JP2024029371A - Thermal conductive composition and thermally conductive sheet - Google Patents

Abstract

An object of the present invention is to provide a thermally conductive composition from which a thermally conductive sheet having high thermal conductivity and a thick film can be obtained with good productivity by light irradiation. A thermally conductive composition containing at least one of a radically polymerizable monomer and a partial polymer thereof, a binder component containing a photopolymerization initiator, and a thermally conductive filler, the binder component being 100 parts by volume. In contrast, a thermally conductive composition in which the thermally conductive filler is 100 parts by volume or more and 900 parts by volume or less, and the photopolymerization initiator is a triazine peroxide derivative represented by the following general formula (1). JPEG2024029371000014.jpg53159 [Selection diagram] None

Description

The present invention relates to a thermally conductive composition and a thermally conductive sheet.

It is important to dissipate heat generated from various electronic and electrical devices. In recent years, high performance and diversification have progressed, and heat dissipation countermeasure components are used between a heat generating body such as an IC device and a heat dissipating body such as a heat sink in automotive electrical component applications and communication equipment applications, and are used as materials with high thermal conductivity. , there is a demand for thick film heat dissipation countermeasure members. Heat dissipation countermeasure members include heat dissipation sheets, heat dissipation gap fillers, heat dissipation adhesives, heat dissipation grease, etc., but there is no need to particularly control the amount of application, and there is no fluidity, so they are sandwiched between the desired heat generating element and heat dissipation body. Thermal conductive sheets are attracting attention because of their excellent workability.

One way to increase the thermal conductivity of a thermally conductive sheet is to increase the content of a thermally conductive filler, and Patent Document 1 discloses a method for producing a thermally conductive sheet with high thermal conductivity and a thick film by thermosetting. ing. Moreover, in order to improve productivity, in Patent Documents 2 and 3, a thermally conductive sheet is produced by photocuring by ultraviolet irradiation using a photopolymerizable composition containing a photopolymerization initiator.

Japanese Patent Application Publication No. 2006-111644 JP2019-85441A JP2020-45386A

Against this background, demand for thermally conductive sheets is expected to increase, and the method of manufacturing thick thermally conductive sheets by thermosetting as in Patent Document 1 has a higher curing efficiency than curing by ultraviolet irradiation. Because of the low molecular weight, polymerization takes a long time at high temperatures, and even if the polymerization conditions are optimized, there is a limit to shortening the polymerization time.

On the other hand, in the method of producing a thermally conductive sheet by photocuring as in Patent Documents 2 and 3, if the content of the thermally conductive filler is increased, even when irradiated with light such as ultraviolet rays, the light transmittance decreases, causing deep penetration. Since it is difficult to reach the target area, the film thickness is limited, resulting in a thin sheet. Therefore, in order to produce a thick thermally conductive sheet, the content of filler is limited, resulting in a sheet with low thermal conductivity.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a thermally conductive composition from which a thermally conductive sheet having high thermal conductivity and a thick film can be obtained with good productivity by light irradiation.

Another object of the present invention is to provide a thermally conductive sheet that is a cured product of the thermally conductive composition.

The present invention is a thermally conductive composition containing at least one of a radically polymerizable monomer and a partial polymer thereof, a binder component containing a photopolymerization initiator, and a thermally conductive filler, wherein 100 parts by volume of the binder component In contrast, the present invention relates to a thermally conductive composition in which the thermally conductive filler is 100 parts by volume or more and 900 parts by volume or less, and the photopolymerization initiator is a triazine peroxide derivative represented by the following general formula (1).
((In general formula (1), R ¹ and R ² are independently a methyl group or an ethyl group, R ³ is an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or a carbon number that may have an alkyl group. represents an aromatic hydrocarbon group having 6 to 9 carbon atoms, R ⁴ is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, and an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms; , an optionally substituted heterocyclic group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, -Y-R, or -N-RR', where Y is Represents an oxygen atom or a sulfur atom, R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, and an optionally substituted aromatic group having 6 to 20 carbon atoms. represents a group hydrocarbon group, an optionally substituted heterocyclic group having 2 to 20 carbon atoms.Ar is an aryl group represented by the following general formula (2): Ar ¹ , Ar ² , or Ar ³ .)
(In general formula (2), m represents an integer from 0 to 3, R ⁵ is an independent substituent, and is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, an optionally substituted heterocyclic group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, -Y- R or -N-RR', Y represents an oxygen atom or a sulfur atom, R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms; , an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, and an optionally substituted heterocyclic group having 2 to 20 carbon atoms.)

The present invention also relates to a thermally conductive sheet that is a cured product of a thermally conductive composition.

The thermally conductive composition of the present invention has high thermal conductivity with good productivity when photocured by irradiating ultraviolet rays even when highly filled with a filler having high thermal diffusivity such as a thermally conductive filler. A thermally conductive sheet with a thick film can be produced.

The thermally conductive composition of the present invention contains at least one of a radically polymerizable monomer and a partial polymer thereof, a binder component containing a photopolymerization initiator, and a thermally conductive filler. When the thermally conductive composition is photocured by irradiation with ultraviolet rays, the triazine peroxide derivative is quickly activated and is not easily affected by the thermal diffusivity of the highly filled thermally conductive filler. A thermally conductive sheet with high thermal conductivity and a thick film can be produced.

<Radical polymerizable monomer>
As the radically polymerizable monomer, a compound having an ethylenically unsaturated group can be preferably used. Examples of radically polymerizable monomers include (meth)acrylic esters, styrenes, maleic esters, fumaric esters, itaconic esters, cinnamic esters, crotonic esters, vinyl ethers, and vinyl esters. , vinyl ketones, allyl ethers, allyl esters, N-substituted maleimides, N-vinyl compounds, unsaturated nitriles, and olefins. Among these, it is preferable to include highly reactive (meth)acrylic esters. The radically polymerizable monomers may be used alone or in combination of two or more types.

As the (meth)acrylic esters, monofunctional compounds and polyfunctional compounds can be used. Monofunctional compounds include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate. Alkyl (meth)acrylates such as acrylate; cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth) Ester compounds of (meth)acrylic acid and alicyclic alcohol such as acrylate and 2-ethyl-2-adamantyl (meth)acrylate; aryl (meth)acrylates such as phenyl (meth)acrylate and benzyl (meth)acrylate ; 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, hydroxyl-terminated polyethylene glycol mono( Monomers with hydroxy groups such as meth)acrylate, hydroxyl-terminated polypropylene glycol mono(meth)acrylate; methoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, 2-phenylphenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, (3-ethyloxetan-3-yl)methyl ( Monomers having a chain or cyclic ether bond such as meth)acrylate, cyclic trimethylolpropane formal (meth)acrylate; N,N-dimethylaminoethyl (meth)acrylate, N,N-dimethyl(meth)acrylamide, N - Methylol (meth)acrylamide, N-isopropyl (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, diacetone (meth)acrylamide, (meth)acryloylmorpholine, N-(meth)acryloyloxyethylhexahydrophthalimide Monomers having a nitrogen atom such as; monomers having an isocyanate group such as 2-(meth)acryloyloxyethyl isocyanate; monomers having an epoxy group such as glycidyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate glycidyl ether; Acid monomers having a phosphorus atom such as 2-((meth)acryloyloxy)ethyl; monomers having a silicon atom such as 3-(meth)acryloxypropyltrimethoxysilane; 2,2,2-trifluoroethyl (meth) Fluorine atom-containing monomers such as acrylate, 2,2,3,3,3-pentafluoropropyl (meth)acrylate, 2-(perfluorohexyl)ethyl (meth)acrylate; (meth)acrylic acid, succinic acid mono( 2-(meth)acryloyloxyethyl), mono(2-(meth)acryloyloxyethyl) phthalate, mono(2-(meth)acryloyloxyethyl) maleate, ω-carboxy-polycaprolactone mono(meth)acrylate, etc. Examples include monomers having a carboxyl group.

The polyfunctional compounds include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolethane tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, pentaerythritol di( meth)acrylate monostearate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, hydroxypivalate neopentyl glycol di(meth)acrylate, glycerin propoxytri(meth)acrylate tricyclodecane dimethanol di (meth)acrylate, 2,2-bis(4-(meth)acryloxypolyethoxyphenyl)propane, 2,2-bis(4-(meth)acryloxyethoxyphenyl)propane, 9,9-bis(4- Polyhydric alcohols such as (2-(meth)acryloyloxyethoxy)phenyl)fluorene, 9,9-bis(4-(2-(2-(meth)acryloyloxyethoxy)ethoxy)phenyl)fluorene, and (meth)acrylic Ester compounds with acids; bis(4-(meth)acryloxyphenyl) sulfide, bis(4-(meth)acryloylthiophenyl) sulfide, tris(2-(meth)acryloyloxyethyl)isocyanurate, ethylene bis(meth) ) Acrylamide, zinc (meth)acrylate, zirconium (meth)acrylate, aliphatic urethane acrylate, aromatic urethane acrylate, epoxy acrylate, polyester acrylate, and the like.

<Partial polymer of radically polymerizable monomer>
Since the radically polymerizable monomer generally has a low viscosity, the filler may settle when mixed with a thermally conductive filler. In this case, it is preferable that the radically polymerizable monomer is partially polymerized in advance to thicken the radically polymerizable monomer to obtain a partial polymer of the radically polymerizable monomer. The viscosity of the partial polymer of the radically polymerizable monomer is not particularly limited, but it is preferably about 10 to 10,000 mPa·s.

Partial polymerization can be carried out by various methods, and known polymerization methods such as solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization can be employed. During polymerization, a partial polymer can be obtained by using a polymerization initiator such as a thermal polymerization initiator or a photopolymerization initiator depending on the polymerization method.

Examples of thermal polymerization initiators used in partial polymerization include diacyl peroxides, peroxyketals, ketone peroxides, hydroperoxides, dialkyl peroxides, peroxyesters, and peroxydicarbonates. Organic peroxides; azo polymerization initiators, etc. can be used. Specifically, lauroyl peroxide, benzoyl peroxide, cyclohexanone peroxide, 1,1-bis(t-butylperoxy)3,3,5-trimethylcyclohexane, t-butylhydroperoxide, 2,2'-azo Examples include bisbutyronitrile.

Photopolymerization initiators used for partial polymerization include aromatic ketones, benzoin ethers, halomethyloxadiazole compounds, α-aminoketones, α-aminoacetophenone compounds, acylphosphine compounds, biimidazoles, N,N-dimethylamino Examples include benzophenone, triazine compounds, thioxanthone compounds, and oxime compounds. Specific examples of the photopolymerization initiator include aromatic ketones such as benzophenone, 4,4'-bisdiethylaminobenzophenone, and 4-methoxy-4'-dimethylaminobenzophenone; benzoin ethers such as benzoin methyl ether; ethylbenzoin. benzoin such as; biimidazole such as 2-(o-chlorophenyl)-4,5-phenylimidazole dimer; 2-trichloromethyl-5-(p-methoxystyryl)-1,3,4-oxadiazole Halomethyloxadiazole compounds such as 2-(4-butoxy-naphth-1-yl)-4,6-bis-trichloromethyl-S-triazine, triazine peroxide derivatives represented by the following general formula (1), etc. Triazine compounds; 2,2-dimethoxy-1,2-diphenylethan-1-one, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone, 1,2-benzyl-2 -dimethylamino-1-(4-morpholinophenyl)-butanone-1,1-hydroxy-cyclohexyl-phenylketone, benzyl, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl sulfide, benzyl Methyl ketal, dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, 2-chlorothioxanthone, 2,4-diethylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 4-benzoyl-methyldiphenyl sulfide, 1-hydroxy-cyclohexyl-phenyl ketone, 2-benzyl-2-(dimethylamino)-1-[4-(4-morpholinyl)phenyl]-1-butanone, 2-(dimethylamino) )-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-1-butanone, α-dimethoxy-α-phenylacetophenone, phenylbis(2,4,6-trimethyl benzoyl)phosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-(4-morpholinyl)-1-propanone, 3-benzoyloxyiminobutan-2-one, 3-acetoxyiminobutan- Examples include 2-one and the like. Among these, from the viewpoint of curability during sheet production, it is preferable to use a triazine peroxide derivative represented by the following general formula (1). Alternatively, any combination of the thermal polymerization initiators or photopolymerization initiators described above can also be used.

<Photopolymerization initiator>
The photopolymerization initiator of the present invention contains a triazine peroxide derivative represented by the following general formula (1).
((In general formula (1), R ¹ and R ² are independently a methyl group or an ethyl group, R ³ is an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or a carbon number that may have an alkyl group. represents an aromatic hydrocarbon group having 6 to 9 carbon atoms, R ⁴ is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, and an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms; , an optionally substituted heterocyclic group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, -Y-R, or -N-RR', where Y is Represents an oxygen atom or a sulfur atom, R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, and an optionally substituted aromatic group having 6 to 20 carbon atoms. represents a group hydrocarbon group, an optionally substituted heterocyclic group having 2 to 20 carbon atoms.Ar is an aryl group represented by the following general formula (2): Ar ¹ , Ar ² , or Ar ³ .)
(In general formula (2), m represents an integer from 0 to 3, R ⁵ is an independent substituent, and is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, an optionally substituted heterocyclic group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, -Y- R or -N-RR', Y represents an oxygen atom or a sulfur atom, R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms; , an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, and an optionally substituted heterocyclic group having 2 to 20 carbon atoms.)

In general formula (1), R ¹ and R ² independently represent a methyl group or an ethyl group, and a methyl group is preferable from the viewpoints of high decomposition temperature and high storage stability of the polymerizable composition.

In the general formula (1), R ³ represents an aliphatic hydrocarbon group having 1 to 5 carbon atoms or an aromatic hydrocarbon group having 6 to 9 carbon atoms which may have an alkyl group. The alkyl group may be linear or branched. Specific examples of R ³ include a methyl group, an ethyl group, a propyl group, a 2,2-dimethylpropyl group, a phenyl group, an isopropylphenyl group, and the like. Among these, methyl group, ethyl group, propyl group, 2,2-dimethylpropyl group, and phenyl group are preferable from the viewpoint of easy synthesis of the triazine peroxide derivative. Since the decomposition temperature of the triazine peroxide derivative is high, the storage stability of the polymerizable composition is high, and the sensitivity to light is high, so methyl groups and ethyl groups are more preferable.

In general formula (1), R ⁴ is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, and an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. an optionally substituted acyl group having 1 to 20 carbon atoms, -Y-R, or -N-RR', where Y is an oxygen atom or a sulfur atom; , R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, Represents an optionally substituted heterocyclic group having 2 to 20 carbon atoms. Since the above-mentioned R ⁴ has a small influence on the absorption wavelength of the triazine peroxide derivative, good sensitivity is exhibited even if R ⁴ is within the above-mentioned wide range. In addition, the "substituent" in the above "may be substituted" includes a halogen atom, an aliphatic hydrocarbon group that may have an ether bond or a thioether bond in the carbon skeleton, an aromatic hydrocarbon group, Included are heterocycle-containing groups, acyl groups, cyano groups, nitro groups, carboxyl groups, epoxy groups, hydroxyl groups, and the like. From the viewpoint of high stability, the above R ⁴ is preferably an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, or an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. group, an optionally substituted heterocycle-containing group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, or -Y-R, from the viewpoint of easy synthesis, More preferably -O-R, where R is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, It is an optionally substituted heterocyclic group having 2 to 20 carbon atoms.

In general formula (2), m represents an integer from 0 to 3. From the viewpoint of easy synthesis, m is preferably from 0 to 2. From the viewpoint of efficiently absorbing light, m is preferably 1. It is more preferable that there be.

In the general formula (2), R ⁵ is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, and an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms. an optionally substituted acyl group having 1 to 20 carbon atoms, -Y-R, or -N-RR', where Y is an oxygen atom or a sulfur atom; , R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, Represents an optionally substituted heterocyclic group having 2 to 20 carbon atoms. Since the above R ⁵ has a small influence on the absorption wavelength of the triazine peroxide derivative, good sensitivity is exhibited even if R ⁵ is within the above wide range. In addition, the "substituent" in the above "may be substituted" includes a halogen atom, an aliphatic hydrocarbon group that may have an ether bond or a thioether bond in the carbon skeleton, an aromatic hydrocarbon group, Included are heterocycle-containing groups, acyl groups, cyano groups, nitro groups, carboxyl groups, epoxy groups, hydroxyl groups, and the like. The above R ⁵ is an independent substituent, and represents an alkyl group having 1 to 20 carbon atoms, a substituent represented by the general formula (3): R ⁶ -Y-, a nitro group, or a cyano group, The above Y represents an oxygen atom or a sulfur atom, and the above R ⁶ has 1 to 1 carbon atoms, which may have one or more of an ether bond, a thioether bond, and a hydroxyl group at the terminal in the carbon skeleton. 20 hydrocarbon group, an aromatic hydrocarbon group having 6 to 20 carbon atoms which may have an alkyl group, or ^an acyl group having 1 to 20 carbon atoms; General formula (3): R ⁶ -Y- may form a 5- to 6-membered ring.

Specific examples of the triazine peroxide derivative of the present invention are shown below, but the invention is not limited thereto.

The triazine peroxide derivatives of the present invention include Compound 19, Compound 23, Compound 25, Compound 26, Compound 27, Compound 31, Compound 32, Compound 33, Compound 35, Compound 37, Compound 38, Compound 39, Compound 43, Compound 44 , compound 45, compound 46, compound 47, compound 48, compound 49, compound 50, compound 51, compound 52, compound 53, compound 54, compound 55, compound 56, compound 57, compound 60, compound 61, compound 73, compound 77, compound 78, compound 79, and compound 81 are preferred.

<Method for producing triazine peroxide derivative>
The method for producing a triazine peroxide derivative represented by the general formula (1) includes a step of reacting cyanuric chloride and/or a derivative thereof with a hydroperoxide as a raw material. Such a production method includes, for example, a step of obtaining a cyanuric chloride derivative (hereinafter also referred to as steps (A) and (B)), as shown in the reaction formula below, and subsequently, the obtained cyanuric chloride derivative, Examples include a method including a step of reacting a hydroperoxide in the presence of an alkali (hereinafter also referred to as step (C)). The order of the above steps is not limited; for example, the reaction product of cyanuric chloride and hydroperoxide may be reacted with the following Ar-X or R ⁴ -X, or each step may be performed simultaneously. You may go. Before and after each step, a step of distilling off (removing) surplus raw materials and the like under reduced pressure, and a purification step may be included.
(In the above reaction formula, R ¹ , R ² , R ³ , R ⁴ and Ar are the same as in the above general formula (1).)

In the step (C), commercially available products can be used as the cyanuric chloride derivative. In addition, if there is no commercially available product, in the steps (A) and (B), known methods such as Grignard reaction, lithiation reaction, Suzuki coupling reaction, Friedel-Crafts reaction, nucleophilic substitution reaction in the presence of alkali, etc. It can be synthesized according to the synthesis method of .

<Synthesis of cyanuric chloride derivative by Grignard reaction>
In the steps (A) and (B), when cyanuric chloride derivatives are synthesized by Grignard reaction, they can be synthesized according to the known synthesis method described in JP-A-6-179661 and the like. A halogen compound in which X in Ar-X in the step (A) and R ⁴ -X in the step (B) is represented by a chlorine atom, a bromine atom, or an iodine atom can be used. A cyanuric chloride derivative can be synthesized by preparing a Grignard reagent by reacting a halogen compound and magnesium, and then reacting the obtained Grignard reagent with cyanuric chloride.

In the preparation of the Grignard reagent described above, magnesium is preferably used in an amount of 0.8 to 2.0 mol, more preferably 1 to 1.5 mol, per 1 mol of the halogen compound. As a reaction initiator, iodine, bromoethane, dibromoethane, etc. may be used, and it is preferable to use 0.0001 to 0.01 mole per mole of the halogen compound. The reaction temperature is preferably 0 to 70°C, more preferably 10 to 60°C. The reaction time is preferably 30 minutes to 20 hours, more preferably 1 hour to 10 hours.

In preparing the Grignard reagent described above, for example, a solvent such as ethers such as tetrahydrofuran can be used.

In addition, in the above-mentioned reaction between the Grignard reagent and cyanuric chloride, cyanuric chloride is preferably used in an amount of 0.7 to 1.5 mol, more preferably 0.8 to 1.2 mol, per 1 mol of the halogen compound. preferable. The reaction temperature is preferably -30 to 70°C, more preferably -10 to 40°C. The reaction time is preferably 10 minutes to 20 hours, more preferably 30 minutes to 15 hours. Note that cyanuric chloride may be added to the prepared Grignard reagent, or the Grignard reagent may be added to a solution of cyanuric chloride.

In the reaction between the Grignard reagent and cyanuric chloride, for example, a solvent such as ethers such as tetrahydrofuran can be used.

<Synthesis of cyanuric chloride derivative by lithiation reaction>
In the steps (A) and (B), when synthesizing the cyanuric chloride derivative by lithiation reaction, it can be synthesized according to the known synthesis method described in WO2012/096263 and the like. A halogen compound in which X in Ar-X in the step (A) and R ⁴ -X in the step (B) is represented by a chlorine atom, a bromine atom, or an iodine atom can be used. A cyanuric chloride derivative can be synthesized by preparing a lithio compound by reacting a halogen compound with a lithiation agent, and then reacting the obtained lithio compound with cyanuric chloride.

Examples of the lithiation agent include alkyllithiums such as methyllithium, n-butyllithium, s-butyllithium, and t-butyllithium; aryllithiums such as phenyllithium; lithium diisopropylamide, lithium bis(trimethylsilyl)amide, etc. Examples include lithium amides, with n-butyllithium, s-butyllithium, t-butyllithium, and phenyllithium being preferred.

In the preparation of the above lithio compound, the lithiation agent is preferably used in an amount of 0.8 to 3.0 mol, more preferably 1.0 to 2.2 mol, per 1 mol of the halogen compound. The reaction temperature is preferably -100 to 50°C, more preferably -80 to 0°C. The reaction time is preferably 0.2 to 20 hours, more preferably 0.5 to 10 hours.

In preparing the above lithio compound, for example, a solvent such as ethers such as tetrahydrofuran can be used.

Furthermore, in the above reaction between the lithio compound and cyanuric chloride, cyanuric chloride is preferably used in an amount of 0.7 to 1.5 mol, more preferably 0.8 to 1.2 mol, per 1 mol of the halogen compound. preferable. The reaction temperature is preferably -30 to 70°C, more preferably -10 to 40°C. The reaction time is preferably 10 minutes to 10 hours, more preferably 30 minutes to 5 hours. Note that cyanuric chloride may be added to the prepared lithio compound, or the lithio compound may be added to a solution of cyanuric chloride.

In the reaction between the lithio compound and cyanuric chloride, for example, a solvent such as ethers such as tetrahydrofuran can be used.

<Synthesis of cyanuric chloride derivatives by Suzuki coupling>
In the steps (A) and (B), when synthesizing the cyanuric chloride derivative by Suzuki coupling reaction, it can be synthesized according to the known synthesis method described in WO2012/096263 and the like. For example, by reacting the above lithio compound with a boron reagent, a boron compound in which X of Ar-X in the step (A) and R ⁴ -X in the step (B) is converted to a boronyl group or a boronic acid can be obtained. Can be synthesized. Next, a cyanuric chloride derivative can be synthesized by reacting the obtained boron compound with cyanuric chloride. In addition, when a commercially available boron compound is sold, it can be used as is.

Examples of the boron reagent include trimethyl borate, triisopropyl borate, 2-isopropoxy-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, and the like.

In the synthesis of the above boron compound, the boron reagent is preferably used in an amount of 0.8 to 3.0 mol, more preferably 1.0 to 2.0 mol, per 1 mol of the lithio compound. The reaction temperature is preferably -100 to 50°C, more preferably -80 to 20°C. The reaction time is preferably 10 minutes to 20 hours, more preferably 30 minutes to 10 hours.

In the synthesis of the above boron compound, for example, a solvent such as ethers such as tetrahydrofuran can be used.

Furthermore, in the reaction between the boron compound and cyanuric chloride, cyanuric chloride is preferably used in an amount of 0.7 to 1.5 mol, more preferably 0.8 to 1.2 mol, per 1 mol of the boron compound. preferable. The reaction temperature is preferably -30 to 70°C, more preferably -10 to 40°C. The reaction time is preferably 10 minutes to 10 hours, more preferably 30 minutes to 5 hours. Note that cyanuric chloride may be added to the boron compound, or the boron compound may be added to a solution of cyanuric chloride.

In the reaction between the boron compound and cyanuric chloride described above, it is preferable to use a palladium catalyst and an alkali, and a ligand may be added as necessary.

Examples of the palladium catalyst include palladium acetate, tetrakistriphenylphosphine palladium, bis(triphenylphosphine)palladium dichloride, (bis(diphenylphosphino)ferrocene)palladium dichloride-methylene chloride complex, and the like.

Examples of the alkali include inorganic bases such as alkali metal salts such as sodium carbonate, sodium hydrogen carbonate, sodium acetate, potassium acetate, and potassium phosphate; and organic bases such as triethylamine.

Examples of the ligand include organic compounds such as triphenylphosphine, tricyclohexylphosphine, 2,2'-bis(diphenylphosphino)-1,1'-binaphthalene, and 2-dicyclohexylphosphine-2,6'-dimethoxybiphenyl. Examples include phosphorus-based ligands.

In the reaction of the above boron compound and cyanuric chloride, ethers such as tetrahydrofuran and 1,4-dioxane; alcohols such as methanol and 2-propanol; aromatic hydrocarbons such as toluene and xylene; N,N-dimethyl Organic solvents such as amides such as formamide can be used. The organic solvents may be used alone or in combination of two or more. Furthermore, a mixed solvent of the organic solvent and water can be used.

<Synthesis of cyanuric chloride derivatives by Friedel-Crafts reaction>
In the steps (A) and (B), when the cyanuric chloride derivative is synthesized by Friedel-Crafts reaction, it can be synthesized according to the known synthesis method described in US Pat. No. 5,322,941 and the like. An aromatic compound in which X in Ar-X in the step (A) and R ⁴ -X in the step (B) is a hydrogen atom can be used. A cyanuric chloride derivative can be synthesized by reacting an aromatic compound with cyanuric chloride in the presence of a Lewis acid such as aluminum chloride.

The Lewis acids include aluminum chloride, aluminum bromide, iron (III) chloride, titanium (IV) chloride, tin (IV) chloride, zinc chloride, bismuth (III) triflate, hafnium (IV) triflate, and boron trifluoride. Diethyl ether complex etc. can be used.

In the above reaction between the aromatic compound and cyanuric chloride, cyanuric chloride is preferably used in an amount of 0.7 to 2.5 mol, more preferably 0.8 to 1.5 mol, per 1 mol of the aromatic compound. preferable. Aluminum chloride is preferably used in an amount of 1.0 to 3.0 mol, more preferably 1.0 to 2.0 mol, per 1 mol of the aromatic compound. The reaction temperature is preferably -50 to 60°C, more preferably 0 to 40°C. The reaction time is preferably 10 minutes to 10 hours, more preferably 30 minutes to 5 hours. Note that aluminum chloride may be added to a solution of an aromatic compound and cyanuric chloride, an aromatic compound may be added to a solution of cyanuric chloride and aluminum chloride, and cyanuric chloride may be added to a solution of an aromatic compound and aluminum chloride. Good too.

In the reaction of the above-mentioned aromatic compound and cyanuric chloride, a solvent such as dichloromethane, 1,2-dichloroethane, xylene, etc. can be used, for example.

<Synthesis of triazine peroxide derivative>
In the step (C), the method for producing the triazine peroxide derivative represented by the general formula (1) is not particularly limited, but may be performed according to the known synthesis method for triazine peroxide described in Japanese Patent Publication No. 45-39468, etc. Can be synthesized.

A triazine peroxide derivative is obtained by the step (C) of reacting the cyanuric chloride derivative obtained in the above steps (A) and (B) with a hydroperoxide in the presence of an alkali.

In the step (C), the hydroperoxide is preferably reacted with 0.9 mol or more, and preferably 1.0 mol or more with respect to 1 mol of the cyanuric chloride derivative, from the viewpoint of increasing the yield of the target product. is more preferable, and it is preferable that 3.0 mol or less is reacted, and it is more preferable that 2.0 mol or less is reacted. The hydroperoxide can be commercially available, and if there is no commercially available product, it can be synthesized according to the known synthesis method described in JP-A-58-72557 and the like.

In the step (C), the reaction temperature is preferably -10°C or higher, more preferably 0°C or higher, and 50°C or lower, from the viewpoint of increasing the yield of the target product. is preferable, and more preferably 40°C or lower.

In step (C), the reaction time cannot be determined unconditionally since it varies depending on the raw materials, reaction temperature, etc., but is usually preferably 10 minutes to 6 hours from the viewpoint of increasing the yield of the target product.

In the step (C), the alkali used is not particularly limited, but includes sodium hydroxide, potassium hydroxide, lithium hydroxide, potassium carbonate, sodium carbonate, sodium hydrogen carbonate, pyridine, α-picoline, γ-picoline, Examples include dimethylaminopyridine, triethylamine, tributylamine, N,N-diisopropylethylamine, and 1,5-diazabicyclo[4.3.0]-5-nonene. From the viewpoint of increasing the yield of the target product, the alkali is preferably used in an amount of 0.8 mol or more, more preferably 1.0 mol or more, and 3. It is preferable to use 0 mol or less, and more preferably 2.0 mol or less.

In the step (C), when the cyanuric chloride derivative is liquid, the reaction can be carried out without using an organic solvent. Moreover, when the cyanuric chloride derivative is solid, it is preferable to use an organic solvent. The organic solvent is not particularly limited as the solubility varies depending on the type of cyanuric chloride derivative, but examples include aromatic hydrocarbons such as toluene, xylene, and ethylbenzene, ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and tetrahydrofuran. , ethers such as dioxane, esters such as ethyl acetate and butyl acetate, and halogenated hydrocarbons such as methylene chloride and chloroform. The organic solvents may be used alone or in combination of two or more.

The amount of the organic solvent used is usually about 30 to 1000 parts by weight based on 100 parts by weight of the total amount of raw materials. The triazine peroxide derivative can be extracted by distilling off the organic solvent after step (C). In order to improve handling and reduce the risk of thermal decomposition, the triazine peroxide derivative can be used as a diluted product of the organic solvent. May be used.

The step (C) can be performed under normal pressure in air, but may also be performed under a nitrogen stream or a nitrogen atmosphere.

The purification step includes, for example, sodium bicarbonate, potassium bicarbonate, sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium sulfite, hydrogen chloride, sulfuric acid, Examples include a step of purifying the target product by washing with an aqueous electrolyte solution such as sodium chloride or ion-exchanged water.

The content of the triazine peroxide derivative is preferably from 0.01 to 40 parts by mass, and preferably from 0.05 to 20 parts by mass, based on 100 parts by mass of at least one of the radically polymerizable monomer and its partial polymer. It is more preferable that the amount is 0.1 to 10 parts by mass. If the content of the triazine peroxide derivative is less than 0.01 part by mass based on 100 parts by mass of at least one of the radically polymerizable monomer and its partial polymer, the curing reaction will not proceed, which is not preferable. Further, when the content of the triazine peroxide derivative is more than 40 parts by mass with respect to 100 parts by mass of at least one of the radically polymerizable monomer and the partial polymer thereof, the content of the triazine peroxide derivative is When the solubility of the photopolymerization initiator reaches saturation, crystals of the photopolymerization initiator may precipitate during film formation of the thermally conductive composition, resulting in a rough surface of the film, or the photopolymerization initiator itself absorbs light, causing the cured product to deteriorate. This is undesirable because the light does not reach deep inside. In addition, when the triazine peroxide derivative contains the following other polymerization initiator, the proportion of the other polymerization initiator is preferably 80% by mass or less in the total of the triazine peroxide derivative and the other polymerization initiator, More preferably, it is 50% by mass or less.

Furthermore, in addition to the triazine peroxide derivative described above, other polymerization initiators can be used in the thermally conductive composition to improve the surface curability, deep curability, etc. of the polymerizable composition. The other polymerization initiator is optional, such as a thermal polymerization initiator or a photopolymerization initiator. When selecting the other polymerization initiator, select at least one of a radically polymerizable monomer and its partial polymer, a thermally conductive filler, the type of other additives, and the thermal conductivity. The amount of filler filled, the film thickness of the cured product, etc. are taken into consideration. Examples of the other polymerization initiators include the thermal polymerization initiators used in the above partial polymerization and the photopolymerization initiators used in the partial polymerization (excluding the triazine peroxide derivative represented by general formula (1)). Can be mentioned.

<Thermal conductive filler>
The thermally conductive filler is not particularly limited, and includes, for example, aluminum oxide, silicon oxide, magnesium oxide, zinc oxide, titanium oxide, zirconium oxide, iron oxide, silicon carbide, boron nitride, aluminum nitride, titanium nitride, silicon nitride, Examples include titanium boride, carbon black, carbon fiber, carbon nanotubes, diamond, nickel, copper, aluminum, titanium, gold, and silver. In order to improve the strength of the sheet, fillers surface-treated with silane, titanate, etc. may be used. Alternatively, a filler whose surface is coated with a waterproof coat, an insulating coat, etc. using ceramics, polymers, etc. may also be used. Among these, those having high thermal conductivity at room temperature are preferred, and the thermal conductivity (W/m·k) at 20° C. is 1 or more, preferably 5 or more, and more preferably 10 or more. The thermally conductive filler may be used alone or in combination of two or more types.

The shape of the thermally conductive filler is regular or irregular, and examples include polygonal, cubic, elliptical, spherical, acicular, flat plate, flake, or a combination thereof. . Further, the particles may be aggregates of a plurality of crystal particles. The shape of the filler is selected depending on the viscosity of the radically polymerizable monomer or its partial polymer and the ease of processing of the final thermally conductive composition after polymerization.

In addition, the average particle size of the thermally conductive filler is preferably 0.5 μm or more and 100 μm or less, and in particular, from the viewpoint of dispersibility and thermal conductivity, small fillers with an average particle size of 1 μm or more and 20 μm or less, and It is preferable to use a large filler with a particle size of 25 μm or more and 100 μm or less.

The amount of the thermally conductive filler is 100 parts by volume or more and 900 parts by volume or less with respect to 100 parts by volume of the binder component containing at least one of a radically polymerizable monomer and a partial polymer thereof, and a photopolymerization initiator. In conventional compositions that are photocured using ultraviolet rays, etc., there is a limit to the content of thermally conductive filler in order to ensure the light transparency necessary for curing, but the thermally conductive composition of the present invention uses a triazine peroxide derivative. Therefore, the thermally conductive filler can be contained in an amount of 100 parts by volume or more with respect to 100 parts by volume of the binder component. The amount of the thermally conductive filler is preferably 200 parts by volume or more, more preferably 300 parts by volume or more, and preferably 700 parts by volume or less, based on 100 parts by volume of the binder component. More preferably, it is 600 parts by volume or less. If the amount of the thermally conductive filler is less than 100 parts by volume with respect to 100 parts by volume of the binder component, sufficient thermal conductivity cannot be imparted, and if it exceeds 900 parts by volume, the strength of the thermally conductive sheet will be weakened.

<Other additives, etc.>
The thermally conductive composition may contain a sensitizer (isopropylthioxanthone, diethylthioxanthone, 4,4'-bis(diethylamino)benzophenone, 9,10-dibutoxyanthracene, 9-phenylacridine, coumarin, ketocoumarin, acridine) as appropriate. orange, camphor quinone, etc.), crosslinking agents, crosslinking accelerators, silane coupling agents, tackifying resins (rosin derivatives, polyterpene resins, petroleum resins, oil-soluble phenols, etc.), anti-aging agents, fillers, colorants (pigments, dyes, etc.), ultraviolet absorbers, antioxidants, chain transfer agents, plasticizers, softeners, surfactants, antistatic agents, thickeners, flame retardants, inorganic compounds, inorganic fillers, electromagnetic wave absorbing fillers, etc. Known additives can be used alone or in combination as long as they do not impair the characteristics of this embodiment. Moreover, various common solvents can also be used when forming the thermally conductive sheet.

The method of mixing the above constituent materials is not particularly limited, but in the case of small quantities, manual mixing is also possible, but it is possible to mix by hand using a universal mixer, planetary mixer, hybrid mixer, Henschel mixer, kneader, ball mill, or mixing method. A common mixer such as a roll is used.

<Thermal conductive sheet>
The thermally conductive sheet of the present invention is a cured product of the thermally conductive composition.

As a method for processing the thermally conductive sheet, conventionally known methods such as a roll coating method, a spin coating method, a dip coating method, a brush coating method, a bar coating method, a knife coating method, a die coating method, a doctor blade method, Various molding methods such as extrusion molding, injection molding, and press molding can be used.

The method for curing the thermally conductive composition is not particularly limited, and it is preferably carried out by irradiation with active energy rays such as electron beams, ultraviolet rays, visible light, and radiation.

The active energy ray preferably has a wavelength of 250 to 450 nm, and more preferably has a wavelength of 350 to 410 nm from the viewpoint of rapid curing. The exposure amount of the active energy rays should be appropriately set depending on the wavelength and intensity of the active energy rays and the composition of the thermally conductive composition. Note that the intensity of the active energy rays is arbitrary; with high intensity, curing can be performed in a short time, and with low intensity, curing can be performed by increasing time.

Examples of the light source for the light irradiation include a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an ultraviolet electrodeless lamp, a light emitting diode (LED), a xenon arc lamp, a carbon arc lamp, sunlight, a YAG laser, etc. A solid laser, a semiconductor laser, a gas laser such as an argon laser, etc. can be used. In addition, when using light from visible light to infrared light, which the triazine peroxide derivative absorbs little, curing can be carried out effectively by using a sensitizer that absorbs the light as the additive. .

In addition, as a manufacturing method of said hardened|cured material, a dual cure process may be applied and the process of heating may be performed before and after the process of irradiating with active energy rays. In the step of heating the thermally conductive composition, examples of heating methods include heating, ventilation heating, and the like. The heating method is not particularly limited, and examples thereof include an oven, a hot plate, infrared irradiation, electromagnetic wave irradiation, and the like. Further, examples of the ventilation heating method include a ventilation drying oven.

The thickness of the thermally conductive sheet is preferably 0.3 mm or more and 5 mm or less. In conventional compositions that are photocured using ultraviolet rays, etc., there is a limit to the film thickness in order to ensure the light transmittance necessary for curing, but since the thermally conductive composition of the present invention contains a triazine peroxide derivative, It can be cured with a film thickness of .3 mm or more and 5 mm or less. The thermally conductive sheet can be produced in a wide range of film thicknesses (for example, film thicknesses of 0.5 mm or more, 0.8 mm or more are examples), and therefore can be applied to various uses. The thermally conductive sheet is usually used as a single layer, but it can also be used as a multilayer of two or more layers, if necessary. Further, the thermal conductivity of the thermally conductive sheet is preferably 1.5 (W/m・K) or more at room temperature (23° C.) in a general environment, and 2.0 (W/m・K). ) or more is more preferable.

The present invention will be explained in more detail with reference to Examples below. The present invention is not limited to these examples.

<Synthesis example 1-7>
(1) Synthesis of triazine peroxide derivative [Synthesis example 1: Synthesis of compound 19]
3.03 g (16.3 mmol) of diphenyl sulfide and 30 mL of dehydrated dichloromethane were added to a 100 mL eggplant flask, and the mixture was cooled to 0°C. After adding 3.00 g (16.3 mmol) of cyanuric chloride to this, 2.39 g (17.9 mmol) of aluminum chloride was added over 10 minutes, and the mixture was reacted at 0° C. for 3 hours. After the reaction was completed, the reaction solution was poured into 50 mL of ice-cold 1M hydrochloric acid, stirred, and the aqueous phase was separated. The oil phase was washed with 50 mL of saturated brine and dehydrated with anhydrous sodium sulfate. After filtration, it was concentrated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (n-hexane/ethyl acetate = 4/1 to 2/1) to obtain 5.03 g (yield 92.6%) of 2,4-dichloro-6-(4- Phenylthio-1-phenyl)-1,3,5-triazine was obtained.

3.00 g (8.98 mmol) of 2,4-dichloro-6-(4-phenylthio-1-phenyl)-1,3,5-triazine and 30 mL of methyl ethyl ketone were added to a 100 mL eggplant flask, and the mixture was heated to 40°C. After adding 4.67 g of ion-exchanged water and 4.31 g (26.9 mmol) of a 25% by mass aqueous sodium hydroxide solution, 0.32 g (9.87 mmol) of methanol was added dropwise over 10 minutes, and the mixture was reacted at 40°C for 2 hours. I let it happen. 1.29 g (9.87 mmol) of a 69% by mass aqueous solution of tert-butyl hydroperoxide was added dropwise over 10 minutes at 40°C or lower, and the mixture was reacted at 40°C for 1 hour. After the reaction was completed, the aqueous phase was separated and the oil phase was poured into 50 mL of ice water. The precipitated crystals were filtered, washed with ion-exchanged water, and dried under reduced pressure to obtain 2.60 g (yield 75.5%) of Compound 19 of the present invention. Table 1 shows the analysis results of the obtained compound 19 by EI-MS and ¹ H-NMR.

[Synthesis Example 2: Synthesis of Compound 25]
Compound 25 of the present invention was synthesized according to the method described in Synthesis Example 1, except that the diphenyl sulfide described in Synthesis Example 1 was changed to 1-methoxynaphthalene. Table 1 shows the analysis results of the obtained compound 25 by EI-MS and ¹ H-NMR.

[Synthesis Example 3: Synthesis of Compound 35]
0.44 g (17.1 mmol) of magnesium, 15 mL of dehydrated tetrahydrofuran, and a catalytic amount of iodine were placed in a heat-dried 100 mL three-necked flask, and the mixture was stirred at room temperature. A mixed solution of 4.29 g (16.3 mmol) of 4-bromo-4'-methoxybiphenyl and 15 mL of dehydrated tetrahydrofuran was added dropwise, and the mixture was stirred under reflux for 1 hour. 3.00 g (16.3 mmol) of cyanuric chloride and 15 mL of dehydrated tetrahydrofuran were added to another 100 mL three-necked flask, and the mixture was cooled to 0°C. The previously prepared mixed solution was added dropwise thereto over 30 minutes, the temperature was raised to room temperature, and the mixture was stirred for 15 hours. The reaction solution was cooled in an ice bath, 1M hydrochloric acid was added and stirred, and the pH was adjusted to 8 with saturated aqueous sodium hydrogen carbonate solution. Then, it was extracted with ethyl acetate. The oil phase was washed once with saturated brine and then dehydrated with magnesium sulfate. After filtration, the oil phase was concentrated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (n-hexane/ethyl acetate = 3/1 to 1/1) to obtain 2.07 g (yield 38.2%) of 2,4-dichloro-6-[4- (4'-methoxybiphenyl)]-1,3,5-triazine was obtained.

Add 1.20 g (3.62 mmol) of 2,4-dichloro-6-[4-(4'-methoxybiphenyl)]-1,3,5-triazine and 10 mL of methyl ethyl ketone to a 50 mL eggplant flask, and heat to 40°C. did. After adding 1.88 g of ion-exchanged water and 1.74 g (10.9 mmol) of a 25% by mass aqueous sodium hydroxide solution, 0.13 g (3.98 mmol) of methanol was added dropwise over 5 minutes and reacted at 40°C for 2 hours. I let it happen. At 40°C or lower, 0.52 g (3.98 mmol) of a 69% by mass aqueous solution of tert-butyl hydroperoxide was added dropwise over 5 minutes, and the mixture was reacted at 40°C for 1 hour. After the reaction was completed, the aqueous phase was separated and the oil phase was poured into 50 mL of ice water. The precipitated crystals were filtered, washed with ion-exchanged water, and dried under reduced pressure to obtain 1.04 g (yield 75.0%) of Compound 35 of the present invention. Table 1 shows the analysis results of the obtained compound 35 by EI-MS and ¹ H-NMR.

[Synthesis Example 4: Synthesis of Compound 53]
Compound 53 of the present invention was prepared in the same manner as in Synthesis Example 3, except that the methanol described in Synthesis Example 3 was changed to isopropyl alcohol, and the 69% by mass tert-butyl hydroperoxide aqueous solution was changed to 90% by mass tert-hexyl hydroperoxide solution. It was synthesized according to the method described. Table 1 shows the analysis results of the obtained compound 53 by EI-MS and ¹ H-NMR.

[Synthesis Example 5: Synthesis of Compound 56]
Compound 6 of the present invention was prepared in the same manner as in Synthesis Example 3, except that the methanol described in Synthesis Example 3 was changed to tert-butyl alcohol, and the 69% by mass aqueous tert-butyl hydroperoxide solution was changed to 80% by mass cumene hydroperoxide solution. It was synthesized according to the method described. Table 1 shows the analysis results of the obtained compound 56 by EI-MS and ¹ H-NMR.

[Synthesis Example 6: Synthesis of Compound 77]
0.44 g (17.1 mmol) of magnesium, 15 mL of dehydrated tetrahydrofuran, and a catalytic amount of iodine were placed in a heat-dried 100 mL three-necked flask, and the mixture was stirred at room temperature. A mixed solution of 4.29 g (16.3 mmol) of 4-bromo-4'-methoxybiphenyl and 15 mL of dehydrated tetrahydrofuran was added dropwise, and the mixture was stirred under reflux for 1 hour. 3.00 g (16.3 mmol) of cyanuric chloride and 15 mL of dehydrated tetrahydrofuran were added to another 100 mL three-necked flask, and the mixture was cooled to 0°C. The previously prepared mixed solution was added dropwise thereto over 30 minutes, the temperature was raised to room temperature, and the mixture was stirred for 15 hours. The reaction solution was cooled in an ice bath, 1M hydrochloric acid was added and stirred, and the pH was adjusted to 8 with saturated aqueous sodium hydrogen carbonate solution. Then, it was extracted with ethyl acetate. The oil phase was washed once with saturated brine and then dehydrated with magnesium sulfate. After filtration, the oil phase was concentrated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (n-hexane/ethyl acetate = 3/1 to 1/1) to obtain 2.07 g (yield 38.2%) of 2,4-dichloro-6-[4- (4'-methoxybiphenyl)]-1,3,5-triazine was obtained.

3.03 g (16.3 mmol) of anisole and 30 mL of dehydrated dichloromethane were added to a 100 mL eggplant flask, and the mixture was cooled to 0°C. After adding 3.00 g (16.3 mmol) of 2,4-dichloro-6-[4-(4'-methoxybiphenyl)]-1,3,5-triazine, 2.39 g (17 mmol) of aluminum chloride .9 mmol) was added over 10 minutes, and the mixture was reacted at 0° C. for 3 hours. After the reaction was completed, the reaction solution was poured into 50 mL of ice-cold 1M hydrochloric acid, stirred, and the aqueous phase was separated. The oil phase was washed with 50 mL of saturated brine and dehydrated with anhydrous sodium sulfate. After filtration, it was concentrated under reduced pressure to obtain a crude product. The crude product was purified by silica gel column chromatography (n-hexane/ethyl acetate = 4/1 to 2/1) to obtain 5.03 g (yield 92.6%) of 2-chloro-4-(4-methoxyphenyl). )-6-[4-(4'-methoxybiphenyl)]-1,3,5-triazine was obtained.

Add 1.88 g of ion-exchanged water and 1.74 g (10.9 mmol) of a 25% by mass aqueous sodium hydroxide solution to a 50 mL eggplant flask, and add 0.52 g (3.98 mmol) of a 69% by mass tert-butyl hydroperoxide aqueous solution at 30°C or lower. was added gradually. Here, 1.20 g (3.62 mmol) of 2-chloro-4-(4-methoxyphenyl)-6-[4-(4'-methoxybiphenyl)]-1,3,5-triazine and 10 mL of tetrahydrofuran were mixed. The solution was added dropwise at 10°C over 10 minutes and reacted at 20°C for 3 hours. After the reaction was completed, 10 mL of dichloromethane was added and the aqueous phase was separated. The oil phase was washed with ion-exchanged water and dried over anhydrous magnesium sulfate at 0°C. After filtration, the oil phase was concentrated under reduced pressure to obtain 1.04 g (yield 75.0%) of Compound 77 of the present invention. Table 1 shows the analysis results of the obtained compound 77 by EI-MS and ¹ H-NMR.

<Example 1>
<Preparation of partial polymer>
0.5 parts by mass of Compound 19 as a photopolymerization initiator was mixed with 100 parts by mass of 2-ethylhexyl acrylate (2-EHA), and irradiated with ultraviolet rays to polymerize 10 to 20% of the total monomer amount. A thickened partial polymer was obtained.

<Preparation of thermally conductive composition>
85 parts by mass of the partial polymer of 2-ethylhexyl acrylate (2-EHA) obtained above, 15 parts by mass of isobornyl acrylate (IBXA), and 0.0 parts of 1,6-hexanediol diacrylate (HDDA). Thermal conductive filler 1 (alumina: average particle size 50 μm, thermal conductivity at 20°C 25 W/m・k) and 80 volume parts of thermally conductive filler 2 (alumina: average particle size 2 μm, thermal conductivity 25 W/m・k at 20°C) were mixed, and the mixture was mixed with a rotation-revolution mixer (THINKY). A thermally conductive composition was obtained by stirring for 2 minutes using Awatori Rentaro ARV-310 (manufactured by Awatori Rentaro Co., Ltd.).

<Manufacture of thermally conductive sheet>
The thermally conductive composition obtained above was sandwiched between the release-treated surfaces of two polyethylene terephthalate films, each of which had been subjected to a release treatment, using a spacer. Thereafter, ultraviolet irradiation (illuminance 2000 mW/cm ² ) was performed for 10 seconds from one side of the two release films using a 365 nm LED light source to cure the thermally conductive composition and produce a thermally conductive sheet.

<Example 2>
A thermally conductive sheet was produced in the same manner as in Example 1, except that Compound 25 was used instead of Compound 19 as a photopolymerization initiator in the preparation of the partial polymer and the thermally conductive composition.

<Example 3>
A thermally conductive sheet was prepared in the same manner as in Example 2, except that a monomer of 2-ethylhexyl acrylate (2-EHA) was used instead of the partial polymer of 2-ethylhexyl acrylate (2-EHA) as the radically polymerizable compound. was manufactured.

<Example 4>
A thermally conductive sheet was produced in the same manner as in Example 1, except that Compound 35 was used instead of Compound 19 as a photopolymerization initiator in the preparation of the partial polymer and the thermally conductive composition.

<Example 5>
Heat was applied in the same manner as in Example 4, except that the amount of thermally conductive filler 1 was changed to 150 parts by volume and the amount of thermally conductive filler 2 was changed to 50 parts by volume with respect to 100 parts by volume of the binder component. A conductive sheet was manufactured.

<Example 6>
A thermally conductive sheet was produced in the same manner as in Example 1, except that Compound 53 was used instead of Compound 19 as a photopolymerization initiator in the preparation of the partial polymer and the thermally conductive composition.

<Example 7>
A thermally conductive sheet was produced in the same manner as in Example 6, except that the film thickness after curing of the thermally conductive sheet was changed to the film thickness listed in Table 1, and ultraviolet irradiation was performed for 60 seconds.

<Example 8>
A thermally conductive sheet was produced in the same manner as in Example 1, except that Compound 56 was used instead of Compound 19 as a photopolymerization initiator in the preparation of the partial polymer and the thermally conductive composition.

<Example 9>
Heat treatment was carried out in the same manner as in Example 8, except that the amount of thermally conductive filler 1 was changed to 400 parts by volume and the amount of thermally conductive filler 2 was changed to 150 parts by volume with respect to 100 parts by volume of the binder component. A conductive sheet was manufactured.

<Example 10>
A thermally conductive sheet was produced in the same manner as in Example 1, except that Compound 77 was used instead of Compound 19 as a photopolymerization initiator in the preparation of the partial polymer and the thermally conductive composition.

<Comparative example 1>
In the production of the partial polymer and the preparation of the thermally conductive composition, Compound R1 (2,4,6-trimethylbenzoyldiphenylphosphine oxide: manufactured by IGM RESINS B.V.) was used instead of Compound 19 as a photopolymerization initiator. A thermally conductive sheet was produced in the same manner as in Example 1, except that 4 parts by mass of compound R1 was mixed with 100 parts by mass of 2-ethylhexyl acrylate (2-EHA) in the production of the partial polymer. did.

<Comparative example 2>
Thermal conduction was carried out in the same manner as in Example 1, except that the mixed amount of thermally conductive filler 1 was changed to 30 parts by volume and the mixed amount of thermally conductive filler 2 was changed to 15 parts by volume with respect to 100 parts by volume of the binder component. A plastic sheet was manufactured.

<Comparative example 3>
Thermal conduction was carried out in the same manner as in Example 10, except that the mixed amount of thermally conductive filler 1 was changed to 800 parts by volume and the mixed amount of thermally conductive filler 2 was changed to 300 parts by volume with respect to 100 parts by volume of the binder component. A plastic sheet was manufactured.

<Comparative example 4>
In the preparation of the thermally conductive composition, a thermal polymerization initiator, compound R2 (lauroyl peroxide "Perloyl L" manufactured by NOF Corporation) was used instead of compound R1 as a polymerization initiator, and instead of irradiating ultraviolet rays. A thermally conductive sheet was produced in the same manner as in Comparative Example 1 except that the sheet was heated at 150° C. for 600 seconds.

<Comparative example 5>
A thermally conductive sheet was produced in the same manner as Comparative Example 4 except that the sheet was heated at 150° C. for 900 seconds.

<Curability>
When peeling off the release film of the thermally conductive sheets obtained in Examples and Comparative Examples, the interface between the thermally conductive sheet and the release film was visually observed.
○: The release film can be peeled off smoothly, and the thermally conductive sheet is not damaged.
×: The release film cannot be peeled off, or the thermally conductive sheet is damaged.

<Film thickness>
The film thickness of the thermally conductive sheets obtained in Examples and Comparative Examples was measured using a digital micrometer.

<Thermal conductivity>
Thermal conductivity of the thermally conductive sheets obtained in Examples and Comparative Examples was measured using a thermal conductivity meter (QTM-710: manufactured by Kyoto Electronics Industry Co., Ltd.).

In Examples 1 to 10, thermally conductive sheets having high thermal conductivity and a thick film were obtained.

Comparative Example 1 had poor curability because it used a photopolymerization initiator that was not a triazine peroxide derivative. Comparative Example 2 had poor thermal conductivity due to the low content of thermally conductive filler. Comparative Example 3 had poor curability because the content of the thermally conductive filler was too large. Since Comparative Examples 4 and 5 used a thermal polymerization initiator (compound R2), they could not be cured even after 600 seconds, and it took 900 seconds to cure.

Claims (3)

a binder component containing at least one of a radically polymerizable monomer and a partial polymer thereof, and a photopolymerization initiator;
A thermally conductive composition containing a thermally conductive filler,
The amount of the thermally conductive filler is 100 parts by volume or more and 900 parts by volume or less with respect to 100 parts by volume of the binder component,
A thermally conductive composition, wherein the photopolymerization initiator is a triazine peroxide derivative represented by the following general formula (1).
((In general formula (1), R ¹ and R ² are independently a methyl group or an ethyl group, R ³ is an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or a carbon number that may have an alkyl group. represents an aromatic hydrocarbon group having 6 to 9 carbon atoms, R ⁴ is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, and an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms; , an optionally substituted heterocyclic group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, -Y-R, or -N-RR', where Y is Represents an oxygen atom or a sulfur atom, R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, and an optionally substituted aromatic group having 6 to 20 carbon atoms. represents a group hydrocarbon group, an optionally substituted heterocyclic group having 2 to 20 carbon atoms.Ar is an aryl group represented by the following general formula (2): Ar ¹ , Ar ² , or Ar ³ .)
(In general formula (2), m represents an integer from 0 to 3, R ⁵ is an independent substituent, and is an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms, an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, an optionally substituted heterocyclic group having 2 to 20 carbon atoms, an optionally substituted acyl group having 1 to 20 carbon atoms, -Y- R or -N-RR', Y represents an oxygen atom or a sulfur atom, R and R' are independently a hydrogen atom, an optionally substituted aliphatic hydrocarbon group having 1 to 20 carbon atoms; , an optionally substituted aromatic hydrocarbon group having 6 to 20 carbon atoms, and an optionally substituted heterocyclic group having 2 to 20 carbon atoms.) A thermally conductive sheet comprising a cured product of the thermally conductive composition according to claim 1. The thermally conductive sheet according to claim 2, having a thickness of 0.3 mm or more and 5 mm or less.