JP2002145986A - Epoxy resin composition and prepreg using the epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition which can give a demoldable primary cured product in a short time at a temperature of <=90 deg.C and can be secondarily cured at a high temperature to give the curd molded article having excellent heat resistance and excellent mechanical physical properties at high temperature, and to provide a prepreg using the epoxy resin composition. SOLUTION: This epoxy resin composition is characterized by comprising the following components (A), (B), and (C), or the components and further the components (D), and the prepreg prepared by impregnating a reinforcing material with the epoxy resin composition. (A) An epoxy resin containing a multi-functional epoxy resin having three or more epoxy resins in the molecule. (B) A latent curing agent which can cure the epoxy resin at <=100 deg.C and has a stability coefficient of <=2. (C) An acid anhydride- or phenol-based curing agent. (D) A during accelerator comprising a urea compound.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an epoxy resin composition and a prepreg using the epoxy resin composition.

[0002]

2. Description of the Related Art Fiber reinforced composite materials (hereinafter referred to as FRP)
Is widely used from sports and leisure to aircraft. The prepreg used as an intermediate base material during the molding of the FRP is obtained by impregnating a reinforcing material composed of a fiber aggregate with a matrix mainly composed of a thermosetting resin. The molding of FRP by prepreg
This is performed by laminating a prepreg, heating and pressurizing the prepreg, and curing a thermosetting resin forming a matrix.

There are two types of prepregs: low-temperature curing type, which cures at 60 to 100 ° C., according to curing temperature;
It is classified into three types: a medium-temperature curing type that cures at around 0 ° C., and a high-temperature curing type that cures at 170 ° C. or higher.

[0004] Of these, prepregs of the medium temperature curing type are general-purpose products mainly used for sports and leisure related applications which do not require high heat resistance.
Curing molding can be performed at about 20 ° C. for about 1 hour. Although the molded FRP has excellent mechanical properties, it does not have high heat resistance.

[0005] Low-temperature curing type prepregs can be cured at 90 ° C or lower, and the range of choice of integrally formed auxiliary materials is considerably wide. In addition, since a resin mold can be used for curing molding of a low-temperature curing type prepreg, equipment investment is reduced, which is very advantageous when a large number of molded products are produced in small quantities. It is also suitable for molding large molded products using a wooden mold. For example, to mold a hull, a method is used in which a prepreg is attached to a wooden mold, bagged, and then the temperature of the working room itself is raised to a curing temperature, followed by molding. The use of prepreg is very suitable. However, FRP molded by a low-temperature curing type prepreg has a poor heat resistance because it is cured at 90 ° C. or lower.

[0006] A high-temperature curing type prepreg is cured and molded at a curing temperature of about 180 ° C, and is used for molded articles in fields requiring heat resistance, such as aircraft applications. Although the molded FRP has very excellent heat resistance, it cannot use a resin mold because of the high molding temperature. It is impossible to mold the prepreg of the high temperature curing type at 90 ° C. or lower, or even if possible, it requires a very long time for curing molding, and the heat resistance of the obtained molded article is low. It drops significantly.

However, in recent years, there has been an increasing demand for prepregs that can be cured and molded at a relatively low temperature in a short time and that are cured and molded into molded products having excellent heat resistance. That is, it is desired to suppress the initial investment in the molding of the FRP and obtain a molded article having high heat resistance by performing curing molding using a resin mold. In addition, large-sized molded products, and molded products for applications that require heat resistance, such as aircraft fuselage,
This means that it is more convenient to mold.

[0008] In the case of a prepreg having a thermosetting resin as a matrix, the heat resistance of a molded product obtained by curing and molding the prepreg is related to the temperature at the time of curing and molding. For this reason, in response to the above requirements, first perform primary curing to cure the prepreg at a low temperature enough to remove the mold, then remove the mold, and then perform secondary curing at a high temperature. Thus, a method for obtaining a molded article having excellent heat resistance is adopted. In other words, by adopting a curing molding method that performs primary curing at low temperature and secondary curing at high temperature,
A resin mold that is a characteristic of low-temperature curing can be used, and a cured product having excellent heat resistance that is a characteristic of high-temperature curing can be obtained.

More specifically, a prepreg of a high-temperature curing type, which can obtain a molded article having high heat resistance by curing and molding at a high temperature, is first cured at a low temperature of 90 ° C. or lower to such an extent that it can be released from the mold. After the curing, the mold is released, and then the secondary curing is performed by post-curing at a high temperature of 180 ° C. or higher, so that a resin mold can be used, and the cured product having high heat resistance can be used. Can be formed.

However, as described above, a high-temperature curing type prepreg usually does not cure at a curing temperature of 90 ° C. or lower, or even if it cures, it requires a considerably long time for curing.

Some of the prepregs currently on the market are subjected to primary curing at a temperature of 100 ° C. or less for about 5 hours and then secondary curing at 177 ° C.
Some prepregs can be made into high heat-resistant molded products, but such prepregs have very poor stability near room temperature, have only a few days of working life, or have considerable tackiness, so workability is extremely low. It is currently bad.

For example, JP-A-2-151623 discloses an epoxy resin composition using dicyandiamide, a urea compound and diaminodiphenylsulfone as curing agents. According to the prepreg using this epoxy resin composition, it is presumed that a molded article having excellent heat resistance can be obtained by curing at a high temperature.
It is impossible to cure and mold at a low temperature of 0 ° C. or lower.

As prepregs which can be cured at low temperatures, for example, Japanese Patent Application Laid-Open No. H11-302412 discloses
It is described that it can be cured in about 0 ° C. × 2 hours, and that the physical properties of the obtained cured product are very good, but the low-temperature cured product of the prepreg described here is subjected to secondary curing. However, high heat resistance cannot be expected from the molded product.

Further, Japanese Patent Publication No. 7-121989 discloses that
A prepreg for two-stage curing molding, in which precuring is performed at 75 to 100 ° C. for 0.5 to 2 hours, followed by after-curing at 180 to 200 ° C. for 0.5 to 1 hour, is shown. The prepreg has poor stability at room temperature, and is not particularly suitable for forming a large molded product that requires a long time in the laminating step.

[0015]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a long working life and a good handleability, and to perform a primary curing at which the mold can be removed from the mold at a relatively low temperature of 90 ° C. or less. Epoxy resin that can be cured in a short time at the curing temperature of the above, and then becomes a cured molded product with excellent heat resistance and excellent mechanical properties at a high temperature by performing secondary curing at a high temperature thereafter An object of the present invention is to provide a composition and a prepreg using the epoxy resin composition.

[0016]

The above object can be attained by the epoxy resin composition of the present invention having the constitution described below and a prepreg using the epoxy resin composition. That is, the epoxy resin composition of the present invention comprises an epoxy resin composition containing the following components (A), (B) and (C). (A) an epoxy resin containing a polyfunctional epoxy resin having three or more epoxy groups in a molecule; (B) a latent curing agent curable at 100 ° C. or less and having a stability coefficient of 2 or less (C ) Acid anhydride or phenolic curing agent

The epoxy resin composition of the present invention comprises an epoxy resin composition containing the following components (A), (B), (C) and (D).

(A) Epoxy resin containing a polyfunctional epoxy resin having three or more epoxy groups in the molecule. (B) Latent curing that can be cured at 100 ° C. or less and has a stability coefficient of 2 or less. (C) Acid anhydride or phenolic curing agent (D) Curing accelerator comprising urea compound

In the epoxy resin composition of the present invention having the above structure, the polyfunctional epoxy resin having three or more epoxy groups in the molecule in the component (A) is a diaminoglycidyl type epoxy resin. Preferably, the epoxy resin contains.

The polyfunctional epoxy resin having three or more epoxy groups in the molecule in the component (A) is an epoxy resin containing a polyfunctional epoxy resin represented by the following formula [7]. Preferably, there is.

[0021]

Embedded image [Wherein, n represents an integer of 0 or more]

Further, the content of the polyfunctional epoxy resin having three or more epoxy groups in the molecule in the component (A) is preferably 50% by mass or more of all epoxy resins, and 70% by mass of all epoxy resins. % Is more preferable.

The epoxy resin other than the polyfunctional epoxy resin having three or more epoxy groups in the molecule in the component (A) is a bisphenol A type epoxy resin and / or a compound represented by the following formula [Formula 8]. Epoxy resin containing an epoxy resin having an oxazolidone ring.

[0024]

Embedded image [Wherein, R represents a hydrogen atom or an alkyl group]

Further, the epoxy resin having an oxazolidone ring is preferably an epoxy resin having a structure represented by the following formula [Formula 9].

[0026]

Embedded image In the formula, R each independently represent a hydrogen atom or an alkyl group, R ₁ to R ₈ each independently represents a halogen atom, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, R ₉ is the following formula [Representing a bifunctional group of the formula [Formula 11] or the formula [Formula 11]]

[0027]

Embedded image [Wherein R ′ _{1 to} R ′ ₄ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms]

[0028]

Embedded image [Wherein R ′ _{1 to} R ′ ₈ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ′ ₉ represents —CH ₂ —, —C
_{(CH 3) 2 -, -} SO 2 -, - SO -, - S- or -
O-]

The curing agent constituting the component (B) is preferably a curing agent curable at 90 ° C. or lower. Further, the curing agent constituting the component (B) is preferably a latent curing agent having a stability coefficient of 1.5 or less.

The curing agent constituting the component (B) is preferably a microcapsule type curing agent, and more preferably an amine adduct type curing agent.

Further, component (B) is preferably blended in a proportion of 3 parts by mass or more, more preferably 5 parts by mass or more, with respect to 100 parts by mass of component (A). .

The component (B) is preferably blended in a proportion of 20 parts by mass or less, more preferably 10 parts by mass or less, with respect to 100 parts by mass of the component (A). .

Further, it is preferable that the component (C) is blended in a ratio of 0.4 equivalent or more with respect to the component (A), and it is more preferable that the component (C) is blended in a ratio of 0.6 equivalent or more. preferable.

The component (C) is added to the component (A) in an amount of 1.
It is preferred to be blended at a ratio of 5 equivalents or less,
More preferably, it is blended in a ratio of 1.3 equivalents or less.

The curing accelerator constituting the component (D) preferably comprises a urea compound containing a compound represented by the following formula [Chemical Formula 12].

[0036]

Embedded image

Further, the epoxy resin composition of the present invention comprises:
The viscosity at 0 ° C. is preferably 5 Pa · sec or more, more preferably 10 Pa · sec or more.

Further, the epoxy resin composition of the present invention contains 60
The viscosity at ° C is preferably 5,000 Pa · sec or less, more preferably 1,000 Pa · sec or less.

Further, the epoxy resin composition of the present invention comprises:
It is preferable that the rate of thickening at 60 ° C. when left at 25 ° C. for 3 weeks is within twice.

Further, the epoxy resin composition of the present invention has a flexural modulus of 1 when cured at 90 ° C. for 2 hours.
It is preferably at least 00 MPa, more preferably at least 300 MPa.

The epoxy resin composition of the present invention is cured at 90 ° C. for 2 hours and then cured at 200 ° C. for 4 hours to have a glass transition temperature of 150 ° C. or higher. The glass transition temperature is more preferably 170 ° C. or higher.

Further, the epoxy resin composition of the present invention is cured at 90 ° C. for 2 hours, and then cured at 200 ° C. for 4 hours. Is preferably 50 or more (elastic modulus at 180 ° C. × elastic modulus at 100/30 ° C.).

The prepreg of the present invention is obtained by impregnating a reinforcing material with the epoxy resin composition of the present invention having the above structure.

[0044]

BEST MODE FOR CARRYING OUT THE INVENTION In the epoxy resin composition of the present invention and a prepreg using the epoxy resin composition,
Examples of the polyfunctional epoxy resin having three or more epoxy groups in the molecule used for the component (A) in the epoxy resin composition include novolak type, aminophenol type, aminoglycidyl type and the like. The use of a diaminoglycidyl-type epoxy resin as a polyfunctional epoxy resin having three or more epoxy groups in a molecule leads to an improvement in physical properties of a cured product obtained by secondary curing. For example, tetraglycidyldiaminodiphenylmethane is used. be able to.
Further, a polyfunctional epoxy resin represented by the following formula [Formula 13] is also suitable.

[0045]

Embedded image [Wherein, n represents an integer of 0 or more]

When the epoxy resin constituting the component (A) contains a polyfunctional epoxy resin having three or more epoxy groups in the molecule in an amount of 50% by mass or more of the total epoxy resin,
The physical properties of the cured product obtained by the secondary curing are excellent, and when the content is 70% by mass or more, the physical properties of the cured product obtained by the secondary curing are further excellent.

There is no particular limitation on the other epoxy resin in the epoxy resin constituting the component (A), but a bisphenol A type epoxy resin is preferred in terms of handleability and cost. Further, as other epoxy resins in the epoxy resin constituting the component (A), the following formula [Formula 1]
When an epoxy resin having an oxazolidone ring represented by the formula [4] is used, the physical properties of a cured product obtained are excellent.

[0048]

Embedded image [Wherein, R represents a hydrogen atom or an alkyl group]

When the epoxy resin having an oxazolidone ring is an epoxy resin having a structure represented by the following formula [Formula 15], a prepreg using the epoxy resin composition of the present invention is cured and molded to form FRP. In this case, the adhesion between the reinforcing material and the matrix becomes more excellent, and the mechanical properties of the FRP are further improved.

[0050]

Embedded image In the formula, R each independently represent a hydrogen atom or an alkyl group, R ₁ to R ₈ each independently represents a halogen atom, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, R ₉ is the following formula [Representing a bifunctional group of the formula [Formula 16] or [Formula 17]]

[0051]

Embedded image [Wherein, R ′ _{1 to} R ′ ₄ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms]

[0052]

Embedded image [Wherein, R ′ _{1 to} R ′ ₈ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ′ ₉ represents —CH ₂ —,
_{C (CH 3) 2 -,} - SO 2 -, - SO -, - representing the S- or -O-]

As an epoxy resin having an oxazolidone ring represented by the following chemical formula 15, an epoxy resin manufactured by Asahi Kasei Epoxy Co., Ltd.
Examples include ER4151 and AER4152.

The curing agent constituting the component (B) in the epoxy resin composition of the present invention, that is, a latent curing agent which can be cured at 100 ° C. or less and has a stability coefficient of 2 or less, must first be cured at 100 ° C. or less. It must have the requirement of being curable.

Whether the curing agent can be cured at 100 ° C. or lower is determined as follows. That is, an epoxy resin composition obtained by uniformly mixing 20 parts by mass of a curing agent with 100 parts by mass of a liquid bisphenol A type epoxy resin having an epoxy equivalent of 184 to 194 (for example, Epicoat 828 manufactured by Yuka Shell Co.) The exothermic curing is measured at a heating rate of ° C / min. At this time, the temperature on the DSC chart, which is apart from the baseline and at which curing heat generation starts, is 10
When the temperature is 0 ° C or lower, the curing agent can be cured at 100 ° C or lower. In the case of a curing agent whose temperature at which the epoxy resin composition starts to generate curing heat is 90 ° C. or less, that is, when a curing agent curable at 90 ° C. or less is used,
It is preferable because the reactivity of the epoxy resin composition at a low temperature of 90 ° C. or lower is good.

Next, the curing agent constituting the component (B) must be a latent curing agent having a stability coefficient of 2 or less, and must exhibit heat latent reactivity. That is, the curing agent constituting the component (B) must be curable at a temperature of 100 ° C. or lower and have a stability coefficient of 2 or less that hardly reacts at around room temperature.

The stability coefficient of a curing agent curable at 90 ° C. or lower is measured by the following method. That is, a liquid bisphenol A type epoxy resin having an epoxy equivalent of 184 to 194 (for example, Epicoat 828 manufactured by Yuka Shell Co., Ltd.) 10
An epoxy resin composition obtained by uniformly mixing 20 parts by mass of a curing agent with 0 parts by mass is allowed to stand at 30 ° C. for 3 weeks, and the degree of thickening as compared to the viscosity before standing is defined as a stability coefficient. That is,
When the degree of thickening of the epoxy resin composition is twice, the stability coefficient is 2. Here, a curing agent having a stability factor of 2 or less hardly reacts at around room temperature, but a stability factor of 1.
A curing agent of 5 or less has more excellent latent reactivity,
It is suitable.

The viscosity of the epoxy resin composition for determining the stability coefficient of the curing agent is measured as follows. That is, DSR-200 manufactured by Rheometrics
Or a share speed of 1
Under the condition of 0 radians / sec, using two disc plates having a diameter of 25 mm, a disc plate interval of 0.5
The isothermal viscosity at 30 ° C. was measured in
Capture data after minutes. The viscosity of the epoxy resin composition for measurement is measured by this method before and after standing at 30 ° C. for 3 weeks, and the numerical value of “viscosity after standing / viscosity before standing” is defined as a stability coefficient.

The curing agent constituting the component (B) comprises 1
It suffices that the composition can be cured at a temperature of 00 ° C. or less and has a latent heat reactivity of a stability coefficient of 2 or less, and there is no particular limitation. The epoxy resin composition of the invention has 90
It is excellent in balance between curability at a temperature of not more than ℃ and stability at around room temperature. Curable at 100 ° C. or lower,
And has a heating latent reactivity having a stability coefficient of 2 or less,
In addition, as a hardening agent forming a microcapsule type, for example, NOVACURE HX3721 or HX manufactured by Asahi Kasei Epoxy
3722 and the like.

Further, an epoxy resin composition using an amine adduct-type curing agent as the curing agent constituting the component (B) has an even better balance between curability at 90 ° C. or lower and stability at around room temperature. It becomes something. As an amine adduct-type curing agent, Fuji Cure FXE100 manufactured by Fuji Kasei Co., Ltd.
0 and FXE1030, PN-23 manufactured by Ajinomoto Co., Inc.
ACR Hardener H-3615, H manufactured by CRL
-4070, H-3293, H-3366, H-384
9, H-3670, cure duct P manufactured by Shikoku Chemicals
-0505 and the like.

The epoxy resin composition of the present invention cures in a relatively short time in a primary curing step at a relatively low temperature to such an extent that it can be released from the mold by the action of the curing agent constituting component (B).
In the subsequent secondary curing process at a high temperature, a high heat resistant cured product having a completed crosslinked structure is obtained by the action of the acid anhydride-based or phenol-based curing agent constituting the component (C).

The amount of the curing agent constituting the component (B) is not particularly limited. However, if the amount is too small, it becomes difficult to cure the composition by primary curing to such an extent that the mold can be removed. Therefore, when the amount of the epoxy resin constituting the component (A) is 100 parts by mass, the amount of the curing agent constituting the component (B) is preferably 3 parts by mass or more, and the addition of 5 parts by mass or more makes it possible to reduce the primary temperature at a low temperature. Curability is further improved. However,
If the added amount of the curing agent constituting the component (B) is excessive, the mechanical properties of the obtained cured product, particularly the elastic modulus at high temperatures, decrease. For this reason, the preferable upper limit of the addition amount is 20 parts by mass or less when the mass of the epoxy resin constituting the component (A) is 100, and when it is 10 parts by mass or less, the obtained cured product at a high temperature can be obtained. Physical properties become better. In addition,
The addition amount of the curing agent constituting the component (B) is, as in a commercially available product,
When the curing agent is in the form of a paste with a low-viscosity epoxy resin or the like, it is of course the mass of only the active ingredient.

Among the acid anhydride-based or phenol-based curing agents constituting the component (C), examples of the acid anhydride-based curing agent include phthalic anhydride or a derivative thereof, methylnadic anhydride, dodecylsuccinic anhydride, and anhydride. Chlorendic acid, pyromellitic anhydride, benzophenonetetracarboxylic anhydride, ethylene glycol bis (anhydrotrimate), methylcyclohexenetetracarboxylic anhydride,
And trimellitic anhydride. In addition, examples of the phenol-based curing agent include novolac-type curing agents such as phenol novolak and cresol novolak.

The amount of the acid anhydride-based or phenol-based curing agent constituting the component (C) is not particularly limited, but if it is 0.4 equivalent or more of the epoxy resin constituting the component (A), The heat resistance of the cured product obtained after the secondary curing is improved, and when it is 0.6 equivalent or more, the heat resistance is further improved. However, if the addition amount of the acid anhydride-based or phenol-based curing agent constituting the component (C) is excessive, the heat resistance of the cured product obtained after the secondary curing decreases, so that the epoxy resin constituting the component (A) It is preferably not more than 1.5 equivalents, more preferably not more than 1.3 equivalents. Here, the equivalent of the curing agent indicates an acid anhydride equivalent for an acid anhydride-based curing agent, and an active hydrogen equivalent for a phenol-based curing agent.

The epoxy resin composition of the present invention to which a curing accelerator comprising a urea compound constituting the component (D) is added,
Curability at a relatively low temperature, particularly at 90 ° C. or lower, is improved without impairing the stability at room temperature.

The curing accelerator composed of a urea compound constituting the component (D) is not particularly limited as long as it is a urea compound.
Dimethylurea is preferable because it can achieve a good balance with the curability described below, and for example, dimethylurea based on the structure represented by the following formula [formula 18] is most preferable.

[0067]

Embedded image

The dimethylurea having the structure represented by Chemical Formula 18 includes DCMU-9 manufactured by Hodogaya Chemical Co., Ltd.
9. Omicure 94, Omicure 2 manufactured by BTR Japan
4, Omicure 52, and the like.

When the epoxy resin composition of the present invention has a viscosity at 60 ° C. of 5 Pa · sec or more, the tack of a prepreg using the epoxy resin composition becomes appropriate,
When it is Pa · sec or more, the tack of the prepreg becomes more appropriate.

Further, the epoxy resin composition of the present invention comprises
When the viscosity at ℃ is 5000 Pa · sec or less,
When the prepreg is formed, the reinforcing material has excellent impregnating property. When the prepreg is at 1000 Pa · sec or less, the reinforcing material has more excellent impregnating property.

Furthermore, the epoxy resin composition of the present invention
When left at 5 ° C for 3 weeks, the rate of thickening at 60 ° C is 2
When it is less than twice, the working life of the prepreg using this becomes longer.

The measurement of the viscosity of the epoxy resin composition at 60 ° C. is performed as follows. That is, using a DSR-200 manufactured by Rheometrics Inc. or a measuring instrument having equivalent performance, using two disk plates having a diameter of 25 mm under the condition of a shear speed of 10 radians / second, at a disk plate interval of 0.5 mm. From 50 ° C to 2
The temperature rise viscosity up to 70 ° C. was measured at a temperature rise rate of
Determine the value at 0 ° C. If the value at exactly 60 ° C. cannot be obtained, the value is complemented by two points sandwiching 60 ° C. Further, the rate of thickening at 60 ° C. is determined by measuring the viscosity of the epoxy resin composition for measurement before and after leaving it at 30 ° C. for 3 weeks.
It is determined by measuring according to the above method.

The epoxy resin composition of the present invention has a flexural modulus of 10 when cured at 90 ° C. for 2 hours.
When it is 0 MPa or more, it has a property that curing can be achieved more quickly so that it can be removed by primary curing at 90 ° C. or less, and when the flexural modulus is 300 MPa or more, it is even more rapid so that it can be removed. It has the property of hardening. The flexural modulus was measured according to JIS K7171.
Determined by bending test according to

Further, the epoxy resin composition of the present invention was subjected to primary curing at 90 ° C. for 2 hours, followed by 20 hours of curing.
When the glass transition temperature of the cured product obtained by performing the secondary curing at 0 ° C. for 4 hours is 150 ° C. or more, the cured product after the secondary curing is excellent in heat resistance and has high mechanical properties at high temperatures. When the glass transition temperature is 170 ° C. or higher, the heat resistance of the cured product after the secondary curing is further improved, and the mechanical properties at a high temperature are further improved.

The glass transition temperature of the cured product is determined as follows. That is, after subjecting a predetermined epoxy resin composition to primary curing at 90 ° C. for 2 hours,
A cured product is obtained by performing secondary curing at 0 ° C. for 4 hours. While gradually increasing the temperature of the obtained cured product, the storage elastic modulus E ′ or G ′ of the cured product at each temperature was measured, and the temperature at which the storage elastic modulus E ′ or G ′ began to rapidly decrease was determined. Defined as the glass transition temperature.

As shown in FIG. 1, when the logarithm of the storage elastic modulus E ′ or G ′ is plotted against the temperature, the tangent l ₁ of the slope when the cured product is in a glassy state is shown in FIG. And the temperature at the intersection A of the tangent l ₂ of the inclination when the cured product is in a state of transition from a glassy state to a rubbery state.

The storage elastic modulus E 'or G' is the tensile modulus or shear modulus of the cured product when the cured product is periodically strained. The storage modulus E ′ is, for example, RSA-II manufactured by Rheometrics, and G ′ is RD.
A-700 can be measured,
The temperature was raised stepwise by ° C, and measured at each temperature under the conditions of a soak time of 1 minute and a strain rate of 10 radians / second. still,
The glass transition temperature of the resulting cured product is the same whether it is from the storage modulus E 'or from G'.

Further, the epoxy resin composition of the present invention was subjected to a primary curing at 90 ° C. for 2 hours,
When the cured product was subjected to secondary curing at 4 ° C. for 4 hours, the retention (%) of the elastic modulus at 180 ° C. with respect to the elastic modulus at 30 ° C. of the cured product [elastic modulus at 180 ° C. × 100/30 ° C
Is 50 or more, the cured product after the secondary curing has excellent mechanical properties at high temperatures.

The method for measuring the elastic modulus is, for example, the same as the method for determining the glass transition temperature described above, by raising the temperature of the cured product from a temperature of 30 ° C. or less,
Measure up to above. In this case, the elastic modulus is the tensile elastic modulus E '.
Or the shear modulus G '.
By multiplying the value obtained by dividing the tensile modulus E 'at 30 ° C by the tensile modulus E' at 30 ° C by 100, the holding ratio of the elastic modulus at 180 ° C to the modulus at 30 ° C of the cured product (% ) [1
Elastic modulus at 80 ° C. × elastic modulus at 100/30 ° C.]. If the measured data at the exact temperature cannot be obtained, the elastic modulus at that temperature is determined by linear interpolation from the two nearest points sandwiching that temperature.

Various additives can be added to the epoxy resin composition of the present invention. For example, when a thermoplastic resin such as polyvinyl formal or phenoxy resin, polysulfone, or polyether sulfone is dissolved and added, or when an acrylic rubber, butyl rubber, or a rubber component such as butadiene rubber is added, a prepreg is formed. Good tack stability, good resin flow control when molding into FRP, and FRP after cured molding
The adhesiveness with the reinforcing material at the step is excellent, and the mechanical properties of the FRP are improved. Further, by adding highly elastic fine particles such as a silica compound such as Aerosil, the elastic modulus of the obtained cured product can be improved, and thus the interlayer shear and compressive strength of the obtained FRP can be improved.

In the prepreg using the epoxy resin composition of the present invention, the reinforcing material for impregnating the epoxy resin composition is not particularly limited, and for example, carbon fiber, glass fiber, metal fiber and the like can be used. . Also, the form of the reinforcing material is not particularly limited, and a unidirectional material, a cloth, a mat, or the like can be used. For example, a tow composed of thousands or more filaments is used as the reinforcing material, and the reinforcing material is made of epoxy resin. Tow prepreg impregnated with the composition is a preferred form of prepreg.

By selectively disposing a high toughness material such as a thermoplastic resin or a rubber component near the surface of the prepreg, the toughness between the layers of the obtained laminated cured product can be increased. Can be primarily cured at a low temperature of about 90 ° C., so even when a low melting point thermoplastic resin is arranged, it can be molded while maintaining its shape, and between layers, as designed. Quantity can be arranged. For this reason, it becomes a cured product having the interlayer toughness as designed. The form of the high-toughness material such as a thermoplastic resin or a rubber component to be disposed between the layers is not particularly limited. This is preferable because it can be arranged.

The method for preparing the epoxy resin composition of the present invention is not particularly limited. However, when a solid content such as a solid epoxy resin or a thermoplastic resin is dissolved and added, first, the dissolvable solids thereof are dissolved. It is preferable that the components are uniformly dissolved in a liquid epoxy resin before use.

The method of adding a latent curing agent that can be cured at 100 ° C. or less and constitutes the component (B) and has a stability coefficient of 2 or less is as follows. )), It is possible to prevent the secondary aggregation of the powdery component (B) and to uniformly disperse the component (B) by adding it into a paste once with a relatively low-viscosity epoxy resin or the like. This is preferred. When the component (B) is in a solid form other than the powder form, it is preferable to pulverize it into a powder form and then add it as a paste with a low-viscosity epoxy resin as described above. However, when the component (B) is a microcapsule-type curing agent, stirring with a strong shear will adversely affect the capsules and impair the stability at room temperature. Therefore, the microcapsule-type curing agent and a low-viscosity epoxy resin It is preferable to use a master batch type curing agent in which is uniformly mixed in advance.

The method of adding the acid anhydride-based or phenol-based curing agent constituting the component (C) is such that the component (C) is not dissolved by primary curing, that is, the melting point of the component (C) or the melting temperature of the epoxy resin. Is higher than the primary curing temperature, it is preferable to use the epoxy resin dissolved in the epoxy resin of the component (A) in advance. When the component (C) is in the form of a powder in which the component (C) is dissolved by the primary curing, a relatively low-viscosity epoxy resin or the like in the component (A) may be used as a paste to be added. This is preferable because the secondary aggregation of C) can be prevented and can be uniformly dispersed. or,
When the component (C) is in a solid form other than a powder form and is dissolved by primary curing, it is pulverized into a powder form and then made into a paste form with a low-viscosity epoxy resin or the like as described above. It is preferred to add. Further, when the component (C) is in a liquid state, it can be uniformly mixed by any method.

Since the epoxy resin composition of the present invention starts the reaction at a low temperature, after the addition of the latent curing agent constituting the component (B), the epoxy resin composition is kept at 70 ° C. or lower while preparing the epoxy resin composition. Is preferable for the stability of the epoxy resin composition at room temperature. When the composition is prepared while maintaining the temperature at 60 ° C. or lower, the stability of the epoxy resin composition at room temperature is further improved.

As a means for preparing a prepreg by impregnating a reinforcing material with the epoxy resin composition of the present invention, a hot melt method is preferable. When the epoxy resin composition of the present invention is applied to the release process paper, it is preferable to apply the epoxy resin composition at 70 ° C. or lower because the life of the prepreg is stabilized.
It is more preferable to apply the coating at a temperature of not more than ° C.

[0088]

EXAMPLES Hereinafter, the specific constitution of the epoxy resin composition of the present invention and a prepreg using the epoxy resin composition will be described based on examples. The abbreviations used in each of the examples, comparative examples, and tables are as follows. Ep828: Yuka Shell Co., Ltd., liquid bisphenol A type epoxy resin "Epicoat 828" Ep1001: Yuka Shell Co., semi-solid bisphenol A type epoxy resin "Epicoat 1001" TACTIX742: Dow Chemical Company, epoxy group in molecule "Tactics 742" polyfunctional epoxy resin having three or more Ep604: manufactured by Yuka Shell Co., Ltd., having three epoxy groups in the molecule
Multifunctional aminoglycidyl type epoxy resin "Epicoat 604" N-740: manufactured by Dainippon Ink and Chemicals, Inc. Multifunctional phenol novolak type epoxy resin "Epiclon N-740" having three or more epoxy groups in the molecule Ep1032: A multifunctional special novolak type epoxy resin "Epicoat 1032H60" having three or more epoxy groups in the molecule, manufactured by Yuka Shell Co., Ltd. N-670: Three or more epoxy groups in the molecule, manufactured by Dainippon Ink and Chemicals, Inc. Multifunctional cresol novolak type epoxy resin “Epiclon N-670” ELM-100: manufactured by Sumitomo Chemical Co., Ltd. Multifunctional aminophenol type epoxy resin “Sumi-Epoxy ELM-100” having three or more epoxy groups in the molecule AER4152: Modified epoxy resin "AER4" manufactured by Asahi Kasei Epoxy Corporation 152 "

HX3722: A latent curing agent for epoxy resin "NOVACURE HX372" manufactured by Asahi Kasei Epoxy Corporation
2); a paste-like curing agent having an active ingredient amount of 33% by mass FXE1000: a latent curing agent for epoxy resin manufactured by Fuji Chemical Co., Ltd. “Fujicure FXE1000” PN23: a latent curing agent for epoxy resin manufactured by Ajinomoto Co. "Amicure PN23" Omicure 94: manufactured by BTR Japan, the following formula
9] urea compound “Omicure 94”

[0090]

Embedded image

DCMU-99: a urea compound “DCMU-99” manufactured by Hodogaya Chemical Co., Ltd.

[0092]

Embedded image

Omicure 24: a urea compound "Omicure 2" represented by the following formula [Chem. 21] manufactured by BTR Japan.
4 "

[0094]

Embedded image

Omicure 52: A urea compound "Omicure 5" represented by the following formula [Chem. 22] manufactured by BTR Japan.
2 "

[0096]

Embedded image

NHN: Phenolic curing agent "Kayahard NHN" manufactured by Nippon Kayaku Co., Ltd. MTA-15: Acid anhydride-based curing agent "Ricacid MTA-15" manufactured by Shin Nippon Rika Co., Ltd. Dicy: Dicyandiamide T # 241: "Tomide # 241", a curing agent for epoxy resin manufactured by Fuji Kasei Co., Ltd. Aerosil: "Aerosil 300" manufactured by Aerosil Japan

Example 1 An example of the epoxy resin composition of the present invention having the composition shown in the predetermined column of the following [Table 1] was prepared.

When the curability of HX3722 constituting the component (B) was examined by the above-mentioned method using DSC,
The temperature at which the heat of curing started was 86 ° C., and curing was possible at 100 ° C. or less. In addition, the stability due to thickening after being left at 30 ° C. for 3 weeks was a stability coefficient of 1.1, the stability near room temperature was extremely large, and the composition had excellent latent reactivity.

The amount of the curing agent constituting the component (C) is
This is equivalent when the amount of the epoxy resin constituting the component (A) is 1 equivalent (the same applies hereinafter).

The preparation of the epoxy resin composition is carried out by using the component (A)
After the component (C) was added to the mixture and uniformly mixed, the component (B) was added and mixed uniformly.

Next, this epoxy resin composition was
The composition was subjected to primary curing at 2 ° C. for 2 hours to form a 2 mm-thick plate. In the predetermined column of [Table 1], the removability when the molded product was released was shown as “◎”.
"○": Indicates that the mold could be removed, "X": indicates that the mold could not be successfully removed due to bending or cracking.

Then, the plate as the primary cured product was
The glass plate was subjected to secondary curing at 4 ° C. × 4 hours, and the glass transition temperature Tg of the obtained cured plate was measured using RDS-7 manufactured by Rheometrics.
When determined by the temperature dispersion of G ′ due to 00, 18
5 ° C.

Examples 2 to 5 Examples of the epoxy resin composition of the present invention were prepared using the components shown in the predetermined columns of Table 1. The epoxy resin composition is prepared by adding the component (C) to the components other than the Ep828 in the component (A) and uniformly mixing the mixture, and then uniformly mixing the Ep828 and the Omicure 94 of the component (D) with three rolls. The mixed mixture and the component (B) were sequentially added and uniformly mixed.

The obtained epoxy resin composition was used in Example 1
The releasability at the time of the primary curing and the Tg of the cured product obtained after the secondary curing were measured in the same manner as described above, and are shown in the predetermined columns of [Table 1].

[0106]

[Table 1]

Examples 6 to 10 Examples of the epoxy resin composition of the present invention using the components shown in the predetermined columns of Table 2 were prepared by the same method as described in Example 1. .

The obtained epoxy resin composition was used in Example 1
The releasability at the time of the primary curing and the Tg of the cured product obtained after the secondary curing were measured in the same manner as described above, and are shown in the predetermined columns of [Table 2].

[0109]

[Table 2]

Examples 11 to 17 The epoxy resin compositions of the present invention were prepared using the components shown in the prescribed columns of Table 3. In addition, the curability of FXE1000 and PN23 used as the component (B) was examined in the same manner as in the method described in Example 1.
° C and 62 ° C. FXE1000 and PN23
The stability at room temperature was examined in the same manner as in the method described in Example 1. As a result, the stability coefficients were 1.2, respectively. Was.

The preparation of the epoxy resin composition is carried out by using the component (B)
And component (D) are uniformly dispersed in Ep828 in component (A) with a three-roll mill, and a mixture obtained by uniformly mixing the remaining components (A) and (C) is added thereto. The composition was uniformly mixed.

Further, the demolding property after the primary curing of each of the obtained epoxy resin compositions and the Tg of the cured product obtained by the secondary curing were evaluated in the same manner as described in Example 1. . The results are shown in [Table 3].

[0113]

[Table 3]

Comparative Example 1 An epoxy resin composition for comparison comprising the components shown in the prescribed columns of Table 4 was prepared. The operating procedure was the same as in Example 1 except that the addition of HX3722, which is the component (B) used in Example 1, was not performed.

When the removability of the obtained epoxy resin composition after the primary curing was evaluated in the same manner as described in Example 1, the epoxy resin composition was not cured by the primary curing.

Comparative Example 2 An epoxy resin composition for comparison comprising the components shown in the prescribed columns of Table 4 was prepared. The operating procedure was the same as in Example 1 except that the addition of MTA-15, which is the component (C) used in Example 1, was not performed.

Demoldability after primary curing of the obtained epoxy resin composition and Tg of the cured product obtained by secondary curing
Was evaluated in the same manner as described in Example 1. The results are shown in [Table 4].

Comparative Example 3 Dicy, a latent curing agent that does not cure at 100 ° C.
Was used to prepare an epoxy resin composition for comparison comprising the components shown in the predetermined columns of [Table 4]. The operation procedure is as follows. After adding the component (C) to the component (A) other than Ep828 and uniformly mixing the mixture, a mixture obtained by mixing Ep828, Dicy, and the Omicure 94 constituting the component (D) with three rolls is used. In addition, the mixture was mixed uniformly.

When the removability of the obtained epoxy resin composition after the primary curing was evaluated in the same manner as described in Example 1, the epoxy resin composition was not cured by the primary curing.

The activity of Dicy is improved when combined with a urea compound. However, according to the reactivity evaluation method described above, the temperature at which the exothermic curing starts is 115.degree.
It is not a curing agent that can be cured below 00 ° C.

[0121]

[Table 4]

Examples 18 to 20 Examples of the epoxy resin composition of the present invention were prepared using the components shown in the prescribed columns of Table 5. The preparation was carried out by dissolving PES in the component (A) at 150 ° C., lowering the temperature to 50 ° C., adding other components, and mixing uniformly.

The viscosity at 60 ° C. of each of the obtained epoxy resin compositions and the viscosity increase (times) at 25 ° C. × 3 weeks, 90
Flexural modulus of the cured product after primary curing at 200 ° C for 2 hours, T of cured product secondary cured at 200 ° C for 4 hours after primary curing
g, the retention rate (%) of the elastic modulus at 180 ° C. with respect to the elastic modulus at 30 ° C. of the cured product similarly subjected to the secondary curing was measured.

The Tg was measured based on the temperature dispersion of G '. The results are shown in [Table 5].

Comparative Example 4 An epoxy resin composition for comparison was prepared in the same manner as in Example 18 using the components shown in the prescribed columns of Table 5.

The degree of viscosity increase (fold) between the viscosity at 60 ° C. of the obtained epoxy resin composition and the viscosity at 60 ° C. after 3 weeks at 25 ° C. is also shown in Table 5. When this epoxy resin composition was subjected to primary curing at 90 ° C. for 2 hours, it did not cure.

As exemplified in Comparative Example 3, the activity of Dicy is improved when combined with a urea compound. However, according to the reactivity evaluation method described above, the temperature at which the exothermic curing starts is 115.degree. Not a hardening agent.

Comparative Example 5 An epoxy resin composition for comparison was prepared in the same manner as in Example 18 using a curing agent which had excellent curability at low temperatures but had no latent reactivity. That is, [Table 5]
An epoxy resin composition for comparison was prepared in the same manner as in Example 18 using the composition components shown in the predetermined columns. Evaluation of the obtained epoxy resin composition was performed in the same manner as in Example 18. The results are also shown in [Table 5].

Although T # 241 is a curing agent that reacts at 100 ° C. or lower, it is hardened after one day according to the evaluation of the latent reactivity of the curing agent itself, and T # 241 does not satisfy the condition that the stability coefficient is 2 or less. Absent. Therefore, the viscosity of the epoxy resin composition increased rapidly, and the epoxy resin composition was completely cured after 3 days at 25 ° C.

Comparative Example 6 An epoxy resin composition containing no component (C), that is, an epoxy resin composition for comparison with the composition shown in the prescribed column of [Table 5] was prepared in the same manner as in Example 18.
Evaluation of the obtained epoxy resin composition was performed in the same manner as in Example 18. The results are also shown in [Table 5].

Since the epoxy resin composition does not contain the component (C), the T
g was low, and the retention of the elastic modulus at 180 ° C. relative to the elastic modulus at 30 ° C. was also low.

[0132]

[Table 5]

Example 21 The epoxy resin composition obtained in Example 18 was applied to a resin having a basis weight of 125 g / m ² prepared by unidirectionally arranging Pyrofil carbon fiber TR50S-12L manufactured by Mitsubishi Rayon Co., Ltd. by a hot melt method. 30% of the content was impregnated to prepare a prepreg as an example of the present invention.

When the tack of the obtained prepreg was evaluated by tactile sensation, it was good with a moderate tack. Also,
Even after leaving this prepreg at 25 ° C. for 20 days,
It was confirmed that it had an appropriate tack and had a working life of 20 days or more.

Subsequently, one direction 2 using the prepreg
When the FRP panel having a thickness of mm was primarily cured at 90 ° C. for 2 hours, the releasability of the cured product was good.

Further, the removed panel was subjected to a secondary curing at 200 ° C. for 4 hours.
When the ILSS at 0 ° C. was measured according to ASTM D2344-84, as shown in the predetermined column of [Table 6],
It was confirmed that the mechanical properties at high temperatures were excellent.

Example 22 Using the epoxy resin composition of Example 19, a prepreg as an example of the present invention was prepared in the same manner as in Example 21. The obtained prepreg was used in Example 2
Evaluation was performed in the same manner as in Example 1. The results are shown in the predetermined columns of [Table 6].

Example 23 Using the epoxy resin composition of Example 20, a prepreg as an example of the present invention was prepared in the same manner as in Example 21. The obtained prepreg was used in Example 2
Evaluation was performed in the same manner as in Example 1. The results are shown in the predetermined columns of [Table 6].

Comparative Example 7 Using the epoxy resin composition of Comparative Example 5, a prepreg as a comparative example product of the present invention was prepared in the same manner as in Example 21. The obtained prepreg was prepared in Example 21
The evaluation was performed in the same manner as described above. The results are shown in the predetermined columns of [Table 6].

The working life of this prepreg was short, and tackiness was completely lost two days later, and the prepreg was hard and had a short working life.

Comparative Example 8 Using the epoxy resin composition of Comparative Example 6, a prepreg as a comparative example product of the present invention was prepared in the same manner as in Example 21. The obtained prepreg was prepared in Example 21
The evaluation was performed in the same manner as described above. The results are shown in the predetermined columns of [Table 6].

Since the epoxy resin composition used in this prepreg does not contain the component (C), the FRP after the secondary curing cannot measure ILSS at 150 ° C. Physical properties were low.

[0143]

[Table 6]

[0144]

As described in detail above, the epoxy resin composition of the present invention has excellent curability at a low temperature of 90 ° C. or lower, has excellent stability at room temperature, and has excellent stability at a high temperature. Subsequent curing results in a cured product having excellent heat resistance.

Therefore, the prepreg using the epoxy resin composition of the present invention has a long working life and good handling properties, and is so demolded by primary curing at a relatively low temperature of 90 ° C. or less. The FRP is cured in a short time and has excellent heat resistance due to secondary curing at a high temperature, and becomes a cured molded article having excellent properties at high temperatures.

[Brief description of the drawings]

FIG. 1 is a graph used to determine the Tg of a cured product from the intersection of the tangent of the graph in the glass state of the cured product and the tangent in the transition region.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4F072 AA07 AB10 AB22 AC02 AD27 AD28 AD30 AE01 AE04 AG02 AG13 AL04 4J036 AA05 AD00 AD18 AF03 AF11 AH04 DA05 DA06 DA10 DB06 DB15 DC18 DC25 DC31 HA07 JA11

Claims (32)

[Claims] 1. An epoxy resin composition comprising the following components (A), (B) and (C). (A) an epoxy resin containing a polyfunctional epoxy resin having three or more epoxy groups in a molecule; (B) a latent curing agent curable at 100 ° C. or less and having a stability coefficient of 2 or less (C ) Acid anhydride or phenolic curing agent 2. An epoxy resin composition comprising the following components (A), (B), (C) and (D). (A) an epoxy resin containing a polyfunctional epoxy resin having three or more epoxy groups in a molecule; (B) a latent curing agent curable at 100 ° C. or less and having a stability coefficient of 2 or less (C ) Acid anhydride-based or phenol-based curing agent (D) A curing accelerator comprising a urea compound 3. An epoxy group in a molecule in the component (A).
3. The epoxy resin composition according to claim 1, wherein the polyfunctional epoxy resin having at least one epoxy resin is an epoxy resin containing a diaminoglycidyl-type epoxy resin. 4. 4. An epoxy group in a molecule in the component (A).
The polyfunctional epoxy resin having at least one of the above is an epoxy resin containing a polyfunctional epoxy resin represented by the following formula [Chemical Formula 1]. The epoxy resin composition according to the above. Embedded image [Wherein, n represents an integer of 0 or more] 5. An epoxy group in a molecule in the component (A).
2. The polyfunctional epoxy resin comprising at least 50% by mass of all epoxy resins.
The epoxy resin composition according to claim 1. 6. An epoxy group in a molecule in the component (A).
2. The polyfunctional epoxy resin comprising at least 70% by mass of all epoxy resins.
The epoxy resin composition according to claim 1. 7. An epoxy group in the molecule in component (A)
The epoxy resin other than the multifunctional epoxy resin having at least one epoxy resin is a bisphenol A type epoxy resin and / or an epoxy resin containing an epoxy resin having an oxazolidone ring represented by the following formula [Formula 2]. The epoxy resin composition according to any one of claims 1 to 6, wherein Embedded image [Wherein, R represents a hydrogen atom or an alkyl group] 8. The epoxy resin composition according to claim 7, wherein the epoxy resin having an oxazolidone ring is an epoxy resin having a structure represented by the following formula [Formula 3]. Embedded image In the formula, R each independently represent a hydrogen atom or an alkyl group, R ₁ to R ₈ each independently represents a halogen atom, a hydrogen atom, or an alkyl group having 1 to 4 carbon atoms, R ₉ is the following formula [Representing a bifunctional group represented by the formula [4] or the formula [5]] Wherein R ′ _{1 to} R ′ ₄ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. [Wherein R ′ _{1 to} R ′ ₈ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and R ′ ₉ represents —CH ₂ —, —C
_{(CH 3) 2 -, -} SO 2 -, - SO -, - S- or -
O-] 9. The curing agent constituting the component (B) is a curing agent curable at 90 ° C. or lower.
The epoxy resin composition according to claim 8. 10. The method according to claim 1, wherein the curing agent constituting the component (B) is a latent curing agent having a stability coefficient of 1.5 or less. The epoxy resin composition according to the above. 11. The curing agent constituting the component (B) is a microcapsule type curing agent.
The epoxy resin composition according to claim 10. 12. The epoxy resin composition according to claim 1, wherein the curing agent constituting the component (B) is an amine adduct-type curing agent. . 13. The method according to claim 1, wherein the component (B) is mixed in an amount of 3 parts by mass or more with respect to 100 parts by mass of the component (A). The epoxy resin composition according to the above. 14. The method according to claim 1, wherein the component (B) is compounded in an amount of 5 parts by mass or more based on 100 parts by mass of the component (A). The epoxy resin composition according to the above. 15. The method according to claim 1, wherein the component (B) is blended in an amount of 20 parts by mass or less with respect to 100 parts by mass of the component (A). The epoxy resin composition according to the above. 16. The method according to claim 1, wherein the component (B) is blended in an amount of 10 parts by mass or less with respect to 100 parts by mass of the component (A). The epoxy resin composition according to the above. 17. Component (C) is added to component (A) in an amount of 0.
2. The composition according to claim 1, wherein the compound is blended in an amount of at least 4 times equivalent.
The epoxy resin composition according to any one of claims 16 to 16. 18. Component (C) is added to component (A) in an amount of 0.
2. The composition according to claim 1, wherein the compound is blended in an amount of 6 times equivalent or more.
The epoxy resin composition according to any one of claims 16 to 16. 19. Component (C) is added to component (A) for 1.
2. The composition according to claim 1, wherein the composition is blended in an amount of 5 equivalents or less.
The epoxy resin composition according to any one of claims 18 to 18. 20. Component (C) is added to component (A) in an amount of 1: 1.
2. The composition according to claim 1, wherein the compound is blended in an amount of 3 equivalents or less.
The epoxy resin composition according to any one of claims 18 to 18. 21. The curing accelerator according to claim 2, wherein the curing accelerator constituting the component (D) comprises a urea compound containing a compound represented by the following formula [6]. The epoxy resin composition according to claim 1. Embedded image 22. The epoxy resin composition according to claim 1, wherein the viscosity at 60 ° C. is 5 Pa · sec or more. 23. The epoxy resin composition according to claim 1, wherein the viscosity at 60 ° C. is 10 Pa · sec or more. 24. A viscosity at 60 ° C. of 5000 Pa · se
The epoxy resin composition according to any one of claims 1 to 23, wherein c is equal to or less than c. 25. A viscosity at 60 ° C. of 1000 Pa · se
The epoxy resin composition according to any one of claims 1 to 23, wherein c is equal to or less than c. 26. 60 ° C. when left at 25 ° C. for 3 weeks
26. The epoxy resin composition according to any one of claims 1 to 25, wherein the ratio of thickening is within 2 times. 27. The epoxy resin according to claim 1, wherein the cured product cured at 90 ° C. for 2 hours has a flexural modulus of 100 MPa or more. Composition. 28. The epoxy resin according to claim 1, wherein the cured product cured at 90 ° C. for 2 hours has a flexural modulus of 300 MPa or more. Composition. 29. The cured product obtained by curing at 90 ° C. for 2 hours and subsequently at 200 ° C. for 4 hours has a glass transition temperature of 150 ° C. or higher. 29. The epoxy resin composition according to any one of 28. 30. The cured product obtained by curing at 90 ° C. for 2 hours and subsequently at 200 ° C. for 4 hours has a glass transition temperature of 170 ° C. or higher. 29. The epoxy resin composition according to any one of 28. 31. A cured product cured at 90 ° C. for 2 hours and subsequently cured at 200 ° C. for 4 hours, and the elastic modulus at 180 ° C. relative to the elastic modulus at 30 ° C. (%) [ 18
Elastic modulus at 0 ° C. × elastic modulus at 100/30 ° C.] is 50 or more, the epoxy resin composition according to any one of claims 1 to 30. 32. A prepreg using an epoxy resin composition obtained by impregnating a reinforcing material with the epoxy resin composition according to any one of claims 1 to 31.