JP7615933B2 - Resin composition - Google Patents

Description

The present invention relates to a resin composition. Furthermore, the present invention relates to a resin sheet, a printed wiring board, and a semiconductor device obtained by using the resin composition.

A known manufacturing technique for printed wiring boards is a build-up method in which insulating layers and conductor layers are alternately stacked. In build-up manufacturing methods, the insulating layers are generally formed by curing a resin composition. An example of such a resin composition is the resin composition disclosed in Patent Document 1.

JP 2019-66792 A

The cured product formed by curing the resin composition can be used as an insulating layer for the printed wiring board of a semiconductor device. For this reason, it is required that the dielectric tangent of the cured product is low. In addition, it is desirable that the insulating layer formed from this cured product has excellent peel strength between itself and the conductor layer, and also has excellent adhesion to the copper foil.

The present invention has been devised in view of the above problems, and aims to provide a resin composition capable of producing a cured product having low dielectric properties and excellent peel strength between the conductor layer, copper foil adhesion, and copper foil adhesion after HAST testing; a resin sheet having a resin composition layer containing the resin composition; a printed wiring board including an insulating layer formed of a cured product of the resin composition; and a semiconductor device including the printed wiring board.

As a result of intensive research aimed at solving the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using (A-1) a liquid epoxy resin, (A-2) a solid epoxy resin, (B) an inorganic filler, and (C) an active ester compound having a skeleton in which a naphthalene skeleton and a biphenyl skeleton are linked via a methylene chain, and have thus completed the present invention.

That is, the present invention includes the following.
[1] (A-1) liquid epoxy resin,
(A-2) a solid epoxy resin,
A resin composition comprising: (B) an inorganic filler; and (C) an active ester compound having a skeleton in which a naphthalene skeleton and a biphenyl skeleton are bonded by a methylene chain.
[2] The resin composition according to [1], wherein the content of the component (B) is 70% by mass or more, based on 100% by mass of non-volatile components in the resin composition.
[3] The resin composition according to [1] or [2], wherein the ratio of the component (A-1) to the component (A-2) is 1:0.1 to 1:10 by mass.
[4] The resin composition according to any one of [1] to [3], wherein the content of the component (C) is 20 mass% or less, when the total amount of non-volatile components in the resin composition is 100 mass%.
[5] The resin composition according to any one of [1] to [4], further comprising (D) a thermosetting resin.
[6] The resin composition according to any one of [1] to [5], further comprising (E) a curing agent.
[7] The resin composition according to any one of [1] to [6], which is for forming an insulating layer.
[8] The resin composition according to any one of [1] to [7], which is for forming an insulating layer for forming a conductor layer.
[9] A resin sheet comprising a support and a resin composition layer provided on the support, the resin composition layer comprising the resin composition according to any one of [1] to [8].
[10] A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to any one of [1] to [8].
[11] A semiconductor device comprising the printed wiring board according to [10].

According to the present invention, it is possible to provide a resin composition capable of producing a cured product having low dielectric properties and excellent peel strength, copper foil adhesion, and copper foil adhesion after HAST testing; a resin sheet having a resin composition layer containing the resin composition; a printed wiring board including an insulating layer formed of a cured product of the resin composition; and a semiconductor device including the printed wiring board.

The present invention will be described below with reference to embodiments and examples. However, the present invention is not limited to the embodiments and examples shown below, and may be modified as desired without departing from the scope of the claims of the present invention and their equivalents.

[Resin composition]
The resin composition of the present invention comprises (A-1) a liquid epoxy resin, (A-2) a solid epoxy resin, (B) an inorganic filler, and (C) an active ester compound having a skeleton in which a naphthalene skeleton and a biphenyl skeleton are bonded by a methylene chain. With such a resin composition, it is possible to obtain a cured product having a low dielectric tangent, excellent peel strength, copper foil adhesion, and copper foil adhesion after HAST testing. In addition, the resin composition can usually obtain a cured product having a high elongation at break, a low arithmetic mean roughness Ra, and suppressed lamination irregularities.

The resin composition may further contain optional components such as (D) a thermoplastic resin, (E) a curing agent, (F) a curing accelerator, and (G) other additives, as necessary. Each component contained in the resin composition will be described in detail below. Note that the (A-1) component and the (A-2) component are sometimes collectively referred to as the (A) component, i.e., the (A) epoxy resin.

<(A-1) Liquid epoxy resin>
The resin composition contains, as component (A-1), a liquid epoxy resin (A-1). The liquid epoxy resin (A-1) is an epoxy resin that is liquid at a temperature of 20°C.

The (A-1) component is preferably a liquid epoxy resin having two or more epoxy groups in one molecule, and more preferably an aromatic liquid epoxy resin having two or more epoxy groups in one molecule. From the viewpoint of obtaining the effects of the present invention significantly, the proportion of the liquid epoxy resin having two or more epoxy groups in one molecule of the (A-1) component is preferably 20% by mass or more, more preferably 30% by mass or more, and particularly preferably 40% by mass or more, based on 100% by mass of the non-volatile components of the (A-1) component.

Examples of the (A-1) component include bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and bisphenol AF-type epoxy resins; naphthalene-type epoxy resins; glycidyl ester-type epoxy resins; glycidyl amine-type epoxy resins; phenol novolac-type epoxy resins; alicyclic epoxy resins having an ester skeleton; cyclohexane-type epoxy resins; cyclohexane dimethanol-type epoxy resins; glycidyl amine-type epoxy resins; and epoxy resins having a butadiene structure. Among these, from the viewpoint of obtaining the effects of the present invention significantly, bisphenol-type epoxy resins and naphthalene-type epoxy resins are preferred, and bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, and naphthalene-type epoxy resins are more preferred.

Specific examples of the (A-1) component include DIC's "HP-4032", "HP-4032-D", and "HP-4032-SS" (naphthalene type epoxy resins); Mitsubishi Chemical's "828US", "jER828EL", "825", and "Epicoat 828EL" (bisphenol A type epoxy resins); Mitsubishi Chemical's "jER807" and "1750" (bisphenol F type epoxy resins); Mitsubishi Chemical's "jER152" (phenol novolac type epoxy resin); Mitsubishi Chemical's "630" and "630LSD" (glycidylamine type epoxy resins). resin); "ZX1059" (a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel Chemical &Material; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX; "Celloxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Daicel; "PB-3600" (epoxy resin having a butadiene structure) manufactured by Daicel; "ZX1658" and "ZX1658GS" (liquid 1,4-glycidylcyclohexane type epoxy resin) manufactured by Nippon Steel Chemical & Material. These may be used alone or in combination of two or more types.

The epoxy equivalent of component (A-1) is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., even more preferably 80 g/eq. to 2000 g/eq., and even more preferably 110 g/eq. to 1000 g/eq. Within this range, the crosslink density of the cured product of the resin composition layer is sufficient, and an insulating layer with small surface roughness can be obtained. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of component (A-1) is preferably 100 to 5,000, more preferably 200 to 3,000, and even more preferably 250 to 1,500, from the viewpoint of significantly achieving the desired effects of the present invention.

From the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulating reliability, the content of component (A-1) is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass. From the viewpoint of significantly obtaining the desired effects of the present invention, the upper limit of the content of component (A-1) is preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less.

<(A-2) Solid Epoxy Resin>
The resin composition contains, as component (A-2), a solid epoxy resin (A-2). The solid epoxy resin is an epoxy resin that is solid at a temperature of 20°C.

As the solid epoxy resin (A-2), a solid epoxy resin having two or more epoxy groups in one molecule is preferred, and an aromatic solid epoxy resin having two or more epoxy groups in one molecule is more preferred. From the viewpoint of obtaining a significant effect of the present invention, the proportion of the solid epoxy resin having two or more epoxy groups in one molecule of the (A-2) component is preferably 20% by mass or more, more preferably 30% by mass or more, and particularly preferably 40% by mass or more, based on 100% by mass of the non-volatile components of the (A-2) component.

Examples of the (A-2) component include bixylenol type epoxy resins, naphthalene type epoxy resins, naphthalene type tetrafunctional epoxy resins, cresol novolac type epoxy resins, dicyclopentadiene type epoxy resins, trisphenol type epoxy resins, naphthol type epoxy resins, biphenyl type epoxy resins, biphenyl aralkyl type epoxy resins, naphthylene ether type epoxy resins, anthracene type epoxy resins, naphthol aralkyl skeleton epoxy resins, bisphenol A type epoxy resins, bisphenol AF type epoxy resins, and tetraphenylethane type epoxy resins. Among these, naphthalene type epoxy resins, biphenyl aralkyl type epoxy resins, and naphthol aralkyl skeleton epoxy resins are preferred.

Specific examples of the (A-2) component include DIC's "HP4032H" (naphthalene type epoxy resin); DIC's "HP-4700" and "HP-4710" (naphthalene type tetrafunctional epoxy resin); DIC's "N-690" (cresol novolac type epoxy resin); DIC's "N-695" (cresol novolac type epoxy resin); DIC's "HP-7200", "HP-7200HH", and "HP-7200H" (dicyclopentadiene type epoxy resin). epoxy resin); "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", and "HP6000" (naphthylene ether type epoxy resin) manufactured by DIC Corporation; "EPPN-502H" (trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC7000L" (naphthol novolac type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.; "NC3000H", "NC3000", "NC-3000L", and "NC3000H" manufactured by Nippon Kayaku Co., Ltd. 100" (biphenyl aralkyl type epoxy resin); "ESN475V" (naphthol aralkyl skeleton epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "ESN485" (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical & Material Co., Ltd.; "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YX4000HK" (bixylenol type epoxy resin) manufactured by Mitsubishi Chemical Corporation; Examples of such epoxy resins include "YX8800" (anthracene type epoxy resin) manufactured by Osaka Gas Chemicals Co., Ltd.; "PG-100" and "CG-500" manufactured by Osaka Gas Chemicals Co., Ltd.; "YL7760" (bisphenol AF type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation; "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation; and "jER1031S" (tetraphenylethane type epoxy resin) manufactured by Mitsubishi Chemical Corporation. These may be used alone or in combination of two or more types.

The epoxy equivalent of the (A-2) component is preferably 50 g/eq. to 5000 g/eq., more preferably 50 g/eq. to 3000 g/eq., even more preferably 80 g/eq. to 2000 g/eq., and even more preferably 110 g/eq. to 1000 g/eq. When it is in this range, the crosslink density of the cured product of the resin composition layer is sufficient, and an insulating layer with small surface roughness can be obtained. The epoxy equivalent is the mass of an epoxy resin containing one equivalent of epoxy groups. This epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of component (A-2) is preferably 100 to 5,000, more preferably 200 to 3,000, and even more preferably 250 to 1,500, from the viewpoint of significantly achieving the desired effects of the present invention.

The content of component (A-2) is preferably 1% by mass or more, more preferably 2% by mass or more, and even more preferably 3% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass, from the viewpoint of obtaining an insulating layer that exhibits good mechanical strength and insulating reliability. The upper limit of the content of component (A-2) is preferably 10% by mass or less, more preferably 8% by mass or less, and particularly preferably 5% by mass or less, from the viewpoint of significantly obtaining the desired effects of the present invention.

The ratio by mass of the liquid epoxy resin (A-1) to the solid epoxy resin (A-2) (liquid epoxy resin:solid epoxy resin) is preferably 1:0.1 to 1:10, more preferably 1:0.5 to 1:5, and particularly preferably 1:1 to 1:3. By having the ratio of the components (A-1) and (A-2) in this range, the desired effects of the present invention can be significantly obtained.

<(B) Inorganic filler>
The resin composition contains an inorganic filler (B) as the component (B). By containing the inorganic filler (B) in the resin composition, it is possible to obtain a cured product having excellent dielectric properties. .

As the material of the inorganic filler, an inorganic compound is used. Examples of the material of the inorganic filler include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica. In addition, spherical silica is preferable as the silica. The (B) component may be used alone or in combination of two or more types.

Commercially available products of component (B) include, for example, "UFP-30" manufactured by Denka Chemical Industry Co., Ltd.; "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumitomo Metal Materials Co., Ltd.; "YC100C", "YA050C", "YA050C-MJE", and "YA010C" manufactured by Admatechs Co., Ltd.; "UFP-30" manufactured by Denka Company, Ltd.; "Silfil NSS-3N", "Silfil NSS-4N", and "Silfil NSS-5N" manufactured by Tokuyama Corporation; "SC2500SQ", "SO-C4", "SO-C2", "SO-C1", and "SC2050-SXF" manufactured by Admatechs Co., Ltd.

From the viewpoint of significantly obtaining the desired effects of the present invention, the average particle size of component (B) is preferably 0.01 μm or more, more preferably 0.05 μm or more, and particularly preferably 0.1 μm or more, and is preferably 5 μm or less, more preferably 2 μm or less, and even more preferably 1 μm or less.

The average particle size of component (B) can be measured by a laser diffraction/scattering method based on the Mie scattering theory. Specifically, a particle size distribution of the inorganic filler is created on a volume basis using a laser diffraction/scattering particle size distribution measuring device, and the median diameter is used as the average particle size. The measurement sample can be prepared by weighing 100 mg of inorganic filler and 10 g of methyl ethyl ketone into a vial and dispersing it ultrasonically for 10 minutes. The measurement sample is measured using a laser diffraction particle size distribution measuring device with blue and red light wavelengths as the light source, and the volume-based particle size distribution of the inorganic filler is measured using a flow cell method, and the average particle size is calculated as the median diameter from the particle size distribution obtained. Examples of laser diffraction particle size distribution measuring devices include the "LA-960" manufactured by Horiba, Ltd. and the "SALD-2200" manufactured by Shimadzu Corporation.

From the viewpoint of significantly obtaining the desired effects of the present invention, the specific surface area of component (B) is preferably 1 m ² /g or more, more preferably 2 m ² /g or more, and particularly preferably 3 m ² /g or more. There is no particular upper limit, but it is preferably 60 m ² /g or less, 50 m ² /g or less, or 40 m ² /g or less. The specific surface area is obtained by measuring the specific surface area of the inorganic filler using a BET fully automatic specific surface area measuring device (Macsorb HM-1210 manufactured by Mountech Co., Ltd.) by adsorbing nitrogen gas onto the surface of the sample and calculating the specific surface area using the BET multipoint method.

From the viewpoint of improving moisture resistance and dispersibility, it is preferable that the (B) component is treated with a surface treatment agent. Examples of the surface treatment agent include fluorine-containing silane coupling agents such as 3,3,3-trifluoropropyltrimethoxysilane; aminosilane-based coupling agents such as 3-aminopropyltriethoxysilane, N-phenyl-8-aminooctyl-trimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; epoxysilane-based coupling agents such as 3-glycidoxypropyltrimethoxysilane; mercaptosilane-based coupling agents such as 3-mercaptopropyltrimethoxysilane; silane-based coupling agents; alkoxysilanes such as phenyltrimethoxysilane; organosilazane compounds such as hexamethyldisilazane; titanate-based coupling agents, and the like. In addition, the surface treatment agent may be used alone or in any combination of two or more types.

Examples of commercially available surface treatment agents include Shin-Etsu Chemical's "KBM403" (3-glycidoxypropyltrimethoxysilane), Shin-Etsu Chemical's "KBM803" (3-mercaptopropyltrimethoxysilane), Shin-Etsu Chemical's "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical's "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical's "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical's "KBM103" (phenyltrimethoxysilane), Shin-Etsu Chemical's "KBM-4803" (long-chain epoxy-type silane coupling agent), and Shin-Etsu Chemical's "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane).

From the viewpoint of improving the dispersibility of the inorganic filler, it is preferable that the degree of surface treatment with the surface treatment agent falls within a specified range. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 parts by mass to 5 parts by mass of the surface treatment agent, more preferably with 0.2 parts by mass to 3 parts by mass, and more preferably with 0.3 parts by mass to 2 parts by mass.

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. From the viewpoint of improving the dispersibility of the inorganic filler, the amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, and even more preferably 0.2 mg/m ² or more. On the other hand, from the viewpoint of suppressing the increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, it is preferably 1 mg/m ² or less, more preferably 0.8 mg/m ² or less, and even more preferably 0.5 mg/m ² or less.

The carbon amount per unit surface area of component (B) can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler that has been surface-treated with the surface treatment agent, and ultrasonic cleaning is performed at 25°C for 5 minutes. After removing the supernatant and drying the solids, the carbon amount per unit surface area of the inorganic filler can be measured using a carbon analyzer. An example of a carbon analyzer that can be used is the "EMIA-320V" manufactured by Horiba, Ltd.

From the viewpoint of obtaining a significant effect of the present invention, the content of component (B) is preferably 70% by mass or more, more preferably 71% by mass or more, even more preferably 72% by mass or more, and preferably 90% by mass or less, preferably 85% by mass or less, more preferably 85% by mass or less, even more preferably 80% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

<(C) Active Ester Compound Having a Skeleton in Which a Naphthalene Skeleton and a Biphenyl Skeleton are Bonded via a Methylene Chain>
The resin composition contains, as the component (C), an active ester compound having a skeleton in which a naphthalene skeleton and a biphenyl skeleton are bonded by a methylene chain. The component (C) has a naphthalene skeleton, which is a rigid structure, and therefore can increase the rigidity of the cured product of the resin composition. In addition, the biphenyl skeleton of the component (C) rotates the single bond of the biphenyl molecule, and therefore can increase the toughness of the cured product of the resin composition. Therefore, the component (C) can improve the plating peel strength and copper foil adhesion, and furthermore, it is usually possible to improve the elongation at break.

As component (C), for example, a compound obtained by reacting a compound containing a phenol skeleton with a compound containing a biphenyl skeleton having a methylene chain to obtain a reaction product, and then reacting the reaction product with an aromatic polycarboxylic acid or its acid halide can be used.

From the viewpoint of reacting with an aromatic polycarboxylic acid or an acid halide thereof, it is preferable that the compound containing a phenol skeleton has a phenolic hydroxyl group. Examples of the compound containing a phenol skeleton include naphthol compounds such as 1-naphthol and 2-naphthol; and compounds having one or more substituents on the aromatic nucleus of these compounds. Examples of the substituent on the aromatic nucleus include aliphatic hydrocarbon groups such as methyl, ethyl, vinyl, propyl, butyl, pentyl, hexyl, cyclohexyl, heptyl, octyl, and nonyl; alkoxy groups such as methoxy, ethoxy, propyloxy, and butoxy; halogen atoms such as fluorine, chlorine, and bromine; aryl groups such as phenyl, naphthyl, and anthryl, and aryl groups in which the aliphatic hydrocarbon groups, alkoxy groups, and halogen atoms are substituted on these aromatic nuclei; phenylmethyl, phenylethyl, naphthylmethyl, and naphthylethyl groups, and aralkyl groups in which the aliphatic hydrocarbon groups, alkoxy groups, and halogen atoms are substituted on these aromatic nuclei. Among these, naphthol compounds are preferred as compounds containing a phenol skeleton from the viewpoint of improving the dielectric tangent, and 1-naphthol or 2-naphthol is more preferred.

（式（１）中、Ｚ^１及びＺ^２は、それぞれ独立にハロメチル基、ヒドロキシメチル基、又はアルキルオキシメチル基を表す。Ｒ^ｃ１１及びＲ^ｃ１２は、それぞれ独立に脂肪族炭化水素基、アルコキシ基、ハロゲン原子、アリール基又はアラルキル基を表す。ｉ及びｊはそれぞれ独立に０又は１～４の整数を表す。） As the compound containing a biphenyl skeleton having a methylene chain, a compound having a biphenyl skeleton and a reactive group having a methylene chain that can react with any of a compound containing a phenol skeleton, an aromatic polycarboxylic acid, and an acid halide thereof can be used. As the reactive group having a methylene chain, a reactive group that can react with a compound containing a phenol skeleton to form a methylene chain (-CH ₂ -) can be used. As such a compound, for example, a compound represented by the following formula (1) can be used.

(In formula (1), ^Z1 and ^Z2 each independently represent a halomethyl group, a hydroxymethyl group, or an alkyloxymethyl group. ^Rc11 and ^Rc12 each independently represent an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group. i and j each independently represent 0 or an integer of 1 to 4.)

^Z1 and ^Z2 each independently represent a halomethyl group, a hydroxyalkyl group, or an alkyloxymethyl group. Examples of the halomethyl group include a chloromethyl group. Examples of the alkyloxymethyl group include a methoxymethyl group and an ethoxymethyl group. Examples of the hydroxyalkyl group include a hydroxymethyl group and a 1-hydroxyethyl group. Among these, from the viewpoint of obtaining the effects of the present invention remarkably, a hydroxyalkyl group is preferable, and a hydroxymethyl group is more preferable.

R ^c11 and R ^c12 each independently represent an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group. Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, a vinyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, and a nonyl group. Examples of the halogen atom include a chlorine atom and a bromine atom. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the aralkyl group include a phenylmethyl group, a phenylethyl group, a naphthylmethyl group, and a naphthylethyl group.

Each of i and j independently represents 0 or an integer from 1 to 4, with 0 or 1 being preferred and 0 being more preferred.

As the aromatic polycarboxylic acid or its acid halide, an aromatic compound that can form an ester bond by reacting with a phenolic hydroxyl group in the reactant of a compound containing a phenol skeleton and a compound containing a biphenyl skeleton having a methylene chain can be used. Specific examples of aromatic polycarboxylic acids or their acid halides include benzene dicarboxylic acids such as isophthalic acid and terephthalic acid, benzene tricarboxylic acids such as trimellitic acid, naphthalene dicarboxylic acids such as naphthalene-1,4-dicarboxylic acid, naphthalene-2,3-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, and naphthalene-2,7-dicarboxylic acid, acid halides thereof, and compounds in which the aliphatic hydrocarbon group, alkoxy group, halogen atom, or the like is substituted on the aromatic nucleus of these compounds. Examples of acid halides include acid chlorides, acid bromides, acid fluorides, and acid iodides. These may be used alone or in combination of two or more types. Among these, from the viewpoint of obtaining the remarkable effects of the present invention, benzenedicarboxylic acids such as isophthalic acid and terephthalic acid or acid halides thereof are preferred, and isophthalic acid is more preferred.

（式（Ｃ－１）中、Ｒ^１１、Ｒ^１３、及びＲ^１４は、それぞれ独立に脂肪族炭化水素基、アルコキシ基、ハロゲン原子、アリール基、又はアラルキル基を表し、Ｒ^１２は、芳香族ポリカルボン酸又はその酸ハロゲン化物に由来する基を表す。ｍ１、ｍ２、及びｍ３は、それぞれ独立に０又は１～４の整数を表す。） The component (C) preferably has a structure represented by the following formula (C-1).

(In formula (C-1), R ¹¹ , R ¹³ , and R ¹⁴ each independently represent an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group; R ¹² represents a group derived from an aromatic polycarboxylic acid or an acid halide thereof; m1, m2, and m3 each independently represent 0 or an integer of 1 to 4.)

R ¹¹ , R ¹³ and R ¹⁴ each independently represent an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group or an aralkyl group. Examples of the aliphatic hydrocarbon group include a methyl group, an ethyl group, a vinyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclohexyl group, a heptyl group, an octyl group, and a nonyl group. Examples of the halogen atom include a chlorine atom and a bromine atom. Examples of the aryl group include a phenyl group and a naphthyl group. Examples of the aralkyl group include a phenylmethyl group, a phenylethyl group, a naphthylmethyl group, and a naphthylethyl group.

R ¹² represents a group derived from an aromatic polycarboxylic acid or an acid halide thereof, and is preferably a group derived from an aromatic polycarboxylic acid.

m1, m2, and m3 each independently represent 0 or an integer from 1 to 4, with 0 or 1 being preferred and 0 being more preferred.

As described above, component (C) can be a compound obtained by reacting a compound containing a phenol skeleton with a compound containing a biphenyl skeleton having a methylene chain to obtain a reaction product, and then reacting the reaction product with an aromatic polycarboxylic acid or an acid halide thereof.

The reaction of a compound containing a phenol skeleton and a compound containing a biphenyl skeleton having a methylene chain can be carried out, for example, by a method of heating and stirring under acid catalyst conditions at a temperature of about 80 to 180°C. The reaction may be carried out in an organic solvent as necessary. After the reaction is completed, an excess amount of the compound containing a phenol skeleton may be distilled off as necessary, or a mixture of the unreacted compound containing a phenol skeleton and the reactants may be used as is in the next reaction.

Examples of acid catalysts include paratoluenesulfonic acid, dimethyl sulfate, diethyl sulfate, sulfuric acid, hydrochloric acid, and oxalic acid. The acid catalysts may be used alone or in combination of two or more.

Examples of organic solvents include ketone solvents such as acetone, methyl ethyl ketone, and cyclohexanone; acetate ester solvents such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitol solvents such as cellosolve and butyl carbitol; aromatic hydrocarbon solvents such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. One type of organic solvent may be used alone, or two or more types may be used in combination.

The reaction between the reactant and an aromatic polycarboxylic acid or its acid halide can be carried out, for example, by heating and stirring in the presence of an alkali catalyst at a temperature of about 40 to 65°C. The reaction may be carried out in an organic solvent as necessary. After completion of the reaction, the reaction product may be purified as necessary by washing with water or reprecipitation.

Examples of the alkaline catalyst include sodium hydroxide, potassium hydroxide, triethylamine, and pyridine. The alkaline catalyst may be used alone or in combination of two or more types. The alkaline catalyst may be used as an aqueous solution of about 3 to 30%. The organic solvent may be any of the organic solvents listed above.

The reaction between the reactant and an aromatic polycarboxylic acid or its acid halide may be carried out in the presence of a polymerization catalyst such as tetrabutylammonium bromide, if necessary.

Component (C) may be a mixture containing an ester compound of a compound containing a phenol skeleton and an aromatic polycarboxylic acid or its acid halide, in addition to a compound obtained by reacting a compound containing a phenol skeleton and a compound containing a biphenyl skeleton having a methylene chain to obtain a reaction product, and then reacting the reaction product with an aromatic polycarboxylic acid or its acid halide. The ester compound can be produced as one component of component (C) by, for example, adjusting the reaction ratio of the compound containing a phenol skeleton, the compound containing a biphenyl skeleton having a methylene chain, and the aromatic polycarboxylic acid or its acid halide.

The weight average molecular weight (Mw) of component (C) is preferably 600 to 5,000, more preferably 800 to 3,000, from the viewpoint of obtaining a significant effect of the present invention. The number average molecular weight of the resin can be measured as a polystyrene-equivalent value by gel permeation chromatography (GPC).

The softening point of component (C) is preferably 100 to 180°C, more preferably 120 to 170°C, from the viewpoint of obtaining a significant effect of the present invention. The softening point is a value measured based on JIS K7234.

From the viewpoint of obtaining a significant effect of the present invention, the functional group equivalent of component (C) is preferably 210 to 360 g/eq., and more preferably 220 to 300 g/eq. The functional group refers to the ester bond site and the phenolic hydroxyl group in component (C). The functional group equivalent is a value calculated from the amount of the reaction raw material charged.

From the viewpoint of obtaining a cured product with a low dielectric tangent, the active ester group equivalent of component (C) is preferably 200 g/eq. or more, more preferably 210 g/eq. or more, even more preferably 220 g/eq. or more, and is preferably 400 g/eq. or less, more preferably 360 g/eq. or less, even more preferably 300 g/eq. or less. The active ester group refers to the ester bond site in component (C). The active ester group equivalent is a value calculated from the amount of the reaction raw material charged.

The ratio of the amount of the (A) component to the (C) component is the ratio of [total number of active ester groups in the (C) component]/[total number of epoxy groups in the (A) component], and is preferably 0.01 or more, more preferably 0.3 or more, and even more preferably 0.5 or more, and is preferably 5 or less, more preferably 3 or less, and even more preferably 2 or less. Here, the "number of epoxy groups in the (A) component" refers to the total value obtained by dividing the mass of the non-volatile components of the (A) component present in the resin composition by the epoxy equivalent. In addition, the "number of active ester groups in the (C) component" refers to the total value obtained by dividing the mass of the non-volatile components of the (C) component present in the resin composition by the active ester group equivalent. By setting the ratio of the (A) component to the (C) component within this range, it is possible to obtain the effects of the present invention significantly.

From the viewpoint of obtaining a cured product with improved peel strength, copper foil adhesion, and elongation at break, the content of component (C) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, assuming that the non-volatile components in the resin composition are 100% by mass. The upper limit is preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 10% by mass or less.

<(D) Thermosetting resin>
In addition to the above-mentioned components, the resin composition may contain a thermosetting resin (D) as an optional component. By including the component (D) in the resin composition, the dielectric properties and peel strength are low. The component (D) does not include components (A) to (C) and component (E). The component (D) may be used alone. Alternatively, two or more of them may be used.

Component (D) preferably contains a compound having a radically polymerizable unsaturated group in the molecule (hereinafter referred to as "radical polymerizable compound"). The radically polymerizable unsaturated group represents a group containing an unsaturated bond exhibiting radical polymerizability. Examples of this radically polymerizable unsaturated group include a group containing an ethylenic double bond. Component (D) containing such a radically polymerizable unsaturated group can cause radical polymerization by heat or active energy rays, and cure the resin composition.

Examples of radically polymerizable unsaturated groups include maleimide groups, vinyl groups, vinylphenyl groups, acryloyl groups, methacryloyl groups, fumaroyl groups, maleoyl groups, benzocyclobutene groups, and allyl groups. Among these, the maleimide group is preferred as component (D) from the viewpoint of obtaining the effects of the present invention more significantly. The number of radically polymerizable unsaturated groups contained in component (D) is usually 1 or more, and preferably 2 or more. When component (D) contains two or more radically polymerizable unsaturated groups, the two or more radically polymerizable unsaturated groups may be the same or different.

The (D) component is preferably at least one selected from maleimide resin, styryl resin, (meth)acrylic resin, and allyl resin, and more preferably at least one selected from maleimide resin, (meth)acrylic resin, and styryl resin.

It is more preferable that component (D) contains a compound having two or more radically polymerizable unsaturated groups in the molecule. There is no particular upper limit, but it can be 10 or less, for example.

(Maleimide resin)
Maleimide resins include:
(D-1) a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to a nitrogen atom of a maleimide group,
(D-2-1) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of a maleimide group, and (D-2-2) a maleimide compound having an aromatic ring directly bonded to a nitrogen atom of a maleimide group and including a trimethylindane skeleton,
It is preferable that the compound is one or more selected from the following:

The term "directly" means that in the case of component (D-1), there is no other group between the nitrogen atom of the maleimide group and the aliphatic group having 5 or more carbon atoms, and in the case of components (D-2-1) and (D-2-2), there is no other group between the nitrogen atom of the maleimide group and the aromatic ring. Note that components (D-2-1) and (D-2-2) are sometimes collectively referred to as component (D-2).

Component (D-1) is a maleimide compound containing an aliphatic group having 5 or more carbon atoms directly bonded to the nitrogen atom of the maleimide group. Component (D-1) can be obtained, for example, by imidization reaction of a component containing an aliphatic amine compound (such as a diamine compound having a dimer acid skeleton), maleic anhydride, and, if necessary, tetracarboxylic dianhydride.

Examples of aliphatic groups having 5 or more carbon atoms include alkyl groups, alkylene groups, and alkenylene groups.

The number of carbon atoms of an alkyl group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkyl group may be linear, branched, or cyclic, and linear is preferred. Examples of such alkyl groups include pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. An alkyl group having 5 or more carbon atoms may be present as a substituent of an alkylene group having 5 or more carbon atoms.

The number of carbon atoms in an alkylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkylene group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic alkylene group includes a case in which the alkylene group is composed only of a cyclic alkylene group, and a case in which the alkylene group contains both a linear alkylene group and a cyclic alkylene group. Examples of such alkylene groups include a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tridecylene group, a heptadecylene group, a hexatriacontylene group, a group having an octylene-cyclohexylene structure, a group having an octylene-cyclohexylene-octylene structure, and a group having a propylene-cyclohexylene-octylene structure.

The number of carbon atoms in an alkenylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkenylene group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic alkenylene group includes cases where the alkenylene group is composed only of a cyclic alkenylene group and cases where the alkenylene group contains both a linear alkenylene group and a cyclic alkenylene group. Examples of such alkenylene groups include pentynylene, hexynylene, heptylenylene, octynylene, nonynylene, decynylene, undecynylene, dodecynylene, tridecynylene, heptadecynylene, hexatriacontinylene, groups having an octynylene-cyclohexynylene structure, groups having an octynylene-cyclohexynylene-octynylene structure, and groups having a propynylene-cyclohexynylene-octynylene structure.

一般式（Ｄ－１－１）中、Ｍは置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基を表し、Ｌは単結合又は２価の連結基を表す。 The component (D-1) is preferably a compound represented by the following formula (D-1-1).

In formula (D-1-1), M represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, and L represents a single bond or a divalent linking group.

M represents a divalent aliphatic group having 5 or more carbon atoms, which may have a substituent. The number of carbon atoms in the divalent aliphatic group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This aliphatic group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic aliphatic group includes a case in which the group is composed only of a cyclic aliphatic group, and a case in which the group contains both a linear aliphatic group and a cyclic aliphatic group. Examples of the divalent aliphatic group include an alkylene group, an alkenylene group, and the like. The alkylene group and the alkenylene group are as described above.

Examples of the substituent of M include a halogen atom, -OH, -O-C _1-10 alkyl group, -N(C _1-10 alkyl group) ₂ , C _1-10 alkyl group, C _2-30 alkenyl group, C _2-30 alkynyl group, C _6-10 aryl group, -NH ₂ , -CN, -C(O)O-C _1-10 alkyl group, -COOH, -C(O)H, -NO _2, and the like. Here, the term "C _x-y " (x and y are positive integers, and x<y) indicates that the number of carbon atoms in the organic group described immediately after this term is x to y. For example, the expression "C _1-10 alkyl group" indicates an alkyl group having 1 to 10 carbon atoms. These substituents may be bonded to each other to form a ring, and the ring structure also includes a spiro ring and a fused ring. The substituent is preferably an alkyl group having 5 or more carbon atoms.

L represents a single bond or a divalent linking group. Examples of the divalent linking group include an alkylene group, an alkenylene group, an alkynylene group, an arylene group, -C(=O)-, -C(=O)-O-, -NR ⁰ - (R ⁰ is a hydrogen atom, an alkyl group having 1 to 3 carbon atoms), an oxygen atom, a sulfur atom, C(=O)NR ⁰ -, a divalent group derived from phthalimide, a divalent group derived from pyromellitic diimide, and a group consisting of a combination of two or more of these divalent groups. The alkylene group, the alkenylene group, the alkynylene group, the arylene group, the divalent group derived from phthalimide, the divalent group derived from pyromellitic diimide, and a group consisting of a combination of two or more of these divalent groups may have an alkyl group having 5 or more carbon atoms as a substituent. The divalent group derived from phthalimide represents a divalent group derived from phthalimide, and specifically, is a group represented by the general formula (D-1-2). The divalent group derived from pyromellitic diimide refers to a divalent group derived from pyromellitic diimide, specifically, a group represented by general formula (D-1-3), in which "*" represents a bond.

The alkylene group as the divalent linking group in L is preferably an alkylene group having 1 to 50 carbon atoms, more preferably an alkylene group having 1 to 45 carbon atoms, and particularly preferably an alkylene group having 1 to 40 carbon atoms. This alkylene group may be linear, branched, or cyclic. Examples of such alkylene groups include methylethylene, cyclohexylene, pentylene, hexylene, heptylene, octylene, nonylene, decylene, undecylene, dodecylene, tridecylene, heptadecylene, hexatriacontylene, groups having an octylene-cyclohexylene structure, groups having an octylene-cyclohexylene-octylene structure, and groups having a propylene-cyclohexylene-octylene structure.

The alkenylene group as the divalent linking group in L is preferably an alkenylene group having 2 to 50 carbon atoms, more preferably an alkenylene group having 2 to 45 carbon atoms, and particularly preferably an alkenylene group having 2 to 40 carbon atoms. This alkenylene group may be linear, branched, or cyclic. Examples of such alkenylene groups include a methylethylenylene group, a cyclohexenylene group, a pentenylene group, a hexenylene group, a heptenylene group, and an octenylene group.

The alkynylene group as the divalent linking group in L is preferably an alkynylene group having 2 to 50 carbon atoms, more preferably an alkynylene group having 2 to 45 carbon atoms, and particularly preferably an alkynylene group having 2 to 40 carbon atoms. This alkynylene group may be linear, branched, or cyclic. Examples of such alkynylene groups include a methylethynylene group, a cyclohexynylene group, a pentynylene group, a hexynylene group, a heptynylene group, and an octynylene group.

The arylene group as the divalent linking group in L is preferably an arylene group having 6 to 24 carbon atoms, more preferably an arylene group having 6 to 18 carbon atoms, even more preferably an arylene group having 6 to 14 carbon atoms, and even more preferably an arylene group having 6 to 10 carbon atoms. Examples of the arylene group include a phenylene group, a naphthylene group, and an anthracenylene group.

The divalent linking groups in L, that is, alkylene groups, alkenylene groups, alkynylene groups, and arylene groups, may have a substituent. The substituent is the same as the substituent of M in general formula (B2-1-1), and is preferably an alkyl group having 5 or more carbon atoms.

Examples of groups consisting of a combination of two or more divalent groups in L include a divalent group consisting of a combination of an alkylene group, a divalent group derived from phthalimide, and an oxygen atom; a divalent group consisting of a combination of a divalent group derived from phthalimide, an oxygen atom, an arylene group, and an alkylene group; a divalent group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide; and the like. A group consisting of a combination of two or more divalent groups may form a ring such as a condensed ring by the combination of the respective groups. In addition, a group consisting of a combination of two or more divalent groups may have a repeating unit number of 1 to 10.

Among these, L in general formula (D-1-1) is preferably an oxygen atom, an arylene group having 6 to 24 carbon atoms which may have a substituent, an alkylene group having 1 to 50 carbon atoms which may have a substituent, an alkyl group having 5 or more carbon atoms, a divalent group derived from phthalimide, a divalent group derived from pyromellitic diimide, or a divalent group consisting of a combination of two or more of these groups. Among them, as L, an alkylene group; a divalent group having a structure of an alkylene group-phthalimide-derived divalent group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of an alkylene group-phthalimide-derived divalent group-oxygen atom-arylene group-alkylene group-arylene group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of an alkylene-pyromellitic diimide-derived divalent group; a divalent group having a structure of an alkynylene group-phthalimide-derived divalent group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of an alkynylene group-phthalimide-derived divalent group-oxygen atom-arylene group-alkynylene group-arylene group-oxygen atom-phthalimide-derived divalent group; a divalent group having a structure of a divalent group having ...

一般式（Ｄ－１－４）中、Ｍ^１はそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基を表し、Ｚはそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基又は置換基を有していてもよい芳香環を有する２価の基を表す。ｔは１～１０の整数を表す。 The maleimide resin represented by the general formula (D-1-1) is preferably a maleimide resin represented by the general formula (D-1-4).

In formula (D-1-4), M1 ^'s each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, Z's each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent or a divalent group having an aromatic ring which may have a substituent, and t represents an integer from 1 to 10.

Each ^M1 independently represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. ^M1 is the same as M in formula (D-1-1).

Each Z independently represents a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, or a divalent group having an aromatic ring which may have a substituent. Examples of the divalent aliphatic group in Z include an alkylene group and an alkenylene group. The divalent aliphatic group may be linear, branched, or cyclic, and among these, a cyclic divalent aliphatic group having 5 or more carbon atoms which may have a substituent is preferred.

The number of carbon atoms in the alkylene group is preferably 6 or more, more preferably 8 or more, and preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. Examples of such alkylene groups include groups having an octylene-cyclohexylene structure, groups having an octylene-cyclohexylene-octylene structure, and groups having a propylene-cyclohexylene-octylene structure.

The number of carbon atoms in an alkenylene group having 5 or more carbon atoms is preferably 6 or more, more preferably 8 or more, preferably 50 or less, more preferably 45 or less, and even more preferably 40 or less. This alkenylene group may be linear, branched, or cyclic, and linear is preferred. Here, the concept of a cyclic alkenylene group includes cases where the alkenylene group is composed only of a cyclic alkenylene group and cases where the alkenylene group contains both a linear alkenylene group and a cyclic alkenylene group. Examples of such alkenylene groups include pentynylene, hexynylene, heptylenylene, octynylene, nonynylene, decynylene, undecynylene, dodecynylene, tridecynylene, heptadecynylene, hexatriacontinylene, groups having an octynylene-cyclohexynylene structure, groups having an octynylene-cyclohexynylene-octynylene structure, and groups having a propynylene-cyclohexynylene-octynylene structure.

Examples of the aromatic ring in the divalent group having an aromatic ring represented by Z include a benzene ring, a naphthalene ring, an anthracene ring, a phthalimide ring, a pyromellitic diimide ring, and an aromatic heterocycle, and the like are mentioned, with a benzene ring, a phthalimide ring, and a pyromellitic diimide ring being preferred. That is, examples of the divalent group having an aromatic ring include a divalent group having a benzene ring which may have a substituent, a divalent group having a phthalimide ring which may have a substituent, and a divalent group having a pyromellitic diimide ring which may have a substituent. Examples of the divalent group having an aromatic ring include a group consisting of a combination of a divalent group derived from phthalimide and an oxygen atom; a group consisting of a combination of a divalent group derived from phthalimide, an oxygen atom, an arylene group, and an alkylene group; a group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide; a divalent group derived from pyromellitic diimide; a group consisting of a combination of a divalent group derived from phthalimide and an alkylene group; and the like. The above arylene group is the same as the arylene group in the divalent linking group represented by L in general formula (D-1-1).

The alkylene group and the divalent group having an aromatic ring represented by Z may have a substituent. The substituent is the same as the substituent that may be possessed by M in general formula (D-1-1).

Specific examples of the group represented by Z include the following groups: In the formula, "*" represents a bond.

一般式（Ｄ－１－５）中、Ｍ^２及びＭ^３はそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の２価の脂肪族基を表し、Ｒ^４０はそれぞれ独立に、酸素原子、アリーレン基、アルキレン基、又はこれらの基の２以上の組み合わせからなる２価の基を表す。ｔ１は１～１０の整数を表す。
一般式（Ｄ－１－６）中、Ｍ^４、Ｍ^６及びＭ^７はそれぞれ独立に置換基を有していてもよい炭素原子数が５以上の脂肪族基を表し、Ｍ^５はそれぞれ独立に置換基を有していてもよい芳香環を有する２価の基を表し、Ｒ^４１及びＲ^４２はそれぞれ独立に炭素原子数が５以上のアルキル基を表す。ｔ２は０～１０の整数を表し、ｕ１及びｕ２はそれぞれ独立に０～４の整数を表す。 The compound represented by general formula (D-1-1) is preferably any one of a compound represented by general formula (D-1-5) and a compound represented by general formula (D-1-6).

In formula (D-1-5), ^M2 and ^M3 each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent, ^R40 each independently represent an oxygen atom, an arylene group, an alkylene group, or a divalent group consisting of a combination of two or more of these groups, and t1 represents an integer from 1 to 10.
In formula (D-1-6), ^M4 , ^M6 , and ^M7 each independently represent an aliphatic group having 5 or more carbon atoms which may have a substituent, ^M5 each independently represent a divalent group having an aromatic ring which may have a substituent, ^R41 and ^R each independently represent an alkyl group having 5 or more carbon atoms, t2 represents an integer of 0 to 10, and u1 and u2 each independently represent an integer of 0 to 4.

^M2 and ^M3 each independently represent a divalent aliphatic group having 5 or more carbon atoms which may have a substituent. ^M2 and ^M3 are the same as the divalent aliphatic group having 5 or more carbon atoms represented by M in general formula (D-1-1), and are preferably a hexatriacontinylene group or a hexatriacontylene group.

Each R ⁴⁰ independently represents an oxygen atom, an arylene group, an alkylene group, or a group consisting of a combination of two or more of these divalent groups. The arylene group and the alkylene group are the same as the arylene group and the alkylene group in the divalent linking group represented by L in the general formula (D-1-1). R ⁴⁰ is preferably a group consisting of a combination of two or more of the divalent groups or an oxygen atom.

Examples of the group consisting of a combination of two or more divalent groups in ^R40 include a combination of an oxygen atom, an arylene group, and an alkylene group. Specific examples of the group consisting of a combination of two or more divalent groups include the following groups. In the formula, "*" represents a bond.

^M4 , ^M6 , and ^M7 each independently represent an aliphatic group having 5 or more carbon atoms which may have a substituent. ^M4 , ^M6 , and ^M7 are the same as the aliphatic group having 5 or more carbon atoms which may have a substituent represented by M in general formula (D-1-1), and are preferably a hexylene group, a heptylene group, an octylene group, a nonylene group, or a decylene group, and more preferably an octylene group.

M ⁵ each independently represents a divalent group having an aromatic ring which may have a substituent. M ⁵ is the same as the divalent group having an aromatic ring which may have a substituent represented by Z in the general formula (D-1-4), and is preferably a group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide; a group consisting of a combination of a divalent group derived from phthalimide and an alkylene group, and more preferably a group consisting of a combination of an alkylene group and a divalent group derived from pyromellitic diimide. The arylene group and alkylene group are the same as the arylene group and alkylene group in the divalent linking group represented by L in the general formula (D-1-1).

Specific examples of the group represented by ^M5 include the following groups: In the formula, "*" represents a bond.

R ⁴¹ and R ⁴² each independently represent an alkyl group having 5 or more carbon atoms. R ⁴¹ and R ⁴² are the same as the alkyl group having 5 or more carbon atoms described above, and are preferably a hexyl group, a heptyl group, an octyl group, a nonyl group, or a decyl group, and more preferably a hexyl group or an octyl group.

u1 and u2 each independently represent an integer from 1 to 15, preferably an integer from 1 to 10.

Specific examples of the component (D-1) include the following compounds (Di) to (D-iii), but are not limited to these specific examples. In the formula, v represents an integer of 1 to 10.

Specific examples of the (D-1) component include "BMI1500" (compound of formula (D-i)), "BMI1700" (compound of formula (D-ii)), and "BMI689" manufactured by Designor Molecules, Inc., and "SLK-6895" (compound of formula (D-iii)) manufactured by Shin-Etsu Chemical Co., Ltd., etc.

The weight average molecular weight (Mw) of component (D-1) is preferably 150 to 5,000, and more preferably 300 to 2,500.

From the viewpoint of significantly achieving the desired effects of the present invention, the maleimide group equivalent of the (D-1) component is preferably 50 g/eq. to 2000 g/eq., more preferably 100 g/eq. to 1000 g/eq., and even more preferably 150 g/eq. to 500 g/eq. The maleimide group equivalent is the mass of the (D-1) component containing one equivalent of maleimide groups.

The (D-2-1) component is a maleimide compound having an aromatic ring directly bonded to the nitrogen atom of the maleimide group. The (D-2-1) component can be obtained, for example, by subjecting a component containing an aromatic amine compound (such as an aromatic diamine compound) and maleic anhydride to an imidization reaction.

The aromatic ring may be a carbocyclic or heterocyclic ring. Examples of the aromatic ring include monocyclic aromatic rings such as a benzene ring, a furan ring, a thiophene ring, a pyrrole ring, a pyrazole ring, an oxazole ring, an isoxazole ring, a thiazole ring, an imidazole ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, and a pyrazine ring; condensed rings in which two or more monocyclic aromatic rings are condensed, such as a naphthalene ring, an anthracene ring, a benzofuran ring, an isobenzofuran ring, an indole ring, an isoindole ring, a benzothiophene ring, a benzimidazole ring, an indazole ring, a benzoxazole ring, a benzisoxazole ring, a benzothiazole ring, a quinoline ring, an isoquinoline ring, a quinoxaline ring, an acridine ring, a quinazoline ring, a cinnoline ring, and a phthalazine ring; and condensed rings in which one or more monocyclic aromatic rings, such as an indane ring, a fluorene ring, and a tetralin ring, are condensed to one or more monocyclic non-aromatic rings. Among these, the aromatic ring is preferably a monocyclic aromatic ring, and more preferably a benzene ring.

The component (D-2-1) is preferably a compound represented by the following formula (D-2-1).

In the formula, R ^c 's each independently represent a substituent; X ^c 's each independently represent a single bond, an alkylene group, an alkenylene group, -O-, -CO-, -S-, -SO-, -SO ₂ -, -CONH-, -NHCO-, -COO-, or -OCO- (preferably a single bond or an alkylene group); Z ^c 's each independently represent a non-aromatic ring which may have a substituent, or an aromatic ring which may have a substituent (preferably an aromatic ring which may have a substituent, particularly preferably an aromatic ring which may have a substituent); s represents an integer of 1 or more (preferably an integer of 1 to 100, more preferably an integer of 1 to 50, and even more preferably an integer of 1 to 20); t1's each independently represent 0 or an integer of 1 or more; and u's each independently represent an integer of 0 to 2 (preferably 0).] are particularly preferably maleimide compounds represented by the formulae (D-2-2) to (D-2-5):

式中、Ｒ^ｃ１、Ｒ^ｃ２及びＲ^ｃ３は、それぞれ独立して、アルキル基を示し；Ｘ^ｃ１及びＸ^ｃ２は、それぞれ独立して、単結合又はアルキレン基を示し；ｓは、１以上の整数（好ましくは１～１００の整数、より好ましくは１～５０の整数、さらに好ましくは１～２０の整数）を示し；ｔ’は、１～５の整数を示し；ｖ１、ｖ２及びｖ３は、それぞれ独立して、０～２の整数（好ましくは０）を示す。なお、ｓ単位、ｔ単位、ｔ’単位、ｖ単位、ｖ１単位、ｖ２単位及びｖ３単位は、それぞれ、単位毎に同一であってもよいし、異なっていてもよい。

In the formula, R ^c1 , R ^c2 and R ^c3 each independently represent an alkyl group; X ^c1 and X ^c2 each independently represent a single bond or an alkylene group; s represents an integer of 1 or more (preferably an integer of 1 to 100, more preferably an integer of 1 to 50, and even more preferably an integer of 1 to 20); t' represents an integer of 1 to 5; and v1, v2 and v3 each independently represent an integer of 0 to 2 (preferably 0). Note that the s unit, t unit, t' unit, v unit, v1 unit, v2 unit and v3 unit may be the same or different for each unit.

式中、Ｒ^３１及びＲ^３６はマレイミド基を表し、Ｒ^３２、Ｒ^３３、Ｒ^３４及びＲ^３５は、それぞれ独立に水素原子、アルキル基、又はアリール基を表し、Ｄはそれぞれ独立に２価の芳香族基を表す。ｍ１及びｍ２はそれぞれ独立に１～１０の整数を表し、ａは１～１００の整数を表す。 In another embodiment, the component (D-2-1) preferably has a structure represented by the following formula (D-2-6).

In the formula, R ³¹ and R ³⁶ represent a maleimide group, R ³² , R ³³ , R ³⁴ and R ³⁵ each independently represent a hydrogen atom, an alkyl group or an aryl group, and D each independently represents a divalent aromatic group. m1 and m2 each independently represent an integer of 1 to 10, and a represents an integer of 1 to 100.

In formula (D-2-6), R ³² , R ³³ , R ³⁴ and R ³⁵ each independently represent a hydrogen atom, an alkyl group or an aryl group, and preferably a hydrogen atom.

As the alkyl group, an alkyl group having 1 to 10 carbon atoms is preferable, an alkyl group having 1 to 6 carbon atoms is more preferable, and an alkyl group having 1 to 3 carbon atoms is even more preferable. The alkyl group may be linear, branched, or cyclic. Examples of such alkyl groups include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and an isopropyl group.

The aryl group is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms. The aryl group may be a single ring or a condensed ring. Examples of such aryl groups include a phenyl group, a naphthyl group, and an anthracenyl group.

The alkyl group and the aryl group may have a substituent. The substituent is not particularly limited, and examples thereof include a halogen atom, -OH, -O-C _1-6 alkyl group, -N(C _1-10 alkyl group) ₂ , C _1-10 alkyl group, C _6-10 aryl group, -NH ₂ , -CN, -C(O)O-C _1-10 alkyl group, -COOH, -C(O)H, and -NO _2. Here, the term "C _p-q " (p and q are positive integers, and p<q is satisfied) indicates that the number of carbon atoms in the organic group described immediately after this term is p to q. For example, the expression "C _1-10 alkyl group" indicates an alkyl group having 1 to 10 carbon atoms. These substituents may be bonded to each other to form a ring, and the ring structure also includes a spiro ring and a fused ring.

The above-mentioned substituents may further have a substituent (hereinafter, sometimes referred to as a "secondary substituent"). Unless otherwise specified, the secondary substituent may be the same as the above-mentioned substituent.

D in formula (D-2-6) represents a divalent aromatic group. Examples of the divalent aromatic group include a phenylene group, a naphthylene group, an anthracenylene group, an aralkyl group, a biphenylene group, and a biphenylaralkyl group. Among them, a biphenylene group and a biphenylaralkyl group are preferred, and a biphenylene group is more preferred. The divalent aromatic group may have a substituent. The substituent is the same as the substituent that the alkyl group represented by R ³² in formula (D-2-6) may have.

m1 and m2 each independently represent an integer from 1 to 10, preferably from 1 to 6, more preferably from 1 to 3, even more preferably from 1 to 2, and even more preferably 1.

a represents an integer from 1 to 100, preferably from 1 to 50, more preferably from 1 to 20, and even more preferably from 1 to 5.

式中、Ｒ^３７及びＲ^３８はマレイミド基を表す。ａ１は１～１００の整数を表す。 The component (D-2-1) is preferably a resin represented by formula (D-2-7).

In the formula, R ³⁷ and R ³⁸ each represent a maleimide group, and a1 represents an integer of 1 to 100.

a1 is the same as a in formula (D-2-6), and the preferred range is also the same.

Commercially available products of component (D-2-1) include, for example, "MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd.; "BMI-50P" manufactured by KI Kasei Co., Ltd.; "BMI-1000", "BMI-1000H", "BMI-1100", "BMI-1100H", "BMI-4000", and "BMI-5100" manufactured by Daiwa Kasei Kogyo Co., Ltd.; "BMI-4,4'-BPE", "BMI-70" manufactured by KI Kasei Co., Ltd., and "BMI-80" manufactured by KI Kasei Co., Ltd.

The weight average molecular weight (Mw) of the (D-2-1) component is preferably 150 to 5,000, and more preferably 300 to 2,500.

The functional group equivalent of the maleimide group in component (D-2-1) is preferably 50 g/eq. to 2000 g/eq., more preferably 100 g/eq. to 1000 g/eq., even more preferably 150 g/eq. to 500 g/eq., and particularly preferably 200 g/eq. to 300 g/eq.

The (D-2-2) component is a maleimide compound that has an aromatic ring directly bonded to the nitrogen atom of the maleimide group and contains a trimethylindane skeleton. The trimethylindane skeleton is the skeleton shown in the following formula (D-3-1).

The benzene ring contained in the trimethylindane skeleton may have a substituent bonded thereto, for example, an alkyl group, an alkyloxy group, an alkylthio group, an aryl group, an aryloxy group, an arylthio group, a cycloalkyl group, a halogen atom, a hydroxyl group, and a mercapto group.
The number of carbon atoms in the alkyl group is preferably 1 to 10. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a t-butyl group.
The number of carbon atoms in the alkyloxy group is preferably 1 to 10. Examples of the alkyloxy group include a methoxy group, an ethoxy group, a propoxy group, and a butoxy group.
The number of carbon atoms in the alkylthio group is preferably 1 to 10. Examples of the alkylthio group include a methylthio group, an ethylthio group, a propylthio group, and a butylthio group.
The number of carbon atoms in the aryl group is preferably 6 to 10. Examples of the aryl group include a phenyl group and a naphthyl group.
The number of carbon atoms in the aryloxy group is preferably 6 to 10. Examples of the aryloxy group include a phenyloxy group and a naphthyloxy group.
The number of carbon atoms in the arylthio group is preferably 6 to 10. Examples of the arylthio group include a phenylthio group and a naphthylthio group.
The number of carbon atoms in the cycloalkyl group is preferably 3 to 10. Examples of the cycloalkyl group include a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and an iodine atom.

Among the above-mentioned substituents, the hydrogen atoms of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group may be substituted with halogen atoms.

The number of substituents bonded to one benzene ring contained in the trimethylindane skeleton may be 1 or 2 or more. The number of substituents bonded to a benzene ring contained in the trimethylindane skeleton is usually 0 to 3. When the number of substituents is 2 or more, the 2 or more substituents may be the same or different. In particular, it is preferable that no substituents are bonded to the benzene ring contained in the trimethylindane skeleton.

The number of trimethylindane structures contained in one molecule of component (D-2-2) may be 1 or 2 or more. The upper limit may be, for example, 10 or less, 8 or less, 7 or less, or 6 or less.

The (D-2-2) component further contains an aromatic ring skeleton in addition to the above-mentioned trimethylindane skeleton. The number of ring-constituting carbon atoms of the aromatic ring skeleton is preferably 6 to 10. Examples of aromatic ring skeletons include a benzene ring skeleton and a naphthalene ring skeleton. The number of the aromatic ring skeletons contained in one molecule of the (D-2-2) component is preferably 1 or more, more preferably 2 or more, and preferably 6 or less, more preferably 4 or less, and particularly preferably 3 or less. When the (D-2-2) component contains two or more aromatic ring skeletons in addition to the trimethylindane skeleton, the aromatic ring skeletons may be the same or different.

The aromatic ring contained in the aromatic ring skeleton may have a substituent bonded thereto. Examples of the substituent include the substituents described above as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton, and a nitro group. The number of substituents bonded to one aromatic ring may be 1 or 2 or more. The number of substituents bonded to an aromatic ring is usually 0 to 4. When the number of substituents is 2 or more, the 2 or more substituents may be the same or different.

The (D-2-2) component preferably further contains a divalent aliphatic hydrocarbon group in addition to the above-mentioned trimethylindane skeleton. In particular, when the (D-2-2) component contains an aromatic ring skeleton other than the benzene ring contained in the trimethylindane skeleton, the (D-2-2) component preferably contains a divalent aliphatic hydrocarbon group. In this case, the divalent aliphatic hydrocarbon group preferably connects between the benzene ring and the aromatic ring skeleton contained in the trimethylindane skeleton. In addition, the divalent aliphatic hydrocarbon group preferably connects between the aromatic ring skeletons.

The number of carbon atoms in the divalent aliphatic hydrocarbon group is preferably 1 or more, and preferably 12 or less, more preferably 8 or less, and particularly preferably 5 or less. As the divalent aliphatic hydrocarbon group, an alkylene group as a saturated aliphatic hydrocarbon group is more preferable. Examples of the divalent aliphatic hydrocarbon group include linear alkylene groups such as methylene, ethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene groups; and branched alkylene groups such as ethylidene (-CH(CH ₃ )-), propylidene (-CH(CH ₂ CH ₃ )-), isopropylidene (-C(CH ₃ ) ₂ -), ethylmethylmethylene (-C(CH ₃ )(CH ₂ CH ₃ )-), and diethylmethylene (-C(CH ₂ CH ₃ ) ₂ -). When the component (D-2-2) contains two or more divalent aliphatic hydrocarbon groups in addition to the trimethylindane skeleton, those divalent aliphatic hydrocarbon groups may be the same or different.

The component (D-2-2) preferably contains a structure represented by the following formula (D-3-2): The entire component (D-2-2) may have the structure represented by formula (D-3-2), or a portion of the component (D-2-2) may have the structure represented by formula (D-3-2).

(In the formula, Ar ^a1 represents a divalent aromatic hydrocarbon group which may have a substituent; each R ^a1 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, 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 nitro group, a hydroxyl group, or a mercapto group; each R ^a2 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, 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; R ^a3 each independently represents a divalent aliphatic hydrocarbon group; n _a1 represents a positive integer; n _a2 each independently represents an integer of 0 to 4; n _a3 each independently represents an integer of 0 to 3. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of ^{R a1} may be substituted with a halogen atom. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ^a2 may be substituted with a halogen atom. When _{n a2} is 2 to 4, R ^a1 may be the same or different within the same ring. When n _a3 is 2 to 3, R ^a2 may be the same or different within the same ring.)

In formula (D-3-2), Ar ^a1 represents a divalent aromatic hydrocarbon group which may have a substituent. The number of carbon atoms in this divalent aromatic hydrocarbon group is preferably 6 or more, preferably 20 or less, more preferably 16 or less. Examples of the divalent aromatic hydrocarbon group include a phenylene group and a naphthylene group. Examples of the substituent that the divalent aromatic hydrocarbon group may have include 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, 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, and a mercapto group. The hydrogen atom of each substituent may be further substituted with a halogen atom. Specific examples of these substituents include the same examples as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton. When the divalent aromatic hydrocarbon group has a substituent, the number of the substituents is preferably 1 to 4. When the divalent aromatic hydrocarbon group has two or more substituents, the two or more substituents may be the same or different. Among them, Ar ^a1 is preferably a divalent aromatic hydrocarbon group having no substituent.

In formula (D-3-2), R ^a1 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, 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 nitro group, a hydroxyl group, or a mercapto group. The hydrogen atoms of the alkyl group, the alkyloxy group, the alkylthio group, the aryl group, the aryloxy group, the arylthio group, and the cycloalkyl group may be substituted with a halogen atom. Specific examples of these groups include the same examples as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton. Among them, R ^a1 is more preferably one or more groups selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms, and is particularly preferably an alkyl group having 1 to 4 carbon atoms.

In formula (D-3-2), R ^a2 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, 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. The hydrogen atoms of the alkyl group, the alkyloxy group, the alkylthio group, the aryl group, the aryloxy group, the arylthio group, and the cycloalkyl group may be substituted with a halogen atom. Specific examples of these groups include the same examples as the substituents that may be bonded to the benzene ring contained in the trimethylindane skeleton. Among them, R ^a2 is more preferably one or more groups selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group having 3 to 6 carbon atoms, and an aryl group having 6 to 10 carbon atoms.

In formula (D-3-2), each R ^a3 independently represents a divalent aliphatic hydrocarbon group. The preferred range of the divalent aliphatic hydrocarbon group is as described above.

In formula (D-3-2), n _a1 represents a positive integer. n _a1 is preferably 1 or more and is preferably 10 or less, and more preferably 8 or less.

In formula (D-3-2), n _a2 each independently represents an integer of 0 to 4. n _a2 is preferably 2 or 3, more preferably 2. Multiple n _a2 may be different, but are preferably the same. When n _a2 is 2 or more, multiple R ^a1 may be the same or different within the same ring.

In formula (D-3-2), n _a3 each independently represents an integer of 0 to 3. Multiple n _a3 may be different, but are preferably the same. n _a3 is preferably 0.

（式中、Ｒ^ｂ１は、それぞれ独立に、炭素原子数１～１０のアルキル基、炭素原子数１～１０のアルキルオキシ基、炭素原子数１～１０のアルキルチオ基、炭素原子数６～１０のアリール基、炭素原子数６～１０のアリールオキシ基、炭素原子数６～１０のアリールチオ基、炭素原子数３～１０のシクロアルキル基、ハロゲン原子、ニトロ基、水酸基、又は、メルカプト基を表し；Ｒ^ｂ２は、それぞれ独立に、炭素原子数１～１０のアルキル基、炭素原子数１～１０のアルキルオキシ基、炭素原子数１～１０のアルキルチオ基、炭素原子数６～１０のアリール基、炭素原子数６～１０のアリールオキシ基、炭素原子数６～１０のアリールチオ基、炭素原子数３～１０のシクロアルキル基、ハロゲン原子、水酸基、又は、メルカプト基を表し；ｎ_ｂ１は、正の整数を表し；ｎ_ｂ２は、それぞれ独立に、０～４の整数を表し；ｎ_ｂ３は、それぞれ独立に、０～３の整数を表す。Ｒ^ｂ１のアルキル基、アルキルオキシ基、アルキルチオ基、アリール基、アリールオキシ基、アリールチオ基、及びシクロアルキル基の水素原子は、ハロゲン原子で置換されていてもよい。Ｒ^ｂ２のアルキル基、アルキルオキシ基、アルキルチオ基、アリール基、アリールオキシ基、アリールチオ基、及びシクロアルキル基の水素原子は、ハロゲン原子で置換されていてもよい。ｎ_ｂ２が２～４の場合、Ｒ^ｂ１は、同一環内で同じであってもよく異なっていてもよい。ｎ_ｂ３が２～３の場合、Ｒ^ｂ２は、同一環内で同じであってもよく異なっていてもよい。） It is particularly preferable that the component (D-2-2) contains a structure represented by the following formula (D-3-3): The entire component (D-2-2) may have the structure represented by formula (D-3-3), or a portion of the component (D-2-2) may have the structure represented by formula (D-3-3).

(In the formula, R ^b1 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, 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 nitro group, a hydroxyl group, or a mercapto group; R ^b2 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, 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; n _b1 represents a positive integer; n _b2 each independently represents an integer of 0 to 4; _b3 each independently represents an integer of 0 to 3. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of ^{R b1} may be substituted with a halogen atom. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ^b2 may be substituted with a halogen atom. When n _b2 is 2 to 4, R ^b1 may be the same or different in the same ring. When n _b3 is 2 to 3, R ^b2 may be the same or different in the same ring.)

In formula (D-3-3), R ^b1 , R ^b2 , n _b1 , n _b2 and n _b3 are the same as R ^a1 , R ^a2 , n _a1 , n _a2 and n _a3 in formula (D-3-2), respectively.

式（Ｄ－３－４）において、Ｒ^ｃ１、Ｒ^ｃ２、ｎ_ｃ２及びｎ_ｃ３は、それぞれ、式（Ａ４）におけるＲ^ａ１、Ｒ^ａ２、ｎ_ａ２及びｎ_ａ３と同じである。また、式（Ｄ－３－４）において、ｎ_ｃ１は、繰り返し単位数であり、１～２０の整数を表す。さらに、式（Ｅ２－３－４）において、＊は、結合手を表す。例えば、（Ｄ－２－２）成分は、式（Ｄ－３－２）において、ｎ_ａ２が３以下であり、且つ、マレイミド基が結合するベンゼン環のマレイミド基に対するオルト位及びパラ位のうち、２つ以上に、Ｒ^ａ１が結合していない場合に、式（Ｄ－３－２）で表される構造に組み合わせて前記の式（Ｄ－３－４）で表される構造を含みうる。また、例えば、（Ｄ－２－２）成分は、式（Ｄ－３－３）において、ｎ_ｂ２が３以下であり、且つ、マレイミド基が結合するベンゼン環のマレイミド基に対するオルト位及びパラ位のうち、２つ以上に、Ｒ^ｂ１が結合していない場合に、式（Ｄ－３－３）で表される構造に組み合わせて前記の式（Ｄ－３－４）で表される構造を含みうる。 The component (D-2-2) may further contain a structure represented by the following formula (D-3-4).

In formula (D-3-4), R ^c1 , R ^c2 , n _c2 and n _c3 are the same as R ^a1 , R ^a2 , n _a2 and n _a3 in formula (A4), respectively. In formula (D-3-4), n _c1 is the number of repeating units and represents an integer of 1 to 20. In formula (E2-3-4), * represents a bond. For example, when n _a2 is 3 or less in formula (D-3-2) and R ^a1 is not bonded to two or more of the ortho-positions and para-positions relative to the maleimide group of the benzene ring to which the maleimide group is bonded, the (D-2-2) component may contain a structure represented by formula (D-3-4) in combination with the structure represented by formula (D-3-2). Furthermore, for example, when n _b2 is 3 or less in formula (D-3-3) and R b1 is not bonded to two or more of the ortho-positions and para-positions relative to the maleimide group of the benzene ring to which the ^maleimide group is bonded, the component (D-2-2) can contain a structure represented by formula (D-3-4) in combination with the structure represented by formula (D-3-3).

The (D-2-2) component may be used alone or in any combination of two or more types in any ratio.

The maleimide group equivalent of the (D-2-2) component is preferably 50 g/eq. or more, more preferably 100 g/eq. or more, particularly preferably 200 g/eq. or more, and is preferably 2000 g/eq. or less, more preferably 1000 g/eq. or less, particularly preferably 800 g/eq. or less. The maleimide group equivalent represents the mass of the maleimide compound per equivalent of maleimide group. When the maleimide group equivalent of the (D-2-2) component is within the above range, the effects of the present invention can be obtained significantly.

There are no particular limitations on the method for producing component (D-2-2). Component (D-2-2) can be produced, for example, by the method described in Japan Institute of Invention and Innovation's Technical Journal No. 2020-500211. According to the production method described in Japan Institute of Invention and Innovation's Technical Journal No. 2020-500211, it is possible to obtain a maleimide compound having a distribution in the number of repeating units of the trimethylindane skeleton. The maleimide compound obtained by this method contains a structure represented by the following formula (D-3-5). Therefore, component (D-2-2) may contain a maleimide compound containing a structure represented by formula (D-3-5).

(wherein, R ¹ 's each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, 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 nitro group, a hydroxyl group, or a mercapto group; R ² 's each independently represent an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, 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; n ₁ 's each independently represent an average number of repeating units of 0.95 to 10.0; n ₂ 's each independently represent an integer of 0 to 4; Each of n 2 and _{n 3} independently represents an integer of 0 to 3. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ¹ may be substituted with a halogen atom. The hydrogen atom of the alkyl group, alkyloxy group, alkylthio group, aryl group, aryloxy group, arylthio group, and cycloalkyl group of R ² may be substituted with a halogen atom. When n ₂ is 2 to 4, R ¹ may be the same or different in the same ring. When n ₃ is 2 to 3, R ² may be the same or different in the same ring.)

In formula (D-3-5), R ¹ , R ² , n ₂ and n ₃ are the same as R ^a1 , R ^a2 , n _a2 and n _a3 in formula (D-3-2), respectively.

In formula (D-3-5), n ₁ represents the average number of repeating units, and its range is 0.95 to 10.0. According to the manufacturing method described in the Japan Institute of Invention and Innovation Disclosure Technical Bulletin No. 2020-500211, a group of maleimide compounds containing a structure represented by formula (D-3-5) can be obtained. As can be seen from the fact that the average number of repeating units n ₁ in formula (D-3-5) can be smaller than 1.00, the maleimide compound containing the structure represented by formula (D-3-5) thus obtained can contain a maleimide compound having a trimethylindane skeleton repeating unit number of 0. Therefore, the maleimide compound containing the structure represented by formula (D-3-5) can be purified to obtain the (D-2-2) component, excluding the maleimide compound having a trimethylindane skeleton repeating unit number of 0, and the resin composition may contain only the obtained (D-2-2) component. However, even if a maleimide compound having a trimethylindane skeleton repeating unit number of 0 is contained in the resin composition, the effect of the present invention can be obtained. In addition, when purification is omitted, costs can be reduced. Therefore, it is preferable that the resin composition contains a maleimide compound having a structure represented by formula (D-3-5) without excluding a maleimide compound having a trimethylindane skeleton with a repeating unit number of 0.

In formula (D-3-5), the average number of repeating units _n1 is preferably 0.95 or more, more preferably 0.98 or more, even more preferably 1.0 or more, particularly preferably 1.1 or more, and is preferably 10.0 or less, more preferably 8.0 or less, even more preferably 7.0 or less, particularly preferably 6.0 or less. When the average number of repeating units _n1 is within the above range, the effects of the present invention can be significantly obtained. In particular, the glass transition temperature of the resin composition can be effectively increased.

Examples of the structure represented by formula (D-3-5) include the following.

The maleimide compound containing the structure represented by formula (D-3-5) may further contain the structure represented by formula (D-3-4) above. For example, the maleimide compound containing the structure represented by formula (D-3-5) may contain a structure represented by formula (E2-3-4) in combination with the structure represented by formula (D-3-5) when _n2 is 3 or less and ^R1 is not bonded to two or more of the ortho-positions and para-positions relative to the maleimide group of the benzene ring to which the maleimide group is bonded in formula (D-3-5).

The maleimide compound containing the structure represented by formula (D-3-5) preferably has a molecular weight distribution Mw/Mn calculated from gel permeation chromatography (GPC) measurement within a specific range. The molecular weight distribution is a value obtained by dividing the weight average molecular weight Mw by the number average molecular weight Mn, and is expressed as "Mw/Mn". Specifically, the molecular weight distribution Mw/Mn of the maleimide compound containing the structure represented by formula (D-3-5) is preferably 1.0 to 4.0, more preferably 1.1 to 3.8, even more preferably 1.2 to 3.6, and particularly preferably 1.3 to 3.4. When the molecular weight distribution Mw/Mn of the maleimide compound containing the structure represented by formula (D-3-5) is within the above range, the effects of the present invention can be significantly obtained.

Of the maleimide compounds containing a structure represented by formula (D-3-5), the amount of the maleimide compound having an average repeating unit number n ₁ of 0 is preferably in a specific range. When the GPC measurement of the maleimide compound containing a structure represented by formula (D-3-5) is performed, the amount of the maleimide compound having an average repeating unit number n ₁ of 0 can be expressed in area % based on the results of the GPC measurement. In detail, in the chromatogram obtained by the GPC measurement, the amount of the maleimide compound having an average repeating unit number n ₁ of 0 can be expressed by the ratio (area %) of the area of the peak of the maleimide compound having an average repeating unit number n 1 of 0 to the total area of the peak of the maleimide compound containing a structure represented by formula (D-3-5). Specifically, the amount of the maleimide compound having an average repeating unit number n ₁ of 0 is preferably 32 area % or less, more preferably 30 area % or less, and even more preferably 28 area % or less, relative to the total amount of the maleimide compound containing a structure represented by formula (D- _3-5) (100 area %). When the amount of the maleimide compound in which the average number of repeating units _n1 is 0 is within the above range, the effects of the present invention can be significantly obtained.

The maleimide group equivalent of the maleimide compound containing the structure represented by formula (D-3-5) is preferably in the same range as the maleimide group equivalent of the above-mentioned component (D-2-2). When the maleimide group equivalent of the maleimide compound containing the structure represented by formula (D-3-5) is in the above range, the effects of the present invention can be significantly obtained.

（＊は結合手を表す。） (Styryl resin)
The styryl resin has one or more groups selected from a styryl group and a vinylphenyl group in the molecule, and preferably has a vinylphenyl group. The vinylphenyl group is a group having the structure shown below.

(* represents a bond.)

From the viewpoint of obtaining a cured product with a low dielectric tangent, it is more preferable that the styryl resin has two or more vinyl phenyl groups.

From the viewpoint of obtaining a cured product with a low dielectric tangent, it is preferable that the styryl resin has a cyclic structure. The cyclic structure is preferably a divalent cyclic group. The divalent cyclic group may be either a cyclic group containing a non-aromatic ring, for example, an alicyclic structure, or a cyclic group containing an aromatic ring structure. In addition, the styryl resin may have a plurality of divalent cyclic groups.

From the viewpoint of significantly obtaining the intended effect of the present invention, the divalent cyclic group is preferably a 3-membered or more ring, more preferably a 4-membered or more ring, and even more preferably a 5-membered or more ring, and is preferably a 20-membered or less ring, more preferably a 15-membered or less ring, and even more preferably a 10-membered or less ring. In addition, the divalent cyclic group may be a monocyclic structure or a polycyclic structure.

The ring in the divalent cyclic group may have a ring skeleton formed by heteroatoms in addition to carbon atoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms, with oxygen atoms being preferred. The ring may have one heteroatom or two or more heteroatoms.

（２価の基（ａ）、（ｂ）中、Ｒ^５１０、Ｒ^５２０、Ｒ^５５０、Ｒ^５６０、Ｒ^５７０、Ｒ^６１０、及びＲ^６２０は、それぞれ独立にハロゲン原子、炭素原子数が６以下のアルキル基、又はフェニル基を表し、Ｒ^５３０、Ｒ^５４０、Ｒ^５８０、Ｒ^５９０、及びＲ^６００は、それぞれ独立に水素原子、ハロゲン原子、炭素原子数６以下のアルキル基、又はフェニル基を表す。） Specific examples of the divalent cyclic group include the following divalent groups (a) and (b).

(In the divalent groups (a) and (b), R ⁵¹⁰ , R ⁵²⁰ , R ⁵⁵⁰ , R ⁵⁶⁰ , R ⁵⁷⁰ , R ⁶¹⁰ , and R ⁶²⁰ each independently represent a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group, and R ⁵³⁰ , R ⁵⁴⁰ , R ⁵⁸⁰ , R ⁵⁹⁰ , and R ⁶⁰⁰ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group.)

Examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms. Examples of alkyl groups having 6 or less carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups, and methyl groups are preferred. R ⁵¹⁰ , R ⁵²⁰ , R ⁵⁵⁰ , R ⁵⁶⁰ , R ⁵⁷⁰ , R ⁶¹⁰ , and R ⁶²⁰ are preferably methyl groups. R ⁵³⁰ , R ⁵⁴⁰ , R ⁵⁸⁰ , R ⁵⁹⁰ , and R ⁶⁰⁰ are preferably hydrogen atoms or methyl groups.

（式中、Ｒ^７１、Ｒ^７２、Ｒ^７５、Ｒ^７６、Ｒ^７７、Ｒ^８１、Ｒ^８２、Ｒ^８５及びＲ^８６は、それぞれ独立にハロゲン原子、炭素原子数が６以下のアルキル基、又はフェニル基を表し、Ｒ^７３、Ｒ^７４、Ｒ^７８、Ｒ^７９、Ｒ^８０、Ｒ^８３及びＲ^８４は、それぞれ独立に水素原子、ハロゲン原子、炭素原子数６以下のアルキル基、又はフェニル基を表す。ｄ１及びｄ２は、０～３００の整数を表す。但し、ｄ１及びｄ２の一方は０である場合を除く。） In addition, the divalent cyclic group may be a combination of a plurality of divalent cyclic groups. Specific examples of the combination of divalent cyclic groups include the divalent cyclic groups represented by the following formula (D-20).

(In the formula, R ⁷¹ , R ⁷² , R ⁷⁵ , R ⁷⁶ , R ⁷⁷ , R ⁸¹ , R ⁸² , R ⁸⁵ and R ⁸⁶ each independently represent a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group; R ⁷³ , R ⁷⁴ , R ⁷⁸ , R ⁷⁹ , R ⁸⁰ , R ⁸³ and R ⁸⁴ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group; d1 and d2 each independently represent an integer of 0 to 300, except for the case where one of d1 and d2 is 0.)

R ⁷¹ , R ⁷² , R ⁸⁵ and R ⁸⁶ are the same as R ⁵¹⁰ in the divalent group (a). R ⁷³ , R ⁷⁴ , R ⁸³ and R ⁸⁴ are the same as R ⁵³⁰ in the divalent group (a). ^{R 75} , R ⁷⁶ , R ⁷⁷ , R ⁸¹ and R ⁸² are the same as R ⁵⁵⁰ in the divalent group (b). R ⁷⁸ , R ⁷⁹ and R ⁸⁰ are the same as R ⁵⁸⁰ in the divalent group (b).

d1 and d2 represent integers from 0 to 300, except when one of d1 and d2 is 0. d1 and d2 preferably represent integers from 1 to 100, more preferably from 1 to 50, and even more preferably from 1 to 10. d1 and d2 may be the same or different.

The divalent cyclic group may have a substituent. Examples of the substituent include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an arylalkyl group, a silyl group, an acyl group, an acyloxy group, a carboxy group, a sulfo group, a cyano group, a nitro group, a hydroxy group, a mercapto group, and an oxo group. An alkyl group is preferred.

The vinylphenyl group may be directly bonded to the divalent cyclic group, or may be bonded via a divalent linking group. Examples of the divalent linking group include alkylene groups, alkenylene groups, arylene groups, heteroarylene groups, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, -NH-, and the like, and may be groups combining a plurality of these. As the alkylene group, an alkylene group having 1 to 10 carbon atoms is preferable, an alkylene group having 1 to 6 carbon atoms is more preferable, and an alkylene group having 1 to 5 carbon atoms or an alkylene group having 1 to 4 carbon atoms is even more preferable. The alkylene group may be linear, branched, or cyclic. Examples of such alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, and 1,1-dimethylethylene groups, with methylene, ethylene, and 1,1-dimethylethylene being preferred. As the alkenylene group, an alkenylene group having 2 to 10 carbon atoms is preferred, an alkenylene group having 2 to 6 carbon atoms is more preferred, and an alkenylene group having 2 to 5 carbon atoms is even more preferred. As the arylene group and heteroarylene group, an arylene group or heteroarylene group having 6 to 20 carbon atoms is preferred, and an arylene group or heteroarylene group having 6 to 10 carbon atoms is more preferred. As the divalent linking group, an alkylene group is preferred, with a methylene group being particularly preferred.

（式中、Ｒ^９１及びＲ^９２はそれぞれ独立に２価の連結基を表す。環Ｄ１は、２価の環状基を表す。） The styryl resin is preferably represented by the following formula (D-21).

(In the formula, R ⁹¹ and R ⁹² each independently represent a divalent linking group. Ring D1 represents a divalent cyclic group.)

R ⁹¹ and R ⁹² each independently represent a divalent linking group. The divalent linking group is the same as the divalent linking group described above.

Ring D1 represents a divalent cyclic group. Ring D1 is the same as the divalent cyclic group described above.

Ring D1 may have a substituent. The substituent is the same as the substituent that the divalent cyclic group may have.

（ｑ１は、式（Ｄ－２０）中のｄ１と同じであり、ｑ２は、式（Ｄ－２０）中のｄ２と同じである。） Specific examples of the styryl resin are shown below, but the present invention is not limited thereto.

(q1 is the same as d1 in formula (D-20), and q2 is the same as d2 in formula (D-20).)

Styryl resins may be commercially available products, such as "OPE-2St" manufactured by Mitsubishi Gas Chemical Company, Inc. Styryl resins may be used alone or in combination of two or more types.

From the viewpoint of significantly obtaining the desired effects of the present invention, the number average molecular weight of the styryl resin is preferably 3000 or less, more preferably 2500 or less, even more preferably 2000 or less, or 1500 or less. The lower limit is preferably 100 or more, more preferably 300 or more, even more preferably 500 or more, or 1000 or more. The number average molecular weight is the number average molecular weight in terms of polystyrene measured using gel permeation chromatography (GPC).

((Meth)acrylic resin)
The (meth)acrylic resin includes a compound having an acryloyl group or a methacryloyl group in the molecule. From the viewpoint of significantly obtaining the intended effect of the present invention, the (meth)acrylic resin preferably includes a compound having one or more (meth)acryloyl groups per molecule, and more preferably includes a compound having two or more (meth)acryloyl groups per molecule. The term "(meth)acryloyl group" is a general term for acryloyl groups and methacryloyl groups.

From the viewpoint of significantly achieving the intended effect of the present invention, the (meth)acrylic resin preferably has a cyclic structure. The cyclic structure is preferably a monovalent or higher cyclic group, more preferably a divalent cyclic group. The cyclic group may be either a cyclic group containing a non-aromatic ring, for example, an alicyclic structure, or a cyclic group containing an aromatic ring structure. Of these, from the viewpoint of significantly achieving the intended effect of the present invention, a cyclic group containing an alicyclic structure is preferred.

From the viewpoint of significantly obtaining the intended effect of the present invention, the monovalent or higher cyclic group is preferably a 3-membered ring or more, more preferably a 4-membered ring or more, and even more preferably a 5-membered ring or more, and is preferably a 20-membered ring or less, more preferably a 15-membered ring or less, and even more preferably a 10-membered ring or less. In addition, the divalent cyclic group may be a monocyclic structure or a polycyclic structure.

The ring in the monovalent or higher cyclic group may have a ring skeleton constituted by heteroatoms in addition to carbon atoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms, and oxygen atoms are preferred. The ring may have one heteroatom or two or more heteroatoms.

Specific examples of the monovalent or higher cyclic group include the following groups (i) to (xii). Among them, the monovalent or higher cyclic group is preferably (x) or (xi). In the following formula, * represents a bond.

The monovalent or higher cyclic group may have a substituent. Examples of such a substituent include a halogen atom, an alkyl group, an alkoxy group, an aryl group, an arylalkyl group, a silyl group, an acyl group, an acyloxy group, a carboxy group, a sulfo group, a cyano group, a nitro group, a hydroxy group, a mercapto group, and an oxo group. An alkyl group is preferred.

The (meth)acryloyl group may be directly bonded to a monovalent or higher cyclic group, or may be bonded via a divalent linking group. Examples of the divalent linking group include alkylene groups, alkenylene groups, arylene groups, heteroarylene groups, -C(=O)O-, -O-, -NHC(=O)-, -NC(=O)N-, -NHC(=O)O-, -C(=O)-, -S-, -SO-, -NH-, and the like, and may be groups combining a plurality of these. As the alkylene group, an alkylene group having 1 to 10 carbon atoms is preferable, an alkylene group having 1 to 6 carbon atoms is more preferable, and an alkylene group having 1 to 5 carbon atoms or an alkylene group having 1 to 4 carbon atoms is even more preferable. The alkylene group may be linear, branched, or cyclic. Examples of such alkylene groups include methylene, ethylene, propylene, butylene, pentylene, hexylene, and 1,1-dimethylethylene groups, with methylene, ethylene, and 1,1-dimethylethylene being preferred. As the alkenylene group, an alkenylene group having 2 to 10 carbon atoms is preferred, an alkenylene group having 2 to 6 carbon atoms is more preferred, and an alkenylene group having 2 to 5 carbon atoms is even more preferred. As the arylene group and heteroarylene group, an arylene group or heteroarylene group having 6 to 20 carbon atoms is preferred, and an arylene group or heteroarylene group having 6 to 10 carbon atoms is more preferred. Groups combining a plurality of these include oxyalkylene groups and groups in which oxygen atoms and alkylene groups are alternately and repeatedly bonded. As the divalent linking group, an alkylene group is preferred, with a methylene group and a 1,1-dimethylethylene group being particularly preferred.

（式中、Ｒ^１０１及びＲ^１０４はそれぞれ独立にアクリロイル基又はメタクリロイル基を表し、Ｒ^１０２及びＲ^１０３はそれぞれ独立に２価の連結基を表す。環Ｄ２は、２価の環状基を表す。） The (meth)acrylic resin preferably contains a compound represented by the following formula (D-22).

(In the formula, R ¹⁰¹ and R ¹⁰⁴ each independently represent an acryloyl group or a methacryloyl group, R ¹⁰² and R ¹⁰³ each independently represent a divalent linking group, and ring D2 represents a divalent cyclic group.)

R ¹⁰¹ and R ¹⁰⁴ each independently represent an acryloyl group or a methacryloyl group, and an acryloyl group is preferable.

R ¹⁰² and R ¹⁰³ each independently represent a divalent linking group. The divalent linking group is the same as the divalent linking group which may have a (meth)acryloyl group bonded thereto.

Ring D2 represents a divalent cyclic group. Ring D2 is the same as the divalent cyclic group described above. Ring D2 may have a substituent. The substituent is the same as the substituent that the divalent cyclic group described above may have.

Specific examples of the (meth)acrylic resin include the following, but the present invention is not limited to these: In the formula, n represents an integer of 1 to 100.

Commercially available (meth)acrylic resins may be used, such as "A-DOG" manufactured by Shin-Nakamura Chemical Co., Ltd., "DCP-A" manufactured by Kyoeisha Chemical Co., Ltd., "NPDGA", "FM-400", "R-687", "THE-330", "PET-30", and "DPHA" manufactured by Nippon Kayaku Co., Ltd., and "NK Ester DCP" and "A-LEN" manufactured by Shin-Nakamura Chemical Co., Ltd.

From the viewpoint of significantly achieving the intended effect of the present invention, the (meth)acryloyl group equivalent of the (meth)acrylic resin is preferably 30 g/eq. to 400 g/eq., more preferably 50 g/eq. to 300 g/eq., and even more preferably 75 g/eq. to 200 g/eq. The (meth)acryloyl group equivalent is the mass of a compound containing one equivalent of a (meth)acryloyl group.

(Allyl resin)
The allyl resin has at least one allyl group in the molecule. The allyl resin more preferably has two or more allyl groups in one molecule. The upper limit is not particularly limited, but is preferably 10 or less, more preferably 5 or less.

In addition, from the viewpoint of significantly achieving the intended effect of the present invention, it is preferable that the allyl resin has, in addition to the allyl group, any of a benzoxazine ring, a phenol ring, an isocyanuric ring, and a carboxylic acid derivative having a cyclic structure.

The allyl resin having a benzoxazine ring is preferably bonded to either the nitrogen atom of the benzoxazine ring or the benzene ring, and more preferably bonded to the nitrogen atom.

Examples of allyl resins having a phenol ring include cresol resins containing an allyl group, novolac-type phenol resins containing an allyl group, and cresol novolac resins containing an allyl group.

In the allyl resin having an isocyanuric structure, it is preferable that the nitrogen atom of the isocyanuric structure is directly bonded to the allyl group. Examples of allyl resins having an isocyanuric structure include allyl isocyanurate, diallyl isocyanurate, triallyl isocyanurate, etc.

As the allyl resin having a carboxylic acid derivative having a cyclic structure, an allyl carboxylate having a cyclic structure is preferable. The cyclic structure may be either a non-aromatic ring, such as a cyclic group containing an alicyclic structure, or a cyclic group containing an aromatic ring structure. In addition, the cyclic group may have a ring skeleton formed by heteroatoms other than carbon atoms. Examples of heteroatoms include oxygen atoms, sulfur atoms, and nitrogen atoms, and nitrogen atoms are preferable. The ring may have one heteroatom or two or more heteroatoms.

Examples of carboxylic acids having a cyclic structure include isocyanuric acid, diphenic acid, phthalic acid, and cyclohexanedicarboxylic acid. Examples of allyl resins having a carboxylic acid derivative having a cyclic structure include allyl isocyanurate, diallyl isocyanurate, triallyl isocyanurate, diallyl diphenate, allyl diphenate, ortho-diallyl phthalate, meth-diallyl phthalate, para-diallyl phthalate, allyl cyclohexanedicarboxylate, and diallyl cyclohexanedicarboxylate.

Allyl resins may be commercially available products. Examples of commercially available products include "MEH-8000H" and "MEH-8005" (allyl resins having a phenol ring) manufactured by Meiwa Kasei Co., Ltd.; "ALP-d" (allyl resins having a benzoxazine ring) manufactured by Shikoku Kasei Kogyo Co., Ltd.; "L-DAIC" (allyl resins having an isocyanuric ring) manufactured by Shikoku Kasei Kogyo Co., Ltd.; "TAIC" (allyl resins having an isocyanuric ring (triallyl isocyanurate)) manufactured by Nippon Kasei Co., Ltd.; "MDAC" (allyl resins having a cyclohexanedicarboxylic acid derivative) manufactured by Osaka Soda Co., Ltd.; "DAD" (diallyl diphenate) manufactured by Nissho Techno Fine Chemical Co., Ltd.; and "Daiso DAP Monomer" (ortho-diallyl phthalate) manufactured by Osaka Soda Co., Ltd.

From the viewpoint of significantly obtaining the intended effect of the present invention, the allyl group equivalent of the allyl resin is preferably 20 g/eq. to 1000 g/eq., more preferably 50 g/eq. to 500 g/eq., and even more preferably 100 g/eq. to 300 g/eq. The allyl group equivalent is the mass of a compound containing one equivalent of an allyl group.

From the viewpoint of obtaining a significant effect of the present invention, the content of component (D) is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 2% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 3% by mass or less, assuming that the non-volatile components in the resin composition are 100% by mass.

<(E) Curing Agent>
The resin composition may further contain a curing agent (E) as an optional component in addition to the above-mentioned components. However, the (E) component does not include those corresponding to the (A) to (D) components. As the (E) curing agent, a compound having a function of reacting with the (A) component to cure the resin composition can be used, and examples thereof include a phenol-based curing agent, a naphthol-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, a carbodiimide-based curing agent, and an active ester-based curing agent. Among them, from the viewpoint of improving the insulation reliability, the (E) curing agent is preferably one or more of a carbodiimide-based curing agent, a phenol-based curing agent, and a naphthol-based curing agent. The (E) curing agent may be used alone or in combination of two or more.

As the phenol-based hardener and naphthol-based hardener, from the viewpoint of heat resistance and water resistance, a phenol-based hardener having a novolac structure or a naphthol-based hardener having a novolac structure is preferred. Also, from the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenol-based hardener is preferred, and a triazine skeleton-containing phenol-based hardener is more preferred.

Specific examples of phenol-based and naphthol-based curing agents include "MEH-7700", "MEH-7810", and "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., "NHN", "CBN", and "GPH" manufactured by Nippon Kayaku Co., Ltd., "SN170", "SN180", "SN190", "SN475", "SN485", "SN495", "SN-495V", "SN375", and "SN395" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., and "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA3018-50P", and "EXB-9500" manufactured by DIC Corporation.

Specific examples of benzoxazine-based curing agents include "HFB2006M" manufactured by Showa Polymer Co., Ltd., and "P-d" and "F-a" manufactured by Shikoku Chemical Industry Co., Ltd.

Examples of cyanate ester curing agents include bifunctional cyanate resins such as bisphenol A dicyanate, polyphenol cyanate, oligo(3-methylene-1,5-phenylene cyanate), 4,4'-methylenebis(2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanate phenylmethane), bis(4-cyanate-3,5-dimethylphenyl)methane, 1,3-bis(4-cyanate phenyl-1-(methylethylidene))benzene, bis(4-cyanate phenyl)thioether, and bis(4-cyanate phenyl)ether; polyfunctional cyanate resins derived from phenol novolac and cresol novolac; and prepolymers in which these cyanate resins have been partially converted to triazine. Specific examples of cyanate ester-based hardeners include Lonza Japan's "PT30" and "PT60" (phenol novolac-type multifunctional cyanate ester resins), "ULL-950S" (multifunctional cyanate ester resin), "BA230" and "BA230S75" (prepolymers in which part or all of bisphenol A dicyanate has been converted to triazine and formed into a trimer).

Specific examples of carbodiimide-based curing agents include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.

There are no particular limitations on the active ester curing agent, but generally compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are preferably used. The active ester curing agent is preferably one obtained by a condensation reaction between a carboxylic acid compound and/or a thiocarboxylic acid compound and a hydroxy compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred. Examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of phenol compounds or naphthol compounds include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolak. Here, "dicyclopentadiene-type diphenol compounds" refer to diphenol compounds obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Specifically, active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated product of phenol novolac, and active ester compounds containing a benzoylated product of phenol novolac are preferred, and among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. The term "dicyclopentadiene-type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Commercially available active ester curing agents include active ester compounds containing a dicyclopentadiene-type diphenol structure such as "EXB-9451", "EXB-9460", "EXB-9460S", "HPC-8000-65T", "HPC-8000H-65TM", and "HPC-8000L-65TM" (manufactured by DIC Corporation), active ester compounds containing a naphthalene structure such as "EXB-9416-70BK", "EXB-8100L-65T", "EXB-8150-65T", "EXB-8150L-65T", "HPC-8150-60T", "HPC-8150-62T", and "HP-B-8151-62T" (manufactured by DIC Corporation), and phenol novolac Examples of active ester compounds containing acetylated compounds include "DC808" (manufactured by Mitsubishi Chemical Corporation), active ester compounds containing benzoylated phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), active ester curing agents that are acetylated phenol novolac include "DC808" (manufactured by Mitsubishi Chemical Corporation), active ester curing agents that are benzoylated phenol novolac include "YLH1026" (manufactured by Mitsubishi Chemical Corporation), "YLH1030" (manufactured by Mitsubishi Chemical Corporation), and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), and an active ester compound containing a styryl group includes "PC1300-02-65MA" (manufactured by Air Water Corporation).

When the resin composition contains the (E) component, the ratio of the amount of the epoxy resin to the (C) and (E) components is preferably in the range of 1:0.01 to 1:5, more preferably 1:0.3 to 1:3, and even more preferably 1:0.5 to 1:2, in terms of the ratio of [total number of epoxy groups in the epoxy resin]:[total number of active groups in the (C) and (E) components]. Here, the "number of epoxy groups in the epoxy resin" refers to the total value obtained by dividing the mass of the non-volatile components of the epoxy resin present in the resin composition by the epoxy equivalent. In addition, the "number of active groups in the (C) and (E) components" refers to the total value obtained by dividing the mass of the non-volatile components of the (C) and (E) components present in the resin composition by the active group equivalent. By setting the ratio of the amount of the epoxy resin to the (C) and (E) components within this range, the effects of the present invention can be obtained significantly.

The ratio of the amount of epoxy resin to all of the (E) components is the ratio of [total number of epoxy groups in the epoxy resin]:[total number of active groups in the (E) components], and is preferably in the range of 1:0.01 to 1:1, more preferably 1:0.03 to 1:0.5, and even more preferably 1:0.05 to 1:0.3. Here, the "number of active groups in the (E) components" refers to the total value obtained by dividing the mass of the non-volatile components of the (E) components present in the resin composition by the active group equivalent. By setting the ratio of the amount of epoxy resin to the curing agent as the (E) components within this range, the effects of the present invention can be obtained significantly.

From the viewpoint of obtaining the desired effect of the present invention remarkably, the content of component (E) is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, and even more preferably 1% by mass or more, when the non-volatile components in the resin composition are taken as 100% by mass. The upper limit is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 8% by mass or less.

<(F) Curing Accelerator>
In addition to the above-mentioned components, the resin composition may further contain, as an optional component, a curing accelerator as component (F).

Examples of the (F) component include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and metal-based curing accelerators. The (F) component may be used alone or in combination of two or more types.

Examples of phosphorus-based curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, etc., with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

Examples of amine-based curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred.

Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 1,2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4 -diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl Examples of the imidazole compounds include 1-dodecyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline, 2-phenylimidazoline, and adducts of imidazole compounds and epoxy resins, with 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole being preferred.

Commercially available imidazole curing accelerators may be used, such as "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Examples of guanidine-based curing accelerators include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, and 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene. Examples include o[4.4.0]dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, and 1-(o-tolyl)biguanide, and dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene are preferred.

Metal-based curing accelerators include, for example, organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organocopper complexes such as copper (II) acetylacetonate, organozinc complexes such as zinc (II) acetylacetonate, organoiron complexes such as iron (III) acetylacetonate, organonickel complexes such as nickel (II) acetylacetonate, and organomanganese complexes such as manganese (II) acetylacetonate. Organometallic salts include, for example, zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

From the viewpoint of significantly obtaining the desired effect of the present invention, the content of component (F) is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and even more preferably 0.01% by mass or more, and is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, when the non-volatile components in the resin composition are taken as 100% by mass.

<(G) Other Additives>
The resin composition may further contain other additives as optional components in addition to the above-mentioned components. Examples of such additives include thermoplastic resins, elastomers, organic fillers, thickeners, defoamers, leveling agents, adhesion promoters, flame retardants, etc. These may be used alone or in combination of two or more at any ratio.

The resin composition can be produced, for example, by mixing the above-mentioned components in any order. In addition, during the process of mixing each component, heating and/or cooling may be performed by appropriately adjusting the temperature. In addition, each component may be uniformly dispersed by stirring using a stirring device such as a mixer during or after mixing. Furthermore, the resin composition may be subjected to a degassing treatment as necessary.

<Physical properties and applications of resin composition>
Since the resin composition contains the (A) component, the (B) component, and the (C) component in combination, it is possible to obtain a cured product having a low dielectric tangent, excellent peel strength, copper foil adhesion, and excellent copper foil adhesion after HAST test. In addition, the resin composition can usually obtain a cured product having a low arithmetic mean roughness Ra and suppressed lamination irregularities.

The cured product obtained by thermally curing the resin composition at 190°C for 90 minutes has a low dielectric loss tangent. Therefore, when an insulating layer is formed from this cured product, an insulating layer with a low dielectric loss tangent can be obtained. For example, the dielectric loss tangent Df of the cured product obtained by curing the resin composition under the conditions described in the examples below is preferably 0.010 or less, more preferably 0.005 or less, and even more preferably 0.003 or less. The lower limit of the dielectric loss tangent of the cured product is not particularly limited, but can be 0.0001 or more. The dielectric loss tangent of the cured product can be measured by the method described in the examples.

The resin composition is heated at 130°C for 30 minutes, and then heat-cured at 170°C for 30 minutes to obtain a cured product that can increase the plating peel strength between the resin composition and the plating. Therefore, when an insulating layer is formed from this cured product, an insulating layer with high peel strength between the insulating layer and the conductor layer can be obtained. For example, when an insulating layer and a plated conductor layer are formed by the method described in the examples below, the peel strength between the insulating layer and the conductor layer is preferably 0.3 kgf/cm or more, more preferably 0.4 kgf/cm or more, and particularly preferably 0.5 kgf/cm or more. The upper limit of the plating peel strength is not particularly limited, but can be, for example, 10.0 kgf/cm or less. The peel strength can be measured by the method described in the examples.

The resin composition is heated at 100°C for 30 minutes, and then thermally cured at 170°C for 30 minutes to obtain a cured product that can enhance the copper foil adhesion between the resin composition and the copper foil. Therefore, when an insulating layer is formed from this cured product, an insulating layer with high peel strength between the resin composition and the copper foil can be obtained. For example, when the insulating layer and the copper foil are formed by the method described in the examples below, the copper foil adhesion between the resin composition and the copper foil is preferably 0.3 kgf/cm or more, more preferably 0.4 kgf/cm or more, and particularly preferably 0.5 kgf/cm or more. The upper limit of the copper foil adhesion is not particularly limited, but can be, for example, 10.0 kgf/cm or less. The copper foil adhesion can be measured by the method described in the examples.

The resin composition is heated at 100°C for 30 minutes, and then thermally cured at 170°C for 30 minutes to obtain a cured product that can enhance the copper foil adhesion between the resin composition and the copper foil after the HAST test. Therefore, when an insulating layer is formed from this cured product, an insulating layer with high peel strength between the resin composition and the copper foil after the HAST test can be obtained. For example, the copper foil adhesion between the resin composition and the copper foil after the HAST test is performed by forming an insulating layer and a copper foil using the method described in the examples below and leaving the insulating layer and the copper foil for 100 hours under conditions of 130°C and a humidity of 85% RH is preferably 0.1 kgf/cm or more, more preferably 0.2 kgf/cm or more, and particularly preferably 0.3 kgf/cm or more. The upper limit of the copper foil adhesion after the HAST test is not particularly limited, but can be, for example, 10.0 kgf/cm or less. The copper foil adhesion after the HAST test can be measured by the method described in the examples.

The resin composition is thermally cured at 190°C for 90 minutes to produce a cured product with a high elongation at break. Therefore, when an insulating layer is formed from this cured product, an insulating layer with a high elongation at break is obtained. The elongation at break is preferably 0.5% or more, more preferably 1% or more, and even more preferably 2% or more. The upper limit of the elongation at break is not particularly limited, but may be 10% or less. The elongation at break can be measured by the method described in the examples.

The resin composition is heated at 100°C for 30 minutes, and then thermally cured at 170°C for 30 minutes. The roughened surface obtained by roughening the surface of the cured product usually exhibits the characteristic of a low arithmetic mean roughness Ra. Therefore, this cured product provides an insulating layer with a low arithmetic mean roughness. The arithmetic mean roughness Ra is preferably 100 nm or less, more preferably 60 nm or less, and even more preferably 55 nm or less. The lower limit of the arithmetic mean roughness can be 10 nm or more. The arithmetic mean roughness (Ra) can be measured by the method described in the examples.

The cured product obtained by heating the resin composition at 100°C for 30 minutes and then heat curing at 170°C for 30 minutes usually exhibits the characteristic of suppressing the occurrence of laminate irregularities. Even if a resin sheet described below is laminated on the inner layer substrate and the resin composition layer is heat cured, the occurrence of irregularities on the surface of the heat cured resin composition layer can be suppressed and the surface of the heat cured resin composition layer can be made uniform. The evaluation of laminate irregularities can be measured, for example, by the method described in the examples.

The resin composition according to one embodiment of the present invention is suitable as a resin composition for insulating purposes, and is particularly suitable as a resin composition for forming an insulating layer. Thus, for example, the resin composition is suitable as a resin composition for forming an insulating layer of a printed wiring board (resin composition for forming an insulating layer of a printed wiring board). The resin composition is suitable as a resin composition for forming an interlayer insulating layer of a printed wiring board (resin composition for forming an interlayer insulating layer of a printed wiring board). The resin composition is also suitable as a resin composition for forming an insulating layer for forming a conductor layer (including a rewiring layer) formed on an insulating layer (resin composition for forming an insulating layer for forming a conductor layer). The resin composition can also be used in a wide range of applications in which the resin composition can be used, such as resin sheets, sheet-like laminate materials such as prepregs, solder resists, underfill materials, die bonding materials, semiconductor encapsulants, hole-filling resins, component-embedding resins, multi-chip packages, package-on-packages, wafer-level packages, panel-level packages, and system-in-packages.

Furthermore, for example, when a semiconductor chip package is manufactured through the following steps (1) to (6), the resin composition according to the present embodiment is also suitable as a resin composition for forming a rewiring formation layer as an insulating layer for forming a rewiring layer (resin composition for forming a rewiring formation layer) and as a resin composition for sealing a semiconductor chip (resin composition for sealing a semiconductor chip). When a semiconductor chip package is manufactured, a rewiring layer may be further formed on the sealing layer.
(1) A step of laminating a temporary fixing film on a substrate;
(2) A step of temporarily fixing a semiconductor chip on a temporary fixing film;
(3) forming an encapsulation layer on the semiconductor chip;
(4) peeling the substrate and the temporary fixing film from the semiconductor chip;
(5) forming a rewiring formation layer as an insulating layer on the surface of the semiconductor chip from which the base material and the temporary fixing film have been peeled off; and (6) forming a rewiring layer as a conductor layer on the rewiring formation layer.

The above-mentioned resin composition can also be used when the printed wiring board is a circuit board with built-in components.

[Resin sheet]
The resin sheet of the present invention includes a support and a resin composition layer formed from the resin composition of the present invention provided on the support.

The thickness of the resin composition layer is preferably 50 μm or less, more preferably 40 μm or less, and even more preferably 30 μm or less, from the viewpoint of making the printed wiring board thinner and being able to provide a cured product with excellent insulation even if the cured product of the resin composition is a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, but can usually be 5 μm or more.

Examples of the support include films made of plastic materials, metal foils, and release paper, with films made of plastic materials and metal foils being preferred.

When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate (hereinafter sometimes abbreviated as "PEN"), polycarbonate (hereinafter sometimes abbreviated as "PC"), acrylics such as polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide, etc. Among these, polyethylene terephthalate and polyethylene naphthalate are preferred, with inexpensive polyethylene terephthalate being particularly preferred.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. As the copper foil, a foil made of a single metal, copper, or an alloy of copper and another metal (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used.

The support may be subjected to a matte treatment, corona treatment, or antistatic treatment on the surface that is to be bonded to the resin composition layer.

As the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. Examples of the release agent used in the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. The support with a release layer may be a commercially available product, such as "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation, "Lumirror T60" manufactured by Toray Industries, "Purex" manufactured by Teijin Limited, and "Unipeel" manufactured by Unitika Limited, which are PET films having a release layer mainly composed of an alkyd resin-based release agent.

The thickness of the support is not particularly limited, but is preferably in the range of 5 μm to 75 μm, and more preferably in the range of 10 μm to 60 μm. When using a support with a release layer, it is preferable that the thickness of the entire support with the release layer is in the above range.

In one embodiment, the resin sheet may further include other layers as necessary. Examples of such other layers include a protective film similar to the support provided on the surface of the resin composition layer that is not bonded to the support (i.e., the surface opposite the support). The thickness of the protective film is not particularly limited, but is, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to suppress adhesion of dirt and the like and scratches on the surface of the resin composition layer.

The resin sheet can be produced, for example, by preparing a resin varnish by dissolving the resin composition in an organic solvent, applying this resin varnish onto a support using a die coater or the like, and then drying it to form a resin composition layer.

Examples of organic solvents include ketones such as acetone, methyl ethyl ketone (MEK), and cyclohexanone; acetate esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide (DMAc), and N-methylpyrrolidone. The organic solvents may be used alone or in combination of two or more.

Drying may be performed by known methods such as heating or blowing hot air. There are no particular limitations on the drying conditions, but drying is performed so that the content of organic solvent in the resin composition layer is 10% by mass or less, preferably 5% by mass or less. Although it varies depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% by mass to 60% by mass of organic solvent, the resin composition layer can be formed by drying at 50°C to 150°C for 3 to 10 minutes.

The resin sheet can be stored in a roll. If the resin sheet has a protective film, it can be used by peeling off the protective film.

[Printed wiring board]
A printed wiring board according to one embodiment of the present invention includes an insulating layer formed of a cured product obtained by curing the above-described resin composition.

The printed wiring board can be produced, for example, by using the above-mentioned resin sheet by a method including the following steps (I) and (II).
(I) a step of laminating a resin sheet on an inner layer substrate so that a resin composition layer of the resin sheet is bonded to the inner layer substrate; and (II) a step of curing the resin composition layer to form an insulating layer.

The "inner layer substrate" used in step (I) is a member that will be the substrate of the printed wiring board, and examples thereof include glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. The substrate may have a conductor layer on one or both sides, and the conductor layer may be patterned. An inner layer substrate having a conductor layer formed on one or both sides of the substrate may be called an "inner layer circuit substrate." In addition, intermediate products on which an insulating layer and/or a conductor layer is to be formed during the manufacture of a printed wiring board are also included in the "inner layer substrate." When the printed wiring board is a circuit board with built-in components, an inner layer substrate with built-in components may be used.

The lamination of the inner layer substrate and the resin sheet can be carried out, for example, by heat-pressing the resin sheet to the inner layer substrate from the support side. Examples of the member for heat-pressing the resin sheet to the inner layer substrate (hereinafter also referred to as the "heat-pressing member") include a heated metal plate (such as a SUS panel) or a metal roll (such as a SUS roll). Note that rather than pressing the heat-pressing member directly onto the resin sheet, it is preferable to press it via an elastic material such as heat-resistant rubber so that the resin sheet can sufficiently follow the surface irregularities of the inner layer substrate.

The lamination of the inner layer substrate and the resin sheet may be performed by a vacuum lamination method. In the vacuum lamination method, the heat-pressure bonding temperature is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C, the heat-pressure bonding pressure is preferably in the range of 0.098MPa to 1.77MPa, more preferably in the range of 0.29MPa to 1.47MPa, and the heat-pressure bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The lamination may be performed under reduced pressure conditions, preferably at a pressure of 26.7hPa or less.

Lamination can be performed using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nikko Materials Co., Ltd., and a batch type vacuum pressure laminator.

After lamination, the laminated resin sheets may be smoothed under atmospheric pressure, for example by pressing a thermocompression member from the support side. The pressing conditions for the smoothing treatment may be the same as the thermocompression conditions for the lamination. The smoothing treatment may be performed using a commercially available laminator. Note that lamination and smoothing treatment may be performed consecutively using the commercially available vacuum laminator.

The support may be removed between steps (I) and (II), or after step (II).

In step (II), the resin composition layer is cured to form an insulating layer made of a cured product of the resin composition. The curing conditions for the resin composition layer are not particularly limited, and the conditions employed for forming an insulating layer of a printed wiring board may be used. The resin composition layer may be cured by irradiation with active energy rays such as ultraviolet rays, but is usually thermally cured by heating.

For example, the thermal curing conditions for the resin composition layer vary depending on the type of resin composition, but in one embodiment, the curing temperature is preferably 120°C to 240°C, more preferably 150°C to 220°C, and even more preferably 170°C to 210°C. The curing time is preferably 5 minutes to 120 minutes, more preferably 10 minutes to 100 minutes, and even more preferably 15 minutes to 100 minutes.

Before the resin composition layer is thermally cured, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermally curing the resin composition layer, the resin composition layer may be preheated at a temperature of 50°C to 120°C, preferably 60°C to 115°C, and more preferably 70°C to 110°C for 5 minutes or more, preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and even more preferably 15 minutes to 100 minutes.

The method for producing a printed wiring board may further include (III) a step of drilling holes in the insulating layer, (IV) a step of roughening the insulating layer, and (V) a step of forming a conductor layer. When the support is removed after step (II), the removal of the support may be performed between step (II) and step (III), between step (III) and step (IV), or between step (IV) and step (V). In addition, the formation of the insulating layer and the conductor layer in steps (I) to (V) may be repeated as necessary to form a multilayer wiring board.

Step (III) is a step of drilling holes in the insulating layer, which allows holes such as via holes and through holes to be formed in the insulating layer. Step (III) may be performed using, for example, a drill, a laser, plasma, etc., depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be appropriately determined depending on the design of the printed wiring board.

Step (IV) is a step of roughening the insulating layer. Usually, smears are also removed in this step (IV). The procedure and conditions of the roughening treatment are not particularly limited. For example, the insulating layer can be roughened by carrying out a swelling treatment using a swelling liquid, a roughening treatment using an oxidizing agent, and a neutralization treatment using a neutralizing liquid in this order.

Examples of the swelling liquid used in the roughening treatment include an alkaline solution, a surfactant solution, and the like, and an alkaline solution is preferred. As the alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferred. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan. The swelling treatment using the swelling liquid is not particularly limited, but can be performed by, for example, immersing the insulating layer in a swelling liquid at 30°C to 90°C for 1 to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40°C to 80°C for 5 to 15 minutes.

The oxidizing agent used in the roughening treatment may be, for example, an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment using an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60°C to 100°C for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Commercially available oxidizing agents include, for example, alkaline permanganate solutions such as "Concentrate Compact CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan.

The neutralizing solution used in the roughening treatment is preferably an acidic aqueous solution, and a commercially available product is, for example, "Reduction Solution Securigant P" manufactured by Atotech Japan. Treatment with a neutralizing solution can be carried out by immersing the surface that has been roughened with an oxidizing agent in a neutralizing solution at 30°C to 80°C for 5 to 30 minutes. From the standpoint of workability, etc., it is preferable to immerse the object that has been roughened with an oxidizing agent in a neutralizing solution at 40°C to 70°C for 5 to 20 minutes.

In one embodiment, the arithmetic mean roughness Ra of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. The lower limit is not particularly limited, and may be, for example, 1 nm or more, 2 nm or more, etc. The root mean square roughness (Rq) of the insulating layer surface after the roughening treatment is preferably 500 nm or less, more preferably 400 nm or less, and even more preferably 300 nm or less. The lower limit is not particularly limited, and may be, for example, 1 nm or more, 2 nm or more, etc. The arithmetic mean roughness (Ra) and root mean square roughness (Rq) of the insulating layer surface can be measured using a non-contact surface roughness meter.

Step (V) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains one or more metals selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. The conductor layer may be a single metal layer or an alloy layer, and examples of the alloy layer include layers formed from alloys of two or more metals selected from the above group (e.g., nickel-chromium alloy, copper-nickel alloy and copper-titanium alloy). Among these, from the viewpoints of versatility in forming the conductor layer, cost, ease of patterning, etc., a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferred, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferred, and a single metal layer of copper is even more preferred.

The conductor layer may be a single-layer structure, or a multi-layer structure in which two or more single metal layers or alloy layers made of different types of metals or alloys are laminated. When the conductor layer has a multi-layer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

The thickness of the conductor layer depends on the desired printed wiring board design, but is generally between 3 μm and 35 μm, preferably between 5 μm and 30 μm.

The conductor layer is preferably formed by plating. For example, the surface of the insulating layer can be plated by a semi-additive method, a full-additive method, or the like to form a conductor layer having a desired wiring pattern. From the viewpoint of ease of production, it is preferable to form the conductor layer by a semi-additive method. Below, an example of forming a conductor layer by a semi-additive method is shown.

A plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a portion of the plating seed layer corresponding to the desired wiring pattern. A metal layer is formed on the exposed plating seed layer by electrolytic plating, and the mask pattern is then removed. Thereafter, unnecessary plating seed layer is removed by etching or the like, and a conductor layer having the desired wiring pattern can be formed.

[Semiconductor device]
A semiconductor device according to an embodiment of the present invention includes the above-mentioned printed wiring board. This semiconductor device can be manufactured using the above-mentioned printed wiring board.

Semiconductor devices include various semiconductor devices used in electrical appliances (e.g., computers, mobile phones, digital cameras, and televisions) and vehicles (e.g., motorcycles, automobiles, trains, ships, and aircraft).

The present invention will be specifically described below with reference to examples. However, the present invention is not limited to the following examples. In the following description, "parts" and "%" representing amounts mean "parts by mass" and "% by mass", respectively, unless otherwise specified. Furthermore, the operations described below were carried out in an environment of normal temperature and pressure, unless otherwise specified.

[Synthesis Example 1: Synthesis of active ester compound A]
In a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube, and a stirrer, 404 parts by mass of 1-naphthol, 560 parts by mass of toluene, 150 parts by mass of bishydroxymethylbiphenyl, and 6 parts by mass of paratoluenesulfonic acid monohydrate were charged. The contents of the flask were heated to 120°C while stirring, and reacted by stirring at 120°C for 1 hour. After the reaction was completed, 4 parts by mass of 49% aqueous sodium hydroxide was added to neutralize the mixture, and then 400 parts by mass of toluene was added and washed three times with 200 parts by mass of water. Toluene and the like were distilled off under heating and reduced pressure conditions, and 510 parts by mass of a mixture (A) containing unreacted 1-naphthol and polynaphthol resin was obtained. The hydroxyl group equivalent of the obtained mixture (A) was 189 g/equivalent.

141 parts by mass of isophthalic acid chloride and 1000 parts by mass of toluene were charged into a flask equipped with a thermometer, a dropping funnel, a cooling tube, a fractionating tube, and a stirrer, and dissolved while the system was substituted with nitrogen under reduced pressure. Next, 264 parts by mass of the mixture (A) obtained above was charged and dissolved while the system was substituted with nitrogen under reduced pressure. 0.4 g of tetrabutylammonium bromide was added, and while purging with nitrogen gas, the reaction system was controlled to 60°C or less, and 280 parts by mass of 20% aqueous sodium hydroxide solution was dropped over 3 hours. After the dropwise addition was completed, the mixture was stirred for 1 hour to react. After the reaction was completed, the reaction mixture was left to stand and separated, and the aqueous layer was removed. Water was added to the remaining organic layer and stirred and mixed for about 15 minutes, and the mixture was left to stand and separated, and the aqueous layer was removed. This operation was repeated until the pH of the aqueous layer reached 7, and then toluene and the like were distilled off under heated and reduced pressure conditions to obtain 340 parts by mass of active ester compound A. The functional group equivalent of active ester compound A was 253 g/equivalent, and the softening point measured according to JIS K7234 was 144°C.

[Synthesis Example 2: Synthesis of Maleimide Compound A]
An MEK solution (non-volatile component 62% by mass) of maleimide compound A (Mw/Mn=1.81, t″=1.47 (mainly 1, 2 or 3)) represented by the following formula (1) synthesized by the method described in Synthesis Example 1 in the Japan Institute of Invention and Innovation Disclosure Technical Journal No. 2020-500211 was prepared.

[Example 1]
Three parts of a bisphenol type epoxy resin ("ZX1059" manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 160 to 170 g/eq.), three parts of a naphthalene type epoxy resin ("HP-4032-SS" manufactured by DIC Corporation, epoxy equivalent 144 g/eq.), three parts of a biphenyl aralkyl type epoxy resin ("NC-3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 271 g/eq.), and three parts of a naphthol aralkyl skeleton epoxy resin ("ESN-475V" manufactured by Nippon Steel Chemical & Material Co., Ltd., epoxy equivalent 330 g/eq.) were dissolved in 10 parts of MEK and 10 parts of cyclohexanone. To this were added 30 parts of active ester compound A (prepared as a toluene solution with a nonvolatile content of 65% by mass), 92 parts of an inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573"), and 0.2 parts of a curing accelerator (manufactured by Shikoku Chemical Industry Co., Ltd., "1B2PZ"), and the mixture was uniformly dispersed using a high-speed rotating mixer to obtain a resin varnish.

[Example 2]
In Example 1,
1) The amount of active ester compound A (prepared in a toluene solution with a non-volatile content of 65% by mass) was changed from 30 parts to 26 parts,
2) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 92 parts to 90 parts,
3) The amount of the curing accelerator (manufactured by Shikoku Chemical Industry Co., Ltd., "1B2PZ") was changed from 0.2 parts to 0.02 parts.
4) 3 parts of a triazine-containing cresol novolac type curing agent (DIC Corporation's "LA-3018-50P", a 2-methoxy-1-propanol solution with a non-volatile content of 50% by mass) was used.
5) 1 part of carbodiimide resin (Nisshinbo Chemical's "V-03", a toluene solution with a non-volatile content of 50% by weight) was used.
A resin varnish was obtained in the same manner as in Example 1 except for the above.

[Example 3]
In Example 2,
1) The amount of active ester compound A (prepared in a toluene solution with a non-volatile content of 65% by mass) was changed from 26 parts to 18 parts,
2) 8 parts of a naphthalene skeleton-containing active ester compound ("HPC-8150-62T" manufactured by DIC Corporation, a toluene solution with a nonvolatile content of 61.5% by mass) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 4]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 5 parts of a thermosetting resin ("OPE-2St-1200" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution with a non-volatile content of 65% by mass) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 5]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 6 parts of the maleimide compound A synthesized in Synthesis Example 2 (MEK solution, non-volatile component 62% by mass) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 6]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 5 parts of a thermosetting resin ("MIR-3000-70MT" manufactured by Nippon Kayaku Co., Ltd., a toluene/MEK solution with a non-volatile content of 70% by weight) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 7]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 4 parts of a thermosetting resin ("SLK-6895" manufactured by Shin-Etsu Chemical Co., Ltd.) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 8]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 4 parts of a thermosetting resin ("A-DOG" manufactured by Shin-Nakamura Chemical Co., Ltd.) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 9]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 4 parts of a thermosetting resin ("DCP-A" manufactured by Shin-Nakamura Chemical Co., Ltd.) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Example 10]
In Example 2,
1) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 100 parts,
2) 4 parts of a thermosetting resin ("A-LEN" manufactured by Shin-Nakamura Chemical Co., Ltd.) was used.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Comparative Example 1]
In Example 1,
1) 30 parts of the active ester compound A (prepared as a toluene solution with a non-volatile content of 65% by mass) was replaced with 29 parts of a naphthalene skeleton-containing active ester compound (DIC Corporation's "HPC-8150-62T", a toluene solution with a non-volatile content of 61.5% by mass),
2) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 92 parts to 90 parts.
A resin varnish was obtained in the same manner as in Example 1 except for the above.

[Comparative Example 2]
In Example 1,
1) 30 parts of the active ester compound A (prepared as a toluene solution with a non-volatile content of 65% by mass) was replaced with 26 parts of a dicyclopentadiene skeleton-containing active ester compound (DIC Corporation's "HPC-8000-65T", a toluene solution with a non-volatile content of 65% by mass),
2) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 92 parts to 87 parts.
A resin varnish was obtained in the same manner as in Example 1 except for the above.

[Comparative Example 3]
In Example 2,
1) 26 parts of the active ester compound A (prepared as a toluene solution with a non-volatile content of 65% by mass) was replaced with 25 parts of a naphthalene skeleton-containing active ester compound (DIC Corporation's "HPC-8150-62T", a toluene solution with a non-volatile content of 61.5% by mass),
2) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 88 parts.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

[Comparative Example 4]
In Example 2,
1) 26 parts of the active ester compound A (prepared as a toluene solution with a non-volatile content of 65% by mass) was replaced with 23 parts of a dicyclopentadiene skeleton-containing active ester compound (DIC Corporation's "HPC-8000-65T", a toluene solution with a non-volatile content of 65% by mass),
2) The amount of inorganic filler (spherical silica (manufactured by Admatechs, "SO-C2", average particle size 0.5 μm, specific surface area 5.8 m ² /g) surface-treated with an amine-based alkoxysilane compound (manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573") was changed from 90 parts to 87 parts.
A resin varnish was obtained in the same manner as in Example 2 except for the above.

<Evaluation of unevenness after lamination, arithmetic mean roughness, and measurement of plating peel strength>
(1) Preparation of resin sheet A having a resin composition layer thickness of 40 μm A polyethylene terephthalate film ("AL5" manufactured by Lintec Corporation, thickness 38 μm) equipped with a release layer was prepared as a support. The resin compositions obtained in the examples and comparative examples were uniformly applied onto the release layer of this support so that the thickness of the resin composition layer after drying was 40 μm. Thereafter, the resin composition was dried at 80° C. to 100° C. (average 90° C.) for 4 minutes to obtain a resin sheet A including a support and a resin composition layer.

(2) Preparation of Inner Layer Board Both sides of a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, board thickness 0.4 mm, Panasonic Corporation "R1515A") on which an inner layer circuit was formed was etched by 1 μm with a microetching agent (Mech Corporation "CZ8101") to roughen the copper surface.

(3) Lamination of resin sheet A Using a batch type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.), the resin composition layer was laminated on both sides of the inner layer substrate so that it was in contact with the inner layer substrate. The lamination was performed by reducing the pressure for 30 seconds to adjust the air pressure to 13 hPa or less, and then pressing at 120°C and a pressure of 0.74 MPa for 30 seconds. Then, heat pressing was performed at 100°C and a pressure of 0.5 MPa for 60 seconds.

(4) Thermal curing of resin composition layer The inner layer substrate laminated with resin sheet A was then placed in an oven at 130° C. and heated for 30 minutes, and then transferred to an oven at 170° C. and heated for 30 minutes to thermally cure the resin composition layer and form an insulating layer. The support was then peeled off to obtain a cured substrate A having the insulating layer, the inner layer substrate, and the insulating layer in this order.

(5) Evaluation of Unevenness after Lamination The surface uniformity of the portions where the resin sheet A was laminated (the surfaces opposite the laminated plate) on both sides of the cured substrate A was visually observed and evaluated as follows.
◯: No unevenness was observed at all, and the surface was completely uniform.
×: Uneven areas were observed in the area where the resin sheet was laminated.

(6) Roughening Treatment A desmear treatment was performed as a roughening treatment on the cured substrate A. As the desmear treatment, the following wet desmear treatment was performed.

(Wet desmear treatment)
The cured substrate A was immersed in a swelling liquid (Atotech Japan's "Swelling Dip Securigant P", an aqueous solution of diethylene glycol monobutyl ether and sodium hydroxide) at 60° C. for 5 minutes, and then immersed in an oxidizing agent solution (Atotech Japan's "Concentrate Compact CP", an aqueous solution of potassium permanganate at about 6% and sodium hydroxide at about 4%) at 80° C. for 20 minutes. It was then immersed in a neutralizing liquid (Atotech Japan's "Reduction Solution Securigant P", an aqueous sulfuric acid solution) at 40° C. for 5 minutes, and then dried at 80° C. for 15 minutes.

(7) Measurement of arithmetic mean roughness (Ra) of insulating layer surface after roughening treatment The arithmetic mean roughness (Ra) of the insulating layer surface after roughening treatment was determined using a non-contact surface roughness meter (WYKO NT3300 manufactured by Bruker Corp.) in VSI mode with a 50x lens to obtain a measurement range of 121 μm×92 μm. The measurements were performed by calculating the average value of 10 points.

(8) Formation of Conductive Layer A conductive layer was formed on the roughened surface of the insulating layer according to the semi-additive method. That is, the substrate after the roughening treatment was immersed in an electroless plating solution containing _PdCl2 at 40 ° C for 5 minutes, and then immersed in an electroless copper plating solution at 25 ° C for 20 minutes. Next, an annealing treatment was performed by heating at 150 ° C for 30 minutes, and then an etching resist was formed and a pattern was formed by etching. Then, copper sulfate electrolytic plating was performed to form a conductive layer having a thickness of 25 μm, and an annealing treatment was performed at 190 ° C for 60 minutes. The obtained substrate is called "evaluation substrate B".

(9) Measurement of peel strength between plated conductor layer (plating peel strength) The peel strength between the insulating layer and the conductor layer was measured in accordance with the Japanese Industrial Standards (JIS C6481). Specifically, a cut was made in the conductor layer of evaluation board B, measuring 10 mm wide and 100 mm long, and one end of the cut was peeled off and held with a gripper. The load (kgf/cm) when 35 mm was peeled off in the vertical direction at a speed of 50 mm/min at room temperature was measured to determine the peel strength. A tensile tester ("AC-50C-SL" manufactured by TSE) was used for the measurement.

<Evaluation of dielectric properties>
The dielectric properties were evaluated by measuring the dielectric loss tangent (Df). Specifically, a cured product A for evaluation was prepared as follows, and the dielectric loss tangent (Df) was measured.

The resin sheet A obtained in the examples and comparative examples was cured in an oven at 190°C for 90 minutes. The support was peeled off from the resin sheet A taken out of the oven to obtain a cured resin composition layer. The cured product was cut into a length of 80 mm and a width of 2 mm to be used as cured product A for evaluation.

For each evaluation cured product A, the dielectric tangent value (Df value) was measured by the cavity resonance perturbation method using an Agilent Technologies "HP8362B" at a measurement frequency of 5.8 GHz and a measurement temperature of 23°C. Measurements were performed on two test pieces, and the average was calculated.

<Evaluation of Elongation at Break>
The elongation at break was evaluated by cutting the cured product A for evaluation into a dumbbell shape and carrying out a tensile test at a speed of 5 mm/min using an "Autograph" manufactured by Shimadzu Corporation.

<Measurement of copper foil adhesion (peel strength)>
(1) Preparation of Evaluation Substrate C As an inner layer substrate, a glass cloth-based epoxy resin double-sided copper-clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic Corporation "R1515A") having copper foil on its surface was used. Both sides of the laminate were etched with a microetching agent (Mec Corporation "CZ8101") to roughen the copper surface by 1 μm.

The resin sheet A obtained in the above-mentioned examples and comparative examples was laminated on both sides of the inner layer substrate using a batch-type vacuum pressure laminator (two-stage build-up laminator "CVP700" manufactured by Nikko Materials Co., Ltd.) so that the resin composition layer was bonded to the inner layer substrate. This lamination was performed by reducing the pressure for 30 seconds to 13 hPa or less, and then pressing at a temperature of 100°C and a pressure of 0.74 MPa for 30 seconds.

Next, the laminated resin sheet A was heat-pressed at atmospheric pressure at 100°C and a pressure of 0.5 MPa for 60 seconds to smooth it. The support was then peeled off to obtain an "intermediate laminate I" containing a resin composition layer, an inner layer substrate, and a resin composition layer in this order.

On the other hand, copper foil with a shiny surface (thickness 35 μm, Mitsui Kinzoku Co., Ltd. "3EC-III") was prepared. The shiny surface of this copper foil was roughened by etching it with a microetching agent (Mec Co., Ltd. "CZ8101") with a copper etching amount of 1 μm. The copper foil obtained in this way is called "roughened copper foil."

This roughened copper foil was laminated to both sides of intermediate laminate I so that the roughened surface of the roughened copper foil was bonded to the resin composition layer of intermediate laminate I. This lamination was performed under the same conditions as the lamination of the resin sheet to the inner layer substrate described above. In this way, an "intermediate laminate II" was obtained that contained the roughened copper foil, resin composition layer, inner layer substrate, resin composition layer, and roughened copper foil in this order.

This intermediate laminate II was placed in a 100°C oven and heated for 30 minutes, then transferred to a 170°C oven and heated for 30 minutes. Next, the intermediate laminate II was removed from the oven to room temperature and placed in a 200°C oven and heated for an additional 90 minutes. This thermally cured the resin composition layer, obtaining an "evaluation substrate C" that contained, in this order, the roughened copper foil, an insulating layer as the cured product of the resin composition layer, an inner layer substrate, an insulating layer as the cured product of the resin composition layer, and the roughened copper foil. In this evaluation substrate C, the roughened copper foil corresponds to the conductor layer.

(2) Measurement of Copper Foil Adhesion (Peel Strength) The peel strength between the roughened copper foil and the insulating layer was measured using the evaluation substrate C. This peel strength measurement was performed in accordance with JIS C6481. Specifically, the peel strength measurement was performed by the following procedure.

A cut was made in the roughened copper foil of evaluation board C, surrounding a rectangular portion 10 mm wide and 100 mm long. One end of this rectangular portion was peeled off and gripped with a gripping tool (Autocom type testing machine "AC-50C-SL" manufactured by TSE Corporation). A range of 35 mm in length of the rectangular portion was peeled off vertically, and the load (kgf/cm) at the time of peeling was measured as the peel strength. The peeling was performed at room temperature at a speed of 50 mm/min. Furthermore, the copper foil adhesion (peel strength) was measured again after the HAST test (130°C, humidity 85% RH, 100 hours).

＊表中、（Ｂ）成分の含有量は、樹脂組成物中の不揮発成分を１００質量％とした場合の含有量を表す。

*In the table, the content of component (B) represents the content when the total amount of non-volatile components in the resin composition is 100 mass %.

In Examples 1 to 10, it has been confirmed that even when component (F) is not contained, the results are similar to those of the above examples, although to a lesser extent.

Claims (10)

(A-1) liquid epoxy resin,
(A-2) a solid epoxy resin,
(B) an inorganic filler; and (C) an active ester compound having a skeleton in which a naphthalene skeleton and a biphenyl skeleton are bonded by a methylene chain ,
The component (C) has a structure represented by the following formula (C-1):
A resin composition, wherein the content of component (B) is 70 mass% or more, based on 100 mass% of non-volatile components in the resin composition .

(In formula (C-1), R ¹¹ , R ¹³ , and R ¹⁴ each independently represent an aliphatic hydrocarbon group, an alkoxy group, a halogen atom, an aryl group, or an aralkyl group; R ¹² represents a group derived from an aromatic polycarboxylic acid or an acid halide thereof; m1, m2, and m3 each independently represent 0 or an integer of 1 to 4.) The resin composition according to claim 1 , wherein the mass ratio of the component (A-1) to the component (A-2) is 1:0.1 to 1:10. The resin composition according to claim 1 or 2 , wherein the content of the component (C) is 20 mass% or less, based on 100 mass% of nonvolatile components in the resin composition. The resin composition according to any one of claims 1 to 3 , further comprising (D) a thermosetting resin. The resin composition according to any one of claims 1 to 4 , further comprising (E) a curing agent. The resin composition according to any one of claims 1 to 5 , which is used for forming an insulating layer. The resin composition according to any one of claims 1 to 6 , which is for forming an insulating layer for forming a conductor layer. A resin sheet comprising a support and a resin composition layer provided on the support, the resin composition layer comprising the resin composition according to any one of claims 1 to 7 . A printed wiring board comprising an insulating layer formed from a cured product of the resin composition according to any one of claims 1 to 7 . A semiconductor device comprising the printed wiring board according to claim 9 .