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

Abstract

The present invention provides a resin composition, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device. Provided is a resin composition comprising hollow silica (A) and a thermosetting resin (B), wherein the content of the hollow silica (A) in the resin composition is 10-250 parts by mass with respect to 100 parts by mass of resin solid content, and the dielectric loss tangent of a cured product of the resin composition at a frequency of 10 GHz as measured in accordance with a cavity resonator perturbation method is not more than 0.0025.

Description

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

[0001] The present invention relates to a resin composition, a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.

[0002] In recent years, the integration and miniaturization of semiconductor elements used in mobile terminals, electronic devices, communication devices, and other devices has accelerated. This has led to a demand for technologies that enable high-density packaging of semiconductor elements, and improvements are also being sought in printed wiring boards, which play an important role in this process. Meanwhile, the applications of electronic devices and other devices have continued to diversify and expand. Accordingly, the properties required of printed wiring boards and the metal foil-clad laminates and prepregs used therein have become more diverse and stricter. Taking these required properties into account, various materials and processing methods have been proposed to obtain improved printed wiring boards. One example is the development of improved resin materials that make up prepregs and resin composite sheets.

[0003] For example, Patent Document 1 discloses a resin composition containing a thermosetting resin (A) and a filler (B), wherein the filler (B) contains hollow particles (b) having 1 to 10 bubbles therein and having an average particle diameter of 0.01 to 10 μm.

[0004] International Publication No. 2019 / 230661

[0005] Although the cured product of the resin composition described in Patent Document 1 has low dielectric constant and excellent appearance after curing, there is a demand for a resin composition that allows for higher-density processing of printed wiring boards in line with the trend toward higher-density packaging of semiconductor elements. The present invention aims to solve this problem by providing a resin composition that can provide a cured product that has excellent low dielectric properties (Dk and / or Df), excellent appearance after curing, and is easy to process at high density, as well as a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.

[0006] As a result of investigations conducted by the present inventors to address the above-mentioned problems, it was found that the above-mentioned problems can be solved by adjusting the content of hollow silica and adjusting the dielectric loss tangent of a cured product of a resin composition. Specifically, the above-mentioned problems were solved by the following means. <1> A resin composition comprising hollow silica (A) and a thermosetting resin (B), wherein the content of the hollow silica (A) in the resin composition is 10 to 250 parts by mass per 100 parts by mass of resin solids, and the resin composition is impregnated into an NE glass cloth so that the content of the resin composition is 70% by volume, and the cloth is heated and dried at 155°C for 5 minutes to obtain a copper foil-clad laminate. Eight prepregs each having a thickness of 0.1 mm are stacked, and 12 μm-thick electrolytic copper foils are placed on both sides of the laminate and pressed to obtain a copper foil-clad laminate. The copper foils on both sides are then removed by etching to obtain a 0.8 mm-thick sample. The dielectric loss tangent at a frequency of 10 GHz measured by a cavity resonator perturbation method in accordance with JIS C218:2007 is 0.0025 or less. <2> The resin composition according to <1>, wherein the 0.8 mm thick sample has a relative dielectric constant of 3.0 or less at a frequency of 10 GHz as measured by a cavity resonator perturbation method in accordance with JIS C218: 2007. <3> The resin composition according to <1>, wherein the resin composition is impregnated into an NE glass cloth so that the resin composition content is 70 volume %, and the prepreg is heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. 12 μm thick electrolytic copper foils are placed on both sides of the prepreg, and the prepreg is pressed to obtain a copper foil-clad laminate. The copper foils on both sides are removed by etching, and the resulting sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. When the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C, the thermal expansion coefficient in the in-plane direction at 60 to 120°C is 10 ppm / °C or less.<4> The resin composition according to <1>, wherein the 0.8 mm thick sample has a relative dielectric constant of 3.0 or less at a frequency of 10 GHz as measured by a cavity resonator perturbation method in accordance with JIS C218:2007, and the resin composition is impregnated into an NE glass cloth so that the resin composition content is 70% by volume, and the prepreg is heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. 12 μm thick electrolytic copper foils are placed on both sides of the prepreg and pressed to obtain a copper foil-clad laminate. The copper foils on both sides are removed by etching, and the resulting sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. When the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C, the thermal expansion coefficient in the plane direction at 60 to 120°C is 10 ppm / °C or less. <5> The resin composition according to any one of <1> to <4>, wherein the thermosetting resin (B) comprises an aromatic vinyl resin (D) and a maleimide compound (E). <6> The resin composition according to any one of <1> to <5>, further comprising a thermoplastic elastomer (C). <7> The resin composition according to <6>, wherein the thermoplastic elastomer (C) comprises a styrene compound unit and one or more units selected from the group consisting of a butadiene unit, an isoprene unit, a hydrogenated butadiene unit, and a hydrogenated isoprene unit, and wherein the content of the styrene compound unit in the thermoplastic elastomer (C) is 55 mass% or less of the total thermoplastic elastomer (C). <8> The resin composition according to <6> or <7>, wherein the content of the thermoplastic elastomer (C) in the resin composition is 5 to 30 mass parts per 100 mass parts of resin solids. <9> The resin composition according to any one of <5> to <8>, wherein the aromatic vinyl resin (D) includes one or more compounds selected from the group consisting of a polymer having a structural unit represented by formula (V) and a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond: (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.) <10> The resin composition according to <9>, wherein the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond includes a polyphenylene ether compound represented by formula (OP): (In formula (OP), X represents an aromatic group, and —(Y—O) ｎ１- represents a polyphenylene ether structure, n1 represents an integer of 1 to 100, and n2 represents an integer of 1 to 4. Rx is a group represented by formula (Rx-1). (In formula (Rx-1), R １ , R ２ , and R ３ each independently represent a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * represents a bonding site with an oxygen atom. Each Mc independently represents a hydrocarbon group having 1 to 12 carbon atoms. z represents an integer of 0 to 4. r represents an integer of 0 to 6.) <11> The resin composition according to any one of <5> to <10>, wherein the content of the aromatic vinyl resin (D) in the resin composition is 5 to 95 parts by mass per 100 parts by mass of resin solid content. <12> The resin composition according to any one of <5> to <11>, wherein the maleimide compound (E) includes one or more selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M3), and a compound represented by formula (M5). (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ R each independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ each independently represents a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4- to 6-membered alicyclic group. 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 R each independently represents a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ R each independently represents a hydrogen atom or an organic group. 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. px represents an integer of 0 to 3. nx represents an integer of 1 to 20. (In formula (M3), R ５５ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; n ５ represents an integer of 1 or more and 10 or less.) (In formula (M5), R ５８ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R ５９ each independently represents a hydrogen atom or a methyl group; n ６represents an integer of 1 or more. <13> The 0.8 mm thick sample has a relative dielectric constant of 3.0 or less at a frequency of 10 GHz measured by a cavity resonator perturbation method in accordance with JIS C218:2007, and the resin composition is impregnated into an NE glass cloth so that the resin composition content is 70% by volume, and the resulting prepreg is heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. Electrodeposited copper foils of 12 μm thick are placed on both sides of the prepreg and pressed to obtain a copper foil-clad laminate. The copper foils on both sides are removed by etching from the laminate, and the resulting sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. When the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C, the thermal expansion coefficient in the plane direction at 60 to 120°C is 10 ppm / °C or less, and the thermosetting resin (B) contains an aromatic vinyl resin (D) and a maleimide compound (E), and further contains a thermoplastic elastomer (C), the thermoplastic elastomer (C) comprises a styrene compound unit and one or more selected from the group consisting of a butadiene unit, an isoprene unit, a hydrogenated butadiene unit, and a hydrogenated isoprene unit, the content of the styrene compound unit in the thermoplastic elastomer (C) is 55 mass% or less of the entire thermoplastic elastomer (C), the content of the thermoplastic elastomer (C) in the resin composition is 5 to 30 mass parts per 100 mass parts of resin solid content, the aromatic vinyl resin (D) comprises one or more selected from the group consisting of a polymer having a structural unit represented by formula (V) and a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond comprises a polyphenylene ether compound represented by formula (OP), the content of the aromatic vinyl resin (D) in the resin composition is 5 to 95 mass parts per 100 mass parts of resin solid content, <13> The resin composition according to any one of <1> to <12>, wherein the maleimide compound (E) includes one or more selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M3), and a compound represented by formula (M5). (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.) (In formula (OP), X represents an aromatic group, and —(Y—O) ｎ１ - represents a polyphenylene ether structure, n1 represents an integer of 1 to 100, and n2 represents an integer of 1 to 4. Rx is a group represented by formula (Rx-1). (In formula (Rx-1), R １ , R ２ , and R ３ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * represents a bonding site with an oxygen atom. Each Mc independently represents a hydrocarbon group having 1 to 12 carbon atoms. z represents an integer of 0 to 4. r represents an integer of 0 to 6. (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ R each independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ each independently represents a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4- to 6-membered alicyclic group. 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 R each independently represents a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ R each independently represents a hydrogen atom or an organic group. 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. (In formula (M3), R ５５ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; n ５represents an integer of 1 or more and 10 or less.) (In formula (M5), R ５８ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R ５９ each independently represents a hydrogen atom or a methyl group; n ６ represents an integer of 1 or more.) <14> The resin composition according to any one of <1> to <13>, further comprising a flame retardant. <15> The resin composition according to <14>, wherein the flame retardant comprises a phosphorus-based flame retardant. <16> A cured product of the resin composition according to any one of <1> to <15>. <17> A prepreg formed from a substrate and the resin composition according to any one of <1> to <15>. <18> A metal foil-clad laminate comprising at least one prepreg according to <17> and a metal foil disposed on one or both sides of the prepreg. <19> A resin composite sheet comprising a support and a layer formed on a surface of the support from the resin composition according to any one of <1> to <15>. <20> A printed wiring board comprising an insulating layer and a conductor layer disposed on the surface of the insulating layer, wherein the insulating layer comprises a layer formed from the resin composition according to any one of <1> to <15>. <21> A semiconductor device including the printed wiring board according to <20>.

[0007] The resin composition can provide a cured product that has excellent low dielectric properties (Dk and / or Df), excellent appearance after curing, and is easy to process into high density. It is also possible to provide a cured product, a prepreg, a metal foil-clad laminate, a resin composite sheet, a printed wiring board, and a semiconductor device.

[0008] Hereinafter, a detailed description will be given of an embodiment of the present invention (hereinafter simply referred to as "the present embodiment"). Note that the following present embodiment is an example for explaining the present invention, and the present invention is not limited to this embodiment. In this specification, the term "to" is used to mean that the numerical values ​​before and after it are included as lower and upper limits. In this specification, various physical property values ​​and characteristic values ​​are those at 23°C unless otherwise specified. In the description of a group (atomic group), a notation that does not indicate substituted or unsubstituted encompasses both a group (atomic group) that has no substituent and a group (atomic group) that has a substituent. For example, the term "alkyl group" encompasses not only an alkyl group that has no substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group). In this specification, when a notation that does not indicate substituted or unsubstituted is used, unsubstituted is preferred.

[0009] In this specification, the term "(meth)allyl group" refers to either or both of allyl and methallyl, "(meth)acrylate" refers to either or both of acrylate and methacrylate, "(meth)acrylic" refers to either or both of acrylic and methacrylic, and "(meth)acryloyl" refers to either or both of acryloyl and methacryloyl. In this specification, the term "process" refers not only to an independent process, but also to a process that cannot be clearly distinguished from other processes, as long as the intended effect of the process is achieved. If the measurement methods, etc. described in the standards shown in this specification vary from year to year, they shall be based on the standards as of January 1, 2023, unless otherwise specified.

[0010] In this specification, the resin solid content refers to components excluding hollow silica (A), fillers (solid silica, porous silica, other fillers), and solvents, and is intended to include the thermosetting resin (B), other components blended as necessary, and resin additive components (additives such as curing accelerators and flame retardants). In this specification, the terms relative permittivity and dielectric constant are used interchangeably.

[0011] The resin composition of this embodiment is a resin composition containing hollow silica (A) and a thermosetting resin (B), wherein the content of the hollow silica in the resin composition is 10 to 250 parts by mass per 100 parts by mass of resin solids. The resin composition is impregnated into NE glass cloth so that the resin composition content is 70% by volume, and then heated and dried at 155°C for 5 minutes to obtain 0.1 mm thick prepregs. Eight 0.1 mm thick prepregs are stacked, and 12 μm thick electrolytic copper foils are placed on both sides and pressed to obtain a copper foil-clad laminate. The copper foils on both sides are then removed by etching. The resulting 0.8 mm thick sample has a dielectric loss tangent of 0.0025 or less at a frequency of 10 GHz, measured by a cavity resonator perturbation method in accordance with JIS C218:2007. This configuration allows the resulting cured product to have excellent low dielectric properties (Dk and / or Df), excellent appearance after curing, and can be easily processed to high density. In this embodiment, the use of hollow silica (A) reduces the dielectric constant of the resulting cured product. This is because, in this embodiment, there is a higher probability that hollow silica particles containing air-filled or vacuum spaces remain in the cured product. Furthermore, since gases such as air and vacuum spaces have low dielectric constants, the dielectric constant of the cured product of the resin composition can be reduced. Furthermore, in this embodiment, the appearance of the resulting cured product can be improved by adjusting the content of hollow silica (A). Furthermore, the resin composition of this embodiment uses hollow silica (A), which makes high-density processing of printed wiring boards easier. This is presumably because hollow silica (A) acts similarly to a lubricant in the cured product, making it easier to align with the setting position of the drill used for high-density processing. Details of this embodiment will be described below.

[0012] <Hollow Silica (A)> The resin composition of this embodiment contains hollow silica (A). By including hollow silica (A), the low dielectric properties (Dk and / or Df) of the resulting cured product are improved. Furthermore, drilling processability is also improved. Hollow silica (A) is a particle having one or more, usually 10 or less, spaces inside an inorganic outer shell, and typically has 1 to 3 spaces inside the inorganic outer shell. The spaces are typically filled with vacuum or air. By including spaces not filled with silica inside the silica particles in this way, the low dielectric properties (Dk and / or Df) of the resulting cured product are improved. Note that hollow silica is different from mesoporous silica and porous silica.

[0013] The hollow silica (A) is a material containing silica as a main component, and may contain, in addition to silica, inorganic oxides such as alumina, zirconia, titania, etc. The content of silica in the hollow silica particles (A) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, and even more preferably 95% by mass or more, and may be 100% by mass or less.

[0014] From the viewpoint of improving the appearance of the cured product, the hollow silica (A) preferably has a volume average particle diameter (D50) in the range of 0.1 to 10 μm. The lower limit of the volume average particle diameter is more preferably 0.5 μm or more, even more preferably 1.0 μm or more, even more preferably 1.5 μm or more, and may even be 1.8 μm or more, or 2.0 μm or more. The upper limit of the volume average particle diameter is more preferably 5.0 μm or less, even more preferably 4.7 μm or less, and even more preferably 4.5 μm or less. The volume average particle diameter (D50) of the hollow silica (A) can be measured by a laser diffraction / scattering method, specifically, by the method described in the Examples. Furthermore, in this embodiment, the content of particles having a particle diameter of more than 8.0 μm in the hollow silica (A) is preferably 10 vol% or less, more preferably 5 vol% or less, and even more preferably 1 vol% or less.

[0015] The porosity of the hollow silica (A) is preferably 5 to 80% by volume from the viewpoint of low dielectric properties and particle strength. The lower limit of the porosity is more preferably 8% by volume or more, and even more preferably 10% by volume or more. The upper limit of the porosity is more preferably 50% by volume or less, even more preferably 35% by volume or less, even more preferably 25% by volume or less, and even more preferably 20% by volume or less. Such a porosity not only provides excellent low dielectric properties (low dielectric constant and / or low dielectric dissipation factor), but also maintains particle strength at a predetermined level or higher, effectively suppressing particle cracking. The porosity of the hollow silica (A) can be calculated from the particle density, specifically by the method described in the Examples.

[0016] In addition, the hollow silica (A) may also be those described in paragraphs 0008 to 0047 of Japanese Patent No. 7320692 and paragraphs 0012 to 0021 of International Publication No. 2022 / 145350, the contents of which are incorporated herein by reference.

[0017] The content of hollow silica (A) in the resin composition of this embodiment is 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, even more preferably 50 parts by mass or more, even more preferably 75 parts by mass or more, even more preferably 80 parts by mass or more, and 250 parts by mass or less, preferably 230 parts by mass or less, more preferably 210 parts by mass or less, even more preferably 190 parts by mass or less, even more preferably 150 parts by mass or less, even more preferably 130 parts by mass or less, per 100 parts by mass of resin solids. By setting the content of hollow silica (A) to the above lower limit or more, low thermal expansion, low dielectric properties, heat resistance, and drilling processability tend to be further improved. Furthermore, by setting the content of hollow silica (A) to the above upper limit or less, the appearance and moldability after curing tend to be further improved. The resin composition of this embodiment may contain only one type of hollow silica (A), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0018] The resin composition of this embodiment may or may not contain solid silica (silica that does not contain the voids in the hollow silica). Preferably, the resin composition of this embodiment is substantially free of solid silica. "Substantially free" means that the content of solid silica contained in the resin composition is less than 10% by mass of the content of hollow silica contained in the resin composition, preferably less than 5% by mass, more preferably less than 3% by mass, and even more preferably less than 1% by mass.

[0019] The resin composition of this embodiment may or may not contain porous silica. Preferably, the resin composition of this embodiment is substantially free of porous silica. "Substantially free" means that the content of porous silica contained in the resin composition is less than 10% by mass of the content of hollow silica contained in the resin composition, preferably less than 5% by mass, more preferably less than 3% by mass, and even more preferably less than 1% by mass.

[0020] <Thermosetting Resin (B)> The resin composition of this embodiment includes a thermosetting resin (B). The type of thermosetting resin (B) is not particularly limited, but it preferably includes at least one selected from the group consisting of an aromatic vinyl resin (D), a maleimide compound (E), a cyanate ester compound, a (meth)allyl compound, a (meth)acrylate compound, an epoxy compound, a phenol compound, an oxetane resin, a benzoxazine compound, an arylcyclobutene compound, a perfluorovinyl ether resin, a polyimide compound, and a compound having a vinylene group, more preferably includes at least one selected from the group consisting of an aromatic vinyl resin (D), a maleimide compound (E), and a cyanate ester compound, and even more preferably includes both an aromatic vinyl resin (D) and a maleimide compound (E).

[0021] The content of the thermosetting resin (B) in the resin composition of this embodiment is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, even more preferably 30 parts by mass or more, even more preferably 40 parts by mass or more, even more preferably 50 parts by mass or more, and preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less, per 100 parts by mass of the resin solids. By setting the content of the thermosetting resin (B) to the above lower limit or more, heat resistance tends to be further improved. Furthermore, by setting the content of the thermosetting resin (B) to the above upper limit or less, low thermal expansion tends to be further improved. The resin composition of this embodiment may contain only one type of thermosetting resin (B), or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0022] A first embodiment of the thermosetting resin (B) comprises an aromatic vinyl resin (D) and a maleimide compound (E). In the first embodiment of the thermosetting resin (B), the content of the maleimide compound (E) is preferably 50 parts by mass or more, more preferably 80 parts by mass or more, even more preferably 100 parts by mass or more, and even more preferably 120 parts by mass or more, and is preferably 200 parts by mass or less, and more preferably 180 parts by mass or less, relative to 100 parts by mass of the aromatic vinyl resin (D).

[0023] A second embodiment of the thermosetting resin (B) is the first embodiment, further comprising a cyanate ester compound. In the second embodiment of the thermosetting resin (B), the content of the cyanate ester compound is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 50 parts by mass or less, more preferably 30 parts by mass or less, per 100 parts by mass of the aromatic vinyl resin (D). By setting the content of the cyanate ester compound to the above-mentioned lower limit or more, the heat resistance of the resulting resin tends to be further improved. By setting the content of the cyanate ester compound to the above-mentioned upper limit or less, the low dielectric properties (Dk and / or Df) of the resulting cured product tends to be further improved.

[0024] <<Aromatic Vinyl Resin (D)>> The aromatic vinyl resin (D) is, for example, a compound having a vinylaryl group, and is a compound that cures when heated. By using the aromatic vinyl resin (D) in combination with a thermoplastic elastomer (C) (particularly a styrene-based elastomer), the compatibility between the two is improved, and the thermal expansion coefficient of the resulting cured product can be made smaller. Specifically, the aromatic vinyl resin (D) preferably contains one or more compounds selected from the group consisting of a polymer having a structural unit represented by formula (V) and a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, and more preferably contains a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond.

[0025] When the resin composition of this embodiment contains an aromatic vinyl resin (D), the content thereof 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, and even more preferably 20 parts by mass or more, per 100 parts by mass of the resin solids. Depending on the application, it is even more preferable that it is 30 parts by mass or more, and it is preferably 95 parts by mass or less, more preferably 80 parts by mass or less, and even more preferably 70 parts by mass or less. Depending on the application, it is even more preferable that it is 55 parts by mass or less, and even more preferably 50 parts by mass or less. By setting the content of the aromatic vinyl resin (D) to the above lower limit or more, compatibility and heat resistance tend to be further improved. Furthermore, by setting the content of the aromatic vinyl resin (D) to the above upper limit or less, low thermal expansion tends to be further improved. The resin composition of this embodiment may contain only one type of aromatic vinyl resin (D), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range.

[0026] <<<Polymer Having a Structural Unit Represented by Formula (V)>>> The resin composition of the present embodiment may contain a polymer having a structural unit represented by formula (V). By containing a polymer having a structural unit represented by formula (V), a resin composition with excellent low dielectric properties (low relative dielectric constant, low dielectric loss tangent) can be obtained. (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.) The aromatic hydrocarbon linking group may be a group consisting only of aromatic hydrocarbons which may have a substituent, or a group consisting of a combination of aromatic hydrocarbons which may have a substituent and other linking groups, and is preferably a group consisting only of aromatic hydrocarbons which may have a substituent. Examples of the substituent that the aromatic hydrocarbon may have include the substituent Z (e.g., an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, an alkynyl group having 2 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a hydroxy group, an amino group, a carboxy group, a halogen atom, etc.). It is also preferable that the aromatic hydrocarbon does not have a substituent. The aromatic hydrocarbon linking group is usually a divalent linking group.

[0027] Specific examples of the aromatic hydrocarbon linking group include a phenylene group, a naphthalenediyl group, an anthracenediyl group, a phenanthrenediyl group, a biphenyldiyl group, and a fluorenediyl group, each of which may have a substituent, and among these, a phenylene group which may have a substituent is preferred. Examples of the substituent include the above-mentioned substituent Z, but it is preferable that the above-mentioned phenylene group and other groups do not have a substituent.

[0028] It is more preferable that the polymer having a structural unit represented by formula (V) contains at least one of a structural unit represented by formula (V1) below, a structural unit represented by formula (V2) below, and a structural unit represented by formula (V3) below. In the formulas below, * represents a bonding position. Furthermore, hereinafter, the structural units represented by formulas (V1) to (V3) may be collectively referred to as "structural unit (a)."

[0029] In formulas (V1) to (V3), L １is an aromatic hydrocarbon linking group (preferably having 6 to 22 carbon atoms, more preferably 6 to 18 carbon atoms, and even more preferably 6 to 10 carbon atoms). Specific examples include phenylene groups, naphthalenediyl groups, anthracenediyl groups, phenanthrenediyl groups, biphenyldiyl groups, and fluorenediyl groups, each of which may have a substituent. Of these, phenylene groups, which may have a substituent, are preferred. Examples of the substituent include the aforementioned substituent Z, but it is preferable that the aforementioned groups, such as the phenylene group, be unsubstituted. The compound forming the structural unit (a) is preferably a divinyl aromatic compound, such as divinylbenzene, bis(1-methylvinyl)benzene, divinylnaphthalene, divinylanthracene, divinylbiphenyl, and divinylphenanthrene. Of these, divinylbenzene is particularly preferred. These divinyl aromatic compounds may be used alone, or two or more types may be used as necessary. That is, the structural unit (a) is preferably a structural unit derived from a divinyl aromatic compound.

[0030] As mentioned above, the polymer having the structural unit represented by formula (V) may be a homopolymer of the compound forming the structural unit (a), but may also be a copolymer with a structural unit derived from another monomer.When the polymer having the structural unit represented by formula (V) is a copolymer, its copolymerization ratio is preferably 3 mol% or more of the structural unit (a), more preferably 5 mol% or more, even more preferably 10 mol% or more, and may even 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, particularly more preferably 30 mol% or less, and may even be 25 mol% or less, 20 mol% or less.

[0031] An example of a structural unit derived from another monomer is a structural unit (b) derived from an aromatic compound having one vinyl group (monovinyl aromatic compound).

[0032] The structural unit (b) derived from a monovinyl aromatic compound is preferably a structural unit represented by the following formula (V4).

[0033] In formula (V4), L ２ is an aromatic hydrocarbon linking group, and preferred examples thereof include the above L １ Examples include the following. * indicates the bonding position. R Ｖ１ is a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms (preferably an alkyl group). Ｖ１ When R is a hydrocarbon group, it preferably has 1 to 6 carbon atoms, more preferably 1 to 3 carbon atoms. Ｖ１ and L ２ may have the above-mentioned substituent Z.

[0034] When the polymer having a structural unit represented by formula (V) is a copolymer containing a structural unit (b) derived from a monovinyl aromatic compound, examples of the monovinyl aromatic compound 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 aforementioned substituent Z. Furthermore, these monovinyl aromatic compounds may be used alone or in combination with two or more. Among these, the structural unit (b) preferably contains a structural unit derived from at least one selected from the group consisting of o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene. It is more preferable that the structural unit (b) further contains a structural unit derived from styrene in addition to a structural unit derived from at least one selected from the group consisting of o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene.

[0035] When the polymer having the structural unit represented by formula (V) is a copolymer containing the structural unit (b), the copolymerization ratio of the structural unit (b) is preferably 10 mol% or more, more preferably 15 mol% or more, and may further 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.

[0036] A polymer having a structural unit represented by formula (V) may have structural units other than the structural unit (a) and the structural unit (b). Examples of such structural units include structural unit (c) derived from a cycloolefin compound. Examples of cycloolefin compounds include hydrocarbons having a double bond within the ring structure. Specific examples include monocyclic 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 having condensed aromatic rings such as indene and acenaphthylene. Examples of norbornene compounds include those described in paragraphs 0037 to 0043 of JP 2018-039995 A, the contents of which are incorporated herein by reference. The cycloolefin compounds exemplified here may further have the aforementioned substituent Z.

[0037] When the polymer having the structural unit represented by formula (V) is a copolymer containing the structural unit (c), the copolymerization ratio of the 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, and even more preferably 70 mol% or less, and may be 50 mol% or less, or may be 30 mol% or less.

[0038] A polymer having a structural unit represented by formula (V) may further incorporate a 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. Specific 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), and isoprene. The copolymerization ratio of the structural unit (d) derived from other polymerizable compounds is preferably 30 mol% or less, more preferably 20 mol% or less, and even more preferably 10 mol% or less.

[0039] An example of an embodiment of a polymer having a structural unit represented by formula (V) is a polymer that essentially contains the structural unit (a) and contains at least one of the structural units (b) to (d). Further examples include polymers in which the total of the structural units (a) to (d) accounts for 95 mol% or more, and even 98 mol% or more, of all structural units. Another embodiment of a polymer having a structural unit represented by formula (V) is a polymer that essentially contains the structural unit (a), and in which, of all structural units excluding the terminals, structural units containing aromatic rings account for preferably 90 mol% or more, more preferably 95 mol% or more, and even 100 mol%. Note that, when calculating the mol% per total structural units, one structural unit is considered to be derived from one molecule of a monomer (e.g., a divinyl aromatic compound, a monovinyl aromatic compound, etc.) used in the production of a polymer having a structural unit represented by formula (V).

[0040] The method for producing a polymer having a structural unit represented by formula (V) is not particularly limited and may be a conventional method, but examples thereof include polymerizing a raw material containing a divinyl aromatic compound (optionally in the presence of a monovinyl aromatic compound, a cycloolefin compound, etc.) in the presence of a Lewis acid catalyst. The Lewis acid catalyst may be a metal fluoride such as boron trifluoride or a complex thereof.

[0041] The structure of the chain end of the polymer having the structural unit represented by formula (V) is not particularly limited, but in terms of the group derived from the divinyl aromatic compound, it may have a structure represented by the following formula (E1). １ is the same as defined in the above formula (V1). * represents the bonding position. *-CH=CH-L １ -CH=CH ２ (E1)

[0042] When a group derived from a monovinyl aromatic compound is at the chain end, the structure may be that of the following formula (E2): ２ and R Ｖ１ are the same as defined in the formula (V4). * represents a bonding position. *-CH=CH-L ２ -R Ｖ１ (E2)

[0043] The molecular weight of the polymer having the structural 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 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 be 30,000 or less, 10,000 or less, or 5,000 or less. The molecular weight of the polymer having the structural 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 weight average molecular weight (Mw). By setting the weight average molecular weight to the above lower limit, the excellent low dielectric properties of the polymer having the structural unit represented by formula (V), particularly Df and dielectric properties after moisture absorption, can be effectively exhibited in the cured product of the resin composition. The upper limit of the weight-average molecular weight Mw is preferably 130,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less, and even more preferably 50,000 or less. By setting the weight-average molecular weight to the above upper limit or less, poor embedding tends to be less likely when the prepreg or resin sheet is laminated on a circuit-forming substrate. 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 be 15 or less, or even 12 or less. As for the lower limit, a practical value is 1.1 or more, preferably 2.0 or more, more preferably 4 or more, even more preferably 5 or more, even more preferably 7 or more, and even more preferably 8 or more. The Mw and Mn are measured according to the description in the Examples below. When the resin composition of the present embodiment contains two or more polymers having a structural unit represented by formula (V), it is preferable that the Mw, Mn and Mw / Mn of the mixture satisfy the above ranges.

[0044] The vinyl group equivalent of the polymer having a structural 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. The vinyl group equivalent is preferably 1200 g / eq. or less, more preferably 1000 g / eq. or less, and may further 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 vinyl group equivalent is above the lower limit, the storage stability of the resin composition is improved and the fluidity of the resin composition tends to be improved. Therefore, moldability is improved, voids are less likely to occur when forming a prepreg, etc., and a more reliable printed wiring board tends to be obtained. On the other hand, when the vinyl group equivalent is equal to or less than the upper limit, the heat resistance of the resulting cured product tends to be improved.

[0045] The cured product of a polymer having a structural unit represented by formula (V) preferably has excellent low dielectric properties. For example, the cured product of the polymer having the structural unit represented by formula (V) used in this embodiment preferably has a relative dielectric constant (Dk) 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, at 10 GHz, measured according to a cavity resonator perturbation method. Furthermore, a practical lower limit of the relative dielectric constant is, for example, 1.80 or more. Furthermore, the cured product of the polymer having the structural unit represented by formula (V) preferably has a dielectric loss tangent (Df) of 0.0030 or less, more preferably 0.0020 or less, and even more preferably 0.0010 or less, at 10 GHz, measured according to a cavity resonator perturbation method. Furthermore, a practical lower limit of the dielectric loss tangent is, for example, 0.0001 or more. The relative dielectric constant (Dk) and dielectric loss tangent (Df) are measured by the following method. 4.5 g of resin powder was placed in a stainless steel mold 100 mm x 30 mm x 1.0 mm high, placed in a vacuum press (Kitagawa Seiki Co., Ltd.), and held at 200 ° C, 220 ° C, and 240 ° C for 1.5 hours, then pressed at a surface pressure of 1.9 MPa to produce a cured plate. The cured plate was then downsized to a width of 1.0 mm, dried at 120 ° C for 60 minutes, and then measured for its relative permittivity (Dk) and dielectric loss tangent (Df) at 10 GHz using a perturbation cavity resonator. The measurement temperature was 23 ° C.

[0046] For polymers having a structural unit represented by formula (V) in this specification, the compounds described in paragraphs 0029 to 0058 of WO 2017 / 115813 and their synthesis reaction conditions, etc., the compounds described in paragraphs 0013 to 0058 of JP-A 2018-039995 and their synthesis reaction conditions, etc., the compounds described in paragraphs 0008 to 0043 of JP-A 2018-168347 and their synthesis reaction conditions, etc., the compounds described in paragraphs 0014 to 0042 of JP-A 2006-070136 and their synthesis reaction conditions, etc., the compounds described in paragraphs 0014 to 0061 of JP-A 2006-089683 and their synthesis reaction conditions, etc., the compounds described in paragraphs 0008 to 0036 of JP-A 2008-248001 and their synthesis reaction conditions, etc. can be referenced, and are incorporated herein.

[0047] When the resin composition of this embodiment contains a polymer having a structural unit represented by formula (V), the lower limit of its content is preferably 1 part by mass or more, more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, and may be 30 parts by mass or more, 40 parts by mass or more, 50 parts by mass or more, or 60 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the polymer having a structural unit represented by formula (V) to the above-mentioned lower limit or more, low dielectric properties, particularly a low relative dielectric constant, tend to be effectively achieved. Furthermore, the upper limit of the content of the polymer having a structural unit represented by formula (V) is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and may even be 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the polymer having a structural unit represented by formula (V) to the above-mentioned upper limit or less, metal foil peel strength and low water absorbency tend to be improved. The resin composition in this embodiment may contain only one type of polymer having a structural unit represented by formula (V), or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range. Furthermore, the resin composition in this embodiment may be configured to be substantially free of a polymer having a structural unit represented by formula (V). "Substantially free" means that the content of the polymer having the structural unit represented by formula (V) 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 the resin solid content in the resin composition.

[0048] <<<<Polyphenylene Ether Compound Having a Terminal Carbon-Carbon Unsaturated Double Bond>>> The resin composition of this embodiment preferably contains a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, and more preferably contains a polyphenylene ether compound containing two or more terminal carbon-carbon unsaturated double bonds. The polyphenylene ether compound containing two or more terminal carbon-carbon unsaturated double bonds preferably contains a polyphenylene ether compound having two or more groups (preferably vinylbenzyl groups) represented by formula (Rx-1) described below at its terminals. Use of these polyphenylene ether compounds tends to more effectively improve the low dielectric properties (Dk and / or Df) and low water absorption of printed wiring boards and the like. These properties are described in detail below.

[0049] Examples of polyphenylene ether compounds having a terminal carbon-carbon unsaturated double bond include compounds having a phenylene ether skeleton represented by the following formula (X1).

[0050] (In formula (X1), R ２４ , R ２５ , R ２６ , and R ２７ may be the same or different and represent an alkyl group having 6 or less carbon atoms, an aryl group, a halogen atom, or a hydrogen atom.

[0051] The polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond is represented by the formula (X2): (In formula (X2), R ２８ , R ２９ , R ３０ , R ３４ , and R ３５ may be the same or different and represent an alkyl group having 6 or less carbon atoms or a phenyl group. ３１ , R ３２ , and R ３３ may be the same or different and are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.) and / or 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 are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbon atoms.

[0052] The polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond is preferably a modified polyphenylene ether compound in which some or all of the terminals are functionalized with an ethylenically unsaturated group (hereinafter, sometimes referred to as a "modified polyphenylene ether compound (g)"), and more preferably a modified polyphenylene ether compound having two or more vinylbenzyl groups at the terminals. By using such a modified polyphenylene ether compound (g), it is possible to further reduce the dielectric dissipation factor (Df) of the cured product of the resin composition, and to improve the low water absorption and peel strength. These modified polyphenylene ether compounds (g) may be used alone or in combination of two or more.

[0053] The modified polyphenylene ether compound (g) may be a polyphenylene ether compound represented by formula (OP). (In formula (OP), X represents an aromatic group, and —(Y—O) ｎ１ - represents a polyphenylene ether structure, n1 represents an integer of 1 to 100, and n2 represents an integer of 1 to 4. Rx is a group represented by formula (Rx-1). (In formula (Rx-1), R １ , R ２ , and R ３ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * represents a bonding site with an oxygen atom. Each Mc independently represents a hydrocarbon group having 1 to 12 carbon atoms. z represents an integer of 0 to 4. r represents an integer of 0 to 6.

[0054] The aromatic group represented by X may or may not have a substituent on the benzene ring, but preferably has one. When the aromatic group has a substituent, examples thereof include the above-mentioned substituent Z, and the substituent is preferably at least one selected from the group consisting of an alkyl group having 6 or less carbon atoms, an aryl group, and a halogen atom, more preferably an alkyl group having 3 or less carbon atoms, and even more preferably a methyl group. In addition, the -(Y-O)n １ The polyphenylene ether structure represented by - may or may not have a substituent on the benzene ring, but preferably has one. When it has a substituent, examples of the substituent Z include the above-mentioned substituent Z, but it is preferably an alkyl group having 6 or less carbon atoms or a phenyl group, more preferably an alkyl group having 3 or less carbon atoms, and even more preferably a methyl group. １ and / or n ２ When n is an integer of 2 or more, １ n structural units (Y-O) and / or n ２ The n constitutional units may be the same or different. ２ is preferably 2 or more, more preferably 2.

[0055] In formula (Rx-1), R １ , R ２ , and R ３ R each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. １ is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. ２ and R ３ are each 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 each of the alkyl group, alkenyl group, and alkynyl group is preferably 5 or less, and more preferably 3 or less.

[0056] In formula (Rx-1), r represents an integer of 0 to 6, and may be an integer of 1 or more, and is preferably an integer of 5 or less, more preferably an integer of 4 or less, even more preferably an integer of 3 or less, still more preferably 1 or 2, and even more preferably 1.

[0057] In formula (Rx-1), each 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, still 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 of 0 to 4, preferably an integer of 0 to 3, more preferably an integer of 0 to 2, still more preferably 0 or 1, and still more preferably 0.

[0058] A specific example of the group represented by formula (Rx-1) is a vinylbenzyl group.

[0059] The modified polyphenylene ether compound (g) includes a compound represented by formula (OP-1). (In formula (OP-1), X represents an aromatic group, and —(Y—O)n ２ - represents a polyphenylene ether structure, and R １ , R ２ , and R ３ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group; n １ represents an integer of 0 to 6, and n ２ represents an integer from 1 to 100, and n ３represents an integer of 1 to 4.) The aromatic group represented by X may or may not have a substituent on the benzene ring, but preferably has one. When the aromatic group has a substituent, examples thereof include the above-mentioned substituent Z, but it is preferably at least one selected from the group consisting of an alkyl group having 6 or less carbon atoms, an aryl group, and a halogen atom, more preferably an alkyl group having 3 or less carbon atoms, and even more preferably a methyl group. In addition, the -(Y-O)n ２ The polyphenylene ether structure represented by - may or may not have a substituent on the benzene ring, but preferably has one. When it has a substituent, examples of the substituent Z include the above-mentioned substituent Z, but it is preferably an alkyl group having 6 or less carbon atoms or a phenyl group, more preferably an alkyl group having 3 or less carbon atoms, and even more preferably a methyl group. ２ and / or n ３ When n is an integer of 2 or more, ２ n structural units (Y-O) and / or n ３ The n constitutional units may be the same or different. ３ is preferably 2 or more, more preferably 2.

[0060] The modified polyphenylene ether compound (g) in this embodiment is preferably a compound represented by formula (OP-2). Here, -(O-X-O)- represents the formula (OP-3): (In formula (OP-3), R ４ , R ５ , R ６ , R ９ , R １０ , and R １１ may be the same or different and are alkyl groups or phenyl groups having 6 or less carbon atoms. ７ , and R ９ may be the same or different and are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.) and / or a group represented by formula (OP-4): (In formula (OP-4), R １２ , R １３ , R １４ , R１５ , R １６ , R １７ , R １８ , and R １９ may be the same or different and are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. -A- is a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbon atoms.

[0061] In addition, -(Y-O)- represents a group represented by formula (OP-5): (In formula (OP-5), R ２０ , R ２１ may be the same or different and are alkyl groups or phenyl groups having 6 or less carbon atoms. ２２ , R ２３ may be the same or different and are a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. ２０ and R ２１ are each independently a group having one or more methyl groups and / or cyclohexyl groups, the rigidity of the resulting resin molecules is increased, and since highly rigid molecules have lower mobility than less rigid molecules, the relaxation time during dielectric relaxation is longer, resulting in excellent low dielectric properties (Dk and / or Df, particularly Dk), which is preferable. An example of formula (OP-5) is the following structure. For the polyphenylene ether compound having the above structure, the description in JP 2019-194312 A can be referred to, the contents of which are incorporated herein by reference.

[0062] In formula (OP-2), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100. a and b each independently represent an integer of 0 to 50, more preferably an integer of 1 to 30, and preferably an integer of 1 to 10. When a and / or b is an integer of 2 or greater, two or more -(Y-O)- groups may each independently represent an arrangement of one type of structure, or two or more types of structures may be arranged in blocks or randomly. Furthermore, when a compound represented by formula (OP-2) is contained, the average value of a preferably satisfies 1<a<10, and the average value of b preferably satisfies 1<b<10.

[0063] Examples of -A- in formula (OP-4) include divalent organic groups such as a methylene group, an ethylidene group, a 1-methylethylidene group, a 1,1-propylidene group, a 1,4-phenylenebis(1-methylethylidene) group, a 1,3-phenylenebis(1-methylethylidene) group, a cyclohexylidene group, a phenylmethylene group, a naphthylmethylene group, and a 1-phenylethylidene group, but are not limited to these.

[0064] 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 less carbon atoms, and R ７ , R ８ , R ２２ , and R ２３is a hydrogen atom or an alkyl group having 3 or less carbon atoms, and it is particularly preferred that -(O-X-O)- represented by formula (OP-3) or formula (OP-4) is formula (OP-9), formula (OP-10), and / or formula (OP-11), and that -(Y-O)- represented by formula (OP-5) is formula (OP-12) or formula (OP-13). When a and / or b are integers of 2 or more, the two 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 blocks or randomly.

[0065] (In formula (OP-10), R ４４ , R ４５ , R ４６ , and R ４７ may be the same or different and are a hydrogen atom or a methyl group. -B- is a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms. Specific examples of -B- include the same as the specific examples of -A- in formula (OP-4). (In formula (OP-11), -B- represents a linear, branched, or cyclic divalent hydrocarbon group having 20 or less carbon atoms.) Specific examples of -B- include the same as the specific examples of -A- in formula (OP-4).

[0066] The modified polyphenylene ether compound (g) is more preferably a compound represented by formula (OP-15). (In formula (OP-15), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100.) a and b in formula (OP-15) each independently have the same meanings as a and b in formula (OP-2), and the preferred ranges are also the same.

[0067] In addition, the polyphenylene ether compound used in this embodiment may also be a compound represented by formula (OP-16). (In formula (OP-16), each x independently represents an integer of 0 to 100, and at least one of the two x's is an integer of 1 to 100.)

[0068] The polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond may be produced by a known method, or a commercially available product may be used. Examples of commercially available modified polyphenylene ether compounds having terminal vinylbenzyl groups include "OPE-2St1200" and "OPE-2St2200" manufactured by Mitsubishi Gas Chemical Company, Inc. Furthermore, as modified polyphenylene ether compounds having terminal vinylbenzyl groups, those obtained by modifying a terminal hydroxyl group, such as "SA90" manufactured by SABIC Innovative Plastics, with vinylbenzyl chloride or the like, to form vinylbenzyl groups may also be used.

[0069] In addition, for details of polyphenylene ether compounds having terminal carbon-carbon unsaturated double bonds, see JP 2006-028111 A, JP 2018-131519 A, WO 2019-138992, and WO 2022-054303. The contents of these publications are incorporated herein by reference.

[0070] The polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond (preferably a modified polyphenylene ether compound (g)) preferably has a polystyrene-equivalent number average molecular weight (details follow the method described in the Examples below) measured by GPC (gel permeation chromatography) of 500 or more and 3,000 or less. A number average molecular weight of 500 or more tends to further suppress stickiness when the resin composition of the present 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. Furthermore, the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond (preferably a modified polyphenylene ether compound (g)) preferably has a polystyrene-equivalent weight average molecular weight (details follow the method described in the Examples below) measured by GPC of 800 or more and 10,000 or less, more preferably 800 or more and 5,000 or less. When the weight-average molecular weight is equal to or greater than the lower limit, the dielectric constant (Dk) and dielectric loss tangent (Df) of a cured product of the resin composition tend to be lower, and when the weight-average molecular weight is equal to or less than the upper limit, the solubility, low viscosity, and moldability of the resin composition in a solvent when preparing a varnish or the like, which will be described later, tend to be improved.

[0071] Furthermore, the terminal carbon-carbon unsaturated double bond equivalent of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond (preferably a modified polyphenylene ether compound (g)) is preferably 400 to 5000 g, and more preferably 400 to 2500 g, per carbon-carbon unsaturated double bond. When the terminal carbon-carbon unsaturated double bond equivalent is equal to or greater than the lower limit, the dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product of the resin composition tend to be lower, while when it is equal to or less than the upper limit, the solubility in solvents, low viscosity, and moldability of the resin composition tend to be further improved.

[0072] The functional group equivalent (carbon-carbon unsaturated double bond equivalent) of a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond is calculated from the reciprocal of the amount of double bonds determined from the results of measurement using an infrared spectrometer. The double bond equivalent [g / eq.] was determined as follows: A powder of the polyphenylene ether compound is weighed and the weight is recorded. This powder is placed in a measuring flask and then diluted to a predetermined amount with carbon disulfide to prepare a measurement sample. This sample liquid is placed in a measurement cell and set in an infrared spectrophotometer (FT / IR-4600, manufactured by JASCO Corporation). Subsequently, infrared spectroscopy of the sample liquid is performed. In the case of a vinyl group in a polyphenylene ether compound, the 905 cm －１ When the carbon-carbon unsaturated double bond is a methacrylic group, the peak area of ​​the spectrum around 1640 cm is recorded. －１ The peak area of ​​the spectrum near the peak is recorded. The double bond concentration [mol / L] is calculated from this area value and the calibration curve. The double bond equivalent is then calculated using the following formula: Double bond equivalent [g / eq.] = Powder weight in measurement sample [g] / Double bond concentration [mol / L] × Measurement sample liquid volume [L]. The functional group equivalent of thermosetting compounds other than polyphenylene ether compounds having terminal carbon-carbon unsaturated double bonds can also be measured using the same method. However, for compounds (monomers) that can be expressed by a single molecular weight, the value calculated by (theoretical molecular weight ÷ number of functional groups) is used as the functional group equivalent. When two or more other thermosetting compounds are included, the functional group equivalent of the other thermosetting compounds is the sum (weighted average) of the values ​​obtained by multiplying the functional group equivalent of each of the other thermosetting compounds by their mass fraction.

[0073] When the resin composition of this embodiment contains a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, the lower limit of the 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, and even more preferably 20 parts by mass or more, per 100 parts by mass of the resin solids in the resin composition. Depending on the application, it may be 30 parts by mass or more, or 35 parts by mass or more. By ensuring that the content of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond is equal to or greater than the above lower limit, the moldability of the resin composition and the heat resistance, low water absorption, and low dielectric properties (Dk and / or Df) of the resulting cured product tend to be further improved. Furthermore, the upper limit of the content of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, and may even be 70 parts by mass or less, 60 parts by mass or less, or 50 parts by mass or less, per 100 parts by mass of the resin solids in the resin composition. By setting the content of the polyphenylene ether compound to the above upper limit or less, the low dielectric properties (particularly low dielectric tangent) and chemical resistance of the obtained cured product tend to be improved. The resin composition in this embodiment may contain only one type of polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, or may contain two or more types. When two or more types are contained, it is preferable that the total amount be in the above range.

[0074] <<<Other Aromatic Vinyl Resins (D)>>> In addition to the above, examples of the aromatic vinyl resin (D) include the descriptions in paragraphs 0011 to 0025 of WO 2023 / 176766, the descriptions in paragraphs 0012 to 0033 of WO 2023 / 176764, the descriptions in paragraphs 0012 to 0033 of WO 2023 / 176763, and the descriptions in paragraphs 0026 to 0043 of WO 2023 / 176765. The contents of these descriptions are incorporated herein by reference.

[0075] <<Maleimide Compound (E)>> The resin composition of this embodiment preferably contains a maleimide compound (E). In this embodiment, the maleimide compound (E) is preferably a compound having one or more (preferably two or more, more preferably 2 to 12, even more preferably 2 to 6, still more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2) maleimide groups per molecule. More specifically, the maleimide compound (E) preferably contains one or more selected from the group consisting of compounds represented by formulae (M0) to (M7), more preferably contains one or more selected from the group consisting of compounds represented by formulae (M0), (M1), (M3), (M4), and (M5), more preferably contains one or more selected from the group consisting of compounds represented by formulae (M0), (M1), (M3), and (M5), and from the viewpoint of low dielectric properties (Dk and / or Df), it is even more preferable that the maleimide compound (E) contains a compound represented by formula (M1).

[0076] (In formula (M0), R ５１ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R ５２ each independently represents a hydrogen atom or a methyl group; n １ represents an integer of 1 or more. ５１ are each independently preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and a methyl group, and even more preferably a hydrogen atom. ５２ is preferably a methyl group. １ is preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably an integer of 1 to 3, even more preferably 1 or 2, and even more preferably 1. The compound represented by formula (M0) may be a single type or a mixture of two or more types. Examples of the mixture include compounds represented by formula (M0) such as １a mixture of compounds with different R ５１ and / or R ５２ a mixture of compounds having different types of substituents, a mixture of compounds having different bonding positions (meta, para, or ortho positions) of the maleimide group and the oxygen atom relative to the benzene ring, and a mixture of compounds having a combination of two or more of the above differences. The same applies to the compounds represented by formulas (M1) to (M7) below.

[0077] (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ R each independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ each independently represents a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4- to 6-membered alicyclic group. 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 R each independently represents a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ R each independently represents a hydrogen atom or an organic group. 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.

[0078] R in the formula Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４R each 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, an ethyl group, a propyl group, or a butyl group, with a methyl group being particularly preferred. Ｍ１ and R Ｍ３ are each independently preferably an alkyl group, and R Ｍ２ and R Ｍ４ is preferably a hydrogen atom. Ｍ５ and R Ｍ６ Each of Ar independently represents a hydrogen atom or an alkyl group, and an alkyl group is preferable. The alkyl group here is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and among these, a methyl group is particularly preferable. Ｍ represents a divalent aromatic group, preferably a phenylene group, a naphthalenediyl group, a phenanthrenediyl group, or an anthracenediyl group, more preferably a phenylene group, and even more preferably an m-phenylene group. Ｍ may have a substituent, and the substituent 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, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. Ｍ is preferably unsubstituted. A is a 4- to 6-membered alicyclic group, and more preferably a 5-membered alicyclic group (preferably a group that forms an indane ring when combined with a benzene ring). When A is a 5-membered alicyclic group that forms an indane ring when combined with a benzene ring, the low dielectric properties (Dk and / or Df) of the resulting cured product tend to be further improved. R Ｍ７ and R Ｍ８ 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 Ｍ１０R each independently represents a hydrogen atom or an alkyl group, with an alkyl group being more preferred. The alkyl group here is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group, an ethyl group, a propyl group, or a butyl group, with a methyl group being particularly preferred. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ R each 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, an ethyl group, a propyl group, or a butyl group, with a methyl group being particularly preferred. Ｍ１２ and R Ｍ１３ are each independently preferably an alkyl group, and R Ｍ１１ and R Ｍ１４ is preferably a hydrogen atom. Ｍ１５each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a halogen atom, a hydroxyl group, or a mercapto group, 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 even more preferably 0. nx represents an integer of 1 to 20. nx may be an integer of 10 or less. The resin composition of this embodiment may contain only one or more compounds represented by formula (M1) having at least different values ​​of nx. When two or more types are contained, the average value of nx (average number of repeating units) n in the compound represented by formula (M1) in the resin composition is preferably 0.92 or more, more preferably 0.95 or more, even 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), low melt viscosity, and excellent handleability. Furthermore, n is preferably 10.0 or less, more preferably 8.0 or less, even more preferably 7.0 or less, even more preferably 6.0 or less, and may be 5.0 or less. The same applies to formula (M1-1) described later.

[0079] The compound represented by formula (M1) is preferably a compound represented by the following formula (M1-1): (In formula (M1-1), R Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ R each independently represents a hydrogen atom or an organic group. Ｍ２５ and R Ｍ２６ R each independently represents a hydrogen atom or an alkyl group. Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ R each independently represents a hydrogen atom or an organic group. Ｍ３１ and R Ｍ３２R each independently represents a hydrogen atom or an alkyl group. Ｍ３３ , R Ｍ３４ , R Ｍ３５ , and R Ｍ３６ R each independently represents a hydrogen atom or an organic group. Ｍ３７ , R Ｍ３８ , and R Ｍ３９ each independently represents a hydrogen atom or an alkyl group; and nx represents an integer of 1 or more and 20 or less.

[0080] R in the formula Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ R each 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, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. Ｍ２１ and R Ｍ２３ is preferably an alkyl group, and R Ｍ２２ and R Ｍ２４ is preferably a hydrogen atom. Ｍ２５ and R Ｍ２６ R each independently represents a hydrogen atom or an alkyl group, preferably an alkyl group. The alkyl group here is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and among these, a methyl group is particularly preferred. Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ R each independently represents a hydrogen atom or an organic group, preferably a hydrogen atom. 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, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. Ｍ３１ and R Ｍ３２R each independently represents a hydrogen atom or an alkyl group, preferably an alkyl group. The alkyl group here is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and among these, a methyl group is particularly preferred. Ｍ３３ , R Ｍ３４ , R Ｍ３５ , and R Ｍ３６ R each 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, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably a methyl group. Ｍ３３ and R Ｍ３６ is preferably a hydrogen atom, and R Ｍ３４ and R Ｍ３５ is preferably an alkyl group. Ｍ３７ , R Ｍ３８ , and R Ｍ３９ each independently represents a hydrogen atom or an alkyl group, with an alkyl group being preferred. The alkyl group here is preferably an alkyl group having 1 to 12 carbon atoms, more preferably an alkyl group having 1 to 6 carbon atoms, further preferably a methyl group, an ethyl group, a propyl group, or a butyl group, with a methyl group being particularly preferred. nx represents an integer of 1 to 20. nx may also be an integer of 10 or less.

[0081] The compound represented by formula (M1-1) is preferably a compound represented by the following formula (M1-2): (In formula (M1-2), R Ｍ２１ , R Ｍ２２ , R Ｍ２３ , and R Ｍ２４ R each independently represents a hydrogen atom or an organic group. Ｍ２５ and R Ｍ２６ R each independently represents a hydrogen atom or an alkyl group. Ｍ２７ , R Ｍ２８ , R Ｍ２９ , and R Ｍ３０ R each independently represents a hydrogen atom or an organic group. Ｍ３１ and R Ｍ３２R each independently represents a hydrogen atom or an alkyl group. Ｍ３３ , R Ｍ３４ , R Ｍ３５ , and R Ｍ３６ R each independently represents a hydrogen atom or an organic group. Ｍ３７ , R Ｍ３８ , and R Ｍ３９ each independently represents a hydrogen atom or an alkyl group; and nx represents an integer of 1 or more and 20 or less.

[0082] 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 formula (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 nx, and the preferred ranges are also the same.

[0083] The compound represented by formula (M1-1) is preferably a compound represented by the following formula (M1-3), and more preferably a compound represented by the following formula (M1-4). (In formula (M1-3), nx represents an integer of 1 or more and 20 or less.) nx may be an integer of 10 or less. (In formula (M1-4), nx represents an integer of 1 or more and 20 or less.)

[0084] 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. By making the molecular weight equal to or greater than the lower limit, the low dielectric properties and low water absorption of the resulting cured product tend to be further improved. 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. By making the molecular weight equal to or less than the upper limit, the heat resistance and handleability of the resulting cured product tend to be further improved.

[0085] (In formula (M2), R ５４ each independently represents a hydrogen atom or a methyl group; n ４ represents an integer of 1 or more. ４ is preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably an integer of 1 to 3, still more preferably 1 or 2, and may be 1. In the compound represented by formula (M2), n ４ It may be, and is preferably, a mixture of compounds in which the other moieties are different. Furthermore, as described in the compound represented by formula (M0), it may be a mixture of compounds in which the other moieties are different.

[0086] (In formula (M3), R ５５ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; n ５ represents an integer of 1 or more and 10 or less.) R ５５ are each independently preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and a methyl group, and even more preferably a hydrogen atom.５ is preferably an integer of 1 or more and 5 or less, more preferably an integer of 1 to 3, and even more preferably 1 or 2. The compound represented by formula (M3) may be a mixture of compounds where n5 is different, and a mixture is preferred. Furthermore, as described in the section on the compound represented by formula (M0), it may also be a mixture of compounds where the other moieties are different.

[0087] (In formula (M4), R ５６ each independently represents a hydrogen atom, a methyl group, or an ethyl group; R ５７ each independently represents a hydrogen atom or a methyl group.

[0088] (In formula (M5), R ５８ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R ５９ each independently represents a hydrogen atom or a methyl group; n ６ represents an integer of 1 or more. ５８ are each independently preferably a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, or a phenyl group, more preferably one of a hydrogen atom and a methyl group, and even more preferably a hydrogen atom. ５９ is preferably a methyl group. ６ is preferably an integer of 1 to 10, more preferably an integer of 1 to 5, even more preferably an integer of 1 to 3, still more preferably 1 or 2, and may be 1. In the compound represented by formula (M5), n ６ The compound represented by formula (M0) may be a mixture of compounds having different moieties, and is preferably a mixture. As described in the compound represented by formula (M0), the compound may be a mixture of compounds having different moieties.

[0089] The maleimide compound (M6) is a compound having a structural unit represented by formula (M6) and maleimide groups at both ends of the molecular chain. (In formula (M6), R ６１represents 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 represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. ６３ Each independently represents a linear or branched alkyl group having 1 to 16 carbon atoms, or a linear or branched alkenyl group having 2 to 16 carbon atoms. Each n independently represents an integer of 0 to 10.) For details of the maleimide compound (M6) and a production method thereof, please refer to paragraphs 0061 to 0066 of WO 2020 / 262577, the contents of which are incorporated herein by reference.

[0090] The maleimide compound (M7) is a maleimide compound obtained by reacting raw materials (1) 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. The maleimide compound (M7) is preferably a compound represented by formula (M7). (In the above formula (M7), R １ each independently represents an alkyl group having 1 to 10 carbon atoms; R ２ each independently represents an alkyl group, alkoxy group, or alkylthio group having 1 to 10 carbon atoms; an aryl group, aryloxy group, or arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each independently represents a hydrogen atom or a methyl group, and R ３ and R ４ one of which is a hydrogen atom and the other is a methyl group, and R ５ and R ６ one of which is a hydrogen atom and the other is a methyl group, １ are each independently represented by the following formula (x): (In formula (x), R ７ and R ８ each independently represents a hydrogen atom or a methyl group, and R７ and R ８ one of which is a hydrogen atom and the other is a methyl group, and R ９ each independently represents an alkyl group, alkoxy group, or alkylthio group having 1 to 10 carbon atoms; an aryl group, aryloxy group, or arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, and t represents an integer of 0 to 4. １ X per benzene ring to which １ is the average number of substitutions, and represents a number from 0 to 4, 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.

[0091] For details of the maleimide compound (M7) used in this embodiment, please refer to the description in Japanese Patent No. 7160151, the contents of which are incorporated herein by reference.

[0092] The maleimide compound (E) may be produced by a known method, or a commercially available product may be used. Examples of commercially available products include "BMI-80" manufactured by K.I. Chemical Industry 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 Daiwa Kasei Kogyo 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), "BMI-70" manufactured by K.I. Chemical Industry Co., Ltd. as the compound represented by formula (M4), "MIR-5000" manufactured by Nippon Kayaku Co., Ltd. as the compound represented by formula (M5), "MIZ-001" manufactured by Nippon Kayaku Co., Ltd. as the maleimide compound (M6), and "NE-X-9500" manufactured by DIC Corporation as the maleimide compound (M7).

[0093] In addition to the above, as the maleimide compound (E), compounds described in paragraphs 0061 to 0066 of WO 2020 / 262577 and Japanese Patent No. 7160151 can be referred to, the contents of which are incorporated herein by reference.

[0094] Furthermore, examples of the maleimide compound (E) other than those mentioned above include compounds having two or more maleimide groups, and specific examples thereof include m-phenylene bismaleimide, 2,2-bis(4-(4-maleimidophenoxy)-phenyl)propane, 4-methyl-1,3-phenylene bismaleimide, 1,6-bismaleimide-(2,2,4-trimethyl)hexane, 4,4'-diphenylether bismaleimide, 4,4'-diphenylsulfone bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene, prepolymers thereof, and prepolymers of these maleimides and amines.

[0095] The maleimide group equivalent of the maleimide compound (E) 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, and even more preferably 200 g / eq. or more, and is 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. By setting it to be equal to or greater than the lower limit, the low dielectric properties (Dk and / or Df, particularly Df) of the obtained cured product tend to be more excellent. Furthermore, by setting it to be equal to or less than the upper limit, the peel strength of the obtained cured product tends to be more excellent.

[0096] When the resin composition of this embodiment contains the maleimide compound (E), 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 even more preferably 15 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. Depending on the intended use, it may be 20 parts by mass or more, 25 parts by mass or more, or 30 parts by mass or more. When the content of the maleimide compound (E) is 1 part by mass or more, the flame resistance of the resulting cured product tends to be improved. Furthermore, the upper limit of the content of the maleimide compound (E) 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 50 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. Depending on the intended use, it may even be 40 parts by mass or less, or 30 parts by mass or less. When the content of the maleimide compound (E) is 90 parts by mass or less, the peel strength and low water absorbency tend to be improved. The resin composition in this embodiment may contain only one maleimide compound (E), or may contain two or more maleimide compounds (E). When two or more maleimide compounds (E) are contained, the total amount is preferably in the above range.

[0097] <<Cyanate Ester Compound>> The resin composition of this embodiment may contain a cyanate ester compound. The cyanate ester compound of this embodiment is not particularly limited as long as it contains one or more cyanate groups (cyanato groups) in one molecule (preferably two or more, more preferably 2 to 12, even more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and even more preferably 2), and a wide variety of compounds commonly used in the field of printed wiring boards can be used. Furthermore, the cyanate ester compound is preferably a compound in which the cyanate group is directly bonded to an aromatic skeleton (aromatic ring). Preferred examples of the cyanate ester compound in this embodiment include at least one selected from the group consisting of phenol novolac-type cyanate ester compounds, naphthol aralkyl-type cyanate ester compounds (naphthol aralkyl-type cyanates), naphthylene ether-type cyanate ester compounds, biphenyl aralkyl-type cyanate ester compounds, xylene resin-type cyanate ester compounds, trisphenolmethane-type cyanate ester compounds, adamantane skeleton-type cyanate ester compounds, bisphenol M-type cyanate ester compounds, bisphenol A-type cyanate ester compounds, and diallyl bisphenol A-type cyanate ester compounds. Among these, from the viewpoint of further improving the low water absorption of the obtained cured product, at least one selected from the group consisting of phenol novolac cyanate ester compounds, naphthol aralkyl cyanate ester compounds, naphthylene ether cyanate ester compounds, xylene resin cyanate ester compounds, bisphenol M cyanate ester compounds, bisphenol A cyanate ester compounds, and diallyl bisphenol A cyanate ester compounds is more preferable, at least one selected from the group consisting of phenol novolac cyanate ester compounds and naphthol aralkyl cyanate ester compounds is even more preferable, and naphthol aralkyl cyanate ester compounds are even more preferable. These cyanate ester compounds may be prepared by known methods, or commercially available products may be used.In addition, cyanate ester compounds having a naphthol aralkyl skeleton, a naphthylene ether skeleton, a xylene skeleton, a trisphenolmethane skeleton, or an adamantane skeleton have a relatively large functional group equivalent weight and a small number of unreacted cyanate ester groups, so that cured products of resin compositions using these compounds tend to have even more excellent low water absorption. Furthermore, mainly due to the presence of an aromatic skeleton or an adamantane skeleton, plating adhesion tends to be even more improved.

[0098] As the naphthol aralkyl cyanate ester compound, a compound represented by the following formula (1) is more preferred. (In formula (1), R 3 each independently represents a hydrogen atom or a methyl group, and n3 represents an integer of 1 or greater.

[0099] In formula (1), R 3 each independently represents a hydrogen atom or a methyl group, and among these, a hydrogen atom is preferred. In formula (1), n3 represents an integer of 1 or more, preferably an integer of 1 to 20, more preferably an integer of 1 to 10, and even more preferably an integer of 1 to 6.

[0100] The novolac-type cyanate ester compound is not particularly limited, but is preferably, for example, a compound represented by the following formula (VII). (In formula (VII), R ６ each independently represents a hydrogen atom or a methyl group, and n7 represents an integer of 1 or greater.

[0101] In formula (VII), R ６ each independently represents a hydrogen atom or a methyl group, and among these, a hydrogen atom is preferable. In formula (VII), n7 represents an integer of 1 or more, preferably an integer of 1 to 20, more preferably an integer of 1 to 10, and even more preferably an integer of 1 to 6.

[0102] As the bisphenol A type cyanate ester compound, one or more compounds selected from the group consisting of 2,2-bis(4-cyanatophenyl)propane and prepolymers of 2,2-bis(4-cyanatophenyl)propane may be used.

[0103] The resin composition of this embodiment preferably contains a cyanate ester compound within a range that does not impair the effects of the present invention. When the resin composition of this embodiment contains a cyanate ester compound, the lower limit of the cyanate ester compound content is preferably 0.1 parts by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. When the cyanate ester compound content is 0.1 parts by mass or more, the heat resistance, flame resistance, chemical resistance, low dielectric properties (low dielectric constant, low dielectric dissipation factor), and insulating properties of the resulting cured product tend to be improved. When the resin composition of this embodiment contains a cyanate ester compound, the upper limit of the cyanate ester compound content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. The resin composition of this embodiment may contain only one type of cyanate ester compound, or may contain two or more types of cyanate ester compounds. When two or more types are contained, the total amount is preferably within the above range.

[0104] <<(Meth)allyl Compound>> The resin composition of this embodiment may contain a (meth)allyl compound. The (meth)allyl compound preferably contains an allyl compound. The (meth)allyl compound is preferably a compound containing two or more (meth)allyl groups, more preferably a compound containing two or more allyl groups. The (meth)allyl compound preferably contains at least one selected from the group consisting of a (meth)allyl isocyanurate compound, a tri(meth)allyl cyanurate compound, a (meth)allyl group-substituted nadimide compound, a (meth)allyl compound having a glycoluril structure, and a diallyl phthalate. More preferably, the (meth)allyl compound contains at least one selected from the group consisting of a (meth)allyl isocyanurate compound, a (meth)allyl group-substituted nadimide compound, and a (meth)allyl compound having a glycoluril structure. Still more preferably, the (meth)allyl isocyanurate compound and / or a (meth)allyl group-substituted nadimide compound is further preferred. Still more preferably, the (meth)allyl group-substituted nadimide compound is further preferred.

[0105] Examples of the tri(meth)allyl cyanurate compound include tri(meth)allyl cyanurate compounds (for example, triallyl cyanurate having the structure shown below). Examples of the (meth)allyl compound include resins having an allyl group described in WO 2022 / 210095 (for example, compounds described in Synthesis Examples 3, 4, 6, 20, and 22 of the same publication), the contents of which are incorporated herein by reference.

[0106] When the resin composition of this embodiment contains a (meth)allyl compound, its molecular weight is preferably 195 or more, more preferably 300 or more, and may be 400 or more, or even 500 or more. By making it equal to or greater than the lower limit, low dielectric properties and heat resistance tend to be further improved. The molecular weight of the (meth)allyl compound is also preferably 3000 or less, more preferably 2000 or less, even more preferably 1000 or less, and even more preferably 800 or less. By making it equal to or less than the upper limit, low thermal expansion tends to be further improved.

[0107] When the resin composition of this embodiment contains a (meth)allyl compound, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may even be 10 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl compound to be equal to or greater than the above-mentioned lower limit, excellent moldability and heat resistance tend to be further improved. Furthermore, the upper limit of the content of the (meth)allyl compound is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl compound to be equal to or less than the above-mentioned upper limit, low thermal expansion tends to be further improved. The resin composition of this embodiment may contain only one type of (meth)allyl compound, or may contain two or more types. When two or more types are contained, the total amount preferably falls within the above-mentioned range.

[0108] <<<(Meth)allyl isocyanurate compound>>> The (meth)allyl isocyanurate compound is not particularly limited as long as it is a compound having two or more (meth)allyl groups and an isocyanurate ring (nurate skeleton). Since the (meth)allyl isocyanurate compound has a large number of (meth)allyl groups that serve as crosslinking points, it tends to be strongly cured with the maleimide compound (E), and a cured product having low dielectric properties (Dk and / or Df) and excellent heat resistance is obtained. As the (meth)allyl isocyanurate compound, a compound represented by formula (TA) is preferred. Formula (TA) (In formula (TA), R Ａ represents a substituent).

[0109] In formula (TA), R Ａ represents a substituent, and is more preferably a substituent having a formula weight of 15 to 500.

[0110] R ＡA first example is an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 2 to 22 carbon atoms. By using an allyl compound having an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 2 to 22 carbon atoms, a resin composition can be provided that is excellent in crosslinkability and can yield a cured product with high toughness. This can prevent cracking during etching or other processes, even when the resin composition does not contain a substrate such as glass cloth. From the viewpoint of improving handleability, the number of carbon atoms in the alkyl group and / or alkenyl group is preferably 3 or more, more preferably 8 or more, and may even be 12 or more or 18 or less. This improves the resin flow properties of the resin composition, which is believed to result in improved circuit filling properties when using the resin composition of this embodiment to fabricate a multilayer circuit board or the like.

[0111] R Ａ A second example of R is a group containing an allyl isocyanurate group. Ａ When the compound represented by formula (TA) contains an allyl isocyanurate group, the compound represented by formula (TA) is preferably a compound represented by formula (TA-1). (In formula (TA-1), R Ａ２ is a divalent linking group.

[0112] In formula (TA-1), R Ａ２ is preferably a divalent linking group having a formula weight of 54 to 250, more preferably a divalent linking group having a formula weight of 54 to 250 and both ends of which are carbon atoms, and even more preferably an aliphatic hydrocarbon group having 2 to 20 carbon atoms (however, the aliphatic hydrocarbon group may contain an ether group or may have a hydroxyl group). More specifically, R Ａ２ is preferably a group represented by any one of the following formulas (i) to (iii): (In formulas (i) to (iii), p ｃ１ represents the number of repeating methylene units and is an integer of 2 to 18. ｃ２ represents the number of repeating units of the oxyethylene group, and is 0 or 1. * represents a bonding site. ｃ１is preferably an integer of 2 to 10, more preferably an integer of 3 to 8, and even more preferably an integer of 3 to 5. ｃ２ may be 0 or 1, but is preferably 1.

[0113] R Ａ A third example is a phosphorus-based substituent.

[0114] R Ａ２ is preferably the first example.

[0115] In this embodiment, it is preferable that the reactive group (allyl group) equivalent of the compound represented by formula (TA) is 1000 g / eq. or less. If the equivalent is 1000 g / eq. or less, it is believed that a high Tg can be obtained more reliably.

[0116] Examples of the alkyl group having 1 to 22 carbon atoms include linear or branched alkyl groups, such as methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, and docosyl groups. Examples of the alkenyl group having 2 to 22 carbon atoms include allyl and decenyl groups.

[0117] Specific examples of the compound represented by formula (TA) include triallyl isocyanurate, 5-octyl-1,3-diallyl isocyanurate, 5-dodecyl-1,3-diallyl isocyanurate, 5-tetradecyl-1,3-diallyl isocyanurate, 5-hexadecyl-1,3-diallyl isocyanurate, 5-octadecyl-1,3-diallyl isocyanurate, 5-eicosyl-1,3-diallyl isocyanurate, 5-docosyl-1,3-diallyl isocyanurate, and 5-decenyl-1,3-diallyl isocyanurate. These may be used alone or in combination of two or more, or may be used as a prepolymer.

[0118] The method for producing the compound represented by formula (TA) is not particularly limited, but for example, the compound can be obtained by reacting diallyl isocyanurate with an alkyl halide in an aprotic polar solvent such as N,N'-dimethylformamide, in the presence of a basic substance such as sodium hydroxide, potassium carbonate, or triethylamine, at a temperature of about 60°C to 150°C.

[0119] Furthermore, commercially available compounds represented by formula (TA) can also be used. Commercially available compounds include, but are not limited to, L-DAIC manufactured by Shikoku Chemical Industries Ltd., and P-DAIC having a phosphorus-based substituent manufactured by Shikoku Chemical Industries Ltd. An example of triallyl isocyanurate is TAIC manufactured by Shinryo Corporation. An example of a compound represented by formula (TA-1) is DD-1 manufactured by Shikoku Chemical Industries Ltd.

[0120] The molecular weight of the (meth)allyl isocyanurate compound (preferably a compound represented by formula (TA)) is preferably 200 or more, more preferably 300 or more, and may be 400 or more, or even 500 or more. By setting the molecular weight to be equal to or greater than the above-mentioned lower limit, the low dielectric properties (Dk and / or Df) and heat resistance of the obtained cured product tend to be further improved. Furthermore, the molecular weight of the (meth)allyl isocyanurate compound (preferably a compound represented by formula (TA)) is preferably 3000 or less, more preferably 2000 or less, even more preferably 1000 or less, and even more preferably 800 or less. By setting the molecular weight to be equal to or less than the above-mentioned upper limit, the low thermal expansion properties of the obtained cured product tend to be further improved.

[0121] When the resin composition of this embodiment contains a (meth)allyl isocyanurate compound, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may even be 10 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl isocyanurate compound at or above the above-mentioned lower limit, the resin composition tends to have excellent moldability, and the heat resistance and low thermal expansion properties of the obtained cured product tend to be further improved. Furthermore, the upper limit of the content of the (meth)allyl isocyanurate compound is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and may even be 20 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl isocyanurate compound at or below the above-mentioned upper limit, the heat resistance and low dielectric properties (Dk and / or Df) of the obtained cured product tend to be further improved. The resin composition of this embodiment may contain only one type of (meth)allyl isocyanurate compound, or may contain two or more types of (meth)allyl isocyanurate compounds. When two or more types are contained, the total amount is preferably within the above range.

[0122] <<<<(Meth)allyl Group-Substituted Nadimide Compound>>> The (meth)allyl group-substituted nadimide compound is not particularly limited as long as it is a compound having two or more (meth)allyl group-substituted nadimide groups in the molecule. Specific examples include compounds represented by the following formula (AN-1): (In formula (AN-1), R １ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms; R ２ represents an alkylene group having 1 to 6 carbon atoms, a phenylene group, a biphenylene group, a naphthylene group, or a group represented by formula (AN-2) or (AN-3). (In formula (AN-2), R ３ is a methylene group, an isopropylidene group, —C(═O)—, —O—, —S—, or —S(═O) ２ represents a group represented by the formula: (In formula (AN-3), R ４each independently represents an alkylene group having 1 to 4 carbon atoms or a cycloalkylene group having 5 to 8 carbon atoms.

[0123] Furthermore, commercially available compounds represented by formula (AN-1) can also be used. Examples of commercially available compounds include, but are not limited to, the compound represented by formula (AN-4) (BANI-M (manufactured by Maruzen Petrochemical Co., Ltd.)) and the compound represented by formula (AN-5) (BANI-X (manufactured by Maruzen Petrochemical Co., Ltd.)). These compounds may be used alone or in combination of two or more. Formula (AN-4)

[0124] The molecular weight of the (meth)allyl group-substituted nadimide compound (preferably a compound represented by formula (AN)) is preferably 400 or more, more preferably 500 or more, and may be 550 or more. By setting the molecular weight of the (meth)allyl group-substituted nadimide compound to the above-mentioned lower limit or more, low dielectric properties, low thermal expansion properties, and heat resistance tend to be further improved. The molecular weight of the (meth)allyl group-substituted nadimide compound (preferably a compound represented by formula (AN)) is also preferably 1500 or less, more preferably 1000 or less, even more preferably 800 or less, and may be 700 or less, or 600 or less. By setting the molecular weight of the (meth)allyl group-substituted nadimide compound to the above-mentioned upper limit or less, moldability and peel strength tend to be further improved.

[0125] When the resin composition of the present embodiment contains a (meth)allyl group-substituted nadimide compound (preferably a compound represented by formula (AN)), the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may even be 10 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl group-substituted nadimide compound to be equal to or greater than the above-mentioned lower limit, excellent moldability and further improved low dielectric properties, low thermal expansion, and heat resistance tend to be achieved. Furthermore, the upper limit of the content of the (meth)allyl group-substituted nadimide compound (preferably a compound represented by formula (AN)) is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and may even be 20 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl group-substituted nadimide compound to be equal to or less than the above-mentioned upper limit, moldability and peel strength tend to be further improved. The resin composition of the present embodiment may contain only one (meth)allyl group-substituted nadimide compound, or may contain two or more (meth)allyl group-substituted nadimide compounds. When two or more (meth)allyl group-substituted nadimide compounds are contained, the total amount is preferably in the above range.

[0126] <<<(Meth)allyl Compound Having a Glycoluril Structure>>> The (meth)allyl compound having a glycoluril structure is not particularly limited as long as it is a compound containing a glycoluril structure and two or more (meth)allyl groups. When a (meth)allyl compound having a glycoluril structure is blended into a resin composition, the number of (meth)allyl groups can be increased, that is, the number of crosslinking points can be increased. Therefore, similar to the (meth)allyl isocyanurate compound, it tends to be firmly cured with a maleimide compound (E) or the like, and a cured product having low dielectric properties (Dk and / or Df) and excellent heat resistance can be obtained. In this embodiment, the (meth)allyl compound having a glycoluril structure is preferably a compound represented by formula (GU). Formula (GU) (In formula (GU), R １ are each independently a hydrogen atom or a substituent, and R １ At least two of R are groups containing a (meth)allyl group.２ each independently represents a hydrogen atom, an alkyl group, or an aryl group. １ are each independently preferably a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or an alkenyl group having 2 to 5 carbon atoms, more preferably an alkenyl group having 2 to 5 carbon atoms, more preferably a (meth)allyl group, and even more preferably an allyl group. １ In formula (GU), it is preferable that three or four of R are groups containing a (meth)allyl group, and it is more preferable that four of R are groups containing a (meth)allyl group. ２ are each independently preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group, and more preferably a hydrogen atom or a methyl group.

[0127] Specific examples of the compound represented by formula (GU) include 1,3,4,6-tetraarylglycoluril (in formula (GU), R １ are all allyl groups, and R ２ are all hydrogen atoms).

[0128] The (meth)allyl compound having a glycoluril structure may be commercially available, and examples thereof include, but are not limited to, TA-G manufactured by Shikoku Chemicals Corporation.

[0129] The molecular weight of the (meth)allyl compound having a glycoluril structure (preferably a compound represented by formula (GU)) is preferably 195 or more, more preferably 220 or more, even more preferably 250 or more, and may be 300 or more, or 400 or more. By setting the molecular weight of the (meth)allyl compound having a glycoluril structure to the above-mentioned lower limit or more, the heat resistance and low thermal expansion of the obtained cured product tend to be further improved. The molecular weight of the (meth)allyl compound having a glycoluril structure (preferably a compound represented by formula (GU)) is also preferably 1500 or less, more preferably 1000 or less, even more preferably 800 or less, and may be 700 or less, or 600 or less. By setting the molecular weight of the (meth)allyl compound having a glycoluril structure to the above-mentioned upper limit or less, the low dielectric properties (Dk and / or Df) and heat resistance of the obtained cured product tend to be further improved.

[0130] When the resin composition of the present embodiment contains a (meth)allyl compound having a glycoluril structure (preferably a compound represented by formula (GU)), the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may even be 10 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl compound having a glycoluril structure to be equal to or greater than the above-mentioned lower limit, the resin composition tends to have excellent moldability, and the heat resistance and low thermal expansion of the obtained cured product tend to be further improved. Furthermore, the upper limit of the content of the (meth)allyl compound having a glycoluril structure (preferably a compound represented by formula (GU)) is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 25 parts by mass or less, and may even be 20 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)allyl compound having a glycoluril structure to be equal to or less than the above-mentioned upper limit, the low dielectric properties (Dk and / or Df) of the obtained cured product tend to be further improved. The resin composition of the present embodiment may contain only one (meth)allyl compound having a glycoluril structure, or may contain two or more (meth)allyl compounds. When two or more compounds are contained, the total amount is preferably in the above range.

[0131] <<<<(Meth)acrylate Compound>>> The resin composition of this embodiment may contain a (meth)acrylate compound. The (meth)acrylate compound used in this embodiment may be a monofunctional (meth)acrylate compound containing one (meth)acryloyloxy group in one molecule, or a polyfunctional (meth)acrylate compound containing two or more (meth)acryloyloxy groups in one molecule. In this embodiment, a polyfunctional (meth)acrylate compound is preferred.

[0132] The polyfunctional (meth)acrylate compound used in this embodiment is preferably a compound having three to five (meth)acryloyloxy groups, more preferably a compound having three or four (meth)acryloyloxy groups, and even more preferably a compound having three (meth)acryloyloxy groups. The (meth)acrylate compound is preferably a compound having a methacryloyloxy group. Since the polyfunctional (meth)acrylate compound has a large number of (meth)acrylate groups that serve as crosslinking points, it is firmly cured with the aromatic vinyl resin (D) or the maleimide compound (E), and a cured product having low dielectric properties (Dk and / or Df) and excellent heat resistance is obtained. The polyfunctional (meth)acrylate compound is preferably a compound represented by formula (MA). Formula (MA) (In formula (MA), R １ represents a hydrogen atom or a substituent, R ２ each independently represents a hydrogen atom or a methyl group.

[0133] In formula (MA), R １ represents a hydrogen atom or a substituent, and is more preferably a substituent having a formula weight of 15 to 500, more preferably a substituent having a formula weight of 15 to 300, even more preferably a substituent having a formula weight of 15 to 100, and even more preferably a substituent having a formula weight of 15 to 50.

[0134] R １is preferably a hydrocarbon group or a (meth)acryloyloxy group, more preferably a hydrocarbon group having 22 or fewer carbon atoms, and even more preferably an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 2 to 22 carbon atoms. By using a compound having an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 2 to 22 carbon atoms, a resin composition can be provided that is excellent in crosslinkability and can yield a cured product with high toughness. This can prevent cracking during etching or other processes, even when the resin composition does not contain a substrate such as glass cloth. From the viewpoint of improving handleability, the number of carbon atoms in the alkyl group and / or alkenyl group is preferably 2 or more, and may be 8 or more, or even 12 or more and 18 or less. This is thought to improve the resin flow properties of the resin composition, resulting in improved circuit filling properties when using the resin composition of this embodiment to fabricate a multilayer circuit board or the like.

[0135] In this embodiment, the (meth)acrylic group equivalent of the compound represented by formula (MA) is preferably 1000 g / eq. or less. If the equivalent is 1000 g / eq. or less, a high Tg tends to be more reliably obtained. The lower limit of the (meth)acrylic group equivalent is, for example, 99 g / eq. or more.

[0136] The alkyl group having 1 to 22 carbon atoms is preferably a linear alkyl group having 1 to 22 carbon atoms or a branched alkyl group having 3 to 22 carbon atoms, such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, a decyl group, a dodecyl group, a tetradecyl group, a hexadecyl group, an octadecyl group, an eicosyl group, a docosyl group, etc. The alkenyl group having 2 to 22 carbon atoms is preferably an alkenyl group having 2 to 15 carbon atoms, such as an allyl group, a decenyl group, etc.

[0137] Specific examples of the compound represented by formula (MA) include trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, pentaerythritol tetra(meth)acrylate, etc. These may be used alone or in combination of two or more, or may be used as a prepolymer.

[0138] The compound represented by formula (MA) may also be commercially available. Although there is no particular limitation on the commercially available product, an example of the commercially available product is trimethylolpropane trimethacrylate, such as "NK Ester TMPT" manufactured by Shin-Nakamura Chemical Co., Ltd.

[0139] The molecular weight of the polyfunctional (meth)acrylate compound is preferably 200 or more, more preferably 300 or more, and may be 330 or more, 400 or more, or 500 or more. By setting the molecular weight to the above-mentioned lower limit or more, the low dielectric properties (Dk and / or Df) and heat resistance of the obtained cured product tend to be further improved. Furthermore, the molecular weight of the (meth)acrylate compound (preferably a compound represented by formula (MA)) is preferably 3000 or less, more preferably 2000 or less, even more preferably 1000 or less, and even more preferably 800 or less. By setting the molecular weight to the above-mentioned upper limit or less, the low thermal expansion properties of the obtained cured product tend to be further improved.

[0140] The (meth)acrylate compound may be a (meth)acrylate compound having a polyphenylene structure, and examples thereof include polyphenylene ether compounds represented by formula (OP-M). (In formula (OP-M), X represents an aromatic group, and —(Y—O) ｎ１ - represents a polyphenylene ether structure, n1 represents an integer of 1 to 100, and n2 represents an integer of 2 to 4. Rx is a group represented by formula (Rx-2). (In formula (Rx-2), R １ , R ２ , and R ３ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * indicates the bonding site to the oxygen atom.

[0141] X in formula (OP-M), —(Y—O) ｎ１ -, n1, and n2 represent X, -(Y-O) in formula (OP) described in the section on the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond. ｎ１ -, n1, and n2 have the same meanings and preferred ranges.

[0142] In formula (Rx-2), R １ , R ２ , and R ３ R each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. １ is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. ２ and R ３ are each 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 each of the alkyl group, alkenyl group, and alkynyl group is preferably 5 or less, and more preferably 3 or less.

[0143] The (meth)acrylate compound having a polyphenylene structure is more preferably a compound represented by formula (OP-14). (In formula (OP-14), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100.)

[0144] The (meth)acrylate compound having a polyphenylene structure may be produced by a known method, or a commercially available product such as "SA9000" manufactured by SABIC Innovative Plastics may be used.

[0145] In addition to the above, the (meth)acrylate compound may also be a resin having a (meth)acrylic group described in WO 2022 / 210095 (for example, the compounds described in Synthesis Examples 5 and 21 of the same publication) and a resin having a (meth)acrylic group described in Japanese Patent No. 6962507 (for example, the compounds described in Examples 1 to 9), or a compound described in paragraph 0049 of JP-A 2019-194312, the contents of which are incorporated herein by reference.

[0146] When the resin composition of this embodiment contains a (meth)acrylate compound, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and may even be 10 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)acrylate compound at or above the above-mentioned lower limit, the resin composition tends to have excellent moldability, and the heat resistance and low thermal expansion properties of the obtained cured product tend to be further improved. Furthermore, the upper limit of the content of the (meth)acrylate compound is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and may even be 20 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. By setting the content of the (meth)acrylate compound at or below the above-mentioned upper limit, the heat resistance and low dielectric properties (Dk and / or Df) of the obtained cured product tend to be further improved. The resin composition of this embodiment may contain only one type of (meth)acrylate compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above-mentioned range.

[0147] <<Epoxy Compound>> The resin composition of this embodiment may contain an epoxy compound. The epoxy compound is not particularly limited as long as it is a compound or resin having one or more epoxy groups (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, still more preferably 2 or 3, and still more preferably 2) per molecule, and a wide variety of compounds commonly used in the field of printed wiring boards can be used. Examples of the epoxy compound include phenol novolac epoxy resins, bisphenol A novolac epoxy resins, glycidyl ester epoxy resins, aralkyl novolac epoxy resins, biphenyl aralkyl epoxy resins, naphthylene ether epoxy resins, cresol novolac epoxy resins, multifunctional phenol epoxy resins, naphthalene epoxy resins, anthracene epoxy resins, naphthalene skeleton-modified novolac epoxy resins, phenol aralkyl epoxy resins, naphthol aralkyl epoxy resins, dicyclopentadiene epoxy resins, biphenyl epoxy resins, alicyclic epoxy resins, polyol epoxy resins, phosphorus-containing epoxy resins, glycidyl amines, glycidyl esters, compounds in which the double bonds of butadiene or the like have been epoxidized, and compounds obtained by reacting hydroxyl group-containing silicone resins with epichlorohydrin. Use of these compounds improves the moldability and adhesion of the resin composition. Among these, from the viewpoint of further improving flame retardancy and heat resistance, the epoxy compound is preferably one or more selected from the group consisting of biphenylaralkyl epoxy resins, naphthylene ether epoxy resins, polyfunctional phenolic epoxy resins, and naphthalene epoxy resins, and more preferably a biphenylaralkyl epoxy resin.

[0148] When the resin composition of this embodiment contains an epoxy compound, the content thereof is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the resin solid content in the resin composition. When the epoxy compound content is 0.1 parts by mass or more, the metal foil peel strength and toughness tend to be improved. The upper limit of the epoxy compound content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, and may be 8 parts by mass or less, or 5 parts by mass or less, relative to 100 parts by mass of the resin solid content in the resin composition. When the epoxy compound content is 50 parts by mass or less, the electrical properties of the resulting cured product tend to be improved. The resin composition of this embodiment may contain only one type of epoxy compound, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range. The resin composition of this embodiment may also be configured to be substantially free of epoxy compounds. "Substantially free" means that the content of epoxy compounds is less than 0.1 parts by mass, preferably less than 0.01 parts by mass, and even less than 0.001 parts by mass, per 100 parts by mass of the resin solids in the resin composition. By being substantially free of epoxy compounds, the low dielectric properties (Dk and / or Df) of the cured product tend to be further improved. That is, since epoxy groups are highly polar, not including such thermosetting compounds tends to achieve low dielectric properties (Dk and / or Df) of the cured product.

[0149] <<Phenol Compound>> The resin composition of this embodiment may contain a phenolic compound. The phenolic compound is not particularly limited as long as it has one or more phenolic hydroxyl groups (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, even more preferably 2 or 3, and even more preferably 2) per molecule. A wide variety of compounds commonly used in the field of printed wiring boards can be used. Examples of the phenolic compound include phenol novolac resins, bisphenol A novolac phenolic resins, glycidyl ester phenolic resins, aralkyl novolac phenolic resins, biphenyl aralkyl phenolic resins, cresol novolac phenolic resins, multifunctional phenolic resins, naphthol resins, naphthol novolac resins, multifunctional naphthol resins, anthracene phenolic resins, naphthalene skeleton-modified novolac phenolic resins, phenol aralkyl phenolic resins, naphthol aralkyl phenolic resins, dicyclopentadiene phenolic resins, biphenyl phenolic resins, alicyclic phenolic resins, polyol phenolic resins, phosphorus-containing phenolic resins, and hydroxyl group-containing silicone resins. Among these, from the viewpoint of further improving the flame resistance of the resulting cured product, it is preferable to select at least one selected from the group consisting of biphenyl aralkyl phenolic resins, naphthol aralkyl phenolic resins, phosphorus-containing phenolic resins, and hydroxyl group-containing silicone resins. In addition, as for the phenolic compound, the description in paragraphs 0012 to 0025 of WO 2023 / 176765 can also be taken into consideration, and the contents thereof are incorporated herein by reference.

[0150] When the resin composition of this embodiment contains a phenolic compound, the content thereof is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. The content is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less, and may even be 5 parts by mass or less. The resin composition of this embodiment may contain only one type of phenolic compound, or may contain two or more types. When two or more types are contained, the total amount is preferably within the above range. The resin composition of this embodiment may also be configured to be substantially free of phenolic compounds. "Substantially free" means that the content of phenolic compounds is less than 0.1 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0151] <<Oxetane Compound>> The resin composition of this embodiment may contain an oxetane compound. The oxetane compound is not particularly limited as long as it is a compound having one or more oxetanyl groups (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, even more preferably 2 or 3, and even more preferably 2), and a wide variety of compounds commonly used in the field of printed wiring boards can be used. Examples of the oxetane compound include oxetane, alkyloxetane (e.g., 2-methyloxetane, 2,2-dimethyloxetane, 3-methyloxetane, 3,3-dimethyloxetane, etc.), 3-methyl-3-methoxymethyloxetane, 3,3-di(trifluoromethyl)oxetane, 2-chloromethyloxetane, 3,3-bis(chloromethyl)oxetane, biphenyl oxetane, OXT-101 (manufactured by Toagosei Co., Ltd.), and OXT-121 (manufactured by Toagosei Co., Ltd.).

[0152] The resin composition of this embodiment preferably contains an oxetane compound to a degree that does not impair the effects of the present invention. When the resin composition of this embodiment contains an oxetane compound, the content thereof is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. When the content of the oxetane compound is 0.1 parts by mass or more, the metal foil peel strength and toughness of the resulting cured product tend to be improved. When the resin composition of this embodiment contains an oxetane compound, the upper limit of the content of the oxetane compound is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. When the content of the oxetane compound is 50 parts by mass or less, the electrical properties of the resulting cured product tend to be improved. The resin composition of this embodiment may contain only one oxetane compound, or may contain two or more oxetane compounds. When two or more types are contained, the total amount is preferably in the above range. Furthermore, the resin composition in this embodiment may be configured to be substantially free of oxetane compounds. "Substantially free" means that the content of the oxetane compounds is less than 0.1 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0153] <<Benzoxazine Compound>> The resin composition of this embodiment may contain a benzoxazine compound. The benzoxazine compound is not particularly limited as long as it is a compound having two or more (preferably 2 to 12, more preferably 2 to 6, even more preferably 2 to 4, even more preferably 2 or 3, and even more preferably 2) dihydrobenzoxazine rings per molecule, and a wide variety of compounds commonly used in the field of printed wiring boards can be used. Examples of benzoxazine compounds include bisphenol A-type benzoxazine BA-BXZ (manufactured by Konishi Chemical Co., Ltd.), bisphenol F-type benzoxazine BF-BXZ (manufactured by Konishi Chemical Co., Ltd.), and bisphenol S-type benzoxazine BS-BXZ (manufactured by Konishi Chemical Co., Ltd.).

[0154] The resin composition of this embodiment preferably contains a benzoxazine compound to the extent that the effects of the present invention are not impaired. When the resin composition of this embodiment contains a benzoxazine compound, the content thereof is preferably 0.1 parts by mass or more and preferably 50 parts by mass or less per 100 parts by mass of the resin solid content in the resin composition. The resin composition of this embodiment may contain only one type of benzoxazine compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is in the above range. Furthermore, the resin composition of this embodiment may be configured to be substantially free of a benzoxazine compound. "Substantially free" means that the content of the benzoxazine compound is less than 0.1 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0155] <<Compound Having a Vinylene Group>> The resin composition of this embodiment may contain a compound having a vinylene group. Examples of compounds having a vinylene group include compounds containing one or more -CH=CH- groups in the molecule, and compounds containing one -CH=CH- group in the molecule are preferred. Furthermore, compounds having a vinylene group that also qualify as the maleimide compound (B) are referred to as maleimide compounds. Specific examples of compounds having a vinylene group include acenaphthylene and pyracylene, with acenaphthylene being more preferred. In this specification, compounds that also qualify as compounds having a vinylene group but are explicitly listed as components other than compounds having a vinylene group (e.g., curing accelerators), such as the imidazole compounds described below, are not considered to be compounds having a vinylene group.

[0156] <Thermoplastic Elastomer (C)> The resin composition of this embodiment preferably contains a thermoplastic elastomer (C). By including the thermoplastic elastomer (C), a cured product with excellent low dielectric properties (Dk and / or Df) and minimal warpage during reflow can be obtained. In particular, by using a styrene-based elastomer with a small amount of styrene-derived structural units, compatibility with the aromatic vinyl resin (D) can be improved, thereby achieving low dielectric properties (Dk and / or Df) and minimizing warpage of the cured product. The thermoplastic elastomer (C) of this embodiment is not particularly limited, and examples thereof include at least one selected from the group consisting of polyisoprene, polybutadiene, styrene butadiene, butyl rubber, ethylene propylene rubber, styrene butadiene ethylene, styrene butadiene styrene, styrene isoprene styrene, styrene ethylene butylene styrene, styrene propylene styrene, styrene ethylene propylene styrene, fluororubber, silicone rubber, hydrogenated compounds thereof, alkyl compounds thereof, and copolymers thereof. Further, examples of the thermoplastic elastomer (C) include oligomers or polymers having a curable vinyl functional group, and polybutadiene resins described in paragraphs 0044 and 0045 of JP 2019-194312 A, the contents of which are incorporated herein by reference.

[0157] The number-average molecular weight of the thermoplastic elastomer (C) used in this embodiment is preferably 1,000 or more. By setting the number-average molecular weight to 1,000 or more, the resulting cured product tends to have better low dielectric properties (Dk and / or Df, particularly low dielectric dissipation factor). The number-average molecular weight is preferably 1,500 or more, more preferably 2,000 or more, and may be 60,000 or more, 70,000 or more, or 80,000 or more depending on the application. The upper limit of the number-average molecular weight of the thermoplastic elastomer (C) is preferably 400,000 or less, more preferably 350,000 or less, and even more preferably 300,000 or less. Setting the number-average molecular weight to the above upper limit or less tends to improve the solubility of the thermoplastic elastomer (C) component in the resin composition. When the resin composition of this embodiment contains two or more thermoplastic elastomers (C), it is preferable that the number-average molecular weight of the mixture thereof falls within the above range.

[0158] The thermoplastic elastomer (C) used in this embodiment may be a resin containing a polybutadiene structure. The polybutadiene structure may be partially or completely hydrogenated. Specific examples include B-1000, B-2000, B-3000, BI-2000, and BI-3000 manufactured by Nippon Soda Co., Ltd., and Ricon 100, Ricon 130, Ricon 131, Ricon 142, Ricon 150, Ricon 181, and Ricon 184 manufactured by CRAY VALLEY.

[0159] The thermoplastic elastomer (C) used in this embodiment may be a resin having a poly(meth)acrylate structure. Specific examples include Teisan Resin manufactured by Nagase ChemteX Corporation, and ME-2000, W-197C, KG-15, and KG-3000 manufactured by Negami Chemical Industrial Co., Ltd.

[0160] The thermoplastic elastomer (C) used in this embodiment may be a resin having a polycarbonate structure. Resins having a polycarbonate structure are sometimes referred to as "polycarbonate resins." Examples of such resins include carbonate resins without reactive groups, hydroxyl group-containing carbonate resins, phenolic hydroxyl group-containing carbonate resins, carboxyl group-containing carbonate resins, acid anhydride group-containing carbonate resins, isocyanate group-containing carbonate resins, urethane group-containing carbonate resins, and epoxy group-containing carbonate resins. Here, the term "reactive group" refers to a functional group capable of reacting with other components, such as a hydroxyl group, a phenolic hydroxyl group, a carboxyl group, an acid anhydride group, an isocyanate group, a urethane group, or an epoxy group. Specific examples of polycarbonate resins include FPC0220 and FPC2136 manufactured by Mitsubishi Gas Chemical Company, Inc., and T6002 and T6001 (polycarbonate diol) manufactured by Asahi Kasei Corporation.

[0161] The thermoplastic elastomer (C) used in this embodiment may be a resin having a polysiloxane structure, such as SMP-2006, SMP-2003PGMEA, SMP-5005PGMEA, KR-510, or SMP-7014-3S manufactured by Shin-Etsu Silicones Co., Ltd.

[0162] The thermoplastic elastomer (C) used in this embodiment may be a resin having a polyalkylene structure and / or a polyalkyleneoxy structure. The polyalkyleneoxy structure is preferably a polyalkyleneoxy structure having 2 to 15 carbon atoms, more preferably a polyalkyleneoxy structure having 3 to 10 carbon atoms, and particularly preferably a polyalkyleneoxy structure having 5 to 6 carbon atoms. Specific examples of resins having a polyalkylene structure and / or a polyalkyleneoxy structure include PTXG-1000 and PTXG-1800 manufactured by Asahi Kasei Fibers Corporation.

[0163] The thermoplastic elastomer (C) used in this embodiment is a resin having a polyisoprene structure, and specific examples include KL-610 and KL613 manufactured by Kuraray Co., Ltd.

[0164] The thermoplastic elastomer (C) used in this embodiment may be a resin having a polyisobutylene structure, such as SIBSTAR-073T (styrene-isobutylene-styrene triblock copolymer) and SIBSTAR-042D (styrene-isobutylene diblock copolymer), both manufactured by Kaneka Corporation.

[0165] In this embodiment, the thermoplastic elastomer (C) is preferably a thermoplastic elastomer containing a styrene compound unit and one or more selected from the group consisting of a butadiene unit, an isoprene unit, a hydrogenated butadiene unit, and a hydrogenated isoprene unit (hereinafter referred to as "thermoplastic elastomer (c1)"). By using such a thermoplastic elastomer (c1), the low dielectric properties (Dk and / or Df, particularly low dielectric loss tangent) of the resulting cured product are more excellent. Here, "styrene compound unit" refers to a structural unit derived from a styrene compound, "butadiene unit" refers to a structural unit derived from butadiene, and "hydrogenated butadiene unit" refers to a hydrogenated structural unit derived from butadiene. The same applies to other structural units.

[0166] The thermoplastic elastomer (c1) contains a styrene compound unit. The inclusion of the styrene compound unit improves the solubility of the thermoplastic elastomer (c1) in the resin composition. Examples of styrene compounds 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 standpoints of availability and productivity. Of these, styrene is particularly preferred. The content of the styrene compound unit in the thermoplastic elastomer (c1) is preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 35% by mass or more, and preferably 70% by mass or less, more preferably 65% ​​by mass or less, even more preferably 60% by mass or less, and even more preferably 55% by mass or less, of the total thermoplastic elastomer (C). A styrene compound unit content of at least the lower limit mentioned above is preferred because compatibility and heat resistance tend to be improved. Furthermore, by setting the content of the styrene compound unit to the above upper limit or less, the low thermal expansion property becomes better. The thermoplastic elastomer (c1) may contain only one type of styrene compound unit, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is within the above range. The method for measuring the content of the styrene compound unit in the thermoplastic elastomer (c1) of this embodiment can be found in WO 2017 / 126469, the contents of which are incorporated herein by reference. The same applies to the conjugated diene unit A, etc., described below.

[0167] The thermoplastic elastomer (c1) also 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 units A"). The thermoplastic elastomer (c1) preferably contains one or more units selected from the group consisting of hydrogenated butadiene units and hydrogenated isoprene units as essential components, and also contains one or more units selected from the group consisting of butadiene units and isoprene units.

[0168] In the thermoplastic elastomer (c1), the mass ratio of the styrene compound units to the conjugated diene units A (styrene compound units / conjugated diene units A) is preferably in the range of 5 / 95 to 75 / 25, more preferably 30 / 70 to 65 / 35, even more preferably 35 / 65 to 60 / 40, and still more preferably 35 / 65 to 55 / 45. When the mass ratio of the styrene compound units to the conjugated diene units A is in the above range, compatibility and heat resistance are improved.

[0169] The thermoplastic elastomer (c1) may or may not contain other monomer units in addition to the styrene compound units and the conjugated diene units A. Examples of other monomer units include aromatic vinyl compound units other than styrene compound units. In the thermoplastic elastomer (c1), the total of the styrene compound units and the conjugated diene units A preferably accounts for 90% by mass or more of the total monomer units, more preferably 95% by mass or more, even more preferably 97% by mass or more, and even more preferably 99% by mass or more, and is 100% by mass or less. As described above, the thermoplastic elastomer (c1) may contain only one type of styrene compound unit and one type of conjugated diene unit A, or two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0170] The thermoplastic elastomer (c1) 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. An unhydrogenated elastomer or a partially hydrogenated elastomer is preferred. In one embodiment of this embodiment, the thermoplastic elastomer (c1) is a hydrogenated elastomer. Here, the hydrogenated elastomer includes elastomers with a hydrogenation rate (hydrogenation rate) of 80% or more, as well as elastomers with a hydrogenation rate (hydrogenation rate) of 100%. The hydrogenation rate of the hydrogenated elastomer is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. The hydrogenation rate is preferably 85% or more, more preferably 90% or more, and even more preferably 95% or more. 1 It is calculated from the results of H-NMR spectrum measurement. In one embodiment of this embodiment, the thermoplastic elastomer (c1) is an unhydrogenated elastomer. Here, the unhydrogenated elastomer refers to an elastomer in which the proportion of hydrogenated double bonds based on the conjugated diene units A in the elastomer, i.e., the hydrogenation rate (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 refers to an elastomer in which some of the double bonds based on the conjugated diene units A in the elastomer are hydrogenated, and typically refers to an elastomer in which the hydrogenation rate (hydrogenation rate) is less than 80% but more than 20%.

[0171] The thermoplastic elastomer (c1) is preferably 10 GPa or less, more preferably 6 GPa or less, and even more preferably 4 GPa or less, at a strain of 0.05% to 0.25% when subjected to a tensile test using a Shimadzu Autograph AGS-X Puls at a test speed of 10 mm / min. By adjusting the modulus to be equal to or greater than the lower limit, warping of the resulting cured product can be effectively suppressed. When the resin composition of this embodiment contains two or more thermoplastic elastomers (c1), it is preferable that the sum (weighted average value) of the modulus of elasticity of each thermoplastic elastomer (c1) multiplied by its mass fraction falls within the above range.

[0172] The thermoplastic elastomer (c1) may have a reactive functional group at the molecular end or in the molecular chain. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxyl group, an amino group, an amide group, an isocyanato group, an acryloyl group, a methacryloyl group, and a vinyl group. From the viewpoint of adhesion to metals, the reactive functional group is preferably an epoxy group, a hydroxyl group, a carboxyl group, an amino group, or an amide group, and from the viewpoint of further improving heat resistance and insulation reliability, more preferably an epoxy group, a hydroxyl group, or an amino group.

[0173] Examples of commercially available products of the thermoplastic elastomer (C) used in this embodiment include SEPTON (registered trademark) 2104, V9461, and S8104 manufactured by Kuraray Co., Ltd., S.O.E. (registered trademark) S1606, S1613, S1609, and S1605 manufactured by Asahi Kasei Corporation, Tuftec (registered trademark) H1041, H1043, P2000, and MP10 manufactured by Asahi Kasei Corporation, and DYNARON (registered trademark) 9901P and TR2250 manufactured by Eneos Material Corporation.

[0174] When the resin composition of this embodiment contains a thermoplastic elastomer (C), the content thereof is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 10 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. Depending on the application, the content may be 12 parts by mass or more, 15 parts by mass or more, or 18 parts by mass or more. By setting the content at or above the lower limit, the low dielectric loss tangent tends to be further improved. Furthermore, the upper limit of the content of the thermoplastic elastomer (C) is 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, per 100 parts by mass of the resin solid content in the resin composition. By setting the content at or below the upper limit, the heat resistance tends to be further improved. The resin composition of this embodiment may contain only one type of thermoplastic elastomer (C), or may contain two or more types. When two or more types are contained, the total amount preferably falls within the above range.

[0175] <Curing Accelerator> The resin composition of the present embodiment may further contain a curing accelerator. The curing accelerator is not particularly limited, and examples thereof include imidazoles such as 2-ethyl-4-methylimidazole and triphenylimidazole; 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)hexyne-3; azo compounds such as azobisnitrile; N,N-dimethylbenzylamine, N,N-dimethylaniline, N,N-dimethyltoluidine, 2-N-ethylanilinoethanol, tri-n-butylamine, pyridine, quinoline, and N-methylmorpholine. tertiary amines such as triethanolamine, triethylenediamine, tetramethylbutanediamine, and N-methylpiperidine; phenols such as phenol, xylenol, cresol, resorcinol, and catechol; high-temperature decomposition radical generators such as 2,3-dimethyl-2,3-diphenylbutane; organic metal salts such as lead naphthenate, lead stearate, zinc naphthenate, zinc octoate, manganese octoate, tin oleate, dibutyltin maleate, manganese naphthenate, cobalt naphthenate, and iron acetylacetonate; compounds obtained by dissolving these organic metal salts in hydroxyl-containing compounds such as phenol and bisphenol; inorganic metal salts such as tin chloride, zinc chloride, and aluminum chloride; and organic tin compounds such as dioctyltin oxide, other alkyl tins, and alkyl tin oxides. Among these, the preferred curing accelerator is at least one selected from the group consisting of imidazoles, organic metal salts, and organic peroxides, with at least one selected from the group consisting of imidazoles and organic peroxides being more preferred.

[0176] When the resin composition of this embodiment contains a curing accelerator, the lower limit of its content is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. The upper limit of the curing accelerator content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 2 parts by mass or less, even more preferably 1.5 parts by mass or less, even more preferably 1.0 parts by mass or less, even more preferably 0.8 parts by mass or less, and even more preferably 0.7 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. The resin composition of this embodiment is preferable because the resin composition can be sufficiently cured even when the content of the curing accelerator is 0.8 parts by mass or less. The curing accelerators can be used alone or in combination of two or more. When two or more types are used, the total amount falls within the above range.

[0177] <Flame Retardant> The resin composition of this embodiment may contain a flame retardant. Examples of flame retardants include phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, and silicone-based flame retardants, with phosphorus-based flame retardants being preferred. Known flame retardants can be used, including, for example, halogen-based flame retardants such as brominated epoxy resin, brominated polycarbonate, brominated polystyrene, brominated styrene, brominated phthalimide, tetrabromobisphenol A, pentabromobenzyl (meth)acrylate, pentabromotoluene, tribromophenol, hexabromobenzene, decabromodiphenyl ether, bis-1,2-pentabromophenylethane, chlorinated polystyrene, and chlorinated paraffin; red phosphorus; tricresyl phosphate; triphenyl phosphate; and cresyl diphenyl phosphate. Examples of suitable flame retardants include phosphorus-based flame retardants such as phosphate, trixylenyl phosphate, trialkyl phosphate, dialkyl phosphate, tris(chloroethyl)phosphate, phosphazene, 1,3-phenylenebis(2,6-dixylenyl phosphate), and 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; inorganic flame retardants such as aluminum hydroxide, magnesium hydroxide, partial boehmite, boehmite, zinc borate, and antimony trioxide; and silicone-based flame retardants such as silicone rubber and silicone resin. In this embodiment, of these, 1,3-phenylenebis(2,6-dixylenyl phosphate) is preferred because it does not impair the low dielectric properties (Dk and / or Df).

[0178] When the resin composition of this embodiment contains a flame retardant, the content thereof is preferably 1 part by mass or more, more preferably 3 parts by mass or more, even more preferably 5 parts by mass or more, and even more preferably 7 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. The lower limit of the content of the flame retardant is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. The flame retardants can be used alone or in combination of two or more. When two or more types are used, the total amount falls within the above range.

[0179] <Active ester compound> The resin composition of the present embodiment may contain an active ester compound within a range that does not impair the effects of the present invention. The active ester compound is not particularly limited, and for example, the description in paragraphs 0064 to 0066 of WO 2021 / 172317 can be referred to, the contents of which are incorporated herein by reference.

[0180] When the resin composition of this embodiment contains an active ester compound, the amount is preferably 1 part by mass or more and preferably 50 parts by mass or less per 100 parts by mass of the resin solid content in the resin composition. The resin composition of this embodiment may contain only one type of active ester compound, or may contain two or more types. When two or more types are contained, it is preferable that the total amount is in the above range. Furthermore, the resin composition of this embodiment may be configured to be substantially free of an active ester compound. "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 the resin solid content in the resin composition.

[0181] <Aromatic Oligomer> The resin composition of this embodiment may contain an aromatic oligomer. The aromatic oligomer is an oligomer having a structural unit derived from an aromatic vinyl compound, and typically refers to a compound having a weight-average molecular weight of less than 3,000. The aromatic oligomer is also typically a thermoplastic oligomer. Note that the aromatic oligomer in this embodiment does not include compounds explicitly listed in any of the above sections, such as a polymer having a structural unit represented by formula (V) or a thermoplastic elastomer (C). 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 alone or in combination of two or more. Among these, styrene, α-methylstyrene, and 4-methylstyrene are preferred, and α-methylstyrene is more preferred.

[0182] The aromatic oligomer may contain a constituent unit derived from a monomer other than an aromatic vinyl compound, such as (meth)acrylic acid, a (meth)acrylic acid derivative, (meth)acrylamide, a (meth)acrylamide derivative, (meth)acrylonitrile, isoprene, 1,3-butadiene, ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, N-vinylindole, N-vinylphthalimide, N-vinylpyrrolidone, N-vinylcarbazole, or N-vinylcaprolactam.

[0183] The content of structural 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, still more preferably 90% by mass or more, and even more preferably 95% by mass or more.

[0184] The weight average molecular weight (Mw) of the aromatic oligomer is preferably 300 or more, more preferably 500 or more, and even more preferably 1,000 or more, and is usually less than 3,000, preferably 2,800 or less, more preferably 2,500 or less, and may be 2,000 or less. The weight average molecular weight (Mw) of the aromatic oligomer is a value determined by gel permeation chromatography in terms of standard polystyrene.

[0185] 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. One type of aromatic oligomer may be used alone, or two or more types may be used in combination.

[0186] 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 Crystalle EASTMAN aromatic polymers such as KRYSTALEX 3070 (styrene / α-methylstyrene copolymer, softening point 70°C, Mw 950), KRYSTALEX 3085 (styrene / α-methylstyrene copolymer, softening point 85°C, Mw 1150), and KRYSTALEX 3100 (styrene / α-methylstyrene copolymer, softening point 100°C, Mw 1500); 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), FTR-6100 (styrene / aliphatic hydrocarbon copolymer, softening point 95°C, Mw 1210; manufactured by Mitsui Chemicals), FTR-6110 (styrene / aliphatic hydrocarbon copolymer, softening point 110°C, Mw 1570; manufactured by Mitsui Chemicals), FTR-6125 (styrene / aliphatic hydrocarbon copolymer, softening point 110°C, Mw 1570; manufactured by Mitsui Chemicals), Examples of suitable aromatic oligomers include FTR-7100 (styrene / α-methylstyrene / aliphatic hydrocarbon copolymer, softening point 100°C, Mw 1440; manufactured by Mitsui Chemicals), FTR-0100 (poly-α-methylstyrene, softening point 100°C, Mw 1960; manufactured by Mitsui Chemicals), and FTR-2120 (styrene / α-methylstyrene copolymer, softening point 120°C, Mw 2630; manufactured by Mitsui Chemicals). In addition to the above, examples of suitable aromatic oligomers include those described in paragraphs 0069 to 0087 of WO 2017 / 135168, which are incorporated herein by reference.

[0187] When the resin composition of this embodiment contains an aromatic oligomer, the content thereof 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 even be 4 parts by mass or more, per 100 parts by mass of the resin solid content. By setting the content at or above the lower limit, the relative dielectric constant and dielectric loss tangent tend to be further reduced. Furthermore, 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 even be 8 parts by mass or less, per 100 parts by mass of the resin solid content. By setting the content at or below the upper limit, chemical resistance tends to be further improved. The resin composition of this embodiment may contain only one type of aromatic oligomer, or may contain two or more types. When two or more types are contained, the total amount preferably falls within the above range.

[0188] <Other Fillers> The resin composition of this embodiment may or may not contain fillers such as the hollow silica (A), solid silica, and porous silica (sometimes referred to as "other fillers" in this specification). As the other fillers, those generally used in the art can be suitably used. Specific examples include metal oxides such as alumina, titanium white, titanium oxide, zinc oxide, magnesium oxide, and zirconium oxide; composite oxides such as zinc borate, zinc stannate, forsterite, barium titanate, strontium titanate, and calcium titanate; nitrides such as boron nitride, aggregated boron nitride, silicon nitride, and aluminum nitride; aluminum hydroxide; heat-treated aluminum hydroxide (aluminum hydroxide that has been heat-treated to remove some of the water of crystallization); boehmite; metal hydroxides (including hydrates) such as magnesium hydroxide; and molybdenum compounds such as molybdenum oxide and zinc molybdate. Examples of fillers include inorganic fillers such as barium sulfate, clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, A-glass, NE-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, short glass fibers (including glass fine powders such as E-glass, T-glass, D-glass, S-glass, 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. The resin composition of this embodiment preferably does not substantially contain other fillers. "Substantially free" means that the content of other fillers contained in the resin composition is less than 10% by mass of the hollow silica contained in the resin composition, preferably less than 5% by mass, more preferably less than 3% by mass, and even more preferably less than 1% by mass.

[0189] <Silane Coupling Agent> The resin composition of the present embodiment may further contain a silane coupling agent. The inclusion of a silane coupling agent tends to further improve the dispersibility of the hollow silica (A) and the filler added as needed, and the adhesive strength between the resin component and the hollow silica (A) and the substrate described below. The silane coupling agent is not particularly limited, and examples thereof include silane coupling agents generally used in the surface treatment of inorganic substances, 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, etc.), styrylsilane compounds (e.g., styryltrimethoxysilane, etc.), acrylsilane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), methacrylsilane compounds (e.g., γ-methacryloxypropyltrimethoxysilane, etc.), cationic silane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), phenylsilane compounds, etc. The silane coupling agents may 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 parts by mass per 100 parts by mass of the resin solid content.

[0190] <Dispersant> The resin composition of this embodiment may contain a dispersant. As the dispersant, those generally used for paints can be suitably used, and the type is not particularly limited. As the dispersant, a copolymer-based wetting dispersant is preferably used, and specific examples thereof include DISPERBYK (registered trademark)-110, 111, 161, 180, 2009, 2152, 2155, BYK (registered trademark)-W996, W9010, W903, and W940, manufactured by BYK Japan K.K.

[0191] When the resin composition of this embodiment contains a dispersant, the lower limit of the 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 the resin solid content 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 the resin solid content in the resin composition. The dispersants can be used alone or in combination of two or more. When two or more types are used, the total amount falls within the above range.

[0192] <Solvent> The resin composition of this embodiment may contain a solvent, and preferably contains an organic solvent. When a solvent is contained, the resin composition of this embodiment is in a form (solution or varnish) in which at least a portion, preferably all, of the various resin solid components described above are dissolved or compatible in the solvent. The solvent is not particularly limited as long as it is a polar organic solvent or a non-polar organic solvent that can dissolve or compatible at least a portion, preferably all, of the various resin solid components described above. 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 non-polar organic solvents include aromatic hydrocarbons (e.g., toluene, xylene, etc.). The solvents may be used alone or in combination of two or more. When two or more solvents are used, the total amount falls within the above range.

[0193] <Other Components> In addition to the above components, the resin composition of this embodiment may contain various polymeric compounds such as thermoplastic resins and their oligomers, petroleum resins, and various additives. Examples of additives include ultraviolet absorbers, antioxidants, photopolymerization initiators, fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, flow modifiers, lubricants, antifoaming agents, leveling agents, gloss agents, and polymerization inhibitors. These additives may be used alone or in combination of two or more. In the resin composition of this embodiment, the thermosetting resin (B) (preferably, the aromatic vinyl resin (D), the maleimide compound (E), and the cyanate ester compound blended as needed), the thermoplastic elastomer (C), and the flame retardant together account for 90% by mass or more of the resin solids, more preferably 95% by mass or more, and even more preferably 98% by mass or more. In the resin composition of the present embodiment, the total of the aromatic vinyl resin (D), the maleimide compound (E), the thermoplastic elastomer (C), and the flame retardant accounts for 90% by mass or more of the resin solid content, more preferably 95% by mass or more, and even more preferably 98% by mass or more.

[0194] <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-tangent material, such as an insulating layer for a printed wiring board, a semiconductor package material, or other electronic material resin composition. The resin composition of this embodiment can be suitably used as a material for a prepreg, a metal foil-clad laminate using a prepreg, a resin composite sheet, and a printed wiring board.

[0195] The resin composition of this embodiment preferably has a low dielectric constant (Dk) and dielectric loss tangent (Df) of the cured product. Specifically, the dielectric constant (Dk) and dielectric loss tangent (Df) of a sample obtained by removing the metal foil from a metal foil-clad laminate molded using a prepreg formed from the resin composition of this embodiment are preferably low. More specifically, the resin composition is impregnated into NE glass cloth so that the resin composition content is 70% by volume, and heated and dried at 155 ° C for 5 minutes to obtain 0.1 mm thick prepregs. Eight sheets of 12 μm thick electrolytic copper foil are placed on both sides and pressed to obtain a copper foil-clad laminate. The copper foil on both sides is removed by etching from the copper foil on both sides. The dielectric loss tangent (Df) at a frequency of 10 GHz measured by a cavity resonator perturbation method in accordance with JIS C218:2007 is preferably 0.0025 or less, more preferably 0.0022 or less. The lower limit of the dielectric loss tangent (Df) is not particularly specified, but a practical value is, for example, 0.0001 or more. Furthermore, the relative dielectric constant (Dk) at a frequency of 10 GHz measured by a cavity resonator perturbation method in accordance with JIS C218:2007 for the 0.8 mm thick sample is preferably 3.0 or less. The lower limit of the relative dielectric constant (Dk) is not particularly specified, but a practical value is, for example, 0.01 or more. The above-mentioned low dielectric properties (Dk and / or Df) can be achieved by using hollow silica (A) and an aromatic vinyl resin (D) and / or a maleimide compound (E) as the thermosetting resin (B). The aromatic vinyl resin (D) preferably contains at least one selected from the group consisting of a polymer having a structural unit represented by formula (V) and a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond. The maleimide compound (E) preferably contains one or more compounds selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M3), and a compound represented by formula (M5), and more preferably contains a compound represented by formula (M1).Radical curing, which can also be achieved by curing a resin composition by radical curing, tends to cure rapidly within a specific temperature range, allowing the resin composition to be cured more densely, and the resulting cured product can achieve lower dielectric properties (Dk and / or Df). That is, an example of the resin composition of this embodiment is a radically curable resin composition. The dielectric loss tangent (Df) and relative dielectric constant (Dk) of the cured product are more specifically measured by the method described in the Examples below.

[0196] The resin composition of this embodiment also preferably has a low coefficient of thermal expansion when cured. The resin composition of this embodiment is impregnated into NE glass cloth so that the resin composition content is 70% by volume, and the resulting prepreg is heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. 12 μm thick electrolytic copper foil is placed on both sides of the resulting copper foil-clad laminate, which is then pressed. The copper foil on both sides is removed by etching, and the resulting sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. When the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C, the coefficient of thermal expansion in the in-plane direction at 60 to 120°C is preferably 10 ppm / °C or less, more preferably 9 ppm / °C or less, and even more preferably 5 ppm / °C or less. In practical terms, 0 ppm / °C or more is sufficient. Such low thermal expansion can be achieved by blending a resin with a low elastic modulus, using a styrene-based thermoplastic elastomer with a low content of styrene compound units, or the like.

[0197] The resin composition of this embodiment is used as a layered material (including film and sheet forms) such as a prepreg or resin composite sheet that serves as an insulating layer for a printed wiring board. When used as such a layered material, the thickness is preferably 5 μm or more, more preferably 10 μm or more. The upper limit of the thickness is preferably 200 μm or less, more preferably 180 μm or less. Note that the thickness of the layered material refers to the thickness including the glass cloth, for example, when the resin composition of this embodiment is impregnated into glass cloth or the like. Materials formed from the resin composition of this embodiment may be used in applications where a pattern is formed by exposure and development, or in applications where exposure and development are not required. They are particularly suitable for applications where exposure and development are not required.

[0198] <<Prepreg>> The prepreg of this embodiment is formed from a substrate (prepreg substrate) and the resin composition of this embodiment. The prepreg of this embodiment can be obtained, for example, by applying the resin composition of this embodiment to the substrate (e.g., by impregnation and / or coating) and then semi-curing by heating (e.g., by drying at 120 to 220°C for 2 to 15 minutes). In this case, the amount of resin composition attached to the substrate, i.e., the amount of resin composition (including hollow silica and filler) relative to the total amount of semi-cured prepreg, is preferably in the range of 20 to 99% by mass, more preferably in the range of 20 to 80% by mass.

[0199] The substrate is not particularly limited as long as it is a substrate used in various printed wiring board materials. Examples of the substrate material 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 examples include woven fabric, nonwoven fabric, roving, chopped strand mat, surfacing mat, etc. These substrates may be used alone or in combination of two or more. Among these substrates, from the viewpoint of dimensional stability, woven fabrics that have been subjected to an ultra-opening treatment and a clogging treatment are preferred. 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 / m ２ The following glass woven fabrics are preferred, and from the viewpoint of moisture absorption and heat resistance, glass woven fabrics surface-treated with epoxy silane, amino silane, or the like are preferred. From the viewpoint of electrical properties, low-dielectric glass cloth made of glass fibers exhibiting a low relative dielectric constant and low dielectric dissipation factor, such as L-glass, NE-glass, NER-glass, or Q-glass, is more preferred. Examples of low-dielectric-constant substrates include substrates having a relative dielectric constant of 5.0 or less (preferably, 3.0 to 4.9). Examples of low-dielectric-tangent substrates include substrates having a dielectric dissipation factor of 0.006 or less (preferably, 0.001 to 0.005). The relative dielectric constant and dielectric dissipation factor are values ​​measured at a frequency of 10 GHz using a perturbation-method cavity resonator.

[0200] <<Metal Foil-Clad Laminate>> The metal foil-clad laminate of this embodiment includes at least one layer formed from the prepreg of this embodiment and a metal foil disposed on one or both sides of the layer formed from the prepreg. Examples of methods for producing the metal foil-clad laminate of this embodiment include a method in which at least one prepreg of this embodiment (preferably two or more prepregs) is disposed, and a metal foil is disposed on one or both sides of the prepreg, followed by laminate molding. More specifically, the laminate can be produced by disposing a metal foil, such as copper or aluminum, on one or both sides of the prepreg and then laminating the prepreg. The number of prepregs is preferably 1 to 10, more preferably 2 to 10, and even more preferably 2 to 9. The metal foil may be any foil suitable for use in printed wiring boards, including, but not limited to, copper foils 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 approximately 1.5 to 70 μm. Furthermore, when copper foil is used as the metal foil, the copper foil preferably has a surface roughness Rz of 0.2 to 4.0 μm, as measured in accordance with JIS B0601:2013. By adjusting the surface roughness Rz to 0.2 μm or more, the copper foil surface roughness becomes appropriate, and the copper foil peel strength tends to be further improved. On the other hand, by adjusting the surface roughness Rz to 4.0 μm or less, the copper foil surface roughness becomes appropriate, and the dielectric loss tangent characteristics of the resulting cured product tend to be further improved. From the viewpoint of the dielectric loss tangent characteristics and copper foil peel strength of the resulting cured product, the copper foil surface roughness Rz is more preferably 0.5 μm or more, even more preferably 0.6 μm or more, particularly preferably 0.7 μm or more, and more preferably 3.5 μm or less, even more preferably 3.0 μm or less, and particularly preferably 2.0 μm or less.

[0201] Examples of laminate molding methods include those commonly used when molding printed wiring board laminates and multilayer boards. More specifically, examples include methods using a multi-stage press, multi-stage vacuum press, continuous molding machine, autoclave molding machine, or the like, at a temperature of about 180 to 350°C, a heating time of about 100 to 300 minutes, and a surface pressure of about 1 to 10 MPa. A multilayer board can also be produced by combining the prepreg of this embodiment with a separately prepared inner layer wiring board for laminate molding. A multilayer board can be produced, for example, by placing copper foil of about 35 μm on both sides of a single prepreg of this embodiment, laminating using the molding method described above, forming an inner layer circuit, and blackening this circuit to form an inner layer circuit board. Then, this inner layer circuit board and the prepreg of this embodiment are alternately arranged one by one, and copper foil is placed on the outermost layer. This laminate molding can be carried out under the above conditions, preferably under vacuum, to produce a multilayer board. The metal foil-clad laminate of this embodiment can be suitably used as a printed wiring board.

[0202] 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 5.7 "Peel Strength" of JIS C6481. There is no particular upper limit to the peel strength, but even if it is 2.00 kN / m or less, the required performance is sufficiently met.

[0203] As described above, the resin composition for electronic materials obtained using the resin composition of the present embodiment (a resin composition including a combination of specific components) can provide a cured product that has low dielectric properties (low dielectric constant, low dielectric dissipation factor, particularly low dielectric constant), excellent cured product appearance, and high-density processability, as well as excellent properties such as moisture absorption heat resistance, peel strength against metal foil, heat resistance, desmear resistance, crack resistance, and low thermal expansion.

[0204] <<Printed Wiring Board>> The printed wiring board of this embodiment includes an insulating layer and a conductor 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 using conventional methods, and the manufacturing method is not particularly limited. An example of a method for manufacturing a printed wiring board is described below. First, a metal foil-clad laminate, such as the copper foil-clad laminate described above, is prepared. Next, the surface of the metal foil-clad laminate is etched to form an inner layer circuit, thereby producing an inner layer substrate. If necessary, the surface of the inner layer circuit of this inner layer substrate is subjected to a surface treatment to increase adhesive strength. Next, a required number of the prepregs described above are stacked on the surface of the inner layer circuit, and metal foil for an outer layer circuit is further laminated on the outside, followed by heating and pressurizing to form an integral mold. In this way, a multilayer laminate is manufactured, in which an insulating layer composed of a substrate 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, this multilayer laminate is subjected to hole drilling for through holes or via holes, and then a plated metal film that connects the inner layer circuit and the metal foil for the outer layer circuit is formed on the wall surface of the hole, and the metal foil for the outer layer circuit is further etched to form the outer layer circuit, thereby producing a printed wiring board.

[0205] The printed wiring board obtained in the above manufacturing example has an insulating layer and a conductor layer formed on the surface of this insulating layer, and the insulating layer contains the resin composition of the present embodiment described above and / or its cured product. That is, the prepreg of the present embodiment described above (for example, a prepreg formed from a base material and the resin composition of the present embodiment impregnated or applied thereto), or the layer formed from the resin composition of the metal foil-clad laminate of the present embodiment described above, serves as the insulating layer of the present embodiment. This embodiment also relates to a semiconductor device including the printed wiring board. For details of the semiconductor device, please refer to paragraphs 0200 to 0202 of JP 2021-021027 A, the contents of which are incorporated herein by reference.

[0206] Furthermore, it is preferable that the insulating layer formed from the cured product of the resin composition of this embodiment has a small surface roughness after roughening treatment. Specifically, the arithmetic mean roughness Ra of the surface of the insulating layer after 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 may be, for example, 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 magnification lens. The non-contact surface roughness meter used is a WYKONT3300 manufactured by Veeco Instruments.

[0207] <<Resin Composite Sheet>> The resin composite sheet of this embodiment includes a support and a layer formed from the resin composition of this embodiment and 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. There are no particular limitations on the method for producing the resin composite sheet, but examples include a method of obtaining a resin composite sheet by applying (coating) a solution obtained by dissolving the resin composition of this embodiment in a solvent to a support and drying the applied solution.

[0208] Examples of the support used here include, but are not limited to, polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, ethylene tetrafluoroethylene copolymer film, and release films obtained by applying a release agent to the surface of these films, organic film substrates such as polyimide film, conductive foils such as copper foil and aluminum foil, glass plates, SUS (Steel Use Stainless) plates, FRP (Fiber-Reinforced Plastics), and other plate-shaped materials.

[0209] Examples of application methods (coating methods) include methods in which a solution of the resin composition of this embodiment dissolved in a solvent is applied to a support using a bar coater, die coater, doctor blade, baker applicator, or the like. Furthermore, after drying, a single-layer sheet can be obtained by peeling or etching the support from a resin composite sheet in which the support and the resin composition are laminated. It should be noted that a single-layer sheet can also be obtained without using a support by supplying a solution of the resin composition of this embodiment dissolved in a solvent into a mold having a sheet-shaped cavity and drying it to form it into a sheet.

[0210] In the production of the monolayer sheet or resin composite sheet of this embodiment, the drying conditions for removing the solvent are not particularly limited. However, because low temperatures tend to leave the solvent in the resin composition, and high temperatures accelerate curing of the resin composition, drying conditions of 20°C to 200°C for 1 to 90 minutes are preferred. The monolayer 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-staged) state as needed. Furthermore, the thickness of the resin layer in the monolayer sheet or resin composite sheet of this embodiment can be adjusted by the concentration and coating thickness of the solution of the resin composition of this embodiment used for coating (coating). While not particularly limited, a thickness of 0.1 to 500 μm is preferred because a thicker coating thickness generally leads to more solvent remaining during drying.

[0211] The present invention will be explained in more detail below with reference to examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be changed as appropriate without departing 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 used in the examples are difficult to obtain due to discontinuation or the like, measurements can be made using other instruments with equivalent performance.

[0212] <Measurement of Weight-Average Molecular Weight 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) using a liquid pump (Shimadzu Corporation, LC-20AD), a differential refractive index detector (Shimadzu Corporation, RID-20A), and GPC columns (Showa Denko K.K., GPC KF-801, 802, 803, 804), with tetrahydrofuran as the solvent, a flow rate of 1.0 mL / min, and a column temperature of 40°C, using a calibration curve prepared using monodisperse polystyrene.

[0213] <Measurement of the average particle size (D50) of hollow silica> Measurement was carried out by a laser diffraction / scattering method using a laser micronsizer (LMS-3000) manufactured by Seishin Enterprise Co., Ltd., in a dry state.

[0214] <Particle density of hollow silica> Measured by gas pycnometer method. Particle density was measured using an Ultrapyc 1200e manufactured by Quantachrome Instruments. Nitrogen gas was used. <Porosity of hollow silica> Calculated from the above particle density. Specifically, the porosity was calculated using the following formula (1) assuming that the density of silica = 2.2 g / cm3. Porosity (%) = [2.2 - (particle density of hollow silica)] / 2.2 × 100 ... formula (1)

[0215] Synthesis Example 1: Synthesis of polyphenylene ether compound (D1) having a terminal carbon-carbon unsaturated double bond Synthesis of bifunctional phenylene ether oligomer A vertical reactor equipped with a stirrer, a thermometer, an air inlet tube, and a baffle plate was charged with CuBr. 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), 670 g of toluene, and 320 g of methanol were charged and dissolved by stirring at a reaction temperature of 40°C. Separately, in advance, in a separate vessel, 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 CuBr２ 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 dissolved with stirring at a reaction temperature of 40°C. Subsequently, while bubbling a mixed gas adjusted to an oxygen concentration of 8% by mixing nitrogen and air into the mixed solution in the polymerization tank, the mixed solution in the dropping tank was added dropwise over 280 minutes and stirred. After completion of the dropwise addition, 700 g of water in which 7.1 g (16 mmol) of tetrasodium ethylenediaminetetraacetate had been dissolved was added to terminate 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 resulting solution was concentrated to 50% by mass using an evaporator, yielding 340 g of phenylene ether resin toluene solution A. The number average molecular weight as calculated on a polystyrene basis by the GPC method was 985, the weight average molecular weight as calculated on a polystyrene basis by the GPC method was 1090, and the hydroxyl equivalent was 478 g / eq.

[0216] <<Synthesis of Modified Polyphenylene Ether Compound>> A reactor equipped with a stirrer, a thermometer, and a reflux condenser was charged with 300 g of the toluene solution A of the phenylene ether resin obtained above, 57.5 g (0.38 mol) of vinylbenzyl chloride (manufactured by AGC Seimi Chemical Co., Ltd., "CMS-P"), 1,200 g of methylene chloride, 5 g (0.037 mol) of benzyldimethylamine, 70 g of pure water, and 63 g of a 30.5 mass% aqueous NaOH solution, and the mixture was stirred at a reaction temperature of 40°C. After stirring for 24 hours, the organic layer was washed with a 1 M aqueous hydrochloric acid solution and then with pure water. The resulting solution was concentrated and added dropwise to methanol to solidify. The solid was collected by filtration and dried in vacuo to obtain 178 g of a polyphenylene ether compound (D1) mainly composed of a compound represented by formula (OP-15). The number average molecular weight (GPC) was 1,200 in terms of polystyrene, the weight average molecular weight (GPC) was 1,840 in terms of polystyrene, the vinyl double bond equivalent was 620 g / eq., and the hydroxyl equivalent was 48,500 g / eq.

[0217] Synthesis Example 2: Synthesis of cyanate ester compound A naphthol aralkyl cyanate ester compound (SNCN) was synthesized based on the description in paragraphs 0074 to 0077 of JP 2018-035327 A.

[0218] Example 1 25 parts by mass of the polyphenylene ether compound (D1) having a terminal carbon-carbon unsaturated double bond obtained in Synthesis Example 1 above, 35 parts by mass of the maleimide compound (ma) shown in the structure below (manufactured by DIC Corporation, "NE-X-9470S", functional group equivalent (maleimide group equivalent) is 450 g / eq., compound represented by formula (M1)), 5 parts by mass of the cyanate ester compound (SNCN) obtained in Synthesis Example 2 above, and a phosphorus-based flame retardant (PX-200, A varnish was obtained by mixing 15 parts by mass of 1,3-phenylenebis(2,6-dixylenylphosphate) manufactured by Daihachi Chemical Industry Co., Ltd., 20 parts by mass of a thermoplastic elastomer (C1) (Dynaron 9901P manufactured by ENEOS Materials Corporation, styrene compound unit content: 53% by mass), and 40 parts by mass of hollow silica (A1) (porosity: 32%, average particle size (D50): 4.0 μm), and diluting the mixture with methyl ethyl ketone to a solids content of 65% by mass. The blending amounts of each component described above indicate values ​​based on the solids content.

[0219] Maleimide compound (ma)

[0220] <Production of Metal Foil-Clad Laminate> The varnish obtained above was applied to an NE glass woven fabric (N3313 S101S, manufactured by Nitto Boseki Co., Ltd.) by impregnation, and the fabric was dried by heating at 155°C for 5 minutes to obtain a prepreg (thickness 0.1 mm) containing 70% by volume of resin composition. The properties of the NE glass woven fabric used are as follows: IPC applicable grade: 3313, density (counts / 25 mm) lengthwise: 60, density (counts / 25 mm) widthwise: 62, thickness (mm): 0.075, mass (g / m ２ ) : 83 One, eight or twelve of the obtained prepregs were stacked, and 12 μm thick electrolytic copper foil (3EC-M3-VLP, manufactured by Mitsui Mining & Smelting Co., Ltd.) was placed on both sides, and a pressure of 30 kgf / cm was applied. ２The laminate was then vacuum pressed at 220° C. for 120 minutes to obtain copper foil-clad laminates with insulating layer thicknesses of 0.1 mm, 0.8 mm, or 1.2 mm.

[0221] <Measurement and Evaluation Methods> <Dielectric Properties> The copper foil on both sides of the copper foil-clad laminate (insulating layer thickness 0.8 mm) obtained as described above was etched away, and then cut into 1.0 mm x 100 mm x 0.8 mm (downsized). The evaluation sample was dried at 120°C for 60 minutes. The dielectric constant (Dk) and dielectric loss tangent (Df) at a frequency of 10 GHz were measured by the cavity resonator perturbation method in accordance with JIS C218:2007. The cavity resonator used was manufactured by EM Lab, and the network analyzer used was a P5005A manufactured by Keysight Technologies. The measurement temperature was 23°C. The dielectric properties were evaluated as follows. <<Dielectric Constant (Dk)>> A: 3.0 or less B: More than 3.0 <<Dielectric Loss Tangent (Df)>> A: 0.0022 or less B: More than 0.0022 and 0.0025 or less C: More than 0.0025

[0222] <Appearance after curing> After the copper foil on both sides of the copper foil-clad laminate (insulating layer thickness: 0.8 mm) obtained as described above was removed by etching, the appearance was evaluated visually. The evaluation was judged by majority vote of five experts and rated as follows: A: No appearance defect B: Appearance defect

[0223] <CTE (X)> The coefficient of linear thermal expansion (CTE) was determined by the TMA method (Thermo-Mechanical Analysis) specified in JIS C 6481 5.19 as follows. Specifically, the copper foil on both sides of the copper foil-clad laminate (insulating layer thickness 0.1 mm) obtained above was removed by etching, and the evaluation sample was cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. Using a thermomechanical analyzer (TA Instruments, TMA Q-400), the temperature was raised from 30 ° C. to 320 ° C. at a rate of 10 ° C. per minute, and the in-plane linear thermal expansion coefficient (CTE (X)) (unit: ppm / ° C.) from 30 ° C. to 300 ° C. was measured. The measurement direction was the longitudinal direction (Warp) of the glass cloth of the laminate. The ppm is a volume ratio. Other details are in accordance with the above-mentioned JIS C 6481 5.19. Evaluation was made as follows: S: 5 ppm / °C or less A: More than 5 ppm / °C and 9 ppm / °C or less B: More than 9 ppm / °C and 10 ppm / °C or less C: More than 10 ppm / °C

[0224] <Drilling processability> The copper foil clad laminate (insulating layer thickness 1.2 mm) obtained as described above was laminated from the bottom with a backup board, a copper foil clad laminate (two sheets), and an entry sheet to prepare an evaluation sample. This sample was processed 5000 times from the top of the sample under the following drilling processing conditions, and the positional deviation between the hole position on the back surface of the copper foil clad laminate and the specified coordinates was measured using a hole analyzer (manufactured by Via Mechanics Co., Ltd.). The positional deviation for each drilled hole was measured in total, and the maximum value was calculated. Processing machine: Via Mechanics Co., Ltd. ND-1 V212 Entry sheet: Mitsubishi Gas Chemical Co., Inc. LE-R12F3 Backup board: Nippon Decorax Co., Ltd. SPB-W Drill bit: Union Tool Co., Ltd. KCW V103VWU 0.15 x 3.5 It was evaluated as follows. A: Less than 35 μm B: 35 μm or more and less than 40 μm C: 40 μm or more

[0225] Example 2 The same procedure as in Example 1 was carried out except that the content of hollow silica (A1) was changed to 200 parts by mass.

[0226] Example 3 The same procedure as in Example 1 was carried out except that the content of hollow silica (A1) was changed to 100 parts by mass.

[0227] Example 4 The same procedures as in Example 1 were performed, except that the content of the polyphenylene ether compound (D1) was changed to 40 parts by mass, the content of the maleimide compound (ma) was changed to 15 parts by mass, 10 parts by mass of the maleimide compound (mb) (biphenylaralkyl maleimide, manufactured by Nippon Kayaku Co., Ltd., compound represented by formula (M3)) was blended, the cyanate ester compound (SNCN) was not blended, and the content of the hollow silica (A1) was changed to 100 parts by mass.

[0228] Comparative Example 1 The same procedure as in Example 1 was carried out except that 40 parts by mass of hollow silica (A1) was changed to 135 parts by mass of solid silica (A2) (Admatechs Co., Ltd., SC4500SQ).

[0229] Comparative Example 2 The same procedure as in Example 1 was carried out except that the hollow silica (A1) was not added.

[0230] Comparative Example 3 The same procedure as in Example 1 was carried out except that the content of hollow silica (A1) was changed to 300 parts by mass.

[0231] Comparative Example 4 The same procedure as in Example 4 was carried out except that 100 parts by mass of hollow silica (A1) was changed to 135 parts by mass of solid silica (A2).

[0232]

Claims

1. A resin composition comprising hollow silica (A) and a thermosetting resin (B), wherein the content of hollow silica (A) in the resin composition is 10 to 250 parts by mass per 100 parts by mass of resin solids, and the resin composition is impregnated into an NE glass cloth so that the content of the resin composition is 70 volume %, and the prepreg is heated and dried at 155°C for 5 minutes to obtain a copper foil-clad laminate. Eight prepregs each having a thickness of 0.1 mm are stacked, and electrolytic copper foils each having a thickness of 12 μm are placed on both sides of the laminate and pressed to obtain a copper foil-clad laminate. The copper foils on both sides are then removed by etching to obtain a copper foil-clad laminate. The dielectric loss tangent at a frequency of 10 GHz measured by a cavity resonator perturbation method in accordance with JIS C218:2007 is 0.0025 or less.

2. The resin composition according to claim 1, wherein the relative dielectric constant of the 0.8 mm thick sample is 3.0 or less at a frequency of 10 GHz, as measured by a cavity resonator perturbation method in accordance with JIS C218:2007.

3. The resin composition according to claim 1, wherein the resin composition is impregnated into NE glass cloth so that the resin composition content is 70% by volume, and the prepreg is heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. Electrolytic copper foil of 12 μm in thickness is placed on both sides of the prepreg and pressed to obtain a copper foil-clad laminate, from which the copper foil on both sides is removed by etching, and the sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. When the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C, the thermal expansion coefficient in the plane direction at 60 to 120°C is 10 ppm / °C or less.

4. The resin composition according to claim 1, wherein the 0.8 mm thick sample has a relative dielectric constant of 3.0 or less at a frequency of 10 GHz as measured by a cavity resonator perturbation method in accordance with JIS C218:2007, and the resin composition is impregnated into an NE glass cloth so that the resin composition content is 70 volume %, and heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. The prepreg is then pressed to obtain a copper foil-clad laminate, from which the copper foil on both sides is removed by etching, and the sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm. When the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C, the thermal expansion coefficient in the plane direction at 60 to 120°C is 10 ppm / °C or less.

5. The resin composition according to any one of claims 1 to 4, wherein the thermosetting resin (B) comprises an aromatic vinyl resin (D) and a maleimide compound (E).

6. The resin composition according to any one of claims 1 to 4, further comprising a thermoplastic elastomer (C).

7. The resin composition according to claim 6, wherein the thermoplastic elastomer (C) contains a styrene compound unit and one or more units selected from the group consisting of a butadiene unit, an isoprene unit, a hydrogenated butadiene unit, and a hydrogenated isoprene unit, and the content of the styrene compound units in the thermoplastic elastomer (C) is 55 mass% or less of the entire thermoplastic elastomer (C).

8. The resin composition according to claim 6, wherein the content of the thermoplastic elastomer (C) in the resin composition is 5 to 30 parts by mass per 100 parts by mass of resin solids.

9. The resin composition according to claim 5, wherein the aromatic vinyl resin (D) comprises at least one member selected from the group consisting of a polymer having a structural unit represented by formula (V) and a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond. (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.) 10. The resin composition according to claim 9, wherein the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond comprises a polyphenylene ether compound represented by formula (OP). (In formula (OP), X represents an aromatic group, -(Y-O) ｎ１ - represents a polyphenylene ether structure, n1 represents an integer of 1 to 100, and n2 represents an integer of 1 to 4. Rx is a group represented by the formula (Rx-1). (In formula (Rx-1), R １ , R ２ , and R ３ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * is a bonding site with an oxygen atom. Each Mc independently represents a hydrocarbon group having 1 to 12 carbon atoms. z represents an integer of 0 to 4. r represents an integer of 0 to 6.

11. The resin composition according to claim 5, wherein the content of the aromatic vinyl resin (D) in the resin composition is 5 to 95 parts by mass per 100 parts by mass of resin solids.

12. The resin composition according to claim 5, wherein the maleimide compound (E) comprises one or more compounds selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M3), and a compound represented by formula (M5). (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ R each independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ Each independently represents a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4- to 6-membered alicyclic group. 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 of R independently represents a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ R each independently represents a hydrogen atom or an organic group. 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.) (In formula (M3), R ５５ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; ５ represents an integer of 1 or more and 10 or less.) (In formula (M5), R ５８ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R ５９ each independently represents a hydrogen atom or a methyl group; n ６ represents an integer of 1 or more.) 13. The 0.8 mm thick sample has a relative dielectric constant of 3.0 or less at a frequency of 10 GHz measured by a cavity resonator perturbation method in accordance with JIS C218:2007; the resin composition is impregnated into an NE glass cloth so that the resin composition content is 70 volume %, and the prepreg is heated and dried at 155°C for 5 minutes to obtain a 0.1 mm thick prepreg. The prepreg is pressed by placing 12 μm thick electrolytic copper foil on both sides of the prepreg, and the copper foil on both sides is removed by etching from the copper foil clad laminate. The sample is cut (downsized) to 4.5 mm x 10 mm x 0.1 mm, and the thermal expansion coefficient in the plane direction at 60 to 120°C is 10 ppm / °C or less when the sample is measured at a heating rate of 10°C per minute from 30°C to 340°C; the thermosetting resin (B) contains an aromatic vinyl resin (D) and a maleimide compound (E), and further contains a thermoplastic elastomer (C); the thermoplastic elastomer (C) comprises a styrene compound unit and one or more selected from the group consisting of a butadiene unit, an isoprene unit, a hydrogenated butadiene unit, and a hydrogenated isoprene unit, the content of the styrene compound unit in the thermoplastic elastomer (C) is 55 mass% or less of the entire thermoplastic elastomer (C), the content of the thermoplastic elastomer (C) in the resin composition is 5 to 30 mass parts per 100 mass parts of resin solid content, the aromatic vinyl resin (D) comprises one or more selected from the group consisting of a polymer having a structural unit represented by formula (V) and a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond comprises a polyphenylene ether compound represented by formula (OP), the content of the aromatic vinyl resin (D) in the resin composition is 5 to 95 mass parts per 100 mass parts of resin solid content, The resin composition according to claim 1, wherein the maleimide compound (E) comprises one or more selected from the group consisting of a compound represented by formula (M1), a compound represented by formula (M3), and a compound represented by formula (M5). (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.) (In formula (OP), X represents an aromatic group, -(Y-O) ｎ１ - represents a polyphenylene ether structure, n1 represents an integer of 1 to 100, and n2 represents an integer of 1 to 4. Rx is a group represented by the formula (Rx-1). (In formula (Rx-1), R １ , R ２ , and R ３ each independently represents a hydrogen atom, an alkyl group, an alkenyl group, or an alkynyl group. * is a bonding site with an oxygen atom. Each Mc independently represents a hydrocarbon group having 1 to 12 carbon atoms. z represents an integer of 0 to 4. r represents an integer of 0 to 6. (In formula (M1), R Ｍ１ , R Ｍ２ , R Ｍ３ , and R Ｍ４ R each independently represents a hydrogen atom or an organic group. Ｍ５ and R Ｍ６ Each independently represents a hydrogen atom or an alkyl group. Ｍ represents a divalent aromatic group. A is a 4- to 6-membered alicyclic group. 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 of R independently represents a hydrogen atom or an alkyl group. Ｍ１１ , R Ｍ１２ , R Ｍ１３ , and R Ｍ１４ R each independently represents a hydrogen atom or an organic group. 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.) (In formula (M3), R ５５ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; ５ represents an integer of 1 or more and 10 or less.) (In formula (M5), R ５８ each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, or a phenyl group; R ５９ each independently represents a hydrogen atom or a methyl group; n ６ represents an integer of 1 or more.) 14. The resin composition according to any one of claims 1 to 4 and 13, further comprising a flame retardant.

15. The resin composition according to claim 14, wherein the flame retardant comprises a phosphorus-based flame retardant.

16. A cured product of the resin composition according to any one of claims 1 to 4 and 13.

17. A prepreg formed from a substrate and the resin composition according to any one of claims 1 to 4 and 13.

18. A metal foil clad laminate comprising at least one prepreg according to claim 17 and a metal foil disposed on one or both sides of the prepreg.

19. A resin composite sheet comprising a support and a layer formed from the resin composition according to any one of claims 1 to 4 and 13, disposed on a surface of the support.

20. A printed wiring board comprising an insulating layer and a conductor layer disposed on a surface of the insulating layer, the insulating layer comprising a layer formed from a resin composition according to any one of claims 1 to 4 and 13.

21. A semiconductor device comprising the printed wiring board according to claim 20.

Images