JP7351434B2 - Thermosetting resin composition, dielectric substrate, and microstrip antenna - Google Patents

Description

The present invention relates to a thermosetting resin composition, a dielectric substrate made of the thermosetting resin composition, and a microstrip antenna equipped with the dielectric substrate.

In recent years, wireless communication has become faster, and there is a demand for higher performance and smaller size of the communication equipment used. Furthermore, in recent years, the capacity of wireless communication has increased rapidly, and as a result, the frequencies used for transmission signals are rapidly becoming wider and higher in frequency. For this reason, the frequency band used by communication equipment cannot be supported by the conventional microwave band alone, and is being expanded to include the millimeter wave band. Against this background, there is a strong demand for higher performance antennas installed in communication equipment.

Communication equipment can be further miniaturized if the dielectric constant of the antenna material (dielectric substrate) built into the communication equipment increases. Furthermore, when the dielectric loss tangent of the dielectric substrate becomes smaller, the loss becomes lower, which is advantageous for higher frequencies. Therefore, if a dielectric substrate with a high dielectric constant and a small dielectric loss tangent can be used, it is possible to achieve higher frequencies, thereby shortening the circuit length and downsizing the communication equipment.

Patent Document 1 describes a laminate of a dielectric substrate made of a composite material containing a fluororesin and a glass cloth, and an antenna whose surface in contact with the fluororesin has a two-dimensional roughness Ra of less than 0.2 μm. An antenna having a substrate is disclosed. This document describes the dielectric constant and dielectric loss tangent of a circuit board measured at 1 GHz.

Patent Document 2 discloses a resin composition that includes a siloxane-modified polyamideimide resin, a high dielectric constant filler, and an epoxy resin, and has a cured product having a dielectric constant of 15 or more at 25° C. and 1 MHz. Examples of this document describe an example in which barium titanate is used as the high dielectric constant filler.

Patent Document 3 discloses a resin composition containing an epoxy resin, a dielectric powder, a nonionic surfactant, and an active ester curing agent. This document states that this resin composition can be used as a high dielectric constant insulating material for electronic components used in a high frequency region and a high dielectric constant insulating material for fingerprint sensors. The example of this document describes an example in which barium titanate is used as the dielectric powder.

Patent Document 4 includes an epoxy resin, a curing agent, and an inorganic filler containing predetermined amounts of calcium titanate particles and strontium titanate particles, the inorganic filler consisting of silica particles and alumina particles. Disclosed is a molding resin composition which further contains at least one member selected from the group consisting of:

JP 2018-41998 Publication Japanese Patent Application Publication No. 2004-315653 JP 2020-105523 Publication Patent No. 6870778

However, the dielectric substrates described in Patent Documents 1 to 4 have problems with dielectric properties such as high dielectric constant and low dielectric loss tangent, and these problems are particularly noticeable in high frequency bands.

The present inventors have discovered that a dielectric substrate with excellent dielectric properties can be obtained by including a specific high dielectric constant filler, and have completed the first to fourth inventions.
That is, the first to fourth inventions can be shown below.

（一般式（１）中、Ａは、脂肪族環状炭化水素基を介して連結された置換または非置換のアリーレン基であり、Ａｒ’は、置換または非置換のアリール基であり、
Ｂは、下記一般式（Ｂ）で表される構造であり、

（一般式（Ｂ）中、Ａｒは、置換または非置換のアリーレン基であり、Ｙは、単結合、置換または非置換の炭素原子数１～６の直鎖のアルキレン基、または置換または非置換の炭素原子数３～６の環式のアルキレン基、置換または非置換の２価の芳香族炭化水素基、エーテル結合、カルボニル基、カルボニルオキシ基、スルフィド基、あるいはスルホン基である。ｎは０～４の整数である。）
ｋは、繰り返し単位の平均値であり、０．２５～３．５の範囲である。）
［５］ さらに硬化触媒（Ｄ）を含む、［１］～［４］のいずれかに記載の熱硬化性樹脂組成物。
［６］ 前記樹脂組成物のスパイラルフローの流動長が５０ｃｍ以上である、［１］～［５］のいずれかに記載の熱硬化性樹脂組成物。
［７］ 下記条件で測定された矩形圧が０．１ＭＰａ以上である、［１］～［６］のいずれかに記載の熱硬化性樹脂組成物。
（条件）
低圧トランスファー成形機を用いて、金型温度１７５℃、注入速度１７７ｍｍ^３／秒の条件にて、幅１３ｍｍ、厚さ１ｍｍ、長さ１７５ｍｍの矩形状の流路に樹脂組成物を注入し、流路の上流先端から２５ｍｍの位置に埋設した圧力センサーにて圧力の経時変化を測定し、前記樹脂組成物の流動時における最低圧力を算出して、この最低圧力を矩形圧とする。
［８］ 熱硬化性樹脂（Ａ）と、高誘電率充填剤（Ｃ）と、を含む樹脂組成物を、２００℃で９０分加熱して硬化させた硬化物の、空洞共振器法による１８ＧＨｚでの誘電率が１０以上であり、誘電正接（ｔａｎδ）が０．０４以下である、熱硬化性樹脂組成物。The first invention (claims 1 to 8 as filed) can be shown in [1] to [8] below.
[1] (A) thermosetting resin;
(C) a high dielectric constant filler;
The high dielectric constant filler (C) is calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, zircon titanate. A thermosetting resin composition comprising at least one selected from calcium acid, lead zirconate titanate, barium magnesium niobate, and calcium zirconate.
[2] The thermosetting resin composition according to [1], further comprising an active ester curing agent (B1).
[3] The active ester curing agent (B1) includes an active ester curing agent containing a dicyclopentadiene type diphenol structure, an active ester curing agent containing a naphthalene structure, an active ester curing agent containing an acetylated product of phenol novolak, and a phenol curing agent. The thermosetting resin composition according to [2], which contains at least one selected from active ester curing agents including benzoylated novolacs.
[4] The thermosetting resin composition according to [2] or [3], wherein the active ester curing agent (B1) has a structure represented by the following general formula (1).

(In general formula (1), A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),

(In the general formula (B), Ar is a substituted or unsubstituted arylene group, and Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted is a cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is 0 It is an integer between ~4.)
k is the average value of repeating units and ranges from 0.25 to 3.5. )
[5] The thermosetting resin composition according to any one of [1] to [4], further comprising a curing catalyst (D).
[6] The thermosetting resin composition according to any one of [1] to [5], wherein the resin composition has a spiral flow length of 50 cm or more.
[7] The thermosetting resin composition according to any one of [1] to [6], which has a rectangular pressure of 0.1 MPa or more as measured under the following conditions.
(conditions)
Using a low-pressure transfer molding machine, the resin composition was injected into a rectangular channel with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm under conditions of a mold temperature of 175° C. and an injection speed of 177 mm ³ /sec. A pressure sensor embedded at a position 25 mm from the upstream end of the channel measures the change in pressure over time, calculates the lowest pressure when the resin composition is flowing, and defines this lowest pressure as the rectangular pressure.
[8] A cured product obtained by heating a resin composition containing a thermosetting resin (A) and a high dielectric constant filler (C) at 200° C. for 90 minutes to produce a 18 GHz signal using a cavity resonator method. A thermosetting resin composition having a dielectric constant of 10 or more and a dielectric loss tangent (tan δ) of 0.04 or less.

（一般式（１）中、Ａは、脂肪族環状炭化水素基を介して連結された置換または非置換のアリーレン基であり、Ａｒ’は、置換または非置換のアリール基であり、
Ｂは、下記一般式（Ｂ）で表される構造であり、

（一般式（Ｂ）中、Ａｒは、置換または非置換のアリーレン基であり、Ｙは、単結合、置換または非置換の炭素原子数１～６の直鎖のアルキレン基、または置換または非置換の炭素原子数３～６の環式のアルキレン基、置換または非置換の２価の芳香族炭化水素基、エーテル結合、カルボニル基、カルボニルオキシ基、スルフィド基、あるいはスルホン基である。ｎは０～４の整数である。）
ｋは、繰り返し単位の平均値であり、０．２５～３．５の範囲である。）
［１４］ さらに硬化触媒（Ｄ）を含む、［９］～［１３］のいずれかに記載の熱硬化性樹脂組成物。
［１５］ 前記熱硬化性樹脂組成物のスパイラルフローの流動長が５０ｃｍ以上である、［９］～［１４］のいずれかに記載の熱硬化性樹脂組成物。
［１６］ 熱硬化性樹脂（Ａ）と、硬化剤（Ｂ）と、高誘電率充填剤（Ｃ）と、を含む熱硬化性樹脂組成物を、２００℃で９０分加熱して硬化させた硬化物の、空洞共振器法による２５ＧＨｚでの誘電正接（ｔａｎδ）が０．０４以下である、熱硬化性樹脂組成物。The second invention (claims 9 to 16 as filed) can be shown in [9] to [16] below.
[9] (A) thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
A thermosetting resin composition in which the high dielectric constant filler (C) contains magnesium titanate.
[10] The thermosetting resin composition according to [9], wherein the high dielectric constant filler (C) further contains calcium titanate.
[11] The thermosetting resin according to [9] or [10], which contains the high dielectric constant filler (C) in an amount of 10% by mass or more and 90% by mass or less in 100% by mass of the thermosetting resin composition. Curable resin composition.
[12] The curing agent (B) includes an active ester curing agent (B1),
The active ester curing agent (B1) includes an active ester curing agent containing a dicyclopentadiene type diphenol structure, an active ester curing agent containing a naphthalene structure, an active ester curing agent containing an acetylated product of phenol novolac, and a benzoyl phenol novolac. The thermosetting resin composition according to any one of [9] to [11], which contains at least one selected from active ester curing agents containing compounds.
[13] The thermosetting resin composition according to [12], wherein the active ester curing agent (B1) has a structure represented by the following general formula (1).

(In general formula (1), A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),

(In the general formula (B), Ar is a substituted or unsubstituted arylene group, and Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted is a cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is 0 It is an integer between ~4.)
k is the average value of repeating units and ranges from 0.25 to 3.5. )
[14] The thermosetting resin composition according to any one of [9] to [13], further comprising a curing catalyst (D).
[15] The thermosetting resin composition according to any one of [9] to [14], wherein the thermosetting resin composition has a spiral flow length of 50 cm or more.
[16] A thermosetting resin composition containing a thermosetting resin (A), a curing agent (B), and a high dielectric constant filler (C) was cured by heating at 200° C. for 90 minutes. A thermosetting resin composition whose cured product has a dielectric loss tangent (tan δ) of 0.04 or less at 25 GHz measured by a cavity resonator method.

（一般式（１）中、Ａは、脂肪族環状炭化水素基を介して連結された置換または非置換のアリーレン基であり、Ａｒ’は、置換または非置換のアリール基であり、
Ｂは、下記一般式（Ｂ）で表される構造であり、

（一般式（Ｂ）中、Ａｒは、置換または非置換のアリーレン基であり、Ｙは、単結合、置換または非置換の炭素原子数１～６の直鎖のアルキレン基、または置換または非置換の炭素原子数３～６の環式のアルキレン基、置換または非置換の２価の芳香族炭化水素基、エーテル結合、カルボニル基、カルボニルオキシ基、スルフィド基、あるいはスルホン基である。ｎは０～４の整数である。）
ｋは、繰り返し単位の平均値であり、０．２５～３．５の範囲である。）The third invention (Claims 17 to 21 as filed) can be shown in [17] to [21] below.
[17] (A) thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
A thermosetting resin composition comprising,
The thermosetting resin (A) is an epoxy resin (A1),
The epoxy resin (A1) is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a naphthalene type epoxy resin, a dicyclopentadiene type epoxy resin, a glycidylamine type epoxy resin, a naphthol aralkyl type epoxy resin, and a phenol aralkyl type epoxy resin. At least one species selected from the group consisting of
The curing agent (B) contains an active ester curing agent (B1) and/or a phenol curing agent (B2),
The high dielectric constant filler (C) is calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, zircon titanate. A thermosetting resin composition comprising at least one selected from calcium acid, lead zirconate titanate, barium magnesium niobate, and calcium zirconate.
[18] The thermosetting resin composition according to [17], wherein the high dielectric constant filler (C) contains at least one selected from calcium titanate, strontium titanate, and magnesium titanate.
[19] The thermosetting resin composition according to [17] or [18], which contains the high dielectric constant filler (C) in an amount of 40% by mass or more in 100% by mass of the thermosetting resin composition. thing.
[20] The active ester curing agent (B1) includes an active ester curing agent containing a dicyclopentadiene type diphenol structure, an active ester curing agent containing a naphthalene structure, an active ester curing agent containing an acetylated product of phenol novolak, and a phenol curing agent. The thermosetting resin composition according to any one of [17] to [19], which contains at least one selected from active ester curing agents including benzoylated novolacs.
[21] The thermosetting resin composition according to any one of [17] to [20], wherein the active ester curing agent (B1) has a structure represented by the following general formula (1).

(In general formula (1), A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),

(In the general formula (B), Ar is a substituted or unsubstituted arylene group, and Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted is a cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is 0 It is an integer between ~4.)
k is the average value of repeating units and ranges from 0.25 to 3.5. )

The fourth invention (Claims 22 to 25 as filed) can be shown in [22] to [25] below.
[22] (A) thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
The thermosetting resin (A) is an epoxy resin (A1),
The epoxy resin (A1) contains a naphthol aralkyl type epoxy resin,
The high dielectric constant filler (C) is calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, zircon titanate. A thermosetting resin composition comprising at least one selected from calcium acid, lead zirconate titanate, barium magnesium niobate, and calcium zirconate.
[23] The thermosetting resin composition according to [22], wherein the naphthol aralkyl epoxy resin has an epoxy equivalent of 250 g/eq or more and 400 g/eq or less.
[24] The thermosetting resin composition according to [22] or [23], wherein the curing agent (B) contains an active ester curing agent (B1) and/or a phenol curing agent (B2).
[25] The thermosetting resin composition according to any one of [22] to [24], further comprising a curing catalyst (D).

The thermosetting resin compositions of the first to fourth inventions (Claims 1 to 25 as filed) can be used for the uses described in [26] to [31] below.
[26] The thermosetting resin composition according to any one of [1] to [25], which is used as a material for forming a microstrip antenna.
[27] The thermosetting resin composition according to any one of [1] to [25], which is used as a material for forming a dielectric waveguide.
[28] The thermosetting resin composition according to any one of [1] to [25], which is used as a material for forming an electromagnetic wave absorber.
[29] A dielectric substrate obtained by curing the thermosetting resin composition according to any one of [1] to [25].
[30] The dielectric substrate according to [29],
a radiation conductor plate provided on one surface of the dielectric substrate;
a ground conductor plate provided on the other surface of the dielectric substrate;
Microstrip antenna.
[31] Dielectric substrate,
a radiation conductor plate provided on one surface of the dielectric substrate;
a ground conductor plate provided on the other surface of the dielectric substrate;
a high dielectric material disposed opposite to the radiation conductor plate;
A microstrip antenna comprising:
A microstrip antenna, wherein the high dielectric material is constituted by the dielectric substrate according to [29].

According to a first invention, there is provided a resin composition from which a dielectric substrate excellent in high dielectric constant and low dielectric loss tangent can be obtained, a dielectric substrate made of the resin composition, and a microstrip antenna equipped with the dielectric substrate. can do.
Further, according to a second invention, there is provided a thermosetting resin composition capable of obtaining a dielectric substrate having an excellent low dielectric loss tangent, a dielectric substrate made of the resin composition, and a microstrip antenna equipped with the dielectric substrate. can be provided.
According to the third invention, a thermosetting resin composition from which a dielectric substrate having excellent high dielectric constant and low dielectric loss tangent can be obtained, a dielectric substrate made of the resin composition, and a microstrip provided with the dielectric substrate Antenna can be provided.
Further, according to the fourth invention, there is provided a thermosetting resin composition capable of obtaining a dielectric substrate having excellent dielectric properties such as low dielectric loss tangent, a dielectric substrate made of the resin composition, and the dielectric substrate. A microstrip antenna can be provided.

FIG. 2 is a top perspective view showing the microstrip antenna of this embodiment. FIG. 3 is a cross-sectional view showing another aspect of the microstrip antenna of this embodiment.

Hereinafter, the first invention (Claims 1 to 8 and 26 to 31 as filed) will be explained based on the first embodiment with reference to the drawings,
The second invention (claims 9 to 16 and 26 to 31 as filed) will be explained based on the second embodiment with reference to the drawings,
The third invention (Claims 17 to 21 and 26 to 31 as filed) will be explained based on the third embodiment with reference to the drawings,
The fourth invention (claims 22 to 25 and 26 to 31 as filed) will be explained based on the fourth embodiment with reference to the drawings.
Note that in all the drawings, similar components are denoted by the same reference numerals, and descriptions thereof will be omitted as appropriate. Further, for example, "1 to 10" represents "1 or more" to "10 or less" unless otherwise specified.

<First embodiment>
The thermosetting resin composition of this embodiment is
Contains a thermosetting resin (A) and a high dielectric constant filler (C).
Each component will be explained below.

.
[Thermosetting resin (A)]
In this embodiment, the thermosetting resin (A) is one selected from cyanate resins, epoxy resins, resins having two or more radically polymerizable carbon-carbon double bonds in one molecule, and maleimide resins. Or two or more types can be used. Among these, from the viewpoint of improving the effects of the present invention and the adhesiveness of the thermally conductive paste, it is particularly preferable to include the epoxy resin (A1).

As the epoxy resin (A1), monomers, oligomers, and polymers in general having two or more epoxy groups in one molecule can be used, and the molecular weight and molecular structure thereof are not limited.

The epoxy resin (A1) is, for example, a biphenyl type epoxy resin; a bisphenol type epoxy resin such as a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, or a tetramethylbisphenol F type epoxy resin; a stilbene type epoxy resin; a phenol novolac type epoxy resin; Novolac-type epoxy resins such as cresol novolac-type epoxy resins; polyfunctional epoxy resins such as trisphenol-type epoxy resins exemplified by triphenolmethane-type epoxy resins, alkyl-modified triphenolmethane-type epoxy resins, etc.; phenol aralkyl having a phenylene skeleton type epoxy resin, naphthol aralkyl type epoxy resin having a phenylene skeleton, phenol aralkyl type epoxy resin having a biphenylene skeleton, phenol aralkyl type epoxy resin such as naphthol aralkyl type epoxy resin having a biphenylene skeleton; dihydroxynaphthalene type epoxy resin, dihydroxynaphthalene type epoxy resin, etc. Naphthol-type epoxy resins such as epoxy resins obtained by glycidyl etherification of dimers; triazine core-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; bridged epoxy resins such as dicyclopentadiene-modified phenol-type epoxy resins It contains one or more selected from the group consisting of cyclic hydrocarbon compound-modified phenolic epoxy resins.

From the viewpoint of the effects of the present invention, among these, novolac type epoxy resins, polyfunctional epoxy resins, and phenol aralkyl type epoxy resins can be preferably used. Further, from the same viewpoint, the epoxy resin preferably contains one or more selected from the group consisting of an orthocresol novolak epoxy resin, a phenol aralkyl epoxy resin having a biphenylene skeleton, and a triphenylmethane epoxy resin, It is more preferable to include one or more selected from the group consisting of an orthocresol novolac type epoxy resin and a phenol aralkyl type epoxy resin having a biphenylene skeleton.

From the viewpoint of the effects of the present invention, the epoxy resin (A1) preferably contains 3% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, based on the entire thermosetting resin composition. I can do it. Further, the epoxy resin (A1) can be contained typically at most 20% by mass, more preferably at most 18% by mass, even more preferably at most 15% by mass.

[High dielectric constant filler (C)]
In this embodiment, the high dielectric constant filler (C) includes calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, and zirconate. Examples include barium, calcium zirconate titanate, lead zirconate titanate, barium magnesium niobate, and calcium zirconate, and one or more selected from these can be used.
By containing these high dielectric constant fillers (C), the thermosetting resin composition of this embodiment is excellent in high dielectric constant and low dielectric loss tangent, and also excellent in these effects in a high frequency band.

As the high dielectric constant filler (C), calcium titanate and strontium titanate are more preferable from the viewpoint of the effects of the present invention, particularly from the viewpoint of low dielectric loss tangent.

The shape of the high dielectric constant filler (C) is granular, amorphous, flake, etc., and high dielectric constant fillers having these shapes can be used in any ratio. The average particle diameter of the high dielectric constant filler is preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 20 μm or less, and even more preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 20 μm or less, and even more preferably .5 μm or more and 10 μm or less.

The blending amount of the high dielectric constant filler (C) is preferably 20% by mass to 80% by mass, more preferably 30% by mass to 70% by mass, even more preferably 40% by mass, based on the entire thermosetting resin composition. % to 60% by mass. When the amount of the high dielectric constant filler (C) is within the above range, the resulting cured product has a lower dielectric constant and is also excellent in producing molded products.

[Active ester curing agent (B1)]
The thermosetting resin composition of this embodiment can further contain an active ester curing agent (B1).
As the active ester curing agent (B1), a compound having one or more active ester groups in one molecule can be used. Among these, the active ester curing agent (B1) contains two ester groups with high reactivity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds having at least one of these are preferred.

Preferred specific examples of the active ester curing agent (B1) include an active ester curing agent containing a dicyclopentadiene type diphenol structure, an active ester curing agent containing a naphthalene structure, an active ester curing agent containing an acetylated product of phenol novolac, and phenol. Active ester curing agents including benzoylated novolacs may be mentioned, and at least one type thereof may be included. Among these, active ester curing agents containing a naphthalene structure and active ester curing agents containing a dicyclopentadiene type diphenol structure are more preferable. "Dicyclopentadiene type diphenol structure" refers to a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

In this embodiment, as the active ester curing agent (B1), for example, a resin having a structure represented by the following general formula (1) can be used.

In general formula (1), "B" is a structure represented by general formula (B).

In general formula (B), Ar is a substituted or unsubstituted arylene group. Examples of the substituents of the substituted arylene group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, an aralkyl group, and the like.
Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, a substituted or unsubstituted cyclic alkylene group having 3 to 6 carbon atoms, or a substituted or unsubstituted divalent aromatic hydrocarbon group, ether bond, carbonyl group, carbonyloxy group, sulfide group, or sulfone group. Examples of the substituent of the above group include an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, an aralkyl group, and the like.
Preferred examples of Y include a single bond, a methylene group, -CH(CH ₃ ) ₂ -, an ether bond, an optionally substituted cycloalkylene group, and an optionally substituted 9,9-fluorenylene group.
n is an integer from 0 to 4, preferably 0 or 1.
Specifically, B is a structure represented by the following general formula (B1) or the following general formula (B2).

In the general formula (B1) and the general formula (B2), Ar and Y have the same meanings as in the general formula (B).

A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group,
Ar' is a substituted or unsubstituted aryl group,
k is the average value of repeating units and ranges from 0.25 to 3.5.

Since the thermosetting resin composition of this embodiment contains a specific active ester curing agent, the resulting cured product can have excellent dielectric properties and is excellent in low dielectric loss tangent.

The active ester curing agent (B1) used in the thermosetting resin composition of this embodiment has an active ester group represented by formula (B). In the curing reaction between the epoxy resin and the active ester curing agent, the active ester group of the active ester curing agent reacts with the epoxy group of the epoxy resin to generate a secondary hydroxyl group. This secondary hydroxyl group is blocked by the ester residue of the active ester curing agent. Therefore, the dielectric loss tangent of the cured product is reduced.

In one embodiment, the structure represented by the above formula (B) is preferably at least one selected from the following formulas (B-1) to (B-6).

In formulas (B-1) to (B-6),
R ¹ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group,

R ² is each independently an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group, and X is a linear alkylene group having 2 to 6 carbon atoms, an ether a bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group,
n is an integer from 0 to 4, and p is an integer from 1 to 4.

The structures represented by the above formulas (B-1) to (B-6) are all highly oriented structures, so when an active ester curing agent containing them is used, the resulting thermosetting resin The cured product of the composition has a low dielectric loss tangent and excellent adhesion to metals, and therefore can be suitably used as a semiconductor encapsulation material.
Among these, from the viewpoint of low dielectric loss tangent, active ester curing agents having a structure represented by formula (B-2), formula (B-3) or formula (B-5) are preferable, and furthermore, active ester curing agents having a structure represented by formula (B-2), formula (B-3) or formula (B-5) are preferable. Active ester having a structure in which n is 0, a structure in which X in formula (B-3) is an ether bond, or a structure in which two carbonyloxy groups are at the 4,4'-position in formula (B-5) Curing agents are more preferred. Further, it is preferable that all R ¹ in each formula are hydrogen atoms.

"Ar'" in formula (1) is an aryl group, for example, phenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 3,5-xylyl group, o-biphenyl group, m-biphenyl group. p-biphenyl group, 2-benzylphenyl group, 4-benzylphenyl group, 4-(α-cumyl)phenyl group, 1-naphthyl group, 2-naphthyl group, etc. Among these, 1-naphthyl group or 2-naphthyl group is preferable because a cured product with a particularly low dielectric loss tangent can be obtained.

In this embodiment, "A" in the active ester curing agent represented by formula (1) is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group; Examples of the structure include a structure obtained by polyaddition reaction of an unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule and a phenolic compound.

Examples of the unsaturated aliphatic cyclic hydrocarbon compound containing two double bonds in one molecule include dicyclopentadiene, cyclopentadiene polymer, tetrahydroindene, 4-vinylcyclohexene, and 5-vinyl-2-norbornene. , limonene, etc., and each of these may be used alone or two or more types may be used in combination. Among these, dicyclopentadiene is preferred because it provides a cured product with excellent heat resistance. Since dicyclopentadiene is contained in petroleum fractions, industrial dicyclopentadiene may contain cyclopentadiene polymers and other aliphatic or aromatic diene compounds as impurities. However, in consideration of performance such as heat resistance, curability, and moldability, it is desirable to use a product with dicyclopentadiene purity of 90% by mass or more.

On the other hand, the phenolic compounds include, for example, phenol, cresol, xylenol, ethylphenol, isopropylphenol, butylphenol, octylphenol, nonylphenol, vinylphenol, isopropenylphenol, allylphenol, phenylphenol, benzylphenol, chlorophenol, bromophenol, Examples include 1-naphthol, 2-naphthol, 1,4-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, and 2,7-dihydroxynaphthalene, each of which can be used alone. It may be used or two or more types may be used together. Among these, phenol is preferred because it is an active ester curing agent with high curability and excellent dielectric properties in a cured product.

In a preferred embodiment, "A" in the active ester curing agent represented by formula (1) has a structure represented by formula (A). A thermosetting resin composition containing an active ester curing agent in which "A" in formula (1) has the following structure has a cured product having a low dielectric loss tangent and excellent adhesion to insert products.

In formula (A),
R ³ is each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group,
l is 0 or 1, and m is an integer of 1 or more.

Among the active ester curing agents represented by formula (1), more preferable ones include resins represented by the following formulas (1-1), (1-2), and (1-3), Particularly preferred are resins represented by the following formula (1-3).

In formula (1-1), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

In formula (1-2), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

In formula (1-3), R ¹ and R ³ are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a phenyl group, or an aralkyl group. , Z is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group having 1 to 3 alkyl groups having 1 to 4 carbon atoms on the aromatic nucleus, l is 0 or 1, and k is a repeating unit. It is the average of 0.25 to 3.5.

The active ester curing agent (B1) used in the present invention is composed of a phenolic compound (a) having a structure in which a plurality of aryl groups having a phenolic hydroxyl group are linked via an aliphatic cyclic hydrocarbon group, and an aromatic nucleus-containing dicarboxylic compound. It can be produced by a known method of reacting an acid or its halide (b) with an aromatic monohydroxy compound (c).

The reaction ratio of the phenolic compound (a), the aromatic nucleus-containing dicarboxylic acid or its halide (b), and the aromatic monohydroxy compound (c) can be adjusted as appropriate depending on the desired molecular design. Among them, since an active ester curing agent with higher curability is obtained, the phenolic compound (a) is ) has a phenolic hydroxyl group in the range of 0.25 to 0.90 mol, and the aromatic monohydroxy compound (c) has a hydroxyl group in a ratio of 0.10 to 0.75 mol. It is preferable to use raw materials such that the phenolic hydroxyl group possessed by the phenolic compound (a) is in the range of 0.50 to 0.75 mol, and the hydroxyl group possessed by the aromatic monohydroxy compound (c) is 0.50 to 0.75 mol. It is more preferable to use each raw material in a proportion ranging from 25 to 0.50 mol.

In addition, the functional group equivalent of the active ester curing agent (B1) has excellent curability and has a low dielectric constant and dielectric loss tangent when the total number of aryl carbonyloxy groups and phenolic hydroxyl groups in the resin structure is taken as the number of functional groups in the resin. Since a low cured product can be obtained, the range is preferably from 200 g/eq to 230 g/eq, and more preferably from 210 g/eq to 220 g/eq.

In the thermosetting resin composition of the present embodiment, the active ester curing agent (B1) and the epoxy resin (A1) are blended in an appropriate amount because a cured product with excellent curability and a low dielectric loss tangent can be obtained. The ratio is preferably such that the amount of epoxy groups in the epoxy resin (A1) is 0.8 to 1.2 equivalents per total equivalent of active groups in the curing agent (B1). Here, the active group in the active ester curing agent (B1) refers to the arylcarbonyloxy group and phenolic hydroxyl group contained in the resin structure.

In the composition of the present embodiment, the active ester curing agent (B1) is preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more, based on the entire thermosetting resin composition. It is used in an amount of 10% by mass or less, more preferably 1.0% by mass or more and 7% by mass or less.
By containing the specific active ester curing agent within the above range, the resulting cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

By using the active ester curing agent (B1) and the above-mentioned high dielectric constant filler (C) in combination, the resin blocker of this embodiment has excellent high dielectric constant and low dielectric loss tangent, and can also be used in high frequency bands. Excellent in these effects.
From the viewpoint of the above effects, the active ester curing agent (B1) is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 2 parts by mass or more, based on 100 parts by mass of the above-mentioned high dielectric constant filler (C). It can be contained in an amount of 20 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less.

Note that, as described in Japanese Patent Application Laid-Open No. 2020-90615, the present applicant has developed a thermosetting resin composition containing an epoxy resin and a predetermined active ester curing agent in a semiconductor encapsulation application different from the present invention. Developing things. The present invention differs from the technique described in the publication in that it contains a high dielectric constant filler. In addition, since it contains a high dielectric constant filler, the effects of the combination of the active ester curing agent and epoxy resin are different in that it has a high dielectric constant and is superior in high dielectric constant and low dielectric loss tangent in high frequency bands. ing.

[Other hardening agents]
The thermosetting resin composition of this embodiment can further contain a curing agent other than the active ester curing agent (B1).
Examples of curing agents include amine compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, and guanidine derivatives; dicyandiamide, linolenic acid dimer, and ethylenediamine. Amide compounds such as polyamide resins synthesized from: phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride , acid anhydrides such as methylhexahydrophthalic anhydride; phenol novolak resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylolmethane Resin, tetraphenylolethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (polyhydric phenol compound in which phenol cores are linked by bismethylene groups), biphenyl-modified resin Examples include polyhydric phenol compounds such as naphthol resin (a polyhydric naphthol compound in which a phenol nucleus is linked with bismethylene groups) and aminotriazine-modified phenol resin (a polyhydric phenol compound in which a phenol nucleus is linked to melamine, benzoguanamine, etc.). Phenolic aralkyl resins are preferred.

When using another curing agent together with the active ester curing agent (B1), the blending amount of the other curing agent is preferably 0.5% by mass or more and 20% by mass or less, more preferably 1% by mass or less, based on the thermosetting resin. The amount is .0% by mass or more and 15% by mass or less, more preferably 2.0% by mass or more and 10% by mass or less. By using the curing agent in an amount within the above range, a thermosetting resin composition having excellent curability can be obtained.

[Curing catalyst (D)]
The thermosetting resin composition of this embodiment can further contain a curing catalyst (D).
The curing catalyst (D) is sometimes called a curing accelerator. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin (A), and any known curing catalyst can be used.

Specifically, phosphorus atom-containing compounds such as organic phosphines, tetra-substituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, and adducts of phosphonium compounds and silane compounds; 2-methylimidazole, 2- Imidazole such as phenylimidazole (imidazole curing accelerator); 1,8-diazabicyclo[5.4.0]undecene-7, benzyldimethylamine, etc. are examples of amidine and tertiary amine; quaternary of amidine and amine; Nitrogen atom-containing compounds such as salts can be mentioned, and only one type may be used, or two or more types may be used.

Among these, from the viewpoint of improving hardenability and obtaining a magnetic material with excellent mechanical strength such as bending strength, it is preferable to include compounds containing phosphorus atoms, such as tetra-substituted phosphonium compounds, phosphobetaine compounds, phosphine compounds and quinone compounds. It is more preferable to include compounds with latent properties such as adducts between phosphonium compounds and silane compounds, tetra-substituted phosphonium compounds, adducts between phosphine compounds and quinone compounds, and adducts between phosphonium compounds and silane compounds. Adducts are particularly preferred.

By using the active ester curing agent (B1) represented by the general formula (1) in combination with a curing catalyst having latent properties, a magnetic material with excellent formability and mechanical strength such as bending strength can be obtained. be able to.

Examples of the organic phosphine include primary phosphines such as ethylphosphine and phenylphosphine; secondary phosphines such as dimethylphosphine and diphenylphosphine; and tertiary phosphines such as trimethylphosphine, triethylphosphine, tributylphosphine and triphenylphosphine.
Examples of the tetra-substituted phosphonium compound include compounds represented by the following general formula (6).

In general formula (6),
P represents a phosphorus atom.
R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent an aromatic group or an alkyl group.
A represents an anion of an aromatic organic acid having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in its aromatic ring.

AH represents an aromatic organic acid having at least one functional group selected from a hydroxyl group, a carboxyl group, and a thiol group in an aromatic ring.
x and y are 1 to 3, z is 0 to 3, and x=y.

The compound represented by general formula (6) can be obtained, for example, as follows.
First, a tetra-substituted phosphonium halide, an aromatic organic acid, and a base are mixed uniformly in an organic solvent, and an aromatic organic acid anion is generated in the solution system. Then, by adding water, the compound represented by general formula (6) can be precipitated. In the compound represented by general formula (6), R ⁴ , R ⁵ , R ⁶ and R ⁷ bonded to the phosphorus atom are phenyl groups, and AH is a compound having a hydroxyl group in the aromatic ring, that is, a phenol. , and A is preferably an anion of the phenol. The above-mentioned phenols include monocyclic phenols such as phenol, cresol, resorcinol, and catechol; condensed polycyclic phenols such as naphthol, dihydroxynaphthalene, and anthraquinol; and bisphenols such as bisphenol A, bisphenol F, and bisphenol S; Examples include polycyclic phenols such as phenylphenol and biphenol.

Examples of the phosphobetaine compound include a compound represented by the following general formula (7).

In general formula (7),
P represents a phosphorus atom.
R ⁸ represents an alkyl group having 1 to 3 carbon atoms, and R ⁹ represents a hydroxyl group.
f is 0-5 and g is 0-3.

The compound represented by general formula (7) can be obtained, for example, as follows.
First, a triaromatic substituted phosphine, which is a tertiary phosphine, is brought into contact with a diazonium salt, and the diazonium group of the triaromatic substituted phosphine and the diazonium salt is substituted.

Examples of the adduct of a phosphine compound and a quinone compound include a compound represented by the following general formula (8).

In general formula (8),
P represents a phosphorus atom.
R ¹⁰ , R ¹¹ and R ¹² represent an alkyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be the same or different from each other.

R ¹³ , R ¹⁴ and R ¹⁵ represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms, and may be the same or different from each other, and R ¹⁴ and R ¹⁵ are bonded to form a cyclic structure. It's okay.

Examples of phosphine compounds used in the adduct of a phosphine compound and a quinone compound include triphenylphosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, trinaphthylphosphine, tris(benzyl)phosphine, etc. It is preferable that the substituent is substituted or has a substituent such as an alkyl group or an alkoxyl group, and examples of the substituent such as an alkyl group or an alkoxyl group include those having 1 to 6 carbon atoms. Triphenylphosphine is preferred from the viewpoint of availability.

Furthermore, examples of the quinone compound used in the adduct of a phosphine compound and a quinone compound include benzoquinone and anthraquinones, and among them, p-benzoquinone is preferred from the viewpoint of storage stability.

As a method for producing an adduct of a phosphine compound and a quinone compound, the adduct can be obtained by contacting and mixing both the organic tertiary phosphine and the benzoquinone in a solvent that can dissolve them. The solvent is preferably a ketone such as acetone or methyl ethyl ketone, which has low solubility in the adduct. However, it is not limited to this.

In the compound represented by general formula (8), R ¹⁰ , R ¹¹ and R ¹² bonded to the phosphorus atom are phenyl groups, and R ¹³ , R ¹⁴ and R ¹⁵ are hydrogen atoms, that is, 1, A compound to which 4-benzoquinone and triphenylphosphine are added is preferred in that it lowers the thermal modulus of the cured product of the sealing resin composition.

Examples of the adduct of a phosphonium compound and a silane compound include a compound represented by the following general formula (9).

In general formula (9),
P represents a phosphorus atom, and Si represents a silicon atom.

R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ each represent an organic group having an aromatic ring or a heterocycle, or an aliphatic group, and may be the same or different from each other.
R ²⁰ is an organic group bonded to groups Y ² and Y ³ .
R ²¹ is an organic group bonded to groups Y ⁴ and Y ⁵ .

Y ² and Y ³ represent a group formed by a proton-donating group releasing a proton, and the groups Y ² and Y ³ in the same molecule bond to a silicon atom to form a chelate structure.

Y ⁴ and Y ⁵ represent a group formed by a proton-donating group releasing a proton, and the groups Y ⁴ and Y ⁵ in the same molecule bond to a silicon atom to form a chelate structure.
R ²⁰ and R ²¹ may be the same or different from each other, and Y ² , Y ³ , Y ⁴ and Y ⁵ may be the same or different from each other.
Z1 is an organic group having an aromatic ring or a heterocycle, or an aliphatic group.

In general formula (9), R ¹⁶ , R ¹⁷ , R ¹⁸ and R ¹⁹ are, for example, phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, naphthyl group, hydroxynaphthyl group, benzyl group, methyl group. , ethyl group, n-butyl group, n-octyl group, cyclohexyl group, etc. Among these, alkyl groups such as phenyl group, methylphenyl group, methoxyphenyl group, hydroxyphenyl group, hydroxynaphthyl group, and alkoxy groups , an aromatic group having a substituent such as a hydroxyl group, or an unsubstituted aromatic group is more preferable.

In general formula (9), R ²⁰ is an organic group bonded to Y ² and Y ³ . Similarly, R ²¹ is an organic group that is bonded to groups Y ⁴ and Y ⁵ . Y ² and Y ³ are groups formed by a proton-donating group releasing protons, and the groups Y ² and Y ³ in the same molecule bond to a silicon atom to form a chelate structure. Similarly, Y ⁴ and Y ⁵ are groups formed by a proton-donating group releasing protons, and the groups Y ⁴ and Y ⁵ in the same molecule combine with a silicon atom to form a chelate structure. The groups R ²⁰ and R ²¹ may be the same or different from each other, and the groups Y ² , Y ³ , Y ⁴ and Y5 may be the same or different from each other. The groups represented by -Y ² -R ²⁰ -Y ³ - and Y ⁴ -R ²¹ -Y ⁵ - in general formula (9) are groups in which the proton donor releases two protons. As a proton donor, an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule is preferable, and furthermore, an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule constituting the aromatic ring is preferable. An aromatic compound having at least two hydroxyl groups is preferred, and an aromatic compound having at least two hydroxyl groups on adjacent carbons constituting an aromatic ring is more preferred, such as catechol, pyrogallol, 1,2-dihydroxynaphthalene, 2,3-dihydroxy Naphthalene, 2,2'-biphenol, 1,1'-bi-2-naphthol, salicylic acid, 1-hydroxy-2-naphthoic acid, 3-hydroxy-2-naphthoic acid, chloranilic acid, tannic acid, 2-hydroxybenzyl Examples include alcohol, 1,2-cyclohexanediol, 1,2-propanediol, and glycerin, but among these, catechol, 1,2-dihydroxynaphthalene, and 2,3-dihydroxynaphthalene are more preferred.

^Z1 in the general formula (9) represents an organic group or aliphatic group having an aromatic ring or a heterocycle, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a butyl group, and a hexyl group. and aliphatic hydrocarbon groups such as octyl groups, aromatic hydrocarbon groups such as phenyl, benzyl, naphthyl, and biphenyl groups, glycidyloxy groups such as glycidyloxypropyl, mercaptopropyl, and aminopropyl groups, and mercapto Among these, methyl, ethyl, phenyl, naphthyl, and biphenyl groups are more preferable in terms of thermal stability. preferable.
A method for producing an adduct of a phosphonium compound and a silane compound is, for example, as follows.

A silane compound such as phenyltrimethoxysilane and a proton donor such as 2,3-dihydroxynaphthalene are added and dissolved in a flask containing methanol, and then a sodium methoxide-methanol solution is added dropwise while stirring at room temperature. Furthermore, when a solution prepared in advance in which a tetra-substituted phosphonium halide such as tetraphenylphosphonium bromide is dissolved in methanol is added dropwise thereto under stirring at room temperature, crystals are precipitated. When the precipitated crystals are filtered, washed with water, and dried under vacuum, an adduct of a phosphonium compound and a silane compound is obtained.

When using the curing catalyst (D), its content is preferably 0.01 to 1% by mass, more preferably 0.02 to 0.8% by mass, based on the entire thermosetting resin composition. By setting the value within such a numerical range, a sufficient curing accelerating effect can be obtained without excessively deteriorating other performances.

[Inorganic filler]
The thermosetting resin composition of the present embodiment can further contain an inorganic filler in addition to the high dielectric constant filler in order to reduce hygroscopicity, reduce the coefficient of linear expansion, improve thermal conductivity, and improve strength.

Inorganic fillers include fused silica, crystalline silica, alumina, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, forsterite, steatite, spinel, Examples include powders such as mullite and titania, beads made of spherical powders, and glass fibers. These inorganic fillers may be used alone or in combination of two or more. Among the above inorganic fillers, fused silica is preferred from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferred from the viewpoint of high thermal conductivity, and the shape of the filler is spherical from the viewpoint of fluidity during molding and mold abrasion resistance. is preferred.

The blending amount of the inorganic filler other than the high dielectric constant filler is preferably 15% by mass or more, 60% by mass or more based on the entire thermosetting resin composition, from the viewpoint of moldability, reduction of thermal expansion, and improvement of strength. It can be in the range of 20% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 50% by mass or less. Within the above range, thermal expansion property reduction and moldability are excellent.

[Other ingredients]
In addition to the above-mentioned components, the thermosetting resin composition of the present embodiment may contain various components such as a silane coupling agent, a mold release agent, a coloring agent, a dispersant, and a stress reducing agent, as necessary. can.

[Thermosetting resin composition]
The thermosetting resin composition of this embodiment can be manufactured by uniformly mixing the above-mentioned components. Examples of the manufacturing method include a method in which a predetermined amount of raw materials is sufficiently mixed using a mixer, etc., then melt-kneaded using a mixing roll, kneader, extruder, etc., and then cooled and pulverized. The obtained thermosetting resin composition may be made into tablets with a size and mass suitable for molding conditions, if necessary.

The thermosetting resin composition of this embodiment has a spiral flow length of 50 cm or more, preferably 55 cm or more, and more preferably 60 cm or more. Therefore, the thermosetting resin composition of this embodiment has excellent moldability.

In the spiral flow test, for example, using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), injection is performed at a mold temperature of 175°C into a mold for spiral flow measurement according to EMMI-1-66. This can be done by injecting the resin molding material under conditions of a pressure of 6.9 MPa and a curing time of 120 seconds and measuring the flow length.

Further, the thermosetting resin composition of the present embodiment has a rectangular pressure of 0.1 MPa or more, preferably 0.15 MPa or more, and more preferably 0.20 MPa or more, as measured under the following conditions.
The rectangular pressure is a parameter of melt viscosity, and the smaller the value, the lower the melt viscosity. Since the thermosetting resin composition of this embodiment has a rectangular pressure within the above range, it has excellent mold filling properties during molding.

(conditions)
Using a low-pressure transfer molding machine, the thermosetting resin composition was injected into a rectangular channel with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm under conditions of a mold temperature of 175° C. and an injection speed of 177 mm ³ /sec. Then, a pressure sensor buried at a position 25 mm from the upstream end of the flow path measures the change in pressure over time, calculates the minimum pressure when the thermosetting resin composition is flowing, and calculates this minimum pressure as the rectangular pressure. shall be.

The thermosetting resin composition containing the thermosetting resin of this embodiment and a high dielectric constant filler has the following dielectric constant and dielectric loss tangent ( tan δ).
The dielectric constant at 18 GHz measured by the cavity resonator method can be 10 or more, preferably 12 or more, more preferably 13 or more, particularly preferably 14 or more.
The dielectric loss tangent (tan δ) at 18 GHz measured by the cavity resonator method can be 0.04 or less, preferably 0.03 or less, more preferably 0.02 or less, particularly preferably 0.015 or less.

The cured product obtained from the resin composition of the present embodiment has a high dielectric constant and a low dielectric loss tangent in a high frequency band, so it can be used for high frequencies, shortening circuits and downsizing communication equipment, etc. It can be suitably used as a material for forming a strip antenna, a material for forming a dielectric waveguide, a material for forming an electromagnetic wave absorber, and the like.

<Second embodiment>
The thermosetting resin composition of this embodiment includes a thermosetting resin (A), a curing agent (B), and a high dielectric constant filler (C).
Each component will be explained below.

[Thermosetting resin (A)]
In this embodiment, the thermosetting resin (A) is one selected from cyanate resins, epoxy resins, resins having two or more radically polymerizable carbon-carbon double bonds in one molecule, and maleimide resins. Or two or more types can be used. Among these, from the viewpoint of the effects of the present invention, it is particularly preferable to include the epoxy resin (A1).
In this embodiment, preferable specific examples of the epoxy resin (A1) include those described in the epoxy resin (A1) in the above-mentioned first embodiment.

From the viewpoint of the effects of the present invention, the thermosetting resin (A) can be contained in an amount of 5% by mass or more, preferably 8% by mass or more, based on the entire thermosetting resin composition. Furthermore, the thermosetting resin (A) can typically be contained in an amount of 20% by mass or less, preferably 15% by mass or less.

[Curing agent (B)]
In this embodiment, the curing agent (B) can be any known curing agent as long as it achieves the effects of the present invention, but may include an active ester curing agent (B1) and/or a phenol curing agent (B2). I can do it.

(Active ester curing agent (B1))
As the active ester curing agent (B1), a compound having one or more active ester groups in one molecule can be used. Among these, active ester curing agents include those having two or more ester groups with high reaction activity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds are preferred.

Preferred specific examples of the active ester curing agent (B1) include those described in the active ester curing agent (B1) in the above-mentioned first embodiment, and can be produced in the same manner.

In addition, the functional group equivalent of the active ester curing agent (B1) is defined as the cured product with excellent curability and low dielectric loss tangent, when the total number of aryl carbonyloxy groups and phenolic hydroxyl groups in the resin structure is taken as the number of functional groups in the resin. is obtained, it is preferably in the range of 200 g/eq or more and 230 g/eq or less, and more preferably in the range of 210 g/eq or more and 220 g/eq or less.

In the thermosetting resin composition of the present embodiment, the active ester curing agent (B1) and the epoxy resin (A1) are blended in an appropriate amount because a cured product with excellent curability and a low dielectric loss tangent can be obtained. The ratio is preferably such that the amount of epoxy groups in the epoxy resin (A1) is 0.8 to 1.2 equivalents per total equivalent of active groups in the curing agent (B1). Here, the active group in the active ester curing agent (B1) refers to the arylcarbonyloxy group and phenolic hydroxyl group contained in the resin structure.

In the composition of the present embodiment, the active ester curing agent (B1) is preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass, based on the entire resin composition. Hereinafter, it is more preferably used in an amount of 1.0% by mass or more and 7% by mass or less.
By containing the specific active ester curing agent (B1) in the above range, the obtained cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

By using the active ester curing agent (B1) in combination with the high dielectric constant filler (C) described below, the resin composition of the present embodiment has excellent low dielectric loss tangent and maintains these effects even in high frequency bands. Excellent.
From the viewpoint of the above effects, the active ester curing agent (B1) is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 2 parts by mass or more, based on 100 parts by mass of the above-mentioned high dielectric constant filler (C). It can be contained in an amount of 20 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less.

Note that, as described in JP-A-2020-90615, the applicant has developed a resin composition containing an epoxy resin and a predetermined active ester curing agent for semiconductor encapsulation applications different from the present invention. are doing. The present invention differs from the technique described in the publication in that it contains a high dielectric constant filler. Furthermore, since it contains a high dielectric constant filler, the effect of the combination of the active ester curing agent and thermosetting resin is also different in that it has an excellent low dielectric loss tangent in a high frequency band.

(Phenol curing agent (B2))
As the phenol curing agent (B2), phenol novolak resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylolmethane resin, tetraphenylene Roll ethane resin, naphthol novolac resin, naphthol-phenol cocondensed novolak resin, naphthol-cresol cocondensed novolac resin, biphenyl-modified phenol resin (polyhydric phenol compound in which phenol nuclei are linked by bismethylene groups), biphenyl-modified naphthol resin (bismethylene Examples include polyhydric phenol compounds such as polyhydric naphthol compounds (polyhydric naphthol compounds in which phenol nuclei are linked with groups), aminotriazine-modified phenol resins (polyhydric phenol compounds in which phenol nuclei are linked with melamine, benzoguanamine, etc.).

The blending amount of the phenol curing agent (B2) is preferably 20% by mass or more and 70% by mass or less based on the thermosetting resin (A). By using the curing agent in an amount within the above range, a resin composition having excellent curability can be obtained.

In the composition of this embodiment, the phenol curing agent (B2) is preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, based on the entire thermosetting resin composition. It is used in an amount of 1.0% by mass or more and 7% by mass or less, more preferably 1.0% by mass or more and 7% by mass or less.
By containing the specific phenol curing agent (B2) in the above range, the obtained cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

The curing agent (B) of this embodiment can contain a curing agent other than the active ester curing agent (B1) and the phenol curing agent (B2).
Examples of other curing agents include amine compounds such as diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complexes, and guanidine derivatives; dicyandiamide, and linolenic acid dimers. Amide compounds such as polyamide resins synthesized from Examples include acid anhydrides such as phthalic acid and methylhexahydrophthalic anhydride.

[High dielectric constant filler (C)]
In this embodiment, the high dielectric constant filler (C) includes magnesium titanate.
The thermosetting resin composition of the present embodiment contains magnesium titanate as the high dielectric constant filler (C), thereby exhibiting an excellent low dielectric loss tangent and excellent effects even in a high frequency band.
It is preferable that the high dielectric constant filler (C) further contains calcium titanate in addition to magnesium titanate. As a result, the dielectric loss tangent is further excellent, and the effect is further excellent even in a high frequency band.

The high dielectric constant filler (C) further includes barium titanate, strontium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, calcium zirconate titanate. , lead zirconate titanate, barium magnesium niobate, calcium zirconate, and the like.

The shape of the high dielectric constant filler (C) is granular, amorphous, flake, etc., and these shapes of the high dielectric constant filler (C) can be used in any ratio. The average particle diameter of the high dielectric constant filler (C) is preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 20 μm or less, from the viewpoint of the effects of the present invention and fluidity/fillability. Preferably it is 0.5 μm or more and 10 μm or less.

The content of the high dielectric constant filler (C) is preferably 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 88% by mass or less, even more preferably The range is 40% by mass or more and 85% by mass or less. When the amount of the high dielectric constant filler (C) added is within the above range, the dielectric loss tangent of the resulting cured product will be lower, and the production of molded products will also be excellent.
When the high dielectric constant filler (C) consists only of magnesium titanate, the amount of magnesium titanate is preferably 30% by mass or more and 90% by mass or less, more preferably 35% by mass or less in 100% by mass of the resin composition. The range is from 88% by mass to 88% by mass, more preferably from 40% by mass to 85% by mass.
When the high dielectric constant filler (C) is composed of magnesium titanate and calcium titanate, the total amount of these fillers is preferably 30% by mass or more and 90% by mass or less in 100% by mass of the resin composition. The content is preferably 35% by mass or more and 88% by mass or less, more preferably 40% by mass or more and 85% by mass or less.

[Curing catalyst (D)]
The thermosetting resin composition of this embodiment can further contain a curing catalyst (D).
The curing catalyst (D) is sometimes called a curing accelerator. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin (A), and any known curing catalyst can be used.
Preferred specific examples of the curing catalyst (D) include those described in the curing catalyst (D) in the above-mentioned first embodiment, and can be produced in the same manner.

When using the curing catalyst (D), its content is preferably 0.01% by mass or more and 1% by mass or less, more preferably 0.02% by mass or more, 0.0% by mass or less, based on the entire thermosetting resin composition. .8% by mass or less. By setting the value within such a numerical range, a sufficient curing accelerating effect can be obtained without excessively deteriorating other performances.

[Inorganic filler]
The thermosetting resin composition of the present embodiment may further contain an inorganic filler in addition to the high dielectric constant filler (C) in order to reduce hygroscopicity, reduce linear expansion coefficient, improve thermal conductivity, and improve strength. I can do it.

Inorganic fillers include fused silica, crystalline silica, alumina, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, forsterite, steatite, spinel, Examples include powders such as mullite and titania, beads made of spherical powders, and glass fibers. These inorganic fillers may be used alone or in combination of two or more. Among the above inorganic fillers, fused silica is preferred from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferred from the viewpoint of high thermal conductivity, and the shape of the filler is spherical from the viewpoint of fluidity during molding and mold abrasion resistance. is preferred.

The blending amount of the inorganic filler other than the high dielectric constant filler (C) is preferably 15% by mass or more, 60% by mass or more based on the entire resin composition, from the viewpoint of moldability, reduction of thermal expansion, and improvement of strength. It can be in the range of 20% by mass or more and 50% by mass or less, more preferably 20% by mass or more and 50% by mass or less. Within the above range, thermal expansion property reduction and moldability are excellent.

[Other ingredients]
In addition to the above-mentioned components, the thermosetting resin composition of the present embodiment may contain various components such as a silane coupling agent, a mold release agent, a coloring agent, a dispersant, and a stress reducing agent, as necessary. can.

[Thermosetting resin composition]
The thermosetting resin composition of this embodiment includes the following thermosetting resin (A), the following active ester curing agent (B1) and/or the following phenol curing agent (B2) as a curing agent (B), and the following high A dielectric constant filler (C) may be included in combination.
(Thermosetting resin (A))
Preferably, it contains one or more selected from cyanate resins, epoxy resins, radically polymerizable resins having two or more carbon-carbon double bonds in one molecule, and maleimide resins.
More preferably, it contains an epoxy resin.

(Active ester curing agent (B1))
The active ester curing agent is selected from an active ester curing agent containing a dicyclopentadiene type diphenol structure, an active ester curing agent containing a naphthalene structure, an active ester curing agent containing an acetylated product of phenol novolak, and an active ester curing agent containing a benzoylated product of phenol novolak. Contains at least one species.
Preferably, at least one selected from an active ester curing agent containing a naphthalene structure and an active ester curing agent containing a dicyclopentadiene type diphenol structure is included.
More preferably, it is an active ester curing agent having a structure represented by the general formula (1).
In addition, the above-mentioned thermosetting resin (A) and the curing agent (B) containing the active ester curing agent (B1) can be combined arbitrarily.

(Phenol curing agent (B2))
Phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylolmethane resin, tetraphenylolethane resin, naphthol novolak resin, naphthol - Phenol co-condensed novolak resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (polyhydric phenol compound with phenol nuclei linked by bismethylene groups), biphenyl-modified naphthol resin (polyhydric phenol compound with phenol nuclei linked by bismethylene groups) and aminotriazine-modified phenol resins (polyhydric phenol compounds in which phenol nuclei are linked with melamine, benzoguanamine, etc.).

(High dielectric constant filler (C))
Contains magnesium titanate.
Preferably, it further contains calcium titanate.

Furthermore, the thermosetting resin composition of this embodiment,
The thermosetting resin (A) can be contained in 100% by mass of the composition, preferably in an amount of 5% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 15% by mass or less,
The active ester curing agent (B1) and/or the phenol curing agent (B2) is contained in 100% by mass of the composition, preferably from 0.2% by mass to 15% by mass, more preferably from 0.5% by mass to 10% by mass. It can be contained in an amount of 1.0% by mass or more and 7% by mass or less, more preferably 1.0% by mass or more and 7% by mass or less,
The high dielectric constant filler (C) is contained in 100% by mass of the composition, 10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 88% by mass or less, even more preferably 40% by mass or more and 85% by mass. It can be included in the following amounts:

In this embodiment, the above-mentioned thermosetting resin (A), a curing agent (B) containing an active ester curing agent (B1) and/or a phenol curing agent (B2), and a high dielectric constant filler (C) By containing the above in combination, it is possible to provide a thermosetting resin composition that provides an excellent dielectric substrate with a low dielectric loss tangent.

The thermosetting resin composition of this embodiment can be manufactured by uniformly mixing the above-mentioned components. Examples of the manufacturing method include a method in which a predetermined amount of raw materials is sufficiently mixed using a mixer, etc., then melt-kneaded using a mixing roll, kneader, extruder, etc., and then cooled and pulverized. The obtained thermosetting resin composition may be made into tablets with a size and mass suitable for molding conditions, if necessary.

The thermosetting resin composition of this embodiment has a spiral flow length of 50 cm or more, preferably 55 cm or more, and more preferably 60 cm or more. Therefore, the thermosetting resin composition of this embodiment has excellent moldability.

In the spiral flow test, for example, using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), injection is performed at a mold temperature of 175°C into a mold for spiral flow measurement according to EMMI-1-66. This can be done by injecting the resin molding material under conditions of a pressure of 6.9 MPa and a curing time of 120 seconds and measuring the flow length.

Further, the thermosetting resin composition of the present embodiment has a rectangular pressure of 0.1 MPa or more, preferably 0.15 MPa or more, and more preferably 0.20 MPa or more, as measured under the following conditions.
The rectangular pressure is a parameter of melt viscosity, and the smaller the value, the lower the melt viscosity. Since the thermosetting resin composition of this embodiment has a rectangular pressure within the above range, it has excellent mold filling properties during molding.

(conditions)
Using a low-pressure transfer molding machine, the resin composition was injected into a rectangular channel with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm under conditions of a mold temperature of 175° C. and an injection speed of 177 mm ³ /sec. A pressure sensor embedded at a position 25 mm from the upstream end of the channel measures the change in pressure over time, calculates the lowest pressure when the resin composition is flowing, and defines this lowest pressure as the rectangular pressure.

The resin composition containing the thermosetting resin (A), the active ester curing agent, and the high dielectric constant filler (C) of the present embodiment is cured by heating at 200°C for 90 minutes. , has the following dielectric loss tangent (tan δ).
The dielectric loss tangent (tan δ) at 25 GHz measured by the cavity resonator method can be 0.04 or less, preferably 0.03 or less, more preferably 0.02 or less, particularly preferably 0.015 or less.

The cured product obtained from the thermosetting resin composition of this embodiment has an excellent low dielectric loss tangent in a high frequency band, so it can be used for high frequencies, and can be used as a material for forming microstrip antennas and dielectric waveguides. It can be suitably used as a material for forming an electromagnetic wave absorber, as well as a material for forming an electromagnetic wave absorber.

The resin composition of this embodiment has the following dielectric constant in a cured product cured by heating at 200° C. for 90 minutes.
The dielectric constant at 25 GHz measured by the cavity resonator method can be 2 or more, preferably 3 or more, more preferably 4 or more, particularly preferably 5 or more.

<Third embodiment>
The thermosetting resin composition of this embodiment includes an epoxy resin (A1) as the thermosetting resin (A), a curing agent (B), and a high dielectric constant filler (C).
Each component will be explained below.

[Epoxy resin (A1)]
Examples of the epoxy resin (A1) include bisphenol A epoxy resin, bisphenol F epoxy resin, naphthalene epoxy resin, dicyclopentadiene epoxy resin, glycidylamine epoxy resin, naphthol aralkyl epoxy resin, phenol aralkyl epoxy resin, etc. and at least one selected from these. Note that the phenol aralkyl epoxy resin does not include a phenol aralkyl epoxy resin containing a biphenylene skeleton.
In this embodiment, the epoxy resin (A1) is preferably a naphthol aralkyl-type epoxy resin or a dicyclopentadiene-type epoxy resin, and more preferably a naphthol aralkyl-type epoxy resin, from the viewpoint of the effects of the present invention.
The epoxy resin (A1) can contain a combination of other epoxy resins, such as a biphenylaralkyl epoxy resin.

From the viewpoint of the effects of the present invention, the epoxy resin (A1) can be contained in an amount of 5% by mass or more and 20% by mass or less, preferably 10% by mass or more and 15% by mass or less, based on the entire thermosetting resin composition.

[Curing agent (B)]
In this embodiment, the curing agent (B) includes an active ester curing agent (B1) and/or a phenol curing agent (B2).
(Active ester curing agent (B1))
As the active ester curing agent (B1), a compound having one or more active ester groups in one molecule can be used. Among these, active ester curing agents include those having two or more ester groups with high reaction activity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds are preferred.
In this embodiment, a dielectric material excellent in high dielectric constant and low dielectric loss tangent is obtained by containing the above-mentioned specific epoxy resin (A1) in combination with an active ester curing agent (B1) as a curing agent (B). A substrate can be obtained.

Preferred specific examples of the active ester curing agent (B1) include those described in the active ester curing agent (B1) in the above-mentioned first embodiment, and can be produced in the same manner.

In addition, the functional group equivalent of the active ester curing agent (B1) is defined as the number of functional groups in the resin, which is the sum of the aryl carbonyloxy groups and phenolic hydroxyl groups in the resin structure. It is preferably in the range of 200 g/eq or more and 230 g/eq or less, and more preferably in the range of 210 g/eq or more and 220 g/eq or less.

In the thermosetting resin composition of the present embodiment, the active ester curing agent (B1) and the epoxy resin (A1) are blended in an appropriate amount because a cured product with excellent curability and a low dielectric loss tangent can be obtained. It is preferable that the ratio of epoxy groups in the epoxy resin (A1) is 0.8 to 1.2 equivalents to the total 1 equivalent of active groups in the curing agent. Here, the active group in the active ester curing agent refers to the arylcarbonyloxy group and phenolic hydroxyl group contained in the resin structure.

In the composition of the present embodiment, the active ester curing agent (B1) is preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more, based on the entire thermosetting resin composition. It is used in an amount of 10% by mass or less, more preferably 1.0% by mass or more and 7% by mass or less.
By containing the specific active ester curing agent (B1) in the above range, the obtained cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

By using the active ester curing agent (B1) in combination with the high dielectric constant filler (C) described below, the resin composition of the present embodiment has excellent high dielectric constant and low dielectric loss tangent, and can also be used in high frequency bands. Excellent in these effects.
From the viewpoint of the above effects, the active ester curing agent (B1) is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 2 parts by mass or more, based on 100 parts by mass of the high dielectric constant filler (C) described below. It can be contained in an amount of 20 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less.

Note that, as described in JP-A-2020-90615, the applicant has developed a resin composition containing an epoxy resin and a predetermined active ester curing agent for semiconductor encapsulation applications different from the present invention. are doing. The present invention differs from the technique described in the publication in that it contains a high dielectric constant filler. In addition, since it contains a high dielectric constant filler, the effects of the combination of the active ester curing agent and epoxy resin are different in that it has a high dielectric constant and is superior in high dielectric constant and low dielectric loss tangent in high frequency bands. ing.

(Phenol curing agent (B2))
As the phenol curing agent (B2), phenol novolak resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylolmethane resin, tetraphenylene Roll ethane resin, naphthol novolac resin, naphthol-phenol cocondensed novolak resin, naphthol-cresol cocondensed novolac resin, biphenyl-modified phenol resin (polyhydric phenol compound in which phenol nuclei are linked by bismethylene groups), biphenyl-modified naphthol resin (bismethylene Examples include polyhydric phenol compounds such as polyhydric naphthol compounds (polyhydric naphthol compounds in which phenol nuclei are linked with groups), aminotriazine-modified phenol resins (polyhydric phenol compounds in which phenol nuclei are linked with melamine, benzoguanamine, etc.).

The blending amount of the phenol curing agent (B2) is preferably 20% by mass or more and 70% by mass or less based on the epoxy resin (A1). By using the curing agent in an amount within the above range, a resin composition having excellent curability can be obtained.

When the curing agent (B) contains an active ester curing agent (B1) and a phenol curing agent (B2), the ratio of the content of the phenol curing agent b to the active ester curing agent a (b (parts by mass)/a (parts by mass) )) is preferably 0.5 or more and 8 or less, more preferably 1 or more and 5 or less, and still more preferably 1.5 or more and 3 or less.
By containing the active ester curing agent (B1) and the phenol curing agent (B2) in the above ratio, the resulting cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

In the composition of the present embodiment, the curing agent (B) containing the active ester curing agent (B1) and/or the phenol curing agent (B2) is preferably 0.2 mass by mass based on the entire thermosetting resin composition. % or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1.0% by mass or more and 7% by mass or less.
By containing the curing agent (B) in the above range, the obtained cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

[High dielectric constant filler (C)]
In this embodiment, the high dielectric constant filler (C) includes calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, and zirconate. Barium, calcium zirconate titanate, lead zirconate titanate, barium magnesium niobate, calcium zirconate, etc. can be mentioned, and at least one selected from these can be included.
From the viewpoint of the effects of the present invention, the high dielectric constant filler (C) is preferably at least one selected from calcium titanate, strontium titanate, and magnesium titanate; Magnesium is more preferred.

The shape of the high dielectric constant filler (C) is granular, amorphous, flake, etc., and these shapes of the high dielectric constant filler (C) can be used in any ratio. The average particle diameter of the high dielectric constant filler (C) is preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 20 μm or less, from the viewpoint of the effects of the present invention and fluidity/fillability. Preferably it is 0.5 μm or more and 10 μm or less.

The content of the high dielectric constant filler (C) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more in 100% by mass of the thermosetting resin composition. be. The upper limit is about 80% by mass or more.
When the amount of the high dielectric constant filler (C) added is within the above range, the obtained cured product has a high dielectric constant and a low dielectric loss tangent, and is also excellent in producing molded products.

[Curing catalyst (D)]
The thermosetting resin composition of this embodiment can further contain a curing catalyst (D).
The curing catalyst (D) is sometimes called a curing accelerator. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin, and any known curing catalyst can be used.
Preferred specific examples of the curing catalyst (D) include those described in the curing catalyst (D) in the above-mentioned first embodiment, and can be produced in the same manner.

In this embodiment, by using a combination of an active ester curing agent represented by the general formula (1) and a curing catalyst having latent properties, a magnetic material with excellent formability and mechanical strength such as bending strength can be obtained. can be obtained.

When the curing catalyst (D) is used, its content is preferably 0.01 to 1% by mass, more preferably 0.02 to 0.8% by mass, based on the entire resin composition. By setting the value within such a numerical range, a sufficient curing accelerating effect can be obtained without excessively deteriorating other properties.

[Inorganic filler]
The thermosetting resin composition of the present embodiment may further contain an inorganic filler in addition to the high dielectric constant filler (C) in order to reduce hygroscopicity, reduce linear expansion coefficient, improve thermal conductivity, and improve strength. I can do it.

Inorganic fillers include fused silica, crystalline silica, alumina, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, forsterite, steatite, spinel, Examples include powders such as mullite and titania, beads made of spherical powders, and glass fibers. These inorganic fillers may be used alone or in combination of two or more. Among the above inorganic fillers, fused silica is preferred from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferred from the viewpoint of high thermal conductivity, and the shape of the filler is spherical from the viewpoint of fluidity during molding and mold abrasion resistance. is preferred.

The blending amount of the inorganic filler other than the high dielectric constant filler (C) is preferably 15% by mass based on the entire thermosetting resin composition from the viewpoint of moldability, reduction of thermal expansion, and improvement of strength. The content can be in the range of 60% by mass or less, more preferably 20% by mass or more and 50% by mass or less. Within the above range, thermal expansion property reduction and moldability are excellent.

[Other ingredients]
In addition to the above-mentioned components, the thermosetting resin composition of the present embodiment may contain various components such as a silane coupling agent, a mold release agent, a coloring agent, a dispersant, and a stress reducing agent, as necessary. can.

[Thermosetting resin composition]
The thermosetting resin composition of this embodiment can contain a combination of the following epoxy resin (A1), the following curing agent (B), and the following high dielectric constant filler (C).
(Epoxy resin (A1))
Contains at least one selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, naphthalene epoxy resin, dicyclopentadiene epoxy resin, glycidylamine epoxy resin, and naphthol aralkyl epoxy resin.
Preferably, it contains at least one selected from the group consisting of dicyclopentadiene type epoxy resins and naphthol aralkyl type epoxy resins.
More preferred are naphthol aralkyl epoxy resins.

(Curing agent (B))
Contains an active ester curing agent (B1) and/or a phenol curing agent (B2).
It preferably contains an active ester curing agent (B1).
(Active ester curing agent (B1))
Active ester curing agents containing a dicyclopentadiene type diphenol structure, active ester curing agents containing a naphthalene structure, active ester curing agents containing an acetylated product of phenol novolak, and active ester curing agents containing a benzoylated product of phenol novolac. It contains at least one selected from the group consisting of agents.
Preferably, at least one selected from an active ester curing agent containing a naphthalene structure and an active ester curing agent containing a dicyclopentadiene type diphenol structure is included.
More preferably, it is an active ester curing agent having a structure represented by the general formula (1).

(High dielectric constant filler (C))
Calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, calcium zirconate titanate, lead zirconate titanate, niobate Contains at least one selected from barium magnesium acid and calcium zirconate.
Preferably, at least one selected from calcium titanate, strontium titanate, and magnesium titanate is included.
More preferably, it contains at least one selected from calcium titanate and magnesium titanate.
The above-mentioned epoxy resin (A1), curing agent (B) containing an active ester curing agent (B1) and/or phenolic curing agent (B2), and high dielectric constant filler (C) are each Examples can be arbitrarily combined.

Furthermore, the thermosetting resin composition of this embodiment,
The epoxy resin (A1) can be contained in 100% by mass of the composition, preferably in an amount of 5% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 15% by mass or less,
The curing agent (B) is contained in 100% by mass of the composition, preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1.0% by mass. % or more and 7% by mass or less,
The high dielectric constant filler (C) can be contained in 100% by mass of the composition, preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more. The upper limit is 80% by mass.

In this embodiment, the above-mentioned epoxy resin (A1), a curing agent (B) containing an active ester curing agent (B1), and a high dielectric constant filler (C) are included in combination. It is possible to provide a thermosetting resin composition from which a dielectric substrate with excellent dielectric constant and low dielectric loss tangent can be obtained.

The thermosetting resin composition of this embodiment can be manufactured by uniformly mixing the above-mentioned components. Examples of the manufacturing method include a method in which a predetermined amount of raw materials is sufficiently mixed using a mixer, etc., then melt-kneaded using a mixing roll, kneader, extruder, etc., and then cooled and pulverized. The obtained thermosetting resin composition may be made into tablets with a size and mass suitable for molding conditions, if necessary.

The thermosetting resin composition of this embodiment has a spiral flow length of 50 cm or more, preferably 55 cm or more, and more preferably 60 cm or more. Therefore, the thermosetting resin composition of this embodiment has excellent moldability.

In the spiral flow test, for example, using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), injection is performed at a mold temperature of 175°C into a mold for spiral flow measurement according to EMMI-1-66. This can be done by injecting the resin molding material under conditions of a pressure of 6.9 MPa and a curing time of 120 seconds and measuring the flow length.

Further, the thermosetting resin composition of the present embodiment has a rectangular pressure of 0.1 MPa or more, preferably 0.15 MPa or more, and more preferably 0.20 MPa or more, as measured under the following conditions.
The rectangular pressure is a parameter of melt viscosity, and the smaller the value, the lower the melt viscosity. Since the thermosetting resin composition of this embodiment has a rectangular pressure within the above range, it has excellent mold filling properties during molding.

(conditions)
Using a low-pressure transfer molding machine, the thermosetting resin composition was injected into a rectangular channel with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm under conditions of a mold temperature of 175° C. and an injection speed of 177 mm ³ /sec. Then, a pressure sensor buried at a position 25 mm from the upstream end of the flow path measures the change in pressure over time, calculates the minimum pressure when the thermosetting resin composition is flowing, and calculates this minimum pressure as the rectangular pressure. shall be.

The thermosetting resin composition of this embodiment has the following dielectric constant and dielectric loss tangent (tan δ) in a cured product cured by heating at 200° C. for 90 minutes.
The dielectric constant at 25 GHz measured by the cavity resonator method can be 10 or more, preferably 12 or more, more preferably 13 or more, particularly preferably 14 or more.
The dielectric loss tangent (tan δ) at 25 GHz measured by the cavity resonator method can be 0.04 or less, preferably 0.03 or less, more preferably 0.02 or less, particularly preferably 0.015 or less.

Since the cured product obtained from the thermosetting resin composition of this embodiment has excellent high dielectric constant and low dielectric loss tangent in high frequency bands, it is possible to achieve high frequencies and shorten circuits and miniaturize communication equipment, etc. It can be suitably used as a material for forming a microstrip antenna, a material for forming a dielectric waveguide, a material for forming an electromagnetic wave absorber, etc.

<Fourth embodiment>
The thermosetting resin composition of this embodiment includes an epoxy resin (A1), a curing agent (B), and a high dielectric constant filler (C).
Each component will be explained below.

[Epoxy resin (A1)]
In this embodiment, the epoxy resin (A1) includes a naphthol aralkyl type epoxy resin.
Examples of the naphthol aralkyl epoxy resin include epoxy resins represented by the following general formula (a).

In the general formula (a), R each independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, More preferred is a hydrogen atom. n is an integer from 1 to 10, preferably from 1 to 8.

From the viewpoint of the effects of the present invention, the epoxy equivalent of the naphthol aralkyl type epoxy resin is preferably 250 g/eq or more and 400 g/eq or less, more preferably 260 g/eq or more and 380 g/eq or less, and even more preferably 280 g/eq or more and 370 g/eq. /eq or less.

The softening point of the naphthol aralkyl epoxy resin is preferably 40°C or more and 150°C or less, more preferably 50°C or more and 120°C or less, and still more preferably 60°C or more and 100°C or less.

The naphthol aralkyl type epoxy resin has a melt viscosity at 150°C of preferably 0.01 Pa·s or more and 5 Pa·s or less, more preferably 0.02 Pa·s or more and 3 Pa·s or less, and still more preferably 0.05 Pa·s or more. It is 1 Pa·s or less.

The weight average molecular weight Mw of the naphthol aralkyl type epoxy resin of the present embodiment is preferably 100 or more and 5000 or less, more preferably 300 or more and 3000 or less, and even more preferably 500 or more and 2000 or less.

Further, the dispersity (weight average molecular weight Mw/number average molecular weight Mn) of the naphthol aralkyl type epoxy resin is preferably 1 or more and 4 or less, more preferably 1.1 or more and 3 or less, and still more preferably 1.2 or more and 2 or less. be. By appropriately adjusting the degree of dispersion, the physical properties of the epoxy resin can be made homogeneous, which is preferable.

For weight average molecular weight (Mw), number average molecular weight (Mn), and molecular weight distribution (Mw/Mn), polystyrene equivalent values obtained from a standard polystyrene (PS) calibration curve obtained by GPC measurement are used, for example. The measurement conditions for GPC measurement are, for example, as follows.
Tosoh gel permeation chromatography device HLC-8320GPC
Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation
Detector: RI detector for liquid chromatogram Measurement temperature: 40°C
Solvent: THF
Sample concentration: 2.0mg/ml

The epoxy resin (A1) of the present embodiment can contain other epoxy resins in addition to the naphthol aralkyl epoxy resin as long as the effects of the present invention are not impaired.
Other epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol aralkyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, glycidylamine type epoxy resin, etc. Aralkyl type epoxy resins are preferred.

When the epoxy resin (A1) contains a naphthol aralkyl epoxy resin and another epoxy resin, the content of the naphthol aralkyl epoxy resin in the epoxy resin (A1) (100% by mass) is preferably 2% by mass or more and 80% by mass. % or less, more preferably 5% by mass or more and 50% by mass or less, still more preferably 10% by mass or more and 40% by mass or less, particularly preferably 12% by mass or more and 30% by mass or less.
In this embodiment, the epoxy resin (A1) may contain only a naphthol aralkyl type epoxy resin.

From the viewpoint of the effects of the present invention, the thermosetting resin composition (100% by mass) of the present embodiment preferably contains 2% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less of the epoxy resin (A1). It can be contained in an amount of 5% by mass or more and 12% by mass or less, more preferably 5% by mass or more and 12% by mass or less.

[Curing agent (B)]
In this embodiment, the curing agent (B) includes an active ester curing agent (B1) and/or a phenol curing agent (B2).

(Active ester curing agent (B1))
As the active ester curing agent (B1), a compound having one or more active ester groups in one molecule can be used. Among these, active ester curing agents include those having two or more ester groups with high reaction activity in one molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds are preferred.
In this embodiment, by including the above-mentioned specific epoxy resin in combination with the active ester curing agent (B1) as a curing agent, a dielectric substrate excellent in high dielectric constant and low dielectric loss tangent can be obtained. .

Preferred specific examples of the active ester curing agent (B1) include those described in the active ester curing agent (B1) in the above-mentioned first embodiment, and can be produced in the same manner.

In addition, the functional group equivalent of the active ester curing agent (B1) has excellent curability and has a low dielectric constant and dielectric loss tangent when the total number of aryl carbonyloxy groups and phenolic hydroxyl groups in the resin structure is taken as the number of functional groups in the resin. Since a low cured product can be obtained, the range is preferably from 200 g/eq to 230 g/eq, and more preferably from 210 g/eq to 220 g/eq.

In the thermosetting resin composition of this embodiment, the blending amounts of the active ester curing agent (B1) and the epoxy resin (A1) are determined so that a cured product with excellent curability and low dielectric constant and dielectric loss tangent can be obtained. The ratio of the epoxy groups in the epoxy resin (A1) is preferably 0.8 to 1.2 equivalents per total equivalent of active groups in the active ester curing agent (B1). Here, the active group in the active ester curing agent refers to the arylcarbonyloxy group and phenolic hydroxyl group contained in the resin structure.

In the composition of the present embodiment, the active ester curing agent (B1) is preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more, based on the entire thermosetting resin composition. It is used in an amount of 10% by mass or less, more preferably 1.0% by mass or more and 7% by mass or less.
By containing the specific active ester curing agent within the above range, the resulting cured product can have better dielectric properties and is further excellent in low dielectric loss tangent.

By using the active ester curing agent (B1) in combination with the high dielectric constant filler (C) described below, the resin composition of the present embodiment has excellent high dielectric constant and low dielectric loss tangent, and can also be used in high frequency bands. Excellent in these effects.
From the viewpoint of the above effects, the active ester curing agent (B1) is preferably 1 part by mass or more and 30 parts by mass or less, more preferably 2 parts by mass or more and 20 parts by mass, based on 100 parts by mass of the high dielectric constant filler described below. The content is more preferably 3 parts by mass or more and 15 parts by mass or less.

Note that, as described in JP-A-2020-90615, the applicant has developed a resin composition containing an epoxy resin and a predetermined active ester curing agent for semiconductor encapsulation applications different from the present invention. are doing. The present invention differs from the technique described in the publication in that it contains a high dielectric constant filler. In addition, since it contains a high dielectric constant filler, the effects of the combination of the active ester curing agent and epoxy resin are different in that it has a high dielectric constant and is superior in high dielectric constant and low dielectric loss tangent in high frequency bands. ing.

(Phenol curing agent (B2))
Phenol curing agents include phenol novolak resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylolmethane resin, tetraphenylolethane resin. , naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin (a polyhydric phenol compound in which phenol nuclei are linked with bismethylene groups), biphenyl-modified naphthol resin (phenol in bismethylene groups) Polyhydric phenol compounds such as polyhydric naphthol compounds with linked nuclei) and aminotriazine-modified phenol resins (polyhydric phenol compounds with phenolic nuclei linked with melamine, benzoguanamine, etc.) can be mentioned.

The blending amount of the phenol curing agent (B2) is preferably 20% by mass or more and 70% by mass or less based on the thermosetting resin. By using the curing agent in an amount within the above range, a resin composition having excellent curability can be obtained.

The curing agent (B) of this embodiment is preferably an active ester curing agent (B1) from the viewpoint of the effects of the present invention.

[High dielectric constant filler (C)]
In this embodiment, the high dielectric constant filler (C) includes calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, and zirconate. Examples include barium, calcium zirconate titanate, lead zirconate titanate, barium magnesium niobate, and calcium zirconate, and at least one selected from these may be included.
From the viewpoint of the effects of the present invention, the high dielectric constant filler (C) is preferably at least one selected from calcium titanate, strontium titanate, and magnesium titanate; More preferably, it is at least one selected from magnesium.

The shape of the high dielectric constant filler (C) is granular, amorphous, flake, etc., and high dielectric constant fillers having these shapes can be used in any ratio. The average particle diameter of the high dielectric constant filler is preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 20 μm or less, and even more preferably 0.1 μm or more and 50 μm or less, more preferably 0.3 μm or more and 20 μm or less, and even more preferably .5 μm or more and 10 μm or less.

The content of the high dielectric constant filler (C) is preferably 40% by mass or more, more preferably 50% by mass or more, even more preferably 60% by mass or more in 100% by mass of the thermosetting resin composition. be. The upper limit is about 90% by mass or more.
When the amount of the high dielectric constant filler (C) is within the above range, the resulting cured product has a lower dielectric constant and is also excellent in producing molded products.

[Curing catalyst (D)]
The thermosetting resin composition of this embodiment can further contain a curing catalyst (D).
The curing catalyst (D) is sometimes called a curing accelerator. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin, and any known curing catalyst can be used.
Preferred specific examples of the curing catalyst (D) include those described in the curing catalyst (D) in the above-mentioned first embodiment, and can be produced in the same manner.

In this embodiment, by using an epoxy resin (A1) containing a naphthol aralkyl type epoxy resin in combination with a curing catalyst having latent properties, a magnetic material with excellent moldability and mechanical strength such as bending strength can be obtained. Obtainable.

When using the curing catalyst (D), its content is preferably 0.1 to 3% by mass, more preferably 0.5 to 2% by mass, based on 100% by mass of the thermosetting resin composition. By setting the value within such a numerical range, a sufficient curing accelerating effect can be obtained without excessively deteriorating other properties.

[Inorganic filler]
The thermosetting resin composition of the present embodiment may further contain an inorganic filler in addition to the high dielectric constant filler (C) in order to reduce hygroscopicity, reduce linear expansion coefficient, improve thermal conductivity, and improve strength. I can do it.

Inorganic fillers include fused silica, crystalline silica, alumina, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, silicon nitride, aluminum nitride, boron nitride, beryllia, zirconia, zircon, forsterite, steatite, spinel, Examples include powders such as mullite and titania, beads made of spherical powders, and glass fibers. These inorganic fillers may be used alone or in combination of two or more. Among the above inorganic fillers, fused silica is preferred from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferred from the viewpoint of high thermal conductivity, and the shape of the filler is spherical from the viewpoint of fluidity during molding and mold abrasion resistance. is preferred.

The blending amount of the inorganic filler other than the high dielectric constant filler is preferably 3% by mass or more based on 100% by mass of the thermosetting resin composition from the viewpoint of moldability, reduction of thermal expansion, and improvement of strength. , 40% by mass or less, more preferably 5% by mass or more and 30% by mass or less, still more preferably 10% by mass or more and 25% by mass or less. Within the above range, thermal expansion property reduction and moldability are excellent.

[Other ingredients]
In addition to the above-mentioned components, the thermosetting resin composition of the present embodiment may contain various components such as a silane coupling agent, a mold release agent, a coloring agent, a dispersant, and a stress reducing agent, as necessary. can.

The thermosetting resin composition of the present embodiment includes an epoxy resin (A1), a curing agent (B), and a high dielectric constant filler (C), and the epoxy resin (A1) is a naphthol aralkyl type epoxy resin. including.
The thermosetting resin composition of this embodiment containing a combination of such components can provide a dielectric substrate with excellent dielectric properties such as low dielectric loss tangent, and can further provide a microstrip antenna equipped with the dielectric substrate. can be provided.

The thermosetting resin composition of this embodiment is
The epoxy resin (A1) is preferably contained in 100% by mass of the composition, preferably 2% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass or less, even more preferably 5% by mass or more and 12% by mass or less. can contain in the amount of
The curing agent (B) is contained in 100% by mass of the composition, preferably 0.2% by mass or more and 15% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1.0% by mass. % or more and 7% by mass or less,
The high dielectric constant filler (C) can be contained in 100% by mass of the solid content of the composition, preferably 40% by mass or more, more preferably 50% by mass or more, still more preferably 60% by mass or more. The upper limit is 90% by mass.

In this embodiment, by containing a combination of an epoxy resin (A1) containing a naphthol aralkyl type epoxy resin, a curing agent (B), and a high dielectric constant filler (C), high dielectric constant and low dielectric A thermosetting resin composition from which a dielectric substrate with excellent tangent can be obtained can be provided.

The thermosetting resin composition of this embodiment can be manufactured by uniformly mixing the above-mentioned components. Examples of the manufacturing method include a method in which a predetermined amount of raw materials is sufficiently mixed using a mixer, etc., then melt-kneaded using a mixing roll, kneader, extruder, etc., and then cooled and pulverized. The obtained thermosetting resin composition may be made into tablets with a size and mass suitable for molding conditions, if necessary.

The thermosetting resin composition of this embodiment has a spiral flow length of 50 cm or more, preferably 55 cm or more, and more preferably 60 cm or more. Therefore, the thermosetting resin composition of this embodiment has excellent moldability.

In the spiral flow test, for example, using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), injection is performed at a mold temperature of 175°C into a mold for spiral flow measurement according to EMMI-1-66. This can be done by injecting the resin molding material under conditions of a pressure of 6.9 MPa and a curing time of 120 seconds and measuring the flow length.

The gel time of the thermosetting resin composition of this embodiment is preferably 40 seconds or more and 150 seconds or less, more preferably 50 seconds or more and 120 seconds or less.
By setting the gel time of the thermosetting resin composition to the above-mentioned lower limit or more, the filling property is excellent, and by setting the gel time to the above-mentioned upper limit or less, the moldability becomes good.

The thermosetting resin composition of this embodiment has the following dielectric constant and dielectric loss tangent (tan δ) in a cured product cured by heating at 200° C. for 90 minutes.
The dielectric constant at 25 GHz by the cavity resonator method can be 3 or more, preferably 4 or more, and more preferably 5 or more.
The dielectric loss tangent (tan δ) at 25 GHz measured by the cavity resonator method can be 0.04 or less, preferably 0.03 or less, more preferably 0.02 or less, particularly preferably 0.015 or less.

Since the cured product obtained from the thermosetting resin composition of this embodiment has excellent high dielectric constant and low dielectric loss tangent in high frequency bands, it is possible to achieve high frequencies and shorten circuits and miniaturize communication equipment, etc. It can be suitably used as a material for forming a microstrip antenna, a material for forming a dielectric waveguide, a material for forming an electromagnetic wave absorber, etc.

<Microstrip antenna>
As shown in FIG. 1, the microstrip antenna 10 of this embodiment includes a dielectric substrate 12 formed by curing the above-mentioned resin composition, and a radiation conductor plate (radiation conductor plate) provided on one surface of the dielectric substrate 12. element) 14, and a ground conductor plate 16 provided on the other surface of the dielectric substrate 12. At least a portion of the radiation conductor plate 12 is embedded in the dielectric substrate 12.

The shape of the radiation conductor plate may be rectangular or circular. In this embodiment, an example using a rectangular radiation conductor plate 14 will be explained.

The radiation conductor plate 14 includes any one of a metal material, an alloy of metal materials, a cured product of metal paste, and a conductive polymer. Metal materials include copper, silver, palladium, gold, platinum, aluminum, chromium, nickel, cadmium lead, selenium, manganese, tin, vanadium, lithium, cobalt, titanium, and the like. Alloys include multiple metallic materials. The metal paste agent includes one obtained by kneading a powder of a metal material with an organic solvent and a binder. The binder includes epoxy resin, polyester resin, polyimide resin, polyamideimide resin, and polyetherimide resin. Conductive polymers include polythiophene polymers, polyacetylene polymers, polyaniline polymers, polypyrrole polymers, and the like.

As shown in FIG. 1, the microstrip antenna 10 of this embodiment has a radiation conductor plate 14 with a length L and a width W, and resonates at a frequency where L corresponds to an integral multiple of 1/2 wavelength. . When using the dielectric substrate 12 having a high dielectric constant as in this embodiment, the thickness h of the dielectric substrate 12 and the width W of the radiation conductor plate 14 are designed to be sufficiently small with respect to the wavelength.

The ground conductor plate 16 is a thin plate made of a highly conductive metal such as copper, silver, or gold. The thickness may be sufficiently thin relative to the center operating frequency of the antenna device, and may be about 1/50th to 1/1000th wavelength of the center operating frequency.

Power feeding methods for microstrip antennas include direct feeding methods such as back coaxial feeding and coplanar feeding, and electromagnetic coupling feeding methods such as slot coupled feeding and proximity coupled feeding.

In the rear coaxial power feeding, power can be fed from the back surface of the antenna to the radiation conductor plate 14 using a coaxial line or a connector that penetrates the ground conductor plate 16 and the dielectric substrate 12.
In coplanar power feeding, power can be fed to the radiation conductor plate 14 using a microstrip line (not shown) arranged on the same plane as the radiation conductor plate 14.

In the slot coupled power supply, another dielectric substrate (not shown) is provided to sandwich the ground conductor plate 16, and the radiation conductor plate 14 and the microstrip line are formed on separate dielectric substrates. The radiation conductor plate 14 is excited by electromagnetically coupling the radiation conductor plate 14 and the microstrip line through the slots formed in the ground conductor plate 16.

In the close-coupled power supply, the dielectric substrate 12 has a laminated structure, and includes a dielectric substrate on which the radiation conductor plate 14 is formed, and a dielectric substrate on which the strip conductor of the microstrip line and the ground conductor plate 16 are arranged. It is layered. The radiation conductor plate 14 is excited by extending the strip conductor of the microstrip line below the radiation conductor plate 14 and electromagnetically coupling the radiation conductor plate 14 and the microstrip line.

FIGS. 2(a) and 2(b) show other embodiments of the microstrip antenna. Note that the same components as those in FIG. 1 are given the same numbers, and description thereof will be omitted as appropriate.
As shown in FIG. 2(a), the microstrip antenna 20 includes a dielectric substrate 22, a radiation conductor plate 14 provided on one surface of the dielectric substrate 22, and a radiation conductor plate 14 provided on the other surface of the dielectric substrate 22. The radiation conductor plate 16 includes a ground conductor plate 16 , and a high dielectric substrate (high dielectric material) 24 disposed opposite to the radiation conductor plate 14 . The dielectric substrate 22, the radiation conductor plate 14, and the high dielectric substrate 24 can be configured to be separated by a predetermined distance via a spacer 26.
The dielectric substrate 22 is made of a low dielectric constant substrate such as a Teflon substrate.
The high dielectric substrate 24 is constituted by a dielectric substrate formed by curing the above-mentioned resin composition.
The gap between the dielectric substrate 22 and the high dielectric substrate 24 may be a space, or may be filled with a dielectric material.
Alternatively, as shown in a microstrip antenna 20' in FIG. 2(b), a structure may be adopted in which a high dielectric substrate 24 is brought into contact with the upper surface of the radiation conductor plate 14.

<Dielectric waveguide>
In this embodiment, the dielectric waveguide includes a dielectric formed by curing the resin composition of this embodiment, and a conductor film covering the surface of the dielectric. A dielectric waveguide confines electromagnetic waves in a dielectric (dielectric medium) and transmits them.
The conductor film can be made of metal such as copper, oxide high temperature superconductor, or the like.

<Electromagnetic wave absorber>
In this embodiment, the electromagnetic wave absorber has a structure in which a support, a resistive film, a dielectric layer, and a reflective layer are laminated. The electromagnetic wave absorber can be used as a λ/4 type radio wave absorber having high radio wave absorption performance.
Examples of the support include resin base materials. The support can protect the resistive film and improve its durability as a radio wave absorber.
Examples of the resistive film include indium tin oxide and molybdenum-containing resistive films.
The dielectric layer is formed by curing the resin composition of this embodiment. Its thickness is about 10 μm or more and 2000 μm or less.
The reflective layer can function as a radio wave reflective layer, and includes, for example, a metal film.

Although the embodiments of the present invention have been described above, these are merely examples of the present invention, and various configurations other than those described above can be adopted within a range that does not impair the effects of the present invention.

EXAMPLES The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited thereto.
An example of the first invention (claims 1 to 8 and 26 to 31 as filed) and the first embodiment is shown in Example A.
Example B shows an example of the second invention (Claims 9 to 16 and 26 to 31 as filed) and the second embodiment.
An example of the third invention (Claims 17 to 21 and 26 to 31 as filed) and the third embodiment is shown in Example C.
Example D shows an example of the fourth invention (Claims 22 to 25 and 26 to 31 as filed) and the fourth embodiment.

<Example A>
(Examples A1 to A12, Comparative Example A1)
The following raw materials were mixed in the amounts shown in Table 1 using a mixer at room temperature, and then kneaded with rolls at 70 to 100°C. Next, the obtained kneaded product was cooled and then ground to obtain a powdery resin composition. Then, a tablet-shaped resin composition was obtained by compression molding under high pressure.

(High dielectric constant filler)
・High dielectric constant filler 1: Barium titanate (BT-UP2, average particle size 2 μm, manufactured by Nihon Kagaku Kogyo Co., Ltd.)
・High dielectric constant filler 2: Calcium titanate (CT, average particle size 2.0 μm, manufactured by Fuji Titanium Co., Ltd.)
・High dielectric constant filler 3: Strontium titanate (ST-A, average particle size 1.6 μm, manufactured by Fuji Titanium Co., Ltd.)
・High dielectric constant filler 4: Strontium titanate (STG, average particle size 0.9 μm, manufactured by Nihon Kagaku Kogyo Co., Ltd.)

(Inorganic filler)
・Inorganic filler 1: Alumina (K75-1V25F, manufactured by Denka Corporation)
・Inorganic filler 2: Fused spherical silica (SC-2500-SQ, manufactured by Admatex)

(colorant)
・Coloring agent 1: Black titanium oxide (manufactured by Ako Kasei Co., Ltd.)

(coupling agent)
・Coupling agent 1: Phenylaminopropyltrimethoxysilane (CF4083, manufactured by Dow Corning Toray)
・Coupling agent 2: 3-mercaptopropyltrimethoxysilane (Sila Ace, manufactured by JNC)

(Epoxy resin)
・Epoxy resin 1: Biphenylene skeleton-containing phenol aralkyl epoxy resin (NC3000L, manufactured by Nippon Kayaku Co., Ltd.)
・Epoxy resin 2: Triphenol methane type epoxy resin (E1032H60, manufactured by Yuka Shell Epoxy Co., Ltd.)

(hardening agent)
・Curing agent 1: Biphenylene skeleton-containing phenol aralkyl resin (MEH-7851SS, manufactured by Meiwa Kasei Co., Ltd.)

・Curing agent 2: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
In a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, add 279.1 g of biphenyl-4,4'-dicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene. were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0.

・Curing agent 3: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
203.0 g of 1,3-benzenedicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer. After charging, the system was replaced with nitrogen under reduced pressure to dissolve. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-3). The average value k of the repeating units of the active ester resin was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of the repeating units was 0.5 to 1.0.

(catalyst)
・Catalyst 1: Tetraphenylphosphonium-4,4'-sulfonyldiphenolate ・Catalyst 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate

(Release agent)
・Release agent 1: Glycerin trimontanate (Recolb WE-4, manufactured by Clariant Japan)
・Release agent 2: Carnauba wax (TOWAX-132, manufactured by Toagosei Co., Ltd.)

(Additive)
・Additive 1: 3-amino-5-mercapto-1,2,4-triazole (manufactured by Nippon Carbide Kogyo Co., Ltd.)
・Silicone 1: Dimethylsiloxane-diglycidine ether copolymer (M69B, manufactured by Sumitomo Bakelite Co., Ltd.)

(Low stress agent)
・Low stress agent 1: Carboxyl group-terminated butadiene acrylic rubber (CTBN1008SP, manufactured by Ube Industries, Ltd.)

(Evaluation of permittivity and dielectric loss tangent by cavity resonator method)
First, a test piece was obtained using a resin composition.
Specifically, the resin compositions prepared in Examples and Comparative Examples were applied to a Si substrate and prebaked at 120° C. for 4 minutes to form a resin film with a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes under a nitrogen atmosphere, and treated with hydrofluoric acid (immersed in a 2% by mass hydrofluoric acid aqueous solution). After removing the substrate from the hydrofluoric acid, the cured film was peeled off from the Si substrate and used as a test piece.
The measurement devices used were a network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies). These devices and a cylindrical cavity resonator (inner diameter 42 mm, height 30 mm) were set up.
The resonant frequency, 3 dB bandwidth, transmitted power ratio, etc. were measured at a frequency of 18 GHz with and without the test piece inserted into the resonator. Then, by analytically calculating these measurement results using software, dielectric properties such as permittivity (Dk) and dielectric loss tangent (Df) were determined. Note that the measurement mode was TE ₀₁₁ mode.

(Spiral flow measurement)
Using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), a mold for spiral flow measurement according to EMMI-1-66 was molded at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and curing. The resin compositions obtained in Examples and Comparative Examples were injected for a time of 120 seconds, and the flow length was measured.

(Gel Time (GT))
The resin compositions of Examples and Comparative Examples were each melted on a hot plate heated to 175° C., and the time (unit: seconds) until hardening was measured while kneading with a spatula.

(molding shrinkage rate)
For each Example and Comparative Example, the molding shrinkage rate (after ASM) of the obtained resin composition was measured after molding (as Mold), and after the molding, it was fully cured and used as a dielectric substrate. The molding shrinkage rate (after PMC) was evaluated under heating conditions (PMC: Post Mold Cure) assumed to be produced.
First, a JIS The molding shrinkage rate (after ASM) was obtained according to K 6911.
Further, the obtained test piece was heat treated at 175° C. for 4 hours, and the molding shrinkage rate (after ASM) was measured according to JIS K 6911.

(Glass transition temperature, coefficient of linear expansion)
For each Example and Comparative Example, the glass transition temperature (Tg) and coefficient of linear expansion (CTE1, CTE2) of the obtained cured resin composition were measured as follows. First, a sealing resin composition was injection molded using a low pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.) at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and a curing time of 120 seconds. A test piece of 10 mm x 4 mm x 4 mm was obtained. Next, the obtained test piece was post-cured at 175°C for 4 hours, and then measured using a thermomechanical analyzer (TMA100, manufactured by Seiko Electronics Co., Ltd.) at a temperature range of 0°C to 320°C and a heating rate. The measurement was performed under the condition of 5°C/min. From this measurement result, the glass transition temperature (Tg), the coefficient of linear expansion below the glass transition temperature (CTE1), and the coefficient of linear expansion above the glass transition temperature (CTE2) were calculated.

(Evaluation of mechanical strength (bending strength/flexural modulus))
The resin compositions of Examples and Comparative Examples were molded using a low-pressure transfer molding machine (KTS-30 manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 130°C, an injection pressure of 9.8 MPa, and a curing time of 300 seconds. Injection molded into a mold. As a result, a molded product with a width of 10 mm, a thickness of 4 mm, and a length of 80 mm was obtained. Next, the obtained molded article was post-cured at 175° C. for 4 hours. In this way, a test piece for mechanical strength evaluation was prepared. Then, the bending strength (N/mm ² ) and bending elastic modulus (N/mm ² ) of the test piece at room temperature (25°C) or 260°C were measured at a head speed of 5 mm/min in accordance with JIS K 6911. .

(Measurement of rectangular pressure)
The rectangular pressure of the resin compositions of Examples and Comparative Examples was measured as follows. First, using a low-pressure transfer molding machine (manufactured by NEC Corporation, 40t manual press), a rectangle with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm was formed under the conditions of a mold temperature of 175°C and an injection speed of 177 mm ³ /sec. A resin composition was injected into the shaped channel. At this time, a pressure sensor embedded at a position 25 mm from the upstream end of the flow path measured the change in pressure over time, and the lowest pressure (MPa) during flow of the resin composition was measured, and this was defined as the rectangular pressure. The rectangular pressure is a parameter of melt viscosity, and a smaller value indicates a lower melt viscosity.

As shown in Table 1, compared to the comparative example using barium titanate, the resin composition of the example according to the present invention has a high dielectric constant and a low dielectric constant due to the inclusion of a specific high dielectric constant filler. A dielectric substrate with excellent tangent and also excellent balance of other physical properties was obtained. It was surmised that a microstrip antenna equipped with a dielectric substrate formed by curing the resin composition would enable higher frequencies, and thus shorter circuits and smaller communication equipment. Furthermore, it has been inferred that the desired effect can also be obtained in a dielectric waveguide or an electromagnetic wave absorber that includes a dielectric (layer) formed by curing the resin composition.

<Example B>
(Examples B1 to B9)
The following raw materials were mixed in the amounts shown in Table 2 using a mixer at room temperature, and then kneaded with rolls at 70 to 100°C. Next, the obtained kneaded product was cooled and then ground to obtain a powdery resin composition. Then, a tablet-shaped resin composition was obtained by compression molding under high pressure.

(High dielectric constant filler)
・High dielectric constant filler 1: Magnesium titanate (average particle size 0.8 μm)
・High dielectric constant filler 2: Calcium titanate (average particle size 2.0 μm)

(Inorganic filler)
・Inorganic filler 1: Alumina (average particle size 11 μm, manufactured by Denka Corporation)
・Inorganic filler 2: Fused spherical silica (manufactured by Denka Corporation)

(colorant)
・Coloring agent 1: Black titanium oxide (manufactured by Ako Kasei Co., Ltd.)

(coupling agent)
・Coupling agent 1: Phenylaminopropyltrimethoxysilane (CF4083, manufactured by Dow Corning Toray)
・Coupling agent 2: 3-mercaptopropyltrimethoxysilane (Sila Ace, manufactured by JNC)

(Epoxy resin)
・Epoxy resin 1: Biphenylene skeleton-containing phenol aralkyl epoxy resin (NC3000L, manufactured by Nippon Kayaku Co., Ltd.)
・Epoxy resin 2: Naphthol aralkyl type epoxy resin (ESN-475V, manufactured by Nippon Steel Chemical Co., Ltd.)
・Epoxy resin 3: Biphenyl type epoxy resin (Mitsubishi Chemical Corporation, YX-4000K)

(hardening agent)
・Curing agent 1: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
In a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, add 279.1 g of biphenyl-4,4'-dicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene. were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0.

・Curing agent 2: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
203.0 g of 1,3-benzenedicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer. After charging, the system was replaced with nitrogen under reduced pressure to dissolve. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-3). The average value k of the repeating units of the active ester resin was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of the repeating units was 0.5 to 1.0.

(catalyst)
・Catalyst 1: Tetraphenylphosphonium-4,4'-sulfonyldiphenolate ・Catalyst 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate

(Release agent)
・Release agent 1: Glycerin trimontanate (Recolb WE-4, manufactured by Clariant Japan)

(Additive)
・Silicone 1: Dimethylsiloxane-diglycidine ether copolymer (M69B, manufactured by Sumitomo Bakelite Co., Ltd.)

(Low stress agent)
・Low stress agent 1: Carboxyl group-terminated butadiene acrylic rubber (CTBN1008SP, manufactured by Ube Industries, Ltd.)

(Evaluation of permittivity and dielectric loss tangent by cavity resonator method)
First, a test piece was obtained using a resin composition.
Specifically, the resin composition prepared in the example was applied to a Si substrate and prebaked at 120° C. for 4 minutes to form a resin film with a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes under a nitrogen atmosphere, and treated with hydrofluoric acid (immersed in a 2% by mass hydrofluoric acid aqueous solution). After removing the substrate from the hydrofluoric acid, the cured film was peeled off from the Si substrate and used as a test piece.
The measurement devices used were a network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies). These devices and a cylindrical cavity resonator (inner diameter 42 mm, height 30 mm) were set up.
The resonant frequency, 3 dB bandwidth, transmitted power ratio, etc. were measured at a frequency of 25 GHz with and without the test piece inserted into the resonator. Then, by analytically calculating these measurement results using software, dielectric properties such as permittivity (Dk) and dielectric loss tangent (Df) were determined. Note that the measurement mode was TE ₀₁₁ mode.

(Spiral flow measurement)
Using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), a mold for spiral flow measurement according to EMMI-1-66 was molded at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and curing. The resin composition obtained in the example was injected for a time of 120 seconds, and the flow length was measured.

(Gel Time (GT))
After each resin composition of the example was melted on a hot plate heated to 175° C., the time (unit: seconds) until hardening was measured while kneading with a spatula.

(Evaluation of mechanical strength (bending strength/flexural modulus))
The resin composition of the example was molded into a mold using a low-pressure transfer molding machine (KTS-30 manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 130°C, an injection pressure of 9.8 MPa, and a curing time of 300 seconds. Injection molded. As a result, a molded product with a width of 10 mm, a thickness of 4 mm, and a length of 80 mm was obtained. Next, the obtained molded article was post-cured at 175° C. for 4 hours. In this way, a test piece for mechanical strength evaluation was prepared. Then, the bending strength (N/mm ² ) and bending elastic modulus (N/mm ² ) of the test piece at room temperature (25°C) or 260°C were measured at a head speed of 5 mm/min in accordance with JIS K 6911. .

As shown in Table 2, the thermosetting resin compositions of Examples according to the present invention were excellent in low dielectric loss tangents by containing high dielectric constant fillers, particularly by containing magnesium titanate. From this, it has become clear that the thermosetting resin composition of the present invention can be suitably used as a material for forming a microstrip antenna, a material for forming a dielectric waveguide, and a material for forming an electromagnetic wave absorber. .

<Example C>
(Examples C1 to C17)
The following raw materials were mixed in the amounts shown in Table 3 using a mixer at room temperature, and then roll kneaded at 70 to 100°C. Next, the obtained kneaded product was cooled and then ground to obtain a powdery resin composition. Then, a tablet-shaped resin composition was obtained by compression molding under high pressure.

(Inorganic filler)
・Inorganic filler 1: Fused spherical silica (manufactured by Denka Corporation)

(High dielectric constant filler)
・High dielectric constant filler 1: Calcium titanate (average particle size 2.0 μm)
・High dielectric constant filler 2: Magnesium titanate, (average particle size 0.8 μm, surface treated, manufactured by Titan Kogyo Co., Ltd.)

(colorant)
・Coloring agent 1: Black titanium oxide (manufactured by Ako Kasei Co., Ltd.)

(coupling agent)
・Coupling agent 1: Phenylaminopropyltrimethoxysilane (CF4083, manufactured by Dow Corning Toray)
・Coupling agent 2: 3-mercaptopropyltrimethoxysilane (Sila Ace, manufactured by JNC)

(Epoxy resin)
・Epoxy resin 1: Biphenylene skeleton-containing phenol aralkyl epoxy resin (NC3000L, manufactured by Nippon Kayaku Co., Ltd.)
・Epoxy resin 2: Naphthol aralkyl type epoxy resin (ESN-475V, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.)
・Epoxy resin 3: Bisphenol A type epoxy resin (YL6810, manufactured by Mitsubishi Chemical Corporation)
・Epoxy resin 4: Bisphenol F type epoxy resin (jER806H, manufactured by Mitsubishi Chemical Corporation)
・Epoxy resin 5: Phenol aralkyl type epoxy resin (Milex E-XLC-4L (epoxy equivalent 238 g/eq, softening point 62°C), manufactured by Mitsui Chemicals)
・Epoxy resin 6: Naphthalene type epoxy resin (EPICLON HP-4770, manufactured by DIC)
・Epoxy resin 7: Dicyclopentadiene type epoxy resin (EPICLON HP-7200L, manufactured by DIC)
・Epoxy resin 8: Glycidylamine type epoxy resin (jER603, manufactured by Mitsubishi Chemical Corporation)

(hardening agent)
・Curing agent 1: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
In a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, add 279.1 g of biphenyl-4,4'-dicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene. were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0.

・Curing agent 2: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
203.0 g of 1,3-benzenedicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer. After charging, the system was replaced with nitrogen under reduced pressure to dissolve. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-3). The average value k of the repeating units of the active ester resin was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of the repeating units was 0.5 to 1.0.

(curing catalyst)
・Curing catalyst 1: Tetraphenylphosphonium-4,4'-sulfonyl diphenolate

(Additive)
・Silicone 1: Dimethylsiloxane-diglycidine ether copolymer (M69B, manufactured by Sumitomo Bakelite Co., Ltd.)

(Low stress agent)
・Low stress agent 1: Carboxyl group-terminated butadiene acrylic rubber (CTBN1008SP, manufactured by Ube Industries, Ltd.)

(Evaluation of permittivity and dielectric loss tangent by cavity resonator method)
First, a test piece was obtained using a resin composition.
Specifically, the resin composition prepared in the example was applied to a Si substrate and prebaked at 120° C. for 4 minutes to form a resin film with a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes under a nitrogen atmosphere, and treated with hydrofluoric acid (immersed in a 2% by mass hydrofluoric acid aqueous solution). After removing the substrate from the hydrofluoric acid, the cured film was peeled off from the Si substrate and used as a test piece.
The measurement devices used were a network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies). These devices and a cylindrical cavity resonator (inner diameter 42 mm, height 30 mm) were set up.
The resonant frequency, 3 dB bandwidth, transmitted power ratio, etc. were measured at a frequency of 25 GHz with and without the test piece inserted into the resonator. Then, by analytically calculating these measurement results using software, dielectric properties such as permittivity (Dk) and dielectric loss tangent (Df) were determined. Note that the measurement mode was TE ₀₁₁ mode.

(Spiral flow measurement)
Using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), a mold for spiral flow measurement according to EMMI-1-66 was molded at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and curing. The resin composition obtained in the example was injected for a time of 120 seconds, and the flow length was measured.

(Gel Time (GT))
After each resin composition of the example was melted on a hot plate heated to 175° C., the time (unit: seconds) until hardening was measured while kneading with a spatula.

(Evaluation of mechanical strength (bending strength/flexural modulus))
The resin composition of the example was molded into a mold using a low-pressure transfer molding machine (KTS-30 manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 130°C, an injection pressure of 9.8 MPa, and a curing time of 300 seconds. Injection molded. As a result, a molded product with a width of 10 mm, a thickness of 4 mm, and a length of 80 mm was obtained. Next, the obtained molded article was post-cured at 175° C. for 4 hours. In this way, a test piece for mechanical strength evaluation was prepared. Then, the bending strength (N/mm ² ) and bending elastic modulus (N/mm ² ) of the test piece at room temperature (25°C) or 260°C were measured at a head speed of 5 mm/min in accordance with JIS K 6911. .

(Measurement of rectangular pressure)
The rectangular pressure of the resin composition of the example was measured as follows. First, using a low-pressure transfer molding machine (manufactured by NEC Corporation, 40t manual press), a rectangle with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm was formed under the conditions of a mold temperature of 175°C and an injection speed of 177 mm ³ /sec. A resin composition was injected into the shaped channel. At this time, a pressure sensor embedded at a position 25 mm from the upstream end of the flow path measured the change in pressure over time, and the lowest pressure (MPa) during flow of the resin composition was measured, and this was defined as the rectangular pressure. The rectangular pressure is a parameter of melt viscosity, and a smaller value indicates a lower melt viscosity.

From the results in Table 3, according to the thermosetting resin composition of the present invention, by containing the epoxy resin (A1), the curing agent (B), and the high dielectric constant filler (C), it is possible to particularly improve the specific epoxy resin. It has become clear that by using this method, a dielectric substrate having an excellent high dielectric constant and low dielectric loss tangent, or in other words, a dielectric substrate having an excellent balance of these properties, can be obtained.

<Example D>
(Examples D1 to D8)
The following raw materials were mixed in the amounts shown in Table 4 using a mixer at room temperature, and then roll kneaded at 70 to 100°C. Next, the obtained kneaded product was cooled and then ground to obtain a powdery resin composition. Then, a tablet-shaped resin composition was obtained by compression molding under high pressure.

(Inorganic filler)
・Inorganic filler 1: Fused spherical silica (manufactured by Denka Corporation)

(High dielectric constant filler)
・High dielectric constant filler 1: Calcium titanate (average particle size 2.0 μm)
・High dielectric constant filler 2: Magnesium titanate (average particle size 0.8 μm)
・High dielectric constant filler 3: Strontium titanate (average particle size 1.6 μm)

(colorant)
・Coloring agent 1: Black titanium oxide (manufactured by Ako Kasei Co., Ltd.)

(coupling agent)
・Coupling agent 1: Phenylaminopropyltrimethoxysilane (product name CF4083, manufactured by Dow Corning Toray)
・Coupling agent 2: 3-mercaptopropyltrimethoxysilane (product name Sila Ace, manufactured by JNC)

(Epoxy resin)
・Epoxy resin 1: Biphenylene skeleton-containing phenol aralkyl epoxy resin (product name NC3000L, manufactured by Nippon Kayaku Co., Ltd.)
・Epoxy resin 2: naphthol aralkyl type epoxy resin (in the general formula (a), R is a hydrogen atom, epoxy equivalent: 310 to 350 g/eq, softening point: 70 to 90 °C, 150 °C melt viscosity: 0.1 to 0 .4Pa・s) (Product name: ESN-475V, manufactured by Nippon Steel Chemical Co., Ltd.)

(hardening agent)
・Curing agent 1: Active ester curing agent prepared by the following preparation method (preparation method of active ester curing agent)
In a flask equipped with a thermometer, dropping funnel, condenser tube, fractionator tube, and stirrer, add 279.1 g of biphenyl-4,4'-dicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene. were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0.

・Curing agent 2: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
203.0 g of 1,3-benzenedicarboxylic acid dichloride (number of moles of acid chloride group: 2.0 moles) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, cooling tube, fractionating tube, and stirrer. After charging, the system was replaced with nitrogen under reduced pressure to dissolve. Next, 96.5 g (0.67 mol) of α-naphthol and 219.5 g (mol number of phenolic hydroxyl group: 1.33 mol) of dicyclopentadiene phenol resin were charged, and the system was replaced with nitrogen under reduced pressure to dissolve them. Ta. Thereafter, while performing a nitrogen gas purge, the inside of the system was controlled at 60° C. or lower, and 400 g of a 20% aqueous sodium hydroxide solution was added dropwise over a period of 3 hours. Stirring was then continued under these conditions for 1.0 hour. After the reaction was completed, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Furthermore, water was added to the toluene phase in which the reactants were dissolved, and the mixture was stirred and mixed for about 15 minutes, and the mixture was allowed to stand still for liquid separation to remove the aqueous layer. This operation was repeated until the pH of the aqueous layer reached 7. Thereafter, water was removed by dehydration using a decanter to obtain an active ester resin in the form of a toluene solution with a nonvolatile content of 65%. When the structure of the obtained active ester resin was confirmed, it had a structure in which R ¹ and R ³ are hydrogen atoms, Z is a naphthyl group, and l is 0 in the above formula (1-3). The average value k of the repeating units of the active ester resin was calculated from the reaction equivalence ratio and was in the range of 0.5 to 1.0. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of the repeating units was 0.5 to 1.0.

(catalyst)
・Catalyst 1: Tetraphenylphosphonium-4,4'-sulfonyldiphenolate ・Catalyst 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenyl silicate

(Release agent)
・Release agent 1: Glycerin trimontanate ester (product name: Recolb WE-4, manufactured by Clariant Japan)

(Silicone compound)
・Silicone compound 1: Dimethylsiloxane-diglycidine ether copolymer (product name: M69B, manufactured by Sumitomo Bakelite Co., Ltd.)

(Low stress agent)
・Low stress agent 1: Carboxyl group-terminated butadiene acrylic rubber (product name: CTBN1008SP, manufactured by Ube Industries, Ltd.)

(Evaluation of permittivity and dielectric loss tangent by cavity resonator method)
First, a test piece was obtained using a resin composition.
Specifically, the resin composition prepared in the example was applied to a Si substrate and prebaked at 120° C. for 4 minutes to form a resin film with a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes under a nitrogen atmosphere, and treated with hydrofluoric acid (immersed in a 2% by mass hydrofluoric acid aqueous solution). After removing the substrate from the hydrofluoric acid, the cured film was peeled off from the Si substrate and used as a test piece.
The measurement devices used were a network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies). These devices and a cylindrical cavity resonator (inner diameter 42 mm, height 30 mm) were set up.
The resonant frequency, 3 dB bandwidth, transmitted power ratio, etc. were measured at a frequency of 25 GHz with and without the test piece inserted into the resonator. Then, by analytically calculating these measurement results using software, dielectric properties such as permittivity (Dk) and dielectric loss tangent (Df) were determined. Note that the measurement mode was TE ₀₁₁ mode.

(Spiral flow)
Using a low-pressure transfer molding machine (KTS-15 manufactured by Kotaki Seiki Co., Ltd.), a mold for spiral flow measurement according to EMMI-1-66 was molded at a mold temperature of 175°C, an injection pressure of 6.9 MPa, and curing. The resin composition obtained in the example was injected for a time of 120 seconds, and the flow length was measured.

(Gel Time (GT))
After each resin composition of the example was melted on a hot plate heated to 175° C., the time (unit: seconds) until hardening was measured while kneading with a spatula.

(Evaluation of mechanical strength (bending strength/flexural modulus))
The resin composition of the example was molded into a mold using a low-pressure transfer molding machine (KTS-30 manufactured by Kotaki Seiki Co., Ltd.) under conditions of a mold temperature of 130°C, an injection pressure of 9.8 MPa, and a curing time of 300 seconds. Injection molded. As a result, a molded product with a width of 10 mm, a thickness of 4 mm, and a length of 80 mm was obtained. Next, the obtained molded article was post-cured at 175° C. for 4 hours. In this way, a test piece for mechanical strength evaluation was prepared. Then, the bending strength (N/mm ² ) and bending elastic modulus (N/mm ² ) of the test piece at room temperature (25°C) or 260°C were measured at a head speed of 5 mm/min in accordance with JIS K 6911. .

As shown in Table 4, the thermosetting resin composition of the example according to the present invention contains an epoxy resin (A1), a curing agent (B), and a high dielectric constant filler (C), so that the thermosetting resin composition is By containing a type epoxy resin, it had an excellent low dielectric loss tangent and a high dielectric constant. In other words, it has an excellent balance between low dielectric loss tangent and high dielectric constant, and the thermosetting resin composition of the present invention can be used as a material for forming a microstrip antenna, a material for forming a dielectric waveguide, and a material for forming an electromagnetic wave absorber. It has become clear that it can be suitably used as a material.

This application is filed in Japanese Patent Application No. 2021-051748 filed on March 25, 2021, Japanese Patent Application No. 2021-172197 filed on October 21, 2021, and filed on December 6, 2021. Japanese Patent Application No. 2021-197667 filed on December 6, 2021, Japanese Patent Application No. 2021-197679 filed on December 6, 2021, 2021 Claims priority based on Japanese Patent Application No. 2021-197720 filed on December 6, 2021 and Japanese Patent Application No. 2021-197731 filed on December 6, 2021, and all of the disclosures thereof Import here.

10 Microstrip antenna 12 Dielectric substrate 14 Radiation conductor plate 16 Ground conductor plate 20, 20' Microstrip antenna 22 Dielectric substrate 24 High dielectric substrate 26 Spacer a Cavity part

Claims (23)

(A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
The curing agent (B) includes an active ester curing agent (B1), and the active ester curing agent (B1) has a structure represented by the following general formula (1),
The high dielectric constant filler (C) is calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, zircon titanate. A thermosetting resin composition containing at least one selected from calcium acid, lead zirconate titanate, barium magnesium niobate, and calcium zirconate (provided that the total content of calcium titanate particles and strontium titanate particles (Excluding cases where the percentage is 30% by volume or more and less than 60% by volume based on the entire inorganic filler) .

(In general formula (1), A is a substituted or unsubstituted arylene group connected via an aliphatic cyclic hydrocarbon group, Ar' is a substituted or unsubstituted aryl group,
B is a structure represented by the following general formula (B),

(In the general formula (B), Ar is a substituted or unsubstituted arylene group, and Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted is a cyclic alkylene group having 3 to 6 carbon atoms, a substituted or unsubstituted divalent aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. n is 0 It is an integer between ~4.)
k is the average value of repeating units and ranges from 0.25 to 3.5. ) The thermosetting resin composition according to claim 1 , further comprising a curing catalyst (D). The thermosetting resin composition according to claim 1 or 2 , wherein the thermosetting resin composition has a spiral flow length of 50 cm or more. The thermosetting resin composition according to any one of claims 1 to 3 , wherein the rectangular pressure measured under the following conditions is 0.1 MPa or more.
(conditions)
Using a low-pressure transfer molding machine, the resin composition was injected into a rectangular channel with a width of 13 mm, a thickness of 1 mm, and a length of 175 mm under conditions of a mold temperature of 175° C. and an injection speed of 177 mm ³ /sec. A pressure sensor embedded at a position 25 mm from the upstream end of the channel measures the change in pressure over time, calculates the lowest pressure when the resin composition is flowing, and defines this lowest pressure as the rectangular pressure. The thermosetting resin composition is cured by heating at 200° C. for 90 minutes, and the dielectric constant at 18 GHz measured by the cavity resonator method is 10 or more, and the dielectric loss tangent (tan δ) is 0.04 or less. The thermosetting resin composition according to any one of claims 1 to 4 . (A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
The curing agent (B) includes an active ester curing agent (B1), and the active ester curing agent (B1) has a structure represented by the general formula (1),
The thermosetting resin composition according to claim 1, wherein the high dielectric constant filler (C) contains magnesium titanate. The thermosetting resin composition according to claim 6 , wherein the high dielectric constant filler (C) further contains calcium titanate. The thermosetting resin composition according to claim 6 or 7 , wherein the high dielectric constant filler (C) is contained in an amount of 10% by mass or more and 90% by mass or less in 100% by mass of the thermosetting resin composition. . The thermosetting resin composition according to any one of claims 6 to 8 , further comprising a curing catalyst (D). The thermosetting resin composition according to any one of claims 6 to 9 , wherein the thermosetting resin composition has a spiral flow length of 50 cm or more. Claims 6 to 10 , wherein the cured product obtained by heating the thermosetting resin composition at 200° C. for 90 minutes has a dielectric loss tangent (tan δ) of 0.04 or less at 25 GHz by a cavity resonator method. The thermosetting resin composition according to any one of the above . (A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
A thermosetting resin composition comprising,
The thermosetting resin (A) is an epoxy resin (A1),
The epoxy resin (A1) is a bisphenol A type epoxy resin, a bisphenol F type epoxy resin, a naphthalene type epoxy resin, a dicyclopentadiene type epoxy resin, a glycidylamine type epoxy resin, a naphthol aralkyl type epoxy resin, and a phenol aralkyl type epoxy resin. At least one species selected from the group consisting of
The curing agent (B) includes an active ester curing agent (B1) having a structure represented by the general formula (1) , or the active ester curing agent (B1) and a phenol curing agent (B2),
The high dielectric constant filler (C) is calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, zircon titanate. The thermosetting resin composition according to claim 1, comprising at least one selected from calcium acid, lead zirconate titanate, barium magnesium niobate, and calcium zirconate. The thermosetting resin composition according to claim 12 , wherein the high dielectric constant filler (C) contains at least one selected from calcium titanate, strontium titanate, and magnesium titanate. The thermosetting resin composition according to claim 12 or 13 , wherein the high dielectric constant filler (C) is contained in an amount of 40% by mass or more in 100% by mass of the thermosetting resin composition. (A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
The thermosetting resin (A) is an epoxy resin (A1),
The epoxy resin (A1) contains a naphthol aralkyl type epoxy resin,
The curing agent (B) includes an active ester curing agent (B1) having a structure represented by the general formula (1) , or the active ester curing agent (B1) and a phenol curing agent (B2),
The high dielectric constant filler (C) is calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, zircon titanate. The thermosetting resin composition according to claim 1, comprising at least one selected from calcium acid, lead zirconate titanate, barium magnesium niobate, and calcium zirconate. The thermosetting resin composition according to claim 15 , wherein the naphthol aralkyl epoxy resin has an epoxy equivalent of 250 g/eq or more and 400 g/eq or less. The thermosetting resin composition according to claim 15 or 16 , further comprising a curing catalyst (D). The thermosetting resin composition according to any one of claims 1 to 17 , which is used as a material for forming a microstrip antenna. The thermosetting resin composition according to any one of claims 1 to 17 , which is used as a material for forming a dielectric waveguide. The thermosetting resin composition according to any one of claims 1 to 17 , which is used as a material for forming an electromagnetic wave absorber. A dielectric substrate obtained by curing the thermosetting resin composition according to any one of claims 1 to 17 . A dielectric substrate according to claim 21 ,
a radiation conductor plate provided on one surface of the dielectric substrate;
a ground conductor plate provided on the other surface of the dielectric substrate;
Microstrip antenna. A dielectric substrate,
a radiation conductor plate provided on one surface of the dielectric substrate;
a ground conductor plate provided on the other surface of the dielectric substrate;
a high dielectric material disposed opposite to the radiation conductor plate;
A microstrip antenna comprising:
A microstrip antenna, wherein the high dielectric material is constituted by the dielectric substrate according to claim 21 .

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