JPH11292955A - Epoxy resin composition and cured product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain both an epoxy resin composition excellent in handleability and preservation stability in a solid state and capable of providing a cured product excellent in moldability, low hygdroscopicity, high heat resistance and high adhesion, or the like, to materials of different kinds, further excellent in electrical insulating properties and improved in blocking resistance, and the cured product thereof. SOLUTION: This epoxy resin composition is obtained by compounding 100 pts.wt. of an o-cresol novolak type epoxy resin with <=10% content of a dimer with 10-100 pts.wt. of a bifunctional type epoxy resin having 180-300 epoxy equiv. and 0.05-0.5 P melt viscosity at 150 deg.C and 5-100 pts.wt. of a thermoplastic aromatic oilgomer having 70-150 deg.C softening point. Furthermore, the epoxy resin composition contains, besides the epoxy resin composition, a phenolic curing agent and >=75 wt.% of an inorganic filler. The cured product of the epoxy resin is obtained by curing the resultant epoxy resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention is excellent in moldability, low hygroscopicity, as well as excellent handleability and storage stability in solid.
Epoxy resin composition useful for encapsulation of electric and electronic parts with improved blocking resistance that gives cured products with high heat resistance and excellent adhesion to dissimilar materials and excellent electrical insulation, and circuit board materials And a cured product thereof.

[0002]

2. Description of the Related Art Conventionally, epoxy resins have been industrially used for a wide range of applications, but their required performance has been increasingly sophisticated in recent years. For example, semiconductor encapsulation materials are a typical field of resin compositions containing an epoxy resin as a main component, but with the improvement in the degree of integration of semiconductor elements, package sizes have become larger and thinner. The shift to surface mounting is progressing, and the development of a material having excellent solder heat resistance is desired. Influential methods for improving solder heat resistance include lowering the water absorption and improving the adhesion at the interface between different materials such as lead frames and chips.

[0003] In order to reduce the water absorption, the filling rate of the inorganic filler is increased, and a low-viscosity epoxy resin is desired. From these backgrounds, an epoxy resin for a semiconductor encapsulant using a bifunctional epoxy resin such as a biphenyl-based epoxy resin (Japanese Patent Publication No. 4-73565) and a bisphenol F-type epoxy resin (Japanese Patent Application Laid-Open No. 6-345850). Compositions have been proposed. These epoxy resins are excellent in low viscosity, high filler filling rate, and improved fluidity, but are inferior in handling properties such as compound blocking resistance and storage stability, and due to bifunctionality. It is difficult to increase the crosslink density, the hardness and the glass transition point of the cured product are reduced, and the moldability and heat resistance are reduced.

As epoxy resins having excellent moldability and heat resistance, polyfunctional o-cresol novolak type epoxy resins have been widely used, but they have a disadvantage of high viscosity and have a high filler filling rate. Had limitations. Therefore, the lowering of the molecular weight of the o-cresol novolak type epoxy resin has been studied, and a resin having a melt viscosity of 150 ° C. and a poise of 1 poise or less has been proposed. There is a problem that gets worse. In addition, as a material having low viscosity and improved blocking resistance, a material having a reduced bifunctional component and a high molecular weight material and a sharp molecular weight distribution has been proposed, but the adhesiveness is reduced. There was a problem.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an epoxy resin composition having excellent blocking resistance. In addition, it is excellent in handling properties in solid, storage stability and moldability. An epoxy resin composition having low moisture absorption, high heat resistance, excellent adhesion to dissimilar materials, and the like, and providing a cured product having excellent electrical insulation, improved blocking resistance, and a cured product thereof. It is in.

[0006]

Means for Solving the Problems The present inventors have found that while the bifunctional component greatly contributes to the improvement of the adhesion at the interface between different materials and the improvement of the fluidity, the blocking resistance is reduced, and the high molecular weight component is resistant. While contributing to the blocking property and improved heat resistance, considering that the fluidity is reduced, combining a specific difunctional epoxy resin with a low dimer content o-cresol novolak type epoxy resin, and further specific By combining aromatic oligomers, it has been found that excellent moldability, high heat resistance, low water absorption and high adhesion are exhibited while maintaining excellent solid handling properties and storage stability. Reached.

That is, according to the present invention, the content of the dimer is 1
100% by weight of o-cresol novolak type epoxy resin of 0% or less, epoxy equivalent of 180 to 300, 15
10 to 100 parts by weight of a bifunctional epoxy resin having a melt viscosity at 0 ° C. of 0.05 to 0.5 poise, and a softening point of 7
Thermoplastic aromatic oligomer 5-1 at 0 to 150 ° C.
An epoxy resin composition containing 00 parts by weight,
An epoxy resin composition containing the epoxy resin composition, a phenolic curing agent, and 75% by weight or more of an inorganic filler, and a cured epoxy resin product obtained by curing the epoxy resin composition.

The production method of the o-cresol novolak type epoxy resin used in the present invention is not particularly limited, but the content of the dimer needs to be 10% or less, preferably the dimer. Is 7% or less. If the content of the dimer is more than this, the blocking resistance of the epoxy resin composition decreases.

[0009] The content of the trimer or higher component is not particularly limited except that it may exceed 90%, but the preferable content of the hexamer or higher is from the viewpoint of improving the hardness and heat resistance of the cured product. Is at least 50%, more preferably at least 60%. The content of each component mentioned here was determined by GPC measurement, and the measurement conditions were as follows: Apparatus: HLC-82A
(Manufactured by Tosoh Corporation), column: TSK-GEL 2000 x 3 and
TSK-GEL4000 x 1 (all manufactured by Tosoh Corporation), solvent:
Tetrahydrofuran, flow rate: 1.0 ml / min, temperature: 3
8 ° C., detector: RI.

The softening point of the o-cresol novolak type epoxy resin is preferably from 60 to 120 ° C, more preferably from 70 to 100 ° C. This softening point is 60
When the temperature is lower than 0 ° C, the blocking resistance of the epoxy resin composition decreases. When the temperature is higher than 120 ° C, the fluidity during molding decreases, and it becomes difficult to increase the filling rate of the filler.

The o-cresol novolak type epoxy resin having a low dimer used in the present invention has a low dimer content.
It may be produced by reacting a cresol novolak resin with epichlorohydrin, or may be produced by producing an epoxy resin and then removing dimerized epoxide by a method such as molecular distillation.

The structure of the bifunctional epoxy resin used in the present invention is not limited, but the epoxy equivalent is 180 to 300 and the melt viscosity at 150 ° C. is 0.05 to 0.5 poise. It needs to be. If the epoxy equivalent and the melt viscosity are smaller than this, the effect of improving the blocking resistance is small, and if it is larger than this, the fluidity at the time of molding decreases, the crosslinking density decreases, and the hot hardness and heat resistance of the cured product decreases. I do.

Preferred bifunctional epoxy resins include:
For example, 3.3 ', 5,5'-tetramethyl-4,4'-
Epoxidized dihydroxydiphenylmethane, 2,
2 ', 3,3', 5,5'-Hexamethyl-4,4'-
Epoxidized dihydroxydiphenylmethane, 2,
2'-dimethyl-5,5'-ditertbutyl-4,
Epoxidized 4'-dihydroxydiphenylmethane,
Epoxidized 1,4-bis (4-hydroxycumyl) benzene, epoxidized 1,4-bis (3-methyl-4-hydroxycumyl) benzene, 1,4-bis (3,
Epoxidized product of 5-dimethyl-4-hydroxycumyl) benzene, epoxidized product of 2,2'-dimethyl-5,5-ditertbutyl-4,4'-dihydroxydiphenyl sulfide, 3,3 ', 5,5'- Tetramethyl-
Epoxidized 4,4'-dihydroxybiphenyl and the like can be mentioned. These bifunctional epoxy resins may be used alone or in combination of two or more.

The mixing ratio of the bifunctional epoxy resin is o-
It is 10 to 100 parts by weight, preferably 20 to 80 parts by weight, based on 100 parts by weight of the cresol novolac type epoxy resin. If the amount is less than this, the fluidity at the time of molding is reduced, and the effect of improving the adhesion of the cured product at the interface between different materials is small. On the other hand, if the amount is more than this, the blocking resistance is reduced, the crosslinking density is reduced, and the hardness at the time of heat and the heat resistance of the cured product are reduced.

The purity of the epoxy resin used in the present invention, particularly the amount of hydrolyzable chlorine, is preferably smaller from the viewpoint of improving the reliability of the electronic component to be sealed. Although not particularly limited, 1000 ppm or less is preferable. In addition, the hydrolyzable chlorine referred to in the present invention refers to a value measured by the following method. That is, 0.5 g of a sample is placed in 30 ml of dioxane.
After adding 10 ml of 1N-KOH and boiling under reflux for 30 minutes, the mixture was cooled to room temperature, further added with 100 ml of 80% acetone water, and subjected to potentiometric titration with a 0.002 N-AgNO ₃ aqueous solution.

As the aromatic oligomer used in the present invention, any thermoplastic oligomer having an aromatic structure can be used. For example, styrene, alkylstyrenes, α
Oligomers derived from aromatic vinyl monomers such as methylstyrene, indene, methylindene, cumarone, benzothiophene, vinylnaphthalenes, vinylbiphenyls, acenaphthylene, 2,6-xylenol,
Examples include polyphenylene oxide oligomers, polyphenylene sulfide oligomers, and aromatic polyester oligomers obtained by polymerizing 2,6-disubstituted phenols such as 2,6-diphenylphenol. Industrially, styrene resin, indene resin, indene styrene resin, indene maron resin, indene maron styrene resin, petroleum resin and the like can be mentioned as typical examples.

Among these aromatic oligomers, preferred are oligomers derived from aromatic vinyl monomers, and more preferably those obtained by polymerizing monomers containing indene as a main component. It is preferable that the content of the indenes is 50% by weight or more. When synthesizing the oligomer from the aromatic vinyl monomer, a vinyl monomer other than the aromatic monomer may be copolymerized. Examples of the copolymerizable monomer include monomers having an unsaturated bond such as acrylic acid, acrylic esters, methacrylic acid, methacrylic esters, maleic anhydride, fumaric acid, divinylbenzenes, and diisopropenylbenzene. Can be

The method for producing the aromatic oligomer is not limited.
Any method such as radical polymerization, cationic polymerization, and anionic polymerization may be used, but cationic polymerization is generally preferred. At this time, phenol compounds such as alkylphenols such as phenol and cresol, dialkylphenols such as xylenol, and naphthols may be added as a cation trapping agent. Usually, the addition amount of these phenol compounds is 20% by weight or less based on all monomer components. If it is more than this, the heat resistance and the moisture resistance of the cured epoxy resin are reduced.

The aromatic oligomer used in the present invention has a softening point of 70 to 150 ° C., preferably 80 to 130 ° C., and a melt viscosity at 150 ° C. of 2 to 200 poise, preferably 5 to 100 poise. Melt viscosity and softening point are
If it is lower than this, the effect of improving blocking resistance is small,
If it is higher than this, the fluidity during molding decreases. The molecular weight of this aromatic oligomer is 300 to 300 in number average molecular weight.
It is about 0.

The aromatic oligomer used in the present invention preferably has a high purity and a small content of ionic components. In particular, those having a small amount of alkali metal ions such as sodium and potassium and a small amount of halogen ions such as chloride ion and bromide ion are preferable. The content of the alkali metal ion and the halogen ion is 30 ppm or less, preferably 10 ppm or less.
ppm or less.

The mixing ratio of the aromatic oligomer used in the present invention is o-cresol novolak type epoxy resin 100
5 to 100 parts by weight, preferably 20 to 8 parts by weight with respect to parts by weight
0 parts by weight. If the amount is less than this, the fluidity at the time of molding is reduced, the effect of improving the blocking resistance is small, and the effect of reducing the water absorption of the cured product and the effect of improving the adhesion at the interface between different materials are small. On the other hand, if the amount is more than this, the hardness at the time of heat and the heat resistance of the cured product decrease, and the flame retardancy also decreases.

The epoxy resin composition of the present invention comprises the above o
-It can be prepared by mixing a cresol novolak type epoxy resin, a bifunctional type epoxy resin and an aromatic oligomer. The mixing method may be melt mixing or a method of dissolving and mixing in a solvent and then removing the solvent. As a solvent when using a solvent, for example, methanol, ethanol, propanol, butanol, ethylene glycol,
Alcohols such as methyl cellosolve and ethyl cellosolve, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, benzene, toluene, xylene,
Examples thereof include aromatic solvents such as chlorobenzene and dichlorobenzene.

The epoxy resin composition of the present invention may contain a normal epoxy resin having two or more epoxy groups in the molecule, in addition to the above-mentioned epoxy resin composition which is blended as an essential component. Examples include divalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcin, and tris- (4-hydroxyphenyl). methane,
Glucidyl ether derived from trivalent or higher phenols such as 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolac, and halogenated bisphenols such as tetrabromobisphenol A And the like. These epoxy resins may be used alone or in combination of two or more. The amount of these components may be within a range that does not impair the object of the present invention, but is usually within 50% by weight of the essential epoxy resin composition.

If the epoxy resin composition is mixed with a phenolic curing agent and a filler, an excellent cured product is obtained as a sealing material. As the phenolic curing agent, a conventionally known epoxy resin curing agent such as phenol novolak can be used, and a polyhydric phenolic curing agent having an aralkyl-type structure can be used. A polyhydric phenol-based curing agent having an aralkyl-type structure is produced by reacting a phenolic hydroxyl group-containing compound having an alkyl-substituted or unsubstituted benzene ring or a naphthalene ring with a specific aromatic crosslinking agent. .

Further, as the polyhydric phenol-based curing agent,
For example, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone,
2 of resorcinol, catechol, naphthalene diols, etc.
Phenols, such as tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak, naphthol novolak, and polyvinyl phenol. Trivalent or higher phenols,
Furthermore, phenols, naphthols or bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,
2'-biphenol, hydroquinone, resorcin, catechol, naphthalene diols and other divalent phenols and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, p-xylylene glycol, p-xylylene glycol dimethyl ether, divinylbenzene, divinylbenzene Examples include polyhydric phenolic compounds synthesized by reaction with a crosslinking agent such as isopropenylbenzene, dimethoxymethylbiphenyls, divinylbiphenyl, diisopropenylbiphenyls, and the like. These curing agents may be used alone or in combination of two or more.

The softening point of the phenolic curing agent is preferably 40 to 150 ° C, more preferably 50 to 120 ° C.
It is. If it is lower than this, there is a problem of blocking during storage, and if it is higher than this, there is a problem in kneadability and moldability in preparing the epoxy resin composition. The melt viscosity at 150 ° C. is preferably 20 poise or less, more preferably 5 poise or less. If it is higher than this, there are problems in kneadability and moldability during the preparation of the epoxy resin composition.

The mixing ratio of the phenolic curing agent in the epoxy resin composition containing the curing agent may be within the range usually employed, but preferably the phenolic hydroxyl group is 0.7 to 1 per mole of epoxy group. It is preferable to mix them so as to be 0.2 mol.

Examples of the inorganic filler to be added to the epoxy resin composition of the present invention include silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, One or more of mullite, titania and the like may be mentioned, and examples of the form include powder and spherical beads. Of these, spherical fused silica is preferred from the viewpoint of increasing the packing of the inorganic filler. Usually, silica is used in combination with one having several types of particle size distribution. The range of the average particle size of the silica to be combined is
0.5 to 100 μm is preferred.

The compounding amount of the inorganic filler in the epoxy resin composition of the present invention is at least 75% by weight, preferably at least 80% by weight of the whole epoxy resin composition. If less than this, the effect of improving the solder heat resistance is small.

The epoxy resin composition of the present invention may contain conventionally known curing accelerators such as amines, imidazoles, organic phosphines, Lewis acids and the like. Specifically, 1,8-diazabicyclo (5,4,
0) tertiary amines such as undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 2-methylimidazole,
Imidazoles such as phenylimidazole, 2-phenyl-4-methylimidazole and 2-heptadecylimidazole; organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine and phenylphosphine; and tetraphenylphosphonium. Tetra-substituted phosphonium / tetra-substituted borate such as tetraphenyl borate, tetraphenyl phosphonium / ethyl triphenyl borate, tetrabutyl phosphonium / tetrabutyl borate, 2
And tetraphenylboron salts such as -ethyl-4-methylimidazole / tetraphenylborate and N-methylmorpholine / tetraphenylborate. The addition amount is usually 0.2 to 10 parts by weight based on 100 parts by weight of the epoxy resin.

Further, the epoxy resin composition of the present invention comprises:
Release agents such as carnauba wax and ester wax, coupling agents such as epoxy silane, amino silane, ureido silane, vinyl silane, alkyl silane, organic titanate, aluminum alcoholate, coloring agents such as carbon black, and difficulties such as antimony trioxide A low-stressing agent such as a combustion aid, silicone oil, or a lubricant such as a higher fatty acid or a metal salt of a higher fatty acid may be blended.

In general, the above-mentioned raw materials are sufficiently mixed in a predetermined mixing amount by a mixer or the like, kneaded by a mixing roll, an extruder, etc., cooled, and pulverized to obtain an epoxy resin for a molding material. A composition can be prepared.

As a method for sealing an electronic component using the molding material obtained in the present invention, a low-pressure transfer molding method is the most common, but an injection molding method or a compression molding method is also possible. .

[0034]

The present invention will be described more specifically with reference to examples and comparative examples. Reference Example 1 [Synthesis example of aromatic oligomer A] 70 g of indene, 25 g of styrene, and 5 g of phenol were dissolved in 250 g of toluene and heated to 115 ° C. Thereafter, while stirring, 1 g of boron trifluoride dimethyl ether complex was added dropwise over 15 minutes. After the addition, the reaction was further performed for 3 hours. Thereafter, 2.4 g of calcium hydroxide
And neutralized. Neutralized salts and excess calcium hydroxide are removed by filtration, and the mixture is further diluted with 100 ml of ion-exchanged water.
After repeating the washing twice, toluene and unreacted monomers were removed by distillation under reduced pressure to obtain 89 g of an aromatic oligomer. The obtained resin had a softening point of 98 ° C. and a melt viscosity at 150 ° C. of 8 poise.

Reference Example 2 [Synthesis example of aromatic oligomer B] The reaction was carried out in the same manner as in Reference Example 1 except that the reaction temperature was 90 ° C to obtain 92 g of an aromatic oligomer. The softening point of the obtained resin is 1
It was 18 ° C and the melt viscosity at 150 ° C was 64 poise.

Examples 1 to 5 and Comparative Examples 1 to 5 As OCNE type epoxy resins, O-type epoxy resins having a softening point of 90 ° C.
Cresol-novolak type epoxy resin (epoxy resin A: epoxy equivalent 200, hydrolyzable chlorine 400 pp)
m, 150 ° C. melt viscosity 11 poise, dimer content 4.7
%), An o-cresol-novolak type epoxy resin having a softening point of 65 ° C. (epoxy resin B: Nippon Kayaku, EOCN-1020-6)
5: Epoxy equivalent 200, hydrolyzable chlorine 400 pp
m, 150 ° C. melt viscosity 3 poise, dimer content 8.5
%), An O-cresol-novolak type epoxy resin having a softening point of 55 ° C. (epoxy resin C: Nippon Kayaku, EOCN-1020-5)
5: Epoxy equivalent 200, hydrolyzable chlorine 400 pp
m, 150 ° C. melt viscosity 1 poise, dimer content 13.3
%), A low-dimer O-cresol-novolak type epoxy resin having a softening point of 55 ° C. (epoxy resin D: manufactured by Nippon Kayaku,
EOCN-4500; epoxy equivalent 200, hydrolyzable chlorine 40
0 ppm, 150 ° C. melt viscosity 1 poise, dimer content 4.5%), and as a bifunctional epoxy resin,
Epoxidized product of 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane (Epoxy resin E: manufactured by Nippon Steel Chemical Co., Ltd., ESLV-80XY; epoxy equivalent 193;
Hydrolyzable chlorine 250 ppm, melting point 78 ° C., 150 ° C. melt viscosity 0.08 poise), 2,2′-dimethyl-5,
Epoxidized product of 5'-di-tert-butyl-4,4'-dihydroxydiphenyl sulfide (Epoxy resin F: Nippon Steel Chemical Co., Ltd., ESLV-120TE; epoxy equivalent 245,
300 ppm hydrolyzable chlorine, melting point 118 ° C, 150 ° C
Melt viscosity 0.16 poise), Epoxidized 3,3 ', 5,5'-tetramethyl-4,4'-dihydroxybiphenyl (Epoxy resin G: Yuka Shell Epoxy, YX-4
000H; epoxy equivalent 190, hydrolyzable chlorine 280pp
m, melting point 105 ° C, 150 ° C melt viscosity 0.11 poise)
Was used. In addition, as the aromatic oligomer, Reference Example 1 was used.
And 2 aromatic oligomers were used.

The epoxy resin and the aromatic oligomer were mixed in the proportions (parts by weight) shown in Table 1 and melt-mixed at 150 ° C. for 30 minutes to obtain an epoxy resin composition. Table 1 shows the physical properties of the epoxy resin composition and the results of the blocking test. The results of the blocking test were obtained by using a powder of a 2-mm pass of the epoxy resin mixture, and expressing the blocking ratio after standing at 20 ° C. for 6 hours by weight%. The softening point of the resin is a value measured using glycerin as a heat medium,
The 50 ° C. melt viscosity is a value measured using Reomat 115 manufactured by Contrabass.

Examples 6 to 10 and Comparative Examples 6 to 10 Epoxy resin compositions of Examples 1 to 5 and Comparative Examples 1 to 5 as epoxy resins, and a phenol having a softening point of 80 ° C. as a curing agent.
Lunovolac (Curing agent A: Gunei Chemical, PSM-4261; OH
Novolak type brominated epoxy (brominated epoxy A: Nippon Kayaku, BR, as a flame retardant)
EN-S; epoxy equivalent 284, hydrolyzable chlorine 600 pp
m, softening point of 84 ° C.), spherical silica as a filler (silica A: average particle size, 18 μm), triphenylphosphine as a curing accelerator, and additives shown in Table 2; ) To prepare a filler-containing epoxy resin composition. This epoxy resin composition was added to 175
Molding at 175 ° C, post-curing at 175 ° C for 12 hours,
After obtaining a cured product test piece, it was subjected to various physical property measurements.

The glass transition point is determined by a thermomechanical measuring device.
The temperature was determined at a rate of 7 ° C./min. The flexural strength and flexural modulus were determined by a three-point bending method. Adhesive strength is 25mm x 12.5mm x 0.5m between 42 alloy plates
m at 175 ° C. using a compression molding machine.
After post-curing at 5 ° C. for 12 hours, the tensile shear strength was evaluated by obtaining the shear strength. Further, the water absorption is a value obtained by molding a disk having a diameter of 50 mm and a thickness of 3 mm using the epoxy resin composition, and after absorbing the moisture for 100 hours at 85 ° C. and 85% RH after post-curing, The crack occurrence rate was QFP-80 pin (14 mm x 20 mm x
2.5 mm, 194 alloy), after post-curing, after absorbing moisture for 85 hours at 85 ° C. and 85% RH for 2 hours.
After being immersed in a solder bath at 60 ° C. for 10 seconds, the state of the package was observed and determined. Table 3 summarizes the results.

The result of the blocking test was determined by using a 1 mm pass powder of the epoxy resin composition at 25.degree.
The blocking ratio after standing for a period of time was represented by% by weight. The storage stability was represented by the residual spiral flow after leaving the epoxy resin composition at 25 ° C. for one week.

[0041]

[Table 1]

[0042]

[Table 2]

[0043]

[Table 3]

[0044]

EFFECTS OF THE INVENTION The epoxy resin composition of the present invention has improved blocking resistance, excellent handling workability, and excellent low moisture absorption, high heat resistance, and high adhesion to different materials. It gives a cured product and can be suitably used as an electronic component sealing material.

 ──────────────────────────────────────────────────の Continuing on the front page (72) Katsumi Hotta Inventor, Nippon Steel Chemical Co., Ltd.

Claims (3)

[Claims] (1) An o- having a dimer content of 10% or less.
Bifunctional epoxy resin 1 having 100 parts by weight of cresol novolac epoxy resin, an epoxy equivalent of 180 to 300 and a melt viscosity at 150 ° C. of 0.05 to 0.5 poise.
An epoxy resin composition comprising 0 to 100 parts by weight and 5 to 100 parts by weight of a thermoplastic aromatic oligomer having a softening point of 70 to 150 ° C. 2. An epoxy resin composition comprising the epoxy resin composition according to claim 1, a phenolic curing agent and 75% by weight or more of an inorganic filler. 3. An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 2.