JP6776649B2 - Epoxy resin composition, and films, prepregs and fiber reinforced plastics using it. - Google Patents

Description

The present invention relates to an epoxy resin composition preferably used for fiber reinforced plastics used for sports / leisure applications and industrial applications, and films, prepregs and fiber reinforced plastics using the same.

Fiber reinforced plastic, which is one of the fiber reinforced composite materials, is lightweight, has high strength, and has high rigidity, so that it is widely used in sports / leisure applications, automobile applications, aircraft applications, industrial applications, and the like.

As a method for producing fiber reinforced plastic, there is a method of using an intermediate material, that is, a prepreg, in which a reinforcing material made of long fibers (continuous fibers) such as reinforcing fibers is impregnated with a matrix resin. According to this method, there is an advantage that the content of the reinforcing fiber of the fiber reinforced plastic can be easily controlled and the content can be designed to be higher.

Specific methods for obtaining fiber reinforced plastic from prepreg include a method using an autoclave, press molding, internal pressure molding, oven molding, and sheet wrap molding.

Among the fiber reinforced plastics, the fiber reinforced plastic tubular body is widely used for sports and leisure applications such as fishing poles, golf club shafts, ski poles, and bicycle frames. By utilizing the high elastic modulus of fiber reinforced plastic, it is possible to fly a ball or a fishing hook far away with a low force due to the bending and recoil that occurs when the tubular body is shaken. Further, by using a tubular body, it is possible to reduce the weight and improve the operability of the user.

In recent years, there has been an increasing need for weight reduction, so efforts are being made to replace some of the carbon fibers with high elastic modulus types.

However, the high elastic modulus type carbon fiber generally tends to have a low strength, and the amount used may be limited because the fiber reinforced plastic is easily broken. In addition, since carbon fibers of high elastic modulus type are generally expensive, the amount used may be limited from an economical point of view. If the amount of prepreg used is reduced to reduce the weight of the current carbon fiber, the breaking strength of the tubular body will decrease.

Against this background, it is required to improve the breaking strength of the fiber-reinforced plastic tubular body by a method other than changing the elastic modulus of the carbon fiber.

In order to solve such a problem, it has been proposed to use, for example, the epoxy resin compositions described in Patent Documents 1 to 3.

Japanese Unexamined Patent Publication No. 2009-215481 JP-A-2010-57462 Japanese Patent No. 5804222

However, the epoxy resin compositions disclosed in Patent Documents 1 to 3 do not have sufficient 0 ° bending strength and 90 ° bending strength of fiber reinforced plastics.

The present invention has been made in view of the above background, and it has been found that a fiber reinforced plastic having excellent mechanical properties can be obtained by using a specific epoxy resin composition as a matrix resin. In particular, an epoxy resin composition capable of obtaining excellent breaking strength when used as a material for tubular fiber reinforced plastics, a prepreg using the resin composition, and a fiber reinforced formed using this prepreg. Provide plastic.

As a result of diligent studies, the present inventors have found that by using an epoxy resin having a specific structure, the above-mentioned problems can be solved and a fiber-reinforced plastic having desired performance can be provided, and the present invention has been reached.

That is, the gist of the present invention is as follows.
[1] An epoxy resin composition containing the following components (A), (B), (C) and (D).
Component (A) Trifunctional Epoxy Resin Component (B) Epoxy Resin Other Than Component (A) Solid at 25 ° C Component (C) Epoxy Resin Other Than Component (A) Liquid at 25 ° C Component (D) Curing Agent

[2] The epoxy resin composition according to [1], wherein the component (B) contained in the epoxy resin composition has an epoxy equivalent of 500 or less.
[3] The epoxy resin composition according to [1] or [2], wherein the component (C) contained in the epoxy resin composition has an epoxy equivalent of 500 or less.
[4] The component (B) is an epoxy resin having a softening point or a melting point of 50 ° C. or higher.
The epoxy resin composition according to any one of [1] to [3].
[5] The component (B) contains an epoxy resin represented by the following general formula (1).
The epoxy resin composition according to any one of [1] to [4].
In the formula, n and m represent mean values, n is a real number in the range of 1 to 10, m is a real number in the range of 0 to 10, and R ₁ and R ₂ are independently hydrogen atoms and carbon atoms 1, respectively. ~
Shows an alkyl group or a trifluoromethyl group having four.
[6] The epoxy resin composition according to any one of [1] to [5], which contains the alicyclic epoxy resin represented by the following general formula (2) as the component (B).
[In formula (2), R1 represents a p-valent organic group. p represents an integer of 1 to 20.
q represents an integer of 1 to 50, and the sum of q in the equation (2) is an integer of 3 to 100.
R2 represents either of the groups represented by the following formula (2a) or (2b). However,
At least one of R2 in the formula (2) is a group represented by the formula (2a).

[7] As the alicyclic epoxy resin, 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol is contained in [6]. The epoxy resin composition described.
[8] Any of [1] to [7], wherein the content of the component (B) is 5 parts by mass to 90 parts by mass with respect to 100 parts by mass of the total amount of the epoxy resin contained in the epoxy resin composition. The epoxy resin composition according to item 1.
[9] The epoxy resin composition according to any one of [1] to [8], wherein the component (C) is a bisphenol type epoxy resin. [10] The epoxy resin contained in the epoxy resin composition. The epoxy resin composition according to any one of [1] to [9], wherein the content of the component (C) is 20 parts by mass to 50 parts by mass with respect to 100 parts by mass of the total amount.
[11] The epoxy resin composition according to any one of [1] to [10], wherein the component (D) is dicyandiamide.
[12] The epoxy resin composition according to any one of [1] to [11], further containing a urea-based curing aid as the component (E).
[13] A film comprising the epoxy resin composition according to any one of [1] to [12].
[14] A prepreg in which a reinforcing fiber base material is impregnated with the epoxy resin composition according to any one of [1] to [13].
[15] A fiber-reinforced plastic composed of a cured product of the epoxy resin composition according to any one of [1] to [14] and reinforced fibers.
[16] The fiber reinforced plastic according to [15], which is tubular.

By using the epoxy resin composition of the present invention as a matrix resin of a fiber reinforced plastic, a fiber reinforced plastic having excellent mechanical properties can be obtained. In particular, by using the epoxy resin composition of the present invention, excellent breaking strength can be obtained in a tubular fiber reinforced plastic.

The present invention relates to an epoxy resin composition containing the following components (A), (B), (C) and (D) and uses thereof.

Component (A) Trifunctional Epoxy Resin Component (B) Epoxy Resin Other Than Component (A) Solid at 25 ° C Component (C) Epoxy Resin Other Than Component (A) Liquid at 25 ° C Component (D) Curing Agent

Generally, the term epoxy resin is used as the name of one category of thermosetting resin or the name of the chemical substance category of a compound having an epoxy group in the molecule, but in the present invention, it is used in the latter meaning. (However, it is assumed that the mass average molecular weight of the epoxy resin is less than 50,000). In addition, the term epoxy resin composition means a composition containing an epoxy resin, a curing agent, and optionally other additives.

In the present specification, "-" includes numerical values and ratios described before and after this "-".
Further, in the present invention, "the bending elasticity of the cured product of the epoxy resin composition" is referred to as "the bending elasticity of the resin", and "the bending breaking strain of the cured product of the epoxy resin composition" is referred to as "the bending of the resin (of)". Called "breaking strain", 90 ° bending strength and 0 ° bending strength of a fiber reinforced plastic consisting of a cured product of an epoxy resin composition and a reinforced fiber base material in which carbon fibers, which are continuous fibers, are aligned in one direction. May be simply referred to as "90 ° bending strength of fiber reinforced plastic" and "0 ° bending strength of fiber reinforced plastic".

Hereinafter, each component will be described in detail.

"Component (A): Trifunctional epoxy resin"
The trifunctional epoxy resin as the component (A) increases the bending strength and bending elasticity of the cured product of the epoxy resin composition, and when used as a matrix resin of fiber reinforced plastic, the bending strength of the fiber reinforced plastic, that is, Is a component capable of increasing 90 ° bending strength and 0 ° bending strength.

The trifunctional epoxy resin contains a compound having three glycidyl groups in one molecule, and is, for example, triglycidyl-m-aminophenol, Araldide MY0600 (manufactured by Huntsman Corporation), Araldide MY0610 (Huntsman Corporation). ) Triglycidyl-p-aminophenol MY0500 ((Huntsman Corporation)), MY0510 ((Huntsman Corporation) triazine-modified epoxy resin TEPIC (Nissan Chemical Co., Ltd.), Trishydroxyphenyl Taxix742 (manufactured by Huntsman Corporation), which is a methane-type epoxy resin, and the like can be mentioned. One type or two or more types of these can be used.

The component (A) is preferably 1 part by mass to 50 parts by mass with respect to 100 parts by mass of the total amount of all the epoxy resins contained in the epoxy resin composition of the present invention. This is a case where the amount of the component (A) is 1 part by mass or more, the bending strength and the flexural modulus of the cured product of the epoxy resin composition of the present invention are increased, and this is used for the matrix resin of the fiber reinforced plastic. This is because the bending strength of the fiber reinforced plastic tends to be increased. More preferably, it is 5 parts by mass or more. Further, when the amount of the component (A) is 50 parts by mass or less, the viscosity of the resin composition can be appropriately maintained, and film formation in the prepreg manufacturing process tends to be facilitated. More preferably, it is 20 parts by mass or less.

"Component (B): Epoxy resin other than component (A) solid at 25 ° C"
The epoxy resin composition of the present invention contains a solid epoxy resin at 25 ° C. as the component (B).
This epoxy resin solid at 25 ° C. enhances the bending strength, bending elasticity and heat resistance of the cured product of the epoxy resin composition, and when used as a matrix resin of fiber reinforced plastic, the matrix resin to the reinforcing fibers Adhesion can be improved.

The epoxy resin solid at 25 ° C. is at least one selected from the group consisting of, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, oxazolidone ring type epoxy resin, and alicyclic epoxy resin. Is. One or more of these components (B) can be appropriately selected and used, but those having a softening point or a melting point of 50 ° C. or higher are preferably used.
This is because by using a component (B) having a softening point or a melting point of 50 ° C. or higher, an appropriate tack can be obtained for the prepreg, and the handleability tends to be improved. It is more preferably 60 ° C. or higher, and even more preferably 70 ° C. or higher. The softening point or melting point of the component (B) is preferably 160 ° C. or lower from the viewpoint of good compatibility with other components. More preferably, it is 150 ° C. or lower.

Examples of the bisphenol A type epoxy resin that can be used as the component (B) include jER1001 (softening point 64 ° C.), jER1003 (softening point: 89 ° C.), jER1004 (softening point: 97 ° C.), and jER1007 (softening point). : 128 ° C), jER1009 (softening point: 144 ° C) (above, manufactured by Mitsubishi Chemical Corporation), Epototo YD-014 (softening point: 91-102 ° C), Epototo YD-017 (softening point: 117-127) ° C.), Epotote "YD-019 (softening point: 130 to 145 ° C.) (above, manufactured by Toto Kasei Co., Ltd.) and the like.
Examples of the bisphenol F type epoxy resin that can be used as the component (B) include jER4004P (softening point: 85 ° C.), jER4007P (softening point: 108 ° C.), jER4010P (softening point: 135 ° C.) (or more. , Mitsubishi Chemical Corporation), etc.
Further, examples of the bisphenol S-type epoxy resin that can be used include EXA-1514 (softening point: 75 ° C.), EXA-1517 (softening point: 60 ° C.) (all manufactured by DIC Corporation) and the like. be able to.
Examples of the oxazolidone ring-type epoxy resin that can be used as the component (B) include AER4152 (softening point: 98 ° C.), XAC4151 (softening point: 98 ° C.) (all manufactured by Asahi Kasei Ematel Al Co., Ltd.). ACR1348 (manufactured by ADEKA Co., Ltd.), DER858 (manufactured by DOW, softening point: 100 ° C.), TSR-400 (manufactured by DIC Corporation, softening point: 79 ° C.) and the like can be mentioned.

Further, as the component (B), an epoxy resin represented by the following general formula (1) can be used. By this use, the bending strength of the cured product of the epoxy resin composition can be further increased, and when used as a matrix resin of a fiber reinforced plastic, the 90 ° bending strength of the fiber reinforced plastic can be further increased.

In the formula, n and m represent average values, n is a real number in the range of 1 to 10, m is a real number in the range of 0 to 10, and R ₁ and R ₂ are independently hydrogen atoms and carbon atoms 1, respectively. Shows an alkyl group or trifluoromethyl group having ~ 4 pieces.

Examples of the epoxy resin represented by the general formula (1) include NER-7604, NER-7403, NER-1302, and NER-1202 (all manufactured by Nippon Kayaku Co., Ltd .: epoxy equivalent 200 to 500 g / eq., Softening point 55-75 ° C.) and the like.
One or two or more of these components (B) can be appropriately selected and used, but from the viewpoint of improving the resin flexural modulus, an epoxy resin represented by the following general formula (1a) (for example, NER) can be used. -7604, NER-7403) is preferable, and from the viewpoint of maintaining a balance between resin bending strength, elastic modulus, and breaking strain, the total sum of k and j is preferably 5 or more, and NER-7604 is particularly preferable.

In the equation, k and j represent mean values, k is in the range 1-10, and j is a real number in the range 0-10.

Further, as the component (B), an alicyclic epoxy resin represented by the following general formula (2) can be used. By this use, the resin flexural modulus and heat resistance can be further enhanced.

[In formula (2), R1 represents a p-valent organic group. p represents an integer of 1 to 20. q represents an integer of 1 to 50, and the sum of q in the equation (2) is an integer of 3 to 100. R2 represents either of the groups represented by the following formula (2a) or (2b). However, at least one of R2 in the formula (2) is a group represented by the formula (2a).
Examples of the alicyclic epoxy resin represented by the above general formula (2) include addition of 1,2-epoxy-4- (2-oxylanyl) cyclohexane of 2,2-bis (hydroxymethyl) -1-butanol. A product, EHPE3150 (manufactured by Daicel Corporation, softening point: 75 ° C.) can be mentioned.

Other epoxy resins that can be used as component (B) include hydroquinone diglycidyl ether (eg EX-203 (melting point 88 ° C.)), diglycidyl terephthalate (eg EX-711 (melting point 106 ° C.)), N-. Examples thereof include glycidyl phthalimide (for example, EX-731 (melting point 95 ° C.)) (all manufactured by Nagase ChemteX Corporation).

As the epoxy resin used as the component (B), at least one of the above-mentioned epoxy resins solid at 25 ° C. may be appropriately selected, but when an oxazolidone ring-shaped epoxy resin is used, it is particularly suitable for reinforcing fibers. The adhesiveness of the matrix resin tends to be good, and when the epoxy resin represented by the general formula (1) and the alicyclic epoxy resin are used, the balance between the resin bending strength, the elastic coefficient, and the breaking strain is particularly good. It tends to be excellent in and heat resistance is good.

The component (B) is preferably 5 parts by mass to 90 parts by mass with respect to 100 parts by mass of the total amount of all the epoxy resins contained in the epoxy resin composition of the present invention. This is a case where the amount of the component (B) is 5 parts by mass or more, the flexural modulus and heat resistance of the cured product of the epoxy resin composition of the present invention are increased, and this is used for the matrix resin of the fiber reinforced plastic. This is because the adhesion of the matrix resin to the reinforcing fibers tends to be enhanced. More preferably, it is 7 parts by mass or more. Further, by setting the amount of the component (B) to 90 parts by mass or less, the impregnation property of the resin in the manufacturing process of the prepreg is excellent, and the handleability (tack property, drape property, wrapping property around the mandrel) of the obtained prepreg is improved. This is because the physical properties of the fiber-reinforced composite material tend to be good as well as good. More preferably, it is 70 parts by mass or less.

"Component (C): Epoxy resin other than component (A) liquid at 25 ° C"
The epoxy resin composition of the present invention contains an epoxy resin liquid at 25 ° C. as a component (C).
This component (C) can easily control the viscosity of the epoxy resin composition within an appropriate range, adjusts the tackiness of the prepreg containing the epoxy resin composition, and is fiber-reinforced by this use. A molded product with few voids can be obtained during plastic production.

For example, as a bisphenol A type epoxy resin, this component (C) contains jER825 (viscosity at 25 ° C.: 40 to 70 poise), jER827 (viscosity at 25 ° C.: 90 to 110 poise), jER828 (viscosity at 25 ° C.). Viscosity: 120-150 poise) (above, manufactured by Mitsubishi Chemical Co., Ltd.), Epicron 830 (manufactured by DIC Co., Ltd., viscosity at 25 ° C.: 30-40 poise), jER806 (as a bisphenol F type epoxy resin) Viscosity at 25 ° C: 15-25 poise), jER807 (viscosity at 25 ° C: 30-45 poise) (above, manufactured by Mitsubishi Chemical Co., Ltd.), TETRAD-C (hydrated bisphenol A type epoxy resin) Mitsubishi Gas Chemicals Co., Ltd., viscosity at 25 ° C: 20-35 poise), Denacol EX-252 (Nagase Kasei Kogyo Co., Ltd., viscosity at 25 ° C: 22 poise), Denacol, a resorcindiglycidyl ether EX-201 (manufactured by Nagase Kasei Kogyo Co., Ltd., viscosity at 25 ° C: 2.5 poise), Denacol EX-721 (manufactured by Nagase Kasei Kogyo Co., Ltd., viscosity at 25 ° C), which is diglycidyl phthalate: 9. 8 poise), alicyclic epoxy resin Araldide CY177 (viscosity at 25 ° C: 6.5 poise), CY179 (viscosity at 25 ° C: 3.5 poise) (above, manufactured by Ciba Geigy Co., Ltd.), glycerin Denacol EX-314 (viscosity at 25 ° C), which is a triglycidyl ether, and Denacol EX-411 (viscosity at 25 ° C: 8.0 poise), which is a tetraglycidyl ether of pentaerythritol. Nagase Kasei Kogyo Co., Ltd., Tetraglycidyl m-xylylene diamine TETRAD-X (Mitsubishi Gas Chemicals Co., Ltd., viscosity at 25 ° C: 20-35 poisons), diglycidyl aniline GAN (25) Viscosity at ° C: 1.0-1.6 poise), o-toluidine diglycidylamine (viscosity at 25 ° C: 0.3-0.8 poise) (above, manufactured by Nippon Kayaku Co., Ltd.), Examples thereof include biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, tetraglycidyl diamine type epoxy resin, and glycidyl phenyl ether type epoxy resin. Further, an epoxy resin obtained by modifying these epoxy resins, a bromized epoxy resin obtained by bromizing these epoxy resins, and the like can be mentioned.

As the epoxy resin used as the component (C), as described above, one or more of the epoxy resins liquid at 25 ° C. may be appropriately selected. Among them, the bisphenol type bifunctional epoxy resin is used. It is preferable because the cured product has excellent heat resistance and does not have a sudden increase in viscosity even when the curing temperature is reached, and is excellent in suppressing voids during molding. Further, when all or part of the component (C) is a bisphenol F type epoxy resin, it is particularly preferable because it has an excellent flexural modulus.

The component (C) is preferably 20 parts by mass to 50 parts by mass with respect to 100 parts by mass of the total amount of all the epoxy resins contained in the epoxy resin composition of the present invention. This is because if the amount of the component (C) is 20 parts by mass or more, the viscosity of the epoxy resin composition of the present invention can be easily controlled within an appropriate range, and the tack of the prepreg containing the epoxy resin composition can be easily controlled. This is because there is a tendency that a molded product having less voids can be obtained when the properties are adjusted and the fiber reinforced plastic is manufactured. More preferably, it is 25 parts by mass or more. Further, by setting the amount of the component (C) to 50 parts by mass or less, an appropriate tack of the prepreg can be obtained, and the handleability tends to be good, and the resin bending elastic modulus and the resin bending fracture of the cured product tend to be improved. This is because the distortion tends to improve. More preferably, it is 45 parts by mass or less.

"Component (D): Hardener"
The epoxy resin composition of the present invention contains a curing agent as the component (D).
The type of the curing agent of the component (D) is not particularly limited, and examples thereof include amine-based curing agents, imidazoles, acid anhydrides, and boron chloride amine complexes. Of these, the use of dicyandiamide is preferable because the performance of the epoxy resin composition before curing does not change due to moisture, and curing can be completed at a relatively low temperature while maintaining long-term stability. The preferred blending amount of dicyandiamide is such that the number of moles of active hydrogen of dicyandiamide is 0.6 to 1.0 times the number of moles of epoxy groups derived from all the epoxy resins blended in the epoxy resin composition. Is preferable from the viewpoint that a cured product exhibiting good mechanical properties can be obtained. Further, it is more preferable that the value is 0.6 to 0.8 times because the heat resistance is excellent.

"Ingredient (E): Urea-based curing aid"
In the epoxy resin composition of the present invention, a urea-based curing aid may be further used as the component (E).
In particular, by using dicyandiamide as the component (D) and using the component (E): urea-based curing aid in combination, the epoxy resin composition can be cured in a short time even at a low temperature.
preferable.

Urea-based curing aids include 3-phenyl-1,1-dimethylurea (PDMU), toluenebisdimethylurea (TBDMU), 3- (3,4-dichlorophenyl) -1,1-dimethylurea (DCMU), etc. Urea derivative compounds include, but are not limited to. The urea-based curing aid may be used alone or in combination of two or more. In particular, 3-phenyl-1,1-dimethylurea and toluenebisdimethylurea have higher heat resistance and bending strength of the cured product of the epoxy resin composition, and the curing time of the epoxy resin composition is shorter. Is preferable. Further, by using 3-phenyl-1,1-dimethylurea or 3- (3,4-dichlorophenyl) -1,1-dimethylurea, the toughness of the cured product of the epoxy resin composition containing the same is particularly high. Therefore, it is preferable.

The blending amount of the component (E) is preferably 1 to 5 parts by mass with respect to 100 parts by mass of the total amount of the epoxy resin contained in the epoxy resin composition, from the viewpoint of obtaining a good cured product. Particularly preferably, it is 1.5 to 4 parts by mass.

"Thermoplastic resin"
The epoxy resin composition of the present invention can further contain a thermoplastic resin, if necessary. With this thermoplastic resin, there is a tendency that the resin bending fracture strain of the cured product can be improved.
Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, poly (methyl methacrylate) / poly (butyl acrylate) / poly (methyl methacrylate) triblock copolymer, and poly (styrene) / poly (butadiene) /. It can be appropriately selected from a triblock copolymer selected from poly (methyl methacrylate) and used, but by using a phenoxy resin or a polyvinyl acetal resin, the resin bending fracture strain and resin of the above-mentioned cured product can be used. There is a tendency that both bending elasticity can be achieved.

Examples of the phenoxy resin that can be used in the epoxy resin composition of the present invention include, but are limited to, bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, or phenoxy resin in which bisphenol A type and bisphenol F type are mixed. Not done. Further, two or more kinds of these phenoxy resins may be used in combination.

The mass average molecular weight of the phenoxy resin is preferably 50,000 to 80,000. When the mass average molecular weight of the phenoxy resin is 50,000 or more, it is possible to prevent the viscosity of the epoxy resin composition from becoming too low, and the viscosity of the epoxy resin composition can be easily adjusted to an appropriate viscosity range with an appropriate blending amount. it can. On the other hand, if the mass average molecular weight of the phenoxy resin is 80,000 or less, it can be dissolved in the epoxy resin, and it is possible to prevent the viscosity of the epoxy resin composition from becoming too high even with a very small amount of the epoxy resin. The viscosity of the composition can be easily adjusted to an appropriate viscosity range.

Specific examples of the phenoxy resin include YP-50, YP-50S, YP-70 (all trade names, manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), jER1256, jER4250, and jER4275 (all trade names, Mitsubishi Chemical Corporation). (Made) and so on.

Specific examples of the polyvinyl acetal resin include Vinilek K (average molecular weight: 59000), Vinilec L (average molecular weight: 66000), Vinilec H (average molecular weight: 73000), Vinilec E (average molecular weight: 126000) (all trade names, Polyvinyl formal (manufactured by Chisso Co., Ltd.), polyvinyl acetal such as Eslek K (manufactured by Sekisui Chemical Industry Co., Ltd.), Eslek B (manufactured by Sekisui Chemical Co., Ltd.) and Denka Butyral (manufactured by Electrochemical Industry Co., Ltd.) Such as polyvinyl butyral.

Specific examples of triblock copolymers include poly (methyl methacrylate) / poly (butyl acrylate) / poly (methyl methacrylate) triblock copolymers and poly (styrene) / poly (butadiene) / poly (methyl methacrylate). ) Triblock copolymer and the like. That is, a triblock copolymer in which poly (methyl methacrylate), poly (butyl acrylate), and poly (methyl methacrylate) are copolymerized in this order, or poly (styrene), poly (butadiene), and poly (methacrylic acid). Examples thereof include triblock copolymers in which methyl) is copolymerized in this order.

By selecting a polymer that is incompatible with the epoxy resin for the soft block in the center and a polymer that is easily compatible with the epoxy resin as one or both of the hard blocks, the triblock copolymer is microdispersed in the epoxy resin. To do. The polymer constituting the soft block has a lower glass transition temperature and better fracture toughness than the polymer constituting the hard block. Therefore, by microdispersing the triblock copolymer having this structure in the epoxy resin, it is possible to suppress a decrease in heat resistance of the cured product of the epoxy resin composition and improve fracture toughness.

The poly (methyl methacrylate) / poly (butyl acrylate) / poly (methyl methacrylate) triblock copolymer having hard blocks on both sides, which is a polymer that is easily compatible with the epoxy resin, has good dispersion in the epoxy resin. It is more preferable because the breaking toughness of the cured product of the epoxy resin composition can be greatly improved. Examples of commercially available poly (methyl methacrylate) / poly (butyl acrylate) / poly (methyl methacrylate) triblock copolymers include Nanostrength (registered trademark) M52, M52N, M22, and M22N (any of them). Also includes the product name, manufactured by Alchema Co., Ltd.).

As commercially available poly (styrene) / poly (butadiene) / poly (methyl methacrylate) triblock copolymers, for example, Nanostrength 123, 250, 012, E20, and E40 manufactured by Arkema Co., Ltd. (all of which are commercial products. First name) and so on.

The amount of the thermoplastic resin used in the epoxy resin composition of the present invention is in the range of 0.1 to 10 parts by mass with respect to 100 parts by mass of the total amount of all the epoxy resins contained in the epoxy resin composition. preferable. This is because when the amount of the thermoplastic resin used is 1 part by mass or more, the resin bending fracture strain of the cured product of the epoxy resin composition is high, and preferably, when it is 10 parts by mass or less, the epoxy resin composition is cured. This is because the flexural modulus of an object tends to be high. More preferably, it is 6 parts by mass or less.

"Other epoxy resins"
The epoxy resin composition of the present invention includes an epoxy resin other than the above-mentioned epoxy resin listed as any of the above-mentioned components (A), (B), and (C) as long as the effects of the present invention are not impaired. (Hereinafter, referred to as "other epoxy resin") may be contained.

Examples of other epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, glycidylamine type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, and modified epoxy thereof as bifunctional epoxy resins. Examples include resin. Examples of the trifunctional or higher functional epoxy resin include phenol novolac type epoxy resin, cresol novolac type epoxy resin, tetraglycidyl diamine type epoxy resin such as tetraglycidyl diaminodiphenylmethane, triglycidyl aminophenol, and tetrakis (glycidyl oxyphenyl) ethane. And tris (glycidyloxyphenyl) methane and other glycidylphenyl ether type epoxy resins. Further, examples thereof include an epoxy resin obtained by modifying these epoxy resins and a brominated epoxy resin obtained by bromizing these epoxy resins, but the present invention is not limited thereto. Further, two or more kinds of these epoxy resins may be combined and used as other epoxy resins.

The amount of "other epoxy resin" contained in the epoxy resin composition of the present invention is preferably 30 parts by mass or less with respect to 100 parts by mass of the total amount of all epoxy resins contained in the epoxy resin composition.

"Other additives"
The epoxy resin composition of the present invention contains one or more additives selected from the group consisting of thermoplastic resins other than the thermoplastic resins, thermoplastic elastomers, and elastomers as long as the effects of the present invention are not impaired. May be. With such an additive, the viscoelasticity of the epoxy resin composition of the present invention can be changed to optimize the viscosity, storage elastic modulus and thixotropic property, and the cured product of the epoxy resin composition of the present invention can be optimized. It can also improve toughness. The thermoplastic resin, thermoplastic elastomer or elastomer used as an additive may be used alone or in combination of two or more. Further, it may be dissolved in the epoxy resin component and blended, or may be contained in the epoxy resin composition in the form of fine particles, long fibers, short fibers, woven fabric, non-woven fabric, mesh, pulp and the like. When the additive is arranged on the surface layer of the prepreg in the form of fine particles, long fibers, short fibers, woven fabric, non-woven fabric, mesh, pulp, etc., it is preferable because delamination of the fiber reinforced plastic can be suppressed.

The thermoplastic resin comprises a carbon-carbon bond, an amide bond, an imide bond, an ester bond, an ether bond, a carbonate bond, a urethane bond, a urea bond, a thioether bond, a sulfone bond, an imidazole bond and a carbonyl bond in the main chain. Thermoplastic resins with bonds selected from the group are preferably used, such as, for example, polyacrylates, polyamides, polyaramids, polyesters, polycarbonates, polyphenylene sulfides, polybenzimidazoles, polyimides, polyetherimides, polysulfones and polyether sulfones. A group of thermoplastic resins belonging to engineering plastics is more preferably used. Polyimide, polyetherimide, polysulfone, polyethersulfone and the like are particularly preferably used because of their excellent heat resistance. Further, it is preferable that these thermoplastic resins have a functional group reactive with the epoxy resin from the viewpoint of improving the toughness of the cured resin of the resin composition of the present invention and maintaining the environmental resistance. Preferred functional groups with reactivity with the epoxy resin include carboxyl groups, amino groups and hydroxyl groups.

The epoxy resin composition of the present invention preferably satisfies the following (1), (2) and (3).

[Physical properties]
(1) The flexural modulus of the cured product of the epoxy resin composition is 3.7 GPa or more (2) The bending breaking strain of the cured product of the epoxy resin composition is 8% or more (3) The cured product of the epoxy resin composition And a fiber reinforced plastic made of a reinforced fiber base material in which medium elastic and high elastic carbon fibers, which are continuous fibers, are aligned in one direction.
0 ° bending strength (MPa)
When using medium elastic carbon fiber: 1700 MPa or more
When using highly elastic carbon fiber: 1600 MPa or more 90 ° bending strength (MPa)
When using medium elastic carbon fiber: 135 MPa or more
When using highly elastic carbon fiber: 100 MPa or more

In the cured product of the epoxy resin composition, there is a trade-off relationship between the improvement of the flexural modulus and the improvement of the bending fracture strain, but as a result of diligent studies, the present inventors have determined that both physical properties are controlled within a specific range. We found that they are compatible at a high level. By using such an epoxy resin composition, the breaking strength of the obtained fiber reinforced plastic can be improved.

Further, controlling the ratio of the 0 ° bending strength to the 90 ° bending strength of the fiber reinforced plastic measured under the conditions described later within a specific range is more effective in improving the fracture strength of the obtained fiber reinforced plastic. I found that. By expressing the bending strength and the bending rigidity in the 0 ° direction and the bending strength which is an index of the peel strength in the 90 ° direction at a high level, it is possible to develop a high strength as a tubular body.

Furthermore, it was not possible to achieve a balance between 0 ° bending strength and 90 ° bending strength of fiber reinforced plastic and bending fracture strain with conventional techniques, but it is high by controlling these within a specific range. We found that they are compatible at the level. It has been found that the breaking strength of the obtained fiber reinforced plastic can be remarkably improved by using such an epoxy resin composition.

The details will be described below.

(1) Resin flexural modulus of 3.7 GPa or more The resin flexural modulus in the present invention is a value measured by the following method.

A cured resin plate having a thickness of 2 mm obtained by curing the epoxy resin composition is processed into a test piece (length 60 mm × width 8 mm), and using an INSTRON 4465 measuring machine equipped with a 500 N load cell, the temperature is 23 ° C. and the humidity is 50. Using a 3-point bending jig (indenter R = 3.2 mm, support R = 3.2 mm) in an environment of% RH, the ratio L / d = 16 of the distance between supports (L) and the thickness (d) of the test piece. Bend the test piece under the conditions of and measure the elastic modulus.

When an epoxy resin composition having a resin flexural modulus of 3.7 MPa or more is used as a matrix resin of fiber reinforced plastic, a high 0 ° bending strength can be obtained. Further, when the fiber reinforced plastic is tubular, high bending strength of the tubular body can be obtained.

The resin flexural modulus may be 3.7 GPa or more, but more preferably 3.9 GPa or more because higher 0 ° bending strength and 90 ° bending strength can be obtained. The upper limit of the resin flexural modulus is not particularly limited, but is usually 6.0 GPa or less.

(2) Resin bending fracture strain is 8% or more The resin bending fracture strain is a value measured by the following method.

A cured resin plate having a thickness of 2 mm obtained by curing the epoxy resin composition is processed into a test piece (length 60 mm × width 8 mm), and using an INSTRON 4465 measuring machine equipped with a 500 N load cell, the temperature is 23 ° C. and the humidity is 50. Using a 3-point bending jig (indenter R = 3.2 mm, support R = 3.2 mm) in an environment of% RH, the ratio of the distance between supports (L) to the thickness (d) of the test piece L / d = 16 Bend the test piece under the conditions of (1) to obtain strain at maximum load and fracture strain. The resin plate may not break in the resin bending test. In that case, the device is stopped when it exceeds 13%, and the value is taken as the breaking strain.

When an epoxy resin composition having a resin bending fracture strain of 8% or more is used for a matrix resin of a fiber reinforced plastic, a high 90 ° bending strength can be obtained. Further, when the fiber reinforced plastic is tubular, high bending strength of the tubular body can be obtained.

The resin bending fracture strain may be 8% or more, but 11% or more is more preferable because a higher 90 ° bending strength can be obtained. More preferably, it is 12% or more. The upper limit of the resin bending fracture strain is 13% as is clear from the above-mentioned measurement method.

(3) A fiber-reinforced plastic made of a cured product of the epoxy resin composition and a reinforcing fiber base material in which carbon fibers, which are continuous fibers, are aligned in one direction.
0 ° bending strength (MPa)
When using medium elastic carbon fiber: 1700 MPa or more
When using highly elastic carbon fiber: 1600 MPa or more 90 ° bending strength (MPa)
When using medium elastic carbon fiber: 135 MPa or more
When using highly elastic carbon fiber: 100 MPa or more The 0 ° bending strength and 90 ° bending strength of the above fiber reinforced plastics are such that the carbon fibers are aligned in one direction, the fiber grain is 125 g / m2, and the resin content is It is a value measured by the following method for the fiber reinforced plastic panel produced by producing 28% by mass of a prepreg and curing it.

(0 ° bending strength)
The obtained fiber-reinforced plastic panel is processed into a test piece (length 127 mm × width 12.7 mm) so that the reinforcing fibers are oriented at 0 ° with respect to the longitudinal direction of the test piece, and is a universal testing machine manufactured by Instron. In an environment of temperature 23 ° C. and humidity 50% RH, using a three-point bending jig (indenter R = 5 mm, support R = 3.2 mm), the distance between supports (L) and the thickness of the test piece (d). The test piece is bent under the conditions of the ratio L / d = 40 and the cross head speed (minute speed) = (L × L × 0.01) / (6 × d), and the bending strength and the breaking strain are measured.

(90 ° bending strength)
The obtained fiber-reinforced plastic panel is processed into a test piece (length 60 mm x width 12.7 mm) so that the reinforcing fibers are oriented at 90 ° with respect to the longitudinal direction of the test piece, and a universal test manufactured by Instron is performed. Using a machine, in an environment of temperature 23 ° C. and humidity 50% RH, using a three-point bending jig (indenter R = 5 mm, support R = 3.2 mm), the distance between supports (L) and the thickness of the test piece (d) ), The cross head speed (minute speed) = (L × L × 0.01) / (6 × d), the test piece is bent, and the bending strength and the breaking strain are measured.

Of fiber reinforced plastic
When 0 ° bending strength (MPa) is medium elastic carbon fiber: 1700 MPa or more When high elastic carbon fiber is used: 1600 MPa or more When 90 ° bending strength (MPa) is medium elastic carbon fiber: When carbon fiber having high elasticity of 135 MPa or more is used: When 100 MPa or more, high bending strength of the tubular body can be obtained in the tubular fiber reinforced plastic. Of fiber reinforced plastic
When 0 ° bending strength (MPa) is medium elastic carbon fiber: 1800 MPa or more When high elastic carbon fiber is used: 1700 MPa or more When 90 ° bending strength (MPa) is medium elastic carbon fiber: When carbon fiber having high elasticity of 140 MPa or more is used: 105 MPa or more is more preferable.
When either the 0 ° bending strength or the 90 ° bending strength of the fiber reinforced plastic is high and the other is low, the balance of performance expression as a tubular body tends to be lowered.

The epoxy resin composition of the present invention can be applied to a paper pattern or the like to obtain a resin film. The film of the present invention is useful as an intermediate material for producing a prepreg, and as a surface protective film or an adhesive film by being attached to a substrate and cured.

Further, a prepreg can be obtained by impregnating the reinforcing fiber base material with the epoxy resin composition of the present invention. The reinforcing fiber base material that can be used for the prepreg of the present invention is not limited, and carbon fiber, graphite fiber, glass fiber, organic fiber, boron fiber, steel fiber and the like can be used, and tow, cloth, chopped fiber and continuous fiber can be used. A form in which the toes are aligned in a direction, a form in which continuous fibers are used as warp and weft, a form in which the toe is aligned in one direction and held by a weft auxiliary thread, and a plurality of sheets of unidirectional reinforcing fibers are stacked in different directions to assist Examples include a form in which a multiaxial warp knit is stitched with a thread and fastened, and a form in which reinforcing fibers are used as a non-woven fabric.

As the reinforcing fibers constituting these reinforcing fiber base materials, carbon fibers and graphite fibers have a good specific elastic modulus and a great effect on weight reduction, and thus can be suitably used for the prepreg of the present invention. In addition, any kind of carbon fiber or graphite fiber can be used depending on the application.

The epoxy resin composition of the present invention can be suitably used for any reinforcing fiber. In particular, it can be suitably used for carbon fibers, and further, it can be preferably used for medium-elasticity and high-elasticity carbon fibers.

Further, by shaping and curing the prepreg of the present invention, a fiber-reinforced plastic containing a cured product of the epoxy resin composition and reinforcing fibers can be obtained. There are no restrictions on the use of the fiber reinforced plastic, and it can be used for structural materials for aircraft, automobiles, ships, sports, and other general industrial applications such as wind turbines and rolls. As a method for producing fiber reinforced plastic, a molding method in which a sheet-shaped molding intermediate called prepreg is processed to perform autoclave molding, sheet wrap molding, press molding, etc., or an epoxy resin composition for filaments and preforms of reinforcing fibers. Molding methods such as RTM, VaRTM, filament winding, and RFI that impregnate an object and cure to obtain a molded article can be mentioned, but are not limited to these molding methods.

The fiber-reinforced plastic of the present invention can be particularly preferably used for a golf club shaft or the like utilizing high breaking strength by making it tubular.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples.

<Raw materials>
Ingredient (A):
MY0510 (trade name): Triglycidyl-p-aminophenol type epoxy resin, epoxy equivalent 101 g / eq
MY0600 (trade name): Triglycidyl-m-aminophenol type epoxy resin, epoxy equivalent 105 g / eq

Ingredient (B):
NER-7604 (trade name): Polyfunctional bisphenol F type epoxy resin, epoxy equivalent 350 g / eq, softening point 70 ° C, AER4152 manufactured by Nippon Kayaku Co., Ltd. (trade name "Araldite AER4152"): Oxazolidene ring in the skeleton Bifunctional epoxy resin with, number average molecular weight 814, softening point: 79 ° Asahi Kasei E-Materials Co., Ltd. jER1001 (trade name): bisphenol A type bifunctional epoxy resin, epoxy equivalent 450-500 g / eq, number average molecular weight 900, Softening point: 64 ° C JER1004 manufactured by Mitsubishi Chemical Co., Ltd. (trade name): Bisphenol A type bifunctional epoxy resin, epoxy equivalent 875-975 g / eq, number average molecular weight 1650, softening point: 97 ° C EHPE3150 manufactured by Mitsubishi Chemical Co., Ltd. (Product name): Solid alicyclic epoxy resin, softening point: 75 ° C, manufactured by Daicel Co., Ltd.

Ingredient (C):
jER828 (trade name): bisphenol A type bifunctional epoxy resin, epoxy equivalent 189 g / eq, manufactured by Mitsubishi Chemical Corporation jER807 (trade name): bisphenol F type bifunctional epoxy resin, epoxy equivalent 167 g / eq, Mitsubishi Chemical Corporation ) Made

Ingredient (D):
DICY15 (trade name): dicyandiamide (abbreviation: DICY), manufactured by Mitsubishi Chemical Corporation

Ingredient (E):
DCMU99 (trade name): 3- (3,4-dichlorophenyl) -1,1-dimethylurea (abbreviation: DCMU), Hodogaya Chemical Co., Ltd. Omicure94 (trade name): 3-phenyl-1,1- Dimethylurea (abbreviation: PUMU), manufactured by PTI Japan Co., Ltd.

Thermoplastic resin:
Vinilec E (trade name): Polyvinylformal resin, manufactured by Chisso Co., Ltd. YP-50S (trade name): Phenoxy resin, mass average molecular weight 50,000 to 70,000, manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd. M52N (trade name " Nanostrength M52N "): Acrylic block copolymer (poly (methyl methacrylate) / poly (butyl acrylate) / poly (methyl methacrylate) triblock copolymer, further copolymerized with dimethyl acrylamide, Alchema Co., Ltd." Made

[Examples 1 to 12, Comparative Examples 1 to 7]
An epoxy resin composition was prepared by the following procedure, and the resin flexural modulus, resin bending fracture strain, and bending strength of the fiber reinforced plastic were measured using the epoxy resin composition. Table 1 shows the resin composition and the measurement (evaluation) results.

<Preparation of catalyst resin composition>
A catalyst resin composition is prepared by uniformly dispersing the components (D) and (E) shown in the same table in a part of the liquid epoxy resin components contained in the resin composition shown in Table 1 with a three-roll mill. did.

<Preparation of epoxy resin composition>
A uniform master by heating and mixing a part of the solid epoxy resin component contained in the resin composition shown in Table 1, a part of the rest of the liquid epoxy resin component, and the thermoplastic resin at 160 ° C. A batch (1) was obtained.

After cooling the obtained masterbatch (1) to 120 ° C., the rest of the solid epoxy resin component was added thereto and mixed at 120 ° C. to uniformly disperse the masterbatch (2). ..

After cooling the obtained masterbatch (2) to 60 ° C., the remainder of the catalyst resin composition and the liquid epoxy resin component prepared in advance are weighed and added, and the mixture is uniformly mixed at 60 ° C. The epoxy resin composition was obtained.

<Manufacturing of cured resin plate>
The epoxy resin composition obtained in the above <Preparation of Epoxy Resin Composition> is sandwiched between glass plates together with a spacer made of polytetrafluoroethylene having a thickness of 2 mm, and the temperature is raised at a heating rate of 2 ° C./min. A cured resin plate was obtained by holding at 130 ° C. for 90 minutes and curing.

<Measurement of resin flexural modulus and resin bending fracture strain>
The cured resin plate having a thickness of 2 mm obtained in the above-mentioned <Preparation of cured resin plate> is processed into a test piece (length 60 mm × width 8 mm), and the temperature is 23 using an INSTRON 4465 measuring machine equipped with a 500 N load cell. Using a three-point bending jig (indenter R = 3.2 mm, support R = 3.2 mm) in an environment of ° C. and humidity of 50% RH, the ratio L of the distance between supports (L) and the thickness (d) of the test piece is L. The test piece was bent under the condition of / d = 16 to obtain elastic modulus, strain at maximum load, and breaking strain. The results are shown in Table 1.

If the resin plate did not break in the resin bending test, the apparatus was stopped when it exceeded 13%, and the value was taken as the breaking strain.

In Examples 1 to 12, the resin flexural modulus was 3.7 GPa or more and the breaking strain was 8% or more.
On the other hand, in Comparative Examples 1 to 7, either the resin flexural modulus of 3.7 GPa or more or the breaking strain of 8% or more was not achieved.

<Composite (fiber reinforced plastic) panel manufacturing method>
The epoxy resin compositions of Examples 1 and 4 and Comparative Examples 1 and 5 obtained in the above <Preparation of Epoxy Resin Composition> are heated to 60 ° C. and applied to a release paper with a film coater to form a resin. A film was made. The thickness of the resin film was set so that the resin content of the prepreg was 28% by mass when two prepregs were produced using the two resin films as described later.

Carbon fibers (manufactured by Mitsubishi Rayon Co., Ltd., MR70-12P as medium elastic carbon fibers and HR40-12M as high elastic carbon fibers) are placed on this resin film (the surface of the release paper on the resin film forming side) with a fiber grain of 125 g / It was wound with a drum wind device so as to form an m2 sheet. Yet another resin film was laminated on the carbon fiber sheet on the drum wind device. Fusing press (Asahi Textile Machinery Co., Ltd., JR-600LTSW, processing length 1340 mm, pressure) under the conditions of temperature 100 ° C, pressure 0.4 MPa, feed rate 3 m / min, and carbon fiber sheet sandwiched between two resin films. Was passed through the cylinder pressure) to obtain a prepreg having a fiber grain of 125 g / m2 and a resin content of 28% by mass.

Eighteen of the obtained prepregs were laminated, heated in an autoclave at a pressure of 0.04 MPa at 2 ° C./min, held at 80 ° C. for 60 minutes, then further heated at 2 ° C./min, and raised to 130 ° C. It was warmed and heat-cured under a pressure of 0.6 MPa for 90 minutes to obtain a fiber-reinforced plastic panel.

<Measurement of composite (fiber reinforced plastic) bending strength>
The fiber-reinforced plastic panel obtained by the above <method for producing a fiber-reinforced plastic panel> is subjected to the following test pieces so that the reinforcing fibers are oriented at 0 ° or 90 ° with respect to the longitudinal direction of the test piece. Processed to size, using a universal testing machine manufactured by Instron, using a three-point bending jig (indenter R = 5 mm, support R = 3.2 mm) in an environment of temperature 23 ° C. and humidity 50% RH, The ratio L / d of the distance between supports (L) and the thickness (d) of the test piece is tested under the conditions of crosshead speed (minute speed) = (L2 × 0.01) / (6 × d) under the following conditions. The pieces were bent to obtain bending strength, elastic modulus and breaking strain at 0 ° and 90 °. The 0 ° bending characteristic was converted to Vf60%. The results are shown in Table 2.

For 0 ° bending characteristic evaluation: length 100 mm x width 12.7 mm, L / d = 40
For evaluation of 90 ° bending characteristics: length 60 mm x width 12.7 mm, L / d = 16

<Molding of tubular body (pipe-shaped fiber reinforced plastic)>
Frecoat NC700 (manufactured by Tomoe Engineering Co., Ltd.) was applied as a mold release agent to a core material of 6 mmφ made of SUS. The above prepreg using MR70-12P as the reinforcing fiber was cut so that the arrangement direction of the fiber was oriented in the plus 45 ° direction, the minus 45 ° direction, and the 0 ° direction with respect to the axial direction of the core material.
First, one layer of the prepreg in the plus 45 ° direction was wound around the core material, and then one layer was wound in the minus 45 ° direction. These were alternately laminated and wound as a ± 45 ° layer for a total of 7 turns. A 0 ° layer is wound around the outer circumference for three turns. A total of 10 weeks' worth of prepreg was wrapped. A PP wrapping tape was wrapped so that the traverse pitch was about 10 mm. In the heating device, the temperature was raised at a heating rate of 2 ° C./min, and the temperature was maintained at 130 ° C. for 90 minutes to cure. After heating, the tube was decentered to obtain a tubular body.

<Evaluation method for tubular body (pipe-shaped fiber reinforced plastic)>
In accordance with the SG bending test method, use a jig (distance between supports (L): 150 mm, indenter R = 75 mm, support R = 12.5), and perform a bending test at crosshead speed (minute speed) = 20 mm / min. Implementation. The maximum breaking load was obtained. The results are shown in Table 2.

The 0 ° bending strength of the fiber reinforced plastics of Examples 1 and 4 was 1700 MPa or more when medium elastic carbon fibers were used, and 1600 MPa or more when high elastic carbon fibers were used. However, in Comparative Example 1 and Comparative Example 5, the 0 ° bending strength in each case was less than 1600 MPa.
The 90 ° bending strength of the fiber reinforced plastics of Examples 1 and 4 is 135 MPa or more when medium elastic carbon fibers are used, and 100 MPa or more when high elastic carbon fibers are used. However, in Comparative Example 1 and Comparative Example 5, this criterion was not achieved in any case.
Further, the maximum breaking load of the tubular body in Examples 1 and 4 was much higher than that of Comparative Examples 1 and 5.

By using the epoxy resin composition of the present invention, an excellent tubular fiber reinforced plastic can be obtained. Therefore, according to the present invention, it is possible to provide a wide range of fiber-reinforced plastic molded articles having excellent mechanical properties, from molded articles for sports and leisure applications such as shafts for golf clubs to molded articles for industrial applications such as aircraft.

Claims (16)

An epoxy resin composition containing the following components (A), (B), (C) and (D).
Component (A) Trifunctional epoxy resin Component (B) Epoxy resin represented by the following general formula (1) other than the component (A) solid at 25 ° C. Component (C) Other than the component (A) that is liquid at 25 ° C. Epoxy resin component (D) curing agent
In the formula, n and m represent average values, n is a real number in the range of 1 to 10, m is a real number in the range of 0 to 10, and R ₁ and R ₂ are independently hydrogen atoms and carbon atoms 1, respectively. Shows an alkyl group or trifluoromethyl group having ~ 4 pieces. The epoxy resin composition according to claim 1, wherein the component (B) contained in the epoxy resin composition has an epoxy equivalent of 500 or less. The epoxy resin composition according to claim 1 or 2, wherein the component (C) contained in the epoxy resin composition has an epoxy equivalent of 500 or less. The epoxy resin composition according to any one of claims 1 to 3, wherein the component (B) is an epoxy resin having a softening point or a melting point of 50 ° C. or higher. The epoxy resin composition according to any one of claims 1 to 4, wherein the component (B) is an epoxy resin having a softening point or a melting point of 150 ° C. or lower . The epoxy resin composition according to any one of claims 1 to 5, which contains an alicyclic epoxy resin represented by the following general formula (2) as the component (B).
[In formula (2), R ¹ represents a p-valent organic group. p represents an integer of 1 to 20. q represents an integer of 1 to 50, and the sum of q in the equation (2) is an integer of 3 to 100. R ² represents either of the groups represented by the following formula (2a) or (2b). However, at least one of R ^{2 in} the formula (2) is a group represented by the formula (2a).
The epoxy resin according to claim 6, wherein the alicyclic epoxy resin contains a 1,2-epoxy-4- (2-oxylanyl) cyclohexane adduct of 2,2-bis (hydroxymethyl) -1-butanol. Composition. The epoxy according to any one of claims 1 to 7, wherein the content of the component (B) is 5 parts by mass to 90 parts by mass with respect to 100 parts by mass of the total amount of the epoxy resin contained in the epoxy resin composition. Resin composition. The epoxy resin composition according to any one of claims 1 to 8, wherein the component (C) is a bisphenol type epoxy resin . The epoxy according to any one of claims 1 to 9, wherein the content of the component (C) is 20 parts by mass to 50 parts by mass with respect to 100 parts by mass of the total amount of the epoxy resin contained in the epoxy resin composition. Resin composition. The epoxy resin composition according to any one of claims 1 to 10, wherein the component (D) is dicyandiamide. The epoxy resin composition according to any one of claims 1 to 11, further comprising a urea-based curing aid as the component (E). A film comprising the epoxy resin composition according to any one of claims 1 to 12. A prepreg in which a reinforcing fiber base material is impregnated with the epoxy resin composition according to any one of claims 1 to 12 . A fiber-reinforced plastic comprising a cured product of the epoxy resin composition according to any one of claims 1 to 12 and reinforcing fibers. The fiber reinforced plastic according to claim 15, which is tubular.