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. A resin composition according to the present disclosure contains a compound (A) represented by formula (I) and a thermosetting compound (B), wherein the thermosetting compound (B) contains a compound represented by formula (M1), and the compound (A) content relative to 100 parts by mass of the resin solid content in the resin composition is 2-20 parts by mass.

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 recent years, the integration and miniaturization of semiconductor elements used in mobile devices, electronic equipment, and communication devices has accelerated. Consequently, technologies that enable high-density mounting of semiconductor elements are required, and improvements are needed in printed circuit boards, such as substrates for mounting semiconductor elements, which play a crucial role in this process. Meanwhile, the applications of electronic devices are diversifying and expanding. As a result, the properties required of printed circuit boards, such as substrates for mounting semiconductor elements, and the resin composite sheets, prepregs, and metal foil laminates used therein, are also diversifying, and the required performance is becoming more stringent. Materials that meet these stringent requirements are described, for example, in Patent Document 1.

[0003] Japanese Patent Publication No. 2023-98886

[0004] The materials described above tend to require low dielectric properties and suppression of warping in order to manufacture thin sheets and fine wiring. Furthermore, flame retardancy is also an important factor for ensuring safety. The present invention aims to solve these problems and to provide a resin composition that, when cured, achieves flame retardancy, low dielectric properties, and low warping, as well as a cured product, resin composite sheet, prepreg, metal foil-clad laminate, printed circuit board, and semiconductor device.

[0005] Based on the above problems, the inventors conducted studies and found that the above problems can be solved by using a predetermined phosphorus-containing compound and a predetermined maleimide compound. Specifically, the above problems were solved by the following means. [1] A resin composition comprising a compound (A) represented by formula (I) and a thermosetting compound (B), wherein the thermosetting compound (B) comprises a compound represented by formula (M1), and the content of compound (A) is 2 to 20 parts by mass per 100 parts by mass of resin solids in the resin composition. (In formula (I), each R independently represents an alkyl group having 1 to 10 carbon atoms, and each m independently represents an integer of 0 to 4.) (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ each independently represents a hydrogen atom or an organic group. R Ｍ５ and R Ｍ６ each independently represents a hydrogen atom or an alkyl group. Ar Ｍ represents a divalent aromatic group. A is an alicyclic group having 4 to 6 members. R Ｍ７ and R Ｍ８ are each independently an alkyl group. mx is 1 or 2, and lx is 0 or 1. R Ｍ９ and R Ｍ１０ each independently represents a hydrogen atom or an alkyl group. R Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ each independently represents a hydrogen atom or an organic group. 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. px represents an integer from 0 to 3. nx represents an integer from 1 to 20.) [2] The resin composition according to [1], wherein the phosphorus content in compound (A) is 2 to 15% by mass. [3] The resin composition according to [1] or [2], further comprising a styrene elastomer. [4] The resin composition according to any one of [1] to [3], wherein the thermosetting compound (B) comprises at least one selected from the group consisting of maleimide compounds other than the compound represented by formula (M1), aromatic resins having a carbon-carbon double bond at the terminal, 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 compounds having a vinylene group. [5] The resin composition according to any one of [1] to [4], wherein the thermosetting compound (B) comprises a polyphenylene ether compound having a carbon-carbon unsaturated double bond at the terminal. [6] The resin composition according to any one of [1] to [5], further comprising a peroxide catalyst. [7] A resin composition according to any one of [1] to [6], wherein the phosphorus content in compound (A) is 2 to 15% by mass, further comprising a styrene elastomer, the thermosetting compound (B) comprising a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus, and further comprising a peroxide catalyst. [8] A resin composition according to any one of [1] to [7], wherein m is 0 in compound (A) represented by formula (I). [9] A cured product of the resin composition according to any one of [1] to [8].

[10] A resin composite sheet comprising a support and a layer formed from the resin composition according to any one of [1] to [8] disposed on the surface of the support.

[11] A prepreg formed from a substrate and the resin composition according to any one of [1] to [8].

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

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

[13] A printed circuit board comprising an insulating layer and a conductive layer disposed on the surface of the insulating layer, wherein the insulating layer comprises a layer formed from any one of the resin compositions according to [1] to [8].

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

[13] .

[0006] The present invention makes it possible to provide a resin composition that, when cured, achieves flame retardancy, low dielectric strength, and low warping, as well as cured products, resin composite sheets, prepregs, metal foil-clad laminates, printed circuit boards, and semiconductor devices.

[0007] Hereinafter, embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment") will be described in detail. 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. "A~B" means A or greater and B or less. Furthermore, any combination of the upper and lower limits of numerical values ​​in this specification is given as an example of this embodiment. 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 and 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 and unsubstituted are used, 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.

[0008] 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.

[0009] In this specification, relative permittivity refers to the ratio of the dielectric constant of a material to the dielectric constant of a vacuum. In this specification, relative permittivity may also be simply referred to as "dielectric constant." Furthermore, unless otherwise specified, relative permittivity in this specification 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. If the standards shown in this specification differ in measurement methods, etc., from year to year, unless otherwise specified, the standards as of January 1, 2024 shall be used.

[0010] In this specification, "resin solids" means thermosetting resins, elastomers, and flame retardants, and does not include other components (fillers, solvents, dispersants, silane coupling agents, catalysts, etc.).

[0011] The resin composition of this embodiment is a resin composition comprising a compound (A) represented by formula (I) and a thermosetting compound (B), wherein the thermosetting compound (B) comprises a compound represented by formula (M1), and the content of compound (A) is 2 to 20 parts by mass per 100 parts by mass of resin solids in the resin composition. (In formula (I), R independently represents an alkyl group having 1 to 10 carbon atoms, and m independently represents an integer from 0 to 4.) (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.

[0012] By adopting this configuration, a resin composition is obtained that, when cured, achieves flame retardancy, low dielectric strength, and low warping. That is, it is presumed that by including compound (A) represented by formula (I), both flame retardancy and low warping were achieved. More specifically, compound (A) represented by formula (I) has three vinylbenzyl groups in its molecule, and it is presumed that when the resin composition is cured, the vinylbenzyl groups form a crosslinked structure with the maleimide group of compound (M1), thereby effectively suppressing warping. Furthermore, compound (M1) is inherently a low dielectric resin, and it is presumed that in this embodiment, this performance was fully exhibited, thus achieving low dielectric properties. Generally, low dielectric properties (Dk and / or Df), especially low Dk, tend to be improved by incorporating thermosetting compounds with long aliphatic chains or by incorporating elastomers. However, increasing the content of these components tends to increase warping, particularly the coefficient of thermal expansion (CTE). In other words, in the technical field of the present invention, low dielectric properties and low warpage were considered to be in a trade-off relationship. However, in this embodiment, by using a compound (A) represented by formula (I) and a thermosetting compound (B) in combination, we succeeded in obtaining a resin composition that is both low dielectric and low warpage when cured.

[0013] 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.

[0014] <Compound (A) represented by formula (I)> The resin composition of this embodiment contains compound (A) represented by formula (I). By using compound (A), warping of the resulting cured product can be suppressed, and flame retardancy can also be improved. (In formula (I), R independently represents an alkyl group having 1 to 10 carbon atoms, and m independently represents an integer from 0 to 4.)

[0015] R is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably an alkyl group having 1 to 4 carbon atoms. Specifically, R can be a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, s-butyl group, isobutyl group, t-butyl group, n-pentyl group, n-hexyl group, heptyl group, octyl group, nonyl group, decyl group, etc., and is more preferably a methyl group or a t-butyl group. The position of the vinyl group in formula (I) bonded to the benzene ring is preferably the ortho or para position relative to the oxygen atom derived from the phosphate group. m is an integer from 0 to 4, preferably 0 to 2, more preferably 0 or 1, and even more preferably 0. When m is 0, the low dielectric properties (Df and / or Dk, especially Df) of the cured product tend to be further improved.

[0016] In this embodiment, the phosphorus content in compound (A) is preferably 2 to 15% by mass, and more preferably 5 to 15% by mass. Setting it above the lower limit tends to further improve the flame resistance of the resulting cured product. Setting it below the upper limit tends to further improve compatibility with other thermosetting resins.

[0017] In this embodiment, the vinylbenzyl group equivalent of compound (A) is preferably 80 to 300 g / eq, and more preferably 100 to 200 g / eq. Setting it above the lower limit tends to further improve the low dielectric and low dielectric loss tangent of the cured product. Conversely, setting it below the upper limit tends to increase the glass transition temperature.

[0018] Examples of compound (A) used in this embodiment are shown below. It goes without saying that compound (A) used in this embodiment is not limited to the following: Tris(2,6-diisopropyl-4-vinylphenyl)phosphate Tris(2,6-di-t-butyl-4-vinylphenyl)phosphate

[0019]

[0020] The resin composition of this embodiment preferably contains two or more compounds (A), more preferably two or more selected from the above examples of compounds (A), and more preferably the following two compounds. Furthermore, when the resin composition of this embodiment contains the following two compounds, the mass ratio is preferably 10:90 to 90:10. With this configuration, it is possible to obtain a cured product with lower dielectric properties while maintaining excellent flame retardancy.

[0021] The content of compound (A) in the resin composition of this embodiment is 2 parts by mass or more, preferably 3 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. Depending on the application, it may be 6 parts by mass or more, 12 parts by mass or more, preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and even more preferably 13 parts by mass or less. Setting it above the lower limit tends to increase the Tg of the resulting compound and further improve the low dielectric properties (Dk and / or Df). Setting it below the upper limit tends to further improve the low thermal expansion properties of the resulting cured product. The resin composition of this embodiment may contain only one type of compound (A) or two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0022] The resin composition of this embodiment may or may not contain flame retardants other than compound (A). Examples of flame retardants other than compound (A) include phosphorus-based flame retardants other than compound (A), halogen-based flame retardants, inorganic flame retardants, and silicone-based flame retardants. Details of these can be found in paragraphs 0217 to 0218 of Japanese Patent Application Publication No. 2024-81683, which are incorporated herein by reference. Furthermore, the resin composition of this embodiment can be substantially free of 1,3-phenylenebis(2,6-dixylenyl phosphate). Furthermore, the resin composition of this embodiment may be substantially free of aluminum diethyl phosphinate, p-xylylene-bis-diphenylphosphine oxide, (2,5-diallyloxyphenyl)diphenylphosphine oxide, hexaphenoxycyclotriphosphazene, tris(2-allylphenoxy)triphenoxycyclotriphosphazene, resorcinol bis(di-2,6-dimethylphenyl phosphate), cyanophenoxy(phenoxy)cyclophosphazene, cresyloxy(phenoxy)cyclophosphazene, spirocyclophosphazene, and vinyl-containing phosphazene. "Substantially free" means that the content of such component in 100 parts by mass of the resin solids is less than 5 parts by mass, preferably less than 3 parts by mass, more preferably less than 1 part by mass, and even more preferably less than 0.1 parts by mass. The resin composition of this embodiment preferably substantially free of flame retardants other than compound (A). "Substantially free of flame retardants other than compound (A)" means that the content of flame retardants other than compound (A) in the resin composition is less than 15% by mass of the content of compound (A), preferably less than 10% by mass, more preferably less than 7% by mass, even more preferably less than 5% by mass, even more preferably less than 3% by mass, and may be less than 1% by mass.

[0023] <Thermosetting compound (B)> The resin composition of this embodiment contains a thermosetting compound (B). In this embodiment, the thermosetting compound (B) includes the compound represented by formula (M1), and may also include other thermosetting compounds. (In formula (M1), RＭ１ , 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.

[0024] Among the thermosetting compounds (B), it is preferable that the thermosetting compounds other than the compound represented by formula (M1) include at least one selected from the group consisting of maleimide compounds other than the compound represented by formula (M1), aromatic resins having a carbon-carbon double bond at the terminal, 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 compounds having a vinylene group, and it is more preferable that it includes a polyphenylene ether compound having a carbon-carbon unsaturated double bond at the terminal.

[0025] The total content of thermosetting compound (B) (including the compound represented by formula (M1)) in the resin composition in this embodiment is preferably 1 part by mass or more, more preferably 10 parts by mass or more, even more preferably 20 parts by mass or more, even more preferably 50 parts by mass or more, even more preferably 55 parts by mass or more, and may be 60 parts by mass or more, 65 parts by mass or more, and also preferably 99 parts by mass or less, more preferably 95 parts by mass or less, even more preferably 90 parts by mass or less, even more preferably 85 parts by mass or less, and may be less than 80 parts by mass. Setting the content above the lower limit tends to further improve the heat resistance and peel strength of the resulting cured product. Setting the content below the upper limit tends to further improve the low dielectric properties (Dk and / or Df) of the resulting cured product. The resin composition in this embodiment may contain only one type of thermosetting compound (B), 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.

[0026] <<Compound represented by formula (M1)>> The resin composition of this embodiment contains the compound represented by formula (M1). (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 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.

[0027] R in the formula Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ 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, and even more preferably a methyl group, ethyl group, propyl group, or butyl group, with the methyl group being particularly preferred. Ｍ１ and R Ｍ３ Each of these is independently preferably an alkyl group, R Ｍ２ and R Ｍ４ A hydrogen atom is preferred. Ｍ５ and R Ｍ６ 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. Ｍ Ar represents a divalent aromatic group, preferably a phenylene group, a naphthalenediyl group, a phenanthrenediyl group, or anthracenediyl group, more preferably a phenylene group, and even more preferably an m-phenylene group. Ｍ Ar may have substituents, preferably alkyl groups, more preferably alkyl groups having 1 to 12 carbon atoms, even more preferably alkyl groups having 1 to 6 carbon atoms, even more preferably methyl groups, ethyl groups, propyl groups, and butyl groups, with methyl groups being particularly preferred. However, Ar Ｍ It is preferable that it is unsubstituted. A is a 4- to 6-membered alicyclic group, and a 5-membered alicyclic group (preferably a group that combines with a benzene ring to form an indan ring) is more preferable. RＭ７ and R Ｍ８ and R are each independently an alkyl group, preferably an alkyl group having 1 to 6 carbon atoms, more preferably an alkyl group having 1 to 3 carbon atoms, and particularly preferably a methyl group. mx is 1 or 2, preferably 2. lx is 0 or 1, preferably 1. R Ｍ９ and R Ｍ１０ and R each independently represent a hydrogen atom or an alkyl group, with an alkyl group being more preferred. The alkyl group here preferably has 1 to 12 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. R Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ each independently represent 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, 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 particularly preferably a methyl group. R Ｍ１２ and R Ｍ１３ are each independently preferably an alkyl group, and R Ｍ１１ and R Ｍ１４ are preferably a hydrogen atom. R Ｍ１５Each 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 of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and still more preferably 0. nx represents an integer of 1 to 20. nx may be an integer of 10 or less. In addition, the resin composition in the present embodiment is a compound represented by the formula (M1), and may contain only one kind of compound having at least different nx values, or may contain two or more kinds. When two or more kinds are contained, the average value (average repeating unit number) n of nx in the compound represented by the formula (M1) in the resin composition is preferably 0.92 or more, more preferably 0.95 or more, still more preferably 1.0 or more, and even more preferably 1.1 or more in order to have a low melting point (low softening point), a low melt viscosity, and excellent handling properties. Further, n is preferably 10.0 or less, more preferably 8.0 or less, still more preferably 7.0 or less, even more preferably 6.0 or less, and may be 5.0 or less. The same applies to the formula (M1-1) and the like described later.

[0028] The compound represented by the formula (M1) is preferably a compound represented by the following formula (M1-1). (In the formula (M1-1), R Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ each independently represents a hydrogen atom or an organic group. R Ｍ２５ and R Ｍ２６ each independently represents a hydrogen atom or an alkyl group. R Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ each independently represents a hydrogen atom or an organic group. R 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.

[0029] 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 A alkyl group is 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.

[0030] 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.

[0031] 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.

[0032] The compound represented by formula (M1-1) is 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.) nx may also be an integer less than or equal to 10.

[0033] 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 (Dk and / or Df) 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.

[0034] Further details of the compound represented by formula (M1) can be found in International Publication No. 2020-217679, which is incorporated herein by reference.

[0035] The compound represented by formula (M1) may be a single compound or a mixture of two or more compounds. Examples of mixtures include a mixture of compounds with different nx values, a mixture of compounds with different types of substituents, a mixture of compounds with different bonding positions (meta, para, ortho) of the maleimide group to the benzene ring, and a mixture of compounds in which two or more of the above differences are combined. The same applies to the compounds represented by formulas (M0) and (M2) to (M8) below.

[0036] In this embodiment, the lower limit of the content of the compound represented by formula (M1) in the resin composition 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. When the content of the compound represented by formula (M1) is 1 part by mass or more, the low dielectric properties (Dk and / or Df) of the resulting cured product tend to improve. Furthermore, the upper limit of the content of the maleimide compound 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, even more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, and even more preferably 50 parts by mass or less, 45 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. When the content of the compound represented by formula (M1) is 90 parts by mass or less, the low thermal expansion properties tend to improve. The resin composition in this embodiment may contain only one compound represented by formula (M1), or it may contain two or more compounds. When it contains two or more compounds, it is preferable that the total amount is within the above range.

[0037] <<Maleimide Compounds Other Than the Compound Represented by Formula (M1)>> The resin composition in this embodiment preferably contains maleimide compounds other than the compound represented by formula (M1) (hereinafter referred to as "other maleimide compounds"). In this embodiment, the other 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. In this embodiment, the other maleimide compound preferably contains one or more selected from the group consisting of the compound represented by formula (M0), the compound represented by formula (M2), the compound represented by formula (M3), the compound represented by formula (M4), the compound represented by formula (M5), other maleimide compounds (M6), other maleimide compounds (M7), and other maleimide compounds (M8). It is more preferable to include one or more selected compounds, even more preferable to include one or more selected from the group consisting of compounds represented by formula (M0), compounds represented by formula (M3), compounds represented by formula (M4), and compounds represented by formula (M5), and even more preferable to include the compound represented by formula (M4). When these other maleimide compounds are used in printed circuit board materials (e.g., metal foil-clad laminates), excellent heat resistance can be imparted. In particular, using the compound represented by formula (M4) tends to improve low dielectric properties and low thermal expansion in a well-balanced manner.

[0038] (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 selected from the group consisting of 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, and a phenyl group, more preferably a hydrogen atom and / or a methyl group, and even more preferably a hydrogen atom. ５２ It is preferable that it is a methyl group. １ The integer is preferably between 1 and 10, more preferably between 1 and 5, even more preferably between 1 and 3, even more preferably 1 or 2, and even more preferably 1. Specifically, the following compounds are examples of preferred values ​​of formula (M0). In the above formula, R ８ Each of these independently represents a hydrogen atom, a methyl group, or an ethyl group, and a methyl group is preferred.

[0039] (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.) R ５４ It is preferably a hydrogen atom. 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.

[0040] (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.) ５５Each of these is preferably independently selected from the group consisting of 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, and a phenyl group, more preferably a hydrogen atom and / or a methyl group, and even more preferably a hydrogen atom. ５ n 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) is n ５ 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.

[0041] (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.) An example of a compound represented by formula (M4) is R ５６ Each is independently a methyl group or an ethyl group, R ５７ The R is a methyl group. ５６ It is more preferable that the two benzene rings are a methyl group and an ethyl group, respectively. Another example of a compound represented by formula (M4) is R ５６ Each is independently a methyl group or an ethyl group, R ５７ It is a hydrogen atom. Another example of a compound represented by formula (M4) is R ５６ and R ５７ The fact is that it is a hydrogen atom.

[0042] (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 ５８Each of these is preferably independently selected from the group consisting of 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, and a phenyl group, more preferably a hydrogen atom and / or a methyl group, and even more preferably a hydrogen atom. ５８ and R ５９ One example is that they are all hydrogen atoms. ５８ and R ５９ Another example is R ５８ is a methyl group, R ５９ It is a hydrogen atom. ５８ and R ５９ Another example is R ５８ is an ethyl group, R ５９ n is a hydrogen atom. 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 different parts.

[0043] Other maleimide compounds (M6) are compounds having the structure represented by formula (M6) and maleimide groups at both ends of the molecular chain. (In formula (M6), R ６１ 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. 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. ６３Each 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 other maleimide compounds (M6) and methods for their preparation can be found in paragraphs 0061 to 0066 of International Publication No. 2020 / 262577, which are incorporated herein by reference.

[0044] Other maleimide compounds (M7) are other maleimide compounds that use an aromatic amine compound (a1) having one to three alkyl groups on the aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride as reaction raw materials (1). Preferably, other maleimide compounds (M7) are compounds 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, 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 R ７ and R ８ One side is a hydrogen atom, and the other side is a methyl group, R ９Each 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 ６ Preferably, one of the elements is a hydrogen atom and the other is a methyl group. Preferably, p is 1. Preferably, q is an integer from 0 to 2, more preferably 0 or 1, and even more preferably 1. Preferably, r is 0. Preferably, k is 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. n is the same as k above.

[0045] Details of other maleimide compounds (M7) used in this embodiment can be found in the description of Japanese Patent No. 7160151, which is incorporated herein by reference. The resin composition of this embodiment may also be substantially free of other maleimide compounds (M7), namely, maleimide compounds that react with an aromatic amine compound (a1) having one to three alkyl groups on an aromatic ring, an aromatic divinyl compound (a2) having two ethenyl groups, and maleic anhydride as reaction raw materials. Substantially free of other maleimide compounds (M7) means that the content of other maleimide compounds (M7) in the resin composition is less than 15% by mass of the total amount of maleimide compounds in the resin composition, preferably less than 10% by mass, more preferably less than 7% by mass, even more preferably less than 5% by mass, even more preferably less than 3% by mass, and may be less than 1% by mass or 0% by mass.

[0046] The other maleimide compound (M8) is a bis-maleimide 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 other 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.

[0047] 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.

[0048] Other maleimide compounds (M8) can be found 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.

[0049] Other maleimide compounds may be produced by known methods or commercially available products may be used. Examples of commercially available products include, for example, "BMI-80" manufactured by K.I. Chemicals Co., Ltd. as the compound represented by formula (M0), "NE-X-9470S" and "NE-X-9480S" manufactured by DIC Corporation as the compound represented by formula (M1), "BMI-2300" manufactured by Yamato Chemical Industries Co., Ltd. as the compound represented by formula (M2), "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd. as the compound represented by formula (M3), and the compound represented by formula (M4) Examples of compound products include "BMI-70" manufactured by K.I. Chemicals Co., Ltd. and "BMI-5100" manufactured by Yamato Chemical Industries Co., Ltd., as a compound represented by formula (M5), "MIR-5000" manufactured by Nippon Kayaku Co., Ltd., as another maleimide compound (M6), "MIZ-001" manufactured by Nippon Kayaku Co., Ltd., as another maleimide compound (M7), "NE-X-9500" manufactured by DIC Corporation, and as another maleimide compound (M8), "SFR" manufactured by Resonaq Corporation, and "BMI-689", "BMI-1500", "BMI-2500", "BMI-3000", and "BMI-5000" manufactured by DESIGNER MOLECULES INC. In addition, "NE-X-9600" manufactured by DIC Corporation can also be used as another maleimide compound with three or more functions.

[0050] Other maleimide compounds not mentioned above include, for example, oligomers of N-phenylmaleimide, N-cyclohexylmaleimide, phenylmethanemaleimide, 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, and prepolymers of these maleimides with amines. In addition to the above, the compounds described in paragraphs 0051 to 0068 of International Publication No. 2020 / 262577 can be referenced, and this content is incorporated herein. Furthermore, the maleimide compound used in this embodiment preferably does not contain alkylene groups having 5 or more carbon atoms, and more preferably does not contain alkylene groups having 6 or more carbon atoms. The number of carbon atoms in the alkylene group is usually 20 or less, and more preferably 10 or less.

[0051] The maleimide group equivalent of other maleimide compounds 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, even more preferably 290 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 low thermal expansion properties of the resulting cured product. The maleimide group equivalent of the above maleimide compounds is measured at 500 MHz for the maleimide compounds. 1The amount of maleimide group is determined by measuring the 1H-NMR spectrum and using dimethyl sulfoxide as an internal standard to obtain the integral value of the hydrogen atoms of the maleimide group, and then calculated from its reciprocal.

[0052] If the resin composition in this embodiment contains other maleimide compounds, the lower limit of their content 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, per 100 parts by mass of resin solids in the resin composition. A content above the lower limit tends to improve the flame resistance of the resulting cured product. The upper limit of the content of other maleimide compounds 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, even more preferably 60 parts by mass or less, even more preferably 55 parts by mass or less, and even more preferably 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less, depending on the application. A content below the upper limit tends to improve the low dielectric properties (Dk and / or Df). The resin composition in this embodiment may contain only one type of other 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.

[0053] <<Aromatic Resins Having Carbon-Carbon Double Bonds at the Terminals>> Aromatic resins having carbon-carbon double bonds at the terminals are, for example, compounds that have carbon-carbon double bonds at the terminals and contain aromatic rings, and are compounds that harden with heat. Aromatic resins having carbon-carbon double bonds at the terminals tend to have low dielectric constant and low dielectric loss tangent due to their low polarity skeleton. Specifically, aromatic resins having carbon-carbon double bonds at the terminals preferably include one or more selected from the group consisting of polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals, polymers having structural units represented by formula (V), and resins having terminal groups represented by formula (T1) and having an indan skeleton. It is more preferable to include polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals and / or resins having terminal groups represented by formula (T1) and having an indan skeleton, and it is even more preferable to include polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals. Polyphenylene ether compounds having carbon-carbon unsaturated double bonds at their terminals polymerize particularly effectively with the compound represented by formula (M1), thereby improving the physical properties of the resulting cured product. Furthermore, the compatibility between the compound represented by formula (I) and the compound represented by formula (M1) can be improved, enabling the achievement of even lower dielectric properties in the resulting cured product.

[0054] In this embodiment, if the resin composition contains an aromatic resin having carbon-carbon double bonds at its ends, the content is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, and also preferably 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, and depending on the application, even more preferably 50 parts by mass or less, even more preferably 40 parts by mass or less, and further, it may be 35 parts by mass or less, 30 parts by mass or less, or 25 parts by mass or less. By setting the content of the aromatic resin having carbon-carbon double bonds at its ends to above the lower limit, the compatibility and heat resistance of the thermosetting compound tend to improve further. Also, by setting the content of the aromatic resin having carbon-carbon double bonds at its ends to below the upper limit, the low thermal expansion properties tend to improve further. The resin composition in this embodiment may contain only one aromatic resin having a carbon-carbon double bond at its terminus, or it may contain two or more aromatic resins. When two or more aromatic resins are included, it is preferable that the total amount is within the above range.

[0055] <<<Polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the terminals>>> The resin composition in 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.

[0056] 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).

[0057] (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.)

[0058] 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 ).

[0059] 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 groups selected from the group consisting of (meth)acryloyl groups and 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.

[0060] 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 a polyphenylene ether structure, where n1 is an integer from 1 to 100, and n2 is an integer from 1 to 4. Rx is a group represented by formula (Rx-1) or formula (Rx-2). (In equations (Rx-1) and (Rx-2), 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.

[0061] 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 later can be an example, but it is preferable that it is 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 １The 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.

[0062] In equations (Rx-1) and (Rx-2), 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.

[0063] 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.

[0064] 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.

[0065] A specific example of the group represented by formula (Rx-1) is the vinylbenzyl group, and a specific example of the group represented by formula (Rx-2) is the (meth)acryloyl group.

[0066] The resin composition in this embodiment is a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus, and is preferably a compound represented by formula (OP), which may include both a polyphenylene ether compound having a group represented by formula (Rx-1) and a polyphenylene ether compound having a group represented by formula (Rx-2).

[0067] 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.

[0068] 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 ８ 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] (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).

[0074] 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.

[0075] 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 a and b is an integer between 1 and 100.)

[0076] 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 SA9000 from SABIC Innovative Plastics, which is a modified polyphenylene ether compound with a methacryloyl group at the terminal. Examples of modified polyphenylene ether compounds with a vinylbenzyl group at the terminal include OPE-2St1200 and OPE-2St2200 from Mitsubishi Gas Chemical Company. Furthermore, as a modified polyphenylene ether compound with a vinylbenzyl group at the terminal, it is also possible to use a polyphenylene ether compound with a hydroxyl group at the terminal, such as SA90 from SABIC Innovative Plastics, which has been modified to have a vinylbenzyl group using vinylbenzyl chloride or the like.

[0077] 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.

[0078] 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)) is preferably 500 to 3,000, as determined by GPC (gel permeation chromatography). A number-average molecular weight of 500 or more tends to further suppress stickiness when the resin composition in 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)) as determined by GPC 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, low viscosity, and moldability of the resin composition when producing varnishes, etc., as described later tend to be improved. Furthermore, for polyphenylene ether compounds having carbon-carbon unsaturated double bonds at the 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 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, low viscosity, and moldability of the resin composition tend to be improved.

[0079] The functional group equivalent (equivalent of carbon-carbon unsaturated double bond) in polyphenylene ether compounds having a carbon-carbon unsaturated double bond at the terminal is calculated by determining the amount of double bond from the measurement results using an infrared spectrometer and then calculating the reciprocal. The double bond equivalent [g / eq.] was determined as follows: The weight of the polyphenylene ether 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 amount. 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 vinyl groups in polyphenylene ether compounds, 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.

[0080] In this embodiment, if the resin composition 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 10 parts by mass or more, even more preferably 15 parts by mass or more, even more preferably 20 parts by mass or more, and also preferably 90 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, and depending on the application, it may be 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, or 25 parts by mass or less. 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. By keeping the content of polyphenylene ether compounds having carbon-carbon unsaturated double bonds at their ends below the aforementioned 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 type of polyphenylene ether compound having carbon-carbon unsaturated double bonds at its ends, 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.

[0081] <<<Polymer having a constituent unit represented by formula (V)>>> The resin composition in 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.

[0082] 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.

[0083] 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)".

[0084] 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.

[0085] 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.

[0086] Other monomer-derived structural units include structural unit (b) derived from an aromatic compound having one vinyl group (monovinyl aromatic compound).

[0087] The constituent unit (b) derived from the monovinyl aromatic compound is preferably a constituent unit represented by the following formula (V4).

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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 at least one of structural units (b) and (c) is included. Furthermore, an embodiment is provided in which the sum of structural units (a) to (c) accounts for 90 mol% or more, more preferably 95 mol% or more, and particularly preferably 98 mol% or more of the total structural units. As another embodiment of a polymer having a structural unit represented by formula (V), a polymer is provided in which structural unit (a) is essential and at least one of structural units (b) to (d) is included. Furthermore, an embodiment is provided in which the sum of structural units (a) to (d) accounts for 95 mol% or more, more preferably 98 mol% or more of the total structural units. As yet 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 of structural units including aromatic rings among all structural units excluding the terminals, more preferably 95 mol% or more, and may also be a polymer of 100 mol%. In calculating the mole percentage per total constituent unit, one constituent unit is defined as one molecule of the monomer (e.g., divinyl aromatic compound, monovinyl aromatic compound, etc.) used in the production of a polymer having a constituent unit represented by formula (V).

[0095] 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.

[0096] 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)

[0097] 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)

[0098] 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 (Dk and / or Df), particularly Df and dielectric properties after moisture absorption, of the polymer having the constituent unit represented by formula (V) 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, when the prepreg or resin sheet is laminated onto a circuit forming substrate, embedding defects tend to be less likely to occur. The monodispersity (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the 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. When the resin composition in this embodiment contains two or more polymers having a constituent unit represented by formula (V), it is preferable that the Mw, Mn, and Mw / Mn of the mixture satisfy the above ranges.

[0099] 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.

[0100] Polymers having a constituent unit represented by formula (V) preferably have cured products with excellent low dielectric properties (Dk and / or Df). 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 held at 200°C for 2 hours and pressed at a surface pressure of 3.0 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.

[0101] 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. A polymer having the constituent unit represented by formula (V) can be a commercially available product, such as LF-310T50 manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0102] In this embodiment, if the resin composition 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 5 parts by mass or more, even more preferably 10 parts by mass or more, and depending on the application, it may be 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more. By setting the content of the polymer having a structural unit represented by formula (V) to 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, even more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, and may be 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less, based on 100 parts by mass of resin solids in the resin composition. By keeping the content of polymers having the structural unit represented by formula (V) below the above upper limit, the metal foil peel strength and low water absorption tend to improve. The resin composition in this embodiment may contain only one type of polymer having the structural unit represented by formula (V), 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 in this embodiment may also be configured to substantially not contain polymers having the structural unit represented by formula (V). Substantially not containing polymers means that the content of polymers having the structural unit represented by formula (V) is less than 1 part by mass per 100 parts by mass of resin solids in the resin composition, preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.

[0103] << (In formula (T1), Mb represents a hydrocarbon group having 1 to 12 carbon atoms, which may each be independently substituted with a halogen atom, and y represents an integer from 0 to 4. * represents the bond position with other sites.) For details of the aromatic resin having a carbon-carbon double bond at its terminus, which has a terminus represented by formula (T1) and an indan skeleton, please refer to paragraphs 0012 to 0033 of Japanese Patent Application Publication No. 2024-081683, which are incorporated herein by reference.

[0104] In this embodiment, if the resin composition contains a resin having an end group represented by formula (T1) and an indan skeleton, 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 10 parts by mass or more, and depending on the application, it may be 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more. By setting the content of the resin having an end group represented by formula (T1) and an indan skeleton to the above lower limit or higher, low dielectric properties, in particular low relative permittivity, tend to be effectively achieved. Furthermore, the upper limit of the content of the resin having an end group represented by formula (T1) and an indan skeleton 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, even more preferably 60 parts by mass or less, and may be 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, or 30 parts by mass or less, based on 100 parts by mass of resin solids in the resin composition. By keeping the content of the resin having an end group represented by formula (T1) and an indan skeleton below the above upper limit, the metal foil peel strength and low water absorption tend to improve. The resin composition in this embodiment may contain only one type of resin having an end group represented by formula (T1) and an indan skeleton, 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 in this embodiment may also be configured to substantially not contain the resin having an end group represented by formula (T1) and an indan skeleton. Substantially not containing means that the content of the resin having an end group represented by formula (T1) and an indan skeleton is less than 1 part by mass per 100 parts by mass of resin solids in the resin composition, preferably less than 0.1 parts by mass, and more preferably less than 0.01 parts by mass.

[0105] <<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 compounds having a vinylene group>> The resin composition of this embodiment may contain at least one of the following: 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 compounds having a vinylene group. Details of these compounds can be found in paragraphs 0121 to 0159 of Japanese Patent Application Publication No. 2024-081683 and paragraphs 0173 to 0225 of International Publication No. 2024 / 101238, the contents of which are incorporated herein by reference.

[0106] In the resin composition of this embodiment, the content of 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 compounds having a vinylene group is, independently, 0 parts by mass or more, 1 part by mass or more, 10 parts by mass or more, preferably 90 parts by mass or less, more preferably 50 parts by mass, 10 parts by mass or less, 5 parts by mass or less, 1 part by mass or less, and depending on the application, it may be 0.1 parts by mass or less, or 0.01 parts by mass or less.

[0107] <Styrene-based elastomer> The resin composition of this embodiment preferably contains a styrene-based elastomer. By including a styrene-based elastomer, a cured product with low dielectric, low dielectric loss tangent, and low warpage can be obtained. In particular, the toughness of the resin composition when it is in the B stage can be further improved. The styrene-based elastomer is an elastomer containing 10% by mass or more of styrene units. The styrene unit content in the styrene-based elastomer is more preferably 30% by mass or more, even more preferably 40% by mass or more, preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, and most preferably 55% by mass or less. When the styrene unit content is above the lower limit, compatibility and low thermal expansion tend to be good, which is preferable. Furthermore, by keeping the styrene unit content below the upper limit, the low dielectric properties become even better. The styrene-based elastomer may contain only one type of styrene unit, or it may contain two or more types of styrene units. When it contains two or more types of styrene units, it is preferable that the total amount is within the above range.

[0108] Examples of styrene compounds that constitute a styrene unit include styrene, α-methylstyrene, p-methylstyrene, divinylbenzene (vinylstyrene), N,N-dimethyl-p-aminoethylstyrene, and N,N-diethyl-p-aminoethylstyrene. Among these, styrene, α-methylstyrene, and p-methylstyrene are preferred from the viewpoint of availability and productivity. Styrene is particularly preferred among these.

[0109] The styrene-based elastomer also preferably contains one or more units selected from the group consisting of butadiene units, isoprene units, hydrogenated butadiene units, and hydrogenated isoprene units (hereinafter sometimes referred to as "conjugated diene unit A"). The above styrene-based elastomer also preferably contains butadiene units (preferably 2,3-butadiene units and 1,2-butadiene units).

[0110] In the above-mentioned styrene-based elastomer, the mass ratio of styrene units to conjugated diene units A is preferably in the range of styrene units / conjugated diene units A = 5 / 95 to 75 / 25, more preferably in the range of 30 / 70 to 65 / 35, even more preferably in the range of 35 / 65 to 60 / 40, and even more preferably in the range of 35 / 65 to 55 / 45. If the mass ratio of styrene units to conjugated diene units A is within the above range, compatibility and heat resistance will be good.

[0111] The above-mentioned styrene-based elastomer may or may not contain other monomer units in addition to styrene units and conjugated diene units A. Examples of other monomer units include aromatic vinyl compound units other than styrene units. Preferably, the total amount of styrene units and conjugated diene units A in the above-mentioned styrene-based elastomer is 90% by mass or more, more preferably 95% by mass or more, even more preferably 97% by mass or more, even more preferably 99% by mass or more, and also 100% by mass or less. As described above, the styrene-based elastomer may contain only one type of styrene unit and conjugated diene unit A, or two or more types. When two or more types are included, it is preferable that the total amount is within the above range.

[0112] The styrene-based elastomer used in this embodiment may be a block polymer or a random polymer. Furthermore, the conjugated diene unit A may be a hydrogenated elastomer containing hydrogenated butadiene units and / or hydrogenated isoprene units, an unhydrogenated elastomer not containing hydrogenated butadiene units and / or hydrogenated isoprene units, or a partially hydrogenated elastomer containing butadiene units and / or isoprene units and hydrogenated butadiene units and / or hydrogenated isoprene units. It is preferable that it be an unhydrogenated elastomer or a partially hydrogenated elastomer. In one embodiment of this embodiment, the styrene-based elastomer is a hydrogenated elastomer. Here, the hydrogenated elastomer includes not only those with a hydrogenation rate (hydrogenation ratio) of 100%, but also those with a hydrogenation rate of 80% or more. The hydrogenation rate in the hydrogenated elastomer is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. 1 This is calculated from the measurement results of 1H-NMR spectroscopy. In another embodiment of this invention, the styrene-based elastomer is an unhydrogenated elastomer. Here, an unhydrogenated elastomer refers to one in which the proportion of double bonds based on conjugated diene units A in the elastomer that are hydrogenated, i.e., the hydrogenation rate, is 20% or less. The hydrogenation rate is preferably 15% or less, more preferably 10% or less, and even more preferably 5% or less. On the other hand, a partially hydrogenated elastomer means one in which some of the double bonds based on conjugated diene units A in the elastomer are hydrogenated, and usually refers to one in which the hydrogenation rate is less than 80% and more than 20%.

[0113] Styrene-based elastomers may have reactive functional groups at their molecular ends or in their molecular chains. Examples of reactive functional groups include epoxy groups, hydroxyl groups, carboxyl groups, amino groups, amide groups, isocyanate groups, acryloyl groups, methacryloyl groups, and vinyl groups. From the viewpoint of adhesion to metals, the reactive functional groups are preferably epoxy groups, hydroxyl groups, carboxyl groups, amino groups, or amide groups, and from the viewpoint of further improving heat resistance and insulation reliability, epoxy groups, hydroxyl groups, or amino groups are more preferable. It is preferable that the styrene-based elastomer used in this embodiment does not have reactive functional groups.

[0114] Specific examples of styrene-based elastomers include at least one selected from the group consisting of styrene-butadiene-styrene elastomer (SBS), styrene-isoprene-styrene elastomer (SIS), polystyrene-poly(ethylene-propylene) elastomer (SEP), polystyrene-poly(ethylene-propylene)-polystyrene elastomer (SEPS), polystyrene-poly(ethylene-butylene)-polystyrene elastomer (SEBS), and polystyrene-poly(ethylene / ethylene-propylene)-polystyrene elastomer (SEEPS), with styrene-butadiene-styrene elastomer (SBS) being preferred. In particular, in this embodiment, SBS containing butadiene units having a 1,2-vinyl structure is preferred, and SBS in which 70 to 100% by mass of the butadiene units are butadiene units having a 1,2-vinyl structure is more preferred. Using such a styrene elastomer can further improve the toughness of the resin composition when it is in the B-stage state.

[0115] The number-average molecular weight of the styrene-based elastomer used in this embodiment is preferably 1,000 or more. By setting the number-average molecular weight to 1,000 or more, the low dielectric properties (Dk and / or Df, particularly low dielectric loss tangent) of the resulting cured product tend to be better. The number-average molecular weight is preferably 1,500 or more, more preferably 2,000 or more, preferably 200,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less. By setting the number-average molecular weight to or below the above upper limit, the solubility of the styrene-based elastomer component in the resin composition tends to improve. When the resin composition of this embodiment contains two or more styrene-based elastomers, it is preferable that the number-average molecular weight of the mixture thereof satisfies the above range.

[0116] Examples of commercially available styrene-based elastomers used in this embodiment include SEPTON® 2104, V9461, and S8104 from Kuraray Co., Ltd., S.O.E.® S1606, S1613, S1609, and S1605 from Asahi Kasei Corporation, ToughTec® H1041, H1043, P2000, and MP10 from Asahi Kasei Corporation, DYNARON® 9901P and TR2250 from ENEOS Material Co., Ltd., and 1,2-SBS-P35 from Nippon Soda Co., Ltd.

[0117] When the resin composition of this embodiment contains a styrene-based elastomer, its content is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, and depending on the application, it may be 12 parts by mass or more, 15 parts by mass or more, or 18 parts by mass or more, and also preferably 30 parts by mass or less, more preferably 28 parts by mass or less, even more preferably 26 parts by mass or less, even more preferably 24 parts by mass or less, and even more preferably 22 parts by mass or less. Setting it above the lower limit tends to further improve the low dielectric loss tangent. Setting it below the upper limit tends to further improve the heat resistance. The resin composition of this embodiment may contain only one type of styrene-based elastomer, or it may contain two or more types. When two or more types of styrene-based elastomers are included, it is preferable that the total amount is within the above range.

[0118] <Peroxide Catalyst> The resin composition of this embodiment may further contain a peroxide catalyst. By incorporating a peroxide catalyst, the curing temperature of the resin composition in the B-stage state can be lowered, for example, to less than 200°C, and particularly to 175°C or more and less than 185°C. Therefore, the resin composition of this embodiment is preferably a radical polymerizable resin composition that promotes the curing reaction by radical polymerization. The peroxide catalyst is not particularly limited, but examples include organic peroxides such as benzoyl peroxide, lauroyl peroxide, acetyl peroxide, parachlorobenzoyl peroxide, di-tert-butyl-di-perphthalate, α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexyn-3, with α,α'-di(t-butylperoxy)diisopropylbenzene being preferred.

[0119] When the resin composition of this embodiment contains a peroxide catalyst, the lower limit of its content is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. The upper limit of the peroxide catalyst 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 1.5 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 especially 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 of this embodiment is preferable in that the resin composition can be sufficiently cured even if the peroxide catalyst content is 0.8 parts by mass or less. The peroxide catalyst 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.

[0120] <Other curing accelerators> The resin composition of this embodiment may contain other curing accelerators in addition to the peroxide catalyst. Other curing accelerators include imidazole catalysts such as 2-ethyl-4-methylimidazole and triphenylimidazole; azo compounds such as azobisnitrile; tertiary amines such as 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; and phenols such as xylenol, cresol, resorcinol, and catechol. Examples of curing accelerators include: ions; high-temperature decomposition type 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. Among these, the preferred curing accelerator is at least one selected from the group consisting of imidazole catalysts and organometallic salts, with imidazole catalysts being more preferred.

[0121] If the resin composition of this embodiment contains other curing accelerators, the lower limit of their content is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. The upper limit of the content of other curing accelerators 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 1.5 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 especially most preferably 0.7 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. The other curing accelerators can be used individually or in combination of two or more types. When two or more types are used, the total amount will be within the above range.

[0122] The resin composition of this embodiment preferably contains both a peroxide catalyst and an imidazole catalyst. This configuration allows the curing reaction to proceed more effectively. Specifically, the inclusion of both a peroxide catalyst and an imidazole catalyst reduces the number of residual groups, thereby significantly reducing the exothermic peak above 300°C measured by differential scanning calorimeter (DSC) and increasing the amount of heat generated at the main peak around 150°C, thereby improving the reactivity of the curing reaction. The mass ratio of the peroxide catalyst to the imidazole catalyst is preferably 1:0.1 to 2.0, and more preferably 1:0.5 to 1.5. This mass ratio tends to allow the resin composition to be cured at a lower temperature.

[0123] <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.

[0124] 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.

[0125] <Aromatic Oligomers> The resin composition of this embodiment may contain aromatic oligomers. An aromatic oligomer is an oligomer having structural units derived from an aromatic vinyl compound, and usually refers to a compound with a weight-average molecular weight of less than 3000. An aromatic oligomer is also usually a thermoplastic oligomer. In this embodiment, the aromatic oligomer does 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. Examples of the 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, and divinylbenzene. These aromatic vinyl compounds may be used individually or in combination of two or more. Among these, styrene, α-methylstyrene, and 4-methylstyrene are preferred, with α-methylstyrene being more preferred.

[0126] 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.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] 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.

[0131] When the resin composition of this embodiment contains aromatic oligomers, the 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. The upper limit of the aromatic oligomer content is preferably 45 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 10 parts by mass or less, and may be 8 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 oligomer, 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.

[0132] <Filler> The resin composition in 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. Furthermore, it is more preferable that the filler used in this embodiment has excellent low dielectric properties (Dk and / or Df). For example, the filler used in this embodiment preferably has a relative permittivity (Dk) of 8.0 or less, more preferably 6.0 or less, and even more preferably 4.0 or less at a frequency of 10 GHz measured according to the cavity resonator perturbation method. Furthermore, the lower limit of the relative permittivity is practically set to, for example, 2.0 or higher. Furthermore, the filler used in this embodiment preferably has a dielectric loss tangent (Df) of 0.05 or less, more preferably 0.01 or less, at a frequency of 10 GHz measured according to the cavity resonator perturbation method. Furthermore, the lower limit of the dielectric loss tangent is practically set to, for example, 0.0001 or higher.

[0133] The type of filler used in this embodiment is 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, hollow silica, etc.; metal oxides such as alumina, white carbon, titanium white, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, etc.; composite oxides such as zinc borate, zinc stannate, forsterite, barium titanate, strontium titanate, calcium titanate, etc.; nitrides such as boron nitride, aggregated boron nitride, silicon nitride, aluminum nitride, etc.; aluminum hydroxide, heat-treated aluminum hydroxide (aluminum hydroxide that has been heat-treated to reduce some of the crystal water), boehmite, magnesium hydroxide, etc. (including hydrates); 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, 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.

[0134] The filler content 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 may be 30 parts by mass or more, 50 parts by mass or more, or 90 parts by mass or more, depending on the application, etc. Setting it above the lower limit tends to result in better low thermal expansion and low dielectric loss tangent of the resulting cured product. Furthermore, the upper limit of the filler content is preferably 300 parts by mass or less, more preferably 250 parts by mass or less, even more preferably 200 parts by mass or less, and even more preferably 180 parts by mass or less, and may be 150 parts by mass or less or 110 parts by mass or less, depending on the application, etc. 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 filler or two or more types. When two or more types of fillers are included, it is preferable that the total amount be within the above range.

[0135] In the resin composition of this embodiment, as an example of the embodiment, there is a form in which the filler content is 1 to 95% by mass of the components excluding the solvent, and a form in which it is 10% to 60% by mass is preferred.

[0136] As another example of the embodiment of this model, a configuration that is substantially free of fillers is also possible. "Substantially free of fillers" means, for example, that the filler content is less than 1% by mass of the components excluding the solvent, and preferably less than 0.5% by mass.

[0137] In the resin composition of this embodiment, when a filler, particularly 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 may be 0.1 to 5.0 parts by mass per 100 parts by mass of resin solids in the resin composition.

[0138] <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.

[0139] 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 be 0.3 parts by mass or more, per 100 parts by mass of resin solids in the resin composition. The upper limit of the dispersant content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and may be 3 parts by mass or less, per 100 parts by mass of resin solids in the resin composition. One type of dispersant can be used alone, or two or more types can be used in combination. When two or more types are used, the total amount will be within the above range.

[0140] <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 used in this embodiment is preferably a mixture of a polar organic solvent and a nonpolar organic solvent. The mass ratio of the polar organic solvent to the nonpolar organic solvent in the mixture is preferably 10:90 to 90:10. With this configuration, the resin solids contained in the resin composition of this embodiment can be dissolved more easily and with higher dispersibility. The solvent 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.

[0141] <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, photopolymerization initiators, fluorescent whitening agents, photosensitizers, dyes, pigments, thickeners, flow regulators, lubricants, defoamers, leveling agents, glossing 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 additives 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 also be 0 parts by mass or more and less than 0.5 parts by mass, per 100 parts by mass of resin solids.

[0142] In this embodiment, the resin composition preferably contains a compound (A) represented by formula (I), a thermosetting compound (B), a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus, and a styrene-based elastomer, with the total of these accounting for 90% or more by mass of the resin solids, more preferably 95% or more by mass, and even more preferably 98% or more by mass.

[0143] <Applications> The resin composition of this embodiment is used as a cured product. 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 can be suitably used as a material for resin composite sheets, prepregs, metal foil-clad laminates and printed circuit boards.

[0144] The resin composition of this embodiment preferably has a low relative permittivity (Dk) and dielectric loss tangent (Df) in its cured product. Specifically, it is preferable that the relative permittivity (Dk) and dielectric loss tangent (Df) of a sample obtained by removing the metal foil from a metal foil-clad laminate molded with the resin composition of this embodiment are low. More specifically, it is preferable that the dielectric loss tangent (Df) at a frequency of 10 GHz measured by the cavity resonator perturbation method in accordance with JIS C218:2007 of a sample molded with the resin composition to a thickness of 0.8 mm and a size of 1 mm x 100 mm is less than 0.0016, and more preferably less than 0.0012. There is no particular lower limit for the dielectric loss tangent (Df), but for example, 0.0001 or higher is practical. Furthermore, the relative permittivity (Dk) at a frequency of 10 GHz, measured by the cavity resonator perturbation method in accordance with JIS C218:2007 for the above-mentioned sample, is preferably less than 2.4, and more preferably less than 2.35. There is no specific 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 more specifically by the method described in the examples below.

[0145] The resin composition of this embodiment is also preferably characterized by a small curvature (coefficient of thermal expansion) when cured. When a sample of the resin composition molded to a thickness of 0.8 mm and a size of 5 mm x 5 mm is heated from 25°C to 303°C at a rate of 10°C per minute, cooled, and then heated again from 25°C to 303°C at a rate of 10°C per minute, the coefficient of thermal expansion (CTE) is preferably less than 200 ppm / °C, more preferably less than 190 ppm / °C, even more preferably less than 185 ppm / °C, and practically 0 ppm / °C or more.

[0146] <<Resin Composite Sheet>> The resin composite sheet of this embodiment includes a support and a layer formed from the resin composition of this embodiment disposed on the surface of the support. The resin composite sheet can be used as a build-up film or a dry film solder resist. The resin composite sheet typically does not contain a substrate. The substrate referred to here means the substrate shown in the prepreg section described later.

[0147] Examples of supports used here include, but are not limited to, 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 these resin films, organic film substrates such as polyimide film, conductive foils such as copper foil and aluminum foil, glass plates, SUS (Steel Use Stainless) plates, and FRP (Fiber-Reinforced Plastics). One form of the resin composite sheet of this embodiment is a resin composite sheet in which a resin film is provided on one side of a layer formed from the resin composition of this embodiment and a release film is provided on the other side, or a resin composite sheet in which a release film is provided on one side of a layer formed from the resin composition of this embodiment and a metal foil (preferably copper foil) is provided on the other side.

[0148] The method for manufacturing the resin composite sheet 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 composite sheet. As for the application method (coating method), for example, one can apply the solution obtained by dissolving the resin composition of this embodiment in a solvent 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 resin composite sheet in which the support and the resin composition are laminated to obtain a single-layer sheet. Furthermore, a single-layer sheet can also be obtained without using a support by supplying the solution obtained by dissolving the resin composition of this embodiment in a solvent into a mold having a sheet-shaped cavity and drying it to form a sheet.

[0149] In the production of the single-layer sheet or resin composite sheet of this embodiment, the drying conditions for removing the solvent are not particularly limited, but since low temperatures tend to leave solvent residue in the resin composition, and high temperatures cause the resin composition to harden, a temperature of 20°C to 200°C for 1 to 90 minutes is preferred. Furthermore, the single-layer sheet or resin composite sheet 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. In addition, the thickness of the resin layer in the single-layer sheet or resin composite sheet of this embodiment can be adjusted by the concentration of the resin composition solution of this embodiment used for coating and the coating thickness, and is not particularly limited, but generally, a thickness of 0.1 to 500 μm is preferred because a thicker coating thickness tends to leave solvent residue during drying.

[0150] <<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 is 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.

[0151] 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.

[0152] <<Metal Foil Clad Laminate>> The metal foil clad laminate of this embodiment includes the prepreg of this embodiment and metal foil arranged on one or both sides of the prepreg. As a method for manufacturing the metal foil clad laminate of this embodiment, for example, one method is to arrange at least one sheet of the prepreg of this embodiment (preferably two or more sheets stacked) and arrange metal foil on one or both sides thereof and then laminate-form it. More specifically, it can be manufactured by arranging metal foil such as copper or aluminum on one or both sides of the prepreg and then laminating it. The number of prepreg sheets is preferably 1 to 10, more preferably 2 to 10, and even more preferably 2 to 9. The metal foil is not particularly limited as long as it is used as a material for printed circuit boards, but examples include copper foil such as rolled copper foil and electrolytic copper foil. The thickness of the metal foil (preferably copper foil) is not particularly limited and may be about 1.5 to 70 μm. Furthermore, when copper foil is used as the metal foil, it is preferable that the surface roughness Rz of the copper foil, measured according to JIS B0601:2013, is adjusted to 0.2 to 4.0 μm. Setting the surface roughness Rz of the copper foil to 0.2 μm or more results in an appropriate surface roughness, which tends to further improve the copper foil peel strength. On the other hand, setting the surface roughness Rz of the copper foil to 4.0 μm or less results in an appropriate surface roughness, which tends to further improve the dielectric loss tangent properties of the resulting cured product. From the viewpoint of the dielectric loss tangent properties of the resulting cured product and the copper foil peel strength, the surface roughness Rz of the copper foil is more preferably 0.5 μm or more, even more preferably 0.6 μm or more, particularly preferably 0.7 μm or more, even more preferably 3.5 μm or less, even more preferably 3.0 μm or less, and particularly preferably 2.0 μm or less.

[0153] The lamination method includes methods commonly used when forming laminates and multilayer boards for printed circuit boards. More specifically, it includes a method using a multi-stage press, multi-stage vacuum press, continuous molding machine, autoclave molding machine, etc., at a temperature of approximately 180 to 350°C, a heating time of approximately 100 to 300 minutes, and a surface pressure of approximately 1 to 10 MPa. Furthermore, a multilayer board can be made by laminating the prepreg of this embodiment with a separately manufactured inner layer wiring board. As a method for manufacturing a multilayer board, for example, copper foil of approximately 35 μm is placed on both sides of one prepreg of this embodiment, and after lamination using the above molding method, an inner layer circuit is formed, and this circuit is subjected to a blackening treatment to form an inner layer circuit board. After that, this inner layer circuit board and the prepreg of this embodiment are arranged alternately one by one, and then copper foil is placed as the outermost layer, and a multilayer board can be manufactured by lamination under the above conditions, preferably under vacuum. The metal foil-clad laminate of this embodiment can be suitably used as a printed circuit board.

[0154] The metal foil-clad laminate of this embodiment preferably has a peel strength of 0.30 kN / m or more, more preferably 0.35 kN / m or more, and even more preferably 0.50 kN / m or more, measured in accordance with the provisions of JIS C6481 5.7 "Peel Strength". There is no upper limit to the peel strength, but for example, even if it is 2.00 kN / m or less, it will sufficiently satisfy the required performance.

[0155] As described above, the resin composition for electronic materials obtained using the resin composition of this embodiment (a resin composition consisting of a combination of specific components) can have cured products that are excellent in low dielectric properties (low dielectric constant, low dielectric loss tangent, especially low dielectric constant), flame retardancy, and low warping, as well as excellent moisture absorption and heat resistance and heat resistance.

[0156] <<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 at least one of a layer formed from the resin composition of this embodiment and a layer formed from the prepreg of this embodiment. Such a printed wiring board can be manufactured according to conventional methods, and the manufacturing method is not particularly limited. An example of a method for manufacturing a printed wiring board is shown below. First, a metal foil laminate such as the copper foil laminate described above is prepared. Next, an etching treatment is performed on the surface of the metal foil laminate to form an inner layer circuit and produce an inner layer substrate. Surface treatment is performed on the inner layer circuit surface of this inner layer substrate to increase the adhesive strength as needed, and then the required number of prepregs or resin sheets described above are stacked on the inner layer circuit surface, and then metal foil for the outer layer circuit is laminated on the outside thereafter, and the substrate is heated and pressed to form an integral molded product. In this way, a multilayer laminate is produced in which an insulating layer made of a base material and a cured product of the resin composition is formed between the inner layer circuit and the metal foil for the outer layer circuit. Next, after drilling holes for through-holes and via-holes in this multilayer laminate, a plated metal film is formed on the walls of these holes to provide electrical connectivity between the inner layer circuit and the metal foil for the outer layer circuit. Furthermore, the metal foil for the outer layer circuit is etched to form the outer layer circuit, thereby manufacturing a printed circuit board.

[0157] The printed circuit board obtained in the above manufacturing example has an insulating layer and a conductive layer formed on the surface of the insulating layer, wherein the insulating layer contains the resin composition of this embodiment and / or its cured product. That is, the prepreg of this embodiment described above (for example, a prepreg formed from a substrate and the resin composition of this embodiment impregnated or coated thereon), and the layer formed from the resin composition of the metal foil laminate of this embodiment described above, become the insulating layer of this embodiment. 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.

[0158] Furthermore, it is preferable to reduce the surface roughness of the insulating layer formed from the cured resin composition of this embodiment after the roughening treatment. Specifically, the arithmetic mean roughness Ra of the surface of the insulating layer after the roughening treatment is preferably 200 nm or less, more preferably 150 nm or less, and particularly preferably 100 nm or less. The lower limit of the arithmetic mean roughness Ra is not particularly limited, but for example it may be 10 nm or more. The arithmetic mean roughness Ra of the surface of the insulating layer is measured using a non-contact surface roughness meter in VSI mode with a 50x lens. The non-contact surface roughness meter used is the WYKONT 3300 manufactured by Bee Instruments.

[0159] 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.

[0160] <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.

[0161] <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 is 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.

[0162] <<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.

[0163] Example 1 Maleimide compound (ma) having the structure shown below (manufactured by DIC Corporation, "NE-X-9470S", functional group equivalent (maleimide group equivalent) is 450 g / eq., corresponding to the compound represented by formula (M1)) 29 parts by mass, maleimide compound (BMI-70) having the structure shown below (manufactured by K.I. Chemicals, compound represented by formula (M4)) 25 parts by mass, polyphenylene ether compound (D1) having a carbon-carbon unsaturated double bond at the terminal obtained in Synthesis Example 1 above, and styrene A varnish was obtained by dissolving and mixing 20 parts by mass of a nitrate-based elastomer (1,2-SBS-P35, manufactured by Nippon Soda Co., Ltd.), 5 parts by mass of a compound represented by formula (I) (manufactured by Shikoku Chemicals Co., Ltd., flame retardant crosslinking agent 1, corresponding to the compound where m=0 in formula (I)), 0.25 parts by mass of a peroxide catalyst (perbutyl P, manufactured by NOF Corporation), and 0.25 parts by mass of an imidazole catalyst (manufactured by Shikoku Chemicals Co., Ltd., 2E4MZ (trade name)) in a mixed solvent consisting of 20 parts by mass of toluene and 5 parts by mass of methyl ethyl ketone.

[0164] Maleimide compounds (MA)

[0165] BMI-70 In the above formula, Me is a methyl group and Et is an ethyl group.

[0166] <Preparation of 0.8 mm thick cured plate test specimens> Mixed resin powder was obtained by evaporating the solvent from the obtained varnish. The mixed resin powder was filled into a mold with sides of 100 mm and a thickness of 0.8 mm, and 12 μm copper foil (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both sides, and a pressure of 30 kg / cm² was applied. ２ Then, a vacuum press was performed at a temperature of 220°C for 120 minutes to obtain a hardened plate with sides of 100 mm and a thickness of 0.8 mm.

[0167] <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. In Table 1 below, samples with a Dk (relative permittivity) of less than 2.4 are indicated as "A," and samples with a Dk (relative permittivity) of 2.4 or more are indicated as "B." For Df (dielectric loss tangent), samples with a Dk (relative permittivity) of less than 0.0016 are indicated as "A," and samples with a Df (dielectric loss tangent) of 0.0016 or more are indicated as "B."

[0168] <Glass Transition Temperature> After removing the copper foil from the obtained 0.8 mm thick hardened plate by etching, it was downsized to 10 mm x 30 mm to obtain an evaluation sample. The obtained evaluation sample was dried at 120°C for 60 minutes, and then measured using the DMA (Dynamic Mechanical Analysis) bending method with a dynamic viscoelastic analyzer in accordance with JIS C6481 5.17.2. The glass transition temperature (Tg) was estimated from the obtained tanδ chart. A dynamic viscoelastic analyzer manufactured by TA Instruments was used. In Table 1, glass transition temperatures of 200°C or higher are indicated as "A", and those below 200°C are indicated as "B".

[0169] <Coefficient of linear 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 25°C to 303°C at a rate of 10°C per minute using a thermomechanical analyzer (manufactured by TA Instruments), cooled, and then heated again from 25°C to 303°C at a rate of 10°C per minute to measure the coefficient of thermal expansion (ppm / °C) from 60 to 120°C. ppm represents a volume ratio. For further details, please refer to JIS C 6481 5.19 above. In Table 1, glass transition temperatures are indicated as "A" for temperatures below 200 ppm / °C and "B" for temperatures of 200 ppm / °C or higher.

[0170] <<Flame Retardancy>> The resin composition was applied to a 25 μm thick polyimide film using a bar coater so that the dried coating film was 50 ± 5 μm thick, and toluene was removed by distillation until a constant weight was reached. Next, the film was staged in B-stage by treatment at 150°C for 30 minutes, and then laminated onto a 400 μm thick FR-4 grade glass epoxy substrate etched with copper foil using a vacuum laminator. An evaluation film was then prepared by heat treatment at 190°C for 1 hour. The flame retardancy of this evaluation sample was evaluated according to the UL94V test method of the US UL standard vertical combustion test. In Table 1, "A" indicates that the flame retardancy satisfies V-1, and "B" indicates that it does not satisfy V-1.

[0171] Example 2 The procedure was carried out in the same manner as in Example 1, except that the content of the maleimide compound (ma) was changed to 24 parts by mass and the content of the compound represented by formula (I) was changed to 10 parts by mass.

[0172] Example 3 The procedure was carried out in the same manner as in Example 1, except that the content of the maleimide compound (ma) was changed to 19 parts by mass and the content of the compound represented by formula (I) was changed to 15 parts by mass.

[0173] Comparative Example 1 The procedure was carried out in the same manner as in Example 1, except that the compound represented by formula (I) was replaced with an equal amount of the condensed phosphate ester compound shown below (PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.). PX-200

[0174] Comparative Example 2 The procedure was carried out in the same manner as in Example 1, except that the content of the maleimide compound (ma) was changed to 24 parts by mass, PX-200 was used instead of the compound represented by formula (I), and the content of PX-200 was changed to 10 parts by mass.

[0175] Comparative Example 3 The procedure was carried out in the same manner as in Example 1, except that the content of the maleimide compound (ma) was changed to 19 parts by mass, PX-200 was used instead of the compound represented by formula (I), and the content of PX-200 was changed to 15 parts by mass.

[0176] Comparative Example 4 The procedure was carried out in the same manner as in Example 1, except that the maleimide compound (ma) was not used and the content of MBI-70 was changed to 54 parts by mass.

[0177] Comparative Example 5 The procedure was carried out in the same manner as in Example 1, except that the maleimide compound (ma) was not used, the content of MBI-70 was changed to 54 parts by mass, and the compound represented by formula (I) was changed to an equal amount of PX-200.

[0178] Comparative Example 6 The procedure was carried out in the same manner as in Example 1, except that the content of the polyphenylene ether compound (D1) was changed to 26 parts by mass and the compound represented by formula (I) was not included.

[0179] Comparative Example 7 The procedure was carried out in the same manner as in Example 1, except that the content of the polyphenylene ether compound (D1) was changed to 25 parts by mass and the content of the compound represented by formula (I) was changed to 1 part by mass.

[0180]

[0181] 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

1. A resin composition comprising a compound (A) represented by formula (I) and a thermosetting compound (B), wherein the thermosetting compound (B) contains a compound represented by formula (M1), and the content of the compound (A) is 2 to 20 parts by mass with respect to 100 parts by mass of the resin solid content in the resin composition. (In formula (I), each R independently represents an alkyl group having 1 to 10 carbon atoms, and each m independently represents an integer of 0 to 4. m independently represents an integer of 0 to 4.) (In formula (M1), R Ｍ１ 、R Ｍ２ 、R Ｍ３ 、and R Ｍ４ each independently represents a hydrogen atom or an organic group. R Ｍ５ and R Ｍ６ each independently represents a hydrogen atom or an alkyl group. Ar Ｍ represents a divalent aromatic group. A is an alicyclic group having 4 to 6 members. R Ｍ７ and R Ｍ８ each independently represents an alkyl group. mx is 1 or 2, and lx is 0 or 1. R Ｍ９ and R Ｍ１０ each independently represents a hydrogen atom or an alkyl group. R Ｍ１１ 、R Ｍ１２ 、R Ｍ１３ 、and R Ｍ１４ each independently represents a hydrogen atom or an organic group. R Ｍ１５ each independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, 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.) 2. The resin composition according to claim 1, wherein the phosphorus content in compound (A) is 2 to 15% by mass.

3. The resin composition according to claim 1 or 2, further comprising a styrene-based elastomer.

4. The resin composition according to claim 1 or 2, wherein the thermosetting compound (B) comprises at least one selected from the group consisting of maleimide compounds other than the compound represented by formula (M1), aromatic resins having a carbon-carbon double bond at the terminal, 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 compounds having a vinylene group.

5. The resin composition according to claim 1 or 2, wherein the thermosetting compound (B) comprises a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus.

6. The resin composition according to claim 1 or 2, further comprising a peroxide catalyst.

7. The resin composition according to claim 1, wherein the phosphorus content in compound (A) is 2 to 15% by mass, further comprising a styrene-based elastomer, the thermosetting compound (B) comprising a polyphenylene ether compound having a carbon-carbon unsaturated double bond at its terminus, and further comprising a peroxide catalyst.

8. The resin composition according to claim 1, 2, or 7, wherein m is 0 in compound (A) represented by formula (I).

9. A cured product of the resin composition according to any one of claims 1, 2, and 7.

10. A resin composite sheet comprising a support and a layer formed from the resin composition according to any one of claims 1, 2, and 7, disposed on the surface of the support.

11. A prepreg formed from a substrate and a resin composition according to any one of claims 1, 2, and 7.

12. A metal foil-clad laminate comprising at least one prepreg according to claim 11 and a metal foil disposed on one or both sides of the prepreg.

13. A printed circuit board comprising an insulating layer and a conductive 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 7.

14. A semiconductor device including a printed circuit board as described in claim 13.

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