JP7245953B2 - COMPOSITION FOR FORMING HEAT CONDUCTIVE MATERIAL, HEAT CONDUCTIVE SHEET, HEAT CONDUCTIVE MULTILAYER SHEET, AND DEVICE WITH HEAT CONDUCTIVE LAYER - Google Patents

Description

TECHNICAL FIELD The present invention relates to a composition for forming a thermally conductive material, a thermally conductive sheet, a thermally conductive multilayer 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 a thermally conductive material containing a compound represented by the following general formula (XII) as a thermally conductive material used in a heat dissipation sheet ([Claim 1] [Claim 8 ] [Claim 19] [Claim 20])

WO2017/131007

The present inventors have investigated a compound having a triazine ring in which each of A ² , A ³ and A ⁴ in the general formula (XII) is -N= and which has a thermally conductive material described in Patent Document 1. , found that there is room for improvement in terms of thermal conductivity.

Accordingly, an object of the present invention is to provide a composition for forming a thermally conductive material having excellent thermal conductivity.
Another object of the present invention is to provide a thermally conductive sheet, a thermally conductive multilayer sheet, and a device with a thermally conductive layer formed from the above composition.

The present inventors have found that the thermal conductivity of the formed thermally conductive material is improved by using a composition for forming a thermally conductive material containing a compound having two or more triazine rings, and have completed the present invention. let me
That is, the inventors have found that the above object can be achieved by the following configuration.

上記一般式（１）中、
Ｅ^１～Ｅ^６は、それぞれ独立に、単結合、－ＮＨ－、又は、－ＮＲ－を表す。Ｒは、置換基を表す。
Ｂ^１、Ｂ^２、Ｂ^３、及びＢ^４は、それぞれ、ｋ＋１価、ｌ＋１価、ｍ＋１価、及びｎ＋１価の有機基を表し、それらの少なくとも１つが、置換基を有していてもよいｋ＋１価、ｌ＋１価、ｍ＋１価、又は、ｎ＋１価の芳香環基を表す。
Ｌは、２価の有機基を表す。
ｋ、ｌ、ｍ、及び、ｎは、それぞれ独立に、０以上の整数を表す。
ｋが２以上の場合、ｋ個存在するＸ^１は、それぞれ同一でも異なっていてもよい。
ｌが２以上の場合、ｌ個存在するＸ^２は、それぞれ同一でも異なっていてもよい。
ｍが２以上の場合、ｍ個存在するＸ^３は、それぞれ同一でも異なっていてもよい。
ｎが２以上の場合、ｎ個存在するＸ⁴は、それぞれ同一でも異なっていてもよい。
また、ｋ、ｌ、ｍ、及び、ｎの合計は２以上である。
Ｘ^１～Ｘ⁴は、それぞれ独立に、一般式（２）で表される基を表す。

上記一般式（２）中、＊は、結合位置を表す。
Ｄ^１は、単結合又は２価の連結基を表す。
Ａ^１は、置換基を有していてもよい芳香環基、又は、置換基を有していてもよい脂肪族環基を表す。
Ｑ及びＹ^１は、それぞれ独立に、水酸基、エポキシ基を有する１価の基、アミノ基、チオール基、カルボン酸基、イソシアネート基、及び、オキセタニル基を有する１価の基からなる群から選択される特定官能基を表す。
ｐは、０以上の整数を表す。
ｑは、０～２の整数を表す。
上記一般式（２）中、Ｄ^１が複数存在する場合、複数存在するＤ^１は、それぞれ同一でも異なっていてもよい。Ａ^１が複数存在する場合、複数存在するＡ^１は、それぞれ同一でも異なっていてもよい。Ｑが複数存在する場合、複数存在するＱは、それぞれ同一でも異なっていてもよい。
ｒは、１以上の整数である。
［２］ 上記一般式（１）中のＬが、置換基を有していてもよい２価の芳香環基、置換基を有していてもよい２価の脂肪族環基、及び、炭素数２以上の分岐を有していてもよいアルキレン基からなる群から選択される少なくとも１種を有する２価の有機基である、［１］に記載の熱伝導材料形成用組成物。
［３］ 上記一般式（１）中のＬが、置換基を有していてもよい２価の芳香環基を有する２価の有機基である、［１］又は［２］に記載の熱伝導材料形成用組成物。
［４］ 上記一般式（１）で表される化合物のハンセン溶解度パラメーター値が２８ＭＰａ^０．５以下である、［１］～［３］のいずれかに記載の熱伝導材料形成用組成物。
［５］ 上記一般式（１）で表される化合物のハンセン溶解度パラメーター値が２６ＭＰａ^０．５以下である、［１］～［４］のいずれかに記載の熱伝導材料形成用組成物。
［６］ 更に、硬化促進剤を含む、［１］～［５］のいずれかに記載の熱伝導材料形成用組成物。
［７］ 上記無機粒子が、無機窒化物である、［１］～［６］のいずれかに記載の熱伝導材料形成用組成物。
［８］ 上記無機粒子が、窒化ホウ素である、［１］～［７］のいずれかに記載の熱伝導材料形成用組成物。
［９］ 上記熱伝導材料形成用組成物の全固形分に対して、上記一般式（１）で表される化合物の含有量が３～４０質量％である、［１］～［８］のいずれかに記載の熱伝導材料形成用組成物。
［１０］ ［１］～［９］のいずれかに記載の熱伝導材料形成用組成物を硬化して形成される熱伝導シート。
［１１］ ［１０］に記載の上記熱伝導シートと、
上記熱伝導シートの片面又は両面に設けられた、接着剤層又は粘着剤層と、を有する、熱伝導性多層シート。
［１２］ 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又は［１１］に記載の熱伝導性多層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 composition for forming a thermally conductive material, containing inorganic particles and a compound represented by formula (1).

In the above general formula (1),
E ¹ to E ⁶ each independently represent a single bond, -NH- or -NR-. R represents a substituent.
B ¹ , B ² , B ³ , and B ⁴ each represent a k+1-valent, l+1-valent, m+1-valent, and n+1-valent organic group, at least one of which optionally has a substituent k+1 represents a valent, l+1-valent, m+1-valent, or n+1-valent aromatic ring group.
L represents a divalent organic group.
k, l, m, and n each independently represent an integer of 0 or greater.
When k is 2 or more, k X ¹ 's may be the same or different.
When l is 2 or more, l occurrences of X ² may be the same or different.
When m is 2 or more, m X ³ may be the same or different.
When n is 2 or more, n occurrences of X ⁴ may be the same or different.
Also, the sum of k, l, m, and n is 2 or more.
X ¹ to X ⁴ each independently represent a group represented by general formula (2).

In the above general formula (2), * represents a bonding position.
D ¹ represents a single bond or a divalent linking group.
A ¹ represents an optionally substituted aromatic ring group or an optionally substituted aliphatic ring group.
Q and Y ¹ are each independently selected from the group consisting of a monovalent group having a hydroxyl group, an epoxy group, an amino group, a thiol group, a carboxylic acid group, an isocyanate group, and a monovalent group having an oxetanyl group. represents a specific functional group.
p represents an integer of 0 or more.
q represents an integer of 0 to 2;
In the above general formula (2), when there are a plurality of D ¹ 's, the plurality of D ¹ 's may be the same or different. When there are multiple A ¹ 's, the multiple A ¹ 's may be the same or different. When there are multiple Q's, the multiple Q's may be the same or different.
r is an integer of 1 or more.
[2] L in the general formula (1) is a divalent aromatic ring group which may have a substituent, a divalent aliphatic ring group which may have a substituent, and carbon The composition for forming a thermally conductive material according to [1], which is a divalent organic group having at least one selected from the group consisting of alkylene groups which may have two or more branches.
[3] The heat according to [1] or [2], wherein L in the general formula (1) is a divalent organic group having a divalent aromatic ring group which may have a substituent. A composition for forming a conductive material.
[4] The composition for forming a heat conductive material according to any one of [1] to [3], wherein the compound represented by the general formula (1) has a Hansen solubility parameter value of ^0.5 or less at 28 MPa.
[5] The composition for forming a thermally conductive material according to any one of [1] to [4], wherein the compound represented by the general formula (1) has a Hansen solubility parameter value of ^0.5 or less at 26 MPa.
[6] The composition for forming a thermally conductive material according to any one of [1] to [5], further comprising a curing accelerator.
[7] The composition for forming a thermally conductive material according to any one of [1] to [6], wherein the inorganic particles are inorganic nitrides.
[8] The composition for forming a thermally conductive material according to any one of [1] to [7], wherein the inorganic particles are boron nitride.
[9] The composition of [1] to [8], wherein the content of the compound represented by the general formula (1) is 3 to 40% by mass with respect to the total solid content of the composition for forming a thermally conductive material. A composition for forming a thermally conductive material according to any one of the above.
[10] A thermally conductive sheet formed by curing the composition for forming a thermally conductive material according to any one of [1] to [9].
[11] The heat conductive sheet according to [10];
A thermally conductive multilayer sheet having an adhesive layer or a pressure-sensitive adhesive layer provided on one side or both sides of the thermally conductive sheet.
[12] a device;
A device with a heat conductive layer, comprising: a heat conductive layer including the heat conductive sheet of [10] or the heat conductive multilayer sheet of [11] disposed on the device.

ADVANTAGE OF THE INVENTION According to this invention, the composition for forming the thermally-conductive material which is excellent in thermal conductivity can be provided.
Moreover, according to the present invention, it is possible to provide a thermally conductive sheet, a thermally conductive multilayer sheet, and a device with a thermally conductive layer formed from the above composition.

Hereinafter, the composition for forming a thermally conductive material, the thermally conductive sheet, the thermally conductive multilayer 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, an epoxy group is a functional group also called an oxiranyl group. For example, two adjacent carbon atoms of a saturated hydrocarbon ring group are bonded by an oxo group (--O--) to form an oxirane ring. Epoxy groups also include groups such as Epoxy groups may or may not have substituents (such as methyl groups) where possible.

In the present specification, the acid anhydride group may be a monovalent group or a divalent group unless otherwise specified. When the acid anhydride group represents a monovalent group, substitution obtained by removing any hydrogen atom from acid anhydrides such as maleic anhydride, phthalic anhydride, pyromellitic anhydride, and trimellitic anhydride groups. Also, when the acid anhydride group represents a divalent group, it is intended to be a group represented by *--CO--O--CO--* (* represents a bonding position).

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 as long as the desired effect is not impaired.
In this specification, expressions such as "may be" and "may be" satisfy the conditions set as "may be" and "may be". It is intended that it may or may not be satisfied. For example, "optionally having a substituent" also includes "optionally having no substituent".
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, which can be selected from the following substituent group Y, for example.
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-diaryl carbamoyl group, N-alkyl-N-arylcarbamoyl group, alkylsulfinyl group, arylsulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfo group (—SO ₃ H) and its conjugate base group, alkoxysulfonyl group, aryloxysulfonyl group, sulfinamoyl group, N-alkylsulfinamoyl group, N,N-dialkylsulfinamoyl group, N-arylsulfinamoyl group, N,N-diarylsulfinamoyl group, N-alkyl-N-arylsulfina moyl group, sulfamoyl group, N-alkylsulfamoyl group, N,N-dialkylsulfamoyl group, N-arylsulfamoyl group, N,N-diarylsulfamoyl group, N-alkyl-N-arylsulfamoyl group famoyl 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)), monoalkylphosphonoxy groups (—OPO ₃ H(alkyl)) and their conjugate base groups, monoarylphosphorus a nooxy group (--OPO ₃ H(aryl)) and its conjugate base group, a cyano group, a nitro group, an aryl group, an alkenyl group, an alkynyl group and an alkyl group;
In addition, these substituents may or may not form a ring by bonding with each other or with the group substituting them, if possible.
Moreover, in this specification, each component may use the substance applicable to each component individually by 1 type, or may use 2 or more types together. Here, when two or more substances are used in combination for each component, the content of the component refers to the total content of the substances used in combination unless otherwise specified.

[Composition for Forming Thermal Conductive Material]
The composition for forming a thermally conductive material of the present invention (hereinafter also abbreviated as "the composition of the present invention") comprises inorganic particles and a compound represented by the general formula (1) described later (hereinafter also abbreviated as "specific compound" .) and including.

The composition for forming a thermally conductive material of the present invention having such a structure can form a thermally conductive material having excellent thermal conductivity.
Although this is not clear in detail, the present inventors presume as follows.
That is, since the specific compound is a compound having two or more triazine rings, it is considered to have a high affinity with the inorganic particles.
In addition, since the specific compound has at least two predetermined groups (specific functional groups), not only between the inorganic particles with high affinity, but also between the specific compounds, between the specific compounds and as desired Interactions may also occur with other components added (eg, phenolic compounds and/or epoxy compounds).
Therefore, a thermal conduction path is formed via the specific compound by the interaction via the specific functional group of the specific compound, so that the thermal conductivity of the thermally conductive material formed using the composition of the present invention is improved. The inventors speculate that

The components contained in the composition are described in detail below.

[Specific compound]
The composition for forming a thermally conductive material of the present invention contains a specific compound.
A specific compound is a compound represented by general formula (1).

In general formula (1), E ¹ to E ⁶ each independently represent a single bond, -NH- or -NR-.
R represents a substituent. Examples of substituents represented by R include linear or branched alkyl groups having 1 to 5 carbon atoms. When a plurality of -NR- are present among E ¹ to E ⁶ , the plurality of R's may be the same or different.
Among them, in the general formula (1), E ¹ to E ⁶ are each independently preferably -NH- or -NR-, and -NH- is more preferred.

In general formula (1), B ¹ , B ² , B ³ , and B ⁴ each represent a k+1-valent, l+1-valent, m+1-valent, and n+1-valent organic group, at least one of which represents a substituent It represents a k+1-valent, l+1-valent, m+1-valent, or n+1-valent aromatic ring group which may have.

The organic group represented by B ¹ to B ⁴ includes, for example, a group obtained by removing j hydrogen atoms from a hydrocarbon group having 1 to 20 carbon atoms and optionally having a heteroatom. Note that j means k+1, l+1, m+1, or n+1.
Here, the hydrocarbon group before removal of j hydrogen atoms is, for example, an aliphatic hydrocarbon group having 1 to 20 carbon atoms which may have a substituent, or an aliphatic hydrocarbon group which may have a substituent. Aliphatic cyclic groups having 3 to 20 carbon atoms and aromatic cyclic groups having 3 to 20 carbon atoms which may have a substituent are included.
Examples of aliphatic hydrocarbon groups having 1 to 20 carbon atoms include methane, ethane, propane, butane, pentane, hexane and heptane.
Examples of the aliphatic cyclic group having 3 to 20 carbon atoms include cyclohexane ring group, cycloheptane ring group, norbornane ring group and adamantane ring group.
Examples of aromatic ring groups having 3 to 20 carbon atoms include aromatic hydrocarbon groups having 6 to 20 carbon atoms and aromatic heterocyclic groups having 3 to 20 carbon atoms.
Examples of aromatic hydrocarbon groups having 6 to 20 carbon atoms include benzene ring, naphthalene ring, and anthracene ring. Examples of aromatic heterocyclic groups having 3 to 20 carbon atoms include furan ring and pyrrole ring. , thiophene ring, pyridine ring, thiazole ring, carbazole ring, indole ring, and benzothiazole ring.

Among these, the organic group represented by B ¹ to B ⁴ is an aromatic ring group optionally having a substituent from which j hydrogen atoms are removed, since the thermal conductivity of the thermal conductive material is more excellent. is preferably a group, more preferably a group obtained by removing j hydrogen atoms from a benzene ring.

In general formula (1), k, l, m and n each independently represent an integer of 0 or greater. However, the sum of k, l, m and n is 2 or more.
l, m and n are each independently preferably 0 to 5, more preferably 1 to 2.
Note that B ¹ does not have X ¹ when k is 0. When l is 0, B ² has no X ² . When m is 0, ^B3 has no ^X3 . When n is 0, B ⁴ has no X ⁴ .

When k is 2 or more (that is, when there are a plurality of X ¹ 's), the plurality (k) of X ^1's may be the same or different. When l is 2 or more (that is, when there are a plurality of X ² ), the plurality (l) of X ² may be the same or different. When m is 2 or more (that is, when there are a plurality of X ³ 's), the plurality (m) of X ^3's may be the same or different. When n is 2 or more (that is, when there are multiple X ⁴ 's), the multiple (n) X ^4's may be the same or different.

In general formula (1), the total number of k, l, m and n is 2 or more, preferably an integer of 2-12, more preferably an integer of 4-8.
In other words, the total number of each of X ¹ to X ⁴ , which may be plural, is 2 or more, preferably an integer of 2 to 12, more preferably an integer of 4 to 8.

For example, k is preferably 1 or more (more preferably 1 to 2), l is preferably 1 or more (more preferably 1 to 2), and m is 1 or more (more preferably 1 to 2). and n is preferably 1 or more (more preferably 1 to 2).
That is, B ¹ preferably has 1 or more (more preferably 1 to 2) X ¹ , B ² preferably has 1 or more (preferably 1 to 2) X 2, and ^{B 3} preferably has 1 or more (preferably 1 to 2) X ³ .

L represents a divalent organic group.
Examples of the organic group include an optionally substituted aromatic ring group, an optionally substituted aliphatic hydrocarbon group, an optionally substituted aliphatic ring group, - O-, -S-, -N(R ^N )- or -C(=O)-, or a group combining these.
^RN represents a substituent. Examples of substituents represented by R ^N include linear or branched alkyl groups having 1 to 5 carbon atoms.
Further, the aromatic ring group, the aliphatic hydrocarbon group, and the substituent which the aliphatic ring group may have include, for example, a linear or branched alkyl group having 1 to 5 carbon atoms. mentioned.

Examples of aromatic ring groups include aromatic hydrocarbon groups having 6 to 20 carbon atoms and aromatic heterocyclic groups having 3 to 20 carbon atoms.
Examples of aromatic hydrocarbon groups having 6 to 20 carbon atoms include monocyclic aromatic ring groups such as benzene ring; polycyclic aromatic ring groups such as naphthalene ring and anthracene ring; 3-20 aromatic heterocyclic groups include, for example, monocyclic aromatic ring groups such as furan ring, pyrrole ring, thiophene ring, pyridine ring and thiazole ring; benzothiazole ring, carbazole ring and indole ring Polycyclic aromatic ring groups such as;
In addition, examples of the aromatic ring group for L include groups obtained by removing two hydrogen atoms from the above examples.

Examples of the aliphatic hydrocarbon group include alkylene groups having 1 to 12 carbon atoms, and specific examples include methylene group, ethylene group, propylene group, butylene group, pentylene group, hexylene group, and methylhexylene group. , and a heptylene group.

Examples of aliphatic ring groups include cyclohexane ring groups, cycloheptane ring groups, norbornane ring groups, and adamantane ring groups.
In addition, the aliphatic ring group as L includes groups obtained by removing two hydrogen atoms from the above examples.

optionally substituted aromatic ring group, optionally substituted aliphatic hydrocarbon group, optionally substituted aliphatic ring group, or -O-, -S Groups in which -, -N(R ^N )- or -C(=O)- are combined include not only divalent linking groups consisting of a combination of two or more of these, but also groups of the same type (e.g., aromatic ring group) in combination of two or more via a single bond.

In the present invention, it is preferable that both terminals of L are carbon atoms, in order to improve the thermal conductivity of the thermally conductive material. The terminal carbon atom may be part of a ring structure.
Further, in the present invention, from the viewpoint that the thermal conductivity of the thermally conductive material is more excellent, L in the general formula (1) is a divalent aromatic ring group optionally having a substituent, a substituent A divalent organic group having at least one selected from the group consisting of an optionally divalent aliphatic cyclic group and an optionally branched alkylene group having 2 or more carbon atoms. A divalent organic group having a divalent aromatic ring group which may have a substituent is more preferable because of its superior thermal conductivity.

In general formula (1), r is an integer of 1 or more.
r is preferably an integer of 1-20, more preferably an integer of 1-10.

In general formula (1), X ¹ to X ⁴ each independently represent a group represented by general formula (2).

In the above general formula (2), * represents the bonding position with any one of B ¹ to B ⁴ .

In general formula (2) above, D ¹ represents a single bond or a divalent linking group.
Examples of the divalent linking group include -O-, -S-, -CO-, -NR ^N -, -SO ₂ -, an alkylene group, and a group consisting of a combination thereof. R ^N in -NR ^N - represents a hydrogen atom or a substituent. The alkylene group is preferably a linear or branched alkylene group having 1 to 8 carbon atoms.
Among them, D ¹ is preferably a "single bond" or a "group consisting of a combination selected from the group consisting of -O-, -CO- and an alkylene group", a single bond, * ^A -alkylene group -O- CO-* ^B , * ^A -CO-O-alkylene group-* ^B , * ^A -O-alkylene group-O-* ^B , * ^A -CO-O-alkylene group-O-CO-* ^B , * ^A -CO-O-alkylene group -O-* ^B or * ^A -O-alkylene group -O-CO-* ^B is more preferred.
* ^A is the point of attachment opposite to ^A1 and * ^B is the point of attachment to ^A1 .

In general formula (2) above, A ¹ represents an optionally substituted aromatic ring group or an optionally substituted aliphatic ring group.
In addition, A ¹ is bonded to D ¹ , Y ¹ and Q through an atom constituting the aromatic ring group or the aliphatic ring group.

The optionally substituted aromatic ring group, which is one aspect of ^A1 , may be a monocyclic aromatic ring group or a polycyclic aromatic ring group.
The monocyclic aromatic ring group preferably has 6 to 10 membered rings.
The number of rings constituting the polycyclic aromatic ring group is preferably 2 to 4, more preferably 2. The number of ring members constituting the polycyclic aromatic ring group is preferably 5 to 10 independently.
The aromatic ring group may be either an aromatic hydrocarbon ring group or an aromatic heterocyclic group.
The number of heteroatoms possessed by the aromatic heterocyclic group is preferably 1-5. Heteroatoms include, for example, nitrogen, sulfur, oxygen, selenium, tellurium, phosphorus, silicon, and boron atoms. Among them, a nitrogen atom, a sulfur atom, or an oxygen atom is preferable.
Examples of the aromatic ring group include benzene ring group, naphthalene ring group, anthracene ring group, benzothiazole ring group, carbazole ring group, and indole ring group.

An optionally substituted aliphatic cyclic group, which is one embodiment of A ¹ , may be monocyclic or polycyclic.
The monocyclic aliphatic ring group preferably has 6 to 10 membered rings.
The number of rings constituting the polycyclic aliphatic ring group is preferably 2 to 4, more preferably 2. The number of ring members constituting the polycyclic cycloalkane ring group is preferably 5 to 10 independently.
The number of carbon atoms as ring member atoms in the above aliphatic ring group is preferably 6 or more, more preferably 6 to 12. The number of carbon atoms that are ring-member atoms means the number of carbon atoms that are ring-member atoms constituting an aliphatic ring.
Examples of the aliphatic ring group include a cyclohexane ring group, a cycloheptane ring group, a norbornane ring group, and an adamantane ring group.

In the above general formula (2), Q and Y ¹ are each independently a hydroxyl group (-OH), a monovalent group having an epoxy group, an amino group, a thiol group (-SH), a carboxylic acid group (-COOH). , an isocyanate group (--NCO), and a specific functional group selected from the group consisting of a monovalent group having an oxetanyl group.
That is, the group represented by general formula (2) is a group having at least one specific functional group. Here, the group represented by the general formula (2) "is a group having a specific functional group", even if the group represented by the general formula (2) is a group containing a specific functional group as a part Well, the group represented by general formula (2) may be the specific functional group itself.

The monovalent group having an epoxy group as the specific functional group is preferably, for example, a group represented by " ^--Leo --epoxy group". L ^eo is a single bond or a divalent linking group, an oxygen atom, an alkylene group (preferably a linear or branched alkylene group having 1 to 6 carbon atoms), or a group consisting of a combination thereof preferable.
Among them, the monovalent group having an epoxy group is preferably "--O-alkylene group-epoxy group".
As a substituent which the epoxy group may have, a linear or branched alkyl group having 1 to 6 carbon atoms is preferable.

The amino group as the specific functional group is not particularly limited, and may be primary, secondary or tertiary. Examples thereof include -N(R ^E ) ₂ (each R ^E is independently a hydrogen atom or an alkyl group (which may be linear or branched)). The number of carbon atoms in the alkyl group is preferably 1-10, more preferably 1-6, and even more preferably 1-3. In addition, the alkyl group may further have a substituent.

The monovalent group having an oxetanyl group as the specific functional group is preferably, for example, a group represented by " ^--Leo -oxetanyl group". L ^eo is a single bond or a divalent linking group, an oxygen atom, an alkylene group (preferably a linear or branched alkylene group having 1 to 6 carbon atoms), or a group consisting of a combination thereof preferable.
Among them, the monovalent group having an oxetanyl group is preferably "--O-alkylene group-oxetanyl group".
As the substituent which the oxetanyl group may have, a linear or branched alkyl group having 1 to 6 carbon atoms is preferable.

Among them, the specific functional group is preferably a hydroxyl group or a monovalent group having an epoxy group.

In the general formula (2), p represents an integer of 0 or more.
Among them, p is preferably 0 to 5, more preferably 0 to 1.
When p is 0, Y ¹ directly bonds to any of B ¹ -B ⁴ . That is, X ¹ to X ⁴ may be the specific functional groups themselves.

In the above general formula (2), q represents an integer of 0-2.
Among them, q is preferably 0 to 1.

When a plurality of groups represented by general formula (2) are present in the specific compound, the groups represented by general formula (2) may be the same or different.
For example, in general formula (2), when there are multiple D ¹ 's, the multiple D ¹ 's may be the same or different. When there are multiple A ¹ 's, the multiple A ¹ 's may be the same or different. When there are multiple Q's, the multiple Q's may be the same or different.

The specific compound may have one type of group represented by general formula (2) alone, or may have two or more types.
Among them, the specific compound is preferably "a compound having only a hydroxyl group as a specific functional group" or "a compound having only a monovalent group having an epoxy group as a specific functional group".

In the present invention, the Hansen solubility parameter (hereinafter also abbreviated as "HSP") of the compound represented by the general formula (1) is preferably 28 MPa ^0.5 or less for the reason that water resistance is improved. , 26 MPa ^0.5 or less. The lower limit of the HSP value of the specific compound is not limited, and is preferably 10 MPa ^0.5 or more, for example.
As the HSP value of a specific compound, a value calculated from the following formula is adopted.
HSP value = (HSP _d ² +HSP _p ² +HSP _h ² ) ^0.5
HSP _d , HSP _p , and HSP _h represent the dispersion term, polar term, and hydrogen bond term, respectively, of the HSP value (each unit is MPa ^0.5 ).
HSP _d , HSP _p , HSP _h are HSPiP (Hansen Solubility Parameter

In the composition for forming a thermally conductive material of the present invention, the content of the specific compound is preferably 3 to 40% by mass with respect to the total solid content of the composition from the viewpoint that the thermal conductivity of the thermally conductive material is more excellent. ~25% by mass is more preferred.

In addition, the content of the specific compound in the composition of the present invention is preferably 4 to 60% by mass, more preferably 10 to 35% by mass, and even more preferably 12 to 30% by mass, relative to the mass of the inorganic particles.
A specific compound may be used individually by 1 type, and may use 2 or more types.

[Phenolic compound]
Compositions of the present invention may further comprise a phenolic compound.
In addition, a phenol compound is a compound other than a specific compound. For example, even if a specific compound has a phenolic hydroxyl group, the specific compound does not correspond to a phenol compound.
The phenolic compound is selected from the group consisting of compounds represented by the general formula (P1) or compounds represented by the general formula (P2), since the resulting thermally conductive material has better thermal conductivity. One or more is preferred.

<Compound Represented by General Formula (P1)>
General formula (P1) is shown below.

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), na and nc each independently represent an integer of 1 or more.
na and nc are each independently preferably 1-4.

In general formula (P1), R ¹ and R ⁶ each independently represent a hydrogen atom, 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 and R ⁶ are each independently preferably a hydrogen atom or a halogen atom, more preferably a hydrogen atom or a chlorine atom, and still more preferably a hydrogen atom.

In general formula (P1), ^R7 represents a hydrogen atom or a hydroxyl group.
When multiple R ⁷ are present, the multiple R ⁷ may be the same or different.
When a plurality of R ⁷ are present, it is also preferred that at least one R ⁷ among the plurality of R ⁷ present represents a hydroxyl group.

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 of the alkoxy group and the alkyl group portion of 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 -CH ₂ -, -CH(OH)-, -CO-, or
-CH(Ph)- is preferred.
Ph above represents a phenyl group which may have a substituent.
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.

In general formula (P1), Ar ¹ and Ar ² each independently represent a benzene ring group or a naphthalene ring group.
Ar ¹ and Ar ² are each independently preferably a benzene ring group.

In general formula (P1), ^Qa represents a hydrogen atom, 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 of the alkoxy group and the alkyl group portion of the alkoxycarbonyl group are the same as the alkyl group.
The phenyl group may or may not have a substituent.
Q ^a is preferably bonded at the para-position with respect to the hydroxyl group which the benzene ring group to which Q ^a is bonded may have.
^Qa is preferably a hydrogen atom or an alkyl group. The above alkyl group is preferably a methyl group.

In general formula (P1), when a plurality of R ⁷ , L ^x2 and/or Q ^a are present, the plurality of R ⁷ , L ^x2 and/or Q ^a may be the same or different. good too.

<Compound Represented by Formula (P2)>
General formula (P2) is shown below.

In general formula (P2), m2 represents an integer of 0 or more.
m2 is preferably 0 to 10, more preferably 0 to 4.

In general formula (P2), nx represents an integer of 0-4.
nx is preferably 1 to 2, more preferably 2.

In general formula (P2), ny represents an integer of 0-2.
When there are a plurality of ny, the plurality of ny may be the same or different.
It is preferable that at least one ny represents 1 among ny which may exist in plurality. For example, when m2 represents 1, it is preferable that one ny present represents 1. When m2 represents 4, at least one ny among four nys preferably represents 1, and two nys more preferably represent 1.

In general formula (P2), nz represents an integer of 0-2.
nz is preferably 1.

In general formula (P2), the total number of nx, ny which may be present in plurality, and nz is preferably 2 or more, more preferably 2-10.

In general formula (P2), R ¹ and R ⁶ each independently represent a hydrogen atom, a halogen atom, a carboxylic acid group, a boronic acid group, an aldehyde group, an alkyl group, an alkoxy group, or an alkoxycarbonyl group.
R ¹ and R ⁶ in general formula (P2) are the same as R ¹ and R ⁶ in general formula (1), respectively.
When there are multiple R ¹ 's, the multiple R ¹ 's may be the same or different. When multiple R ⁶ are present, the multiple R ⁶ may be the same or different.

In general formula (P2), ^Qb represents a hydrogen atom, 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 of the alkoxy group and the alkyl group portion of the alkoxycarbonyl group are the same as the alkyl group.
The phenyl group may or may not have a substituent.
Q ^b is preferably a hydrogen atom.
When there are multiple Q ^bs , the multiple Q ^bs may be the same or different.

Specific examples of the compound represented by formula (P2) include benzenetriol (preferably 1,3,5-benzenetriol).

Other phenolic compounds include, for example, biphenylaralkyl-type phenolic resins, phenolic novolac resins, cresol novolak resins, aromatic hydrocarbon-formaldehyde resin-modified phenolic resins, dicyclopentadiene phenol addition-type resins, phenolic aralkyl resins, and polyhydric hydroxy compounds. polyhydric phenol novolac resins synthesized from formaldehyde, naphthol aralkyl resins, trimethylolmethane resins, tetraphenylolethane resins, naphthol novolac resins, naphthol phenol co-condensed novolac resins, naphthol cresol co-condensed novolak resins, biphenyl-modified phenol resins, Biphenyl-modified naphthol resins, aminotriazine-modified phenol resins, and alkoxy group-containing aromatic ring-modified novolac resins are preferred.

The lower limit of the hydroxyl group content of the phenol compound is preferably 3.0 mmol/g or more, more preferably 8.0 mmol/g or more, still more preferably 11.0 mmol/g or more, and particularly preferably 12.0 mmol/g or more. 13.0 mmol/g or more is most preferred. The upper limit is preferably 25.0 mmol/g or less, more preferably 23.0 mmol/g or less.
In addition, the said hydroxyl group content intends the number of the hydroxyl groups (preferably phenolic hydroxyl groups) which 1g of phenol compounds have.
In addition to the hydroxyl group, the phenol compound may or may not have an active hydrogen-containing group (such as a carboxylic acid group) capable of polymerizing with the epoxy compound. The lower limit of the content of active hydrogen in the phenol compound (total content of hydrogen atoms in hydroxyl groups, carboxylic acid groups, etc.) is preferably 8.0 mmol/g or more, more preferably 10.5 mmol/g or more, and 11.0 mmol. /g or more is more preferable, 12.0 mmol/g or more is particularly preferable, and 13.0 mmol/g or more is most preferable. The upper limit is preferably 25.0 mmol/g or less, more preferably 23.0 mmol/g or less.

The upper limit of the molecular weight of the phenol compound is preferably 600 or less, more preferably 500 or less, even more preferably 450 or less, and particularly preferably 400 or less. 110 or more are preferable and, as for a lower limit, 300 or more are more preferable.

A phenol compound may be used individually by 1 type, and may use 2 or more types.
When the composition of the present invention contains a phenolic compound, the content of the phenolic compound is preferably 1.0 to 25.0% by mass, and 3.0 to 20.0% by mass, based on the total solid content of the composition. is more preferred.
The composition of the present invention may contain, as a compound other than the phenolic compound and the specific compound, a compound having a group capable of reacting with the epoxy compound described later (also referred to as "another active hydrogen-containing compound").
When the composition of the present invention contains a phenolic compound and also contains other active hydrogen-containing compounds, the mass of the content of the other active hydrogen-containing compounds with respect to the content of the phenolic compound in the composition of the present invention The ratio (content of other active hydrogen-containing compound/content of phenolic compound) is preferably 0 to 1, more preferably 0 to 0.1, and even more preferably 0 to 0.05.

[Epoxy compound]
The composition of the invention may further contain an epoxy compound.
In addition, an epoxy compound is a compound other than a specific compound. For example, even if the specific compound has an epoxy group, the specific compound is not an epoxy compound.
An epoxy compound is a compound having at least one epoxy group (oxiranyl group) in one molecule. Epoxy groups may be substituted or unsubstituted where possible.
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, and even more preferably 250 to 400.

The lower limit of the epoxy group content of the epoxy compound is preferably 2.0 mmol/g or more, more preferably 4.0 mmol/g or more, and even more preferably 5.0 mmol/g or more. The upper limit is preferably 20.0 mmol/g or less, more preferably 15.0 mmol/g or less.
In addition, the said epoxy group content intends the number of epoxy groups which 1g of epoxy compounds have.
The epoxy compound is preferably liquid at normal temperature (23° C.).

The epoxy compound may or may not exhibit liquid crystallinity.
That is, the epoxy compound may be a liquid crystal compound. In other words, a liquid crystal compound having an epoxy group can also be used as the epoxy compound.
The epoxy compound (which may be a liquid crystalline epoxy compound) includes, for example, a compound at least partially containing a rod-like structure (rod-like compound), and a compound discotic compound at least partially including a discotic structure. be done.
Among them, a rod-shaped compound is preferable because the thermal conductivity of the obtained thermally conductive material is more excellent.
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. The divalent linking group represented by L ¹¹⁵ includes specific examples of the divalent linking groups represented by L ¹¹¹ to L ¹¹⁴ described above, such as -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 above skeletons, a biphenyl skeleton is preferable because the obtained thermally conductive sheet 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 rodlike compound preferably has a biphenyl skeleton.
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 3-substituted benzene structures described in JP-A-2007-2220 and JP-A-2010-244038.

The discotic compound preferably has 3 or more epoxy groups. A cured product of an epoxy compound 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 compounds having at least one (preferably three or more) epoxy groups in the compounds described in Japanese Patent No. 4,592,225.
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.

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

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.
When the composition of the present invention contains an epoxy compound, the content of the epoxy compound is preferably 1.0 to 25.0% by mass, preferably 3.0 to 20.0% by mass, based on the total solid content of the composition. is more preferred.

The composition of the present invention preferably contains at least one of the above phenolic compounds and epoxy compounds.
In this case, the composition, as described above, of the phenol compound and the epoxy compound, may contain only the phenol compound (may not substantially contain the epoxy compound) or may contain only the epoxy compound ( may be substantially free of phenolic compounds) or may contain both of each.
When the composition of the present invention contains an epoxy compound and a phenol compound, respectively, the ratio of the content of the epoxy compound to the content of the phenol compound in the composition is the ratio of the epoxy group of the epoxy compound to the hydroxyl group of the phenol compound. The equivalent ratio (number of epoxy groups/number of hydroxyl groups) is preferably 30/70 to 70/30, more preferably 35/65 to 65/35.
In addition, when the composition of the present invention contains an epoxy compound and a phenol compound, respectively, the ratio of the content of the epoxy compound to the content of the phenol compound in the composition is determined by the activity of the epoxy group of the epoxy compound and the activity of the phenol compound. The equivalent ratio (number of epoxy groups/number of active hydrogens) to hydrogen (such as hydrogen atoms in hydroxyl groups) is preferably 30/70 to 70/30, more preferably 35/65 to 65/35. preferable.

In addition, the number of epoxy groups contained in the epoxy compound and the number of epoxy groups contained in the specific compound with respect to the total number of hydroxyl groups contained in the phenol compound and the number of hydroxyl groups contained in the specific compound in the composition The ratio of the total number of epoxy groups (number of epoxy groups/number of hydroxyl groups) is preferably 30/70 to 70/30, more preferably 40/60 to 60/40, and 42/58. An amount of ~58/42 is more preferred.
In this case, the composition may contain only one of the epoxy compound and the phenol compound, may contain both, or may contain neither.

Further, when the composition contains a specific compound having an epoxy group, a specific compound having an active hydrogen, and/or other active hydrogen-containing compounds, the total content of the epoxy compound and the specific compound having an epoxy group and , the ratio of the total content of phenol compounds, specific compounds having active hydrogen, and other active hydrogen-containing compounds is the equivalent ratio of epoxy groups and active hydrogen (hydrogen atoms in hydroxyl groups, etc.) in the system (epoxy group / number of active hydrogen) is preferably 30/70 to 70/30, more preferably 40/60 to 60/40, and even more preferably 42/58 to 58/42. .

When the composition of the present invention contains both an epoxy compound and a phenolic compound, the total content of the phenolic compound and the epoxy compound in the composition is preferably 5 to 90% by mass based on the total mass of the solid content. , more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass.

[Inorganic particles]
The composition for forming a thermally conductive material of the present invention contains inorganic particles.
Examples of inorganic particles include inorganic oxides such as iron oxide, silica (SiO ₂ ), alumina (Al ₂ O ₃ ), TiO ₂ , BaTiO ₃ and ZrO ₂ ; inorganic nitrides such as aluminum nitride and silicon nitride; Poorly soluble ionic crystals such as calcium chloride, barium fluoride, and barium sulfate; clays such as montmorillonite; and fine particles.

In the present invention, the inorganic particles are preferably inorganic nitrides or inorganic oxides, more preferably inorganic nitrides, because the resulting thermally conductive material has better thermal conductivity.
Specific examples of inorganic nitrides include boron nitride (BN), carbon nitride (C ₃ N ₄ ), silicon nitride (Si ₃ N ₄ ), gallium nitride (GaN), indium nitride (InN), nitride Aluminum (AlN), chromium nitride ( _Cr2N ), copper nitride ( _Cu3N ), iron nitride ( _Fe4N or _Fe3N ), lanthanum nitride (LaN), lithium nitride ( _Li3N ), magnesium nitride ( Mg ₃ N ₂ ), molybdenum nitride (Mo ₂ N), niobium nitride (NbN), tantalum nitride (TaN), titanium nitride (TiN), tungsten nitride (W ₂ N, WN ₂ or WN), yttrium nitride ( YN), and zirconium nitride (ZrN).
The above inorganic nitrides may be used singly or in combination.
The inorganic nitride preferably contains at least one selected from the group consisting of boron atoms, aluminum atoms, and silicon atoms in that the resulting thermally conductive material has better thermal conductivity. More specifically, the inorganic nitride is preferably boron nitride, aluminum nitride, or silicon nitride, more preferably boron nitride or aluminum nitride, and even more preferably boron nitride.

The shape of the inorganic particles is not particularly limited, and examples thereof include rice grain-like, spherical, cubic, spindle-like, scale-like, aggregated, and irregular shapes. Among them, the shape of the particles is preferably scaly or agglomerated.
Moreover, one type of inorganic particles having different shapes may be used alone, or two or more types may be used.

Although the size of the inorganic particles is not particularly limited, the average particle size of the inorganic particles is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 200 μm or less, in terms of better dispersibility of the inorganic particles. Although the lower limit is not particularly limited, it is preferably 10 nm or more, more preferably 100 nm or more, in terms of handleability.
As a method for measuring the average particle size, an electron microscope is used to randomly select 100 inorganic particles, measure the particle size (major axis) of each inorganic particle, and obtain by arithmetically averaging them. . In addition, when using a commercial item, you may use a catalog value.

The content of the inorganic particles in the composition of the present invention is preferably 60 to 90% by mass, more preferably 70 to 85% by mass, and even more preferably 75 to 80% by mass, based on the total solid content of the composition.
As used herein, the solid content of the composition refers to all components other than the solvent when the composition contains a solvent, and even liquid components other than the solvent are considered solid. .

The average particle size of the inorganic particles contained in the composition is preferably larger than 3 μm, more preferably 4 to 50 μm, in order to improve the thermal conductivity of the thermally conductive material.

In addition, it is also preferable that the inorganic substances have different average particle diameters. It is also preferred to include
The average particle size of the inorganic substance X is preferably 20-300 μm, more preferably 30-200 μm. The average particle size of the inorganic substance Y is preferably 10 nm or more and less than 20 μm, more preferably 100 nm or more and 15 μm or less.
The inorganic substance X is preferably an inorganic nitride or an inorganic oxide, more preferably an inorganic nitride, and still more preferably boron nitride.
The inorganic substance Y is preferably inorganic nitride or inorganic oxide, more preferably boron nitride or aluminum oxide, and still more preferably boron nitride.
Each of the inorganic substance X and the inorganic substance Y may be used alone or in combination of two or more.
In the inorganic substance, the mass ratio of the content of inorganic substance X to the content of inorganic substance Y (content of inorganic substance X/content of inorganic substance Y) is preferably 50/50 to 99/1, and 75/25 to 97/3. is more preferred.
Further, the content of boron nitride in the inorganic particles is preferably 55% or more, more preferably 75% or more, because the thermal conductivity of the thermally conductive material formed from the composition is more excellent.

[Curing accelerator]
The composition of the present invention may further contain a curing accelerator in order to improve the thermal conductivity of the thermally conductive material.
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), and 1-cyanoethyl-2-phenylimidazole (trade name; 2PZ-CN) and other imidazole curing accelerators etc. (both manufactured by Shikoku Kasei Co., Ltd.).
A single curing accelerator may be used alone, or two or more curing accelerators may be used.
When the composition contains a curing accelerator, the content of the curing accelerator is preferably 0.01 to 10% by mass, and 0.1 to 5% by mass, based on the total content of the epoxy compound and the specific compound having an epoxy group. is more preferred.

[Dispersant]
The composition of the invention may further contain a dispersant.
When the composition contains a dispersant, the dispersibility of the inorganic material in the composition is improved, and superior thermal conductivity and adhesion can be achieved.

The dispersant can be appropriately selected from commonly used dispersants. For example, DISPERBYK-106 (manufactured by BYK-Chemie GmbH), DISPERBYK-111 (manufactured by BYK-Chemie GmbH), ED-113 (manufactured by Kusumoto Kasei Co., Ltd.), Ajisper PN-411 (manufactured by Ajinomoto Fine Techno), and REB122- 4 (manufactured by Hitachi Chemical Co., Ltd.) and the like.
A dispersant may be used individually by 1 type, and may use 2 or more types.
When the composition of the present invention contains a dispersant, the content of the dispersant is preferably 0.01 to 10% by mass, more preferably 0.1 to 5% by mass, based on the content of the inorganic substance.

〔solvent〕
The composition of the invention 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 of the present invention contains a solvent, the content of the solvent is preferably an amount that makes the solid content concentration of the composition 20 to 90% by mass, more preferably an amount that makes 30 to 85% by mass. An amount of 85% by mass is more preferred.

[Method for producing composition]
The method for producing the composition of the present invention 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 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. and a homogenizer. 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.

[Method for producing thermally conductive material]
A thermally conductive material is obtained by curing the composition of the present invention.
The method for curing the composition of the present invention is not particularly limited, but thermosetting reaction is preferred.
The heating temperature during the thermosetting reaction is not particularly limited. For example, the temperature may be appropriately selected within the range of 50 to 250°C. Moreover, when performing a thermosetting reaction, heat treatment at different temperatures may be performed a plurality of times.
The curing treatment is preferably carried out on the composition in the form of a film or sheet. Specifically, for example, the composition may be applied to form a film, followed by a curing reaction.
When the curing treatment is performed, it is preferable to apply the composition on the substrate to form a coating film and then cure the composition. In this case, the coating film formed on the substrate may be brought into contact with another substrate before the curing treatment. The cured product (thermal conductive material) obtained after curing may or may not be separated from one or both of the substrates.
In addition, when performing the curing treatment, the composition may be applied on separate substrates to form coating films, respectively, and the curing treatment may be performed in a state in which the obtained coating films are brought into contact with each other. The cured product (thermal conductive material) obtained after curing may or may not be separated from one or both of the substrates.

The curing treatment may be terminated when the composition is in a semi-cured state. Further, after the composition is in a semi-cured state, a curing treatment may be further performed to complete curing.
Curing treatment for making the composition semi-cured (hereinafter also abbreviated as “semi-curing treatment”) and curing treatment for complete curing (hereinafter also abbreviated as “main curing treatment”), It may be carried out in separate steps.

For example, in the semi-curing treatment, after the composition is applied on the substrate to form a coating film, the coating film on the substrate is heated as it is without pressure to form a semi-cured thermally conductive material (hereinafter referred to as Also abbreviated as a “semi-cured film”), or by heating the coating film on the base material while press working in combination, to form a semi-cured film. When press working is performed, the press working may be performed before or after the heating or the like, or may be performed during the heating. If pressing is performed in the semi-curing treatment, it may be easier to adjust the film thickness of the resulting semi-cured film and/or reduce the amount of voids in the semi-cured film.
In the semi-curing treatment, the semi-curing treatment may be performed in a state in which the coating films formed on separate substrates are laminated with each other, or the semi-curing treatment may be performed without laminating the coating films. The semi-curing treatment may be performed while the coating film formed from the composition is in contact with a material other than the coating film.

The obtained semi-cured film may be used as a heat conductive material as it is, or may be used as a completely cured heat conductive material after being further subjected to a main curing treatment.
In the main curing treatment, the semi-cured film may be heated as it is without pressure, or may be heated after or while being pressed. At this time, in the main curing treatment, the main curing treatment may be performed in a state in which separate semi-cured films are laminated, or the main curing treatment may be performed without laminating the semi-cured films.
Further, the main curing treatment may be performed while the semi-cured film is placed in contact with the device or the like to be used. It is also preferred that the device and the thermally conductive material of the present invention adhere to each other through the main curing treatment.

There is no limitation on the press used for the pressing that may be performed during the hardening treatment in the semi-hardening treatment and/or the main hardening treatment, and for example, a flat press or a roll press may be used. .
When using a roll press, for example, a substrate with a coating film obtained by forming a coating film on the substrate is sandwiched between a pair of rolls facing each other, and the pair of rolls is sandwiched. It is preferable to apply pressure in the film thickness direction of the substrate with the coating film while rotating to pass the substrate with the coating film. The base material with the coating film may have the base material on only one side of the coating film, or may have the base material on both sides of the coating film. The coated substrate may be passed through the roll press only once or may be passed multiple times.
At the time of hardening treatment such as the semi-hardening treatment and/or the main hardening treatment, either one or both of flat press treatment and roll press treatment may be performed.

For the preparation of thermally conductive materials including curing reactions, reference can be made to "Highly Thermally Conductive Composite Materials" (by Yoshitaka Takezawa, published by CMC Publishing).

There are no particular restrictions on the shape of the heat-conducting material, and it 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.
That is, the thermally conductive material obtained using the composition of the present invention is also preferably a thermally conductive sheet (hereinafter also abbreviated as "the thermally conductive sheet of the present invention").
Also, the thermal conductivity of the thermally conductive material obtained using the composition of the present invention is preferably isotropic rather than anisotropic.

Preferably, the thermally conductive material is insulating (electrically insulating). In other words, the compositions of the present invention are preferably thermally conductive insulating compositions.
For example, the volume resistivity of the heat conductive material at 23° C. and 65% relative humidity is preferably 10 ¹⁰ Ω·cm or more, more preferably 10 ¹² Ω·cm or more, and even more preferably 10 ¹⁴ Ω·cm or more. Although the upper limit is not particularly limited, it is usually 10 ¹⁸ Ω·cm or less.

[Thermal conductive sheet]
The thermally conductive material obtained using the composition of the present invention may be used in combination with members other than members formed from the composition of the present invention.
For example, a sheet-like heat-conducting material (heat-conducting sheet) may be combined with a sheet-like support other than the layer formed from the composition of the present invention.
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 film thickness of the sheet-like thermally conductive material (thermally conductive sheet) is preferably 100 to 300 μm, more preferably 150 to 250 μm.

Furthermore, it is possible to form a thermally conductive multilayer sheet (hereinafter also abbreviated as "the thermally conductive multilayer sheet of the present invention") in which an adhesive layer or a pressure-sensitive adhesive layer is arranged on one or both sides of the thermally conductive sheet of the present invention. can.
By bonding the thermally conductive material to an object such as a device to which heat is to be transferred through such an adhesive layer and/or adhesive layer, the thermally conductive material and the object can be more strongly bonded. can be realized.
For example, as the thermally conductive multilayer sheet of the present invention, a thermally conductive multilayer sheet having the thermally conductive sheet of the present invention and an adhesive layer or pressure-sensitive adhesive layer provided on one or both sides of the thermally conductive sheet. may be made.
One or both of an adhesive layer and a pressure-sensitive adhesive layer may be provided on one side or both sides of the heat conductive sheet. An adhesive layer may be provided on one surface of the heat conductive sheet, and an adhesive layer may be provided on the other surface. In addition, an adhesive layer and/or a pressure-sensitive adhesive layer may be partially provided on one side or both sides of the heat conductive sheet, or may be provided entirely.
As described above, in the present invention, the thermally conductive material such as the thermally conductive sheet may be in a semi-cured state (semi-cured film), and the thermally conductive sheet in the thermally conductive multilayer sheet may be in a semi-cured state. . The adhesive layer in the thermally conductive multilayer sheet may be cured, semi-cured, or uncured.

<Adhesive layer>
The adhesive layer preferably contains at least one adhesive compound (resin and/or low-molecular-weight substance, etc.).
The adhesive layer may further contain other components such as fillers as necessary.

As the adhesive compound, a compound having insulating properties, adhesive properties, and/or flexibility at the time of adhesion is preferable.
Among them, from the viewpoint of adhesiveness and insulation, it is preferable to include at least one selected from the group consisting of polyimide resins, modified polyimide resins, polyamideimide resins, modified polyamideimide resins, and epoxy compounds.
The epoxy compound may be an epoxy resin containing an acrylic modified rubber.

Examples of the polyimide resin and modified polyimide resin include, for example, Upicoat FS-100L (manufactured by Ube Industries, Ltd.), Semicofine SP-300, SP-400, SP-800 (manufactured by Toray Industries, Inc.), and U-imide series ( manufactured by Unitika Ltd.).

Examples of the polyamideimide resin and modified polyamideimide resin include KS series (manufactured by Hitachi Chemical Co., Ltd.), Vylomax series (manufactured by Toyobo Co., Ltd.), and Torlon (manufactured by Solvay Advanced Polymers). .
Among them, from the viewpoint of high heat resistance and high adhesiveness, it is preferable to use a modified polyamideimide resin represented by the KS series (manufactured by Hitachi Chemical Co., Ltd.).

The polyimide resin, polyamideimide resin, and modified polyamideimide resin used in the adhesive layer may be used singly or in combination of two or more.
These resins are usually in the form of a varnish in which the resin is dissolved in a solvent, and can be used as an adhesive layer by coating directly on a support such as a PET film and drying the solvent to form a film.

Also, an epoxy compound may be used as the adhesive compound. Specifically, for example, an epoxy composition containing an epoxy compound, its curing agent, and a curing agent accelerator may be used as the adhesive layer. It is also preferable to add glycidyl acrylate to the epoxy composition.
For details of the epoxy composition, it is also possible to refer to, for example, JP-A-2002-134531, JP-A-2002-226796, and JP-A-2003-221573.

The epoxy compound used for the adhesive layer is not particularly limited as long as it cures and exhibits an adhesive action. For example, if a bisphenol A type or bisphenol F type liquid epoxy compound having a molecular weight of 500 or less is used, the fluidity during lamination can be improved. A polyfunctional epoxy compound may be added for the purpose of increasing the Tg (glass transition temperature). Examples of the polyfunctional epoxy compound include phenol novolak type epoxy compounds and cresol novolak type epoxy compounds.
As the epoxy compound used in the adhesive layer, the epoxy compounds described as the epoxy compounds that can be used in the composition of the present invention may be used.

Curing agents for epoxy compounds include, for example, polyamides, polyamines, acid anhydrides, polysulfides, boron trifluoride, or phenolic compounds (phenolic novolak resins, bisphenols, which are compounds having two or more phenolic hydroxyl groups per molecule. A, bisphenol F, or bisphenol S). It is also preferable to use a phenol novolak resin, a bisphenol novolak resin, or a cresol novolak resin, which is a phenol compound, from the viewpoint of excellent electrolytic corrosion resistance when moisture is absorbed.
Moreover, as the curing agent, the phenol compound described as the phenol compound that can be used in the composition of the present invention may be used.

When using a curing agent, it is preferable to use a curing accelerator together with the curing agent. It is also preferable to use triphenylphosphine or imidazole as the curing accelerator. Imidazoles include, for example, 2-methylimidazole, 2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, and 1-cyanoethyl-2-phenylimidazolium trimellitate. Imidazoles are commercially available, for example, from Shikoku Kasei Co., Ltd. under the trade names of 2E4MZ, 2PZ-CN, and 2PZ-CNS.

The epoxy compound used for the adhesive layer is preferably used in combination with a high molecular weight resin compatible with the epoxy compound.
High-molecular-weight resins compatible with epoxy compounds include, for example, high-molecular-weight epoxy compounds, highly polar functional group-containing rubbers, and highly polar functional group-containing reactive rubbers.
Examples of the highly polar functional group-containing reactive rubber include acrylic modified rubber obtained by adding a highly polar functional group such as a carboxyl group to an acrylic rubber.

Here, compatibility with an epoxy compound refers to the property of forming a homogeneous mixture without separating from the epoxy compound into two or more phases after curing.
The weight average molecular weight of the high molecular weight resin is not particularly limited. From the viewpoint of reducing the tackiness of the adhesive in the B stage and improving the flexibility during curing, the weight average molecular weight is preferably 30,000 or more.

High-molecular-weight epoxy compounds include high-molecular-weight epoxy compounds having a molecular weight of 30,000 to 80,000, and ultra-high-molecular-weight epoxy compounds having a molecular weight exceeding 80,000 (JP-B-7-59617, JP-B-7-59618, JP-B-7-59618, No. 7-59619, Japanese Patent Publication No. 7-59620, Japanese Patent Publication No. 7-64911, and Japanese Patent Publication No. 7-68327), all of which are manufactured by Hitachi Chemical Co., Ltd. As a highly polar functional group-containing reactive rubber, a carboxyl group-containing acrylic rubber is sold by Nagase ChemteX Corporation, for example, HTR-860P (trade name).

When a high molecular weight resin that is compatible with the epoxy compound and has a weight average molecular weight of 30,000 or more is used, the amount added is 10 parts by mass or more when the resin constituting the adhesive layer is 100 parts by mass. preferably 40 parts by weight or less.
When the amount is 10 parts by mass or more, it is easy to improve the flexibility, improve the tackiness, and/or suppress cracks of the phase containing the epoxy compound as the main component (hereinafter referred to as the epoxy compound phase), and the insulation is improved. difficult to decrease. When it is 40 parts by weight or less, the Tg of the epoxy compound phase can be improved.

The weight-average molecular weight of the high molecular weight epoxy compound is preferably 20,000 or more and 500,000 or less. Within this range, strength and/or flexibility in a sheet state and/or film state are improved, and tackiness is easily suppressed.

The polyamideimide resin, modified polyamideimide resin, and epoxy compound that are preferably used for the adhesive layer may be used alone or in combination of two or more.
These compounds may also be a varnish mixture in which the compounds are dissolved in a solvent. By directly coating such a mixture on a support such as a PET film and drying the solvent, the compound can be formed into a film and used as an adhesive layer.

(Silane coupling agent)
The adhesive layer may contain a silane coupling agent in order to improve interfacial bonding between different materials.
Examples of the silane coupling agent include γ-glycidoxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-ureidopropyltriethoxysilane, and N-β- Aminoethyl-γ-aminopropyltrimethoxysilane can be mentioned.
Among them, γ-mercaptopropyltrimethoxysilane or γ-aminopropyltriethoxysilane is preferable from the viewpoint of adhesive strength.
When the adhesive layer contains a silane coupling agent, the amount to be added is 0.1 to 10 parts by mass with respect to 100 parts by mass of the adhesive compound, from the viewpoint of the effect of addition and/or the effect on heat resistance. part is preferred.

(filler)
The adhesive layer may contain a filler (preferably an inorganic filler).
Including a filler in the adhesive layer improves the handleability and thermal conductivity of the adhesive layer. It is also possible to impart flame retardancy, adjust melt viscosity, impart thixotropic properties, and/or improve surface hardness.

When the adhesive layer contains a filler, its content is not particularly limited. Above all, the content is preferably 20 to 50 parts by volume with respect to 100 parts by volume of the adhesive compound contained in the adhesive layer.
From the viewpoint of blending effects, the content is more preferably 30 parts by volume or more. In addition, from the viewpoint of optimizing the storage elastic modulus of the adhesive, improving the adhesiveness, and/or suppressing voids, etc., and suppressing the deterioration of the insulation properties, etc., the content may be 50 parts by volume or less. preferable.

Examples of inorganic fillers include aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, calcium silicate, magnesium silicate, calcium oxide, magnesium oxide, alumina (aluminum oxide), aluminum nitride, aluminum borate whiskers, and boron nitride. , crystalline silica, amorphous silica, silicon nitride, talc, mica, and barium sulfate.
Among them, alumina, boron nitride, or aluminum nitride is preferable because of its high thermal conductivity, good heat dissipation, easy control of impurities, and good heat resistance and insulating properties.
A filler may be used individually by 1 type, and may use 2 or more types.

The average particle size of the filler contained in the adhesive layer is not particularly limited. For example, from the viewpoint of thermal conductivity, it is preferably 0.1 to 10 μm, more preferably 0.2 to 5 μm.

The content of the filler in the adhesive layer is 50% by volume or less (for example, 20% by volume or more and 50% by volume or less) relative to the total volume of the adhesive layer from the viewpoint of balancing adhesiveness and thermal conductivity. is also preferred.

In particular, the adhesive layer contains at least one selected from the group consisting of epoxy compounds and modified polyamideimide resins as a compound having adhesiveness, and at least one selected from the group consisting of alumina and silicon oxide as a filler. , The content of the filler is 25 parts by volume or more and 100 parts by volume or less with respect to 100 parts by volume of the compound having adhesiveness, and the average particle size of the filler is 0.2 to 5 μm. is preferable from the viewpoint of

The thickness of the adhesive layer is preferably 1 to 16 μm, more preferably 2 to 15 μm, even more preferably 3 to 14 μm, particularly preferably 4 to 12 μm, from the viewpoint of thermal conductivity and adhesion.
The film thickness of the adhesive layer can be measured using a micrometer, a stylus film thickness meter, a needle film thickness meter, or the like.

<Adhesive layer>
As the material of the pressure-sensitive adhesive layer, various pressure-sensitive adhesives and/or thermosetting materials can be used without particular limitation as long as they have the required heat resistance performance and heat conduction performance. Moreover, you may use the adhesive which mixed various heat conductive fillers in the adhesive layer, and improved thermal conductivity.

Examples of adhesives forming the adhesive layer include acrylic adhesives, olefin adhesives, silicone adhesives, natural rubber adhesives, and synthetic rubber adhesives.
For applications near semiconductors in electronic devices, acrylic pressure-sensitive adhesives or olefin-based pressure-sensitive adhesives are preferable because outgassing is less likely to occur. Moreover, from the viewpoint of heat resistance, a silicone-based pressure-sensitive adhesive containing a silicone resin as a main raw material is preferable.
The "adhesive containing a silicone resin as a main raw material" is an adhesive containing 60% by mass or more (preferably 80% by mass or more) of a silicone resin.
Examples of adhesives containing silicone resin as a main raw material include peroxide cross-linking (curing) silicone adhesives and addition reaction silicone adhesives. Among them, the addition reaction type silicone-based pressure-sensitive adhesive is preferable because it has high thickness accuracy when formed into a thin layer and is easy to form a pressure-sensitive adhesive layer by a transfer method.

The addition-reactive silicone pressure-sensitive adhesive, for example, contains a silicone rubber and a silicone resin, and if necessary, a cross-linking agent, a filler, a plasticizer, an anti-aging agent, an antistatic agent, and/or a coloring agent. Adhesives containing additives such as (pigments, dyes, etc.) can be mentioned.

The silicone rubber is not particularly limited as long as it is a silicone-based rubber component, but a silicone rubber containing an organopolysiloxane having a phenyl group (in particular, an organopolysiloxane having methylphenylsiloxane as a main constituent unit). is preferred. Various functional groups such as a vinyl group may be introduced into the organopolysiloxane in such a silicone rubber, if necessary.

_The silicone resin is not particularly limited as long as it is a silicone-based resin _that is used in silicone-based _pressure -sensitive adhesives. A (co)polymer having at least one unit selected from the group consisting of a unit consisting of a unit consisting of a structural unit "RSiO _3/2 " and a unit consisting of a structural unit "R ₂ SiO" Examples include silicone resins containing organopolysiloxanes. In addition, R in the above structural unit represents a hydrocarbon group or a hydroxyl group.

Examples of acrylic pressure-sensitive adhesives include homopolymers and copolymers of (meth)acrylic acid and/or (meth)acrylic acid esters.

Among them, acrylic pressure-sensitive adhesives are mainly made of butyl acrylate or 2-ethylhexyl acrylate, etc., in terms of excellent flexibility, chemical stability, workability, and/or controllability of adhesiveness. A poly(meth)acrylic acid ester-based polymer compound as a component is preferred.

The polymer compound is obtained by copolymerizing one or more monomers selected from butyl acrylate, ethyl acrylate, 2-ethylhexyl acrylate, and the like, with acrylic acid, acrylonitrile, and/or hydroxyethyl acrylate, and the like; A copolymer having a structure in which a polar group such as a COOH group, --CN group, or --OH group is introduced is preferred.

In addition, a crosslinked structure may be introduced into the acrylic pressure-sensitive adhesive within a range that does not impair flexibility. By introducing a crosslinked structure, it is easy to improve long-term adhesion retention and film strength. For example, a crosslinked structure can be introduced by reacting a polymer having a polar group such as an —OH group with a compound having a functional group that binds to the polar group, such as a plurality of isocyanate groups or epoxy groups, with the polar group. .

[Device with thermal conductive layer]
A thermally conductive material obtained using the composition of the present invention 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 heat conductive material of the present invention is arranged on a device to produce a device with a heat conductive layer, and heat generated from the device can be efficiently radiated by the heat conductive layer. The thermally conductive layer may be a thermally conductive layer containing the thermally conductive multilayer sheet described above.
Since the thermally conductive material obtained using the composition of the present invention has sufficient thermal conductivity and high heat resistance, it can be used in various electrical devices such as personal computers, general home appliances, and automobiles. It is suitable for heat dissipation applications of power semiconductor devices.
Furthermore, the thermally conductive material obtained using the composition of the present invention has sufficient thermal conductivity even in a semi-cured state, so that light for photocuring can reach the gaps between members of various devices. It can also be used as a heat dissipating material to be placed in areas where it is difficult to dissipate heat. Moreover, since it is excellent in adhesiveness, it can be used as an adhesive having thermal conductivity.

EXAMPLES The present invention will be described in more detail below with reference to examples. The materials, amounts used, proportions, treatment details, treatment 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 to be limited by the examples shown below.

[Examples 1 to 40 and Comparative Examples 1 to 12 (preparation of compositions)]
[Various components]
Various components used in Examples and Comparative Examples are shown below.
<Specific compound and comparative compound>
Specific compounds used in the examples are shown below. The following C-1 to C-11 are specific compounds, and D-1 to D-2 are compounds (comparative compounds) that do not correspond to the specific compounds.

<Phenol compound>
Phenolic compounds A-1 to A-3 used in the examples are shown below.
The phenol compound A-1 used in the examples was synthesized with reference to US Pat. No. 4,992,596.

<Epoxy compound>
The epoxy compounds used in Examples and Comparative Examples are shown below. C-11 below is a specific compound, and B-1 to B-3 are compounds that do not fall under the specific compound.
B-2 below is a mixture of two types of epoxy compounds (trade name: Epotato ZX-1059, manufactured by Tohto Kasei Co., Ltd.).

<Inorganic substances (inorganic nitrides and other inorganic substances)>
Inorganic substances used in Examples and Comparative Examples are shown below.
"AA-3": aluminum oxide (average particle size: 3 μm, manufactured by Sumitomo Chemical)
"AA-04": aluminum oxide (average particle size: 0.4 μm, manufactured by Sumitomo Chemical)
“HP-40 MF100”: aggregated boron nitride (average particle size: 40 μm, made by Mizushima ferroalloy)
“SP-3”: Scale-like boron nitride (average particle size: 4 μm, manufactured by Denka Co., Ltd.)

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

<Solvent>
Cyclopentanone was used as solvent.

<Dispersant>
DISPERBYK-106 (a polymer salt having an acidic group) was used as a dispersant.

<Surface modifier for aluminum oxide (organosilane molecule)>
The following compounds were used as surface modifiers for aluminum oxide.

[Examples 1 to 40 and Comparative Examples 1 to 12 (preparation of compositions)]
A curing liquid was prepared by blending the epoxy compound and the phenol compound in the combinations shown in Tables 1 to 3 below in the amounts (g) shown in Tables 1 to 3 below.
After mixing the total amount of the obtained curing liquid, solvent, dispersant, surface modifier (surface modifier for aluminum oxide), and curing accelerator in this order, inorganic substances (inorganic nitrides, inorganic oxides) were added. . The resulting mixture was processed for 5 minutes in a rotation-revolution mixer (Awatori Mixer ARE-310, manufactured by THINKY) to obtain a composition (composition for forming a heat conductive material) of each example or comparative example.
In Tables 1 to 3 below, for example, Example 1 and Example 31 have the same composition, but are examples in which the methods for preparing the evaluation objects described later are different.

Here, the amount of solvent added was such that the solid content concentration of the composition was 50 to 80% by mass.
The solid content concentration of the composition was adjusted for each composition within the above range so that the viscosities of the compositions were approximately the same.
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 total content of the epoxy compound and the specific compound having an epoxy group.
The amount of inorganic material added (total amount of inorganic nitride and other inorganic material added) was the amount (g) shown in Tables 1 to 3 below.
In addition, the inorganic substances were mixed and used so that the content ratio (mass ratio) of each inorganic substance satisfies the relationships shown in Tables 1 to 3 below.
The amount of the dispersant added was such that the content of the dispersant in the composition was 0.2% by mass with respect to the content of the inorganic substance.
The amount of the surface modifier for aluminum oxide added is such that the content of the surface modifier for aluminum oxide in the composition is 0 with respect to the content of aluminum oxide (total content of AA-3 and AA-04). .2% by mass. When the composition does not contain aluminum oxide, no surface modifier for aluminum oxide is used.

[Production method A: Examples 1 to 15, 18 to 19, 22 to 25, 28 to 29 and Comparative Examples 1 and 2 (production of heat conductive sheets)]
<Preparation of heat conductive sheet>
Using an applicator, on the release surface of a release-treated polyester film (NP-100A manufactured by Panac, film thickness 100 μm), the prepared composition shown in Tables 1 to 3 below is uniformly applied, and 120 C. for 5 minutes to obtain a coating film.
Two such polyester films with a coating film are prepared, and the two polyester films with a coating film are laminated to each other at the coating film surfaces, and then a flat plate is hot pressed under air (hot plate temperature 65 ° C., pressure 12 MPa for 1 minute) to obtain a semi-cured film.
The resulting semi-cured film is hot-pressed in air (hot plate temperature 160° C., pressure 12 MPa for 20 minutes, and then under normal pressure 180° C. for 90 minutes) to cure the coating film and form a resin sheet. got The polyester films on both sides of the resin sheet were peeled off to obtain a thermal conductive sheet with an average thickness of 200 μm.

[Production method A: Examples 16-17, 20-21 and 26-27 (production of thermally conductive multilayer sheets)]
<Preparation of semi-cured film>
Using an applicator, on the release surface of a release-treated polyester film (NP-100A manufactured by Panac, film thickness 100 μm), the prepared composition shown in Tables 1 to 3 below is uniformly applied, and 120 C. for 5 minutes to obtain a coating film.
Two such polyester films with a coating film are prepared, and the two polyester films with a coating film are laminated to each other at the coating film surfaces, and then a flat plate is hot pressed under air (hot plate temperature 65 ° C., pressure 12 MPa for 1 minute) to obtain a semi-cured film.

<Preparation of Adhesive Layer Film 1 (Epoxy Adhesive Layer, No Filler)>
21.6 parts of B-3 as an epoxy resin, 13.3 parts of A-1 as a curing agent, 0.21 parts of PPh ₃ (triphenylphosphine) as a curing accelerator, and 64.9 parts of cyclopentanone are mixed. Thus, an adhesive layer coating liquid was obtained.
Using an applicator, the prepared adhesive layer coating solution is uniformly applied on the release surface of a release-treated polyester film (NP-100A manufactured by Panac, film thickness 100 μm), and heated at 120° C. for 5 minutes. It was left to stand to obtain a coating film. The film thickness of the adhesive layer was set to 5 μm.

<Preparation of Adhesive Layer Film 2 (Epoxy Adhesive Layer, with Filler)>
21.6 parts of B-3 as an epoxy resin, 13.3 parts of A-1 as a curing agent, 0.21 parts of PPh ₃ as a curing accelerator, 35 parts of alumina AA-04, and 100 parts of cyclopentanone By mixing, a coating liquid for an adhesive layer was obtained.
Using an applicator, the prepared adhesive layer coating solution is uniformly applied on the release surface of a release-treated polyester film (NP-100A manufactured by Panac, film thickness 100 μm), and heated at 120° C. for 5 minutes. It was left to stand to obtain a coating film. The film thickness of the adhesive layer was set to 5 μm.

<Preparation of multilayer sheet>
The release PET placed on both sides of the semi-cured film prepared above was peeled off, and adhesive layer films having adhesive layers described in Tables 1 to 3 below were placed so that the adhesive layers faced the semi-cured film. , and an adhesive layer was attached using a laminator under conditions of a temperature of 120° C., a pressure of 0.7 MPa, a degree of vacuum of ≦1 kPa, and a time of 15 seconds to obtain a multilayer sheet.

<Production of Cured Multilayer Sheet>
The resulting multilayer sheet is hot-pressed in air (hot plate temperature 160° C., pressure 12 MPa for 20 minutes, then under normal pressure 180° C. for 90 minutes) to cure the coating film and form a resin sheet. Obtained. The polyester films on both sides of the resin sheet were peeled off to obtain a cured multilayer sheet (heat conductive multilayer sheet) having an average film thickness of 200 μm.

[Production method B: Examples 31, 34 to 35 and Comparative Examples 3 to 5 (production of heat conductive sheets)]
<Preparation of heat conductive sheet>
Using an applicator, on the release surface of a release-treated PET film (PET756501, manufactured by Lintec Corporation, film thickness 75 μm), the prepared composition shown in Tables 1 to 3 below is uniformly applied and heated at 120 ° C. and left for 4 minutes to obtain a coating film.
On the surface of the coating film, a new polyester film was further laminated with the mold release side facing each other. A semi-cured film was obtained by roll-pressing the coating film sandwiched between the polyester films in air. During roll pressing, the film surface of the coating film was heated to 100° C., and the linear pressure was 544 N/cm.
The resulting semi-cured film is hot-pressed in air (hot plate temperature 160° C., pressure 12 MPa for 20 minutes, and then under normal pressure 180° C. for 90 minutes) to cure the coating film and form a resin sheet. got The polyester films on both sides of the resin sheet were peeled off to obtain a thermal conductive sheet with an average thickness of 200 µm.

[Production method B: Examples 32-33 and Comparative Examples 6-7 (production of thermally conductive multilayer sheets)]
A cured multilayer sheet (thermally conductive multilayer sheet) was obtained in the same manner as in Example 16, except that a semi-cured film prepared by the following method was used.
<Preparation of semi-cured film>
Using an applicator, on the release surface of a release-treated PET film (PET756501, manufactured by Lintec Corporation, film thickness 75 μm), the prepared composition shown in Tables 1 to 3 below is uniformly applied and heated at 120 ° C. and left for 4 minutes to obtain a coating film.
On the surface of the coating film, a new polyester film was further laminated with the mold release side facing each other. A semi-cured film was obtained by roll-pressing the coating film sandwiched between the polyester films in air. During roll pressing, the film surface of the coating film was heated to 100° C., and the linear pressure was 544 N/cm.

[Production method C: Examples 36, 39 to 40 and Comparative Examples 8 to 10 (production of thermally conductive sheets)]
<Preparation of heat conductive sheet>
Using an applicator, on the release surface of a release-treated PET film (PET756501, manufactured by Lintec Corporation, film thickness 75 μm), the prepared composition shown in Tables 1 to 3 below is uniformly applied and heated at 120 ° C. After heating for 4 minutes at 80° C. for 2 minutes, a semi-cured film was obtained.
The resulting semi-cured film is hot-pressed in air (hot plate temperature 160° C., pressure 12 MPa for 20 minutes, and then under normal pressure 180° C. for 90 minutes) to cure the coating film and form a resin sheet. got The polyester films on both sides of the resin sheet were peeled off to obtain a thermal conductive sheet with an average thickness of 200 µm.

[Production method C: Examples 37-38 and Comparative Examples 11-12 (production of thermally conductive multilayer sheets)]
A cured multilayer sheet (thermally conductive multilayer sheet) was obtained in the same manner as in Example 16, except that a semi-cured film prepared by the following method was used.
<Preparation of semi-cured film>
Using an applicator, on the release surface of a release-treated PET film (PET756501, manufactured by Lintec Corporation, film thickness 75 μm), the prepared composition shown in Tables 1 to 3 below is uniformly applied and heated at 120 ° C. After heating for 4 minutes at 80° C. for 2 minutes, a semi-cured film was obtained.

[Examples 1 to 40 and Comparative Examples 1 to 12 (evaluation of thermally conductive sheets and thermally conductive multilayer sheets)]
<Thermal conductivity>
Thermal conductivity evaluation was performed using each thermally conductive sheet and thermally conductive multilayer sheet obtained using each composition. 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 thermal conductive sheet was measured by the laser flash method.
(2) Using a balance “XS204” manufactured by Mettler-Toledo, the specific gravity of the heat conductive sheet was measured by the Archimedes method (using “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 thermal conductive sheet.

(Evaluation criteria)
The measured thermal conductivity was categorized according to the following criteria, and the thermal conductivity was evaluated.
"A": 17 W/m·K or more "B": 13 W/m·K or more and less than 17 W/m·K "C": 10 W/m·K or more and less than 13 W/m·K "D": 10 W/m·K or more Less than K The results are shown in Tables 1 to 3 below.

<Water resistance>
Water resistance was evaluated using each thermally conductive sheet and thermally conductive multilayer sheet obtained using each composition. The water content was measured by the method described below, and the water resistance was evaluated according to the criteria below.

(Measurement of water resistance)
The heat conductive sheet after curing was exposed to wet heat conditions of 85° C. and 85% for 48 hours, and the moisture content was calculated from the change in sheet weight before and after.
"A": Less than 0.6% "B": 0.6% or more and less than 0.8% "C": 0.8% or more and less than 1.0% "D": 1.0% or more The results are shown in the table below. 1 to Table 3.

[result]
Tables 1 to 3 below show the types and amounts (g) of phenolic compounds, epoxy compounds, inorganic substances, curing accelerators, and adhesive layers used in each thermally conductive sheet and thermally conductive multilayer sheet, and the addition of dispersants. The evaluation results are shown together with the amount (g).

From the results shown in Tables 1 to 3, it was confirmed that a thermally conductive sheet and a thermally conductive multilayer sheet having excellent thermal conductivity can be obtained by using the composition of the present invention. Moreover, it was confirmed that the thermally conductive sheet and the thermally conductive multilayer sheet obtained using the composition are excellent in water resistance.
In addition, even when a semi-cured film is produced using a press such as a flat plate press or a roll press, or when a semi-cured film is produced without using a press, the thermally conductive material formed from the composition of the present invention is the same. It was confirmed that the effects of the invention can be realized.

It was confirmed that the thermal conductivity of the resulting thermally conductive sheet is superior under the condition that L of the specific compound is "a divalent organic group having a divalent aromatic ring group" (Examples 1 to 6, 9-10 with Examples 7 and 8).

It was confirmed that when the specific compound has a Hansen solubility parameter of 28 or less, the resulting thermally conductive sheet and thermally conductive multilayer sheet are excellent in water resistance (Examples 1 to 30 and Comparative Example 2, Comparative Example 1 and comparison).
It was also confirmed that when the specific compound has a Hansen solubility parameter of 26 or less, the obtained thermally conductive sheet and thermally conductive multilayer sheet are more excellent in water resistance (Examples 1, 3 to 6, 8, 13 to 15 and comparison of Comparative Example 1 with Examples 2, 7, 9-12, 16-30 and Comparative Example 2).

It was confirmed that the thermal conductivity was superior under the condition that 75% by mass or more of the inorganic material contained in the thermal conductive sheet was boron nitride (comparison between Examples 18-19 and Examples 22-23).
In addition, it was confirmed that the thermal conductivity was superior under the condition that the composition of the inorganic substance contained in the thermally conductive multilayer sheet was 80% by mass or more of boron nitride (comparison between Examples 16-17 and Examples 20-21). ).

Claims (12)

A composition for forming a thermally conductive material, comprising inorganic particles and a compound represented by general formula (1).

In the general formula (1),
E ¹ to E ⁶ each independently represent -NH- or -NR-. R represents a substituent.
B ¹ , B ² , B ³ , and B ⁴ each represent a k+1-valent, l+1-valent, m+1-valent, and n+1-valent organic group, at least one of which optionally has a substituent k+1 represents a valent, l+1-valent, m+1-valent, or n+1-valent aromatic ring group.
L represents a divalent organic group.
k, l, m, and n each independently represent an integer of 0 or greater.
When k is 2 or more, k X ¹ 's may be the same or different.
When l is 2 or more, l occurrences of X ² may be the same or different.
When m is 2 or more, m X ³ may be the same or different.
When n is 2 or more, n X ⁴ may be the same or different.
Also, the sum of k, l, m, and n is 2 or more.
X ¹ to X ⁴ each independently represent a group represented by general formula (2).

In the general formula (2), * represents a bonding position.
D ¹ represents a single bond or a divalent linking group.
A ¹ represents an optionally substituted aromatic ring group or an optionally substituted aliphatic ring group.
Q and Y ¹ are each independently selected from the group consisting of a monovalent group having a hydroxyl group, an epoxy group, an amino group, a thiol group, a carboxylic acid group, an isocyanate group, and a monovalent group having an oxetanyl group. represents a specific functional group.
p represents an integer of 0 or more.
q represents an integer of 0 to 2;
In general formula (2), when there are a plurality of D ¹ 's, the plurality of D ¹ 's may be the same or different. When there are multiple A ¹ 's, the multiple A ¹ 's may be the same or different. When there are multiple Q's, the multiple Q's may be the same or different.
r is an integer of 1 or more. L in the general formula (1) is a divalent aromatic ring group which may have a substituent, a divalent aliphatic ring group which may have a substituent, and a carbon number of 2 or more 2. The composition for forming a thermally conductive material according to claim 1, which is a divalent organic group having at least one selected from the group consisting of an alkylene group which may have a branch of . 3. The composition for forming a heat conductive material according to claim 1, wherein L in the general formula (1) is a divalent organic group having an optionally substituted divalent aromatic ring group. thing. 4. The composition for forming a thermally conductive material according to claim 1, wherein the compound represented by the general formula (1) has a Hansen solubility parameter value of 28 MPa ^0.5 or less. The composition for forming a thermally conductive material according to any one of claims 1 to 4, wherein the compound represented by the general formula (1) has a Hansen solubility parameter value of 26 MPa ^0.5 or less. The composition for forming a thermally conductive material according to any one of claims 1 to 5, further comprising a curing accelerator. 7. The composition for forming a thermally conductive material according to claim 1, wherein said inorganic particles are inorganic nitrides. 8. The composition for forming a thermally conductive material according to claim 1, wherein said inorganic particles are boron nitride. The compound according to any one of claims 1 to 8, wherein the content of the compound represented by the general formula (1) is 3 to 40% by mass with respect to the total solid content of the composition for forming a thermally conductive material. A composition for forming a thermally conductive material as described. A thermally conductive sheet formed by curing the composition for forming a thermally conductive material according to any one of claims 1 to 9. The heat conductive sheet according to claim 10;
A thermally conductive multilayer sheet having an adhesive layer or a pressure-sensitive adhesive layer provided on one side or both sides of the thermally conductive sheet. a device;
A device with a thermally conductive layer, comprising: a thermally conductive layer comprising the thermally conductive sheet according to claim 10 or the thermally conductive multilayer sheet according to claim 11, disposed on the device.