Composition and filler mixture

Abstract

One embodiment of the present invention relates to providing a composition having high thermal conductivity and high flowability, and to a mixture of composition or filler. The composition comprises: a thermally conductive filler (A) having a particle size (D50(A)) of 0.05 μm or more but less than 1.0 μm in the particle size distribution curve obtained by laser diffraction, and a thermally conductive filler (B) having a particle size (D90(A)) of 2.0 μm or less in the particle size distribution curve obtained by laser diffraction; and an adhesive component (C); and satisfies the following requirements (1) to (3): Requirement (1): In the thermally conductive filler (B) used in the aforementioned composition, the cumulative amount of pores with a diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less. Requirement (2): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in the aforementioned composition is 1.0 to 100 μm. Requirement (3): The total volumetric particle size (D10(B)) of the thermally conductive filler (B) used in the aforementioned composition is 0.6 μm or more.

Description

[Technical Field]

[0001] One embodiment of the present invention relates to a mixture of components or fillers. [Previous Technology]

[0002] In recent years, with the increasing output and packaging density of semiconductor devices, a series of materials known as thermal interface materials have been increasingly used to dissipate the heat generated by semiconductor devices. Thermal interface materials are materials used to reduce the thermal resistance along the path from which heat generated by semiconductor devices or other heat-generating components dissipates to heat sinks or frames, and they come in various forms such as sheets, gels, and greases. Generally, thermal interface materials are resin compositions in which thermally conductive fillers are dispersed in resins such as polysiloxane resins. The thermally conductive fillers used are silicon dioxide, alumina, and aluminum nitride. In these resin compositions, there is a need to increase the content of thermally conductive fillers to improve thermal conductivity, and methods to improve the filling properties of these fillers are being explored.

[0003] As a means of improving the filling properties of fillers in resin compositions, it is common practice to combine fillers of various particle sizes. When combining fillers of various particle sizes, high filling properties are easily obtained by allowing smaller particles to enter the gaps between larger particles. For example, Patent Documents 1 to 4 describe a composition containing two or more fillers.

[0003] [Previous Technical Documents]

[0003] [Patent Documents]

[0004] Patent Document 1: Japanese Patent Application Publication No. 2017-014445

[0004] Patent Document 2: Japanese Patent Application Publication No. 2010-007039

[0004] Patent Document 3: Japanese Patent Application Publication No. 2009-164093

[0004] Patent Document 4: Japanese International Publication No. 2018 / 131486

[0005] As explained above, in order to obtain high thermal conductivity, the content of thermally conductive fillers can be increased. However, when thermal conductivity is improved solely by increasing the content of thermally conductive fillers, the flowability of the resin composition will decrease. That is, thermal conductivity and flowability can be considered to be in a trade-off relationship.

[0005] Thermal interface materials are often used between heat-generating elements in devices and heat-dissipating components such as heat sinks. There are often small gaps or unevenness between these heat-generating elements and heat-dissipating components. Therefore, thermal interface materials used between heat-generating elements and heat-dissipating components that are required to reduce the thermal resistance between them are required to have fluidity that can fill such gaps or unevenness (and follow such gaps or unevenness).

[0005] However, after careful investigation, the inventors have learned that the conventional compositions described in the aforementioned patent documents 1 to 4 still have room for improvement in terms of the balance between high thermal conductivity and high fluidity.

[0006] One embodiment of the present invention provides a composition having both high thermal conductivity and high fluidity.

[0007] The inventors have conducted careful research and found that the aforementioned problems can be solved according to the following configuration example. The configuration example of the present invention is described below.

[0008] [1] A composition comprising: a thermally conductive filler (A) in which the volumetric 50% of the particle size distribution curve obtained by laser diffraction has a particle size D50(A) of 0.05 μm or more but less than 1.0 μm, and the volumetric 90% of the particle size D90(A) has a particle size of 2.0 μm or less.

[0008] Thermal conductive filler (B), and

[0008] Adhesive component (C);

[0008] And satisfies the following requirements (1) to (3):

[0008] Requirement (1): In the thermally conductive filler (B) used in the aforementioned composition, the cumulative amount of pores with a pore diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less.

[0008] Requirement (2): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in the aforementioned composition is 1.0 to 100 μm.

[0008] Requirement (3): The total volumetric particle size (D10(B)) of the thermally conductive filler (B) used in the aforementioned composition is 0.6 μm or more.

[0009] [2] The composition as described in [1], wherein the ratio of the BET specific surface area SA[m2 / g] of the aforementioned thermally conductive filler (A) to the aforementioned D​​90(A)[μm] (SA / D90(A)) is 4.0 or more.

[0010] [3] The composition as described in [1] or [2], wherein the ratio of the pressured bulk density [g / cm3] of the aforementioned thermally conductive filler (A) to the true density [g / cm3] (pressured bulk density / true density), that is, the ratio of the density ratio Y to the aforementioned D90(A) [μm] (Y / D90(A)) is 0.5 or more.

[0011] [4] The composition as described in any one of [1] to [3], wherein the ratio of the pressurized bulk density [g / cm3] of the aforementioned thermally conductive filler (A) to the true density [g / cm3] (pressurized bulk density / true density), that is, the ratio of the density ratio Y to the product of the BET specific surface area SA [m2 / g] and the aforementioned D90(A) [μm] (Y / (SA×D90(A))) is 0.08 or more.

[0012] [5] The composition as described in any one of [1] to [4], wherein the aforementioned thermally conductive filler (A) is a polyhedral sphere.

[0013] [6] The composition as described in any one of [1] to [5], wherein the D50(A) of the aforementioned thermally conductive filler (A) is 0.05 μm or more and less than 0.6 μm.

[0014] [7] The composition as described in any one of [1] to [6], wherein the ratio of the pressurized bulk density [g / cm3] of the aforementioned thermally conductive filler (A) to the true density [g / cm3] (pressurized bulk density / true density), that is, the ratio of the density ratio Y to the product of the difference between the BET specific surface area SA [m2 / g] and the aforementioned D90(A) [μm] and the aforementioned D50(A) [μm] (SA×(D90(A)-D50(A))) (Y / (SA×(D90(A)-D50(A)))) is 0.14 or more.

[0015] [8] The composition as described in any one of [1] to [7], wherein the total volume percentage of the aforementioned thermally conductive filler (A), thermally conductive filler (B) and adhesive component (C) is 100%.

[0015] The aforementioned thermally conductive filler (A) is prepared in an amount of 1 to 45% by volume.

[0015] The amount of the aforementioned thermally conductive filler (B) is 25 to 90 by volume.

[0016] [9] The composition as described in any one of [1] to [8], wherein the aforementioned thermally conductive filler (A) contains alumina,

[0016] The aforementioned thermally conductive filler (B) contains aluminum nitride or aluminum oxide.

[0017]

[10] A filler mixture comprising: a thermally conductive filler (A) in which the volumetric 50% of the particle size distribution curve obtained by laser diffraction has a particle size D50(A) of 0.05 μm or more but less than 1.0 μm, and the volumetric 90% of the particle size D90(A) has a particle size D90(A) of 2.0 μm or less, and

[0017] Thermal conductive filler (B);

[0017] And satisfy the following requirements (4) to (6):

[0017] Requirement (4): In the thermally conductive packing (B) used in the aforementioned packing mixture, the cumulative amount of pores with a pore diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less.

[0017] Requirement (5): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in the aforementioned filler mixture is 1.0 to 100 μm.

[0017] Requirement (6): The total volumetric particle size (D10(B)) of the thermally conductive filler (B) used in the aforementioned filler mixture is 0.6 μm or more.

[0018]

[11] The filler mixture as described in

[10] , wherein the aforementioned thermally conductive filler (A) contains alumina,

[0018] The aforementioned thermally conductive filler (B) contains aluminum nitride or aluminum oxide.

[0019] According to one embodiment of the present invention, a composition having high thermal conductivity and high fluidity can be provided. [Simplified Explanation of the Diagram]

[0020] Figure 1 is an SEM (Scanning Electron Microscope) image of the thermally conductive filler (A-1) used in the following examples.

[0020] Figure 2 is a SEM image of the thermally conductive filler (A-3) used in the following examples.

[0020] Figure 3 is a SEM image of the thermally conductive filler (A-4) used in the following examples.

Implementation Method

[0021] The following describes in detail the embodiments of the present invention, but the present invention is not limited to the following embodiments.

[0021] In addition, in this specification and the claims, "A to B" which indicates a numerical range means above A and below B.

[0022] Composition

[0022] A composition of one embodiment of the present invention (hereinafter also referred to as "the composition") comprises:

[0022] The thermally conductive filler (A) in the particle size distribution curve obtained by laser diffraction method has a volumetric 50% particle size (D50(A)) of 0.05 μm or more but less than 1.0 μm, and a volumetric 90% particle size (D90(A)) of 2.0 μm or less.

[0022] Thermal conductive filler (B), and

[0022] Adhesive component (C);

[0022] And satisfies the following requirements (1) to (3):

[0022] Requirement (1): In the thermally conductive filler (B) used in this composition, the cumulative amount of pores with a diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less.

[0022] Requirement (2): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in this composition is 1.0 to 100 μm.

[0022] Requirement (3): The particle size (D10(B)) of the total volumetric 10% of the thermally conductive filler (B) used in this composition is 0.6 μm or more.

[0023] 《Packaging Mixture》

[0023] One embodiment of the filler mixture of the present invention (hereinafter also referred to as "the mixture") contains:

[0023] Thermally conductive filler (A) in the particle size distribution curve obtained by laser diffraction method, wherein the particle size distribution curve has a volumetric 50% particle size (D50(A)) of 0.05 μm or more but less than 1.0 μm, and the volumetric 90% particle size distribution curve has a volumetric 90% particle size (D90(A)) of 2.0 μm or less, and

[0023] Thermal conductive filler (B);

[0023] And satisfies the following requirements (4) to (6):

[0023] Requirement (4): In the thermally conductive filler (B) used in this mixture, the cumulative amount of pores with a pore diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less.

[0023] Requirement (5): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in this mixture is 1.0 to 100 μm.

[0023] Requirement (6): The total volumetric particle size (D10(B)) of the thermally conductive filler (B) used in this mixture is 0.6 μm or more.

[0024] The mixture is preferably composed only of the aforementioned thermally conductive filler (A) and thermally conductive filler (B), and satisfies the aforementioned requirements (4) to (6).

[0024] Preferably, this mixture further contains the following adhesive component (C), and is used as a component identical to that of this composition.

[0025] In addition, the specification of thermally conductive fillers (A) and (B) in this composition or mixture means the particle size, pore size, etc. of the thermally conductive fillers (A) and (B) used as raw materials in the preparation of this composition or mixture.

[0025] D10, D50 and D90 in this specification are the particle sizes that accumulate to 10%, 50% and 90% of the volume in the particle size distribution curve obtained by laser diffraction, respectively. Specifically, they are determined by the method described in the following examples.

[0026] 〈Thermal Conductive Filler (A)〉

[0026] The thermally conductive filler (A) is a filler in which the particle size distribution curve obtained by laser diffraction has a volumetric cumulative particle size (D50(A)) of 50% or more and less than 1.0 μm, and the particle size distribution curve has a volumetric cumulative particle size (D90(A)) of 90% or less of 2.0 μm.

[0026] One type of thermally conductive filler (A) may be used, or two or more types may be used that are different in type or particle size.

[0027] The upper limit of the aforementioned D50(A) is less than 1.0 μm, the better is less than 0.8 μm, the more preferably is less than 0.6 μm, the exceptionally good is less than 0.4 μm, the lower limit is above 0.05 μm, and the better is above 0.1 μm.

[0027] Since the thermally conductive filler (A) with D50(A) within the aforementioned range can adequately fill the voids between the thermally conductive fillers (B), it is easy to obtain a composition with both high thermal conductivity and high fluidity. In particular, the thermally conductive filler (A) with D50(A) within the aforementioned range, and further within the aforementioned preferred range, can, in the composition satisfying the aforementioned requirement (1), adequately fill the pores that may exist in the thermally conductive filler (B) by means of the thermally conductive filler (A), thereby suppressing the decrease in fluidity caused by the penetration of the binder component (C) into these pores. Furthermore, since D50(A) is above the aforementioned lower limit, the increase in viscosity of the composition caused by small-particle-size fillers can be suppressed.

[0028] The upper limit of the aforementioned D90(A) is 2.0 μm or less, preferably 1.5 μm or less, and even more preferably 1.0 μm or less. The lower limit is not particularly limited and can be D50(A)[μm] or more.

[0028] D90(A) is within the aforementioned range of thermally conductive filler (A). Considering that the content of agglomerated particles of thermally conductive filler (A) is low and the content of coarse particles is also low, by using thermally conductive filler (A) with D90(A) within the aforementioned range, the voids between thermally conductive fillers (B) can be fully filled, and a composition with high thermal conductivity and high fluidity can be easily obtained.

[0029] The thermally conductive filler (A) preferably satisfies one or more of the following requirements (a1) to (a5), and more preferably satisfies all of the requirements.

[0030] [Requirement (a1)]

[0030] The particle size (D10(A)) of the thermally conductive filler (A) in the cumulative 10% of volume is preferably 0.50 μm or less, more preferably 0.30 μm or less, and even more preferably 0.20 μm or less. There is no particular limitation on the lower limit, for example, it is 0.02 μm or more.

[0030] When D10(A) is within the aforementioned range, a composition with both high thermal conductivity and high fluidity can be easily obtained. In particular, when the thermally conductive filler (A) with D10(A) is within the aforementioned range, in a composition that satisfies the aforementioned requirement (1), the thermally conductive filler (A) can sufficiently fill the pores that may exist in the thermally conductive filler (B), thereby suppressing the decrease in fluidity caused by the penetration of the binder component (C) into these pores. Furthermore, when D10(A) is above the aforementioned lower limit, the increase in viscosity of the composition caused by small-particle-size fillers can be suppressed.

[0031] [Requirement (a2)]

[0031] The ratio of the BET specific surface area SA[m2 / g] of the thermally conductive filler (A) to D90(A)[μm] (SA / D90(A)) is preferably 4.0 or more, particularly 6.0 or more, and even more 30 or more. There is no particular upper limit, such as 50 or less.

[0031] Since the thermally conductive filler (A) of SA / D90 (A) within the aforementioned range can adequately fill the gaps between the thermally conductive fillers (B), it is easy to obtain a composition with high thermal conductivity and high fluidity at the same time.

[0031] Specifically, the SA can be determined by the method described in the following examples.

[0032] [Requirement (a3)]

[0032] In addition, the ratio of the pressurized bulk density [g / cm3] to the true density [g / cm3] of the thermally conductive filler (A), that is, the ratio of the density ratio Y to the aforementioned D90(A) [μm] (Y / D90(A)), is preferably 0.5 or more, particularly 0.6 or more, and even more preferably 1.0 or more. There is no particular upper limit, for example, it is 4.0 or less.

[0032] If the thermally conductive filler (A) contains fewer aggregates and fewer amorphous or fragmented particles, the aforementioned pressurized volumetric density is larger. Therefore, when using the aforementioned thermally conductive filler (A) with a larger pressurized volumetric density to formulate the composition, thermal channels are easily formed in the composition. As explained above, D90(A) is a value that decreases as the content of aggregates decreases. Therefore, Y / D90(A) is a parameter affected by particle shape. By using a thermally conductive filler (A) with Y / D90(A) within the aforementioned range, a composition with high thermal conductivity and high flowability can be easily obtained.

[0032] Specifically, the pressurized volumetric density can be determined by the method described in the following examples.

[0033] The aforementioned true density can be measured using a dry automatic density meter (e.g., the AccuPyc series manufactured by Shimadzu Corporation). In this invention, depending on the type of filler, specifically aluminum oxide, zinc oxide, magnesium oxide, titanium oxide, silicon nitride, aluminum nitride, boron nitride, aluminum hydroxide, magnesium hydroxide, silicon carbide, calcium carbonate, barium sulfate, talc, silicon dioxide, and diamond, the following true density values ​​are used.

[0033] Alumina (3.98 g / cm3), Zinc oxide (5.67 g / cm3), Magnesium oxide (3.65 g / cm3), Titanium oxide (Rutile type: 4.27 g / cm3, Anatase type: 3.91 g / cm3), Silicon nitride (3.17 g / cm3), Aluminum nitride (3.26 g / cm3), Boron nitride (h-BN: 2.27 g / cm3, c-BN: 3.48 g / cm3) m3), aluminum hydroxide (2.42 g / cm3), magnesium hydroxide (2.36 g / cm3), silicon carbide (3.16 g / cm3), calcium carbonate (calcite type: 2.71 g / cm3, aragonite type: 2.93 g / cm3), barium sulfate (4.50 g / cm3), talc (2.7 g / cm3), silicon dioxide (2.17 g / cm3), diamond (3.52 g / cm3).

[0034] [Requirement (a4)]

[0034] The density ratio Y of the thermally conductive filler (A) relative to the product of the specific surface area SA [m2 / g] and the D90 (A) [μm] (Y / (SA×D90 (A))) is preferably 0.05 or more, particularly preferably 0.08 or more, even more preferably 0.09 or more, especially preferably 0.15 or more, and there is no particular upper limit, for example, it is 0.4 or less.

[0034] As explained above, the aforementioned Y / D90 relates to the shape of the thermally conductive filler (A). Furthermore, the aforementioned SA×D90(A) is a parameter qualitatively representing the surface irregularity of the thermally conductive filler (A). For example, the SA×D90(A) value tends to increase for particles with amorphous or broken powder. Since these particles with amorphous or broken powder do not easily fill the voids between the thermally conductive fillers (B), the thermal conductivity or flowability tends to decrease. Therefore, Y / (SA×D90(A)) is a parameter affected by particle shape and particle surface properties. By using a thermally conductive filler (A) with Y / (SA×D90(A)) within the aforementioned range, a composition with both high thermal conductivity and high flowability can be easily obtained.

[0035] [Requirement (a5)]

[0035] The thermally conductive filler (A) is preferably 0.08 or more, more preferably 0.14 or more, even more preferably 0.15 or more, and particularly preferably 0.40 or more. There is no particular upper limit, for example, 0.80 or less.

[0035] The smaller D90(A)-D50(A) is, the sharper the particle size distribution curve (the less agglomeration). SA×(D90(A)-D50(A)) is a parameter affected by particle size, particle size distribution (presence or absence of agglomeration), and particle surface properties. Therefore, Y / (SA×(D90(A)-D50(A))) becomes a parameter that takes into account all factors, including particle size, particle size distribution (presence or absence of agglomeration), particle shape, and particle surface properties. By using a thermally conductive filler (A) with Y / (SA×(D90(A)-D50(A))) within the aforementioned range, a composition with high thermal conductivity and high flowability can be easily obtained.

[0036] . Types of thermally conductive fillers (A)

[0036] There is no particular limitation on the type of thermally conductive filler (A), and examples include: alumina, zinc oxide, magnesium oxide, titanium oxide, silicon nitride, aluminum nitride, boron nitride, aluminum hydroxide, magnesium hydroxide, silicon carbide, calcium carbonate, barium sulfate, talc, silicon dioxide, and diamond. The thermally conductive filler (A) may also be a filler that combines several substances.

[0036] When using this composition or mixture as a thermal interface material, the thermally conductive filler (A) is preferably alumina, silicon nitride, aluminum nitride, boron nitride, or diamond, which have high thermal conductivity. Alumina is particularly preferred from the perspective of ease of handling and cost advantages.

[0037] The thermally conductive filler (A) may also be a filler that has been surface-treated with a surface treatment agent. The surface treatment method may be any known method without particular limitation, and may be carried out by wet or dry methods.

[0037] The aforementioned surface treatment agent may be any known treatment agent, such as a silane coupling agent, without particular limitation. Representative examples of such treatment agents include: alkoxysilanes (e.g., methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, trifluoropropyltrimethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane); silazanes (e.g., tetramethylsilazane, hexamethyldisilazane); cyclic siloxanes (e.g., tetramethylcyclotetrasiloxane, octamethylcyclotetrasiloxane, hexamethylcyclotrisiloxane).

[0037] When using the aforementioned surface treatment agent, the amount used is preferably 0.01 to 2 parts by mass relative to 100 parts by mass of the filler before surface treatment.

[0038] . Shape of thermally conductive filler (A)

[0038] The shape of the thermally conductive filler (A) is not particularly limited, but it is preferably a polyhedral sphere. Furthermore, "polyhedral sphere" means that the thermally conductive filler (A) has at least two planes, and the particle shape or size observed in SEM images is almost uniform. It also refers to spherical particles without planes, amorphous particles observed in SEM images of various shapes or sizes, and particles other than broken particles containing fragmented powder (microparticles). For example, when using alumina particles as the thermally conductive filler (A), polyhedral sphere fillers from the AA series or NXA series manufactured by Sumitomo Chemical Co., Ltd. are preferred, especially those with low agglomeration such as AA03F, NXA100, and NXA150.

[0038] When the thermally conductive filler (A) is a polyhedral sphere, since there are planes on the particle surface, the fillers can contact each other through the planes. Therefore, compared with particles that contact each other through points, the contact area between particles is larger, and the thermal conductivity is easier to improve. Furthermore, it is easy to obtain a composition with high thermal conductivity and high fluidity.

[0039] (Thermal conductive filler (B)>

[0039] The thermally conductive filler (B) as a whole used in this composition or mixture is not particularly limited as long as the following requirements (1) to (3) or the following requirements (4) to (6) are met.

[0039] One type of thermally conductive filler (B) may be used, or two or more types may be used that are different in type or particle size.

[0040] This composition satisfies the following requirement (1), and this mixture satisfies the following requirement (4).

[0040] Requirement (1): In the thermally conductive filler (B) used in this composition, the cumulative amount of pores with a pore diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less.

[0040] Requirement (4): The total amount of pores with a diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, in the thermally conductive filler (B) used in this mixture is 0.05 ml / g or less.

[0041] The aforementioned cumulative amount of fine pores is preferably below 0.04 ml / g, more preferably below 0.03 ml / g, and since the lower the limit, the better, it is preferably 0 ml / g.

[0041] When the cumulative amount of fine pores is within the aforementioned range, the thermally conductive filler (A) can fully fill the fine pores that may exist in the thermally conductive filler (B), thereby suppressing the decrease in fluidity caused by the penetration of adhesive components (C) into these fine pores.

[0042] For example, when the following are used in this composition or mixture: a thermally conductive filler (B) with a pore size of 0.5 μm or less, a pore volume of y ml / g and a true density of ρ1 g / cm3, and a thermally conductive filler (B) with a pore size of 0.5 μm or less, a pore volume of z ml / g and a true density of ρ2 g / cm3, the aforementioned cumulative pore volume is calculated by (y × V1 × ρ1 + z × V2 × ρ2) / (V1 × ρ1 + V2 × ρ2). When the following are used in this composition or mixture: three or more different thermally conductive fillers (B) with pore sizes of 0.5 μm or less are used, the pore volume is calculated in the same manner.

[0043] This composition satisfies the following requirement (2), and this mixture satisfies the following requirement (5).

[0043] Requirement (2): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in this composition is 1.0 to 100 μm.

[0043] Requirement (5): The total volumetric particle size (D50(B)) of the thermally conductive filler (B) used in this mixture is 1.0 to 100 μm.

[0044] Regarding the aforementioned requirements (2) and (5) for D50 (B), from the point of view that it is easy to obtain a composition with high thermal conductivity, it is preferably 3.0 μm or more, more preferably 6.0 μm or more, more preferably 90 μm or less, and more preferably 80 μm or less.

[0045] When two or more thermally conductive fillers (B) with different particle sizes are used in this composition or this mixture, the D50 (B) of the thermally conductive filler (B) used in this composition or this mixture is obtained by multiplying the original data of the particle size distribution of each filler used as thermally conductive filler (B) by the mixing ratio (volume %) of each filler to obtain the apparent particle size distribution, and then summing this apparent particle size distribution to produce the particle size distribution data of the thermally conductive filler (B) as the particle size that accounts for 50% of the volume accumulation in this particle size distribution data.

[0046] This composition satisfies the following requirement (3), and this mixture satisfies the following requirement (6).

[0046] Requirement (3): The total volumetric particle size (D10(B)) of the thermally conductive filler (B) used in this composition is 0.6 μm or more for 10% of the total volumetric particle size.

[0046] Requirement (6): The total volumetric particle size (D10(B)) of the thermally conductive filler (B) used in this mixture is 0.6 μm or more for 10% of the total volumetric particle size.

[0047] Regarding the lower limit of D10(B) in the aforementioned requirements (3) and (6), it is preferably 0.8 μm or more, especially 1.0 μm or more, and the upper limit is usually 30 μm or less, preferably 20 μm or less, especially 10 μm or less.

[0047] When the overall D10 (B) of the thermally conductive filler (B) used in this composition or mixture is within the aforementioned range, the thermal conductivity and flowability brought about by the densest filling can be ensured, and at the same time, the further flowability and thermal conductivity improvement effect after adding the thermally conductive filler (A) can be fully utilized.

[0048] When two or more thermally conductive fillers (B) with different particle sizes are used in this composition or mixture, the D10(B) of the entire thermally conductive filler (B) used in this composition or mixture is calculated from the particle size distribution data of the entire thermally conductive filler (B). Furthermore, the method for preparing the particle size distribution data of the entire thermally conductive filler (B) is the same as that for D50(B).

[0049] There is no particular limitation on the type of thermally conductive filler (B), and examples include: alumina, zinc oxide, magnesium oxide, titanium oxide, silicon nitride, aluminum nitride, boron nitride, aluminum hydroxide, magnesium hydroxide, silicon carbide, calcium carbonate, barium sulfate, talc, silicon dioxide, and diamond. Thermally conductive filler (B) may also be a filler that combines several substances.

[0049] When this composition or mixture is used as a thermal interface material, the thermally conductive filler (B) is preferably alumina, silicon nitride, aluminum nitride, boron nitride, or diamond, which have high thermal conductivity, and is especially preferably alumina or aluminum nitride.

[0050] Similar to thermally conductive filler (A), thermally conductive filler (B) can also be a filler that has undergone surface treatment with a surface treatment agent. The surface treatment method, the type of surface treatment agent, and the amount of surface treatment agent used are the same as those described in the column for thermally conductive filler (A).

[0051] There are no particular restrictions on the shape of the thermally conductive filler (B). From the viewpoint of flowability, true spherical or polyhedral spherical, ellipsoidal, or rounded shapes are particularly preferred. To improve thermal conductivity, cohesive or fragmented, amorphous, or plate-like fillers can be used.

[0052] (Adhesive component (C)>

[0052] The adhesive component (C) can be specifically listed as: the component in which additives are formulated into the resin as needed.

[0052] The adhesive component (C) may be one or more.

[0053] Examples of the aforementioned additives include: hardeners, plasticizers, affinity agents, hardening accelerators, anti-discoloration agents, surfactants, dispersants, coupling agents, colorants, viscosity modifiers, and antibacterial agents. The adhesive component (C) may contain one or more additives.

[0054] The aforementioned resins are not particularly limited, and examples include: polysiloxane resin, epoxy resin, acrylic resin, urethane resin, phenolic resin, curable polyimide resin, curable modified PPE, and curable PPE. The adhesive component (C) may contain one or more resins.

[0054] From the perspective of the mechanical properties of this composition and the durability when this composition is used as a thermal interface material, the resin content in the adhesive component (C) is usually 50 to 100% by volume, and preferably 60 to 95% by volume.

[0055] From the perspective of easily obtaining a composition with excellent heat resistance, the aforementioned resin is preferably a polysiloxane resin. The polysiloxane resin can be a cured polysiloxane resin or a non-cured polysiloxane resin.

[0055] Examples of curable polysiloxane resins include addition-reactive polysiloxane resins and condensation-reactive polysiloxane resins. When hydrolytic fillers such as aluminum nitride are used in thermally conductive fillers (A) or thermally conductive fillers (B), addition-reactive polysiloxane resins are preferred.

[0056] The aforementioned addition reaction type polysiloxane is preferably a resin obtained by crosslinking, for example, an alkenyl polyorganosiloxane (a) and a silanyl polyorganosiloxane (b) through a hydrosilicification reaction using a catalyst (c).

[0056] In addition, polysiloxanes may also be compounds selected from the group consisting of compounds containing alkoxysilanes and dimethylpolysiloxanes.

[0057] . Polyorganosiloxanes (a) with alkenyl groups

[0057] The above polyorganosiloxane (a) having an alkenyl group may be exemplified by a polyorganosiloxane represented by the average composition formula RxjRykSiO[4-(j+k)] / 2.

[0057] One kind or two or more kinds of the polyorganosiloxane (a) may be used.

[0058] Rx is an alkenyl group. The alkenyl group is preferably a group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a 1-butenyl group, and a 1-hexenyl group, and a vinyl group is preferred.

[0058] The number of alkenyl groups in one molecule of the above polyorganosiloxane is preferably 1 or more, and particularly preferably 2 or more.

[0058] In addition, the alkenyl group may be bonded to a silicon atom at the end of the molecular chain, may be bonded to a silicon atom in the middle of the molecular chain, or may be bonded to both. However, from the viewpoints of the curing rate when the composition is cured and the physical properties of the resulting cured product, etc., it is preferably bonded to at least the silicon atom at the end of the molecular chain, and particularly preferably bonded to the silicon atoms at both ends of the molecular chain. 【0XX】Ry is a substituted or unsubstituted monovalent hydrocarbon group containing no aliphatic unsaturated bond.

[0059] The carbon number of Ry is preferably 1 to 12, and particularly preferably 1 to 10.

[0059] Examples of Ry include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, hexyl, octyl, decyl, and dodecyl; cycloalkyl groups such as cyclopentyl, cyclohexyl, and cyclobutyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl; groups in which a part or all of the hydrogen atoms thereof are substituted with halogen atoms such as chlorine, fluorine, and bromine, or cyano groups, such as chloromethyl, trifluoropropyl, chlorophenyl, bromophenyl, dibromophenyl, tetrachlorophenyl, fluorophenyl, and difluorophenyl; cyanoalkyl groups such as α-cyanoethyl, β-cyanopropyl, and γ-cyanopropyl. Among these, alkyl groups and aryl groups are preferred, and methyl and phenyl are particularly preferred.

[0060] j and k are positive numbers satisfying 0 < j < 3, 0 < k < 3, and 1 < j + k < 3, preferably 0.0005 ≦ j ≦ 1, 1.5 ≦ k < 2.4, and 1.5 < j + k < 2.5, and particularly preferably numbers satisfying 0.001 ≦ j ≦ 0.5, 1.8 ≦ k ≦ 2.1, and 1.8 < j + k ≦ 2.2.

[0061] The molecular structure of the aforementioned polyorganosiloxane (a) can be any one of linear, branched, cyclic or three-dimensional network, and the aforementioned polyorganosiloxane (a) can also be a mixture of these.

[0062] From the viewpoint of obtaining a composition having desired physical properties with good workability, etc., the viscosity of the aforementioned polyorganosiloxane (a) at 23 °C is preferably 0.1 to 10 Pa·s.

[0063] . Polyorganosiloxane (b) having a hydrosilyl group

[0063] Examples of the aforementioned polyorganosiloxane (b) having a hydrosilyl group include polyorganosiloxanes represented by the average composition formula Rz m H n SiO [4-(m + n)] / 2.

[0063] One kind or two or more kinds of the polyorganosiloxane (b) can be used.

[0064] Rz is a substituted or unsubstituted monovalent hydrocarbon group without an aliphatic unsaturated bond.

[0064] Examples of Rz include: alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, hexyl, cyclohexyl, octyl; aryl groups such as phenyl, tolyl; aralkyl groups such as benzyl, phenylethyl; groups in which a part or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, chlorine, bromine or cyano groups, such as chloromethyl, bromoethyl, trifluoropropyl, cyanoethyl. Among these, from the viewpoints of ease of synthesis or cost, etc., an alkyl group is preferably used, and a methyl group is particularly preferably used.

[0065] m and n are numbers satisfying 0.5 ≦ m ≦ 2, 0 < n ≦ 2, 0.5 < m + n ≦ 3, and are preferably numbers satisfying 0.6 ≦ m ≦ 1.9, 0.01 ≦ n ≦ 1.0, 0.6 < m + n ≦ 2.8.

[0066] From the viewpoint of easily obtaining a composition having desired physical properties and the physical properties not easily changing over time, etc., the amount of the aforementioned polyorganosiloxane (b) is such that: relative to one vinyl group bonded to a silicon atom of the aforementioned polyorganosiloxane (a), the number of hydrogen atoms bonded to a silicon atom is 0.1 to 2.0, and preferably 0.2 to 1.5.

[0067] . Catalyst (c)

[0067] The aforementioned catalyst (c) can be used without limitation general known platinum-based catalysts, etc. used in the curing of polysiloxane resins.

[0067] Examples of catalysts (c) include: platinum black, platinum tetrachloride, chloroplatinic acid, reactants of chloroplatinic acid with monohydric alcohols, complexes of chloroplatinic acid with alkenes or vinyl siloxanes, and diacetyl acetate platinum.

[0067] The catalyst (c) may be one type or two or more types.

[0068] The amount of platinum in the aforementioned catalyst (c) is only the amount required for curing and can be adjusted appropriately according to the desired curing speed, etc. It is usually 0.1 to 1000 ppm relative to the total of 100 parts by mass of the aforementioned polyorganosiloxanes (a) and (b).

[0069] . Compounds containing alkoxysilyl groups

[0069] From the point of view that it is easy to obtain a composition with excellent workability, the aforementioned alkoxysilicone compound is preferably a compound having at least one alkoxysilicone group represented by the following formula (I) in one molecule.

[0069] -SiR113-z(OR12)z (I)

[0069] In formula (I), R11 is an alkyl group having 1 to 6 carbon atoms, preferably methyl, R12 is an alkyl group having 1 to 6 carbon atoms, preferably methyl, and z is 1, 2 or 3.

[0070] Compounds having the alkoxysilyl group represented by the aforementioned formula (I) can be exemplified by compounds represented by the following formula (1).

[0070] In addition, in the following formula (1), the repeating units of repeating unit number a, repeating units of repeating unit number b, and repeating units of repeating unit number c do not need to be arranged as represented by the following formula (1). For example, there may be repeating units of repeating unit number c between repeating units of repeating unit number a and repeating units of repeating unit number b.

[0071]

[0071] In formula (1), R1 is an alkoxysilyl group having 1 to 4 carbon atoms, R2 is a group having a siloxane unit represented by the following formula (2) or a monovalent hydrocarbon group having 6 to 18 carbon atoms, R3 is a monovalent hydrocarbon group having 1 to 6 carbon atoms or a hydrogen atom, X is a divalent hydrocarbon group having 2 to 10 carbon atoms or a group having 2 to 10 carbon atoms containing an ester bond, a and b are integers of 1 or more, c is an integer of 0 or more, and a+b+c is an integer of 4 or more.

[0072]

[0072] In formula (2), R4 is independently a monovalent hydrocarbon group having 1 to 12 carbon atoms, Y is an alkoxysilyl group having 1 to 4 carbon atoms or an aliphatic unsaturated group, and d is an integer from 2 to 500, preferably an integer from 4 to 400, more preferably an integer from 10 to 200, and especially preferably an integer from 10 to 60.

[0073] The aforementioned compounds containing alkoxysilyl groups can also be exemplified by compounds represented by the following formula (3).

[0073] R21eR22fSi(OR23)4-(e+f) (3)

[0073] In formula (3), R21 is independently an alkyl group having 6 to 15 carbon atoms, R22 is independently an unsubstituted or substituted monovalent hydrocarbon group having 1 to 12 carbon atoms (excluding alkyl groups having 6 to 12 carbon atoms), R23 is independently an alkyl group having 1 to 6 carbon atoms, e is an integer from 0 to 3, preferably 1, f is an integer from 0 to 2, and e+f is an integer from 1 to 3.

[0074] R21 can be exemplified by, for example, hexyl, octyl, nonyl, decyl, dodecyl, and tetradecyl. When the alkyl group of R21 has 6 to 15 carbon atoms, the compound containing alkoxysilyl is liquid at room temperature and easy to handle, and its wettability with thermally conductive filler (A) or (B) is readily improved, which is preferred.

[0075] R22 may include: alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tributyl, etc.; cycloalkyl groups such as cyclopentyl, cyclohexyl, cyclobutyl, etc.; aliphatic unsaturated groups such as vinyl, allyl, etc.; aryl groups such as phenyl, tolyl, xylyl, naphthyl, etc.; aralkyl groups such as benzyl, 2-phenylethyl, 2-methyl-2-phenylethyl, phenylpropyl, etc.; groups in which part or all of the hydrogen atoms of such hydrocarbon groups are replaced by halogen atoms such as chlorine, fluorine, bromine, cyano, etc., such as chloromethyl, trifluoropropyl, 3,3,3-trifluoropropyl, 2-(nonafluorobutyl)ethyl, 2-(heptadecylfluorooctyl)ethyl, chlorophenyl, bromophenyl, dibromophenyl, tetrachlorophenyl, fluorophenyl, difluorophenyl, etc., or cyanoalkyl groups such as α-cyanoethyl, β-cyanopropyl, γ-cyanopropyl, etc., preferably methyl or ethyl.

[0076] R23 can include methyl, ethyl, propyl, butyl, pentyl, hexyl, etc., with methyl and ethyl being preferred.

[0077] In the aforementioned formula (3), compounds in which e is 1 can be listed as follows: C6H13Si(OCH3)3, C10H21Si(OCH3)3, C12H25Si(OCH3)3, C12H25Si(OC2H5)3, C10H21Si(CH3)(OCH3)2, C10H21Si(C6H5)(OCH3)2, C10H21Si(CH3)(OC2H5)2, C10H21Si(CH=CH2)(OCH3)2, C10H21Si(CH2CH2CF3)(OCH3)2.

[0078] The aforementioned compounds containing alkoxysilyl groups can also be listed as, for example, dimethyl polysiloxanes whose molecular chains represented by the following formula (4) are end-capped with alkoxysilyl groups.

[0079]

[0079] In formula (4), R31 is -O- or -CH2CH2-; R32 is independently a non-substituted or substituted monovalent hydrocarbon group, specifically the same group as the group exemplified in R22 of the aforementioned formula (3), among which alkyl, aryl, and especially methyl or phenyl are preferred; R33 is independently an alkyl group having 1 to 6 carbon atoms, preferably methyl, ethyl, propyl, butyl, or hexyl; g is an integer from 5 to 100, preferably 5 to 70, especially 10 to 50, and p is an integer from 1 to 3, preferably 2 or 3.

[0080] In addition, the aforementioned compounds containing alkoxysilyl groups can also be listed as compounds in formula (4) in which one or more methyl groups are replaced by monovalent hydrocarbon groups other than methyl groups.

[0080] The substituent may be a group having 1 to 10 carbon atoms, and specific examples may include: alkyl groups such as ethyl, propyl, butyl, hexyl, octyl, etc.; cycloalkyl groups such as cyclopentyl, cyclohexyl, etc.; aryl groups such as phenyl, tolyl, etc.; aralkyl groups such as 2-phenylethyl, 2-methyl-2-phenylethyl, etc.; halogenated hydrocarbon groups such as 3,3,3-trifluoropropyl, 2-(nonafluorobutyl)ethyl, 2-(heptadecylfluorooctyl)ethyl, p-chlorophenyl, etc.

[0081] The aforementioned compounds containing alkoxysilyl groups can also be listed as, for example, dimethyl polysiloxanes whose molecular chains represented by the following formula (5) are end-capped with alkoxysilyl groups.

[0082]

[0082] In formula (5), R34, R35, R36 and q have the same meaning as R31, R32, R33 and p in each of the aforementioned formulas (4), and h is an integer from 10 to 10,000 mPa·s, preferably from 20 to 5,000 mPa·s, so that the viscosity of the compound represented by formula (5) at 23°C [the viscosity measured at 23°C using a rotational viscometer according to JIS K 6249:2003].

[0083] In addition, the aforementioned compounds containing alkoxysilyl groups can also be listed as compounds in formula (5) in which one or more methyl groups are replaced by monovalent hydrocarbon groups other than methyl groups.

[0083] The substituent can be listed as the same as the substituent of the substituted methyl group in the above formula (4).

[0084] The dimethyl polysiloxanes represented by the aforementioned molecular chain with alkoxysilyl groups at both ends can be exemplified by, for example, dimethyl polysiloxanes with methyl dimethoxy groups at both ends and dimethyl polysiloxanes with trimethoxy groups at both ends.

[0085] . Dimethyl polysiloxane

[0085] The aforementioned dimethyl polysiloxane can be exemplified by linear dimethyl polysiloxanes represented by the following formula (6).

[0086]

[0086] In formula (6), i is an integer from 10 to 10,000 mPa·s, preferably from 20 to 5,000 mPa·s, such that the viscosity of the compound represented by formula (6) at 23°C [the viscosity measured at 23°C using a rotational viscometer according to JIS K 6249:2003].

[0087] In addition, the aforementioned dimethyl polysiloxane can also be listed as: compounds in which one or more methyl groups in the aforementioned formula (6) are replaced by monovalent hydrocarbon groups other than methyl groups. However, the substituted compound has at least one -(Si(CH3)2-O)- structure.

[0087] The substituent can be listed as the same as the substituent of the substituted methyl group in the above formula (4).

[0088] The aforementioned alkoxysilyl-containing compounds or dimethyl polysiloxanes may also be used together with the aforementioned polyorganosiloxanes (a), polyorganosiloxanes (b), or catalysts (c).

[0089] <Composition of this composition and this mixture>

[0089] The proportions of each of the thermally conductive filler (A), thermally conductive filler (B) and adhesive component (C) in this composition are preferably within the following ranges, and the proportions of each of the thermally conductive filler (A) and thermally conductive filler (B) in this mixture are preferably within the following ranges.

[0090] Considering that the thermally conductive filler (B) can be fully filled and the fine pores that may exist in the thermally conductive filler (B) can be fully filled by the thermally conductive filler (A), it is easy to obtain a composition with high thermal conductivity and high fluidity. The amount of thermally conductive filler (A) in this composition is preferably 1% or more, more preferably 2% or more, more preferably 3% or more, more preferably 45% or less, more preferably 40% or less, and more preferably 30% or less, from the perspective that the thermally conductive filler (B) can be fully filled and the fine pores that may exist in the thermally conductive filler (B) can be fully filled by the thermally conductive filler (A), and the composition of adhesive (C) is readily obtained.

[0091] Considering that the thermally conductive filler (B) can be fully filled and the fine pores that may exist in the thermally conductive filler (B) can be fully filled by the thermally conductive filler (A), it is easy to obtain a composition with high thermal conductivity and high fluidity. The amount of thermally conductive filler (A) in this mixture is preferably 2% or more, more preferably 3% or more, more preferably 4% or more, more preferably 55% or less, more preferably 45% or less, and more preferably 35% or less, more preferably 35% or less, from the perspective of being able to fully fill the gaps between the thermally conductive filler (B) and to fully fill the fine pores that may exist in the thermally conductive filler (B) by the thermally conductive filler (A).

[0092] Considering that a composition with high thermal conductivity and high fluidity can be easily obtained, the amount of thermally conductive filler (B) in this composition is typically 25% or more, more preferably 30% or more, and even more preferably 35% or more, and typically 90% or less, more preferably 85% or less, and even more preferably 80% or less, relative to 100% by volume of the total thermally conductive filler (A), thermally conductive filler (B) and binder component (C).

[0093] From the point that the layer obtained from this composition can adequately retain the thermally conductive fillers (A) and (B), the amount of adhesive component (C) in this composition is generally 3% or more, preferably 5% or more, even more preferably 7% or more, generally 40% or less, preferably 37% or less, even more preferably 30% or less, from the perspective that the layer obtained from this composition can adequately retain the thermally conductive fillers (A) and (B), and the adhesive component (C) is 100% or more in total volume.

[0094] <Preparation method of this composition and this mixture>

[0094] This composition can be prepared by mixing the thermally conductive filler (A), the thermally conductive filler (B), and the adhesive component (C) using conventionally known methods. This mixture can be prepared by mixing the thermally conductive filler (A) and the thermally conductive filler (B) using conventionally known methods, and by arbitrarily mixing the aforementioned adhesive component (C).

[0095] The aforementioned mixing method is not particularly limited and can be carried out using a general mixer such as a planetary mixer, a TRIMIX kneader, a three-roll mixer, or a roller mixer.

[0095] Furthermore, during the aforementioned mixing process, each component may be added to a mixer or similar equipment simultaneously or sequentially. There are no particular restrictions on the order of addition.

[0095] Furthermore, the aforementioned mixing can be carried out under heating as needed, or in a gas environment such as an inert gas environment.

[0096] <Uses of this composition, etc.>

[0096] The uses of this composition can be listed as follows: thermal interface material for efficiently dissipating heat from semiconductor components loaded in home appliances, automobiles, (notebook) personal computers, etc. Specific examples include thermal grease, thermal gel, adhesive, semiconductor encapsulant, and primer.

[0097] Furthermore, this composition is also suitable for use in electrical and electronic machines. There are no particular limitations on such electrical and electronic machines, and examples include: rechargeable batteries such as single-cell lithium-ion electrode secondary batteries and stacked fuel cells; electronic circuit boards such as printed wiring boards; various electronic machines that, in addition to PCs / servers that house CPUs that generate a lot of heat, also house power modules, very large-scale integrated circuits (LSI), and optical components (e.g., optical pickup heads or LEDs, organic ELs, laser diodes, LED arrays); CPUs used in home appliances (digital disc players, mobile phones, smartphones, home game consoles, etc.); and industrial machines such as inverters or switching power supplies. Especially in high-performance digital and switching circuits formed with high integrated density, heat removal (heat dissipation) becomes a major factor relative to the performance and reliability of integrated circuits. This component is excellent in heat dissipation and handling even when used in power semiconductor applications such as engine control, power systems, and air conditioning control in transportation machinery. Even when assembled into automotive electronic components such as electronic control units (ECUs) and used in harsh environments, it can achieve excellent thermal conductivity.

[0097] This composition can be configured as an oily (paste), gel, rubber, or other similar form.

[0098] For example, when this composition is used between a heating element such as a device and a heat dissipation component such as a heat sink, this composition can be used directly between the heating element and the heat dissipation component. When the aforementioned adhesive component (C) contains a curable resin, the cured product of this composition can be used between the heating element and the heat dissipation component. In the latter case, this composition can be placed between the heating element and the heat dissipation component and then cured, or the cured product can be placed between the heating element and the heat dissipation component after the composition has been cured.

[0098] Due to the excellent flowability of this composition, even if there are small gaps or unevenness between the heating element and the heat dissipation component, this composition can fill such gaps or unevenness, resulting in a component with excellent heat dissipation. In addition, due to the excellent flowability (softness, conformability) of the hardened form of this composition, even when using the hardened form, the hardened form can fill the aforementioned gaps or unevenness, resulting in a component with excellent heat dissipation.

[0098] Example

[0099] The present invention will be described in more detail below with reference to embodiments, but the present invention is not limited to these embodiments.

[0100] 〈raw materials〉

[0100] In the examples and comparative examples, the raw materials used are the following thermally conductive fillers (A-1) to (A-4), thermally conductive fillers (cA-1) to (cA-2), thermally conductive fillers (B-1) to (B-8), and adhesive components (C-1) to (C-2).

[0101] 〈Thermal conductive fillers (A-1) to (A-4) and thermal conductive fillers (cA-1) to (cA-2)〉

[0101] In the examples and comparative examples, the following thermally conductive fillers (A-1) to (A-4) and thermally conductive fillers (cA-1) to (cA-2) were used. Furthermore, the physical properties of these fillers were measured using the following methods. The results are shown in Table 1. Additionally, the particle shape of these fillers was observed using a scanning electron microscope (SEM) (Hitachi High-Technologies, S-5500).

[0102] . "Thermal Conductive Filler (A-1)": Alumina powder AA03F (manufactured by Sumitomo Chemical Co., Ltd., particle shape: polyhedral spherical (shape shown in Figure 1))

[0102] . "Thermal Conductivity Filler (A-2)": Alumina powder NAX150 (manufactured by Sumitomo Chemical Co., Ltd., particle shape: polyhedral spherical)

[0102] . "Thermal Conductive Filler (A-3)": Alumina powder AKP30 (manufactured by Sumitomo Chemical Co., Ltd., particle shape: amorphous (shape shown in Figure 2))

[0102] . "Thermal Conductive Filler (A-4)": Alumina powder ASFP20 (manufactured by Denka Corporation, particle shape: non-planar spherical (shape shown in Figure 3))

[0102] . "Thermal Conductive Filler (cA-1)": Alumina powder AA03 (manufactured by Sumitomo Chemical Co., Ltd., particle shape: polyhedral spherical)

[0102] . "Thermal Conductive Filler (cA-2)": Alumina Powder, manufactured by Tokuyama Co., Ltd. (Particle shape: polyhedral spherical)

[0103] [Particle Size Distribution]

[0103] 50 mg of each of the aforementioned fillers was added to a solution containing 5 ml of 5% sodium pyrophosphate aqueous solution in 90 ml of water, and the mixture was dispersed using a homogenizer at 200 mA for 3 minutes to obtain a sample. The particle size distribution of the obtained sample was determined using a laser diffraction particle size distribution analyzer (Microtrac BEL Co., Ltd.: MICROTRACK-MT3300EXII). The D10, D50, and D90 of each filler were determined from the obtained particle size distribution curve.

[0104] [BET specific surface area]

[0104] The specific surface area of ​​each filler was determined by using a flow-type surface area automatic measuring device (Shimadzu Corporation: FlowSorb 2300) and the BET method performed by N2 adsorption.

[0105] [Pressurized Volumetric Density]

[0105] 1.5g of filler material was weighed and placed into a mold with a 20mm diameter hole formed by an upper punch, a lower punch, and a concave die. A molded body was obtained by applying pressure of 200kgf / cm² for 1 minute. The mass (w) of the obtained molded body was recorded to four decimal places using a precision balance. Furthermore, on the circular surface of the molded body, at two points near both ends of the circular surface along a straight line passing through the center of the circle, the thickness (t1, t2) of the molded body was measured using a micrometer in units of 1μm. Then, using the mass (w) [g] and thickness (t1, t2) [mm] of the molded body, the pressurized volumetric density was calculated using the following formula.

[0105] It is calculated by pressurized volumetric density [g / cm3]=20×w / ((t1+t2)×π).

[0106] [True Density]

[0106] The true density of each of the aforementioned fillers (A-1) to (A-4), (cA-1) and (cA-2) is set to 3.98 [g / cm3].

[0107] [Table 1]

[0108] 〈Thermal Conductive Fillers (B-1) to (B-8)〉

[0108] In the examples and comparative examples, the following thermally conductive fillers (B-1) to (B-8) were used. In addition, the D10 and D50 of these fillers were measured in the same manner as those of the thermally conductive filler (A), and the amount of fine pores with a pore diameter of 0.5 μm or less was measured by the following method.

[0109] . "Thermal Conductive Filler (B-1)": Aluminum nitride powder (D10=0.6μm, D50=1μm, pore volume of pores with a diameter of less than 0.5μm = 0.07ml / g)

[0109] . "Thermal Conductive Filler (B-2)": Aluminum nitride powder (D10=2.2μm, D50=9μm, pore volume of pores with a diameter of less than 0.5μm = 0.01ml / g)

[0109] . "Thermal Conductive Filler (B-3)": Aluminum nitride powder (D10=19.4μm, D50=30μm, pore volume of pores with a diameter of less than 0.5μm = 0.00ml / g)

[0109] . "Thermal Conductive Filler (B-4)": Aluminum nitride powder (D10=78.9μm, D50=120μm, pore volume of pores with a diameter of less than 0.5μm = 0.00ml / g)

[0109] . "Thermal Conductive Filler (B-5)": Aluminum nitride powder (D10=0.6μm, D50=1μm, pore volume of pores with a diameter of less than 0.5μm = 0.43ml / g)

[0109] . "Thermal Conductive Filler (B-6)": Alumina powder (D10=0.5μm, D50=1μm, pore volume of pores with a diameter of less than 0.5μm = 0.05ml / g)

[0109] . "Thermal Conductive Filler (B-7)": Alumina powder (D10=4.7μm, D50=13μm, pore volume of pores with a diameter of less than 0.5μm = 0.00ml / g)

[0109] . "Thermal Conductive Filler (B-8)": Alumina powder (D10=48μm, D50=75μm, pore volume of pores with a diameter of less than 0.5μm = 0.00ml / g)

[0110] [Determination of the amount of fine pores]

[0110] The packing material to be tested was pretreated by constant-temperature drying at 120°C for 4 hours. Then, a mercury porosimeter (Micromeritics, AutoPore V9620) was used to determine the pore distribution with a diameter of approximately 0.0036 to 200 μm by mercury indentation. The pore diameter was calculated using Washburn's formula. The amount of pores with a diameter of 0.5 μm or less was the total volume of pores with a diameter of 0.5 μm or less per 1 g of packing material, calculated as above.

[0110] Washburn's formula: P×D=-4σcosθ

[0110] P is the pressure, σ is the surface tension of mercury, D is the pore diameter, and θ is the contact angle between mercury and the packing. Furthermore, the surface tension of mercury is set to 480 dynes / cm, and the contact angle between mercury and the packing is set to 140 degrees.

[0111] 〈Adhesive components (C-1) to (C-2)〉

[0111] . "Adhesive component (C-1)": Decyltrimethoxysilane

[0111] . "Adhesive component (C-2)": A mixture obtained by mixing two-terminated vinyl polysiloxane and a polyorganosiloxane with silanium groups at a mass ratio of 97:3, with the addition of 20 ppm of platinum catalyst (platinum 1,2-divinyltetramethyldisiloxane complex) and 300 ppm of 1-ethynyl-1-cyclohexanol (viscosity (25°C): 100 mPa·s).

[0112] 〈Example 1〉

[0112] 21.14 parts by volume of thermally conductive filler (A-1), 5.03 parts by volume of thermally conductive filler (B-1), 52.36 parts by volume of thermally conductive filler (B-2), 2.92 parts by volume of adhesive component (C-1), and 18.55 parts by volume of adhesive component (C-2) were placed in a planetary mixer and mixed at room temperature for 60 minutes to prepare a resin composition. Furthermore, when preparing this resin composition, the specific gravity of thermally conductive filler (A) was set to 3.98 g / cm³, the specific gravity of thermally conductive filler (B) was set to 3.26 g / cm³, and the specific gravity of adhesive component (C) was set to 0.98 g / cm³, and the weight was calculated to achieve the desired volume ratio.

[0113] 〈Examples 2 to 9, Comparative Examples 1 to 6〉

[0113] Except for the types and amounts of raw materials as shown in Table 2, the resin composition was prepared in the same manner as in Example 1.

[0113] In addition, in Table 2, the values ​​in the column for resin composition are expressed in volume parts.

[0114] [Flowability of the components]

[0114] 60g of the obtained resin composition was poured into a 30cc syringe (manufactured by Musashi Engineering Co., Ltd., PSY-30F), and a pressure of 0.62MPa was applied to the piston at 25°C to measure the amount of resin composition extruded per minute (flowability [g / min]).

[0114] In addition, since the resin composition obtained in Comparative Example 4 is relatively hard, it is almost impossible to squeeze out even when pressure is applied by the aforementioned method, so the flowability cannot be measured.

[0115] [Formation of the sheet]

[0115] In the mold: 3g of the obtained resin composition is placed between a Naflon Sheet (manufactured by Nichias Corporation) and a SUS (stainless steel) plate to obtain a laminate, and then hot-molded at 80°C for 1 hour for 1 ton to obtain a sheet with a thickness of 1mm.

[0116] [Thermal conductivity]

[0116] In order to determine the thermal conductivity, the obtained sheet was used and the thermal diffusivity (α), density (ρ) and specific heat (c) were measured by the following methods.

[0116] For the obtained sheet, the thermal diffusivity (α) was measured 10 times (N=10) using a thermal diffusivity measuring device (manufactured by Hitachi High-Tech Science Co., Ltd., ai-Phase Mobile 2), and the average value was obtained.

[0116] The density (ρ) of the sheet was determined using an electronic balance (Mettler Toledo Co., Ltd., XS204V) and the Archimedes method.

[0116] The specific heat (c) of the sheet was then determined using a differential scanning pyrography instrument (Rigaku Corporation, DSC 8230).

[0116] Using thermal diffusivity (α), density (ρ), and specific heat (c), the thermal conductivity (λ) is calculated according to the following formula.

[0116] λ=α×ρ×c

[0117] [Table 2]

[0118] In any of Examples 4 to 6, where the filler filling rate in the resin composition is 86.9% by volume, and in Comparative Examples 4 and 5, the thermal conductivity is good. However, due to the high filler filling rate, the flowability in any resin composition is lower than that in Example 7, where the filler filling rate is approximately 82.5% by volume. However, as in Examples 4 and 5, when using polyhedral spherical thermally conductive fillers (A-1) or (A-2), even with a significantly high filler filling rate, the flowability is high. This can be presumed to be because the thermally conductive fillers (A-1) or (A-2) move relatively smoothly in response to external forces.

Claims

1. A composition comprising: a thermally conductive filler (A) having a volumetric particle size D50(A) of 0.05 μm or more but less than 1.0 μm and a volumetric particle size D90(A) of 2.0 μm or less in a particle size distribution curve obtained by laser diffraction; a thermally conductive filler (B); and an adhesive component (C); wherein, Compared to the total volume percentage of the aforementioned thermally conductive filler (A), thermally conductive filler (B), and adhesive component (C) of 100%, the amount of the aforementioned thermally conductive filler (A) is 1% to 45% by volume, the amount of the aforementioned thermally conductive filler (B) is 25% to 90% by volume, and the amount of the aforementioned adhesive component (C) is 3% to 40% by volume; and the following conditions (1) to (3) are met: Condition (1): In the overall thermally conductive filler (B) used in the aforementioned composition, the cumulative number of pores with a pore diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less; Condition (2): The particle size D50 (B) of 50% of the overall thermally conductive filler (B) used in the aforementioned composition is 1.0 to 100 μm. Requirement (3): The particle size D10 (B) of the total volumetric 10% of the thermally conductive filler (B) used in the aforementioned composition is 0.6 μm or more.

2. The composition as described in claim 1, wherein the ratio of the BET specific surface area SA [m2 / g] of the aforementioned thermally conductive filler (A) to the aforementioned D90 (A) [μm], SA / D90 (A), is 4.0 or more.

3. The composition as described in claim 1, wherein the ratio of the pressurized bulk density [g / cm3] of the aforementioned thermally conductive filler (A) to its true density [g / cm3], i.e., the density ratio Y to the ratio of the aforementioned D90(A) [μm], Y / D90(A), is 0.5 or more.

4. The composition as described in claim 1, wherein the ratio of the pressurized bulk density [g / cm3] of the aforementioned thermally conductive filler (A) to its true density [g / cm3], i.e., the density ratio Y to the ratio of the product of the BET specific surface area SA [m2 / g] and the aforementioned D90(A) [μm], Y / (SA×D90(A)) is 0.08 or more.

5. The composition as described in claim 1, wherein the aforementioned thermally conductive filler (A) is a polyhedral sphere.

6. The composition as described in claim 1, wherein the D50(A) of the aforementioned thermally conductive filler (A) is 0.05 μm or more but less than 0.6 μm.

7. The composition as described in claim 1, wherein the ratio of the pressurized bulk density [g / cm3] of the aforementioned thermally conductive filler (A) to its true density [g / cm3], i.e., the density ratio Y to the ratio of the product of the difference between the BET specific surface area SA [m2 / g] and the aforementioned D90(A) [μm] and the aforementioned D50(A) [μm], SA×(D90(A)-D50(A))), Y / (SA×(D90(A)-D50(A)))), is 0.14 or more.

8. The composition as claimed in claim 1, wherein the aforementioned thermally conductive filler (A) contains alumina and the aforementioned thermally conductive filler (B) contains aluminum nitride or alumina.

9. A filler mixture comprising: a thermally conductive filler (A) having a particle size D50(A) of 0.05 μm or more but less than 1.0 μm in the particle size distribution curve obtained by laser diffraction, and a particle size D90(A) of 2.0 μm or less in the particle size distribution curve of 90% volumetrically obtained by laser diffraction; a thermally conductive filler (B); and a binder component (C); wherein, Compared to the total volume percentage of the aforementioned thermally conductive filler (A), thermally conductive filler (B), and binder component (C) of 100%, the amount of the aforementioned thermally conductive filler (A) is 1% to 45% by volume, the amount of the aforementioned thermally conductive filler (B) is 25% to 90% by volume, and the amount of the aforementioned binder component (C) is 3% to 40% by volume; and the following conditions (4) to (6) are met: Condition (4): In the overall thermally conductive filler (B) used in the aforementioned filler mixture, the cumulative number of pores with a pore diameter of 0.5 μm or less, calculated from the pore diameter distribution measured by a mercury porosimeter, is 0.05 ml / g or less; Condition (5): The particle size D50 (B) of the overall thermally conductive filler (B) used in the aforementioned filler mixture, which accounts for 50% of the total volume, is 1.0 to 100 μm. Requirement (6): The total volumetric particle size D10 (B) of the thermally conductive filler (B) used in the aforementioned filler mixture is 0.6 μm or more.

10. The filler mixture as claimed in claim 9, wherein the aforementioned thermally conductive filler (A) contains alumina and the aforementioned thermally conductive filler (B) contains aluminum nitride or alumina.

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