Resin composition, prepreg, resin-attached film, resin-attached metal foil, metal-clad laminated plate, and wiring board

Abstract

A resin composition according to the present invention comprises: a polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond; a maleimide compound (B) having two or more N-substituted maleimide groups per molecule; and an inorganic filler (C) containing a titanic acid compound filler (C-1), wherein the titanic acid compound filler (C-1) includes one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide, and the total content of the one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide is not less than 50 mass% relative to the total amount of the inorganic filler (C) and is 100-400 parts by mass relative to 100 parts by mass of the polyphenylene ether compound (A) and the maleimide compound (B).

Description

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

[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.

[0002] Wiring boards used in electronic devices, for example, as wiring boards for antenna modules, 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, to meet demands for smaller antennas and finer wiring patterns, the substrate materials are also required to have a high relative dielectric constant.

[0003] For example, Patent Document 1 describes a resin composition having a high relative dielectric constant and a low dielectric loss tangent, which is suitable for use in producing an insulating layer of a printed wiring board, and a prepreg obtained using the resin composition. ４ O ９ (A) and BaTi ４ O ９ (A) and a filler (B) different from the filler (A), and a thermosetting resin (C), ４ O ９ (A) has an average particle size of 0.10 to 1.00 μm, and BaTi ４ O ９ (A) and filler (B) in a volume ratio (BaTi ４ O ９ It is described that the ratio of (A):filler (B) is in the range of 15:85 to 80:20.

[0004] International Publication No. 2022 / 172752

[0005] An object of the present invention is to provide a resin composition that can give a cured product having a high relative dielectric constant and a low dielectric loss tangent, and 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.

[0006] The present inventors have conducted extensive research to solve the above problems and have arrived at the present invention.

[0007] A resin composition according to a first aspect of the present invention is a resin composition comprising: a polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond; a maleimide compound (B) having two or more N-substituted maleimide groups in one molecule; and an inorganic filler (C) including a titanate compound filler (C-1), wherein the titanate compound filler (C-1) comprises one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide, and the total content of the one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide is 50% by mass or more relative to the total amount of the inorganic filler (C), and is 100 parts by mass or more and 400 parts by mass or less relative to 100 parts by mass of the polyphenylene ether compound (A) and the maleimide compound (B).

[0008] Fig. 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. Fig. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. Fig. 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. 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. Fig. 5 is a schematic cross-sectional view showing an example of a resin-coated film according to an embodiment of the present invention.

[0009] The resin composition described in Patent Document 1 mainly contains BaTi as an essential filler. ４ O ９ The physical properties of BaTi ４ O ９ By specifying the volume ratio of the inorganic filler to other fillers, etc., the effects of a high dielectric constant and a low dielectric loss tangent can be achieved. However, with such a resin composition, although the dielectric constant can be increased to a certain extent, it is difficult to reduce the dielectric loss tangent to a desired value. Furthermore, while the dielectric constant of the cured product can generally be increased by adding an inorganic filler with a high dielectric constant to the resin composition, simply adding an inorganic filler with a high dielectric constant often results in a high dielectric loss tangent.

[0010] As described above, the resin compositions reported to date as substrate materials for insulating layers in high-frequency wiring boards still have room for improvement in terms of both a high dielectric constant and a low dielectric loss tangent.

[0011] As a result of intensive research by the present inventors, it has been found that in a resin composition containing a predetermined polyphenylene ether compound (A), a predetermined maleimide compound (B), and an inorganic filler (C) containing a titanate compound filler (C-1), by adjusting the total content of one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide in the titanate compound filler (C-1) so as to satisfy specific conditions, a cured resin composition having a high relative dielectric constant and a low dielectric loss tangent can be obtained.

[0012] That is, the present invention provides a resin composition that can give a cured product having a high dielectric constant and a low dielectric loss tangent. Furthermore, by using the resin composition, it is possible to provide a prepreg, a resin-coated film, a resin-coated metal foil, a metal-clad laminate, and a wiring board that have excellent performance.

[0013] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Note that the scope of the present invention is not limited to the embodiments described here, and various modifications can be made without departing from the spirit of the present invention.

[0014] <Resin Composition> The resin composition according to this embodiment (hereinafter also simply referred to as "resin composition") contains a polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond, a maleimide compound (B) having two or more N-substituted maleimide groups in one molecule, and an inorganic filler (C) containing a titanic acid compound filler (C-1).

[0015] Hereinafter, each component contained in the resin composition, the physical properties of the resin composition, uses of the resin composition, and a method for preparing the resin composition will be described in detail.

[0016] [Polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond] The polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond is not particularly limited, as long as it is a modified polyphenylene ether compound terminally modified with a substituent having a carbon-carbon unsaturated double bond (hereinafter simply referred to as "modified polyphenylene ether compound (A)"). When a resin composition contains such a modified polyphenylene ether compound (A), the dielectric dissipation factor of a cured product of the resin composition can be reduced. In addition, since the modified polyphenylene ether compound (A) exhibits high reactivity with the maleimide compound (B) described below, it is believed that the glass transition temperature of a cured product of the resin composition and the adhesion of the resin composition to a metal foil can be increased.

[0017] The modified polyphenylene ether compound (A) preferably comprises a polyphenylene ether compound having at least one group selected from a group represented by the following formula (1) and a group represented by the following formula (2): In short, the modified polyphenylene ether compound (A) preferably comprises a polyphenylene ether compound that is terminally modified with at least one group selected from a group represented by the following formula (1) and a group represented by the following formula (2), and has at a molecular end at least one group selected from a group represented by the following formula (1) and a group represented by the following formula (2):

[0018] [In formula (1), p represents an integer of 0 to 10, Ar represents an arylene group, and R １ ~R ３ each independently represents a hydrogen atom or an alkyl group.

[0019] [In formula (2), R ４ represents a hydrogen atom or an alkyl group.

[0020] When the modified polyphenylene ether compound (A) contains the polyphenylene ether compound described above, the dielectric loss tangent of the cured product of the resin composition can be more reliably reduced.

[0021] In the above formula (1), the arylene group is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as phenylene groups, and polycyclic aromatic groups such as naphthalene rings. In addition, the arylene group represented by Ar in the above formula (1) also includes derivatives in which the 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.

[0022] In the above formula (1) and formula (2), the alkyl group is not particularly limited, and is preferably, for example, an alkyl group having 1 to 18 carbon atoms, and more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0023] Examples of the group represented by the formula (1) include a vinylbenzyl group (ethenylbenzyl group) represented by the following formula (3): Furthermore, examples of the group represented by the formula (2) include an acryloyl group and a methacryloyl group.

[0024]

[0025] More specific examples of the substituent (at least one of the group represented by the formula (1) and the group represented by the formula (2)) include vinylbenzyl groups (ethenylbenzyl groups) such as o-ethenylbenzyl group, m-ethenylbenzyl group, and p-ethenylbenzyl group, vinylphenyl group, acryloyl group, methacryloyl group, etc. The modified polyphenylene ether compound (A) may have one type of such substituent, or may have two or more types.

[0026] The modified polyphenylene ether compound (A) 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.

[0027]

[0028] In the above formula (4), t represents 1 to 50. ５ ~R８ are each independently any group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, and an alkynylcarbonyl group. ５ ~R ８ are preferably each independently either a hydrogen atom or an alkyl group.

[0029] R ５ ~R ８ The alkyl group in 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 of the alkyl group include a methyl group, an ethyl group, a propyl group, a hexyl group, and a decyl group.

[0030] 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 of the alkenyl group include a vinyl group, an allyl group, and a 3-butenyl group.

[0031] 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 of the alkynyl group include an ethynyl group and a prop-2-yn-1-yl group (propargyl group).

[0032] 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 of the alkylcarbonyl group 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.

[0033] 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 of the alkenylcarbonyl group include an acryloyl group, a methacryloyl group, and a crotonoyl group.

[0034] 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 of the alkynylcarbonyl group include a propioloyl group.

[0035] Examples of the modified polyphenylene ether compound (A) include a polyphenylene ether compound represented by the following formula (5) and a polyphenylene ether compound represented by the following formula (6). As the modified polyphenylene ether compound (A), such a modified polyphenylene ether compound (A) may be used alone, or two or more modified polyphenylene ether compounds (A) may be used in combination.

[0036]

[0037]

[0038] In the above formula (5) and the above formula (6), R ９ ~R １６ and R １７ ~R ２４ are each independently any group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, and an alkynylcarbonyl group. ９ ~R １６ and R １７ ~R ２４ are preferably each independently any group selected from the group consisting of a hydrogen atom and an alkyl group. １ and X２ each independently represents 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 the above formula (6), Y represents a linear, branched, or cyclic hydrocarbon having 20 or less carbon atoms.

[0039]

[0040]

[0041] In the formulas (7) and (8), m and n each preferably represent an integer of 0 to 20. The sum of m and n preferably represents a value of 1 to 30. R ２５ ~R ２８ and R ２９ ~R ３２ are each independently any group selected from the group consisting of a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkylcarbonyl group, an alkenylcarbonyl group, and an alkynylcarbonyl group. ２５ ~R ２８ and R ２９ ~R ３２ are preferably each independently either a hydrogen atom or an alkyl group.

[0042] In short, R in the above formulas (5) to (8) ９ ~R ３２ Specific examples of the functional group include R ５ ~R ８ is the same as:

[0043] The modified polyphenylene ether compound (A) represented by the above formula (5) and the modified polyphenylene ether compound (A) represented by the above formula (6) are not particularly limited as long as they are compounds that satisfy the above constitution.

[0044] In addition, in the above formula (6), examples of Y include groups represented by the following formula (9).

[0045]

[0046] In the above formula (9), R３３ and R ３４ are each independently a group selected from the group consisting of a hydrogen atom and an alkyl group. Examples of the alkyl group include a methyl group. Examples of the group represented by the above formula (9) include a methylene group, a methylmethylene group, and a dimethylmethylene group. Of these, the group represented by the above formula (9) is preferably a dimethylmethylene group.

[0047] A specific example of the modified polyphenylene ether compound (A) represented by the above formula (5) is a polyphenylene ether compound represented by the following formula (10).

[0048]

[0049] Specific examples of the modified polyphenylene ether compound (A) represented by the above formula (6) include a polyphenylene ether compound represented by the following formula (11) and a polyphenylene ether compound represented by the following formula (12):

[0050]

[0051]

[0052] In the formulas (10) to (12), m and n are the same as m and n in the formulas (7) and (8). １ ~R ３ , p and Ar are R in the above formula (1). １ ~R ３ , p and Ar. In the formulas (11) and (12), Y is the same as Y in the formula (6). In the formula (12), R ４ is R in the above formula (2). ４ is the same as

[0053] The modified polyphenylene ether compound (A) may be synthesized by any method known to those skilled in the art. One example of the synthesis method is a method in which a polyphenylene ether compound and a compound to which a substituent having a carbon-carbon unsaturated double bond and a halogen atom are bonded are dissolved in a solvent, the mixture is stirred, and the stirred mixture is reacted preferably in the presence of an alkali metal hydroxide and a phase transfer catalyst.

[0054] Alternatively, the modified polyphenylene ether compound (A) may be a commercially available product, such as "OPE-2st 1200" or "OPE-2st 2200" manufactured by Mitsubishi Gas Chemical Company, Inc., or "SA9000" manufactured by SABIC Innovative Plastics.

[0055] The modified polyphenylene ether compound (A) is not particularly limited, but preferably contains a modified polyphenylene ether compound having at least one of a weight average molecular weight (Mw) and a number average molecular weight (Mn) of 1,000 to 5,000.

[0056] Specifically, the weight-average molecular weight (Mw) of the modified polyphenylene ether compound (A) is preferably 1,000 to 5,000, and more preferably 1,000 to 4,000. In this specification, the weight-average molecular weight (Mw) of the modified polyphenylene ether compound (A) is a value measured using gel permeation chromatography (GPC), a common molecular weight measurement method. Furthermore, when the modified polyphenylene ether compound (A) has a repeating unit represented by the above formula (4), for example, a repeating unit t represented by the above formula (4) in the molecule, t is preferably a value such that the weight-average molecular weight of the modified polyphenylene ether compound (A) falls within this range. When the weight-average molecular weight (Mw) of the modified polyphenylene ether compound (A) falls within this range, it is believed that the cured product will have a low dielectric tangent and glass transition temperature, and the resin composition will have excellent adhesion to metal foil.

[0057] The number average molecular weight (Mn) of the modified polyphenylene ether compound (A) is not particularly limited either, but is preferably 1,000 to 5,000, and more preferably 1,000 to 4,000.

[0058] The average number of the substituents at the molecular terminals per molecule of the modified polyphenylene ether compound (A) (the number of terminal functional groups of the modified polyphenylene ether compound (A)) is not particularly limited. Specifically, the number of terminal functional groups is preferably 1 to 5, and more preferably 1 to 3. When the number of terminal functional groups is within this range, it is considered to be preferable from the viewpoints of the heat resistance of the cured product and the storage stability, flowability, and moldability of the resin composition.

[0059] The "number of terminal functional groups of the modified polyphenylene ether compound (A)" means a numerical value representing the average number of the substituents per molecule of all the modified polyphenylene ether compounds (A) present in 1 mole of the modified polyphenylene ether compound (A).

[0060] The content of the modified polyphenylene ether compound (A) is not particularly limited, but is preferably 30% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on the total amount of the resin components including the modified polyphenylene ether compound (A). The content of the modified polyphenylene ether compound (A) is preferably 90% by mass or less, more preferably 75% by mass or less, and even more preferably 65% ​​by mass or less, based on the total amount of the resin components including the modified polyphenylene ether compound (A).

[0061] In this specification, the term "resin component" refers to the modified polyphenylene ether compound (A) and the maleimide compound (B) described later contained in the resin composition, as well as the optionally contained curing agent described later.

[0062] Furthermore, the mass ratio of the modified polyphenylene ether compound (A) to the maleimide compound (B) described below (modified polyphenylene ether compound (A):maleimide compound (B)) is preferably 20:80 to 80:20, more preferably 30:70 to 70:30, and even more preferably 40:60 to 60:40. By setting the mass ratio of the modified polyphenylene ether compound (A) to the maleimide compound (B) within this range, it is possible to reduce the low dielectric tangent while maintaining a high relative dielectric constant of the cured product. Furthermore, it is believed that the effects can be more reliably obtained in terms of high adhesion, low thermal expansion coefficient, and high glass transition temperature.

[0063] [Maleimide Compound (B) Having Two or More N-Substituted Maleimide Groups in One Molecule] The maleimide compound (B) having two or more N-substituted maleimide groups in one molecule (hereinafter simply referred to as "maleimide compound (B)") is not particularly limited as long as it is a maleimide compound having two or more N-substituted maleimide groups in one molecule. When a resin composition contains the maleimide compound (B), the dielectric loss tangent of the cured resin composition can be reduced. Furthermore, since the maleimide compound (B) reacts efficiently with the modified polyphenylene ether compound (A) described above, it is thought that high heat resistance can be obtained. In addition, it is thought that this contributes to a high glass transition temperature of the cured resin composition.

[0064] A preferred example of the maleimide compound (B) is a maleimide compound (B) having a phenylmaleimide group in the molecule. By using a maleimide compound (B) having a phenylmaleimide group in the molecule, the glass transition temperature of the cured product of the resin composition can be increased.

[0065] Examples of the maleimide compound (B) include 4,4'-diphenylmethane bismaleimide, polyphenylmethane maleimide, m-phenylene bismaleimide, 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane, 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide, 4-methyl-1,3-phenylene bismaleimide, biphenylaralkyl maleimide resins, and maleimide compounds having a phenylmaleimide group and an arylene structure substituted at the meta position in the molecule.

[0066] Commercially available products can be used as such maleimide compound (B). Specifically, for example, "BMI-1000" manufactured by Daiwa Chemical Industry Co., Ltd. can be used as 4,4'-diphenylmethane bismaleimide. For example, "BMI-2300" manufactured by Daiwa Chemical Industry Co., Ltd. can be used as polyphenylmethane maleimide. For example, "BMI-3000" manufactured by Daiwa Chemical Industry Co., Ltd. can be used as m-phenylene bismaleimide. For example, "BMI-80" manufactured by K.I. Kasei Co., Ltd. can be used as 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane. For example, "BMI-5100" manufactured by Daiwa Chemical Industry Co., Ltd. can be used as 3,3'-dimethyl-5,5'-diethyl-4,4'-diphenylmethane bismaleimide. As the 4-methyl-1,3-phenylene bismaleimide, for example, "BMI-7000" manufactured by Daiwa Kasei Kogyo 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 mentioned, and for example, "MIR-5000" manufactured by Nippon Kayaku Co., Ltd. can be used. In the following formula (13), s represents 1 to 5.

[0067]

[0068] Alternatively, another preferred example of the maleimide compound (B) is a maleimide compound (B) having an aliphatic hydrocarbon group in the molecule but not a phenylmaleimide group in the molecule. The aliphatic hydrocarbon group is not particularly limited, and preferably has 20 or more carbon atoms, more preferably 30 or more carbon atoms. Such an aliphatic hydrocarbon group may be linear, may have a branched structure within the group, or may have an alicyclic structure within the group.

[0069] Examples of such maleimide compounds (B) include maleimide compounds represented by the following formulas (14) to (17). Commercially available products can be used as such maleimide compounds. Specifically, for example, BMI-1500 manufactured by Designer Molercules Inc. can be used as the maleimide compound represented by the following formula (14). For example, BMI-1700 manufactured by Designer Molercules Inc. can be used as the maleimide compound represented by the following formula (15). For example, BMI-689 manufactured by Designer Molercules Inc. can be used as the maleimide compound represented by the following formula (16). For example, BMI-3000 manufactured by Designer Molercules Inc. can be used as the maleimide compound represented by the following formula (17).

[0070]

[0071]

[0072]

[0073]

[0074] These maleimide compounds (B) may be used alone or in combination of two or more.

[0075] The average molecular weight of the maleimide compound (B) is preferably 400 to 2000, more preferably 400 to 1500, and even more preferably 500 to 1000. In this specification, the average molecular weight of the maleimide compound (B) is a value measured using gel permeation chromatography (GPC), a common molecular weight measurement method. Note that when the maleimide compound (B) is a polymer such as an oligomer, the "average molecular weight of the maleimide compound (B)" refers to the number average molecular weight.

[0076] The functional group equivalent of the maleimide group of the maleimide compound (B) is not particularly limited, but is preferably 200 g / eq. to 1000 g / eq., more preferably 200 g / eq. to 600 g / eq., and even more preferably 200 g / eq. to 400 g / eq. When the functional group equivalent of the maleimide group of the maleimide compound (B) is within this range, it is believed that the dielectric tangent of the cured product can be reduced while maintaining a low water absorption rate.

[0077] The content of the maleimide compound (B) is not particularly limited, but is preferably 20% by mass or more, more preferably 35% by mass or more, and even more preferably 40% by mass or more, based on the total amount of the resin components including the maleimide compound (B). The content of the maleimide compound (B) is preferably 90% by mass or less, more preferably 75% by mass or less, and even more preferably 65% ​​by mass or less, based on the total amount of the resin components including the maleimide compound (B).

[0078] The mass ratio between the maleimide compound (B) and the modified polyphenylene ether compound (A) is as described above.

[0079] [Inorganic Filler (C)] (Titanium Acid Compound Filler (C-1)) The inorganic filler (C) contains a titanate compound filler (C-1). Furthermore, the titanate compound filler (C-1) as the inorganic filler (C) contains one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide (one or more fillers made of a material selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide).

[0080] By including one or more fillers selected from these as the inorganic filler (C), the dielectric constant of the cured product can be increased. From the viewpoint of being able to more reliably increase the dielectric constant of the cured product, the titanate compound filler (C-1) preferably includes one or more fillers selected from the group consisting of strontium titanate and calcium titanate (one or more fillers made of a material selected from the group consisting of strontium titanate and calcium titanate). Furthermore, from the viewpoint of being able to particularly increase the dielectric constant of the cured product, it is more preferable that the titanate compound filler (C-1) includes a strontium titanate filler (a filler made of a strontium titanate material).

[0081] Furthermore, in the resin composition according to this embodiment, the total content of one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide is 50 mass% or more relative to the total amount of the inorganic filler (C), and satisfies the conditions of 100 parts by mass or more and 400 parts by mass or less relative to 100 parts by mass of the modified polyphenylene ether compound (A) and the maleimide compound (B).

[0082] When the total content is 50% by mass or more relative to the total amount of the inorganic filler (C) and 100 parts by mass or more relative to 100 parts by mass of the modified polyphenylene ether compound (A) and the maleimide compound (B), the cured product of the resin composition can be increased to a desired relative dielectric constant (for example, a relative dielectric constant of 5.0 or more at a frequency of 10 GHz). Furthermore, when the total content is 400 parts by mass or less relative to 100 parts by mass of the modified polyphenylene ether compound (A) and the maleimide compound (B), the dielectric loss tangent of the cured product of the resin composition can be maintained at a low value. It is also believed that the moldability of the resin composition can be maintained in a good state.

[0083] The total content of one or more fillers selected from the three fillers is preferably 60% by mass or more, more preferably 75% by mass or more, even more preferably 85% by mass or more, and particularly preferably a value selected from the group consisting of 87% by mass, 90% by mass, 93% by mass, and 95% by mass or more, relative to the total amount of inorganic filler (C). The upper limit of the total content of one or more fillers selected from the three fillers is not particularly limited, and the content may be 100% by mass relative to the total amount of inorganic filler (C).

[0084] The total content of one or more fillers selected from the three types of fillers is preferably 120 parts by mass or more, more preferably 130 parts by mass or more, and even more preferably 135 parts by mass or more, and particularly preferably 140 parts by mass or more, relative to 100 parts by mass of the modified polyphenylene ether compound (A) and the maleimide compound (B). The total content of one or more fillers selected from the three types of fillers is preferably 380 parts by mass or less, more preferably 360 parts by mass or less, even more preferably 340 parts by mass or less, and particularly preferably 330 parts by mass or less, 320 parts by mass, 310 parts by mass, 300 parts by mass, 290 parts by mass, 280 parts by mass, and 270 parts by mass or less, relative to 100 parts by mass of the modified polyphenylene ether compound (A) and the maleimide compound (B).

[0085] The shape of one or more fillers selected from the three types of fillers is preferably particulate. Specifically, the titanate compound filler (C-1) preferably contains one or more fillers selected from the group consisting of strontium titanate particles, calcium titanate particles, and titanium oxide particles. These particles are not particularly limited, and examples thereof include titanate compound particles obtained by general synthesis methods such as precipitation, solid-phase, and electrofusion.

[0086] When one or more fillers selected from the three fillers are in particulate form, the average particle size (cumulative 50% diameter on a volume basis (D50)) of the strontium titanate particles, calcium titanate particles, and / or titanium oxide particles is not particularly limited, but is preferably 0.1 μm to 10 μm, more preferably 0.5 μm to 5 μm, and even more preferably 0.5 μm to 3 μm. When one or more fillers selected from the three fillers have an average particle size within this range, it is believed that the dielectric constant of the cured product of the obtained resin composition can be more reliably increased, and the moldability of the resin composition from a semi-cured state can be improved.

[0087] When one or more fillers selected from the three types of fillers are in a particulate form, the specific gravity of the strontium titanate particles, calcium titanate particles, and / or titanium oxide particles is not particularly limited, but is, for example, 3 g / cm ３ ~6g / cm ３ 3 g / cm ３ ~5.5g / cm ３ It is more preferable that:

[0088] The titanate compound filler (C-1) as the inorganic filler (C) may contain a titanate compound filler (C-1) other than strontium titanate, calcium titanate, and titanium oxide, as long as the conditions for the total content of strontium titanate, calcium titanate, and titanium oxide according to the present embodiment described above are satisfied and the effects of the high dielectric constant and low dielectric dissipation factor according to the present embodiment are not impaired. Examples of such titanate compound fillers (C-1) include fillers such as aluminum titanate, magnesium titanate, zinc titanate, lanthanum titanate, neodymium titanate, and barium titanate (more specifically, fillers made of these materials).

[0089] (Other Filler (C-2)) The inorganic filler (C) may further contain another filler (C-2) different from the titanate compound filler (C-1), as long as the inorganic filler (C) satisfies the conditions regarding the total content of strontium titanate, calcium titanate, and titanium oxide according to the present embodiment described above and does not impair the effects of the high dielectric constant and low dielectric dissipation factor according to the present embodiment. When the resin composition further contains another filler (C-2) different from the titanate compound filler (C-1), effects such as low dielectric dissipation factor, improved heat resistance, and flame retardancy, and suppression of the thermal expansion coefficient in the cured product of the resin composition can be expected.

[0090] Specifically, examples of the other filler (C-2) include fillers such as metal oxides, metal hydroxides, molybdates, nitrides, titanates, magnesium carbonate such as anhydrous magnesium carbonate, calcium carbonate, quartz glass, talc, aluminum borate, and barium sulfate (more specifically, fillers made of these materials).

[0091] Specifically, examples of metal oxide fillers include fillers such as silica, alumina, magnesium oxide, and mica (specifically, fillers made of these materials). Examples of metal hydroxide fillers include fillers such as magnesium hydroxide and aluminum hydroxide (specifically, fillers made of these materials). Examples of molybdate fillers include fillers such as zinc molybdate, calcium molybdate, and magnesium molybdate (specifically, fillers made of these materials). Examples of nitride fillers include fillers such as aluminum nitride and boron nitride (specifically, fillers made of these materials). Of these, it is preferable that the other filler (C-2) includes a silica filler. Furthermore, these other fillers (C-2) may be used alone or in combination of two or more.

[0092] When the resin composition contains another filler (C-2), the content thereof may be adjusted as appropriate within a range that satisfies the conditions regarding the total content of strontium titanate, calcium titanate, and titanium oxide according to this embodiment, as described above, and does not impair the effects of the high relative dielectric constant and low dielectric dissipation factor according to this embodiment.

[0093] The content of the other filler (C-2) (the total content when multiple types of other fillers (C-2) are included) needs to be set appropriately depending on the type of filler. For example, the content of the other filler (C-2) is preferably 40% by mass or less, more preferably 25% by mass or less, even more preferably 15% by mass or less, and particularly preferably 5% by mass or less, based on the total amount of the inorganic filler (C).

[0094] The titanate compound filler (C-1) and any other filler (C-2) optionally contained as the inorganic filler (C) may be surface-treated inorganic filler (C). Examples of such surface treatments include treatment with a silane coupling agent, which will be described later.

[0095] [Reaction initiator (D)] The resin composition may contain a reaction initiator (D) (catalyst). The reaction initiator (D) is not particularly limited as long as it can accelerate the curing reaction of the resin composition. Specific examples of the reaction initiator (D) include azo compounds, peroxides, metal oxides, imidazole compounds, phosphorus-based curing accelerators, and amine-based curing accelerators.

[0096] Examples of the azo compound include 2,2'-azobis(2,4,4-trimethylpentane), 2,2'-azobis(N-butyl-2-methylpropionamide), and 2,2'-azobis(2-methylbutyronitrile).

[0097] Examples of peroxides include α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3',5,5'-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, t-butylperoxyisopropyl monocarbonate, and azobisisobutyronitrile.

[0098] Examples of metal oxides include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

[0099] Such a reaction initiator (D) may be used alone or in combination of two or more.

[0100] When the resin composition contains the reaction initiator (D), the content thereof may be appropriately set so as not to impair the effects of the high relative dielectric constant and low dielectric dissipation factor according to the present embodiment, and may be, for example, 0.05 parts by mass or more and 2 parts by mass or less per 100 parts by mass of the resin component.

[0101] [Silane coupling agent (E)] The resin composition may contain a silane coupling agent (E). The silane coupling agent (E) may be contained in the resin composition as an additive, or may be contained in the inorganic filler (C) contained in the resin composition as a silane coupling agent (E) that has been previously surface-treated. In addition, in the case of a prepreg, the prepreg may contain the silane coupling agent (E) as a silane coupling agent (E) that has previously surface-treated a fibrous substrate.

[0102] The silane coupling agent (E) is not particularly limited, but examples thereof include silane coupling agents (E) 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.

[0103] Examples of the silane coupling agent (E) having a vinyl group include vinyltriethoxysilane and vinyltrimethoxysilane. Examples of the silane coupling agent (E) having a styryl group include p-styryltrimethoxysilane and p-styryltriethoxysilane. Examples of the silane coupling agent (E) having a methacryloyl group include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, and 3-methacryloxypropylethyldiethoxysilane. Examples of the silane coupling agent (E) having an acryloyl group include 3-acryloxypropyltrimethoxysilane and 3-acryloxypropyltriethoxysilane. Examples of the silane coupling agent (E) having a phenylamino group include N-phenyl-3-aminopropyltrimethoxysilane and N-phenyl-3-aminopropyltriethoxysilane.

[0104] These silane coupling agents (E) may be used singly or in combination of two or more.

[0105] When the resin composition contains the silane coupling agent (E), the content thereof may be appropriately set so as not to impair the effects of the high relative dielectric constant and low dielectric dissipation factor according to this embodiment, and may be, for example, 0.05 parts by mass or more and 3 parts by mass or less per 100 parts by mass of the resin component.

[0106] [Other Components] The resin composition may contain, as necessary, components other than the modified polyphenylene ether compound (A), the inorganic filler (C) containing the maleimide compound (B) and the titanic acid compound filler (C-1), as well as the optionally contained reaction initiator (D) and silane coupling agent (E). Examples of other components include additives such as curing agents, flame retardants, curing accelerators, polymerization retarders, polymerization inhibitors, dispersants, leveling agents, antifoaming agents, antioxidants, heat stabilizers, antistatic agents, ultraviolet absorbers, dyes, pigments, and lubricants, as long as the effects of the high dielectric constant and low dielectric dissipation factor according to this embodiment are not impaired.

[0107] The resin composition may optionally contain a curing agent that reacts with at least one of the modified polyphenylene ether compound (A) and the maleimide compound (B) to contribute to curing of the resin composition, as long as the effects of the high dielectric constant and low dielectric loss tangent according to this embodiment 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.

[0108] Examples of epoxy compounds 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, naphthalene ring-containing epoxy compounds, etc. Furthermore, the epoxy compounds also include epoxy resins, which are polymers of each epoxy compound.

[0109] Examples of the methacrylate compound include monofunctional methacrylate compounds and polyfunctional methacrylate compounds. Examples of the monofunctional methacrylate compound include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, etc. Examples of the polyfunctional methacrylate compound include dimethacrylate compounds such as tricyclodecane dimethanol dimethacrylate (DCP).

[0110] Examples of the acrylate compound include monofunctional acrylate compounds and polyfunctional acrylate compounds. Examples of the monofunctional acrylate compound include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, etc. Examples of the polyfunctional acrylate compound include diacrylate compounds such as tricyclodecane dimethanol diacrylate.

[0111] Examples of the cyanate ester compound include 2,2-bis(4-cyanatephenyl)propane, bis(3,5-dimethyl-4-cyanatephenyl)methane, and 2,2-bis(4-cyanatephenyl)ethane.

[0112] Examples of the active ester compound 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.

[0113] Examples of the benzoxazine compound include benzoxazine resins.

[0114] Examples of the allyl compound include triallyl isocyanurate compounds such as triallyl isocyanurate (TAIC), diallyl bisphenol compounds, and diallyl phthalate (DAP).

[0115] These curing agents may be used alone or in combination of two or more.

[0116] The weight average molecular weight (Mw) of the curing agent is not particularly limited, and is, for example, preferably 100 to 5000, more preferably 100 to 4000, and even more preferably 100 to 3000. When the weight average molecular weight (Mw) of the curing agent is within this range, a resin composition with superior heat resistance of the cured product can be obtained. The weight average molecular weight (Mw) of the curing agent is a value measured using gel permeation chromatography (GPC), a common molecular weight measurement method.

[0117] The average number of functional groups that contribute to the reaction during curing of the resin composition per molecule of curing agent (number of functional groups) varies depending on the weight-average molecular weight of the curing agent. From the viewpoints of the heat resistance of the cured product and the storage stability and flowability of the resin composition, the average number of functional groups is, for example, preferably 1 to 20, and more preferably 2 to 18.

[0118] The resin composition may contain a flame retardant. The inclusion of a flame retardant can enhance the flame retardancy of a cured product of the resin composition. The type of flame retardant is not particularly limited. Specifically, in fields where halogen-based flame retardants such as bromine-based flame retardants are used, flame retardants such as ethylene dipentabromobenzene, ethylene bistetrabromoimide, decabromodiphenyl oxide, tetradecabromodiphenoxybenzene, and bromostyrene-based compounds that react with polymerizable compounds, each having a melting point of 300°C or higher, are preferred in terms of preventing a decrease in heat resistance. Furthermore, in fields where halogen-free materials are required, phosphorus-containing flame retardants (phosphorus-based flame retardants) are preferably used. Examples of phosphorus-based flame retardants 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. Examples of phosphate ester-based flame retardants include condensed phosphate esters of dixylenyl phosphate. Examples of phosphazene flame retardants include phenoxyphosphazene. Examples of bisdiphenylphosphine oxide flame retardants include xylylenebisdiphenylphosphine oxide. Examples of phosphinate flame retardants include metal phosphinates of aluminum dialkylphosphinates. These flame retardants may be used alone or in combination of two or more.

[0119] [Physical Properties of Resin Composition] The cured product of the resin composition according to this embodiment preferably has a relative dielectric constant of 5.0 or more at a frequency of 10 GHz. Since the cured product of the resin composition has a relative dielectric constant of 5.0 or more at a frequency of 10 GHz, it is suitable for use in forming an insulating layer provided in a wiring board compatible with high frequencies.

[0120] The dielectric constant of the cured product of the resin composition at a frequency of 10 GHz is more preferably 5.5 or more, even more preferably 6.0 or more, and particularly preferably a value selected from the group consisting of 6.4, 6.8, 7.0, 7.3, 7.5, 8.0, and 8.4. The upper limit of the dielectric constant of the cured product of the resin composition at a frequency of 10 GHz is not particularly limited, but is, for example, 15.0 or less.

[0121] In order to obtain a relative dielectric constant within such a high range, as described above, it is necessary to adjust the total content of one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide to 50 mass% or more relative to the total amount of the inorganic filler (C), and to adjust the total content of the one or more fillers to 100 mass parts or more relative to 100 mass parts of the modified polyphenylene ether compound (A) and the maleimide compound (B).

[0122] [Uses of Resin Composition] The resin composition according to the present embodiment is mainly used for producing prepregs, as described below. In addition to prepregs, the resin composition is also used for forming resin layers provided in resin-coated metal foils and resin-coated films, and insulating layers provided in metal-clad laminates and wiring boards.

[0123] Furthermore, the resin composition according to this embodiment provides a cured product having a high dielectric constant and a low dielectric loss tangent. Therefore, the resin composition is suitable for use in forming an insulating layer provided on a high-frequency wiring board, such as a wiring board for an antenna or an antenna substrate for a millimeter-wave radar. That is, the resin composition according to this embodiment is suitable for use in manufacturing a high-frequency wiring board.

[0124] Examples of high-frequency compatible wiring boards include, but are not limited to, wiring boards with a small inter-wire distance (the distance between adjacent wires), wiring boards with a small wire width (the distance perpendicular to the longitudinal direction of the wires), and multi-layer wiring boards.

[0125] The wiring board may be a multilayer wiring board having four or more circuit layers, and the resin composition according to the present embodiment can be suitably used as an insulating material for the insulating layer of the multilayer wiring board. The resin composition according to the present embodiment can also be used in such a multilayer wiring board to achieve higher wiring density, faster signal transmission, and reduced signal transmission loss. Furthermore, even when applied to a multilayer wiring board having conductive through holes and / or vias, the resin composition can achieve faster signal transmission and reduced signal transmission loss.

[0126] [Method for Preparing Resin Composition] The method for preparing the resin composition according to this embodiment is not particularly limited, and the resin composition can be prepared by any method known to those skilled in the art. Examples of methods for preparing the resin composition include a method in which the modified polyphenylene ether compound (A), the maleimide compound (B), and other optional components are mixed in an appropriate blending ratio, and then an inorganic filler (C) containing a titanic acid compound filler (C-1) is added. Specifically, when a varnish-like composition containing an organic solvent is obtained, the method described below in the description of the prepreg can be used.

[0127] <Prepreg, metal-clad laminate, wiring board, resin-coated metal foil, and resin-coated film> Next, a prepreg for wiring boards, a metal-clad laminate, a wiring board, a resin-coated metal foil, and a resin-coated film using the resin composition according to the above-described embodiment will be described.

[0128] [Prepreg] Fig. 1 is a schematic cross-sectional view showing an example of a prepreg according to an embodiment of the present invention. In Fig. 1, the respective reference numerals represent a prepreg 1, a resin composition or a semi-cured resin composition 2, and a fibrous base material 3, respectively.

[0129] As shown in Fig. 1, the prepreg 1 comprises a resin composition or a semi-cured product of the resin composition 2, and a fibrous base material 3. Specifically, the prepreg 1 comprises the resin composition or the 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.

[0130] As used herein, the term "semi-cured product" refers to a resin composition that has been cured to the extent that it can be further cured. In other words, the semi-cured product 2 is a resin composition that has been semi-cured (B-staged). Specifically, when the resin composition is heated, the viscosity initially gradually decreases. Then, the resin composition begins to harden, and the viscosity of the composition gradually increases. In this case, the semi-cured product 2 refers to a resin composition in a state between when the viscosity starts to increase and when the resin composition is completely hardened.

[0131] The prepreg 1 obtained using the resin composition according to the above-described embodiment may comprise a semi-cured resin composition 2 as described above, or may comprise the resin composition itself in an uncured state. That is, the prepreg 1 according to this embodiment may comprise a semi-cured resin composition 2 (a B-stage resin composition) and a fibrous base material 3, or may comprise a resin composition before curing (an A-stage resin composition) and a fibrous base material 3. The resin composition or the semi-cured resin composition 2 may be obtained by heating and / or drying the resin composition according to the above-described embodiment.

[0132] The resin composition according to the embodiment described above is often prepared in a varnish form and used as a resin varnish when producing the prepreg 1, a resin-coated film, a resin-coated metal foil, etc. Such a resin varnish can be prepared, for example, by the method described below.

[0133] First, each component soluble in an organic solvent, such as a resin component and a reaction initiator, is added to an organic solvent and dissolved therein. At this time, the mixed solution may be heated as needed. Then, an inorganic filler or other component insoluble in an organic solvent is added to the mixed solution, 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. As a result, a varnish-like resin composition is prepared. The organic solvent that can be used is not particularly limited as long as it dissolves the modified polyphenylene ether compound (A), the maleimide compound (B), and the curing agent, etc., added as needed, and does not inhibit the curing reaction. Examples of organic solvents include toluene, methyl ethyl ketone, cyclohexanone, cyclopentanone, methylcyclohexane, dimethylformamide, and propylene glycol monomethyl ether acetate. These organic solvents may be used alone or in combination of two or more.

[0134] Examples of a method for producing the prepreg 1 using a resin composition in the form of a varnish include a method in which the resin composition in the form of a resin varnish is impregnated into the fibrous base material 3 and then dried.

[0135] Examples of the fibrous substrate 3 used in producing the prepreg 1 include glass cloth, aramid cloth, polyester cloth, LCP (liquid crystal polymer) nonwoven fabric, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. Among these, using glass cloth as the fibrous substrate 3 results in a laminate with excellent mechanical strength. In particular, the glass cloth is preferably flattened glass cloth. Specifically, the type of glass cloth is not particularly limited, but examples include low-dielectric-constant glass cloths such as E-glass, S-glass, NE-glass, Q-glass, and L-glass. The flattening process can be performed, for example, by continuously pressing the glass cloth with a press roll at an appropriate pressure to compress the yarns flat. The thickness of the fibrous substrate 3 is not particularly limited and can be a common thickness of, for example, 0.08 mm to 0.3 mm.

[0136] The resin varnish (resin composition) can be impregnated into the fibrous substrate 3 by immersion and / or coating. This impregnation can be repeated multiple times as necessary. In this case, by repeating the impregnation using multiple resin varnishes with different compositions and / or concentrations, the desired composition (content ratio) and / or resin amount can be finally adjusted.

[0137] The fibrous substrate 3 impregnated with the resin varnish (resin composition) is heated under desired heating conditions, for example, at a temperature of 40° C. to 180° C. for about 1 minute to 10 minutes. By volatilizing the solvent from the varnish by heating, the amount of solvent is reduced or removed, and a prepreg 1 in an uncured state (A-stage resin composition) or a semi-cured state (B-stage resin composition) can be obtained.

[0138] [Metal-clad laminate] Fig. 2 is a schematic cross-sectional view showing an example of a metal-clad laminate according to an embodiment of the present invention. In Fig. 2, the reference numerals indicate a metal-clad laminate 11, an insulating layer 12, and a metal foil 13, respectively.

[0139] As shown in FIG. 2, the metal-clad laminate 11 includes an insulating layer 12 containing a cured product of the resin composition according to the above-described embodiment or a cured product of the prepreg 1 described above, and a metal foil 13.

[0140] The metal foil 13 is not particularly limited, and any metal foil known to those skilled in the art and generally used in metal-clad laminates 11, wiring boards, etc. Examples of the metal foil 13 include copper foil and aluminum foil.

[0141] The thickness of the metal foil 13 may be appropriately set depending on the desired purpose. For example, the thickness of the metal foil 13 may be set to approximately 0.2 μm to 70 μm. For example, when the thickness of the metal foil 13 is 10 μm or less, the metal foil 13 may be a copper foil with a carrier, which includes a release layer and a carrier, in order to improve handling properties.

[0142] The method for producing the metal-clad laminate 11 is not particularly limited, but for example, it can be produced using not only the prepreg 1 described above, but also a resin-coated metal foil and / or a resin-coated film described below.

[0143] Specifically, prepreg 1 and one or more layers of resin-coated metal foil and / or resin-coated film (described below) are stacked together, and then metal foil 13 such as copper foil is stacked on both or one of the top and bottom surfaces of the prepreg 1 and then heated and pressurized to form an integrated laminate. As a result, a double-sided or single-sided metal foil laminate can be produced. The conditions for the heated and pressurized molding can be appropriately set depending on the thickness of the laminate to be produced, the type of resin composition, and other factors. For example, the heated and pressurized molding conditions can be 170°C to 230°C, 1.5 MPa to 5.0 MPa, and 60 to 150 minutes.

[0144] The metal-clad laminate 11 may also be produced without using the prepreg 1, the resin-coated metal foil and / or the resin-coated film described below. For example, the resin varnish described above may be applied to the metal foil 13 by coating or the like, forming a layer containing a resin composition on the metal foil 13, and then heating and pressing the resulting metal-clad laminate 11. The coating or other application may be repeated multiple times as needed. In this case, it is also possible to adjust the composition (content ratio) and resin amount by repeatedly applying coating or the like using multiple resin varnishes with different compositions and concentrations, thereby producing a metal-clad laminate 11 having the desired composition (content ratio) and resin amount.

[0145] [Wiring Board] Fig. 3 is a schematic cross-sectional view showing an example of a wiring board according to an embodiment of the present invention. In Fig. 3, the reference numerals indicate an insulating layer 12, a wiring 14, and a wiring board 21, respectively.

[0146] As shown in FIG. 3, wiring board 21 includes insulating layer 12 containing a cured product of the resin composition according to the above-described embodiment or a cured product of prepreg 1 described above, and wiring 14 provided on insulating layer 12.

[0147] The method for manufacturing wiring board 21 is not particularly limited, but examples thereof include a method of forming a circuit by etching metal foil 13 on the surface of metal-clad laminate 11 to obtain wiring board 21 having a conductor pattern (wiring 14) as a circuit on the surface of the laminate. In addition to this method, examples of the circuit formation method include a semi-additive process (SAP) and a modified semi-additive process (MSAP).

[0148] [Resin-Coated Metal Foil] 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. In Fig. 4, the reference numerals indicate a metal foil 13, a resin-coated metal foil 31, and a resin layer 32, respectively.

[0149] 4, the resin-coated metal foil 31 according to this embodiment has a configuration in which a resin layer 32 containing the resin composition according to the above-described embodiment or a semi-cured product 2 of the resin composition is laminated with a metal foil 13. That is, the resin-coated metal foil 31 may include a resin layer 32 containing the resin composition before curing (a resin composition in an A-stage) and the metal foil 13, or may include a resin layer 32 containing a semi-cured product 2 of the resin composition (a resin composition in a B-stage) and the metal foil 13. The metal foil 13 is the same as the metal foil 13 of the metal-clad laminate 11 described above.

[0150] 4 , the resin-coated metal foil 31 can be produced, for example, by the following method. For example, the resin varnish described above is first applied to the surface of the metal foil 13, such as a copper foil, and then the varnish is heated and dried to volatilize the solvent. The solvent is then reduced or removed, thereby producing the resin-coated metal foil 31.

[0151] Examples of application methods include a bar coater, comma coater, die coater, roll coater, and gravure coater. The heating and drying conditions may be set as desired and are not particularly limited. For example, heating may be performed at a temperature of 50°C to 180°C for approximately 0.1 to 10 minutes. The conditions may be set so that the resin-coated metal foil 31 is obtained in a pre-cured state (A-stage resin composition) or semi-cured state (B-stage resin composition) after heating and drying. The application may be repeated multiple times as needed. Furthermore, by repeatedly applying the coating or the like using multiple resin varnishes with different compositions and concentrations, the composition (content ratio) and resin amount can be adjusted, and ultimately a resin-coated metal foil 31 having the desired composition (content ratio) and resin amount can be obtained.

[0152] The resin-coated metal foil 31 may be provided with a cover film or the like as needed. By providing a cover film, it is possible to prevent foreign matter from being mixed into the resin composition in a semi-cured state or the like. The cover film is not particularly limited as long as it can be peeled off without damaging the shape of the resin composition. Examples of the cover film that can be used include polyolefin film, polyester film, TPX film, films formed by providing a release agent layer on these films, and paper formed by laminating these films onto a paper substrate.

[0153] [Resin-Coated Film] Fig. 5 is a schematic cross-sectional view showing an example of a resin-coated film according to an embodiment of the present invention. In Fig. 5, the reference numerals indicate a resin-coated film 41, a resin layer 42, and a film support substrate 43, respectively.

[0154] 5 , the resin-coated film 41 has a configuration in which a resin layer 42 containing the resin composition according to the above-described embodiment or a semi-cured product 2 of the resin composition is laminated with a film support substrate 43. That is, the resin-coated film 41 may include a resin layer 42 containing the resin composition before curing (A-stage resin composition) and a film support substrate 43, or may include a resin layer 42 containing a semi-cured product 2 of the resin composition (B-stage resin composition) and a film support substrate 43. Furthermore, the resin layer 42 only needs to include the resin composition according to the above-described embodiment or a semi-cured product 2 of the resin composition, and may also include a fibrous base material 3.

[0155] 5 , the resin-coated film 41 can be produced, for example, by the following method. For example, first, the resin varnish described above is applied to the surface of the film support substrate 43, and then the applied resin varnish is dried by heating. Thereafter, the solvent is volatilized from the varnish to reduce or remove the solvent, thereby producing the resin-coated film 41.

[0156] The application method and heating and drying conditions are the same as those in the manufacturing method of the resin-coated metal foil 31 described above, and should be set so as to ultimately obtain the resin-coated metal foil 31 in a pre-cured state (A-stage resin composition) or semi-cured state (B-stage resin composition).

[0157] There are no particular limitations on the film support substrate 43, as long as it is any substrate known to those skilled in the art. Examples of the film support substrate 43 include electrically insulating films such as polyimide films, PET (polyethylene terephthalate) films, polyester films, polyparabanic acid films, polyether ether ketone films, polyphenylene sulfide films, aramid films, polycarbonate films, and polyarylate films.

[0158] The resin-coated film 41 may also be provided with a cover film or the like, similar to the resin-coated metal foil 31 described above.

[0159] As described above, the prepreg, resin-coated metal foil, resin-coated film, and metal-clad laminate according to this embodiment are manufactured using the resin composition according to the above-described embodiment, which has a high dielectric constant and a low dielectric loss tangent when cured, and are therefore suitable for use in forming insulating layers in high-frequency wiring boards, as described above.

[0160] As described above, this specification discloses various aspects of the technology, the main aspects of which are summarized below.

[0161] A resin composition according to a first aspect of the present invention is a resin composition comprising: a polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond; a maleimide compound (B) having two or more N-substituted maleimide groups in one molecule; and an inorganic filler (C) including a titanate compound filler (C-1), wherein the titanate compound filler (C-1) comprises one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide, and the total content of the one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide is 50% by mass or more relative to the total amount of the inorganic filler (C), and is 100 parts by mass or more and 400 parts by mass or less relative to 100 parts by mass of the polyphenylene ether compound (A) and the maleimide compound (B).

[0162] A resin composition according to a second aspect of the present invention is the resin composition according to the first aspect, wherein the polyphenylene ether compound (A) comprises a modified polyphenylene ether compound having at least one of a weight average molecular weight and a number average molecular weight of 1,000 to 5,000.

[0163] A resin composition according to a third aspect of the present invention is the resin composition according to the first or second aspect, wherein the polyphenylene ether compound (A) comprises a polyphenylene ether compound having at least one group selected from the group represented by the above formula (1) and the group represented by the above formula (2).

[0164] A resin composition according to a fourth aspect of the present invention is the resin composition according to any one of the first to third aspects, wherein the functional group equivalent of the maleimide compound (B) is 200 g / eq. to 1000 g / eq.

[0165] A resin composition according to a fifth aspect of the present invention is the resin composition according to any one of the first to fourth aspects, wherein the mass ratio of the polyphenylene ether compound (A) to the maleimide compound (B) (the polyphenylene ether compound (A):the maleimide compound (B)) is 20:80 to 80:20.

[0166] A resin composition according to a sixth aspect of the present invention is the resin composition according to any one of the first to fifth aspects, wherein the inorganic filler (C) further contains another filler (C-2) different from the titanate compound filler (C-1).

[0167] A resin composition according to a seventh aspect of the present invention is the resin composition according to any one of the first to sixth aspects, wherein a cured product of the resin composition has a relative dielectric constant of 5.0 or more at a frequency of 10 GHz.

[0168] A prepreg according to an eighth aspect of the present invention comprises the resin composition according to any one of the first to seventh aspects or a semi-cured product of the resin composition, and a fibrous base material.

[0169] A resin-coated film according to a ninth aspect of the present invention comprises a resin layer containing the resin composition according to any one of the first to seventh aspects or a semi-cured product of the resin composition, and a support film.

[0170] A resin-coated metal foil according to a tenth aspect of the present invention comprises a resin layer containing the resin composition according to any one of the first to seventh aspects or a semi-cured product of the resin composition, and a metal foil.

[0171] A metal-clad laminate according to an eleventh aspect of the present invention comprises an insulating layer containing a cured product of the resin composition according to any one of the first to seventh aspects, and a metal foil.

[0172] A metal-clad laminate according to a twelfth aspect of the present invention comprises an insulating layer containing a cured product of the prepreg according to the eighth aspect, and a metal foil.

[0173] A wiring board according to a thirteenth aspect of the present invention comprises an insulating layer containing a cured product of the resin composition according to any one of the first to seventh aspects, and wiring.

[0174] A wiring board according to a fourteenth aspect of the present invention comprises an insulating layer containing a cured product of the prepreg according to the eighth aspect, and wiring.

[0175] The present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0176] First, the raw materials used in preparing the resin compositions in the present examples are summarized below.

[0177] [Modified Polyphenylene Ether Compound (A)] Modified PPE Compound 1: Polyphenylene ether compound having a vinylbenzyl group (ethenylbenzyl group) at the terminal ("OPE-2st 1200" manufactured by Mitsubishi Gas Chemical Company, Inc., Mn 1200, Mw 1600, represented by the above formula (10), in which Ar in formula (10) is a phenylene group, and R １ ~R ３ is a hydrogen atom and p is 1) Modified PPE compound 2: 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)

[0178] Specifically, the modified PPE compound 2 was obtained by the following synthesis method. First, 200 g of polyphenylene ether (SA90 manufactured by SABIC Innovative Plastics, two 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, a stirrer, a cooling device, and a dropping funnel, and the mixture was stirred. The mixture was then gradually heated until the liquid temperature reached 75°C. Then, an aqueous sodium hydroxide solution (20 g sodium hydroxide / 20 g water) was added dropwise to the solution over 20 minutes as an alkali metal hydroxide. The mixture was then stirred at 75°C for another 4 hours. Next, the contents of the flask were neutralized with 10% by mass hydrochloric acid, and a large amount of methanol was added. This caused a precipitate to form in the liquid within the flask. In other words, the product contained in the reaction solution within the flask was reprecipitated. The precipitate was then filtered out, washed three times with a mixture of methanol and water in a mass ratio of 80:20, and then dried under reduced pressure at 80°C for 3 hours.

[0179] The obtained solid is １ H-NMR (400MHz, CDCl ３ , 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 a substituent at the molecular end. Specifically, it was confirmed that it was an ethenylbenzylated polyphenylene ether. This obtained modified polyphenylene ether compound is represented by the above formula (11), in which Y in formula (11) is a dimethylmethylene group (represented by the above formula (9), in which R ３３ and R ３４is a methyl group), Ar is a phenylene group, and R １ ~R ３ was a hydrogen atom and p was 1.

[0180] The number of terminal functional groups of the modified polyphenylene ether was measured as follows.

[0181] 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.

[0182] Residual OH content (µmol / g) = [(25 x Abs) / (ε x OPL x X)] x 10 (where ε is the extinction coefficient and is 4700 L / mol cm, and OPL is the cell optical path length and is 1 cm).

[0183] 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 from the number of terminal hydroxyl groups of 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.

[0184] 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 by using a viscometer (AVS500 Visco System manufactured by Schott) to measure a 0.18 g / 45 ml methylene chloride solution (liquid temperature 25° C.). As a result, the intrinsic viscosity (IV) of the modified polyphenylene ether was 0.086 dl / g.

[0185] The molecular weight distribution of the modified polyphenylene ether was measured using GPC. The weight average molecular weight (Mw) was calculated from the molecular weight distribution. The Mw was found to be 1,900.

[0186] Modified PPE compound 3: a modified polyphenylene ether compound in which the terminal hydroxyl groups of polyphenylene ether are modified with methacryloyl groups (SA9000 manufactured by SABIC Innovative Plastics, weight average molecular weight Mw 2000, number of terminal functional groups 2)

[0187] [Maleimide Compound (B)] Maleimide Compound 1: A maleimide compound represented by the following formula (18) ("BMI-80" manufactured by K.I. Chemical Co., Ltd., maleimide functional group equivalent: 285 g / eq., molecular weight: 570.6)

[0188]

[0189] Maleimide compound 2: a maleimide compound represented by the above formula (16) ("BMI-689" manufactured by Designer Molecules Inc., maleimide functional group equivalent weight: 344.5 g / eq., molecular weight: 689); Maleimide compound 3: a maleimide compound represented by the above formula (13) ("MIR-5000" manufactured by Nippon Kayaku Co., Ltd., maleimide functional group equivalent weight: 260 g / eq.); Maleimide compound 4: polyphenylmethane maleimide ("BMI-2300" manufactured by Daiwa Kasei Kogyo Co., Ltd., maleimide functional group equivalent weight: 180 g / eq., molecular weight: 400);

[0190] [Inorganic Filler (C)] (Titanium Acid Compound Filler (C-1)) Strontium titanate particles: "ST-H100" (specific gravity 5.1 g / cm) manufactured by Kyoritsu Material Co., Ltd. ３ Calcium titanate particles: "CT" manufactured by Fuji Titanium Industry Co., Ltd. (specific gravity 4 g / cm ３ , average particle size (D50) 1.9 μm) Barium titanate particles: barium titanate "BT-HP500" manufactured by Kyoritsu Material Co., Ltd. (specific gravity 6.08 g / cm ３ , average particle size (D50) 1.00 μm)

[0191] (Other fillers (C-2)) Silica filler: "SC2300-SVJ" (specific gravity 2.3 g / cm) manufactured by Admatechs Co., Ltd. ３ , average particle size (D50) 0.5 μm)

[0192] [Reaction initiator (D)] Peroxide: α,α'-bis(t-butylperoxy-m-isopropyl)benzene ("Perbutyl P" (PBP) manufactured by NOF Corporation)

[0193] [Silane Coupling Agent (E)] 3-Methacryloxypropyltrimethoxysilane (a silane coupling agent having a methacryl group in the molecule, "KBM-503" manufactured by Shin-Etsu Chemical Co., Ltd.)

[0194] Next, the method for preparing the resin composition (varnish) in each example and each comparative example, and the method for producing evaluation substrate (metal-clad laminate) 1 and evaluation substrate (metal-clad laminate) 2 will be described below.

[0195] Examples 1 to 8 and Comparative Examples 1 to 4 (Method of Preparing Resin Composition (Varnish)) In each Example and Comparative Example, all components other than the inorganic filler, reaction initiator, and silane coupling agent were added to methyl ethyl ketone and mixed to a solids concentration of 40% by mass in the formulation (parts by mass) shown in Tables 1 to 3 below. The resulting mixture was then heated at 65°C and further stirred for 60 minutes. The resulting mixture was then cooled to 25°C with stirring, and the inorganic filler, reaction initiator, and silane coupling agent were added in the formulation (parts by mass) shown in Tables 1 to 3 below, and the inorganic filler was dispersed in the mixture using a bead mill. After dispersion, a varnish-like resin composition was obtained.

[0196] (Method of producing evaluation substrate (metal-clad laminate) 1) A fibrous substrate (glass cloth: #1067 type, NE glass, manufactured by Nitto Boseki Co., Ltd.) was impregnated with the varnish obtained by the method described above, and then heated and dried at 120°C to 150°C for 3 minutes to produce prepreg 1. The thickness of one prepreg after curing was adjusted to 0.070 mm.

[0197] Twelve sheets of the resulting prepreg were stacked, and copper foil ("GTHMP12" manufactured by Furukawa Electric Co., Ltd., 12 μm thick) was placed on both sides. This was used as a pressure body, and heated to 210 °C at a temperature increase rate of 3 °C / min, and then heated and pressed at 210 °C for 120 minutes under a pressure of 4 MPa. Finally, an evaluation substrate (metal-clad laminate) 1 with a thickness of approximately 0.84 mm and copper foil bonded to both sides was obtained.

[0198] (Method of producing evaluation substrate (metal-clad laminate) 2) The varnish obtained by the method described above was impregnated into a fibrous substrate (glass cloth: #1067 type, NE glass, manufactured by Nitto Boseki Co., Ltd.), and then heated and dried at 120°C to 150°C for 3 minutes to produce prepreg 2. The thickness of one prepreg after curing was adjusted to 0.100 mm.

[0199] Copper foil ("3EC-VLP" manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 12 μm) was placed on both sides of one of the obtained prepregs. This was used as a pressure body, and was heated to a temperature of 210 ° C at a temperature increase rate of 3 ° C / min, and heated and pressed at 210 ° C for 120 minutes under a pressure of 4 MPa. Finally, an evaluation substrate (metal-clad laminate) 2 with a thickness of approximately 0.100 mm and copper foil bonded to both sides was obtained.

[0200] First, the following tests were carried out using the prepregs 1 and evaluation substrates 1 of the examples and comparative examples obtained by the above-described method.

[0201] <Evaluation Test 1> [Dielectric Properties (Dielectric Constant and Dielectric Loss Tangent)] An unclad board (cured prepreg) was prepared by etching the copper foil off of the approximately 0.84 mm thick evaluation board (copper-clad laminate) 1 obtained by the method described above. A 2 mm wide, 100 mm long specimen was cut out for evaluation. The specimen was dried for 2 hours in a thermostatic chamber maintained at 105°C and then allowed to cool in a desiccator. The dielectric constant Dk and dielectric loss tangent Df of the specimen at 10 GHz were measured using a cavity resonator perturbation method. Specifically, the dielectric constant Dk and dielectric loss tangent Df of the specimen at 10 GHz at 25°C were measured using a network analyzer (Keysight Technologies, Inc., N5230A). When the dielectric constant Dk was 5.0 or higher, the specimen was evaluated as having a high dielectric constant Dk and a "pass" rating. Furthermore, when the dielectric loss tangent Df was 0.005 or less, the dielectric loss tangent Df of the test piece was low and the test piece was evaluated as "passed."

[0202] [Moldability] A grid-patterned conductor wiring was formed on both sides of the copper foil layer of a copper-clad laminate (manufactured by Panasonic Industries Co., Ltd., product number "R-5775", thickness 0.2 mm, copper foil 35 μm) so that the residual copper ratio was 20% or 50%. Furthermore, one prepreg 1 obtained by the above-mentioned method was laminated on each side of the conductor wiring of the substrate, and a 12 μm thick copper foil ("3EC-VLP" manufactured by Mitsui Mining & Smelting Co., Ltd.) was further placed on top of it to form a pressure body. The laminate was heated and pressed for 120 minutes at a temperature of 210 ° C. and a pressure of 4 MPa to obtain a laminate. Thereafter, the copper foil of the outer layer was entirely etched to obtain a laminate sample. In this laminate sample (evaluation laminate), the resin composition derived from prepreg 1 was sufficiently infiltrated between the grid-patterned circuits with a residual copper ratio of 20% and 50%, and if no voids were formed, the moldability was evaluated as "pass". When the resin composition derived from prepreg 1 sufficiently penetrated between the grid pattern circuits with a copper residual ratio of 50%, but did not sufficiently penetrate between the grid pattern circuits with a copper residual ratio of 20%, resulting in the formation of voids, the moldability was evaluated as "good." When the resin composition derived from prepreg 1 did not sufficiently penetrate between the grid pattern circuits with either a copper residual ratio of 20% or 50%, resulting in the formation of voids, the moldability was evaluated as "fail." The voids were visually confirmed.

[0203] The results of Evaluation Test 1 for each Example and Comparative Example are summarized in Tables 1 to 3 below, along with the blending compositions. The blending amounts are shown in parts by mass per 100 parts by mass of the resin component. Note that the "-" in the columns in Tables 1 to 3 below means that the component was not blended in the resin composition of that Example or Comparative Example.

[0204]

[0205]

[0206]

[0207] <Discussion> As shown in Tables 1 and 2 above, the resin compositions of Examples 1 to 12 contain a polyphenylene ether compound (A), a maleimide compound (B), and strontium titanate particles or calcium titanate particles as an inorganic filler (C). Furthermore, in the resin compositions of Examples 1 to 12, the content of the strontium titanate particles or calcium titanate particles is 50% by mass or more relative to the total amount of the inorganic filler (C), and is 100 to 400 parts by mass per 100 parts by mass of the resin component. The cured products of these resin compositions were evaluated as "pass" for both the relative dielectric constant Dk and the dielectric loss tangent Df. Furthermore, the moldability was also evaluated as "pass" or "good."

[0208] On the other hand, the resin composition of Comparative Example 1 had a low dielectric constant Dk because the content of strontium titanate particles as inorganic filler (C) was less than 100 parts by mass per 100 parts by mass of the resin component.

[0209] The resin compositions of Comparative Examples 2 and 3 did not contain either strontium titanate particles or calcium titanate particles as the inorganic filler (C), which is thought to have resulted in a low dielectric constant Dk. In Comparative Example 3, the amount of silica filler relative to 100 parts by mass of the resin component was too high, which is thought to have affected moldability.

[0210] It is believed that the resin composition of Comparative Example 4 had a low relative dielectric constant Dk because the content of strontium titanate particles as the inorganic filler (C) was less than 50 mass % relative to the total amount of the inorganic filler (C).

[0211] The resin compositions of Comparative Examples 5 and 6 contain titanate compound filler (C) as the inorganic filler (C), but since they contain only barium titanate particles other than strontium particles, calcium titanate particles, and titanium oxide particles, it is believed that the dielectric dissipation factor Df was high.

[0212] Furthermore, the following tests were carried out using the evaluation boards 2 of Examples 1 to 12.

[0213] <Evaluation Test 2>

[0214] [Glass Transition Temperature] An unclad board (cured prepreg) was prepared by etching the copper foil off the approximately 0.100 mm thick evaluation substrate (copper-clad laminate) 2 obtained by the method described above. The glass transition temperature of the test piece (cured resin composition) was measured using a Seiko Instruments Inc. viscoelasticity spectrometer "DMS6100." Dynamic mechanical analysis (DMA) was performed using a tensile module at a frequency of 10 Hz. The temperature at which tan δ reached a maximum when the temperature was increased from room temperature to 340°C at a heating rate of 5°C / min was taken as the glass transition temperature (°C). If the measured glass transition temperature was 200°C or higher, the test piece was evaluated as having a sufficiently high glass transition temperature.

[0215] [Thermal Expansion Coefficient] Test specimens were prepared by etching away the copper foil from the approximately 0.100 mm-thick evaluation substrate (copper-clad laminate) 2 obtained by the method described above. The thermal expansion coefficient in the substrate surface direction (tensile direction or glass cloth warp direction) at temperatures below the glass transition temperature of the cured resin was measured by the TMA (Thermo-mechanical analysis) method. Measurements were performed using a TMA device ("TMA6000" manufactured by SII Nanotechnology Inc.) in tensile mode. To eliminate the effects of thermal distortion of the test specimen during pressure-boosting, the heating-cooling cycle was repeated twice, and the average thermal expansion coefficient from 50°C to 100°C on the second temperature displacement chart was measured. Note that a smaller measured value indicates a lower, more preferable thermal expansion coefficient. A measured thermal expansion coefficient of 15 or less was evaluated as being sufficiently low. The unit is "ppm / °C." The measurement conditions are as follows: Measurement conditions: Temperature rise range in the first cycle: 30°C to glass transition temperature + 20°C Temperature rise range in the second cycle: 30°C to 300°C Temperature rise rate: 10°C / min, load: 1 g Test piece: 3.5 mm (width), 20 mm (tensile direction)

[0216] The results of Evaluation Test 2 for each example are summarized in Tables 4 and 5 below, along with the formulation. The amounts are shown in parts by mass relative to 100 parts by mass of the resin component. Note that the "-" in the columns of Tables 4 and 5 below means that the component was not blended into the resin composition of that example.

[0217]

[0218]

[0219] <Discussion> As shown in Tables 4 and 5 above, it was found that evaluation substrate 1 or evaluation substrate 2, which used the resin compositions of Examples 1 to 12, all had a sufficiently high glass transition temperature and a sufficiently low expansion coefficient.

[0220] This application is based on Japanese Patent Application No. 2024-054557, filed on March 28, 2024, the contents of which are incorporated herein by reference.

[0221] The embodiments and examples disclosed herein should be understood to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims.

[0222] According to the present invention, a resin composition can be provided that can give a cured product having a high dielectric constant and a low dielectric loss tangent, and therefore the resin composition can be suitably used to form an insulating layer or the like provided on a wiring board for an antenna, an antenna substrate for a millimeter-wave radar, or other high-frequency wiring board.

Claims

1. A resin composition comprising a polyphenylene ether compound (A) having a carbon-carbon unsaturated double bond, a maleimide compound (B) having two or more N-substituted maleimide groups in one molecule, and an inorganic filler (C) including a titanate compound filler (C-1), wherein the titanate compound filler (C-1) contains one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide, and the total content of the one or more fillers selected from the group consisting of strontium titanate, calcium titanate, and titanium oxide is 50 mass% or more based on the total amount of the inorganic filler (C), and is 100 parts by mass or more and 400 parts by mass or less based on 100 parts by mass of the polyphenylene ether compound (A) and the maleimide compound (B).

2. The resin composition according to claim 1, wherein the polyphenylene ether compound (A) comprises a modified polyphenylene ether compound having at least one of a weight average molecular weight and a number average molecular weight of 1,000 to 5,000.

3. The resin composition according to claim 1, wherein the polyphenylene ether compound (A) comprises a polyphenylene ether compound having at least one group selected from a group represented by the following formula (1) and a group represented by the following formula (2): [In formula (1), p represents an integer of 0 to 10, Ar represents an arylene group, and R １ ~R ３ each independently represents a hydrogen atom or an alkyl group. [In formula (2), R ４ represents a hydrogen atom or an alkyl group.

4. The resin composition according to claim 1, wherein the maleimide compound (B) has a functional group equivalent of 200 g / eq. to 1000 g / eq.

5. The resin composition according to claim 1, wherein the mass ratio of the polyphenylene ether compound (A) to the maleimide compound (B) (the polyphenylene ether compound (A):the maleimide compound (B)) is 20:80 to 80:

20.

6. The resin composition according to claim 1, wherein the inorganic filler (C) further contains another filler (C-2) different from the titanate compound filler (C-1).

7. The resin composition according to claim 1, wherein the cured product of said resin composition has a relative dielectric constant of 5.0 or more at a frequency of 10 GHz.

8. A prepreg comprising the resin composition according to any one of claims 1 to 7 or a semi-cured product of said resin composition and a fibrous base material.

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

10. A resin-coated metal foil comprising a resin layer containing the resin composition according to any one of claims 1 to 7 or a semi-cured product of said resin composition, and a metal foil.

11. A metal-clad laminate comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 7 and a metal foil.

12. A metal-clad laminate comprising an insulating layer containing a cured product of the prepreg according to claim 8 and a metal foil.

13. A wiring board comprising an insulating layer containing a cured product of the resin composition according to any one of claims 1 to 7 and wiring.

14. A wiring board comprising an insulating layer containing a cured product of the prepreg according to claim 8 and wiring.

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