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 containing: a polyphenylene ether compound having at least one of groups represented by formula (1) and formula (2); a curing agent capable of reacting with the polyphenylene ether compound; a styrene polymer having structural units represented by formula (3) and formula (4); and an inorganic filler containing boron nitride, wherein the content of the inorganic filler is 100 to 320 parts by mass with respect to 100 parts by mass of the total of the polyphenylene ether compound, the curing agent, and the styrene polymer.

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 volume of information processing, mounting technologies such as high integration of semiconductor devices, high-density wiring, and multi-layering are becoming increasingly advanced. Furthermore, wiring boards used in various electronic devices are seeking solutions for high-frequency applications, such as millimeter-wave radar substrates used in automotive applications. For wiring boards used in various electronic devices, reducing signal transmission losses is required to improve signal transmission speed; this requirement is particularly important for wiring boards used in high-frequency applications. To meet this requirement, the substrate material used to construct the wiring boards used in various electronic devices is required to have a low dielectric constant and low dielectric loss factor.

[0003] As such a substrate material, for example, a PPE-containing resin composition containing PPE (polyphenylene ether), a cross-linking curable compound and a phosphaphenanthrene derivative has been proposed (Patent Document 1).

[0004] On the other hand, for electronic materials used in base stations, such as PA (power amplifier) ​​substrates, in addition to requiring low dielectric constant and dielectric loss factor, high thermal conductivity is also required. To date, as one method to improve the thermal conductivity of resin compositions, a technique using boron nitride as an inorganic filler with high thermal conductivity has been proposed (Patent Document 2 or Patent Document 3).

[0005] While the boron nitride filler described in Patent Documents 2 and 3 does improve the thermal conductivity of the resin composition, increasing the amount of boron nitride increases the moisture absorption rate of the resin composition. This is believed to be because boron nitride filler has a stable surface that does not react with the resin or coupling agent. Therefore, adding boron nitride to the resin composition creates horizontal voids that are invisible to the naked eye between the resin and the filler. Increased moisture absorption of the substrate material leads to disadvantages such as decreased peel strength, deteriorated electrical properties, and susceptibility to environmental (humidity) influences on quality. Furthermore, depending on the filler content, it can sometimes affect the formability of the resin composition.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Publication No. 2015-67700

[0009] Patent Document 2: Japanese Patent Publication No. 2013-241321

[0010] Patent Document 3: Japanese Patent Publication No. 2014-208818 Summary of the Invention

[0011] The present invention was made in view of the above circumstances, and its object is to provide a resin composition that can produce a cured product with low dielectric properties, high thermal conductivity, and low moisture absorption, and excellent formability. Furthermore, the present 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.

[0012] The inventors conducted various studies and found that the above-mentioned objectives could be achieved through the following configuration. Through further repeated studies, the inventors completed the present invention.

[0013] In other words, one aspect of the resin composition of the present invention comprises:

[0014] A polyphenylene ether compound having at least one of the groups shown in formula (1) and formula (2);

[0015] A curing agent capable of reacting with the polyphenylene ether compound;

[0016] Styrene-based polymers having the structural units shown in formulas (3) and (4) below; and

[0017] Inorganic fillers containing boron nitride, wherein,

[0018] The content of the inorganic filler is 100-320 parts by weight relative to a total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer.

[0019]

[0020] In formula (1), s represents an integer from 0 to 10, Z represents an aryl group, and R1 to R3 each independently represent a hydrogen atom or an alkyl group.

[0021]

[0022] In formula (2), R4 represents a hydrogen atom or an alkyl group.

[0023]

[0024] In equation (3), R 35 ~R 37 Each independently represents a hydrogen atom or an alkyl group, R 38 Indicates a hydrogen atom or an alkyl group.

[0025] In equation (4), R 39 ~R 42 Each independently represents a hydrogen atom or an alkyl group, in R 39 and R 40 When each is an alkyl group, R 41 and R 42 It is a hydrogen atom, or in R 41 and R 42 When each is an alkyl group, R 39 and R 40 It is a hydrogen atom. Attached Figure Description

[0026] Figure 1 This is a schematic cross-sectional view illustrating an example of a prepreg according to an embodiment of the present invention.

[0027] 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.

[0028] Figure 3 This is a schematic cross-sectional view illustrating an example of a wiring board according to an embodiment of the present invention.

[0029] 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.

[0030] 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

[0031] The embodiments of the present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0032] [Resin Composition]

[0033] The resin composition according to embodiments of the present invention contains:

[0034] A polyphenylene ether compound having at least one of the groups shown in formula (1) and formula (2);

[0035] A curing agent capable of reacting with the polyphenylene ether compound;

[0036] Styrene-based polymers having the structural units shown in formulas (3) and (4) below; and

[0037] Inorganic fillers containing boron nitride, wherein,

[0038] The content of the inorganic filler is 100-320 parts by weight relative to a total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer.

[0039]

[0040] In formula (1), s represents an integer from 0 to 10, Z represents an aryl group, and R1 to R3 each independently represent a hydrogen atom or an alkyl group.

[0041]

[0042] In formula (2), R4 represents a hydrogen atom or an alkyl group.

[0043]

[0044] In equation (3), R 35 ~R 37 Each independently represents a hydrogen atom or an alkyl group, R 38 Indicates a hydrogen atom or an alkyl group.

[0045] In equation (4), R 39 ~R 42 Each independently represents a hydrogen atom or an alkyl group, in R 39 and R 40 When each is an alkyl group, R 41 and R 42 It is a hydrogen atom, or in R 41 and R 42 When each is an alkyl group, R 39 and R 40 It is a hydrogen atom.

[0046] According to the aforementioned composition, a resin composition with low dielectric properties, high thermal conductivity, low moisture absorption, and excellent formability can be obtained. This is believed to be because by including boron nitride, which has high thermal conductivity, as an inorganic filler, and adding a styrene-based polymer with high gas barrier properties, water is difficult to penetrate into the resin composition.

[0047] That is, according to the present invention, a resin composition can be provided that yields a cured product with low dielectric properties, high thermal conductivity, and is not easily affected by changes in the external environment such as moisture (low moisture absorption), and has excellent formability. Furthermore, according to the present invention, by using said resin composition, high-performance prepregs, resin-coated films, resin-coated metal foils, metal-coated laminates, and wiring boards can be provided.

[0048] First, the components of the resin composition of this embodiment will be described.

[0049] (polyphenylene ether compound)

[0050] The polyphenylene ether compound used in this embodiment is not particularly limited as long as it has a group shown in formula (1) or formula (2) below. It is believed that by containing this modified polyphenylene ether compound, a resin composition in which a cured product with low dielectric properties and high heat resistance can be obtained can be formed.

[0051]

[0052] In formula (1), s represents an integer from 0 to 10. Furthermore, Z represents an arylene group. Additionally, R1 to R3 are independent of each other. That is, R1 to R3 can be the same group or different groups. Furthermore, R1 to R3 represent hydrogen atoms or alkyl groups.

[0053] It should be noted that in equation (1), when s is 0, it means that Z is directly bonded to the end of the polyphenylene ether.

[0054] The arylene group Z mentioned above is not particularly limited. Examples of such arylene groups include monocyclic aromatic groups such as phenylene; and polycyclic aromatic groups such as naphthalene rings, which are not monocyclic. Furthermore, the arylene group may also include derivatives formed by substituting the hydrogen atoms bonded to the aromatic ring with functional groups such as alkenyl, alkynyl, formyl, alkyl carbonyl, alkenyl carbonyl, or alkynyl carbonyl. Furthermore, the alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl.

[0055]

[0056] In formula (2), R4 represents a hydrogen atom or an alkyl group. The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl.

[0057] Preferred examples of substituents represented by formula (1) include substituents containing vinyl benzyl groups. Substituents containing vinyl benzyl groups include substituents represented by formula (6) below. Furthermore, substituents represented by formula (2) include acrylate groups and methacrylate groups.

[0058]

[0059] More specifically, examples of substituents include vinylbenzyl (ethylene benzyl) such as p-vinylbenzyl and m-vinylbenzyl, vinylphenyl, acrylate and methacrylate.

[0060] In the resin composition of this embodiment, it is more preferable that the polyphenylene ether compound has the group shown in formula (2). This is because it has the advantage of improving reactivity with the crosslinking agent and easily obtaining a resin cured with high heat resistance.

[0061] The polyphenylene ether compound has a polyphenylene ether chain in the molecule, preferably having a repeating unit as shown in formula (7) below.

[0062]

[0063] In formula (7), t represents 1 to 50. Furthermore, R5 to R8 are independent. That is, R5 to R8 can be the same group or different groups. Additionally, R5 to R8 represent hydrogen atoms, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. Preferably, hydrogen atoms and alkyl groups are used.

[0064] Among R5 to R8, the listed functional groups are specifically listed as follows.

[0065] The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl.

[0066] The alkenyl group is not particularly limited, but is preferably an alkenyl group with 2 to 18 carbon atoms, and more preferably an alkenyl group with 2 to 10 carbon atoms. Specifically, examples include vinyl, allyl, and 3-butenyl.

[0067] The alkynyl group is not particularly limited, but is preferably an alkynyl group with 2 to 18 carbon atoms, and more preferably an alkynyl group with 2 to 10 carbon atoms. Specifically, examples include ethynyl and prop-2-yn-1-yl (propynyl).

[0068] The alkyl carbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group. For example, it is preferred to be an alkyl carbonyl group with 2 to 18 carbon atoms, and more preferably an alkyl carbonyl group with 2 to 10 carbon atoms. Specifically, examples include acetyl, propionyl, butyryl, isobutyryl, neopentyl, hexanoyl, octanoyl, and cyclohexyl carbonyl.

[0069] The alkenyl carbonyl group is not particularly limited as long as it is a carbonyl group that has been substituted with an alkenyl group. For example, an alkenyl carbonyl group with 3 to 18 carbon atoms is preferred, and an alkenyl carbonyl group with 3 to 10 carbon atoms is more preferred. Specifically, examples include acryloyl, methacryl, and crotonyl groups.

[0070] The alkynyl carbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group. For example, an alkynyl carbonyl group with 3 to 18 carbon atoms is preferred, and an alkynyl carbonyl group with 3 to 10 carbon atoms is more preferred. Specifically, examples include propynyl groups, etc.

[0071] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polyphenylene ether compound are not particularly limited. Specifically, they are preferably 500 to 5000, more preferably 800 to 4000, and even more preferably 1000 to 3000. It should be noted that the weight-average molecular weight and number-average molecular weight can be values ​​obtained by conventional molecular weight determination methods, such as values ​​obtained by gel permeation chromatography (GPC). Furthermore, when the polyphenylene ether compound has repeating units as shown in formula (11) within its molecule, t is preferably a value that makes the weight-average molecular weight and number-average molecular weight of the polyphenylene ether compound fall within the above-mentioned ranges. Specifically, t is preferably 1 to 50.

[0072] If the molecular weight of the polyphenylene ether compound is within the above-mentioned range, the polyphenylene ether compound not only possesses the excellent low dielectric properties inherent in polyphenylene ethers, but also exhibits superior heat resistance and formability of the cured product. This is believed to be based on the following reasons. In conventional polyphenylene ethers, if their weight-average molecular weight and number-average molecular weight are within the above-mentioned range, the molecular weight is relatively low, thus tending to reduce the heat resistance of the cured product. Regarding this point, it is believed that since the polyphenylene ether compound involved in this embodiment has one or more unsaturated double bonds at the ends, the cured product can obtain sufficiently high heat resistance. Furthermore, it is believed that if the molecular weight of the polyphenylene ether compound is within the above-mentioned range, the formability is also excellent because the molecular weight is relatively low. Therefore, it is believed that this polyphenylene ether compound can achieve the effect of not only superior heat resistance of the cured product, but also excellent formability.

[0073] The average number of substituents (terminal functional groups) at the end of each molecule of the polyphenylene ether compound is not particularly limited. Specifically, it is preferably 1 to 5, more preferably 1 to 3, and even more preferably 1.5 to 3. If the number of terminal functional groups is too small, it tends to be difficult to obtain a cured product with sufficient heat resistance. Furthermore, if the number of terminal functional groups is too large, the reactivity becomes too high, and there is a risk of adverse conditions such as reduced shelf life of the resin composition or reduced flowability of the resin composition. That is, if this polyphenylene ether compound is used, problems with formability may occur due to insufficient flowability, for example, forming defects such as voids during multilayer molding, making it difficult to obtain a highly reliable printed wiring board.

[0074] It should be noted that the number of terminal functional groups in a polyphenylene ether compound can be exemplified by: a numerical value representing the average number of substituents in each molecule of all modified polyphenylene ether compounds present in 1 mole of the polyphenylene ether compound. This number of terminal functional groups can be determined, for example, by measuring the number of residual hydroxyl groups in the obtained modified polyphenylene ether compound and calculating the reduction in the number of hydroxyl groups compared to the number of hydroxyl groups in the unmodified polyphenylene ether. This reduction in the number of hydroxyl groups compared to the number of hydroxyl groups in the unmodified polyphenylene ether is the number of terminal functional groups. Furthermore, the number of residual hydroxyl groups in the modified polyphenylene ether compound can be determined by adding a quaternary ammonium salt (tetraethylammonium hydroxide) associated with hydroxyl groups to a solution of the modified polyphenylene ether compound and measuring the UV absorbance of the mixed solution.

[0075] The intrinsic viscosity of the polyphenylene ether compound in this embodiment is not particularly limited. Specifically, it is acceptable to have a viscosity of 0.03 to 0.12 dl / g, but preferably 0.04 to 0.11 dl / g, and more preferably 0.06 to 0.095 dl / g. If the intrinsic viscosity is too low, there is a tendency for a low molecular weight, and it is difficult to obtain low dielectric properties such as a low dielectric constant and a low dielectric loss factor. Furthermore, if the intrinsic viscosity is too high, the viscosity is high, making it difficult to obtain sufficient flowability, and there is a tendency for reduced formability of the cured product. Therefore, if the intrinsic viscosity of the polyphenylene ether compound is within the above range, excellent heat resistance and formability of the cured product can be achieved.

[0076] It should be noted that the intrinsic viscosity here refers to the intrinsic viscosity measured in dichloromethane at 25°C. More specifically, it is the value obtained by measuring a 0.18 g / 45 ml dichloromethane solution (liquid temperature 25°C) using a viscometer. Examples of such viscometers include the AVS500 Visco System manufactured by Schott.

[0077] Examples of the polyphenylene ether compounds used in this embodiment include, for example, the modified polyphenylene ether compound shown in formula (8) below and the modified polyphenylene ether compound shown in formula (9) below. Furthermore, these modified polyphenylene ether compounds can be used alone or in combination as the polyphenylene ether compounds used in this embodiment.

[0078]

[0079] In equations (8) and (9), R9~R 16 and R 17 ~R 24Each of the following groups independently represents a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. X1 and X2 each independently represent a substituent having a carbon-carbon unsaturated double bond. A and B represent the repeating units shown in formula (10) and formula (11) below, respectively. Furthermore, in formula (9), Y represents a straight-chain, branched, or cyclic hydrocarbon with 20 or fewer carbon atoms.

[0080]

[0081] In equations (10) and (11), m and n represent 0 to 20, respectively. 25 ~R 28 and R 29 ~R 32 Each can independently represent a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkyl carbonyl, alkenyl carbonyl, or alkynyl carbonyl.

[0082] The modified polyphenylene ether compound shown in formula (8) and the modified polyphenylene ether compound shown in formula (9) are not particularly limited as long as they satisfy the above-described composition. Specifically, in formulas (8) and (9), as described above, R9 to R 16 and R 17 ~R 24 Each is independent. That is, R9 to R 16 and R 17 ~R 24 They can be the same group or different groups. Furthermore, R9 to R... 16 and R 17 ~R24 represents a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. Preferably, it is a hydrogen atom or an alkyl group.

[0083] In equations (10) and (11), m and n are preferably represented as described above, from 0 to 20. Furthermore, regarding m and n, the sum of m and n is preferably represented as a value from 1 to 30. Therefore, more preferably, m represents 0 to 20, n represents 0 to 20, and the sum of m and n represents 1 to 30. Furthermore, R 25 ~R 28 and R 29 ~R 32 Each is independent. That is, R25~R 28 and R 29 ~R 32 They can be the same group or different groups. Furthermore, R... 25 ~R 28 and R 29 ~R 32It represents a hydrogen atom, alkyl, alkenyl, alkynyl, formyl, alkylcarbonyl, alkenylcarbonyl, or alkynylcarbonyl. Among them, hydrogen atom and alkyl are preferred.

[0084] R9~R 32 R5 to R8 are the same as those in equation (7) above.

[0085] In formula (9), as described above, Y is a straight-chain, branched, or cyclic hydrocarbon with 20 or fewer carbon atoms. Examples of Y include groups such as those shown in formula (12) below.

[0086]

[0087] In equation (12), R 33 and R 34 Each can be represented independently as a hydrogen atom or an alkyl group. Examples of alkyl groups include methyl. In addition, examples of groups represented by formula (12) include methylene, methylmethylene and dimethylmethylene, among which dimethylmethylene is preferred.

[0088] In formulas (8) and (9), X1 and X2 are each independently a substituent having a carbon-carbon unsaturated double bond. There is no particular limitation as long as the substituent X1 and X2 have a carbon-carbon unsaturated double bond. Examples of substituents X1 and X2 include the substituents shown in formula (1) and formula (2) above. It should be noted that in the modified polyphenylene ether compound shown in formula (8) and the modified polyphenylene ether compound shown in formula (9), X1 and X2 can be the same substituent or different substituents.

[0089] As a more specific example of the modified polyphenylene ether compound represented by formula (8), examples such as the modified polyphenylene ether compound represented by formula (13) below can be cited.

[0090]

[0091] As more specific examples of the modified polyphenylene ether compound represented by formula (9), examples include the modified polyphenylene ether compound represented by formula (14) below and the modified polyphenylene ether compound represented by formula (15) below.

[0092]

[0093] In equations (13) to (15) above, m and n are the same as m and n in equations (10) and (11) above. Furthermore, in equations (13) and (14) above, R1 to R3, p, and Z are the same as R1 to R3, s, and Z in equation (1) above. Furthermore, in equations (14) and (15) above, Y is the same as Y in equation (9) above. Furthermore, in equation (14) above, R4 is the same as R4 in equation (2) above.

[0094] The method for synthesizing the polyphenylene ether compound used in this embodiment is not particularly limited as long as it can synthesize a polyphenylene ether compound whose end groups have been modified by the groups shown in formula (1) and / or formula (2). Specifically, methods such as reacting polyphenylene ether with a compound having substituents having carbon-carbon unsaturated double bonds and halogen atoms can be cited.

[0095] Examples of compounds having substituents with carbon-carbon unsaturated double bonds and halogen atoms include, for example, compounds having substituents and halogen atoms as shown in formulas (1), (2), and (6). Specifically, examples of halogen atoms include chlorine atoms, bromine atoms, iodine atoms, and fluorine atoms, with chlorine atoms being preferred. More specifically, examples of compounds having substituents with carbon-carbon unsaturated double bonds and halogen atoms include p-chloromethylstyrene or m-chloromethylstyrene.

[0096] The polyphenylene ether used as a raw material is not particularly limited as long as it can ultimately synthesize the specified modified polyphenylene ether compound. Specifically, examples include compounds whose main component is a polyphenylene ether containing "2,6-dimethylphenol" and "at least one of bifunctional and trifunctional phenols," or poly(2,6-dimethyl-1,4-phenylene ether). Furthermore, a bifunctional phenol is a phenolic compound having two phenolic hydroxyl groups within its molecule, such as tetramethylbisphenol A. A trifunctional phenol is a phenolic compound having three phenolic hydroxyl groups within its molecule.

[0097] The method for synthesizing the polyphenylene ether compound in this embodiment can be exemplified by the methods described above. Specifically, the polyphenylene ether as described above is dissolved in a solvent with a compound having substituents having carbon-carbon unsaturated double bonds and halogen atoms, and the mixture is stirred. Thus, the polyphenylene ether reacts with the compound having substituents having carbon-carbon unsaturated double bonds and halogen atoms to obtain the polyphenylene ether compound used in this embodiment.

[0098] The reaction is preferably carried out in the presence of an alkali metal hydroxide. It is believed that this operation facilitates the reaction. The reason for this is that the alkali metal hydroxide acts as a dehydrohalogenating agent, specifically as a dehydrochlorinating agent. That is, it is believed that the alkali metal hydroxide causes hydrogen halide to desorb from the phenolic group of polyphenylene ether and the compound bonded with substituents having carbon-carbon unsaturated double bonds and halogen atoms. As a result, the substituents having carbon-carbon unsaturated double bonds replace the hydrogen atoms of the phenolic group of polyphenylene ether and bond to the oxygen atoms of the phenolic group.

[0099] Alkali metal hydroxides are not particularly limited in their application as long as they can function as dehalogenating agents; examples include sodium hydroxide. Furthermore, alkali metal hydroxides are typically used in aqueous solutions, specifically as an aqueous solution of sodium hydroxide.

[0100] The reaction time and temperature vary depending on the compound containing substituents with carbon-carbon unsaturated double bonds and halogen atoms, and are not particularly limited as long as the conditions allow the above reaction to proceed well. Specifically, the reaction temperature is preferably room temperature to 100°C, more preferably 30 to 100°C. Furthermore, the reaction time is preferably 0.5 to 20 hours, more preferably 0.5 to 10 hours.

[0101] The solvent used in the reaction is not particularly limited, as long as it can dissolve polyphenylene ether in relation to compounds with substituents and halogen atoms bonded with carbon-carbon unsaturated double bonds, and does not hinder the reaction between polyphenylene ether and these compounds. Specifically, toluene, etc., can be cited as an example.

[0102] It is preferable to carry out the above reaction in the presence of both an alkali metal hydroxide and a phase transfer catalyst. That is, it is preferable to carry out the above reaction in the presence of both an alkali metal hydroxide and a phase transfer catalyst. It is believed that this operation facilitates the reaction. This is based on the following reasoning: The phase transfer catalyst is a catalyst that has the function of introducing an alkali metal hydroxide, is soluble in both a polar solvent phase such as water and a non-polar solvent phase such as an organic solvent, and is capable of moving between these phases. Specifically, it is believed that when an aqueous sodium hydroxide solution is used as the alkali metal hydroxide and an organic solvent such as toluene, which is incompatible with water, is used as the solvent, even if the aqueous sodium hydroxide solution is added dropwise to the solvent used for the reaction, the solvent and the aqueous sodium hydroxide solution will separate, and sodium hydroxide is difficult to migrate into the solvent. Therefore, it is believed that the aqueous sodium hydroxide solution added as an alkali metal hydroxide is unlikely to help promote the reaction. In contrast, it is believed that if the reaction is carried out in the presence of alkali metal hydroxide and a phase transfer catalyst, the alkali metal hydroxide will migrate into the solvent under the condition of being introduced into the phase transfer catalyst, and the sodium hydroxide aqueous solution becomes more conducive to promoting the reaction. Therefore, it is believed that the above reaction will proceed more smoothly if the reaction is carried out in the presence of alkali metal hydroxide and a phase transfer catalyst.

[0103] There are no particular limitations on phase transfer catalysts; examples include quaternary ammonium salts such as tetra-n-butylammonium bromide.

[0104] The resin composition used in this embodiment preferably includes: the modified polyphenylene ether compound obtained as described above, as the polyphenylene ether compound.

[0105] (Curing agent)

[0106] The resin composition of this embodiment also contains a curing agent that can react with the polyphenylene ether compound.

[0107] As the curing agent, there is no particular limitation as long as it is a curing agent capable of reacting with the polyphenylene ether compound to cure the resin composition containing the polyphenylene ether compound. Examples of curing agents include those having at least one functional group within the molecule that facilitates reaction with the polyphenylene ether compound.

[0108] Specifically, examples include compounds having two or more unsaturated double bonds within a molecule. More specifically, examples include styrene derivatives, compounds having an acryloyl group within a molecule, compounds having a methacryloyl group within a molecule, compounds having a vinyl group within a molecule, compounds having an allyl group within a molecule, compounds having a maleimide group within a molecule, compounds having an acenaphthene structure within a molecule, and isocyanurate compounds having an isocyanurate group within a molecule.

[0109] Examples of styrene derivatives include bromostyrene and dibromostyrene.

[0110] The compound having an acryloyl group within its molecule is an acrylate compound. 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 tricyclodecanediethanol diacrylate.

[0111] The compound having a methacryl group within its molecule is a methacrylate compound. 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 tricyclodecanediethanol dimethacrylate.

[0112] The compound having a vinyl group within its molecule is a vinyl compound. Examples of such vinyl compounds include monofunctional vinyl compounds having one vinyl group within their molecule (monofunctional vinyl compounds) and polyfunctional vinyl compounds having two or more vinyl groups within their molecule. Examples of such polyfunctional vinyl compounds include, for instance, divinylbenzene and polybutadiene.

[0113] The compound having an allyl group within its molecule is an allyl compound. Examples of such allyl compounds include monofunctional allyl compounds having one allyl group within their molecule, and polyfunctional allyl compounds having two or more allyl groups within their molecule. Examples of such polyfunctional allyl compounds include diallyl phthalate (DAP).

[0114] The compound having a maleimide group within its molecule is a maleimide compound. Examples of such maleimide compounds include: monofunctional maleimide compounds having one maleimide group within their molecule; polyfunctional maleimide compounds having two or more maleimide groups within their molecule; and modified maleimide compounds. Examples of such modified maleimide compounds include: modified maleimide compounds in which a portion of the molecule is modified by an amine compound; modified maleimide compounds in which a portion of the molecule is modified by an organosilicon compound; and modified maleimide compounds in which a portion of the molecule is modified by both an amine compound and an organosilicon compound.

[0115] The compound having an intramolecular acenaphthene structure is an acenaphthene compound. 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.

[0116] The compound having an isocyanurate group within the molecule is an isocyanurate compound. Examples of such isocyanurate compounds include compounds that further have an alkenyl group within the molecule (alkenyl isocyanurate compounds), such as trialenyl isocyanurate compounds like trialenyl isocyanurate (TAIC).

[0117] Regarding the curing agent used in this embodiment, among the above, the preferred examples are: polyfunctional acrylate compounds having two or more acryloyl groups in the molecule, polyfunctional methacrylate compounds having two or more methacryloyl groups in the molecule, polyfunctional vinyl compounds having two or more vinyl groups in the molecule, styrene derivatives, allyl compounds having allyl groups in the molecule, maleimide compounds having maleimide groups in the molecule, acenaphthene compounds having an acenaphthene structure in the molecule, and isocyanurate compounds having isocyanurate groups in the molecule.

[0118] Regarding the curing agent, it can be used alone or in combination of two or more.

[0119] The weight-average molecular weight of the curing agent is preferably 100-5000, more preferably 100-4000, and even more preferably 100-3000. If the weight-average molecular weight of the curing agent is too low, there is a risk that the curing agent may easily volatilize from the compounding system of the resin composition. Furthermore, if the weight-average molecular weight of the curing agent is too high, there is a risk that the viscosity of the varnish of the resin composition and the melt viscosity during heat molding may become too high. Therefore, if the weight-average molecular weight of the curing agent is within this range, a resin composition with superior heat resistance of the cured product can be obtained. The reason for this is that the resin composition containing the polyphenylene ether compound can be well cured through reaction with the polyphenylene ether compound. It should be noted that here, the weight-average molecular weight can be any value obtained by conventional molecular weight determination methods, such as values ​​measured by gel permeation chromatography (GPC).

[0120] Regarding the curing agent, the average number of functional groups (functional group number) in each molecule of the curing agent that contribute to the reaction with the polyphenylene ether compound varies depending on the weight-average molecular weight of the curing agent, and is preferably 1 to 20, more preferably 2 to 18. If the number of functional groups is too small, it tends to be difficult to obtain a cured product with sufficient heat resistance. Furthermore, if the number of functional groups is too large, the reactivity becomes too high, and there is a risk of adverse conditions such as reduced shelf life of the resin composition or reduced flowability of the resin composition.

[0121] (Styrene-based polymers)

[0122] The styrene-based polymer used in this embodiment has the structural units shown in formulas (3) and (4) below.

[0123]

[0124] In equation (3), R 35 ~R 37 Each independently represents a hydrogen atom or an alkyl group, R 38 The term "alkyl" refers to a hydrogen atom or an alkyl group. The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl. The styrene-based polymer of this embodiment contains at least one structural unit shown in formula (3) above, but may also contain two or more different structural units. Furthermore, a structure containing repeated structural units as shown in formula (3) above is preferred.

[0125] In equation (4), R 39 ~R 42 Each independently represents a hydrogen atom or an alkyl group, and in R 39and R 40 When each is an alkyl group, R 41 and R 42 It is a hydrogen atom, or in R 41 and R 42 When each is an alkyl group, R 39 and R 40 The alkyl group is a hydrogen atom. The alkyl group is not particularly limited, but is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specifically, examples include methyl, ethyl, propyl, hexyl, and decyl. The styrene-based polymer of this embodiment contains at least one structural unit shown in formula (4) above, but may also contain two or more different structural units. Furthermore, it may contain a structure with repeated structural units shown in formula (4) above.

[0126] In the styrene-based polymer, the molar percentage of the structural unit represented by formula (3) is preferably about 5 to 50 mol% relative to the total polymer. This provides the advantage of ensuring compatibility with the resin. Furthermore, it is preferably 10 to 40 mol% relative to the total polymer. This not only provides the advantage of maintaining compatibility with the resin but also the advantage of maintaining sufficient gas barrier properties in the resin composition. The polymerization morphology of the styrene-based polymer is not particularly limited and can be a block copolymer, alternating copolymer, random copolymer, graft copolymer, etc., preferably a block copolymer. Furthermore, the form can be any one of liquid, solid, or elastomer.

[0127] The weight-average molecular weight and number-average molecular weight of the styrene-based polymer in this embodiment are not particularly limited, but are preferably around 10,000 to 200,000. From the viewpoint of resin flowability, the average molecular weight is more preferably 50,000 to 150,000, and even more preferably 20,000 to 100,000. If the weight-average molecular weight and number-average molecular weight are within the above ranges, it has the advantage of ensuring appropriate resin flowability in the cured resin. It should be noted that here, the weight-average molecular weight and number-average molecular weight are simply values ​​obtained by conventional molecular weight determination methods, such as values ​​obtained by gel permeation chromatography.

[0128] Preferably, at least a portion of the structural units represented by formula (4) contained in the styrene-based polymer of this embodiment are structural units represented by formula (5) below. Furthermore, it is preferable to have a structure in which the structural units represented by formula (5) below are repeated.

[0129]

[0130] In a preferred embodiment, more preferably, the styrene-based polymer comprises a styrene-isobutylene-styrene block copolymer (SIBS) containing structural units as shown in formula (16). Accordingly, it has the advantage of obtaining a resin composition with high gas barrier properties and the ability to suppress moisture absorption of the resin composition.

[0131]

[0132] In equation (16), the sum of a1 and a2 represents an integer from 1000 to 60000, b represents an integer from 1000 to 70000, and the sum of a1, a2 and b represents 10000 to 130000.

[0133] The method for manufacturing the styrene-based polymer in this embodiment is not particularly limited. For example, taking the SIBS manufacturing method as an example, isobutylene is first polymerized by living cationic polymerization, and then styrene is added for polymerization, thereby synthesizing the polymer.

[0134] The styrene-based polymers used in this embodiment can also be commercially available products, such as "SIBSTAR (registered trademark) 073T", "SIBSTAR (registered trademark) 103T", and "SIBSTAR (registered trademark) 102T" manufactured by Kaneka Corporation.

[0135] (Inorganic filler)

[0136] The resin composition according to this embodiment further contains an inorganic filler comprising boron nitride. The boron nitride is not particularly limited as long as it can be used as an inorganic filler contained in the resin composition. Examples of boron nitride include, for instance, the hexagonal atmospheric pressure phase (h-BN) and the cubic high pressure phase (c-BN).

[0137] In this embodiment, the average particle size of boron nitride is preferably 0.5 to 20 μm, more preferably 2 to 18 μm. If the boron nitride is too small, the thermal conductivity and heat resistance of the cured resin composition tend to be insufficiently improved. Furthermore, if the boron nitride is too large, the formability of the resulting resin composition tends to decrease. Therefore, if the average particle size of the boron nitride is within the above-mentioned range, a resin composition with high thermal conductivity and heat resistance can be obtained more effectively. It should be noted that the average particle size here refers to the volume average particle size. The volume average particle size can be measured by, for example, laser diffraction. In addition, as the boron nitride in this embodiment, two or more boron nitride fillers with different average particle sizes included in the boron nitride filler within the above-mentioned range can be used.

[0138] The resin composition of this embodiment may also contain inorganic fillers other than boron nitride. There are no particular limitations on the inorganic filler other than boron nitride, as long as it can be used as an inorganic filler in the resin composition. Examples of inorganic fillers other than boron nitride include: metal oxides such as silicon dioxide, aluminum oxide, titanium oxide, magnesium oxide, and mica; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; talc; aluminum borate; barium sulfate; aluminum nitride; silicon nitride; magnesium carbonate such as anhydrous magnesium carbonate; and calcium carbonate. Among these, silicon dioxide, anhydrous magnesium carbonate, aluminum oxide, and silicon nitride are preferred as inorganic fillers other than boron nitride. The silicon dioxide is not particularly limited; examples include pulverized silicon dioxide and silicon dioxide particles, but silicon dioxide particles are preferred. Furthermore, the magnesium carbonate is not particularly limited; anhydrous magnesium carbonate (synthetic magnesite) is preferred.

[0139] The inorganic filler other than boron nitride can be a surface-treated inorganic filler or an untreated inorganic filler. Furthermore, examples of surface treatment include treatment with a silane coupling agent.

[0140] Examples of silane coupling agents include silane coupling agents having at least one functional group selected from the group consisting of vinyl, styrene, methacryl, acryloyl, and phenylamino. Specifically, examples of such silane coupling agents include compounds having at least one reactive functional group selected from vinyl, styrene, methacryl, acryloyl, and phenylamino, and having hydrolyzable groups such as methoxy or ethoxy groups.

[0141] 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 methacryloyl-containing silane coupling agents include 3-methacryloyloxypropyltrimethoxysilane, 3-methacryloyloxypropylmethyldimethoxysilane, 3-methacryloyloxypropyltriethoxysilane, 3-methacryloyloxypropylmethyldiethoxysilane, and 3-methacryloyloxypropylethyldiethoxysilane. Examples of acryloyl-containing silane coupling agents 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.

[0142] The average particle size of the inorganic filler other than boron nitride is preferably 0.5 to 10 μm, more preferably 0.5 to 8 μm. If the inorganic filler other than boron nitride is too small, the heat resistance of the cured resin composition may not be sufficiently improved. Furthermore, if the inorganic filler other than boron nitride is too large, the heat resistance of the cured resin composition may also not be sufficiently improved. This is believed to be based on the following reasons. First, it is believed that because the size difference between the inorganic filler other than boron nitride and the boron nitride becomes smaller, the inorganic filler other than boron nitride is difficult to exist between the boron nitride particles. Therefore, it is believed that the effect of improving heat resistance by the presence of the inorganic filler other than boron nitride between the boron nitride particles cannot be fully realized. Therefore, if the average particle size of the inorganic filler other than boron nitride is within the above range, a resin composition with high thermal conductivity and heat resistance can be better obtained. It should be noted that the average particle size here refers to the volume average particle size. The volume average particle size can be measured by, for example, laser diffraction.

[0143] Furthermore, the content of the inorganic filler in the resin composition of this embodiment is 100 to 320 parts by weight relative to the total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer. A more preferred content is 100 to 270 parts by weight, and even more preferably 100 to 220 parts by weight. If the content is less than 100 parts by weight, sufficient thermal conductivity cannot be obtained, while if it exceeds 320 parts by weight, the formability deteriorates. In other words, if the content of the inorganic filler is within this range, a resin composition that can produce a cured product with high thermal conductivity and excellent formability can be provided.

[0144] It should be noted that when the inorganic filler in this embodiment contains an inorganic filler other than boron nitride, the mass ratio of boron nitride to the inorganic filler other than boron nitride (boron nitride: other than boron nitride) is preferably 1:4 to 7:1, more preferably 1:2 to 3:1. Furthermore, when the inorganic filler other than boron nitride is silicon dioxide, the mass ratio of silicon dioxide to boron nitride (silicon dioxide: boron nitride) is preferably 80 to 20:20 to 80, more preferably 75 to 25:25 to 75.

[0145] (Content of each component)

[0146] In the resin composition of this embodiment, the content of the polyphenylene ether compound is preferably 50 to 90 parts by mass, more preferably 50 to 80 parts by mass, and even more preferably 50 to 70 parts by mass, relative to a total of 100 parts by mass of the polyphenylene ether compound, the curing agent, and the styrene-based polymer. That is, the content of the polyphenylene ether compound is preferably 50 to 90% by mass relative to the components in the resin composition other than the inorganic filler. It is believed that if the content of the polyphenylene ether compound is within the above range, a resin composition that can reliably obtain a cured product with low dielectric properties and high heat resistance can be obtained more reliably.

[0147] Furthermore, relative to the total 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer in the resin composition, the content of the curing agent is preferably 5 to 30 parts by weight, more preferably 15 to 30 parts by weight. If the content of the curing agent is within the above range, it can result in a resin composition with superior heat resistance of the cured product. This is because the curing reaction between the resin components and the curing agent in this embodiment proceeds well.

[0148] Furthermore, relative to a total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer in the resin composition, the content of the styrene-based polymer is preferably 5 to 25 parts by weight, more preferably 10 to 20 parts by weight. It is believed that if the content of the styrene-based polymer is within the above range, the moisture absorption rate of the resin composition can be suppressed, and the deterioration of electrical properties caused by the increase in moisture absorption can be more reliably suppressed.

[0149] (Other ingredients)

[0150] The resin composition according to this embodiment may, as needed, contain other components besides those described above without impairing the effects of the present invention. Other components included in the resin composition according to this embodiment may further include additives such as reaction initiators, silane coupling agents, flame retardants, defoamers, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes or pigments, dispersants, and lubricants. Furthermore, in addition to the polyphenylene ether compound, the curing agent, and the polymer described above, the resin composition of this embodiment may also contain other thermosetting resins such as epoxy resins, maleimide resins, aromatic resins, and aliphatic hydrocarbon resins.

[0151] The resin composition according to this embodiment may contain a reaction initiator (initiator) as described above. Even if the resin composition contains the polyphenylene ether compound, the curing agent, and the polymer, it can still undergo a curing reaction. However, depending on the process conditions, it is sometimes difficult to raise the temperature until curing occurs; therefore, a reaction initiator may be added.

[0152] The reaction initiator is not particularly limited as long as it can promote the curing reaction of the resin composition. Specifically, examples include metal oxides, azo compounds, and organic peroxides.

[0153] As metal oxides, examples include metal salts of carboxylic acids.

[0154] Examples of organic peroxides include: α,α′-di(tert-butylperoxy)diisopropylbenzene, 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, tert-butylperoxyisopropyl monocarbonate, azobisisobutyronitrile, etc.

[0155] As azo compounds, examples include 2,2′-azobis(2,4,4-trimethylpentane), 2,2′-azobis(N-butyl-2-methylpropionamide), and 2,2′-azobis(2-methylbutyronitrile).

[0156] Preferred reaction initiators include 2,2′-azobis(2,4,4-trimethylpentane) and 2,2′-azobis(N-butyl-2-methylpropionamide). These reaction initiators have minimal impact on dielectric properties. Furthermore, they offer the advantage that, due to their relatively high reaction initiation temperature, the promotion of the curing reaction can be suppressed during prepreg drying and other times when curing is not required, thus preventing a decrease in the shelf life of the resin composition.

[0157] The reaction initiators described above can be used alone or in combination of two or more.

[0158] When the resin composition of this embodiment contains the reaction initiator, its content is not particularly limited. For example, it is preferably 0.5 to 2.0 parts by weight, more preferably 0.8 to 1.5 parts by weight, and even more preferably 0.9 to 1.0 parts by weight, relative to a total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer.

[0159] (Manufacturing method)

[0160] The method for manufacturing the resin composition is not particularly limited, and examples include: mixing the polyphenylene ether compound, the curing agent, the styrene-based polymer, and other components to be added as needed, and then adding an inorganic filler. Specifically, when a varnish-like composition containing an organic solvent is obtained, the method described in the following description of the prepreg can be cited.

[0161] Furthermore, 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.

[0162] Preferably, the cured resin composition has a thermal conductivity of 1.0 W / m·K or higher and a dielectric loss factor of 0.003 or lower at a frequency of 10 GHz. As described above, by using the resin composition of this embodiment, both high thermal conductivity and low dielectric properties of the cured product can be achieved. Furthermore, since the cured product can suppress moisture absorption, it has the significant advantage of being less susceptible to changes in the external environment such as moisture. In addition, the resin composition of this embodiment exhibits excellent formability.

[0163] [Prepreg]

[0164] Figure 1 This is a schematic cross-sectional view illustrating an example of the prepreg 1 according to an embodiment of the present invention. It should be noted that in the following description, the reference numerals are as follows: 1 prepreg; 2 resin composition or semi-cured resin composition; 3 fibrous substrate; 11 metal foil laminate; 12 insulating layer; 13 metal foil; 14 wiring; 21 wiring board; 31 resin-coated metal foil; 32, 42 resin layers; 41 resin-coated film; 43 support film.

[0165] 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 the fibrous substrate 3 present in the resin composition or the semi-cured product of the resin composition 2.

[0166] 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 gradually, then curing begins, and then the viscosity gradually increases. In this case, the state from the start of viscosity increase to the point before complete curing can be listed as a semi-cured product.

[0167] Furthermore, the prepreg obtained using the resin composition according to this embodiment can be, as described above, a prepreg containing a semi-cured product of the resin composition, or 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 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.

[0168] In the manufacture of prepregs, the resin composition 2 is usually formulated into a varnish-like form to impregnate the fibrous substrate 3 used to form the prepreg. That is, the resin composition 2 is usually 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.

[0169] First, the components of the resin composition that are soluble in an organic solvent are added to the organic solvent and dissolved. Heating may be performed at this time if necessary. Then, components that are insoluble in the organic solvent (e.g., inorganic fillers, etc.) 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 modified polyphenylene ether compound and the curing agent without hindering the curing reaction. Examples of suitable organic solvents include toluene and methyl ethyl ketone (MEK).

[0170] 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 used in this embodiment is mostly formulated into a varnish-like form and used as a resin varnish, as described above.

[0171] Examples of fibrous substrates include, for example, glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and lint 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, a 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 typically used is, for example, 0.01 mm or more and 0.3 mm or less.

[0172] 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.

[0173] As a method for manufacturing prepreg 1, examples include: impregnating a resin composition 2 (e.g., a resin composition 2 prepared into a varnish-like state) into a fibrous substrate 3 and then drying it. 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 multiple resin compositions of different compositions or concentrations.

[0174] A fibrous substrate 3 impregnated with a resin composition (resin varnish) 2 is heated under desired heating conditions (e.g., heating at 80°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 removing the organic solvent.

[0175] The prepreg containing the resin composition or semi-cured product of the resin composition described in this embodiment is a prepreg that can suitably produce a cured product with low dielectric properties, high thermal conductivity, and is not easily affected by changes in the external environment such as moisture (low moisture absorption). In addition, the prepreg of this embodiment also has good formability.

[0176] [Metal Foil Coated Laminate]

[0177] 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.

[0178] like Figure 2 As shown, the metal foil-coated laminate 11 includes: Figure 1The insulating layer 12 is a cured prepreg 1, and a metal foil 13 is laminated together with the insulating layer 12. That is, the metal foil laminate 11 includes: an insulating layer 12 comprising a cured resin composition; and a metal foil 13 disposed on the insulating layer 12. Furthermore, the insulating layer 12 can be formed from the cured resin composition or from the cured prepreg. Furthermore, 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, for example, preferably 0.2 to 70 μm. Furthermore, examples of the metal foil 13 include copper foil and aluminum foil; when the metal foil is thin, to improve processability, it can be a copper foil with a release layer and a carrier.

[0179] 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 manufacturing the metal-clad laminate 11 using prepreg 1 can be cited. As a method, a method can be cited that involves taking one piece of prepreg 1 or stacking several pieces of prepreg 1, and then stacking 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 a laminate integrally, thereby manufacturing a laminate 11 with metal foil on both sides or one side surface. That is, the metal-clad laminate 11 is obtained by stacking 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 being manufactured or the type of composition of the prepreg 1. For example, the temperature can be set to 170 to 210°C, the pressure to 3.5 to 4 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 subjecting it to heating and pressure.

[0180] The metal-clad foil laminate having an insulating layer comprising a cured resin composition according to this embodiment is a metal-clad foil laminate having an insulating layer with low dielectric properties, high thermal conductivity, and low moisture absorption, which is not easily affected by changes in the external environment such as moisture. Furthermore, it also has good formability.

[0181] [Wiring board]

[0182] 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.

[0183] like Figure 3 As shown, the wiring board 21 according to this embodiment includes: Figure 1The insulating layer 12 used after curing the prepreg 1 shown; and the wiring 14 formed by laminating the insulating layer 12 together and removing a portion of the metal foil 13. That is, the wiring board 21 includes: an insulating layer 12 comprising a cured resin composition; and wiring 14 disposed on the insulating layer 12. Furthermore, the insulating layer 12 may be formed from the cured resin composition or from the cured prepreg.

[0184] 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 such, examples include etching the metal foil 13 on the surface of the metal foil laminate 11 manufactured as described above to form wiring, thereby creating a wiring board 21 with wiring forming a circuit on the surface of the insulating layer 12. In other words, the wiring board 21 can be obtained by removing a portion of the metal foil 13 from the surface of the metal foil laminate 11, thereby forming a circuit. Furthermore, as a method for forming a circuit, in addition to the methods described above, methods such as forming a circuit using a semi-additive process (SAP) or a modified semi-additive process (MSAP) can be listed. The wiring board 21 has an insulating layer 12 with low dielectric properties and high heat resistance, and the low dielectric properties are well maintained even after water absorption treatment.

[0185] This wiring board is an insulating board with low dielectric properties, high thermal conductivity, and is not easily affected by changes in the external environment such as moisture (low moisture absorption rate).

[0186] [Resin-coated metal foil]

[0187] Figure 4 This is a schematic cross-sectional view showing an example of the resin-coated metal foil 31 involved in this embodiment.

[0188] 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.

[0189] Furthermore, 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 resin layer containing 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 layer containing the 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.

[0190] Furthermore, the metal foil used in the metal foil-coated laminate can be used without restriction. Examples of metal foils include copper foil and aluminum foil.

[0191] The resin-coated metal foil 31 and the resin-coated film 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, polymethylpentene films, and films formed by applying a release agent layer to these films.

[0192] 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 blade coater. The coated resin composition is heated, for example, at a temperature of 80°C or higher and 180°C or lower, for a time of 1 minute 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.

[0193] A resin-bearing metal foil having a resin layer comprising the resin composition or a semi-cured product of the resin composition described in this embodiment is a resin-bearing metal foil that can be suitably obtained with a cured product that has low dielectric properties, high thermal conductivity, and is not easily affected by changes in the external environment such as moisture (low moisture absorption). Furthermore, it also has good formability.

[0194] [Resin-coated membrane]

[0195] Figure 5This is a schematic cross-sectional view showing an example of the resin-coated membrane 41 according to this embodiment.

[0196] 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.

[0197] Furthermore, the resin layer 42 may contain a semi-cured product 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 product 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 product of the resin composition. Furthermore, the resin composition or the semi-cured product 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.

[0198] Furthermore, the support film 43 can be any support film used in resin-impregnated films 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.

[0199] The resin-coated membrane 41 may be equipped with a covering film or the like as needed. The covering film helps prevent the introduction of foreign matter. The covering film is not particularly limited, and examples include polyolefin films, polyester films, and polymethylpentene films.

[0200] 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.

[0201] 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 blade coater. The coated resin composition is heated, for example, at a temperature of 80°C or higher and 180°C or lower, for a time of 1 minute 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.

[0202] A resin-containing film having a resin layer comprising the resin composition or a semi-cured product of the resin composition described in this embodiment is a resin-containing film with low dielectric properties, high thermal conductivity, and low moisture absorption, which is not easily affected by changes in the external environment such as moisture. Furthermore, it also exhibits good formability.

[0203] 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.

[0204] Example

[0205] [Examples 1-15 and Comparative Examples 1-6]

[0206] The components used in preparing the resin composition in this embodiment will be described.

[0207] (polyphenylene ether compound)

[0208] PPE1: A polyphenylene ether compound with a methacryloyl group at the end (a modified polyphenylene ether in which the terminal hydroxyl groups are modified with methacryloyl groups, represented by the above formula (15), and Y in formula (15) is a dimethylmethylene (represented by formula (12) and R in formula (12) 33 and R 34 (A modified polyphenylene ether compound with methyl groups, SA9000 manufactured by SABIC Innovative Plastics, with a weight-average molecular weight of Mw2000 and 2 terminal functional groups)

[0209] PPE2: A modified polyphenylene ether obtained by reacting polyphenylene ether with chloromethylstyrene. Specifically, it is a modified polyphenylene ether obtained by reacting polyphenylene ether with chloromethylstyrene.

[0210] First, 200g of polyphenylene ether (SA90 manufactured by SABIC Innovative Plastics Co., Ltd., with two terminal hydroxyl groups and a weight-average molecular weight of Mw 1700), 30g of a mixture of p-chloromethylstyrene and m-chloromethylstyrene in a 50:50 mass ratio (chloromethylstyrene: CMS manufactured by Tokyo Chemical Industry Co., Ltd.), 1.227g of tetrabutylammonium bromide as a phase transfer catalyst, and 400g of toluene were added to a 1-liter three-necked flask equipped with a temperature regulator, stirring device, cooling equipment, and dropping funnel, and stirred. Then, stirring continued until the polyphenylene ether, chloromethylstyrene, and tetrabutylammonium bromide dissolved in toluene. At this point, heating was gradually carried out until the liquid temperature reached 75°C. Then, an aqueous solution of sodium hydroxide (20g sodium hydroxide / 20g water), an alkali metal hydroxide, was added dropwise to the solution over 20 minutes. Subsequently, stirring was continued at 75°C for 4 hours. Next, the contents of the flask were neutralized with 10% hydrochloric acid by mass, and then a large amount of methanol was added. This caused a precipitate to form in the liquid inside the flask. In other words, the product contained in the reaction solution inside the flask was reprecipitated. Then, the precipitate was removed by filtration, washed three times with a methanol-water mixture at a mass ratio of 80:20, and dried at 80°C for 3 hours under reduced pressure.

[0211] use 1 The obtained solid was analyzed by 1H-NMR (400MHz, CDCl3, TMS). NMR measurements confirmed a peak originating from vinyl benzyl (ethylene benzyl) at 5–7 ppm. This confirmed that the obtained solid was a modified polyphenylene ether compound having vinyl benzyl (ethylene benzyl) as a substituent at the molecule's terminal. Specifically, the obtained solid was confirmed to be a vinyl benzylated polyphenylene ether. The obtained modified polyphenylene ether compound is represented by the above formula (14), where Y is dimethylmethylene (represented by formula (12) and R in formula (12) is... 33 and R 34 A modified polyphenylene ether compound consisting of a methyl group (Z being a phenylene group), R1 to R3 being hydrogen atoms, and n being 1.

[0212] In addition, the number of terminal functional groups of the modified polyphenylene ether was determined in the following manner.

[0213] First, the modified polyphenylene ether was accurately weighed. This weight is set as X (mg). Then, the weighed modified polyphenylene ether was dissolved in 25 mL of dichloromethane. 100 μL of a 10% by mass tetraethylammonium hydroxide (TEAH) ethanol solution (TEAH:ethanol (volume ratio) = 15:85) was added to this solution, and the absorbance (Abs) at 318 nm was measured using a UV spectrophotometer (Shimadzu Corporation UV-1600). Based on this measurement result, the number of terminal hydroxyl groups of the modified polyphenylene ether was calculated using the following formula.

[0214] Residual OH content (μmol / g) = [(25×Abs) / (ε×OPL×X)]×10 6

[0215] Here, ε represents the absorptivity, which is 4700 L / mol·cm. Furthermore, OPL is the unit optical path length, which is 1 cm.

[0216] Furthermore, the calculated residual OH content (number of terminal hydroxyl groups) of the modified polyphenylene ether is almost zero, indicating that almost all the hydroxyl groups in the unmodified polyphenylene ether have been modified. Therefore, the reduction in the number of terminal hydroxyl groups compared to the unmodified polyphenylene ether is equal to the number of terminal hydroxyl groups in the unmodified polyphenylene ether. In other words, the number of terminal functional groups is 2.

[0217] In addition, the intrinsic viscosity (IV) of the modified polyphenylene ether in dichloromethane at 25°C was determined. Specifically, the intrinsic viscosity (IV) of the modified polyphenylene ether in a 0.18 g / 45 ml solution of dichloromethane (at 25°C) was determined using a viscometer (ALS500 Visco System, Schott AG). The result was an intrinsic viscosity (IV) of 0.086 dl / g.

[0218] Furthermore, the molecular weight distribution of the modified polyphenylene ether was determined using GPC. The weight-average molecular weight (Mw) was then calculated based on this molecular weight distribution. The result was that Mw was 2300.

[0219] (Curing agent)

[0220] TAIC: Triallyl isocyanurate (TAIC manufactured by Nippon Chemical Co., Ltd.)

[0221] DVB: Divinylbenzene (manufactured by Nippon Steel & Sumitomo Metal Corporation)

[0222] (Reaction initiator)

[0223] Peroxide initiator: PBP (1,3-bis(butylperoxyisopropyl)benzene; PERBUTYL P manufactured by Nippon Oil Co., Ltd.)

[0224] (Styrene-based polymers)

[0225] SIBSTAR073T: Styrene-isobutylene-styrene triblock copolymer (manufactured by Kaneka Corporation, number average molecular weight 66,000, molar fraction of styrene: 30%)

[0226] SIBSTAR103T: Styrene-isobutylene-styrene triblock copolymer (manufactured by Kaneka Corporation, number average molecular weight 85,000, styrene molar fraction: 30%)

[0227] SIBSTAR102T: Styrene-isobutylene-styrene triblock copolymer (manufactured by Kaneka Corporation, number average molecular weight 84,000, styrene molar fraction: 30%)

[0228] H1041: Hydrogenated styrene-based thermoplastic elastomer (SEBS) (Manufactured by Asahi Kasei Corporation, "Tuftee (registered trademark) H1041", number average molecular weight 54,000, molar fraction of styrene: 30%)

[0229] P2000: Hydrogenated styrene-based thermoplastic elastomer (SEBS) (Manufactured by Asahi Kasei Corporation, "Tuftec (registered trademark) P2000", number average molecular weight 40,000, molar fraction of styrene: 67%)

[0230] (Inorganic filler)

[0231] Boron nitride 1: "AP-10S" manufactured by MARUKA Co., Ltd., with a volume average particle size of 3.0 μm.

[0232] Boron nitride 2: "AP-20S" manufactured by MARUKA Co., Ltd., with a volume average particle size of 2.0 μm.

[0233] Boron nitride 3: "SGP" manufactured by Denka Co., Ltd., with a volume average particle size of 18 μm.

[0234] Silica: "FB-7SDC" manufactured by Denka Co., Ltd., with a volume average particle size of 5μm.

[0235] Alumina: "DAW-03AC" manufactured by Denka Co., Ltd., with a volume average particle size of 8 μm.

[0236] Silicon nitride: "SSN-β1" manufactured by Shinano Electric Smelting Co., Ltd., with a volume average particle size of 1 μm.

[0237] Synthetic magnesite: Anhydrous magnesium carbonate particles (MAGTHERMO MS-L manufactured by Kamishima Chemical Industry Co., Ltd., with a volume average particle size of 8 μm)

[0238] (Preparation method)

[0239] First, all components except the inorganic filler were added to toluene according to the compositions (parts by mass) listed in Tables 1-3 and mixed. The mixture was stirred for 60 minutes. Then, filler (parts by mass) was added to the resulting liquid to adjust the amount of toluene added so that the solid component concentration of the dispersed resin composition was 65 parts by mass, and the mixture was stirred for 60 minutes to perform a primary dispersion of the filler. Then, the inorganic filler was further dispersed using a bead mill to obtain a varnish-like resin composition (varnish).

[0240] Next, an evaluation substrate (cured prepreg) 1 was obtained as follows.

[0241] The obtained varnish was impregnated into a fibrous substrate (glass cloth: Asahi Kasei Corporation #1078 type, L glass), and then dried at 120°C for 3 minutes to produce a prepreg. Each prepreg was then cut into 200mm squares, and copper foil (Furukawa Electric Corporation "FV-WS", copper foil thickness: 35μm) was laminated to both sides of boards obtained by overlapping one, two, and four sheets. The boards were then heated to 200°C at a rate of 4°C / min, and subjected to heating and pressurization at 200°C for 120 minutes and 3MPa pressure to produce copper-clad laminates of three different thicknesses (evaluation substrate 1).

[0242] In addition, as the evaluation substrate (cured prepreg) 2, the evaluation substrate 2 was manufactured in the same manner as the evaluation substrate 1, except that the pressure during heating and pressurization was set to 4 MPa, by using four overlapping plates of prepreg cut into 200 mm squares as described above.

[0243] It should be noted that, regarding the formability evaluation described later, both a plate from which the copper foil was removed from the copper-clad laminate of the four overlapping prepreg sheets of the evaluation substrate 1 and a plate from which the copper foil was removed from the copper-clad laminate of the evaluation substrate 2 were used. Furthermore, in the thermal conductivity measurement described later, a cured product of one prepreg sheet of the evaluation substrate and a plate from which the copper foil was removed from the copper-clad laminate of the two overlapping prepreg sheets (cured prepreg) were used. In the dielectric properties (relative permittivity) and moisture absorption evaluation tests, a plate from which the copper foil was removed from the copper-clad laminate of the four overlapping prepreg sheets of the evaluation substrate (cured prepreg) was used. It should be noted that, regarding the substrates used in the evaluation tests of thermal conductivity, dielectric properties (relative permittivity), and moisture absorption, evaluation substrate 2 was used in Examples 17, 19, 20, and Comparative Example 6, while evaluation substrate 1 was used in the other examples and comparative examples. However, in Comparative Example 4, since all the evaluation substrates had poor formability, it was impossible to evaluate thermal conductivity, dielectric properties (relative permittivity), and moisture absorption.

[0244] The evaluation substrate (cured prepreg) prepared as described above was evaluated using the method shown below.

[0245] [Dielectric properties (dielectric loss factor)]

[0246] The dielectric loss factor (Df) of the evaluation substrate (cured prepreg) at 10 GHz was determined using the resonant cavity perturbation method. Specifically, the dielectric loss factor of the evaluation substrate at 10 GHz was determined using a network analyzer (Keysight Teehnologies N5230A). The acceptance criterion in this embodiment was Df ≤ 0.0032.

[0247] Moisture absorption rate

[0248] Three 50mm square evaluation substrates were prepared from the cured material obtained through molding. The moisture absorption rate before and after treatment was measured in a high-accelerated life testing apparatus set at 121°C and 100% humidity. Specifically, using a PCT bath (PC-242HSR2 manufactured by Hirayama Corporation), the weight of the samples (evaluation substrates: cured prepreg) before and after treatment was measured, and the moisture absorption rate was calculated based on the average of the three samples. In this embodiment, the acceptance criterion was a moisture absorption rate ≤0.4%.

[0249] [Formability]

[0250] Evaluation substrates 1 and 2, manufactured as described above, were examined in cross-section using a scanning electron microscope (S-3000N manufactured by Hitachi High Technology Co., Ltd.) to confirm the presence or absence of voids or scratches. Regarding the evaluation criteria, substrates without voids or scratches were rated as good (O), while those with voids or scratches were rated as unacceptable (×).

[0251] Thermal conductivity

[0252] The thermal conductivity of the obtained evaluation substrate (cured prepreg) was determined according to the method of ASTM D5470. Specifically, the thermal conductivity of the obtained evaluation substrate (cured prepreg) was determined using a thermal property evaluation device (T3SterDynTIMTester manufactured by Mentor Graphics). In this embodiment, the acceptance criterion for thermal conductivity is ≥1.0 W / m·K.

[0253] The results of the above evaluations are shown in Tables 1 to 3.

[0254]

[0255]

[0256]

[0257] (Inspection)

[0258] As can be seen from Tables 1 and 2, it has been confirmed that the examples using the resin composition of the present invention can all provide a cured product with low dielectric properties, high thermal conductivity and low moisture absorption, and also have moldability.

[0259] On the other hand, as shown in Table 3, the moisture absorption rate increased in Comparative Examples 1 and 2, which used hydrogenated styrene-based thermoplastic elastomer (SEBS) instead of the styrene-based polymer of the present invention. Furthermore, in Comparative Example 3, which did not contain the styrene-based polymer, both the moisture absorption rate and thermal conductivity decreased. It was also found that adequate formability could not be obtained in Comparative Example 4, which had an excessive total content of inorganic fillers. In addition, adequate thermal conductivity could not be obtained in Comparative Examples 5-6, which did not contain boron nitride as an inorganic filler, and in Comparative Example 7, which contained boron nitride but had a low total content of inorganic fillers.

[0260] This application is based on Japanese Patent Application No. 2020-122559, filed on July 17, 2020, the contents of which are included in this application.

[0261] To illustrate the present invention, it has been appropriately and sufficiently described above with reference to specific embodiments and accompanying drawings. However, it should be recognized that those skilled in the art can readily make changes and / or modifications to the above embodiments. Therefore, any modified or improved embodiments implemented by those skilled in the art that do not depart from the scope of protection of the claims can be interpreted as being included within the scope of protection of the claims.

[0262] Industrial availability

[0263] This invention has broad industrial applicability in the technical field of electronic materials and various devices using the materials.

Claims

1. A resin composition, characterized in that... contain: A polyphenylene ether compound having at least one of the groups shown in formula (1) and formula (2); A curing agent capable of reacting with the polyphenylene ether compound; Styrene-based polymers having the structural units shown in formulas (3) and (4) below; as well as Inorganic fillers containing boron nitride, wherein, The styrene-based polymer comprises a styrene-isobutylene-styrene block copolymer. The content of the inorganic filler is 100-320 parts by weight relative to a total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer. The boron nitride has an average particle size of 0.5–20 μm. The inorganic filler comprises silicon dioxide and boron nitride, and the content ratio of silicon dioxide to boron nitride in the inorganic filler, i.e., silicon dioxide:boron nitride by mass, is 80-20:20-80. In formula (1), s represents an integer from 0 to 10, Z represents an aryl group, and R1 to R3 each independently represent a hydrogen atom or an alkyl group. In formula (2), R4 represents a hydrogen atom or an alkyl group. In equation (3), R 35 ~R 37 Each independently represents a hydrogen atom or an alkyl group, R 38 Indicates hydrogen atom or alkyl group, In equation (4), R 39 ~R 42 Each independently represents a hydrogen atom or an alkyl group, in R 39 and R 40 When each is an alkyl group, R 41 and R 42 It is a hydrogen atom, or in R 41 and R 42 When each is an alkyl group, R 39 and R 40 It is a hydrogen atom.

2. The resin composition according to claim 1, characterized in that, The curing agent comprises at least one selected from the group consisting of a polyfunctional acrylate compound having two or more acryloyl groups in the molecule, a polyfunctional methacrylate compound having two or more methacryloyl groups in the molecule, a polyfunctional vinyl compound having two or more vinyl groups in the molecule, a styrene derivative, an allyl compound having an allyl group in the molecule, a maleimide compound having a maleimide group in the molecule, an acenaphthene compound having an acenaphthene structure in the molecule, and an isocyanurate compound having an isocyanurate group in the molecule.

3. The resin composition according to claim 1 or 2, characterized in that, The inorganic filler further comprises at least one selected from the group consisting of anhydrous magnesium carbonate, aluminum oxide, and silicon nitride.

4. The resin composition according to claim 1 or 2, characterized in that, The polyphenylene ether compound has the groups shown in formula (2).

5. The resin composition according to claim 1 or 2, characterized in that, The content of the styrene-based polymer is 5 to 25 parts by mass relative to a total of 100 parts by mass of the polyphenylene ether compound, the curing agent, and the styrene-based polymer.

6. The resin composition according to claim 1 or 2, characterized in that, The content of the polyphenylene ether compound is 50 to 90 parts by weight relative to a total of 100 parts by weight of the polyphenylene ether compound, the curing agent, and the styrene-based polymer.

7. The resin composition according to claim 1 or 2, characterized in that, In the styrene polymer, the molar fraction of the structural unit represented by formula (3) is 5 to 50 moles.

8. The resin composition according to claim 1 or 2, characterized in that, The weight-average molecular weight of the styrene-based polymer is 10,000 to 200,000.

9. The resin composition according to claim 1 or 2, characterized in that, The cured resin composition has a thermal conductivity of 1.0 W / m·K or higher and a dielectric loss factor of 0.003 or lower at a frequency of 10 GHz.

10. 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 9; as well as Fiber-based substrate.

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

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

13. 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 9 or a cured product of the prepreg according to claim 10; as well as Metal foil.

14. 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 9 or a cured product of the prepreg according to claim 10; as well as wiring.

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