Curable resin composition and cured product thereof

Abstract

The present invention provides: a curable resin composition having excellent adhesion to a copper foil, low hygroscopicity, low dielectric characteristics, and oxidation deterioration resistance; and a cured product thereof.　The curable resin composition contains: a maleimide resin having a maleimide equivalent of 730 g / eq or less, and having at least one structure represented by formula (1) in a molecule; and a copolymer including ethylene, styrene and divinylbenzene. (In formula (1), Al is a C1-C60 aliphatic hydrocarbon group.)

Description

Curable resin composition and its cured product

[0001] The present invention relates to a curable resin composition and its cured product, and is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, and optical waveguide devices, as well as lightweight, high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and in 3D printing applications.

[0002] In recent years, the required characteristics of laminates on which electrical and electronic components are mounted have become broader and more sophisticated due to the expansion of their application fields. While conventional semiconductor chips were mainly mounted on metal lead frames, high-performance semiconductor chips such as central processing units (hereinafter referred to as CPUs) are increasingly being mounted on laminates made of polymer materials.

[0003] The fifth-generation communication system, "5G," aims for even greater capacity and higher speed communication. While 5G will utilize higher frequencies, reducing transmission loss is crucial for achieving high-speed communication using high frequencies, thus requiring substrate materials with even lower dielectric properties. Transmission loss on printed circuit boards originates from both conductor loss and dielectric loss. As described in Non-Patent Literature 1, conductor loss is proportional to the square root of the dielectric constant and the dielectric loss tangent. Therefore, improving the dielectric loss tangent, which contributes more significantly than the dielectric constant, is effective in reducing transmission loss. Materials with low dielectric loss tangent include thermoplastic materials such as PTFE (polytetrafluoroethylene), LCP (liquid crystal polymer), and rubber materials, but they have poor moldability compared to thermosetting resins. Therefore, the development of thermosetting resins or compositions containing thermosetting resins with excellent low dielectric properties is desired.

[0004] Signal Loss Factors in High-Speed ​​Signal Transmission on Printed Circuit Boards (Mitsui Mining & Smelting Co., Ltd.) 29th Spring Conference of the Japan Society for Electronics Packaging 16P1-17

[0005] Japanese Patent Publication No. 2025-001720

[0006] Thermosetting resins and compositions containing thermosetting resins that exhibit excellent low dielectric properties include resins composed solely of carbon and hydrogen, and compositions using the same. However, when exposed to high temperatures in the atmosphere, they may oxidize and generate polar groups, potentially leading to a significant deterioration of their dielectric properties. Patent Document 1 proposes a composition of a maleimide compound and an aromatic vinylbenzyl compound, which exhibits excellent resistance to oxidative degradation, but its dielectric properties are not considered sufficient.

[0007] This invention has been made in view of the above circumstances, and aims to provide a curable resin composition and a cured product thereof that have low dielectric properties and resistance to oxidative degradation.

[0008] In other words, the present invention relates to a curable resin composition containing a maleimide resin having a maleimide equivalent of 730 g / eq. or less and having at least one structure represented by the following formula (1) in its molecule, and a copolymer containing ethylene, styrene, and divinylbenzene.

[0009]

[0010] (In formula (1), Al is an aliphatic hydrocarbon group having 1 to 60 carbon atoms.)

[0011] In this application, "(numerical value 1) to (numerical value 2)" indicates that the upper and lower limits are included.

[0012] According to the present invention, it is possible to provide a curable resin composition and a cured product thereof that have low dielectric properties and resistance to oxidative degradation.

[0013] The GPC chart for synthesis example 1 is shown. The GPC chart for synthesis example 2 is shown. The GPC chart for synthesis example 3 is shown. The GPC chart for synthesis example 4 is shown. The GPC chart for synthesis example 5 is shown.

[0014] The embodiments of the present invention (hereinafter also referred to as "this embodiment") will be described in more detail below.

[0015] The curable resin composition of this embodiment contains a maleimide resin (hereinafter also referred to as the maleimide resin of this embodiment) having a maleimide equivalent of 730 g / eq. or less and having at least one structure represented by the following formula (1) in its molecule, and a copolymer containing ethylene, styrene, and divinylbenzene (hereinafter also referred to as the copolymer of this embodiment).

[0016]

[0017] In formula (1), Al is an aliphatic hydrocarbon group having 1 to 60 carbon atoms, preferably 2 to 50 carbon atoms, and more preferably 3 to 40 carbon atoms. Examples of aliphatic hydrocarbon groups include linear, branched, cyclic, and heteroatom-containing structures. The aliphatic hydrocarbon group is preferably divalent or higher.

[0018] The maleimide resin of this embodiment is not particularly limited as long as it has at least one structure represented by the above formula (1) in its molecule and its maleimide equivalent is 730 g / eq. or less. Here, the maleimide equivalent is the mass of a compound containing one equivalent of maleimide groups. For example, if a maleimide resin with a molecular weight of 730 has one maleimide group attached, the functional group equivalent will be 730 g / eq. The maleimide equivalent can be measured, for example, by the measurement method described in Japanese Patent Application Publication No. 2020-187012. Alternatively, if the maleimide equivalent can be calculated from the structural formula and the number of functional groups, that value may be used. It is preferable to have two or more maleimide groups in the molecule, and these may be used individually or in combination of multiple types.

[0019] The maleimide equivalent of the maleimide resin in this embodiment is preferably 100 g / eq. to 730 g / eq., more preferably 140 g / eq. to 730 g / eq., even more preferably 200 g / eq. to 730 g / eq., even more preferably 300 g / eq. to 720 g / eq., and particularly preferably 310 g / eq. to 720 g / eq. If it is smaller than the above range, the functional group concentration of the maleimide group will be high, resulting in poor compatibility with copolymers containing ethylene, styrene, and divinylbenzene, which may worsen dielectric properties and water absorption. If it is larger than the above range, the proportion of polar groups will be small and the proportion of hydrocarbon moieties will be large, which may worsen oxidative degradation resistance and adhesion. When the proportion of hydrocarbon moieties, especially aliphatic hydrocarbons, is large, exposure to high temperature air will generate cyclic structures via oxygen on the aliphatic hydrocarbons, resulting in the generation of polar carbonyl groups. This results in a significant deterioration of dielectric properties. Within the above range, a cured product can be obtained that has excellent compatibility with copolymers and excellent dielectric properties, water absorption, resistance to oxidative degradation, and adhesion.

[0020] In one embodiment of this product, the maleimide equivalent is preferably 100 g / eq. to 300 g / eq., and in another embodiment, the maleimide equivalent is preferably 500 g / eq. to 730 g / eq., and being within these ranges can further suppress the rate of change in dielectric properties.

[0021] The maleimide resin in this embodiment is preferably a resin represented by the following formula (4).

[0022] (In formula (4), R ６ (where is an aliphatic hydrocarbon group with 1 to 60 carbon atoms, Z indicates an organic group, and p represents an integer between 2 and 4.)

[0023] R ６ The carbon number is preferably 2 to 50, and more preferably 3 to 40. Examples of aliphatic hydrocarbon groups include linear, branched, cyclic, and heteroatom-containing structures, of which linear or branched aliphatic hydrocarbon groups are preferred. The aliphatic hydrocarbon group is divalent.

[0024] Z is not particularly limited as long as it is an organic group, for example, a chain, alicyclic, or aromatic ring. It may be unsubstituted or substituted, and may contain heteroatoms. Examples of chains include alkanes, alkenes, and alkynes, and may have a straight or branched structure. Alicyclics may be monocyclic or bicyclic or more complex structures formed by multiple fused rings. They may also have an unsaturated structure. Specifically, the following organic groups are examples, but are not limited to these. Examples of alicyclics include cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, norbornane, bicycloundecane, decahydronaphthalene, norbornene, norbornadiene, etc. Examples of heteroatom-containing alicyclic rings include pyrrolidine, piperidine, morpholine, dioxane, dioxolane, tetrahydrothiophene, and isocyanuryl. Examples of aromatic rings include benzene, naphthalene, anthracene, and phenanthrene. Examples of heteroatom-containing aromatic rings include pyridine, pyrimidine, triazine, imidazole, and furan. Five-membered or six-membered rings are preferred for both heteroatom-containing alicyclic rings and aromatic rings. Furthermore, Z is preferably an aromatic ring with 6 to 10 carbon atoms or an alicyclic ring containing a heteroatom with 3 to 10 carbon atoms, and more preferably benzene or isocyanuryl. Benzene, being a monocyclic ring, exhibits low steric hindrance and excellent curing reactivity, and because it has no oxidative degradation sites, it has excellent heat resistance, dielectric properties, and dielectric property change rate. Isocyanuryl has good symmetry and no oxidative degradation sites, resulting in excellent dielectric properties and dielectric property change rate.

[0025] In the above formula (4), the value of p represents an integer between 2 and 4, with 2 and 3 being preferred, and 3 being even more preferred.

[0026] The maleimide resin of this embodiment is preferably obtained by reacting a diamine having 4 to 60 carbon atoms, a tetracarboxylic dianhydride represented by the following formula (2), and maleic anhydride. It has excellent compatibility with a copolymer and can obtain a cured product excellent in dielectric properties, water absorption, oxidation degradation resistance, and adhesion.

[0027]

[0028] In the formula (2), A is a structure represented by any one of the following formulas (1-a) to (1-u). From the viewpoints of compatibility, heat resistance, and oxidation degradation resistance, it is particularly preferably represented by the formula (1-f) or the formula (1-l).

[0029]

[0030] In the above formulas (1-a) to (1-u), the broken line part represents the bond with the acid anhydride group in the formula (2).

[0031] Examples of the diamine having 4 to 60 carbon atoms include linear or branched aliphatic diamines, aliphatic ether diamines, cyclic aliphatic diamines, or aromatic diamines. Only one kind of diamine may be used, or two or more kinds may be used.

[0032] Examples of the above linear or branched aliphatic diamines include linear saturated diamines such as tetradecanediamine, hexadecanediamine, octadecanediamine, eicosadiamine, docosadiamine, tetracosadiamine, and octacosadiamine; tetradecanediamine-7-ene, hexadecanediamine-6-ene, hexadecanediamine-8-ene, octadecanediamine-8-ene, octadecanediamine-10-ene, eicosadiamine-6-ene, eicosadiamine-8-ene, and eicosadiamine-12-ene. Linear unsaturated diamines such as eicosadiamine-8,12-diene, eicosadiamine-10,14-diene, docosadiamine-7,11,15-triene, docosadiamine-8,12,16-triene, 1,24-tetracosadiamine-8,12,16-triene, tetracosadiamine-10,14,18-triene; 6,8-dimethyltetradecanediamine, 7-ethyltetradecanediamine, 7-propyltetradecanediamine, 7-ethylhexadecanediamine, 7-butylhexadecanediamine, 7-I Branched saturated diamines such as sopropyl-10-methylhexadecanediamine, 8-ethyloctadecanediamine, 8-isopropyl-11-methyloctadecanediamine, 8,13-diethyloctadecanediamine, 8,13-dimethyleicosadiamine, 9,12-dimethyleicosadiamine, and 9,12-diethyleicosadiamine; 7-vinyltetradecanediamine, 7-vinylhexadecanediamine-8-ene, 7-isopropenyl-10-methylhexadecanediamine-9-ene, and 8-vinyl-octadeca Examples include diamine-9-ene, 7,12-dimethyloctadecanediamine-7,11-diene, 7,12-diethyloctadecanediamine-7,11-diene, 8-isopropenyl-11-methyloctadecanediamine-10-ene, 8-ethyl-11-isopropenyloctadecanediamine-10-ene, 8,13-dimethyleicosadiamine-8,12-diene, 9,12-dimethyleicosadiamine-8,12-diene, metaxylenediamine, paraxylenediamine, and orthoxyenediamine.

[0033] Examples of the aliphatic ether diamine include 2,2'-oxybis(ethylamine), 3,3'-oxybis(propylamine), 1,2-bis(2-aminoethoxy)ethane, and the like.

[0034] Examples of the cyclic aliphatic diamine include 1,3-bis(aminomethyl)cyclohexane, norbornanediamine, tricyclodecane dimethylamine, isophoronediamine, and the like.

[0035] Examples of the aromatic diamine include 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(aminomethyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 4,4'-diaminodiphenylmethane; 4,4'-diaminodiphenyl sulfone; 3,3'-diaminodiphenyl sulfone; 4,4-diaminobenzophenone; 4,4-diaminodiphenyl sulfide; 2,2-bis[4-(4-aminophenoxy)phenyl]propane.

[0036] From the viewpoints of adhesion to the copper foil, low moisture absorption, and oxidation degradation resistance, the number of carbon atoms of the diamine is preferably 6 to 60, more preferably 6 to 50, and particularly preferably 6 to 40.

[0037] Examples of tetracarboxylic dianhydrides include 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 1,2-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-tetramethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride (H-PMDA), and 1,1'-bicyclohexane-3,3',4,4'-tetracarboxylic acid-3,4:3',4'-deoxyanhydride (H-BP Alicyclic tetracarboxylic dianhydrides such as DA), 4-(2,5-dioxotetrahydrofuran-3-yl)-1,2,3,4-tetrahydronaphthalene-1,2-dicarboxylic acid anhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, bicyclo[2.2.2]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic acid dianhydride, 3,5,6-tricarboxy-2-norbornaneacetic acid dianhydride, or their aromatic rings Compounds substituted with lucyl groups or halogen atoms, semi-alicyclic tetracarboxylic dianhydrides such as 1,3,3a,4,5,9b-hexahydro-5(tetrahydro-2,5-dioxo-3-furanyl)naphtho[1,2-c]furan-1,3-dione, or compounds in which the hydrogen atoms of these aromatic rings are substituted with alkyl groups or halogen atoms, pyromellitic dianhydrides, 4,4'-oxydiphthalic dianhydrides, 3,3',4,4'-biphenyltetracarboxylic dianhydrides, 2,3,3',4'-biphenyltetracarboxylic dianhydrides, 2,2',3,3'-biphenyltetra Carboxylic acid dianhydride, 3,3',4,4'-bensofenonetetracarboxylic acid dianhydride, 2,2',3,3'-bensofenonetetracarboxylic acid dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, 1,2,5,Aromatic tetracarboxylic dianhydrides such as 6-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride, or compounds in which the aromatic rings of these compounds are substituted with an alkyl group or a halogen atom, and aromatic acid dianhydrides such as acid dianhydrides having an amide group can be mentioned.

[0038] A compound obtained by reacting a diamine having 4 to 60 carbon atoms, the tetracarboxylic dianhydride represented by the above formula (2), and maleic anhydride can be represented by the following formula (3).

[0039]

[0040] In formula (3), R １ , R ２ , R ３ represents a divalent hydrocarbon group, and R ４ and R ５ each independently represent one or more organic groups selected from a tetravalent organic group having a monocyclic or condensed polycyclic alicyclic structure and having 4 to 40 carbon atoms, a tetravalent organic group having 8 to 40 carbon atoms in which monocyclic alicyclic structures are directly or via a crosslinked structure linked to each other, and a tetravalent organic group having 8 to 40 carbon atoms and having a semi-alicyclic structure having both an alicyclic structure and an aromatic ring. m is an integer of 1 to 30, n is an integer of 0 to 30, and R ４ and R ５ may be the same or different from each other.

[0041] The maleimide resin represented by formula (3) above is not particularly limited, but from the viewpoint of good solubility in solvents, low melting point, low water absorption, and good compatibility with other resins, it is preferably 1,000 to 75,000, more preferably 1,500 to 50,000, and even more preferably 1,500 to 30,000. In this embodiment, "weight-average molecular weight" means the weight-average molecular weight on a polystyrene standard basis, calculated by gel permeation chromatography (GPC).

[0042] There are no particular restrictions on the method for producing the maleimide resin represented by formula (3) above, but it can be efficiently produced by, for example, the method shown below. The maleimide resin represented by formula (3) above can be obtained by following step I, in which an amic acid is synthesized from a tetracarboxylic dianhydride and a diamine, followed by ring-closing dehydration, then reacting with maleic anhydride to synthesize maleamic acid, and finally following step II, in which the molecular chain ends are sealed with maleimide groups by ring-closing dehydration.

[0043] In the above manufacturing method, each step can be broadly divided into two parts: the synthesis reaction of amic acid or maleamic acid and the ring-closing dehydration reaction, which will be described in detail below.

[0044] In step I, amic acid is first synthesized by reacting a specific tetracarboxylic dianhydride with a specific diamine. This reaction generally proceeds in an organic solvent (e.g., a nonpolar solvent or a high-boiling point aprotic polar solvent) at room temperature (25°C) to 100°C. The subsequent ring-closing dehydration reaction of amic acid proceeds under conditions of 90 to 120°C, while removing the by-product water from the system via a condensation reaction. Organic solvents (e.g., nonpolar solvents, high-boiling point aprotic polar solvents, etc.) or acid catalysts can be added to accelerate the ring-closing dehydration reaction.

[0045] Examples of organic solvents include toluene, xylene, anisole, biphenyl, naphthalene, N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). These may be used individually or in combination of two or more. Examples of acid catalysts include sulfuric acid, methanesulfonic acid, and trifluoromethanesulfonic acid. These may be used individually or in combination of two or more. The molar ratio of diamine to tetracarboxylic dianhydride is preferably diamine / tetracarboxylic dianhydride = 2.5 to 1.02 / 1.0, and more preferably diamine / tetracarboxylic dianhydride = 2.0 to 1.15 / 1.0. By blending in this ratio, a copolymer containing amino groups at both ends can be synthesized.

[0046] In step II, maleamic acid is synthesized by reacting the diamine having amino groups at both ends obtained in step I with maleic anhydride at room temperature (25°C) to 100°C. Finally, the molecular chain ends are sealed with maleimide groups by ring-closing dehydration while removing the by-product water in the system under conditions of 95 to 120°C, thereby obtaining the target maleimide resin represented by formula (3) above. It is preferable to carry out the sealing reaction with maleimide groups at the molecular chain ends at 120°C or below, as this reduces the likelihood of side reactions and the formation of high molecular weight products. With such a manufacturing method, the resulting compound has a block copolymer structure, which allows for uniform and improved compatibility of the synthesized resin.

[0047] The purification method for the maleimide resin represented by formula (3) above can be a conventional method, and methods such as reprecipitation and liquid-liquid separation can be used.

[0048] In the above reaction, it is preferable that the mixing ratio of the raw materials be such that (total number of moles of diamine used) : (1 / 2 of the total number of moles of tetracarboxylic dianhydride and maleic anhydride) is 1:1.

[0049] The following describes copolymers containing ethylene, styrene, and divinylbenzene. Copolymers can be obtained by copolymerizing ethylene, styrene, and divinylbenzene.

[0050] The number-average molecular weight (Mn) of the copolymer in this embodiment can be obtained by GPC, and is preferably 500 or more and less than 30,000, more preferably 750 or more and less than 27,500, and particularly preferably 1,000 or more and less than 25,000.

[0051] The ethylene content in the copolymer of this embodiment is preferably 20% by mass or more and 90% by mass or less, more preferably 25% by mass or more and 90% by mass or less, and particularly preferably 30% by mass or more and 90% by mass or less. When the ethylene content is 20% by mass or more, the toughness (elongation) and impact resistance of the cured product are improved, and cracking during curing and cracking during heat cycle testing of the cured product becomes less likely to occur.

[0052] The styrene content in the copolymer of this embodiment is preferably 0% by mass or more and 90% by mass or less, more preferably 5% by mass or more and 70% by mass or less, and particularly preferably 10% by mass or more and 60% by mass or less. When the styrene content is less than 70% by mass, the glass transition temperature of the cured product is lowered, which is preferable because it improves the toughness and elongation at room temperature. When the styrene content is 10% by mass or more, the aromaticity of the copolymer is improved, the compatibility with flame retardants and fillers is improved, bleed-out of flame retardants can be avoided, and the filler-filling properties can be improved. Furthermore, it is possible to obtain a cured resin composition with high peel strength from copper foil and copper wiring.

[0053] The copolymer of this embodiment may further contain an olefin compound. The olefin compound is one or more selected from α-olefins having 2 to 20 carbon atoms and cyclic olefins having 5 to 20 carbon atoms, and is a compound that is substantially free of oxygen, nitrogen, and halogens, and is composed of carbon and hydrogen. Examples of α-olefins having 2 to 20 carbon atoms include propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, and 3-methyl-1-butene Examples include 4-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, and 12-ethyl-1-tetradecene. Examples of cyclic olefins having 5 to 20 carbon atoms include norbornene and cyclopentene.

[0054] The copolymer of this embodiment may further contain a styrene compound. The styrene compound is an aromatic compound having 8 to 20 carbon atoms and one vinyl group, such as paramethylstyrene, paraisobutylstyrene, vinylnaphthalene, and vinylanthracene. It is not limited to these, and may be used individually or in combination.

[0055] The copolymer of this embodiment may further contain a divinyl compound. A divinyl compound is a compound having 5 to 20 carbon atoms and two vinyl groups, and examples include divinylnaphthalene, divinylanthracene, p-2-propenylstyrene, and p-3-butenylstyrene. Alternatively, for example, 1,2-bis(vinylphenyl)ethane (abbreviated as BVPE) can be used.

[0056] The copolymer of this embodiment may further contain polar groups, such as olefins containing oxygen atoms, nitrogen atoms, etc., aromatic vinyl compounds containing oxygen atoms, nitrogen atoms, etc., or aromatic polyenes containing oxygen atoms, nitrogen atoms, etc. However, the total mass of monomers containing these polar groups is preferably 10% by mass or less, more preferably 3% by mass or less, of the total mass of the resin composition, and most preferably no monomers containing polar groups are included. By keeping it at 10% by mass or less, the dielectric properties of the cured product obtained by curing the curable resin composition of this embodiment can be improved.

[0057] Examples of copolymers in this embodiment include ethylene-styrene-divinylbenzene copolymer, ethylene-propylene-styrene-divinylbenzene copolymer, ethylene-1-hexene-styrene-divinylbenzene copolymer, and ethylene-1-octene-styrene-divinylbenzene copolymer. Specifically, examples include Snecton S-700 (development product number: LDM-03-07), Snecton S-2000 (development product number: LDM-02-C), Snecton N-5000 (development product number: LDM-05-A), Snecton N-7000 (development product number: LDM-07-A), and Snecton S-710 (development product number: LDM-03L) (manufactured by Denka Co., Ltd.).

[0058] The copolymer content in the total amount of the curable resin composition of this embodiment is preferably 1% to 50% by mass, more preferably 3% to 40% by mass, and particularly preferably 5% to 20% by mass. If the content is less than the above range, the dielectric properties of the cured product will not be satisfactory. If the content is more than the above range, the heat resistance will decrease, and defects may occur during solder reflow. Within the above range, good dielectric properties can be obtained without degrading the heat resistance of the cured product.

[0059] The dielectric loss tangent Df of the cured product obtained by curing the curable resin composition of this embodiment is preferably 0.0025 or less, more preferably 0.0020 or less, and particularly preferably 0.0015 or less. The rate of change of the dielectric loss tangent Df after a 168-hour oxidation test can be calculated by the following formula: Rate of change of Df after 168h oxidation [%] = {(Df after 168h oxidation [-] - initial Df [-]) / initial Df [-]} × 100 The rate of change is preferably 200% or less, more preferably 175% or less, and particularly preferably 150% or less. The water absorption rate is preferably 0.5% or less, more preferably 0.45% or less, and particularly preferably 0.4% or less. The copper foil adhesion is preferably 0.3 N / mm or more, more preferably 0.35 N / mm or more, and particularly preferably 0.4 N / mm or more.

[0060] These properties are related to the compatibility of the curable resin composition, and the maleimide resin of this embodiment exhibits excellent compatibility with the copolymer. Furthermore, because the maleimide resin of this embodiment exhibits excellent compatibility with other maleimide resins, excellent properties can be achieved even when a composition containing three or more copolymers is used.

[0061] [Curing Accelerator] The curable resin composition of this embodiment can also have its curability improved by adding a curing accelerator. Preferred curing accelerators are anionic curing accelerators that promote the curing reaction by generating anions upon irradiation with ultraviolet light or visible light or by heating, or cationic curing accelerators that promote the curing reaction by generating cations upon irradiation with ultraviolet light or visible light or by heating.

[0062] Examples of anionic curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, and 2-ethyl-4-methylimidazole; trialkylamines such as triethylamine and tributylamine; 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)-undecene, with 4-dimethylaminopyridine and 1,8-diazabicyclo(5,4,0)-undecene being preferred. Other examples include phosphines such as triphenylphosphine, tetrabutylammonium salt, triisopropylmethylammonium salt, trimethyldecanylammonium salt, cetyltrimethylammonium salt, and quaternary ammonium salts such as hexadecyltrimethylammonium hydroxide, but are not limited to these. These may be used individually or in combination.

[0063] Examples of cationic curing accelerators include quaternary phosphonium salts such as triphenylbenzylphosphonium salt, triphenylethylphosphonium salt, and tetrabutylphosphonium salt (the counterions of the quaternary salts are halogens, organic acid ions, hydroxide ions, etc., with no particular preference, but organic acid ions and hydroxide ions are particularly preferred), tin octoate, zinc carboxylates (zinc 2-ethylhexanoate, zinc stearate, zinc behenate, zinc myristate), and zinc phosphate esters (zinc octyl phosphate, zinc stearyl phosphate), but are not limited to these. Furthermore, these may be used individually or in combination of multiple types.

[0064] The amount of curing accelerator used is 0.01 to 5.0 parts by mass per 100 parts by mass of the curable resin composition, as needed.

[0065] [Inorganic Fillers] The curable resin composition of this embodiment may contain inorganic fillers. Examples of inorganic fillers include, but are not limited to, powders such as fused silica, crystalline silica, porous silica, alumina, zircon, calcium silicate, calcium carbonate, quartz powder, silicon carbide, silicon nitride, boron nitride, zirconia, aluminum nitride, graphite, forsterite, steatite, spinel, mullite, titania, talc, clay, iron oxide, asbestos, and glass powder, or inorganic fillers made by shaping these into spheres or crushed forms. Furthermore, these may be used individually or in combination of multiple types.

[0066] When obtaining a curable resin composition for semiconductor encapsulation, the amount of inorganic filler used is preferably 80 to 92 parts by mass, and more preferably 83 to 90 parts by mass, per 100 parts by mass of the curable resin composition. Furthermore, when obtaining a curable resin composition for interlayer insulating layer forming materials, copper-clad laminates, prepregs, RCCs, and other substrate materials, the amount of the above-mentioned inorganic filler used is preferably 5 to 80 parts by mass, and more preferably 10 to 60 parts by mass, per 100 parts by mass of the curable resin composition.

[0067] [Polymerization Initiator] The curable resin composition of this embodiment can also have its curability improved by adding a polymerization initiator. A polymerization initiator is a compound capable of polymerizing olefin functional groups such as ethylenically unsaturated bonds, and examples include olefin metathesis polymerization initiators, anionic polymerization initiators, cationic polymerization initiators, and radical polymerization initiators. Among these, it is preferable to use a radical polymerization initiator that has curability and appropriate stability. A radical polymerization initiator is a compound that generates radicals by irradiation with ultraviolet light or visible light or by heating, and initiates a chain polymerization reaction. Examples of radical polymerization initiators that can be used include organic peroxides, azo compounds, and benzopinacols, and it is preferable to use organic peroxides because they have little effect on curing temperature control, outgassing suppression, and the electrical properties of decomposition products.

[0068] Examples of the above 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 and 1,3-bis(t-butylperoxyisopropyl)benzene, peroxyketals such as t-butyl peroxybenzoate and 1,1-di-t-butylperoxycyclohexane, α-cumyl peroxyneodecanoate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, t-amyl peroxy-2-ethylhexanoate, and t-butyl peroxy Examples of alkyl peresters such as oxy-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-butyl peroxycarbonyloxy)hexane; t-butyl hydroperoxide, cumene hydroperoxide, t-butyl peroxyoctoate, and lauroyl peroxide are examples, but are not limited to these. Furthermore, these may be used individually or in combination of multiple types. Among the above organic peroxides, ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peresters, and peroxycarbonates are preferred, with dialkyl peroxides being more preferred.

[0069] Examples of the above-mentioned azo compounds include, but are not limited to, azobisisobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile). Furthermore, these compounds may be used individually or in combination.

[0070] 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, per 100 parts by mass of the curable resin composition. If the amount of polymerization initiator used is less than 0.01 parts by mass, the molecular weight may not elongate sufficiently during the polymerization reaction, and if it is more than 5 parts by mass, dielectric properties such as dielectric constant and dielectric loss tangent may be impaired.

[0071] [Polymerization Inhibitor] The curable resin composition of this embodiment may contain a polymerization inhibitor. Including a polymerization inhibitor improves storage stability and allows 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, and facilitates B-stage production such as prepreg formation. If the polymerization reaction proceeds too far during prepreg formation, problems such as difficulty in lamination during the lamination process are likely to occur.

[0072] The polymerization inhibitor may be added when synthesizing the maleimide resin or copolymer of this embodiment, or after synthesis. It may also be added when preparing the resin composition. The amount of polymerization inhibitor used is 0.008 to 1 part by mass, preferably 0.01 to 0.5 parts by mass, per 100 parts by mass of the maleimide resin of this embodiment.

[0073] Examples of polymerization inhibitors include phenol-based, sulfur-based, phosphorus-based, hindered amine-based, nitroso-based, and nitroxyl radical-based agents. Furthermore, one polymerization inhibitor may be used, or multiple inhibitors may be used in combination. Of these, phenol-based, hindered amine-based, nitroso-based, and nitroxyl radical-based agents are preferred in this embodiment.

[0074] Examples of the above phenolic polymerization inhibitors 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, and 2,4-bis[(octylthio)methyl]-o-c Monophenols such as resols, 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-hydroxyhydrocinnamamide), 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- Bisphenols such as calcium trimethyl-4-hydroxybenzylsulfonate ethyl, 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 include, but are not limited to, high molecular weight phenols such as 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.

[0075] Examples of sulfur-based polymerization inhibitors include, but are not limited to, dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, and distearyl-3,3'-thiodipropionate.

[0076] Examples of the phosphorus polymerization inhibitors mentioned above include triphenyl phosphite, diphenylisodecyl phosphite, phenyldiisodecyl phosphite, tris(nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(octadecyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis(2,4-di-t-butyl-4-methylphenyl) phosphite, and bis[2- Examples include, but are not limited to, phosphites such as t-butyl-6-methyl-4-{2-(octadecyloxycarbonyl)ethyl}phenyl]hydrogen phosphite, 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.

[0077] Examples of the above hindered amine polymerization inhibitors include Adekastab LA-40MP, Adekastab LA-40Si, Adekastab LA-402AF, Adekastab LA-87, Adekastab LA-82, Adekastab LA-81, Adekastab LA-77Y, Adekastab LA-77G, Adekastab LA-72, Adekastab LA-68, Adekastab LA-63P, Adekastab LA-57, Adekastab Examples include, but are not limited to, LA-52, Chimassorb2020FDL, Chimassorb944FDL, Chimassorb944LD, Tinuvin622SF, TinuvinPA144, Tinuvin765, Tinuvin770DF, TinuvinXT55FB, Tinuvin111FDL, Tinuvin783FDL, Tinuvin791FB, etc.

[0078] Examples of the nitroso polymerization inhibitors mentioned above include, but are not limited to, p-nitrosophenol, N-nitrosodiphenylamine, and ammonium salts of N-nitrosophenylhydroxyamine (cuperone). Of these, ammonium salts of N-nitrosophenylhydroxyamine (cuperone) are preferred.

[0079] Examples of the above-mentioned nitroxyl radical polymerization inhibitors include, but are not limited to, di-tert-butylnitroxide, 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.

[0080] [Flame Retardant] The curable resin composition of this embodiment may contain a flame retardant. Examples of flame retardants include halogen-based flame retardants, inorganic flame retardants (antimony compounds, metal hydroxides, nitrogen compounds, boron compounds, etc.), and phosphorus-based flame retardants, but phosphorus-based flame retardants are preferred from the viewpoint of achieving halogen-free flame retardancy. The phosphorus-based flame retardant may be either reactive or additive type. Specific examples include phosphate esters such as trimethyl phosphate, triethyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl phosphate, cresyl-2,6-dixylenyl phosphate, 1,3-phenylenebis(dixylenyl phosphate), 1,4-phenylenebis(dixylenyl phosphate), and 4,4'-biphenyl(dixylenyl 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 resin with the active hydrogen of the above phosphanes; and red phosphorus, but are not limited to these. Furthermore, these may be used individually or in combination of multiple types. Of the above example substances, phosphate esters, phosphans, or phosphorus-containing epoxy compounds are preferred, and 1,3-phenylenebis(dixylenyl phosphate), 1,4-phenylenebis(dixylenyl phosphate), 4,4'-biphenyl(dixylenyl phosphate), or phosphorus-containing epoxy compounds are particularly preferred.

[0081] The flame retardant content is preferably in the range of 0.1 to 0.6 parts by mass per 100 parts by mass of the curable resin composition. If it is less than 0.1 parts by mass, the flame retardancy may be insufficient, and if it is more than 0.6 parts by mass, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0082] [Light stabilizer] The curable resin composition of this embodiment may also contain a light stabilizer. A hindered amine-based light stabilizer, particularly HALS, is preferred as the light stabilizer. Examples of HALS include the reaction product 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, the reaction product of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine, and 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 Examples include, but are not limited to, bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butylmalonate, bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis(1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, bis(1-octyroxy-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). Furthermore, these may be used individually or in combination.

[0083] The amount of light stabilizer is preferably in the range of 0.001 to 0.1 parts by mass per 100 parts by mass of the curable resin composition. If the amount is less than 0.001 parts by mass, it may be insufficient to exhibit the light stabilization effect, and if it is more than 0.1 parts by mass, it may adversely affect the hygroscopicity and dielectric properties of the cured product.

[0084] [Binder Resin] The curable resin composition of this embodiment may also use a binder resin. Examples of binder resins include butyral resins, acetal resins, acrylic resins, epoxy-nylon resins, NBR-phenolic resins, epoxy-NBR resins, silicone resins, etc., but are not limited to these. Furthermore, these may be used individually or in combination of multiple types.

[0085] The amount of binder resin 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 per 100 parts by mass of the curable resin composition, and more preferably 0.05 to 20 parts by mass is used as needed.

[0086] [Additives] The curable resin composition of this embodiment may also contain additives. Examples of additives include modified acrylonitrile copolymers, polyethylene, fluororesins, silicone gels, silicone oils, surface treatment agents for fillers such as silane coupling agents, mold release agents, and colorants such as carbon black, phthalocyanine blue, and phthalocyanine green.

[0087] The amount of additive added is preferably 1,000 parts by mass or less, more preferably 700 parts by mass or less, per 100 parts by mass of the curable resin composition.

[0088] The curable resin composition of this embodiment may further contain maleimide resins other than the maleimide resin of this embodiment, epoxy resins, activated ester compounds, phenolic resins, polyphenylene ether compounds, amine resins, compounds having ethylenically unsaturated bonds, isocyanate resins, polyamide resins, cyanate ester resins, polyimide resins, polybutadiene and its modified counterparts, polystyrene and its modified counterparts, polyethylene and its modified counterparts, etc., and these may be used individually or in combination of multiple types. Among these compounds, it is preferable to include maleimide resin, polyphenylene ether compounds, compounds having ethylenically unsaturated bonds, cyanate ester resins, polybutadiene and its modified counterparts, polystyrene and its modified counterparts, polyethylene and its modified counterparts, based on a balance of heat resistance, adhesion, and dielectric properties. By including these compounds, the brittleness of the cured product can be improved and adhesion to metal can be enhanced, and cracks in the package can be suppressed during reliability tests such as solder reflow and thermal cycling. The total amount of the above compounds used, unless otherwise specified, is preferably 80% by mass or less, more preferably 60% by mass or less, and most preferably 40% by mass or less, in the curable resin composition of this embodiment. Furthermore, the preferred lower limit is 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more. Within this range, the effects of each added compound can be added while taking advantage of the dielectric properties (low dielectric loss tangent) of the curable resin composition of this embodiment. Examples of these components can be used as shown below.

[0089] [Epoxy Resin] The following are examples of preferred epoxy resins, but are not limited to these. The epoxy resin may be liquid or solid, and may be used alone or in combination of multiple types.

[0090] Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin, phenol novolac type epoxy resin, alicyclic epoxy resin having an ester skeleton, cyclohexane type epoxy resin, cyclohexanedimethanol type epoxy resin, and epoxy resin having a butadiene structure. Specific examples include "RE310S", "RE410S" (both manufactured by Nippon Kayaku Co., Ltd., bisphenol A type epoxy resin), "RE303S", "RE304S", "RE403S", "RE404S" (all manufactured by Nippon Kayaku Co., Ltd., bisphenol F type epoxy resin), "HP4032", "HP4032D", "HP4032SS" (all manufactured by DIC Corporation, naphthalene type epoxy resin), "jER828US", "jER828EL", "jER825", "jER828EL" (all manufactured by Mitsubishi Chemical Corporation, bisphenol A type epoxy resin), "jER807", "jER1750" (both manufactured by Mitsubishi Chemical Corporation, bisphenol F type epoxy resin), and "jER152" (manufactured by Mitsubishi Chemical Corporation, F type epoxy resin). Examples include phenol novolac type epoxy resin, "jER630", "jER630LSD" (both manufactured by Mitsubishi Chemical Corporation, glycidylamine type epoxy resin), "ZX1059" (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., a mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" (manufactured by Nagase ChemteX Corporation, glycidyl ester type epoxy resin), "Celoxide 2021P" (manufactured by Daicel Corporation, alicyclic epoxy resin with an ester skeleton), "PB-3600" (manufactured by Daicel Corporation, epoxy resin with a butadiene structure), "ZX1658", "ZX1658GS" (both manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., liquid 1,4-glycidylcyclohexane type epoxy resin). These may be used individually or in combination of two or more types.

[0091] Preferred solid epoxy resins include, for example, bixylenol-type epoxy resin, naphthalene-type epoxy resin, naphthalene-type tetrafunctional epoxy resin, cresol novolac-type epoxy resin, dicyclopentadiene-type epoxy resin, trisphenol-type epoxy resin, naphthol-type epoxy resin, biphenyl-type epoxy resin, naphthylene ether-type epoxy resin, anthracene-type epoxy resin, bisphenol A-type epoxy resin, bisphenol AF-type epoxy resin, and tetraphenylethane-type epoxy resin.Specific examples include "HP4032H" (manufactured by DIC Corporation, naphthalene-type epoxy resin), "HP-4700", "HP-4710" (both manufactured by DIC Corporation, naphthalene-type tetrafunctional epoxy resins), "N-690" (manufactured by DIC Corporation, cresol novolac-type epoxy resin), "N-695" (manufactured by DIC Corporation, cresol novolac-type epoxy resin), "HP-7200", "HP-7200HH", "HP-7200H" (both manufactured by DIC Corporation, dicyclopentadiene-type epoxy resins), "EXA-7311", and "EXA-7311-G3". "EXA-7311-G4", "EXA-7311-G4S", "HP-6000" (all manufactured by DIC Corporation, naphthylene ether type epoxy resin), "EPPN-502H" (manufactured by Nippon Kayaku Co., Ltd., trisphenol type epoxy resin), "NC-7000L", "NC-7300" (both 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 type epoxy resin), "XD-1 "000-2L", "XD-1000-L", "XD-1000-H", "XD-1000-H" (all manufactured by Nippon Kayaku Co., Ltd., dicyclopentadiene 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" (all manufactured by Mitsubishi Chemical Corporation, biphenyl type epoxy resin), "YX-4000HK" (manufactured by Mitsubishi Chemical Corporation, bixylenol type epoxy resin) Examples include, "YX-8800" (manufactured by Mitsubishi Chemical Corporation, anthracene-type epoxy resin), "PG-100", "CG-500" (manufactured by Osaka Gas Chemical Co., Ltd., fluorene-type epoxy resin), "YL-7760" (manufactured by Mitsubishi Chemical Corporation, bisphenol AF-type epoxy resin), "YL-7800" (manufactured by Mitsubishi Chemical Corporation, fluorene-type epoxy resin), "jER1010" (manufactured by Mitsubishi Chemical Corporation, solid bisphenol A-type epoxy resin), and "jER1031S" (manufactured by Mitsubishi Chemical Corporation, tetraphenylethane-type epoxy resin). These may be used individually or in combination of two or more types.

[0092] [Active Ester Compounds] Active ester compounds are compounds that contain at least one ester bond in their structure, and on both sides of the ester bond, aliphatic chains, aliphatic rings, or aromatic rings are bonded. Examples of active ester compounds include compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. They are obtained by a condensation reaction between at least one compound of a carboxylic acid compound, an acid chloride, or a thiocarboxylic acid compound and at least one compound of a hydroxy compound or a thiol compound. In particular, from the viewpoint of improving heat resistance, it is preferable that they be obtained from a carboxylic acid compound or an acid chloride and a hydroxy compound, and phenol compounds or naphthol compounds are preferred as the hydroxy compound. Active ester compounds may be used alone or in combination of two or more.

[0093] Examples of the carboxylic acid compounds mentioned above include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

[0094] Examples of the above-mentioned acid chlorides include acetyl chloride, acrylate chloride, methacrylate chloride, malonyl chloride, succinate dichloride, diglycolyl chloride, glutarate dichloride, suberate dichloride, sebacate dichloride, adipic acid dichloride, dodecanediol dichloride, azera oil chloride, 2,5-franzicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesic acid chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyldicarbonyl chloride, and 4,4'-azodibenzoyl dichloride.

[0095] Examples of the above-mentioned phenol compounds and naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, phenol novolac, and phenol resins described later. Here, "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by the condensation of two molecules of phenol with one molecule of dicyclopentadiene.

[0096] Preferred examples of active ester compounds include active ester compounds containing a dicyclopentadiene-type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing an acetylated phenol novolac, active ester compounds containing a benzoylated phenol novolac, the compound described in Example 2 of International Publication No. 2020 / 095829, and the compounds disclosed in International Publication No. 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 represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

[0097] Commercially available active ester compounds include, for example, active ester compounds containing a dicyclopentadiene-type diphenol structure such as "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T", "HPC-8000H-65TM", "EXB-8000L-65TM", and "EXB-8150-65T" (manufactured by DIC Corporation), and active ester compounds containing a naphthalene structure such as "EXB9416-70BK" (manufactured by DIC Corporation), and phenol no Examples of active ester compounds containing acetylated volac include "DC808" (manufactured by Mitsubishi Chemical Corporation), active ester compounds containing benzoylated phenol novolac include "YLH1026", "YLH1030", and "YLH1048" (manufactured by Mitsubishi Chemical Corporation), active ester curing agent which is an acetylated phenol novolac includes "DC808" (manufactured by Mitsubishi Chemical Corporation), and phosphorus atom-containing active ester curing agent includes "EXB-9050L-62M" manufactured by DIC Corporation.

[0098] Regarding the blending ratio of the active ester compound and epoxy resin, the ratio of the active ester equivalent (α) to the epoxy equivalent (β) (α / β) is preferably 0.5 to 1.5, more preferably 0.8 to 1.2, and even more preferably 0.90 to 1.10. If it falls outside the above range, there is a risk that excess epoxy groups or active ester groups will remain in the system, which may lead to deterioration of properties in high-temperature storage tests (e.g., 150°C, 1000 hours) or long-term reliability tests under high-temperature and high-humidity conditions (e.g., temperature: 85°C, humidity: 85%).

[0099] [Phenol Resins] Phenolic resins are compounds having two or more phenolic hydroxyl groups in their molecules. Examples of phenolic resins include, but are not limited to, reaction products of phenols and aldehydes, reaction products of phenols and diene compounds, reaction products of phenols and ketones, reaction products of phenols and substituted biphenyls, reaction products of phenols and substituted phenyls, reaction products of bisphenols and aldehydes, etc. Furthermore, these may be used individually or in combination of multiple types. Specific examples of the above raw materials are given below, but are not limited to these. <Phenols> Phenol, alkyl-substituted phenol, aromatic-substituted phenol, hydroquinone, resorcinol, naphthol, alkyl-substituted naphthol, dihydroxybenzene, alkyl-substituted dihydroxybenzene, dihydroxynaphthalene, etc. <Aldehydes> Formaldehyde, acetaldehyde, alkylaldehyde, benzaldehyde, alkyl-substituted benzaldehyde, hydroxybenzaldehyde, naphthaldehyde, glutaraldehyde, phthalaldehyde, crotonaldehyde, cinnamaldehyde, furfural, etc. <Diene Compounds> Dicyclopentadiene, terpenes, vinylcyclohexene, norbornadiene, vinylnorbornene, tetrahydroindene, divinylbenzene, divinylbiphenyl, diisopropenylbiphenyl, butadiene, isoprene, etc. <Ketones> Acetone, methyl ethyl ketone, methyl isobutyl ketone, acetophenone, benzophenone, fluorenone, etc. <Substitutive biphenyls> 4,4'-bis(chloromethyl)-1,1'-biphenyl, 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 4,4'-bis(hydroxymethyl)-1,1'-biphenyl, etc. <Substitutive phenyls> 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene, 1,4-bis(hydroxymethyl)benzene, etc.

[0100] [Polyphenylene Ether Compounds] From the viewpoint of heat resistance and electrical properties, polyphenylene ether compounds are preferably polyphenylene ether compounds having ethylenically unsaturated bonds, and more preferably polyphenylene ether compounds having acrylic groups, methacrylic groups, or styrene structures. Commercially available products include SA-9000 (manufactured by SABIC, a polyphenylene ether compound having methacrylic groups), OPE-2St 1200, and OPE-2St 2200 (manufactured by Mitsubishi Gas Chemical Co., Ltd., a polyphenylene ether compound 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 molecular weight is less than 500, the heat resistance of the cured product tends not to be sufficient. Also, if the molecular weight is greater than 5000, the melt viscosity becomes high, and sufficient fluidity cannot be obtained, which tends to lead to molding defects. Furthermore, reduced reactivity leads to a longer curing time, an increase in unreacted material not incorporated into the curing system, a decrease in the glass transition temperature of the cured product, and a tendency for the heat resistance of the cured product to decrease. If the number-average molecular weight of the polyphenylene ether compound is between 500 and 5000, it is possible to exhibit excellent heat resistance and moldability while maintaining excellent dielectric properties. Specifically, the number-average molecular weight can be measured using methods such as gel permeation chromatography.

[0101] Polyphenylene ether compounds may be obtained by polymerization reactions, or by redistributing high molecular weight polyphenylene ether compounds with a number average molecular weight of about 10,000 to 30,000. Alternatively, these may be used as raw materials and reacted with compounds having ethylenically unsaturated bonds, such as methacrylic chloride, acrylic chloride, and chloromethylstyrene, to impart radical polymerizability. Polyphenylene ether compounds obtained by redistribution reactions can 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 induce a redistribution reaction. Polyphenylene ether compounds obtained by such redistribution reactions are preferable because they have hydroxyl groups derived from phenolic compounds that contribute to curing at both ends of the molecular chain, thus maintaining even higher heat resistance, and because functional groups can be introduced to both ends of the molecular chain even after modification with a compound having ethylenically unsaturated bonds. Furthermore, polyphenylene ether compounds obtained by polymerization reactions are preferable because they exhibit excellent fluidity.

[0102] The molecular weight of polyphenylene ether compounds can be adjusted by adjusting polymerization conditions, etc., in the case of polyphenylene ether compounds obtained by polymerization reactions. In the case of polyphenylene ether compounds obtained by redistribution reactions, the molecular weight of the resulting polyphenylene ether compound can be adjusted by adjusting the conditions of the redistribution reaction, etc. More specifically, this can be done by adjusting the amount of phenolic compound used in the redistribution reaction. That is, the higher the amount of phenolic compound used, the lower the molecular weight of the resulting polyphenylene ether compound. In this case, poly(2,6-dimethyl-1,4-phenylene ether) can be used as the high molecular weight polyphenylene ether compound that undergoes the redistribution reaction. Furthermore, the phenolic compound used in the above redistribution reaction is not particularly limited, but polyfunctional phenolic compounds having two or more phenolic hydroxyl groups in the molecule, such as bisphenol A, phenol novolac, and cresol novolac, are preferably used. These may be used individually or in combination of two or more.

[0103] [Amine Resins] Amine resins are compounds having two or more amino groups in their molecule. Examples of amine resins include diaminodiphenylmethane, diaminodiphenylsulfone, isophoronediamine, naphthalenediamine, aniline novolac (reaction product of aniline and formalin), N-methylaniline novolac (reaction product of N-methylaniline and formalin), orthoethylaniline novolac (reaction product of orthoethylaniline and formalin), reaction product of 2-methylaniline and formalin, reaction product of 2,6-diisopropylaniline and formalin, reaction product of 2,6-diethylaniline and formalin, reaction product of 2-ethyl-6-ethylaniline and formalin, reaction product of 2,6-dimethylaniline and formalin, and those obtained by the reaction of aniline with xylylene chloride. Examples of aniline resins include, but are not limited to, aniline and substituted biphenyls (such as 4,4'-bis(chloromethyl)-1,1'-biphenyl and 4,4'-bis(methoxymethyl)-1,1'-biphenyl) as described in Japanese Patent Publication No. 6429862, aniline and substituted phenyls (such as 1,4-bis(chloromethyl)benzene, 1,4-bis(methoxymethyl)benzene and 1,4-bis(hydroxymethyl)benzene), 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, aniline and diisopropenylbenzene, and dimer amines. Furthermore, these may be used individually or in combination.

[0104] [Isocyanate resin] An isocyanate resin is a compound that has two or more isocyanate groups in its molecule. Examples of isocyanate resins include, but are not limited to, aromatic diisocyanates such as p-phenylenediisocyanate, m-phenylenediisocyanate, p-xylenediisocyanate, m-xylenediisocyanate, 2,4-tollylenediisocyanate, 2,6-tollylenediisocyanate, 4,4'-diphenylmethanediisocyanate, and naphthalenediisocyanate; aliphatic or alicyclic diisocyanates such as isophorone diisocyanate, hexamethylenediisocyanate, 4,4'-dicyclohexylmethanediisocyanate, hydrogenated xylenediisocyanate, norbornenediisocyanate, and lysinediisocyanate; biuret compounds of one or more isocyanate monomers; or isocyanates obtained by trimerizing the above diisocyanate compounds; and polyisocyanates obtained by urethane reaction between the above isocyanate compounds and polyol compounds. Furthermore, these can be used individually or in combination.

[0105] [Polyamide Resins] Examples of polyamide resins include reaction products of one or more of diamines, diisocyanates, or oxazolines with dicarboxylic acids, reaction products of diamines and acid chlorides, and ring-opening polymers of lactam compounds. These may be used individually or in combination of multiple types. Specific examples of the above raw materials are given below, but the material is not limited to these.<Diamines> 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, dimeramine, 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 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, diaminodiphenylsulfone, 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 [phenoxy)phenyl]propane, bis[4-(4-aminophenoxy)phenyl]sulfone, 2,2-bis(3-amino-4-hydroxyphenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-(1,3-phenylenediisopropylidene)bisaniline, 4,4'-(1,4-phenylenediisopropylidene)bisaniline, 9,9-bis(4-aminophenyl)fluorene, 2,7-diaminofluorene, aminobenzylamine, diaminobenzophenone, etc.<Diisocyanates> 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, etc. <Dicarboxylic acids> Oxalic acid, malonic acid, succicic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, undecanediic acid, dodecanediic 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, francicarboxylic acid, 4,4'-dicarboxydiphenyl ether, 4,4'-dicarboxydiphenyl sulfide, etc. <Acid Chlorides> Acetyl chloride, acrylate chloride, methacrylate chloride, malonyl chloride, succinate dichloride, diglycolyl chloride, glutarate dichloride, suberate dichloride, sebacate dichloride, adipic acid dichloride, dodecane dioyl chloride, azera oil chloride, 2,5-franzicarbonyl dichloride, phthaloyl chloride, isophthaloyl chloride, terephthaloyl chloride, trimesinate chloride, bis(4-chlorocarbonylphenyl) ether, 4,4'-diphenyl dicarbonyl chloride, 4,4'-azodibenzoyl dichloride, etc. <Lactams> ε-caprolactam, ω-undecane lactam, ω-laurolactam, etc.

[0106] [Polyimide Resin] Examples of polyimide resins include, but are not limited to, the reaction products of the above-mentioned diamine and the tetracarboxylic dianhydrides exemplified below. Furthermore, these may be used individually or in combination of multiple types. <Tetracarboxylic Dianhydrides> 4,4'-(hexafluoroisopropylidene)diphthalic anhydride, 5-(2,5-dioxotetrahydro-3-furanyl)-3-methyl-cyclohexene-1,2-dicarboxylic 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 '-diphenylsulfontetracarboxylic acid dianhydride, 2,2',3,3'-biphenyltetracarboxylic acid dianhydride, methylene-4,4'-diphthalic acid dianhydride, 1,1-ethylidene-4,4'-diphthalic acid dianhydride, 2,2'-propyridene-4,4'-diphthalic acid dianhydride, 1,2-ethylene-4,4'-diphthalic acid dianhydride, 1,3-trimethylene-4,4'-diphthalic acid dianhydride, 1,4-tetramethylene-4,4'-diphthalic acid dianhydride, 1,5-pentamethylene-4,4'- Diphthalic acid dianhydride, 4,4'-oxydiphthalic acid dianhydride, thio-4,4'-diphthalic acid 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]methane dianhydride, 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 acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic acid dianhydride, 1,2,5,6-naphthalenetetracarboxylic acid dianhydride, 3,4,9,10-perylenetetracarboxylic acid dianhydride, 2,3,6,7-anthracenetetracarboxylic acid dianhydride, 1,2,7,8-phenanthrenetetracarboxylic acid dianhydride, ethylenetetracarboxylic acid dianhydride, 1,2,3,4-butanetetracarboxylic acid dianhydride, 1, 2,3,4-cyclobutanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, cyclohexane-1,2,3,4-tetracarboxylic dianhydride, cyclohexane-1,2,4,5-tetracarboxylic dianhydride, 3,3',4,4'-bicyclohexyltetracarboxylic 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 (Bonic acid) dianhydride, 1,1-ethylidene-4,4'-bis(cyclohexane-1,2-dicarboxylic acid) dianhydride, 2,2-propyridene-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]octo-7-ene-2,3,5,6-tetracarboxylic acid dianhydride Water compounds, 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'-biphenylbis(trimellitic acid monoester anhydride), 9,9'-bis(3,4-dicarboxyphenyl)fluorene dianhydride, etc.

[0107] [Maleimide resins other than the maleimide resin of this embodiment] The curable resin composition of this embodiment may contain maleimide resins other than the maleimide resin of this embodiment. Specifically, it may contain aromatic maleimide resins or maleimide resins having at least one structure of the above formula (1) in the molecule with a maleimide equivalent of 750 g / eq. For example, 4,4'-diphenylmethanebismaleimide, polyphenylmethanemaleimide, m-phenylenebismaleimide, 2,2'-bis[4-(4-maleimoidphenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, 4,4'-diphenyletherbismaleimide, 4,4'-diphenylsulfonebismaleimide, 1,3-bis(3-maleimoidphenoxy) C) Benzene, 1,3-bis(4-maleimidophenoxy)benzene, Zyloc-type maleimide resin (anilix maleimide, manufactured by Mitsui Chemicals Fine Co., Ltd.), biphenyl aralkyl-type maleimide resin (solidified by solvent distillation under reduced pressure of a resin solution containing maleimide resin (M2) described in Example 4 of Japanese Patent Publication No. 2009-001783), bisaminocumylbenzene-type maleimide (maleimide resin described in International Publication No. 2020 / 054601), maleimide resin having an indan structure described in Japanese Patent No. 6629692 or International Publication No. 2020 / 217679, MATERIAL STAGE Vol. 18, No. 12 2019 "Continued Epoxy Resin CAS Number Story - Curing Agent CAS Number Memo No. 31 Bismaleimide (1)" and MATERIAL STAGE Vol. Examples include, but are not limited to, the maleimide resins described in 19, No. 2 2019, "Continued Story of Epoxy Resin CAS Numbers - Memorandum on Hardener CAS Numbers, Part 32: Bismaleimide (2)". Furthermore, these can be used individually or in combination.

[0108] [Cyanate Ester Resins] Cyanate ester resins are cyanate ester compounds obtained by reacting phenol resins with cyanide halides. Specific examples include, but are not limited to, dicyanate benzene, tricyanate benzene, dicyanate naphthalene, dicyanate biphenyl, 2,2'-bis(4-cyanatephenyl)propane, bis(4-cyanatephenyl)methane, bis(3,5-dimethyl-4-cyanatephenyl)methane, 2,2'-bis(3,5-dimethyl-4-cyanatephenyl)propane, 2,2'-bis(4-cyanatephenyl)ethane, 2,2'-bis(4-cyanatephenyl)hexafluoropropane, bis(4-cyanatephenyl)sulfone, bis(4-cyanatephenyl)thioether, phenol novolac cyanate, and phenol-dicyclopentadiene cocondensates in which the hydroxyl groups have been converted to cyanate groups. Furthermore, these may be used individually or in combination of multiple types. In addition, the cyanate ester compound whose synthesis method is described in Japanese Patent Application Publication No. 2005-264154 is particularly preferred as a cyanate ester compound because it has excellent low hygroscopicity, flame retardancy, and dielectric properties. The cyanate ester resin may also contain catalysts 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 and form a sym-triazine ring as needed.

[0109] The catalyst is preferably used in an amount of 0.0001 to 0.10 parts by mass, more preferably 0.00015 to 0.0015 parts by mass, per 100 parts by mass of the cyanate ester resin and curable resin composition.

[0110] [Polybutadiene and its modified products] Polybutadiene and its modified products are compounds that have polybutadiene or a structure derived from polybutadiene within their molecule. The structure derived from polybutadiene may have some or all of its unsaturated bonds converted to single bonds by hydrogenation. Examples of polybutadiene and its modified products include, but are not limited to, polybutadiene, hydroxyl-terminated polybutadiene, terminally (meth)acrylated polybutadiene, carboxylic acid-terminated polybutadiene, amine-terminated polybutadiene, and styrene-butadiene rubber. Furthermore, these may be used individually or in combination. Of 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, RICON-184 (all manufactured by Clay 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 weight-average molecular weight of polybutadiene and styrene-butadiene rubber is preferably 500 to 10000, more preferably 750 to 7500, and even more preferably 1000 to 5000. Below the lower limit of the above range, the volatility is high, making it difficult to adjust the solid content during prepreg preparation, and above the upper limit of the above range, the compatibility with other curable resins deteriorates. In general, in the case of compounds containing heteroatoms such as oxygen and nitrogen, such as bismaleimide and polymaleimide, it is difficult to ensure compatibility with low-polarity compounds such as compounds mainly composed of hydrocarbons or compounds consisting only of hydrocarbons, due to their polarity. On the other hand, the maleimide resin and copolymer of this embodiment do not have a framework design that actively incorporates heteroatoms such as oxygen and nitrogen, resulting in materials that exhibit low polarity and low dielectric loss tangent, as well as excellent compatibility with compounds composed solely of hydrocarbons.

[0111] [Polystyrene and its modified products] Polystyrene and its modified products are polystyrene or compounds that have a structure derived from polystyrene within their molecules. Examples of polystyrene and its modified products 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 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.), and 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 block copolymer: Septon 8004, Septon 8006, Septon 8007L, all manufactured by Kuraray Co., Ltd.), SEEPS-OH (compound having hydroxyl groups at the ends of styrene-ethylene / ethylene-propylene-styrene block copolymer: Septon HG252, manufactured by Kuraray Co., Ltd.), SIS (styrene-isoprene-styrene block copolymer: Septon 5125, Septon 5127, all manufactured by Kuraray Co., Ltd.), Hydrogenated SIS (hydrogenated styrene-isoprene-styrene block copolymer: Hybrar 7125F, Hybrar 7311F Examples include, but are not limited to, polystyrene-isobutylene-styrene block copolymers (SIBS: SIBSTAR073T, SIBSTAR102T, SIBSTAR103T (all manufactured by Kaneka Corporation), Septon V9827 (manufactured by Kuraray Co., Ltd.)), etc. Furthermore, these may be used individually or in combination. Polystyrene and its modified products are preferable to have those without unsaturated bonds because they have higher heat resistance and are less susceptible to oxidative degradation.Furthermore, while there are no particular restrictions on the weight-average molecular weight of polystyrene and its modified products as long as it is 10,000 or more, if it is too high, the compatibility with polyphenylene ether compounds, as well as 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 preferable that the weight-average molecular weight be around 10,000 to 300,000.

[0112] [Polyethylene and Modified Products thereof] Polyethylene and modified products thereof refer to polyethylene or compounds having a structure derived from polyethylene within their molecules. Examples of polyethylene and modified products thereof include, but are not limited to, ethylene-propylene copolymers, ethylene-styrene copolymers, ethylene-propylene-ethylidene norbornene copolymers (Mitsui Chemicals, Ltd. EBT: K-8370EM, K-9330M, etc.), ethylene-propylene-vinyl norbornene copolymers (Mitsui Chemicals, Ltd. VNB-EPT: PX-006M, PX-008M, PX-009M, etc.), 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 and ethylene-propylene-vinyl norbornene copolymers that contain a crosslinkable structure. Furthermore, these may be used individually or in combination of multiple types. While there are no particular restrictions on the weight-average molecular weight of polyethylene and its modified products as long as it is 10,000 or more, if it is too high, the compatibility with polyphenylene ether compounds, as well as 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 preferable that the molecular weight be around 10,000 to 300,000.

[0113] [Compounds containing ethylenically unsaturated bonds] Compounds containing ethylenically unsaturated bonds are compounds that have ethylenically unsaturated bonds in their molecule, which can be polymerized by heat or light, regardless of whether a polymerization initiator is used or not. However, compounds that contain ethylenically unsaturated bonds among the aforementioned maleimide resins, copolymers containing ethylene, styrene and divinylbenzene, polystyrene and its modified products, polybutadiene and its modified products, polyethylene and its modified products, etc., are not included in this classification.

[0114] Functional groups having ethylenically unsaturated bonds include, but are not limited to, the following disclosures, vinyl groups, allyl groups (2-propenyl groups), 1-propenyl groups, methallyl groups (2-methyl-2-propenyl groups), (meth)acrylic groups, acenaphthyl groups, indenyl groups, citraconimide groups, itaconimide groups, nadiimide groups, allylnadiimide groups, and cyclopentadienyl groups. Vinyl groups, styryl groups, (meth)acrylic groups, acenaphthyl groups, and indenyl groups are preferred, and vinyl groups, (meth)acrylic groups, acenaphthyl groups, and indenyl groups are more preferred. (Meth)acrylic groups mean methacrylic groups and / or acrylic groups, and (meth)acrylates mean methacrylates and / or acrylates.

[0115] Examples of compounds having a vinyl group include, but are not limited to, compounds having a styryl group, trivinylcyclohexane, 9-vinylfluorene, and thermosetting cycloolefin copolymers (Gigafreak, manufactured by Mitsui Chemicals, and TU-01A, manufactured by Nippon Zeon Co., Ltd.).

[0116] Compounds having a styryl group include, but are not limited to, styrene, vinyltoluene, 2-vinylbiphenyl, 3-vinylbiphenyl, 4-vinylbiphenyl, 1-vinylnaphthalene, 2-vinylnaphthalene, 2-vinylfluorene, α-methylstyrene, α-ethylstyrene, α-propylstyrene, α-n-butylstyrene, α-isobutylstyrene, α-t-butylstyrene, α-n-pentylstyrene, α-2-methylbutylstyrene, α-3-methylbutylstyrene, α-t-pentylstyrene, α-n-hexyl Glustystyrene, α-2-methylpentylstyrene, α-3-methylpentylstyrene, α-1-methylpentylstyrene, α-2,2-dimethylbutylstyrene, α-2,3-dimethylbutylstyrene, α-2,4-dimethylbutylstyrene, α-3,3-dimethylbutylstyrene, α-3,4-dimethylbutylstyrene, α-4,4-dimethylbutylstyrene, α-2-ethylbutylstyrene, α-1-ethylbutylstyrene, α-cyclohexylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, p-ethylvinylbenzene, 2-vinyl 2'-ethylbiphenyl, 2-vinyl-3'-ethylbiphenyl, 2-vinyl-4'-ethylbiphenyl, 3-vinyl-2'-ethylbiphenyl, 3-vinyl-3'-ethylbiphenyl, 3-vinyl-4'-ethylbiphenyl, 4-vinyl-2'-ethylbiphenyl, 4-vinyl-3'-ethylbiphenyl, 4-vinyl-4'-ethylbiphenyl, 1-vinyl-2-ethylnaphthalene, 1-vinyl-3-ethylnaphthalene, 1-vinyl-4-ethylnaphthalene, 1-vinyl-5-ethylnaphthalene, 1-vinyl-6-ethylnaphthalene, 1-vinyl- 7-ethylnaphthalene, 1-vinyl-8-ethylnaphthalene, 2-vinyl-1-ethylnaphthalene, 2-vinyl-3-ethylnaphthalene, 2-vinyl-4-ethylnaphthalene, 2-vinyl-5-ethylnaphthalene, 2-vinyl-6-ethylnaphthalene, 2-vinyl-7-ethylnaphthalene, 2-vinyl-8-ethylnaphthalene, m-methylstyrene, p-methylstyrene, m-propylstyrene, p-propylstyrene, m-n-butylstyrene, p-n-butylstyrene, m-t-butylstyrene, p-t-butylstyrene, m-n-hexylstyrene,p-n-hexylstyrene, m-cyclohexylstyrene, p-cyclohexylstyrene, 2-vinyl-2'-propylbiphenyl, 2-vinyl-3'-propylbiphenyl, 2-vinyl-4'-propylbiphenyl, 3-vinyl-2'-propylbiphenyl, 3-vinyl-3'-propylbiphenyl, 3-vinyl-4'-propylbiphenyl, 4-vinyl-2'-propylbiphenyl, 4-vinyl-3'-propylbiphenyl, 4-vinyl-4'-propylbiphenyl, 1-vinyl-2-propylnaphthalene, 1-vinyl-3-propylnaphthalene, 1- Vinyl-4-propylnaphthalene, 1-vinyl-5-propylnaphthalene, 1-vinyl-6-propylnaphthalene, 1-vinyl-7-propylnaphthalene, 1-vinyl-8-propylnaphthalene, 2-vinyl-1-propylnaphthalene, 2-vinyl-3-propylnaphthalene, 2-vinyl-4-propylnaphthalene, 2-vinyl-5-propylnaphthalene, 2-vinyl-6-propylnaphthalene, 2-vinyl-7-propylnaphthalene, 2-vinyl-8-propylnaphthalene, o-ethoxystyrene, m-ethoxystyrene, p-ethoxystyrene, o- Propoxystyrene, m-propoxystyrene, p-propoxystyrene, o-n-butoxystyrene, m-n-butoxystyrene, p-n-butoxystyrene, o-isobutoxystyrene, m-isobutoxystyrene, p-isobutoxystyrene, o-t-butoxystyrene, m-t-butoxystyrene, p-t-butoxystyrene, o-n-pentoxystyrene, m-n-pentoxystyrene, p-n-pentoxystyrene, α-methyl-o-butoxystyrene, α-methyl-m-butoxystyrene, α-methyl-p-butoxystyrene, o-t-pent Xystyrene, m-t-pentoxystyrene, p-t-pentoxystyrene, o-n-hexoxystyrene, m-n-hexoxystyrene, p-n-hexoxystyrene, α-methyl-o-pentoxystyrene, α-methyl-m-pentoxystyrene, α-methyl-p-pentoxystyrene, o-cyclohexoxystyrene, m-cyclohexoxystyrene, p-cyclohexoxystyrene, o-phenoxystyrene, m-phenoxystyrene, p-phenoxystyrene, divinylbenzene, divinylnaphthalene, divinylbiphenyl, divinylfluorene,BVPM (bis(vinylphenyl)methane), BVPE (bis(vinylphenyl)ethane), BVPH (bis(vinylphenyl)hexane), poly(arylene ether) polymers (HC-G0037, HC-G0024, HC-G0030, HC-G0038, all manufactured by JSR Corporation. These may contain monomer units containing pyridazine, pyrimidine, or pyrazine groups), fluorenes or indenes and halogenated compounds containing ethylenically unsaturated bonds (chromium Examples include reaction products with methylstyrene (such as allyl chloride, metharyl chloride, acrylate chloride, and methacrylate chloride), compounds described in Japanese Patent No. 6951829, copolymers containing divinylbenzene as a constituent unit (not limited to the following examples, but such as ODV-XET(X3), ODV-XET(X4), and ODV-XET(X5), all manufactured by Nippon Steel Chemical & Material Co., Ltd.), and reaction products of the aforementioned phenolic resin and chloromethylstyrene.

[0117] Compounds having an allyl group include, but are not limited to, the aforementioned phenol resin and allyl chloride reaction products, and reaction products of ethylenically unsaturated bond-containing phenols (2-allylphenol, 4-allylphenol, eugenol, etc.) and halogenated compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuryl chloride, etc.).

[0118] Compounds having a 1-propenyl group include, but are not limited to, the following disclosures, examples of which are reaction products of ethylenically unsaturated bond-containing phenols (2-propenylphenol, 4-propenylphenol, isoeugenol, etc.) and halogenated compounds (1,4-bis(chloromethyl)benzene, 4,4'-bis(chloromethyl)biphenyl, 4,4'-difluorobenzophenone, 4,4'-dichlorobenzophenone, 4,4'-dibromobenzophenone, cyanuryl chloride, etc.).

[0119] Compounds having a methallyl group include, but are not limited to, the reaction products of the aforementioned phenolic resin and methallyl chloride.

[0120] Compounds having a (meth)acrylic group include, but are not limited to, monofunctional (meth)acrylates, polyfunctional (meth)acrylates, urethane (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates, and reactive oligomers in which these bonds are used in combination, as well as acid-modified products thereof.

[0121] Examples of monofunctional (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, lauryl (meth)acrylate, polyethylene glycol (meth)acrylate, polyethylene glycol (meth)acrylate monomethyl ether, phenylethyl (meth)acrylate, isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, and tetrahydrofurfuryl (meth)acrylate.

[0122] Examples of polyfunctional (meth)acrylates include tridiclodecane dimethanol di(meth)acrylate, butanediol di(meth)acrylate, hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, nonanediol di(meth)acrylate, glycol di(meth)acrylate, diethylene di(meth)acrylate, polyethylene glycol di(meth)acrylate, tris(meth)acryloyloxyethyl isocyanurate, polypropylene glycol di(meth)acrylate, bisphenolethylene oxide di(meth)acrylate, hydrogenated bisphenolethylene oxide (meth)acrylate, bisphenol di(meth)acrylate, ε- Examples include neopentyl glycol di(meth)acrylate modified from caprolactone hydroxypivalate, ε-caprolactone modified dipentaerythritol hexa(meth)acrylate, ε-caprolactone modified dipentaerythritol poly(meth)acrylate, dipentaerythritol poly(meth)acrylate, trimethylolpropane tri(meth)acrylate, triethylolpropane tri(meth)acrylate and its ethylene oxide adducts, pentaerythritol tri(meth)acrylate and its ethylene oxide adducts, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate and its ethylene oxide adducts.

[0123] Also included are mono, di, tri, or tetra(meth)acrylates of triols obtained by adding 1 mole or more of a cyclic lactone compound such as ε-caprolactone, γ-butyrolactone, or δ-valerolactone to 1 mole of pentaerythritol, dimethylolpropane, trimethylolpropane, or tetramethylolpropane; mono or poly(meth)acrylates of triols obtained by adding 1 mole or more of a cyclic lactone compound such as ε-caprolactone, γ-butyrolactone, or δ-valerolactone to 1 mole of dipentaerythritol; and mono(meth)acrylates or poly(meth)acrylates of polyhydric alcohols such as tetraol, pentaol, or hexaol.

[0124] Examples of urethane (meth)acrylates include reaction products of hydroxyl group-containing (meth)acrylates with polyisocyanates and other alcohols used as needed.

[0125] Examples of hydroxyl group-containing (meth)acrylates include hydroxyalkyl (meth)acrylates such as hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, and hydroxybutyl (meth)acrylate; glycerin (meth)acrylates such as glycerin mono (meth)acrylate and glycerin di (meth)acrylate; sugar alcohol (meth)acrylates such as pentaerythritol di (meth)acrylate, pentaerythritol tri (meth)acrylate, dipentaerythritol penta (meth)acrylate, and dipentaerythritol hexa (meth)acrylate; and epoxy (meth)acrylates, which will be described later.

[0126] Examples of polyisocyanates include toluene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, isophorone diisocyanate, norbornene diisocyanate, xylene diisocyanate, hydrogenated xylene diisocyanate, dicyclohexanemethylene diisocyanate, and polyisocyanates such as their isocyanurates and biuret reaction products.

[0127] Other alcohols include, for example, tricyclodecanedimethanol, hydrogenated polybutadiene polyol, dimergol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, 1,16-hexadecanediol, 1,18-octadecanediol, 1,20-icosanediol, 1-methyl-1,8- Examples include octanediol, 2-methyl-1,8-octanediol, 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, cyclohexane-1,4-dimethanol, polyethylene glycol, polypropylene glycol, diols such as bisphenol A poly(n≒2-20)ethoxydiol and bisphenol A poly(n≒2-20)propoxydiol, and polyester polyols which are reaction products of these diols with dibasic acids or their anhydrides (e.g., succinic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, isophthalic acid, terephthalic acid, phthalic acid, or their anhydrides).

[0128] Examples of polyester (meth)acrylates include monofunctional (poly)ester (meth)acrylates such as caprolactone-modified 2-hydroxyethyl (meth)acrylate, ethylene oxide and / or propylene oxide-modified phthalic acid (meth)acrylate, ethylene oxide-modified succinic acid (meth)acrylate, and caprolactone-modified tetrahydrofurfuryl (meth)acrylate; polyfunctional (poly)ester (meth)acrylates such as hydroxypivalate ester neopentyl glycol di(meth)acrylate, caprolactone-modified hydroxypivalate ester neopentyl glycol di(meth)acrylate, and epichlorohydrin-modified phthalic acid di(meth)acrylate; and mono, di, or tri(meth)acrylates of triols obtained by adding 1 mole or more of cyclic lactone compounds such as ε-caprolactone, γ-butyrolactone, and δ-valerolactone to 1 mole of trimethylolpropane or glycerin.

[0129] Furthermore, examples include (meth)acrylates of polyester polyols, which are reaction products of diol components such as (poly)ethylene glycol, (poly)propylene glycol, (poly)tetramethylene glycol, (poly)butylene glycol, 3-methyl-1,5-pentanediol, and hexanediol with polybasic acids such as maleic acid, fumaric acid, succinic acid, adipic acid, phthalic acid, isophthalic acid, hexahydrophthalic acid, tetrahydrophthalic acid, dimer acid, sebacic acid, azelaic acid, and 5-sodium sulfoisophthalic acid, and their anhydrides; and (meth)acrylates of cyclic lactone-modified polyester diols, which consist of diol components, polybasic acids, and their anhydrides with ε-caprolactone, γ-butyrolactone, δ-valerolactone, etc.

[0130] Examples of epoxy (meth)acrylates include reaction products of the aforementioned epoxy resin with compounds that contain both polymerizable ethylenically unsaturated groups and carboxyl groups in a single molecule.

[0131] Examples of compounds that contain both polymerizable ethylenically unsaturated groups and carboxyl groups in a single molecule include (meth)acrylic acids, crotonic acid, α-cyanocinnamic acid, cinnamic acid, or reaction products of saturated or unsaturated dibasic acids with unsaturated group-containing monoglycidyl compounds. Examples of acrylic acids include (meth)acrylic acid, β-styrylacrylic acid, β-furfurylacrylic acid, (meth)acrylic acid dimers, semi-esters which are equimolar reaction products of saturated or unsaturated dibasic acid anhydrides with (meth)acrylate derivatives having one hydroxyl group per molecule, and semi-esters which are equimolar reaction products of saturated or unsaturated dibasic acids with monoglycidyl (meth)acrylate derivatives.

[0132] Furthermore, examples of polycarboxylic acid compounds having multiple carboxyl groups in a single molecule include semi-esters which are equimolar reaction products with (meth)acrylate derivatives having multiple hydroxyl groups in a single molecule, and semi-esters which are equimolar reaction products with saturated or unsaturated dibasic acids and glycidyl (meth)acrylate derivatives having multiple epoxy groups.

[0133] Acid-modified (meth)acrylates are those obtained by reacting all or part of the alcoholic hydroxyl groups of a (meth)acrylate, which has alcoholic hydroxyl groups, with a carboxylic acid or its anhydride to introduce carboxyl groups. Examples of carboxylic acids or their anhydrides include succinic acid, maleic acid, isophthalic acid, terephthalic acid, tetrahydroisophthalic acid, hexahydroisophthalic acid, itaconic acid, 3-methyltetrahydroisophthalic acid, 4-methylhexahydroisophthalic acid, hydrogenated trimellitic acid, trimellitic acid, allylsuccinic acid, citraconic acid, methylsuccinic acid, 2,2-dimethylsuccinic acid, pentadecenylsuccinic acid, dodecenylsuccinic acid, decylsuccinic acid, dodecylsuccinic acid, hexadecylsuccinic acid, octadecylsuccinic acid, bicyclo[2.2.2]octo-2-ene-2,3-dicarboxylic acid, succinic anhydride, maleic anhydride, and phthalic acid anhydride. Examples include aqueous solutions, tetrahydroisophthalic anhydride, hexahydroisophthalic anhydride, itaconic anhydride, 3-methyl-tetrahydroisophthalic anhydride, 4-methyl-hexahydroisophthalic anhydride, hydrogenated trimellitic anhydride, trimellitic anhydride, allylsuccinic anhydride, citraconic anhydride, methylsuccinic anhydride, 2,2-dimethylsuccinic anhydride, pentadecenylsuccinic anhydride, dodecenylsuccinic anhydride, decylsuccinic anhydride, dodecylsuccinic anhydride, hexadecylsuccinic anhydride, octadecylsuccinic anhydride, and bicyclo[2.2.2]octo-2-ene-2,3-dicarboxylic acid anhydride.

[0134] Compounds having an acenaphthyl group are not limited to the following disclosures, but include, for example, acenaphthylene, 1-methylacenaphthylene, 3-methylacenaphthylene, 4-methylacenaphthylene, 5-methylacenaphthylene, 1-ethylacenaphthylene, 3-ethylacenaphthylene, 4-ethylacenaphthylene, 5-ethylacenaphthylene, 5-propylacenaphthylene, 3,8-dimethylacenaphthylene, 5,6-dimethylacenaphthylene, 1-chloroacenaphthylene, 3-chloroacenaphthylene, 4-chloroacenaphthylene, 5-chloroacenaphthylene Examples include phthalene, 1-bromoacenaphthalene, 3-bromoacenaphthalene, 4-bromoacenaphthalene, 5-bromoacenaphthalene, 1-phenylacenaphthalene, 3-phenylacenaphthalene, 4-phenylacenaphthalene, 5-phenylacenaphthalene, 3-methoxyacenaphthalene, 3-ethoxyacenaphthalene, 3-butoxyacenaphthalene, 4-methoxyacenaphthalene, 4-ethoxyacenaphthalene, 4-butoxyacenaphthalene, 5-methoxyacenaphthalene, 5-ethoxyacenaphthalene, and 5-butoxyacenaphthalene.

[0135] Compounds having an indenyl group include, but are not limited to, indene, methyl indene, ethyl indene, propyl indene, butyl indene, t-butyl indene, sec-butyl indene, n-pentyl indene, 2-methyl-butyl indene, 3-methyl-butyl indene, n-hexyl indene, 2-methyl-pentyl indene, 3-methyl-pentyl indene, 4-methyl-pentyl indene, methoxy indene, ethoxy indene, butoxy indene, t-butoxy indene, sec-butoxy indene, n-pentoxy indene, 2-methyl-butoxy indene, 3-methyl-butoxy indene, n-hexoxy indene, 2-methyl-pentoxy indene, 3-methyl-pentoxy indene, and 4-methyl-pentoxy indene.

[0136] Compounds having a citracomide group include, but are not limited to, o-phenylenebiscitraconimide, m-phenylenebiscitraconimide, p-phenylenebiscitraconimide, 4,4-diphenylmethanebiscitraconimide, 2,2-bis[4-(4-citraconimidophenoxy)phenyl]propane, bis(3,5-dimethyl-4-citraconimidophenyl)methane, bis(3-ethyl-5-methyl-4-citraconimidophenyl)methane, and bis(3,5-diethyl-4-citraconimidophenyl)methane.

[0137] Compounds having an itaconiamide group include, but are not limited to, N-methylitaconimide, N-ethylitaconimide, N-butylitaconimide, N-octylitaconimide, N-2-ethylhexylitaconimide, N-cyclohexylitaconimide, and N-laurylitaconimide.

[0138] Compounds having a nadiimide group include, but are not limited to, the following disclosures, 5-norbornene-2,3-dicarboxylic acid imide (so-called nadiimide), N-methylnadiimide, N-phenylnadiimide, o-phenylenebisnadiimide, m-phenylenebisnadiimide, p-phenylenebisnadiimide, 4,4'-diphenylmethanebisnadiimide, 2,2-bis[4-(4-nadiimoidphenoxy)phenyl]propane, bis(3,5-dimethyl-4-nadiimoidphenyl)methane, bis(3-ethyl-5-methyl-4-nadiimoidphenyl)methane, and bis(3,5-diethyl-4-nadiimoidphenyl)methane.

[0139] Compounds having an arylnadiimide group include, but are not limited to, the following disclosures, N-arylnadiimide (N-allyl-5-norbornene-2,3-dicarboxylic acid imide), N-allyl-N-methylnadiimide, N-allyl-N-phenylnadiimide, o-phenylenebis(N-arylnadiimide), m-phenylenebis(N-arylnadiimide), p-phenylenebis(N-arylnadiimide), 4,4'-diphenylmethanebis(N-arylnadiimide), 2,2-bis[4-(4-N-arylnadiimoidphenoxy)phenyl]propane, bis(3,5-dimethyl-4-N-arylnadiimoidphenyl)methane, and bis(3-ethyl-5-methyl-4-N-arylnadiimoidphenyl)methane.

[0140] Compounds having a cyclopentadienyl group include, but are not limited to, 1,3-cyclopentadiene, 1-methyl-1,3-cyclopentadiene, 2-methyl-1,3-cyclopentadiene, 1,2,3,4-tetramethyl-1,3-cyclopentadiene, and 1,2,3,4,5-pentamethyl-1,3-cyclopentadiene.

[0141] [Benzoxazine Compounds] As benzoxazine compounds, any compound having two or more dihydrobenzoxazine rings in one molecule can be used, as long as it is generally known. Examples include bisphenol A type benzoxazine BA-BXZ (manufactured by Konishi Chemical Co., Ltd.), bisphenol F type benzoxazine BF-BXZ (manufactured by Konishi Chemical Co., Ltd.), bisphenol S type benzoxazine BS-BXZ (manufactured by Konishi Chemical Co., Ltd.), phenolphthalein type benzoxazine, etc., but are not particularly limited. These benzoxazine compounds can be used individually or in appropriate mixtures of two or more.

[0142] The curable resin composition of this embodiment is obtained by preparing the above components in predetermined proportions, pre-curing at 130 to 180°C for 30 to 500 seconds, and then post-curing at 150 to 200°C for 2 to 15 hours to allow the curing reaction to proceed sufficiently and obtain the cured product of this embodiment. Alternatively, the components of the curable resin composition can be uniformly dispersed or dissolved in a solvent, and then cured after removing the solvent.

[0143] The method for preparing the curable resin composition of this embodiment is not particularly limited, but each component may be uniformly mixed or prepolymerized. For example, a mixture of the maleimide resin and copolymer of this embodiment can be prepolymerized by heating in the presence or absence of a curing accelerator and polymerization initiator, and in the presence or absence of a solvent. Similarly, compounds such as amine compounds, compounds having ethylenically unsaturated bonds, maleimide resin, cyanate ester compounds, polybutadiene and its modified products, polystyrene and its modified products, inorganic fillers, and other additives may be added and prepolymerized. Mixing or prepolymerizing each component can be done using, for example, an extruder, kneader, or roll in the absence of a solvent, and using a reaction vessel with a stirring device in the presence of a solvent.

[0144] For uniform mixing, the resin composition is kneaded using equipment such as a kneader, roll, or planetary mixer at a temperature in the range of 50 to 100°C. After pulverization, the resulting resin composition can be molded into cylindrical tablets using a molding machine such as a tablet machine, or into granular powder or powdery molded bodies. Alternatively, these compositions can be melted on a surface support and molded into sheets with a thickness of 0.05 mm to 10 mm to produce curable resin composition molded bodies. The resulting molded bodies are non-sticky at 0 to 20°C and maintain their fluidity and curability with almost no decrease even after storage at -25 to 0°C for more than a week. The resulting molded bodies can be molded into cured products using a transfer molding machine or a compression molding machine.

[0145] The curable resin composition of this embodiment can also be made into a varnish-like composition (hereinafter simply referred to as varnish) by adding an organic solvent. 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 make 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 the resulting prepreg can be obtained by heat-drying and then hot-press-molding to obtain a cured product of the curable resin composition of this embodiment. In this case, the solvent used is in an amount that accounts for 10 to 70% by weight, preferably 15 to 70% by weight, of the mixture of the curable resin composition of this embodiment and the solvent. If it is a liquid composition, a cured product of the curable resin composition containing carbon fibers can also be obtained directly, for example, by the RTM method.

[0146] Furthermore, the curable resin composition of this embodiment can also be used as a modifier for film-type compositions. Specifically, it can be used to improve flexibility and other properties in the B-stage. Such a film-type resin composition can be obtained as a sheet-like adhesive by applying the curable resin composition of this embodiment as a curable resin composition varnish onto a release film, removing the solvent under heating, and then performing B-stage formation. This sheet-like adhesive can be used as an interlayer insulating layer in multilayer substrates and the like.

[0147] The curable resin composition of this embodiment can also be heated and melted to reduce viscosity and impregnate reinforcing fibers such as glass fibers, carbon fibers, polyester fibers, polyamide fibers, and alumina 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, as well as inorganic fibers other than glass, and organic fibers such as poly(p-phenylene terephthalamide) (Kevlar®, manufactured by DuPont), fully aromatic polyamide, polyester, poly(p-phenylene benzoxazole), polyimide, and carbon fibers. The shape of the substrate is not particularly limited, but examples include woven fabrics, nonwoven fabrics, rovings, and chopped strand mats. As for the weaving method of the woven fabric, plain weave, twill weave, etc., are known, and these can be appropriately selected and used depending on the intended application and performance. Furthermore, glass woven fabrics that have been opened or surface-treated with silane coupling agents are preferably used. The thickness of the base material is not particularly limited, but is preferably about 0.01 to 0.4 mm. Alternatively, a prepreg can be obtained by impregnating reinforcing fibers with the above varnish and then heating and drying them.

[0148] Furthermore, laminates can also be manufactured using the above-mentioned prepregs. The laminate is not particularly limited as long as it comprises one or more prepregs, and may have any other layers. The method for manufacturing the laminate is not particularly limited and can be any generally known method as appropriate. For example, when forming a metal foil laminate, a multi-stage press, a multi-stage vacuum press, a continuous molding machine, an autoclave molding machine, etc., can be used, and a laminate can be obtained by laminating the above-mentioned prepregs together and then heating and pressing them. At this time, the heating temperature is not particularly limited, but 65 to 300°C is preferred, and 120 to 270°C is more preferred. The pressurizing pressure is not particularly limited, but if the pressurizing pressure is too high it is difficult to adjust the solid content of the resin in the laminate and the quality is not stable, and if the pressurizing pressure is too low it becomes difficult to form air bubbles and the adhesion between layers is poor, so 2.0 to 5.0 MPa is preferred, and 2.5 to 4.0 MPa is more preferred. The laminate of this embodiment can be suitably used as a metal foil laminate described later by comprising a layer made of metal foil. By cutting the above prepreg into the desired shape, laminating it with copper foil or other materials as needed, and then applying pressure to the laminate using methods such as press molding, autoclave molding, or sheet winding molding while heating and curing a curable resin composition, electrical and electronic laminates (printed wiring boards) and carbon fiber reinforced materials can be obtained.

[0149] The curable resin composition of this embodiment can also be made into a resin sheet. One method for obtaining a resin sheet from the curable resin composition of this embodiment is to apply the curable resin composition onto a support film (support), and then dry it to form a resin composition layer on the support film. When using the curable resin composition of this embodiment to make a resin sheet, it is important that the film softens at the lamination temperature conditions (70°C to 140°C) in the vacuum lamination method and exhibits fluidity (resin flow) that allows for simultaneous lamination of the circuit board and resin filling of via holes or through holes present in the circuit board. It is preferable to blend the above components in such a way as to exhibit such characteristics. Furthermore, in order to ensure that the resulting resin sheet and circuit board (copper-clad laminate, etc.) exhibit consistent performance in any desired area, and to prevent phenomena such as locally different characteristic values ​​caused by phase separation, uniformity of appearance is required.

[0150] Here, the diameter of the through-holes in the circuit board is 0.1 to 0.5 mm, and the depth is 0.1 to 1.2 mm. It is preferable to be able to fill the holes with resin within this range. When laminating both sides of the circuit board, it is desirable that the through-holes be filled to about half their extent.

[0151] A specific method for manufacturing the above-mentioned resin sheet is to prepare a varnished resin composition by incorporating an organic solvent, apply the varnished resin composition to the surface of a support film (Y), and then dry the organic solvent by heating or blowing hot air to form a resin composition layer (X).

[0152] The organic solvents used here preferably include ketones such as acetone, methyl ethyl ketone, and cyclohexanone; acetic acid esters such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; dimethylformamide, dimethylacetamide, and N-methylpyrrolidone. It is also preferable to use them in a proportion that results in a non-volatile content of 30 to 60% by mass.

[0153] Furthermore, the thickness of the formed resin composition layer (X) must be greater than or equal to the thickness of the conductor layer. Since the thickness of the conductor layer of the circuit board is in the range of 5 to 70 μm, it is preferable that the thickness of the resin composition layer (X) be 10 to 100 μm. In this embodiment, the resin composition layer (X) may be protected by a protective film, which will be described later. By protecting it with a protective film, it is possible to prevent dirt and other debris from adhering to the surface of the resin composition layer and to prevent scratches.

[0154] The above-mentioned support film and protective film can be made of polyolefins such as polyethylene, polypropylene, and polyvinyl chloride, polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate, polycarbonate, polyimide, and also release paper, copper foil, aluminum foil, and other metal foils. The support film and protective film may be treated with a mat treatment, corona treatment, or release treatment. The thickness of the support film is not particularly limited, but is 10 to 150 μm, preferably in the range of 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0155] The support film (Y) described above is peeled off after lamination to the circuit board or after an insulating layer has been formed by heat curing. If the support film (Y) is peeled off after the resin composition layer constituting the resin sheet has been heat cured, it is possible to prevent the adhesion of dust and other debris during the curing process. When peeling off after curing, the support film is treated with a release agent beforehand.

[0156] Furthermore, a multilayer printed circuit board can be manufactured from the resin sheet obtained as described above. For example, if the resin composition layer (X) is protected by a protective film, these are removed, and then the resin composition layer (X) is laminated to one or both sides of the circuit board so that it is in direct contact with the circuit board, for example, by a vacuum lamination method. The lamination method may be batch or continuous on a roll. If necessary, the resin sheet and circuit board may be heated (preheated) before lamination. The lamination conditions are preferably a pressure temperature (lamination temperature) of 70 to 140°C and a pressure of 1 to 11 kgf / cm². ２ (9.8 x 10 ４ ~107.9 x 10 ４ N / m ２ It is preferable to use this method, and it is preferable to laminate under reduced pressure of 20 mmHg (26.7 hPa) or less.

[0157] Furthermore, semiconductor devices can be manufactured using the curable resin composition of this embodiment. Examples of semiconductor devices include DIP (Dual In-Line Package), QFP (Quad Flat Package), BGA (Ball Grid Array), CSP (Chip Size Package), SOP (Small Outline Package), TSOP (Thin Small Outline Package), and TQFP (Thin Quad Flat Package).

[0158] The curable resin composition and its cured product according to this embodiment can be used in a wide range of fields. Specifically, it can be used in various applications such as molding materials, adhesives, composite materials, and paints. Because the cured product of the curable resin composition described in this embodiment exhibits excellent heat resistance and dielectric properties, it is suitably used in electrical and electronic components such as encapsulants for semiconductor devices, encapsulants for liquid crystal display devices, encapsulants for organic EL devices, laminates (printed wiring boards, BGA substrates, build-up substrates, etc.), composite materials for lightweight, high-strength structural materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and 3D printing.

[0159] Next, the present invention will be described in more detail with reference to examples. Hereinafter, unless otherwise specified, parts refer to parts by mass. However, the present invention is not limited to these examples.

[0160] The various analytical methods used in the examples are described below. [Synthesis Examples 1, 2, 5] Column: Super HZM-N Eluent: THF (tetrahydrofuran); 0.35 ml / min, 40°C Detector: RI (differential refractometer) Molecular weight standard: Polystyrene

[0161] [Synthesis Examples 3 and 4] Columns: SHODEX GPC KF-601 (2 tubes), KF-602, KF-602.5, KF-603 Eluent: THF (tetrahydrofuran); 0.5 ml / min, 40°C Detector: RI (differential refractometer) Molecular weight standard: Polystyrene

[0162] [Synthesis Example 1] Synthesis of maleimide resin (A-1) having at least one structure represented by the above formula (1) in its molecule, with a maleimide equivalent of 730 g / eq. or less. 110 g of toluene and 36 g of N-methylpyrrolidone were placed in a 500 ml round-bottom flask equipped with a Teflon®-coated stirring bar. Next, 85.6 g (0.16 mol) of PRIAMINE 1074 (manufactured by Croda Japan Co., Ltd.) was added, followed by the slow addition of 15.4 g (0.16 mol) of methanesulfonic anhydride to form a salt. The mixture was stirred for approximately 10 minutes, and then 1,2,4,5-cyclohexanetetracarboxylic dianhydride (24.5 g, 0.08 mol) was slowly added to the stirred mixture. A Dean-Stark trap and condenser were attached to the flask. The mixture was heated under reflux for 6 hours to form an amine-terminated diimide. The theoretical amount of water produced from this condensation was obtained by this point. The reaction mixture was cooled to below room temperature, and 18.8 g (0.19 mol) of maleic anhydride was added to the flask. The mixture was refluxed for a further 8 hours to obtain the expected amount of water produced. After cooling to room temperature, 200 ml of toluene was added to the flask. Next, the diluted organic layer was washed with water (100 ml x 3 times) to remove salts and unreacted starting materials. The solvent was then removed under vacuum to obtain 108 g of amber-colored, waxy maleimide resin (A-1) (yield 90%, Mw = 3,058). The maleimide equivalent was measured by the method described in Japanese Patent Publication No. 2020-187012 and was 720 g / eq. The GPC chart is shown in Figure 1.

[0163] [Synthesis Example 2] Synthesis of maleimide resin (A-2) having at least one structure represented by the above formula (1) in its molecule, with a maleimide equivalent of 730 g / eq. or less. 466.0 g of toluene and 466.0 g of N-methylpyrrolidone were added to a 1 L round-bottom flask equipped with a thermometer, reflux condenser, Dean-Stark apparatus, powder inlet, nitrogen inlet, and stirrer. Next, 66.2 g (0.20 mol) of diamine H2O and 284.9 g (1.80 mol) of norbornanediamine were added, followed by the slow addition of 192.2 g (2.0 mol) of methanesulfonic acid to form a salt. The mixture was stirred for approximately 10 minutes, and then 624.1 g (1.20 mol) of BISDA-1000 was slowly added to the stirred mixture. The mixture was refluxed at 140°C for 6 hours to confirm that the theoretical amount of water produced from this condensation had been removed, and an amine-terminated diimide was obtained. The reaction mixture was cooled to below room temperature, and 188.3 g (1.92 mol) of maleic anhydride was added. The mixture was further refluxed at 140°C for 8 hours to obtain the expected amount of water produced. After cooling to room temperature, 500 ml of toluene was added to the flask, and the diluted organic layer was washed with water (500 ml x 5 times) to remove salts and unreacted starting materials to obtain a varnish of the bismaleimide compound. Subsequently, the varnish was reprecipitation by dropping it into 5,000 g of methanol, and after removing the solvent and drying, 960 g (yield 91%, Mw = 3,975) of the desired white solid maleimide resin (A-2) was obtained. The maleimide equivalent was measured by the method described in Japanese Patent Publication No. 2020-187012 and was 660 g / eq. The GPC chart is shown in Figure 2.

[0164] [Synthesis Example 3] Synthesis of Aromatic Amine Resin (B-1) 192 parts aniline, 112 parts toluene, and 100 parts 1,3-bis(2-hydroxy-2-propyl)benzene were charged into a flask equipped with a thermometer, condenser, Dean-Stark azeotropic distillation trap, and stirrer, and 21.5 parts 35% hydrochloric acid was added dropwise over 10 minutes. The system was heated to 160°C, and the reaction was carried out at the same temperature for 17 hours while removing water and toluene by distillation. After cooling to 80°C, 124 parts toluene was added, and 30 parts 30% sodium hydroxide aqueous solution was added dropwise over 10 minutes. The mixture was then stirred at the same temperature for 2 hours and allowed to stand for 30 minutes. The separated aqueous layer was removed, and the reaction solution was washed with water repeatedly until the washing solution was neutral. Then, 158 parts of aromatic amine resin (B-1) were obtained by distilling off excess aniline and toluene from the oil layer under reduced pressure using a rotary evaporator. The aromatic amine resin (B-1) had an amine equivalent of 186.1 g / eq. and a softening point of 58.8°C. GPC analysis (RI) revealed that the n=1 compound represented 62.5 area %. The GPC chart is shown in Figure 3.

[0165] [Synthesis Example 4] Synthesis of Maleimide Resin (B-2) A flask equipped with a thermometer, condenser, Dean-Stark azeotropic distillation trap, and stirrer was charged with 73.5 parts maleic anhydride, 126 parts toluene, 1.86 parts methanesulfonic acid, and 12.6 parts N-methyl-2-pyrrolidone, and heated under reflux. Next, a resin solution prepared by dissolving 93 parts aromatic amine resin (B-1) in 55.8 parts toluene was added dropwise over 4 hours while maintaining reflux. During this time, the condensed water and toluene that formed azeotropically under reflux conditions were cooled and separated in the Dean-Stark azeotropic distillation trap. The toluene, which is the organic layer, was returned to the system, and the water was discharged from the system. After the addition of the resin solution was completed, the reaction was carried out for 10 hours while maintaining reflux and performing dehydration. After the reaction was completed, the mixture was washed with water four times to remove methanesulfonic acid and excess maleic anhydride, and the water was removed from the system by azeotropy of toluene and water under reduced pressure at a temperature below 70°C. Next, 0.93 parts of methanesulfonic acid were added, and the reaction was carried out under reflux for 4 hours. After the reaction was complete, the mixture was washed with water four times until the washing water became neutral. Then, water was removed from the system by azeotrope of toluene and water under reduced pressure and heating below 70°C. After that, the solvent was removed by distillation of toluene under reduced pressure and heating until the resin concentration was approximately 70-80%, and then toluene was added to adjust the resin concentration to 60%. This yielded a maleimide solution (V-1) containing maleimide resin (B-2). GPC analysis (RI) of the obtained maleimide resin (B-2) showed that the n=1 isomer was 57.4 area%, the n=2 isomer was 21.3 area%, and the n=3 or more isomers were 21.3 area%. The orientation ratio (ortho-ortho isomer / para-para isomer / ortho-para isomer) in the n=1 isomer was 32.0 area% / 25.4 area% / 42.6 area% by HPLC analysis (225 nm). Furthermore, the softening point was 115.5°C, and the viscosity at 150°C was 6.0 Pa·s. The maleimide equivalent was measured by the method described in Japanese Patent Publication No. 2020-187012 and was 311 g / eq. The GPC chart is shown in Figure 4.

[0166] [Synthesis Example 5] Synthesis of a maleimide resin (A-3) having at least one structure represented by the above formula (1) in its molecule, with a maleimide equivalent of 730 g / eq. or less. 386.9 g of isocyanurate-modified hexamethylene diisocyanate (Asahi Kasei Corporation's "Duranate TPA-100", isocyanate group content 22.7% by mass), 327.5 g of N-methylpyrrolidone, and 764.1 g of toluene were added as isocyanate compounds. The temperature was raised to 80°C while blowing nitrogen into the system, and 250.9 g of maleic acid was added little by little as a polybasic acid, and the reaction was carried out at 80°C for 8 hours. The characteristic absorption of the isocyanate group was 2250 cm⁻¹ in the infrared spectrum. －１ The absorption of the ammonium compound was completely eliminated, and the acid value of the reaction solution was confirmed to be within plus or minus 5% of the target value, confirming that an amic acid-containing compound had been obtained. Subsequently, 1.50 g of dibutylhydroxytoluene was added as a polymerization inhibitor, and 134.0 g of methanesulfonic acid was added as a catalyst. The temperature was raised, and a reflux dehydration reaction was carried out for 14 hours, after which it was cooled. Toluene was added to the obtained solution, and the aqueous layer was washed with deionized water until the pH of the aqueous layer was 5 or higher. The organic layer was dried under reduced pressure to obtain 352 g (70% yield) of the target compound (A-3), which was a pale yellow viscous liquid. The weight-average molecular weight Mw determined by GPC analysis was 1,109, and the acid value of the obtained compound was 7.4 mg·KOH / g. The molecular weight was 666, and the number of functional groups was 3, resulting in a maleimide equivalent of 222 g / eq. The GPC chart is shown in Figure 5.

[0167] [Synthesis Example 6] Synthesis of maleimide resin (A-4) having at least one structure represented by the above formula (1) in its molecule, with a maleimide equivalent of 730 g / eq. or less. 120 g of toluene and 40 g of N-methylpyrrolidone were placed in a 500 ml round-bottom flask equipped with a fluororesin-coated stirring bar. Next, 92.2 g (0.68 mol) of m-xylenediamine (product name: MXDA, manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added, followed by the slow addition of 65.3 g (0.68 mol) of methanesulfonic acid to form a salt. The mixture was stirred for 10 minutes and then 160.8 g (1.64 mol) of maleic anhydride was slowly added to the stirred mixture. A Dean-Stark trap and condenser were attached to the flask. The mixture was heated under reflux for 8 hours to obtain the expected amount of product water. After cooling to room temperature, 200 ml of toluene was added to the flask. Next, the diluted organic layer was washed with water (100 ml x 3 times) to remove salts and unreacted starting materials. The solvent was then removed under vacuum to obtain 181.1 g (90% yield) of a pale yellow powdery bismaleimide compound. With a molecular weight of 296 and 2 functional groups, the maleimide equivalent was 148 g / eq.

[0168] • Maleimide resin BMI-1500 (manufactured by Designer Molecules Inc., molecular weight 1504, number of functional groups 2, maleimide equivalent 752 g / eq.) BMI-3000J (manufactured by Designer Molecules Inc., molecular weight 3000, number of functional groups 2, maleimide equivalent 1500 g / eq.) • Copolymer Snekton S-700 (development product number: LDM03-07) (manufactured by Denka Co., Ltd., ethylene-styrene-divinylbenzene copolymer, Mn was 7000.) • Curing accelerator DCP (manufactured by Kayaku Nurion Co., Ltd., dicumyl peroxide)

[0169] [Examples 1-5, Comparative Examples 1-3] [Preparation of Cured Products] Each material was measured out in the proportions (parts by mass) shown in Tables 1 and 2, and a mixed solvent of toluene / acetone = 3 / 1 (mass%) was added to achieve a resin solids content of 50% by mass. The mixture was then mixed to prepare a varnish. The varnish was heated in a vacuum dryer at 80°C for 30 minutes and then at 100°C for 30 minutes to prepare a curable resin composition. The obtained curable resin composition was sandwiched between copper foils and cured under vacuum at a pressure of 1 MPa at 220°C for 2 hours.

[0170] <Dielectric Constant Test and Dielectric Loss Tangent Test> Tests were performed using a 10 GHz cavity resonator manufactured by AET Co., Ltd. at 25°C using the cavity resonator perturbation method. Furthermore, the test specimens were left in an oven at 150°C under atmospheric conditions for 168 hours, and measurements were taken again. Using the obtained results, the rate of change after oxidation was calculated using the following formula: Rate of change of Df after 168h oxidation [%] = {(Df after 168h oxidation [-] - initial Df [-]) / initial Df [-]} × 100 The sample size was 2.5 mm wide × 50 mm long, and the test was performed with a thickness of 0.25 mm.

[0171] <Water Absorption Test> The water absorption rate was calculated by measuring the weight after immersion in water for 24 hours, followed by removal and leaving it in a 25°C, 30% humidity environment for 24 hours.

[0172] <Copper Foil Adhesion Test> The curable resin composition obtained by the method described above was sandwiched between the rough sides of a 35 μm copper foil and an 18 μm copper foil, and cured at 220°C for 2 hours under a vacuum pressure of 1 MPa. The obtained sample was cut into 2 cm widths, and then the 18 μm copper foil side was cut to a width of 1 cm to prepare a measurement sample. Using a Shimadzu Autograph AGS-X500N, the 1 cm width copper foil was sandwiched and the test was performed by pulling it in the 90° direction at a speed of 25 mm / min.

[0173]

[0174]

[0175] As is clear from Tables 1 and 2, Comparative Examples 1 and 2 showed good dielectric properties, but after 168 hours of heating, the dielectric properties deteriorated significantly. Examples 1 to 4 showed relatively good dielectric properties not only initially but also after 168 hours of heating. Comparing Example 5 with Comparative Example 3, Example 5 showed good dielectric properties both initially and after 168 hours of heating, as well as good water absorption and copper foil adhesion.

[0176] The curable resin composition of the present invention is suitably used in electrical and electronic components such as semiconductor encapsulants, printed circuit boards, build-up laminates, and optical waveguide devices, as well as lightweight, high-strength materials such as carbon fiber reinforced plastics and glass fiber reinforced plastics, and in 3D printing applications.

[0177] [Note] As described above, this embodiment includes the following disclosures.

[0178] [1] A curable resin composition comprising a maleimide resin having a maleimide equivalent of 730 g / eq. or less and having at least one structure represented by the following formula (1) in its molecule, and a copolymer containing ethylene, styrene, and divinylbenzene.

[0179]

[0180] (In formula (1), Al is an aliphatic hydrocarbon group having 1 to 60 carbon atoms.) [2] The curable resin composition according to [1], wherein the maleimide equivalent of the maleimide resin is 100 g / eq. to 300 g / eq. [3] The curable resin composition according to [1] or [2], wherein the maleimide resin is represented by the following formula (4).

[0181]

[0182] (In formula (4), R ６ (wherein is an aliphatic hydrocarbon group having 1 to 60 carbon atoms, and Z represents an organic group. p represents an integer from 2 to 4.) [4] The curable resin composition according to any one of [1] to [3], wherein the maleimide resin is obtained by reacting a diamine having 4 to 60 carbon atoms with a tetracarboxylic dianhydride represented by the following formula (2) and a maleic anhydride.

[0183]

[0184] (In equation (2), A is a structure represented by any of the following equations (1-a) to (1-u).)

[0185]

[0186] (In formulas (1-a) to (1-u), the dashed lines represent bonding with the acid anhydride group in formula (2).) [5] A curable resin composition according to any one of [1] to [4], wherein the structure represented by A in formula (2) is (1-f) or (1-l). [6] A curable resin composition according to any one of [1] to [5], wherein the maleimide resin is represented by the following formula (3). (In formula (3), R １ , R ２ , R ３ R indicates a divalent hydrocarbon group, ４ and R ５ This represents one or more organic groups selected from: a tetravalent organic group having 4 to 40 carbon atoms and independently having a monocyclic or condensed polycyclic alicyclic structure; a tetravalent organic group having 8 to 40 carbon atoms in which organic groups having a monocyclic alicyclic structure are linked to each other directly or via a cross-linking structure; and a tetravalent organic group having 8 to 40 carbon atoms and having a semi-alicyclic structure possessing both an alicyclic structure and an aromatic ring. m is an integer from 1 to 30, n is an integer from 0 to 30, and R ４ and R ５ (These may be the same or different.) [7] A curable resin composition according to any one of [1] to [6], wherein the content of the copolymer is 1% to 50% by mass in the total amount of the curable resin composition. [8] A curable resin composition according to any one of [1] to [7], further comprising a curing accelerator, a polymerization initiator, an 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 resin other than the maleimide resin, a cyanate ester resin, a polyimide resin, a polybutadiene and a modified product thereof, a polystyrene and a modified product thereof, a polyethylene and a modified product thereof, and a benzoxazine compound. [9] A cured product obtained by curing the curable resin composition according to any one of [1] to [8].

Claims

1. A curable resin composition containing a maleimide resin having a maleimide equivalent of 730 g / eq or less and having at least one or more structures represented by the following formula (1) in the molecule, and a copolymer containing ethylene, styrene, and divinylbenzene. (In formula (1), Al is an aliphatic hydrocarbon group having 1 to 60 carbon atoms.) 2. The curable resin composition according to claim 1, wherein the maleimide equivalent of the maleimide resin is 100 g / eq. to 300 g / eq.

3. The curable resin composition according to claim 1, wherein the maleimide resin is represented by the following formula (4). (In formula (4), R ６ (where is an aliphatic hydrocarbon group with 1 to 60 carbon atoms, Z indicates an organic group, and p represents an integer between 2 and 4.) 4. The curable resin composition according to claim 1, wherein the maleimide resin is obtained by reacting a diamine having 4 to 60 carbon atoms with a tetracarboxylic dianhydride represented by the following formula (2) and a maleic anhydride. (In equation (2), A is a structure represented by any of the following equations (1-a) to (1-u).) (In formulas (1-a) to (1-u), the dashed lines represent the bond with the acid anhydride group in formula (2) above.) 5. The curable resin composition according to claim 4, wherein the structure represented by A in formula (2) is (1-f) or (1-l) as described above.

6. The curable resin composition according to claim 1, wherein the maleimide resin is represented by the following formula (3). (In formula (3), R １ , R ２ , R ３ R indicates a divalent hydrocarbon group, ４ and R ５ This represents one or more organic groups selected from: a tetravalent organic group having 4 to 40 carbon atoms and independently having a monocyclic or condensed polycyclic alicyclic structure; a tetravalent organic group having 8 to 40 carbon atoms in which organic groups having a monocyclic alicyclic structure are linked to each other directly or via a cross-linking structure; and a tetravalent organic group having 8 to 40 carbon atoms and having a semi-alicyclic structure possessing both an alicyclic structure and an aromatic ring. m is an integer from 1 to 30, n is an integer from 0 to 30, and R ４ and R ５ (These may be the same or different.) 7. The curable resin composition according to claim 1, wherein the content of the copolymer is 1% by mass to 50% by mass of the total amount of the curable resin composition.

8. The curable resin composition according to claim 1, further comprising at least one selected from a curing accelerator, polymerization initiator, epoxy resin, active ester compound, phenol resin, polyphenylene ether compound, amine resin, compound having an ethylenically unsaturated bond, isocyanate resin, polyamide resin, maleimide resin other than the maleimide resin, cyanate ester resin, polyimide resin, polybutadiene and modified thereof, polystyrene and modified thereof, polyethylene and modified thereof, and benzoxazine compound.

9. A cured product obtained by curing the curable resin composition according to any one of claims 1 to 8.

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