Thermally conductive material and its manufacturing method

Abstract

To provide a thermal conductor capable of realizing high thermal conductivity.SOLUTION: The present invention is a thermal conductive material formed by dispersing a filler containing spherical particles made of aluminum nitride and plate-like particles made of boron nitride dispersed in a matrix made of a resin. A volume ratio of plate-like particles to spherical particles is, for example, 0.4-1.5. A particle size ratio of the plate-shaped particles to the spherical particles is, for example, 0.05-0.5. The volume ratio of the filler to the total thermal conductive material is, for example, 73-93 vol.%. A thermal conductive material that satisfies such conditions can exhibit remarkably high thermal conductivity. The thermal conductive material is obtained, for example, through a preparation step of obtaining a mixture in which the spherical particles, the plate-like particles, and the resin are mixed, and a molding step in which the mixture is converted into a molded body. The preparation process may be divided into multiple stages.SELECTED DRAWING: Figure 2A

Description

[Technical Field]

[0001] The present invention relates to a thermally conductive material and the like. [Background technology]

[0002] As elements, devices, and equipment become more dense and perform better, they generate more heat, and sufficient heat dissipation is required to ensure their functionality and lifespan. For example, in the case of electronic devices (semiconductor modules, etc.), heat is dissipated through heat dissipation materials with excellent thermal conductivity (heat sinks, housings, thermally conductive sheets, etc.). In addition to simple metals, composite materials with excellent formability are often used as heat dissipation materials. Composite materials typically consist of a filler with excellent thermal conductivity and a matrix that holds the filler (for example, a resin containing elastomers, rubber, etc.).

[0003] Ceramic particles (including fibers) such as silica (SiO2), alumina (Al2O3), and aluminum nitride (AlN) have been used as fillers. Recently, boron nitride (BN) particles, which have excellent thermal conductivity, electrical insulation, and chemical stability, have also been used as fillers. Boron nitride exists in a hexagonal normal-pressure phase (referred to as "h-BN") and a cubic high-pressure phase (referred to as "c-BN"), but h-BN particles are usually used as fillers. h-BN particles are plate-shaped (flat or scale-like) particles composed of stacked hexagonal mesh layers similar to graphite. The thermal conductivity in the plane direction (a-axis (100) direction) is greater than the thermal conductivity in the thickness direction (c-axis (002) direction) (thermal conductivity anisotropy).

[0004] In addition to fillers consisting of a single type of particle, fillers consisting of a mixture of multiple types of particles are also used. Composite materials in which such fillers are held in a matrix have also been proposed, as described in the following patent documents, for example. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2008-106231 [Patent Document 2] Patent Publication No. 2011-184507 [Patent Document 3] Patent Publication No. 2019-38912 Summary of the Invention [Problem to be solved by the invention]

[0006] Patent Document 1 proposes an adhesive sheet (composite material) for electronic devices in which a powder (filler) made by simply mixing boron nitride powder and spherical alumina powder is mixed in an epoxy resin (matrix) (

[0056] , Example 9 in Table 1). The thermal conductivity of this material is only 3.6 W / mK at most.

[0007] Patent Document 2 proposes a sheet (composite material) in which a powder (filler) made by simply mixing alumina, boron nitride, and aluminum nitride is mixed in a silicone resin (matrix) (

[0027] , Table 4). The thermal conductivity of this sheet is only 7.2 W / mK at most.

[0008] Patent Document 3 proposes a thermally conductive foam sheet that has heat dissipation properties in addition to the flexibility required for impact absorption and sealing properties. The sheet is made of a foamed ethylene propylene diene rubber in which plate-like fillers made of boron nitride and spherical fillers made of magnesium oxide are dispersed. As is clear from the examples in Patent Document 3, when the average length (B) of the plate-like filler is greater than the average particle size (C) of the magnesium oxide (for example, when B / C = 2), the thermal conductivity of the sheet increases both before and after foaming.

[0009] The present invention has been made in view of the above circumstances, and has an object to provide a new thermally conductive material and the like. [Means for solving the problem]

[0010] As a result of intensive research into solving this problem, the inventors have discovered that a thermally conductive material in which the filler dispersed in the resin (matrix) satisfies certain conditions exhibits a peak in thermal conductivity. By expanding on this finding, the present invention, which will be described below, has been completed.

[0011] <Thermal Conductive Material> The present invention is a thermally conductive material comprising a filler including spherical particles of aluminum nitride and plate-like particles of boron nitride dispersed in a matrix made of resin, wherein the volume ratio of the plate-like particles to the spherical particles is 0.4 to 1.5, the particle size ratio of the plate-like particles to the spherical particles is 0.05 to 0.5, and the volume proportion of the filler to the entire thermally conductive material is 73 to 93% by volume.

[0012] The thermally conductive material of the present invention can exhibit excellent thermal conductivity. While the reason for this is unclear, it is believed to be as follows: When spherical particles made of aluminum nitride and plate-like particles made of boron nitride satisfy certain conditions, the plate-like particles, which have excellent flexibility and lubricity (low friction, slidability), are densely interposed between the spherical particles, improving the filler's packing ability and the moldability of the thermally conductive material. This results in a dense thermally conductive material with few voids, increasing the opportunities for contact between the spherical particles and the plate-like particles and between the plate-like particles, resulting in sufficient formation of heat conduction paths and improving the thermal conductivity of the thermally conductive material. Furthermore, it is believed that the substantially uniform arrangement of small plate-like particles around relatively large spherical particles facilitates the expression of substantially isotropic thermal conductivity.

[0013] <<Method for manufacturing thermally conductive material>> The present invention can also be understood as a method for producing a thermally conductive material. For example, the present invention may be the above-mentioned method for producing a thermally conductive material, comprising a preparation step of obtaining a mixture of spherical particles made of aluminum nitride, plate-like particles made of boron nitride, and a resin, and a molding step of forming the mixture into a molded product.

[0014] <Heat conduction material> The present invention can also be understood as a thermally conductive member. The thermally conductive member may be, for example, a raw material (bulk material) before processing, or a product (heat dissipation member, substrate, case, sheet, film, etc.) that has been formed or processed into a desired shape. In this specification, the term "thermally conductive material" includes such thermally conductive members.

[0015] "others" Unless otherwise specified, "x to y" in this specification includes a lower limit value x and an upper limit value y. Any numerical value included in the various numerical values ​​or numerical ranges described in this specification may be used as a new lower limit or upper limit value to create a new range such as "a to b." Unless otherwise specified, "x to y μm" in this specification means x μm to y μm. The same applies to other unit systems (W / mK, Ωm, etc.). [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a schematic diagram showing an example of a manufacturing process for a thermally conductive material (sample). FIG. [Figure 2A] 1 is an SEM image of a cross section of Sample 33. [Figure 2B] 1 is an SEM image of a cross section of sample C31. [Figure 2C] 1 is an SEM image of a cross section of sample C32. [Figure 3A] FIG. 2 is a scatter diagram showing the relationship between the volume ratio of filler (plate-like particles / spherical particles) and the thermal conductivity of the thermally conductive material. [Figure 3B] FIG. 2 is a scatter diagram showing the relationship between the particle size ratio (plate-like particles / spherical particles) of the filler and the thermal conductivity of the thermally conductive material. DETAILED DESCRIPTION OF THE INVENTION

[0017] One or more components arbitrarily selected from this specification may be added to the components of the present invention. The contents described in this specification may apply not only to thermally conductive materials but also to their manufacturing methods. Even method-related components may be considered to be product-related components. Which embodiment is best depends on the target, required performance, etc.

[0018] Filler The filler contains at least spherical particles of aluminum nitride (also referred to as "AlN particles") and plate-like particles of boron nitride (also referred to as "BN particles"), which are primarily hexagonal boron nitride (h-BN).

[0019] (1) Particle shape The spherical particles may be substantially spherical. The term "substantially spherical" refers to a particle having a circularity of 0.6 or more, or even 0.7 or more, as determined from an observation image (e.g., an SEM image) of the particle. The theoretical upper limit of the circularity is 1, but the practical upper limit is 0.98 or less.

[0020] Circularity is calculated from the maximum length of a particle (L / particle size) and its area (S), as follows: 4S / πL 2 Specifically, it can be determined by processing the observed image using software (such as ImageJ). Usually, the arithmetic mean value of the circularity determined for multiple particles within the field of view (650 μm × 450 μm) can be used as the "circularity."

[0021] The plate-like particles may be flat. "Flat" refers to, for example, an aspect ratio (L / t), which is the ratio of the maximum length (L / particle diameter) of the particle to the minimum length (t / thickness) of the particle, of 3 to 300 (or even 20 to 200). The minimum length (t) and maximum length (L) of the particle are determined from the above-mentioned observation image. Usually, the arithmetic mean value of the aspect ratios determined for multiple particles within the above-mentioned field of view can be used as the "aspect ratio (AR)."

[0022] (2) Particle size Regardless of particle shape, the size of a particle is called the "particle size." The "particle size" is indicated, for example, by the maximum length (L) of the particle. The average value of the maximum lengths (L) determined for multiple particles can also be used as the "particle size." In this case, for example, the arithmetic mean value of the particle size of each particle within the field of view (650 μm × 450 μm) of the observation image described above can be used as the "particle size." In this way, the "particle size" can be determined for particles contained in a thermal conductive material (composite material) or particles separated or extracted from a thermal conductive material.

[0023] When the particles are in the stage of raw material powder, the 50% diameter (D50: median diameter) determined from the particle size distribution obtained by laser diffraction may be used as the "particle size" in this specification. Furthermore, the nominal value (catalog value) for the raw material powder may be used as the "particle size" in this specification.

[0024] (3) Particle size ratio The ratio of the particle size (L2) of the plate-like particles to the particle size (L1) of the spherical particles (particle size ratio: L2 / L1) is, for example, 0.05 to 0.5, 0.08 to 0.35, 0.15 to 0.3, or 0.18 to 0.25. If the particle size ratio is too small or too large, the thermal conductivity of the thermal conductive material may decrease.

[0025] The specific "particle size" itself is not important as long as the particle size ratio is within a predetermined range. Specifically, the particle size of the spherical particles is, for example, 10 to 200 μm, 20 to 150 μm, 35 to 120 μm, or 40 to 95 μm. The particle size of the plate-like particles is, for example, 2 to 100 μm, 4 to 75 μm, 8 to 50 μm, or 15 to 35 μm.

[0026] (4) Volume ratio The ratio of the total volume (V2) of the plate-like particles to the total volume (V1) of the spherical particles (volume ratio: V2 / V1) is, for example, 0.4 to 1.5, 0.5 to 1.4, or 0.6 to 1.2. If the volume ratio is too small or too large, the thermal conductivity of the thermal conductive material may decrease. Furthermore, if the volume ratio is too large, the amount of plate-like particles may increase, which may increase the cost of raw materials.

[0027] The volume of a particle is calculated from its mass (content) and true density. For example, if the particle is contained in a thermal conductive material, the volume is calculated from the mass and true density of the separated / extracted particle. If it is at the raw powder stage, the particle volume is calculated from the compound mass and true density.

[0028] (5) Other particles The filler may contain one or more types of particles other than the above-mentioned particles (AlN particles and BN particles). Examples of such particles include aluminum oxide (Al2O3, etc.), silicon oxide (SiO2, etc.), and cubic boron nitride (c-BN). In addition, in thermally conductive materials used in electronic devices, it is preferable that all particles are made of non-conductive materials (insulating materials).

[0029] (6) Surface treatment The filler may be entirely or partially surface-treated to enhance its affinity with the matrix, which improves the dispersibility, packing ability, and adhesion of the filler in the matrix, thereby improving the thermal conductivity of the thermally conductive material.

[0030] The surface treatment is, for example, a hydrophobic treatment or a coupling treatment. Specifically, it includes a silane coupling treatment and a fluorine plasma treatment. The surface treatment may be performed directly on the filler before mixing (including kneading), or may be performed by adding a surface treatment agent (such as a coupling agent) when mixing (kneading) the matrix and the filler.

[0031] "matrix" The filler is dispersed and held substantially uniformly in a matrix made of resin. The resin (including rubber, elastomer, etc.) may be a thermosetting resin or a thermoplastic resin. The thermosetting resin may be subjected to a heat curing treatment (curing treatment) as appropriate.

[0032] Examples of thermosetting resins include epoxy resins, phenolic resins, silicone resins, etc. Examples of thermoplastic resins include polystyrene, polymethyl methacrylate, polycarbonate, polyphenylene sulfide, etc. Examples of rubbers include ethylene-propylene-diene rubber (EPDM), butyl rubber, etc.

[0033] 《Filling rate》 The filler is contained in an amount of, for example, 73 to 93 volume %, 75 to 90 volume %, or 77 to 87 volume % of the entire thermal conductive material. If the filler is too little, the thermal conductivity may decrease. If the filler is too much, molding itself becomes difficult. The remainder other than the filler is usually resin (matrix).

[0034] The filler filling rate (volume %) is determined from the amount and density of the raw materials when manufacturing a thermal conductive material. The filler filling rate in a thermal conductive material is determined from the total amount of thermal conductive material and the amount of filler extracted and separated from the thermal conductive material. If the filler cannot be extracted or separated, the filling rate may be determined indirectly or alternatively from an observation image (SEM image, etc.) of the thermal conductive material (cross section).

[0035] 《Manufacturing method》 The thermally conductive material can be obtained, for example, through a preparation step of obtaining a mixture containing at least spherical particles, plate-like particles, and a resin, and a molding step of forming the mixture into a molded body.

[0036] (1) Preparation process The mixing of particles (powder) and resin may be performed in one step or multiple steps. Multiple steps may include, for example, a first mixing step in which a first mixture is obtained by mixing a portion of the particles and / or resin, and a second mixing step in which the remaining particles and / or resin are mixed with the first mixture to obtain a second mixture. In this case, the particles may be divided and mixed, the resin may be divided and mixed, or both may be divided and mixed. The division may involve dividing the mixture into different amounts or different types. For example, in the first mixing step, either spherical particles or plate-like particles may be mixed with a portion of the resin, and in the second mixing step, the other spherical particles or plate-like particles may be mixed with the remaining resin.

[0037] When the amount of resin is divided, the preparation process may be performed by, for example, a first mixing step in which 5 to 25 mass % or even 10 to 20 mass % of the total resin is mixed with each particle (spherical particles and plate-like particles) to obtain a first mixture, and a second mixing step in which the remainder of the total resin is mixed with the first mixture to obtain a second mixture. By performing such a multi-stage preparation process, it becomes easier to obtain a dense thermally conductive material with low porosity, and the thermal conductivity of the thermally conductive material can be improved.

[0038] The mixing is carried out using, for example, a ball mill, a vibration mill, a V-type mixer, or the like. The preparation step (mixing step) may be carried out by adding a solvent or the like to adjust the viscosity of the resin. The solvent or the like may be removed by volatilization or evaporation (drying step). The mixture may be appropriately crushed, pulverized, or the like, and may be subjected to a molding step as a compound. The particle size of the compound may be adjusted to, for example, an average particle size (median diameter: D50) of 5 to 60 μm, or even 15 to 55 μm.

[0039] (2) Molding process The molded body can be obtained, for example, by pressure molding the mixture (compound). The molding pressure is, for example, 10 to 100 MPa, or even 20 to 50 MPa. The molding process may be performed by compression molding, injection molding, transfer molding, or the like.

[0040] The molding process may be cold molding, which is performed at room temperature, or warm molding, which is performed by heating the mixture. Warm molding may be performed, for example, at a temperature at which the resin softens or melts. The warm molding temperature (T) is, for example, −30 to 30° C. (|T−(Ts, Tm)|≦30° C.) or −20 to 20° C. (|T−(Ts, Tm)|≦20° C.) relative to the softening point (Ts) or melting point (Tm) of the resin.

[0041] The molded body (thermal conductive material) may be in the shape of the final product or a shape close to the final product, or may be a material to be processed, an intermediate material, or the like.

[0042] 《Application》 Thermally conductive materials are used as thermally conductive members for, for example, heat dissipation sheets, substrates, cases, etc. The thermal conductivity thereof can be, for example, 10 to 40 W / mK, 15 to 30 W / mK, or 20 to 25 W / mK. The thermal conductivity of the thermally conductive material may be anisotropic or isotropic. If the difference in thermal conductivity between two orthogonal directions is, for example, 6 W / mK or less, 4 mK or less, or even 2 W / mK or less, the applications of the thermally conductive material can be expanded. Thermally conductive materials used in electronic devices, etc., have a specific resistance of, for example, 10 5 ~10 12 Ωm or 10 8 ~10 10 It is preferable that the resistance is Ωm. [Example]

[0043] Various composite materials (thermal conductive materials) in which fillers are dispersed and held in a matrix were produced and their thermal conductivity properties were evaluated. The present invention will be explained in more detail by showing these specific examples.

[0044] Filler The filler was one or more of the following spherical particles and plate-like particles.

[0045] (1) Spherical particles As a spherical particle source, the following aluminum nitride powders were prepared: Each powder consisted of approximately spherical AlN particles (for example, circularity: 0.90). Powder a1: FAN-f50 / D50 manufactured by Furukawa Electronics Co., Ltd.: 50 μm Powder a2: FAN-f80 / D50 manufactured by Furukawa Electronics Co., Ltd.: 90 μm

[0046] (2) Plate-like particles The following boron nitride powders were prepared as the plate-like particle source. Each powder consisted of plate-like (flat / eg, AR: 4 to 18) BN particles. Powder b1: Denka HGP / D50: 5 μm Powder b2: Denka Co., Ltd. GP / D50: 13 μm Powder b3: Denka SGP / D50: 20 μm Powder b4: Momentive PT110 / D50: 40 μm

[0047] "matrix" The matrix used to hold the filler was an epoxy resin (EP-160, a one-component heat-curing epoxy adhesive manufactured by Cemedine Co., Ltd.) This epoxy resin was a highly viscous liquid at room temperature.

[0048] 《Composite material》 (1) Using powder and resin as particle sources, many samples (composite materials) shown in Table 1 were produced. Samples C1 and C31 contained only spherical particles as filler. Sample C32 contained only plate-like particles (powder b3) as filler. The plate-like particles used in samples 41 to 49 were adjusted in particle size.

[0049] For samples using a filler that is a mixture of spherical and plate-like particles, the particle size ratio and volume ratio of the plate-like particles to the spherical particles are also shown in Table 1. The volumes of the spherical and plate-like particles were calculated from the true density of each particle and the blending amount (mass ratio) of the powder that is the particle source.

[0050] (2) Each sample composite was fabricated according to the procedure shown in Figure 1. Specifically, the procedure is as follows:

[0051] In a polypropylene container, 0.04 g of epoxy resin (10% of the total resin amount) was mixed with 1 to 10 cc of solvent (dichloromethane) and 4.4 g of filler (Step I / first mixing step). The mixing was carried out at room temperature using a mixer (Thinky Corporation ARE-310 "Mixer") at 2000 rpm for 0.5 min.

[0052] The obtained kneaded product was placed in a vacuum chamber and vacuum dried (30 minutes) at room temperature (step II / first drying step), thereby obtaining a kneaded product (first mixture) from which the solvent had been evaporated.

[0053] To the kneaded mixture, 0.35 g of epoxy resin (the remainder of the total resin amount) and 1 to 10 cc of solvent (dichloromethane) were added and kneaded (mixed) (Step III / second mixing step). The kneading was carried out at room temperature using the above-mentioned device at 2000 rpm for 0.5 min.

[0054] The obtained kneaded product was placed in a vacuum chamber and vacuum dried (30 minutes) at room temperature (step IV / second drying step), thereby obtaining a kneaded product (second mixture) from which the solvent had been evaporated.

[0055] This kneaded mixture (second mixture) was filled into the cavity of a mold (die) heated by a heater and warm compression molded in one direction (step V / molding step). At this time, the mold temperature was 130°C and the molding pressure was 20 MPa. The pressurized state was maintained for 30 minutes to thermally harden the resin. This resulted in a cylindrical composite (φ14 mm × 20 mm) in which the filler was held by the resin. The softening or melting temperature of the epoxy resin before the molding step was 80°C.

[0056] "observation" Cross sections (planes parallel to the direction of pressure applied during molding) of the composites of Samples 33, C31, and C32 were observed using a scanning electron microscope (SEM). The observed images are shown in Figures 2A to 2C (collectively referred to as "Figure 2"). Figures 2A and 2B show both an overall image and an enlarged image.

[0057] "measurement" (1) Porosity The porosity of each composite sample is also shown in Table 1. The porosity was calculated from the true density (ρ) and theoretical density (ρth) of the composite as {(ρth - ρ) / ρth} x 100(%). ρ was calculated from the measured mass and volume (Archimedes' method) of the composite. ρth was calculated based on the blending ratio and density of the raw materials (particles and resin) used to produce the composite.

[0058] (2) Thermal conductivity The thermal conductivity of each sample composite is also shown in Table 1. The thermal conductivity (λ) was determined using the Nanoflash method (measuring device: NETZSCH LFA447). Specifically, the thermal conductivity was calculated as λ = α·Cp·ρ from the thermal diffusivity (α) measured using the Nanoflash method, the specific heat (Cp) determined using a differential scanning calorimeter (DSC), and the density (ρ) determined using the Archimedes method.

[0059] In this case, a thin plate-shaped sample perpendicular to the axial direction (pressure direction) (referred to as the "perpendicular sample") and a thin plate-shaped sample parallel to the axial direction (referred to as the "parallel sample") were cut out from each composite material, and the thermal conductivity of each sample was determined. However, since there was not much difference in the thermal conductivity of the two samples, only the thermal conductivity obtained from the perpendicular sample is shown in Table 1.

[0060] "evaluation" (1) Volume ratio Figure 3A shows the relationship between the volume ratio and thermal conductivity for Samples 31 to 36, Sample C31, and Sample C32 shown in Table 1. As is clear from Figure 3A, when the filler is composed of spherical particles and plate-like particles and the volume ratio between them is 0.4 to 1.5, the thermal conductivity increases significantly.

[0061] Furthermore, as can be seen from a comparison between Sample 33 and Sample 37, this tendency remained the same even when the particle size ratio or the particle size of the plate-like particles was changed.

[0062] (2) Particle size ratio The relationship between particle size ratio and thermal conductivity is shown in Figure 3B for Samples 41 to 49 listed in Table 1. As is clear from Figure 3B, when the filler is composed of spherical particles and plate-like particles and the particle size ratio between them is 0.05 to 0.5, the thermal conductivity increases significantly.

[0063] (3) Filling rate The filler filling rates are different for Samples 11 to C1, Samples 21 to C2, Samples 31 to C32, and Samples 41 to 49 shown in Table 1. Comparing these, it was found that the above-mentioned tendency (relationship between thermal conductivity and volume ratio or particle size ratio) can occur when the filler filling rate is more than 70% by volume (73% by volume or more).

[0064] (4) Structure / organization The observation image of Sample 33 shown in Figure 2A reveals that the thermally conductive material exhibiting high thermal conductivity has no voids, and plate-like particles bridge between spherical particles to form many thermal conduction paths.

[0065] On the other hand, the observation image of sample C31 shown in Figure 2B reveals that a thermally conductive material consisting only of spherical particles as filler has many voids, resulting in low thermal conductivity.

[0066] Furthermore, the observation image of sample C32 shown in Figure 2C reveals that a thermally conductive material whose filler is made only of plate-like particles has a small porosity but does not improve thermal conductivity.

[0067] From the above, it has become clear that the thermally conductive material of the present invention can exhibit significantly excellent thermal conductivity.

[0068] [Table 1]

Claims

1. A thermally conductive material comprising a filler including spherical particles of aluminum nitride and plate-like particles of boron nitride dispersed in a matrix of resin, the volume ratio of the plate-like particles to the spherical particles is 0.4 to 1.5; the particle size ratio of the plate-like particles to the spherical particles is 0.05 to 0.5; The thermal conductive material has a filler volume ratio of 73 to 93% by volume relative to the entire thermal conductive material.

2. The thermal conductive material according to claim 1, wherein the volume ratio is 0.6 to 1.

2.

3. 2. The thermal conductive material according to claim 1, wherein the particle size ratio is 0.08 to 0.

35.

4. The thermally conductive material according to claim 1 , wherein the resin is a thermosetting resin.

5. a preparation step of obtaining a mixture of spherical particles made of aluminum nitride, plate-like particles made of boron nitride, and a resin; and a molding step of forming the mixture into a molded body, A manufacturing method for obtaining the thermally conductive material according to any one of claims 1 to 4.

6. The preparation step includes a first mixing step of obtaining a first mixture containing 5 to 25% by mass of the entire resin, the spherical particles, and the plate-like particles; a second mixing step of obtaining a second mixture consisting of the first mixture and the remainder of the entire resin; The method for manufacturing a thermally conductive material according to claim 5 , comprising:

7. the resin is a thermosetting resin, The method for producing a thermally conductive material according to claim 5 , further comprising a heat curing step of heating the molded body to cure the resin.

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