Thermocurable resin composition and use thereof

Abstract

Provided is a thermosetting resin composition which forms a cured product having high strength, long-term heat resistance and tracking resistance. The thermosetting resin composition comprises (A) an aliphatic bis-citraconomide compound represented by the following formula (1) (in the formula (1), A is a divalent aliphatic hydrocarbon group having 2-12 carbon atoms. ) and (B) an epoxy resin having two or more epoxy groups in one molecule, the component (A) being 20-95 mass% relative to the total of the component (A) and the component (B).

Description

Technical Field

[0001] This invention relates to thermosetting resin cured products suitable for sealing materials for power semiconductors and their use. Background Technology

[0002] Compared to previous Si power semiconductors, SiC power semiconductors have attracted much attention due to their ability to achieve higher power efficiency and smaller device size. In particular, recent years have seen further increases in power density in known devices, with chip temperatures exceeding 200°C during operation. Consequently, there is a strong desire to develop sealing materials that possess long-term heat resistance at 200°C and excellent resistance to tracking with a relatively high coefficient of performance (CTI).

[0003] Firstly, regarding long-term heat resistance at 200°C, Patent Documents 1 and 2 report that resin compositions containing maleimide-based resins exhibit excellent heat resistance, with glass transition temperatures (Tg) exceeding 300°C and 5% weight loss temperatures (Td5) exceeding 400°C. This is presumably due to the rigidity of the aromatic ring components in the structure of all the aforementioned resins, as well as the high crosslinking density characteristic of maleimide-based resins.

[0004] Next, regarding resistance to tracking, patent documents 3 and 4 report the introduction of alicyclic structures into the epoxy resin structure, which achieves excellent resistance to tracking. This is presumably due to the reduction of the proportion of aromatic rings in the structure, thereby suppressing the formation of carbonized conductive paths, which are the cause of tracking.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2015-193628

[0008] Patent Document 2: Japanese Patent Application Publication No. 2019-064926

[0009] Patent Document 3: Japanese Patent Application Publication No. 2005-213299

[0010] Patent Document 4: Japanese Patent Application Publication No. 2023-019588 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, resin compositions containing maleimide-based resins with high heat resistance have poor tracking resistance, while resin compositions containing epoxy resins with tracking resistance have poor heat resistance.

[0013] Therefore, the object of the present invention is to provide a thermosetting resin composition that can form a cured product with high strength, long-term heat resistance and resistance to tracking, and a sealing material for semiconductors manufactured using the thermosetting resin composition.

[0014] Methods for solving problems

[0015] In order to achieve the above objectives, the inventors conducted repeated and in-depth research and discovered that the following thermosetting resin composition can achieve the above objectives, thus completing the present invention. That is, the present invention provides the following thermosetting resin composition.

[0016] [1] A thermosetting resin composition comprising:

[0017] (A) An aliphatic bisciconimide compound represented by the following formula (1),

[0018]

Chemistry 1

[0019]

[0020] (In formula (1), A is a divalent aliphatic hydrocarbon group with 2 to 12 carbon atoms.) and

[0021] (B) Epoxy resins having two or more epoxy groups in one molecule.

[0022] Component (A) comprises 20-95% by mass relative to the total of components (A) and (B).

[0023] [2] According to the thermosetting resin composition of [1], wherein, in the formula (1), A is a divalent chain aliphatic hydrocarbon group with 2 to 12 carbon atoms.

[0024] [3] The thermosetting resin composition according to [1] or [2] further comprises (C) a curing accelerator.

[0025] [4] The thermosetting resin composition according to [3], wherein the (C) component comprises one or more selected from imidazole curing accelerators, organophosphorus curing accelerators and tertiary amine curing accelerators.

[0026] [5] A sealing material for semiconductors, comprising a thermosetting resin composition according to any one of [1] to [4].

[0027] [6] The sealing material for semiconductors according to [5], wherein the semiconductor is a power semiconductor.

[0028] The effects of the invention

[0029] The cured product of the thermosetting resin composition of the present invention has high strength, long-term heat resistance, and resistance to tracking. Therefore, the composition of the present invention can be used in sealing materials for semiconductors, particularly for sealing materials for power semiconductors that require high-strength resins, long-term heat resistance at high temperatures, and resistance to tracking at 600V or higher. Detailed Implementation

[0030] [(A) Aliphatic bisacodylimide compound]

[0031] The component (A) used in this invention is an aliphatic bis-citronimid compound represented by the following formula (1).

[0032]

Chemistry 2

[0033]

[0034] In formula (1) above, A is a divalent aliphatic hydrocarbon group with 2 to 12 carbon atoms, preferably 6 to 9. The aliphatic hydrocarbon group represented by A can be any of the following: linear, branched, or cyclic.

[0035] There are no particular limitations on the properties and number-average molecular weight of the aliphatic bisciconimide compound of component (A) at room temperature (25℃±10℃), but the number-average molecular weight is preferably 100 to 10000, more preferably 100 to 5000, and even more preferably 100 to 1000.

[0036] In this specification, the number-average molecular weight is the number-average molecular weight converted to polystyrene standard obtained by gel permeation chromatography (GPC) using the following determination conditions.

[0037] [GPC Measurement Conditions]

[0038] Elution solvent: Tetrahydrofuran (THF)

[0039] Flow rate: 0.35 mL / min

[0040] Detector: Differential Refractive Index Detector (RI)

[0041] Column: TSK Guardcolumn SuperH-L

[0042] TSKgelSuperHZ4000(4.6mmI.D.×15cm×1)

[0043] TSKgelSuperHZ3000(4.6mmI.D.×15cm×1)

[0044] TSKgelSuperHZ2000(4.6mmI.D.×15cm×2)

[0045] (All are manufactured by Tosoh Corporation)

[0046] Column temperature: 40℃

[0047] Sample injection volume: 5 μL (0.2% by mass THF solution)

[0048] (A) The aliphatic bis-citronimid compound of component (A) can be used alone or in combination of two or more.

[0049] In the composition of the present invention, the proportion of component (A) relative to the total 100% by mass of components (A) and (B) is 20 to 95% by mass, preferably 50 to 95% by mass. If the ratio of component (A) to component (B) is within this range, a crack-free cured product is readily obtained.

[0050] Furthermore, in the composition of the present invention, the combined amount of component (A) and component (B) is preferably 45 to 100% by mass, more preferably 50 to 99% by mass.

[0051] [(B) Epoxy Resin]

[0052] (B) epoxy resin is added for the purpose of promoting the reaction of (A) aliphatic bis(citric acid)imide compound and for maintaining the shape of the cured product.

[0053] This epoxy resin has more than two epoxy groups in one molecule, and can use conventionally known epoxy resins.

[0054] Examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, and other bisphenol-type epoxy resins; phenolic varnish type epoxy resins such as phenol, cresol, bisphenol A, and bisphenol F; alicyclic epoxy resins such as dicyclopentadiene type epoxy resin and 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexene carboxylate; and isophenylene oxide. Multifunctional phenolic epoxy resins such as resorcinol-type epoxy resins and phenolic varnish-type epoxy resins; stilbene-type epoxy resins, epoxy resins containing triazine skeletons, epoxy resins containing fluorene skeletons, triphenol alkane-type epoxy resins, biphenyl-type epoxy resins, xylene-type epoxy resins, biphenyl aralkyl-type epoxy resins, naphthalene-type epoxy resins, and anthracene and other polycyclic aromatic glycidyl ether compounds, as well as phosphorus-containing epoxy resins in which phosphorus compounds have been introduced, etc.

[0055] Among them, epoxy resins with cyclic saturated hydrocarbon groups in their molecules have better resistance to tracking and are therefore preferred.

[0056] They can be used individually or in combination of two or more.

[0057] In the composition of the present invention, the proportion of component (B) relative to the total 100% by mass of components (A) and (B) is 5 to 80% by mass, preferably 5 to 50% by mass. If the ratio of component (A) to component (B) is within this range, a crack-free cured product is readily obtained.

[0058] [(C) Curing Accelerator]

[0059] (C) The curing accelerator is an optional component formulated to promote the curing of the above-mentioned (A) aliphatic biscitanimide compound. Commonly known curing accelerators, such as imidazole curing accelerators, organophosphorus curing accelerators, tertiary amine curing accelerators, etc., can be used.

[0060] Examples of organophosphorus curing accelerators include triphenylphosphine, tributylphosphine, tris(p-methylphenyl)phosphine, tris(nonylphenyl)phosphine, etc.; phosphine-borane complexes such as triphenylphosphine-triphenylborane; phosphine borates such as tetraphenylphosphine tetraphenylborate, tetraphenylphosphine tetra-p-tolylborate, p-tolyltriphenylphosphine tetra-p-tolylborate, tri-tert-butylphosphine tetraphenylborate, etc.; and bis(tetrabutylphosphine)dihydropyromellitictetrate, etc.

[0061] Examples of tertiary amine curing accelerators include triethylamine, benzyl dimethylamine, α-methylbenzyl dimethylamine, 1,8-diazabicyclo[5.4.0]undecene-7, and salts of tertiary amine compounds such as 1,8-diazabicyclo[5.4.0]undecene-7.

[0062] Examples of imidazole-based curing accelerators include 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, and 2-phenyl-4-methylimidazole.

[0063] (C) Components may be used alone or in combination of two or more.

[0064] Regarding the amount of curing accelerator (C), in order to promote curing, it is preferably 0.01 to 10 parts by mass relative to the total of 100 parts by mass of components (A) and (B), and more preferably 1 to 5 parts by mass.

[0065] [Other Additives]

[0066] In addition to the components (A) to (C) mentioned above, other additives may be added to the thermosetting resin composition of the present invention as needed, without impairing the purpose or effect of the present invention. Examples of such additives include inorganic fillers, flame retardants, ion traps, antioxidants, adhesive agents, stress reducers, and colorants.

[0067] Inorganic fillers are formulated to improve the resin strength and reduce thermal expansion of thermosetting resin compositions. Examples of inorganic fillers include silica-based materials (e.g., fused silica, crystalline silica, brittle mica, etc.), alumina, silicon nitride, aluminum nitride, boron nitride, titanium oxide, glass fiber, and magnesium oxide. The average particle size and shape of these inorganic fillers can be selected according to the application.

[0068] Regarding inorganic filler materials, to enhance the bonding strength between the resin and the inorganic filler material, it is preferable to use inorganic filler materials that have undergone surface treatment with coupling agents such as silane coupling agents or titanate coupling agents. Examples of such coupling agents include epoxy silanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; amino silanes such as N-β(aminoethyl)-γ-aminopropyltrimethoxysilane, the reaction product of imidazole and γ-glycidoxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane; and silane coupling agents such as γ-mercaptosilane and γ-cyclothiopropyltrimethoxysilane. Furthermore, there are no particular limitations on the mixing amount of the coupling agent used in the surface treatment or the surface treatment method.

[0069] The amount of inorganic filler material mixed is preferably 10 to 20,000 parts by mass relative to the total of 100 parts by mass of components (A) and (B), and more preferably 30 to 10,000 parts by mass.

[0070] Flame retardants are added for the purpose of imparting flame retardancy. There are no particular restrictions on the flame retardant used; any known flame retardant may be used, such as phosphazene compounds, organosilicon compounds, zinc molybdate-supported talc, zinc molybdate-supported zinc oxide, aluminum hydroxide, magnesium hydroxide, and molybdenum oxide.

[0071] Ion traps are added to capture ionic impurities in resin compositions and to prevent thermal and hygroscopic degradation. There are no particular limitations on the ion trap; any known ion trap can be used, such as hydrotalcite, bismuth hydroxide compounds, and rare earth oxides.

[0072] There are no particular limitations on its use as an antioxidant; examples include octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)acetate, neododecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, dodecyl-β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, ethyl-α-(4-hydroxy-3,5-di-tert-butylphenyl)isobutyrate, octadecyl-α-(4-hydroxy-3,5-di-tert-butylphenyl)isobutyrate, and octadecyl-α-(4-hydroxy-3,5-di-tert-butylphenyl)isobutyrate. 2-(n-octylthio)ethyl-3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-(n-octylthio)ethyl-3,5-di-tert-butyl-4-hydroxyphenyl acetate, 2-(n-octadecylthio)ethyl-3,5-di-tert-butyl-4-hydroxyphenyl acetate, 2-(n-octadecylthio)ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 2-(2-stearoyloxyethylthio)ethyl-7-(3-methyl-5-tert-butyl-4-hydroxyphenyl)heptanoate, 2-hydroxyethyl-7-(3-methyl-5-tert-butyl-4-hydroxyphenyl)propionate Phenolic antioxidants such as pentaerythritol tetra[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]; sulfur-based antioxidants such as dilauryl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearate-3,3'-thiodipropionate, di(tetranyl)-3,3'-thiodipropionate, pentaerythritol tetra(3-dodecyl thiopropionate); tridecyl phosphite, triphenyl phosphite, tris(2,4-di-tert-butylphenyl) phosphite, 2-ethylhexyl diphenyl phosphite, diphenyltridecyl phosphite, 2, Phosphorus-based antioxidants include 2-methylene bis(4,6-di-tert-butylphenyl)octyl phosphite, distearate pentaerythritol diphosphite, bis(2,6-di-tert-butyl-4-methylphenyl) pentaerythritol diphosphite, and 2-[[2,4,8,10-tetra(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphanecyclohepten-6-yl]oxy]-N,N-bis[2-[[2,4,8,10-tetra(1,1-dimethylethyl)dibenzo[d,f][1,3,2]dioxaphosphanecyclohepten-6-yl]oxy]-ethyl]ethylamine.

[0073] As an adhesive agent, there is no particular limitation as long as it is a known adhesive agent and produces the effect of the present invention. An adhesive agent may be included as needed to impart adhesiveness or pressure-sensitive adhesion. Examples of adhesive agents include polyurethane resins, phenolic resins, terpene resins, and silane coupling agents. Among these, silane coupling agents are preferred for imparting adhesiveness.

[0074] There are no particular limitations on silane coupling agents. Examples include n-propyltrimethoxysilane, n-propyltriethoxysilane, n-octyltrimethoxysilane, n-octyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, 2-[methoxy(polyethyleneoxy)propyl]-trimethoxysilane, methoxytri(ethyleneoxy)propyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-(methacryloyloxy)propyltrimethoxysilane, 3-isocyanate-propyltriethoxysilane, 3-isocyanate-propyltrimethoxysilane, etc.

[0075] The amount of other additives varies depending on the purpose of the composition, and is generally less than 5% by mass of the total composition excluding inorganic fillers.

[0076] [Method for manufacturing the composition]

[0077] The thermosetting resin composition of the present invention can be manufactured by the method shown below. For example, a mixture of components (A) and (B) is obtained by simultaneously or separately subjecting them to heat treatment as needed, followed by mixing, stirring, dissolving, and / or dispersing. If necessary, a mixture of components (A) to (C) can be obtained by adding curing accelerator (C) to the mixture of components (A) and (B), followed by stirring, dissolving, and / or dispersing. Furthermore, depending on the intended use, at least one of inorganic fillers, flame retardants, polymerization initiators, and ion trapping agents can be added to and mixed into the mixture of components (A) to (C). Each component can be used alone or in combination of two or more.

[0078] In the method of manufacturing the composition, there are no particular limitations on the apparatus used for mixing, stirring, and dispersing. Specifically, for example, a pulverizer, two-roll mill, three-roll mill, ball mill, planetary mixer, or Mass Colloider equipped with stirring and heating devices can be used, and these devices can be appropriately combined.

[0079] [use]

[0080] The thermosetting resin composition of the present invention is suitable for use as an adhesive and semiconductor sealing material because it can form a cured product with excellent resistance to tracking (CTI≥600V) and high heat resistance.

[0081] When used as a semiconductor sealing material, it is preferable to mix the components in a specified ratio as described above, mix them thoroughly and evenly using a mixer or the like, then melt-mix them using a hot roller, kneader, extruder, or the like, and then cool and solidify them before crushing them into appropriate sizes.

[0082] Common molding methods for semiconductor sealing materials include transfer molding and compression molding. In transfer molding, a transfer molding machine is used, with a molding pressure of 5–20 N / mm². 2 The molding process can be performed at a molding temperature of 120–190°C for a molding time of 30–500 seconds, preferably at a molding temperature of 150–185°C for a molding time of 30–180 seconds. Alternatively, in compression molding, a compression molding machine can be used, with a molding temperature of 120–190°C and a molding time of 30–600 seconds, preferably at a molding temperature of 130–160°C for a molding time of 120–300 seconds. Furthermore, in all molding methods, post-curing can be performed at 150–225°C for 0.5–20 hours.

[0083] Example

[0084] The following examples and comparative examples illustrate the invention in detail, but the invention is not limited to the examples described below. It should be noted that, hereinafter, the number-average molecular weight (Mn) is determined using gel permeation chromatography (GPC) with polystyrene as a reference under the conditions described below. Additionally, in the following formulas, Me represents methyl.

[0085] [GPC Measurement Conditions]

[0086] Elution solvent: Tetrahydrofuran (THF)

[0087] Flow rate: 0.35 mL / min

[0088] Detector: Differential Refractive Index Detector (RI)

[0089] Column: TSK Guardcolumn SuperH-L

[0090] TSKgel SuperHZ4000(4.6mmI.D.×15cm×1)

[0091] TSKgel SuperHZ3000(4.6mmI.D.×15cm×1)

[0092] TSKgel SuperHZ2000(4.6mmI.D.×15cm×2)

[0093] (All are manufactured by Tosoh Corporation)

[0094] Column temperature: 40℃

[0095] Sample injection volume: 5 μL (0.2% by mass THF solution)

[0096] (A) Aliphatic bisacodylimide compounds

[0097] [Synthesis example 1]

[0098] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 60.10 g (1.0 mol) of ethylenediamine, 235.37 g (2.1 mol) of citral anhydride, 600 g of toluene, and 257 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 96.10 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 300 g of deionized water. Then, precipitation was performed using heptane, and the mixture was filtered to obtain 65.13 g (26% yield) of the target compound ((A-1), Mn148, melting point 140°C) as a yellow solid at room temperature.

[0099]

Transformation 3

[0100]

[0101] [Synthesis example 2]

[0102] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 88.21 g (1.0 mol) of tetramethylenediamine, 235.37 g (2.1 mol) of citral anhydride, 600 g of toluene, and 257 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 96.10 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 300 g of deionized water. Then, precipitation was performed using heptane, and the mixture was filtered to obtain 124.8 g (45% yield) of the target compound ((A-2), Mn2O8, melting point 120°C) as a yellow solid at room temperature.

[0103]

Chemistry 4

[0104]

[0105] [Synthesis example 3]

[0106] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 116.20 g (1.0 mol) of hexamethylenediamine, 235.37 g (2.1 mol) of citral anhydride, 600 g of toluene, and 257 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 96.10 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While distilling off the byproduct water, the mixture was stirred for 16 hours. The reaction solution was then washed five times with 300 g of deionized water. Precipitation was then performed using heptane, and the mixture was filtered to obtain 157.57 g (52% yield) of the target compound ((A-3), Mn262, melting point 110°C) as a yellow solid at room temperature.

[0107]

Transformation 5

[0108]

[0109] [Synthesis Example 4]

[0110] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 158.28 g (1.0 mol) of 1,9-nonanediamine, 235.37 g (2.1 mol) of citralic anhydride, 600 g of toluene, and 257 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 96.10 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 300 g of deionized water. Then, precipitation was performed using heptane, and the mixture was filtered to obtain 245.97 g (71%) of the target compound ((A-4), Mn354, melting point 49°C) as a yellow solid at room temperature.

[0111]

Transformation 6

[0112]

[0113] [Synthesis example 5]

[0114] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 200.37 g (1.0 mol) of 1,12-dodecanediamine, 235.37 g (1.0 mol) of citralic anhydride, 600 g of toluene, and 257 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 96.10 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 200 g of deionized water. Then, the solution was stripped under reduced pressure at 60°C to obtain 355.4 g (91% yield) of the target compound ((A-5), Mn449, melting point 72°C) as a brown liquid at room temperature.

[0115]

Transformation 7

[0116]

[0117] [Synthesis example 6]

[0118] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 71.2 g (0.45 mol) of trimethylhexanediamine (a mixture of 2,2,4-trimethylhexanediamine and 2,4,4-trimethylhexanediamine), 111.0 g (0.99 mol) of citrate anhydride, and 150 g of toluene were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 40 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 200 g of deionized water. Then, the solution was stripped under reduced pressure at 60°C to obtain 149.7 g (96% yield) of the target compound ((A-6), Mn590) as a brown liquid at room temperature.

[0119]

Transformation 8

[0120]

[0121] [Comparative Synthesis Example 1]

[0122] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 176.67 g (2.0 mol) of 1,4-butanediamine, 411.85 g (4.2 mol) of maleic anhydride, 870 g of toluene, and 870 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80 °C for 3 hours to synthesize amyl acid. Then, 192.25 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110 °C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 500 g of deionized water. Then, precipitation was performed using heptane, and the mixture was filtered to obtain 348.84 g (70% yield) of the target compound ((A'-1), Mn2O5, melting point 202 °C) as a white solid at room temperature.

[0123]

Chemistry 9

[0124]

[0125] [Comparative Synthesis Example 2]

[0126] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 232.42 g (2.0 mol) of hexamethylenediamine, 411.85 g (4.2 mol) of maleic anhydride, 1200 g of toluene, and 514 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 192.20 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 500 g of deionized water. Then, precipitation was performed using heptane, and the mixture was filtered to obtain 357.92 g (65% yield) of the target compound ((A'-2), Mn253, melting point 143°C) as a white solid at room temperature.

[0127]

Chemistry 10

[0128]

[0129] [Comparative Synthesis Example 3]

[0130] In a 2L four-necked glass flask equipped with a stirrer, Dean-Stark tube, condenser, and thermometer, 158.35 g (1.0 mol) of trimethylhexanediamine (a mixture of 2,2,4-trimethylhexanediamine and 2,4,4-trimethylhexanediamine), 205.94 g (2.1 mol) of maleic anhydride, 600 g of toluene, and 257 g of N-methyl-2-pyrrolidone were added to prepare a reaction solution. The solution was stirred at 80°C for 3 hours to synthesize amyl acid. Then, 96.10 g of methanesulfonic acid was added to the reaction solution, and the temperature was raised to 110°C. While stirring for 16 hours to remove the byproduct water, the reaction solution was washed five times with 300 g of deionized water. Then, precipitation was performed using heptane, and the mixture was filtered to obtain 237.81 g (75% yield) of the target compound ((A'-3), Mn318, melting point 88°C) as a white solid at room temperature.

[0131]

Chemistry 11

[0132]

[0133] (B) Epoxy resin

[0134] (B-1) Dicyclopentadiene type epoxy resin (trade name: HP-7200: manufactured by DIC Co., Ltd., softening point 57℃, epoxy equivalent 259)

[0135] (C) Curing accelerator

[0136] (C-1)2-Ethyl-4-methylimidazolium (trade names: 2E4MZ, manufactured by SHIKOKU KASEI HOLDINGSCORPORATION)

[0137] [Examples 1-9 and Comparative Examples 1-3]

[0138] The above-mentioned components were mixed in the proportions (parts by mass) listed in Table 1, cast in a mold, and cured in stages at 180°C for 1 hour and then at 230°C for 2 hours to obtain a thermosetting resin composition. The obtained resin composition was evaluated as described below. The results are shown in Table 1. Furthermore, the (A'-1) bismaleimide compound shown in Comparative Example 1 of Table 1 has a melting point near the temperature range where the curing reaction occurs (approximately 200°C). Therefore, during the mixing of the components, the melting and curing reactions of the (A'-1) bismaleimide compound occurred simultaneously, and a homogeneous cured product was not obtained.

[0139] Furthermore, in Table 1, "BCI compound" refers to bis-citronimid compound, and "BMI compound" refers to bismaleimide compound.

[0140] <Critical Tracking Indication (CTI) Measurement>

[0141] The above components were mixed in the proportions (parts by mass) listed in Table 1, cast in a mold, and cured in stages at 180°C for 1 hour and then at 230°C for 2 hours to obtain a 3 mm thick, 50 mm diameter disc-shaped cured material. Using this cured material, tracking resistance was tested according to the method of JIS C 2134:2021 (IEC 60112). The maximum voltage that did not damage the cured material even when more than 50 drops of a 0.1% ammonium chloride aqueous solution were added, in an evaluation with n=5 tests, was measured. It should be noted that 600V is considered an upper limit.

[0142] <Determination of Weight Reduction Rate During Storage at 200℃>

[0143] The above components were mixed in the proportions (parts by mass) listed in Table 1, cast in a mold, and cured in stages at 180°C for 1 hour and then at 230°C for 2 hours to obtain a cured thermosetting resin composition. Using this cured composition, the weight was measured before and after standing in a 200°C dryer for one week, and the weight loss at 200°C was calculated.

[0144] <Bending Strength Test>

[0145] The above components were mixed according to the proportions (parts by mass) listed in Table 1, molded, and then cured in stages at 180°C for 1 hour and then at 230°C for 2 hours to obtain a test piece of 100×10×4mm thickness. The test piece was subjected to a 3-point bending test using an Autograph manufactured by Shimadzu Corporation according to JIS K 6911:2006, and the bending strength was calculated.

[0146] Table 1

[0147]

[0148] Judging from the results in Table 1, compared with the resin compositions containing aliphatic bismaleimide compounds in Comparative Examples 1-3, the resin compositions in Examples 1-9 containing aliphatic bismaleimide compounds all exhibited superior anti-tracking properties and long-term heat resistance at 200°C.

Claims

1. A thermosetting resin composition comprising: (A) an aliphatic bis-citraconimide compound represented by the following formula (1), 【Chem. 1】 In the formula (1), A is a divalent aliphatic hydrocarbon group having 2 to 12 carbon atoms, and (B) an epoxy resin having two or more epoxy groups in one molecule, The (A) component is 20 to 95 mass% relative to the total of the (A) component and the (B) component.

2. The thermosetting resin composition according to claim 1, wherein, In the formula (1), A is a divalent chain aliphatic hydrocarbon group having 2 to 12 carbon atoms.

3. The thermosetting resin composition according to claim 1, further comprising (C) a curing accelerator.

4. The thermosetting resin composition according to claim 3, wherein, The (C) component comprises one or more selected from the group consisting of an imidazole-based curing accelerator, an organic phosphorus-based curing accelerator, and a tertiary amine-based curing accelerator.

5. A sealing material for a semiconductor composed of the thermosetting resin composition according to any one of claims 1 to 4.

6. The sealing material for a semiconductor according to claim 5, wherein The semiconductor is a power semiconductor.

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