TW202202441A - Method for producing modifided boron nitride particle, modifided boron nitride particle, composition for forming thermal conductive material, thermal conductive material, thermal conductive sheet, device with thermal conductive layer - Google Patents

Abstract

The present invention provides a method for producing modified boron nitride particles that can be used for the production of a heat conductive material which has excellent heat conductivity and excellent peel strength. The present invention also provides: modified boron nitride particles; a composition for forming a heat conductive material; a heat conductive material; a heat conductive sheet; and a device with a heat conductive layer. A method for producing modified boron nitride particles according to the present invention comprises a modification step wherein boron nitride particles and an oxidant are brought into contact with each other in an aqueous solution that has a pH of 12 or more, thereby obtaining modified boron nitride particles.

Description

Method for producing modified boron nitride particles, modified boron nitride particles, composition for forming thermally conductive material, thermally conductive material, thermally conductive sheet, and element with thermally conductive layer

The present invention relates to a method for producing modified boron nitride particles, modified boron nitride particles, a composition for forming a thermally conductive material, a thermally conductive material, a thermally conductive sheet, and an element with a thermally conductive layer.

In recent years, the miniaturization of power semiconductor elements used in various electronic devices such as personal computers, general household appliances, and automobiles has progressed rapidly. With the miniaturization, it is difficult to control the heat generated from the densified power semiconductor element. In order to deal with such a problem, a thermally conductive material that promotes heat dissipation from the power semiconductor element can be used. In addition, boron nitride particles are sometimes used in order to improve the thermal conductivity of such a thermally conductive material. For example, Patent Document 1 discloses a filler obtained by heating boron nitride under predetermined conditions.

[Patent Document 1] Japanese Patent No. 3468615

The inventors of the present invention have studied the thermally conductive material using the filler described in Patent Document 1, and as a result, have found that there is room for improvement in thermal conductivity. In addition, when the thermally conductive material is bonded to an object (adhesive material) that transfers heat, a sufficiently high peel strength is also required. The thermally conductive material using the filler described in Patent Document 1 also has room for improvement in the above-described peel strength.

Therefore, the subject of this invention is to provide the manufacturing method of the modified boron nitride particle which can be used for manufacture of the thermally conductive material excellent in thermal conductivity and peeling strength. Moreover, the subject of this invention is to provide the element with which the modified boron nitride particle, the composition for thermally conductive material formation, the thermally conductive material, the thermally conductive sheet, and the thermally conductive layer are provided.

The inventors of the present invention have conducted intensive studies in order to solve the above-mentioned problems, and as a result, have found that the above-mentioned problems can be solved by the following structures.

[1] A method for producing modified boron nitride particles, comprising a reforming step of contacting boron nitride particles with an oxidizing agent in an aqueous solution of pH 12 or higher to obtain modified boron nitride particles. [2] The method for producing modified boron nitride particles according to [1], wherein the pH of the aqueous solution exceeds 13. [3] The method for producing modified boron nitride particles according to [1] or [2], wherein the standard redox potential of the oxidizing agent is 1.50V or more. [4] The method for producing modified boron nitride particles according to any one of [1] to [3], wherein the oxidizing agent is a persulfate. [5] The method for producing modified boron nitride particles according to any one of [1] to [4], wherein the change rate of the median diameter obtained from the following formula is less than 10%. Formula: Change rate of median diameter (%)=[1-(median diameter of modified boron nitride particles produced)/(median of boron nitride particles used in the production of modified boron nitride particles) value diameter)] × 100 [6] The method for producing modified boron nitride particles according to any one of [1] to [5], which comprises an adsorption step in which the adsorption step is carried out in water and an organic solvent. In the presence of at least one, the modified boron nitride particles obtained in the modification step are brought into contact with a surface modifier to obtain modified boron nitride particles modified with the surface modifier. [7] A modified boron nitride particle, wherein the oxygen atomic concentration on the surface detected by X-ray photoelectron spectroscopy exceeds 5.0 atom%, and the contact angle with water is 90° or less, and is represented by the following formula: (1) The obtained D value is 0.010 or less. Formula (1): D value=B(OH) ₃ (002)/BN(002) B(OH) ₃ (002): derived from hydrogen with triclinic space group measured by X-ray diffraction Peak intensity of (002) plane of boron oxide BN(002): peak intensity from (002) plane of boron nitride with hexagonal space group measured by X-ray diffraction [8] as in [7 ] The modified boron nitride particles, wherein the carbon atom concentration on the surface detected by X-ray photoelectron spectroscopy analysis exceeds 3.0 atom%. [9] The modified boron nitride particles according to [8], wherein the carbon atom concentration is 6.0 atomic % or more. [10] The modified boron nitride particles according to any one of [7] to [9], wherein the D value is 0.007 or less. [11] The modified boron nitride particles according to any one of [7] to [10], which are aggregated particles. [12] The modified boron nitride particles according to [11], wherein the compressive fracture strength is 5.0 MPa or less. [13] The modified boron nitride particles according to any one of [7] to [12], wherein the median diameter is 10 μm or more. [14] A composition for forming a thermally conductive material, comprising: modified boron nitride particles obtained by the method for producing modified boron nitride particles according to any one of [1] to [6], and A modified boron nitride particle that is any one of the modified boron nitride particles described in any one of [7] to [13]; and a resin binder or a precursor thereof. [15] The composition for forming a thermally conductive material according to [14], wherein the resin binder or its precursor contains an epoxy compound. [16] The composition for forming a thermally conductive material according to [14] or [15], wherein the resin binder or its precursor contains an epoxy compound and a phenol compound. [17] The composition for forming a thermally conductive material according to any one of [14] to [16], further comprising a hardening accelerator. [18] The composition for forming a thermally conductive material according to [17], wherein the hardening accelerator includes a compound containing a phosphorus atom. [19] The composition for forming a thermally conductive material according to [17] or [18], wherein the hardening accelerator contains a phosphonium salt. [20] A thermally conductive material obtained by curing the thermally conductive material-forming composition according to any one of [14] to [19]. [21] A thermally conductive sheet formed of the thermally conductive material described in [20]. [22] An element with a thermally conductive layer, comprising an element and a thermally conductive layer disposed on the element and comprising the thermally conductive sheet described in [21]. [Inventive effect]

According to the present invention, it is possible to provide a method for producing modified boron nitride particles that can be used to produce a thermally conductive material having excellent thermal conductivity and peel strength. Furthermore, it is possible to provide modified boron nitride particles, a composition for forming a thermally conductive material, a thermally conductive material, a thermally conductive sheet, and an element with a thermally conductive layer.

Hereinafter, the boron nitride particles and the composition for forming a thermally conductive material of the present invention will be described in detail. The description of the constituent requirements described below is sometimes based on a representative embodiment of the present invention, but the present invention is not limited to this embodiment. In addition, in this specification, the numerical range represented using "-" means the range which includes the numerical value described before and after "-" as a lower limit and an upper limit.

In this specification, in the case of referring to the value of a matter whose value may vary with temperature (eg, standard redox potential, pH, etc.), unless otherwise specified, the value represents the value at 25°C. For example, in the case of reciting the capacity of water, unless otherwise stated, the capacity means the capacity at 25°C. In this specification, "pH" is pH measured by a method based on JIS Z8802-1984 using a known pH meter. The measurement temperature of pH was set to 25 degreeC. In this specification, unless otherwise stated, "room temperature" is 25°C.

In this specification, the description of a "(meth)acryloyl group" means "either or both of an acryl group and a methacryloyl group". In addition, the description of "(meth)acrylamido group" means "either or both of an acrylamino group and a methacrylamido group".

In this specification, the acid anhydride group may be a monovalent group or a divalent group. In addition, when the acid anhydride group represents a monovalent group, acid anhydrides such as maleic anhydride, phthalic anhydride, pyromic acid dianhydride, and trimellitic anhydride can be exemplified. Substituents obtained by removing arbitrary hydrogen atoms. Moreover, when an acid anhydride group represents a divalent group, it represents a group represented by *-CO-O-CO-* (* represents a bonding position).

In addition, in this specification, regarding the substituent group which is not clearly described as substituted or unsubstituted, if possible, the group may have a substituent within the range that does not impair the intended effect (for example, described later). the substituent group Y). For example, the notation of "alkyl" refers to a substituted or unsubstituted alkyl group (an alkyl group that may have a substituent) within the scope of not impairing the intended effect. In addition, in this specification, when "it may have a substituent", the kind of a substituent, the position of a substituent, and the number of a substituent are not specifically limited. As the number of substituents, for example, one or two or more can be mentioned. Examples of the substituent include a non-metallic atomic group having a valence other than a hydrogen atom, and a group selected from the following substituent group Y is preferable. In this specification, as a halogen atom, a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom are mentioned, for example.

Substituent group Y: halogen atom (-F, -Br, -Cl, -I, etc.), hydroxyl, amine group, carboxylic acid group and its conjugated base, carboxylic acid anhydride group, cyanate ester group, unsaturated polymer group, epoxy group, oxetanyl group, aziridine group, thiol group, isocyanate group, thioisocyanate group, aldehyde group, alkoxy group, aryloxy group, alkylthio group, arylthio group, alkane dithio, aryl dithio, N-alkylamine, N,N-dialkylamine, N-arylamine, N,N-diarylamine, N-alkyl- N-Arylamino, Ethyloxy, Aminocarboxy, N-Alkylaminecarboxy, N-Arylaminecarboxy, N,N-Dialkylaminecarboxy, N,N-Diarylamine carboxyloxy, N-alkyl-N-arylamine carboxyloxy, alkylthiooxy, arylthiooxy, thiothio, amide, N- Alkyl amide group, N-aryl amide group, urea group, N'-alkyl urea group, N',N'-dialkyl urea group, N'-aryl urea group, N',N' -Diarylureido, N'-Alkyl-N'-Arylureido, N-Alkylureido, N-Arylureido, N'-Alkyl-N-Alkylureido, N' -Alkyl-N-arylureido, N',N'-dialkyl-N-alkylureido, N',N'-dialkyl-N-arylureido, N'-aryl -N-alkylureido, N'-aryl-N-arylureido, N',N'-diaryl-N-alkylureido, N',N'-diaryl-N- Arylureido, N'-Alkyl-N'-Aryl-N-Alkylureido, N'-Alkyl-N'-Aryl-N-Arylureido, Alkoxycarbonylamine, Aryloxycarbonylamino, N-alkyl-N-alkoxycarbonylamino, N-alkyl-N-aryloxycarbonylamino, N-aryl-N-alkoxycarbonylamino, N -Aryl-N-aryloxycarbonylamino, carboxyl, carboxyl, alkoxycarbonyl, aryloxycarbonyl, carboxyl, N-alkylamine carboxyl, N,N-dioxane Aminocarbamoyl, N-Arylcarbamoyl, N,N-Diarylcarbamoyl, N-Alkyl-N-Arylcarbamoyl, Alkylsulfinyl, Aryl Sulfinyl group, alkylsulfonyl group, arylsulfonyl group, sulfonic acid group (-SO ₃ H) and its conjugated base, alkoxysulfonyl group, aryloxysulfonyl group, amine sulfinyl group Sulfonyl, N-alkylaminesulfinyl, N,N-dialkylaminesulfinyl, N-arylaminesulfinyl, N,N-diarylaminesulfinyl, N -Alkyl-N-arylaminesulfinyl, sulfamoyl, N-alkylaminesulfinyl, N,N-dialkylaminesulfinyl, N-arylsulfamoyl, N , N-diaryl sulfamoyl, N-alkyl-N-aryl sulfamoyl, N- aryl sulfamoyl and its conjugated base, N-alkyl sulfamoyl sulfa bases (-SO ₂ NHSO ₂ (alkyl)) and their conjugated bases, N-arylsulfonamidosulfonamides (-SO ₂ NHSO ₂ (aryl)) and their conjugated bases, N- Alkylsulfonamidocarboxy (-CONHSO ₂ (alkyl)) and its conjugated bases, N-arylsulfonamidocarboxy (-CONHSO ₂ (aryl) )) and their conjugated bases, alkoxysilyl (-Si(alkoxy) ₃ ), aryloxysilyl (-Si(aryloxy) ₃ ), hydroxysilyl (-Si (OH) ₃ ) and its conjugated bases, phosphine groups (-PO ₃ H ₂ ) and its conjugated bases, dialkylphosphoranyl groups (-PO ₃ (alkyl) ₂ ), diarylphosphines Acyl (-PO ₃ (aryl) ₂ ), alkylaryl phosphinoyl (-PO ₃ (alkyl) (aryl)), monoalkyl phosphino (-PO ₃ H (alkyl)) and its conjugated bases, monoaryl phosphinoids (-PO ₃ H (aryl)) and their conjugated bases, phosphinoyloxy (-OPO ₃ H ₂ ) and their conjugated bases, dioxane phosphinodonoxy (-OPO ₃ (alkyl) ₂ ), diarylphosphinodonyloxy (-OPO ₃ (aryl) ₂ ), alkylaryl phosphinoyloxy (-OPO ₃ (alkyl) (aryl)), monoalkyl phosphinoyloxy (-OPO ₃ H(alkyl)) and its conjugated bases, monoaryl phosphinoyloxy (-OPO ₃ H(aryl)) and its conjugates Conjugated base, cyano, nitro, aryl, alkenyl, alkynyl and alkyl. In addition, if possible, each of the above-mentioned groups may further have a substituent (for example, one or more of the above-mentioned groups). For example, an aryl group which may have a substituent is also included as a group that can be selected from the substituent group Y. When the group selected from the substituent group Y has a carbon atom, the number of carbon atoms which the above-mentioned group has is, for example, 1 to 20. The number of atoms other than hydrogen atoms contained in the group selected from the substituent group Y is, for example, 1 to 30. Also, if possible, these substituents may or may not be formed by bonding substituents to each other or to a substituted group to form a ring. For example, an alkyl group (or, such as an alkoxy group, an alkyl moiety in a group comprising an alkyl group as a partial structure) may be a cyclic alkyl group (cycloalkyl), or may have one or more cyclic The structure is an alkyl group as part of the structure.

[Method for producing modified boron nitride particles] The method for producing modified boron nitride particles in the present invention (hereinafter, also referred to as "the method of the present invention") includes a reforming step in which boron nitride particles are brought into contact with an oxidizing agent in an aqueous solution having a pH of 12 or higher. Modified boron nitride particles are obtained. The mechanism by which the problem of the present invention can be solved by adopting such a configuration is not clear, but the inventors of the present invention conjecture as follows. Although boron nitride particles are excellent in thermal conductivity, they generally have insufficient adhesiveness with resin binders. Therefore, in a thermally conductive material comprising ordinary boron nitride particles and a resin binder, due to insufficient adhesion between the resin binder and the boron nitride particles, the thermally conductive material itself is prone to fracture (agglomeration failure), and it is difficult to achieve the desired result. desired peel strength. In order to solve such a problem, an attempt has been made to modify the surface of boron nitride particles by introducing functional groups or the like, but boron nitride is a stable substance, so it is difficult to modify sufficiently. On the contrary, it has been found that when the boron nitride particles are heated in an oxidizing atmosphere for sufficient modification, boron hydroxide is formed on the surface of the boron nitride particles, and this boron hydroxide conversely Various properties such as thermal conductivity of boron nitride particles may be adversely affected. On the other hand, according to the method of the present invention, the boron nitride particles are brought into contact with the oxidizing agent in a predetermined high pH aqueous solution, and the boron hydroxide particles can be prevented from being included in the modified boron nitride particles. , and can fully modify the surface. This is considered to be because the lone electron pair of boron nitride is less likely to be protonated in a predetermined high pH aqueous solution, and the oxidizing agent can function efficiently. As a result, it is considered that since the modified boron nitride particles produced by the method of the present invention have sufficient functional groups introduced on the surface, they have good affinity with the resin binder forming the thermally conductive material, and are less likely to cause cohesion failure of the thermally conductive material. , thereby improving the peel strength of thermally conductive materials. In addition, the said functional group is presumed to be a hydroxyl group. Furthermore, since the modified boron nitride particles produced by the method of the present invention hardly contain boron hydroxide, the thermal conductivity is not deteriorated, and since the affinity with the resin binder is good as described above, it is considered that it is suitable for use in thermally conductive materials. The heat transfer in the medium can also be smoothed, and the thermal conductivity of the thermally conductive material using the modified boron nitride particles produced by the method of the present invention can also be improved. Hereinafter, the case where the thermally conductive material using the modified boron nitride particles is more excellent in peel strength and/or thermal conductivity is also referred to as more excellent effects of the present invention.

〔Production method〕 The production method of the present invention includes at least a reforming step. It is also preferred that the method of the present invention further comprises an adsorption step.

<Modification step> The reforming step is a step of contacting boron nitride particles with an oxidizing agent in an aqueous solution of pH 12 or higher to obtain reformed boron nitride particles. The pH of the above-mentioned aqueous solution is 12 or more means that the pH of the above-mentioned aqueous solution in a state containing the above-mentioned boron nitride and the above-mentioned oxidizing agent is 12 or more. That is, the above-mentioned aqueous solution contains at least water, boron nitride particles, and an oxidizing agent. The pH of the above-mentioned aqueous solution is 12 or more, preferably more than 12, more preferably 13 or more, and even more preferably more than 13. The upper limit of the pH of the above-mentioned aqueous solution is not limited, and is, for example, 14.

The time for contacting the boron nitride particles with the oxidizing agent in the aqueous solution is preferably 0.1 to 24 hours, more preferably 0.5 to 10 hours, and even more preferably 1.5 to 6 hours. In addition, the temperature of the aqueous solution when the boron nitride particles are brought into contact with the oxidizing agent is preferably 1 to 95°C, more preferably 25 to 80°C, and even more preferably 45 to 65°C.

The method for bringing the boron nitride particles into contact with the oxidizing agent in the above-mentioned aqueous solution is not limited. A method of mixing and contacting during processing in a pulverizer or crusher such as a conditioner, a method of contacting with a mechanical stirrer such as a Sany motor or a magnetic stirrer, etc. while stirring treatment, and a pump containing oxidant A method in which an aqueous solution of an oxidant such as this is circulated in a box filled with boron nitride particles while being brought into contact. Furthermore, in the above-mentioned method of contacting while circulating, even if a part of the above-mentioned oxidant aqueous solution is in contact with the boron nitride particles filled in the above-mentioned box, and the other part of the above-mentioned oxidant aqueous solution exists in a pump or the like without contact with nitrogen. The boron nitride particles are in contact, and all the boron nitride particles and the oxidant aqueous solution supplied to the reforming step are also regarded as the above-mentioned aqueous solution as a whole. Among them, a method in which the boron nitride particles or the modified boron nitride particles are not destroyed as much as possible in the above-mentioned aqueous solution is preferable. The destruction referred to here includes, for example, the case where the aggregated form of the aggregated particles is destroyed.

After the boron nitride particles are brought into contact with the oxidizing agent in the aqueous solution, the obtained modified boron nitride particles are preferably extracted from the aqueous solution. The method of extracting the modified boron nitride particles from the above-mentioned aqueous solution is not limited, and, for example, a method of filtering the above-mentioned aqueous solution and extracting the modified boron nitride particles as a filtrate is exemplified. It is also preferable to wash the extracted modified boron nitride particles with water and/or an organic solvent.

(Boron Nitride Particles) The above-mentioned aqueous solution contains boron nitride particles. The boron nitride particles described above may be particles substantially including boron nitride (BN). For example, the content of boron nitride in the boron nitride particles is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more, based on the total mass of the boron nitride particles. The upper limit of the content is not particularly limited, but is, for example, 100% by mass or less.

The crystal structure of the boron nitride particles is not limited, and for example, hexagonal boron nitride or cubic boron nitride can be used. In addition, the boron nitride particles may be, for example, boron nitride nanosheets or boron nitride nanotubes. The shape of the boron nitride particles is not particularly limited, and may be any of a scale shape, a flat shape, a rice grain shape, a spherical shape, a cubic shape, a spindle shape, and an irregular shape. In addition, the boron nitride particles may be aggregated particles (secondary particles) formed by aggregating fine particles of these shapes. As a whole, the aggregated particles may be spherical or irregular, for example. Among them, from the viewpoint of improving the thermal conductivity at the time of compounding with the resin, the boron nitride particles are preferably aggregated particles.

The size of the boron nitride particles (when the boron nitride particles are secondary particles, the size of the secondary particles) is not particularly limited. Among them, from the viewpoint of more excellent dispersibility of the boron nitride particles, the median diameter of the boron nitride particles is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less. The lower limit of the median diameter is not particularly limited, but from the viewpoint of handleability and/or thermal conductivity, 500 nm or more is preferable, 10 μm or more is more preferable, and 15 μm or more is further more preferable. In this specification, the median diameter of particles (the above-mentioned boron nitride particles, modified boron nitride particles, etc.) is, for example, a median diameter that can be measured using Master sizer 2000 manufactured by Malvern Panalytical Ltd.

The compressive fracture strength of the boron nitride particles (especially the boron nitride particles that are aggregated particles) is preferably 10.0 MPa or less, more preferably 5.0 MPa or less, and even more preferably 4.0 MPa or less. In addition, the lower limit of the compressive rupture strength is not limited. For example, the compressive rupture strength is preferably 0.5 MPa or more, more preferably 1.0 MPa or more, and even more preferably 1.5 MPa or more. In this specification, the compressive rupture strength of particles is determined by performing a compression test using a micro-compression tester MCT-510 manufactured by Shimadzu Corporation, and measuring the compressive rupture strength of particles as a sample. The compression test can be carried out as follows: a graph showing the test force (mN)-displacement (μm) at the time of failure of the sample when a load is applied to the sample with an indenter, and the test force (mN) at which the displacement becomes constant is set as the failure point P, and the breaking strength (MPa) was calculated from the following formula. Compressive breaking strength (MPa)=(2.48P)/(3.14d ² ) d: The particle size measurement conditions are set as follows: indenter=FLAT120, test force=20(mN), load speed=0.4462(mN/sec), Load hold time = 5 (sec). Ten arbitrary particles (preferably aggregated particles) are selected, the compressive fracture strength is measured, the average value thereof is obtained, and this is set as the compressive fracture strength of the entire particle. In addition, the said particle diameter (d) is calculated|required by measuring the length of the long axis of a particle (preferably agglomerated particle) from a SEM observation image.

In the above aqueous solution, the content of boron nitride particles is not limited. For example, relative to 100 parts by mass of water in the above aqueous solution, it is preferably 0.1 to 100 parts by mass, more preferably 1 to 30 parts by mass, and 3 to 20 parts by mass. for further better. One type of boron nitride particles may be used alone, or two or more types may be used.

(water) The above-mentioned aqueous solution contains water. In the above aqueous solution, the content of water is preferably 20 to 99% by mass, more preferably 50 to 95% by mass, and even more preferably 65 to 90% by mass relative to the total mass of the above aqueous solution.

(Oxidant) The above-mentioned aqueous solution contains an oxidant. The oxidizing agent is not limited, for example, persulfate such as sodium persulfate, potassium persulfate and ammonium persulfate; nitrate such as cerium ammonium nitrate, sodium nitrate and ammonium nitrate; such as hydrogen peroxide and tertiary butyl peroxide Peroxides of hydrogen oxide; manganese compounds such as potassium permanganate and manganese dioxide; chromium compounds such as potassium chromate and potassium dichromate; superatomic iodine compounds such as potassium periodate and sodium periodate; Quinone compounds such as benzoquinone, naphthoquinone, anthraquinone, and chloranil; amine oxide compounds such as N-methylmorpholin N-oxide, salts of halogen oxyacids such as sodium hypochlorite and sodium chlorite, and salts including Double salt of potassium peroxy-sulfate/potassium hydrogen sulfate/potassium sulfate (OXONE by DuPont de Nemours, Inc.). Among them, it is preferable that the oxidizing agent contains persulfate, and it is more preferable that persulfate. Also, in order to assist the action of the oxidizing agent, a catalyst may be used separately from the oxidizing agent. As said catalyst, a divalent iron compound ( _FeSO4 etc.) and a trivalent iron compound are mentioned, for example. Furthermore, the oxidizing agent and/or the catalyst may also be a hydrate.

Further, the standard redox potential of the oxidizing agent is preferably 0.30 V or more, more preferably 1.50 V or more, and even more preferably 1.70 or more. The upper limit of the standard redox potential of the oxidizing agent is not limited, for example, it is preferably 4.00V or less, and more preferably 2.50V or less. The above standard redox potential is based on a standard hydrogen electrode.

In the above aqueous solution, the content of the oxidizing agent is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 1 to 20 parts by mass relative to 100 parts by mass of water in the above aqueous solution. An oxidizing agent may be used individually by 1 type, and may use 2 or more types. When the above aqueous solution contains a catalyst, the content of the oxidizing agent is preferably 0.005 to 2 parts by mass, more preferably 0.01 to 2 parts by mass, and more preferably 0.1 to 2 parts by mass relative to 100 parts by mass of water in the above aqueous solution better. A catalyst may be used individually by 1 type, and may use 2 or more types.

(Alkali source) In order to adjust the pH of the said aqueous solution, it is also preferable that the said aqueous solution contains an alkali source in addition to the said component. Examples of the above-mentioned alkali source include inorganic salt groups of alkali metal hydroxides (sodium hydroxide, etc.) and alkaline earth metal hydroxides; and organic salt groups. In the aqueous solution, the content of the alkali source may be appropriately adjusted so that the pH of the aqueous solution can be adjusted to a desired temperature, for example, 0.1 to 10 parts by mass relative to 100 parts by mass of water in the aqueous solution.

<Adsorption step> The adsorption step is the following step: in the presence of at least one of water and an organic solvent, the above-mentioned modified boron nitride particles obtained in the above-mentioned modification step are brought into contact with a surface modifier to obtain a modified boron nitride particle modified by the surface modifier. Modified boron nitride particles. Here, it refers to modified boron nitride particles modified with a surface modifier, especially also referred to as surface modified boron nitride particles. Furthermore, the surface-modified boron nitride particles refer to modified boron nitride particles in a state of adsorbing a surface modifier to perform surface modification, and the surface-modified boron nitride particles are also included in the modified boron nitride particles. In addition, it refers to the part other than the surface modifier among the modified boron nitride particles and the surface-modified boron nitride particles that have not been surface-modified, and is also referred to as a boron nitride oxide particle. That is, the surface-modified boron nitride particles are materials including boron nitride oxide particles and a surface modifier adsorbed on the surfaces of the boron nitride oxide particles.

The adsorption step is carried out in a mixed solution containing at least one of the water and the organic solvent, the modified boron nitride particles obtained in the modification step, and the surface modifier. In the above mixed solution, the modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above modification step are brought into contact with the surface modifier for a period of preferably 0.1 to 24 hours, preferably 0.5 to 10 hours. More preferably, 1.5-6 hours is more preferable. In addition, the temperature of the above-mentioned mixed solution when the modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above-mentioned modification step is brought into contact with the surface modifier also depends on the type of the surface modifier, but for example, 1 ∼200°C is preferable, 10∼160°C is more preferable, and 15∼140°C is further preferable.

The method of contacting the modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above modification step with the surface modifier in the above-mentioned mixed solution is not limited. For example, the use of a machine such as a Sany motor can be used A method of contacting with a stirrer or a magnetic stirrer while performing stirring treatment, and a method of contacting with a pump or the like while circulating a solution of a surface modifier in a box filled with modified boron nitride particles. Furthermore, in the above-mentioned method of contacting while circulating, even if a part of the solution of the surface modifier is brought into contact with the modified boron nitride particles filled in the cell, the other part of the solution of the surface modifier is in contact with each other. The solution of all the modified boron nitride particles and the above-mentioned surface modifier supplied to the adsorption step is also regarded as the above-mentioned mixed liquid as a whole, which exists in the pump and the like and does not come into contact with the modified boron nitride particles. Among them, a method in which the modified boron nitride particles are not destroyed as much as possible in the above-mentioned mixed solution is preferable.

The modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above modification step can be brought into contact with a surface modifier in the above mixed solution, and then the obtained surface modified nitride can be extracted from the above mixed solution. boron particles. The method of extracting the surface-modified boron nitride particles from the above-mentioned mixed solution is not limited, and for example, a method of filtering the above-mentioned mixed solution to separate the surface-modified boron nitride particles as a filtrate is exemplified. It is also preferable to wash the extracted surface-modified boron nitride particles with water and/or organic solvents. It is also preferable to use an oven or the like to dry the surface-modified boron nitride particles after cleaning. In addition, solid components other than modified boron nitride particles (epoxy compounds, etc., described later) that constitute the composition for forming a thermally conductive material as described later may be added to the above-mentioned mixed solution, for example, a composition for forming a thermally conductive material may be produced. At the same time, surface-modified boron nitride particles were produced therein.

(Organic solvents) Examples of the organic solvent used in the adsorption step include methanol, ethanol, 2-propanol, acetonitrile, cyclopentanone, cyclohexanone, ethyl acetate, methyl ethyl ketone, dichloromethane, and tetrahydrofuran. . When an organic solvent is used in the adsorption step, the content of the organic solvent is relative to the above-mentioned content of the above-mentioned modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above-mentioned modification step when the surface modifier is brought into contact with each other. The total mass of the mixed solution is preferably 5 to 99 mass %, more preferably 20 to 90 mass %, and even more preferably 30 to 80 mass %. An organic solvent may be used individually by 1 type, and may use 2 or more types.

(water) In the case where water is used in the adsorption step, the content of water relative to the above-mentioned mixed solution when the modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above-mentioned modification step is brought into contact with the surface modifier The total mass is preferably 5 to 99 mass %, more preferably 20 to 90 mass %, and even more preferably 30 to 80 mass %.

The total content of the water and the organic solvent is 5 to 99% of the total mass of the liquid mixture when the modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above modification step are brought into contact with the surface modifier. The mass % is preferable, 20 to 90 mass % is more preferable, and 30 to 80 mass % is further preferable.

(modified boron nitride particles obtained in the modification step) In the adsorption step, the modified boron nitride particles obtained in the above modification step are used. The modified boron nitride particles obtained in the above modification step are usually boron nitride oxide particles. For example, the use amount of the modified boron nitride particles obtained in the above modification step is preferably 1 to 100 parts by mass, more preferably 10 to 80 parts by mass, and 30 to 100 parts by mass of the organic solvent. 70 parts by mass is more preferable.

(surface modifier) In the adsorption step, surface modifiers are used. Surface modifiers are compounds capable of surface modification of inorganic components (especially boron oxide nitride particles). In addition, in this specification, "surface modification" means the state which an organic substance adsorb|sucks on at least a part of the surface of an inorganic component (boron oxide nitride particle etc.). The form of adsorption is not particularly limited, as long as it is in a bonded state. That is, the surface modification also includes a state in which an organic group obtained by detachment of a part of an organic substance is bonded to the surface of an inorganic component (boron oxide nitride particles, etc.). The bond may be any one of a covalent bond, a coordinate bond, an ionic bond, a hydrogen bond, a van der Waals bond, a metal bond, and the like. The surface modification can form a monolayer on at least a portion of the surface. Monolayers are monolayers formed by chemical adsorption of organic molecules, known as Self-Assembled MonoLayer (SAM). In addition, in this specification, the surface modification may be only a part on the surface of an inorganic substance (a boron nitride oxide particle etc.), and may be the whole.

As the surface modifier, for example, metal coupling agents, resins, carboxylic acids such as long-chain alkyl fatty acids, and previously known surface modifiers such as organic phosphonic acids and organic phosphoric acid esters can be used. In addition, for example, Japanese Patent Laid-Open No. 2009-502529, Japanese Patent Laid-Open No. 2001-192500, Japanese Patent No. 4694929, Paragraphs [0021] to [0093] of International Publication No. 2018/004660, and International Publication No. 2019/ Surfaces described in paragraphs [0020] to [0065] of No. 013325, paragraphs [0020] to [0067] of International Publication No. 2019/013261, and paragraphs [0020] to [0087] of International Publication No. 2019/013323 modifier.

・Metal coupling agent Preferably, the surface modifier is a metal coupling agent. The metal coupling agent is a compound having a hydrolyzable group directly bonded to a metal atom. As said metal atom, Si, Ti, Zr, Al, etc. are mentioned, for example. Examples of the hydrolyzable group include an alkoxy group (preferably having 1 to 10 carbon atoms) and a halogen atom such as a chlorine atom. The number of the hydrolyzable groups directly bonded to the metal atom in the metal coupling agent is preferably one or more, more preferably two or more, and still more preferably three or more. There is no upper limit to the above-mentioned number, for example, 10,000.

It is also preferable that the metal coupling agent has a reactive group. It is preferable that the said reactive group is a group which can be crosslinked with the resin binder or its precursor as mentioned later, for example. Specific examples of the above reactive groups include epoxy groups, oxetanyl groups, vinyl groups, (meth)acryl groups, styryl groups, amine groups, isocyanate groups, mercapto groups, and acid anhydride groups. The number of reactive groups possessed by the metal coupling agent is preferably one or more, more preferably two or more, and still more preferably three or more. There is no upper limit to the above-mentioned number, for example, 10,000.

As a metal coupling agent, a silane coupling agent, a titanium coupling agent, a zirconium dioxide coupling agent, an aluminum coupling agent, and a zirconium aluminate coupling agent are mentioned, for example. Among them, the metal coupling agent is preferably a silane coupling agent.

Examples of the silane coupling agent include γ-aminopropyltriethoxysilane, N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, and trimethoxy[3-( Phenylamino)propyl]silane aminosilane-based silane coupling agent; such as 3-glycidoxypropyltrimethoxysilane and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane Epoxysilane-based silane coupling agents for silanes; such as vinylsilane coupling agents for triethoxyvinylsilane and vinyl-tris(β-methoxyethoxy)silane; such as N-β-( Cationic silane-based silane coupling agent of N-vinylbenzylaminoethyl)-γ-aminopropyltrimethoxysilane hydrochloride; such as phenyltrimethoxysilane and phenyl triethoxysilane Silane-based silane coupling agent; methacrylosilane-based silane coupling agent such as 3-methacryloyloxypropyltrimethoxysilane; acrylic silane-based silane coupling agent such as 3-acryloyloxypropyltrimethoxysilane Isocyanurate silane series silane coupling agent such as 3-isocyanatopropyl triethoxysilane; isocyanurate silane series silane coupling agent such as tris-(trimethoxysilylpropyl) isocyanurate ; Mercaptosilane-based silane coupling agents such as 3-mercaptopropylmethyldimethoxysilane and 3-mercaptopropyltrimethoxysilane; ureasilane-based silane coupling agents such as 3-ureapropyltrialkoxysilane ; and styrylsilane-based silane coupling agents such as p-styryltrimethoxysilane.

Also, the metal coupling agent may be a polymer-type metal coupling agent. The molecular weight is preferably 1000 or more, more preferably 2000 or more. The upper limit is preferably 100,000 or less, and more preferably 10,000 or less. In addition, the equivalent weight of the reactive functional group capable of being crosslinked with the resin binder or its precursor is preferably 1000 g/mol or less, more preferably 500 g/mol or less.

When the metal coupling agent is brought into contact with the modified boron nitride particles (boron oxide nitride particles, etc.) obtained in the above modification step, the contact may be made in a state where the hydrolyzable group in the metal coupling agent is previously hydrolyzed . At this time, a metal hydroxy group (a group in which a hydroxy group and a metal atom are directly bonded) generated by preliminarily hydrolyzing the hydrolyzable group in the metal coupling agent is used to make the metal coupling agent and the above-mentioned modification step. It is also preferable that the obtained modified boron nitride particles (boron nitride oxide particles, etc.) be subjected to a crosslinking reaction.

・Curable compound As the surface modifier, a curable compound can also be used. In addition, the curable compound mentioned here means the component different from the said metal coupling agent.

The curable compound is preferably a compound that can be dissolved in the above-mentioned organic solvent. The curable compound may be a polymer compound (resin) or a low molecular weight compound. The molecular weight of the curable compound is, for example, 300 to 1,000,000.

The curable compound as resin may or may not have thermoplasticity.

The curable compound has a crosslinkable group. It is also preferable that the above-mentioned crosslinkable group is a group capable of performing a crosslinking reaction with the resin adhesive or its precursor (preferably a precursor of the resin adhesive) described later. It is also preferable that the above-mentioned crosslinkable group is a group capable of performing a crosslinking reaction with a hydroxyl group. As said crosslinkable group, an epoxy group, an oxetanyl group, a cyanate group, an isocyanate group, an ethylenic double bond-containing group ((meth)acryloyl group etc.), a carboxyl group, etc. are mentioned, for example. It is preferable that the number of the said crosslinkable group which a curable compound has is 1 or more, and it is more preferable that it is 2 or more. There is no upper limit to the above-mentioned number, for example, 10,000.

Examples of curable compounds of resins include epoxy resins, cyanate resins, phenol resins, imide resins, isocyanate resins, benzodiazepine resins, oxetane resins, amino resins, and polyester resins. , Allyl Resin, Dicyclopentadiene Resin, Polysiloxane Resin, Tris Resin and Melamine Resin. Among them, it is preferable that the resin is epoxy resin or cyanate resin, and epoxy resin is more preferable.

It is preferable that the said epoxy resin has 1 or more (preferably 2 or more) epoxy groups in 1 molecule. In addition, in this specification, a phenoxy resin is also contained in an epoxy resin. Examples of epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, bixylenol type epoxy resin, Phenol novolac type epoxy resin, tertiary butylcatechol type epoxy resin, naphthol type epoxy resin, naphthalene type epoxy resin, naphthalene type 4-functional epoxy resin, naphthylene ether type epoxy resin , Glycidylamine type epoxy resin, Glycidyl ester type epoxy resin, Cresol novolac type epoxy resin, Biphenyl type epoxy resin, Biphenyl aralkyl type epoxy resin, Dicyclopentadiene type ring Oxygen resin, anthracene epoxy resin, linear aliphatic epoxy resin, epoxy resin with butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, epoxy resin containing spiro ring, ring Hexanedimethanol type epoxy resin, trimethylol type epoxy resin and halogenated epoxy resin, etc.

Examples of cyanate resins include bisphenols such as novolak-type cyanate resins, bisphenol A-type cyanate resins, bisphenol E-type cyanate resins, and tetramethylbisphenol F-type cyanate resins. Type cyanate ester resins and prepolymers that have been partially teriminated.

Further, as the surface modifier (for example, as a surface modifier of a curable compound), a resin binder or a precursor thereof (preferably a precursor of a resin binder) to be described later may be used, or compounds other than these may be used.

In addition to this, as a surface modifier, a compound represented by the following general formula (S) can be used as a component different from the above-mentioned surface modifier.

[Chemical formula 1]

In the above general formula (1), E ¹ to E ³ each independently represent a single bond, -NH- or -NR-. R represents a substituent. B ¹ to B ³ each independently represent an aromatic ring group in which the number of carbon atoms as ring member atoms which may have a substituent is 6 or more. l, m, and n each independently represent an integer of 0 or more. In the case where l is 2 or more, the X ^1s in which there are one may be the same or different. In the case where m is 2 or more, there are m X ^2s which may be the same or different. When n is 2 or more, the n X ³ 's present may be the same or different. In addition, the sum of l, m and n is 2 or more. X ¹ to X ³ each independently represent a group represented by the general formula (S2).

[Chemical formula 2]

In the above general formula (S2), * represents a bonding position. D ¹ represents a single bond or a divalent linking group. A ¹ represents an aromatic ring group having 6 or more carbon atoms as ring member atoms which may have a substituent or a cycloalkyl ring group having 6 or more carbon atoms as ring member atoms which may have a substituent. Q and Y ¹ each independently represent a group selected from the group consisting of a valence group including an aldehyde group, a boronic acid group, a hydroxyl group, and an epoxy group, and a group having a valence of an amine group, a thiol group, a carboxylic acid group, and a carboxylic acid anhydride group. group, a specific functional group in the group of groups having a valence of isocyanate group and oxetanyl group. p represents an integer of 0 or more. q represents an integer of 0-2. In the above general formula (S1), when there are plural D ¹ , A ¹ , Q, Y ¹ , p and q, the plural D ¹ , A ¹ , Q, Y ¹ , p and q may be present They are the same or different. However, in the case where l is 1 or more and at least one X ¹ is a hydroxyl group, the atom in B ¹ which is directly bonded to X ¹ which is the aforementioned hydroxyl group and the atom in B ¹ which is directly bonded to E ¹ are not mutually exclusive. Adjacent is better. In the case where m is 1 or more and at least one X ² is a hydroxyl group, the atom in B ² directly bonded to X ² as the hydroxyl group and the atom in B ² directly bonded to E ² are not adjacent to each other is better. In the case where n is 1 or more and at least one X ³ is a hydroxyl group, the atom in B ³ which is directly bonded to X ³ which is the aforementioned hydroxyl group and the atom in B ³ which is directly bonded to E ³ are not adjacent to each other. is better.

For example, the usage-amount of the said surface modifier is 0.0001-20 mass parts with respect to 100 mass parts of said organic solvents, Preferably it is 0.01-15 mass parts, More preferably, it is 0.05-5 mass parts. A surface modifier may be used individually by 1 type, and may use 2 or more types.

<Change in median diameter> In the method of the present invention, it is preferable that the change rate of the median diameter of the boron nitride particles used in the production method and the obtained modified boron nitride particles is small before and after a series of production methods. In particular, when the boron nitride particles used in the present invention are aggregated particles, it is preferable that the aggregated state of the particles is maintained without being destroyed when a series of production methods are passed. Specifically, the change rate of the median diameter obtained from the following formula is preferably less than 10%, and more preferably less than 5%. The lower limit of the change rate of the median diameter is not particularly limited. For example, the change rate of the median diameter may be -5% or more, preferably 0% or more. Formula: Change rate of median diameter (%)=[1-(median diameter of modified boron nitride particles produced)/(median of boron nitride particles used in the production of modified boron nitride particles) value diameter)]×100 As a method of adjusting the rate of change of the median diameter, for example, in the method of the present invention, a method of adjusting the shearing force at the time of mixing and/or stirring the above-mentioned aqueous solution and/or mixed liquid can be mentioned.

[Modified Boron Nitride Particles] The present invention also includes the invention of modified boron nitride particles. Regarding the modified boron nitride particles of the present invention, the oxygen atomic concentration on the surface detected by X-ray photoelectron spectroscopy analysis exceeds 5.0 atom%, the contact angle with water is 90° or less, and the following formula (1 ) to obtain a D value of 0.010 or less. The modified boron nitride particles satisfying such requirements are also referred to as "modified boron nitride particles of the present invention" hereinafter. By using the modified boron nitride particles of the present invention, the thermal conductivity and peel strength of the thermally conductive material become favorable. The reason for this is considered as follows. That is, it is considered that the oxygen atomic concentration on the surface of the modified boron nitride particles of the present invention exceeds 5.0 atom%, and the contact angle with water is 90° or less. Therefore, the modified boron nitride particles of the present invention are considered to form a thermally conductive material. The resin adhesive has good affinity, and it is not easy to cause the cohesion and damage of the thermally conductive material, thereby improving the peel strength of the thermally conductive material. Furthermore, since the modified boron nitride particles of the present invention hardly contain boron hydroxide, it is considered that there is no adverse effect on thermal conductivity due to boron hydroxide, etc., and the affinity with resin binders is good as described above, so it is considered that The transfer of heat in the thermally conductive material can also be smoothed, so that the thermal conductivity of the thermally conductive material can also be good.

The modified boron nitride particles produced by the above-described method of the present invention are usually modified boron nitride particles of the present invention. That is, it is preferable that the method of the present invention is a method for producing the modified boron nitride particles of the present invention. In addition, the preferable conditions of the modified boron nitride particles of the present invention described below are the same as the preferable conditions of the modified boron nitride particles produced by the method of the present invention. In addition, the modified boron nitride particles of the present invention may be modified boron nitride particles produced by methods other than the method of the present invention described above.

The content of boron nitride in the modified boron nitride particles of the present invention is preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more with respect to the total mass of the boron nitride particles . The upper limit of the above-mentioned content is not particularly limited, but is, for example, less than 100% by mass.

The crystal structure of the modified boron nitride particles of the present invention is not limited, and may be, for example, hexagonal boron nitride or cubic boron nitride. In addition, the modified boron nitride particles may be, for example, boron nitride nanosheets or boron nitride nanotubes. The shape of the modified boron nitride particles is not particularly limited, and may be any of a scale shape, a flat shape, a rice grain shape, a spherical shape, a cube shape, a spindle shape, and an irregular shape. In addition, the modified boron nitride particles may be aggregated particles (secondary particles) formed by agglomerating fine particles of these shapes. As a whole, the aggregated particles may be spherical or irregular, for example. Among them, it is preferable that the modified boron nitride particles are aggregated particles from the viewpoint of improving the thermal conductivity at the time of compounding with the resin.

The size of the modified boron nitride particles of the present invention (when the modified boron nitride particles are secondary particles, the size of the secondary particles) is not particularly limited. Among them, the modified boron nitride particles of the present invention preferably have a median diameter of 100 μm or less, more preferably 80 μm or less, and even more preferably 60 μm or less, from the viewpoint of more excellent dispersibility of the particles. The lower limit of the median diameter is not particularly limited, but from the viewpoint of handleability and/or thermal conductivity, 500 nm or more is preferable, 10 μm or more is more preferable, and 15 μm or more is further more preferable.

The compressive fracture strength of the modified boron nitride particles of the present invention (especially the modified boron nitride particles of aggregated particles) is preferably 10.0 MPa or less, more preferably 5.0 MPa or less, and even more preferably 4.0 MPa or less . In addition, the lower limit of the compressive rupture strength is not limited. For example, the compressive rupture strength is preferably 0.5 MPa or more, more preferably 1.0 MPa or more, and even more preferably 1.5 MPa or more. When the compressive fracture hardness of the modified boron nitride particles of the present invention is within the above-mentioned range, the modified boron nitride particles are appropriately strong and brittle, and therefore, when forming a thermally conductive material, a part of the modified boron nitride particles are damaged by the modified boron nitride particles. On the other hand, the modified boron nitride particles are easily filled in the gaps between the particles, and the effect of the present invention is further excellent.

In the modified boron nitride particles of the present invention, the oxygen atomic concentration on the surface of the modified boron nitride particles detected by X-ray photoelectron spectroscopy analysis exceeds 5.0 atom%. Although the upper limit of the said oxygen atom concentration is not specifically limited, For example, it is 20.0 atom% or less.

In the modified boron nitride particles of the present invention, the concentration of carbon atoms on the surface of the modified boron nitride particles detected by X-ray photoelectron spectroscopy analysis is preferably more than 3.0 atom%, more preferably 6.0 atom% or more good. The upper limit of the carbon atom concentration is not particularly limited, but is, for example, 30.0 atom% or less.

The above-mentioned atomic concentration on the surface of the modified boron nitride particles was measured as follows. That is, the modified boron nitride particles were measured by an X-ray photoelectron spectroscopy (XPS) (manufactured by Ulvac-PHI: Versa Probe II). As detailed measurement conditions, monochromatic Al (tube voltage; 15 kV) was used as an X-ray source, and the analysis area was set to 300 μm×300 μm. The peak area values of oxygen atoms, nitrogen atoms, boron atoms, and carbon atoms obtained by the measurement are corrected by the sensitivity coefficient of each element. The oxygen atom concentration and carbon atom concentration on the surface of the modified boron nitride particles can be measured by obtaining the ratio of oxygen atoms and carbon atoms to the corrected total amount of oxygen atoms, nitrogen atoms, boron atoms, and carbon atoms.

Regarding the method of correcting the peak area values of oxygen atoms, nitrogen atoms, boron atoms, and carbon atoms obtained by measurement by the sensitivity coefficient of each element, specifically, for oxygen atoms, the peak area values of 528 eV to 538 eV were Divide by the sensitivity coefficient relative to oxygen atoms of 0.733, for nitrogen atoms, divide the peak area value from 394eV to 403eV by the sensitivity coefficient relative to nitrogen atom 0.499, for boron atoms, divide the peak area value from 187eV to 196eV by relative to The sensitivity coefficient for boron atoms is 0.171, and for carbon atoms, the peak area values from 282 eV to 290 eV are divided by the sensitivity coefficient for carbon atoms, 0.314.

Regarding the modified boron nitride particles of the present invention, the D value calculated from the following formula (1) is 0.010 or less, preferably 0.007 or less. The lower limit of the above D value is not particularly limited, but is, for example, 0 or more. Formula (1): D value=B(OH) ₃ (002)/BN(002) B(OH) ₃ (002): derived from hydrogen with triclinic space group measured by X-ray diffraction Peak intensity of (002) plane of boron oxide (2θ=25°～30°) BN(002): derived from (002) plane of boron nitride with hexagonal space group measured by X-ray diffraction The peak intensity (2θ=27.5°～28.5°)

The contact angle of the modified boron nitride particles of the present invention with water on the surface is 90° or less, preferably 75° or less. The lower limit of the above-mentioned contact angle is not particularly limited, and for example, it exceeds 0°. The contact angle of the modified boron nitride particles with water was measured as follows. That is, the modified boron nitride particles were placed in a 30 mmφ adapter for a hand press, and pressed at a pressure of 600 kgf/cm ² (5880 N/cm ² ) for 1 minute to obtain a powder compact. The contact angle with water was calculated|required by measuring the contact angle with water of the said compact obtained by Kyowa Interface Science Co., Ltd. product contact angle meter (DM700). The contact angle was a value obtained by reading the contact angle 200 ms after the formation of droplets on the compact.

The modified boron nitride particles of the present invention may also be surface-modified boron nitride particles in which a surface modifier is adsorbed on the surface. That is, the modified boron nitride particles of the present invention may be a material containing boron oxide nitride particles and a surface modifier adsorbed on the surfaces of the boron oxide nitride particles. The surface modification agent and the aspect of surface modification (adsorption) of the surface modification agent are as described above. When the modified boron nitride particles of the present invention are surface-modified boron nitride particles, the content of the oxidized boron nitride particles in the surface-modified boron nitride particles is 90 mass relative to the total mass of the surface-modified boron nitride particles % or more is preferable, 99 mass % or more is more preferable, and 99.5 mass % or more is further preferable. The upper limit is less than 100 mass %, preferably 99.9999 mass % or less. The content of the surface modifier in the surface-modified boron nitride particles is preferably 10% by mass or less, more preferably 1% by mass or less, and even more preferably 0.5% by mass or less, relative to the total mass of the surface-modified boron nitride particles. The lower limit is more than 0 mass %, preferably 0.0001 mass % or more, more preferably 0.001 mass % or more, particularly preferably 0.01 mass % or more, and most preferably 0.1 mass % or more.

The modified boron nitride particles of the present invention may be boron nitride oxide particles themselves.

The boron nitride particles of the present invention are preferably used for the production of thermally conductive materials, but the application of the boron nitride particles of the present invention is not limited to this.

[Composition for forming a thermally conductive material (composition)] The present invention also relates to a composition for forming a thermally conductive material (hereinafter, simply referred to as a "composition"). The composition of the present invention contains modified boron nitride particles and a resin binder or a precursor thereof. By using the composition of the present invention, a thermally conductive material having good thermal conductivity and peel strength can be produced.

[Modified boron nitride particles] The modified boron nitride particles containing the composition are at least any of the modified boron nitride particles produced by the method of the present invention and the modified boron nitride particles described as the modified boron nitride particles of the present invention. One, the modified boron nitride particles of the present invention produced by the method of the present invention are preferred. The content of the modified boron nitride particles of the present invention is preferably 10% by mass or more, more preferably 20% by mass or more, and even more preferably 35% by mass or more, based on the total solid content of the composition. The upper limit is less than 100 mass %, preferably 85 mass % or less. Only one type of modified boron nitride particles may be used, or two or more types may be used. In the case of using two or more types of modified boron nitride particles, for example, both modified boron nitride particles having a median diameter of 10 μm or more and modified boron nitride particles having a median diameter of less than 10 μm can be used. Both aggregated modified boron nitride particles and non-aggregated modified boron nitride particles can be used. Furthermore, the total solid content represents the components that form the thermally conductive material, and does not contain a solvent. The components forming the thermally conductive material mentioned herein may be components that undergo a reaction (polymerization) to change the chemical structure when the thermally conductive material is formed. Moreover, as long as it is a component forming a thermally conductive material, its properties may be in a liquid state, and it may be regarded as a solid component.

[Resin binder or its precursor (binder component)] The composition includes a resin binder or a precursor thereof. Hereinafter, the resin binder or its precursor is also collectively referred to as a binder component. The adhesive component may be the resin adhesive itself or a precursor of the resin adhesive.

The composition used as the resin binder itself includes, for example, a composition containing a solvent and a resin binder as a polymer (resin) dissolved in the solvent. By evaporating the solvent of the composition and depositing the resin binder, a thermally conductive material in which the resin binder functions as a binder (bonding agent) can be obtained. Moreover, when a composition contains a thermoplastic resin as a resin binder, the composition may be a composition which contains a resin binder as a thermoplastic resin and does not contain a solvent, for example. After heating and melting the composition, it can be cooled and solidified in a desired form to obtain a thermally conductive material in which the resin adhesive of the thermoplastic resin described above functions as a binder (bonding agent).

The precursor of the resin binder is the following components: for example, in the process of forming the thermally conductive material from the composition, it is polymerized and/or cross-linked under predetermined conditions to become the resin binder (polymer and/or cross-linked body). The resin binder thus formed functions as a binder (bonding agent) in the thermally conductive material. As a precursor of a resin binder, a curable compound is mentioned, for example. As a curable compound, the compound which polymerizes and/or crosslinks and hardens by heat, light (ultraviolet light, etc.) etc. is mentioned. That is, a thermosetting compound and a photocurable compound are mentioned. These compounds may be polymers or monomers. The hardening compound may be a mixture of two or more compounds (eg, a main agent and a hardening agent). Furthermore, the precursor of the resin binder can be chemically reacted with the surface modifier described later.

Examples of resin binders (including resin binders formed from precursors of resin binders) include epoxy resins, polysiloxane resins, phenol resins, polyimide resins, polyester resins, and bismaleimide resins. Amine resins, melamine resins, isocyanate-based resins (polyurethane resins, polyurea resins, polyurethaneurea resins, etc.) and monomer chains with two or more polymerizable double bonds such as radical polymers ((meth)acrylic resins, etc.) Lock polymerized resin.

In addition, the resin binder (including the resin binder formed from the precursor of the resin binder) can be formed by reacting, for example, one or more combinations of the following (functional group 1/functional group 2) between different monomers of resin. (functional group 1/functional group 2) = (polymerizable double bond/polymerizable double bond), (polymerizable double bond/thiol group), (carboxylic acid halide group (carboxylic acid chloride group, etc.)/ first amine group or second amine group), (carboxyl group/first amine group or second amine group) (carboxylic acid anhydride group/first amine group or second amine group), (carboxyl group/aziridine group), ( Carboxyl/Isocyanate), (Carboxy/Epoxy), (Carboxyl/Benzyl Halogen), (First Amino or Second Amino/Isocyanate), (First Amino, Second Amino, or Third Amino) Amine/halogenated benzyl), (first amine/aldehyde), (isocyanato/isocyanato), (isocyanato/hydroxy), (isocyanato/epoxy), (hydroxy/halogenated benzyl), (hydroxyl/carboxylic acid anhydride group), (hydroxyl/alkoxysilyl group), (epoxy group/first amine group or second amine group), (epoxy group/carboxylic acid anhydride group), (epoxy group/ hydroxyl), (epoxy/epoxy), (oxetanyl/epoxy), (alkoxysilyl/alkoxysilyl), etc. In addition, a polymerizable double bond shows the double bond between carbons which can be polymerized by radical polymerization etc., for example, the double bond between carbons in a (meth)acryloyl group and a vinyl group is mentioned.

Among them, the composition preferably contains a precursor of a resin adhesive as the adhesive component, and more preferably contains a precursor of a resin adhesive capable of forming an epoxy resin. One type of resin binder may be used alone, or two or more types may be used.

＜Epoxy resin＞ The resin adhesive (especially, the resin adhesive formed from the precursor of the resin adhesive) is preferably an epoxy resin. That is, it is preferable that the composition contains a binder component capable of forming an epoxy resin (ie, an epoxy compound, etc.). The epoxy resin can be formed from an epoxy compound alone or by polymerizing an epoxy compound and other compounds (active hydrogen group-containing compounds such as phenol compounds and amine compounds, and/or acid anhydrides, etc.). Among them, the epoxy resin is preferably formed by reacting an epoxy compound with another compound (preferably a phenol compound).

(epoxy compound) An epoxy compound is a compound which has at least 1 epoxy group (oxirane group) in 1 molecule. The above-mentioned epoxy group is a group obtained by removing one or more hydrogen atoms (preferably one hydrogen atom) from an ethylene oxide ring. If possible, the above-mentioned epoxy group may further have a substituent (linear or branched alkyl group having 1 to 5 carbon atoms, etc.).

The number of epoxy groups contained in the epoxy compound in one molecule is preferably 2 or more, more preferably 2 to 40, further preferably 2 to 10, and particularly preferably 2. The molecular weight of the epoxy compound is preferably 150-10,000, more preferably 150-1,000, and even more preferably 200-290.

The epoxy group content of the epoxy compound is preferably 2.0 to 20.0 mmol/g, more preferably 5.0 to 15.0 mmol/g, and even more preferably 5.5 to 14.0 mmol/g. In addition, the said epoxy group content shows the number of the epoxy group which 1 g of an epoxy compound has. It is also preferable that the epoxy compound has an aromatic ring group (preferably an aromatic hydrocarbon ring group).

The epoxy compound may or may not exhibit liquid crystallinity. That is, the epoxy compound may also be a liquid crystal compound. In other words, it may be a liquid crystal compound having an epoxy group.

Among them, the epoxy compound is preferably a polyhydroxy aromatic ring type glycidyl ether (polyhydroxy aromatic ring type epoxy compound). The glycidyl ether of the above-mentioned polyhydroxyaromatic ring type is a compound having 2 or more (preferably 2 to 6, more preferably 2 to 3, further preferably 2) hydroxyl groups as a substituent A structure in which two or more hydroxy glycidyl groups in the aromatic ring are etherified. The above-mentioned aromatic ring may be an aromatic hydrocarbon ring or an aromatic heterocyclic ring, and an aromatic hydrocarbon ring is preferable. The above-mentioned aromatic ring may be polycyclic or monocyclic. The number of ring members of the aromatic ring is preferably 5 to 15, more preferably 6 to 12, and even more preferably 6. The said aromatic ring may have a substituent other than a hydroxyl group, and may not have a substituent. As said polyhydroxy aromatic ring type glycidyl ether, 1, 3- phenylene bis (glycidyl ether) is mentioned, for example.

In addition, as an epoxy compound, the compound (rod-shaped compound) which contains a rod-shaped structure at least partially, and the compound (disc-shaped compound) which contains a disc-shaped structure at least partially are mentioned, for example. Hereinafter, the rod-shaped compound and the disc-shaped compound will be described in detail.

・Rod-shaped compounds Examples of epoxy compounds of rod-shaped compounds include azomethines, azo oxides, cyanobiphenyls, cyanophenyl esters, benzoates, and cyclohexanecarboxylates Acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines, phenyldiethanes, diphenylacetylenes and alkenylcyclohexylbenzonitrile . Not only the low-molecular compound as described above, but also the high-molecular compound can be used. The above-mentioned polymer compound is a polymer compound obtained by polymerizing a rod-shaped compound having a low molecular reactive group. 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 are each independently a single bond or a divalent linking group. A ¹¹¹ and A ¹¹² each independently represent a divalent linking group (spacer) having 1 to 20 carbon atoms. M represents a liquid crystal 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 group represented by L ¹¹¹ , L ¹¹² , L ¹¹³ and L ¹¹⁴ is independently selected from the group consisting of -O-, -S-, -CO-, -NR ¹¹² -, -CO-O- , -O-CO-O-, -CO-NR ¹¹² -, -NR ¹¹² -CO-, -O-CO-, -CH ₂ -O-, -O-CH ₂ -, -O-CO-NR ¹¹² Bivalent linking groups in the group of -, -NR ¹¹² -CO-O- and -NR ¹¹² -CO-NR ¹¹² - are preferred. The above-mentioned R ¹¹² is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom. Among them, it is preferable that L ¹¹³ and L ¹¹⁴ are each independently -O-. Preferably, L ¹¹¹ and L ¹¹² are each independently a single bond.

In the 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 heteroatoms such as non-adjacent oxygen atoms 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-mentioned 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. As a substituent, a halogen atom (a fluorine atom, a chlorine atom, and a bromine atom), a cyano group, a methyl group, and an ethyl group are mentioned, for example. Among them, A ¹¹¹ and A ¹¹² are each independently preferably an alkylene group having 1 to 12 carbon atoms, and more preferably a methylene group.

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

In the general formula (XXII), W ¹ and W ² each independently represent a divalent cyclic alkylene group, a divalent cyclic alkenylene group, an aryl 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-cyclohexadienyl, 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 d 𠯤-3,6-diyl. In the case of a 1,4-cyclohexanediyl group, it may be any isomer of trans and cis structural isomers, or may be a mixture in an arbitrary ratio. Among them, trans is preferred. W ¹ and W ² may each have a substituent. Examples of the substituent include the groups exemplified in the above-mentioned substituent group Y, and more specifically, halogen atoms (fluorine atom, chlorine atom, bromine atom and iodine atom), cyano group, carbon atoms 1-10 alkyl groups (for example, methyl, ethyl, and propyl groups, etc.), alkoxy groups with 1-10 carbon atoms (for example, methoxy and ethoxy groups, etc.), and acyl groups with 1-10 carbon atoms (for example, methyl group, acetyl group, etc.), alkoxycarbonyl group with 1 to 10 carbon atoms (for example, methoxycarbonyl group, ethoxycarbonyl group, etc.), aryloxy group with 1 to 10 carbon atoms (for example, Acetyloxy and propionyloxy, etc.), nitro, trifluoromethyl and difluoromethyl, etc. When there are plural W ^1s , the plural W ^1s may be the same or different from each other.

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

Preferred skeletons among the basic skeletons of the liquid crystal groups represented by the general formula (XXII) are shown below. In the above-mentioned liquid crystal groups, the skeletons may be substituted by substituents.

[Chemical formula 3]

[Chemical formula 4]

Among the above-mentioned skeletons, the biphenyl skeleton is preferable from the viewpoint that the thermal conductivity of the obtained thermally conductive material is more excellent. In addition, the compound represented by the general formula (XXI) can be synthesized by referring to the method described in JP-A No. 11-513019 (WO97/00600). The rod-shaped compound may be a monomer having a liquid crystal group described in Japanese Patent Application Laid-Open No. 11-323162 and Japanese Patent No. 4118691.

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

[Chemical formula 5]

In general formula (E1), L ^E1 each 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 - The alkylene group which may have a substituent or a group including two or more of these combinations is preferred, -O-alkylene group- or -alkylene group-O- is more preferred. In addition, the above-mentioned alkylene group may be any of linear, branched and cyclic, but a linear alkylene group having 1 to 2 carbon atoms is preferred. A plurality of L ^E1s may be the same or different.

In the general formula (E1), L ^E2 independently represents 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 ( -CN)- or -C(-CN)=CH-. Among them, L ^E2 is preferably a single bond, -CO-O- or -O-CO- independently. When there are plural L ^E2s , the plural L ^E2s may be the same or different.

In the general formula (E1), L ^E3 each independently represents a single bond, a 5- or 6-membered aromatic ring group that may have a substituent, or a 5- or 6-membered non-aromatic ring group, including Polycyclic groups of such rings. Examples of the aromatic ring group and non-aromatic ring group represented by L ^E3 include optionally substituted 1,4-cyclohexanediyl, 1,4-cyclohexadienyl, 1,4-cyclohexanediyl, -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 pyridine-3,6-diyl. In the case of a 1,4-cyclohexanediyl group, it may be any isomer of trans and cis structural isomers, or may be a mixture of any ratio. Among them, trans is preferred. Among them, L ^E3 is preferably a single bond, 1,4-phenylene group or 1,4-cyclohexadienyl group. Preferably, the substituents of the group represented by L ^E3 are independently an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group or an acetyl group, and the alkyl group (preferably having 1 carbon atoms) is better. In addition, when a plurality of substituents are present, the substituents may be the same or different, respectively. When there are plural L ^E3s , the plural L ^E3s 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, there may be a plurality of (-L ^E3 -L ^E2 -) which may be the same or different. Among them, pe is preferably 0-2, more preferably 0 or 1, and even more preferably 0.

In the general formula (E1), L ^E4 each independently represents a substituent. The substituents are preferably an alkyl group, an alkoxy group, a halogen atom, a cyano group, a nitro group, or an acetyl group, each independently, and an alkyl group (preferably having 1 carbon atoms) is more preferable. A plurality of L ^E4s may be the same or different, respectively. In addition, when le to be described next is an integer of 2 or more, a plurality of L ^E4s in the same (L ^E4 ) _le may be the same or different.

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

It is preferable that the rod-shaped compound has a biphenyl skeleton from the viewpoint of more excellent thermal conductivity of the obtained thermally conductive material. In other words, it is preferable that the epoxy compound has a biphenyl skeleton, and it is more preferable that the epoxy compound in this case is a rod-shaped compound.

・Disc-shaped compound The epoxy compound, which is a discoid compound, has a discoid structure at least partially. The disk-like structure has at least an alicyclic or aromatic ring. In particular, in the case where the discoid structure has an aromatic ring, the discoid compound can form a columnar structure by forming a stacked structure based on π-π interaction between molecules. Specific examples of the disc-shaped structure include the bitriphenylene structure described in Angew.Chem.Int.Ed. 2012, 51, 7990-7993 or Japanese Patent Laid-Open No. 7-306317, and Japanese Patent Application Laid-Open. Trisubstituted benzene structures and the like described in 2007-2220 A and JP 2010-244038 A.

As long as a discoid compound is used as the epoxy compound, a thermally conductive material showing high thermal conductivity can be obtained. The reason for this is that the disk-shaped compound can conduct planar (two-dimensional) heat in the normal direction, while the rod-shaped compound can conduct heat only linearly (one-dimensionally).

It is preferable that the above-mentioned discotic compound has three or more epoxy groups. The hardened|cured material which consists of the composition of the discotic compound which has 3 or more epoxy groups exists in the tendency for glass transition temperature to be high, and to have 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 discoid compounds include C. Destrade et al., Mol. Crysr. Liq. Cryst., vol. 71, page 111 (1981); .22, Liquid Crystal Chemistry, Chapter 5, Chapter 10, Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., page 1794 (1985); J. Zhang et al. , J.Am.Chem.Soc., vol.116, page 2655 (1994) and in the compounds described in Japanese Patent No. 4592225, etc., at least one (preferably three or more) of the terminals is a ring Oxygen compounds. Examples of the discotic compound include bitriphenylene structures described in Angew.Chem.Int.Ed. 2012, 51, 7990-7993 and Japanese Patent Laid-Open No. 7-306317, and Japanese Patent Laid-Open No. 2007-2220 Among the tri-substituted benzene structures described in Japanese Patent Application Laid-Open No. 2010-244038, at least one (preferably three or more) of the terminals is an epoxy group, and the like.

・Other epoxy compounds As another epoxy compound other than the said epoxy compound, the epoxy compound represented by general formula (DN) is mentioned, for example.

[Chemical formula 6]

In the general formula (DN), n ^DN represents an integer of 0 or more, preferably 0 to 5, and more preferably 1. R ^DN represents a single bond or a divalent linking group. As the divalent linking group, -O-, -O-CO-, -CO-O-, -S-, alkylene group (preferably with 1 to 10 carbon atoms), arylidene group (with carbon number of 1 to 10) 6-20 are preferred.) or groups including these combinations are preferred, alkylene is more preferred, and methylene is more preferred.

As another epoxy compound, the compound which has an epoxy group in a condensed ring is also mentioned. As such a compound, 3,4:8,9- diepoxybicyclo[4.3.0]nonane etc. are mentioned, for example.

As other epoxy compounds, for example, bisphenol A, F, S, AD and the like which are glycidyl ethers such as bisphenol A type epoxy compounds, bisphenol F type epoxy compounds, and bisphenol S can be mentioned. type epoxy compounds, bisphenol AD type epoxy compounds, etc.; hydrogen added bisphenol A type epoxy compounds, hydrogen added bisphenol AD type epoxy compounds, etc.; novolac type glycidyl ether ( Novolac type epoxy compound), cresol novolak type glycidyl ether (cresol novolac type epoxy compound), bisphenol A novolac type glycidyl ether, etc.; dicyclopentadiene Type glycidyl ether (dicyclopentadiene type epoxy compound); dihydroxypentadiene type glycidyl ether (dihydroxypentadiene type epoxy compound); benzene polycarboxylic acid type Glycerides (benzene polycarboxylic acid type epoxy compounds); and trisphenol methane type epoxy compounds.

When the composition contains an epoxy compound, its content is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, and even more preferably 6 to 20% by mass relative to the total solid content of the composition. An epoxy compound may be used individually by 1 type, and may use 2 or more types.

(compounds containing active hydrogen groups) The epoxy resin is preferably formed by reacting an epoxy compound with an active hydrogen group-containing compound. The active hydrogen group-containing compound is a compound having one or more (preferably two or more, more preferably 2 to 10) groups having active hydrogen (active hydrogen group). As an active hydrogen group, a hydroxyl group, a 1st amino group or a 2nd amino group, a mercapto group, etc. are mentioned, for example, Among them, a hydroxyl group is preferable. The active hydrogen group-containing compound is preferably a polyhydric alcohol having 2 or more (preferably 3 or more, more preferably 3 to 6) hydroxyl groups.

Among them, the active hydrogen group-containing compound used in combination with the epoxy compound is preferably a phenol compound. That is, it is preferable that the composition of this invention contains an epoxy compound and a phenol compound as the said resin binder or its precursor. The phenolic compound is a compound having one or more (preferably two or more, more preferably three or more, further preferably 3 to 6) phenolic hydroxyl groups. From the viewpoint of more excellent effects of the present invention, examples of the active hydrogen group-containing compound include compounds represented by the general formula (P1). The compound represented by the general formula (P1) is a phenolic compound.

・Compounds represented by the general formula (P1) General formula (P1) is shown below.

[Chemical formula 7]

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

In the general formula (P1), na and nc each independently represent an integer of 1 or more. Preferably, na and nc are each independently 1 to 4.

In the 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-mentioned alkyl group may be linear or branched. It is preferable that the carbon number of the said alkyl group is 1-10. The above-mentioned alkyl group may or may not have a substituent. The alkyl moiety in the above-mentioned alkoxy group and the alkyl moiety in the above-mentioned alkoxycarbonyl group are the same as the above-mentioned alkyl group. Preferably, R ¹ and R ⁶ are each independently a hydrogen atom or a halogen atom, more preferably a hydrogen atom or a chlorine atom, and even more preferably a hydrogen atom.

In the general formula (P1), R ⁷ represents a hydrogen atom or a hydroxyl group. When there are plural R ^{7s, the plural R 7s present} may be the same or different. When plural R ^7s are present, it is also preferable that at least one R ⁷ among plural R ^7s represents a hydroxyl group.

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

In the general formula (P1), Ar ¹ and Ar ² each independently represent a phenyl ring group or a naphthalene ring group. It is preferable that Ar ¹ and Ar ² are each independently a phenyl ring group.

In the general formula (P1), Q ^a 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-mentioned alkyl group may be linear or branched. It is preferable that the carbon number of the said alkyl group is 1-10. The above-mentioned alkyl group may or may not have a substituent. The alkyl moiety in the above-mentioned alkoxy group and the alkyl moiety in the above-mentioned alkoxycarbonyl group are the same as the above-mentioned alkyl group. The above-mentioned phenyl group may or may not have a substituent. Q ^a is preferably bonded at the para position with respect to the hydroxyl group that the phenyl ring group to which Q ^a is bonded may have. Q ^a is preferably a hydrogen atom or an alkyl group. The above-mentioned alkyl group is preferably a methyl group.

Furthermore, in the general formula (P1), when there are plural R ⁷ , L ^x2 and/or Q ^a , the plural R ⁷ , L ^x2 and/or Q ^a may be the same or different.

・Compounds represented by the general formula (P2) As an active hydrogen group containing compound (preferably a phenol compound), the compound represented by general formula (P2) is also mentioned.

[Chemical formula 8]

In the above-mentioned general formula (P2), when there are plural groups represented by the same symbols, the plural groups represented by the same symbols may be the same or different.

In the general formula (P2), E ¹ to E ⁶ each independently represent a single bond, -NH- or -NR-. R represents a substituent. As a substituent represented by R, a C1-C5 linear or branched alkyl group is mentioned, for example. Preferably, E ¹ to E ⁶ are each independently -NH- or -NR-, more preferably -NH-.

In the general formula (P2), B ¹ , B ² , B ³ and B ⁴ represent organic groups of k+1 valence, l+1 valence, m+1 valence and n+1 valence, respectively, and at least 1 of them Each represents a k+1-valent, l+1-valent, m+1-valent or n+1-valent aromatic ring group which may have a substituent.

The organic group represented by B ¹ to B ⁴ includes, for example, a group obtained by removing j hydrogen atoms from a hydrocarbon which may have a hetero atom having 1 to 20 carbon atoms. In addition, j number means k+1 number, l+1 number, m+1 number or n+1 number. Among them, examples of hydrocarbons before the removal of j hydrogen atoms include optionally substituted aliphatic hydrocarbons having 1 to 20 carbon atoms, optionally substituted aliphatic rings having 3 to 20 carbon atoms, and optionally substituted aliphatic hydrocarbons. Aromatic rings with 3 to 20 carbon atoms, etc. Examples of the aliphatic hydrocarbons having 1 to 20 carbon atoms include methane, ethane, propane, butane, pentane, hexane, and heptane. As a C3-C20 aliphatic ring, a cyclohexane ring, a cycloheptane ring, a norbornane ring, an adamantane ring, etc. are mentioned, for example. Examples of the aromatic ring having 3 to 20 carbon atoms include an aromatic hydrocarbon having 6 to 20 carbon atoms, an aromatic heterocyclic ring having 3 to 20 carbon atoms, and the like. Examples of the aromatic hydrocarbons having 6 to 20 carbon atoms include a benzene ring, a naphthalene ring, an anthracene ring, and the like, and examples of the aromatic heterocycles having 3 to 20 carbon atoms include a furan ring, a pyrrole ring, a thiophene ring, Pyridine ring, thiazole ring, carbazole ring, indole ring and benzothiazole ring, etc.

Among these, as the organic group represented by B ¹ to B ⁴ , a group obtained by removing j hydrogen atoms from an optionally substituted aromatic ring is preferable, and a group obtained by removing j hydrogen atoms from a benzene ring is preferable A group is better.

In the general formula (P2), k, l, m, and n each independently represent an integer of 0 or more. However, the sum of m and n of k, l, and r is two or more. Preferably k, l, m and n are each independently 0 to 5, more preferably 1 to 2. Furthermore, when k is 0, B ¹ does not have X ¹ . In the case where l is 0, B ² does not have X ² . In the case where m is 0, B ³ does not have X ³ . In the case where n is 0, B ⁴ does not have X ⁴ .

In the general formula (P2), the total number of m and n in which k, l, and r exist is two or more, preferably an integer of 2 to 12, and more preferably an integer of 4 to 8. For example, k is preferably 1 or more (more preferably 1-2), l is preferably 1 or more (more preferably 1-2), m is preferably 1 or more (more preferably 1-2), It is preferable that n is 1 or more (more preferably 1 to 2).

L represents a divalent organic group. Examples of the organic group include an optionally substituted divalent aromatic ring group, an optionally substituted divalent aliphatic hydrocarbon group, an optionally substituted divalent aliphatic ring group, -O-, - S-, -N(R ^N )- or -C(=O)- or a combination thereof. R ^N represents a substituent. Examples of the substituent represented by R ^N include a linear or branched alkyl group having 1 to 5 carbon atoms. Moreover, as a substituent which an aromatic ring group, an aliphatic hydrocarbon group, and an aliphatic ring group may have, a C1-C5 linear or branched alkyl group etc. are mentioned, for example.

Examples of the aromatic ring group include an aromatic hydrocarbon group having 6 to 20 carbon atoms, an aromatic heterocyclic group having 3 to 20 carbon atoms, and the like. Examples of the aromatic hydrocarbons constituting the aromatic hydrocarbon groups having 6 to 20 carbon atoms include monocyclic aromatic rings such as benzene rings; polycyclic aromatic rings such as naphthalene rings and anthracene rings; Examples of the aromatic heterocycle include monocyclic aromatic rings such as furan ring, pyrrole ring, thiophene ring, pyridine ring and thiazole ring; polycyclic aromatic rings such as benzothiazole ring, carbazole ring and indole ring; etc. . In addition, about the aromatic ring group which is L, the group which removed two hydrogen atoms from the above-mentioned example is mentioned.

The aliphatic hydrocarbon group includes, for example, an alkylene group having 1 to 12 carbon atoms, and specifically, a methylene group, an ethylidene group, a propylidene group, a butylene group, a pentylene group, a hexylene group, Methyl hexyl and heptyl, etc.

As an aliphatic ring which comprises an aliphatic cyclic group, a cyclohexane ring, a cycloheptane ring, a norbornane ring, an adamantane ring, etc. are mentioned, for example. In addition, about the aliphatic ring group which is L, the group which removed two hydrogen atoms from the above-mentioned example is mentioned.

An optionally substituted divalent aromatic ring group, an optionally substituted divalent aliphatic hydrocarbon group, an optionally substituted divalent aliphatic ring group, or -O-, -S-, -N(R The group formed by ^N )- or -C(=O)- combination is not only a bivalent linking group including these two or more combinations, but also a group of the same type (for example, a single bond) , aromatic ring group) is a bivalent linking group formed by combining two or more.

In the present invention, from the viewpoint of more excellent thermal conductivity of the thermally conductive material, it is preferable that both ends of L are carbon atoms. The terminal carbon atoms may also be part of a cyclic structure. In addition, in the present invention, from the viewpoint of more excellent thermal conductivity of the thermally conductive material, L in the above-mentioned general formula (P2) is a group selected from the group consisting of a divalent aromatic ring group which may have a substituent, a group which may have a substituent At least one divalent organic group selected from the group consisting of a divalent aliphatic cyclic group and an alkylene group which may have a branched chain having 2 or more carbon atoms is preferable, and from the viewpoint of more excellent thermal conductivity, a divalent organic group that may have The divalent organic group of the divalent aromatic ring group of the substituent is more preferable.

In general formula (P2), r is an integer of 0 or more. r is preferably an integer of 0-20, more preferably an integer of 0-10.

In the general formula (P2), X ¹ to X ⁴ each independently represent a group represented by the general formula (P2b).

[Chemical formula 9]

In the above general formula (P2b), * represents a bonding position with any one of B ¹ to B ⁴ .

In the above general formula (P2b), D ¹ represents a single bond or a divalent linking group. Examples of the above-mentioned divalent linking group include -O-, -S-, -CO-, -NR ^N -, -SO ₂ -, an alkylene group, and a group including a combination thereof. R ^N in -NR ^N- represents a hydrogen atom or a substituent. The above-mentioned alkylene group is preferably a linear or branched alkylene group having 1 to 8 carbon atoms. Wherein, D ¹ is "single bond" or "a group formed by a combination selected from the group consisting of -O-, -CO- and alkylene" is preferably, single bond, * ^A -alkylene -O-CO-* ^B , * ^A -CO-O-alkylene-* ^B , * ^A -O-alkylene-O-* ^B , * ^A -CO-O-alkylene-O-CO -* ^B , * ^A -CO-O-alkylene-O-* ^B or * ^A -O-alkylene-O-CO-* ^B are more preferred. ^{* A} is the bonding position on the side opposite to A1, and ^{* B} is the bonding position with A1.

In the above general formula (P2b), A ¹ represents an optionally substituted aromatic ring group or an optionally substituted aliphatic ring group. Furthermore, A ¹ is bonded to D ¹ , Y ¹ and Q through the atom constituting the above-mentioned aromatic ring group or the above-mentioned aliphatic ring group.

The aromatic ring group which may have a substituent as an aspect of A ¹ may be a monocyclic aromatic ring group or a polycyclic aromatic ring group. The number of ring members of the monocyclic aromatic ring group is preferably 5 to 10. The number of rings constituting the polycyclic aromatic ring group is preferably 2 to 4, more preferably 2. Preferably, the number of ring members constituting the polycyclic aromatic ring group is independently 5 to 10. The above-mentioned aromatic ring group may be an aromatic hydrocarbon ring group or an aromatic heterocyclic group. It is preferable that the number of heteroatoms which the said aromatic heterocyclic group has is 1-5. As a hetero atom, a nitrogen atom, a sulfur atom, an oxygen atom, a selenium atom, a tellurium atom, a phosphorus atom, a silicon atom, and a boron atom are mentioned, for example. Among them, a nitrogen atom, a sulfur atom or an oxygen atom is preferable. As said aromatic ring group, a phenyl ring group, a naphthyl ring group, an anthracycline group, a benzothiazole ring group, a carbazole ring group, an indole ring group, etc. are mentioned, for example.

The aliphatic ring group which may have a substituent as an aspect of A ¹ may be a monocyclic ring or a polycyclic ring. The number of ring members of the monocyclic aliphatic ring group is preferably 5 to 10. The number of rings constituting the above-mentioned polycyclic aliphatic ring group is preferably 2 to 4, more preferably 2. The number of ring members constituting the above-mentioned polycyclic cycloalkyl ring group is preferably 5 to 10 each independently. The number of carbon atoms as ring member atoms in the aliphatic ring group is preferably 5 or more, more preferably 6 to 12. The above-mentioned number of carbon atoms as ring member atoms means the number of carbon atoms as ring member atoms constituting the aliphatic ring. As said aliphatic ring group, a cyclohexane ring group, a cycloheptane ring group, a norbornane ring group, and an adamantane ring group are mentioned, for example.

In the above general formula (P2b), Q and Y ¹ each independently represent a group selected from the group consisting of hydroxyl (-OH), amine group, thiol group (-SH), carboxylic acid group (-COOH) and isocyanate group (-NCO) ) specific functional groups in the group.

The amine group as the above-mentioned specific functional group is not particularly limited, and may be any of the first amino group, the second amino group, and the third amino group. For example, -N(R ^E ) ₂ (R ^E is each independently a hydrogen atom or an alkyl group (may be linear or branched)). The number of carbon atoms in the alkyl group is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3. In addition, the alkyl group may have a substituent.

Among them, the specific functional group is preferably a hydroxyl group. Moreover, when the hydroxyl group which is a specific functional group couple|bonds with an aromatic ring group, it is also preferable that a substituent exists in the position (ortho position) adjacent to the said hydroxyl group on the said aromatic ring group. A hydroxyl group having a substituent in such an ortho position is also referred to as an ortho-coordinated hydroxyl group. Furthermore, when the above-mentioned substituents may be present on both of the ortho-coordinated hydroxyl groups on the aromatic ring group, the above-mentioned substituents may be present on one of them or may be present on both of them. Preferably, the above-mentioned substituent present at the ortho position of the ortho-coordinated hydroxyl group is an organic group, more preferably a substituent having 1 to 6 carbon atoms, and even more preferably an alkyl group having 1 to 6 carbon atoms. The above-mentioned alkyl group may be linear or branched. A part of the hydroxyl groups which may be a plurality of specific functional groups may be ortho-coordinated hydroxyl groups, or all of them may be ortho-coordinated hydroxyl groups. When a part or all of the hydroxyl groups are ortho-coordinated hydroxyl groups, it is preferable from the viewpoint that the storage stability of the semi-cured film formed from the composition becomes favorable.

It is preferable that the groups represented by the general formula (P2b) which may exist in a plurality each independently have at least one hydroxyl group as the specific functional group, and it is more preferable that all the specific functional groups are hydroxyl groups. Among all the specific functional groups represented by Q and Y ¹ in the general formula (P2), the number of specific functional groups as hydroxyl groups is preferably 1 or more, more preferably 2 to 15.

In the above general formula (P2b), p represents an integer of 0 or more. Among them, p is preferably 0-5, more preferably 0-1. When p is 0, Y ¹ is directly bonded to any one of B ¹ to B ⁴ . That is, X ¹ to X ⁴ may be the specific functional group itself.

In the above general formula (P2b), q represents an integer of 0 to 2. Among them, q is preferably 0 to 1.

The compound represented by the general formula (P2) may have one type of group represented by the general formula (P2b) alone, or may have two or more types. Among them, the compound represented by the general formula (P2) is preferably "a compound having only a hydroxyl group as a specific functional group".

In addition, as the active hydrogen group-containing compound, for example, benzene polyols such as pyrogallol, biphenyl aralkyl type phenol resin, phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin modified phenol resin , Dicyclopentadienyl phenol addition resin, phenol aralkyl resin, polyvalent phenol novolac resin synthesized from polyvalent hydroxy compound and formaldehyde, naphthol aralkyl resin, trimethylolmethane resin, tetraphenol based Ethane Resin, Naphthol Novolac Resin, Naphthol Phenol Co-Novolac Resin, Naphthol-Cresol Co-Novolac Resin, Biphenyl Modified Phenol Resin, Biphenyl Modified Naphthol Resin, Amino Tris Modified Phenol resins or alkoxy-containing aromatic ring-modified novolak resins are also preferred.

The lower limit value of the hydroxyl group content of the active hydrogen group-containing compound is preferably 3.0 mmol/g or more, and more preferably 4.0 mmol/g or more. The upper limit is preferably 25.0 mmol/g or less, more preferably 20.0 mmol/g or less. In addition, the said hydroxyl group content shows the number of the hydroxyl group (preferably a phenolic hydroxyl group) which the active hydrogen group containing compound 1g has. In addition, the active hydrogen group-containing compound may have an active hydrogen-containing group (a carboxylic acid group, etc.) which can be polymerized with an epoxy compound in addition to a hydroxyl group. The lower limit of the content of active hydrogen in the active hydrogen group-containing compound (total content of hydrogen atoms in hydroxyl groups, carboxylic acid groups, etc.) is preferably 3.0 mmol/g or more, more preferably 4.0 mmol/g or more. The upper limit is preferably 25.0 mmol/g or less, more preferably 20.0 mmol/g or less. In addition, the content of the above-mentioned active hydrogen means the number of active hydrogen atoms contained in 1 g of the active hydrogen group-containing compound.

The upper limit of the molecular weight of the active hydrogen group-containing compound is preferably 2,000 or less, more preferably 1,500 or less, and even more preferably 1,000 or less. The lower limit is preferably 110 or more, and more preferably 300 or more.

When the composition includes the active hydrogen group-containing compound, its content is preferably 1 to 40% by mass, more preferably 3 to 30% by mass, and further preferably 5 to 20% by mass relative to the total solid content of the composition. better. The active hydrogen group-containing compound may be used alone, or two or more kinds may be used.

When the composition contains an epoxy compound and an active hydrogen group-containing compound, the ratio of the content of the epoxy compound to the content of the active hydrogen group-containing compound is the ratio of the epoxy group of the epoxy compound to the active hydrogen group-containing compound The equivalent ratio ("number of epoxy groups"/"number of active hydrogen groups") of active hydrogen groups (preferably hydroxyl groups, more preferably phenolic hydroxyl groups) is 30/70 to 70/30. , the amount of 40/60 to 60/40 is more preferable, and the amount of 45/55 to 55/45 is more preferable. When the composition contains an epoxy compound and/or an active hydrogen group-containing compound, the total content of the epoxy compound and the active hydrogen group-containing compound is preferably 20 to 100 mass % with respect to the total binder components, and 60 -100 mass % is more preferable, and 90-100 mass % is more preferable.

In the composition, the content of the binder component is preferably 5 to 90% by mass, more preferably 10 to 50% by mass, and even more preferably 15 to 40% by mass relative to the total solid content of the composition.

[inorganic] The composition may also contain inorganic substances. The said inorganic substance is a component other than the said modified boron nitride particle. In addition to the modified boron nitride particles produced by the method of the present invention and the modified boron nitride particles of the present invention, even the modified boron nitride is included in the above-mentioned inorganic substances. As the inorganic substance, for example, any inorganic substance which has been conventionally used as a thermally conductive material as an inorganic filler can be used. From the viewpoint of more excellent thermal conductivity and insulating properties of the thermally conductive material, it is preferable that the inorganic substance contains an inorganic nitride or an inorganic oxide, and it is more preferable that it contains an inorganic nitride.

The shape of the inorganic substance is not particularly limited, and may be in a particle shape, a film shape, or a plate shape. The shape of the particulate inorganic substance includes a rice grain shape, a spherical shape, a cube shape, a spindle shape, a scale shape, an aggregated shape, and an irregular shape.

Examples of inorganic oxides include zirconium oxide (ZrO ₂ ), titanium oxide (TiO ₂ ), silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), iron oxide (Fe ₂ O ₃ , FeO, Fe ₃ O ₄ ), copper oxide (CuO, Cu ₂ O), zinc oxide (ZnO), yttrium oxide (Y ₂ O ₃ ), niobium oxide (Nb ₂ O ₅ ), molybdenum oxide (MoO ₃ ), indium oxide (In ₂ O ₃ , In ₂ O), tin oxide (SnO ₂ ), tantalum oxide (Ta ₂ O ₅ ), tungsten oxide (WO ₃ , W ₂ O ₅ ), lead oxide (PbO, PbO ₂ ), bismuth oxide (Bi ₂ O ₃ ), cerium oxide (CeO ₂ , Ce ₂ O ₃ ), antimony oxide (Sb ₂ O ₃ , Sb ₂ O ₅ ), germanium oxide (GeO ₂ , GeO), lanthanum oxide (La ₂ O ₃ ) and oxides Ruthenium (RuO ₂ ), etc. Only one type of the above-mentioned inorganic oxides may be used, or two or more types may be used. The inorganic oxide is preferably titanium oxide, aluminum oxide or zinc oxide, more preferably aluminum oxide. The inorganic oxide may also be an oxide produced by oxidizing a metal prepared as a non-oxide in the environment, etc.

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), Aluminum Nitride (AlN), Chromium Nitride (Cr ₂ N), Copper Nitride (Cu ₃ N), Iron Nitride (Fe ₄ N), Iron Nitride (Fe ₃ N), Lanthanum Nitride (LaN), Lithium Nitride (Li ₃ N), Magnesium Nitride (Mg ₃ N ₂ ), Molybdenum Nitride (Mo ₂ N), Niobium Nitride (NbN), Tantalum Nitride (TaN), Titanium Nitride (TiN), Nitrogen Tungsten nitride (W ₂ N), tungsten nitride (WN ₂ ), yttrium nitride (YN) and zirconium nitride (ZrN), etc. The inorganic nitride preferably contains aluminum atom, boron atom or silicon atom, more preferably contains aluminum nitride, boron nitride or silicon nitride, more preferably contains aluminum nitride or boron nitride, and contains boron nitride as Excellent. Only one kind of the above-mentioned inorganic nitrides may be used, or two or more kinds thereof may be used.

The size of the inorganic substance is not particularly limited, but from the viewpoint of more excellent dispersibility of the inorganic substance, the average particle diameter of the inorganic substance is preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 200 μm or less. The lower limit is not particularly limited, but from the viewpoint of handleability, 10 nm or more is preferable, and 100 nm or more is more preferable. When using a commercial item, the average particle diameter of an inorganic substance adopts a catalog value. When there is no catalog value, the average particle diameter is determined by randomly selecting 100 inorganic substances with an electron microscope, measuring the particle diameters (major diameters) of the inorganic substances, and arithmetically averaging them.

When the composition contains an inorganic substance, its content is preferably 0.5 to 60% by mass, more preferably 1 to 50% by mass, and even more preferably 2 to 40% by mass relative to the total solid content of the composition. Only one kind of inorganic substances may be used, or two or more kinds may be used. Furthermore, the inorganic substance may form a surface-modified inorganic substance together with the surface modifier. As the surface modifier, for example, the surface modifiers listed in the description of the method of the present invention can be used.

The above-mentioned modified boron nitride particles (the modified boron nitride particles produced by the method of the present invention and the modified boron nitride particles of the present invention) and the above-mentioned inorganic substances are also collectively referred to as inorganic components. In the composition, the content of the inorganic component is preferably 40 to 95% by mass, more preferably 50 to 95% by mass, and even more preferably 60 to 95% by mass relative to the total solid content of the composition. The content of the modified boron nitride particles is preferably 10 to 100 mass %, more preferably 25 to 100 mass %, and even more preferably 50 to 100 mass % with respect to the total mass of the inorganic components.

[hardening accelerator] The composition may also contain a hardening accelerator. In particular, in the case where the composition contains the precursor of the resin adhesive, it is preferable to contain a hardening accelerator for forming the resin adhesive from the precursor of the resin adhesive. The type of the curing accelerator to be used may be appropriately determined in consideration of the type of the precursor of the resin binder and the like. Among them, when the above-mentioned resin binder or its precursor contains an epoxy compound, it is preferable that the composition further contains a hardening accelerator. Examples of the curing accelerator include tri-o-triphosphine, triphenylphosphine, boron trifluoride amine complexes, and compounds described in paragraph 0052 of JP-A No. 2012-067225. In addition, tetraphenylphosphonium tetraphenyl borate (TPP-K), tetraphenylphosphonium tetra-p-triborate (TPP-MK), tetra-n-butylphosphonium laurate (TBP- LA), quaternary phosphonium compounds of bis(tetra-n-butylphosphonium) phthalate and bis(naphthalene-2,3-dioxy)phenylsilicate adducts of tetraphenylphosphonium (phosphonium salt) and other onium salt-based hardening accelerators. In addition, 2-methylimidazole (product name; 2MZ), 2-undecylimidazole (product name; C11-Z), 2-heptadecylimidazole (product name; C17Z), 1 ,2-Dimethylimidazole (product name; 1.2DMZ), 2-ethyl-4-methylimidazole (product name; 2E4MZ), 2-phenylimidazole (product name; 2PZ), 2-phenyl-4 -Methylimidazole (product name; 2P4MZ), 1-benzyl-2-methylimidazole (product name; 1B2MZ), 1-benzyl-2-phenylimidazole (product name; 1B2PZ), 1-cyano ethyl-2-methylimidazole (product name; 2MZ-CN), 1-cyanoethyl-2-undecylimidazole (product name; C11Z-CN), 1-cyanoethyl-2- Phenylimidazole trimellitic acid (product name; 2PZCNS-PW), 2,4-diamino-6-[2'-methylimidazole-(1')]-ethyl-s-tris(product name) ; 2MZ-A), 2,4-diamino-6-[2'-undecylimidazole-(1')]-ethyl-s-tris(product name; C11Z-A), 2, 4-Diamino-6-[2'-ethyl-4'-methylimidazole-(1')]-ethyl-s-tris(product name; 2E4MZ-A), 2,4-diamine Alkyl-6-[2'-methylimidazole-(1')]-ethyl-s-tricyanuric acid adduct (product name; 2MA-OK), 2-phenyl-4,5 -Dihydroxymethylimidazole (product name; 2PHZ-PW), 2-phenyl-4-methyl-5-hydroxymethylimidazole (product name; 2P4MHZ-PW), 1-cyanoethyl-2-benzene Imidazole (product name; 2PZ-CN), 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-mesatris (product name; 2MZA-PW) and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-mesocyanuric acid adduct (product name; 2MAOK-PW) and other imidazoles Hardening accelerators, etc. (all manufactured by SHIKOKU CHEMICALS CORPORATION). Furthermore, as a hardening accelerator of a triarylphosphine type, the compound described in the 0052 paragraph of Unexamined-Japanese-Patent No. 2004-043405 is also mentioned. As the phosphorus-based curing accelerator obtained by adding triphenylborane to triarylphosphine, the compounds described in paragraph 0024 of JP-A-2014-005382 can also be used. Among them, from the viewpoint of further excellent peel strength of the thermally conductive material obtained, it is preferable that the hardening accelerator contains a compound containing a phosphorus atom, and it is more preferable that it contains a phosphonium salt. Although the reason for this is not clear, it is presumed as follows: the compound (especially phosphonium salt) containing phosphorus atoms causes the curing to proceed slowly, so that there is sufficient time for the resin binder from the start of the curing of the composition to the complete curing. Its precursor can flow, and the adhesion with the substrate interface and/or the boron nitride interface can be improved, thereby improving the peel strength. The hardening accelerator may also be a compound containing a phosphorus atom or a phosphonium salt itself. The content of the phosphorus atom-containing compound or phosphonium salt is preferably 10 to 100 mass %, more preferably 50 to 100 mass %, and even more preferably 80 to 100 mass % with respect to the total mass of the hardening accelerator. A hardening accelerator may be used individually by 1 type, and may use 2 or more types. The content of the hardening accelerator is preferably 0.002 mass % or more, more preferably 0.02 mass % or more, and even more preferably 0.07 mass % or more with respect to the total solid content of the composition. The content of the hardening accelerator is preferably 5 mass % or less, more preferably 2 mass % or less, and even more preferably 1 mass % or less with respect to the total solid content of the composition. For example, when the composition contains an epoxy compound, the content of the curing accelerator is preferably 0.01 to 10% by mass, more preferably 0.10 to 5% by mass, based on the total amount of the epoxy compound.

[Solvent] The composition may also contain a solvent. The type of the solvent is not particularly limited, and an organic solvent is preferred. As an organic solvent, cyclopentanone, cyclohexanone, ethyl acetate, methyl ethyl ketone, dichloromethane, tetrahydrofuran, etc. are mentioned, for example. When the composition contains a solvent, the content of the solvent is preferably an amount such that the solid content concentration of the composition is 20 to 95% by mass, more preferably 30 to 85% by mass, and more preferably 50 to 80% by mass The amount is further preferred. That is, the content of the solvent is preferably 5 to 80% by mass, more preferably 15 to 70% by mass, and even more preferably 20 to 50% by mass relative to the total mass of the composition.

[Other ingredients] The composition may contain other components than the above. As other components, a dispersing agent, a surface modifier, and a polymerization initiator (a photopolymerization initiator, a thermal polymerization initiator, etc.) are mentioned, for example.

[Manufacturing method of composition] The manufacturing method of a composition is not specifically limited, A well-known method can be employ|adopted, for example, it can manufacture by mixing the above-mentioned various components. When mixing, various components may be mixed at once, or may be mixed sequentially. There is no restriction|limiting in particular in the method of mixing a component, A well-known method can be used. The mixing device used for mixing is preferably a liquid disperser, for example, mixers such as a rotary revolution mixer, a high-speed rotary shear mixer, a rubber mill, a roller mill, a high-pressure jet disperser, and an ultrasonic disperser. , bead mill and homogenizer. One type of mixing device may be used alone, or two or more types may be used. Degassing can be performed before and/or simultaneously with mixing.

[Method of hardening the composition] The composition of the present invention is preferably a composition for forming a thermally conductive material. The composition of the present invention is hardened to obtain a thermally conductive material. The hardening method of the composition is not particularly limited, but a thermal hardening reaction is preferable. The heating temperature when the thermosetting reaction is performed is not particularly limited. For example, what is necessary is just to select suitably within the range of 50-250 degreeC. In addition, when the thermosetting reaction is performed, a plurality of times of heat treatment with different temperatures may be performed. The hardening treatment is preferably performed for the composition in the form of a film or a sheet. Specifically, for example, after the composition is applied to form a film, a curing reaction may be performed. When performing a hardening process, it is preferable to apply|coat a composition on a base material to form a coating film, and to harden it. At this time, the hardening treatment may be performed after further contacting different base materials with the coating film formed on the base material. The hardened product (thermally conductive material) obtained after hardening may or may not be separated from one or both sides of the substrate. Moreover, when performing a hardening process, you may perform a hardening process in the state which apply|coats a composition to a separate base material, forms a coating film, and the obtained coating film is mutually contact|connected. The hardened product (thermally conductive material) obtained after hardening may or may not be separated from one or both sides of the substrate.

The hardening treatment may be terminated when the composition is formed into a semi-hardened state. In addition, after forming the composition into a semi-hardened state, a hardening treatment may be further performed to complete hardening. The hardening treatment for forming the composition into a semi-hardened state (also referred to as "semi-hardening treatment") and the hardening treatment for completing the hardening (also referred to as "main hardening treatment") can be performed as separate steps. .

For example, in the semi-hardening process, after coating the composition on the substrate to form a coating film, the coating film on the substrate can be directly heated without pressure to obtain a semi-hardened thermally conductive material ( Also referred to as a "semi-cured film"), a semi-cured film can also be obtained by heating the coating film on the base material while simultaneously using press processing. In the case of performing press working, the press working may be performed before and after the above-mentioned heating or the like, or may be performed during the above-mentioned heating or the like. When press working is performed in the semi-cured treatment, it may be easy to adjust the film thickness of the semi-cured film obtained 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 where the coating films formed on the separate substrates are laminated, or the semi-curing treatment may be performed in a state where the coating films are not laminated. The semi-hardening treatment may be carried out in a state where the coating film formed from the composition is further brought into contact with materials other than the above coating film.

The obtained semi-cured film can be used as a thermally conductive material as it is, or can be used as a thermally conductive material which is completely cured after further main curing treatment is performed on the semi-cured film. In the main curing treatment, the semi-cured film may be directly heated without pressurization, or the like may be heated after pressurization or while pressurization is performed. At this time, in the main hardening process, you may perform a main hardening process in the state which laminated|stacked individual semi-hardened films, and you may perform a main hardening process in the state which does not laminate|stack semi-hardened films. Moreover, the main hardening process can be implemented in the state which arrange|positions a semi-cured film in contact with the element etc. to be used. It is also preferred that the element and the thermally conductive material of the present invention be followed by a main hardening process.

There is no limitation on the pressing used in the press working that can be performed in the semi-hardening process and/or the hardening process in the main hardening process, and for example, a flat plate pressing can be used, or a roll pressing can be used. In the case of using roll pressing, for example, a base material with a coating film obtained by forming a coating film on a base material by sandwiching a pair of rolls facing each other, and rotating the pair of rolls to make the base material with a coating film It is preferable to apply a pressure to the film thickness direction of the said base material with a coating film while passing a material. As for the said base material with a coating film, a base material may exist only on one surface of a coating film, and a base material may exist on both surfaces of a coating film. The above-mentioned substrate with a coating film may be passed only once or a plurality of times in the roll pressing. When performing the hardening process in the semi-hardening process and/or the main hardening process, etc., only one of the process by flat pressing and the process by rolling may be performed, or both may be performed.

For the production of thermally conductive materials including hardening reactions, you can also refer to "High Thermal Conductivity Composite Materials" (published by CMC, written by Yutaka Takezawa).

The shape of the thermally conductive material is not particularly limited, and can be molded into various shapes according to the application. As a typical shape of the thermally conductive material to be molded, for example, a sheet shape is mentioned. That is, it is also preferable that the thermally conductive material obtained by using the composition of the present invention is a thermally conductive sheet. In addition, the thermal conductivity of the thermally conductive material obtained by using the composition of the present invention is preferably not anisotropic but isotropic.

The thermally conductive material is preferably insulating (electrically insulating). In other words, the composition of the present invention is preferably a thermally conductive insulating composition. For example, the volume resistance of the thermally conductive material at 23°C and relative humidity of 65% 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. The upper limit is not particularly limited, but is usually 10 ¹⁸ Ω·cm or less.

[Use of thermally conductive materials] The thermally conductive material obtained by using the composition of the present invention can be used as a heat-dissipating material such as a heat sink, and can be used for heat-dissipating applications of various elements. More specifically, by arranging a thermally conductive layer containing the thermally conductive material of the present invention on the element to produce a thermally conductive layer-attached element, the thermally conductive layer can effectively dissipate heat generated from the element. The thermally conductive layer may be a thermally conductive layer including a thermally conductive multilayer sheet described later. The thermally conductive material obtained by using the composition of the present invention has sufficient thermal conductivity and high heat resistance, so it is suitable for heat dissipation of power semiconductor elements used in various electronic devices such as personal computers, general household appliances, and automobiles. use. Furthermore, since the thermally conductive material obtained by using the composition of the present invention has sufficient thermal conductivity even in a semi-hardened state, it can also be used as a space between components arranged in various devices, where light for photohardening is difficult to reach. Part of the heat dissipation material. Moreover, since it is also excellent in adhesiveness, it can also be used as an adhesive agent which has thermal conductivity.

The thermally conductive material obtained using the composition of the present invention can be used in combination with other members than the member formed of the composition. For example, a sheet-shaped thermally conductive material (thermally conductive sheet) may be combined with a sheet-shaped support body other than the layer formed of the present composition. As a sheet-like support, a plastic film, a metal film, or a glass plate is mentioned, for example. As the material of the plastic film, for example, polyester such as polyethylene terephthalate (PET), polycarbonate, acrylic resin, epoxy resin, polyurethane, polyamide, polyolefin, cellulose derivative and polysiloxane. As a metal thin film, a copper thin film is mentioned, for example. The film thickness of the sheet-like thermally conductive material (thermally conductive sheet) is preferably 100 to 300 μm, and more preferably 150 to 250 μm.

In addition, the adhesive layer and/or the adhesive layer may be combined with a thermally conductive material (preferably, a thermally conductive sheet). By bonding the thermally conductive material to an object that should transfer heat, such as an element, via such an adhesive layer and/or an adhesive layer, it is possible to achieve stronger bonding between the thermally conductive material and the object. For example, as a thermally conductive multilayer sheet, a thermally conductive multilayer sheet having a thermally conductive sheet and an adhesive layer or an adhesive layer provided on one or both surfaces of the thermally conductive sheet can be produced. Furthermore, one of the adhesive layer and the adhesive layer may be respectively provided on one side or both sides of the thermally conductive sheet, or both may be provided. An adhesive layer may be provided on one surface of the thermally conductive sheet, and an adhesive layer may be provided on the other surface. In addition, an adhesive layer and/or an adhesive layer may be partially provided on one or both surfaces of the thermally conductive sheet, or may be provided on the entire surface. Furthermore, as described above, in the present invention, a thermally conductive material such as a 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 in a hardened state, a semi-hardened state, or an unhardened state. [Example]

Hereinafter, the present invention will be described in further detail based on examples. Materials, usage amounts, ratios, processing contents, processing steps, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Accordingly, the scope of the present invention should not be limitedly construed by the examples shown below.

[Example X (Production and Evaluation of Modified Boron Nitride Particles)] 〔manufacture〕 By the method shown below, the modified boron nitride particles of Examples or Comparative Examples were produced.

<Example 1> To NaOH water (NaOH: 40 g/water: 400 ml), boron nitride particles A (compressive fracture strength of 3.5 MPa, median diameter of 21 μm, aggregated particles) (50 g) were added and stirred. After adding sodium persulfate water (sodium persulfate: 9.6 g/water: 100 ml) to the above NaOH water, the above NaOH water was heated to 50° C. and further stirred for 3 hours (modification step). For stirring, a Sany motor manufactured by Shinto Scientific Co., Ltd. was used, and it was performed at 150 rpm. After cooling the above NaOH water to room temperature, the boron nitride particles in the above NaOH water were collected by filtration, and the filtered and collected boron nitride particles were washed with water (500 ml) and acetonitrile (250 ml) to obtain modified boron nitride particles. 1 (also known as "BNa1"). The obtained modified boron nitride particles 1 were stirred in acetonitrile (100 ml), and a silane coupling agent (manufactured by Shin-Etsu Chemical Co., Ltd.: X12-984S) was further added to the acetonitrile for hydrolysis adjustment. liquid (1.25g). The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment (adsorption step). After the modified boron nitride particles 1 in the acetonitrile were collected by filtration, the modified boron nitride particles 1 collected by filtration were washed with acetonitrile (100 ml), and dried in an oven at 40°C to obtain surface-modified boron nitride. Particle 1 (also known as "BN1"). In addition, regarding the hydrolysis adjustment liquid of the silane coupling agent, the silane coupling agent (1 g), ethanol (500 μl), 2-propanol (500 μl), water (720 μl), and acetic acid (100 μl) were mixed and stirred for 1 hour. to be adjusted. In the following Examples or Comparative Examples, the formulation of the hydrolysis adjustment liquid of the silane coupling agent was the same unless otherwise specified. Moreover, "X12-984S" is a polymer type silane coupling agent which has an epoxy group and an ethoxysilyl group.

<Example 2> Surface-modified boron nitride particles 2 ( Also known as "BN2"). In addition, "KBM-403" is 3-glycidoxypropyltrimethoxysilane.

<Example 3> Boron nitride particles A (50 g) were added to NaOH water (NaOH: 40 g/water: 400 ml) and stirred. After adding sodium persulfate water (sodium persulfate: 9.6 g/water: 100 ml) to the above-mentioned NaOH water, the temperature was raised to 50° C. and further stirred for 3 hours (modification step). For stirring, a Sany motor manufactured by Shinto Scientific Co., Ltd. was used, and it was performed at 150 rpm. After cooling the above-mentioned NaOH water to room temperature, the boron nitride particles in the above-mentioned NaOH water were collected by filtration, and the filtered and collected boron nitride particles were washed with water (500ml) and cyclopentanone (250ml), thereby obtaining a modified nitride boron particles. To the obtained modified boron nitride particles, cyclopentanone (100 ml) and epoxy resin (Mitsubishi Chemical Corporation, YX7180BH40) (1 g) were added, and the obtained mixed solution was stirred at 120° C. for 3 hours. Adsorption treatment (adsorption step) was performed. The modified boron nitride particles in the above mixed solution were collected by filtration, washed with cyclopentanone (100ml), and the modified boron nitride particles collected by filtration were dried in an oven at 40°C to obtain surface-modified boron nitride. Particle 3 (also known as "BN3").

<Example 4> Boron nitride particles A (50 g) were added to NaOH water (NaOH: 40 g/water: 400 ml) and stirred. After adding sodium persulfate water (sodium persulfate: 9.6 g/water: 100 ml) and iron sulfate heptahydrate (1.1 g) to the above-mentioned NaOH water, the above-mentioned NaOH water was heated to 50°C and further stirred for 3 hours (changed to qualitative steps). For stirring, a Sany motor manufactured by Shinto Scientific Co., Ltd. was used, and it was performed at 150 rpm. After cooling the above NaOH water to room temperature, the boron nitride particles in the above NaOH water were collected by filtration, and the boron nitride particles collected by filtration were washed with 1N hydrochloric acid water (500ml), water (500ml) and acetonitrile (250ml) to obtain modified boron nitride particles. The obtained modified boron nitride particles were stirred in acetonitrile (100 ml), and a hydrolysis adjustment liquid (1.25 g) containing a silane coupling agent (X12-984S) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment (adsorption step). After the modified boron nitride particles in the acetonitrile were collected by filtration, the modified boron nitride particles collected by filtration were washed with acetonitrile (100 ml) and dried in an oven at 40°C, thereby obtaining surface-modified boron nitride particles 4 (Also known as "BN4").

<Example 5> To water (400 ml), boron nitride particles A (50 g) were added and stirred to obtain a mixed liquid. After adding sodium hypochlorite water (sodium hypochlorite pentahydrate: 48 g/water: 100 ml) to the above-mentioned mixed solution, the above-mentioned mixed solution was heated to 50° C. and further stirred for 3 hours (modification step). For stirring, a Sany motor manufactured by Shinto Scientific Co., Ltd. was used, and it was performed at 150 rpm. After cooling the above mixed solution to room temperature, the boron nitride particles in the above mixed solution were collected by filtration, and the filtered and collected boron nitride particles were washed with water (500ml) and acetonitrile (250ml) to obtain modified boron nitride. particle. The obtained modified boron nitride particles were stirred in acetonitrile (100 ml), and a hydrolysis adjustment liquid (1.25 g) containing a silane coupling agent (X12-984S) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment (adsorption step). After the modified boron nitride particles in the acetonitrile were collected by filtration, the modified boron nitride particles collected by filtration were washed with acetonitrile (100 ml), and dried in an oven at 40°C to obtain surface-modified boron nitride particles 5 (Also known as "BN5").

<Example 6> Boron nitride particles A (50 g) were added to NaOH water (NaOH: 40 g/water: 400 ml) and stirred. After further adding ceric ammonium nitrate water (ceric ammonium nitrate: 9.6 g/water: 100 ml) to the above NaOH water, the above NaOH water was heated to 50° C. and further stirred for 3 hours (modification step). For stirring, a Sany motor manufactured by Shinto Scientific Co., Ltd. was used, and it was performed at 150 rpm. After cooling the above NaOH water to room temperature, the boron nitride particles in the above NaOH water were collected by filtration, and the boron nitride particles collected by filtration were washed with 1N hydrochloric acid water (500ml), water (500ml) and acetonitrile (250ml) to obtain modified boron nitride particles. The obtained modified boron nitride particles were stirred in acetonitrile (100 ml), and a hydrolysis adjustment liquid (1.25 g) containing a silane coupling agent (X12-984S) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment (adsorption step). After the modified boron nitride particles in the acetonitrile were collected by filtration, the modified boron nitride particles collected by filtration were washed with acetonitrile (100 ml) and dried in an oven at 40°C, thereby obtaining surface-modified boron nitride particles 6 (Also known as "BN6").

<Example 7> Surface-modified boron nitride particles 7 (also called surface-modified boron nitride particles 7) were obtained by the same production method as in Example 1, except that the sodium persulfate water of Example 1 was used (sodium persulfate: 48 g/water: 400 ml). "BN7").

<Example 8> Surface-modified boron nitride particles 8 (also referred to as "BN8") were obtained by the same production method as in Example 1, except that the NaOH water of Example 1 was used (NaOH: 2 g/water: 400 ml). .

<Example 9> Surface-modified boron nitride particles were obtained by the same production method as in Example 1, except that the sodium persulfate water in Example 1 was potassium iodate water (potassium iodate: 9.6 g/water: 100 ml). 9 (also known as "BN9").

<Example 10> Boron nitride particles A (10 g) were added to NaOH water (NaOH: 8 g/water: 80 ml) and stirred. After adding sodium persulfate water (sodium persulfate: 1.9 g/water: 20 ml) to the above NaOH water, the above NaOH water was stirred for 3 hours (modification step). The stirring was performed using a paint conditioner and glass beads having a diameter of 0.5 mm. The boron nitride particles in the above NaOH water were collected by filtration, and the boron nitride particles collected by filtration were washed with water (500 ml) and acetonitrile (250 ml). The obtained modified boron nitride particles were stirred in acetonitrile (100 ml), and a hydrolysis adjustment liquid (1.25 g) containing a silane coupling agent (X12-984S) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment (adsorption step). After the modified boron nitride particles in the acetonitrile were collected by filtration, the modified boron nitride particles collected by filtration were washed with acetonitrile (100 ml), and dried in an oven at 40°C to obtain surface-modified boron nitride particles 10 (Also known as "BN10").

<Example 11> The boron nitride particles of Example 1 were obtained by the same production method as in Example 1, except that the boron nitride particles B (median diameter 30 μm, aggregated particles) having a compressive rupture strength of 8.0 MPa were used. Surface-modified boron nitride particles 11 (also referred to as "BN11").

<Example 12> Surface-modified boron nitride particles were obtained by the same production method as in Example 1, except that the boron nitride particles of Example 1 were changed to boron nitride particles C (scaly particles) having a median diameter of 4 μm. 12 (also known as "BN12").

<Comparative Example 1> To water (400 ml), boron nitride particles A (50 g) were added and stirred to obtain a mixed liquid. After 30 mass % of hydrogen peroxide water (30 ml) was further added to the said liquid mixture, the said liquid mixture was heated up to 50 degreeC, and it stirred for further 3 hours. For stirring, a Sany motor manufactured by Shinto Scientific Co., Ltd. was used, and it was performed at 150 rpm. After cooling the above mixed solution to room temperature, the boron nitride particles in the above mixed solution were collected by filtration, and the filtered and collected boron nitride particles were washed with water (500ml) and acetonitrile (250ml) to obtain modified boron nitride. particle. The obtained modified boron nitride particles were stirred in acetonitrile (100 ml), and a hydrolysis adjustment solution (1.25 g) containing a silane coupling agent (KBM-403) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment. After the modified boron nitride particles in the acetonitrile were collected by filtration, the modified boron nitride particles collected by filtration were washed with acetonitrile (100 ml) and dried in an oven at 40°C to obtain surface-modified boron nitride particles b1 (Also known as "BNb1").

<Comparative Example 2> Surface-modified boron nitride particles b2 (also referred to as "BNb2") were obtained by the same production method as in Example 1, except that the NaOH water in Example 1 was changed to (NaOH: 0.02 g/water: 400 ml). ).

<Comparative Example 3> Referring to Japanese Patent No. 3468615, boron nitride particles A (50 g) were heated at 1000° C. for 1 hour to obtain modified boron nitride particles. The obtained modified boron nitride particles were stirred in acetonitrile (100 ml), and a hydrolysis adjustment solution (1.25 g) containing a silane coupling agent (KBM-403) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment. After the modified boron nitride particles in the acetonitrile were collected by filtration, the modified boron nitride particles collected by filtration were washed with acetonitrile (100 ml), and dried in an oven at 40°C to obtain surface-modified boron nitride particles b3 (Also known as "BNb3").

<Comparative Example 4> The boron nitride particles A (50 g) were stirred in acetonitrile (100 ml), and a hydrolysis adjustment liquid (1.25 g) containing a silane coupling agent (KBM-403) was further added to the acetonitrile. The above-mentioned acetonitrile was stirred at room temperature for 3 hours to perform adsorption treatment. After the boron nitride particles in the acetonitrile were collected by filtration, the boron nitride particles collected by filtration were washed with acetonitrile (100 ml), and dried in an oven at 40°C, thereby obtaining surface-modified boron nitride particles b4 (also known as boron nitride particles). "BNb4").

[Evaluation of modified boron nitride particles] The modified boron nitride particles produced in the respective Examples or Comparative Examples were evaluated by the following methods. Furthermore, the modified boron nitride particles also include surface-modified boron nitride particles.

<Surface oxygen content or surface carbon content> Using an X-ray photoelectron spectrometer (Ulvac-PHI: Versa Probe II), the oxygen atomic concentration and carbon atomic concentration (unit: atom%).

(Oxygen atomic concentration) The oxygen atomic concentrations on the surfaces of the modified boron nitride particles measured were classified into the following categories. In addition, the oxygen atomic concentration on the surface of the modified boron nitride particles of any of the Examples and Comparative Examples was 20.0 atom % or less. A: More than 5.0atom% B: 3.0atom% or more and 5.0atom% or less C: less than 3.0atom%

(carbon atomic concentration) The measured concentrations of carbon atoms on the surface of the modified boron nitride particles were classified into the following categories. In addition, the carbon atom concentration on the surface of the modified boron nitride particles of any example or comparative example was 30.0 atom% or less. A: 6.0 atom% or more B: More than 3.0atom% and less than 6.0atom% C: 3.0 atom% or less

<Contact angle> The modified boron nitride particles were placed in a 30 mmφ adapter for a hand press, and pressed at a pressure of 600 kgf/cm ² (5880 N/cm ² ) for 1 minute to obtain a powder compact. The contact angle of the powder compact with water was measured using a contact angle meter (DM700) manufactured by Kyowa Interface Science Co., Ltd. Contact angle The value of the contact angle 200 ms after the formation of droplets on the compact was read. The measured contact angles of modified boron nitride particles with water are classified into the following categories. In addition, the contact angle of the modified boron nitride particles of any of the Examples and Comparative Examples exceeded 0°. A: Less than 75° B: More than 75° and less than 90° C: More than 90°

<D value> The modified boron nitride particles were subjected to X-ray diffraction measurement, and the D value was determined from the following formula (1). Formula (1): D value=B(OH) ₃ (002)/BN(002) B(OH) ₃ (002): derived from hydrogen with triclinic space group measured by X-ray diffraction Peak intensity of (002) plane of boron oxide (2θ=25°～30°) BN(002): derived from (002) plane of boron nitride with hexagonal space group measured by X-ray diffraction Peak intensity (2θ=27.5° to 28.5°) The D values of the modified boron nitride particles obtained were classified into the following categories. A: Less than 0.007 B: More than 0.007 and less than 0.010 C: More than 0.010

<Rate of change in median diameter> Using Master sizer 2000 manufactured by Malvern Panalytical Ltd, the median diameter of the boron nitride particles used in the production of the modified boron nitride particles and the diameter of the produced boron nitride particles were determined under dry measurement conditions with dispersion air pressure: 2.0 Bar. The median diameter of the modified boron nitride particles. The change rate of the median diameter in the process of producing the modified boron nitride particles was obtained by substituting the obtained median diameter into the following formula. Formula: Change rate of median diameter (%)=[1-(median diameter of modified boron nitride particles produced)/(median of boron nitride particles used in the production of modified boron nitride particles) value diameter)]×100 The change rates of the obtained median diameters are classified into the following categories. In addition, the change rate of the median diameter of the modified boron nitride particles of any of the Examples and Comparative Examples was 0% or more. A: less than 5% B: 5% or more and less than 10% C: 10% or more

<median diameter> The median diameter of the modified boron nitride particles was measured by the same method as the above-mentioned <change rate of median diameter>, and was classified into the following categories. In addition, the median diameter of the modified boron nitride particles in any of the Examples or Comparative Examples was 0.5 μm or more. A: The median diameter is 10 μm or more B: The median diameter is less than 10 μm

<Compression rupture strength> The compression test was performed using a micro-compression tester MCT-510 manufactured by Shimadzu Corporation, and the compressive rupture strength was measured using the produced agglomerated modified boron nitride particles as a sample. The compression test was performed as follows: a graph showing the test force (mN)-displacement (um) at the time of failure of the sample when a load was applied to the sample with an indenter, and the test force (mN) at which the displacement became constant was set as the failure point P , and calculate the breaking strength (MPa) from the following formula. A. Compressive failure strength (MPa)=(2.48P)/(3.14d ² ) d: The particle size measurement conditions are set as follows: indenter=FLAT120, test force=20 (mN), load speed=0.4462 (mN/sec) ), load holding time = 5 (sec). Ten arbitrary aggregated particles were selected from the obtained modified boron nitride particles, the compressive fracture strength was measured, and the average value was obtained. In addition, the said particle diameter (d) was calculated|required by measuring the length of the long axis of the agglomerated modified boron nitride particle from the SEM observation image of a magnification of 200 times.

〔result〕 The following table shows the characteristics of the modified boron nitride particles produced in each Example or Comparative Example. In the table, the column of "name" indicates the name of the produced modified boron nitride particles (including surface-modified boron nitride particles). The column of "BN amount" indicates the amount (g) of the boron nitride particles used in the production of the modified boron nitride particles in each Example or Comparative Example. The column of "amount" in the column of "oxidant" indicates the amount (g) of the oxidant used in the production of modified boron nitride particles. The column of "pH" shows the pH of the above-mentioned aqueous solution when the boron nitride particles are brought into contact with an oxidizing agent in an aqueous solution for modification. For example, in the case where modified boron nitride particles 1 (BNa1) and surface-modified boron nitride particles 1 (BN1) were produced in Example 1, NaOH water (NaOH: 40 g/water: 400 ml), boron nitride The pH value of the liquid (aqueous solution) obtained by mixing 50 g of particles and sodium persulfate water (sodium persulfate: 9.6 g/water: 100 ml) is shown in the "pH" column. The column of "type of surface modifier" indicates the type of surface modifier used in the production of modified boron nitride particles.

[Table 1] name Amount of BN (g) Oxidizer Type of catalyst pH Types of Surface Modifiers Evaluation results type Standard redox potential (V) Amount (g) Oxygen atomic concentration carbon concentration Contact angle D value rate of change of median diameter median diameter Compressive failure strength (MPa) Example 1 BNa1 50 Sodium Persulfate 2.01 9.6 - 14 - A C A A A A 3.5 BN1 50 Sodium Persulfate 2.01 9.6 - 14 X12-984S A A A A A A 3.5 Example 2 BN2 50 Sodium Persulfate 2.01 9.6 - 14 KBM-403 A B A A A A 3.5 Example 3 BN3 50 Sodium Persulfate 2.01 9.6 - 14 YX7180BH40 A A A A A A 3.5 Example 4 BN4 50 Sodium Persulfate 2.01 9.6 Iron sulfate heptahydrate 14 X12-984S A A A A A A 3.5 Example 5 BN5 50 Sodium hypochlorite pentahydrate 1.63 48 - 12 X12-984S A A B A A A 3.5 Example 6 BN6 50 Ceric Ammonium Nitrate 1.74 9.6 - 14 X12-984S A A A A A A 3.5 Example 7 BN7 50 Sodium Persulfate 2.01 48 - 14 X12-984S A A A A A A 3.5 Example 8 BN8 50 Sodium Persulfate 2.01 9.6 - 13 X12-984S A A B A A A 3.5 Example 9 BN9 50 Sodium iodate 1.2 9.6 - 14 X12-984S A A B A A A 3.5 Example 10 BN10 10 Sodium Persulfate 2.01 1.9 - 14 X12-984S A A A A C A 3.5 Example 11 BN11 50 Sodium Persulfate 2.01 9.6 - 14 X12-984S A A A A A A 8.0 Example 12 BN12 50 Sodium Persulfate 2.01 9.6 - 14 X12-984S A A A A A B - Comparative Example 1 BNb1 50 hydrogen peroxide 1.78 10 - 5 KBM-403 C C C A A A 3.5 Comparative Example 2 BNb2 50 Sodium Persulfate 2.01 10 - 11 KBM-403 C C C A A A 3.5 Comparative Example 3 BNb3 50 No oxidants and catalysts (surface oxidation during high temperature treatment) - KBM-403 A B A C A A 3.5 Comparative Example 4 BNb4 50 No oxidants and catalysts - KBM-403 C C C A A A 3.5

[Example Y (Production and Evaluation of Composition)] A composition (composition for forming a thermally conductive material) was prepared and evaluated using the modified boron nitride particles described above. The characteristics of the composition and the test method and the like carried out using the composition are shown below.

[various ingredients] Various components used in Examples and Comparative Examples are shown below. ＜Phenolic compound＞ Phenol compounds used in Examples and Comparative Examples are shown below. In addition, about A-1 of the phenolic compound used in an Example, it synthesize|combined with reference to the specification of US Pat. No. 4,992,596.

(Synthesis method of A-2) About A-2 which is a phenolic compound, it synthesize|combined according to the following scheme.

[Chemical formula 10]

After ice-cooling a mixture of cyanuric chloride (160 g, 0.87 mol) and 2-butanone (750 ml), m-aminophenol (294 g, 2.7 mol) was added little by little. Then, an aqueous solution obtained by dissolving sodium acetate trihydrate (237 g, 1.74 mol) in water (353 ml) was added to the above-mentioned mixed solution. The above mixed solution was stirred at 80°C for 2 hours, cooled to room temperature, and an aqueous solution obtained by dissolving sodium carbonate (221 g, 2.09 mol) in water (1280 ml) was added dropwise to the above mixed solution, followed by stirring for 30 minutes. . After the above mixture was left to stand and the aqueous phase was removed, the organic phase was filtered through celite, and 321 ml of ethanol was added. Water (4.1 L) was added dropwise to the obtained organic phase with stirring, and after stirring for 2 hours, the precipitated crystals were collected by filtration and dried to obtain A-2.

(Synthesis method of A-3) A-3, which is a phenolic compound, was synthesized according to the following scheme.

[Chemical formula 11]

After ice-cooling a mixture of cyanuric chloride (60 g, 0.325 mol) and 2-butanone (480 ml), m-aminophenol (71 g, 0.65 mol) was added little by little. Then, an aqueous solution obtained by dissolving sodium acetate trihydrate (93 g, 0.68 mol) in water (240 ml) was added to the above-mentioned mixed solution. After the above-mentioned mixed solution was stirred at 45°C for 3 hours, it was cooled to room temperature, and allowed to stand to remove the aqueous phase. After the organic phase was washed with 200 ml of 1N hydrochloric acid water and 200 ml of 10% brine in this order, magnesium sulfate was added to the organic layer, followed by filtration. The obtained organic phase was subjected to solvent distillation with a distiller, and the obtained crystal was washed with hexane and dried to obtain an intermediate of A-3.

To a mixture of the intermediate A-3 (11.4 g, 34.6 mmol) and 2-butanone (53 ml) was added m-tolidine (3.5 g, 16.5 mmol). Water (27 ml) was added to the above-mentioned liquid mixture, and the mixture was stirred at 80° C. for 2 hours, and then cooled to room temperature. An aqueous solution obtained by dissolving sodium carbonate (2.8 g, 26.4 mmol) in water (16 ml) was added dropwise to the above mixed solution, followed by stirring for 30 minutes. After the above-mentioned mixed solution was left to stand and the aqueous phase was removed, the organic phase was filtered through celite. The obtained organic phase was removed by solvent distillation with a distiller, and the obtained crystal was washed with hexane and dried to obtain A-3.

(Synthesis method of A-4) A-4, which is a phenolic compound, was synthesized by the same method as A-2 except that the m-aminophenol of A-2 was changed to 5-amino-o-cresol.

[Chemical formula 12]

＜Epoxy compound＞ The epoxy compounds used in Examples and Comparative Examples are shown below.

[Chemical formula 13]

＜Hardening accelerator＞ The hardening accelerators used in Examples and Comparative Examples are shown below. "PPh3": triphenylphosphine "TOTP": tri-ortho-triphosphine "TPP-MK": Tetraphenylphosphonium tetra-p-triborate

＜Solvent＞ As a solvent, cyclopentanone was used.

＜Inorganic components＞ The inorganic components used in Examples and Comparative Examples are shown below. "AA-3": Alumina (average particle size: 3 μm, manufactured by Sumitomo Chemical Co., Ltd.) "AA-04": Alumina (average particle size: 0.4 μm, manufactured by Sumitomo Chemical Co., Ltd.) "SP-3": Scale-like boron nitride (average particle size: 4 μm, manufactured by Denka Company Limited) "BNa1", "BN1", "BN2", "BN3", "BN4", "BN5", "BN6", "BN7", "BN8", "BN9", "BN10", "BN11", "BN12" ", "BNb1", "BNb2", "BNb3", "BNb4": modified boron nitride particles produced by the above methods respectively In addition, "BNa1" and "BN1" - "BN12" are the modified boron nitride particles of the present invention produced by the method of the present invention. "BNb1" to "BNb4" are modified boron nitride particles other than the modified boron nitride particles of the present invention produced by methods other than the method of the present invention.

[Preparation of composition] A mixture was prepared in which the epoxy compound and the phenol compound of the combination shown in the following Table 2 were blended in the ratio of the addition amount described in the following Table 2. After mixing the total amount of the obtained mixture, the solvent, and the hardening accelerator in this order, an inorganic substance was added. The obtained mixture was treated with an autorotation revolution mixer (Awatori NetaroARE-310, manufactured by Thinky Corporation) for 5 minutes to obtain a composition (a composition for forming a thermally conductive material) of each Example or Comparative Example. The mixing ratio of each component was adjusted so that the content of each component in the finally obtained composition and the mixing ratio (mass %) of the total solid content were as shown in Table 2.

Here, the amount of the solvent added is set to an amount in which the solid content concentration of the composition is 50 to 80% by mass. In addition, regarding the solid content concentration of a composition, each composition was adjusted in the said range so that the viscosity of each composition might become the same degree. The addition amount of the inorganic substance (the total addition amount of the inorganic nitride and other inorganic substances) was set as the addition amount shown in Table 2 below. Moreover, inorganic substances were mixed so that the content ratio (mass ratio) of each inorganic substance satisfies the relationship shown in the following Table 2, and was used.

〔evaluate〕 The composition was evaluated by the method shown below.

<Production of thermally conductive sheet> Using an applicator, the prepared compositions of each Example or Comparative Example described in Table 2 below were uniformly coated on a release-treated polyester film (NP-100A, manufactured by PANAC Co., Ltd.). , film thickness of 100 μm) on the mold release surface, and left at 120° C. for 5 minutes to obtain a semi-hardened sheet (semi-hardened film). The obtained semi-hardened sheet was treated under air by hot pressing (after treatment at a hot plate temperature of 180° C. and a pressure of 20 MPa for 5 minutes, and further at 180° C. under normal pressure for 90 minutes) to make a coating film. hardened, thereby obtaining a resin sheet. The polyester film was peeled off from the resin sheet to obtain a thermally conductive sheet (thermally conductive material) having an average film thickness of 120 μm.

＜Thermal conductivity＞ Thermal conductivity evaluation was performed using each thermally conductive sheet obtained using each composition. The thermal conductivity was measured by the following method, and the thermal conductivity was evaluated according to the following criteria.

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

(Evaluation Criteria) The thermal conductivity of the thermally conductive sheet of the evaluation object obtained by using each composition and the composition for comparison in which the modified boron nitride particles used in each composition were replaced with untreated boron nitride particles were used. The thermal conductivity of the control thermally conductive sheet was compared. Based on the thermal conductivity of the thermally conductive sheet for comparison, how the thermal conductivity of the thermally conductive sheet to be evaluated changes was classified according to the following criteria to evaluate the thermal conductivity. In addition, the untreated boron nitride particles used in the respective compositions refers to the boron nitride particles B used in Example 11 when BN11 was used as the modified boron nitride particles, When BN12 was used, the boron nitride particles C used in Example 12 were used, and when other modified boron nitride particles were used, the boron nitride particles A were used. "A": increase above 1.5W/mK "B": 0.5W/mK or more and less than 1.5W/mK increase "C": no change or an increase of less than 0.5W/mK "D": decrease

<Peel Strength Test> The polyester film was peeled off from the polyester film-attached semi-hardened sheet produced by the method shown in the above-mentioned <Production of Thermally Conductive Sheet>, the obtained semi-hardened sheet was cut into strips of 20 mm×60 mm, and the It is sandwiched between an electrolytic copper foil (20mm×100mm, thickness: 35μm) as an adherend and an aluminum plate (30mm×60mm, thickness: 1mm). The obtained laminate was subjected to hot press treatment under air (after treatment at a hot plate temperature of 180° C. and a pressure of 20 MPa for 5 minutes, followed by a treatment at a hot plate temperature of 180° C. and normal pressure for 90 minutes) to obtain A copper foil-attached aluminum substrate is formed integrally with a thermally conductive sheet and an adhesive body. Using a digital force gauge (ZTS-200N, manufactured by IMADA Co., Ltd.) and a 90-degree peel test fixture (P90-200N-BB, manufactured by IMADA Co., Ltd.) Measurement method of peel strength under normal conditions The copper foil peel strength of the obtained samples was measured. The peeling of the copper foil in the peel strength test was performed at an angle of 90° and a peeling speed of 50 mm/min with respect to the aluminum base substrate with copper foil. In addition, when the peeling strength test was performed, the form of the failure of the test body was the aggregation failure in the thermally conductive sheet layer.

(Peel Strength Evaluation Criteria) From the peeling strength of the copper foil measured by the above method, the peeling strength of the thermally conductive sheet was evaluated based on the following criteria. The peeling strength of copper foil on the aluminum base substrate with copper foil, which is the evaluation object, produced by using the semi-hardened sheet obtained by each composition was compared with that of the aluminum base substrate with copper foil for comparison, which was produced by using the semi-hardened sheet. The above copper foil peel strength was compared, and the semi-hardened sheet was obtained using a control composition in which the modified boron nitride particles used in each composition were replaced with untreated boron nitride particles. Based on the peel strength of copper foil on the aluminum base substrate with copper foil for comparison, how the peel strength of copper foil on the aluminum base substrate with copper foil attached to the evaluation object changes is classified according to the following criteria and used as peeling Strength evaluation. "A+": increase above 2.0N/cm "A": 1.5N/cm or more and less than 2.0N/cm increase "B": 0.5N/cm or more and less than 1.5N/cm increase "C": no change or an increase of less than 0.5N/cm "D": decrease

〔result〕 Table 2 below shows the results of blending and evaluating the solid content of the compositions of the Examples or Comparative Examples. In the table, the column of "amount (%)" indicates the content (mass %) of each component with respect to the total solid content of the composition.

[Table 2] Composition of the solid content of the composition evaluate Phenolic compounds epoxy compound hardening accelerator Inorganic Thermal conductivity peel strength type quantity(%) type quantity(%) type quantity(%) mass ratio in inorganic matter quantity(%) Example 13 A-2 12.73 B-1 11.11 PPh3 0.16 BN1 only 76.00 A A Example 14 A-2 12.73 B-1 11.11 PPh3 0.16 BN2 only 76.00 A A Example 15 A-2 12.73 B-1 11.11 PPh3 0.16 BN3 only 76.00 A A Example 16 A-2 12.73 B-1 11.11 PPh3 0.16 BN4 only 76.00 A A Example 17 A-2 12.73 B-1 11.11 PPh3 0.16 BN5 only 76.00 B B Example 18 A-2 12.73 B-1 11.11 PPh3 0.16 BN6 only 76.00 A A Example 19 A-2 12.73 B-1 11.11 PPh3 0.16 BN7 only 76.00 A A Example 20 A-2 12.73 B-1 11.11 PPh3 0.16 BN8 only 76.00 B B Example 21 A-2 12.73 B-1 11.11 PPh3 0.16 BN9 only 76.00 B B Example 22 A-2 12.73 B-1 11.11 PPh3 0.16 BN10 only 76.00 C A Example 23 A-2 12.73 B-1 11.11 PPh3 0.16 BN11 only 76.00 C A Example 24 A-2 12.73 B-1 11.11 PPh3 0.16 BNa1 only 76.00 B B Example 25 A-1 9.00 B-1 14.84 PPh3 0.16 BN1 only 76.00 A A Example 26 A-1 6.99 B-2 16.85 PPh3 0.16 BN1 only 76.00 A A Example 27 A-1 6.49 B-3 17.35 PPh3 0.16 BN1 only 76.00 A A Example 28 A-2 10.47 B-2 13.37 PPh3 0.16 BN1 only 76.00 A A Example 29 A-2 9.86 B-3 13.98 PPh3 0.16 BN1 only 76.00 A A Example 30 A-3 15.04 B-1 8.80 PPh3 0.16 BN1 only 76.00 A A Example 31 A-3 12.85 B-2 10.99 PPh3 0.16 BN1 only 76.00 A A Example 32 A-3 12.23 B-3 11.61 PPh3 0.16 BN1 only 76.00 A A Example 33 A-4 13.31 B-1 10.53 PPh3 0.16 BN1 only 76.00 A A Example 34 A-4 11.06 B-2 12.78 PPh3 0.16 BN1 only 76.00 A A Example 35 A-4 10.44 B-3 13.40 PPh3 0.16 BN1 only 76.00 A A Example 36 A-2 12.19 B-1 10.65 PPh3 0.16 BN1/AA-3/AA-04 =84/11/5 77.00 A A Example 37 A-2 11.66 B-1 10.18 PPh3 0.16 BN1/AA-3/AA-04 =77/16/7 78.00 A A Example 38 A-2 11.13 B-1 9.71 PPh3 0.16 BN1/AA-3/AA-04 =70/21/9 79.00 A A Example 39 A-2 10.59 B-1 9.25 PPh3 0.16 BN1/AA-3/AA-04 =58/29/13 80.00 A A Example 40 A-2 12.73 B-1 11.11 PPh3 0.16 BN1/SP-3 =99/1 76.00 A A Example 41 A-2 12.73 B-1 11.11 PPh3 0.16 BN1/SP-3 =95/5 76.00 A A Example 42 A-2 12.73 B-1 11.11 PPh3 0.16 BN1/SP-3 =90/10 76.00 A A Example 43 A-2 12.73 B-1 11.11 PPh3 0.16 BN1/BN12 =90/10 76.00 A A Example 44 A-2 12.73 B-1 11.11 PPh3 0.16 BN1/SP-3 =85/15 76.00 A A Example 45 A-2 10.47 B-2 13.37 TOTP 0.16 BN1 only 76.00 A A Example 46 A-2 10.47 B-2 13.37 TPP-MK 0.16 BN1 only 76.00 A A+ Comparative Example 5 A-2 12.73 B-1 11.11 PPh3 0.16 BNb1 76.00 C C Comparative Example 6 A-2 12.73 B-1 11.11 PPh3 0.16 BNb2 76.00 C C Comparative Example 7 A-2 12.73 B-1 11.11 PPh3 0.16 BNb3 76.00 D D Comparative Example 8 A-2 12.73 B-1 11.11 PPh3 0.16 BNb4 76.00 C C

From the results shown in the table, it was confirmed that a thermally conductive material excellent in thermal conductivity and peel strength can be obtained by using the composition containing the modified boron nitride particles of the present invention.

Among them, it was confirmed that the effect of the present invention is more excellent when the modified boron nitride particles are modified boron nitride particles as surface modified boron nitride particles (see the comparison of the results of Example 13 and Example 24, etc. ). It was confirmed that when the carbon atom concentration on the surface of the modified boron nitride particles exceeds 3.0 atom%, the effect of the present invention is more excellent (see the comparison of the results of Example 13 and Example 24, etc.).

It was confirmed that the effect of the present invention is more excellent when the standard redox potential of the oxidizing agent used in the production of modified boron nitride particles is 1.50 V or more (refer to the comparison of the results of Example 13 and Example 21, etc.) . It was confirmed that the effect of the present invention is more excellent when the boron nitride particles are brought into contact with an oxidizing agent in an aqueous solution exceeding pH 13 in the production of modified boron nitride particles (refer to Example 13, Example 17, and Example 20). comparison of results, etc.). It was confirmed that the effect of the present invention is more excellent when the contact angle between the modified boron nitride particles and water is less than 75° (refer to the comparison of the results of Example 13, Example 17, Example 20, and Example 21, etc.) .

It was confirmed that the effect of the present invention is more excellent when the change rate of the median diameter in the production of modified boron nitride particles is less than 10% (refer to the comparison of the results of Example 13 and Example 22, etc.).

It was confirmed that when the compressive fracture strength of the modified boron nitride particles is 5.0 MPa or less, the effect of the present invention is more excellent (see the comparison of the results of Example 13 and Example 23, etc.).

without.

Claims (22)

A method for producing modified boron nitride particles, comprising a modification step of contacting the boron nitride particles with an oxidizing agent in an aqueous solution of pH 12 or higher to obtain modified boron nitride particles. The method for producing modified boron nitride particles according to claim 1, wherein: The pH of the aforementioned aqueous solution exceeds 13. The method for producing modified boron nitride particles according to claim 1 or claim 2, wherein, The standard redox potential of the aforementioned oxidizing agent is 1.50V or more. The method for producing modified boron nitride particles according to claim 1 or claim 2, wherein, The aforementioned oxidizing agent is persulfate. The method for producing modified boron nitride particles according to claim 1 or claim 2, wherein, The change rate of the median diameter is less than 10% calculated from the following formula, Formula: Change rate of median diameter (%)=[1-(median diameter of modified boron nitride particles produced)/(median of boron nitride particles used in the production of modified boron nitride particles) value diameter)] × 100. The method for producing modified boron nitride particles according to claim 1 or claim 2, comprising an adsorption step, wherein the adsorption step is performed in the modification step in the presence of at least one of water and an organic solvent The aforementioned modified boron nitride particles obtained in the above-mentioned modified boron nitride particles are contacted with a surface modification agent to obtain modified boron nitride particles modified with the aforementioned surface modification agent. A modified boron nitride particle, the oxygen atomic concentration on the surface detected by X-ray photoelectron spectroscopy analysis exceeds 5.0 atom%, the contact angle with water is 90° or less, and is obtained by the following formula (1) The obtained D value is 0.010 or less, formula (1): D value=B(OH) ₃ (002)/BN(002), B(OH) ₃ (002): obtained from the measurement by X-ray diffraction Peak intensity of the (002) plane of boron hydroxide of triclinic space group, BN(002): (002) from boron nitride with hexagonal space group measured by X-ray diffraction The peak intensity of the surface. The modified boron nitride particles according to claim 7, wherein, The concentration of carbon atoms on the surface detected by X-ray photoelectron spectroscopy was over 3.0 atom%. The modified boron nitride particles according to claim 8, wherein, The aforementioned carbon atom concentration is 6.0 atom% or more. The modified boron nitride particles according to any one of claim 7 to claim 9, wherein, The aforementioned D value is 0.007 or less. The modified boron nitride particles according to any one of claim 7 to claim 9, which are aggregated particles. The modified boron nitride particles according to claim 11, wherein, The compressive rupture strength is 5.0 MPa or less. The modified boron nitride particles according to any one of claim 7 to claim 9, wherein, The median diameter is 10 μm or more. A composition for forming a thermally conductive material, comprising: The modified boron nitride particles obtained by the method for producing modified boron nitride particles according to any one of claim 1 to claim 6, and the modified boron nitride particles as claimed in any one of claim 7 to claim 13 A modified boron nitride particle of any of the modified boron nitride particles described above; and Resin binders or their precursors. The composition for forming a thermally conductive material according to claim 14, wherein, The aforementioned resin binder or its precursor contains an epoxy compound. The composition for forming a thermally conductive material according to claim 14 or claim 15, wherein, The aforementioned resin binder or its precursor includes an epoxy compound and a phenol compound. The composition for forming a thermally conductive material according to claim 14 or claim 15, further comprising a hardening accelerator. The composition for forming a thermally conductive material according to claim 17, wherein, The aforementioned hardening accelerators include compounds containing phosphorus atoms. The composition for forming a thermally conductive material according to claim 17, wherein, The aforementioned hardening accelerator contains a phosphonium salt. A thermally conductive material obtained by hardening the composition for forming a thermally conductive material according to any one of Claims 14 to 19. A thermally conductive sheet is formed of the thermally conductive material as described in claim 20. An element with a thermally conductive layer, which has an element and a thermally conductive layer disposed on the aforementioned element and comprising the thermally conductive sheet described in claim 21.