrylic polymers, polydicyclopentadiene, and the like. Examples of phenolic resins include novolac-type phenolic resins, aralkyl-type phenolic resins, dicyclopentadiene-type phenolic resins, triphenylmethane-type phenolic resins, and resins containing a naphthol structure instead of or in addition to the phenol structure in these phenolic resins.

[0070] From the viewpoint of handleability, the weight average molecular weight (Mw) of the vinylphenyl group-containing polymer is, for example, 300 to 50,000, 500 to 30,000, 1,000 to 10,000, or more than 2,000 to 10,000. From the viewpoint of improving the fluidity of the curable composition, the weight average molecular weight (Mw) may be 5,000 or less, or 2,500 or less.

[0071] In some embodiments, the vinyl phenyl compound may include a polymer including a structure represented by formula (Bb):

[0072]

[0073] In formula (Bb), X represents an organic group, each B independently represents a group containing a vinylphenyl group, each R independently represents a substituent, l represents an integer of 1 to 5, and m represents an integer of 0 to 10. * represents the bonding position to another atom.

[0074] The organic group represented by X may be a group containing at least one carbon atom, and may be, for example, a group containing at least one selected from the group consisting of saturated aliphatic hydrocarbon groups, unsaturated aliphatic hydrocarbon groups, saturated alicyclic hydrocarbon groups, unsaturated alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and aromatic heterocyclic groups. The organic group represented by X may further contain a linking group containing a heteroatom, a substituent containing a heteroatom, or the like. Examples of the substituent represented by R include alkyl groups having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. m represents, for example, an integer of 0 to 5, an integer of 0 to 2, or 0.

[0075] In some embodiments, the vinyl phenyl compound comprises a polymer comprising a structure represented by formula (B1):

[0076]

[0077] In formula (B1), X Ｂ１ represents an organic group, B represents a group containing a vinylphenyl group, R each independently represents a substituent, and m represents an integer of 0 to 10. * represents the bonding position to other atoms. X Ｂ１ has the same meaning as X in formula (Bb). Also, B, R, and m in formula (B1) have the same meaning as B, R, and m in formula (Bb), respectively.

[0078] In some embodiments, the vinyl phenyl compound includes a polymer represented by the following formula (B2): When the vinyl phenyl compound includes a polymer represented by the following formula (B2), better heat resistance and a lower coefficient of linear thermal expansion tend to be obtained.

[0079]

[0080] In formula (B2), X Ｂ２ each independently represents a benzene ring or a naphthalene ring; each Y independently represents an organic group; B ｐeach independently represent a group represented by the following formula (Ph); each L independently represents a direct bond or a linking group; each R independently represents a substituent; each m independently represents an integer of 0 to 5; and n represents a number of 2 to 10.

[0081] In formula (Ph), * represents a bonding position.

[0082] The organic group represented by Y may be a group containing at least one carbon atom, and examples thereof include substituted or unsubstituted alkylene groups such as a methylene group or an ethylene group; substituted or unsubstituted cycloalkylene groups such as tetrahydrodicyclopentadiene; substituted or unsubstituted arylalkylene groups such as a phenylmethylene group; and substituted or unsubstituted divalent organic groups containing an alkylene group and an arylene group.

[0083] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Ph) may include a group represented by formula (p) above.

[0084] Examples of the linking group represented by L include an alkylene group, an oxy group, a thio group, a sulfonyl group, a sulfinyl group, a carbonyl group, a carbonyloxy group, an imino group, and a group formed by combining two or more selected from these.

[0085] Examples of the substituent represented by R include alkyl groups having 1 to 5 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl. The substituent may be an alkyl group having 1 to 5 carbon atoms, or a methyl group. Each m independently represents, for example, an integer of 0 to 4, an integer of 0 to 2, or 0.

[0086] n is an average value in the polymer represented by formula (B2), and n is, for example, a number from 2 to 8, or a number from 3 to 5.

[0087] In some embodiments, the vinyl phenyl compound may comprise at least one selected from the group consisting of polymers represented by the formula:

[0088]

[0089]

[0090] In each of the above formulas, B ｐ each independently represent a group represented by the above formula (Ph), each L independently represents a direct bond or a linking group, and n represents a number of 2 to 10. The benzene ring and the naphthalene ring may each independently have a substituent at a substitutable position.

[0091] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Ph) may include a group represented by formula (p) above.

[0092] Examples of the linking group represented by L in each formula include an alkylene group, an oxy group, a thio group, a sulfonyl group, a sulfinyl group, a carbonyl group, a carbonyloxy group, an imino group, and a group formed by combining two or more selected from these. The linking group may contain an oxy group from the viewpoint of obtaining good tracking resistance. The linking group may contain, for example, a methyleneoxy group, and in this case, the polymer represented by the above formula may contain B ｐ -CH ２ The structure includes a structure represented by —O—* (* represents the bonding position to another atom).

[0093] When the benzene ring and naphthalene ring in each formula have a substituent, examples of the substituent include an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, and an n-pentyl group. The substituent may be an alkyl group having 1 to 5 carbon atoms, or may be a methyl group. Alternatively, the benzene ring and naphthalene ring in each formula are unsubstituted, or may be a group represented by the formula *-L-B ｐ (* indicates the bonding position to another atom) and may have no other substituents.

[0094] n is an average value in the polymer represented by each formula, and n is, for example, a number from 2 to 8, or a number from 3 to 5.

[0095] When the vinylphenyl compound contains at least one selected from the group consisting of polymers represented by formulas (B2-1) to (B2-11), excellent heat resistance and a low coefficient of linear thermal expansion tend to be readily obtained. When the vinylphenyl compound contains at least one selected from the group consisting of polymers represented by formulas (B2-3) and (B2-7), a low dielectric constant and dielectric dissipation factor tend to be readily obtained. In particular, when the vinylphenyl compound contains a polymer represented by formula (B2-3), an even lower dielectric constant and dielectric dissipation factor tend to be readily obtained. In particular, when the vinylphenyl compound contains a polymer represented by formula (B2-7), good tracking resistance tends to be readily obtained, and the curable composition tends to exhibit good fluidity.

[0096] In some embodiments, the vinylphenyl compound includes at least one selected from the group consisting of a polymer represented by the following formula (B3-3) and a polymer represented by the following formula (B3-7):

[0097]

[0098] In formula (B3-3), B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5.

[0099]

[0100] In formula (B3-7), B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5.

[0101] In formula (Bz), * represents a bonding position.

[0102] From the viewpoint of obtaining a cured product having a low dielectric constant and a low dielectric loss tangent, the group represented by formula (Bz) may include a group in which the bonding position of the vinyl group to the benzene ring is para to the bonding position of the methylene group to the benzene ring.

[0103] The method for synthesizing the vinylphenyl group-containing polymer is not particularly limited. For example, when the vinylphenyl group-containing polymer is a compound represented by formula (B2-1), a method of reacting a phenol resin with a styrene having a halogenated methyl group in the presence of a basic compound can be mentioned. When synthesized by this method, the compound represented by formula (B2-1) has a methyleneoxy group as a linking group.

[0104] Examples of the styrene having a halogenated methyl group, the basic compound, and the phase transfer catalyst are as described above. The reaction can be carried out in a solvent. The reaction can be carried out under heating and stirring. A polymerization inhibitor can be added to the reaction system. The resulting product can be purified, if necessary, by known methods such as concentration, reprecipitation, and washing.

[0105] Examples of phenolic resins include novolac-type phenolic resins, aralkyl-type phenolic resins, dicyclopentadiene-type phenolic resins, biphenyl-type phenolic resins, triphenylmethane-type phenolic resins, and resins containing a naphthol structure instead of or in addition to the phenol structure in these phenolic resins. Commercially available phenolic resins can be used.

[0106] The weight average molecular weight (Mw) of the phenolic resin is, for example, 300 to 30,000, 500 to 10,000, or 1,000 to 5,000 from the viewpoint of handleability of the curable composition. The number average molecular weight (Mn) of the phenolic resin is, for example, 200 to 10,000, 500 to 5,000, or 1,000 to 2,000 from the viewpoint of handleability. The hydroxyl equivalent of the phenolic resin is, for example, 50 to 500 g / eq, 100 to 400 g / eq, or 150 to 300 g / eq from the viewpoint of the heat resistance and linear thermal expansion coefficient of the cured product. The hydroxyl equivalent can be measured by a method in accordance with JIS K 0070:1992.

[0107] The vinylbenzyl compound may include a compound represented by the following formula (A):

[0108]

[0109] In formula (A), R１ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position to another structure, and a plurality of R １ At least one of R is a vinylbenzyl group; ４ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position to another structure, and R ｘ１ and R ｘ２ are each independently a divalent aliphatic hydrocarbon group or a single bond, Ar is a substituted or unsubstituted biphenylene group or a substituted or unsubstituted phenylene group, and n is an integer of 1 or greater.

[0110] In formula (A), R １ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position with another bond, and a plurality of R １ At least one of R is a vinylbenzyl group. １ The monovalent organic group represented by the formula (I) is preferably a saturated or unsaturated, chain or cyclic hydrocarbon group. １ At least one of the remaining R １ The monovalent organic group represented by R may have 1 to 30, 1 to 12, or 1 to 4 carbon atoms. １ The monovalent organic group represented by R may specifically be an alkyl group, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, or a sec-butyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. １ The bonding site represented by the formula (A) may be a bonding site with a unit having a biphenyl group, a bonding site with a unit having a vinylbenzyl group, etc. １ In formula (A), multiple R １ At least one of R is a vinylbenzyl group, and the remaining R １ is preferably a hydrogen atom in part or in whole.

[0111] In formula (A), R ４are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position with another bond. That is, R ４ are each independently R １ In formula (A), a plurality of R ４ may be all the same or some or all may be different. ４ is preferably a monovalent organic group or a hydrogen atom, more preferably an alkyl group having 1 to 30, 1 to 12, or 1 to 4 carbon atoms or a hydrogen atom, and even more preferably a hydrogen atom. ４ may all be hydrogen atoms. ４ A part or all of the groups may be groups that do not contain an ethylenic double bond.

[0112] In formula (A), R ｘ１ and R ｘ２ are each independently a divalent aliphatic hydrocarbon group or a single bond. The divalent aliphatic hydrocarbon group may be a saturated or unsaturated, chain or alicyclic hydrocarbon group, preferably a saturated chain hydrocarbon group, and specifically may be an alkyl group. The number of carbon atoms in the divalent aliphatic hydrocarbon group may be, for example, 1 to 30, 1 to 20, or 1 to 10, and from the viewpoint of dielectric properties, may be 1 to 8, 1 to 6, or 1 to 4. Examples include a methylene group, an ethylene group, a trimethylene group, an isopropylene group, an n-butylene group, an isobutylene group, a tert-butylene group, and a sec-butylene group. In formula (A), R ｘ１ and R ｘ２ may be the same or different. ｘ１ and R ｘ２ are each preferably independently a methylene group or a single bond, more preferably a methylene group.

[0113] In formula (A), Ar is a substituted or unsubstituted biphenylene group, or a substituted or unsubstituted phenylene group. When the biphenylene group and the phenylene group have a substituent, the substituent may be a monovalent organic group, a halogen atom, or the like. The monovalent organic group may be an alkyl group, and may be an alkyl group having 1 to 30, 1 to 12, or 1 to 4 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a sec-butyl group, or the like. The biphenylene group and the phenylene group may contain a functional group containing a heteroatom as a substituent, but from the viewpoint of dielectric properties, it is preferable that they do not contain a functional group containing a heteroatom.

[0114] In formula (A), n is an integer of 1 or more. n is an integer of preferably 1 to 10, more preferably 1 to 5, and still more preferably 1 to 4. n may be 1. Furthermore, in general formula (1), n ​​may be an integer appropriately determined depending on the weight average molecular weight (Mw) of the vinylbenzyl compound, which will be described later.

[0115] The vinylbenzyl compound is not limited by its synthesis method, and can be obtained, for example, by reacting substituted or unsubstituted indene, a substituted or unsubstituted compound having one or two phenylene groups, and a substituted or unsubstituted vinylbenzyl halide. Examples of the substituent include monovalent organic groups such as alkyl groups having 1 to 30, 1 to 12, or 1 to 4 carbon atoms, halogen atoms, and hydrogen atoms.

[0116] In formula (A), the bonding site between the indene ring and the vinylbenzyl group is preferably the 1-position of the indene ring. ｘ１ and R ｘ２ The bonding site is preferably the 1st or 2nd position of the indene ring. The vinylbenzyl group may be any of an o-vinylbenzyl group, an m-vinylbenzyl group, and a p-vinylbenzyl group, but a p-vinylbenzyl group is more preferred. In formula (A), it is preferred that some or all of the vinylbenzyl groups are p-vinylbenzyl groups.

[0117] In formula (A), a compound having a structure in which at least one vinylbenzyl group is bonded to each indene ring is preferred. For example, it is a compound represented by the following formula (A-1). In formula (A-1), the details of each functional group and n are the same as those in formula (A) above, so explanation will be omitted. In formula (A-1), R １ and R ４ is more preferably an alkyl group having 1 to 30, 1 to 12, or 1 to 4 carbon atoms or a hydrogen atom, and even more preferably a hydrogen atom. １ and R ４ may all be hydrogen atoms.

[0118]

[0119] For example, the vinylbenzyl compound may include a compound represented by the following formula (1):

[0120]

[0121] In formula (1), R １ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position with another bond, and a plurality of R １ At least one of R is a vinylbenzyl group; ４ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position with another bond, and R ｘ１ and R ｘ２ are each independently a divalent aliphatic hydrocarbon group or a single bond, and Ar is a substituted or unsubstituted biphenylene group or a substituted or unsubstituted phenylene group.

[0122] The details of each functional group are the same as those in formula (A) above, and therefore will not be described here.

[0123] An example of such a compound is the compound represented by the following formula (1-1): In formula (1-1), the details of each functional group are the same as those in formula (A) above, and therefore will not be described here. １ and R ４is more preferably an alkyl group having 1 to 30, 1 to 12, or 1 to 4 carbon atoms or a hydrogen atom, and even more preferably a hydrogen atom. １ and R ４ may all be hydrogen atoms.

[0124]

[0125] The vinylbenzyl compound may include a compound represented by the following formula (2):

[0126]

[0127] In formula (2), R １ are each independently a monovalent organic group, a halogen atom, or a hydrogen atom, and R ４ are each independently a monovalent organic group, a halogen atom, or a hydrogen atom, and R ５ and R ６ are each independently a divalent aliphatic hydrocarbon group or a single bond, and R ７ and R ８ are each independently a monovalent organic group, a halogen atom, or a hydrogen atom.

[0128] The details of each functional group are the same as those in formula (A) above, and therefore will not be described here.

[0129] An example of such a compound is the compound represented by the following formula (2-1): In formula (2-1), the details of each functional group are the same as those in formula (A), and therefore will not be described further. １ and R ４ is more preferably an alkyl group having 1 to 30, 1 to 12, or 1 to 4 carbon atoms or a hydrogen atom, and even more preferably a hydrogen atom. １ and R ４ may all be hydrogen atoms.

[0130]

[0131] The vinylbenzyl compound may include a compound represented by the following formula (3):

[0132]

[0133] In formula (3), R １ are each independently a monovalent organic group, a halogen atom, or a hydrogen atom, and R ４ are each independently a monovalent organic group, a halogen atom, or a hydrogen atom, and R １１ and R １２ are each independently a divalent aliphatic hydrocarbon group or a single bond, and R １３ is a monovalent organic group, a halogen atom, or a hydrogen atom.

[0134] The details of each substituent are the same as those of formula (A) above, and therefore will not be described here.

[0135] An example of such a compound is the compound represented by the following formula (3-1): In formula (3-1), the details of each functional group are the same as those in formula (A), and therefore will not be described further. １ and R ４ is more preferably an alkyl group having 1 to 30, 1 to 12, or 1 to 4 carbon atoms or a hydrogen atom, and even more preferably a hydrogen atom. １ and R ４ may all be hydrogen atoms.

[0136]

[0137] The weight-average molecular weight (Mw) of the vinylbenzyl compound will be described below. The weight-average molecular weight (Mw) of the vinylbenzyl compound may be 100,000 or less, 50,000 or less, 10,000 or less, 5,000 or less, or 2,000 or less. Within these ranges, the curable composition can have better solvent solubility and coatability, and the coating film, semi-cured product, and cured product can have better moldability and flexibility. The weight-average molecular weight (Mw) of the vinylbenzyl compound may be 400 or more, 500 or more, 800 or more, or 1,000 or more. Within these ranges, the curable composition can have better solvent solubility and coatability, and the coating film, semi-cured product, and cured product can have better moldability and flexibility. For example, the weight average molecular weight (Mw) of the vinylbenzyl compound may be 400 to 100,000, 400 to 50,000, 500 to 10,000, 800 to 5,000, or 1,000 to 2,000.

[0138] The vinylphenyl compounds may be used alone or in combination of two or more.

[0139] When the vinylphenyl compound contains a vinylbenzyl compound, the content of the vinylbenzyl compound is, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the total mass of the vinylphenyl compounds. The upper limit of the content of the vinylbenzyl compound may be 100% by mass. When the vinylphenyl compound contains a vinylbenzyl ether compound, the content of the vinylbenzyl ether compound is, for example, 70% by mass or more, 80% by mass or more, or 90% by mass or more, based on the mass of the vinylphenyl compounds. The upper limit of the content of the vinylbenzyl ether compound may be 100% by mass. When the curable composition contains a vinylbenzyl ether compound, tracking resistance tends to be improved.

[0140] [Compound Having a Maleimide Group] The maleimide compound is a compound having at least one maleimide group. The maleimide compound has, for example, 1 to 20, 1 to 15, or 1 to 10 maleimide groups. The maleimide compounds may be used alone or in combination of two or more.

[0141] The maleimide compound may be liquid at 25° C. or solid at 25° C. The maleimide compound may be a radically polymerizable monomer or polymer.

[0142] In some embodiments, the maleimide compound includes a compound having two maleimide groups. In the present disclosure, a compound having two maleimide groups may be referred to as a "bismaleimide." In some embodiments, the maleimide compound includes a compound having three or more maleimide groups.

[0143] The maleimide group can be represented by the following formula: * indicates the bonding position to other atoms. In the formula, R １ and R ２ each independently represents a hydrogen atom, an alkyl group, or a halogen atom.

[0144] In some embodiments, the maleimide compound comprises a compound represented by formula (m):

[0145] In formula (m), X ｍ represents an organic group, and M represents a maleimide group.

[0146] X ｍ The organic group represented by the formula (I) may be a group containing at least one carbon atom, and may be, for example, a group containing at least one selected from the group consisting of a saturated aliphatic hydrocarbon group, an unsaturated aliphatic hydrocarbon group, an aromatic hydrocarbon group, a saturated alicyclic hydrocarbon group, and an unsaturated alicyclic hydrocarbon group. The organic group may further contain a linking group containing a hetero atom, a substituent containing a hetero atom, or the like.

[0147] The maleimide compound preferably contains a compound represented by the following formula (m-1):

[0148]

[0149] In formula (m-2), R １ ~R ４ R each independently represents a hydrogen atom, an alkyl group or a halogen atom, and Y represents a hydrocarbon group. １ ~R ４are each independently preferably a hydrogen atom. The hydrocarbon group represented by Y may have 5 or more carbon atoms, or may have 10 or more carbon atoms. The hydrocarbon group represented by Y may have 30 or less carbon atoms, or may have 20 or less carbon atoms.

[0150] Alternatively, a maleimide compound may be synthesized. The method for synthesizing the maleimide compound is not particularly limited. For example, a synthesis method may be used in which a primary amine and maleic anhydride are used as raw materials to produce a maleamic acid or a maleamic acid ester as a maleimide precursor, followed by ring closure by dehydration or dealcoholization. The alkyl group of the primary amine may be, for example, a group containing at least one selected from the group consisting of a saturated aliphatic hydrocarbon group, an unsaturated aliphatic hydrocarbon group, an aromatic hydrocarbon group, a saturated alicyclic hydrocarbon group, and an unsaturated alicyclic hydrocarbon group.

[0151] The content of the maleimide compound may be, for example, 10% by mass or more, 15% by mass or more, or 25% by mass or more, based on the total mass of the vinylphenyl compound and the maleimide compound. When the content of the maleimide compound is 10% by mass or more, the cured product tends to exhibit better heat resistance. Furthermore, the content of the maleimide compound may be 90% by mass or less, 85% by mass or less, 80% by mass or less, 70% by mass or less, or 60% by mass or less. When the content of the maleimide compound is 90% by mass or less, the linear thermal expansion coefficient of the cured product can be kept low.

[0152] From the viewpoints of dielectric properties, curability, and conductor adhesion, the molar ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) in the curable composition is preferably 0.05 or more, preferably 0.10 or more, more preferably 0.30 or more, even more preferably 0.50 or more, and particularly preferably 0.70 or more. Furthermore, from the viewpoints of dielectric properties, curability, and conductor adhesion, the molar ratio (maleimide groups / vinylphenyl groups) is preferably 5.0 or less, more preferably 2.0 or less, and even more preferably 1.5 or less. The molar ratio (maleimide groups / vinylphenyl groups) may be, for example, 1.0 or less, 0.6 or less, 0.4 or less, or 0.3 or less. From the above viewpoints, the molar ratio (maleimide groups / vinylphenyl groups) may be 0.05 to 5.0.

[0153] The total content of the vinylphenyl compound and the maleimide compound in the curable composition is preferably, for example, 70% by mass to 100% by mass, 80% by mass to 100% by mass, or 90% by mass to 100% by mass, based on the total amount of the specific curable components. When the total content is 70% by mass or more, the cured product tends to exhibit better heat resistance and a lower coefficient of linear thermal expansion.

[0154] [Inorganic Filler] The curable composition according to the first embodiment contains at least one inorganic filler (specific inorganic filler) selected from the group consisting of titanium oxide, calcium titanate, and strontium titanate. The specific inorganic filler has a relatively high dielectric constant.

[0155] The specific inorganic filler may be used alone or in combination of two or more. For example, specific inorganic fillers of different materials may be used in combination, or specific inorganic fillers of the same material but different average particle sizes may be used in combination. The specific inorganic filler may be in the form of powder, beads formed by molding powder into a spherical shape, fiber, etc.

[0156] The specific inorganic filler preferably contains calcium titanate. The content of calcium titanate in the specific inorganic filler may be 50% by mass to 100% by mass, 70% by mass to 100% by mass, or 90% by mass to 100% by mass.

[0157] The curable composition according to the first embodiment may contain an inorganic filler other than the specific inorganic filler (also referred to as "other inorganic filler"). The type of other inorganic filler is not particularly limited. Examples of the other inorganic filler include silica such as fused silica and crystalline silica; alumina, zirconia, glass, talc, clay, mica, barium titanate, and potassium titanate. The inorganic filler may be an inorganic filler having a flame retardant effect. Examples of the inorganic filler having a flame retardant effect include aluminum hydroxide; magnesium hydroxide; composite metal hydroxides such as a composite hydroxide of magnesium and zinc; and zinc borate.

[0158] In the first embodiment, the other inorganic filler may be used alone or in combination of two or more. For example, other inorganic fillers of different materials may be used in combination, or other inorganic fillers of the same material but different average particle diameters may be used in combination.

[0159] In the first embodiment, the other inorganic filler may include silica from the viewpoint of reducing the linear expansion coefficient. The other inorganic filler may include alumina from the viewpoint of high thermal conductivity. The other inorganic filler may be in the form of powder, beads formed by molding powder into a spherical shape, fiber, or the like.

[0160] The curable composition according to the second embodiment contains an inorganic filler.

[0161] In the second embodiment, the inorganic filler may be used alone or in combination of two or more. For example, inorganic fillers of different materials may be used in combination, or inorganic fillers of the same material but different average particle sizes may be used in combination. Examples of the form of the inorganic filler include powder, beads formed by molding powder into a spherical shape, and fibers.

[0162] In the second embodiment, examples of inorganic fillers include silica such as fused silica and crystalline silica; alumina, zirconia, glass, talc, clay, mica, titanium oxide, calcium titanate, strontium titanate, barium titanate, and potassium titanate. The inorganic filler may be an inorganic filler having a flame retardant effect. Examples of inorganic fillers having a flame retardant effect include aluminum hydroxide; magnesium hydroxide; composite metal hydroxides such as composite hydroxide of magnesium and zinc; and zinc borate.

[0163] In the second embodiment, the inorganic filler may include silica from the viewpoint of reducing the linear expansion coefficient. The inorganic filler may include alumina from the viewpoint of high thermal conductivity. The inorganic filler may include at least one inorganic filler selected from the group consisting of titanium oxide, calcium titanate, and strontium titanate from the viewpoint of a balance between a high dielectric constant and a low dielectric loss tangent.

[0164] The average particle size of the inorganic filler is not particularly limited, and is preferably 0.1 μm to 10 μm, and more preferably 0.3 μm to 5 μm. When the average particle size of the inorganic filler is 0.1 μm or more, dispersibility in the curable component improves, and the flow characteristics of the curable composition tend to be further improved. When the average particle size of the inorganic filler is 10 μm or less, sedimentation of the inorganic filler is more easily suppressed, and permeability and flowability into fine gaps tend to be improved, and the occurrence of voids or unfilled portions tends to be further suppressed. The average particle size of the inorganic filler may be interpreted as the average particle size of a specific inorganic filler or the average particle size of other inorganic fillers.

[0165] The average particle size of the inorganic filler can be determined by the following method. A thin section sample is prepared from the curable composition or a cured product of the curable composition. 100 particles of the inorganic filler are randomly selected from an image of the thin section sample taken with a scanning electron microscope. The major axis of each particle is measured, and the arithmetic average value is used as the average particle size of the inorganic filler.

[0166] In the first embodiment, when the curable composition contains a specific inorganic filler and other inorganic fillers, the content of the specific inorganic filler relative to the total amount of inorganic fillers is not particularly limited. For example, the content of the specific inorganic filler relative to the total amount of inorganic fillers may be 10% by mass to 90% by mass, 20% by mass to 80% by mass, or 30% by mass to 70% by mass. The content of the specific inorganic filler relative to the total amount of inorganic fillers may be appropriately adjusted in consideration of the balance between the dielectric properties, fluidity, high thermal conductivity, and the like of the curable composition.

[0167] The content of the inorganic filler (which may be read as the total content of the specific inorganic filler and other inorganic fillers) may be 25 parts by mass or more, 50 parts by mass or more, or 100 parts by mass or more, relative to 100 parts by mass of the total curable components. It may also be 2000 parts by mass or less, 1500 parts by mass or less, or 1000 parts by mass or less, relative to 100 parts by mass of the total curable components. When the content of the inorganic filler is 25 parts by mass or more, the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus, tend to be further improved. When the content of the inorganic filler is 2000 parts by mass or less, an increase in the viscosity of the curable composition is suppressed, and the flowability tends to be further improved.

[0168] The content of the inorganic filler (which may be read as the total content of the specific inorganic filler and other inorganic fillers) may be, for example, 20% by mass or more, 35% by mass or more, 40% by mass or more, or 50% by mass or more based on the mass of the curable composition, and the content of the inorganic filler may be 95% by mass or less, 90% by mass or less, 85% by mass or less, or 80% by mass or less.

[0169] The content of the inorganic filler (which may be read as the total content of the specific inorganic filler and other inorganic fillers) may be, for example, 15% by volume or more, 35% by volume or more, 40% by volume or more, 50% by volume or more, or 60% by volume or more, based on the volume of the curable composition. The content of the inorganic filler may also be 90% by volume or less, 85% by volume or less, 80% by volume or less, or 75% by volume or less. When the content of the inorganic filler is 15% by volume or more, the properties of the cured product, such as the thermal expansion coefficient, thermal conductivity, and elastic modulus, tend to be further improved. When the content of the inorganic filler is 90% by volume or less, the increase in viscosity of the curable composition is suppressed, and the flowability tends to be further improved.

[0170] A cured product obtained using the curable composition can be used as an encapsulant for encapsulating electronic components such as semiconductor elements.

[0171] [Other Components] The curable composition may contain other components in addition to the specific curable component and inorganic filler. The curable composition may further contain at least one selected from the group consisting of a radical polymerization initiator and a polymerization inhibitor, and may further contain other optional components. Examples of optional components include various additives such as coupling agents, mold release agents, colorants, ion exchangers, flame retardants, and stress relaxation agents. The curable composition may contain various additives as needed in addition to the following examples.

[0172] (Radical Polymerization Initiator) The curable composition may contain a radical polymerization initiator. When the curable composition is cured by heating, the radical polymerization initiator may be a thermal radical polymerization initiator that generates free radicals by heating. The thermal radical polymerization initiator may be, for example, an organic peroxide such as peroxyketal or dialkyl peroxide, or an azo compound such as azobisbutyronitrile or azobispropionitrile.

[0173] Examples of organic peroxides include 1,1,3,3-tetramethylbutylperoxyneodecanoate, di(4-t-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxydicarbonate, cumylperoxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethylperoxyneodecanoate, t-hexylperoxyneodecanoate, t-butylperoxyneodecanoate, and t-butylperoxyneodecanoate. Pivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, t-hexylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, t-butylperoxyneoheptanoate, t-amylperoxy-2-ethylhexanoate, di-t-butylperoxyhexahydroterephthalate, t-amylperoxy-3,5, 5-trimethylhexanoate, 3-hydroxy-1,1-dimethylbutylperoxyneodecanoate, t-amylperoxyneodecanoate, di(3-methylbenzoyl) peroxide, dibenzoyl peroxide, di(4-methylbenzoyl) peroxide, t-hexylperoxyisopropyl monocarbonate, t-butylperoxymaleic acid, t-butylperoxy-3,5,5-trimethylhexanoate, t-butylperoxylaurate, 2, Examples of such peroxyalkylene compounds include 5-dimethyl-2,5-di(3-methylbenzoylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butyl peroxybenzoate, dibutyl peroxytrimethyl adipate, t-amyl peroxy normal octoate, t-amyl peroxy isononanoate, and t-amyl peroxybenzoate.

[0174] Examples of azo compounds include 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 4,4'-azobis(4-cyanovaleric acid), and 1,1'-azobis(1-cyclohexanecarbonitrile).

[0175] When the curable composition contains a radical polymerization initiator, the radical polymerization initiator may be used alone or in combination of two or more. When the curable composition contains a radical polymerization initiator, the content of the radical polymerization initiator may be 0.1% by mass to 30% by mass, 0.1% by mass to 10% by mass, or 0.2% by mass to 3% by mass based on the total mass of the vinylphenyl compound and any vinyl compound other than the vinylphenyl compound that is optionally contained (which may be 0% by mass).

[0176] (Coupling Agent) The curable composition may contain a coupling agent. When the curable composition contains a coupling agent, the adhesiveness of the cured product or the adhesiveness between the curable component and the inorganic filler tends to be improved. Examples of coupling agents include silane coupling agents, titanate coupling agents, aluminum chelate coupling agents, and aluminum-zirconium coupling agents. Examples of the silane coupling agent include epoxy silane coupling agents, mercapto silane coupling agents, amino silane coupling agents, alkyl silane coupling agents, ureido silane coupling agents, vinyl silane coupling agents, (meth)acrylic silane coupling agents, and disilazane coupling agents. In the present disclosure, coupling agents having a vinylphenyl group are excluded from the scope of the above-mentioned vinylphenyl compound. In other words, vinylphenyl compounds are compounds other than compounds that fall under the category of coupling agents.

[0177] Examples of silane coupling agents include vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, γ-methacryloxypropyltrimethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, and N-phenyl-3-aminopropyl Trimethoxysilane, γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-anilinopropyltrimethoxysilane, γ-anilinopropyltriethoxysilane, γ-(N,N-dimethyl)aminopropyltrimethoxysilane, γ-(N,N-diethyl)aminopropyltrimethoxysilane, γ-(N,N-dibutyl)aminopropyltrimethoxysilane, γ-(N-methyl)anilinopropyltrimethoxysilane, γ-(N-ethyl)anilinopropyltrimethoxysilane γ-(N,N-dimethyl)aminopropyltrimethoxysilane, γ-(N,N-diethyl)aminopropyltriethoxysilane, γ-(N,N-dibutyl)aminopropyltriethoxysilane, γ-(N-methyl)anilinopropyltriethoxysilane, γ-(N-ethyl)anilinopropyltriethoxysilane, γ-(N,N-dimethyl)aminopropylmethyldimethoxysilane, γ-(N,N-diethyl)aminopropylmethyldimethoxysilane, γ-(N,N-dibutyl)aminopropyl Examples of such silane include methyldimethoxysilane, γ-(N-methyl)anilinopropylmethyldimethoxysilane, γ-(N-ethyl)anilinopropylmethyldimethoxysilane, N-(trimethoxysilylpropyl)ethylenediamine, N-(dimethoxymethylsilylisopropyl)ethylenediamine, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, γ-chloropropyltrimethoxysilane, hexamethyldisilane, vinyltrimethoxysilane, and γ-mercaptopropylmethyldimethoxysilane.

[0178] When the curable composition contains a coupling agent, the coupling agent may be used alone or in combination of two or more. When the curable composition contains an inorganic filler and a coupling agent, the amount is preferably 0.05 to 5 parts by mass, more preferably 0.1 to 2.5 parts by mass, per 100 parts by mass of the filler. When the content of the coupling agent is 0.05% by mass or more, the adhesiveness of the cured product tends to be improved.

[0179] (Mold Release Agent) The curable composition may contain a mold release agent. When the curable composition contains a mold release agent, good mold releasability from the mold during molding is easily obtained. Examples of the mold release agent include known mold release agents such as carnauba wax; higher fatty acids such as montanic acid and stearic acid, higher fatty acid metal salts; ester waxes such as montanic acid esters; and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene.

[0180] When the curable composition contains a release agent, the release agent may be used alone or in combination of two or more. When the curable composition contains a release agent, the content of the release agent may be, for example, 0.01 mass% or more, 0.05 mass% or more, or 0.1 mass% or more, based on the total mass of the curable components, and may be 10 mass% or less, 5 mass% or less, or 2 mass% or less. When the content of the release agent is 0.01 mass% or more, sufficient releasability tends to be obtained. When the content of the release agent is 10 mass% or less, better adhesion tends to be obtained.

[0181] (Colorant) The curable composition may contain a colorant. Examples of the colorant include known colorants such as carbon black, organic dyes, organic pigments, red lead, and red iron oxide. The content of the colorant can be appropriately selected depending on the purpose, etc. The colorant may also function as a filler.

[0182] When the curable composition contains a colorant, the colorant may be used alone or in combination of two or more. When the curable composition contains a colorant, the content of the colorant is, for example, 0.01% by mass to 10% by mass or 0.1% by mass to 5% by mass based on the total mass of the vinylphenyl compound and the maleimide compound contained as needed.

[0183] (Polymerization inhibitor) The curable composition may contain a polymerization inhibitor. Examples of the polymerization inhibitor include phenolic compounds such as hydroquinone, methylhydroquinone, hydroquinone monomethyl ether, catechol, and pyrogallol; hindered amine compounds, piperidine derivatives, and phenothiazine derivatives.

[0184] (Ion Exchanger) The curable composition may contain an ion exchanger. When the curable composition contains an ion exchanger, the moisture resistance and high-temperature storage characteristics of the electronic component device tend to be improved. Examples of the ion exchanger include hydrotalcite compounds; and hydrous oxides of at least one element selected from the group consisting of magnesium, aluminum, titanium, zirconium, and bismuth. The ion exchanger may also function as a filler. The curable composition may use one type of ion exchanger alone, or two or more types may be used in combination.

[0185] (Flame Retardant) The curable composition may contain a flame retardant. Examples of the flame retardant include organic or inorganic compounds containing a halogen atom, an antimony atom, a nitrogen atom, or a phosphorus atom, and metal hydroxides. The curable composition may contain one flame retardant alone or two or more flame retardants in combination.

[0186] (Stress Relaxant) The curable composition may contain a stress relaxation agent. When the curable composition contains a stress relaxation agent, warpage and cracking of electronic component devices tend to be reduced. Examples of stress relaxation agents include silicone oil; thermoplastic elastomers such as silicone, styrene, olefin, urethane, polyester, polyether, polyamide, and polybutadiene elastomers; rubber particles such as NR (natural rubber), NBR (acrylonitrile-butadiene rubber), acrylic rubber, urethane rubber, and silicone powder; and rubber particles having a core-shell structure such as methyl methacrylate-styrene-butadiene copolymer (MBS), methyl methacrylate-silicone copolymer, and methyl methacrylate-butyl acrylate copolymer (excluding compounds having a vinyl group in the molecule). When the curable composition contains a stress relaxation agent, the curable composition may use one type of stress relaxation agent alone, or two or more types of stress relaxation agents in combination. Commercially available flexibility-imparting agents can be used as the stress relaxation agent.

[0187] [Dielectric Properties of Cured Product] In some embodiments, the curable composition has a dielectric loss tangent (Df) at 10 GHz of, for example, 0.010 or less, 0.0060 or less, 0.0055 or less, or 0.0050 or less when cured. A cured product with a low dielectric loss tangent suppresses a decrease in communication efficiency in electronic devices that use high-frequency radio waves for communication.

[0188] In some embodiments, the curable composition may have a dielectric constant (Dk) at 10 GHz when cured, for example, from 5 to 25, from 7 to 20, or from 10 to 20.

[0189] The cured product for measuring Df and Dk was a molded product measuring 0.5 mm in length, 0.5 mm in width, and 50 mm in height, obtained by loading the curable composition into a vacuum hand press, molding it under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds, and then post-curing it for 5 hours at 175°C. Using this cured product as a test piece, the relative permittivity (Dk) and dielectric loss tangent (Df) at a temperature of 25±3°C and 10 GHz were measured using a dielectric constant measuring device (Agilent Technologies, product name "Network Analyzer N5227A").

[0190] [Uses of Curable Composition] The curable composition of the present disclosure is suitable as a sealant for electronic component devices that use high-frequency radio waves for communication. The curable composition of the present disclosure is also suitable for use as a dielectric substrate, a sealant for a high-frequency device, a material that forms part of a high-frequency device, etc.

[0191] <Electronic Component Device> In some embodiments, the electronic component device includes, for example, an electronic component and a cured product of the curable composition of the present disclosure that encapsulates at least a portion of the electronic component. The electronic component device may be, for example, an electronic component module that includes a plurality of electronic components and electronic component devices and the encapsulant of the above embodiment that encapsulates at least a portion of the plurality of electronic components.

[0192] Examples of electronic components include active elements or components such as diodes, transistors, integrated circuits, and relays; passive elements or components such as resistors, capacitors, and coils; connectors, support members, terminals, and switches. Examples of electronic component devices include electronic component devices having the electronic components; and modules having one or both of the electronic components and the electronic component devices. The electronic component device may have a support member. Examples of support members include lead frames, pre-wired tape carriers, wiring boards, glass, silicon wafers, and organic substrates.

[0193] In particular, in recent years, with the spread of fifth-generation mobile communication systems (5G), semiconductor packages (PKGs) used in electronic component devices have become increasingly sophisticated and miniaturized. As PKGs become smaller and more sophisticated, the development of antenna-in-package (AiP), which is a PKG with an antenna function, has also progressed. In AiPs, radio waves used for communication are becoming higher in frequency to accommodate the increasing number of channels associated with the diversification of information, and sealing materials are required to have both a high dielectric constant and a low dielectric loss tangent. In curable compositions, adjusting the composition of the inorganic filler can achieve both a high dielectric constant and a low dielectric loss tangent. Therefore, in high-frequency devices, the curable composition can also be applied to antenna-in-package (AiPs) in which an antenna arranged on a support member is sealed with the curable composition.

[0194] For example, one example of a method for manufacturing an electronic component device includes placing an electronic component on a support member and encapsulating at least a portion of the electronic component with the curable composition of the present disclosure. Methods for encapsulating electronic components include various molding methods such as injection molding, transfer molding, and compression molding.

[0195] In a method for producing an electronic component device, at least a portion of the electronic component may be encapsulated by injection molding using the curable composition of the present disclosure.

[0196] The curable composition of the present disclosure tends to have a lower viscosity during injection molding than a thermoplastic resin, and tends to enable injection molding at a lower pressure, which enables molding at a lower pressure and temperature when encapsulating electronic components by injection molding, and also reduces damage to the electronic components.

[0197] In the method for manufacturing an electronic component device, at least a portion of the electronic component may be encapsulated by transfer molding using the curable composition of the present disclosure, or at least a portion of the electronic component may be encapsulated by compression molding using the curable composition of the present disclosure.

[0198] For example, another example of a method for manufacturing an electronic component device includes placing an electronic component on a support member and encapsulating at least a portion of the electronic component with the curable composition of the present disclosure by injection molding.

[0199] The curable composition of the present disclosure tends to have a lower viscosity during injection molding than a thermoplastic resin, and tends to enable injection molding at a lower pressure, which enables molding at a lower pressure and temperature when encapsulating electronic components by injection molding, and also reduces damage to the electronic components.

[0200] An example of a method for manufacturing an electronic component device using an injection molding machine is shown in Fig. 1. The injection molding machine 10 shown in Fig. 1 includes a mold 1 and an injector 3 that supplies a curable composition into a cavity 2 of the mold 1.

[0201] The mold 1 is formed by a movable mold 1a and a fixed mold 1b. A support member (not shown) on which an electronic component is arranged is placed in a cavity 2 of the mold 1, and a curable composition is supplied from a nozzle 6 of an injection machine 3.

[0202] The injector 3 includes a hopper 4 which is a supply unit to which the components of the curable composition are supplied, a cylinder 5 which stirs the mixture of the components supplied from the hopper 4 with a screw or the like, and a nozzle 6 provided upstream of the cylinder 5. The configuration of the injector 3 is not limited to that shown in Fig. 1 as long as it can inject and fill the molten curable composition into the cavity 2.

[0203] As shown by arrow A in (a) of Figure 1, each component of the curable composition is supplied from a hopper 4 to a cylinder 5. As shown in (b) of Figure 1, the mixture of each component is heated and stirred in the cylinder 5 to prepare a curable composition. The heating temperature of the curable composition in the cylinder 5 may be within a range in which the curing reaction does not proceed, and may be, for example, 50°C to 100°C, 60°C to 80°C, or approximately 70°C. When the mixture is stirred with a screw, the screw speed may be, for example, 30 rpm (revolutions per minute) to 100 rpm, 40 rpm to 80 rpm, or approximately 50 rpm.

[0204] As shown in (c) of Figure 1, the curable composition prepared in the cylinder 5 is supplied from the nozzle 6 into the cavity 2 of the mold 1 at a predetermined injection pressure, injection speed, and injection time. The injection pressure may be, for example, 1 MPa to 10 MPa, 2 MPa to 8 MPa, or about 5 MPa. The injection speed is 0.5 cm ３ / sec~10cm ３ / sec, or 1cm ３ / sec~8cm ３ / sec, or 5cm ３ The injection time may be 30 to 300 seconds, 50 to 200 seconds, or about 140 seconds.

[0205] The heating temperature of the curable composition in cavity 2 (also referred to as temperature T1 (unit: °C)) is preferably higher than the heating temperature of the curable composition in cylinder 5 (also referred to as temperature T2 (unit: °C)), and may satisfy, for example, T1≧T2+40, T2+50≦T1≦150, or T2+80≦T1≦130. The heating time of the curable composition in cavity 2 may be 30 to 300 seconds, 50 to 200 seconds, or about 140 seconds.

[0206] After heating the curable composition in the cavity 2, the fixed mold 1b and the movable mold 1a are opened, and the molded product is removed from the mold 1. If necessary, the molded product may be post-cured at 150°C to 200°C for a curing time of 30 minutes to 10 hours (for example, 6 hours at 175°C). This provides an electronic component device in which at least a portion of the electronic component is sealed with a cured product of the curable composition of the present disclosure.

[0207] <High-frequency device> The high-frequency device of the present disclosure has a cured product of the curable composition of the present disclosure. Examples of high-frequency devices include a microstrip antenna, a dielectric waveguide, and a multilayer antenna.

[0208] <Dielectric Substrate> The dielectric substrate of the present disclosure is obtained by curing the curable composition of the present disclosure. For example, the dielectric substrate of the present disclosure is used to form a microstrip antenna, which will be described later.

[0209] <Microstrip Antenna> The microstrip antenna of the present disclosure includes a dielectric substrate formed by curing the curable composition of the present disclosure, a radiating element provided on one surface of the dielectric substrate, and a ground conductor plate provided on the other surface of the dielectric substrate.

[0210] The radiating element is preferably a member containing any of a metal material, an alloy of a metal material, a hardened metal paste, and a conductive polymer. The shape of the radiating element may be rectangular, circular, or the like.

[0211] The microstrip antenna preferably has a radiating element of length L and width W, and resonates at a frequency where L is an integer multiple of one-half wavelength.

[0212] The ground conductor plate is a plate-like member made of a highly conductive metal such as copper, silver, gold, etc. The thickness of the ground conductor plate is preferably sufficiently thin compared to the central operating frequency of the antenna device, and is preferably, for example, about 1 / 50 to 1 / 1000 of the wavelength of the central operating frequency.

[0213] <Dielectric Waveguide> A dielectric waveguide comprises a dielectric obtained by curing the curable composition of the present disclosure and a conductive film covering the surface of the dielectric. The dielectric waveguide confines and transmits electromagnetic waves within the dielectric. The conductive film is made of a metal such as copper, a high-temperature oxide superconductor, or the like.

[0214] <Multilayer Antenna> The multilayer antenna includes a dielectric obtained by curing the curable composition of the present disclosure and a circuit provided on the dielectric, and has a structure in which the dielectric and the circuit are laminated. Examples of the circuit include elements such as capacitors and inductors. The dielectric may be a sheet-like member (dielectric sheet). For example, the multilayer antenna may be a laminate of dielectric sheets on which circuits consisting of elements such as capacitors and inductors are printed.

[0215] The embodiments of the present disclosure will be specifically described with reference to examples, but the embodiments of the present disclosure are not limited to the following examples.

[0216] <Synthesis of Vinylphenyl Compound> A 500 mL reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was charged with 35.6 parts by mass of indene, 99.1 parts by mass of chloromethylstyrene, 7.1 parts by mass of tetra-n-butylammonium bromide as a phase transfer catalyst, 0.1 parts by mass of phenothiazine as a polymerization inhibitor, and 76.4 parts by mass of toluene as a solvent. The resulting composition was stirred at 40°C while blowing in nitrogen at a flow rate of 50 mL / min. The chloromethylstyrene used was a mixture of o-chloromethylstyrene and p-chloromethylstyrene (Wujin Linchuan Chemical Co., Ltd., o-chloromethylstyrene content 17% by mass, p-chloromethylstyrene content 83% by mass).

[0217] Next, 46.5 parts by mass of a sodium hydroxide aqueous solution (concentration 48% by mass) as a basic compound was added dropwise over 20 minutes, and the mixture was further stirred at 60°C for 9 hours. Nitrogen was continuously blown in during the reaction. The composition was cooled to room temperature (25°C), neutralized with a 10% by mass aqueous hydrochloric acid solution, and then washed twice with pure water. Thereafter, toluene was distilled off under reduced pressure, and the resulting viscous liquid was washed with methanol and then vacuum-dried to obtain a vinylphenyl compound.

[0218] Vinylphenyl compounds are １ H-nuclear magnetic resonance ( １ H-NMR analysis confirmed that the compound had a structure in which substantially all of the two hydrogen atoms directly bonded to the carbon atom at position 1 of indene were substituted with vinylbenzyl groups (vinylphenylmethyl groups). GPC analysis confirmed that the vinylphenyl compound was a mixture of a compound having two vinylbenzyl groups and a compound having three vinylbenzyl groups, and that the average number of vinylbenzyl groups was in the range of 1.8 to 2.6. The weight-average molecular weight (Mw) of the vinylphenyl compound was 500.

[0219]

[0220] In the examples, the weight average molecular weight (Mw) was calculated by gel permeation chromatography (GPC) using a calibration curve prepared using standard polystyrene. The calibration curve was approximated by a cubic equation using standard polystyrene: TSKstandard POLYSTYRENE (Types: A-2500, A-5000, F-20, F-80) (Tosoh Corporation). Apparatus: High-speed GPC apparatus HLC-8320GPC (Tosoh Corporation) Detector: Ultraviolet absorption detector UV-8320 (Tosoh Corporation) Columns: Guard column; TSKgel guard column Super (HZ)-M + Column; TSKgel SuperMultipore HZ-M (2 columns), Reference column; TSKgel Super H-RC (2 columns) (all Tosoh Corporation) Column size: 4.6 x 20 mm (guard column), 4.6 x 150 mm (column), 6.0 x 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 10 mg / 1 mL Injection volume: 20 μL or 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0221] <Preparation of Curable Composition> The vinylphenyl compounds obtained above were each placed in a metal tray and left to stand in a vacuum dryer at 0.1 MPa or less and a temperature of 70° C. for 5 hours to remove the solvent.

[0222] [Examples 1A to 4A and Comparative Example 1A] A solid curable composition was produced by mixing vinylphenyl compound 1 after removing the solvent with each component listed in Table 1. In each example, the molar content ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) was 1.0.

[0223] Example 5A A solid vinylphenyl compound 2 (resin (I)) synthesized as follows was mixed with the components listed in Table 1 to produce a solid curable composition. In Example 5A, the molar content ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) was 1.0. - Synthesis of Resin (I) - A reaction vessel equipped with a stirrer, thermometer, reflux condenser, and nitrogen inlet was charged with 116.16 parts by mass of indene, 113.78 parts by mass of p-xylylene dichloride, 15.5 parts by mass of tetra-n-butylammonium bromide (Kanto Chemical Co., Inc.), 0.90 parts by mass of phenothiazine, and 700 parts by mass of toluene, and the mixture was heated and stirred at 40°C while blowing in nitrogen at a flow rate of 50 ml / min. Next, 369 parts by mass of an aqueous sodium hydroxide solution (concentration 48% by mass) was added, and the temperature was raised to 70°C. Stirring was continued, and after confirming the reaction of p-xylylene dichloride using a nuclear magnetic resonance spectrometer, 122.10 parts by mass of chloromethylstyrene was added. The reaction was further carried out at 70°C, and the reaction was terminated after confirming the reaction of chloromethylstyrene using a nuclear magnetic resonance spectrometer. The reaction mixture was cooled to room temperature (25°C), neutralized with a 10% aqueous hydrochloric acid solution, and then washed twice with pure water. After distilling off the toluene under reduced pressure, the resulting viscous liquid was washed with methanol and dried in vacuo to obtain Resin (I).

[0224] The number average molecular weight (Mn) of resin (I) was 611, and the weight average molecular weight (Mw) was 839. In the chart of high performance liquid chromatography (HPLC) analysis under the conditions below, the total area ratio of the four peaks detected between 32 and 35 minutes was 52.44 area %. Furthermore, from the LC-MS analysis, it was estimated that each compound represented by the following structural formula was produced. (High-Performance Liquid Chromatography (HPLC) Analysis Conditions) Sample: 0.0001% by mass solution of resin in tetrahydrofuran Injection volume: 20 μL Mobile phase: tetrahydrofuran Flow rate: 0.8 ml / min Degasser: "DEGAS" (manufactured by Resonac Corporation, product name) Pump: "DS-4" (manufactured by Resonac Corporation, product name) Column: "SHODEX KF-802 + KF-801" x 3 (manufactured by Resonac Corporation, product name) Column temperature: 40°C Column oven: "AO-50" (manufactured by Resonac Corporation, product name) Detector: ultraviolet absorbance detector ("UV-41" manufactured by Resonac Corporation, measurement wavelength 254 nm)

[0225]

[0226] [Example 1B] A solid curable composition was produced by mixing the vinylphenyl compound after removing the solvent with each of the components shown in Table 2. The molar content ratio of maleimide groups to vinylphenyl groups (maleimide groups / vinylphenyl groups) was 3.3.

[0227] The components listed in Tables 1 and 2 are as follows: In Tables 1 and 2, the units for each component are "parts by mass." The average particle size of the inorganic filler was measured by the method described above.

[0228] Vinylphenyl compound 1: the vinylphenyl compound (vinylbenzyl compound) obtained above, which is liquid at room temperature. Vinylphenyl compound 2: the vinylphenyl compound (vinylbenzyl compound, resin (I)) obtained above, which is solid at room temperature. Maleimide compound: 4,4'-bismaleimidediphenylmethane, which is solid at room temperature. Epoxy resin 1: biphenyl aralkyl type epoxy resin, epoxy equivalent 274 g / eq. Epoxy resin 2: biphenyl type epoxy resin, epoxy equivalent 192 g / eq. Curing agent 1: biphenyl aralkyl type phenol resin, hydroxyl group equivalent 199 g / eq. Curing agent 2: active ester. Compound 1: DIC Corporation, product name "EXB-8". Curing accelerator: triphenylphosphine / 1,4-benzoquinone adduct. Coupling agent 1: N-phenyl-3-aminopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name "KBM-573") Coupling agent 2: 3-mercaptopropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., product name "KBM-803") Mold release agent 1: α-olefin-maleic anhydride copolymer Mold release agent 2: Montan acid ester wax (Clariant Japan KK, product name "HW-E") Mold release agent 3: oxidized polyethylene wax Colorant 1: carbon black (Mitsubishi Chemical Corporation, product name "MA600") Colorant 2: carbon black (Mitsubishi Chemical Corporation, product name "MA100RMJ") Additive: piperidine derivative Inorganic filler 1: alumina, average particle size 7 μm Inorganic filler 2: calcium titanate, average particle size 0.2 μm Inorganic filler 3: calcium titanate, average particle size 6 μm Inorganic filler 4: calcium titanate, average particle size 20 μm Inorganic filler 5: silica filler, average particle size 18 μm

[0229] <Preparation of Cured Product> A cured product was prepared using the curable composition, and the physical properties shown in Tables 1 and 2 were measured. The measurement results are shown in Tables 1 and 2.

[0230] (Measurement of dielectric properties (Df and Dk)) The curable composition was charged into a vacuum hand press and molded under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds. Post-curing was carried out at 175°C for 5 hours to obtain a cured product measuring 0.5 mm in length, 0.5 mm in width, and 50 mm in height. This cured product was used as a test piece and its relative permittivity (Dk) and dielectric loss tangent (Df) were measured at a temperature of 25±3°C and 10 GHz using a dielectric constant measuring device (Agilent Technologies, product name "Network Analyzer N5227A").

[0231] (Measurement of Gel Time) The gel time (seconds) was determined by measuring the time from when 0.5 g (Examples 1A to 5A and Comparative Example 1A) or 0.7 g (Example 1B) of the curable composition was placed on a hot plate preheated to 175°C to when the resin lost its viscosity.

[0232] (Molding Shrinkage) The molding shrinkage was determined in accordance with JIS K6911. The curable composition was molded using a transfer molding machine under conditions of a molding temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 120 seconds to obtain a disk-shaped molded product (diameter 90 mm, thickness 11 mm, outer diameter of the protruding annular portion 80 mm) with a protruding annular portion. The molded product was post-cured for 5 hours at 175°C to obtain a cured product. The molding shrinkage (%) was calculated using the following formula from the outer diameter length D of the annular portion of the mold at 25°C, which was measured in advance, and the outer diameter length d of the protruding annular portion of the cured product at room temperature (25°C). Molding shrinkage (%) = ((D - d) / D) × 100

[0233] (Measurement of Linear Expansion Coefficient) The curable composition was molded using a transfer molding machine under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds, followed by post-curing at 175°C for 5 hours. The cured product had a rectangular shape with a short side of 5.1 mm, a long side of 20 mm, and a thickness of 2 mm. The linear expansion coefficient α1 (ppm / °C) and the linear expansion coefficient α2 (ppm / °C) were measured using a thermomechanical analyzer (e.g., TMA / SS6100 manufactured by Seiko Instruments Inc.). The test load was 98 mN, and the heating rate was 5°C / min.

[0234] (Glass transition temperature (Tg) of cured product) For Examples 1A to 5A and Comparative Example 1A, the temperature at the intersection of the tangent line at 20°C to 40°C and the tangent line at 220°C to 260°C, obtained by the measurement of the linear expansion coefficient, was taken as the glass transition temperature (°C) of the cured product. For Example 1B, the temperature at the intersection of the tangent line at 10°C to 30°C and the tangent line at 200°C to 220°C, obtained by the measurement of the linear expansion coefficient, was taken as the glass transition temperature (°C) of the cured product.

[0235] (Spiral flow) Spiral flow was measured by using a spiral flow measurement mold conforming to EMMI-1-66, molding the curable composition under the conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds, and determining the flow distance (cm).

[0236] (Evaluation of burrs) The curable composition was charged into a transfer molding machine and molded at a mold temperature of 180°C, a molding pressure of 6.9 MPa, and a curing time of 120 seconds. After molding, the length of the portion through which the curable composition flowed the longest in slits of 50 μm, 30 μm, 20 μm, 10 μm, 5 μm, and 2 μm made in the mold was measured using a vernier caliper, and this measurement value was taken as the length (mm) of the burrs.

[0237] (Hot Hardness) The curable composition was charged into a transfer molding machine and molded into a disk having a diameter of 50 mm and a thickness of 3 mm under conditions of a mold temperature of 180°C, a molding pressure of 6.9 MPa, and a curing time of 90 seconds. Immediately after molding, the hardness was measured using a Shore D hardness tester (Ueshima Seisakusho Co., Ltd., HD-1120 (Type D)).

[0238] (Melt Viscosity (ηFT)) The melt viscosity (Poise) of the curable composition heated to 175° C. was measured using a flow tester.

[0239] (Measurement of flexural modulus, flexural strength, and flexural elongation at break) The curable composition was charged into a transfer molding machine and molded under conditions of a mold temperature of 175 ° C, a molding pressure of 6.9 MPa, and a curing time of 120 seconds. Post-curing was performed at 175 ° C for 6 hours to prepare rectangular parallelepiped test pieces measuring 127 mm × 12.7 mm × 4 mm. Using a Tensilon (A&D Co., Ltd.) as an evaluation device, a three-point support bending test in accordance with JIS-K-7171 (2016) was performed at room temperature (25 ° C), and the flexural modulus E, flexural strength S, and flexural elongation ε of the test piece were calculated using the following formulas.

[0240] The flexural modulus E (GPa), flexural strength S (MPa), and flexural elongation at break ε (%) are defined by the following formulas: where P is the load cell value (N), y is the displacement (mm), l is the span = 64 mm, w is the test piece width = 12.7 mm, and h is the test piece thickness = 4 mm. The subscript max indicates the maximum value.

[0241]

[0242]

[0243]

[0244] (Water Absorption) The curable composition was loaded into a vacuum hand press and molded under conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a curing time of 600 seconds. Post-curing was carried out at 180°C for 6 hours to obtain a plate-shaped cured product (length 12.5 mm, width 25 mm, thickness 0.2 mm). Immediately after production, the plate-shaped cured product was placed in a pressure cooker tester at 121°C / 2.1 atmospheres and removed after 24 hours. The increase in mass (%) from the mass immediately before loading was determined. Water absorption (mass%) = [(mass after loading - mass before loading) / mass before loading] x 100

[0245] (Disc flow) Using a flat plate mold for disc flow measurement having an upper mold of 200 mm (W) × 200 mm (D) × 25 mm (H) and a lower mold of 200 mm (W) × 200 mm (D) × 15 mm (H), 5 g of a curable composition weighed with a top-pan balance was placed on the center of the lower mold heated to 180°C, and after 5 seconds, the upper mold heated to 180°C was closed to perform compression molding under conditions of a load of 78 N and a curing time of 90 seconds. The major axis (mm) and minor axis (mm) of the molded product were measured with vernier calipers, and the average value (mm) was taken as the disc flow.

[0246]

[0247]

[0248] As shown in Table 1, Examples 1A to 5A, which contained a vinylphenyl compound and a maleimide compound, had lower dielectric loss tangents than Comparative Example 1A, which did not contain a vinylphenyl compound or a maleimide compound. Furthermore, Example 5A, which used a solid vinylphenyl compound, had an even lower dielectric loss tangent than Comparative Example 1A. Furthermore, Examples 1A to 5A produced cured products with lower mold shrinkage and higher heat resistance than Comparative Example 1A. As shown in Table 2, it was confirmed that the curable composition prepared in Example 1B had excellent flowability and could be used in injection molding.

[0249] The disclosures of Japanese Patent Application Nos. 2024-057285 and 2024-057286, filed on March 29, 2024, are incorporated herein by reference in their entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A curable composition comprising: a curable component that contains an ethylenically unsaturated double bond and is radically polymerizable; and an inorganic filler that is at least one selected from the group consisting of titanium oxide, calcium titanate, and strontium titanate.

2. A curable composition for injection molding, comprising: a curable component that contains an ethylenically unsaturated double bond and is radically polymerizable; and an inorganic filler.

3. A curable composition according to claim 1 or claim 2, wherein the curable component comprises at least one compound selected from the group consisting of compounds having a vinylphenyl group and compounds having a maleimide group.

4. A curable composition according to any one of claims 1 to 3, wherein the curable component comprises a compound having a vinylphenyl group that is liquid at 25°C and a compound having a maleimide group that is solid at 25°C.

5. The curable composition according to any one of claims 1 to 4, wherein the curable component comprises a compound having a vinylphenyl group and a compound having a maleimide group, and the molar ratio of the maleimide group to the vinylphenyl group (maleimide group / vinylphenyl group) is 0.05 to 5.

0.

6. The curable composition according to any one of claims 1 to 5, which is solid at 25°C.

7. The curable composition according to any one of claims 1 to 6, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a compound represented by the following formula (b1): (In the formula, X ｂ１ represents an organic group, each B independently represents a group containing a vinylphenyl group, and 1 represents an integer of 1 to 5.

8. The curable composition according to any one of claims 1 to 7, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a compound having two or more vinylphenyl groups.

9. The curable composition according to any one of claims 1 to 8, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a compound represented by the following formula (b3): (In the formula, B ｈｂ each independently represents a hydrogen atom or a group represented by the following formula (Bz), and at least one B ｈｂ is a group represented by the following formula (Bz). (In the formula, * represents the bonding position.) 10. The curable composition according to any one of claims 1 to 9, wherein the curable component comprises a compound having a vinylphenyl group, and the compound having a vinylphenyl group comprises a polymer having a vinylphenyl group.

11. The curable composition according to any one of claims 1 to 10, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes a polymer having a structural unit represented by formula (Bb) below: (In the formula, X represents an organic group; each B independently represents a group containing a vinylphenyl group; each R independently represents a substituent; l represents an integer of 1 to 5; m represents an integer of 0 to 10; and * represents the bonding position to another atom.) 12. The curable composition according to any one of claims 1 to 11, wherein the curable component includes a compound having a vinylphenyl group, and the compound having a vinylphenyl group includes at least one selected from the group consisting of a polymer represented by the following formula (B3-3) and a polymer represented by the following formula (B3-7): (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5. The benzene ring may each independently have a substituent at a substitutable position. (In the formula, B ｂ each independently represents a group represented by the following formula (Bz), and n represents a number of 3 to 5. The benzene ring may each independently have a substituent at a substitutable position. (In the formula, * represents the bonding position.) 13. The curable composition according to any one of claims 1 to 12, wherein the curable component includes a compound having a vinylbenzyl group, and the compound having a vinylbenzyl group includes a compound represented by the following formula (A): (Wherein, R １ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position to another structure, and a plurality of R １ At least one of R is a vinylbenzyl group; ４ are each independently a monovalent organic group, a halogen atom, a hydrogen atom, or a bonding position to another structure, and R ｘ１ and R ｘ２ are each independently a divalent aliphatic hydrocarbon group or a single bond, Ar is a substituted or unsubstituted biphenylene group or a substituted or unsubstituted phenylene group, and n is an integer of 1 or greater.

14. The curable composition according to any one of claims 1 to 13, wherein the dielectric tangent of the cured product when cured at 175°C for 6 hours is 0.010 or less.

15. The curable composition according to any one of claims 1 to 14, which is used to form a part of a high-frequency device.

16. An electronic component device comprising an electronic component and a cured product of the curable composition according to any one of claims 1 to 15, which seals at least a portion of the electronic component.

17. A high-frequency device comprising a cured product of the curable composition according to any one of claims 1 to 15.

18. A dielectric substrate obtained by curing the curable composition according to any one of claims 1 to 15.

19. A microstrip antenna comprising: a dielectric substrate according to claim 18; a radiating element provided on one surface of said dielectric substrate; and a ground conductor plate provided on the other surface of said dielectric substrate.

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