Resin composition, resin sheet, and multilayer body

Abstract

To provide a resin composition, a resin sheet, and a multilayer body. A resin composition according to the present disclosure contains a thermosetting compound (A) having a melting point of 30°C or less and a 5% weight loss temperature of 150°C or more and a thermosetting compound (B) (excluding compounds that fall under the category of the thermosetting compound (A)) capable of polymerizing with the thermosetting compound (A).

Description

Resin composition, resin sheet, and multilayer body

[0001] The present invention relates to a resin composition, a resin sheet, and a multilayer body.

[0002] In recent years, semiconductor packages widely used in electronic devices, communication devices, personal computers, etc. have become more functional, thinner, and smaller, and as a result, the integration and high-density packaging of each component have been accelerating. Accordingly, the properties required of printed wiring boards for semiconductor packages, also known as semiconductor package substrates and semiconductor element mounting substrates, have become increasingly strict. Patent Document 1 is an example in which a resin sheet for use in printed wiring boards, etc., has been investigated. Patent Document 1 discloses a resin sheet including a support and a layer containing a resin composition disposed on the surface of the support, wherein the resin composition contains a cyanate ester compound and / or a phenol compound, and an epoxy compound and / or a maleimide compound, and at least one compound selected from the group consisting of the cyanate ester compound, the phenol compound, the epoxy compound, and the maleimide compound contains a compound having a biphenyl skeleton, and when the resin composition contains an inorganic filler, the content of the inorganic filler is 60 parts by mass or less relative to 100 parts by mass of resin solids in the resin composition, the Vickers hardness (HV0.01) of a cured product of the resin composition is 10 or more and 19 or less, and the thickness of the layer containing the resin composition is 2 μm or more and 20 μm or less.

[0003] International Publication No. 2021 / 125121

[0004] Here, an example of the resin sheet configuration is a multilayer body in which a resin sheet is laminated on the surface of a glass core in a semiconductor package substrate, etc. Because such a multilayer body does not contain a glass cloth, flexibility is required to prevent the resin sheet from cracking or peeling during the manufacturing process of the printed wiring board. Meanwhile, in addition to low dielectric properties (Dk and / or Df, particularly Dk) for thin and fine wiring, low thermal expansion (low CTE) for warpage suppression is also required. Flexibility, low dielectric properties for thin and fine wiring, and low thermal expansion for warpage suppression are also required for resin sheets laminated on the surface of an organic resin core and for resin sheets in general printed wiring boards such as rigid and flexible substrates. The present invention aims to solve this problem by providing a resin composition, a resin sheet, and a multilayer body that can provide a resin sheet that has flexibility in a B-stage state and excellent low thermal expansion when further cured from the B-stage state to a C-stage state.

[0005] In light of the above-mentioned problems, the present inventors have conducted extensive research and found that the above-mentioned problems can be solved by blending a thermosetting compound (A) having a melting point of 30°C or lower and a 5% weight loss temperature of 150°C or higher with a thermosetting compound (B) capable of undergoing a polymerization reaction with the thermosetting compound (A). Specifically, the above-mentioned problems have been solved by the following means: [1] A resin composition comprising a thermosetting compound (A) having a melting point of 30°C or lower and a 5% weight loss temperature of 150°C or higher, and a thermosetting compound (B) capable of undergoing a polymerization reaction with the thermosetting compound (A) (excluding compounds corresponding to the thermosetting compound (A)). [2] The resin composition according to [1], wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond. [3] The resin composition according to [1] or [2], wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond is one or more selected from the group consisting of a compound having two or more (meth)acryloyl groups in its molecule and a compound having two or more (meth)allyl groups in its molecule. [4] The resin composition according to any one of [1] to [3], wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond is a compound having two or more methacryloyl groups in its molecule. [5] The resin composition according to any one of [1] to [4], wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond comprises a compound represented by Formula (A-1) and / or a compound represented by Formula (A-2). Formula (A-1) (In formula (A-1), R Ａ represents a hydrogen atom or a substituent. (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａrepresents a hydrogen atom or a substituent.) [6] The resin composition according to any one of [1] to [5], wherein the content of the thermosetting compound (A) is 2 to 30 parts by mass per 100 parts by mass of the resin solid content in the resin composition. [7] The resin composition according to any one of [1] to [6], wherein the thermosetting compound (B) comprises at least one selected from the group consisting of an epoxy compound, a cyanate ester compound, a compound (b) having a terminal carbon-carbon unsaturated double bond, a maleimide compound, and a nadimide compound. [8] The resin composition according to any one of [1] to [7], wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) comprises a maleimide compound. [9] The resin composition according to any one of [1] to [8], wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) includes a compound represented by formula (M1) and / or a compound having a structure represented by formula (M7). (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 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, and t represents an integer of 0 to 4. １ X per benzene ring to which １is 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. * represents a bonding site.)

[10] The resin composition according to any one of [1] to [9], wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) includes a maleimide compound, and the content of the compound having a terminal carbon-carbon unsaturated double bond is 5 to 50 parts by mass per 100 parts by mass of the total of the compound having a terminal carbon-carbon unsaturated double bond and the maleimide compound.

[11] The resin composition according to any one of [1] to

[10] , further including an elastomer containing a polymer block (a1) including a styrene compound unit having a radical-reactive group and a conjugated diene compound unit.

[12] The resin composition according to

[11] , wherein the conjugated diene compound unit is hydrogenated and / or partially hydrogenated.

[13] The resin composition according to

[11] or

[12] , wherein the content of the elastomer is 0.5 to 30 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[14] The resin composition according to any one of [1] to

[13] , wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond is a compound represented by formula (A-1) and / or a compound represented by formula (A-2) and includes a compound having two carbon-carbon unsaturated double bonds in one molecule, and the thermosetting compound (B) comprises a compound represented by formula (M1) and / or a compound having a structure represented by formula (M7), and further comprises an elastomer containing a polymer block (a1) containing a styrene compound unit having a radical reactive group and a conjugated diene compound unit, and the conjugated diene compound unit is hydrogenated and / or partially hydrogenated. Formula (A-1) (In formula (A-1), R Ａ represents a hydrogen atom or a substituent. (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａ represents a hydrogen atom or a substituent. (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 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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 ６one 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, and t represents an integer of 0 to 4. １ X per benzene ring to which １is the average value of the number of substitutions, and represents a number of 0 to 4, p represents an integer of 1 to 3, q ​​represents an integer of 0 to 4, and k represents an integer of 1 to 100. * represents a bonding position.)

[15] The resin composition according to any one of [1] to

[14] , further comprising a radical polymerization initiator.

[16] The resin composition according to any one of [1] to

[14] , further comprising an imidazole-based curing accelerator.

[17] The resin composition according to any one of [1] to

[16] , wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) includes a maleimide compound, the content of the compound having a terminal carbon-carbon unsaturated double bond is 5 to 50 parts by mass relative to 100 parts by mass of the total of the compound having a terminal carbon-carbon unsaturated double bond and the maleimide compound, the content of the thermosetting compound (A) is 2 to 30 parts by mass relative to 100 parts by mass of resin solid content in the resin composition, the resin composition further includes an elastomer including a polymer block (a1) including a styrene compound unit having a radical reactive group and a conjugated diene compound unit, the content of the elastomer is 0.5 to 30 parts by mass relative to 100 parts by mass of resin solid content in the resin composition, the resin composition further includes a radical polymerization initiator, and the resin composition further includes an imidazole-based curing accelerator.

[18] The resin composition according to

[17] , wherein the compound having a terminal carbon-carbon unsaturated double bond is a compound represented by formula (A-1) and / or a compound represented by formula (A-2), and includes a compound having two carbon-carbon unsaturated double bonds in one molecule, the thermosetting compound (B) includes a compound represented by formula (M1) and / or a compound having a structure represented by formula (M7), and the conjugated diene compound unit is a hydrogenated and / or partially hydrogenated product of Formula (A-1). (In formula (A-1), R Ａ represents a hydrogen atom or a substituent. (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａ represents a hydrogen atom or a substituent. (In formula (M1), R Ｍ１ , RＭ２ , 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 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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, １are 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, and t represents an integer of 0 to 4. １ X per benzene ring to which １is 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. * represents a bonding position.)

[19] A resin sheet formed from the resin composition according to any one of [1] to

[18] .

[20] The resin sheet according to

[19] , which is in a B-stage state.

[21] A multilayer body comprising a base film, a resin sheet, and a cover film laminated in the stated order, and the resin sheet is a layer in a B-stage state formed from the resin composition according to any one of [1] to

[18] .

[22] The multilayer body according to

[21] , wherein the thickness of the layer in a B-stage state is 20 to 50 μm.

[23] A multilayer body having a glass core and an insulating resin layer, the insulating resin layer being a layer in a B-stage state formed from a thermosetting resin composition, wherein when a cylindrical mandrel bending test is performed with the insulating resin layer having a thickness of 30 μm, the maximum diameter of a cylinder at which at least one of cracking and peeling of the insulating resin layer is observed is 30 mm or less, and the length of the crack when a load is applied to the insulating resin layer with a micro Vickers hardness tester is 1500 μm or less.

[24] The multilayer body according to

[23] , wherein the thermosetting resin composition is the resin composition according to any one of [1] to

[18] .

[25] The multilayer body according to any one of

[21] to

[24] , wherein the thickness of the layer in the B-stage state is 20 to 50 μm.

[26] A multilayer body according to any one of

[21] to

[25] , wherein the layer in the B-stage state is further cured.

[27] The resin composition according to any one of [1] to

[18] , which is used for forming an inter-wiring insulating layer that insulates wiring layers for connecting semiconductor chips.

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

[18] .

[29] A semiconductor device comprising the printed wiring board according to

[28] .

[0006] The present invention has made it possible to provide a resin composition, a resin sheet, and a multilayer body that can provide a resin sheet that has flexibility when the resin sheet is in a B-stage state and has excellent low thermal expansion properties when further cured from the B-stage state to a C-stage state.

[0007] 1 is a cross-sectional schematic view showing an example of a multilayer body according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional schematic view showing an example of a multilayer body according to a second embodiment of the present invention.

[0008] Hereinafter, a detailed description will be given of an embodiment of the present invention (hereinafter simply referred to as "the present embodiment"). The following embodiment is merely 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 the term "to" include the upper and lower 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 specify whether it is 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 (an unsubstituted alkyl group) but also an alkyl group that has a substituent (a substituted alkyl group). In this specification, when a notation that does not specify whether it is substituted or unsubstituted is used, unsubstituted is preferred. In this specification, the term "dielectric constant" refers to the ratio of the dielectric constant of a substance to the dielectric constant of a vacuum. In this specification, the term "dielectric constant" may also be simply referred to as "dielectric constant." Furthermore, in this specification, the term "dielectric constant" refers to the dielectric constant at a frequency of 10 GHz measured according to the cavity resonance perturbation method, unless otherwise specified. In this specification, "(meth)acrylic" refers to both or either of acrylic and methacrylic. "(meth)allyl" refers to both or either of allyl and methallyl. When the measurement method, etc. of the specifications shown in this specification differ depending on the year, they are based on the specifications as of January 1, 2024, unless otherwise specified.

[0009] In this specification, the resin solid content refers to components excluding fillers and solvents, and is intended to include the thermosetting compound (A), the thermosetting compound (B), other thermosetting compounds that are blended as necessary, and other resin additive components (additives such as flame retardants, etc.). The scales of Figures 1 and 2 may not be in accord with reality.

[0010] The resin composition of this embodiment is characterized by containing a thermosetting compound (A) having a melting point of 30°C or lower and a 5% weight loss temperature of 150°C or higher, and a thermosetting compound (B) capable of polymerizing with the thermosetting compound (A) (excluding compounds corresponding to the thermosetting compound (A)). This configuration results in a resin composition capable of providing a resin sheet (and even a multilayer body having a glass core and a resin sheet) that is flexible when the resin sheet is in a B-stage state and exhibits excellent low expansion when further cured from the B-stage state to a C-stage state. In this specification, the term "B-stage" includes an intermediate curing stage of the reaction of the thermosetting compound and a semi-cured product formed from the resin composition that is tack-free and appears cured. Therefore, it is distinguished from a product that is further cured from a B-stage state (e.g., a fully cured state or a C-stage state). In this specification, unless otherwise specified, "cured product" refers to a product that is further cured from a B-stage state.

[0011] In this embodiment, a thermosetting compound (A) having a melting point of 30°C or lower and a 5% weight loss temperature of 150°C or higher is used. By using a thermosetting compound (A) that is liquid at room temperature or becomes liquid upon slight heating, a resin sheet in a B-stage state formed from the resin composition of this embodiment is presumably improved in low elasticity and flexibility, and in toughness as a sheet (film). Meanwhile, the thermosetting compound (B) is capable of polymerization reaction with the thermosetting compound (A). In the C-stage state, the thermosetting compound (A) and the thermosetting compound (B) polymerize and sufficiently harden, presumably achieving a low coefficient of thermal expansion. In particular, since the thermosetting compound (A) has a high 5% weight loss temperature of 150°C or higher, it does not volatilize during the process of achieving the C-stage state, and therefore, the above-mentioned effect is presumably fully exerted. In the present invention, a compound that corresponds to the thermosetting compound (A) and also corresponds to the thermosetting compound (B) is classified as the thermosetting compound (A).

[0012] Hereinafter, the embodiments of the present invention will be described in detail. However, the explanation of the constituent elements described below is an example of an embodiment of the present invention, and the present invention is not limited to these contents.

[0013] <Thermosetting Compound (A)> The resin composition of this embodiment contains a thermosetting compound (A) having a melting point of 30°C or less and a 5% weight loss temperature of 150°C or more. Having a melting point of not more than the upper limit of this range tends to further improve the flexibility of the resin sheet in a B-stage state. The melting point of the thermosetting compound (A) is a value measured according to a visual method (JIS K6220). The melting point of the thermosetting compound (A) is preferably 28°C or less, more preferably 25°C or less, even more preferably 20°C or less, still more preferably 15°C or less, and preferably 5°C or more, more preferably 0°C or more, and even more preferably -30°C or more. Having a melting point of not less than the lower limit of this range tends to further improve the flexibility of the resin sheet in a B-stage state. When the resin composition of this embodiment contains two or more thermosetting compounds (A), the melting point refers to the melting point of the component with the highest melting point.

[0014] The 5% weight loss temperature of the thermosetting compound (A) refers to the temperature at which a sample is heated in air from room temperature (25°C) at a rate of 10°C / min and loses 5% by mass, assuming the initial mass of the sample to be 100% by mass. The 5% weight loss temperature of the thermosetting compound (A) is preferably 160°C or higher, more preferably 180°C or higher, even more preferably 200°C or higher, and even more preferably 250°C or higher. When the 5% weight loss temperature is equal to or higher than the lower limit, the heat resistance of the resulting cured product tends to be improved. The upper limit of the 5% weight loss temperature is not particularly limited, but 350°C or lower is practical. The 5% weight loss temperature is measured according to the description in the examples below. When the resin composition of this embodiment contains two or more thermosetting compounds (A), the 5% weight loss temperature is the value of the component with the lowest 5% weight loss temperature.

[0015] The molecular weight of the thermosetting compound (A) is not particularly limited, but is preferably 100,000 or less, more preferably 50,000 or less, even more preferably 10,000 or less, even more preferably 5,000 or less, and even more preferably 3,000 or less. Depending on the application, it may be 2,000 or less, 1,500 or less, 1,000 or less, 800 or less, 700 or less, 600 or less, or 500 or less. It is also preferably 100 or more, more preferably 150 or more, even more preferably 200 or more, even more preferably 250 or more, and even more preferably 300 or more. By having the molecular weight below the upper limit, the viscosity of the resin composition is suppressed, and the laminate moldability tends to be better. Furthermore, by having the molecular weight above the lower limit, the viscosity of the resin composition is suppressed, and the flow properties of the resin composition when processed into a resin sheet tend to be further improved. When the resin composition of the present embodiment contains two or more types of thermosetting compounds (A), the molecular weight is a weighted average value.

[0016] The thermosetting compound (A) preferably contains a compound having a terminal carbon-carbon unsaturated double bond. Examples of the carbon-carbon unsaturated double bond include a vinyl group, a (meth)acryloyl group, a (meth)allyl group, and a vinyl ether group. A (meth)acryloyl group and / or a (meth)allyl group is preferred, and a methacryloyl group and / or an allyl group is more preferred. Furthermore, the compound having a terminal carbon-carbon unsaturated double bond preferably has two or more carbon-carbon unsaturated double bonds in one molecule, more preferably two to six, even more preferably two to four, and even more preferably two to three, and may even have two. The use of a bifunctional compound allows for an appropriate crosslink density of the resin solid content, which tends to further improve flexibility after curing and also tends to lower the thermal expansion coefficient. In this embodiment, the thermosetting compound (A) is more preferably one or more selected from the group consisting of compounds having two or more (preferably two) (meth)acryloyl groups in the molecule and compounds having two or more (preferably two) (meth)allyl groups in the molecule, even more preferably one or more selected from the group consisting of compounds having two or more methacryloyl groups in the molecule and compounds having two or more allyl groups in the molecule, and even more preferably a compound having two or more methacryloyl groups in the molecule.

[0017] A first embodiment of the thermosetting compound (A) is a compound represented by formula (A-1). (In formula (A-1), R Ａ represents a hydrogen atom or a substituent.

[0018] In formula (A-1), R Ａ represents a substituent, and is more preferably a substituent having a formula weight of 15 to 350.

[0019] R Ａis a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 2 to 22 carbon atoms, and is preferably an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 2 to 22 carbon atoms. By using 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 that can give a cured product having high toughness. 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 be 12 or more, but preferably 18 or less. This improves the resin flow properties of the resin composition, and improves circuit filling properties when using the resin composition of this embodiment to produce a multilayer circuit board or the like.

[0020] 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.

[0021] Specific examples of the compound represented by formula (A-1) 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.

[0022] Furthermore, commercially available compounds represented by formula (A-1) can also be used. Examples of commercially available compounds include, but are not limited to, L-DAIC manufactured by Shikoku Chemical Industries Co., Ltd., and P-DAIC having a phosphorus-based substituent, manufactured by Shikoku Chemical Industries Co., Ltd. Examples of triallyl isocyanurate include TAIC manufactured by Shinryo Corporation.

[0023] A second embodiment of the thermosetting compound (A) is a compound represented by formula (A-2). (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａ represents a hydrogen atom or a substituent.

[0024] Cy １ is preferably selected from the group consisting of norbornane, decalin, perhydroazulene, adamantane, and tricyclodecane, and more preferably tricyclodecane. Each L is independently a single bond or a linking group, and is a single bond or -CH ２ It is preferably a group selected from the group consisting of -, -O-, -NH-, -S-, -S(=O)-, and a group consisting of a combination of two or more of these, and is preferably a single bond or -CH ２ More preferably, R is a group selected from the group consisting of -, -O-, and a combination of two or more thereof. Ａ is preferably a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 2 to 22 carbon atoms, and more preferably a hydrogen atom. Preferred examples of the alkyl group having 1 to 22 carbon atoms or the alkenyl group having 2 to 22 carbon atoms include R ＡExamples of the compound represented by formula (A-2) include the following. Each Po is independently a carbon-carbon unsaturated double bond group, and is preferably a (meth)acryloyl group, a (meth)allyl group, or a vinyl group, more preferably a (meth)acryloyl group, and even more preferably a methacryloyl group. Examples of the compound represented by formula (A-2) include the following compounds. It goes without saying that the present invention is not limited to these.

[0025] Formula (A-2-1)

[0026] The compound represented by formula (A-2-1) may be commercially available. Examples of commercially available compounds include, but are not limited to, NK Ester DCP manufactured by Shin-Nakamura Chemical Co., Ltd.

[0027] A third embodiment of the thermosetting compound (A) is a compound represented by formula (A-3). (In formula (A-3), R １ and R ２ are each independently a group containing a (meth)allyl group, and R ３ and R ４ each independently represents a hydrogen atom, an alkyl group, or an aryl group.

[0028] In formula (A-3), R １ and R ２ are each independently a group containing a (meth)allyl group, more preferably a (meth)allyl group, and even more preferably an allyl group. ３ and R ４ each independently represents a hydrogen atom, an alkyl group, or an aryl group (preferably a phenyl group), more preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and even more preferably a hydrogen atom. １ and R ２ is an allyl group, and R ３ and R ４ is preferably a hydrogen atom (1,3,4,6-tetraarylglycoluril).

[0029] The compound represented by formula (A-3) may be commercially available, and examples thereof include, but are not limited to, TA-G manufactured by Shikoku Chemicals Corporation.

[0030] The content of the thermosetting compound (A) in the resin composition of this embodiment is preferably 2 parts by mass or more, more preferably 4 parts by mass or more, even more preferably 6 parts by mass or more, even more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, per 100 parts by mass of resin solids, and may be 12 parts by mass or more, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 22 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 18 parts by mass or less. By setting the content of the thermosetting compound (A) to the above lower limit or more, the low thermal expansion (low CTE) of the obtained cured product and the flexibility of the resin sheet in a B-stage state tend to be further improved. Furthermore, by setting the content to the above upper limit or less, the heat resistance of the obtained cured product tends to be further improved. The resin composition of this embodiment may contain only one type of thermosetting compound (A), or may contain two or more types. When two or more types of thermosetting compounds (A) are contained, it is preferable that the total amount is within the above range.

[0031] In the resin composition of this embodiment, the thermosetting compound (A) preferably includes a compound represented by formula (A-1) and / or a compound represented by formula (A-2), which contains two carbon-carbon unsaturated double bonds in one molecule. This configuration tends to provide a cured product with greater flexibility. In particular, it is preferable to use a compound represented by formula (A-1) and / or a compound represented by formula (A-2), which contains two carbon-carbon unsaturated double bonds in one molecule, and a compound represented by formula (M1) and / or a maleimide compound (M7), as the thermosetting compound (B), described below. This configuration tends to provide a cured product with lower dielectric constant and greater flexibility. Furthermore, the resin composition preferably includes an elastomer containing a polymer block (a1) containing a styrene compound unit having a radical-reactive group and a conjugated diene compound unit, wherein the conjugated diene compound unit is hydrogenated and / or partially hydrogenated. In such a resin composition, the compound represented by formula (A-1) and / or the compound represented by formula (A-2), which has two carbon-carbon unsaturated double bonds in one molecule, and the compound represented by formula (M1) and / or the maleimide compound (M7) are sufficiently compatible, resulting in a resin composition that can provide a cured product with low dielectric constant, low CTE, and excellent flexibility. Furthermore, the resin composition of this embodiment preferably does not contain a compound represented by formula (A-1) and / or the compound represented by formula (A-2), which has three carbon-carbon unsaturated double bonds in one molecule. By adopting such a configuration, the thermal expansion coefficient of the resulting cured product can be further reduced. This is presumably due to the shorter distance between crosslinking points.

[0032] <Thermosetting Compound (B)> The resin composition of the present embodiment contains a thermosetting compound (B) (excluding those corresponding to the thermosetting compound (A)) that can undergo a polymerization reaction with the thermosetting compound (A). The type of the thermosetting compound (B) is not particularly limited, but it preferably contains at least one selected from the group consisting of epoxy compounds, cyanate ester compounds, compounds (b) having a terminal carbon-carbon unsaturated double bond, maleimide compounds, nadimide compounds, phenolic compounds, oxetane resins, benzoxazine compounds, arylcyclobutene compounds, perfluorovinyl ether resins, polyimide compounds, and compounds having a vinylene group. It is more preferable that it contains at least one selected from the group consisting of epoxy compounds, cyanate ester compounds, compounds (b) having a terminal carbon-carbon unsaturated double bond, maleimide compounds, and nadimide compounds. It is even more preferable that it contains compounds (b) having a terminal carbon-carbon unsaturated double bond and a maleimide compound. It is even more preferable that it contains a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, a polymer having a structural unit represented by formula (V), and a maleimide compound. Furthermore, the resin composition of this embodiment preferably contains at least a maleimide compound. (In formula (V), Ar represents an aromatic hydrocarbon linking group. * represents a bonding position.)

[0033] The content of the thermosetting compound (B) in the resin composition of this embodiment is preferably 1 part by mass or more, more preferably 10 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, even more preferably 55 parts by mass or more, and preferably 95 parts by mass or less, more preferably 90 parts by mass or less, even more preferably 85 parts by mass or less, even more preferably 80 parts by mass or less, per 100 parts by mass of the resin solid content. By setting the content of the thermosetting compound (B) to the above lower limit or more, the low dielectric properties (Dk and / or Df) tend to be excellent. Furthermore, by setting the content to the above upper limit or less, the flexibility of the resin sheet in the B-stage state tends to be further improved. The resin composition of this embodiment may contain only one type of thermosetting compound (B), or may contain two or more types. When two or more types of thermosetting compounds (B) are included, it is preferable that the total amount is within the above range.

[0034] <<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 at least one 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.

[0035] 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 the epoxy compound is less than 0.1 parts by mass, preferably less than 0.01 parts by mass, and may even be less than 0.001 parts by mass, per 100 parts by mass of the resin solid content in the resin composition.

[0036] <<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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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 in the above range. Furthermore, the resin composition in this embodiment may be configured to be substantially free of cyanate ester compounds. "Substantially free" means that the content of the cyanate ester compound 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 solid content in the resin composition.

[0043] <<Compound (b) Having a Terminal Carbon-Carbon Unsaturated Double Bond>> The compound (b) having a terminal carbon-carbon unsaturated double bond is, for example, a compound that has a terminal carbon-carbon double bond and contains an aromatic ring, and is a compound that is cured by heat (excluding those that fall under the category of thermosetting compound (A)). Specifically, the compound (b) having a terminal carbon-carbon unsaturated double bond preferably includes one or more compounds selected from the group consisting of polyphenylene ether compounds having a terminal carbon-carbon unsaturated double bond and polymers having a structural unit represented by formula (V), and more preferably includes a polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond.

[0044] When the resin composition of this embodiment contains the compound (b) having a terminal carbon-carbon unsaturated double bond, the content thereof is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, and even more preferably 12 parts by mass or more, relative to 100 parts by mass of the resin solids in the resin composition. Depending on the application, etc., it may be 15 parts by mass or more, 25 parts by mass or more, and preferably 95 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less. Depending on the application, etc., it may be 55 parts by mass or less, 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 25 parts by mass or less, or 20 parts by mass or less. By making the content of the compound (b) having a terminal carbon-carbon unsaturated double bond at or above the above lower limit, compatibility and heat resistance tend to be further improved. Furthermore, by setting the content of the compound (b) having a terminal carbon-carbon unsaturated double bond to the above upper limit or less, low thermal expansion properties tend to be further improved. The resin composition of this embodiment may contain only one type of compound (b) 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 is in the above range.

[0045] <<<<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.

[0046] 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).

[0047] (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.

[0048] 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 , R３７ , 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.

[0049] 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 ethylenically unsaturated groups (hereinafter, sometimes referred to as "modified polyphenylene ether compound (g)"), and more preferably a modified polyphenylene ether compound having two or more groups selected from the group consisting of (meth)acryloyl groups and vinylbenzyl groups at 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.

[0050] 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) or formula (Rx-2). (In formula (Rx-1) and 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. * 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.

[0051] 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.

[0052] In formula (Rx-1) and 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.

[0053] 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.

[0054] 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.

[0055] A specific example of the group represented by formula (Rx-1) is a vinylbenzyl group, and a specific example of the group represented by formula (Rx-2) is a (meth)acryloyl group.

[0056] The resin composition of the present embodiment preferably contains, as the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond, a compound represented by formula (OP), which contains both a polyphenylene ether compound having a group represented by formula (Rx-1) and a polyphenylene ether compound having a group represented by formula (Rx-2).

[0057] 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, n ２represents an integer from 1 to 100, and n ３ represents 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.

[0058] 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 １０ , and R １１ may be the same or different and are alkyl groups or phenyl groups having 6 or less carbon atoms. ７ , R ８ , 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 , R １５ , 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.

[0059] In addition, -(Y-O)- is 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.

[0060] 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.

[0061] 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.

[0062] Among the compounds represented by the above formula (OP-2), R ４ , R ５ , R ６ , R １０ , R １１ , R ２０ , and R ２１ is an alkyl group having 3 or less carbon atoms, and R ７ , R ８ , R ９ , R １２ , R １３ , R １４ , R １５ , R １６ , R １７ , R １８ , R １９ , 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.

[0063] (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).

[0064] The modified polyphenylene ether compound (g) is more preferably a compound represented by formula (OP-14) and / or a compound represented by formula (OP-15), and even more preferably a compound represented by formula (OP-15). (In formula (OP-14), a and b each independently represent 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-14) each independently have the same meanings as a and b in formula (OP-2), and the preferred ranges are also the same. (In formula (OP-15), a and b each independently represent 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.

[0065] In addition, the polyphenylene ether compound used in this embodiment may also be a compound represented by formula (OP-16). (In formula (OP-16), a and b each independently represent an integer of 0 to 100, and at least one of a and b is an integer of 1 to 100.)

[0066] 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 products include "SA9000" manufactured by SABIC Innovative Plastics, which is a modified polyphenylene ether compound having a terminal methacryloyl group. Examples of modified polyphenylene ether compounds having a terminal vinylbenzyl group include "OPE-2St1200" and "OPE-2St2200" manufactured by Mitsubishi Gas Chemical Company, Inc. Examples of modified polyphenylene ether compounds having a terminal vinylbenzyl group include polyphenylene ether compounds having a terminal hydroxyl group, such as "SA90" manufactured by SABIC Innovative Plastics, which are modified to a vinylbenzyl group using vinylbenzyl chloride or the like.

[0067] 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.

[0068] The polystyrene-equivalent number average molecular weight (GPC) of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond (preferably, a modified polyphenylene ether compound (g)) is preferably 500 or more and 3,000 or less (details follow the method described in the Examples below). 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 polystyrene-equivalent weight average molecular weight (GPC) of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond (preferably, a modified polyphenylene ether compound (g)) is preferably 800 or more and 10,000 or less, more preferably 800 or more and 5,000 or less (details follow the method described in the Examples below). When the weight-average molecular weight is equal to or greater than the lower limit, the dielectric constant (Dk) and dielectric dissipation factor (Df) of the 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 solvents when preparing varnishes, etc., as described below, tend to be further improved. Furthermore, the terminal carbon-carbon unsaturated double bond equivalent of the polyphenylene ether compound (preferably, the modified polyphenylene ether compound (g)) having a terminal carbon-carbon unsaturated double bond is preferably 400 to 5,000 g, more preferably 400 to 2,500 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 dissipation factor (Df) of the 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 solvents tend to be further improved.

[0069] The functional group equivalent (equivalent of carbon-carbon unsaturated double bond) in 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 IR spectrum of 905 cm is －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.

[0070] 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 thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 8 parts by mass or more, per 100 parts by mass of the resin solids in the resin composition, and may be 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more, depending on the application, etc. By setting the content of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond to be equal to or greater than the above-mentioned lower limit, the moldability of the resin composition and the heat resistance, low water absorbency, and low dielectric properties (Dk and / or Df) of the obtained 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, even more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the resin solids in the resin composition. Depending on the application, it may be 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 25 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, or 12 parts by mass or less. By setting the content of the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond to the above upper limit or less, the low dielectric properties (particularly low dielectric dissipation factor) 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 is within the above range.

[0071] <<<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.

[0072] 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.

[0073] 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)."

[0074] 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 substituents include the aforementioned substituent Z, but it is preferable that the aforementioned groups, such as the phenylene group, be unsubstituted. * indicates a bonding position. The compound that forms 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.

[0075] 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.

[0076] 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).

[0077] The structural unit (b) derived from a monovinyl aromatic compound is preferably a structural unit represented by the following formula (V4).

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] 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) and (c). Further, an example is an embodiment in which the total of the structural units (a) to (c) accounts for 90 mol% or more, even 95 mol% or more, and particularly 98 mol% or more of all structural units. Another example 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, an example is an embodiment in which the total of the structural units (a) to (d) accounts for 95 mol% or more, even 98 mol% or more of all structural units. Another example of a polymer having a structural unit represented by formula (V) is a polymer that essentially contains the structural unit (a), and of all structural units excluding the terminals, preferably 90 mol% or more, more preferably 95 mol% or more, and even 100 mol%. In calculating the mole percentage 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 producing a polymer having a structural unit represented by formula (V).

[0085] 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.

[0086] 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)

[0087] 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)

[0088] 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 be equal to or greater than the lower limit, the excellent low dielectric properties (Dk and / or Df), particularly Df and dielectric properties after moisture absorption, possessed by the polymer having the structural unit represented by formula (V) can be effectively exhibited in the cured product of the resin composition. The upper limit of the weight-average molecular weight Mw is preferably 130,000 or less, more preferably 100,000 or less, even more preferably 80,000 or less, and even more preferably 50,000 or less. By 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.

[0089] 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.

[0090] The cured product of a polymer having a structural unit represented by formula (V) preferably has excellent low dielectric properties (Dk and / or Df). For example, the cured product of the polymer having a 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 a 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 the 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.

[0091] 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. The polymer having the structural unit represented by formula (V) may be a commercially available product, such as LF-310T50 manufactured by Nippon Steel Chemical & Material Co., Ltd.

[0092] 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 3 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. Depending on the application, it may be 10 parts by mass or more, 15 parts by mass or more, 20 parts by mass or more, or 25 parts by mass or more. By setting the content of the polymer having a structural unit represented by formula (V) to the above lower limit 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, even more preferably 70 parts by mass or less, even more preferably 60 parts by mass or less, and may be 50 parts by mass or less, 45 parts by mass or less, 40 parts by mass or less, 35 parts by mass or less, 30 parts by mass or less, 20 parts by mass or less, 15 parts by mass or less, 10 parts by mass or less, or 7 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 the structural unit represented by formula (V) to the above upper limit or less, the metal foil peel strength and low water absorption tend to be improved. The resin composition in this embodiment may contain only one type of polymer having the 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 in the above range.

[0093] <<<Other Compounds (b) Having a Carbon-Carbon Unsaturated Double Bond at a Terminal>>> In addition to the above, examples of the compound (b) having a carbon-carbon unsaturated double bond at a terminal 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.

[0094] The resin composition of the present embodiment may or may not contain a polyphenylene ether compound having at least one of a group represented by formula (1) and a group represented by formula (2). (In formula (1), p represents an integer of 0 to 10. Z represents an arylene group. R １ ~R ３ each independently represents a hydrogen atom or an alkyl group. (In formula (2), R ４ represents a hydrogen atom or an alkyl group.) For details of the polyphenylene ether compound having at least one of the groups represented by formula (1) and the groups represented by formula (2), please refer to the description of WO 2022 / 049965, the contents of which are incorporated herein by reference. An example of this embodiment is that the polyphenylene ether compound having at least one of the groups represented by formula (1) and the groups represented by formula (2) is substantially free of the polyphenylene ether compound. "Substantially free of the polyphenylene ether compound" means that the amount of the polyphenylene ether compound having at least one of the groups represented by formula (1) and the groups represented by formula (2) is less than 10 parts by mass per 100 parts by mass of the thermosetting compound (A) and the thermosetting compound (B) capable of polymerization, preferably less than 7 parts by mass, more preferably less than 5 parts by mass, even more preferably less than 3 parts by mass, even more preferably less than 1 part by mass, and may be less than 0.1 parts by mass or even 0 parts by mass. By adopting such a configuration, the effects of the present invention tend to be more effectively exhibited.

[0095] <<Maleimide Compound>> The resin composition of this embodiment preferably contains a maleimide compound. In this embodiment, the maleimide compound 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. In this embodiment, the maleimide compound preferably includes one or more selected from the group consisting of a compound represented by formula (M0), a compound represented by formula (M1), a compound represented by formula (M2), a compound represented by formula (M3), a compound represented by formula (M4), a compound represented by formula (M5), a maleimide compound (M6), a maleimide compound (M7), and a maleimide compound (M8), and more preferably includes one or more selected from the group consisting of a compound represented by formula (M0), a compound represented by formula (M1), a compound represented by formula (M2), a compound represented by formula (M3), a compound represented by formula (M4), a compound represented by formula (M5), a maleimide compound (M7), and a maleimide compound (M8), and The compound represented by the formula (M2), the compound represented by the formula (M3), the compound represented by the formula (M4), the compound represented by the formula (M5), the maleimide compound (M7), and the maleimide compound (M8) are more preferably contained, and the compound represented by the formula (M1), the compound represented by the formula (M2), the compound represented by the formula (M3), the maleimide compound (M7), and the maleimide compound (M8) are even more preferably contained, and the compound represented by the formula (M1) and / or the maleimide compound (M7) are even more preferably contained. When these maleimide compounds are used in materials for printed wiring boards (e.g., metal foil-clad laminates), excellent heat resistance can be imparted.

[0096] In one example of this embodiment, when the resin composition of this embodiment contains a modified polyphenylene ether compound terminally modified with a substituent having a carbon-carbon unsaturated double bond, it does not contain the maleimide compound represented by formula (M3). "Substantially free" means that the amount of the maleimide compound represented by formula (M3) is less than 10 parts by mass, preferably less than 7 parts by mass, more preferably less than 5 parts by mass, even more preferably less than 3 parts by mass, and even more preferably less than 1 part by mass, and may even be less than 0.1 parts by mass, or even 0 parts by mass. By using such a configuration, the effects of the present invention tend to be more effectively exhibited.

[0097] (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.) R ５１ are each independently preferably one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and a phenyl group, more preferably a hydrogen atom and / or a methyl group, and even more preferably a hydrogen atom. ５２ 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, still more preferably 1 or 2, and even more preferably 1. Specifically, the following compounds are preferred examples of formula (M0). In the above formula, R ８ each independently represents a hydrogen atom, a methyl group, or an ethyl group, and is preferably a methyl group.

[0098] The compound represented by formula (M0) may be a single compound or a mixture of two or more compounds. Examples of the mixture include compounds 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 (M8) below.

[0099] (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.

[0100] 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, more preferably a methyl 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, and 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 A is preferably a 4- to 6-membered alicyclic group, more preferably a 5-membered alicyclic group (preferably a group that forms an indane ring when combined with a benzene ring). 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, more preferably a methyl 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.

[0101] 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.

[0102] 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, more preferably a methyl 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, more preferably a methyl 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.

[0103] 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.

[0104] 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.

[0105] 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.) nx may be an integer of 10 or less.

[0106] 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 (Dk and / or Df) 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.

[0107] For other details of the compound represented by formula (M1), please refer to the descriptions in International Publication No. 2020-217679, the contents of which are incorporated herein by reference.

[0108] (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.

[0109] (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 ５５are each independently preferably one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and a phenyl group, more preferably a hydrogen atom and / or a methyl group, and even more preferably a hydrogen atom. ５ 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. In the compound represented by formula (M3), n ５ 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.

[0110] (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. An example of the compound represented by formula (M4) is ５６ are each independently a methyl group or an ethyl group, and R ５７ is a methyl group. ５６ More preferably, R is a methyl group and R is an ethyl group on each of the two benzene rings. ５６ and R ５７ is a hydrogen atom.

[0111] (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.) R ５８are each independently preferably one selected from the group consisting of a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group, and a phenyl group, more preferably a hydrogen atom and / or a methyl group, and even more preferably a hydrogen atom. 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.

[0112] The maleimide compound (M6) is a compound having a structure represented by formula (M6) and maleimide groups at both ends of the molecular chain. (In formula (M6), R ６１ represents a linear or branched alkylene group having 1 to 16 carbon atoms, or a linear or branched alkenylene group having 2 to 16 carbon atoms. ６２ 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.

[0113] The maleimide compound (M7) is a maleimide compound obtained by reacting raw materials (1) with an aromatic amine compound (a1) having from 1 to 3 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 having a structure 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, 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. * represents a bonding position.)

[0114] 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.

[0115] The maleimide compound (M8) is a bismaleimide compound having a hydrocarbon group in which eight or more atoms are linearly linked, and is preferably a compound represented by formula (M8): Such maleimide compounds (M8) tend to have higher stress relaxation ability, and as a result, the thermal expansion coefficient of the resulting cured product tends to be lower, and the electrical properties such as the dielectric constant and dielectric loss tangent tend to be more excellent. (In formula (M8), R １ and R ３ each independently represents a hydrocarbon group having 8 or more atoms linked in a linear chain, R ２ each independently represents a substituted or unsubstituted cyclic hydrocarbon group having 4 to 10 atoms constituting the ring, which may contain a heteroatom, and n represents a number from 0 to 10.

[0116] In formula (M8), R １ and R ３ is an octylene group, and R ２ is preferably a cycloalkylene group having an alkyl group having 6 to 8 carbon atoms as a substituent.

[0117] For the maleimide compound (M8), the descriptions in paragraphs 0014 to 0022 of JP-A-2018-083893 and paragraphs 0012 to 0022 of JP-A-2018-090728 can be referred to, the contents of which are incorporated herein by reference.

[0118] In addition, the maleimide compounds (maleimide compound (M9)) described in JP-A Nos. 2024-004392 and 2024-161436 can also be used, the contents of which are incorporated herein by reference.

[0119] The maleimide compound 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), and "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd. as the compound represented by formula (M4). Examples of compounds that can be used include "BMI-70" manufactured by K.I. Chemical Industry Co., Ltd. and "BMI-5100" manufactured by Daiwa Kasei Kogyo Co., Ltd.; examples of the compound represented by formula (M5) include "MIR-5000" manufactured by Nippon Kayaku Co., Ltd.; examples of the maleimide compound (M6) include "MIZ-001" manufactured by Nippon Kayaku Co., Ltd.; examples of the maleimide compound (M7) include "NE-X-9500" manufactured by DIC Corporation; examples of the maleimide compound (M8) include "SFR" manufactured by Resonac Inc., and "BMI-689," "BMI-3000," and "BMI-5000" manufactured by Designer Molecules Inc.; and examples of the maleimide compound (M9) include "NE-X-9600" manufactured by DIC Corporation.

[0120] Examples of maleimide compounds other than those described above include N-phenylmaleimide, N-cyclohexylmaleimide, phenylmethane maleimide oligomers, 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, and prepolymers thereof, and prepolymers of these maleimides and amines. In addition to the above, the compounds described in paragraphs 0051 to 0068 of WO 2020 / 262577 can be referenced, the contents of which are incorporated herein by reference. The resin composition of the present embodiment preferably does not contain the following compounds. By adopting such a configuration, the effects of the present invention tend to be more effectively exhibited. In the above formula, R１ is an alkylene group having 6 to 12 carbon atoms.

[0121] The maleimide group equivalent of the maleimide compound is preferably 130 g / eq. or more, more preferably 150 g / eq. or more, even more preferably 170 g / eq. or more, even more preferably 180 g / eq. or more, even more preferably 200 g / eq. or more, even more preferably 290 g / eq. or more, and 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 better. 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 better.

[0122] When the resin composition of this embodiment contains a maleimide compound, the lower limit of the content thereof is preferably 1 part by mass or more, more preferably 5 parts by mass or more, even more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition. Depending on the application, etc., it may be 25 parts by mass or more, 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, or 45 parts by mass or more. When the content of the maleimide compound 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 is preferably 90 parts by mass or less, more preferably 80 parts by mass or less, even more preferably 70 parts by mass or less, and even more preferably 65 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. Depending on the application, etc., it may even be 60 parts by mass or less, 55 parts by mass or less, 50 parts by mass or less, or 45 parts by mass or less. When the content of the maleimide compound is 90 parts by mass or less, the peel strength and low water absorbency tend to be improved. The resin composition of the present embodiment may contain only one maleimide compound or may contain two or more maleimide compounds. When two or more maleimide compounds are contained, the total amount is preferably in the above range.

[0123] <<<Nadiimide Compound>>> The nadiimide compound is not particularly limited as long as it is a compound having a nadiimide group, but a (meth)allyl group-substituted nadiimide compound is preferred, and a compound represented by formula (AN-1) is more preferred. (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 represents 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.

[0124] 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)

[0125] The molecular weight of the nadimide compound (preferably a compound represented by formula (AN-1)) is preferably 400 or more, more preferably 500 or more, and may be 550 or more. By setting the molecular weight of the nadimide compound to the above-mentioned lower limit or more, low dielectric properties, low thermal expansion, and heat resistance tend to be further improved. The molecular weight of the nadimide compound (preferably a compound represented by formula (AN-1)) is also preferably 1500 or less, more preferably 1000 or less, and even more preferably 800 or less, and may be 700 or less, or 600 or less. By setting the molecular weight of the nadimide compound to the above-mentioned upper limit or less, moldability and peel strength tend to be further improved.

[0126] When the resin composition of the present embodiment contains a nadimide compound (preferably a compound represented by formula (AN-1)), 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, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the 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 nadimide compound (preferably a compound represented by formula (AN-1)) 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, relative to 100 parts by mass of the resin solid content in the resin composition. By setting the content of the 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 type of nadimide 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. The resin composition of the present embodiment may be configured to be substantially free of a nadimide compound. "Substantially free" means that the content of the nadimide compound 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 solid content in the resin composition.

[0127] <Blend Form> Next, the blend form of the thermosetting compound (A) and the thermosetting compound (B) in the resin composition of this embodiment will be described. In the resin composition of this embodiment, the blend ratio of the thermosetting compound (A) and the thermosetting compound (B) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and even more preferably 10 parts by mass or more, relative to 100 parts by mass of the total of the thermosetting compound (A) and the thermosetting compound (B). It is also preferably 40 parts by mass or less, more preferably 35 parts by mass or less, and even more preferably 30 parts by mass or less, and may be 20 parts by mass or less. By setting the blend ratio to be equal to or greater than the lower limit, the viscosity of the resin composition is suppressed, and the laminate moldability tends to be better. Furthermore, by setting the blend ratio to be equal to or less than the upper limit, the viscosity of the resin composition is suppressed, and the flow properties of the resin composition when processed into a resin sheet tend to be further improved.

[0128] The total mass of the thermosetting compound (A) and the thermosetting compound (B) in the resin composition of this embodiment is preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and even more preferably 65 parts by mass or more, relative to 100 parts by mass of the resin solid content. Depending on the application, etc., it may be 70 parts by mass or more or 80 parts by mass or more, and is preferably 90 parts by mass or less, and more preferably 85 parts by mass or less.

[0129] In the resin composition of this embodiment, it is preferable that the thermosetting compound (A) contains a compound having a terminal carbon-carbon unsaturated double bond (preferably a (meth)acrylate compound), and the thermosetting compound (B) contains a maleimide compound. In particular, it is preferable that the thermosetting compound (A) contains a compound having a terminal carbon-carbon unsaturated double bond, the thermosetting compound (B) contains a maleimide compound, and the content of the compound having a terminal carbon-carbon unsaturated double bond is 5 to 50 parts by mass per 100 parts by mass of the total of the compound having a terminal carbon-carbon unsaturated double bond and the maleimide compound. By setting the content of the compound having a terminal carbon-carbon unsaturated double bond to be equal to or greater than the above-mentioned lower limit, the flexibility of the resin sheet in the B-stage tends to be further improved. Furthermore, by setting the content to be equal to or less than the above-mentioned upper limit, the glass transition temperature (high Tg) and low thermal expansion (low CTE) of the resulting cured product tend to be further improved. The content of the compound having a terminal carbon-carbon unsaturated double bond relative to 100 parts by mass of the total of the compound having a terminal carbon-carbon unsaturated double bond and the maleimide compound is more preferably 8 parts by mass or more, even more preferably 10 parts by mass or more, and still more preferably 12 parts by mass or more, and is more preferably 45 parts by mass or less, even more preferably 40 parts by mass or less, even more preferably 35 parts by mass or less, still more preferably 30 parts by mass or less, and may be 25 parts by mass or less.

[0130] <Elastomer> The resin composition of this embodiment may contain an elastomer. By including an elastomer, flexibility in the B-stage state can be further improved. The type of elastomer is not particularly limited, and a wide variety of known elastomers can be used. The elastomer is typically a thermoplastic elastomer. In this embodiment, examples of the elastomer 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. Examples of thermoplastic elastomers 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.

[0131] In this embodiment, it is particularly preferable to include an elastomer having a crosslinkable group. The crosslinkable group refers to a group that can react with the thermosetting compound (A) and the thermosetting compound (B) to form a crosslinked structure during curing. By using such an elastomer having a crosslinkable group, the advantage of improved flexibility achieved by incorporating the elastomer can be utilized in the B-stage state. After curing, the elastomer reacts with the thermosetting compound (A) and the thermosetting compound (B) to cure, effectively suppressing thermal expansion of the resulting cured product. The elastomer having a crosslinkable group preferably includes an elastomer (hereinafter sometimes referred to as elastomer (A)) containing a polymer block (a1) containing a styrene compound unit and a conjugated diene compound unit having a radical-reactive group. The elastomer (A) may further include a polymer block (a2) containing a styrene compound unit optionally having a radical-reactive group, and / or a polymer block (a3) ​​containing a conjugated diene compound unit. Furthermore, the elastomer may include polymer blocks other than the polymer blocks (a1) to (a3) ​​within the scope of this embodiment. By using an elastomer containing a polymer block (a1) containing such a styrene compound unit having a radical reactive group and a conjugated diene compound unit, a resin composition can be obtained that, when cured, maintains low dielectric properties (Dk and / or Df) while exhibiting a low thermal expansion coefficient. More specifically, by containing a styrene compound unit having a radical reactive group as the polymer block (a1) or as the polymer block (a1) and the polymer block (a2), the elastomer (A) forms a crosslinked structure with the thermosetting compound (A) and / or the thermosetting compound (B) when cured, thereby effectively suppressing thermal expansion. Furthermore, by containing a conjugated diene compound unit as the polymer block (a1) or as the polymer block (a1) and the polymer block (a3), the elastomer (A) exhibits excellent low dielectric properties (Dk and / or Df) when cured.

[0132] The elastomer (A) contains a polymer block (a1) (sometimes simply referred to as "polymer block (a1)" in this specification) containing a styrene compound unit having a radical reactive group and a conjugated diene compound unit. The polymer block (a1) is preferably a copolymer block containing a styrene compound unit having a radical reactive group and a conjugated diene compound unit.

[0133] A radically reactive group refers to a chemical group that is capable of forming, or can be induced to form, a free radical species. The free radical species can be formed by any known means, including thermal means, photochemical means, or chemical reagents. For example, CHR ２ -CHR in the structure of the benzene ring ２ The portion may be a radical reactive group. Here, each R is independently a hydrogen atom or a monovalent alkyl group having 1 to 3 carbon atoms, preferably a hydrogen atom or a methyl group, and more preferably all R are hydrogen atoms. Another example of a radical reactive group is a cyclobutane ring, which can be activated, for example, by light, to form a free radical species. Another example of a radical reactive group is an allyl group, which can form an allyl free radical. In this embodiment, the radical reactive group preferably includes a methyl group.

[0134] As the styrene compound having a radical reactive group, a compound represented by any one of formulas (I) to (IV) is preferred, and a compound represented by formula (I) is more preferred. (In formula (I), each R independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In formulas (I) to (IV), R １ represents a hydrogen atom or a methyl group.

[0135] In formula (I), each R is preferably independently a hydrogen atom, a methyl group, or an ethyl group, and more preferably all R are hydrogen atoms. ２The substituent represented by the formula (I) to (IV) may be bonded at any of the ortho, meta, and para positions, but is preferably bonded at the ortho or para position, and more preferably at the para position. １ is preferably a hydrogen atom.

[0136] Specifically, the styrene compound unit having a radical reactive group is preferably at least one selected from the group consisting of an o-methylstyrene unit, a p-methylstyrene unit, an o-ethylstyrene unit, a p-ethylstyrene unit, an o-isopropylstyrene unit, a p-isopropylstyrene unit, an o-methyl-α-methylstyrene unit, a p-methyl-α-methylstyrene unit, an o-ethyl-α-methylstyrene unit, a p-ethyl-α-methylstyrene unit, an o-isopropyl-α-methylstyrene unit, and a p-isopropyl-α-methylstyrene unit, and more preferably contains a p-methylstyrene unit.

[0137] The content of the styrene compound units having a radical reactive group in the polymer block (a1) is preferably 10% by mass or more, more preferably 20% by mass or more, based on 100% by mass of the polymer block (a1). Depending on the application, it may be 25% by mass or more, 30% by mass or more, and preferably 80% by mass or less, more preferably 70% by mass or less. Depending on the application, it may be 65% by mass or less, 60% by mass or less. By setting the content of the styrene compound units having a radical reactive group in the polymer block (a1) to the above lower limit or more, the number of crosslinking reaction sites with the thermosetting compound increases, and heat resistance and low thermal expansion properties tend to be further improved. Furthermore, by setting the content of the styrene compound units having a radical reactive group in the polymer block (a1) to the above upper limit or less, low dielectric properties tend to be further improved. The polymer block (a1) may contain only one type of styrene compound unit having a radical reactive group, or two or more types. When two or more types are contained, the total amount is preferably within the above range.

[0138] The polymer block (a1) contains a conjugated diene compound unit. The conjugated diene compound unit preferably contains at least one selected from the group consisting of a butadiene unit, an isoprene unit, a 2,3-dimethyl-1,3-butadiene unit, a 1-phenyl-1,3-butadiene unit, a 1,3-pentadiene unit, a 1,3-hexadiene unit, a 3-butyl-1,3-octadiene unit, a farnesene unit, a myrcene unit, a piperylene unit, and a cyclohexadiene unit, more preferably contains a butadiene unit and / or an isoprene unit, and even more preferably contains at least a butadiene unit. In this specification, unless otherwise specified, the conjugated diene compound unit may be hydrogenated, partially hydrogenated, or non-hydrogenated, and is more preferably hydrogenated and / or partially hydrogenated. When the conjugated diene compound unit contains a hydrogenated product and / or a partially hydrogenated product, the compatibility of the compound represented by formula (M1) is further improved, and a cured product with a lower dielectric constant can be obtained.

[0139] In this embodiment, the conjugated diene compound units more preferably contain hydrogenated or partially hydrogenated butadiene units and / or hydrogenated or partially hydrogenated isoprene units. The conjugated diene units are preferably 1,3-butadiene units, and more preferably hydrogenated or partially hydrogenated 1,3-butadiene units. Typically, hydrogenated butadiene units contain butylene units and / or ethylene units. Furthermore, hydrogenated isoprene units contain ethylene units and propylene units. In this embodiment, the conjugated diene compound units preferably contain butylene units and / or ethylene units. By containing butylene units and / or ethylene units, low dielectric properties and flexibility tend to be further improved.

[0140] The content of the conjugated diene compound units in the polymer block (a1) is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 30% by mass or more, based on 100% by mass of the polymer block (a1). Depending on the intended use, the content may be 35% by mass or more, 40% by mass or more, and preferably 90% by mass or less, more preferably 85% by mass or less, and even more preferably 80% by mass or less. Depending on the intended use, the content may be 75% by mass or less, 70% by mass or less. By setting the content of the conjugated diene compound units to the above-mentioned lower limit or more, compatibility with thermosetting compounds (particularly compounds having a terminal carbon-carbon unsaturated double bond) tends to be further improved. Furthermore, by setting the content of the conjugated diene compound units to the above-mentioned upper limit or less, low dielectric properties tend to be further improved. The polymer block (a1) may contain only one type of conjugated diene compound unit, or may contain two or more types. When two or more types are contained, the total amount preferably falls within the above-mentioned range. The total amount of the styrene compound units having a radical reactive group and the conjugated diene units contained in the polymer block (a1) does not exceed 100% by mass.

[0141] The polymer block (a1) may or may not contain a monomer unit (other monomer unit) other than the styrene compound unit having a radical reactive group and the conjugated diene compound unit. Examples of the other monomer unit that may be contained in the polymer block (a1) include at least one selected from the group consisting of a styrene unit, a substituted styrene unit (excluding a styrene compound unit having a radical reactive group), a vinylnaphthalene unit, a substituted vinylnaphthalene unit, a vinylindene unit, a vinylanthracene unit, a 1,1-diphenylethylene unit, a vinylnaphthalene unit, a vinyltoluene unit, and a vinylxylene unit.

[0142] In the polymer block (a1), the total amount of the styrene compound units and conjugated diene compound units having a radical reactive group is preferably 85% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on 100% by mass of the polymer block (a1). It may be 99% by mass or more, or even 100% by mass.

[0143] The elastomer (A) used in this embodiment may contain a polymer block other than the polymer block (a1) described above. Specifically, the elastomer (A) preferably further contains a polymer block (a2) (sometimes simply referred to as "polymer block (a2)" herein) containing a styrene compound unit optionally having a radical reactive group, and / or a polymer block (a3) ​​(sometimes simply referred to as "polymer block (a3)" herein) containing a conjugated diene compound unit.

[0144] When the styrene compound unit which may have a radical reactive group in the polymer block (a2) contains a styrene compound unit having a radical reactive group, the styrene compound unit having a radical reactive group has the same meaning as that described for the polymer block (a1) above, and preferred embodiments are also the same. Examples of the styrene compound unit other than the styrene compound unit having a radical reactive group include a styrene unit and a substituted styrene unit (excluding a styrene compound unit having a radical reactive group).

[0145] The content of the styrene compound unit optionally having a radical reactive group in the polymer block (a2) is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, even more preferably 99% by mass or more, and may be 100% by mass, based on 100% by mass of the polymer block (a2). The content of the styrene compound unit optionally having a radical reactive group in the polymer block (a2) is preferably 30% by mass or more, more preferably 50% by mass or more, still more preferably 80% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and may be 99% by mass or more, or may be 100% by mass, based on 100% by mass of the polymer block (a2).

[0146] The conjugated diene compound units in the polymer block (a3) ​​have the same meanings and preferred embodiments as those described for the polymer block (a1). The content of the conjugated diene compound units in the polymer block (a3) ​​is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 99% by mass or more, based on 100% by mass of the polymer block (a3), and may be 100% by mass.

[0147] In this embodiment, the polymer block (a2) and the polymer block (a3) ​​may each independently contain, or may not contain, other monomer units other than the styrene compound unit and the conjugated diene compound unit, which may have a radical reactive group. Examples of other monomer units that may be contained in the polymer block (a2) and the polymer block (a3) ​​include, independently, at least one selected from the group consisting of a vinylnaphthalene unit, a substituted vinylnaphthalene unit, a vinylindene unit, a vinylanthracene unit, a 1,1-diphenylethylene unit, a vinylnaphthalene unit, a vinyltoluene unit, and a vinylxylene unit.

[0148] In the elastomer (A) of this embodiment, the above-mentioned polymer blocks are preferably bonded by coupling.

[0149] In this embodiment, the content of the styrene compound units having a radical reactive group in the elastomer (A) (the total amount of the styrene compound units having a radical reactive group contained in the polymer block (a1), polymer block (a2), etc.) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, even more preferably 25% by mass or more, even more preferably 30% by mass or more, even more preferably 40% by mass or more, and is preferably 80% by mass or less, more preferably 70% by mass or less, even more preferably 60% by mass or less, even more preferably 55% by mass or less, and even more preferably 50% by mass or less. By setting the content of the styrene compound units having a radical reactive group in the elastomer (A) to be equal to or greater than the above-mentioned lower limit, the number of crosslinking reaction sites with the thermosetting compound increases, and heat resistance and low thermal expansion properties tend to be further improved. Furthermore, by setting the content of the styrene compound units having a radical reactive group in the elastomer (A) to be equal to or less than the above-mentioned upper limit, low dielectric properties tend to be further improved.

[0150] The content of conjugated diene units in the elastomer (A) (total amount of conjugated diene units in the polymer blocks (a1), (a3), etc.) is preferably 20% by mass or more, more preferably 30% by mass or more, even more preferably 35% by mass or more, even more preferably 40% by mass or more, even more preferably 45% by mass or more, and even more preferably 50% by mass or more. It is also preferably 90% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, even more preferably 75% by mass or less, even more preferably 70% by mass or less, and even more preferably 60% by mass or less. By setting the content of conjugated diene units in the elastomer (A) to the above lower limit or more, compatibility with thermosetting compounds tends to be further improved. By setting the content of conjugated diene units in the elastomer (A) to the above upper limit or less, low dielectric properties tend to be further improved. The total amount of the styrene compound units having a radical reactive group and the conjugated diene units contained in the elastomer (A) does not exceed 100% by mass.

[0151] In this embodiment, the elastomer (A) has at least one polymer block (a1) and may also contain a polymer block (a2) and / or a polymer block (a3). The elastomer (A) preferably contains the polymer block (a1) and the polymer block (a2), and more preferably contains all of the polymer block (a1), the polymer block (a2), and the polymer block (a3). Specific examples of structures containing at least one polymer block (a1) and polymer block (a2) include at least one selected from the group consisting of (a2)-(a1), (a2)-(a1)-(a2), ((a2)-(a1))nX, (a2)-(a1)-(a2)-(a1), ((a1)-(a2)-(a1))nX, ((a1)-(a2))nX, and ((a2)-(a1)-(a2))nX, and more preferably ((a2)-(a1))nx. Here, X represents a coupling agent residue, and n is 1 to 30. The coupling agent may be selected from methyltrimethoxysilane, tetramethoxysilane, divinylbenzene, dimethyl adipate, and mixtures thereof.

[0152] The elastomer (A) preferably has a maximum Tan δ peak temperature of -30 to 80°C, more preferably 0 to 80°C, as measured by dynamic mechanical analysis (DMA) at a frequency of 10 rad / s. This range tends to improve the heat resistance of the resulting cured product. The Tan δ peak temperature is measured by dynamic mechanical analysis (DMA) in accordance with ASTM 4065, using a parallel plate configuration, an angular frequency of 10 rad / s, and a temperature sweep of +2°C per minute. The Tan δ peak temperature of a rubber is the temperature at which the Tan δ peak, corresponding to the glass-to-rubber transition, reaches its maximum value. The final crossover temperature (Tcrossover) is the temperature corresponding to the transition from more elastic behavior observed in the rubbery plateau zone to more viscous behavior observed at higher temperatures. Tcrossover is the temperature at which the elastic and viscous moduli are equal, i.e., Tan δ is 1.

[0153] The elastomer (A) of this embodiment can be produced by the method described in paragraphs 0038 to 0045 and 0104 to 0107 of JP 2022-33057 A. As such a commercially available product, for example, MD3501 manufactured by Kraton Corporation can be used.

[0154] In this embodiment, the "molecular weight" of the elastomer (A) refers to the styrene equivalent molecular weight of each polymer block in kg / mol. The molecular weight can be measured, for example, by gel permeation chromatography (GPC) using polystyrene calibration standards according to ASTM 5296. The chromatograph is calibrated using commercially available polystyrene molecular weight standards. The molecular weight of a polymer measured using GPC calibrated in this manner is the styrene equivalent molecular weight. The detector may be a combination of an ultraviolet detector and a refractive index detector. The molecular weight expressed herein is measured at the peak of the GPC trace and is generally referred to as the "peak molecular weight." The content of styrene compound units and conjugated diene compound units having radical reactive groups is calculated based on the peak molecular weight.

[0155] In this embodiment, the peak molecular weight (Mp) of the polymer block (a1) is preferably 20 kg / mol or more, more preferably 30 kg / mol or more, even more preferably 40 kg / mol or more, still more preferably 50 kg / mol or more, and is preferably 60 kg / mol or more and 200 kg / mol or less, more preferably 180 kg / mol or less, even more preferably 160 kg / mol or less, still more preferably 140 kg / mol or less, and still more preferably 120 kg / mol or less.

[0156] In the present embodiment, the peak molecular weight (Mp) of the polymer block (a2) is preferably 3 kg / mol or more, more preferably 5 kg / mol or more, and even more preferably 10 kg / mol or more. Depending on the application, etc., it may be 15 kg / mol or more or 20 kg / mol or more. Also, it is preferably 60 kg / mol or less, more preferably 50 kg / mol or less, even more preferably 45 kg / mol or less, even more preferably 40 kg / mol or less, and even more preferably 35 kg / mol or less. Depending on the application, etc., it may be 30 kg / mol or less or 20 kg / mol or less.

[0157] In this embodiment, when the elastomer (A) is hydrogenated, the RU of the hydrogenated elastomer is preferably 0 to 1.5 meq / g, more preferably 0.01 to 1.4 meq / g, and even more preferably 0.02 to 1.3 meq / g, and may be 0.05 to 1.2 meq / g, 0.1 to 1.1 meq / g, or 0.2 to 1.0 meq / g. RU refers to the amount of olefin C═C groups in the polymerized diene units in the elastomer (A) that have not been reduced after hydrogenation, expressed in milliequivalents per gram (meq / g). RU is １ It is determined from the H-NMR spectrum.

[0158] The ratio of aromatic groups having two adjacent aromatic units in a polymer block (aromatic block index) is, for example, １ It can be calculated based on the H-NMR spectrum. Specifically, it is given by the formula: aromatic blockiness index = 100 × integral 2 / integral 1, where integral 1 is the integral between 7.5 ppm and 6.0 ppm. １ It is determined by integrating the H-NMR spectrum and dividing the obtained value by "N", where "N" is the average number of protons directly bonded to the aromatic ring, for example, 5 for an unsubstituted aromatic group (phenyl ring), 4 for a monosubstituted aromatic group such as a paramethylstyryl group, and 3 for a disubstituted aromatic group such as a dimethylstyryl group. The integral 2 is １It is determined by integrating the H-NMR spectrum from the signal minimum of 6.9-6.6 ppm to 6.0 ppm and dividing by 2. In practice, integral 2 is determined by integrating the area of ​​the spectrum from the signal minimum covering the region of the steepest valley between the downfield chemical shift of 6.9-6.6 ppm and the upfield chemical shift of 6.0 ppm. When calculating the peak areas of integral 1 and integral 2, the peak areas resulting from solvent protons are not included.

[0159] In addition to the above, the elastomer (A) can be found in JP 2022-33057 A (specifically, paragraphs 0004 to 0045, paragraphs 0065 to 0073, etc.), the contents of which are included in this specification.

[0160] The content of the elastomer (preferably, elastomer (A)) in the resin composition of this embodiment is preferably 0.5 to 30 parts by mass per 100 parts by mass of the resin solid content in the resin composition. The content of the elastomer (preferably, elastomer (A)) is preferably 2 parts by mass or more, more preferably 4 parts by mass or more, and may even be 5 parts by mass or more, 6 parts by mass or more, or 8 parts by mass or more per 100 parts by mass of the resin solid content in the resin composition. It is also preferably 28 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less. Depending on the application, it may be 18 parts by mass or less, or 15 parts by mass or less. By setting the content of the elastomer (preferably, elastomer (A)) to the above lower limit or more, the low dielectric properties and low thermal expansion properties of the resulting cured product tend to be further improved. Furthermore, by setting the content of the elastomer (preferably, elastomer (A)) to the above upper limit or less, the heat resistance of the resulting cured product tends to be further improved. The resin composition of the present embodiment may contain only one type of elastomer, or may contain two or more types. When two or more types are contained, the total amount is preferably in the above range.

[0161] <Flame Retardant> The resin composition of the present embodiment may contain a flame retardant. Examples of the flame retardant include phosphorus-based flame retardants, halogen-based flame retardants, inorganic flame retardants, and silicone-based flame retardants, and phosphorus-based flame retardants are preferred. As the flame retardant, known ones can be used, 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; phosphorus-containing flame retardants such as red phosphorus; tricresyl phosphate, triphenyl phosphate, 2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, cresyl diphenyl phosphate, trixylenyl phosphate, trialkyl phosphate, dialkyl phosphate, tris(chloroethyl) phosphorus-based flame retardants such as monomeric phosphate esters such as phosphazene, phenoxyphosphazene, 1,3-phenylenebis(2,6-dixylenyl phosphate), xylenebisdiphenylphosphine oxide of the bisdiphenylphosphine oxide type, condensed phosphate esters of dixylenyl phosphate, 6H-dibenz[c,e][1,2]oxaphosphorine,6,6'-[1,4-phenylenebis(methylene)]bis-,6,6'-dioxide, and condensed phosphate esters such as phosphinate metal salts of dialkylphosphinic aluminum salts; 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, among these, 1,3-phenylenebis(2,6-dixylenyl phosphate) is preferred because it does not impair the low dielectric properties (Dk and / or Df). Phosphorus-based flame retardants such as the phosphorus-based flame retardant group A shown below are also preferred. <Phosphorus-based flame retardant group A>

[0162] 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, and even more preferably 5 parts by mass or more, per 100 parts by mass of the resin solid content in the resin composition, and is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, even more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less. The flame retardants can be used alone or in combination of two or more. When two or more types are used, the total amount is within the above range.

[0163] <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 organic metal salts (e.g., zinc octylate, zinc naphthenate, cobalt naphthenate, copper naphthenate, iron acetylacetonate, nickel octylate, manganese octylate, etc.), phenolic compounds (e.g., phenol, xylenol, cresol, resorcinol, catechol, octylphenol, nonylphenol, etc.), alcohols (e.g., 1-butanol, 2-ethylhexanol, etc.), imidazoles (e.g., 2-methylimidazole, 2-ethyl-4-methylimidazole (2E4MZ), 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole, Examples of suitable curing accelerators include 1-cyanoethyl-2-ethyl-4-methylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1,2,3-benzotriazole, and derivatives of these imidazoles, such as adducts of carboxylic acids or their acid anhydrides, amines (e.g., dicyandiamide, benzyldimethylamine, 4-methyl-N,N-dimethylbenzylamine, and the like), phosphorus compounds (e.g., phosphine compounds, phosphine oxide compounds, phosphonium salt compounds, diphosphine compounds, and the like), and epoxy-imidazole adduct compounds. Among these, preferred curing accelerators are imidazole curing accelerators (at least one selected from the group consisting of imidazoles, derivatives of imidazoles, such as adducts of carboxylic acids or their acid anhydrides, and epoxy-imidazole adduct compounds) and / or organometallic salts, with imidazoles being more preferred.

[0164] 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, even more preferably 0.05 parts by mass or more, and even more preferably 0.08 parts by mass or more, per 100 parts by mass of the resin solids in the resin composition. The upper limit of the curing accelerator content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 2 parts by mass or less, even more preferably 1.0 parts by mass or less, even more preferably 0.8 parts by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.3 parts by mass or less, and may be 0.2 parts by mass or less, 0.15 parts by mass or less, depending on the application. The resin composition of this embodiment is preferred because the resin composition can be sufficiently cured even when the content of the curing accelerator is below the upper limit. 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.

[0165] <Radical Polymerization Initiator> The resin composition of this embodiment preferably contains a radical polymerization initiator. The type of radical polymerization initiator is not particularly limited, and examples include thermal radical polymerization initiators and photoradical polymerization initiators, with thermal radical polymerization initiators being preferred. Specific examples of radical polymerization initiators include peroxides, azo compounds, benzoin compounds, acetophenone compounds, anthraquinone compounds, thioxanthone compounds, ketal compounds, benzophenone compounds, and phosphine oxide compounds, with peroxides being preferred. Examples of peroxides include compounds having a peroxy group (—O—O—) in the molecule, with compounds having a t-butylperoxy group, compounds having a cumylperoxy group, and compounds having a benzoylperoxy group being preferred. Specific examples include benzoyl peroxide (BPO), p-chlorobenzoyl peroxide, dicumyl peroxide (dicup), di-t-butyl peroxide, diisopropyl peroxycarbonate, 2,5-dimethyl-2,5-di-t-butylperoxyhexyne (DYBP), and 2,5-dimethyl-2,5-di-t-butylperoxyhexane. Commercially available products include Perbutyl H, Perbutyl P, Perbutyl PV, Percumyl H, Percumyl P, Percumyl D, Perocta H, and Perhexa 25B, manufactured by NOF Corporation. An azo compound refers to a compound having an azo group (-N=N-) in the molecule, and a specific example is azobisisobutyronitrile (AIBN). Commercially available products include AIBN, V-70, and V-65, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. Although not a peroxide, 2,3-dimethyl-2,3-diphenylbutane can also be used as a radical polymerization initiator. Commercially available products include Nofumer BC-90. Further examples include the radical polymerization initiators described in paragraph 0042 of WO 2013 / 047305, the contents of which are incorporated herein by reference.

[0166] When the resin composition of this embodiment contains a radical polymerization initiator, the content thereof is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and even more preferably 0.08 parts by mass or more, per 100 parts by mass of the resin solid content. The upper limit of the radical polymerization initiator content is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, even more preferably 2 parts by mass or less, even more preferably 1.0 parts by mass or less, even more preferably 0.8 parts by mass or less, even more preferably 0.5 parts by mass or less, and even more preferably 0.3 parts by mass or less, and may be 0.2 parts by mass or less, 0.15 parts by mass or less, depending on the application. The radical polymerization initiators 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.

[0167] The resin composition of this embodiment preferably contains both a radical polymerization initiator and a curing accelerator (preferably an imidazole-based curing accelerator, more preferably an imidazole). As will be described in the section on the second embodiment of the multilayer body below, when a resin sheet in a B-stage state is laminated on a glass core and then cured to a C-stage state, curing at about 180°C (e.g., 160 to 200°C, preferably 170 to 190°C) is desirable. In this case, the curing proceeds more effectively if a radical polymerization initiator is also included in addition to the imidazole-based catalyst. In particular, when the thermosetting compound (A) contains a (meth)acrylate compound and the thermosetting compound (B) contains a maleimide compound, two maleimide groups can be bonded to one (meth)acryloyl group, thereby allowing curing to proceed more effectively.

[0168] <Filler> The resin composition of this embodiment may contain a filler. By including a filler, the dielectric properties (dielectric constant and / or dielectric dissipation factor), flame resistance, low thermal expansion, and other physical properties of the resin composition and its cured product can be further improved. Furthermore, the filler used in this embodiment preferably has excellent low dielectric properties (Dk and / or Df). For example, the filler used in this embodiment preferably has a dielectric constant (Dk) of 8.0 or less, more preferably 6.0 or less, and even more preferably 4.0 or less at a frequency of 10 GHz, as measured according to a cavity resonator perturbation method. Furthermore, a practical lower limit of the dielectric constant is, for example, 2.0 or more. Furthermore, the filler used in this embodiment preferably has a dielectric dissipation factor (Df) of 0.05 or less, more preferably 0.01 or less at a frequency of 10 GHz, as measured according to a cavity resonator perturbation method. Furthermore, a practical lower limit of the dielectric dissipation factor is, for example, 0.0001 or more.

[0169] The filler used in this embodiment is not particularly limited in type, and can suitably be used as the one generally used in this industry.Specifically, silica such as natural silica, fused silica, synthetic silica, amorphous silica, aerosil, hollow silica, alumina, white carbon, titanium white, titanium oxide, zinc oxide, magnesium oxide, zirconium oxide, etc. metal oxide, zinc borate, zinc stannate, forsterite, barium titanate, strontium titanate, calcium titanate, etc. composite oxide, boron nitride, aggregated boron nitride, silicon nitride, aluminum nitride, etc. nitride, aluminum hydroxide, aluminum hydroxide heat treatment product (aluminum hydroxide is heat treated, and part of crystal water is reduced), boehmite, magnesium hydroxide, etc. metal hydroxide (including hydrate), acid Examples of fillers include molybdenum compounds such as molybdenum chloride and zinc molybdate, barium sulfate, clay, kaolin, talc, calcined clay, calcined kaolin, calcined talc, mica, E-glass, A-glass, NE-glass, NER-glass, C-glass, L-glass, D-glass, S-glass, M-glass G20, short glass fibers (including fine glass powders such as E-glass, T-glass, D-glass, S-glass, and Q-glass), hollow glass, and spherical glass, as well as organic fillers such as styrene-type, butadiene-type, and acrylic-type rubber powders, core-shell-type rubber powders, silicone resin powders, silicone rubber powders, and silicone composite powders. In this embodiment, inorganic fillers are preferred, and more preferably contain one or more selected from the group consisting of silica, aluminum hydroxide, talc, aluminum nitride, boron nitride, forsterite, titanium oxide, barium titanate, strontium titanate, and calcium titanate. From the viewpoint of low dielectric properties (Dk and / or Df), more preferably contain one or more selected from the group consisting of silica and aluminum hydroxide, even more preferably contain silica, and even more preferably contain hollow silica. The use of these inorganic fillers further improves the properties of the cured product of the resin composition, such as heat resistance, dielectric properties, thermal expansion properties, dimensional stability, and flame retardancy.

[0170] The content of the filler (preferably an inorganic filler) in the resin composition of this embodiment can be appropriately set depending on the desired properties and is not particularly limited. However, it is preferably 1 part by mass or more, more preferably 5 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, it may be 30 parts by mass or more, 50 parts by mass or more, 100 parts by mass or more, or 120 parts by mass or more. By setting the content at or above the lower limit, the low thermal expansion and low dielectric loss tangent of the obtained cured product tend to be more excellent. Furthermore, the upper limit of the filler content is preferably 180 parts by mass or less, per 100 parts by mass of the resin solid content in the resin composition. Depending on the application, it may be 150 parts by mass or less, or 100 parts by mass or less. Setting the content at or below the upper limit tends to further improve the moldability of the resin composition. The resin composition of this embodiment may contain only one type of filler, 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 resin composition of the present embodiment may also be configured to be substantially free of fillers. "Substantially free" means that the content of fillers is less than 1 part by mass, preferably less than 0.5 parts by mass, and even less than 0.1 parts by mass, per 100 parts by mass of the resin solid content in the resin composition.

[0171] When a filler, particularly an inorganic filler, is used in the resin composition of this embodiment, the resin composition may further contain a silane coupling agent. The inclusion of a silane coupling agent tends to further improve the dispersibility of the filler and the adhesive strength between the resin component and the filler. The silane coupling agent is not particularly limited, and examples thereof include silane coupling agents generally used for 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, vinyltriethoxysilane, tetravinylsilane, triethylvinylsilane, 1,3-vinyltetramethylsiloxane, etc.), styrylsilane compounds (e.g., 4-vinylphenyltrimethoxysilane, etc.), acrylicsilane compounds (e.g., γ-acryloxypropyltrimethoxysilane, etc.), cationic silane compounds (e.g., N-β-(N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride, etc.), and phenylsilane compounds. Among these, it is preferable to include at least one selected from the group consisting of vinylsilane compounds, styrylsilane compounds, and acrylicsilane compounds, with vinylsilane compounds being more preferable. The silane coupling agent 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 5.0 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

[0172] In the resin composition of the present embodiment, the filler (preferably an inorganic filler (more preferably silica)) may be surface-treated with the above-mentioned silane coupling agent, and preferably may be surface-treated with at least one compound selected from the group consisting of vinylsilane compounds, styrylsilane compounds, and acrylicsilane compounds.

[0173] <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.

[0174] 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.

[0175] <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.

[0176] <Other Components> In addition to the above components, the resin composition of this embodiment may contain various polymer compounds such as thermoplastic resins and their oligomers, active ester compounds, petroleum resins, and various additives. Examples of additives include ultraviolet absorbers, antioxidants, photopolymerization initiators (excluding those corresponding to the above-mentioned radical polymerization initiators), fluorescent brighteners, photosensitizers, dyes, pigments, thickeners, flow adjusters, lubricants, antifoaming agents, leveling agents, gloss agents, and polymerization inhibitors. In addition to the above, the components described in paragraphs 0064 to 0066 of WO 2021 / 172317 and paragraphs 0126 to 0148 of WO 2024 / 024664 can also be blended, and the contents of these components are incorporated herein. Furthermore, in the resin composition of this embodiment, the total content of the polyphenylene ether compound other than the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond and the thermoplastic elastomer other than the elastomer having a crosslinkable group is preferably 3% by mass or less, more preferably 1% by mass or less, of the resin solids. By adopting such a configuration, the effects of the present invention can be more effectively exhibited. Furthermore, the total content of the polyphenylene ether compound other than the polyphenylene ether compound having a terminal carbon-carbon unsaturated double bond and the butadiene-based elastomer not containing a styrene skeleton is preferably 3% by mass or less, more preferably 1% by mass or less, of the resin solids. By adopting such a configuration, the effects of the present invention can be more effectively exhibited.

[0177] <Uses of Resin Composition> 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 a resin composition for electronic materials. The resin composition of this embodiment can be suitably used as a material for prepregs, metal foil-clad laminates using prepregs, resin sheets, and printed wiring boards. The printed wiring board referred to here is not particularly limited and includes, for example, rigid substrates, flexible substrates, semiconductor package substrates (substrates for mounting semiconductor elements), and organic interposers. For details of these, please refer to paragraphs 0152 to 0167 of WO 2024 / 024664, as well as the descriptions in JP 2022-99579 A and JP 2022-089837 A, the contents of which are incorporated herein by reference.

[0178] The resin composition of the present embodiment is preferably one that is brought to a B-stage state by being applied to a substrate film and then dried or heated. Examples of the substrate film include the substrate films described in the section <Multilayer body> below.

[0179] <Resin Sheet> The resin sheet of this embodiment is formed from the resin composition of this embodiment. An example of the resin sheet of this embodiment is in a B-stage state. Another example of the resin sheet of this embodiment is in a C-stage state (a state in which curing has progressed more than in the B-stage state, and is fully cured or close to it). One form of the resin sheet of this embodiment is that it does not contain glass cloth (or even a prepreg substrate). The resin composition of this embodiment has excellent flexibility and high toughness even when processed into a resin sheet that does not contain glass cloth. Furthermore, because of its excellent flexibility and high toughness, it is characterized by being less susceptible to breakage or cracking even when the resin sheet is thin. Another form of the resin sheet of this embodiment is a prepreg. In particular, a prepreg in which a substrate is impregnated with the resin composition of this embodiment is exemplified. Examples of the substrate include the substrate (prepreg substrate) described in the section <Prepreg> below, with glass cloth (woven glass fabric) being preferred.

[0180] The thickness of the resin sheet of this embodiment is preferably 20 μm or more, more preferably 25 μm or more, and is preferably 50 μm or less, more preferably 40 μm or less. By setting the thickness at or above the lower limit, the thickness tolerance of the resin sheet during production tends to be reduced. Furthermore, by setting the thickness at or below the upper limit, the amount of residual solvent in the resin composition tends to be reduced.

[0181] To bring the resin sheet of this embodiment into a B-stage state, it is preferable to apply the resin composition of this embodiment to a substrate film and dry or heat it. The drying (heating) temperature is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 115°C or higher, and even more preferably 120°C or higher, and preferably 200°C or lower, more preferably 190°C or lower, and even more preferably 180°C or lower. The drying (heating) time is preferably 3 minutes or longer, more preferably 4 minutes or longer, and even more preferably 5 minutes or longer, and preferably 12 minutes or shorter, more preferably 10 minutes or shorter, and even more preferably 8 minutes or shorter. Since the thermal decomposition temperature of the thermosetting compound (A) is high, the resin composition of this embodiment usually reaches a B-stage state at the above drying (heating) temperature. Furthermore, at the above drying (heating) temperature, the resin composition usually does not completely cure, and the B-stage state is maintained.

[0182] <Multilayer Body> Next, the multilayer body of this embodiment will be described. A first embodiment of the multilayer body of this embodiment has a base film and a resin sheet. Preferably, it has a base film, a resin sheet, and a cover film. In one example of the first embodiment of the multilayer body of this embodiment, the base film and the resin sheet are laminated in the aforementioned order, and the resin sheet is a layer in a B-stage state formed from the resin composition of this embodiment. In another example of the first embodiment of the multilayer body of this embodiment, the base film, the resin sheet, and the cover film are laminated in the aforementioned order, and the resin sheet is a layer in a B-stage state formed from the resin composition of this embodiment. FIG. 1 is a cross-sectional schematic diagram showing an example of the first embodiment of the multilayer body. In the multilayer body 1, a base film 2, a resin sheet 3, and a cover film 4 are laminated in the aforementioned order. The multilayer body 1 of the first embodiment may or may not have another layer between the base film 2 and the resin sheet 3 and / or between the resin sheet 3 and the cover film 4. An example of the other layer is a release treatment layer. An example of the release treatment layer is TRF (manufactured by Unitika Ltd.).

[0183] The substrate film 2 is typically a film to which a resin composition is applied, and examples thereof 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 Steel) plates, FRP (Fiber-Reinforced Plastics), etc. Among these, one selected from the group consisting of polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, and ethylene tetrafluoroethylene copolymer film is preferred, and polyethylene terephthalate film is more preferred.

[0184] The thickness of the base film 2 is preferably 15 μm or more, more preferably 20 μm or more, and is preferably 50 μm or less, more preferably 40 μm or less. By making the thickness equal to or greater than the lower limit, the transportability during production of the multilayer body 1 tends to be further improved. Furthermore, by making the thickness equal to or less than the upper limit, the processing energy required for laser processing tends to be further reduced.

[0185] The resin sheet 3 has the same meaning as that described above in the section <Resin Sheet>, and the preferred range is also the same. That is, a preferred embodiment of the multilayer body of this embodiment is one in which the thickness of the layer in the B-stage state is 20 to 50 μm.

[0186] The cover film 4 is a film used to protect the resin sheet, and examples thereof 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, resin films such as polyimide film, conductive foils such as copper foil and aluminum foil, glass plates, SUS (Steel Use Stainless Steel) plates, FRP (Fiber-Reinforced Plastics), etc. Among these, one selected from the group consisting of polyethylene film, polypropylene film, polycarbonate film, polyethylene terephthalate film, and ethylene tetrafluoroethylene copolymer film is preferred, and polyethylene terephthalate film is more preferred.

[0187] The thickness of the cover film 4 is not particularly limited, but is preferably 15 μm or more, more preferably 25 μm or more, and is preferably 50 μm or less, more preferably 40 μm or less.

[0188] The method for producing the multilayer body of the first embodiment of this embodiment is not particularly limited, but may include, for example, a method in which a solution (varnish) obtained by dissolving the resin composition of this embodiment in a solvent is applied (coated) onto a substrate film and dried to obtain a multilayer body. More specifically, in this embodiment, the resin composition of this embodiment is applied to the surface of the substrate film 2 and semi-cured to form a multilayer body having the substrate film 2 and a resin sheet 3. Furthermore, it is preferable to provide a cover film 4 on the surface of the multilayer body having the substrate film 2 and the resin sheet 3 facing the resin sheet 3.

[0189] The method for applying (coating) the resin composition to the substrate film is not particularly limited, and examples thereof include a method in which a solution (varnish) in which the resin composition of the present embodiment is dissolved in a solvent is applied (coated) onto the substrate film using a bar coater, a die coater, a doctor blade, a baker applicator, or the like.

[0190] In the production of the multilayer body of the first 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 cause the resin composition to cure too quickly, it is preferable to adjust the drying (heating) temperature and drying (heating) time. The multilayer body can be used in an uncured state after the solvent has been dried, or it can be used in a B-stage state as needed. The drying (heating) temperature and drying (heating) time for removing the solvent and bringing the body into a B-stage state are the same as those described in the resin sheet section above. When providing a cover film 4 on the surface of the resin sheet 3 of a multilayer body having a base film 2 and a resin sheet 3, thermal lamination is preferred. The temperature at this time is preferably 90°C or higher, more preferably 100°C or higher, and preferably 130°C or lower, more preferably 120°C or lower.

[0191] The multilayer body of the first embodiment is preferably used for producing a printed wiring board. In particular, it is preferable to produce the multilayer body of the second embodiment from the multilayer body of the first embodiment.

[0192] In the multilayer body of the first embodiment as shown in Fig. 1, it is preferable that the peel force for peeling the base film 2 from the resin sheet 3 is greater than the peel force for peeling the cover film 4 from the resin sheet 3. By adopting such a configuration, a printed wiring board or the like can be produced more smoothly when producing the multilayer body of the second embodiment described later.

[0193] Next, a second embodiment of the multilayer body of this embodiment will be described. The multilayer body of the second embodiment has a glass core and an insulating resin layer, the insulating resin layer being a layer in a B-stage state formed from a thermosetting resin composition, the insulating resin layer having a thickness of 30 μm, and when a cylindrical mandrel bending test is performed, the maximum diameter of a cylinder at which at least one of cracking and peeling of the insulating resin layer (coating film) is observed is 30 mm or less, and the length of the crack when a load is applied to the insulating resin layer using a micro Vickers hardness tester is 1500 μm or less.

[0194] The multilayer body of the second embodiment will be described below with reference to FIG. 2. FIG. 2 is a cross-sectional schematic diagram showing an example of the multilayer body of the second embodiment, in which 10 denotes the multilayer body, 5 denotes the glass core, 6 denotes the insulating resin layer, and 7 denotes the cover film. In FIG. 2, the insulating resin layer 6 and the cover film 7 are provided on both sides of the glass core 5, but in the multilayer body of the second embodiment, the insulating resin layer 6 and the cover film 7 may be provided on only one side of the glass core 5. The multilayer body 10 of the second embodiment may or may not have another layer between the glass core 5 and the insulating resin layer 6 and / or between the insulating resin layer 6 and the cover film 7. Examples of layer structures of the multilayer body of the second embodiment include the following. Needless to say, the multilayer body of the second embodiment is not limited to these. Furthermore, the multilayer body of the second embodiment is preferably (1) to (3), more preferably (1) or (2), and even more preferably (1). (1) A multilayer body in which a glass core, an insulating resin layer not containing glass cloth (or a prepreg substrate), and a cover film that is a resin-based film are laminated. (2) A multilayer body in which a glass core, an insulating resin layer not containing glass cloth (or a prepreg substrate), and a cover film that is a conductor foil such as copper foil are laminated. (3) A multilayer body in which a glass core, an insulating resin layer (e.g., prepreg) containing a prepreg substrate such as glass cloth, and a cover film that is a resin-based film are laminated. (4) A multilayer body in which a glass core, an insulating resin layer (e.g., prepreg) containing a prepreg substrate such as glass cloth, and a cover film that is a conductor foil such as copper foil are laminated.

[0195] The insulating resin layer 6 in the multilayer body 10 of the second embodiment is a layer in a B-stage state formed from a thermosetting resin composition. In the multilayer body of the second embodiment, when a cylindrical mandrel bending test was performed with the insulating resin layer having a thickness of 30 μm, the maximum diameter of the cylinder where at least one of cracking and peeling of the insulating resin layer (coating) was observed was 30 mm or less. This small maximum diameter of the cylinder indicates that the insulating resin layer in the multilayer body of the second embodiment has high toughness. In the multilayer body of the second embodiment, the maximum diameter (mandrel diameter) of the cylinder where cracking of the insulating resin layer (coating) was observed is preferably 25 mm or less, more preferably 20 mm or less. Ideally, the lower limit is 0 mm, but even if it is 10 mm or more, the required performance is sufficiently met. Furthermore, in the multilayer body of the second embodiment, when a load is applied to the insulating resin layer using a micro Vickers hardness tester, the crack length is 1500 μm or less. This short crack length indicates high toughness. The length of the cracks (Vickers hardness) is preferably 1400 μm or less, more preferably 1300 μm or less, and the lower limit is ideally 0 μm, but even if it is 1000 μm or more, the required performance is sufficiently met.

[0196] In the multilayer body of the second embodiment, the mandrel diameter and Vickers hardness are measured when the insulating resin layer is 30 μm thick. However, this does not mean that the actual thickness of the insulating resin layer of the multilayer body of the second embodiment is 30 μm. The mandrel diameter and Vickers hardness are measured as described in the Examples below. However, if the insulating resin layer is not 30 μm thick, and if a 30 μm thick insulating resin layer manufactured using the same thermosetting resin composition as the thermosetting resin composition used to form the insulating resin layer satisfies the mandrel diameter and Vickers hardness, the insulating resin layer is deemed to satisfy the mandrel diameter and Vickers hardness when the insulating resin layer is 30 μm thick.

[0197] In order to satisfy these mandrel diameter and Vickers hardness requirements, for example, a resin sheet (insulating resin layer) may be formed using the resin composition of this embodiment. Therefore, the thermosetting resin composition may be the resin composition of this embodiment described in detail above, or it may not be the resin composition of this embodiment. Furthermore, as shown in FIG. 2 , when two insulating resin layers 6 are provided, one of them may be the resin composition of this embodiment, and the other may not be the resin composition of this embodiment. The thermosetting resin composition is preferably the resin composition of this embodiment described in detail above. Furthermore, the preferred range of the thermosetting resin composition is the same as the preferred range of the resin composition of this embodiment. Furthermore, the insulating resin layer is preferably a resin sheet (resin film) formed from the resin composition of this embodiment, semi-cured to a B-stage state. In this embodiment, one form of the insulating resin layer does not include glass cloth (or a prepreg base material). In this embodiment, even an insulating resin layer that does not include glass cloth has excellent flexibility and therefore high toughness. Furthermore, due to its excellent flexibility and high toughness, even a thin insulating resin layer is less likely to break or crack. Another embodiment of the insulating resin layer in this embodiment is a prepreg. In particular, a prepreg in which a substrate is impregnated with the resin composition of this embodiment is exemplified. Examples of the substrate include the substrate (prepreg substrate) described in the <Prepreg> section below, and glass cloth (glass woven fabric) is preferred.

[0198] The thickness of the insulating resin layer in the multilayer body of the second embodiment (thickness of the layer in the B-stage state) is preferably 20 μm or more, more preferably 25 μm or more, and is preferably 50 μm or less, more preferably 40 μm or less. By making the thickness equal to or greater than the lower limit, the thickness tolerance of the insulating resin layer tends to be reduced. Furthermore, by making the thickness equal to or less than the upper limit, the residual solvent in the insulating resin layer tends to be reduced.

[0199] The cover film 7 in the multilayer body of the second embodiment has the same definition as the cover film 4 in the multilayer body of the first embodiment, and the preferred range is also the same.

[0200] The glass core 5 is typically made of a glass material, and the composition of the glass is not particularly limited. Examples of glass include alkali-free glass, alkali glass, borosilicate glass, quartz glass, sapphire glass, and photosensitive glass. Any glass material containing silicate as a main component may be used, with alkali-free glass being preferred. The glass core 5 may have through holes for forming electrodes.

[0201] The thickness of the glass core 5 is preferably 100 μm or more, more preferably 200 μm or more, and is preferably 2000 μm or less, more preferably 1800 μm or less. By making the thickness equal to or greater than the lower limit, the transportability of the glass core tends to be improved. On the other hand, by making the thickness equal to or less than the upper limit, the crack resistance of a multilayer body using the glass core tends to be improved.

[0202] The multilayer body of the second embodiment is preferably produced using the multilayer body of the first embodiment. That is, it can be produced by peeling off the cover film 4 of the multilayer body of the first embodiment and laminating the multilayer body of the first embodiment to a glass core 5 so that the resin sheet 3 side of the multilayer body of the first embodiment is in contact with the glass core 5. As shown in FIG. 2 , when resin sheets 6 are provided on both sides of the glass core 5, it is preferable to peel off the cover films 4 of the two multilayer bodies of the first embodiment, and then place each of the multilayer bodies of the first embodiment on the glass core 5 so that the resin sheet 3 of the multilayer body of the first embodiment faces the glass core 5, and then perform heat pressing. In this embodiment, it is preferable to place the first multilayer body on the glass core 5 as described above, and then further harden the resin sheet (insulating resin layer) from the B-stage state, and then peel off the base film 7. That is, a preferred embodiment of the multilayer body of this embodiment is the multilayer body of the second embodiment in which the insulating resin layer (layer in the B-stage state) is further hardened.

[0203] The heating temperature for changing the insulating resin layer from a B-stage state to a C-stage state is preferably 150° C. or higher, more preferably 160° C. or higher, and even more preferably 170° C. or higher, and is preferably 220° C. or lower, more preferably 210° C. or lower, and even more preferably 200° C. or lower. The heating time is preferably 30 minutes or longer, more preferably 40 minutes or longer, and even more preferably 50 minutes or longer, and is preferably 180 minutes or shorter, more preferably 120 minutes or shorter, and even more preferably 90 minutes or shorter.

[0204] That is, the third multilayer body of this embodiment is a multilayer body in which the B-stage layer (insulating resin layer) in the multilayer body of the second embodiment has been further cured (for example, to a C-stage state). That is, the multilayer body of the first embodiment is usually produced with the insulating resin layer in a B-stage state, and an insulating resin layer is provided on the surface of the glass core to form a second multilayer body, which is then further cured. A multilayer body including a glass core and an insulating resin layer in a C-stage state is preferably used in the production of printed wiring boards.

[0205] <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 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.

[0206] The substrate is not particularly limited as long as it is a substrate used in various printed wiring board materials. Examples of the material of the substrate 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 that have been surface-treated with a silane coupling agent such as epoxy silane or amino silane are preferred. From the viewpoint of electrical properties, low-dielectric glass cloths made of glass fibers exhibiting a low relative dielectric constant and low dielectric dissipation factor, such as L-glass, NE-glass, NER-glass, and Q-glass, are more preferred. Examples of substrates with a low relative dielectric constant include substrates with a relative dielectric constant of 5.0 or less (preferably 3.0 to 4.9). Examples of substrates with a low dielectric dissipation factor include substrates with 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.

[0207] <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 reducing the dielectric loss tangent, the surface roughness Rz of the copper foil is more preferably 0.5 μm or more, even more preferably 0.6 μm or more, particularly preferably 0.7 μm or more, and more preferably 3.5 μm or less, even more preferably 3.0 μm or less, and particularly preferably 2.0 μm or less.

[0208] Examples of lamination molding methods include methods commonly used for molding laminates and multilayer boards for printed wiring boards. More specifically, methods using a multistage press, multistage vacuum press, continuous molding machine, autoclave molding machine, or the like, are used at a temperature of about 180 to 350°C, a heating time of about 100 to 300 minutes, and a surface pressure of 20 to 100 kg / cm. ２Examples of suitable methods include lamination molding at a thickness of about 1000 μm. Furthermore, a multilayer board can also be produced by combining the prepreg of this embodiment with a separately prepared inner layer wiring board and laminating and molding it. As a method for producing a multilayer board, for example, copper foil of about 35 μm is placed on both sides of one prepreg of this embodiment, and the laminate is formed using the above-mentioned molding method. Then, an inner layer circuit is formed, and this circuit is blackened 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. The multilayer board can be produced by laminating and molding it under the above-mentioned conditions, preferably under vacuum. The metal foil-clad laminate of this embodiment can be suitably used as a printed wiring board.

[0209] The metal foil-clad laminate of this embodiment preferably has a peel strength of 0.28 kN / m or more, more preferably 0.38 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. The upper limit of the peel strength is not particularly specified, but is, for example, 2.00 kN / m or more.

[0210] 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), moisture absorption heat resistance, peel strength against metal foil, as well as excellent properties such as heat resistance, desmear resistance, crack resistance, cured product appearance, and low thermal expansion.

[0211] <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 consisting 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 drilling processing for through holes and via holes, and then a plated metal film is formed on the wall surface of the hole to provide electrical continuity between the inner layer circuit and the metal foil for the outer layer circuit.The metal foil for the outer layer circuit is then etched to form the outer layer circuit, thereby producing a printed wiring board.

[0212] 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.

[0213] 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.

[0214] The resin composition of this embodiment can be suitably used in the manufacture of semiconductor package substrates, and can be used in the form of, for example, the second multilayer body having the glass core, a metal foil-clad laminate, a prepreg, or a resin sheet. Furthermore, semiconductor packages and organic interposers may have a wiring layer (semiconductor wiring layer) for connecting multiple semiconductor chips. The resin composition of this embodiment can also be used to form an insulating resin layer (inter-wiring insulating layer) that insulates this wiring layer. That is, the present invention can provide a resin composition used to form an insulating resin layer that insulates the wiring layer for connecting semiconductor chips. More specifically, in order to increase the density and performance of semiconductor packages, packaging configurations in which chips with different performance are mixed in a single package are being implemented. In such configurations, a fine wiring layer (semiconductor wiring layer) is required to electrically connect multiple semiconductor chips at high density. Typically, fine metal wiring (preferably copper wiring) with line widths and space widths of 5 μm or less is arranged within this wiring layer. The metal wiring is often formed using a trench method. The trench method is a method of forming a metal layer serving as wiring in a trench (groove) formed in an organic insulating layer using a laser or the like by plating or the like. Therefore, the shape of the wiring formed in the organic insulating layer follows the shape of the groove. The resin composition of this embodiment can form an insulating resin layer that insulates the wiring layer.

[0215] 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.

[0216] <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.

[0217] Synthesis Example 1: Synthesis of polyphenylene ether compound having terminal carbon-carbon unsaturated double bonds Synthesis of bifunctional phenylene ether oligomer CuBr was placed in a vertical reactor equipped with a stirrer, a thermometer, an air inlet tube, and a baffle. ２ 0.33 g (1.5 mmol) of copper bromide, 0.63 g (3.7 mmol) of N,N'-di-t-butylethylenediamine, 6.95 g (69 mmol) of n-butyldimethylamine, 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, 46.2 g (171 mmol) of 2,2',3,3',5,5'-hexamethyl-(1,1'-biphenyl)-4,4'-diol, 129.5 g (1,060 mmol) of 2,6-dimethylphenol, and CuBr were added to a separate vessel. ２0.33 g (1.5 mmol) of copper bromide, 0.63 g (3.7 mmol) of N,N'-di-t-butylethylenediamine, 6.95 g (69 mmol) of n-butyldimethylamine, 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.

[0218] <<Synthesis of Polyphenylene Ether Compound Having Terminal Carbon-Carbon Unsaturated Double Bonds>> A reactor equipped with a stirrer, thermometer, and 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% by 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 primarily 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.

[0219] Synthesis Example 2: Synthesis of polymer (va) having structural units represented by formula (V) 2.25 moles (292.9 g) of divinylbenzene, 1.32 moles (172.0 g) of ethylvinylbenzene, 11.43 moles (1190.3 g) of styrene, and 15.0 moles (1532.0 g) of n-propyl acetate were charged into a reactor, and 600 mmol of a boron trifluoride diethyl ether complex was added at 70°C, followed by a reaction for 4 hours. The polymerization reaction was terminated with an aqueous sodium bicarbonate solution, and the oil layer was washed three times with pure water. The mixture was then subjected to reduced pressure devolatilization at 60°C, and polymer (va) having structural units represented by formula (V) was recovered. The obtained polymer (va) having structural units represented by formula (V) was weighed, and it was confirmed that 860.8 g of polymer (va) having structural units represented by formula (V) was obtained.

[0220] The resulting polymer (va) having a structural unit represented by formula (V) had a number average molecular weight Mn of 2,060, a weight average molecular weight Mw of 30,700, and a monodispersity index Mw / Mn of 14.9. １３ C-NMR and １ By performing H-NMR analysis, resonance lines derived from each monomer unit used as a raw material were observed in polymer (va) having a structural unit represented by formula (V). Based on the NMR measurement results and GC analysis results, the proportion of each monomer unit (structural unit derived from each raw material) in polymer (va) having a structural unit represented by formula (V) was calculated as follows: structural units derived from divinylbenzene: 20.9 mol% (24.3 mass%), structural units derived from ethylvinylbenzene: 9.1 mol% (10.7 mass%), structural units derived from styrene: 70.0 mol% (65.0 mass%), and the proportion of structural units having residual vinyl groups derived from divinylbenzene was 16.7 mol% (18.5 mass%). The vinyl group equivalent was 241 g / eq.

[0221] <Measurement of 5% Weight Loss Temperature> A sample was heated in air from room temperature (25°C) at a rate of 10°C / min, and the temperature (unit: °C) at which a 5% mass loss was observed, assuming the initial mass of the sample to be 100% by mass, was measured. For the measurement, a simultaneous thermogravimetry and differential thermal analysis (TGDTA) apparatus, model number "DTG-60A" manufactured by Shimadzu Corporation, was used.

[0222] Example 1 25 parts by mass of maleimide compound (ma) (manufactured by DIC Corporation, "NE-X-9480S", compound represented by formula (M1)), 25 parts by mass of maleimide compound (mb) (manufactured by DIC Corporation, "NE-X-9500", maleimide compound (M7)), 10 parts by mass of the polyphenylene ether compound obtained in Synthesis Example 1 (corresponding to thermosetting resin (B)), 15 parts by mass of an allyl compound (manufactured by Shikoku Chemicals Corporation, L-DAIC, melting point 20°C, 5% weight loss temperature 243°C), 5 parts by mass of polymer (va) having a structural unit represented by formula (V) obtained in the above, 10 parts by mass of elastomer (MD3501, manufactured by Kraton Corporation), 10 parts by mass of phosphorus-based flame retardant (PX-200, manufactured by Daihachi Chemical Industry Co., Ltd.), 0.1 parts by mass of radical polymerization initiator (PERBUTYL P, peroxide, manufactured by NOF Corporation), and 0.1 parts by mass of curing accelerator (2E4MZ, imidazole catalyst, manufactured by Shikoku Chemical Industry Co., Ltd.) were mixed and diluted with ethyl ethyl ketone to a solids content of 65% by mass to obtain a varnish. The blend amounts of each component mentioned above are values ​​based on the solids content. The MD3501 manufactured by Kraton is an elastomer containing a polymer block containing p-methylstyrene units and hydrogenated or partially hydrogenated butadiene units and / or hydrogenated or partially hydrogenated isoprene units. The Tg (glass transition temperature) of MD3501 was −10° C. (the maximum temperature of the Tan δ peak measured by the DMA method).

[0223] Maleimide compound (ma)

[0224] <Production of a multilayer body (1) having a 30 μm-thick resin sheet> The varnish obtained above was applied to the surface of a base film (material: PET, manufacturer: Unitika, product number: TRF, thickness: 38 μm), dried at 130° C. for 5 minutes, and a cover film (material: PET, manufacturer: Lintec, product number: AL5, thickness: 38 μm) was placed on the varnished side using a thermal laminator at 110° C. to obtain a multilayer body (1) (base film / resin sheet / cover film) having a resin sheet in a B-stage state. The thickness of the resin sheet was 30 μm.

[0225] <Cylindrical Mandrel Bending Test> The cover film of the multilayer body (1) obtained above was peeled off, and the maximum diameter of the mandrel where at least one of cracking and peeling was observed for the resin sheet / substrate film was measured using a cylindrical mandrel bending tester. The cylindrical mandrel bending tester used was manufactured by Cortec Co., Ltd. The evaluation was performed as follows: A: 30 mm or less B: More than 30 mm and 50 mm or less C: More than 50 mm

[0226] <Vickers Hardness (HV 0.01)> The cover film of the multilayer body (1) obtained above was peeled off, and the body was placed on a glass slide. The test piece was fixed to the glass slide with a cyanoacrylate instant adhesive (Aron Alpha (registered trademark) 201 (trade name), manufactured by Toagosei Co., Ltd.). Using a micro-Vickers hardness tester, a load of 2 kgf was applied to 10 locations with a holding time of 15 seconds. The 10 locations were checked for the presence or absence of cross-shaped cracks. If cracks occurred, the vertical and horizontal lengths of the cracks were measured. If no cracks were observed, the crack length was recorded as 0. The average crack length was calculated from both the vertical and horizontal lengths of the cracks at the 10 locations. The micro-Vickers hardness tester used was HMV-G (trade name) manufactured by Shimadzu Corporation. Evaluation was performed as follows. A: 1500 μm or less B: More than 1500 μm and less than 2500 μm C: More than 2500 μm

[0227] <Coefficient of linear thermal expansion (CTE)> The cover film was peeled off from the multilayer body (1) obtained above, and the multilayer body (1) was placed on the surface of a glass core (material: glass, manufacturer: CORNING, product number: EAGLE XG, thickness: 500 μm) so that the resin sheet side was in contact with the surface, and heated at 180°C for 1 hour to obtain a multilayer body (2) (substrate film / resin sheet (cured product) / glass core). After peeling the substrate film from the obtained multilayer body (2), the obtained cured product was peeled off from the glass core, and the sample was downsized to 3.0 mm square. The coefficient of thermal expansion of the sample was measured by the TMA (Thermo-Mechanical Analysis) method in accordance with JIS C 6481 5.19, and the value was determined. The unit is expressed in ppm / °C. The thermomechanical analyzer used was a TMAQ400 manufactured by TA Instruments Co., Ltd., and the sample was heated from 25°C to 303°C at a rate of 10°C per minute, cooled, and then heated again from 25°C to 303°C at a rate of 10°C per minute to measure the thermal expansion coefficient from 60 to 120°C.

[0228] <Dielectric Properties> The cover film of the multilayer body (1) obtained above was peeled off, and the multilayer body (1) was placed on the surface of a glass core (material: glass, manufacturer: CORNING, product number: EAGLE XG, thickness: 500 μm) so that the resin sheet side was in contact with the surface, and heated at 180°C for 1 hour to obtain a multilayer body (2) (substrate film / resin sheet (cured product) / glass core). After peeling the substrate film from the obtained multilayer body (2), the obtained cured product was peeled off from the glass core, and the sample was downsized to a width of 1.0 mm and a length of 100 mm. The relative dielectric constant (Dk) at a frequency of 10 GHz was measured using a perturbation method cavity resonator. The measurement temperature was 23°C. The perturbation method cavity resonator used was a P5005A manufactured by Keysight Technologies, Inc.

[0229] Example 2 The same procedure was carried out as in Example 1, except that the allyl compound was replaced with the same amount of methacrylic acid ester (NK Ester DCP, manufactured by Shin-Nakamura Chemical Co., Ltd., melting point -20°C, 5% weight loss temperature 206°C).

[0230] Example 3 The same procedures as in Example 1 were carried out, except that the content of the maleimide compound (ma) was 30 parts by mass, the content of the maleimide compound (mb) was 30 parts by mass, the allyl compound was changed to the same amount of a methacrylic acid ester (NK Ester DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.), the polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 2 was not blended, and the content of the elastomer (MD3501, manufactured by Kraton) was changed to 5 parts by mass.

[0231] Example 4 The same procedure as in Example 1 was repeated, except that the content of the maleimide compound (ma) was changed to 30 parts by mass, the allyl compound was changed to the same amount of a methacrylic acid ester (NK Ester DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.), and the polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 2 was not added.

[0232] Example 5 The same procedure as in Example 1 was carried out except that the content of the maleimide compound (ma) was 30 parts by mass, the content of the maleimide compound (mb) was 30 parts by mass, no allyl compound was added, 10 parts by mass of a methacrylic acid ester (NK Ester DCP, manufactured by Shin-Nakamura Chemical Co., Ltd.) was added, and the polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 2 was not added.

[0233] Comparative Example 1 The same procedure was carried out as in Example 1, except that the content of the maleimide compound (ma) was 27.5 parts by mass, the content of the maleimide compound (mb) was 27.5 parts by mass, no allyl compound was added, and the content of the elastomer (MD3501, manufactured by Kraton) was changed to 20 parts by mass.

[0234] Comparative Example 2 The same procedure as in Example 1 was carried out except that the content of the maleimide compound (ma) was 35 parts by mass, the content of the maleimide compound (mb) was 30 parts by mass, and no allyl compound was added.

[0235] Comparative Example 3 The same procedure was carried out as in Example 1, except that the content of the maleimide compound (ma) was 30 parts by mass, the content of the maleimide compound (mb) was 30 parts by mass, no allyl compound was added, and the content of the elastomer (MD3501, manufactured by Kraton) was changed to 15 parts by mass.

[0236] Comparative Example 4 The same procedure as in Example 1 was carried out except that the content of the maleimide compound (ma) was 32.5 parts by mass, the content of the maleimide compound (mb) was 32.5 parts by mass, and no allyl compound was added.

[0237] Comparative Example 5 The same procedure as in Example 1 was carried out, except that the content of the maleimide compound (ma) was changed to 35 parts by mass, the content of the maleimide compound (mb) was changed to 35 parts by mass, and the allyl compound and the polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 2 were not blended.

[0238] Comparative Example 6 The same procedures as in Example 1 were carried out, except that the content of the maleimide compound (ma) was changed to 37.5 parts by mass, the content of the maleimide compound (mb) was changed to 37.5 parts by mass, the allyl compound and the polymer (va) having a structural unit represented by formula (V) obtained in Synthesis Example 2 were not blended, and the content of the elastomer (MD3501, manufactured by Kraton Corporation) was changed to 5 parts by mass.

[0239]

[0240]

[0241] Although the present invention has been described in detail with reference to specific embodiments, it will be apparent to those skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

[0242] REFERENCE SIGNS LIST 1 Multilayer body 2 Base film 3 Resin sheet 4 Cover film 10 Multilayer body 5 Glass core 6 Insulating resin layer 7 Cover film

Claims

1. A resin composition comprising a thermosetting compound (A) having a melting point of 30°C or lower and a 5% weight loss temperature of 150°C or higher, and a thermosetting compound (B) capable of undergoing a polymerization reaction with the thermosetting compound (A) (excluding compounds that fall under the category of thermosetting compound (A)).

2. The resin composition according to claim 1, wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond.

3. The resin composition according to claim 1, wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond is at least one selected from the group consisting of compounds having two or more (meth)acryloyl groups in the molecule and compounds having two or more (meth)allyl groups in the molecule.

4. The resin composition according to claim 1, wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond is a compound having two or more methacryloyl groups in the molecule.

5. The resin composition according to claim 1, wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the compound having a terminal carbon-carbon unsaturated double bond includes a compound represented by formula (A-1) and / or a compound represented by formula (A-2). Formula (A-1) (In formula (A-1), R Ａ represents a hydrogen atom or a substituent. (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａ represents a hydrogen atom or a substituent.

6. A resin composition according to any one of claims 1 to 5, wherein the content of the thermosetting compound (A) is 2 to 30 parts by mass per 100 parts by mass of resin solids in the resin composition.

7. The resin composition according to any one of claims 1 to 5, wherein the thermosetting compound (B) comprises at least one selected from the group consisting of epoxy compounds, cyanate ester compounds, compounds (b) having a terminal carbon-carbon unsaturated double bond, maleimide compounds, and nadimide compounds.

8. The resin composition according to any one of claims 1 to 5, wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) includes a maleimide compound.

9. The resin composition according to any one of claims 1 to 5, wherein the thermosetting compound (A) includes a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) includes a compound represented by formula (M1) and / or a compound having a structure represented by formula (M7). (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 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, 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. * represents a bonding position.) 10. The resin composition according to any one of claims 1 to 5, wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) comprises a maleimide compound, and the content of the compound having a terminal carbon-carbon unsaturated double bond is 5 to 50 parts by mass per 100 parts by mass of the total of the compound having a terminal carbon-carbon unsaturated double bond and the maleimide compound.

11. The resin composition according to any one of claims 1 to 5, further comprising an elastomer containing a polymer block (a1) containing a styrene compound unit having a radical reactive group and a conjugated diene compound unit.

12. The resin composition according to claim 11, wherein the conjugated diene compound units are hydrogenated and / or partially hydrogenated.

13. The resin composition according to claim 11, wherein the content of the elastomer is 0.5 to 30 parts by mass per 100 parts by mass of the resin solid content in the resin composition.

14. The resin composition according to any one of claims 1 to 5, wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, the compound having a terminal carbon-carbon unsaturated double bond being a compound represented by formula (A-1) and / or a compound represented by formula (A-2) and including a compound having two carbon-carbon unsaturated double bonds in one molecule, the thermosetting compound (B) comprises a compound represented by formula (M1) and / or a compound having a structure represented by formula (M7), and further comprises an elastomer containing a polymer block (a1) including a styrene compound unit having a radical reactive group and a conjugated diene compound unit, and the conjugated diene compound unit is hydrogenated and / or partially hydrogenated. Formula (A-1) (In formula (A-1), R Ａ represents a hydrogen atom or a substituent. (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａ represents a hydrogen atom or a substituent. (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 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, 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. * represents a bonding position.) 15. The resin composition according to any one of claims 1 to 5, further comprising a radical polymerization initiator.

16. The resin composition according to any one of claims 1 to 5, further comprising an imidazole-based curing accelerator.

17. The resin composition according to claim 1, wherein the thermosetting compound (A) comprises a compound having a terminal carbon-carbon unsaturated double bond, and the thermosetting compound (B) comprises a maleimide compound, the content of the compound having a terminal carbon-carbon unsaturated double bond is 5 to 50 parts by mass per 100 parts by mass of the total of the compound having a terminal carbon-carbon unsaturated double bond and the maleimide compound, the content of the thermosetting compound (A) is 2 to 30 parts by mass per 100 parts by mass of resin solids in the resin composition, the resin composition further comprises an elastomer containing a polymer block (a1) including a styrene compound unit and a conjugated diene compound unit having a radical reactive group, the content of the elastomer is 0.5 to 30 parts by mass per 100 parts by mass of resin solids in the resin composition, the resin composition further comprises a radical polymerization initiator, and the resin composition further comprises an imidazole-based curing accelerator.

18. The resin composition according to claim 17, wherein the compound having a terminal carbon-carbon unsaturated double bond is a compound represented by formula (A-1) and / or a compound represented by formula (A-2), and includes a compound having two carbon-carbon unsaturated double bonds in one molecule, the thermosetting compound (B) includes a compound represented by formula (M1) and / or a compound having a structure represented by formula (M7), and the conjugated diene compound unit is a hydrogenated and / or partially hydrogenated product. Formula (A-1) (In formula (A-1), R Ａ represents a hydrogen atom or a substituent. (In formula (A-2), Cy １ represents an alicyclic structure; each L independently represents a single bond or a linking group; each Po independently represents a carbon-carbon unsaturated double bond group; R Ａ represents a hydrogen atom or a substituent. (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 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group; ３ , R ４ , R ５ and R ６ each 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 R ７ 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 having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms; an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms; a cycloalkyl group having 3 to 10 carbon atoms; a halogen atom; a hydroxyl group; or a mercapto group, 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. * represents a bonding position.) 19. A resin sheet formed from the resin composition according to any one of claims 1 to 5, 17 and 18.

20. The resin sheet according to claim 19, which is in a B-stage state.

21. A multilayer body comprising a substrate film, a resin sheet, and a cover film laminated in the stated order, the resin sheet being a layer in a B-stage state formed from the resin composition described in any one of claims 1 to 5, 17, and 18.

22. The multilayer body according to claim 21, wherein the thickness of the B-staged layer is 20 to 50 μm.

23. A multilayer body having a glass core and an insulating resin layer, the insulating resin layer being a B-stage layer formed from a thermosetting resin composition, wherein when a cylindrical mandrel bending test is conducted with the insulating resin layer having a thickness of 30 μm, the maximum diameter of the cylinder in which at least one of cracking and peeling of the insulating resin layer is observed is 30 mm or less, and when a load is applied to the insulating resin layer using a micro Vickers hardness tester, the length of the crack is 1500 μm or less.

24. The multilayer body according to claim 23, wherein the thermosetting resin composition is the resin composition according to any one of claims 1 to 5, 17 and 18.

25. The multilayer body according to claim 21, wherein the thickness of the B-staged layer is 20 to 50 μm.

26. The multilayer body of claim 21, wherein the B-staged layer is further cured.

27. The resin composition according to any one of claims 1 to 5, 17 and 18, which is used to form an inter-wiring insulating layer that insulates wiring layers for connecting semiconductor chips.

28. A printed wiring board comprising an insulating layer and a conductor layer disposed on the surface of said insulating layer, wherein said insulating layer comprises a layer formed from a resin composition according to any one of claims 1 to 5, 17 and 18.

29. A semiconductor device comprising the printed wiring board according to claim 28.

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