# US 11,441,027 B2 · Epoxy resin composition, prepreg, and fiber-reinforced composite material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,441,027 B2 - Document ID: US11441027B2 - Status: Granted - Kind: B2 - Application number: 16/755,945 - Filed: 2018-09-28 - Published: 2020-08-06 - Granted: 2022-09-13 - Earliest claimed: 2017-10-24 - Assignees: Toray Industries, Inc. - Applicants: Toray Industries, Inc. - Inventors: Akihiko Ito; Hiroaki Sakata - Web page: https://patentgrep.com/patent/US11441027B2 ## CPC - C08G 59/4071: {phosphorus containing compounds} - C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins - C08G 59/245: {aromatic} - C08G 59/28: containing acyclic nitrogen atoms - C08G 59/3227: {Compounds containing acyclic nitrogen atoms} - C08G 59/38: together with di-epoxy compounds - C08G 59/4014: {Nitrogen containing compounds} - C08G 59/5033: {aromatic} - C08G 59/504: {containing an atom other than nitrogen belonging to the amine group, carbon and hydrogen} - C08J 5/04: Reinforcing macromolecular compounds with loose or coherent fibrous material - C08J 5/24: Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs - C08J 5/249: {characterised by the additives used in the prepolymer mixture} - C08K 5/5397: Phosphine oxides - C08L 81/06: Polysulfones; Polyethersulfones - C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins - C08L 2201/02: Flame or fire retardant/resistant - C08L 2205/03: containing three or more polymers in a blend - C08G: MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - 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) ## Abstract The purpose of the present invention is to provide an epoxy resin composition which has excellent viscosity stability, and when cured, can provide a resin cured product which has high flame retardancy and excellent mechanical properties, and a prepreg and fiber-reinforced composite material using the epoxy resin composition. An embodiment of the epoxy resin composition according to the present invention which achieves the purpose contains all components [A]-[C]. [A]: A reactive diluent having a specific structure and a viscosity of 2 Pa·s or less at 25° C. [B]: An epoxy resin having three of more functional groups. [C]: An amine-based curing agent having a specific structure. ## Claims ### Claim 1 An epoxy resin composition comprising: at least one reactive diluent [A] having a viscosity of 2 Pas or less at 25° C. and selected from the group consisting of a reactive diluent having a structure represented by general formula (4), a reactive diluent having a structure represented by general formula (7), and a reactive diluent having a structure represented by general formula (8); at least one trifunctional or higher functional epoxy resin [B] selected from the group consisting of N,N,O-triglycidyl-m-aminophenol, N,N,O-triglycidyl-p-aminophenol, N,N,O-triglycidyl-4-amino-3-methylphenol, N,N,N′,N′-tetraglycidyl-4,4′-methylenedianiline, N,N,N′,N′-tetraglycidyl-2,2′-diethyl-4,4′-methylenedianiline and N,N,N′,N′-tetraglycidyl-m-xylylenediamine; at least one amine-based hardener [C] selected from the group consisting of an amine-based hardener having a structure represented by general formula (2) and an amine-based hardener having a structure represented by general formula (3); optionally, a non-phosphorus-containing aromatic polyamine hardener provided in an amount of up to 90 parts by mass based on 100 parts by mass total of [C] and the aromatic polyamine hardener; and at least one thermoplastic resin [D] composed of a polyaryl ether skeleton: wherein in the general formula (4), R3 and R4 each independently represent at least one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 3 to 6, an aromatic hydrocarbon group with a carbon number of 6 to 10, a halogen atom, an acyl group, a trifluoromethyl group and a nitro group; and X3 represents one selected from the group consisting of —O—, —S—, —CO—, —C(═O)O— and —S2−; wherein in the general formula (7), R7 and R8 each independently represent at least one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 3 to 6, an aromatic hydrocarbon group with a carbon number of 6 to 10, a halogen atom, an acyl group, a trifluoromethyl group and a nitro group, with the proviso that both of R7 and R8 are not hydrogen atoms; wherein in the general formula (8), R9 and R10 each independently represent a direct bond, an alkylene group with a carbon number of 1 to 8, a phenylene group or a cyclohexylene group; and R11 represents one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 3 to 6, an aromatic hydrocarbon group with a carbon number of 6 to 10, a halogen atom, an acyl group, a trifluoromethyl group and a nitro group; wherein in the general formula (2), R1 represents a hydrocarbon group with a carbon number of 2 to 4; and in the general formula (3), R2 represents a hydrogen atom or an amino group; wherein [A] is present in an amount of 10 to 50 parts by mass and [B] is present in an amount of 50 to 90 parts by mass, totaling 100 parts by mass; and wherein [C] is present in amount to provide a phosphorus atom content of 1.0 to 5.0% by mass, based on the overall mass of the epoxy resin composition. ### Claim 2 (depends on 1) The epoxy resin composition according to claim 1, wherein [A] comprises a reactive diluent having a structure represented by general formula (4) or a reactive diluent having a structure represented by general formula (7). ### Claim 3 (depends on 1) The epoxy resin composition according to claim 1, wherein R3 and R4 of the general formula (4) is a hydrogen atom. ### Claim 4 (depends on 1) The epoxy resin composition according to claim 1, wherein at least one of R7 and R8 of the general formula (7) is a methyl group. ### Claim 5 (depends on 1) The epoxy resin composition according to claim 1, wherein [A] is selected from the group consisting of N,N-diglycidyl-4-phenoxyaniline, N,N-diglycidyl-o-toluidine, N,N-diglycidyl-m-toluidine, N,N-diglycidyl-p-toluidine, N,N-diglycidyl-2,3-xylidine, N,N-diglycidyl-2,4-xylidine, N,N-diglycidyl-3,4-xylidine, 1,4-cyclohexanedimethanol diglycidyl ether, and 1,4-cyclohexanediethanol diglycidyl ether. ### Claim 6 (depends on 1) The epoxy resin composition according to claim 1, wherein [A] is present in an amount of 20 to 40 parts by mass and [B] is present in an amount of 60 to 80 parts by mass, totaling 100 parts by mass. ### Claim 7 (depends on 1) The epoxy resin composition according to claim 1, wherein [C] comprises an amine-based hardener having a structure represented by general formula (3). ### Claim 8 (depends on 7) The epoxy resin composition according to claim 7, wherein R2 in the general formula (3) is an amino group. ### Claim 9 (depends on 1) The epoxy resin composition according to claim 1, wherein [D] comprises polyethersulfone. ### Claim 10 (depends on 9) The epoxy resin composition according to claim 9, wherein [D] is present in amount of 24 to 27 parts by mass based on the total 100 parts by mass of [A] and [B]. ### Claim 11 (depends on 1) The epoxy resin composition according to claim 1, wherein the optional aromatic polyamine hardener is not present, and the epoxy resin composition has a viscosity increase ratio after 2 hours at 80° C. of 7% to 30%, and a cured product of the epoxy resin composition has a flexural modulus of 4.1 to 4.5 GPa and a char production ratio at 650° C. of 25% to 30%. ### Claim 12 (depends on 1) The epoxy resin composition according to claim 1, wherein the optional aromatic polyamine hardener is present and is 3,3′-diaminodiphenyl sulfone. ### Claim 13 (depends on 12) The epoxy resin composition according to claim 12, wherein the epoxy resin composition has a viscosity increase ratio after 2 hours at 80° C. of 12% to 47%, and a cured product of the epoxy resin composition has a flexural modulus of 3.8 to 4.8 GPa and a char production ratio at 650° C. of 9% to 17%. ### Claim 14 (depends on 1) A prepreg obtained by impregnating a reinforced fiber with the epoxy resin composition described in claim 1. ### Claim 15 (depends on 14) A fiber-reinforced composite material obtained by curing the prepreg described in claim 14. ### Claim 16 (depends on 1) A fiber-reinforced composite material comprising a cured resin obtained by curing the epoxy resin composition described in claim 1, and a reinforced fiber. ### Claim 17 An epoxy resin composition comprising a difunctional glycidyl amine epoxy resin [A′] represented by general formula (4); at least one trifunctional or higher functional epoxy resin [B] selected from the group consisting of N,N,O-triglycidyl-m-aminophenol, N,N,O-triglycidyl-p-aminophenol, N,N,O-triglycidyl-4-amino-3-methylphenol, N,N,N′,N′-tetraglycidyl-4,4′-methylenedianiline, N,N,N′,N′-tetraglycidyl-2,2′-diethyl-4,4′-methylenedianiline and N,N,N′,N′-tetraglycidyl-m-xylylenediamine; at least one amine-based hardener [C] selected from the group consisting of an amine-based hardener having a structure represented by general formula (5) and an amine-based hardener having a structure represented by general formula (6); optionally, a non-phosphorus-containing aromatic polyamine hardener provided in an amount of up to 90 parts by mass based on 100 parts by mass total of [C′] and the aromatic polyamine hardener; and at least one thermoplastic resin [D] composed of a polyaryl ether skeleton: wherein in the general formula (4), R3 and R4 each independently represent at least one selected from the group consisting of a hydrogen atom, an aliphatic hydrocarbon group with a carbon number of 1 to 4, an alicyclic hydrocarbon group with a carbon number of 3 to 6, an aromatic hydrocarbon group with a carbon number of 6 to 10, a halogen atom, an acyl group, a trifluoromethyl group and a nitro group; and X3 represents one selected from the group consisting of —O—, —S—, —CO—, —C(═O)O— and —SO2−; wherein in the general formula (5), R5 represents a hydrocarbon group with a carbon number of 1 to 4; and in general formula (6), R6 represents a hydrogen atom or an amino group; wherein [A] is present in an amount of 10 to 50 parts by mass and [B] is present in an amount of 50 to 90 parts by mass, totaling 100 parts by mass; and wherein [C] is present in amount to provide a phosphorus atom content of 1.0 to 5.0% by mass, based on the overall mass of the epoxy resin composition. ### Claim 18 (depends on 17) The epoxy resin composition according to claim 17, wherein R3 and R4 of the general formula (4) is a hydrogen atom. ### Claim 19 (depends on 17) The epoxy resin composition according to claim 17, wherein [C′] comprises an amine-based hardener having a structure represented by general formula (6). ### Claim 20 (depends on 19) The epoxy resin composition according to claim 19, wherein R6 in the general formula (6) is an amino group. ### Claim 21 (depends on 17) The epoxy resin composition according to claim 17, wherein [D] comprises polyethersulfone. ### Claim 22 (depends on 21) The epoxy resin composition according to claim 21, wherein [D] is present in amount of 24 to 27 parts by mass based on the total 100 parts by mass of [A] and [B]. ### Claim 23 (depends on 17) The epoxy resin composition according to claim 17, wherein the optional aromatic polyamine hardener is not present, the epoxy resin composition has a viscosity increase ratio after 2 hours at 80° C. of 7% to 30%, and a cured product of the epoxy resin composition has a flexural modulus of 4.1 to 4.5 GPa and a char production ratio at 650° C. of 25% to 30%. ### Claim 24 (depends on 17) The epoxy resin composition according to claim 17, wherein the optional aromatic polyamine hardener is present and is 3,3′-diaminodiphenyl sulfone. ### Claim 25 (depends on 24) The epoxy resin composition according to claim 24, wherein the epoxy resin composition has a viscosity increase ratio after 2 hours at 80° C. of 13% to 47%, and a cured product of the epoxy resin composition has a flexural modulus of 4.3 to 4.6 GPa and a char production ratio at 650° C. of 11% to 17%. ### Claim 26 (depends on 17) A prepreg obtained by impregnating a reinforced fiber with the epoxy resin composition described in claim 17. ### Claim 27 (depends on 26) A fiber-reinforced composite material obtained by curing the prepreg described in claim 26. ### Claim 28 (depends on 17) A fiber-reinforced composite material comprising a cured resin obtained by curing the epoxy resin composition described in claim 17, and a reinforced fiber.