Resin composition, prepreg, resin-attached film, resin-attached metal foil, metal-clad laminate, and wiring board

Abstract

One aspect of the present invention relates to a resin composition containing: a reactive compound (A) that contains at least one of a vinyl phenyl group or a (meth)acrylate group; a crosslinking agent (B) that is a compound different from the reactive compound (A); a high molecular weight body (C) having a weight average molecular weight of 10,000 to 1,500,000; and an inorganic filler (D), wherein the content of the high molecular weight body (C) is more than 30 mass% and 50 mass% or less with respect to the total amount of the resin component of the resin composition, the inorganic filler (D) contains a titanic acid compound filler (D-1), and the content of the titanic acid compound filler (D-1) is 100 parts by mass to 400 parts by mass with respect to 100 parts by mass of the total amount of the resin component of the resin composition.

Description

Resin compositions, prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards

[0001] The present invention relates to resin compositions, prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards.

[0002] As the amount of information processing required for various electronic devices increases, mounting technologies such as the high integration of semiconductor devices, high density of wiring, and multilayering are advancing. Furthermore, the wiring boards used in various electronic devices, such as millimeter-wave radar substrates for automotive applications or wiring boards for antennas, are required to be high-frequency compatible. The substrate material that constitutes the insulating layer on such high-frequency compatible wiring boards is required to have a low dielectric loss tangent in order to reduce signal transmission losses. On the other hand, a high relative permittivity is also required in order to miniaturize the wiring boards.

[0003] As a substrate material having low dielectric properties, for example, a resin composition has been reported that contains at least one selected from the group consisting of polyphenylene ether derivatives having organic groups substituted with unsaturated aliphatic hydrocarbon groups, and maleimide compounds and derivatives thereof having at least two N-substituted maleimide groups (Patent Document 1). Furthermore, Patent Document 1 describes that the resin composition contains an inorganic filler, and that barium titanate, potassium titanate, strontium titanate, and calcium titanate can be used as the inorganic filler.

[0004] To increase the dielectric constant of the cured resin composition, it is conceivable to use fillers with a high dielectric constant, such as barium titanate, potassium titanate, strontium titanate, and calcium titanate, as described in Patent Document 1. However, even if the dielectric constant can be increased by including fillers with a high dielectric constant, the dielectric loss tangent may also increase, or properties such as heat resistance may decrease.

[0005] Furthermore, when the resin composition is used in resin-coated metal foil or metal-clad laminates, adhesion to copper foil may be required. Also, when used in resin-coated metal foil or resin-coated films, film performance (film handling) is important. However, the technology described in Patent Document 1 does not adequately address the need to achieve both adhesion and film performance simultaneously.

[0006] Japanese Patent Publication No. 2015-67700, International Publication No. 2021 / 059911

[0007] The present invention has been made in view of these circumstances, and aims to provide a resin composition that yields a cured product with a high relative permittivity, a low dielectric loss tangent, a high glass transition temperature (Tg), and good adhesion, as well as excellent film properties. The present invention also aims to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that can be obtained using the above resin composition.

[0008] After various studies, the inventors found that the above objective could be achieved by the following configuration, and through further investigation, they achieved the present invention.

[0009] In other words, a resin composition according to one aspect of the present invention is a resin composition containing a reactive compound (A) which contains at least one of a vinylphenyl group or a (meth)acrylate group, a crosslinking agent (B) which is a compound different from the reactive compound (A), a high molecular weight material (C) which has a weight-average molecular weight of 10,000 to 1,500,000, and an inorganic filler (D); the content of the high molecular weight material (C) is more than 30% by mass and 50% by mass or less with respect to the total amount of resin components of the resin composition; and the inorganic filler (D) contains a titanate compound filler (D-1), and the content of the titanate compound filler (D-1) is 100 parts by mass or more and 400 parts by mass or less with respect to 100 parts by mass of the total amount of resin components of the resin composition.

[0010] Figure 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. Figure 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. Figure 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. Figure 4 is a schematic cross-sectional view showing an example of a resin-coated metal foil according to an embodiment of the present invention. Figure 5 is a schematic cross-sectional view showing an example of a resin-coated film according to an embodiment of the present invention.

[0011] The following describes specific embodiments of the present invention, but the present invention is not limited to these embodiments.

[0012] [Resin Composition] The resin composition according to the embodiment of the present invention contains a reactive compound (A) containing at least one of a vinylphenyl group or a (meth)acrylate group, a crosslinking agent (B) which is a compound different from the reactive compound (A), a high molecular weight material (C) having a weight-average molecular weight of 10,000 to 1,500,000, and an inorganic filler (D). The content of the high molecular weight material (C) is more than 30% by mass and 50% by mass or less based on the total amount of resin components in the resin composition. The inorganic filler (D) contains a titanate compound filler (D-1). The content of the titanate compound filler (D-1) in the resin composition is 100 parts by mass or more and 400 parts by mass or less based on 100 parts by mass of the total amount of resin components in the resin composition.

[0013] With the above configuration, a cured product can be obtained that has a high relative permittivity, a low dielectric loss tangent, a high glass transition temperature (Tg), and good adhesion, as well as a resin composition with excellent film properties. Furthermore, by using the above resin composition, it is possible to provide prepregs, resin-coated films, resin-coated metal foils, metal-clad laminates, and wiring boards having the above-mentioned excellent performance.

[0014] The dielectric constant (Dk) of the cured resin composition of this embodiment is preferably 5 to 12 at a frequency of 10 GHz. On the other hand, the dielectric loss tangent (Df) of the cured resin composition of this embodiment is preferably 0.005 or less at a frequency of 10 GHz.

[0015] The components of the resin composition of this embodiment will be described in more detail below.

[0016] (Reactive compound (A)) The reactive compound (A) of this embodiment is not particularly limited as long as it contains at least one of a vinylphenyl group or a (meth)acrylate group and has reactivity such as radical polymerizability.

[0017] The number-average molecular weight (Mn) of the reactive compound (A) is preferably 1,000 to 8,000, more preferably 1,000 to 50,000, and even more preferably 1,000 to 4,000. The number-average molecular weight can be measured by any general molecular weight measurement method, specifically, values ​​measured using gel permeation chromatography (GPC).

[0018] If the number-average molecular weight (Mn) of the reactive compound (A) is within the above range, it is thought that it will react efficiently with the crosslinking agent (B) described later, increasing the crosslink density and more reliably achieving both high heat resistance, high Tg, and high peel strength. Furthermore, since the melt viscosity is also thought to be within an appropriate range, the occurrence of molding defects can be suppressed.

[0019] More specifically, the reactive compound (A) preferably comprises at least one selected from, for example, modified polyphenylene ether compounds and modified polystyrene compounds. Preferred embodiments are described below.

[0020] Modified Polyphenylene Ether Compounds The modified polyphenylene ether (PPE) compounds that can be used in this embodiment (hereinafter also simply referred to as "polyphenylene ether compounds" or "PPE compounds") are not particularly limited as long as they are modified PPE compounds that contain at least one of a vinylphenyl group or a (meth)acrylate group. For example, polyphenylene ether compounds having a group represented by the following formula (1) or formula (2) can be used. It is believed that by including such a modified polyphenylene ether compound, a resin composition can be obtained in which a cured product with low dielectric properties and high heat resistance can be obtained. In particular, it is believed that by using a polyphenylene ether compound having a (meth)acrylate group or a group represented by the following formula (2), a higher Tg and excellent adhesion can be obtained.

[0021] In formula (1), R １ ~R ３ They are independent of each other. That is, R １ ~R ３ These may be the same group or different groups. １ ~R ３ represents a hydrogen atom or an alkyl group. Ar represents an arylene group. p represents a value between 0 and 10. In formula (1) above, if p is 0, it indicates that Ar is directly bonded to the end of the polyphenylene ether.

[0022] The aforementioned arylene group is not particularly limited. Examples of such arylene groups include monocyclic aromatic groups such as phenylene groups, and polycyclic aromatic groups such as naphthalene rings. Furthermore, the arylene group also includes derivatives in which the hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkenyl group, alkynyl group, formyl group, alkylcarbonyl group, alkenylcarbonyl group, or alkynylcarbonyl group.

[0023] The alkyl group is not particularly limited, but for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl groups, ethyl groups, propyl groups, hexyl groups, and decyl groups.

[0024] In formula (2), R ４ This represents a hydrogen atom or an alkyl group.

[0025] The alkyl group is not particularly limited, but for example, alkyl groups having 1 to 18 carbon atoms are preferred, and alkyl groups having 1 to 10 carbon atoms are more preferred. Specifically, examples include methyl groups, ethyl groups, propyl groups, hexyl groups, and decyl groups.

[0026] Examples of the group represented by the formula (1) include a vinylbenzyl group (ethenylbenzyl group) represented by the following formula (3), and the like. The vinylbenzyl group represented by formula (3) has a vinylphenyl group and a methylene group, and therefore corresponds to the vinylphenyl group of the present embodiment. Further, examples of the group represented by the formula (2) include an acryloyl group, a methacryloyl group, and the like.

[0027]

[0028] More specific examples of the substituent (at least one of the group represented by the formula (1) and the group represented by the formula (2)) include vinylphenyl groups (ethenylbenzyl groups) such as o-ethenylbenzyl group, m-ethenylbenzyl group, and p-ethenylbenzyl group, vinylphenyl group, acryloyl group, methacryloyl group, and the like. The polyphenylene ether compound may have one type of the substituent, or may have two or more types thereof. The polyphenylene ether compound may, for example, have any one of o-ethenylbenzyl group, m-ethenylbenzyl group, p-ethenylbenzyl group and the like, or may have two or three of these groups.

[0029] The polyphenylene ether compound has a polyphenylene ether chain in the molecule, and preferably has a repeating unit represented by the following formula (4) in the molecule, for example.

[0030] In the formula (4), t represents 1 to 50. Further, R ５ to R ８ are each independent. That is, R ５ to R ８ may each be the same group or different groups. Further, R ５ to R ８ each represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Among these, a hydrogen atom and an alkyl group are preferable.

[0031] R ５ to R８ Specifically, the functional groups mentioned include the following:

[0032] The alkyl group is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl groups.

[0033] The alkenyl group is preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 10 carbon atoms. Specifically, examples include vinyl groups, allyl groups, and 3-butenyl groups.

[0034] The alkynyl group is preferably an alkynyl group having 2 to 18 carbon atoms, and more preferably an alkynyl group having 2 to 10 carbon atoms. Specifically, examples include the ethynyl group and the propa-2-in-1-yl group (propargyl group).

[0035] The alkylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group, but for example, alkylcarbonyl groups having 2 to 18 carbon atoms are preferred, and alkylcarbonyl groups having 2 to 10 carbon atoms are more preferred. Specifically, examples include acetyl group, propionyl group, butyryl group, isobutyryl group, pivaloyl group, hexanoyl group, octanoyl group, and cyclohexylcarbonyl group.

[0036] The alkenylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkenyl group, but for example, an alkenylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkenylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specifically, examples include acryloyl groups, methacryloyl groups, and crotonoyl groups.

[0037] The alkynylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group, but for example, an alkynylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkynylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specifically, for example, a propioloyl group can be mentioned.

[0038] Examples of the polyphenylene ether compounds include the polyphenylene ether compound represented by the following formula (5) and the polyphenylene ether compound represented by the following formula (6). Furthermore, these polyphenylene ether compounds may be used individually or in combination.

[0039]

[0040]

[0041] In equations (5) and (6), R ９ ~R １６ And R １７ ~R ２４ They are independent of each other. That is, R ９ ~R １６ And R １７ ~R ２４ These may be the same group or different groups. Also, R ９ ~R １６ And R １７ ~R ２４ X represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. １ and X ２ They are independent of each other. That is, X １ and X ２ This refers to either the same group or different groups. １ and X ２ represents at least one substituent selected from a vinylphenyl group or a (meth)acrylate group. A and B represent repeating units represented by the following formulas (7) and (8), respectively. In formula (6), Y represents a linear, branched, or cyclic hydrocarbon having 20 or fewer carbon atoms.

[0042]

[0043]

[0044] In equations (7) and (8), m and n represent values ​​from 0 to 20, respectively.２５ ~R ２８ And R ２９ ~R ３２ They are independent of each other. That is, R ２５ ~R ２８ And R ２９ ~R ３２ These may be the same group or different groups. Also, R ２５ ~R ２８ And R ２９ ~R ３２ This represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0045] The polyphenylene ether compound represented by formula (5) and the polyphenylene ether compound represented by formula (6) are not particularly limited as long as they satisfy the above configuration. Specifically, in formulas (5) and (6), R ９ ~R １６ And R １７ ~R ２４ As mentioned above, they are independent of each other. That is, R ９ ~R １６ And R １７ ~R ２４ These may be the same group or different groups. Also, R ９ ~R １６ And R １７ ~R ２４ This represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Among these, hydrogen atoms and alkyl groups are preferred.

[0046] In formulas (7) and (8), it is preferable that m and n represent values ​​between 0 and 20, as described above. Furthermore, it is preferable that m and n represent values ​​such that the sum of m and n is between 1 and 30. Therefore, it is more preferable that m represents values ​​between 0 and 20, n represents values ​​between 0 and 20, and the sum of m and n is between 1 and 30. Also, R ２５ ~R ２８ And R ２９ ~R ３２They are independent of each other. That is, R ２５ ~R ２８ And R ２９ ~R ３２ These may be the same group or different groups. Also, R ２５ ~R ２８ And R ２９ ~R ３２ This represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Among these, hydrogen atoms and alkyl groups are preferred.

[0047] R ９ ~R ３２ R in equation (4) above is ５ ~R ８ It is the same as this.

[0048] In formula (6) above, Y is a linear, branched, or cyclic hydrocarbon having 20 or fewer carbon atoms, as described above. Examples of Y include the group represented by the following formula (9).

[0049] In the above formula (9), R ３３ and R ３４ Each of these independently represents either a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group. Examples of the group represented by formula (9) include a methylene group, a methylmethylene group, and a dimethylmethylene group, among which the dimethylmethylene group is preferred.

[0050] In formulas (5) and (6) above, X １ and X ２ Each of these substituents is independently at least one of a vinylphenyl group or a (meth)acrylate group. Substituent X １ and X ２ Examples include the substituent represented by formula (1) and the substituent represented by formula (2). In the polyphenylene ether compound represented by formula (5) and the polyphenylene ether compound represented by formula (6), X １ and X ２These may be the same group or different groups.

[0051] More specific examples of polyphenylene ether compounds represented by formula (5) include, for example, the polyphenylene ether compound represented by the following formula (10).

[0052]

[0053] More specific examples of the polyphenylene ether compound represented by formula (6) include, for example, the polyphenylene ether compound represented by the following formula (11) and the polyphenylene ether compound represented by the following formula (12).

[0054]

[0055]

[0056] In equations (10) to (12) above, m and n are the same as m and n in equations (7) and (8) above. Also, in equations (10) and (11) above, R １ ~R ３ , p and Ar are R in formula (1) above. １ ~R ３ , is the same as p and Ar. Also, in equations (11) and (12) above, Y is the same as Y in equation (6) above. Also, in equation (12) above, R ４ R in the above equation (2) is ４ It is the same as this.

[0057] By using the modified polyphenylene ether compounds described above, it is believed that high Tg and adhesion can be improved while maintaining low dielectric loss tangent properties and excellent heat resistance.

[0058] Furthermore, modified polyphenylene ether compounds can be used individually or in combination of two or more types.

[0059] The polyphenylene ether compound used in the resin composition of this embodiment can be synthesized by known methods or a commercially available product can be used. Examples of commercially available products include "OPE-2st 1200" and "OPE-2st 2200" from Mitsubishi Gas Chemical Company, Inc., and "SA9000" from SABIC Innovative Plastics Corporation.

[0060] - Modified Polystyrene Compounds In this embodiment, a polyfunctional vinyl aromatic copolymer containing repeating units (a1) derived from a divinyl aromatic copolymer and repeating units (a2) derived from a monovinyl aromatic compound is preferably used as the modified polystyrene compound. Including such a polyfunctional vinyl aromatic copolymer in the reactive compound (A) has the advantage of improving high Tg and adhesion while maintaining low dielectric loss tangent properties and excellent heat resistance.

[0061] The polyfunctional vinyl aromatic copolymer preferably further contains a repeating unit represented by the following formula (13) as part of the repeating unit (a1) derived from the divinyl aromatic compound.

[0062]

[0063] In formula (13), R ｘ This represents an aromatic hydrocarbon group with 6 to 30 carbon atoms.

[0064] The aforementioned divinyl aromatic compound plays a role in forming a branched structure and making it polyfunctional, and also acts as a crosslinking component to provide heat resistance when the resulting soluble polyfunctional vinyl aromatic copolymer is thermoset.

[0065] Examples of divinyl aromatic compounds are not limited to aromatic compounds having two vinyl groups, but divinylbenzene (including each positional isomer or mixtures thereof), divinylnaphthalene (including each positional isomer or mixtures thereof), and divinylbiphenyl (including each positional isomer or mixtures thereof) are preferably used. These can be used individually or in combination of two or more. From the viewpoint of moldability, divinylbenzene (m-isomer, p-isomer, or mixtures of their positional isomers) is more preferred.

[0066] Examples of monovinyl aromatic compounds include styrene and other monovinyl aromatic compounds. However, styrene is essential, and it is desirable to use other monovinyl aromatic compounds in combination.

[0067] Styrene, as a monomer component, plays a role in imparting low dielectric properties and heat-resistant oxidative degradation to soluble polyfunctional vinyl aromatic copolymers, and as a chain transfer agent, it plays a role in controlling the molecular weight of the soluble polyfunctional vinyl aromatic copolymer.

[0068] Furthermore, monovinyl aromatic compounds other than styrene improve the solvent solubility and processability of soluble polyfunctional vinyl aromatic copolymers.

[0069] Examples of monovinyl aromatic compounds other than styrene include vinyl aromatic compounds other than styrene that have one vinyl group, such as vinylnaphthalene and vinylbiphenyl; and nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene. Preferably, ethylvinylbenzene (including each positional isomer or mixtures thereof), ethylvinylbiphenyl (including each positional isomer or mixtures thereof), or ethylvinylnaphthalene (including each positional isomer or mixtures thereof) are used because they prevent gelation of soluble polyfunctional vinyl aromatic copolymers, have a high effect in improving solvent solubility and processability, are low in cost, and are readily available. More preferably, from the viewpoint of dielectric properties and cost, ethylvinylbenzene (m-isomer, p-isomer, or mixtures of their positional isomers) is used.

[0070] Furthermore, within the limits that do not impair the effects of the present invention, in addition to divinyl aromatic compounds and monovinyl aromatic compounds, one or more other monomer components such as trivinyl aromatic compounds, trivinyl aliphatic compounds, divinyl aliphatic compounds, and monovinyl aliphatic compounds may be used, and structural units derived therefrom may be introduced into the soluble polyfunctional vinyl aromatic copolymer.

[0071] - Content of reactive compound (A) The content of reactive compound (A) in the resin composition of this embodiment is not particularly limited, but it is preferably 10% by mass or more and 60% by mass or less based on the total amount of resin components in the resin composition. It is believed that by including reactive compound (A) in such a content, the resin composition of this embodiment can more reliably obtain the effects brought about by reactive compound (A). A more preferred range for the content is 20% by mass or more and 50% by mass or less.

[0072] (Crosslinking agent (B)) The crosslinking agent (B) in this embodiment is a compound different from the reactive compound (A) and is not particularly limited as long as it acts as a crosslinking agent that can react with the reactive compound (A).

[0073] Specifically, for example, polyfunctional allyl compounds, polyfunctional acrylate compounds, polyfunctional methacrylate compounds, polyfunctional vinyl compounds, and / or polyfunctional maleimide compounds can be used as crosslinking agents (B).

[0074] Polyfunctional allyl compounds are not particularly limited as long as they are compounds having an allyl group in their molecule, but examples include triallyl isocyanurate compounds such as triallyl isocyanurate (TAIC), diallylbisphenol compounds, diallylalkyl isocyanurate compounds, 1,3,4,6-tetraallyl glycoluryl, and diallyl phthalate (DAP).

[0075] Polyfunctional acrylate compounds are compounds having acryloyl groups in their molecules, and examples include polyfunctional acrylate compounds having two or more acryloyl groups in their molecules. More specifically, examples include diacrylate compounds such as tricyclodecanedimethanol diacrylate.

[0076] Polyfunctional methacrylate compounds are compounds having a methacryloyl group in their molecule, such as polyfunctional methacrylate compounds having two or more methacryloyl groups in their molecule. More specifically, examples include dimethacrylate compounds such as tricyclodecanedimethanol dimethacrylate (DCP).

[0077] Polyfunctional vinyl compounds are compounds having vinyl groups in their molecules, and examples include polyfunctional vinyl compounds having two or more vinyl groups in their molecules. More specifically, examples include polyfunctional aromatic vinyl compounds other than the modified polystyrene compounds mentioned above, and vinyl hydrocarbon compounds. Examples of the aforementioned polyfunctional aromatic vinyl compounds include divinylbenzene.

[0078] The polyfunctional maleimide compound is not particularly limited as long as it is a compound having an N-substituted maleimide group in its molecule, but examples include polyfunctional maleimide compounds having two or more N-substituted maleimide groups in their molecule. The polyfunctional maleimide compound may be modified, for example, a modified maleimide compound in which part of the molecule is modified with an amine compound, a modified maleimide compound in which part of the molecule is modified with a silicone compound, and a modified maleimide compound in which part of the molecule is modified with both an amine compound and a silicone compound. A preferred example is a maleimide compound having a phenylmaleimide group in its molecule. By using a maleimide compound having a phenylmaleimide group in its molecule, the glass transition temperature of the cured resin composition can be increased.

[0079] More specifically, examples include 4,4'-diphenylmethanebismaleimide, polyphenylmethanebismaleimide, m-phenylenebismaleimide, bisphenol A diphenyl etherbismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, biphenylaralkyl polymaleimide compounds, maleimide compounds having at least one of an indan structure and an arylene structure oriented and bonded at the meta position in the molecule, and N-alkylmaleimide compounds.

[0080] The content of the crosslinking agent (B) in the resin composition of this embodiment is preferably 2% by mass or more and 50% by mass or less, and more preferably 5% by mass or more and 30% by mass or less, based on the total amount of resin components of the resin composition.

[0081] (High molecular weight material (C)) The resin composition of this embodiment contains a high molecular weight material (C) having a weight-average molecular weight of 10,000 to 1,500,000. Furthermore, the content of the high molecular weight material (C) is more than 30% by mass and 50% by mass or less of the total amount of resin components in the resin composition. By containing the high molecular weight material (C) in this amount, the resin composition of this embodiment can possess toughness and plasticity, and can suppress powder shedding and resin cracking when made into sheet-shaped films such as resin-coated metal foil or resin film. As a result, the handling properties when made into film are improved.

[0082] In a preferred embodiment, the high molecular weight material (C) comprises at least one of styrene copolymers and acrylic copolymers having a weight-average molecular weight within the above range. In this specification, the weight-average molecular weight can be any value measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC).

[0083] Examples of styrene copolymers that can be used in this embodiment include styrene copolymers that are solid at 25°C and can be used as resins in resin compositions used to form insulating layers in resin-coated metal foils, metal-clad laminates, and wiring boards.

[0084] Specific examples of styrene copolymers include copolymers obtained by copolymerizing one or more monomers containing styrene (styrene monomers) with one or more other monomers copolymerizable with styrene monomers. The styrene copolymer may be a random copolymer or a block copolymer. Examples of the block copolymer include a binary copolymer of structural units (repeating units) derived from the styrene monomer and structural units (repeating units) derived from the other copolymerizable monomers, and a ternary copolymer of structures (repeating units) derived from the styrene monomer, structural units (repeating units) derived from the other copolymerizable monomers, and structural units (repeating units) derived from the styrene monomer. The styrene copolymer may also be a hydrogenated styrene copolymer obtained by hydrogenating the styrene copolymer as described above.

[0085] The styrene monomer is not particularly limited, but examples include styrene, styrene derivatives, styrene in which some of the hydrogen atoms of the benzene ring are substituted with alkyl groups, styrene in which some of the hydrogen atoms of the vinyl group are substituted with alkyl groups, vinyltoluene, α-methylstyrene, butylstyrene, dimethylstyrene, and isopropenyltoluene. The styrene monomer may be used individually or in combination of two or more.

[0086] Furthermore, it is preferable that the styrene copolymer has ethylene structural units and butylene structural units in its molecule.

[0087] The ethylene structural unit is not particularly limited, but examples include structural units (repeating units) derived from other copolymerizable monomers that have an ethylene structure. 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 in 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, the ethylene structural units specifically include structural units having an ethylene structure among the structural units derived from the conjugated dienes, and more specifically, structural units having an ethylene structure (1,4-addition structural units) among the structural units (repeating units) derived from 1,3-butadiene.

[0088] The butylene structural unit is not particularly limited, but examples include structural units (repeating units) derived from other copolymerizable monomers that have a butylene structure. 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, the butylene structural unit specifically includes structural units derived from the conjugated dienes that have a butylene structure, and more specifically, structural units (repeating units) derived from 1,3-butadiene that have a butylene structure (at least one of a 1,2-addition structural unit and a 3,4-addition structural unit). The butylene structural unit may be, for example, a hydrogenated structural unit.

[0089] The styrene copolymer may contain structural units (repeating units) derived from other copolymerizable monomers other than the ethylene structural unit and the butylene structural unit. Such other copolymerizable monomers are not particularly limited, but examples include olefins such as α-pinene, β-pinene, and dipentene, and non-conjugated dienes such as 1,4-hexadiene and 3-methyl-1,4-hexadiene.

[0090] More specific examples of styrene copolymers 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. Furthermore, the styrene copolymer may be a styrene copolymer in which at least a portion of the styrene copolymer has been hydrogenated. In addition, the styrene copolymer may be a styrene copolymer in which at least a portion of the styrene copolymer has been acid-modified.

[0091] The styrene copolymer has a weight-average molecular weight of 10,000 to 1,500,000 as described above, but is preferably between 10,000 and 300,000, and more preferably between 10,000 and 200,000.

[0092] The styrene copolymer may be used alone or in combination of two or more types, as exemplified above.

[0093] Commercially available styrene copolymers can also be used, for example, V9827, V9461, 2002, and 7125F from Kuraray Co., Ltd., and H1221, H1251, H1041, H1043, H1517, M1913, S1609, S1613, and C5025 from Asahi Kasei Corporation.

[0094] Acrylic copolymers can also be used as the high molecular weight material (C). Examples of acrylic copolymers include those that are solid at 25°C and can be used as resins in resin compositions used to form insulating layers in resin-coated metal foils, metal-clad laminates, and wiring boards.

[0095] The acrylic polymers that can be used in this embodiment are not particularly limited as long as they contain structural units derived from (meth)acrylic acid ester monomers, but examples include acrylic block copolymers and acrylic random copolymers. Examples of acrylic block copolymers include copolymers containing structural units (c1) represented by the following formula (A-I) or structural units (c2) represented by the following formula (A-II).

[0096]

[0097]

[0098] In the structural unit (c2), Y is not particularly limited as long as it is a hydrocarbon group having one or more carbon atoms. Examples of the hydrocarbon group include methyl group, ethyl group, butyl group, hexyl group, pentyl group, heptyl group, octyl group, nonyl group, decyl group, dodecyl group, lauryl group, stearyl group, docosyl group, isostearyl group, 1-methylheptyl group, 2-ethylhexyl group, phenoxyethyl group, 2-hydroxyethyl group, 2-hydroxypropyl group, 2-hydroxybutyl group, 4-hydroxybutyl group, 2-carboxyethyl group, isobornyl group, and isoamyl group. The hydrocarbon group is preferably a hydrocarbon group having four or more carbon atoms, and among these, the butyl group and the 2-ethylhexyl group are preferred. The structural unit (c2) may contain these hydrocarbon groups individually or in combination of two or more. The structural unit (c2) is preferably a structural unit derived from butyl acrylate and a structural unit derived from 2-ethylhexyl acrylate. The structural unit (c1) is a structural unit derived from methyl methacrylate. Therefore, the acrylic block copolymer is preferably a block copolymer of a structural unit derived from methyl methacrylate as the structural unit (c1) and at least one of a structural unit derived from butyl acrylate and a structural unit derived from 2-ethylhexyl acrylate as the structural unit (c2). Examples of the block copolymer include a diblock product of the structural unit (c1) and the structural unit (c2), and a triblock product of the structural unit (c1), the structural unit (c2), and the structural unit (c1), with the triblock product being preferred. Specifically, the acrylic block copolymer is more preferably a block copolymer of methyl methacrylate and butyl acrylate, and more preferably a triblock product of methyl methacrylate, butyl acrylate, and methyl methacrylate. Furthermore, the structural unit (c1) preferably becomes a hard segment in the acrylic block copolymer, and its glass transition temperature is preferably, for example, 100 to 120°C.Furthermore, the structural unit (c2) is a soft segment in the acrylic block copolymer, and its glass transition temperature is preferably -60 to -40°C, and more preferably -50 to -40°C.

[0099] The acrylic block copolymer may contain the structural unit (c1) or the structural unit (c2), and may also contain structural units other than the structural unit (c1) and the structural unit (c2) (other structural units) (c3). The other structural units are not particularly limited as long as they copolymerize with the structural unit (c1) or the structural unit (c2), and examples include structural units derived from methacrylate esters or styrene, other than the structural units derived from methyl methacrylate.

[0100] The weight-average molecular weight of the acrylic block copolymer is 10,000 or more, preferably 30,000 or more, more preferably 40,000 or more, preferably 300,000 or less, and more preferably 200,000 or less. The acrylic block copolymer may be solid at 25°C or liquid at 25°C, but is preferably solid at 25°C. The weight-average molecular weight of the acrylic block copolymer is preferably a weight-average molecular weight that is solid at 25°C. Here, the weight-average molecular weight can be measured by a general molecular weight measurement method, specifically a value measured using gel permeation chromatography (GPC).

[0101] The acrylic random copolymer preferably has a structure represented by, for example, the following formulas (A-III), (A-IV), and (A-V).

[0102]

[0103]

[0104]

[0105] In the above formulas (A-III) to (A-V), x, y and z represent mole fractions, satisfying x+y+z≤1, 0<x≤0.2, 0.6≤y≤0.95, and 0.05≤z≤0.2.

[0106] In the above formula (A-IV), R １ is a hydrogen atom or a methyl group, and R ２ comprises at least one of a glycidyl group and an epoxidized alkyl group among a hydrogen atom, an alkyl group, a glycidyl group and an epoxidized alkyl group.

[0107] In the above formula (A-V), R ３ is a hydrogen atom or a methyl group, and R ４ is Ph (phenyl group), -COOCH ２ Ph or -COO(CH ２ ) ２ Ph.

[0108] Preferably, the main chain of the acrylic copolymer has at least one structure represented by formula (A-III), at least one structure represented by formula (A-IV), and at least one structure represented by formula (A-V).

[0109] When the main chain of an acrylic random copolymer has structures represented by formula (A-III), formula (A-IV) and formula (A-V), the arrangement order of the structures represented by formula (A-III), formula (A-IV) and formula (A-V) is not particularly limited. In this case, in the main chain of the acrylic random copolymer, the structures represented by formula (A-III) may or may not be consecutive, the structures represented by formula (A-IV) may or may not be consecutive, and the structures represented by formula (A-V) may or may not be consecutive.

[0110] Here, a supplementary explanation is given for the meaning that R ２ in the formula (A-IV) comprises at least one of a glycidyl group and an epoxidized alkyl group among a hydrogen atom, an alkyl group, a glycidyl group and an epoxidized alkyl group. As a premise, R in one structure represented by formula (A-IV) ２There is only one. The acrylic random copolymer will be explained separately for cases where it has only one structure represented by formula (A-IV) and cases where it has two or more structures.

[0111] In the former case, that is, when the acrylic random copolymer has a structure represented by one formula (A-IV), R ２ This is a glycidyl group or an epoxidized alkyl group.

[0112] In the latter case, that is, when the acrylic random copolymer has a structure represented by two or more formulas (A-IV), R in at least one of the structures represented by formula (A-IV) ２ R is a glycidyl group or an epoxidized alkyl group, and R is in the structure represented by the remaining formula (A-IV). ２ R is a hydrogen atom or an alkyl group. ２ However, since it is a glycidyl group or an epoxidized alkyl group, R in the entire structure represented by formula (A-IV) ２ However, a glycidyl group or an epoxidized alkyl group may also be used.

[0113] The structure represented by the above formula (A-V) is Ph (phenyl group), -COOCH ２ Ph, -COO(CH ２ ) ２ It has a pH. Ph, -COOCH ２ Ph, -COO(CH ２ ) ２ Since pH is thermally stable, it is believed that the strength of the cured resin composition can be increased, and the heat resistance of the cured product can be improved.

[0114] The weight-average molecular weight of the acrylic random copolymer is 10,000 or more, preferably between 10,000 and 900,000, and more preferably between 10,000 and 600,000. The acrylic random copolymer may be solid or liquid at 25°C, but is preferably solid at 25°C. The weight-average molecular weight of the acrylic random copolymer is preferably a weight-average molecular weight that is solid at 25°C. Here, the weight-average molecular weight can be measured by a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC).

[0115] As described above, the content of high molecular weight material (C) in the resin composition of this embodiment is more than 30% by mass and 50% by mass or less, relative to the total amount of resin components in the resin composition. A more preferred range for the content is more than 30% by mass and 40% by mass or less.

[0116] Furthermore, the content of the high molecular weight compound (C) is preferably 40 parts by mass or more and 130 parts by mass or less, based on 100 parts by mass of the total of the reactive compound (A) and the crosslinking agent (B). A more preferable content is 50 parts by mass or more and 120 parts by mass or less.

[0117] In the resin composition of this embodiment, the ratio of reactive compound (A) to high molecular weight material (C) is preferably, by mass ratio, reactive compound (A):high molecular weight material (C) = 15:85 to 85:15, and more preferably 20:80 to 63:37.

[0118] (Inorganic filler (D)) The resin composition of this embodiment includes an inorganic filler (D). The inorganic filler (D) contains a titanate compound filler (D-1), and the content of the titanate compound filler (D-1) is 100 parts by mass or more and 400 parts by mass or less, based on 100 parts by mass of the total amount of resin components of the resin composition. By including the titanate compound filler (D-1) in such a content, the resin composition of this embodiment can have a high dielectric constant in its cured product.

[0119] The titanate compound filler (D-1) is not particularly limited as long as it is a filler containing a titanate compound. Examples of the titanate compound filler include titanium oxide particles and titanate metal compound particles. Examples of the titanate metal compound particles include particles containing titanium and having a perovskite crystal structure or a composite perovskite crystal structure. Specific examples of the titanate metal compound particles include barium titanate particles, strontium titanate particles, calcium titanate particles, magnesium titanate particles, zinc titanate particles, lanthanum titanate particles, neodymium titanate particles, and aluminum titanate particles.

[0120] The titanate compound filler (D-1) preferably contains at least one selected from among the strontium titanate particles, barium titanate particles, calcium titanate particles, and titanium oxide particles. The titanate compound filler (D-1) may be used alone or in combination of two or more types.

[0121] The titanate compound filler (D-1) may be a surface-treated filler or an untreated filler, but it is preferable that it be a surface-treated filler. Examples of surface treatment include treatment with coupling agents such as silane coupling agents and titanium coupling agents. In other words, it is preferable that the titanate compound filler (D-1) is surface-treated with a silane coupling agent or a titanium coupling agent.

[0122] Examples of the silane coupling agent and the titanium coupling agent include coupling agents having at least one functional group selected from the group consisting of vinyl group, styryl group, methacryloyl group, acryloyl group, phenylamino group, isocyanurate group, ureido group, mercapto group, isocyanate group, epoxy group, and acid anhydride group. In other words, the silane coupling agent and the titanium coupling agent are compounds having at least one of vinyl group, styryl group, methacryloyl group, acryloyl group, phenylamino group, isocyanurate group, ureido group, mercapto group, isocyanate group, epoxy group, and acid anhydride group as a reactive functional group, and further having a hydrolyzable group such as a methoxy group or an ethoxy group.

[0123] Examples of silane coupling agents that have a vinyl group include vinyltriethoxysilane and vinyltrimethoxysilane. Examples of silane coupling agents that have a styryl group include p-styryltrimethoxysilane and p-styryltriethoxysilane. Examples of silane coupling agents that have a methacryloyl group include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropylethyldiethoxysilane. Examples of silane coupling agents that have an acryloyl group include 3-acryloxypropyltrimethoxysilane and 3-acryloxypropyltriethoxysilane. Examples of silane coupling agents include those having a phenylamino group, such as N-phenyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltriethoxysilane. Examples of titanium coupling agents include isopropyl(N-ethylaminoethylamino) titanate, isopropyltriisostearoyl titanate, titanium di(dioctyl pyrophosphate) oxyacetate, tetraisopropyl di(dioctyl phosphite) titanate, and neoalkoxytri(p-N-(β-aminoethyl)aminophenyl) titanate. These coupling agents may be used individually or in combination of two or more.

[0124] The dielectric constant of the titanate compound filler (D-1) is preferably 50 or higher, more preferably 60 to 800, and even more preferably 90 to 700. By including a titanate compound filler (D-1) having such a dielectric constant, a cured product with a high dielectric constant can be suitably obtained.

[0125] The average particle size of the titanate compound filler (D-1) is not particularly limited. The average particle size of the titanate compound filler (D-1) varies depending on the type of titanate compound filler (D-1), but for example, it is preferably 10 μm or less, more preferably 0.1 to 8 μm, and even more preferably 0.3 to 5 μm. When the titanate compound filler (D-1) has such a particle size, the insulating layer can be made thinner and the insulating reliability can be improved when the resulting resin composition is used as an insulating layer for a substrate. Here, the average particle size is the volume average particle size, for example, the volume-based cumulative 50% diameter (D50). Specifically, in the particle size distribution measured by a general laser diffraction / scattering method, the particle size (D50) is such that the cumulative particle size distribution from the small particle size side is 50% (volume basis) (volume-based cumulative 50% diameter in laser diffraction / scattering particle size distribution measurement).

[0126] The specific gravity of the titanate compound filler (D-1) is not particularly limited. Furthermore, the specific gravity of the titanate compound filler (D-1) varies depending on the type of titanate compound filler, but is generally between 3 and 7 g / cm³. ３ It is preferable that this be the case.

[0127] The inorganic filler (D) may contain only the titanate compound filler (D-1), or it may further contain the titanate compound filler (D-1) in addition to other inorganic fillers (D-2). Examples of other inorganic fillers (D-2) besides the titanate compound filler (D-1) include fillers made of at least one selected from the group consisting of solid silica such as spherical silica, hollow silica, alumina, metal oxides such as mica, metal hydroxides such as aluminum hydroxide and magnesium hydroxide, talc, aluminum borate, barium sulfate, and calcium carbonate. Among these, silica, mica, and talc are preferred as inorganic fillers (D-2), and it is more preferable to use a filler made of at least one selected from the group consisting of spherical silica. In the resin composition of this embodiment, the other inorganic fillers (D-2) may be used individually or in combination of two or more. The fillers may be used as is, or they may be surface-treated with a silane coupling agent or the like.

[0128] The content of the titanate compound filler (D-1) in the resin composition of this embodiment is 100 parts by mass or more and 400 parts by mass or less, based on 100 parts by mass of the total amount of resin components in the resin composition. A more preferred content is 150 parts by mass or more and 350 parts by mass or less, and even more preferably 200 parts by mass or more and 320 parts by mass or less.

[0129] Furthermore, the content of the titanate compound filler (D-1) is preferably 100 parts by mass or more and 350 parts by mass or less, and more preferably 150 parts by mass or more and 320 parts by mass or less, based on 100 parts by mass of the total of the reactive compound (A), the crosslinking agent (B), and the high molecular weight material (C).

[0130] If the inorganic filler (D) contains fillers other than the titanate compound filler (D-1), the content of the inorganic filler other than the titanate compound filler (D-1) is preferably 5 parts by mass or more and 100 parts by mass or less, and more preferably 10 parts by mass or more and 50 parts by mass or less, based on 100 parts by mass of the total of the reactive compound (A), the crosslinking agent (B), and the high molecular weight material (C).

[0131] (Other elastomers) The resin composition of this embodiment may contain other elastomers in addition to the high molecular weight material (C) described above.

[0132] Other resins that can be used in this embodiment include, for example, polybutadiene compounds, polyethylene resins, polysiloxane compounds, polyimide resins, phenoxy resins, polyester resins, and polyamide resins. Among these, from the viewpoint of improving film performance while maintaining the heat resistance of the resin composition, it is preferable to use a thermosetting resin that is liquid at 45°C, and among these, polybutadiene compounds are preferred.

[0133] For example, when the resin composition includes a polybutadiene compound as another resin, the mixing ratio (mass ratio) of the other resin components to the polybutadiene compound in the resin composition is preferably 99:1 to 80:20, and more preferably 97:3 to 85:15. Being within this range has the advantage of improving the flexibility of the resin composition while maintaining the heat resistance of the cured product, thus facilitating the manufacture of films and the like.

[0134] (Other Additives) The resin composition according to this embodiment may contain components other than those described above (other components) as necessary, as long as they do not impair the effects of the present invention. Examples of other components contained in the resin composition according to this embodiment include catalysts such as flame retardants, reaction initiators, and reaction accelerators, polymerization inhibitors, reaction retardants, free radical compounds, flame retardant aids, defoamers, leveling agents, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes and pigments, dispersants and lubricants and other additives.

[0135] As described above, the resin composition of this embodiment may contain a flame retardant. By including a flame retardant, the flame retardancy of the cured product of the resin composition can be enhanced.

[0136] The flame retardant that can be used in this embodiment is not particularly limited. Specifically, in fields where halogen-free is required, a phosphorus-containing flame retardant (phosphorus-based flame retardant) is preferably used. The phosphorus-based flame retardant is not particularly limited, but examples include HCA-based flame retardants, phosphate ester-based flame retardants, phosphazene-based flame retardants, bis-diphenylphosphine oxide-based flame retardants, and phosphinate-based flame retardants. Specific examples of HCA-based flame retardants include 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-yl-10-oxide, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, or compounds obtained by pre-reacting these. Specific examples of phosphate ester-based flame retardants include condensed phosphate esters of dixylenyl phosphate. Specific examples of phosphazene-based flame retardants include phenoxyphosphazene. A specific example of a bis-diphenylphosphine oxide-based flame retardant is xylylene bis-diphenylphosphine oxide. A specific example of a phosphinate-based flame retardant is, for example, a phosphinate metal salt of an aluminum dialkylphosphinate.

[0137] Furthermore, in fields where halogenated flame retardants such as brominated flame retardants are used, for example, ethylenedipentabromobenzene, ethylenebistetrabromoimide, decabromodiphenyl oxide, and tetradecabromodifenoxybenzene, which have a melting point of 300°C or higher, are preferred.

[0138] As flame retardants, each of the exemplified flame retardants may be used individually, or two or more may be used in combination.

[0139] If the resin composition of this embodiment contains a flame retardant, its content is preferably more than 0% by mass and 40% by mass or less, and more preferably 5% by mass or more and 30% by mass or less, based on the total amount of resin components in the resin composition.

[0140] 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 can proceed even without a reaction initiator. However, depending on the process conditions, it may be difficult to raise the temperature until curing proceeds, so a reaction initiator may be added. The reaction initiator and reaction accelerator are not particularly limited as long as they can promote the curing reaction of the resin composition. Specifically, examples include azo compounds, peroxides, metal oxides, imidazole compounds, phosphorus-based curing accelerators, amine-based curing accelerators, and the like.

[0141] Specific examples of the azo compound include, for instance, organic azo compounds such as azobisisobutyronitrile, 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile). Examples of the peroxide include, for instance, organic peroxides such as α,α'-di(t-butylperoxy)diisopropylbenzene (PBP), 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexine, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, and t-butylperoxyisopropyl monocarbonate. Examples of the imidazoles include 2-ethyl-4-methylimidazole (2E4MZ), 2-methylimidazole, 2-phenyl-4-methylimidazole, 2-phenylimidazole, and 1-benzyl-2-methylimidazole.

[0142] If the resin composition of this embodiment contains the reaction initiator and / or reaction initiator, the content thereof is not particularly limited, but for example, it is preferably 0.01% by mass or more and 5% by mass or less, and more preferably 0.05% by mass or more and 3% by mass or less, based on the total amount of resin components in the resin composition.

[0143] (Manufacturing Method) The method for manufacturing the resin composition is not particularly limited, and examples include mixing a reactive compound (A), a crosslinking agent (B), a high molecular weight material (C), and other resin components as needed, and then adding an inorganic filler (D). Specifically, when obtaining a varnish-like composition containing an organic solvent, the method described in the prepreg section below can be used.

[0144] Furthermore, by using the resin composition according to this embodiment, prepregs, metal-clad laminates, wiring boards, resin-coated metal foils, and resin-coated films can be obtained as follows. The resin composition of this embodiment has a high Tg, low dielectric loss tangent, and high relative permittivity, and has excellent adhesion to copper foil and film performance, making it particularly suitable for use in applications such as resin-coated films, resin-coated copper foils, and metal-clad laminates.

[0145] [Prepreg] Figure 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention. In the following description, each reference numeral in the figure indicates: 1 prepreg, 2 resin composition or semi-cured resin composition, 3 fibrous substrate, 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.

[0146] As shown in Figure 1, the prepreg 1 according to this embodiment comprises the resin composition or a semi-cured product 2 of the resin composition and a fibrous base material 3. This prepreg 1 comprises the resin composition or a semi-cured product 2 of the resin composition and a fibrous base material 3 present in the resin composition or the semi-cured product 2 of the resin composition.

[0147] In this embodiment, a semi-cured product refers to a resin composition that has been partially cured to the extent that it can be further cured. In other words, a semi-cured product is a resin composition that has been partially cured (stage B). For example, when a resin composition is heated, its viscosity gradually decreases at first, and then curing begins, causing the viscosity to gradually increase. In such a case, a semi-cured state would be the state between the time the viscosity begins to increase and before it is completely cured.

[0148] Furthermore, the prepreg obtained using the resin composition according to this embodiment may include a semi-cured product of the resin composition as described above, or it may include 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 stage B) and a fibrous substrate, or it may be a prepreg comprising the uncured resin composition (the resin composition in stage A) and a fibrous substrate. In addition, the resin composition or the semi-cured product of the resin composition may be the resin composition that has been dried or heat-dried.

[0149] When manufacturing prepregs, the resin composition 2 is often prepared in a varnish-like form for impregnation into the fibrous substrate 3, which is the base material for forming the prepreg. In other words, the resin composition 2 is usually a resin varnish prepared in a varnish-like form. Such a varnish-like resin composition (resin varnish) is prepared, for example, as follows.

[0150] First, each component of the resin composition that can be dissolved in an organic solvent (miscible component) is added to the organic solvent and dissolved. Heating may be used as needed during this process. Then, components that cannot be dissolved in the organic solvent (e.g., inorganic fillers, miscible components, etc.), which are used as needed, are added and dispersed using a ball mill, bead mill, planetary mixer, roll mill, etc., until a predetermined dispersion state is reached, thereby preparing a varnish-like resin composition. The organic solvent used here is not particularly limited as long as it dissolves the radical polymerizable compound, etc., and does not inhibit the curing reaction. Specifically, examples include toluene and methyl ethyl ketone (MEK).

[0151] The method for manufacturing the prepreg is not particularly limited as long as it can produce the prepreg. Specifically, when manufacturing the prepreg, the resin composition used in this embodiment is often prepared in a varnish-like state and used as a resin varnish, as described above.

[0152] Examples of the fibrous base material include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. When glass cloth is used, a laminate with excellent mechanical strength can be obtained, and flattened glass cloth is particularly preferred. Specific flattening methods include, for example, continuously applying pressure to the glass cloth with a press roll at an appropriate pressure to compress the yarn into a flat shape. The thickness of the fibrous base material commonly used is, for example, 0.008 mm or more and 0.3 mm or less.

[0153] The method for manufacturing the prepreg is not particularly limited as long as it can produce the prepreg. Specifically, when manufacturing the prepreg, the resin composition according to this embodiment is often prepared in a varnish-like state as described above and used as a resin varnish.

[0154] One method for manufacturing the prepreg 1 is to impregnate a fibrous substrate 3 with a resin composition 2, for example, a resin composition 2 prepared in the form of a varnish, and then dry it. The resin composition 2 is impregnated into the fibrous substrate 3 by immersion, coating, etc. It is also possible to repeat the impregnation process multiple times as needed. Furthermore, by repeating the impregnation process using multiple resin compositions with different compositions and concentrations, it is possible to adjust the final composition and amount of impregnation to the desired level.

[0155] The fibrous substrate 3 impregnated with the resin composition (resin varnish) 2 is heated under desired heating conditions, for example, at 80°C to 180°C for 1 minute to 10 minutes. Heating yields a prepreg 1 in either a pre-cured state (Stage A) or a semi-cured state (Stage B). Heating can also cause organic solvents to volatilize from the resin varnish, reducing or removing them.

[0156] [Metal-clad laminate] Figure 2 is a schematic cross-sectional view showing an example of a metal-clad laminate 11 according to an embodiment of the present invention.

[0157] As shown in Figure 2, the metal-clad laminate 11 is composed of an insulating layer 12 containing a cured product of the prepreg 1 shown in Figure 1, and a metal foil 13 laminated together with the insulating layer 12. That is, the metal-clad laminate 11 has an insulating layer 12 containing a cured product of a resin composition, and a metal foil 13 provided on the insulating layer 12. The insulating layer 12 may be made of the cured product of the resin composition, or it may be made of the cured product of the prepreg. The thickness of the metal foil 13 is not particularly limited and varies depending on the performance required of the final printed circuit board. The thickness of the metal foil 13 can be set appropriately according to the desired purpose, and is preferably, for example, 0.2 to 70 μm. Examples of the metal foil 13 include copper foil and aluminum foil, and if the metal foil is thin, it may be a carrier-equipped copper foil with a release layer and carrier to improve handling.

[0158] The method for manufacturing the metal-clad laminate 11 is not particularly limited as long as it can be used to manufacture the metal-clad laminate 11. Specifically, one method is to manufacture the metal-clad laminate 11 using a prepreg 1. This method involves stacking one or more prepregs 1, then stacking metal foil 13 such as copper foil on both the top and bottom surfaces or one or both surfaces, and then heat-pressure molding the metal foil 13 and prepreg 1 to laminate and integrate them, thereby producing a laminate 11 with metal foil on both sides or one side. In other words, the metal-clad laminate 11 is obtained by laminating metal foil 13 onto the prepreg 1 and then heat-pressure molding it. The heating and pressing conditions can be appropriately set depending on the thickness of the metal-clad laminate 11 to be manufactured and the type of composition of the prepreg 1. For example, the temperature can be 170 to 230°C, the pressure 3 to 5 MPa, and the time 60 to 150 minutes. The metal-clad laminate may also be manufactured without using a prepreg. For example, one method involves applying a varnish-like resin composition onto a metal foil to form a layer containing the resin composition on the metal foil, and then heating and pressurizing it.

[0159] [Wiring board] Figure 3 is a schematic cross-sectional view showing an example of a wiring board 21 according to an embodiment of the present invention.

[0160] As shown in Figure 3, the wiring board 21 according to this embodiment is composed of an insulating layer 12 made by curing the prepreg 1 shown in Figure 1, and wiring 14 laminated together with the insulating layer 12 and formed by partially removing the metal foil 13. That is, the wiring board 21 has an insulating layer 12 containing a cured resin composition and wiring 14 provided on the insulating layer 12. The insulating layer 12 may be made of the cured resin composition or of the cured prepreg.

[0161] The method for manufacturing the wiring board 21 is not particularly limited as long as it can be manufactured. Specifically, a method for manufacturing the wiring board 21 using the prepreg 1 can be mentioned. For example, this method involves etching the metal foil 13 on the surface of the metal-clad laminate 11 manufactured as described above to form wiring, thereby manufacturing a wiring board 21 in which wiring is provided as a circuit on the surface of the insulating layer 12. That is, the wiring board 21 is obtained by partially removing the metal foil 13 on the surface of the metal-clad laminate 11 to form a circuit. In addition to the above method, other methods for circuit formation include, for example, circuit formation by the semi-additive process (SAP) or the modified semi-additive process (MSAP).

[0162] [Resin-coated metal foil] Figure 4 is a schematic cross-sectional view showing an example of resin-coated metal foil 31 according to this embodiment.

[0163] As shown in Figure 4, the resin-coated metal foil 31 according to this embodiment comprises a resin layer 32 containing the resin composition or a semi-cured product of the resin composition, and a metal foil 13. This resin-coated metal foil 31 has the metal foil 13 on the surface of the resin layer 32. That is, this resin-coated metal foil 31 comprises the resin layer 32 and the metal foil 13 laminated together with the resin layer 32. In addition, the resin-coated metal foil 31 may have other layers between the resin layer 32 and the metal foil 13.

[0164] Furthermore, the resin layer 32 may contain a semi-cured product of the resin composition as described above, or it may contain the uncured resin composition. That is, the resin-coated metal foil 31 may comprise a resin layer containing a semi-cured product of the resin composition (the resin composition in stage B) and a metal foil, or it may comprise a resin layer containing the uncured resin composition (the resin composition in stage A) and a metal foil. Furthermore, the resin layer may contain the resin composition or a semi-cured product of the resin composition, and may or may not contain a fibrous substrate. Furthermore, the resin composition or the semi-cured product of the resin composition may be the resin composition that has been dried or heat-dried. Furthermore, the fibrous substrate may be the same as the fibrous substrate of the prepreg.

[0165] Furthermore, any metal foil used in metal-clad laminates can be used without limitation. Examples of metal foils include copper foil and aluminum foil.

[0166] The resin-coated metal foil 31 and the resin-coated film 41 may be provided with a cover film or the like, if necessary. Providing a cover film can prevent the incorporation of foreign matter. The cover film is not particularly limited, but examples include polyolefin film, polyester film, polymethylpentene film, and films formed by providing a release agent layer on these films.

[0167] The method for producing the resin-coated metal foil 31 is not particularly limited as long as it can produce the resin-coated metal foil 31. Examples of methods for producing the resin-coated metal foil 31 include applying the varnish-like resin composition (resin varnish) onto the metal foil 13 and heating it. The varnish-like resin composition is applied onto the metal foil 13, for example, by using a bar coater. The applied resin composition is heated, for example, at a temperature of 40°C to 180°C for 1 minute to 10 minutes. The heated resin composition is formed on the metal foil 13 as an uncured resin layer 32. The heating can cause the organic solvent to volatilize from the resin varnish, thereby reducing or removing the organic solvent.

[0168] [Resin-coated film] Figure 5 is a schematic cross-sectional view showing an example of a resin-coated film 41 according to this embodiment.

[0169] As shown in Figure 5, the resin-coated film 41 according to this embodiment comprises a resin layer 42 containing the resin composition or a semi-cured product of the resin composition, and a support film 43. This resin-coated film 41 comprises the resin layer 42 and a support film 43 laminated together with the resin layer 42. The resin-coated film 41 may also have other layers between the resin layer 42 and the support film 43.

[0170] Furthermore, the resin layer 42 may contain a semi-cured product of the resin composition as described above, or it may contain the uncured resin composition. That is, the resin-coated film 41 may comprise a resin layer containing a semi-cured product of the resin composition (the resin composition of stage B) and a support film, or it may comprise a resin layer containing the uncured resin composition (the resin composition of stage A) and a support film. Furthermore, the resin layer may contain the resin composition or a semi-cured product of the resin composition, and may or may not contain a fibrous substrate. Furthermore, the resin composition or the semi-cured product of the resin composition may be the resin composition that has been dried or heat-dried. Furthermore, the fibrous substrate may be the same as the fibrous substrate of the prepreg.

[0171] Furthermore, the support film 43 can be any support film used for resin-coated films without limitation. Examples of such support films include polyester film, polyethylene terephthalate (PET) film, polyimide film, polyparabanic acid film, polyether ether ketone film, polyphenylene sulfide film, polyamide film, polycarbonate film, and electrically insulating films such as polyarylate film.

[0172] The resin-coated film 41 may be provided with a cover film or the like, if necessary. Providing a cover film can prevent the incorporation of foreign matter. The cover film is not particularly limited, but examples include polyolefin film, polyester film, and polymethylpentene film.

[0173] The support film and cover film may be subjected to surface treatments such as matte treatment, corona treatment, release treatment, and roughening treatment, as needed.

[0174] The method for manufacturing the resin-coated film 41 is not particularly limited as long as it can be manufactured. Examples of methods for manufacturing the resin-coated film 41 include applying the varnish-like resin composition (resin varnish) onto a support film 43 and heating it. The varnish-like resin composition is applied onto the support film 43, for example, by using a bar coater. The applied resin composition is heated, for example, at a temperature of 40°C to 180°C for 1 minute to 10 minutes. The heated resin composition is formed on the support film 43 as an uncured resin layer 42. The heating can cause the organic solvent to volatilize from the resin varnish, thereby reducing or removing the organic solvent.

[0175] The prepregs, resin-coated films, and resin-coated metal foils obtained using the resin composition of this embodiment are extremely useful for industrial applications because, in their cured form, they have a high dielectric constant, a low dielectric loss tangent, a high glass transition temperature (Tg), good adhesion, and excellent film properties. Furthermore, metal-clad laminates and wiring boards equipped with an insulating layer containing the cured resin composition of this embodiment also possess these excellent properties.

[0176] This specification discloses various aspects of technology as described above, but the main technologies are summarized below.

[0177] A resin composition according to a first aspect of the present invention is a resin composition containing a reactive compound (A) having at least one of a vinylphenyl group or a (meth)acrylate group, a crosslinking agent (B) which is a compound different from the reactive compound (A), a high molecular weight material (C) having a weight-average molecular weight of 10,000 to 1,500,000, and an inorganic filler (D); the content of the high molecular weight material (C) is more than 30% by mass and 50% by mass or less with respect to the total amount of resin components of the resin composition; the inorganic filler (D) contains a titanate compound filler (D-1); and the content of the titanate compound filler (D-1) is 100 parts by mass or more and 400 parts by mass or less with respect to 100 parts by mass of the total amount of resin components of the resin composition.

[0178] The resin composition according to the second aspect of the present invention is the resin composition according to the first aspect, wherein the high molecular weight material (C) comprises at least one of styrene copolymers and acrylic copolymers.

[0179] In the third aspect of the present invention, the resin composition of the first or second aspect contains a high molecular weight substance (C) in an amount of 50 parts by mass or more and 130 parts by mass or less, based on 100 parts by mass of the total of the reactive compound (A) and the crosslinking agent (B).

[0180] A fourth aspect of the present invention is a resin composition in any of the first to third aspects, wherein the titanate compound (D-1) comprises at least one selected from the group consisting of strontium titanate particles, barium titanate particles, calcium titanate particles, and titanium oxide particles.

[0181] A fifth aspect of the present invention is a resin composition in which, in any of the first to fourth aspects of the present invention, the number average molecular weight of the reactive compound (A) is 1,000 or more and 8,000 or less.

[0182] A resin composition according to the sixth aspect of the present invention is a resin composition in which, in any of the first to fifth aspects, the reactive compound (A) contains at least one of a modified polyphenylene ether compound and a modified polystyrene compound.

[0183] A resin composition according to the seventh aspect of the present invention is a resin composition that, in any of the first to sixth aspects, contains at least one selected from the group consisting of a polyfunctional allyl compound, a polyfunctional acrylate compound, a polyfunctional methacrylate compound, a polyfunctional vinyl compound, and a polyfunctional maleimide compound.

[0184] The eighth aspect of the present invention is a resin composition in which, in any of the first to seventh aspects, the relative permittivity of the cured product of the resin composition at a frequency of 10 GHz is 5 to 12.

[0185] A prepreg according to the ninth aspect of the present invention comprises a resin composition according to any of the first to eighth aspects or a semi-cured product of the resin composition, and a fibrous substrate.

[0186] A resin-coated film according to the tenth aspect of the present invention comprises a resin layer containing a resin composition according to any of the first to eighth aspects or a semi-cured product of the resin composition, and a support film.

[0187] A resin-coated metal foil according to the eleventh aspect of the present invention comprises a resin layer containing a resin composition according to any of the first to eighth aspects or a semi-cured product of the resin composition, and a metal foil.

[0188] A metal-clad laminate according to the twelfth aspect of the present invention comprises an insulating layer containing a cured product of any of the first to eighth aspects of the resin composition or a cured product of the ninth aspect of the prepreg, and a metal foil.

[0189] A wiring board according to the thirteenth aspect of the present invention comprises an insulating layer containing a cured resin composition of any of the first to eighth aspects or a cured prepreg of the ninth aspect, and wiring.

[0190] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited thereto.

[0191] [Examples 1-6 and Comparative Examples 1-3] In these examples, each component used in preparing the resin composition will be described.

[0192] <Reactive Compounds (A)> ・PPE1: Polyphenylene ether compound with methacryloyl groups at the ends (SA9000 manufactured by SABIC Innovative Plastics, number average molecular weight Mn 1700, number of terminal functional groups 2) ・PPE2: Polyphenylene ether compound with vinylbenzyl groups at the ends (OPE-2St 2200 manufactured by Mitsubishi Gas Chemical Company, number average molecular weight 2200, number of terminal functional groups 2) ・PPE3: Polyphenylene ether compound with vinylbenzyl groups at the ends (OPE-2St 1200 manufactured by Mitsubishi Gas Chemical Company, number average molecular weight 1200, number of terminal functional groups 2)

[0193] <Crosslinking agent (B)> - Allyl compound: Triallyl isocyanurate (TAIC manufactured by Nippon Kasei Co., Ltd.) - Maleimide compound: Polyfunctional maleimide compound (solids in MIR-5000-60T (toluene-dissolved maleimide compound) manufactured by Nippon Kayaku Co., Ltd.) - Methacrylate compound: Tricyclodecane dimethanol dimethacrylate (DCP manufactured by Shin Nakamura Chemical Industry Co., Ltd.)

[0194] <High Molecular Weight Materials (C)> • High Molecular Weight Material 1: Hydrogenated styrene (ethylene / butylene) styrene block copolymer (Asahi Kasei Corporation's "ToughTec® H1221", weight-average molecular weight Mw 150,000, solid at 25°C) • High Molecular Weight Material 2: α-methylstyrene / styrene copolymer (Mitsui Chemicals, Inc.'s "FTR2140", weight-average molecular weight Mw 3,200)

[0195] <Inorganic Filler (D)> (Titanium Titanate Compound Filler (D-1)) - Strontium titanate particles: "ST-H100" manufactured by Kyoritsu Material Co., Ltd., average particle size (D50) 1.32 μm, specific gravity 5.1 g / cm³ ３ ) (Other inorganic fillers (D-2): Silica filler) ・Spherical silica particles: "SC2300-SVJ" manufactured by Admatex Co., Ltd. (average particle size (D50) 0.5 μm, specific gravity 2.3 g / cm³) ３ )

[0196] <Other elastomers> ・Polybutadiene 1: Liquid epoxy group-containing polybutadiene, manufactured by Nippon Soda Co., Ltd. "JP-100" ・Polybutadiene 2: Liquid 1,2-polybutadiene, manufactured by Nippon Soda Co., Ltd. "B-1000"

[0197] <Other ingredients> - Flame retardant: Diphenylphosphine oxide compound, a non-miscible phosphorus-based flame retardant, manufactured by Jin-I Chemical Co., Ltd., "PQ60" - Reaction initiator: Peroxide (α,α'-di(t-butylperoxy)diisopropylbenzene, manufactured by NOF Corporation, "Perbutyl P (PBP)") - Reaction accelerator: Imidazole-based reaction accelerator, 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemicals, Ltd., "2E4MZ")

[0198] (Preparation Method) First, each component except the inorganic filler and the incompatible flame retardant was added to toluene (solvent) in parts by mass according to the composition shown in Table 1, so that the solid content concentration was 35% by mass, and the mixture was mixed. The mixture was stirred for 60 minutes. Then, the inorganic filler and the incompatible flame retardant (parts by mass) were added to the resulting liquid in the proportions shown in Table 1, and the amount of toluene (solvent) added was adjusted so that the solid content concentration of the dispersed resin composition was 50 parts by mass. The mixture was then stirred for 60 minutes to perform primary dispersion of the filler. Subsequently, the inorganic filler was secondary dispersed using a bead mill to obtain a varnish-like resin composition (varnish).

[0199] Next, an evaluation substrate (cured resin-coated metal foil) for evaluating the glass transition temperature, dielectric properties, and copper foil peel strength was obtained as follows.

[0200] The obtained varnish was applied to a metal foil (copper foil, 3EC-VLP manufactured by Mitsui Mining & Smelting Co., Ltd., 12 μm thick) to a thickness of 30 μm, and heated at 100°C for 3 minutes to obtain resin-coated metal foil. Two of the obtained resin-coated metal foils were then stacked so that the resin layers were in contact with each other. This was used as a pressure substrate, and heated and pressurized under vacuum at 200°C and a pressure of 3 MPa for 2 hours to produce a cured resin layer of the resin-coated metal foil (metal-clad laminate). This was used as the evaluation substrate (cured resin-coated metal foil).

[0201] <Evaluation Test>

[0202] [Dielectric Properties (Relative Permittivity, Dielectric Loss Tangent)] Unclad plates, obtained by etching off copper foil from an evaluation substrate (metal-clad laminate), were used as test specimens. The relative permittivity (Dk) and dielectric loss tangent (Df) of the cured resin composition at 10 GHz were measured using the cavity resonator perturbation method. Specifically, a network analyzer (N5230A, manufactured by Keysight Technologies, Inc.) was used to measure the relative permittivity and dielectric loss tangent of the evaluation substrate at 10 GHz. The acceptance criteria for this test were Dk ≥ 5 and Df ≤ 0.005.

[0203] [Glass Transition Temperature (Tg)] Unclad plates, obtained by etching away copper foil from an evaluation substrate (metal-clad laminate), were used as test specimens. The Tg of the cured resin composition was measured using a viscoelastic spectrometer "DMS6100" manufactured by Seiko Instruments Inc. Dynamic viscoelasticity measurement (DMA) was performed using a tensile module at a frequency of 10 Hz. The temperature at which tanδ was maximum when the temperature was raised from room temperature to 320°C at a heating rate of 5°C / min was defined as Tg (°C). In this test, a Tg of 220°C or higher was considered acceptable.

[0204] [Adhesion] The copper foil was peeled off the evaluation substrate (metal-clad laminate), and the peel strength was measured in accordance with JIS C 6481 (1996). Specifically, the evaluation substrate was made 10 mm wide x 100 mm long, and the copper foil was peeled off at a speed of 50 mm / min using a tensile testing machine, and the peel strength (N / mm) at that time was measured. This peel strength is the copper foil peel strength, and it was found that the higher this value, the better the adhesion of the metal foil (copper foil). In this test, a peel strength of 0.40 N / mm or higher was judged to be acceptable.

[0205] [Film Performance] A resin-coated metal foil was cut with a utility knife. If the resin layer at the resulting fracture surface crumbled and powder from the resin composition fell off, it was deemed a "failure." If the cross-section did not crumble and no powder fell off was observed, it was deemed a "pass."

[0206] The results for each of the above evaluations are shown in Table 1.

[0207]

[0208] (Discussion) As can be seen from Table 1, in all of the examples using the resin composition of the present invention, it was possible to obtain cured products with a high relative permittivity, low dielectric loss tangent, and high Tg, and it was confirmed that a resin composition with film performance and adhesion to metal foil can be provided.

[0209] On the other hand, in Comparative Example 1, where the amount of titanate compound filler (D-1) was too low, a sufficiently high dielectric constant could not be obtained. Furthermore, in Comparative Example 2, where the content of the high molecular weight material (C) was insufficient, the dielectric loss tangent became high, and the film performance was also inferior. In addition, in Comparative Example 3, which used a high molecular weight material (C) with a low molecular weight, a sufficiently high Tg could not be obtained, and furthermore, the adhesion and film performance were also inferior.

[0210] This application is based on Japanese Patent Application No. 2025-056102, filed on 28 March 2025, the contents of which are included in this application.

[0211] In order to express the present invention, the invention has been adequately and sufficiently described above through embodiments with reference to specific examples and drawings, etc. However, those skilled in the art should recognize that it is easy to modify and / or improve the embodiments described above. Therefore, unless the modifications or improvements implemented by those skilled in the art fall outside the scope of the claims described in the claims, such modifications or improvements shall be interpreted as being included within the scope of the claims.

[0212] The present invention has broad industrial applicability in the technical fields related to electronic materials, electronic devices, optical devices, and the like.

Claims

1. A resin composition comprising a reactive compound (A) containing at least one of a vinylphenyl group or a (meth)acrylate group, a crosslinking agent (B) which is a compound different from the reactive compound (A), a high molecular weight material (C) having a weight-average molecular weight of 10,000 or more and 1,500,000 or less, and an inorganic filler (D), wherein the content of the high molecular weight material (C) is more than 30% by mass and 50% by mass or less based on the total amount of resin components of the resin composition, and the inorganic filler (D) contains a titanate compound filler (D-1), wherein the content of the titanate compound filler (D-1) is 100 parts by mass or more and 400 parts by mass or less based on 100 parts by mass of the total amount of resin components of the resin composition.

2. The resin composition according to claim 1, wherein the high molecular weight material (C) comprises at least one of a styrene copolymer and an acrylic copolymer.

3. The resin composition according to claim 1, wherein the content of the high molecular weight substance (C) is 50 parts by mass or more and 130 parts by mass or less, based on 100 parts by mass of the total of the reactive compound (A) and the crosslinking agent (B).

4. The resin composition according to claim 1, wherein the titanate compound (D-1) comprises at least one selected from the group consisting of strontium titanate particles, barium titanate particles, calcium titanate particles, and titanium oxide particles.

5. The resin composition according to claim 1, wherein the number average molecular weight of the reactive compound (A) is 1,000 or more and 8,000 or less.

6. The resin composition according to claim 1, wherein the reactive compound (A) comprises at least one of a modified polyphenylene ether compound and a modified polystyrene compound.

7. The resin composition according to claim 1, wherein the crosslinking agent (B) comprises at least one selected from the group consisting of polyfunctional allyl compounds, polyfunctional acrylate compounds, polyfunctional methacrylate compounds, polyfunctional vinyl compounds, and polyfunctional maleimide compounds.

8. The resin composition according to claim 1, wherein the relative permittivity of the cured product of the resin composition at a frequency of 10 GHz is 5 to 12.

9. A prepreg comprising a resin composition according to any one of claims 1 to 8 or a semi-cured product of the resin composition, and a fibrous substrate.

10. A resin-coated film comprising a resin layer containing the resin composition according to any one of claims 1 to 8 or a semi-cured product of the resin composition, and a support film.

11. A resin-coated metal foil comprising a resin layer containing the resin composition according to any one of claims 1 to 8 or a semi-cured product of the resin composition, and a metal foil.

12. A metal-clad laminate comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 8, and a metal foil.

13. A wiring board comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 8, and wiring.

14. A metal-clad laminate comprising an insulating layer containing a cured prepreg according to claim 9, and a metal foil.

15. A wiring board comprising an insulating layer containing a cured prepreg according to claim 9, and wiring.

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