Resin composition, cured product, resin composite sheet, prepreg, metal foil-clad laminate, printed wiring board, and semiconductor device

Abstract

Provided are a resin composition, a cured product, a resin composite sheet, a prepreg, a metal foil-clad laminate, a printed wiring board, and a semiconductor device. Provided is a resin composition according to the present disclosure which contains a heat-curable resin and a filler, wherein the curable resin contains a maleimide compound, and the filler contains a resin-containing shell and hollow resin particles having a hollow structure and surrounded by the shell.

Description

Resin compositions, cured products, resin composite sheets, prepregs, metal foil-clad laminates, printed circuit boards, and semiconductor devices.

[0001] The present invention relates to resin compositions, cured products, resin composite sheets, prepregs, metal foil-clad laminates, printed circuit boards, and semiconductor devices.

[0002] In the rapidly advancing field of substrate materials for high-speed communications, further reducing dielectric properties is crucial to minimize transmission loss and suppress electrical signal degradation. Furthermore, from the perspective of impedance control, there is a growing demand for low dielectric constant materials in thin-layer materials. In particular, improving the low dielectric properties of thin-layer materials requires reducing the dielectric properties of the materials constituting them. Fillers, in particular, significantly contribute to the properties of thin-layer materials, and the low dielectric properties of the fillers themselves greatly influence the properties of the thin-layer material.

[0003] Currently, silica is commonly used as a filler, but in order to further improve the low dielectric properties of laminated materials, it is necessary to further improve the low dielectric properties of the filler used. One method for improving the low dielectric properties of a filler is hollow silica, in which the inside of the filler has a hollow structure. For example, Patent Document 1 discloses a resin composition containing a hollow filler. Such a resin composition satisfies the requirements for low dielectric properties and is a material suitable for thin-sheet materials.

[0004] International Publication No. 2019 / 230661

[0005] However, while hollow silica becomes a filler with excellent low dielectric properties as its hollowness ratio increases, it also has the disadvantage of being more prone to cracking as the hollowness ratio increases. In particular, when hollow silica cracks in a thin sheet material, the internal hydroxyl groups are exposed, which can worsen the dielectric properties. On the other hand, materials suitable for thin sheets also require low thermal expansion. The present invention aims to solve these problems and to provide a resin composition that, when cured, is low dielectric and has low thermal expansion, as well as a cured product, a resin composite sheet, a prepreg, a metal foil-clad laminate, a printed circuit board, and a semiconductor device.

[0006] Based on the above-mentioned problems, as a result of studies conducted by the present inventor, it has been found that in a resin composition containing a thermosetting resin and a filler, the above problems can be solved by blending hollow resin particles as part or all of the filler. Specifically, the above problems have been solved by the following means. [1] A resin composition comprising a thermosetting resin and a filler, wherein the curable resin comprises a maleimide compound, and the filler comprises a resin-containing shell and hollow resin particles having a hollow structure surrounded by the shell. [2] The resin composition according to [1], wherein the porosity of the hollow resin particles is 50% or more, and the porosity is a value calculated from 100 - (apparent density D １ / true density D ０ ) × 100. [3] The resin composition according to [1] or [2], wherein the filler comprises silica. [4] The resin composition according to any one of [1] to [3], wherein, based on 100% by volume of the filler, the proportion of the hollow resin particles is 0.1% by volume or more and less than 60% by volume. [5] The resin composition according to any one of [1] to [4], wherein the thermosetting resin further comprises one or more selected from the group consisting of aromatic vinyl resins, cyanate ester compounds, epoxy compounds, and indane resins. [6] The resin composition according to any one of [1] to [5], wherein the maleimide compound comprises one selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M2), a compound represented by formula (M3), a compound represented by formula (M4), a compound represented by formula (M5), and a maleimide compound (M7), and the maleimide compound (M7) is a maleimide compound produced by using an aromatic amine compound (a1) having 1 to 3 alkyl groups on an aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride as reaction raw materials (1). (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ each independently represent a hydrogen atom or an organic group. R Ｍ５ and R Ｍ６ each independently represent a hydrogen atom or an alkyl group. Ar Ｍrepresents a divalent aromatic group. A is a 4-6 membered alicyclic group. R Ｍ７ and R Ｍ８ Each of these is independently an alkyl group. mx is 1 or 2, and lx is 0 or 1. Ｍ９ and R Ｍ１０ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ Each of these independently represents a hydrogen atom or an organic group. Ｍ１５ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group. px represents an integer from 0 to 3. nx represents an integer from 1 to 20. (In formula (M2), R ５４ Each of these independently represents a hydrogen atom or a methyl group, n ４ (This represents an integer greater than or equal to 1.) (In formula (M3), R ５５ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, n ５ (This represents an integer between 1 and 10, inclusive.) (In formula (M4), R ５６ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and R ５７ (Each of these independently represents either a hydrogen atom or a methyl group.) (In formula (M5), R ５８ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R ５９ Each of these independently represents a hydrogen atom or a methyl group, n ６(wherein represents an integer of 1 or more.) [7] The resin composition according to any one of [1] to [6], wherein the thermosetting resin has a group that reacts with the carbon-carbon double bond contained in the resin contained in the shell of the hollow resin particles. [8] The resin composition according to any one of [1] to [7], further comprising a flame retardant. [9] The porosity of the hollow resin particles is 50% or more, and the porosity is 100 - (apparent density D of the hollow resin particles) １ / True density D ０ The resin composition according to any one of [1] to [8], wherein the filler contains silica, the proportion of the hollow resin particles in 100% by volume of the filler is 0.1% by volume or more and less than 60% by volume, the thermosetting resin further contains one or more selected from the group consisting of aromatic vinyl resin, cyanate ester compound, epoxy compound, and indan resin, the maleimide compound contains one selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M2), a compound represented by formula (M3), a compound represented by formula (M4), a compound represented by formula (M5), and a maleimide compound (M7), the maleimide compound (M7) is a maleimide compound that uses an aromatic amine compound (a1) having one or more alkyl groups on an aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride as reaction raw materials (1), and further contains a flame retardant. (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ Each of these independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4-6 membered alicyclic group. R Ｍ７ and R Ｍ８ Each of these is independently an alkyl group. mx is 1 or 2, and lx is 0 or 1. Ｍ９ and R Ｍ１０ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , RＭ１３ , and R Ｍ１４ Each of these independently represents a hydrogen atom or an organic group. Ｍ１５ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group. px represents an integer from 0 to 3. nx represents an integer from 1 to 20. (In formula (M2), R ５４ Each of these independently represents a hydrogen atom or a methyl group, n ４ (This represents an integer greater than or equal to 1.) (In formula (M3), R ５５ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, n ５ (This represents an integer between 1 and 10, inclusive.) (In formula (M4), R ５６ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and R ５７ (Each of these independently represents either a hydrogen atom or a methyl group.) (In formula (M5), R ５８ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R ５９ Each of these independently represents a hydrogen atom or a methyl group, n ６(where represents an integer of 1 or more.)

[10] A cured product of the resin composition according to any one of [1] to [9].

[11] A resin composite sheet comprising a support and a layer formed from the resin composition according to any one of [1] to [9] disposed on the surface of the support.

[12] A prepreg formed from a substrate and the resin composition according to any one of [1] to [9].

[13] A metal foil-clad laminate comprising at least one prepreg according to

[12] and a metal foil disposed on one or both sides of the prepreg.

[14] A printed circuit board comprising an insulating layer and a conductor layer disposed on the surface of the insulating layer, wherein the insulating layer comprises a layer formed from the resin composition according to any one of [1] to [9].

[15] A semiconductor device comprising the printed circuit board according to

[14] .

[0007] The present invention makes it possible to provide a resin composition that, when cured, exhibits low dielectric properties and low thermal expansion, as well as cured products, resin composite sheets, prepregs, metal foil-clad laminates, printed circuit boards, and semiconductor devices.

[0008] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). Note that the following embodiments are illustrative examples for explaining the present invention, and the present invention is not limited to these embodiments. In this specification, "~" is used to mean that the numerical values ​​before and after it include the lower and upper limits. Furthermore, the upper and lower limits of numerical values ​​in this specification are given as examples of this embodiment, regardless of the combination of the upper and lower limits. In this specification, preferred combinations of embodiments are more preferred embodiments. In this specification, various physical properties and characteristic values ​​are given at 23°C unless otherwise specified. In the notation of groups (atomic groups) in this specification, notations that do not specify substitution or unsubstituted include both groups (atomic groups) with substituents and groups (atomic groups) without substituents. For example, "alkyl group" includes not only alkyl groups without substituents (unsubstituted alkyl groups) but also alkyl groups with substituents (substituted alkyl groups). In this specification, when notations that do not specify substitution or unsubstituted, unsubstituted is preferred. Examples of substituents in this specification are preferably halogen atoms, cyano groups, nitro groups, hydroxyl groups, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, heterocyclic groups, heterocyclic oxy groups, alkenyl groups, alkylsulfanyl groups, arylsulfanyl groups, acyl groups, or amino groups; more preferably halogen atoms, alkyl groups, alkoxy groups, aryl groups, aryloxy groups, alkenyl groups, or acyl groups; even more preferably alkyl groups, aryl groups, aryloxy groups, or alkenyl groups; and even more preferably alkyl groups. The formula weight of these substituents is preferably 15 or more, and preferably 200 or less. Formula weight refers to, for example, a methyl group (-CH ３ If so, the result is 15. These substituents may have further substituents, but it is preferable that they do not have substituents.

[0009] In this specification, "(meth)allyl" refers to both allyl and methallyl, or either of them; "(meth)acrylate" refers to both acrylate and methacrylate, or either of them; "(meth)acrylic" refers to both acrylic and methacrylic, or either of them; and "(meth)acryloyl" refers to both acryloyl and methacryloyl, or either of them.

[0010] In this specification, relative permittivity refers to the ratio of the permittivity of a material to the permittivity of a vacuum. In this specification, relative permittivity may also be simply referred to as "permittivity." Furthermore, unless otherwise specified, relative permittivity refers to the relative permittivity at a frequency of 10 GHz measured according to the cavity resonance perturbation method. In this specification, weight-average molecular weight and number-average molecular weight are measured according to paragraph 0259 of International Publication No. 2024 / 101237 unless otherwise specified.

[0011] In this specification, resin solids mean thermosetting resins, thermoplastic elastomers, and flame retardants, and do not include dispersants, catalysts, fillers, and solvents.

[0012] If the measurement methods, etc., described in the standards shown in this specification differ from year to year, unless otherwise specified, the standards as of January 1, 2024 shall apply. If the measurement methods, etc., described in the standards shown in this specification have been abolished as of January 1, 2024, the standards in effect at the time of abolition shall apply.

[0013] The resin composition of this embodiment comprises a thermosetting resin and a filler, wherein the curable resin comprises a maleimide compound, and the filler comprises a resin-containing shell and hollow resin particles having a hollow structure surrounded by the shell. With this configuration, it is possible to provide a resin composition that is low dielectric and has low thermal expansion when cured. That is, it is presumed that the hollow resin particles achieve low dielectric properties because they contain regions of air, bubbles, or vacuum within the particle. Furthermore, it is presumed that the hollow resin particles have low elasticity, which suppresses thermal expansion. Hollow inorganic particles can also be considered as hollow particles, but hollow inorganic particles tend to crack easily, and if hollow inorganic particles crack, the dielectric properties deteriorate. Under the above circumstances, it is presumed that in this embodiment, by using hollow resin particles, a resin composition that is low dielectric and has low thermal expansion when cured is obtained.

[0014] The embodiments of the present invention will be described in detail below, but the description of the constituent elements described below is merely one example of an embodiment of the present invention and is not limited to these.

[0015] <Thermosetting Resin> The resin composition of this embodiment includes a thermosetting resin. The thermosetting resin includes a maleimide resin. The thermosetting resin preferably further includes at least one selected from the group consisting of aromatic vinyl resins, cyanate ester compounds, (meth)allyl compounds, (meth)acrylate compounds, epoxy compounds, phenol compounds, oxetane compounds, benzoxazine compounds, arylcyclobutene compounds, perfluorovinyl ether resins, polyimide compounds, and indan resins; more preferably includes one or more selected from the group consisting of aromatic vinyl resins, cyanate ester compounds, epoxy compounds, and indan resins; even more preferably includes an aromatic vinyl resin; and even more preferably includes a maleimide compound, a polymer having a structural unit represented by formula (V), and a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus. Furthermore, it is more preferable that the thermosetting resin has a group that reacts with the carbon-carbon double bond contained in the resin contained in the shell of the hollow resin particles. Examples of thermosetting resins having groups that react with carbon-carbon double bonds in the resin contained in the shell of the hollow resin particles include at least one selected from the group consisting of maleimide compounds, aromatic vinyl resins, (meth)allyl compounds, (meth)acrylate compounds, and indan resins. In this embodiment, it is preferable that the thermosetting resin includes maleimide compounds and aromatic vinyl resins, and it is more preferable that, in addition to maleimide compounds, it includes at least one polymer having a constituent unit represented by formula (V) and a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminal. Furthermore, the resin composition of this embodiment may also be configured without polyimide resins, polyphenylene oxide resins, and cyanate ester compounds (cyanate resins) as thermosetting resins.

[0016] In the resin composition of this embodiment, it is preferable that the thermosetting resin is composed of 90% by mass or more of one or more thermosetting resins selected from the group consisting of maleimide compounds, polymers having structural units represented by formula (V), and polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more.

[0017] <<Maleimide Compound>> The resin composition of this embodiment contains a maleimide compound. In this embodiment, the maleimide compound is preferably a compound having one or more (preferably two or more, more preferably two to twelve, even more preferably two to six, even more preferably two to four, even more preferably two or three, and even more preferably two) maleimide groups in one molecule. More specifically, the maleimide compound preferably contains one or more selected from the group consisting of the compound represented by formula (M0), the compound represented by formula (M1), the compound represented by formula (M2), the compound represented by formula (M3), the compound represented by formula (M4), the compound represented by formula (M5), maleimide compound (M6), maleimide compound (M7), maleimide compound (M8), and maleimide compound (M9); more preferably contains one or more selected from the group consisting of the compound represented by formula (M1), the compound represented by formula (M2), the compound represented by formula (M3), the compound represented by formula (M4), the compound represented by formula (M5), and maleimide compound (M7); and even more preferably contains the compound represented by formula (M2) and / or maleimide compound (M7).

[0018] (In formula (M0), R ５１ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R ５２ Each of these independently represents a hydrogen atom or a methyl group, n １ (This represents an integer greater than or equal to 1.) R ５１Each of these is preferably independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and one of a methyl group, and even more preferably a hydrogen atom. ５２ It is preferable that it is a methyl group. １ n is preferably an integer from 1 to 10, more preferably an integer from 1 to 5, even more preferably an integer from 1 to 3, even more preferably 1 or 2, and even more preferably 1. The compound represented by formula (M0) may be a single compound or a mixture of two or more compounds. An example of a mixture is n １ A mixture of different compounds, R ５１ and / or R ５２ Examples include mixtures of compounds with different types of substituents, mixtures of compounds with different bonding positions (meta, para, ortho) between the maleimide group and the oxygen atom on the benzene ring, and mixtures of compounds in which two or more of the above differences are combined. The same applies to compounds represented by formulas (M1) to (M8) below.

[0019] (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ Each of these independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4-6 membered alicyclic group. R Ｍ７ and R Ｍ８ Each of these is independently an alkyl group. mx is 1 or 2, and lx is 0 or 1. Ｍ９ and R Ｍ１０ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ Each of these independently represents a hydrogen atom or an organic group. Ｍ１５each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group or a mercapto group. px represents an integer of 0 to 3. nx represents an integer of 1 to 20.)

[0020] In the formula, R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ each independently represent a hydrogen atom or an organic group. The organic group herein is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and a methyl group is particularly preferred among these. R Ｍ１ and R Ｍ３ each independently are preferably an alkyl group, and R Ｍ２ and R Ｍ４ are preferably a hydrogen atom. R Ｍ５ and R Ｍ６ each independently represent a hydrogen atom or an alkyl group, and is preferably an alkyl group. The alkyl group herein is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and a methyl group is particularly preferred among these. Ar Ｍ represents a divalent aromatic group, preferably a phenylene group, a naphthalenediyl group, a phenanthrenediyl group, or an anthracenediyl group, more preferably a phenylene group, and still more preferably an m-phenylene group. Ar Ｍ may have a substituent; the substituent is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and a methyl group is particularly preferred. However, Ar Ｍis preferably unsubstituted. A is an alicyclic group of a 4- to 6-membered ring, and a 5-membered alicyclic group (preferably a group that forms an indane ring together with a benzene ring) is more preferred. When A is a 5-membered alicyclic group that forms an indane ring together with a benzene ring, the low dielectric properties (Dk and / or Df) of the obtained cured product tend to be further improved. R Ｍ７ and R Ｍ８ are each independently an alkyl group, an alkyl group having 1 to 6 carbon atoms is preferred, an alkyl group having 1 to 3 carbon atoms is more preferred, and a methyl group is particularly preferred. mx is 1 or 2, and 2 is preferred. lx is 0 or 1, and 1 is preferred. R Ｍ９ and R Ｍ１０ each independently represent a hydrogen atom or an alkyl group, and an alkyl group is more preferred. The alkyl group herein is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and a methyl group is particularly preferred among these. R Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ each independently represent a hydrogen atom or an organic group. The organic group herein is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, still more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and a methyl group is particularly preferred among these. R Ｍ１２ and R Ｍ１３ each independently are preferably an alkyl group, and R Ｍ１１ and R Ｍ１４ are preferably a hydrogen atom. R Ｍ１５Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group, and is preferably an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, or an aryl group having 6 to 10 carbon atoms. px represents an integer from 0 to 3, preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 0. nx represents an integer from 1 to 20. nx may be an integer of 10 or less. The resin composition of this embodiment may contain only one compound represented by formula (M1) with at least two or more compounds having different nx values. When two or more types are included, the average value of nx (average number of repeating units) in the compound represented by formula (M1) in the resin composition is preferably 0.92 or higher, more preferably 0.95 or higher, even more preferably 1.0 or higher, and even more preferably 1.1 or higher, in order to obtain a low melting point (low softening point), low melt viscosity, and excellent handling properties. Furthermore, n is preferably 10.0 or less, more preferably 8.0 or less, even more preferably 7.0 or less, even more preferably 6.0 or less, and may also be 5.0 or less. The same applies to formula (M1-1), etc., which will be described later.

[0021] The compound represented by formula (M1) is preferably the compound represented by the following formula (M1-1). (In formula (M1-1), R Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ Each of these independently represents a hydrogen atom or an organic group. Ｍ２５ and R Ｍ２６ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ Each of these independently represents a hydrogen atom or an organic group. Ｍ３１ and R Ｍ３２Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ３３ , R Ｍ３４ , R Ｍ３５ , and R Ｍ３６ Each of these independently represents a hydrogen atom or an organic group. Ｍ３７ , R Ｍ３８ , and R Ｍ３９ Each of these independently represents either a hydrogen atom or an alkyl group. nx represents an integer between 1 and 20.

[0022] R in the formula Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ Each of these independently represents a hydrogen atom or an organic group. The organic group here is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, even more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably a methyl group, ethyl group, propyl group, or butyl group, and particularly preferably a methyl group. Ｍ２１ and R Ｍ２３ The alkyl group is preferred, R Ｍ２２ and R Ｍ２４ A hydrogen atom is preferred. Ｍ２５ and R Ｍ２６ Each of these independently represents a hydrogen atom or an alkyl group, with alkyl groups being preferred. Here, alkyl groups having 1 to 12 carbon atoms are preferred, alkyl groups having 1 to 6 carbon atoms are more preferred, and methyl, ethyl, propyl, and butyl groups are even more preferred, with methyl groups being particularly preferred. Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ Each of these independently represents a hydrogen atom or an organic group, with hydrogen atoms being preferred. The organic group here is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, even more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably a methyl group, ethyl group, propyl group, or butyl group, and particularly preferably a methyl group. Ｍ３１ and R Ｍ３２Each of these independently represents a hydrogen atom or an alkyl group, with alkyl groups being preferred. Here, alkyl groups having 1 to 12 carbon atoms are preferred, alkyl groups having 1 to 6 carbon atoms are more preferred, and methyl, ethyl, propyl, and butyl groups are even more preferred, with methyl groups being particularly preferred. Ｍ３３ , R Ｍ３４ , R Ｍ３５ , and R Ｍ３６ Each of these independently represents a hydrogen atom or an organic group. The organic group here is preferably an alkyl group, more preferably an alkyl group having 1 to 12 carbon atoms, even more preferably an alkyl group having 1 to 6 carbon atoms, even more preferably a methyl group, ethyl group, propyl group, or butyl group, and particularly preferably a methyl group. Ｍ３３ and R Ｍ３６ A hydrogen atom is preferred, R Ｍ３４ and R Ｍ３５ Alkyl groups are preferred. Ｍ３７ , R Ｍ３８ , and R Ｍ３９ Each of these independently represents either a hydrogen atom or an alkyl group, with alkyl groups being preferred. Here, alkyl groups having 1 to 12 carbon atoms are preferred, alkyl groups having 1 to 6 carbon atoms are more preferred, methyl groups, ethyl groups, propyl groups, and butyl groups are even more preferred, and among these, methyl groups are particularly preferred. nx represents an integer between 1 and 20. nx may also be an integer less than or equal to 10.

[0023] The compound represented by formula (M1-1) is preferably the compound represented by the following formula (M1-2). (In formula (M1-2), R Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ Each of these independently represents a hydrogen atom or an organic group. Ｍ２５ and R Ｍ２６ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ Each of these independently represents a hydrogen atom or an organic group. Ｍ３１ and R Ｍ３２Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ３３ , R Ｍ３４ , R Ｍ３５ , and R Ｍ３６ Each of these independently represents a hydrogen atom or an organic group. Ｍ３７ , R Ｍ３８ , and R Ｍ３９ Each of these independently represents either a hydrogen atom or an alkyl group. nx represents an integer between 1 and 20.

[0024] In formula (M1-2), R Ｍ２１ , R Ｍ２２ , R Ｍ２３ , R Ｍ２４ , R Ｍ２５ , R Ｍ２６ , R Ｍ２７ , R Ｍ２８ , R Ｍ２９ , R Ｍ３０ , R Ｍ３１ , R Ｍ３２ , R Ｍ３３ , R Ｍ３４ , R Ｍ３５ , R Ｍ３６ , R Ｍ３７ , R Ｍ３８ , R Ｍ３９ , and nx are R in equation (M1-1), respectively. Ｍ２１ , R Ｍ２２ , R Ｍ２３ , R Ｍ２４ , R Ｍ２５ , R Ｍ２６ , R Ｍ２７ , R Ｍ２８ , R Ｍ２９ , R Ｍ３０ , R Ｍ３１ , R Ｍ３２ , R Ｍ３３ , R Ｍ３４ , R Ｍ３５ , R Ｍ３６ , R Ｍ３７ , R Ｍ３８ , R Ｍ３９ , and are synonymous with nx, and the preferred range is also similar.

[0025] The compound represented by formula (M1-1) is more preferably the compound represented by the following formula (M1-3), and more preferably the compound represented by the following formula (M1-4). (In equation (M1-3), nx represents an integer between 1 and 20.) nx may also be an integer less than or equal to 10. (In equation (M1-4), nx represents an integer between 1 and 20, inclusive.)

[0026] The molecular weight of the compound represented by formula (M1) is preferably 500 or more, more preferably 600 or more, and even more preferably 700 or more. Setting it above the lower limit tends to further improve the low dielectric properties and low water absorption of the resulting cured product. Furthermore, the molecular weight of the compound represented by formula (M1) is preferably 10,000 or less, more preferably 9,000 or less, even more preferably 7,000 or less, even more preferably 5,000 or less, and even more preferably 4,000 or less. Setting it below the upper limit tends to further improve the heat resistance and handling properties of the resulting cured product.

[0027] (In formula (M2), R ５４ Each of these independently represents a hydrogen atom or a methyl group, n ４ n represents an integer greater than or equal to 1. ４ n is preferably an integer from 1 to 10, more preferably an integer from 1 to 5, even more preferably an integer from 1 to 3, even more preferably 1 or 2, and may be 1. The compound represented by formula (M2) is n ４ It may be a mixture of different compounds, and is preferable. Also, as mentioned in the section on the compound represented by formula (M0), it may be a mixture of compounds with other parts that are different.

[0028] (In formula (M3), R ５５ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, n ５ (This represents an integer between 1 and 10.) ５５ Each of these is preferably independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and one of a methyl group, and even more preferably a hydrogen atom.５ n5 is preferably an integer between 1 and 5, more preferably an integer between 1 and 3, and even more preferably 1 or 2. The compound represented by formula (M3) may be a mixture of compounds in which n5 is different, and is preferably a mixture. Also, as mentioned in the section on the compound represented by formula (M0), it may be a mixture of compounds in which other parts are different.

[0029] (In formula (M4), R ５６ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and R ５７ (Each of these independently represents either a hydrogen atom or a methyl group.)

[0030] (In formula (M5), R ５８ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R ５９ Each of these independently represents a hydrogen atom or a methyl group, n ６ (This represents an integer greater than or equal to 1.) R ５８ Each of these is preferably independently a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and one of a methyl group, and even more preferably a hydrogen atom. ５９ It is preferable that it is a methyl group. ６ n is preferably an integer from 1 to 10, more preferably an integer from 1 to 5, even more preferably an integer from 1 to 3, even more preferably 1 or 2, and may be 1. The compound represented by formula (M5) is n ６ It may be a mixture of different compounds, and is preferable. Also, as mentioned in the section on the compound represented by formula (M0), it may be a mixture of compounds with other parts that are different.

[0031] Maleimide compounds (M6) are compounds having a structural unit represented by formula (M6) and maleimide groups at both ends of the molecular chain. (In formula (M6), R ６１R represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. ６２ R represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. ６３ Each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms, or a linear or branched alkenyl group having 2 to 16 carbon atoms. Each independently represents an integer from 0 to 10.) Details of the maleimide compound (M6) and its preparation method can be found in paragraphs 0061 to 0066 of International Publication No. 2020 / 262577, which are incorporated herein by reference.

[0032] The maleimide compound (M7) is a maleimide compound that is reacted using an aromatic amine compound (a1) having one to three alkyl groups on its aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride as reaction raw materials (1). Preferably, the maleimide compound (M7) is a compound represented by formula (M7). (In the above formula (M7), R １ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, and R ２ Each of these independently represents an alkyl group, alkoxy group, or alkylthio group having 1 to 10 carbon atoms; an aryl group, aryloxy group, or arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group. ３ , R ４ , R ５ and R ６ Each of these independently represents a hydrogen atom or a methyl group, and R ３ and R ４ One side is a hydrogen atom, and the other side is a methyl group, R ５ and R ６ One side is a hydrogen atom, and the other side is a methyl group, X １ These are expressed independently as follows (x): (In formula (x), R ７ and R ８ Each of these independently represents a hydrogen atom or a methyl group, and R７ and R ８ One side is a hydrogen atom, and the other side is a methyl group, R ９ Each of these independently represents an alkyl group, alkoxy group, or alkylthio group having 1 to 10 carbon atoms; an aryl group, aryloxy group, or arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, where t represents an integer from 0 to 4. ) represents a substituent represented by r, where X １ X per benzene ring to which is bonded １ (This is the average number of substitutions, representing numbers from 0 to 4, where p represents an integer from 1 to 3, q ​​represents an integer from 0 to 4, and k represents an integer from 1 to 100.)

[0033] Details of the maleimide compound (M7) used in this embodiment can be found in Japanese Patent No. 7160151, which is incorporated herein by reference.

[0034] Maleimide compound (M7) is a maleimide compound obtained by using as reaction raw materials (1) an aromatic amine compound (a1) having 1 to 3 alkyl groups on the aromatic ring, an aromatic divinyl compound (a2) having 2 ethenyl groups, and maleic anhydride. Preferably, maleimide compound (M7) is a compound having the structure represented by formula (M7). (In the above formula (M7), R １ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, and R ２ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group. ３ , R ４ , R ５ and R ６ Each of these independently represents a hydrogen atom or a methyl group, and R ３ and R ４ One side is a hydrogen atom, and the other side is a methyl group, R ５ and R ６ One side is a hydrogen atom, and the other side is a methyl group, X１ These are expressed independently as follows (x): (In formula (x), R ７ and R ８ Each of these independently represents a hydrogen atom or a methyl group, and R ７ and R ８ One side is a hydrogen atom, and the other side is a methyl group, R ９ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, where t represents an integer from 0 to 4. ) represents a substituent represented by X １ X per benzene ring to which is bonded １ (This is the average number of substitutions, representing numbers from 0 to 4, where p represents an integer from 1 to 3, q ​​represents an integer from 0 to 4, and k represents an integer from 1 to 100.) R １ The alkyl group is preferably a C1-C5 alkyl group, more preferably a methyl group and an ethyl group, and even more preferably an ethyl group. ２ The alkyl group is preferably a C1-C5 alkyl group, and more preferably a methyl group and an ethyl group. ３ , R ４ , R ５ and R ６ R ３ and R ４ One side is a hydrogen atom, and the other side is a methyl group, R ５ and R ６Preferably, one of the elements is a hydrogen atom and the other is a methyl group. p is preferably 1. q is preferably an integer from 0 to 2, more preferably 0 or 1, and even more preferably 1. r is preferably 0. k is preferably an integer from 1 to 50, more preferably an integer from 1 to 10, and even more preferably an integer from 1 to 4. In this embodiment, the maleimide compound (M7) preferably consists only of the structure represented by formula (M7) and a terminal group, and the terminal group is preferably a hydrogen atom. An example of the maleimide compound (M7) is shown below as formula (M7-2). n is the same as k above. Formula (M7-2)

[0035] Details of the maleimide compound (M7) used in this embodiment can be found in Japanese Patent No. 7160151, which is incorporated herein by reference.

[0036] The maleimide compound (M8) is a bismaleimide compound having a hydrocarbon group in which eight or more atoms are linked in a linear chain, and is preferably a compound represented by formula (M8). Such maleimide compounds (M8) tend to have higher stress relaxation ability, and as a result, the thermal expansion coefficient of the resulting cured product tends to be lower, and the electrical properties such as dielectric constant and dielectric loss tangent tend to be better. (In formula (M8), R １ and R ３ Each of these independently represents a hydrocarbon group in which eight or more atoms are linked in a linear chain, and R ２ Each of these independently represents a substituted or unsubstituted cyclic hydrocarbon group that may contain 4 to 10 heteroatoms constituting the ring, and n represents a number from 1 to 10.

[0037] In equation (M8), R １ and R ３ However, it is an octylene group, R ２ However, it is preferable that the cycloalkylene group has an alkyl group having 6 to 8 carbon atoms as a substituent.

[0038] For maleimide compounds (M8), refer to the descriptions in paragraphs 0014 to 0022 of Japanese Patent Publication No. 2018-083893 and paragraphs 0012 to 0022 of Japanese Patent Publication No. 2018-090728, the contents of which are incorporated herein by reference.

[0039] Furthermore, maleimide compounds (maleimide compound (M9)) described in Japanese Patent Publication No. 2024-004392 and Japanese Patent Publication No. 2024-161436 can also be used, and this is incorporated herein by reference.

[0040] Maleimide compounds may be manufactured by known methods or commercially available products may be used. Examples of commercially available products include "BMI-80" manufactured by K.I. Chemicals Co., Ltd. as a compound represented by formula (M0), "NE-X-9470S" and "NE-X-9480S" manufactured by DIC Corporation as compounds represented by formula (M1), "BMI-2300" manufactured by Yamato Chemical Industries Co., Ltd. as a compound represented by formula (M2), "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd. as a compound represented by formula (M3), and a compound represented by formula (M4) Examples of compounds include "BMI-70" manufactured by Kei-I Kasei Co., Ltd., "BMI-5100" manufactured by Yamato Kasei Kogyo Co., Ltd., "MIR-5000" manufactured by Nippon Kayaku Co., Ltd. as a compound represented by formula (M5), "MIZ-001" manufactured by Nippon Kayaku Co., Ltd. as a maleimide compound (M6), "NE-X-9500" manufactured by DIC Corporation as a maleimide compound (M7), "SFR" manufactured by Resonac Corporation, and "BMI-689", "BMI-1500", "BMI-2500", "BMI-3000", and "BMI-5000" manufactured by DESIGNER MOLECULES INC. as maleimide compounds (M9) as "NE-X-9600" manufactured by DIC Corporation.

[0041] In addition to the above, as maleimide compounds, reference can be made to the compounds described in paragraphs 0061-0066 of International Publication No. 2020 / 262577 and Japanese Patent No. 7160151, and this information is incorporated herein by reference.

[0042] Furthermore, examples of maleimide compounds other than those mentioned above include compounds having two or more maleimide groups, specifically, m-phenylenebismaleimide, 2,2-bis(4-(4-maleimidophenoxy)-phenyl)propane, 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, and their prepolymers, as well as prepolymers of these maleimides and amines.

[0043] The maleimide group equivalent of the maleimide compound is preferably 130 g / eq. or more, more preferably 150 g / eq. or more, even more preferably 170 g / eq. or more, even more preferably 180 g / eq. or more, even more preferably 200 g / eq. or more, and also preferably 1000 g / eq. or less, more preferably 800 g / eq. or less, even more preferably 700 g / eq. or less, even more preferably 600 g / eq. or less, and even more preferably 500 g / eq. or less. Setting it above the lower limit tends to result in better low dielectric properties (Dk and / or Df, especially Df) of the resulting cured product. Setting it below the upper limit tends to result in better peel strength of the resulting cured product.

[0044] The lower limit of the maleimide compound content in the resin composition of this embodiment is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, and may be 30 parts by mass or more, 40 parts by mass or more, or 45 parts by mass or more, depending on the application. Setting the content above the lower limit tends to further improve the glass transition temperature and rigidity. A maleimide compound content of 1 part by mass or more tends to improve the flame resistance of the resulting cured product. The upper limit of the maleimide compound content is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, based on 100 parts by mass of resin solids. A maleimide compound content of 90 parts by mass or less tends to improve the peel strength and low water absorption of the cured product. The resin composition of this embodiment may contain only one type of maleimide compound, or it may contain two or more types. If two or more types are included, it is preferable that the total amount falls within the above range.

[0045] <<Aromatic Vinyl Resin>> An aromatic vinyl resin is, for example, a compound having a vinylaryl group and which hardens with heat. Specifically, the aromatic vinyl resin preferably contains one or more selected from the group consisting of polymers having a structural unit represented by formula (V) and polyphenylene ether compounds having a carbon-carbon unsaturated double bond at the terminal.

[0046] When the resin composition of this embodiment contains aromatic vinyl resin, its content is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more depending on the application, and may also be 95 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less depending on the application, even more preferably 55 parts by mass or less, even more preferably 50 parts by mass or less, and even more preferably 45 parts by mass or less. By setting the content of aromatic vinyl resin to be above the lower limit, compatibility and heat resistance tend to be further improved. Also, by setting the content of aromatic vinyl resin to be below the upper limit, low thermal expansion tend to be further improved. The resin composition of this embodiment may contain only one type of aromatic vinyl resin, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0047] <<<Polymer having a constituent unit represented by formula (V)>>> The resin composition of this embodiment may contain a polymer having a constituent unit represented by formula (V). By including a polymer having a constituent unit represented by formula (V), a resin composition with excellent low dielectric properties (low relative permittivity, low dielectric loss tangent) can be obtained. (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents the bond position.) An aromatic hydrocarbon linking group may consist only of an aromatic hydrocarbon which may have substituents, or it may consist of a combination of an aromatic hydrocarbon which may have substituents and another linking group, and it is preferable that it consists only of an aromatic hydrocarbon which may have substituents. The substituents that the aromatic hydrocarbon may have include substituent Z (for example, alkyl groups having 1 to 6 carbon atoms, alkenyl groups having 2 to 6 carbon atoms, alkynyl groups having 2 to 6 carbon atoms, alkoxy groups having 1 to 6 carbon atoms, hydroxyl groups, amino groups, carboxyl groups, halogen atoms, etc.). Furthermore, it is preferable that the above aromatic hydrocarbon does not have substituents. The aromatic hydrocarbon linking group is usually a divalent linking group.

[0048] Aromatic hydrocarbon linking groups specifically include phenylene groups, naphthalenediyl groups, anthracenediyl groups, phenanthrenediyl groups, biphenyldiyl groups, and fluoroorangeyl groups, which may have substituents, with the phenylene group being preferred among them, which may have substituents. The substituent Z mentioned above is an example of a substituent, but it is preferable that groups such as the phenylene group mentioned above do not have substituents.

[0049] A polymer having a structural unit represented by formula (V) more preferably contains at least one of the structural units represented by formula (V1), formula (V2), and formula (V3). * in the following formulas represents a bond position. Furthermore, the structural units represented by formulas (V1) to (V3) are sometimes collectively referred to as "structural unit (a)".

[0050] In formulas (V1) to (V3), L １The is an aromatic hydrocarbon linking group (preferably with 6 to 22 carbon atoms, more preferably with 6 to 18 carbon atoms, and even more preferably with 6 to 10 carbon atoms). Specifically, examples include phenylene group, naphthalenediyl group, anthracenediyl group, phenanthrenediyl group, biphenyldiyl group, and fluoradiyl group, which may have substituents, and among these, the phenylene group, which may have substituents, is preferred. The substituent is exemplified by the substituent Z mentioned above, but it is preferable that groups such as the phenylene group mentioned above do not have substituents. The compound that forms the constituent unit (a) is preferably a divinyl aromatic compound, such as divinylbenzene, bis(1-methylvinyl)benzene, divinylnaphthalene, divinylanthracene, divinylbiphenyl, and divinylphenanthrene. Among these, divinylbenzene is particularly preferred. One of these divinyl aromatic compounds may be used, or two or more may be used as needed. That is, it is preferable that the constituent unit (a) is a constituent unit derived from a divinyl aromatic compound.

[0051] As described above, the polymer having the constituent unit represented by formula (V) may be a homopolymer of the compound forming the constituent unit (a), or it may be a copolymer with a constituent unit derived from another monomer. When the polymer having the constituent unit represented by formula (V) is a copolymer, the copolymerization ratio is preferably 3 mol% or more, more preferably 5 mol% or more, even more preferably 10 mol% or more, and may be 15 mol% or more. The upper limit is preferably 90 mol% or less, more preferably 85 mol% or less, even more preferably 80 mol% or less, even more preferably 70 mol% or less, even more preferably 60 mol% or less, even more preferably 50 mol% or less, even more preferably 40 mol% or less, even more preferably 30 mol% or less, and may also be 25 mol% or less or 20 mol% or less.

[0052] Other monomer-derived structural units include structural unit (b) derived from an aromatic compound having one vinyl group (monovinyl aromatic compound).

[0053] The constituent unit (b) derived from the monovinyl aromatic compound is preferably a constituent unit represented by the following formula (V4).

[0054] In formula (V4), L ２ is an aromatic hydrocarbon linking group, and a specific example of a preferred one is the above L １ Examples include the following. * indicates the bonding position. R Ｖ１ R is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (preferably an alkyl group). Ｖ１ When it is a hydrocarbon group, its number of carbon atoms is preferably 1 to 6, and more preferably 1 to 3. Ｖ１ and L ２ It may have the substituent Z described above.

[0055] When a polymer having a structural unit represented by formula (V) is a copolymer containing structural unit (b) derived from a monovinyl aromatic compound, examples of monovinyl aromatic compounds include vinyl aromatic compounds such as styrene, vinylnaphthalene, and vinylbiphenyl; and nuclear alkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o,p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, methylvinylbiphenyl, and ethylvinylbiphenyl. The monovinyl aromatic compounds exemplified here may optionally have the above-mentioned substituent Z. Furthermore, one or more of these monovinyl aromatic compounds may be used. Among these, structural unit (b) preferably contains structural units derived from at least one selected from the group consisting of o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene, and more preferably further contains structural units derived from styrene in addition to structural units derived from at least one selected from the group consisting of o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene.

[0056] When a polymer having a structural unit represented by formula (V) is a copolymer containing structural unit (b), the copolymerization ratio of structural unit (b) is preferably 10 mol% or more, more preferably 15 mol% or more, and may be 20 mol% or more, 30 mol% or more, 40 mol% or more, 50 mol% or more, 60 mol% or more, 70 mol% or more, or 75 mol% or more. The upper limit is preferably 98 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less.

[0057] A polymer having a structural unit represented by formula (V) may have other structural units besides structural units (a) and (b). Examples of other structural units include structural unit (c) derived from a cycloolefin compound. Examples of cycloolefin compounds include hydrocarbons having a double bond in the ring structure. Specifically, examples include monocyclic cyclic olefins such as cyclobutene, cyclopentene, cyclohexene, and cyclooctene, as well as compounds having a norbornene ring structure such as norbornene and dicyclopentadiene, and cycloolefin compounds in which aromatic rings are fused, such as indene and acenaphthylene. Examples of norbornene compounds are those described in paragraphs 0037 to 0043 of Japanese Patent Application Publication No. 2018-039995, the contents of which are incorporated herein by reference. The cycloolefin compounds exemplified herein may further have the substituent Z described above.

[0058] When a polymer having a structural unit represented by formula (V) is a copolymer containing structural unit (c), the copolymerization ratio of structural unit (c) is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more. The upper limit is preferably 90 mol% or less, more preferably 80 mol% or less, even more preferably 70 mol% or less, and may also be 50 mol% or less, or 30 mol% or less.

[0059] A polymer having a structural unit represented by formula (V) may also incorporate structural unit (d) derived from a different polymerizable compound (hereinafter also referred to as "other polymerizable compound"). Examples of other polymerizable compounds (monomers) include compounds containing three vinyl groups. Specifically, examples include 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, and 1,2,4-trivinylcyclohexane. Alternatively, examples include ethylene glycol diacrylate, butadiene (e.g., 1,3-butadiene), isoprene, etc. The copolymerization ratio of structural unit (d) derived from the other polymerizable compound is preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less.

[0060] As one embodiment of a polymer having a structural unit represented by formula (V), a polymer is provided in which structural unit (a) is essential and which contains at least one of structural units (b) to (d). Furthermore, an embodiment is provided in which the sum of structural units (a) to (d) accounts for 95 mol% or more, and more preferably 98 mol% or more, of the total structural units. As another embodiment of a polymer having a structural unit represented by formula (V), structural unit (a) is essential, and it is preferable that the polymer contains 90 mol% or more, more preferably 95 mol% or more, of the total structural units excluding the terminals, structural units containing aromatic rings, and may also be a polymer of 100 mol%. When calculating the mol% per total structural unit, one structural unit is defined as one molecule of the monomer (e.g., divinyl aromatic compound, monovinyl aromatic compound, etc.) used in the production of the polymer having a structural unit represented by formula (V).

[0061] The method for producing a polymer having a constituent unit represented by formula (V) is not particularly limited and can be carried out by conventional methods. For example, a raw material containing a divinyl aromatic compound (and, if necessary, a monovinyl aromatic compound, a cycloolefin compound, etc.) can be polymerized in the presence of a Lewis acid catalyst. As the Lewis acid catalyst, a metal fluoride such as boron trifluoride or a complex thereof can be used.

[0062] The structure of the chain ends of a polymer having a constituent unit represented by formula (V) is not particularly limited, but with respect to the group derived from the above-mentioned divinyl aromatic compound, it can take the structure of formula (E1) below. Note that L in formula (E1) １ This is the same as defined in formula (V1) above. * indicates the bond position. *-CH=CH-L １ -CH=CH ２ (E1)

[0063] When a group derived from a monovinyl aromatic compound becomes the chain terminus, it can take the structure shown in formula (E2) below. ２ and R Ｖ１ These have the same meaning as defined in equation (V4) above. * represents the bond position. *-CH=CH-L ２ -R Ｖ１ (E2)

[0064] The molecular weight of the polymer having the constituent unit represented by formula (V) is preferably 300 or more, more preferably 500 or more, even more preferably 1,000 or more, and even more preferably 1,500 or more, in terms of number average molecular weight (Mn). The upper limit of the number average molecular weight is preferably 130,000 or less, more preferably 120,000 or less, even more preferably 110,000 or less, even more preferably 100,000 or less, and may also be 30,000 or less, 10,000 or less, or 5,000 or less. The molecular weight of the polymer having the constituent unit represented by formula (V) is preferably 3,000 or more, more preferably 5,000 or more, and even more preferably 10,000 or more, in terms of weight average molecular weight Mw. By setting the weight average molecular weight to be above the lower limit, the excellent low dielectric properties of the polymer having the constituent unit represented by formula (V), particularly Df and dielectric properties after moisture absorption, can be effectively exhibited in the cured product of the resin composition. The upper limit of the weight-average molecular weight Mw is preferably 130,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less, and even more preferably 50,000 or less. By keeping the weight-average molecular weight below the above upper limit, embedding defects tend to be less likely to occur when the prepreg or resin sheet is laminated onto a circuit forming substrate. The monodispersity (Mw / Mn), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), is preferably 100 or less, more preferably 50 or less, even more preferably 20 or less, and may also be 15 or less or 12 or less. As a lower limit, it is practical to be 1.1 or more, preferably 2.0 or more, more preferably 4 or more, even more preferably 5 or more, even more preferably 7 or more, and even more preferably 8 or more. The above Mw and Mn are measured according to the examples described later. When the resin composition of this embodiment contains two or more polymers having a structural unit represented by formula (V), it is preferable that the Mw, Mn, and Mw / Mn of the mixture satisfy the above range.

[0065] The equivalent amount of vinyl groups in a polymer having a constituent unit represented by formula (V) is preferably 200 g / eq. or more, more preferably 230 g / eq. or more, even more preferably 250 g / eq. or more, and may be 300 g / eq. or more, or 350 g / eq. or more. Furthermore, the equivalent amount of vinyl groups is preferably 1200 g / eq. or less, more preferably 1000 g / eq. or less, and may be 800 g / eq. or less, 600 g / eq. or less, 500 g / eq. or less, 400 g / eq. or less, or 350 g / eq. or less. When the equivalent amount of vinyl groups is above the above lower limit, the storage stability of the resin composition is improved and the fluidity of the resin composition tends to improve. As a result, moldability is improved, voids are less likely to occur when forming prepregs, etc., and a more reliable printed circuit board tends to be obtained. On the other hand, when the vinyl group equivalent is below the aforementioned upper limit, the heat resistance of the resulting cured product tends to improve.

[0066] Polymers having a constituent unit represented by formula (V) preferably have cured products that exhibit excellent low dielectric properties. For example, the cured product of a polymer having a constituent unit represented by formula (V) used in this embodiment preferably has a relative permittivity (Dk) at 10 GHz measured according to the cavity resonator perturbation method of 2.80 or less, more preferably 2.60 or less, even more preferably 2.50 or less, and even more preferably 2.40 or less. Furthermore, a practical lower limit for the relative permittivity is, for example, 1.80 or more. Furthermore, the cured product of a polymer having a constituent unit represented by formula (V) preferably has a dielectric loss tangent (Df) at 10 GHz measured according to the cavity resonator perturbation method of 0.0030 or less, more preferably 0.0020 or less, and even more preferably 0.0010 or less. Furthermore, a practical lower limit for the dielectric loss tangent is, for example, 0.0001 or more. The relative permittivity (Dk) and dielectric loss tangent (Df) are measured by the following method. 4.5 g of resin powder is spread into a stainless steel mold measuring 100 mm x 30 mm x 1.0 mm high, and placed in a vacuum press (manufactured by Kitagawa Seiki Co., Ltd.). The mold is then pressed at 200°C, 220°C, and 240°C for 1.5 hours at a surface pressure of 1.9 MPa to produce a cured plate. After downsizing the cured plate to a width of 1.0 mm, it is dried at 120°C for 60 minutes. The relative permittivity (Dk) and dielectric loss tangent (Df) after drying are then measured at 10 GHz using a perturbation cavity resonator. The measurement temperature is 23°C.

[0067] With respect to polymers having a constituent unit represented by formula (V) in this specification, reference can be made to and incorporated herein to the compounds and their synthesis reaction conditions described in paragraphs 0029 to 0058 of International Publication No. 2017 / 115813, the compounds and their synthesis reaction conditions described in paragraphs 0013 to 0058 of Japanese Patent Application Publication No. 2018-039995, the compounds and their synthesis reaction conditions described in paragraphs 0008 to 0043 of Japanese Patent Application Publication No. 2018-168347, the compounds and their synthesis reaction conditions described in paragraphs 0014 to 0042 of Japanese Patent Application Publication No. 2006-070136, the compounds and their synthesis reaction conditions described in paragraphs 0014 to 0061 of Japanese Patent Application Publication No. 2006-089683, and the compounds and their synthesis reaction conditions described in paragraphs 0008 to 0036 of Japanese Patent Application Publication No. 2008-248001.

[0068] When the resin composition of this embodiment contains a polymer having a structural unit represented by formula (V), the lower limit of its content is preferably 1 part by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, and may be 20 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. By setting the content of the polymer having a structural unit represented by formula (V) to be above the above lower limit, it tends to be possible to effectively achieve low dielectric properties, in particular, a low relative permittivity. Furthermore, the upper limit of the content of the polymer having a structural unit represented by formula (V) is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and may be 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, or 35 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. By setting the content of the polymer having a structural unit represented by formula (V) to be below the above upper limit, it tends to improve metal foil peel strength and low water absorption. The resin composition in this embodiment may contain only one polymer having a structural unit represented by formula (V), or it may contain two or more polymers. When it contains two or more polymers, it is preferable that the total amount is within the above range.

[0069] <<<Polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals>>> The resin composition of this embodiment preferably contains a polyphenylene ether compound having carbon-carbon unsaturated double bonds at the terminals, and more preferably contains a polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds at the terminals. The polyphenylene ether compound having two or more carbon-carbon unsaturated double bonds at the terminals preferably contains a polyphenylene ether compound having two or more groups represented by the formula (Rx-1) described later (preferably vinylbenzyl groups) at the terminals. By using these polyphenylene ether compounds, it is possible to more effectively improve the low dielectric properties (Dk and / or Df) and low water absorption of printed circuit boards and the like. The details of these will be explained below.

[0070] Examples of polyphenylene ether compounds having a carbon-carbon unsaturated double bond at the terminal include compounds having a phenylene ether skeleton represented by the following formula (X1).

[0071] (In formula (X1), R ２４ , R ２５ , R ２６ , and, R ２７ (These may be the same or different characters, and represent an alkyl group, aryl group, halogen atom, or hydrogen atom having six or fewer carbon atoms.)

[0072] A polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus is given by formula (X2): (In formula (X2), R ２８ , R ２９ , R ３０ , R ３４ , and, R ３５ R may be the same or different, and represents an alkyl group or phenyl group having 6 or fewer carbon atoms. ３１ , R ３２ , and, R ３３ These may be the same or different, and are a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group.) A repeating unit represented by formula (X3): (In formula (X3), R ３６, R ３７ , R ３８ , R ３９ , R ４０ , R ４１ , R ４２ , and, R ４３ ) may be the same or different, and is a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group. -A- is a straight, branched, or cyclic divalent hydrocarbon group having 20 or fewer carbon atoms. ) may further contain repeating units represented by ).

[0073] The polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus is preferably a modified polyphenylene ether compound (hereinafter sometimes referred to as "modified polyphenylene ether compound (g)") in which part or all of the terminus is functionalized with an ethylenically unsaturated group, and more preferably a modified polyphenylene ether compound having two or more vinylbenzyl groups at its terminus. By employing such a modified polyphenylene ether compound (g), it is possible to further reduce the dielectric loss tangent (Df) of the cured resin composition and to improve water absorption and peel strength. These modified polyphenylene ether compounds (g) may be used individually or in combination of two or more.

[0074] Examples of modified polyphenylene ether compounds (g) include polyphenylene ether compounds represented by formula (OP). (In formula (OP), X represents an aromatic group, and -(Y-O) ｎ１ The hyphen (-) represents the polyphenylene ether structure, where n1 is an integer from 1 to 100, and n2 is an integer from 1 to 4. Rx is the group represented by formula (Rx-1). (In formula (Rx-1), R １ , R ２ , and, R ３ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * represents the bonding site with the oxygen atom. Mc independently represents a hydrocarbon group with 1 to 12 carbon atoms. z represents an integer from 0 to 4. r represents an integer from 0 to 6.

[0075] The aromatic group represented by X may or may not have substituents on the benzene ring, but it is preferable that it does. If substituents are present, the substituent Z described above can be exemplified, but it is preferable that it be at least one selected from the group consisting of alkyl groups, aryl groups, and halogen atoms having 6 or fewer carbon atoms, more preferably an alkyl group having 3 or fewer carbon atoms, and even more preferably a methyl group. Also, the -(Y-O)n １ The polyphenylene ether structure represented by - may or may not have substituents on the benzene ring, but it is preferable that it does. If substituents are present, the substituent Z described above can be exemplified, but it is preferably an alkyl group or phenyl group having 6 or fewer carbon atoms, more preferably an alkyl group having 3 or fewer carbon atoms, and even more preferably a methyl group. １ and / or n ２ If n is an integer greater than or equal to 2, １ individual constituent units (Y-O) and / or n ２ Each constituent unit may be identical or different. ２ The number is preferably 2 or more, and more preferably 2.

[0076] In formula (Rx-1), R １ , R ２ , and, R ３ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. １ A hydrogen atom or an alkyl group is preferred, a hydrogen atom or a methyl group is more preferred, and a hydrogen atom is even more preferred. ２ and R ３ Each of these is independently preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. １ , R ２ , and, R ３ The number of carbon atoms in the alkyl group, alkenyl group, or alkynyl group is preferably 5 or less, and more preferably 3 or less.

[0077] In formula (Rx-1), r represents an integer from 0 to 6, and may be an integer of 1 or more, preferably an integer of 5 or less, more preferably an integer of 4 or less, even more preferably an integer of 3 or less, even more preferably 1 or 2, and even more preferably 1.

[0078] In formula (Rx-1), Mc independently represents a hydrocarbon group having 1 to 12 carbon atoms, preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a linear or branched alkyl group having 1 to 10 carbon atoms, even more preferably a methyl group, ethyl group, isopropyl group, isobutyl group, t-butyl group, pentyl group, octyl group, or nonyl group, and even more preferably a methyl group, ethyl group, isopropyl group, isobutyl group, or t-butyl group. In formula (Rx-1), z represents an integer from 0 to 4, preferably an integer from 0 to 3, more preferably an integer from 0 to 2, even more preferably 0 or 1, and even more preferably 0.

[0079] A specific example of the group represented by formula (Rx-1) is the vinylbenzyl group.

[0080] Examples of modified polyphenylene ether compounds (g) include the compound represented by formula (OP-1). (In formula (OP-1), X represents an aromatic group, -(Y-O)n ２ - represents the polyphenylene ether structure, R １ , R ２ , and, R ３ Each of these independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group, and n １ n represents an integer from 0 to 6, and n ２ n represents an integer between 1 and 100, and n ３(where represents an integer from 1 to 4.) The aromatic group represented by X may or may not have substituents on the benzene ring, but it is preferable that it does. If substituents are present, the substituent Z described above can be exemplified, but it is preferable that it be at least one selected from the group consisting of alkyl groups, aryl groups, and halogen atoms having 6 or fewer carbon atoms, more preferably an alkyl group having 3 or fewer carbon atoms, and even more preferably a methyl group. Also, the -(Y-O)n ２ The polyphenylene ether structure represented by - may or may not have substituents on the benzene ring, but it is preferable that it does. If substituents are present, the substituent Z described above can be exemplified, but it is preferably an alkyl group or phenyl group having 6 or fewer carbon atoms, more preferably an alkyl group having 3 or fewer carbon atoms, and even more preferably a methyl group. ２ and / or n ３ If n is an integer greater than or equal to 2, ２ individual constituent units (Y-O) and / or n ３ Each constituent unit may be identical or different. ３ The number is preferably 2 or more, and more preferably 2.

[0081] In this embodiment, the modified polyphenylene ether compound (g) is preferably a compound represented by formula (OP-2). Here, -(O-X-O)- is equation (OP-3): (In formula (OP-3), R ４ , R ５ , R ６ , R ９ , R １０ , and, R １１ These may be the same or different alkyl groups or phenyl groups having 6 or fewer carbon atoms. ７ , and, R ９ These may be the same or different, and are a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group.) and / or formula (OP-4): (In formula (OP-4), R １２ , R １３ , R １４ , R１５ , R １６ , R １７ , R １８ , and, R １９ (These may be the same or different, and are a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group.) -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or fewer carbon atoms.

[0082] Also, -(Y-O)- is given by equation (OP-5): (In formula (OP-5), R ２０ , R ２１ These may be the same or different alkyl groups or phenyl groups having 6 or fewer carbon atoms. ２２ , R ２３ These may be the same or different, and are a hydrogen atom, an alkyl group having 6 or fewer carbon atoms, or a phenyl group. It is preferable that it be represented as ). In particular, R ２０ and R ２１ Each of these groups independently has one or more methyl and / or cyclohexyl groups. This increases the rigidity of the resulting resin molecule. Since molecules with high rigidity have lower mobility than molecules with low rigidity, the relaxation time during dielectric relaxation is longer, resulting in excellent low dielectric properties (Dk and / or Df, especially Dk), which is therefore preferable. An example of formula (OP-5) is shown below. For polyphenylene ether compounds having the above structure, please refer to the description in Japanese Patent Application Publication No. 2019-194312, which is incorporated herein by reference.

[0083] In formula (OP-2), a and b each independently represent integers from 0 to 100, and at least one of a and b is an integer from 1 to 100. Preferably, a and b are integers from 0 to 50, more preferably from 1 to 30, and preferably from 1 to 10. When a and / or b are integers of 2 or more, the 2 or more -(Y-O)- may each independently consist of one type of structure, or two or more structures may be arranged in a block or randomly. Furthermore, when multiple compounds represented by formula (OP-2) are included, the average value of a is preferably 1 < a < 10, and the average value of b is preferably 1 < b < 10.

[0084] Examples of the -A- in formula (OP-4) include, but are not limited to, divalent organic groups such as methylene group, ethylidene group, 1-methylethylidene group, 1,1-propyridene group, 1,4-phenylenebis(1-methylethylidene) group, 1,3-phenylenebis(1-methylethylidene) group, cyclohexylidene group, phenylmethylene group, naphthylmethylene group, and 1-phenylethylidene group.

[0085] Among the compounds represented by the above formula (OP-2), R ４ , R ５ , R ６ , R ９ , R １０ , R １１ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ , R ２０ , and, R ２１ is an alkyl group having 3 or fewer carbon atoms, R ７ , R ８ , R ２２ , and, R ２３A polyphenylene ether compound in which is a hydrogen atom or an alkyl group having 3 or fewer carbon atoms is preferred, and in particular, the -(O-X-O)- represented by formula (OP-3) or formula (OP-4) is preferably formula (OP-9), formula (OP-10), and / or formula (OP-11), and the -(Y-O)- represented by formula (OP-5) is preferably formula (OP-12) or formula (OP-13). When a and / or b are integers of 2 or more, the 2 or more -(Y-O)- may each independently be a structure in which two or more of formula (OP-12) and / or formula (OP-13) are arranged, or a structure in which formula (OP-12) and formula (OP-13) are arranged in a block or randomly.

[0086] (In formula (OP-10), R ４４ , R ４５ , R ４６ , and, R ４７ A is a hydrogen atom or a methyl group, and may be the same or different. B is a straight, branched, or cyclic divalent hydrocarbon group with 20 or fewer carbon atoms. Specific examples of B are the same as the specific examples of A in formula (OP-4). (In formula (OP-11), -B- is a straight-chain, branched, or cyclic divalent hydrocarbon group having 20 or fewer carbon atoms.) Specific examples of -B- are the same as the specific examples of -A- in formula (OP-4).

[0087] The modified polyphenylene ether compound (g) is more preferably a compound represented by formula (OP-14) and / or a compound represented by formula (OP-15), and even more preferably a compound represented by formula (OP-15). (In formula (OP-14), a and b each independently represent integers from 0 to 100, and at least one of a and b is an integer from 1 to 100.) In formula (OP-14), a and b are each independently equivalent to a and b in formula (OP-2), and the preferred ranges are also the same. (In formula (OP-15), a and b each independently represent integers from 0 to 100, and at least one of a and b is an integer from 1 to 100.) In formula (OP-15), a and b are each independently equivalent to a and b in formula (OP-2), and the preferred ranges are also the same.

[0088] Furthermore, the polyphenylene ether compound used in this embodiment may also be a compound represented by formula (OP-16). (In formula (OP-16), a and b each independently represent integers between 0 and 100, and at least one of the two as and bs is an integer between 1 and 100.)

[0089] Polyphenylene ether compounds having a carbon-carbon unsaturated double bond at the terminal may be produced by known methods or commercially available products may be used. Examples of commercially available products include "OPE-2St1200" and "OPE-2St2200" from Mitsubishi Gas Chemical Company, which are modified polyphenylene ether compounds with vinyl benzyl groups at the terminal. Alternatively, as modified polyphenylene ether compounds with vinyl benzyl groups at the terminal, such as "SA90" from SABIC Innovative Plastics, can be used, which are obtained by modifying polyphenylene ether compounds with hydroxyl groups at the terminal to vinyl benzyl groups using vinyl benzyl chloride or the like.

[0090] Further details regarding polyphenylene ether compounds having a terminal carbon-carbon unsaturated double bond can be found in Japanese Patent Publication No. 2006-028111, Japanese Patent Publication No. 2018-131519, International Publication No. 2019-138992, and International Publication No. 2022-054303, the contents of which are incorporated herein by reference.

[0091] The number-average molecular weight in polystyrene terms of a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus (preferably a modified polyphenylene ether compound (g)) determined by GPC (gel permeation chromatography) (details follow the method described in the examples below) is preferably 500 to 3,000. A number-average molecular weight of 500 or more tends to further suppress stickiness when the resin composition of this embodiment is formed into a coating film. Furthermore, a number-average molecular weight of 3,000 or less tends to further improve solubility in solvents. In addition, the weight-average molecular weight in polystyrene terms of a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus (preferably a modified polyphenylene ether compound (g)) determined by GPC (details follow the method described in the examples below) is preferably 800 to 10,000, and more preferably 800 to 5,000. When the weight-average molecular weight is above the lower limit, the relative permittivity (Dk) and dielectric loss tangent (Df) of the cured resin composition tend to be lower, and when it is below the upper limit, the solubility in solvents, viscosity, and moldability of the resin composition when producing varnishes, etc., as described later tend to be improved.

[0092] Furthermore, for polyphenylene ether compounds having carbon-carbon unsaturated double bonds at their terminals (preferably modified polyphenylene ether compounds (g)), the equivalent amount of the terminal carbon-carbon unsaturated double bonds is preferably 400 to 5000 g per carbon-carbon unsaturated double bond, and more preferably 400 to 2500 g. When the equivalent amount of the terminal carbon-carbon unsaturated double bonds is above the lower limit, the dielectric constant (Dk) and dielectric loss tangent (Df) of the cured resin composition tend to be lower, and when it is below the upper limit, the solubility in solvents, viscosity, and moldability of the resin composition tend to be improved.

[0093] The functional group equivalent (carbon-carbon unsaturated double bond equivalent) of a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus is calculated by determining the amount of double bonds from the measurement results using an infrared spectrometer and then taking the reciprocal. The double bond equivalent [g / eq.] was determined as follows: The weight of the polyphenylene ether compound powder was weighed and recorded. After placing this powder in a volumetric flask, the measurement sample was prepared by making up the volume with carbon disulfide to a predetermined level. This sample solution was placed in a measurement cell and set in an infrared spectrophotometer (FT / IR-4600, manufactured by JASCO Corporation). Subsequently, infrared spectroscopic measurement of the sample solution was performed. In the case of a vinyl group in a polyphenylene ether compound, the value was 905 cm⁻¹. －１ Record the peak area of ​​the spectrum in the vicinity. When the carbon-carbon unsaturated double bond is a methacrylic group, the peak area is 1640 cm⁻¹. －１ The peak area of ​​the spectrum in the vicinity is recorded. From this area value and the calibration curve, the double bond concentration [mol / L] is determined as a measured value. Next, the double bond equivalent is calculated using the following formula: Double bond equivalent [g / eq.] = Powder weight in the measurement sample [g] / Double bond concentration [mol / L] × Volume of measurement sample liquid [L] The functional group equivalent of other thermosetting compounds other than polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals can also be measured following the above method. However, for compounds (monomers) that can be expressed by a single molecular weight, the value obtained by (theoretical molecular weight ÷ number of functional groups) shall be used preferentially. If two or more other thermosetting compounds are included, the functional group equivalent of the other thermosetting compounds shall be the sum (weighted average) of the values ​​obtained by multiplying the functional group equivalent of each other thermosetting compound by its mass fraction.

[0094] If the resin composition of this embodiment contains a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus, the lower limit of its content is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 7 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. By setting the content of the polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus to be above the lower limit, the moldability of the resin composition, the heat resistance, low water absorption, and low dielectric properties (Dk and / or Df) of the resulting cured product tend to be further improved. Furthermore, the upper limit of the content of the polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, per 100 parts by mass of resin solids in the resin composition, and may also be 70 parts by mass or less, 60 parts by mass or less, 50 parts by mass or less, 40 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, or 15 parts by mass or less. By keeping the polyphenylene ether compound content below the upper limit, the low dielectric properties (especially low dielectric loss tangent) and chemical resistance of the resulting cured product tend to improve. The resin composition in this embodiment may contain only one polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus, or it may contain two or more. When two or more are included, it is preferable that the total amount is within the above range.

[0095] In addition to the above, as aromatic vinyl resins, reference can be made to paragraphs 0011-0025 of International Publication No. 2023 / 176766, paragraphs 0012-0033 of International Publication No. 2023 / 176764, paragraphs 0012-0033 of International Publication No. 2023 / 176763, and paragraphs 0026-0043 of International Publication No. 2023 / 176765, which are incorporated herein by reference.

[0096] <<Cyanate Ester Compounds>> The resin composition of this embodiment may contain cyanate ester compounds. The cyanate ester compound in this embodiment is not particularly limited as long as it contains one or more cyanate groups (preferably two or more, more preferably two to twelve, even more preferably two to six, even more preferably two to four, even more preferably two or three, and even more preferably two) in one molecule, and compounds commonly used in the field of printed circuit boards can be widely used. Furthermore, it is preferable that the cyanate ester compound is a compound in which the cyanate group is directly bonded to an aromatic skeleton (aromatic ring). Preferred cyanate ester compounds in this embodiment include, for example, at least one selected from the group consisting of phenol novolac type cyanate ester compounds, naphthol aralkyl type cyanate ester compounds (naphthol aralkyl type cyanates), naphthylene ether type cyanate ester compounds, biphenyl aralkyl type cyanate ester compounds, xylene resin type cyanate ester compounds, trisphenolmethane type cyanate ester compounds, adamantane skeleton type cyanate ester compounds, bisphenol M type cyanate ester compounds, bisphenol A type cyanate ester compounds, and diallylbisphenol A type cyanate ester compounds. Among these, from the viewpoint of further improving the low water absorption of the resulting cured product, it is more preferable to use at least one selected from the group consisting of phenol novolac type cyanate ester compounds, naphthol aralkyl type cyanate ester compounds, naphthylene ether type cyanate ester compounds, xylene resin type cyanate ester compounds, bisphenol M type cyanate ester compounds, bisphenol A type cyanate ester compounds, and diallylbisphenol A type cyanate ester compounds. It is even more preferable to use at least one selected from the group consisting of phenol novolac type cyanate ester compounds and naphthol aralkyl type cyanate ester compounds, and even more preferable to use a naphthol aralkyl type cyanate ester compound. These cyanate ester compounds may be prepared by known methods or commercially available products may be used.Furthermore, cyanate ester compounds having a naphthol aralkyl skeleton, naphthylene ether skeleton, xylene skeleton, trisphenolmethane skeleton, or adamantane skeleton tend to have a relatively large number of functional group equivalents and fewer unreacted cyanate ester groups, resulting in cured resin compositions using these compounds exhibiting even greater low water absorption. In addition, the presence of an aromatic skeleton or adamantane skeleton tends to further improve plating adhesion.

[0097] As naphthol aralkyl type cyanate ester compounds, compounds represented by the following formula (1) are more preferred. (In formula (1), R 3 Each of these independently represents either a hydrogen atom or a methyl group, and n3 represents an integer greater than or equal to 1.

[0098] In formula (1), R 3 Each of these independently represents either a hydrogen atom or a methyl group, with hydrogen atoms being preferred. In formula (1), n3 is an integer of 1 or more, preferably an integer between 1 and 20, more preferably an integer between 1 and 10, and even more preferably an integer between 1 and 6.

[0099] Furthermore, while the novolac-type cyanate ester compound is not particularly limited, for example, a compound represented by the following formula (VII) is preferred. (In formula (VII), R ６ Each of these independently represents either a hydrogen atom or a methyl group, and n7 represents an integer greater than or equal to 1.

[0100] In formula (VII), R ６ Each of these independently represents either a hydrogen atom or a methyl group, with hydrogen atoms being preferred. In formula (VII), n7 is an integer of 1 or more, preferably an integer between 1 and 20, more preferably an integer between 1 and 10, and even more preferably an integer between 1 and 6.

[0101] As the bisphenol A type cyanate ester compound, one or more compounds selected from the group consisting of 2,2-bis(4-cyanatophenyl)propane and 2,2-bis(4-cyanatophenyl)propane prepolymers may be used.

[0102] The resin composition of this embodiment preferably contains a cyanate ester compound in a range that does not impair the effects of the present invention. When the resin composition of this embodiment contains a cyanate ester compound, the lower limit of its content is preferably 0.1 parts by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. When the cyanate ester compound content is 0.1 parts by mass or more, the heat resistance, flame resistance, chemical resistance, low dielectric properties (low relative permittivity, low dielectric loss tangent), and insulation properties of the resulting cured product tend to improve. When the resin composition of this embodiment contains a cyanate ester compound, the upper limit of its content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. The resin composition of this embodiment may contain only one type of cyanate ester compound, or it may contain two or more types. If two or more types are included, it is preferable that the total amount falls within the above range.

[0103] Furthermore, the resin composition in this embodiment may also be substantially free of cyanate ester compounds. Substantially free means that the cyanate ester compound content is less than 0.1 parts by mass per 100 parts by mass of resin solids in the resin composition, preferably less than 0.01 parts by mass, and even more preferably less than 0.001 parts by mass.

[0104] <<Epoxy Compound>> The resin composition of this embodiment may contain an epoxy compound. The epoxy compound is not particularly limited as long as it is a compound or resin having one or more epoxy groups in one molecule (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, even more preferably 2 or 3, and even more preferably 2), and compounds commonly used in the field of printed circuit boards can be widely used. Examples of the epoxy compounds include phenol novolac type epoxy resins, bisphenol A novolac type epoxy resins, glycidyl ester type epoxy resins, aralkyl novolac type epoxy resins, biphenyl aralkyl type epoxy resins, naphthylene ether type epoxy resins, cresol novolac type epoxy resins, polyfunctional phenol type epoxy resins, naphthalene type epoxy resins, anthracene type epoxy resins, naphthalene skeleton-modified novolac type epoxy resins, phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, dicyclopentadiene type epoxy resins, biphenyl type epoxy resins, alicyclic epoxy resins, polyol type epoxy resins, phosphorus-containing epoxy resins, compounds in which double bonds of glycidylamine, glycidyl esters, butadiene, etc. are epoxidized, and compounds obtained by the reaction of hydroxyl group-containing silicone resins with epichlorohydrin. Using these improves the moldability and adhesion of the resin composition. Among these, from the viewpoint of further improving flame retardancy and heat resistance, the epoxy compound is preferably one or more selected from the group consisting of biphenylaralkyl epoxy resin, naphthylene ether epoxy resin, polyfunctional phenolic epoxy resin, and naphthalene epoxy resin, and more preferably a biphenylaralkyl epoxy resin.

[0105] If the resin composition of this embodiment contains an epoxy compound, its content is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. A content of 0.1 parts by mass or more of the epoxy compound tends to improve the metal foil peel strength and toughness. The upper limit of the epoxy compound content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and may also be 8 parts by mass or less, or 5 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. A content of 50 parts by mass or less of the epoxy compound tends to improve the electrical properties of the resulting cured product. The resin composition of this embodiment may contain only one type of epoxy compound, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range. Furthermore, the resin composition of this embodiment may also be configured to substantially not contain any epoxy compound. "Substantially absent" means that the epoxy compound content is less than 0.1 parts by mass per 100 parts by mass of resin solids in the resin composition, preferably less than 0.01 parts by mass, and even more preferably less than 0.001 parts by mass. Substantially absent epoxy compounds tend to further improve the low dielectric properties (Dk and / or Df) of the cured product. That is, because epoxy groups are highly polar, the absence of such thermosetting compounds tends to enable the achievement of low dielectric properties (Dk and / or Df) in the cured product.

[0106] <<Indan Resin>> Indan resin is preferably a resin having an indan skeleton (excluding any of the thermosetting resins mentioned above), having end groups represented by formula (T1), and having an indan skeleton (in this specification, it may simply be referred to as "resin (A)"). (In formula (T1), Ma represents a hydrocarbon group having 1 to 12 carbon atoms, which may be independently substituted with a halogen atom, and x represents an integer from 0 to 4. * represents the bonding position with other sites.)

[0107] In formula (T1), a methyl group or an ethyl group is particularly preferred as Ma.

[0108] x is preferably an integer between 0 and 3, more preferably an integer between 0 and 2, even more preferably 0 or 1, and even more preferably 0.

[0109] Resin (A) may have terminal groups represented by formula (T1) at all of its ends, or at only some of its ends, for each resin molecule. Preferably, the resin molecule of resin (A) contains two terminal groups represented by formula (T1).

[0110] Resin (A) has an indan skeleton. While it is not particularly limited as long as at least one of the resin molecules contained in resin (A) has at least one indan skeleton, the number of indan skeletons in the resin molecules of resin (A) is preferably one or more per molecule, and more preferably 1 to 20. This configuration tends to more effectively exhibit the effects of the present invention.

[0111] The resin (A) preferably contains a constituent unit represented by formula (Txn). (In formula (T x n), n is the average number of repeating units, representing a number greater than 0 and less than or equal to 20. Ma represents a hydrocarbon group having 1 to 12 carbon atoms, which may be independently substituted with halogen atoms. x represents an integer from 0 to 4.)

[0112] In formula (Txn), Ma is particularly preferably a methyl group or an ethyl group.

[0113] x is preferably an integer between 0 and 3, more preferably an integer between 0 and 2, even more preferably 0 or 1, and even more preferably 0.

[0114] The proportion of the constituent unit represented by formula (Txn) in 100 parts by mass of resin (A) is preferably 20 parts by mass or more, more preferably 25 parts by mass or more, even more preferably 34 parts by mass or more, even more preferably 45 parts by mass or more, even more preferably 50 parts by mass or more, even more preferably 55 parts by mass or more, and even more preferably 60 parts by mass or more, 65 parts by mass or more, and may also be 70 parts by mass or more, 75 parts by mass or more, and also preferably 100 parts by mass or less, and may be 95 parts by mass or less, 90 parts by mass or less, 85 parts by mass or less, 82 parts by mass or less, or 80 parts by mass or less.

[0115] Resin (A) more preferably contains a resin represented by formula (T1-1), and more preferably contains a resin represented by formula (T1-1-2). (In formula (T1-1), R is a group containing the constituent unit represented by formula (Tx). Ma represents a hydrocarbon group having 1 to 12 carbon atoms, which may each be independently substituted with a halogen atom. x is an integer from 0 to 4.) In formula (T1-1), Ma and x are the same as Ma and x in formula (T1), and the preferred ranges are also the same. (In formula (T1-1-2), R is a group containing the constituent unit represented by formula (Tx).) (In formula (Tx), n, o, and p are the average number of repeating units, where n is a number greater than 0 and less than or equal to 20, and o and p each independently represent numbers from 0 to 20, with 1.0 ≤ n + o + p ≤ 20.0. Ma each independently represents a hydrocarbon group having 1 to 12 carbon atoms, which may be substituted with halogen atoms. x represents an integer from 0 to 4. Constituent units (a), (b), and (c) are each bonded to constituent units (a), (b), (c), or other groups by *, and each constituent unit may be bonded randomly.)

[0116] In formula (Tx), n, o, and p each represent the average number of repeating units in all molecules in the resin. In formula (Tx), the sum of n, o, and p is preferably 1.1 ≤ n + o + p, and more preferably 3.3 ≤ n + o + p. Furthermore, in formula (Tx), the sum of n, o, and p is preferably n + o + p ≤ 20.0, and more preferably n + o + p ≤ 6.4. The sum of n, o, and p can be calculated by the method described in the examples of International Publication No. 2024 / 101237.

[0117] The indan resin used in this embodiment may also be a compound having an indan skeleton with a carbon-carbon unsaturated double bond at its terminus. Examples of such compounds can be found in paragraphs 0011-0025 of International Publication No. 2023 / 176766, paragraphs 0012-0033 of International Publication No. 2023 / 176764, paragraphs 0012-0033 of International Publication No. 2023 / 176763, and paragraphs 0026-0043 of International Publication No. 2023 / 176765, the contents of which are incorporated herein by reference.

[0118] If the resin composition of this embodiment contains indan resin, its content is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. The upper limit of the indan resin content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and may also be 8 parts by mass or less, or 5 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. The resin composition of this embodiment may contain only one type of indan resin, or it may contain two or more types. If it contains two or more types, it is preferable that the total amount is within the above range. Furthermore, the resin composition of this embodiment may also be configured to substantially not contain indan resin. Substantially not containing indan resin means that the indan resin content is less than 0.1 parts by mass per 100 parts by mass of resin solids in the resin composition, preferably less than 0.01 parts by mass, and even more preferably less than 0.001 parts by mass.

[0119] <Filler> The resin composition of this embodiment may contain a filler. By including a filler, the physical properties of the resin composition and its cured product, such as dielectric properties (relative permittivity and / or dielectric loss tangent), flame resistance, and low thermal expansion, can be further improved. In this embodiment, it is preferable that the filler includes a resin-containing shell and hollow resin particles having a hollow structure surrounded by the shell. Furthermore, the resin composition of this embodiment may contain other fillers besides the hollow resin particles, and it is preferable that it contains other fillers besides the hollow resin particles. The details of these will be explained below.

[0120] <<Hollow Resin Particles>> The resin composition of this embodiment includes, as a filler, a resin-containing shell and hollow resin particles having a hollow structure surrounded by the shell. The hollow resin particles used in this embodiment preferably have a porosity of 50% or more. The porosity of the hollow resin particles used in this embodiment is more preferably 60% or more, even more preferably 65% ​​or more, and even more preferably 70% or more. By having a porosity above the above lower limit, the hollow resin particles tend to have excellent dielectric properties, as well as excellent lightness and heat insulation properties. The upper limit of the porosity of the hollow resin particles is not particularly limited, but from the viewpoint of suppressing a decrease in the strength of the hollow resin particles and making them less susceptible to crushing, it is preferably 90% or less, more preferably 85% or less, and even more preferably 80% or less.

[0121] The porosity of hollow resin particles is 100 - (apparent density D) of the hollow resin particles. １ / True density D ０ This value is calculated from ) × 100. Apparent density D of hollow resin particles. １ The measurement method is as follows: First, the volume 100 cm ３ Approximately 30 cm in a volumetric flask ３ Fill the volumetric flask with hollow resin particles and accurately weigh the mass of the filled hollow resin particles. Next, carefully fill the volumetric flask filled with hollow resin particles to the mark with isopropanol, taking care not to introduce air bubbles. Accurately weigh the mass of isopropanol added to the volumetric flask and calculate the apparent density D of the hollow resin particles based on the following formula (I). １ (g / cm３ Calculate the apparent density D. Equation (I) Apparent density D １ = [Mass of hollow resin particles] / (100 - [Mass of isopropanol] / [Specific gravity of isopropanol at measurement temperature]) Apparent density D １ This corresponds to the specific gravity of the entire hollow resin particle, assuming that the hollow portion is considered to be part of the hollow resin particle.

[0122] True density D of hollow resin particles ０ The measurement method is as follows: After pre-crushing the hollow resin particles, a volume of 100 cm³ is used. ３ Fill a volumetric flask with approximately 10 g of crushed hollow resin particles and accurately weigh the mass of the crushed particles. Then, add isopropanol to the volumetric flask in the same manner as the apparent density measurement described above, accurately weigh the mass of the isopropanol, and calculate the true density D of the hollow resin particles based on the following formula (II). ０ (g / cm ３ ) is calculated. Equation (II) True density D ０ = [Mass of crushed hollow resin particles] / (100 - [Mass of isopropanol] / [Specific gravity of isopropanol at measurement temperature]) True density D ０ This corresponds to the specific gravity of only the shell portion of the hollow resin particles. As is clear from the above measurement method, true density D ０ In calculating this, the hollow portion is not considered part of the hollow resin particles.

[0123] The porosity (%) of hollow resin particles is equal to the apparent density D of the hollow resin particles. １ and true density D ０ Therefore, it is calculated by the following formula (III). Formula (III) Porosity (%) = 100 - (Apparent density D １ / True density D ０ ) × 100

[0124] The hollow resin particles used in this embodiment preferably have a lower limit of volume-average particle size of 1.0 μm or more, more preferably 1.5 μm or more, and even more preferably 2.0 μm or more. On the other hand, the upper limit of volume-average particle size of the hollow resin particles is preferably 10.0 μm or less, more preferably 8.0 μm or less, and even more preferably 6.0 μm or less. When the volume-average particle size of the hollow resin particles is above the lower limit, the aggregation of the hollow resin particles becomes smaller, and they tend to exhibit excellent dispersibility. When the volume-average particle size of the hollow resin particles is below the upper limit, variations in shell thickness are suppressed, a uniform shell is easily formed, and the hollow resin particles become less prone to crushing, resulting in a tendency to have high mechanical strength. Furthermore, hollow resin particles with a volume-average particle size within the above range have sufficiently small particle sizes and are therefore suitable for use as substrate materials for electronic circuit boards and the like, and can be added to thin, small substrates.

[0125] The specific gravity of the hollow resin particles used in this embodiment is preferably 0.2 or higher, more preferably 0.22 or higher, preferably 0.5 or lower, and more preferably 0.4 or lower. When the resin composition of this embodiment contains two or more types of hollow resin particles, it is preferable that the weighted average value falls within the above range.

[0126] The hollow resin particles used in this embodiment preferably include a polymer in which the shell is a polymer in which hydrocarbon monomer units are present in a proportion of 96 to 100% by mass, and 96 to 100% by mass of the hydrocarbon monomer units and other constituent units are crosslinkable monomer units. A hydrocarbon monomer is a polymerizable monomer consisting of carbon and hydrogen. Examples of hydrocarbon monomers include aromatic divinyl monomers such as divinylbenzene, ethyl vinylbenzene, divinyl biphenyl, and divinylnaphthalene; linear or branched diolefins such as butadiene, isoprene, 2,3-dimethylbutadiene, pentadiene, and hexadiene; and diene monomers such as alicyclic diolefins such as dicyclopentadiene, cyclopentadiene, and ethylidenetetracyclododecene; with divinylbenzene being preferred. Non-crosslinkable hydrocarbon monomers may also be included as hydrocarbon monomers. Examples of non-crosslinkable hydrocarbon monomers include aromatic monovinyl monomers such as ethyl vinylbenzene.

[0127] The shape of the hollow resin particles used in this embodiment is not particularly limited as long as a hollow portion is formed inside, and examples include spherical, ellipsoidal, and irregular shapes. Among these, a spherical shape is preferred from the viewpoint of ease of manufacture and pressure resistance. The hollow resin particles used in this embodiment may have one or more hollow portions, but it is preferable that they have only one hollow portion in order to maintain a good balance between high porosity and mechanical strength, and to improve dielectric properties. In this embodiment, it is preferable that the proportion of particles having only one or two hollow portions is 90% by mass or more, and more preferably 95% by mass or more. Furthermore, it is preferable that the proportion of particles having only one hollow portion is 90% by mass or more, and more preferably 95% by mass or more.

[0128] Furthermore, the shell of the hollow resin particles used in this embodiment, and the partition walls separating adjacent hollow sections when there are two or more hollow sections, may be porous, but it is preferable that they be dense in order to improve dielectric properties. The hollow resin particles used in this embodiment may have an average circularity of 0.950 to 0.995. An example of the shape of the hollow resin particles used in this embodiment is a bag consisting of a thin film and inflated with gas, and its cross-sectional view is as shown for hollow resin particle 10 in Figure 1(5) of International Publication No. 2023 / 106307. In this example, a thin film is provided on the outside, and the inside is filled with gas. The particle shape can be confirmed, for example, by SEM.

[0129] The particle size distribution (volume average particle size (Dv) / number average particle size (Dn)) of the hollow resin particles may be, for example, 1.1 or more and 2.5 or less. By having a particle size distribution of 2.5 or less, particles with little variation in performance between particles can be obtained. Furthermore, by having a particle size distribution of 2.5 or less, for example, when manufacturing a sheet-like resin molded article to which the hollow resin particles used in this embodiment are added, a product with a uniform thickness can be manufactured. The lower limit of the particle size distribution (volume average particle size (Dv) / number average particle size (Dn)) of the hollow resin particles is practically 0.1 or more. The volume average particle size (Dv) and number average particle size (Dn) of the hollow resin particles can be determined, for example, by measuring the particle size of the hollow resin particles using a particle size distribution measuring device, calculating the number average and volume average, respectively, and using the obtained values ​​as the number average particle size (Dn) and volume average particle size (Dv) of those particles. The particle size distribution is the value obtained by dividing the volume average particle size by the number average particle size.

[0130] Furthermore, the hollow resin particles used in this embodiment also exhibit excellent dielectric properties due to the low proportion of particles with a circularity of 0.85 or less. Particles with a circularity of 0.85 or less are typically particles that have undergone deformation such as dents or cracks, and in this embodiment, they may be referred to as "irregularly shaped particles." Such irregularly shaped hollow resin particles have a lower porosity compared to spherical hollow resin particles, resulting in inferior dielectric properties. Therefore, reducing the proportion of irregularly shaped particles in the hollow resin particles can improve the dielectric properties of the hollow resin particles. In addition, irregularly shaped particles have a lower proportion of hollow space and a higher proportion of resin compared to spherical hollow resin particles, leading to a faster weight loss due to thermal decomposition and a lower thermal decomposition initiation temperature. Therefore, reducing the proportion of irregularly shaped particles in the hollow resin particles can improve the heat resistance of the hollow resin particles. Furthermore, irregularly shaped particles have the problem of being more prone to aggregation when dispersed in the matrix resin compared to spherical particles, resulting in poorer dispersibility. Furthermore, irregularly shaped particles have the problem of being less pressure-resistant than spherical particles because external pressure is more easily applied locally. When irregularly shaped particles are dispersed in a matrix resin, aggregates tend to form, and external pressure is easily applied to these aggregates, further reducing their pressure resistance. Therefore, by reducing the proportion of irregularly shaped particles contained in the hollow resin particles, the dispersibility and pressure resistance of the hollow resin particles can be improved. The hollow resin particles used in this embodiment may contain a small amount of particles with low circularity due to cracking or deformation as impurities, but the proportion of particles with a circularity of 0.85 or less in 100% by mass of the hollow resin particles used in this embodiment is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 5% by mass or less, even more preferably 4% by mass or less, and particularly preferably 3% by mass or less, with a lower limit of 0% by mass or more. Circularity is defined as the value obtained by dividing the diameter of a circle having the same area as the projection image of the particle (equivalent circle area diameter) by the diameter of a circle having the same perimeter as the projection image of the particle (equivalent perimeter circle diameter). The circularity is 1 when the particle is a perfect sphere, and the circularity decreases as the surface shape of the particle becomes more complex. In this embodiment, the circularity is measured using a flow-type particle image measuring device with an image resolution of 0.185 μm / pixel.As a flow-type particle image analyzer, for example, the "IF-3200" manufactured by JUSCO International Co., Ltd. can be preferably used. The measurement sample is prepared by dispersing a mixture of 0.10 to 0.12 g of hollow resin particles in an aqueous solution (concentration 0.3%) of linear alkylbenzene sulfonate in an ultrasonic cleaner for 5 minutes. The average circularity is the average value of the circularity of 1,000 to 3,000 arbitrarily selected particles.

[0131] In this embodiment, the thermal decomposition initiation temperature of the hollow resin particles is preferably 150 to 400°C, more preferably 335°C or higher, more preferably 340°C or higher, and even more preferably 345°C or higher. The thermal decomposition initiation temperature of the hollow resin particles may also be 370°C or lower, or 350°C or lower. The higher the thermal decomposition initiation temperature, the better the heat resistance of the hollow resin particles. In this embodiment, the thermal decomposition initiation temperature of the hollow resin particles is the temperature at which a 5% weight reduction occurs, and can be measured using a TG-DTA apparatus under an air atmosphere with an air flow rate of 230 mL / min and a heating rate of 10°C / min.

[0132] The method for producing hollow resin particles used in this embodiment can be based on the description in paragraphs 0019 to 0064 of International Publication No. 2023 / 106307, which is incorporated herein by reference.

[0133] In this embodiment, the content of hollow resin particles in the resin composition is preferably 0.1% by volume or more and less than 60% by volume of the filler. Setting it above the lower limit tends to lower the dielectric constant of the resulting cured product. Setting it below the upper limit tends to improve the heat resistance of the resulting cured product. The content of hollow resin particles in the filler is more preferably 5% by volume or more, even more preferably 10% by volume or more, even more preferably 40% by volume or less, and even more preferably 35% by volume or less. The resin composition of this embodiment may contain only one type of hollow resin particle, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0134] The content of hollow resin particles in the resin composition in this embodiment can be appropriately set according to the desired properties and is not particularly limited, but it is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and even more preferably 1.0 part by mass or more, per 100 parts by mass of resin solids in the resin composition. Setting it above the lower limit tends to result in better low thermal expansion and low dielectric loss tangent of the resulting cured product. The upper limit of the filler content is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, even more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. Setting it below the upper limit tends to result in better moldability of the resin composition. When the resin composition in this embodiment contains two or more types of hollow resin particles, it is preferable that the total amount is within the above range.

[0135] <<Other Fillers Other Than Hollow Resin Particles>> The types of other fillers used in this embodiment other than hollow resin particles are not particularly limited, and those commonly used in the industry can be suitably used. Specifically, silica such as natural silica, fused silica, synthetic silica, amorphous silica, Aerosil, and hollow silica; metal oxides such as alumina, white carbon, titanium white, titanium oxide, zinc oxide, magnesium oxide, and zirconium oxide; composite oxides such as zinc borate, zinc stannate, forsterite, barium titanate, strontium titanate, and calcium titanate; nitrides such as boron nitride, aggregated boron nitride, silicon nitride, and aluminum nitride; aluminum hydroxide; heat-treated aluminum hydroxide (aluminum hydroxide that has been heat-treated to reduce some of its crystal water); metal hydroxides (including hydrates) such as boehmite and magnesium hydroxide; acid Examples of inorganic fillers include molybdenum compounds such as molybdenum molasses and zinc molybdate, barium sulfate, clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, A-glass, NE-glass, NER-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, glass short fibers (including glass powders such as E-glass, T-glass, D-glass, S-glass, and Q-glass), hollow glass, and spherical glass, as well as organic fillers such as styrene-type, butadiene-type, and acrylic-type rubber powders, core-shell-type rubber powders, silicone resin powders, silicone rubber powders, and silicone composite powders. In this embodiment, inorganic fillers are preferred, and more preferably include one or more selected from the group consisting of silica other than hollow silica, aluminum hydroxide, talc, aluminum nitride, boron nitride, forsterite, titanium oxide, barium titanate, strontium titanate, and calcium titanate. From the viewpoint of low dielectric properties (Dk and / or Df), it is more preferable to include one or more selected from the group consisting of silica and aluminum hydroxide, and even more preferable to include silica. By using these inorganic fillers, the properties of the cured resin composition, such as heat resistance, dielectric properties, thermal expansion properties, dimensional stability, and flame retardancy, are further improved.

[0136] In the resin composition of this embodiment, when an inorganic filler is used, a silane coupling agent may be further included. Including a silane coupling agent tends to further improve the dispersibility of the filler and the adhesive strength between the resin component and the filler and glass substrate. Silane coupling agents are not particularly limited and generally include silane coupling agents used for surface treatment of inorganic materials, such as aminosilane compounds (e.g., γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, etc.), epoxysilane compounds (e.g., γ-glycidoxypropyltrimethoxysilane, etc.), vinylsilane compounds (e.g., vinyltrimethoxysilane, vinyltriethoxysilane, tetravinylsilane, triethylvinylsilane, 1,3-vinyltetramethylsiloxane, etc.), styrylsilane compounds (e.g., 4-vinylphenyltrimethoxysilane, etc.), acrylicsilane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), cationicsilane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), and phenylsilane compounds. Among these, it is preferable to include at least one selected from the group consisting of vinylsilane compounds, styrylsilane compounds, and acrylicsilane compounds, with vinylsilane compounds being more preferable. The silane coupling agent can be used alone or in combination of two or more. The content of the silane coupling agent is not particularly limited, but it is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and preferably 5.0 parts by mass or less, and more preferably 3.0 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. The silane coupling agent can be used alone or in combination of two or more. When two or more are used, the total amount will be within the above range.

[0137] The specific gravity of the filler other than the hollow resin particles used in this embodiment is preferably 1.5 or higher, more preferably 1.6 or higher, even more preferably 1.7 or higher, and also preferably 3.1 or lower, more preferably 2.6 or lower, and even more preferably 2.4 or lower. When the resin composition of this embodiment contains two or more types of fillers, it is preferable that the weighted average value falls within the above range.

[0138] The content of fillers (hollow resin particles and other fillers) in the resin composition in this embodiment can be appropriately set according to the desired properties and is not particularly limited, but is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. Setting it above the lower limit tends to result in better low thermal expansion and low dielectric loss tangent of the resulting cured product. The upper limit of the filler content is preferably 300 parts by mass or less, more preferably 200 parts by mass or less, even more preferably 100 parts by mass or less, even more preferably 80 parts by mass or less, and even more preferably 50 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. Setting it below the upper limit tends to result in better moldability of the resin composition. The resin composition in this embodiment may contain only one type of hollow resin particle or two or more types. The resin composition in this embodiment may contain only one type of filler other than hollow resin particles, or it may contain two or more types.

[0139] In the resin composition of this embodiment, as an example of the embodiment, there is an example in which the content of fillers (hollow resin particles and other fillers other than hollow resin particles) is 1 to 95% by mass of the components excluding the solvent, and an embodiment in which it is 10% to 60% by mass is preferred.

[0140] <Flame Retardant> The resin composition of this embodiment may contain a flame retardant. Examples of flame retardants include phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, and silicone-based flame retardants, with phosphorus-based flame retardants being preferred. Known flame retardants can be used, for example, halogen-based flame retardants such as brominated epoxy compounds, brominated polycarbonates, brominated polystyrene, brominated styrene, brominated phthalimide, tetrabromobisphenol A, pentabromobenzyl (meth)acrylate, pentabromotoluene, tribromophenol, hexabromobenzene, decabromodiphenyl ether, bis-1,2-pentabromopenyleethane, chlorinated polystyrene, and chlorinated paraffin, as well as red phosphorus, tricresyl phosphate, triphenyl phosphate, cresyldiphenyl phosphate, trixylenyl phosphate, trialkyl phosphate, and dialkyl phosphate. Examples of phosphorus-based flame retardants include tris(chloroethyl) phosphate, phosphazene, 1,3-phenylenebis(2,6-dixylenyl phosphate), 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, tris(2,6-diisopropyl-4-vinylphenyl) phosphate, tris(2,6-di-t-butyl-4-vinylphenyl) phosphate, phosphorus-based flame retardants such as phosphorus-based flame retardants Group A shown below, inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, partial boehmite, boehmite, zinc borate, antimony trioxide, and silicone-based flame retardants such as silicone rubber and silicone resin. <Phosphorus-based flame retardants Group A>

[0141] When the resin composition of this embodiment contains a flame retardant, its content is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. Setting the content above the lower limit tends to more effectively exhibit the flame retardancy of the resulting cured product. Furthermore, the lower limit of the flame retardant content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. Setting the content below the upper limit tends to more effectively suppress the deterioration of other physical properties. The flame retardant can be used alone or in combination of two or more types. When two or more types are used, the total amount will be within the above range.

[0142] <Activated Ester Compounds> The resin composition of this embodiment may contain activated ester compounds to the extent that they do not impair the effects of the present invention. The activated ester compounds are not particularly limited, and for example, the description in paragraphs 0064 to 0066 of International Publication No. 2021 / 172317 can be referenced, and this content is incorporated herein.

[0143] When the resin composition of this embodiment contains an active ester compound, it is preferable that the amount is 1 part by mass or more, and more preferably 50 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. The resin composition of this embodiment may contain only one type of active ester compound, or it may contain two or more types. When it contains two or more types, it is preferable that the total amount is within the above range. Furthermore, the resin composition of this embodiment may also be configured to be substantially free of active ester compounds. Substantially free means that the content of the active ester compound is less than 1 part by mass, preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass, per 100 parts by mass of resin solids in the resin composition.

[0144] <Aromatic Vinyl Compounds and Aromatic Oligomers> The resin composition of this embodiment may contain aromatic vinyl compounds and / or aromatic oligomers, and more preferably contains aromatic vinyl compounds. Examples of aromatic vinyl compounds include styrene, α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 4-propylstyrene, 4-t-butylstyrene, 4-cyclohexylstyrene, 4-dodecylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 2,4,6-trimethylstyrene, 2-ethyl-4-benzylstyrene, 4-(phenylbutyl)styrene, 1-vinylnaphthalene, 2-vinylnaphthalene, vinylanthracene, N,N-diethyl-4-aminoethylstyrene, vinylpyridine, 4-methoxystyrene, monochlorostyrene, dichlorostyrene, orthodivinylbenzene, metadivinylbenzene, paradivinylbenzene, and the like. These aromatic vinyl compounds may be used individually or in combination of two or more. Among these, styrene, α-methylstyrene, 4-methylstyrene, orthodivinylbenzene, metadivinylbenzene, and paradivinylbenzene are preferred, with 4-methylstyrene and orthodivinylbenzene being more preferred.

[0145] Aromatic oligomers are oligomers having structural units derived from aromatic vinyl compounds, and typically refer to compounds with a weight-average molecular weight of less than 3000. Aromatic oligomers are also typically thermoplastic oligomers. In this embodiment, aromatic oligomers do not include polymers having structural units represented by formula (V), styrene elastomers, or any of the compounds explicitly mentioned in any of the above sections.

[0146] Aromatic oligomers may contain constituent units derived from monomers other than aromatic vinyl compounds. Examples of such other monomers include (meth)acrylic acid, (meth)acrylic acid derivatives, (meth)acrylamide, (meth)acrylamide derivatives, (meth)acrylonitrile, isoprene, 1,3-butadiene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, N-vinylindole, N-vinylphthalimide, N-vinylpyrrolidone, N-vinylcarbazole, and N-vinylcaprolactam.

[0147] The content of constituent units derived from aromatic vinyl compounds in the aromatic oligomer is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0148] The weight-average molecular weight (Mw) of the aromatic oligomer is preferably 300 or more, more preferably 500 or more, even more preferably 1,000 or more, and usually less than 3,000, preferably 2,800 or less, more preferably 2,500 or less, and may also be 2,000 or less. The weight-average molecular weight (Mw) of the aromatic oligomer is the value obtained on a standard polystyrene basis by gel permeation chromatography.

[0149] Examples of aromatic oligomers include polystyrene, poly-α-methylstyrene, poly-4-methylstyrene, styrene / α-methylstyrene copolymer, styrene / 4-methylstyrene copolymer, α-methylstyrene / 4-methylstyrene copolymer, and styrene / α-methylstyrene / 4-methylstyrene copolymer. Aromatic oligomers may be used individually or in combination of two or more.

[0150] Commercially available aromatic oligomers may be used. Examples of commercially available aromatic oligomers include Picolastic A5 (polystyrene, softening point 5°C, Mw 350), Picolastic A-75 (polystyrene, softening point 74°C, Mw 1300), Picotex 75 (α-methylstyrene / 4-methylstyrene copolymer, softening point 75°C, Mw 1100), Picotex LC (α-methylstyrene / 4-methylstyrene copolymer, softening point 91°C, Mw 1350), and Crystallet. Aromatic polymers manufactured by Eastman, such as KUSU 3070 (styrene / α-methylstyrene copolymer, softening point 70°C, Mw 950), CRYSTAREX 3085 (styrene / α-methylstyrene copolymer, softening point 85°C, Mw 1150), and CRYSTAREX 3100 (styrene / α-methylstyrene copolymer, softening point 100°C, Mw 1500), and YS Resin SX-100 (polystyrene, softening point 100°C, Mw 2500). FMR-0150 (styrene / aromatic hydrocarbon copolymer, softening point 145°C, Mw 2040; manufactured by Mitsui Chemicals, Inc.), FTR-6100 (styrene / aliphatic hydrocarbon copolymer, softening point 95°C, Mw 1210; manufactured by Mitsui Chemicals, Inc.), FTR-6110 (styrene / aliphatic hydrocarbon copolymer, softening point 110°C, Mw 1570; manufactured by Mitsui Chemicals, Inc.), FTR-6125 (styrene / aliphatic hydrocarbon copolymer) Examples include poly(α-methylstyrene), softening point 125°C, Mw 1950; manufactured by Mitsui Chemicals, Inc., FTR-7100 (styrene / α-methylstyrene / aliphatic hydrocarbon copolymer, softening point 100°C, Mw 1440; manufactured by Mitsui Chemicals, Inc.), FTR-0100 (poly(α-methylstyrene), softening point 100°C, Mw 1960; manufactured by Mitsui Chemicals, Inc.), FTR-2120 (styrene / α-methylstyrene copolymer, softening point 120°C, Mw 2630; manufactured by Mitsui Chemicals, Inc.). In addition to the above, details of aromatic oligomers can also be found in paragraphs 0069-0087 of International Publication No. 2017 / 135168, where the equivalents for aromatic oligomers are used, and this content is incorporated herein by reference.

[0151] When the resin composition of this embodiment contains an aromatic vinyl compound and / or an aromatic oligomer, the total content is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and may be 4 parts by mass or more, per 100 parts by mass of resin solids. Setting it above the lower limit tends to lower the dielectric constant and dielectric loss tangent. Furthermore, the upper limit of the total content of the aromatic vinyl compound and / or aromatic oligomer is preferably 45 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and may be 10 parts by mass or less, per 100 parts by mass of resin solids. Setting it below the upper limit tends to improve chemical resistance. The resin composition of this embodiment may contain only one type of aromatic vinyl compound and / or aromatic oligomer, or it may contain two or more types. When containing two or more types, it is preferable that the total amount is within the above range.

[0152] <Silane Coupling Agent> The resin composition of this embodiment may further contain a silane coupling agent. The resin composition of this embodiment tends to have improved dispersibility of the filler by containing a silane coupling agent.

[0153] The silane coupling agent is not particularly limited and generally refers to silane coupling agents used for surface treatment of inorganic materials. Examples include aminosilane compounds (e.g., γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, etc.), epoxysilane compounds (e.g., γ-glycidoxypropyltrimethoxysilane, etc.), acrylicsilane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), cationic silane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), vinylsilane compounds (e.g., vinyltrimethoxysilane, etc.), styrylsilane compounds (e.g., styryltrimethoxysilane, etc.), and phenylsilane compounds (e.g., phenyltrimethoxysilane, etc.). The silane coupling agent may be used alone or in combination of two or more. Among these, the silane coupling agent is preferably an epoxysilane compound. Examples of epoxysilane compounds include "KBM-403," "KBM-303," "KBM-402," "KBE-403," and "KBM-1003," all products of Shin-Etsu Chemical Co., Ltd.

[0154] When the resin composition of this embodiment contains a silane coupling agent, its content is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1.0 part by mass or more, preferably 10 parts by mass or less, more preferably 7 parts by mass or less, even more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less, based on 100 parts by mass of resin solids. Setting the content above the lower limit tends to improve heat resistance. Setting the content below the upper limit tends to further reduce the dielectric constant and dielectric loss tangent. The resin composition of this embodiment may contain only one type of silane coupling agent, or it may contain two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0155] <Dispersant> The resin composition of this embodiment may contain a dispersant. Suitable dispersants are those commonly used for paints, and the type is not particularly limited. Preferably, a copolymer-based wetting dispersant is used, and specific examples include DISPERBYK®-110, 111, 161, 180, 2009, 2152, 2155, BYK®-W996, W9010, W903, and W940, all manufactured by BIC Chemie Japan Co., Ltd.

[0156] If the resin composition of this embodiment contains a dispersant, the lower limit of its content is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and may also be 0.3 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and may also be 3 parts by mass or less, based on 100 parts by mass of resin solids in the resin composition. The dispersant can be used alone or in combination of two or more types. When two or more types are used, the total amount will be within the above range.

[0157] <Curing Accelerator> The resin composition in this embodiment may further contain a curing accelerator. The curing accelerator is not particularly limited, but examples include imidazoles such as 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, and triphenylimidazole; benzoyl peroxide, organic peroxides; azo compounds such as azobisnitrile (e.g., azobisisobutyronitrile) and 2,2-azobis(2,4,4-trimethylpentane); and N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2-N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, N-methylmorpholine, triethanolamine, triethylenediamine, tetramethylbutanediamine, and N-methylpiperidine. Examples include tertiary amines; phenols such as phenol, xylenol, cresol, resorcinol, and catechol; high-temperature decomposition radical generators such as 2,3-dimethyl-2,3-diphenylbutane; organometallic salts such as lead naphthenate, lead stearate, zinc naphthenate, zinc octoate, manganese octoate, tin oleate, dibutyltin maleate, manganese naphthenate, cobalt naphthenate, and iron acetylacetone; compounds obtained by dissolving these organometallic salts in hydroxyl group-containing compounds such as phenol and bisphenol; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; and organotin compounds such as dioctyl tin oxide, other alkyltins, and alkyltin oxides.

[0158] Examples of organic peroxides include diacyl peroxides, peroxydicarbonates, peroxyesters, peroxyketals, dialkyl peroxides, and hydroperoxides.

[0159] Examples of diacyl peroxides include diisobutyryl peroxide, di(3,5,5-trimethylhexanoyl) peroxide, dilauroyl peroxide, disuccinate peroxide, di-(3-methylbenzoyl) peroxide, benzoyl(3-methylbenzoyl) peroxide, and dibenzoyl peroxide.

[0160] Examples of peroxycarbonates include di-n-propyl peroxydicarbonate, diisopropyl peroxydicarbonate, di(4-tert-butylcyclohexyl) peroxydicarbonate, di(2-ethylhexyl) peroxydicarbonate, and di-sec-butyl peroxydicarbonate.

[0161] Examples of peroxyesters include cumyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert-hexyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-hexyl peroxypivalate, tert-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, tert-hexyl peroxy-2-ethylhexanoate, and tert-butyl peroxy-2-ethylhexanoate. Examples include xanoates, tert-hexyl peroxyisopropyl monocarbonate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl monocarbonate, tert-butyl peroxy-2-ethylhexyl monocarbonate, tert-hexyl peroxybenzoate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, tert-butyl peroxyacetate, tert-butyl peroxy-3-methylbenzoate, and tert-butyl peroxybenzoate.

[0162] Examples of peroxyketals include 1,1-di(tert-hexylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,2-di(tert-butylperoxy)butane, n-butyl-4,4-di-(tert-butylperoxy)valerate, and 2,2-di(4,4-di-(tert-butylperoxy)cyclohexyl)propane.

[0163] Examples of dialkylperoxides include di(2-tert-butylperoxyisopropyl)benzene, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, tert-butylcumyl peroxide, di-tert-hexyl peroxide, di-tert-butyl peroxide, di-tert-amyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hexyne-3.

[0164] Examples of hydroperoxides include p-menthane hydroperoxide, diisopropylbenzene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, cumene hydroperoxide, tert-butyl hydroperoxide, and tert-amyl hydroperoxide.

[0165] In particular, preferred curing accelerators are at least one selected from the group consisting of imidazoles, organometallic salts, and organic peroxides, with at least one selected from the group consisting of organometallic salts and organic peroxides being more preferred, and organic peroxides being even more preferred. By using organic peroxides, the reaction between the maleimide compound and the hollow resin particles proceeds appropriately, and the crosslinking density tends to improve, thereby further promoting a higher glass transition temperature and higher rigidity.

[0166] If the resin composition in this embodiment contains a curing accelerator, the lower limit of its content is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, even more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. The upper limit of the curing accelerator content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 2 parts by mass or less, even more preferably 1.0 part by mass or less, even more preferably 0.8 parts by mass or less, and even more preferably 0.6 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. The resin composition in this embodiment is preferable in that it can sufficiently cure the resin composition even if the curing accelerator content is below the above upper limit. The curing accelerator can be used alone or in combination of two or more types. When two or more types are used, the total amount will be within the above range.

[0167] <Solvent> The resin composition of this embodiment may contain a solvent, and preferably an organic solvent. When a solvent is included, the resin composition of this embodiment is in a form (solution or varnish) in which at least a portion, preferably all, of the above-mentioned resin solids are dissolved or miscible with the solvent. The solvent is not particularly limited as long as it is a polar or nonpolar organic solvent capable of dissolving or miscible with at least a portion, preferably all, of the above-mentioned resin solids. Examples of polar organic solvents include ketones (e.g., acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 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, isoamyl acetate, ethyl lactate, methyl methoxypropionate, methyl hydroxyisobutyrate, etc.), and amides (e.g., dimethoxyacetamide, dimethylformamide, etc.). Examples of nonpolar organic solvents include aromatic hydrocarbons (e.g., toluene, xylene, etc.). The solvent can be used individually or in combination of two or more types. When using two or more types, the total amount must be within the above range.

[0168] <Other Components> The resin composition in this embodiment may contain various polymer compounds (such as petroleum resins) other than the components listed above, such as thermoplastic resins and their oligomers, and various additives. Examples of additives include at least one selected from the group consisting of ultraviolet absorbers, antioxidants, curing accelerators (excluding those corresponding to radical polymerization initiators), fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, flow regulators, lubricants, defoamers, leveling agents, gloss agents, and polymerization inhibitors. The content (total amount) of various polymer compounds other than the components listed above in the resin composition in this embodiment is preferably 0 parts by mass or more and less than 10 parts by mass, more preferably 0 parts by mass or more and less than 5 parts by mass, even more preferably 0 parts by mass or more and less than 3 parts by mass, and may be 0 parts by mass or more and less than 1 part by mass, per 100 parts by mass of resin solids. The total amount of the additive is preferably 0 parts by mass or more and less than 5 parts by mass, more preferably 0 parts by mass or more and less than 3 parts by mass, even more preferably 0 parts by mass or more and less than 1 part by mass, and may be 0 parts by mass or more and less than 0.5 parts by mass, per 100 parts by mass of resin solids.

[0169] <Applications> The resin composition of this embodiment is used as a cured product. The resin composition of this embodiment is typically used as a thermosetting resin composition that hardens with heat. Specifically, the resin composition of this embodiment can be suitably used as a low dielectric constant material and / or a low dielectric loss tangent material, as a resin composition for electronic materials such as insulating layers for printed circuit boards and materials for semiconductor packages. The resin composition of this embodiment is preferably used as a resin film or a resin composite sheet. It can also be suitably used as a material for prepregs, metal foil laminates, and printed circuit boards. In particular, the resin composition of this embodiment is preferably used as a resin composite sheet that does not contain a base material such as glass cloth. In prepregs, glass cloth acts as a base material to maintain toughness, but in resin films without glass cloth, toughness tends to decrease. Such a decrease in toughness has been a concern due to the deterioration of transportability before hardening and the deterioration of crack resistance after hardening. The resin composition of this embodiment is extremely beneficial in that it can avoid these problems.

[0170] The resin composition of this embodiment preferably has a low relative permittivity (Dk) and dielectric loss tangent (Df) in its cured product. More specifically, for a sample of the resin composition molded to a thickness of 0.8 mm and a size of 1 mm x 100 mm, the dielectric loss tangent (Df) at a frequency of 10 GHz, measured by the cavity resonator perturbation method in accordance with JIS C2138:2007, is preferably less than 0.003, and more preferably less than 0.002. There is no particular lower limit for the dielectric loss tangent (Df), but for example, 0.0001 or higher is practical. Furthermore, for the sample, the relative permittivity (Dk) at a frequency of 10 GHz, measured by the cavity resonator perturbation method in accordance with JIS C218:2007, is preferably 2.90 or less, and more preferably 2.87 or less. There is no particular lower limit for the relative permittivity (Dk), but for example, 0.01 or higher is practical. The dielectric loss tangent (Df) and relative permittivity (Dk) of the above-mentioned cured product are measured by the method described in the examples below.

[0171] The resin composition of this embodiment preferably has a low coefficient of thermal expansion. Specifically, when the resin composition of this embodiment is molded to a thickness of 0.8 mm, the coefficient of thermal expansion (Z-CTE) measured according to JIS C 6481 5.19 is preferably 130 ppm / °C or less, and more preferably 100 ppm / °C or less. There is no particular lower limit for the coefficient of thermal expansion, but 80 ppm / °C or more is practical.

[0172] <<Resin Film>> The resin film of this embodiment is formed from the resin film of this embodiment. The thickness of the film of this embodiment is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, and also preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and may be 50 μm or less. Setting the thickness above the lower limit tends to further improve handling properties. Setting the thickness below the upper limit tends to further improve the effect of suppressing peeling of the resin film from other components.

[0173] The method for manufacturing the resin film is not particularly limited, but one example is to apply (coat) a solution obtained by dissolving the resin composition of this embodiment in a solvent onto a support and then drying it to obtain a resin film. As for the application method (coating method), for example, the solution obtained by dissolving the resin composition of this embodiment in a solvent is applied onto the support using a bar coater, die coater, doctor blade, baker applicator, etc. Alternatively, after drying, the support can be peeled off or etched from the multilayer body formed by laminating the support and the resin composition to obtain a resin film. Furthermore, a resin film can also be obtained without using a support by supplying a solution obtained by dissolving the resin composition of this embodiment in a solvent into a mold having a sheet-like cavity and drying it to form a film.

[0174] In the production of the resin film according to this embodiment, the drying conditions for removing the solvent are not particularly limited, but since solvent tends to remain in the resin composition at low temperatures and the resin composition hardens at high temperatures, a temperature of 20°C to 200°C for 1 to 90 minutes is preferred. The resin film can be used in an uncured state after the solvent has been dried, or it can be used in a semi-cured (B-stage) state as needed. The thickness of the resin film can be adjusted by the concentration of the solution of the resin composition according to this embodiment used for coating and the coating thickness.

[0175] The resin film of this embodiment typically does not contain a substrate. The substrate referred to here is exemplified by the substrates shown in the prepreg section described later, and glass cloth is preferred. Such resin films that do not contain a substrate such as glass cloth are preferably used as thin-film build-up materials.

[0176] <<Resin Composite Sheet>> The resin composite sheet of this embodiment has a film comprising a support and a layer formed from the resin composition of this embodiment disposed on the surface of the support. The resin composite sheet of this embodiment usually does not contain a substrate. The substrate here is exemplified by the substrate shown in the prepreg section described later, and glass cloth is preferred. The resin composite sheet of this embodiment can be used as a build-up film.

[0177] Examples of the support include metal foils such as copper foil, thermoplastic resin films such as polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, and ethylene tetrafluoroethylene copolymer film, as well as release films obtained by applying a release agent to the surface of the thermoplastic resin film, organic film substrates such as polyimide film, glass plates, SUS (Steel Use Stainless) plates, and FRP (Fiber-Reinforced Plastics). Metal foil or thermoplastic resin film is preferred, and copper foil or polyethylene terephthalate film is more preferred. As for copper foil, for example, a peelable type can be used. Peelable copper foil is an ultrathin copper foil having a release layer, where the release layer is, for example, a copper foil that can be peeled off. When using peelable copper foil, the copper foil is laminated so that the release layer is in contact with a resin film formed from a resin composition. Examples of the defacement layer include a layer containing at least a silicon compound, which can be formed, for example, by applying a silicon compound consisting of one or more silane compounds onto a copper foil or ultrathin copper foil. The means of applying the silicon compound are not particularly limited, and known means such as coating can be used. The adhesion surface of the copper foil to the defacement layer can be treated with a rust-preventive treatment (forming a rust-preventive treatment layer). The rust-preventive treatment can be performed using nickel, tin, zinc, chromium, molybdenum, cobalt, or an alloy thereof.

[0178] The thickness of the demolition layer is not particularly limited, but from the viewpoint of ease of removal and peelability, it is preferably 5 nm or more, more preferably 10 nm or more, even more preferably 20 nm or more, and also preferably 100 nm or less, more preferably 80 nm or less, and even more preferably 60 nm or less.

[0179] Another example of copper foil is an ultra-thin copper foil with a carrier. In this case, it is preferable that the copper foil is arranged in contact with a resin film formed from a resin composition, and the carrier is peeled off after the laminate is formed by heating and pressing.

[0180] A first example of the resin composite sheet of this embodiment is a resin composite sheet in which a thermoplastic resin film (preferably polyethylene terephthalate film) is provided on one side of a resin film formed from the resin composition of this embodiment, and a metal foil (preferably copper foil) is provided on the other side. A second example of the composite resin sheet of this embodiment is a resin composite sheet in which a thermoplastic resin film (preferably polyethylene terephthalate film) is provided on both sides of a resin film formed from the resin composition of this embodiment.

[0181] A third example of the resin composite sheet of this embodiment is a resin composite sheet in which metal foil (preferably copper foil) is provided on both sides of a resin film formed from the resin composition of this embodiment. In the third example of the resin composite sheet, one side of the resin film is a peelable type copper foil, and the other side is an ultra-thin copper foil with a carrier.

[0182] The thickness of the metal foil is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, preferably 200 μm or less, more preferably 100 μm or less, even more preferably 20 μm or less, even more preferably 12 μm or less, and even more preferably 5 μm or less. Setting the thickness above the lower limit tends to improve handling performance. Setting the thickness below the upper limit tends to improve the effect of suppressing peeling of the resin film from other components.

[0183] The thickness of the thermoplastic resin film is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and may be 50 μm or less. Setting the thickness above the lower limit tends to further improve handling properties. Setting the thickness below the upper limit tends to further improve the effect of suppressing peeling of the resin film from other components.

[0184] The thickness of the resin composite sheet is preferably 5 μm or more, more preferably 8 μm or more, even more preferably 10 μm or more, preferably 200 μm or less, more preferably 150 μm or less, even more preferably 100 μm or less, and may be 50 μm or less. Setting the thickness above the lower limit tends to further improve handling properties. Setting the thickness below the upper limit tends to further improve the effect of suppressing peeling of the resin film from other components.

[0185] Details of the resin composite sheet and the method for manufacturing the same can be found, for example, in paragraphs 0037 to 0067 of Japanese Patent No. 7583362, which are incorporated herein by reference.

[0186] <<Prepreg>> The resin composition of this embodiment can also be used to make a prepreg. The prepreg of this embodiment is formed from a substrate (prepreg substrate) and the resin composition of this embodiment. The prepreg of this embodiment can be obtained, for example, by applying the resin composition of this embodiment to the substrate (e.g., impregnation and / or coating), and then partially curing it by heating (e.g., drying at 120 to 220°C for 2 to 15 minutes). In this case, the amount of resin composition adhering to the substrate, i.e., the amount of resin composition (including hollow silica and filler) relative to the total amount of prepreg after partial curing, is preferably in the range of 20 to 99% by mass, and more preferably in the range of 20 to 80% by mass.

[0187] The substrate is not particularly limited as long as it is a substrate used in various printed circuit board materials. Examples of substrate materials include glass fibers (e.g., E-glass, D-glass, L-glass, S-glass, T-glass, Q-glass, UN-glass, NE-glass, NER-glass, spherical glass, etc.), inorganic fibers other than glass (e.g., quartz, etc.), and organic fibers (e.g., polyimide, polyamide, polyester, liquid crystal polyester, polytetrafluoroethylene, etc.). The form of the substrate is not particularly limited and includes woven fabrics, nonwoven fabrics, rovings, chopped strand mats, and surfacing mats. These substrates may be used individually or in combination of two or more. Among these substrates, woven fabrics that have undergone ultra-opening treatment and densification treatment are preferred from the viewpoint of dimensional stability, and from the viewpoint of strength and low water absorption, the substrate should have a thickness of 200 μm or less and a mass of 250 g / m². ２ The following glass woven fabrics are preferred, and from the viewpoint of moisture absorption and heat resistance, glass woven fabrics surface-treated with silane coupling agents such as epoxysilane and aminosilane are preferred. From the viewpoint of electrical properties, low dielectric glass cloths made of glass fibers exhibiting low dielectric constant and low dielectric loss tangent, such as L-glass, NE-glass, NER-glass, and Q-glass, are more preferred. Examples of low dielectric constant substrates include substrates with a dielectric constant of 5.0 or less (preferably 3.0 to 4.9). Examples of low dielectric loss tangent substrates include substrates with a dielectric loss tangent of 0.006 or less (preferably 0.001 to 0.005). The dielectric constant and dielectric loss tangent are values ​​measured at a frequency of 10 GHz using a perturbation cavity resonator.

[0188] <<Metal Foil Clad Laminate>> The resin composition of this embodiment may also be used in a metal foil clad laminate. The metal foil clad laminate comprises the prepreg of this embodiment and metal foil disposed on one or both sides of the prepreg. For details of the metal foil clad laminate and its manufacturing method, refer to paragraphs 0142-0144 of International Publication No. 2024 / 225152, which are incorporated herein by reference.

[0189] <<Printed Wiring Board>> The printed wiring board of this embodiment includes an insulating layer and a conductive layer disposed on the surface of the insulating layer, wherein the insulating layer includes a layer formed from the resin composition of this embodiment. Such a printed wiring board can be manufactured according to conventional methods, and the method of manufacture is not particularly limited. Details of the printed wiring board can be found in paragraphs 0146-0148 of International Publication No. 2024 / 225152, the contents of which are incorporated herein.

[0190] <<Semiconductor Device>> This embodiment also relates to a semiconductor device including the printed circuit board. Details of the semiconductor device can be found in paragraphs 0200 to 0202 of Japanese Patent Application Publication No. 2021-021027, the contents of which are incorporated herein by reference.

[0191] The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, processing content, processing procedures, etc., shown in the following examples can be modified as appropriate, as long as they do not depart from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. If the measuring instruments, etc., used in the examples are difficult to obtain due to discontinuation or other reasons, measurements can be taken using other instruments with equivalent performance.

[0192] <Measurement of Weight-Average and Number-Average Molecular Weight> The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of compounds (including resins) were measured by gel permeation chromatography (GPC). A liquid delivery pump (Shimadzu Corporation, LC-20AD), a differential refractive index detector (Shimadzu Corporation, RID-20A), and GPC columns (Showa Denko Corporation, GPC KF-801, 802, 803, 804) were used. Tetrahydrofuran was used as the solvent, and the flow rate was 1.0 mL / min at a column temperature of 40°C. A calibration curve using monodisperse polystyrene was prepared and used.

[0193] <Synthesis Example 1: Synthesis of a polyphenylene ether compound (D1) having a carbon-carbon unsaturated double bond at the terminal> <<Synthesis of a bifunctional phenylene ether oligomer>> CuBr was used in a vertical reactor equipped with a stirring device, thermometer, air inlet tube and baffle plate. ２0.33 g (1.5 mmol) of copper bromide, 0.63 g (3.7 mmol) of N,N'-di-t-butylethylenediamine, 6.95 g (69 mmol) of n-butyldimethylamine, 670 g of toluene, and 320 g of methanol were charged and stirred at a reaction temperature of 40°C until dissolved. In addition, 46.2 g (171 mmol) of 2,2',3,3',5,5'-hexamethyl-(1,1'-biphenyl)-4,4'-diol, 129.5 g (1,060 mmol) of 2,6-dimethylphenol, and CuBr were added in a separate container. ２ 0.33 g (1.5 mmol) of copper bromide, 0.63 g (3.7 mmol) of N,N'-di-t-butylethylenediamine, 6.95 g (69 mmol) of n-butyldimethylamine, 440 g of toluene, and 170 g of methanol were charged and stirred at a reaction temperature of 40°C to dissolve. Then, while bubbling a mixed gas of nitrogen and air adjusted to an oxygen concentration of 8% into the mixture in the polymerization tank, the mixture from the dropping tank was added dropwise over 280 minutes and stirred. After the dropwise addition was complete, 700 g of water in which 7.1 g (16 mmol) of tetrasodium ethylenediaminetetraacetate was dissolved was added to stop the reaction. The aqueous layer and the organic layer were separated, and the organic layer was washed with a 1 M aqueous hydrochloric acid solution, and then with pure water. The obtained solution was concentrated to 50% by mass using an evaporator to obtain 340 g of toluene solution A of phenylene ether resin. The number-average molecular weight in polystyrene equivalents, calculated using the GPC method, was 985. The weight-average molecular weight in polystyrene equivalents, calculated using the GPC method, was 1090, and the hydroxyl group equivalent was 478 g / eq.

[0194] <<Synthesis of Modified Polyphenylene Ether Compound>> In a reactor equipped with a stirrer, thermometer, and reflux tubing, 300 g of toluene solution A of the phenylene ether resin obtained above, 57.5 g (0.38 mol) of vinyl benzyl chloride (AGC Seimi Chemical Co., Ltd., "CMS-P"), 1200 g of methylene chloride, 5 g (0.037 mol) of benzyldimethylamine, 70 g of pure water, and 63 g of 30.5% by mass NaOH aqueous solution were charged, and the mixture was stirred at a reaction temperature of 40°C. After stirring for 24 hours, the organic layer was washed with 1 M hydrochloric acid aqueous solution, and then with pure water. The obtained solution was concentrated and added dropwise to methanol to solidify it, and the solid was recovered by filtration and vacuum dried to obtain 178 g of polyphenylene ether compound (D1) mainly composed of the compound represented by formula (OP-15). The number-average molecular weight in polystyrene terms, calculated by GPC, was 1200, the weight-average molecular weight in polystyrene terms, calculated by GPC, was 1840, the double bond equivalent of the vinyl group was 620 g / eq., and the hydroxyl group equivalent was 48500 g / eq.

[0195] <Synthesis Example 2: Synthesis of Polymer (va) Having Constituent Units Represented by Formula (V)> 2.25 moles (292.9 g) of divinylbenzene, 1.32 moles (172.0 g) of ethylvinylbenzene, 11.43 moles (1190.3 g) of styrene, and 15.0 moles (1532.0 g) of n-propyl acetate were placed in a reactor. 600 mmol of a diethyl ether complex of boron trifluoride was added at 70°C, and the reaction was allowed to proceed for 4 hours. After stopping the polymerization reaction with an aqueous sodium bicarbonate solution, the oil layer was washed three times with pure water, and defoliation was performed under reduced pressure at 60°C to recover the polymer (va) having constituent units represented by formula (V). The obtained polymer (va) having constituent units represented by formula (V) was weighed to confirm that 860.8 g of polymer (va) having constituent units represented by formula (V) was obtained.

[0196] The polymer (va) having the constituent units represented by the obtained formula (V) had a number-average molecular weight Mn of 2,060, a weight-average molecular weight Mw of 30,700, and a monodispersity degree Mw / Mn of 14.9. １３ C-NMR and １By performing 1H-NMR analysis, resonance lines originating from each monomer unit used as a raw material were observed in the polymer (va) having the constituent units represented by formula (V). Based on the NMR measurement results and GC analysis results, the proportion of each monomer unit (constituent units derived from each raw material) in the polymer (va) having the constituent units represented by formula (V) was calculated as follows: Constituent units derived from divinylbenzene: 20.9 mol% (24.3 mass%) Constituent units derived from ethylvinylbenzene: 9.1 mol% (10.7 mass%) Constituent units derived from styrene: 70.0 mol% (65.0 mass%) In addition, the constituent units with residual vinyl groups derived from divinylbenzene amounted to 16.7 mol% (18.5 mass%). The vinyl group equivalent was 241 g / eq.

[0197] <Synthesis Example 3: Synthesis of Hollow Resin Particles> Hollow resin particles were obtained according to the description in Example 1 of International Publication No. 2023 / 106307. Specifically, the following method was used.

[0198] (1) Preparation of mixed solution First, the following materials were mixed to form the oil phase: Divinylbenzene 37.5 parts by mass Ethyl vinylbenzene 1.6 parts by mass t-Butyl peroxydiethyl acetate (10-hour half-life temperature: 75°C) 0.89 parts by mass Hydrophobic solvent: Heptane (solubility in water at 20°C: 2.2 mg / L, boiling point 98.4°C) 60.8 parts by mass Next, in a stirring tank, an aqueous solution prepared by dissolving 15.7 parts by mass of magnesium chloride (water-soluble polyvalent metal salt) in 225 parts by mass of ion-exchanged water was gradually added under stirring to an aqueous solution prepared by dissolving 11.0 parts by mass of sodium hydroxide (alkali metal hydroxide) in 55 parts by mass of ion-exchanged water to prepare a magnesium hydroxide colloid (poorly water-soluble metal hydroxide colloid) dispersion (8 parts by mass of magnesium hydroxide), which was used as the aqueous phase. The obtained aqueous phase and oil phase were mixed to prepare the mixed solution. The proportion of hydrocarbon monomers to total monomers is 100% by mass, and the proportion of crosslinkable monomers is 96% by mass.

[0199] (2) Suspension step: The mixed solution obtained in the above-mentioned mixed solution preparation step is stirred for 1 minute under the condition of a rotation speed of 4,000 rpm using an emulsifying disperser (manufactured by Primix Corporation, product name: Homomixer), thereby performing a suspension treatment to prepare a suspension in which droplets of a monomer composition encapsulating a hydrophobic solvent are dispersed in water.

[0200] (3) Polymerization step: The suspension obtained in the above-mentioned suspension step is heated to 80°C under a nitrogen atmosphere, and stirred for 24 hours under the temperature condition of 80°C to carry out a polymerization reaction. Through this polymerization reaction, a precursor composition which is a slurry liquid of precursor particles encapsulating a hydrophobic solvent dispersed in water is obtained.

[0201] (4) Washing step and solid-liquid separation step: The precursor composition obtained in the above-mentioned polymerization step is washed with dilute sulfuric acid (at 25°C for 10 minutes) to adjust the pH to 5.5 or lower. Then, after water is separated by filtration, 200 parts by mass of new ion-exchanged water is added to reslurry, and a water washing treatment (washing, filtration, dehydration) is repeated several times at room temperature (25°C), followed by filtration separation to obtain a solid content. The obtained solid content is dried at 40°C in a dryer to obtain precursor particles encapsulating a hydrophobic solvent.

[0202] (5) Solvent removal step: The precursor particles obtained in the above-mentioned solid-liquid separation step are heat-treated in a vacuum dryer under vacuum conditions of 200°C for 12 hours to remove the hydrophobic solvent encapsulated in the particles, thereby obtaining the hollow resin particles of Synthesis Example 1. It was confirmed from the observation results of a scanning electron microscope and the porosity value that the obtained hollow resin particles are spherical and have a hollow portion.

[0203] <<Density and Porosity of Hollow Resin Particles>> A volumetric flask with a capacity of 100 cm ３ is filled with approximately 30 cm ３ of hollow resin particles, and the mass of the filled hollow resin particles is accurately weighed. Next, isopropyl alcohol is accurately filled up to the mark while taking care not to allow air bubbles to enter the volumetric flask filled with hollow resin particles. The mass of isopropyl alcohol added to the volumetric flask is accurately weighed, and the apparent density D １ (g / cm ３ ) of the hollow resin particles is calculated based on the above formula (I). Formula (I) Apparent density D １= [mass of hollow resin particles] / (100 - [mass of isopropanol] / [specific gravity of isopropanol at measurement temperature])

[0204] After pulverizing the hollow resin particles in advance, the hollow resin particles are placed in a volumetric flask with a volume of 100 cm ３ was filled with approximately 10 g of pulverized pieces of hollow resin particles, and the mass of the filled pulverized pieces was accurately weighed. Thereafter, isopropanol was added to the volumetric flask in the same manner as in the measurement of the apparent density described above, the mass of isopropanol was accurately weighed, and based on the following formula (II), the true density D of the hollow resin particles ０ (g / cm ３ ) was calculated. Formula (II) True density D ０ = [mass of pulverized pieces of hollow resin particles] / (100 - [mass of isopropanol] / [specific gravity of isopropanol at measurement temperature])

[0205] From the apparent density D of the hollow resin particles １ and the true density D ０ , the porosity of the hollow resin particles was calculated based on the following formula (III). Formula (III) Porosity (%) = 100 - (apparent density D １ / true density D ０ ) × 100 The Dv of the hollow resin particles obtained in Synthesis Example 3 was 4.1 µm, Dv / Dn was 1.4, and the porosity was 70%.

[0206] The volume average particle diameter (Dv) and number average particle diameter (Dn) of the hollow resin particles were measured using a particle size distribution analyzer, and the particle size distribution (Dv / Dn) was calculated. The measurement conditions were as follows: aperture diameter: 50 µm, dispersion medium: Isoton II (manufactured by Beckman Coulter, Inc.), concentration: 10%, number of measured particles: 100,000. Specifically, 0.2 g of a particle sample was placed in a beaker, and an aqueous surfactant solution (manufactured by FUJIFILM Corporation, product name: Drywell) was added thereto as a dispersant. 2 ml of the dispersion medium was further added thereto to wet the particles, then 10 ml of the dispersion medium was added, the particles were dispersed for 1 minute with an ultrasonic disperser, and then measurement was performed with the above particle size distribution analyzer. As the particle size distribution analyzer, Multisizer 4e, manufactured by Beckman Coulter, Inc., was used.

[0207] <<Measurement of Metal Content>> Wet decomposition of 10 g of precisely weighed hollow resin particles was performed using a microwave (PerkinElmer, Multiwave 3000). The resulting decomposition products were subjected to ICP emission spectrometry (PerkinElmer, Optima 2100 DV) to measure the total mass of metals. The type of metal was identified by elemental analysis using X-ray fluorescence analysis (XRF). The ratio of the total mass of metals in the decomposition products to the mass of the hollow resin particles was calculated and defined as the metal content in the hollow resin particles. The metal content of the hollow resin particles obtained in Synthesis Example 3 was 25 ppm.

[0208] <<Measurement of Relative Permittivity (Dk) and Dielectric Loss Tangent (Df) of Hollow Resin Particles>> The relative permittivity and dielectric loss tangent of hollow resin particles were measured at a frequency of 10 GHz and room temperature (25°C) using a perturbation-type measuring device (manufactured by AET, model: ADMS01Nc). The relative permittivity (Dk) of the hollow resin particles obtained in Synthesis Example 3 was 1.36, and the dielectric loss tangent (Df) was 2.41 × 10⁻⁶. －３ That was the case.

[0209] Example 1 Maleimide compound (DIC Corporation, NE-X-9500) 40 parts by mass, polyphenylene ether compound (D1) having a carbon-carbon unsaturated double bond at the terminal obtained in Synthesis Example 1, maleimide compound (Daiwa Chemical Industries, BMI-2300) 10 parts by mass, polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 2, phosphorus-based flame retardant (PX-200, Daihachi Chemical Industries, Ltd., 1,3-phenylenebis( 10 parts by mass of 2,6-dixylenyl phosphate, 40 parts by mass of solid silica (Admatex Co., Ltd., SC4500SQ), 1.1 parts by mass of hollow resin particles obtained in Synthesis Example 3, 1.3 parts by mass of silane coupling agent (Shin-Etsu Chemical Co., Ltd., KBM-1003), and 0.5 parts by mass of curing accelerator (dicumyl peroxide, NOF Corporation, Perkmyl D) were mixed, and the solid content was diluted to 65% by mass with methyl ethyl ketone to obtain a varnish. The amounts of each component mentioned above are shown in terms of solid content. The volume ratio of hollow resin particles to the total amount of solid silica and hollow resin particles obtained in Synthesis Example 3 is 19% by volume.

[0210] <Manufacturing of Metal Foil-Clad Laminates> The varnish obtained above was impregnated onto NE glass woven fabric (manufactured by Nitto Boseki Co., Ltd., N856 S101S), and heated and dried at 155°C for 5 minutes to obtain a prepreg (thickness 0.133 mm) with a resin composition content of 76 volume%. The properties of the NE glass woven fabric used are as follows: IPC applicable variety: 1078 Density (threads / 25 mm) vertical: 53 Density (threads / 25 mm) horizontal: 53 Thickness (mm): 0.043 Mass (g / m²) ２ ): 44 One or six of the obtained prepregs are stacked, and 12 μm thick electrolytic copper foil (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) is placed on both sides, and a pressure of 30 kgf / cm is applied. ２ Vacuum pressing was performed at a temperature of 220°C for 120 minutes to obtain a copper foil-clad laminate with an insulating layer thickness of 0.8 mm.

[0211] <Dielectric Properties (Dk and Df)> After removing the copper foil from the obtained 0.8 mm thick hardened plate by etching, it was downsized to 1 mm x 100 mm to obtain an evaluation sample. The obtained evaluation sample was dried at 120°C for 60 minutes, and then the relative permittivity (Dk) and dielectric loss tangent (Df) at 10 GHz were measured using a perturbation cavity resonator. The measurement temperature was 23°C. The perturbation cavity resonator used was Agilent 8722ES, a product of Agilent Technologies. The evaluation categories were as follows: <<Dk>> A: Less than 2.80 B: 2.80 or more and less than 2.90 C: 2.90 or more <<Df>> A: Less than 0.002 B: 0.002 or more and less than 0.003 C: 0.003 or more

[0212] <Coefficient of Thermal Expansion (CTE)> (CTE: Coefficient of linear Thermal Expansion) A test specimen obtained by etching off the copper foil from a 0.8 mm thick hardened plate was downsized to 5 mm x 5 mm to obtain an evaluation sample. The obtained evaluation sample was dried at 120°C for 60 minutes, and the coefficient of thermal expansion of the hardened plate was measured by the TMA method (Thermo-Mechanical Analysis) specified in JIS C 6481 5.19, and its value was determined. Specifically, after etching off the copper foil from both sides of the hardened plate obtained above, the temperature was increased from 50°C to 280°C at 10°C per minute using a thermomechanical analyzer (manufactured by TA Instruments), and the coefficient of linear thermal expansion (ppm / °C) was measured. ppm is the volume ratio. For other details, refer to JIS C 6481 5.19 above. The evaluation categories were as follows: A: 100 ppm / °C or less; B: greater than 100 ppm / °C and 130 ppm / °C or less; C: greater than 130 ppm / °C

[0213] <Peel Strength> Copper foil peel strength: For the obtained 8-layer metal foil laminate, the peel strength of the copper foil was measured in 3 tests using a test piece (30 mm × 150 mm × 0.8 mm) with 12 μm metal foil attached, in accordance with JIS C6481, and the average of the lower limits was taken as the measured value. Mitsui Mining & Smelting Co., Ltd.'s 3EC-M3-VLP with a thickness of 12 μm was used for the copper foil. The evaluation categories were as follows: A: 0.5 kN / m or more C: Less than 0.5 kN / m

[0214] <Heat Resistance> For the copper foil-clad laminates obtained in the above examples or comparative examples, test specimens (50 mm x 50 mm x 0.8 mm) with copper foil were prepared in accordance with JIS C5012:1992. The test specimens were floated in a bath containing solder heated to 288°C for 30 minutes, and then visually inspected for any abnormalities such as delamination in the copper foil-clad laminates. A and B in the table were evaluated according to the following criteria: A: No delamination after 30 minutes C: Delamination occurred in less than 30 minutes

[0215] Example 2 The procedure was the same as in Example 1, except that the content of solid silica was changed to 25 parts by mass and the content of hollow resin particles was changed to 2.8 parts by mass. The amount of filler (solid silica and hollow resin particles) in Example 2 was set so that the volume was the same as in Example 1. The same applies to Comparative Examples 1 to 3. The volume ratio of hollow resin particles to the total amount of solid silica and hollow resin particles obtained in Synthesis Example 3 is 50% by volume.

[0216] Example 3: In Example 1, the maleimide compound (DIC Corporation, NE-X-9500) was replaced with the same amount of maleimide compound (DIC Corporation, NE-X-9470S), and the rest of the procedure was carried out as before.

[0217] Example 4: In Example 1, the maleimide compound (DIC Corporation, NE-X-9500) was replaced with the same amount of maleimide compound (Nippon Kayaku Co., Ltd., MIR-3000-70MT), and the rest of the procedure was carried out as before.

[0218] Comparative Example 1: In Example 1, the content of solid silica was changed to 50 parts by mass, hollow resin particles were not added, and the rest of the procedure was the same.

[0219] Comparative Example 2: In Example 1, the solid silica content was changed to 25 parts by mass, hollow resin particles were not added, and 7.0 parts by mass of hollow silica (AGC Inc., HS-070, hollowness ratio 72%, specific gravity 0.62) were added, with the rest of the procedure being the same.

[0220] Comparative Example 3: In Example 1, the content of solid silica was changed to 25 parts by mass, hollow resin particles were not added, and 16.1 parts by mass of hollow silica (manufactured by JGC Catalysts & Chemicals Co., Ltd., product number: BA-S, hollowness ratio 37%, specific gravity 1.42) was added, and the content of the dispersant was changed to 0.8 parts by mass. Otherwise, the procedure was the same.

[0221] Comparative Example 4 The same procedure was followed as in Example 3, except that the content of solid silica was changed to 50.0 parts by mass and hollow resin particles were not included.

[0222] Comparative Example 5 The same procedure was followed as in Example 4, except that the content of solid silica was changed to 50.0 parts by mass and hollow resin particles were not included.

[0223]

[0224]

[0225] Although the present invention has been described in detail using specific embodiments, it will be apparent to those skilled in the art that various modifications are possible without departing from the intent and scope of the invention.

Claims

It contains a thermosetting resin and a filler, The curable resin contains a maleimide compound, The filler comprises a resin-containing shell and hollow resin particles having a hollow structure surrounded by the shell. Resin composition. The porosity of the hollow resin particles is 50% or more. The porosity is 100 - (apparent density D) of the hollow resin particles. １ / True density D ０ The resin composition according to claim 1, which is a value calculated from ) × 100. The resin composition according to claim 1 or 2, wherein the filler contains silica. The resin composition according to claim 1 or 2, wherein the proportion of the hollow resin particles in 100% by volume of the filler is 0.1% by volume or more and less than 60% by volume. The resin composition according to claim 1 or 2, wherein the thermosetting resin further comprises one or more selected from the group consisting of aromatic vinyl resins, cyanate ester compounds, epoxy compounds, and indan resins. The maleimide compound includes one selected from the group consisting of the compound represented by formula (M1), the compound represented by formula (M2), the compound represented by formula (M3), the compound represented by formula (M4), the compound represented by formula (M5), and the maleimide compound (M7). The resin composition according to claim 1 or 2, wherein the maleimide compound (M7) is a maleimide compound obtained by using as reaction raw materials (1) an aromatic amine compound (a1) having 1 to 3 alkyl groups on an aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride. In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ each independently represent a hydrogen atom or an organic group. R Ｍ５ and R Ｍ６ each independently represent a hydrogen atom or an alkyl group. Ar Ｍ represents a divalent aromatic group. A is a 4- to 6-membered alicyclic group. R Ｍ７ and R Ｍ８ each independently represent an alkyl group. mx is 1 or 2, and lx is 0 or 1. R Ｍ９ and R Ｍ１０ each independently represent a hydrogen atom or an alkyl group. R Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ each independently represent a hydrogen atom or an organic group. R Ｍ１５ each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group or a mercapto group. px represents an integer of 0 to 3. nx represents an integer of 1 to 20.) (In formula (M2), R ５４ Each of these independently represents a hydrogen atom or a methyl group, n ４ (This represents an integer greater than or equal to 1.) (In formula (M3), R ５５ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, n ５ (This represents an integer between 1 and 10, inclusive.) (In formula (M4), R ５６ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and R ５７ (Each of these independently represents either a hydrogen atom or a methyl group.) (In formula (M5), R ５８ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R ５９ Each of these independently represents a hydrogen atom or a methyl group, n ６ (This represents an integer greater than or equal to 1.) The resin composition according to claim 1 or 2, wherein the thermosetting resin has a group that reacts with carbon-carbon double bonds contained in the resin contained in the shell of the hollow resin particles. Furthermore, the resin composition according to claim 1 or 2, further comprising a flame retardant. The porosity of the hollow resin particles is 50% or more. The porosity is 100 - (apparent density D) of the hollow resin particles. １ / True density D ０ The value is calculated from ) × 100. The filler contains silica, In the filler, the proportion of the hollow resin particles is 0.1% by volume or more and less than 60% by volume. The thermosetting resin further comprises one or more selected from the group consisting of aromatic vinyl resins, cyanate ester compounds, epoxy compounds, and indan resins. The maleimide compound includes one selected from the group consisting of the compound represented by formula (M1), the compound represented by formula (M2), the compound represented by formula (M3), the compound represented by formula (M4), the compound represented by formula (M5), and the maleimide compound (M7). The maleimide compound (M7) is a maleimide compound that uses as reaction raw materials (1) an aromatic amine compound (a1) having 1 to 3 alkyl groups on an aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride. Furthermore, the resin composition according to claim 1, further comprising a flame retardant. (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ Each of these independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4-6 membered alicyclic group. R Ｍ７ and R Ｍ８ Each of these is independently an alkyl group. mx is 1 or 2, and lx is 0 or 1. Ｍ９ and R Ｍ１０ Each of these independently represents either a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ Each of these independently represents a hydrogen atom or an organic group. Ｍ１５ Each of these independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group. px represents an integer from 0 to 3. nx represents an integer from 1 to 20. (In formula (M2), R ５４ Each of these independently represents a hydrogen atom or a methyl group, n ４ (This represents an integer greater than or equal to 1.) (In formula (M3), R ５５ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, n ５ (This represents an integer between 1 and 10, inclusive.) (In formula (M4), R ５６ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and R ５７ (Each of these independently represents either a hydrogen atom or a methyl group.) (In formula (M5), R ５８ Each of these independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group, R ５９ Each of these independently represents a hydrogen atom or a methyl group, n ６ (This represents an integer greater than or equal to 1.) A cured product of the resin composition according to any one of claims 1, 2, and 9. A resin composite sheet comprising a support and a layer formed from the resin composition according to any one of claims 1, 2, and 9, disposed on the surface of the support. A prepreg formed from a substrate and a resin composition according to any one of claims 1, 2, and 9. A metal foil-clad laminate comprising at least one prepreg according to claim 12 and a metal foil disposed on one or both sides of the prepreg. A printed wiring board comprising an insulating layer and a conductor layer disposed on the surface of the insulating layer, wherein the insulating layer comprises a layer formed from the resin composition described in any one of claims 1, 2, and 9. A semiconductor device including a printed circuit board as described in claim 14.

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