Heat-resistant resin composition, heat-resistant resin sheet using same, and method for producing same

Abstract

Provided are a heat-resistant resin composition which does not inhibit the curing of a thermosetting resin and does not adversely affect semiconductors, etc.; a heat-resistant resin sheet using the same; and a method for producing the same. The heat-resistant resin composition contains a matrix resin made of a thermosetting resin and a heat-resistant auxiliary, and the heat-resistant auxiliary is a cellulose charcoal powder.

Description

[Technical field]

[0001] The present invention relates to a heat-resistant resin composition suitable for being interposed between a heat-generating portion of an electric or electronic component and a heat sink, a heat-resistant resin sheet using the same, and a method for producing the same. [Background technology]

[0002] In recent years, the performance of semiconductors such as CPUs has improved remarkably, and the amount of heat generated has also increased. For this reason, heat sinks are attached to electronic components that generate heat, and thermally conductive sheets are used to improve the adhesion between the semiconductor and the heat sink. As devices become smaller, more powerful, and more highly integrated, heat-conductive sheets are required to have heat resistance, while pigments are added to differentiate them from other companies' products or between products. WO2019-021826 proposes adding iron oxide or the like to a silicone composition to improve heat resistance. In JP 2018-123200 A, the applicant has proposed carbon powders such as acetylene black, carbon nanotubes, carbon nanofibers, graphene, and furnace black as heat resistance improvers. Summary of the Invention

[0003] The present invention relates to a heat-resistant resin composition comprising a matrix resin made of a thermosetting resin and a heat-resistant auxiliary, wherein the heat-resistant auxiliary is a cellulose charcoal powder. [Brief description of the drawings]

[0004] [Figure 1] FIG. 1 is a schematic cross-sectional view showing a method of using a heat-resistant resin sheet according to one embodiment of the present invention. [Diagram 2] 2A-B are schematic explanatory views showing a method for measuring the thermal conductivity of a sample in one embodiment of the present invention. [Diagram 3] FIG. 3 is an enlarged SEM photograph (magnification 1000 times) of the bamboo charcoal powder used in one embodiment of the present invention. [Figure 4]FIG. 4 is a graph showing the change over time in ASKER-C hardness when the heat-resistant resin sheets of the examples of the present invention and the comparative examples are stored in a thermostatic chamber at 150° C. for up to 1000 hours. [Diagram 5] FIG. 5 is a graph showing the change over time in viscosity of heat-resistant resin compositions of the examples of the present invention and the comparative examples. Detailed Description of the Invention

[0005] However, conventional resin compositions and pigments added to resin sheets using the same often contain metals or ion components such as sulfur, copper, cobalt, etc. If these metals or ion components are contained, the curing of the thermosetting resin may be inhibited, and resin sheets containing such metals or components also have a problem of adversely affecting semiconductors and the like.

[0006] In order to solve the above-mentioned problems of the conventional art, the present invention provides a heat-resistant resin composition that does not inhibit the curing of a thermosetting resin and does not adversely affect semiconductors, etc., and a heat-resistant resin sheet using the same and a method for producing the same.

[0007] The heat-resistant resin composition of the present invention is a heat-resistant resin composition containing a matrix resin made of a thermosetting resin and a heat-resistant auxiliary, and is characterized in that the heat-resistant auxiliary is a cellulose charcoal powder.

[0008] The heat-resistant resin sheet of the present invention is characterized in that it contains the heat-resistant resin composition and is formed into a sheet shape.

[0009] The method for producing a heat-resistant resin sheet of the present invention is characterized by comprising the steps of vacuum degassing the heat-resistant resin composition, rolling it, forming it into a sheet, and then heat-curing it to obtain a heat-resistant resin sheet.

[0010] The heat-resistant resin composition of the present invention contains a matrix resin made of a thermosetting resin and a heat-resistant auxiliary, and the heat-resistant auxiliary is cellulose charcoal powder, so that the heat-resistant resin composition does not cause curing inhibition of the thermosetting resin and does not adversely affect semiconductors, etc., and a heat-resistant resin sheet using the same and a manufacturing method thereof can be provided. Since the cellulose charcoal powder is made by burning natural cellulose at high temperatures to make charcoal and pulverizing it, it contains almost no metal or ion components such as sulfur, copper, cobalt, etc. Therefore, even if the heat-resistant resin composition containing the cellulose charcoal powder is exposed to, for example, 150 ° C for a long time, it has heat resistance such that the hardness is not easily changed. Such a heat-resistant resin composition is useful as a thermally conductive composition and a thermally conductive sheet using the same, particularly a heat-dissipating sheet containing thermally conductive particles: TIM (Thermal Interface Material). Since the heat-dissipating sheet conducts heat from heat-generating electronic components such as semiconductors to a heat sink, it is important that it has high heat resistance.

[0011] [Heat-resistant resin composition] The heat-resistant resin composition of the present invention contains the matrix resin made of a thermosetting resin and a heat-resistant auxiliary as described above. <Matrix resin (component A)> The matrix resin made of the thermosetting resin of the present invention is, for example, a silicone resin, an acrylic resin, a fluororubber, an epoxy resin, a phenolic resin, an unsaturated polyester resin, a melamine resin, an acrylic resin, a fluororesin, a non-reactive silicone oil, etc. Among these, silicone resin and non-reactive silicone oil are preferred as the matrix resin because they have high heat resistance, are not corrosive to the surroundings, and emit less by-products outside the system. The silicone resin may be in the form of a rubber, a gel, a grease, a putty, a liquid, etc.

[0012] Silicone resin will be described as a matrix resin. As an example of the silicone resin, addition curing type silicone resin, peroxide curing type silicone resin, or condensation type silicone resin is preferable. These may be used alone or in combination. Each silicone resin will be described.

[0013] As an example, the matrix resin preferably contains the following components (A1) and (A2). (A1) Base polymer: Organopolysiloxane containing two or more alkenyl groups bonded to silicon atoms in one molecule (A2) Crosslinking component: Organohydrogenpolysiloxane containing at least two hydrogen atoms bonded to silicon atoms in one molecule.

[0014] The addition-curable silicone resin may contain an organopolysiloxane having no reactive groups other than the components (A1) and (A2), such as an unreacted silicone oil, one example of which is dimethylpolysiloxane.

[0015] Each component will be described below. <<Base polymer (A1 component)>> The base polymer is an organopolysiloxane containing two or more alkenyl groups bonded to silicon atoms in one molecule. The organopolysiloxane is the main agent (base polymer component) in the matrix resin of the present invention. This organopolysiloxane has two alkenyl groups bonded to silicon atoms in one molecule, such as vinyl groups and allyl groups, having 2 to 8 carbon atoms, particularly 2 to 6 carbon atoms. The viscosity of the organopolysiloxane is desirably 10 to 1,000,000 mPa·s, particularly 100 to 100,000 mPa·s at 25°C, from the viewpoints of workability, curability, etc.

[0016] Specifically, an organopolysiloxane containing alkenyl groups bonded to silicon atoms at both ends of the molecular chain in one molecule, as represented by the following general formula (I), can be used. This organopolysiloxane is a linear organopolysiloxane whose side chains are blocked with alkyl groups. From the viewpoints of workability, curability, etc., it is desirable for the organopolysiloxane to have a viscosity of 10 to 1,000,000 mPa·s at 25°C. Note that this linear organopolysiloxane may contain a small amount of a branched structure (trifunctional siloxane unit) in the molecular chain.

[0017] [ka]

[0018] In the formula, each R 1 may be the same or different and are unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated bonds, R 2 is an alkenyl group, k is 0 or a positive integer.

[0019] In the general formula (I), R 1 The unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond is preferably, for example, one having 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms. Specific examples of the unsubstituted monovalent hydrocarbon group having no aliphatic unsaturated bond include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl, phenylethyl, and phenylpropyl. Examples of the substituted monovalent hydrocarbon group having no aliphatic unsaturated bond include groups in which some or all of the hydrogen atoms of the unsubstituted monovalent hydrocarbon group are substituted with halogen atoms such as fluorine, bromine, and chlorine; or cyano groups, such as halogen-substituted alkyl groups such as chloromethyl, chloropropyl, bromoethyl, and trifluoropropyl; and cyanoethyl groups.

[0020] In the general formula (I), R 2 The alkenyl group preferably has, for example, 2 to 6 carbon atoms, particularly 2 to 3. Specific examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, an isopropenyl group, a butenyl group, an isobutenyl group, a hexenyl group, and a cyclohexenyl group, and is preferably a vinyl group.

[0021] In general formula (I), k is 0 or a positive integer, preferably 0 or a positive integer satisfying 0≦k≦10,000, more preferably 5≦k≦2,000, and more preferably 10≦k≦1,200.

[0022] The organopolysiloxane of component A1 may be used in combination with an organopolysiloxane having at least 3, usually 3 to 30, and preferably about 3 to 20 alkenyl groups, such as vinyl groups and allyl groups, bonded to silicon atoms having 2 to 8 carbon atoms, particularly 2 to 6 carbon atoms, in one molecule. The molecular structure of the organopolysiloxane used in combination may be any of linear, cyclic, branched, and three-dimensional network molecular structures. The organopolysiloxane used in combination is preferably a linear organopolysiloxane whose main chain is composed of repeated diorganosiloxane units, whose both molecular chain terminals are blocked with triorganosiloxy groups, and whose viscosity at 25°C is 10 to 1,000,000 mPa·s, particularly 100 to 100,000 mPa·s.

[0023] In organopolysiloxanes containing two or more alkenyl groups bonded to silicon atoms in one molecule, the alkenyl groups may be bonded to any part of the molecule. For example, they may be bonded to silicon atoms at the molecular chain terminals or non-terminals (in the middle of the molecular chain). Among them, linear organopolysiloxanes having 1 to 3 alkenyl groups on each of the silicon atoms at both molecular chain terminals, as represented by the following general formula (II), and having a viscosity of 10 to 1,000,000 mPa·s at 25°C, are preferred in terms of workability and curability. However, when the number of alkenyl groups bonded to silicon atoms at the molecular chain terminals of this linear organopolysiloxane is one or two in total at both terminals, linear organopolysiloxanes having alkenyl groups bonded to silicon atoms at non-terminals (in the middle of the molecular chain) as substituents in diorganosiloxane units are preferred. This linear organopolysiloxane may contain a small amount of a branched structure (trifunctional siloxane unit) in the molecular chain.

[0024] [ka]

[0025] In the formula, each R 3 may be the same or different and are unsubstituted or substituted monovalent hydrocarbon groups, at least one of which is an alkenyl group; Each R 4 may be the same or different and are unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated bonds, R 5 is an alkenyl group, l and m are each independently 0 or a positive integer.

[0026] In the general formula (II), R 3 The monovalent hydrocarbon group preferably has, for example, 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms. Specific examples of the unsubstituted monovalent hydrocarbon group include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, cyclohexyl, octyl, nonyl, and decyl groups; aryl groups such as phenyl, tolyl, xylyl, and naphthyl groups; aralkyl groups such as benzyl, phenylethyl, and phenylpropyl groups; and alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, and octenyl groups. Examples of the substituted monovalent hydrocarbon group include groups in which some or all of the hydrogen atoms of the unsubstituted monovalent hydrocarbon group have been substituted with halogen atoms such as fluorine, bromine, chlorine, etc.; or a cyano group, etc., such as halogen-substituted alkyl groups such as a chloromethyl group, a chloropropyl group, a bromoethyl group, or a trifluoropropyl group; and a cyanoethyl group.

[0027] In the general formula (II), R 4 As the unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond, those having 1 to 10 carbon atoms, particularly 1 to 6 carbon atoms, are preferred. 4 The unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond is preferably selected from the group consisting of the above R 1Specific examples similar to those of the unsubstituted or substituted monovalent hydrocarbon group having no aliphatic unsaturated bond can be exemplified, provided that an alkenyl group is not included.

[0028] In general formula (II), R 5 As the alkenyl group of, for example, those having 2 to 6 carbon atoms, particularly preferably those having 2 to 3 carbon atoms, specifically the same as R of the formula (I) 2 are exemplified, and preferably a vinyl group.

[0029] In general formula (II), l and m are each independently 0 or a positive integer, preferably 0 or a positive integer satisfying 0 < l + m ≦ 10,000, more preferably 5 ≦ l + m ≦ 2,000, still more preferably 10 ≦ l + m ≦ 1,200, and preferably an integer satisfying 0 < l / (l + m) ≦ 0.2, more preferably 0.0011 ≦ l / (l + m) ≦ 0.1.

[0030] <<Crosslinking component (A2 component)>> The crosslinking component of the A2 component of the present invention is, for example, an organohydrogenpolysiloxane. This organohydrogenpolysiloxane acts as a crosslinking agent. A cured product is formed by an addition reaction (hydrosilylation) between the SiH group in this organohydrogenpolysiloxane and the alkenyl group in the organopolysiloxane of the A1 component. The organohydrogenpolysiloxane can be used as a crosslinking component (A2 component) as long as it has two or more hydrogen atoms bonded to silicon atoms (i.e., SiH groups) in one molecule. The molecular structure of this organohydrogenpolysiloxane may be any of linear, cyclic, branched, or three-dimensional network structures. Further, those having about 2 to 1,000, particularly about 2 to 300, silicon atoms (i.e., degree of polymerization) in one molecule of the organohydrogenpolysiloxane can be preferably used as the crosslinking component (A2 component).

[0031] The organohydrogenpolysiloxane contains a SiH group as described above. In the organohydrogenpolysiloxane, the position of the SiH group is not particularly limited, and may be at the end of the molecular chain or at a non-end of the molecular chain (in the middle of the molecular chain). In addition, the organic group bonded to the silicon atom other than a hydrogen atom is R in the general formula (I). 1 and the like. Examples of the substituted or unsubstituted monovalent hydrocarbon groups having no aliphatic unsaturated bonds include those shown below.

[0032] An example of the organohydrogenpolysiloxane of component A2 is one represented by the following formula (III).

[0033] [ka]

[0034] During the ceremony, Each R 6 may be the same or different and are an alkyl group, a phenyl group, an epoxy group, an acryloyl group, a methacryloyl group, an alkoxy group, or a hydrogen atom, and at least two of them are hydrogen atoms. L is an integer from 0 to 1,000, preferably an integer from 0 to 300, M is an integer from 1 to 200.

[0035] The crosslinking component is preferably contained in an amount of less than 1 mole per mole of silicon-bonded alkenyl groups in the base polymer component (A1).

[0036] The non-reactive silicone oil as the matrix resin will now be described. The non-reactive silicone oil has a kinetic viscosity of, for example, 50 to 3,000 mm at 25°C. 2 / s, preferably 70 to 2,500 mm 2 / s. Viscosity is measured using a Brooklyn Field type rotational viscometer SP No.2. If the kinetic viscosity is within the above range, oil bleeding is suppressed to a low level. Furthermore, when the heat-resistant resin composition further contains thermally conductive particles, the filling property of the thermally conductive particles is also improved. The non-reactive silicone oil is a silicone polymer that does not have a reactive group, and examples of the non-reactive silicone oil include dimethylpolysiloxane and diphenylpolysiloxane.

[0037] <Heat resistance aid (Component D)> The cellulose charcoal powder of the heat resistance aid of the present invention is preferably at least one charcoal powder selected from the group consisting of bamboo charcoal powder, charcoal powder, coconut shell charcoal powder, mangrove charcoal powder, plum nut charcoal powder, plum seed charcoal powder, and rice husk charcoal powder. Among them, bamboo charcoal powder, plum nut charcoal powder, plum seed charcoal powder, or charcoal powder, which are easily available with a uniform particle size, are preferable. These cellulose charcoal powders are made from natural bamboo or wood and are fired at high temperatures. The cellulose charcoal powder can be obtained by, for example, firing at a temperature of 1000 to 1200°C, crushing the binchotan charcoal (charcoal (sumi) that is carbonized to the point that it makes a metallic sound when struck) that has been fired in a kiln, and arranging it to a predetermined particle size. Iron black (iron tetraoxide), carbon black, etc. have been used as conventional black pigments, and red iron oxide (ferric oxide) etc. have been used as red pigments, but these pigments contain metals or ion components such as sulfur, copper, and cobalt. Therefore, there was a problem of the above-mentioned inhibition of the hardening of the thermosetting resin, but since the cellulose charcoal powder used in the present invention does not contain metal or ionic components, such a problem does not occur. Furthermore, since the heat resistance auxiliary of the present invention is a cellulose charcoal powder, it also functions as a black pigment.

[0038] The heat resistance auxiliary may be surface-treated with a coupling agent. The coupling agent may be, for example, a silane coupling agent, specifically, a compound represented by the formula R(CH3) a Si(OR') 4-a(R is an unsubstituted or substituted organic group having 1 to 20 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1), or a partial hydrolyzate thereof. Examples of the silane compound include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, and octadecyltriethoxysilane. The silane compounds can be used alone or in combination of two or more. The heat resistance assistant may be surface-treated with preferably 0.1 to 50 parts by mass, more preferably 0.5 to 30 parts by mass of the silane coupling agent, based on 100 parts by mass of the heat resistance assistant, using a stirring and defoaming device. The silane coupling agent coats the surface of the heat resistance assistant (surface treatment), and as a result, the heat resistance assistant becomes more easily filled into the matrix resin (plasticizer function).

[0039] The cellulose charcoal powder has a volume-based cumulative particle size distribution D50 (median diameter) of preferably 0.01 to 150 μm, more preferably 0.05 to 130 μm, and even more preferably 0.1 to 100 μm. The cellulose charcoal powder having the above median diameter is suitable for use as a heat resistance auxiliary and a black pigment.

[0040] The cellulose charcoal powder is contained in the heat-resistant resin composition in an amount of 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, per 100 parts by mass of the matrix resin. With this content, the cellulose charcoal powder is suitable as a heat resistance auxiliary and a black pigment.

[0041] <Thermal conductive particles (component C)> The heat-resistant resin composition of the present invention preferably further contains thermally conductive particles. This is because such a heat-resistant resin composition is useful as a thermally conductive composition. The thermally conductive particles are preferably at least one inorganic particle selected from the group consisting of aluminum oxide (alumina), zinc oxide, magnesium oxide, aluminum nitride, boron nitride, aluminum hydroxide, and silicon carbide, and a combination of aluminum oxide (alumina) and aluminum hydroxide is more preferable. These inorganic particles have high thermal conductivity, and a heat-resistant resin composition containing them is suitable as a material for a heat dissipation sheet: TIM (Thermal Interface Material). The D50 (median diameter) of the cumulative particle size distribution based on volume of the thermally conductive particles is preferably 0.01 to 150 μm, more preferably 0.05 to 130 μm, and even more preferably 0.1 to 100 μm.

[0042] The thermally conductive particles can be a mixture of a plurality of types of thermally conductive inorganic particles having different average particle sizes. This is because the thermally conductive inorganic particles having a small particle size are filled between the larger particles, and the particles can be filled in a state close to close packing, and the thermal conductivity of the cured product of the heat-resistant resin composition is increased. This is because the cured product of the heat-resistant resin composition has a low plasticity and is a heat-resistant resin composition with good moldability. This is because the cured product of the heat-resistant resin composition can be molded into a heat-dissipating sheet: TIM (Thermal Interface Material), which has a low compression load and is easier to handle than putty-like materials.

[0043] For example, when the total amount of the thermally conductive particles is 100 mass %, 50 to 90% by mass of alumina with a D50 (median diameter) of less than 20 μm, It is preferable that the aluminum hydroxide has a D50 (median diameter) of 20 μm or more and contains 10 to 50 mass % of the aluminum hydroxide. 60 to 80% by mass of alumina with a D50 (median diameter) of less than 20 μm, It is more preferable that the aluminum hydroxide contains 20 to 40% by mass of aluminum hydroxide having a D50 (median diameter) of 20 μm or more.

[0044] The heat-resistant resin composition contains the heat-conductive particles in an amount of preferably 50 to 3,000 parts by mass, more preferably 100 to 2,000 parts by mass, and even more preferably 200 to 1,800 parts by mass, per 100 parts by mass of the matrix resin. This amount of addition can increase the thermal conductivity of the heat-resistant resin composition, and such a heat-resistant resin composition is suitable as a material for a heat-dissipating sheet: TIM (Thermal Interface Material) or a thermally conductive sheet.

[0045] The thermally conductive particles may be surface-treated with a coupling agent. Examples of the coupling agent include those represented by the formula R(CH3) a Si(OR') 4-a (R is an unsubstituted or substituted organic group having 1 to 20 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1), or a partial hydrolyzate thereof. Examples of the silane compound include methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, and octadecyltriethoxysilane. The silane compounds can be used alone or in combination of two or more. The thermally conductive particles may be surface-treated with preferably 0.1 to 90 parts by mass, more preferably 0.5 to 85 parts by mass of the silane coupling agent relative to 100 parts by mass of the thermally conductive particles, because the silane coupling agent coats the surfaces of the thermally conductive particles (surface treatment), and as a result, the thermally conductive particles become more easily filled into a matrix resin (plasticizer function).

[0046] The heat-resistant resin composition may further contain the silane coupling agent in an amount of preferably 0.1 to 10 parts by mass, more preferably 0.5 to 7 parts by mass, based on 100 parts by mass of the matrix resin. The silane coupling agent coats the surfaces of the thermally conductive particles and / or the heat-resistant auxiliary (surface treatment), and as a result, the thermally conductive particles and / or the heat-resistant auxiliary are easily filled into the matrix resin (plasticizer function).

[0047] <Curing catalyst (B component)> The heat-resistant resin composition of the present invention may further contain a curing catalyst. The curing catalyst may be a catalyst used in hydrosilylation reactions. Examples of the curing catalyst include platinum black, platinum (II) chloride, chloroplatinic acid, a reaction product of chloroplatinic acid with a monohydric alcohol, a complex of chloroplatinic acid with an olefin or vinylsiloxane, platinum-based catalysts such as platinum bisacetoacetate, palladium-based catalysts, and rhodium-based catalysts. Although a two-component curing silicone polymer usually contains a platinum-based metal catalyst, it is preferable to add an additional platinum-based metal catalyst to the heat-resistant resin composition of the present invention. The platinum-based metal catalyst is added to control the curing speed of the heat-resistant resin composition.

[0048] The curing catalyst is contained in the heat-resistant resin composition in an amount of, for example, 0.01 to 1,000 parts by mass, preferably 0.1 to 100 parts by mass, and more preferably 0.5 to 50 parts by mass, relative to 100 parts by mass of the matrix resin (component A).

[0049] <Other additives> The heat-resistant resin composition of the present invention may contain other components as necessary. For example, the heat-resistant resin composition may contain heat resistance improvers such as titanium oxide and cerium oxide, flame retardant assistants, etc. For the purpose of coloring and color matching, the heat-resistant resin composition may contain organic or inorganic pigments. The heat-resistant resin composition may contain the silane coupling agent.

[0050] <Physical properties of heat-resistant resin composition> The heat-resistant resin composition preferably has a hardness increase rate of 100% or less after 1000 hours at 150°C relative to the initial ASKER-C hardness, more preferably 10 to 80%, and even more preferably 10 to 50%. The lower the hardness increase rate after 1000 hours at 150°C relative to the initial ASKER-C hardness, the higher the heat resistance of the heat-resistant resin composition.

[0051] The heat-resistant resin composition of the present invention can be cured by heating or the like.

[0052] The ASKER-C hardness (initial value) of the heat-resistant resin composition is preferably 75 or less, more preferably 10 to 75, and further preferably 15 to 70. Such a heat-resistant resin composition exhibits good conformability to heat generating bodies and heat dissipating bodies (heat sinks).

[0053] The heat-resistant resin composition preferably has a dielectric breakdown voltage (JIS K6249) of 7 to 16 kV / mm. Such a heat-resistant resin composition can be made into a thermally conductive sheet having high electrical insulation properties.

[0054] The volume resistivity (JIS K6249) of the heat-resistant resin composition is 10 10 ~10 14 It is preferable that the resistivity is Ω·cm. Such a heat-resistant resin composition can be made into a thermally conductive sheet having high electrical insulation properties.

[0055] [Heat-resistant resin sheet] The heat-resistant resin composition of the present invention has high versatility when molded into a sheet, and is suitable as a TIM. The thickness of the heat-resistant resin sheet containing the heat-resistant resin composition is preferably in the range of 0.2 to 10 mm.

[0056] The heat-resistant resin sheet preferably has a hardness increase rate of 100% or less after 1000 hours at 150°C relative to the ASKER-C initial hardness, more preferably 10 to 80%, and even more preferably 10 to 50%. The lower the hardness increase rate after 1000 hours at 150°C relative to the ASKER-C initial hardness, the higher the heat resistance of the heat-resistant resin sheet.

[0057] The ASKER-C hardness (initial) of the heat-resistant resin sheet is preferably 75 or less, more preferably 10 to 75, and further preferably 15 to 70. Such a heat-resistant resin sheet has good conformability to a heat generating body and a heat dissipating body (heat sink).

[0058] The heat-resistant resin sheet preferably has a thermal conductivity of 1 W / m K or more, more preferably 1 to 20 W / m K, and further preferably 2 to 20 W / m K. Such a heat-resistant resin sheet has high thermal conductivity and is suitable as a heat dissipation sheet: TIM (Thermal Interface Material) or a thermally conductive sheet.

[0059] [Method of manufacturing heat-resistant resin sheet] The method for producing a heat-resistant resin sheet of the present invention includes a step of vacuum degassing the heat-resistant resin composition, rolling it, forming it into a sheet, and then heat curing it to obtain a heat-resistant resin sheet. Vacuum degassing can be performed by reducing the pressure of the heat-resistant resin composition to -0.08 to -0.1 Pa, leaving it for about 5 to 10 minutes, and degassing it. The rolling can be performed by roll rolling, press working, etc., but roll rolling is preferred because it allows continuous production.

[0060] The obtained heat-resistant resin sheet has a substantially uniform composition from inside to outside. The sheet with a uniform composition can exhibit uniform physical properties even after being mounted on an electric / electronic component as a TIM. In the roll rolling process, for example, the heat-resistant resin composition is sandwiched between two synthetic resin films and rolled from above with a roll. The heat curing conditions for the heat-resistant resin sheet are preferably a temperature of 90 to 120°C and a time of 5 to 180 minutes. In this specification, curing and crosslinking are the same.

[0061] The following description will be given with reference to the drawings. In the following drawings, the same reference numerals indicate the same objects. FIG. 1 is a schematic cross-sectional view of a heat-resistant resin sheet according to an embodiment of the present invention incorporated into a heat dissipation structure 10. The heat-resistant resin sheet 11b dissipates heat generated by an electronic component 13 such as a semiconductor element, is fixed to a main surface 12a of the heat spreader 12 facing the electronic component 13, and is sandwiched between the electronic component 13 and the heat spreader 2. The heat-resistant resin sheet 11a is sandwiched between the heat spreader 12 and a heat sink 15. The heat-resistant resin sheets 11a and 11b, together with the heat spreader 2, constitute a heat dissipation member that dissipates heat from the electronic component 13. The heat spreader 12 is formed, for example, in a rectangular plate shape, and has a main surface 12a facing the electronic component 13 and a side wall 12b erected along the outer periphery of the main surface 12a. The heat spreader 2 has a heat-resistant resin sheet 11b provided on a main surface 12a surrounded by side walls 12b, and a heat sink 15 provided on another surface 12c opposite to the main surface 12a via the heat-resistant resin sheet 11a. The electronic component 13 is, for example, a semiconductor element such as a BGA, and is mounted on a wiring board 14. In this case, the heat-resistant resin sheet functions as a thermally conductive sheet.

[0062] The present invention includes the following aspects. [Item 1] A heat-resistant resin composition comprising a matrix resin made of a thermosetting resin and a heat-resistant auxiliary, The heat-resistant resin composition, wherein the heat-resistant auxiliary is cellulose charcoal powder.

[0063] [Item 2] The cellulose charcoal powder is at least one charcoal powder selected from the group consisting of bamboo charcoal powder, wood charcoal powder, coconut shell charcoal powder, mangrove charcoal powder, plum berry charcoal powder, plum seed charcoal powder and rice husk charcoal powder, and is preferably bamboo charcoal powder, plum berry charcoal powder or wood charcoal powder. The heat-resistant resin composition according to item 1.

[0064] [Item 3] The heat-resistant resin composition according to item 1 or 2, wherein the cellulose charcoal powder has a cumulative particle size distribution D50 (median diameter) of 0.01 to 150 μm, preferably 0.05 to 130 μm, and more preferably 0.1 to 100 μm, based on a volume basis.

[0065] [Item 4] The heat-resistant resin composition according to any one of Items 1 to 3, comprising 0.1 to 20 parts by mass, preferably 0.5 to 15 parts by mass, and more preferably 1 to 10 parts by mass of the cellulose charcoal powder relative to 100 parts by mass of the matrix resin.

[0066] [Item 5] The matrix resin made of the thermosetting resin is at least one resin selected from the group consisting of silicone resin, acrylic resin, fluororubber, epoxy resin, phenol resin, unsaturated polyester resin, melamine resin, acrylic resin, fluororesin and non-reactive silicone oil, and is preferably a silicone resin and a non-reactive silicone oil. The heat-resistant resin composition according to any one of items 1 to 4.

[0067] [Item 6] The heat-resistant resin composition according to Item 5, wherein the silicone resin contains a base polymer (component A1) and a crosslinking component (A2).

[0068] [Item 7] The heat-resistant resin composition according to any one of Items 1 to 6, wherein the base polymer component is an organopolysiloxane containing two or more alkenyl groups bonded to silicon atoms in one molecule, preferably an organopolysiloxane having two or more alkenyl groups bonded to silicon atoms in one molecule, the alkenyl groups being vinyl groups, allyl groups or the like, and having 2 to 8 carbon atoms, particularly 2 to 6 carbon atoms, and more preferably an organopolysiloxane represented by general formula (I) containing alkenyl groups bonded to silicon atoms at both molecular chain terminals in one molecule, or a linear organopolysiloxane represented by general formula (II) having 1 to 3 alkenyl groups on each of the silicon atoms at both molecular chain terminals.

[0069] [ka]

[0070] During the ceremony, Each R 1 may be the same or different and are unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated bonds, R 2 is an alkenyl group, k is 0 or a positive integer.

[0071] [ka]

[0072] During the ceremony, Each R 3 may be the same or different and are unsubstituted or substituted monovalent hydrocarbon groups, at least one of which is an alkenyl group; Each R 4 may be the same or different and are unsubstituted or substituted monovalent hydrocarbon groups having no aliphatic unsaturated bonds, R 5 is an alkenyl group, l and m are each independently 0 or a positive integer.

[0073] [Item 8] The heat-resistant resin composition according to any one of Items 1 to 7, wherein the crosslinking component is an organohydrogenpolysiloxane, preferably an organohydrogenpolysiloxane having two or more hydrogen atoms bonded to silicon atoms (i.e., SiH groups) in one molecule, and more preferably an organohydrogenpolysiloxane represented by general formula (III).

[0074] [ka]

[0075] In the above formula, Each R 6 may be the same or different and are an alkyl group, a phenyl group, an epoxy group, an acryloyl group, a methacryloyl group, an alkoxy group, or a hydrogen atom, and at least two of them are hydrogen atoms. L is an integer from 0 to 1,000, preferably an integer from 0 to 300, M is an integer from 1 to 200.

[0076] [Item 9] The heat-resistant resin composition according to any one of Items 1 to 8, further comprising a curing catalyst. The curing catalyst is a catalyst used in a hydrosilylation reaction, and is preferably a platinum group metal catalyst such as platinum black, platinic chloride, chloroplatinic acid, a reaction product of chloroplatinic acid with a monohydric alcohol, a complex of chloroplatinic acid with an olefin or vinylsiloxane, a complex of platinum with vinyldisiloxane, platinum bisacetoacetate, or the like, a palladium catalyst, or a rhodium catalyst.

[0077] [Item 10] The heat-resistant resin composition according to Item 9, wherein the curing catalyst is contained in an amount of, for example, 0.01 to 1,000 parts by mass, preferably 0.1 to 100 parts by mass, and more preferably 0.5 to 50 parts by mass, per 100 parts by mass of the matrix resin (component A).

[0078] [Item 11] The heat-resistant resin composition according to any one of Items 1 to 10, further comprising thermally conductive particles, and the thermally conductive particles are more preferably at least one inorganic particle selected from the group consisting of aluminum oxide (alumina), zinc oxide, magnesium oxide, aluminum nitride, boron nitride, aluminum hydroxide and silicon carbide.

[0079] [Item 12] The heat-resistant resin composition according to Item 11, wherein the thermally conductive particles have a cumulative particle size distribution D50 (median diameter) of 0.01 to 150 μm, preferably 0.05 to 130 μm, and more preferably 0.1 to 100 μm.

[0080] [Item 13] When the total amount of the thermally conductive particles is 100 mass%, 50 to 90% by mass of alumina with a D50 (median diameter) of less than 20 μm, It is preferable that the aluminum hydroxide has a D50 (median diameter) of 20 μm or more and contains 10 to 50 mass % of the aluminum hydroxide. 60 to 80% by mass of alumina with a D50 (median diameter) of less than 20 μm, Item 13. The heat-resistant resin composition according to item 11 or 12, more preferably containing 20 to 40 mass % of aluminum hydroxide having a D50 (median diameter) of 20 μm or more.

[0081] [Item 14] The heat-resistant resin composition according to any one of Items 11 to 13, comprising 50 to 3,000 parts by mass, preferably 100 to 2,000 parts by mass, and more preferably 200 to 1,800 parts by mass of the thermally conductive particles relative to 100 parts by mass of the matrix resin.

[0082] [Item 15] The heat-resistant resin composition according to any one of Items 11 to 14, wherein at least a part of the thermally conductive particles is surface-treated with a coupling agent.

[0083] [Item 16] The coupling agent is a silane coupling agent, preferably represented by the formula R(CH3) a Si(OR') 4-a(R is an unsubstituted or substituted organic group having 1 to 20 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1), or a partial hydrolyzate thereof, more preferably methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, or octadecyltriethoxysilane.

[0084] [Item 17] The heat-resistant resin composition according to any one of Items 11 to 16, wherein the heat-resistant resin composition is a thermally conductive composition.

[0085] [Item 18] The heat-resistant resin composition according to any one of Items 1 to 16, wherein the heat-resistant auxiliary is surface-treated with a coupling agent.

[0086] [Item 19] The coupling agent is represented by the formula R(CH3) a Si(OR') 4-a Item 19. The heat-resistant resin composition according to item 18, wherein the silane compound is represented by the formula (1), (R is an unsubstituted or substituted organic group having 1 to 20 carbon atoms, R' is an alkyl group having 1 to 4 carbon atoms, and a is 0 or 1), or a partial hydrolyzate thereof, and is preferably methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, butyltrimethoxysilane, pentyltrimethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltrimethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, dodecyltrimethoxysilane, dodecyltriethoxysilane, hexadecyltrimethoxysilane, hexadecyltriethoxysilane, octadecyltrimethoxysilane, or octadecyltriethoxysilane.

[0087] [Item 20] The heat-resistant resin composition according to any one of items 1 to 19, wherein the hardness increase rate after holding at 150 ° C for 1000 hours is 100% or less, preferably 10 to 80%, and more preferably 10 to 50% relative to the ASKER-C initial hardness.

[0088] [Item 21] The heat-resistant resin composition according to any one of items 1 to 20, having an ASKER-C hardness (initial) of 75 or less, preferably 10 to 75, and more preferably 15 to 70.

[0089] [Item 22] A heat-resistant resin sheet comprising the heat-resistant resin composition according to any one of items 1 to 21 and formed into a sheet.

[0090] [Item 23] A heat-resistant resin sheet according to item 22, having a thermal conductivity of 1 W / m·K or more, preferably 1 to 20 W / m·K, and more preferably 2 to 20 W / m·K.

[0091] [Item 24] The heat-resistant resin sheet according to item 22 or 23, wherein the heat-resistant resin sheet has a thickness in the range of 0.2 to 10 mm.

[0092] [Item 25] A thermally conductive sheet comprising the heat-resistant resin composition according to any one of items 1 to 21 and formed into a sheet.

[0093] [Item 26] The thermally conductive sheet according to Item 25, having a thermal conductivity of 1 W / m·K or more, preferably 1 to 20 W / m·K, and more preferably 2 to 20 W / m·K.

[0094] [Item 27] ​​The thermally conductive sheet according to item 25 or 26, wherein the thermally conductive sheet has a thickness in the range of 0.2 to 10 mm.

[0095] [Item 28] A method for producing a heat-resistant resin sheet, comprising the steps of vacuum degassing the heat-resistant resin composition according to any one of items 1 to 21, rolling the composition, forming the composition into a sheet, and then heat-curing the sheet to obtain a heat-resistant resin sheet.

[0096] [Example] The present invention will be described below with reference to examples, but is not limited to these examples. Various parameters were measured by the methods described below.

[0097] <Thermal conductivity> The thermal conductivity of the heat-resistant resin sheet was measured using a hot disk (compliant with ISO 22007-2:2008). As shown in Figure 2A, this thermal conductivity measuring device 1 sandwiches a polyimide film sensor 2 between two samples 3a and 3b, applies a constant power to the sensor 2, and generates a constant amount of heat, analyzing the thermal characteristics from the temperature rise of the sensor 2. The sensor 2 has a tip 4 with a diameter of 7 mm, and as shown in Figure 2B, has a double spiral electrode structure, with an electrode 5 for applied current and an electrode 6 for resistance (electrode for temperature measurement) located at the bottom. The thermal conductivity is calculated using the following formula (Mathematical formula 1).

[0098]

number

[0099] <Initial hardness> The initial hardness was measured using an ASKER-C hardness tester immediately after the heat-resistant resin composition was prepared, and this was defined as the initial ASKER-C hardness (A).

[0100] <Hardness increase rate> The hardness after 1000 hours at 150°C was measured using an ASKER-C hardness tester after placing the heat-resistant resin composition in an oven at 150°C and holding it for 1000 hours. This was taken as the hardness after 1000 hours at 150°C (B). The hardness increase rate was calculated from the data of the initial ASKER-C hardness (A) and the hardness after 1000 hours at 150°C (B) using the following formula. Hardness increase rate = [(BA) / A] x 100 A: Initial ASKER-C hardness B: Hardness after 1000 hours at 150℃

[0101] <Viscosity> The initial viscosity was measured for the heat-resistant resin composition (thickness at the time of measurement: 0.5 mm) immediately after preparation using a viscosity / viscoelasticity measuring device MARSIII (manufactured by HAAKE) at a rotation speed of 1.0 (1 / s) and 25°C. The viscosity after 150°C for 1000 hours was measured using a viscosity and viscoelasticity measuring device MARSIII (manufactured by HAAKE) at a rotation speed of 1.0 (1 / s) and 25°C after storing the heat-resistant resin composition in a constant temperature bath at 150°C for 1000 hours. The viscosity increase rate after 150°C for 1000 hours was calculated from the obtained viscosity value using the following formula. Viscosity increase rate after 1000 hours at 150℃ = [(YX) / X] x 100 X: initial viscosity Y: Viscosity after 1000 hours at 150℃

[0102] [Example 1] 1.Material (1) Matrix resin (Component A): A total of 100 g of components A and B of a commercially available two-component silicone polymer (addition-curing silicone) containing polyorganosiloxane was used. One component (Component A) contains a base polymer component (polyorganosiloxane, Component A1 of Component A) and a platinum group metal catalyst, while the other component (Component B) contains a base polymer component (polyorganosiloxane, Component A1 of Component A) and a crosslinking agent component (Component A2 of Component A), organohydrogenpolysiloxane. The ratio of components A and B is A:B = 100:100 by mass. This two-component silicone polymer undergoes addition curing when mixed at room temperature to become a silicone resin. (2) Curing catalyst (component B): 0.5 g of a commercially available platinum catalyst was used. (3) Thermally conductive particles (component C): The thermally conductive particles shown in Table 1 were used. The average particle size is the D50 (median diameter) of the cumulative particle size distribution based on volume in particle size distribution measurement by laser diffraction light scattering method. 512 g of alumina (C1) with a D50 (median diameter) of 4.6 μm and 232 g of aluminum hydroxide (C2) with a D50 (median diameter) of 49 μm were used. An example of a device for measuring the median diameter is the LA-950S2 laser diffraction / scattering particle distribution measuring device manufactured by Horiba, Ltd. (C1): Alumina (D50 = 4.6 μm, of which 82 mass% is surface-treated with a silane coupling agent (decyltrimethoxysilane)) (C2): Aluminum hydroxide (D50 = 49 μm) (4) Heat resistance aid (D component): 7 g of commercially available bamboo charcoal powder (manufactured by Suncall Co., Ltd., product name "Kyoto Kaguya Charcoal", D50 (median diameter) = 1.8 μm) was used. Figure 3 shows an enlarged SEM photograph (magnification 1000 times) of this bamboo charcoal powder.

[0103] 2. Heat-resistant resin composition The amounts of each material shown in Table 1 were weighed out and placed in a mixer to obtain a heat-resistant resin composition. The numerical values ​​for each material in Table 1 indicate parts by mass (g). This heat-resistant resin composition was degassed for 5 minutes under reduced pressure of -0.1 Pa.

[0104] 3.Sheet forming process The heat-resistant resin composition was sandwiched between release-treated polyethylene terephthalate (PET) films, rolled into a sheet with a thickness of 2.0 mm using a constant speed roll, and cured by heating at 100°C for 10 minutes to form a heat-resistant resin sheet with a thickness of 2.0 mm. The thermal conductivity of this heat-resistant resin sheet was 2.3 W / m K.

[0105] [Example 2] A heat-resistant resin sheet was obtained in the same manner as in Example 1, except that the amount of bamboo charcoal powder added was 3.5 g.

[0106] [Example 3] A heat-resistant resin sheet was obtained in the same manner as in Example 1, except that the amount of bamboo charcoal powder added was 1.75 g.

[0107] [Example 4] A heat-resistant resin sheet was obtained in the same manner as in Example 1, except that bamboo charcoal powder having a D50 (median diameter) of 5.0 μm was used instead of the bamboo charcoal powder having a D50 (median diameter) of 1.8 μm.

[0108] [Example 5] A heat-resistant resin sheet was obtained in the same manner as in Example 2, except that plum seed charcoal powder (manufactured by Furusato Food Research Institute Co., Ltd., product name "Plum seed charcoal powder") having a D50 (median diameter) of 5.6 μm was used instead of bamboo charcoal powder having a D50 (median diameter) of 1.8 μm.

[0109] [Comparative Example 1] A heat-resistant resin sheet was obtained in the same manner as in Example 1, except that the heat-resistant auxiliary (component D) was not added.

[0110] [Comparative Example 2] A heat-resistant resin sheet was obtained in the same manner as in Example 1, except that 7 g of iron oxide (D50 (median diameter) 0.17 μm), which is a conventional color pigment, was added instead of the heat-resistant auxiliary (component D).

[0111] The composition of the heat-resistant resin composition and the results of various parameters of the obtained heat-resistant resin composition and heat-resistant resin sheet are shown in Tables 1 and 2. In addition, a graph showing the results of ASKER-C hardness when the heat-resistant resin sheet was stored in a thermostatic chamber at 150°C for up to 1000 hours is shown in Figure 4.

[0112] [Table 1]

[0113] [Table 2]

[0114] As can be seen from Tables 1 and 2 and FIG. 4, in Examples 1 to 5 of the present invention, the ASKER-C hardness increase rate after the heat-resistant resin sheet was stored in a constant temperature bath at 150° C. for 1,000 hours was 50% or less, which was confirmed to be significantly higher in heat resistance than 205% in Comparative Example 1 and 170% in Comparative Example 2.

[0115] [Example 6] Commercially available bamboo charcoal powder (manufactured by Suncall Co., Ltd., product name "Kyo Kaguya Charcoal", D50 (median diameter) = 1.8 μm) and a silane coupling agent (decyltrimethoxysilane) were placed in a container so that the mass ratio of bamboo charcoal powder:silane coupling agent was 10:1, and the surface was treated by stirring with a planetary stirring and defoaming device. A heat-resistant resin sheet was obtained in the same manner as in Example 1, except that 17 g of this surface-treated bamboo charcoal powder was used instead of 7 g of commercially available bamboo charcoal powder (manufactured by Suncall Co., Ltd., product name "Kyo Kaguya Charcoal", D50 (median diameter) = 1.8 μm). The obtained heat-resistant resin sheet maintained its shape, and the PET film could be cleanly peeled off, and the shape was maintained. Therefore, it was confirmed that the heat-resistant resin sheet of Example 6 exhibited the effect of excellent curability.

[0116] [Example 7] 1.Material (1) Matrix resin (component A): Commercially available dimethyl silicone oil (dynamic viscosity at 25°C: 1,800 mm 2 / s)100g was used. (2) Curing catalyst (component B): Not used. (3) Thermally conductive particles (component C): The thermally conductive particles shown in Table 3 were used. The average particle size is the D50 (median diameter) of the cumulative particle size distribution based on volume in particle size distribution measurement by laser diffraction light scattering method. 614.4 g of alumina (C1) with a D50 (median diameter) of 4.6 μm and 278.4 g of aluminum hydroxide (C2) with a D50 (median diameter) of 49 μm were used. An example of a device for measuring the median diameter is the LA-950S2 laser diffraction / scattering particle distribution measuring device manufactured by Horiba, Ltd. (C1): Alumina (D50 = 4.6 μm, of which 82 mass% is surface-treated with a silane coupling agent (decyltrimethoxysilane)) (C2): Aluminum hydroxide (D50 = 49 μm) (4) Heat resistance aid (component D): 3.5 g of commercially available bamboo charcoal powder (manufactured by Suncall Co., Ltd., product name "Kyoto Kaguya Charcoal", D50 (median diameter) = 1.8 μm) was used.

[0117] 2. Heat-resistant resin composition The amounts of each material shown in Table 3 were weighed out and placed in a mixer to obtain a heat-resistant resin composition. The numerical values ​​for each material in Table 3 indicate parts by mass (g). This heat-resistant resin composition was degassed for 5 minutes under reduced pressure of -0.1 Pa.

[0118] [Comparative Example 3] A heat-resistant resin composition was obtained in the same manner as in Example 7, except that the heat-resistant auxiliary (component D) was not used.

[0119] [Comparative Example 4] A heat-resistant resin composition was obtained in the same manner as in Example 7, except that 3.5 g of iron oxide (D50 (median diameter) = 0.2 μm), which is a conventional color pigment, was added instead of the heat-resistant auxiliary (component D).

[0120] The composition of the heat-resistant resin composition and the results of various parameters of the obtained heat-resistant resin composition are shown in Tables 3 and 4. In addition, a graph showing the change in viscosity of the heat-resistant resin composition over time is shown in FIG.

[0121] [Table 3]

[0122] [Table 4]

[0123] As shown in Tables 3 and 4 and Fig. 5, it was confirmed that even in the case of an uncured heat-resistant resin composition, Example 7 containing the heat-resistant auxiliary (D) was able to suppress the viscosity increase rate after storage for 1000 hours at 150°C. In other words, it was confirmed that the heat-resistant resin composition of the present invention was able to suppress the viscosity increase rate even after storage at high temperatures and had excellent heat resistance.

[0124] The heat-resistant resin composition and heat-resistant resin sheet of the present invention are suitable as a heat-dissipating sheet (TIM (Thermal Interface Material)) or a thermally conductive sheet to be interposed between a heat-generating portion of an electric or electronic part and a heat sink.

[0125] [Explanation of symbols] 1. Thermal conductivity measuring device 2 Sensors 3a,3b Sample 4 Sensor tip 5 Electrode for applied current 6 Resistance electrodes (temperature measurement electrodes) 10 Heat dissipation structure 11a, 11b Heat-resistant resin sheet 12 Heat spreader 13. Electronic Components 14 Wiring board 15 Heat sink

Claims

1. A heat-resistant resin composition comprising a matrix resin made of a thermosetting resin, thermally conductive particles, and a heat-resistant auxiliary, The heat resistance aid is cellulose charcoal powder, The thermally conductive particles are at least one inorganic particle selected from the group consisting of aluminum oxide (alumina), zinc oxide, magnesium oxide, aluminum nitride, boron nitride, and aluminum hydroxide. Heat-resistant resin composition.

2. 2. The heat-resistant resin composition according to claim 1, wherein the cellulose charcoal powder is at least one charcoal powder selected from the group consisting of bamboo charcoal powder, wood charcoal powder, coconut shell charcoal powder, mangrove charcoal powder, plum kernel charcoal powder, plum seed charcoal powder, and rice husk charcoal powder.

3. 2. The heat-resistant resin composition according to claim 1, wherein the cellulose charcoal powder has a cumulative particle size distribution D50 (median diameter) of 0.01 to 150 μm on a volume basis.

4. 2. The heat-resistant resin composition according to claim 1, wherein the cellulose charcoal powder is contained in an amount of 0.1 to 20 parts by mass per 100 parts by mass of the matrix resin.

5. 2. The heat-resistant resin composition according to claim 1, wherein the matrix resin comprising a thermosetting resin is at least one resin selected from the group consisting of silicone resin, acrylic resin, fluororubber, epoxy resin, phenolic resin, unsaturated polyester resin, melamine resin, acrylic resin, fluororesin, and non-reactive silicone oil.

6. 2. The heat-resistant resin composition according to claim 1, wherein the heat-conductive particles are contained in an amount of 50 to 3,000 parts by mass per 100 parts by mass of the matrix resin.

7. 2. The heat-resistant resin composition according to claim 1, wherein at least a portion of the thermally conductive particles is surface-treated with a coupling agent.

8. 2. The heat-resistant resin composition according to claim 1, wherein the heat-resistant resin composition exhibits a hardness increase rate of 100% or less after being maintained at 150° C. for 1000 hours relative to the initial ASKER-C hardness.

9. A heat-resistant resin sheet comprising the heat-resistant resin composition according to any one of claims 1 to 8 and formed into a sheet.

10. The heat-resistant resin sheet according to claim 9, wherein the thickness of the heat-resistant resin sheet is in the range of 0.2 to 10 mm.

11. A method for producing a heat-resistant resin sheet, comprising the steps of vacuum degassing, rolling, and forming a heat-resistant resin composition according to any one of claims 1 to 8 into a sheet, and then heat-curing the sheet to obtain a heat-resistant resin sheet.

Images