JP2022069238A - Epoxy resin composition and method for manufacturing the same - Google Patents

Abstract

To provide an epoxy resin composition having excellent flowability during molding even though a cured body has a small coefficient of linear expansion.SOLUTION: An epoxy resin composition includes epoxy resin (A) and silica (B). The silica (B) includes silica (B1) whose mean particle diameter is 0.01-0.1 μm, and silica (B2) whose mean particle diameter is 1 μm or more.SELECTED DRAWING: None

Description

The present disclosure relates to an epoxy resin composition and a method for producing an epoxy resin composition, and more particularly, an epoxy resin composition containing an epoxy resin and silica, and an epoxy resin comprising a first mixing step and a second mixing step. The present invention relates to a method for producing a composition.

As a method for encapsulating a member such as a semiconductor element or a substrate constituting an electronic component such as a semiconductor device, a method of encapsulating by a compression molding method using a sheet-shaped encapsulating material has been studied. The epoxy resin composition containing the epoxy resin used in such a method and silica as a filler is required to have a small coefficient of linear expansion of the cured product. In such an epoxy resin composition, silica having an average particle size of 1 μm or more (μ size) and silica having an average particle size of 0.1 μm or more and less than 1 μm (sub μ size) are mixed and used as silica. It is known that the volume fraction of silica in the composition can be increased, thereby reducing the coefficient of linear expansion of the cured product (see Patent Document 1 and Patent Document 2).

Japanese Patent No. 2853550 Japanese Patent No. 3038640

However, in the conventional epoxy resin composition, if the volume fraction of silica is made larger in order to make the linear expansion coefficient of the cured product smaller, the flowability at the time of molding is lowered, so that the sealing is performed satisfactorily. There is an inconvenience that it cannot be done.

An object of the present disclosure is to provide an epoxy resin composition having excellent flowability during molding even if the coefficient of linear expansion of the cured product is reduced, and a method for producing the epoxy resin composition.

The epoxy resin composition according to one aspect of the present disclosure contains an epoxy resin (A) and silica (B). The silica (B) includes silica (B1) having an average particle size of 0.01 μm or more and 0.1 μm or less, and silica (B2) having an average particle size of 1 μm or more.

The method for producing an epoxy resin composition according to one aspect of the present disclosure contains an epoxy resin (A) and silica (B), and the silica (B) has an average particle size of 0.01 μm or more and 0.1 μm. This is a method for producing an epoxy resin composition containing the following silica (B1) and silica (B2) having an average particle size of 1 μm or more. This method for producing an epoxy resin composition includes a first mixing step and a second mixing step. In the first mixing step, the epoxy resin (A) and the powdery silica (B2) are mixed using a wet pulverizer. In the second mixing step, the mixture obtained in the first mixing step and the slurry-like silica (B1) are mixed.

According to the present disclosure, it is possible to provide an epoxy resin composition having excellent flowability during molding and a method for producing the epoxy resin composition even if the coefficient of linear expansion of the cured product is reduced.

<Epoxy resin composition>
The epoxy resin composition according to the present embodiment (hereinafter, also referred to as composition (X)) contains an epoxy resin (A) and silica (B). The silica (B) includes silica (B1) having an average particle size of 0.01 μm or more and 0.1 μm or less, and silica (B2) having an average particle size of 1 μm or more.

According to this embodiment, the volume fraction of silica in the composition (X) can be made larger, whereby the coefficient of linear expansion of the cured product of the composition can be made smaller. In this way, the inventors have increased the volume fraction of silica (B) by using nano-sized silica (B1) having an average particle size in a specific range in addition to μ-sized silica (B2). It has been found that even when the linear expansion coefficient of the cured product is reduced, the flowability of the composition (X) during molding can be reduced and the composition (X) can be made excellent. According to the composition (X), at the time of molding, it is possible to fill a portion having a thin or complicated shape and which is normally difficult to flow, and good sealing can be performed.

The composition (X) may contain a curing agent, a curing accelerator, or the like in addition to the epoxy resin (A) and silica (B), or may further contain additives other than the above-mentioned components. .. If the composition (X) does not contain a curing agent, the coefficient of linear expansion of the cured product can be made smaller.

[Epoxy resin (A)]
The epoxy resin (A) is not particularly limited as long as it is a compound having two or more epoxy groups in one molecule.

Examples of the epoxy resin (A) include bisphenol type epoxy resin, hydrogenated bisphenol type epoxy resin, biphenyl type epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, phenol novolac type epoxy resin, and cresol novolac type epoxy resin. Examples thereof include triphenylmethane type epoxy resin, alicyclic epoxy resin, aliphatic epoxy resin, triglycidyl isocyanurate, glycidyl group-containing silicone resin, and glycidylamine type epoxy resin.

The viscosity of the epoxy resin (A) at 150 ° C. is preferably 10 mPa · s or less. In this case, the flowability of the composition (X) at the time of molding can be further improved. This viscosity is more preferably 9 mPa · s or less, and even more preferably 7 mPa · s or less. The lower limit of this viscosity is not particularly limited, but is, for example, 1 mPa · s. Examples of such an epoxy resin (A) include a naphthalene type epoxy resin and a dicyclopentadiene type epoxy resin.

The ratio of the epoxy resin (A) to the entire composition (X) is preferably 1% by mass or more and 25% by mass or less. In this case, the flowability at the time of molding can be further improved, and the physical properties of the cured product can be further improved. This ratio is more preferably 4% by mass or more and 20% by mass or less, and further preferably 6% by mass or more and 15% by mass or less.

(Hardener)
The curing agent is not particularly limited as long as it is a compound capable of causing a curing reaction with the epoxy resin (A).

Examples of the curing agent include phenolic curing agents, acid anhydrides, amines, imidazoles, hydrazides, polypeptides, Lewis acid-amine complexes and the like. The curing agent preferably contains a phenolic curing agent. The phenolic curing agent has better curability than other curing agents, whereby the physical properties of the cured product of the composition (X) can be further improved.

Examples of the phenol-based curing agent include novolak-type resins such as phenol novolac resin, cresol novolak resin, and naphthol novolak resin; and aralkyl such as phenol aralkyl resin having a phenylene skeleton or biphenylene skeleton, and naphthol aralkyl resin having a phenylene skeleton or biphenylene skeleton. Type resin; Polyfunctional phenol resin such as triphenol methane type resin; Dicyclopentadiene type phenol resin such as dicyclopentadiene type phenol novolac resin, dicyclopentadiene type naphthol novolac resin; Terpen modified phenol resin; Bisphenol A, Bisphenol F Bisphenol type resin such as; Triazine-modified novolak resin and the like.

The equivalent of the curing agent to one equivalent of the epoxy resin (A) is, for example, 0.6 or more and 1.4 or less.

When the composition (X) contains a curing agent, the ratio of the curing agent to 100 parts by mass of the epoxy resin (A) is preferably 40 parts by mass or more and 90 parts by mass or less, and 50 parts by mass or more and 80 parts by mass or less. It is more preferable that the amount is 60 parts by mass or more and 70 parts by mass or less.

The ratio of the curing agent to the composition (X) is preferably 1% by mass or more and 20% by mass or less, and more preferably 2% by mass or more and 10% by mass or less.

(Curing accelerator)
Examples of the curing accelerator include imidazoles such as 2-methylimidazole, 2-ethyl imidazole, 2-phenyl imidazole, and 2-ethyl-4-methyl imidazole; 1,8-diazabicyclo [5.4.0] undecene-7. , 1,5-diazabicyclo [4.3.0] nonen-5, 5,6-dibutylamino-1,8-diazabicyclo [5.4.0] undecene-7 and other cycloamidins; 2- (dimel) Tertiary amines such as aminomethyl) phenol, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol; tributylphosphine, methyldiphenylphosphine, triphenylphosphine, tris (4-) Methylphenyl) phosphine, diphenylphosphine, addition reactants of triphenylphosphine and parabenzoquinone, organic phosphines such as phenylphosphine; tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenylborate, tetrabutylphosphonium / tetrabutyl Tetra-substituted phosphonium / tetra-substituted borates such as borate; quaternary phosphonium salts with counter anions other than borate; tetraphenylborone salts such as 2-ethyl-4-methylimidazole / tetraphenylphosphine and N-methylmorpholine / tetraphenylphosphine. And so on.

The ratio of the curing accelerator to 100 parts by mass of the total of the epoxy resin (A) and the curing agent is preferably 0.01 parts by mass or more and 5 parts by mass or less, and 0.05 parts by mass or more and 2 parts by mass or less. Is more preferable.

The ratio of the curing accelerator to the composition (X) is preferably 0.001% by mass or more and 1% by mass or less, and more preferably 0.005% by mass or more and 0.2% by mass or less.

[Silica (B)]
The silica (B) includes silica (B1) having an average particle size of 0.01 μm or more and 0.1 μm or less, and silica (B2) having an average particle size of 1 μm or more.

The silica (B) preferably contains silica (B3) having an average particle size of more than 0.1 μm and less than 1 μm, in addition to silica (B1) and silica (B2). In this case, the flowability of the composition (X) can be further improved. Further, the silica (B) may contain silica other than silica (B1) to (B3).

Examples of silica (B) include crystalline silica, non-crystalline silica, amorphous silica, molten silica, and crushed silica.

Examples of the shape of the silica (B) particles include a spherical shape, a chain shape, a cocoon shape, an irregular shape, and an indefinite shape.

Silicas (B1) to (B3) can be distinguished from each other by analyzing the particle size distribution of silica (B) obtained from the measurement result by the ultrasonic attenuation method. The silica (B1) to (B3) may contain one kind or two or more kinds, respectively. The average particle size of the silica (B1) to (B3) is the median diameter (D50) obtained from the particle size distribution obtained from the measurement result by the ultrasonic attenuation method.

The volume fraction of silica (B) can be calculated as follows. When the true specific density of each of n kinds of silica (n is an integer of 2 or more) used as silica (B) is di (i is an integer between 2 and n), and the compounding mass of each silica is Wi. The true specific gravity d of the entire silica (B) is calculated by the following formula (A).
d = ΣWi / Σ (Wi / di) ・ ・ ・ (A)

The volume fraction (Φ) (%) of silica (B) is when the mass of silica (B) is W (g) (= ΣWi) and the apparent volume of the composition (X) is V (cm ³ ). , Calculated by the following formula (B).
Φ = (W / d) × 100 / V ・ ・ ・ (B)

The larger the volume fraction of silica (B), the smaller the coefficient of linear expansion of the cured product of the composition (X). The volume fraction of silica (B) is preferably 70% or more, more preferably 75% or more, further preferably 80% or more, and particularly preferably 82% or more. The upper limit of the volume fraction of silica (B) is not particularly limited, but is, for example, 90%.

(Silica (B1))
The silica (B1) is silica having an average particle size of 0.01 μm or more and 0.1 μm or less.

The average particle size of silica (B1) is preferably 0.02 μm or more and 0.08 μm or less, and more preferably 0.04 μm or more and 0.06 μm or less.

The ratio of silica (B1) in silica (B) is preferably 1% by mass or more. In this case, the flowability during molding can be further improved. The ratio of silica (B1) is more preferably 5% by mass or more, further preferably 10% by mass or more, and particularly preferably 13% by mass or more. The ratio of silica (B1) to the entire silica (B) is preferably 30% by mass or less. In this case, the flowability during molding can be further improved. The ratio of silica (B1) is more preferably 25% by mass or less, further preferably 20% by mass or less, and particularly preferably 18% by mass or less.

The mass ratio of silica (B1) to silica (B2) (silica (B1) / silica (B2)) is preferably 0.1 or more and 1.0 or less, and 0.2 or more and 0.6 or less. Is more preferable, and more preferably 0.25 or more and 0.55 or less. In this case, the flowability during molding can be further improved.

When the silica (B) contains silica (B3), the mass ratio of silica (B1) to silica (B3) (silica (B1) / silica (B3)) is preferably 0.2 or more and 10 or less. It is more preferably 0.3 or more and 6 or less, and further preferably 0.4 or more and 1 or less. In this case, the flowability during molding can be further improved.

When silica (B) contains silica (B3), the mass ratio of silica (B1) to the total of silica (B2) and silica (B3) (silica (B1) / (silica (B2) + silica (B3))). Is preferably 0.05 or more and 1 or less, more preferably 0.1 or more and 0.5 or less, and further preferably 0.15 or more and 0.3 or less. In this case, at the time of molding. The flowability can be further improved.

The ratio of silica (B1) to the composition (X) is preferably 1% by mass or more and 40% by mass or less, more preferably 4% by mass or more and 30% by mass or less, and 10% by mass or more and 20% by mass or less. The following is more preferable.

(Silica (B2))
Silica (B2) is silica having an average particle size of 1 μm or more.

The average particle size of silica (B2) is preferably 2 μm or more and 10 μm or less, and more preferably 3 μm or more and 6 μm or less.

The ratio of silica (B2) in silica (B) is preferably 10% by mass or more and 80% by mass or less, more preferably 30% by mass or more and 70% by mass or less, and 40% by mass or more and 65% by mass or less. Is more preferable.

The ratio of silica (B2) to the composition (X) is preferably 10% by mass or more and 70% by mass or less, more preferably 20% by mass or more and 65% by mass or less, and 30% by mass or more and 60% by mass or less. The following is more preferable.

(Silica (B3))
Silica (B3) is silica having an average particle size of more than 0.1 μm and less than 1 μm.

The average particle size of silica (B3) is preferably 0.2 μm or more and 0.8 μm or less, and more preferably 0.4 μm or more and 0.6 μm or less.

When the silica (B) contains silica (B3), the ratio of the silica (B3) in the silica (B) is preferably 1% by mass or more and 50% by mass or less, preferably 3% by mass or more and 40% by mass or less. More preferably, it is more preferably 20% by mass or more and 35% by mass or less.

When the silica (B) contains silica (B3), the mass ratio of silica (B3) to silica (B2) (silica (B3) / silica (B2)) is preferably 0.05 or more and 1 or less. It is more preferably 0.2 or more and 0.8 or less.

When the silica (B) contains silica (B3), the ratio of silica (B3) to the entire composition (X) is preferably 2% by mass or more and 45% by mass or less, and 10% by mass or more and 40% by mass or less. It is more preferable that it is 25% by mass or more and 35% by mass or less.

The proportion of silica (B) in the composition (X) is preferably 80% by mass or more, more preferably 84% by mass or more, further preferably 87% by mass or more, and 89% by mass or more. Is particularly preferable. The upper limit of the ratio of silica (B) is not particularly limited, but is, for example, 95% by mass.

The silica (B) may be surface-treated with a coupling agent or the like. The silica (B) can be surface-treated to improve its affinity with the epoxy resin (A). In particular, it is preferable that silica (B2) is surface-treated. Examples of the coupling agent include a silane coupling agent, a titanate coupling agent, an aluminum coupling agent, an aluminum / zirconium coupling agent, and the like. Examples of the silane coupling include glycidoxysilanes such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; N. Aminosilanes such as -β (aminoethyl) -γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane; alkylsilanes; ureidosilanes; vinylsilanes and the like can be mentioned. The ratio of the coupling agent to 100 parts by mass of the total amount of silica (B) is, for example, 0.01 parts by mass or more and 5 parts by mass or less, and preferably 0.5 parts by mass or more and 3 parts by mass or less.

It is preferable that the silica (B) is not aggregated. Since the silica (B) is not aggregated, the composition (X) can suppress a decrease in heat resistance due to a decrease in the glass transition point of the cured product, and a decrease in bending strength and shear strength.

In order to prevent the silica (B) from agglomerating in the composition (X), for example, when the composition (X) is produced, first, the epoxy resin (A) and the powder of the silica (B2) are mixed. Is mixed using a wet pulverizer, and then a slurry of silica (B1) is added to the obtained mixture and further mixed. When mixing using this wet pulverizer, it is preferable to use the epoxy resin (A) dissolved in an organic solvent such as methyl ethyl ketone (MEK). As the wet crusher, it is preferable to use a bead mill or the like. This makes it possible to further suppress the aggregation of silica (B). That is, the composition (X) is preferably a mixture of a wet pulverized product of powders of the epoxy resin (A) and silica (B2) and a slurry of silica (B1), and is an epoxy dissolved in an organic solvent. More preferably, it is a mixture of a wet pulverized product of the powder of the resin (A) and the silica (B2) by a bead mill and a slurry of the silica (B1).

(Additive)
The composition (X) may contain additives other than the above-mentioned components as long as the effects of the present embodiment are not impaired. Additives include, for example, elastomers, repelling inhibitors, leveling agents, mold release agents, flame retardants, flame retardants, ion trapping agents, pigments such as carbon black, colorants, tackifiers, silicone flexible agents and the like. Can be mentioned.

When the composition (X) contains an elastomer, the elastic modulus of the cured product can be reduced so that excessive stress is not applied, and the low warpage property can be further improved. Examples of the elastomer include silicone-based elastomers; (meth) acrylic elastomers such as methyl acrylate-butadiene-styrene copolymer, methyl methacrylate-butadiene-styrene copolymer, and acrylic acid ester-methyl methacrylate copolymer. Can be mentioned. The ratio of the elastomer to the composition (X) is, for example, 1% by mass or more and 30% by mass or less.

When the composition (X) contains an anti-repellent agent, for example, when it is formed into a sheet, the repellent can be suppressed. Examples of the repelling inhibitor include polyether-modified silicones, silicone-based surfactants such as polyethylene glycol-3 dimethicone, fluorine-based activators containing perfluorobutane sulfonic acid groups, and fluorine-based activators containing lipophilic groups. Fluorosurfactants and the like can be mentioned. The ratio of the repellent inhibitor to the composition (X) is, for example, 0.01% by mass or more and 1% by mass or less.

Examples of the leveling agent include fluorine-based leveling agents such as perfluoroalkane, perfluoroalkylcarboxylic acid, and perfluoroalkylethylene oxide adduct; polyether-modified polydimethylsiloxane, polyether ester-modified polydimethylsiloxane, and hydroxyl group-containing polyether. Silicone-based leveling such as modified polydimethylsiloxane, acrylic group-containing polyether-modified polydimethylsiloxane, acrylic group-containing polyester-modified polydimethylsiloxane, perfluoropolyether-modified polydimethylsiloxane, perfluoropolyester-modified polydimethylsiloxane, and silicone-modified acrylic compound. Agents: Acrylic leveling agents and the like. The ratio of the leveling agent to the composition (X) is, for example, 0.01% by mass or more and 1% by mass or less.

Examples of the mold release agent include carnauba wax, stearic acid, montanic acid, carboxyl group-containing polyolefin, ester wax, polyethylene oxide, and metal soap. The ratio of the release agent to the composition (X) is, for example, 0.01% by mass or more and 1% by mass or less.

Examples of the flame retardant include magnesium hydroxide, aluminum hydroxide, red phosphorus and the like.

Examples of the colorant include carbon black, red iron oxide, titanium oxide, phthalocyanine, perylene black and the like.

<Characteristics>
The composition (X) is preferably solid at 25 ° C. In this case, a sealing material can be produced by molding the composition (X) by a pressure molding method such as an injection molding method, a transfer molding method, or a compression molding method. In particular, after the composition (X) is formed into a sheet, a sealing material can be produced by a compression molding method. It is more preferable that the composition (X) is solid at any temperature within the range of 15 ° C. or higher and 25 ° C. or lower, and further preferably solid at any temperature within the range of 5 ° C. or higher and 35 ° C. or lower.

The composition (X) can reduce the coefficient of linear expansion of the cured product. The coefficient of linear expansion of the cured product in the range of 50 ° C. to 100 ° C. is preferably 27 ppm / ° C. or lower, more preferably 20 ppm / ° C. or lower, further preferably 17 ppm / ° C. or lower, and further preferably 15 ppm / ° C. It is particularly preferable that the temperature is below ° C. The lower limit of the linear expansion coefficient of the cured product is not particularly limited, but is, for example, 10 ppm / ° C.

The composition (X) is excellent in flowability during molding. The flowability during molding can be evaluated by the method described in the column of Examples described later.

The composition (X) can reduce the coefficient of linear expansion of the cured product and has excellent flowability during molding. Therefore, for example, after forming a sheet, it is possible to prepare a sealing material by compression molding or the like. It can be suitably used.

<Manufacturing method of composition>
The composition (X) can be produced, for example, by mixing the constituents of the composition (X).

The composition (X) is preferably produced by a production method including the first mixing step and the second mixing step shown below. By performing the first mixing step and the second mixing step, the aggregation of silica (B) in the composition (X) can be suppressed, whereby the cured product has excellent heat resistance, bending strength, and shearing. A composition having excellent strength can be obtained.
First mixing step: The epoxy resin (A) and the powdery silica (B2) are mixed using a wet pulverizer.
Second mixing step: The mixture obtained in the first mixing step and the slurry-like silica (B1) are mixed.

[First mixing step]
In this step, the epoxy resin (A) and the powdery silica (B2) are mixed using a wet pulverizer. By the first mixing step, the dispersibility of silica (B2) can be further enhanced.

In the first mixing step, in addition to the epoxy resin (A) and silica (B2), a normal curing agent, a curing accelerator, and additives such as a coupling agent, a repelling inhibitor, and a leveling agent are mixed together. As the epoxy resin (A), it is preferable to use one dissolved in an organic solvent. In the first mixing step, the slurry-like silica (B3) may be mixed together. The dispersion medium in the slurry-like silica (B3) is usually an organic solvent. The organic solvent preferably contains a ketone such as methyl ethyl ketone (MEK). By using such an organic solvent, the aggregation of silica (B2) in the mixture can be further suppressed.

Examples of the wet crusher used in the first mixing step include a bead mill, a ball mill, a vibration mill, and an attritor. Among these, it is preferable to use a bead mill. By using the bead mill, the aggregation of silica (B) in the produced composition (X) can be further suppressed.

[Second mixing step]
In this step, the mixture obtained in the first mixing step and the slurry-like silica (B1) are mixed. By the second mixing step, the aggregation of silica (B) in the produced composition (X) can be further suppressed. In the second mixing step, the slurry-like silica (B3) may be mixed together.

The dispersion medium in the silica (B1) slurry is usually an organic solvent. This organic solvent preferably contains a ketone such as MEK. By using such an organic solvent, the aggregation of silica (B) in the produced composition (X) can be further suppressed.

The mixing method for performing the second mixing step is not particularly limited, and a known mixing method using a mixer or the like can be used, but a wet pulverizer such as a bead mill may be used for mixing.

The method for producing the composition of the present embodiment may include a step of removing the organic solvent from the mixture obtained by the second mixing step after the second mixing step. Examples of the method for removing the organic solvent include a method of drying by reducing pressure or heating.

Hereinafter, the present disclosure will be described in more detail by way of examples, but the present disclosure is not limited to these examples.

1. 1. Production of Composition A composition was produced using the raw materials shown in Table 1. The manufacturing method A or the manufacturing method B shown in Table 1 indicate that the manufacturing was performed as follows.
Production Method A: First, the MEK solution of the epoxy resin (A), the powder of silica (B2), and other components other than silica (B3) were mixed and mixed using a bead mill. Next, the MEK slurry of silica (B1) and the MEK slurry of silica (B3) were added to the obtained mixture, and the mixture was mixed with a planetary mixer to obtain a composition.
Production method B: A planetary mixer containing a MEK solution of an epoxy resin (A), a MEK slurry of silica (B1), a powder of silica (B2), a MEK slurry of silica (B3), and other components. The mixture was mixed with the above to obtain a composition.

The details of the raw materials used are as follows.
-Epoxy resin (A)
-HP-7200L: Dicyclopentadiene type. "EPICLON" manufactured by DIC. Viscosity (150 ° C, ICI measurement): 7 mPa · s.
-HP-4770: Naphthalene type. "EPICLON" manufactured by DIC. Viscosity (150 ° C, ICI measurement): 9 mPa · s.
-NC-3000-L: Biphenyl type. Made by Nippon Kayaku Co., Ltd. Viscosity (150 ° C, ICI measurement): 20 mPa · s.
-Curing agent-MEH-8000H: Phenolic curing agent. Made by Meiwa Kaseisha.
-Curing accelerator 2E4MZ: Made by Shikoku Chemicals Corporation. Imidazole-based curing accelerator. 2-Ethyl-4-methylimidazole.
-Silica (B)
-Silica (B2): Spherical μ size. FB-5SDX. Made by Denka. D50: 4.2 μm. In powder form.
-Silica (B3): Spherical sub μ size. SC-2050MB. Made by Admatex. D50: 0.5 μm. MEK slurry (slurry concentration: 70% by mass).
-Silica (B1) :: Spherical nano size. Y50SZ-AM1. Made by Admatex. D50: 0.05 μm. MEK slurry (slurry concentration: 50% by mass).
-Coupling agent-KBM573: Silane coupling agent. Made by Shin-Etsu Chemical Co., Ltd. Phenylaminosilane.

2. 2. Evaluation (1) Flowability during molding When a B-stage product in the form of a sheet with a thickness of 0.1 mm and 60 mmΦ is sandwiched between a release film and the like and cured under the conditions of 135 ° C. for 10 minutes and an actual pressure of 2.0 MPa. The amount of resin flow was measured by area.
A: The flow amount was 30% or more.
B: The flow amount was 5% or more and less than 30%.
C: The flow rate was less than 5%.

(2) Coefficient of linear expansion Using the composition, a test piece having a cross section of 3 mm square and a length of 15 mm was prepared by vacuum press molding. This test piece was heated at 5 ° C. per minute using a thermomechanical analyzer (“TMA7100C” manufactured by SII Nanotechnology) to obtain a coefficient of linear expansion (ppm / ° C.) from 50 ° C. to 100 ° C. It was measured.

(3) Silica aggregation Observed with an optical microscope and evaluated according to the following criteria.
A: No aggregation of silica was observed.
B: Agglomeration of silica was observed.

Claims (6)

Contains epoxy resin (A) and silica (B),
An epoxy resin composition in which the silica (B) contains silica (B1) having an average particle size of 0.01 μm or more and 0.1 μm or less and silica (B2) having an average particle size of 1 μm or more. The epoxy resin composition according to claim 1, wherein the volume fraction of silica (B) is 80% or more. The epoxy resin composition according to claim 1 or 2, wherein the ratio of the silica (B1) in the silica (B) is 5% by mass or more and 30% by mass or less. The epoxy resin composition according to any one of claims 1 to 3, wherein the epoxy resin (A) has a viscosity at 150 ° C. of 10 mPa · s or less. A method for producing an epoxy resin composition.
The epoxy resin composition contains an epoxy resin (A) and silica (B), and the silica (B) contains silica (B1) having an average particle size of 0.01 μm or more and 0.1 μm or less. Containing silica (B2) having an average particle size of 1 μm or more,
The first mixing step of mixing the epoxy resin (A) and the powdery silica (B2) using a wet pulverizer.
A method for producing an epoxy resin composition, comprising a second mixing step of mixing the mixture obtained in the first mixing step with the slurry-like silica (B1). The method for producing an epoxy resin composition according to claim 5, wherein a bead mill is used as the wet pulverizer in the first mixing step.