Epoxy resin, curable resin composition, cured product, and carbon fiber-reinforced composite material

Abstract

To provide an epoxy resin which is excellent in storage stability and gives a cured product excellent in flexural strength and toughness, a curable resin composition, and a cured product thereof.SOLUTION: An epoxy resin represented by the following formula (1), wherein (b + c) / a is 1% or more and less than 20% when a peak area in a case where X in the formula (1) is (1-a) is a, a peak area in a case where X in the formula (1) is (1-b) is b, and a peak area in a case where X in the formula (1) is (1-c) is c in HPLC analysis.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin suitable for carbon fiber reinforced composite materials, a curable resin composition, and a cured product obtained by curing these, as well as a carbon fiber reinforced composite material. [Background technology]

[0002] Epoxy resins, when cured with various curing agents, produce cured products with excellent mechanical properties, water resistance, chemical resistance, heat resistance, and electrical properties. These products are used in a wide range of applications, including adhesives, paints, laminates, molding compounds, and casting materials. Carbon fiber-reinforced composites (CFRPs), which are made by impregnating and curing carbon fibers with epoxy resin and a curing agent as a matrix resin, offer lightweight and high-strength properties. These composites have been widely used in recent years for aircraft structural components, wind turbine blades, automobile exterior panels, and computer applications such as IC trays and laptop computer housings, and demand for CFRP is increasing. Taking advantage of the lightweight and high-strength properties of the molded products, CFRP is particularly used as a matrix resin for aircraft applications.

[0003] Cured thermosetting resins, such as epoxy resins, used as matrix resins for CFRP and other materials are generally brittle, and require high mechanical strength when used as structural materials for aerospace applications, vehicles, etc. To compensate for the low flexural strength, toughness, adhesiveness, etc. of thermosetting resins, a widely known method is to add a highly tough thermoplastic resin to the thermosetting resin matrix (Patent Documents 1 to 3). Specifically, the flexural strength and toughness of prepregs are improved by combining particles of thermoplastic resins such as polyethersulfone, polyetherimide, and polyamide with the thermosetting resin matrix resin.

[0004] In recent years, the required properties of CFRP have become stricter, and further improvements in bending strength and toughness are required when applying it to aerospace applications and structural materials for vehicles. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 60-243113 [Patent Document 2] Japanese Patent Application Publication No. 09-100358 [Patent Document 3] Japanese Patent Application Laid-Open No. 2013-155330 [Patent Document 4] Japanese Patent Application Publication No. 04-225970 Summary of the Invention [Problem to be solved by the invention]

[0006] Japanese Patent Laid-Open No. 04-225970 (Patent Document 4) discloses N,N,N',N'-tetraglycidyl-3,3'-dialkyl-4,4'-diaminodiphenylmethane. The applicant of the present application synthesized the compound based on the description in Patent Document 4, but confirmed that although the compound is liquid immediately after synthesis, it has the problem of crystallization during storage. Therefore, before use, it is necessary to heat and dissolve the compound in a container such as a drum in an oven or hot water bath. However, since it takes a long time to dissolve, productivity is low, and the large amount of energy consumed for heating poses a problem. Furthermore, the compound returns to a solid over time after heating, making it difficult to handle.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an epoxy resin, a curable resin composition, and a cured product thereof that have excellent storage stability and that produce a cured product that has excellent flexural strength and toughness. [Means for solving the problem]

[0008] That is, the present invention is as set forth in the following [1] to [6]. In the present invention, "(Numerical value 1) to (Numerical value 2)" indicates that the upper and lower limit values ​​are included. [1] An epoxy resin represented by the following formula (1): An epoxy resin in which, when the epoxy resin is analyzed by liquid chromatography, the peak area of ​​a compound in which X in the following formula (1) is represented by the following formula (1-a) is a, the peak area of ​​a compound in which X in the following formula (1) is represented by the following formula (1-b) is b, and the peak area of ​​a compound in which X in the following formula (1) is represented by the following formula (1-c) is c, the ratio (b+c) / a is 1% or more and less than 20%.

[0009] [ka]

[0010] (In formula (1), X represents any one of formula (1-a), formula (1-b), and formula (1-c). In formula (1-b), R represents an alkyl group having 1 to 3 carbon atoms. In formulas (1-a), (1-b), and (1-c), * represents the substitution position on the nitrogen atom in formula (1).) [2] The epoxy resin according to the preceding paragraph [1], having an epoxy equivalent of 135 g / eq. or more and 165 g / eq. or less. [3] A curable resin composition comprising the epoxy resin according to the above item [1] or [2] and a curing agent. [4] The curable resin composition according to the above item [3], further containing at least one of a curing accelerator, a polymerization initiator, an epoxy resin other than the above-mentioned epoxy resin, an active ester compound, a phenol resin, a polyphenylene ether compound, an amine resin, a compound having an ethylenically unsaturated bond, an isocyanate resin, a polyamide resin, a maleimide compound, a cyanate ester resin, a polyimide resin, polybutadiene and modified products thereof, polystyrene and modified products thereof, polyethylene and modified products thereof, and a benzoxazine compound. [5] A cured product obtained by curing the curable resin composition described in the above item [3]. [6] A carbon fiber reinforced composite material obtained by curing the curable resin composition according to the above item [3]. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide an epoxy resin, a curable resin composition, and a cured product thereof that have excellent storage stability and that have excellent flexural strength and toughness. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a liquid chromatography chart of the epoxy resin of Example 1. [Figure 2] 1 is a liquid chromatography chart of the epoxy resin of Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0013] The epoxy resin of the present embodiment is represented by the following formula (1), and when analyzed by liquid chromatography, the peak area of ​​the compound in formula (1) where X is represented by formula (1-a) is a, the peak area of ​​the compound in formula (1) where X is represented by formula (1-b) is b, and the peak area of ​​the compound in formula (1) where X is represented by formula (1-c) is c, the ratio (b+c) / a is 1% or more and less than 20%. [ka]

[0014] (In formula (1), X represents any one of formula (1-a), formula (1-b), and formula (1-c). In formula (1-b), R represents an alkyl group having 1 to 3 carbon atoms. In formulas (1-a), (1-b), and (1-c), * represents the substitution position on the nitrogen atom in formula (1).)

[0015] In the formula (1-b), R represents an alkyl group having 1 to 3 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, and an isopropyl group.

[0016] (b+c) / a is usually 1% or more and less than 20%, more preferably 2% or more and less than 10%, and even more preferably 3% or more and less than 5%. When (b+c) / a is 1% or more, the resin maintains a liquid state, and the cured product has high strength and toughness. When (b+c) / a is less than 20%, the resin has good heat resistance.

[0017] In formula (1), compounds where X is represented by formula (1-a) have four crosslinking sites when cured, whereas compounds where X is represented by formula (1-b) or formula (1-c) have three crosslinking sites. Therefore, when a compound where X is represented by formula (1-a) is cured, it becomes hard and brittle, whereas when a compound where X is represented by formula (1-b) or formula (1-c) is cured, the crosslink density is lowered and elongation is improved. Therefore, when (b + c) / a is in the range of 1% or more but less than 20%, the balance between hardness and elongation is appropriate, resulting in increased strength.

[0018] The structure of the compound represented by formula (1) can be identified by liquid chromatography mass spectrometry or NMR, but it is difficult to clearly separate the compound in which X in formula (1) is formula (1-b) from the compound in which X in formula (1-c) is formula (1-c). Therefore, the peak area is determined by combining the areas of both compounds.

[0019] The liquid chromatography used to calculate the peak area was measured under the following conditions.

[0020] Liquid chromatography analysis Shimadzu Corporation Liquid Transfer Unit LC-20AD Shimadzu Corporation Photodiode array detector SPD-M20A Shimadzu Corporation Column Oven CTO-20A Column: Inertsil ODS-2, 5 μm, 4.6 × 250 mm, 40 °C MobilePhaseA: Acetonitrile (AN) Mobile Phase B: Water (W) Time Program: 0-28min.AN / W=50% / 50%→100% / 0% 28-40min.AN / W=100% / 0% Flow rate: 1.0 mL / min. Detection: UV 274nm, PDA

[0021] The epoxy equivalent of the epoxy resin of this embodiment is preferably 135 g / eq. or more and 165 g / eq. or less, and more preferably 135 g / eq. or more and less than 145 g / eq. If the epoxy equivalent is 135 g / eq. or more, the cured product will have high strength and toughness, and if it is 165 g / eq. or less, the viscosity will be low and handling will be improved.

[0022] Next, the reaction for obtaining the epoxy resin of this embodiment will be described. The epoxy resin of this embodiment can be obtained, for example, by reacting 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane with epihalohydrin.

[0023] As the starting amine, 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane, for example, Curehard MED-J (manufactured by Kumiai Chemical Industry Co., Ltd.) can be used. As the epihalohydrin, for example, epichlorohydrin, epibromohydrin, etc. can be used. The amount of epihalohydrin used is preferably 4.0 to 20 mol, more preferably 4.0 to 6.0 mol, and even more preferably 4.0 to 5.0 mol per mol of amino groups in the starting amine.

[0024] To promote the epoxidation reaction, alcohols such as methanol, ethanol, propanol, isopropanol, etc. may be added. The amount of alcohol used is preferably 20 to 100 g, more preferably 30 to 70 g, per mole of amino groups in the raw material amine.

[0025] The temperature of the epoxidation reaction is preferably 40 to 140° C., more preferably 45 to 80° C. The reaction time is preferably 0.5 to 100 hours, more preferably 3 to 30 hours, and particularly preferably 5 to 20 hours. If the reaction time is too short, the reaction will not proceed to completion, while if the reaction time is too long, by-products will be produced, which is undesirable.

[0026] In the epoxidation reaction, usable alkali metal hydroxides include sodium hydroxide, potassium hydroxide, etc., and a solid or an aqueous solution thereof may be used, but in this embodiment, a solid formed into flakes is particularly preferred from the viewpoints of solubility and handling. The amount of alkali metal hydroxide used is preferably 1.80 to 3.0 mol, more preferably 1.90 to 2.50 mol, and even more preferably 1.98 to 2.30 mol per mol of amino groups in the raw material amine.

[0027] Furthermore, to promote the epoxidation reaction, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, or trimethylbenzylammonium chloride may be added as a catalyst. The amount of the quaternary ammonium salt used is preferably 0.1 to 30 g, more preferably 0.2 to 20 g, per mole of amino groups in the raw material amine.

[0028] The temperature of the epoxidation reaction is preferably 30 to 80° C., more preferably 45 to 75° C. The reaction time is preferably 0.5 to 10 hours, more preferably 1 to 8 hours, and particularly preferably 1 to 3 hours. If the reaction time is too short, the reaction will not proceed to completion, while if the reaction time is too long, by-products will be produced, which is undesirable.

[0029] The reaction products of these epoxidation reactions are washed with water, and then the epihalohydrin and solvent are removed under reduced pressure after heating. Furthermore, to obtain an epoxy resin with a reduced hydrolyzable halogen content, the recovered epoxy resin can be dissolved in a solvent such as a ketone compound having 4 to 7 carbon atoms (e.g., methyl isobutyl ketone, methyl ethyl ketone, cyclopentanone, cyclohexanone, etc.) or a hydrocarbon compound having 4 to 8 carbon atoms (e.g., toluene, xylene, cyclohexane, etc.), and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added to the solution to carry out the reaction and ensure ring closure. In this case, the amount of alkali metal hydroxide used is typically 0.01 to 0.6 mol, preferably 0.05 to 0.4 mol, per mol of amino groups in the starting amine used in the epoxidation. The reaction temperature is typically 50 to 120°C, and the reaction time is typically 0.5 to 2 hours.

[0030] After the reaction is complete, the salt formed is removed by filtration, washing with water, or the like, and the solvent is then distilled off under heating and reduced pressure to obtain the epoxy resin of the present embodiment.

[0031] The curable resin composition of the present embodiment may contain a reactive compound in addition to the epoxy resin represented by the above formula (1). Note that the reactive compound does not include the epoxy resin represented by the above formula (1).

[0032] Examples of the reactive compound include epoxy resins other than the epoxy resin represented by formula (1), amine compounds, amide compounds, acid anhydride compounds, phenolic resins, active ester compounds, carboxylic acid compounds, maleimide compounds, cyanate compounds, isocyanate compounds, polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, polyamide compounds, polyimide compounds, allyl compounds, polybutadiene and modified products thereof, polystyrene and modified products thereof, polyethylene and modified products thereof, and benzoxazine compounds. These compounds may be used alone or in combination. Among these compounds, polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, cyanate ester resins, polybutadiene and modified products thereof, and polystyrene and modified products thereof are preferred in terms of the balance of heat resistance, adhesion, and dielectric properties. The inclusion of these compounds can improve the brittleness of the cured product and adhesion to metals, thereby suppressing package cracking during reliability tests such as solder reflow and thermal cycling. Unless otherwise specified, the total amount of the above compounds used is preferably 10 times or less by mass, more preferably 5 times or less by mass, even more preferably 3 times or less by mass, and particularly preferably 1 time or less by mass relative to the compound of this embodiment. The preferred lower limit is 0.1 times or more by mass, more preferably 0.25 times or more by mass, and even more preferably 0.5 times or more by mass. By keeping the amount within the above range, the heat resistance of the compound of this embodiment can be utilized while also enhancing the effects of each compound added. The following examples of these components can be used. Amine compounds, amide compounds, acid anhydride compounds, phenolic resins, active ester compounds, and cyanate compounds also function as curing agents for epoxy resins.

[0033] [Epoxy resins other than the epoxy resin represented by formula (1)] Preferred examples of epoxy resins other than the epoxy resin represented by the above formula (1) include, but are not limited to, the following. The epoxy resin may be liquid or solid, and may be used alone or in combination.

[0034] Examples of liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, bisphenol E type epoxy resins, bisphenol S type epoxy resins, bisphenol M type epoxy resins (4,4'-(1,3-phenylenediisopridiene)bisphenol type epoxy resins), bisphenol P type epoxy resins (4,4'-(1,4-phenylenediisopridiene)bisphenol type epoxy resins), bisphenol Z type epoxy resins (4,4'-cyclohexydiene bisphenol 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, oxazolidone ring skeleton-containing epoxy resins, and epoxy resins having a butadiene structure.Specific examples include "RE310S" and "RE410S" (all manufactured by Nippon Kayaku Co., Ltd., bisphenol A type epoxy resin), "RE303S", "RE304S", "RE403S", and "RE404S" (all manufactured by Nippon Kayaku Co., Ltd., bisphenol F type epoxy resin), "HP4032", "HP4032D", and "HP4032SS" (all manufactured by DIC Corporation, naphthalene type epoxy resin), "828US", "jER828EL", "825", and "828EL" (all manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin), "jE807", and "1750" (all manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin), "jER152" (manufactured by Mitsubishi Chemical Corporation, phenol novolac type epoxy resin), "jER604", "jER630", and "630LSD" (all manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin). Examples of epoxy resins include Mitsubishi Chemical Corporation's glycidylamine epoxy resins, "GAN" and "GOT" (all manufactured by Nippon Kayaku Co., Ltd., glycidylamine epoxy resins), "TSR-400" (DIC Corporation, oxazolidone ring-containing epoxy resin), "ZX1059" (Nippon Steel & Sumitomo Metal Chemical Co., Ltd., a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin), "EX-721" (Nagase ChemteX Corporation, glycidyl ester epoxy resin), "Celloxide 2021P" (Daicel Corporation, alicyclic epoxy resin with an ester skeleton), "PB-3600" (Daicel Corporation, epoxy resin with a butadiene structure), "ZX1658" and "ZX1658GS" (all manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., liquid 1,4-glycidylcyclohexane epoxy resin). These may be used alone or in combination of two or more.

[0035] Examples of solid epoxy resins include bixylenol-type epoxy resins, naphthol-type epoxy resins, naphthol-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, naphthylene ether-type epoxy resins, anthracene-type epoxy resins, bisphenol A-type epoxy resins, bisphenol AF-type epoxy resins, tetraphenylethane-type epoxy resins, imide skeleton-type epoxy resins, and isocyanuric-type epoxy resins. Specific examples include "HP4032H," "HP-4770" (manufactured by DIC Corporation, naphthalene-type epoxy resin), "HP-4750" (manufactured by DIC Corporation, naphthalene-type trifunctional epoxy resin), "HP-4700," and "HP-4710" (all manufactured by DIC Corporation, naphthalene-type tetrafunctional epoxy resin), "N-690" (manufactured by DIC Corporation, cresol novolac-type epoxy resin), and "N-695" (manufactured by DIC Corporation, cresol novolac-type epoxy resin). "N-655-EXP-S" (manufactured by DIC Corporation, cresol novolac type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (all manufactured by DIC Corporation, dicyclopentadiene type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP-6000" (all manufactured by DIC Corporation, naphthylene ether type epoxy resin), "EPPN-502H", FAE-2500 (all manufactured by Nippon Kayaku Co., Ltd., trisphenol type epoxy resin), "NC-7000L", "NC-7300" (all manufactured by Nippon Kayaku Co., Ltd., naphthol-cresol novolac type epoxy resin), "NC-3000H", "NC-3000", "NC-3000L", "NC-3100" (all manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl "XD-1000-2L", "XD-1000-L", "XD-1000-H" (all manufactured by Nippon Kayaku Co., Ltd., dicyclopentadiene-type epoxy resin), "WHR-991S" (imide skeleton-type epoxy resin), "ESN475V" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol-type epoxy resin), "ESN485" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., naphthol novolac-type epoxy resin), "YX-4000H","YX-4000", "YL6121" (both manufactured by Mitsubishi Chemical Corporation, biphenyl type epoxy resin), "YX-4000HK" (manufactured by Mitsubishi Chemical Corporation, bixylenol type epoxy resin), "YX-8800" (manufactured by Mitsubishi Chemical Corporation, anthracene type epoxy resin), "PG-100", "CG-500" (manufactured by Osaka Gas Chemicals Co., Ltd., fluorene type epoxy resin), "YX7760" (manufactured by Mitsubishi Chemical Corporation, bisphenol AF type epoxy resin) Examples of epoxy resins include "YL-7800" (manufactured by Mitsubishi Chemical Corporation, fluorene type epoxy resin), "jER1010" (manufactured by Mitsubishi Chemical Corporation, solid bisphenol A type epoxy resin), "jER1031S" (manufactured by Mitsubishi Chemical Corporation, tetraphenylethane type epoxy resin), CNE-195LL (manufactured by Chang Chun Plastics Co., Ltd., orthocresol novolac type epoxy resin), and "TEPIC-S" (manufactured by Nissan Chemical Industries, isocyanuric type epoxy resin). These may be used alone or in combination of two or more.

[0036] [Amine compounds] Examples of the amine compound include o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 4,4'-methylenebis(2-ethyl-6-methylaniline), 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, 2,2'-diaminodiphenylsulfone, diethyltoluenediamine, dimethylthiotoluenediamine, diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, and 3,3'-diethyl-4,4'-diaminodiphenylmethane. diphenylmethane, 4,4'-diamino-3,3'-diethyl-5,5'-dimethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetramethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetraethyldiphenylmethane, 4,4'-diamino-3,3',5,5'-tetraisopropyldiphenylmethane, 3,3'-diisopropyl-4,4'-diaminodiphenylmethane, 3,3'-di-t-butyl-4,4'-diaminodiphenylmethane, 3,3'-diisopropyl-5,5'-dimethyl-4,4'-diaminodi Phenylmethane, 3,3'-di-t-butyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-diisopropyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-di-t-butyl-5,5'-diethyl-4,4'-diaminodiphenylmethane, 3,3'-di-t-butyl-5,5'-diisopropyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetra-t-butyl-4,4'-diaminodiphenylmethane, 4,4'-methylenebis(N-methylaniline), bis(aminophenyl)phenyl Fluorene, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane, 2,2'-bis[4-(4-aminophenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 1,3'-bis(4-aminophenoxy)benzene, 1,4'-bis(4-aminophenoxy)benzene, 1,4'-bis(4-aminophenoxy)biphenyl, 4,4'-(1,3-phenylenedisopropylidene)bisaniline, 4,4'-(1,Examples of suitable amines include, but are not limited to, aromatic amine compounds such as 4-phenylenedisopropylidenebisaniline, naphthalenediamine, benzidine, dimethylbenzidine, and the aromatic amine compounds described in Synthesis Examples 1 and 2 of International Publication No. 2017 / 170551; 1,3-bis(aminomethyl)cyclohexane; isophoronediamine; 4,4'-methylenebis(cyclohexylamine); norbornanediamine; ethylenediamine (EDA); propanediamine (PDA); tetramethylenediamine (TMDA); pentamethylenediamine (PMDA); hexamethylenediamine (HMDA); diethylenetriamine (DETA); triethylenetetramine (TETA); metaxylylenediamine (MXDA); and dimer diamine. Suitable amines can be used depending on the desired properties of the composition. To ensure pot life, aromatic amines are preferred, while aliphatic amines are preferred for fast-curing properties. By using an amine compound containing a bifunctional component as the main component as a curing agent, a highly linear network can be constructed during the curing reaction, and particularly excellent toughness can be achieved.

[0037] [Amide compounds] An example of the amide compound is dicyandiamide (DICY).

[0038] [Acid anhydride compound] Examples of the acid anhydride compound include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, benzophenonetetracarboxylic acid, etc. Specific examples include "KAYAHARD MCD" (manufactured by Nippon Kayaku Co., Ltd.), "RIKACID MH-700" (manufactured by New Japan Chemical Co., Ltd., 4-methylhexahydrophthalic anhydride), "RIKACID TH" (manufactured by New Japan Chemical Co., Ltd., tetrahydrophthalic anhydride), and "RIKACID HH" (manufactured by New Japan Chemical Co., Ltd., hexahydrophthalic anhydride).

[0039] [Phenol resin] Examples of the phenolic resin include polyhydric phenols (bisphenol A, bisphenol F, bisphenol S, bisphenol M, bisphenol AD, biphenol, dihydroxynaphthalene, fluorene bisphenol, terpene diphenol, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-(1,1'-biphenyl)-4,4'-diol, dihydroxybenzene, naphthalenediol, tris-(4-hydroxyphenyl)methane, and 1,1,2,2-tetramethyl-(4-hydroxyphenyl)methane. (4-hydroxyphenyl)ethane, etc.), the above polyhydric phenols or phenols (phenol, alkyl-substituted phenol, aromatic-substituted phenol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc.) and various aldehydes (formaldehyde, acetaldehyde, alkyl aldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, etc.), or polymers of the above polyhydric phenols or the above phenols with various diene compounds (dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, disopropenylbiphenyl, butadiene, isoprene, etc.), or polycondensates of the above polyhydric phenols or the above phenols with ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, etc.). or polycondensates of the above-mentioned polyhydric phenols or the above-mentioned phenols with aromatic dimethanols (benzenedimethanol, biphenyldimethanol, etc.), or polycondensates of the above-mentioned polyhydric phenols or the above-mentioned phenols with aromatic dichloromethyls (α,α'-dichloroxylene, bischloromethylbiphenyl, etc.), or polycondensates of the above-mentioned polyhydric phenols or the above-mentioned phenols with aromatic bisalkoxymethyls (bismethoxymethylbenzene, bismethoxymethylbiphenyl, bisphenoxymethylbiphenyl, etc.).Specific examples include "MEH-7700," "MEH-7810," "MEH-7851," and "PN" (all manufactured by Meiwa Kasei Co., Ltd., phenol novolac resins), "GPH-65," and "GPH-103" (all manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl phenol resins), etc.

[0040] [Active ester compounds] The term "active ester compound" refers to a compound containing at least one ester bond in its structure, with an aliphatic chain, an aliphatic ring, or an aromatic ring bonded to both sides of the ester bond. Examples of active ester compounds include phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, which have two or more highly reactive ester groups per molecule. Active ester compounds are obtained by a condensation reaction between at least one of a carboxylic acid compound, an acid chloride, or a thiocarboxylic acid compound and at least one of a hydroxy compound or a thiol compound. From the viewpoint of improving heat resistance, active ester compounds are preferably obtained from a carboxylic acid compound or an acid chloride and a hydroxy compound, with phenol compounds or naphthol compounds being preferred as the hydroxy compound. Active ester compounds may be used singly or in combination of two or more.

[0041] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0042] Examples of the acid chloride include acetyl chloride, acrylic acid chloride, methacrylic acid chloride, malonyl chloride, succinic acid dichloride, diglycolyl chloride, glutaric acid dichloride, suberic acid dichloride, sebacic acid dichloride, adipic acid dichloride, dodecandioyl dichloride, azelaic acid chloride, 2,5-furandicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesic acid chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, and 4,4'-azodibenzoyl dichloride.

[0043] Examples of the phenol compound and naphthol compound include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalene, 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, phloroglucinol, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolak, and the phenolic resins described below. Here, the term "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one dicyclopentadiene molecule with two phenol molecules.

[0044] Preferred specific examples of the active ester compound include 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, active ester compounds containing a benzoylated product of phenol novolac, the compound described in Example 2 of WO 2020 / 095829, and the compounds disclosed in WO 2020 / 059625. Among these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadiene-type diphenol structure are more preferred. The dicyclopentadiene-type diphenol structure refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0045] Commercially available active ester compounds include, for example, "EXB9451," "EXB9460," "EXB9460S," "HPC-8000-65T," "HPC-8000H-65TM," "EXB-8000L-65TM," and "EXB-8150-65T" (manufactured by DIC Corporation) as active ester compounds containing a dicyclopentadiene-type diphenol structure; "EXB9416-70BK" (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure; "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated phenol novolac; "YLH1026," "YLH1030," and "YLH1048" (manufactured by Mitsubishi Chemical Corporation) as active ester compounds containing a benzoylated phenol novolac; "EXB-9050L-62M" (manufactured by DIC Corporation) as a phosphorus atom-containing active ester curing agent; and "Unifine" (manufactured by DIC Corporation) as an active ester compound containing a bisphenol A structure. Examples include "W-575".

[0046] [Carboxylic acid compounds] Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, 5-hydroxyisophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodiumsulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, naphthalenedicarboxylic acid, benzophenonedicarboxylic acid, furandicarboxylic acid, 4,4'-dicarboxydiphenyl ether, and 4,4'-dicarboxydiphenyl sulfide. Commercially available products include G4-142MHR (manufactured by Nippon Kayaku Co., Ltd.).

[0047] [Maleimide compounds] Examples of the maleimide compound include phenylmaleimide, 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2'-bis[4-(4-maleimidophenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 4,4'-diphenylether bismaleimide, 4,4'-diphenylsulfone bismaleimide, 1,3-bis(3-maleimidophenoxy)benzene, 1,3-bis(4-maleimidophenoxy)benzene), and Xylox-type maleimide compounds (anilix). maleimide, manufactured by Mitsui Chemicals Fine Co., Ltd.), biphenylaralkyl-type maleimide compounds (solidified by distilling off the solvent under reduced pressure from a resin solution containing the maleimide compound (M2) described in Example 4 of JP 2009-001783 A), bisaminocumylbenzene-type maleimide (maleimide compounds described in WO 2020 / 054601 A), maleimide compounds having an indane structure described in JP 6629692 A or WO 2020 / 217679 A, ​​polymaleimides derived from aromatic vinyl compounds and anilines described in JP 2023-007239 A, MATERIAL STAGE Vol. 18, No. 12 2019 "Continued Epoxy Resin CAS Number Story - Hardener CAS Number Memorandum No. 31 Bismaleimide (1)" and MATERIAL STAGE Vol. 19, No. 2 2019 Examples include the maleimide compounds described in "Continued Epoxy Resin CAS Number Story - Hardener CAS Number Memorandum No. 32, Bismaleimide (2)." Commercially available products include MIR-3000-70MT (biphenylaralkyl maleimide compound, manufactured by Nippon Kayaku Co., Ltd.) and MIZ-001 (manufactured by Nippon Kayaku Co., Ltd.).

[0048] [Cyanate compounds] Cyanate compounds are obtained by reacting phenolic compounds with cyanogen halides. Specific examples include dicyanatobenzene, tricyanatobenzene, dicyanatonaphthalene, dicyanatobiphenyl, 2,2'-bis(4-cyanatophenyl)propane, bis(4-cyanatophenyl)methane, bis(3,5-dimethyl-4-cyanatophenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanatophenyl)propane, 2,2'-bis(4-cyanatophenyl)ethane, 2,2'-bis(4-cyanatophenyl)hexafluoropropane, bis(4-cyanatophenyl)sulfone, bis(4-cyanatophenyl)thioether, phenol novolac cyanate, and phenol-dicyclopentadiene co-condensates in which the hydroxyl groups have been converted to cyanate groups. An example of a commercially available product is SYTESTER TA (bisphenol A cyanate resin, manufactured by Mitsubishi Gas Chemical Co., Ltd.). These may be used alone or in combination. Furthermore, the cyanate compound whose synthesis method is described in Japanese Patent Application Laid-Open No. 2005-264154 is particularly preferred as the cyanate compound because it has low moisture absorption, flame retardancy, and excellent dielectric properties. The cyanate compound may optionally contain a catalyst such as zinc naphthenate, cobalt naphthenate, copper naphthenate, lead naphthenate, zinc octoate, tin octoate, lead acetylacetonate, or dibutyltin maleate in order to trimerize the cyanate group to form a sym-triazine ring.

[0049] The catalyst is preferably used in an amount of 0.0001 to 0.10 parts by mass, and more preferably 0.00015 to 0.0015 parts by mass, per 100 parts by mass of the cyanate compound and curable resin composition.

[0050] [Isocyanate compounds] An isocyanate compound is a compound having two or more isocyanate groups in the molecule. Examples of the isocyanate compound include aromatic diisocyanates such as p-phenylene diisocyanate, m-phenylene diisocyanate, p-xylene diisocyanate, m-xylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and naphthalene diisocyanate; aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate, norbornene diisocyanate, and lysine diisocyanate; polyisocyanates such as one or more biuret forms of isocyanate monomers or isocyanate forms obtained by trimerizing the above-mentioned diisocyanate compounds; and polyisocyanates obtained by a urethanization reaction between the above-mentioned isocyanate compounds and polyol compounds, but are not limited to these. These may be used alone or in combination.

[0051] [Polyphenylene ether compounds] From the viewpoints of heat resistance and electrical properties, the polyphenylene ether compound is preferably a polyphenylene ether compound having an ethylenically unsaturated bond, and more preferably a polyphenylene ether compound having an acrylic group, a methacrylic group, or a styrene structure. Commercially available products include SA-9000 (manufactured by SABIC, a polyphenylene ether compound having a methacrylic group), and OPE-2St 1200 and OPE-2st 2200 (all manufactured by Mitsubishi Gas Chemical Company, polyphenylene ether compounds having a styrene structure). The number-average molecular weight (Mn) of the polyphenylene ether compound is preferably 500 to 5000, more preferably 2000 to 5000, and even more preferably 2000 to 4000. If the number-average molecular weight is less than 500, the heat resistance of the cured product tends to be insufficient. On the other hand, if the number-average molecular weight is greater than 5000, the melt viscosity increases, and sufficient fluidity cannot be obtained, which tends to result in molding defects. In addition, the reactivity decreases, the curing reaction takes a long time, and the amount of unreacted material not incorporated into the curing system increases, which tends to lower the glass transition temperature of the cured product and reduce the heat resistance of the cured product. When the number average molecular weight of the polyphenylene ether compound is 500 to 5000, it is possible to maintain excellent dielectric properties while exhibiting excellent heat resistance, moldability, etc. The number average molecular weight here can be specifically measured using gel permeation chromatography, etc.

[0052] The polyphenylene ether compound may be obtained by a polymerization reaction or by a redistribution reaction of a high-molecular-weight polyphenylene ether compound having a number-average molecular weight of approximately 10,000 to 30,000. Alternatively, these compounds may be used as raw materials and reacted with a compound having an ethylenically unsaturated bond, such as methacrylic acid chloride, acrylic acid chloride, or chloromethylstyrene, to impart radical polymerizability. A polyphenylene ether compound obtained by a redistribution reaction may be obtained, for example, by heating a high-molecular-weight polyphenylene ether compound in a solvent such as toluene in the presence of a phenolic compound and a radical initiator to cause a redistribution reaction. Such polyphenylene ether compounds obtained by a redistribution reaction are preferred because they have hydroxyl groups derived from phenolic compounds at both ends of the molecular chain that contribute to curing, thereby maintaining even higher heat resistance. Furthermore, functional groups can be introduced at both ends of the molecular chain even after modification with a compound having an ethylenically unsaturated bond. Furthermore, polyphenylene ether compounds obtained by a polymerization reaction are preferred because they exhibit excellent fluidity.

[0053] In the case of polyphenylene ether compounds obtained by polymerization, the molecular weight of the polyphenylene ether compound can be adjusted by adjusting the polymerization conditions, etc. In the case of polyphenylene ether compounds obtained by redistribution, the molecular weight of the resulting polyphenylene ether compound can be adjusted by adjusting the conditions, etc. of the redistribution reaction. More specifically, adjusting the amount of the phenolic compound used in the redistribution reaction can be considered. That is, the greater the amount of the phenolic compound, the lower the molecular weight of the resulting polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) or the like can be used as the high-molecular-weight polyphenylene ether compound that undergoes the redistribution reaction. The phenolic compound used in the redistribution reaction is not particularly limited, but preferred are, for example, polyfunctional phenolic compounds having two or more phenolic hydroxyl groups per molecule, such as bisphenol A, phenol novolac, and cresol novolac. These compounds may be used alone or in combination of two or more.

[0054] The content of the polyphenylene ether compound is not particularly limited, but is preferably 5 to 1000 parts by mass, and more preferably 10 to 750 parts by mass, relative to 100 parts by mass of the curable resin composition. When the content of the polyphenylene ether compound is within the above range, it is preferable in that a cured product not only has excellent heat resistance and the like, but also fully exhibits the excellent dielectric properties of the polyphenylene ether compound.

[0055] [Compounds containing ethylenically unsaturated bonds] A compound containing an ethylenically unsaturated bond is a compound that has one or more ethylenically unsaturated bonds in the molecule that can be polymerized by heat or light, regardless of whether a polymerization initiator is used or not. Examples of the compound containing an ethylenically unsaturated bond include acenaphthylene, indene, styrene, divinylbenzene, reaction products of the phenol resins with ethylenically unsaturated bond-containing halogen-based compounds (chloromethylstyrene, allyl chloride, methallyl chloride, acrylic acid chloride, methacrylic acid chloride, etc.), reaction products of ethylenically unsaturated bond-containing phenols (2-allylphenol, 2-propenylphenol, 4-allylphenol, 4-propenylphenol, eugenol, isoeugenol, etc.) with halogen-based compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuric chloride, etc.), reaction products of epoxy resins or alcohols with (meth)acrylic acids (acrylic acid, methacrylic acid, etc.), and acid-modified products thereof. Specific examples include, but are not limited to, STR-2000 (Zylok-type styrene resin, manufactured by Nippon Kayaku Co., Ltd.) and KAYARAD R-684. These may be used alone or in combination.

[0056] [Polyamide resin] Examples of polyamide resins include reaction products of one or more of diamines, diisocyanates, and oxazolines with dicarboxylic acids, reaction products of diamines with acid chlorides, and ring-opening polymerization products of lactam compounds. These may be used alone or in combination. Specific examples of the above raw materials are given below, but are not limited to these. <Diamine> Ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decanediamine, undecanediamine, dodecanediamine, tridecanediamine, tetradecanediamine, pentadecanediamine, hexadecanediamine, heptadecanediamine, octadecanediamine, nonadecanediamine, eicosanediamine, 2-methyl-1,5-diaminopentane, 2-methyl 1,8-diaminooctane, dimer diamine, cyclohexanediamine, bis-(4-aminocyclohexyl)methane, bis(3-methyl-4-aminocyclohexyl)methane, xylylenediamine, norbornanediamine, isophoronediamine, bisaminomethyltricyclodecane, phenylenediamine, diethyltoluenediamine, naphthalenediamine, diaminodiphenylmethane, bis(4-amino-3,5-dimethylphenyl)methane, bis(4-amino-3,5-diethylphenyl)methane aniline, 4,4'-methylenebis-o-toluidine, 4,4'-methylenebis-o-ethylaniline, 4,4'-methylenebis-2-ethyl-6-methylaniline, 4,4'-methylenebis-2,6-diisopropylaniline, 4,4-ethylenedianiline, diaminodiphenyl sulfone, diaminodiphenyl ether, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 4,4-bis(4-aminophenoxy)biphenyl, 2,2-bis[4-(4-amino 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, 9,9-bis(4-aminophenyl)fluorene, 2,7-diaminofluorene, aminobenzylamine, diaminobenzophenone, and the like. <Diisocyanate> Benzene diisocyanate, toluene diisocyanate, 1,3-bis(isocyanatomethyl)benzene, 1,3-bis(isocyanatomethyl)cyclohexane, bis(4-isocyanatophenyl)methane, isophorone diisocyanate, 1,3-bis(2-isocyanato-2-propyl)benzene, 2,2-bis(4-isocyanatophenyl)hexafluoropropane, dicyclohexylmethane-4,4'-diisocyanate, and the like. <Dicarboxylic acid> Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, terephthalic acid, isophthalic acid, 5-hydroxyisophthalic acid, 2-chloroterephthalic acid, 2-methylterephthalic acid, 5-methylisophthalic acid, 5-sodium sulfoisophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, cyclohexanedicarboxylic acid, biphenyldicarboxylic acid, naphthalenedicarboxylic acid, benzophenonedicarboxylic acid, furandicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, etc. <Acid chloride> Acetyl chloride, acrylic acid chloride, methacrylic acid chloride, malonyl chloride, succinic acid dichloride, diglycolyl chloride, glutaric acid dichloride, suberic acid dichloride, sebacic acid dichloride, adipic acid dichloride, dodecandioyl dichloride, azelaic acid chloride, 2,5-furandicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesic acid chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, 4,4'-azodibenzoyl dichloride and the like. <Lactam> ε-caprolactam, ω-undecanelactam, ω-laurolactam, and the like.

[0057] [Polyimide resin] Examples of polyimide resins include, but are not limited to, reaction products of the diamines described above with the tetracarboxylic dianhydrides listed below. These may be used alone or in combination. A specific example is LDFI089 (a polyimide compound obtained by the method described in WO2023013224A1). <Tetracarboxylic acid dianhydride> 4,4'-(Hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2dicarboxylic anhydride, pyromellitic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-diphenylsulfonetetracarboxylic dianhydride, 2,2',3, 3'-Biphenyltetracarboxylic dianhydride, methylene-4,4'-diphthalic dianhydride, 1,1-ethylidene-4,4'-diphthalic dianhydride, 2,2'-propylidene-4,4'-diphthalic dianhydride, 1,2-ethylene-4,4'-diphthalic dianhydride, 1,3-trimethylene-4,4'-diphthalic dianhydride, 1,4-tetramethylene-4,4'-diphthalic dianhydride, 1,5-pentamethylene-4,4'-diphthalic dianhydride, 4,4'-oxydiphthalic dianhydride, thio-4,4'-diphthalic dianhydride, sulfonyl-4,4'-diphthalic acid Dianhydride, 1,3-bis(3,4-dicarboxyphenyl)benzene dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,3-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, 1,4-bis[2-(3,4-dicarboxyphenyl)-2-propyl]benzene dianhydride, bis[3-(3,4-dicarboxyphenoxy)phenyl]methane dianhydride, bis[4-(3,4-dicarboxyphenoxy)phenyl]meth 2,2-bis[3-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, bis(3,4-dicarboxyphenoxy)dimethylsilane dianhydride, 1,3-bis(3,4-dicarboxyphenyl)-1,1,3,3-tetramethyldisiloxane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 3,4,9,10-Perylenetetracarboxylic dianhydride, 2,3,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, ethylenetetracarboxylic dianhydride, 1,2,3,4-butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride tetracarboxylic acid dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic acid dianhydride, carbonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, methylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,2-ethylene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 1,1-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propylidene- 4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, oxy-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, thio-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, sulfonyl-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, rel-[1S,5R,6R]-3-oxabicyclo[3,2 ,1]Octane-2,4-dione-6-spiro-3'-(tetrahydrofuran-2',5'-dione), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, ethylene glycol-bis-(3,4-dicarboxylic acid anhydride phenyl) ether, 4,4'-biphenyl bis(trimellitic acid monoester acid anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, etc.,

[0058] [Allyl compounds] Examples of the allyl compound include monoallyl isocyanurate, diallyl isocyanurate, triallyl isocyanurate, etc. Specific examples include "TAIC" (manufactured by Mitsubishi Chemical Corporation), "MA-DGIC", and "DA-MGIC" (all manufactured by Shikoku Chemical Industry Co., Ltd.).

[0059] [Polybutadiene and its modified products] Polybutadiene and its modified products are polybutadiene or compounds having a structure derived from polybutadiene in the molecule. The unsaturated bonds in the polybutadiene-derived structure may be partially or entirely converted to single bonds by hydrogenation. Examples of polybutadiene and its modified products include, but are not limited to, polybutadiene, hydroxyl-terminated polybutadiene, (meth)acrylate-terminated polybutadiene, carboxylic acid-terminated polybutadiene, amine-terminated polybutadiene, and styrene-butadiene rubber. These may be used alone or in combination. Among these, polybutadiene or styrene-butadiene rubber is preferred from the viewpoint of dielectric properties. Examples of styrene-butadiene rubber (SBR) include RICON-100, RICON-181, and RICON-184 (all manufactured by Cray Valley Corporation), and 1,2-SBS (manufactured by Nippon Soda Co., Ltd.). Examples of polybutadiene include B-1000, B-2000, and B-3000 (all manufactured by Nippon Soda Co., Ltd.). The molecular weight of polybutadiene and styrene-butadiene rubber is preferably a weight-average molecular weight of 500 to 10,000, more preferably 750 to 7,500, and even more preferably 1,000 to 5,000. Below the lower limit of the above range, the amount of evaporation is large, making it difficult to adjust the solids content during prepreg production, while above the upper limit of the above range, compatibility with other curable resins is impaired. Generally, in the case of compounds containing heteroatoms such as oxygen or nitrogen, such as bismaleimides and polymaleimides, it is difficult to ensure compatibility with low-polarity compounds, such as compounds composed mainly of hydrocarbons or compounds composed only of hydrocarbons, due to their polarity. On the other hand, the compound of this embodiment does not have a skeleton design that actively incorporates heteroatoms such as oxygen or nitrogen, and therefore has excellent compatibility with materials having low polarity and low dielectric properties, as well as compounds composed only of hydrocarbons.

[0060] [Polystyrene and its modified products] Polystyrene and its modified products are polystyrene or compounds having a structure derived from polystyrene in the molecule. Examples of polystyrene and modified products thereof include polystyrene, styrene-2-isopropenyl-2-oxazoline copolymer (Epocross RPS-1005, RP-61, both manufactured by Nippon Shokubai Co., Ltd.), SEP (styrene-ethylene-propylene copolymer: Septon (registered trademark) 1020, manufactured by Kuraray Co., Ltd.), SEPS (styrene-ethylene-propylene-styrene copolymer: Septon 2002, Septon 2004F, Septon 2005, Septon 2006, Septon 2063, Septon 2104, all manufactured by Kuraray Co., Ltd.), SEEPS (styrene-ethylene / ethylene-propylene-styrene block copolymer: Septon 4003, Septon 4044, Septon 4055, Septon 4077, Septon 4099, all manufactured by Kuraray Co., Ltd.), SEBS (styrene-ethylene-butylene-styrene copolymer: Septon 4003, Septon 4044, Septon 4055, Septon 4077, Septon 4099, all manufactured by Kuraray Co., Ltd.), Examples of suitable block copolymers include SEPTON 8004, SEPTON 8006, and SEPTON 8007L, all manufactured by Kuraray Co., Ltd.), SEEPS-OH (a styrene-ethylene / ethylene-propylene-styrene block copolymer having a hydroxyl group at its terminal: SEPTON HG252, manufactured by Kuraray Co., Ltd.), SIS (styrene-isoprene-styrene block copolymer: SEPTON 5125 and SEPTON 5127, both manufactured by Kuraray Co., Ltd.), hydrogenated SIS (hydrogenated styrene-isoprene-styrene block copolymer: HYBLER (registered trademark) 7125F and HYBLER 7311F, both manufactured by Kuraray Co., Ltd.), and SIBS (styrene-isobutylene-styrene block copolymer: SIBSTAR (registered trademark) 073T, SIBSTAR 102T, and SIBSTAR 103T (all manufactured by Kaneka Corporation), and SEPTON V9827 (manufactured by Kuraray Co., Ltd.)), but are not limited to these. These may be used alone or in combination. Polystyrene and its modified products preferably have no unsaturated bonds because they have higher heat resistance and are less susceptible to oxidative degradation. The weight-average molecular weight of polystyrene and its modified products is not particularly limited as long as it is 10,000 or more, but if it is too large, compatibility with not only polyphenylene ether compounds but also low-molecular-weight components with weight-average molecular weights of about 50 to 1,000 and oligomer components with weight-average molecular weights of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, a weight-average molecular weight of about 10,000 to 300,000 is preferred.

[0061] [Polyethylene and its modified products] Polyethylene and its modified products are polyethylene or compounds having a polyethylene-derived structure in the molecule. Examples of polyethylene and its modified products include, but are not limited to, ethylene-propylene copolymers, ethylene-styrene copolymers, ethylene-propylene-ethylidene norbornene copolymers (EBT: K-8370EM, K-9330M, etc., manufactured by Mitsui Chemicals, Inc.), ethylene-propylene-vinyl norbornene copolymers (VNB-EPT: PX-006M, PX-008M, PX-009M, etc., manufactured by Mitsui Chemicals, Inc.), ethylene-vinyl alcohol copolymers, and ethylene-vinyl acetate copolymers. From the viewpoint of improving heat resistance, it is preferable to use ethylene-propylene-ethylidene norbornene copolymers or ethylene-propylene-vinyl norbornene copolymers containing a crosslinkable structure. These may be used alone or in combination. There are no particular restrictions on the weight-average molecular weight of polyethylene and modified polyethylenes thereof as long as it is 10,000 or more. However, if it is too large, compatibility with not only polyphenylene ether compounds but also low-molecular-weight components with a weight-average molecular weight of about 50 to 1,000 and oligomer components with a weight-average molecular weight of about 1,000 to 5,000 deteriorates, making it difficult to ensure mixing and solvent stability. Therefore, it is preferably about 10,000 to 300,000.

[0062] [Benzoxazine compounds] As the benzoxazine compound, any compound may be used as long as it is a compound obtained by reacting a compound having a phenolic hydroxyl group, a compound having an amino group, or a compound having an aldehyde group. The compound having a phenolic hydroxyl group is not particularly limited, but for example, the above-mentioned phenolic resin, phenols (which may have a substituent such as an alkenyl group or an alkyl group), and bisphenols can be used. The compound having an amino group is not particularly limited, but the above-mentioned amine resin, diamine, and anilines (which may have a substituent such as an alkenyl group or an alkyl group) can be used. As the aldehyde compound, for example, the above-mentioned aldehydes can be used, but formaldehyde is preferably used. Commercially available benzoxazine compounds may be used, such as benzoxazine Pd, Fa, and ALP-d (all manufactured by Shikoku Chemical Industry Co., Ltd.), JBZ-BA100N, JBZ-FA100N, JBZ-DP100N, JBZ-OP100N, JBZ-OP100D, and JBZ-OP100I (all manufactured by JFE Chemical Corporation), and BTBz (manufactured by Japan Material Technology Co., Ltd.).

[0063] [Curing accelerator] A curing accelerator may be added to the curable resin composition of the present embodiment as needed. The curing accelerator is preferably an anionic curing accelerator that accelerates the curing reaction by generating anions upon irradiation with ultraviolet light or visible light or heating, or a cationic curing accelerator that accelerates the curing reaction by generating cations upon irradiation with ultraviolet light or visible light or heating.Examples of usable curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 1,2-dimethylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, and 2-ethyl-4-methylimidazole (2E4MZ); triethylamine; tributylamine; N,N-dimethyl-4-aminopyridine (DMAP); and 2,4,6-tris(dimethylaminomethyl)imidazole. Tertiary amines such as phenol, 2-(dimethylaminomethyl)phenol, triethylenediamine, triethanolamine, 1,8-diazabicyclo(5,4,0)undecene-7 (DBU), 1,5-diazabicyclo[4.3.0]-nonene-5 (DBN), etc.; organic phosphines such as triphenylphosphine (TPP), diphenylphosphine, tributylphosphine, tripartylphosphine, diphenylcyclohexylphosphine, tricyclohexylphosphine, etc.; trimethyl phosphite; triethylenediamine; triethanolamine; phosphonium salts such as tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium ethyltriphenylborate, ethyltriphenylphosphonium bromide, benzyltriphenylphosphonium chloride, butylphosphonium tetraphenylborate, tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, triphenylphosphinetriphenylborane, tetraphenylphosphonium thiocyanate, tetraphenylphosphonium dicyanamide, butylphenylphosphonium dicyanamide, and tetrabutylphosphonium decanoate; metal compounds such as octope Zn(2-ethylhexanoate) and stannous octoate; tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate and N-methylmorpholine tetraphenylborate; and carboxylic acid compounds such as benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, naphthoic acid, and salicylic acid.

[0064] In the curable resin composition of this embodiment, among the above-mentioned curing accelerators, it is preferable to use a phosphorus-based curing accelerator or an imidazole-based curing accelerator from the viewpoint of curability, and a phosphorus-based curing accelerator is preferable from the viewpoint of insulation reliability. The above-mentioned curing accelerators may be used alone or in combination of two or more kinds.

[0065] The curing accelerator is used in an amount of 0.01 to 15 parts by weight per 100 parts by weight of the epoxy resin, if necessary.

[0066] [Inorganic filler] Furthermore, if necessary, inorganic fillers can be added to the curable resin composition of the present embodiment.Examples of inorganic fillers include, but are not limited to, crystalline silica, fused silica, synthetic silica, hollow silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, aluminum hydroxide, magnesium hydroxide, zircon, calcium silicate, calcium carbonate, magnesium carbonate, magnesium oxide, silicon carbide, silicon nitride, 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, zirconium tungstate phosphate, clay, zirconia, fosterite, steatite, spinel, titania, talc, mica powder, zinc oxide, hydrotalcite, boehmite, carbon black, and other powders or beads obtained by sphering these. These may be used alone or in combination of two or more. The amount of these inorganic fillers used varies depending on the application, but when used as an encapsulant for semiconductors, for example, it is preferably used in an amount of 20% by weight or more in the curable resin composition from the viewpoints of heat resistance, moisture resistance, mechanical properties, flame retardancy, etc. of the cured product of the curable resin composition, more preferably 30% by weight or more, and even more preferably 70 to 95% by weight in order to improve the linear expansion coefficient with the lead frame in particular.

[0067] The curable resin composition of this embodiment can be blended with a release agent to improve release from the mold during molding. Any conventionally known release agent can be used, including ester waxes such as carnauba wax and montan wax, fatty acids such as stearic acid and palmitic acid and their metal salts, and polyolefin waxes such as oxidized polyethylene and non-oxidized polyethylene. These may be used alone or in combination. The blending amount of these release agents is preferably 0.5 to 3 wt % of the total organic components. If the amount is less than this, release from the mold is poor, and if the amount is too much, adhesion to a lead frame or the like is poor.

[0068] [Coupling agent] The curable resin composition of this embodiment can contain a coupling agent to enhance adhesion between the inorganic filler and the resin component. Any known coupling agent can be used, including, for example, vinylalkoxysilane, epoxyalkoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; styrylalkoxysilane, methacryloxyalkoxysilane, acryloxyalkoxysilane; aminoalkoxysilanes such as N-β(aminoethyl)-γ-aminopropyltrimethoxysilane; mercaptoalkoxysilanes such as γ-mercaptopropyltrimethoxysilane and γ-mercaptopropylmethyldimethoxysilane; various alkoxysilane compounds such as isocyanatoalkoxysilane; alkoxytitanium compounds; and aluminum chelates. These may be used alone or in combination. The method of adding the coupling agent may involve treating the surface of the inorganic filler with the coupling agent beforehand and then kneading it with the resin, or the coupling agent may be mixed with the resin and then the inorganic filler may be kneaded with it.

[0069] [Flame retardant] The curable resin composition of the present embodiment may contain a flame retardant. Examples of the flame retardant include halogen-based flame retardants, inorganic flame retardants (antimony compounds, metal hydroxides, nitrogen compounds, boron compounds, etc.), and phosphorus-based flame retardants. From the viewpoint of achieving halogen-free flame retardancy, phosphorus-based flame retardants are preferred.

[0070] The phosphorus-based flame retardant may be either a reactive type or an additive type. Specific examples include phosphate esters such as trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylylene phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylylene phosphate, 1,3-phenylenebis(dixylylene phosphate), 1,4-phenylenebis(dixylylene phosphate), and 4,4'-biphenyl(dixylylene phosphate); phosphanes such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide; phosphorus-containing epoxy compounds obtained by reacting epoxy resins with the active hydrogen of the phosphanes; and red phosphorus. These may be used alone or in combination. Of the above-mentioned exemplified substances, phosphate esters, phosphanes, and phosphorus-containing epoxy compounds are preferred, and 1,3-phenylenebis(dixylilenyl phosphate), 1,4-phenylenebis(dixylilenyl phosphate), 4,4'-biphenyl(dixylilenyl phosphate), and phosphorus-containing epoxy compounds are particularly preferred.

[0071] The content of the flame retardant is preferably in the range of 0.1 to 0.6 parts by mass relative to 100 parts by mass of the curable resin composition. If the content is less than 0.1 part by mass, the flame retardancy may be insufficient, and if the content is more than 0.6 part by mass, the moisture absorption and dielectric properties of the cured product may be adversely affected.

[0072] [Polymerization initiator] The curability of the curable resin composition of this embodiment can be improved by adding a polymerization initiator. The polymerization initiator is a compound capable of polymerizing an olefin functional group such as an ethylenically unsaturated bond, and examples thereof include an olefin metathesis polymerization initiator, an anionic polymerization initiator, a cationic polymerization initiator, and a radical polymerization initiator. Among these, it is preferable to use a radical polymerization initiator that has curability and appropriate stability. The radical polymerization initiator is a compound that generates radicals upon irradiation with ultraviolet or visible light or heating, thereby initiating a chain polymerization reaction. Usable radical polymerization initiators include organic peroxides, azo compounds, and benzopinacols. Organic peroxides are preferred because they are effective in controlling the curing temperature, suppress outgassing, and minimize the impact of decomposition products on electrical properties.

[0073] Examples of the organic peroxides include ketone peroxides such as methyl ethyl ketone peroxide and acetylacetone peroxide, diacyl peroxides such as benzoyl peroxide, dialkyl peroxides such as dicumyl peroxide (DCP) and 1,3-bis-(t-butylperoxyisopropyl)-benzene, peroxyketals such as t-butyl peroxybenzoate and 1,1-di-t-butylperoxycyclohexane, α-cumylperoxyneodecanoate, t-butylperoxyneodecanoate, t-butylperoxypivalate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, and t-amylperoxy-2-ethylhexanoate. Examples of suitable peroxycarbonates include alkyl peresters such as t-butyl peroxy-2-ethylhexanoate, t-amyl peroxy-3,5,5-trimethylhexanoate, t-butyl peroxy-3,5,5-trimethylhexanoate, and t-amyl peroxybenzoate; peroxycarbonates such as di-2-ethylhexyl peroxydicarbonate, bis(4-t-butylcyclohexyl)peroxydicarbonate, t-butyl peroxyisopropyl carbonate, and 1,6-bis(t-butylperoxycarbonyloxy)hexane; t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, and lauroyl peroxide. Specific examples include, but are not limited to, Irgacure OXE-04 and Irgacure 290 (both manufactured by BASF). These compounds may be used alone or in combination. Among the above organic peroxides, ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peresters, peroxycarbonates, etc. are preferred, with dialkyl peroxides being more preferred.

[0074] Examples of the azo compounds include, but are not limited to, azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2'-azobis(2,4-dimethylvaleronitrile), etc. These compounds may be used alone or in combination.

[0075] The amount of polymerization initiator added is preferably 0.01 to 5 parts by mass, and particularly preferably 0.01 to 3 parts by mass, relative to 100 parts by mass of the curable resin composition. If the amount of polymerization initiator used is less than 0.01 part by mass, the molecular weight may not be sufficiently elongated during the polymerization reaction, and if it is more than 5 parts by mass, the dielectric properties such as the dielectric constant and dielectric loss tangent may be impaired.

[0076] [Polymerization inhibitor] The curable resin composition of this embodiment may contain a polymerization inhibitor. The inclusion of a polymerization inhibitor improves storage stability and enables control of the reaction initiation temperature. Controlling the reaction initiation temperature makes it easier to ensure fluidity, prevents impregnation into glass cloth and the like from being impaired, and facilitates B-staging, such as prepreg formation. If the polymerization reaction proceeds too much during prepreg formation, problems such as difficulty in lamination during the lamination process are likely to occur.

[0077] The polymerization inhibitor may be added during or after the synthesis of the compound of this embodiment. The amount of the polymerization inhibitor used is 0.008 to 1 part by weight, preferably 0.01 to 0.5 parts by weight, based on 100 parts by weight of the compound of this embodiment.

[0078] Examples of the polymerization inhibitor include phenol-based, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, and nitroxyl radical-based. One type of polymerization inhibitor may be used alone, or multiple types may be used in combination. Among these, in this embodiment, phenol-based, hindered amine-based, nitroso-based, and nitroxyl radical-based inhibitors are preferred.

[0079] Examples of the phenolic polymerization inhibitor include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,4-bis-(n-octylthio)-6-(4-hydroxy-3,5-di-t-butylanilino)-1,3,5-triazine, 2,4-bis[(octylthio)methyl]-o ...butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyanisole, butylated hydroxyani Monophenols such as resol, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 2,2'-methylenebis(4-ethyl-6-t-butylphenol), 4,4'-thiobis(3-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] N,N'-Hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 3,9-bis[1,1-dimethyl-2-{β-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}ethyl]2,4,8,10-tetraoxaspiro[5,5]undecane, bis(3,5-di-t-butyl Bisphenols such as calcium ethyl-4-hydroxybenzylsulfonate, 1,1,3-tris(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl)propionate]methane, bis[3,3'-bis-(4'-hydroxy-3'-t-butylphenyl)butyric acid]glycol ester, tris-(3,Examples of the polymerizable phenols include, but are not limited to, 5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,3,5-tris(3',5'-di-t-butyl-4'-hydroxybenzyl)-S-triazine-2,4,6-(1H,3H,5H)trione, and tocopherol.

[0080] Examples of the sulfur-based polymerization inhibitor include, but are not limited to, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0081] Examples of the phosphorus-based polymerization inhibitor include triphenyl phosphite, diphenyl isodecyl phosphite, phenyl diisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecyl pentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentane tetrayl bis(octadecyl) phosphite, cyclic neopentane tetrayl bis(2,4-di-t-butylphenyl) phosphite, cyclic neopentane tetrayl bis(2,4-di-t-butyl-4-methylphenyl) phosphite, bis[2- Examples of suitable phosphites include t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite, and oxaphosphaphenanthrene oxides such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, but are not limited to these.

[0082] Examples of the hindered amine polymerization inhibitor include ADK STAB (registered trademark) LA-40MP, ADK STAB LA-40Si, ADK STAB LA-402AF, ADK STAB LA-87, ADK STAB LA-82, ADK STAB LA-81, ADK STAB LA-77Y, ADK STAB LA-77G, ADK STAB LA-72, ADK STAB LA-68, ADK STAB LA-63P, ADK STAB LA-57, and ADK STAB LA-52 (all manufactured by ADK STAB Corporation). Examples of suitable ethylene glycol acrylate crosspolymers include, but are not limited to, ethylene glycol acrylate crosspolymers manufactured by BASF, Chimassorb (registered trademark) 2020FDL, Chimassorb 944FDL, Chimassorb 944LD, Tinuvin (registered trademark) 622SF, Tinuvin PA144, Tinuvin 765, Tinuvin 770DF, Tinuvin XT55FB, Tinuvin 111FDL, Tinuvin 783FDL, and Tinuvin 791FB (all manufactured by BASF).

[0083] Examples of the nitroso-based polymerization inhibitor include, but are not limited to, p-nitrosophenol, N-nitrosodiphenylamine, and the ammonium salt (cupferron) of N-nitrosophenylhydroxyamine. Of these, the ammonium salt (cupferron) of N-nitrosophenylhydroxyamine is preferred.

[0084] Examples of the nitroxyl radical polymerization inhibitor include di-tert-butyl nitroxide, 2,2,6,6-tetramethylpiperidine-1-oxyl, 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, 4-acetoxy-2,2,6,6-tetramethylpiperidine-1-oxyl, and 4-benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl, but are not limited to these.

[0085] [Light stabilizer] The curable resin composition of this embodiment may contain a light stabilizer, and preferred examples of the light stabilizer include hindered amine light stabilizers (HALS). Examples of HALS include reaction products of dibutylamine, 1,3,5-triazine, N,N'-bis(2,2,6,6-tetramethyl-4-piperidyl-1,6-hexamethylenediamine and N-(2,2,6,6-tetramethyl-4-piperidyl)butylamine, reaction products of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene{(2,2,6,6-tetramethyl-4-piperidyl)imino}], bis(1,2 ,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, bis(2,2,6,6-tetramethyl-4-piperidyl)sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl)sebacate, bis(1-octyloxy-2,2,6,6-tetramethyl-4-piperidyl)sebacate, 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonate bis(1,2,2,6,6-pentamethyl-4-piperidyl), etc., but are not limited thereto. These may be used alone or in combination.

[0086] The content of the light stabilizer is preferably in the range of 0.001 to 0.1 parts by mass relative to 100 parts by mass of the curable resin composition. If the content is less than 0.001 part by mass, the light stabilizing effect may be insufficient, and if the content is more than 0.1 part by mass, the moisture absorption and dielectric properties of the cured product may be adversely affected.

[0087] [Binder resin] The curable resin composition of this embodiment may contain a binder resin. Examples of binder resins include, but are not limited to, butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenol resins, epoxy-NBR resins, and silicone resins. These may be used alone or in combination.

[0088] The amount of binder resin to be added is preferably within a range that does not impair the flame retardancy and heat resistance of the cured product, and is preferably 0.05 to 50 parts by mass, and more preferably 0.05 to 20 parts by mass, per 100 parts by mass of the curable resin composition, as needed.

[0089] Furthermore, the curable resin composition of the present embodiment may contain known additives as needed, such as polybutadiene and modified polybutadiene, modified acrylonitrile copolymers, polystyrene, polyethylene, fluororesin, silicone gel, silicone oil, and colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

[0090] The amount of the additives to be added is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less, per 100 parts by mass of the curable resin composition.

[0091] The curable resin composition of this embodiment can be obtained by preparing the above components in a predetermined ratio, pre-curing the composition at 130 to 180°C for 30 to 500 seconds, and then post-curing the composition at 150 to 200°C for 2 to 15 hours, thereby allowing the curing reaction to proceed sufficiently and producing the cured product of this embodiment. Alternatively, the components of the curable resin composition can be uniformly dispersed or dissolved in a solvent or the like, and the solvent can be removed before curing.

[0092] The method for preparing the curable resin composition of this embodiment is not particularly limited, and the components may be simply mixed uniformly, or may be prepolymerized. For example, a mixture containing the compound of this embodiment is heated in the presence or absence of a curing accelerator or a polymerization initiator, and in the presence or absence of a solvent, to form a prepolymer. Similarly, compounds such as amine compounds, compounds having ethylenically unsaturated bonds, maleimide compounds, cyanate ester compounds, polybutadiene and its modified products, polystyrene and its modified products, inorganic fillers, and other additives may be added to form a prepolymer. The components may be mixed or prepolymerized using, for example, an extruder, kneader, or rolls in the absence of a solvent, or a reaction kettle equipped with a stirrer in the presence of a solvent.

[0093] To achieve uniform mixing, the materials are kneaded at a temperature in the range of 50 to 100°C using a device such as a kneader, roll, or planetary mixer to obtain a uniform resin composition. The resulting resin composition is then pulverized and molded into cylindrical tablets using a molding machine such as a tablet machine, or into granular powder or powder-like molded products. Alternatively, these compositions can be melted on a surface support and molded into a sheet with a thickness of 0.05 mm to 10 mm to obtain a molded curable resin composition. The resulting molded product is non-sticky at 0 to 20°C, and exhibits little loss of fluidity or curability even when stored at -25 to 0°C for one week or more. The resulting molded article can be molded into a cured product using a transfer molding machine or a compression molding machine.

[0094] Depending on the molding method, the obtained curable resin composition can be in various forms such as a resin sheet, a prepreg, etc. A prepreg form can be obtained, for example, by heating and melting the curable resin composition and / or a resin sheet of the present embodiment to reduce the viscosity and impregnating the composition into a fiber substrate.

[0095] The curable resin composition of this embodiment can be dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethylformamide, dimethylacetamide, or N-methylpyrrolidone, as needed, to form a varnish-like composition (hereinafter simply referred to as a varnish), which can then be impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, or paper, and dried by heating to form a prepreg. In this case, the solvent is used in an amount that accounts for 10 to 70 wt %, preferably 15 to 70 wt %, of the mixture of the curable resin composition of this embodiment and the solvent.

[0096] The prepreg is cut into a desired shape and laminated, and then the epoxy resin composition is heat-cured while applying pressure to the laminate using a press molding method, autoclave molding method, sheet winding molding method, etc., to obtain a carbon fiber reinforced plastic (CFRP). Copper foil or an organic film can also be laminated during the lamination of the prepreg.

[0097] In addition to the above-mentioned methods, CFRP can also be obtained by molding using known methods. For example, resin transfer molding (RTM) can be used, in which a carbon fiber substrate (usually a carbon fiber fabric) is cut, laminated, and shaped to produce a preform (a preform before being impregnated with resin). The preform is then placed in a mold, the mold is closed, resin is injected into the preform, the resin is impregnated, and cured, and the mold is opened to remove the molded product. Also usable are types of RTM, such as the VaRTM method, the SCRIMP (Seeman's Composite Resin Infusion Molding Process) method, and the CAPRI (Controlled Atmospheric Pressure Resin Infusion) method, which is described in JP 2005-527410 and which more appropriately controls the resin injection process, particularly the VaRTM method, by evacuating a resin supply tank to a pressure lower than atmospheric pressure, using cyclic compression, and controlling the net molding pressure. Other methods that can be used include the film stacking method, in which a fiber substrate is sandwiched between resin sheets (films), a method in which powder resin is attached to a reinforced fiber substrate to improve impregnation, a molding method that uses a fluidized bed or fluid slurry method in the process of mixing resin into the fiber substrate (Powder Impregnated Yarn), and a method in which resin fibers are mixed into the fiber substrate.

[0098] Examples of carbon fibers include acrylic, pitch, and rayon carbon fibers, and among these, acrylic carbon fibers, which have high tensile strength, are preferably used. The carbon fiber may be in the form of twisted yarn, untwisted yarn, or non-twisted yarn, but untwisted yarn or non-twisted yarn is preferred because it provides a good balance between the formability and strength properties of the fiber-reinforced composite material.

[0099] The cured product of the curable resin composition of the present embodiment can be used for various applications other than the above-mentioned applications such as CFRP, and examples thereof include adhesives, paints, coating agents, molding materials (including sheets, films, CFRP, etc.), encapsulants for semiconductor elements, encapsulants for liquid crystal display elements, encapsulants for organic EL elements, electrical and electronic parts such as printed wiring boards (BGA substrates, build-up substrates, etc.), 3D printing, and additives for other resins, etc.

[0100] Examples of the adhesives include adhesives for civil engineering, construction, automobiles, general office use, and medical use, as well as adhesives for electronic materials. Among these, adhesives for electronic materials include interlayer adhesives for multilayer substrates such as build-up substrates, die bonding agents, semiconductor adhesives such as underfills, underfills for reinforcing BGAs, and mounting adhesives such as anisotropic conductive films (ACFs) and anisotropic conductive pastes (ACPs), and are applicable to a variety of uses.

[0101] When the curable resin composition of this embodiment is applied to an encapsulant for semiconductor elements, a lead frame equipped with a semiconductor element or a semiconductor package substrate is placed in a mold, and the curable resin composition of this embodiment is molded by a melt casting method, transfer molding method, injection molding method, compression molding method, or the like, and further heated at 80 to 200°C for 2 to 10 hours to obtain a cured product. Examples of semiconductor devices manufactured using this encapsulant include potting, dipping, and transfer mold encapsulation for capacitors, transistors, diodes, light-emitting diodes, ICs, and LSIs; potting encapsulation for COB, COF, TAB, and the like for ICs and LSIs; underfill for flip chips; and encapsulation (including reinforcing underfill) for mounting IC packages such as QFP, BGA, and CSP.

[0102] When the curable resin composition of this embodiment is applied to printed wiring boards, it can be heated and melted to reduce viscosity, and then impregnated into reinforcing fibers such as glass fibers and polyamide fibers to obtain a prepreg. Specific examples include, but are not limited to, glass fibers such as E-glass cloth, D-glass cloth, S-glass cloth, Q-glass cloth, spherical glass cloth, NE-glass cloth, and T-glass cloth, and / or organic fibers. The shape of the substrate is not particularly limited, but examples include woven fabrics, nonwoven fabrics, rovings, and chopped strand mats. Known weaving methods for woven fabrics include plain weave, sieve weave, and twill weave, and these known methods can be appropriately selected depending on the intended application and performance. Furthermore, woven fabrics that have been subjected to fiber opening treatment or glass woven fabrics that have been surface-treated with a silane coupling agent or the like are preferably used. The thickness of the substrate is not particularly limited, but is preferably about 0.01 to 0.4 mm. Furthermore, a prepreg can be obtained by impregnating reinforcing fibers with the varnish and drying them under heat, and a copper clad laminate (CCL) can be produced from this. A laminate can also be produced using the curable resin composition of this embodiment by hot-press molding the obtained prepreg and CCL. The laminate is not particularly limited as long as it includes one or more prepregs, and may also include any other layers. Furthermore, a sheet-like adhesive can be obtained by applying the varnish to a release film, removing the solvent under heat, and B-staging the varnish. This sheet-like adhesive can be used as an interlayer insulating layer in a multilayer substrate or as an adhesive sheet for mounting semiconductors. The curable resin composition of this embodiment can also be suitably used for special substrate materials such as package substrates and high-density interconnects (HDIs). [Example]

[0103] The present embodiment will be described in more detail below with reference to synthesis examples and working examples. The materials, processing details, processing procedures, etc. shown below can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be construed as being limited by the specific examples shown below. The various analytical methods used in the examples are described below.

[0104] The analysis was carried out under the following conditions. Epoxy equivalent It is measured according to the method described in JIS K-7236, and the unit is g / eq. Liquid chromatography analysis Shimadzu Corporation Liquid Transfer Unit LC-20AD Shimadzu Corporation Photodiode array detector SPD-M20A Shimadzu Corporation Column Oven CTO-20A Column: Inertsil ODS-2, 5 μm, 4.6 × 250 mm, 40 °C MobilePhaseA: Acetonitrile (AN) Mobile Phase B: Water (W) Time Program: 0-28min.AN / W=50% / 50%→100% / 0% 28-40min.AN / W=100% / 0% Flow rate: 1.0 mL / min. Detection: UV 274nm, PDA

[0105] [Example 1] A flask equipped with a thermometer, a condenser, and a stirrer was purged with nitrogen. 119 parts by weight of 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane (product name: Curehard MED-J, manufactured by Kumiai Chemical Industry Co., Ltd.) was charged with 466 parts by weight of epichlorohydrin, 47 parts by weight of methanol, and 14 parts by weight of water. The mixture was heated to 45°C with stirring and reacted for 2 hours, then heated to 55°C and reacted for 4 hours, then heated to 65°C and reacted for 4 hours, and finally heated to 80°C and reacted for 14 hours. The temperature was then lowered to 70°C, and 89 parts by weight of flaky sodium hydroxide was added in portions over 90 minutes. The mixture was further reacted at 70°C for 1 hour. 262 parts by weight of water was then added to wash the mixture. Excess epichlorohydrin was then removed from the oil layer using an evaporator heated to 130°C under reduced pressure. The residue was dissolved with 367 parts by weight of toluene, and 24 parts by weight of a 30% aqueous sodium hydroxide solution was added at 75°C, followed by a reaction for 1 hour. After the reaction, the mixture was washed with water three times to remove purified salts and other impurities. The toluene was distilled off under reduced pressure at 140°C, yielding 180 parts by weight of the epoxy resin (A) of the present invention represented by formula (1). The resulting epoxy resin was liquid at room temperature and had an epoxy equivalent of 137 g / eq. A liquid chromatography chart of the resulting epoxy resin is shown in Figure 1. In Figure 1, the peak peak for the compound in which X in formula (1) is formula (1-a) was 22.2 minutes, and the peak peak peak for the compound in which X is formula (1-b) or formula (1-c) was 21.2 to 21.4 minutes, with a (b + c) / a ratio of 3.5%.

[0106] [Comparative Example 1] The synthesis was carried out according to the description in paragraph 0028 of JP-A-04-225970. A flask equipped with a thermometer, condenser, and stirrer was purged with nitrogen and charged with 119 parts by weight of 3,3'-diethyl-5,5'-dimethyl-4,4'-diaminodiphenylmethane (product name: Curehard MED-J, manufactured by Kumiai Chemical Industry Co., Ltd.) and 544 parts by weight of epichlorohydrin. The mixture was heated to 100°C and stirred for 2 hours. The mixture was then cooled to 50°C, and 2 parts by weight of a 50% aqueous solution of tetramethylammonium chloride and 6 parts by weight of sodium bicarbonate were added. While reducing the pressure inside the flask using a vacuum pump, 138 parts by weight of a 50% aqueous solution of sodium hydroxide was added dropwise over 5 hours. The distilled water was removed from the reaction system, and the epichlorohydrin was returned to the flask. After the addition was completed, the mixture was allowed to react for 30 minutes and then cooled to 35°C. 295 parts by weight of water was added and the mixture was washed with water. Excess epichlorohydrin was removed from the oil layer using an evaporator under reduced pressure at 130°C, yielding 185 parts by weight of epoxy resin (A). The resulting epoxy resin was liquid at room temperature and had an epoxy equivalent of 132 g / eq. A liquid chromatography chart of the resulting epoxy resin is shown in Figure 2. In Figure 2, the peak peak for the compound in which X in formula (1) is formula (1-a) was 22.2 minutes, and for the compound in which X is formula (1-b) or formula (1-c) was 21.2 to 21.4 minutes, with (b + c) / a being 0.5%.

[0107] [Example 2, Comparative Example 2] <Crystallization test> The liquid epoxy resins obtained in Example 1 and Comparative Example 1 were stored at 20°C for 7 days, and then visually inspected for the presence or absence of crystal precipitation. If the liquid state was maintained, it was marked with a circle, and if crystals were observed, it was marked with an X. The results are shown in Table 1.

[0108] [Table 1]

[0109] The results in Table 1 confirm that the epoxy resins of the present invention have excellent storage stability. After storing the epoxy resin of Comparative Example 1 at 20°C for 7 days, crystals were observed and the resin lost its fluidity. It was confirmed that these crystals melt when heated to 100°C or higher.

[0110] [Example 3, Comparative Example 3] The epoxy resins obtained in Example 1 and Comparative Example 1 were mixed with 4,4'-diaminodiphenyl sulfone (abbreviated as DDS) as a curing agent in the proportions (parts by weight) shown in Table 1, and cured at 180°C for 6 hours to produce a cured product. The physical properties were then evaluated. The results are shown in Table 2.

[0111] The physical properties were measured under the following conditions. <Measurement conditions for bending strength, bending modulus, and bending elongation at break> Measured according to JIS K-7074. <Heat resistance (Tg) measurement conditions> Dynamic viscoelasticity measuring instrument: TA-instruments, DMA-2980 Measurement temperature range: -30 to 280°C Heating rate: 2°C / min Tg: The temperature at which the elastic modulus begins to decrease was taken as Tg.

[0112] [Table 2]

[0113] From the results in Table 2, it was confirmed that Example 3, which used the epoxy resin of the present invention, was excellent in flexural strength and elongation. <Curing test> [Reference example 1] 5 parts of the epoxy resin obtained in Example 1, 20 parts of NC-3000 (manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl type epoxy resin), 0.5 parts of 4,4'-methylenebis(2-ethyl-6-methylaniline) (manufactured by Tokyo Chemical Industry Co., Ltd., amine compound), 1 part of DICY: dicyandiamide (manufactured by Tokyo Chemical Industry Co., Ltd., amide compound), 0.5 parts of KAYAHARD MCD (manufactured by Nippon Kayaku Co., Ltd., acid anhydride compound), KAYAHARD 0.5 parts of GPH-65 (Nippon Kayaku Co., Ltd., biphenylaralkyl type phenol resin), 0.5 parts of Unifiner W-575 (Unitika Ltd., activated ester resin), 0.5 parts of G4-142MHR (Nippon Kayaku Co., Ltd., carboxylic acid compound), 2.5 parts of MIR-3000-70MT (Nippon Kayaku Co., Ltd., maleimide compound), 2.5 parts of MIZ-001 (Nippon Kayaku Co., Ltd., maleimide compound), 0.5 parts of phenylmaleimide (Tokyo Chemical Industry Co., Ltd., maleimide compound), 0.5 parts of SYTESTER TA (Mitsubishi Gas Chemical Co., Ltd., bisphenol A type cyanate resin), 60 parts of OPE-2st 2200 (Mitsubishi Gas Chemical Co., Ltd., polyphenylene ether compound), 3 parts of the compound described in Example 10 of Japanese Patent No. 6,951,829 (compound having an ethylenically unsaturated bond), KAYARAD R-684 (manufactured by Nippon Kayaku Co., Ltd., compound having an ethylenically unsaturated bond) 1 part, acenaphthylene (manufactured by Tokyo Chemical Industry Co., Ltd., compound having an ethylenically unsaturated bond) 0.5 parts, 1 part of a polyimide compound obtained by the method described in WO2023 / 013224A1, TAIC: triallyl isocyanurate (manufactured by Mitsubishi Chemical Corporation, allyl compound) 1 part, Septon 2104 (manufactured by Kuraray Co., Ltd., modified polystyrene) 1 part, Pd-type benzoxazine (manufactured by Shikoku Chemical Industry Co., Ltd., benzoxazine compound) 1 part, 2E4MZ: 2-ethyl-4-methylimidazole (manufactured by Shikoku Chemical Industry Co., Ltd., curing accelerator) 0.5 parts, TPP: triphenylphosphine (manufactured by Hokko Chemical Industry Co., Ltd., curing accelerator) 0.5 parts, Octope Zn (manufactured by Hope Pharmaceutical Co., Ltd., curing accelerator) 0.1 parts, San-Aid 0.1 parts of SI-B5 (Sanshin Chemical Co., Ltd., curing accelerator), 1 part of DCP: dicumyl peroxide (Kayaku Nouryon Co., Ltd., polymerization initiator), 99.2 parts of toluene as a solvent, 49.The mixture was mixed at a ratio of 6 parts and heated at 110°C for 10 minutes and then at 220°C for 1 hour in a nitrogen atmosphere to obtain a cured product.

[0114] [Reference example 2] Five parts of the epoxy resin obtained in Example 1, 50 parts of NC-3000 (a biphenylaralkyl epoxy resin manufactured by Nippon Kayaku Co., Ltd.), 10 parts of MIZ-001 (a maleimide compound manufactured by Nippon Kayaku Co., Ltd.), 5 parts of the compound described in Example 10 of Japanese Patent No. 6951829 (a compound having an ethylenically unsaturated bond), 45 parts of KAYARAD R-684 (a compound having an ethylenically unsaturated bond manufactured by Nippon Kayaku Co., Ltd.), 1 part of Irgacure OXE-04 (a polymerization initiator manufactured by BASF), and 1 part of Irgacure 290 (a polymerization initiator manufactured by BASF) were mixed and applied to a PET film to a film thickness of 100 μm. A PET film was also attached to the side not in contact with the film, and the mixture was irradiated with 3000 mJ / cm using a high-pressure mercury lamp (365 nm). 2 A cured product was obtained by irradiating the composition with ultraviolet light.

Claims

1. An epoxy resin represented by the following formula (1): When the epoxy resin is analyzed by liquid chromatography, the peak area of ​​a compound in which X in formula (1) is represented by the following formula (1-a) is defined as a, the peak area of ​​a compound in which X in formula (1) is represented by the following formula (1-b) is defined as b, and the peak area of ​​a compound in which X in formula (1) is represented by the following formula (1-c) is defined as c, where (b+c) / a is 1% or more and less than 20%. 【Chemistry 1】 (In formula (1), X represents any one of formula (1-a), formula (1-b), and formula (1-c). In formula (1-b), R represents an alkyl group having 1 to 3 carbon atoms. In formulas (1-a), (1-b), and (1-c), * represents the substitution position on the nitrogen atom in formula (1).)

2. 2. The epoxy resin according to claim 1, having an epoxy equivalent of 135 g / eq. or more and 165 g / eq. or less.

3. A curable resin composition comprising the epoxy resin according to claim 1 or 2 and a curing agent.

4. The curable resin composition according to claim 3, further comprising at least one selected from the group consisting of a curing accelerator, a polymerization initiator, an epoxy resin other than the epoxy resin, an active ester compound, a phenol resin, a polyphenylene ether compound, an amine resin, a compound having an ethylenically unsaturated bond, an isocyanate resin, a polyamide resin, a maleimide compound, a cyanate ester resin, a polyimide resin, polybutadiene and modified products thereof, polystyrene and modified products thereof, polyethylene and modified products thereof, and a benzoxazine compound.

5. A cured product obtained by curing the curable resin composition according to claim 3.

6. A carbon fiber reinforced composite material obtained by curing the curable resin composition according to claim 3.