Resin composition

Abstract

To provide a resin composition which has good dischargeability and high thermal conductivity and enables quick room temperature curing.SOLUTION: The composition comprises (A) a linear polysiloxane having at least one alkenyl group bonded to a silicon atom in the molecule, (B) a hydrogenpolyorganosiloxane, (C) a thermally conductive filler, and (D) a platinum catalyst, wherein the viscosity of the linear polysiloxane (A) is 100 mPa·s or less at 25 °C. The amount of substance of alkenyl groups bonded to silicon atoms relative to the entire resin composition is in the range of 8.3 to 26.0 μ mol / g, the content of the hydrogen polyorganosiloxane (B) relative to 100 parts by mass of the linear polysiloxane (A) is 1.0 to 50.0 parts by mass, the content of the thermally conductive filler (C) relative to the entire resin composition is more than 80% by volume, and the content of the platinum catalyst (D) relative to the linear polysiloxane (A) is 0.1 to 1000 ppm by mass in terms of platinum element.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a resin composition. [Background technology]

[0002] As electronic devices become more powerful, semiconductor elements are becoming increasingly dense and highly packaged. This has made it important to more efficiently dissipate heat generated by the electronic components that make up the electronic devices. For example, in semiconductor devices, heat dissipation materials are used to efficiently dissipate heat generated by electronic components. Heat dissipation materials are materials that reduce the thermal resistance of the path through which heat generated by semiconductor elements is released to a heat sink or housing, and are used in a variety of forms, including sheets, gels, and greases. A typical heat dissipation material is a resin composition in which heat-conductive filler such as aluminum nitride is filled into silicone, which has excellent heat resistance (see, for example, Patent Document 1).

[0003] Patent Document 1 states that resin compositions used as such heat dissipation materials are required to have a viscosity that is easy to handle when applied to electronic components and to have a certain degree of elasticity after curing to cushion the electronic components. Furthermore, when heat is required for curing, a high curing rate is desirable to avoid adverse effects such as deformation of the electronic components. It also discloses that by using a certain amount or more of a polysiloxane resin having at least one siloxane with a curable functional group at one site in the molecule, a resin composition can be provided that achieves appropriate viscosity / hardness and thermal conductivity, while also exhibiting an excellent curing rate and excellent handleability. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2018 / 221662 Summary of the Invention [Problem to be solved by the invention]

[0005] Resin compositions used as heat dissipation materials are required to have good dischargeability for easy handling when applied to electronic components, and high thermal conductivity. Furthermore, with the recent increase in the size of semiconductors, warping of semiconductor substrates during heat treatment during manufacturing has become an issue, and to prevent this, resin compositions that can be rapidly cured at room temperature are required. The resin composition of Patent Document 1 has good thermal conductivity and good handleability when applied to electronic components, but rapid room-temperature curing is difficult, and in practice, curing must be performed under heated conditions such as 70°C, leaving room for improvement in terms of rapid room-temperature curing. Therefore, an object of the present invention is to provide a resin composition that has good dischargeability and high thermal conductivity, and that allows rapid room temperature curing. [Means for solving the problem]

[0006] To solve the above-mentioned problems, the present inventors conducted extensive research. To improve the thermal conductivity of a resin composition, it is necessary to increase the content of a thermally conductive filler, but doing so reduces the ejection properties of the resin composition. Therefore, to achieve good ejection properties, a low-viscosity polysiloxane must be used. However, when a low-viscosity polysiloxane is used, the resin composition typically contains a large amount of alkenyl groups, which requires a long time for the curing reaction to complete, making rapid room-temperature curing difficult. In response to this problem, the present inventors discovered that by adjusting the amount of alkenyl groups bonded to silicon atoms relative to the total resin composition, a composition can be obtained that has good ejection properties, high thermal conductivity, and is capable of rapid room-temperature curing. This discovery led to the completion of the present invention.

[0007] That is, the present invention provides a resin composition comprising (A) a linear polysiloxane having one or more silicon-bonded alkenyl groups in the molecule, (B) a hydrogen polyorganosiloxane, (C) a thermally conductive filler, and (D) a platinum catalyst, wherein the viscosity of the linear polysiloxane having one or more silicon-bonded alkenyl groups in the molecule (A) is 100 mPa·s or less at 25°C, and the amount of silicon-bonded alkenyl groups in the resin composition as a whole is in the range of 8.3 to 26.0 μmol / g. The resin composition is characterized in that the content of the (B) hydrogen polyorganosiloxane is 1.0 to 50.0 parts by mass per 100 parts by mass of the (A) linear polysiloxane having one or more alkenyl groups bonded to a silicon atom in its molecule, the content of the (C) thermally conductive filler is greater than 80% by volume of the entire resin composition, and the content of the (D) platinum catalyst is 0.1 to 1000 ppm by mass relative to the (A) linear polysiloxane having one or more alkenyl groups bonded to a silicon atom in its molecule. The (A) linear polysiloxane having one or more alkenyl groups bonded to a silicon atom in its molecule preferably contains 30% by mass or more of linear polysiloxanes having one alkenyl group in its molecule. Furthermore, the ratio (MH / MA) of the moiety of hydrogen atoms directly bonded to silicon atoms (MH) to the moiety of alkenyl groups directly bonded to silicon atoms (MA) is preferably 0.7 to 3.0.

[0008] Another aspect of the present invention is a cured product of the resin composition, and an electronic part including the cured product. [Effects of the Invention]

[0009] The present invention provides a resin composition that maintains coatability, is easy to handle, and allows rapid room-temperature curing, even when a high thermal conductive filler is added to impart high thermal conductivity. This allows a resin composition with high thermal conductivity to be cured under mild conditions, making it easier to suppress warpage of semiconductor substrates during semiconductor manufacturing. DETAILED DESCRIPTION OF THE INVENTION

[0010] An example of an embodiment of the present invention will be described in detail below. However, the present invention is not limited to the embodiment described below, and can be implemented with any modifications within the scope of the gist of the present invention.

[0011] (A) A linear polysiloxane having one or more alkenyl groups bonded to silicon atoms in the molecule. The resin composition of the present invention contains (A) a linear polysiloxane having one or more alkenyl groups bonded to silicon atoms in the molecule (hereinafter, sometimes simply referred to as "(A) linear polysiloxane").

[0012] (A) The linear polysiloxane may be, for example, a polysiloxane having an average composition formula R x j R y k SiO 〔4-(j+k)〕 / 2 Examples of polyorganosiloxanes include those represented by the following formula:

[0013] R x is an alkenyl group. The alkenyl group is preferably a group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an aryl group, a 1-butenyl group, and a 1-hexenyl group, and a vinyl group is preferred.

[0014] The number of alkenyl groups bonded to silicon atoms in one molecule of the linear polysiloxane (A) is not particularly limited as long as it is at least 1, and a plurality of alkenyl groups may be contained in one molecule. The alkenyl group may be bonded to a silicon atom at the end of the molecular chain, to a silicon atom in the middle of the molecular chain, or to both. However, from the viewpoints of curing rate and physical properties of the cured product, it is preferable that the linear polysiloxane (A) has at least one alkenyl group bonded to a silicon atom at the end of the molecular chain.

[0015] R y R is a substituted or unsubstituted monovalent hydrocarbon group. yThe number of carbon atoms is preferably 1 to 12, more preferably 1 to 10. R y Examples of R include alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, hexyl group, octyl group, decyl group, dodecyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group, cyclobutyl group; aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group; aralkyl groups such as benzyl group, phenylethyl group, phenylpropyl group; groups in which some or all of the hydrogen atoms of these are substituted with halogen atoms such as chlorine, fluorine, bromine, cyano group, etc., for example, halogenated hydrocarbon groups such as chloromethyl group, trifluoropropyl group, chlorophenyl group, bromophenyl group, dibromophenyl group, tetrachlorophenyl group, fluorophenyl group, difluorophenyl group, cyanoalkyl groups such as α-cyanoethyl group, β-cyanopropyl group, γ-cyanopropyl group. Among these, alkyl groups and aryl groups are preferable, and methyl group, butyl group, and phenyl group are more preferable.

[0016] j and k are positive numbers satisfying 0 < j < 3, 0 < k < 3, 1 < j + k < 3, preferably 0.0005 ≦ j ≦ 1, 1.5 ≦ k < 2.4, 1.5 < j + k < 2.5, and more preferably numbers satisfying 0.001 ≦ j ≦ 0.5, 1.8 ≦ k ≦ 2.1, 1.8 < j + k ≦ 2.2.

[0017] (A) The viscosity of the linear polysiloxane at 25°C is 100 mPa·s or less, preferably 50 mPa·s or less, and more preferably 30 mPa·s or less in order to achieve both an appropriate viscosity and high thermal conductivity in the resin composition. The lower limit of the viscosity is not particularly limited, but for example, it can be 0.01 mPa·s or more, particularly 0.1 mPa·s or more. The viscosity in the present invention is measured using a rheometer (Discovery HR-20 manufactured by TA Instruments). Specifically, a cone plate with a diameter of 40 mm and a cone angle of 2.0° is used, and the strain rate is set to 100 s under the condition of maintaining the temperature at 25°C using a Peltier plate and a strain rate of 6000 μm / s. -1The viscosity was measured until it reached a steady state value, which was taken as the viscosity to be measured.

[0018] The content of the linear polysiloxane (A) in the resin composition of the present invention is such that the amount of silicon-bonded alkenyl groups in the resin composition as a whole is 8.3 to 26.0 μmol / g. To increase the filler loading rate in the resin composition as a whole and thereby improve thermal conductivity, it is important to reduce the viscosity of the resin. The loading rate can be increased by shortening the molecular chain length. However, as the viscosity of the polysiloxane is generally reduced, the amount of alkenyl groups in the resin composition as a whole increases, resulting in excess alkenyl groups in the resin composition as a whole, making rapid curing at room temperature difficult. In contrast, in the present invention, by limiting the amount of alkenyl groups in the resin composition as a whole to 8.3 to 26.0 μmol / g, rapid room-temperature curing can be achieved while maintaining a high filler loading rate.

[0019] The amount of silicon-bonded alkenyl groups in the entire resin composition is preferably 9.0 to 22.0 μmol / g, and more preferably 10.0 to 20.0 μmol / g.

[0020] The linear polysiloxane (A) of the present invention may be used alone or in combination with two or more types. However, it is preferable that the linear polysiloxane (A) contains at least 30% by mass, more preferably 40% by mass or more, and even more preferably 80% by mass or more of a linear polysiloxane having one alkenyl group per molecule relative to the total amount of the linear polysiloxane (A). By including a linear polysiloxane having one alkenyl group per molecule, it is easy to adjust the amount of silicon-bonded alkenyl groups in the entire resin composition to within the above range. There is no particular upper limit, and the entire amount of the linear polysiloxane (A) may be a linear polysiloxane having one alkenyl group per molecule.

[0021] (B) Hydrogen polyorganosiloxane The resin composition of the present invention contains (B) hydrogen polyorganosiloxane. (B) Hydrogen polyorganosiloxane is a polyorganosiloxane having a hydrosilyl group (Si-H group) in the molecule, and known ones can be used without particular limitation.

[0022] (B) Examples of the hydrogen polyorganosiloxane include, for example, a polyorganosiloxane represented by the average composition formula R z a H b SiO [4-(a+b)] / 2 One kind alone may be used, or two or more kinds may be used in combination.

[0023] R z is a substituted or unsubstituted monovalent hydrocarbon group that does not contain an aliphatic unsaturated bond. Examples of R z include, for example, alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, hexyl group, cyclohexyl group, octyl group; aryl groups such as phenyl group, tolyl group; aralkyl groups such as benzyl group, phenylethyl group; groups in which some or all of the hydrogen atoms of these groups are substituted with halogen atoms such as fluorine, chlorine, bromine or cyano group, for example, chloromethyl group, bromoethyl group, trifluoropropyl group, cyanoethyl group. Among these, from the viewpoints of ease of synthesis and cost, an alkyl group is preferred, and a methyl group or a butyl group is more preferred.

[0024] a and b are numbers that satisfy 0.5 ≦ a ≦ 2, 0 < b ≦ 2, and 0.5 < a + b ≦ 3, and preferably numbers that satisfy 0.6 ≦ a ≦ 1.9, 0.01 ≦ b ≦ 1.0, and 0.6 < a + b ≦ 2.8. (B) Hydrogen polyorganosiloxane preferably has an average of 2 or more hydrosilyl groups in one molecule.

[0025] The blending amount of (B) hydrogen polyorganosiloxane is 1.0 to 50.0 parts by mass, preferably 8.0 to 40.0 parts by mass, and more preferably 10.0 to 20.0 parts by mass, per 100 parts by mass of (A) linear polysiloxane, thereby enabling rapid room temperature curing.

[0026] The content of (B) hydrogen polyorganosiloxane is preferably adjusted so that the ratio (MH / MA) of the molar amount of hydrogen atoms directly bonded to silicon atoms (molar amount of hydrosilyl groups: MH) to the molar amount of alkenyl groups directly bonded to silicon atoms (MA) in the resin composition is in the range of 0.7 to 3.0. By setting the MH / MA ratio in this range, the resin composition can retain a certain degree of elasticity after curing, making it easier to cushion electronic components. MH / MA is more preferably 0.7 to 2.0, and even more preferably 0.7 to 1.0.

[0027] (C) Thermally conductive filler (C) As the thermally conductive filler, known materials can be used, such as aluminum oxide (alumina), magnesium oxide, zinc oxide, boron nitride, aluminum nitride, silica, silicon carbide, metal powder, diamond, aluminum hydroxide, and carbon. Alumina, zinc oxide, aluminum nitride, boron nitride, or silicon carbide is preferred, and alumina and aluminum nitride are particularly preferred. As these thermally conductive fillers, commercially available products can be used without any particular restrictions. Furthermore, a combination of multiple types of thermally conductive fillers, which are different chemical species, can also be used.

[0028] The thermally conductive filler is preferably an aluminum nitride thermally conductive filler. An aluminum nitride thermally conductive filler is one in which the proportion of aluminum nitride in the total amount of thermally conductive filler is 40% by volume or more. Aluminum nitride has high thermal conductivity, making it easy to obtain a resin composition with high thermal conductivity. The proportion of aluminum nitride in the total amount of thermally conductive filler is preferably 50% by volume or more, and more preferably 60% by volume or more.

[0029] The thermally conductive filler preferably includes fillers having an average particle size of 0.08 μm or more and less than 0.8 μm, fillers having an average particle size of 0.8 μm or more and less than 2.0 μm, fillers having an average particle size of 2.0 μm or more and less than 50 μm, and fillers having an average particle size of 50 μm or more and less than 300 μm. By including fillers with such different particle sizes, a structure close to a close-packed structure can be easily obtained when the fillers are efficiently filled into the resin, and high thermal conductivity and high dischargeability can be easily obtained.

[0030] The blending ratio of the filler having an average particle size of 0.08 μm or more and less than 0.8 μm is preferably 3 to 15 vol%, and more preferably 4 to 13 vol%, based on the total filler. The blending ratio of the filler having an average particle size of 0.8 μm or more and less than 2.0 μm is preferably 3 to 30 vol%, and more preferably 5 to 28 vol%, based on the total filler. The blending ratio of the filler having an average particle size of 2.0 μm or more and less than 50 μm is preferably 15 to 70 vol%, and more preferably 20 to 60 vol%. The blending ratio of the filler having an average particle size of 50 μm or more and less than 300 μm is preferably 10 to 64 vol%, and more preferably 15 to 56 vol%.

[0031] The average particle size in the present invention is the particle size at which the cumulative 50% is reached in the volume-based particle size distribution measured using a laser diffraction particle size distribution analyzer (MICROTRAC-MT3300EXII manufactured by Microtrac-Bell Corporation) after dispersing a thermally conductive filler in a solution of 5% aqueous sodium pyrophosphate solution in 90 ml of water and dispersing the resulting solution using a homogenizer.

[0032] The shape of the thermally conductive filler is not particularly limited, and for example, any of spherical, rounded, and irregularly shaped particles can be used, and at least two of these can also be used in combination.

[0033] The content of the thermally conductive filler in the resin composition of the present invention is greater than 80% by volume relative to the total volume of the resin composition. This increases the thermal conductivity of the resin composition. The content of the (C) thermally conductive filler is preferably 85% by volume or more and 92% by volume or less in terms of the balance between thermal conductivity and operability.

[0034] The thermally conductive filler (C) may be surface-treated as needed to improve compatibility with the resin, water resistance, etc. Known methods can be used for the surface treatment. For example, surface treatment can be performed using organosilicon compounds such as silicone oil, silylating agents, and silane coupling agents; acids such as phosphoric acid, phosphates, and fatty acids; polymeric compounds such as polyamide resins; and inorganic substances such as alumina and silica. Surface treatment with a silane coupling agent is particularly preferred, as it can efficiently improve affinity with the resin. As the silane coupling agent, dimethylpolysiloxane in which one molecular chain end is blocked with an alkoxysilyl group, particularly a compound represented by the following chemical formula (1), is preferred.

[0035] [ka]

[0036] (In chemical formula (1), R 31 is -O- or -CH2CH2-. R 32 R is independently an unsubstituted or substituted monovalent hydrocarbon group, preferably an alkyl group or an aryl group, more preferably a methyl group or a phenyl group. 33are independently an alkyl group having 1 to 6 carbon atoms, preferably a methyl group, an ethyl group, a propyl group, a butyl group, or a hexyl group; g is an integer of 5 to 100, preferably an integer of 5 to 70, and particularly preferably an integer of 10 to 50; and p is an integer of 1 to 3, preferably 2 or 3. The silane coupling agent also includes compounds in which one or more methyl groups in the chemical formula (1) are substituted with monovalent hydrocarbon groups other than methyl groups. Examples of the substituent include groups having 1 to 10 carbon atoms, and specific examples thereof include alkyl groups such as ethyl, propyl, butyl, hexyl, and octyl; cycloalkyl groups such as cyclopentyl and cyclohexyl; aryl groups such as phenyl and tolyl; aralkyl groups such as 2-phenylethyl and 2-methyl-2-phenylethyl; and halogenated hydrocarbon groups such as 3,3,3-trifluoropropyl, 2-(nonafluorobutyl)ethyl, 2-(heptadecafluorooctyl)ethyl, and p-chlorophenyl. When preparing a thermally conductive filler by mixing multiple powders, the surface treatment may be performed after mixing, or the powders may be mixed after surface treatment. When mixing after surface treatment, powders that have been subjected to different surface treatments may be mixed, or a surface-treated powder may be mixed with a powder that has not been surface-treated.

[0037] (D) Platinum catalyst The resin composition of the present invention contains a platinum catalyst, which promotes the addition reaction between the alkenyl groups in the linear polysiloxane (A) and the hydrosilyl groups in the hydrogen polyorganosiloxane (B), thereby enabling the resin composition to be properly cured.

[0038] As the (D) platinum catalyst, any known platinum-based catalyst can be used without limitation, and examples thereof include platinum black, platinic chloride, chloroplatinic acid, reaction products of chloroplatinic acid with monohydric alcohols, complexes of chloroplatinic acid with olefins or vinylsiloxanes, and platinum bisacetoacetate. One or more (D) platinum catalysts may be used.

[0039] The amount of the platinum catalyst (D) added is 0.1 to 1000 ppm by mass in terms of platinum element relative to the linear polysiloxane (A).

[0040] Depending on the application, a reaction inhibitor may be added to suppress the activity of the catalyst and adjust the reaction rate. Known reaction inhibitors for platinum-based catalysts include acetylene alcohols such as 2-methyl-3-butyn-2-ol and 1-ethynyl-2-cyclohexanol, and diallyl maleate.

[0041] The amount of the reaction inhibitor is preferably 1 to 20 times, and more preferably 5 to 17 times, the amount of the platinum catalyst (D). By adjusting the amount of the reaction inhibitor relative to the amount of the platinum catalyst (D), the curing reaction can be appropriately delayed. This allows for good operability to be maintained when applying the composition to electronic components.

[0042] [Other ingredients] In addition to the above, the resin composition of the present invention may contain additives such as a surface treatment agent, a plasticizer, a vulcanizing agent, a colorant, and a mold release agent, as needed. For example, by adding a surface treatment agent to the resin composition, the affinity between the thermally conductive filler (C) and the resin can be efficiently improved, as in the case where the thermally conductive filler (C) is surface-treated. In this case, the amount of the surface treatment agent is preferably 5 to 50 parts by mass, and more preferably 10 to 45 parts by mass, per 100 parts by mass of the linear polysiloxane (A). Specific examples of the surface treatment agent include the silane coupling agents described above.

[0043] [Physical properties of resin composition] The resin composition of the present invention preferably has a thermal conductivity measured by the hot disk method of 10 W / m K or more, preferably 15 W / m K or more, and more preferably 18 W / m K or more. This allows the resin composition to have high heat dissipation performance when used as a heat dissipation component, making it easier to efficiently cool heat-generating parts of electronic devices.

[0044] The resin composition of the present invention preferably has a dischargeability of 10 g / min or more when filled into a syringe with an inner diameter of a 2 mm tip discharge part and discharged at a discharge pressure of 0.62 MPa. This characteristic makes it easy to handle when applied to electronic components, improving manufacturing efficiency. The dischargeability is preferably 15.0 g / min or more, and more preferably 30.0 g / min or more. If the dischargeability is too high, it may be difficult to control the dischargeability during manufacturing, so it is preferably 500.0 g / min or less.

[0045] The thickness of the resin composition (hereinafter sometimes referred to as "BLT") measured after sandwiching 0.02 mL of the resin composition between two 10 mm x 10 mm silicon chips and applying a force of 50 N for 60 seconds is preferably 300 μm or less, more preferably 250 μm or less, and even more preferably 200 μm or less. This characteristic allows the resin composition to be easily formed into a thin film, which can be easily formed into a thin film during the manufacture of electronic components. This makes it easy to apply the resin composition in a thin film form to electronic components to reduce thermal resistance and to increase manufacturing efficiency when applying the resin composition in a thin film form during the manufacture of electronic components.

[0046] [Room temperature curability] When the Type E hardness of the resin composition of the present invention after standing at 25°C for 24 hours is defined as E1 and the Type E hardness after further heating at 150°C for 2 hours is defined as E2, it is preferable that the difference between E2 and E1, (E2-E1), is less than 10.

[0047] In the resin composition of the present invention, the Type E hardness increases as the curing reaction between (A) a linear polysiloxane and (B) a hydrogen polyorganosiloxane progresses, and the increase in Type E hardness stops when the curing reaction is complete. The curing reaction can be accelerated by heating. Therefore, if the curing reaction is not complete at 25°C, subsequent heating at 150°C will increase the Type E hardness and increase the (E2 - E1) value. On the other hand, if rapid room-temperature curing is possible at room temperature, the increase in Type E hardness will be small even if the composition is cured at 25°C and then heated. In the present invention, a ratio of (E2 - E1) less than 10 is considered to indicate rapid curing at 25°C (room temperature). From the perspective of achieving more rapid room-temperature curing, a ratio of (E2 - E1) of 5 or less is preferred. By reducing (E2 - E1), the curing reaction is slowed down during use of electronic components, making it easier to prevent peeling and deformation.

[0048] Furthermore, E1 and E2 are not particularly limited, but are preferably 10 or more and 70 or less, and more preferably 30 or more and 60 or less. When Type E is small and the flexibility of the cured resin composition is high, the resin composition can better conform to the heat-generating body and exhibit heat dissipation performance more efficiently.

[0049] [Method of producing resin composition] The method for producing the resin composition of the present invention is not particularly limited, and it can be produced by mixing the resin, filler, and other components as needed using a known method using a blender, mixer, or the like. During the mixing, the components may be added simultaneously to a mixer or the like and mixed, or the components may be added sequentially to a mixer or the like and mixed. The order of addition is not particularly limited. Furthermore, if necessary, treatment by heating, decompression, or other known methods may be performed.

[0050] [Form of resin composition] The resin composition of the present invention may be a one-component type or a two-component type comprising a first and a second component. A two-component type resin composition is obtained by mixing the first and second components when used. In the case of a two-component type, the resin composition is cured after mixing, so it is important that the requirements of the present invention are met after mixing. The composition of the resin composition after mixing can be calculated from the composition of the first component, the composition of the second component, and the mixed amounts of the first and second components. In a two-component resin composition, the mass ratio of the first and second components (first component / second component) when mixed is not limited, but is preferably 1.0 or a value close to 1.0, for example, preferably 0.8 to 1.2, more preferably 0.9 to 1.1, and even more preferably 0.95 to 1.05. By setting the mass ratio of the first and second components when mixed to 1.0 or a value close to 1.0, the resin composition can be easily prepared.

[0051] In the case of a two-component resin composition, the method for mixing the first and second components to obtain the resin composition is not limited, and for example, a static mixer, a mixer with stirring blades, a vibration mixer, a planetary mixer, etc. can be used. As with a one-component resin composition, the first and second components can be produced by mixing the respective components using a known method using a blender, mixer, etc.

[0052] In a two-component resin composition, the first component preferably contains (A) a linear polysiloxane and (D) a platinum catalyst but does not contain (B) a hydrogen polyorganosiloxane, and the second component preferably contains (B) a hydrogen polyorganosiloxane but does not contain (D) a platinum catalyst. While the entire (A) linear polysiloxane constituting the resin composition may be contained in the first component, it is preferable that a portion of the (A) linear polysiloxane be contained in the first component and the remainder be contained in the second component. By dividing the (A) linear polysiloxane into the first and second components, it becomes easier to adjust the dischargeability of the first and second components to a desired range and to achieve a mass ratio of the first component to the second component of 1.0 or close to 1.0. It is preferable that the entire (B) hydrogen polyorganosiloxane constituting the resin composition be contained in the second component and not in the first component. Such a first component contains a (D) platinum catalyst that accelerates the curing reaction, but does not contain a (B) hydrogen polyorganosiloxane, thereby preventing the curing reaction from proceeding before mixing with the second component. The second component contains a (B) hydrogen polyorganosiloxane, but does not contain a (D) platinum catalyst that accelerates the curing reaction, thereby preventing the curing reaction from proceeding before mixing with the first component. The second component also contains a (B) hydrogen polyorganosiloxane, but does not contain a (D) platinum catalyst, so even if it contains a (A) linear polysiloxane, the curing reaction can be substantially prevented from proceeding during storage, etc. The second component may also contain a reaction inhibitor to further prevent the reaction from proceeding.

[0053] At least one of the first and second parts contains the thermally conductive filler (C), and it is more preferable that both the first and second parts contain the thermally conductive filler (C).

[0054] When the (C) thermally conductive filler is contained in both the first and second parts, it is more preferable that it be contained approximately equally in the first and second parts. Specifically, the ratio (mass ratio) of the content of the (C) thermally conductive filler in the second part to the content of the (C) thermally conductive filler in the first part is preferably 0.67 to 1.5, more preferably 0.83 to 1.2, and even more preferably 0.91 to 1.1. By distributing the (C) thermally conductive filler approximately equally in the first and second parts, it becomes easier to reduce the difference in ejection properties between the first and second parts and also makes it easier to bring the mass ratio of the first and second parts when mixed closer to 1.0.

[0055] [Method for curing resin composition] The resin composition of the present invention can be cured by a hydrosilylation reaction between (A) a linear polysiloxane and (B) a hydrogen polyorganosiloxane to form a cured product. The shape of the cured product is not limited, and it can be molded into a sheet or other shape to match the shape of an electronic component. Furthermore, when applying the composition to an electronic component, it can be applied directly to a heat generating element and cured under pressure, allowing it to be molded in a state that conforms to the heat generating element, thereby achieving more efficient heat dissipation performance.

[0056] The curing temperature is not particularly limited, but is preferably room temperature, for example, 5°C to 35°C, particularly 15°C to 30°C, since this allows the effects of the present invention to be particularly well-developed. When the resin composition is a one-component type, it is preferably stored under low-temperature conditions, such as refrigeration or freezing, to prevent hardening before use, and then stored at room temperature or the hardening temperature before hardening, and thawed. In this case, it is preferable to apply the composition to an electronic component and harden it within 6 hours. When using a two-component resin composition, it is preferable to mix the two components immediately before hardening, apply the composition to an electronic component, and harden it.

[0057] [Uses of resin composition] The resin composition can be used as a heat dissipation component (heat dissipation material) for efficiently dissipating heat generated by electronic components mounted in home appliances, automobiles, personal computers, etc., and specific examples thereof include heat dissipation sheets, heat dissipation greases, heat dissipation gels, adhesives, semiconductor encapsulants, and underfills.

[0058] When the resin composition of the present invention is used as a heat dissipation member, the heat generated by an electronic component can be efficiently dissipated by using the resin composition of the present invention between a substrate having a heat-generating portion such as a semiconductor element and a substrate having a cooling portion such as a heat sink or a housing. Specifically, the electronic component includes a heat dissipation member containing the resin composition of the present invention, a substrate having a heat-generating portion, and a substrate having a cooling portion, and the heat dissipation member is arranged so as to be in contact with the substrate having the heat-generating portion, and particularly the electronic component is arranged so as to be in contact with both the substrate having the heat-generating portion and the substrate having the cooling portion. [Example]

[0059] Examples of the present invention will be described below, but the scope of the present invention is not limited to these examples. Materials used in the examples and comparative examples are as follows.

[0060] [(A) Linear polysiloxane having one or more alkenyl groups bonded to silicon atoms within the molecule] (A linear polysiloxane having one alkenyl group bonded to a silicon atom in the molecule) SiMV1: A compound represented by the following chemical formula (2) having a viscosity of 30 mPa·s at 25°C. This compound has the average composition formula R x j R y k SiO 〔4-(j+k)〕 / 2 In R x is a vinyl group, R y is a methyl group, j=0.032, k=2.032.

[0061] [ka]

[0062] (A linear polysiloxane with two alkenyl groups bonded to silicon atoms within the molecule) SiDV1: A compound represented by the following chemical formula (3) having a viscosity of 3 mPa·s at 25°C. Note that this compound has n=10 and an average composition formula R x j R y k SiO 〔4-(j+k)〕 / 2 In R x is a vinyl group, R y is a methyl group, j=0.067, k=2.000. SiDV2: A compound represented by the following chemical formula (3) having a viscosity of 100 mPa·s at 25°C. Note that this compound has n=64 and an average composition formula R x j R y k SiO 〔4-(j+k)〕 / 2 In R x is a vinyl group, R y is a methyl group, j=0.030, k=2.000.

[0063] [ka]

[0064] [(B) Hydrogen polyorganosiloxane] CL1: Methylhydrogenpolysiloxane A compound represented by the following chemical formula (4). This compound has the average composition formula R z a H b SiO [4-(a+b)] / 2 In R z is a methyl group, a=1.75, b=0.28.

[0065] [ka]

[0066] [(C) Thermally conductive filler] AO1: Aluminum oxide filler (average particle size 0.2 μm, manufactured by Sumitomo Chemical Co., Ltd.) AL1: Aluminum nitride filler (average particle size 1 μm, manufactured by Tokuyama Corporation) AL2: Aluminum nitride filler (average particle size 20 μm, manufactured by Tokuyama Corporation) AL3: Aluminum nitride filler (average particle size 120 μm, manufactured by Tokuyama Corporation) [(D) Platinum catalyst] ·Pt-DVi4 complex (solution of platinum complex with 1,3-divinyltetramethyldisiloxane) [others] Silane coupling agent: Dimethylpolysiloxane with one end of the molecular chain blocked with an alkoxysilyl group Reaction inhibitor: 1-ethynyl-1-cyclohexanol

[0067] <Evaluation of ejection properties> The amount of extrusion per minute (g / min) at 25°C was measured using a syringe "PSY-30F" manufactured by Musashi Engineering Co., Ltd. The inner diameter of the syringe body where the sample was stored was 22 mm, and the inner diameter of the tip where the sample was extruded was 2 mm. The extrusion pressure was 0.62 MPa. In the case of one-component resin compositions, the syringe was filled within one hour after production, and the extrusion properties were evaluated. In the case of two-component resin compositions, the two components were mixed at a mass ratio of 1:1, and then the syringe was filled within one hour, and the extrusion properties were evaluated.

[0068] <Evaluation of room temperature curing properties> The resin composition was poured into an aluminum mold with inner dimensions of 6 mm (depth) × 60 mm (length) × 30 mm (width) and cured in a thermostatic chamber at 25°C for 24 hours. The cured product was removed from the thermostatic chamber and then removed from the mold. The Type E hardness was measured in accordance with JIS K 6249, and the hardness was determined to be E1. After further heating at 150°C for 2 hours, the hardness was measured again, and the hardness was determined to be E2. E2-E1 was calculated from the obtained hardnesses E1 and E2. If (E2-E1) was less than 10, the curing reaction was deemed to be nearly complete within 24 hours at 25°C, indicating that rapid room-temperature curing was possible. In the case of one-component resin compositions, evaluation was performed by immediately pouring the compositions into a mold after production, while in the case of two-component resin compositions, evaluation was performed by immediately pouring the compositions into a mold after mixing the two components at a mass ratio of 1:1.

[0069] <Measurement of thermal conductivity> The resin composition was poured into an aluminum mold with inner dimensions of 6 mm (depth) × 60 mm (length) × 30 mm (width) and cured in a thermostatic chamber at 25°C for 24 hours to obtain two measurement samples. The thermal conductivity was measured by sandwiching the sensor of a thermal conductivity meter (TPS500, manufactured by Kyoto Electronics Manufacturing Co., Ltd.) between the measurement samples.

[0070] Example 1 A resin composition was prepared by mixing 100 parts by weight of SiMV1, 11.0 parts by weight of CL1, 274 parts by weight of AO1, 611 parts by weight of AL1, 949 parts by weight of AL2, and 2084 parts by weight of AL3 with 4.0 parts by weight of a platinum catalyst (Pt-DVi4 complex) (496 ppm by weight of platinum element relative to the (A) linear polysiloxane), 45 parts by weight of a silane coupling agent (dimethylpolysiloxane with one end of the molecular chain capped with an alkoxysilyl group) relative to the SiMV1, and 1-ethynyl-1-cyclohexanol (15 times the amount of the platinum catalyst) as a reaction inhibitor. The resulting resin composition was evaluated for thermal conductivity, dischargeability, E1, and E2. The composition of the resin composition and the evaluation results of the resulting resin composition are shown in Table 1.

[0071] (Examples 2 to 7, Comparative Examples 1 to 3) Resin compositions were obtained and evaluated in the same manner as in Example 1, except that the compositions of the resin components and thermally conductive filler were changed as shown in Tables 1 and 2. The compositions of the resin components and thermally conductive filler, and the evaluation results of the obtained resin compositions are shown in Tables 1 and 2.

[0072] Example 8 A first part and a second part were prepared as a two-component resin composition and mixed in a mass ratio of 1:1 to obtain a resin composition having the composition shown in Table 1. The first part was prepared by mixing 100 parts by mass of SiMV1, 289 parts by mass of AO1, 645 parts by mass of AL1, 1003 parts by mass of AL2, 2246 parts by mass of AL3, 8.2 parts by mass of a platinum catalyst (Pt-DVi4 complex) as a catalyst, and 48 parts by mass of dimethylpolysiloxane, one end of the molecular chain of which is capped with an alkoxysilyl group, as a silane coupling agent, relative to the SiMV1, using a blade stirrer. The second part was prepared by mixing 100 parts by weight of SiMV1, 21.2 parts by weight of CL1, 339 parts by weight of AO1, 758 parts by weight of AL1, 1177 parts by weight of AL2, 2638 parts by weight of AL3, 48 parts by weight of dimethylpolysiloxane terminated at one end of the molecular chain with an alkoxysilyl group as a silane coupling agent relative to the SiMV1, and 1-ethynyl-1-cyclohexanol as a reaction inhibitor in a 15-fold amount relative to the amount of the platinum-based catalyst, using a blade-type mixer. The thermal conductivity, dischargeability, E1, and E2 of the resulting resin composition were evaluated. The composition of the resin composition and the evaluation results of the resulting resin composition are shown in Table 1.

[0073] [Table 1]

[0074] [Table 2]

[0075] The resin compositions of Examples 1 to 8 had high thermal conductivity and good dischargeability, even though the content of the thermally conductive filler was 80% by mass or more and the thermal conductivity was 10 W / m K or more by limiting the viscosity of the linear polysiloxane to 100 mPa·s or less. The resin compositions had high thermal conductivity and good dischargeability, with a discharge rate of 15.0 g / min or more. Furthermore, when the amount of silicon-bonded alkenyl groups relative to the total resin composition was 8.3 to 26.0 μmol / g and the content of (B) hydrogen polyorganosiloxane was 1.0 to 50.0 parts by mass per 100 parts by mass of (A) linear polysiloxane, the curing reaction was nearly complete after 24 hours of curing at 25°C, allowing for rapid room-temperature curing. In contrast, in Comparative Examples 1 and 3, the amount of silicon-bonded alkenyl groups relative to the total resin composition exceeded 26.0 μmol / g, and the curing reaction was not complete after 24 hours of curing at 25°C, preventing rapid room-temperature curing. Furthermore, rapid room-temperature curing was also not possible in Comparative Example 2. This is presumably because the content of the (B) hydrogen polyorganosiloxane component corresponding to the (A) linear polysiloxane was greater than 50.0 parts by mass, and unreacted hydrogen organosiloxane remained in the resin composition after completion of the hydrosilylation reaction, and subsequent heating caused a condensation reaction between the unreacted hydrosilyl groups.

Claims

1. A resin composition comprising: (A) a linear polysiloxane having one or more alkenyl groups bonded to silicon atoms in the molecule; (B) a hydrogen polyorganosiloxane; (C) a thermally conductive filler; and (D) a platinum catalyst; the viscosity of the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule is 100 mPa s or less at 25°C; the amount of silicon-bonded alkenyl groups relative to the total amount of the resin composition is in the range of 8.3 to 26.0 μmol / g; the content of the hydrogen polyorganosiloxane (B) is 1.0 to 50.0 parts by mass relative to 100 parts by mass of the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule, the content of the thermally conductive filler (C) relative to the entire resin composition is greater than 80% by volume, the content of the platinum catalyst (D) relative to the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule is 0.1 to 1000 ppm by mass in terms of platinum element; Resin composition.

2. 2. The resin composition according to claim 1, wherein the linear polysiloxane (A) having one or more alkenyl groups bonded to silicon atoms in the molecule contains 30% by mass or more of a linear polysiloxane having one alkenyl group in the molecule.

3. 2. The composition according to claim 1, wherein the ratio of the amount of substance of hydrogen atoms directly bonded to silicon atoms (MH) to the amount of substance of alkenyl groups directly bonded to silicon atoms (MA) (MH / MA ratio) is in the range of 0.7 to 3.

0.

4. A cured product of the resin composition according to any one of claims 1 to 3.

5. An electronic part comprising the cured product according to claim 4.

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