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

Abstract

One aspect of the present invention provides a resin composition which contains: at least one of (A) a polyphenylene ether compound that has at least one of a group represented by formula (1) and a group represented by formula (2) in each molecule, and (B) a maleimide compound; and (C) ceramic particles that contain (C1) aluminum titanate particles. In formula (1), p represents a number from 0 to 10; Ar represents an arylene group; and each of R1 to R3 independently represents a hydrogen atom or an alkyl group. In formula (2), R4 represents a hydrogen atom or an alkyl group.

Description

[Technical Field]

[0001] The present invention relates to a resin composition, a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board. [Background technology]

[0002] Wiring boards used in electronic devices, for example, when used as wiring boards for antennas, are required to be compatible with high frequencies. Substrate materials for forming insulating layers in such high-frequency wiring boards are required to have a low dielectric loss tangent in order to reduce loss during signal transmission. Furthermore, in order to miniaturize the wiring board, they are also required to have a high relative dielectric constant. Examples of such substrate materials include resin compositions containing fillers with a high relative dielectric constant.

[0003] Examples of resin compositions containing such high-dielectric-constant fillers include the resin composition described in Patent Document 1. Patent Document 1 describes a resin composition in which a predetermined amount of high-dielectric-constant inorganic insulating filler having a predetermined particle size is blended into a mixed resin obtained by mixing a styrene-terminated thermosetting polyphenylene ether having a predetermined molecular weight and a styrene-based elastomer in a predetermined ratio. Patent Document 1 discloses that a prepreg obtained by adhering the resin composition to glass cloth or glass nonwoven fabric has a high dielectric constant and a low dielectric loss tangent. Patent Document 1 also discloses that this prepreg can be molded into a laminate without voids or smears, and is suitable for use as a substrate material for electronic devices because of its excellent workability, safety, and environmental friendliness during manufacturing.

[0004] It is believed that a resin composition capable of producing a cured product with a high dielectric constant can be obtained by adding a filler with a high dielectric constant, such as strontium titanate, which is used as the high dielectric constant inorganic insulating filler in Patent Document 1. However, even if the dielectric constant can be increased by adding a filler with a high dielectric constant, there are cases in which the dielectric loss tangent also increases. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2010 / 147083 Summary of the Invention

[0006] The present invention has been made in view of the above circumstances, and aims to provide a resin composition that can give a cured product having a high relative dielectric constant and a low dielectric loss tangent. Another aim of the present invention is to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that can be obtained using the resin composition.

[0007] One aspect of the present invention is a resin composition comprising at least one of a polyphenylene ether compound (A) having in the molecule at least one of a group represented by the following formula (1) and a group represented by the following formula (2), and a maleimide compound (B), and ceramic particles (C) including aluminum titanate particles (C1).

[0008] [ka] In formula (1), p represents 0 to 10, Ar represents an arylene group, and R1 to R3 each independently represent a hydrogen atom or an alkyl group.

[0009] [ka] In formula (2), R4 represents a hydrogen atom or an alkyl group. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. [Figure 3] FIG. 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. [Figure 4] FIG. 4 is a schematic cross-sectional view showing an example of a resin-coated metal foil according to an embodiment of the present invention. [Figure 5] FIG. 5 is a schematic cross-sectional view showing an example of a resin-coated film according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] In order to increase the dielectric constant of a cured resin composition, it is considered to include a filler with a high dielectric constant, as described above. Furthermore, in order to further increase the dielectric constant of a cured resin composition, it is also considered to increase the content of the filler with a high dielectric constant in the resin composition. However, according to the studies of the present inventors, simply adding a filler with a high dielectric constant may increase the dielectric constant, but the dielectric loss tangent may also increase, depending on the resin components and filler composition contained in the resin composition, as described above. In such cases, it is considered that simply increasing the content of the filler with a high dielectric constant in the resin composition may further increase the dielectric constant, but the dielectric loss tangent may also increase. Furthermore, excessive increase in the content of the filler with a high dielectric constant may result in a decrease in performance other than dielectric properties such as the dielectric constant and dielectric loss tangent. Therefore, after various studies, the present inventors have found that not only the resin components contained in the resin composition but also the type and composition of the filler affect the dielectric properties such as the dielectric constant and dielectric loss tangent of the cured product. As a result of various investigations, including an investigation into this influence, the present inventors have found that the above object can be achieved by the present invention described below.

[0012] Hereinafter, embodiments of the present invention will be described, but the present invention is not limited to these.

[0013] [Resin composition] A resin composition according to one embodiment of the present invention is a resin composition containing at least one of a polyphenylene ether compound (A) having in its molecule at least one of a group represented by the following formula (1) and a group represented by the following formula (2), and a maleimide compound (B), and ceramic particles (C) containing aluminum titanate particles (C1). The resin composition may contain either the polyphenylene ether compound (A) or the maleimide compound (B), or may contain both. When a resin composition having such a configuration is cured, a cured product having a high relative dielectric constant and a low dielectric loss tangent is obtained.

[0014] It is believed that by curing one of the polyphenylene ether compound (A) and the maleimide compound (B) contained in the resin composition, a cured product with a low dielectric loss tangent can be obtained. It is believed that this cured product will have a low dielectric loss tangent as well as a low dielectric constant. It is believed that by including the ceramic particles (C) in the resin composition, the dielectric constant of the cured product can be increased. Since the ceramic particles (C) contain the aluminum titanate particles (C1), their inclusion in the resin composition is believed to increase the dielectric constant while suppressing an increase in the dielectric loss tangent of the cured product. For these reasons, it is believed that by curing the resin composition, a cured product with a high dielectric constant and a low dielectric loss tangent can be obtained.

[0015] Furthermore, as wiring boards become thinner, semiconductor packages equipped with semiconductor chips on wiring boards tend to warp, resulting in mounting defects. To suppress warpage in semiconductor packages equipped with semiconductor chips on wiring boards, the insulating layer is required to have a low thermal expansion coefficient. Therefore, substrate materials for forming the insulating layer of wiring boards are required to yield cured products with a low thermal expansion coefficient. For this reason, substrate materials for wiring boards and the like are required to have a high relative dielectric constant and a low dielectric dissipation factor, as described above, in order to support high frequencies, and are also required to have a low thermal expansion coefficient. Furthermore, since wiring boards are required to prevent even finer wiring from peeling from the insulating layer, high adhesion between the wiring and the insulating layer is even more required. Therefore, metal-clad laminates and resin-coated metal foils are required to have high adhesion between the metal foil and the insulating layer, and substrate materials for forming the insulating layer of wiring boards are required to yield cured products with excellent adhesion to the metal foil. In contrast, the resin composition according to this embodiment not only has a high relative dielectric constant and a low dielectric dissipation factor, but also yields cured products with a low thermal expansion coefficient and excellent adhesion to the metal foil.

[0016] (Polyphenylene ether (A)) The polyphenylene ether (A) is not particularly limited as long as it is a polyphenylene ether compound having at least one (substituent) of a group represented by the following formula (1) and a group represented by the following formula (2) in the molecule. Examples of the polyphenylene ether compound include polyphenylene ether compounds having at least one of a group represented by the following formula (1) and a group represented by the following formula (2) at the molecular terminal, such as modified polyphenylene ether compounds terminally modified with at least one of a group represented by the following formula (1) and a group represented by the following formula (2).

[0017] [ka] In formula (1), R1 to R3 are independent of each other. That is, R1 to R3 may be the same group or different groups. R1 to R3 represent a hydrogen atom or an alkyl group. Ar represents an arylene group. p represents 0 to 10. In addition, when p is 0 in formula (1), it means that Ar is directly bonded to the terminal of the polyphenylene ether.

[0018] The arylene group is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as a phenylene group and polycyclic aromatic groups such as a naphthalene ring. The arylene group also includes derivatives in which a hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0019] The alkyl group is not particularly limited, and is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0020] [ka] In formula (2), R4 represents a hydrogen atom or an alkyl group.

[0021] The alkyl group is not particularly limited, and is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0022] Examples of the group represented by formula (1) include a vinylbenzyl group (ethenylbenzyl group) represented by the following formula (3): Furthermore, examples of the group represented by formula (2) include an acryloyl group and a methacryloyl group.

[0023] [ka]

[0024] More specifically, examples of the substituent (at least one of the group represented by formula (1) and the group represented by formula (2)) include vinylbenzyl groups (ethenylbenzyl groups) such as o-ethenylbenzyl group, m-ethenylbenzyl group, and p-ethenylbenzyl group, vinylphenyl group, acryloyl group, and methacryloyl group. The polyphenylene ether compound may have one type of substituent, or two or more types. The polyphenylene ether compound may have, for example, any one of o-ethenylbenzyl group, m-ethenylbenzyl group, and p-ethenylbenzyl group, or may have two or three types thereof.

[0025] The polyphenylene ether compound has a polyphenylene ether chain in the molecule, and preferably has, for example, a repeating unit represented by the following formula (4) in the molecule.

[0026] [ka] In formula (4), t represents 1 to 50. R5 to R8 are each independent. That is, R5 to R8 may be the same group or different groups. R5 to R8 represent a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. Of these, a hydrogen atom and an alkyl group are preferred.

[0027] Specific examples of the functional groups listed for R5 to R8 include the following.

[0028] 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. Specific examples include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0029] The alkenyl group is not particularly limited, but is preferably an alkenyl group having 2 to 18 carbon atoms, and more preferably an alkenyl group having 2 to 10 carbon atoms. Specific examples include a vinyl group, an allyl group, and a 3-butenyl group.

[0030] The alkynyl group is not particularly limited, but is preferably an alkynyl group having 2 to 18 carbon atoms, and more preferably an alkynyl group having 2 to 10 carbon atoms. Specific examples include an ethynyl group and a prop-2-yn-1-yl group (propargyl group).

[0031] The alkylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkyl group, but for example, an alkylcarbonyl group having 2 to 18 carbon atoms is preferred, and an alkylcarbonyl group having 2 to 10 carbon atoms is more preferred. Specific examples include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a pivaloyl group, a hexanoyl group, an octanoyl group, and a cyclohexylcarbonyl group.

[0032] The alkenylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkenyl group, but for example, an alkenylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkenylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specific examples include an acryloyl group, a methacryloyl group, and a crotonoyl group.

[0033] The alkynylcarbonyl group is not particularly limited as long as it is a carbonyl group substituted with an alkynyl group, but for example, an alkynylcarbonyl group having 3 to 18 carbon atoms is preferred, and an alkynylcarbonyl group having 3 to 10 carbon atoms is more preferred. Specific examples include a propioloyl group.

[0034] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polyphenylene ether compound are not particularly limited, and are preferably 500 to 5,000, more preferably 800 to 4,000, and even more preferably 1,000 to 3,000. The weight-average molecular weight and number-average molecular weight may be measured by a common molecular weight measurement method, specifically, values ​​measured using gel permeation chromatography (GPC) may be used. Furthermore, when the polyphenylene ether compound has a repeating unit represented by formula (4) in the molecule, t is preferably a value such that the weight-average molecular weight and number-average molecular weight of the polyphenylene ether compound fall within the above ranges. Specifically, t is preferably 1 to 50.

[0035] When the weight-average molecular weight and number-average molecular weight of the polyphenylene ether compound are within the above ranges, the compound has the excellent low dielectric properties of polyphenylene ether, and the cured product not only has excellent heat resistance but also has excellent moldability. This is believed to be due to the following reasons. When the weight-average molecular weight and number-average molecular weight are within the above ranges, ordinary polyphenylene ethers have a relatively low molecular weight, which tends to reduce heat resistance. In this regard, the polyphenylene ether compound according to the present embodiment has one or more unsaturated double bonds at its terminals, and therefore, as the curing reaction progresses, it is believed that a cured product with sufficiently high heat resistance can be obtained. Furthermore, when the weight-average molecular weight and number-average molecular weight of the polyphenylene ether compound are within the above ranges, it is believed that the compound has a relatively low molecular weight and therefore has excellent moldability. Therefore, it is believed that such polyphenylene ether compounds not only have excellent heat resistance but also excellent moldability can be obtained as a cured product.

[0036] The average number of the substituents (number of terminal functional groups) at the molecular terminals per 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. On the other hand, if the number of terminal functional groups is too large, the reactivity becomes too high, which may cause problems such as reduced shelf life and reduced fluidity of the resin composition. That is, when such a polyphenylene ether compound is used, insufficient fluidity may cause molding defects such as the generation of voids during multilayer molding, which may lead to moldability problems such as difficulty in obtaining a highly reliable printed wiring board.

[0037] The number of terminal functional groups in a polyphenylene ether compound may be, for example, a numerical value representing the average number of the substituents per molecule of all polyphenylene ether compounds present in 1 mole of the polyphenylene ether compound. The number of terminal functional groups can be measured, for example, by measuring the number of hydroxyl groups remaining in the resulting polyphenylene ether compound and calculating the difference from the number of hydroxyl groups in the polyphenylene ether before the substituents are introduced (before modification). This difference from the number of hydroxyl groups in the polyphenylene ether before modification is the number of terminal functional groups. The number of hydroxyl groups remaining in the polyphenylene ether compound can be measured by adding a quaternary ammonium salt (tetraethylammonium hydroxide) that associates with hydroxyl groups to a solution of the polyphenylene ether compound and measuring the UV absorbance of the resulting mixed solution.

[0038] The intrinsic viscosity of the polyphenylene ether compound is not particularly limited. Specifically, it is preferably 0.03 to 0.12 dL / g, more preferably 0.04 to 0.11 dL / g, and even more preferably 0.06 to 0.095 dL / g. If the intrinsic viscosity is too low, the molecular weight tends to be low, and it tends to be difficult to achieve low dielectric properties such as a low dielectric loss tangent. On the other hand, if the intrinsic viscosity is too high, the viscosity tends to be high, sufficient fluidity cannot be achieved, and the moldability of the cured product tends to be reduced. Therefore, if the intrinsic viscosity of the polyphenylene ether compound is within the above range, excellent heat resistance and moldability of the cured product can be achieved.

[0039] The intrinsic viscosity here is the intrinsic viscosity measured in methylene chloride at 25°C, and more specifically, for example, is the value measured using a viscometer for a 0.18 g / 45 ml methylene chloride solution (liquid temperature: 25°C). Examples of such a viscometer include the AVS500 Visco System manufactured by Schott.

[0040] Examples of the polyphenylene ether compound include a polyphenylene ether compound represented by the following formula (5) and a polyphenylene ether compound represented by the following formula (6). As the polyphenylene ether compound, these polyphenylene ether compounds may be used alone, or these two types of polyphenylene ether compounds may be used in combination.

[0041] [ka]

[0042] [ka]

[0043] In formula (5) and formula (6), R9 to R 16 and R 17 ~R 24 are independent of each other. That is, R9 to R 16 and R17 ~R 24 may be the same group or different groups. 16 and R 17 ~R 24 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. X1 and X2 are each independent. That is, X1 and X2 may be the same group or different groups. X1 and X2 represent a substituent having a carbon-carbon unsaturated double bond. A and B represent repeating units represented by the following formula (7) and formula (8), respectively. In addition, in formula (6), Y represents a linear, branched, or cyclic hydrocarbon having 20 or less carbon atoms.

[0044] [ka]

[0045] [ka]

[0046] In the formulas (7) and (8), m and n each represent an integer of 0 to 20. 25 ~R 28 and R 29 ~R 32 are independent of each other. That is, R 25 ~R 28 and R 29 ~R 32 may be the same group or different groups. 25 ~R 28 and R 29 ~R 32 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group.

[0047] The polyphenylene ether compound represented by the formula (5) and the polyphenylene ether compound represented by the formula (6) are not particularly limited as long as they satisfy the above-mentioned constitution. Specifically, in the formulas (5) and (6), R9 to R 16 and R 17 ~R 24 As mentioned above, R9 to R 16 and R 17 ~R 24 may be the same group or different groups. 16 and R 17 ~R 24 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group, among which a hydrogen atom and an alkyl group are preferred.

[0048] In the formulas (7) and (8), m and n each preferably represent a value of 0 to 20, as described above. Furthermore, it is preferable that m and n represent a numerical value such that the sum of m and n is 1 to 30. Therefore, it is more preferable that m represents a numerical value of 0 to 20, n represents a numerical value of 0 to 20, and the sum of m and n represents a numerical value of 1 to 30. Furthermore, R 25 ~R 28 and R 29 ~R 32 are independent of each other. That is, R 25 ~R 28 and R 29 ~R 32 may be the same group or different groups. 25 ~R 28 and R 29 ~R 32 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group, among which a hydrogen atom and an alkyl group are preferred.

[0049] R9~R 32 are the same as R5 to R8 in the above formula (4).

[0050] In the formula (6), Y is, as described above, a linear, branched, or cyclic hydrocarbon having 20 or less carbon atoms. Examples of Y include a group represented by the following formula (9).

[0051] [ka] In the formula (9), R 33 and R 34 are each independently a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group. Examples of the group represented by formula (9) include a methylene group, a methylmethylene group, and a dimethylmethylene group, and among these, a dimethylmethylene group is preferred.

[0052] In the formula (5) and the formula (6), X1 and X2 each independently represent a substituent having a carbon-carbon double bond. In the polyphenylene ether compound represented by the formula (5) and the polyphenylene ether compound represented by the formula (6), X1 and X2 may be the same group or different groups.

[0053] More specific examples of the polyphenylene ether compound represented by the formula (5) include polyphenylene ether compounds represented by the following formula (10).

[0054] [ka]

[0055] More specific examples of the polyphenylene ether compound represented by the formula (6) include a polyphenylene ether compound represented by the following formula (11) and a polyphenylene ether compound represented by the following formula (12).

[0056] [ka]

[0057] [ka]

[0058] In the above formulas (10) to (12), m and n are the same as m and n in the above formulas (7) and (8). In addition, in the above formulas (10) and (11), R1 to R3, p, and Ar are the same as R1 to R3, p, and Ar in the above formula (1). In addition, in the above formulas (11) and (12), Y is the same as Y in the above formula (6). In addition, in the above formula (12), R4 is the same as R4 in the above formula (2).

[0059] The method for synthesizing the polyphenylene ether compound used in the present embodiment is not particularly limited as long as it is possible to synthesize a polyphenylene ether compound having the above-mentioned substituent in the molecule. Specific examples of this method include a method of reacting polyphenylene ether with a compound in which the above-mentioned substituent and a halogen atom are bonded.

[0060] Examples of the compound in which a substituent and a halogen atom are bonded include compounds in which a halogen atom is bonded to a substituent represented by any of the formulas (1) to (3). Specific examples of the halogen atom include a chlorine atom, a bromine atom, an iodine atom, and a fluorine atom, with a chlorine atom being preferred. More specific examples of the compound in which a halogen atom is bonded to a substituent having a carbon-carbon unsaturated double bond include o-chloromethylstyrene, p-chloromethylstyrene, and m-chloromethylstyrene. The compound in which a halogen atom is bonded to a substituent having a carbon-carbon unsaturated double bond may be used alone or in combination of two or more. For example, o-chloromethylstyrene, p-chloromethylstyrene, and m-chloromethylstyrene may be used alone or in combination of two or more.

[0061] The polyphenylene ether used as the raw material is not particularly limited as long as it can ultimately synthesize a predetermined polyphenylene ether compound. Specific examples include polyphenylene ethers composed of 2,6-dimethylphenol and at least one of a bifunctional phenol and a trifunctional phenol, and those containing polyphenylene ether as the main component, such as poly(2,6-dimethyl-1,4-phenylene oxide). Furthermore, a bifunctional phenol is a phenolic compound having two phenolic hydroxyl groups per molecule, such as tetramethylbisphenol A. Furthermore, a trifunctional phenol is a phenolic compound having three phenolic hydroxyl groups per molecule.

[0062] The polyphenylene ether compound can be synthesized by the method described above. Specifically, the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded are dissolved in a solvent and stirred. By doing so, the polyphenylene ether reacts with the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, thereby obtaining the polyphenylene ether compound used in this embodiment.

[0063] The reaction is preferably carried out in the presence of an alkali metal hydroxide. It is believed that this allows the reaction to proceed smoothly. This is believed to be because the alkali metal hydroxide functions as a dehydrohalogenating agent, specifically, a dehydrochlorinating agent. That is, it is believed that the alkali metal hydroxide eliminates hydrogen halide from the phenol group of the polyphenylene ether and the compound in which the substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and as a result, the substituent having a carbon-carbon unsaturated double bond is bonded to the oxygen atom of the phenol group in place of the hydrogen atom of the phenol group of the polyphenylene ether.

[0064] The alkali metal hydroxide is not particularly limited as long as it can act as a dehalogenating agent, and examples thereof include sodium hydroxide, etc. The alkali metal hydroxide is usually used in the form of an aqueous solution, specifically, an aqueous sodium hydroxide solution.

[0065] The reaction conditions, such as reaction time and reaction temperature, vary depending on the compound in which the substituent having a carbon-carbon unsaturated double bond is bonded to a halogen atom, and are not particularly limited as long as the reaction proceeds favorably. Specifically, the reaction temperature is preferably room temperature to 100°C, more preferably 30 to 100°C. The reaction time is preferably 0.5 to 20 hours, more preferably 0.5 to 10 hours.

[0066] The solvent used in the reaction is not particularly limited as long as it can dissolve the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded, and does not inhibit the reaction between the polyphenylene ether and the compound in which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded. Specific examples include toluene.

[0067] The above reaction is preferably carried out in the presence of not only an alkali metal hydroxide but also a phase transfer catalyst. That is, the above reaction is preferably carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst. Doing so is believed to allow the reaction to proceed more smoothly. This is believed to be due to the following: A phase transfer catalyst has the function of incorporating an alkali metal hydroxide, is soluble in both a polar solvent phase such as water and a nonpolar solvent phase such as an organic solvent, and is capable of transferring between these phases. Specifically, when an aqueous solution of sodium hydroxide 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 solution of sodium hydroxide is added dropwise to the solvent being used for the reaction, the solvent and the aqueous solution of sodium hydroxide separate, and it is believed that the sodium hydroxide is unlikely to migrate to the solvent. In this case, it is believed that the aqueous solution of sodium hydroxide added as the alkali metal hydroxide is unlikely to contribute to promoting the reaction. On the other hand, when the reaction is carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst, the alkali metal hydroxide is transferred to the solvent while being incorporated into the phase transfer catalyst, and the aqueous sodium hydroxide solution is thought to contribute more to promoting the reaction. Therefore, when the reaction is carried out in the presence of an alkali metal hydroxide and a phase transfer catalyst, the reaction is thought to proceed more smoothly.

[0068] The phase transfer catalyst is not particularly limited, but examples thereof include quaternary ammonium salts such as tetra-n-butylammonium bromide.

[0069] The resin composition used in the present embodiment preferably contains the polyphenylene ether compound obtained as described above as the polyphenylene ether compound.

[0070] (Maleimide compound (B)) The maleimide compound (B) is not particularly limited as long as it is a compound having a maleimide group in the molecule. Examples of the maleimide compound (B) include monofunctional maleimide compounds having one maleimide group in the molecule, polyfunctional maleimide compounds having two or more maleimide groups in the molecule, and modified maleimide compounds. Examples of the modified maleimide compounds include modified maleimide compounds in which a portion of the molecule is modified with an amine compound, modified maleimide compounds in which a portion of the molecule is modified with a silicone compound, and modified maleimide compounds in which a portion of the molecule is modified with an amine compound and a silicone compound. The maleimide compound (B) preferably has a maleimide functional group equivalent of 100 to 2000 g / eq., more preferably 150 to 500 g / eq. The maleimide compound (B) preferably has a molecular weight of 300 to 4000, more preferably 450 to 1000. When the maleimide compound is a polymer such as an oligomer, the molecular weight is a number average molecular weight.

[0071] The maleimide compound (B) preferably includes, for example, at least one of a maleimide compound (B1) having a phenylmaleimide group in the molecule and a maleimide compound (B2) having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule. As the maleimide compound (B), either one of them may be used alone, or these two may be used in combination. Furthermore, the maleimide compound (B) may be a maleimide compound other than the maleimide compound (B1) having a phenylmaleimide group in the molecule and the maleimide compound (B2) having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule.

[0072] (Maleimide compound (B1) having a phenylmaleimide group in the molecule) The maleimide compound (B1) having a phenylmaleimide group in the molecule is not particularly limited as long as it is a maleimide compound having a phenylmaleimide group in the molecule, and examples thereof include maleimide compounds having a phenylmaleimide group and an aliphatic hydrocarbon group having 10 or less carbon atoms in the molecule.

[0073] Examples of the maleimide compound (B1) having a phenylmaleimide group in the molecule include 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, bisphenol A diphenyl ether bismaleimide, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, biphenylaralkyl maleimide resins, and maleimide compounds having a phenylmaleimide group and an arylene structure substituted at the meta position in the molecule.

[0074] Commercially available products can be used as such maleimide compounds. Specifically, 4,4'-diphenylmethane bismaleimide can be, for example, BMI-1000 manufactured by Daiwa Chemical Industry Co., Ltd. Furthermore, polyphenylmethane maleimide can be, for example, BMI-2300 manufactured by Daiwa Chemical Industry Co., Ltd. Furthermore, m-phenylene bismaleimide can be, for example, BMI-3000 manufactured by Daiwa Chemical Industry Co., Ltd. Furthermore, bisphenol A diphenyl ether bismaleimide can be, for example, BMI-4000 manufactured by Daiwa Chemical Industry Co., Ltd. Furthermore, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide can be, for example, BMI-5100 manufactured by Daiwa Chemical Industry Co., Ltd. Furthermore, 4-methyl-1,3-phenylene bismaleimide can be, for example, BMI-7000 manufactured by Daiwa Chemical Industry Co., Ltd. As the 1,6'-bismaleimide-(2,2,4-trimethyl)hexane, for example, BMI-TMH manufactured by Daiwa Chemical Industry Co., Ltd. can be used. As the biphenylaralkyl maleimide resin, for example, MIR-3000 manufactured by Nippon Kayaku Co., Ltd. can be used. As the maleimide compound having a phenylmaleimide group and an arylene structure substituted at the meta position in the molecule, for example, the maleimide compound represented by the following formula (13) can be used, and for example, MIR-5000 manufactured by Nippon Kayaku Co., Ltd. can be used.

[0075] [ka] In the formula (13), s represents 1 to 5.

[0076] Furthermore, examples of the maleimide compound (B1) having a phenylmaleimide group in the molecule include maleimide compounds having a phenylmaleimide group and an indane structure in the molecule. More specific examples of such maleimide compounds include maleimide compounds represented by the following formula (14), and even more specific examples include maleimide compounds represented by the following formula (14) in which Ra represents a methyl group, q represents 2, and r represents 0.

[0077] [ka] In formula (14), each Ra is independent. That is, each Ra may be the same group or different groups. For example, when q is 2 to 4, 2 to 4 Ra bonded to the same benzene ring may be the same group or different groups. Ra represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. Each Rb independently represents an alkyl group having 1 to 10 carbon atoms, an alkyloxy group having 1 to 10 carbon atoms, an alkylthio group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aryloxy group having 6 to 10 carbon atoms, an arylthio group having 6 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, a halogen atom, a nitro group, a hydroxyl group, or a mercapto group. q represents 0 to 4. r represents 0 to 3. a represents 0.95 to 10.

[0078] (Maleimide Compound (B2) Having an Aliphatic Hydrocarbon Group with 11 or More Carbons in the Molecule) The maleimide compound (B2) having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule is not particularly limited as long as it is a maleimide compound having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule, and examples thereof include compounds having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule but not having a phenylmaleimide group in the molecule. The aliphatic hydrocarbon group is not particularly limited as long as it has 11 or more carbon atoms, and preferably has 20 or more carbon atoms, and more preferably has 30 or more carbon atoms. Such an aliphatic hydrocarbon group may be linear, may have a branched structure in the group, or may have an alicyclic structure in the group.

[0079] Examples of the maleimide compound (B2) having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule include maleimide compounds represented by the following formulas (15) to (18). Commercially available maleimide compounds can be used as such maleimide compounds. Specifically, the maleimide compound represented by the following formula (15) can be, for example, BMI-1500 manufactured by Desingner Molercules Inc. The maleimide compound represented by the following formula (16) can be, for example, BMI-1700 manufactured by Desingner Molercules Inc. The maleimide compound represented by the following formula (17) can be, for example, BMI-689 manufactured by Desingner Molercules Inc. The maleimide compound represented by the following formula (18) can be, for example, BMI-3000 manufactured by Desingner Molercules Inc.

[0080] [ka] In the formula (15), x, which is a repeating unit, represents 1 to 10.

[0081] [ka] In the formula (16), y, which is a repeating unit, represents 1 to 10.

[0082] [ka]

[0083] [ka] In the formula (18), z, which is a repeating unit, represents 1 to 10.

[0084] The maleimide compound (B2) having an aliphatic hydrocarbon group having 11 or more carbon atoms in the molecule preferably has a weight-average molecular weight (Mw) of 500 to 4000. With such a molecular weight, the dielectric loss tangent is lower, and the melt viscosity of the resulting resin composition is lower, resulting in better moldability. The weight-average molecular weight may be measured by a general molecular weight measurement method, and specific examples include values ​​measured using gel permeation chromatography (GPC).

[0085] The maleimide compounds (B) may be used alone or in combination of two or more.

[0086] (Ceramic particles (C)) The ceramic particles (C) are not particularly limited as long as they are ceramic particles containing aluminum titanate particles (C1). That is, the ceramic particles (C) may be ceramic particles containing the aluminum titanate particles (C1) and ceramic particles (C2) other than the aluminum titanate particles (C1), or may be ceramic particles made of the aluminum titanate particles (C1).

[0087] The aluminum titanate particles (C1) are not particularly limited, and examples thereof include aluminum titanate particles obtained by common synthesis methods such as a precipitation method, a solid phase method, and an electrofusion method.

[0088] The average particle size of the aluminum titanate particles (C1) is not particularly limited, but is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm. When the aluminum titanate particles (C1) have such a particle size, the dielectric constant of the cured product of the obtained resin composition can be further increased while further suppressing an increase in the dielectric tangent. Here, the average particle size is the volume-average particle size, and examples thereof include the volume-based cumulative 50% diameter (D50). Specific examples thereof include the particle size (D50) at which the cumulative particle size distribution from the small particle diameter side reaches 50% (volume-based) in a particle size distribution measured by a general laser diffraction / scattering method (the volume-based cumulative 50% diameter in laser diffraction / scattering particle size distribution measurement).

[0089] The specific gravity of the aluminum titanate particles (C1) is not particularly limited, but is, for example, 3 to 4 g / cm 3 It is preferable that:

[0090] The ceramic particles (C2) other than the aluminum titanate particles (C1) are not particularly limited. Examples of the ceramic particles (C2) include strontium titanate particles, calcium titanate particles, barium titanate particles, magnesium titanate particles, zinc titanate particles, lanthanum titanate particles, neodymium titanate particles, titanium dioxide particles, aluminum oxide particles, and silica particles. Among these, strontium titanate particles, calcium titanate particles, barium titanate particles, magnesium titanate particles, titanium dioxide particles, aluminum oxide particles, and silica particles are preferred, and strontium titanate particles, calcium titanate particles, titanium dioxide particles, and aluminum oxide particles are more preferred. Using these in combination with the aluminum titanate particles (C1) can further increase the dielectric constant of the cured product of the resulting resin composition. The ceramic particles (C2) may be used alone or in combination of two or more types.

[0091] The average particle size of the ceramic particles (C2) is not particularly limited. The average particle size of the ceramic particles (C2) varies depending on the type of the ceramic particles (C2), but is preferably 0.1 to 10 μm, and more preferably 0.3 to 5 μm. The average particle size is the volume-average particle size as described above, and examples thereof include the cumulative 50% diameter (D50) on a volume basis in laser diffraction / scattering particle size distribution measurement. The specific gravity of the ceramic particles (C2) is not particularly limited. The specific gravity of the ceramic particles (C2) varies depending on the type of the ceramic particles (C2), but is preferably 3 to 7 g / cm. 3 It is preferable that:

[0092] The ceramic particles (C) may be surface-treated or untreated. The ceramic particles (C) may be, for example, a combination of the surface-treated aluminum titanate particles (C1) and the untreated ceramic particles (C2), or a combination of the untreated aluminum titanate particles (C1) and the surface-treated ceramic particles (C2). Examples of the surface treatment include treatment with a coupling agent such as a silane coupling agent or a titanium coupling agent. The coupling agent may be added to the ceramic particles (C) as a surface-treated coupling agent, or may be added to the resin composition.

[0093] Examples of the silane coupling agent and the titanium coupling agent include coupling agents having at least one functional group selected from the group consisting of a vinyl group, a styryl group, a methacryloyl group, an acryloyl group, a phenylamino group, an isocyanurate group, a ureido group, a mercapto group, an isocyanate group, an epoxy group, and an acid anhydride group. That is, the silane coupling agent and the titanium coupling agent include compounds having at least one reactive functional group selected from the group consisting of a vinyl group, a styryl group, a methacryloyl group, an acryloyl group, a phenylamino group, an isocyanurate group, a ureido group, a mercapto group, an isocyanate group, an epoxy group, and an acid anhydride group, and further having a hydrolyzable group such as a methoxy group or an ethoxy group.

[0094] Examples of the silane coupling agent include those having a vinyl group, such as vinyltriethoxysilane and vinyltrimethoxysilane. Examples of the silane coupling agent include those having a styryl group, such as p-styryltrimethoxysilane and p-styryltriethoxysilane. Examples of the silane coupling agent include those having a methacryloyl group, such as 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropylethyldiethoxysilane. Examples of the silane coupling agent include those having an acryloyl group, such as 3-acryloxypropyltrimethoxysilane and 3-acryloxypropyltriethoxysilane. Examples of the silane coupling agent include those having a phenylamino group, such as N-phenyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltriethoxysilane. Examples of the titanium coupling agent include isopropyl(N-ethylaminoethylamino)titanate, isopropyltriisostearoyltitanate, titanium di(dioctylpyrophosphate)oxyacetate, tetraisopropyldi(dioctylphosphite)titanate, and neoalkoxytri(pN-(β-aminoethyl)aminophenyl)titanate. These coupling agents may be used alone or in combination of two or more.

[0095] (Content) The content of the ceramic particles (C) is preferably 100 to 250 parts by mass, more preferably 100 to 200 parts by mass, per 100 parts by mass of the total of the polyphenylene ether compound (A) and the maleimide compound (B). That is, the total content of the polyphenylene ether compound (A) and the maleimide compound (B) is preferably 40 to 100 parts by mass, more preferably 40 to 80 parts by mass, per 100 parts by mass of the ceramic particles (C). Note that, when only one of the polyphenylene ether compound (A) and the maleimide compound (B) is contained, the total of the polyphenylene ether compound (A) and the maleimide compound (B) refers to the content of the compound that contains the polyphenylene ether compound (A). For example, in the case of a resin composition that contains the polyphenylene ether compound (A) but does not contain the maleimide compound (B), the total of the polyphenylene ether compound (A) and the maleimide compound (B) refers to the content of the polyphenylene ether compound (A). If the content of the ceramic particles (C) is too low, the effects of the ceramic particles (C) become insufficient, and for example, the heat resistance and flame retardancy tend not to be sufficiently improved. If the content of the ceramic particles (C) is too high, the melt viscosity of the obtained resin composition tends to be too high, and the moldability tends to be reduced. Therefore, if the content of the ceramic particles (C) is within the above range, the obtained resin composition and the cured product of the prepreg can be suitably obtained as a cured product having a high relative dielectric constant and a low dielectric loss tangent.

[0096] The content of the aluminum titanate particles (C1) is preferably 5 to 100 parts by mass, more preferably 5 to 90 parts by mass, even more preferably 10 to 90 parts by weight, and particularly preferably 20 to 90 parts by weight, per 100 parts by mass of the ceramic particles (C). If the content of the aluminum titanate particles (C1) is too low, the effect of the aluminum titanate particles (C1) becomes insufficient. That is, if the content of the aluminum titanate particles (C1) is reduced, the content of the ceramic particles (C2) other than the aluminum titanate particles (C1) increases. Although the dielectric constant of the cured resin composition can be increased, the dielectric loss tangent also tends to increase. Therefore, if the content of the aluminum titanate particles (C1) is within the above range, a cured resin composition having a higher dielectric constant and a lower dielectric loss tangent can be obtained.

[0097] (Other ingredients) The resin composition may contain, as necessary, components other than the polyphenylene ether compound (A), the maleimide compound (B), and the ceramic particles (C) (other components) within a range that does not impair the effects of the present invention. Examples of other components contained in the resin composition according to this embodiment may further include additives such as a curing agent, a reaction initiator, a reaction accelerator, a catalyst, a polymerization retarder, a polymerization inhibitor, a dispersant, a leveling agent, a coupling agent, an antifoaming agent, an antioxidant, a heat stabilizer, an antistatic agent, an ultraviolet absorber, a dye or pigment, and a lubricant.

[0098] The resin composition according to this embodiment may optionally contain a curing agent that reacts with the polyphenylene ether compound (A) to contribute to curing of the resin composition, provided that the effects of the present invention are not impaired. Furthermore, the resin composition according to this embodiment may optionally contain a curing agent that reacts with the maleimide compound (B) to contribute to curing of the resin composition, provided that the effects of the present invention are not impaired. Examples of the curing agent include epoxy compounds, methacrylate compounds, acrylate compounds, cyanate ester compounds, active ester compounds, benzoxazine compounds, and allyl compounds.

[0099] The epoxy compound is a compound having an epoxy group in the molecule, and specific examples thereof include bisphenol-type epoxy compounds such as bisphenol A-type epoxy compounds, phenol novolac-type epoxy compounds, cresol novolac-type epoxy compounds, dicyclopentadiene-type epoxy compounds, bisphenol A novolac-type epoxy compounds, biphenyl aralkyl-type epoxy compounds, and naphthalene ring-containing epoxy compounds. The epoxy compound also includes epoxy resins, which are polymers of the above epoxy compounds.

[0100] The methacrylate compound is a compound having a methacryloyl group in the molecule, and examples thereof include monofunctional methacrylate compounds having one methacryloyl group in the molecule and polyfunctional methacrylate compounds having two or more methacryloyl groups in the molecule. Examples of the monofunctional methacrylate compound include methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. Examples of the polyfunctional methacrylate compound include dimethacrylate compounds such as tricyclodecane dimethanol dimethacrylate (DCP).

[0101] The acrylate compound is a compound having an acryloyl group in the molecule, and examples thereof include monofunctional acrylate compounds having one acryloyl group in the molecule and polyfunctional acrylate compounds having two or more acryloyl groups in the molecule. Examples of the monofunctional acrylate compound include methyl acrylate, ethyl acrylate, propyl acrylate, and butyl acrylate. Examples of the polyfunctional acrylate compound include diacrylate compounds such as tricyclodecane dimethanol diacrylate.

[0102] The cyanate ester compound is a compound having a cyanate group in the molecule, and examples thereof include 2,2-bis(4-cyanatephenyl)propane, bis(3,5-dimethyl-4-cyanatephenyl)methane, and 2,2-bis(4-cyanatephenyl)ethane.

[0103] The active ester compound is a compound having an ester group with high reactivity in the molecule, and examples thereof include benzenecarboxylic acid active ester, benzenedicarboxylic acid active ester, benzenetricarboxylic acid active ester, benzenetetracarboxylic acid active ester, naphthalenecarboxylic acid active ester, naphthalenedicarboxylic acid active ester, naphthalenetricarboxylic acid active ester, naphthalenetetracarboxylic acid active ester, fluorenecarboxylic acid active ester, fluorenedicarboxylic acid active ester, fluorenetricarboxylic acid active ester, and fluorenetetracarboxylic acid active ester.

[0104] The benzoxazine compound is a compound having a benzoxazine ring in the molecule, and examples thereof include benzoxazine resins.

[0105] The allyl compound is a compound having an allyl group in the molecule, and examples thereof include triallyl isocyanurate compounds such as triallyl isocyanurate (TAIC), diallyl bisphenol compounds, and diallyl phthalate (DAP).

[0106] The curing agent may be used alone or in combination of two or more kinds.

[0107] The weight-average molecular weight of the curing agent is not particularly limited, but is preferably 100 to 5000, more preferably 100 to 4000, and even more preferably 100 to 3000. If the weight-average molecular weight of the curing agent is too low, the curing agent may be more likely to volatilize from the resin composition's blending components. If the weight-average molecular weight of the curing agent is too high, the viscosity of the resin composition varnish or the melt viscosity during heat molding may be too high. Therefore, when the weight-average molecular weight of the curing agent is within this range, a resin composition with excellent heat resistance of the cured product can be obtained. This is thought to be because the resin composition can be cured appropriately. Note that the weight-average molecular weight may be measured using a general molecular weight measurement method, specifically, a value measured using gel permeation chromatography (GPC), etc.

[0108] The curing agent has an average number of functional groups per molecule that contribute to the reaction during curing of the resin composition (number of functional groups), which varies depending on the weight-average molecular weight of the curing agent, but is preferably, for example, 1 to 20, and more preferably 2 to 18. If the number of functional groups is too small, it tends to be difficult to obtain sufficient heat resistance of the cured product. On the other hand, if the number of functional groups is too large, the reactivity becomes too high, which may cause problems such as reduced storage stability and reduced fluidity of the resin composition.

[0109] As described above, the resin composition according to this embodiment may contain a reaction initiator. The curing reaction can proceed even if the resin composition does not contain a reaction initiator. However, depending on the process conditions, it may be difficult to raise the temperature high enough for curing to proceed, so a reaction initiator may be added. The reaction initiator is not particularly limited as long as it can accelerate the curing reaction of the resin composition, and examples thereof include peroxides and organic azo compounds. Examples of peroxides include dicumyl peroxide, α,α'-bis(t-butylperoxy-m-isopropyl)benzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, and benzoyl peroxide. Examples of organic azo compounds include azobisisobutyronitrile. Furthermore, if necessary, a metal carboxylate or the like can be used in combination. This can further accelerate the curing reaction. Among these, α,α'-bis(t-butylperoxy-m-isopropyl)benzene is preferably used. Because α,α'-bis(t-butylperoxy-m-isopropyl)benzene has a relatively high reaction initiation temperature, it can suppress the acceleration of the curing reaction when curing is not necessary, such as during prepreg drying, and can suppress a decrease in the shelf life of the resin composition. Furthermore, because α,α'-bis(t-butylperoxy-m-isopropyl)benzene has low volatility, it does not volatilize during prepreg drying or storage, and therefore has good stability. Furthermore, the reaction initiators may be used alone or in combination of two or more.

[0110] As described above, the resin composition according to this embodiment may contain a coupling agent. The coupling agent may be contained in the resin composition, or may be contained as a coupling agent pre-surface-treated on the ceramic particles (C) contained in the resin composition. Among these, the coupling agent is preferably contained as a coupling agent pre-surface-treated on the ceramic particles (C). It is more preferable to contain the coupling agent pre-surface-treated on the ceramic particles (C) in this manner, and further to contain a coupling agent in the resin composition. In addition, in the case of a prepreg, the prepreg may contain the coupling agent pre-surface-treated on a fibrous substrate. Examples of the coupling agent include the same coupling agents as those used in the surface treatment of the ceramic particles (C) described above.

[0111] As described above, the resin composition according to this embodiment may contain a flame retardant. The inclusion of a flame retardant can enhance the flame retardancy of the cured resin composition. The flame retardant is not particularly limited. Specifically, in fields where halogen-based flame retardants such as bromine-based flame retardants are used, preferred examples include ethylene dipentabromobenzene, ethylene bistetrabromoimide, decabromodiphenyl oxide, tetradecabromodiphenoxybenzene, and bromostyrene-based compounds that react with the polymerizable compounds, all of which have melting points of 300°C or higher. The use of a halogen-based flame retardant is believed to suppress halogen elimination at high temperatures and thus prevent a decrease in heat resistance. Furthermore, in fields requiring halogen-free materials, phosphorus-containing flame retardants (phosphorus-based flame retardants) are sometimes used. Examples of the phosphorus-based flame retardant include, but are not limited to, phosphate ester-based flame retardants, phosphazene-based flame retardants, bisdiphenylphosphine oxide-based flame retardants, and phosphinate-based flame retardants. A specific example of a phosphate ester-based flame retardant is a condensed phosphate ester of dixylenyl phosphate. A specific example of a phosphazene-based flame retardant is phenoxyphosphazene. A specific example of a bisdiphenylphosphine oxide-based flame retardant is xylylenebisdiphenylphosphine oxide. A specific example of a phosphinate-based flame retardant is, for example, a metal phosphinate salt of an aluminum dialkylphosphinate. As the flame retardant, each of the exemplified flame retardants may be used alone or in combination of two or more.

[0112] (Application) The resin composition is used to produce a prepreg, as described below, and also to form a resin layer provided in a resin-coated metal foil and a resin-coated film, and an insulating layer provided in a metal-clad laminate and a wiring board.

[0113] The cured product of the resin composition preferably has a dielectric constant of 4 or more, more preferably 5 or more, at a frequency of 10 GHz. The cured product of the resin composition preferably has a dielectric loss tangent of 0.0055 or less, more preferably 0.005 or less, at a frequency of 10 GHz. The dielectric constant and dielectric loss tangent here refer to the dielectric constant and dielectric loss tangent of the cured product of the resin composition at a frequency of 10 GHz, and examples thereof include the dielectric constant and dielectric loss tangent of the cured product of the resin composition at a frequency of 10 GHz measured by a cavity resonator perturbation method. The resin composition thus produces a cured product with a high dielectric constant and a low dielectric loss tangent. Therefore, the resin composition is suitable for forming insulating layers provided on high-frequency wiring boards, such as wiring boards for antennas and antenna substrates for millimeter-wave radar. In other words, the resin composition is suitable for producing high-frequency wiring boards.

[0114] The high frequency compatible wiring board is not particularly limited, but examples thereof include wiring boards with a small inter-wire distance, wiring boards with a small wire width, and multi-layer wiring boards.

[0115] The minimum value of the inter-wiring distance is not particularly limited, but is preferably 50 μm or less, and more preferably 30 μm or less. That is, the resin composition is suitable for use in manufacturing wiring boards with such small inter-wiring distances. Even when the minimum inter-wiring distance is 50 μm or less, high-speed signal transmission can be achieved, and signal transmission loss can be reduced. By producing a wiring board with such a minimum inter-wiring distance of 50 μm or less, i.e., a substrate having wiring with at least a portion where the inter-wiring distance is 50 μm or less, the wiring density within the substrate can be increased, and for example, the wiring board can be made smaller. Here, the inter-wiring distance refers to the distance between adjacent wirings.

[0116] The minimum value of the wiring width is not particularly limited, but is preferably 50 μm or less, and more preferably 30 μm or less. That is, the resin composition is suitable for use in manufacturing wiring boards with such small wiring widths. Even when the minimum wiring width is 50 μm or less, high-speed signal transmission can be achieved, and signal transmission loss can be reduced. By producing a wiring board with such a minimum wiring width of 50 μm or less, i.e., a substrate having wiring that includes at least a portion with a wiring width of 50 μm or less, the wiring density within the substrate can be increased, and for example, the wiring board can be made smaller. Here, the wiring width is the distance perpendicular to the longitudinal direction of the wiring.

[0117] The wiring board may be a multilayer wiring board having two or more circuit layers, and the resin composition according to this embodiment can be suitably used as an interlayer insulating material for the multilayer wiring board. The wiring board is not particularly limited, but may be, for example, a multilayer wiring board having two or more circuit layers, with a wiring pattern having at least a portion of the wiring distance of 50 μm or less. The resin composition according to this embodiment is not particularly limited, but is preferably used as an insulating material for the insulating layer of a highly multilayer wiring board having five or more circuit layers, or even ten or more circuit layers. This allows for higher wiring density in the multilayer wiring board, and even in such a multilayer wiring board, it is possible to achieve high-speed signal transmission and reduce loss during signal transmission. The wiring board can achieve high-speed signal transmission and reduce loss during signal transmission, whether the multilayer wiring board has conductive through holes, conductive vias, or both.

[0118] The cured product of the resin composition preferably has a coefficient of thermal expansion of 14 ppm / °C or less, more preferably 13 ppm / °C or less. Furthermore, the strength (copper foil peel strength) when peeling off a metal foil (copper foil) attached to the surface of a metal-clad laminate including the cured product of the resin composition is preferably 0.45 N / mm or more, more preferably 0.5 N / mm or more. The resin composition according to this embodiment not only has a high relative dielectric constant and a low dielectric dissipation factor, but also provides a cured product having a low coefficient of thermal expansion and excellent adhesion to metal foil.

[0119] (Manufacturing method) The method for producing the resin composition is not particularly limited as long as it can produce the resin composition, and examples thereof include a method of mixing at least one of the polyphenylene ether compound (A) and the maleimide compound (B), and the ceramic particles (C) to a predetermined content, etc. In addition, when a varnish-like composition containing an organic solvent is obtained, the method described below, etc. can be used.

[0120] Furthermore, by using the resin composition according to this embodiment, a prepreg, a metal-clad laminate, a wiring board, a resin-coated metal foil, and a resin-coated film can be obtained as follows.

[0121] [Prepreg] FIG. 1 is a schematic cross-sectional view showing an example of a prepreg 1 according to an embodiment of the present invention.

[0122] 1, the prepreg 1 according to this embodiment comprises the resin composition or a semi-cured product of the resin composition 2, and a fibrous base material 3. This prepreg 1 comprises the resin composition or a semi-cured product of the resin composition 2, and the fibrous base material 3 present in the resin composition or the semi-cured product of the resin composition 2.

[0123] In this embodiment, the semi-cured product refers to a resin composition that has been partially cured to the extent that it can be further cured. That is, the semi-cured product refers to a resin composition that has been semi-cured (B-staged). For example, when a resin composition is heated, the viscosity initially gradually decreases, and then curing begins, and the viscosity gradually increases. In such a case, the semi-cured state can be exemplified by the state between when the viscosity starts to increase and when the composition is completely cured.

[0124] The prepreg obtained using the resin composition according to this embodiment may comprise a semi-cured product of the resin composition as described above, or may comprise the uncured resin composition itself. That is, it may be a prepreg comprising a semi-cured product of the resin composition (the resin composition in B stage) and a fibrous base material, or a prepreg comprising the resin composition before curing (the resin composition in A stage) and a fibrous base material. Furthermore, the resin composition or the semi-cured product of the resin composition may be obtained by drying or heat-drying the resin composition.

[0125] When producing the prepreg, the resin composition 2 is often prepared in a varnish form and used to impregnate the fibrous base material 3, which is the base material for forming the prepreg. That is, the resin composition 2 is usually often a resin varnish prepared in a varnish form. Such a varnish-like resin composition (resin varnish) is prepared, for example, as follows.

[0126] First, each component that is soluble in an organic solvent is added to the organic solvent and dissolved. Heating may be performed if necessary. Subsequently, components that are insoluble in the organic solvent are added as needed, and the mixture is dispersed using a ball mill, bead mill, planetary mixer, roll mill, or the like until a predetermined dispersion state is achieved, thereby preparing a varnish-like resin composition. The organic solvent used here is not particularly limited, as long as it dissolves the polyphenylene ether compound (A), the maleimide compound (B), and the like and does not inhibit the curing reaction. Specific examples include toluene and methyl ethyl ketone (MEK).

[0127] Specific examples of the fibrous substrate include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. Glass cloth can be used to obtain a laminate with excellent mechanical strength, and flattened glass cloth is particularly preferred. A specific example of the flattening process is a method in which glass cloth is continuously pressed with a press roll at an appropriate pressure to compress the yarns flat. The thickness of commonly used fibrous substrates is, for example, 0.01 mm or more and 0.3 mm or less. The glass fibers constituting the glass cloth are not particularly limited, and examples include Q glass, NE glass, E glass, S glass, T glass, L glass, and L2 glass. The surface of the fibrous substrate may be treated with a silane coupling agent. The silane coupling agent is not particularly limited, but examples thereof include silane coupling agents having at least one group selected from the group consisting of a vinyl group, an acryloyl group, a methacryloyl group, a styryl group, an amino group, and an epoxy group in the molecule.

[0128] The method for producing the prepreg is not particularly limited as long as it can produce the prepreg. Specifically, when producing the prepreg, the resin composition according to the present embodiment is often prepared in the form of a varnish, as described above, and used as a resin varnish.

[0129] Specific examples of methods for producing the prepreg 1 include a method in which the resin composition 2, for example, a resin composition 2 prepared in a varnish form, is impregnated into a fibrous substrate 3, followed by drying. The resin composition 2 is impregnated into the fibrous substrate 3 by immersion, coating, or the like. Impregnation can be repeated multiple times as necessary. In this case, by repeating the impregnation using multiple resin compositions with different compositions and concentrations, it is possible to adjust the final composition and impregnation amount to the desired one.

[0130] The fibrous substrate 3 impregnated with the resin composition (resin varnish) 2 is heated under desired conditions, for example, at 40°C to 180°C for 1 minute to 10 minutes. By heating, a prepreg 1 in an uncured (A-stage) or semi-cured (B-stage) state is obtained. The heating also volatilizes the organic solvent from the resin varnish, reducing or eliminating the organic solvent.

[0131] The resin composition according to this embodiment is a resin composition that can yield a cured product having a high dielectric constant and a low dielectric dissipation factor. Therefore, a prepreg including this resin composition or a semi-cured product of this resin composition can yield a cured product having a high dielectric constant and a low dielectric dissipation factor. This prepreg can be used to suitably manufacture a wiring board having an insulating layer including a cured product having a high dielectric constant and a low dielectric dissipation factor. Furthermore, a cured product obtained from the resin composition not only has a high dielectric constant and a low dielectric dissipation factor, but also a low thermal expansion coefficient and excellent adhesion to metal foil. This allows the cured product of the prepreg to have a low thermal expansion coefficient and excellent adhesion to metal foil. Specifically, the cured product of the prepreg preferably has a dielectric constant of 4 or more, more preferably 5 or more, at a frequency of 10 GHz. Furthermore, the cured product of the prepreg preferably has a dielectric dissipation factor of 0.0055 or less, more preferably 0.005 or less, at a frequency of 10 GHz. The dielectric constant and dielectric loss tangent here refer to the dielectric constant and dielectric loss tangent of the cured prepreg at a frequency of 10 GHz. Examples include the dielectric constant and dielectric loss tangent of the cured prepreg at a frequency of 10 GHz measured by a cavity resonator perturbation method. The cured prepreg preferably has a thermal expansion coefficient of 14 ppm / °C or less, more preferably 13 ppm / °C or less. The cured prepreg preferably has a strength (copper foil peel strength) of 0.45 N / mm or more, more preferably 0.5 N / mm or more, when peeling off the metal foil (copper foil) attached to its surface in a metal-clad laminate comprising the cured prepreg. Therefore, a wiring board obtained from this prepreg not only has a high dielectric constant and a low dielectric loss tangent, but also has a low thermal expansion coefficient and an insulating layer with excellent adhesion to the metal foil.

[0132] [Metal-clad laminate] FIG. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate 11 according to an embodiment of the present invention.

[0133] As shown in FIG. 2, the metal-clad laminate 11 according to this embodiment includes an insulating layer 12 containing a cured product of the resin composition and a metal foil 13 disposed on the insulating layer 12. Examples of the metal-clad laminate 11 include a metal-clad laminate including an insulating layer 12 containing a cured product of the prepreg 1 shown in FIG. 1 and a metal foil 13 laminated together with the insulating layer 12. The insulating layer 12 may be formed from a cured product of the resin composition or a cured product of the prepreg. The thickness of the metal foil 13 varies depending on the performance required of the final wiring board and is not particularly limited. The thickness of the metal foil 13 can be appropriately set depending on the desired purpose and is preferably, for example, 0.2 to 70 μm. Examples of the metal foil 13 include copper foil and aluminum foil. When the metal foil is thin, it may be a carrier-supported copper foil having a release layer and a carrier to improve handling.

[0134] The method for producing the metal-clad laminate 11 is not particularly limited as long as it can produce the metal-clad laminate 11. Specifically, a method for producing the metal-clad laminate 11 using the prepreg 1 can be used. Examples of such a method include a method in which one or more prepregs 1 are stacked, and then a metal foil 13 such as copper foil is stacked on both or one of the upper and lower surfaces of the prepreg 1, and the metal foil 13 and the prepreg 1 are heated and pressurized to form an integrated laminate, thereby producing a double-sided or single-sided metal foil-clad laminate 11. That is, the metal-clad laminate 11 is obtained by stacking the metal foil 13 on the prepreg 1 and then heating and pressurizing the resulting laminate. The heating and pressurizing conditions can be appropriately set depending on the thickness of the metal-clad laminate 11, the type of resin composition contained in the prepreg 1, and other factors. For example, the temperature can be 170 to 230°C, the pressure can be 2 to 4 MPa, and the time can be 60 to 150 minutes. The metal-clad laminate may also be produced without using a prepreg. For example, a method may be used in which a varnish-like resin composition is applied onto a metal foil to form a layer containing the resin composition on the metal foil, followed by heating and pressurizing.

[0135] The resin composition according to this embodiment is a resin composition that can produce a cured product having a high dielectric constant and a low dielectric dissipation factor. Therefore, a metal-clad laminate having an insulating layer containing a cured product of this resin composition is a metal-clad laminate having an insulating layer containing a cured product having a high dielectric constant and a low dielectric dissipation factor. This metal-clad laminate can then be used to suitably produce a wiring board having an insulating layer containing a cured product having a high dielectric constant and a low dielectric dissipation factor. Furthermore, the cured product obtained from the resin composition not only has a high dielectric constant and a low dielectric dissipation factor, but also a low thermal expansion coefficient and excellent adhesion to metal foil. Therefore, a wiring board obtained using a metal-clad laminate having an insulating layer containing a cured product of the resin composition not only has a high dielectric constant and a low dielectric dissipation factor, but also has an insulating layer having a low thermal expansion coefficient and excellent adhesion to metal foil.

[0136] [Wiring board] FIG. 3 is a schematic cross-sectional view showing an example of wiring board 21 according to an embodiment of the present invention.

[0137] As shown in FIG. 3, wiring board 21 according to this embodiment includes insulating layer 12 containing a cured product of the resin composition and wiring 14 provided on insulating layer 12. Examples of wiring board 21 include a wiring board including insulating layer 12 formed by curing prepreg 1 shown in FIG. 1 and wiring 14 laminated together with insulating layer 12 and formed by partially removing metal foil 13. Insulating layer 12 may be formed from a cured product of the resin composition or a cured product of the prepreg. Furthermore, wiring board 21 is preferably a high-frequency compatible wiring board. Examples of high-frequency compatible wiring boards include wiring boards with a small inter-wire distance, a small inter-wire width, and a multilayer wiring board. Wiring boards with an inter-wire distance, inter-wire width, and number of layers within the aforementioned ranges are more preferred.

[0138] The method for producing the wiring board 21 is not particularly limited as long as it can produce the wiring board 21. Specifically, a method for producing the wiring board 21 using the prepreg 1 is exemplified. For example, the method includes a method for producing the wiring board 21 in which wiring is provided as a circuit on the surface of the insulating layer 12 by etching the metal foil 13 on the surface of the metal-clad laminate 11 produced as described above. That is, the wiring board 21 is obtained by forming a circuit by partially removing the metal foil 13 on the surface of the metal-clad laminate 11. In addition to the above methods, other methods for forming a circuit include, for example, circuit formation by a semi-additive process (SAP) or a modified semi-additive process (MSAP). The wiring board 21 is a wiring board having an insulating layer 12 containing a cured product having a high relative dielectric constant and a low dielectric loss tangent. Furthermore, the cured product obtained from the resin composition not only has a high dielectric constant and a low dielectric loss tangent, but also has a low thermal expansion coefficient and excellent adhesion to metal foil. As a result, the wiring board is provided with an insulating layer that not only has a high dielectric constant and a low dielectric loss tangent, but also has a low thermal expansion coefficient and excellent adhesion to metal foil.

[0139] As described above, the metal-clad laminate and the wiring board are provided with the insulating layer. The insulating layer (the insulating layer provided on the metal-clad laminate and the insulating layer provided on the wiring board) is preferably, specifically, the following insulating layer: The insulating layer preferably has a relative dielectric constant of 4 or more, more preferably 5 or more, at a frequency of 10 GHz. The insulating layer preferably has a dielectric loss tangent of 0.0055 or less, more preferably 0.005 or less, at a frequency of 10 GHz. The relative dielectric constant and dielectric loss tangent here refer to the relative dielectric constant and dielectric loss tangent of the insulating layer at a frequency of 10 GHz, and examples thereof include the relative dielectric constant and dielectric loss tangent of the insulating layer at a frequency of 10 GHz measured by a cavity resonator perturbation method. The insulating layer preferably has a thermal expansion coefficient of 14 ppm / °C or less, more preferably 13 ppm / °C or less. In the case of a metal-clad laminate, the insulating layer preferably has a strength (copper foil peel strength) of 0.45 N / mm or more, more preferably 0.5 N / mm or more when peeling off the metal foil (copper foil), and in the case of a wiring board, preferably has a strength (wiring peel strength) of 0.45 N / mm or more, more preferably 0.5 N / mm or more when peeling off the wiring.

[0140] [Metal foil with resin] FIG. 4 is a schematic cross-sectional view showing an example of a resin-coated metal foil 31 according to this embodiment.

[0141] 4, the resin-coated metal foil 31 according to this embodiment includes a resin layer 32 containing the resin composition or a semi-cured product of the resin composition, and a metal foil 13. The resin-coated metal foil 31 includes 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. The resin-coated metal foil 31 may also include another layer between the resin layer 32 and the metal foil 13.

[0142] The resin layer 32 may contain a semi-cured product of the resin composition as described above, or may contain the uncured resin composition. That is, the resin-coated metal foil 31 may comprise a resin layer containing a semi-cured product of the resin composition (the resin composition in B stage) and a metal foil, or a resin layer containing the resin composition before curing (the resin composition in A stage) and a metal foil. The resin layer may contain the resin composition or a semi-cured product of the resin composition, and may or may not contain a fibrous substrate. The resin composition or the semi-cured product of the resin composition may be obtained by drying or heat-drying the resin composition. The fibrous substrate may be the same as the fibrous substrate of a prepreg.

[0143] The metal foil may be any metal foil used in a metal-clad laminate or a resin-coated metal foil, and examples of the metal foil include copper foil and aluminum foil.

[0144] The resin-coated metal foil 31 may be provided with a cover film or the like as necessary. By providing a cover film, it is possible to prevent the inclusion of foreign matter, etc. The cover film is not particularly limited, but examples thereof include polyolefin film, polyester film, polymethylpentene film, and films formed by providing a release agent layer on these films.

[0145] The method for producing 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 producing the resin-coated metal foil 31 include a method of applying the varnish-like resin composition (resin varnish) onto the metal foil 13 and heating it. The varnish-like resin composition is applied onto the metal foil 13, for example, using a bar coater. The applied resin composition is heated, for example, at a temperature of 40°C to 180°C for 0.1 minutes to 10 minutes. The heated resin composition is formed on the metal foil 13 as an uncured resin layer 32. Note that the heating volatilizes the organic solvent from the resin varnish, thereby reducing or removing the organic solvent.

[0146] The resin composition according to this embodiment is a resin composition that can yield a cured product having a high dielectric constant and a low dielectric dissipation factor. Therefore, a resin-coated metal foil having a resin layer containing this resin composition or a semi-cured product of this resin composition is a resin-coated metal foil having a resin layer that can yield a cured product having a high dielectric constant and a low dielectric dissipation factor. This resin-coated metal foil can be used to produce a wiring board having an insulating layer containing a cured product having a high dielectric constant and a low dielectric dissipation factor. For example, by laminating the resin-coated metal foil on a wiring board, a multilayer wiring board can be produced. A wiring board obtained using such a resin-coated metal foil can be obtained that has an insulating layer containing a cured product having a high dielectric constant and a low dielectric dissipation factor. Furthermore, a cured product obtained from the resin composition not only has a high dielectric constant and a low dielectric dissipation factor, but also a low thermal expansion coefficient and excellent adhesion to metal foil. For this reason, a wiring board obtained using a resin-coated metal foil having a resin layer containing the resin composition or a semi-cured product of the resin composition not only has a high relative dielectric constant and a low dielectric tangent, but also has an insulating layer with a low thermal expansion coefficient and excellent adhesion to the metal foil.

[0147] [Resin-coated film] FIG. 5 is a schematic cross-sectional view showing an example of a resin-coated film 41 according to the present embodiment.

[0148] 5, the resin-coated film 41 according to this embodiment includes a resin layer 42 containing the resin composition or a semi-cured product of the resin composition, and a support film 43. The resin-coated film 41 includes the resin layer 42 and the support film 43 laminated together with the resin layer 42. The resin-coated film 41 may also include another layer between the resin layer 42 and the support film 43.

[0149] The resin layer 42 may contain a semi-cured product of the resin composition as described above, or may contain the uncured resin composition. That is, the resin-coated film 41 may include a resin layer containing a semi-cured product of the resin composition (the resin composition in B stage) and a support film, or may be a resin-coated film including a resin layer containing the resin composition before curing (the resin composition in A stage) and a support film. The resin layer may contain the resin composition or a semi-cured product of the resin composition, and may or may not contain a fibrous substrate. The resin composition or the semi-cured product of the resin composition may be obtained by drying or heat-drying the resin composition. The fibrous substrate may be the same as the fibrous substrate of a prepreg.

[0150] Any support film used for a resin-coated film can be used without limitation as the support film 43. Examples of the support film include electrically insulating films such as polyester film, polyethylene terephthalate (PET) film, polyimide film, polyparabanic acid film, polyether ether ketone film, polyphenylene sulfide film, polyamide film, polycarbonate film, and polyarylate film.

[0151] The resin-coated film 41 may be provided with a cover film or the like as needed. By providing a cover film, it is possible to prevent the inclusion of foreign matter, etc. The cover film is not particularly limited, but examples thereof include a polyolefin film, a polyester film, and a polymethylpentene film.

[0152] The support film and the cover film may be subjected to surface treatment such as matte treatment, corona treatment, release treatment, and roughening treatment, if necessary.

[0153] The method for producing the resin-coated film 41 is not particularly limited as long as it can produce the resin-coated film 41. Examples of methods for producing the resin-coated film 41 include a method in which the varnish-like resin composition (resin varnish) is applied to a support film 43 and heated. The varnish-like resin composition is applied to the support film 43 using, for example, a bar coater. The applied resin composition is heated, for example, at a temperature of 40°C to 180°C for 0.1 minutes to 10 minutes. The heated resin composition is formed on the support film 43 as an uncured resin layer 42. The heating volatilizes the organic solvent from the resin varnish, thereby reducing or removing the organic solvent.

[0154] The resin composition according to this embodiment is a resin composition that can yield a cured product having a high dielectric constant and a low dielectric dissipation factor. Therefore, a resin-attached film having a resin layer containing this resin composition or a semi-cured product of this resin composition is a resin-attached film having a resin layer that can yield a cured product having a high dielectric constant and a low dielectric dissipation factor. This resin-attached film can be suitably used to produce a wiring board having an insulating layer containing a cured product having a high dielectric constant and a low dielectric dissipation factor. For example, a multilayer wiring board can be produced by laminating the resin-attached film on a wiring board and then peeling off the support film, or by laminating the resin-attached film on a wiring board after peeling off the support film. A wiring board obtained using such a resin-attached film can have an insulating layer containing a cured product having a high dielectric constant and a low dielectric dissipation factor. Furthermore, a cured product obtained from the resin composition not only has a high dielectric constant and a low dielectric dissipation factor, but also a low thermal expansion coefficient and excellent adhesion to metal foil. For this reason, a wiring board obtained using a resin-coated film having a resin layer containing the resin composition or a semi-cured product of the resin composition not only has a high relative dielectric constant and a low dielectric tangent, but also has an insulating layer with a low thermal expansion coefficient and excellent adhesion to metal foil.

[0155] According to the present invention, there is provided a resin composition that can give a cured product having a high dielectric constant and a low dielectric loss tangent. Furthermore, according to the present invention, there are provided a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that can be obtained using the resin composition.

[0156] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples. [Example]

[0157] [Examples 1 to 18 and Comparative Examples 1 to 4] In this example, each component used in the resin composition will be described.

[0158] (Polyphenylene ether compound (A): PPE) Modified PPE-1: a polyphenylene ether compound having a vinylbenzyl group (ethenylbenzyl group) at the end (OPE-2st 1200, Mn 1200, Mw 1600, manufactured by Mitsubishi Gas Chemical Company, Inc.; a modified polyphenylene ether compound represented by the above formula (10), in which Ar in formula (10) is a phenylene group, R1 to R3 are hydrogen atoms, and p is 1). Modified PPE-2: a polyphenylene ether compound having a vinylbenzyl group (ethenylbenzyl group) at the terminal (OPE-2st 2200, Mn 2200, Mw 3600, manufactured by Mitsubishi Gas Chemical Company, Inc.; a modified polyphenylene ether compound represented by the above formula (10), in which Ar in formula (10) is a phenylene group, R1 to R3 are hydrogen atoms, and p is 1). Modified PPE-3: A polyphenylene ether compound having a vinylbenzyl group (ethenylbenzyl group) at the end (a modified polyphenylene ether compound obtained by reacting polyphenylene ether with chloromethylstyrene).

[0159] Specifically, it is a modified polyphenylene ether compound obtained by the following reaction.

[0160] First, 200 g of polyphenylene ether (SA90 manufactured by SABIC Innovative Plastics, 2 terminal hydroxyl groups, weight-average molecular weight Mw 1700), 30 g of a 50:50 mass ratio mixture of p-chloromethylstyrene and m-chloromethylstyrene (chloromethylstyrene: CMS manufactured by Tokyo Chemical Industry Co., Ltd.), 1.227 g of tetra-n-butylammonium bromide as a phase transfer catalyst, and 400 g of toluene were charged into a 1-liter three-neck flask equipped with a temperature controller, stirrer, cooling equipment, and dropping funnel, and the mixture was stirred. The mixture was then stirred until the polyphenylene ether, chloromethylstyrene, and tetra-n-butylammonium bromide were dissolved in the toluene. The mixture was gradually heated until the liquid temperature reached 75°C. An aqueous sodium hydroxide solution (20 g sodium hydroxide / 20 g water) was added dropwise to the solution as an alkali metal hydroxide over 20 minutes. The mixture was then stirred at 75°C for an additional 4 hours. Next, the contents of the flask were neutralized with 10% by mass of hydrochloric acid, and then a large amount of methanol was added. This caused a precipitate to form in the liquid in the flask. In other words, the product contained in the reaction solution in the flask was reprecipitated. This precipitate was then filtered, washed three times with a mixture of methanol and water in an 80:20 mass ratio, and then dried under reduced pressure at 80°C for 3 hours.

[0161] The obtained solid is 1 The solid was analyzed by H-NMR (400 MHz, CDCl3, TMS). As a result of NMR measurement, a peak derived from a vinylbenzyl group (ethenylbenzyl group) was confirmed at 5 to 7 ppm. This confirmed that the obtained solid was a modified polyphenylene ether compound having a vinylbenzyl group (ethenylbenzyl group) as the substituent at the molecular end. Specifically, it was confirmed that it was an ethenylbenzylated polyphenylene ether. The obtained modified polyphenylene ether compound was represented by the above formula (11), in which Y in formula (11) was a dimethylmethylene group (represented by formula (9), and R in formula (9) 33 and R 34The compound was a modified polyphenylene ether compound in which Ar was a phenylene group, R1 to R3 were hydrogen atoms, and p was 1.

[0162] The number of terminal functional groups of the modified polyphenylene ether was measured as follows.

[0163] First, the modified polyphenylene ether was accurately weighed. The weight at that time was designated X (mg). Then, this weighed modified polyphenylene ether was dissolved in 25 mL of methylene chloride, and 100 μL of a 10 mass% ethanol solution of tetraethylammonium hydroxide (TEAH) (TEAH:ethanol (volume ratio) = 15:85) was added to the solution, and the absorbance (Abs) at 318 nm was measured using a UV spectrophotometer (UV-1600, manufactured by Shimadzu Corporation). Then, from the measurement results, the number of terminal hydroxyl groups of the modified polyphenylene ether was calculated using the following formula.

[0164] Residual OH amount (μmol / g) = [(25×Abs) / (ε×OPL×X)]×10 6 where ε is the extinction coefficient, 4700 L / mol cm, and OPL is the cell path length, 1 cm.

[0165] The calculated residual OH amount (number of terminal hydroxyl groups) of the modified polyphenylene ether was almost zero, which indicated that the hydroxyl groups of the polyphenylene ether before modification were almost entirely modified. This indicated that the decrease in the number of terminal hydroxyl groups from the polyphenylene ether before modification was the number of terminal hydroxyl groups of the polyphenylene ether before modification. In other words, it was found that the number of terminal hydroxyl groups of the polyphenylene ether before modification was the number of terminal functional groups of the modified polyphenylene ether. In other words, the number of terminal functional groups was two.

[0166] The intrinsic viscosity (IV) of the modified polyphenylene ether was measured in methylene chloride at 25°C. Specifically, the intrinsic viscosity (IV) of the modified polyphenylene ether was measured using a viscometer (AVS500 Visco System manufactured by Schott) for a 0.18 g / 45 ml methylene chloride solution (liquid temperature 25°C) of the modified polyphenylene ether. As a result, the intrinsic viscosity (IV) of the modified polyphenylene ether was 0.086 dL / g.

[0167] The molecular weight distribution of the modified polyphenylene ether was measured using GPC. The weight average molecular weight (Mw) was calculated from the obtained molecular weight distribution. As a result, Mw was 1,900.

[0168] Modified PPE-4: Modified polyphenylene ether in which the terminal hydroxyl group of polyphenylene ether is modified with a methacryloyl group (represented by the above formula (12), in which Y in formula (12) is a dimethylmethylene group (represented by formula (9), in which R 33 and R 34 modified polyphenylene ether compound (wherein each methyl group is a group), SA9000 manufactured by SABIC Innovative Plastics, weight average molecular weight Mw 1700, number of terminal functional groups 2)

[0169] (Maleimide compound (B)) Maleimide compound-1: bisphenol A diphenyl ether bismaleimide (BMI-4000 manufactured by Daiwa Chemical Industry Co., Ltd., maleimide functional group equivalent weight 285 g / eq., molecular weight 570) Maleimide compound-2: Polyphenylmethane maleimide (BMI-2300 manufactured by Daiwa Chemical Industry Co., Ltd., functional group equivalent weight of maleimide group: 180 g / eq., molecular weight: 538) Maleimide compound-3: A maleimide compound represented by the above formula (17) (BMI-689 manufactured by Designer Molecules Inc., maleimide functional group equivalent weight: 344.5 g / eq., molecular weight: 689) Maleimide compound-4: A maleimide compound having a phenylmaleimide group and an indane structure in the molecule (a maleimide compound represented by the above formula (14), in which Ra represents a methyl group, q represents 2, and r represents 0, the functional group equivalent of the maleimide group is 428 g / eq., and the molecular weight is 856).

[0170] (Ceramic particles (C)) (Aluminum titanate particles (C1)) Aluminum titanate particles-1: Aluminum titanate particles produced by the precipitation method (ATB, manufactured by Kawai Lime Industry Co., Ltd., specific gravity 3.7 g / cm 3 , average particle size (D50) 2μm) Aluminum titanate particles-2: Aluminum titanate particles produced by the precipitation method (ATI manufactured by Kawai Lime Industry Co., Ltd., specific gravity 3.7 g / cm 3 , average particle size (D50) 2μm) Aluminum titanate particles-3: Aluminum titanate particles produced by the solid phase method (TM-19 manufactured by Marusu Glaze Co., Ltd., specific gravity 3.4 g / cm 3 , average particle size (D50) 7μm) (Ceramic particles (C2) other than aluminum titanate particles (C1): other ceramic particles) Strontium titanate particles: ST-A (specific gravity 5.1 g / cm) manufactured by Fuji Titanium Industry Co., Ltd. 3 , average particle size (D50) 1.6μm) Calcium titanate particles: CT (specific gravity 4g / cm) manufactured by Fuji Titanium Industry Co., Ltd. 3 , average particle size (D50) 2.1μm) Titanium dioxide particles: TM-1 (specific gravity 4.1 g / cm) manufactured by Fuji Titanium Industries Co., Ltd. 3 , average particle size (D50) 0.8μm) Silica particles: SC2500-SXJ (specific gravity 2.2 g / cm) manufactured by Admatechs Co., Ltd. 3 , average particle size (D50) 0.5μm) Aluminum oxide particles: AO-502 (specific gravity 3.8 g / cm) manufactured by Admatechs Co., Ltd. 3 , average particle size (D50) 0.3μm)

[0171] (Reaction initiator) PBP: Peroxide (α,α'-di(t-butylperoxy)diisopropylbenzene, Perbutyl P (PBP) manufactured by NOF Corporation)

[0172] [Preparation method] First, each component other than the ceramic particles (C) was added to toluene and mixed in the composition (parts by mass) shown in Tables 1 to 3 so that the solid content concentration was 50 mass%. The mixture was stirred for 60 minutes. Then, the ceramic particles (C) were added to the resulting liquid, and the ceramic particles (C) were dispersed using a bead mill. This resulted in a varnish-like resin composition (varnish).

[0173] Next, a prepreg and an evaluation substrate 1 (metal-clad laminate) were obtained as follows.

[0174] The obtained varnish was impregnated into a fibrous substrate (glass cloth: #1067 type, E-glass, manufactured by Asahi Kasei Corporation), and then heated and dried for 3 minutes at 120 to 150°C to produce a prepreg. At this time, the content of the components constituting the resin composition by the curing reaction relative to the prepreg (resin content) was adjusted to 73 to 80 mass%.

[0175] Next, an evaluation substrate 1 (metal-clad laminate) was obtained as follows.

[0176] Twelve sheets of each prepreg were stacked, and copper foil (GTHMP12, 12 μm thick, manufactured by Furukawa Electric Co., Ltd.) was placed on both sides. This was used as a pressure body, and was heated to 220°C at a temperature increase rate of 3°C / min, and then heated and pressurized at 220°C for 90 minutes under a pressure of 3 MPa, to obtain an evaluation substrate 1 (metal-clad laminate) with a thickness of approximately 0.8 mm and copper foil bonded to both sides.

[0177] The evaluation substrate 1 (metal-clad laminate) prepared as described above was evaluated by the following method.

[0178] [Dielectric properties (relative permittivity and dielectric loss tangent)] The copper foil was removed from the evaluation substrate 1 (metal-clad laminate) by etching to prepare an unclad board, which was used as a test specimen. The dielectric constant and dielectric loss tangent at 10 GHz were measured using a cavity resonator perturbation method. Specifically, a network analyzer (Agilent Technologies N5230A) was used to measure the dielectric constant and dielectric loss tangent of the evaluation substrate at 10 GHz. If the measured dielectric constant was 4 or higher, the test was judged to be "passed." Furthermore, if the measured dielectric loss tangent was 0.0055 or less, the test was judged to be "passed."

[0179] [Copper foil peel strength] The copper foil was peeled off from the evaluation substrate 1 (metal-clad laminate), and the peel strength at this time was measured in accordance with JIS C 6481 (1996). Specifically, a pattern 10 mm wide and 100 mm long was formed on the evaluation substrate, and the copper foil was peeled off at a rate of 50 mm / min using a tensile tester, and the peel strength (N / mm) at this time was measured. If the measured copper foil peel strength was 0.45 N / mm or more, it was judged to be "passed."

[0180] Next, separately from evaluation substrate 1, a prepreg and evaluation substrate 2 (metal-clad laminate) were obtained as follows.

[0181] The obtained varnish was impregnated into a fibrous substrate (glass cloth: #2116 type, E-glass, manufactured by Asahi Kasei Corporation), and then heated and dried for 3 minutes at 120 to 150°C to produce a prepreg. At this time, the content of the components constituting the resin composition by the curing reaction relative to the prepreg (resin content) was adjusted to 48 to 53 mass%.

[0182] Next, an evaluation substrate (metal-clad laminate) was obtained as follows.

[0183] Copper foil (GTHMP12, 12 μm thick, manufactured by Furukawa Electric Co., Ltd.) was placed on both sides of each of the obtained prepregs. This was used as a pressure body, and was heated to 220°C at a temperature increase rate of 3°C / min, and then heated and pressurized at 220°C for 90 minutes under a pressure of 3 MPa, to obtain an evaluation substrate 2 (metal-clad laminate) with a thickness of approximately 0.1 mm and copper foil bonded to both sides.

[0184] The evaluation substrate 2 (metal-clad laminate) prepared as described above was evaluated by the following method.

[0185] [Thermal expansion coefficient] The copper foil was removed from the evaluation substrate 2 (metal-clad laminate) by etching to prepare an unclad plate, which was used as a test specimen. The thermal expansion coefficient (CTE: ppm / °C) in the Y-axis direction was measured using the TMA method (thermo-mechanical analysis) in accordance with JIS C 6481. A TMA device (TMA6000 manufactured by SII NanoTechnology Inc.) was used for the measurement, and measurements were made in the temperature range of 30 to 260°C. If the measured thermal expansion coefficient was 14 ppm / °C or less, the specimen was judged to be "passed."

[0186] The results of the above evaluations are shown in Tables 1 to 3.

[0187] [Table 1]

[0188] [Table 2]

[0189] [Table 3]

[0190] Tables 1 to 3 show the compositions and evaluation results of resin compositions containing both the polyphenylene ether compound (A) and the maleimide compound (B), and resin compositions containing either the polyphenylene ether compound (A) or the maleimide compound (B). As can be seen from Tables 1 to 3, when metal-clad laminates were produced using the resin compositions, the resin compositions containing ceramic particles (C) including the aluminum titanate particles (C1) (Examples 1 to 18) had a dielectric constant of 4 or more and a dielectric dissipation factor of 0.0055 or less, unlike the resin compositions containing ceramic particles (C2) other than the aluminum titanate particles (C1) but not the aluminum titanate particles (C1) (Comparative Examples 1 to 4). This indicates that the resin compositions of Examples 1 to 18 can produce cured products with high dielectric constants and low dielectric dissipation factors, and metal-clad laminates having insulating layers containing such cured products can be produced. Furthermore, when metal-clad laminates were produced using the resin compositions of Examples 1 to 18, the coefficient of thermal expansion was 14 ppm / °C or less and the copper foil peel strength was 0.45 N / mm or more. This indicates that metal-clad laminates can be obtained that not only have a high relative dielectric constant and a low dielectric dissipation factor, but also a small coefficient of thermal expansion and high copper foil peel strength.

[0191] It can be seen that a metal-clad laminate having an insulating layer containing a cured product with a high dielectric constant and a low dielectric loss tangent can be obtained whether the content of the ceramic particles (C) containing the aluminum titanate particles (C1) is 110 parts by mass (for example, Example 3) or 200 parts by mass (Example 14) relative to 100 parts by mass of the total mass of the polyphenylene ether compound (A) and the maleimide compound (B). Note that in Example 3, where the content of the ceramic particles (C) containing the aluminum titanate particles (C1) is 110 parts by mass, the dielectric loss tangent is higher than in Example 14. Furthermore, in Example 14, where the content of the ceramic particles (C) containing the aluminum titanate particles (C1) is 200 parts by mass, the dielectric constant is higher than in Example 3. For these reasons, it is preferable that the content of the ceramic particles (C) including the aluminum titanate particles (C1) is not too small or too large, and for example, it is preferably 100 to 250 parts by mass per 100 parts by mass of the total mass of the polyphenylene ether compound (A) and the maleimide compound (B).

[0192] It can be seen that when the ceramic particles (C) contain not only the aluminum titanate particles (C1) but also ceramic particles (C2) other than the aluminum titanate particles (C1) (Examples 15 to 18), a metal-clad laminate having an insulating layer containing a cured product with a high dielectric constant and a low dielectric dissipation factor can be obtained. That is, it can be seen that even when the aluminum titanate particles (C1) and the ceramic particles (C2) are used in combination (Examples 15 to 18), a metal-clad laminate having an insulating layer containing a cured product with a high dielectric constant and a low dielectric dissipation factor can be obtained as long as the content of the ceramic particles (C) is within the above range.

[0193] This application is based on Japanese Patent Application No. 2021-050474, filed on March 24, 2021, the contents of which are incorporated herein by reference.

[0194] In order to express the present invention, the present invention has been properly and sufficiently described through the embodiments in the above, but it should be recognized that those skilled in the art can easily change and / or improve the above-mentioned embodiments. Therefore, unless the changes or improvements made by those skilled in the art are at a level that causes departure from the scope of the claims described in the claims, such changes or improvements are interpreted as being included in the scope of the claims. [Industrial Applicability]

[0195] The present invention provides a resin composition that can give a cured product having a high dielectric constant and a low dielectric loss tangent. The present invention also provides a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that can be obtained using the resin composition.

Claims

1. At least one of a polyphenylene ether compound (A) having in the molecule at least one of a group represented by the following formula (1) and a group represented by the following formula (2), and a maleimide compound (B); and ceramic particles (C) containing aluminum titanate particles (C1), The maleimide compound (B) includes at least one selected from the group consisting of polyphenylmethane maleimide, bisphenol A diphenyl ether bismaleimide, a maleimide compound having a phenylmaleimide group and an indane structure in the molecule, and a maleimide compound represented by the following formula (17): The resin composition has a content of the ceramic particles (C) of 100 to 250 parts by mass per 100 parts by mass of the polyphenylene ether compound (A) and the maleimide compound (B) combined. 【Chemistry 1】 [In formula (1), p represents 0 to 10, Ar represents an arylene group, and R １ ~R ３ each independently represents a hydrogen atom or an alkyl group. 【Chemistry 2】 [In formula (2), R ４ represents a hydrogen atom or an alkyl group. 【Transformation 3】

2. 2. The resin composition according to claim 1, wherein the ceramic particles (C) further comprise at least one selected from the group consisting of strontium titanate particles, calcium titanate particles, barium titanate particles, magnesium titanate particles, zinc titanate particles, lanthanum titanate particles, neodymium titanate particles, titanium dioxide particles, aluminum oxide particles, and silica particles.

3. A resin composition according to claim 1 or claim 2, wherein the polyphenylene ether compound (A) comprises at least one selected from the group consisting of polyphenylene ether compounds represented by the following formula (10), polyphenylene ether compounds represented by the following formula (11), and polyphenylene ether compounds represented by the following formula (12): 【Chemistry 4】 [In formula (10), m and n each represent an integer of 0 to 20, p represents an integer of 0 to 10, Ar represents an arylene group, and R 1 to R 3 each independently represent a hydrogen atom or an alkyl group.] 【Transformation 5】 [In formula (11), m and n each represent 0 to 20, p represents 0 to 10, Ar represents an arylene group, R 1 to R 3 each independently represent a hydrogen atom or an alkyl group, and Y represents a linear, branched, or cyclic hydrocarbon group having 20 or less carbon atoms.] 【Transformation 6】 [In formula (12), m and n each represent an integer of 0 to 20, R 4 represents a hydrogen atom or an alkyl group, and Y represents a linear, branched, or cyclic hydrocarbon group having 20 or less carbon atoms.]

4. A resin composition described in claim 1 or claim 2, wherein the maleimide compound having a phenylmaleimide group and an indane structure in the molecule includes a maleimide compound represented by the following formula (14): 【Transformation 7】

5. A prepreg comprising the resin composition according to any one of claims 1 to 4 or a semi-cured product of the resin composition and a fibrous base material.

6. 6. The prepreg according to claim 5, wherein a cured product of the prepreg has a relative dielectric constant of 4 or more and 6.9 or less at a frequency of 10 GHz, and a dielectric loss tangent of the cured product of the prepreg at a frequency of 10 GHz of 0.0032 or more and 0.0055 or less.

7. A resin-coated film comprising a resin layer containing the resin composition according to any one of claims 1 to 4 or a semi-cured product of the resin composition, and a support film.

8. A resin-coated metal foil comprising a resin layer containing the resin composition according to any one of claims 1 to 4 or a semi-cured product of the resin composition, and a metal foil.

9. A metal-clad laminate comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 4 or a cured product of the prepreg according to claim 5 or claim 6, and a metal foil.

10. The metal-clad laminate according to claim 9, wherein the insulating layer has a relative dielectric constant of 4 or more and 6.9 or less at a frequency of 10 GHz, and a dielectric loss tangent of the insulating layer at a frequency of 10 GHz of 0.0032 or more and 0.0055 or less.

11. A wiring board comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 4 or a cured product of the prepreg according to claim 5 or 6, and wiring.

12. 12. The wiring board according to claim 11, wherein the insulating layer has a relative dielectric constant of 4 or more and 6.9 or less at a frequency of 10 GHz, and a dielectric loss tangent of the insulating layer at a frequency of 10 GHz of 0.0032 or more and 0.0055 or less.

Images