JP7279716B2 - Resin composition, prepreg, metal foil clad laminate, resin sheet and printed wiring board - Google Patents

Description

The present invention relates to a resin composition, a prepreg using the resin composition, a metal foil clad laminate and a resin sheet using the resin composition or the prepreg, and a printed wiring board using these.

2. Description of the Related Art In recent years, semiconductors used in electronic devices, communication devices, personal computers, and the like are becoming increasingly highly integrated and miniaturized. Along with this, various characteristics required for semiconductor package laminates (for example, metal foil-clad laminates) used for printed wiring boards are becoming more and more severe. Desired properties include, for example, high glass transition temperature, heat resistance, high copper foil peel strength, low dielectric constant, low dielectric loss tangent, low thermal expansion, and low water absorption. Insulator materials with high dielectric constant and dielectric loss tangent, among others, attenuate electrical signals and impair reliability, so materials with low dielectric constant and dielectric loss tangent are required. Furthermore, since multilayer printed wiring boards have a problem of increasing warpage, low thermal expansion properties of insulator materials are also important.

In order to obtain printed wiring boards with improved properties, resin compositions used as materials for printed wiring boards have been investigated. For example, in Patent Document 1, a saturated thermoplastic elastomer having a styrene unit, an epoxy resin, a cyanate ester resin, and a polybutadiene are disclosed as films exhibiting good dielectric properties in a high frequency range while ensuring compatibility of resin components. It discloses a combination of at least one thermosetting resin selected from the group consisting of a resin and a maleimide compound, and a resin component including a curing agent and a curing accelerator, in a predetermined ratio.

In Patent Document 2, a vinyl compound having a specific structure and a bismaleimide resin having a specific structure are used as a resin composition that has a low dielectric constant and a low dielectric loss tangent and exhibits high adhesive strength to LCP films and copper foils. and a polyolefin-based elastomer as constituent components, which are combined in a predetermined ratio.

Japanese Patent No. 5724503 JP 2016-117554 A

Examples of Patent Document 1 include a resin containing a saturated thermoplastic elastomer having a styrene unit and at least one thermosetting resin selected from the group consisting of epoxy resins, cyanate ester resins, polybutadiene resins and maleimide compounds. It is disclosed that a film having excellent dielectric properties in a high frequency region can be provided by producing a film using the composition by a predetermined method. However, the elastomer ratio is high and there is no description of the glass transition temperature.

On the other hand, Patent Document 2 describes an example of an adhesive using a resin composition containing a vinyl compound having a specific structure, a bismaleimide resin having a specific structure, and a polyolefin elastomer. , excellent copper foil peel strength, low dielectric constant and low dielectric loss tangent. However, even in this document, there is no description regarding the glass transition temperature.

Therefore, the object of the present invention is to provide excellent low dielectric constant, low dielectric loss tangent, high glass transition temperature, and high metal foil (copper foil) when used for printed wiring board materials (for example, metal foil clad laminates). An object of the present invention is to provide a resin composition, a prepreg, a metal foil-clad laminate, a resin sheet, and a printed wiring board that simultaneously achieve peel strength.

As a result of intensive studies on the above problems, the present inventors have found that the maleimide compound (A) having no siloxane bond, the unmodified cyanate ester compound (B) and the styrene content are 17% by mass or more, and , at least one selected from the group consisting of an elastomer (C1) having a styrene structure at both ends and a silicone (C2) having a maleimide structure at both ends of a specific structure, and the mass of (C1) and (C2) When combined so that the sum of is 5 to 25 parts by mass with respect to 100 parts by mass of the resin solid content, the resulting resin composition is a material for printed wiring boards (e.g., laminates, metal foil clad laminates), etc. The present inventors have found that, when used in the present invention, simultaneously achieve excellent low dielectric constant, low dielectric loss tangent, high glass transition temperature, and high metal foil (copper foil) peel strength.

（上記式（４）中、Ｒ_５は各々独立して、炭素数１～１２の非置換又は置換の１価の炭化水素基を示し、全てのＲ_５のうちメチル基であるＲ_５の割合が５０モル％以上であり、ｎ_３は０～２の整数を示す。）
［２］
前記シロキサン結合を有しないマレイミド化合物（Ａ）が、下記式（１）で表されるマレイミド化合物、下記式（２）で表されるマレイミド化合物及び下記式（３）で表されるマレイミド化合物からなる群より選ばれる少なくとも１種を含有する、［１］に記載の樹脂組成物。

（上記式（１）中、Ｒ_１は各々独立に水素原子又はメチル基を示し、ｎ_１は１以上の整数を示す。）

（上記式（２）中、Ｒ_２は各々独立に、水素原子、炭素数１～８のアルキル基又はフェニル基を示し、ｎ_２は１以上１０以下の整数を示す。）

（上記式（３）中、Ｒ_３は各々独立に水素原子、メチル基又はエチル基を示し、Ｒ_４は各々独立に水素原子又はメチル基を示す。）
［３］
前記変性されていないシアン酸エステル化合物（Ｂ）が、フェノールノボラック型シアン酸エステル化合物、ナフトールアラルキル型シアン酸エステル化合物、ナフチレンエーテル型シアン酸エステル化合物、ビスフェノールＡ型シアン酸エステル化合物、ビスフェノールＭ型シアン酸エステル化合物、ジアリルビスフェノールＡ型シアン酸エステル化合物からなる群より選ばれる少なくとも１種を含有する、［１］又は［２］に記載の樹脂組成物。
［４］
前記スチレン含有量が１７質量％以上であり、かつ、両末端にスチレン構造を有するエラストマー（Ｃ１）が、スチレン－ブタジエンブロック共重合体、スチレン－イソプレンブロック共重合体、スチレン－水添ブタジエンブロック共重合体、スチレン－水添イソプレンブロック共重合体、スチレン－水添（イソプレン／ブタジエン）ブロック共重合体からなる群より選ばれる少なくとも１種を含有するものである、［１］～［３］のいずれか一つに記載の樹脂組成物。
［５］
さらに、充填材（Ｄ）を含有する、［１］～［４］のいずれか一つに記載の樹脂組成物。
［６］
前記充填材（Ｄ）の含有量が、樹脂組成物中の樹脂固形分１００質量部に対して５０～３００質量部である、［５］に記載の樹脂組成物。
［７］
基材と、［１］～［６］いずれか一つに記載の樹脂組成物から形成された、プリプレグ。
［８］
１枚以上重ねた［７］に記載のプリプレグと、前記プリプレグの片面又は両面に配置した金属箔とを含む金属箔張積層板。
［９］
支持体と、前記支持体の表面に配置した［１］～［６］のいずれか一つに記載の樹脂組成物から形成される層とを含む、樹脂シート。
［１０］
絶縁層と、前記絶縁層の表面に配置した導体層とを含むプリント配線板であって、前記絶縁層が、［１］～［６］のいずれか一つに記載の樹脂組成物から形成された層を含む、プリント配線板。That is, the present invention is as follows.
[1]
A maleimide compound (A) having no siloxane bond, an unmodified cyanate ester compound (B), an elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends, and both ends containing at least one selected from the group consisting of silicones (C2) having a maleimide structure in the sum of the masses of the (C1) and (C2) is 5 to 25 masses per 100 mass parts of the resin solid content and the silicone (C2) having a maleimide structure at both ends contains a maleimide-terminated silicone represented by the following formula (4).

(In formula (4) above, each R ₅ independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and the proportion of R ₅ that is a methyl group among all R ₅ is 50 mol% or more, and n ₃ represents an integer of 0 to 2.)
[2]
The maleimide compound (A) having no siloxane bond consists of a maleimide compound represented by the following formula (1), a maleimide compound represented by the following formula (2), and a maleimide compound represented by the following formula (3). The resin composition according to [1], containing at least one selected from the group.

(In formula (1) above, each R ₁ independently represents a hydrogen atom or a methyl group, and n ₁ represents an integer of 1 or more.)

(In formula (2) above, each R ₂ independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n ₂ represents an integer of 1 or more and 10 or less.)

(In formula (3) above, each _R3 independently represents a hydrogen atom, a methyl group or an ethyl group, and each _R4 independently represents a hydrogen atom or a methyl group.)
[3]
The non-modified cyanate ester compound (B) is a phenol novolak-type cyanate ester compound, a naphthol aralkyl-type cyanate ester compound, a naphthylene ether-type cyanate ester compound, a bisphenol A-type cyanate ester compound, and a bisphenol M-type cyanate ester compound. The resin composition according to [1] or [2], containing at least one selected from the group consisting of cyanate ester compounds and diallyl bisphenol A type cyanate ester compounds.
[4]
The elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends is a styrene-butadiene block copolymer, a styrene-isoprene block copolymer, or a styrene-hydrogenated butadiene block copolymer. polymers, styrene-hydrogenated isoprene block copolymers, and styrene-hydrogenated (isoprene/butadiene) block copolymers, containing at least one selected from the group consisting of [1] to [3]. The resin composition according to any one.
[5]
The resin composition according to any one of [1] to [4], further comprising a filler (D).
[6]
The resin composition according to [5], wherein the content of the filler (D) is 50 to 300 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition.
[7]
A prepreg formed from a substrate and the resin composition according to any one of [1] to [6].
[8]
A metal foil-clad laminate comprising one or more prepregs according to [7], and a metal foil disposed on one or both sides of the prepreg.
[9]
A resin sheet comprising a support and a layer formed from the resin composition according to any one of [1] to [6] disposed on the surface of the support.
[10]
A printed wiring board comprising an insulating layer and a conductor layer disposed on the surface of the insulating layer, wherein the insulating layer is formed from the resin composition according to any one of [1] to [6]. A printed wiring board, comprising:

When the resin composition of the present invention is used as a printed wiring board material (e.g., laminate, metal foil-clad laminate), etc., excellent low dielectric constant, low dielectric loss tangent, high glass transition temperature, high metal foil ( It is possible to realize prepregs, metal foil-clad laminates, resin sheets, and printed wiring boards that simultaneously achieve peel strength (copper foil), and its industrial practicality is extremely high.

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention (hereinafter referred to as "this embodiment") will be described in detail below. The following embodiments are examples for explaining the present invention, and the present invention is not limited only to these embodiments.

[Resin composition]
The resin composition according to the present embodiment contains a maleimide compound (A) having no siloxane bond, an unmodified cyanate ester compound (B), and a styrene content of 17% by mass or more, and has styrene at both ends. containing at least one selected from the group consisting of an elastomer (C1) having a structure and a silicone (C2) having a maleimide structure at both ends, and the sum of the masses of the (C1) and (C2) is the resin solid content 5 to 25 parts by mass per 100 parts by mass of the silicone (C2) having a maleimide structure at both ends contains the maleimide-terminated silicone represented by formula (4). Since the resin composition according to the present embodiment has the above-described structure, when it is used as a printed wiring board material (for example, a laminate, a metal foil-clad laminate), etc., it has excellent low dielectric constant and low dielectric loss tangent. high glass transition temperature and high metal foil (copper foil) peel strength can be achieved at the same time.

[Maleimide compound (A) having no siloxane bond]
The resin composition according to this embodiment contains a maleimide compound (A) having no siloxane bond. The maleimide compound (A) having no siloxane bond according to the present embodiment is not particularly limited as long as it is a maleimide compound having one or more maleimide groups in the molecule and having no siloxane bond. , Specific examples include N-phenylmaleimide, N-hydroxyphenylmaleimide, bis(4-maleimidophenyl)methane, 2,2-bis{4-(4-maleimidophenoxy)-phenyl}propane, 4, 4′-diphenylmethanebismaleimide, bis(3,5-dimethyl-4-maleimidophenyl)methane, bis(3,5-diethyl-4-maleimidophenyl)methane, phenylmethanemaleimide, o-phenylenebismaleimide, m-phenylene bismaleimide, p-phenylenebismaleimide, o-phenylenebiscitraconimide, m-phenylenebiscitraconimide, p-phenylenebiscitraconimide, 2,2-bis(4-(4-maleimidophenoxy)-phenyl)propane, 3 ,3′-dimethyl-5,5′-diethyl-4,4′-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl) Hexane, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, 4,4 '-diphenylmethanebiscitraconimide, 2,2-bis[4-(4-citraconimidophenoxy)phenyl]propane, bis(3,5-dimethyl-4-citraconimidophenyl)methane, bis(3-ethyl-5- methyl-4-citraconimidophenyl)methane, bis(3,5-diethyl-4-citraconimidophenyl)methane, maleimide compounds represented by the above formulas (1), (2) and (3), and the like. .
Among these, the maleimide compounds represented by the formulas (1), (2) and (3) are particularly preferable in terms of low thermal expansion and improved heat resistance, and the maleimide compound represented by the formula (1) is more preferable. .
The maleimide compounds may be used alone or in combination of two or more.

In formula (1), each R ₁ independently represents a hydrogen atom or a methyl group, preferably a hydrogen atom. In formula (1), n ₁ represents an integer of 1 or more, and the upper limit of n ₁ is usually 10, preferably 7, more preferably 7, from the viewpoint of solubility in organic solvents. 5. The maleimide compound (A) having no siloxane bond may be a mixture of two or more compounds having different _n1 values.

In the above formula (2), each R ₂ is independently a hydrogen atom, an alkyl group having 1 to 8 carbon atoms (e.g., methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group , t-butyl group, n-pentyl group, etc.), or a phenyl group. Among these, from the viewpoint of improving flame resistance and metal foil (copper foil) peel strength, it is preferably a group selected from the group consisting of a hydrogen atom, a methyl group, and a phenyl group. One is more preferred, and a hydrogen atom is even more preferred.

In the formula (2), 1≦n ₂ ≦10. _n2 is preferably 4 or less, more preferably 3 or less, and even more preferably 2 or less from the viewpoint of further excellent solvent solubility. Also, the maleimide compound (A) having no siloxane bond may be a mixture of two or more compounds having different _n2 values.

In formula (3), each R ₃ independently represents a hydrogen atom, a methyl group or an ethyl group, and each R ₄ independently represents a hydrogen atom or a methyl group. R ₃ is preferably a methyl group or an ethyl group from the viewpoint of further superior low dielectric constant and low dielectric loss tangent properties.

As the maleimide compound (A) having no siloxane bond used in the present embodiment, a commercially available one may be used. For example, the maleimide compound represented by formula (1) "BMI -2300", "MIR-3000" manufactured by Nippon Kayaku Co., Ltd. as the maleimide compound represented by formula (2), and "BMI-70" manufactured by Daiwa Kasei Kogyo Co., Ltd. as the maleimide compound represented by formula (3). It can be used preferably.

The content of the maleimide compound (A) having no siloxane bond in the resin composition according to the present embodiment can be appropriately set according to desired properties, and is not particularly limited. The content of the maleimide compound (A) having no siloxane bond is preferably 1 part by mass or more, more preferably 5 parts by mass or more, when the resin solid content in the resin composition is 100 parts by mass. It is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and may be 20 parts by mass or more. The upper limit of the content of the maleimide compound (A) having no siloxane bond is preferably 90 parts by mass or less, more preferably 60 parts by mass or less, and 40 parts by mass or less. More preferably, it may be 35 parts by mass or less, or 30 parts by mass or less. By setting it as the said range, there exists a tendency for high heat resistance and low water absorption to improve more.
The resin composition according to the present embodiment may contain only one type of maleimide compound (A) having no siloxane bond, or may contain two or more types. When two or more types are included, the total amount is preferably within the above range.

Here, unless otherwise specified, the term "resin solid content in the resin composition" refers to the components of the resin composition excluding the solvent and the filler (D), and the resin solid content of 100 parts by mass is , the total amount of the components excluding the solvent and the filler (D) in the resin composition is 100 parts by mass.

[Unmodified cyanate ester compound (B)]
The resin composition according to this embodiment contains an unmodified cyanate ester compound (B). The unmodified cyanate ester compound (B) used in the present embodiment is a compound or resin having an aromatic moiety substituted with at least one cyanato group (cyanate ester group) in the molecule, and The cyanato group in the molecule does not have a group reacted with other functional groups (for example, maleimide group) other than the cyanato group and the phenolic hydroxyl group. That is, "unmodified" means that the cyanato group in the molecule does not have a group that has reacted with other functional groups (for example, maleimide group) other than the cyanato group and the phenolic hydroxyl group.
An example of the resin composition according to the present embodiment is varnish. It goes without saying that part or all of it may react with the cyanato groups of other cyanate ester compound (B) molecules or with functional groups possessed by other resin components.
Further, the unmodified cyanate ester compound (B) according to the present embodiment, within the scope of the present invention, has a cyanato group that is a cyanato group of another cyanate ester compound (B) molecule, Alternatively, it may contain a small amount of a component that has reacted with the phenolic hydroxyl group of the raw material phenol compound.

According to this embodiment, the resin composition has a styrene content of 17% by mass or more and is composed of an elastomer (C1) having a styrene structure at both ends and a silicone (C2) having a maleimide structure at both ends. By containing at least one selected from the group, for example, it is believed that the heat curing reaction in the maleimide compound (A) having no siloxane bond and the unmodified cyanate ester compound (B) proceeds more easily. be done. Therefore, it is presumed that a high glass transition temperature can be achieved even when the cyanate ester compound (B) that is not modified is used.

（式（５）中、Ａｒ_１は、各々独立に、置換基を有してもよいフェニレン基、置換基を有してもよいナフチレン基又は置換基を有してもよいビフェニレン基を表す。Ｒ_６は各々独立に水素原子、置換基を有してもよい炭素数１～６のアルキル基、置換基を有してもよい炭素数６～１２のアリール基、置換基を有してもよい炭素数１～４のアルコキシ基、炭素数１～６のアルキル基と炭素数６～１２のアリール基とが結合した置換基を有してもよいアラルキル基又は炭素数１～６のアルキル基と炭素数６～１２のアリール基とが結合した置換基を有してもよいアルキルアリール基のいずれか１種から選択される。ｎ_４はＡｒ_１に結合するシアナト基の数を表し、１～３の整数である。ｎ_５はＡｒ_１に結合するＲ_６の数を表し、Ａｒ_１がフェニレン基の場合は４－ｎ_４、ナフチレン基の場合は６－ｎ_４、ビフェニレン基の場合は８－ｎ_４である。ｎ_６は平均繰り返し数を表し、０～５０の整数である。変性されていないシアン酸エステル化合物（Ｂ）は、ｎ_５及び／又はｎ_６が異なる化合物の混合物であってもよい。Ｚは、各々独立に、単結合、炭素数１～５０の２価の有機基（水素原子がヘテロ原子に置換されていてもよい）、窒素数１～１０の２価の有機基（－Ｎ－Ｒ－Ｎ－など）、カルボニル基（－ＣＯ－）、カルボキシ基（－Ｃ（＝Ｏ）Ｏ－）、カルボニルジオキサイド基（－ＯＣ（＝Ｏ）Ｏ－）、スルホニル基（－ＳＯ_２－）、及び、２価の硫黄原子又は２価の酸素原子のいずれか１種から選択される。）Examples of the non-modified cyanate ester compound (B) according to the present embodiment include those represented by the following formula (5).

(In formula (5), each Ar ₁ independently represents a phenylene group optionally having a substituent, a naphthylene group optionally having a substituent, or a biphenylene group optionally having a substituent. Each R ₆ is independently a hydrogen atom, an optionally substituted C 1-6 alkyl group, an optionally substituted C 6-12 aryl group, optionally substituted an alkoxy group having 1 to 4 carbon atoms, an aralkyl group optionally having a substituent in which an alkyl group having 1 to 6 carbon atoms and an aryl group having 6 to 12 carbon atoms are bonded, or an alkyl group having 1 to 6 carbon atoms; and an aryl group having 6 to 12 carbon atoms, and _{n 4} represents the number of cyanato groups bonded to Ar ₁ , and 1 is an integer of up to 3. n ₅ represents the number of R ₆ bonded to Ar ₁ , 4-n 4 when Ar ₁ is a phenylene group, 6-n ₄ when it is a naphthylene group, and 6-n ₄ when it is a biphenylene group. 8-n _4. n ₆ represents the average repeating number and is an integer from 0 to 50. The unmodified cyanate ester compound (B) is a mixture of compounds with different n ₅ and / or n ₆ Each Z is independently a single bond, a divalent organic group having 1 to 50 carbon atoms (a hydrogen atom may be substituted with a heteroatom), a divalent Organic group (-N-R-N- etc.), carbonyl group (-CO-), carboxy group (-C(=O)O-), carbonyl dioxide group (-OC(=O)O-), sulfonyl group (—SO ₂ —), and any one of a divalent sulfur atom and a divalent oxygen atom.)

The alkyl group for R ₆ in formula (5) may have a linear structure, a branched structure, or a cyclic structure (such as a cycloalkyl group). Further, the hydrogen atom in the alkyl group in formula (5) and the aryl group in R ₆ may be substituted with a halogen atom such as a fluorine atom or a chlorine atom, an alkoxy group such as a methoxy group or a phenoxy group, a cyano group, or the like. good.
Specific examples of alkyl groups include methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, 1-ethylpropyl and 2,2-dimethylpropyl. group, cyclopentyl group, hexyl group, cyclohexyl group, trifluoromethyl group and the like.
Specific examples of aryl groups include phenyl, xylyl, mesityl, naphthyl, phenoxyphenyl, ethylphenyl, o-, m- or p-fluorophenyl, dichlorophenyl, dicyanophenyl and trifluorophenyl. group, methoxyphenyl group, o-, m- or p-tolyl group, and the like.
Specific examples of alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, n-butoxy, isobutoxy and tert-butoxy groups.
Specific examples of the divalent organic group for Z in formula (5) include a methylene group, an ethylene group, a trimethylene group, a cyclopentylene group, a cyclohexylene group, a trimethylcyclohexylene group, a biphenylylmethylene group, and dimethylmethylene-phenylene. -dimethylmethylene group, fluorenediyl group, phthalidodiyl group and the like. A hydrogen atom in the divalent organic group may be substituted with a halogen atom such as a fluorine atom or a chlorine atom, an alkoxy group such as a methoxy group or a phenoxy group, a cyano group, or the like. Examples of the divalent organic group having 1 to 10 nitrogen atoms in Z of formula (5) include an imino group and a polyimide group.

（式（６）中、Ａｒ_２はフェニレン基、ナフチレン基及びビフェニレン基のいずれか１種から選択される。Ｒ_７、Ｒ_８、Ｒ_１１、Ｒ_１２は各々独立に水素原子、炭素数１～６のアルキル基、炭素数６～１２のアリール基、並びに、トリフルオロメチル基及びフェノール性ヒドロキシ基の少なくとも１つにより置換されたアリール基のいずれか１種から選択される。Ｒ_９、Ｒ_１０は各々独立に水素原子、炭素数１～６のアルキル基、炭素数６～１２のアリール基、炭素数１～４のアルコキシ基及びヒドロキシ基のいずれか１種から選択される。ｎ_７は０～５の整数を示すが、変性されていないシアン酸エステル化合物（Ｂ）は、ｎ_７が異なる式（６）で表される基を有する化合物の混合物であってもよい。）

（式（７）中、Ａｒ_３はフェニレン基、ナフチレン基又はビフェニレン基のいずれか１種から選択される。Ｒ_１３、Ｒ_１４は各々独立に水素原子、炭素数１～６のアルキル基、炭素数６～１２のアリール基、ベンジル基、炭素数１～４のアルコキシ基、並びに、ヒドロキシ基、トリフルオロメチル基及びシアナト基の少なくとも１つにより置換されたアリール基のいずれか１種から選択される。ｎ_８は０～５の整数を示すが、変性されていないシアン酸エステル化合物（Ｂ）は、ｎ_８が異なる式（７）で表される基を有する化合物の混合物であってもよい。）Z in formula (5) includes structures represented by formula (6) or (7) below.

(In Formula (6), Ar ₂ is selected from any one of a phenylene group, a naphthylene group and a biphenylene group. R ₇ , R ₈ , R ₁₁ and R ₁₂ are each independently a hydrogen atom and have 1 to an alkyl group having 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, and an aryl group substituted with at least one of a trifluoromethyl group and a phenolic hydroxy group, R ₉ and R ₁₀ are each independently selected from a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 4 carbon atoms and a hydroxy group, n ₇ is 0 The non-modified cyanate ester compound (B) may be a mixture of compounds having a group represented by formula (6) with different _n7 .)

(In formula (7), Ar ₃ is selected from any one of a phenylene group, a naphthylene group and a biphenylene group. R ₁₃ and R ₁₄ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a carbon selected from any one of an aryl group having a number of 6 to 12, a benzyl group, an alkoxy group having 1 to 4 carbon atoms, and an aryl group substituted with at least one of a hydroxy group, a trifluoromethyl group and a cyanato group; Although n ₈ represents an integer of 0 to 5, the unmodified cyanate ester compound (B) may be a mixture of compounds having groups represented by formula (7) with different n ₈ .)

（式中、ｎ_９は４～７の整数を表す。Ｒ_１５は各々独立に水素原子又は炭素数１～６のアルキル基を表す。）
式（６）のＡｒ_２及び式（７）のＡｒ_３の具体例としては、１，４－フェニレン基、１，３－フェニレン基、４，４’－ビフェニレン基、２，４’－ビフェニレン基、２，２’－ビフェニレン基、２，３’－ビフェニレン基、３，３’－ビフェニレン基、３，４’－ビフェニレン基、２，６－ナフチレン基、１，５－ナフチレン基、１，６－ナフチレン基、１，８－ナフチレン基、１，３－ナフチレン基、１，４－ナフチレン基等が挙げられる。式（６）のＲ_７～Ｒ_１２及び式（７）のＲ_１３、Ｒ_１４におけるアルキル基及びアリール基は式（５）で記載したものと同様である。Furthermore, Z in Formula (5) includes a divalent group represented by the following formula.

(In the formula, n ₉ represents an integer of 4 to 7. Each R ₁₅ independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.)
Specific examples of Ar ₂ in formula (6) and Ar ₃ in formula (7) include a 1,4-phenylene group, a 1,3-phenylene group, a 4,4′-biphenylene group and a 2,4′-biphenylene group. , 2,2′-biphenylene group, 2,3′-biphenylene group, 3,3′-biphenylene group, 3,4′-biphenylene group, 2,6-naphthylene group, 1,5-naphthylene group, 1,6 -naphthylene group, 1,8-naphthylene group, 1,3-naphthylene group, 1,4-naphthylene group and the like. The alkyl group and aryl group for R ₇ to R ₁₂ in formula (6) and R ₁₃ and R ₁₄ in formula (7) are the same as those described for formula (5).

Examples of the cyanate ester compound represented by the formula (5) include a phenol novolak-type cyanate ester compound, a naphthol aralkyl-type cyanate ester compound, a biphenyl aralkyl-type cyanate ester compound, a naphthylene ether-type cyanate ester compound, and xylene. Resin-type cyanate ester compounds, adamantane skeleton-type cyanate ester compounds, bisphenol A-type cyanate ester compounds, bisphenol M-type cyanate ester compounds, diallylbisphenol A-type cyanate ester compounds, and the like.

Specific examples of the cyanate ester compound represented by formula (5) include cyanatobenzene, 1-cyanato-2-, 1-cyanato-3-, or 1-cyanato-4-methylbenzene, 1-cyanato- 2-,1-cyanato-3-, or 1-cyanato-4-methoxybenzene, 1-cyanato-2,3-,1-cyanato-2,4-,1-cyanato-2,5-,1-cyanato -2,6-,1-cyanato-3,4- or 1-cyanato-3,5-dimethylbenzene, cyanatoethylbenzene, cyanatobutylbenzene, cyanatooctylbenzene, cyanatononylbenzene, 2-(4- cyanaphenyl)-2-phenylpropane (cyanate of 4-α-cumylphenol), 1-cyanato-4-cyclohexylbenzene, 1-cyanato-4-vinylbenzene, 1-cyanato-2- or 1-cyanato-3 -chlorobenzene, 1-cyanato-2,6-dichlorobenzene, 1-cyanato-2-methyl-3-chlorobenzene, cyanatonitrobenzene, 1-cyanato-4-nitro-2-ethylbenzene, 1-cyanato-2-methoxy- 4-allylbenzene (eugenol cyanate), methyl (4-cyanatophenyl) sulfide, 1-cyanato-3-trifluoromethylbenzene, 4-cyanatobiphenyl, 1-cyanato-2- or 1-cyanato-4- Acetylbenzene, 4-cyanatobenzaldehyde, 4-cyanatobenzoic acid methyl ester, 4-cyanatobenzoic acid phenyl ester, 1-cyanato-4-acetaminobenzene, 4-cyanatobenzophenone, 1-cyanato-2,6-di -tert-butylbenzene, 1,2-dicyanatobenzene, 1,3-dicyanatobenzene, 1,4-dicyanatobenzene, 1,4-dicyanato-2-tert-butylbenzene, 1,4-dicyanato-2 ,4-dimethylbenzene, 1,4-dicyanato-2,3,4-dimethylbenzene, 1,3-dicyanato-2,4,6-trimethylbenzene, 1,3-dicyanato-5-methylbenzene, 1-cyanato or 2-cyanatonaphthalene, 1-cyanato-4-methoxynaphthalene, 2-cyanato-6-methylnaphthalene, 2-cyanato-7-methoxynaphthalene, 2,2′-dicyanato-1,1′-binaphthyl, 1,3 -,1,4-,1,5-,1,6-,1,7-,2,3-,2,6- or 2,7-dicyanatocinaphthalene, 2,2′- or 4,4 '-dicyanatobiphenyl, 4,4'-dicyanatooctafluorobiphenyl, 2,4'- or 4,4'-dicyanatodiphenylmethane, bis(4-cyanato-3,5-dimethylphenyl)methane, 1,1 -bis(4-cyanatophenyl)ethane, 1,1-bis(4-cyanatophenyl)propane, 2,2-bis(4-cyanatophenyl)propane, 2,2-bis(3-allyl-4) -cyanatophenyl)propane, 2,2-bis(4-cyanato-3-methylphenyl)propane, 2,2-bis(2-cyanato-5-biphenylyl)propane, 2,2-bis(4- anatophenyl)hexafluoropropane, 2,2-bis(4-cyanato-3,5-dimethylphenyl)propane, 1,1-bis(4-cyanatophenyl)butane, 1,1-bis(4-cyanato Phenyl)isobutane, 1,1-bis(4-cyanatophenyl)pentane, 1,1-bis(4-cyanatophenyl)-3-methylbutane, 1,1-bis(4-cyanatophenyl)-2- methylbutane, 1,1-bis(4-cyanatophenyl)-2,2-dimethylpropane, 2,2-bis(4-cyanatophenyl)butane, 2,2-bis(4-cyanatophenyl)pentane, 2,2-bis(4-cyanatophenyl)hexane, 2,2-bis(4-cyanatophenyl)-3-methylbutane, 2,2-bis(4-cyanatophenyl)-4-methylpentane, 2 , 2-bis(4-cyanatophenyl)-3,3-dimethylbutane, 3,3-bis(4-cyanatophenyl)hexane, 3,3-bis(4-cyanatophenyl)heptane, 3,3 -bis(4-cyanatophenyl)octane, 3,3-bis(4-cyanatophenyl)-2-methylpentane, 3,3-bis(4-cyanatophenyl)-2-methylhexane, 3,3 -bis(4-cyanatophenyl)-2,2-dimethylpentane, 4,4-bis(4-cyanatophenyl)-3-methylheptane, 3,3-bis(4-cyanatophenyl)-2- Methylheptane, 3,3-bis(4-cyanatophenyl)-2,2-dimethylhexane, 3,3-bis(4-cyanatophenyl)-2,4-dimethylhexane, 3,3-bis(4 -cyanatophenyl)-2,2,4-trimethylpentane, 2,2-bis(4-cyanatophenyl)-1,1,1,3,3,3-hexafluoropropane, bis(4-cyanato Phenyl)phenylmethane, 1,1-bis(4-cyanatophenyl)-1-phenylethane, bis(4-cyanatophenyl)biphenylmethane, 1,1-bis(4-cyanatophenyl)cyclopentane, 1 , 1-bis(4-cyanatophenyl)cyclohexane, 2,2-bis(4-cyanato-3-isopropylphenyl)propane, 1,1-bis(3-cyclohexyl-4-cyanatophenyl)cyclohexane, bis( 4-cyanatophenyl)diphenylmethane, bis(4-cyanatophenyl)-2,2-dichloroethylene, 1,3-bis[2-(4-cyanatophenyl)-2-propyl]benzene, 1,4-bis [2-(4-cyanatophenyl)-2-propyl]benzene, 1,1-bis(4-cyanatophenyl)-3,3,5-trimethylcyclohexane, 4-[bis(4-cyanatophenyl) methyl]biphenyl, 4,4-dicyanatobenzophenone, 1,3-bis(4-cyanatophenyl)-2-propen-1-one, bis(4-cyanatophenyl) ether, bis(4-cyanatophenyl) ) sulfide, bis(4-cyanatophenyl) sulfone, 4-cyanatobenzoic acid-4-cyanatophenyl ester (4-cyanatophenyl-4-cyanatobenzoate), bis-(4-cyanatophenyl) carbonate, 1,3-bis(4-cyanatophenyl)adamantane, 1,3-bis(4-cyanatophenyl)-5,7-dimethyladamantane, 3,3-bis(4-cyanatophenyl)isobenzofuran-1 (3H)-one (phenolphthalein cyanate), 3,3-bis(4-cyanato-3-methylphenyl)isobenzofuran-1(3H)-one (o-cresolphthalein cyanate), 9,9 -bis(4-cyanatophenyl)fluorene, 9,9-bis(4-cyanato-3-methylphenyl)fluorene, 9,9-bis(2-cyanato-5-biphenylyl)fluorene, tris(4-cyanatophenyl)fluorene, anatophenyl)methane, 1,1,1-tris(4-cyanatophenyl)ethane, 1,1,3-tris(4-cyanatophenyl)propane, α,α,α'-tris(4-cyanato phenyl)-1-ethyl-4-isopropylbenzene, 1,1,2,2-tetrakis(4-cyanatophenyl)ethane, tetrakis(4-cyanatophenyl)methane, 2,4,6-tris(N- methyl-4-cyanatoanilino)-1,3,5-triazine, 2,4-bis(N-methyl-4-cyanatoanilino)-6-(N-methylanilino)-1,3,5-triazine, bis(N- 4-cyanato-2-methylphenyl)-4,4'-oxydiphthalimide, bis(N-3-cyanato-4-methylphenyl)-4,4'-oxydiphthalimide, bis(N-4-cyanato Phenyl)-4,4'-oxydiphthalimide, bis(N-4-cyanato-2-methylphenyl)-4,4'-(hexafluoroisopropylidene)diphthalimide, tris(3,5-dimethyl-4- cyanatobenzyl)isocyanurate, 2-phenyl-3,3-bis(4-cyanatophenyl)phthalimidine, 2-(4-methylphenyl)-3,3-bis(4-cyanatophenyl)phthalimidine, 2- Phenyl-3,3-bis(4-cyanato-3-methylphenyl)phthalimidine, 1-methyl-3,3-bis(4-cyanatophenyl)indolin-2-one, 2-phenyl-3,3-bis (4-cyanatophenyl)indolin-2-one, phenol novolak resin or cresol novolac resin (by a known method, phenol, alkyl-substituted phenol or halogen-substituted phenol and formaldehyde compound such as formalin or paraformaldehyde are mixed in an acidic solution. ), trisphenol novolac resin (hydroxybenzaldehyde and phenol reacted in the presence of an acidic catalyst), fluorene novolac resin (a fluorenone compound and 9,9-bis(hydroxyaryl)fluorenes phenol aralkyl resins, cresol aralkyl resins, naphthol aralkyl resins and biphenyl aralkyl resins (by known methods, such as those represented by Ar ₄ —(CH ₂ Z′) ₂ bis Halogenomethyl compounds and phenolic compounds reacted with or without an acidic catalyst, bis(alkoxymethyl) compounds represented by Ar ₄ —(CH ₂ OR) ₂ and Ar ₄ —(CH ₂ OH) ₂ A bis (hydroxymethyl) compound and a phenol compound represented by the reaction in the presence of an acidic catalyst, or polycondensation of an aromatic aldehyde compound, an aralkyl compound, or a phenol compound), phenol-modified Xylene formaldehyde resin (a reaction of a xylene formaldehyde resin and a phenolic compound in the presence of an acidic catalyst by a known method), modified naphthalene formaldehyde resin (a naphthalene formaldehyde resin and a hydroxy-substituted aromatic compound are reacted by a known method with an acidic catalyst) ), phenol-modified dicyclopentadiene resin, phenolic resin having a polynaphthylene ether structure (by a known method, a polyhydric hydroxy naphthalene compound having two or more phenolic hydroxy groups in one molecule is dehydrated and condensed in the presence of a basic catalyst), and the like, and cyanate esterified by the same method as described above, but are not particularly limited. These cyanate ester compounds may be used alone or in combination of two or more.

Among these, phenol novolak-type cyanate ester compounds, naphthol aralkyl-type cyanate ester compounds, naphthylene ether-type cyanate ester compounds, bisphenol A-type cyanate ester compounds, bisphenol M-type cyanate ester compounds, and diallyl bisphenol-type cyanate ester compounds are used. Preferred are naphthol aralkyl-type cyanate ester compounds.

Cured products of resin compositions using these cyanate ester compounds have excellent properties such as heat resistance and low dielectric properties (low dielectric constant and low dielectric loss tangent).

The content of the unmodified cyanate ester compound (B) in the resin composition according to the present embodiment can be appropriately set according to desired properties, and is not particularly limited. The content of the unmodified cyanate ester compound (B) is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and 30 parts by mass when the resin solid content in the resin composition is 100 parts by mass. The above is more preferable, and it may be 50 parts by mass or more. In addition, the upper limit of the content of the unmodified cyanate ester compound (B) is preferably 90 parts by mass or less, more preferably 70 parts by mass or less, when the resin solid content in the resin composition is 100 parts by mass. preferable. By setting it to such a range, more excellent low dielectric constant property and low dielectric loss tangent property can be achieved.

[Elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends]
The resin composition according to the present embodiment contains an elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends. Such a styrene content (also referred to as "styrene ratio") is preferable from the viewpoint of solvent solubility and compatibility with other compounds. Here, the styrene content is the mass of the styrene unit contained in the elastomer (C1) having a styrene structure at both ends (a) g, and the mass of the entire elastomer (C1) having a styrene structure at both ends (b ) g, it is represented by (a)/(b)×100 (unit: %). The elastomer (C1) having a styrene structure at both ends used in the present embodiment usually has two ends. It is preferable that 90% or more of the terminals have a styrene structure, and it is more preferable that all the terminals have a styrene structure.
The elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends used in the resin composition according to the present embodiment includes a styrene-butadiene-styrene block copolymer, styrene -isoprene-styrene block copolymer, styrene-hydrogenated butadiene-styrene block copolymer, styrene-hydrogenated isoprene-styrene block copolymer, styrene-hydrogenated (isoprene/butadiene)-styrene block copolymer. be done. These elastomers may be used alone or in combination of two or more. By using these elastomers, excellent low dielectric constant, excellent low dielectric loss tangent, and high glass transition temperature can be achieved at the same time.

As the styrene structure of the elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends, styrene having a substituent may be used. Specifically, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene and 4-cyclohexylstyrene can be used.

The upper limit of the styrene content in the elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends is preferably 99% by mass or less, and is 90% by mass or less. is more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 50% by mass or less, and even more preferably 45% by mass or less.

As the elastomer (C1) having a styrene content of 17% by mass or more in the present embodiment and having a styrene structure at both ends, a commercially available product may be used, for example, a styrene-butadiene-styrene block copolymer. includes TR2630 (manufactured by JSR Corporation) and TR2003 (manufactured by JSR Corporation). Styrene-isoprene-styrene block copolymers include SIS5250 (manufactured by JSR Corporation). Examples of the styrene-hydrogenated isoprene-styrene block copolymer include SEPTON2104 (manufactured by Kuraray Co., Ltd.).

In the present embodiment, the content of the elastomer (C1) having a styrene content of 17% by mass or more and having a styrene structure at both ends is such that the sum of the masses of (C1) and (C2) described later is the resin solids It is not particularly limited as long as it is 5 to 25 parts by mass per 100 parts by mass, but from the viewpoint of dielectric constant, dielectric loss tangent, and metal foil (copper foil) peel strength, (C1) is 5 to 20 parts by mass. 5 to 15 parts by mass is particularly preferred. In addition, (C1) and (C2) can be appropriately mixed and used.

[Silicone (C2) having a maleimide structure at both ends]
The silicone (C2) having maleimide structures at both ends in the present embodiment is not particularly limited as long as it is a compound having maleimide structures at both ends of the silicone structure and represented by formula (4). By using silicone (C2) having a maleimide structure at both ends in the present embodiment, a low dielectric constant, a low dielectric loss tangent, and a glass transition temperature are improved while maintaining high flame resistance.

In formula (4), each R ₅ independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, preferably an unsubstituted monovalent hydrocarbon group.

The unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms is not particularly limited, but examples include methyl group, ethyl group, propyl group, butyl group, isopropyl group, isobutyl group, t-butyl group, Alkyl groups such as pentyl group, hexyl group, heptyl group, octyl group and 2-ethylhexyl group, alkenyl groups such as vinyl group, allyl group, butenyl group, pentenyl group and hexenyl group, phenyl group, tolyl group, xylyl group and naphthyl an aryl group such as a biphenyl group, an aralkyl group such as a benzyl group, a phenethyl group, and the like. Among these, for industrial reasons, a methyl group, an ethyl group, a phenyl group or a benzyl group is preferred, a methyl group or a phenyl group is more preferred, and a methyl group is even more preferred.

In formula (4), the proportion of R ₅ that is a methyl group out of all R ₅ is 50 mol% or more, preferably 65 mol% or more, and more preferably 70 mol% or more for industrial reasons. is. Although the upper limit is not particularly limited, it is preferably 100 mol %, that is, all methyl groups.

In formula (4), _n3 is 0 from the viewpoint of solvent solubility and compatibility with the maleimide compound (A) having no siloxane bond and the unmodified cyanate ester compound (B). Represents an integer from ~2. _n3 is preferably 0 to 1, more preferably 0. The compound represented by formula (4) may be a mixture of two or more compounds with different _n3 .

In this embodiment, the silicone (C2) having a maleimide structure at both ends can be used as a powder, and can be used alone or in combination of two or more.

The method for producing the silicone (C2) having a maleimide structure at both ends is not particularly limited. For example, an acid anhydride compound and a siloxane compound are mixed in an organic solvent capable of dissolving these raw materials. A method of mixing and reacting is mentioned. A catalyst may be used in the reaction process, if necessary. Moreover, it is preferable to carry out the reaction at a low temperature.

Acid anhydride compounds include, but are not limited to, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, and hexahydrophthalic anhydride. acid, methylhexahydrophthalic anhydride, and the like. From an industrial point of view, maleic anhydride is preferred. These acid anhydride compounds may be used alone or in combination of two or more.

The siloxane compound is not particularly limited, but 1,3-bis(3-aminopropyl)tetramethyldisiloxane, bis(3-aminobutyl)tetramethyldisiloxane, bis(3-aminopropyl)tetraphenyldisiloxane, Bis(3-aminobutyl)tetraphenyldisiloxane, bis(4-aminophenyl)tetramethyldisiloxane, bis(4-amino-3-methylphenyl)tetramethyldisiloxane, bis(4-aminophenyl)tetraphenyldisiloxane siloxane and the like. From an industrial point of view, 1,3-bis(3-aminopropyl)tetramethyldisiloxane is preferred. These siloxane compounds may be used alone or in combination of two or more.

Organic solvents include, but are not limited to, aprotic solvents such as dimethylsulfone, dimethylsulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidinone, and N-methylpyrrolidone. Polar solvents, sulfones such as tetramethylene sulfone, ether solvents such as diethylene glycol dimethyl ether, diethylene glycol diethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monomethyl ether monoacetate, propylene glycol monobutyl ether, methyl ethyl ketone, methyl isobutyl ketone, Examples include ketone solvents such as cyclopentanone and cyclohexanone, and aromatic solvents such as toluene and xylene. Among them, aprotic polar solvents are preferred from the viewpoint of reactivity. These organic solvents may be used alone or in combination of two or more.

The catalyst is not particularly limited, but may be organometallic salts such as tin octylate, zinc octylate, dibutyltin dimaleate, zinc naphthenate, cobalt naphthenate, tin oleate, and metals such as zinc chloride, aluminum chloride, and tin chloride. Chlorides are mentioned. Among them, cobalt naphthenate is preferable from the viewpoint of reactivity.
These catalysts may be used alone or in combination of two or more.

The content of the silicone (C2) having a maleimide structure at both ends in the resin composition according to the present embodiment is such that the sum of the masses of (C1) and (C2) is 5 to 25 parts per 100 parts by mass of the resin solid content. Although it is not particularly limited as long as it is a part by mass, 10 to 20 parts by mass is particularly preferable for (C2) from the viewpoint of dielectric constant, dielectric loss tangent, and flame resistance. In addition, (C1) and (C2) can be appropriately mixed and used.

[Filler (D)]
The resin composition according to the present embodiment preferably contains a filler (D) in order to improve low dielectric constant properties, low dielectric loss tangent properties, flame resistance, and low thermal expansion properties. As the filler (D) used in the present embodiment, known fillers can be used as appropriate, and the type thereof is not particularly limited, and fillers generally used in the industry can be suitably used. . Specifically, silicas such as natural silica, fused silica, synthetic silica, amorphous silica, aerosil, hollow silica, white carbon, titanium white, zinc oxide, magnesium oxide, zirconium oxide, boron nitride, aggregated boron nitride, silicon nitride , Aluminum Nitride, Barium Sulfate, Aluminum Hydroxide, Heat Treated Aluminum Hydroxide (Aluminum Hydroxide Heat Treated to Reduce Part of the Water of Crystallization), Boehmite, Metal Hydrates such as Magnesium Hydroxide, Oxides Molybdenum and molybdenum compounds such as zinc molybdate, zinc borate, zinc stannate, alumina, clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, A-glass, NE-glass, C -Glass, L-glass, D-glass, S-glass, M-glass G20, short glass fibers (including glass fine powders such as E-glass, T-glass, D-glass, S-glass, Q-glass, etc.), hollow In addition to inorganic fillers such as glass and spherical glass, organic fillers such as styrene, butadiene, and acrylic rubber powders, core-shell rubber powders, silicone resin powders, silicone rubber powders, and silicone compound powders. is mentioned. These fillers may be used alone or in combination of two or more. Among these, one or more selected from the group consisting of silica, aluminum hydroxide, boehmite, magnesium oxide and magnesium hydroxide is suitable. By using these fillers, properties such as thermal expansion properties, dimensional stability and flame resistance of the resin composition are improved.

The content of the filler (D) in the resin composition according to the present embodiment can be appropriately set according to the desired properties and is not particularly limited, but the resin solid content in the resin composition is 100 parts by mass. 50 to 1,600 parts by mass is preferable, 50 to 500 parts by mass is more preferable, and 50 to 300 parts by mass is more preferable. Alternatively, the filler (D) may be 75 to 250 parts by mass, or may be 100 to 200 parts by mass. By setting the content of the filler within this range, the moldability of the resin composition is improved.

The resin composition may contain only one filler (D), or may contain two or more fillers (D). When two or more types are included, the total amount is preferably within the above range.

When using the filler (D) here, it is preferable to use together at least one selected from the group consisting of silane coupling agents and wetting and dispersing agents. As the silane coupling agent, those generally used for surface treatment of inorganic substances can be suitably used, and the type thereof is not particularly limited. Specifically, aminosilanes such as γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, β-(3,4 -epoxysilanes such as epoxycyclohexyl)ethyltrimethoxysilane, vinylsilanes such as γ-methacryloxypropyltrimethoxysilane, vinyl-tri(β-methoxyethoxy)silane, N-β-(N-vinylbenzylaminoethyl)- Examples include cationic silanes such as γ-aminopropyltrimethoxysilane hydrochloride, phenylsilanes, and the like. The silane coupling agents may be used alone or in combination of two or more. As the wetting and dispersing agent, those generally used for paints can be suitably used, and the type thereof is not particularly limited. Preferably, a copolymer-based wetting and dispersing agent is used, specific examples of which include Disperbyk-110, 111, 161, 180, 2009, 2152, BYK-W996 and BYK-W9010 manufactured by BYK-Chemie Japan Co., Ltd. , BYK-W903, BYK-W940, and the like. Wetting and dispersing agents may be used alone or in combination of two or more.

The content of the silane coupling agent is not particularly limited, and may be about 1 to 5 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition. The content of the dispersant (especially the wetting and dispersing agent) is not particularly limited, and may be, for example, about 0.5 to 5 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition.

[Other ingredients]
Furthermore, in the resin composition according to the present embodiment, a maleimide compound other than the maleimide compound (A) having no siloxane bond, the unmodified cyanate ester compound ( A cyanate ester compound other than B), an elastomer other than the elastomer (C1) having a styrene content of 17% by mass or more and having a styrene structure at both ends, and a silicone having a maleimide structure at both ends (C2) containing silicones, epoxy resins, phenolic resins, oxetane resins, benzoxazine compounds, polyphenylene ether compounds, styrene oligomers (excluding those falling under (C1)), flame retardants, curing accelerators, organic solvents, etc. good too. By using these together, desired properties such as flame resistance, high metal foil (copper foil) peel strength, and low dielectric properties of a cured product obtained by curing the resin composition can be improved.
The resin composition according to the present embodiment includes a maleimide compound other than the maleimide compound (A) having no siloxane bond, a cyanate ester compound other than the unmodified cyanate ester compound (B), and the styrene content of The total amount of the elastomer other than the elastomer (C1) having a styrene structure at both ends and the silicone other than the silicone (C2) having a maleimide structure at both ends is 17% by mass or more of the solid content of the resin. % by mass or less is preferable, and 1% by mass or less is more preferable. With such a configuration, the effects of the present invention are exhibited more effectively.

[Epoxy resin]
The epoxy resin is not particularly limited as long as it is a compound or resin having two or more epoxy groups in one molecule. type epoxy resin, phenol novolak type epoxy resin, bisphenol A novolak type epoxy resin, glycidyl ester type epoxy resin, aralkyl novolak type epoxy resin, biphenyl aralkyl type epoxy resin, naphthylene ether type epoxy resin, cresol novolac type epoxy resin, polyfunctional Phenol-type epoxy resin, naphthalene-type epoxy resin, anthracene-type epoxy resin, naphthalene skeleton-modified novolac-type epoxy resin, phenol-aralkyl-type epoxy resin, naphthol-aralkyl-type epoxy resin, dicyclopentadiene-type epoxy resin, biphenyl-type epoxy resin, alicyclic Epoxy resins, polyol-type epoxy resins, phosphorus-containing epoxy resins, compounds obtained by epoxidizing double bonds such as glycidylamine, glycidyl esters, and butadiene, and compounds obtained by reacting hydroxyl-containing silicone resins with epichlorohydrin. mentioned. These epoxy resins may be used alone or in combination of two or more. Among these, biphenyl aralkyl type epoxy resins, naphthylene ether type epoxy resins, polyfunctional phenol type epoxy resins, and naphthalene type epoxy resins are preferable from the viewpoint of further improving flame resistance and heat resistance.

[Phenolic resin]
The phenolic resin is not particularly limited as long as it is a compound or resin having two or more phenolic hydroxy groups in one molecule. Bisphenol S type phenolic resin, phenolic novolak resin, bisphenol A novolak type phenolic resin, glycidyl ester type phenolic resin, aralkyl novolak phenolic resin, biphenylaralkyl type phenolic resin, cresol novolac type phenolic resin, polyfunctional phenolic resin, naphthol resin, naphthol novolac Resins, polyfunctional naphthol resins, anthracene-type phenol resins, naphthalene skeleton-modified novolac-type phenol resins, phenol aralkyl-type phenol resins, naphthol aralkyl-type phenol resins, dicyclopentadiene-type phenol resins, biphenyl-type phenol resins, alicyclic phenol resins, Examples include polyol type phenol resins, phosphorus-containing phenol resins, and hydroxyl group-containing silicone resins. These phenol resins may be used alone or in combination of two or more. Among these, from the viewpoint of further improving flame resistance, it is at least one selected from the group consisting of biphenylaralkyl-type phenolic resins, naphtholaralkyl-type phenolic resins, phosphorus-containing phenolic resins, and hydroxyl-containing silicone resins. preferable.

[Oxetane resin]
The oxetane resin is not particularly limited, and examples thereof include oxetane, alkyloxetane (eg, 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, 3,3-dimethyloxatane, etc.), 3-methyl- 3-methoxymethyloxetane, 3,3-di(trifluoromethyl)perfluoxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, biphenyl type oxetane, OXT-101 (Toagosei Co., Ltd.) product), OXT-121 (a product of Toagosei Co., Ltd.), and the like. These oxetane resins may be used alone or in combination of two or more.

[Benzoxazine compound]
The benzoxazine compound is not particularly limited as long as it is a compound having two or more dihydrobenzoxazine rings in one molecule. type benzoxazine BF-BXZ (product of Konishi Chemical Co., Ltd.), bisphenol S-type benzoxazine BS-BXZ (product of Konishi Chemical Co., Ltd.), and the like. These benzoxazine compounds may be used alone or in combination of two or more.

（式（８）中、Ｒ_１６、Ｒ_１７、Ｒ_１８、及びＲ_１９は、各々独立に炭素数６以下のアルキル基、アリール基、ハロゲン原子、又は水素原子を表す。）
で表される構成単位の重合体を含む化合物を用いることができる。
前記化合物は、式（９）：

（式（９）中、Ｒ_２０、Ｒ_２１、Ｒ_２２、Ｒ_２６、Ｒ_２７は、各々独立に炭素数６以下のアルキル基又はフェニル基を表す。Ｒ_２３、Ｒ_２４、Ｒ_２５は、各々独立に水素原子、炭素数６以下のアルキル基又はフェニル基を表す。）
で表される構造、及び、式（１０）：

（式（１０）中、Ｒ_２８，Ｒ_２９、Ｒ_３０、Ｒ_３１、Ｒ_３２、Ｒ_３３、Ｒ_３４、Ｒ_３５は、各々独立に水素原子、炭素数６以下のアルキル基又はフェニル基を表す。－Ａ－は、炭素数２０以下の直鎖状、分岐状又は環状の２価の炭化水素基である）
で表される構造からなる群より選ばれた少なくとも１種をさらに含んでもよい。[Polyphenylene ether compound]
As a polyphenylene ether compound, formula (8):

(In Formula (8), R ₁₆ , R ₁₇ , R ₁₈ and R ₁₉ each independently represent an alkyl group having 6 or less carbon atoms, an aryl group, a halogen atom or a hydrogen atom.)
A compound containing a polymer of structural units represented by can be used.
Said compound has the formula (9):

(In Formula (9), R ₂₀ , R ₂₁ , R ₂₂ , R ₂₆ and R ₂₇ each independently represent an alkyl group having 6 or less carbon atoms or a phenyl group. R ₂₃ , R ₂₄ and R ₂₅ each It independently represents a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.)
and a structure represented by formula (10):

(In Formula (10), R ₂₈ , R ₂₉ , R ₃₀ , R ₃₁ , R ₃₂ , R ₃₃ , R ₃₄ , and R ₃₅ each independently represent a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. .-A- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms)
It may further contain at least one selected from the group consisting of structures represented by

As polyphenylene ether compounds, some or all of the terminals are functionalized with ethylenically unsaturated groups such as vinylbenzyl groups, epoxy groups, amino groups, hydroxyl groups, mercapto groups, carboxy groups, methacryl groups, silyl groups, and the like. A modified polyphenylene ether can also be used. You may use these individually by 1 type or in combination of 2 or more types.
Examples of the modified polyphenylene ether having a terminal hydroxyl group include SA90 manufactured by SABIC Innovative Plastics. Examples of the modified polyphenylene ether having a methacryl group at the end include SA9000 manufactured by SABIC Innovative Plastics.

The method for producing the modified polyphenylene ether is not particularly limited as long as the effect of the present invention can be obtained. For example, it can be produced by the method described in Japanese Patent No. 4591665.

The modified polyphenylene ether preferably contains a modified polyphenylene ether having an ethylenically unsaturated group at its terminal. Examples of ethylenically unsaturated groups include alkenyl groups such as ethenyl, allyl, acryl, methacryl, propenyl, butenyl, hexenyl and octenyl groups; cycloalkenyl groups such as cyclopentenyl and cyclohexenyl groups; Alkenylaryl groups such as a benzyl group and a vinylnaphthyl group can be mentioned, and a vinylbenzyl group is preferred. The terminal ethylenically unsaturated groups may be single or multiple, and may be the same functional group or different functional groups.

（式（１１）中、Ｘはアリール基（芳香族基）を示し、－（Ｙ－Ｏ）ｎ_１０－はポリフェニレンエーテル部分を示す。Ｒ_３６、Ｒ_３７、Ｒ_３８は、各々独立に水素原子、アルキル基、アルケニル基又はアルキニル基を示し、ｎ_１０は１～１００の整数を示し、ｎ_１１は１～６の整数を示し、ｎ_１２は１～４の整数を示す。好ましくは、ｎ_１１は１以上４以下の整数であるとよく、さらに好ましくは、ｎ_１１は１又は２であるとよく、理想的にはｎ_１１は１であるとよい。また、好ましくは、ｎ_１２は１以上３以下の整数であるとよく、さらに好ましくは、ｎ_１２は１又は２であるとよく、理想的にはｎ_１２は２であるとよい。）
で表される化合物が挙げられる。ｎ_１０、ｎ_１１及びｎ_１２の少なくとも１つが異なる２種以上の化合物の混合物であってもよい。Formula (11) as a modified polyphenylene ether having an ethylenically unsaturated group at the end:

(In formula (11), X represents an aryl group (aromatic group), —(Y—O)n ₁₀ — represents a polyphenylene ether moiety. R ₃₆ , R ₃₇ , and R ₃₈ each independently represent a hydrogen atom , an alkyl group, an alkenyl group or an alkynyl group, _n10 represents an integer of 1 to 100, _n11 represents an integer of 1 to 6, _n12 represents an integer of 1 to 4. Preferably, _n11 is preferably an integer of 1 or more and 4 or less, more preferably _n11 is 1 or 2, and ideally _n11 is 1. Also, _n12 is preferably 1 or more. It is preferably an integer of 3 or less, more preferably _n12 is 1 or 2, and ideally _n12 is 2.)
The compound represented by is mentioned. At least one of n ₁₀ , n ₁₁ and n ₁₂ may be a mixture of two or more different compounds.

The aryl group represented by X in formula (11) is a group obtained by removing n ₁₂ hydrogen atoms from one ring structure selected from a benzene ring structure, a biphenyl structure, an indenyl ring structure, and a naphthalene ring structure ( phenyl group, biphenyl group, indenyl group, and naphthyl group), preferably biphenyl group.
Here, the aryl group represented by X is a 2,2-diphenylpropane group bonded through an alkylene group such as a diphenyl ether group in which the above aryl group is bonded via an oxygen atom, a benzophenone group bonded via a carbonyl group, or the like. etc. may be included.
In addition, the aryl group may be substituted with a general substituent such as an alkyl group (preferably an alkyl group having 1 to 6 carbon atoms, especially a methyl group), an alkenyl group, an alkynyl group or a halogen atom. However, since the "aryl group" is substituted on the polyphenylene ether moiety through an oxygen atom, the limit on the number of general substituents depends on the number of polyphenylene ether moieties.

As the polyphenylene ether portion in formula (11), a structural unit represented by formula (8), (9), or (10) can be used, and in particular a structural unit represented by formula (8) is included. is particularly preferred.

The modified polyphenylene ether represented by formula (11) preferably has a number average molecular weight of 1,000 or more and 7,000 or less. Further, in the formula (1), one having a minimum melt viscosity of 50000 Pa·s or less can be used. In particular, in formula (1), those having a number average molecular weight of 1,000 or more and 7,000 or less and a minimum melt viscosity of 50,000 Pa·s or less are preferable.
Number average molecular weights are measured using gel permeation chromatography according to standard methods. More preferably, the number average molecular weight is 1,000-3,000. By setting the number average molecular weight to 1,000 or more and 7,000 or less, the effect of achieving both moldability and electrical properties (low dielectric constant and low dielectric loss tangent) is exhibited more effectively.
The minimum melt viscosity is measured using a dynamic viscoelasticity measuring device according to a standard method. The minimum melt viscosity is more preferably 500 to 50000 Pa·s. By setting the minimum melt viscosity to 50000 Pa·s or less, the effect of achieving both moldability and electrical properties is more effectively exhibited.

（式（１２）中、Ｘは、アリール基（芳香族基）であり、－（Ｙ－Ｏ）_ｎ１３－は、それぞれ独立に、ポリフェニレンエーテル部分を示し、ｎ１３は、それぞれ独立に、１～１００の整数を示す。）
Ｘは、式（１１）におけるＸにおいて２価基である以外は同義である。連結基－（Ｙ－Ｏ）_ｎ１３－は、式（１１）における－（Ｙ－Ｏ）_ｎ１０－と同義である。また、式（１２）で表される化合物は、Ｘ又はｎ_１３が異なる２種以上の化合物の混合物であってもよい。The modified polyphenylene ether is preferably a compound represented by the following formula (12) among the compounds represented by the formula (11).

(In formula (12), X is an aryl group (aromatic group), -(Y-O) _n13 - each independently represents a polyphenylene ether moiety, n13 each independently represents 1 to 100 indicates an integer of
X has the same meaning as X in formula (11) except that it is a divalent group. The linking group -(YO) _n13 - has the same meaning as -(YO) _n10 - in formula (11). Also, the compound represented by formula (12) may be a mixture of two or more compounds in which X or _n13 is different.

X in formulas (11) and (12) is formula (13), formula (14), or formula (15), and -(YO)n ₁₀ - in formula (11) and formula (12) —(Y—O)n ₁₃ — in is more preferably a structure in which formula (16) or formula (17) is arranged, or a structure in which formulas (16) and (17) are arranged randomly.

（式（１４）中、Ｒ_３９、Ｒ_４０、Ｒ_４１及びＲ_４２は、各々独立に水素原子又はメチル基を表す。－Ｂ－は、炭素数２０以下の直鎖状、分岐状又は環状の２価の炭化水素基である。）

(In formula (14), R ₃₉ , R ₄₀ , R ₄₁ and R ₄₂ each independently represent a hydrogen atom or a methyl group. —B— is a linear, branched or cyclic It is a divalent hydrocarbon group.)

（式（１５）中、－Ｂ－は、炭素数２０以下の直鎖状、分岐状又は環状の２価の炭化水素基である）

(In formula (15), -B- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms)

The method for producing a modified polyphenylene ether having a structure represented by formula (12) is not particularly limited, for example, a bifunctional phenylene ether obtained by oxidative coupling of a bifunctional phenol compound and a monofunctional phenol compound. It can be produced by vinylbenzyl etherifying the terminal phenolic hydroxyl group of the oligomer.
Commercially available modified polyphenylene ethers can be used. For example, OPE-2St1200 and OPE-2st2200 manufactured by Mitsubishi Gas Chemical Company, Inc. can be preferably used.

[Styrene oligomer]
The styrene oligomer has a styrene content of 17% by mass or more and is distinguished from the elastomer (C1) having styrene structures at both ends. The styrene oligomer is obtained by polymerizing one or more of the group consisting of styrene, styrene derivatives, and vinyl toluene, and has a number average molecular weight of 178 to 1,600, an average number of aromatic rings of 2 to 14, and an average number of aromatic rings of 2 to 14. 2 to 14 in a total amount of 50% by mass or more and a boiling point of 300° C. or more and no branched structure. Styrene derivatives specifically refer to styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene and 4-cyclohexylstyrene.

Examples of styrene oligomers include styrene polymers, vinyltoluene polymers, α-methylstyrene polymers, vinyltoluene-α-methylstyrene polymers, styrene-α-styrene polymers and the like. As the styrene polymer, commercially available products may be used, such as PICOLASTIC A5 (manufactured by Eastman Chemical Co.), PICOLASTIC A-75 (manufactured by Eastman Chemical Co.), PICOTEX 75 (manufactured by Eastman Chemical Co.), and FTR. -8100 (manufactured by Mitsui Chemicals, Inc.) and FTR-8120 (manufactured by Mitsui Chemicals, Inc.). Examples of the vinyltoluene-α-methylstyrene polymer include Picotex LC (manufactured by Eastman Chemical Co.). Examples of α-methylstyrene polymers include Crystalex 3070 (manufactured by Eastman Chemical Co.), Crystalex 3085 (manufactured by Eastman Chemical Co.), Crystalex (3100), Crystalex 5140 (manufactured by Eastman Chemical Co.) and FMR. -0100 (manufactured by Mitsui Chemicals, Inc.) and FMR-0150 (manufactured by Mitsui Chemicals, Inc.). Further, the styrene-α-styrene polymer includes FTR-2120 (manufactured by Mitsui Chemicals, Inc.). These styrene oligomers may be used alone or in combination of two or more.

The content of the styrene oligomer is preferably 1 to 30 parts by mass with respect to 100 parts by mass of the resin solid content of the resin composition from the viewpoint of low dielectric constant, low dielectric loss tangent and chemical resistance. 15 parts by mass is particularly preferred.

[Flame retardants]
Known flame retardants can be used, for example, brominated epoxy resin, brominated polycarbonate, brominated polystyrene, brominated styrene, brominated phthalimide, tetrabromobisphenol A, pentabromobenzyl (meth)acrylate, pentabromo Halogenated flame retardants such as toluene, tribromophenol, hexabromobenzene, decabromodiphenyl ether, bis-1,2-pentabromophenylethane, chlorinated polystyrene, chlorinated paraffin, red phosphorus, tricresyl phosphate, triphenyl phosphate , cresyl diphenyl phosphate, trixylenyl phosphate, trialkyl phosphate, dialkyl phosphate, tris(chloroethyl) phosphate, phosphazene, 1,3-phenylenebis(2,6-dixylenyl phosphate), 10-(2,5- Dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, phosphorus-based flame retardants, aluminum hydroxide, magnesium hydroxide, partial boehmite, boehmite, zinc borate, antimony trioxide, etc. Silicone-based flame retardants such as flame retardants, silicone rubbers, and silicone resins can be used. These flame retardants may be used alone or in combination of two or more. Among these, 1,3-phenylene bis(2,6-dixylenyl phosphate) is preferable because it hardly impairs low dielectric properties. The phosphorus content in the resin composition is preferably 0.1 to 5% by mass.

[Curing accelerator]
The resin composition according to this embodiment may contain a curing accelerator for appropriately adjusting the curing speed. Examples of curing accelerators include those commonly used as curing accelerators such as maleimide compounds, cyanate ester compounds, epoxy resins, and organic metal salts (e.g., zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetonate, nickel octylate, manganese octylate, etc.), phenolic compounds (e.g., phenol, xylenol, cresol, resorcinol, catechol, octylphenol, nonylphenol, etc.), alcohols (e.g., 1-butanol, 2-ethyl hexanol, etc.), imidazoles (e.g., 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, etc.), derivatives such as adducts of carboxylic acids of these imidazoles or their acid anhydrides, amines (e.g., dicyandiamide, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, etc.), phosphorus compounds (e.g., phosphine compounds, phosphine oxide compounds, phosphonium salt compounds, diphosphine compounds, etc.), epoxies - imidazole adduct compounds, peroxides (e.g., benzoyl peroxide, p-chlorobenzoyl peroxide, di-t-butyl peroxide, diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, etc.), azo compounds ( for example, azobisisobutyronitrile, etc.). A hardening accelerator may be used independently or may use 2 or more types together.

The content of the curing accelerator may generally be about 0.005 to 10 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition.

The resin composition according to the present embodiment may contain thermosetting resins, thermoplastic resins, various polymer compounds such as oligomers thereof, and various additives other than the above components. Additives include UV absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, flow control agents, lubricants, antifoaming agents, dispersants, and leveling agents. agents, brighteners, polymerization inhibitors, and the like. These additives may be used alone or in combination of two or more.

[Organic solvent]
The resin composition according to this embodiment may contain an organic solvent. In this case, the resin composition according to the present embodiment is in a form (solution or varnish) in which at least part, preferably all of the various resin components described above are dissolved or compatible with an organic solvent. The organic solvent is not particularly limited as long as it is a polar organic solvent or a non-polar organic solvent capable of dissolving or dissolving at least part, preferably all, of the various resin components described above. Examples of polar organic solvents include ketones. (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, etc.), cellosolves (e.g., propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, etc.), esters (e.g., ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, acetic acid isoamyl, ethyl lactate, methyl methoxypropionate, methyl hydroxyisobutyrate, etc.) amides (e.g., dimethoxyacetamide, dimethylformamides, etc.); nonpolar organic solvents include aromatic hydrocarbons (e.g., toluene, xylene etc.). These organic solvents may be used alone or in combination of two or more.

[Resin composition]
The resin composition according to the present embodiment can be prepared according to a conventional method, and contains a maleimide compound (A) having no siloxane bond, an unmodified cyanate ester compound (B), and a styrene content of 17% by mass. and at least one selected from the group consisting of an elastomer (C1) having a styrene structure at both ends and a silicone (C2) having a maleimide structure at both ends, and, if necessary, other The preparation method is not particularly limited as long as it is a method for obtaining a resin composition uniformly containing optional components. For example, a maleimide compound (A) having no siloxane bond, an unmodified cyanate ester compound (B), and an elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends, and At least one selected from the group consisting of silicones (C2) having a maleimide structure at both ends is sequentially blended with a solvent and sufficiently stirred to easily prepare the resin composition according to the present embodiment. .

In the resin composition according to the present embodiment, the sum of the masses of the maleimide compound (A) having no siloxane bond, the unmodified cyanate ester compound (B), the elastomer (C1), and the silicone (C2) is a resin It preferably accounts for 90% by mass or more, more preferably 95% by mass or more, and may account for 98% by mass or more of the resin solid content contained in the composition.

[Use]
The resin composition according to this embodiment can be suitably used as an insulating layer of a printed wiring board and a semiconductor package material. The resin composition according to the present embodiment can be suitably used as a material constituting prepregs, metal foil-clad laminates using prepregs, resin sheets, and printed wiring boards.

[Prepreg]
The prepreg according to this embodiment is formed from a base material and the resin composition according to this embodiment. The prepreg according to the present embodiment can be obtained, for example, by impregnating or applying the resin composition according to the present embodiment to a base material and then semi-curing the resin composition by drying at 120 to 220° C. for about 2 to 15 minutes. be done. In this case, the amount of the resin composition attached to the substrate, that is, the amount of the resin composition (including the filler (D)) relative to the total amount of the prepreg after semi-curing is preferably in the range of 20 to 99% by mass.

The base material is not particularly limited as long as it is a base material used for various printed wiring board materials. Examples of materials for the base material include glass fibers (e.g., E-glass, D-glass, L-glass, S-glass, T-glass, Q-glass, UN-glass, NE-glass, spherical glass, etc.). Examples include inorganic fibers other than glass (for example, quartz) and organic fibers (for example, polyimide, polyamide, polyester, liquid crystal polyester, polytetrafluoroethylene, etc.). The form of the substrate is not particularly limited, and includes woven fabric, nonwoven fabric, roving, chopped strand mat, surfacing mat, and the like. These substrates may be used alone or in combination of two or more. Among these base materials, from the viewpoint of dimensional stability, a woven fabric subjected to super-spreading treatment and stuffing treatment is preferable. A glass woven fabric with a molecular weight of ² or less is preferable, and from the viewpoint of moisture absorption and heat resistance, a glass woven fabric surface-treated with a silane coupling agent such as epoxysilane treatment or aminosilane treatment is preferable. From the viewpoint of electrical properties, a low dielectric glass cloth made of glass fibers exhibiting a low dielectric constant and a low dielectric loss tangent, such as L-glass, NE-glass, and Q-glass, is more preferable.

[Metal foil clad laminate]
The metal foil-clad laminate according to the present embodiment has at least one prepreg according to the present embodiment stacked and metal foils arranged on one side or both sides of the prepreg. The metal foil-clad laminate according to the present embodiment can be produced, for example, by stacking at least one or more prepregs according to the present embodiment, placing a metal foil on one or both sides thereof, and laminating. It can be produced by arranging a metal foil such as copper or aluminum on one side or both sides thereof and performing lamination molding. The metal foil is not particularly limited as long as it is used as a material for printed wiring boards, and examples thereof include copper foil such as rolled copper foil and electrolytic copper foil. The thickness of the metal foil (copper foil) is not particularly limited, and may be about 1.5 to 70 μm. Examples of the molding method include methods commonly used for molding laminates and multilayer boards for printed wiring boards, and more specifically, using a multistage press machine, a multistage vacuum press machine, a continuous molding machine, an autoclave molding machine, and the like. Then, there is a method of laminate molding at a temperature of about 180 to 350° C., a heating time of about 100 to 300 minutes, and a surface pressure of about 20 to 100 kg/cm ² . A multilayer board can also be obtained by laminating and molding a combination of the prepreg according to the present embodiment and a wiring board for an inner layer separately produced. As a method for manufacturing a multilayer board, for example, a metal foil (copper foil) of about 35 μm is placed on both sides of one prepreg according to the present embodiment, laminated by the above molding method, and then an inner layer circuit is formed. , blackening treatment is performed on this circuit to form an inner layer circuit board, after which the inner layer circuit board and the prepreg according to the present embodiment are alternately arranged one by one, and a metal foil (copper A multi-layer board can be produced by placing a foil) and laminating under the above conditions, preferably under vacuum. The metal foil-clad laminate according to this embodiment can be suitably used as a printed wiring board.

[Printed wiring board]
A printed wiring board according to this embodiment includes an insulating layer and a conductor layer disposed on the surface of the insulating layer, and the insulating layer includes a layer formed from the resin composition according to this embodiment. Such a printed wiring board can be manufactured according to a conventional method, and the manufacturing method is not particularly limited. An example of a method for manufacturing a printed wiring board is shown below. First, a metal foil-clad laminate such as the copper-clad laminate described above is prepared. Next, the surface of the metal foil-clad laminate is etched to form an inner layer circuit, thereby producing an inner layer substrate. The surface of the inner layer circuit of this inner layer substrate is subjected to a surface treatment to increase the adhesive strength as necessary, and then the required number of prepregs described above are laminated on the surface of the inner layer circuit, and a metal foil for the outer layer circuit is laminated on the outer side. Then, heat and pressurize to integrally mold. In this manner, a multilayer laminate is produced in which an insulating layer composed of the base material and the cured product of the thermosetting resin composition is formed between the inner layer circuit and the metal foil for the outer layer circuit. Next, after drilling holes for through holes and via holes in this multilayer laminate, a plated metal film is formed on the walls of the holes for conducting the inner layer circuit and the metal foil for the outer layer circuit, and further the outer layer circuit. A printed wiring board is manufactured by etching the metal foil for the purpose to form an outer layer circuit.

The printed wiring board obtained in the above production example has an insulating layer and a conductor layer formed on the surface of the insulating layer, and the insulating layer is the above-described resin composition according to the present embodiment and its cured product. The configuration includes at least one of them. That is, the prepreg according to the present embodiment described above (including at least one of the base material and the resin composition according to the present embodiment impregnated or applied thereto and the cured product thereof), and the metal foil according to the present embodiment described above. The layer of the resin composition of the tension laminate (the layer containing at least one of the resin composition according to the present embodiment and a cured product thereof) contains at least one of the resin composition according to the present embodiment and a cured product thereof. It is composed of an insulating layer.

[Resin sheet]
The resin sheet according to this embodiment includes a support and a layer formed from the resin composition according to this embodiment and arranged on the surface of the support. The resin sheet can be used as a build-up film or dry film solder resist. The method for producing the resin sheet is not particularly limited, but for example, a resin sheet is obtained by applying (coating) a solution obtained by dissolving the resin composition according to the present embodiment in a solvent on a support and drying it. method.

The support used here includes, for example, polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, ethylenetetrafluoroethylene copolymer film, release film obtained by applying a release agent to the surface of these films, and polyimide. Examples include organic film substrates such as films, conductor foils such as copper foil and aluminum foil, and plate-like substrates such as glass plates, SUS plates, and FRP, but are not particularly limited.

As the coating method (coating method), for example, a solution obtained by dissolving the resin composition according to the present embodiment in a solvent is applied onto a support using a bar coater, a die coater, a doctor blade, a baker applicator, or the like. mentioned. Further, after drying, a single-layer sheet (resin sheet) can be obtained by peeling or etching the support from the resin sheet in which the support and the resin composition are laminated. A solution obtained by dissolving the resin composition according to the present embodiment in a solvent is supplied into a mold having a sheet-like cavity and dried to form a sheet, thereby using a support. A single layer sheet (resin sheet) can also be obtained without

In the production of the single-layer sheet or resin sheet according to the present embodiment, the drying conditions for removing the solvent are not particularly limited. A temperature of 20° C. to 200° C. and a time of 1 to 90 minutes are preferable because the curing of the resin composition proceeds. In addition, in the single-layer sheet or resin sheet, the resin composition can be used in an uncured state by simply drying the solvent, or can be used in a semi-cured (B-staged) state as necessary. can also Furthermore, the thickness of the resin layer of the single layer or resin sheet according to the present embodiment can be adjusted by the concentration of the solution of the resin composition according to the present embodiment and the coating thickness, and is not particularly limited, but generally A thickness of 0.1 to 500 μm is preferable because the solvent tends to remain during drying when the thickness of the coating increases.

(Synthesis Example 1) Synthesis of naphthol aralkyl-type cyanate ester compound (SNCN) 1-naphthol aralkyl resin (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) 300 g (OH group conversion 1.28 mol) and triethylamine 194.6 g (1.92 mol) ( 1.5 mol per 1 mol of hydroxy group) was dissolved in 1800 g of dichloromethane to prepare solution 1.
125.9 g (2.05 mol) of cyanogen chloride (1.6 mol per 1 mol of hydroxy group), 293.8 g of dichloromethane, 194.5 g (1.92 mol) of 36% hydrochloric acid (1.5 mol per 1 mol of hydroxy group) ) and 1205.9 g of water were poured into the solution 1 over 30 minutes while the liquid temperature was maintained at -2 to -0.5°C under stirring. After pouring solution 1, the mixture was stirred at the same temperature for 30 minutes. I ordered over. After pouring solution 2, the mixture was stirred at the same temperature for 30 minutes to complete the reaction.
After that, the reaction solution was allowed to stand to separate the organic phase and the aqueous phase. The resulting organic phase was washed 5 times with 1300 g of water. The electrical conductivity of the wastewater after the fifth washing was 5 μS/cm, and it was confirmed that the ionic compounds that could be removed were sufficiently removed by washing with water.
The organic phase after washing with water was concentrated under reduced pressure and finally concentrated to dryness at 90° C. for 1 hour to obtain 331 g of the objective naphthol aralkyl cyanate compound (SNCN) (orange viscous substance). The weight average molecular weight Mw of the obtained SNCN was 600. Also, the IR spectrum of SNCN showed absorption at 2250 cm ^-1 (cyanate ester group) and did not show absorption of the hydroxy group.

(Synthesis Example 2) Synthesis of Silicone (C2) Having Maleimide Structures at Both Terminals Represented by Formula (18) Into a reaction vessel equipped with a stirrer, a thermometer and a condenser, 50.5 parts of maleic anhydride and N- Add 125 parts of methylpyrrolidone, keep at 10 ° C. or less, Dow Corning Toray Co., Ltd. 1,3-bis (3-aminopropyl) tetramethyldisiloxane (trade name: BY16-871) 15 parts, 100 parts A solution dissolved in N-methylpyrrolidone was added dropwise. After the dropwise addition was completed, the reaction mixture was stirred at room temperature for 6 hours. Then, 11 parts of cobalt naphthenate and 102 parts of acetic anhydride were added to the reaction mixture and reacted at 80° C. for 4 hours.

While keeping the reaction mixture at 5°C or less, 500 parts of water was added, and the deposited precipitate was separated by filtration. The resulting solid was further washed with water and then dried to obtain a compound of formula (18), _1,1 ′-((1,1 _, 13 parts of 3,3-tetramethyldisiloxane-1,3-diyl)bis(propane-3,1-diyl))bis(1H-pyrrole-2,5-dione) were obtained. Yield was 53%.

(Example 1)
As the _maleimide compound (A) having no siloxane bond, a maleimide compound (BMI-2300 _, Daiwa Kasei Kogyo Co., Ltd. )) 27 parts by mass, and as the unmodified cyanate ester compound (B), 2,2-bis(4-cyanatophenyl)propane (CYTESTER (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd.) 63 parts by mass As the elastomer (C1) having a styrene content of 17% by mass or more and having a styrene structure at both ends, a styrene-butadiene-styrene block copolymer (TR2003, manufactured by JSR Corporation, styrene content: 40% by mass ) and 150 parts by mass of spherical silica (SC2050-MB, manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) as filler (D), and diluted with methyl ethyl ketone to a solid content of 65% by mass. Got varnish.

The obtained varnish is impregnated and coated on a low-dielectric glass cloth having a thickness of 0.069 mm, and dried by heating at 165° C. for 5 minutes using a dryer (pressure-resistant explosion-proof steam dryer, manufactured by Takasugi Seisakusho Co., Ltd.). Then, a prepreg having a resin composition content of 60% by mass was obtained. 12 μm copper foil (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both sides of one sheet and four sheets of this prepreg, and vacuum was applied at a pressure of 30 kg/cm ² and a temperature of 210° C. for 150 minutes. Pressing was performed to obtain 12 μm copper-clad laminates (metal foil-clad laminates) having a thickness of 0.1 mm and 0.4 mm. Using the obtained copper-clad laminate, dielectric constant, dielectric loss tangent, glass transition temperature, copper foil peel strength, and flame resistance were evaluated. Table 1 shows the results.

(Example 2)
In Example 1, a styrene-butadiene-styrene block copolymer (TR2003, manufactured by JSR Corporation, styrene Styrene-isoprene-styrene block copolymer (SIS5250, manufactured by JSR Corporation, styrene ratio 20% by mass) was used instead of using 10 parts by mass of styrene ratio 40% by mass). Copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained in the same manner. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Example 3)
In Example 1, without using the styrene-butadiene-styrene block copolymer (TR2003, manufactured by JSR Corporation, styrene content: 40% by mass), silicone (C2) having a maleimide structure at both ends was obtained from Synthesis Example 2. The resulting 1,1′-((1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis(propane-3,1-diyl))bis(1H-pyrrole-2,5- Copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained in the same manner as in Example 1, except that 10 parts by mass of dione was used. Table 2 shows the evaluation results of the obtained copper-clad laminate.

(Example 4)
As the maleimide compound (A) having no siloxane bond, in formula (1), a maleimide compound (BMI-2300, manufactured by Daiwa Kasei Kogyo Co., Ltd.) in which all R ₁ are hydrogen atoms and n ₁ is 1 to 3. 28.5 parts by mass, 66.5 parts by mass of SNCN obtained in Synthesis Example 1 as the unmodified cyanate ester compound (B), a styrene content of 17% by mass or more, and a styrene structure at both ends 5 parts by mass of styrene-butadiene-styrene block copolymer (TR2630, manufactured by JSR Corporation, styrene content: 32% by mass) as elastomer (C1), and spherical silica (D) (SC2050 -MB, manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) was mixed, and the solid content was diluted to 65% by mass with methyl ethyl ketone to obtain a varnish. Thereafter, in the same manner as in Example 1, copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Example 5)
In Example 4, 27 parts by mass of BMI-2300 used in Example 4 was used as the maleimide compound (A) having no siloxane bond, and the unmodified cyanate ester compound (B) was used in Example 4. 63 parts by mass of SNCN, a styrene content of 17% by mass or more, and 10 parts by mass of TR2630 used in Example 4 as the elastomer (C1) having a styrene structure at both ends. Copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained in the same manner. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Example 6)
In Example 4, 24 parts by mass of BMI-2300 used in Example 4 was used as the maleimide compound (A) having no siloxane bond, and the unmodified cyanate ester compound (B) was used in Example 4. 56 parts by mass of SNCN, a styrene content of 17% by mass or more, and 20 parts by mass of TR2630 used in Example 4 as the elastomer (C1) having a styrene structure at both ends; Copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained in the same manner. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Comparative example 1)
As the maleimide compound (A) having no siloxane bond, in formula (1), a maleimide compound (BMI-2300, manufactured by Daiwa Kasei Kogyo Co., Ltd.) in which all R ₁ are hydrogen atoms and n ₁ is 1 to 3. 30 parts by mass, 70 parts by mass of 2,2-bis(4-cyanatophenyl)propane (CYTESTER (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd.) as the unmodified cyanate ester compound (B), filler As (D), 150 parts by mass of spherical silica (SC2050-MB, manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) was mixed. A copper clad laminate was obtained. Tables 1 and 2 show the evaluation results of the obtained copper-clad laminates.

(Comparative example 2)
In Comparative Example 1, instead of using 2,2-bis(4-cyanatophenyl)propane (CYTESTER (registered trademark) manufactured by Mitsubishi Gas Chemical Co., Ltd.) as the unmodified cyanate ester compound (B), Copper-clad laminates with thicknesses of 0.1 mm and 0.4 mm were obtained in the same manner as in Comparative Example 1, except that 70 parts by mass of SNCN obtained in Synthesis Example 1 was used. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Comparative Example 3)
In Example 3, the silicone (C2) 1,1'-((1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis (Propane-3,1-diyl))bis(1H-pyrrole-2,5-dione) 10 parts by mass was not used, and instead acrylic polymer (weight average molecular weight: 2900, Toagosei Co., Ltd. ARUFON (registered trademark) ) US-6170) 10 parts by mass were used to obtain copper-clad laminates having a thickness of 0.1 mm and 0.4 mm in the same manner as in Example 3. Table 2 shows the evaluation results of the obtained copper-clad laminate.

(Comparative Example 4)
In Example 3, the silicone (C2) 1,1'-((1,1,3,3-tetramethyldisiloxane-1,3-diyl)bis (Propane-3,1-diyl))bis(1H-pyrrole-2,5-dione) 10 parts by mass was not used, and instead acrylic polymer (weight average molecular weight: 10000, Toagosei Co., Ltd. ARUFON (registered trademark) ) UC-3000) 10 parts by mass were used to obtain copper-clad laminates having a thickness of 0.1 mm and 0.4 mm in the same manner as in Example 3. Table 2 shows the evaluation results of the obtained copper-clad laminate.

(Comparative Example 5)
In Example 1, a styrene-butadiene-styrene block copolymer (TR2003, manufactured by JSR Corporation, styrene 40% by mass) was not used, and instead 10 parts by mass of styrene-butadiene rubber (L-SBR-820, manufactured by Kuraray Co., Ltd., weight average molecular weight 8000) having butadiene at both ends or one end was used. Copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained in the same manner as in Example 1. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Comparative Example 6)
In Example 4, 21 parts by mass of BMI-2300 used in Example 4 was used as the maleimide compound (A) having no siloxane bond, and the unmodified cyanate ester compound (B) was used in Example 4. 30 parts by mass of TR2630 used in Example 4 was used as the elastomer (C1) having 49 parts by mass of SNCN, a styrene content of 17% by mass or more, and a styrene structure at both ends; Copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained in the same manner. Table 1 shows the evaluation results of the obtained copper-clad laminate.

(Comparative Example 7)
In Example 5, a styrene-butadiene-styrene block copolymer (TR2630, manufactured by JSR Corp., styrene ratio 32 mass %) was not used, and instead 10 parts by mass of a styrene-isoprene-styrene block copolymer (SIS5229, manufactured by JSR Corporation, styrene content: 15% by mass) was used. A copper-clad laminate having a thickness of 0.1 mm and 0.4 mm was produced by using In Comparative Example 7, phase separation was observed between the components of the resin composition, and a uniform copper-clad laminate could not be obtained, so values for each physical property could not be obtained.

(Comparative Example 8)
As the maleimide compound (A) having no siloxane bond, in formula (1), a maleimide compound (BMI-2300, manufactured by Daiwa Kasei Kogyo Co., Ltd.) in which all R ₁ are hydrogen atoms and n ₁ is 1 to 3. 27 parts by mass of the unmodified cyanate ester compound (B), 63 parts by mass of SNCN obtained in Synthesis Example 1, and in formula (4), R ₅ is a methyl group, and the portion corresponding to n ₃ is 7. 10 parts by mass of silicone having a maleimide structure at both ends and 150 parts by mass of spherical silica (D) (SC2050-MB, Admatechs Co., Ltd., average particle size 0.5 μm) as filler (D). , and methyl ethyl ketone to a solid content of 65% by mass to obtain a varnish. Thereafter, in the same manner as in Example 1, copper-clad laminates having a thickness of 0.1 mm and 0.4 mm were obtained. In Comparative Example 8, phase separation was observed between the components of the resin composition, and a uniform copper-clad laminate could not be obtained, so values for each physical property could not be obtained.

(Measuring method and evaluation method)
(1) Dielectric constant (Dk) and dissipation factor (Df):
Using a sample obtained by removing the copper foil of the copper clad laminate having a thickness of 0.4 mm obtained in each example and each comparative example by etching, a perturbation method cavity resonator (Agilent Technology Co., Ltd. product, Agilent 8722ES) , 10 GHz dielectric constant and dissipation factor were measured.
(2) Glass transition temperature:
A dynamic viscoelasticity analyzer ( TA Instruments).
(3) Copper foil peel strength:
Using the 0.4 mm thick copper-clad laminate obtained in each example and each comparative example, the peel strength of the copper foil was measured according to JIS C6481:1996. A result of 0.5 kN/m or more is indicated by ◯, and a result of less than 0.5 kN/m is indicated by x.
(4) Flame resistance:
Using samples from which the copper foil of the 0.4 mm thick copper-clad laminates obtained in Example 3, Comparative Example 1, Comparative Example 3, and Comparative Example 4 was removed by etching, conforming to the UL94 vertical burning test method. and evaluated.

As described above, the resin composition of the present invention can be used in various applications such as electrical/electronic materials, machine tool materials, and aeronautical materials. It can be widely and effectively used as a resist, build-up laminate material, etc., and can be particularly effectively used as a printed wiring board material for high integration and high density in recent information terminal equipment and communication equipment. is. In addition, the laminate, metal foil clad laminate, etc. of the present invention can achieve particularly excellent low dielectric constant, low dielectric loss tangent, high glass transition temperature, and high copper foil peel strength at the same time. Practicality is extremely high.

As is clear from Table 1, by using the resin composition of the present invention, a prepreg and a printed wiring board that simultaneously achieve excellent low dielectric constant, low dielectric loss tangent, high glass transition temperature, and high copper foil peel strength. etc. can be realized.

Claims (8)

A maleimide compound (A) having no siloxane bond, an unmodified cyanate ester compound (B), and an elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends, and containing at least one selected from the group consisting of silicones (C2) having a maleimide structure at both ends,
The sum of the masses of (C1) and (C2) is 5 to 25 parts by mass with respect to 100 parts by mass of the resin solid content,
The silicone (C2) having a maleimide structure at both ends contains a maleimide-terminated silicone represented by the following formula (4),
The maleimide compound (A) having no siloxane bond consists of a maleimide compound represented by the following formula (1), a maleimide compound represented by the following formula (2), and a maleimide compound represented by the following formula (3). containing at least one selected from the group,
The non-modified cyanate ester compound (B) is a phenol novolak-type cyanate ester compound, a naphthol aralkyl-type cyanate ester compound, a naphthylene ether-type cyanate ester compound, a bisphenol A-type cyanate ester compound, and a bisphenol M-type cyanate ester compound. A resin composition containing at least one selected from the group consisting of a cyanate ester compound and a diallyl bisphenol A-type cyanate ester compound.

(In formula (4) above, each R ₅ independently represents an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms, and the proportion of R ₅ that is a methyl group among all R ₅ is 50 mol% or more, and n ₃ is an integer of 0 to 2.)

(In formula (1) above, each R ₁ independently represents a hydrogen atom or a methyl group, and n ₁ represents an integer of 1 or more.)

(In formula (2) above, each R ₂ independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, and n ₂ represents an integer of 1 or more and 10 or less.)

(In formula (3) above, each R3 _{independently} represents a hydrogen atom, a methyl group or an ethyl group, and each _R4 independently represents a hydrogen atom or a methyl group.) The elastomer (C1) having a styrene content of 17% by mass or more and having styrene structures at both ends is a styrene-butadiene block copolymer, a styrene-isoprene block copolymer, or a styrene-hydrogenated butadiene block copolymer. 2. The resin composition according to claim 1 , which contains at least one selected from the group consisting of polymers, styrene-hydrogenated isoprene block copolymers and styrene-hydrogenated (isoprene/butadiene) block copolymers. thing. 3. The resin composition according to claim 1, further comprising a filler (D). 4. The resin composition according to claim 3 , wherein the content of the filler (D) is 50 to 300 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition. A prepreg formed from a substrate and the resin composition according to any one of claims 1 to 4 . A metal foil-clad laminate comprising at least one prepreg according to claim 5 stacked and a metal foil disposed on one side or both sides of the prepreg. A resin sheet comprising a support and a layer formed from the resin composition according to any one of claims 1 to 4 disposed on the surface of the support. A printed wiring board comprising an insulating layer and a conductor layer disposed on the surface of the insulating layer, wherein the insulating layer is a layer formed from the resin composition according to any one of claims 1 to 4 . printed wiring boards, including;