# US 2022/0033640 A1 · Epoxy resin compositions, prepreg, and fiber-reinforced composite materials

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- Number: US 2022/0033640 A1
- Document ID: US20220033640A1
- Status: Published application
- Kind: A1
- Application number: 17/276,659
- Filed: 2019-09-20
- Published: 2022-02-03
- Earliest claimed: 2018-09-21
- Assignees: Toray Industries, Inc.
- Applicants: Toray Industries, Inc.
- Inventors: Swezin Than Tun; Jonathan Hughes; Nobuyuki Arai
- Web page: https://patentgrep.com/patent/US20220033640A1

## CPC

- C08L 63/00: Compositions of epoxy resins; Compositions of derivatives of epoxy resins
- C08G 59/245: {aromatic}
- C08G 59/32: Epoxy compounds containing three or more epoxy groups
- C08G 59/50: Amines
- C08G 59/504: {containing an atom other than nitrogen belonging to the amine group, carbon and hydrogen}
- C08J 5/042: {with carbon fibres}
- C08J 5/24: Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
- C08J 5/243: {using carbon fibres}
- C08L 81/06: Polysulfones; Polyethersulfones
- C08J 2363/00: Characterised by the use of epoxy resins; Derivatives of epoxy resins
- C08L 2201/08: Stabilised against heat, light or radiation or oxydation
- C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
- C08L 2205/035: containing four or more polymers in a blend
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- 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)

## Abstract

An epoxy resin composition is provided which includes a poly-naphthalene-based epoxy resin having two or more epoxy groups per molecule combined with a non-linear multi-phenyl epoxy resin and an additional epoxy resin having an epoxy functionality of 3 or more, as well as a prepreg, and a fiber-reinforced composite material prepared using the epoxy resin composition. More specifically, an epoxy resin composition is provided which contains a combination of particular types of epoxy resins and curatives that, when cured, provides high flexural modulus and 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, epoxy resin systems are provided which are capable of achieving a high Tg along with good thermal stability for long periods of time at elevated temperatures (e.g., 180° C. or more) when cured at 210° C. for 2 hours.

## Claims

### Claim 1

An epoxy resin composition for a fiber-reinforced composite material comprising component (A), component (B), component (C), and component (D), wherein the epoxy resin composition when cured has a weight loss of less than 1.0% when thermally soaked at 180° C. for 1000 hours, and wherein:
component (A) comprises at least one poly-naphthalene-based epoxy resin;
component (B) comprises at least one non-linear multi-phenyl epoxy resin in a total amount of from 10 to 35 PHR per 100 PHR of total epoxy resin;
component (C) comprises at least one epoxy resin having an epoxy functionality of at least three which is neither a poly-naphthalene-based epoxy resin nor a non-linear multi-phenyl epoxy resin; and
component (D) comprises at least one amine curing agent.

### Claim 2 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (A) comprises at least one poly-naphthalene-based epoxy resin with two or more naphthalene structures and having an epoxy functionality of at least two as represented in Formula (I).
wherein R1 to R12 are each independently selected from the group consisting of hydrogen atoms, halogen atoms, C1 to C10 alkyl groups, C1 to C10 alkoxyl groups, C1 to C10 fluoroalkyl groups, cycloalkyl groups, aryl groups, aryloxyl groups, and glycidoxy groups, Y1 to Y3 are each independently selected from the group consisting of hydrogen atoms, halogen atoms, C1 to C10 alkyl groups, C1 to C10 alkoxyl groups, C1 to C10 fluoroalkyl groups, cycloalkyl groups, aryl groups, aryloxyl groups, and glycidoxy groups, wherein each benzene nucleus may be substituted with one or more Y groups, n is 0 or an integer of 1 to 5, k is 0 or an integer of 1 to 3, wherein the Y groups may be attached to either or both rings of each naphthalene nucleus; and each X is independently selected from the group consisting of a direct bond, —CH2—, —C(CH3)2—, —S—, —SO2—, —O—, —C(═O)O—, —C(═O)—, —C(═O)NH—, C1 to C6 alkylene groups, C1 to C6 alkoxylene groups, cycloalkylene groups, arylene groups and aryloxylene groups, wherein these groups are optionally employed individually or different groups are optionally employed in combination as X.

### Claim 3 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (B) comprises at least one non-linear multi-phenyl epoxy resin having a structure corresponding to Formula (II):
X1—C(Y)(Z)—X2 Formula (II)
wherein X1 and X2 are the same or different and are each independently selected from the group consisting of glycidyl ether-substituted phenyl groups and hydroxyl-substituted phenyl groups; wherein either:
i) Y is selected from the group consisting of glycidyl ether-substituted phenyl groups, hydroxyl-substituted phenyl groups, and —C(H)(X3)(X4), wherein X3 and X4 are the same or different and are each independently selected from the group consisting of glycidyl ether-substituted phenyl groups and hydroxyl-substituted phenyl groups and wherein X3 and X4 are the same as or different from X1 and X2; and Z is H; or
ii) C(Y)(Z) represents a fluorene group, wherein the carbon atom represented by C in C(Y)(Z) is at the 9 position of the fluorene group;
and oligomers thereof; subject to the proviso that the non-linear multi-phenyl epoxy resin comprises at least two glycidyl ether groups per molecule.

### Claim 4 (depends on 3)

The epoxy resin composition according to claim 3, wherein component (B) comprises at least one non-linear multi-phenyl epoxy resin selected from the group consisting of tris and higher (hydroxyphenyl) methane-based epoxy resins, tetra(hydroxyphenyl) ethane-based epoxy resins, fluorene-based epoxy resins, oligomers thereof, and combinations thereof.

### Claim 5 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (D) comprises at least one aromatic polyamine curing agent.

### Claim 6 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (D) comprises at least one diaminodiphenyl sulfone.

### Claim 7 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (A) comprises 15 to 50 PHR in total per 100 PHR of total epoxy resin.

### Claim 8 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (C) comprises 30 to 50 PHR in total per 100 PHR of total epoxy resin.

### Claim 9 (depends on 1)

The epoxy resin composition according to claim 1, wherein component (D) is present in an amount and component (A), component (B), and component (C) are present in a total amount effective to provide a molar ratio of active hydrogens to epoxy groups ranging from 0.8:1 to 1.2:1.

### Claim 10 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition when cured has a hot/wet flexural modulus of 1.9 GPa or greater when tested at 121° C.

### Claim 11 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition when cured has a hot/wet flexural modulus of 2.0 GPa or greater when tested at 121° C.

### Claim 12 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition when cured has a hot/wet flexural modulus of 2.1 GPa or greater when tested at 121° C.

### Claim 13 (depends on 1)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition when cured has a wet Tg of greater than 200° C.

### Claim 14 (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 15 (depends on 1)

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

### Claim 16 (depends on 15)

The epoxy resin composition according to claim 15, wherein the at least one thermoplastic resin comprises at least one polyethersulfone.

### Claim 17 (depends on 16)

The epoxy resin composition according to claim 16, comprising at least 10 PHR of polyethersulfone.

### Claim 18 (depends on 17)

The epoxy resin composition according to claim 17, wherein the epoxy resin composition has a viscosity at 40° C. between 1×103 Pa*s and 3×104 Pa*s and a minimum viscosity greater than 1 Pa*s.

### Claim 19

An epoxy resin compositions which comprises:
(A) at least 20 PHR in total per 100 PHR of total epoxy resin of at least one poly-naphthalene-based epoxy resin having Formula (I):
wherein R1 to R12 are each independently selected from the group consisting of hydrogen atoms, halogen atoms, C1 to C10 alkyl groups, C1 to C10 alkoxyl groups, C1 to C10 fluoroalkyl groups, cycloalkyl groups, aryl groups, aryloxyl groups, and glycidoxy groups, Y1 to Y3 are each independently selected from the group consisting of hydrogen atoms, halogen atoms, C1 to C10 alkyl groups, C1 to C10 alkoxyl groups, C1 to C10 fluoroalkyl groups, cycloalkyl groups, aryl groups, aryloxyl groups, and glycidoxy groups, wherein each benzene nucleus may be substituted with one or more Y groups, n is 0 or an integer of 1 to 5, k is 0 or an integer of 1 to 3, wherein the Y groups may be attached to either or both rings of each naphthalene nucleus; and each X is independently selected from the group consisting of a direct bond, —CH2—, —C(CH3)2—, —S—, —SO2—, —O—, —C(═O)O—, —C(═O)—, —C(═O)NH—, C1 to C6 alkylene groups, C1 to C6 alkoxylene groups, cycloalkylene groups, arylene groups and aryloxylene groups, wherein these groups are optionally employed individually or different groups are optionally employed in combination as X;
(B) at least one non-linear multi-phenyl epoxy resin with an epoxy functionality of three or more selected from the group consisting of tris and higher (hydroxyphenyl) methane-based epoxy resins, tetra(hydroxyphenyl) ethane-based epoxy resins, fluorene-based epoxy resins, oligomers thereof, and combinations thereof in an amount of at least 10 PHR in total per 100 PHR of total epoxy resin;
(C) at least one epoxy resin having an epoxy functionality of at least three which is neither a poly-naphthalene-based epoxy resin nor a non-linear multi-phenyl epoxy resin and which is a glycidyl ether of a diamine or a compound containing at least one amine group and at least one hydroxyl group per molecule;
(D) at least one curing agent which comprises at least one diaminodiphenyl sulfone, wherein component (D) and components (A), (B), and (C) are present in amounts effective to provide a molar ratio of active hydrogens:epoxy groups ranging from 0.8:1 to 1.2:1;
(E) at least one thermoplastic resin selected from the group consisting of polyethersulfones in an amount of from 5 to 30 PHR per 100 PHR of total epoxy resin; and
(F) optionally, organic particles.

### Claim 20 (depends on 1)

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

### Claim 21 (depends on 20)

A fiber-reinforced composite material, obtained by curing a prepreg in accordance with claim 20.

### Claim 22 (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 23 (depends on 20)

A method of making a fiber-reinforced composite material, comprising curing a prepreg in accordance with claim 20 at a temperature of from 170° C. to 230° C.