Epoxy resin composition

Abstract

The present invention is an epoxy resin composition characterized by comprising (A) an epoxy resin containing two or more epoxy groups in one molecule, (B) a urethane bond-containing polyorganosiloxane represented by formula (1), (C) a mesogenic group-containing polyorganosiloxane represented by formula (2), and (D) an epoxy resin curing agent. As a result, an epoxy resin composition comprising a polyorganosiloxane is provided. # imgabs0 #

Description

Technical Field

[0001] The present invention relates to an epoxy resin composition. Background Art

[0002] Epoxy resins are used in various fields due to their excellent physical strength, electrical insulation, heat resistance, chemical resistance, water resistance, low shrinkage, and adhesiveness. In recent years, the performance requirements for epoxy resins have increased, and development has been carried out on the technical problem of low toughness of epoxy resins (Patent Documents 1 to 4).

[0003] Epoxy-modified silicone is a polyorganosiloxane having an epoxy group and is used in applications such as resin modifiers, fiber treatment agents, and coating additives that utilize the reactivity of the epoxy group. In addition, although an effect of imparting flexibility to epoxy resins can be expected, there is a technical problem of poor compatibility with other polar compounds such as curing agents and separation.

[0004] Patent Document 5 describes an organosilicon having a urethane bond with epoxy groups introduced at both ends. In its examples, it was reported that a transparent solution could be obtained when mixed with bisphenol A-type epoxy resin, and a cured product was obtained by reaction with a curing agent. However, by adding this organosilicon, the glass transition temperature (Tg) of the epoxy resin itself decreases, so there is a problem of deterioration in heat resistance.

[0005] In Patent Document 6, an epoxy resin having a mesogenic group is disclosed, and it is reported that it has excellent workability and excellent physical, thermodynamic, and chemical properties. However, when the epoxy resin is mixed with a conventional epoxy resin such as bisphenol-type epoxy resin, how each physical property changes is not clear.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2008-239890

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2014-505761

[0010] Patent Document 3: Japanese Patent Application Laid-Open No. 2017-536440

[0011] Patent Document 4: International Publication No. 2018 / 008741

[0012] Patent Document 5: Japanese Patent Application Laid-Open No. 1986-228015

[0013] Patent Document 6: Japanese Patent Application Laid-Open No. 2008-214599 Summary of the Invention

[0014] (1) Technical problem to be solved

[0015] The present invention is made in view of the above circumstances, and its object is to provide an epoxy resin composition containing a polyorganosiloxane.

[0016] (2) Technical solution

[0017] To solve the above technical problems, the present invention provides an epoxy resin composition, which comprises:

[0018] (A) An epoxy resin containing two or more epoxy groups in one molecule,

[0019] (B) A urethane bond-containing polyorganosiloxane represented by the following formula (1),

[0020] (C) A mesogenic group-containing polyorganosiloxane represented by the following formula (2),

[0021] (D) An epoxy resin curing agent,

[0022] [Chemical formula 1]

[0023]

[0024] In the formula (1), R 1 each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms or a hydroxyl group, X each independently represents a divalent alkylene group having 1 to 10 carbon atoms, Y each independently represents a group selected from alkylene groups having 5 to 30 carbon atoms which may have an ether bond, arylene groups having 6 to 30 carbon atoms, and aralkyl groups having 7 to 30 carbon atoms, Z each independently represents an alkylene group having 1 to 20 carbon atoms which may have an ether bond, n is an integer of 0 to 100, and m is 1 to 10.

[0025] [Chemical formula 2]

[0026]

[0027] In the formula (2), R 1 each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms or a hydroxyl group, p represents a repeating unit of the siloxane structure and is an integer of 0 to 100, R 2 each independently represents the following formula (3) or formula (4).

[0028] [Chemical formula 3]

[0029]

[0030] [Chemical formula 4]

[0031]

[0032] In the formulas (3) and (4), R 3 and R 4 each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms; L is a linking group in the formula (2) and is a divalent hydrocarbon group having 1 to 12 carbon atoms; a and b represent the number of substituents on the phenyl group in the formulas (3) and (4) and are integers from 0 to 4; and G is a glycidyl ether group.

[0033] If it is such an epoxy resin composition, it becomes an epoxy resin composition containing a polyorganosiloxane with excellent various properties.

[0034] In addition, in the present invention, it is preferable to contain 1 to 20 parts by mass of the component (B) and 1 to 20 parts by mass of the component (C) with respect to 100 parts by mass of the component (A).

[0035] If it is such an epoxy resin composition, the strength or adhesiveness of the cured product of the epoxy resin can be sufficiently obtained. In addition, since the decrease in Tg can be suppressed, high heat resistance can be maintained.

[0036] In addition, in the present invention, it is preferable that the number average molecular weight of the component (B) in terms of polystyrene standard substance is 500 to 100,000.

[0037] If it is such an epoxy resin composition, the size of the structural body of the island structure constituting the sea-island structure does not become too large, and microphase separation can be formed. In addition, by selecting the number average molecular weight within this range, the size of the island structural body can be controlled.

[0038] In addition, in the present invention, it is preferable that the epoxy equivalent (g / mol) of the component (B) is 300 to 5,000 g / mol.

[0039] If it is such an epoxy resin composition, the size of the structural body of the island structure constituting the sea-island structure does not become too large, and microphase separation can be formed. In addition, by selecting the epoxy equivalent within this range, the size of the island structural body can be controlled.

[0040] In addition, in the present invention, it is preferable that the component (B) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

[0041] By reducing these cyclic low-molecular-weight siloxanes, it is possible to avoid a decrease in adhesiveness caused by the seepage of low-molecular components to the surface of the cured product, pollution of the surrounding environment caused by the volatilization of low-molecular components, and the like.

[0042] In addition, in the present invention, it is preferable that the number average molecular weight of the component (C) in terms of polystyrene standard substance is 500 to 100,000.

[0043] If it is such a molecular weight, this molecular weight is sufficient for the epoxy groups at both ends to react with the curing agent to obtain a cured product.

[0044] In addition, in the present invention, it is preferable that the epoxy equivalent weight (g / mol) of the component (C) is 300 to 5,000 g / mol.

[0045] If it is such an epoxy equivalent weight, this epoxy equivalent weight is an amount sufficient for the epoxy groups at both ends to react with the (C) epoxy resin curing agent to obtain a cured product with good physical properties.

[0046] In addition, in the present invention, it is preferable that the component (C) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

[0047] By reducing these cyclic low-molecular-weight siloxanes, it is possible to avoid a decrease in adhesiveness caused by the seepage of low-molecular components to the surface of the cured product, pollution of the surrounding environment caused by the volatilization of low-molecular components, and the like.

[0048] In addition, in the present invention, it is preferable that the (A) epoxy resin is a bisphenol type epoxy resin.

[0049] If it is such an epoxy resin composition, it becomes the following epoxy resin composition: It can strengthen the characteristics of the bisphenol type epoxy resin used through various selections, and can increase both the tensile property and the tensile shear strength compared with the case of using the bisphenol type epoxy resin monomer.

[0050] In addition, in the present invention, it is preferable that the (D) epoxy resin curing agent is an amine-based curing agent.

[0051] If it is such an epoxy resin composition, good curing characteristics can be obtained.

[0052] In addition, in the present invention, it is preferable to further contain an (E) filler.

[0053] If it is such an epoxy resin composition, the physical strength can be enhanced.

[0054] (III) Beneficial effects

[0055] The present invention relates to an epoxy resin composition containing a polyorganosiloxane. More specifically, it relates to an epoxy resin composition containing a polyorganosiloxane having epoxy groups at both ends and a urethane bond in the main chain, and a polyorganosiloxane having epoxy groups at both ends and a mesogenic group in the main chain.

[0056] By blending with a specific structure, the epoxy resin composition of the present invention is dispersed without phase separation when formed into a cured product, improves toughness without reducing the heat resistance of the cured product, and exhibits good adhesiveness when forming a cured product between substrates, so it has high utility. In addition, by reducing low-molecular cyclic siloxanes, when producing a cured product, it is possible to prevent problems such as accumulation in the device or malfunction of equipment caused by their volatilization and diffusion. Detailed Description of the Invention

[0057] As described above, there is a need to develop an epoxy resin composition containing a polyorganosiloxane with good properties.

[0058] The inventors of the present application repeatedly and seriously studied the above technical problems, and as a result, found that an epoxy resin composition containing (A) an epoxy resin, (B) a polyorganosiloxane containing a urethane bond, (C) a polyorganosiloxane containing a mesogenic group, and (D) an epoxy resin curing agent can solve the above technical problems, thereby completing the present invention.

[0059] That is, the present invention is an epoxy resin composition comprising:

[0060] (A) An epoxy resin containing two or more epoxy groups in one molecule,

[0061] (B) A polyorganosiloxane containing a urethane bond represented by the following formula (1),

[0062] (C) A polyorganosiloxane containing a mesogenic group represented by the following formula (2),

[0063] (D) An epoxy resin curing agent.

[0064] [Chemical Formula 5]

[0065]

[0066] (In the formula (1), R 1Each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, or a hydroxyl group, X each independently represents a divalent alkylene group having 1 to 10 carbon atoms, Y each independently represents a group selected from alkylene groups having 5 to 30 carbon atoms which may have an ether bond, arylene groups having 6 to 30 carbon atoms, and aralkyl groups having 7 to 30 carbon atoms, Z each independently represents an alkylene group having 1 to 20 carbon atoms which may have an ether bond, n is an integer of 0 to 100, and m is 1 to 10.)

[0067] [Chemical Formula 6]

[0068]

[0069] (In the formula (2), R 1 Each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, or a hydroxyl group, p represents a repeating unit of a siloxane structure and is an integer of 0 to 100, R 2 Each independently represents the following formula (3) or formula (4).)

[0070] [Chemical Formula 7]

[0071]

[0072] [Chemical Formula 8]

[0073]

[0074] (In the formula (3) and the formula (4), R 3 and R 4 Each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, L is a linking group with the formula (2) and is a divalent hydrocarbon group having 1 to 12 carbon atoms, a and b represent the number of substituents on the phenyl group in the formula (3) and the formula (4) and are integers of 0 to 4, and G is a glycidyl ether group.)

[0075] [Epoxy Resin Composition]

[0076] The epoxy resin composition of the present invention is an epoxy resin composition containing (A) an epoxy resin, (B) a polyorganosiloxane containing a urethane bond, (C) a polyorganosiloxane containing a mesogenic group, and (D) an epoxy resin curing agent.)

[0077] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.)

[0078] [(A) Epoxy Resin]

[0079] The (A) epoxy resin in the present invention contains two or more epoxy groups in one molecule. This epoxy resin can be a known epoxy resin without particular limitation. For example, bisphenol type epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, and bisphenol S type epoxy resin can be mentioned; alicyclic epoxy resins such as dicyclopentadiene type epoxy resin and 3,4-epoxycyclohexenylmethyl-3',4'-epoxycyclohexene carboxylate; polyfunctional phenol type epoxy resins such as resorcinol type epoxy resin; and polycyclic aromatic-based diglycidyl ether compounds such as stilbene type epoxy resin, epoxy resin containing a triazine skeleton, epoxy resin containing a fluorene skeleton, triphenolalkane type epoxy resin, biphenyl type epoxy resin, benzene dimethylene type epoxy resin, biphenyl aralkyl type epoxy resin, naphthalene type epoxy resin, and anthracene. They can be used alone or two or more of them can be used simultaneously. Bisphenol type epoxy resin is preferred. In addition, in the present invention, the (A) component, the (B) component, and the (C) component are different from each other.

[0080] The epoxy equivalent of the (A) epoxy resin is not particularly limited. From the perspectives of the pot life after mixing or the strength of the cured product, etc., in terms of the solid content per unit, it is preferably 50 to 5,000 g / eq, more preferably 75 to 2,500 g / eq.

[0081] The viscosity of the (A) epoxy resin is not particularly limited. It is preferably liquid at 25°C, and the viscosity is 10 to 100,000 mPa·s, preferably 20 to 50,000 mPa·s. The viscosity is measured using a B-type viscometer.

[0082] [(B) Polyorganosiloxane containing a urethane bond]

[0083] The (B) polyorganosiloxane containing a urethane bond in the present invention is a compound represented by the following formula (1).

[0084] [Chemical formula 9]

[0085]

[0086] (In the formula (1), R 1 independently represent a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms or a hydroxyl group; X independently represent divalent alkylene groups having 1 to 10 carbon atoms; Y independently represent a group selected from alkylene groups having 5 to 30 carbon atoms which may have an ether bond, arylene groups having 6 to 30 carbon atoms, and aralkyl groups having 7 to 30 carbon atoms; Z independently represent alkylene groups having 1 to 20 carbon atoms which may have an ether bond; n is an integer from 0 to 100; and m is 1 to 10.)

[0087] In formula (1), R1 They are independent of each other, and groups or hydroxyl groups selected from alkyl groups having 1 to 12 carbon atoms, preferably alkyl groups having 1 to 8 carbon atoms, aryl groups having 6 to 12 carbon atoms, preferably aryl groups having 6 to 9 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, preferably aralkyl groups having 7 to 10 carbon atoms can be listed. As specific examples thereof, linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl, naphthyl, etc., and aralkyl groups such as benzyl can be listed. Among them, methyl or phenyl is preferred.

[0088] In formula (1), Xs are independently alkylene groups having 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms.

[0089] As specific examples of the alkylene group having 1 to 10 carbon atoms, methylene, ethylene, propylene, n-hexenyl, n-octenyl, etc. can be listed. Methylene is preferred.

[0090] In formula (1), Ys are independently groups selected from alkylene groups having 5 to 30 carbon atoms, arylene groups having 6 to 30 carbon atoms, and aralkyl groups having 7 to 30 carbon atoms.

[0091] As the alkylene group having 5 to 30 carbon atoms, it can be any of linear, branched, and cyclic. As specific examples thereof, linear or branched alkylene groups such as n-pentenyl, n-hexenyl, n-heptenyl, n-octenyl, 2-ethylhexenyl, n-decenyl, n-undecenyl, n-dodecenyl, n-tridecenyl, n-tetradecenyl, n-pentadecenyl, n-hexadecenyl, n-heptadecenyl, n-octadecenyl, n-nonadecenyl, n-icosene can be listed.

[0092] In addition, the alkylene group may have one or more ether bonds in the middle of the molecular chain. Specifically, it is a group containing an ether bond such as ethoxy, propoxy, butoxy, etc., and there can be multiple ether bonds.

[0093] As the arylene group having 6 to 30 carbon atoms, o-phenylene, m-phenylene, p-phenylene, 3,5-benzylidene, 2,4-benzylidene, 2,6-benzylidene, 1,2-naphthylene, 1,8-naphthylene, 2,3-naphthylene, 4,4'-biphenylene, etc., 4,4'-methylenediphenyl, etc. can be listed.

[0094] As the aralkyl group having 7 to 30 carbon atoms, o-phenylenedimethylene, m-phenylenedimethylene, p-phenylenedimethylene, 1,3-phenylenebis(2-propyl) group, etc. can be listed.

[0095] As the Y, the following groups can be preferably cited. The dotted line indicates the connection position to the nitrogen atom of the urethane bond in the formula (1), and hydrogen atoms are omitted according to convention.

[0096] [Chemical formula 10]

[0097]

[0098] In the formula (1), Z are each independently an alkylene group having 1 to 20 carbon atoms, preferably an alkylene group having 3 to 10 carbon atoms. In addition, one or more ether bonds may be present in the alkylene chain having 1 to 20 carbon atoms. Preferred are propylene group (-CH2CH2CH2-), glycidoxypropyl group (*-CH2CH2OCH2CH2CH2-), where * represents the bond to the oxygen atom of the urethane bond in the formula (1).

[0099] In the formula (1), n represents an integer of 0 to 100. Preferably, n is an integer of 0 to 60.

[0100] In the formula (1), m represents the average degree of polymerization, and m is 1 to 10, preferably 1 or 2.

[0101] The number average molecular weight of the (B) urethane bond-containing polyorganosiloxane in the present invention is preferably 500 to 100,000, more preferably 500 to 50,000, and further preferably 500 to 20,000. If it is in this range, it is a molecular weight sufficient for the epoxy groups at both ends to react with the curing agent and obtain a cured product. In addition, the number average molecular weight refers to the number average molecular weight in terms of polystyrene standard substance in the gel permeation chromatography (GPC) measurement based on the following measurement conditions.

[0102] [Measurement conditions]

[0103] Developing solvent: Tetrahydrofuran (THF)

[0104] Flow rate: 0.6 mL / min

[0105] Detector: Differential refractive index detector (RI)

[0106] Chromatographic column: TSK Guardcolumn SuperH-H

[0107] TSKgel SuperHM-N (6.0 mm I.D.×15 cm×1)

[0108] TSKgel SuperH2500 (6.0 mm I.D.×15 cm×1)

[0109] (All are manufactured by TOSOH CORPORATION)

[0110] · Column temperature: 40 °C

[0111] Sample injection volume: 50 μL (THF solution with a concentration of 0.3 mass%)

[0112] In the present invention, the epoxy equivalent (g / mol) of the urethane bond-containing polyorganosiloxane (B) is preferably 300 to 5,000 g / mol, more preferably 400 to 2,500 g / mol. If it is within this range, it is an amount sufficient for the epoxy groups at both ends to react with the curing agent and obtain a cured product with good physical properties. The epoxy equivalent (g / mol) can be calculated as follows: Hydrochloric acid is added to a specified mass of the sample dissolved in 1,4-dioxane, and back titration is performed using an aqueous sodium hydroxide solution.

[0113] As described in International Publication No. 2016 / 111104, etc., low-molecular cyclic siloxanes may cause various adverse conditions and are preferably reduced. It is possible to use the urethane bond-containing polyorganosiloxane (B) represented by the following formula (1) containing hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of preferably 3,000 ppm or less, more preferably 2,000 ppm or less, and further preferably 1,000 ppm or less.

[0114] A sample obtained by extracting and diluting the urethane bond-containing polyorganosiloxane (B) represented by the formula (1) with an organic solvent can be used, and the amount of the above low-molecular cyclic siloxanes (D3 to D6) can be quantified by gas chromatography (GC).

[0115] [(C) Mesogenic group-containing polyorganosiloxane]

[0116] The mesogenic group-containing polyorganosiloxane in the present invention is a compound represented by the following formula (2).

[0117] [Chemical formula 11]

[0118]

[0119] (In the formula (2), R 1 each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms, or a hydroxyl group, p represents a repeating unit of the siloxane structure and is an integer of 0 to 100, and R 2 each independently represents the following formula (3) or formula (4).)

[0120] In the formula (2), R 1They are independent of each other, and groups identical to those listed in the formula (1) can be enumerated.

[0121] p represents the number of repeating units of the siloxane structure, which is an integer from 0 to 100, preferably from 0 to 40, more preferably from 0 to 10, and further preferably p = 1.

[0122] In formula (2), R 2 are each independently the following formula (3) or (4).

[0123] [Chemical formula 12]

[0124]

[0125] [Chemical formula 13]

[0126]

[0127] (In the formula (3) and the formula (4), R 3 and R 4 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, L is a linking group of the formula (2) and is a divalent hydrocarbon group having 1 to 12 carbon atoms, a and b represent the number of substituents on the phenyl group in the formula (3) and the formula (4) and are integers from 0 to 4, and G is a glycidyl ether group.)

[0128] In formulas (3) and (4), R 3 and R 4 each independently represent a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0129] As the monovalent hydrocarbon group having 1 to 10 carbon atoms, it is preferably a group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an aralkyl group having 7 to 10 carbon atoms, and specific examples thereof can be groups identical to those exemplified in the formula (1).

[0130] a and b represent the number of substituents on the phenyl group in formulas (3) and (4) and are integers from 0 to 4.

[0131] G in formulas (3) and (4) is a glycidyl group.

[0132] L in formulas (3) and (4) is a linking group of formula (2) and is a divalent hydrocarbon group having 1 to 12 carbon atoms.

[0133] As the divalent hydrocarbon group, an alkylene group having 1 to 12 carbon atoms, an arylene group having 6 to 12 carbon atoms, or an aralkylene group having 7 to 12 carbon atoms can be enumerated.

[0134] The alkylene group having 1 to 12 carbon atoms may be any of linear, branched, and cyclic types. Specific examples thereof include linear or branched alkylene groups such as n-pentenyl, n-hexenyl, n-heptenyl, n-octenyl, 2-ethylhexenyl, n-decenyl, n-undecenyl, and n-dodecenyl.

[0135] In addition, the alkylene group may have one or more ether bonds in the middle of the molecular chain. Specifically, they are groups containing ether bonds such as ethoxy, propoxy, and butoxy, and there may be multiple ether bonds.

[0136] Examples of the arylene group having 6 to 12 carbon atoms include o-phenylene, m-phenylene, p-phenylene, 3,5-benzylidene, 2,4-benzylidene, 2,6-benzylidene, 1,2-naphthylene, 1,8-naphthylene, 2,3-naphthylene, 4,4'-biphenylene, etc.

[0137] Examples of the aralkyl group having 7 to 12 carbon atoms include o-phthalylidene, m-phthalylidene, p-phthalylidene, etc.

[0138] R in formula (2) 2 More preferably, it is formula (5).

[0139] [Chemical formula 14]

[0140]

[0141] c represents the number of carbon atoms of the linking group to the siloxane backbone in formula (5), which is an integer of 0 to 6, and preferably c = 1.

[0142] The dashed line represents the connection position to formula (2).

[0143] The number-average molecular weight of the (C) mesogenic group-containing polyorganosiloxane in the present invention is preferably 500 to 100,000, more preferably 500 to 50,000, and further preferably 500 to 20,000. If it is within this range, it is a molecular weight sufficient for the epoxy groups at both ends to react with the curing agent to obtain a cured product. In addition, the number-average molecular weight is the same as above.

[0144] The epoxy equivalent (g / mol) of the (C) mesogenic group-containing polyorganosiloxane in the present invention is preferably 300 to 5,000 g / mol, more preferably 400 to 2,500 g / mol. If it is within this range, it is an amount sufficient for the epoxy groups at both ends to react with the following (D) epoxy resin curing agent to obtain a cured product with good physical properties. The epoxy equivalent (g / mol) can be calculated as follows: Hydrochloric acid is added to a specified mass of the sample dissolved in 1,4-dioxane, and back titration is carried out using an aqueous sodium hydroxide solution.

[0145] As described in International Publication No. 2016 / 111104 etc., low-molecular cyclic siloxanes may cause various adverse conditions and are preferably reduced. It is possible to use the component (C) containing hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of preferably more than 0 ppm and 3,000 ppm or less, more preferably 0.1 to 2,000 ppm, and further preferably 0.1 to 1,000 ppm.

[0146] A sample obtained by extracting and diluting the component (C) with an organic solvent can be used, and the amounts of the above-mentioned low-molecular cyclic siloxanes (D3 to D6) can be quantified by gas chromatography (GC). In addition, for the "more than 0 ppm", when quantified by the above method, the case where even a very small amount is detected as a peak is regarded as "more than 0 ppm".

[0147] In the present invention, when the component (A) is set to 100 parts by mass, the component (B) is preferably 1 to 20 parts by mass, more preferably 10 to 20 parts by mass. Similarly, the component (C) is preferably 1 to 20 parts by mass, more preferably 1 to 10 parts by mass. If the parts by mass of the component (B) and the component (C) are within this range, it is sufficient to obtain the strength or adhesiveness of the cured product of the epoxy resin. In addition, since the decrease in Tg can be suppressed, high heat resistance can be maintained.

[0148] [(D) Epoxy resin curing agent]

[0149] In the present invention, as the (D) epoxy resin curing agent, a known curing agent that can react with and cure the epoxy resin can be used. This curing agent is added in order to make the reactive functional groups (amino group, phenolic hydroxyl group, acid anhydride group, mercapto group, etc.) in the molecule of the curing agent react with the epoxy groups in the component (A), the component (B), and the component (C), and form a cured product with a three-dimensional crosslinked structure.

[0150] Examples of the component (D) include amine-based curing agents, phenol-based curing agents, acid anhydride-based curing agents, and mercaptan-based curing agents.

[0151] Among them, amine-based curing agents are preferred. Examples of amine-based curing agents include aromatic polyamines, aliphatic polyamines, polyamidoamines, polyether polyamines, etc. Aromatic polyamines are further preferred.

[0152] Examples of aromatic polyamines include compounds represented by the following formulas (I) to (IV).

[0153] [Chemical formula 15]

[0154]

[0155] (In formulas (I) to (IV), each R is independently a hydrogen atom or a monovalent alkyl group having 1 to 6 carbon atoms, each R' is independently a hydrogen atom, a monovalent alkyl group having 1 to 12 carbon atoms, a phenyl group, or an aminophenyl group, and two R's may be bonded to form a ring structure together with the carbon atom to which they are bonded.)

[0156] Specific examples of the aromatic polyamine include aromatic diamino diphenylmethane compounds such as 4,4'-diaminodiphenylmethane, 3,3'-diethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetraethyl-4,4'-diaminodiphenylmethane, etc., 2,4-diaminotoluene, 1,4-diaminobenzene, 1,3-diaminobenzene, etc. They can be used alone or two or more of them can be used simultaneously.

[0157] In the present invention, when the component (A) is 100 parts by mass, the component (D) is preferably 1 to 20 parts by mass, more preferably 1 to 10 parts by mass. If the mass part of the component (D) is 20 parts by mass or less, it is sufficient to obtain the strength or adhesiveness of the cured product of the epoxy resin. In addition, since the decrease in Tg can be suppressed, high heat resistance can be maintained. If the mass part of the component (D) is 1 part by mass or more, the desired addition effect of the component (D) becomes sufficient.

[0158] [Other components]

[0159] The epoxy resin composition of the present invention may further contain an (E) filler. As the filler, for example, silica-based materials such as fused silica, crystalline silica, and cristobalite, metal oxide-based materials such as alumina, titanium oxide, and magnesium oxide, etc. can be mentioned. One kind can be used alone, or two or more kinds can be used simultaneously. Among them, from the viewpoints of availability and quality stability, silica-based materials are preferred. The average particle size is preferably 0.1 to 50 μm and can be selected according to the use. The average particle size may be, for example, the volume average particle size measured by the laser diffraction method.

[0160] The above-mentioned filler is preferably surface-treated in advance with a coupling agent such as a silane coupling agent. In addition, the blending amount of the coupling agent for surface treatment and the surface treatment method are not particularly limited.

[0161] The epoxy resin composition of the present invention can add other additives according to needs for the purpose of the present invention. As the additives, reactive diluents, curing accelerators, flame retardants, ion trap agents, antioxidants, adhesion aids, colorants, coupling agents, etc. can be mentioned.

[0162] The preparation method of the epoxy resin composition of the present invention can, for example, obtain the composition by heating and mixing, stirring, dissolving, and dispersing the components (A), (B), (C), and (D) simultaneously. In addition, the composition can also be obtained by heating and mixing, stirring, dissolving, and dispersing the components (A), (B), (C), or (D) separately. Preferably, the composition in which the component (B) is well dispersed can be obtained by heating and mixing, stirring, dissolving, and dispersing the components (B), (C), and (D) simultaneously, and then adding the component (A).

[0163] In addition, the component (E) and / or other additives can be added as needed. The component (E) and / or other additives can be added while heating the components (A), (B), (C), and (D) simultaneously or separately, and mixing, stirring, dissolving, and dispersing. Alternatively, the component (E) and / or other additives can be added to the components (B), (C), and (D) while heating and mixing, stirring, dissolving, and dispersing, and then added to the component (A) simultaneously.

[0164] The curing conditions of the epoxy resin composition of the present invention are not particularly limited. For example, it can be heated at a temperature of 60 to 200 °C, preferably 80 to 180 °C, for 30 minutes to 10 hours, preferably 1 to 5 hours. In addition, in order to effectively carry out the reaction, for example, it can be heated from a lower temperature to a higher temperature in 1 to 5 stages for the above-mentioned time.

[0165] Examples

[0166] Hereinafter, the present invention will be specifically described using examples, comparative examples, and synthesis examples, but the present invention is not limited thereto.

[0167] Bisphenol A type epoxy resin: jER828EL manufactured by Mitsubishi Chemical Corporation

[0168] (Epoxy equivalent: 186 g / mol, viscosity: 13,000 mPa·s)

[0169] (Hereinafter, referred to as DGEBA.)

[0170] Amine curing agent: 4,4'-Diaminodiphenylmethane (N-H equivalent: 49.6 g / mol) manufactured by Tokyo Chemical Industry Co., Ltd.

[0171] (Hereinafter, referred to as DDM.)

[0172] [Synthesis Example 1] Synthesis method of SU epoxy resin

[0173] In a 500 mL separating flask, 91.95 g (0.827 moles of NCO) of isophorone diisocyanate was charged. A mechanical stirrer, stirring blades, Dimroth reflux condenser, nitrogen inlet, and thermometer were installed, and nitrogen was introduced. Then, 0.32 g (0.1 mass%) of K-KAT XK-640 (bismuth carboxylate manufactured by Kusumoto Chemicals, Ltd., containing 18% bismuth) as a catalyst was added, and the temperature was raised to an internal temperature of 60 °C. Using a 300 mL dropping funnel, 200.00 g (0.413 moles of OH, NCO / OH = 2.0) of 3-(2-polydimethyl)propyl dimethyl siloxanyl-terminated polydimethylsiloxane (n = 8, OH value 116 mg KOH / g) with D3 of 64 ppm, D4 of 59 ppm, D5 of 23 ppm, and D6 of 226 ppm was added to the above separating flask over 30 minutes, and then aged at 70 °C for 3 hours. Then, 30.80 g (0.415 moles) of glycidol was added, and aged at 70 °C for 2 hours, thereby obtaining 319.17 g of a colorless slightly turbid viscous liquid. According to NCO / OH = 2.0, m is 1.

[0174] For low-molecular-weight cyclic siloxanes, extraction was carried out using hexane with tetradecane as an internal standard at 10 mL per 1 g of sample, and GC-based measurement was performed. As a result, the total amount of D3 to D6 was 305 ppm. (D3: 54 ppm, D4: 52 ppm, D5: 16 ppm, D6: 183 ppm)

[0175] [Synthesis Example 2] Synthesis method of SM epoxy resin

[0176] In a glass reactor, 360 mL of ethanol, 17.9 g (0.164 mol) of p-aminophenol, 20 g (0.164 mol) of 4-allyloxybenzaldehyde, and a small amount of zinc chloride were added, and the reaction was carried out in an oil bath at 60 °C for 4 hours. Then, it was left to stand in a refrigerator for 2 hours, and the precipitated crystals were filtered to obtain 27 g of 4-((4-allyloxy)benzylideneamino)phenol.

[0177] Next, in a 500 ml separating flask, 7 g (0.033 mol) of the obtained 4-((4-allyloxy)benzylideneamino)phenol, 5 mL of dimethyl sulfoxide, 37 g of epichlorohydrin (0.394 mol), and a small amount of tetra-n-butylammonium chloride were added, and the reaction was carried out at 60 °C for 2 hours. Then, 3.16 g (0.04 mol) of 50% aqueous sodium hydroxide solution was added dropwise over 1 hour, and the reaction was further carried out for 3 hours. The obtained solution was cooled, the precipitated crystals were filtered, and after thoroughly washing with distilled water, it was dried to obtain 3.9 g of 4-((4-allyloxy)benzylideneamino)phenol glycidyl ether.

[0178] Place 2 g (6.5 mmol) of 4-((4-allyloxy)benzylideneamino)phenol glycidyl ether in a separatory flask and dissolve it in 40 mL of 1,4-dioxane. Further, add 0.667 g (3.24 mmol) of 1,1,3,3,5,5-hexamethyltrisiloxane and 0.02 g (0.06 mmol) of 1,3-divinyl-1,1,3,3-tetramethyldisiloxane platinum complex. Raise the temperature of the oil bath to 90 °C and heat with stirring for 6 hours.

[0179] Cool the reaction solution, filter the precipitated crystals, and wash them thoroughly with methanol to obtain white crystals. Measure the amounts of low-molecular cyclic siloxanes (D3 - D6) in the obtained SM epoxy resin, and the results are all below the detection limit.

[0180] [Example 1]

[0181] Put the defoamed DGEBA, Synthesis Example 1, and Synthesis Example 2 into an aluminum cup and heat them on a hot plate at 130 °C for the purpose of reducing viscosity. Then, put the stoichiometric amount of DDM into another aluminum cup and stir it on a hot plate at the same temperature until it completely melts. Then, add the melted DDM to the pre-prepared aluminum cup and stir for 5 minutes to prepare a composition.

[0182] Then, cure the aluminum cup containing the above composition by heating in three stages: heating and curing at 120 °C for 2 hours, heating and curing at 150 °C for 2 hours, and heating and curing at 180 °C for 2 hours. Additionally, the heating rate is 5 °C / min. Record the blending amounts and physical properties of the cured product in Table 1.

[0183] [Example 2]

[0184] Add Synthesis Example 1, Synthesis Example 2, and the melted DDM stoichiometric to all epoxy groups into an aluminum cup and stir on a hot plate at 140 °C for 15 minutes. Then, put the defoamed DGEBA into another aluminum cup and heat it on a hot plate at the same temperature for the purpose of reducing viscosity. Then, add the DGEBA with reduced viscosity to the pre-prepared aluminum cup, heat and stir for 2 minutes to prepare a composition.

[0185] Then, use a constant temperature bath to cure the aluminum cup containing the above composition by heating in three stages: heating and curing at 120 °C for 2 hours, heating and curing at 150 °C for 2 hours, and heating and curing at 180 °C for 2 hours. Additionally, the heating rate is 5 °C / min. Record the blending amounts and physical properties of the cured product in Table 1.

[0186] [Comparative Example 1]

[0187] The defoamed DGEBA was placed in an aluminum cup and heated on a hot plate at 130 °C for the purpose of reducing viscosity. Subsequently, the chemically equivalent DDM was placed in another aluminum cup and stirred on a hot plate at the same temperature until it was completely melted. Then, the melted DDM was added to the aluminum cup containing DGEBA and stirred for 5 minutes to prepare a composition.

[0188] Then, using a thermostat, the aluminum cup containing the above composition was heated and cured in three stages: heating and curing at 120 °C for 2 hours, heating and curing at 150 °C for 2 hours, and heating and curing at 180 °C for 2 hours. Additionally, the heating rate was 5 °C / min. The blending amounts and physical properties of the cured products are shown in Table 1.

[0189] [Comparative Example 2]

[0190] The defoamed DGEBA and Synthesis Example 1 were placed in an aluminum cup and heated on a hot plate at 130 °C for the purpose of reducing viscosity. Subsequently, the chemically equivalent DDM was placed in another aluminum cup and stirred on a hot plate at the same temperature until it was completely melted. Then, the melted DDM was added to the pre-prepared aluminum cup and stirred for 5 minutes to prepare a composition.

[0191] Then, the aluminum cup containing the above composition was heated and cured in three stages: heating and curing at 120 °C for 2 hours, heating and curing at 150 °C for 2 hours, and heating and curing at 180 °C for 2 hours. Additionally, the heating rate was 5 °C / min. The blending amounts and physical properties of the cured products are shown in Table 1.

[0192] [Comparative Example 3]

[0193] The defoamed DGEBA and Synthesis Example 2 were placed in an aluminum cup and heated on a hot plate at 130 °C for the purpose of reducing viscosity. Subsequently, the chemically equivalent DDM was placed in another aluminum cup and stirred on a hot plate at the same temperature until it was completely melted. Then, the melted DDM was added to the pre-prepared aluminum cup and stirred for 5 minutes to prepare a composition.

[0194] Then, the aluminum cup containing the above composition was heated and cured in three stages: heating and curing at 120 °C for 2 hours, heating and curing at 150 °C for 2 hours, and heating and curing at 180 °C for 2 hours. Additionally, the heating rate was 5 °C / min. The blending amounts and physical properties of the cured products are shown in Table 1.

[0195] [Dynamic Viscoelasticity Measurement]

[0196] The cured products of Examples 1 to 2 and Comparative Examples 1 to 3 were cut into test piece sizes of 30 mm in length × 4.0 mm in width × 0.40 mm in thickness, and measured using Rheogel-E40000 manufactured by UBM CORPORATION under the conditions of a temperature range of -150 to 250 °C, sine wave, heating rate of 2.5 °C / min, tensile mode, and frequency of 10 Hz. For the obtained results, the peak of the loss tangent tanδ, which is the loss modulus (G”) / storage modulus (G’), was taken as Tg.

[0197] [Table 1]

[0198]

[0199] [Examples 3 to 4, Comparative Examples 4 to 6]

[0200] [Tensile Shear Bonding Test]

[0201] The mild steel plate was immersed in acetone and ultrasonically cleaned for 30 minutes. Then, using an electric sander equipped with #240 abrasive paper, the mild steel plate was polished to remove the surface oxide film, immersed in acetone, and ultrasonically cleaned twice for 30 minutes each. Then, a plate (25 mm in length × 25 mm in width × 1.6 mm in thickness) was attached to a portion 62.5 mm from the end of the mild steel plate. Then, the composition prepared in each example was applied 12.5 mm from the end of the mild steel plate, another mild steel plate was laminated, and using a hot press, it was heated at 120 °C under 5 MPa for 2 hours. Then, in a constant temperature bath, a weight (weight: 1,700 g, pressure: 960 Pa) was placed on the test piece, heated at 150 °C for 2 hours, then heated and cured at 180 °C at a heating rate of 5 °C / min for 2 hours to make a test piece. After slow cooling, the test piece was taken out, and the resin exposed from the joint was removed using a utility knife.

[0202] Using AGS-X manufactured by SHIMADZU CORPORATION, a tensile shear bonding test was conducted on the obtained test pieces under the condition of a head speed of 50 mm / min. The average values of the breaking strength and elongation at break were taken for N = 5. The failure mode was confirmed visually. The results of the composition for evaluation and the tensile shear bonding test are shown in Table 2.

[0203] [T-Peel Test]

[0204] Using aluminum foil (length: 200 mm × width: 500 mm × thickness: 0.05 mm), the composition prepared in each example was coated at a position 170 mm from the end of the aluminum foil. Another piece of aluminum foil was laminated, and using a hot press, it was heated at 120 °C for 2 hours under 5 MPa. Then, in a constant temperature bath, weights (weight: 1,700 g, pressure: 960 Pa) were placed on the test piece. After heating at 150 °C for 2 hours, the temperature was raised to 180 °C at a rate of 5 °C / min and heated and cured at 180 °C for 2 hours to prepare a test piece. After slow cooling, the aluminum foil was taken out and cut to a width of 25 mm to obtain a test piece.

[0205] Using AGS-X manufactured by SHIMADZU CORPORATION, a T-peel test was performed on the obtained test piece under the condition that the head speed was 100 mm / min. The average test force between 150 mm after removing 25 mm at the start and end of the test of the test piece was taken as the peel strength, and the average value of N = 5 was taken. The failure mode was confirmed by the naked eye. The composition used for evaluation and the results of the T-peel test are shown in Table 2.

[0206] [Table 2]

[0207]

[0208] Compared with the comparative examples, in the tensile shear adhesion test and T-peel test of the examples, an increase in the fracture strength and peel strength was observed. This indicates that the epoxy resin of the present invention is effective in improving the adhesion to the substrate, thereby showing the usefulness of the epoxy resin composition of the present invention.

[0209] This specification includes the following aspects.

[0210] [1]: An epoxy resin composition, characterized in that it contains:

[0211] (A) An epoxy resin containing 2 or more epoxy groups in one molecule,

[0212] (B) A urethane bond-containing polyorganosiloxane represented by the following formula (1),

[0213] (C) A mesogenic group-containing polyorganosiloxane represented by the following formula (2),

[0214] (D) An epoxy resin curing agent,

[0215] [Chemical formula 16]

[0216]

[0217] In the formula (1), R 1Each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms or a hydroxyl group, X each independently represents a divalent alkylene group having 1 to 10 carbon atoms, Y each independently represents a group selected from alkylene groups having 5 to 30 carbon atoms which may have an ether bond, arylene groups having 6 to 30 carbon atoms, and aralkyl groups having 7 to 30 carbon atoms, Z each independently represents an alkylene group having 1 to 20 carbon atoms which may have an ether bond, n is an integer of 0 to 100, and m is 1 to 10.

[0218] [Chemical Formula 17]

[0219]

[0220] In the formula (2), R 1 Each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, and aralkyl groups having 7 to 12 carbon atoms or a hydroxyl group, p represents a repeating unit of a siloxane structure and is an integer of 0 to 100, R 2 Each independently represents the following formula (3) or formula (4).

[0221] [Chemical Formula 18]

[0222]

[0223] [Chemical Formula 19]

[0224]

[0225] In the formula (3) and the formula (4), R 3 and R 4 Each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, L is a linking group with the formula (2) and is a divalent hydrocarbon group having 1 to 12 carbon atoms, a and b represent the number of substituents on the phenyl group in the formula (3) and the formula (4) and are integers of 0 to 4, and G is a glycidyl ether group.

[0226] [2]: The epoxy resin composition according to [1] above, characterized in that it contains 1 to 20 parts by mass of the component (B) and 1 to 20 parts by mass of the component (C) relative to 100 parts by mass of the component (A).

[0227] [3]: The epoxy resin composition according to [1] or [2] above, characterized in that the number average molecular weight of the component (B) in terms of polystyrene standard substance is 500 to 100,000.

[0228] [4]: The epoxy resin composition according to any one of [1] to [3] above, characterized in that the epoxy equivalent (g / mol) of the component (B) is 300 to 5,000 g / mol.

[0229] [5]: The epoxy resin composition according to any one of [1] to [4] above, characterized in that the component (B) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

[0230] [6]: The epoxy resin composition according to any one of [1] to [5] above, characterized in that the number average molecular weight of the component (C) in terms of polystyrene standard substance is 500 to 100,000.

[0231] [7]: The epoxy resin composition according to any one of [1] to [6] above, characterized in that the epoxy equivalent (g / mol) of the component (C) is 300 to 5,000 g / mol.

[0232] [8]: The epoxy resin composition according to any one of [1] to [7] above, characterized in that the component (C) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

[0233] [9]: The epoxy resin composition according to any one of [1] to [8] above, characterized in that the (A) epoxy resin is a bisphenol type epoxy resin.

[0234]

[10] : The epoxy resin composition according to any one of [1] to [9] above, characterized in that the (D) epoxy resin curing agent is an amine-based curing agent.

[0235]

[11] : The epoxy resin composition according to any one of [1] to

[10] above, characterized in that it further contains an (E) filler.

[0236] In addition, the present invention is not limited to the above embodiments. The above embodiments are examples, and technical solutions having the same constitution as the technical concept described in the claims of the present invention and exhibiting the same technical effects are all included in the protection scope of the present invention.

Claims

1. An epoxy resin composition, characterized in that, It contains: (A) An epoxy resin containing two or more epoxy groups in one molecule, (B) A urethane bond-containing polyorganosiloxane represented by the following formula (1), (C) A mesogenic group-containing polyorganosiloxane represented by the following formula (2), (D) An epoxy resin curing agent, [Chemical formula 1] In the formula (1), R 1 each independently represents a group selected from alkyl groups having 1 to 12 carbon atoms, aryl groups having 6 to 12 carbon atoms, aralkyl groups having 7 to 12 carbon atoms, or a hydroxyl group; X each independently represents a divalent alkylene group having 1 to 10 carbon atoms; Y each independently represents a group selected from alkylene groups having 5 to 30 carbon atoms which may optionally have an ether bond, arylene groups having 6 to 30 carbon atoms, and aralkyl groups having 7 to 30 carbon atoms; Z each independently represents an alkylene group having 1 to 20 carbon atoms which may optionally have an ether bond; n is an integer from 0 to 100; m is from 1 to 10, [Chemical formula 2] In the formula (2), R 1 each independently represents a group selected from an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, or a hydroxyl group; p represents a repeating unit of a siloxane structure and is an integer of 0 to 100; R 2 each independently represents the following formula (3) or formula (4). [Chemical formula 3] [Chemical formula 4] In the formula (3) and the formula (4), R 3 and R 4 each independently represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms, L is a linking group with the formula (2) and is a divalent hydrocarbon group having 1 to 12 carbon atoms, a and b represent the number of substituents on the phenyl group in the formula (3) and the formula (4) and are integers from 0 to 4, and G is a glycidyl ether group.

2. The epoxy resin composition according to claim 1, characterized in that, It contains 1 to 20 parts by mass of the component (B) relative to 100 parts by mass of the component (A), and 1 to 20 parts by mass of the component (C) relative to 100 parts by mass of the component (A).

3. The epoxy resin composition according to claim 1, characterized in that, The number average molecular weight of the component (B) in terms of polystyrene standard substance is 500 to 100,000.

4. The epoxy resin composition according to claim 1, characterized in that, The epoxy equivalent (g / mol) of the component (B) is 300 to 5,000 g / mol.

5. The epoxy resin composition according to claim 1, characterized in that, The component (B) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

6. The epoxy resin composition according to claim 1, characterized in that, The number average molecular weight of the component (C) in terms of polystyrene standard substance is 500 to 100,000.

7. The epoxy resin composition according to claim 1, characterized in that, The epoxy equivalent (g / mol) of the component (C) is 300 to 5,000 g / mol.

8. The epoxy resin composition according to claim 1, characterized in that, The component (C) contains hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylcyclohexasiloxane (D6) in a total amount of 3,000 ppm or less.

9. The epoxy resin composition according to claim 1, characterized in that, The (A) epoxy resin is a bisphenol type epoxy resin.

10. The epoxy resin composition according to claim 1, characterized in that, The (D) epoxy resin curing agent is an amine-based curing agent.

11. The epoxy resin composition according to any one of claims 1 to 10, characterized in that, It further contains (E) a filler.

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