# US 2019/0169356 A1 · Epoxy resin composition, prepreg, and fiber reinforced plastic material

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- Number: US 2019/0169356 A1
- Document ID: US20190169356A1
- Status: Published application
- Kind: A1
- Application number: 16/323,147
- Filed: 2017-08-24
- Published: 2019-06-06
- Earliest claimed: 2016-08-26
- Assignees: Toray Industries, Inc.
- Applicants: Toray Industries, Inc.
- Inventors: Swezin Than Tun; Jonathan Hughes; Nobuyuki Arai; Benjamin Lehman
- Web page: https://patentgrep.com/patent/US20190169356A1

## CPC

- C08G 59/3227: {Compounds containing acyclic nitrogen atoms}
- C08G 59/32: Epoxy compounds containing three or more epoxy groups
- C08G 59/38: together with di-epoxy compounds
- C08G 59/4021: {Ureas; Thioureas; Guanidines; Dicyandiamides}
- C08G 59/4223: {aromatic}
- C08G 59/686: {containing nitrogen}
- C08J 5/04: Reinforcing macromolecular compounds with loose or coherent fibrous material
- C08J 5/243: {using carbon fibres}
- C08J 5/249: {characterised by the additives used in the prepolymer mixture}
- C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins
- C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins
- C08J 2375/00: Characterised by the use of polyureas or polyurethanes; Derivatives of such polymers
- C08L 2205/02: containing two or more polymers of the same C08L -group
- 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)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)

## Abstract

The embodiments herein relate to an epoxy resin composition containing a specific type of amine-based epoxy resin containing four epoxy groups per molecule, a prepreg, and a fiber-reinforced composite material. More specifically, the embodiments herein relate to an epoxy resin composition containing a combination of particular types of epoxy resin and curatives that provides high flexural modulus that is suitable for preparing a fiber-reinforced composite material capable of withstanding extreme use environments such as low-temperature environments and high-temperature moisture-absorbing environments. In addition, the embodiments herein relate to epoxy resin systems capable of achieving a high degree of cure (e.g., 85% or more) within a relatively short period of time (e.g., less than two hours) at a relatively low temperature (e.g., 132° C.).

## Claims

### Claim 1

An epoxy resin composition for a fiber-reinforced composite material comprising components (A), (B), (C), and (D), wherein the epoxy resin composition has a degree of cure of at least 90% after being cured at 132° C. for 2 hours and a room temperature flexural modulus of at least 4.5 GPa after being cured at 132° C. for 2 hours, wherein components (A), (B), (C), and (D) comprise:
(A) at least 20 phr per 100 phr of total epoxy resin of at least one tetrafunctional amine-based epoxy represented by formula (1), wherein X is a divalent moiety having a molecular weight of at least 15 g/mol and R1 to R4 are each independently selected from the group consisting of a hydrogen atom, halogen atoms, C1 to C6 alkyl groups, C1 to C6 alkoxyl groups, C1 to C6 fluoroalkyl groups, cycloalkyl groups, aryl groups, and aryloxyl groups wherein these groups are optionally employed individually or different groups are optionally employed in combination as each of R1 to R4;
(B) optionally, at most 80 phr per 100 phr of total epoxy resin of at least one epoxy resin other than component (A);
(C) at least one amine-based curing agent, wherein components (A), (B), and (C) are each present in an amount effective to provide a molar ratio of active hydrogens:epoxy groups ranging from 0.2:1 to 0.9:1; and
(D) at least one urea-based catalyst.

### Claim 2 (depends on 1)

The epoxy resin composition according to claim 1, wherein X is comprised of at least one heteroatom selected from the group consisting of S, N and O.

### Claim 3 (depends on 1)

The epoxy resin composition according to claim 1, wherein X is selected so as to provide the at least one tetrafunctional amine-based epoxy represented by formula (1) with a dipole moment of at least 0.5 Debye.

### Claim 4 (depends on 1)

The epoxy resin composition according to claim 1, wherein X is selected from the group consisting of —S—, —S02-, —O—, —C(═O)O—, —C(═O)—, —NR5—, —C(C═O)NR6C(═O)—, —NR7C(═O)NR8—, —OC(═O)NR9— and —OC(═O)O—, wherein R5-R9 are each independently selected from the group consisting of a hydrogen atom, halogen atoms, C1 to C6 alkyl groups, C1 to C6 alkoxyl groups, C1 to C6 fluoroalkyl groups, cycloalkyl groups, aryl groups, and aryloxyl groups.

### Claim 5 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (A) is comprised of at least one epoxy resin selected from the group consisting of tetraglycidyl diaminodiphenyl ethers, tetraglycidyl diamino methyldiphenyl ethers, tetraglycidyl diamino dimethyldiphenyl ethers, tetraglycidyl diamino dibromodiphenyl ethers, tetraglycidyl diaminodiphenyl sulfones, tetraglycidyl diamino methyldiphenyl sulfones, tetraglycidyl diamino dimethyldiphenyl sulfones, tetraglycidyl diamino dibromodiphenyl sulfones, tetraglycidyl diaminodiphenyl thioethers, tetraglycidyl diamino benzyl benzoates, tetraglycidyl diamino phenyl benzoates, tetraglycidyl diaminobenzanilides, and combinations thereof.

### Claim 6 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (B) is present and is comprised of a component (B1) and a component (B2) which are different from each other.

### Claim 7 (depends on 6)

The epoxy resin composition according to claim 6, wherein component (B1) comprises an epoxy resin having more than two epoxy-functional groups per molecule.

### Claim 8 (depends on 6)

The epoxy resin composition according to claim 6, wherein component (B2) comprises an epoxy resin having less than three epoxy-functional groups per molecule.

### Claim 9 (depends on 8)

The epoxy resin composition according to claim 8, wherein the epoxy resin having less than three epoxy-functional groups per molecule has an average epoxy equivalent weight of less than 205 g/eq.

### Claim 10 (depends on 8)

The epoxy resin composition according to claim 8, wherein the epoxy resin having less than three epoxy-functional groups per molecule has an average epoxy equivalent weight of less than 170 g/eq.

### Claim 11 (depends on 8)

The epoxy resin composition according to claim 8, wherein component (B2) is present in an amount of at most 30 phr per 100 phr of total epoxy resin.

### Claim 12 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (B) comprises at least one tetraglycidyl amine epoxy resin.

### Claim 13 (depends on 6)

The epoxy resin composition according to claim 6, wherein component (B1) comprises at least one tetraglycidyl amine epoxy resin and component (B2) comprises at least one epoxy resin selected from the group consisting of bisphenol-A epoxy resins, diglycidylaniline, and cycloaliphatic epoxy resins.

### Claim 14 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (C) comprises at least one diaminodiphenyl sulfone or a combination of dicyandiamide and diaminodiphenyl sulfone.

### Claim 15 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (C) consists of diaminodiphenyl sulfone which is present in an amount ranging from 10 to 30 phr per 100 phr of total epoxy resin and components (A), (B), and (C) are present in amounts effective to provide a molar ratio of active hydrogens:epoxy groups ranging from 0.2:1 to 0.6:1.

### Claim 16 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (C) is comprised of diaminodiphenyl sulfone and dicyandiamide, wherein dicyandiamide is present in an amount of at most 7 phr per 100 phr of total epoxy resin, and components (A), (B), and (C) are present in amounts effective to provide a molar ratio of active hydrogens:epoxy groups ranging from 0.2:1 to 0.9:1.

### Claim 17 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (D) comprises at least one urea-based catalyst selected from the group consisting of N,N-dimethyl-N′-(3,4-dichlorophenyl) urea, toluene bis(dimethylurea), 4,4′-methylene bis(phenyl dimethylurea), N-(4-chlorophenyl) N,N-dimethyl urea and 3-phenyl-1,1-dimethylurea.

### Claim 18 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (D) is present in an amount ranging from 1 to 8 phr per 100 phr of total epoxy resin.

### Claim 19 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition when cured at 132° C. for 2 hours has a glass transition temperature of at least 130° C.

### Claim 20 (depends on 1)

The epoxy resin composition of claim 1, wherein the epoxy resin composition has a viscosity increase less than 2 times the starting viscosity when held at 65° C. for 2 hours.

### Claim 21 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition further comprises at least one thermoplastic resin.

### Claim 22 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition is comprised of at least 5 phr component (B) per 100 phr of total epoxy resin.

### Claim 23 (depends on 1)

A prepreg, comprising a reinforcing fiber matrix impregnated with an epoxy resin composition in accordance with claim 1.

### Claim 24 (depends on 23)

A fiber-reinforced composite material obtained by curing a prepreg in accordance with claim 23.

### Claim 25 (depends on 1)

A fiber-reinforced composite material, comprising a cured epoxy resin product obtained by curing a mixture comprised of an epoxy resin composition in accordance with claim 1 and a reinforcing fiber.

### Claim 26 (depends on 25)

A method of making a fiber-reinforced composite material, comprising curing a prepreg in accordance with claim 25 at a temperature of from 110° C. to 150° C.

### Claim 27 (depends on 16)

The epoxy resin composition according to claim 16, wherein diaminodiphenyl sulfone is present in an amount ranging from 10 to 30 phr per 100 phr of total epoxy resin.