JPH09324031A - Epoxy resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an epoxy resin composition having low melt viscosity, good molding flow and excellent blocking resistance, storage stability, heat resistance, water resistance, etc., by using a crystalline epoxy resin showing a specified behavior of melting. SOLUTION: This composition comprises a crystalline epoxy resin and an epoxy resin curing agent. The epoxy resin used should be the one having at least two melting points including the melting point on the high temperature side and a melting point at least 10 deg.C below the highest melting point when measured by differential scanning calorimetry at a rise rate of temperature of 10 deg.C/min. It is desirable that the melting point on the high temperature side is 120 deg.C or above, and the melting point below at least 10 deg.C the melting point is 50 deg.C or above, among the at least two melting points as measured by differential scanning calorimetry at a rise rate of temperature of 10 deg.C/min. It is desirable that the crystalline epoxy resin contains an epoxy resin represented by the formula (wherein (n) is an integer of 0-5).

Description

Detailed Description of the Invention

[0001]

[0001] The present invention relates to an epoxy resin composition. More specifically, it has low viscosity when melted, good flowability, excellent blocking resistance, storage stability, and excellent physical properties such as heat resistance and water resistance, and is a sealing material for electronic parts, resin for electrical insulation, and powder. The present invention relates to an epoxy resin composition suitable for body paints and the like.

[0002]

2. Description of the Related Art Epoxy resins are widely used in various fields such as electric / electronics, paints, construction, civil engineering and adhesion due to their excellent properties. In particular, it has been widely used as a sealing material for electronic parts represented by IC because of its excellent electrical characteristics such as heat resistance and insulation characteristics. Epoxy resin compositions for conventional general electronic components, especially IC encapsulants, mainly contain various curing agents, fillers, pigments, etc. for o-cresol novolac type epoxy resin in accordance with various applications and target properties. It is used by blending and mixing, and then crushing or processing into a suitable shape.

However, the thickness of the IC has become thin due to the high density and miniaturization of electronic parts, and the conventional o-cresol novolac has been mounted by the mounting method to an electronic circuit in a high temperature atmosphere represented by solder reflow. It has become difficult to cope with the type epoxy resin composition. That is, in the case of encapsulating an IC having a small thickness and a large size, there is a problem in moldability such as damage to a fine circuit or defective molding due to poor flowability at the time of molding, or an electron in a high temperature atmosphere. In the method of mounting on a circuit, there have been problems with heat resistance due to moisture absorption such as cracks caused by rapid evaporation of moisture absorbed by the IC encapsulant due to thermal stress.

In order to improve such problems, a method of using a bifunctional crystalline epoxy resin composition having a low melt viscosity has been investigated. Since a bifunctional crystalline epoxy resin having a low melt viscosity is solid at room temperature, it is relatively easy to handle when it is made into a resin composition. The action is significantly reduced and the viscosity becomes low. Therefore, even in the case of a filler-filled resin composition that uses a large amount of an inorganic filler such as fused silica, which has excellent heat resistance and moisture resistance, it is possible to improve the flowability during molding processing, and as a result, the thickness becomes thin and large. It is also possible to seal the electronic components. Further, the problem of heat resistance due to moisture absorption is improved by the low hygroscopicity and heat resistance characteristics of the resin composition filled with a high amount of filler and the low elastic modulus of the resin composition due to the bifunctional epoxy resin.

Although the crystalline epoxy resin composition has such excellent properties, it has various properties depending on the balance between the melting temperature of the crystalline epoxy resin used and the production temperature in the step of obtaining the crystalline epoxy resin composition. There is a problem. That is, it is important for the crystalline epoxy resin composition to suppress the reaction between the epoxy resin and the epoxy resin curing agent in the step of obtaining the epoxy resin composition as much as possible in order to maintain high fluidity during molding. For the purpose of suppressing this reaction, there is a method in which the composition is manufactured at a temperature of 130 ° C. or lower, preferably 100 ° C. or lower. A resin composition using a crystalline epoxy resin that melts at such a manufacturing temperature is Long-term storage tends to cause blocking, which causes problems in handling.Storage stability such as long-term storage at room temperature decreases the flowability during molding and causes molding defects and damage to fine electronic components. There was a sexual problem.

There is also a method of suppressing the reaction between the epoxy resin and the epoxy resin curing agent by kneading at a temperature not higher than the melting temperature of the crystalline epoxy resin and not lower than the softening point of the epoxy resin curing agent. And the deterioration of flowability during melt processing with time are improved, but the workability during kneading is poor and the productivity is poor, and uniform mixing is difficult and the characteristics of the resulting cured product are adversely affected. There was a problem. As a means for solving these problems, a method of storing a crystalline epoxy resin composition at a low temperature and preventing a decrease in blocking property and flowability during melt processing over time has been conventionally performed, but it is energy cost-intensive. And is not a fundamental solution to the composition itself.

[0007]

As a result of various studies to solve the above-mentioned problems, the present inventors have used a crystalline epoxy resin exhibiting a specific melting behavior, and further, have a low viscosity during melting and flow. Both the workability during the production of the crystalline epoxy resin composition and the storage stability such as the blocking resistance and the deterioration of the flowability during the melt processing with time without deteriorating the characteristics of the crystalline epoxy resin having good properties. The present invention has been completed, and the object of the present invention is to have a low viscosity at the time of melting, good flowability at the time of molding, and excellent blocking resistance, storage stability, and heat resistance. Provided are an epoxy resin composition having excellent physical properties such as water resistance, and a method for producing the same.

[0008]

The gist of the present invention is an epoxy resin composition containing a crystalline epoxy resin and an epoxy resin curing agent, wherein the epoxy resin is heated by a differential scanning calorimeter at a heating rate of 10 A crystalline epoxy resin having at least two melting points when measured in ° C / min, and having a melting point on the highest temperature side of the two melting points and a melting point lower than that melting point by 10 ° C or more. Epoxy resin composition, which further comprises a crystalline epoxy resin having at least two melting points when measured with a differential scanning calorimeter at a temperature rising rate of 10 ° C./min, and a curing agent for the epoxy resin. In the method for producing a product, the epoxy is used in a temperature range not higher than the melting point temperature of the highest temperature side of the epoxy resin and not lower than the melting temperature of the melting point lower than the melting point by 10 ° C. or more. A method for producing an epoxy resin composition, characterized by prepared by mixing the fat and the epoxy resin curing agent.

That is, the present invention relates to a differential scanning calorimeter (hereinafter referred to as D
SC) and an epoxy resin composition containing a crystalline epoxy resin having at least two melting points when measured at a heating rate of 10 ° C./min, and an epoxy resin curing agent, wherein the crystalline epoxy resin is , Of the at least two melting points as measured by DSC at a heating rate of 10 ° C./min, the melting point on the highest temperature side (hereinafter referred to as “TmH”) and the melting point on the main low temperature side adjacent to the melting point (hereinafter referred to as “TmH”).
L ”) is used, and a crystalline epoxy resin having a temperature difference of 10 ° C. or more is used.

When a substance is heated at a constant rate using a differential scanning calorimeter to know the thermal characteristics of a substance, heat is absorbed or released due to phase change or thermal decomposition of the substance, and the horizontal axis indicates the temperature and the vertical direction. When a graph showing the amount of heat is drawn on the axis, for example, a peak accompanying absorption or release of heat as shown in FIG. 1 is shown. In the present invention, a crystalline epoxy resin having a melting point of at least two when measured by DSC at a temperature rising rate of 10 ° C./min is used, and an epoxy having such at least two melting points is used. The resin is composed of the same type of epoxy resin mixture having a different degree of polymerization, a different type of epoxy resin mixture having a different melting point, or a crystalline epoxy resin mixture such as a different type of epoxy resin mixture having a different degree of polymerization. In the present invention, it means that the difference between the melting point TmH on the highest temperature side among these melting points and the melting point TmL on the main low temperature side adjacent to TmH is 10 ° C. or more.

D of the crystalline epoxy resin used in the present invention
Of the two melting points measured by SC at a heating rate of 10 ° C./min, TmH is 120 ° C. or higher, and TmL is preferably 50 ° C. or higher. A crystalline epoxy resin is preferable. It is preferably an epoxy resin represented by the following general formula (I).

[0012]

Embedded image (In the formula, n represents a repeating unit represented by 0 or an integer of 5 or less.)

When a crystalline epoxy resin composition containing this crystalline epoxy resin is obtained, the production temperature is determined by DSC of the crystalline epoxy resin to raise the temperature by 10 ° C. /
By setting the temperature range below the melting temperature of TmH measured in minutes and above the melting temperature of TmL, the viscosity during melting is low, the flowability is good, and the blocking resistance and storage stability are excellent. It was possible to obtain an epoxy resin composition having excellent properties such as properties and water resistance.

Although the detailed action of such a crystalline epoxy resin composition is not clear, in order to improve the blocking property and the storage stability, a resin composition using a crystalline epoxy resin having a melting point of 120 ° C. or higher is used. The use of a crystalline epoxy resin having a melting point of 100 ° C. or lower is effective for producing the crystalline epoxy resin composition, and for workability and good moldability during production of the crystalline epoxy resin composition. Based on the results of the present inventors' examination that it is preferable, the melting behavior of a crystalline epoxy resin having a plurality of melting points was further observed by a DSC and a microscope observation device with a hot stage, and a specific melting point as in the present invention was obtained. In the melting behavior of the crystalline epoxy resin, if a component that melts at a low temperature in the crystalline component melts, a part of the crystalline component that exhibits a high melting point also dissolves in the molten crystalline component Rukoto, in particular, most if temperature side is at a temperature lower region 10 ° C. or higher than the melting point of the melting point component of the highest temperature side, be dispersed as fine particles not completely melted,
Furthermore, when the sample whose melting point component on the highest temperature side was not completely melted is cooled, it crystallizes quickly, but the melting point component on the highest temperature side is completely dissolved or melted, and the crystallinity is poor even after cooling. It turned out to say.

From these findings, in the present invention, a crystalline epoxy resin having a specific melting point is used, and when a resin composition is manufactured, by adopting a specific temperature condition, it is possible to obtain a melting point component having a temperature higher than the manufacturing temperature. It is presumed that one part melts and the other part exists as fine particles, which improves the workability during production, which was a problem of the crystalline epoxy resin composition having a high melting point, and was obtained after cooling. In the resin composition thus obtained, the melting point component at the manufacturing temperature or higher is rapidly recrystallized as fine particles, and therefore has excellent blocking properties, and further, when the crystalline epoxy resin such as room temperature storage is present as fine particles, the epoxy resin curing agent is used. It is considered that it has a low reactivity with and suppresses the deterioration of the flowability during molding over time. And, as a component of the crystalline epoxy resin in the present invention, 2,5-di-tert-butyl-1,4
The inclusion of diglycidyl ether of -dihydroxy-benzene is particularly preferable from the viewpoints of its melting point, good crystallinity, excellent heat resistance, water resistance, and flowability during melt processing.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The epoxy resin used in the present invention has at least two melting points when measured by DSC at a temperature rising rate of 10 ° C./min, and among the at least two melting points, the melting point on the highest temperature side ( TmH) and a melting point (TmL) adjacent to and lower than TmH by 10 ° C. or more. If the temperature difference between TmH and TmL is less than 10 ° C, the melting point component on the high temperature side easily melts at the same time as the melting point component having a low melting temperature is easily melted, and it is sufficient for the blocking property and the deterioration of the flowability during melt processing over time. There is a risk that the effect will not be obtained. Further, of the at least two melting points, TmH measured by DSC at a temperature rising rate of 10 ° C./min is preferably 120 ° C. or higher, and TmL is preferably 50 ° C. or higher.
However, if it is 120 ° C. or lower or TmL is 50 ° C. or lower, the problem of poor blocking resistance may occur.

The epoxy resin composition containing a crystalline epoxy resin having such a specific melting point can also be obtained by mixing a plurality of crystalline epoxy resins having different melting points. More specifically, the melting point is 12 as the crystalline epoxy resin component showing the highest melting point of the two melting points.
One or more known crystalline epoxy resins having a temperature of 0 ° C. or higher, and more preferably 130 ° C. or higher, and one or more known crystals having a melting point of 10 ° C. or lower than the melting point thereof and having a melting point of 50 ° C. or higher. It is obtained by mixing a hydrophilic epoxy resin. As a more specific example, 1,4-di-tert-butyl-2,5-bis (2,3-epoxypropoxy) -benzene having the melting point of 145 ° C. represented by formula (II) and formula (III) 1.4 which shows a melting point of 105 ° C.
For example, when 50 parts by weight of bis (2.3-epoxypropoxy) -benzene is melt mixed, a crystalline epoxy resin having two melting points of 135 ° C. and 95 ° C. is obtained.

[0018]

Embedded image

[0019]

Embedded image

Further, the above-mentioned mixing can be carried out in advance with only the crystalline epoxy resin to form the composition, or the mixing in the step of obtaining the crystalline epoxy resin composition is also possible. Further, in the method of obtaining an epoxy resin by reacting a phenol with an epihalohydrin in the presence of an alkali metal hydroxide, it is also possible to obtain by using two or more kinds of phenols capable of obtaining a crystalline epoxy resin having different melting points. Is. More specifically, the melting point on the highest temperature side of the present invention is 120 ° C. or higher, more preferably 130 ° C. or higher, and one or more phenols capable of obtaining a crystalline epoxy resin and a melting point lower than the melting point by 10 ° C. or more, and A crystalline epoxy resin having a melting point of 50 ° C. or higher is obtained by reacting a mixture of one or more phenols with epihalohydrin.

As a specific example, 2,5-di-tert-
Butyl-1,4-dihydroxy-benzene (hereinafter TBH
It can be obtained by reacting epichlorohydrin in the presence of an alkali metal hydroxide with 1,4-dihydroxybenzene as a phenol source. At this time, the amount of epichlorohydrin added is preferably in the range of 2.5 to 20 times the molar amount of the phenolic hydroxyl group. When the amount of epichlorohydrin added is 2.5 times or less, a large amount of oligomer is formed and it becomes difficult to obtain a crystalline epoxy resin, and when it is 20 times or more, the productivity becomes poor. The amount of alkali metal hydroxide added is preferably in the range of 0.7 to 1.5 times the molar amount of the phenolic hydroxyl group. When the amount of the alkali metal hydroxide added is 0.7 times or less, a large amount of an oligomer is formed and it becomes difficult to obtain a crystalline epoxy resin, and when it is 1.5 times or more, the productivity becomes poor.

Further, as an epoxy resin, 2,5-di-t
A specific epoxy resin having an ert-butyl-1,4-dioxy-benzene skeleton introduced thereinto has a high molecular symmetry and is prepared by mixing a compound in which the repeating unit n in the formula (I) is 1 or more at a specific ratio. A crystalline epoxy resin with two melting points is obtained. That is, 1,4-di-tert-butyl-2,5-bis (2,3-epoxypropoxy) -benzene represented by the formula (II) (a component of the repeating unit n = 0 in the general formula (I), n or less = 0 component), 1,3-bis [1-benzyl-2,5-di-tert-butyl-4- (2,3-epoxypropoxy)]-2-propanol represented by the formula (IV) An oligomer compound such as (a component of the repeating unit n = 1 in the general formula (I)) is also easily crystallized, and the synthesis condition is such that the amount of such an oligomer compound and the n = 0 component are produced in an appropriate ratio. By selecting, a crystalline epoxy resin having two melting points can be obtained.

[0023]

Embedded image

[0024]

[Chemical 6]

TBHB can be obtained by reacting epihalohydrin in the presence of an alkali metal hydroxide. At this time, it is necessary to use the amount of epihalohydrin added in a specific range of 1.3 to 2.5 times mol per mol of the phenolic hydroxyl group. When the amount of epichlorohydrin added is 1.3 times or less, an oligomer is produced in a large amount and TmH is 120 ° C. or less, which is not preferable. If it is 2.5 times or more, it has a single melting point of 135 ° C. or more, or the temperature difference between the two melting points is 1
It is less than 0 ° C, which is not preferable.

Further, among the crystalline epoxy resins, it is desirable to contain the diglycidyl ether of TBHB represented by the general formula (I). The use of diglycidyl ether of TBHB is known per se, and it has a characteristic of excellent flowability during molding and heat resistance and water resistance of the resulting cured product because of its extremely low viscosity during melting. However, the diglycidyl ether of TBHB which has been conventionally used as a crystalline epoxy resin composition has a high melting point, and in particular, the component of the repeating unit n = 0 in the formula (II) is 90% or less.
% Or more, a single melting point of 135 ° C. or higher is exhibited, and a crystalline epoxy resin composition using this alone has poor workability at the time of kneading when the step of obtaining the composition is performed at low temperature, resulting in poor productivity. It had inferior drawbacks. By blending a crystalline epoxy resin having such a high melting point with another crystalline epoxy resin having a low melting point, or by using a diglycidyl ether of TBHB produced by a production method having two melting points, The conventional problems can be improved.

As a method for producing the crystalline epoxy resin composition of the present invention, the raw material components selected in a predetermined composition ratio are
It can be obtained by mixing using a hot roll, a heating kneader, an extruder or the like, and pulverizing if necessary. The production temperature is 10 ° C /
It is preferable to manufacture the crystalline epoxy resin at a temperature not higher than the TmH temperature measured in minutes and not lower than the TmL temperature. When the crystalline epoxy resin is produced at a temperature higher than the TmH temperature, the reaction between the epoxy resin and the epoxy resin curing agent is likely to proceed, and the flowability during molding may be poor. Further, if the crystalline epoxy resin is produced at TmL or less, the workability at the time of kneading is poor, the productivity is deteriorated, and uniform mixing is difficult, which is not preferable.

The epoxy resin used in the present invention is obtained by reacting a part of the terminal epoxy groups with monophenols, carboxylic acids and secondary amines within a range that does not impair the effects and physical properties of the composition of the present invention. Can also be used.
It is also possible to use a small amount of other non-crystalline epoxy compound in combination within a range that does not impair the effects and physical properties of the composition of the present invention. Various curing agents can be used in the present invention. For example, novolac type phenolic resins obtained by condensation reaction of phenols such as phenol, cresol, bisphenol A, naphthol and aldehydes such as formaldehyde. Aralkylphenol resins obtained by condensation reaction of phenols with aralkyls such as paraxylene glycol. Phenolic resins obtained by a condensation reaction of a phenol and a compound containing an unsaturated bond such as dicyclopentadiene. Linear phenolic resins having phenolic hydroxyl groups at both ends. Examples thereof include dicyandiamide, imidazoles, hydrazides, acid anhydrides and modified products thereof, and aromatic amines and modified products thereof. In the crystalline epoxy resin composition of the present invention, the mixing ratio of the curing agent to the epoxy resin is such that the functional group of the curing agent is 0.5 to 1 equivalent of epoxy group.
The ratio is 1.5 equivalents, preferably 0.8 to 1.2 equivalents.

The crystalline epoxy resin composition of the present invention may contain a filler, a curing accelerator and various additives, if necessary. As a filler, for example, fused silica powder, alumina powder, magnesia powder, titanium oxide,
Examples thereof include talc, red iron oxide, mica, and calcium carbonate. Examples of the curing accelerator include tertiary amines, imidazoles, quaternary ammonium salts, phosphines, and the like. Other additives include, for example, organic pigments, flame retardants, flow control agents, internal release agents and the like.

[0030]

[Effects of the Invention] When a crystalline epoxy resin exhibiting a specific melting point behavior as described above is used, and when a crystalline epoxy resin composition is obtained, the viscosity at the time of melting is improved by manufacturing under a specific processing condition. Low and good flowability Without impairing the properties of crystalline epoxy resin, workability during production of crystalline epoxy resin composition and block stability, and storage stability such as deterioration of flow production during melt processing over time. An epoxy resin composition having improved properties was obtained.

[0031]

The present invention will be described in more detail with reference to examples of epoxy resin composition, but the present invention is not limited to these examples. In addition, "parts" described in the following examples means "parts by weight" unless otherwise specified. In addition, the melting point shown below is 10 ° C /
It is the value when measured in minutes. Table 1 shows the epoxy resins used in Examples and Comparative Examples. “Epoxy resin A”, “epoxy resin B” and “epoxy resin C” in Table 1 are diglycidyl ethers of 2,5-di-tert-butyl-1,4-dihydroxy-benzene (TBHB). It has the indicated epoxy equivalents and different melting points. “Epoxy resin D” and “epoxy resin E” are TBHB diglycidyl ether 1 having a melting point of 142 ° C.
It was obtained by melting and mixing 20 parts of 1,4-dihydroxy-benzene diglycidyl ether (melting point 105 ° C.) and 1,4-dihydroxynaphthalene diglycidyl ether (melting point 90 ° C.) in 00 parts. Have different epoxy equivalents and different melting points. “Epoxy resin F” is a T having a melting point of 142 ° C., which has an epoxy equivalent shown in Table 1.
It is a diglycidyl ether of BHB, and "epoxy resin G" is a diglycidyl ether of 1,4-dihydroxy-benzene having an epoxy equivalent shown in Table 1 and a melting point of 105 ° C. "Epoxy resin H" is diglycidyl ether of 1,4-di-hydroxy-benzene (melting point 105
C.) was obtained by melt-mixing 100 parts of diglycidyl ether of 1,4-dihydroxynaphthalene (melting point 90.degree. C.) with 20 parts and having epoxy equivalents shown in Table 1 and different melting points. Then, the DSC of "epoxy resin A" is shown in FIG.
Shown in

[0032]

[Table 1]

Examples 1 to 5 and Comparative Examples 1 to 3 The epoxy resins shown in Table 1 were used, the additives were blended in the proportions shown in Table 2, and the additives were premixed and then placed in a kneader. Then, the mixture was kneaded at 100 ° C., cooled, and pulverized to obtain the desired crystalline epoxy resin composition. 1) to 3) in Table 2 are as follows. 1) Showa High Polymer Co., Ltd. BRG-555 softening point 65 ° C
Hydroxyl equivalent 105g / eq 2) YDB-360 epoxy equivalent 36 manufactured by Tohto Kasei Co., Ltd.
0 g / eq brominated bisphenol A type epoxy resin 3) diantimony trioxide

[0034]

[Table 2]

Various physical properties of the crystalline epoxy resin composition prepared according to Table 2 were examined and the results are shown in Table 3. The measurement methods and evaluation methods of physical properties in Table 3 are as follows. 1. Workability during production of epoxy resin composition The kneading state and the flowability state of the composition were evaluated by the following criteria with a kneader. Good: Good kneading and composition flow. C: The kneading condition is good, but the composition flow is slightly poor. × ・ ・ ・ ・ Kneading is insufficient and composition flow is poor. 2. Blocking resistance The crystalline epoxy resin composition was evaluated for the blocking state when stored for 10 days in a constant temperature bath at 40 ° C. according to the following criteria. ○ ・ ・ ・ ・ It does not become a lump and has fluidity. △ ・ ・ ・ ・ It does not become a large lump, but it has no fluidity. × ・ ・ ・ ・ It becomes a lump and has no fluidity. 3. Flowability at the time of molding The flowability at the time of molding of the crystalline epoxy resin composition was stored at 25 ° C. for 1 day and in a thermostatic chamber at 40 ° C.
The spiral flow with that stored for 0 days was measured and the change was determined by the following formula. 4. Glass transition temperature It was determined by thermomechanical analysis (TMA) of the cured product when each molded product was cured at 180 ° C. for 8 hours. 5. Water absorption rate A disc-shaped molded product with a diameter of 50 mm and a thickness of 2 mm was changed in weight after 120 hours at 121 ° C and 100% RH using a pressure cooker tester.

[0036]

[Table 3]

As is clear from the results shown in Table 3, the crystalline epoxy resin composition obtained according to the present invention has good workability during the production of the composition, blocking resistance and flowability during melt processing. It can be seen that the storage stability is excellent such that there is little deterioration over time.

[Brief description of drawings]

FIG. 1D of “epoxy resin A” used in Example 1
SC is shown.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshitaka Ban, 3-17-14 Higashikasai, Edogawa-ku, Tokyo Inside Tohsei Kagaku Co., Ltd. (72) Inventor Takako Otaki, 3-17-, Higashikasai, Edogawa-ku, Tokyo 14 Toto Kasei Co., Ltd.

Claims (4)

[Claims] 1. An epoxy resin composition containing a crystalline epoxy resin and an epoxy resin curing agent, wherein the epoxy resin contains at least two when measured by a differential scanning calorimeter at a heating rate of 10 ° C./min. An epoxy resin composition which has a melting point and is a crystalline epoxy resin having a melting point on the highest temperature side of the two melting points and a melting point lower than the melting point by 10 ° C. or more. 2. Of the at least two melting points of the crystalline epoxy resin measured by a differential scanning calorimeter at a temperature rising rate of 10 ° C./minute, the melting point on the highest temperature side is 120 ° C. or higher, which is lower than the melting point by 10 ° C. or higher. The epoxy composition according to claim 1, which has a melting point of 50 ° C or higher. 3. The epoxy composition according to claim 1, wherein the crystalline epoxy resin contains an epoxy resin represented by the general formula (I). Embedded image (In the formula, n represents a repeating unit represented by 0 or an integer of 5 or less.) 4. A temperature rising rate of 10 ° C./by a differential scanning calorimeter
In a method for producing an epoxy resin composition containing a crystalline epoxy resin having at least two melting points and a curing agent for the epoxy resin when measured in minutes, at a melting point temperature on the highest temperature side of the epoxy resin or less, and A method for producing an epoxy resin composition, which comprises mixing a crystalline epoxy resin and a curing agent for the epoxy resin in a temperature range not lower than the melting point and not lower than the melting temperature by 10 ° C. or higher.