Resin composition, and prepreg, resin-coated film, resin-coated metal foil, metal-clad laminate, and wiring board each obtained using same

Abstract

One aspect of the present invention relates to a resin composition which comprises a maleimide compound (A) that has an indane structure in the molecule, a hydrocarbon-based compound (B) that has a carbon-carbon unsaturated double bond, a styrene-based polymer (C) that is solid at 25°C, and a silica filler (D), wherein, in the particle size distribution of the silica filler (D), when the volume-based cumulative 10% particle diameter is D10, the volume-based cumulative 50% particle diameter is D50, and the volume-based cumulative 90% particle diameter is D90, then the ratio V (D10 / D50) of D10 to D50 is 0.55 or more, and the ratio W (D50 / D90) of D50 to D90 is 0.60 or more.

Description

Resin composition, and prepreg, resin-coated film, resin-coated metal foil, metal-clad laminate, and wiring board using the same

[0001] The present invention relates to a resin composition, and to a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board using the same.

[0002] In recent years, with the increase in the amount of information processed in various electronic devices, there has been rapid progress in packaging technologies, such as higher integration of semiconductor devices, higher density wiring, and multi-layering. Therefore, substrate materials for constituting the base material of wiring boards used in various electronic devices are required to have low dielectric constants and dielectric loss tangents in order to increase signal transmission speeds and reduce loss during signal transmission.

[0003] In particular, in recent years, the boundaries between printed wiring boards and semiconductor package substrates have been disappearing, as exemplified by substrate-like printed wiring boards (SLPs). As a result, with the recent trend toward smaller electronic devices and higher performance, and the dramatic increase in information communication speeds, both types of substrates are required to be compatible with high frequencies, have excellent heat resistance, and have low thermal expansion.

[0004] Maleimide resin is used as a material for such substrates because it has high heat resistance, and maleimide, which has a low dielectric constant and low dielectric dissipation factor, has been proposed to achieve low transmission loss at high frequencies.

[0005] For example, Patent Document 1 discloses a resin composition containing a maleimide compound having an indane structure and a styrene-based polymer, and Patent Document 2 discloses a resin composition containing a maleimide compound having an indane structure and a hydrocarbon-based compound.

[0006] The resin compositions containing the maleimide compounds described in Patent Documents 1 and 2 are said to have excellent low dielectric properties, high Tg, and can also suppress the coefficient of thermal expansion. Furthermore, the resin composition described in Patent Document 1 is reported to have excellent adhesion. However, it has been found that the resin compositions described in these documents have problems with moldability.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a resin composition that, when cured, has low dielectric properties, a low coefficient of thermal expansion, and a high glass transition temperature (Tg), while also exhibiting excellent adhesion (peel strength) and moldability. It is also an object of the present invention to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that use the resin composition.

[0008] International Publication No. WO 2022 / 054864 International Publication No. WO 2022 / 244723

[0009] A resin composition according to one embodiment of the present invention comprises a maleimide compound (A) having an indane structure in the molecule, a hydrocarbon compound (B) having a carbon-carbon unsaturated double bond, a styrene-based polymer (C) that is solid at 25°C, and a silica filler (D), wherein in the particle size distribution of the silica filler (D), when D10 is the volume-based cumulative 10% particle diameter, D50 is the volume-based cumulative 50% particle diameter, and D90 is the volume-based cumulative 90% particle diameter, the ratio V(D10 / D50) of D10 to D50 is 0.55 or more, and the ratio W(D50 / D90) of D50 to D90 is 0.60 or more.

[0010] FIG. 1 is a schematic cross-sectional view showing the configuration of a prepreg according to one embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing the configuration of a metal-clad laminate according to one embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing the configuration of a wiring board according to one embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing the configuration of a resin-coated metal foil according to one embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing the configuration of a resin-coated film according to one embodiment of the present invention. FIG. 6 is a photograph showing a "passed example (no blur)" (bottom) and a "failed example (with blur)" (top) in the formability evaluation of the examples.

[0011] (Resin Composition) A resin composition according to an embodiment of the present invention (hereinafter also simply referred to as a resin composition) includes a maleimide compound (A) having an indane structure in the molecule, a hydrocarbon compound (B) having a carbon-carbon unsaturated double bond, a styrene-based polymer (C) that is solid at 25° C., and a silica filler (D). In addition, in the particle size distribution of the silica filler (D), when the cumulative 10% particle diameter on a volume basis is D10, the cumulative 50% particle diameter on a volume basis is D50, and the cumulative 90% particle diameter on a volume basis is D90, the ratio V(D10 / D50) of D10 to D50 is 0.55 or more, and the ratio W(D50 / D90) of D50 to D90 is 0.60 or more.

[0012] The resin composition of this embodiment contains a maleimide compound (A) having an indane structure in the molecule, a hydrocarbon compound (B) having a carbon-carbon unsaturated double bond, and a styrene-based polymer (C) that is solid at 25°C. This allows the cured product of the resin composition to have low dielectric properties, a low coefficient of thermal expansion, and excellent adhesion, and also achieve a high Tg. Furthermore, since the silica filler (D) has the above-described structure, the resin composition of this embodiment also has excellent moldability. Therefore, the resin composition of this embodiment is extremely useful for industrial applications. Furthermore, by using this resin composition, it is possible to provide prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards that have excellent properties.

[0013] Each component of the resin composition according to this embodiment will be specifically described below.

[0014] <Maleimide Compound (A)> The maleimide compound (A) that can be used in this embodiment is not particularly limited as long as it is a maleimide compound having an indane structure in the molecule. By including such a maleimide compound (A), the resin composition of this embodiment can have, in a cured product thereof, not only low dielectric properties but also excellent adhesion, a high Tg, and a low thermal expansion coefficient.

[0015] Examples of the indane structure include a divalent group formed by removing two hydrogen atoms from indane or an indane substituted with a substituent, and more specifically, a structure represented by the following formula (1) is included.

[0016] In formula (1), each Rb is independent. That is, each Rb may be the same group or different groups. For example, when r is 2 or 3, two or three Rb's bonded to the same benzene ring may be the same group or different groups. Rb represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group (alkoxy group) having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group (thiol group). r represents an integer of 0 to 3.

[0017] The maleimide compound (A) of this embodiment also has a maleimide group in the molecule. Examples of the maleimide compound (A) of this embodiment include maleimide compounds having a structure represented by the above formula (1) in the molecule, and more specifically, maleimide compounds (A1) having a structure represented by the following formula (2) in the molecule.

[0018] In formula (2), each Ra is independent. That is, each Ra may be the same group or different groups. For example, when q is 2 to 4, 2 to 4 Ra bonded to the same benzene ring may be the same group or different groups. Ra represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. Rb's are the same as Rb's in formula (1), and each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. q represents 0 to 4. r represents 0 to 3. n represents 0.95 to 10.

[0019] r is the average value of the degree of substitution of Rb, and a smaller value is preferable, specifically 0. That is, in the benzene ring to which Rb can be bonded, a hydrogen atom is preferably bonded at the position to which Rb can be bonded. Maleimide compounds (A) having such an r are easy to synthesize. This is thought to be due to reduced steric hindrance and increased electron density in the aromatic ring. Furthermore, when r is 1 to 3, Rb is preferably at least one selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms. Furthermore, Ra is preferably at least one selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms. By using an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms, the compound is more soluble in solvents and can suppress a decrease in the reactivity of the maleimide group, resulting in a suitable cured product. This is thought to be due to a decrease in planarity in the vicinity of the maleimide group, a decrease in crystallinity, and the like.

[0020] Specific examples of the groups represented by Ra and Rb include the following groups.

[0021] The alkyl group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0022] The alkyloxy group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include a methyloxy group, an ethyloxy group, a propyloxy group, a hexyloxy group, and a decyloxy group.

[0023] The alkylthio group having 1 to 10 carbon atoms is not particularly limited, and examples thereof include a methylthio group, an ethylthio group, a propylthio group, a hexylthio group, and a decylthio group.

[0024] The aryl group having 6 to 10 carbon atoms is not particularly limited, and examples thereof include a phenyl group and a naphthyl group.

[0025] The aryloxy group having 6 to 10 carbon atoms is not particularly limited, and examples thereof include a phenyloxy group and a naphthyloxy group.

[0026] The arylthio group having 6 to 10 carbon atoms is not particularly limited, and examples thereof include a phenylthio group and a naphthylthio group.

[0027] The cycloalkyl group having 3 to 10 carbon atoms is not particularly limited, and examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclohexyl group, and a cyclooctyl group.

[0028] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0029] q is the average value of the degree of substitution of Ra, and is preferably 2 to 3, and more preferably 2. Maleimide compound (A) having such a q is easy to synthesize. This is thought to be because, particularly when q is 2, steric hindrance is reduced and the electron density of the aromatic ring is increased.

[0030] n is the average number of repeats, and as described above, is 0.95 to 10, preferably 0.98 to 8, more preferably 1 to 7, and even more preferably 1.1 to 6. In the maleimide compound having the structure represented by formula (1) in the molecule and the maleimide compound (A1) represented by formula (2), the content of the maleimide compound in which n, the average number of repeats (degree of polymerization), is 0, is preferably 32 mass% or less based on the total amount of the maleimide compound (A).

[0031] The maleimide compound (A) preferably has a molecular weight distribution (Mw / Mn) measured by GPC of 1 to 4, more preferably 1.1 to 3.8, even more preferably 1.2 to 3.6, and particularly preferably 1.3 to 3.4. The molecular weight distribution is measured by gel permeation chromatography (GPC).

[0032] The maleimide compound (A) preferably further has an arylene structure in the molecule that is oriented and bonded at the meta position. Examples of the arylene structure that is oriented and bonded at the meta position include an arylene structure in which a structure containing a maleimide group (i.e., other than Rb) is bonded at the meta position (an arylene structure in which a structure containing a maleimide group is substituted at the meta position). The arylene structure that is oriented and bonded at the meta position is an arylene group that is oriented and bonded at the meta position, such as a group represented by the following formula (3). Examples of the arylene structure that is oriented and bonded at the meta position include m-arylene groups such as an m-phenylene group and an m-naphthylene group, and more specifically, examples of the arylene structure that is oriented and bonded at the meta position include a group represented by the following formula (3).

[0033]

[0034] Specific examples of the maleimide compound (A) include maleimide compounds represented by the following formulas (4) to (6). These maleimide compounds (A) further have an arylene group in the molecule that is oriented and bonded at the meta position, such as the group represented by formula (3).

[0035] In formula (4), n represents 0.95 to 10.

[0036] In formula (5), n represents 0.95 to 10.

[0037] In formula (6), n represents 0.95 to 10.

[0038] The method for producing the maleimide compound (A) is not particularly limited as long as it can produce the maleimide compound (A). Specifically, the maleimide compound (A) can be obtained by a so-called maleimide reaction in which an amine compound represented by the following formula (7) is reacted with maleic anhydride in an organic solvent such as toluene in the presence of a catalyst such as toluenesulfonic acid. More specifically, after the maleimide reaction, unreacted maleic anhydride and other impurities are removed by washing with water or the like, and the solvent is removed under reduced pressure. A dehydrating agent may be used during this reaction. Note that a commercially available product may be used as the maleimide compound (A).

[0039] In formula (7), each Ra is independent. That is, each Ra may be the same group or different groups. For example, when q is 2 to 4, 2 to 4 Ra bonded to the same benzene ring may be the same group or different groups. Ra represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. Rb's are the same as Rb's in formula (1), and each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. q represents 0 to 4. r represents 0 to 3. n represents 0.95 to 10.

[0040] The amine compound represented by the formula (7) can be obtained, for example, by reacting 2,6-dimethylaniline with α,α'-dihydroxy-1,3-diisopropylbenzene in an organic solvent such as xylene using activated clay as a catalyst.

[0041] The content of the maleimide compound (A) in the resin composition of this embodiment is preferably 10 to 80 mass% based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C). This is believed to more reliably achieve the above-described effects (low dielectric properties, low thermal expansion coefficient, and adhesion). A more preferred content is 15 to 70 mass%.

[0042] (Hydrocarbon Compound (B)) The hydrocarbon compound (B) that can be used in this embodiment is preferably a hydrocarbon compound having an unsaturated double bond, and more preferably a compound that is liquid at 25°C and has a styrene structure having at least one unsaturated group.

[0043] Specific preferred examples of the hydrocarbon compound (B) include hydrocarbon compounds such as polyfunctional vinyl compounds, polyfunctional vinyl aromatic polymers, cyclic polyolefin compounds, and vinyl aromatic compound-conjugated diene compound copolymers.

[0044] The polyfunctional vinyl compound that can be used in this embodiment is not particularly limited as long as it is a polyfunctional vinyl compound having two or more vinyl groups in the molecule, and examples thereof include divinylbenzene, divinylnaphthalene, divinylbiphenyl, and polybutadiene.

[0045] The polyfunctional vinyl aromatic polymer usable in this embodiment is preferably a polymer containing at least a polyfunctional vinyl aromatic compound and / or its derivative polymerized therein. The polyfunctional vinyl aromatic polymer is not particularly limited as long as it is a polymer containing a structure derived from a polyfunctional vinyl aromatic compound and / or its derivative, and may be a polymer containing one or more polyfunctional vinyl aromatic compounds and / or their derivative-derived structures.

[0046] The polyfunctional vinyl aromatic polymer of this embodiment may further contain one or more structural units derived from a reactive monomer in addition to the structural units of the polyfunctional vinyl aromatic compound and / or its derivative. The reactive monomer is not particularly limited. For example, the hydrocarbon compound (B) of this embodiment may be a polyfunctional vinyl aromatic copolymer having a structural unit derived from a monovinyl aromatic compound such as styrene.

[0047] The hydrocarbon compound (B) preferably has a weight average molecular weight of 80 or more and 100,000 or less, more preferably 100 or more and 80,000 or less, and even more preferably 120 or more and 40,000 or less. In this specification, the weight average molecular weight of the hydrocarbon compound (B) may be measured by a general molecular weight measurement method, and specific examples include values ​​measured using gel permeation chromatography (GPC).

[0048] The content of the hydrocarbon compound (B) in the resin composition of this embodiment is preferably 5 to 80% by mass based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C). This is believed to more reliably achieve the above-mentioned effects (low dielectric properties, low thermal expansion coefficient, and adhesion). A more preferred content is 10 to 75% by mass, and even more preferably 10 to 70% by mass.

[0049] (Styrene-based polymer (C)) The styrene-based polymer (C) is not particularly limited as long as it is a styrene-based polymer that is solid at 25°C. Examples of the styrene-based polymer (C) include styrene-based polymers that are solid at 25°C and can be used as a resin contained in a resin composition used to form an insulating layer provided in a metal-clad laminate, a wiring board, etc. The resin composition used to form an insulating layer provided in a metal-clad laminate, a wiring board, etc. may be a resin composition used to form a resin layer provided in a resin-coated film, a resin-coated metal foil, etc., or may be a resin composition contained in a prepreg. It is believed that by including the styrene-based polymer (C), the resin of this embodiment can obtain even lower dielectric properties (low dielectric tangent), a lower thermal expansion coefficient, and adhesion in the cured product.

[0050] The styrene-based polymer (C) may be, for example, a polymer obtained by polymerizing a monomer containing a styrene-based monomer, and may be a styrene-based copolymer. Examples of the styrene-based polymer (C) include copolymers obtained by copolymerizing one or more of the styrene-based monomers with one or more other monomers copolymerizable with the styrene-based monomer. The styrene-based copolymer may be a random copolymer or a block copolymer, as long as it has a structure derived from the styrene-based monomer in the molecule. Examples of the block copolymer include a binary copolymer of a structure (repeating unit) derived from the styrene-based monomer and the other copolymerizable monomer (repeating unit), and a terpolymer of a structure (repeating unit) derived from the styrene-based monomer, the other copolymerizable monomer (repeating unit), and a structure (repeating unit) derived from the styrene-based monomer.

[0051] The styrene-based monomer is not particularly limited, but examples thereof include styrene, styrene derivatives, styrene in which some of the hydrogen atoms on the benzene ring have been substituted with alkyl groups, styrene in which some of the hydrogen atoms on the vinyl group have been substituted with alkyl groups, vinyltoluene, α-methylstyrene, butylstyrene, dimethylstyrene, isopropenyltoluene, etc. These styrene-based monomers may be used alone or in combination of two or more.

[0052] Furthermore, the styrene polymer (C) preferably has an ethylene structural unit and a butylene structural unit in the molecule.

[0053] The ethylene structural unit is not particularly limited, and examples thereof include those having an ethylene structure among the structural units (repeating units) derived from the other copolymerizable monomers. The ethylene structural unit is a structure derived from a 1,4-bond of a conjugated diene monomer (conjugated dienes), and the atom or group bonded to the carbon of the -C-C- bond of the main chain is a hydrogen atom or a methyl group. Specific examples of the conjugated diene monomer include 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene), 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-cyclohexadiene. Therefore, specific examples of the ethylene structural unit include structural units having an ethylene structure among structural units derived from the conjugated dienes, and more specific examples include structural units having an ethylene structure (1,4-addition structural units) among structural units (repeating units) derived from 1,3-butadiene.

[0054] The butylene structural unit is not particularly limited, and examples thereof include those having a butylene structure among the structural units (repeating units) derived from the other copolymerizable monomers. The butylene structural unit is at least one of a structure derived from a 1,2-bond of a conjugated diene monomer (conjugated dienes) and a structure derived from a 3,4-bond of a conjugated diene monomer (conjugated dienes), and at least one of the atoms or groups bonded to the carbon of the -C-C- bond of the main chain is a side chain having two or more carbon atoms. Therefore, specific examples of the butylene structural unit include structural units having a butylene structure among the structural units derived from the conjugated dienes, and more specific examples include structural units having a butylene structure (at least one of a 1,2-addition structural unit and a 3,4-addition structural unit) among the structural units (repeating units) derived from 1,3-butadiene. The butylene structural unit may be, for example, a hydrogenated structural unit. It is believed that the higher the proportion of butylene structural units in the styrene polymer (C), the lower the thermal expansion coefficient can be.

[0055] The styrene polymer (C) may contain a structural unit derived from another copolymerizable monomer other than the ethylene structural unit and the butylene structural unit as the structural unit (repeating unit) derived from the other copolymerizable monomer. Examples of such another copolymerizable monomer include, but are not limited to, olefins such as α-pinene, β-pinene, and dipentene, and non-conjugated dienes such as 1,4-hexadiene and 3-methyl-1,4-hexadiene.

[0056] Specific examples of the styrene polymer (C) include methylstyrene (ethylene / butylene) methylstyrene copolymer, methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, styrene-isoprene copolymer, styrene-isoprene styrene copolymer, styrene (ethylene / butylene) styrene copolymer, styrene (ethylene-ethylene / propylene) styrene copolymer, styrene-butadiene styrene copolymer, and styrene (butadiene / butylene) styrene copolymer.

[0057] The styrene polymer (C) more preferably contains a hydrogenated styrene copolymer in which at least a portion of the styrene copolymer is hydrogenated, which has the advantage of further reducing Df (dielectric loss tangent).

[0058] Examples of the hydrogenated styrene copolymer include hydrogenated products of the styrene copolymers. More specific examples of the hydrogenated styrene copolymer include hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer, hydrogenated methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, hydrogenated styrene-isoprene copolymer, hydrogenated styrene-isoprene styrene copolymer, hydrogenated styrene (ethylene / butylene) styrene copolymer, and hydrogenated styrene (ethylene-ethylene / propylene) styrene copolymer.

[0059] As the styrene polymer (C), the above-exemplified styrene polymers may be used alone or in combination of two or more.

[0060] The styrene polymer (C) preferably has a weight average molecular weight of 1,000 to 300,000, more preferably 10,000 to 250,000, and even more preferably more than 40,000 to 200,000. In this specification, the weight average molecular weight of the styrene polymer (C) may be measured by a general molecular weight measurement method, and specific examples include values ​​measured using gel permeation chromatography (GPC).

[0061] As the styrene-based polymer (C), commercially available products may be used, such as V9827, V9461, 2002, and 7125F manufactured by Kuraray Co., Ltd., FTR2140 and FTR6125 manufactured by Mitsui Chemicals, Inc., and H1041 and M1913 manufactured by Asahi Kasei Corporation.

[0062] The content of the styrene-based polymer (C) in the resin composition of this embodiment is preferably 5 to 40 mass% based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene-based polymer (C). This is believed to more reliably achieve the above-mentioned effects (low dielectric properties, low thermal expansion coefficient). A more preferred content is 10 to 30 mass%.

[0063] (Silica Filler (D)) The silica filler (D) used in this embodiment is a silica filler that satisfies the following requirements in its particle size distribution: when D10 is the cumulative 10% particle diameter on a volume basis, D50 is the cumulative 50% particle diameter on a volume basis, and D90 is the cumulative 90% particle diameter on a volume basis, the ratio V (D10 / D50) of D10 to D50 is 0.55 or more, and the ratio W (D50 / D90) of D50 to D90 is 0.60 or more. By using such a silica filler (D), it is possible to improve moldability while maintaining properties such as low dielectric properties and a low thermal expansion coefficient in the resin composition.

[0064] In a preferred embodiment, when the mode diameter of the silica filler (D) is less than 1.0 μm, the ratio V and the ratio W are preferably 0.60 or more. When the mode diameter is 1.0 μm or more, the ratio V and the ratio W are preferably 0.70 or more. In this specification, the "mode diameter" refers to the most frequent value (peak) of particle diameters in the particle size distribution.

[0065] In this specification, the particle size distribution is a value measured by particle size distribution measurement using a laser diffraction / scattering method, and can be measured, for example, using a laser diffraction / scattering particle size distribution measuring device "LA-960V2" (Horiba, Ltd.) used in the examples described later. The measurement is performed using a resin varnish containing a maleimide compound (A), a hydrocarbon-based compound (B), a styrene-based polymer (C), and silica (D).

[0066] The silica filler (D) is not particularly limited as long as it satisfies the above-mentioned requirements and can be used as an inorganic filler. Preferably, a spherical silica filler with a reduced hydroxyl group content is used. Preferably, the spherical silica filler does not contain silica fillers with a diameter of 50 nm or less.

[0067] The silica filler (D) as described above can be obtained, for example, by the following method.

[0068] First, R ｍ Six ３ By the hydrolysis and condensation reaction of the above, a spherical polysiloxane containing T units is obtained. ３ are hydrogen atoms or independently selectable organic groups having 1 to 18 carbon atoms, X is a hydrolyzable group, and the T units are R ３ SiO ３ The spherical polysiloxane is then calcined under a dry oxidizing gas atmosphere to obtain spherical silica powder with a low hydroxyl group content. The calcination temperature is between 850 and 1200°C. The obtained spherical silica powder has a Q １ Unit, Q ２ Unit, Q ３ Units and Q ４It is composed of at least one unit selected from the following: １ The unit is Si(OH) ３ O- and Q ２ The unit is Si(OH) ２ O ２ - and Q ３ The unit is SiOHO ３ - and Q ４ The unit is SiO ４ - and Q ４ The content of the unit is greater than or equal to 95%.

[0069] In the silica filler (D) of this embodiment, it is preferable that the content of hydroxy groups (OH groups) is low. ４ The content of the unit is preferably 95% or more, which is thought to have the advantage of reducing dielectric loss.

[0070] The hydrolyzable group is preferably an alkoxy group or a halogen atom. The catalyst for the hydrolysis condensation reaction may be a salt or an acid.

[0071] The oxidizing gas preferably contains oxygen gas to completely oxidize the organic compounds in the polysiloxane. A preferred oxygen gas is air. The calcination step is preferably carried out by electrical heating or indirect gas heating. The calcination temperature is more preferably between 850 and 1100°C, and the calcination time is preferably between 6 and 12 hours.

[0072] The spherical polysiloxane may further contain Q units, D units, and / or M units, where Q units = SiO ４ - and D unit = R ４ R ５ SiO ２ - and M unit = R ６ R ７ R ８ SiO ２ In the above chemical formula, R ４ , R ５ , R ６ , R ７ and R ８are each independently selected hydrogen atoms or hydrocarbon groups of 1 to 18 carbon atoms.

[0073] Furthermore, the obtained spherical silica powder may be subjected to a surface treatment. That is, the silica filler (D) of this embodiment may be a surface-treated silica filler or a non-surface-treated silica filler. Examples of the surface treatment include treatment with a silane coupling agent.

[0074] Silane coupling agents that can be used for surface treatment include (R Ａ９ ) ａ (R Ａ１０ ) ｂ Si(M) ４－ａ－ｂ In the above chemical formula, R Ａ９ and R Ａ１０ are independently selectable hydrocarbon groups having 1 to 18 carbon atoms, hydrogen atoms, or hydrocarbon groups having 1 to 18 carbon atoms substituted with a functional group. The functional groups include at least one selected from the group consisting of organic functional groups such as vinyl groups, allyl groups, styryl groups, epoxy groups, aliphatic amino groups, aromatic amino groups, methacryloxypropyl groups, acryloxypropyl groups, ureidopropyl groups, chloropropyl groups, mercaptopropyl groups, polysulfide groups, and isocyanatopropyl groups. M is an alkoxy group having 1 to 18 carbon atoms or a halogen atom, a=0, 1, 2, or 3, b=0, 1, 2, or 3, and a+b=1, 2, or 3, and the disilazane is represented by (R Ａ１１ R Ａ１２ R Ａ１３ )SiNHSi(R Ａ１４ R Ａ１５ R Ａ１６ ) and R Ａ１１ , R Ａ１２ , R Ａ１３ , R Ａ１４ , R Ａ１５ and R Ａ１６ is an independently selectable hydrocarbon group having 1 to 18 carbon atoms or a hydrogen atom.

[0075] The silica filler obtained as described above is preferably further subjected to dry or wet sieving or inertial classification to remove coarse particles of 1 μm, 3 μm, 5 μm, 10 μm, 20 μm or more from the spherical silica powder filler.

[0076] The content of the silica filler (D) is preferably 50 parts by mass or more and 200 parts by mass or less, and more preferably 70 parts by mass or more and 170 parts by mass or less, relative to 100 parts by mass of the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C). By including the silica filler (D) in such an amount, it is believed that the resin composition of this embodiment can more reliably obtain low dielectric properties and excellent adhesion in the cured product thereof.

[0077] The resin composition of this embodiment may contain an inorganic filler other than the silica filler (D) as long as the effects of the present invention are not impaired. The inorganic filler other than the silica filler (D) is not particularly limited as long as it can be used as an inorganic filler contained in the resin composition. Specific examples include fillers made of at least one material selected from the group consisting of metal oxides such as alumina, titanium oxide, magnesium oxide, and mica, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, talc, aluminum borate, barium sulfate, aluminum nitride, silicon nitride, magnesium carbonate such as anhydrous magnesium carbonate, boron nitride, calcium carbonate, etc. Among these, anhydrous magnesium carbonate filler, alumina filler, and silicon nitride filler are preferred.

[0078] <Other Components> The resin composition according to this embodiment may contain components (other components) other than the above-described components, as necessary, within a range that does not impair the effects of the present invention. Examples of other components contained in the resin composition according to this embodiment include organic components other than the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C); and additives such as catalysts (e.g., reaction initiators and reaction accelerators), flame retardants, polymerization inhibitors, polymerization retarders, free radical compounds, flame retardant aids, antifoaming agents, leveling agents, antioxidants, heat stabilizers, antistatic agents, UV absorbers, dyes and pigments, dispersants, and lubricants.

[0079] The organic component other than the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C) may be, for example, a compound that reacts with or does not react with at least one of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C). Specific examples of the organic component include polyphenylene ether compounds, oxazine compounds, epoxy compounds, cyanate ester compounds, and active ester compounds.

[0080] As described above, the resin composition according to this embodiment may contain a reaction initiator (catalyst) and a reaction accelerator. The radical polymerization (curing) reaction of the resin composition may proceed even without a reaction initiator. However, depending on the process conditions, it may be difficult to raise the temperature high enough for curing to proceed, so a reaction initiator may be added. The reaction initiator and reaction accelerator are not particularly limited as long as they can accelerate the curing reaction of the resin composition. Specific examples include metal oxides, azo compounds, peroxides, imidazole compounds, phosphorus-based curing accelerators, and amine-based curing accelerators.

[0081] (Uses) The resin composition of the present embodiment is mainly used in producing prepregs, as described below. In addition to prepregs, the resin composition of the present embodiment is also used in forming resin layers provided in resin-coated metal foils and resin-coated films, and insulating layers provided in metal-clad laminates and wiring boards.

[0082] The resin composition according to the present embodiment is a resin composition that has a high Tg, excellent adhesion and moldability, and can produce a cured product with low dielectric properties and a low coefficient of thermal expansion. Therefore, a wiring board having an insulating layer formed using the resin composition according to the present embodiment has the advantages of low transmission loss, excellent moldability, high reliability, and little warping.

[0083] (Production Method) The method for producing the resin composition of the present embodiment is not particularly limited, and examples thereof include a method in which the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C) are mixed with other organic components and / or additives as necessary, and then the silica filler (D) is added. Specifically, in the case of obtaining a varnish-like composition containing an organic solvent, the method includes the methods described in the description of the prepreg below.

[0084] By using the resin composition according to this embodiment, a prepreg, a metal-clad laminate, a wiring board, a resin-coated metal foil, and a resin-coated film can be obtained as follows.

[0085] (Prepreg, Resin-Coated Film, Metal-Clad Laminate, Wiring Board, and Resin-Coated Metal Foil) Next, a prepreg for wiring boards, a metal-clad laminate, a wiring board, and a resin-coated metal foil using the resin composition of this embodiment will be described. Note that the respective reference numerals in the drawings indicate the following: 1 prepreg, 2 resin composition or semi-cured resin composition, 3 fibrous base material, 11 metal-clad laminate, 12 insulating layer, 13 metal foil, 14 wiring, 21 wiring board, 31 resin-coated metal foil, 32, 42 resin layer, 41 resin-coated film, 43 support film.

[0086] FIG. 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention.

[0087] As shown in Fig. 1 , the prepreg 1 according to this embodiment comprises the resin composition or a semi-cured product of the resin composition 2, and a fibrous base material 3. Examples of this prepreg 1 include those in which the fibrous base material 3 is present in the resin composition or a semi-cured product thereof 2. That is, this prepreg 1 comprises the resin composition or a semi-cured product thereof, and the fibrous base material 3 present in the resin composition or a semi-cured product thereof 2.

[0088] In this embodiment, the term "semi-cured product" refers to a resin composition that has been partially cured to the extent that it can be further cured. That is, the semi-cured product is a resin composition that has been semi-cured (B-staged). For example, when a resin composition is heated, the viscosity initially gradually decreases, and then curing begins, and the viscosity gradually increases. In such a case, the semi-cured state can be exemplified by the state between when the viscosity starts to increase and when the composition is completely cured.

[0089] The prepreg obtained using the resin composition according to this embodiment may comprise a semi-cured product of the resin composition as described above, or may comprise the uncured resin composition itself. That is, it may be a prepreg comprising a semi-cured product of the resin composition (the resin composition in B stage) and a fibrous substrate, or a prepreg comprising the resin composition before curing (the resin composition in A stage) and a fibrous substrate. Specific examples include those in which a fibrous substrate is present in the resin composition. The resin composition or its semi-cured product may be obtained by heating and drying the resin composition.

[0090] The resin composition according to the present embodiment is often prepared in the form of a varnish and used as a resin varnish when producing the prepreg, or the resin-coated metal foil or metal-clad laminate described below. Such a resin varnish is prepared, for example, as follows.

[0091] First, each component soluble in an organic solvent, such as a resin component and a reaction initiator, is added to an organic solvent and dissolved. Heating may be performed as necessary. Then, an inorganic filler, such as silica filler (D), which is a component insoluble in an organic solvent, is added and dispersed using a ball mill, bead mill, planetary mixer, roll mill, or the like until a predetermined dispersion state is achieved, thereby preparing a varnish-like resin composition. The organic solvent used here is not particularly limited as long as it dissolves resin components, such as the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C), and does not inhibit the curing reaction. Specific examples include toluene, methyl ethyl ketone, cyclohexanone, cyclopentanone, methylcyclohexane, dimethylformamide, and propylene glycol monomethyl ether acetate. These may be used alone or in combination of two or more.

[0092] As a method for producing the prepreg 1 of this embodiment using the varnish-like resin composition of this embodiment, for example, a method of impregnating the fibrous base material 3 with the resin composition 2 in the form of a resin varnish and then drying it can be mentioned.

[0093] Specific examples of fibrous substrates used in producing prepregs include glass cloth, aramid cloth, polyester cloth, LCP (liquid crystal polymer) nonwoven fabric, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. The use of glass cloth results in a laminate with excellent mechanical strength, and flattened glass cloth is particularly preferred. The glass cloth used in this embodiment is not particularly limited, but examples include low-dielectric-constant glass cloths such as E glass, S glass, NE glass, Q glass, and L glass. Flattening can be performed, for example, by continuously pressing the glass cloth with a press roll at an appropriate pressure to compress the yarns flat. The thickness of the fibrous substrate can generally be, for example, 0.01 to 0.3 mm.

[0094] The resin varnish (resin composition 2) is impregnated into the fibrous substrate 3 by immersion, coating, or the like. This impregnation can be repeated multiple times as necessary. In this case, it is also possible to repeat the impregnation using multiple resin varnishes with different compositions and concentrations, and to adjust the final composition (content ratio) and resin amount to the desired one.

[0095] The fibrous substrate 3 impregnated with the resin varnish (resin composition 2) is heated under desired heating conditions, for example, at a temperature of 80°C or higher and 180°C or lower for 1 minute or longer and 10 minutes or shorter. By heating, the solvent is volatilized from the varnish, reducing or removing the solvent, thereby obtaining a prepreg 1 in an uncured (A-stage) or semi-cured (B-stage) state.

[0096] 4, the resin-coated metal foil 31 of this embodiment has a configuration in which a resin layer 32 containing the above-mentioned resin composition or a semi-cured product of the resin composition is laminated with a metal foil 13. That is, the resin-coated metal foil of this embodiment may be a resin-coated metal foil comprising a resin layer containing the resin composition before curing (the resin composition in A stage) and a metal foil, or a resin-coated metal foil comprising a resin layer containing a semi-cured product of the resin composition (the resin composition in B stage) and a metal foil.

[0097] Examples of a method for producing such a resin-coated metal foil 31 include a method in which the resin composition in the form of a resin varnish as described above is applied to the surface of a metal foil 13 such as a copper foil, followed by drying. Examples of the application method include a bar coater, a comma coater, a die coater, a roll coater, a gravure coater, and the like.

[0098] As the metal foil 13, any metal foil that is used in metal-clad laminates, wiring boards, etc. can be used without any limitation, and examples thereof include copper foil and aluminum foil.

[0099] 5, the resin-coated film 41 of this embodiment has a configuration in which a resin layer 42 containing the above-mentioned resin composition or a semi-cured product of the resin composition is laminated on a film support substrate 43. That is, the resin-coated film of this embodiment may be a resin-coated film comprising the resin composition before curing (the resin composition in A stage) and a film support substrate, or may be a resin-coated film comprising a semi-cured product of the resin composition (the resin composition in B stage) and a film support substrate.

[0100] A method for producing such a resin-coated film 41 includes, for example, applying a resin varnish-like resin composition as described above to the surface of the film support substrate 43, and then evaporating the solvent from the varnish to reduce or remove the solvent, thereby obtaining a resin-coated film in a pre-cured (A stage) or semi-cured (B stage) state.

[0101] Examples of the film support substrate include electrically insulating films such as polyimide films, PET (polyethylene terephthalate) films, polyethylene naphthalate films, polyester films, polyparabanic acid films, polyether ether ketone films, polyphenylene sulfide films, aramid films, polycarbonate films, and polyarylate films.

[0102] In the resin-coated film and resin-coated metal foil of this embodiment, the resin composition or the semi-cured product thereof may be obtained by drying or heat-drying the resin composition, as in the prepreg described above.

[0103] The thickness of the metal foil 13 and the film support substrate 43 can be appropriately set depending on the desired purpose. For example, a metal foil 13 having a thickness of approximately 0.2 to 70 μm can be used. When the thickness of the metal foil is, for example, 10 μm or less, a carrier-attached copper foil having a release layer and a carrier for improved handling may be used. The resin varnish is applied to the metal foil 13 and the film support substrate 43 by coating, which can be repeated multiple times as needed. In addition, it is also possible to repeatedly apply multiple resin varnishes with different compositions and concentrations to adjust the final composition (content ratio) and resin amount to the desired level.

[0104] The drying or heating and drying conditions in the manufacturing method of the resin-coated metal foil 31 or the resin-coated film 41 are not particularly limited, but after applying a resin varnish-like resin composition to the metal foil 13 or the film support substrate 43, it is heated under the desired heating conditions, for example, at 50 to 180°C for about 0.1 to 10 minutes, to volatilize the solvent from the varnish and reduce or remove the solvent, thereby obtaining the resin-coated metal foil 31 or the resin-coated film 41 in a pre-cured (A stage) or semi-cured (B stage) state.

[0105] The resin-coated metal foil 31 or the resin-coated film 41 may be provided with a cover film or the like, as necessary. The provision of a cover film can prevent the inclusion of foreign matter, etc. The cover film is not particularly limited as long as it can be peeled off without damaging the shape of the resin composition. For example, a polyolefin film, a polyester film, a TPX film, a film formed by providing a release agent layer on any of these films, or even paper formed by laminating any of these films onto a paper substrate can be used.

[0106] 2, the metal-clad laminate 11 of this embodiment is characterized by having an insulating layer 12 containing a cured product of the above-described resin composition or a cured product of the above-described prepreg, and a metal foil 13. Note that the metal foil 13 used in the metal-clad laminate 11 may be the same as the metal foil 13 described above.

[0107] The metal-clad laminate 11 of this embodiment can also be produced using the resin-coated metal foil 31 or resin-coated film 41 described above.

[0108] A method for producing a metal-clad laminate using the prepreg 1, resin-coated metal foil 31, or resin-coated film 41 obtained as described above involves stacking one or more prepregs 1, resin-coated metal foils 31, or resin-coated films 41, and then stacking a metal foil 13 such as copper foil on both sides or one side of the prepreg 1, and then heat-pressure molding the stack to form an integrated laminate, thereby producing a double-sided or single-sided metal foil-clad laminate. The heat-pressure conditions can be set appropriately depending on the thickness of the laminate to be produced, the type of resin composition, and the like, but can be, for example, a temperature of 170 to 230°C, a pressure of 1.5 to 5.0 MPa, and a time of 60 to 150 minutes.

[0109] Alternatively, the metal-clad laminate 11 may be produced by forming a film-like resin composition on the metal foil 13 and then applying heat and pressure, without using the prepreg 1 or the like.

[0110] As shown in FIG. 3, the wiring board 21 of this embodiment has an insulating layer 12 containing the cured product of the resin composition or the cured product of the prepreg, and wiring 14 .

[0111] The resin composition of this embodiment is suitable for use as a material for the insulating layer of a wiring board. For example, a method for producing a wiring board 21 includes etching the metal foil 13 on the surface of the metal-clad laminate 11 obtained above to form a circuit (wiring), thereby obtaining a wiring board 21 having a conductor pattern (wiring 14) as a circuit on the surface of the laminate. In addition to the above-described methods, examples of the circuit formation method include circuit formation by a semi-additive process (SAP) or a modified semi-additive process (MSAP).

[0112] The prepreg, resin-coated film, and resin-coated metal foil obtained using the resin composition of this embodiment are very useful in industrial applications because, when cured, they have excellent low dielectric properties, low thermal expansion coefficient, adhesion (especially copper foil peel strength), formability, and high Tg. Furthermore, metal-clad laminates and wiring boards obtained by curing them also have the same excellent properties.

[0113] This specification discloses various aspects of the technology as described above, but the main technologies among them are summarized below.

[0114] A resin composition according to a first aspect of the present invention comprises a maleimide compound (A) having an indane structure in the molecule, a hydrocarbon compound (B) having a carbon-carbon unsaturated double bond, a styrene-based polymer (C) that is solid at 25°C, and a silica filler (D), wherein in the particle size distribution of the silica filler (D), when D10 is the volume-based cumulative 10% particle diameter, D50 is the volume-based cumulative 50% particle diameter, and D90 is the volume-based cumulative 90% particle diameter, the ratio V(D10 / D50) of D10 to D50 is 0.55 or more, and the ratio W(D50 / D90) of D50 to D90 is 0.60 or more.

[0115] A resin composition according to a second aspect of the present invention is the resin composition according to the first aspect, wherein the indane structure contains a structure represented by the above formula (1).

[0116] A resin composition according to a third aspect of the present invention is the resin composition according to the first or second aspect, wherein the hydrocarbon compound (B) is a compound that is liquid at 25°C and has a styrene structure having at least one unsaturated group.

[0117] A resin composition according to a fourth aspect of the present invention is the resin composition according to any one of the first to third aspects, wherein the styrene polymer (C) contains a hydrogenated styrene copolymer.

[0118] A resin composition according to a fifth aspect of the present invention is the resin composition of the fourth aspect, wherein the hydrogenated styrene-based copolymer comprises at least one selected from the group consisting of hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer, hydrogenated methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, hydrogenated styrene-isoprene copolymer, hydrogenated styrene-isoprene styrene copolymer, hydrogenated styrene (ethylene / butylene) styrene copolymer, and hydrogenated styrene (ethylene-ethylene / propylene) styrene copolymer.

[0119] A resin composition according to a sixth aspect of the present invention is the resin composition according to any one of the first to fifth aspects, wherein the content of the maleimide compound (A) is 10 to 80 mass % based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C).

[0120] A resin composition according to a seventh aspect of the present invention is the resin composition according to any one of the first to sixth aspects, wherein the content of the hydrocarbon compound (B) is 5 to 80 mass % based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C).

[0121] A resin composition according to an eighth aspect of the present invention is the resin composition according to any one of the first to seventh aspects, wherein the content of the styrene polymer (C) is 5 to 40 mass% with respect to the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C).

[0122] A resin composition according to a ninth aspect of the present invention is the resin composition of any one of the first to eighth aspects, wherein the content of the silica filler (D) is 50 to 200 parts by mass per 100 parts by mass of the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C).

[0123] A prepreg according to a tenth aspect of the present invention comprises the resin composition of any one of the first to ninth aspects or a semi-cured product of the resin composition, and a fibrous base material.

[0124] A resin-coated film according to an eleventh aspect of the present invention comprises a resin layer containing the resin composition of any one of the first to ninth aspects or a semi-cured product of the resin composition, and a support film.

[0125] A resin-coated metal foil according to a twelfth aspect of the present invention comprises a resin layer containing the resin composition of any one of the first to ninth aspects or a semi-cured product of the resin composition, and a metal foil.

[0126] A metal-clad laminate according to a thirteenth aspect of the present invention has an insulating layer containing a cured product of the resin composition according to any one of the first to ninth aspects or a cured product of the prepreg according to the tenth aspect, and a metal foil.

[0127] A wiring board according to a fourteenth aspect of the present invention has an insulating layer including a cured product of the resin composition according to any one of the first to ninth aspects or a cured product of the prepreg according to the tenth aspect, and wiring.

[0128] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0129] First, the components used in preparing the resin composition in this example will be described.

[0130] <Maleimide Compounds> Maleimide compound 1: maleimide compound (A) having an indane structure in the molecule (maleimide compound (A1) represented by the above formula (2)), "NE-X-9470S" (manufactured by DIC Corporation)

[0131] Maleimide compound 2: a maleimide compound not having an indane structure in the molecule, MIR-3000 (Nippon Kayaku Co., Ltd.)

[0132] <Hydrocarbon Compound (B)> Divinylbenzene (manufactured by Nippon Steel Chemical & Material Co., Ltd.)

[0133] <Styrene-based polymer (C)> Styrene-based polymer 1: hydrogenated styrene (ethylene butylene) styrene block copolymer ("Tuftec (registered trademark) H1041" manufactured by Asahi Kasei Corporation, weight average molecular weight Mw 80,000, solid at 25°C) Styrene-based polymer 2: hydrogenated styrene (ethylene butylene) styrene block copolymer acid-modified with maleic anhydride ("Tuftec (registered trademark) M1913" manufactured by Asahi Kasei Corporation, acid value 10 mg CH ３ ONa / g, weight average molecular weight Mw 60,000, solid at 25°C)

[0134] <Silica Filler (D)> Silica Filler 1 (manufactured by Zhejiang Sanshiji New Materials Technology Co., Ltd., "EQ0605-SMC") Silica Filler 2 (manufactured by Zhejiang Sanshiji New Materials Technology Co., Ltd., "EQ2410-SMC") Silica Filler 3 (vinylsilane-treated spherical silica, silica particles "SC2300-SVJ" manufactured by Admatechs Co., Ltd.)

[0135] Examples 1 to 4 and Comparative Examples 1 and 2 [Preparation Method] (Resin Varnish) First, the resin components were added to a solvent (toluene + MEK) and mixed in the blending ratios (parts by mass) shown in Table 2 below so that the solids concentration was 35% by mass. The resulting mixture was stirred for 60 minutes. Thereafter, an inorganic filler (silica filler) was added to the resulting mixture, and after pre-dispersion using a stirrer, the filler was dispersed using a bead mill. This resulted in a varnish-like resin composition (varnish).

[0136] (Preparation of Evaluation Board) A prepreg and an evaluation board (metal-clad laminate) were obtained as follows.

[0137] First, a fibrous substrate (glass cloth: #1067 type, NE glass, manufactured by Nitto Boseki Co., Ltd.) was impregnated with the obtained varnish, and then heated and dried for 3 minutes at 110°C to prepare a prepreg with a resin thickness of 67 µm. At this time, the content of the components constituting the resin composition by the curing reaction relative to the prepreg (resin content) was adjusted to be approximately 56 mass%.

[0138] Next, an evaluation substrate (metal-clad laminate) was obtained as follows.

[0139] Two sheets of each prepreg were stacked, and copper foil (Mitsui Mining & Smelting Co., Ltd. MT-GN copper foil thickness: 1.5 μm) was placed on both sides. This was used as a pressure body, and heated to 220°C at a temperature increase rate of 3°C / min, and then heated and pressurized at 220°C for 120 minutes under a pressure of 3 MPa, to obtain an evaluation substrate (metal-clad laminate) with copper foil bonded to both sides and a resin layer thickness of approximately 134 μm.

[0140] Using the prepreg and evaluation substrate (metal-clad laminate) prepared as described above, evaluation tests were carried out by the following methods.

[0141] <Evaluation Test> [Particle Size Distribution of Silica Filler] First, the particle size distribution of the silica filler used in each Example and Comparative Example was determined by measuring the resin varnishes of Example 1 (containing silica filler 1), Example 2 (containing silica filler 2), and Comparative Example 2 (containing silica filler 3) obtained above using a laser diffraction / scattering particle size distribution measuring device "LA-960V2" (manufactured by Horiba, Ltd.). The specifications of the device are as follows: Measurement principle: Mie scattering theory Measurement method: flow measurement Measurement range: 0.01 μm to 5000 μm Light source: LD (650 nm), approximately 5 mW, LED (405 mm), approximately 3 mW Detector: 1 ring-shaped 64-segment silicon photodiode, 5 4-channel array detectors, 3 silicon photodetectors Refractive index: 1.460-0.000i

[0142] The specifications of the measurement unit (circulation system) are as follows: Dispersion: ultrasonic probe Circulation: centrifugal pump Mixing: rotary blade flow type Cell material: synthetic quartz

[0143] The particle size distribution measurement conditions were as follows: Each measurement sample was placed in a flow cell via a sample bath using toluene as a dispersion solvent, and laser diffraction / scattering particle size distribution measurement was carried out in a stirred state.

[0144] The particle size distribution was analyzed and calculated using the analytical software LA-960 for Windows included with the LA-960V2. The D10, D50, and D90 were then determined. The ratios V (D10 / D50) and W (D50 / D90) were also calculated.

[0145] [Mode Diameter of Silica Filler] The mode diameter (the most frequent value of particles in particle size distribution) of each silica filler was analyzed and calculated using the analysis software LA-960 for Windows attached to the LA-960V2.

[0146] The results are shown in Table 1.

[0147]

[0148] (Moldability (smearing)) The appearance of each evaluation substrate (metal-clad laminate) (size: 250 mm x 250 mm) in the examples and comparative examples was observed visually to check for the presence or absence of smearing, with those without smearing being rated as passing and those with smearing being rated as failing. For reference, photographs of a passing sample (no smearing) and a failing sample (with smearing) are shown in Figure 6. The lower photograph is of a passing sample, and the upper photograph is of a failing sample.

[0149] (Copper foil peel strength) The copper foil on the top surface of the evaluation substrate (metal-clad laminate) was peeled off at a speed of 50 mm / min using a tensile tester (i.e., the copper foil on the top surface was peeled off from the insulating layer underneath), and the peel strength (N / mm ２ The peel strength is the copper foil peel strength. The higher the peel strength, the higher the copper foil adhesion. When the measured copper foil peel strength was 0.4 N / mm ２ If it was above that, it was considered a pass.

[0150] (Dielectric Property 1: Relative Permittivity (Dk) and Dielectric Loss Tangent (Df)) An unclad plate obtained by etching the copper foil from the 134 μm thick evaluation substrate (metal-clad laminate) was used as a test specimen, and the relative permittivity and dielectric loss tangent at 10 GHz were measured using a cavity resonator perturbation method. Specifically, a network analyzer (N5230A manufactured by Keysight Technologies, Inc.) was used to measure the relative permittivity (Dk) and dielectric loss tangent (Df) of the evaluation substrate at 10 GHz. In this test, a Dk of 3.10 or less and a Df of 0.0020 or less were considered to be pass.

[0151] (Glass Transition Temperature (Tg)) An unclad plate obtained by removing the copper foil from the evaluation substrate (metal-clad laminate) by etching was used as a test piece, and the Tg of the cured resin composition was measured using a viscoelasticity spectrometer "DMS6100" manufactured by Seiko Instruments Inc. At this time, dynamic viscoelasticity measurement (DMA) was performed using a tensile module at a frequency of 1 Hz, and the temperature at which tan δ was maximized when the temperature was raised from room temperature to 320°C at a heating rate of 5°C / min was taken as Tg (°C). In this test, a Tg of 230°C or higher was evaluated as passing.

[0152] (Thermal expansion coefficient) The copper foil was removed from the evaluation substrate (metal-clad laminate) by etching to obtain an unclad plate having a length of 25 mm and a width of 5 mm. The unclad plate was used as a test piece, and the dimensional change of the test piece was measured using a TMA device (TMA6000 manufactured by SII Nanotechnology Inc.) with a probe distance of 15 mm and a tensile load of 50 mV in the range of 25 to 320 ° C. From this dimensional change, the average thermal expansion coefficient in the range of 50 to 200 ° C. was calculated, and this average thermal expansion coefficient was taken as the thermal expansion coefficient (CTE: ppm / ° C.). In this test, a CTE of 15 ppm / ° C. or less was evaluated as passing.

[0153] The results are shown in Table 2.

[0154]

[0155] (Discussion) As is clear from the results shown in Table 2, it was confirmed that the resin composition of the present invention can provide a cured product having low dielectric properties (Dk and Df), a low coefficient of thermal expansion, a high Tg, and excellent adhesion and moldability. In contrast, Comparative Example 1, which used a resin composition not containing the maleimide compound (A) of the present invention, resulted in poor adhesion, Tg, and coefficient of thermal expansion. Furthermore, Comparative Example 2, which used a resin composition containing a silica filler that does not satisfy the requirements of the present invention, failed to provide sufficient moldability.

[0156] This application is based on Japanese Patent Application No. 2024-146835 filed on August 28, 2024, the contents of which are incorporated herein by reference.

[0157] In order to express the present invention, the present invention has been properly and sufficiently described above through embodiments with reference to specific examples, drawings, etc., but it should be recognized that those skilled in the art can easily make changes and / or improvements to the above-described embodiments. Therefore, unless changes or improvements made by those skilled in the art deviate from the scope of the claims set forth in the claims, such changes or improvements are construed as being encompassed within the scope of the claims.

[0158] The present invention has wide industrial applicability in the technical fields of electronic materials, electronic devices, optical devices, and the like.

Claims

A composition comprising: (A) a maleimide compound having an indane structure in the molecule; (B) a hydrocarbon compound having a carbon-carbon unsaturated double bond; (C) a styrene-based polymer that is solid at 25°C; and (D) a silica filler; In the particle size distribution of the silica filler (D), when D10 is the cumulative 10% particle diameter on a volume basis, D50 is the cumulative 50% particle diameter on a volume basis, and D90 is the cumulative 90% particle diameter on a volume basis, the ratio V(D10 / D50) of D10 to D50 is 0.55 or more, and the ratio W(D50 / D90) of D50 to D90 is 0.60 or more. 　 The resin composition according to claim 1, wherein the indane structure comprises a structure represented by the following formula (1): [In formula (1), each Rb independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group, and r represents 0 to 3.] 2. The resin composition according to claim 1, wherein the hydrocarbon compound (B) is a compound that is liquid at 25°C and has a styrene structure having at least one unsaturated group. 　 The resin composition according to claim 1 , wherein the styrene polymer (C) comprises a hydrogenated styrene copolymer. 　 The resin composition according to claim 4, wherein the hydrogenated styrene-based copolymer comprises at least one selected from the group consisting of hydrogenated methylstyrene (ethylene / butylene) methylstyrene copolymer, hydrogenated methylstyrene (ethylene-ethylene / propylene) methylstyrene copolymer, hydrogenated styrene-isoprene copolymer, hydrogenated styrene-isoprene styrene copolymer, hydrogenated styrene (ethylene / butylene) styrene copolymer, and hydrogenated styrene (ethylene-ethylene / propylene) styrene copolymer.

2. The resin composition according to claim 1, wherein the content of the maleimide compound (A) is 10 to 80 mass% based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C).

2. The resin composition according to claim 1, wherein the content of the hydrocarbon compound (B) is 5 to 80 mass% based on the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C).

2. The resin composition according to claim 1, wherein the content of the styrene-based polymer (C) is 5 to 40 mass% based on the total of the maleimide compound (A), the hydrocarbon-based compound (B), and the styrene-based polymer (C).

2. The resin composition according to claim 1, wherein the content of the silica filler (D) is 50 to 200 parts by mass per 100 parts by mass of the total of the maleimide compound (A), the hydrocarbon compound (B), and the styrene polymer (C). 　 A prepreg comprising the resin composition according to any one of claims 1 to 9 or a semi-cured product of the resin composition and a fibrous base material. 　 A resin-coated film having a resin layer containing the resin composition according to any one of claims 1 to 9 or a semi-cured product of the resin composition, and a support film. 　 A resin-coated metal foil comprising a resin layer containing the resin composition according to any one of claims 1 to 9 or a semi-cured product of the resin composition, and a metal foil. 　 A metal-clad laminate having an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 9 and a metal foil. 　 A wiring board having an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 9 and wiring. 　 A metal-clad laminate comprising an insulating layer comprising the cured product of the prepreg according to claim 10 and a metal foil. 　 A wiring board having an insulating layer containing the cured product of the prepreg according to claim 10 and wiring.

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