# US 2025/0019489 A1 · Thermosetting resin composition, thermally conductive resin sheet, heat-dissipating layered product, heat-dissipating circuit board, semiconductor device and power module > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0019489 A1 - Document ID: US20250019489A1 - Status: Published application - Kind: A1 - Application number: 18/891,001 - Filed: 2024-09-20 - Published: 2025-01-16 - Earliest claimed: 2022-03-24 - Assignees: Mitsubishi Chemical Corporation - Applicants: Mitsubishi Chemical Corporation - Inventors: Toshiyuki TANAKA; Sae TANIGUCHI; Toshiyuki SAWAMURA; Yumiko YAMAMOTO; Katsuhiko HIDAKA - Web page: https://patentgrep.com/patent/US20250019489A1 ## CPC - C08G 59/32: Epoxy compounds containing three or more epoxy groups - C08G 59/38: together with di-epoxy compounds - C08G 59/5046: {heterocyclic} - C08G 59/686: {containing nitrogen} - C08J 3/247: {Heating methods} - C08J 7/0427: {with only one layer of a composition containing a polymer binder (with more layers C08J7/042)} - C08K 3/22: of metals - C08K 7/18: inorganic - H05K 1/0373: {containing additives, e.g. fillers (H05K1/036 takes precedence)} - C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins - C08J 2371/00: Characterised by the use of polyethers obtained by reactions forming an ether link in the main chain; Derivatives of such polymers - C08J 2467/06: Unsaturated polyesters - C08K 2003/2227: {of aluminium} - C08K 2003/282: {Binary compounds of nitrogen with aluminium} - C08K 2003/385: {Binary compounds of nitrogen with boron} - C08K 2201/005: Additives being defined by their particle size in general - C08L 2205/03: containing three or more polymers in a blend - H05K 2201/0209: Inorganic, non-metallic particles - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C08J: WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H (working, e.g. shaping, of plastics B29) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract A thermosetting resin composition containing a thermosetting resin, an inorganic filler, and a polymer having a mass average molecular weight of 10,000 or more, wherein the thermosetting resin composition includes boron nitride agglomerated particles as the inorganic filler, and includes an epoxy compound and a benzoxazine compound as the thermosetting resin, and a ratio of a mass content of the boron nitride agglomerated particles to a mass content of the benzoxazine compound (boron nitride agglomerated particles/benzoxazine) is 5 or more and 50 or less, a thermally conductive sheet having thermal conductivity and heat resistance can be formed. In addition, the thermosetting resin composition can be formed into a film without any problem when forming a sheet, and sufficient adhesive strength can be obtained when cured. ## Claims ### Claim 1 A thermosetting resin composition, comprising: a thermosetting resin comprising an epoxy compound and a benzoxazine compound; an inorganic filler comprising agglomerated particles comprising boron nitride; and a polymer having a mass average molecular weight of 10,000 or more, wherein an agglomerated particles/benzoxazine mass mass ratio of the agglomerated particles to the benzoxazine compound is 5 or more and 50 or less. ### Claim 2 (depends on 1) The thermosetting resin composition of claim 1, wherein the benzoxazine compound is solid at 25° C. ### Claim 3 A thermosetting resin composition, comprising: a thermosetting resin comprising an epoxy compound and a benzoxazine compound that is liquid at 25° C.; and an inorganic filler comprising agglomerated particles comprising boron nitride. ### Claim 4 (depends on 3) The thermosetting resin composition of claim 3, further comprising: a polymer having a mass average molecular weight of 10,000 or more. ### Claim 5 (depends on 3) The thermosetting resin composition of claim 3, wherein an agglomerated particles/benzoxazine mass ratio of the agglomerated particles to the benzoxazine compound is 50 or less. ### Claim 6 (depends on 1) The thermosetting resin composition of claim 1, comprising the agglomerated particles in a range of from 50 to 85% by mass, with respect to 100% by mass of a total solid content of the thermosetting resin composition. ### Claim 7 (depends on 1) The thermosetting resin composition of claim 1, wherein the polymer having a mass average molecular weight of 10,000 or more comprises a functional group that reacts with the epoxy compound. ### Claim 8 (depends on 1) The thermosetting resin composition of claim 1, comprising the polymer having a mass average molecular weight of 10,000 or more in a range of from 10 to less than 30% by mass, with respect to 100% by mass of a solid content of the thermosetting resin composition, excluding the inorganic filler. ### Claim 9 (depends on 1) The thermosetting resin composition of claim 1, wherein a benzoxazine compound/epoxy compound mass ratio of the benzoxazine compound to the epoxy compound as solid content of the thermosetting resin excluding the inorganic filler is less than 0.8. ### Claim 10 (depends on 1) The thermosetting resin composition of claim 1, further comprising: a curing catalyst comprising an imidazole compound. ### Claim 11 (depends on 1) The thermosetting resin composition of claim 1, wherein the epoxy compound of the thermosetting resin comprises a polyfunctional epoxy compound having three or more epoxy groups per molecule and having a molecular weight of 650 or less. ### Claim 12 (depends on 11) The thermosetting resin composition of claim 11, wherein the polyfunctional epoxy compound is an epoxy compound having four or more glycidyl groups in one molecule. ### Claim 13 (depends on 1) A thermosetting resin sheet, formed from the thermosetting resin composition of claim 1. ### Claim 14 (depends on 13) A thermally conductive resin sheet, comprising, in cured form, the thermosetting resin sheet of claim 13. ### Claim 15 A thermally conductive resin sheet, comprising: a cured product of a thermosetting resin composition comprising a thermosetting resin comprising an epoxy compound and a benzoxazine compound, and an inorganic filler comprising agglomerated particles comprising boron nitride, wherein the thermally conductive resin sheet has a glass transition temperature in a range of from 160° C. to lower than 250° C. ### Claim 16 A thermally conductive resin sheet, comprising: a cured product of a thermosetting resin composition comprising a thermosetting resin comprising an epoxy compound and a benzoxazine compound, and an inorganic filler comprising agglomerated particles comprising boron nitride, wherein the thermally conductive resin sheet has an average coefficient of thermal expansion from 0° C. to 175° C. in a range of from 20 to 30 ppm. ### Claim 17 (depends on 14) The thermally conductive resin sheet of claim 14, having a thermal conductivity in the thickness direction at 25° C. of 10 W/mK or more. ### Claim 18 (depends on 14) A heat-dissipating laminated body, comprising: the thermally conductive resin sheet of claim 14. ### Claim 19 (depends on 14) A heat-dissipating circuit board, comprising: the thermally conductive resin sheet of claim 14. ### Claim 20 (depends on 19) A semiconductor device, comprising: the heat-dissipating circuit board of claim 19. ### Claim 21 (depends on 14) A power module, comprising: the thermally conductive resin sheet of claim 14.