Curable composition for sealing material, and sealing material

Abstract

One embodiment of the present invention relates to a curable composition for a sealing material, the composition comprising a compound having a vinylphenyl group and an inorganic filler containing alumina.

Description

Curable composition for sealing materials and sealing material

[0001] This disclosure relates to a curable composition for encapsulating materials, encapsulating materials, and electronic component devices.

[0002] Semiconductor devices, including semiconductor elements such as ICs (Integrated Circuits), are used in a variety of electronic devices. In recent years, with advancements in functionality and speed, the amount of heat generated by semiconductor elements has increased, and improved heat dissipation characteristics are required for semiconductor devices. To improve heat dissipation characteristics, it is desirable that the encapsulating material used in semiconductor devices has excellent thermal conductivity, and a method of improving thermal conductivity is known in which inorganic fillers such as aluminum nitride, boron nitride, alumina, and silica are incorporated into the encapsulating material (see, for example, Patent Document 1).

[0003] Japanese Patent Publication No. 2010-24464

[0004] However, increasing the content of inorganic fillers to further improve thermal conductivity sometimes leads to a decrease in curability, resulting in a reduction in the productivity of semiconductor devices. Therefore, this disclosure provides a curable composition for encapsulants that can obtain encapsulants having excellent curability and thermal conductivity. This disclosure also provides an encapsulant having excellent productivity and thermal conductivity, as well as an electronic component device containing the encapsulant.

[0005] The present invention includes, but is not limited to, the following embodiments. One embodiment relates to a curable composition for sealing materials containing a compound having a vinylphenyl group and an inorganic filler containing alumina. Another embodiment relates to a sealing material comprising a cured product obtained using the curable composition for sealing materials. Another embodiment relates to an electronic component device having the sealing material.

[0006] This disclosure provides a curable composition for sealing materials that can produce a sealing material having excellent curability and thermal conductivity. Furthermore, this disclosure provides a sealing material having excellent productivity and thermal conductivity, as well as an electronic component device containing the sealing material.

[0007] Figure 1 is a GPC chart of the vinylphenyl compounds synthesized in the examples.

[0008] Embodiments of the present invention will now be described. The present invention is not limited to the following embodiments. The following embodiments can be implemented individually or in combination. Combinations of multiple embodiments are also included in the present invention.

[0009] In this disclosure, numerical ranges indicated using "~" mean a range that includes the numbers listed before and after "~" as the minimum and maximum values, respectively. In numerical ranges described stepwise in this disclosure, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. The upper or lower limits of numerical ranges described in this disclosure may be replaced with the values ​​shown in the examples. A numerical value may be selected from the upper and lower limits described stepwise in this disclosure to form a stepwise numerical range. The upper and lower limits described in this disclosure may be replaced with the values ​​shown in the examples. In this disclosure, each component may contain multiple types of the corresponding substance. If multiple types of the corresponding substance exist in the composition, the content or amount of each component means the total content or amount of the multiple types of substances present in the composition, unless otherwise specified. In this disclosure, each structure in the polymer may contain multiple types of the corresponding structure. If multiple types of structures corresponding to each structure exist in a polymer, the content or amount of each structure refers to the total content or amount of such multiple types of structures present in the polymer, unless otherwise specified. In this disclosure, particles corresponding to each component may include multiple types of particles. If multiple types of particles corresponding to each component exist in a composition, the particle size of each component refers to the value for a mixture of such multiple types of particles present in the composition, unless otherwise specified.

[0010] <Curable Composition for Sealing Materials> The curable composition for sealing materials contains at least a compound having a vinylphenyl group and an inorganic filler containing alumina. The curable composition for sealing materials may further contain a compound having a vinyl bond. In this disclosure, a compound having a vinyl bond is a compound different from a compound having a vinylphenyl group and is not a compound that falls under the category of a compound having a vinylphenyl group. A compound having a vinyl bond does not have a vinylphenyl group. In this disclosure, the curable composition for sealing materials may be simply referred to as "curable composition". In this disclosure, a compound having a vinylphenyl group may be referred to as "vinylphenyl compound". In this disclosure, a compound having a vinyl bond may be referred to as "vinyl compound".

[0011] [Compounds containing vinylphenyl groups] A vinylphenyl compound is a compound having at least one vinylphenyl group. A vinylphenyl compound may have, for example, 1 to 20, 1 to 15, or 1 to 10 vinylphenyl groups. A vinylphenyl compound may consist of one vinylphenyl compound or may contain two or more vinylphenyl compounds. When a curable composition contains a vinylphenyl compound, the curable composition has excellent curability, and the resulting cured product has excellent thermal conductivity. One reason for this is that even when the curable composition contains alumina, the reaction between the molecules of the vinylphenyl compound and the vinyl compound, if optionally included, proceeds well. If the alumina has functional groups such as hydroxyl groups on its surface, depending on the type of resin component, the reactivity between molecules may decrease due to the influence of the alumina. In contrast, since vinylphenyl compounds and vinyl compounds are less affected by alumina, the reaction proceeds sufficiently, and excellent curability is obtained. Furthermore, the excellent curability results in a higher crosslinking density of the cured product, which improves heat resistance. However, these are speculations, and the present invention is not limited by these speculations.

[0012] The vinylphenyl group can be represented by one of the following formulas. From the viewpoint of obtaining a cured product with low dielectric constant and dielectric loss tangent, vinylphenyl compounds may include compounds having a group represented by formula (p). * indicates the bonding position with other atoms.

[0013] In the total amount of vinylphenyl compound contained in the curable composition, the ratio of the group represented by formula (p), the group represented by formula (m), and the group represented by formula (o) (the molar ratio of the group represented by formula (p): the group represented by formula (m): the group represented by formula (o) is, for example, 40-100:0-60:0-60, 70-90:0:10-30, or 40-60:40-60:0. The larger the ratio of the group represented by formula (p), the lower the dielectric constant and dielectric loss tangent of the cured product tend to be.

[0014] A vinylphenyl compound may be a compound having a vinylphenylmethyl group (also called a "vinylbenzyl group"). In this 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.

[0015] The vinylphenyl compound may be a monomer or polymer that can be radically polymerized. In this disclosure, the monomer may be a compound that does not contain repeating structural units. The polymer may be a compound that contains repeating structural units. 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.

[0016] In some embodiments, the vinylphenyl compound includes a compound having two vinylphenyl groups, and may further include at least one selected from the group consisting of a compound having one vinylphenyl group and a compound having three vinylphenyl groups; or it may include a compound having two vinylphenyl groups, a compound having one vinylphenyl group, and a compound having three vinylphenyl groups. When the vinylphenyl compound is a mixture of two or more compounds, the average number of vinylphenyl groups in the vinylphenyl compound is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6.

[0017] Vinylphenyl compounds may further have aromatic rings. Vinylphenyl compounds may have only one aromatic ring or two or more aromatic rings. The number of carbon atoms in the aromatic ring may be, for example, 2 to 30, 6 to 20, or 9 to 15. The aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocycle. The aromatic ring may be a monocycle or a fused polycycle. Examples of aromatic hydrocarbon rings include benzene, naphthalene, anthracene, tetracene, fluorene, phenanthrene, indene, indane, biphenylene, etc. Examples of aromatic heterocycles include pyridine, pyrazine, quinoline, isoquinoline, acridine, phenanthroline, furan, pyrrole, thiophene, carbazole, oxazole, oxadiazole, thiadiazole, triazole, benzoxazole, benzoxadiazole, benzothiadiazole, benzotriazole, benzothiophene, etc. The aromatic ring may be an aromatic hydrocarbon ring or a fused polycyclic aromatic hydrocarbon ring, from the viewpoint of the dielectric properties of the cured product. From the viewpoint of dielectric constant and dielectric loss tangent, the aromatic ring may be, for example, fluorene or indene; or it may be indene. When the vinylphenyl compound contains indene, there is a tendency to obtain a cured product that exhibits a lower dielectric constant and dielectric loss tangent.

[0018] Aromatic rings, aromatic hydrocarbon rings (examples of aromatic rings), aromatic heterocycles, and fused polycyclic aromatic hydrocarbon rings, as well as the rings specifically mentioned above, may be substituted or unsubstituted. Examples of substituents in the case of substitution include alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, and monovalent groups formed by bonding two or more of these. The number of carbon atoms in alkyl groups and alkenyl groups may be 1 to 18, 2 to 12, or 3 to 6. The number of carbon atoms in aryl groups and heteroaryl groups may be 2 to 30, 6 to 20, or 9 to 15. Examples of the monovalent groups include alkylaryl groups, arylalkyl groups, and alkylarylalkyl groups.

[0019] The vinylphenyl compounds may include, for example, a compound having one aromatic ring and one to three vinylphenyl groups bonded to the aromatic ring directly or via a linking group; a compound having one aromatic hydrocarbon ring and one to three vinylphenyl groups bonded to the aromatic hydrocarbon ring directly or via a linking group; or a compound having one indene ring and one to three vinylphenyl groups bonded to the indene ring directly or via a linking group. In these embodiments, the aromatic ring, aromatic hydrocarbon ring, and indene ring may each be substituted or unsubstituted. Examples of substituents are as described above. The linking group may be, for example, a group selected from the group consisting of alkylene groups (with, for example, 1 to 5 carbon atoms), oxy groups, thio groups, sulfonyl groups, sulfinyl groups, carbonyl groups, carbonyloxy groups, imino groups, and divalent groups formed by the bonding of two or more of these groups. Furthermore, "having one aromatic ring and one to three vinylphenyl groups bonded to the aromatic ring via a linking group" means "having one aromatic ring and one to three 'linking groups bonded to the aromatic ring and vinylphenyl groups bonded to the linking group'."

[0020] The vinylphenyl compound may have, in place of or in conjunction with the aromatic ring, a saturated or unsaturated aliphatic hydrocarbon group, a saturated or unsaturated alicyclic hydrocarbon group, a group containing a heteroatom, etc.

[0021] The weight-average molecular weight (Mw) of the vinylphenyl compound 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 moldability and handling. In this disclosure, the weight-average molecular weight (Mw) refers to the value measured in polystyrene terms by gel permeation chromatography (GPC).

[0022] In some embodiments, the vinylphenyl compound includes a compound represented by the following formula (b1). (In the formula, X ｂ１(where represents an organic group, B independently represents a group containing a vinylphenyl group, l represents an integer from 1 to 5, R independently represents a substituent, and m represents an integer from 0 to 5.)

[0023] Regarding B, "each independently" means, for example, that when l is 2 or more and the compound represented by formula (b1) has multiple B groups, the multiple B groups may be the same "group containing a vinylphenyl group," or some or all of them may be different "groups containing a vinylphenyl group." In this case, "each independently" does not prevent l from being 1, and the compound represented by formula (b1) may be a compound having one "group containing a vinylphenyl group." ｌ The same applies to similar statements.

[0024] The organic group may be a group containing at least one carbon atom, and may be 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 ring groups, and aromatic heterocyclic groups. The organic group may further contain a group containing a heteroatom, or it may not. The organic group may be, for example, an aromatic hydrocarbon ring group or an aromatic heterocyclic group; or it may be an aromatic hydrocarbon ring group. Examples of aromatic hydrocarbon rings in aromatic hydrocarbon ring groups and aromatic heterocyclic rings in aromatic heterocyclic groups are as described above.

[0025] l may be 1 to 3. The vinylphenyl compound may include, for example, a compound in formula (b1) where l is 2, and may further include at least one selected from the group consisting of a compound where l is 1 and a compound where l is 3; or it may include a compound where l is 2, a compound where l is 1, and a compound where l is 3. If the vinylphenyl compound includes multiple compounds represented by formula (b1), the average value of l in the compounds represented by formula (b1) is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6.

[0026] Examples of substituents represented by R include alkyl groups, alkenyl groups, aryl groups, heteroaryl groups, and monovalent groups formed by bonding two or more of these groups. The number of carbon atoms in alkyl and alkenyl groups may be 1 to 18, 2 to 12, or 3 to 6. The number of carbon atoms in aryl and heteroaryl groups may be 2 to 30, 6 to 20, or 9 to 15. Examples of the monovalent group include alkylaryl groups, arylalkyl groups, and alkylarylalkyl groups. m may be 0 to 2, or 0 or 1. When the vinylphenyl compound includes multiple compounds represented by formula (b1), the average value of m in the compounds represented by formula (b1) is, for example, 0.0 to 1.8, 0.0 to 1.6, or 0.0 to 1.4. In some embodiments, the average value of m may be greater than 0.0, 0.1 or more, 0.5 or more, or 1.0 or more.

[0027] When a vinylphenyl compound contains multiple compounds represented by formula (b1), the content of B is, for example, 50 mol% or more, 55 mol% or more, 60 mol% or more, or 70 mol% or more, based on the sum of B and R. The content of B is, for example, 95 mol% or less, 90 mol% or less, or 80 mol% or less. The content of R is, for example, 5 mol% or more, 10 mol% or more, or 20 mol% or more, based on the sum of B and R. The content of R is, for example, 50 mol% or less, 45 mol% or less, 40 mol% or less, or 30 mol% or less.

[0028] When the vinylphenyl compound contains a plurality of compounds represented by the formula (b1), the content percentage of the compound where l + m = 3 is, for example, 70.0% or more, 75.0% or more, or 80.0% or more. The content percentage of the compound where l + m = 3 is, for example, 95.0% or less, 90.0% or less, or 85.0% or less. The content percentage of the compound where l + m = 2 is, for example, 3.0% or more, 3.0% or more, or 10.0% or more. The content percentage of the compound where l + m = 2 is, for example, 25.0% or less, 20.0% or less, or 19.0% or less. The content percentage of the compound where l + m = 1 is, for example, more than 0.0%, 0.1% or more, or 0.5% or more. The content percentage of the compound where l + m = 1 is, for example, 1.2% or less, 1.0% or less, or 0.9% or less. The above content percentages are content percentages based on the compound represented by the formula (b1), and are content percentages (area %) calculated from the peak areas of each compound in the GPC chart. In the present disclosure, the GPC chart can be measured by the method described in the examples.

[0029] In some embodiments, the vinylphenyl compound contains a compound represented by the following formula (b2). When the vinylphenyl compound contains a compound represented by the following formula (b2), there is a tendency to obtain better curability. (In the formula, X ｂ２ represents an aromatic hydrocarbon ring group, B ｐ each independently represents a group represented by the following formula (Ph), L each independently represents a direct bond or a linking group, l represents an integer of 1 to 3, R each independently represents a substituent, and m represents an integer of 0 to 3. (In the formula, * represents the bonding position.))

[0030] Examples of the aromatic hydrocarbon ring in the aromatic hydrocarbon ring group are as described above. X ｂ２ may be, for example, a condensed polycyclic aromatic hydrocarbon ring group.

[0031] Examples of the linking group are as described above. The linking group may be, for example, an alkylene group (having, for example, 1 to 5 carbon atoms), and may be a methylene group. When L is a "direct bond", it means that X ｂ２ and B ｐIt means that they are directly bonded. The same applies to descriptions similar to "L is a direct bond" in the present disclosure.

[0032] The vinylphenyl compound includes, for example, a compound in which l is 2 in the formula (b2), and may further include at least one selected from the group consisting of a compound in which l is 1 and a compound in which l is 3; or may include 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 compound contains a plurality of compounds represented by the formula (b2), the average value of l in the compound represented by the formula (b2) is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6.

[0033] Examples of the substituent represented by R are as listed in the formula (b1). From the viewpoint of dielectric properties, R may be an alkylaryl group, an arylalkyl group, or an alkylarylalkyl group, preferably may be an alkylarylalkyl group, and more preferably may be an alkylphenylmethyl group. m may be 0 to 2, or may be 0 or 1. When the vinylphenyl compound contains a plurality of compounds represented by the formula (b1), the average value of m in the compound represented by the formula (b2) is, for example, 0.0 to 1.8, 0.0 to 1.6, or 0.0 to 1.4. In some embodiments, from the viewpoint of moisture resistance, the average value of m may be more than 0.0, 0.1 or more, 0.5 or more, or 1.0 or more.

[0034] When the vinylphenyl compound contains a plurality of compounds represented by the formula (b2), B ｐ The content of is based on the total of B ｐ and R, and is, for example, 50 mol% or more, 55 mol% or more, 60 mol% or more, or 70 mol% or more. The content of B ｐ is, for example, 95 mol% or less, 90 mol% or less, or 80 mol% or less. The content of R is based on the total of B ｐ and R, and is, for example, 5 mol% or more, 10 mol% or more, or 20 mol% or more. The content of R is, for example, 50 mol% or less, 45 mol% or less, 40 mol% or less, or 30 mol% or less. Examples of the content of the compound where l + m = 3, 2 or 1 are as listed for the compound represented by the formula (b1).

[0035] From the viewpoint of obtaining a hardened product with low dielectric constant and dielectric loss tangent, the group represented by formula (Ph) may include the group represented by formula (p) above.

[0036] In some embodiments, the vinylphenyl compound includes a compound represented by the following formula (b3). When the vinylphenyl compound includes a compound represented by the following formula (b3), better curability is obtained, and furthermore, a lower dielectric constant and dielectric loss tangent tend to be obtained. (In the formula, B ｈｂ Each of these independently represents a hydrogen atom, a group represented by the following formula (Ba), or a group represented by the following formula (Bz), and at least one B ｈｂ This is a group represented by the following formula (Bz). (In the formula, A represents an alkyl group, and * represents a bond position.) (In the formula, * indicates the bonding position.)

[0037] The number of carbon atoms in the alkyl group represented by A is, for example, 1 to 6.

[0038] The vinylphenyl compound includes a compound in which the number of groups represented by formula (Bz) in formula (b3) is 2, and may further include at least one selected from the group consisting of a compound in which the number is 1 and a compound in which the number is 3; or it 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 compound includes multiple compounds represented by formula (b3), the average number of groups represented by formula (Bz) in the compounds represented by formula (b3) is, for example, 1.2 to 2.8, 1.4 to 2.7, or 1.6 to 2.6. In the compound represented by formula (b3), the average number of groups represented by formula (Ba) is, for example, 0.0 to 1.8, 0.0 to 1.6, or 0.0 to 1.4. In some embodiments, the average number of groups represented by formula (Ba) may be greater than 0.0, 0.1 or more, 0.5 or more, or 1.0 or more from the viewpoint of moisture resistance.

[0039] From the viewpoint of obtaining a cured product with low dielectric constant and dielectric loss tangent, the group represented by formula (Bz) may include a group represented by formula (Bz) in which the bond position of the vinyl group to the benzene ring is in the para position relative to the bond position of the methylene group to the benzene ring.

[0040] In some embodiments, the vinylphenyl compound is a compound represented by formula (b3), wherein at least one B ｈｂ The compound may contain a group represented by the formula (Ba).

[0041] When a vinylphenyl compound contains multiple compounds represented by formula (b3), the content of the group represented by formula (Bz) is, for example, 50 mol% or more, 55 mol% or more, 60 mol% or more, or 70 mol% or more, based on the total of the groups represented by formula (Bz) and formula (Ba). The content of the group represented by formula (Bz) is, for example, 95 mol% or less, 90 mol% or less, or 80 mol% or less. The content of the group represented by formula (Ba) is, for example, 5 mol% or more, 10 mol% or more, or 20 mol% or more, based on the total of the groups represented by formula (Bz) and formula (Ba). The content of the group represented by formula (Ba) is, for example, 50 mol% or less, 45 mol% or less, 40 mol% or less, or 30 mol% or less.

[0042] If the vinylphenyl compound contains multiple compounds represented by formula (b3), then B ｈｂ The content of a compound in which all of the groups are independently represented by formula (Ba) or formula (Bz) is, for example, 70.0% or more, 75.0% or more, or 80.0% or more. ｈｂ The content of a compound in which all of the groups are independently represented by formula (Ba) or formula (Bz) is, for example, 95.0% or less, 90.0% or less, or 85.0% or less. ｈｂ The content of the compound in which the two groups are each independently represented by formula (Ba) or formula (Bz) is, for example, 3.0% or more, 3.0% or more, or 10.0% or more. ｈｂ The content of compounds in which the two groups are each independently represented by formula (Ba) or formula (Bz) is, for example, 25.0% or less, 20.0% or less, or 19.0% or less. ｈｂThe content of a compound in which one of the groups is represented by formula (Ba) or formula (Bz) is, for example, greater than 0.0%, 0.1% or more, or 0.5% or more. ｈｂ The content of a compound in which one of the groups is represented by formula (Ba) or formula (Bz) is, for example, 1.2% or less, 1.0% or less, or 0.9% or less. The above content is the content based on the compound represented by formula (b3), and is the content (area %) calculated from the peak area of ​​each compound in the GPC chart.

[0043] The method for synthesizing vinylphenyl compounds is not particularly limited. For example, if the vinylphenyl compound is a compound represented by formula (b2), the method involves reacting an aromatic hydrocarbon ring with styrene having a methyl halide group in the presence of a basic compound, or reacting an aromatic hydrocarbon ring with styrene having a methyl halide group with R having a methyl halide group. R is the R in formula (b2), and for example, if R is an alkylphenylalkyl group, then "R having a methyl halide group" is benzene having a methyl halide group and an alkyl group. When synthesized by these methods, the compound represented by formula (b2) has a methylene group as a linking group. According to this method, a compound having R but not a vinylphenyl group may be produced as a by-product along with the vinylphenyl compound. The curable composition may contain such by-products.

[0044] Examples of styrene having a methyl halide group include o-chloromethylstyrene, m-chloromethylstyrene, and p-chloromethylstyrene, which can be used individually or in combination of two or more. Examples of R having a methyl halide group include α-chloro-o-xylene, α-chloro-m-xylene, and α-chloro-p-xylene, which can be used individually 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 can be carried out under heating and stirring. A polymerization inhibitor (sometimes referred to as "polymerization inhibitor A") may be added to the reaction system. The obtained product may be purified by known methods such as concentration, reprecipitation, and washing, as needed.

[0045] In some embodiments, the vinylphenyl compound includes a vinylphenyl group-containing polymer. Examples of vinylphenyl group-containing polymers include polymers having a hydrocarbon chain skeleton and containing vinylphenyl groups; and polymers having a phenol resin-type skeleton and containing vinylphenyl groups. Examples of polymers having a hydrocarbon chain skeleton include polyolefins, vinyl polymers, acrylic polymers, and polydicyclopentadiene. Examples of phenol resins include novolac-type phenol resins, aralkyl-type phenol resins, dicyclopentadiene-type phenol resins, triphenylmethane-type phenol resins, and resins in which a naphthol structure is included in place of or together with the phenol structure.

[0046] The weight-average molecular weight (Mw) of the vinylphenyl group-containing polymer is, for example, 300 to 50,000, 500 to 30,000, or 1,000 to 10,000, from the viewpoint of moldability and handling. From the viewpoint of improving the fluidity of the curable composition and obtaining good moldability, the weight-average molecular weight (Mw) may be 5,000 or less, or 2,500 or less.

[0047] (Content) The curable composition may contain only one vinylphenyl compound or two or more vinylphenyl compounds. The content of the vinylphenyl compound is, for example, 10% by mass or more and less than 100% by mass, 15 to 98% by mass, or 20 to 95% by mass, based on the mass of the curable composition (excluding the mass of the filler). The content of the vinylphenyl compound may be 75% by mass or less, 55% by mass or less, 35% by mass or less, or 30% by mass or less. When the content of the vinylphenyl compound is 10% by mass or more, the cured product tends to exhibit better curability.

[0048] When a 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 mass of the vinylphenyl compound. The upper limit of the content of the vinylbenzyl compound may be 100% by mass.

[0049] When the curable composition contains a vinyl compound, the total content of the vinylphenyl compound and the vinyl compound is, for example, 70% by mass or more and less than 100% by mass, 80% to 99% by mass, or 90% to 98% by mass, based on the mass of the curable composition (excluding the mass of the filler). When the total content is 70% by mass or more, the cured product tends to exhibit better curability. The total content may also be 75% to 97% by mass, or 80% to 95% by mass.

[0050] When the curable composition contains a vinyl compound, the content of the vinylphenyl compound is, for example, 10 to 90% by mass, 15 to 80% by mass, or 20 to 70% by mass, based on the total mass of the vinylphenyl compound and the vinyl compound. When the content of the vinylphenyl compound is 10% by mass or more, the cured product tends to exhibit better curability. From the viewpoint of obtaining sufficient effects from the vinyl compound, the content of the vinylphenyl compound may be 90% by mass or less, and may also be 60% by mass or less, 50% by mass or less, 45% by mass or less, or 35% by mass or less.

[0051] [Inorganic Filler] The curable composition contains an inorganic filler, including alumina. The inclusion of an inorganic filler in the curable composition can improve the thermal conductivity, strength, and other properties of the cured product. Alumina is a filler that offers an excellent balance of thermal conductivity, stability, and cost. When the curable composition contains alumina, the resulting cured product exhibits superior thermal conductivity. The inorganic filler may contain one type of inorganic filler alone, or two or more types of inorganic fillers. An example of a case containing two or more types of inorganic fillers is when the inorganic fillers differ in their composition, average particle size, shape, or other properties.

[0052] The inorganic filler only needs to contain alumina, and may contain only alumina, or alumina and other inorganic fillers. Examples of alumina include α-alumina, β-alumina, γ-alumina, θ-alumina, etc. From the viewpoint of thermal conductivity and chemical stability, the inorganic filler may contain α-alumina. The inorganic filler may contain only one type of alumina, or two or more types of alumina.

[0053] Other inorganic fillers include silica such as fused silica and crystalline silica, glass, calcium carbonate, zirconium silicate, magnesium oxide, calcium silicate, silicon nitride, aluminum nitride, boron nitride, silicon carbide, industrial diamond, beryllia, zirconia, zircon, fossterite, steatite, spinel, mullite, titania, talc, clay, and mica. Flame-retardant inorganic fillers may also be used. Examples of flame-retardant inorganic fillers include aluminum hydroxide, magnesium hydroxide, composite metal hydroxides such as magnesium-zinc composite hydroxides, and zinc borate.

[0054] Examples of inorganic filler shapes include powder, spheres, and fibers. From the viewpoint of fluidity of the curable composition, mold wear resistance, and protection of semiconductor elements, it is preferable that the inorganic filler contains spherical particles. For example, 70% or more by mass of the particles contained in the inorganic filler may be spherical particles.

[0055] The average particle size of the inorganic filler may be 0.1 μm or larger. From the viewpoint of improving the packing performance of the curable composition, the average particle size of the inorganic filler may be 100 μm or less. The average particle size of the inorganic filler is, for example, 0.1 to 100 μm, 0.5 to 50 μm, 1.0 to 20 μm, or 1.0 to 10 μm. The average particle size of the inorganic filler refers to the average particle size of alumina when alumina is included alone as the inorganic filler, and to the average particle size of the inorganic filler as a whole when alumina and other inorganic fillers are included as the inorganic filler.

[0056] In some embodiments, from the viewpoint of thermal conductivity, the alumina includes alumina with an average particle diameter of 1.0 μm or more and alumina with an average particle diameter of less than 1.0 μm. For example, the alumina may include alumina with an average particle diameter of 1.0 μm to 20 μm and alumina with an average particle diameter of 0.1 μm or more and less than 1.0 μm, or it may include alumina with an average particle diameter of 2.0 μm to 15 μm and alumina with an average particle diameter of 0.1 μm or more and less than 1.0 μm, or it may include alumina particles with an average particle diameter of 3.0 μm to 10 μm and alumina with an average particle diameter of 0.3 μm or more and less than 1.0 μm. The fact that the alumina includes alumina with an average particle diameter of 1.0 μm or more and alumina with an average particle diameter of less than 1.0 μm can be confirmed, for example, from the volume-based particle size distribution (frequency distribution) of the alumina.

[0057] The average particle size and particle size distribution can be determined using a dry particle size analyzer, or using a wet particle size analyzer in the form of a slurry in which an inorganic filler is dispersed in water or an organic solvent. For example, an aqueous slurry with an alumina concentration adjusted to approximately 0.01% by mass is treated in a bath-type ultrasonic cleaner for 5 minutes and measured using a laser diffraction particle size analyzer.

[0058] The inorganic filler content is based on the mass of the curable composition (excluding the mass of the filler), for example, 100 to 2,000 mass%, 250 to 1,500 mass%, or 350 to 800 mass%. When the inorganic filler content is 100 mass% or more, the properties of the cured product, such as thermal conductivity and strength, tend to improve further. When the inorganic filler content is 2,000 mass% or less, the increase in viscosity of the curable composition is suppressed, the fluidity is improved, and the moldability tends to be better. The inorganic filler content is based on the volume of the curable composition, for example, 50 to 90 volume%, 55 to 85 volume%, or 60 to 80 volume%. When the inorganic filler content is 50 volume% or more, the properties of the cured product, such as thermal conductivity and strength, tend to improve further. When the inorganic filler content is 90 volume% or less, the increase in viscosity of the curable composition is suppressed, the fluidity is improved, and the moldability tends to be better.

[0059] The alumina content is, for example, 50% by mass or more, 70% by mass or more, or 90% by mass or more, based on the mass of the inorganic filler. The upper limit of the alumina content may be 100% by mass, based on the mass of the inorganic filler. The alumina content is, for example, 50% by volume or more, 70% by volume or more, or 90% by volume or more, based on the volume of the inorganic filler. The upper limit of the alumina content may be 100% by volume, based on the volume of the inorganic filler. A higher alumina content tends to result in better thermal conductivity.

[0060] When alumina contains both alumina with an average particle diameter of 1.0 μm or more and alumina with an average particle diameter of less than 1.0 μm, the content of alumina with an average particle diameter of 1.0 μm or more is, for example, 50% by mass or more, 70% by mass or more, or 80% by mass or more, based on the mass of alumina. The content of alumina with an average particle diameter of 1.0 μm or more may be less than 100% by mass or 95% by mass or less, based on the mass of alumina. The content of alumina with an average particle diameter of less than 1.0 μm is, for example, 50% by mass or less, 30% by mass or less, or 20% by mass or less, based on the mass of alumina. The content of alumina with an average particle diameter of less than 1.0 μm may be greater than 0% by mass or 5.0% by mass or more, based on the mass of alumina.

[0061] [Compounds containing vinyl bonds] The curable composition may further contain vinyl compounds. The vinyl compound is a compound having at least one vinyl bond (excluding compounds that fall under vinylphenyl compounds and compounds that fall under polymerization inhibitors). The vinyl bond may be a radically polymerizable carbon-carbon unsaturated bond. As an example of a vinyl compound, the vinyl bond may be CH ２ Examples include compounds having a monovalent group represented as =CH-*, compounds having a vinyl bond as a divalent group represented as *-CH=CH-*, or compounds having both the monovalent group and the divalent group. The vinyl compound has, for example, 1 to 20, 1 to 15, or 1 to 10 vinyl bonds. The vinyl compound may consist of one vinyl compound or contain two or more vinyl compounds. The vinyl compound does not have a vinylphenyl group. When the curable composition contains a vinyl compound, good curability is obtained, a high glass transition temperature is obtained, and a cured product with excellent heat resistance can be obtained.

[0062] The vinyl compound may be a monomer or polymer that can be radically polymerized. In some embodiments, the vinyl compound includes a compound having two vinyl bonds. In some embodiments, the vinyl compound includes a compound having three or more vinyl bonds.

[0063] Examples of vinyl compounds include olefin compounds such as ethylene, propylene, butadiene, isoprene, dimethylbutadiene, chloroprene, and 1,3-pentadiene; (meth)acrylic acid ester compounds such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tetra(meth)acrylate, and bisphenol A diglycidyl ether di(meth)acrylate; and carboxyl group-containing vinyl compounds such as (meth)acrylic acid, itaconic acid, maleic acid, and fumaric acid. Examples of compounds include: ester group-containing vinyl compounds such as vinyl acetate and vinyl propionate; halogen-containing vinyl compounds such as vinyl chloride and vinylidene chloride; nitrile group-containing vinyl compounds such as acrylonitrile and methacrylonitrile; amide group-containing vinyl compounds such as acrylamide, methacrylamide, N-methylolacrylamide, and N-methylolmethacrylamide; maleimide compounds such as maleimide, N-phenylmaleimide, and 4,4'-diphenylmethanebismaleimide; and other nitrogen-containing vinyl compounds such as N-vinylpyrrolidone, 1-vinylimidazole, and vinylcarbazole.

[0064] Other examples of vinyl compounds include polymers having a hydrocarbon chain skeleton and vinyl bonds; polymers having a phenol resin-type skeleton and vinyl bonds; and polyamides, polyamide-imides, or polyimides having vinyl bonds.

[0065] (Maleimide Compounds) In some embodiments, the vinyl compound includes a compound having a maleimide group. In this disclosure, a compound having a maleimide group may be referred to as a "maleimide compound." A maleimide compound is a compound having at least one maleimide group. A maleimide compound has, for example, 1 to 20, 1 to 15, or 1 to 10 maleimide groups. A maleimide compound may consist of one maleimide compound or may contain two or more maleimide compounds. When the curable composition contains a maleimide compound, the curability is improved, and consequently, a cured product with less expansion can be obtained.

[0066] The maleimide group can be represented by the following formula. * indicates the bonding position with other atoms.

[0067] In some embodiments, the maleimide compounds include compounds having two maleimide groups. In this disclosure, compounds having two maleimide groups may be referred to as "bismaleimides."

[0068] In some embodiments, the vinyl compound includes a compound represented by the following formula (m1). (In the formula, X ｍ (where represents an organic group, and M represents a maleimide group.)

[0069] The organic group may be a group containing at least one carbon atom, and may be 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 ring groups, and aromatic heterocyclic groups. The organic group may further contain a group containing a heteroatom, or it may not. From the viewpoint of improving the heat resistance of the cured product, the organic group is preferably a group containing at least one selected from the group consisting of aromatic hydrocarbon ring groups and aromatic heterocyclic groups.

[0070] In some embodiments, the vinyl compound includes a polymer having maleimide groups. In this disclosure, a polymer having maleimide groups may be referred to as a "maleimide group-containing polymer." The vinyl compound may include a polymer having two maleimide groups; or it may include a polymer having three or more maleimide groups. Examples of maleimide compounds include polymers having a hydrocarbon chain skeleton and maleimide groups; polymers having a phenol resin type skeleton and maleimide groups; and polyamides, polyamideimides, or polyimides having maleimide groups.

[0071] In some embodiments, the maleimide compound comprises a polymer represented by the following formula (M1). (In the formula, X Ｍ(Each represents either a benzene ring or a naphthalene ring independently; Y represents an organic group independently; M represents a maleimide group independently; L represents a directly bonded or linking group independently; R represents a substituent independently; m represents an integer from 0 to 5 independently; and n represents a number from 2 to 10.)

[0072] The organic group may be a group containing at least one carbon atom, and examples include alkylene groups such as methylene and ethylene groups; cycloalkylene groups such as tetrahydrodicyclopentadiene; arylalkylene groups such as phenylmethylene; and divalent organic groups containing an alkylene group and an arylene group.

[0073] Examples of linking groups include alkylene groups (with, for example, 1 to 5 carbon atoms), oxy groups, thio groups, sulfonyl groups, sulfinyl groups, carbonyl groups, carbonyloxy groups, imino groups, and divalent groups formed by the bonding of two or more of these groups.

[0074] Examples of substituents represented by R include C1-C5 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, t-butyl, and n-pentyl groups. The substituent may be a C1-C3 alkyl group or a methyl group. Each m independently represents, for example, an integer from 0 to 4, an integer from 0 to 2, or 0.

[0075] n is the average value in the polymer represented by formula (M1). n represents, for example, a number between 2 and 8, or a number between 3 and 5.

[0076] In some embodiments, the maleimide compound may include at least one polymer selected from the group consisting of polymers represented by the following formula. When the vinyl compound includes at least one polymer selected from the group consisting of polymers represented by the following formula, excellent heat resistance tends to be easily obtained. (In each formula, M represents a maleimide group, L represents an independent directly bonded or linking group, and n represents a number from 2 to 10. The benzene ring and the naphthalene ring may each independently have substituents at substituted positions.)

[0077] If the benzene ring and naphthalene ring in each formula have substituents, examples of substituents are as given for R in formula (M1). The substituents may be alkyl groups having 1 to 3 carbon atoms, or methyl groups. Alternatively, the benzene ring and naphthalene ring in each formula may be unsubstituted, or may not have substituents other than M-L-*.

[0078] n is the average value in the polymer represented by each formula. n can represent, for example, a number between 2 and 8, or a number between 3 and 5.

[0079] Specific examples of maleimide compounds include novolac-type maleimide compounds such as bis(4-maleimidophenyl)methane, polyphenylmethanemaleimide, bis(4-maleimidophenyl)ether, bis(4-maleimidophenyl)sulfone, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, polyphenylmethanemaleimide, and aralkyl-type maleimide compounds. The maleimide compound includes, for example, at least one selected from the group consisting of 2,2-bis(4-(4-maleimidophenoxy)phenyl)propane, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, and polyphenylmethanemaleimide.

[0080] Commercially available maleimide compounds can be used. Examples of commercially available products include "BMI-80" (2,2-bis[4-(4-maleimidephenoxy)phenyl]propane) manufactured by Yamato Chemical Industries, Ltd., "BMI-1000, BMI-1000H, BMI-1100, BMI-1100H" (all 4,4'-diphenylmethanebismaleimide), and "BMI-2000, BMI-2300" (all phenylmethane) BMI-3000, BMI-3000H (both m-phenylenebismaleimide), BMI-4000 (bisphenol A diphenyl ether bismaleimide), BMI-5100 (3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide), BMI-7000, BMI-7000H (both 4-methyl-1,3-phenylenebismaleimide), BMI-TMH (1,6'-bismaleimide-(2,2,4-trimethyl)hexane); Designer Molecules Inc. Examples include "BMI-2500, BMI-2560, BMI-3000, BMI-5000, BMI-6100" from [company name missing]; "NE-X470S" from DIC Corporation; and "MIR-3000-70MT" from Nippon Kayaku Co., Ltd.

[0081] (Content) When the curable composition contains a vinyl compound, the curable composition may contain only one type of vinyl compound or two or more types of vinyl compounds. When the curable composition contains a vinyl compound, the content of the vinyl compound is, for example, 10 to 90% by mass, 20 to 80% by mass, or 30 to 75% by mass, based on the mass of the curable composition (excluding the mass of the filler). When the content is 10% by mass or more, it is easier to obtain a sufficient effect from the vinyl compound. The content of the vinyl compound may be 40% by mass or more, 50% by mass or more, 55% by mass or more, or 60% by mass or more. When the content of the vinyl compound is 90% by mass or less, it is easier to obtain an improved curability effect from the vinylphenyl compound.

[0082] When the curable composition contains a vinyl compound, the content of the vinyl compound is, for example, 10 to 90% by mass, 20 to 85% by mass, or 30 to 80% by mass, based on the total mass of the vinylphenyl compound and the vinyl compound. When the content is 10% by mass or more, it tends to be easier to obtain a sufficient effect from the vinyl compound. The content of the vinyl compound may be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 65% by mass or more. When the content of the vinyl compound is 90% by mass or less, it tends to be easier to obtain an improved curability effect from the vinylphenyl compound.

[0083] When a vinyl compound contains a maleimide compound, the maleimide compound content 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 vinyl compound. The upper limit of the maleimide compound content may be 100% by mass.

[0084] When a curable composition contains a maleimide compound, it may contain only one maleimide compound or two or more maleimide compounds. When a curable composition contains a maleimide compound, the content of the maleimide compound is, for example, 10 to 90% by mass, 20 to 80% by mass, or 30 to 75% by mass, based on the mass of the curable composition (excluding the mass of the filler). When the maleimide compound content is 10% by mass or more, the cured product tends to exhibit a smaller expansion. Particularly from the viewpoint of reducing the expansion, the maleimide compound content may be 40% by mass or more, 50% by mass or more, 55% by mass or more, or 60% by mass or more. When the maleimide compound content is 90% by mass or less, the effect of improving heat resistance by the vinylphenyl compound tends to be easily obtained.

[0085] When the curable composition contains a maleimide compound, the content of the maleimide compound is, for example, 10 to 90% by mass, 20 to 85% by mass, or 30 to 80% by mass, based on the total mass of the vinylphenyl compound and the maleimide compound. When the maleimide compound content is 10% by mass or more, the cured product tends to exhibit a smaller expansion. Particularly from the viewpoint of reducing the amount of expansion, the maleimide compound content may be 40% by mass or more, 50% by mass or more, 60% by mass or more, or 65% by mass or more. When the maleimide compound content is 90% by mass or less, the effect of improving heat resistance by the vinylphenyl compound tends to be easily obtained.

[0086] When the curable composition contains a maleimide compound, the ratio of the content of vinylphenyl groups to the content of maleimide groups in the curable composition (vinylphenyl groups (mol) / maleimide groups (mol)) may be, for example, 0.05 to 5.0, 0.20 to 3.0, or 0.30 to 1.0, from the viewpoint of dielectric properties, curability, moldability, and conductor adhesion.

[0087] [Optional Components] The curable composition may contain optional components. Examples of optional components include the vinyl compounds mentioned above, radical polymerization initiators, coupling agents, polymerization inhibitors, mold release agents, colorants, ion exchangers, flame retardants, stress relaxants, organic fillers, and various other additives. In addition to the examples below, the curable composition may contain various additives as needed.

[0088] (Radical polymerization initiator) The curable composition may contain a radical polymerization initiator. When the curable composition is used for molding by heating, the radical polymerization initiator may be a thermal radical polymerization initiator that generates free radicals upon 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.

[0089] Examples of organic peroxides include 1,1,3,3-tetramethylbutyl peroxyneodecanoate, di(4-t-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, cumyl peroxyneodecanoate, dilauroyl peroxide, 1-cyclohexyl-1-methylethyl peroxyneodecanoate, t-hexyl peroxyneodecanoate, t-butyl peroxyneodecanoate, and t-butyl peroxy 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-dimethylbutyl peroxyneodecanoate, t-Amyl peroxyneodecanoate, 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 include 5-dimethyl-2,5-di(3-methylbenzoylperoxy)hexane, t-butylperoxy-2-ethylhexyl monocarbonate, t-hexylperoxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, t-butylperoxybenzoate, dibutylperoxytrimethyladipate, t-amylperoxyn-octoate, t-amylperoxyisononanoate, and t-amylperoxybenzoate.

[0090] Examples of azo compounds include 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), 2,2'-azobiisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 4,4'-azobis(4-cyanovaleric acid), and 1,1'-azobis(1-cyclohexanecarbonitride).

[0091] If the curable composition contains a radical polymerization initiator, it may contain only one radical polymerization initiator or two or more radical polymerization initiators. If the curable composition contains a radical polymerization initiator, the content of the radical polymerization initiator may be 0.1 to 5% by mass or 0.2 to 3% by mass, based on the total mass of the vinylphenyl compound and any vinyl compounds included as needed (if the curable composition does not contain a vinyl compound, the content of the vinylphenyl compound; the same applies hereinafter). If the curable composition does not contain a radical polymerization initiator, the content of the radical polymerization initiator may be 0.0% by mass. For example, if the curable composition does not contain a vinyl compound, it may contain a radical polymerization initiator. For example, if the curable composition contains a vinyl compound, it does not need to contain a radical polymerization initiator.

[0092] (Coupling Agents) Curable compositions may contain coupling agents. When a curable composition contains a coupling agent, the adhesion of the cured product, or the adhesion between the resin component (vinylphenyl compound, vinyl compound as needed, etc.) and the inorganic filler tends to improve. Examples of coupling agents include silane coupling agents, titanate coupling agents, aluminum chelate coupling agents, and aluminum / zirconium coupling agents. Silane coupling agents may 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 this disclosure, when a curable composition contains a coupling agent, coupling agents having a vinylphenyl group are excluded from the scope of vinylphenyl compounds described above, and coupling agents having a vinyl group are excluded from the scope of vinyl compounds described above. That is, vinylphenyl compounds and vinyl compounds are compounds other than those that fall under the category of coupling agents. When the curable composition contains a mercapto-silane coupling agent or an amino-silane coupling agent, the adhesion of the cured product tends to improve. When the curable composition contains a vinyl-silane coupling agent or a (meth)acrylic-silane coupling agent, the moldability and strength of the cured product tend to improve.

[0093] 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)ani Nopropyltrimethoxysilane, γ-(N,N-dimethyl)aminopropyltriethoxysilane, 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 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.

[0094] When a curable composition contains a coupling agent, it may contain only one coupling agent or two or more coupling agents. When a curable composition contains an inorganic filler and a coupling agent, the content of the coupling agent is, for example, 0.01 to 10% by mass, 0.05 to 5% by mass, or 0.1 to 2% by mass, based on the mass of the inorganic filler. When the content of the coupling agent is 0.01% by mass or more, the adhesion of the cured product tends to improve. When the content of the coupling agent is 10% by mass or less, the moldability of the cured product tends to improve.

[0095] (Polymerization Inhibitor) The curable composition may contain a polymerization inhibitor. The polymerization inhibitor may be added to the curable composition as at least one selected from the group consisting of polymerization inhibitor A, polymerization inhibitor B described below, and polymerization inhibitor C described below. The polymerization inhibitor may exist in the curable composition in a state bonded with other compounds such as vinylphenyl compounds, or in a decomposed state.

[0096] Examples of polymerization inhibitors include TEMPO compounds, phenothiazine compounds, DPPH compounds, hindered amine compounds, phenol compounds, quinone compounds, and hydroquinone compounds. In some embodiments, from the viewpoint of fluidity and storage stability of the curable composition, the polymerization inhibitor includes a nitrogen-containing compound. In some embodiments, from the viewpoint of fluidity and storage stability of the curable composition, the polymerization inhibitor includes at least a TEMPO compound. In some embodiments, from the viewpoint of fluidity and storage stability of the curable composition, the polymerization inhibitor includes at least a phenothiazine compound.

[0097] Examples of TEMPO compounds include 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (OH-TEMPO), 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl (4-Oxo-TEMPO), N-(3,3,5,5-tetramethyl-4-oxypiperidyl)pyrene-1-carboxamide (Pyrene-TEMPO), 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl radical (MeO-TEMPO), 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxybenzoate (BzO-TEMPO), and 4-acetamido-2,2,6,6-tetramethyl-1-piperidinyl Examples include xy(Ac-TEMPO), bis(2,2,6,6-tetramethyl-1-piperidinyloxy-4-yl) sebacate (bisTEMPO sebacate), 4-(2-hydroxypropoxy-3-(2-hydroxyethoxy))-2,2,6,6-tetramethylpiperidine-1-ol, 4-(3-hydroxypropoxy-2-(2-hydroxyethoxy))-2,2,6,6-tetramethylpiperidine-1-ol, a mixture of 4-(2-hydroxypropoxy-3-(2-hydroxyethoxy))-2,2,6,6-tetramethylpiperidine-1-ol and 4-(3-hydroxypropoxy-2-(2-hydroxyethoxy))-2,2,6,6-tetramethylpiperidine-1-ol (EGG-TEMPO), etc.

[0098] Examples of phenothiazine compounds include phenothiazine, 2-methylphenothiazine, 2-ethylphenothiazine, 2-methoxyphenothiazine, 2-acetylphenothiazine, 2-methylthiophenothiazine, 2-ethylthiophenothiazine, 2-cyanophenothiazine, 2-chlorophenothiazine, 2-bromophenothiazine, 2-trifluoromethylphenothiazine, 3-methoxyphenothiazine, 10-methylphenothiazine, 10-ethylphenothiazine, 10-isopropylphenothiazine, 10-tert-butylphenothiazine, Examples include 10-acetylphenothiazine, 10-phenylphenothiazine, 2,8-dioctylphenothiazine, 2-cyano-8-methoxyphenothiazine, 3,7-dibutylphenothiazine, 3,7-dioctylphenothiazine, 3,7-dicumylphenothiazine, 3,7-dichloro-10-ethylphenothiazine, 3,7-dibromo-10-ethylphenothiazine, 3,7-bis(trifluoromethyl)-10-ethylphenothiazine, bis-(1-dimethylbenzyl)phenothiazine, and bis-(1-methylbenzyl)phenothiazine.

[0099] The curable composition may contain only one polymerization inhibitor, or it may contain two or more polymerization inhibitors. The content of the polymerization inhibitor is, for example, 0.05 to 7.0% by mass, 0.1 to 5.0% by mass, 0.5 to 4.0% by mass, or 1.0 to 3.5% by mass, based on the mass of the curable composition (excluding the mass of the filler). When the content of the polymerization inhibitor is 0.1% by mass or more, the curable composition tends to exhibit better fluidity and the strength of the cured product tends to be higher. The content of the polymerization inhibitor may be 2.0% by mass or more. When the content of the polymerization inhibitor is 5.0% by mass or less, it tends to be easier to maintain good curability.

[0100] When the polymerization inhibitor contains at least one compound selected from the group consisting of TEMPO compounds and phenothiazine compounds, the total content of the at least one 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 polymerization inhibitor. The upper limit of the total content of the at least one compound may be 100% by mass. When the polymerization inhibitor contains the at least one compound, good fluidity tends to be obtained.

[0101] (Release Agent) The curable composition may contain a release agent. When the curable composition contains a release agent, good release properties from the mold during molding are easily obtained. Examples of known release agents include carnauba wax; higher fatty acids such as montanic acid and stearic acid, and higher fatty acid metal salts; ester waxes such as montanic acid esters; and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene.

[0102] When a curable composition contains a release agent, it may contain only one type of release agent or two or more types of release agents. When a curable composition contains a release agent, the release agent content is, for example, 0.01 to 10% by mass, 0.05 to 5% by mass, or 0.1 to 2% by mass, based on the total mass of the vinylphenyl compound and any vinyl compounds included as needed. When the release agent content is 0.01% by mass or more, sufficient release properties tend to be obtained. When the release agent content is 10% by mass or less, better adhesion properties tend to be obtained.

[0103] (Colorants) The curable composition may contain colorants. Examples of known colorants include carbon black, organic dyes, organic pigments, titanium dioxide, red lead, and red iron oxide. The amount of colorant can be appropriately selected depending on the purpose. The colorant may also function as a filler.

[0104] If the curable composition contains a colorant, it may contain only one colorant or two or more colorants. If the curable composition contains a colorant, the colorant content is, for example, 0.01 to 10% by mass or 0.1 to 5% by mass, based on the total mass of the vinylphenyl compound and any vinyl compounds included as needed.

[0105] (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 electronic components tend to improve. Examples of ion exchangers include hydrotalcite compounds; and hydrated 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 contain only one type of ion exchanger, or it may contain two or more types of ion exchangers.

[0106] (Flame retardant) The curable composition may contain a flame retardant. Examples of flame retardants include organic or inorganic compounds containing halogen atoms, antimony atoms, nitrogen atoms, or phosphorus atoms, and metal hydroxides. The curable composition may contain only one type of flame retardant, or it may contain two or more types of flame retardants.

[0107] (Stress Relief Agents) Curable compositions may contain stress relief agents. When a curable composition contains a stress relief agent, it tends to reduce warping deformation and cracking of electronic components. Examples of stress relief agents include silicone oil; thermoplastic elastomers such as silicone-based, styrene-based, olefin-based, urethane-based, polyester-based, polyether-based, polyamide-based, and polybutadiene-based; 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 vinylphenyl compounds or compounds that fall under vinyl compounds). When a curable composition contains a stress relief agent, it may contain only one type of stress relief agent or two or more types of stress relief agents. Commercially available flexibility-imparting agents can be used as stress relief agents.

[0108] [Applications, etc.] The curable composition can be cured by applying heat, light, or both. The cured product is used as a encapsulant. The curable composition may be a thermosetting composition. Because encapsulants containing cured products obtained using the curable composition have good thermal conductivity, they can be used in components or products that require high heat dissipation characteristics. Examples of components or products that require high heat dissipation characteristics include circuit boards, electronic components, semiconductor devices, and semiconductor modules. The encapsulant may be, for example, for use in electronic components, semiconductor devices, or semiconductor modules.

[0109] Generally, epoxy resin compositions known as curable compositions may contain residual chlorine derived from epichlorohydrin, the raw material for epoxy resin. Furthermore, epoxy resin compositions may contain curing accelerators such as imidazole-based or phosphorus-based agents to improve curability. When an epoxy resin composition contains both, in a high-humidity environment, chloride ions are easily released from chlorine-containing compounds due to the action of the curing accelerator. Also, generally, when an epoxy resin composition contains alumina particles, there is a tendency to increase the amount of curing accelerator used to obtain good curability. Increasing the content of the curing accelerator to improve reactivity in the presence of alumina tends to increase the amount of chloride ions. In contrast, vinylphenyl compounds and vinyl compounds, if included as needed, do not require these curing accelerators, thus preventing the release of chloride ions. Furthermore, in the reaction of vinylphenyl compounds and vinyl compounds, hydroxyl groups are not generated, allowing for a low water absorption rate of the cured product. For these reasons, encapsulants containing cured products can be used in parts or products requiring high moisture resistance.

[0110] The method for producing the curable composition is not particularly limited. For example, a method can be used in which predetermined amounts of components are thoroughly mixed using a mixer or the like, then melt-kneaded, cooled, and pulverized. For melt-kneading, kneaders such as twin-screw kneaders, rolls such as mixing rolls, and extruders such as extruders can be used. The melt-kneading temperature is, for example, 70 to 140°C or 80 to 130°C. The curable composition can be produced, for example, by the production method according to the embodiments described later.

[0111] The curable composition may be solid at room temperature and pressure (for example, 25°C and atmospheric pressure). The shape of the solid curable composition is not particularly limited and may be in the form of powder, granules, tablets, etc. In the solid curable composition, the solvent content may be, for example, 5.00% by mass or less, 1.00% by mass or less, 0.50% by mass or less, or 0.10% by mass or less.

[0112] <Method for Manufacturing Curable Compositions> The method for manufacturing curable compositions is not particularly limited. For example, if the curable composition does not contain a solvent, one method is to mix a predetermined amount of vinylphenyl compound with an inorganic filler containing alumina and any other component, then melt-knead, cool, and pulverize the mixture. For melt-kneading, kneaders such as twin-screw kneaders, rolls such as mixing rolls, and extruders such as extruders can be used. The melt-kneading temperature is, for example, 70 to 140°C or 80 to 130°C.

[0113] For example, a method for producing a curable composition includes mixing liquid A containing a compound having a vinylphenyl group and a solvent with polymerization inhibitor B to obtain liquid B, removing the solvent from liquid B to obtain a mixture containing the compound having a vinylphenyl group and the polymerization inhibitor B; and mixing the mixture with polymerization inhibitor C to obtain a curable composition. According to this production method, a curable composition with high fluidity can be produced, and a cured product with excellent moldability can be obtained.

[0114] <Sealing Material> In some embodiments, the sealing material includes a cured product obtained using the curable composition of the above embodiment. The sealing material can be used to seal electronic components, electronic component devices, semiconductor elements, semiconductor devices, etc. The cured product can be produced, for example, by molding the curable composition and heating the resulting molded product. The heating conditions are, for example, 150 to 180°C for 2 to 16 hours.

[0115] <Electronic Component Device> In some embodiments, the electronic component device has the sealing material of the above embodiment. The electronic component device includes, for example, an electronic component and the sealing material of the above embodiment that seals at least a portion of the electronic component. The electronic component device may be, for example, an electronic component module having a plurality of items selected from the group consisting of electronic components and electronic component devices, and the sealing material of the above embodiment that seals at least a portion of the plurality.

[0116] 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; and connectors, support members, terminals, and switches. Examples of electronic component devices include electronic component devices having the aforementioned electronic components; and modules having either or both of the aforementioned electronic components and / or the aforementioned electronic component device. Electronic component devices may have support members. Examples of support members include lead frames, pre-wired tape carriers, wiring boards, glass, silicon wafers, and organic substrates.

[0117] A semiconductor device may include, for example, a semiconductor element and a sealing material according to the above embodiment that seals at least a portion of the semiconductor element. A semiconductor device may be, for example, a semiconductor module that includes a plurality of semiconductor elements and semiconductor devices selected from the group and a sealing material according to the above embodiment that seals at least a portion of the plurality.

[0118] Examples of semiconductor devices include diodes, transistors, thyristors, power semiconductor devices, photoelectric conversion devices, sensors, ICs (integrated circuits), and memory. Semiconductor devices may be in known package forms, such as through-hole packages and surface-mount packages. Examples of surface-mount packages include lead frame type and bump type. Specific examples include resin-encapsulated ICs (Integrated ICs) such as SIP (Single Inline Package), DIP (Dual Inline Package), PGA (Pin Grid Array), PLCC (Plastic Leaded Chip Carrier), QFP (Quad Flat Package), SOP (Small Outline Package), SOJ (Small Outline J-Lead Package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package). Examples include Circuit, TCP (Tape Carrier Package), COB (Chip On Board), BGA (Ball Grid Array), and CSP (Chip Size Package). Furthermore, specific examples include MCM (Multi-Chip Module) and other MCP (Multi-Chip Package), as well as hybrid ICs.

[0119] Resin-encapsulated ICs have a structure in which, for example, semiconductor elements are fixed on a lead frame, and the terminal portion of the semiconductor element, such as a bonding pad, is connected to the lead portion by wire bonding, bumps, etc., and then encapsulated by transfer molding, etc., using a curable composition. TCPs have a structure in which semiconductor elements connected to a tape carrier by bumps are encapsulated with a curable composition. COBs have a structure in which semiconductor elements connected to wiring formed on a support member by wire bonding, flip-chip bonding, solder, etc., are encapsulated with a curable composition. BGAs, CSPs, and MCPs have a structure in which, for example, semiconductor elements are mounted on the surface of a support member having terminals for connecting to a wiring board formed on the back surface, and the semiconductor elements are connected to wiring formed on the support member by bumps or wire bonding, and then the semiconductor elements are encapsulated with a curable composition. MCMs have a structure in which multiple semiconductor elements connected to wiring formed on a support member by wire bonding, flip-chip bonding, solder, etc., are encapsulated with a curable composition.

[0120] For example, a method for manufacturing an electronic component device includes arranging the electronic component on a support member and sealing at least a portion of the electronic component using the curable composition of the above embodiment. For example, methods for sealing an electronic component or electronic component device include transfer molding, compression molding, and injection molding. By using a curable composition with excellent curability, mold release is improved, and productivity can be increased. For example, this can be carried out under conditions of a mold temperature of 130 to 180°C, a molding pressure of 6 to 10 MPa, and a molding time of 60 to 120 seconds. For example, heating conditions for post-curing are 150 to 180°C for 2 to 16 hours.

[0121] <Examples of Embodiments> Examples of embodiments are given below. The present invention is not limited to the following embodiments. (1) A curable composition for sealing materials containing a compound having a vinylphenyl group and an inorganic filler containing alumina. (2) The curable composition for sealing materials according to (1), wherein the alumina comprises alumina with an average particle diameter of 1.0 μm or more and alumina with an average particle diameter of less than 1.0 μm. (3) The curable composition for sealing materials according to (1) or (2), wherein the compound having a vinylphenyl group comprises a compound represented by formula (b3). (4) The compound having a vinylphenyl group is a compound represented by formula (b3), wherein at least one B ｈｂ (1) to (3) above, a curable composition for sealing materials according to any one of the above, comprising a compound in which is a group represented by the formula (Ba). (5) A curable composition for sealing materials according to any one of the above, comprising a compound having a maleimide group. (6) A sealing material comprising a cured product obtained using the curable composition for sealing materials according to any one of the above, (1) to (5). (7) An electronic component device comprising the sealing material according to (6). The disclosure of this application is related to the subject matter described in Japanese Patent Application No. 2025-017766, filed on 5 February 2025, all of which are incorporated herein by reference.

[0122] Embodiments of the present invention will be specifically described by reference to examples. Embodiments of the present invention are not limited to the following examples.

[0123] <Examples 1 and 2> [Synthesis of vinylphenyl compounds] In a 500 mL reaction vessel equipped with a stirrer, thermometer, reflux tubing, and nitrogen inlet, indene, chloromethylstyrene, tetra-n-butylammonium bromide as a phase transfer catalyst, phenothiazine as a polymerization inhibitor, and toluene as a solvent were added, and the mixture was heated and stirred at 40°C while blowing in nitrogen at a flow rate of 50 mL / min. Then, an aqueous sodium hydroxide solution (48% by mass) was added, and the reaction was carried out at 70°C. １ After confirming the disappearance of chloromethylstyrene by H-NMR, α-chloro-p-xylene was added and the reaction was further carried out at 70°C. １The reaction was terminated after confirming the disappearance of α-chloro-p-xylene by 1H-NMR. Nitrogen was continuously blown in during the reaction. The resulting reaction mixture was cooled to room temperature (25°C), neutralized with a 10% hydrochloric acid aqueous solution, and then washed twice with pure water. After removing a portion of the toluene by vacuum distillation, the resulting viscous liquid was washed with methanol to obtain a vinylphenyl compound solution with a solid content of 60% by mass. The amounts of each compound used are shown in Table 1.

[0124] Next, 100.0 parts by mass of a vinylphenyl compound solution (solvent: toluene, solids content: 60% by mass) and 0.2 parts by mass of bisTEMPO sebacate were added to a container and stirred at room temperature (25°C) for 1 hour. The mixture obtained after stirring was placed in a metal tray and left to stand in a vacuum dryer at a pressure of 0.1 MPa or less and a temperature of 70°C for 5 hours to remove the solvent and obtain the vinylphenyl compound.

[0125] Using a nuclear magnetic resonance spectrometer (JEOL RESONANCE "ECX400II"), vinylphenyl compounds １ H-NMR spectrum (400 MHz, CDCl) ３ The following was measured: A shift or disappearance of the peak of the starting compound was observed, confirming that a reaction occurred in which a vinylbenzyl group was bonded to one of the 1st to 3rd positions of the indene ring, and a methylbenzyl group was bonded to one of the 1st to 3rd positions of the indene ring.

[0126] [Calculation of the composition of vinylphenyl compounds] The composition of vinylphenyl compounds was calculated from the area ratio of the peaks using GPC charts measured under the following conditions. The GPC chart of the mixture is shown in Figure 1. The calculation results are shown in Table 1.

[0127] Instrument: High-speed GPC instrument HLC-8320GPC (Tosoh Corporation) Detector: Ultraviolet absorption detector UV-8320 (Tosoh Corporation) Columns: Guard column; TSKgel guardcolumn Super(HZ)-M+ Column; TSKgel SuperMultipore HZ-M (2), Reference column; TSKgel SuperH-RC (2) (all Tosoh Corporation) Column size: 4.6 × 20 mm (guard column), 4.6 × 150 mm (column), 6.0 × 150 mm (reference column) Eluent: Tetrahydrofuran Sample concentration: 1 mg / 1 mL Injection volume: 2 μL Flow rate: 0.35 mL / min Measurement temperature: 40°C

[0128]

[0129] The indene, chloromethylstyrene, and compounds (1) to (3) listed in Table 1 are as follows: • Indene molecular weight: 116.2 - Chloromethylstyrene: AGC Seimi Chemical Co., Ltd. "CMS-P", a mixture of m-isomer and p-isomer, m-isomer content 50% by mass, p-isomer content 50% by mass - Compound (1): A compound having an indene ring and one "vinylbenzyl group or methylbenzyl group" bonded to the indene ring - Compound (2): A compound having an indene ring and two "vinylbenzyl groups or methylbenzyl groups" bonded to the indene ring - Compound (3): A compound having an indene ring and three "vinylbenzyl groups or methylbenzyl groups" bonded to the indene ring

[0130] [Preparation of Curable Composition] A vinylphenyl compound and the compounds listed in Table 2 were premixed (dry blended), then kneaded in a twin-screw kneader (kneading temperature 90-120°C), the kneaded material was cooled and pulverized to produce a powdered curable composition.

[0131] [Preparation of Cured Products] Cured products were prepared using a curable composition, and their thermal hardness, thermal conductivity, etc., were measured using the following method. The measurement results are shown in Table 2.

[0132] (Hardness under heat) A curable composition was molded using a transfer molding machine (Techno Marushichi Co., Ltd.) under the following conditions: mold temperature 175°C, molding time 120 seconds, and molding pressure 6.9 MPa, to obtain a disc-shaped molded product with a diameter of 50 mm and a thickness of 3 mm. Immediately after molding, the hardness of the molded product was measured using a Shore D type hardness tester (Polymer Instruments Co., Ltd., Asker, Type D durometer).

[0133] (Thermal Conductivity) Using a curable composition, a molded product measuring 1.1 cm square × 1.1 mm thick was obtained using a vacuum hand press molding machine under the following conditions: mold temperature 175°C to 180°C, molding pressure 7.0 MPa, and curing time 600 seconds. The thermal diffusivity in the thickness direction of the obtained molded product was measured. The thermal diffusivity was measured using the laser flash method (NETZSCH, apparatus: LFA447 nanoflash). Pulsed light irradiation was performed under the conditions of pulse width 0.31 (ms) and applied voltage 247 V. The measurement was performed at an ambient temperature of 25°C ± 1°C. The density of the molded product was measured using an electronic hydrometer (SD-200L, Alpha Mirage Co., Ltd.). Next, the value of thermal conductivity was obtained by multiplying the specific heat and density by the thermal diffusivity using equation (1). λ=α×Cp×ρ...Equation (1) (In Equation (1), λ is thermal conductivity (W / (m・K)), α is thermal diffusivity (m ２ ρ is density (d: kg / m³), Cp is specific heat (J / (kg·K)), and ρ is density (d: kg / m³). ３ ) These are shown respectively.

[0134] (Evaluation of ionic impurities) Using a curable composition, a molded product was obtained by molding in a transfer molding machine (Techno Marushichi Co., Ltd.) under the conditions of a mold temperature of 175°C, a molding pressure of 6.9 MPa, and a molding time of 90 seconds. The obtained molded product was heated at 175°C for 5 hours to cure it and obtain a cured product. The cured product was finely pulverized, and 5 g of the pulverized product was placed in an extraction jig (Uniseal, manufactured by Acom) together with 50 mL of distilled water, and extraction was performed in a constant temperature bath at 121°C for 20 hours. The obtained extract was filtered and used as the test solution. The chloride ion concentration (Cl) was measured using the test solution. － The following measurements were taken. An ion chromatograph (Metrohm Japan Co., Ltd., Model AA-6200) was used for the measurements.

[0135] (Water Absorption Rate) Using a curable composition, a disc-shaped molded product (50 mm in diameter x 3 mm in thickness) was obtained using a transfer molding machine (Techno Marushichi Co., Ltd.) under the following conditions: mold temperature 175°C, molding pressure 6.9 MPa, and molding time 90 seconds. The obtained molded product was heated at 175°C for 6 hours to cure it and obtain a cured product. Using a pressure cooker test apparatus (Hirayama Seisakusho Co., Ltd.), the cured product was subjected to a pressure cooker treatment for 20 hours under the conditions of pressure 2 atm (0.2 MPa), temperature 121°C, and relative humidity 100% RH. The mass of the cured product was measured before and after the pressure cooker treatment, and the water absorption rate (mass %) was calculated using the following formula: Water absorption rate (mass %) = ((mass after treatment - mass before treatment) / mass before treatment) × 100

[0136] (Glass Transition Temperature) Using a curable composition, a molded product of 4 mm × 4 mm × 20 mm was obtained using a transfer molding machine (Techno Marushichi Co., Ltd.) under the conditions of a mold temperature of 175°C, a molding time of 90 seconds, and a molding pressure of 6.9 MPa. The obtained molded product was cured at 175°C for 5 hours to obtain a cured product. Thermomechanical analysis of the cured product was performed using a thermomechanical analyzer (TA Instruments "TMA450"), and a TMA curve was created. The measurement temperature range was 30 to 260°C, and the heating rate was 10°C / min. In the TMA curve, the temperature corresponding to the intersection of the line extending from the linear portion of the low-temperature region and the line extending from the linear portion of the high-temperature region was defined as the glass transition temperature Tg (°C).

[0137] (Linear thermal expansion coefficient (thermal expansion rate)) Using a curable composition, a molded product of 4 mm × 4 mm × 20 mm was obtained using a transfer molding machine (Techno Marushichi Co., Ltd.) under the conditions of a mold temperature of 175°C, a molding time of 90 seconds, and a molding pressure of 6.9 MPa. The obtained molded product was cured at 175°C for 5 hours to obtain a cured product. Thermomechanical analysis of the cured product was performed using a thermomechanical analyzer (TA Instruments "TMA450"), and a TMA curve was created. The measurement temperature range was 30 to 260°C, and the heating rate was 10°C / min. The slope of the tangent line between 40°C and 80°C was defined as the thermal expansion coefficient α1, and the slope of the tangent line between 220°C and 260°C was defined as α2.

[0138] <Comparative Examples 1 and 2> After pre-mixing (dry blending) the compounds listed in Table 2, the mixture was kneaded in a twin-screw kneader, cooled, and pulverized to produce a powdered curable composition. The hot hardness, thermal conductivity, etc., were measured using the curable composition in the same manner as in the examples. The measurement results are shown in Table 2.

[0139]

[0140] The compounds listed in Table 2 are as follows. In Table 2, the unit for each compound is "parts by mass". The average particle size of the inorganic filler was measured by the method described above. The alumina content (volume %) is the ratio of the volume of alumina to the volume of the curable composition. In Table 2, "-" means that the component is not included.

[0141] (Vinylphenyl Compounds) ・Vinylbenzyl Compound: Compound obtained in [Synthesis of Vinylphenyl Compounds] (Vinyl Compounds) ・Maleimide Compound: Polyphenylmethanemaleimide, Yamato Chemical Industries, Ltd. "BMI-2300" (Epoxy Resins) ・A1: Triphenylmethane type epoxy resin, Nippon Kayaku Co., Ltd. "EPPN-501HY" ・A2: Bisphenol type epoxy resin, Nippon Steel & Sumitomo Metal Chemical Co., Ltd. "YSLV-80XY" ・A3: Biphenyl type epoxy resin, Mitsubishi Chemical Corporation "YX-4000" (Phenol Resins) ・Triphenylmethane type phenol resin, Air Water Inc. "HE910-09" (Inorganic Fillers) ・B1: Aluminafila, spherical, average particle size 0.7 μm ・B2: Aluminafila, spherical, average particle size 5.7 μm (Other Components) • Curing accelerator: Adduct of triphenylphosphine and p-benzoquinone; Coupling agent: N-phenyl-3-aminopropyltrimethoxysilane, Shin-Etsu Chemical Co., Ltd. "KBM-573" • Release agent: Montanate ester wax, Clariant Japan Co., Ltd. "HW-E" • Coloring agent: Carbon black, Mitsubishi Chemical Corporation "MA600MJ" • Polymerization inhibitor: 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (OH-TEMPO), Hakuto Co., Ltd. "PS-7300P"

Claims

1. A curable composition for sealing materials, comprising a compound having a vinylphenyl group and an inorganic filler containing alumina.

2. The curable composition for sealing material according to claim 1, wherein the alumina comprises alumina with an average particle diameter of 1.0 μm or more and alumina with an average particle diameter of less than 1.0 μm.

3. The curable composition for a sealing material according to claim 1 or 2, wherein the compound having a vinylphenyl group contains a compound represented by the following formula (b3). (In the formula, B ｈｂ each independently represents a hydrogen atom, a group represented by the following formula (Ba), 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, A represents an alkyl group, and * represents a bonding position.) (In the formula, * represents a bonding position.)) 4. The compound having a vinylphenyl group is a compound represented by formula (b3), and at least one B ｈｂ The curable composition for sealing materials according to claim 3, comprising a compound in which the group is represented by the formula (Ba).

5. The curable composition for sealing materials according to any one of claims 1 to 4, further comprising a compound having a maleimide group.

6. A sealing material comprising a cured product obtained using the curable composition for sealing materials described in any one of claims 1 to 5.

7. An electronic component device comprising the sealing material described in claim 6.

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