JP7303319B2 - Method for producing thermally conductive material, thermally conductive material, thermally conductive sheet, device with thermally conductive layer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing a thermally conductive material, a thermally conductive material, a thermally conductive sheet, and a device with a thermally conductive layer.

2. Description of the Related Art In recent years, power semiconductor devices used in various electrical equipment such as personal computers, general household appliances, and automobiles have rapidly been miniaturized. It is becoming difficult to control the heat generated from high-density power semiconductor devices due to miniaturization.
In order to deal with such problems, thermally conductive materials are used to promote heat dissipation from power semiconductor devices.
For example, Patent Document 1 describes an epoxy resin composition excellent in heat dissipation, which is described as "used for encapsulation of semiconductor elements, epoxy resin (A), phenolic resin-based curing agent (B), inorganic filler (C) and mold release material. agent (D), wherein the phenolic resin-based curing agent (B) contains a phenolic resin represented by the following general formula (1), and the inorganic filler (C) contains spherical alumina. , an epoxy resin composition characterized in that the release agent (D) contains a glycerin trifatty acid ester” has been disclosed.

JP 2008-297530 A

On the other hand, in recent years, there has been an increasing demand for forming thermally conductive materials using compositions that do not contain fillers or that contain fillers in a reduced amount.
Accordingly, an object of the present invention is to provide a method for producing a thermally conductive material that can provide a thermally conductive material having excellent thermal conductivity by using a composition for forming a thermally conductive material with a reduced filler content. and
Another object of the present invention is to provide a thermally conductive material, a thermally conductive sheet, and a device with a thermally conductive layer.

As a result of intensive studies aimed at solving the above problems, the inventors of the present invention have found that the above problems can be solved by the following configuration.

一般式（Ｐ０）中、Ｒ^Ｐ１～Ｒ^Ｐ５は、それぞれ独立に、水素原子又は置換基を表す。
ただし、Ｒ^Ｐ１及びＲ^Ｐ５の少なくとも一方は、置換基を表す。
〔２〕
上記本硬化工程において、０．５～１０ＭＰａの圧力下にて、上記予備硬化物に対して上記本硬化処理を施す、〔１〕に記載の熱伝導材料の製造方法。
〔３〕
上記一般式（Ｐ０）で表される化合物の水酸基含有量が、１２．０ｍｍｏｌ／ｇ以上である、〔１〕又は〔２〕に記載の熱伝導材料の製造方法。
〔４〕
上記一般式（Ｐ０）で表される化合物の分子量が、４００以下である、〔１〕～〔３〕のいずれかに記載の熱伝導材料の製造方法。
〔５〕
上記熱伝導材料形成用組成物が、更に、硬化促進剤を含む、〔１〕～〔４〕のいずれかに記載の熱伝導材料の製造方法。
〔６〕
一般式（Ｐ０）で表される化合物を含むフェノール化合物、及び、エポキシ化合物を含み、
上記フェノール化合物に含まれるフェノール性水酸基の数に対する、上記エポキシ化合物に含まれるエポキシ基の数との比が、４０／６０～６０／４０であり、
充填剤を含まないか、又は、上記充填剤を含む場合は、上記充填剤の含有量が、全固形分に対して、１０質量％以下である、熱伝導材料形成用組成物を、硬化してなる熱伝導材料であって、
赤外分光分析した際の、１６１０ｃｍ^－１におけるピーク強度に対する、９１０ｃｍ^－１におけるピーク強度の比が、０．０６以下である、熱伝導材料。

一般式（Ｐ０）中、Ｒ^Ｐ１～Ｒ^Ｐ５は、それぞれ独立に、水素原子又は置換基を表す。
ただし、Ｒ^Ｐ１及びＲ^Ｐ５の少なくとも一方は、置換基を表す。
〔７〕
上記一般式（Ｐ０）で表される化合物の水酸基含有量が、１２．０ｍｍｏｌ／ｇ以上である、〔６〕に記載の熱伝導材料。
〔８〕
上記一般式（Ｐ０）で表される化合物の分子量が、４００以下である、〔６〕又は〔７〕に記載の熱伝導材料。
〔９〕
更に、硬化促進剤を含む、〔６〕～〔８〕のいずれかに記載の熱伝導材料。
〔１０〕
〔６〕～〔９〕のいずれかに記載の熱伝導材料からなる、熱伝導シート。
〔１１〕
デバイスと、上記デバイス上に配置された〔１０〕に記載の熱伝導シートを含む熱伝導層とを有する、熱伝導層付きデバイス。[1]
A phenol compound containing a compound represented by the general formula (P0), and an epoxy compound,
The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenol compound is 40/60 to 60/40,
Using a composition for forming a thermally conductive material, which does not contain a filler, or when the filler is contained, the content of the filler is 10% by mass or less with respect to the total solid content, A method for manufacturing a thermally conductive material, comprising:
Under no pressure, the composition for forming a thermally conductive material is precured so that 1 to 90% of the phenol compound remains, based on a measurement method using high-performance liquid chromatography. to obtain a pre-cured product, a pre-curing step, and
A method for producing a thermally conductive material, comprising a final curing step of subjecting the precured product to a final curing treatment under a pressure of 0.1 MPa or more to obtain a thermally conductive material.

In general formula (P0), R ^P1 to R ^P5 each independently represent a hydrogen atom or a substituent.
However, at least one of R ^P1 and R ^P5 represents a substituent.
[2]
The method for producing a heat conductive material according to [1], wherein in the main curing step, the pre-cured material is subjected to the main curing treatment under a pressure of 0.5 to 10 MPa.
[3]
The method for producing a thermally conductive material according to [1] or [2], wherein the compound represented by the general formula (P0) has a hydroxyl group content of 12.0 mmol/g or more.
[4]
The method for producing a thermally conductive material according to any one of [1] to [3], wherein the compound represented by the general formula (P0) has a molecular weight of 400 or less.
[5]
The method for producing a thermally conductive material according to any one of [1] to [4], wherein the composition for forming a thermally conductive material further contains a curing accelerator.
[6]
A phenol compound containing a compound represented by the general formula (P0), and an epoxy compound,
The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenol compound is 40/60 to 60/40,
A composition for forming a thermally conductive material that does not contain a filler or, if it contains the filler, has a content of the filler of 10% by mass or less with respect to the total solid content is cured. A thermally conductive material comprising
A thermally conductive material having a ratio of peak intensity at 910 cm ⁻¹ to peak intensity at 1610 cm ⁻¹ of 0.06 or less when analyzed by infrared spectroscopy.

In general formula (P0), R ^P1 to R ^P5 each independently represent a hydrogen atom or a substituent.
However, at least one of R ^P1 and R ^P5 represents a substituent.
[7]
The thermally conductive material according to [6], wherein the compound represented by the general formula (P0) has a hydroxyl group content of 12.0 mmol/g or more.
[8]
The thermally conductive material according to [6] or [7], wherein the compound represented by the general formula (P0) has a molecular weight of 400 or less.
[9]
The thermally conductive material according to any one of [6] to [8], further comprising a curing accelerator.
[10]
A thermally conductive sheet made of the thermally conductive material according to any one of [6] to [9].
[11]
A device with a thermally conductive layer, comprising: a device; and a thermally conductive layer containing the thermally conductive sheet of [10] disposed on the device.

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the thermally-conductive material which can provide the thermally-conductive material excellent in thermal conductivity using the composition for thermally-conductive-material formation with which the content of the filler was reduced can be provided.
Moreover, according to the present invention, a thermally conductive material, a thermally conductive sheet, and a device with a thermally conductive layer can be obtained.

Hereinafter, the method for producing a thermally conductive material, the thermally conductive material, the thermally conductive sheet, and the device with a thermally conductive layer of the present invention will be described in detail.
The description of the constituent elements described below may be made based on representative embodiments of the present invention, but the present invention is not limited to such embodiments.
In this specification, a numerical range represented by "-" means a range including the numerical values before and after "-" as lower and upper limits.

In the present specification, for substituents and the like that are not specified as substituted or unsubstituted, if possible, further substituents (for example, the group of substituents described later) within the range that does not impair the intended effect Y). For example, the notation "alkyl group" means a substituted or unsubstituted alkyl group (an alkyl group that may have a substituent) within a range that does not impair the intended effect.
Moreover, in the present specification, the type of substituent, the position of the substituent, and the number of substituents in the case of "optionally having a substituent" are not particularly limited. The number of substituents may be, for example, 1 or 2 or more. Examples of substituents include monovalent nonmetallic atomic groups excluding hydrogen atoms, and groups selected from the following substituent group Y are preferable.
As used herein, the halogen atom includes, for example, a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom.

Substituent group Y:
Halogen atoms (-F, -Br, -Cl, -I, etc.), hydroxyl groups, amino groups, carboxylic acid groups and their conjugate base groups, carboxylic anhydride groups, cyanate ester groups, unsaturated polymerizable groups, epoxy groups, oxetanyl group, aziridinyl group, thiol group, isocyanate group, thioisocyanate group, aldehyde group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkyldithio group, aryldithio group, N-alkylamino group, N,N-dialkylamino group, N-arylamino group, N,N-diarylamino group, N-alkyl-N-arylamino group, acyloxy group, carbamoyloxy group, N-alkylcarbamoyloxy group, N-arylcarbamoyloxy group, N,N -dialkylcarbamoyloxy group, N,N-diarylcarbamoyloxy group, N-alkyl-N-arylcarbamoyloxy group, alkylsulfoxy group, arylsulfoxy group, acylthio group, acylamino group, N-alkylacylamino group, N -aryl acylamino group, ureido group, N'-alkylureido group, N',N'-dialkylureido group, N'-arylureido group, N',N'-diarylureido group, N'-alkyl-N' -arylureido group, N-alkylureido group, N-arylureido group, N'-alkyl-N-alkylureido group, N'-alkyl-N-arylureido group, N',N'-dialkyl-N-alkyl ureido group, N',N'-dialkyl-N-arylureido group, N'-aryl-N-alkylureido group, N'-aryl-N-arylureido group, N',N'-diaryl-N-alkyl ureido group, N',N'-diaryl-N-arylureido group, N'-alkyl-N'-aryl-N-alkylureido group, N'-alkyl-N'-aryl-N-arylureido group, alkoxy carbonylamino group, aryloxycarbonylamino group, N-alkyl-N-alkoxycarbonylamino group, N-alkyl-N-aryloxycarbonylamino group, N-aryl-N-alkoxycarbonylamino group, N-aryl-N- aryloxycarbonylamino group, formyl group, acyl group, alkoxycarbonyl group, aryloxycarbonyl group, carbamoyl group, N-alkylcarbamoyl group, N,N-dialkylcarbamoyl group, N-arylcarbamoyl group, N,N-diarylcarbamoyl groups, N-alkyl-N-arylcarbamoyl groups, alkylsulfinyl groups, arylsulfinyl groups, alkylsulfonyl groups, arylsulfonyl groups, sulfo groups (—SO ₃ H) and their conjugate base groups, alkoxysulfonyl groups, aryloxysulfonyl groups , sulfinamoyl group, N-alkylsulfinamoyl group, N,N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N,N-diarylsulfinamoyl group, N-alkyl-N-arylsulfinamoyl group, sulfamoyl group, N-alkylsulfamoyl group, N,N-dialkylsulfamoyl group, N-arylsulfamoyl group, N,N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group moyl group, N-acylsulfamoyl group and its conjugate base group, N-alkylsulfonylsulfamoyl group (-SO ₂ NHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonylsulfamoyl group (- SO ₂ NHSO ₂ (aryl)) and its conjugate base group, N-alkylsulfonylcarbamoyl group (—CONHSO ₂ (alkyl)) and its conjugate base group, N-arylsulfonylcarbamoyl group (—CONHSO ₂ (aryl)) and its Conjugate base group, alkoxysilyl group (-Si(Oalkyl) ₃ ), aryloxysilyl group (-Si(Oaryl) ₃ ), hydroxysilyl group (-Si(OH) ₃ ) and its conjugate base group, phosphono group (- PO ₃ H ₂ ) and its conjugate base group, dialkylphosphono group (-PO ₃ (alkyl) ₂ ), diarylphosphono group (-PO ₃ (aryl) ₂ ), alkylarylphosphono group (-PO ₃ (alkyl )(aryl)), a monoalkylphosphono group (—PO ₃ H(alkyl)) and its conjugate base group, a monoarylphosphono group (—PO ₃ H(aryl)) and its conjugate base group, a phosphonooxy group (— OPO ₃ H ₂ ) and its conjugate base group, dialkylphosphonoxy group (-OPO ₃ (alkyl) ₂ ), diarylphosphonoxy group (-OPO ₃ (aryl) ₂ ), alkylarylphosphonoxy group (-OPO ₃ (alkyl)(aryl)), a monoalkylphosphonoxy group (—OPO ₃ H(alkyl)) and its conjugate base group, a monoarylphosphonoxy group (—OPO ₃ H(aryl)) and its conjugate base group , cyano, nitro, aryl, alkenyl, alkynyl, and alkyl groups. In addition, each group described above may further have a substituent (for example, one or more groups among the groups described above), if possible. For example, an optionally substituted aryl group is also included as a group that can be selected from the substituent group Y.
When the group selected from Substituent Group Y has carbon atoms, the number of carbon atoms in the above group is, for example, 1-20.
The number of atoms other than hydrogen atoms possessed by the group selected from Substituent Group Y is, for example, 1-30.
In addition, these substituents may or may not form a ring by bonding with each other or with a substituting group, if possible. For example, an alkyl group (or an alkyl group moiety in a group containing an alkyl group as a partial structure, such as an alkoxy group) may be a cyclic alkyl group (cycloalkyl group) and has one or more cyclic structures as a partial structure. It may be an alkyl group.

[Method for producing thermally conductive material]
The method for producing a heat conductive material of the present invention includes a phenol compound including a compound represented by the general formula (P0) described later, and an epoxy compound,
The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenol compound is 40/60 to 60/40,
Using a composition for forming a thermally conductive material, which does not contain a filler, or when the filler is contained, the content of the filler is 10% by mass or less with respect to the total solid content, A method for manufacturing a thermally conductive material, comprising:
Under no pressure, the composition for forming a thermally conductive material is precured so that 1 to 90% of the phenol compound remains, based on a measurement method using high-performance liquid chromatography. to obtain a pre-cured product, a pre-curing step, and
A method for producing a thermally conductive material, comprising a final curing step of subjecting the precured product to a final curing treatment under a pressure of 0.1 MPa or more to obtain a thermally conductive material.

Although the mechanism by which the composition of the present invention has the above configuration to solve the problems of the present invention is not necessarily clear, the present inventors speculate as follows.
First, in the method for producing a thermally conductive material of the present invention (hereinafter also simply referred to as the “production method of the present invention”), a phenol compound containing a compound represented by the general formula (P0) and a heat conducting material containing an epoxy compound A material-forming composition (hereinafter also simply referred to as "composition") is used. The compound represented by the general formula (P0) is a compound having a phenolic hydroxyl group (ortho-substituted hydroxyl group) present adjacent to a substituent on the benzene ring group. The present inventors have found that if a crosslinked structure is constructed while using such ortho-substituted hydroxyl groups as crosslinking points, a dense thermal conduction path can be constructed, and the thermal conductivity of the resulting thermally conductive material can be improved. I thought it would connect. On the other hand, the present inventors have found that ortho-substituted hydroxyl groups have low reactivity due to the effects of steric hindrance and the like, and that simple heat curing treatment tends to result in a low reaction rate.
Therefore, in the production method of the present invention, the curing treatment of the composition is divided into a preliminary curing step and a main curing step, thereby promoting the reaction of the ortho-substituted hydroxyl groups and allowing the ortho-substituted hydroxyl groups to effectively act as cross-linking points. adjusted for ease of use.
Specifically, first, the phenolic hydroxyl groups are partially reacted by pre-curing treatment performed without pressure, and the ortho-substituted hydroxyl groups are efficiently converted in the next step under pressure (main curing treatment). A pre-cured product adjusted to allow reaction is obtained (pre-curing step).
Next, the remaining ortho-substituted hydroxyl groups are effectively reacted by treatment under pressure (main curing treatment) to obtain a thermally conductive material (main curing step).
In general, the application of pressure when curing a composition for forming a thermally conductive material prevents the formation of voids (spaces) derived from the filler in the cured product (thermally conductive material) in a system in which the composition contains a filler. It is often done to avoid Therefore, when curing a composition containing no filler (or a system with a low filler content), there is no need to worry about voids, and pressurization is considered unnecessary. In many cases, it was not implemented. On the other hand, the present inventors intentionally performed the main curing treatment under pressure after making the composition into a pre-cured product, so that the phenolic hydroxyl groups at positions adjacent to the substituents can be effectively reacted, It is speculated that the thermal conductivity of the thermally conductive material could be improved.

Hereinafter, first, the components contained in the composition used in the production method of the present invention will be described, and then each step in the production method of the present invention will be described.

[Composition (composition for forming thermal conductive material)]
<Phenol compound>
The compositions used in the present invention contain phenolic compounds.
A phenolic compound is a compound having at least one (preferably two or more) phenolic hydroxyl groups.
The phenol compound includes a compound represented by general formula (P0) (a phenol compound represented by general formula (P0)).
General formula (P0) is shown below.

In general formula (P0), R ^P1 to R ^P5 each independently represent a hydrogen atom or a substituent.
However, at least one of R ^P1 and R ^P5 represents a substituent.
At least one substituent exists adjacently on the benzene ring group to the hydroxyl group specified in the general formula (P0). That is, the hydroxyl group is present in ortho-coordination with respect to the substituent.
Such a hydroxyl group in which at least one of the two adjacent hydroxyl groups on the benzene ring group is a group other than a hydrogen atom is also referred to as an ortho-substituted hydroxyl group. When two hydroxyl groups are arranged adjacent to each other on the benzene ring group, both of the two hydroxyl groups are ortho-substituted hydroxyl groups.
The compound represented by the general formula (P0) is preferably a compound having two or more phenolic hydroxyl groups (at least one of which is an ortho-substituted hydroxyl group), and is a compound having two or more ortho-substituted hydroxyl groups. is more preferred.
Further, the compound represented by the general formula (P0) has a plurality (preferably 2 to 6) of benzene ring groups, of which two or more benzene ring groups (preferably the majority of the benzene ring groups, more preferably and all benzene ring groups) each have an ortho-substituted hydroxyl group.

The compound represented by general formula (P0) is preferably a compound represented by general formula (P1).
General formula (P1) is shown below.

In general formula (P1), at least one (preferably 1 to 9) hydroxyl groups are present adjacent to groups other than hydrogen atoms on the benzene ring group.

In general formula (P1), m1 represents an integer of 0 or more.
m1 is preferably 0 to 10, more preferably 0 to 3, still more preferably 0 or 1, and particularly preferably 1.

In general formula (P1), Ar ¹ represents an aromatic ring group. Ar ¹ is preferably a benzene ring group or a naphthalene ring group, more preferably a benzene ring group.
In general formula (P1), na represents an integer of 0 or more.
na is preferably 0 to 8, more preferably 1 to 4.
When Ar ¹ is a benzene ring group, na is an integer of 0-4, and when Ar ¹ is a naphthalene ring group, na is an integer of 0-7.
In general formula (P1), R ¹ represents a hydroxyl group, a halogen atom, a carboxylic acid group, a boronic acid group, an aldehyde group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group.
The above alkyl groups may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. The alkyl group may or may not have a substituent.
The alkyl group portion of the alkoxy group and the alkyl group portion of the alkoxycarbonyl group are the same as the alkyl group.
R ¹ is preferably a hydroxyl group or a halogen atom, more preferably a hydroxyl group or a chlorine atom, and still more preferably a hydroxyl group.
When there are multiple R ¹ 's, the multiple R ¹ 's may be the same or different.
It is also preferable that 1 to 2 R ¹ representing a hydroxyl group are present in the general formula (P1).

The general formula (P1) preferably satisfies condition A below.
Condition A: Ar ¹ is a benzene ring group, and on the benzene ring group, at least one of R ¹ , which may have a plurality of hydroxyl groups specified in general formula (P1) bonded to Ar ¹ Ar ¹ is a benzene ring group, and on the benzene ring group, the hydroxyl group shown ^{in general formula (P1) bonded to Ar 1 is} one or both of binding position and being adjacent to each other.

In general formula (P1), Ar ² represents an aromatic ring group. Ar ² is preferably a benzene ring group or a naphthalene ring group, more preferably a benzene ring group.
In general formula (P1), nb represents an integer of 0 or more.
nb is preferably 0 to 8, more preferably 1 to 4.
When Ar ² is a benzene ring group, nb is an integer of 0-4, and when Ar ² is a naphthalene ring group, nb is an integer of 0-7.
In general formula (P1), ^R6 represents a hydroxyl group, a halogen atom, a carboxylic acid group, a boronic acid group, an aldehyde group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group.
The above alkyl groups may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. The alkyl group may or may not have a substituent.
The alkyl group portion of the alkoxy group and the alkyl group portion of the alkoxycarbonyl group are the same as the alkyl group.
R ⁶ is preferably a hydroxyl group or a halogen atom, more preferably a hydroxyl group or a chlorine atom, and still more preferably a hydroxyl group.
When multiple R ⁶ are present, the multiple R ⁶ may be the same or different.
It is also preferred that 1 to 2 R ⁶ representing a hydroxyl group are present in general formula (P1).

It is also preferable that general formula (P1) satisfies condition B below.
Condition B: Ar ² is a benzene ring group, and on the benzene ring group, at least one of R ⁶ , which may have ^a plurality of hydroxyl groups specified in general formula (P1) bonded to Ar 2 Ar ² is a benzene ring group, and on the benzene ring group, the hydroxyl group shown in general formula (P1) bonded to Ar ² is L ^X2 (m1 is 0, it exists adjacent to the binding position with L ^X1 ), or both.

In general formula (P1), nc represents an integer of 0 or 1; nc is preferably 1.
In general formula (P1), nd represents an integer of 0-4. nd is preferably 1.
Note that nc+nd is in the range of 0-4.
In general formula (P1), ^Qa represents a hydroxyl group, an alkyl group, a phenyl group, a halogen atom, a carboxylic acid group, a boronic acid group, an aldehyde group, an alkoxy group, or an alkoxycarbonyl group.
However, when nc is 0, ^Qa represents a group other than a hydroxyl group (an alkyl group, a phenyl group, a halogen atom, a carboxylic acid group, a boronic acid group, an aldehyde group, an alkoxy group, or an alkoxycarbonyl group).
The above alkyl groups may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. The alkyl group may or may not have a substituent.
The alkyl group portion in the alkoxy group and the alkyl group portion in the alkoxycarbonyl group are the same as the alkyl group.
The phenyl group may or may not have a substituent.
When nd is 2 or more, multiple Q ^a in (Q ^a ) _nd may be the same or different.
When nc is 1 or more and nd is 1 or more, at least one pair of OH (hydroxyl group) and Q ^a may be present at the para position to each other on the benzene ring group to which (Q ^a ) _nd is bonded. preferable.
In addition, when m1 is 2 or more, a plurality of structural moieties enclosed in brackets [ ] may be the same or different. That is, when m1 is 2 or more, multiple (OH) _nc , (Q ^a ) _nd and/or L ^X2 may be the same or different.

It is also preferable that general formula (P1) satisfies condition C below.
Condition C: m1 is an integer of 1 or more, and at least one (preferably a majority, more preferably all) of m1 structural sites enclosed in brackets [ ], nc in (OH) _nc is 1 and Q ^a , L ^X2 and/or L ^X1 are arranged on one or both sides (ortho positions) of the (OH) _nc on the benzene ring group to which the (OH) _nc is bonded. there is

In general formula (P1), L ^x1 represents a single bond, —C(R ² )(R ³ )—, or —CO—, and —C(R ² )(R ³ )— or —CO— is preferable.
L ^x2 represents a single bond, -C(R ⁴ )(R ⁵ )- or -CO-, preferably -C(R ⁴ )(R ⁵ )- or -CO-.
R ² to R ⁵ each independently represent a hydrogen atom or a substituent.
The above substituents are each independently preferably a hydroxyl group, a phenyl group, a halogen atom, a carboxylic acid group, a boronic acid group, an aldehyde group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group, and a hydroxyl group, a halogen atom, or a carboxylic acid group. , a boronic acid group, an aldehyde group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group are more preferred.
The above alkyl groups may be linear or branched. The number of carbon atoms in the alkyl group is preferably 1-10. The alkyl group may or may not have a substituent.
The alkyl group portion in the alkoxy group and the alkyl group portion in the alkoxycarbonyl group are the same as the alkyl group.
The phenyl group may or may not have a substituent, and when it has a substituent, it preferably has 1 to 3 hydroxyl groups.
R ² to R ⁵ are each independently preferably a hydrogen atom or a hydroxyl group, more preferably a hydrogen atom.
L ^x1 and L ^x2 are each independently preferably -CH ₂ -, -CH(OH)- or -CO-, more preferably -CH ₂ -.
In general formula (P1), when a plurality of R ⁴ are present, the plurality of R ⁴ may be the same or different. When there are multiple R ⁵ 's, the multiple R ⁵ 's may be the same or different.

The compound represented by the general formula (P1) preferably satisfies at least one of the above conditions A, B, and C, more preferably satisfies at least two, and satisfies all of them. is more preferred.

Other examples of compounds represented by the general formula (P0) include polyhydroxybenzenes having ortho-substituted hydroxyl groups such as catechol, 1,2,4-benzenetriol, and 1,2,3-benzenetriol. mentioned.

The molecular weight of the compound represented by general formula (P0) (preferably the compound represented by general formula (P1)) is preferably 600 or less, more preferably 400 or less. The lower limit of the molecular weight is preferably 110 or more, more preferably 200 or more, and even more preferably 300 or more.
The lower limit of the phenolic hydroxyl group content of the compound represented by the general formula (P0) (preferably the compound represented by the general formula (P1)) is preferably 8.0 mmol/g or more, and 12.0 mmol/g or more. is more preferred. The upper limit is preferably 25.0 mmol/g or less.
In addition, the said phenolic hydroxyl group content intends the number of the phenolic hydroxyl groups which 1g of phenolic compounds have.

The phenolic compound may include other phenolic compounds other than the compound represented by the general formula (P0).
The content of the compound represented by the general formula (P0) (preferably the compound represented by the general formula (P1)) is preferably 20 to 100% by mass, preferably 55 to 100% by mass, based on the total mass of the phenol compound. % is more preferred, and 85 to 100% by mass is more preferred.
The compound represented by general formula (P0) (preferably the compound represented by general formula (P1)) may be used singly or in combination of two or more.

Examples of the other phenolic compounds include biphenylaralkyl-type phenolic resins, phenolic novolac resins, cresol novolak resins, aromatic hydrocarbon-formaldehyde resin-modified phenolic resins, and dicyclopentadiene, other than the compounds represented by the general formula (P0). Phenol addition type resins, phenol aralkyl resins, polyhydric phenol novolac resins synthesized from polyhydric hydroxy compounds and formaldehyde, naphthol aralkyl resins, trimethylolmethane resins, tetraphenylolethane resins, naphthol novolak resins, naphthol phenol cocondensed novolacs Resins, naphthol-cresol cocondensed novolak resins, biphenyl-modified phenol resins, biphenyl-modified naphthol resins, aminotriazine-modified phenol resins, alkoxy group-containing aromatic ring-modified novolak resins, and the like can also be used.

The lower limit of the hydroxyl group content of the phenol compound as a whole is preferably 8.0 mmol/g or more, more preferably 12.0 mmol/g or more. The upper limit is preferably 25.0 mmol/g or less.
Moreover, the phenolic compound may or may not have an active hydrogen-containing group (such as a carboxylic acid group) capable of undergoing a polymerization reaction with the epoxy compound, in addition to the phenolic hydroxyl group. The lower limit of the active hydrogen content (total content of hydrogen atoms in phenolic hydroxyl groups, carboxylic acid groups, etc.) in the phenol compound as a whole is preferably 8.0 mmol/g or more, more preferably 12.0 mmol/g or more. . The upper limit is preferably 25.0 mmol/g or less.

A phenol compound may be used individually by 1 type, and may use 2 or more types.
In addition to the phenolic compound, the composition used in the present invention may also contain a compound having a group capable of reacting with the epoxy compound described below (also referred to as "another active hydrogen-containing compound").
However, in the composition used in the present invention, the mass ratio of the content of the other active hydrogen-containing compound to the content of the phenol compound is preferably 0 to 1, more preferably 0 to 0.1, and 0 to 0.05 is more preferred.

<Epoxy compound>
The compositions used in the present invention contain epoxy compounds.
An epoxy compound is a compound having at least one epoxy group (oxiranyl group) in one molecule.
The epoxy group is a group obtained by removing one or more hydrogen atoms (preferably one hydrogen atom) from an oxirane ring. If possible, the epoxy group may further have a substituent (linear or branched alkyl group having 1 to 5 carbon atoms, etc.).

The number of epoxy groups in the epoxy compound is preferably 2 or more, more preferably 2 to 40, still more preferably 2 to 10, and particularly preferably 2, in one molecule.
The epoxy compound preferably has a molecular weight of 150 to 10,000, more preferably 150 to 2,000.

The epoxy group content of the epoxy compound is preferably 2.0 to 20.0 mmol/g, more preferably 5.0 to 15.0 mmol/g.
In addition, the said epoxy group content intends the number of epoxy groups which 1g of epoxy compounds have.
The epoxy compound also preferably has an aromatic ring group (preferably an aromatic hydrocarbon ring group).

The epoxy compound may or may not exhibit liquid crystallinity.
That is, the epoxy compound may be a liquid crystal compound. In other words, it may be a liquid crystal compound having an epoxy group.
Examples of the epoxy compound (which may be a liquid crystalline epoxy compound) include a compound at least partially containing a rod-like structure (rod-like compound) and a compound at least partially including a discotic structure (disc-like compound). is mentioned.
The rod-like compound and discotic compound are described in detail below.

(Rod-shaped compound)
Epoxy compounds that are rod-like compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenyl Examples include pyrimidines, phenyldioxanes, tolanes, and alkenylcyclohexylbenzonitriles. Not only low-molecular-weight compounds as described above, but also high-molecular-weight compounds can be used. The polymer compound is a polymer compound in which a rod-shaped compound having a low-molecular-weight reactive group is polymerized.
Preferred rod-shaped compounds include rod-shaped compounds represented by the following general formula (XXI).
General formula (XXI): Q ¹ -L ¹¹¹ -A ¹¹¹ -L ¹¹³ -ML ¹¹⁴ -A ¹¹² -L ¹¹² -Q ²

In general formula (XXI), Q ¹ and Q ² are each independently an epoxy group, and L ¹¹¹ , L ¹¹² , L ¹¹³ and L ¹¹⁴ each independently represent a single bond or a divalent linking group. . A ¹¹¹ and A ¹¹² each independently represent a divalent linking group (spacer group) having 1 to 20 carbon atoms. M represents a mesogenic group.
The epoxy groups of Q ¹ and Q ² may or may not have a substituent.

In general formula (XXI), L ¹¹¹ , L ¹¹² , L ¹¹³ and L ¹¹⁴ each independently represent a single bond or a divalent linking group.
The divalent linking groups represented by L ¹¹¹ , L ¹¹² , L ¹¹³ and L ¹¹⁴ are each independently -O-, -S-, -CO-, -NR ¹¹² - and -CO-O -, -O-CO-O-, -CO-NR ¹¹² -, -NR ¹¹² -CO-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -, -O-CO-NR It is preferably a divalent linking group selected from the group consisting of ^112- , -NR ¹¹² -CO-O- and -NR ¹¹² -CO-NR ¹¹² -. R ¹¹² above is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom.
Among them, L ¹¹³ and L ¹¹⁴ are each independently preferably -O-.
L ¹¹¹ and L ¹¹² are each independently preferably a single bond.

In general formula (XXI), A ¹¹¹ and A ¹¹² each independently represent a divalent linking group having 1 to 20 carbon atoms.
The divalent linking group may contain non-adjacent heteroatoms such as oxygen and sulfur atoms. Among them, an alkylene group, an alkenylene group, or an alkynylene group having 1 to 12 carbon atoms is preferable. The above alkylene group, alkenylene group, or alkynylene group may or may not have an ester group.
The divalent linking group is preferably linear, and the divalent linking group may or may not have a substituent. Examples of substituents include halogen atoms (fluorine, chlorine and bromine atoms), cyano groups, methyl groups and ethyl groups.
Among them, A ¹¹¹ and A ¹¹² are each independently preferably an alkylene group having 1 to 12 carbon atoms, more preferably a methylene group.

In general formula (XXI), M represents a mesogenic group, and examples of the mesogenic group include known mesogenic groups. Among them, a group represented by the following general formula (XXII) is preferable.
general formula (XXII): -(W ¹ -L ¹¹⁵ ) _n -W ² -

In formula (XXII), W ¹ and W ² each independently represent a divalent cyclic alkylene group, a divalent cyclic alkenylene group, an arylene group, or a divalent heterocyclic group. L ¹¹⁵ represents a single bond or a divalent linking group. n represents an integer of 1-4.

Examples of W ¹ and W ² include 1,4-cyclohexenediyl, 1,4-cyclohexanediyl, 1,4-phenylene, pyrimidine-2,5-diyl, pyridine-2,5-diyl, 1,3, 4-thiadiazole-2,5-diyl, 1,3,4-oxadiazole-2,5-diyl, naphthalene-2,6-diyl, naphthalene-1,5-diyl, thiophene-2,5-diyl, and pyridazine-3,6-diyl. In the case of 1,4-cyclohexanediyl, it may be either trans- or cis-structural isomers, or may be a mixture of any ratio. Among them, the trans form is preferred.
W ¹ and W ² may each have a substituent. Examples of substituents include groups exemplified in the above-described substituent group Y, more specifically, halogen atoms (fluorine atom, chlorine atom, bromine atom, and iodine atom), cyano group, carbon 1 to 10 alkyl groups (e.g., methyl group, ethyl group, and propyl group), alkoxy groups with 1 to 10 carbon atoms (e.g., methoxy group, ethoxy group, etc.), 1 to 10 carbon atoms Acyl group (e.g., formyl group, acetyl group, etc.), alkoxycarbonyl group having 1 to 10 carbon atoms (e.g., methoxycarbonyl group, ethoxycarbonyl group, etc.), acyloxy group having 1 to 10 carbon atoms (e.g., acetyloxy group, propionyloxy group, etc.), nitro group, trifluoromethyl group, difluoromethyl group and the like.
When there are multiple ^W1 's, the multiple ^W1 's may be the same or different.

In general formula (XXII), ^L115 represents a single bond or a divalent linking group. Specific examples of the divalent linking group represented by L ¹¹⁵ include the divalent linking groups represented by L ¹¹¹ to L ¹¹⁴ described above, for example, -CO-O-, -O-CO- , —CH ₂ —O—, and —O—CH ₂ —.
When multiple L ¹¹⁵ are present, the multiple L ¹¹⁵ may be the same or different.

Preferred basic skeletons of the mesogenic group represented by the above general formula (XXII) are exemplified below. In the mesogenic group, these skeletons may be substituted with a substituent.

Among the skeletons described above, a biphenyl skeleton is preferable because the obtained thermally conductive material has more excellent thermal conductivity.
Incidentally, the compound represented by the general formula (XXI) can be synthesized by referring to the method described in JP-A-11-513019 (WO97/00600).
The rod-shaped compound may be a monomer having a mesogenic group as described in JP-A-11-323162 and JP-A-4118691.

Among them, the rod-shaped compound is preferably a compound represented by general formula (E1).

In general formula (E1), each L ^E1 independently represents a single bond or a divalent linking group.
Among them, L ^E1 is preferably a divalent linking group.
Divalent linking groups are -O-, -S-, -CO-, -NH-, -CH=CH-, -C≡C-, -CH=N-, -N=CH-, -N= N-, an optionally substituted alkylene group, or a group consisting of a combination of two or more of these is preferred, and -O-alkylene group- or -alkylene group -O- is more preferred.
The alkylene group may be linear, branched, or cyclic, but a linear alkylene group having 1 to 2 carbon atoms is preferred.
Multiple L ^E1 may be the same or different.

In general formula (E1), L ^E2 is each independently a single bond, -CH=CH-, -CO-O-, -O-CO-, -C(-CH ₃ )=CH-, -CH= C(-CH ₃ )-, -CH=N-, -N=CH-, -N=N-, -C≡C-, -N=N ⁺ (-O ^- )-, -N ⁺ (-O ^- )=N-, -CH=N ⁺ (-O ^- )-, -N ⁺ (-O ^- )=CH-, -CH=CH-CO-, -CO-CH=CH-, -CH=C represents (-CN)- or -C(-CN)=CH-.
Among them, each L ^E2 is preferably independently a single bond, —CO—O—, or —O—CO—.
When a plurality of ^LE2 are present, the plurality of ^LE2 may be the same or different.

In general formula (E1), L ^E3 is each independently a single bond, or an optionally substituted 5- or 6-membered aromatic ring group or a 5- or 6-membered ring or a polycyclic group consisting of these rings.
Examples of the aromatic ring group and non-aromatic ring group represented by L ^E3 include optionally substituted 1,4-cyclohexanediyl group, 1,4-cyclohexenediyl group, 1,4 -phenylene group, pyrimidine-2,5-diyl group, pyridine-2,5-diyl group, 1,3,4-thiadiazole-2,5-diyl group, 1,3,4-oxadiazole-2,5 -diyl group, naphthalene-2,6-diyl group, naphthalene-1,5-diyl group, thiophene-2,5-diyl group, and pyridazine-3,6-diyl group. In the case of a 1,4-cyclohexanediyl group, it may be either a trans or cis structural isomer, or a mixture of any ratio. Among them, the trans form is preferred.
Among them, L ^E3 is preferably a single bond, a 1,4-phenylene group, or a 1,4-cyclohexenediyl group.
The substituents possessed by the group represented by L ^E3 are each independently preferably an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, or an acetyl group, more preferably an alkyl group (preferably having 1 carbon atom). preferable.
In addition, when a plurality of substituents are present, the substituents may be the same or different.
When there are a plurality of ^LE3s , the plurality of ^LE3s may be the same or different.

In general formula (E1), pe represents an integer of 0 or more.
When pe is an integer of 2 or more, a plurality of (-L ^E3 -L ^E2 -) may be the same or different.
Among them, pe is preferably 0 to 2, more preferably 0 or 1, and still more preferably 0.

In general formula (E1), L ^E4 each independently represents a substituent.
The substituents are each independently preferably an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, or an acetyl group, and more preferably an alkyl group (preferably having 1 carbon atom).
A plurality of ^LE4 may be the same or different. Further, when le, which will be described below, is an integer of 2 or more, multiple ^LE4s present in the same (L ^E4 ) _le may be the same or different.

In general formula (E1), each le independently represents an integer of 0 to 4.
Among them, each le is preferably independently 0 to 2.
A plurality of le's may be the same or different.

The rod-shaped compound preferably has a biphenyl skeleton in that the thermal conductivity of the resulting thermally conductive material is superior.
In other words, the epoxy compound preferably has a biphenyl skeleton, and in this case the epoxy compound is more preferably a rod-shaped compound.

(disc-shaped compound)
Epoxy compounds that are discotic compounds have at least partially a discotic structure.
The discotic structure has at least an alicyclic or aromatic ring. In particular, when the discotic structure has an aromatic ring, the discotic compound can form a columnar structure through the formation of a stacking structure due to intermolecular π-π interactions.
As a disk-shaped structure, specifically, Angew. Chem. Int. Ed. 2012, 51, 7990-7993 or the triphenylene structure described in JP-A-7-306317, and the trisubstituted benzene structure described in JP-A-2007-2220 and JP-A-2010-244038.

If a discotic compound is used as the epoxy compound, a thermally conductive material exhibiting high thermal conductivity can be obtained. The reason for this is that while the rod-shaped compound can only conduct heat linearly (one-dimensionally), the discotic compound can conduct heat two-dimensionally in the normal direction. It is thought that the thermal conductivity is improved.

The discotic compound preferably has three or more epoxy groups. A cured product of a composition containing a discotic compound having three or more epoxy groups tends to have a high glass transition temperature and high heat resistance.
The number of epoxy groups possessed by the discotic compound is preferably 8 or less, more preferably 6 or less.

Specific examples of discotic compounds include C.I. Destrade et al. , Mol. Crysr. Liq. Cryst. , vol. 71, page 111 (1981); edited by The Chemical Society of Japan, Quarterly Kagaku Sosetsu, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); Kohne et al. , Angew. Chem. Soc. Chem. Comm. , page 1794 (1985); Zhang et al. , J. Am. Chem. Soc. , vol. 116, page 2655 (1994), and Japanese Patent No. 4592225, and compounds having at least one terminal (preferably three or more) of epoxy groups.
As the discotic compound, Angew. Chem. Int. Ed. 2012, 51, 7990-7993, and the triphenylene structure described in JP-A-7-306317, and JP-A-2007-2220, and the terminal in the trisubstituted benzene structure described in JP-A-2010-244038 Examples include compounds having at least one (preferably three or more) epoxy groups.

As the discotic compound, a compound represented by any one of formulas (D1) to (D16) shown below is preferable from the viewpoint of better thermal conductivity of the thermally conductive material.
Formulas (D1) to (D15) will be described first, and then formula (D16) will be described.
In the following formulas, "-LQ" represents "-LQ" and "QL-" represents "QL-".

In formulas (D1) to (D15), L represents a divalent linking group.
From the viewpoint of better thermal conductivity of the thermally conductive material, each L is independently an alkylene group, an alkenylene group, an arylene group, -CO-, -NH-, -O-, -S-, and combinations thereof. It is preferably a group selected from the group consisting of two or more groups selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, -CO-, -NH-, -O-, and -S- More preferred are combined groups.
The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The arylene group preferably has 10 or less carbon atoms.
Alkylene groups, alkenylene groups and arylene groups may have substituents (preferably alkyl groups, halogen atoms, cyano, alkoxy groups, acyloxy groups, etc.).

Examples of L are shown below. In the following examples, the bond on the left side is bonded to the central structure of the compound represented by any of formulas (D1) to (D15) (hereinafter also simply referred to as the "central ring"), and the bond on the right side is Q bind to
AL means an alkylene or alkenylene group, and AR means an arylene group.

L101: -AL-CO-O-AL-
L102: -AL-CO-O-AL-O-
L103: -AL-CO-O-AL-O-AL-
L104: -AL-CO-O-AL-O-CO-
L105: -CO-AR-O-AL-
L106: -CO-AR-O-AL-O-
L107: -CO-AR-O-AL-O-CO-
L108: -CO-NH-AL-
L109: -NH-AL-O-
L110: -NH-AL-O-CO-
L111: -O-AL-
L112: -O-AL-O-
L113: -O-AL-O-CO-

L114: -O-AL-O-CO-NH-AL-
L115: -O-AL-S-AL-
L116: -O-CO-AL-AR-O-AL-O-CO-
L117: -O-CO-AR-O-AL-CO-
L118: -O-CO-AR-O-AL-O-CO-
L119: -O-CO-AR-O-AL-O-AL-O-CO-
L120: -O-CO-AR-O-AL-O-AL-O-AL-O-CO-
L121:-S-AL-
L122: -S-AL-O-
L123: -S-AL-O-CO-
L124: -S-AL-S-AL-
L125: -S-AR-AL-
L126: -O-CO-AL-
L127: -O-CO-AL-O-
L128: -O-CO-AR-O-AL-
L129: -O-CO-
L130: -O-CO-AR-O-AL-O-CO-AL-S-AR-
L131: -O-CO-AL-S-AR-
L132: -O-CO-AR-O-AL-O-CO-AL-S-AL-
L133: -O-CO-AL-S-AR-
L134: -O-AL-S-AR-
L135: -AL-CO-O-AL-O-CO-AL-S-AR-
L136: -AL-CO-O-AL-O-CO-AL-S-AL-
L137: -O-AL-O-AR-
L138: -O-AL-O-CO-AR-
L139: -O-AL-NH-AR-
L140: -O-CO-AL-O-AR-
L141: -O-CO-AR-O-AL-O-AR-
L142: -AL-CO-O-AR-
L143: -AL-CO-O-AL-O-AR-

In formulas (D1) to (D15), each Q independently represents a hydrogen atom or a substituent.
Examples of the substituent include groups exemplified in the substituent group Y described above. More specifically, the substituents include the above reactive functional groups, halogen atoms, isocyanate groups, cyano groups, unsaturated polymerizable groups, epoxy groups, oxetanyl groups, aziridinyl groups, thioisocyanate groups, aldehyde groups, and A sulfo group can be mentioned.
However, when Q is a group other than an epoxy group, Q is preferably stable with respect to the epoxy group.
In formulas (D1) to (D15), one or more (preferably two or more) Qs represent an epoxy group. Above all, it is preferable that all Qs represent an epoxy group from the viewpoint of better thermal conductivity of the thermally conductive material.
From the viewpoint of epoxy group stability, the compounds represented by formulas (D1) to (D15) preferably do not have —NH—.

Among the compounds represented by the formulas (D1) to (D15), the compound represented by the formula (D4) is preferable from the viewpoint that the thermal conductivity of the heat conductive material is more excellent. In other words, the central ring of the discotic compound is preferably a triphenylene ring.
As the compound represented by the formula (D4), the compound represented by the formula (XI) is preferable from the viewpoint that the thermal conductivity of the heat conductive material is more excellent.

In formula (XI), R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are each independently *-X ¹¹ -L ¹¹ -P ¹¹ or *-X ¹² -L ¹² -Y represents ¹² .
In addition, * represents the bonding position with the triphenylene ring.
Of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ , two or more are *-X ¹¹ -L ¹¹ -P ¹¹ and three or more are *-X ¹¹ -L ¹¹ -P ¹¹ is preferred.
Among them, one or more of R ¹¹ and R ¹² , one or more of R ¹³ and R ¹⁴ , and one of R ¹⁵ and R ¹⁶ , from the viewpoint of better thermal conductivity of the heat conductive material It is preferred that at least one is *-X ¹¹ -L ¹¹ -P ¹¹ .
More preferably, R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are all *-X ¹¹ -L ¹¹ -P ¹¹ . Additionally, it is more preferred that R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ and R ¹⁶ are all the same.

X ¹¹ is each independently a single bond, -O-, -CO-, -NH-, -O-CO-, -O-CO-O-, -O-CO-NH-, -O-CO- S-, -CO-O-, -CO-NH-, -CO-S-, -NH-CO-, -NH-CO-O-, -NH-CO-NH-, -NH-CO-S- , -S-, -S-CO-, -S-CO-O-, -S-CO-NH-, or -S-CO-S-.
Among them, X ¹¹ each independently represents -O-, -O-CO-, -O-CO-O-, -O-CO-NH-, -CO-O-, -CO-NH-, -NH -CO- or -NH-CO-O- is preferred, and -O-, -O-CO-, -CO-O-, -O-CO-NH- or -CO-NH- is more preferred , -O-CO- or -CO-O- is more preferred.

Each L ¹¹ independently represents a single bond or a divalent linking group.
Examples of divalent linking groups include -O-, -O-CO-, -CO-O-, -S-, -NH-, alkylene groups (the number of carbon atoms is preferably 1 to 10, 1 to 8 is more preferable, and 1 to 7 are more preferable.), an arylene group (the number of carbon atoms is preferably 6 to 20, more preferably 6 to 14, more preferably 6 to 10.), or a group consisting of a combination thereof are mentioned.
Examples of the alkylene group include methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, and heptylene group.
The arylene group includes a 1,4-phenylene group, a 1,3-phenylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, and an anthracenylene group, with a 1,4-phenylene group being preferred. .

Each of the alkylene group and the arylene group may have a substituent. The number of substituents is preferably 1 to 3, more preferably 1. The substitution position of the substituent is not particularly limited. The substituent is preferably a halogen atom or an alkyl group having 1 to 3 carbon atoms, more preferably a methyl group.
It is also preferred that the alkylene group and the arylene group are unsubstituted. Among them, the alkylene group is preferably unsubstituted.

Examples of -X ¹¹ -L ¹¹ - include L101 to L143, which are examples of L described above.

^P11 represents an epoxy group. The epoxy group may or may not have a substituent.

X ¹² is the same as X ¹¹ , and the preferred conditions are also the same.
L ¹² is the same as L ¹¹ and the preferred conditions are also the same.
Examples of —X ¹² —L ¹² — include L101 to L143, which are examples of L described above.

Y ¹² is a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms in which one or more methylene groups are substituted with -O-, -S-, -NH-, -N(CH ₃ )-, -CO-, -O-CO-, or -CO-O- represents a group.
Y ¹² is a linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms, or one linear, branched, or cyclic alkyl group having 1 to 20 carbon atoms or a group in which two or more methylene groups are substituted with -O-, -S-, -NH-, -N(CH ₃ )-, -CO-, -O-CO-, or -CO-O- In this case, one or more hydrogen atoms contained in Y ¹² may be substituted with halogen atoms.

Specific examples of the compound represented by formula (XI), paragraph numbers 0028 to 0036 of JP-A-7-281028, JP-A-7-306317, JP-A-2005-156822 paragraph numbers 0016 to 0018 , paragraph numbers 0067 to 0072 of JP-A-2006-301614, and liquid crystal handbook (published by Maruzen Co., Ltd. in 2000) pp. 330-333 in the compound described in at least one terminal (preferably three or more ) as an epoxy group.

The compound represented by formula (XI) is prepared according to the methods described in JP-A-7-306317, JP-A-7-281028, JP-A-2005-156822, and JP-A-2006-301614. can be synthesized by

In addition, from the viewpoint of better thermal conductivity of the thermally conductive material, the compound represented by the formula (D16) is also preferable as the discotic compound.

In formula (D16), A ^2X , A ^3X and A ^4X each independently represent -CH= or -N=. Among them, A ^2X , A ^3X and A ^4X are each independently preferably -CH=.
R ^17X , R ^18X and R ^19X each independently represent *-X ^211X -(Z ^21X -X ^212X ) _n21X -L ^21X -Q. * represents the bonding position with the central ring.
X ^211X and X ^212X are each independently a single bond, —O—, —CO—, —NH—, —O—CO—, —O—CO—O—, —O—CO—NH—, —O -CO-S-, -CO-O-, -CO-NH-, -CO-S-, -NH-CO-, -NH-CO-O-, -NH-CO-NH-, -NH-CO -S-, -S-, -S-CO-, -S-CO-O-, -S-CO-NH-, or -S-CO-S-.
Each Z ^21X independently represents a 5- or 6-membered aromatic ring group or a 5- or 6-membered non-aromatic ring group.
L ^21X represents a single bond or a divalent linking group.
Q has the same meaning as Q in formulas (D1) to (D15), and the preferred conditions are also the same. In formula (D16), at least one (preferably all) of the multiple Qs represents an epoxy group.
n21X represents an integer of 0-3. When n21X is 2 or more, a plurality of (Z ^21X -X ^212X ) may be the same or different.
However, the compound represented by formula (D16) preferably does not have —NH— from the viewpoint of the stability of the epoxy group.

As the compound represented by formula (D16), a compound represented by formula (XII) is preferable.

In formula (XII), A ² , A ³ and A ⁴ each independently represent -CH= or -N=. Among them, A ² , A ³ and A ⁴ are preferably -CH=. In other words, it is also preferred that the central ring of the discotic compound is a benzene ring.

R ¹⁷ , R ¹⁸ and R ¹⁹ are each independently *-X ²¹¹ -(Z ²¹ -X ²¹² ) _n21 -L ²¹ -P ²¹ or *-X ²²¹ -(Z ²² -X ²²² ) represents _n22 - ^Y22 . * represents the bonding position with the central ring.
Two or more of R ¹⁷ , R ¹⁸ and R ¹⁹ are *-X ²¹¹ -(Z ²¹ -X ²¹² ) _n21 -L ²¹ -P ²¹ . From the viewpoint of better thermal conductivity of the thermally conductive material, R ¹⁷ , R ¹⁸ and R ¹⁹ are all *-X ²¹¹ -(Z ²¹ -X ²¹² ) _n21 -L ²¹ -P ²¹ . preferable.
Additionally, it is preferred that R ¹⁷ , R ¹⁸ and R ¹⁹ are all the same.

X ²¹¹ , X ²¹² , X ²²¹ and X ²²² are each independently a single bond, -O-, -CO-, -NH-, -O-CO-, -O-CO-O-, -O -CO-NH-, -O-CO-S-, -CO-O-, -CO-NH-, -CO-S-, -NH-CO-, -NH-CO-O-, -NH-CO -NH-, -NH-CO-S-, -S-, -S-CO-, -S-CO-O-, -S-CO-NH-, or -S-CO-S-.
Among them, X ²¹¹ , X ²¹² , X ²²¹ and X ²²² are each independently preferably a single bond, -O-, -CO-O- or -O-CO-.

Z ²¹ and Z ²² each independently represent a 5- or 6-membered aromatic ring group or a 5- or 6-membered non-aromatic ring group, such as a 1,4-phenylene group , 1,3-phenylene groups, and aromatic heterocyclic groups.

The aromatic ring group and the non-aromatic ring group may have a substituent. The number of substituents is preferably 1 or 2, more preferably 1. The substitution position of the substituent is not particularly limited. A halogen atom or a methyl group is preferable as the substituent. It is also preferred that the aromatic ring group and the non-aromatic ring group are unsubstituted.

Examples of aromatic heterocyclic groups include the following aromatic heterocyclic groups.

In the formula, * represents a site that binds to ^X211 or ^X221 . ** represents the site that binds to ^X212 or ^X222 . A ⁴¹ and A ⁴² each independently represent a methine group or a nitrogen atom. ^X4 represents an oxygen atom, a sulfur atom, a methylene group, or an imino group.
At least one of A ⁴¹ and A ⁴² is preferably a nitrogen atom, more preferably both are nitrogen atoms. Also, ^X4 is preferably an oxygen atom.

When n21 and n22, which will be described later, are 2 or more, a plurality of (Z ²¹ -X ²¹² ) and (Z ²² -X ²²² ) may be the same or different.

Each L ²¹ independently represents a single bond or a divalent linking group, and has the same definition as L ¹¹ in formula (XI) above. L ²¹ is -O-, -O-CO-, -CO-O-, -S-, -NH-, an alkylene group (the number of carbon atoms is preferably 1 to 10, more preferably 1 to 8, 1 to 7 are more preferable), an arylene group (the number of carbon atoms is preferably 6 to 20, more preferably 6 to 14, and even more preferably 6 to 10), or a group consisting of a combination thereof.

When n22, which will be described later, is 1 or more, examples of -X ²¹² -L ²¹ - include L101 to L143, which are examples of L in formulas (D1) to (D15) above.

^P21 represents an epoxy group. The epoxy group may or may not have a substituent.

Y ²² is each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or a linear, branched or cyclic alkyl group having 1 to 20 carbon atoms, or 1 or 2 or more methylene groups in the cyclic alkyl group are -O-, -S-, -NH-, -N(CH ₃ )-, -CO-, -O-CO- or -CO- represents a group substituted with O--, has the same meaning as Y ¹² in general formula (XI), and the preferred range is also the same.

Each of n21 and n22 independently represents an integer of 0 to 3, preferably an integer of 1 to 3, more preferably 2 to 3, from the viewpoint of better thermal conductivity.

Preferred examples of the discotic compound include the following compounds.

In the following structural formula, R represents -X ²¹² -L ²¹ -P ²¹ .

For details and specific examples of the compound represented by formula (XII), in the compound described in paragraphs 0013 to 0077 of JP-A-2010-244038, at least one terminal (preferably three or more) is epoxy Reference can be made to the underlying compounds, the contents of which are incorporated herein.

The compound represented by formula (XII) can be synthesized according to the methods described in JP-A-2010-244038, JP-A-2006-76992, and JP-A-2007-2220.

The discotic compound is also preferably a compound having a hydrogen-bonding functional group, from the viewpoint of reducing electron density to strengthen stacking and facilitating the formation of columnar aggregates. Hydrogen-bonding functional groups include -O-CO-NH-, -CO-NH-, -NH-CO-, -NH-CO-O-, -NH-CO-NH-, -NH-CO-S -, or -S-CO-NH- and the like.

(Other epoxy compounds)
Other epoxy compounds other than the epoxy compounds described above include, for example, epoxy compounds represented by general formula (DN).

In general formula (DN), n ^DN represents an integer of 0 or more, preferably 0 to 5, more preferably 1.
R ^DN represents a single bond or a divalent linking group. The divalent linking group includes -O-, -O-CO-, -CO-O-, -S-, an alkylene group (having preferably 1 to 10 carbon atoms), an arylene group (having a carbon number of 6 to 20 are preferred.) or a group consisting of a combination thereof, more preferably an alkylene group, and more preferably a methylene group.

Other epoxy compounds include compounds in which the epoxy group is ring-condensed. Examples of such compounds include 3,4:8,9-diepoxybicyclo[4.3.0]nonane and the like.

Other epoxy compounds include, for example, bisphenol A-type epoxy compounds, bisphenol F-type epoxy compounds, bisphenol S-type epoxy compounds, and bisphenol AD-type epoxy compounds, which are glycidyl ethers of bisphenol A, F, S, and AD. etc.; hydrogenated bisphenol A-type epoxy compound, hydrogenated bisphenol AD-type epoxy compound, etc.; A novolac type glycidyl ether, etc.; dicyclopentadiene type glycidyl ether (dicyclopentadiene type epoxy compound); dihydroxypentadiene type glycidyl ether (dihydroxypentadiene type epoxy compound); polyhydroxybenzene type glycidyl ether (polyhydroxybenzene type epoxy compounds); benzenepolycarboxylic acid-type glycidyl esters (benzenepolycarboxylic acid-type epoxy compounds); and trisphenolmethane-type epoxy compounds.

An epoxy compound may be used individually by 1 type, and may use 2 or more types.

The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenolic compound in the composition (number of epoxy groups/number of phenolic hydroxyl groups) is 40/60 to 60/40. , 45/55 to 55/45 are preferred.
In other words, the content ratio of the phenolic compound to the epoxy compound in the composition is preferably such that the "number of epoxy groups/number of phenolic hydroxyl groups" is within the above range.

In addition, in the composition, the equivalent ratio of the epoxy group of the epoxy compound to the active hydrogen (which may be an active hydrogen derived from a phenolic hydroxyl group or an active hydrogen of another active hydrogen-containing compound) ( The ratio (number of epoxy groups/number of active hydrogens) is preferably 30/70 to 70/30, more preferably 40/60 to 60/40, and even more preferably 45/55 to 55/45.

Further, the total content of the epoxy compound and the phenol compound in the composition is preferably 5 to 100% by mass, more preferably 60 to 100% by mass, and 90 to 100% by mass, based on the total solid content of the composition. is more preferred.
In addition, the total solid content intends the components forming the thermally conductive material, and does not include the solvent. The component forming the thermally conductive material referred to here may be a component that reacts (polymerizes) to change its chemical structure when forming the thermally conductive material. In addition, as long as it is a component that forms a thermally conductive material, it is regarded as a solid content even if its property is liquid.

<Filler>
The composition does not contain a filler, or when it contains the filler, the content of the filler is 10% by mass or less (preferably 5% by mass or less, based on the total solid content of the composition). more preferably 1% by mass or less, still more preferably 0.1% by mass or less).

The filler may be inorganic (inorganic filler such as inorganic nitride such as boron nitride) or organic (organic filler). The filler in the composition of the present invention is solid at the temperature (for example, 150 ° C.) at which the composition is cured (precuring treatment and / or main curing treatment), and exists without being dissolved with other components in the composition. It is a component that

<Curing accelerator>
The composition may further contain a curing accelerator. That is, the thermally conductive material of the present invention may be a cured product containing a curing accelerator.
Examples of curing accelerators include triphenylphosphine, boron trifluoride amine complexes, and compounds described in paragraph 0052 of JP-A-2012-67225. In addition, 2-methylimidazole (trade name; 2MZ), 2-undecylimidazole (trade name; C11-Z), 2-heptadecylimidazole (trade name; C17Z), 1,2-dimethylimidazole (trade name) ; 1.2DMZ), 2-ethyl-4-methylimidazole (trade name; 2E4MZ), 2-phenylimidazole (trade name; 2PZ), 2-phenyl-4-methylimidazole (trade name; 2P4MZ), 1-benzyl -2-methylimidazole (trade name; 1B2MZ), 1-benzyl-2-phenylimidazole (trade name; 1B2PZ), 1-cyanoethyl-2-methylimidazole (trade name; 2MZ-CN), 1-cyanoethyl-2- undecylimidazole (trade name; C11Z-CN), 1-cyanoethyl-2-phenylimidazolium trimellitate (trade name; 2PZCNS-PW), 2,4-diamino-6-[2'-methylimidazolyl-(1 ')]-ethyl-s-triazine (trade name; 2MZ-A), 2,4-diamino-6-[2'-undecylimidazolyl-(1')]-ethyl-s-triazine (trade name; C11Z -A), 2,4-diamino-6-[2′-ethyl-4′-methylimidazolyl-(1′)]-ethyl-s-triazine (trade name; 2E4MZ-A), 2,4-diamino- 6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazineisocyanuric acid adduct (trade name; 2MA-OK), 2-phenyl-4,5-dihydroxymethylimidazole (trade name; 2PHZ- PW), 2-phenyl-4-methyl-5-hydroxymethylimidazole (trade name; 2P4MHZ-PW), 1-cyanoethyl-2-phenylimidazole (trade name; 2PZ-CN), 2,4-diamino-6- [2′-methylimidazolyl-(1′)]-ethyl-s-triazine (trade name; 2MZA-PW) and 2,4-diamino-6-[2′-methylimidazolyl-(1′)]- Examples include imidazole-based curing accelerators such as ethyl-s-triazine isocyanuric acid adduct (trade name: 2MAOK-PW) (all manufactured by Shikoku Kasei Kogyo Co., Ltd.). Furthermore, the compounds described in paragraph 0052 of JP-A-2004-43405 are also included as triarylphosphine-based curing accelerators. Examples of phosphorus-based curing accelerators in which triphenylborane is added to triarylphosphine include compounds described in paragraph 0024 of JP-A-2014-5382.
A single curing accelerator may be used alone, or two or more curing accelerators may be used.
The content of the curing accelerator is preferably 0.01 to 10% by mass, more preferably 0.10 to 5% by mass, based on the total epoxy compound.

<Solvent>
The composition may further contain a solvent.
The type of solvent is not particularly limited, and an organic solvent is preferred. Examples of organic solvents include cyclopentanone, cyclohexanone, ethyl acetate, methyl ethyl ketone, dichloromethane, and tetrahydrofuran.
When the composition contains a solvent, the content of the solvent is preferably an amount that makes the solid content concentration of the composition 5 to 100% by mass, more preferably 10 to 70% by mass, and 15 to 50% by mass. is more preferable.

<Method for producing composition>
A method for producing the composition is not particularly limited, and a known method can be employed. For example, the composition can be produced by mixing the various components described above. When mixing, various components may be mixed together or may be mixed sequentially.
There is no particular limitation on the method of mixing the components, and known methods can be used. The mixing device used for mixing is preferably a submerged disperser, especially when the composition contains a filler. Jet dispersers, ultrasonic dispersers, bead mills, and homogenizers are included. One type of mixing device may be used alone, or two or more types may be used. Degassing may be performed before, after and/or at the same time as mixing.

[Thermal conductive material and its production]
The production method of the present invention is to cure the composition described above by a predetermined method.
The production method of the present invention includes the following steps.
- Under no pressure, pre-curing the composition so that 1 to 90% of the phenol compound remains, based on the measurement method using high-performance liquid chromatography, and pre-curing. A pre-curing step to obtain the object.
- A main curing step of subjecting the pre-cured material to a main curing treatment under a pressure of 0.1 MPa or more to obtain a heat conductive material.
The preliminary curing step and the main curing step will be described in detail below.

<Pre-curing step>
In the pre-curing step, the phenol compound and epoxy compound in the composition are polymerized (pre-curing treatment).
Pre-curing treatment, based on the measurement method using high performance liquid chromatography, 1 to 90% (preferably 10 to 90%, preferably 20 to 80%, more preferably 35 to 90%) of the phenol compounds in the composition 75%) remains.
The term "residual phenol compound" as used herein means an unreacted phenol compound (a phenol compound that has not undergone a polymerization reaction due to the pre-curing treatment) in the pre-cured product, and is also referred to as residual phenol. That is, in the preliminary curing treatment, the content of residual phenol (residual phenol content) is 1 to 90% (preferably 10 to 90%, preferably 10 to 90%, preferably 20-80%, more preferably 35-75%).
In other words, in the pre-curing step, a pre-cured product having a residual phenol content of 1 to 90% (preferably 10 to 90%, preferably 20 to 80%, more preferably 35 to 75%) is obtained.

Here, the amount of residual phenol is determined by the following method using high performance liquid chromatography.
That is, first, 0.5 g of the solid content of the composition before treatment and the pre-cured product are immersed in 30 ml of THF (tetrahydrofuran) at 25 ° C. for 1 hour to elute or dissolve unreacted phenol compounds in THF, respectively. .
The unreacted phenolic compound-dissolved THF obtained in this way is analyzed by high performance liquid chromatography (HPLC), and the solid content of the composition before precuring treatment or the precured product is derived from unreacted phenolic compounds. Obtain the peak area for each.
Based on the peak area derived from the unreacted phenol compound in the solid content of the composition before the pre-curing treatment and the peak area derived from the unreacted phenol compound in the pre-cured product, based on the following formula, in the pre-cured product The content of unreacted phenol compounds (residual phenol amount) in is calculated.
Content of unreacted phenolic compounds (residual phenol amount, %) = 100 × peak area derived from unreacted phenolic compounds in precured product / unreacted phenolic compounds in solid content of composition before precuring treatment Derived peak area When the composition contains a solvent, the solid content of the composition before pre-curing treatment is obtained by drying (drying under reduced pressure) or the like on the composition.

The pre-curing treatment is performed, for example, in a state in which the composition is applied onto a substrate to form a coating film.
The film thickness of the composition used as a coating film may be appropriately adjusted in accordance with the thermally conductive material to be produced.
Further, when the composition contains a solvent, the pre-curing treatment may be performed after evaporating the solvent in the composition at room temperature (e.g., 25 ° C.), or the composition applied during the pre-curing treatment Drying off of the solvent in (such as the coating) may be done at the same time.
In the pre-curing treatment, the composition (coating film, etc.) is often heated to promote polymerization. At this time, the heating temperature is preferably 50 to 250.degree. C., more preferably 100 to 200.degree. C., and still more preferably 110 to 160.degree. The heating time is preferably 0.5 to 20 minutes, more preferably 1 to 10 minutes, even more preferably 2 to 8 minutes. In addition, the said heating may be performed continuously and may be performed intermittently. Heat treatment with different temperatures may be performed multiple times.

Precuring treatment is performed without pressure.
The term "no pressure" as used herein means substantially no pressure. It is sufficient that the load continuously applied to is less than 0.1 MPa (preferably 0.01 MPa or less, more preferably 0.001 MPa or less).
In addition, substantially no pressure means, for example, that the composition (coating film, etc.) is not continuously pressurized while the polymerization of the composition (coating film, etc.) is progressing. To give a specific example, the time during which pressure (for example, pressure of 0.1 MPa or more) is applied while the composition (coating film, etc.) is heated at the heating temperature is 5 of the heating time. % or less (preferably 1% or less).

The pre-cured product is preferably in the form of a film or sheet. Specifically, for example, the composition may be coated to form a film, and the composition (coating film) formed by coating may be subjected to a pre-curing treatment.

<Main curing process>
In the main curing step, under a pressure of 0.1 MPa or more (preferably 0.1 to 25.0 MPa, more preferably 0.5 to 10 MPa), the pre-cured product obtained in the above-described pre-curing step is subjected to main curing. to obtain a thermally conductive material.
While the pre-cured product is further subjected to the main curing treatment (polymerization) by applying the above pressure, the pre-cured product is often heated to accelerate the polymerization.
At this time, the heating temperature is preferably 50 to 250.degree. C., more preferably 100 to 220.degree. C., even more preferably 150 to 200.degree.
The pressurization time (preferably the pressurization time accompanied by heating) is preferably 0.5 to 20 minutes, more preferably 1 to 10 minutes, and even more preferably 2 to 8 minutes. In addition, the said heating may be performed continuously and may be performed intermittently. In the main curing treatment, heat treatment at different temperatures may be performed multiple times.

There are no restrictions on the pressurization method, and it is preferable to use a method that can apply pressure continuously. Pressing may be performed using, for example, a flat plate press.
A roll press may also be used.

The main curing treatment may be performed on the same base material as the base material used to form the pre-cured product, or may be performed by separating the base material from part or all of the pre-cured product. good. Further, the main curing treatment may be performed while the pre-cured product is in contact with a base material different from the base material used to form the pre-cured product.
Alternatively, for example, two sheets of the pre-cured material may be pasted together to form one sheet of the pre-cured material, and then the main curing treatment may be performed.

The main curing treatment may be completed when the composition is converted into a so-called B-stage semi-cured product (preferably, a semi-cured film). In other words, the thermally conductive material (thermally conductive material obtained in the main curing step) in the present invention can be a semi-cured thermally conductive material (semi-cured thermally conductive material) or a fully cured material (a heat conductive material other than the semi-cured material). conductive materials).

The degree of progress of the main curing treatment is, for example, the ratio of the peak intensity at 910 cm ^-1 to the peak intensity at 1610 cm ^-1 (peak intensity at 910 cm ^-1 /peak intensity at 1610 cm ^-1 ) in infrared spectroscopic analysis. I can judge.
The peak at 910 cm ⁻¹ is derived from an epoxy group, and the peak at 1610 cm ⁻¹ is derived from an aromatic ring group.
Hereinafter, the ratio of the peak intensity at 910 cm ⁻¹ to the peak intensity at 1610 cm ⁻¹ (peak intensity at 910 cm ⁻¹ /peak intensity at 1610 cm ⁻¹ ) is also referred to as specific peak intensity ratio.
In addition, in the present invention, the infrared spectroscopic analysis can be performed by an ATR (Attenuated Total Reflection) method.

For example, the main curing treatment is preferably performed so that the specific peak intensity ratio of the cured product (thermally conductive material) is 0.06 or less, more preferably 0.03 or less, It is more preferable to carry out so that it becomes 0.01 or less. The lower limit is 0.00.
That is, for example, in the present invention, the heat conductive material is a heat conductive material obtained by curing the above composition, and the specific peak intensity ratio is preferably 0.06 or less, and 0.03 or less. It is more preferably 0.01 or less. The lower limit is 0.00.
However, when obtaining a thermally conductive material that is a semi-cured material in a B-stage state, the main curing treatment is performed so that the specific peak intensity ratio of the cured product (thermally conductive material) is more than 0.01 and 0.06 or less. It is also preferable to implement
That is, for example, in the present invention, the thermally conductive material that is a B-stage semi-cured material is a thermally conductive material obtained by curing the composition described above, and has a specific peak intensity ratio of more than 0.01 to 0.01. 06 or less is also preferable.

Further, the main curing treatment is preferably carried out so that the amount of residual epoxy is 35% by mass or less (preferably 15% by mass or less, more preferably 5% by mass or less; the lower limit is 0% by mass).
The amount of residual epoxy is the ratio of the specific peak intensity ratio of the thermally conductive material obtained through the main curing treatment when the specific peak intensity ratio of the solid content of the composition before performing the preliminary curing treatment is 100% ( Remaining epoxy amount (% by mass)=specific peak intensity ratio of thermally conductive material/specific peak intensity ratio of solid content of composition×100).
That is, for example, in the present invention, the thermally conductive material is a thermally conductive material obtained by curing the above composition, and the amount of residual epoxy is 35% by mass or less (preferably 15% by mass or less, more preferably 5% by mass). % or less.The lower limit is preferably 0% by mass).
However, when obtaining a thermally conductive material that is a semi-cured material in a B-stage state, the main curing step is preferably carried out so that the amount of residual epoxy is more than 5% by mass and 35% by mass or less.
That is, for example, in the present invention, the thermally conductive material that is a B-stage semi-cured material is a thermally conductive material obtained by curing the above composition, and the amount of residual epoxy is more than 5% by mass and 35% by mass or less. is preferred.
The specific peak intensity ratio of the solid content of the composition before the preliminary curing step is preferably more than 0.06 and 0.50 or less, more preferably 0.08 to 0.25.

The shape of the heat conductive material is not particularly limited, and can be molded into various shapes depending on the application. A typical shape of the molded thermally conductive material includes, for example, a sheet shape.
In other words, the thermally conductive material is preferably a thermally conductive sheet.
The film thickness of the sheet-shaped thermally conductive material (thermally conductive sheet) is, for example, 25 to 800 μm. In order to obtain a sheet-like thermally conductive material (thermally conductive sheet) with a desired film thickness, a formwork may be used to perform preliminary curing treatment and/or main curing treatment.
Also, the thermal conductivity of the thermally conductive material is preferably isotropic rather than anisotropic.

[Applications of thermally conductive materials]
The thermally conductive material can be used as a heat dissipation material such as a heat dissipation sheet, and can be used for heat dissipation of various devices. More specifically, a heat conductive layer containing the above heat conductive material (preferably a heat conductive sheet) is placed on the device to produce a device with a heat conductive layer, and the heat generated from the device is efficiently transferred to the heat conductive layer. can dissipate heat.
Since the above thermal conductive material has sufficient thermal conductivity and high heat resistance, it is used for heat dissipation of power semiconductor devices used in various electrical equipment such as personal computers, general home appliances, and automobiles. Suitable for
Furthermore, since the heat conductive material has sufficient heat conductivity even in a semi-cured state, it is placed in areas where light for photocuring is difficult to reach, such as gaps between members of various devices. It can also be used as a heat dissipation material. After the semi-cured heat conductive material is placed in contact with the device or the like to be used, curing may be further advanced by heating or the like, and post-curing may be performed. It is also preferable that the device and the thermally conductive material are adhered by heating or the like during the post-curing.

The thermally conductive material may be used in combination with other members other than members formed from the composition.
For example, a sheet-shaped thermally conductive material (thermally conductive sheet) may be combined with a sheet-shaped support other than the layer formed from the composition described above.
Sheet-like supports include plastic films, metal films, and glass plates. Examples of plastic film materials include polyesters such as polyethylene terephthalate (PET), polycarbonates, acrylic resins, epoxy resins, polyurethanes, polyamides, polyolefins, cellulose derivatives, and silicones. Metal films include copper films.

The present invention will be described in more detail based on examples below. The materials, amounts used, proportions, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limited by the examples shown below.

[Preparation and Evaluation of Thermal Conductive Material]
[Composition for Forming Thermal Conductive Material]
Various components in the thermally conductive material-forming compositions (compositions) used for the production of the thermally conductive materials produced in Examples and Comparative Examples are shown below.
<Phenol compound>
The phenolic compounds used in the preparation of the composition are shown below.
Compounds A-1 and A-2 correspond to compounds represented by general formula (P1).

<Epoxy compound>
The phenolic compounds used in the preparation of the composition are shown below.
B-3 below is a mixture of two types of epoxy compounds (trade name: Epotato ZX-1059, manufactured by Tohto Kasei Co., Ltd.).
B-8 below is EPPN-201 manufactured by Nippon Kayaku Co., Ltd.

<Curing accelerator>
PPh ₃ (triphenylphosphine) was used as curing accelerator.

<Solvent>
Cyclopentanone was used as solvent.

[Preparation of composition]
A mixture was prepared by blending the epoxy compound and the phenolic compound in the combinations shown in Table 1 below so that the ratio of the number of epoxy groups to the number of phenolic hydroxyl groups in the system satisfies the relationship shown in Table 1 below. .
The mixture, the solvent, and the curing accelerator were mixed in this order to obtain a composition (composition for forming a thermally conductive material) of each example or comparative example.
The amount of the solvent was adjusted so that the solid content concentration of the composition was 30% by mass.
The amount of the curing accelerator added was such that the content of the curing accelerator in the composition was 1% by mass with respect to the content of the epoxy compound.

[Preparation of heat conductive material]
<Example 1>
A frame is placed on the release surface of a release-treated polyester film (NP-100A manufactured by Panac, film thickness 100 μm), and the prepared composition of Example 1 is introduced inside the frame using an applicator. and left at 120° C. for 5 minutes to obtain a film-like pre-cured product (pre-curing step).
The amount of residual phenol of the resulting precured product was measured by the method described in the specification, and the results are shown in Table 1.
Subsequently, the pre-cured material in the frame was hot-pressed in air (hot plate temperature 180° C., pressure 1 MPa for 1 minute) to obtain a resin sheet (main curing step).
The polyester films on both sides of the resin sheet were peeled off to obtain a thermally conductive sheet with an average thickness of 100 µm.
In addition, the composition used and the obtained thermally conductive sheet ^{(thermally conductive material) were subjected to infrared spectroscopic analysis by the method described in the specification, with respect to the peak intensity at 1610 cm -1 .} The intensity ratio (specific peak intensity ratio) was as shown in Table 1. Table 1 also shows the amount of residual epoxy in the thermally conductive sheet (thermally conductive material) determined by the method described in the specification.

<Examples 2 to 14 and Comparative Example 3>
The heat conductive sheets of Examples 2 to 14 and Comparative Example 3 (heat conductive material) was obtained.

<Comparative Example 1>
A thermally conductive sheet (thermally conductive material) of Comparative Example 1 was obtained in the same manner as in Example 1, except that the preliminary cured product was not pressurized in the main curing step.
In addition, after obtaining the thermally conductive sheet (thermally conductive material) of Comparative Example 1, even if further heating is continued under the same conditions for 1 hour, the specific peak intensity ratio of the thermally conductive material before and after the further heating And there was no change in the amount of residual epoxy.

<Comparative Example 2>
Inside the frame, after introducing the prepared composition of Example 1 and evaporating the solvent in the composition at room temperature (25 ° C.), the resulting coating film was subjected to the pre-curing step without A thermally conductive sheet (thermally conductive material) of Comparative Example 2 was obtained in the same manner as in Example 1, except that the main curing step was performed.
In addition, after obtaining the heat conductive sheet (heat conductive material) of Comparative Example 2, even if further heat pressing is continued under the same conditions for 1 hour, before and after the further heat pressing, the specific peak of the heat conductive material There was no change in strength ratio and residual epoxy amount.

[evaluation]

<Thermal conductivity>
Thermal conductivity evaluation was performed using each thermally conductive sheet of each example or comparative example. Thermal conductivity was measured by the following method, and thermal conductivity was evaluated according to the following criteria.

(Measurement of thermal conductivity (W/m·k))
(1) Using "LFA467" manufactured by NETZSCH, the thermal diffusivity in the thickness direction of the thermally conductive sheet was measured by the laser flash method.
(2) Using a balance "XS204" manufactured by Mettler Toledo, the specific gravity of the thermally conductive sheet was measured by the Archimedes method (using the "solid specific gravity measurement kit").
(3) Using "DSC320/6200" manufactured by Seiko Instruments Inc., the specific heat of the thermally conductive sheet at 25°C was determined under the condition of temperature increase of 10°C/min.
(4) The obtained thermal diffusivity was multiplied by the specific gravity and the specific heat to calculate the thermal conductivity of the thermally conductive sheet.

(Evaluation criteria)
The measured thermal conductivity was classified according to the following criteria, and the thermal conductivity was evaluated.
"A": 0.4 W/m·K or more "B": 0.3 W/m·K or more and less than 0.4 W/m·K "C": 0.2 W/m·K or more and 0.3 W/m·K Less than K "D": less than 0.2 W/m・K

[result]
Table 1 below shows the relationship between the characteristics of the composition and the manufacturing method and the test results.
In the table, the "number of functional groups (mmol/g)" column indicates the phenolic hydroxyl group content (mmol/g) of the phenol compound used.
The "epoxy group/phenolic hydroxyl group" column indicates the ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenolic compound in the composition (number of epoxy groups/number of phenolic hydroxyl groups). indicates
The "pre-curing" column indicates whether or not the pre-curing step was performed.
"Residual phenol amount (mass%)" column is derived from unreacted phenol compounds in the pre-cured product with respect to the HPLC peak area (100%) derived from unreacted phenol compounds in the solid content of the composition before treatment It means (residual phenol amount, mass%) obtained from the ratio of HPLC peak areas.
The "curing pressure" column indicates the pressure applied in the main curing step.
The "Before curing (composition)" column in the "Specific peak intensity ratio" column shows the specific peak intensity ratio when the solid content of the composition before the preliminary curing step was analyzed by infrared spectroscopy.
The column "After curing (thermally conductive material)" in the column "Specific peak intensity ratio" indicates the specific peak intensity ratio of the thermally conductive material obtained in the main curing step.
The "remaining epoxy amount (mass %)" column shows the residual epoxy amount of the thermally conductive material.

From the results shown in the table, it was confirmed that a thermally conductive material having excellent thermal conductivity can be obtained by using the production method of the present invention.

The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenolic compound (the number of epoxy groups / the number of phenolic hydroxyl groups ) was confirmed to be preferably 45/55 to 55/45 (see comparison of results of Examples 1 and 14, etc.).

It was confirmed that the pressure applied in the main curing step is preferably 0.5 to 10 MPa in terms of obtaining a thermally conductive material with more excellent thermal conductivity (see comparison of results of Examples 1 and 2, etc.).

It has been confirmed that the main curing step is more preferably carried out so that the specific peak intensity ratio of the thermally conductive material is 0.00 to 0.01, in that a thermally conductive material with more excellent thermal conductivity can be obtained. rice field. In other words, it was confirmed that the specific peak intensity ratio of the thermally conductive material is preferably 0.00 to 0.01 (see comparison of results of Examples 1 and 14, etc.).

It has been confirmed that the main curing step is more preferably carried out so that the amount of residual epoxy in the thermally conductive material is 0 to 5% by mass, in that a thermally conductive material with better thermal conductivity can be obtained. In other words, it was confirmed that the specific peak intensity ratio of the thermally conductive material is preferably 0-5% (see, for example, the comparison of the results of Examples 1 and 14).

Claims (11)

A phenol compound containing a compound represented by the general formula (P2) or a compound represented by the general formula (P3), and an epoxy compound,
The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenol compound is 40/60 to 60/40,
Using a composition for forming a thermally conductive material, which does not contain a filler, or when the filler is contained, the content of the filler is 10% by mass or less with respect to the total solid content, A method for manufacturing a thermally conductive material, comprising:
Under no pressure, the composition for forming a thermally conductive material is precured so that 1 to 90% of the phenol compound remains, based on a measurement method using high-performance liquid chromatography. to obtain a pre-cured product, a pre-curing step, and
A method for producing a thermally conductive material, comprising a final curing step of subjecting the precured product to a final curing treatment under a pressure of 0.1 MPa or more to obtain a thermally conductive material.

m1 represents 1 in general formula (P2) and general formula (P3).
nc represents 1;
nd represents 1 ;
Q ^a represents an alkyl group having 1 to 10 carbon atoms .
L ^x1 and L ^x2 represent —CH ₂ — . 2. The method for producing a thermally conductive material according to claim 1, wherein in the main curing step, the pre-cured product is subjected to the main curing treatment under a pressure of 0.5 to 10 MPa. 3. Production of the thermally conductive material according to claim 1 or 2, wherein the compound represented by the general formula (P2) and the compound represented by the general formula (P3) have a hydroxyl group content of 12.0 mmol/g or more. Method. The method for producing a thermally conductive material according to any one of claims 1 to 3, wherein the compound represented by the general formula (P2) and the compound represented by the general formula (P3) have a molecular weight of 400 or less. . The method for producing a thermally conductive material according to any one of claims 1 to 4, wherein the thermally conductive material-forming composition further contains a curing accelerator. A phenol compound containing a compound represented by the general formula (P2) or a compound represented by the general formula (P3), and an epoxy compound,
The ratio of the number of epoxy groups contained in the epoxy compound to the number of phenolic hydroxyl groups contained in the phenol compound is 40/60 to 60/40,
A composition for forming a thermally conductive material that does not contain a filler or, if it contains the filler, has a content of the filler of 10% by mass or less with respect to the total solid content is cured. A thermally conductive material comprising
A thermally conductive material having a ratio of peak intensity at 910 cm ⁻¹ to peak intensity at 1610 cm ⁻¹ of 0.06 or less when analyzed by infrared spectroscopy.

m1 represents 1 in general formula (P2) and general formula (P3).
nc represents 1;
nd represents 1 ;
Q ^a represents an alkyl group having 1 to 10 carbon atoms .
L ^x1 and L ^x2 represent —CH ₂ — . 7. The thermally conductive material according to claim 6, wherein the compound represented by the general formula (P2) and the compound represented by the general formula (P3) have a hydroxyl group content of 12.0 mmol/g or more. 8. The thermally conductive material according to claim 6, wherein the compound represented by the general formula (P2) and the compound represented by the general formula (P3) have a molecular weight of 400 or less. The thermally conductive material according to any one of claims 6 to 8, further comprising a curing accelerator. A thermally conductive sheet made of the thermally conductive material according to any one of claims 6 to 9. A device with a thermally conductive layer, comprising: a device; and a thermally conductive layer comprising the thermally conductive sheet according to claim 10 disposed on the device.