Resin composition, prepreg, resin-coated film, resin-coated metal foil, metal-clad laminate, and wiring board

Abstract

One aspect of the present application relates to a resin composition comprising: a pre-reaction product (A) obtained by previously reacting a mixture comprising a polyfunctional vinyl aromatic copolymer (a1) containing a repeating unit derived from a divinyl aromatic compound and a maleimide compound (a2) having an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms.

Description

Technical Field

[0001] This invention relates to resin compositions, prepregs, resin-coated films, resin-coated metal foils, metal foil-coated laminates, and wiring boards. Background Technology

[0002] For various electronic devices, with the increasing amount of information processed, integration technologies such as high integration of semiconductor devices, high-density wiring, and multilayering are becoming increasingly advanced. Furthermore, wiring boards used in various electronic devices are seeking high-frequency solutions, such as millimeter-wave radar substrates for automotive applications. To improve signal transmission speed and reduce signal loss during transmission, the substrate material used to form the insulating layer of the wiring board in various electronic devices requires low relative permittivity and low dielectric loss factor. Examples of substrate materials used to form the insulating layer of such wiring boards include, for example, the resin compositions described in Patent Documents 1 and 2.

[0003] Patent Document 1 discloses a curable resin composition comprising a modified polyphenylene ether and a polyfunctional vinyl aromatic copolymer. The modified polyphenylene ether is obtained by modifying the terminal hydroxyl groups of the main chain with a (meth)acrylic acid compound. The polyfunctional vinyl aromatic copolymer contains repeating units derived from divinyl aromatic compounds and repeating units derived from monovinyl aromatic compounds. According to Patent Document 1, it discloses cured products or molded articles that provide improved heat resistance, compatibility, dielectric properties, damp heat reliability, and resistance to heat oxidation degradation.

[0004] Patent Document 2 discloses a resin composition containing a maleimide compound and a resin, wherein the maleimide compound has an isopropylidene group bonded to two aromatic carbon atoms of different aromatic rings, and the resin has a vinylphenyl and / or (meth)acryloyl group. According to prior art document 2, it discloses a cured product that can achieve even lower minimum melt viscosity, low dielectric loss factor, and excellent copper plating peel strength.

[0005] Metal-clad laminates and resin-coated metal foils used in the manufacture of wiring boards not only have an insulating layer, but also have metal foil on the insulating layer. Furthermore, wiring boards not only have an insulating layer, but also have wiring on the insulating layer. Examples of such wiring include the metal foil-formed wiring found in the metal-clad laminate and the resin-coated metal foil.

[0006] Electronic devices, especially small mobile devices such as mobile communication terminals and laptops, are rapidly developing towards diversification, high performance, thinness, and miniaturization. Along with this, the wiring boards used in these products also require increasingly finer conductor wiring, multilayered conductor wiring, thinner profiles, and higher performance in terms of mechanical properties. Therefore, the wiring boards must ensure that even with fine wiring, the wiring will not peel off from the insulating layer. To meet this requirement, the wiring boards must exhibit high adhesion between the wiring and the insulating layer. Therefore, for the metal-clad laminate, high adhesion between the metal foil and the insulating layer is required, and the substrate material used to form the insulating layer of the wiring board must be a cured product capable of achieving excellent adhesion to the metal foil.

[0007] When using a resin composition containing multiple components as a substrate material for forming the insulating layer of a wiring board, if the compatibility of the components in the cured product obtained by curing the resin composition is low, the components cannot be uniformly dispersed in the insulating layer obtained from the resin composition. Therefore, the effects of each component cannot be fully realized, potentially leading to reduced durability and other problems. Therefore, it is also required that the substrate material used to form the insulating layer of the wiring board yields a cured product with excellent compatibility to obtain a suitable insulating layer.

[0008] Existing technical documents

[0009] Patent documents

[0010] Patent Document 1: Japanese Patent Publication No. 2018-168347

[0011] Patent Document 2: International Patent Publication No. 2022 / 102756 Summary of the Invention

[0012] This invention was made in view of the aforementioned circumstances, and its object is to provide a resin composition capable of obtaining a cured product that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to metal foil. Furthermore, this invention aims to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal foil-coated laminate, and a wiring board obtained using the said resin composition.

[0013] Solution for solving the problem

[0014] One aspect of the present invention relates to a resin composition comprising: a pre-reaction product (A) obtained by pre-reacting a mixture comprising a polyfunctional vinyl aromatic copolymer (a1) and a maleimide compound (a2), wherein the polyfunctional vinyl aromatic copolymer (a1) contains repeating units derived from a divinyl aromatic compound, and the maleimide compound (a2) has an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms.

[0015] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description and accompanying drawings. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view illustrating an example of a prepreg according to an embodiment of the present invention.

[0017] Figure 2 This is a schematic cross-sectional view illustrating an example of a metal foil laminate according to an embodiment of the present invention.

[0018] Figure 3 This is a schematic cross-sectional view illustrating an example of a wiring board according to an embodiment of the present invention.

[0019] Figure 4 This is a schematic cross-sectional view illustrating an example of a resin-coated metal foil according to an embodiment of the present invention.

[0020] Figure 5 This is a schematic cross-sectional view illustrating an example of a resin-coated film according to an embodiment of the present invention. Detailed Implementation

[0021] The following describes the embodiments of the present invention, but the present invention is not limited to these embodiments.

[0022] The inventors have conducted various studies and found that the above-mentioned objectives can be achieved through the following invention.

[0023] [Resin Composition]

[0024] The resin composition according to embodiments of the present invention comprises: a pre-reaction product (A), obtained by pre-reacting a mixture comprising a polyfunctional vinyl aromatic copolymer (a1) and a maleimide compound (a2), wherein the polyfunctional vinyl aromatic copolymer (a1) contains repeating units derived from a divinyl aromatic compound, and the maleimide compound (a2) has an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms.

[0025] The inventors have conducted various studies to provide a resin composition that maintains excellent low dielectric properties and excellent adhesion to metal foils. Specifically, the inventors focused on the polyfunctional vinyl aromatic copolymer (a1) and found that the cured product obtained by curing it has excellent low dielectric properties and heat resistance. Furthermore, it was found that when the polyfunctional vinyl aromatic copolymer (a1) is cured using a maleimide compound, the glass transition temperature of the resulting cured product is increased compared to the case where a modified polyphenylene ether compound or other compounds other than maleimide compounds are used, as in the resin composition described in Patent Document 1, thereby improving heat resistance. On the other hand, according to the inventors' research, it was found that, depending on the type of maleimide compound used, the adhesion to the metal foil cannot always be sufficiently improved. Specifically, it was found that when the maleimide compound (a2) is used as the maleimide compound for use with the polyfunctional vinyl aromatic copolymer (a1), the adhesion to the metal foil can be improved compared to maleimide compounds that do not have an aliphatic backbone such as alkyl groups having 6 or more carbon atoms and alkylene groups having 6 or more carbon atoms (e.g., the resin composition described in Patent Document 2). The inventors believe this is because the maleimide compound (a2) having alkyl groups having 6 or more carbon atoms and alkylene groups having 6 or more carbon atoms improves flexibility compared to maleimide compounds that do not have an aliphatic backbone, such as the maleimide compound described in Patent Document 2. Therefore, it was found that by including the maleimide compound (a2) in the resin composition, a cured product with high adhesion to the metal foil can be obtained. Further research revealed that if only the maleimide compound (a2) is used as the maleimide compound in conjunction with the polyfunctional vinyl aromatic copolymer (a1), the compatibility of the resulting cured product is sometimes insufficient. To address this, the inventors discovered that by including a pre-reaction product (A) obtained by pre-reacting a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) in the resin composition, a cured product with high compatibility capable of suppressing phase separation between the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) can be obtained when the resin composition is cured. Furthermore, cured products obtained by curing the polyfunctional vinyl aromatic copolymer (a1) tend to become brittle. On the other hand, it was found that cured products obtained by curing the polyfunctional vinyl aromatic copolymer (a1) with the highly flexible maleimide compound (a2) obtained by pre-reacting the pre-reaction product (A) can improve adhesion to metal foils.

[0026] Based on the above reasons, the resin composition, through curing, can yield a cured product that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to metal foils. Furthermore, high compatibility also improves the dispersibility of the inorganic filler material contained in the resin composition. For this reason, when the resin composition contains inorganic filler material, a cured product with excellent dispersibility of the inorganic filler material can be obtained. In addition, wiring boards used in various electronic devices are required to be resistant to changes in the external environment. For example, excellent heat resistance is required so that the wiring board can be used even in high-temperature environments. Therefore, it is required that the substrate material used to form the insulating layer of the wiring board be a cured product with excellent heat resistance, such as a high glass transition temperature. Furthermore, in order to obtain a wiring board with excellent reliability over a wide temperature range, it is required that the substrate material used to form the insulating layer of the wiring board be a cured product with a high glass transition temperature. The resin composition is a resin composition that can yield a cured product that maintains excellent low dielectric properties, excellent heat resistance, compatibility, and adhesion to metal foils, and also exhibits excellent heat resistance. Furthermore, as mentioned above, multilayered wiring boards are required. When the insulating layer is formed in multiple layers, high interlayer adhesion is also required to prevent interlayer delamination. Therefore, the substrate material used to form the insulating layer of the wiring board is required to produce a cured product with excellent adhesion between adjacent cured products, i.e., excellent interlayer adhesion. The resin composition can produce a cured product that not only has excellent adhesion to the metal foil but also excellent interlayer adhesion. Therefore, the resin composition is a resin composition that can produce a cured product that maintains excellent low dielectric properties, as well as excellent heat resistance, compatibility, and adhesion to the metal foil, and also excellent interlayer adhesion and heat resistance.

[0027] (Pre-reaction product (A))

[0028] The pre-reaction product (A) is not particularly limited as long as it is a pre-reaction product obtained by reacting a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) in advance. The pre-reaction product (A) can be obtained, for example, by reacting the polyfunctional vinyl aromatic copolymer (a1) with the maleimide compound (a2) in advance. Alternatively, it can be obtained by reacting it with another raw material (a3), which is a compound capable of reacting with at least one of the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2). The resin composition is cured by curing the pre-reaction product (A). Furthermore, the mixture can be a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2), or it can be a mixture also containing the other raw material (a3). In the resin composition, the pre-reaction product (A) may, for example, contain a reaction product obtained by pre-reacting the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2), or it may contain a reaction product obtained by pre-reacting the polyfunctional vinyl aromatic copolymer (a1), the maleimide compound (a2), and the other raw materials (a3). Furthermore, in the resin composition, the pre-reaction product (A) may contain the reaction product obtained by pre-reacting the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2), or it may contain unreacted polyfunctional vinyl aromatic copolymer (a1), unreacted maleimide compound (a2), and unreacted other raw materials (a3).

[0029] (Multifunctional vinyl aromatic copolymer (a1))

[0030] The polyfunctional vinyl aromatic copolymer (a1) is not particularly limited as long as it contains repeating units (a1-1) derived from divinyl aromatic compounds. Examples of polyfunctional vinyl aromatic copolymers (a1) include those containing repeating units (a1-1) derived from divinyl aromatic compounds and repeating units (a1-2) derived from monovinyl aromatic compounds. More specifically, examples of the polyfunctional vinyl aromatic copolymer (a1) include: soluble polyfunctional vinyl aromatic copolymers, which are polyfunctional vinyl aromatic copolymers containing repeating units (a1-1) and repeating units (a1-2), wherein when the total of repeating units (a1-1) and repeating units (a1-2) is set to 100 mol%, the repeating unit (a1-1) contains 2 mol% or more and less than 95 mol%, the repeating unit (a1-2) contains 5 mol% or more and less than 98 mol%, and contains the following formula (a1-1). 1) The repeating unit (a1-1-1) with unsaturated groups shown is part of the repeating unit (a1-1) derived from the divinyl aromatic compound, and the mole fraction of the repeating unit (a1-1-1) in the sum of the repeating units (a1-1) and (a1-2) satisfies the following formula (2), and has a number-average molecular weight of 300 to 100,000, and a molecular weight distribution expressed as the ratio of weight-average molecular weight to number-average molecular weight of 100.0 or less, and is soluble in toluene, xylene, tetrahydrofuran, dichloroethane or chloroform, such a soluble polyfunctional vinyl aromatic copolymer. The soluble polyfunctional vinyl aromatic copolymer is also simply referred to as a copolymer.

[0031]

[0032] In formula (1), R1 represents an aromatic hydrocarbon group with 6 to 30 carbon atoms.

[0033] 0.02≤(a1-1-1) / [(a1-1)+(a1-2)]≤0.8 (2)

[0034] The soluble polyfunctional vinyl aromatic copolymer contains repeating units (a1-1) derived from the divinyl aromatic compound and repeating units (a1-2) derived from the monovinyl aromatic compound, and also contains repeating units (a1-1-1) shown in formula (1) as part of the repeating units (a1-1) derived from the divinyl aromatic compound.

[0035] When the total of the repeating unit (a1-1) and the repeating unit (a1-2) is 100 mol%, the soluble polyfunctional vinyl aromatic copolymer contains 2 mol% or more and less than 95 mol% of the repeating unit (a1-1), and contains 5 mol% or more and less than 98 mol% of the repeating unit (a1-2). Furthermore, when the total of the repeating unit (a1-1) and the repeating unit (a1-2) is 100 mol%, it contains 2 to 80 mol% of the repeating unit (a1-1-1).

[0036] The soluble multifunctional vinyl aromatic copolymer has a number-average molecular weight Mn of 300 to 100,000, a molecular weight distribution expressed as the ratio of weight-average molecular weight Mw to number-average molecular weight Mn (Mw / Mn) of less than 100.0, and is soluble in toluene, xylene, tetrahydrofuran, dichloroethane, or chloroform.

[0037] The soluble polyfunctional vinyl aromatic copolymer is not limited, and examples include copolymers containing repeating units (a1-2) derived from the monovinyl aromatic compound shown in formula (3) below and repeating units (a1-1) derived from the divinyl aromatic compound shown in formulas (4) and (5) below. These structural units may be arranged regularly or randomly.

[0038]

[0039]

[0040]

[0041] In formula (3), R2 represents an aromatic hydrocarbon group with 6 to 30 carbon atoms derived from the monovinyl aromatic compound. In formulas (4) and (5), R1 represents an aromatic hydrocarbon group with 6 to 30 carbon atoms derived from the divinyl aromatic compound. In formulas (3) to (5), h to k represent integers from 0 to 200, provided that their total is 2 to 20000.

[0042] Suitable soluble polyfunctional vinyl aromatic copolymers include, for example, copolymers in which R1 and R2 in formulas (3) to (5) are repeating units of aromatic hydrocarbon groups selected from the group consisting of phenyl groups that may have substituents, biphenyl groups that may have substituents, naphthyl groups that may have substituents, and terphenyl groups that may have substituents.

[0043] The soluble multifunctional vinyl aromatic copolymer is soluble in solvents. Furthermore, the repeating units mentioned in this specification are derived from monomers and include units that repeat in the main chain of the copolymer and units or terminal groups present in the terminal or side chains. Repeating units are also called structural units. In addition, the terminal groups mentioned in this specification include terminal groups derived from the monomers described above, as well as terminal groups derived from the chain transfer agents described later.

[0044] The structural unit (a1-1) derived from the divinyl aromatic compound contains more than 2 mol% and less than 95 mol% relative to the sum of the structural units (a1-2) derived from the monovinyl aromatic compound. The structural unit (a1-1) derived from the divinyl aromatic compound can be a structure in which only one of the two vinyl groups reacts, a structure in which two groups react, and so on. Among them, the repeating unit (a1-1-1) in which only one of the vinyl groups reacts, represented by formula (1), preferably contains 2 to 80 mol% relative to the sum, more preferably 5 to 70 mol%, further preferably 10 to 60%, and particularly preferably 15 to 50%. By containing 2 to 80 mol% of the repeating unit (a1-1-1) in which only one of the vinyl groups reacts, represented by formula (1), relative to the sum, it is possible to achieve a low dielectric loss factor, high toughness, excellent heat resistance, and excellent compatibility with other resins. Furthermore, after preparing the resin composition, the resistance to damp heat, resistance to heat oxidation degradation, and processability become excellent. When only one repeating unit (a1-1-1) reacts in the vinyl group shown in Formula (1) is less than 2 mol% relative to the total, there is a tendency for the heat resistance to decrease. Furthermore, when only one repeating unit (a1-1-1) reacts in the vinyl group shown in Formula (1) is more than 80 mol% relative to the total, there is a tendency for the interlayer peel strength to decrease after preparing the laminate.

[0045] Relative to the total, the soluble polyfunctional vinyl aromatic copolymer contains 5 mol% or more and less than 98 mol% of the structural units (a1-2) derived from the monovinyl aromatic compound, preferably 10 mol% or more and less than 90 mol%, more preferably 15 mol% or more and less than 85 mol%. If the structural units (a1-2) derived from the monovinyl aromatic compound are less than 5 mol% relative to the total, there is a tendency for insufficient processability. Furthermore, if the structural units (a1-2) derived from the monovinyl aromatic compound are more than 98 mol% relative to the total, there is a tendency for insufficient heat resistance of the cured product.

[0046] The vinyl groups present in formula (a1-1-1) function as crosslinking components, contributing to the heat resistance of the soluble multifunctional vinyl aromatic copolymer. On the other hand, it is believed that the structural units (a1-2) derived from monovinyl aromatic compounds are typically polymerized based on the 1,2-addition reaction of vinyl groups and therefore do not contain vinyl groups. That is, the structural units (a1-2) derived from monovinyl aromatic compounds do not function as crosslinking components but contribute to formability.

[0047] Styrene is preferably listed as a monovinyl aromatic compound. Furthermore, other monovinyl aromatic compounds besides styrene may also be used with styrene. In this case, assuming the total content of the styrene-derived structural unit (a1-2-1) and the structural unit (a1-2-2) of the monovinyl aromatic compound other than styrene is 100 mol%, the content of the styrene-derived structural unit (a1-2-1) is preferably 99 to 20 mol%, more preferably 98 to 30 mol%. If the content of the styrene-derived structural unit (a1-2-1) is within the above range, it combines heat resistance to oxidative degradation and formability, and is therefore preferred. When the styrene-derived structural unit (b1) is greater than 99 mol% relative to the total, there is a tendency for decreased heat resistance. Furthermore, when the structural unit (a1-2-2) of the monovinyl aromatic compound other than styrene is more than 80 mol% relative to the total [when the styrene-derived structural unit (a1-2-1) is less than 20 mol% relative to the total], there is a tendency for decreased formability.

[0048] The number-average molecular weight (Mn) of the soluble polyfunctional vinyl aromatic copolymer (converted from the number-average molecular weight Mn of standard polystyrene measured using GPC) is preferably 300 to 100,000, more preferably 400 to 50,000, and even more preferably 500 to 10,000. If the number-average molecular weight (Mn) of the soluble polyfunctional vinyl aromatic copolymer is less than 300, the amount of monofunctional copolymer components contained in the soluble polyfunctional vinyl aromatic copolymer increases, thus tending to decrease the heat resistance of the cured product. Furthermore, if the number-average molecular weight (Mn) of the soluble polyfunctional vinyl aromatic copolymer exceeds 100,000, it is prone to gel formation and viscosity increases, thus tending to decrease the processability.

[0049] The molecular weight distribution (Mw / Mn) of the soluble multifunctional vinyl aromatic copolymer, expressed as the ratio of weight-average molecular weight Mw (converted from standard polystyrene measured using GPC) to number-average molecular weight Mn, is preferably 100.0 or less, preferably 50.0 or less, more preferably 1.5 to 30.0, and even more preferably 2.0 to 20.0. If Mw / Mn exceeds 100.0, the processing characteristics of the soluble multifunctional vinyl aromatic copolymer tend to deteriorate, and there is a tendency for gelation to occur.

[0050] The soluble multifunctional vinyl aromatic copolymer is soluble in toluene, xylene, tetrahydrofuran, dichloroethane, or chloroform as solvents, preferably in any one of the aforementioned solvents. For it to be a solvent-soluble and multifunctional copolymer, a portion of the vinyl groups in the divinylbenzene must remain uncrosslinked, representing a suitable degree of crosslinking. Here, "soluble in solvents" means that, relative to 100g of the solvent, the soluble multifunctional vinyl aromatic copolymer dissolves in 5g or more, preferably 30g or more, and more preferably 50g or more.

[0051] The divinyl aromatic compound serves to form a branched structure for multifunctionalization, and also acts as a crosslinking component to enhance heat resistance during the thermosetting of the resulting soluble multifunctional vinyl aromatic copolymer.

[0052] The divinyl aromatic compound is not particularly limited to any aromatic compound having two vinyl groups, but is preferably used in the form of, for example, divinylbenzene (including isomers at various positions or mixtures thereof), divinylnaphthalene (including isomers at various positions or mixtures thereof), and divinylbiphenyl (including isomers at various positions or mixtures thereof). Furthermore, these can be used alone or in combination of two or more. From the viewpoint of processability, the divinyl aromatic compound is more preferably divinylbenzene (meta-isomer, para-isomer, or mixtures of isomers thereof).

[0053] Examples of the monovinyl aromatic compounds include styrene and other monovinyl aromatic compounds besides styrene. It is preferable that styrene is an essential component of the monovinyl aromatic compound, and that other monovinyl aromatic compounds besides styrene are also used simultaneously.

[0054] Styrene, as a monomer component, imparts low dielectric properties and resistance to heat and oxidation degradation to the soluble polyfunctional vinyl aromatic copolymer, and as a chain transfer agent, it controls the molecular weight of the soluble polyfunctional vinyl aromatic copolymer.

[0055] The monovinyl aromatic compounds other than styrene improve the solvent solubility and processability of the soluble polyfunctional vinyl aromatic copolymers.

[0056] As for the monovinyl aromatic compounds other than styrene, there is no particular limitation as long as it is an aromatic compound with one vinyl group other than styrene. Examples include vinyl naphthalene, vinyl biphenyl, and other vinyl aromatic compounds; and nucleoalkyl-substituted vinyl aromatic compounds such as o-methylstyrene, m-methylstyrene, p-methylstyrene, o-, p-dimethylstyrene, o-ethylvinylbenzene, m-ethylvinylbenzene, and p-ethylvinylbenzene. Since the monovinyl aromatic compounds other than styrene effectively prevent the gelation of the soluble multifunctional vinyl aromatic copolymers, improve solvent solubility and processability, are low in cost, and readily available, ethylvinylbenzene (including isomers at various positions or mixtures thereof), ethylvinyl biphenyl (including isomers at various positions or mixtures thereof), or ethylvinylnaphthalene (including isomers at various positions or mixtures thereof) are preferred. From the viewpoint of dielectric properties and cost, the monovinyl aromatic compounds other than styrene are preferably ethylvinylbenzene (meta-isomer, para-isomer, or mixtures of their positional isomers).

[0057] Without impairing the effects of the present invention, in addition to the divinyl aromatic compounds and the monovinyl aromatic compounds, one or more other monomeric components such as trivinyl aromatic compounds, trivinyl aliphatic compounds, divinyl aliphatic compounds and monovinyl aliphatic compounds may be used to introduce structural units (a1-3) derived from them into the soluble polyfunctional vinyl aromatic copolymer.

[0058] Other monomeric components mentioned above include, for example, 1,3,5-trivinylbenzene, 1,3,5-trivinylnaphthalene, 1,2,4-trivinylcyclohexane, ethylene glycol diacrylate, butadiene, 1,4-butanediol diethylene ether, cyclohexanediethanol diethylene ether, diethylene glycol diethylene ether, and triallyl isocyanurate. These can be used alone or in combination of two or more.

[0059] The molar fraction of the other monomeric components is preferably less than 30 mol% relative to the sum of all monomeric components. That is, the molar fraction of the repeating unit (a1-3) derived from the other monomeric components relative to the structural units [the sum of the structural units (a1-1), the structural units (a1-2), and the structural units (a1-3)] derived from all monomeric components constituting the soluble polyfunctional vinyl aromatic copolymer is preferably less than 30 mol%.

[0060] The soluble multifunctional vinyl aromatic copolymer is obtained by polymerizing monomers containing the divinyl aromatic compound and the monovinyl aromatic compound in the presence of a Lewis acid catalyst. Additionally, to control the molecular weight, a known chain transfer agent (CTR) can be added during polymerization.

[0061] (maleimide compound (a2))

[0062] The maleimide compound (a2) is not particularly limited as long as it is an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms. Preferably, the maleimide compound (a2) also has an alicyclic hydrocarbon group in its molecule. It should be noted that the maleimide compound (a2) not only has an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms, but also has a maleimide group in its molecule.

[0063] The weight-average molecular weight (Mw) of the maleimide compound (a2) is not particularly limited, but is preferably 500 to 4000, more preferably 500 to 1000. If the weight-average molecular weight (Mw) of the maleimide compound (a2) is within the above range, a resin composition with excellent reactivity with the multifunctional vinyl aromatic copolymer (a1) and superior low dielectric properties can be obtained. It should be noted that the weight-average molecular weight (Mw) here is simply a value obtained by conventional molecular weight determination methods, such as values ​​obtained using gel permeation chromatography (GPC).

[0064] Examples of the maleimide compound (a2) include, for example, maleimide compounds in which the alicyclic hydrocarbon group is bonded to an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms, and the alkylene group is bonded to the maleimide group. Examples of the maleimide compound (a2) include, for example, the maleimide compound shown in formula (6) below and the maleimide compound shown in formula (7) below. It should be noted that in the maleimide compound shown in formula (6) below and the maleimide compound shown in formula (7) below, the alkylene group is a group bonded to the maleimide group and the alicyclic hydrocarbon group, and the alkyl group is a group bonded to the alicyclic hydrocarbon group but not to the maleimide group.

[0065]

[0066] In formula (6), R1 represents an alkyl group with 6 or more carbon atoms. R2 represents an alkylene group with 6 or more carbon atoms. Cy1 represents an alicyclic hydrocarbon group. a represents the degree of substitution of R1. b represents the degree of substitution of the group represented by [ ] in formula (6).

[0067]

[0068] In formula (7), R3 and R4 each independently represent an alkyl group with 6 or more carbon atoms. R5 to R7 each independently represent an alkylene group with 6 or more carbon atoms. Cy2 and Cy3 each independently represent an alicyclic hydrocarbon group. c represents the degree of substitution of R3. d represents the degree of substitution of R4. n represents the number of repeating units.

[0069] a, b, c, and d each represent the degree of substitution. Specifically, as described above, a represents the degree of substitution of R1, preferably 0 to 4, more preferably 0 to 2, from the viewpoint of further improving adhesion to the metal foil. As described above, b represents the degree of substitution of the group represented by [ ] in formula (6), preferably 1 to 5, more preferably 1 to 3, from the viewpoint of further improving adhesion to the metal foil. As described above, c represents the degree of substitution of R3, preferably 0 to 4, more preferably 0 to 2, from the viewpoint of further improving adhesion to the metal foil. As described above, d represents the degree of substitution of R4, preferably 0 to 4, more preferably 0 to 2, from the viewpoint of further improving adhesion to the metal foil.

[0070] n represents the number of repeating units in formula (7) indicated by [ ], and examples include the number of repeating units in which the weight-average molecular weight Mw of the maleimide compound (a1) is within the above range. As n, from the viewpoint of further improving the adhesion to the metal foil, it is preferably 1 to 10, and more preferably 1 to 2.

[0071] The alkyl group is not particularly limited as long as it has 6 or more carbon atoms; it can be linear or branched, but linear is preferred. The alkyl group has 6 or more carbon atoms, preferably 6 to 20, and more preferably 6 to 12. If the number of carbon atoms is within the above range, the effects of the maleimide compound (a2) can be fully utilized (e.g., improved adhesion to metal foil). Examples of the alkyl group include hexyl, ethylhexyl, heptyl, methylheptyl, octyl, methyloctyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecanyl, octadecyl, nonadecanyl, and eicosyl. Hexyl and octyl are preferred as the alkyl group.

[0072] The alkylene group is not particularly limited as long as it has 6 or more carbon atoms; it can be linear or branched, but linear is preferred. The alkylene group has 6 or more carbon atoms, preferably 6 to 20, and more preferably 6 to 12. If the number of carbon atoms is within the above range, the effects of the maleimide compound (a2) can be fully utilized (e.g., improved adhesion to metal foil). Examples of alkylene groups include hexenyl, ethylhexenyl, heptenyl, methylheptenyl, octenyl, methyloctenyl, nonenyl, decenyl, undecenyl, dodecenyl, tridecenyl, tetradecenyl, pentadecenyl, hexadecenyl, heptadecenyl, heptadecenyl, octadecenyl, nonadecenyl, and eicosene. Octenyl is preferred.

[0073] The alicyclic hydrocarbon group is not particularly limited. For example, since the alkyl group having 6 or more carbon atoms is bonded to an alkylene group having 6 or more carbon atoms, divalent or higher alicyclic hydrocarbon groups can be listed. As the alicyclic hydrocarbon group, alicyclic hydrocarbon groups having 6 to 24 carbon atoms are preferred, and alicyclic hydrocarbon groups having 6 to 12 carbon atoms are more preferred. Furthermore, as the alicyclic hydrocarbon group, as described above, alicyclic hydrocarbon groups having 6 or more carbon atoms are preferred, and alicyclic hydrocarbon groups having 4 to 6 carbon atoms are more preferred. If the molecule [the maleimide compound (a2)] also contains this alicyclic hydrocarbon group, the effects of the maleimide compound (a2) can be fully utilized (e.g., effects such as improved adhesion to metal foil). Examples of alicyclic hydrocarbon groups include cycloalkyl groups (divalent or higher groups of cycloalkanes), and more specifically, cyclopropane, cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, cyclotridecane, cyclotetradecane, cyclopentadecanane, cyclohexadecane, cycloheptadecane, cyclooctadecane, cyclononadecanane, and cycloeicosane, etc.

[0074] The maleimide compound (a2) contains at least one maleimide group within its molecule. Each molecule of the maleimide compound (a2) has one or more maleimide groups, preferably 2 to 3.

[0075] Specific examples of the maleimide compound (a2) include, for example, the maleimide compound shown in formula (8) below and the maleimide compound shown in formula (9) below. It should be noted that, as the maleimide compound shown in formula (8) below, examples include BMI-689 manufactured by Designer Molecules Inc. Furthermore, as the maleimide compound shown in formula (9) below, examples include BMI-3000J manufactured by Designer Molecules Inc.

[0076]

[0077]

[0078] In equation (9), n represents 1 to 10.

[0079] (catalyst)

[0080] In the reaction between the multifunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2), a catalyst may also be used. The catalyst is not particularly limited as long as it helps to promote the reaction; examples include peroxides and azo compounds. Examples of peroxides include: α,α'-di(tert-butylperoxy)diisopropylbenzene (PBP), 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenol benzoquinone, chloroquinone, 2,4,6-tritert-butylphenoxy, and tert-butylperoxyisopropyl monocarbonate, etc. Examples of such azo compounds include azobisisobutyronitrile, 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile), etc.

[0081] (Reaction products)

[0082] In this embodiment, the resin composition includes, as the pre-reaction product (A), a reaction product obtained by reacting the polyfunctional vinyl aromatic copolymer (a1) with the maleimide compound (a2). Examples of such reaction products include those obtained by reacting the vinyl groups of the polyfunctional vinyl aromatic copolymer (a1) with the maleimide groups of the maleimide compound (a2). Examples of such reactions include, for instance, free radical copolymerization of the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2).

[0083] The mass ratio of the multifunctional vinyl aromatic copolymer (a1) to the maleimide compound (a2) is preferably 10:90 to 90:10, more preferably 70:30 to 90:10. Furthermore, the equivalent ratio of maleimide groups in the maleimide compound (a2) to vinyl groups in the multifunctional vinyl aromatic copolymer (a1) (maleimide groups in the maleimide compound (a2) / vinyl groups in the multifunctional vinyl aromatic copolymer (a1)) is preferably 1 to 7, more preferably 1 to 3. If there is too much of the multifunctional vinyl aromatic copolymer (a1), i.e., too little of the maleimide compound (a2), there is a tendency for reduced adhesion to the metal foil. Furthermore, if there is too little of the multifunctional vinyl aromatic copolymer (a1), i.e., too much of the maleimide compound (a2), there is a tendency for reduced heat resistance, such as a decrease in the glass transition temperature. Furthermore, an excessive amount of either the polyfunctional vinyl aromatic copolymer (a1) or the maleimide compound (a2) tends to reduce compatibility. This is believed to be because the reaction between the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) is difficult to occur. Therefore, if the mass ratio is within the above range, a resin composition with improved low dielectric properties, heat resistance, compatibility, and adhesion to metal foils can be obtained.

[0084] The weight-average molecular weight Mw of the reaction product is the weight-average molecular weight Mw of the reaction product obtained by reacting the polyfunctional vinyl aromatic copolymer (a1) with the maleimide compound (a2), preferably 25,000 to 95,000, more preferably 30,000 to 50,000. It should be noted that the weight-average molecular weight Mw here is simply a value obtained by conventional molecular weight determination methods, such as values ​​obtained using gel permeation chromatography (GPC).

[0085] The reaction conditions are not particularly limited as long as the reaction proceeds. For example, a reaction rate of 30% or higher, i.e., 30% to 100%, is preferred. It should be noted that the reaction conditions can also be adjusted by sampling the reaction products over time and confirming the reaction rate during the pre-reaction process.

[0086] Examples of reaction rates include, for instance, the rate of change of a compound, where the rate of change is the change in molecular weight of the compound (reaction product) after the reaction, obtained by removing the molecular weight of the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound before the reaction. Specifically, a reaction rate expressed as the reaction rate over time t from the start of the reaction can be exemplified by the following formula. That is, a reaction rate over time t from the start of the reaction can be exemplified by the ratio of area S(0) to the difference between area S(t) and area S(0), where area S(t) is the area of ​​the GPC corresponding to the amount of a compound with a molecular weight of 600 to 1450 at time t from the start of the reaction, and area S(0) is the area of ​​the GPC corresponding to the amount of a compound with a molecular weight of 600 to 1450 before the start of the reaction.

[0087] Reaction rate (%) = [(S(0) - S(t)) / (S(0) × 100)]

[0088] As described above, the reaction conditions can be categorized as a reaction rate of 30% or higher. More specifically, the reaction temperature is preferably 80–110°C, more preferably 90–100°C. If the reaction temperature is too low, the reaction tends to be difficult to proceed. Furthermore, if the reaction temperature is too high, polymerization between the pre-reaction products is likely to occur, and the reaction between the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) tends to be difficult to proceed well. Therefore, if the reaction temperature is within the specified range, the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) can react well. Furthermore, the reaction time is preferably 180–900 minutes, more preferably 360–600 minutes. If the reaction time is too short, the reaction tends to be difficult to proceed. If the reaction time is too long, gelation may occur. Therefore, if the reaction time is within the specified range, the reaction between the multifunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) can proceed effectively.

[0089] (Reactive compound (B))

[0090] The resin composition of this embodiment may also contain a reactive compound (B), preferably the reactive compound (B). The reactive compound (B) is not particularly limited to any compound that reacts with the pre-reaction product (A). Examples of the reactive compound (B) include allyl compounds, methacrylate compounds, acrylate compounds, acenaphthene compounds, vinyl compounds, isocyanurate compounds, polyphenylene ether compounds having carbon-carbon unsaturated double bonds in the molecule, and maleimide compounds other than the maleimide compound (a1).

[0091] The allyl compound is a compound having an allyl group within its molecule. Examples of such allyl compounds include diallyl bisphenol compounds and diallyl phthalate (DAP).

[0092] The methacrylate compound is a compound having a methacryl group within its molecule. Examples of such methacrylate compounds include monofunctional methacrylate compounds having one methacryl group within their molecule, and polyfunctional methacrylate compounds having two or more methacryl groups within their molecule. Examples of monofunctional methacrylate compounds include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Examples of polyfunctional methacrylate compounds include dimethacrylate compounds such as tricyclodecanediethanol dimethacrylate (DCP).

[0093] The acrylate compound is a compound having an acryloyl group within its molecule. Examples of such acrylate compounds include monofunctional acrylate compounds having one acryloyl group within their molecule, and polyfunctional acrylate compounds having two or more acryloyl groups within their molecule. Examples of monofunctional acrylate compounds include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. Examples of polyfunctional acrylate compounds include diacrylate compounds such as tricyclodecanediethanol diacrylate.

[0094] The acenaphthene compound is a compound having an acenaphthene structure within its molecule. Examples of such acenaphthene compounds include: acenaphthene, alkylacenaphthenes, haloacenaphthenes, and phenylacenaphthenes. Examples of such alkylacenaphthenes include: 1-methylacenaphthene, 3-methylacenaphthene, 4-methylacenaphthene, 5-methylacenaphthene, 1-ethylacenaphthene, 3-ethylacenaphthene, 4-ethylacenaphthene, 5-ethylacenaphthene, etc. Examples of such haloacenaphthenes include: 1-chloroacenaphthene, 3-chloroacenaphthene, 4-chloroacenaphthene, 5-chloroacenaphthene, 1-bromoacenaphthene, 3-bromoacenaphthene, 4-bromoacenaphthene, 5-bromoacenaphthene, etc. Examples of phenylacenaphthenes include 1-phenylacenaphthene, 3-phenylacenaphthene, 4-phenylacenaphthene, and 5-phenylacenaphthene. The acenaphthene compound can be a monofunctional acenaphthene compound having one acenaphthene structure within the molecule, as described above, or a polyfunctional acenaphthene compound having two or more acenaphthene structures within the molecule.

[0095] The vinyl compound is a compound having a vinyl group within its molecule. Examples of such vinyl compounds include monofunctional vinyl compounds having one vinyl group within their molecule, and polyfunctional vinyl compounds having two or more vinyl groups within their molecule. Examples of monofunctional vinyl compounds include vinylbenzene compounds containing a phosphorus backbone, such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Examples of polyfunctional vinyl compounds include divinylbenzene and polybutadiene compounds. Examples of polybutadiene compounds include polybutadiene and hydrogenated styrene-butadiene copolymers; more specifically, examples include B-1000, B-2000, and B-3000 manufactured by Nippon Soda Corporation, and Ricon manufactured by Cray Valley Corporation.

[0096] The isocyanurate compound is a compound having an isocyanurate structure within its molecule. Examples of such isocyanurate compounds include triallyl isocyanurate compounds such as triallyl isocyanurate (TAIC).

[0097] The polyphenylene ether compound is not particularly limited to any polyphenylene ether compound having a carbon-carbon unsaturated double bond within its molecule. Examples of such polyphenylene ether compounds include, for example, polyphenylene ether compounds having a carbon-carbon unsaturated double bond at the terminal end; more specifically, examples include modified polyphenylene ether compounds whose terminals are modified by substituents having a carbon-carbon unsaturated double bond, and polyphenylene ether compounds containing substituents having a carbon-carbon unsaturated double bond at the molecule's terminal end. Examples of substituents having a carbon-carbon unsaturated double bond include, for example, vinylbenzyl (vinylbenzyl), acryloyl, and methacryl.

[0098] The maleimide compound is not particularly limited as long as it is a maleimide compound other than maleimide compound (a1). Examples of such maleimide compounds include: monofunctional maleimide compounds having one maleimide group in the molecule, and polyfunctional maleimide compounds having two or more maleimide groups in the molecule. Examples of such modified maleimide compounds include: modified maleimide compounds in which a portion of the molecule is modified by an amine, modified maleimide compounds in which a portion of the molecule is modified by an organosilicon, and modified maleimide compounds in which a portion of the molecule is modified by both an amine and an organosilicon.

[0099] The curing agent is preferably, for example, the acenaphthene compound and the polyphenylene ether compound mentioned above, and more preferably, a polyphenylene ether compound having acenaphthene and methacryl groups at the molecular ends. Regarding the curing agent, the above-mentioned curing agents can be used alone, or two or more can be used in combination. As the curing agent, it is preferable to use both the acenaphthene compound and the polyphenylene ether compound simultaneously, and more preferably, to use both acenaphthene and a polyphenylene ether compound having methacryl groups at the molecular ends.

[0100] (content)

[0101] The content of the pre-reaction product (A) is preferably 30% by mass or more, more preferably 60% by mass or more, relative to the total mass of the pre-reaction product (A) and the curing agent (B). Furthermore, the resin composition may or may not contain the curing agent (B), provided that the pre-reaction product (A) is included. Therefore, the content of the pre-reaction product (A) is preferably 100% by mass, preferably 90% by mass or less, relative to the total mass of the pre-reaction product (A) and the curing agent (B). Therefore, the content of the pre-reaction product (A) is preferably 30 to 100% by mass, more preferably 60 to 90% by mass, relative to the total mass of the pre-reaction product (A) and the curing agent (B).

[0102] (Inorganic filler material)

[0103] The resin composition according to this embodiment may contain inorganic filler materials as needed, without impairing the effects of the present invention. Furthermore, from the viewpoint of improving the heat resistance of the cured resin composition, it is preferable to include the inorganic filler material. The inorganic filler material is not particularly limited as long as it can be used as an inorganic filler material in the resin composition. Examples of such inorganic filler materials include: metal oxide fillers (silica fillers, alumina fillers, titanium oxide fillers, magnesium oxide fillers, and mica fillers, etc.), metal hydroxide fillers (magnesium hydroxide fillers and aluminum hydroxide fillers, etc.), talc fillers, aluminum borate fillers, barium sulfate fillers, aluminum nitride fillers, boron nitride fillers, barium titanate fillers, strontium titanate fillers, calcium titanate fillers, aluminum titanate fillers, magnesium carbonate fillers (anhydrous magnesium carbonate fillers, etc.), calcium carbonate fillers, molybdate compound fillers (zinc molybdate fillers, calcium molybdate fillers, etc.), and talc fillers supporting the molybdate compound. Among these, silica fillers, metal hydroxide fillers (such as magnesium hydroxide fillers and aluminum hydroxide fillers), alumina fillers, boron nitride fillers, strontium titanate fillers, calcium titanate fillers, and zinc molybdate fillers are preferred, with silica fillers being more preferred. The silica filler is not particularly limited, and examples include pulverized silica, spherical silica, and silica particles, with spherical silica being preferred. As the inorganic filler material, each of the examples can be used alone, or two or more can be used in combination. When two or more of the inorganic filler materials are used in combination, silica fillers can be combined with one or more inorganic fillers other than silica fillers, with silica fillers being preferably combined with zinc molybdate fillers.

[0104] The inorganic filler material can be a surface-treated inorganic filler material or an untreated inorganic filler material. Furthermore, examples of surface treatment include treatment with a silane coupling agent.

[0105] The silane coupling agent is not particularly limited, and examples include silane coupling agents having at least one functional group selected from the group consisting of vinyl, styrene, methacryloyl, acryloyl, phenylamino, isocyanurate, urea, mercapto, isocyanate, epoxy, and anhydride groups. Specifically, examples of such silane coupling agents include compounds having at least one reactive functional group selected from vinyl, styrene, methacryloyl, acryloyl, phenylamino, isocyanurate, urea, mercapto, isocyanate, epoxy, and anhydride groups, and having hydrolyzable groups such as methoxy or ethoxy.

[0106] Regarding the silane coupling agent, examples of vinyl-containing silane coupling agents include vinyltriethoxysilane and vinyltrimethoxysilane. Examples of styrene-containing silane coupling agents include p-styrenetrimethoxysilane and p-styrenetriethoxysilane. Examples of methacryloxysilane coupling agents include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-methacryloyloxypropylethyldiethoxysilane. Examples of acryloyloxypropyltrimethoxysilane include 3-acryloyloxypropyltrimethoxysilane and 3-acryloyloxypropyltriethoxysilane. Regarding the silane coupling agent, examples of silane coupling agents containing phenylamino groups include N-phenyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltriethoxysilane.

[0107] The average particle size of the inorganic filler material is not particularly limited, but is preferably 0.05–10 μm, more preferably 0.1–8 μm. It should be noted that the average particle size here refers to the volume average particle size. The volume average particle size can be determined by, for example, laser diffraction.

[0108] When the inorganic filler material is present, its content is preferably 40 to 120 parts by mass relative to 100 parts by mass of the total mass of the pre-reaction product (A) and the curing agent (B), and more preferably 50 to 100 parts by mass.

[0109] (Flame retardant)

[0110] The resin composition involved in this embodiment may contain a flame retardant as needed, without impairing the effects of the present invention. From the viewpoint that containing a flame retardant can improve the flame retardancy of the cured resin composition, it is preferable to contain such a flame retardant. The flame retardant is not particularly limited. As the flame retardant, in the field of using halogenated flame retardants such as bromine-based flame retardants, substances with a melting point of 300°C or higher are preferred, such as ethylenedipentabromobenzene, ethylenebistetrabromoimide, decabromodiphenyl ether, tetradecylbromodiphenoxybenzene, and bromostyrene compounds that react with the polymerizable compound. It is believed that by using a halogenated flame retardant, halogen release at high temperatures can be suppressed, and the decrease in heat resistance can be prevented. Furthermore, in fields requiring halogen-free flame retardants, phosphorus-containing flame retardants (phosphorus-based flame retardants) are preferred. As for the phosphorus-based flame retardant, there are no particular limitations as long as it contains phosphorus and can exert flame retardant properties. Examples include compatible phosphorus-based flame retardants that are compatible with the mixture of the pre-reaction product (A) and the curing agent (B), and incompatible phosphorus-based flame retardants that are incompatible with the mixture.

[0111] The compatible phosphorus-based flame retardant is not particularly limited to any phosphorus-based flame retardant that is compatible with the mixture. Furthermore, in this case, compatibility refers to, for example, a state of micro-dispersion at the molecular level in the mixture. Examples of compatible phosphorus-based flame retardants include: phosphate ester-based flame retardants, phosphazene-based flame retardants, phosphite-based flame retardants, and hypophosphite-based flame retardants. Examples of phosphate ester-based flame retardants include, for example, triphenyl phosphate, tricresyl phosphate, dimethyldiphenyl phosphate, toluenediphenyl phosphate, 1,3-phenylenebis(di-2,6-dimethylphosphite), 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) flame retardants, aromatic polyphosphate compounds, and cyclic phosphate compounds. Specific examples of DOPO-based flame retardants include hydrocarbons (DOPO-derived compounds) having two DOPO groups within the molecule, and DOPO with reactive functional groups. Furthermore, examples of phosphazene-based flame retardants include cyclic or chain-like phosphazene compounds, specifically xylenebis(diphenylphosphine). It should be noted that cyclic phosphazene compounds, also called cyclophosphonitriles, are compounds with a cyclic structure containing double bonds of phosphorus and nitrogen as constituent elements within the molecule. Furthermore, examples of phosphite-based flame retardants include trimethyl phosphite and triethyl phosphite. Furthermore, examples of hypophosphite-based flame retardants include tris-(4-methoxyphenyl)phosphine and triphenylphosphine. Moreover, the compatible phosphorus-based flame retardants can be used alone or in combination of two or more.

[0112] The incompatible phosphorus-based flame retardant is not particularly limited to any phosphorus-based flame retardant that is compatible with the mixture. Furthermore, in this case, compatibility means incompatibility in the mixture, where the target substance (phosphorus-based flame retardant) is dispersed in an island-like state within the mixture. Examples of incompatible phosphorus-based flame retardants include hypophosphite-based flame retardants, polyphosphate-based flame retardants, phosphonium salt-based flame retardants, and phosphine oxy-based flame retardants. Examples of hypophosphite-based flame retardants include dialkyl aluminum hypophosphite, tris(diethyl) aluminum hypophosphite, trimethylethyl aluminum hypophosphite, tris(diphenyl) aluminum hypophosphite, bis(diethyl) zinc hypophosphite, bis(dimethyl) zinc hypophosphite, bis(diphenyl) zinc hypophosphite, bis(diethyl) titanium hypophosphite, bis(dimethyl) titanium hypophosphite, and bis(diphenyl) titanium hypophosphite. Examples of polyphosphate-based flame retardants include melamine polyphosphate, melamine polyphosphate, and melamine polyphosphate. Furthermore, examples of phosphonium salt-based flame retardants include tetraphenylphosphonium tetraphenylborate and tetraphenylphosphonium bromide. Examples of phosphine oxygen-based flame retardants include phosphine oxygen compounds (diphenylphosphine oxygen compounds) having two or more diphenylphosphine oxy groups within their molecules. Additionally, the incompatible phosphorus-based flame retardants can be used alone or in combination of two or more.

[0113] The flame retardant can be used alone or in combination of two or more. Furthermore, it is preferable to use both the compatible phosphorus-based flame retardant and the incompatible phosphorus-based flame retardant simultaneously, and more preferably, to use both an aromatic polyphosphate compound and a diphenylphosphine oxide compound simultaneously.

[0114] When the flame retardant is present, its content is preferably 10 to 60 parts by mass relative to 100 parts by mass of the total mass of the pre-reaction product (A) and the curing agent (B), and more preferably 20 to 50 parts by mass.

[0115] (Reaction initiator)

[0116] The resin composition described in this embodiment may contain a reaction initiator as needed, without impairing the effects of the present invention. The resin composition can undergo a curing reaction even without a reaction initiator. On the other hand, depending on the process conditions, it may be difficult to raise the temperature until curing occurs, so a reaction initiator may be added. The reaction initiator is not particularly limited as long as it can promote the curing reaction of the resin composition. Examples of reaction initiators include peroxides and azo compounds. Examples of peroxides include: α,α'-di(tert-butylperoxy)diisopropylbenzene (PBP), 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenol benzoquinone, chloroquinone, 2,4,6-tritert-butylphenoxy, and tert-butylperoxyisopropyl monocarbonate, etc. Examples of azo compounds include azobisisobutyronitrile, 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile), among other organic azo compounds. Furthermore, the reaction initiator can be used alone or in combination of two or more. It is preferable to use both the peroxide and the azo compound simultaneously as the reaction initiator. Additionally, a metal salt of carboxylic acid may be used simultaneously as needed. This further promotes the curing reaction. Preferably, α,α'-di(tert-butylperoxy)diisopropylbenzene and 2,2'-azobis(2,4,4-trimethylpentane) are used as the reaction initiator. Because α,α'-di(tert-butylperoxy)diisopropylbenzene has a relatively high reaction initiation temperature, it can suppress the promotion of the curing reaction during prepreg drying and other times when curing is not required, thus preventing a decrease in the shelf life of the resin composition. It should be noted that α,α'-bis(tert-butylperoxy)diisopropylbenzene has low volatility and therefore does not volatilize during the drying of prepreg and during storage, exhibiting good stability.

[0117] When the reaction initiator is present, its content is preferably 0.1 to 2 parts by mass relative to 100 parts by mass of the total mass of the pre-reaction product (A) and the curing agent (B), more preferably 0.5 to 1.5 parts by mass.

[0118] (Free radical compounds)

[0119] The resin composition according to this embodiment may contain a free radical compound as needed, without impairing the effects of the present invention. The free radical compound is a compound having a free radical group within its molecule, and is different from the polyfunctional vinyl aromatic copolymer (a1), the maleimide compound (a2), and the curing agent (B). By utilizing the free radical groups present within its molecule to capture free radicals and delay the free radical reaction, the free radical compound can slow down the curing reaction of the resin composition. Examples of such free radical compounds include free radical compounds having a 2,2,6,6-tetramethylpiperidin-1-oxy (TEMPO) structure within their molecule.Specific examples of the free radical compounds include, for example, 4-amino-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-acetamido-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-amino-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-carboxyl-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-cyano-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-glycidoxy-2,2,6,6-tetramethylpiperidine 1-oxy radical, and 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxy radical. ,6-Tetramethylpiperidine 1-oxy radical, 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxybenzoate radical, 4-isothiocyanate-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-(2-iodoacetamido)-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-[2-[2-(4-iodophenoxy)ethoxy]carbonyl]benzoyloxy-2,2,6,6-tetramethylpiperidine-1-oxy radical, 4-methoxy-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-methacryloyl 2,2,6,6-Tetramethylpiperidine 1-oxy radical, 4-oxo-2,2,6,6-tetramethylpiperidine 1-oxy radical, 4-oxo-2,2,6,6-tetraethylpiperidine 1-oxy radical, 2,2,6,6-tetramethylpiperidine 1-oxy radical, 2,2,6,6-tetramethyl-4-(2-propynyloxy)piperidine 1-oxy radical, 2,2,6,6-tetramethylpiperidine 1-oxy radical, 4,5-dihydroxy-4,4,5,5-tetramethyl-2-phenyl-1H-imidazol-1-yloxy-1-oxide Free radicals, including sebacic acid bis(2,2,6,6-tetramethyl-4-piperidinyl-1-oxy) radical, 3-carboxy-2,2,5,5-tetramethylpyrrolidine-1-oxy radical, 4-(2-chloroacetamido)-2,2,6,6-tetramethylpiperidinyl-1-oxy radical, 2-(4-nitrophenyl)-4,4,5,5-tetramethylimidazoline-3-oxide-1-oxy radical, 2-(14-carboxytetradecyl)-2-ethyl-4,4-dimethyl-3-oxazolidineoxy radical, and 1,1-diphenyl-2-picrylhydrazine radical, etc. Among these, 4-hydroxy-2,2,6,6-tetramethylpiperidinyl-1-oxy radical is preferred as the free radical compound. Furthermore, the free radical compounds can be used alone or in combination of two or more. Commercially available products can be used as the free radical compound, and examples of commercially available free radical compounds include LA-7RD manufactured by Adico Corporation.

[0120] When the free radical compound is present, its content is preferably 0.001 to 0.1 parts by mass relative to 100 parts by mass of the total mass of the pre-reaction product (A) and the curing agent (B), and more preferably 0.001 to 0.05 parts by mass.

[0121] (Silane coupling agent)

[0122] The resin composition involved in this embodiment may contain a silane coupling agent as needed, without impairing the effects of the present invention. The silane coupling agent may be included in the resin composition or may be included as a silane coupling agent for which the inorganic filler material contained in the resin composition has been pre-treated. Preferably, the silane coupling agent is included as a silane coupling agent for which the inorganic filler material has been pre-treated; more preferably, it is included as a silane coupling agent for which the inorganic filler material has been pre-treated, and the resin composition also contains the silane coupling agent. Furthermore, in the case of prepregs, the silane coupling agent may be included as a silane coupling agent for which the fibrous substrate has been pre-treated. Examples of such silane coupling agents include, for instance, the same silane coupling agent used when surface-treating the inorganic filler material as described above.

[0123] When the silane coupling agent is present, its content is preferably 0.1 to 2 parts by mass relative to 100 parts by mass of the total mass of the pre-reaction product (A) and the curing agent (B), more preferably 0.3 to 1.2 parts by mass.

[0124] (Other ingredients)

[0125] The resin composition described in this embodiment may contain components other than the pre-reaction product (A) and the curing agent (B) (other components) without impairing the effects of the present invention. The resin composition may also contain the flame retardant, the reaction initiator, the free radical compound, the silane coupling agent, and the inorganic filler as the other components, as described above. Examples of these other components, besides the inorganic filler, include, for example, organic components other than the pre-reaction product (A) and the curing agent (B), curing accelerators, catalysts, polymerization retarders, polymerization inhibitors, dispersants, homogenizers, defoamers, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes or pigments, and additives such as lubricants.

[0126] As described above, the resin composition according to this embodiment may contain organic components other than the pre-reaction product (A) and the curing agent (B). These organic components may be, for example, compounds that react with one of the pre-reaction product (A) and the curing agent (B), or compounds that do not react. Specifically, examples of these organic components include oxazine compounds, epoxy compounds, cyanate ester compounds, and reactive ester compounds.

[0127] The term "oxazine compound" is not particularly limited to any compound containing an oxazine group within its molecule. Examples of such oxazine compounds include, for instance, benzoxazine compounds containing a phenolphthalein structure within their molecule (phenolphthalein-type benzoxazine compounds), bisphenol F-type benzoxazine compounds, and diaminodiphenylmethane (DDM)-type benzoxazine compounds. More specifically, examples of such oxazine compounds include 3,3'-(methylene-1,4-diphenylene)bis(3,4-dihydro-2H-1,3-benzoxazine) (Pd-type benzoxazine compounds) and 2,2-bis(3,4-dihydro-2H-3-phenyl-1,3-benzoxazine)methane (Fa-type benzoxazine compounds).

[0128] The epoxy compound is a compound having an epoxy group within its molecule. Specifically, examples include: bisphenol-type epoxy compounds such as bisphenol A type epoxy compounds, phenolic aldehyde type epoxy compounds, cresol aldehyde type epoxy compounds, dicyclopentadiene type epoxy compounds, bisphenol A aldehyde type epoxy compounds, biphenyl aryl alkyl type epoxy compounds, polybutadiene compounds having an epoxy group within their molecule, and epoxy compounds containing a naphthalene ring. Furthermore, the epoxy compound also includes epoxy resins that are polymers of each of the aforementioned epoxy compounds.

[0129] The cyanate ester compound is a compound having a cyanato group in the molecule, and examples include 2,2-bis(4-cyanooxyphenyl)propane, bis(3,5-dimethyl-4-cyanooxyphenyl)methane, and 2,2-bis(4-cyanooxyphenyl)ethane.

[0130] The active ester compound is a compound with a highly reactive ester group within the molecule, and examples include: benzenecarboxylic acid active ester, benzenedicarboxylic acid active ester, benzenetricarboxylicacid active ester, benzenetetracarboxylic acid active ester, naphthalenecarboxylic acid active ester, naphthalenedicarboxylic acid active ester, naphthalenetricarboxylic acid active ester, naphthalenetetracarboxylic acid active ester, fluorenecarboxylic acid active ester, fluorenedicarboxylicacid active ester, fluorenetricarboxylic acid active ester, and fluorenetetracarboxylic acid active ester. ester), etc.

[0131] As described above, the resin composition according to this embodiment may contain a curing accelerator. The curing accelerator is not particularly limited as long as it can promote the curing reaction of the resin composition. Specifically, examples of curing accelerators include: imidazoles and their derivatives, organophosphorus compounds, amines such as secondary and tertiary amines, quaternary ammonium salts, organoboron compounds, and metal soaps. Examples of imidazoles include: 2-ethyl-4-methylimidazolium (2E4MZ), 2-methylimidazolium, 2-phenyl-4-methylimidazolium, 2-phenylimidazolium, and 1-benzyl-2-methylimidazolium. Examples of organophosphorus compounds include: triphenylphosphine, diphenylphosphine, phenylphosphine, tributylphosphine, and trimethylphosphine. Examples of amines include: dimethylbenzylamine, triethylenediamine, triethanolamine, and 1,8-diazabicyclo(5,4,0)undecene-7 (DBU). Examples of quaternary ammonium salts include tetrabutylammonium bromide. Furthermore, examples of the organoboron compounds include tetraphenylboron salts such as 2-ethyl-4-methylimidazole tetraphenylborate, and tetra-substituted phosphonium tetra-substituted borates such as tetraphenylphosphonium ethyltriphenylborate. Additionally, the metal soap refers to a fatty acid metal salt, which can be a linear or cyclic fatty acid metal salt. Specifically, examples of the metal soap include linear aliphatic metal salts with 6 to 10 carbon atoms and cyclic aliphatic metal salts. More specifically, examples include aliphatic metal salts formed from linear fatty acids such as stearic acid, lauric acid, ricinoleic acid, and octanoic acid, or cyclic fatty acids such as naphthenic acids, and metals such as lithium, magnesium, calcium, barium, copper, and zinc. For example, zinc octanoate can be cited. The curing accelerator can be used alone or in combination of two or more.

[0132] The resin composition involved in this embodiment is a resin composition that can produce a cured product that maintains excellent low dielectric properties, and has excellent compatibility and adhesion to metal foil. Furthermore, the resin composition is a resin composition that can produce a cured product that maintains excellent low dielectric properties, and has excellent heat resistance, compatibility, and adhesion to metal foil, as well as excellent interlayer adhesion and heat resistance.

[0133] (use)

[0134] The resin composition involved in this embodiment is used in the manufacture of prepregs as described below. Furthermore, the resin composition is used in the formation of resin layers disposed on resin-coated metal foils and resin-coated films, and insulating layers disposed on metal foil laminates and wiring boards.

[0135] (Manufacturing method)

[0136] The method for manufacturing the resin composition according to this embodiment is not particularly limited, and examples include: mixing the pre-reaction product (A) with the curing agent (B) and other components added as needed under conditions that achieve a specified content. Furthermore, in the case of obtaining a varnish-like composition containing organic solvents, methods described later can be used.

[0137] By using the resin composition involved in this embodiment, prepreg, metal foil laminate, wiring board, resin-coated metal foil, and resin-coated film can be obtained as described below.

[0138] [Prepreg]

[0139] Figure 1 This is a schematic cross-sectional view illustrating an example of the prepreg 1 according to an embodiment of the present invention.

[0140] like Figure 1 As shown, the prepreg 1 according to this embodiment includes: the resin composition or the semi-cured product of the resin composition 2; and a fibrous substrate 3. The prepreg 1 includes: the resin composition or the semi-cured product of the resin composition 2; and a fibrous substrate 3 present in the resin composition or the semi-cured product of the resin composition 2.

[0141] It should be noted that, in this embodiment, a semi-cured product is a substance that has been cured to a point where it can still be further cured. That is, a semi-cured product is a substance in a semi-cured state (benzened). For example, if the resin composition is heated, the viscosity initially decreases slowly, then begins to cure, and the viscosity slowly increases. In this case, the state from the start of the viscosity increase until complete curing can be listed as a semi-cured product.

[0142] As a prepreg obtained using the resin composition according to this embodiment, it can be a prepreg containing a semi-cured product of the resin composition, as described above. Alternatively, it can be a prepreg containing an uncured resin composition. That is, it can be a prepreg containing a semi-cured product of the resin composition (the resin composition of stage B) and a fibrous substrate, or it can be a prepreg containing the resin composition before curing (the resin composition of stage A) and a fibrous substrate. Furthermore, the resin composition or the semi-cured product of the resin composition can be a substance obtained by drying or heating the resin composition.

[0143] In manufacturing the prepreg, the resin composition 2 is mostly formulated into a varnish-like form for impregnation into the fibrous substrate 3 used to form the prepreg. That is, the resin composition 2 is typically a resin varnish formulated into a varnish-like form. This varnish-like resin composition (resin varnish) can be formulated, for example, in the following manner.

[0144] First, the components soluble in the organic solvent are added to the organic solvent and dissolved. Heating may be performed at this time if necessary. Then, the components insoluble in the organic solvent are added as needed, and the mixture is dispersed to a specified dispersion state using a ball mill, bead mill, planetary mixer, roller mill, etc., thereby preparing a varnish-like resin composition. The organic solvent used herein is not particularly limited, as long as it can dissolve the organic components, resin components, etc., in the resin composition and does not hinder the curing reaction. Examples of suitable organic solvents include toluene and methyl ethyl ketone (MEK).

[0145] Specifically, examples of the fibrous substrate include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and cotton linter paper. It should be noted that using glass cloth results in a laminate with excellent mechanical strength, and glass cloth that has undergone a flattening process is particularly preferred. Specifically, the flattening process can be exemplified by continuously applying appropriate pressure to the glass cloth using pressure rollers to compress the yarn into a flat shape. It should be noted that the thickness of the fibrous substrate is typically between 0.01 mm and 0.3 mm. Furthermore, the glass fibers constituting the glass cloth are not particularly limited, and examples include Q glass, NE glass, E glass, S glass, T glass, L glass, and L2 glass. Additionally, the surface of the fibrous substrate can be surface-treated with a silane coupling agent. The silane coupling agent is not particularly limited, and examples include silane coupling agents that have at least one selected from the group consisting of vinyl, acryloyl, methacryl, styrene, amino, and epoxy groups within the molecule.

[0146] The method for manufacturing the prepreg is not particularly limited as long as it can produce the prepreg. Specifically, when manufacturing the prepreg, the resin composition involved in this embodiment described above is mostly formulated into a varnish-like form and used as a resin varnish.

[0147] Specifically, a method for manufacturing prepreg 1 may include: impregnating the resin composition 2 (e.g., a resin composition 2 formulated into a varnish-like state) into a fibrous substrate 3 and then drying it. The impregnation of the resin composition 2 into the fibrous substrate 3 is carried out by impregnation and coating, etc. Impregnation can be repeated multiple times as needed. Furthermore, the final desired composition and impregnation amount can be adjusted by repeatedly impregnating with various resin compositions of different compositions and concentrations.

[0148] The fibrous substrate 3 impregnated with the resin composition (resin varnish) 2 is heated under desired heating conditions (e.g., heating at 40°C or higher and 180°C or lower for 1 minute or more and 10 minutes or less). Heating yields a prepreg 1 in a pre-cured (stage A) or semi-cured (stage B) state. It should be noted that the heating causes the organic solvent to evaporate from the resin varnish, thus reducing or eliminating the organic solvent.

[0149] [Metal Foil-Coated Laminate]

[0150] Figure 2 This is a schematic cross-sectional view illustrating an example of a metal foil laminate 11 according to an embodiment of the present invention.

[0151] like Figure 2 As shown, the metal-clad laminate 11 according to this embodiment includes: an insulating layer 12 comprising a cured product of the resin composition; and a metal foil 13 disposed on the insulating layer 12. Examples of metal-clad laminates 11 include those comprising... Figure 1 The insulating layer 12 is a cured prepreg 1; and a metal foil laminate with a metal foil 13 laminated together with the insulating layer 12. Furthermore, the insulating layer 12 can be formed from a cured resin composition or from a cured prepreg. The thickness of the metal foil 13 varies depending on the required performance of the final wiring board and is not particularly limited. The thickness of the metal foil 13 can be appropriately set according to the desired purpose, and is preferably 0.2 to 70 μm. Examples of metal foil 13 include copper foil and aluminum foil; in the case of a thinner metal foil, a carrier-supported copper foil with a release layer and a carrier can be used to improve operability.

[0152] As for the method of manufacturing the metal-clad laminate 11, there is no particular limitation as long as the metal-clad laminate 11 can be manufactured. Specifically, a method of using the prepreg 1 to manufacture the metal-clad laminate 11 can be cited. As a method, a method can be cited that involves taking one piece of the prepreg 1 or overlapping several pieces of the prepreg 1, and then overlapping a metal foil 13 such as copper foil on its upper and lower surfaces or one side surface, and heating and pressing the metal foil 13 and the prepreg 1 to form an integral laminate, thereby producing a laminate 11 with metal foil on both sides or one side surface. That is, the metal-clad laminate 11 is obtained by laminating the metal foil 13 on the prepreg 1 and heating and pressing it. In addition, the heating and pressing conditions can be appropriately set according to the thickness of the metal-clad laminate 11 or the type of resin composition contained in the prepreg 1. For example, the temperature can be set to 170 to 230°C, the pressure to 2 to 5 MPa, and the time to 60 to 150 minutes. Furthermore, the metal foil laminate can also be manufactured without using prepreg. Examples include methods such as coating a varnish-like resin composition onto a metal foil, forming a layer containing the resin composition on the metal foil, and then heating and pressurizing it.

[0153] [Wiring board]

[0154] Figure 3 This is a schematic cross-sectional view illustrating an example of a wiring board 21 according to an embodiment of the present invention.

[0155] like Figure 3 As shown, the wiring board 21 according to this embodiment includes: an insulating layer 12 comprising a cured product of the resin composition; and wiring 14 disposed on the insulating layer 12. Examples of wiring boards 21 include those comprising... Figure 1 The insulating layer 12 used after curing the prepreg 1 shown; and the wiring board 14 formed by laminating the insulating layer 12 together and removing a portion of the metal foil 13, etc. Furthermore, the insulating layer 12 can be formed from a cured product of the resin composition or from a cured product of the prepreg.

[0156] The method for manufacturing the wiring board 21 is not particularly limited as long as it can be manufactured. Specifically, methods such as using the prepreg 1 to manufacture the wiring board 21 can be listed. As a method, for example, etching the metal foil 13 on the surface of the metal foil laminate 11 manufactured as described above to form wiring, thereby manufacturing a wiring board 21 with wiring as a circuit on the surface of the insulating layer 12. That is, the wiring board 21 can be obtained by removing a portion of the metal foil 13 on the surface of the metal foil laminate 11 to form a circuit. In addition, as a method for forming a circuit, besides the methods described above, methods such as forming a circuit by a semi-additive process (SAP) or a modified semi-additive process (MSAP) can be listed.

[0157] [Resin-coated metal foil]

[0158] Figure 4 This is a schematic cross-sectional view showing an example of the resin-coated metal foil 31 involved in this embodiment.

[0159] like Figure 4 As shown, the resin-coated metal foil 31 according to this embodiment includes: a resin layer 32 comprising the resin composition or a semi-cured product of the resin composition; and a metal foil 13. The resin-coated metal foil 31 has the metal foil 13 on the surface of the resin layer 32. That is, the resin-coated metal foil 31 includes: the resin layer 32; and the metal foil 13 laminated together with the resin layer 32. Furthermore, the resin-coated metal foil 31 may also have other layers between the resin layer 32 and the metal foil 13.

[0160] The resin layer 32 may contain a semi-cured form of the resin composition as described above, or it may contain uncured resin composition. That is, the resin-coated metal foil 31 may be a resin layer comprising a semi-cured form of the resin composition (the resin composition of stage B) and a resin-coated metal foil, or it may be a resin layer comprising a resin composition before curing (the resin composition of stage A) and a resin-coated metal foil. Furthermore, the resin layer may or may not contain a fibrous substrate, as long as it contains the resin composition or a semi-cured form of the resin composition. Furthermore, the resin composition or the semi-cured form of the resin composition may be a substance obtained by drying or heating the resin composition. Furthermore, the same material as the fibrous substrate of the prepreg may be used as the fibrous substrate.

[0161] The metal foil can be any type of metal foil, including metal foil laminates and resin-coated metal foils. Examples of such metal foils include copper foil and aluminum foil.

[0162] The resin-coated metal foil 31 may be equipped with a cover film or the like as needed. The cover film helps prevent the introduction of foreign matter. The cover film is not particularly limited, and examples include polyolefin films, polyester films, polymethylpentene films, and films formed by applying a release agent layer to these films.

[0163] The method for manufacturing the resin-coated metal foil 31 is not particularly limited as long as it can produce the resin-coated metal foil 31. Examples of methods for manufacturing the resin-coated metal foil 31 include coating the metal foil 13 with the aforementioned varnish-like resin composition (resin varnish) and then heating it. For example, the varnish-like resin composition can be coated onto the metal foil 13 using a doctor blade coater. The coated resin composition is heated, for example, at a temperature of 40°C or higher and 180°C or lower, for a time of 0.1 minutes or higher and 10 minutes or lower. The heated resin composition forms an uncured resin layer 32 on the metal foil 13. It should be noted that by heating, the organic solvent evaporates from the resin varnish, thus reducing or removing the organic solvent.

[0164] [Resin-coated membrane]

[0165] Figure 5 This is a schematic cross-sectional view showing an example of the resin-coated membrane 41 according to this embodiment.

[0166] like Figure 5 As shown, the resin-bearing membrane 41 according to this embodiment includes: a resin layer 42 comprising the resin composition or a semi-cured product of the resin composition; and a support membrane 43. The resin-bearing membrane 41 includes: the resin layer 42; and the support membrane 43 laminated together with the resin layer 42. Furthermore, the resin-bearing membrane 41 may also have other layers between the resin layer 42 and the support membrane 43.

[0167] The resin layer 42 may contain a semi-cured form of the resin composition as described above, or it may contain uncured resin composition. That is, the resin-bearing membrane 41 may be a resin layer comprising: a semi-cured form of the resin composition (the resin composition of stage B); and a resin-bearing membrane supporting the membrane; or it may be a resin layer comprising: a resin composition before curing (the resin composition of stage A); and a resin-bearing membrane supporting the membrane. Furthermore, the resin layer may or may not contain a fibrous substrate, as long as it contains the resin composition or a semi-cured form of the resin composition. Furthermore, the resin composition or the semi-cured form of the resin composition may be a substance obtained by drying or heating the resin composition. Furthermore, the same material as the fibrous substrate of the prepreg may be used as the fibrous substrate.

[0168] As the support film 43, the support film used in resin-impregnated films can be used without limitation. Examples of such support films include electrically insulating films such as polyester films, polyethylene terephthalate (PET) films, polyimide films, polyethylene urea films, polyetheretherketone films, polyphenylene sulfide films, polyamide films, polycarbonate films, and polyarylate films.

[0169] The resin-coated membrane 41 may be equipped with a cover film or the like as needed. The cover film helps prevent the introduction of foreign matter. The cover film is not particularly limited, and examples include polyolefin films, polyester films, and polymethylpentene films.

[0170] The supporting film and the covering film can be films that have undergone surface treatments such as matte treatment, corona treatment, demolding treatment and roughening treatment as needed.

[0171] The method for manufacturing the resin-containing film 41 is not particularly limited as long as it is possible to manufacture the resin-containing film 41. Examples of methods for manufacturing the resin-containing film 41 include, for instance, coating the aforementioned varnish-like resin composition (resin varnish) onto a support film 43 and then heating it. For example, the varnish-like resin composition can be coated onto the support film 43 using a doctor blade coater. The coated resin composition is heated, for example, at a temperature of 40°C or higher and 180°C or lower, for a time of 0.1 minutes or higher and 10 minutes or lower. The heated resin composition forms an uncured resin layer 42 on the support film 43. It should be noted that by heating, the organic solvent evaporates from the resin varnish, thereby reducing or removing the organic solvent.

[0172] The resin composition involved in this embodiment is a resin composition capable of obtaining a cured product that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil. That is, the resin composition, after curing, becomes a cured product that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil. Therefore, the prepreg, after curing, becomes a cured product that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil. The resin-coated metal foil and the resin-coated film are resin-coated metal foils and resin-coated films having a resin layer comprising an insulating layer that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil. The metal-coated laminate and the wiring board are metal-coated laminates and wiring boards having an insulating layer comprising an insulating layer that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil. The prepreg, the resin-coated metal foil, the resin-coated film, and the metal foil-coated laminate can be used to manufacture wiring boards having an insulating layer comprising a cured material that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil. The prepreg, the resin-coated metal foil, the resin-coated film, and the metal foil-coated laminate can also be used, for example, in manufacturing multilayer wiring boards. If it is the resin-coated film, a multilayer wiring board can be manufactured, for example, by peeling off a support film after laminating it onto the wiring board, or by peeling off a support film and then laminating it onto the wiring board. If it is the resin-coated metal foil, a multilayer wiring board can be manufactured, for example, by laminating it onto the wiring board. As described above, by using the resin-coated film and the resin-coated metal foil, a multilayer wiring board having an insulating layer comprising a cured material that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to the metal foil can be manufactured. As a wiring board obtained by using the prepreg, the resin-coated metal foil, the resin-coated film, and the metal foil laminate, a wiring board having an insulating layer comprising a cured material that maintains excellent low dielectric properties and has excellent compatibility and adhesion to the metal foil can be obtained.

[0173] This specification discloses the techniques of various embodiments as described above, and the main technical features are summarized below.

[0174] The first technical solution of the present invention relates to a resin composition comprising: a pre-reaction product (A) obtained by pre-reacting a polyfunctional vinyl aromatic copolymer (a1) and a maleimide compound (a2), wherein the polyfunctional vinyl aromatic copolymer (a1) contains repeating units derived from a divinyl aromatic compound, and the maleimide compound (a2) has an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms.

[0175] The resin composition of the second technical solution of the present invention, in the resin composition of the first technical solution of the present invention, further contains repeating units derived from monovinyl aromatic compounds.

[0176] In the resin composition of the third technical solution of the present invention, the mass ratio of the polyfunctional vinyl aromatic copolymer (a1) to the maleimide compound (a2) is 10:90 to 90:10.

[0177] In the resin composition of any one of the first to third technical solutions of the present invention, the weight-average molecular weight of the maleimide compound (a2) is 500 to 4000.

[0178] The resin composition of the fifth technical solution of the present invention further contains, in any of the resin compositions of the first to fourth technical solutions of the present invention, an inorganic filler material.

[0179] The resin composition of the sixth technical solution of the present invention further contains a flame retardant in the resin composition of any one of the first to fifth technical solutions of the present invention.

[0180] The resin composition according to the seventh technical solution of the present invention further comprises, in any of the resin compositions according to the first to sixth technical solutions of the present invention, a reactive compound (B) that reacts with the pre-reaction product (A), wherein the reactive compound (B) comprises at least one selected from the group consisting of allyl compounds, methacrylate compounds, acrylate compounds, acenaphthene compounds, vinyl compounds, isocyanurate compounds, polyphenylene ether compounds having carbon-carbon unsaturated double bonds in the molecule, and maleimide compounds other than the maleimide compound (a2).

[0181] The eighth technical solution of the present invention relates to a prepreg comprising: a resin composition or a semi-cured product of the resin composition according to any one of the technical solutions of the first to seventh invention; and a fibrous substrate.

[0182] The ninth technical solution of the present invention relates to a resin-containing membrane, comprising: a resin layer comprising the resin composition or a semi-cured product of the resin composition according to any one of the first to seventh technical solutions of the present invention; and a support membrane.

[0183] The tenth technical solution of the present invention relates to a resin-coated metal foil, comprising: a resin layer containing the resin composition or a semi-cured product of the resin composition according to any one of the technical solutions 1 to 7 of the present invention; and a metal foil.

[0184] The 11th technical solution of the present invention relates to a metal foil laminate, comprising: an insulating layer comprising a cured resin composition of any one of the technical solutions 1 to 7 of the present invention; and a metal foil.

[0185] The 12th technical solution of the present invention relates to a metal foil laminate, comprising: an insulating layer comprising a cured prepreg of the 8th technical solution of the present invention; and a metal foil.

[0186] The 13th technical solution of the present invention relates to a wiring board, comprising: an insulating layer comprising a cured resin composition of any one of the technical solutions 1 to 7 of the present invention; and wiring.

[0187] The 14th technical solution of the present invention relates to a wiring board, which includes: an insulating layer comprising a cured prepreg of the 8th technical solution of the present invention; and wiring.

[0188] According to the present invention, a resin composition capable of producing a cured material that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to metal foil can be provided. Furthermore, according to the present invention, prepregs, resin-coated films, resin-coated metal foils, metal foil-coated laminates, and wiring boards obtained using the said resin composition can be provided.

[0189] The present invention will be further described in detail below through embodiments; however, the scope of the present invention is not limited to these embodiments.

[0190] Example

[0191] [Examples 1-3 and Comparative Examples 1-3]

[0192] The components used in preparing the resin composition in this embodiment will be described.

[0193] (Pre-reaction product (A))

[0194] Pre-reaction product 1: A pre-reaction product obtained by pre-reacting a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2).

[0195] Specifically, the pre-reaction product 1 is a pre-reaction product obtained by the following reaction.

[0196] The components used in the manufacture of the pre-reaction product 1 will be described.

[0197] Multifunctional vinyl aromatic copolymer: is the multifunctional vinyl aromatic copolymer (a1), specifically, is a multifunctional vinyl aromatic copolymer obtained by the following reaction.

[0198] 2.25 mol (292.9 g) of divinylbenzene, 1.32 mol (172.0 g) of ethylvinylbenzene, 11.43 mol (1190.3 g) of styrene, and 15.0 mol (1532.0 g) of n-propyl acetate were added to a 5.0 L reactor, and 600 mmol of boron trifluoride diethyl ether complex was added at 70 °C. The reaction was allowed to proceed for 4 hours. Then, to stop the reaction, an aqueous sodium bicarbonate solution was added to the resulting reaction solution. The oil layer was then washed three times with pure water, and the solid was recovered by vacuum evaporation at 60 °C. The obtained solid was weighed and confirmed to be 860.8 g.

[0199] The molecular weight and molecular weight distribution of the resulting solid (polymer) were determined using a GPC (HLC-8120GPC manufactured by Tosoh Corporation) with tetrahydrofuran as solvent, at a flow rate of 1.0 ml / min and a column temperature of 38 °C, using a monodisperse polystyrene calibration line. The results showed that the number-average molecular weight (Mn) of the obtained solid was 2060, the weight-average molecular weight (Mw) was 3070, and the Mw / Mn ratio was 14.9.

[0200] Using a JNM-LA600 nuclear magnetic resonance spectrometer manufactured by Nippon Electronics Corporation, and through... 13 C-NMR and 1 H-NMR analysis was used to determine the structure of the obtained solid (polymer). Chloroform-d1 was used as the solvent, and the resonance line of tetramethylsilane was used as an internal standard. In addition, besides... 13 C-NMR and 1 In addition to the H-NMR determination results, the amount of a specific structural unit introduced into the copolymer was calculated based on the total amount of each structural unit introduced into the copolymer obtained by GC analysis. Based on the amount of the specific structural unit introduced into the end and the number average molecular weight obtained by the GPC determination, the amount of side-chain vinyl units contained in the multifunctional vinyl aromatic copolymer was calculated.

[0201] The resulting solid was subjected to the process described above. 13 C-NMR and 1¹H-NMR analysis revealed resonance lines from each monomer unit. Furthermore, based on the NMR and GC analysis results, the solid was identified as the aforementioned polyfunctional vinyl aromatic copolymer. The structural units of this polyfunctional vinyl aromatic copolymer were calculated based on the NMR and GC analysis results as follows: 20.9 mol% (24.3 wt%) of structural units derived from divinylbenzene, 70.0 mol% (65.0 wt%) of structural units derived from styrene, 9.1 mol% (10.7 wt%) of structural units derived from ethylvinylbenzene, and 16.7 mol% (18.5 wt%) of structural units with residual vinyl groups derived from divinylbenzene.

[0202] Maleimide compound 1: the maleimide compound (a2) [BMI-689 manufactured by Designers Corporation, the maleimide compound represented by formula (8)].

[0203] 44.8 parts by weight of the polyfunctional vinyl aromatic copolymer and 5 parts by weight of the maleimide compound 1 were mixed and diluted with toluene to a solids concentration of 50% by weight. The mixture was stirred and mixed using a disperser at a liquid temperature of 100°C for 8 hours. Volatile components were recovered using a cooler each time. Through this operation, the polyfunctional vinyl aromatic copolymer and the maleimide compound 1 reacted to obtain pre-reaction product 1. The reaction rate was 60%.

[0204] Pre-reaction product 2: A pre-reaction product obtained by pre-reacting a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2).

[0205] Specifically, the pre-reaction product 2 is a pre-reaction product obtained by the following reaction.

[0206] Except that the mixing amount of the multifunctional vinyl aromatic copolymer was changed from 44.8 parts by mass to 42.4 parts by mass, and the mixing amount of maleimide compound 1 was changed from 5 parts by mass to 10 parts by mass, pre-reaction product 2 was obtained by the same method as pre-reaction product 1. The reaction rate was 50%.

[0207] Pre-reaction product 3: A pre-reaction product obtained by pre-reacting a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and maleimide compounds other than the maleimide compound (a2).

[0208] Specifically, the pre-reaction product 3 is a pre-reaction product obtained by the following reaction.

[0209] Pre-reaction product 3 was obtained by the same method as pre-reaction product 2, except that maleimide compound 2 (a maleimide compound without alkyl groups) was used instead of maleimide compound 1. The reaction rate was 50%.

[0210] Maleimide compound 2 (maleimide compound without alkyl groups): Maleimide compounds other than the maleimide compound (a2) mentioned above (maleimide compounds without alkyl groups having more than 6 carbons) [BMI-1500 manufactured by the designer molecular company, maleimide compound shown in formula (10) below]

[0211]

[0212] In equation (10), m represents 1 to 10.

[0213] (Reactive compound (B))

[0214] Acenaparene compounds: Acenaparene (manufactured by JFE Chemical Co., Ltd.)

[0215] Modified PPE: Polyphenylene ether compounds with methacryl groups at the ends (SA9000 manufactured by SABIC Innovative Plastics is a modified polyphenylene ether in which the terminal hydroxyl groups have been modified with methacryl groups, with a weight average molecular weight of Mw2000).

[0216] (Reaction initiator)

[0217] Peroxide: α,α'-Di(tert-butylperoxy)diisopropylbenzene (PERBUTYL P (PBP) manufactured by Nippon Oil Co., Ltd.)

[0218] Azo compound: 2,2'-azobis(2,4,4-trimethylpentane) (VR-110 manufactured by Fujifilm and Kazumitsu Chemical Co., Ltd.)

[0219] (Free radical compounds)

[0220] Free radical compound: 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxy radical (LA-7RD manufactured by Adico Co., Ltd.)

[0221] (Silane coupling agent)

[0222] Silane coupling agent: 3-methacryloyloxypropyltrimethoxysilane (a silane coupling agent with a methacryloyl group in the molecule, KBM503 manufactured by Shin-Etsu Chemical Co., Ltd.)

[0223] (Flame retardant)

[0224] Compatible phosphorus-based flame retardant: Aromatic polyphosphate compound (PX-200 manufactured by Daihachi Chemical Industry Co., Ltd.)

[0225] Incompatible phosphorus-based flame retardants: diphenylphosphine oxide compound (PQ60 manufactured by Jin Yi Chemical Co., Ltd.)

[0226] (Inorganic filler material)

[0227] Silica filler: EQ2410-SMC (TAT) manufactured by Zhejiang Sanshiji New Materials Technology Co., Ltd.

[0228] [Preparation Method]

[0229] First, all components except the inorganic filler were added to toluene according to the composition (parts by mass) listed in Table 1 and mixed to achieve a solids concentration of 35% by mass. The mixture was stirred for 60 minutes. Then, the inorganic filler was added to the resulting mixture according to the composition (parts by mass) listed in Table 1, and the inorganic filler was dispersed using a bead mill. This process yielded a varnish-like resin composition (varnish).

[0230] Next, the prepreg was obtained as follows.

[0231] The resulting varnish was impregnated into a fibrous substrate (glass cloth: Asahi Kasei Corporation, #1078 type, L2 glass), and then dried at 130°C for 3 minutes to produce a prepreg. At this time, the content of the component constituting the resin through the curing reaction relative to the prepreg (resin content) was adjusted to approximately 66% by mass. Furthermore, the curing thickness was adjusted to reach 77 μm.

[0232] An evaluation substrate (metal foil laminate) was obtained as follows.

[0233] Two sheets of the obtained prepreg were overlapped, and copper foil (CF-T4X-SV-18 manufactured by Fukuda Metal Foil Powder Industry Co., Ltd.) with a thickness of 18 μm was placed on both sides. This was used as a pressing substrate and heated to 200°C at a heating rate of 3°C / min. The substrate was then subjected to heating and pressurization at 200°C for 120 minutes and a pressure of 3 MPa, resulting in an evaluation substrate (metal foil laminate) with a resin layer thickness of approximately 154 μm on both sides bonded with copper foil.

[0234] The evaluation substrate prepared as described above was evaluated using the method shown below.

[0235] [Dielectric properties (relative permittivity Dk and dielectric loss factor Df)]

[0236] Copper foil was removed from the evaluation substrate by etching. Using the resulting substrate as a test piece, the relative permittivity and dielectric loss factor at 10 GHz were determined using the resonant cavity perturbation method. Specifically, the relative permittivity (Dk) and dielectric loss factor (Df) of the test piece at 10 GHz were measured using a network analyzer (Keysight Technologies N5230A). If the measured relative permittivity Dk was less than 3.5, it was considered "pass." Furthermore, if the measured dielectric loss factor Df was less than 0.00215, it was considered "pass."

[0237] [Copper foil peel strength]

[0238] The metal foil (copper foil) was peeled from the evaluation substrate (metal foil laminate), and the peel strength was determined according to JIS C 6481 (1996). Specifically, the copper foil was peeled from the evaluation substrate using a tensile testing machine at a speed of 50 mm / min, and the peel strength (N / mm) was measured. This peel strength is the copper foil peel strength, indicating that the higher it is, the better the adhesion to the metal foil (copper foil). If the measured copper foil peel strength exceeds 0.50 N / mm, it is considered acceptable.

[0239] [Interlayer peel strength]

[0240] The peel strength (N / mm) was measured by peeling the topmost insulating layer (prepreg) of the evaluation substrate (metal foil laminate) at a speed of 50 mm / min using a tensile testing machine. This peel strength is the interlayer peel strength, indicating that the higher the strength, the better the interlayer adhesion. If the interlayer peel strength obtained by measurement exceeds 0.45 N / mm, it is judged as "pass".

[0241] [Compatibility]

[0242] First, an evaluation substrate for compatibility evaluation was prepared. Specifically, the evaluation substrate for compatibility evaluation was prepared by coating a varnish-like resin composition (varnish) manufactured during the production of the evaluation substrate (metal foil laminate) onto a glass plate to achieve a cured thickness of 100 μm. The plate was then placed in a desiccator set to 120°C and heated for 3 minutes to obtain the evaluation substrate (film). The haze of the evaluation substrate (film) formed on the glass plate was measured using a spectrophotometer (CM-5 spectrophotometer manufactured by Konica Minolta Co., Ltd.). If the obtained haze was 2 or less, the compatibility was considered sufficiently high, and the result was judged as "pass". In this case, it is indicated as "pass" in Table 1. Conversely, if the obtained haze exceeded 2, the compatibility was considered insufficient. In this case, it is indicated as "fail" in Table 1.

[0243] [Glass transition temperature (Tg)]

[0244] Using a bare plate from which the metal foil (copper foil) had been removed from the evaluation substrate (metal foil laminate) through etching as a test piece, the glass transition temperature (Tg) of the cured resin composition was determined using a viscoelastic spectrometer "DMS6100" manufactured by Seiko Instruments Inc. Dynamic viscoelasticity (DMA) was performed in the bending module at a frequency of 10 Hz. The temperature at which tanδ reached its maximum at a heating rate of 5 °C / min from room temperature was defined as the glass transition temperature (Tg) (°C). The glass transition temperature (Tg) obtained at this time is shown in Table 1 as glass transition temperature 1. Then, after cooling to room temperature, the glass transition temperature (Tg) (°C) was measured using the same method as described above. The glass transition temperature (Tg) obtained at this time is shown in Table 1 as glass transition temperature 2. If both the glass transition temperature 1 and the glass transition temperature 2 obtained by measurement are 190 °C or higher, it is considered "qualified".

[0245] These results are shown in Table 1.

[0246]

[0247] As shown in Table 1, when the resin composition contains a pre-reaction product (A) obtained by pre-reacting a mixture comprising the polyfunctional vinyl aromatic copolymer (a1) and the maleimide compound (a2) (Examples 1-3), the resin composition yields a cured product with low dielectric properties and excellent adhesion to the metal foil, and with superior compatibility compared to the cured product without the pre-reaction product (A) (Comparative Examples 1-3). Furthermore, the resin compositions of Examples 1-3 are resin compositions that can yield cured products with high glass transition temperatures, excellent heat resistance, and excellent adhesion not only to the metal foil but also to interlayer adhesion.

[0248] This application is based on Japanese Patent Application No. 2023-202050, filed on November 29, 2023, the contents of which are included in this application.

[0249] To illustrate the invention, the present invention has been appropriately and sufficiently described above through embodiments. However, it should be recognized that those skilled in the art can readily make changes and / or modifications to the above embodiments. Therefore, any changes or modifications implemented by those skilled in the art that do not depart from the scope of protection of the claims set forth in the claims can be interpreted as being included within the scope of protection of the claims.

[0250] Industrial availability

[0251] According to the present invention, a resin composition capable of producing a cured material that maintains excellent low dielectric properties and exhibits excellent compatibility and adhesion to metal foil can be provided. Furthermore, according to the present invention, prepregs, resin-coated films, resin-coated metal foils, metal-coated laminates, and wiring boards obtained using the said resin composition can be provided.

Claims

1. A resin composition, characterized in that... contain: The pre-reaction product (A) is obtained by pre-reacting a mixture comprising a polyfunctional vinyl aromatic copolymer (a1) and a maleimide compound (a2), wherein the polyfunctional vinyl aromatic copolymer (a1) contains repeating units derived from a divinyl aromatic compound, and the maleimide compound (a2) has an alkyl group having 6 or more carbon atoms and an alkylene group having 6 or more carbon atoms.

2. The resin composition according to claim 1, characterized in that, The multifunctional vinyl aromatic copolymer also contains repeating units derived from monovinyl aromatic compounds.

3. The resin composition according to claim 1, characterized in that, The mass ratio of the multifunctional vinyl aromatic copolymer (a1) to the maleimide compound (a2) is 10:90 to 90:

10.

4. The resin composition according to claim 1, characterized in that, The weight-average molecular weight of the maleimide compound (a2) is 500 to 4000.

5. The resin composition according to claim 1, characterized in that... It also contains: Inorganic filler materials.

6. The resin composition according to claim 1, characterized in that... It also contains: Flame retardant.

7. The resin composition according to claim 1, characterized in that... It also contains: The reactive compound (B) reacts with the pre-reaction product (A). The reactive compound (B) comprises at least one selected from the group consisting of allyl compounds, methacrylate compounds, acrylate compounds, acenaphthene compounds, vinyl compounds, isocyanurate compounds, polyphenylene ether compounds having carbon-carbon unsaturated double bonds in the molecule, and maleimide compounds other than the maleimide compound (a2).

8. A prepreg, characterized in that... include: The resin composition or the semi-cured product of the resin composition according to any one of claims 1 to 7; as well as Fiber-based substrate.

9. A resin-coated membrane, characterized in that... include: A resin layer comprising the resin composition of any one of claims 1 to 7 or a semi-cured product of the resin composition; as well as Support membrane.

10. A resin-coated metal foil, characterized in that... include: A resin layer comprising the resin composition of any one of claims 1 to 7 or a semi-cured product of the resin composition; as well as Metal foil.

11. A metal foil-coated laminate, characterized in that... include: An insulating layer comprising a cured product of the resin composition according to any one of claims 1 to 7; as well as Metal foil.

12. A metal foil-coated laminate, characterized in that... include: An insulating layer comprising the cured prepreg of claim 8; as well as Metal foil.

13. A wiring board, characterized in that... include: An insulating layer comprising a cured product of the resin composition according to any one of claims 1 to 7; as well as wiring.

14. A wiring board, characterized in that... include: An insulating layer comprising the cured prepreg of claim 8; as well as wiring.

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