WO2022202804A1

WO2022202804A1 - Thermosetting resin composition, dielectric substrate, and microstrip antenna

Info

Publication number: WO2022202804A1
Application number: PCT/JP2022/013123
Authority: WO
Inventors: 俊次木村; 剛志田中
Original assignee: 住友ベークライト株式会社
Priority date: 2021-03-25
Filing date: 2022-03-22
Publication date: 2022-09-29
Also published as: WO2022202781A1; WO2022202792A1; KR20230160869A; JP7347713B2; JPWO2022202781A1; TW202248273A; KR20230161473A; JP2024014929A; JP7351434B2; JP2023164926A; TW202248340A; KR20230160342A; JPWO2022202804A1; TW202248274A; JPWO2022202792A1; JP7396534B2; JP2023179419A

Abstract

A thermosetting resin composition of the present invention comprises a thermosetting resin (A) and a high-dielectric constant filler (C). The high-dielectric constant filler (C) includes at least one selected from calcium titanate, strontium titanate, magnesium titanate, magnesium zirconate, strontium zirconate, bismuth zirconate, bismuth titanate, zirconium titanate, zinc titanate, barium zirconate, calcium zirconate titanate, lead zirconate titanate, barium magnesium niobate, and calcium zirconate.

Description

Thermosetting resin composition, dielectric substrate, and microstrip antenna

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

In recent years, wireless communication has become faster, and there is a demand for higher performance and smaller size for the communication equipment used. Furthermore, in recent years, the capacity of wireless communication has increased rapidly, and along with this, the frequency band and frequency used for transmission signals are rapidly increasing. Therefore, the frequency band used by communication devices cannot be handled by the conventionally used 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 mounted on communication devices.

Communication equipment can be made even more compact by increasing the dielectric constant of the antenna material (dielectric substrate) incorporated inside the communication equipment. Further, when the dielectric loss tangent of the dielectric substrate becomes small, the loss becomes low, which is advantageous for increasing the frequency. Therefore, if a dielectric substrate with a high dielectric constant and a small dielectric loss tangent can be used, it is possible to increase the frequency, shorten the circuit, and reduce the size of communication equipment.

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

Patent Document 2 discloses a resin composition containing a siloxane-modified polyamideimide resin, a high dielectric constant filler, and an epoxy resin, and having a cured product with a dielectric constant of 15 or more at 25°C and 1 MHz. Examples of the document describe an example of using barium titanate 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 describes that this resin composition can be used as a high dielectric constant insulating material for electronic parts used in a high frequency range and as a high dielectric constant insulating material for fingerprint sensors. Examples of the literature describe an example of using barium titanate as the dielectric powder.

Patent document 4 contains an epoxy resin, a curing agent, and an inorganic filler containing predetermined amounts of calcium titanate particles and strontium titanate particles, and the inorganic filler consists of silica particles and alumina particles. A molding resin composition further containing at least one selected from the group and used for encapsulating electronic parts in high-frequency devices is disclosed.

Japanese Patent Application Laid-Open No. 2018-41998 JP-A-2004-315653 JP 2020-105523 A Japanese Patent No. 6870778

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

The present inventors have found that a dielectric substrate having 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.

The first invention (claims 1 to 8 at the time of filing) can be shown in the following [1] to [8].
[1] (A) 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 phenol novolac, and a phenol The thermosetting resin composition according to [2], which contains at least one selected from active ester curing agents containing benzoylated novolaks.
[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 linked 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, 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 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 measured under the following conditions.
(conditions)
Using a low-pressure transfer molding machine, the resin composition was injected into a rectangular channel having 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 rate 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 to calculate the minimum pressure when the resin composition flows, and this minimum pressure is defined 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 at 18 GHz by a cavity resonator method. A thermosetting resin composition having a dielectric constant at 10 or more and a dielectric loss tangent (tan δ) of 0.04 or less.

The second invention (claims 9 to 16 at the time of filing) can be shown in the following [9] to [16].
[9] (A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
A thermosetting resin composition, wherein 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 heat according to [9] or [10], 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. A curable resin composition.
[12] The curing agent (B) contains 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 of phenol novolak. 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 the general formula (B), Ar is a substituted or unsubstituted arylene group, 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 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 spiral flow length of the thermosetting resin composition is 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, the cured product of which has a dielectric loss tangent (tan δ) at 25 GHz measured by a cavity resonator method of 0.04 or less.

The third invention (claims 17 to 21 at the time of filing) can be shown in the following [17] to [21].
[17] (A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
A thermosetting resin composition comprising
(A) the thermosetting resin 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 selected from the group consisting of
The curing agent (B) comprises an active ester curing agent (B1) and/or a phenolic 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], 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. 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 phenol novolak, and a phenol The thermosetting resin composition according to any one of [17] to [19], which contains at least one selected from active ester curing agents containing benzoylated novolaks.
[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 the general formula (B), Ar is a substituted or unsubstituted arylene group, 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 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 at the time of filing) can be shown in the following [22] to [25].
[22] (A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
(A) the thermosetting resin is an epoxy resin (A1),
The epoxy resin (A1) contains a naphthol aralkyl 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 epoxy equivalent of the naphthol aralkyl epoxy resin is 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 phenolic 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 at the time of filing) can be used for applications 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;
a microstrip antenna.
[31] 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 facing the radiation conductor plate;
A microstrip antenna comprising:
A microstrip antenna, wherein the high dielectric is composed of the dielectric substrate described in [29].

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

1 is a top perspective view showing a microstrip antenna of this embodiment; FIG. FIG. 4 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 at the time of filing) will be described based on the first embodiment with reference to the drawings,
The second invention (claims 9 to 16, 26 to 31 at the time of filing) will be described based on the second embodiment with reference to the drawings,
The third invention (claims 17 to 21 and 26 to 31 at the time of filing) will be described based on the third embodiment with reference to the drawings,
A fourth invention (claims 22 to 25 and 26 to 31 at the time of filing) will be described based on a fourth embodiment with reference to the drawings.
In addition, in all the drawings, the same constituent elements are denoted by the same reference numerals, and the description thereof will be omitted as appropriate. Also, 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
It contains a thermosetting resin (A) and a high dielectric constant filler (C).
Each component is described below.

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

For the epoxy resin (A1), any monomer, oligomer, or polymer having two or more epoxy groups in one molecule can be used, and its molecular weight and molecular structure 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, a tetramethylbisphenol F type epoxy resin; a stilbene type epoxy resin; a phenol novolac type epoxy resin; Novolak type epoxy resins such as cresol novolak type epoxy resins; Polyfunctional epoxy resins such as trisphenol type epoxy resins exemplified by triphenolmethane type epoxy resins and alkyl-modified triphenolmethane type epoxy resins; Phenol aralkyls 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 a naphthol aralkyl type epoxy resin having a biphenylene skeleton; Naphthol-type epoxy resins such as epoxy resins obtained by glycidyl-etherifying dimers; Triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; Aribashi 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. From the same viewpoint, the epoxy resin preferably contains one or more selected from the group consisting of ortho-cresol novolak-type epoxy resins, phenol aralkyl-type epoxy resins having a biphenylene skeleton, and triphenylmethane-type epoxy resins. More preferably, it contains one or more selected from the group consisting of ortho-cresol novolak-type epoxy resins and phenol aralkyl-type epoxy resins having a biphenylene skeleton.

From the viewpoint of the effect of the present invention, the epoxy resin (A1) is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more relative to the entire thermosetting resin composition. can be done. Also, the epoxy resin (A1) can typically be contained in an amount of 20% by mass or less, more preferably 18% by mass or less, and even more preferably 15% by mass or less.

[High dielectric constant filler (C)]
In the present 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, and the like can be mentioned, and one or more selected from these can be used.
Since the thermosetting resin composition of the present embodiment contains these high dielectric constant fillers (C), it is excellent in high dielectric constant and low dielectric loss tangent, and is excellent in these effects even 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, flaky, etc., and high dielectric constant fillers of these shapes can be used at any ratio. The average particle size 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, still more preferably 0, from the viewpoint of the effects of the present invention and fluidity/fillability. .5 μm or more and 10 μm or less.

The 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, and still more preferably 40% by mass with respect to the entire thermosetting resin composition. % to 60% by mass. When the addition amount of the high dielectric constant filler (C) is within the above range, the dielectric constant of the resulting cured product is further lowered, and the production of molded articles is also excellent.

[Active ester curing agent (B1)]
The thermosetting resin composition of the present embodiment can further contain an active ester curing agent (B1).
A compound having one or more active ester groups in one molecule can be used as the active ester curing agent (B1). Among them, the active ester curing agent (B1) contains two highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Compounds having one or more 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 phenol novolac, and a phenol Active ester curatives including benzoylated novolacs can be included and at least one can be included. Among them, an active ester curing agent containing a naphthalene structure and an active ester curing agent containing a dicyclopentadiene type diphenol structure are more preferable. "Dicyclopentadiene-type diphenol structure" represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

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

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. Substituents of the substituted arylene group include alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, phenyl groups and aralkyl groups.
Y is a single bond, a substituted or unsubstituted linear alkylene group having 1 to 6 carbon atoms, or a substituted or unsubstituted cyclic alkylene group having 3 to 6 carbon atoms, or a substituted or unsubstituted divalent is an aromatic hydrocarbon group, an ether bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group. Substituents for the aforementioned groups include alkyl groups having 1 to 4 carbon atoms, alkoxy groups having 1 to 4 carbon atoms, phenyl groups, aralkyl groups 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, an optionally substituted 9,9-fluorenylene group, and the like.
n is an integer of 0-4, preferably 0 or 1;
Specifically, B is a structure represented by the following general formula (B1) or the following general formula (B2).

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

A is a substituted or unsubstituted arylene group linked 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.

The thermosetting resin composition of the present embodiment contains a specific active ester curing agent, so that the resulting cured product can have excellent dielectric properties and excellent 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 secondary hydroxyl groups. 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 formula (B) above is preferably at least one selected from the following formulas (B-1) to (B-6).

In formulas (B-1) to (B-6),
each R ¹ is 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;

Each R ² is 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, ether a bond, a carbonyl group, a carbonyloxy group, a sulfide group, or a sulfone group,
n is an integer of 0-4 and p is an integer of 1-4.

Since the structures represented by the above formulas (B-1) to (B-6) are all highly oriented structures, when using an active ester curing agent containing this, 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 encapsulating material.
Among them, from the viewpoint of low dielectric loss tangent, an active ester curing agent having a structure represented by formula (B-2), formula (B-3) or formula (B-5) is preferable, and further formula (B-2) n is 0, a structure in which X in formula (B-3) is an ether bond, or an active ester having a structure in which two carbonyloxy groups are at the 4,4′-positions in formula (B-5) Curing agents are more preferred. Moreover, all R ¹ in each formula are preferably hydrogen atoms.

“Ar′” in formula (1) is an aryl group, such as a 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 and the like. Among them, a 1-naphthyl group or a 2-naphthyl group is preferable because a cured product having 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 linked via an aliphatic cyclic hydrocarbon group, such an arylene group Examples thereof 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.

The unsaturated aliphatic cyclic hydrocarbon compounds containing two double bonds in one molecule are, for example, dicyclopentadiene, cyclopentadiene oligomers, tetrahydroindene, 4-vinylcyclohexene, 5-vinyl-2-norbornene. , limonene, etc., and these may be used alone or in combination of two or more. Among these, dicyclopentadiene is preferable because a cured product having excellent heat resistance can be obtained. Since dicyclopentadiene is contained in petroleum distillates, industrial dicyclopentadiene may contain cyclopentadiene polymers and other aliphatic or aromatic diene compounds as impurities. However, considering performance such as heat resistance, curability and moldability, it is desirable to use dicyclopentadiene products with a 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, 1-naphthol, 2-naphthol, 1,4-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene and the like, each alone You may use and you may use two or more types together. Among these, phenol is preferable because it is an active ester curing agent having high curability and excellent dielectric properties in the 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 low dielectric loss tangent in the cured product and is excellent in adhesion to an insert.

In formula (A),
each R ³ is 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), Especially 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, k is a repeating unit 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, k is a repeating unit 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, k is a repeating unit is the average of 0.25 to 3.5.

The active ester curing agent (B1) used in the present invention comprises a phenolic compound (a) having a structure in which a plurality of aryl groups having phenolic hydroxyl groups are connected via an aliphatic cyclic hydrocarbon group, and an aromatic nucleus-containing dicarboxylic acid. 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 appropriately adjusted according to the desired molecular design. Among them, since an active ester curing agent with higher curability can be obtained, the phenolic compound (a ) has a phenolic hydroxyl group in the range of 0.25 to 0.90 mol, and the hydroxyl group in the aromatic monohydroxy compound (c) has a range of 0.10 to 0.75 mol. It is preferable to use raw materials, and 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 0.5 mol. It is more preferable to use each raw material in a ratio of 25 to 0.50 mol.

In addition, the functional group equivalent of the active ester curing agent (B1) is excellent in curability when the sum of the arylcarbonyloxy groups and phenolic hydroxyl groups in the resin structure is taken as the total number of functional groups in the resin, and the dielectric constant and dielectric loss tangent are good. It is preferably in the range of 200 g/eq or more and 230 g/eq or less, more preferably 210 g/eq or more and 220 g/eq or less, since a low cured product can be obtained.

In the thermosetting resin composition of the present embodiment, the blending amount of the active ester curing agent (B1) and the epoxy resin (A1) is excellent in curability, and a cured product with a low dielectric loss tangent can be obtained. It is preferable that the ratio of the epoxy groups in the epoxy resin (A1) is 0.8 to 1.2 equivalents with respect to the total equivalent of active groups in the curing agent (B1). Here, the active groups in the active ester curing agent (B1) refer to arylcarbonyloxy groups and phenolic hydroxyl groups 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, relative to the entire thermosetting resin composition. It is used in an amount of 10 mass % or less, more preferably 1.0 mass % or more and 7 mass % or less.
By containing the specific active ester curing agent in the above range, the obtained cured product can have more excellent dielectric properties and is further excellent in low dielectric loss tangent.

By using a combination of the active ester curing agent (B1) and the above-described high dielectric constant filler (C), the resin blocker of the present embodiment is excellent in high dielectric constant and low dielectric loss tangent, even in a high frequency band. 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, relative to 100 parts by mass of the 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.

In addition, as described in JP-A-2020-90615, the present applicant has proposed 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 effect of the combination of the active ester curing agent and the epoxy resin is also different in that it has a high dielectric constant and is excellent in high dielectric constant and low dielectric loss tangent in the high frequency band. ing.

[Other curing agents]
The thermosetting resin composition of this embodiment can further contain a curing agent other than the active ester curing agent (B1).
Curing agents include, for example, diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complexes, amine compounds such as guanidine derivatives; dicyandiamide, dimer of linolenic acid and ethylenediamine. Amide compounds such as polyamide resins synthesized from; , Acid anhydrides such as methylhexahydrophthalic anhydride; 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 novolak resin, biphenyl-modified phenolic resin (polyhydric phenol compound with phenolic nucleus linked by bismethylene group), biphenyl-modified Polyhydric phenol compounds such as naphthol resin (polyhydric naphthol compound in which phenol nucleus is linked by bismethylene group), aminotriazine-modified phenol resin (polyhydric phenol compound in which phenol nucleus is linked by melamine, benzoguanamine, etc.), Phenolic aralkyl resins are preferred.

When another curing agent is used together with the active ester curing agent (B1), the 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, based on the thermosetting resin. 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 or the like. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin (A), and known curing catalysts can be used.

Specifically, phosphorus atom-containing compounds such as organic phosphines, tetrasubstituted phosphonium compounds, phosphobetaine compounds, adducts of phosphine compounds and quinone compounds, adducts of phosphonium compounds and silane compounds; 2-methylimidazole, 2- imidazoles such as phenylimidazole (imidazole-based curing accelerators); 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 curability and obtaining a magnetic material having excellent mechanical strength such as bending strength, it is preferable to contain a phosphorus atom-containing compound, such as a tetra-substituted phosphonium compound, a phosphobetaine compound, a phosphine compound and a quinone compound. It is more preferable to include latent compounds such as adducts of phosphonium compounds and silane compounds, tetrasubstituted phosphonium compounds, adducts of phosphine compounds and quinone compounds, and adducts of phosphonium compounds and silane compounds. Adducts are particularly preferred.

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

Examples of organic phosphines 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 tetra-substituted phosphonium compounds 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 on an 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 on an aromatic ring.
x and y are 1 to 3, z is 0 to 3, and x=y.

A compound represented by the general formula (6) is obtained, for example, as follows.
First, a tetra-substituted phosphonium halide, an aromatic organic acid and a base are mixed in an organic solvent and uniformly mixed to generate an aromatic organic acid anion in the solution system. Water is then added to precipitate the compound represented by general formula (6). In the compound represented by the 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 the anion of the phenol. Examples of the phenols include monocyclic phenols such as phenol, cresol, resorcin and catechol; condensed polycyclic phenols such as naphthol, dihydroxynaphthalene and anthraquinol; bisphenols such as bisphenol A, bisphenol F and bisphenol S; Examples include polycyclic phenols such as phenylphenol and biphenol.

Examples of phosphobetaine compounds include compounds 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.

A compound represented by the general formula (7) is obtained, for example, as follows.
First, the triaromatic-substituted phosphine, which is the third phosphine, is brought into contact with a diazonium salt to substitute the diazonium group of the triaromatic-substituted phosphine with the diazonium salt.

Examples of adducts of phosphine compounds and quinone compounds include compounds represented by the following general formula (8).

In general formula (8),
P represents a phosphorus atom.
R ¹⁰ , R ¹¹ and R ¹² each 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.

R ¹³ , R ¹⁴ and R ¹⁵ each represent a hydrogen atom or a hydrocarbon group having 1 to 12 carbon atoms and may be the same or different, and R ¹⁴ and R ¹⁵ combine to form a cyclic structure. may

The phosphine compound used for the adduct of the phosphine compound and the quinone compound includes, for example, triphenylphosphine, tris(alkylphenyl)phosphine, tris(alkoxyphenyl)phosphine, trinaphthylphosphine, tris(benzyl)phosphine and the like. Substituents or those in which a substituent such as an alkyl group or an alkoxyl group is present are preferred, and examples of substituents 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.

The quinone compound used for the adduct of the phosphine compound and the quinone compound includes benzoquinone and anthraquinones, among which p-benzoquinone is preferable from the viewpoint of storage stability.

As a method for producing the adduct of the phosphine compound and the quinone compound, the adduct can be obtained by contacting and mixing in a solvent in which both the organic tertiary phosphine and the benzoquinones can be dissolved. As the solvent, ketones such as acetone and methyl ethyl ketone, which have low solubility in the adduct, are preferred. However, it is not limited to this.

Compounds represented by the general formula (8) in which 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, namely 1, A compound obtained by adding 4-benzoquinone and triphenylphosphine is preferable in that it lowers the thermal elastic modulus of the cured product of the encapsulating resin composition.

Examples of adducts of phosphonium compounds and silane compounds include compounds 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 aromatic or heterocyclic organic group or an aliphatic group, and may be the same or different.
^R20 is an organic group that bonds with groups ^Y2 and ^Y3 .
^R21 is an organic group that bonds with groups ^Y4 and ^Y5 .

Y2 and Y3 ^each represent a group formed by releasing protons from a proton ^- donating group ^, and the groups ^Y2 and Y3 in the same molecule combine with silicon atoms to form a chelate structure.

Y4 and ^Y5 represent a group formed by releasing protons from a proton ^- donating group, and the groups Y4 and ^Y5 in the ^same molecule bind to silicon atoms to form a chelate structure.
R ²⁰ and R ²¹ may be the same or different, and Y ² , Y ³ , Y ⁴ and Y ⁵ may be the same or different.
Z1 is an organic group having an aromatic or heterocyclic ring, 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 and methyl group. , ethyl group, n-butyl group, n-octyl group and cyclohexyl group. , an aromatic group having a substituent such as a hydroxyl group or an unsubstituted aromatic group is more preferable.

In general formula (9), ^R20 is an organic group that bonds with ^Y2 and ^Y3 . Likewise, R ²¹ is an organic group that bonds with groups Y ⁴ and Y ⁵ . Y2 and Y3 ^are groups formed by proton ^- releasing proton ^- donating groups ^, and the groups Y2 and Y3 in the same molecule bond with silicon atoms to form a chelate structure. Similarly, Y4 and ^Y5 are groups in which proton ^- donating groups release protons, and groups Y4 and ^Y5 in the ^same molecule bond with silicon atoms to form a chelate structure. The groups R ²⁰ and R ²¹ may be the same or different, and the groups Y ² , Y ³ , Y ⁴ and Y5 may be the same or different. In the groups represented by -Y ² -R ²⁰ -Y ³ - and Y ⁴ -R ²¹ -Y ⁵ - in the general formula (9), the proton donor releases two protons The proton donor is preferably an organic acid having at least two carboxyl groups or hydroxyl groups in the molecule, and furthermore, the adjacent carbon atoms constituting the aromatic ring have a carboxyl group or a hydroxyl group. An aromatic compound having at least two hydroxyl groups is preferable, and an aromatic compound having at least two hydroxyl groups on adjacent carbon atoms constituting an aromatic ring is more preferable. 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, and among these, catechol, 1,2-dihydroxynaphthalene and 2,3-dihydroxynaphthalene are more preferred.

Z ¹ in general formula (9) represents an organic group or aliphatic group having an aromatic or heterocyclic ring, specific examples of which include a methyl group, an ethyl group, a propyl group, a butyl group and a hexyl group. and aliphatic hydrocarbon groups such as octyl group, aromatic hydrocarbon groups such as phenyl group, benzyl group, naphthyl group and biphenyl group, glycidyloxy groups such as glycidyloxypropyl group, mercaptopropyl group, aminopropyl group, mercapto groups, alkyl groups having amino groups, and reactive substituents such as vinyl groups. 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 by dissolving a tetrasubstituted phosphonium halide such as tetraphenylphosphonium bromide in methanol is added dropwise thereto while stirring at room temperature, crystals are precipitated. Precipitated crystals are filtered, washed with water and dried in a vacuum to obtain an adduct of a phosphonium compound and a silane compound.

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, relative to the entire thermosetting resin composition. By setting it to such a numerical range, a sufficient curing acceleration 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, fosterite, steatite, spinel, Examples include powders of mullite, titania, etc., beads obtained by spheroidizing these powders, glass fibers, and the like. These inorganic fillers may be used alone or in combination of two or more. Among the above inorganic fillers, fused silica is preferable from the viewpoint of reducing the coefficient of linear expansion, and alumina is preferable from the viewpoint of high thermal conductivity. is preferred.

The amount of the inorganic filler other than the high dielectric constant filler is preferably 15% by mass or more, 60 % by mass or less, more preferably 20% by mass or more and 50% by mass or less. If it is the said range, it will be excellent in thermal-expansion reduction and moldability.

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

[Thermosetting resin composition]
The thermosetting resin composition of this embodiment can be produced by uniformly mixing the components described above. Examples of the production method include a method of sufficiently mixing raw materials in a predetermined amount with a mixer or the like, melt-kneading the mixture with a mixing roll, kneader, extruder or the like, and then cooling and pulverizing the mixture. The resulting thermosetting resin composition may, if desired, be tableted to a size and mass that are suitable for molding conditions.

The thermosetting resin composition of the present 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.), a mold temperature of 175 ° C. is injected 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.

In addition, the thermosetting resin composition of the present embodiment has a rectangular pressure of 0.1 MPa or more, preferably 0.15 MPa or more, more preferably 0.20 MPa or more, measured under the following conditions.
Rectangular pressure is a parameter of melt viscosity, and the smaller the numerical value, the lower the melt viscosity. The thermosetting resin composition of the present embodiment has a rectangular pressure within the above range, and is therefore excellent in mold filling properties during molding.

(conditions)
Using a low-pressure transfer molding machine, the thermosetting resin composition was injected into a rectangular flow path 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, the change in pressure over time is measured with a pressure sensor embedded at a position 25 mm from the upstream end of the flow channel, the minimum pressure at the time of flow of the thermosetting resin composition is calculated, and this minimum pressure is measured as a rectangular pressure. and

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

Since the cured product obtained from the resin composition of the present embodiment is excellent in high dielectric constant and low dielectric loss tangent in a high frequency band, it is possible to increase the frequency and shorten the circuit and reduce the size of communication equipment. 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 contains a thermosetting resin (A), a curing agent (B), and a high dielectric constant filler (C).
Each component is described below.

[Thermosetting resin (A)]
In the present embodiment, the thermosetting resin (A) is a kind selected from cyanate resins, epoxy resins, resins having two or more radically polymerizable carbon-carbon double bonds in one molecule, and maleimide resins. Alternatively, two or more kinds can be used. Among these, it is particularly preferable to contain the epoxy resin (A1) from the viewpoint of the effects of the present invention.
Preferred specific examples of the epoxy resin (A1) in the present embodiment include those described for the epoxy resin (A1) in the above-described 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, relative to the entire thermosetting resin composition. Also, 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 the present embodiment, the curing agent (B) may be a known curing agent within the scope of the effects of the present invention. can be done.

(Active ester curing agent (B1))
A compound having one or more active ester groups in one molecule can be used as the active ester curing agent (B1). Among them, active ester curing agents include phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds, etc., which have two or more ester groups with high reaction activity per molecule. Compounds are preferred.

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

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

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 total resin composition. Hereafter, 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 more excellent dielectric properties and is further excellent in low dielectric loss tangent.

The resin composition of the present embodiment is excellent in low dielectric loss tangent by using a combination of the active ester curing agent (B1) and the high dielectric constant filler (C) described later, and exhibits these effects even in a high frequency band. 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, relative to 100 parts by mass of the 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.

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

(Phenolic curing agent (B2))
Phenol curing agents (B2) include phenol novolak resins, cresol novolac resins, aromatic hydrocarbon formaldehyde resin-modified phenol resins, dicyclopentadiene phenol addition type resins, phenol aralkyl resins, naphthol aralkyl resins, trimethylolmethane resins, tetraphenylene resins. Roll ethane resin, naphthol novolac resin, naphthol-phenol co-condensed novolac resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (polyhydric phenol compound in which phenol nucleus is linked by bismethylene group), biphenyl-modified naphthol resin (bismethylene polyhydric phenol compounds such as polyhydric naphthol compounds in which phenol nuclei are linked by groups) and aminotriazine-modified phenol resins (polyhydric phenol compounds in which phenol nuclei are linked by 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 with respect to 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 the present 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, based on the total 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 less and 7% by mass or less.
By including the specific phenolic 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 the present embodiment can contain curing agents other than the active ester curing agent (B1) and the phenolic curing agent (B2).
Other curing agents include, for example, diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, imidazole, BF ₃ -amine complex, amine compounds such as guanidine derivatives; dicyandiamide, dimer of linolenic acid. Amide compounds such as polyamide resins synthesized from and ethylenediamine; acid anhydrides such as phthalic acid and methylhexahydrophthalic anhydride;

[High dielectric constant filler (C)]
In this embodiment, the high dielectric constant filler (C) comprises magnesium titanate.
Since the thermosetting resin composition of the present embodiment contains magnesium titanate as the high dielectric constant filler (C), it has an excellent low dielectric loss tangent and exhibits excellent effects even in a high frequency band.
The high dielectric constant filler (C) preferably contains magnesium titanate and calcium titanate. As a result, the low dielectric loss tangent is further improved, and the effect is further improved 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, and calcium zirconate titanate. , lead zirconate titanate, barium magnesium niobate, and calcium zirconate.

The shape of the high dielectric constant filler (C) is granular, amorphous, flaky, etc., and these shapes of the high dielectric constant filler (C) can be used at any ratio. The average particle size 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, and further preferably It is preferably 0.5 μm or more and 10 μm or less.

The amount 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, more preferably 100% by mass of the resin composition. The range is 40% by mass or more and 85% by mass or less. When the amount of the high-dielectric-constant filler (C) is within the above range, the resulting cured product has a lower dielectric loss tangent and is excellent in the production of molded articles.
When the high dielectric constant filler (C) consists of only magnesium titanate, the content of magnesium titanate is preferably 30% by mass or more and 90% by mass or less, more preferably 35% by mass in 100% by mass of the resin composition. It is in the range of 40% by mass or more and 85% by mass or less, more preferably 40% by mass or more and 85% by mass or less.
When the high dielectric constant filler (C) is composed of magnesium titanate and calcium titanate, the total amount of these is preferably 30% by mass or more and 90% by mass or less, or more, in 100% by mass of the resin composition. The range 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 or the like. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin (A), and known curing catalysts can be used.
Preferred specific examples of the curing catalyst (D) include those described for the curing catalyst (D) in the first embodiment, and can be produced in the same manner.

When using a 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 and 0 .8% by mass or less. By setting it to such a numerical range, a sufficient curing acceleration effect can be obtained without excessively deteriorating other performances.

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

The amount of the inorganic filler other than the high dielectric constant filler (C) is preferably 15% by mass or more, 60 % by mass or less, more preferably 20% by mass or more and 50% by mass or less. If it is the said range, it will be excellent in thermal-expansion reduction and moldability.

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

(Active ester curing agent (B1))
selected from active ester curing agents containing a dicyclopentadiene type diphenol structure, active ester curing agents containing a naphthalene structure, active ester curing agents containing acetylated phenol novolacs, and active ester curing agents containing benzoylated phenol novolacs; contains at least one
Preferably, it contains 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.
More preferably, it is an active ester curing agent having a structure represented by the general formula (1).
The thermosetting resin (A) and the curing agent (B) containing the active ester curing agent (B1) can be combined arbitrarily.

(Phenolic 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, tetraphenylol ethane resin, naphthol novolac resin, naphthol - Phenol co-condensed novolac 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 (polyphenol compounds with phenol nuclei linked by bismethylene groups) polyvalent naphthol compounds) and aminotriazine-modified phenolic resins (polyhydric phenol compounds in which the phenol nucleus is 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 the present embodiment is
The thermosetting resin (A) can be contained in an amount of preferably 5% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 15% by mass or less in 100% by mass of the composition,
Active ester curing agent (B1) and / or phenolic curing agent (B2) 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, more preferably 1.0% by mass or more and 7% by mass or less,
10% by mass or more and 90% by mass or less, more preferably 20% by mass or more and 88% by mass or less, and still more preferably 40% by mass or more and 85% by mass of the high dielectric constant filler (C) in 100% by mass of the composition It can be included in the following amounts:

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

The thermosetting resin composition of this embodiment can be produced by uniformly mixing the components described above. Examples of the production method include a method of sufficiently mixing raw materials in a predetermined amount with a mixer or the like, melt-kneading the mixture with a mixing roll, kneader, extruder or the like, and then cooling and pulverizing the mixture. The resulting thermosetting resin composition may, if desired, be tableted to a size and mass that are suitable for molding conditions.

(conditions)
Using a low-pressure transfer molding machine, the resin composition was injected into a rectangular channel having 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 rate 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 to calculate the minimum pressure when the resin composition flows, and this minimum pressure is defined as the rectangular pressure.

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

The cured product obtained from the thermosetting resin composition of the present embodiment is excellent in low dielectric loss tangent in the high frequency band, so it can be used for high frequencies, and is 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, and the like.

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

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

[Epoxy resin (A1)]
Examples of the epoxy resin (A1) include bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, glycidylamine type epoxy resin, naphthol aralkyl type epoxy resin, phenol aralkyl type epoxy resin, and the like. and includes at least one selected from these. The phenol aralkyl epoxy resin does not include a biphenylene skeleton-containing phenol aralkyl epoxy resin.
In the present embodiment, the epoxy resin (A1) is preferably a naphthol aralkyl type epoxy resin or a dicyclopentadiene type epoxy resin, 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 type 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, relative to 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 phenolic curing agent (B2).
(Active ester curing agent (B1))
A compound having one or more active ester groups in one molecule can be used as the active ester curing agent (B1). Among them, active ester curing agents include phenol esters, thiophenol esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds, etc., which have two or more ester groups with high reaction activity per molecule. Compounds are preferred.
In the present embodiment, a dielectric excellent in high dielectric constant and low dielectric loss tangent by including 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.

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

In the thermosetting resin composition of the present embodiment, the blending amount of the active ester curing agent (B1) and the epoxy resin (A1) is excellent in curability, and a cured product with a low dielectric loss tangent can be obtained. It is preferable that the ratio of the epoxy groups in the epoxy resin (A1) is 0.8 to 1.2 equivalents with respect to the total equivalent of active groups in the curing agent. Here, the active group in the active ester curing agent refers to an arylcarbonyloxy group and a phenolic hydroxyl group 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, relative to the entire thermosetting resin composition. It is used in an amount of 10 mass % or less, more preferably 1.0 mass % or more and 7 mass % or less.
By containing the specific active ester curing agent (B1) in the above range, the obtained cured product can have more excellent dielectric properties and is further excellent in low dielectric loss tangent.

The resin composition of the present embodiment is excellent in high dielectric constant and low dielectric loss tangent by using a combination of the active ester curing agent (B1) and the high dielectric constant filler (C) described later, even in a high frequency band. Excellent in these effects.
From the viewpoint of the above effect, 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, with respect to 100 parts by mass of the high dielectric constant filler (C) described later. 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.

In addition, as described in JP-A-2020-90615, the present applicant has developed a resin composition containing an epoxy resin and a predetermined active ester curing agent for semiconductor sealing applications different from the present invention. is 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 effect of the combination of the active ester curing agent and the epoxy resin is also different in that it has a high dielectric constant and is excellent in high dielectric constant and low dielectric loss tangent in the high frequency band. ing.

The blending amount of the phenol curing agent (B2) is preferably 20% by mass or more and 70% by mass or less with respect to 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 the active ester curing agent (B1) and the phenolic curing agent (B2), the ratio of the content of the phenolic curing agent b to the active ester curing agent a (b (parts by mass) / a (parts by mass )) can be 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 phenolic curing agent (B2) in the above ratio, the obtained 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 phenolic curing agent (B2) is preferably 0.2 mass with respect to the entire thermosetting resin composition. % or more and 15 mass % or less, more preferably 0.5 mass % or more and 10 mass % or less, and still more preferably 1.0 mass % or more and 7 mass % or less.
By including the curing agent (B) in the above range, the obtained cured product can have more excellent dielectric properties and is further excellent in low dielectric loss tangent.

[High dielectric constant filler (C)]
In the present 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 and the like 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 amount of the high dielectric constant filler (C) is preferably 40% by mass or more, more preferably 50% by mass or more, and still 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) is within the above range, the resulting cured product is excellent in high dielectric constant and low dielectric loss tangent, and is also excellent in production of molded articles.

[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 or the like. The curing catalyst (D) is not particularly limited as long as it accelerates the curing reaction of the thermosetting resin, and known curing catalysts can be used.
Preferred specific examples of the curing catalyst (D) include those described for the curing catalyst (D) in the first embodiment, and can be produced in the same manner.

In the present embodiment, by using a combination of an active ester curing agent represented by the general formula (1) and a latent curing catalyst, a magnetic material having excellent moldability and mechanical strength such as bending strength is obtained. can be 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, relative to the entire resin composition. By setting it to such a numerical range, a sufficient curing acceleration effect can be obtained without excessively deteriorating other performances.

The amount of the inorganic filler other than the high dielectric constant filler (C) is preferably 15% by mass with respect to the entire thermosetting resin composition from the viewpoint of moldability, reduction of thermal expansion, and improvement of strength. Above, 60% by mass or less, more preferably 20% by mass or more and 50% by mass or less. If it is the said range, it will be excellent in thermal-expansion reduction and moldability.

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

(Curing agent (B))
Contains an active ester curing agent (B1) and/or a phenolic curing agent (B2).
It preferably contains an active ester curing agent (B1).
(Active ester curing agent (B1))
Active ester curing agent containing dicyclopentadiene type diphenol structure, active ester curing agent containing naphthalene structure, active ester curing agent containing acetylated phenol novolac, and active ester curing agent containing benzoylated phenol novolac at least one selected from 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 It contains at least one selected from barium magnesiumate and calcium zirconate.
Preferably, it contains at least one selected from calcium titanate, strontium titanate, and magnesium titanate.
More preferably, it contains at least one selected from calcium titanate and magnesium titanate.
The epoxy resin (A1), the curing agent (B) containing the active ester curing agent (B1) and/or the phenolic curing agent (B2), and the high dielectric constant filler (C) are each can be combined arbitrarily.

Furthermore, the thermosetting resin composition of the present embodiment is
The epoxy resin (A1) can be contained in an amount of preferably 5% by mass or more and 20% by mass or less, more preferably 10% by mass or more and 15% by mass or less, based on 100% by mass of the composition,
Curing agent (B) 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, still 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 in an amount of preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 60% by mass or more. The upper limit is 80% by mass.

In the present embodiment, by including the epoxy resin (A1), the curing agent (B) containing the active ester curing agent (B1), and the high dielectric constant filler (C) in combination, It is possible to provide a thermosetting resin composition that gives a dielectric substrate excellent in dielectric constant and low dielectric loss tangent.

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

Since the cured product obtained from the thermosetting resin composition of the present embodiment is excellent in high dielectric constant and low dielectric loss tangent in the high frequency band, it is possible to increase the frequency and shorten the circuit and reduce the size of communication equipment. 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, and the like.

<Fourth Embodiment>
The thermosetting resin composition of this embodiment contains an epoxy resin (A1), a curing agent (B), and a high dielectric constant filler (C).
Each component is described below.

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

In general formula (a), each R 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, A hydrogen atom is more preferred. n is an integer of 1-10, preferably an integer of 1-8.

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

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

The melt viscosity of the naphthol aralkyl epoxy resin at 150° C. is 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 epoxy resin of the present embodiment is preferably 100 to 5000, more preferably 300 to 3000, and even more preferably 500 to 2000.

Further, the degree of dispersion (weight average molecular weight Mw/number average molecular weight Mn) of the naphthol aralkyl 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 uniform, which is preferable.

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

The epoxy resin (A1) of the present embodiment can contain other epoxy resins in addition to the naphthol aralkyl type epoxy resin within a range that does not impair the effects of the present invention.
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 and the like. Aralkyl type epoxy resins are preferred.

When the epoxy resin (A1) contains a naphthol aralkyl epoxy resin and other epoxy resins, 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. %, 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, and 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 epoxy resin.

From the viewpoint of the effect of the present invention, the thermosetting resin composition (100% by mass) of the present embodiment preferably contains the epoxy resin (A1) in an amount of 2% by mass or more and 20% by mass or less, more preferably 3% by mass or more and 15% by mass. % 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 phenolic curing agent (B2).

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

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

The resin composition of the present embodiment is excellent in high dielectric constant and low dielectric loss tangent by using a combination of the active ester curing agent (B1) and the high dielectric constant filler (C) described later, even in a high frequency band. Excellent in these effects.
From the viewpoint of the above effect, 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, with respect to 100 parts by mass of the high dielectric constant filler described later. It can be contained in an amount of 3 parts by mass or more and 15 parts by mass or less, more preferably 3 parts by mass or more and 15 parts by mass or less.

(Phenolic 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 novolac resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolac resin, biphenyl-modified phenol resin (polyhydric phenol compound with phenol nucleus linked by bismethylene group), biphenyl-modified naphthol resin (phenol Polyhydric phenol compounds such as polyhydric naphthol compounds with linked nuclei) and aminotriazine-modified phenolic resins (polyhydric phenol compounds with phenolic nuclei 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 with respect to the thermosetting resin. By using the curing agent in an amount within the above range, a resin composition having excellent curability can be obtained.

From the viewpoint of the effect of the present invention, the curing agent (B) of the present embodiment is preferably the active ester curing agent (B1).

[High dielectric constant filler (C)]
In the present 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, and the like 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. More preferably, it is at least one selected from magnesium.

The amount of the high dielectric constant filler (C) is preferably 40% by mass or more, more preferably 50% by mass or more, and still 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 addition amount of the high dielectric constant filler (C) is within the above range, the dielectric constant of the resulting cured product is further lowered, and the production of molded articles is also excellent.

In the present embodiment, by combining the epoxy resin (A1) containing a naphthol aralkyl epoxy resin and a latent curing catalyst, a magnetic material having 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, relative to 100% by mass of the thermosetting resin composition. By setting it to such a numerical range, a sufficient curing acceleration effect can be obtained without excessively deteriorating other performances.

The amount of the inorganic filler other than the high dielectric constant filler is preferably 3% by mass or more with respect to 100% by mass of the thermosetting resin composition, from the viewpoint of moldability, reduction in thermal expansion, and improvement in strength. , 40 mass % or less, more preferably 5 mass % or more and 30 mass % or less, and still more preferably 10 mass % or more and 25 mass % or less. If it is the said range, it will be excellent in thermal-expansion reduction and moldability.

The thermosetting resin composition of the present embodiment contains an epoxy resin (A1), a curing agent (B), and a high dielectric constant filler (C), and the epoxy resin (A1) is a naphthol aralkyl epoxy resin. including.
The thermosetting resin composition of the present embodiment, which contains such components in combination, can provide a dielectric substrate having excellent dielectric properties such as a low dielectric loss tangent, and a microstrip antenna comprising the dielectric substrate. can be provided.

The thermosetting resin composition of this embodiment is
The epoxy resin (A1) in 100% by mass of the composition is 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, still more preferably 5% by mass or more and 12% by mass or less. can contain an amount of
Curing agent (B) 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, still more preferably 1.0% by mass % or more and 7% by mass or less,
The high dielectric constant filler (C) can be contained in an amount of preferably 40% by mass or more, more preferably 50% by mass or more, and still more preferably 60% by mass or more based on 100% by mass of the solid content of the composition. The upper limit is 90% by mass.

In the present embodiment, by including an epoxy resin (A1) containing a naphthol aralkyl epoxy resin, a curing agent (B), and a high dielectric constant filler (C) in combination, high dielectric constant and low dielectric constant It is possible to provide a thermosetting resin composition from which a dielectric substrate having excellent tangent can be obtained.

The gel time of the thermosetting resin composition of the present 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 lower limit or more, the filling property is excellent, and by setting the gel time to the above upper limit or less, moldability is improved.

The thermosetting resin composition of the present embodiment has the following dielectric constant and dielectric loss tangent (tan δ) in a cured product obtained 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 by the cavity resonator method can be 0.04 or less, preferably 0.03 or less, more preferably 0.02 or less, and particularly preferably 0.015 or less.

<Microstrip Antenna>
As shown in FIG. 1, a microstrip antenna 10 of this embodiment includes a dielectric substrate 12 formed by curing the resin composition described above, 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 part of the radiation conductor plate 12 is embedded in the dielectric substrate 12 .

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

The radiation conductor plate 14 includes any one of a metal material, an alloy of metal materials, a hardened metal paste, and a conductive polymer. Metallic materials include copper, silver, palladium, gold, platinum, aluminum, chromium, nickel, cadmium lead, selenium, manganese, tin, vanadium, lithium, cobalt, titanium, and the like. An alloy includes multiple metallic materials. The metal paste contains powder of a metal material kneaded with an organic solvent and a binder. Binders include epoxy resins, polyester resins, polyimide resins, polyamideimide resins, and polyetherimide resins. Conductive polymers include polythiophene-based polymers, polyacetylene-based polymers, polyaniline-based polymers, polypyrrole-based polymers, and the like.

As shown in FIG. 1, the microstrip antenna 10 of this embodiment has a radiation conductor plate 14 having a length L and a width W, and resonates at a frequency where L is an integer multiple of 1/2 wavelength. . When the dielectric substrate 12 having a high dielectric constant is used 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 highly conductive metal such as copper, silver, and gold. The thickness is sufficiently thin with respect to the central operating frequency of the antenna device, and may be about 1/50 to 1/1000 wavelength of the central operating frequency.

Examples of feeding methods for microstrip antennas include direct feeding methods such as rear coaxial feeding and coplanar feeding, and electromagnetic coupling feeding methods such as slot coupling feeding and proximity coupling feeding.

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

In the slot coupling power supply, another dielectric substrate (not shown) is provided so as 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 a slot formed in the ground conductor plate 16 .

In the proximity coupling feeding, the dielectric substrate 12 has a laminated structure, and the dielectric substrate on which the radiation conductor plate 14 is formed and the 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.

2(a) and 2(b) show another mode of microstrip antenna. The same numbers are given to the same configurations as in FIG. 1, and the description thereof is omitted as appropriate.
As shown in FIG. 2A, 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. and a high dielectric substrate (high dielectric) 24 facing the radiation conductor plate 14 . The dielectric substrate 22 and the radiation conductor plate 14 and the high dielectric substrate 24 can be configured to be separated from each other by a predetermined distance with spacers 26 interposed therebetween.
The dielectric substrate 22 is composed of a substrate having a low dielectric constant such as a Teflon substrate.
The high dielectric substrate 24 is composed of a dielectric substrate obtained by curing the resin composition described above.
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.
Further, as shown in a microstrip antenna 20' in FIG. 2B, a structure in which a high dielectric substrate 24 is brought into contact with the upper surface of the radiation conductor plate 14 can be employed.

<Dielectric waveguide>
In this embodiment, the dielectric waveguide comprises a dielectric obtained 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) for transmission.
The conductor film can be made of a metal such as copper, an oxide high-temperature superconductor, or the like.

<Electromagnetic wave absorber>
In this embodiment, the electromagnetic wave absorber has a laminated structure of a support, a resistive film, a dielectric layer, and a reflective layer. The electromagnetic wave absorber can be used as a λ/4 type electromagnetic wave absorber having high electromagnetic wave absorption performance.
A resin base material etc. are mentioned as a support body. The support can protect the resistive film and enhance the durability as a radio wave absorber.
Resistive films 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 examples of the present invention, and various configurations other than those described above can be adopted within the scope that does not impair the effects of the present invention.

EXAMPLES The present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these.
Example A shows an example of the first invention (claims 1 to 8 and 26 to 31 at the time of filing) and the first embodiment.
Example B shows an example of the second invention (claims 9 to 16 and 26 to 31 at the time of filing) and the second embodiment.
Example C shows an example of the third invention (claims 17 to 21 and 26 to 31 at the time of filing) and the third embodiment.
Example D shows an example according to the fourth invention (claims 22 to 25 and 26 to 31 at the time of filing) and the fourth embodiment.

<Example A>
(Examples A1 to A12, Comparative Example A1)
The following raw materials were mixed in a blending amount shown in Table 1 at room temperature using a mixer, and then roll-kneaded at 70 to 100°C. After cooling the obtained kneaded material, the kneaded material was pulverized to obtain a powdery resin composition. Subsequently, tablet-shaped resin composition was obtained by tablet-molding at high pressure.

(High dielectric constant filler)
・ High dielectric constant filler 1: barium titanate (BT-UP2, average particle size 2 μm, manufactured by Nippon Chemical Industry 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 Nippon Kagaku Kogyo Co., Ltd.)

(Inorganic filler)
・ Inorganic filler 1: alumina (K75-1V25F, manufactured by Denka Co., Ltd.)
・Inorganic filler 2: Fused spherical silica (SC-2500-SQ, manufactured by Admatechs)

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

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

(Epoxy resin)
- Epoxy resin 1: biphenylene skeleton-containing phenol aralkyl type 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.)

(curing agent)
・ Curing agent 1: biphenylene skeleton-containing phenol aralkyl type 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)
279.1 g of biphenyl-4,4′-dicarboxylic acid dichloride (moles of acid chloride group: 2.0 mol) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, condenser, fractionating tube, and stirrer. was charged, and the inside of 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 of dicyclopentadiene phenolic resin (number of moles of phenolic hydroxyl groups: 1.33 mol) were charged, and the system was decompressed and replaced with nitrogen to dissolve. rice field. Thereafter, while purging with nitrogen gas, the inside of the system was controlled at 60° C. or less, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, 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 decanter dehydration to obtain an active ester resin in the form of a toluene solution having a non-volatile 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 were hydrogen atoms, Z was a naphthyl group, and 1 was 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was in the range of 0.5 to 1.0 as calculated from the reaction equivalence ratio.

・ Curing agent 3: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
A flask equipped with a thermometer, dropping funnel, condenser, fractionating tube and stirrer was charged with 203.0 g of 1,3-benzenedicarboxylic acid dichloride (moles of acid chloride group: 2.0 mol) and 1338 g of toluene. It was charged, and the inside of 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 of dicyclopentadiene phenolic resin (number of moles of phenolic hydroxyl groups: 1.33 mol) were charged, and the system was decompressed and replaced with nitrogen to dissolve. rice field. Thereafter, while purging with nitrogen gas, the inside of the system was controlled at 60° C. or less, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, 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 decanter dehydration to obtain an active ester resin in the form of a toluene solution having a non-volatile 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 were hydrogen atoms, Z was a naphthyl group, and 1 was 0 in the above formula (1-3). The average value k of repeating units of the active ester resin was in the range of 0.5 to 1.0 as calculated from the reaction equivalent ratio. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of repeating units was 0.5 to 1.0.

(catalyst)
・Catalyst 1: Tetraphenylphosphonium-4,4′-sulfonyldiphenolate ・Catalyst 2: Tetraphenylphosphonium bis(naphthalene-2,3-dioxy)phenylsilicate

(Release agent)
・Releasing agent 1: Glycerin trimontanate (Rekolb WE-4, manufactured by Clariant Japan Co., Ltd.)
・ 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 Industry Co., Ltd.)
・ Silicone 1: dimethylsiloxane-diglycidin 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 the 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 having a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes in a nitrogen atmosphere and hydrofluoric acid treatment (immersed in a 2 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.
A network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies) were used as measuring devices. These devices and a cylindrical cavity resonator (inner diameter φ42 mm, height 30 mm) were set up.
The resonance frequency, 3 dB bandwidth, transmitted power ratio, etc. were measured at a frequency of 18 GHz with and without inserting the test piece into the resonator. Then, by analytically calculating these measurement results with software, the dielectric properties such as dielectric constant (Dk) and dielectric loss tangent (Df) were determined. 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 placed at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and cured. The resin compositions obtained in Examples and Comparative Examples were injected under the condition of 120 seconds, and the flow length was measured.

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

(Molding shrinkage rate)
For each example and comparative example, the molding shrinkage (after ASM) was measured after molding (ASM: as Mold) for the obtained resin composition, and after the molding, main curing was performed to form a dielectric substrate. The molding shrinkage rate (after PMC) was evaluated under heating conditions (PMC: Post Mold Cure) assuming the production of .
First, a test piece prepared 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. Mold shrinkage (after ASM) was obtained according to K6911.
Furthermore, the obtained test piece was heat-treated at 175° C. for 4 hours, and the molding shrinkage (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 linear expansion coefficients (CTE1, CTE2) of the cured resin composition obtained were measured as follows. First, using a low-pressure transfer molding machine (“KTS-15” manufactured by Kotaki Seiki Co., Ltd.), the encapsulating resin composition was injection molded 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. Then, after post-curing the obtained test piece at 175 ° C. for 4 hours, using a thermomechanical analyzer (manufactured by Seiko Electronics Industries Co., Ltd., TMA100), the measurement temperature range is 0 ° C. to 320 ° C., and the heating rate is Measurement was performed under the condition of 5°C/min. From these measurement results, 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 (flexural 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 article having a width of 10 mm, a thickness of 4 mm and a length of 80 mm was obtained. The resulting molded article was then post-cured at 175° C. for 4 hours. This produced a test piece for evaluation of mechanical strength. 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 in accordance with JIS K 6911 at a head speed of 5 mm/min. .

(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 rectangular mold having a width of 13 mm, a thickness of 1 mm, and a length of 175 mm was molded under conditions of a mold temperature of 175°C and an injection rate 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 channel was used to measure the change in pressure over time, and the minimum pressure (MPa) during the flow of the resin composition was measured, which was defined as the rectangular pressure. Rectangular pressure is a parameter of melt viscosity, and a smaller numerical value indicates a lower melt viscosity.

As shown in Table 1, compared with 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 was obtained which was excellent in tangent and also excellent in balance of other physical properties. It was speculated that a microstrip antenna provided with a dielectric substrate obtained by curing the resin composition would enable higher frequencies, shorten circuits, and reduce the size of communication equipment. Furthermore, it is presumed that the desired effects can be obtained in dielectric waveguides and electromagnetic wave absorbers provided with dielectrics (layers) obtained by curing the resin composition.

<Example B>
(Examples B1 to B9)
The following raw materials were mixed in a blending amount shown in Table 2 at room temperature using a mixer, and then roll-kneaded at 70 to 100°C. After cooling the obtained kneaded material, the kneaded material was pulverized to obtain a powdery resin composition. Subsequently, tablet-shaped resin composition was obtained by tablet-molding at 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 Co., Ltd.)
・ Inorganic filler 2: Fused spherical silica (manufactured by Denka Co., Ltd.)

(Epoxy resin)
- Epoxy resin 1: biphenylene skeleton-containing phenol aralkyl type 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)

(curing agent)
・ Curing agent 1: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
279.1 g of biphenyl-4,4′-dicarboxylic acid dichloride (moles of acid chloride group: 2.0 mol) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, condenser, fractionating tube, and stirrer. was charged, and the inside of 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 of dicyclopentadiene phenolic resin (number of moles of phenolic hydroxyl groups: 1.33 mol) were charged, and the system was decompressed and replaced with nitrogen to dissolve. rice field. Thereafter, while purging with nitrogen gas, the inside of the system was controlled at 60° C. or less, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, 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 decanter dehydration to obtain an active ester resin in the form of a toluene solution having a non-volatile 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 were hydrogen atoms, Z was a naphthyl group, and 1 was 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was in the range of 0.5 to 1.0 as calculated from the reaction equivalence ratio.

・ Curing agent 2: Active ester curing agent prepared by the following preparation method (Preparation method of active ester curing agent)
A flask equipped with a thermometer, dropping funnel, condenser, fractionating tube and stirrer was charged with 203.0 g of 1,3-benzenedicarboxylic acid dichloride (moles of acid chloride group: 2.0 mol) and 1338 g of toluene. It was charged, and the inside of 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 of dicyclopentadiene phenolic resin (number of moles of phenolic hydroxyl groups: 1.33 mol) were charged, and the system was decompressed and replaced with nitrogen to dissolve. rice field. Thereafter, while purging with nitrogen gas, the inside of the system was controlled at 60° C. or less, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, 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 decanter dehydration to obtain an active ester resin in the form of a toluene solution having a non-volatile 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 were hydrogen atoms, Z was a naphthyl group, and 1 was 0 in the above formula (1-3). The average value k of repeating units of the active ester resin was in the range of 0.5 to 1.0 as calculated from the reaction equivalent ratio. The obtained active ester resin specifically had a structure represented by the following chemical formula. In the following formula, the average value k of repeating units was 0.5 to 1.0.

(Release agent)
・Releasing agent 1: Glycerin trimontanate (Rekolb WE-4, manufactured by Clariant Japan Co., Ltd.)

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

(Evaluation of permittivity and dielectric loss tangent by cavity resonator method)
First, a test piece was obtained using the 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 having a coating thickness of 12 μm.
This was heated in an oven at 200° C. for 90 minutes in a nitrogen atmosphere and hydrofluoric acid treatment (immersed in a 2 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.
A network analyzer HP8510C, a synthesized sweeper HP83651A, and a test set HP8517B (all manufactured by Agilent Technologies) were used as measuring devices. These devices and a cylindrical cavity resonator (inner diameter φ42 mm, height 30 mm) were set up.
The resonance frequency, 3 dB bandwidth, transmitted power ratio, etc. were measured at a frequency of 25 GHz with and without inserting the test piece into the resonator. Then, by analytically calculating these measurement results with software, the dielectric properties such as dielectric constant (Dk) and dielectric loss tangent (Df) were determined. 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 placed at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and cured. The resin composition obtained in the example was injected under the condition 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 curing was measured while kneading with a spatula.

(Evaluation of mechanical strength (flexural strength/flexural modulus))
Using a low-pressure transfer molding machine ("KTS-30" manufactured by Kotaki Seiki Co., Ltd.), the resin composition of the example is placed in a mold under the 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 article having a width of 10 mm, a thickness of 4 mm and a length of 80 mm was obtained. The resulting molded article was then post-cured at 175° C. for 4 hours. This produced a test piece for evaluation of mechanical strength. 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 in accordance with JIS K 6911 at a head speed of 5 mm/min. .

As shown in Table 2, the thermosetting resin compositions of the examples according to the present invention were excellent in low dielectric loss tangent due to the inclusion of the high dielectric constant filler, particularly due to the inclusion of magnesium titanate. From this, it has been clarified that the thermosetting resin composition of the present invention is 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 blended at room temperature using a mixer in the blending amounts shown in Table 3, and then roll-kneaded at 70 to 100°C. After cooling the obtained kneaded material, the kneaded material was pulverized to obtain a powdery resin composition. Subsequently, tablet-shaped resin composition was obtained by tablet-molding at high pressure.

(Inorganic filler)
・ Inorganic filler 1: Fused spherical silica (manufactured by Denka Co., Ltd.)

(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, with surface treatment, manufactured by Titan Kogyo Co., Ltd.)

(Epoxy resin)
- Epoxy resin 1: biphenylene skeleton-containing phenol aralkyl type 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 weight 238 g / eq, softening point 62 ° C.), manufactured by Mitsui Chemicals)
・ Epoxy resin 6: naphthalene type epoxy resin (EPICLON HP-4770, manufactured by DIC Corporation)
・ 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)

(Curing catalyst)
- Curing catalyst 1: tetraphenylphosphonium-4,4'-sulfonyl diphenolate

(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 rectangular mold having a width of 13 mm, a thickness of 1 mm, and a length of 175 mm was molded under conditions of a mold temperature of 175°C and an injection rate 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 channel was used to measure the change in pressure over time, and the minimum pressure (MPa) during the flow of the resin composition was measured, which was defined as the rectangular pressure. Rectangular pressure is a parameter of melt viscosity, and a smaller numerical value indicates a lower melt viscosity.

From the results of Table 3, according to the thermosetting resin composition of the present invention, by including the epoxy resin (A1), the curing agent (B) and the high dielectric constant filler (C), the specific epoxy resin It has been clarified that a dielectric substrate excellent in a high dielectric constant and a low dielectric loss tangent, in other words, a dielectric substrate excellent in balance of these characteristics can be obtained by using it.

<Example D>
(Examples D1 to D8)
The following raw materials were blended at room temperature using a mixer in the blending amounts shown in Table 4, and then roll-kneaded at 70 to 100°C. After cooling the obtained kneaded material, the kneaded material was pulverized to obtain a powdery resin composition. Subsequently, tablet-shaped resin composition was obtained by tablet-molding at high pressure.

(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)

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

(Epoxy resin)
・ Epoxy resin 1: Biphenylene skeleton-containing phenol aralkyl type 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 .4 Pa s) (product name ESN-475V, manufactured by Nippon Steel Chemical Co., Ltd.)

(curing agent)
- Curing agent 1: an active ester curing agent prepared by the following preparation method (method for preparing an active ester curing agent)
279.1 g of biphenyl-4,4′-dicarboxylic acid dichloride (moles of acid chloride group: 2.0 mol) and 1338 g of toluene were placed in a flask equipped with a thermometer, dropping funnel, condenser, fractionating tube, and stirrer. was charged, and the inside of 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 of dicyclopentadiene phenolic resin (number of moles of phenolic hydroxyl groups: 1.33 mol) were charged, and the system was decompressed and replaced with nitrogen to dissolve. rice field. Thereafter, while purging with nitrogen gas, the inside of the system was controlled at 60° C. or less, and 400 g of a 20% sodium hydroxide aqueous solution was added dropwise over 3 hours. Stirring was then continued under these conditions for 1.0 hour. After completion of the reaction, the mixture was allowed to stand still for liquid separation, and the aqueous layer was removed. Further, 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 decanter dehydration to obtain an active ester resin in the form of a toluene solution having a non-volatile 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 were hydrogen atoms, Z was a naphthyl group, and l was 0 in the above formula (1-1). Furthermore, the average value k of the repeating units was in the range of 0.5 to 1.0 as calculated from the reaction equivalence ratio.

(Release agent)
・Releasing agent 1: glycerin trimontanate (product name: Recolb WE-4, manufactured by Clariant Japan Co., Ltd.)

(silicone compound)
・ Silicone compound 1: dimethylsiloxane-diglycidin 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.)

(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 placed at a mold temperature of 175 ° C., an injection pressure of 6.9 MPa, and cured. The resin composition obtained in the example was injected under the condition of 120 seconds, and the flow length was measured.

As shown in Table 4, the thermosetting resin compositions of the examples according to the present invention were particularly naphthol aralkyl By containing the type epoxy resin, it was excellent in low dielectric loss tangent and had a high dielectric constant. In other words, the thermosetting resin composition of the present invention is excellent in balance between low dielectric loss tangent and high dielectric constant, and the thermosetting resin composition of the present invention forms a material for forming a microstrip antenna, a material for forming a dielectric waveguide, and an electromagnetic wave absorber. It became clear that it is suitably used as a material.

This application is Japanese application No. 2021-051748 filed on March 25, 2021, Japanese application No. 2021-172197 filed on October 21, 2021, filed on December 6, 2021 Japanese application No. 2021-197667, Japanese application No. 2021-197669 filed on December 6, 2021, Japanese application No. 2021-197679 filed on December 6, 2021, 2021 Claiming 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 disclosures thereof is taken 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 void

Claims

(A) 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.
The thermosetting resin composition according to claim 1, further comprising 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 of phenol novolak. 3. The thermosetting resin composition according to claim 2, comprising at least one selected from active ester curing agents containing compounds.
The thermosetting resin composition according to claim 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 linked 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, 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 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 any one of claims 1 to 4, further comprising a curing catalyst (D).
The thermosetting resin composition according to any one of claims 1 to 5, wherein the flow length of the spiral flow of the thermosetting resin composition is 50 cm or more.
The thermosetting resin composition according to any one of claims 1 to 6, 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 having 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 rate 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 to calculate the minimum pressure when the resin composition flows, and this minimum pressure is defined as the rectangular pressure.
A resin composition containing a thermosetting resin (A) and a high dielectric constant filler (C) was cured by heating at 200° C. for 90 minutes. Dielectricity at 18 GHz by cavity resonator method A thermosetting resin composition having a modulus of 10 or more and a dielectric loss tangent (tan δ) of 0.04 or less.
(A) a thermosetting resin;
(B) a curing agent;
(C) a high dielectric constant filler;
2. The thermosetting resin composition according to claim 1, wherein said high dielectric constant filler (C) comprises magnesium titanate.
The thermosetting resin composition according to claim 9, wherein the high dielectric constant filler (C) further contains calcium titanate.
11. The thermosetting resin composition according to claim 9, 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 curing agent (B) contains 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 of phenol novolak. The thermosetting resin composition according to any one of claims 9 to 11, comprising at least one selected from active ester curing agents containing compounds.
The thermosetting resin composition according to claim 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 linked 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, 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 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 any one of claims 9 to 13, further comprising a curing catalyst (D).
The thermosetting resin composition according to any one of claims 9 to 14, wherein the spiral flow length of said thermosetting resin composition is 50 cm or more.
A cured product obtained by heating and curing a thermosetting resin composition containing a thermosetting resin (A), a curing agent (B), and a high dielectric constant filler (C) at 200° C. for 90 minutes. , a thermosetting resin composition having a dielectric loss tangent (tan δ) at 25 GHz by the cavity resonator method of 0.04 or less.
(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 selected from the group consisting of
The curing agent (B) comprises an active ester curing agent (B1) and/or a phenolic 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. 2. 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 17, 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 17 or 18, 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.
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 of phenol novolak. The thermosetting resin composition according to any one of claims 17 to 19, comprising at least one selected from active ester curing agents containing compounds.
The thermosetting resin composition according to any one of claims 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 linked 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, 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 is an integer between ~4.)
k is the average value of repeating units and ranges from 0.25 to 3.5. )
(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 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. 2. 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 22, 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 22 or 23, wherein the curing agent (B) contains an active ester curing agent (B1) and/or a phenolic curing agent (B2).
The thermosetting resin composition according to any one of claims 22 to 24, further comprising a curing catalyst (D).
The thermosetting resin composition according to any one of claims 1 to 25, which is used as a material for forming a microstrip antenna.
The thermosetting resin composition according to any one of claims 1 to 25, which is used as a material for forming a dielectric waveguide.
The thermosetting resin composition according to any one of claims 1 to 25, 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 25.
a dielectric substrate according to claim 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;
a 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 facing the radiation conductor plate;
A microstrip antenna comprising:
30. A microstrip antenna, wherein the high dielectric is composed of the dielectric substrate according to claim 29.