Thermally conductive composition, thermally conductive member, and heat dissipation structure

Abstract

[Problem] To provide: a thermally conductive composition which has very high thermal conductivity, excellent extrusion workability, excellent filling properties in small-capacity packages, and the like; a thermally conductive member which is composed of the thermally conductive composition; and a heat dissipation structure which uses the thermally conductive member. [Solution] A thermally conductive composition and a use thereof. The present invention is characterized by containing (A) a zinc oxide powder / alumina powder having a particle diameter of 0.1-1.0 [mu] m, (B) an amorphous or the like aluminum nitride powder / alumina powder having a particle diameter of 2.0-29 [mu] m, (C) an amorphous or the like aluminum nitride powder having a particle diameter of 30 [mu] m or more, (D) a spherical aluminum nitride powder having a particle diameter of more than 50 [mu] m, (E) a specific Si-based surface treatment agent, and (F) a matrix polymer, the content of the components (A) to (D) is in the range of 60-90 vol% with respect to the entire solid content in the composition, the content of the component (C) is in the range of 1.0-20.0 vol%, and the content of the component (D) is in the range of 0.0-30.0 vol%.

Description

TECHNICAL FIELD

[0001] The present application relates to a thermally conductive composition having a very high thermal conductivity, and a cured product thereof having a practically sufficient softness and stress relaxation properties, and having a good extrudability, dischargeability from a cartridge or the like, and a work efficiency at the time of coating is also excellent in addition to a filling property in a small capacity package. BACKGROUND

[0002] In recent years, with the high density / high integration of printed circuit boards and hybrid ICs on which electronic components such as transistors, ICs, storage elements, and the like are mounted, and the increase in capacity of secondary batteries (cell type), in order to efficiently dissipate heat generated by electronic / electrical equipment such as electronic components, batteries, and the like, a thermally conductive silicone composition composed of an organopolysiloxane and a thermally conductive filler such as an alumina powder, an aluminum hydroxide powder, a zinc oxide powder, and the like is widely used. The thermally conductive silicone composition is excellent in heat resistance, and even if the thermally conductive filler is formulated at a high concentration and a high volume %, the cured product thereof is rubber-like, and thus is expected to have a certain softness and stress relaxation properties, and to maintain followability and tightness to a heat source in a heat dissipation structure, and to maintain heat dissipation performance.

[0003] In recent years, in order to cope with high heat dissipation, a thermally conductive silicone composition filled with a large amount of a thermally conductive filler has been proposed. However, the thermally conductive fillers such as alumina, aluminum hydroxide powder have limited thermal conductivity, and there is a problem that the thermal conductivity of the composition and the cured product thereof cannot be further improved even if a large amount is formulated. On the other hand, as a thermally conductive filler excellent in thermal conductivity, a boron nitride powder is known (for example, Patent Literature 1 and the like). However, the boron nitride powder has a flat plate-like shape, and the thermal conductivity of the cured product thereof sometimes has anisotropy.

[0004] In this regard, as a thermally conductive filler also excellent in thermal conductivity, an aluminum nitride powder is known. For the aluminum nitride powder, a spherical or amorphous shape is known, and unlike the boron nitride powder, the thermal conductivity of the cured product is not easily anisotropic, and thus a thermally conductive silicone composition in which various aluminum nitride powders and other thermally conductive fillers are combined has been proposed (Patent Literatures 2 to 19).

[0005] However, in the thermally conductive silicone composition in which these thermally conductive fillers are combined, if the thermally conductive filler such as aluminum nitride powder is highly formulated, there is a tendency that the rubber properties derived from the cured product of the high-molecular silicone are impaired, and if the content of the thermally conductive filler is too much, the obtained cured product becomes too hard, resulting in a gap between the heat dissipation object, so that the followability and stress relaxation are impaired, and sometimes sufficient heat dissipation cannot be achieved. That is, in the cured thermally conductive silicone composition, it is an extremely important problem to control the hardness of the thermally conductive and electrically conductive cured product in the realization of heat dissipation. In addition to this, in the case of highly filling the thermally conductive filler such as aluminum nitride powder, there is a tendency that the flowability of the composition itself is impaired, and in the case of attempting to fill into a cartridge and a dispenser or the like to perform a small amount or point coating, sometimes sufficient extrusion amount cannot be ensured, and in particular, filling for the purpose of small capacity packaging becomes difficult, or the workability and coatability after filling are reduced, resulting in reduction of work efficiency. In addition to this, sometimes the thermally conductive filler cannot be uniformly dispersed in the silicone composition, resulting in adverse effects on the expected thermal conductivity, curability, workability at the time of commercial production, and the like. Therefore, the high thermally conductive silicone composition in which the thermally conductive filler such as aluminum nitride powder, in particular, a high thermally conductive silicone composition having a thermal conductivity of 9.0 W / mK or more, still has room for improvement in terms of performance and workability at the time of industrial popularization.

[0006] Note that, in any of the above documents, there is no description or suggestion that the hardness of the cured product is further adjusted by formulating a fatty acid or the like in the silicone composition which is cured by hydrosilylation reaction, and that a heat resistance imparting agent such as a phthalocyanine compound is used in combination. In addition, in Patent Document 20, although a monofunctional trifunctional methylpolysiloxane containing a hydrolyzable group is used in a thermally conductive silicone rubber composition in order to adjust the viscosity or plasticity of the composition, only a substance having a polymerization degree of about 30 is used, and there is no description or suggestion about limiting the polymerization degree to a specific range, in particular, the influence on the extrusion workability, heat aging property of the cured product, and thermal conductivity.

[0007] Prior Art Documents

[0008] Patent Documents

[0009] Patent Document 1: Japanese Patent Application Laid-Open No. 07-330927

[0010] Patent Document 2: International Publication No. 2018 / 016566 (Patent No. 6246986)

[0011] Patent Document 3: Japanese Patent Application Laid-Open No. 2001-002830 (Patent No. 3746915)

[0012] Patent Literature 4: Japanese Patent Application Laid-Open (JP-A) No. 2002-299533 (Patent No. 4574885)

[0013] Patent Literature 5: Japanese Patent Application Laid-Open (JP-A) No. 2001-230353 (Patent No. 4357064)

[0014] Patent Literature 6: Japanese Patent Application Laid-Open (JP-A) No. 2000-063872 (Patent No. 2930298)

[0015] Patent Literature 7: International Publication No. WO 2016 / 190189

[0016] Patent Literature 8: International Publication No. WO 2020 / 262449

[0017] Patent Literature 9: International Publication No. WO 2018 / 074247

[0018] Patent Literature 10: International Publication No. WO 2017 / 203924

[0019] Patent Literature 11: International Publication No. WO 2020 / 137086

[0020] Patent Literature 12: Japanese Patent Application Laid-Open (JP-A) No. 2020-169231 (Patent No. 7027368)

[0021] Patent Literature 13: International Publication No. WO 2021 / 131212

[0022] Patent Literature 14: International Publication No. WO 2020 / 137970

[0023] Patent Literature 15: Japanese Patent Application Laid-Open (JP-A) No. 2020-090584

[0024] Patent Literature 16: International Publication No. WO 2021 / 225059

[0025] Patent Literature 17: International Publication No. WO 2021 / 099507

[0026] Patent Literature 18: International Publication No. WO 2021 / 256391

[0027] Patent Literature 19: International Publication No. WO 2021 / 261958

[0028] Patent Literature 20: Japanese Patent Application Laid-Open (JP-A) No. 2000-256558 (Patent No. 3543663) SUMMARY

[0029] PROBLEMS TO BE SOLVED BY THE INVENTION

[0030] Further, the inventors of the present case have found a new problem with a heat conductive silicone composition cured by hydrosilylation. As described above, if a large amount of a heat conductive silicone composition formulated with a heat conductive filler is cured, the cured product tends to become hard, and high thermal conductivity is often in trade-off relationship with the softness of the cured product. However, even in the case where the hardness and thermal conductivity of the cured product are adjusted to design a heat conductive silicone composition, in the case of a composition having high heat dissipation properties containing a heat conductive filler as described above at a very high volume % (for example, 60 vol% or more with respect to the entire composition (solid content)), the cured product becomes hard and loses softness and rubber elasticity after heat aging, and sometimes the stress relaxation properties, followability in a heat dissipation structure, and adhesion are impaired. Along with this, the originally intended heat dissipation properties sometimes cannot be sufficiently achieved.

[0031] The present application was completed in order to solve the above problems, and aims to provide a heat conductive composition, a heat conductive member composed thereof, and a heat dissipation structure using the same, the heat conductive composition containing a heat conductive filler such as aluminum nitride powder at a very high volume %, and thus having high thermal conductivity, and the heat conductive member composed of the cured product having practically sufficient softness and stress relaxation properties, and being easily extruded from a cartridge or a dispenser, and particularly excellent in filling properties, workability, and coating properties in a small capacity package.

[0032] Solution to the problem

[0033] As a result of diligent research, the inventors of the present application have found that the above problems can be solved by a heat conductive composition characterized by containing:

[0034] (A) at least one heat conductive filler selected from the group consisting of zinc oxide powder and aluminum oxide powder having an average particle diameter in the range of 0.1 to 1.0 μm;

[0035] (B) at least one heat conductive filler selected from the group consisting of amorphous, spheroid, and polyhedral aluminum nitride powder and aluminum oxide powder having an average particle diameter in the range of 2.0 to 29 μm;

[0036] (C) aluminum nitride powder selected from the group consisting of amorphous, spheroid, and polyhedral having an average particle diameter of 30 μm or more;

[0037] (D) aluminum nitride powder having an average particle diameter of more than 50 μm and being spheroid;

[0038] (E) one or more components selected from the group consisting of components (E1) to (E3):

[0039] (E1) a component represented by general formula (1):

[0040] [Chemical Formula 1]

[0041]

[0042] (in the formula, R 1 independently represents a monovalent hydrocarbon group which is unsubstituted or substituted and does not have a carbon-carbon double bond, R 2 independently represents a hydrogen atom, an alkyl group, an alkoxyalkyl group or an acyl group, a is an integer of 5 to 250, and b is an integer of 1 to 3) and has a viscosity of 10 to less than 10,000 mPa・s at 25℃;

[0043] (E2) a siloxane compound represented by General Formula (2):

[0044] R alk R 3 2SiO(R 3 2SiO) c R 3 2Si-R 4 -SiR 3 (3-d) (OR 5 ) d

[0045] (in the formula, R alk is an alkenyl group, R 3 independently represents a monovalent hydrocarbon group which is unsubstituted or substituted and does not have a carbon-carbon double bond, R 4 is an oxygen atom or a divalent hydrocarbon group, R 5 independently represents a hydrogen atom, an alkyl group, an alkoxyalkyl group or an acyl group, c is an integer of 1 to 250, and d is an integer of 1 to 3) and has a viscosity in the range of 10 to 10,000 mPa・s at 25℃, and the molecular chain terminal has an alkenyl group and a hydrolyzable silyl group; and

[0046] (E3) an alkoxysilane having an alkyl group having 6 or more carbon atoms in the molecule or a hydrolytic condensate thereof; and

[0047] (F) one or more base polymers having a viscosity of 10 to 100,000 mPa・s at 25℃,

[0048] and,

[0049] the content of the thermally conductive filler including components (A) to (D) is in the range of 60 to 90% by volume relative to the entire solid components in the composition,

[0050] the content of component (C) is in the range of 1.0 to 20.0% by volume relative to the entire solid components in the composition,

[0051] The content of the component (D) is in the range of 0.0 to 30.0% by volume, relative to the entire solid components in the composition. That is, the composition, although it is a thermally conductive composition containing a thermally conductive filler such as aluminum nitride powder in a large amount (specifically, in the range of 60 to 90% by volume, relative to the entire solid components in the composition) for imparting a high thermal conductivity, by combining the thermally conductive filler having a specific shape and particle diameter in a specific amount range, and containing a specific component (E) which functions as a surface treatment agent, can simultaneously achieve a very high thermal conductivity which has been mostly in a trade-off relationship in the past, and the coatability and workability at the time of extrusion of the composition itself, and, in the case where the composition has a curability, the softness (= rubber properties) thereof can also be achieved. Note that, in the thermally conductive filler containing the above components (A) to (D), substantially no aluminum nitride powder having an average particle diameter of less than 2.0 μm is contained (more specifically, the content of the aluminum nitride powder having an average particle diameter of less than 2.0 μm in the entire thermally conductive filler is less than 0.5% by mass, more preferably less than 0.1% by mass, and particularly preferably less than the detection limit (= 0.0% by mass)).

[0052] Note that the composition can further contain a certain amount of at least one or more fatty acid-based compounds selected from fatty acids, fatty acid esters, and fatty acid metal salts, and a heat resistance imparting agent. In addition, in the preparation of the composition, the base polymer (preferably, an organopolysiloxane) as the main agent of the composition, the thermally conductive filler, and the component (E) which functions as a specific surface treatment agent can be mixed and heated together (basic heating), or the base polymer (preferably, an organopolysiloxane), the thermally conductive filler, and the component (E) can be mixed, and added to the mixture after the basic heating together with other components.

[0053] Effects of the Invention

[0054] According to the present application, a thermally conductive composition which can form a thermally conductive composition or a curable product thereof having a very high thermal conductivity of 9.0 W / mK or more, while having a practically sufficient coatability, softness, and stress relaxation property, and which is easily extruded from a cartridge or a dispenser, and can be filled into a small volume package such as a syringe with relatively high ease, and has excellent workability and coatability, and a thermally conductive member composed of the same, and a heat dissipation structure using the same (particularly, a heat dissipation structure of an electrical / electronic device including a heat dissipation structure of an electrical / electronic component and a heat dissipation structure of a secondary battery) can be provided.

[0055] Note that the cured product of the heat conductive composition according to the present application, by further adding the above-mentioned fatty acid-based compound and heat resistance imparting agent as needed, in addition to having a very high thermal conductivity, can also suppress changes in hardness even when used at high temperatures, and thus the rubber properties at the time of curing are not impaired, and excellent softness and stress relaxation properties can be maintained after heat aging, and in the case of being applied to a heat dissipation object having various shapes, even when used for a long time at high temperatures, peeling or voids (including voids due to partial / temporary peeling from the member, hereinafter the same) from the heat-generating member due to vibration or the like are unlikely to occur, and excellent adhesion and followability can be continuously maintained, and thus has the advantages of not impairing the initial heat dissipation efficiency and being able to be maintained for a long time. Thus, compared to conventional products, has the advantages of excellent work efficiency at the time of extrusion, durability and heat dissipation performance of the heat dissipation member, and can be applied to heat dissipation objects having various shapes, and has the advantages of being unlikely to peel even when assembled / assembled at high temperatures, and being able to be used for heat dissipation processes at high temperatures for a long time. DETAILED DESCRIPTION

[0056] [Heat conductive composition]

[0057] The composition according to the present application is a heat conductive composition containing a base polymer which can be preferably an organopolysiloxane or the like, by using a specific heat conductive filler in combination, containing a specific component which functions as a surface treatment agent, and determining the range of the amount of these heat conductive fillers, and thus has extremely high thermal conductivity and rubber properties in the cured product thereof, and is easily extruded from a cartridge or a dispenser or the like, has excellent filling properties even in small-volume packaging, and has excellent work efficiency at the time of coating. Furthermore, the composition according to the present application can be used as a silicone grease or a gap filler in an uncured state, and can also be a composition having a curing reactivity by hydrosilylation reaction in which the reaction ratio of SiH / alkenyl is specified. In the case where the composition has a curing reactivity, at least one or more selected from a fatty acid, a fatty acid ester, and a fatty acid metal salt (hereinafter sometimes referred to as "fatty acid-based compound") and a heat resistance imparting agent can be contained, and by containing these components, has the advantage that the rubber properties are not impaired even after heat aging of the cured product. In addition, in order to further improve the extrusion workability of the composition, the heat aging properties and the thermal conductivity of the cured product, a component having a specific siloxane polymerization degree can also be selectively used as the following (E1) component.

[0058] More specifically, the composition according to the present application contains:

[0059] (A) at least one heat conductive filler selected from zinc oxide powder and aluminum oxide powder having an average particle diameter in the range of 0.1 to 1.0 μm;

[0060] (B) at least one thermally conductive filler selected from the group consisting of aluminum nitride powder and aluminum oxide powder having an average particle diameter in the range of 2.0 to 29 μm and a shape selected from the group consisting of amorphous, spheroidal, and polyhedral;

[0061] (C) aluminum nitride powder having an average particle diameter of 30.0 μm or more and a shape selected from the group consisting of amorphous, spheroidal, and polyhedral;

[0062] (D) aluminum nitride powder having an average particle diameter of more than 50 μm and a spheroidal shape;

[0063] (E) at least one component selected from the group consisting of components (E1) to (E3):

[0064] (E1) an organic polysiloxane represented by general formula (1):

[0065] [Chemical Formula 2]

[0066]

[0067] (In the formula, R 1 is independently an unsubstituted or substituted monovalent hydrocarbon group having no carbon-carbon double bond, R 2 is independently a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an acyl group, a is an integer of 5 to 250, and b is an integer of 1 to 3) and having a viscosity of 10 to less than 10,000 mPa-s at 25°C;

[0068] (E2) an organic polysiloxane represented by general formula (2):

[0069] R alk R 3 2SiO(R 3 2SiO) c R 3 2Si-R 4 -SiR 3 (3-d) (OR 5 ) d

[0070] (In the formula, R alk is an alkenyl group, R 3 is independently an unsubstituted or substituted monovalent hydrocarbon group having no carbon-carbon double bond, R 4 is an oxygen atom or a divalent hydrocarbon group, R 5 is independently a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an acyl group, c is an integer of 1 to 250, and d is an integer of 1 to 3) and having a viscosity in the range of 10 to 10,000 mPa-s at 25°C, a siloxane compound having an alkenyl group and a hydrolyzable silane group at the molecular chain terminal; and

[0071] (E3) an alkoxysilane having an alkyl group with 6 or more carbon atoms in the molecule or a hydrolytic condensate thereof; and

[0072] (F) one or more base polymers having a viscosity at 25°C in the range of 10 to 1,000,000 mPa-s,

[0073] and,

[0074] The content of the thermally conductive filler containing components (A) to (D) is in the range of 60 to 90 vol% relative to the entire solid components in the composition,

[0075] The content of component (C) is in the range of 1.0 to 20.0 vol% relative to the entire solid components in the composition,

[0076] The content of component (D) is in the range of 0.0 to 30.0 vol% relative to the entire solid components in the composition. Note that the composition can be used in an uncured state or can have curability. Specifically, the above component (F) preferably contains (F0) one or more organopolysiloxanes having a viscosity at 25°C in the range of 10 to 1,000,000 mPa-s, can be one or more organopolysiloxanes selected from (Fl) an organopolysiloxane having no curability group having a carbon-carbon double bond in the molecule and (F2) an organopolysiloxane having a curability group having a carbon-carbon double bond in the molecule, in a composition using the curability of component (F2), can further contain (G) an organohydrogenpolysiloxane and (H) a catalytic amount of a catalyst for a hydrosilylation reaction, and optionally, can be formulated with (K) a heat resistance imparting agent and (J) a fatty acid-based compound. Furthermore, the composition can also contain a hydrosilylation reaction inhibitor, an adhesion promoter, an organic solvent, and other additives. In addition, the composition according to the present application can be a one-component composition or a multi-component composition such as a two-component composition. Hereinafter, each component and the like will be described.

[0077] Hereinafter, the average particle diameter of each component (including spherical or amorphous) of the thermally conductive filler is the cumulative average particle diameter D 50 (median diameter) in the particle size distribution based on volume using a laser diffraction scattering method, and can be measured using a laser diffraction type particle size distribution measuring device commonly used in the field. In addition, based on this principle, the content (vol%) of coarse particles having a certain particle diameter or less can be determined using a laser diffraction type particle size distribution measuring device.

[0078] [Thermally conductive fillers (A) to (D)]

[0079] The components (A) to (D) are thermally conductive fillers for imparting thermal conductivity to the present composition and the thermally conductive member obtained by curing the present composition. Note that in the present application, in order to achieve the technical effects of the present application, these thermally conductive fillers (including individual components) are preferably substantially free of aluminum nitride powder having an average particle diameter of less than 2.0 μm (hereinafter sometimes referred to as "coarse particles"). Here, "substantially free of" means that the content of aluminum nitride powder having an average particle diameter of less than 2.0 μm in the entire thermally conductive filler is less than 0.5% by volume, more preferably less than 0.1% by volume, and particularly preferably less than the detection limit (= 0.0% by volume). On the other hand, in the case where 0.5% by mass or more of aluminum nitride powder having an average particle diameter of less than 2.0 μm is mixed in any one of the components (A) to (D) or another thermally conductive filler, the technical effects involved in the present application can not be achieved in some cases.

[0080] The component (A) is at least one thermally conductive filler selected from the group consisting of zinc oxide powder and aluminum oxide powder, having an average particle diameter in the range of 0.1 to 1.0 μm. The shape thereof is not particularly limited, and examples thereof include spherical, acicular, discotic, rod-like, and amorphous shapes, with spherical and amorphous shapes being preferred. Note that the spherical shape includes polyhedral spherical shapes. In addition, the average particle diameter of the component (A) is preferably in the range of 0.10 to 0.75 μm, and can be in the range of 0.10 to 0.60 μm.

[0081] The component (A) is the thermally conductive filler having the smallest average particle diameter among the thermally conductive fillers involved in the present application, and is added for the purpose of dense packing. By using this component in combination with the following aluminum nitride powder and the like within a certain amount range, it is possible to improve the thermal conductivity of the cured product without impairing the rubber physical properties and workability during extrusion.

[0082] The component (B) is an aluminum nitride powder and an aluminum oxide powder selected from among amorphous, spheroid-like, and polyhedral shapes, with an average particle diameter in the range of 2.0 to 29 μm. The shape of the (B) component is preferably amorphous, excluding spheroid-like and polyhedral shapes. In other words, components having a spheroid-like or polyhedral shape are explicitly excluded from the range of the (B) component. In addition, in the present invention, amorphous means that the particles do not have a definite shape, but have multiple corners or protrusions, and is particularly distinguishable from a symmetrically shaped spheroid or polyhedral shape. Furthermore, spheroid-like means that the particles have few corners, and are smooth, but are distinguishable from the above-mentioned symmetrically shaped spheroid or polyhedral shape because they still have corners or protrusions. In addition, polyhedral shapes are distinguishable from the above-mentioned symmetrically shaped spheroid or polyhedral shape because they do not have a rounded spherical surface. Spheroids are difficult to handle because they do not have corners and have a poor thermal conductivity, and are therefore not preferred. In the present invention, the most preferred (B) component is an aluminum nitride powder and an aluminum oxide powder that is amorphous and has an average particle diameter in the range of 2.0 to 29 μm. In addition, the average particle diameter of the component (B) is preferably in the range of 2.1 to 25 μm, and can be in the range of 2.4 to 15.0 μm. If the type of component (B) is different, or the particle diameter is less than the above-mentioned lower limit, the workability during extrusion is particularly impaired, or it is not possible to obtain a paste-like composition at all, resulting in cases where extrusion from a cartridge or a dispenser becomes difficult.

[0083] The component (C) is an aluminum nitride powder selected from among amorphous, spheroid-like, and polyhedral shapes, with an average particle diameter of 30 μm or more, and is particularly used in combination with the components (A) and (B) within a certain amount range to achieve the technical effects of the invention, particularly to achieve a very high thermal conductivity without causing anisotropy. Note that the upper limit of the average particle diameter of the component (B) is used as the dividing line.

[0084] The shape of the component (C) is preferably amorphous, excluding spheroid-like and polyhedral shapes. Note that "amorphous", "spheroid-like", and "polyhedral" have the same meanings as described above for the component (B), and a component (C) having these shapes is distinguishable in shape from a symmetrically shaped spheroid or polyhedral particle. In the present invention, the most preferred component (C) is an aluminum nitride powder that is amorphous and has an average particle diameter in the range of 30 μm or more. Furthermore, in the present invention, the following component (D) can be used as a large-particle-diameter and spheroid-like aluminum nitride powder, and is preferred.

[0085] The average particle diameter of component (C) is 30 μm or more, can be in the range of 30 to 300 μm, and can be in the range of 30 to 180 μm. Furthermore, as described above, component (C) preferably does not contain aluminum nitride powder having an average particle diameter of less than 2.0 μm, and component (C) in which the amount of these particles is 1% by volume or less, preferably 0% by volume or less with one significant figure, is most preferred. This is because, if the content of aluminum nitride powder having a low particle diameter is large, even if a specific amount of component (C) is used, the workability during extrusion can be impaired due to the influence of the aluminum nitride powder having a low particle diameter, or a paste-like composition cannot be obtained, resulting in cases where extrusion itself becomes difficult.

[0086] Component (D) is aluminum nitride powder having an average particle diameter of more than 50 μm and a spherical shape, and is optional in the present application, but particularly, by using in combination with components (A), (B), and (C) within a certain amount range, the technical effects of the present application are further improved, particularly, the problem of anisotropy does not occur, and a very high thermal conductivity is achieved. Note that component (B) is classified according to the upper limit of the average particle diameter, and component (C) is classified according to the shape.

[0087] The average particle diameter of component (D) is more than 50 μm, can be in the range of 51 to 300 μm, and can be in the range of 51 to 180 μm. Furthermore, component (D) preferably does not contain aluminum nitride powder having an average particle diameter of less than 2.0 μm, and component (D) in which the amount of these particles is 1% by volume or less, preferably 0% by volume or less with one significant figure, is most preferred. The reason is the same as that described in component (C).

[0088] [Other thermally conductive fillers]

[0089] In the composition according to the present application, a thermally conductive filler other than components (A) to (D) described above can be blended. For example, it can be at least one or more powders and / or fibers selected from the group consisting of pure metals, alloys, metal oxides, metal hydroxides, metal nitrides, metal carbides, metal silicides, carbon, soft magnetic alloys, and ferrites other than components (A) to (D), and is preferably a metal-based powder, a metal oxide-based powder, a metal nitride-based powder, or a carbon powder. The shape is not particularly limited, and for example, spherical, needle-like, disc-like, rod-like, amorphous shapes can be mentioned, and spherical and amorphous shapes are preferred. The average particle diameter of the other thermally conductive filler is not particularly limited as long as the conditions regarding components (A) to (D) and the amount range thereof are satisfied, and is preferably in the range of 0.01 to 500 μm, and further preferably in the range of 0.01 to 300 μm.

[0090] The other thermally conductive filler is preferably silver powder, aluminum powder, alumina powder, zinc oxide powder, magnesium oxide powder, aluminum nitride powder, or graphite. Further, in the case where the present composition requires electrical insulation, a metal oxide-based powder or a metal nitride-based powder is preferred, and an alumina powder, a zinc oxide powder, a magnesium oxide powder, or an aluminum nitride powder is particularly preferred. However, the above-mentioned powders are excluded from the components (A) to (D).

[0091] [Amount of the components (A) to (D) and the other thermally conductive filler]

[0092] The present composition can form a cured product having a very high thermal conductivity of 9.0 W / mK or more, while having a practically sufficient softness and stress relaxation properties, and a thermally conductive member composed of the same, and in order to achieve the property of being paste-like after being filled into a cartridge or the like and excellent work efficiency at the time of extrusion, the amount of the components is required to be in a specific range.

[0093] Specifically, in the present application, in order to achieve a high thermal conductivity, the content of the thermally conductive filler containing the components (A) to (D) is in the range of 60 to 90% by volume, preferably in the range of 65 to 90% by volume, in the range of 70 to 90% by volume, or in the range of 75 to 90% by volume, with respect to the entire solid components in the composition. If the content of the thermally conductive filler is less than the above lower limit, the thermal conductivity of the resulting composition tends to decrease, and sometimes a high thermal conductivity of 9.0 W / mK or more, which is targeted in the present application, cannot be achieved. On the other hand, if it exceeds the above upper limit, even in the case where the component (E) described later is blended or surface-treated to the thermally conductive filler, the viscosity of the resulting composition significantly increases, or the initial cured product significantly hardens, and the handling workability and stress relaxation properties or adhesiveness to a substrate, and the like, sometimes decrease.

[0094] Further, the total amount of the thermally conductive filler containing the components (A) to (D) is further preferably in the range of 600 to 6000 parts by mass, and particularly preferably in the range of 800 to 4000 parts by mass, with respect to 100 parts by mass of the component (F) described later. In the case where the amount of the thermally conductive filler is in the above range by volume and the amount of the component (F) satisfies the above range, the problems of the present application can be particularly preferably solved.

[0095] The content of the component (C) is in the range of 1.0 to 20.0% by volume, and more preferably in the range of 2.0 to 20.0% by volume, in the range of 3.0 to 19.0% by volume, with respect to the entire solid components in the composition.

[0096] Since component (D) is an optional component of the present application, it is contained in an amount in the range of 0.0 to 30.0% by volume, preferably in the range of 3.0 to 30.0% by volume, and more preferably in the range of 5.0 to 30.0% by volume, relative to the entire solid components in the composition.

[0097] Further, the content of the amorphous aluminum nitride powder selected from components (B) and (C) is preferably 50% by mass or less, relative to the entire solid components in the composition.

[0098] In addition, the sum of the contents of the thermally conductive fillers which are aluminum nitride powders is particularly preferably 60% by mass or less, relative to the entire solid components in the composition. Aluminum nitride powders are prone to internal cracking due to ammonia gas generated by hydrolysis, and this tendency is significant as the amount of filling increases, so it is desirable to reduce the amount of use as much as possible, which helps to solve this problem.

[0099] In addition, other thermally conductive fillers are sometimes able to improve the filling efficiency by, for example, combining a powder having a large particle size with a powder having a small particle size at a ratio following a distribution curve in accordance with the theory of close packing, in order to improve the filling efficiency, and are able to achieve low viscosity and high thermal conductivity.

[0100] [Other Inorganic Fillers]

[0101] As an arbitrary component of the composition of the present application, for example, an inorganic filler (also referred to as "inorganic filling material") such as fumed silica, wet-process silica, crushed quartz, titanium oxide, magnesium carbonate, zinc oxide, iron oxide, diatomaceous earth, carbon black, and an inorganic filler in which the surface of such an inorganic filler is subjected to hydrophobic treatment using component (E) and / or another organosilicon compound (silazane-based compound, etc.) described later can also be formulated. However, from the viewpoint of taking into account the technical effects of the present application, in particular, the high thermal conductivity and the softness and stress relaxation properties of the cured product, the extrusion workability from a cartridge and the adhesiveness to a substrate, the composition can be one which substantially does not contain a filler other than the thermally conductive fillers containing components (A) to (D). On the other hand, for the purpose of improving (strengthening) mechanical strength, adjusting viscosity, and other functions, the above-described fillers can also be used in a range that does not impair the technical effects of the present application, and are included in one of the preferred embodiments of the present application.

[0102] [Component (E)]

[0103] Component (E) is a component that functions as a surface treatment agent for the above-described components (A) to (D) and other thermally conductive fillers and other inorganic fillers, and can coexist with these components in the composition, and is preferably contained in an amount of 0.1 to 10% by mass, relative to the entire solid components in the composition.

[0104] It is particularly preferable that at least a part of the component (E) is surface-treated with respect to the components (A) to (D) above from the viewpoint of uniform dispersibility of these components and handling properties of the resulting composition and the like. The component (E) is a component selected from one or more of a siloxane compound having a single terminal alkoxyl group (= component (El), (E2)) and / or an alkoxysilane having a long-chain alkyl group (= component (E3)), and more specifically, a component selected from one or more of the following components (El) to (E3). Furthermore, in order to further improve the extrusion workability of the composition, the heat aging properties and the thermal conductivity of the cured product, the component (El) can be used, and particularly, the component (El) having a specific siloxane polymerization degree can be used.

[0105] (E1) is represented by general formula (1):

[0106] [Chemical Formula 3]

[0107]

[0108] (In the formula, R 1 is independently an unsubstituted or substituted monovalent hydrocarbon group having no carbon-carbon double bond, R 2 is independently a hydrogen atom, an alkyl group, an alkoxyalkyl group or an acyl group, a is an integer of 5 to 250, and b is an integer of 1 to 3) having a viscosity of 10 to less than 10,000 mPa-s at 25°C

[0109] In general formula (1), R 1 is independently an unsubstituted or substituted monovalent hydrocarbon group having no carbon-carbon double bond, and as examples thereof, a straight-chain alkyl group, a branched-chain alkyl group, a cyclic alkyl group, an aryl group, an aralkyl group, a halogenated alkyl group can be listed. Industrially, R 1 is preferably a methyl group or a phenyl group, and from the viewpoint of heat resistance, a methyl group is preferred.

[0110] R 2 is independently a hydrogen atom, an alkyl group, an alkoxyalkyl group, an alkenyl group or an acyl group. From the viewpoint of surface treatment, R 2 is preferably an alkyl group, and particularly preferably a methyl group or an ethyl group.

[0111] In general formula (1), a is an integer in the range of 5 to 250, and preferably in the range of 10 to 200. Furthermore, b is an integer of 1 to 3, and preferably 2 or 3. As the component (El) of the present application, it is preferable that, for example, b is 3, a trialkoxysiloxy group is present at a single terminal of the molecular chain, and R 1 is a methyl group.

[0112] Here, when the component (E1) is in the range of a, the silicone polymerization degree, of 40 to 90, the extrusion workability of the composition, the heat aging property of the cured product, and the thermal conductivity can be further improved. Therefore, as the optional configuration of the present application, it is preferable to use an organic polysiloxane in which at least a part of the component (E) contains the component (E1), and the component (E1) is an organic polysiloxane in which a in General Formula (1) is a number in the range of 40 to 90, 45 to 90, 50 to 90, 50 to 80, and b is 3. Further, even in the case of the organic polysiloxane represented by General Formula (1) in which the value of a is not in the above range (for example, a is 30 or 100), compared to the case where the organic polysiloxane in which a is in the above range is used as the component (E1), the extrusion workability of the composition or the heat aging property of the cured product involved in the present application cannot be sufficiently improved.

[0113] (E2) is represented by General Formula (2):

[0114] R alk R 3 2SiO(R 3 2SiO) c R 3 2Si-R 4 -SiR 3 (3-d) (OR 5 ) d

[0115] (in the formula, R alk is an alkenyl group, R 3 independently is an unsubstituted or substituted monovalent hydrocarbon group having no carbon-carbon double bond, R 4 is an oxygen atom or a divalent hydrocarbon group, and R 5 independently is a hydrogen atom, an alkyl group, an alkoxyalkyl group, or an acyl group, c is an integer of 1 to 250, and d is an integer of 1 to 3) having a viscosity at 25°C in the range of 10 to 10,000 mPa・s, and a molecular chain end having an alkenyl group and a hydrolyzable silane group.

[0116] In General Formula (2), R alk is an alkenyl group, and examples thereof include alkenyl groups having 2 to 10 carbon atoms such as a vinyl group, an allyl group, and a hexenyl group. The component (E2) has an alkenyl group at a single end of the molecular chain, and thus can sometimes improve the curability and the adhesion properties when used with other cross-linking agents and the like.

[0117] (in the formula, R 3 independently is an unsubstituted or substituted monovalent hydrocarbon group having no carbon-carbon double bond, and examples thereof include linear alkyl groups, branched alkyl groups, cyclic alkyl groups, alkenyl groups, aryl groups, aralkyl groups, and halogenated alkyl groups. From an industrial viewpoint, the group is a methyl group or a phenyl group, and from the viewpoint of heat resistance, the group is preferably a methyl group. 4is a divalent hydrocarbon group. As the divalent hydrocarbon group of R 4 , methylene and the like alkylene groups; ethyleneoxyethylene, ethyleneoxypropylene and the like alkyleneoxyalkylene groups can be exemplified. On the other hand, R 4 may and preferably is an oxygen atom.

[0118] in the formula, R 5 independently is a hydrogen atom, an alkyl group, an alkoxyalkyl group or an acyl group, preferably an alkyl group, and particularly preferably a methyl group, an ethyl group from the viewpoint of surface treatment. The component (G2) has a hydrolyzable silyl group within the molecule by virtue of the monoterminus structure represented by Si(OR 5 ), and therefore has an excellent surface treatment effect in the case of being used in combination with the component (C).

[0119] c in the formula is the degree of polymerization (excluding the terminal) of the diorganosiloxane unit of the component (E2), and is an integer of 1 to 250, preferably an integer of 1 to 100, and particularly preferably an integer of 1 to 50. d in the formula is an integer of 1 to 3, and preferably 3. In the case where d is 3, the monoterminus of the component (E2) is particularly preferably trimethoxysilyl group (-Si(OMe)3).

[0120] The blending amount of the component (E1) and the component (E2) (total amount in the case of being used in combination) is not particularly limited as long as it is an amount sufficient for the surface treatment of the filler, and as one example, it is in the range of 0.005 to 100 parts by mass, preferably 0.05 to 100 parts by mass, and further preferably 0.5 to 50 parts by mass, relative to 100 parts by mass of the component (F) in the entire composition.

[0121] (E3) an alkoxysilane having an alkyl group having 6 or more carbon atoms within the molecule or a hydrolytic condensate thereof.

[0122] The component (E3), like the components (E1) or (E2), is a component which functions as a surface treatment agent for the thermally conductive filler containing the components (A) to (D) in the composition, and which improves the blending amount thereof, and improves the viscosity and flowability of the entire composition, while improving the adhesion properties. Such an alkoxysilane needs to have an alkyl group of C6 or more, and in the case of using an alkylalkoxysilane having an alkyl group of less than C6 such as a methyl group or a hydrolytic condensate thereof, even if it is used in combination with the adhesion-imparting agent described later, sometimes the adhesion properties cannot be sufficiently achieved.

[0123] As specific examples of the alkyl group having 6 or more carbon atoms, alkyl groups such as hexyl group, octyl group, dodecyl group, tetradecyl group, hexadecyl group, octadecyl group; aralkyl groups such as benzyl group, phenylethyl group and the like can be exemplified, and an alkyl group having 6 to 20 carbon atoms is particularly preferred.

[0124] It is preferred that the component (E3) is an alkoxysilane represented by the following structural formula:

[0125] Y n Si(OR) 4-n

[0126] (in the formula, Y is an alkyl group having 6 to 18 carbon atoms, R is an alkyl group having 1 to 5 carbon atoms, and n is a number of 1 to 3)

[0127] As the OR group, methoxy group, ethoxy group, propoxy group, butoxy group, and the like can be exemplified, and methoxy group and ethoxy group are particularly preferable. Note that n is 1, 2, or 3, and 1 is particularly preferable.

[0128] Such a component (E3) can be exemplified by, specifically, C6H 13 Si(OCH3)3, C8H 17 Si(OC2H5)3, C 10 H 21 Si(OCH3)3, C 11 H 23 Si(OCH3)3, C 12 H 25 Si(OCH3)3, C 14 H 29 Si(OC2H5)3, and the like, and decyltrimethoxysilane is most preferable.

[0129] The blending amount of the component (E3) is not particularly limited as long as it is an amount sufficient for surface treatment of the filler, and as an example, it is in the range of 0.005 to 20 parts by mass, preferably 0.05 to 10 parts by mass, and further preferably 0.5 to 7.5 parts by mass, with respect to 100 parts by mass of the component (F) in the entire composition.

[0130] [Surface treatment of the thermally conductive filler containing components (A) to (D), and other inorganic fillers]

[0131] In the present application, the components (A) to (D) and other thermally conductive fillers, and further the optional inorganic fillers used as needed (hereinafter, these components are collectively referred to as "fillers") are preferably surface-treated with at least a part of the above-described component (E). Further, these fillers can be treated together with these components using various surface treatment agents known as coupling agents. As the surface treatment agent for treating the fillers involved in the present application, in addition to the component (E), surfactants, other silane coupling agents, aluminum-based coupling agents, and silicone-based surface treatment agents, and the like can be exemplified.

[0132] The surface treatment method of the filler from these components is not particularly limited, and direct treatment of the filler, bulk blending, dry concentration, or the like can be used. In the present application, from the viewpoint of improving the filling property of the composition as a whole and the thermal conductivity, rubber properties, and adhesive strength of the cured product, a heating surface treatment method in which a part or all of the component (F) described below is mixed with the component (E) in advance, the filler is sequentially mixed in this mixture, and the mixture is homogenized and then heated (base heating) is most preferably exemplified. The surface treatment method can be heating and stirring the mixture under reduced pressure at 100 to 200°C, and the temperature conditions and stirring time can be designed according to the amount of the sample, and are preferably in the range of 120 to 180°C and 0.25 to 10 hours. Furthermore, the surface treatment step of the filler is optional, but from the viewpoint of improving the extrusion workability and thermal conductivity of the present composition, it can also be a stepwise treatment step including surface treatment of at least a part of the filler by one or more selected from component (E1) and component (E2) in component (E), followed by surface treatment of the filler by component (E3). Furthermore, by using an organopolysiloxane in which component (E1) is included in component (E) and a is a number in the range of 40 to 90 and b is 3 in the above general formula (1), the extrusion workability of the composition can sometimes be particularly preferably improved.

[0133] There is no particular limitation on the device used for the above mixing, and examples that can be exemplified include a single- or double-shaft continuous mixer, a double roll mixer, a Ross mixer, a Hobart mixer, a toothed mixer, a planetary mixer, a kneader, a Henschel mixer, and the like.

[0134] [(F) Base Polymer]

[0135] Component (F) is a base polymer for supporting the above-mentioned thermally conductive filler, and a liquid or a high-molecular material having fluidity that is curable or non-curable and has a viscosity at 25°C in the range of 10 to 1,000,000 mPa・s, preferably in the range of 10 to 10,000 mPa・s, can be used without particular limitation. For example, an organopolysiloxane, a liquid polyurethane resin, a liquid polyester resin, a liquid acrylic resin, a liquid polyol resin, a liquid butadiene rubber, a liquid isoprene rubber, a liquid styrene butadiene rubber, and the like can be used without limitation, but the thermally conductive composition to which the present application relates is applied to semiconductor devices and the like that generate high temperatures, and therefore it is particularly preferable to include one or more organopolysiloxanes that have excellent heat resistance and cold resistance and have a viscosity at 25°C in the range of 10 to 1,000,000 mPa・s, (F0). Furthermore, components belonging to any of the above-mentioned components (E) are explicitly excluded from the range of component (F).

[0136] The organic polysiloxane as the component (F0) is a main agent of the present composition, and is one or more kinds of organic polysiloxane having a viscosity at 25°C in the range of 10 to 1,000,000 mPa-s. The viscosity at 25°C of the component (F) is preferably in the range of 10 to 100,000 mPa-s, and more preferably in the range of 10 to 10,000 mPa-s. If the viscosity of the component (F) is less than 10 mPa-s, the mechanical strength of the obtained organic polysiloxane composition or the cured product thereof tends to decrease, whereas if it exceeds 100,000 mPa-s, the handling workability and the application property to details tend to decrease due to the excessively high viscosity of the obtained composition. Furthermore, from the viewpoint of preventing contact failure and the like, it is preferable to reduce or remove low-molecular-weight siloxane oligomers (octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5)) from the component (F).

[0137] The component (F) can be composed of one or two or more kinds of organic polysiloxanes. The molecular structure of these organic polysiloxanes is not particularly limited, and for example, linear, branched, cyclic, three-dimensional network structure (including so-called resin-like three-dimensional structure), and combinations thereof can be exemplified.

[0138] Depending on the presence or absence of a curable reactive group in the component (F), the present composition can be designed as a curable or non-curable composition. Here, the curable reactive group is a functional group capable of curing the entire composition (including gelation, the same hereinafter) by crosslinking reaction, and the kind thereof is not particularly limited, and is preferably a silicon hydride addition reaction or a radical polymerization reaction, and particularly preferably a curable reactive group having a carbon-carbon double bond within the molecule. In addition, the curable reactive group having a carbon-carbon double bond within the molecule is preferably at least one or more kinds of organic group selected from the group consisting of an alkenyl group, a methacryloyloxy-containing organic group, and an acryloyloxy-containing organic group, and particularly preferably an alkenyl group having 2 to 20 carbon atoms.

[0139] Preferably, the component (F) is one or more kinds of organic polysiloxane selected from (F1) an organic polysiloxane having no curable reactive group having a carbon-carbon double bond within the molecule and (F2) an organic polysiloxane having a curable reactive group having a carbon-carbon double bond within the molecule, and either the component (F1) alone, the component (F2) alone, or both can be used. Furthermore, in the case where the component (F2) is used in at least a part of the component (F), the present composition can be designed as curable.

[0140] Component (F1) is an organic polysiloxane having no curable reactive group containing a carbon-carbon double bond in the molecule, having no curable reactive group represented by the alkenyl group, the methacryloyloxy group-containing organic group, or the acryloyloxy group-containing organic group in the molecule, and is suitable as a main agent for a non-curable heat conductive organic polysiloxane composition such as a heat conductive silicone grease, a non-curable heat conductive caulking material, or the like. The functional group in component (F1) is a group other than the curable reactive functional group, and examples include alkyl groups such as methyl; aryl groups such as phenyl; halogenated alkyl groups such as 3,3,3-trifluoropropyl; and monovalent hydrocarbon groups other than the alkenyl group, with methyl or phenyl being preferred in industry.

[0141] Particularly preferably, component (F1) is a linear non-curable organic polysiloxane, and examples include dimethylpolysiloxane terminated at both molecular chain ends by trimethylsiloxy groups, dimethylsiloxane-methylphenylsiloxane copolymer terminated at both molecular chain ends by trimethylsiloxy groups, dimethylsiloxane copolymer terminated at both molecular chain ends by silanol groups, polymers in which a part of the methyl groups of these polymers are substituted by alkyl groups other than methyl such as ethyl, propyl, or halogenated alkyl groups such as 3,3,3-trifluoropropyl, and mixtures of two or more of these polymers.

[0142] Component (F2) is an organic polysiloxane having a curable reactive group containing a carbon-carbon double bond in the molecule, and is suitable as a main agent for a curable heat conductive organic polysiloxane composition such as a curable heat conductive elastomer, a heat conductive gel, a curable heat conductive caulking material, or the like, because the curable reactive group containing a carbon-carbon double bond in the molecule has at least one or more organic groups selected from the alkenyl group, the methacryloyloxy group-containing organic group, and the acryloyloxy group-containing organic group in the molecule.

[0143] As the alkenyl group in component (F2), examples include a vinyl group, an allyl group, a butenyl group, a hexenyl group, and the like. In addition, as the organic group other than the alkenyl group in component (F2), examples include alkyl groups such as methyl; aryl groups such as phenyl; halogenated alkyl groups such as 3,3,3-trifluoropropyl; and monovalent hydrocarbon groups other than the alkenyl group, with methyl or phenyl being preferred in industry.

[0144] It is particularly preferable that the component (F2) is a linear alkenyl group-containing organopolysiloxane, and examples thereof include: a dimethylvinylsiloxy-terminated dimethylpolysiloxane having both molecular chain terminals dimethylvinylsiloxy groups, a dimethylvinylsiloxy-terminated dimethylsiloxane / methylphenylsiloxane copolymer having both molecular chain terminals dimethylvinylsiloxy groups, a trimethylsiloxy-terminated dimethylsiloxane / methylvinylsiloxane copolymer having both molecular chain terminals trimethylsiloxy groups, a trimethylsiloxy-terminated dimethylsiloxane / methylvinylsiloxane / methylphenylsiloxane copolymer having both molecular chain terminals trimethylsiloxy groups, a silanol-terminated dimethylsiloxane / methylvinylsiloxane copolymer having both molecular chain terminals silanol groups, a polymer in which a part of the methyl groups of these polymers are substituted with an alkyl group other than methyl, a halogenated alkyl group such as 3,3,3-trifluoropropyl, a polymer in which a vinyl group of these polymers is substituted with an alkenyl group other than vinyl, such as allyl, butenyl, hexenyl, and a mixture of two or more of these polymers.

[0145] In the case where the component (F) contains the component (F2), it is preferable to contain, as a curing agent of the composition, (G) an organohydrogenpolysiloxane, and (H) a catalytic amount of a catalyst for a hydrosilylation reaction.

[0146] [(G) Organohydrogenpolysiloxane]

[0147] The component (G) is a main crosslinking agent of the composition of the present application, and an organohydrogenpolysiloxane having two or more silicon atom-bonded hydrogen atoms in the molecule can be used without particular limitation, but from the viewpoint of the softness and the adhesion retention to the substrate of the obtained cured product, the number of silicon atom-bonded hydrogen atoms in the molecule of the organohydrogenpolysiloxane is preferably in the range of not more than 8 (average value). It is particularly preferable to contain at least (G1) a linear organohydrogenpolysiloxane having a viscosity at 25°C of 1 m to 1000 mPa・s, containing an average of 2 to 4 silicon atom-bonded hydrogen atoms in the molecule, and having at least an average of 1 silicon atom-bonded hydrogen atom in the side chain of the molecular chain.

[0148] Such a component (G1) can be exemplified by: a trimethylsiloxy-terminated methylhydrogenosiloxane / dimethylsiloxane copolymer having both molecular chain terminals trimethylsiloxy groups, and a dimethylhydrogensiloxy-terminated methylhydrogenosiloxane / dimethylsiloxane copolymer having both molecular chain terminals dimethylhydrogensiloxy groups. Note that these examples are not limiting, and a part of the methyl groups can also be substituted with a phenyl group, a hydroxyl group, an alkoxy group, or the like.

[0149] The viscosity at 25°C of the component (G1) is not particularly limited, and is preferably in the range of 1 m to 500 mPa・s, particularly preferably in the range of 1 to 100 mPa・s, and from the viewpoint of preventing contact failure and the like, it is preferable to reduce or remove low-molecular-weight siloxane oligomers (octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5)).

[0150] [Amount of organohydrogenpolysiloxane (crosslinking agent) in the composition]

[0151] The composition of the present application is, with respect to component (G), at least 0.2 to 5.0 moles of silicon atom-bonded hydrogen atoms in component (G) per 1 mole of alkenyl group in component (F), particularly preferably in the range of 0.3 to 3.0 moles or 0.4 to 2.0 moles, from the viewpoint of the rubber properties, mechanical strength, and adhesive properties of the resulting organopolysiloxane cured product.

[0152] [ (H) Catalyst for hydrosilylation reaction]

[0153] The catalyst for hydrosilylation reaction is a component used for the curing of the present composition, and examples thereof include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, with platinum-based catalysts being preferred from the viewpoint of being able to significantly promote the curing of the present composition. As the platinum-based catalyst, examples include platinum fine powder, chloroplatinic acid, an alcohol solution of chloroplatinic acid, platinum-alkenylsiloxane complexes, platinum-olefin complexes, platinum-carbonyl complexes, and catalysts in which these platinum-based catalysts are dispersed or encapsulated in thermoplastic resins such as silicone resins, polycarbonate resins, and acrylic resins, with platinum-alkenylsiloxane complexes being particularly preferred. Particularly preferred is a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex of platinum, which is preferably added in the form of an alkenylsiloxane solution of the complex. In addition, from the viewpoint of improving the workability and pot life of the composition, a particulate platinum-containing catalyst for hydrosilylation reaction that has been dispersed or encapsulated in a thermoplastic resin can also be used. Note that, as a catalyst for promoting the hydrosilylation reaction, non-platinum-based metal catalysts such as iron, ruthenium, and iron / cobalt can also be used.

[0154] On the other hand, as the catalyst for hydrosilylation reaction, so-called high-energy ray-activating catalysts or light-activating catalysts such as (methylcyclopentadienyl)trimethylplatinum (IV) complex and bis(2,4-pentanedionate)platinum (II) complex can be used. By using such a catalyst for hydrosilylation reaction, as the entire composition, it is sometimes possible to achieve the following properties: triggered by irradiation with high-energy rays, the composition can be cured even at low temperatures, has excellent storage stability, and the control of the reaction is easy, so the workability is excellent. In this case, as the high-energy rays, from the viewpoint of the efficiency of the activation of the catalyst, ultraviolet rays are preferred, and from the viewpoint of industrial application, ultraviolet rays in the range of wavelengths of 280 to 380 nm are preferred. In addition, the amount of irradiation differs depending on the type of high-energy ray-activating catalyst, but in the case of ultraviolet rays, the cumulative amount of irradiation at a wavelength of 365 nm is preferably in the range of 100 mJ / cm 2 ~ 100 J / cm 2 .

[0155] The amount of the catalyst to be added to the hydrosilylation reaction is the catalytic amount, and more specifically, the amount of metal atoms is in the range of 0.01 to 500 ppm, in the range of 0.01 to 100 ppm, or in the range of 0.01 to 50 ppm, in terms of mass, relative to the entire composition.

[0156] [(J) fatty acid-based compound]

[0157] In the case where the composition of the present application is curable, in addition to the above-mentioned components, optionally, at least one or more fatty acid-based compounds selected from fatty acid esters and fatty acid metal salts can be contained. This component is a component that suppresses the change in hardness at the time of heat aging for the composition of the present application and the cured product of the composition of the present application, which is a heat conductive member of the silicone type. In particular, in the case where the blending amount of the above-mentioned heat conductive filler is in the above-mentioned range, in the case where component (J) is not used, the cured product is sharply hardened at the time of heat aging, and the stress relaxation, softness, and substrate adhesion, etc. can be impaired, but by using component (J) in combination with a heat resistance imparting agent, which is preferably component (K) described later, in the hydrosilylation-curable composition, the obtained cured product has a high thermal conductivity, and maintains the initial hardness and rubber properties, and good stress relaxation, softness, and substrate adhesion can be achieved.

[0158] Component (J) is specifically at least one or more selected from fatty acids, fatty acid esters, and fatty acid metal salts, and examples thereof include hexanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, and the like; fatty acid esters as alkyl esters thereof; alkali metal salts of fatty acids such as sodium, lithium, and potassium; and alkaline earth metal salts of fatty acids such as calcium. It is preferable that component (J) be (J1) at least one or more selected from saturated fatty acids and saturated fatty acid metal salts, and it is particularly preferable that (J1-1) be one or more selected from stearic acid, alkali metal salts of stearic acid, and alkaline earth metal salts of stearic acid.

[0159] The mechanism of action of component (J) to suppress the change in hardness of the cured product, particularly in a combined system with component (K), is not clearly determined, but it is presumed as follows: the fatty acid-based compounds such as fatty acids, fatty acid salts (soaps), fatty acid esters exist in a limited amount in the silicone cured product matrix having improved heat resistance in the presence of component (K), thereby forming a water-resistant and lubricious thin film or partial structure composed of these fatty acid-based compounds on the surface of the thermally conductive filler particles or in the vicinity thereof, chemically inactivating the particle surface at high temperatures, and effectively preventing the agglomeration between the surfaces of the thermally conductive filler, the formation of coarse particles. However, component (J) exerts a technical effect even if it is not used as a surface treatment agent for the thermally conductive filler, but is simply uniformly mixed with other components, and therefore in the present application, the timing of adding component (J) to the composition is not limited.

[0160] The blending amount of component (J) is preferably in the range of 0.05 to 2.0 parts by mass with respect to 100 parts by mass of the thermally conductive filler (total amount when composed of a plurality of components) containing components (A) to (D). In particular, in order to achieve the technical effect described above, the blending amount of component (D) needs to be in the range described above, which has a critical significance. That is, if the blending amount of component (J) is less than the lower limit described above, the change in hardness of the cured product cannot be suppressed even when combined with component (K). On the other hand, if the blending amount of component (J) exceeds the upper limit described above, the change in hardness of the cured product cannot be suppressed.

[0161] [K] Heat Resistance Imparting Agent

[0162] The composition of the present application can optionally contain a heat resistance imparting agent in addition to the above components. The heat resistance imparting agent can be blended alone, but the composition and the cured product thereof involved in the present application can achieve the technical effect thereof by containing a certain amount of the above (J) fatty acid-based compound, and by combining (K) heat resistance imparting agent. The blending amount of the heat resistance imparting agent can be in the range of 0.01 to 5.0% by mass, 0.05 to 2.0% by mass, 0.07 to 0.5% by mass, of the entire composition (solid content).

[0163] Examples of the heat resistance-imparting agent include metal oxides such as iron oxide, titanium oxide, cerium oxide, magnesium oxide, and zinc oxide; metal hydroxides such as cerium hydroxide; phthalocyanine compounds; cerium silicate alkoxide; cerium fatty acid salt; reaction products of organic polysiloxane and carboxylic acid salt of cerium; and carbon black. Among them, the phthalocyanine compound (K1) is particularly preferred. Examples of the phthalocyanine compound include those disclosed in Japanese Patent Application Publication No. 2014-503680, and among them, copper phthalocyanine compounds are particularly preferred. One example of the heat resistance-imparting agent is 29H, 31H-phthalocyanine (2-)-N29, N30, N31, N32 copper. Such a phthalocyanine compound is commercially available, for example, as Stan-tone (trademark) 40SP03 from PolyOne Corporation (Avon Lake, Ohio, USA). By formulating carbon black (K2) as the heat resistance-imparting agent in a range of 0.1 to 5% by mass, preferably 0.2 to 2% by mass, relative to the entire composition, the heat aging resistance at 180°C or higher and the high-temperature heat resistance can be improved.

[0164] [(L) Silane Hydrido Addition Reaction Inhibitor, Adhesion Promoter, Organic Solvent, and Other Additives]

[0165] The composition according to the present application contains components (A) to (F) as essential components, and in the case of containing a curable component (F2) as component (F), it is preferred to further contain components (G) and (H), and it is more preferred to contain one or more selected from components (J) and (K), and it is particularly preferred to use both components (J) and (K), but it can also contain other components described below. In particular, in the case of the composition having curability, it is particularly preferred to use a silane hydrido addition reaction inhibitor.

[0166] [(L) Silane Hydrido Addition Reaction Inhibitor, Adhesion Promoter, Organic Solvent, and Other Additives]

[0167] In the case where the composition of the present application has curability, it is preferable to further include a hydrosilylation reaction inhibitor from the viewpoint of its handling workability. The hydrosilylation reaction inhibitor is a component for inhibiting the hydrosilylation reaction of the heat conductive organopolysiloxane composition of the present application, and specifically, for example, acetylene-based, amine-based, carboxylate-based, phosphite-based, and the like can be cited as the reaction inhibitor. The addition amount of the reaction inhibitor is usually 0.001 to 5 mass% of the entire heat conductive organopolysiloxane composition. In particular, for the purpose of improving the handling workability of the present composition, acetylene-based compounds such as 3-methyl-1-butyne-3-ol, 3,5-dimethyl-1-hexyne-3-ol, 3-phenyl-1-butyne-3-ol (= phenylbutynol), and the like; ene-yne compounds such as 3-methyl-3-penten-1-yne, 3,5-dimethyl-3-hexen-1-yne, and the like; cycloalkenyl siloxanes such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane, and the like; methyl tri-1,1-dimethyl-2-propynoxy silane; triazole compounds such as benzotriazole, and the like can be used without particular limitation.

[0168] [adhesion-imparting agent]

[0169] In the composition of the present application, an adhesion-imparting agent can also be formulated for the purpose of improving the adhesion strength of a cured product thereof and the permanent adhesion to a substrate. The adhesion-imparting agent that can be used in the present application can be selected from one or more of the following adhesion-imparting agents: a reaction mixture of an amino group-containing organoalkoxysilane and an epoxy group-containing organoalkoxysilane (including a carbasilatrane derivative having a specific structure, a hetero-nitrogen silatrane derivative) as a conventionally known adhesion-imparting agent, an organic compound having two or more alkoxysilane groups in the molecule, represented by a disilaalkane compound (for example, 1,6-bis(trimethoxysilyl)hexane), an epoxy group-containing silane, or a partial hydrolytic condensate thereof, and two or more adhesion-imparting agents selected from among them can be used in combination and are preferable.

[0170] It is preferable that the adhesion-imparting agent include (L-1) and (L-2) in a mass ratio of 5:95 to 95:5, preferably in a mass ratio of 50:50 to 95:5, and more preferably in a mass ratio of 60:40 to 90:30.

[0171] (L-1) is represented by the general formula:

[0172] R a n Si(OR b ) 4-n

[0173] (In the formula, R a is a monovalent organic group containing an epoxy group, R b is an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. n is a number in the range of 1 to 3)

[0174] an epoxy group-containing silane represented by the formula shown below or a partial hydrolytic condensate thereof; and

[0175] (L-2) an organic compound having at least two alkoxysilane groups in one molecule and containing a bond other than a silicon-oxygen bond between the silane groups. Note that these components, although they can improve the initial adhesion of the organopolysiloxane cured product even alone, when used in combination in the above-mentioned mass ratio, can sometimes greatly improve the initial adhesion, adhesion durability, and adhesion strength (permanent adhesion) of the organopolysiloxane cured product.

[0176] As the component (L-1) described above, for example, 3-glycidylpropyloxyprolinoyltrimethoxysilane, 3- glycidoxypropylmethyldimethoxysilane, 2-(3,4- epoxycyclohexyl)ethyltrimethoxysilane, and 2-(3,4- epoxycyclohexyl)ethylmethyldimethoxysilane can be given.

[0177] As the component (L-2) described above, for example, 1,6- bis(trimethoxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,4- bis(trimethoxysilyl)hexane, 1,5-bis(trimethoxysilyl)hexane, 2,5- bis(trimethoxysilyl)hexane, 1-methyldimethoxysilyl-6- trimethoxysilylhexane, 1-phenyldiethoxysilyl-6- triethoxysilylhexane, and the like disilazalkanes can be given.

[0178] As the adhesion-imparting agent other than the components (L-1) and (L-2) described above, a reaction mixture of an amino group-containing organic alkoxysilane and an epoxy group-containing organic alkoxysilane (containing a cyclic carbonitrosiloxane derivative having a specific structure, a heteronitrogen silatrane derivative) disclosed in Japanese Patent Publication No. 52-8854 and Japanese Patent Laid-Open No. 10-195085 can also be further used in combination.

[0179] [Other additives for organic solvents]

[0180] The thermally conductive composition of the present application can be formulated with any component other than the above components, within a range not impairing the object of the present application. As the any component, for example, cold resistance-imparting agents, flame retardancy-imparting agents, pigments, dyes, and the like can be given. In addition, the thermally conductive composition of the present application can contain, as necessary, one or more antistatic agents composed of known surfactants and the like; dielectric fillers; electrically conductive fillers; mold release components; thixotropy-imparting agents; mildewproofing agents; and the like. Furthermore, an organic solvent can also be added as necessary.

[0181] [Manufacturing method of the composition and dosage form]

[0182] The thermally conductive composition of the present application can be manufactured by mixing the above components, and as the mixing device, the same devices as exemplified in the surface treatment of the filler can be exemplified. Furthermore, as described above, the component (J) can be added at the timing after the surface treatment of the filler / basic heating, or can be added together with the surface treatment agent of the filler, and the technical effects of the present application can be achieved regardless of the timing of addition.

[0183] More specifically, the composition of the present application is preferably manufactured by any one of:

[0184] i) a manufacturing method having a step of mixing the above components (F), filler, and component (E), and then optionally mixing component (J) and other components;

[0185] ii) a manufacturing method having a step of mixing the above components (F), filler, optional component (J), and component (E), and then mixing other components

[0186] The mixing process). Note that the heating conditions are the same as the basic heating conditions described earlier in the surface treatment of the filler, and the mixing is preferably performed in a manner that the entire mixture is substantially uniformly mixed.

[0187] The heat conductive composition according to the present application can be a one-component type composition, a composition optionally containing the above-mentioned hydrosilylation reaction inhibitor and other components, or a multi-component type composition composed of two or more compositions stored separately. In the case of the multi-component type composition, it is necessary to contain the above-mentioned component (F) containing component (F2), component (G) and component (H) separately. This is because, if these components (main agent, crosslinking agent and catalyst) are mixed together, the crosslinking reaction starts automatically, and the storage stability of the composition is lost in a short time, and sometimes the long-term storage stability and the handling workability as a multi-component type composition cannot be achieved. Note that the multi-component type composition is mixed by stirring with a mechanical force such as a stirrer in a common container, or mixed by a dispenser or the like corresponding to the mixing of the multi-components at the time of use.

[0188] The heat conductive composition according to the present application has an extremely high thermal conductivity, and the cured product thereof has excellent softness and stress relaxation properties, and is easily extruded from a syringe or a dispenser, and has excellent work efficiency, filling properties and coating properties, and thus even in the case of being used in filling into a syringe or the like of a small scale, particularly a small amount, for example, 10 to 300 ml or so, it has the advantage that the coating and extrusion workability to a heat dissipation site is excellent. Therefore, the present composition has the advantage that it is easily filled into a syringe or the like of a small scale, and is also easily applied to small-capacity packaging production. In particular, by the heat conductive composition according to the present application containing component (E1) as component (E), and using an organopolysiloxane in which a is a number in the range of 40 to 90 and b is 3 in the above-mentioned general formula (1), the extrusion workability thereof can sometimes be further improved, and it is particularly suitable for small-capacity packaging production.

[0189] [Use of non-cured / non-cured composition]

[0190] The heat conductive composition according to the present application can be applied to a heat dissipation member or a circuit board on which the heat dissipation member is mounted, in a non-cured or uncured state, to obtain a heat dissipation structure provided with an uncured heat dissipation member (exemplified by a heat dissipation silicone grease or an uncured heat conductive gap filler).

[0191] [Curing property]

[0192] The thermally conductive composition according to the present application is cured by a hydrosilylation reaction in a case where at least a part of component (F) contains a curable component (F2), and can form a cured product that is excellent in thermal conductivity, and in which a change in hardness after heat aging is suppressed, and that is excellent in flexibility and stress relaxation properties. The temperature conditions for curing the hydrosilylation reaction-curable composition are not particularly limited, and are generally in the range of 20°C to 200°C, preferably in the range of 20°C to 150°C, and more preferably in the range of 20°C to 80°C. It can be cured at a high temperature for a short time as desired, or can be cured at a low temperature such as room temperature for a long time (for example, several hours to several days), and is not particularly limited. Note that, by selecting a high-energy ray-activating catalyst or a light-activating catalyst for at least a part of component (H), curing triggered by irradiation with a high-energy ray can be performed.

[0193] By using the thermally conductive composition according to the present application, a cured product can be formed in the range of 20°C to 150°C, preferably less than 130°C, for example, 20 to 125°C, by applying the above-mentioned curable thermally conductive composition to a heat dissipation member or a circuit board on which the heat dissipation member is mounted, and a heat dissipation structure provided with the heat dissipation member.

[0194] [Thermal conductivity]

[0195] The thermally conductive composition according to the present application can be stably highly filled with a thermally conductive filler, and preferably has a thermal conductivity of 9.0 W / mK or more, and particularly preferably 9.1 W / mK or more. Furthermore, in the thermally conductive composition according to the present application, a composition and a cured product in which the thermal conductivity is designed to be 9.0 to 15.0 W / mK, and the thermal conductivity is 9.1 to 14.0 W / mK as needed, are excellent in workability such as extrudability and dispensability from a syringe or the like. Furthermore, the composition can be curable or non-curable, and in the case of being curable, by using component (J) / (K) (particularly, by using at least one of a phthalocyanine compound as component (K1) and carbon black as component (K2)), a change in hardness after heat aging is suppressed, and a thermally conductive cured product that is excellent in flexibility and stress relaxation properties can be achieved. Similarly, by using an organopolysiloxane containing component (E1) as component (E), and in which a in the above general formula (1) is a number in the range of 40 to 90, and b is 3, in addition to improvement in extrusion workability and thermal conductivity, heat aging properties, particularly at a high temperature, can sometimes be improved favorably.

[0196] [Use and heat dissipation structure]

[0197] The heat conductive composition and the cured product thereof of the present application are useful as a heat transfer material (heat conductive member) between the thermal boundary surface of a heat generating component and the interface of a heat sink or a circuit substrate or the like, and a heat dissipation structure body provided with the same can be formed. Here, the kind, size, and detailed structure of the heat generating component are not particularly limited, but the heat conductive composition or the cured product thereof of the present application, which has high thermal conductivity while having excellent initial adhesion and adhesion strength to the member, can maintain softness and stress relaxation properties even after heat aging, and thus is less likely to peel off or generate a gap from the heat generating member due to vibration or the like, has high adhesiveness and followability, and is excellent in industrial productivity, and thus is suitable for application to a heat dissipation structure body of an electrical / electronic device including an automobile component, an electrical / electronic component, or a secondary battery of a battery cell type.

[0198] The structure of such a heat dissipation structure body is not particularly limited, and a heat dissipation structure body in which a heat dissipation member is mounted on a heat dissipation member or a circuit substrate on which the heat dissipation member is mounted via the heat conductive composition or the cured product thereof can be exemplified. Such a structure is exemplified by, for example, a structure in which an electronic component as a heat dissipation component is mounted on a circuit substrate, and heat generated from the electronic component is dissipated through a thin film layer of the heat conductive composition or the cured product thereof by a heat dissipation member, and these members have small changes in hardness after heat aging as a feature of the present application, maintain softness and stress relaxation properties of the heat dissipation member, and have excellent adhesiveness and followability, and thus can be disposed not only on a horizontal plane but also on an inclined plane or a vertical plane.

[0199] In such a heat dissipation structure body, the thickness of the heat conductive composition or the cured product thereof is not particularly limited, and can be in the range of 0.1 to 100 mm, and heat generated from an electronic component filled with the composition or the cured product thereof without a gap can be efficiently transferred to a heat dissipation member.

[0200] The electrical / electronic device provided with the member formed of the above-described thermally conductive composition is not particularly limited, and examples thereof include, for example, a secondary battery such as an electric chip-type lithium ion electrode secondary battery, a battery stack-type fuel cell, and the like; an electronic circuit substrate such as a printed substrate; an IC chip in which a diode (LED), an organic electroluminescent element (organic EL), a laser diode, a light semiconductor element such as an LED array are packaged; a CPU used in an electronic device such as a personal computer, a digital video disc, a portable telephone, a smartphone, and the like; a driver IC, a memory, and the like LSI chip. In particular, in a high-performance digital / switching circuit formed at a high integration density, heat removal (heat dissipation) becomes a major factor for the performance and reliability of the integrated circuit, and the thermally conductive member formed using the thermally conductive organopolysiloxane composition of the present application is excellent in heat dissipation and workability even in the case of application to a power semiconductor use such as engine control, power-train, air-conditioning control, and the like in a conveyer, and can maintain firm adhesion to the member even in the case of use in a severe environment of an embedded electronic control unit (ECU) and the like vehicle-mounted electronic component, and realizes excellent heat resistance and thermal conductivity.

[0201] Examples

[0202] Hereinafter, the present application will be described with examples, but the present application is not limited to these examples. In the examples and comparative examples shown below, the following compounds or compositions were used as raw materials. In addition, the average particle diameter of the thermally conductive filler was the cumulative average particle diameter D50 (median diameter) in the particle size distribution based on volume measured by a laser diffraction scattering method, which was determined by the coarse particle content (volume %) measured by this method.

[0203] [Preparation of the composition and production of the thermally conductive organosilicon cured product (evaluation sample)]

[0204] The thermally conductive compositions of Examples 1 to 12 and Comparative Examples 1 to 6 (hereinafter sometimes referred to as "thermally conductive organosilicon compositions") were obtained by mixing the components by the method described later. In addition, in the case where the composition had curability, the thermally conductive organosilicon composition was filled into a mold having a height of 6 mm, a length of 50 mm, and a width of 30 mm, and cured at 80°C for 30 minutes, and then taken out of the mold, to obtain a thermally conductive organosilicon cured product. The hardness of the obtained thermally conductive organosilicon cured product was measured by the following method.

[0205] [Hardness (E-type hardness)]

[0206] The measurement of the hardness was performed by overlapping two pieces of the thermally conductive organosilicon cured product obtained under the above-described conditions, and measuring the value after 3 seconds using an ASKER TYPE E hardness tester manufactured by ASKER Co.

[0207] [Thermal and electric conductivities]

[0208] The thermal conductivity was measured using a Dyn TIM tester (manufactured by Siemens). The thermal resistance was measured at a thickness of 800 μm, 600 μm, 400 μm, and 200 μm of the thermal conductivity composition, and the thermal conductivity was calculated from the slope thereof.

[0209] [Extrusion amount]

[0210] The extrusion amount was measured by filling the thermal conductivity composition into a 30 cc EFD syringe (manufactured by Nordson) and measuring the extrusion weight per 1 minute when extruded at an extrusion pressure of 80 psi.

[0211] The composition of the present application was formed from the following components. In addition, in the thermal conductivity filler used in the examples, the particle mixing amount of the amorphous aluminum nitride powder having an average particle diameter of less than 2.0 μm was 0 vol%.

[0212] Component (A):

[0213] A-1: Amorphous zinc oxide powder having an average particle diameter of 0.12 μm

[0214] A-2: Polyhedral α-alumina powder having an average particle diameter of 0.5 μm

[0215] A-3: Polyhedral α-alumina powder having an average particle diameter of 0.24 μm

[0216] Component (B):

[0217] B-1: Polyhedral α-alumina powder having an average particle diameter of 2 μm

[0218] B-2: Amorphous aluminum nitride powder having an average particle diameter of 19 μm, and a particle mixing amount of 0 vol% of particles having a particle diameter of 2.5 μm or less

[0219] B-3: Amorphous aluminum nitride powder having an average particle diameter of 28 μm, and a particle mixing amount of 0 vol% of particles having a particle diameter of 6 μm or less

[0220] Non-B-1: Amorphous aluminum nitride powder having an average particle diameter of 2 μm (particle mixing amount of 45.3 vol% of particles having a particle diameter of less than 2 μm)

[0221] Non-B-2: Amorphous aluminum nitride powder having an average particle diameter of 1.2 μm

[0222] Component (C):

[0223] C-1: Amorphous aluminum nitride powder having an average particle diameter of 30 μm, and a particle mixing amount of 0 vol% of particles having a particle diameter of 3 μm or less

[0224] C-2: Amorphous aluminum nitride powder having an average particle diameter of 100 μm, and a particle mixing amount of 0 vol% of particles having a particle diameter of 26 μm or less

[0225] C-3: Amorphous aluminum nitride powder having an average particle diameter of 157 μm and 0 vol% of particles having a particle diameter of 52 μm or less

[0226] Component (D):

[0227] D-1: Spherical aluminum nitride powder having an average particle diameter of 80 μm

[0228] Component (X):

[0229] X-1: Spherical magnesium oxide powder having an average particle diameter of 120 μm

[0230] X-2: Spherical fused and solidified alumina powder having an average particle diameter of 90 μm

[0231] Component (E):

[0232] E-1: Organopolysiloxane represented by the formula: (CH3)3SiO[(CH3)2SiO] 30 Si(OCH3)3

[0233] E-2: Organopolysiloxane represented by the formula: (C2H5)(CH3)2SiO[(CH3)2SiO] 27 Si(OCH3)3

[0234] E-3: Decyltrimethoxysilane

[0235] E-4: Organopolysiloxane represented by the formula: (CH3)3SiO[(CH3)2SiO] 60 Si(OCH3)3

[0236] Component (F):

[0237] F-1: Dimethylpolysiloxane terminated at both molecular chain terminals with trimethylsiloxy groups (viscosity 20 mPa-s)

[0238] F-2: Dimethylpolysiloxane terminated at both molecular chain terminals with dimethylvinylsiloxy groups (viscosity 60 mPa-s, Vi content 1.53 mass%)

[0239] F-3: Dimethylpolysiloxane terminated at both molecular chain terminals with dimethylvinylsiloxy groups (viscosity 28 mPa-s, Vi content 2.3 mass%)

[0240] Component (G):

[0241] G-1: Methylhydrogensiloxane-dimethylsiloxane copolymer terminated at both molecular chain terminals with trimethylsiloxy groups, having an average of 2 within the molecule and an average of 2 as a side chain of the molecular chain (viscosity 20 mPa-s, Si-H content 0.10 mass%)

[0242] G-2: Methylhydrogen siloxane-dimethyl siloxane copolymer capped with trimethylsiloxy groups at both terminals, 5 on average in the molecule and 5 on average in the side chain of the molecule (viscosity 5 mPa-s, Si-H content 0.77 mass%)

[0243] G-3: Methylhydrogen siloxane-dimethyl siloxane copolymer capped with trimethylsiloxy groups at both terminals, 3 on average in the molecule and 3 on average in the side chain of the molecule (viscosity 12 mPa-s, Si-H content 0.21 mass%)

[0244] G-4: 1,1,1,3,5,5,5-heptamethyltrisiloxane (Si-H content 0.45 mass%)

[0245] Ingredient (H):

[0246] H-1: Complex of platinum and 1,3-divinyl-1,1,3,3-tetramethyldisiloxane at a platinum concentration of 0.6% by weight

[0247] Ingredient (Y):

[0248] Y-1: Phenylbutynol

[0249] Y-2: Methyltris-1,1-dimethyl-2-propynoxy silane

[0250] Ingredient (K):

[0251] K-1: 29H,31H-phthalocyanine (2-)-N29,N30,N31,N32 copper

[0252] Other ingredients:

[0253] Ingredient (J-1): Calcium stearate (Fuji Photo Film and Mitsui & Co., Ltd.)

[0254] (K-2-1) Carbon black-1: Manufactured by cancarb Co., Ltd., product code THERMAX FLOFORM N-990 (particle diameter 280 nm, specific surface area 9 m 2 / g)

[0255] (K-2-2) Carbon black-2: Manufactured by Denka Co., Ltd., product code Denka Black (particle diameter 36 nm, specific surface area 58 m 2 / g)

[0256] (K-2-3) Carbon black-3: Manufactured by Asahi Carbon Co., Ltd., product code SUNBLACK 235 (particle diameter 78 nm, specific surface area 21 m 2 / g)

[0257] [Example 1]

[0258] In a 300-ml plastic container, 16.5 parts by mass of component (A-1), 29.5 parts by mass of component (B-1), 18.0 parts by mass of component (C-1), 1.50 parts by mass of component (E-1), 0.20 parts by mass of component (E-3), and 2.73 parts by mass of component (F-1) were weighed, and mixed at 2000 rpm for 1 minute using a THINKY Planetary Vacuum Mixer. Next, 10.8 parts by mass of component (D-1) and 20.77 parts by mass of component (X-1) were added, and mixed at 2000 rpm for 1 minute. After scraping off the components adhered to the wall of the plastic container with a spatula, the mixture was stirred at 2000 rpm for 1 minute. After cooling to room temperature, vacuum degassing was performed for 3 minutes, thereby preparing a heat-conducting silicone composition.

[0259] [Example 2]

[0260] In a 300-ml plastic container, 24.0 parts by mass of component (A-1), 28.6 parts by mass of component (B-1), 18.0 parts by mass of component (C-1), 1.50 parts by mass of component (E-1), 0.20 parts by mass of component (E-3), and 2.60 parts by mass of component (F-1) were weighed, and mixed at 2000 rpm for 1 minute using a THINKY Planetary Vacuum Mixer. Next, 10.0 parts by mass of component (D-1) and 15.1 parts by mass of component (X-1) were added, and mixed at 2000 rpm for 1 minute. Thereafter, a heat-conducting silicone composition was prepared in the same manner as in Example 1.

[0261] [Example 3]

[0262] In a 300-ml plastic container, 16.8 parts by mass of component (A-1), 18.0 parts by mass of component (B-1), 18.0 parts by mass of component (C-1), 1.50 parts by mass of component (E-1), 0.20 parts by mass of component (E-3), and 2.81 parts by mass of component (F-1) were weighed, and mixed at 2000 rpm for 1 minute using a THINKY Planetary Vacuum Mixer. Next, 11.4 parts by mass of component (D-1) and 31.29 parts by mass of component (X-1) were added, and mixed at 2000 rpm for 1 minute. Thereafter, a heat-conducting silicone composition was prepared in the same manner as in Example 1.

[0263] [Example 4]

[0264] In a 300-ml plastic container, 24.18 parts by mass of component (A-1), 23.0 parts by mass of component (B-1), 18.0 parts by mass of component (C-1), 1.50 parts by mass of component (E-1), 0.20 parts by mass of component (E-3), and 2.62 parts by mass of component (F-1) were weighed, and mixed at 2000 rpm for 1 minute using a THINKY Planetary Vacuum Mixer. Next, 4.50 parts by mass of component (D-1) and 26.0 parts by mass of component (X-1) were added, and mixed at 2000 rpm for 1 minute. Thereafter, a thermally conductive silicone composition was produced in the same manner as in Example 1.

[0265] [Comparative Example 1]

[0266] In a 300-ml plastic container, 17.45 parts by mass of component (A-1), 25.5 parts by mass of component (Non-B-1), 18.0 parts by mass of component (C-1), 1.59 parts by mass of component (E-1), 0.21 parts by mass of component (E-3), and 2.90 parts by mass of component (F-1) were weighed, and mixed at 2000 rpm for 1 minute using a THINKY Planetary Vacuum Mixer. Next, 12.6 parts by mass of component (D-1) and 21.8 parts by mass of component (X-1) were added, and mixed at 2000 rpm for 1 minute. Thereafter, a thermally conductive silicone composition was produced in the same manner as in Example 1.

[0267] [Comparative Example 2]

[0268] A thermally conductive silicone composition was produced in the same manner as in Comparative Example 1, except that 25.5 parts by mass of component (Non-B-1) in Comparative Example 1 was replaced with 25.5 parts by mass of component (Non-B-2).

[0269] With respect to the thermally conductive silicone compositions of Examples 1 to 4 and Comparative Examples 1 to 2, the compositions, thermal conductivities of the obtained thermally conductive silicone compositions, and extrusion amounts are shown in Table 1.

[0270]

[0271] [Example 5]

[0272] In a 300-ml plastic container, the ingredients (A-2) 14.5 parts by mass, ingredient (B-1) 20.0 parts by mass, ingredient (C-1) 18.0 parts by mass, ingredient (E-1) 1.50 parts by mass, ingredient (E-3) 0.20 parts by mass, ingredient (F-2) 4.0 parts by mass were weighed, and mixed at 2000 rpm for 1 minute using a THINKY Planetary Vacuum Mixer. Next, ingredient (D-1) 7.0 parts by mass, ingredient (X-1) 34.8 parts by mass were added, and mixed at 2000 rpm for 1 minute. After the ingredients adhered to the wall of the plastic container were scraped off with a spatula, mixing was performed at 2000 rpm for 1 minute. After cooling to room temperature, 3 minutes of vacuum degassing was performed, and a thermally conductive silicone composition was prepared.

[0273] [Example 6]

[0274] A thermally conductive silicone composition was prepared in the same manner as in Example 5, except that in Example 5, ingredient (C-1) 18.0 parts by mass was replaced with 5.0 parts by mass, ingredient (D-1) 7.0 parts by mass was replaced with 30.0 parts by mass, and ingredient (X-1) 34.8 parts by mass was replaced with 24.8 parts by mass.

[0275] [Comparative Example 3]

[0276] A thermally conductive silicone composition was prepared in the same manner as in Example 5, except that in Example 5, ingredient (C-1) 18.0 parts by mass was replaced with 3.0 parts by mass, ingredient (D-1) 7.0 parts by mass was replaced with 32.0 parts by mass, and ingredient (X-1) 34.8 parts by mass was replaced with 24.8 parts by mass.

[0277] [Comparative Example 4]

[0278] A thermally conductive silicone composition was prepared in the same manner as in Example 5, except that in Example 5, ingredient (C-1) 18.0 parts by mass and ingredient (D-1) 7.0 parts by mass were replaced with ingredient (D-1) 25.0 parts by mass.

[0279] [Comparative Example 5]

[0280] A thermally conductive silicone composition was prepared in the same manner as in Example 5, except that in Example 5, ingredient (C-1) 18.0 parts by mass was replaced with ingredient (B-3) 18.0 parts by mass.

[0281] With respect to the thermally conductive silicone compositions of Examples 5 to 6 and Comparative Examples 3 to 5, the composition, the thermal conductivity of the obtained thermally conductive silicone composition, and the extrusion amount are shown in Table 2.

[0282]

[0283] [Example 7]

[0284] In a 1000 ml-plastic container, ingredients (A-2) 14.3 parts by mass, ingredient (B-1) 20.0 parts by mass, ingredient (E-1) 1.20 parts by mass, ingredient (E-3) 0.20 parts by mass, ingredient (F-2) 3.10 parts by mass, ingredient (G-1) 0.850 parts by mass, ingredient (K-1) 0.15 parts by mass were weighed, and mixed at a rotation speed of 1500 rpm for 2 minutes using a KURABO MAZERUSTAR. Next, ingredient (B-2) 7.0 parts by mass, ingredient (C-1) 18.0 parts by mass, ingredient (X-2) 35.0 parts by mass, (J-1) calcium stearate 0.10 parts by mass were put, and mixed at a rotation speed of 1500 rpm for 2 minutes. After moving to a T.K. HIVIS MIX (Model) manufactured by TOKUSHU KIKA KOGYO CO., LTD., the mixture was heated under reduced pressure at 160°C for 60 minutes, and cooled to room temperature to obtain a mixture.

[0285] In the mixture, ingredient (G-2) 0.020 parts by mass, ingredient (Y-1) 0.0015 parts by mass were uniformly mixed. After that, ingredient (H-1) 0.075 parts by mass was uniformly mixed, and a thermally conductive silicone composition was prepared.

[0286] [Comparative Example 6]

[0287] A thermally conductive silicone composition was prepared similarly to Example 7 except that in Example 7, ingredient (B-1) 20.0 parts by mass and ingredient (C-1) 18.0 parts by mass were replaced with ingredient (C-1) 25.0 parts by mass.

[0288] Regarding the thermally conductive silicone compositions of Example 7 and Comparative Example 6, the composition, the hardness of the obtained thermally conductive silicone composition, the thermal conductivity, and the extrusion amount are shown in Table 3.

[0289]

[0290] [Example 8]

[0291] In a 1000 ml-plastic container, the ingredients (A-1) 16.5 parts by mass, ingredient (B-1) 29.5 parts by mass, ingredient (E-1) 1.50 parts by mass, ingredient (E-3) 0.20 parts by mass, ingredient (F-3) 1.68 parts by mass, ingredient (G-1) 0.60 parts by mass, ingredient (K-1) 0.13 parts by mass were weighed, and mixed at a rotation speed of 1500 rpm for 2 minutes using a KURABO MAZERU STAR. Next, ingredient (B-3) 18.0 parts by mass, ingredient (C-2) 10.8 parts by mass, ingredient (X-1) 20.7 parts by mass, (J-1) calcium stearate 0.10 parts by mass were put in, and mixed at a rotation speed of 1500 rpm for 2 minutes. After moving to a T.K. HIVIS MIX (type) manufactured by TOKUSHU KIKA KOGYO CO., LTD., the mixture was heated under reduced pressure at 160°C for 60 minutes, and cooled to room temperature to obtain a mixture.

[0292] In the mixture, ingredient (G-3) 0.10 parts by mass, ingredient (G-4) 0.149 parts by mass, ingredient (Y-1) 0.0015 parts by mass were uniformly mixed. After that, ingredient (H-1) 0.050 parts by mass was uniformly mixed, and a thermally conductive silicone composition was prepared.

[0293] [Example 9]

[0294] A thermally conductive silicone composition was prepared in the same manner as in Example 8 except that ingredient (B-3) 18.0 parts by mass was replaced with ingredient (C-1) 18.0 parts by mass, and ingredient (C-2) 10.8 parts by mass was replaced with ingredient (D-1) 10.8 parts by mass in Example 8.

[0295] [Example 10]

[0296] In a 1000-ml plastic container, 16.5 parts by mass of component (A-1), 24.0 parts by mass of component (B-1), 5.5 parts by mass of component (B-2), 1.45 parts by mass of component (E-1), 0.050 parts by mass of component (E-2), 0.20 parts by mass of component (E-3), 1.78 parts by mass of component (F-3), 0.66 parts by mass of component (G-1), 0.14 parts by mass of component (K-1) were weighed, and mixed at 1500 rpm for 2 minutes using a KURA BO MAZERU STAR. Next, 18.0 parts by mass of component (C-1), 20.8 parts by mass of component (D-1), 10.8 parts by mass of component (X-1), 0.10 parts by mass of (J-1) calcium stearate were added, and mixed at 1500 rpm for 2 minutes. After being transferred to a T.K. HIVIS MIX (Model) manufactured by TOKUSHU KIKA KOGYO CO., LTD., the mixture was heated under reduced pressure at 160°C for 60 minutes, and cooled to room temperature to obtain a mixture. In the mixture, 0.025 parts by mass of component (G-2), 0.0015 parts by mass of component (Y-1) were uniformly mixed. Thereafter, 0.050 parts by mass of component (H-1) were uniformly mixed, and a thermally conductive silicone composition was prepared.

[0297] [Example 11]

[0298] In a 1000-ml plastic container, 16.5 parts by mass of component (A-1), 24.0 parts by mass of component (B-1), 5.5 parts by mass of component (B-2), 1.45 parts by mass of component (E-1), 0.050 parts by mass of component (E-2), 0.20 parts by mass of component (E-3), 1.78 parts by mass of component (F-3), 0.66 parts by mass of component (G-1), 0.14 parts by mass of component (K-1) were weighed, and mixed at 1500 rpm for 2 minutes using a KURA BO MAZERU STAR. Next, 18.0 parts by mass of component (C-1), 20.8 parts by mass of component (D-1), 10.8 parts by mass of component (X-1), 0.10 parts by mass of (J-1) calcium stearate were added, and mixed at 1500 rpm for 2 minutes. After being transferred to a T.K. HIVIS MIX (Model) manufactured by TOKUSHU KIKA KOGYO CO., LTD., the mixture was heated under reduced pressure at 160°C for 60 minutes, and cooled to room temperature to obtain a mixture.

[0299] In the mixture, 0.025 parts by mass of component (G-2), 0.0015 parts by mass of component (J-1) were uniformly mixed. Thereafter, 0.060 parts by mass of component (H-1) were uniformly mixed, and a thermally conductive silicone composition was prepared.

[0300] [Comparative Example 7]

[0301] A heat conductive silicone composition was produced in the same manner as in Example 8, except that 18.0 parts by mass of the ingredient (C-1) was replaced with 21.0 parts by mass in Example 11.

[0302] As to the heat conductive silicone compositions of Examples 8 to 11 and Comparative Example 7, the compositions, the hardness of the obtained heat conductive silicone compositions, the thermal conductivity, and the extrusion amount are shown in Table 4.

[0303]

[0304] [Example 12]

[0305] In a 300-ml plastic container, 12.5 parts by mass of the ingredient (A-3), 25.2 parts by mass of the ingredient (B-1), 22.8 parts by mass of the ingredient (B-2), 20.25 parts by mass of the ingredient (C-3), 15.4 parts by mass of the ingredient (D-1), 0.20 parts by mass of the ingredient (E-3), 1.00 part by mass of the ingredient (E-4), 1.81 parts by mass of the ingredient (F-3), 0.55 parts by mass of the ingredient (G-1), 0.125 parts by mass of the ingredient (G-3), and 0.05 parts by mass of the ingredient (J-1) : calcium stearate were weighed, and mixed at a rotation speed of 2000 rpm for 2 minutes using a THINKY Planetary Vacuum Mixer. Next, 0.064 parts by mass of the ingredient (K-1) and 0.001 parts by mass of the ingredient (Y-2) were put in, and mixed at a rotation speed of 2000 rpm for 1 minute. After the ingredients adhered to the wall of the plastic container were scraped off with a spatula, the mixture was mixed at a rotation speed of 2000 rpm for 1 minute, and then cooled to room temperature. In the mixture, 0.05 parts by mass of the ingredient (H-1) was uniformly mixed, and a heat conductive silicone composition was produced.

[0306] [Example 13]

[0307] A-1) 14.28 parts by mass, component (B-1) 28.0 parts by mass, component (E-3) 0.20 parts by mass, component (E-4) 1.00 part by mass, component (F-3) 2.30 parts by mass, component (G-1) 0.795 parts by mass, component (G-3) 0.125 parts by mass, component (J-1): calcium stearate 0.10 parts by mass were weighed into a T.K. HIVIS MIX (type) manufactured by TOKUSHU KIKA KOGYO CO., LTD., and mixed at a rotation speed of 12 rpm for 10 minutes. Next, component (B-2) 19.0 parts by mass, component (C-2) 18.5 parts by mass, component (X-1) 15.5 parts by mass were weighed, and mixed at a rotation speed of 12 rpm for 10 minutes. Thereafter, the mixture was heated at 160°C under reduced pressure for 60 minutes, and cooled to room temperature to obtain a mixture. In the mixture, component (K-1) 0.149 parts by mass, component (Y-2) 0.001 parts by mass were uniformly mixed, and a thermally conductive silicone composition was prepared. Thereafter, component (H-1) 0.050 parts by mass was uniformly mixed, and a thermally conductive silicone composition was prepared.

[0308] [Examples 13C1, 13C2, 13C3]

[0309] In the thermally conductive silicone composition of Example 13, the above-mentioned carbon black-1, carbon black-2, carbon black-3 (K-2-1 to K-2-3) were formulated in the amounts shown in Table 5, respectively, and Example 13C1, Example 13C2, Example 13C3 were prepared.

[0310] With respect to the thermally conductive silicone compositions of Examples 12 and 13, 13C1 to 13C3, the composition, the hardness of the obtained thermally conductive silicone composition, the thermal conductivity, the extrusion amount, the heat resistance at 180°C are shown in Table 5. Further, in Examples 13 and 13C1 to 13C3 in the table, the common values are indicated with “←”.

[0311] [Heat resistance at 180°C evaluation]

[0312] In order to confirm the solidification due to the addition of the heat resistance imparting agent carbon black-1 to 3, the change in the hardness and the thermal conductivity of Examples 13C1 to C3 after heat aging at 180°C was further suppressed, and the case was evaluated as (particularly good: ) on the basis of no addition (Example 13) (good: ). The results are shown in Table 5.

[0313]

[0314] [Summary]

[0315] As shown in Table 1, Examples 1 to 4 in which each component related to the present application was contained in an amount within the prescribed range showed a thermal conductivity of more than 11 W / m-K, and an extrusion amount of more than 50 g / min, showing good workability.

[0316] On the other hand, Comparative Example 1 in which component (B) was not formulated, although the thermal conductivity was more than 9 W / m-K, the extrusion amount was 26 g / min, and failed to exceed 30 g / min showing sufficient extrusion workability. In addition, the composition of Comparative Example 2 in which component (B) was not formulated did not become a paste, and the thermal conductivity could not be measured.

[0317] As shown in Table 2, Examples 5 and 6 in which each component related to the present application was contained in an amount within the prescribed range showed a thermal conductivity of more than 9 W / m-K, and an extrusion amount of more than 60 g / min, showing good workability.

[0318] Comparative Example 3 in which component (D) was contained in an amount of more than 30 vol% outside the prescribed range showed a thermal conductivity of less than 9 W / m-K, 8.9 W / m-K. Similarly, Comparative Examples 4 and 5 in which component (C) was not contained outside the prescribed range showed a thermal conductivity of 7.6 W / m-K and 8.7 W / m-K, respectively.

[0319] As shown in Table 3, Example 7 in which each component related to the present application was contained in an amount within the prescribed range showed a thermal conductivity of 9.1 W / m-K, and an extrusion amount of 40 g / min, showing good workability.

[0320] Comparative Example 6 in which component (C) was contained in an amount of more than 20 vol% outside the prescribed range showed a thermal conductivity of less than 9 W / m-K, 8.2 W / m-K.

[0321] As shown in Table 4, Examples 8 to 11 in which each component related to the present application was contained in an amount within the prescribed range showed a thermal conductivity of more than 11 W / m-K, and an extrusion amount of more than 30 g / min, showing good workability. The E-type hardness after curing was also 60 or less.

[0322] Comparative Example 7 in which component (C) was contained in an amount of more than 20 vol% outside the prescribed range showed an E-type hardness after curing of 62, which exceeded 60, and thus the stress relaxation properties and softness were impaired.

[0323] As shown in Table 5, Examples 12 and 13 in which each component related to the present application was contained in an amount within the prescribed range showed a thermal conductivity of more than 11 W / m-K, and an extrusion amount of more than 30 g / min, showing good workability. In particular, by using component (E4) having a specific siloxane polymerization degree, the extrusion amount was more than 30 g / min, showing good workability. In addition, the E-type hardness after curing was 60 or less. Furthermore, by adding carbon black in Example 13 (Examples 13C1 to C3), it was confirmed that the heat resistance at 180°C after curing could be further improved compared to Example 13.

[0324] [SUMMARY]

[0325] From the results of Examples 1 to 13, it was found that the heat conductive organic silicone composition containing each component in the amount within the prescribed range according to the present application had a thermal conductivity of 9 W / m-K or more and an extrusion amount of 30 g / min or more. Therefore, the workability was good, and sufficient heat dissipation properties were expected to be achieved. Furthermore, in the case where the composition was designed to have a curing reactivity, since the E-type hardness of the cured product thereof was 60 or less, the stress relaxation properties and softness were not impaired.

[0326] On the other hand, from Comparative Examples 1 to 7, it was found that in the case where the blending amounts of the component (C) and the component (D) were outside the range of the claim of the present application, the composition according to these comparative examples had a thermal conductivity of 9 W / m-K or less or an extrusion amount of 30 g / min or less, and thus there were concerns that the workability was poor or sufficient heat dissipation properties could not be achieved. In addition, in the case where the composition having a curing reactivity in the comparative examples was cured, since the E-type hardness of the obtained cured product was 60 or more, the stress relaxation properties and softness were impaired.

Claims

1. A thermally conductive composition, characterized in that, contain: (A) At least one thermally conductive filler selected from zinc oxide powder and alumina powder, with an average particle size in the range of 0.1 to 1.0 μm; (B) At least one thermally conductive filler selected from amorphous, spherical and polyhedral aluminum nitride powder and aluminum oxide powder with an average particle size in the range of 2.0 to 29 μm; (C) Aluminum nitride powder with an average particle size of 30 μm or more, selected from amorphous, spherical and polyhedral forms; (D) Aluminum nitride powder with an average particle size exceeding 50 μm and being spherical; (E) Selected from one or more of the following components (E1) to (E3): (E1) From general formula (1): [Chemical Formula 1] (where R) 1 R is an independent, unsubstituted or substituted monovalent hydrocarbon group without a carbon-carbon double bond. 2 Organopolysiloxanes, which are independently represented by hydrogen atoms, alkyl groups, alkoxyalkyl groups or acyl groups, where a is an integer from 5 to 250 and b is an integer from 1 to 3, and have a viscosity of 10 to less than 10,000 mPa·s at 25°C; (E2) From general formula (2): R alk R 3 2SiO(R 3 2SiO) c R 3 2Si-R 4 -SiR 3 (3-d) (OR 5 ) d (where R) alk It is an alkenyl group, R 3 R is an independent, unsubstituted or substituted monovalent hydrocarbon group without a carbon-carbon double bond. 4 R is an oxygen atom or a divalent hydrocarbon group. 5 A siloxane compound whose molecular chain ends have an alkenyl group and a hydrolyzable silane group, which are independently represented by a hydrogen atom, an alkyl group, an alkoxyalkyl group or an acyl group, where c is an integer from 1 to 250 and d is an integer from 1 to 3, and whose viscosity at 25°C is in the range of 10 to 10,000 mPa·s. as well as (E3) Alkoxysilanes or their hydrolytic condensates having an alkyl group having 6 or more carbon atoms in the molecule; as well as (F) One or more matrix polymers with a viscosity at 25°C in the range of 10 to 1,000,000 mPa·s. and, The thermally conductive filler comprising components (A) to (D) is present in an amount ranging from 60% to 90% by volume relative to the total solid components in the composition. The content of component (C) is an amount in the range of 1.0 to 20.0% by volume relative to the total solid components in the composition. The content of component (D) is in the range of 0.0 to 30.0% by volume relative to the total solid components in the composition.

2. The thermally conductive composition according to claim 1, characterized in that, The thermally conductive filler containing components (A) to (D) is surface-treated using at least a portion of component (E).

3. The thermally conductive composition according to claim 1, wherein, The thermally conductive filler containing components (A) to (D) substantially does not contain aluminum nitride powder with an average particle size of less than 2.0 μm.

4. The thermally conductive composition according to claim 1, wherein, The content of aluminum nitride powder selected from amorphous, spherical and polyhedral forms in components (B) and (C) is less than 50% by volume relative to the solid components in the composition as a whole.

5. The thermally conductive composition according to claim 1, wherein, The total content of thermally conductive fillers, which are aluminum nitride powder, is less than 60% by volume, relative to the total solid components in the composition.

6. The thermally conductive composition according to claim 1, wherein, Component (F) is one or more organopolysiloxanes with a viscosity of 10 to 1,000,000 mPa·s at 25°C.

7. The thermally conductive composition according to claim 1, wherein, Component (F) is one or more organopolysiloxanes selected from organopolysiloxanes that do not have curing reactive groups containing carbon-carbon double bonds in the molecule of (F1) and organopolysiloxanes that have curing reactive groups containing carbon-carbon double bonds in the molecule of (F2).

8. The thermally conductive composition according to claim 1, wherein, Component (F) contains at least one organopolysiloxane with a curing reactive group containing a carbon-carbon double bond within the molecule (F2), and contains: (G) an organohydrogen polysiloxane, wherein, relative to 1 mole of the curing reactive group with carbon-carbon double bonds contained in component (F), the amount of silicon atoms bonded to hydrogen atoms in component (G) is 0.2 to 5 moles; and (H) Catalytic amount of catalyst for hydrosilylation reaction.

9. The thermally conductive composition according to claim 1, The thermally conductive composition further contains a (K) heat-resistant agent.

10. The thermally conductive composition according to claim 9, wherein, The component (K) is a heat-resistance imparting agent containing at least a portion of a component selected from (K1) phthalocyanine compounds and (K2) carbon black.

11. The thermally conductive composition according to claim 1, wherein the thermally conductive composition further contains (J) at least one selected from fatty acids, fatty acid esters and fatty acid metal salts.

12. The thermally conductive composition according to claim 11, wherein, The component (J) is (J1) selected from one or more of stearic acid, alkali metal salts of stearic acid, and alkaline earth metal salts of stearic acid.

13. The thermally conductive composition according to claim 1, wherein, Component (E) contains component (E1), and in general formula (1), a is a number in the range of 40 to 90, and b is 3.

14. The thermally conductive composition according to any one of claims 1 to 13, characterized in that, The composition or its cured reactant has a thermal conductivity of 9.0 W / mK or higher.

15. A thermally conductive component, said thermally conductive component being composed of any one of the thermally conductive compositions or their cured reactants according to claims 1 to 13.

16. A heat dissipation structure comprising the thermally conductive component as described in claim 15.

17. A heat dissipation structure, wherein the heat dissipation structure is formed by providing a heat dissipation member on a heat dissipation component or a circuit board on which the heat dissipation component is mounted, via a thermally conductive composition or a cured product thereof as described in any one of claims 1 to 13.

18. The heat dissipation structure according to claim 16 or claim 17, wherein the heat dissipation structure is an electrical / electronic device.

19. The heat dissipation structure according to claim 16 or claim 17, wherein the heat dissipation structure is an electrical / electronic component or a secondary battery.

20. A method for manufacturing a thermally conductive composition according to any one of claims 1 to 13, the method comprising a step of mixing the components (A) to (D), component (E) and component (F) and then heating and mixing the mixture, followed by a step of mixing other components.

21. A method for manufacturing a heat dissipation structure, the method comprising a step of applying the thermally conductive composition according to any one of claims 1 to 13 onto a heat dissipation component or a circuit board on which the heat dissipation component is mounted, and curing it at a temperature of less than 130°C.

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