JPH09157498A - Epoxy resin composition for fiber-reinforced composite material, prepreg and fiber-reinforced composite material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition for fiber-reinforced composite material which contains an epoxy resin, particles containing an amine and a boric ester, and shows excellent storage stability, handleability and economy and is useful in structural materials for air crafts or sport gears. SOLUTION: This composition contains (A) an epoxy resin, (B) an amine with an average particle size of <=10μm, preferably an imidazole derivative, and (C) a boric ester. In the component B, the distribution of particles of >=20μm is preferably less than 10% and the content of the amine in the particles is preferably >=5wt.%, particularly 20-80wt.%. The objective composition is obtained by pre-treating the component B with the component C on its surface and kneading the treated product together with the component A and, when necessary, other raw materials.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a reinforcing fiber such as carbon fiber, glass fiber and aramid fiber and an epoxy resin composition used for structural materials such as aircrafts, vehicles, ships and constructions, sports equipment and the like. The present invention relates to a fiber-reinforced composite material.

[0002]

2. Description of the Related Art Epoxy resins are excellent in various properties such as mechanical properties, electrical properties, thermal properties, chemical resistance, adhesiveness, etc. of their cured products. It is used in various fields such as insulating materials and adhesives. The epoxy resin composition starts the reaction by mixing an uncured epoxy resin with a curing agent or a curing accelerator, so it is common to store these separately and mix them immediately before use. Target. Recently, there has been an increasing demand for a one-pack type because it is easy to handle due to diversified applications.

Particularly, in a fiber-reinforced composite material comprising a matrix resin and reinforcing fibers such as carbon fibers, glass fibers and aramid fibers, a prepreg which is an intermediate base material in which the reinforcing fibers are previously impregnated with a matrix resin is often used.
In many cases, the prepreg is laminated and then cured to mold the material. A one-pack type epoxy resin composition is often used as a matrix resin. For example, a latent curing agent such as dicyandiamide, a hydrazide compound, or a boron trifluoride compound is used for the epoxy resin, and a curing agent such as a urea compound or an imidazole compound is used. Used in combination with accelerators. However, none of these can sufficiently withstand long-term storage, and since the resin and curing agent are reactive even at room temperature, tackiness or tackiness, which is an important property of prepreg, and drapeability Flexibility decreases over time. Therefore, store the prepreg in the freezer,
At present, it is being used by devising measures such as shortening the time of leaving it at room temperature even before molding.

Under these circumstances, development of an epoxy resin composition and a prepreg having excellent storage stability at room temperature is desired, and for example, the surface of an epoxy curing agent is coated with a substance having no reactivity with the epoxy resin. Micro-encapsulation is being actively attempted. In order to use microcapsules for composite materials, the particle size needs to be 10 μm or less. If it exceeds 10 μm, the microcapsules are separated by filtration by the reinforcing fibers and cannot be sufficiently impregnated into the reinforcing fibers, which may cause curing failure or deterioration of the physical properties of the cured product.
However, few microcapsules having a particle size of 10 μm or less that can realize sufficient storage stability and curability have not been obtained.

[0005]

DISCLOSURE OF THE INVENTION The present invention solves the above problems, that is, provides an epoxy resin composition and a prepreg having good storage stability and curability, and a matrix resin having the epoxy resin composition. An object is to provide a fiber-reinforced composite material having excellent physical properties by using a material.

[0006]

In order to solve the above problems, the epoxy resin composition for fiber reinforced composite materials of the present invention is characterized by containing the following components. A: Epoxy resin B: Particles containing an amine compound having an average particle size of 10 μm or less C: Borate ester compound

The above epoxy resin composition may contain one or more components selected from a curing agent, a thermoplastic resin, an elastomer, a thermoplastic elastomer, and inorganic particles, which are accelerated or catalyzed by an amine compound. Good.

The prepreg of the present invention is a prepreg characterized by comprising the above epoxy resin composition and a reinforcing fiber.

Furthermore, the fiber-reinforced composite material of the present invention comprises reinforcing fibers and a matrix resin, and the matrix resin is a cured product of the above epoxy resin composition.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. As the epoxy resin used in the epoxy resin composition of the present invention, a compound having a plurality of epoxy groups in the molecule is used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, novolac type epoxy resin,
Epoxy resin having fluorene skeleton, epoxy resin made from copolymer of phenol compound and dicyclopentadiene, diglycidyl resorcinol, tetrakis (glycidyloxyphenyl) ethane, glycidyl ether type epoxy such as tris (glycidyloxyphenyl) methane Resin compositions, tetraglycidyldiaminodiphenylmethane, triglycidylaminophenol, triglycidylaminocresol, glycidylamine type epoxy resins such as tetraglycidylxylenediamine and mixtures thereof can be used.

The particles containing the amine compound which is the component B of the epoxy resin composition of the present invention are particles comprising the amine compound alone or the amine compound and other components, and are solid at room temperature A resin that is almost insoluble in resin is used. The presence of the borate ester of component C in the epoxy resin composition causes the amine compound to form a complex with the borate ester on the particle surface, and loses its activity as a curing agent or curing catalyst. As a result, the storage stability of the prepreg can be significantly improved.

When the amine compound is solid at room temperature and almost insoluble in the epoxy resin, it can be used as it is.
In addition, it is also possible to use particles obtained by combining the amine-based compound with another component, for example, another component such as a thermoplastic resin, a thermosetting resin, or an inorganic substance, which satisfies the above conditions.

When the amine compound and the thermoplastic resin or the thermosetting resin are combined, a solid solution of both, a structure in which a phase rich in the amine compound is dispersed in the resin, or a capsule in which the phase rich in the amine compound is coated with the resin There may be a mold structure or the like, but any structure may be adopted.

The particles composed of the amine compound and the thermoplastic resin or the thermosetting resin can be manufactured by various methods. Examples will be given below, but the present invention is not limited thereto.

The first is a method in which a solid solution or a mixture of an amine compound and a resin is produced by some method, and this is pulverized.

The second method is a method of preparing an emulsion in which an amine compound and a resin and a solvent, or an amine compound and a resin precursor are dispersed in a dispersion medium, followed by desolvation or polymerization or curing to obtain particles. By using this method, particles having a controlled particle size can be easily obtained. Further, by using appropriate conditions, particles having a microcapsule type structure can be obtained.

The third method is to form a resin coating on the surface of the amine compound powder. A resin film is formed by coating with a resin solution or polymerizing on the particle surface. In this method, the particles are of the microcapsule type.

It is preferable to use a thermoplastic resin as the resin to be combined with the amine compound, because it has the effect of improving the toughness of the resin after curing. When an amine compound and a thermoplastic resin are combined, a resin that softens or dissolves in the epoxy resin at the curing temperature of the epoxy resin composition is preferably used. In particular, although the resin itself has a high softening point, it is most preferable to use a resin that dissolves in the epoxy resin at the curing temperature, because the heat resistance of the epoxy resin is not impaired. As such a resin, for example, polysulfone or polyetherimide can be used.

A method of combining with an inorganic substance is also possible.
For example, a method of pulverizing a mixture of an amine compound and inorganic fine particles, a method of adsorbing inorganic fine particles on the surface of an amine compound for coating, a method of embedding an amine compound in inorganic hollow particles, a porous mineral such as zeolite. There is a method of adsorbing amine compound molecules between the vacancy or between layers of layered minerals such as montmorillonite.

When the amine compound and other components are combined, the content of the amine compound in the particles is preferably 5% by weight or more, more preferably 20% by weight to 80% by weight.

When a composite material is produced by using a resin composition containing the amine compound as a matrix resin, particles having a large particle size do not enter the reinforcing fiber, so that the particle containing the amine compound is contained in the reinforcing fiber bundle. The amount of the curing agent is reduced, and the curing is partially insufficient. Such a phenomenon is not preferable because it causes deterioration of physical properties of the composite material after curing. Therefore, in the present invention, the particles containing an amine compound need to have an average particle size of 10 μm or less, and preferably 5 μm or less. Here, the average particle diameter means a volume average. Further, it is preferable that the number of coarse particles is small, and specifically, it is preferable that particles having a particle size of 20 μm or more have a particle size distribution in which the volume fraction is 10% or less. A laser diffraction type particle size distribution measuring device is preferably used for measuring the average particle size and the particle size distribution.

As amine compounds, primary amines, 2
An organic compound having a structure selected from a primary amine, a tertiary amine, an imine, and a heterocycle containing a basic nitrogen is used.
Specific examples thereof include, but are not limited to, the following compounds.

Aliphatic amines such as: Ethylenediamine, propylenediamine, hexamethylenediamine,
2,5-dimethyl-2,5-hexanediamine, 2,
2,4-trimethylhexamethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, 4-aminomethyloctamethylenediamine, 3-dimethylaminopropylamine, 3-diethylaminopropylamine, mentenediamine, isophoronediamine , Aminoethylethanolamine, methyliminobispropylamine, bis (4-aminocyclohexyl) methane. Alternatively, a high molecular type such as polyaminoamide.

Aromatic amines such as: 4,4'-diaminodiphenylmethane, 3,3'-diethyl 4,4 '
-Diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, m-phenylenediamine, diaminotoluene, xylylenediamine, dimethylbenzylamine, tris (dimethylaminomethyl) phenol. Alternatively, a polymer type such as a polymer of an aniline derivative and formaldehyde.

The imine is obtained by reacting a primary amine with an aldehyde or a ketone. Usually ketimines obtained by reaction with ketones are mainly used.

Examples of the heterocyclic ring containing a basic nitrogen include pyridine, piperidine, piperazine, pyrrole, pyrrolidine,
Pyroline, imidazole, imidazolidine, imidazoline, pyrazole, oxazole, oxazoline, pyrazine, pyrimidine, indole, purine, quinoline, quinoxaline, quinuclidine, morpholine, 1,4-diazabicyclo [2,2,2] octane, 1,8-diazabicyclo [5,4,0] undecane and the like can be mentioned, and these and derivatives of these substituents can be used. Further, a high molecular type such as polyvinyl pyridine can also be used.

Of these amine compounds, compounds having active hydrogen on the nitrogen atom, such as primary amine and secondary amine, undergo an addition reaction with the epoxy resin to generate active hydrogen like tertiary amine. A compound having a deficient tertiary nitrogen atom undergoes a catalytic reaction with an epoxy resin.

The amine compound not only acts as a curing agent by itself, but also acts as a curing accelerator or a curing catalyst for other curing agents for epoxy resins. When used as a curing accelerator or a curing catalyst, the amine compound is preferably one having no active hydrogen on the nitrogen atom. Examples of the curing agent for an epoxy resin that is subjected to an acceleration action or a catalytic action by an amine compound include dicyandiamide, phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, Anhydride-based curing agents such as methyl hymic acid anhydride, adipic acid dihydrazide, hydrazide-based curing agents such as naphthalene dicarboxylic acid dihydrazide, novolac resins, trishydroxyphenylmethane, 1,1,1-trishydroxyphenylethane,
A phenol-based curing agent such as 1,1,2,2-tetrakishydroxyphenylethane or a mercaptan-based curing agent such as a mercaptopropionic acid ester or a thioglycolic acid ester can be used, and is compounded in the epoxy resin composition of the present invention. be able to.

As an amine compound that can be used alone as a curing agent or as a curing catalyst for other curing agents, there is an imidazole derivative having a substituent at the 1-position. The imidazole derivative having a substituent at the 1-position has high reactivity and is capable of low temperature curing and rapid curing, and has favorable properties such as excellent heat resistance and low water absorption of the cured product, Since the storage stability is impaired due to its high temperature, it has hardly been used in a one-pack type epoxy resin composition for composite materials. However,
When an imidazole derivative having a substituent at the 1-position is used as the amine compound of the epoxy resin composition for composite materials of the present invention, a composition exhibiting extremely excellent storage stability can be obtained.

As the imidazole derivative having a substituent at the 1-position, specifically, an imidazole derivative represented by the following formula 2 is preferable.

[0031]

Embedded image

In the formula, R _{1 and} R ₂ each represent an alkyl group, an aryl group or an aralkyl group which is unsubstituted or has one or more substituents selected from halogen, a hydroxyl group and a cyano group, and R _{3 to} R ₄ Is unsubstituted or halogen, hydroxyl group,
It represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom having one or more substituents selected from a cyano group.

Here, the alkyl group means a substituent derived from a saturated hydrocarbon, and may have a straight chain, a branched chain or a cyclic structure. The aryl group is a substituent derived from an aromatic hydrocarbon and has a free valence on the aromatic ring. Even if it has only an aromatic ring such as a phenyl group, it does not have a valence such as a tolyl group. It may have an aromatic hydrocarbon structure as a partial structure. The aralkyl group means an alkyl group having an aryl group as a substituent.

Specific examples of the imidazole derivative represented by the above formula include 1-benzyl-2-methylimidazole and 1-benzyl-2-methylimidazole.
Benzyl-2-ethylimidazole, 1-benzyl-2
-Phenylimidazole, 1-benzyl-2-ethyl-
4-methylimidazole, 1-benzyl-2-ethyl-
5-methylimidazole, 1- (2-cyanoethyl)-
2-methylimidazole, 1- (2-cyanoethyl)-
2-ethylimidazole, 1- (2-cyanoethyl)-
2-isopropylimidazole, 1- (2-cyanoethyl) -2-undecylimidazole, 1- (2-cyanoethyl) -2-heptadecylimidazole, 1- (2-
Cyanoethyl) -2-phenylimidazole, 1- (2
-Cyanoethyl) -2-ethyl-4-methylimidazole, 1- (2-cyanoethyl) -2-ethyl-5-methylimidazole and the like can be mentioned.

As the imidazole derivative having a substituent at the 1-position, an adduct obtained by reacting an imidazole derivative having no substituent at the 1-position shown in the following formula 3 with an epoxy compound is also preferable.

[0036]

Embedded image

In the formula, R ₅ represents an alkyl group, an aryl group or an aralkyl group which is unsubstituted or has one or more substituents selected from halogen, a hydroxyl group and a cyano group,
R _{6 to} R ₇ are unsubstituted or represent an alkyl group, an aryl group, an aralkyl group or a hydrogen atom having one or more substituents selected from halogen, a hydroxyl group and a cyano group.

Specific examples of the imidazole derivative having no substituent at the 1-position used for the synthesis of the adduct include 2-methylimidazole, 2-ethylimidazole, 2-isopropylimidazole, 2-undecylimidazole, and 2
-Heptadecyl imidazole, 2-phenyl imidazole, 2-ethyl-4-methyl imidazole, 4,5-bishydroxymethyl-2-phenyl imidazole, 5-
Hydroxymethyl-4-methyl-2-phenylimidazole, 4-benzyl-5-hydroxymethyl-2-phenylimidazole, 4,5-bishydroxymethyl-2
-Phenylimidazole and the like can be mentioned.

The epoxy compound used for the synthesis of the adduct is a monoepoxy compound such as phenyl glycidyl ether or butyl glycidyl ether, or bisphenol A.
A diepoxy compound such as a type epoxy resin or a bisphenol F type epoxy resin is used.

The boric acid ester compound used in the epoxy resin composition of the present invention may be a compound represented by the following general formula, which is used as a surface treatment agent for the above amine compound. B (OR ₈ ) (OR ₉ ) (OR ₁₀ ) (In the formula, R _{8 to} R ₁₀ represent an alkyl group, an aralkyl group or an aryl group.)

Typical boric acid ester compounds include boric acid trimethyl ester, boric acid triethyl ester, boric acid tripropyl ester, boric acid triisopropyl ester, boric acid tributyl ester, boric acid triisobutyl ester, boric acid. Tri-tert-butyl ester, tripentyl borate, trihexyl borate, trioctyl borate, trihexadecyl borate, trioctadecyl borate, tricresyl borate, trihexadecyl borate, Examples thereof include boric acid tricyclohexyl ester, boric acid triphenyl ester, boric acid tritolyl ester, boric acid tribenzyl ester, boric acid dimethyl ester, boric acid diethyl ester, and boric acid monomethyl ester. These boric acid ester compounds have no problems with toxicity and metal corrosiveness.

These borate ester compounds may be used alone or in combination with a silane coupling agent, a titanate coupling agent, an aluminate coupling agent, a zircoaluminate coupling agent and the like.

Further, in order to control the addition reaction of the amine compound or prevent oxidation, an additive such as a phenol compound may be added. As the phenolic compound to be added, compounds such as pyrogallol and phenolic resin described in JP-A-6-172495, hindered phenolic antioxidants, tocopherol antioxidants and the like are used.

The epoxy resin composition of the present invention can be obtained by kneading particles containing an amine compound, which has been surface-treated with a borate ester compound, with an epoxy resin and other raw materials. As the method of surface treatment, a method of stirring in a mixer or a method of contacting in an airflow type pulverizer or an airflow type classifier as described in JP-A-6-73156 is used.

The epoxy resin composition of the present invention can also be obtained by individually adding the amine compound and the borate ester compound to the epoxy resin and other raw materials, and then kneading with stirring. In the case of the latter production method, since the borate ester compound has no reactivity with the epoxy resin, the surface of the amine compound-containing particles is treated with the borate ester compound in the epoxy resin. Further, it suggests that even if the surface treatment of the amine compound-containing particles is broken during kneading, the particles can be repaired.

A mixture of a boric acid ester compound, an epoxy resin and a phenol compound is commercially available from Shikoku Chemicals under the trade name "Cureduct" L-01B. Such a commercially available product may be used for the preparation of the epoxy resin composition of the present invention.

The epoxy resin composition for composite materials of the present invention contains other curing agents, thermoplastic resins, elastomers, thermoplastic elastomers, inorganic particles and the like in addition to the epoxy resin, amine compound and borate ester compound. be able to.

When other curing agent is blended, it is not particularly limited, but those which are accelerated or catalyzed by the above-mentioned amine compound are preferable.

The thermoplastic resin, the elastomer and the thermoplastic elastomer are used for the purpose of adjusting the viscosity of the epoxy resin composition, adjusting the tackiness of the prepreg, controlling the flow during the curing process, improving the toughness of the cured product, and improving the adhesion to the reinforcing fiber. Is added in.

The thermoplastic resin is not particularly limited, but a resin that is easily dissolved in an epoxy resin is preferably used. Further, even a thermoplastic resin insoluble in an epoxy resin can be preferably blended as long as it is made into fine particles. Specifically, acrylic resin, polyvinyl acetal, phenoxy resin, polyester, polycarbonate, polyarylene oxide, polysulfone, polyamide, and polyimide are preferably used.

The acrylic resin is a polymer of acrylic acid ester or methacrylic acid ester, and a typical one is polymethylmethacrylate. Commercially available products are "Delpet" (manufactured by Asahi Kasei Corporation), "Acrypet"
(Made by Mitsubishi Rayon Co., Ltd.). Polyvinyl acetal is a resin obtained by acetalizing polyvinyl alcohol with a carbonyl compound such as formaldehyde or acetaldehyde, and examples thereof include polyvinyl formal and polyvinyl acetal. "Denka Butyral" is a commercial product
And "Denka Formal" (Denki Kagaku Kogyo Co., Ltd.)
Manufactured by Chisso Co., Ltd. and the like.
Phenoxy resin is a resin obtained by condensing bisphenol A and epochlorohydrin.
R "PKHP (made by Union Carbide) and the like.
Polyester is a polymer having a carboxylic acid ester bond in the main chain. Examples of commercially available products include "Byron" (manufactured by Toyobo Co., Ltd.). Polycarbonate is a polymer having a carbonic acid ester bond in the main chain, and bisphenol A carbonate is typical. Commercially available products include "Panlite" (manufactured by Teijin Kasei Co., Ltd.). Polyarylene oxide is a resin having a main chain structure in which aromatic divalent groups and oxygen atoms are alternately arranged. Commercially available products include "Noryl" (manufactured by General Electric Co.). Polysulfone is a resin having a sulfonyl group in the main chain. In many cases, the main chain has an ether bond or the like. Commercially available products include "Victorex" (manufactured by Mitsui Toatsu Chemicals, Inc.) and "UDEL" (manufactured by Union Carbide Co.). Polyamide is a resin having a carboxylic acid amide structure in its main chain. Commercial products include "macromelt"
(Manufactured by Henkel Hakusui Co., Ltd.), "Amilan" CM4000
(Made by Toray Industries, Inc.) Polyimide is a resin having a dicarboxylic imide structure in the main chain. In addition, it may have an ether bond or an amide bond. Commercial products include "Ultem" (manufactured by General Electric), "Mat"
rimid ”5218 and the like.

Of these, polysulfones, polyarylene oxides, and polyimides are suitable for applications requiring heat resistance. Polyvinyl formal is excellent in the effect of controlling the resin flow and improving the tackiness of the prepreg. Polysulfone and polyvinyl formal have the effect of improving the adhesiveness to carbon fibers, and can improve the interlaminar shear strength, compressive strength, bending strength and the like.

As the elastomer, a copolymer of acrylonitrile and butadiene as raw materials is preferably used because of its excellent solubility in epoxy resin. In particular, use of an epoxy resin having a carboxyl group, an amino group, an epoxy group, or the like or a functional group capable of reacting with a curing agent thereof is particularly preferable because the toughness of the cured product is greatly improved.

Particles containing an epoxy resin-insoluble elastomer phase can also be preferably used. Although it is possible to use the crosslinked elastomer particles themselves,
Particularly, core-shell type elastomer particles obtained by coating the surface of epoxy resin-insoluble elastomer particles with a non-elastomer component can be particularly preferably used. In this case, the component to be coated may be one that dissolves or swells in the epoxy resin, such as polymethylmethacrylate, and is rather preferable because the particles are well dispersed in the epoxy resin. When particles containing an epoxy resin-insoluble elastomer phase are used, there is an advantage that the heat resistance of the cured resin is superior to that of a normal elastomer.

The addition of these elastomers has the effect of improving the toughness and the tackiness of the prepreg. In particular, when fine core-shell type elastomer particles having a particle size of about 0.1 to 0.3 μm are mixed, the effect of improving the toughness is remarkable.

As the thermoplastic elastomer, those which are easily dissolved in an epoxy resin are preferably used. Specifically, a block copolymer having a polyether structure as the soft segment and an aromatic polyester or aliphatic polyamide structure as the hard segment is preferable. Commercially available polyester thermoplastic elastomers include "Hytrel" manufactured by Toray-Dupont, "Perprene" manufactured by Toyobo Co., Ltd., "ARNITE" manufactured by Akzo, "LOMOND" manufactured by General Electric, and commercially available polyamides. Examples of the thermoplastic elastomers include "VESTAMID" manufactured by Huls, "PEBAX" manufactured by ATOCHEM, "Grelax A" manufactured by EMS, and "NOVAMID" manufactured by Mitsubishi Kasei. Addition of these thermoplastic elastomers has the effects of improving the toughness of the cured product and improving the tack when used as the matrix resin of the prepreg. Further, the heat resistance of the cured product is superior to the case where a normal elastomer is added.

Inorganic particles such as silica, alumina, titanium oxide, zirconia, clay minerals, talc, mica and ferrite can be further compounded in the epoxy resin composition for fiber reinforced composite material of the present invention. These additions include
It has the effect of increasing the viscosity of the resin composition and reducing the resin flow, the effect of improving the elastic modulus and heat resistance of the cured resin, and the effect of improving wear resistance. Further, particles of metal, carbon black, copper oxide, tin oxide and the like can be added to improve conductivity.

The fiber-reinforced composite material can be obtained by impregnating the reinforcing fiber with the epoxy resin for fiber-reinforced composite material of the present invention and heating. As the reinforcing fibers, glass fibers, carbon fibers, aramid fibers, boron fibers, alumina fibers, silicon carbide fibers and the like are used. Among these, carbon fibers having excellent strength and elastic modulus and having a small specific gravity are particularly preferable because a fiber-reinforced composite material having excellent specific strength and specific elastic modulus can be obtained.

As a method for directly obtaining a fiber-reinforced composite material from the epoxy resin for fiber-reinforced composite material and the reinforcing fiber, after applying the epoxy resin composition to a woven fabric or mat of the reinforcing fiber and impregnating it with a roller or the like under pressure. A heat-curing wet lay-up method, a reinforcing fiber bundle impregnated with an epoxy resin composition and wound around a mold called a mandrel, and a heat-curing filament winding method, a predetermined method while impregnating the reinforcing fiber into the epoxy resin composition. Of the epoxy resin composition to a sheet molding machine together with a reinforcing fiber cut into continuous or predetermined dimensions by supplying to a heating die having a shape of, a shape is obtained by continuously picking up and heat curing to obtain a product. Sheet molding compound method to obtain sheet material by supplying and pressure impregnating, reinforcing fiber The preform was shaped into a shape in advance product fabrics or mats placed in the mold, the epoxy resin composition can be used a method of resin transfer molding method or the like for curing is injected into the mold. Conventionally, in these methods, a two-pack type epoxy resin composition is often used, and since the pot life after mixing the two packs is short, there are many process restrictions. The epoxy resin composition of the present invention can be used in one liquid,
Since there is no practical limit to the pot life, the process has a large degree of freedom, which is advantageous.

Further, the reinforced fiber is impregnated with an uncured epoxy resin composition, and a sheet-, tape- or string-shaped prepreg intermediate can be used to obtain a fiber-reinforced composite material. Since the prepreg uses a one-pack type epoxy resin, the conventional prepreg has poor storage stability and requires freezing storage. Since the epoxy resin composition of the present invention has excellent storage stability, it can be stored in a refrigerator or at room temperature and is much easier to use than conventional products. The shape of the reinforcing fibers in the prepreg is not particularly limited, and examples thereof include long fibers aligned in one direction, tows, woven fabrics, mats, knits, and braids. For the production of prepreg, for example, an epoxy resin composition is applied onto a release paper using a reverse roll coater or the like to prepare a resin film, and the resin film is laminated from one side or both sides of the reinforcing fiber and heated and pressed. A method of impregnating the reinforcing fibers can be used.

[0061]

The present invention will be described in more detail with reference to the following examples. Example 1 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (produced by Yuka Shell Epoxy Co., Ltd.) 70 parts-Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 30 parts-Imidazole and bisphenol A type Epoxy resin adduct "Cure Duct" P-0505 (manufactured by Shikoku Chemicals Co., Ltd.) 20 parts (average particle size 2.1 µm, particles having a size of 10 µm or more 0%) ・ Tributyl borate ester (manufactured by Aldrich Chemical Co.) 0.5 copy

The above epoxy resin composition was applied onto a release paper using a film coater to prepare a resin film. The basis weight of the resin film was 37 g / m ² . Carbon fiber "Torayca" T700S (manufactured by Toray Industries, Inc., weight 150g)
/ M ² ) and heat and pressure impregnation from both sides to obtain a prepreg. When the glass transition temperature of this prepreg was measured by the DSC method (differential scanning calorimetry), it was -11 ° C. After leaving this prepreg at 40 ° C. for 30 days,
The glass transition temperature was measured and found to be 5 ° C. The glass transition temperature of the composite material obtained by laminating 8 sheets of the above prepreg and curing the same at 130 ° C. for 2 hours was 144 ° C. when measured by the DSC method.

Example 2 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (produced by Yuka Shell Epoxy Co., Ltd.) 70 parts-Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 30 parts-Imidazole and bisphenol A type Epoxy resin adduct "Cure duct" P-0505 (manufactured by Shikoku Chemicals Co., Ltd.) 20 parts ・ A mixture of tributyl borate, phenol resin and bisphenol A type epoxy resin "Cure duct" L-01B (Shikoku Kasei) 11 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -10 ° C. After leaving this prepreg at 40 ° C. for 30 days,
The glass transition temperature was measured and found to be 6 ° C. The glass transition temperature of the composite material obtained by laminating 8 of the above prepregs and curing them at 130 ° C. for 2 hours was 142 ° C. when measured by the DSC method.

Example 3 (1) Preparation of imidazole / epoxy adduct 30 parts of 2-methylimidazole and 90 parts of xylene were heated to 120 ° C. with stirring and dissolved. While continuing stirring, 87 parts of phenylglycidyl ether was added dropwise over 1 hour, and stirring was continued for another 30 minutes for reaction. Then, xylene was removed under reduced pressure and then dried at 70 ° C. for 24 hours to obtain a viscous liquid imidazole / epoxy adduct.

(2) Preparation of imidazole / epoxy adduct-containing particles 50 parts of this imidazole / epoxy adduct and 50 parts of polyetherimide "Ultem" 1000 (softening point 219 ° C, manufactured by General Electric Co.) were added to 40 parts of methylene chloride.
Polyvinyl alcohol (saponification degree 87 mol%, degree of polymerization 500) while dissolving in 0 parts and stirring at 8000 rpm
600 parts of an aqueous solution in which 5% by weight of was dissolved was gradually added to obtain an emulsion solution. Then, the mixture was gradually heated to 50 ° C. with stirring at 15 rpm, and methylene chloride was removed over 2 hours to obtain an aqueous dispersion of fine particles. Filter this dispersion,
The particles were washed and vacuum dried at room temperature for 24 hours to obtain imidazole / epoxy adduct-containing particles. When the particle size distribution was measured with a laser diffraction particle size distribution analyzer SALD-200A (manufactured by Shimadzu Corporation), the average particle size was 3 μm, and the particle size of 20 μm or less was 0%.

(3) Preparation of Epoxy Resin Composition The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 70 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Prepared with (2) Imidazole / epoxy adduct-containing particles 10 parts-Buric acid tributyl ester / phenolic resin / bisphenol A type epoxy resin mixture "Cureduct" L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 11 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -11 ° C. After leaving the prepreg at 40 ° C for 180 days,
The glass transition temperature was measured and found to be 9 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 sheets of the above prepreg and curing them under the condition of 130 ° C. for 2 hours was DS.
It was 143 degreeC when measured by the C method.

Example 4 (1) Preparation of particles containing imidazole 25 parts of 1-benzyl-2-phenylimidazole and 75 parts of polyetherimide "Ultem" 1000 were dissolved in 675 parts of methylene chloride and stirred at 3000 rpm while stirring. Alcohol sulfate ester soda (“Monogen”)
Y-100, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) was gradually added to 900 parts of an aqueous solution in which 1% by weight was dissolved to obtain an emulsion solution. Then, the mixture was gradually heated to 60 ° C. with stirring at 15 rpm, and methylene chloride was removed over 2 hours to obtain an aqueous dispersion of fine particles. The dispersion is filtered, washed and washed at room temperature for 2
It was vacuum dried for 4 hours to obtain imidazole-containing particles. The average particle size was 4 μm, and the particle size of 10 μm or more was 0%.

(2) Preparation of Epoxy Resin Composition The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 35 parts-Imidazole-containing particles prepared in (1) 10 parts-A mixture of tributyl borate, a phenol resin and a bisphenol A type epoxy resin "Cureduct" L- 01B (manufactured by Shikoku Chemicals Co., Ltd.) 11 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. The glass transition temperature of this prepreg was 2 ° C. when measured by the DSC method.
After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be 5 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 of the above prepregs and curing them at 130 ° C. for 2 hours was measured by DSC.
It was 146 degreeC when measured by the method.

Example 5 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Addition of imidazole and bisphenol A type epoxy resin "Cureduct" P-0505 (produced by Shikoku Chemicals Co., Ltd.) 5 parts ・ Tributyl borate ester , A mixture of phenol resin and bisphenol A type epoxy resin "Cureduct" L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 2.5 parts ・ Dicyandiamide 4 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was 0 ° C.
After the prepreg was left at 40 ° C. for 30 days, the glass transition temperature was measured and found to be 1 ° C. The glass transition temperature of the composite material panel obtained by laminating eight of the above prepregs and curing them at 130 ° C. for 2 hours was 151 ° C. when measured by the DSC method.

Example 6 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 35 parts-Imidazole-containing particles prepared in Example 4 (1) 4 parts-Borate tributyl ester, phenol resin and bisphenol A type epoxy resin mixture "Cureduct" "L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 2.5 parts-Dicyandiamide 4 parts

The flexural modulus of the resin plate obtained by heating the epoxy resin at 130 ° C. for 2 hours to cure was measured. The flexural modulus was 3230 MPa. A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -1 ° C. 180 at 40 ℃ this prepreg
When the glass transition temperature was measured after leaving it for one day, it was 0.
° C. Laminate 8 sheets of the above prepreg,
The glass transition temperature of the composite material panel obtained by curing under the condition of 2 hours was 141 ° C. when measured by DSC method. When the interlaminar shear strength of this panel was measured,
It was 64 MPa.

Example 7 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (produced by Yuka Shell Epoxy Co., Ltd.) 70 parts-Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 30 parts-Imidazole and bisphenol A type 20 parts of particles obtained by surface-treating an adduct of epoxy resin with boric acid ester and phenol resin

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -8 ° C. After leaving this prepreg at 40 ° C. for 30 days,
The glass transition temperature was measured and found to be 7 ° C. The glass transition temperature of the composite material obtained by laminating 8 sheets of the above prepreg and curing the same at 130 ° C. for 2 hours was 140 ° C. when measured by the DSC method.

Comparative Example 1 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (produced by Yuka Shell Epoxy Co., Ltd.) 70 parts-Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 30 parts-Imidazole and bisphenol A type Epoxy resin adduct "Cure duct" P-0505 (manufactured by Shikoku Chemicals Co., Ltd.) 20 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -8 ° C. After the prepreg was left at 40 ° C. for 5 days, the glass transition temperature was measured and found to be 42 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 sheets of the above prepreg and curing them under the condition of 130 ° C. for 2 hours was DS.
It was 144 degreeC when measured by the C method.

Comparative Example 2 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 70 parts-Phenol novolac type epoxy resin "Epicoat" 154 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts-Example 3 (2) ) Particles containing imidazole / epoxy adduct prepared in 10)

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -9 ° C. After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be 2 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 of the above prepregs and curing the same at 130 ° C. for 2 hours was 150 ° C. when measured by the DSC method.

Comparative Example 3 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 35 parts. 10 parts of imidazole-containing particles prepared in Example 4 (1).

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. The glass transition temperature of this prepreg was 1 ° C. when measured by the DSC method.
After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be 13 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 sheets of the above prepreg and curing them under the condition of 130 ° C. for 2 hours was DS.
It was 146 degreeC when measured by the C method.

Comparative Example 4 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Addition of imidazole and bisphenol A type epoxy resin "Cure duct" P-0505 (produced by Shikoku Chemicals Co., Ltd.) 5 parts ・ Dicyandiamide 4 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. The glass transition temperature of this prepreg was 1 ° C. when measured by the DSC method.
After leaving this prepreg at 40 ° C. for 5 days, the glass transition temperature was measured and found to be 20 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 of the above prepregs and curing at 130 ° C. for 2 hours was 152 ° C. when measured by DSC method.

Comparative Example 5 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts-Imidazole-containing particles prepared in Example 4 (1) 4 parts-Dicyandiamide 4 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was 0 ° C.
After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be 12 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 sheets of the above prepreg and curing them under the condition of 130 ° C. for 2 hours was DS.
It was 144 degreeC when measured by the C method.

Example 8 The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A-type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 40 parts-Bisphenol A-type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 60 parts-Example 4 (1) 4 parts of imidazole-containing particles prepared in), a mixture of boric acid tributyl ester, phenol resin and bisphenol A type epoxy resin "Cureduct" L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 2.5 parts dicyandiamide 4 parts

The toughness of the resin plate obtained by heating the epoxy resin at 130 ° C. for 2 hours and curing was measured by the SENB method. The resin toughness was 230 J / cm ² . A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -5 ° C. This prepreg is 4
The glass transition temperature after standing for 180 days at 0 ° C. was −3 ° C.

Example 9 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 33 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 60 parts ・ Terminal carboxyl group-modified acrylonitrile -Butadiene rubber "Hycar" CTBN 1300X13 (manufactured by Ube Industries, Ltd.) 50 parts and pre-reacted product of 50 parts of "Epicoat" 828 14 parts-Imidazole-containing particles prepared in Example 4 (1) -4 parts-Tributyl borate Mixture of ester, phenolic resin and bisphenol A type epoxy resin "Cureduct" L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 2.5 parts ・ Dicyandiamide 4 parts

The toughness of the resin plate obtained by heating the epoxy resin at 130 ° C. for 2 hours to cure was measured by the SENB method. The resin toughness was 1100 J / cm ² . A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -7 ° C. After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be −5 ° C.

Example 10 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 40 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 60 parts ・ Core shell rubber particles "Paraloid" "EXL2655 7 parts-Imidazole-containing particles prepared in Example 4 (1) 4 parts-A mixture of tributyl borate, a phenol resin, and a bisphenol A type epoxy resin" Cure Duct "L-01B (manufactured by Shikoku Chemicals Co., Ltd.) ) 2.5 parts ・ Dicyandiamide 4 parts

The toughness of the resin plate obtained by heating the epoxy resin at 130 ° C. for 2 hours and curing was measured by the SENB method. The resin toughness was 1190 J / cm ² . A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -4 ° C. After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be −3 ° C.

Example 11 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A-type epoxy resin "Epicoat" 828 (produced by Yuka Shell Epoxy Co., Ltd.) 40 parts-Bisphenol A-type epoxy resin "Epicoat" 1001 (produced by Yuka Shell Epoxy Co., Ltd.) 60 parts-Polyamide thermoplastic elastomer "PEBAX" 4033 7 parts-Imidazole-containing particles prepared in Example 4 (1) 4 parts-A mixture of tributyl borate, a phenol resin and a bisphenol A type epoxy resin "Cure Duct" L-01B (Shikoku Chemicals Co., Ltd. )) 2.5 parts dicyandiamide 4 parts

The toughness of the resin plate obtained by heating the epoxy resin at 130 ° C. for 2 hours and curing was measured by the SENB method. The resin toughness was 950 J / cm ² . A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was -3 ° C. This prepreg is 4
The glass transition temperature after standing for 180 days at 0 ° C. was 0 ° C.

Example 12 (1) Preparation of epoxy resin composition The following materials were mixed to obtain an epoxy resin composition. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts-Polyvinyl formal "Vinirec" K 7 parts-Imidazole-containing particles prepared in Example 4 (1) 10 parts-Boric acid tributyl ester, phenol resin and bisphenol Mixture of A type epoxy resin "Cure duct" L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 11 parts

A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. The glass transition temperature of this prepreg was 2 ° C. when measured by the DSC method.
After the prepreg was left at 40 ° C. for 180 days, the glass transition temperature was measured and found to be 4 ° C. The glass transition temperature of the composite material panel obtained by laminating 8 of the above prepregs and curing them at 130 ° C. for 2 hours was measured by DSC.
It was 144 degreeC when measured by the method. The interlayer shear strength of this panel was measured and found to be 77 MPa.

Example 13 An epoxy resin composition was obtained by mixing the following materials. -Bisphenol A type epoxy resin "Epicoat" 828 (manufactured by Yuka Shell Epoxy Co., Ltd.) 30 parts ・ Bisphenol A type epoxy resin "Epicoat" 1001 (manufactured by Yuka Shell Epoxy Co., Ltd.) 35 parts ・ Phenol novolac type epoxy resin "Epicoat" 154 (produced by Yuka Shell Epoxy Co., Ltd.) 35 parts-Silica fine particles "Aerosil" 380 10 parts-Imidazole-containing particles prepared in Example 4 (1) 4 parts-Boric acid tributyl ester, phenol resin and bisphenol Mixture of A type epoxy resin "Cure duct" L-01B (manufactured by Shikoku Chemicals Co., Ltd.) 2.5 parts ・ Dicyandiamide 4 parts

The flexural modulus of the resin plate obtained by heating the epoxy resin at 130 ° C. for 2 hours to cure was measured. The flexural modulus was 3430 MPa. A prepreg was obtained from the above epoxy resin composition in the same manner as in Example 1. When the glass transition temperature of this prepreg was measured by the DSC method, it was 0 ° C. After the prepreg was left at 40 ° C for 180 days, the glass transition temperature was measured to be 2 ° C.
Met. Eight of the above prepregs were laminated and heated at 130 ° C for 2
The glass transition temperature of the composite material panel obtained by curing under the condition of time was 144 ° C. when measured by the DSC method.

[0100]

INDUSTRIAL APPLICABILITY The epoxy resin composition and prepreg for a fiber-reinforced composite material of the present invention have excellent storage stability as compared with conventional epoxy resin compositions and prepregs, and have a longer storage time than conventional products or conventional products. It can be stored at a higher temperature, which is advantageous in terms of handleability and economy. Further, it has a suitable curability and a curing speed, and a cured product excellent in physical properties such as heat resistance can be obtained.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 7/02 C08K 7/02 C08L 9/02 LBP C08L 9/02 LBP 29/14 LGU 29/14 LGU 67 / 00 LPC 67/00 LPC 69/00 LPQ 69/00 LPQ 71/10 LQK 71/10 LQK 77/00 LQT 77/00 LQT 79/08 LRC 79/08 LRC 81/06 LRF 81/06 LRF

Claims (20)

[Claims] 1. An epoxy resin composition for a fiber reinforced composite material, which comprises the following components. A: Epoxy resin B: Particles containing an amine compound having an average particle size of 10 μm or less C: Borate ester compound 2. The epoxy resin for a fiber-reinforced composite material according to claim 1, wherein particles having a particle size of 20 μm or more account for 10% or less in a particle size distribution of particles containing an amine compound. 3. The epoxy resin for a fiber-reinforced composite material according to claim 1, wherein the content of the amine compound in the particles containing the amine compound is 5% by weight or more. 4. The content of the amine compound in the particles containing the amine compound is 20 to 80% by weight.
Epoxy resin for fiber reinforced composite materials. 5. The epoxy resin composition for a fiber reinforced composite material according to claim 1, wherein the particles containing an amine compound are pretreated with boric acid ester. 6. The epoxy resin composition for a fiber-reinforced composite material according to claim 1, wherein the particles containing an amine compound are composed of an amine compound and a thermoplastic resin. 7. The epoxy resin composition for a fiber-reinforced composite material according to claim 1, wherein the amine compound is an imidazole derivative. 8. The epoxy resin composition for a fiber reinforced composite material according to claim 7, wherein the imidazole derivative is a compound represented by the following formula 1. Embedded image R _{1 to} R ₂ represent an alkyl group, an aryl group or an aralkyl group which is unsubstituted or has one or more substituents selected from halogen, a hydroxyl group and a cyano group, and R _{3 to} R 2
₄ represents an alkyl group, an aryl group, an aralkyl group or a hydrogen atom which is unsubstituted or has one or more substituents selected from halogen, a hydroxyl group and a cyano group. 9. The epoxy resin composition for a fiber-reinforced composite material according to claim 7, wherein the imidazole derivative is an adduct of an imidazole derivative having no substituent at the 1-position and an epoxy compound. 10. The epoxy resin composition for a fiber-reinforced composite material according to claim 1, which contains a curing agent which is accelerated or catalyzed by an amine compound. 11. A curing agent which is accelerated or catalyzed by an amine compound is dicyandiamide, an acid anhydride type curing agent, a hydrazide type curing agent, a phenol type curing agent,
The epoxy resin composition for a fiber-reinforced composite material according to claim 10, which is a curing agent selected from mercaptan curing agents. 12. A thermoplastic resin, an elastomer, or a thermoplastic elastomer, which comprises a thermoplastic resin, an elastomer or a thermoplastic elastomer.
An epoxy resin composition for fiber-reinforced composite material according to any one of 1. 13. An acrylic resin as the thermoplastic resin,
The epoxy resin composition for a fiber reinforced composite material according to claim 12, which contains a resin selected from polyvinyl acetal, phenoxy resin, polyester, polycarbonate, polysulfone, polyarylene oxide, polyamide, and polyimide. 14. The epoxy resin composition for a fiber reinforced composite material according to claim 12, which contains an acrylonitrile-butadiene copolymer as an elastomer. 15. The epoxy resin for a fiber reinforced composite material according to claim 14, which contains an acrylonitrile-butadiene copolymer having a functional group capable of reacting with an epoxy resin or a curing agent thereof as an elastomer. 16. The epoxy resin composition for a fiber reinforced composite material according to claim 1, which contains particles containing an epoxy resin-insoluble elastomer phase. 17. The epoxy resin composition for a fiber reinforced composite material according to claim 12, which contains a polyester or polyamide thermoplastic elastomer. 18. The method according to claim 1, further comprising inorganic particles.
7. The epoxy resin composition for fiber reinforced composite material according to any one of 7. 19. A prepreg comprising the epoxy resin composition according to claim 1 and a reinforcing fiber. 20. A fiber-reinforced composite material comprising a reinforcing fiber and a matrix resin, wherein the matrix resin is a cured product of the epoxy resin composition according to any one of claims 1 to 18.