Resin composition for motor sealing

Abstract

To provide a resin composition for motor sealing which is suitable for sealing part or all of components that constitute a motor.SOLUTION: A resin composition for motor sealing is a resin composition for sealing part or all of components constituting a motor and contains the following (A) to (E): (A) an epoxy resin; (B) a hydrosilylation reaction product of an alkenyl group-containing epoxy compound and an organopolysiloxane having one or more hydrosilyl groups per molecule; (C) a phenolic curing agent; (D) a black pigment; and (E) an inorganic filler (excluding the black pigment of (D)).SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] In recent years, motors have been used in a wide range of fields, including hybrid and electric vehicles, railways, and generators, and there is an increasing demand for smaller motors with higher output. To meet these demands, measures such as increasing the coil occupancy rate in motors and measures to prevent heat generation in motors are being investigated.

[0003] Epoxy resins are preferably used as resins for impregnating and sealing coils because they have excellent heat resistance and chemical resistance as well as excellent mechanical properties. Conventionally, a composition using aluminum oxide as a highly thermally conductive inorganic filler in an epoxy resin has been known as a highly thermally conductive resin (Patent Document 1). Also known are compositions using boron nitride or magnesium oxide as a highly thermally conductive inorganic filler for the purpose of improving thermal conductivity (Patent Documents 2 and 3). However, when a large amount of a thermally conductive inorganic filler is blended into a composition in order to improve thermal conductivity, the elastic modulus of the cured product of the composition increases, and the cured product cannot withstand the stress changes in a temperature cycle test, making it prone to cracking. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-013034 [Patent Document 2] Patent Publication No. 2021-031600 [Patent Document 3] Japanese Patent Publication No. 2020-117688 Summary of the Invention [Problem to be solved by the invention]

[0005] Therefore, an object of the present invention is to provide a resin composition for sealing a motor that is suitable for sealing part or all of the components constituting a motor. Specifically, an object of the present invention is to provide a resin composition that gives a cured product with a low elastic modulus and excellent heat resistance even when the resin composition contains a large amount of inorganic filler. [Means for solving the problem]

[0006] As a result of extensive research to solve the above problems, the present inventors have found that the following resin composition for sealing a motor can achieve the above object, and have thus completed the present invention. That is, the present invention provides the following resin composition for sealing a motor.

[0007] [1] A resin composition for sealing a part or all of the components constituting a motor, the resin composition for sealing a motor comprising the following (A) to (E): (A) Epoxy resin: 20 to 60 parts by mass per 100 parts by mass of the total of the (A) component, the (B) component and the (C) component described below (B) a hydrosilylation reaction product of an alkenyl group-containing epoxy compound with any one of organopolysiloxanes having one or more hydrosilyl groups per molecule and represented by the following formulas (1) to (3): 2 to 25 parts by mass per 100 parts by mass of the total of components (A), (B), and (C) described below: [ka] (In formula (1), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are independently a group represented by the following formula (1'): 1 is a number between 5 and 200, and n 2 is a number between 0 and 2, and n 3 is a number between 0 and 10, and n 4 is 0 or 1. However, the above R 1 At least one of the is a hydrogen atom.) [ka] (In formula (1'), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n 5 is a number between 1 and 10.) [ka] (In formula (2), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n 6 is a number between 1 and 10, and n 7 is 1 or 2, where n 6 +n 7 is a number between 3 and 12.) [ka] (In formula (3), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, r is a number from 0 to 3, and R 3 is a hydrogen atom or one or more groups selected from alkyl groups having 1 to 10 carbon atoms and alkoxyalkyl groups having 2 to 10 carbon atoms, and R 1 and R 3 At least one of these is a hydrogen atom.) (C) Phenol-based curing agent: 20 to 50 parts by mass per 100 parts by mass of the total of the components (A), (B), and (C). (D) Black pigment: 0.5 parts by mass or more of the component (D) per 100 parts by mass of the total of the components (A), (B), and (C). (E) Inorganic filler (excluding (D) black pigment): 100 to 2,000 parts by mass per 100 parts by mass of the total of components (A), (B), and (C) [2] The resin composition for sealing a motor according to [1], wherein the inorganic filler (E) comprises at least one selected from alumina, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, silicon nitride, and diamond. [3] (E) The resin composition for sealing a motor according to [1] or [2], wherein the volume average particle size of the inorganic filler is 3 to 40 μm. [4] The resin composition for sealing a motor according to any one of [1] to [3], wherein the epoxy resin (A) comprises at least one selected from a novolac type epoxy resin, an aralkyl type epoxy resin, and a crystalline epoxy resin. [5] The motor-sealing resin composition according to any one of [1] to [4], wherein the component constituting the motor is a rotor. [Effects of the Invention]

[0008] The motor sealing resin composition of the present invention has excellent flowability even when it contains a large amount of inorganic filler, making it suitable for sealing part or all of the components that make up a motor. In addition, the cured product thereof has excellent toughness, a low elastic modulus, heat resistance, and thermal conductivity while maintaining its electrical properties. [Brief explanation of the drawings]

[0009] [Figure 1] This is a perspective view of a three-point bending test specimen used to measure fracture toughness (K1C). S represents the distance between supports (64 mm), B represents the specimen width (4 mm), and W represents the specimen thickness (10 mm). [Figure 2] 2 is an enlarged view (partially enlarged view) of the dashed line portion in the perspective view of FIG. 1. a indicates the length of the notch (2 mm). DETAILED DESCRIPTION OF THE INVENTION

[0010] The present invention will be described in detail below.

[0011] [(A) Epoxy resin] Examples of the epoxy resin of component (A) include epoxy resins conventionally used in the technical field of encapsulating epoxy resin compositions. Examples of such epoxy resins include novolac epoxy resins such as phenol novolac epoxy resins, orthocresol novolac epoxy resins, and naphthol novolac epoxy resins; crystalline epoxy resins such as biphenyl epoxy resins, bisphenol epoxy resins, stilbene epoxy resins, and dihydroanthracene diol epoxy resins; polyfunctional epoxy resins such as triphenolmethane epoxy resins and alkyl-modified triphenolmethane epoxy resins; phenol aralkyl epoxy resins having a phenylene skeleton, biphenyl aralkyl epoxy resins having a biphenylene skeleton, and phenylene aralkyl epoxy resins. Examples of suitable epoxy resins include aralkyl epoxy resins such as naphthol aralkyl epoxy resins having a biphenylene skeleton and naphthol biphenyl aralkyl epoxy resins having a biphenylene skeleton; naphthol epoxy resins such as dihydroxynaphthalene epoxy resins and epoxy resins obtained by glycidyl etherifying a dihydroxynaphthalene dimer; triazine nucleus-containing epoxy resins such as triglycidyl isocyanurate and monoallyl diglycidyl isocyanurate; and cyclic hydrocarbon compound-modified phenolic epoxy resins such as dicyclopentadiene-modified phenolic epoxy resins. These may be used alone or in combination of two or more. Among these, from the viewpoint of moldability, novolac epoxy resins such as orthocresol novolac epoxy resins, aralkyl epoxy resins such as biphenyl aralkyl epoxy resins, and crystalline epoxy resins such as biphenyl epoxy resins are preferred, and biphenyl epoxy resins are particularly preferred because they can maintain a low viscosity of the composition.

[0012] The component (A) is contained in an amount of 20 to 60 parts by mass, and preferably 20 to 40 parts by mass, per 100 parts by mass of the total of the component (A), the component (B) and the component (C) described below.

[0013] The total content of the component (A) and the components (B) and (C) described below in the encapsulated epoxy resin composition of the present invention is preferably 5 to 20 mass %, more preferably 5 to 10 mass %.

[0014] [(B) Hydrosilylation reaction product of an alkenyl group-containing epoxy compound and an organopolysiloxane having one or more hydrosilyl groups per molecule] Component (B) is a hydrosilylation reaction product (copolymer) of an alkenyl group-containing epoxy compound and an organopolysiloxane having one or more hydrosilyl groups per molecule, represented by any of the following formulas (1) to (3): By containing this copolymer, the composition of the present invention has a cured product with high heat resistance and moisture resistance.

[0015] Organopolysiloxane represented by formula (1) [ka] (In formula (1), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are independently a group represented by the following formula (1'): 1 is a number between 5 and 200, and n 2 is a number between 0 and 2, and n 3 is a number between 0 and 10, and n 4 is 0 or 1. However, the above R 1 At least one of the is a hydrogen atom.)

[0016] In the above formula (1), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, neopentyl, hexyl, octyl, nonyl, and decyl; alkenyl groups such as vinyl, allyl, propenyl, isopropenyl, butenyl, hexenyl, cyclohexenyl, and octenyl; aryl groups such as phenyl, tolyl, xylyl, and naphthyl; and aralkyl groups such as benzyl, phenylethyl, and phenylpropyl. Of these, methyl, ethyl, and phenyl groups are preferred.

[0017] R 1 are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms. Specific examples of this monovalent hydrocarbon group include the same groups as those exemplified for R above. 2 is a group represented by the following formula (1'). [ka] (In formula (1'), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n 5 is a number between 1 and 10.)

[0018] In the above formula (1), n 1 is a number from 5 to 200, preferably from 10 to 100. 2 is a number from 0 to 2, preferably 0 or 1. 3 is a number from 0 to 10, preferably from 0 to 2. 4 is 0 or 1, preferably 1. In addition, R in the above formula (1) 1 At least one, preferably 1 to 2 of the n 2 If =0, R 1 One or more, preferably 1 to 3, of these are hydrogen atoms.

[0019] In the above formula (1′), R and R 1 is the same as above, and n 5 is a number from 1 to 10, preferably from 1 to 6.

[0020] Organopolysiloxane represented by formula (2) [ka] (In formula (2), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n 6 is a number between 1 and 10, and n 7 is 1 or 2, where n 6 +n 7is a number between 3 and 12.)

[0021] In the above formula (2), R is the same as above. 6 is a number from 1 to 10, preferably from 4 to 8. 7 is 1 or 2, preferably 2, provided that n 6 +n 7 is a number from 3 to 12, preferably from 3 to 8.

[0022] Organopolysiloxane represented by formula (3) [ka] (In formula (3), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, r is a number from 0 to 3, and R 3 is a hydrogen atom or one or more groups selected from alkyl groups having 1 to 10 carbon atoms and alkoxyalkyl groups having 2 to 10 carbon atoms, and R 1 and R 3 At least one of these is a hydrogen atom.)

[0023] In the above formula (3), R and R 1 is the same as above. r is a number from 0 to 3, preferably 2 or 3. R 3 is a hydrogen atom, or one or more groups selected from alkyl groups and alkoxyalkyl groups having 2 to 10 carbon atoms, and R 1 and R 3 At least one of these is a hydrogen atom.

[0024] Suitable organopolysiloxanes include hydrogen-terminated polysiloxanes, hydrogen-terminated methylphenyl polysiloxanes, etc. For example, the following compounds are preferred: [ka] (wherein n is a number from 20 to 100, preferably from 20 to 60)

[0025] [ka] (In the formula, m is a number from 1 to 10, preferably from 1 to 5, and n is a number from 10 to 100, preferably from 20 to 60. The siloxane units bounded by m and n may be bonded in either a block or random manner.)

[0026] The alkenyl-containing epoxy compound used as the raw material for component (B) can be obtained, for example, by epoxidizing an alkenyl-containing phenolic resin with epichlorohydrin or by partially reacting a conventionally known epoxy compound with 2-allylphenol. The epoxy compound can be represented, for example, by the following formula (4) or (5). [ka] (In the formula, R 1 is an aliphatic monovalent hydrocarbon group having an alkenyl group and having 3 to 15 carbon atoms, preferably 3 to 5 carbon atoms, and R 2 is a glycidyloxy group or a group represented by -OCH2CH(OH)CH2OR', R' is a monovalent hydrocarbon group having an alkenyl group and having 3 to 10 carbon atoms, preferably 3 to 5 carbon atoms, k is 1, k' is 0 or 1, x is a number from 1 to 30, and y is a number from 1 to 3. The repeating units bounded by x and y may be bonded in either a block or random fashion. [ka] (In the formula, R 1 is an aliphatic monovalent hydrocarbon group having an alkenyl group and having 3 to 15 carbon atoms, preferably 3 to 5 carbon atoms, and R 2is a glycidyloxy group or a group represented by -OCH2CH(OH)CH2OR', R' is a monovalent hydrocarbon group having an alkenyl group and 3 to 10 carbon atoms, preferably 3 to 5 carbon atoms, k is 1, k' is 0 or 1, x' is a number from 1 to 30, and y' is a number from 1 to 3. The repeating units bounded by x' and y' may be bonded in a block or random fashion.

[0027] Examples of the epoxy compound represented by the above formula include compounds represented by the following formula: [ka] (In the above formula, x and y are numbers expressed as 1≦x≦20 and 1≦y≦3, and preferably 1≦x≦20 and y=1. The repeating units bounded by x and y may be bonded in block or random fashion.)

[0028] Component (B) is a hydrosilylation reaction product (copolymer) of the alkenyl group-containing epoxy compound and organopolysiloxane. The hydrosilylation reaction may be carried out according to a conventional method. For example, the hydrosilylation reaction may be carried out by heating in the presence of a platinum catalyst such as chloroplatinic acid. The hydrosilylation reaction is preferably carried out in an inert solvent such as benzene, toluene, or methyl isobutyl ketone, by heating at 60 to 120°C. The ratio of the alkenyl group-containing epoxy compound to the organopolysiloxane is preferably such that the number of hydrosilyl groups in the organopolysiloxane per alkenyl group in the alkenyl group-containing epoxy compound is 1.0 or more, preferably 1.5 to 5.0. The component (B) may be used alone or in combination of two or more.

[0029] The amount of component (B) in the composition is 2 to 25 parts by mass, and preferably 5 to 15 parts by mass, per 100 parts by mass of the total of components (A), (B), and (C) described below. If the content of component (B) is less than 2 parts by mass per 100 parts by mass of the total of components (A), (B), and (C), described below, the resin composition may foam, resulting in resin leakage or voids during molding. Furthermore, the elastic modulus of the cured product of the composition may increase, causing cracks in the cured product. On the other hand, if the content of component (B) is more than 20 parts by mass per 100 parts by mass of the total of components (A), (B), and (C), described below, the viscosity of the resin composition may increase, resulting in insufficient filling of narrow spaces with resin, and other molding defects.

[0030] [(C) Phenol-based curing agent] Examples of the phenolic curing agent of component (C) include phenol novolac resin, phenol aralkyl resin, biphenyl aralkyl resin, triphenylalkane type phenol resin, dicyclopentadiene modified phenol resin, etc. These may be used alone or in combination of two or more. The amount of component (C) in the composition is preferably 20 to 50 parts by mass, and more preferably 30 to 40 parts by mass, per 100 parts by mass of the total of components (A), (B), and (C).

[0031] [(D) Black pigment] Examples of the black pigment of component (D) include, but are not limited to, carbon black, furnace black, acetylene black, etc., which are used in conventional encapsulating resin compositions. Carbon black is preferred. By rendering the resin composition of the present invention black, a semiconductor device manufactured using this as a semiconductor encapsulant can have good appearance and laser marking properties similar to those of semiconductor devices encapsulated with conventional epoxy resins, etc. The amount of component (D) in the composition is 0.5 parts by mass or more, and preferably 1 to 5 parts by mass, per 100 parts by mass of the total of components (A), (B), and (C). An amount of 0.5 parts by mass or more is preferable because it prevents the gloss from becoming too high, suppresses poor appearance due to traces of the semiconductor element being transferred to the surface of the semiconductor device, and provides a sufficiently black color with good laser marking properties. The average particle size of the black pigment of component (D) is preferably 0.5 to 45 μm, more preferably 0.5 to 40 μm, as measured by a volume average particle size distribution analyzer using a laser diffraction particle size distribution analyzer.

[0032] [(E) Inorganic filler] Examples of inorganic fillers for component (E) include fused silica, crystalline silica, cristobalite, alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, alumina fiber, zinc oxide, talc, calcium carbide, and the like (excluding the above-mentioned component (D)). These can be used alone or in combination of two or more. Of these, it is preferable to include any one of alumina, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, silicon nitride, and diamond in order to achieve high thermal conductivity.

[0033] The volume average particle size of the (E) inorganic filler measured with a laser diffraction particle size distribution analyzer is preferably 3 to 40 μm, more preferably 10 to 20 μm. The amount of component (E) in the composition is preferably 100 to 2,000 parts by mass, and more preferably 500 to 1,600 parts by mass, per 100 parts by mass of the total of components (A), (B), and (C). If the amount of component (E) is less than 50% by mass of the total resin composition, the thermal conductivity of the resin composition will be difficult to improve, whereas if it is more than 95% by mass, the viscosity of the composition will increase significantly, which may result in poor moldability. Furthermore, from the viewpoint of increasing the fluidity of the resin composition of the present invention, a combination of multiple particle size ranges may be used as the inorganic filler. In such a case, it is preferable to use a combination of a fine particle range of 0.1 to 3 μm and a medium particle size range of 3 to 10 μm.

[0034] Other additives The resin composition of the present invention may further contain a curing accelerator, an adhesion promoter, a release agent, a flame retardant, an ion trapping agent, a flexibility-imparting agent, and other additives within a range that does not impair the effects of the present invention.

[0035] Examples of the curing accelerator include imidazole compounds (for example, 2-phenyl-4-methyl-5-hydroxymethylimidazole), organic phosphorus compounds, and 1,8-diazabicyclo(5,4,0)undecene-7.

[0036] Examples of adhesion promoters include epoxy silanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino silanes such as N-(2-aminoethyl)-γ-aminopropyltrimethoxysilane, a reaction product of imidazole and 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane; and mercaptosilanes such as 3-mercaptopropyltrimethoxysilane and 3-(thiiranylmethoxy)propyltrimethoxysilane. These may be used alone or in combination of two or more.

[0037] Examples of the release agent include waxes such as carnauba wax, rice wax, polyethylene, polyethylene oxide, montanic acid, ester compounds of montanic acid with saturated alcohols, 2-(2-hydroxyethylamino)-ethanol, ethylene glycol, glycerin, etc.; stearic acid, stearic acid esters, stearic acid amide, ethylene bisstearic acid amide, copolymers of ethylene and vinyl acetate, etc., and these may be used alone or in combination of two or more.

[0038] Examples of the flame retardant include halogenated epoxy resins, phosphazene compounds, silicone compounds, zinc molybdate-supported talc, zinc molybdate-supported zinc oxide, aluminum hydroxide, magnesium hydroxide, molybdenum oxide, antimony trioxide, etc. These flame retardants may be used alone or in combination of two or more, but from the viewpoints of environmental load and ensuring fluidity, phosphazene compounds, zinc molybdate-supported zinc oxide, and molybdenum oxide are preferably used.

[0039] Examples of the ion trapping agent include hydrotalcite compounds, bismuth compounds, and zirconium compounds, and these may be used alone or in combination of two or more.

[0040] Examples of the flexibility-imparting agent include silicone compounds such as silicone oil, silicone resin, silicone-modified epoxy resin, and silicone-modified phenolic resin, and thermoplastic elastomers such as styrene resin and acrylic resin, and these may be used alone or in combination of two or more.

[0041] The content of these other additives in the resin composition may be determined appropriately within a range that allows each additive to exhibit its function well. For example, the content of each additive is in the range of 0.1 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the total of the (A) component, the (B) component, and the (C) component.

[0042] Method for producing the composition The resin composition of the present invention can be produced, for example, as follows: (A) epoxy resin, (B) hydrosilylation reaction product (copolymer) of an alkenyl group-containing epoxy compound with an organopolysiloxane having one or more hydrosilyl groups per molecule, (C) phenolic curing agent, (D) black pigment, (E) inorganic filler (excluding component (D)), and other materials as needed are blended in predetermined amounts, thoroughly and uniformly mixed using a mixer or the like, and then melt-mixed using a heated roll, kneader, extruder, or the like. The resulting mixture is then cooled and solidified, and pulverized to an appropriate size. The resulting cured composition can be used as a molding material. It can also be tableted and used in tablet form. [Example]

[0043] EXAMPLES The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. The components used in the examples and comparative examples are as follows:

[0044] (A) Epoxy resin A-1 Biphenyl-type epoxy resin: Mitsubishi Chemical Corporation's "YX4000K" (epoxy equivalent: 195) A-2 Cresol novolac epoxy resin: Nippon Kayaku "EOCN1027" (epoxy equivalent weight 200)

[0045] (B) Hydrosilylation reaction product (copolymer) of an alkenyl group-containing epoxy compound with an organopolysiloxane having one or more hydrosilyl groups per molecule A 2L four-neck flask equipped with a reflux condenser, thermometer, stirrer, and dropping funnel was charged with 400 g of toluene and 10 g of an allyl group-containing epoxy resin (epoxy equivalent: 310) represented by formula (6) below. The mixture was then azeotropically dehydrated for 2 hours under a nitrogen atmosphere. The system was then cooled to 80°C, 1.00 g of platinum chloride catalyst was added, and a solution of 48.5 g of an organosilicon compound represented by formula (7) below in 194.1 g of toluene was added dropwise over 2 hours. The system was stirred for 6 hours while maintaining the temperature at 90-100°C, aged, and then cooled to room temperature. The solvent was then distilled off under reduced pressure, yielding 56.2 g of the desired silicone-modified epoxy resin (Compound A, epoxy equivalent: 402).

[0046] [ka] (In the above formula (6), s = 1 to 30, and t = 1 to 3.)

[0047] (C) Phenol-based hardener Phenol novolac resin: UBE "H-4" (phenolic hydroxyl equivalent: 110)

[0048] (D) Black pigment Carbon-based black pigment: Mitsubishi Chemical Corporation's "Mitsubishi Carbon Black 3230B"

[0049] (E) Inorganic filler Spherical alumina: Denka, average particle size = 15 μm

[0050] (F) Other ingredients (curing accelerator) 2-Phenyl-4-methyl-5-hydroxymethylimidazole: Shikoku Chemicals Corporation "Curezol 2P4MHZ-PW" (adhesion imparting agent) Adhesion promoter 1: 3-glycidoxypropyltrimethoxysilane: Shin-Etsu Chemical Co., Ltd. "KBM-403" Adhesion promoter 2: 3-mercaptopropyltrimethoxysilane: Shin-Etsu Chemical Co., Ltd. "KBM-803" (mold release agent) Carnauba wax: TOWAX-131 manufactured by Toa Kasei Co., Ltd. (Flame retardant) Flame retardant 1: Phosphazene compound: Fushimi Pharmaceutical Co., Ltd. "FP-100" Flame retardant 2: Zinc oxide supported on zinc molybdate: Huber "KEMGARD-911B" (ion trapping agent) Hydrotalcite compound: Kyowa Chemical Industry Co., Ltd. "DHT-4A-2"

[0051] [Examples 1 and 2, Comparative Example 1] The above components were blended according to the composition (parts by mass) shown in Table 1, and the components were melt-mixed, cooled, and pulverized to obtain compositions. Each of the resulting compositions was evaluated according to the methods shown below, and the results are shown in Table 1.

[0052] (melt viscosity) The minimum melt viscosity was measured using a high-temperature flow tester (Shimadzu Corporation, CFT-100D) set at 175°C and a load of 10 kg.

[0053] (Spiral Flow) Using a mold conforming to EMMI standards, molding temperature 175°C, molding pressure 6.9N / mm 2 The measurement was carried out under the condition of a molding time of 180 seconds.

[0054] (thermal conductivity) Test pieces with a diameter of 50 mm and a thickness of 3 mm were prepared under conditions of a molding time of 180 seconds at 175°C and a molding pressure of 6.9 MPa. The test pieces were post-cured at 180°C for 4 hours, and then their thermal conductivity was measured using a steady-state thermal conductivity measuring device (GH-1, manufactured by ULVAC-RIKO, Inc.).

[0055] (breakdown voltage) Test pieces with a diameter of 90 mm and a thickness of 1 mm were prepared under conditions of 175°C for 180 seconds under a molding pressure of 6.9 MPa, and the test pieces were post-cured at 180°C for 4 hours, after which the breakdown voltage was measured in accordance with the method described in JIS C 2110-1:2010.

[0056] (adhesion strength) Using a copper frame, a truncated cone-shaped test piece with an upper diameter of 3 mm, a lower diameter of 3.568 mm, and a height of 3 mm was prepared by molding at 175°C for 2 minutes. The obtained test piece was post-cured at 180°C for 4 hours, and the shear adhesive strength was measured. Eight test pieces were measured, and the average value was taken as the adhesive strength.

[0057] (flexural modulus) The resin composition was poured into a mold conforming to JIS K 6911:2006, and test specimens were prepared under conditions of 175°C for 180 seconds at a molding pressure of 6.9 MPa, and the test specimens were post-cured for 4 hours at 180°C. The flexural modulus of the obtained test specimens was measured at room temperature (25°C) according to JIS K 6911:2006.

[0058] (Fracture toughness value K 1C ) According to ASTM E399, each composition was transfer molded at 175°C for 120 seconds under a molding pressure of 6.9 MPa, and then post-cured at 180°C for 4 hours to prepare three-point bending test specimens with notches as shown in Figure 1 (oblique view) and Figure 2 (partially enlarged view). A fracture test was performed on the test specimens at 250°C using an autograph, and the fracture toughness value (K) was calculated from the fracture strength (Pc) using the following formula: 1C ) was calculated.

number

[0059] (Weight change when left at high temperature) Each composition was transfer molded at 175°C for 120 seconds under a molding pressure of 6.9 MPa, and then post-cured at 180°C for 4 hours to obtain test specimens measuring 10 mm x 100 mm x 4 mm thick. The test specimens were stored in a 250°C oven for 336 hours. The weight loss (%) due to storage was measured based on the weight of the test specimen before storage.

[0060] (Temperature cycle test) The wire-bonded chip was sealed and subjected to a temperature cycle test under the following conditions. [Test conditions] A 100-pin QFP leadframe made of Cu alloy (Olin C7025) with a 6mm x 6mm chip, Ablestick 84-1LMI-SR4 DA agent, and an 8mm x 8mm die pad and Ag-plated wire bonding area was transfer molded with each composition at 175°C for 120 seconds under a molding pressure of 6.9 MPa, followed by post-curing at 180°C for 4 hours. The tie bars were then cut with a leadframe cutter to obtain a 20mm x 14mm x 2.7mm thick QFP package. This package underwent a temperature cycle test of 30 minutes at -50°C and 30 minutes at 150°C for 500 cycles, and the package was observed for cracking. A mark of "○" was given for no cracks, and a mark of "×" was given for cracks. If under these conditions, no cracks occur in the resin and no wire breakage occurs, it can be confirmed that the material is suitable for use as a sealing resin for motors.

[0061] [Table 1]

[0062] As described above, the encapsulating composition of the present invention has excellent toughness, low elastic modulus, and thermal conductivity while maintaining fluidity and electrical properties, and is therefore suitable as an encapsulating resin for high-power motors that require high heat dissipation properties. [Explanation of symbols]

[0063] S: Distance between supports a: Length of notch B: Test piece width W: Test piece thickness

Claims

1. A resin composition for sealing a part or all of the components constituting a motor, the resin composition for sealing a motor comprising the following (A) to (E): (A) Epoxy resin: 20 to 60 parts by mass per 100 parts by mass of the total of the (A) component, the (B) component and the (C) component described below (B) A hydrosilylation reaction product of an alkenyl group-containing epoxy compound with any one of organopolysiloxanes having one or more hydrosilyl groups per molecule and represented by the following formulas (1) to (3): 2 to 25 parts by mass per 100 parts by mass of the total of components (A), (B), and (C) described below. 【Chemistry 1】 (In formula (1), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 2 are independently a group represented by the following formula (1'): 1 is a number from 5 to 200, and n 2 is a number from 0 to 2, and n 3 is a number from 0 to 10, and n 4 is 0 or 1. 1 At least one of is a hydrogen atom. 【Chemistry 2】 (In formula (1'), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, and n 5 is a number between 1 and 10.) 【Transformation 3】 (In formula (2), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, n 6 is a number from 1 to 10, and n 7 is 1 or 2. 6 +n 7 is a number between 3 and 12.) 【Chemistry 4】 (In formula (3), R is independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, and R 1 are independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, r is a number from 0 to 3, and R 3 is a hydrogen atom or one or more groups selected from alkyl groups having 1 to 10 carbon atoms and alkoxyalkyl groups having 2 to 10 carbon atoms, and R 1 and R 3 At least one of these is a hydrogen atom.) (C) Phenol-based curing agent: 20 to 50 parts by mass per 100 parts by mass of the total of components (A), (B), and (C) (D) Black pigment: 0.5 parts by mass or more of the component (D) per 100 parts by mass of the total of the components (A), (B), and (C). (E) Inorganic filler (excluding (D) black pigment): 100 to 2,000 parts by mass per 100 parts by mass of the total of components (A), (B), and (C).

2. 2. The motor sealing resin composition according to claim 1, wherein the inorganic filler (E) comprises at least one selected from the group consisting of alumina, aluminum nitride, boron nitride, magnesium oxide, silicon carbide, silicon nitride, and diamond.

3. 2. The resin composition for sealing a motor according to claim 1, wherein the inorganic filler (E) has a volume average particle size of 3 to 40 μm.

4. 2. The resin composition for sealing a motor according to claim 1, wherein the epoxy resin (A) comprises at least one selected from the group consisting of novolac epoxy resins, aralkyl epoxy resins, and crystalline epoxy resins.

5. 2. The motor sealing resin composition according to claim 1, wherein the motor component is a rotor.

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