JP3043838B2 - Silicone block copolymer and epoxy resin composition for molding - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel silicone block copolymer, a method for producing the same, an epoxy resin composition for molding containing the copolymer, and an electronic component using the composition as a sealing material. .

[0002]

2. Description of the Related Art Epoxy resins have excellent electrical properties, mechanical properties, chemical resistance, heat resistance, cold resistance, moisture resistance, dimensional stability, etc., and are suitable for compression molding, transfer molding, injection molding, casting, etc. Since it is easily molded by various molding methods,
It is widely used for semiconductor encapsulants, electric laminates, capacitors, resistors, potentiometers, transformers and the like.

[0003] However, since the epoxy resin has a low mold release property from the mold and low productivity, it is necessary to apply a mold release agent to the mold or mix the mold release agent with the epoxy resin composition. Dimethyl silicone oil, carnauba wax, montan wax, higher fatty acids or metal salts thereof, etc. are used as release agents, but dimethyl silicone oil has a company name, product name, lot number, date of manufacture on the surface of molded products. And the like, the printability is deteriorated when displaying such as with paints, inks, etc., the wax type has poor release and printability, and the higher fatty acid (salt) has poor adhesiveness. Was.

Further, since the epoxy resin has an advanced and rigid network structure, stress is likely to be generated due to molding distortion or rapid temperature change, and the surface of the semiconductor element may be broken, the lead wire may be slid, Rubber and silicone oil etc. are compounded because cracks may enter the sealing material itself and moisture may enter from the outside air, but rubber is inferior in heat resistance, dispersibility and mold release, silicone oil is dispersed Because of poor heat resistance and heat resistance, improvement is also desired in this regard.
In contrast, JP-A-60-13841 discloses an epoxy group reactive with an epoxy resin at both ends of a silicone molecule.
It is possible to use an organopolysiloxane in which an amino group, a hydroxyl group, a carboxy group, a carboxylic ester group, etc. are bonded, and a polyalkylene oxide is bonded to a part of the linear dimethylsiloxane unit of the silicone molecule in a pendant manner. Proposed. This has a much better effect than using conventional dimethylpolysiloxane, but leaves unreacted polyalkylene oxide, which is heat resistant, adhesive, moisture resistant, and metal corrosion resistant. However, the problem of improving the properties of the epoxy resin molding material described above has not been solved by deteriorating the stress relaxation property and the like and the properties derived from the entire chemical structure.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention has been made to solve the above problems. More specifically, the present invention, when incorporated into a molding epoxy resin composition, improves moldability, provides excellent mold releasability without causing mold fouling during molding, and seals electronic components. It shows excellent adhesion to metal, and does not cause corrosion when it comes into contact with metals that make up electronic components. A novel silicone block copolymer that does not generate internal stress and further imparts excellent moisture resistance to a molded product, a method for producing the same,
It is an object of the present invention to provide a molding epoxy resin composition containing the copolymer and an electronic component using the composition as a sealing material.

[0006]

The present inventors have synthesized organopolysiloxanes having various chemical structures and studied molded articles obtained from the molding epoxy resin compositions containing the same. The present inventors have found that the silicone-based block copolymer gives excellent results, and completed the present invention.

That is, the present invention provides the following formula D:

Embedded image (In the formula, a, b and c each represent an integer of at least 2, n represents an integer of 2 to 4, R ′ represents a hydrogen atom or a monovalent hydrocarbon group, and R ″ represents a monovalent hydrocarbon. Represents a hydrogen group, R ″ ′ represents a residue in which an ethylenically unsaturated group-containing monomer is saturated with a hydrogen atom, X is an epoxy group,
(Representing an amino group, a hydroxyl group, a carboxy group or a methacryl group). Thus, the silicone-based block copolymer of the present invention has an epoxy group, an amino group, a hydroxyl group, a carboxy group or a methacryl group at both terminals, and has a linear polysiloxane-polyoxyalkylene block as a repeating unit. It is non-hydrolyzable in molecular weight.

The silicone block copolymer represented by the above formula D of the present invention is represented by the following formula A: HR ″ ₂ SiO (R ″ ₂ SiO) _a SiR ″ ₂ H (A) (where R ″ is Represents a monovalent hydrocarbon group, and a represents an integer of at least 2) and a compound represented by the following formula B:

Embedded image (Wherein, R ′ represents a hydrogen atom or a monovalent hydrocarbon group, b represents an integer of at least 2, and n represents an integer of 2 to 4). The compound represented by the following formula C is reacted in excess with the compound represented by the formula B to obtain a compound represented by the following formula C:

Embedded image (Wherein R ′, R ″, a, b and n have the same meanings as above, and c represents an integer of at least 2). The copolymer can be produced by producing a block copolymer having the same, and reacting the copolymer with an ethylenically unsaturated group-containing monomer having an epoxy group, an amino group, a hydroxyl group, a carboxy group or a methacryl group. The present invention also relates to the above manufacturing method.

In the above formula, R 'and R "as the monovalent hydrocarbon group are, for example, an alkyl group (for example, a methyl group,
Ethyl group, propyl group, isopropyl group, butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, octadecyl group, eicosyl group, etc., aryl group (for example, phenyl group, naphthyl group, etc.), aralkyl group ( Benzyl group, phenylethyl group, etc.), tolyl group, xylyl group, cyclohexyl group and the like.

The polyoxyalkylene group represented _by- (C _n H _2n O) _b- in the above formula B is derived from polyoxyethylene, polyoxypropylene, polyoxybutylene, mixed polyoxyethylene-oxypropylene and the like. You.

The reaction between the compound represented by the above formula A and the compound represented by the above B is carried out in an organic solvent (benzene, toluene, xylene, pentane, heptane, octane, o-dichlorobenzene, monochlorobenzene, diethylcarbitol). , Dibutyl carbitol, diethoxytetraglycol, etc.), platinum-based catalysts (chloroplatinic acid, reactants of chloroplatinic acid and alcohol, complexes of platinum with olefins, complexes of platinum with ketones, platinum Complexes with vinylsiloxane, complexes of platinum and triphenyl osphite, etc., palladium catalysts (tetrakis (triphenylphosphine) palladium, mixtures of palladium black and triphenylphosphine, etc.), rhodium catalysts (rhodium and phosphine compounds) And a catalyst for promoting hydrosilylation, such as a complex with Is carried out using 0.01 to 50 ppm with respect to the total amount of the compound, so that a polysiloxane unit and a polyoxyalkylene unit each having a hydrosilyl group (HSi に) at both terminals are represented by the formula C A block copolymer is obtained.

Next, a monomer containing an ethylenically unsaturated group having an epoxy group, an amino group, a hydroxyl group, a carboxy group or a methacryl group is added to the hydrosilyl groups at both ends of the block copolymer represented by the formula C. When reacted, a silicone-based copolymer D having a functional group at both ends and having polysiloxane units and polyoxyalkylene units alternately obtained is obtained.

Examples of the ethylenically unsaturated group-containing monomer used in the present invention include the following: an ethylenically unsaturated compound having an epoxy group: glycidyl methacrylate, 2-methylglycidyl methacrylate, glycidylcinna A compound in which one of two glycidyl groups of a mate, epoxystearyl (meth) acrylate, or bisphenol A or bisphenol F epoxy is (meth) acrylated. An ethylenically unsaturated compound having an amino group, acrylamide, methacrylamide, or allylamine; Ethylenically unsaturated compound having a hydroxyl group 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, trimethylolpropane (meth) ) Acrylate, pentaerythritol (meth) acrylate, 2-hydroxyethylcinnamate. Ethylenically unsaturated compounds having a carboxy group or a methacrylic group Acrylic acid, glycidyl acrylate, allyl acrylate, 2-cyanoethyl acrylate, isobutyl acrylate, n-butyl acrylate, ethyl acrylate, methacrylic acid, allyl methacrylate , Isobutyl methacrylate, ethyl methacrylate, n-butyl methacrylate.

The present invention further relates to a molding epoxy resin composition comprising 100 parts by weight of an epoxy resin and 0.005 to 20 parts by weight of a silicone block copolymer represented by the above formula D.

If the amount of the silicone-based block copolymer represented by the formula D is less than 0.005 parts by weight based on 100 parts by weight of the epoxy resin, the effect of the copolymer is not exhibited. Undesirably, the mechanical properties, heat resistance, dimensional stability, etc. of the epoxy resin are impaired.

In the present invention, the epoxy resin means a commonly used polyvalent epoxy resin, and examples thereof include the following: glycidyl compounds such as phenol novolak and cresol novolak; bisphenol A, bishydroxydiphenylmethane, resorcinol , Bishydroxydiphenyl ether, tetrabromobisphenol A
Epoxy resins of polyhydric phenols such as ethylene glycol, neopentyl glycol, glycerin, tantamethylol propane, pentaerythritol, diethylene glycol, polypropylene glycol, bisphenol A-ethylene oxide adducts, trishydroxyethylene isocyanurate and other polyhydric alcohols Diglycidyl ether type epoxy resin; glycidylamine type epoxy resin of polyamino compound such as ethylenediamine, aniline; glycidyl ester type epoxy resin of polyvalent carboxy compound such as adipic acid, phthalic acid, isophthalic acid; dicyclopentadiene epoxide, butadiene die Fatty acid (including alicyclic) epoxy resin such as merged epoxide.

Further, the epoxy resin composition for molding according to the present invention includes fumed silica, fused silica, crystalline silica,
Calcium carbonate, kaolin, talc, alumina, aluminum hydroxide, magnesium oxide, magnesium hydroxide, dolomite, zircon, diatomaceous earth, mica, asbestos, titanium oxide, glass fiber, antimony oxide, halogen compounds, phosphorus compounds, silane coupling agents, Titanium coupling agent, aluminum coupling agent, pigment,
An antioxidant, an antioxidant and the like may be added.

The molding epoxy resin composition of the present invention can be cured with a conventional curing agent such as aliphatic amines, aromatic amines, acid anhydrides, imidazoles, hydrazides, dicyandiamides and the like.

Further, the molding epoxy resin composition of the present invention is obtained by uniformly stirring and mixing the components, kneading them with a kneader, a roll, an extruder, etc., and then pulverizing by cooling pulverization, sheet cutting, a pelletizer or the like. This is supplied to a compression molding machine, a transfer molding machine, and an injection molding machine.
Used as a sealing material for C, LSI, transistors, thyristors, diodes, etc., as a material for electrical laminates, capacitors, resistors, potentiometers, transformers, powder coatings, electrical insulating coatings, corrosion-resistant coatings, It can be used as a mold material, impregnating material, heat-resistant varnish, coating material, and other general molding materials. Above all, the molding epoxy resin composition of the present invention is excellent as a sealing material for electronic components. Therefore, the present invention also relates to an electronic component using the molding epoxy resin composition as a sealing material.

[0020]

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples, and those embodying the technical idea of the present invention are within the scope of the present invention. Contained within. Note that M in the chemical formula shown in this example
e represents a methyl group. Production of Silicone Block Copolymer Synthesis Example 1 Dimethallylpolyether [CH ₂ ＣC (CH ₃ ) CH
₂ O (C ₂ H ₄ O) ₁₈ (C ₃ H ₆ O) ₃₃ CH ₂ C (CH
₃₎ = CH _2] 100 g, toluene 350 g, a platinum 20ppm in the form of chloroplatinic acid, a mechanical stirrer, condenser, 3 a 500ml equipped with a thermometer and nitrogen inlet
And the mixture was heated to a temperature of 80 to 10
Dihydropolydimethylsiloxane [HMe ₂ SiO (SiMe ₂ O) ₄₀ SiMe ₂ at a rate such that it is maintained at 0 ° C.
H] was slowly added. The end of the reaction was determined by taking out a part of the contents of the flask at regular intervals, measuring the viscosity, and stopping the increase in viscosity. Then, the reaction mixture was neutralized with NaHCO ₃ , filtered, and the solvent was removed by a rotary evaporator at 50 ° C./1 mmHg.

Embedded image 220 g of an alternating block copolymer having a molecular weight of 50,200 and was obtained.

Next, 100 g of the above alternating block copolymer and 350 g of toluene were placed in the same three-necked flask as above.
And 20 ppm of platinum in the form of chloroplatinic acid. 0.6 g of glycidyl methacrylate was slowly added to the mixture at such a rate as to maintain the temperature at 80-100 ° C. The termination of this reaction was determined by the fact that the AgNO ₃ reagent with respect to SiH became negative. The reaction mixture is then
After neutralization with HCO ₃ , filtration and removal of the solvent at 50 ° C./1 mmHg with a rotary evaporator, the following formula:

Embedded image Having a glycidyl group at both terminals represented by the following formula:
Thus, 100 g of the alternating block copolymer No. 00 was obtained.

Synthesis Example 2 Dimethallyl polyether [CH ₂ ＣC (CH ₃ ) CH
₂ O (C ₂ H ₄ O) ₂₀ (C ₃ H ₆ O) ₂₉ CH ₂ C (CH
₃ ) = CH ₂ ] 70 g, dihydropolydimethylsiloxane [HMe ₂ SiO (SiMe ₂ O) ₃₀ SiMe ₂ H]
Using 61 g, 350 g of toluene and 20 ppm of platinum as a platinum-based addition catalyst, the same operation as in Synthesis Example 1 was performed, and the following formula:

Embedded image 126 g of a copolymer having a molecular weight of 37000 represented by the formula was obtained.

Next, 100 g of the above-mentioned alternating block copolymer and 350 g of toluene were placed in a 500 ml three-necked flask equipped with a mechanical stirrer, a condenser, a thermometer and a nitrogen inlet.
g and 20 ppm of platinum in the form of chloroplatinic acid. To this mixture was slowly added 0.5 g of acrylic acid at such a rate as to maintain the temperature at 80-100 ° C. The termination of this reaction was determined by the fact that the AgNO ₃ reagent with respect to SiH became negative. The reaction mixture was then neutralized with NaHCO ₃ , filtered and 50 ° C. on a rotary evaporator.
After removing the solvent at / 1 mmHg, the following formula:

Embedded image Having a carboxyl group at both ends represented by
100 g of 150 alternating block copolymers were obtained.

Synthesis Example 3 Dimethallyl polyether [CH ₂ ＣC (CH ₃ ) CH
₂ O (C ₂ H ₄ O) ₁₈ (C ₃ H ₆ O) ₂₀ CH ₂ C (CH
₃ ) = CH ₂ ] 120 g, dihydropolydimethylsiloxane [HMe ₂ SiO (SiMe ₂ O) ₁₅ SiMe
₂ H], the same operation as in Synthesis Example 1 was performed using 80 g of toluene, 330 g of toluene, and 20 ppm of platinum as a platinum-based addition catalyst.

Embedded image 184 g of a copolymer represented by the following formula and having a molecular weight of 37000 was obtained.

Next, 100 g of the above alternating block copolymer and 350 g of toluene were placed in a 500 ml three-necked flask equipped with a mechanical stirrer, a condenser, a thermometer and a nitrogen inlet.
g and 20 ppm of platinum in the form of chloroplatinic acid. 0.8 g of hydroxypropyl methacrylate was slowly added to the mixture at such a rate as to maintain the temperature at 80-100 ° C. The end of this reaction is based on Ag relative to SiH.
It was determined that the NO ₃ reagent became negative. Then, the reaction mixture was neutralized with NaHCO ₃ , filtered, and the solvent was removed by a rotary evaporator at 50 ° C./1 mmHg.

Embedded image 100 g of an alternating block copolymer having a hydroxypropyl group at both terminals and having a molecular weight of 37,400 was obtained.

Example 1 Orthocresol novolak type epoxy resin (Nippon Kayaku, EOCN-1020-70) 80 parts by weight, brominated epoxy resin (Toto Kasei, YDB-340) 15 parts by weight, fused silica powder 300 parts by weight Part, curing agent (phenol novolak resin, manufactured by Dainippon Ink, TD-2093) 2
5 parts by weight, 1.3 parts by weight of a curing accelerator (2-methyl-4-imidazole), 1.5 parts by weight of carbon black, 15 parts by weight of antimony trioxide, γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar) , A-187)
1.3 parts by weight and 3 parts by weight of the alternating block copolymer of Synthesis Example 1 were mixed, kneaded with a hot roll at 85 to 95 ° C. for 30 minutes, left at room temperature for 5 hours, and then pulverized to seal a semiconductor. A composition was obtained. The composition was supplied to a transfer molding machine, and the semiconductor was sealed. At this time, the mold temperature was 175 ° C., the curing time was 1 minute, and the post-curing time was 8 hours. Evaluation: Mold stainability: The number of molding shots until mold fogging occurred was 2010, which was very good. -Mold releasability: 1.5 g of the composition was compression-molded at 175 ° C for 2 minutes in a mold having a cylindrical cavity with a cross-sectional area of 1 cm ² , and a mold-extruding force (kg) immediately after molding. )
Was measured with a push-pull gauge, and 1.8 to 2.
5 kg, which was good. -Adhesion to metal: After immersion in a red check solution and boiling for 10 hours, permeation of the red check solution to the interface between the resin and the lead frame was observed, but no permeation was observed. -Marking property: After printing on the surface of the molded product with MARKEM 7224, it was sufficiently heated and cured, and a cellophane tape was adhered on it and peeled off rapidly, but it was not transferred to the tape side at all and showed good marking property. Was.・ Corrosion resistance: Leave the molded product in a pressure cooker,
When the disconnection rate (%) of the aluminum wiring after 000 hours was measured, it was 0. Therefore, the corrosion resistance was good. Moisture resistance: 100 molded articles were subjected to a moisture resistance test under high pressure steam at 120 ° C. for 1000 hours, and the number of defective products was observed. The result was 0, indicating good moisture resistance. -Low stress property: When the flexural modulus (JIS K6911) was measured, it was 1120 kg / mm ² , and was excellent in low stress property.

Example 2 Orthocresol novolak type epoxy resin (Nippon Kayaku, EOCN-1020-70) 80 parts by weight, brominated epoxy resin (Toto Kasei, YDB-340) 15 parts by weight, fused silica powder 300 parts by weight Part, curing agent (phenol novolak resin, manufactured by Dainippon Ink, TD-2093) 2
5 parts by weight, 1.3 parts by weight of a curing accelerator (2-methyl-4-imidazole), 1.5 parts by weight of carbon black, 15 parts by weight of antimony trioxide, γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar) , A-187)
1.3 parts by weight and 1 part by weight of the alternating block copolymer of Synthesis Example 2 were mixed, kneaded with a hot roll at 85 to 95 ° C. for 30 minutes, left at room temperature for 5 hours, and then pulverized to seal a semiconductor. A composition was obtained. The composition was supplied to a transfer molding machine, and the semiconductor was sealed. At this time, the mold temperature was 175 ° C., the curing time was 1 minute, and the post-curing time was 8 hours. Evaluation: Mold stainability: The number of molding shots before mold fogging was 1920, which was very good. -Mold releasability: 1.5 g of the composition was compression-molded at 175 ° C for 2 minutes in a mold having a cylindrical cavity with a cross-sectional area of 1 cm ² , and a mold-extruding force (kg) immediately after molding. )
Was measured with a push-pull gauge, and 2.3 to 3.
0 kg, which was good. -Adhesion to metal: After immersion in a red check solution and boiling for 10 hours, permeation of the red check solution to the interface between the resin and the lead frame was observed, but no permeation was observed.・ Sealability: After printing on the surface of the molded product with MARKEM 7224, it was sufficiently heated and cured, and a cellophane tape was adhered thereon and rapidly peeled off, but the transfer rate to the tape side was 1%. The sealability was shown.・ Corrosion resistance: Leave the molded product in a pressure cooker,
When the disconnection rate (%) of the aluminum wiring after 000 hours was measured, it was 2. Therefore, the corrosion resistance was good. -Moisture resistance: A 100-piece molded product was subjected to a 1000-hour moisture resistance test under high-pressure steam at 120 ° C, and the number of defective products was observed. As a result, it was 2, indicating good moisture resistance. -Low stress property: When the flexural modulus (JIS K6911) was measured, it was 1280 kg / mm ² , and was excellent in low stress property.

Example 3 Orthocresol novolac type epoxy resin (Nippon Kayaku, EOCN-1020-70) 80 parts by weight, brominated epoxy resin (Toto Kasei, YDB-340) 15 parts by weight, fused silica powder 300 parts by weight Part, curing agent (phenol novolak resin, manufactured by Dainippon Ink, TD-2093) 2
5 parts by weight, 1.3 parts by weight of a curing accelerator (2-methyl-4-imidazole), 1.5 parts by weight of carbon black, 15 parts by weight of antimony trioxide, γ-glycidoxypropyltrimethoxysilane (manufactured by Nippon Unicar) , A-187)
1.3 parts by weight and 15 parts by weight of the alternating block copolymer of Synthesis Example 2 were mixed, kneaded with a hot roll at 85 to 95 ° C. for 30 minutes, left at room temperature for 5 hours, and then pulverized to seal semiconductors. A composition was obtained. The composition was supplied to a transfer molding machine, and the semiconductor was sealed. At this time, the mold temperature was 175 ° C., the curing time was 1 minute, and the post-curing time was 8 hours. Evaluation: Mold stainability: The number of molding shots before mold fogging was 2250, which was very good. -Mold releasability: 1.5 g of the composition was compression-molded at 175 ° C for 2 minutes in a mold having a cylindrical cavity with a cross-sectional area of 1 cm ² , and a mold-extruding force (kg) immediately after molding. )
Was measured with a push-pull gauge to find that 1.5 to 2.
3 kg, which was good. -Adhesion to metal: After immersion in a red check solution and boiling for 10 hours, permeation of the red check solution to the interface between the resin and the lead frame was observed, but no permeation was observed.・ Sealability: After printing on the surface of the molded product with MARKEM 7224, it was sufficiently heated and cured, and a cellophane tape was adhered thereon and rapidly peeled off, but the transfer rate to the tape side was 3%. The sealability was shown.・ Corrosion resistance: Leave the molded product in a pressure cooker,
When the disconnection rate (%) of the aluminum wiring after 000 hours was measured, it was 0. Therefore, the corrosion resistance was good. -Moisture resistance: A 100-piece molded product was subjected to a moisture resistance test under high-pressure steam at 120 ° C for 1000 hours, and the number of defective products was observed. As a result, it was 3, indicating good moisture resistance. -Low stress property: When the flexural modulus (JIS K6911) was measured, it was 1010 kg / mm ² , and was excellent in low stress property.

[0029]

As explained in detail above, the silicone block copolymer of the present invention has a functional group at both ends and has been proposed as an alternating block type of polysiloxane and polyoxyalkylene. It is a copolymer without any problems. The epoxy resin composition for molding containing this silicone block copolymer has good moldability, mold fouling, mold release, adhesion to metal, corrosion resistance, stamping, moisture resistance, and low stress. And so on, satisfying the demands for epoxy resins. Accordingly, the molding epoxy resin composition of the present invention can be used as a sealing material for electronic components such as ICs, LSIs, transistors, thyristors, and diodes as electric laminates, capacitors, resistors, potentiometers, and the like.
Used as a material for transformers and as powder coating, electrical insulating coating, corrosion-resistant coating, casting material, impregnating material, heat-resistant varnish, coating material, and other general molding materials, etc., giving molded products of excellent quality It is.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI H01L 23/29 H01L 23/30 R 23/31 (58) Investigated field (Int.Cl. ⁷ , DB name) C08G 77/46 C08L 63/00 C08L 83/12

Claims (4)

(57) [Claims] 1. The following formula D: (In the formula, a, b and c each represent an integer of at least 2, n represents an integer of 2 to 4, R ′ represents a hydrogen atom or a monovalent hydrocarbon group, and R ″ represents a monovalent hydrocarbon. Represents a hydrogen group, R ″ ′ represents a residue in which an ethylenically unsaturated group-containing monomer is saturated with a hydrogen atom, X is an epoxy group,
Amino group, hydroxyl group, carboxy group or methacryl group). 2. The following formula A: HR ″ ₂ SiO (R ″ ₂ SiO) _a SiR ″ ₂ H (A) (wherein, R ″ represents a monovalent hydrocarbon group, and a is an integer of at least 2) And a compound represented by the following formula B: (Wherein, R ′ represents a hydrogen atom or a monovalent hydrocarbon group, b represents an integer of at least 2, and n represents an integer of 2 to 4). The compound represented by the formula (B) is reacted in excess with the compound represented by the formula (B) to give the following compound (C): (Wherein R ′, R ″, a, b and n have the same meanings as above, and c represents an integer of at least 2). To produce a block copolymer having an ethylenically unsaturated group having an epoxy group, an amino group, a hydroxyl group, a carboxy group or a methacryl group, and reacting the copolymer with a monomer having the following formula D: ] (Wherein, R ′, R ″, a, b, c and n have the same meanings as described above, and R ″ ″ represents a residue in which an ethylenically unsaturated group-containing monomer is saturated with a hydrogen atom. , X represents an epoxy group, an amino group, a hydroxyl group, a carboxy group or a methacryl group). 3. A molding epoxy resin composition comprising 100 parts by weight of an epoxy resin and 0.005 to 20 parts by weight of the silicone-based block copolymer according to claim 1. 4. An electronic component using the epoxy resin composition for molding according to claim 3 as a sealing material.