Epoxy resin composition, fiber-reinforced composite material, and method for producing the same

a technology of epoxy resin and composite material, which is applied in the direction of weaving, transportation and packaging, textiles and paper, etc., can solve the problems of reducing the tg and elastic modulus the improvement of the toughness of the epoxy resin cured product, and the inability to achieve the desired toughness-enhancing effect, etc., to achieve good impregnation of reinforcing fibers, low viscosity, and high elastic modulus

Inactive Publication Date: 2011-04-28
TORAY IND INC
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

[0023]According to the present invention, it is possible to provide an epoxy resin composition which has low viscosity allowing good impregnation of reinforcing fibers therewith, high Tg important to allow a fiber-reinforced composite material to have heat resistance, high elastic modulus important to allow a fiber-reinforced composite material to have excellent compressive strength, and excellent fracture toughness necessary to allow a fiber-reinforced composite material to have excellent impact resistance, fatigue resistance, and open-hole tensile strength. Therefore, a fiber-reinforced composite material comprising at least a cured product of the epoxy resin composition according to the present invention and carbon fibers is excellent in heat resistance, compressive strength, impact resistance, fatigue resistance, and open-hole tensile strength. Such a fiber-reinforced composite material is suitable for producing structural parts of aircraft, spacecraft, vehicles, ships, and the like.

Problems solved by technology

However, epoxy resin cured products obtained by curing epoxy resin compositions are generally brittle, and therefore an improvement in the toughness of epoxy resin cured products is an important issue in improving the impact resistance and fatigue resistance of fiber-reinforced composite materials.
Also from such a viewpoint, an improvement in the toughness of epoxy resin cured products is an important issue.
This causes a problem that a desired toughness-improving effect cannot be obtained due to a change in the morphology of a cured product depending on the kind of epoxy resin composition used or curing conditions.
In addition, a rubber component is partially dissolved in an epoxy resin phase of an epoxy resin cured product, which causes a problem that the viscosity of the epoxy resin composition is increased and the Tg and elastic modulus of the epoxy resin cured product are lowered.
Therefore, there is a remaining problem that addition of a large amount of core-shell polymer particles lowers the elastic modulus of an epoxy resin cured product, thereby lowering the compressive strength of a fiber-reinforced composite material in its fiber direction.Patent Document 1: JP-B-61-29613Patent Document 2: JP-B-62-34251Patent Document 3: JP-A-5-65391Patent Document 4: JP-A-7-224144Patent Document 5: JP-A-2003-277579Patent Document 6: JP-A-2006-257391

Method used

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  • Epoxy resin composition, fiber-reinforced composite material, and method for producing the same
  • Epoxy resin composition, fiber-reinforced composite material, and method for producing the same
  • Epoxy resin composition, fiber-reinforced composite material, and method for producing the same

Examples

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examples

[0093]Hereinbelow, the present invention will be more specifically described with reference to the following examples. Resin raw materials, a method for preparing an epoxy resin composition, a method for producing a cured product, and measurement methods of various properties used in the examples are as follows.

[0094]

[0095]An epoxy resin composition was prepared using the following commercially-available products.

[0096](1) Epoxy Resins

[0097](a) Bifunctional Epoxy Resins (Component A)

[0098]GAN (N,N-diglycidyl aniline manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 125 g / mol)

[0099]GOT (N,N-diglycidyl-o-toluidine manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 135 g / mol)

[0100]“DENACOL™” EX721 (phthalic acid diglycidyl ester manufactured by Nagase Chemtex Corporation, epoxy equivalent: 154 g / mol)

[0101]AK601 (hexahydrophthalic acid diglycidyl ester manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent: 154 g / mol)

[0102](b) Tri- or Higher-Functional Aromatic Epoxy...

examples 1 to 9

[0173]Epoxy resin compositions were prepared using the resin raw materials shown in Table 1, and the initial viscosity of each of the epoxy resin compositions at 70° C. was measured. As a result, all the epoxy resin compositions had sufficiently low viscosity. Then, the epoxy resin compositions were cured to obtain cured products, and the Tg, flexural modulus, and mode I fracture toughness of each of the cured products were measured. As a result, all the cured products had high Tg, high elastic modulus, and high toughness. From the result, it was found that all the cured products of Examples 1 to 9 were excellent. Among them, the cured products of Examples 2, 3, 5, 6, and 8 had very high Tg, very high elastic modulus, and very high toughness. From the result, it was found that the cured products of Examples 2, 3, 5, 6, and 8 were particularly excellent.

TABLE 1Unit of resin raw material content: part(s) by massExam-Exam-Exam-Exam-Exam-Exam-Exam-Exam-Exam-ple 1ple 2ple 3ple 4ple 5ple ...

examples 10 and 11

[0174]Epoxy resin compositions were prepared using the resin raw materials shown in Table 2, and the initial viscosity of each of the epoxy resin compositions at 70° C. was measured. As a result, both the epoxy resin compositions had sufficiently low viscosity. Then, the epoxy resin compositions were cured to obtain cured products, and the Tg, flexural modulus, and mode I fracture toughness of each of the cured products were measured. As a result, both the cured products had high Tg, high elastic modulus, and high toughness. From the result, it was found that the cured products of Examples 10 and 11 were excellent. However, the epoxy resin compositions of Examples 1 and 2 had lower viscosity as compared to the epoxy resin compositions of Examples 10 and 11, and the cured products of Examples 1 and 2 had higher Tg as compared to the cured products of Examples 10 and 11. From the result, it was found that the cured products of Examples 1 and 2 were more excellent as compared to the cu...

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Abstract

Disclosed herein are an epoxy resin composition for fiber-reinforced composite materials which has low viscosity, high Tg, high elastic modulus, and excellent fracture toughness and a fiber-reinforced composite material using such an epoxy resin composition which has excellent thermal properties, compressive strength, impact resistance, fatigue resistance, and open-hole tensile strength and which is suitable for producing structural parts of aircraft and the like. The epoxy resin composition comprises at least a given bifunctional epoxy resin as a component (A), a liquid aromatic diamine curing agent as a component (B), and core-shell polymer particles as a component (C), wherein the core-shell polymer particles as the component (C) contain epoxy groups in their shell and have a volume-average particle size of 50 to 300 nm.

Description

FIELD OF THE INVENTION[0001]The present invention relates to an epoxy resin composition for use as a matrix resin of fiber-reinforced composite materials suitable for producing structural parts of aircraft, spacecraft, vehicles, ships, and the like. More specifically, the present invention relates to an epoxy resin composition having low viscosity, high glass transition temperature (hereinafter, glass transition temperature is sometimes abbreviated as “Tg”), high elastic modulus, and excellent fracture toughness. Further, the present invention relates to a fiber-reinforced composite material produced using such an epoxy resin composition and a method for producing such a fiber-reinforced composite material.BACKGROUND ART[0002]Fiber-reinforced composite materials composed of reinforcing fibers such as glass fibers, carbon fibers, and aramid fibers and cured products of thermosetting resins such as unsaturated polyester resins, vinyl ester resins, epoxy resins, phenol resins, cyanate ...

Claims

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Application Information

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Patent Type & Authority Applications(United States)
IPC IPC(8): D03D13/00C08L63/00B29C39/00B29C45/14
CPCC08G59/3209C08G59/38C08G59/5033C08L63/00C08J5/04C08J2363/00C08K7/02C08J3/20Y10T428/249922B29C70/06B29C70/443B29C71/02B29K2063/00B29K2307/04C08J5/047C08J2463/02C08J2477/06
Inventor KAMAE, TOSHIYAKOCHI, SHINJIMIYOSHI, MASAYUKIYOSHIOKA, KENICHI
Owner TORAY IND INC
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