Resin composition, heat radiating member, and electronic device

Abstract

This resin composition contains (A) a silicone resin or a silicone oil, (B) a compound having a specific structure, and (C) a heat-conductive filler.　The present invention is capable of providing a resin composition that has good heat conductivity and shows little change in physical properties under a high temperature.

Description

Technical Field

[0001] The present invention relates to a resin composition, a heat radiating member formed from the composition, and an electronic component including the heat radiating member.

Background Art

[0002] In recent years, due to the increasing heat generation associated with the high integration of circuits in electronic devices, heat countermeasures have become important, and the demand for heat dissipation materials for this purpose has been increasing. Examples of the form of the heat dissipation material include sheets and greases. In particular, in recent years, for high heat dissipation, heat dissipation materials in which a heat conductive filler such as alumina is highly filled in a silicone resin have been widely used. In order to obtain a heat dissipation material having high thermal conductivity, when trying to highly fill a heat conductive filler in silicone serving as a binder, the fluidity decreases as the amount of silicone decreases. To solve this problem, a method of surface-treating the heat conductive filler using various surface treatment agents (such as alkoxysilane and organopolysiloxane containing an alkoxy group) is known. For example, Patent Documents 1 to 3 describe inventions related to a thermally conductive silicone composition containing a silicone resin, a thermally conductive filler, and an organopolysiloxane having a hydrolyzable group.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0004] Conventionally used thermally conductive silicone compositions have been unable to sufficiently improve the reduction in fluidity when blending a thermally conductive filler into silicone, and thus it has been difficult to increase the thermal conductivity to a desired value. In addition, the viscosity of the composition increases with time at high temperatures, or the hardness of the composition after curing increases with time, etc., and physical property changes of the composition at high temperatures are likely to occur, leaving room for improvement. Further, in the case of a thermally conductive filler having a low activity of surface functional groups, it has been difficult to obtain a sufficient effect of reducing viscosity with a conventional surface treatment agent.

[0005] Therefore, an object of the present invention is to provide a resin composition having good thermal conductivity and little change in physical properties at high temperatures, a heat radiating member formed of the composition, and an electronic device including the heat radiating member.

Means for Solving the Problems

[0006] As a result of intensive studies to achieve the above object, the present inventors have found that the above problems can be solved by a resin composition containing a silicone resin or silicone oil, a thermally conductive filler, and a specific compound, and have completed the present invention. That is, the present invention relates to the following [1] to

[11] .

[0007] [1] A resin composition containing (A) a silicone resin or silicone oil, (B) a compound represented by the following general formula (1) or (2), and (C) a thermally conductive filler.

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[10] A heat radiating member formed of the resin composition according to any one of [1] to [5] above.

[11] An electronic device including an electronic component and the heat radiating member according to [9] above disposed on the electronic component.

Advantages of the Invention

[0008] According to the present invention, there is provided a resin composition having good thermal conductivity and little change in physical properties at high temperatures, a heat radiating member formed of the composition, and an electronic device including the heat radiating member.

Embodiments for Carrying Out the Invention

[0009] The resin composition of the present invention is a resin composition containing (A) a silicone resin or silicone oil, (B) a compound represented by the following general formula (1) or (2), and (C) a heat conductive filler.

[0010]

Chem.

Chem.

[0011] In the above formulas (1) and (2), R 1 is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a plurality of R 1 may be the same or different from each other. R 2 is an alkyl group having 1 to 4 carbon atoms, and when there are a plurality of R 2 , the plurality of R 2 may be the same or different from each other. R 3 is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group having 2 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an acyl group, and when there are a plurality of R 3 , the plurality of R 3 may be the same or different from each other. R 4 is an alkyl group having 1 to 8 carbon atoms, R 5 is an alkylene group having 2 to 20 carbon atoms, a plurality of R 5 may be the same or different from each other, a is an integer of 0 to 2, and n is an integer of 4 to 150.

[0012] <(B) Compound represented by the general formula (1) or (2) ((B) compound)> In the present invention, a compound (B) represented by the general formula (1) or (2) (hereinafter may be simply referred to as (B) compound) is used. By using the (B) compound, the surface treatment of the (C) thermally conductive filler described below is performed. As a result, the dispersibility of the (C) thermally conductive filler in the resin composition is improved, and as a result, the (C) thermally conductive filler can be highly filled, and the thermal conductivity is increased. That is, the compound (B) functions as a dispersant for the thermally conductive filler. Therefore, the compound (B) can be used as a dispersant.

[0013] In addition, by using the compound (B) of the present invention, changes in the physical properties of the resin composition at high temperatures can be suppressed. This is presumably due to the ester structure of the compound (B). As shown in the following chemical formula, generally, the thermal decomposition behavior of a compound having an ester bond and divalent or higher carbon around it obtains a six-membered ring intermediate structure, obtains hydrogen abstraction at the γ-position of the carbonyl group, and is known to undergo β-cleavage. Therefore, the chemical structure obtained by thermal decomposition has the structure of a carboxylic acid and exhibits high hydrogen bonding properties, so it can interact with the hydroxyl groups on the surface of the metal oxide and the alkoxy groups not bonded to the filler to prevent volatilization.

Chemical formula

[0014] In the compound (B), the compound represented by the general formula (1) is as follows.

Chemical formula

[0015] In the above formula (1), R 1 is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a plurality of R 1 may be the same or different from each other. Further, the alkyl group and the alkenyl group may be linear or branched. Among these, R 1 is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 4 carbon atoms, and even more preferably a methyl group. In the above formula (1), R 2 is an alkyl group having 1 to 4 carbon atoms, and R 2When there are a plurality of them (that is, when a is 2), the plurality of Rs 2 may be the same or different from each other. Further, the alkyl group may be linear or branched. Among them, R 2 is preferably an alkyl group having 1 to 2 carbon atoms, more preferably a methyl group. Also, a is an integer from 0 to 2, preferably a is 0 or 1, and more preferably a is 0.

[0016] In the above formula (1), R 3 is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group having 2 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an acyl group. When there are a plurality of Rs 3 (that is, when a is 0 or 1), the plurality of Rs 3 may be the same or different from each other. Also, the alkyl group, alkoxyalkyl group, alkenyl group, and acyl group in R 3 may be linear or branched. Among these, R 3 is preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group among them.

[0017] In the above formula (1), R 4 is an alkyl group having 1 to 8 carbon atoms, preferably an alkyl group having 2 to 6 carbon atoms, and more preferably a butyl group. In the above formula (1), R 5 is an alkylene group having 2 to 20 carbon atoms, and the plurality of Rs 5 may be the same or different from each other. Also, the alkylene group may be linear or branched. R 5 is preferably an alkylene group having 2 to 10 carbon atoms, more preferably an alkylene group having 2 to 8 carbon atoms, still more preferably an alkylene group having 2 to 4 carbon atoms, and even more preferably an alkylene group represented by -CH2-CH2-CH2- or -CH(CH3)-CH2-.

[0018] In the above formula (1), n represents the number of repetitions, which is an integer from 4 to 150, preferably an integer from 5 to 120, more preferably an integer from 9 to 130, and still more preferably an integer from 8 to 50. When n is within the above-specified range, the dispersibility of the thermal conductive filler can be improved with a relatively small amount, and furthermore, the change in physical properties at high temperatures can be reduced.

[0019] Among the compounds represented by the above formula (1), from the viewpoint of enhancing the dispersibility of the thermal conductive filler and obtaining a resin composition with little change in physical properties at high temperatures, the compounds shown below are particularly preferred.

Chemical formula

[0020] In the (B) compound, the compound represented by the general formula (2) is as follows.

Chemical formula

[0021] Among the compounds represented by the above formula (2), from the viewpoint of enhancing the dispersibility of the thermal conductive filler and obtaining a resin composition with little change in physical properties at high temperatures, the compounds shown below are particularly preferred.

Chemical formula

[0022] (B) The compounding amount of the compound is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and even more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the (C) thermally conductive filler. With such a compounding amount, the surface treatment of the (C) thermally conductive filler with the (B) compound is appropriately performed, and the dispersibility of the (C) thermally conductive filler is likely to be improved.

[0023] <Manufacturing method of the (B) compound> The manufacturing method of the (B) compound in the present invention is not particularly limited. For example, the compound represented by the above formula (1) can be obtained by a hydrosilylation reaction of the compound represented by the following formula (3) and the compound represented by the following formula (4). [Chemical formula] R in the above formulas (3) and (4) 1 ~R 5 , n, and a have the same meanings as those in formula (1). R in formula (3) 6 is an alkenyl group having 2 to 10 carbon atoms, preferably an alkenyl group having 2 to 4 carbon atoms, and more preferably a group represented by -C(CH3)=CH2. Also, R 6 is a group that reacts with SiH in the above formula (4) to form R 5 .

[0024] The hydrosilylation reaction of the compound represented by formula (3) and the compound represented by formula (4) is carried out using a hydrosilylation catalyst. The hydrosilylation catalyst is not particularly limited as long as it is a catalyst generally used in hydrosilylation reactions. For example, a platinum-based catalyst such as platinum alone or platinum supported on a carrier such as alumina, silica, or carbon black can be used. The hydrosilylation reaction between the compound represented by formula (3) and the compound represented by formula (4) may be carried out in the presence or absence of a solvent. As the solvent when reacting in the presence of a solvent, for example, toluene, hexane, acetone, etc. can be used. The reaction temperature is preferably 70 to 150 °C, and the reaction time is preferably 0.5 to 2 hours. The mixing ratio of the compound represented by formula (3) and the compound represented by formula (4) is not particularly limited, but it is preferable that the compound represented by formula (4) is 0.9 to 1.1 moles with respect to 0.9 to 1.1 moles of the compound represented by formula (3).

[0025] The compound represented by the above formula (2) can be obtained by the hydrosilylation reaction between the compound represented by the following formula (3) and the compound represented by the following formula (5).

Chemical formula

[0026] Each reaction condition such as the catalyst used in the hydrosilylation reaction between the compound represented by formula (3) and the compound represented by formula (5), the reaction temperature, the reaction time, and the solvent used when reacting in the presence of a solvent is the same as the hydrosilylation reaction between the compound represented by formula (3) and the compound represented by formula (4) described above. The mixing ratio of the compound represented by formula (3) and the compound represented by formula (5) is not particularly limited, but it is preferable that the compound represented by formula (5) is 0.9 to 1.1 moles with respect to 1.8 to 2.2 moles of the compound represented by formula (3).

[0027] <(C)Thermally Conductive Filler> In the present invention, a (C) thermally conductive filler is used. The (C) thermally conductive filler becomes a surface-treated thermally conductive filler by the above-described (B) compound, thereby improving the dispersibility in the resin composition or the cured product of the resin composition and increasing the thermal conductivity. The (C) thermally conductive filler is not particularly limited, but is preferably at least one selected from the group consisting of metal oxides, metal nitrides, carbides, carbon-based materials, and metal hydroxides. Examples of the metal oxide include iron oxide, zinc oxide, silicon oxide (silica), alumina, magnesium oxide, titanium oxide, cerium oxide, and zirconium oxide. Examples of the metal nitride include silicon nitride, aluminum nitride, gallium nitride, chromium nitride, tungsten nitride, magnesium nitride, molybdenum nitride, lithium nitride, and boron nitride. Examples of the carbide include silicon carbide, boron carbide, aluminum carbide, titanium carbide, and tungsten carbide. Examples of the carbon-based material include diamond particles, carbon black, graphite, graphene, fullerene, carbon nanotube, and carbon nanofiber. Examples of the metal hydroxide include aluminum hydroxide, calcium hydroxide, and magnesium hydroxide. These thermally conductive fillers may be used alone or in combination of two or more.

[0028] Among the above, the (C) thermally conductive filler is preferably at least one selected from the group consisting of alumina, diamond, and aluminum nitride from the viewpoint of being surface-treated by the above-described (B) compound, enhancing the dispersibility in the resin composition, and easily improving the thermal conductivity.

[0029] (C) The average particle diameter of the primary particles of the thermally conductive filler is not particularly limited, but is preferably 0.1 μm or more and 250 μm or less, and more preferably 0.2 μm or more and 100 μm or less. Incidentally, the average particle diameter of the primary particles can be measured, for example, using a "laser diffraction particle size distribution measuring device" manufactured by Horiba, Ltd., and the particle diameter (d50) when the cumulative volume is 50% may be taken as the average particle diameter of the primary particles.

[0030] (C) The thermally conductive filler preferably contains two or more types of particles having different average particle diameters of the primary particles. When using two or more types of particles having different average particle diameters of the primary particles, the particles with the smaller average particle diameter can enter between the particles with the larger average particle diameter, making it easier to increase the filling rate of the thermally conductive filler while appropriately dispersing the thermally conductive filler in the silicone resin or silicone oil. Incidentally, in the particle size distribution of the thermally conductive filler, it can be determined that the resin composition has two or more types of particles having different average particle diameters of the primary particles by the appearance of two or more peaks.

[0031] (C) When the thermally conductive filler contains two or more types of particles having different average particle diameters of the primary particles, the specific particle diameters can be selected according to the type of the thermally conductive filler. For example, it is preferable to use a mixture of particles with an average particle diameter of the primary particles of 10 μm or more and 250 μm or less (large particle diameter thermally conductive filler) and a thermally conductive filler with an average particle diameter of the primary particles of 0.1 μm or more and less than 10 μm (small particle diameter thermally conductive filler). Furthermore, it is also preferable that the large particle diameter thermally conductive filler contains two or more types of particles having different average particle diameters of the primary particles.

[0032] (C) As the type of the thermally conductive filler, those described above can be used. Also, as described above, as the thermally conductive filler, it is preferably at least one selected from the group consisting of alumina, diamond, and aluminum nitride.

[0033] <Alumina> (C) When using alumina as the thermal conductivity filler, it is preferable to include two or more types of particles having different average primary particle diameters. When using two or more types of particles with different average particle diameters, the particles with the smaller average particle diameter can penetrate between the particles with the larger average particle diameter, making it easier to appropriately disperse the alumina in the silicone resin and increase the filling rate of the alumina.

[0034] When alumina contains two or more types of particles with different average primary particle diameters, the alumina is preferably a mixture of particles having an average primary particle diameter of 10 μm or more and 250 μm or less (hereinafter also referred to as "large particle size alumina") and particles having an average primary particle diameter of more than 0.1 μm and less than 10 μm (hereinafter also referred to as "small particle size alumina").

[0035] When alumina contains both small particle size alumina and large particle size alumina, the mass ratio of large particle size alumina to small particle size alumina (large particle size / small particle size) is, for example, 0.1 or more and 50 or less, preferably 1 or more and 15 or less, more preferably 5 or more and 15 or less. With such a mass ratio, the alumina is likely to be filled in the silicone resin or silicone oil, and the thermal conductivity is likely to be good.

[0036] The large particle size alumina preferably has an average primary particle diameter of 12 μm or more and 100 μm or less, and more preferably 15 μm or more and 80 μm or less. The small particle size alumina preferably has an average primary particle diameter of 0.2 μm or more and 5 μm or less, and preferably 0.2 μm or more and 3 μm or less.

[0037] <Diamond> (C) When using diamond as the thermal conductivity filler, it is preferable to include two or more types of particles having different average primary particle diameters. When using two or more types of particles with different average particle diameters, the particles with the smaller average particle diameter can penetrate between the particles with the larger average particle diameter, making it easier to appropriately disperse the diamond in the silicone resin or silicone oil and increase the filling rate of the diamond.

[0038] When the diamond contains two or more kinds of particles having different average particle diameters of primary particles, the diamond is preferably a mixture of particles having an average particle diameter of primary particles of 10 μm or more and 250 μm or less (hereinafter also referred to as "large particle diameter diamond") and particles having an average particle diameter of primary particles of 0.1 μm or more and less than 10 μm (hereinafter also referred to as "small particle diameter diamond").

[0039] When the diamond contains both small particle diameter diamond and large particle diameter diamond, the mass ratio of the large particle diameter diamond to the small particle diameter diamond (large particle diameter / small particle diameter) is, for example, 0.5 or more and 20 or less, preferably 1 or more and 15 or less, more preferably 2 or more and 8 or less. With such a mass ratio, the diamond is likely to be filled with a silicone resin or a silicone oil, and the thermal conductivity is likely to be good.

[0040] The large particle diameter diamond is more preferably such that the average particle diameter of its primary particles is 15 μm or more and 150 μm or less, and even more preferably 18 μm or more and 100 μm or less. In addition, the large particle diameter diamond preferably contains two or more kinds of particles having different average particle diameters of primary particles. Thereby, the diamond is likely to be filled with a silicone resin or a silicone oil, and the thermal conductivity is likely to be better.

[0041] The small particle diameter diamond is preferably such that the average particle diameter of its primary particles is 0.5 μm or more and 8 μm or less, and preferably 1 μm or more and 5 μm or less. In addition, the small particle diameter diamond preferably contains two or more kinds of particles having different average particle diameters of primary particles. Thereby, the diamond is likely to be filled with a silicone resin or a silicone oil, and the thermal conductivity is likely to be better.

[0042] <aluminum nitride> (C) When using aluminum nitride as the thermal conductivity filler, it is preferable to include two or more types of particles having different average particle diameters of the primary particles. When using two or more types of particles having different average particle diameters, the particles with the smaller average particle diameter can enter between the particles with the larger average particle diameter, facilitating appropriate dispersion of aluminum nitride in the silicone resin and increasing the filling rate of aluminum nitride.

[0043] When aluminum nitride contains two or more types of particles having different average particle diameters of the primary particles, aluminum nitride is preferably a mixture of particles having an average particle diameter of the primary particles of 10 μm or more and 250 μm or less (hereinafter also referred to as "large particle diameter aluminum nitride") and particles having an average particle diameter of the primary particles of 0.1 μm or more and less than 10 μm (hereinafter also referred to as "small particle diameter aluminum nitride").

[0044] When aluminum nitride contains both small particle diameter aluminum nitride and large particle diameter aluminum nitride, the mass ratio of large particle diameter aluminum nitride to small particle diameter aluminum nitride (large particle diameter / small particle diameter) is, for example, 0.2 or more and 20 or less, preferably 0.3 or more and 10 or less, more preferably 0.5 or more and 5 or less. With such a mass ratio, aluminum nitride is easily filled into the silicone resin, and the thermal conductivity tends to be good.

[0045] It is more preferable that the average particle diameter of the primary particles of the large particle diameter aluminum nitride is 10 μm or more and 100 μm or less, and even more preferably 10 μm or more and 80 μm or less. In addition, the large particle diameter aluminum nitride preferably contains two or more types of particles having different average particle diameters of the primary particles. This makes it easier for aluminum nitride to be filled with silicone resin or silicone oil, and the thermal conductivity tends to be better.

[0046] It is preferable that the average particle diameter of the primary particles of the small particle diameter aluminum nitride is 1 μm or more and 8 μm or less, and preferably 2 μm or more and 7 μm or less. Note that the small-sized aluminum nitride may contain particles with different average particle diameters of two or more primary particles.

[0047] (C) When the thermally conductive filler is contained in the resin composition, the amount of the (C) thermally conductive filler is preferably 50% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more based on the total amount of the resin composition. When the amount of the thermally conductive filler is at or above these lower limits, it becomes easier to improve the thermal conductivity of the resin composition or its cured product.

[0048] In addition, the (C) thermally conductive filler of the present invention can be a surface-treated thermally conductive filler using the above-mentioned (B) compound. The surface-treated thermally conductive filler can be obtained by mixing the above-mentioned (B) compound and the (C) thermally conductive filler. Also, from the viewpoint of facilitating the promotion of surface treatment during mixing, it is preferable to use a wet treatment method, a dry treatment method, or the like. In the wet treatment method, for example, the (C) thermally conductive filler may be added and mixed into a solution in which the above-mentioned (B) compound is dispersed or dissolved, and then heat-treated to bond or adhere the (B) compound to the surface of the thermally conductive filler. The dry treatment method is a method of surface treatment without using a solution. Specifically, it is a method of mixing the (C) thermally conductive filler and the above-mentioned (B) compound and stirring with a mixer or the like, and then heat-treating to bond or adhere the (B) compound to the surface of the thermally conductive filler. Note that the surface treatment performed by mixing the (C) thermally conductive filler and the (B) compound can also be performed in the presence of the (A) silicone resin or silicone oil described later. The blending amount of the (B) compound to be used is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and still more preferably 1 to 10 parts by mass with respect to 100 parts by mass of the (C) thermally conductive filler.

[0049] <(A) silicone resin or silicone oil> The resin composition of the present invention contains (A) a silicone resin or silicone oil, (B) a compound, and (C) a thermally conductive filler.

[0050] (Silicone resin) The type of silicone resin is not particularly limited, but condensation-curing type silicone resins, addition-reaction curing type silicone resins, etc. are preferable, and addition-reaction curing type silicone resins are more preferable.

[0051] The addition-reaction curing type silicone resin preferably consists of a silicone compound as the main agent and a curing agent for curing the main agent. The silicone compound used as the main agent is preferably an organopolysiloxane having an alkenyl group. Examples of the alkenyl group include those having 2 to 6 carbon atoms such as vinyl group, allyl group, 1-butenyl group, 1-hexenyl group, etc., and the vinyl group is preferable in terms of ease of synthesis and cost. Also, the silicone compound used as the main agent may have one or more alkenyl groups, but generally has two or more.

[0052] Specific examples of the organopolysiloxane having an alkenyl group include vinyl-terminated organopolysiloxanes such as vinyl-terminated polydimethylsiloxane, vinyl-terminated polyphenylmethylsiloxane, vinyl-terminated dimethylsiloxane-diphenylsiloxane copolymer, vinyl-terminated dimethylsiloxane-phenylmethylsiloxane copolymer, vinyl-terminated dimethylsiloxane-diethylsiloxane copolymer. As the silicone compound used as the main agent, for example, those having a viscosity at 25°C of 1000 mPa·s or less may be used, preferably 50 mPa·s or more, more preferably 80 mPa·s or more and 800 mPa·s or less, and still more preferably 100 mPa·s or more and 500 mPa·s or less.

[0053] As the curing agent used for the addition reaction-curable silicone resin, there is no particular limitation as long as it can cure the above-described silicone compound serving as the main agent. However, organohydrogenpolysiloxane, which is an organopolysiloxane having two or more hydrosilyl groups (SiH), is preferable. Examples of the organohydrogenpolysiloxane include methylhydrogensiloxane-dimethylsiloxane copolymer, polymethylhydrogensiloxane, polyethylhydrogensiloxane, methylhydrogensiloxane-phenylmethylsiloxane copolymer, and the like. These may or may not contain a hydrosilyl group at the terminal. The viscosity of the curing agent at 25°C is preferably 1000 mPa·s or less, preferably 50 mPa·s or more, more preferably 100 mPa·s or more and 900 mPa·s or less, and still more preferably 100 mPa·s or more and 600 mPa·s or less. When the viscosity ranges of the above-described main agent and curing agent are within the above ranges, the viscosity of the resin composition can be lowered, so that the workability is improved. In addition, after appropriately dispersing the heat conductive filler, it becomes easy to blend a large amount into the resin composition.

[0054] In addition, when using a silicone resin, a curing catalyst is usually blended. Examples of the curing catalyst include platinum-based catalysts, palladium-based catalysts, rhodium-based catalysts, etc. Among these, platinum-based catalysts are preferable. The curing catalyst is a catalyst for curing the silicone compound serving as the raw material of the silicone resin and the curing agent. The blending amount of the curing catalyst is usually 0.1 to 200 ppm, preferably 0.5 to 100 ppm, based on the total mass of the silicone compound and the curing agent.

[0055] The silicone resin may be either a one-component curing type or a two-component curing type. In the case of the two-component curing type, it is preferable to prepare a resin composition by mixing one component containing the above-described main agent and two components containing the curing agent. In the case of the two-component curing type, the (C) heat conductive filler and the (B) compound may be blended in either one or both of the one component and the two components. When using silicone oil (B) In the compound, it is desirable to use the compound represented by the general formula (1) and the compound represented by the general formula (2) in combination, which is more effective than using them alone, and it is effective for a one-component non-curing heat dissipation compound from the viewpoint of suppressing voids generated when standing at a high temperature after coating.

[0056] (Silicone oil) The silicone oil is preferably a non-reactive silicone oil having no reactive groups such as alkoxy groups or silanol groups in the molecule. Examples of the silicone oil include straight silicone oil, modified silicone oil, etc., and straight silicone oil is preferred. Examples of the straight silicone oil include polyorganosiloxanes such as dimethyl silicone oil and phenylmethyl silicone oil. Examples of the modified silicone oil include polyether-modified silicone oil, aralkyl-modified silicone oil, fluoroalkyl-modified silicone oil, long-chain alkyl-modified silicone oil, higher fatty acid ester-modified silicone oil, higher fatty acid amide-modified silicone oil, and phenyl-modified silicone oil.

[0057] The viscosity of the silicone oil at 25°C is preferably 20 mPa·s or more and 500 mPa·s or less, more preferably 50 mPa·s or more and 300 mPa·s or less, and even more preferably 80 mPa·s or more and 150 mPa·s or less.

[0058] (A) The content of the silicone resin or silicone oil is preferably 0.1 to 30 parts by mass, more preferably 0.5 to 20 parts by mass, and even more preferably 1 to 15 parts by mass with respect to 100 parts by mass of the (C) heat conductive filler.

[0059] As described above, the resin composition of the present invention is a resin composition containing (A) a silicone resin or silicone oil, (B) a compound, and (C) a heat conductive filler. The order of blending these components is not particularly limited, but all of these components can be mixed to prepare the resin composition. In this case, in the composition, the above (B) compound adheres to or reacts with the surface of the (C) heat conductive filler, thereby enhancing the dispersibility of the heat conductive filler in the silicone resin or silicone oil. Alternatively, first, the above (B) compound and (C) heat conductive filler may be mixed to cause the above (B) compound to adhere to or react with the surface of the (C) heat conductive filler, and then, a silicone resin or silicone oil may be further mixed to prepare a resin composition. Also, as described above, it may be prepared by mixing a previously prepared one-component liquid and a two-component liquid. When preparing each of the one-component liquid and the two-component liquid, various components may be similarly mixed and prepared.

[0060] In the present invention, in addition to the resin composition containing all of the above (A) to (C), a resin composition containing (A) a silicone resin or silicone oil and (B) a compound can also be provided. The resin composition containing (A) a silicone resin or silicone oil and (B) a compound can be used as a composition for filling a heat conductive filler, and the (C) heat conductive filler can be appropriately blended and used.

[0061] The resin composition of the present invention may contain additives such as an antioxidant, a heat stabilizer, a colorant, a flame retardant, and an antistatic agent, if necessary.

[0062] Using the resin composition of the present invention as a raw material, a heat radiating member formed of the resin composition can be produced. For example, after the resin composition is formed into a predetermined shape, it can be formed into a heat radiating member having a predetermined shape by appropriately heating and curing it. The heat dissipation member can be used inside an electronic device. For example, it can be an electronic device including an electronic component and a heat dissipation member disposed on the electronic component. Specifically, the heat dissipation member can be disposed between an electronic component such as a semiconductor element and a heat sink to effectively dissipate the heat generated from the electronic component.

Examples

[0063] Hereinafter, the present invention will be clarified by giving specific examples and comparative examples of the present invention. Note that the present invention is not limited to the following examples.

[0064] The evaluation methods for the samples prepared in each example and comparative example are as follows. When a silicone resin is used as the component (A), the "hardness change rate" is used. When a silicone oil is used as the component (A), the "viscosity change rate" or the "penetration load change rate" is used to evaluate the magnitude of the physical property change at high temperature.

[0065] [Hardness change rate] From the initial hardness of the cured product of the resin composition prepared in each example and comparative example and the hardness after heat treatment at 150 °C for 200 hours, the change rate of hardness was determined by the following formula. Hardness change rate (%) = [(hardness after heat treatment - initial hardness) / initial hardness] × 100 The hardness was measured using an automatic hardness measuring device, "GX-02E" manufactured by Techlock Co., Ltd.

[0066] [Viscosity change rate] From the initial viscosity of the resin composition prepared in each example and comparative example and the viscosity after heat treatment at 150 °C for 200 hours, the viscosity change rate was determined by the following formula. Viscosity change rate (%) = [(viscosity after heat treatment - initial viscosity) / initial viscosity] × 100 The viscosity was measured at 23 °C using a Brookfield B-type viscometer. As the measuring device, "HB DVE" manufactured by Eihiro Seiki Co., Ltd. was used.

[0067] [Penetration Load Change Rate] From the penetration load in the initial state of the resin compositions prepared in each example and comparative example and the penetration load after heat treatment at 150°C for 200 hours, the penetration load change rate was determined by the following formula. Penetration Load Change Rate (%) = [(Penetration Load after Heat Treatment - Penetration Load in Initial State) / Penetration Load in Initial State] × 100 The penetration load was measured by piercing a needle into the sample and measuring the load when it reached a depth of 6 mm from the surface. The measurement of the penetration load was performed using a penetration load measuring machine, the digital force gauge "ZTS-5N" manufactured by IMADA Co., Ltd., and the pushing-in was measured under the conditions of a needle diameter of 1 mmφ, a pushing-in speed of 10 mm / min, and a measurement temperature of 23°C.

[0068] [Thermal Conductivity] The thermal conductivity was measured at 23°C in accordance with ASTM D5470. The measurement was performed using the "T3Ster DynTIM Tester" of Mentor, a Siemens Business. [Gloss] Performed in accordance with JIS K-2220, and the measurement was performed using a 1 / 4 cone. [Void Ratio] The paste-like resin composition applied with 0.5 g on the alumina substrate was pressed with a glass plate so as to have a thickness of 1 mm and stored at 150°C for 24 hours in a fixed state. The void ratio was calculated as the ratio of the generated area of voids observed after storage to the entire area of the paste-like resin composition. [Judgment Criteria] The judgment of the void ratio was made according to the following criteria. A... Void ratio is 10% or less B... Void ratio is more than 10% and 15% or less C... Void ratio is more than 15% and 20% or less

[0069] Each component used in each example and comparative example is as follows. <Component (A): Silicone Resin> Addition reaction type silicone resin Main agent: Vinyl-terminated organopolysiloxane (viscosity at 25°C is 300 mPa·s) Hardening agent: Organohydrogenpolysiloxane (viscosity at 25°C is 400 mPa·s) <(A) component: silicone oil> Polyorganosiloxane (viscosity at 25°C is 110 mPa·s)

[0070] <(B) compound> As the compounds represented by the general formula (1), "Treatment agent 1" and "Treatment agent 2", and as the compound represented by the general formula (2), "Treatment agent 5" were produced and used as follows.

[0071] [Production of Treatment agent 1] "KBM-503" manufactured by Shin-Etsu Silicone Co., Ltd. and "MCR-H11" manufactured by Gelest were reacted in the presence of a hydrosilylation catalyst to obtain Treatment agent 1. The reaction temperature was 150°C, the reaction time was 0.5 hours, and the addition amount of "KBM-503" was 1 mol with respect to 1 mol of "MCR-H11".

Chemical formula

[0072] [Production of Treatment agent 2] In the production of Treatment agent 1 described above, Treatment agent 2 was produced using "MCR-H21" manufactured by Gelest instead of MCR-H11. Treatment agent 2 is a compound in which n is 60 to 80 in the structure of Treatment agent 1 described above.

[0073] [Production of Treatment agent 5] In the production of Treatment agent 1 described above, "DMS-H21" was used instead of "MCR-H11" manufactured by Gelest and produced to have the following structure. In this structure, n is 60 to 80.

Chemical formula

[0074] The structures of the compounds used in the comparative examples are as follows. [Treatment agent 3] [Chemical formula] n is 8 - 10 [Treatment agent 4] In the structure of the above treatment agent 3, it is a compound where n is 60 - 80.

[0075] [Decyltrimethoxysilane] [Chemical formula]

[0076] <(C) component: Thermal conductivity filler> ≪Alumina≫ "Alumina 1" Average particle diameter 40 μm "Alumina 2" Average particle diameter 13 μm "Alumina 3", average particle diameter 0.5 μm "Alumina 4", average particle diameter 3 μm ≪Diamond≫ "Diamond 1", average particle diameter 3 μm "Diamond 2", average particle diameter 7 μm "Diamond 3", average particle diameter 10 μm "Diamond 4", average particle diameter 20 μm "Diamond 5", average particle diameter 40 μm "Diamond 6", average particle diameter 70 μm "Diamond 7", average particle diameter 50 μm ≪Aluminum Nitride≫ "Aluminum Nitride 1", average particle diameter 50 μm "Aluminum Nitride 2", average particle diameter 30 μm "Aluminum Nitride 3", average particle diameter 10 μm "Aluminum Nitride 4", average particle diameter 5 μm Note that the average particle diameters of the above Alumina 1-4, Diamond 1-7, and Aluminum Nitride 1-4 are the average particle diameters of the primary particles.

[0077] [Example 1] To 5.2 parts by mass of vinyl-terminated organopolysiloxane (viscosity at 25°C is 300 mPa·s) constituting the main component of the addition reaction type silicone resin, the (B) compound and the (C) thermal conductive filler are added in the compounding parts shown in Table 1 as a dispersant, and further 1.5 parts by mass of a reaction retarder and a catalytic amount of a platinum catalyst are added to prepare one liquid of the resin composition. Also, to 5.2 parts by mass of organohydrogenpolysiloxane (viscosity at 25°C is 400 mPa·s) constituting the curing agent of the addition reaction type silicone resin, the (B) compound and the (C) thermal conductive filler are added in the compounding parts shown in Table 1 as a dispersant to prepare two liquids of the resin composition. After mixing one liquid and two liquids at a mass ratio (one liquid / two liquids) of 1:1, it was poured into a mold and heated at 70°C for 1 hour to allow the curing reaction to proceed. The cured product of the obtained resin composition was stored at 23°C for 12 hours, and the time when no change in hardness was observed was evaluated as the initial hardness of the cured product of the resin composition.

[0078] [Examples 2 to 6, Comparative Examples 1 to 7] A cured product of the resin composition was obtained in the same manner as in Example 1, except that the types and blending amounts of the respective components were changed as shown in Table 1.

[0079] [Examples 7 to 19, Comparative Examples 8 to 14] Silicone oil, a thermally conductive filler, and a dispersant were mixed in the formulations shown in Table 2 to prepare a paste-like resin composition. The resin composition was heated at 150°C for 1 hour, and the state after standing at 23°C for 12 hours was evaluated as the initial state. [Examples 20 to 24] Silicone oil, a thermally conductive filler, and a dispersant were mixed in the formulations shown in Table 3 to prepare a paste-like resin composition. The finish and the void ratio after 24 hours at 150°C were calculated for the prepared resin composition.

[0080]

Table 1

[0081]

Table 2

[0082]

Table 3

[0083] When comparing the Examples and Comparative Examples for resin compositions having the same type and blending amount of the thermally conductive filler, it was found that the rate of change of each physical property was smaller in the Examples than in the Comparative Examples. Further, particularly in the (B) compound contained in the silicone oil, by using a compound having trialkoxy groups at both ends of the silicone chain like the structure of formula (2), a resin composition having more excellent performance can be obtained. From this, it was found that the resin composition of the present invention using the (B) compound having a specific structure has good thermal conductivity and a small rate of change of physical properties at high temperatures.

Claims

1. (A) a silicone resin or a silicone oil, (B) a compound represented by the following general formula (1) or (2), and (C) a heat conductive filler, wherein the content of the (A) silicone resin or silicone oil is 0.1 to 30 parts by mass with respect to 100 parts by mass of the (C) heat conductive filler, and the content of the (B) compound represented by the following general formula (1) or (2) is 0.1 to 20 parts by mass with respect to 100 parts by mass of the (C) heat conductive filler, a resin composition. 【Chemical 1】 【Chemical 2】 In the above formulas (1) and (2), R １ is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a plurality of R １ may be the same or different from each other, R ２ is an alkyl group having 1 to 4 carbon atoms, R ２ when there are a plurality of them, the plurality of R ２ may be the same or different from each other, R ３ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group having 2 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms or an acyl group, R ３ when there are a plurality of them, the plurality of R ３ may be the same or different from each other, R ４ is an alkyl group having 1 to 8 carbon atoms, R ５ is an alkylene group having 2 to 20 carbon atoms, and a plurality of R ５ may be the same or different from each other, a is an integer of 0 to 2, and n is an integer of 4 to 150.

2. The resin composition according to claim 1, wherein the (C) heat conductive filler is at least one selected from the group consisting of metal oxides, metal nitrides, carbides, carbon-based materials, and metal hydroxides.

3. The resin composition according to claim 1 or 2, wherein the (C) heat conductive filler is at least one selected from the group consisting of alumina, diamond, and aluminum nitride.

4. The resin composition according to any one of claims 1 to 3, wherein the (C) heat conductive filler contains two or more kinds of particles having different average particle diameters.

5. The resin composition according to any one of claims 1 to 4, wherein the (A) silicone resin is an addition reaction curable silicone resin.

6. The (B) compound represented by the following general formula (1) or (2). 【Chemical Formula 3】 【Chemical Formula 4】 In the above formulas (1) and (2), R １ is an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and a plurality of R １ may be the same or different from each other, R ２ is an alkyl group having 1 to 4 carbon atoms, and when there are a plurality of R ２ , the plurality of R ２ may be the same or different from each other, R ３ is an alkyl group having 1 to 4 carbon atoms, an alkoxyalkyl group having 2 to 4 carbon atoms, an alkenyl group having 2 to 4 carbon atoms, or an acyl group, and when there are a plurality of R ３ , the plurality of R ３ may be the same or different from each other, R ４ is an alkyl group having 1 to 8 carbon atoms, R ５ is an alkylene group having 2 to 20 carbon atoms, and a plurality of R ５ may be the same or different from each other, a is an integer of 0 to 2, and n is an integer of 4 to 150.

7. The (B) compound according to claim 6, which is used as a dispersant.

8. A heat conductive filler surface-treated with the (B) compound according to claim 6 or 7.

9. A resin composition containing (A) a silicone resin or a silicone oil and the (B) compound according to claim 6 or 7.

10. A heat radiating member formed of the resin composition according to any one of claims 1 to 5.

11. An electronic device including an electronic component and the heat radiating member according to claim 10 disposed on the electronic component.

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