# US 10,119,001 B2 · Extended room temperature storage of epoxy resins > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,119,001 B2 - Document ID: US10119001B2 - Status: Granted - Kind: B2 - Application number: 15/229,067 - Filed: 2016-08-04 - Published: 2016-12-15 - Granted: 2018-11-06 - Earliest claimed: 2014-02-06 - Assignees: Hexcel Corporation; Hexcel Composites Limited - Applicants: Hexcel Corporation; Hexcel Composites Limited - Inventors: Yen-Seine Wang; Chris Mason; Martin Simmons - Web page: https://patentgrep.com/patent/US10119001B2 ## CPC - C08G 59/5033: {aromatic} - C08G 59/32: Epoxy compounds containing three or more epoxy groups - C08J 5/243: {using carbon fibres} - C08J 5/249: {characterised by the additives used in the prepolymer mixture} - C08K 5/18: with aromatically bound amino groups - C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins - C08L 77/02: Polyamides derived from omega-amino carboxylic acids or from lactams thereof (C08L77/10 takes precedence) - C08L 81/06: Polysulfones; Polyethersulfones - C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins - C08J 2477/00: Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers - C08J 2481/06: Polysulfones; Polyethersulfones - 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) - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) ## Abstract Uncured epoxy resin for use in making prepreg for aerospace applications. The resin includes an epoxy resin component comprising difunctional epoxy resin, trifunctional epoxy resin and/or tetrafunctional epoxy resin and a sufficient amount of [3-(4-aminobenzoyl) oxyphenyl]4-aminobenzoate (3-ABOAB), as a curing agent, such that the uncured resin can be stored at room temperature of at least 6 weeks and wherein the uncured resin can be fully cured in no more than 2 hours at a temperature of between 175° C. and 185° C. ## Claims ### Claim 1 A prepreg which can be stored at room temperature for at least 6 weeks and which can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C., said prepreg comprising: a fiber reinforcement; an uncured resin comprising: an epoxy resin component comprising a trifunctional epoxy resin selected from the group consisting of triglycidyl-m-aminophenol and triglycidyl-p-aminophenol; and a curing agent comprising a sufficient amount of [3-(4-aminobenzoyl) oxyphenyl]4-aminobenzoate such that the stoichiometric ratio between said epoxy resin component and said curing agent is between 0.65:1 and 1.1:0.8 and wherein said uncured resin can be stored at room temperature for at least 6 weeks and wherein said prepreg can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C. ### Claim 2 (depends on 1) A prepreg according to claim 1 wherein said epoxy resin component additionally comprises diglycidyl ether of bisphenol F. ### Claim 3 (depends on 2) A prepreg according to claim 2 wherein said epoxy resin component additionally comprises N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenyl methane. ### Claim 4 (depends on 1) A prepreg according to claim 1 wherein the said uncured resin comprises a soluble thermoplastic and insoluble thermoplastic particles. ### Claim 5 (depends on 4) A prepreg according to claim 4 wherein said soluble thermoplastic comprises polyethersulfone. ### Claim 6 (depends on 5) A prepreg according to claim 5 wherein said insoluble thermoplastic particles comprise polyamide particles. ### Claim 7 (depends on 1) A prepreg according to claim 1 wherein said epoxy resin component consists of triglycidyl-m-aminophenol and wherein the stoichiometric ratio between said triglycidyl-m-aminophenol and said curing agent is between 0.7:1 and 0.95:1. ### Claim 8 (depends on 7) A prepreg according to claim 7 wherein the said uncured resin comprises a soluble thermoplastic and insoluble thermoplastic particles. ### Claim 9 (depends on 8) A prepreg according to claim 8 wherein said soluble thermoplastic comprises polyethersulfone. ### Claim 10 (depends on 9) A prepreg according to claim 9 wherein said insoluble thermoplastic particles comprise polyamide particles. ### Claim 11 (depends on 2) A prepreg according to claim 2 wherein the said uncured resin comprises a soluble thermoplastic and insoluble thermoplastic particles. ### Claim 12 (depends on 11) A prepreg according to claim 11 wherein said soluble thermoplastic comprises polyethersulfone. ### Claim 13 (depends on 12) A prepreg according to claim 12 wherein said insoluble thermoplastic particles comprise polyamide particles. ### Claim 14 (depends on 3) A prepreg according to claim 3 wherein the said uncured resin comprises a soluble thermoplastic and insoluble thermoplastic particles. ### Claim 15 (depends on 14) A prepreg according to claim 14 wherein said soluble thermoplastic comprises polyethersulfone. ### Claim 16 (depends on 15) A prepreg according to claim 15 wherein said insoluble thermoplastic particles comprise polyamide particles. ### Claim 17 (depends on 1) A composite material comprising a prepreg according to claim 1 which has been cured. ### Claim 18 (depends on 17) A composite material according to claim 17 wherein said composite material forms at least part of a primary structure of an aircraft. ### Claim 19 A method for making a prepreg which can be stored at room temperature for at least 6 weeks and which can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C., said method comprising the steps of: providing an uncured resin which can be stored at room temperature for at least 6 weeks and which can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C., said uncured resin comprising: an epoxy resin component comprising a bifunctional epoxy resin selected from the group consisting of triglycidyl-m-aminophenol and triglycidyl-p-aminophenol; a curing agent comprising a sufficient amount of [3-(4-aminobenzoyl) oxyphenyl]4-aminobenzoate such that the stoichiometric ratio between said epoxy resin component and said curing agent is between 0.65:1 and 1.1:0.8 and wherein said uncured resin can be stored at room temperature for at least 6 weeks and wherein said uncured resin can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C.; and combining said uncured resin with a fibrous reinforcement to provide said prepreg. ### Claim 20 A method for storing an uncured resin at room temperature for up to six weeks or more, said method comprising the steps of: A) providing an uncured resin which can be stored at room temperature for at least 6 weeks and which can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C., said uncured resin comprising: a) an epoxy resin component comprising a bifunctional epoxy selected from the group consisting of triglycidyl-m-aminophenol and triglycidyl-p-aminophenol; b) a curing agent comprising a sufficient a count of [3-(4-aminobenzoyl) oxyphenyl]4-aminobenzoate such that the stoichiometric ratio between said epoxy resin component and said curing agent is between 0.651 and 1.1:0.8 and wherein said uncured resin can be stored at room temperature of at least 6 weeks and wherein said uncured resin can be fully cured in no more than 2 hours at a temperature of between 165° C. and 190° C.; and B) storing said uncured resin for up to 6 weeks or more at room temperature.