WO2016098709A1 - Epoxy resin composition, resin sheet, prepreg, laminate, process for producing epoxy resin composition, and cured object - Google Patents

Epoxy resin composition, resin sheet, prepreg, laminate, process for producing epoxy resin composition, and cured object Download PDF

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Publication number
WO2016098709A1
WO2016098709A1 PCT/JP2015/084842 JP2015084842W WO2016098709A1 WO 2016098709 A1 WO2016098709 A1 WO 2016098709A1 JP 2015084842 W JP2015084842 W JP 2015084842W WO 2016098709 A1 WO2016098709 A1 WO 2016098709A1
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epoxy resin
resin composition
group
iii
inorganic filler
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PCT/JP2015/084842
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French (fr)
Japanese (ja)
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優香 吉田
片木　秀行
竹澤　由高
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日立化成株式会社
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Priority to JP2016564834A priority Critical patent/JPWO2016098709A1/en
Publication of WO2016098709A1 publication Critical patent/WO2016098709A1/en

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
    • C08J5/241—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres
    • C08J5/244—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs using inorganic fibres using glass fibres
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
    • B32B5/22—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed
    • B32B5/24—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer
    • B32B5/28—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by the presence of two or more layers which are next to each other and are fibrous, filamentary, formed of particles or foamed one layer being a fibrous or filamentary layer impregnated with or embedded in a plastic substance
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/38—Layered products comprising a layer of synthetic resin comprising epoxy resins
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • C08G59/62—Alcohols or phenols
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/24—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs
    • C08J5/249—Impregnating materials with prepolymers which can be polymerised in situ, e.g. manufacture of prepregs characterised by the additives used in the prepolymer mixture
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K3/00—Use of inorganic substances as compounding ingredients
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L61/00—Compositions of condensation polymers of aldehydes or ketones; Compositions of derivatives of such polymers
    • C08L61/04—Condensation polymers of aldehydes or ketones with phenols only
    • C08L61/06—Condensation polymers of aldehydes or ketones with phenols only of aldehydes with phenols
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L63/00—Compositions of epoxy resins; Compositions of derivatives of epoxy resins
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H05K1/03—Use of materials for the substrate

Definitions

  • This disclosure relates to an epoxy resin composition, a resin sheet, a prepreg, a laminate, a method for producing an epoxy resin composition, and a cured body.
  • thermosetting resin composition As an insulating material used in these devices, a cured resin obtained by curing a thermosetting resin composition is widely used from the viewpoint of insulation and heat resistance. However, since the thermal conductivity of the cured resin is generally low and is a major factor hindering heat dissipation, development of a cured resin having high thermal conductivity is desired.
  • a cured product of a composition containing an epoxy resin monomer having a mesogen skeleton in the molecule has been proposed (see, for example, Japanese Patent No. 4118691).
  • the epoxy resin monomer having a mesogen skeleton in the molecule include compounds shown in Japanese Patent No. 4619770, Japanese Patent Application Laid-Open No. 2011-74366, Japanese Patent Application Laid-Open No. 2011-84557, and the like.
  • a technique for achieving high thermal conductivity of the resin cured product there is a method of filling a resin composition with an inorganic filler made of ceramics having high thermal conductivity to make a composite material.
  • ceramics having high thermal conductivity include alumina, boron nitride, aluminum nitride, silica, magnesium oxide, silicon nitride, silicon carbide, and the like.
  • a resin composition containing a so-called mesogen skeleton-containing epoxy resin monomer having a biphenyl skeleton, a phenol resin, and spherical alumina as essential components is disclosed (for example, see Japanese Patent No. 2874089), and heat It is reported that it is a resin composition for semiconductor encapsulation having excellent conductivity. Also disclosed is a resin composition containing an epoxy resin having a biphenyl skeleton, a curing agent having a xanthene skeleton, and an inorganic filler (see, for example, JP-A-2007-262398), and a resin having excellent heat dissipation. It is reported to be a composition.
  • a resin composition containing a tricyclic mesogen skeleton-containing epoxy resin monomer, a curing agent, and alumina powder is disclosed (see, for example, JP-A-2008-13759), and has high thermal conductivity and excellent processing. It is reported to have sex.
  • An epoxy resin monomer having a mesogenic skeleton in the molecule forms a higher order structure having high ordering at the time of curing, which contributes to high thermal conductivity.
  • epoxy resin monomers generally have high crystallinity, even if the epoxy resin composition is heated and melted to be processed or molded to form a semi-cured product, the epoxy resin monomer will return to room temperature. It will recrystallize. When the epoxy resin monomer is recrystallized, the flexibility is lost, and the epoxy resin monomer becomes hard and brittle, making it difficult to handle the semi-cured product.
  • plasticizers such as liquid compounds and elastomers
  • this method impedes the formation of higher-order structures by the plasticizer, it is highly heat conductive. It is difficult to realize the sex.
  • the present invention provides an epoxy resin composition having flexibility even at room temperature and a cured body having high thermal conductivity, a method for producing the same, and a resin sheet, prepreg, and laminate using the epoxy resin composition It is an object to provide a cured product.
  • the present invention includes the following aspects.
  • the oligomer body includes a reaction product of the epoxy resin monomer having the mesogenic skeleton and the novolak resin
  • the weight average molecular weight of the oligomer in the gel permeation chromatography measurement is 1000 to 3000
  • the endothermic peak area in differential scanning calorimetry is 2.5 J / g or less
  • the epoxy resin composition according to ⁇ 1> or ⁇ 2>, wherein the epoxy resin monomer having a mesogenic skeleton includes a compound represented by the following general formula (I-1).
  • the novolak resin contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (II-1) and (II-2) > The epoxy resin composition of any one of>.
  • R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group, and the alkyl group, aryl group, and aralkyl group are substituted. It may have a group.
  • R 22 , R 23 , R 25 , and R 26 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and the alkyl group, aryl group, and aralkyl group each have a substituent. Also good. m21 and m22 each independently represents an integer of 0-2. n21 and n22 each independently represents an integer of 1 to 7. ]
  • the novolak resin contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (III-1) to (III-4) > The epoxy resin composition of any one of>.
  • m31 to m34 and n31 to n34 each independently represent a positive integer.
  • Ar 31 to Ar 34 each independently represent a group represented by the following general formula (III-a) or a group represented by the following general formula (III-b).
  • R 31 and R 34 each independently represents a hydrogen atom or a hydroxyl group.
  • R 32 and R 33 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
  • ⁇ 6> The epoxy resin composition according to any one of ⁇ 1> to ⁇ 5>, wherein the content of the inorganic filler is 60% by volume to 90% by volume.
  • the inorganic filler is at least one particle selected from the group consisting of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, and mica.
  • the epoxy resin composition as described.
  • a resin sheet which is a sheet-like molded body of the epoxy resin composition according to any one of ⁇ 1> to ⁇ 7>.
  • a prepreg having a fiber base and a resin matrix containing the epoxy resin composition according to any one of ⁇ 1> to ⁇ 7>.
  • a substrate From the epoxy resin composition according to any one of ⁇ 1> to ⁇ 7>, the resin sheet according to ⁇ 8>, and the prepreg according to ⁇ 9>, which is disposed on the adherend.
  • a laminate having at least one semi-cured layer selected from the group consisting of a semi-cured layer or a cured layer that is a cured body.
  • a composition containing an epoxy resin monomer having a mesogenic skeleton, a curing agent containing a novolac resin, and an inorganic filler is heat-treated to produce an oligomer of the epoxy resin monomer having the mesogenic skeleton,
  • a method for producing an epoxy resin composition comprising a step of obtaining the epoxy resin composition according to any one of 1> to ⁇ 7>.
  • ⁇ 12> A cured product obtained by curing the epoxy resin composition according to any one of ⁇ 1> to ⁇ 7>, the resin sheet according to ⁇ 8>, or the prepreg according to ⁇ 9>.
  • an epoxy resin composition having flexibility even at room temperature and a cured body having high thermal conductivity, a method for producing the same, and a resin sheet, prepreg, laminate, and curing using the epoxy resin composition The body can be provided.
  • FIG. 3 is a diagram showing a chart of gel permeation chromatography (GPC) measurement in the resin sheet of Example 1.
  • GPC gel permeation chromatography
  • a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
  • the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range.
  • the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.
  • the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition.
  • the term “layer” includes a configuration of a part formed in addition to a configuration of a shape formed on the entire surface when viewed in plan.
  • the term “process” is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term “process” is used if the intended purpose of the process is achieved. included.
  • the epoxy resin composition of the present disclosure includes an epoxy resin monomer having a mesogen skeleton and an oligomer thereof, a curing agent containing a novolac resin, and an inorganic filler, and the oligomer is an epoxy resin having the mesogen skeleton. A reaction product of the monomer and the novolak resin is included.
  • the epoxy resin composition of the present disclosure may further contain other components as necessary.
  • the epoxy resin composition of the present disclosure has a weight average molecular weight of 1000 to 3000 in the above-mentioned oligomer body in gel permeation chromatography (GPC) measurement, and an endothermic peak area in differential scanning calorimetry (DSC) measurement is 2.5 J.
  • the epoxy resin composition of the present disclosure having such a configuration has flexibility even at room temperature (20 ° C. to 30 ° C.), and the cured body has high thermal conductivity.
  • Epoxy resin monomer The epoxy resin composition of the present disclosure contains an epoxy resin monomer having a mesogenic skeleton.
  • An epoxy resin monomer having a mesogenic skeleton tends to form a higher order structure upon curing, and tends to achieve higher thermal conductivity when a cured product of the epoxy resin composition is produced.
  • the mesogenic skeleton refers to a molecular structure that facilitates the expression of crystallinity or liquid crystallinity by the action of intermolecular interaction.
  • Specific examples include a biphenyl skeleton, a phenylbenzoate skeleton, an azobenzene skeleton, a stilbene skeleton, a cyclohexylbenzene skeleton, and derivatives thereof.
  • the higher order structure is a state in which the constituent elements are in a micro array, and corresponds to, for example, a crystal phase and a liquid crystal phase. Whether or not such a higher-order structure exists can be easily determined by observation with a polarizing microscope. That is, when an interference pattern due to depolarization is observed in the observation in the crossed Nicol state, it can be determined that a higher order structure exists.
  • the higher order structure usually exists in an island shape in the resin, and forms a domain structure. Each island forming the domain structure is called a higher-order structure.
  • the structural units constituting the higher order structure are generally bonded by a covalent bond.
  • epoxy resin monomer having a mesogenic skeleton examples include an epoxy resin monomer represented by the following general formula (I) (described in Japanese Patent No. 5471975) and an epoxy resin represented by the following general formula (IV).
  • Monomer described in Japanese Patent No. 4118691
  • epoxy resin monomer represented by the following general formula (V) (described in Japanese Patent No. 4619770 and Japanese Patent Application Laid-Open No. 2008-13759), represented by the following general formula (VI)
  • Epoxy resin monomers described in JP 2010-241797 A
  • epoxy resin monomers represented by the following general formula (VII) described in JP 2011-98952 A
  • R 1 to R 4 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
  • n 4, 6, or 8.
  • Ar 1 to Ar 3 each independently represents a divalent group represented by any one of the following general formulas.
  • R 5 to R 10 each independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.
  • Q 1 and Q 2 each independently represent a linear alkylene group having 1 to 9 carbon atoms, and the methylene group constituting the linear alkylene group is substituted with an alkylene group having 1 to 18 carbon atoms.
  • —O— or —N (R 11 ) — may be inserted between the methylene groups.
  • R 11 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.
  • R 12 each independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.
  • a is an integer of 1 to 8
  • b, e, and g are integers of 1 to 6
  • c is an integer of 1 to 7
  • d and h are integers of 1 to 4
  • f is an integer of 1 to 5.
  • all R 12 groups may represent the same group or different groups.
  • R 13 to R 16 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms
  • R 17 to R 20 are each independently Represents a hydrogen atom, a methyl group, or an alkoxy group having 1 to 3 carbon atoms.
  • YL6121H (manufactured by Mitsubishi Chemical Co., Ltd.) is a specific example of an epoxy resin monomer having a mesogen skeleton.
  • the epoxy resin monomer having a mesogen skeleton has been described above, but the epoxy resin monomer having a mesogen skeleton is not limited to these specific examples.
  • the epoxy resin monomers from the viewpoint that the cured product has high thermal conductivity, the epoxy resin monomer represented by the general formula (I) is preferable, and the epoxy resin represented by the following general formula (I-1) is preferable. A resin monomer is more preferable.
  • the epoxy resin composition of the present disclosure may contain an epoxy resin monomer having no mesogen skeleton.
  • the ratio of the epoxy resin monomer having a mesogenic skeleton is preferably 80% by mass or more, and more preferably 90% by mass or more with respect to the entire epoxy resin monomer.
  • the content of the epoxy resin monomer having a mesogen skeleton in the epoxy resin composition is not particularly limited. From the viewpoint of moldability and the thermal conductivity of the cured product, the content of the epoxy resin monomer having a mesogenic skeleton is preferably 5% by mass to 35% by mass in the epoxy resin composition. % Is more preferable.
  • the epoxy resin composition of this indication contains the hardening
  • the novolac resin is preferably a novolak-modified divalent phenol resin monomer such as catechol, resorcinol, hydroquinone, 1,2-naphthalenediol, 1,3-naphthalenediol.
  • the thermal conductivity of the cured product is improved by using a divalent phenol resin monomer, and the heat resistance of the cured product tends to be further improved by using a novolak form of these compounds.
  • the novolak resin preferably contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (II-1) and (II-2).
  • the proportion of the compound in the entire novolak resin is preferably 70% by mass or more, and more preferably 80% by mass or more.
  • R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group.
  • the alkyl group, aryl group, and aralkyl group represented by R 21 or R 24 may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, a halogen atom, and a hydroxyl group.
  • R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group, and is an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. Preferably, it is an alkyl group having 1 to 6 carbon atoms.
  • n21 and m22 each independently represents an integer of 0-2.
  • m21 and m22 are each independently preferably 0 or 1, and more preferably 0.
  • N21 and n22 each independently represents an integer of 1 to 7, and has a structural unit represented by at least one selected from the group consisting of the general formulas (II-1) and (II-2) The number of the structural unit represented by the general formula (II-1) or the structural unit represented by the general formula (II-2) in the compound is shown.
  • R 22 , R 23 , R 25 , and R 26 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group.
  • the alkyl group, aryl group, and aralkyl group represented by R 22 , R 23 , R 25 , or R 26 may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, a halogen atom, and a hydroxyl group.
  • R 22 , R 23 , R 25 , and R 26 are preferably a hydrogen atom, an alkyl group, or an aryl group from the viewpoint of the storage stability of the epoxy resin composition and the thermal conductivity of the cured product.
  • R 22 , R 23 , R 25 , and R 26 are more preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and more preferably a hydrogen atom. preferable.
  • at least one of R 22 and R 23 or at least one of R 25 and R 26 is an aryl group, and it is an aryl group having 6 to 12 carbon atoms.
  • the aryl group may be a heteroaryl group in which the aromatic group may contain a hetero atom (oxygen atom, nitrogen atom, sulfur atom, etc.), and the total number of hetero atoms and carbon atoms is 6 to 12. It is preferable.
  • the novolak resin may contain one type of compound having the structural unit represented by the general formula (II-1) or the structural unit represented by the general formula (II-2). Two or more types may be included.
  • the novolak resin preferably contains a compound having a structural unit represented by the general formula (II-1) from the viewpoint of thermal conductivity of the cured body, and is represented by the general formula (II-1), It is more preferable to include at least a compound having a structural unit derived from resorcinol.
  • the compound having the structural unit represented by the general formula (II-1) may further include at least one partial structure derived from a phenol resin monomer other than resorcinol.
  • phenol resin monomers other than resorcinol include phenol, cresol, catechol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,3,5-trihydroxybenzene, and the like. Can do.
  • the compound having the structural unit represented by the general formula (II-1) may contain one kind of partial structure derived from these phenol resin monomers, or may contain two or more kinds in combination. Good.
  • the compound represented by the above general formula (II-2) and having a structural unit derived from catechol may further contain at least one partial structure derived from a phenol resin monomer other than catechol.
  • phenol resin monomers other than catechol include phenol, cresol, resorcinol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,3,5-trihydroxybenzene, and the like. Can do.
  • the compound having the structural unit represented by the general formula (II-2) may contain one kind of partial structure derived from these phenol resin monomers, or may contain two or more kinds in combination. Good.
  • the partial structure derived from the phenol resin monomer means a monovalent or divalent group constituted by removing one or two hydrogen atoms from the aromatic ring portion of the phenol resin monomer.
  • the position where the hydrogen atom is removed is not particularly limited.
  • the partial structure derived from the phenol resin monomer other than resorcinol includes the thermal conductivity of the cured product and the adhesiveness and storage of the epoxy resin composition. From the viewpoint of stability, it is selected from the group consisting of phenol, cresol, catechol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene. It is preferably a partial structure derived from at least one kind, and more preferably a partial structure derived from at least one kind selected from catechol and hydroquinone.
  • the content ratio of the partial structure derived from resorcinol is not particularly limited. From the viewpoint of the elastic modulus of the cured product, the content ratio of the partial structure derived from resorcinol to the total mass of the compound having the structural unit represented by the general formula (II-1) is preferably 55% by mass or more. From the viewpoint of the glass transition temperature (Tg) of the epoxy resin and the linear expansion coefficient of the cured product, it is more preferably 60% by mass or more, further preferably 80% by mass or more, and the thermal conductivity of the cured product. From the viewpoint, it is particularly preferably 90% by mass or more.
  • Tg glass transition temperature
  • the molecular weight of the compound having a structural unit represented by at least one selected from the group consisting of the general formulas (II-1) and (II-2) is not particularly limited.
  • the number average molecular weight (Mn) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 350 to 1500.
  • the weight average molecular weight (Mw) is preferably 2000 or less, more preferably 1500 or less, and further preferably 400 to 1500. These Mn and Mw are measured by a usual method using gel permeation chromatography (GPC).
  • the hydroxyl equivalent of the compound having a structural unit represented by at least one selected from the group consisting of the general formulas (II-1) and (II-2) is not particularly limited.
  • the hydroxyl group equivalent is preferably 50 g / eq to 150 g / eq on average, more preferably 50 g / eq to 120 g / eq, and 55 g / eq to 120 g / eq. More preferably, it is eq.
  • the novolak resin preferably contains a compound having a structure represented by at least one selected from the group consisting of the following general formulas (III-1) to (III-4).
  • the proportion of the compound in the entire novolak resin is preferably 70% by mass or more, and more preferably 80% by mass or more.
  • n31 to n34 each independently represent a positive integer.
  • Ar 31 to Ar 34 each independently represent a group represented by the following general formula (III-a) or a group represented by the following general formula (III-b).
  • R 31 and R 34 each independently represent a hydrogen atom or a hydroxyl group.
  • R 32 and R 33 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
  • the compound having a structure represented by at least one selected from the group consisting of the above general formulas (III-1) to (III-4) can be produced by a production method described later in which a divalent phenol resin monomer is novolakized. It can be generated as a by-product.
  • the structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) may be included as a main chain skeleton of the novolak resin, and the novolak It may be contained as part of the side chain of the resin. Furthermore, each structural unit constituting the structure represented by any one of the general formulas (III-1) to (III-4) may be included randomly or regularly. It may be included or may be included in a block shape. In the above general formulas (III-1) to (III-4), the hydroxyl group substitution position is not particularly limited as long as it is on the aromatic ring.
  • a plurality of Ar 31 to Ar 34 may all be the same atomic group, or may contain two or more atomic groups.
  • Ar 31 to Ar 34 each independently represent either a group represented by the general formula (III-a) or a group represented by the general formula (III-b).
  • R 31 and R 34 each independently represents a hydrogen atom or a hydroxyl group, and is preferably a hydroxyl group from the viewpoint of thermal conductivity of the cured product. Further, the substitution positions of R 31 and R 34 are not particularly limited.
  • R 32 and R 33 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
  • alkyl group having 1 to 8 carbon atoms in R 32 and R 33 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl Groups and the like.
  • substitution positions of R 32 and R 33 in the general formulas (III-a) and (III-b) are not particularly limited.
  • Ar 31 to Ar 34 are each independently derived from dihydroxybenzene from the viewpoint of achieving the effects of the present invention, particularly excellent thermal conductivity for the cured product.
  • a group that is, a group in which R 31 is a hydroxyl group and R 32 and R 33 are a hydrogen atom in the above general formula (III-a)
  • a group derived from dihydroxynaphthalene that is, the above general formula (III- It is preferable that at least one selected from R) in which R 34 is a hydroxyl group in b).
  • group derived from dihydroxybenzene means a divalent group formed by removing two hydrogen atoms from the aromatic ring portion of dihydroxybenzene, and the position at which the hydrogen atom is removed is not particularly limited.
  • group derived from dihydroxynaphthalene has the same meaning.
  • Ar 31 to Ar 34 are preferably each independently a group derived from dihydroxybenzene, and derived from 1,2-dihydroxybenzene (catechol). More preferably, it is at least one selected from the group consisting of a group and a group derived from 1,3-dihydroxybenzene (resorcinol). Furthermore, Ar 31 to Ar 34 preferably include at least a group derived from resorcinol from the viewpoint of particularly improving the thermal conductivity of the cured body. Further, from the viewpoint of particularly improving the thermal conductivity of the cured product, the structural unit represented by n31 to n34 preferably contains at least a partial structure derived from resorcinol.
  • the compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) includes a partial structure derived from resorcinol
  • the partial structure derived from resorcinol The content is preferably 55% by mass or more, based on the total mass of the compound having a structure represented by at least one of the general formulas (III-1) to (III-4), and 60% by mass. % Or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.
  • (m + n) is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less from the viewpoint of fluidity of the epoxy resin composition.
  • the lower limit of (m + n) is not particularly limited.
  • the compound having a structure represented by at least one selected from the group consisting of the above general formulas (III-1) to (III-4) is particularly a dihydroxybenzene in which Ar 31 to Ar 34 are substituted or unsubstituted and substituted Alternatively, in the case of at least one of unsubstituted dihydroxynaphthalene, compared to a novolak resin or the like obtained by simply novolacizing these, the synthesis thereof is easy, and a novolak resin having a low softening point tends to be obtained. . Therefore, there exists an advantage that manufacture and handling of the epoxy resin composition containing such a novolak resin as a hardening
  • a compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) is obtained by field desorption ionization mass spectrometry (FD-MS). The above structure can be specified as the fragment component.
  • the molecular weight of the compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) is not particularly limited.
  • the number average molecular weight (Mn) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 350 to 1500.
  • the weight average molecular weight (Mw) is preferably 2000 or less, more preferably 1500 or less, and further preferably 400 to 1500. These Mn and Mw are measured by a usual method using gel permeation chromatography (GPC).
  • the hydroxyl equivalent of the compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) is not particularly limited.
  • the hydroxyl group equivalent is preferably 50 g / eq to 150 g / eq on average, more preferably 50 g / eq to 120 g / eq, and 55 g / eq to 120 g / eq. More preferably, it is eq.
  • the content of the curing agent in the epoxy resin composition is not particularly limited, but is preferably 1% by mass to 15% by mass in the epoxy resin composition from the viewpoint of thermal conductivity of the cured product. More preferably, it is 10 mass%.
  • the ratio of the number of equivalents of phenolic hydroxyl groups in the curing agent and the number of equivalents of epoxy groups in the epoxy resin monomer is preferably 0.5 to 2. More preferably, it is 0.8 to 1.2.
  • the epoxy resin composition of the present disclosure contains an oligomer of an epoxy resin monomer having the mesogen skeleton.
  • the epoxy resin composition of the present disclosure includes a reaction product of the epoxy resin monomer having the mesogen skeleton and the novolak resin as a curing agent as the oligomer. By containing the reactant, the thermal conductivity of the cured body is improved.
  • the oligomer may further contain a homopolymer of an epoxy resin monomer having a mesogen skeleton.
  • the oligomer body has a weight average molecular weight (Mw) of 1000 to 3000 as measured by gel permeation chromatography (GPC).
  • Mw weight average molecular weight
  • the weight average molecular weight (Mw) is more preferably 1200 to 2800, and further preferably 1500 to 2500.
  • the weight average molecular weight (Mw) of the said oligomer body is measured as follows. First, the epoxy resin composition is immersed in tetrahydrofuran (THF) and left for half a day (12 hours). Thereafter, the THF-soluble matter is filtered through a 0.45 ⁇ m membrane filter, and GPC measurement is performed under the measurement conditions described in the Examples described later for the filtrate. And the analysis result which calculated
  • THF tetrahydrofuran
  • the content of the oligomer in the epoxy resin composition is not particularly limited. From the viewpoint of flexibility at normal temperature and the thermal conductivity of the cured product, the content of the oligomer is preferably 1% by mass to 5% by mass in the epoxy resin composition, and 2% by mass to 3.5% by mass. % Is more preferable.
  • the epoxy resin composition of the present disclosure contains at least one inorganic filler.
  • an inorganic filler By containing an inorganic filler, high thermal conductivity can be achieved for the cured body.
  • the inorganic filler may be non-conductive or conductive. By using a non-conductive inorganic filler, it is possible to suppress a decrease in electrical insulation of the cured body. Moreover, the heat conductivity of a hardening body improves more by using a conductive inorganic filler.
  • non-conductive inorganic filler examples include particles of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, mica, silicon oxide, aluminum hydroxide, barium sulfate, and the like.
  • conductive inorganic filler examples include particles such as gold, silver, nickel, copper, and graphite.
  • at least one particle selected from the group consisting of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, and mica is preferable from the viewpoint of thermal conductivity and electrical insulation.
  • Alumina includes ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, ⁇ -alumina, etc., and ⁇ -alumina is preferable from the viewpoint of thermal conductivity.
  • the presence of ⁇ -alumina in the alumina filler can be confirmed by an X-ray diffraction spectrum. Specifically, according to the description in Japanese Patent No. 3759208, the presence of ⁇ -alumina can be confirmed using a peak peculiar to ⁇ -alumina as an index.
  • inorganic fillers can be used in one kind or a mixed system of two or more kinds.
  • an alumina filler and a boron nitride filler can be used in combination, but the combination is not limited to this.
  • the inorganic filler may have a single peak or a plurality of peaks when a particle size distribution curve having a particle diameter on the horizontal axis and a frequency on the vertical axis is drawn. .
  • the filling property of the inorganic filler is improved and the thermal conductivity is improved.
  • the average particle size (D50) which is a particle size corresponding to 50% cumulative from the small particle size side of the weight cumulative particle size distribution of the inorganic filler Is preferably from 0.1 ⁇ m to 100 ⁇ m, more preferably from 0.1 ⁇ m to 50 ⁇ m from the viewpoint of thermal conductivity.
  • a particle size distribution curve can comprise, for example in combination of 2 or more types of inorganic fillers which have a different average particle diameter.
  • the average particle diameter of the inorganic filler is measured using a laser diffraction method, and corresponds to a particle diameter at which the weight accumulation is 50% when the weight accumulation particle size distribution curve is drawn from the small particle diameter side.
  • the particle size distribution measurement using the laser diffraction method can be performed using a laser diffraction scattering particle size distribution measuring device (for example, LS230, manufactured by Beckman Coulter, Inc.).
  • an inorganic filler (A) having an average particle diameter of 10 ⁇ m to 100 ⁇ m and an inorganic filler ( A mixed filler with an inorganic filler (B) which is 1/2 or less of A) and is 0.1 ⁇ m or more and less than 10 ⁇ m can be mentioned.
  • the above mixed filler is based on the total volume of the inorganic filler (100% by volume), the inorganic filler (A) is 60% to 90% by volume, and the inorganic filler (B) is 10% to 40% by volume (however, inorganic
  • the total volume% of the fillers (A) and (B) is preferably 100% by volume).
  • the inorganic filler at this time may be the same or different.
  • both the inorganic fillers (A) and (B) may be alumina fillers
  • the inorganic filler (A) may be an alumina filler
  • the inorganic filler (B) may be a boron nitride filler.
  • a mixed filler is a mixed filler.
  • the above mixed filler is based on the total volume of the inorganic filler (100% by volume), the inorganic filler (A ′) is 30% by volume to 89% by volume, the inorganic filler (B ′) is 10% by volume to 40% by volume, The proportion of the inorganic filler (C ′) is 1% by volume to 30% by volume (provided that the total volume% of the inorganic fillers (A ′), (B ′), and (C ′) is 100% by volume) Is preferred.
  • the inorganic filler at this time may be the same or different.
  • the inorganic fillers (A ′), (B ′), and (C ′) may all be alumina fillers
  • the inorganic filler (A ′) is a boron nitride filler
  • (C ′) may both be alumina fillers.
  • the average particle diameter of the inorganic fillers (A) and (A ′) is the thickness of the cured product in the target resin sheet and the epoxy resin when the epoxy resin composition is applied to a resin sheet described later.
  • the composition is applied to a prepreg described later, it is preferable that the composition is appropriately selected according to the target film thickness of the prepreg and the fineness of the fiber material.
  • the average particle diameter of the inorganic fillers (A) and (A ′) is preferably as large as possible from the viewpoint of thermal conductivity.
  • the film thickness is preferably as thin as possible within the range allowed by electrical insulation. Therefore, the average particle size of the inorganic fillers (A) and (A ′) is preferably 10 ⁇ m to 100 ⁇ m, and from the viewpoint of the filling properties, thermal resistance, and thermal conductivity of the inorganic filler, it is 10 ⁇ m to 80 ⁇ m. Is more preferably 10 ⁇ m to 50 ⁇ m.
  • the content of the inorganic filler in the epoxy resin composition is not particularly limited. From the viewpoint of thermal conductivity and moldability, the content of the inorganic filler is preferably 60% by volume to 90% by volume when the total volume of the epoxy resin composition is 100% by volume, preferably 70% by volume to More preferably, it is 90 volume%. When the content of the inorganic filler is 60% by volume or more, a higher thermal conductivity can be achieved for the cured body, while when it is 90% by volume or less, an epoxy resin composition having excellent moldability. Can be obtained.
  • the content (volume%) of the inorganic filler in the epoxy resin composition can be calculated based on the volume of the epoxy resin composition and the inorganic filler measured by the Archimedes method.
  • the epoxy resin composition of the present disclosure may further include a nanoparticle-sized inorganic filler (for example, an inorganic filler having an average particle diameter of 1 nm to 100 nm) as necessary.
  • a nanoparticle-sized inorganic filler for example, an inorganic filler having an average particle diameter of 1 nm to 100 nm
  • the content of the inorganic filler having an average particle diameter of 1 nm to 100 nm is not particularly limited.
  • the content of the inorganic filler having an average particle diameter of 1 nm to 100 nm is preferably 0.01% by volume to 1% by volume when the total volume of the epoxy resin composition is 100% by volume, More preferably, the volume is from 0.5% to 0.5% by volume.
  • the epoxy resin composition of the present disclosure may further contain a curing accelerator as necessary. By further including a curing accelerator, the epoxy resin composition can be further sufficiently cured.
  • the type and content of the curing accelerator are not particularly limited, and an appropriate type and content can be selected from the viewpoint of reaction rate, reaction temperature, storage property, and the like.
  • Specific examples of the curing accelerator include imidazole compounds, organic phosphorus compounds, tertiary amines, quaternary ammonium salts, and the like. Among these, from the viewpoint of heat resistance, it is preferably at least one selected from the group consisting of an organic phosphine compound and a complex of an organic phosphine compound and an organic boron compound.
  • organic phosphine compound examples include triphenylphosphine, diphenyl (p-tolyl) phosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) phosphine, tris (alkylalkoxyphenyl) phosphine, and tris (dialkylphenyl).
  • Phosphine tris (trialkylphenyl) phosphine, tris (tetraalkylphenyl) phosphine, tris (dialkoxyphenyl) phosphine, tris (trialkoxyphenyl) phosphine, tris (tetraalkoxyphenyl) phosphine, trialkylphosphine, dialkylarylphosphine, Examples thereof include alkyl diaryl phosphine.
  • complexes of organic phosphine compounds and organic boron compounds include tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, tetrabutylphosphonium tetraphenylborate, and tetraphenylphosphonium n-butyl.
  • examples thereof include triphenyl borate, butyl triphenyl phosphonium tetraphenyl borate, and methyl tributyl phosphonium tetraphenyl borate.
  • a hardening accelerator may be used individually by 1 type, and may use 2 or more types together.
  • the method of mixing and using 2 types of hardening accelerators from which the reaction start temperature and reaction rate of an epoxy resin monomer and a novolak resin differ, for example is mentioned.
  • the mixing ratio of the curing accelerators is not particularly limited by the characteristics (for example, how much flexibility is required) required for the epoxy resin composition of the present disclosure. I can decide.
  • the content of the curing accelerator is preferably 0.5% by mass to 1.5% by mass, and preferably 0.5% by mass to 0.5% by mass with respect to the total mass of the epoxy resin monomer and the curing agent.
  • the content is more preferably 1% by mass, and further preferably 0.75% by mass to 1% by mass.
  • the epoxy resin composition of the present disclosure preferably further contains at least one silane coupling agent.
  • silane coupling agent plays the role of forming a covalent bond between the surface of the inorganic filler and the epoxy resin surrounding it (equivalent to the binder agent), and the effect of transferring heat more efficiently, Moreover, the effect of improving the insulation reliability can be obtained by preventing the intrusion of moisture.
  • the type of the silane coupling agent is not particularly limited and can be appropriately selected from commercially available ones. Considering compatibility with epoxy resin monomer and curing agent having mesogenic skeleton and reducing heat conduction deficiency at the interface between epoxy resin and inorganic filler, terminal epoxy group, amino group, mercapto group, ureido group And a silane coupling agent having at least one functional group selected from the group consisting of hydroxyl groups.
  • silane coupling agent examples include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane.
  • Silane coupling agents having an epoxy group such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- Silane coupling agents having an amino group such as (2-aminoethyl) aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercapto G Silane coupling agent having a ureido group such as 3-ureidopropyltriethoxysilane; silane coupling agent having a mercapto group such as silane, and the like. Further, silane coupling agent oligomers (manufactured by Hitachi Chemical Techno Service Co., Ltd.) represented by SC-6000KS2 can
  • the epoxy resin composition of the present disclosure can contain other components as necessary in addition to the above components.
  • examples of other components include a dispersant.
  • examples of the dispersant include Ajinomoto Finetech Co., Ltd. Ajisper series, Enomoto Kasei Co., Ltd. HIPLAAD series, Kao Corporation homogenol series, and the like. These may be used alone or in combination of two or more.
  • the curing reaction between the epoxy resin monomer and the novolak resin as the curing agent partially proceeds.
  • the handleability is improved as compared with a resin sheet made of an epoxy resin composition in which the curing reaction has not progressed.
  • the epoxy resin composition of the present disclosure has an endothermic peak area of 2.0 J / g or less in differential scanning calorimetry (DSC) measurement, and a sample of 4 cm ⁇ 4 cm ⁇ 150 ⁇ m is heated in a thermostat at 190 ° C. for 2 hours.
  • the thermal weight reduction rate is 0.4% by mass or less from the viewpoints of flexibility at normal temperature and high thermal conductivity of the cured body.
  • the differential scanning calorimetry (DSC) measurement of the epoxy resin composition can be performed using, for example, a differential scanning calorimeter manufactured by PerkinElmer.
  • the value obtained by dividing the endothermic peak area of the data obtained by the measurement by the mass of the sample used for the measurement is 2.5 J / g or less, so that an epoxy resin composition having flexibility even at room temperature can be obtained. it can.
  • the endothermic peak area is more preferably 2.3 J / g or less, and further preferably 2.0 J / g or less.
  • the area of the endothermic peak in differential scanning calorimetry (DSC) measurement reflects the amount of crystalline epoxy resin monomer present in the epoxy resin composition. Therefore, if all the epoxy resin monomers are present in a molten state, no endothermic peak is observed. Accordingly, it is particularly preferable that the epoxy resin composition of the present disclosure does not show an endothermic peak (0 J / g). However, if the area of the endothermic peak is 2.5 J / g or less, the epoxy resin composition is sufficiently flexible at room temperature.
  • the thermal weight loss rate is more preferably 0.35% by mass or less, and further preferably 0.3% by mass or less.
  • the thermal weight reduction rate is 0.4% by mass or less.
  • the sample is heated in a thermostat set at 190 ° C. for 2 hours, so that the thermogravimetric reduction rate is comparable when the thickness of the sample is in the range of 100 ⁇ m to 200 ⁇ m. Therefore, the thickness of the sample used for measuring the thermal weight loss rate does not need to be strictly 150 ⁇ m, and may be in the range of 100 ⁇ m to 200 ⁇ m.
  • the epoxy resin composition of the present disclosure has an exothermic peak area in differential scanning calorimetry (DSC) measurement of 12.8 J / g to 20.5 J / g from the viewpoint of flexibility at room temperature and thermal conductivity of the cured body. It is preferable that The exothermic peak in differential scanning calorimetry (DSC) measurement reflects the amount of unreacted epoxy resin monomer and curing agent present in the epoxy resin composition.
  • the differential scanning calorimetry (DSC) measurement of the epoxy resin composition can be performed using, for example, a differential scanning calorimeter manufactured by PerkinElmer.
  • the value obtained by dividing the exothermic peak area of the data obtained by the measurement by the mass of the sample used for the measurement is 12.8 J / g to 20.5 J / g. It is preferable from the viewpoint of thermal conductivity.
  • the exothermic peak area is more preferably 12.8 J / g to 20.0 J / g, and further preferably 12.8 J / g to 19.2 J / g.
  • the method for producing an epoxy resin composition of the present disclosure includes a heat treatment of a composition (for example, a resin varnish) containing an epoxy resin monomer having a mesogenic skeleton, a curing agent containing a novolac resin, and an inorganic filler, and the mesogenic skeleton.
  • a step of producing an epoxy resin composition by producing an oligomer of an epoxy resin monomer having a cation.
  • the oligomer body includes a reaction product of an epoxy resin monomer having a mesogenic skeleton and a novolac resin.
  • the epoxy resin monomer having a mesogen skeleton contained in a composition before heat treatment is an epoxy resin monomer having a mesogen skeleton contained in the epoxy resin composition of the present disclosure.
  • the same can be used.
  • the content rate of the epoxy resin monomer having a mesogen skeleton in the unheat-treated composition is not particularly limited. From the viewpoint of moldability and thermal conductivity of the cured body, the content of the epoxy resin monomer having a mesogenic skeleton is preferably 5% by mass to 35% by mass in the solid content of the unheat-treated composition. % To 25% by mass is more preferable.
  • the curing agent containing the novolak resin contained in the unheat-treated composition may be the same as the curing agent contained in the epoxy resin composition of the present disclosure.
  • the content of the curing agent in the unheat-treated composition is not particularly limited. From the viewpoint of the thermal conductivity of the cured body, the content of the curing agent is preferably 1% by mass to 15% by mass in the solid content of the unheat-treated composition, and preferably 1% by mass to 10% by mass. Is more preferable.
  • the ratio of the number of equivalents of phenolic hydroxyl groups in the curing agent and the number of equivalents of epoxy groups in the epoxy resin monomer is preferably 0.5 to 2. More preferably, it is 0.8 to 1.2.
  • the curing agent may contain a phenol resin monomer that constitutes a novolac resin.
  • a content ratio (henceforth "monomer content ratio") of the phenol resin monomer which comprises the novolak resin in the said hardening
  • the monomer content is preferably 10% by mass to 80% by mass, and more preferably 15% by mass to 60% by mass. More preferably, it is 20 mass% or more and 50 mass% or less.
  • the monomer content is 80% by mass or less, the amount of monomers that do not contribute to crosslinking during the curing reaction is reduced and the number of crosslinked high molecular weight substances is increased, so that a higher-order higher-order structure is formed and heat conduction is increased. Tend to improve.
  • the monomer content ratio is 10% by mass or more, the epoxy resin easily flows during molding, so the adhesion between the inorganic filler and the epoxy resin is further improved, and more excellent thermal conductivity and heat resistance. Tends to be achieved.
  • the inorganic filler contained in the unheat-treated composition may be the same as the inorganic filler contained in the epoxy resin composition of the present disclosure.
  • the content of the inorganic filler in the unheat-treated composition is not particularly limited. From the viewpoint of thermal conductivity and moldability, the content of the inorganic filler is preferably 60% by volume to 90% by volume when the volume of the total solid content of the unheat-treated composition is 100% by volume, More preferably, it is 70 to 90% by volume. When the content of the inorganic filler is 60% by volume or more, it tends to be able to achieve higher thermal conductivity for the cured body, while the content of the inorganic filler is 90% by volume or less. There exists a tendency which can obtain the epoxy resin composition excellent in the moldability.
  • the unheat-treated composition may further contain other components such as a curing accelerator, a silane coupling agent, and a dispersant.
  • the unheated composition preferably further contains at least one organic solvent.
  • the organic solvent can be appropriately selected from commonly used organic solvents. Specific examples include alcohol solvents, ether solvents, ketone solvents, amide solvents, aromatic hydrocarbon solvents, ester solvents, nitrile solvents, sulfoxide solvents, and the like.
  • organic solvents include ketone solvents such as methyl isobutyl ketone, cyclohexanone, and methyl ethyl ketone; amide solvents such as dimethylacetamide, dimethylformamide, and N-methyl-2-pyrrolidone; ester solvents such as ⁇ -butyrolactone; dimethyl sulfoxide, sulfolane And the like can be used. These may be used alone or in combination of two or more.
  • the method for heat-treating the unheated composition is not particularly limited, and examples thereof include a method of heating at 80 to 180 ° C. for 1 to 30 minutes.
  • This heat treatment may be a one-step process based on one kind of temperature condition or a multi-stage process based on a plurality of kinds of temperature conditions.
  • the semi-cured product of the epoxy resin composition is obtained by semi-curing the epoxy resin composition of the present disclosure.
  • the semi-cured product of the epoxy resin composition has a viscosity of 10 4 Pa ⁇ s to 10 5 Pa ⁇ s at room temperature, but is 10 2 Pa ⁇ s to 10 3 Pa ⁇ s at 100 ° C. It has a characteristic of decreasing.
  • the viscosity is measured by dynamic viscoelasticity measurement (DMA) (for example, ARES-2KSTD manufactured by TA Instruments).
  • DMA dynamic viscoelasticity measurement
  • the measurement conditions are a frequency of 1 Hz, a load of 40 g, a heating rate of 3 ° C./min, and a shear test is performed.
  • the method of the semi-curing treatment is not particularly limited, and examples thereof include a method of heating at 100 ° C. to 200 ° C. for 1 minute to 30 minutes.
  • the cured product of the epoxy resin composition is obtained by curing the epoxy resin composition of the present disclosure.
  • This cured product is excellent in thermal conductivity. This is considered to be because, for example, an epoxy resin monomer having a mesogen skeleton contained in the epoxy resin composition forms a higher order structure centering on an inorganic filler.
  • the method of the curing treatment can be appropriately selected according to the configuration of the epoxy resin composition, the purpose of the cured body, etc., and is preferably heating and pressure treatment.
  • the epoxy resin composition of the present disclosure is pressurized at 1 to 20 MPa at 100 to 250 ° C. for 30 minutes to 8 hours, preferably 1 to 15 MPa at 130 to 230 ° C. for 30 minutes to 6 minutes.
  • a cured product is obtained by heating for a period of time.
  • the resin sheet of the present disclosure is a sheet-like molded body of the epoxy resin composition of the present disclosure, and further includes a release film as necessary.
  • the resin sheet of the present disclosure has flexibility at room temperature, and the cured body has excellent thermal conductivity.
  • the density of the resin sheet of the present disclosure is not particularly limited, and can be, for example, 3.0 g / cm 3 to 3.5 g / cm 3 . In consideration of both the flexibility of the resin sheet and the thermal conductivity of the cured body, 3.1 g / cm 3 to 3.4 g / cm 3 is preferable, and 3.1 g / cm 3 to 3.3 g / cm 3 is more preferable. preferable.
  • the density of the resin sheet can be adjusted, for example, by appropriately selecting the content of the inorganic filler in the epoxy resin composition.
  • the thickness of the resin sheet of the present disclosure is not particularly limited and can be appropriately selected depending on the purpose.
  • the thickness may be 50 ⁇ m to 500 ⁇ m, and is preferably 100 ⁇ m to 300 ⁇ m from the viewpoint of thermal conductivity and electrical insulation.
  • the resin sheet of the present disclosure can be produced by applying the unheated composition containing an organic solvent on a release film such as a PET (polyethylene terephthalate) film to form a coating layer and heat-treating it. .
  • a release film such as a PET (polyethylene terephthalate) film
  • the application of the unheat-treated composition can be performed by a known method. Specific examples include methods such as comma coating, die coating, lip coating, and gravure coating. Examples of a coating method for forming a coating layer with a predetermined thickness include a comma coating method in which an object to be coated is passed between gaps, and a die coating method in which the unheated composition with a flow rate adjusted from a nozzle is coated. . For example, when the thickness of the coating layer before heat treatment is 50 ⁇ m to 500 ⁇ m, it is preferable to use a comma coating method.
  • the reaction with the epoxy resin monomer hardly progresses, and the epoxy resin monomer exists in a substantially crystalline state.
  • the sheet before heat treatment has flexibility, it is poor in flexibility, and in the state where the release film as a support is removed, it is poor in self-supporting and difficult to handle.
  • the epoxy resin monomer is recrystallized at room temperature, the semi-cured sheet that has been heat-treated until the coating layer is in a semi-cured state (B-stage state) is poor in flexibility.
  • the resin sheet of the present disclosure is composed of the epoxy resin composition of the present disclosure, so that it has flexibility even at room temperature and is excellent in flexibility and usable time as a resin sheet.
  • the heat treatment method is not particularly limited as long as it satisfies the characteristics required for the epoxy resin composition of the present disclosure, and can be appropriately selected. For example, a method of heating at 80 to 180 ° C. for 1 to 30 minutes can be mentioned.
  • the prepreg of the present disclosure includes a fiber base material and a resin matrix including the epoxy resin composition of the present disclosure. With such a configuration, a prepreg having excellent thermal conductivity is obtained. Moreover, since the said non-heat-treatment composition containing an inorganic filler has high thixotropy, sedimentation of the inorganic filler in the below-mentioned coating process or impregnation process can be suppressed. Therefore, it is possible to suppress the occurrence of the density distribution of the inorganic filler in the thickness direction of the prepreg, and as a result, a prepreg excellent in thermal conductivity is obtained.
  • the fiber base material constituting the prepreg is not particularly limited as long as it is usually used when producing a metal foil-clad laminate or a multilayer wiring board, and is appropriately selected from fiber base materials such as woven fabrics and nonwoven fabrics that are usually used. Selected.
  • the opening of the fiber base material is not particularly limited. From the viewpoint of thermal conductivity and electrical insulation, the mesh opening is preferably 5 times or more the average particle diameter (D50) of the inorganic filler. In addition, when the particle size distribution curve of the inorganic filler has a plurality of peaks, it is more preferable that the opening be 5 times or more the particle diameter corresponding to the peak having the largest particle diameter.
  • the material of the fiber base is not particularly limited. Specifically, inorganic fibers such as glass, alumina, boron, silica alumina glass, silica glass, tyranno, silicon carbide, silicon nitride, zirconia, carbon, aramid, polyetheretherketone, polyetherimide, polyether Examples thereof include organic fibers such as sulfone and cellulose, and mixed papers thereof.
  • a glass fiber woven fabric is preferably used as the fiber base material.
  • a wiring board is configured using prepreg, a wiring board that is flexible and can be arbitrarily bent can be obtained. Furthermore, it becomes possible to reduce the dimensional change of the wiring board accompanying the temperature change, moisture absorption, etc. in the manufacturing process.
  • the thickness of the fiber base material is not particularly limited. From the viewpoint of imparting better flexibility, it is preferably 30 ⁇ m or less, and more preferably 15 ⁇ m or less from the viewpoint of impregnation. Although the minimum of the thickness of a fiber base material is not restrict
  • the mass ratio of the epoxy resin composition in the prepreg of the present disclosure is preferably 50% by mass to 99.9% by mass in the total mass of the prepreg.
  • the prepreg of the present disclosure can be manufactured by coating or impregnating a fiber base material with the unheated composition containing an organic solvent, followed by heat treatment.
  • the heat treatment By the heat treatment, the curing reaction of the resin varnish partially proceeds to form a resin matrix containing the epoxy resin composition.
  • the heat treatment method is not particularly limited as long as it satisfies the characteristics required for the epoxy resin composition of the present disclosure, and can be appropriately selected. For example, a method of heating at 80 to 180 ° C. for 1 to 30 minutes can be mentioned.
  • the method for coating or impregnating the fiber base with the unheated composition there is no particular limitation on the method for coating or impregnating the fiber base with the unheated composition.
  • coating with a coating machine can be mentioned.
  • a vertical coating method in which the fiber base material is pulled through the unheated composition, a horizontal coating method in which the fiber base material is pressed and impregnated after the unheated composition is coated on a support film, etc. can be mentioned. From the viewpoint of suppressing the uneven distribution of the inorganic filler in the fiber base material, the horizontal coating method is suitable.
  • the prepreg of the present disclosure may be used after the surface is smoothed in advance by hot pressing with a press, a roll laminator or the like before being laminated or stuck on the adherend.
  • the hot heat treatment method include a hot vacuum press and a hot roll laminate.
  • the surface of the prepreg is smoothed by heating and pressurizing under reduced pressure (eg, 1 kPa) at 100 to 200 ° C. for 1 minute to 5 minutes with a press pressure of 1 MPa to 20 MPa. be able to.
  • the laminate of the present disclosure includes an adherend and a semi-cured layer or a cured layer disposed on the adherend.
  • the semi-cured layer is at least one semi-cured body selected from the group consisting of the epoxy resin composition of the present disclosure, the resin sheet of the present disclosure, and the prepreg of the present disclosure, and the cured layer is the semi-cured layer. Is cured. By having a semi-hardened layer or a hardened layer, it becomes a laminated board excellent in thermal conductivity.
  • adherend examples include metal foil and metal plate.
  • the adherend may be attached to only one side of the semi-cured layer or the cured layer, or may be attached to both sides.
  • the metal foil is not particularly limited and can be appropriately selected from commonly used metal foils. Specifically, gold foil, copper foil, aluminum foil, etc. can be mentioned, and copper foil is generally used.
  • the thickness of the metal foil is not particularly limited as long as it is 1 ⁇ m to 200 ⁇ m, and a suitable thickness can be selected according to the purpose of use.
  • metal foil nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and a copper layer of 0.5 ⁇ m to 15 ⁇ m and 10 ⁇ m to A composite foil having a three-layer structure provided with a 150 ⁇ m copper layer, or a two-layer structure composite foil in which aluminum and a copper foil are combined can also be used.
  • the metal plate is not particularly limited, but is preferably made of a metal material having high thermal conductivity and a large heat capacity. Specific examples include copper, aluminum, iron, alloys used for lead frames, and the like.
  • the thickness of the metal plate can be appropriately selected according to the application.
  • the metal plate can be selected according to the purpose, such as aluminum when weight reduction or workability is prioritized or copper when heat dissipation is prioritized.
  • the semi-cured layer may have one layer derived from any one of the epoxy resin composition of the present disclosure, the resin sheet of the present disclosure, or the prepreg of the present disclosure.
  • stacked may be sufficient.
  • the form having two or more layers containing the semi-cured body of the epoxy resin composition, the form having two or more semi-cured bodies of the resin sheet, and the semi-cured body of the prepreg 2 Any form having at least one sheet may be used.
  • the laminated board of this indication provides the epoxy resin composition of this indication on a to-be-adhered material, for example, forms an application layer, heats and pressurizes this, and makes an epoxy resin composition semi-harden or harden
  • a laminate of the resin sheet of the present disclosure or the prepreg of the present disclosure is prepared on an adherend, and the resin sheet or the prepreg is semi-cured or cured by heating and pressurizing the adherend, and is adhered to the adherend. It is obtained with.
  • the method of semi-curing treatment or curing treatment is not particularly limited.
  • heat treatment and pressure treatment are preferable.
  • the heating temperature in the heating and pressure treatment is not particularly limited. Usually, it is in the range of 100 ° C to 250 ° C, preferably in the range of 130 ° C to 230 ° C.
  • the pressurization conditions in a heating and pressurizing process are not specifically limited. Usually, it is in the range of 1 MPa to 20 MPa, preferably in the range of 1 MPa to 15 MPa.
  • a vacuum press is used suitably for a heating and pressurizing process.
  • the thickness of the laminate of the present disclosure is preferably 500 ⁇ m or less, and more preferably 100 ⁇ m to 300 ⁇ m.
  • the thickness is 500 ⁇ m or less, the flexibility is excellent, and cracks tend to be suppressed during bending, and when the thickness is 300 ⁇ m or less, the tendency is further observed. Further, when the thickness is 100 ⁇ m or more, the workability tends to be excellent.
  • the cured body of the present disclosure is obtained by curing the epoxy resin composition of the present disclosure, the resin sheet of the present disclosure, or the prepreg of the present disclosure.
  • This cured product is excellent in thermal conductivity. This is considered to be because, for example, an epoxy resin monomer having a mesogenic skeleton and its oligomer form a higher order structure centering on an inorganic filler.
  • the method for the curing treatment is not particularly limited.
  • heat treatment and pressure treatment are preferable.
  • the heating temperature in the heating and pressure treatment is not particularly limited. Usually, it is in the range of 100 ° C to 250 ° C, preferably in the range of 130 ° C to 230 ° C.
  • the pressurization conditions in a heating and pressurizing process are not specifically limited. Usually, it is in the range of 1 MPa to 20 MPa, preferably in the range of 1 MPa to 15 MPa.
  • a vacuum press is used suitably for a heating and pressurizing process.
  • Resin monomer B [refer to Japanese Patent No. 4619770, epoxy equivalent: 201 g / eq]
  • Resin monomer D bisphenol A type epoxy resin monomer, 828 (Mitsubishi Chemical Corporation), epoxy equivalent: about 190 g / eq]
  • Mn and Mw were measured as follows.
  • Mn and Mw were measured using a high performance liquid chromatography L6000 manufactured by Hitachi, Ltd. and a data analyzer C-R4A manufactured by Shimadzu Corporation.
  • G2000HXL and G3000HXL manufactured by Tosoh Corporation were used as analytical GPC columns.
  • the sample concentration was 0.2%, tetrahydrofuran was used as the mobile phase, and the measurement was performed at a flow rate of 1.0 mL / min.
  • a calibration curve was prepared using a polystyrene standard sample, and Mn and Mw were calculated using polystyrene conversion values.
  • the measurement of the hydroxyl equivalent was performed as follows.
  • the hydroxyl equivalent was measured by acetyl chloride-potassium hydroxide titration method.
  • the determination of the titration end point was performed by potentiometric titration instead of the coloring method using an indicator because the solution color was dark.
  • the hydroxyl group of the measurement resin is acetylated in a pyridine solution, the excess reagent is decomposed with water, and the resulting acetic acid is titrated with a potassium hydroxide / methanol solution.
  • TPP Triphenylphosphine [curing accelerator]
  • KBM-573 3-phenylaminopropyltrimethoxysilane [Silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.]
  • PET film [Purex (registered trademark) A53 (manufactured by Teijin DuPont Films Ltd.), 50 ⁇ m thickness] Copper foil [GTS grade (Furukawa Electric Co., Ltd.), 105 ⁇ m thickness]
  • the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
  • FIG. 2A shows a differential scanning calorimetry (DSC) measurement chart and an endothermic peak area calculation portion.
  • the horizontal axis of FIG. 2A indicates temperature (° C.), and the vertical axis indicates heat flow (W / g) per unit mass.
  • FIG. 2B shows a differential scanning calorimetry (DSC) measurement chart and an exothermic peak area calculation part.
  • the horizontal axis of FIG. 2B indicates temperature (° C.), and the vertical axis indicates heat flow (W / g) per unit mass.
  • the copper foil of the cured body 1 obtained above was removed by etching to obtain a resin sheet type cured body 1.
  • the obtained cured body 1 was cut into a 10 mm square and blackened with a graphite spray, and then the thermal diffusivity was evaluated using a xenon flash method (manufactured by NETZSCH, LFA447 nanoflash).
  • the thermal conductivity of the cured body 1 was determined from the product of this value and the specific heat measured with a differential scanning calorie (DSC) measuring device (Pyris 1 manufactured by Perkin Elmer Co., Ltd.) and the density measured by the Archimedes method. As a result, the thermal conductivity of the cured body 1 was 10.0 W / (m ⁇ K).
  • Example 2 A resin varnish 2 was prepared in the same manner as in Example 1, and the resin sheet 2 and the cured body 2 were prepared in substantially the same manner in the other steps, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
  • Example 3 A resin varnish 3 was prepared in the same manner as in Example 1, and the resin sheet 3 and the cured body 3 were prepared in substantially the same manner in the other steps, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
  • Example 4 Epoxy resin monomer (resin monomer B) 5.83 parts, curing agent (CRN) 3.77 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 parts of silane coupling agent (KBM-573), and 17.41 parts of solvent meter (MEK: 14.47 parts, CHN) : 2.94 parts) to obtain a resin varnish 4.
  • resin monomer B 5.83 parts, curing agent (CRN) 3.77 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 parts of silane coupling agent (KBM-573), and 17.41 parts of solvent meter (MEK: 14.47 parts, CHN) : 2.94 parts) to obtain a resin varnish 4.
  • the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
  • Resin sheet 4 and cured body 4 were prepared in the same manner as in Example 1 except that the resin varnish 4 obtained above was used, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
  • Epoxy resin monomer (resin monomer C) 5.63 parts, curing agent (CRN) 4.18 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 part of silane coupling agent (KBM-573), and 17.20 parts of solvent meter (MEK: 14.47 parts, CHN) : 2.73 parts) to obtain a resin varnish 5.
  • the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
  • Resin sheet 5 and cured body 5 were prepared in the same manner as in Example 1 except that the resin varnish 5 obtained above was used, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
  • Example 6 7.69 parts of epoxy resin monomer (resin monomer A), 4.48 parts of curing agent (CRN), 0.08 part of curing accelerator (TPP), a total of 54.16 parts of inorganic filler (HP-40: 28.03 parts) , AA-3: 18.44 parts, AA-04: 7.69 parts), 0.08 part of a silane coupling agent (KBM-573), and 33.51 parts of a solvent (CHN) were mixed to obtain resin varnish 6 Got.
  • epoxy resin monomer (resin monomer A)
  • CCN curing agent
  • TPP curing accelerator
  • HP-40 28.03 parts
  • AA-3 18.44 parts
  • AA-04 7.69 parts
  • KBM-573 silane coupling agent
  • CHN solvent
  • the density of the boron nitride filler is 2.20 / cm 3
  • the density of the ⁇ -alumina filler is 3.98 g / cm 3
  • the density of the mixture of the resin monomer A and CRN is 1.20 g / cm 3.
  • the ratio of the inorganic filler (boron nitride filler and ⁇ -alumina filler) to the volume was calculated to be 70% by volume.
  • the vacuum press conditions (temperature: 150 ° C., degree of vacuum: 1 kPa, press pressure: 15 MPa, processing time: 1 minute) at the time of bonding the semi-cured body 6, and the vacuum when the copper foil is pressure-bonded Resin sheet 6 and cured body 6 were produced in the same manner as in Example 1 except for the press conditions (temperature: 180 ° C., vacuum: 1 kPa, press pressure: 15 MPa, treatment time: 5 minutes). Evaluation was performed in the same manner. The results are shown in Table 1.
  • Resin varnish 9 was prepared in the same manner as in Example 1, and after the application of the resin varnish, in an environment in which volatile components such as solvents are difficult to volatilize, heat treatment was also performed for drying at 120 ° C. for 10 minutes and 150 ° C. for 3 minutes.
  • a resin sheet 9 and a cured product 9 were produced in the same manner as in Example 1 except that the evaluation was performed and evaluated in the same manner as in Example 1. The results are shown in Table 2.
  • the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
  • the resin sheet 10 and the cured body 10 were produced in the same manner as in Example 1 except that the resin varnish 10 obtained above was used, and evaluated in the same manner as in Example 1. The results are shown in Table 2.
  • the resin sheets of Examples 1 to 6 were excellent in flexibility at room temperature, and the cured body had high thermal conductivity.
  • the resin sheets of Comparative Examples 1 and 5 in which the weight-average molecular weight of the oligomer is over 3000 and the resin sheet of Comparative Example 2 in which the endothermic peak area is over 2.5 J / g are room temperature. It was inferior in flexibility.
  • the cured product of Comparative Example 3 in which the thermal weight reduction rate of the resin sheet was more than 0.4% by mass and the cured product of Comparative Example 4 that did not use the epoxy resin monomer having a mesogen skeleton had a thermal conductivity. It was low.

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Abstract

An epoxy resin composition which comprises an epoxy resin monomer having a mesogen skeleton, an oligomer thereof, a hardener comprising a novolak resin, and an inorganic filler, wherein the oligomer includes a product of the reaction of the epoxy resin monomer having a mesogen skeleton with the novolak resin, the oligomer has a weight-average molecular weight, as measured by gel permeation chromatography, of 1,000-3,000, the endothermic peak area as determined by differential scanning calorimetry is 2.5 J/g or less, and when a sample thereof having a size of 4 cm × 4 cm × 150 µm is heated for 2 hours in a 190ºC thermostatic chamber, then the weight loss on heating is 0.4 mass% or less.

Description

エポキシ樹脂組成物、樹脂シート、プリプレグ、積層板、エポキシ樹脂組成物の製造方法、及び硬化体Epoxy resin composition, resin sheet, prepreg, laminate, method for producing epoxy resin composition, and cured body
　本開示は、エポキシ樹脂組成物、樹脂シート、プリプレグ、積層板、エポキシ樹脂組成物の製造方法、及び硬化体に関する。 This disclosure relates to an epoxy resin composition, a resin sheet, a prepreg, a laminate, a method for producing an epoxy resin composition, and a cured body.
　発電機、モーターからプリント配線板、ＩＣ（Integrated Circuit）チップに至るまでの電子機器及び電気機器の多くは、電気を通すための導体と絶縁材料とを含んで構成される。近年、これらの機器の小型化に伴って発熱量が増大している。このため、絶縁材料においていかに熱を放散させるかが重要な課題となっている。 Many electronic devices and electrical devices ranging from generators and motors to printed wiring boards and integrated circuit (IC) chips are composed of a conductor for conducting electricity and an insulating material. In recent years, the amount of heat generated has increased with the miniaturization of these devices. For this reason, how to dissipate heat in the insulating material is an important issue.
　これらの機器に用いられている絶縁材料としては、絶縁性、耐熱性等の観点から、熱硬化性樹脂組成物を硬化して得られる樹脂硬化物が広く使われている。しかし、一般的に樹脂硬化物の熱伝導率は低く、熱放散を妨げている大きな要因となっているため、高熱伝導性を有する樹脂硬化物の開発が望まれている。 As an insulating material used in these devices, a cured resin obtained by curing a thermosetting resin composition is widely used from the viewpoint of insulation and heat resistance. However, since the thermal conductivity of the cured resin is generally low and is a major factor hindering heat dissipation, development of a cured resin having high thermal conductivity is desired.
　高熱伝導性を有する樹脂硬化物として、分子中にメソゲン骨格を有するエポキシ樹脂モノマーを含有する組成物の硬化物が提案されている（例えば、特許第４１１８６９１号公報参照）。分子中にメソゲン骨格を有するエポキシ樹脂モノマーとしては、特許第４６１９７７０号公報、特開２０１１－７４３６６号公報、特開２０１１－８４５５７号公報等に示されている化合物を挙げることができる。 As a resin cured product having high thermal conductivity, a cured product of a composition containing an epoxy resin monomer having a mesogen skeleton in the molecule has been proposed (see, for example, Japanese Patent No. 4118691). Examples of the epoxy resin monomer having a mesogen skeleton in the molecule include compounds shown in Japanese Patent No. 4619770, Japanese Patent Application Laid-Open No. 2011-74366, Japanese Patent Application Laid-Open No. 2011-84557, and the like.
　また、樹脂硬化物の高熱伝導化を達成する手法として、高い熱伝導率を有するセラミックスからなる無機フィラーを樹脂組成物に充填し、コンポジット材料とする方法がある。高い熱伝導率を有するセラミックスとしては、アルミナ、窒化ホウ素、窒化アルミニウム、シリカ、酸化マグネシウム、窒化ケイ素、炭化ケイ素等が知られている。高熱伝導性と電気絶縁性とを両立する無機フィラーを樹脂組成物に充填することにより、コンポジット材料において高熱伝導性と電気絶縁性との両立を図ることができる。 Also, as a technique for achieving high thermal conductivity of the resin cured product, there is a method of filling a resin composition with an inorganic filler made of ceramics having high thermal conductivity to make a composite material. Known ceramics having high thermal conductivity include alumina, boron nitride, aluminum nitride, silica, magnesium oxide, silicon nitride, silicon carbide, and the like. By filling the resin composition with an inorganic filler that achieves both high thermal conductivity and electrical insulation, it is possible to achieve both high thermal conductivity and electrical insulation in the composite material.
　上記に関連し、ビフェニル骨格を有する、いわゆるメソゲン骨格含有エポキシ樹脂モノマーと、フェノール樹脂と、球状アルミナと、を必須成分とする樹脂組成物が開示され（例えば、特許第２８７４０８９号公報参照）、熱伝導性に優れた半導体封止用樹脂組成物であると報告されている。また、ビフェニル骨格を有するエポキシ樹脂と、キサンテン骨格を有する硬化剤と、無機充填材と、を含有する樹脂組成物が開示され（例えば、特開２００７－２６２３９８号公報参照）、放熱性に優れる樹脂組成物であると報告されている。さらに、３環型メソゲン骨格含有エポキシ樹脂モノマーと、硬化剤と、アルミナ粉末と、を含有する樹脂組成物が開示され（例えば、特開２００８－１３７５９号公報参照）、高熱伝導性及び優れた加工性を有すると報告されている。 In relation to the above, a resin composition containing a so-called mesogen skeleton-containing epoxy resin monomer having a biphenyl skeleton, a phenol resin, and spherical alumina as essential components is disclosed (for example, see Japanese Patent No. 2874089), and heat It is reported that it is a resin composition for semiconductor encapsulation having excellent conductivity. Also disclosed is a resin composition containing an epoxy resin having a biphenyl skeleton, a curing agent having a xanthene skeleton, and an inorganic filler (see, for example, JP-A-2007-262398), and a resin having excellent heat dissipation. It is reported to be a composition. Further, a resin composition containing a tricyclic mesogen skeleton-containing epoxy resin monomer, a curing agent, and alumina powder is disclosed (see, for example, JP-A-2008-13759), and has high thermal conductivity and excellent processing. It is reported to have sex.
　分子中にメソゲン骨格を有するエポキシ樹脂モノマーは、硬化時に高い秩序性を有する高次構造を形成し、これが高熱伝導性に寄与している。しかし、このようなエポキシ樹脂モノマーは一般的に結晶性が高いため、加工又は成形を行うためにエポキシ樹脂組成物を加熱して溶融させて半硬化体としても、常温に戻るとエポキシ樹脂モノマーが再結晶化してしまう。エポキシ樹脂モノマーが再結晶化すると、柔軟性が失われ、硬く脆いものとなってしまうため、半硬化体の取り扱いが困難となっている。 An epoxy resin monomer having a mesogenic skeleton in the molecule forms a higher order structure having high ordering at the time of curing, which contributes to high thermal conductivity. However, since such epoxy resin monomers generally have high crystallinity, even if the epoxy resin composition is heated and melted to be processed or molded to form a semi-cured product, the epoxy resin monomer will return to room temperature. It will recrystallize. When the epoxy resin monomer is recrystallized, the flexibility is lost, and the epoxy resin monomer becomes hard and brittle, making it difficult to handle the semi-cured product.
　また、柔軟性を付与するためには、液状化合物、エラストマー等の可塑剤を添加することが一般的であるが、この手法では可塑剤により高次構造の形成が阻害されてしまうため、高熱伝導性を実現することが困難である。 In order to impart flexibility, it is common to add plasticizers such as liquid compounds and elastomers, but since this method impedes the formation of higher-order structures by the plasticizer, it is highly heat conductive. It is difficult to realize the sex.
　本発明は、上記課題に鑑み、常温でも柔軟性を有し、かつ硬化体が高熱伝導性を有するエポキシ樹脂組成物及びその製造方法、並びにこのエポキシ樹脂組成物を用いる樹脂シート、プリプレグ、積層板、及び硬化体を提供することを課題とする。 In view of the above problems, the present invention provides an epoxy resin composition having flexibility even at room temperature and a cured body having high thermal conductivity, a method for producing the same, and a resin sheet, prepreg, and laminate using the epoxy resin composition It is an object to provide a cured product.
　本発明者らは、上記課題を解決するために鋭意検討した結果、本発明に至った。すなわち、本発明は以下の態様を包含する。 As a result of intensive studies to solve the above problems, the present inventors have arrived at the present invention. That is, the present invention includes the following aspects.
＜１＞　メソゲン骨格を有するエポキシ樹脂モノマー及びそのオリゴマー体と、ノボラック樹脂を含む硬化剤と、無機フィラーと、を含有し、
　前記オリゴマー体は、前記メソゲン骨格を有するエポキシ樹脂モノマーと前記ノボラック樹脂との反応物を含み、
　ゲルパーミエーションクロマトグラフィー測定における前記オリゴマー体の重量平均分子量が１０００～３０００であり、
　示差走査熱量測定における吸熱ピーク面積が２．５Ｊ／ｇ以下であり、
　４ｃｍ×４ｃｍ×１５０μｍのサンプルを１９０℃の恒温槽で２時間加熱したときの熱重量減少率が０．４質量％以下であるエポキシ樹脂組成物。 <1> an epoxy resin monomer having a mesogenic skeleton and an oligomer thereof, a curing agent containing a novolac resin, and an inorganic filler,
The oligomer body includes a reaction product of the epoxy resin monomer having the mesogenic skeleton and the novolak resin,
The weight average molecular weight of the oligomer in the gel permeation chromatography measurement is 1000 to 3000,
The endothermic peak area in differential scanning calorimetry is 2.5 J / g or less,
An epoxy resin composition having a thermal weight loss rate of 0.4% by mass or less when a sample of 4 cm × 4 cm × 150 μm is heated in a thermostat at 190 ° C. for 2 hours.
＜２＞　示差走査熱量測定における発熱ピーク面積が１２．８Ｊ／ｇ～２０．５Ｊ／ｇである前記＜１＞に記載のエポキシ樹脂組成物。 <2> The epoxy resin composition according to <1>, wherein an exothermic peak area in differential scanning calorimetry is 12.8 J / g to 20.5 J / g.
＜３＞　前記メソゲン骨格を有するエポキシ樹脂モノマーが、下記一般式（Ｉ－１）で表される化合物を含む前記＜１＞又は＜２＞に記載のエポキシ樹脂組成物。
Figure JPOXMLDOC01-appb-C000008
 <3> The epoxy resin composition according to <1> or <2>, wherein the epoxy resin monomer having a mesogenic skeleton includes a compound represented by the following general formula (I-1).
Figure JPOXMLDOC01-appb-C000008
＜４＞　前記ノボラック樹脂が、下記一般式（ＩＩ－１）及び（ＩＩ－２）からなる群より選択される少なくとも１つで表される構造単位を有する化合物を含む前記＜１＞～＜３＞のいずれか１項に記載のエポキシ樹脂組成物。
Figure JPOXMLDOC01-appb-C000009
［一般式（ＩＩ－１）及び（ＩＩ－２）中、Ｒ２１及びＲ２４はそれぞれ独立に、アルキル基、アリール基、又はアラルキル基を示し、該アルキル基、アリール基、及びアラルキル基は置換基を有していてもよい。Ｒ２２、Ｒ２３、Ｒ２５、及びＲ２６はそれぞれ独立に、水素原子、アルキル基、アリール基、又はアラルキル基を示し、該アルキル基、アリール基、及びアラルキル基は置換基を有していてもよい。ｍ２１及びｍ２２はそれぞれ独立に０～２の整数を示す。ｎ２１及びｎ２２はそれぞれ独立に１～７の整数を示す。］ <4> The above <1> to <3, wherein the novolak resin contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (II-1) and (II-2) > The epoxy resin composition of any one of>.
Figure JPOXMLDOC01-appb-C000009
[In the general formulas (II-1) and (II-2), R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group, and the alkyl group, aryl group, and aralkyl group are substituted. It may have a group. R 22 , R 23 , R 25 , and R 26 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and the alkyl group, aryl group, and aralkyl group each have a substituent. Also good. m21 and m22 each independently represents an integer of 0-2. n21 and n22 each independently represents an integer of 1 to 7. ]
＜５＞　前記ノボラック樹脂が、下記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造単位を有する化合物を含む前記＜１＞～＜３＞のいずれか１項に記載のエポキシ樹脂組成物。
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000011
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000013
［一般式（ＩＩＩ－１）～（ＩＩＩ－４）中、ｍ３１～ｍ３４及びｎ３１～ｎ３４はそれぞれ独立に、正の整数を示す。Ａｒ３１～Ａｒ３４はそれぞれ独立に、下記一般式（ＩＩＩ－ａ）で表される基又は下記一般式（ＩＩＩ－ｂ）で表される基を示す。］
Figure JPOXMLDOC01-appb-C000014
［一般式（ＩＩＩ－ａ）及び（ＩＩＩ－ｂ）中、Ｒ３１及びＲ３４はそれぞれ独立に、水素原子又は水酸基を示す。Ｒ３２及びＲ３３はそれぞれ独立に、水素原子又は炭素数１～８のアルキル基を示す。］ <5> The above <1> to <3, wherein the novolak resin contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (III-1) to (III-4) > The epoxy resin composition of any one of>.
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000011
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000013
[In the general formulas (III-1) to (III-4), m31 to m34 and n31 to n34 each independently represent a positive integer. Ar 31 to Ar 34 each independently represent a group represented by the following general formula (III-a) or a group represented by the following general formula (III-b). ]
Figure JPOXMLDOC01-appb-C000014
[In the general formulas (III-a) and (III-b), R 31 and R 34 each independently represents a hydrogen atom or a hydroxyl group. R 32 and R 33 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ]
＜６＞　前記無機フィラーの含有率が、６０体積％～９０体積％である前記＜１＞～＜５＞のいずれか１項に記載のエポキシ樹脂組成物。 <6> The epoxy resin composition according to any one of <1> to <5>, wherein the content of the inorganic filler is 60% by volume to 90% by volume.
＜７＞　前記無機フィラーが、アルミナ、窒化ホウ素、シリカ、酸化マグネシウム、窒化アルミニウム、及びマイカからなる群より選択される少なくとも１つの粒子である前記＜１＞～＜６＞のいずれか１項に記載のエポキシ樹脂組成物。 <7> In any one of the above items <1> to <6>, wherein the inorganic filler is at least one particle selected from the group consisting of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, and mica. The epoxy resin composition as described.
＜８＞　前記＜１＞～＜７＞のいずれか１項に記載のエポキシ樹脂組成物のシート状成形体である樹脂シート。 <8> A resin sheet which is a sheet-like molded body of the epoxy resin composition according to any one of <1> to <7>.
＜９＞　繊維基材と、前記＜１＞～＜７＞のいずれか１項に記載のエポキシ樹脂組成物を含む樹脂マトリックスと、を有するプリプレグ。 <9> A prepreg having a fiber base and a resin matrix containing the epoxy resin composition according to any one of <1> to <7>.
＜１０＞　被着材と、
　前記被着材上に配置され、前記＜１＞～＜７＞のいずれか１項に記載のエポキシ樹脂組成物、前記＜８＞に記載の樹脂シート、及び前記＜９＞に記載のプリプレグからなる群より選択される少なくとも１つの半硬化体である半硬化層又は硬化体である硬化層と、を有する積層板。 <10> A substrate,
From the epoxy resin composition according to any one of <1> to <7>, the resin sheet according to <8>, and the prepreg according to <9>, which is disposed on the adherend. A laminate having at least one semi-cured layer selected from the group consisting of a semi-cured layer or a cured layer that is a cured body.
＜１１＞　メソゲン骨格を有するエポキシ樹脂モノマーと、ノボラック樹脂を含む硬化剤と、無機フィラーと、を含有する組成物を熱処理し、前記メソゲン骨格を有するエポキシ樹脂モノマーのオリゴマー体を生成させて前記＜１＞～＜７＞のいずれか１項に記載のエポキシ樹脂組成物を得る工程を含むエポキシ樹脂組成物の製造方法。 <11> A composition containing an epoxy resin monomer having a mesogenic skeleton, a curing agent containing a novolac resin, and an inorganic filler is heat-treated to produce an oligomer of the epoxy resin monomer having the mesogenic skeleton, A method for producing an epoxy resin composition, comprising a step of obtaining the epoxy resin composition according to any one of 1> to <7>.
＜１２＞　前記＜１＞～＜７＞のいずれか１項に記載のエポキシ樹脂組成物、前記＜８＞に記載の樹脂シート、又は前記＜９＞に記載のプリプレグを硬化させた硬化体。 <12> A cured product obtained by curing the epoxy resin composition according to any one of <1> to <7>, the resin sheet according to <8>, or the prepreg according to <9>.
　本発明によれば、常温でも柔軟性を有し、かつ硬化体が高熱伝導性を有するエポキシ樹脂組成物及びその製造方法、並びにこのエポキシ樹脂組成物を用いる樹脂シート、プリプレグ、積層板、及び硬化体を提供することができる。 According to the present invention, an epoxy resin composition having flexibility even at room temperature and a cured body having high thermal conductivity, a method for producing the same, and a resin sheet, prepreg, laminate, and curing using the epoxy resin composition The body can be provided.
実施例１の樹脂シートにおけるゲルパーミエーションクロマトグラフィー（ＧＰＣ）測定のチャートを示す図である。3 is a diagram showing a chart of gel permeation chromatography (GPC) measurement in the resin sheet of Example 1. FIG. 実施例１の樹脂シートにおける示差走査熱量（ＤＳＣ）測定のチャートを示す図であり、吸熱ピーク面積の算出部分を併せて示す。It is a figure which shows the chart of the differential scanning calorimetry (DSC) measurement in the resin sheet of Example 1, and also shows the calculation part of the endothermic peak area. 実施例１の樹脂シートにおける示差走査熱量（ＤＳＣ）測定のチャートを示す図であり、発熱ピーク面積の算出部分を併せて示す。It is a figure which shows the chart of the differential scanning calorific value (DSC) measurement in the resin sheet of Example 1, and also shows the calculation part of the exothermic peak area.
　本明細書において「～」を用いて示された数値範囲は、「～」の前後に記載される数値をそれぞれ最小値及び最大値として含む範囲を示す。
　本明細書中に段階的に記載されている数値範囲において、一つの数値範囲で記載された上限値又は下限値は、他の段階的な記載の数値範囲の上限値又は下限値に置き換えてもよい。また、本明細書中に記載されている数値範囲において、その数値範囲の上限値又は下限値は、実施例に示されている値に置き換えてもよい。
　また、組成物中の各成分の量は、組成物中に各成分に該当する物質が複数存在する場合、特に断らない限り、組成物中に存在する当該複数の物質の合計量を意味する。
　また、本明細書において「層」との語は、平面視したときに全面に形成されている形状の構成に加え、一部に形成されている形状の構成も包含される。
　また、本明細書において「工程」との語は、独立した工程だけではなく、他の工程と明確に区別できない場合であってもその工程の所期の目的が達成されれば、本用語に含まれる。 In the present specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.
In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of another numerical range. Good. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the values shown in the examples.
Further, the amount of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition.
In addition, in the present specification, the term “layer” includes a configuration of a part formed in addition to a configuration of a shape formed on the entire surface when viewed in plan.
In addition, in this specification, the term “process” is not limited to an independent process, and even if it cannot be clearly distinguished from other processes, the term “process” is used if the intended purpose of the process is achieved. included.
＜エポキシ樹脂組成物＞
　本開示のエポキシ樹脂組成物は、メソゲン骨格を有するエポキシ樹脂モノマー及びそのオリゴマー体と、ノボラック樹脂を含む硬化剤と、無機フィラーと、を含有し、上記オリゴマー体は、上記メソゲン骨格を有するエポキシ樹脂モノマーと上記ノボラック樹脂との反応物を含む。本開示のエポキシ樹脂組成物は、必要に応じてその他の成分をさらに含有していてもよい。
　また、本開示のエポキシ樹脂組成物は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）測定における上記オリゴマー体の重量平均分子量が１０００～３０００であり、示差走査熱量（ＤＳＣ）測定における吸熱ピーク面積が２．５Ｊ／ｇ以下であり、４ｃｍ×４ｃｍ×１５０μｍのサンプルを１９０℃の恒温槽で２時間加熱したときの熱重量減少率が０．４質量％以下である。
　かかる構成を有する本開示のエポキシ樹脂組成物は、常温（２０℃～３０℃）でも柔軟性を有し、かつ硬化体が高熱伝導性を有する。 <Epoxy resin composition>
The epoxy resin composition of the present disclosure includes an epoxy resin monomer having a mesogen skeleton and an oligomer thereof, a curing agent containing a novolac resin, and an inorganic filler, and the oligomer is an epoxy resin having the mesogen skeleton. A reaction product of the monomer and the novolak resin is included. The epoxy resin composition of the present disclosure may further contain other components as necessary.
In addition, the epoxy resin composition of the present disclosure has a weight average molecular weight of 1000 to 3000 in the above-mentioned oligomer body in gel permeation chromatography (GPC) measurement, and an endothermic peak area in differential scanning calorimetry (DSC) measurement is 2.5 J. / G or less, and the thermal weight loss rate when a sample of 4 cm × 4 cm × 150 μm is heated in a thermostat at 190 ° C. for 2 hours is 0.4 mass% or less.
The epoxy resin composition of the present disclosure having such a configuration has flexibility even at room temperature (20 ° C. to 30 ° C.), and the cured body has high thermal conductivity.
　以下、本開示のエポキシ樹脂組成物を構成する各成分について説明する。 Hereinafter, each component constituting the epoxy resin composition of the present disclosure will be described.
（エポキシ樹脂モノマー）
　本開示のエポキシ樹脂組成物は、メソゲン骨格を有するエポキシ樹脂モノマーを含有する。メソゲン骨格を有するエポキシ樹脂モノマーは、硬化時に高次構造を形成し易く、エポキシ樹脂組成物の硬化体を作製した場合に、より高い熱伝導率を達成できる傾向にある。 (Epoxy resin monomer)
The epoxy resin composition of the present disclosure contains an epoxy resin monomer having a mesogenic skeleton. An epoxy resin monomer having a mesogenic skeleton tends to form a higher order structure upon curing, and tends to achieve higher thermal conductivity when a cured product of the epoxy resin composition is produced.
　ここで、メソゲン骨格とは、分子間相互作用の働きにより結晶性又は液晶性を発現し易くするような分子構造のことを指す。具体的には、ビフェニル骨格、フェニルベンゾエート骨格、アゾベンゼン骨格、スチルベン骨格、シクロヘキシルベンゼン骨格、それらの誘導体等が挙げられる。 Here, the mesogenic skeleton refers to a molecular structure that facilitates the expression of crystallinity or liquid crystallinity by the action of intermolecular interaction. Specific examples include a biphenyl skeleton, a phenylbenzoate skeleton, an azobenzene skeleton, a stilbene skeleton, a cyclohexylbenzene skeleton, and derivatives thereof.
　また、高次構造とは、その構成要素がミクロな配列をしている状態のことであり、例えば、結晶相及び液晶相が相当する。このような高次構造が存在しているか否かは、偏光顕微鏡での観察によって容易に判断することが可能である。すなわち、クロスニコル状態での観察において、偏光解消による干渉模様が見られる場合は高次構造が存在していると判断できる。
　高次構造は、通常では樹脂中に島状に存在しており、ドメイン構造を形成している。そして、ドメイン構造を形成している島のそれぞれを高次構造体という。高次構造体を構成する構造単位同士は、一般的には共有結合で結合している。 Further, the higher order structure is a state in which the constituent elements are in a micro array, and corresponds to, for example, a crystal phase and a liquid crystal phase. Whether or not such a higher-order structure exists can be easily determined by observation with a polarizing microscope. That is, when an interference pattern due to depolarization is observed in the observation in the crossed Nicol state, it can be determined that a higher order structure exists.
The higher order structure usually exists in an island shape in the resin, and forms a domain structure. Each island forming the domain structure is called a higher-order structure. The structural units constituting the higher order structure are generally bonded by a covalent bond.
　メソゲン骨格を有するエポキシ樹脂モノマーとしては、具体的には、下記一般式（Ｉ）で表されるエポキシ樹脂モノマー（特許第５４７１９７５号公報に記載）、下記一般式（ＩＶ）で表されるエポキシ樹脂モノマー（特許第４１１８６９１号公報に記載）、下記一般式（Ｖ）で表されるエポキシ樹脂モノマー（特許第４６１９７７０号公報及び特開２００８－１３７５９号公報に記載）、下記一般式（ＶＩ）で表されるエポキシ樹脂モノマー（特開２０１０－２４１７９７号公報に記載）、下記一般式（ＶＩＩ）で表されるエポキシ樹脂モノマー（特開２０１１－９８９５２号公報に記載）等が挙げられる。 Specific examples of the epoxy resin monomer having a mesogenic skeleton include an epoxy resin monomer represented by the following general formula (I) (described in Japanese Patent No. 5471975) and an epoxy resin represented by the following general formula (IV). Monomer (described in Japanese Patent No. 4118691), epoxy resin monomer represented by the following general formula (V) (described in Japanese Patent No. 4619770 and Japanese Patent Application Laid-Open No. 2008-13759), represented by the following general formula (VI) Epoxy resin monomers (described in JP 2010-241797 A), epoxy resin monomers represented by the following general formula (VII) (described in JP 2011-98952 A), and the like.
Figure JPOXMLDOC01-appb-C000015
Figure JPOXMLDOC01-appb-C000015
　上記一般式（Ｉ）中、Ｒ１～Ｒ４はそれぞれ独立に、水素原子又は炭素数１～３のアルキル基を示す。 In the general formula (I), R 1 to R 4 each independently represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms.
Figure JPOXMLDOC01-appb-C000016
Figure JPOXMLDOC01-appb-C000016
　上記一般式（ＩＶ）中、ｎは４、６、又は８を示す。 In the above general formula (IV), n represents 4, 6, or 8.
Figure JPOXMLDOC01-appb-C000017
Figure JPOXMLDOC01-appb-C000017
　上記一般式（Ｖ）中、Ａｒ１～Ａｒ３はそれぞれ独立に、下記一般式のいずれかで示される二価基を示す。Ｒ５～Ｒ１０はそれぞれ独立に、水素原子又は炭素数１～１８のアルキル基を示す。Ｑ１及びＱ２はそれぞれ独立に、炭素数１～９の直鎖状アルキレン基を示し、該直鎖状アルキレン基を構成するメチレン基は、炭素数１～１８のアルキレン基で置換されていてもよく、また、該メチレン基の間に－Ｏ－又は－Ｎ（Ｒ１１）－が挿入されていてもよい。ここで、Ｒ１１は、水素原子又は炭素数１～１８のアルキル基を示す。 In the general formula (V), Ar 1 to Ar 3 each independently represents a divalent group represented by any one of the following general formulas. R 5 to R 10 each independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. Q 1 and Q 2 each independently represent a linear alkylene group having 1 to 9 carbon atoms, and the methylene group constituting the linear alkylene group is substituted with an alkylene group having 1 to 18 carbon atoms. In addition, —O— or —N (R 11 ) — may be inserted between the methylene groups. Here, R 11 represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms.
Figure JPOXMLDOC01-appb-C000018
Figure JPOXMLDOC01-appb-C000018
　Ｒ１２はそれぞれ独立に、水素原子又は炭素数１～１８のアルキル基を示す。ａは１～８の整数を、ｂ、ｅ、及びｇは１～６の整数を、ｃは１～７の整数を、ｄ及びｈは１～４の整数を、ｆは１～５の整数をそれぞれ示す。また、上記二価基においてＲ１２が複数のとき、全てのＲ１２が同一の基を示してもよく、異なる基を示してもよい。 R 12 each independently represents a hydrogen atom or an alkyl group having 1 to 18 carbon atoms. a is an integer of 1 to 8, b, e, and g are integers of 1 to 6, c is an integer of 1 to 7, d and h are integers of 1 to 4, and f is an integer of 1 to 5. Respectively. In the above divalent group, when there are a plurality of R 12 groups, all R 12 groups may represent the same group or different groups.
Figure JPOXMLDOC01-appb-C000019
Figure JPOXMLDOC01-appb-C000019
　上記一般式（ＶＩ）中、Ｒ１３～Ｒ１６はそれぞれ独立に、水素原子、炭素数１～３のアルキル基、又は炭素数１～３のアルコキシ基を示し、Ｒ１７～Ｒ２０はそれぞれ独立に、水素原子、メチル基、又は炭素数１～３のアルコキシ基を示す。 In the general formula (VI), R 13 to R 16 are each independently a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an alkoxy group having 1 to 3 carbon atoms, and R 17 to R 20 are each independently Represents a hydrogen atom, a methyl group, or an alkoxy group having 1 to 3 carbon atoms.
Figure JPOXMLDOC01-appb-C000020
Figure JPOXMLDOC01-appb-C000020
　また、市販品ではＹＬ６１２１Ｈ（三菱化学株式会社製）等がメソゲン骨格を有するエポキシ樹脂モノマーの具体例として挙げられる。 In addition, YL6121H (manufactured by Mitsubishi Chemical Co., Ltd.) is a specific example of an epoxy resin monomer having a mesogen skeleton.
　以上、メソゲン骨格を有するエポキシ樹脂モノマーの具体例を示したが、メソゲン骨格を有するエポキシ樹脂モノマーはこれらの具体例に限定されない。これらのエポキシ樹脂モノマーの中では、硬化体が高熱伝導性を有するといった観点から、上記一般式（Ｉ）で表されるエポキシ樹脂モノマーが好ましく、下記一般式（Ｉ－１）で表されるエポキシ樹脂モノマーがより好ましい。 Specific examples of the epoxy resin monomer having a mesogen skeleton have been described above, but the epoxy resin monomer having a mesogen skeleton is not limited to these specific examples. Among these epoxy resin monomers, from the viewpoint that the cured product has high thermal conductivity, the epoxy resin monomer represented by the general formula (I) is preferable, and the epoxy resin represented by the following general formula (I-1) is preferable. A resin monomer is more preferable.
Figure JPOXMLDOC01-appb-C000021
Figure JPOXMLDOC01-appb-C000021
　本開示のエポキシ樹脂組成物は、メソゲン骨格を有さないエポキシ樹脂モノマーを含有していてもよい。ただし、メソゲン骨格を有するエポキシ樹脂モノマーの割合は、エポキシ樹脂モノマー全体に対して８０質量％以上であることが好ましく、９０質量％以上であることがより好ましい。 The epoxy resin composition of the present disclosure may contain an epoxy resin monomer having no mesogen skeleton. However, the ratio of the epoxy resin monomer having a mesogenic skeleton is preferably 80% by mass or more, and more preferably 90% by mass or more with respect to the entire epoxy resin monomer.
　エポキシ樹脂組成物中におけるメソゲン骨格を有するエポキシ樹脂モノマーの含有率は特に制限されない。成形性及び硬化体の熱伝導性の観点から、メソゲン骨格を有するエポキシ樹脂モノマーの含有率は、エポキシ樹脂組成物中に５質量％～３５質量％であることが好ましく、５質量％～２５質量％であることがより好ましい。 The content of the epoxy resin monomer having a mesogen skeleton in the epoxy resin composition is not particularly limited. From the viewpoint of moldability and the thermal conductivity of the cured product, the content of the epoxy resin monomer having a mesogenic skeleton is preferably 5% by mass to 35% by mass in the epoxy resin composition. % Is more preferable.
（硬化剤）
　本開示のエポキシ樹脂組成物は、ノボラック樹脂を含む硬化剤を含有する。上記ノボラック樹脂としては、カテコール、レゾルシノール、ヒドロキノン、１，２－ナフタレンジオール、１，３－ナフタレンジオール等の２価のフェノール樹脂モノマーをノボラック化したものが好ましい。２価のフェノール樹脂モノマーを用いることで硬化体の熱伝導性が向上し、これらの化合物をノボラック化したものを用いることでさらに硬化体の耐熱性が向上する傾向にある。 (Curing agent)
The epoxy resin composition of this indication contains the hardening | curing agent containing a novolak resin. The novolac resin is preferably a novolak-modified divalent phenol resin monomer such as catechol, resorcinol, hydroquinone, 1,2-naphthalenediol, 1,3-naphthalenediol. The thermal conductivity of the cured product is improved by using a divalent phenol resin monomer, and the heat resistance of the cured product tends to be further improved by using a novolak form of these compounds.
　上記ノボラック樹脂は、下記一般式（ＩＩ－１）及び（ＩＩ－２）からなる群より選択される少なくとも１つで表される構造単位を有する化合物を含むことが好ましい。上記ノボラック樹脂の全体に占める当該化合物の割合は、７０質量％以上であることが好ましく、８０質量％以上であることがより好ましい。 The novolak resin preferably contains a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (II-1) and (II-2). The proportion of the compound in the entire novolak resin is preferably 70% by mass or more, and more preferably 80% by mass or more.
Figure JPOXMLDOC01-appb-C000022
Figure JPOXMLDOC01-appb-C000022
　上記一般式（ＩＩ－１）及び（ＩＩ－２）中、Ｒ２１及びＲ２４はそれぞれ独立に、アルキル基、アリール基、又はアラルキル基を示す。Ｒ２１又はＲ２４で示されるアルキル基、アリール基、及びアラルキル基は、さらに置換基を有していてもよい。該置換基としては、アルキル基、アリール基、ハロゲン原子、水酸基等を挙げることができる。 In the general formulas (II-1) and (II-2), R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group. The alkyl group, aryl group, and aralkyl group represented by R 21 or R 24 may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, a halogen atom, and a hydroxyl group.
　Ｒ２１及びＲ２４はそれぞれ独立に、アルキル基、アリール基、又はアラルキル基を示し、炭素数１～６のアルキル基、炭素数６～１２のアリール基、又は炭素数７～１３のアラルキル基であることが好ましく、炭素数１～６のアルキル基であることがより好ましい。 R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group, and is an alkyl group having 1 to 6 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. Preferably, it is an alkyl group having 1 to 6 carbon atoms.
　ｍ２１及びｍ２２はそれぞれ独立に、０～２の整数を示す。ｍ２１が２である場合、２つのＲ２１は同一であっても異なっていてもよく、ｍ２２が２である場合、２つのＲ２４は同一であっても異なっていてもよい。ｍ２１及びｍ２２はそれぞれ独立に、０又は１であることが好ましく、０であることがより好ましい。 m21 and m22 each independently represents an integer of 0-2. When m21 is 2, two R 21 may be the same or different, and when m22 is 2, two R 24 may be the same or different. m21 and m22 are each independently preferably 0 or 1, and more preferably 0.
　また、ｎ２１及びｎ２２はそれぞれ独立に、１～７の整数を示し、上記一般式（ＩＩ－１）及び（ＩＩ－２）からなる群より選択される少なくとも１つで表される構造単位を有する化合物中における上記一般式（ＩＩ－１）で表される構造単位又は上記一般式（ＩＩ－２）で表される構造単位の含有数をそれぞれ示す。 N21 and n22 each independently represents an integer of 1 to 7, and has a structural unit represented by at least one selected from the group consisting of the general formulas (II-1) and (II-2) The number of the structural unit represented by the general formula (II-1) or the structural unit represented by the general formula (II-2) in the compound is shown.
　上記一般式（ＩＩ－１）及び（ＩＩ－２）中、Ｒ２２、Ｒ２３、Ｒ２５、及びＲ２６はそれぞれ独立に、水素原子、アルキル基、アリール基、又はアラルキル基を示す。Ｒ２２、Ｒ２３、Ｒ２５、又はＲ２６で表されるアルキル基、アリール基、及びアラルキル基は、置換基をさらに有していてもよい。該置換基としては、アルキル基、アリール基、ハロゲン原子、水酸基等を挙げることができる。 In the general formulas (II-1) and (II-2), R 22 , R 23 , R 25 , and R 26 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group. The alkyl group, aryl group, and aralkyl group represented by R 22 , R 23 , R 25 , or R 26 may further have a substituent. Examples of the substituent include an alkyl group, an aryl group, a halogen atom, and a hydroxyl group.
　Ｒ２２、Ｒ２３、Ｒ２５、及びＲ２６としては、エポキシ樹脂組成物の保存安定性及び硬化体の熱伝導性の観点から、水素原子、アルキル基、又はアリール基であることが好ましい。Ｒ２２、Ｒ２３、Ｒ２５、及びＲ２６としては、より好ましくは、水素原子、炭素数１～４のアルキル基、又は炭素数６～１２のアリール基であり、水素原子であることがさらに好ましい。
　さらに、硬化体の耐熱性の観点から、Ｒ２２及びＲ２３の少なくとも一方、又はＲ２５及びＲ２６の少なくとも一方がアリール基であることもまた好ましく、炭素数６～１２のアリール基であることがより好ましい。
　なお、上記アリール基は芳香族基にヘテロ原子（酸素原子、窒素原子、硫黄原子等）を含んでいてもよく、ヘテロ原子と炭素原子との合計数が６～１２となるヘテロアリール基であることが好ましい。 R 22 , R 23 , R 25 , and R 26 are preferably a hydrogen atom, an alkyl group, or an aryl group from the viewpoint of the storage stability of the epoxy resin composition and the thermal conductivity of the cured product. R 22 , R 23 , R 25 , and R 26 are more preferably a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 12 carbon atoms, and more preferably a hydrogen atom. preferable.
Furthermore, from the viewpoint of heat resistance of the cured product, it is also preferable that at least one of R 22 and R 23 or at least one of R 25 and R 26 is an aryl group, and it is an aryl group having 6 to 12 carbon atoms. Is more preferable.
The aryl group may be a heteroaryl group in which the aromatic group may contain a hetero atom (oxygen atom, nitrogen atom, sulfur atom, etc.), and the total number of hetero atoms and carbon atoms is 6 to 12. It is preferable.
　上記ノボラック樹脂は、上記一般式（ＩＩ－１）で表される構造単位又は上記一般式（ＩＩ－２）で表される構造単位を有する化合物を１種単独で含むものであってもよいし、２種以上を含むものであってもよい。上記ノボラック樹脂は、硬化体の熱伝導性の観点から、上記一般式（ＩＩ－１）で表される構造単位を有する化合物を含むことが好ましく、上記一般式（ＩＩ－１）で表され、レゾルシノールに由来する構造単位を有する化合物を少なくとも含むことがより好ましい。 The novolak resin may contain one type of compound having the structural unit represented by the general formula (II-1) or the structural unit represented by the general formula (II-2). Two or more types may be included. The novolak resin preferably contains a compound having a structural unit represented by the general formula (II-1) from the viewpoint of thermal conductivity of the cured body, and is represented by the general formula (II-1), It is more preferable to include at least a compound having a structural unit derived from resorcinol.
　上記一般式（ＩＩ－１）で表される構造単位を有する化合物が、レゾルシノールに由来する構造単位を有する場合、レゾルシノール以外のフェノール樹脂モノマーに由来する部分構造の少なくとも１種をさらに含んでいてもよい。レゾルシノール以外のフェノール樹脂モノマーとしては、フェノール、クレゾール、カテコール、ヒドロキノン、１，２，３－トリヒドロキシベンゼン、１，２，４－トリヒドロキシベンゼン、１，３，５－トリヒドロキシベンゼン等を挙げることができる。上記一般式（ＩＩ－１）で表される構造単位を有する化合物は、これらのフェノール樹脂モノマーに由来する部分構造を１種単独で含んでいてもよく、２種以上を組み合わせて含んでいてもよい。 When the compound having the structural unit represented by the general formula (II-1) has a structural unit derived from resorcinol, it may further include at least one partial structure derived from a phenol resin monomer other than resorcinol. Good. Examples of phenol resin monomers other than resorcinol include phenol, cresol, catechol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,3,5-trihydroxybenzene, and the like. Can do. The compound having the structural unit represented by the general formula (II-1) may contain one kind of partial structure derived from these phenol resin monomers, or may contain two or more kinds in combination. Good.
　また、上記一般式（ＩＩ－２）で表され、カテコールに由来する構造単位を有する化合物においても、カテコール以外のフェノール樹脂モノマーに由来する部分構造の少なくとも１種をさらに含んでいてもよい。カテコール以外のフェノール樹脂モノマーとしては、フェノール、クレゾール、レゾルシノール、ヒドロキノン、１，２，３－トリヒドロキシベンゼン、１，２，４－トリヒドロキシベンゼン、１，３，５－トリヒドロキシベンゼン等を挙げることができる。上記一般式（ＩＩ－２）で表される構造単位を有する化合物は、これらのフェノール樹脂モノマーに由来する部分構造を１種単独で含んでいてもよく、２種以上を組み合わせて含んでいてもよい。 The compound represented by the above general formula (II-2) and having a structural unit derived from catechol may further contain at least one partial structure derived from a phenol resin monomer other than catechol. Examples of phenol resin monomers other than catechol include phenol, cresol, resorcinol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, 1,3,5-trihydroxybenzene, and the like. Can do. The compound having the structural unit represented by the general formula (II-2) may contain one kind of partial structure derived from these phenol resin monomers, or may contain two or more kinds in combination. Good.
　ここで、フェノール樹脂モノマーに由来する部分構造とは、フェノール樹脂モノマーの芳香環部分から１個又は２個の水素原子を取り除いて構成される、１価又は２価の基を意味する。なお、水素原子が取り除かれる位置は特に限定されない。 Here, the partial structure derived from the phenol resin monomer means a monovalent or divalent group constituted by removing one or two hydrogen atoms from the aromatic ring portion of the phenol resin monomer. The position where the hydrogen atom is removed is not particularly limited.
　上記一般式（ＩＩ－１）で表される構造単位を有する化合物において、レゾルシノール以外のフェノール樹脂モノマーに由来する部分構造としては、硬化体の熱伝導性、並びにエポキシ樹脂組成物の接着性及び保存安定性の観点から、フェノール、クレゾール、カテコール、ヒドロキノン、１，２，３－トリヒドロキシベンゼン、１，２，４－トリヒドロキシベンゼン、及び１，３，５－トリヒドロキシベンゼンからなる群より選択される少なくとも１種に由来する部分構造であることが好ましく、カテコール及びヒドロキノンから選ばれる少なくとも１種に由来する部分構造であることがより好ましい。 In the compound having the structural unit represented by the general formula (II-1), the partial structure derived from the phenol resin monomer other than resorcinol includes the thermal conductivity of the cured product and the adhesiveness and storage of the epoxy resin composition. From the viewpoint of stability, it is selected from the group consisting of phenol, cresol, catechol, hydroquinone, 1,2,3-trihydroxybenzene, 1,2,4-trihydroxybenzene, and 1,3,5-trihydroxybenzene. It is preferably a partial structure derived from at least one kind, and more preferably a partial structure derived from at least one kind selected from catechol and hydroquinone.
　また、上記一般式（ＩＩ－１）で表される構造単位を有する化合物がレゾルシノールに由来する構造単位を含む場合、レゾルシノールに由来する部分構造の含有比率については特に制限はない。硬化体の弾性率の観点から、上記一般式（ＩＩ－１）で表される構造単位を有する化合物の全質量に対するレゾルシノールに由来する部分構造の含有比率は、５５質量％以上であることが好ましく、エポキシ樹脂のガラス転移温度（Ｔｇ）及び硬化体の線膨張率の観点から、６０質量％以上であることがより好ましく、８０質量％以上であることがさらに好ましく、硬化体の熱伝導性の観点から、９０質量％以上であることが特に好ましい。 In addition, when the compound having the structural unit represented by the general formula (II-1) includes a structural unit derived from resorcinol, the content ratio of the partial structure derived from resorcinol is not particularly limited. From the viewpoint of the elastic modulus of the cured product, the content ratio of the partial structure derived from resorcinol to the total mass of the compound having the structural unit represented by the general formula (II-1) is preferably 55% by mass or more. From the viewpoint of the glass transition temperature (Tg) of the epoxy resin and the linear expansion coefficient of the cured product, it is more preferably 60% by mass or more, further preferably 80% by mass or more, and the thermal conductivity of the cured product. From the viewpoint, it is particularly preferably 90% by mass or more.
　上記一般式（ＩＩ－１）及び（ＩＩ－２）からなる群より選択される少なくとも１つで表される構造単位を有する化合物の分子量は特に制限されない。エポキシ樹脂組成物の流動性の観点から、数平均分子量（Ｍｎ）としては２０００以下であることが好ましく、１５００以下であることがより好ましく、３５０～１５００であることがさらに好ましい。また、重量平均分子量（Ｍｗ）としては２０００以下であることが好ましく、１５００以下であることがより好ましく、４００～１５００であることがさらに好ましい。
　これらＭｎ及びＭｗは、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）を用いた通常の方法により測定される。 The molecular weight of the compound having a structural unit represented by at least one selected from the group consisting of the general formulas (II-1) and (II-2) is not particularly limited. From the viewpoint of fluidity of the epoxy resin composition, the number average molecular weight (Mn) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 350 to 1500. The weight average molecular weight (Mw) is preferably 2000 or less, more preferably 1500 or less, and further preferably 400 to 1500.
These Mn and Mw are measured by a usual method using gel permeation chromatography (GPC).
　上記一般式（ＩＩ－１）及び（ＩＩ－２）からなる群より選択される少なくとも１つで表される構造単位を有する化合物の水酸基当量は特に制限されない。耐熱性に関与する架橋密度の観点から、水酸基当量は平均値で５０ｇ／ｅｑ～１５０ｇ／ｅｑであることが好ましく、５０ｇ／ｅｑ～１２０ｇ／ｅｑであることがより好ましく、５５ｇ／ｅｑ～１２０ｇ／ｅｑであることがさらに好ましい。 The hydroxyl equivalent of the compound having a structural unit represented by at least one selected from the group consisting of the general formulas (II-1) and (II-2) is not particularly limited. From the viewpoint of the crosslinking density involved in heat resistance, the hydroxyl group equivalent is preferably 50 g / eq to 150 g / eq on average, more preferably 50 g / eq to 120 g / eq, and 55 g / eq to 120 g / eq. More preferably, it is eq.
　また、上記ノボラック樹脂は、下記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物を含むことも好ましい。上記ノボラック樹脂の全体に占める当該化合物の割合は、７０質量％以上であることが好ましく、８０質量％以上であることがより好ましい。 Further, the novolak resin preferably contains a compound having a structure represented by at least one selected from the group consisting of the following general formulas (III-1) to (III-4). The proportion of the compound in the entire novolak resin is preferably 70% by mass or more, and more preferably 80% by mass or more.
Figure JPOXMLDOC01-appb-C000023
Figure JPOXMLDOC01-appb-C000023
Figure JPOXMLDOC01-appb-C000024
Figure JPOXMLDOC01-appb-C000024
Figure JPOXMLDOC01-appb-C000025
Figure JPOXMLDOC01-appb-C000025
Figure JPOXMLDOC01-appb-C000026
Figure JPOXMLDOC01-appb-C000026
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）中、ｍ３１～ｍ３４及びｎ３１～ｎ３４はそれぞれ独立に、正の整数を示す。Ａｒ３１～Ａｒ３４はそれぞれ独立に、下記一般式（ＩＩＩ－ａ）で表される基又は下記一般式（ＩＩＩ－ｂ）で表される基を示す。 In the general formulas (III-1) to (III-4), m31 to m34 and n31 to n34 each independently represent a positive integer. Ar 31 to Ar 34 each independently represent a group represented by the following general formula (III-a) or a group represented by the following general formula (III-b).
Figure JPOXMLDOC01-appb-C000027
Figure JPOXMLDOC01-appb-C000027
　上記一般式（ＩＩＩ－ａ）及び（ＩＩＩ－ｂ）中、Ｒ３１及びＲ３４はそれぞれ独立に、水素原子又は水酸基を示す。Ｒ３２及びＲ３３はそれぞれ独立に、水素原子又は炭素数１～８のアルキル基を示す。 In the above general formulas (III-a) and (III-b), R 31 and R 34 each independently represent a hydrogen atom or a hydroxyl group. R 32 and R 33 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物は、２価のフェノール樹脂モノマーをノボラック化する後述の製造方法によって、副生成的に生成可能なものである。 The compound having a structure represented by at least one selected from the group consisting of the above general formulas (III-1) to (III-4) can be produced by a production method described later in which a divalent phenol resin monomer is novolakized. It can be generated as a by-product.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造は、上記ノボラック樹脂の主鎖骨格として含まれていてもよく、また、上記ノボラック樹脂の側鎖の一部として含まれていてもよい。さらに、上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）のいずれか１つで表される構造を構成するそれぞれの構造単位は、ランダムに含まれていてもよいし、規則的に含まれていてもよいし、ブロック状に含まれていてもよい。
　また、上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）において、水酸基の置換位置は芳香環上であれば特に制限されない。 The structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) may be included as a main chain skeleton of the novolak resin, and the novolak It may be contained as part of the side chain of the resin. Furthermore, each structural unit constituting the structure represented by any one of the general formulas (III-1) to (III-4) may be included randomly or regularly. It may be included or may be included in a block shape.
In the above general formulas (III-1) to (III-4), the hydroxyl group substitution position is not particularly limited as long as it is on the aromatic ring.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）のそれぞれについて、複数存在するＡｒ３１～Ａｒ３４は全て同一の原子団であってもよいし、２種以上の原子団を含んでいてもよい。なお、Ａｒ３１～Ａｒ３４はそれぞれ独立に、上記一般式（ＩＩＩ－ａ）で表される基及び上記一般式（ＩＩＩ－ｂ）で表される基のいずれかを示す。 For each of the general formulas (III-1) to (III-4), a plurality of Ar 31 to Ar 34 may all be the same atomic group, or may contain two or more atomic groups. Good. Ar 31 to Ar 34 each independently represent either a group represented by the general formula (III-a) or a group represented by the general formula (III-b).
　上記一般式（ＩＩＩ－ａ）及び（ＩＩＩ－ｂ）中、Ｒ３１及びＲ３４はそれぞれ独立に、水素原子又は水酸基を示し、硬化体の熱伝導性の観点から水酸基であることが好ましい。また、Ｒ３１及びＲ３４の置換位置は特に制限されない。 In the above general formulas (III-a) and (III-b), R 31 and R 34 each independently represents a hydrogen atom or a hydroxyl group, and is preferably a hydroxyl group from the viewpoint of thermal conductivity of the cured product. Further, the substitution positions of R 31 and R 34 are not particularly limited.
　また、上記一般式（ＩＩＩ－ａ）及び（ＩＩＩ－ｂ）中、Ｒ３２及びＲ３３はそれぞれ独立に、水素原子又は炭素数１～８のアルキル基を示す。Ｒ３２及びＲ３３における炭素数１～８のアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔ－ブチル基、ペンチル基、ヘキシル基、ヘプチル基、オクチル基等が挙げられる。また、上記一般式（ＩＩＩ－ａ）及び（ＩＩＩ－ｂ）におけるＲ３２及びＲ３３の置換位置は特に制限されない。 In the general formulas (III-a) and (III-b), R 32 and R 33 each independently represent a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. Examples of the alkyl group having 1 to 8 carbon atoms in R 32 and R 33 include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, heptyl, octyl Groups and the like. In addition, the substitution positions of R 32 and R 33 in the general formulas (III-a) and (III-b) are not particularly limited.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）におけるＡｒ３１～Ａｒ３４はそれぞれ独立に、本発明の効果、特に硬化体について優れた熱伝導性を達成する観点から、ジヒドロキシベンゼンに由来する基（すなわち、上記一般式（ＩＩＩ－ａ）においてＲ３１が水酸基であって、Ｒ３２及びＲ３３が水素原子である基）、及びジヒドロキシナフタレンに由来する基（すなわち、上記一般式（ＩＩＩ－ｂ）においてＲ３４が水酸基である基）から選ばれる少なくとも１種であることが好ましい。 In the above general formulas (III-1) to (III-4), Ar 31 to Ar 34 are each independently derived from dihydroxybenzene from the viewpoint of achieving the effects of the present invention, particularly excellent thermal conductivity for the cured product. A group (that is, a group in which R 31 is a hydroxyl group and R 32 and R 33 are a hydrogen atom in the above general formula (III-a)) and a group derived from dihydroxynaphthalene (that is, the above general formula (III- It is preferable that at least one selected from R) in which R 34 is a hydroxyl group in b).
　ここで、「ジヒドロキシベンゼンに由来する基」とは、ジヒドロキシベンゼンの芳香環部分から２つの水素原子を取り除いて構成される２価の基を意味し、水素原子が取り除かれる位置は特に制限されない。「ジヒドロキシナフタレンに由来する基」についても同様の意味である。 Here, the “group derived from dihydroxybenzene” means a divalent group formed by removing two hydrogen atoms from the aromatic ring portion of dihydroxybenzene, and the position at which the hydrogen atom is removed is not particularly limited. The “group derived from dihydroxynaphthalene” has the same meaning.
　また、エポキシ樹脂組成物の生産性及び流動性の観点から、Ａｒ３１～Ａｒ３４はそれぞれ独立に、ジヒドロキシベンゼンに由来する基であることが好ましく、１，２－ジヒドロキシベンゼン（カテコール）に由来する基、及び１，３－ジヒドロキシベンゼン（レゾルシノール）に由来する基からなる群より選ばれる少なくとも１種であることがより好ましい。さらに、硬化体の熱伝導性を特に高める観点から、Ａｒ３１～Ａｒ３４は、レゾルシノールに由来する基を少なくとも含むことが好ましい。
　また、硬化体の熱伝導性を特に高める観点から、含有数がｎ３１～ｎ３４で示される構造単位は、レゾルシノールに由来する部分構造を少なくとも含んでいることが好ましい。 Further, from the viewpoint of productivity and fluidity of the epoxy resin composition, Ar 31 to Ar 34 are preferably each independently a group derived from dihydroxybenzene, and derived from 1,2-dihydroxybenzene (catechol). More preferably, it is at least one selected from the group consisting of a group and a group derived from 1,3-dihydroxybenzene (resorcinol). Furthermore, Ar 31 to Ar 34 preferably include at least a group derived from resorcinol from the viewpoint of particularly improving the thermal conductivity of the cured body.
Further, from the viewpoint of particularly improving the thermal conductivity of the cured product, the structural unit represented by n31 to n34 preferably contains at least a partial structure derived from resorcinol.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物がレゾルシノールに由来する部分構造を含む場合、レゾルシノールに由来する部分構造の含有率は、上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）のうちの少なくとも１つで表される構造を有する化合物の総質量中において、５５質量％以上であることが好ましく、６０質量％以上であることがより好ましく、８０質量％以上であることがさらに好ましく、９０質量％以上であることが特に好ましい。 When the compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) includes a partial structure derived from resorcinol, the partial structure derived from resorcinol The content is preferably 55% by mass or more, based on the total mass of the compound having a structure represented by at least one of the general formulas (III-1) to (III-4), and 60% by mass. % Or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）におけるｍ３１～ｍ３４及びｎ３１～ｎ３４についてはそれぞれ、エポキシ樹脂組成物の流動性の観点から、ｍ／ｎ＝２０／１～１／５であることが好ましく、２０／１～５／１であることがより好ましく、２０／１～１０／１であることがさらに好ましい。また、（ｍ＋ｎ）は、エポキシ樹脂組成物の流動性の観点から２０以下であることが好ましく、１５以下であることがより好ましく、１０以下であることがさらに好ましい。なお、（ｍ＋ｎ）の下限値は特に制限されない。ここでｎがｎ３１の場合、ｍはｍ３１であり、ｎがｎ３２の場合、ｍはｍ３２であり、ｎがｎ３３の場合、ｍはｍ３３であり、ｎがｎ３４の場合、ｍはｍ３４である。 In the above general formulas (III-1) to (III-4), m31 to m34 and n31 to n34 are each m / n = 20/1 to 1/5 from the viewpoint of fluidity of the epoxy resin composition. It is preferably 20/1 to 5/1, more preferably 20/1 to 10/1. In addition, (m + n) is preferably 20 or less, more preferably 15 or less, and even more preferably 10 or less from the viewpoint of fluidity of the epoxy resin composition. In addition, the lower limit of (m + n) is not particularly limited. Here, when n is n31, m is m31, when n is n32, m is m32, when n is n33, m is m33, and when n is n34, m is m34.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物は、特にＡｒ３１～Ａｒ３４が置換又は非置換のジヒドロキシベンゼン及び置換又は非置換のジヒドロキシナフタレンの少なくともいずれか１種である場合、これらを単純にノボラック化したノボラック樹脂等と比較して、その合成が容易であり、軟化点の低いノボラック樹脂が得られる傾向にある。したがって、このようなノボラック樹脂を硬化剤として含むエポキシ樹脂組成物の製造及び取り扱いも容易になるという利点がある。
　なお、上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物は、電界脱離イオン化質量分析法（ＦＤ－ＭＳ）により、そのフラグメント成分として上記構造を特定することができる。 The compound having a structure represented by at least one selected from the group consisting of the above general formulas (III-1) to (III-4) is particularly a dihydroxybenzene in which Ar 31 to Ar 34 are substituted or unsubstituted and substituted Alternatively, in the case of at least one of unsubstituted dihydroxynaphthalene, compared to a novolak resin or the like obtained by simply novolacizing these, the synthesis thereof is easy, and a novolak resin having a low softening point tends to be obtained. . Therefore, there exists an advantage that manufacture and handling of the epoxy resin composition containing such a novolak resin as a hardening | curing agent also become easy.
A compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) is obtained by field desorption ionization mass spectrometry (FD-MS). The above structure can be specified as the fragment component.
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物の分子量は特に制限されない。エポキシ樹脂組成物の流動性の観点から、数平均分子量（Ｍｎ）としては２０００以下であることが好ましく、１５００以下であることがより好ましく、３５０～１５００であることがさらに好ましい。また、重量平均分子量（Ｍｗ）としては２０００以下であることが好ましく、１５００以下であることがより好ましく、４００～１５００であることがさらに好ましい。
　これらＭｎ及びＭｗは、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）を用いた通常の方法により測定される。 The molecular weight of the compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) is not particularly limited. From the viewpoint of fluidity of the epoxy resin composition, the number average molecular weight (Mn) is preferably 2000 or less, more preferably 1500 or less, and even more preferably 350 to 1500. The weight average molecular weight (Mw) is preferably 2000 or less, more preferably 1500 or less, and further preferably 400 to 1500.
These Mn and Mw are measured by a usual method using gel permeation chromatography (GPC).
　上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造を有する化合物の水酸基当量は特に制限されない。耐熱性に関与する架橋密度の観点から、水酸基当量は平均値で５０ｇ／ｅｑ～１５０ｇ／ｅｑであることが好ましく、５０ｇ／ｅｑ～１２０ｇ／ｅｑであることがより好ましく、５５ｇ／ｅｑ～１２０ｇ／ｅｑであることがさらに好ましい。 The hydroxyl equivalent of the compound having a structure represented by at least one selected from the group consisting of the general formulas (III-1) to (III-4) is not particularly limited. From the viewpoint of the crosslinking density involved in heat resistance, the hydroxyl group equivalent is preferably 50 g / eq to 150 g / eq on average, more preferably 50 g / eq to 120 g / eq, and 55 g / eq to 120 g / eq. More preferably, it is eq.
　エポキシ樹脂組成物中における硬化剤の含有率は特に制限されないが、硬化体の熱伝導性の観点から、エポキシ樹脂組成物中に１質量％～１５質量％であることが好ましく、１質量％～１０質量％であることがより好ましい。また、硬化剤におけるフェノール性水酸基の当量数とエポキシ樹脂モノマーにおけるエポキシ基の当量数との比（フェノール性水酸基の当量数／エポキシ基の当量数）が０．５～２となることが好ましく、０．８～１．２となることがより好ましい。 The content of the curing agent in the epoxy resin composition is not particularly limited, but is preferably 1% by mass to 15% by mass in the epoxy resin composition from the viewpoint of thermal conductivity of the cured product. More preferably, it is 10 mass%. The ratio of the number of equivalents of phenolic hydroxyl groups in the curing agent and the number of equivalents of epoxy groups in the epoxy resin monomer (the number of equivalents of phenolic hydroxyl groups / the number of equivalents of epoxy groups) is preferably 0.5 to 2. More preferably, it is 0.8 to 1.2.
（エポキシ樹脂モノマーのオリゴマー体）
　本開示のエポキシ樹脂組成物は、上記メソゲン骨格を有するエポキシ樹脂モノマーのオリゴマー体を含有する。特に本開示のエポキシ樹脂組成物は、上記オリゴマー体として、上記メソゲン骨格を有するエポキシ樹脂モノマーと硬化剤である上記ノボラック樹脂との反応物を含む。当該反応物を含有することにより、硬化体の熱伝導性が向上する。なお、上記オリゴマー体には、メソゲン骨格を有するエポキシ樹脂モノマーの単独重合体がさらに含まれていてもよい。 (Epoxy resin monomer oligomer)
The epoxy resin composition of the present disclosure contains an oligomer of an epoxy resin monomer having the mesogen skeleton. In particular, the epoxy resin composition of the present disclosure includes a reaction product of the epoxy resin monomer having the mesogen skeleton and the novolak resin as a curing agent as the oligomer. By containing the reactant, the thermal conductivity of the cured body is improved. The oligomer may further contain a homopolymer of an epoxy resin monomer having a mesogen skeleton.
　上記オリゴマー体は、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）測定における重量平均分子量（Ｍｗ）が１０００～３０００である。重量平均分子量（Ｍｗ）が上記範囲であることにより、常温でも柔軟性を有し、かつ硬化体が高熱伝導性を有するエポキシ樹脂組成物を得ることができる傾向にある。重量平均分子量（Ｍｗ）が１０００未満であると常温での柔軟性が失われる傾向にあり、３０００を超えると常温での柔軟性のみならず、後述の積層板を作製する際に被着材との接着性も失われる傾向にある。重量平均分子量（Ｍｗ）は１２００～２８００であることがより好ましく、１５００～２５００であることがさらに好ましい。 The oligomer body has a weight average molecular weight (Mw) of 1000 to 3000 as measured by gel permeation chromatography (GPC). When the weight average molecular weight (Mw) is in the above range, there is a tendency that an epoxy resin composition having flexibility even at room temperature and having a cured product having high thermal conductivity can be obtained. When the weight average molecular weight (Mw) is less than 1000, the flexibility at room temperature tends to be lost. When the weight average molecular weight (Mw) exceeds 3000, not only the flexibility at room temperature but also the adherend when producing a laminate as described below. There is also a tendency for the adhesion of the resin to be lost. The weight average molecular weight (Mw) is more preferably 1200 to 2800, and further preferably 1500 to 2500.
　なお、上記オリゴマー体の重量平均分子量（Ｍｗ）は、次のようにして測定される。まず、エポキシ樹脂組成物をテトラヒドロフラン（ＴＨＦ）中に浸漬し、半日（１２時間）放置する。その後、ＴＨＦ可溶分を０．４５μｍメンブランフィルターにて濾過し、濾液について後述する実施例記載の測定条件にてＧＰＣ測定を行う。そして、エポキシ樹脂モノマーのピークよりも早い時間に検出されたピーク（いわゆる、該エポキシ樹脂モノマーより高分子量である物質）の重量平均分子量を求めた解析結果を、オリゴマー体の重量平均分子量とする。 In addition, the weight average molecular weight (Mw) of the said oligomer body is measured as follows. First, the epoxy resin composition is immersed in tetrahydrofuran (THF) and left for half a day (12 hours). Thereafter, the THF-soluble matter is filtered through a 0.45 μm membrane filter, and GPC measurement is performed under the measurement conditions described in the Examples described later for the filtrate. And the analysis result which calculated | required the weight average molecular weight of the peak (what is called a substance higher molecular weight than this epoxy resin monomer) detected at the time earlier than the peak of an epoxy resin monomer is made into the weight average molecular weight of an oligomer body.
　エポキシ樹脂組成物中におけるオリゴマー体の含有率は特に制限されない。常温での柔軟性及び硬化体の熱伝導性の観点から、オリゴマー体の含有率は、エポキシ樹脂組成物中に１質量％～５質量％であることが好ましく、２質量％～３．５質量％であることがより好ましい。 The content of the oligomer in the epoxy resin composition is not particularly limited. From the viewpoint of flexibility at normal temperature and the thermal conductivity of the cured product, the content of the oligomer is preferably 1% by mass to 5% by mass in the epoxy resin composition, and 2% by mass to 3.5% by mass. % Is more preferable.
（無機フィラー）
　本開示のエポキシ樹脂組成物は、無機フィラーの少なくとも１種類を含有する。無機フィラーを含有することにより、硬化体について高熱伝導性を達成することができる。
　無機フィラーは非導電性であっても導電性であってもよい。非導電性の無機フィラーを使用することによって、硬化体の電気絶縁性の低下を抑制することができる。また、導電性の無機フィラーを使用することによって、硬化体の熱伝導性がより向上する。 (Inorganic filler)
The epoxy resin composition of the present disclosure contains at least one inorganic filler. By containing an inorganic filler, high thermal conductivity can be achieved for the cured body.
The inorganic filler may be non-conductive or conductive. By using a non-conductive inorganic filler, it is possible to suppress a decrease in electrical insulation of the cured body. Moreover, the heat conductivity of a hardening body improves more by using a conductive inorganic filler.
　非導電性の無機フィラーとして、具体的には、アルミナ、窒化ホウ素、シリカ、酸化マグネシウム、窒化アルミニウム、マイカ、酸化ケイ素、水酸化アルミニウム、硫酸バリウム等の粒子が挙げられる。また、導電性の無機フィラーとしては、金、銀、ニッケル、銅、黒鉛等の粒子が挙げられる。中でも、熱伝導性及び電気絶縁性の観点から、アルミナ、窒化ホウ素、シリカ、酸化マグネシウム、窒化アルミニウム、及びマイカからなる群より選択される少なくとも１つの粒子であることが好ましい。アルミナにはα－アルミナ、γ－アルミナ、δ－アルミナ、θ－アルミナ等が存在するが、熱伝導性の観点から、α－アルミナが好ましい。なお、アルミナフィラーにおけるα－アルミナの存在は、Ｘ線回折スペクトルによって確認することができる。具体的には、特許第３７５９２０８号公報の記載に準じて、α－アルミナに特有のピークを指標としてα－アルミナの存在を確認することができる。 Specific examples of the non-conductive inorganic filler include particles of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, mica, silicon oxide, aluminum hydroxide, barium sulfate, and the like. Examples of the conductive inorganic filler include particles such as gold, silver, nickel, copper, and graphite. Among these, at least one particle selected from the group consisting of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, and mica is preferable from the viewpoint of thermal conductivity and electrical insulation. Alumina includes α-alumina, γ-alumina, δ-alumina, θ-alumina, etc., and α-alumina is preferable from the viewpoint of thermal conductivity. The presence of α-alumina in the alumina filler can be confirmed by an X-ray diffraction spectrum. Specifically, according to the description in Japanese Patent No. 3759208, the presence of α-alumina can be confirmed using a peak peculiar to α-alumina as an index.
　これらの無機フィラーは、１種類又は２種類以上の混合系で用いることができる。２種類以上の混合系の場合、例えば、アルミナフィラーと窒化ホウ素フィラーとを併用することができるが、この組み合わせに限定されるものではない。 These inorganic fillers can be used in one kind or a mixed system of two or more kinds. In the case of two or more types of mixed systems, for example, an alumina filler and a boron nitride filler can be used in combination, but the combination is not limited to this.
　上記無機フィラーは、横軸に粒子径を、縦軸に頻度をとった粒度分布曲線を描いた場合に、単一のピークを有していてもよく、複数のピークを有していてもよい。粒度分布曲線が複数のピークを有する無機フィラーを用いることで、無機フィラーの充填性が向上し、熱伝導性が向上する。 The inorganic filler may have a single peak or a plurality of peaks when a particle size distribution curve having a particle diameter on the horizontal axis and a frequency on the vertical axis is drawn. . By using the inorganic filler having a plurality of peaks in the particle size distribution curve, the filling property of the inorganic filler is improved and the thermal conductivity is improved.
　上記無機フィラーが粒度分布曲線を描いたときに単一のピークを有する場合、無機フィラーの重量累積粒度分布の小粒径側からの累積５０％に対応する粒子径である平均粒子径（Ｄ５０）は、熱伝導性の観点から、０．１μｍ～１００μｍであることが好ましく、０．１μｍ～５０μｍであることがより好ましい。また、粒度分布曲線が複数のピークを有する場合は、例えば、異なる平均粒子径を有する２種類以上の無機フィラーを組み合わせて構成できる。 When the inorganic filler has a single peak when drawing a particle size distribution curve, the average particle size (D50) which is a particle size corresponding to 50% cumulative from the small particle size side of the weight cumulative particle size distribution of the inorganic filler Is preferably from 0.1 μm to 100 μm, more preferably from 0.1 μm to 50 μm from the viewpoint of thermal conductivity. Moreover, when a particle size distribution curve has a some peak, it can comprise, for example in combination of 2 or more types of inorganic fillers which have a different average particle diameter.
　本開示において、無機フィラーの平均粒子径はレーザー回折法を用いて測定され、重量累積粒度分布曲線を小粒径側から描いた場合に、重量累積が５０％となる粒子径に対応する。レーザー回折法を用いた粒度分布測定は、レーザー回折散乱粒度分布測定装置（例えば、ベックマン・コールター株式会社製、ＬＳ２３０）を用いて行うことができる。 In the present disclosure, the average particle diameter of the inorganic filler is measured using a laser diffraction method, and corresponds to a particle diameter at which the weight accumulation is 50% when the weight accumulation particle size distribution curve is drawn from the small particle diameter side. The particle size distribution measurement using the laser diffraction method can be performed using a laser diffraction scattering particle size distribution measuring device (for example, LS230, manufactured by Beckman Coulter, Inc.).
　上記無機フィラーの組み合わせについて、例えば、異なる平均粒子径を有する２種類の無機フィラーを組み合わせる場合を挙げると、平均粒子径が１０μｍ～１００μｍである無機フィラー（Ａ）と、平均粒子径が無機フィラー（Ａ）の１／２以下であり、０．１μｍ以上１０μｍ未満である無機フィラー（Ｂ）との混合フィラーを挙げることができる。上記混合フィラーは、無機フィラーの全体積を基準（１００体積％）として、無機フィラー（Ａ）が６０体積％～９０体積％、無機フィラー（Ｂ）が１０体積％～４０体積％（ただし、無機フィラー（Ａ）及び（Ｂ）の総体積％は１００体積％である）の割合であると好適である。 As for the combination of the above inorganic fillers, for example, when two types of inorganic fillers having different average particle diameters are combined, an inorganic filler (A) having an average particle diameter of 10 μm to 100 μm and an inorganic filler ( A mixed filler with an inorganic filler (B) which is 1/2 or less of A) and is 0.1 μm or more and less than 10 μm can be mentioned. The above mixed filler is based on the total volume of the inorganic filler (100% by volume), the inorganic filler (A) is 60% to 90% by volume, and the inorganic filler (B) is 10% to 40% by volume (however, inorganic The total volume% of the fillers (A) and (B) is preferably 100% by volume).
　なお、このときの無機フィラーは、同一であっても異なっていてもよい。例えば、無機フィラー（Ａ）及び（Ｂ）がともにアルミナフィラーであってもよいし、無機フィラー（Ａ）がアルミナフィラーであり、無機フィラー（Ｂ）が窒化ホウ素フィラーであってもよい。 In addition, the inorganic filler at this time may be the same or different. For example, both the inorganic fillers (A) and (B) may be alumina fillers, the inorganic filler (A) may be an alumina filler, and the inorganic filler (B) may be a boron nitride filler.
　また、異なる平均粒子径を有する３種類の無機フィラーを組み合わせる場合を挙げると、平均粒子径が１０μｍ～１００μｍである無機フィラー（Ａ’）と、平均粒子径が無機フィラー（Ａ’）の１／２以下であり、１μｍ以上１０μｍ未満である無機フィラー（Ｂ’）と、平均粒子径が無機フィラー（Ｂ’）の１／２以下であり、０．１μｍ以上１μｍ未満である無機フィラー（Ｃ’）との混合フィラーを挙げることができる。上記混合フィラーは、無機フィラーの全体積を基準（１００体積％）として、無機フィラー（Ａ’）が３０体積％～８９体積％、無機フィラー（Ｂ’）が１０体積％～以上４０体積％、無機フィラー（Ｃ’）が１体積％～３０体積％（ただし、無機フィラー（Ａ’）、（Ｂ’）、及び（Ｃ’）の総体積％は１００体積％である）の割合であると好適である。 Further, when three types of inorganic fillers having different average particle sizes are combined, an inorganic filler (A ′) having an average particle size of 10 μm to 100 μm and an average particle size of 1 / of the inorganic filler (A ′). An inorganic filler (B ′) that is 2 or less, 1 μm or more and less than 10 μm, and an inorganic filler (C ′ that has an average particle diameter of ½ or less of the inorganic filler (B ′) and is 0.1 μm or more and less than 1 μm. And a mixed filler. The above mixed filler is based on the total volume of the inorganic filler (100% by volume), the inorganic filler (A ′) is 30% by volume to 89% by volume, the inorganic filler (B ′) is 10% by volume to 40% by volume, The proportion of the inorganic filler (C ′) is 1% by volume to 30% by volume (provided that the total volume% of the inorganic fillers (A ′), (B ′), and (C ′) is 100% by volume) Is preferred.
　なお、このときの無機フィラーは、同一であっても異なっていてもよい。例えば、無機フィラー（Ａ’）、（Ｂ’）、及び（Ｃ’）がいずれもアルミナフィラーであってもよいし、無機フィラー（Ａ’）が窒化ホウ素フィラーであり、無機フィラー（Ｂ’）及び（Ｃ’）がともにアルミナフィラーであってもよい。 In addition, the inorganic filler at this time may be the same or different. For example, the inorganic fillers (A ′), (B ′), and (C ′) may all be alumina fillers, the inorganic filler (A ′) is a boron nitride filler, and the inorganic filler (B ′). And (C ′) may both be alumina fillers.
　上記無機フィラー（Ａ）及び（Ａ’）の平均粒子径は、エポキシ樹脂組成物を後述の樹脂シートに適用する場合には、目標とする樹脂シートにおける硬化体の膜厚に、また、エポキシ樹脂組成物を後述のプリプレグに適用する場合には、目標とするプリプレグの膜厚及び繊維素材の目の細かさに、それぞれ応じて適宜選択されることが好ましい。 The average particle diameter of the inorganic fillers (A) and (A ′) is the thickness of the cured product in the target resin sheet and the epoxy resin when the epoxy resin composition is applied to a resin sheet described later. When the composition is applied to a prepreg described later, it is preferable that the composition is appropriately selected according to the target film thickness of the prepreg and the fineness of the fiber material.
　他の制限が特にない場合、熱伝導性の観点から、上記無機フィラー（Ａ）及び（Ａ’）の平均粒子径は大きいほど好ましい。一方、熱抵抗の観点から、上記膜厚は電気絶縁性が許容する範囲でなるべく薄くすることが好ましい。よって、上記無機フィラー（Ａ）及び（Ａ’）の平均粒子径は１０μｍ～１００μｍであることが好ましく、無機フィラーの充填性、熱抵抗、及び熱伝導性の観点から、１０μｍ～８０μｍであることがより好ましく、１０μｍ～５０μｍであることがさらに好ましい。 When there is no other limitation, the average particle diameter of the inorganic fillers (A) and (A ′) is preferably as large as possible from the viewpoint of thermal conductivity. On the other hand, from the viewpoint of thermal resistance, the film thickness is preferably as thin as possible within the range allowed by electrical insulation. Therefore, the average particle size of the inorganic fillers (A) and (A ′) is preferably 10 μm to 100 μm, and from the viewpoint of the filling properties, thermal resistance, and thermal conductivity of the inorganic filler, it is 10 μm to 80 μm. Is more preferably 10 μm to 50 μm.
　エポキシ樹脂組成物中の無機フィラーの含有率は特に制限されない。熱伝導性及び成形性の観点から、無機フィラーの含有率は、エポキシ樹脂組成物の全体積を１００体積％とした場合に、６０体積％～９０体積％であることが好ましく、７０体積％～９０体積％であることがより好ましい。無機フィラーの含有率が６０体積％以上であることで、硬化体についてより高い熱伝導性を達成することができ、一方、９０体積％以下であることで、成形性に優れたエポキシ樹脂組成物を得ることができる。 The content of the inorganic filler in the epoxy resin composition is not particularly limited. From the viewpoint of thermal conductivity and moldability, the content of the inorganic filler is preferably 60% by volume to 90% by volume when the total volume of the epoxy resin composition is 100% by volume, preferably 70% by volume to More preferably, it is 90 volume%. When the content of the inorganic filler is 60% by volume or more, a higher thermal conductivity can be achieved for the cured body, while when it is 90% by volume or less, an epoxy resin composition having excellent moldability. Can be obtained.
　なお、エポキシ樹脂組成物中の無機フィラーの含有率（体積％）は、アルキメデス法によって測定したエポキシ樹脂組成物及び無機フィラーの体積に基づいて算出することができる。 The content (volume%) of the inorganic filler in the epoxy resin composition can be calculated based on the volume of the epoxy resin composition and the inorganic filler measured by the Archimedes method.
　また、本開示のエポキシ樹脂組成物は、必要に応じてナノ粒子サイズの無機フィラー（例えば、平均粒子径が１ｎｍ～１００ｎｍである無機フィラー）をさらに含んでいてもよい。 In addition, the epoxy resin composition of the present disclosure may further include a nanoparticle-sized inorganic filler (for example, an inorganic filler having an average particle diameter of 1 nm to 100 nm) as necessary.
　マイクロ粒子サイズ（平均粒子径が１μｍ以上）の無機フィラーを高充填すると、無機フィラーの表面とエポキシ樹脂との相互作用により粘度が著しく上昇し、これによって空気を巻き込んで気泡を内包し易くなる場合、又は無機フィラー同士が嵌合する頻度が高くなり、流動性が著しく低下する場合がある。これらの課題に対する解決策として、ナノ粒子サイズの無機フィラーを少量添加する方法が挙げられ、このことは特開２００９－１３２２７号公報にも示されている。 When inorganic fillers with a micro particle size (average particle diameter of 1 μm or more) are highly filled, the viscosity rises significantly due to the interaction between the surface of the inorganic filler and the epoxy resin, which makes it easy to enclose air bubbles by entraining air. Alternatively, the frequency with which inorganic fillers are fitted to each other is increased, and the fluidity may be significantly reduced. As a solution to these problems, there is a method of adding a small amount of nano-sized inorganic filler, which is also disclosed in Japanese Patent Application Laid-Open No. 2009-13227.
　本開示のエポキシ樹脂組成物が平均粒子径が１ｎｍ～１００ｎｍである無機フィラーを含有する場合、その含有率は特に制限はない。平均粒子径が１ｎｍ～１００ｎｍである無機フィラーの含有率は、エポキシ樹脂組成物の全体積を１００体積％とした場合に、０．０１体積％～１体積％であることが好ましく、０．０１体積％～０．５体積％であることがより好ましい。エポキシ樹脂組成物の全体積中の０．０１体積％～１体積％で含有されることで、マイクロ粒子サイズの無機フィラー間、及びマイクロ粒子サイズの無機フィラーと後述する繊維基材との間の潤滑性をより高め、かつエポキシ樹脂組成物の硬化体の熱伝導性をより高める効果が期待できる。 When the epoxy resin composition of the present disclosure contains an inorganic filler having an average particle diameter of 1 nm to 100 nm, the content is not particularly limited. The content of the inorganic filler having an average particle diameter of 1 nm to 100 nm is preferably 0.01% by volume to 1% by volume when the total volume of the epoxy resin composition is 100% by volume, More preferably, the volume is from 0.5% to 0.5% by volume. By containing 0.01 vol% to 1 vol% of the total volume of the epoxy resin composition, between the microparticle size inorganic filler and between the microparticle size inorganic filler and the fiber substrate described later The effect which raises lubricity more and raises the heat conductivity of the hardening body of an epoxy resin composition more can be anticipated.
（硬化促進剤）
　本開示のエポキシ樹脂組成物は、必要に応じて硬化促進剤をさらに含有していてもよい。硬化促進剤をさらに含むことでエポキシ樹脂組成物をさらに十分に硬化させることができる。硬化促進剤の種類及び含有率は特に限定されず、反応速度、反応温度、保管性等の観点から、適切な種類及び含有率を選択することができる。硬化促進剤の具体例としては、イミダゾール系化合物、有機リン系化合物、第３級アミン、第４級アンモニウム塩等が挙げられる。
　中でも、耐熱性の観点から、有機ホスフィン化合物、及び有機ホスフィン化合物と有機ボロン化合物との錯体からなる群より選択される少なくとも１つであることが好ましい。 (Curing accelerator)
The epoxy resin composition of the present disclosure may further contain a curing accelerator as necessary. By further including a curing accelerator, the epoxy resin composition can be further sufficiently cured. The type and content of the curing accelerator are not particularly limited, and an appropriate type and content can be selected from the viewpoint of reaction rate, reaction temperature, storage property, and the like. Specific examples of the curing accelerator include imidazole compounds, organic phosphorus compounds, tertiary amines, quaternary ammonium salts, and the like.
Among these, from the viewpoint of heat resistance, it is preferably at least one selected from the group consisting of an organic phosphine compound and a complex of an organic phosphine compound and an organic boron compound.
　有機ホスフィン化合物としては、具体的には、トリフェニルホスフィン、ジフェニル（ｐ－トリル）ホスフィン、トリス（アルキルフェニル）ホスフィン、トリス（アルコキシフェニル）ホスフィン、トリス（アルキルアルコキシフェニル）ホスフィン、トリス（ジアルキルフェニル）ホスフィン、トリス（トリアルキルフェニル）ホスフィン、トリス（テトラアルキルフェニル）ホスフィン、トリス（ジアルコキシフェニル）ホスフィン、トリス（トリアルコキシフェニル）ホスフィン、トリス（テトラアルコキシフェニル）ホスフィン、トリアルキルホスフィン、ジアルキルアリールホスフィン、アルキルジアリールホスフィン等が挙げられる。 Specific examples of the organic phosphine compound include triphenylphosphine, diphenyl (p-tolyl) phosphine, tris (alkylphenyl) phosphine, tris (alkoxyphenyl) phosphine, tris (alkylalkoxyphenyl) phosphine, and tris (dialkylphenyl). Phosphine, tris (trialkylphenyl) phosphine, tris (tetraalkylphenyl) phosphine, tris (dialkoxyphenyl) phosphine, tris (trialkoxyphenyl) phosphine, tris (tetraalkoxyphenyl) phosphine, trialkylphosphine, dialkylarylphosphine, Examples thereof include alkyl diaryl phosphine.
　また、有機ホスフィン化合物と有機ボロン化合物との錯体としては、具体的には、テトラフェニルホスホニウムテトラフェニルボレート、テトラフェニルホスホニウムテトラ－ｐ－トリルボレート、テトラブチルホスホニウムテトラフェニルボレート、テトラフェニルホスホニウムｎ－ブチルトリフェニルボレート、ブチルトリフェニルホスホニウムテトラフェニルボレート、メチルトリブチルホスホニウムテトラフェニルボレート等が挙げられる。 Specific examples of complexes of organic phosphine compounds and organic boron compounds include tetraphenylphosphonium tetraphenylborate, tetraphenylphosphonium tetra-p-tolylborate, tetrabutylphosphonium tetraphenylborate, and tetraphenylphosphonium n-butyl. Examples thereof include triphenyl borate, butyl triphenyl phosphonium tetraphenyl borate, and methyl tributyl phosphonium tetraphenyl borate.
　硬化促進剤は１種単独で使用してもよく、２種以上を併用してもよい。２種以上の硬化促進剤を併用する場合、例えば、エポキシ樹脂モノマーとノボラック樹脂との反応開始温度及び反応速度が異なる２種類の硬化促進剤を混合して用いる方法が挙げられる。 A hardening accelerator may be used individually by 1 type, and may use 2 or more types together. When using 2 or more types of hardening accelerators together, the method of mixing and using 2 types of hardening accelerators from which the reaction start temperature and reaction rate of an epoxy resin monomer and a novolak resin differ, for example is mentioned.
　２種以上の硬化促進剤を併用する場合、硬化促進剤の混合割合は本開示のエポキシ樹脂組成物に求める特性（例えば、どの程度の柔軟性を必要とするか）によって特に制限されることなく決めることができる。 When two or more kinds of curing accelerators are used in combination, the mixing ratio of the curing accelerators is not particularly limited by the characteristics (for example, how much flexibility is required) required for the epoxy resin composition of the present disclosure. I can decide.
　本開示のエポキシ樹脂組成物が硬化促進剤を含有する場合、その含有率は特に制限されない。成形性の観点から、硬化促進剤の含有率は、エポキシ樹脂モノマーと硬化剤との合計質量に対して０．５質量％～１．５質量％であることが好ましく、０．５質量％～１質量％であることがより好ましく、０．７５質量％～１質量％であることがさらに好ましい。 When the epoxy resin composition of the present disclosure contains a curing accelerator, the content is not particularly limited. From the viewpoint of moldability, the content of the curing accelerator is preferably 0.5% by mass to 1.5% by mass, and preferably 0.5% by mass to 0.5% by mass with respect to the total mass of the epoxy resin monomer and the curing agent. The content is more preferably 1% by mass, and further preferably 0.75% by mass to 1% by mass.
（シランカップリング剤）
　本開示のエポキシ樹脂組成物は、シランカップリング剤の少なくとも１種をさらに含有することが好ましい。シランカップリング剤を含有させる効果としては、無機フィラーの表面とその周りを取り囲むエポキシ樹脂との間で共有結合を形成する役割（バインダ剤に相当）を果たし、熱をより効率良く伝達する効果、及び水分の浸入を妨げることによって絶縁信頼性を向上させる効果を挙げることができる。 (Silane coupling agent)
The epoxy resin composition of the present disclosure preferably further contains at least one silane coupling agent. As an effect of containing a silane coupling agent, it plays the role of forming a covalent bond between the surface of the inorganic filler and the epoxy resin surrounding it (equivalent to the binder agent), and the effect of transferring heat more efficiently, Moreover, the effect of improving the insulation reliability can be obtained by preventing the intrusion of moisture.
　シランカップリング剤の種類としては特に限定されず、市販のものから適宜選択することができる。メソゲン骨格を有するエポキシ樹脂モノマー及び硬化剤との相溶性、並びにエポキシ樹脂と無機フィラーとの界面での熱伝導欠損を低減させることを考慮すると、末端にエポキシ基、アミノ基、メルカプト基、ウレイド基、及び水酸基からなる群より選ばれる少なくとも１種の官能基を有するシランカップリング剤を用いることが好適である。 The type of the silane coupling agent is not particularly limited and can be appropriately selected from commercially available ones. Considering compatibility with epoxy resin monomer and curing agent having mesogenic skeleton and reducing heat conduction deficiency at the interface between epoxy resin and inorganic filler, terminal epoxy group, amino group, mercapto group, ureido group And a silane coupling agent having at least one functional group selected from the group consisting of hydroxyl groups.
　シランカップリング剤の具体例としては、３－グリシドキシプロピルトリメトキシシラン、３－グリシドキシプロピルトリエトキシシラン、３－グリシドキシプロピルメチルジエトキシシラン、３－グリシドキシプロピルメチルジメトキシシラン、２－（３，４－エポキシシクロヘキシル）エチルトリメトキシシラン等のエポキシ基を有するシランカップリング剤；３－アミノプロピルトリエトキシシラン、３－（２－アミノエチル）アミノプロピルトリメトキシシラン、３－（２－アミノエチル）アミノプロピルトリメトキシシラン、３－アミノプロピルトリメトキシシラン、３－フェニルアミノプロピルトリメトキシシラン等のアミノ基を有するシランカップリング剤；３－メルカプトプロピルトリメトキシシラン、３－メルカプトトリエトキシシラン等のメルカプト基を有するシランカップリング剤；３－ウレイドプロピルトリエトキシシラン等のウレイド基を有するシランカップリング剤；などが挙げられる。また、ＳＣ－６０００ＫＳ２に代表されるシランカップリング剤オリゴマー（日立化成テクノサービス株式会社製）をさらに挙げることもできる。これらのシランカップリング剤は１種単独で使用してもよく、２種以上を併用してもよい。 Specific examples of the silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropylmethyldimethoxysilane. Silane coupling agents having an epoxy group such as 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane; 3-aminopropyltriethoxysilane, 3- (2-aminoethyl) aminopropyltrimethoxysilane, 3- Silane coupling agents having an amino group such as (2-aminoethyl) aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-phenylaminopropyltrimethoxysilane; 3-mercaptopropyltrimethoxysilane, 3-mercapto G Silane coupling agent having a ureido group such as 3-ureidopropyltriethoxysilane; silane coupling agent having a mercapto group such as silane, and the like. Further, silane coupling agent oligomers (manufactured by Hitachi Chemical Techno Service Co., Ltd.) represented by SC-6000KS2 can also be mentioned. These silane coupling agents may be used alone or in combination of two or more.
（その他の成分）
　本開示のエポキシ樹脂組成物は、上記成分に加え、必要に応じてその他の成分を含むことができる。その他の成分としては、分散剤等が挙げられる。分散剤としては、味の素ファインテック株式会社製アジスパーシリーズ、楠本化成株式会社製ＨＩＰＬＡＡＤシリーズ、株式会社花王製ホモゲノールシリーズ等が挙げられる。これらは１種単独で使用してもよく、２種以上を併用してもよい。 (Other ingredients)
The epoxy resin composition of the present disclosure can contain other components as necessary in addition to the above components. Examples of other components include a dispersant. Examples of the dispersant include Ajinomoto Finetech Co., Ltd. Ajisper series, Enomoto Kasei Co., Ltd. HIPLAAD series, Kao Corporation homogenol series, and the like. These may be used alone or in combination of two or more.
（エポキシ樹脂組成物の特性）
　本開示のエポキシ樹脂組成物は、エポキシ樹脂モノマーと硬化剤であるノボラック樹脂との間の硬化反応が部分的に進行したものである。このようなエポキシ樹脂組成物は、例えば、これをシート状に成形した場合に、硬化反応が進行していないエポキシ樹脂組成物からなる樹脂シートに比べて取り扱い性が向上する。 (Characteristics of epoxy resin composition)
In the epoxy resin composition of the present disclosure, the curing reaction between the epoxy resin monomer and the novolak resin as the curing agent partially proceeds. For example, when such an epoxy resin composition is molded into a sheet shape, the handleability is improved as compared with a resin sheet made of an epoxy resin composition in which the curing reaction has not progressed.
　本開示のエポキシ樹脂組成物は、示差走査熱量（ＤＳＣ）測定における吸熱ピーク面積が２．０Ｊ／ｇ以下であり、４ｃｍ×４ｃｍ×１５０μｍのサンプルを１９０℃の恒温槽で２時間加熱したときの熱重量減少率が０．４質量％以下であることが、常温での柔軟性、かつ硬化体の高熱伝導性の観点より必要である。 The epoxy resin composition of the present disclosure has an endothermic peak area of 2.0 J / g or less in differential scanning calorimetry (DSC) measurement, and a sample of 4 cm × 4 cm × 150 μm is heated in a thermostat at 190 ° C. for 2 hours. The thermal weight reduction rate is 0.4% by mass or less from the viewpoints of flexibility at normal temperature and high thermal conductivity of the cured body.
　エポキシ樹脂組成物の示差走査熱量（ＤＳＣ）測定は、例えば、パーキンエルマー製の示差走査熱量測定装置を用いて行うことができる。測定で得られたデータの吸熱ピークの面積を、測定に用いたサンプルの質量で割った値が２．５Ｊ／ｇ以下であることで、常温でも柔軟性を有するエポキシ樹脂組成物を得ることができる。この吸熱ピーク面積は２．３Ｊ／ｇ以下であることがより好ましく、２．０Ｊ／ｇ以下であることがさらに好ましい。 The differential scanning calorimetry (DSC) measurement of the epoxy resin composition can be performed using, for example, a differential scanning calorimeter manufactured by PerkinElmer. The value obtained by dividing the endothermic peak area of the data obtained by the measurement by the mass of the sample used for the measurement is 2.5 J / g or less, so that an epoxy resin composition having flexibility even at room temperature can be obtained. it can. The endothermic peak area is more preferably 2.3 J / g or less, and further preferably 2.0 J / g or less.
　示差走査熱量（ＤＳＣ）測定での吸熱ピークの面積は、エポキシ樹脂組成物中に存在する結晶状態のエポキシ樹脂モノマーの量を反映している。よって、該エポキシ樹脂モノマーが全て溶融状態で存在していれば吸熱ピークは見られない。このことから、本開示のエポキシ樹脂組成物は吸熱ピークが見られない（０Ｊ／ｇ）ことが特に好ましいが、吸熱ピークの面積が２．５Ｊ／ｇ以下であれば、常温で十分に柔軟性を有する。 The area of the endothermic peak in differential scanning calorimetry (DSC) measurement reflects the amount of crystalline epoxy resin monomer present in the epoxy resin composition. Therefore, if all the epoxy resin monomers are present in a molten state, no endothermic peak is observed. Accordingly, it is particularly preferable that the epoxy resin composition of the present disclosure does not show an endothermic peak (0 J / g). However, if the area of the endothermic peak is 2.5 J / g or less, the epoxy resin composition is sufficiently flexible at room temperature. Have
　また、本開示のエポキシ樹脂組成物の熱重量減少率は、例えば、４ｃｍ×４ｃｍ×１５０μｍのサンプルを１９０℃に設定した恒温槽で２時間加熱し、加熱前後のサンプルの質量から計算することで求める。
　すなわち、エポキシ樹脂組成物の熱重量減少率（質量％）＝｛（加熱前のサンプル質量－加熱後のサンプル質量）／加熱前のサンプル質量｝×１００で求められる。
　これにより求めた値が０．４質量％以下であれば、高熱伝導性の硬化体が得られる。この熱重量減少率は０．３５質量％以下であることがより好ましく、０．３質量％以下であることがさらに好ましい。 Further, the thermal weight reduction rate of the epoxy resin composition of the present disclosure is calculated by, for example, heating a sample of 4 cm × 4 cm × 150 μm in a thermostatic bath set at 190 ° C. for 2 hours and calculating from the mass of the sample before and after heating. Ask.
That is, the thermal weight reduction rate (mass%) of the epoxy resin composition = {(sample mass before heating−sample mass after heating) / sample mass before heating} × 100.
If the value calculated | required by this is 0.4 mass% or less, a highly heat conductive hardening body will be obtained. The thermal weight loss rate is more preferably 0.35% by mass or less, and further preferably 0.3% by mass or less.
　エポキシ樹脂組成物を加熱することにより、エポキシ樹脂組成物中に存在している溶剤、反応に関与しない低分子量体等が揮発する。この揮発分がエポキシ樹脂組成物中に大量に存在していると、硬化時に高次構造の形成が阻害されてしまい、高い熱伝導率が得られなくなる。高次構造の形成を阻害しないために、熱重量減少率が０．４質量％以下であることが必要である。
　なお、熱重量減少率の測定では、サンプルを１９０℃に設定した恒温槽で２時間加熱するため、サンプルの厚みが１００μｍ～２００μｍの範囲であれば同程度の熱重量減少率となる。したがって、熱重量減少率の測定に用いるサンプルの厚みは、厳密に１５０μｍである必要はなく、１００μｍ～２００μｍの範囲であればよい。 By heating the epoxy resin composition, the solvent present in the epoxy resin composition, the low molecular weight substance not involved in the reaction, and the like are volatilized. If this volatile component is present in a large amount in the epoxy resin composition, formation of a higher order structure is inhibited during curing, and high thermal conductivity cannot be obtained. In order not to inhibit the formation of the higher order structure, it is necessary that the thermal weight reduction rate is 0.4% by mass or less.
In the measurement of the thermogravimetric reduction rate, the sample is heated in a thermostat set at 190 ° C. for 2 hours, so that the thermogravimetric reduction rate is comparable when the thickness of the sample is in the range of 100 μm to 200 μm. Therefore, the thickness of the sample used for measuring the thermal weight loss rate does not need to be strictly 150 μm, and may be in the range of 100 μm to 200 μm.
　また、本開示のエポキシ樹脂組成物は、常温での柔軟性及び硬化体の熱伝導性の観点から、示差走査熱量（ＤＳＣ）測定における発熱ピーク面積が１２．８Ｊ／ｇ～２０．５Ｊ／ｇであることが好ましい。示差走査熱量（ＤＳＣ）測定での発熱ピークは、エポキシ樹脂組成物中に存在する未反応のエポキシ樹脂モノマー及び硬化剤の量を反映している。 In addition, the epoxy resin composition of the present disclosure has an exothermic peak area in differential scanning calorimetry (DSC) measurement of 12.8 J / g to 20.5 J / g from the viewpoint of flexibility at room temperature and thermal conductivity of the cured body. It is preferable that The exothermic peak in differential scanning calorimetry (DSC) measurement reflects the amount of unreacted epoxy resin monomer and curing agent present in the epoxy resin composition.
　エポキシ樹脂組成物の示差走査熱量（ＤＳＣ）測定は、例えば、パーキンエルマー製の示差走査熱量測定装置を用いて行うことができる。測定で得られたデータの発熱ピークの面積を、測定に用いたサンプルの質量で割った値が１２．８Ｊ／ｇ～２０．５Ｊ／ｇであることが、常温での柔軟性及び硬化体の熱伝導性の観点から好ましい。この発熱ピーク面積は１２．８Ｊ／ｇ～２０．０Ｊ／ｇであることがより好ましく、１２．８Ｊ／ｇ～１９．２Ｊ／ｇであることがさらに好ましい。 The differential scanning calorimetry (DSC) measurement of the epoxy resin composition can be performed using, for example, a differential scanning calorimeter manufactured by PerkinElmer. The value obtained by dividing the exothermic peak area of the data obtained by the measurement by the mass of the sample used for the measurement is 12.8 J / g to 20.5 J / g. It is preferable from the viewpoint of thermal conductivity. The exothermic peak area is more preferably 12.8 J / g to 20.0 J / g, and further preferably 12.8 J / g to 19.2 J / g.
＜エポキシ樹脂組成物の製造方法＞
　本開示のエポキシ樹脂組成物の製造方法は、メソゲン骨格を有するエポキシ樹脂モノマーと、ノボラック樹脂を含む硬化剤と、無機フィラーと、を含有する組成物（例えば、樹脂ワニス）を熱処理し、メソゲン骨格を有するエポキシ樹脂モノマーのオリゴマー体を生成させてエポキシ樹脂組成物を得る工程を含む。なお、上記オリゴマー体は、メソゲン骨格を有するエポキシ樹脂モノマーとノボラック樹脂との反応物を含むものである。 <Method for producing epoxy resin composition>
The method for producing an epoxy resin composition of the present disclosure includes a heat treatment of a composition (for example, a resin varnish) containing an epoxy resin monomer having a mesogenic skeleton, a curing agent containing a novolac resin, and an inorganic filler, and the mesogenic skeleton. A step of producing an epoxy resin composition by producing an oligomer of an epoxy resin monomer having a cation. The oligomer body includes a reaction product of an epoxy resin monomer having a mesogenic skeleton and a novolac resin.
　熱処理前の組成物（以下、「未熱処理組成物」ともいう。）に含有されるメソゲン骨格を有するエポキシ樹脂モノマーは、本開示のエポキシ樹脂組成物に含有されるメソゲン骨格を有するエポキシ樹脂モノマーと同じものでよい。
　上記未熱処理組成物中におけるメソゲン骨格を有するエポキシ樹脂モノマーの含有率は特に制限されない。成形性及び硬化体の熱伝導性の観点から、メソゲン骨格を有するエポキシ樹脂モノマーの含有率は、上記未熱処理組成物の固形分中に５質量％～３５質量％であることが好ましく、５質量％～２５質量％であることがより好ましい。 The epoxy resin monomer having a mesogen skeleton contained in a composition before heat treatment (hereinafter also referred to as “unheat-treated composition”) is an epoxy resin monomer having a mesogen skeleton contained in the epoxy resin composition of the present disclosure. The same can be used.
The content rate of the epoxy resin monomer having a mesogen skeleton in the unheat-treated composition is not particularly limited. From the viewpoint of moldability and thermal conductivity of the cured body, the content of the epoxy resin monomer having a mesogenic skeleton is preferably 5% by mass to 35% by mass in the solid content of the unheat-treated composition. % To 25% by mass is more preferable.
　上記未熱処理組成物に含有されるノボラック樹脂を含む硬化剤は、本開示のエポキシ樹脂組成物に含有される硬化剤と同じでよい。
　上記未熱処理組成物中における硬化剤の含有率は特に制限されない。硬化体の熱伝導性の観点から、硬化剤の含有率は、上記未熱処理組成物の固形分中に１質量％～１５質量％であることが好ましく、１質量％～１０質量％であることがより好ましい。また、硬化剤におけるフェノール性水酸基の当量数とエポキシ樹脂モノマーにおけるエポキシ基の当量数との比（フェノール性水酸基の当量数／エポキシ基の当量数）が０．５～２となることが好ましく、０．８～１．２となることがより好ましい。 The curing agent containing the novolak resin contained in the unheat-treated composition may be the same as the curing agent contained in the epoxy resin composition of the present disclosure.
The content of the curing agent in the unheat-treated composition is not particularly limited. From the viewpoint of the thermal conductivity of the cured body, the content of the curing agent is preferably 1% by mass to 15% by mass in the solid content of the unheat-treated composition, and preferably 1% by mass to 10% by mass. Is more preferable. The ratio of the number of equivalents of phenolic hydroxyl groups in the curing agent and the number of equivalents of epoxy groups in the epoxy resin monomer (the number of equivalents of phenolic hydroxyl groups / the number of equivalents of epoxy groups) is preferably 0.5 to 2. More preferably, it is 0.8 to 1.2.
　上記硬化剤は、ノボラック樹脂を構成するフェノール樹脂モノマーを含んでいてもよい。上記硬化剤中におけるノボラック樹脂を構成するフェノール樹脂モノマーの含有比率（以下、「モノマー含有比率」ともいう。）としては特に制限はない。硬化体の熱伝導性及び耐熱性、並びにエポキシ樹脂組成物の成形性の観点から、モノマー含有比率は１０質量％～８０質量％であることが好ましく、１５質量％～６０質量％であることがより好ましく、２０質量％以上５０質量％以下であることがさらに好ましい。 The curing agent may contain a phenol resin monomer that constitutes a novolac resin. There is no restriction | limiting in particular as a content ratio (henceforth "monomer content ratio") of the phenol resin monomer which comprises the novolak resin in the said hardening | curing agent. From the viewpoint of thermal conductivity and heat resistance of the cured product and moldability of the epoxy resin composition, the monomer content is preferably 10% by mass to 80% by mass, and more preferably 15% by mass to 60% by mass. More preferably, it is 20 mass% or more and 50 mass% or less.
　モノマー含有比率が８０質量％以下であることで、硬化反応の際に架橋に寄与しないモノマーが少なくなり、架橋する高分子量体が多くなるため、より高密度な高次構造が形成され、熱伝導性が向上する傾向にある。また、モノマー含有比率が１０質量％以上であることで、成形の際にエポキシ樹脂が流動し易いため、無機フィラーとエポキシ樹脂との密着性がより向上し、より優れた熱伝導性及び耐熱性が達成できる傾向にある。 When the monomer content is 80% by mass or less, the amount of monomers that do not contribute to crosslinking during the curing reaction is reduced and the number of crosslinked high molecular weight substances is increased, so that a higher-order higher-order structure is formed and heat conduction is increased. Tend to improve. In addition, since the monomer content ratio is 10% by mass or more, the epoxy resin easily flows during molding, so the adhesion between the inorganic filler and the epoxy resin is further improved, and more excellent thermal conductivity and heat resistance. Tends to be achieved.
　上記未熱処理組成物に含有される無機フィラーは、本開示のエポキシ樹脂組成物に含有される無機フィラーと同じでよい。
　上記未熱処理組成物中における無機フィラーの含有率は特に制限されない。熱伝導性及び成形性の観点から、無機フィラーの含有率は、上記未熱処理組成物の全固形分の体積を１００体積％とした場合に、６０体積％～９０体積％であることが好ましく、７０体積％～９０体積％であることがより好ましい。無機フィラーの含有率が６０体積％以上であることで、硬化体についてより高い熱伝導性を達成することができる傾向にあり、一方、無機フィラーの含有率が９０体積％以下であることで、成形性に優れたエポキシ樹脂組成物を得ることができる傾向にある。 The inorganic filler contained in the unheat-treated composition may be the same as the inorganic filler contained in the epoxy resin composition of the present disclosure.
The content of the inorganic filler in the unheat-treated composition is not particularly limited. From the viewpoint of thermal conductivity and moldability, the content of the inorganic filler is preferably 60% by volume to 90% by volume when the volume of the total solid content of the unheat-treated composition is 100% by volume, More preferably, it is 70 to 90% by volume. When the content of the inorganic filler is 60% by volume or more, it tends to be able to achieve higher thermal conductivity for the cured body, while the content of the inorganic filler is 90% by volume or less. There exists a tendency which can obtain the epoxy resin composition excellent in the moldability.
　上記未熱処理組成物は、硬化促進剤、シランカップリング剤、分散剤等の他の成分をさらに含有していてもよい。
　また、上記未熱処理組成物は、有機溶剤の少なくとも１種をさらに含有することが好ましい。有機溶剤を含有することで種々の成形プロセスに適合させることが容易となる。有機溶剤としては通常用いられる有機溶剤から適宜選択することができる。具体的には、アルコール溶剤、エーテル溶剤、ケトン溶剤、アミド溶剤、芳香族炭化水素溶剤、エステル溶剤、ニトリル溶剤、スルホキシド溶剤等を挙げることができる。有機溶剤として具体的には、メチルイソブチルケトン、シクロヘキサノン、メチルエチルケトン等のケトン溶剤；ジメチルアセトアミド、ジメチルホルムアミド、Ｎ－メチル－２－ピロリドン等のアミド溶剤；γ－ブチロラクトン等のエステル溶剤；ジメチルスルホキシド、スルホラン等のスルホキシド溶剤；などを用いることができる。これらは１種単独で使用してもよく、２種以上を併用してもよい。 The unheat-treated composition may further contain other components such as a curing accelerator, a silane coupling agent, and a dispersant.
The unheated composition preferably further contains at least one organic solvent. By containing an organic solvent, it becomes easy to adapt to various molding processes. The organic solvent can be appropriately selected from commonly used organic solvents. Specific examples include alcohol solvents, ether solvents, ketone solvents, amide solvents, aromatic hydrocarbon solvents, ester solvents, nitrile solvents, sulfoxide solvents, and the like. Specific examples of organic solvents include ketone solvents such as methyl isobutyl ketone, cyclohexanone, and methyl ethyl ketone; amide solvents such as dimethylacetamide, dimethylformamide, and N-methyl-2-pyrrolidone; ester solvents such as γ-butyrolactone; dimethyl sulfoxide, sulfolane And the like can be used. These may be used alone or in combination of two or more.
　上記未熱処理組成物を熱処理する方法は特に限定されないが、８０℃～１８０℃で１分間～３０分間加熱する方法を挙げることができる。この熱処理は、１種類の温度条件による１段階処理であっても、複数種類の温度条件による多段階処理であってもよい。 The method for heat-treating the unheated composition is not particularly limited, and examples thereof include a method of heating at 80 to 180 ° C. for 1 to 30 minutes. This heat treatment may be a one-step process based on one kind of temperature condition or a multi-stage process based on a plurality of kinds of temperature conditions.
＜エポキシ樹脂組成物の半硬化体＞
　エポキシ樹脂組成物の半硬化体は、本開示のエポキシ樹脂組成物を半硬化処理してなるものである。 <Semi-cured product of epoxy resin composition>
The semi-cured product of the epoxy resin composition is obtained by semi-curing the epoxy resin composition of the present disclosure.
　ここで、エポキシ樹脂組成物の半硬化体とは、粘度が常温では１０４Ｐａ・ｓ～１０５Ｐａ・ｓであるのに対し、１００℃では１０２Ｐａ・ｓ～１０３Ｐａ・ｓに低下する特徴を有するものである。なお、上記粘度は動的粘弾性測定（ＤＭＡ）（例えば、ＴＡインスツルメンツ社製ＡＲＥＳ－２ＫＳＴＤ）によって測定される。測定条件は、周波数１Ｈｚ、荷重４０ｇ、昇温速度３℃／分であり、せん断試験により行う。 Here, the semi-cured product of the epoxy resin composition has a viscosity of 10 4 Pa · s to 10 5 Pa · s at room temperature, but is 10 2 Pa · s to 10 3 Pa · s at 100 ° C. It has a characteristic of decreasing. The viscosity is measured by dynamic viscoelasticity measurement (DMA) (for example, ARES-2KSTD manufactured by TA Instruments). The measurement conditions are a frequency of 1 Hz, a load of 40 g, a heating rate of 3 ° C./min, and a shear test is performed.
　半硬化処理の方法は特に限定されないが、１００℃～２００℃で１分間～３０分間加熱する方法を挙げることができる。 The method of the semi-curing treatment is not particularly limited, and examples thereof include a method of heating at 100 ° C. to 200 ° C. for 1 minute to 30 minutes.
＜エポキシ樹脂組成物の硬化体＞
　エポキシ樹脂組成物の硬化体は、本開示のエポキシ樹脂組成物を硬化処理してなるものである。この硬化体は熱伝導性に優れるが、これは例えば、エポキシ樹脂組成物に含有されるメソゲン骨格を有するエポキシ樹脂モノマーが、無機フィラーを中心に高次構造を形成しているためと考えられる。 <Hardened body of epoxy resin composition>
The cured product of the epoxy resin composition is obtained by curing the epoxy resin composition of the present disclosure. This cured product is excellent in thermal conductivity. This is considered to be because, for example, an epoxy resin monomer having a mesogen skeleton contained in the epoxy resin composition forms a higher order structure centering on an inorganic filler.
　硬化処理の方法は、エポキシ樹脂組成物の構成、硬化体の目的等に応じて適宜選択することができ、加熱及び加圧処理であることが好ましい。
　例えば、本開示のエポキシ樹脂組成物を１ＭＰａ～２０ＭＰａに加圧しながら、１００℃～２５０℃で３０分間～８時間、好ましくは１ＭＰａ～１５ＭＰａに加圧しながら、１３０℃～２３０℃で３０分間～６時間加熱することで硬化体が得られる。 The method of the curing treatment can be appropriately selected according to the configuration of the epoxy resin composition, the purpose of the cured body, etc., and is preferably heating and pressure treatment.
For example, the epoxy resin composition of the present disclosure is pressurized at 1 to 20 MPa at 100 to 250 ° C. for 30 minutes to 8 hours, preferably 1 to 15 MPa at 130 to 230 ° C. for 30 minutes to 6 minutes. A cured product is obtained by heating for a period of time.
＜樹脂シート＞
　本開示の樹脂シートは、本開示のエポキシ樹脂組成物のシート状成形体であり、必要に応じて離型フィルムをさらに含んで構成される。本開示の樹脂シートは常温で柔軟性を有し、かつ硬化体は熱伝導性に優れる。 <Resin sheet>
The resin sheet of the present disclosure is a sheet-like molded body of the epoxy resin composition of the present disclosure, and further includes a release film as necessary. The resin sheet of the present disclosure has flexibility at room temperature, and the cured body has excellent thermal conductivity.
　本開示の樹脂シートの密度は特に制限されず、例えば、３．０ｇ／ｃｍ３～３．５ｇ／ｃｍ３とすることができる。樹脂シートの柔軟性、及び硬化体の熱伝導性の両立を考慮すると、３．１ｇ／ｃｍ３～３．４ｇ／ｃｍ３が好ましく、３．１ｇ／ｃｍ３～３．３ｇ／ｃｍ３がより好ましい。樹脂シートの密度は、例えば、エポキシ樹脂組成物における無機フィラーの含有率を適宜選択することで調整することができる。 The density of the resin sheet of the present disclosure is not particularly limited, and can be, for example, 3.0 g / cm 3 to 3.5 g / cm 3 . In consideration of both the flexibility of the resin sheet and the thermal conductivity of the cured body, 3.1 g / cm 3 to 3.4 g / cm 3 is preferable, and 3.1 g / cm 3 to 3.3 g / cm 3 is more preferable. preferable. The density of the resin sheet can be adjusted, for example, by appropriately selecting the content of the inorganic filler in the epoxy resin composition.
　本開示の樹脂シートの厚みは特に制限されず、目的に応じて適宜選択することができる。例えば、５０μｍ～５００μｍとすることができ、熱伝導性及び電気絶縁性の観点から、１００μｍ～３００μｍであることが好ましい。 The thickness of the resin sheet of the present disclosure is not particularly limited and can be appropriately selected depending on the purpose. For example, the thickness may be 50 μm to 500 μm, and is preferably 100 μm to 300 μm from the viewpoint of thermal conductivity and electrical insulation.
　本開示の樹脂シートは、有機溶剤を含有する上記未熱処理組成物を、ＰＥＴ（ポリエチレンテレフタレート）フィルム等の離型フィルム上に塗布して塗布層を形成し、熱処理することで製造することができる。 The resin sheet of the present disclosure can be produced by applying the unheated composition containing an organic solvent on a release film such as a PET (polyethylene terephthalate) film to form a coating layer and heat-treating it. .
　上記未熱処理組成物の塗布は、公知の方法により実施することができる。具体的には、コンマコート、ダイコート、リップコート、グラビアコート等の方法が挙げられる。所定の厚みに塗布層を形成するための塗布方法としては、ギャップ間に被塗工物を通過させるコンマコート法、ノズルから流量を調節した上記未熱処理組成物を塗布するダイコート法等が挙げられる。例えば、熱処理前の塗布層の厚みが５０μｍ～５００μｍである場合は、コンマコート法を用いることが好ましい。 The application of the unheat-treated composition can be performed by a known method. Specific examples include methods such as comma coating, die coating, lip coating, and gravure coating. Examples of a coating method for forming a coating layer with a predetermined thickness include a comma coating method in which an object to be coated is passed between gaps, and a die coating method in which the unheated composition with a flow rate adjusted from a nozzle is coated. . For example, when the thickness of the coating layer before heat treatment is 50 μm to 500 μm, it is preferable to use a comma coating method.
　本開示の樹脂シートにおける熱処理前の塗布層は、エポキシ樹脂モノマーによる反応がほとんど進行しておらず、エポキシ樹脂モノマーがほぼ結晶状態で存在している。このため、熱処理前のシートは可とう性は有するものの、柔軟性には乏しく、支持体である離型フィルムを除去した状態では自立性に乏しく、取り扱い難い。
　また、上記塗布層が半硬化状態（Ｂステージ状態）になるまで熱処理した半硬化シートは、常温ではエポキシ樹脂モノマーが再結晶化するため、柔軟性に乏しくなる。 In the coating layer before heat treatment in the resin sheet of the present disclosure, the reaction with the epoxy resin monomer hardly progresses, and the epoxy resin monomer exists in a substantially crystalline state. For this reason, although the sheet before heat treatment has flexibility, it is poor in flexibility, and in the state where the release film as a support is removed, it is poor in self-supporting and difficult to handle.
Moreover, since the epoxy resin monomer is recrystallized at room temperature, the semi-cured sheet that has been heat-treated until the coating layer is in a semi-cured state (B-stage state) is poor in flexibility.
　一方、本開示の樹脂シートは、本開示のエポキシ樹脂組成物から構成されることで、常温でも柔軟性を有し、かつ樹脂シートとしての可とう性及び可使時間に優れる。その理由は明確ではないが、本開示の樹脂シートでは半硬化シートよりも緩いネットワーク構造が形成されているためと推測される。
　熱処理の方法は、本開示のエポキシ樹脂組成物として必要な特性を満たしていれば特に制限されず、適宜選択することができる。例えば、８０℃～１８０℃で１分間～３０分間加熱する方法が挙げられる。 On the other hand, the resin sheet of the present disclosure is composed of the epoxy resin composition of the present disclosure, so that it has flexibility even at room temperature and is excellent in flexibility and usable time as a resin sheet. Although the reason is not clear, it is assumed that the resin sheet of the present disclosure has a looser network structure than the semi-cured sheet.
The heat treatment method is not particularly limited as long as it satisfies the characteristics required for the epoxy resin composition of the present disclosure, and can be appropriately selected. For example, a method of heating at 80 to 180 ° C. for 1 to 30 minutes can be mentioned.
＜プリプレグ＞
　本開示のプリプレグは、繊維基材と、本開示のエポキシ樹脂組成物を含む樹脂マトリックスと、を有して構成される。かかる構成であることで、熱伝導性に優れたプリプレグとなる。また、無機フィラーを含有する上記未熱処理組成物はチキソ性が高いため、後述の塗工工程又は含浸工程における無機フィラーの沈降を抑制することができる。したがって、プリプレグの厚み方向での無機フィラーの濃淡分布の発生を抑えることができ、結果として、熱伝導性に優れるプリプレグが得られる。 <Prepreg>
The prepreg of the present disclosure includes a fiber base material and a resin matrix including the epoxy resin composition of the present disclosure. With such a configuration, a prepreg having excellent thermal conductivity is obtained. Moreover, since the said non-heat-treatment composition containing an inorganic filler has high thixotropy, sedimentation of the inorganic filler in the below-mentioned coating process or impregnation process can be suppressed. Therefore, it is possible to suppress the occurrence of the density distribution of the inorganic filler in the thickness direction of the prepreg, and as a result, a prepreg excellent in thermal conductivity is obtained.
　プリプレグを構成する繊維基材としては、金属箔貼り積層板又は多層配線板を製造する際に通常用いられるものであれば特に制限されず、通常用いられる織布、不織布等の繊維基材から適宜選択される。 The fiber base material constituting the prepreg is not particularly limited as long as it is usually used when producing a metal foil-clad laminate or a multilayer wiring board, and is appropriately selected from fiber base materials such as woven fabrics and nonwoven fabrics that are usually used. Selected.
　上記繊維基材の目開きは特に制限されない。熱伝導性及び電気絶縁性の観点から、目開きは無機フィラーの平均粒子径（Ｄ５０）の５倍以上であることが好ましい。また、無機フィラーの粒度分布曲線が複数のピークを有する場合、粒子径が最大となるピークに対応する粒子径の５倍以上の目開きであることがより好ましい。 The opening of the fiber base material is not particularly limited. From the viewpoint of thermal conductivity and electrical insulation, the mesh opening is preferably 5 times or more the average particle diameter (D50) of the inorganic filler. In addition, when the particle size distribution curve of the inorganic filler has a plurality of peaks, it is more preferable that the opening be 5 times or more the particle diameter corresponding to the peak having the largest particle diameter.
　上記繊維基材の材質は特に制限されない。具体的には、ガラス、アルミナ、ボロン、シリカアルミナガラス、シリカガラス、チラノ（tyranno）、炭化ケイ素、窒化ケイ素、ジルコニア、カーボン等の無機繊維、アラミド、ポリエーテルエーテルケトン、ポリエーテルイミド、ポリエーテルスルフォン、セルロース等の有機繊維、これらの混抄系などを挙げることができる。 The material of the fiber base is not particularly limited. Specifically, inorganic fibers such as glass, alumina, boron, silica alumina glass, silica glass, tyranno, silicon carbide, silicon nitride, zirconia, carbon, aramid, polyetheretherketone, polyetherimide, polyether Examples thereof include organic fibers such as sulfone and cellulose, and mixed papers thereof.
　中でも繊維基材としてはガラス繊維の織布が好ましく用いられる。これにより例えば、プリプレグを用いて配線板を構成する場合、屈曲性があり任意に折り曲げ可能な配線板を得ることができる。さらに、製造プロセスでの温度変化、吸湿等に伴う配線板の寸法変化を小さくすることも可能となる。 Among them, a glass fiber woven fabric is preferably used as the fiber base material. Thereby, for example, when a wiring board is configured using prepreg, a wiring board that is flexible and can be arbitrarily bent can be obtained. Furthermore, it becomes possible to reduce the dimensional change of the wiring board accompanying the temperature change, moisture absorption, etc. in the manufacturing process.
　上記繊維基材の厚さは特に限定されない。より良好な可とう性を付与する観点から、３０μｍ以下であることが好ましく、含浸性の観点から１５μｍ以下であることがより好ましい。繊維基材の厚みの下限は特に制限されないが、通常は５μｍ程度である。 The thickness of the fiber base material is not particularly limited. From the viewpoint of imparting better flexibility, it is preferably 30 μm or less, and more preferably 15 μm or less from the viewpoint of impregnation. Although the minimum of the thickness of a fiber base material is not restrict | limited in particular, Usually, it is about 5 micrometers.
　本開示のプリプレグにおけるエポキシ樹脂組成物の質量割合は、プリプレグの総質量中に５０質量％～９９．９質量％であることが好ましい。 The mass ratio of the epoxy resin composition in the prepreg of the present disclosure is preferably 50% by mass to 99.9% by mass in the total mass of the prepreg.
　本開示のプリプレグは、有機溶剤を含有する上記未熱処理組成物を繊維基材に塗工又は含浸し、熱処理することで製造することができる。熱処理によって上記樹脂ワニスの硬化反応が部分的に進行し、エポキシ樹脂組成物を含む樹脂マトリックスが形成される。
　熱処理の方法は、本開示のエポキシ樹脂組成物として必要な特性を満たしていれば特に制限されず、適宜選択することができる。例えば、８０℃～１８０℃で１分間～３０分間加熱する方法が挙げられる。 The prepreg of the present disclosure can be manufactured by coating or impregnating a fiber base material with the unheated composition containing an organic solvent, followed by heat treatment. By the heat treatment, the curing reaction of the resin varnish partially proceeds to form a resin matrix containing the epoxy resin composition.
The heat treatment method is not particularly limited as long as it satisfies the characteristics required for the epoxy resin composition of the present disclosure, and can be appropriately selected. For example, a method of heating at 80 to 180 ° C. for 1 to 30 minutes can be mentioned.
　また、上記未熱処理組成物を繊維基材に塗工又は含浸する方法に特に制限はない。例えば、塗工機により塗布する方法を挙げることができる。詳細には、繊維基材を上記未熱処理組成物にくぐらせて引き上げる縦型塗工法、支持フィルム上に上記未熱処理組成物を塗工してから繊維基材を押し付け、含浸させる横型塗工法等を挙げることができる。繊維基材内での無機フィラーの偏在を抑える観点からは横型塗工法が好適である。 Also, there is no particular limitation on the method for coating or impregnating the fiber base with the unheated composition. For example, the method of apply | coating with a coating machine can be mentioned. Specifically, a vertical coating method in which the fiber base material is pulled through the unheated composition, a horizontal coating method in which the fiber base material is pressed and impregnated after the unheated composition is coated on a support film, etc. Can be mentioned. From the viewpoint of suppressing the uneven distribution of the inorganic filler in the fiber base material, the horizontal coating method is suitable.
　本開示のプリプレグは、被着材上に積層又は貼付する前に、プレス、ロールラミネータ等による熱間加圧処理により、あらかじめ表面を平滑化してから使用してもよい。熱間加熱処理の方法としては、熱真空プレス、熱ロールラミネート等が挙げられる。具体的には、例えば、減圧下（例えば、１ｋＰａ）、１００℃～２００℃で１分間～５分間、１ＭＰａ～２０ＭＰａのプレス圧で加熱及び加圧処理することで、プリプレグの表面を平滑化することができる。 The prepreg of the present disclosure may be used after the surface is smoothed in advance by hot pressing with a press, a roll laminator or the like before being laminated or stuck on the adherend. Examples of the hot heat treatment method include a hot vacuum press and a hot roll laminate. Specifically, for example, the surface of the prepreg is smoothed by heating and pressurizing under reduced pressure (eg, 1 kPa) at 100 to 200 ° C. for 1 minute to 5 minutes with a press pressure of 1 MPa to 20 MPa. be able to.
＜積層板＞
　本開示の積層板は、被着材と、上記被着材上に配置された半硬化層又は硬化層と、を有する。上記半硬化層は、本開示のエポキシ樹脂組成物、本開示の樹脂シート、及び本開示のプリプレグからなる群より選択される少なくとも１つの半硬化体であり、上記硬化層は、上記半硬化層が硬化したものである。半硬化層又は硬化層を有することで熱伝導性に優れた積層板となる。 <Laminated plate>
The laminate of the present disclosure includes an adherend and a semi-cured layer or a cured layer disposed on the adherend. The semi-cured layer is at least one semi-cured body selected from the group consisting of the epoxy resin composition of the present disclosure, the resin sheet of the present disclosure, and the prepreg of the present disclosure, and the cured layer is the semi-cured layer. Is cured. By having a semi-hardened layer or a hardened layer, it becomes a laminated board excellent in thermal conductivity.
　上記被着材としては、金属箔、金属板等を挙げることができる。被着材は、半硬化層又は硬化層の片面のみに付設しても、両面に付設してもよい。 Examples of the adherend include metal foil and metal plate. The adherend may be attached to only one side of the semi-cured layer or the cured layer, or may be attached to both sides.
　上記金属箔としては特に制限されず、通常用いられる金属箔から適宜選択することができる。具体的には、金箔、銅箔、アルミニウム箔等を挙げることができ、一般的には銅箔が用いられる。金属箔の厚みとしては、１μｍ～２００μｍであれば特に制限されず、使用目的に応じて好適な厚みを選択することができる。 The metal foil is not particularly limited and can be appropriately selected from commonly used metal foils. Specifically, gold foil, copper foil, aluminum foil, etc. can be mentioned, and copper foil is generally used. The thickness of the metal foil is not particularly limited as long as it is 1 μm to 200 μm, and a suitable thickness can be selected according to the purpose of use.
　また、上記金属箔として、ニッケル、ニッケル－リン、ニッケル－スズ合金、ニッケル－鉄合金、鉛、鉛－スズ合金等を中間層とし、この両表面に０．５μｍ～１５μｍの銅層と１０μｍ～１５０μｍの銅層とを設けた３層構造の複合箔、又はアルミニウムと銅箔とを複合した２層構造複合箔を用いることもできる。 Further, as the metal foil, nickel, nickel-phosphorus, nickel-tin alloy, nickel-iron alloy, lead, lead-tin alloy, etc. are used as intermediate layers, and a copper layer of 0.5 μm to 15 μm and 10 μm to A composite foil having a three-layer structure provided with a 150 μm copper layer, or a two-layer structure composite foil in which aluminum and a copper foil are combined can also be used.
　上記金属板としては特に制限はないが、熱伝導性が高く、熱容量が大きい金属材料からなることが好ましい。具体的には、銅、アルミニウム、鉄、リードフレームに使われる合金等が例示できる。 The metal plate is not particularly limited, but is preferably made of a metal material having high thermal conductivity and a large heat capacity. Specific examples include copper, aluminum, iron, alloys used for lead frames, and the like.
　上記金属板の板厚は用途に応じて適宜選択することができる。また、上記金属板は、軽量化又は加工性を優先する場合はアルミニウム、放熱性を優先する場合は銅というように、目的を応じて材質を選定することができる。 The thickness of the metal plate can be appropriately selected according to the application. The metal plate can be selected according to the purpose, such as aluminum when weight reduction or workability is prioritized or copper when heat dissipation is prioritized.
　本開示の積層板においては、半硬化層として、本開示のエポキシ樹脂組成物、本開示の樹脂シート、又は本開示のプリプレグのいずれか１つに由来する１層を有する形態であってもよく、２層以上を積層して有する形態であってもよい。２層以上の半硬化層を有する場合、エポキシ樹脂組成物の半硬化体を含む層を２層以上有する形態、樹脂シートの半硬化体を２枚以上有する形態、及びプリプレグの半硬化体を２枚以上有する形態のいずれであってもよい。さらには、エポキシ樹脂組成物の半硬化体を含む層、樹脂シートの半硬化体、及びプリプレグの半硬化体のいずれか２つ以上を組み合わせて有してもよい。積層板が半硬化層の代わりに硬化層を有する場合も同様である。 In the laminate of the present disclosure, the semi-cured layer may have one layer derived from any one of the epoxy resin composition of the present disclosure, the resin sheet of the present disclosure, or the prepreg of the present disclosure. The form which has two or more layers laminated | stacked may be sufficient. In the case of having two or more semi-cured layers, the form having two or more layers containing the semi-cured body of the epoxy resin composition, the form having two or more semi-cured bodies of the resin sheet, and the semi-cured body of the prepreg 2 Any form having at least one sheet may be used. Furthermore, you may have in combination any 2 or more of the layer containing the semi-hardened body of an epoxy resin composition, the semi-hardened body of a resin sheet, and the semi-hardened body of a prepreg. The same applies when the laminate has a cured layer instead of a semi-cured layer.
　本開示の積層板は、例えば、被着材上に本開示のエポキシ樹脂組成物を付与して塗布層を形成し、これを加熱及び加圧処理してエポキシ樹脂組成物を半硬化又は硬化させるとともに、被着材に密着させることで得られる。あるいは、被着材に本開示の樹脂シート又は本開示のプリプレグを積層したものを準備し、これを加熱及び加圧して樹脂シート又はプリプレグを半硬化又は硬化させるとともに、被着材に密着させることで得られる。 The laminated board of this indication provides the epoxy resin composition of this indication on a to-be-adhered material, for example, forms an application layer, heats and pressurizes this, and makes an epoxy resin composition semi-harden or harden | cure. At the same time, it is obtained by bringing it into close contact with the adherend. Alternatively, a laminate of the resin sheet of the present disclosure or the prepreg of the present disclosure is prepared on an adherend, and the resin sheet or the prepreg is semi-cured or cured by heating and pressurizing the adherend, and is adhered to the adherend. It is obtained with.
　半硬化処理又は硬化処理の方法は特に制限されない。例えば、加熱及び加圧処理であることが好ましい。加熱及び加圧処理における加熱温度は特に限定されない。通常１００℃～２５０℃の範囲であり、好ましくは１３０℃～２３０℃の範囲である。また、加熱及び加圧処理における加圧条件は特に限定されない。通常１ＭＰａ～２０ＭＰａの範囲であり、好ましくは１ＭＰａ～１５ＭＰａの範囲である。また、加熱及び加圧処理には、真空プレスが好適に用いられる。 The method of semi-curing treatment or curing treatment is not particularly limited. For example, heat treatment and pressure treatment are preferable. The heating temperature in the heating and pressure treatment is not particularly limited. Usually, it is in the range of 100 ° C to 250 ° C, preferably in the range of 130 ° C to 230 ° C. Moreover, the pressurization conditions in a heating and pressurizing process are not specifically limited. Usually, it is in the range of 1 MPa to 20 MPa, preferably in the range of 1 MPa to 15 MPa. Moreover, a vacuum press is used suitably for a heating and pressurizing process.
　本開示の積層板の厚さは５００μｍ以下であることが好ましく、１００μｍ～３００μｍであることがより好ましい。厚さが５００μｍ以下であると可とう性に優れ、曲げ加工時にクラックが発生するのが抑えられる傾向にあり、厚さが３００μｍ以下の場合はその傾向がより見られる。また、厚さが１００μｍ以上の場合には作業性に優れる傾向にある。 The thickness of the laminate of the present disclosure is preferably 500 μm or less, and more preferably 100 μm to 300 μm. When the thickness is 500 μm or less, the flexibility is excellent, and cracks tend to be suppressed during bending, and when the thickness is 300 μm or less, the tendency is further observed. Further, when the thickness is 100 μm or more, the workability tends to be excellent.
＜硬化体＞
　本開示の硬化体は、本開示のエポキシ樹脂組成物、本開示の樹脂シート、又は本開示のプリプレグを硬化させたものである。この硬化体は熱伝導性に優れるが、これは例えば、メソゲン骨格を有するエポキシ樹脂モノマー及びそのオリゴマー体が、無機フィラーを中心に高次構造を形成しているためと考えられる。 <Hardened body>
The cured body of the present disclosure is obtained by curing the epoxy resin composition of the present disclosure, the resin sheet of the present disclosure, or the prepreg of the present disclosure. This cured product is excellent in thermal conductivity. This is considered to be because, for example, an epoxy resin monomer having a mesogenic skeleton and its oligomer form a higher order structure centering on an inorganic filler.
　硬化処理の方法は特に制限されない。例えば、加熱及び加圧処理であることが好ましい。加熱及び加圧処理における加熱温度は特に限定されない。通常１００℃～２５０℃の範囲であり、好ましくは１３０℃～２３０℃の範囲である。また、加熱及び加圧処理における加圧条件は特に限定されない。通常１ＭＰａ～２０ＭＰａの範囲であり、好ましくは１ＭＰａ～１５ＭＰａの範囲である。また、加熱及び加圧処理には、真空プレスが好適に用いられる。 The method for the curing treatment is not particularly limited. For example, heat treatment and pressure treatment are preferable. The heating temperature in the heating and pressure treatment is not particularly limited. Usually, it is in the range of 100 ° C to 250 ° C, preferably in the range of 130 ° C to 230 ° C. Moreover, the pressurization conditions in a heating and pressurizing process are not specifically limited. Usually, it is in the range of 1 MPa to 20 MPa, preferably in the range of 1 MPa to 15 MPa. Moreover, a vacuum press is used suitably for a heating and pressurizing process.
　以下、本発明を実施例により具体的に説明するが、本発明はこれらの実施例に限定されるものではない。なお、特に断りのない限り、「部」及び「％」は質量基準である。 Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples. Unless otherwise specified, “part” and “%” are based on mass.
　以下に、実施例及び比較例で用いた材料及びその略号を示す。
（エポキシ樹脂モノマー）
・樹脂モノマーＡ［特許第５４７１９７５号公報参照、エポキシ当量：２２４ｇ／ｅｑ］ The materials used in Examples and Comparative Examples and their abbreviations are shown below.
(Epoxy resin monomer)
Resin monomer A [see Japanese Patent No. 5471975, epoxy equivalent: 224 g / eq]
Figure JPOXMLDOC01-appb-C000028
Figure JPOXMLDOC01-appb-C000028
・樹脂モノマーＢ［特許第４６１９７７０号公報参照、エポキシ当量：２０１ｇ／ｅｑ］ Resin monomer B [refer to Japanese Patent No. 4619770, epoxy equivalent: 201 g / eq]
Figure JPOXMLDOC01-appb-C000029
Figure JPOXMLDOC01-appb-C000029
・樹脂モノマーＣ［ＹＬ６１２１Ｈ（三菱化学株式会社製）、下記式中Ｒ＝ＨとＲ＝ＣＨ３とが約１：１の混合物、エポキシ当量：約１７５ｇ／ｅｑ］ Resin Monomer C [YL6121H (manufactured by Mitsubishi Chemical Corporation), following formula R = H and R = CH 3 Togayaku 1: 1 mixture of epoxy equivalent: about 175 g / eq]
Figure JPOXMLDOC01-appb-C000030
Figure JPOXMLDOC01-appb-C000030
・樹脂モノマーＤ［ビスフェノールＡ型エポキシ樹脂モノマー、８２８（三菱化学株式会社製）、エポキシ当量：約１９０ｇ／ｅｑ］ Resin monomer D [bisphenol A type epoxy resin monomer, 828 (Mitsubishi Chemical Corporation), epoxy equivalent: about 190 g / eq]
（無機フィラー）
・ＡＡ－１８［α－アルミナ（住友化学株式会社製）、平均粒子径１８μｍ］
・ＡＡ－３［α－アルミナ（住友化学株式会社製）、平均粒子径３μｍ］
・ＡＡ－０４［α－アルミナ（住友化学株式会社製）、平均粒子径０．４μｍ］
・ＨＰ－４０［窒化ホウ素（水島合金鉄株式会社製）、平均粒子径１８μｍ］ (Inorganic filler)
AA-18 [α-alumina (manufactured by Sumitomo Chemical Co., Ltd.), average particle size 18 μm]
AA-3 [α-alumina (manufactured by Sumitomo Chemical Co., Ltd., average particle size: 3 μm)
AA-04 [α-Alumina (Sumitomo Chemical Co., Ltd.), average particle size 0.4 μm]
・ HP-40 [Boron nitride (manufactured by Mizushima Alloy Iron Co., Ltd.), average particle size 18 μm]
（硬化剤）
・ＣＲＮ［カテコールレゾルシノールノボラック（仕込み比：５／９５）樹脂、日立化成株式会社製、シクロヘキサノン５０％含有］
＜ＣＲＮの合成方法＞
　撹拌機、冷却器、及び温度計を備えた３Ｌのセパラブルフラスコに、レゾルシノール６２７ｇ、カテコール３３ｇ、３７％ホルムアルデヒド３１６．２ｇ、シュウ酸１５ｇ、及び水３００ｇを入れ、オイルバスで加温しながら１００℃に昇温した。１０４℃前後で還流し、還流温度で４時間反応を続けた。その後、水を留去しながらフラスコ内の温度を１７０℃に昇温した。１７０℃を保持しながら８時間反応を続けた。反応後、減圧下２０分間濃縮を行い、系内の水等を除去し、目的であるノボラック樹脂ＣＲＮを得た。
　また、得られたＣＲＮについて、電界脱離イオン化質量分析法（ＦＤ－ＭＳ）により構造を確認したところ、上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）のうちの少なくとも１つで表される構造の存在が確認できた。 (Curing agent)
CRN [catechol resorcinol novolak (preparation ratio: 5/95) resin, manufactured by Hitachi Chemical Co., Ltd., containing 50% cyclohexanone]
<Synthesis method of CRN>
A 3 L separable flask equipped with a stirrer, a cooler, and a thermometer was charged with 627 g of resorcinol, 33 g of catechol, 316.2 g of 37% formaldehyde, 15 g of oxalic acid, and 300 g of water, and heated while heating in an oil bath. The temperature was raised to ° C. The mixture was refluxed at around 104 ° C., and the reaction was continued at the reflux temperature for 4 hours. Thereafter, the temperature in the flask was raised to 170 ° C. while distilling off water. The reaction was continued for 8 hours while maintaining 170 ° C. After the reaction, concentration was performed under reduced pressure for 20 minutes to remove water and the like in the system to obtain the desired novolak resin CRN.
Further, when the structure of the obtained CRN was confirmed by field desorption ionization mass spectrometry (FD-MS), it was represented by at least one of the above general formulas (III-1) to (III-4). The existence of the structure was confirmed.
　得られたＣＲＮについて、数平均分子量（Ｍｎ）、重量平均分子量（Ｍｗ）の測定を次のようにして行った。
　Ｍｎ及びＭｗの測定は、株式会社日立製作所製高速液体クロマトグラフィＬ６０００、及び株式会社島津製作所製データ解析装置Ｃ－Ｒ４Ａを用いて行った。分析用ＧＰＣカラムは、東ソー株式会社製Ｇ２０００ＨＸＬ及びＧ３０００ＨＸＬを使用した。試料濃度は０．２％、移動相にはテトラヒドロフランを用い、流速１．０ｍＬ／分で測定を行った。ポリスチレン標準サンプルを用いて検量線を作成し、それを用いてポリスチレン換算値でＭｎ及びＭｗを計算した。 About the obtained CRN, the number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured as follows.
Mn and Mw were measured using a high performance liquid chromatography L6000 manufactured by Hitachi, Ltd. and a data analyzer C-R4A manufactured by Shimadzu Corporation. G2000HXL and G3000HXL manufactured by Tosoh Corporation were used as analytical GPC columns. The sample concentration was 0.2%, tetrahydrofuran was used as the mobile phase, and the measurement was performed at a flow rate of 1.0 mL / min. A calibration curve was prepared using a polystyrene standard sample, and Mn and Mw were calculated using polystyrene conversion values.
　また、得られたＣＲＮについて、水酸基当量の測定を次のようにして行った。
　水酸基当量は、塩化アセチル－水酸化カリウム滴定法により測定した。なお、滴定終点の判断は溶液の色が暗色のため、指示薬による呈色法ではなく、電位差滴定によって行った。具体的には、測定樹脂の水酸基をピリジン溶液中塩化アセチル化した後、その過剰の試薬を水で分解し、生成した酢酸を水酸化カリウム／メタノール溶液で滴定したものである。 Moreover, about the obtained CRN, the measurement of the hydroxyl equivalent was performed as follows.
The hydroxyl equivalent was measured by acetyl chloride-potassium hydroxide titration method. The determination of the titration end point was performed by potentiometric titration instead of the coloring method using an indicator because the solution color was dark. Specifically, the hydroxyl group of the measurement resin is acetylated in a pyridine solution, the excess reagent is decomposed with water, and the resulting acetic acid is titrated with a potassium hydroxide / methanol solution.
　得られたＣＲＮは、上記一般式（ＩＩＩ－１）～（ＩＩＩ－４）のうちの少なくとも１つで表される構造を有する化合物を含む混合物であり、Ａｒ３１～Ａｒ３４が、上記一般式（ＩＩＩ－ａ）においてＲ３１＝ＯＨであり、Ｒ３２＝Ｒ３３＝Ｈである１，２－ジヒドロキシベンゼン（カテコール）に由来する基、及び１，３－ジヒドロキシベンゼン（レゾルシノール）に由来する基であり、低分子希釈剤としてモノマー成分（レゾルシノール）を３５％含むノボラック樹脂（Ｍｎ：４２２、Ｍｗ：５６４、水酸基当量：６５ｇ／ｅｑ）であった。 The obtained CRN is a mixture containing a compound having a structure represented by at least one of the above general formulas (III-1) to (III-4), wherein Ar 31 to Ar 34 are the above general formulas A group derived from 1,2-dihydroxybenzene (catechol) and a group derived from 1,3-dihydroxybenzene (resorcinol) wherein R 31 = OH and R 32 = R 33 = H in (III-a) It was a novolak resin (Mn: 422, Mw: 564, hydroxyl equivalent: 65 g / eq) containing 35% of a monomer component (resorcinol) as a low molecular diluent.
（添加剤）
・ＴＰＰ：トリフェニルホスフィン［硬化促進剤］
・ＫＢＭ－５７３：３－フェニルアミノプロピルトリメトキシシラン［シランカップリング剤、信越化学工業株式会社製］ (Additive)
・ TPP: Triphenylphosphine [curing accelerator]
KBM-573: 3-phenylaminopropyltrimethoxysilane [Silane coupling agent, manufactured by Shin-Etsu Chemical Co., Ltd.]
（溶剤）
・ＭＥＫ：メチルエチルケトン
・ＣＨＮ：シクロヘキサノン (solvent)
・ MEK: Methyl ethyl ketone ・ CHN: Cyclohexanone
（支持体）
・ＰＥＴフィルム［ピューレックス（登録商標）Ａ５３（帝人デュポンフィルム株式会社製）、５０μｍ厚］
・銅箔［ＧＴＳグレード（古河電気工業株式会社製）、１０５μｍ厚］ (Support)
PET film [Purex (registered trademark) A53 (manufactured by Teijin DuPont Films Ltd.), 50 μm thickness]
Copper foil [GTS grade (Furukawa Electric Co., Ltd.), 105 μm thickness]
（実施例１）
＜樹脂ワニスの作製＞
　エポキシ樹脂モノマー（樹脂モノマーＡ）５．９８部、硬化剤（ＣＲＮ）３．４７部、硬化促進剤（ＴＰＰ）０．０６部、無機フィラー計７２．８５部（ＡＡ－１８：４８．０８部、ＡＡ－３：１７．４８部、ＡＡ－０４：７．２９部）、シランカップリング剤（ＫＢＭ－５７３）０．０８部、及び溶剤計１７．５６部（ＭＥＫ：１４．４７部、ＣＨＮ：３．０９部）を混合し、樹脂ワニス１を得た。 (Example 1)
<Production of resin varnish>
Epoxy resin monomer (resin monomer A) 5.98 parts, curing agent (CRN) 3.47 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 part of silane coupling agent (KBM-573), and 17.56 parts of solvent total (MEK: 14.47 parts, CHN) : 3.09 parts) to obtain a resin varnish 1.
　α－アルミナフィラーの密度を３．９８ｇ／ｃｍ３、樹脂モノマーＡとＣＲＮとの混合物の密度を１．２０ｇ／ｃｍ３として、固形分の合計体積に対する無機フィラーの割合を算出したところ、７４体積％であった。 When the density of the α-alumina filler was 3.98 g / cm 3 and the density of the mixture of the resin monomer A and CRN was 1.20 g / cm 3 , the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
＜樹脂シートの作製＞
　上記で作製した樹脂ワニス１を、アプリケーターを用いて半硬化体の厚みが１５０μｍとなるようにＰＥＴフィルム上に塗布した後、１２０℃で１０分間、１５０℃で３分間の乾燥も兼ねた加熱処理を行い、樹脂シート１を得た。 <Production of resin sheet>
After applying the resin varnish 1 produced above onto a PET film using an applicator so that the thickness of the semi-cured product is 150 μm, the heat treatment also serves as drying at 120 ° C. for 10 minutes and 150 ° C. for 3 minutes. The resin sheet 1 was obtained.
＜無機フィラーの含有率の測定＞
　樹脂シート１中の無機フィラーの含有率を測定したところ、７４体積％であった。 <Measurement of content of inorganic filler>
It was 74 volume% when the content rate of the inorganic filler in the resin sheet 1 was measured.
＜オリゴマー体の重量平均分子量（Ｍｗ）の測定＞
　まず、上記樹脂シート１をテトラヒドロフランに浸漬し、半日（１２時間）常温にて放置した。その後、テトラヒドロフラン可溶分を０．４５μｍメンブランフィルターにて濾過し、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）装置を用い、濾液について下記の測定条件にてＭｗを測定した。
　その結果、樹脂シート１のオリゴマー体のＭｗは１６１１であった。
　なお、オリゴマー体のＭｗは、原料であるエポキシ樹脂モノマー由来のピークより高分子領域にあるピークについて算出した。ゲルパーミエーションクロマトグラフィー（ＧＰＣ）測定のチャートを図１に示す。 <Measurement of weight average molecular weight (Mw) of oligomer>
First, the resin sheet 1 was immersed in tetrahydrofuran and left at room temperature for half a day (12 hours). Thereafter, the tetrahydrofuran-soluble component was filtered through a 0.45 μm membrane filter, and Mw of the filtrate was measured under the following measurement conditions using a gel permeation chromatography (GPC) apparatus.
As a result, Mw of the oligomer body of the resin sheet 1 was 1611.
The Mw of the oligomer was calculated for the peak in the polymer region from the peak derived from the raw material epoxy resin monomer. A chart of gel permeation chromatography (GPC) measurement is shown in FIG.
〔測定条件〕
カラム：東ソー株式会社製、Ｇ４０００ＨＨＲ＋Ｇ３０００ＨＨＲ＋Ｇ２０００ＨＨＲ
カラム温度：４０℃
溶離液：テトラヒドロフラン
流速：１．０ｍＬ／分
試料濃度：５ｇ／Ｌ（テトラヒドロフラン可溶分）
注入量：１００μＬ
検出器：示差屈折計（ＲＩ）
分子量較正標準物質：標準ポリスチレン
データ処理装置：東ソー株式会社製、ＧＰＣ－８０２０ 〔Measurement condition〕
Column: manufactured by Tosoh Corporation, G4000H HR + G3000H HR + G2000H HR
Column temperature: 40 ° C
Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 5 g / L (tetrahydrofuran solubles)
Injection volume: 100 μL
Detector: Differential refractometer (RI)
Molecular weight calibration standard: Standard polystyrene data processor: GPC-8020, manufactured by Tosoh Corporation
＜吸熱ピーク面積の測定＞
　上記樹脂シート１をアルミニウム製のパンに封入し、示差走査熱量（ＤＳＣ）測定装置を用い、下記の測定条件にて吸熱ピーク面積を測定した。
　その結果、樹脂シート１の吸熱ピーク面積は１．９Ｊ／ｇであった。示差走査熱量（ＤＳＣ）測定のチャート及び吸熱ピーク面積の算出部分を図２Ａに示す。図２Ａの横軸は温度（℃）を示し、縦軸は単位質量当たりの熱流（Ｗ／ｇ）を示す。 <Measurement of endothermic peak area>
The resin sheet 1 was sealed in an aluminum pan, and the endothermic peak area was measured using a differential scanning calorimetry (DSC) measuring device under the following measurement conditions.
As a result, the endothermic peak area of the resin sheet 1 was 1.9 J / g. FIG. 2A shows a differential scanning calorimetry (DSC) measurement chart and an endothermic peak area calculation portion. The horizontal axis of FIG. 2A indicates temperature (° C.), and the vertical axis indicates heat flow (W / g) per unit mass.
〔測定条件〕
装置：株式会社パーキンエルマー製、Ｐｙｒｉｓ１
測定範囲：３０℃～３００℃
昇温速度：４０℃／分
試料量：４０ｍｇ～４５ｍｇ 〔Measurement condition〕
Apparatus: Pyris 1 manufactured by Perkin Elmer Co., Ltd.
Measurement range: 30 ° C to 300 ° C
Rate of temperature increase: 40 ° C./min Sample amount: 40 mg to 45 mg
＜熱重量減少率の測定＞
　上記樹脂シート１を４ｃｍ角に切り出し、１９０℃の恒温槽で２時間加熱し、加熱前後のサンプル質量より、以下の式にて熱重量減少率を算出した。
　半硬化体の熱重量減少率（質量％）＝｛（加熱前のサンプル質量－加熱後のサンプル質量）／加熱前のサンプル質量｝×１００
　その結果、樹脂シート１の熱重量減少率は０．１４質量％であった。 <Measurement of thermal weight loss rate>
The resin sheet 1 was cut into 4 cm square, heated in a thermostatic bath at 190 ° C. for 2 hours, and the thermal weight reduction rate was calculated from the sample mass before and after heating by the following formula.
Decrease rate of thermal weight of semi-cured product (mass%) = {(sample mass before heating−sample mass after heating) / sample mass before heating} × 100
As a result, the thermal weight reduction rate of the resin sheet 1 was 0.14% by mass.
＜発熱ピーク面積の測定＞
　上記樹脂シート１をアルミニウム製のパンに封入し、示差走査熱量（ＤＳＣ）測定装置を用い、下記の測定条件にて発熱ピーク面積を測定した。
　その結果、樹脂シート１の発熱ピーク面積は１７．３Ｊ／ｇであった。示差走査熱量（ＤＳＣ）測定のチャート及び発熱ピーク面積の算出部分を図２Ｂに示す。図２Ｂの横軸は温度（℃）を示し、縦軸は単位質量当たりの熱流（Ｗ／ｇ）を示す。 <Measurement of exothermic peak area>
The resin sheet 1 was sealed in an aluminum pan, and the exothermic peak area was measured using a differential scanning calorimetry (DSC) measuring device under the following measurement conditions.
As a result, the exothermic peak area of the resin sheet 1 was 17.3 J / g. FIG. 2B shows a differential scanning calorimetry (DSC) measurement chart and an exothermic peak area calculation part. The horizontal axis of FIG. 2B indicates temperature (° C.), and the vertical axis indicates heat flow (W / g) per unit mass.
〔測定条件〕
装置：株式会社パーキンエルマー製、Ｐｙｒｉｓ１
測定範囲：３０℃～３００℃
昇温速度：４０℃／分
試料量：４０ｍｇ～４５ｍｇ 〔Measurement condition〕
Apparatus: Pyris 1 manufactured by Perkin Elmer Co., Ltd.
Measurement range: 30 ° C to 300 ° C
Rate of temperature increase: 40 ° C./min Sample amount: 40 mg to 45 mg
＜常温での柔軟性の評価＞
　上記樹脂シート１を３ｃｍ×１２ｃｍに切り出し、２０℃～２５℃の環境下にてマンドレル試験機の直径４ｃｍの部分に巻き付け、割れが発生するか否かを調べた。
　その結果、樹脂シート１は割れが発生しなかった。
　なお、表１及び表２では、割れが発生しないものをＡ、割れが発生したものをＢと表示している。 <Evaluation of flexibility at room temperature>
The resin sheet 1 was cut out to 3 cm × 12 cm, wound around a 4 cm diameter portion of a mandrel tester in an environment of 20 ° C. to 25 ° C., and examined whether cracks occurred.
As a result, the resin sheet 1 was not cracked.
In Tables 1 and 2, “A” indicates that no cracking occurs, and “B” indicates that cracking occurs.
＜硬化体の作製＞
　まず、上記樹脂シート１を２枚、真空プレスにて真空圧着（温度：１５０℃、真空度：１ｋＰａ、プレス圧：１ＭＰａ、処理時間：１分間）することで貼り合わせた。続いて、ＰＥＴフィルムを剥がし、２枚の銅箔で、そのマット面がそれぞれ貼り合わせたものに対向するようにして挟み、真空プレスにて真空圧着（温度：１８０℃、真空度：１ｋＰａ、プレス圧：４ＭＰａ、処理時間：５分間）を行った。その後、大気圧条件下、１８０℃で４時間加熱し、銅箔付きの硬化体１を得た。 <Production of cured body>
First, the two resin sheets 1 were bonded together by vacuum pressure bonding (temperature: 150 ° C., degree of vacuum: 1 kPa, press pressure: 1 MPa, treatment time: 1 minute) using a vacuum press. Subsequently, the PET film is peeled off and sandwiched between two copper foils so that the mat surfaces face each other and bonded together by vacuum pressing (temperature: 180 ° C., degree of vacuum: 1 kPa, press) Pressure: 4 MPa, treatment time: 5 minutes). Then, it heated at 180 degreeC under atmospheric pressure conditions for 4 hours, and obtained the hardening body 1 with a copper foil.
＜熱伝導率の測定＞
　上記で得られた硬化体１の銅箔をエッチングにより取り除き、樹脂シート型の硬化体１を得た。得られた硬化体１を１０ｍｍ角に切り出してグラファイトスプレーにて黒化処理した後、キセノンフラッシュ法（ＮＥＴＺＳＣＨ社製、ＬＦＡ４４７　ｎａｎｏｆｌａｓｈ）を用いて熱拡散率を評価した。この値と、示差走査熱量（ＤＳＣ）測定装置（株式会社パーキンエルマー製、Ｐｙｒｉｓ１）で測定した比熱と、アルキメデス法で測定した密度と、の積から硬化体１の熱伝導率を求めた。
　その結果、硬化体１の熱伝導率は１０．０Ｗ／（ｍ・Ｋ）であった。 <Measurement of thermal conductivity>
The copper foil of the cured body 1 obtained above was removed by etching to obtain a resin sheet type cured body 1. The obtained cured body 1 was cut into a 10 mm square and blackened with a graphite spray, and then the thermal diffusivity was evaluated using a xenon flash method (manufactured by NETZSCH, LFA447 nanoflash). The thermal conductivity of the cured body 1 was determined from the product of this value and the specific heat measured with a differential scanning calorie (DSC) measuring device (Pyris 1 manufactured by Perkin Elmer Co., Ltd.) and the density measured by the Archimedes method.
As a result, the thermal conductivity of the cured body 1 was 10.0 W / (m · K).
（実施例２）
　実施例１と同様にして樹脂ワニス２を作製し、その他の工程もほぼ同様にして樹脂シート２及び硬化体２を作製し、実施例１と同様にして評価した。結果を表１に示す。 (Example 2)
A resin varnish 2 was prepared in the same manner as in Example 1, and the resin sheet 2 and the cured body 2 were prepared in substantially the same manner in the other steps, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
（実施例３）
　実施例１と同様にして樹脂ワニス３を作製し、その他の工程もほぼ同様にして樹脂シート３及び硬化体３を作製し、実施例１と同様にして評価した。結果を表１に示す。 (Example 3)
A resin varnish 3 was prepared in the same manner as in Example 1, and the resin sheet 3 and the cured body 3 were prepared in substantially the same manner in the other steps, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
（実施例４）
　エポキシ樹脂モノマー（樹脂モノマーＢ）５．８３部、硬化剤（ＣＲＮ）３．７７部、硬化促進剤（ＴＰＰ）０．０６部、無機フィラー計７２．８５部（ＡＡ－１８：４８．０８部、ＡＡ－３：１７．４８部、ＡＡ－０４：７．２９部）、シランカップリング剤（ＫＢＭ－５７３）０．０８部、及び溶剤計１７．４１部（ＭＥＫ：１４．４７部、ＣＨＮ：２．９４部）を混合し、樹脂ワニス４を得た。 Example 4
Epoxy resin monomer (resin monomer B) 5.83 parts, curing agent (CRN) 3.77 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 parts of silane coupling agent (KBM-573), and 17.41 parts of solvent meter (MEK: 14.47 parts, CHN) : 2.94 parts) to obtain a resin varnish 4.
　α－アルミナフィラーの密度を３．９８ｇ／ｃｍ３、樹脂モノマーＢとＣＲＮとの混合物の密度を１．２０ｇ／ｃｍ３として、固形分の合計体積に対する無機フィラーの割合を算出したところ、７４体積％であった。 When the density of the α-alumina filler was 3.98 g / cm 3 and the density of the mixture of the resin monomer B and CRN was 1.20 g / cm 3 , the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
　上記で得られた樹脂ワニス４を用いたこと以外は、実施例１と同様にして樹脂シート４及び硬化体４を作製し、実施例１と同様にして評価した。結果を表１に示す。 Resin sheet 4 and cured body 4 were prepared in the same manner as in Example 1 except that the resin varnish 4 obtained above was used, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
（実施例５）
　エポキシ樹脂モノマー（樹脂モノマーＣ）５．６３部、硬化剤（ＣＲＮ）４．１８部、硬化促進剤（ＴＰＰ）０．０６部、無機フィラー計７２．８５部（ＡＡ－１８：４８．０８部、ＡＡ－３：１７．４８部、ＡＡ－０４：７．２９部）、シランカップリング剤（ＫＢＭ－５７３）０．０８部、及び溶剤計１７．２０部（ＭＥＫ：１４．４７部、ＣＨＮ：２．７３部）を混合し、樹脂ワニス５を得た。 (Example 5)
Epoxy resin monomer (resin monomer C) 5.63 parts, curing agent (CRN) 4.18 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 part of silane coupling agent (KBM-573), and 17.20 parts of solvent meter (MEK: 14.47 parts, CHN) : 2.73 parts) to obtain a resin varnish 5.
　α－アルミナフィラーの密度を３．９８ｇ／ｃｍ３、樹脂モノマーＣとＣＲＮとの混合物の密度を１．２０ｇ／ｃｍ３として、固形分の合計体積に対する無機フィラーの割合を算出したところ、７４体積％であった。 When the density of the α-alumina filler was 3.98 g / cm 3 and the density of the mixture of the resin monomer C and CRN was 1.20 g / cm 3 , the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
　上記で得られた樹脂ワニス５を用いたこと以外は、実施例１と同様にして樹脂シート５及び硬化体５を作製し、実施例１と同様にして評価した。結果を表１に示す。 Resin sheet 5 and cured body 5 were prepared in the same manner as in Example 1 except that the resin varnish 5 obtained above was used, and evaluated in the same manner as in Example 1. The results are shown in Table 1.
（実施例６）
　エポキシ樹脂モノマー（樹脂モノマーＡ）７．６９部、硬化剤（ＣＲＮ）４．４８部、硬化促進剤（ＴＰＰ）０．０８部、無機フィラー計５４．１６部（ＨＰ－４０：２８．０３部、ＡＡ－３：１８．４４部、ＡＡ－０４：７．６９部）、シランカップリング剤（ＫＢＭ－５７３）０．０８部、及び溶剤（ＣＨＮ）３３．５１部を混合し、樹脂ワニス６を得た。
　窒化ホウ素フィラーの密度を２．２０／ｃｍ３、α－アルミナフィラーの密度を３．９８ｇ／ｃｍ３、樹脂モノマーＡとＣＲＮとの混合物の密度を１．２０ｇ／ｃｍ３として、固形分の合計体積に対する無機フィラー（窒化ホウ素フィラー及びα－アルミナフィラー）の割合を算出したところ、７０体積％であった。 (Example 6)
7.69 parts of epoxy resin monomer (resin monomer A), 4.48 parts of curing agent (CRN), 0.08 part of curing accelerator (TPP), a total of 54.16 parts of inorganic filler (HP-40: 28.03 parts) , AA-3: 18.44 parts, AA-04: 7.69 parts), 0.08 part of a silane coupling agent (KBM-573), and 33.51 parts of a solvent (CHN) were mixed to obtain resin varnish 6 Got.
The density of the boron nitride filler is 2.20 / cm 3 , the density of the α-alumina filler is 3.98 g / cm 3 , and the density of the mixture of the resin monomer A and CRN is 1.20 g / cm 3. The ratio of the inorganic filler (boron nitride filler and α-alumina filler) to the volume was calculated to be 70% by volume.
　工程に関しては、半硬化体６の貼りあわせの際の真空プレスの条件（温度：１５０℃、真空度：１ｋＰａ、プレス圧：１５ＭＰａ、処理時間：１分間）、及び銅箔を圧着させる際の真空プレスの条件（温度：１８０℃、真空度：１ｋＰａ、プレス圧：１５ＭＰａ、処理時間：５分間）以外は、実施例１と同様にして樹脂シート６及び硬化体６を作製し、実施例１と同様にして評価した。結果を表１に示す。 Regarding the process, the vacuum press conditions (temperature: 150 ° C., degree of vacuum: 1 kPa, press pressure: 15 MPa, processing time: 1 minute) at the time of bonding the semi-cured body 6, and the vacuum when the copper foil is pressure-bonded Resin sheet 6 and cured body 6 were produced in the same manner as in Example 1 except for the press conditions (temperature: 180 ° C., vacuum: 1 kPa, press pressure: 15 MPa, treatment time: 5 minutes). Evaluation was performed in the same manner. The results are shown in Table 1.
（比較例１）
　実施例１と同様にして樹脂ワニス７を作製し、樹脂ワニスの塗布後、１００℃で１０分間の乾燥も兼ねた加熱処理を行った以外は、実施例１と同様にして樹脂シート７及び硬化体７を作製し、実施例１と同様にして評価した。結果を表２に示す。 (Comparative Example 1)
Resin varnish 7 was prepared in the same manner as in Example 1, and after application of the resin varnish, a heat treatment that also served drying at 100 ° C. for 10 minutes was performed, and the resin sheet 7 and cured as in Example 1. A body 7 was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.
（比較例２）
　実施例１と同様にして樹脂ワニス８を作製し、樹脂ワニスの塗布後、１５０℃で５分間の乾燥も兼ねた加熱処理を行った以外は、実施例１と同様にして樹脂シート８及び硬化体８を作製し、実施例１と同様にして評価した。結果を表２に示す。 (Comparative Example 2)
Resin varnish 8 was prepared in the same manner as in Example 1, and after application of the resin varnish, a heat treatment that also served drying at 150 ° C. for 5 minutes was performed, and the resin sheet 8 and cured as in Example 1. A body 8 was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.
（比較例３）
　実施例１と同様にして樹脂ワニス９を作製し、樹脂ワニスの塗布後、溶剤等の揮発分が揮発しにくい環境で、１２０℃で１０分間、１５０℃で３分間の乾燥も兼ねた加熱処理を行った以外は、実施例１と同様にして樹脂シート９及び硬化体９を作製し、実施例１と同様にして評価した。結果を表２に示す。 (Comparative Example 3)
Resin varnish 9 was prepared in the same manner as in Example 1, and after the application of the resin varnish, in an environment in which volatile components such as solvents are difficult to volatilize, heat treatment was also performed for drying at 120 ° C. for 10 minutes and 150 ° C. for 3 minutes. A resin sheet 9 and a cured product 9 were produced in the same manner as in Example 1 except that the evaluation was performed and evaluated in the same manner as in Example 1. The results are shown in Table 2.
（比較例４）
　エポキシ樹脂モノマー（樹脂モノマーＤ）５．７５部、硬化剤（ＣＲＮ）３．９４部、硬化促進剤（ＴＰＰ）０．０６部、無機フィラー計７２．８５部（ＡＡ－１８：４８．０８部、ＡＡ－３：１７．４８部、ＡＡ－０４：７．２９部）、シランカップリング剤（ＫＢＭ－５７３）０．０８部、及び溶剤計１７．３２部（ＭＥＫ：１４．４７部、ＣＨＮ：２．８５部）を混合し、樹脂ワニス１０を得た。 (Comparative Example 4)
Epoxy resin monomer (resin monomer D) 5.75 parts, curing agent (CRN) 3.94 parts, curing accelerator (TPP) 0.06 parts, inorganic filler total 72.85 parts (AA-18: 48.08 parts) , AA-3: 17.48 parts, AA-04: 7.29 parts), 0.08 part of silane coupling agent (KBM-573), and 17.32 parts of solvent meter (MEK: 14.47 parts, CHN) : 2.85 parts) to obtain a resin varnish 10.
　α－アルミナフィラーの密度を３．９８ｇ／ｃｍ３、樹脂モノマーＤとＣＲＮとの混合物の密度を１．２０ｇ／ｃｍ３として、固形分の合計体積に対する無機フィラーの割合を算出したところ、７４体積％であった。 When the density of the α-alumina filler was 3.98 g / cm 3 and the density of the mixture of the resin monomer D and CRN was 1.20 g / cm 3 , the ratio of the inorganic filler to the total volume of the solid content was calculated to be 74 volumes. %Met.
　上記で得られた樹脂ワニス１０を用いたこと以外は、実施例１と同様にして樹脂シート１０及び硬化体１０を作製し、実施例１と同様にして評価した。結果を表２に示す。 The resin sheet 10 and the cured body 10 were produced in the same manner as in Example 1 except that the resin varnish 10 obtained above was used, and evaluated in the same manner as in Example 1. The results are shown in Table 2.
（比較例５）
　実施例１と同様にして樹脂ワニス１１を作製し、樹脂ワニスの塗布後、１５０℃で１０分間の乾燥も兼ねた加熱処理を行った以外は、実施例１と同様にして樹脂シート１１及び硬化体１１を作製し、実施例１と同様にして評価した。結果を表２に示す。 (Comparative Example 5)
Resin varnish 11 was prepared in the same manner as in Example 1, and after application of the resin varnish, a heat treatment that also served drying at 150 ° C. for 10 minutes was performed, and in the same manner as in Example 1, the resin sheet 11 and cured A body 11 was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.
Figure JPOXMLDOC01-appb-T000031
Figure JPOXMLDOC01-appb-T000031
Figure JPOXMLDOC01-appb-T000032
Figure JPOXMLDOC01-appb-T000032
　表１に示すとおり、実施例１～６の樹脂シートは常温での柔軟性に優れており、かつ硬化体は高い熱伝導性を有するものであった。
　一方、表２に示すとおり、オリゴマー体の重量平均分子量が３０００超である比較例１、５の樹脂シート、及び吸熱ピーク面積が２．５Ｊ／ｇ超である比較例２の樹脂シートは、常温での柔軟性に劣っていた。また、樹脂シートの熱重量減少率が０．４質量％超であった比較例３の硬化体、及びメソゲン骨格を有するエポキシ樹脂モノマーを用いなかった比較例４の硬化体は、熱伝導率が低いものであった。 As shown in Table 1, the resin sheets of Examples 1 to 6 were excellent in flexibility at room temperature, and the cured body had high thermal conductivity.
On the other hand, as shown in Table 2, the resin sheets of Comparative Examples 1 and 5 in which the weight-average molecular weight of the oligomer is over 3000 and the resin sheet of Comparative Example 2 in which the endothermic peak area is over 2.5 J / g are room temperature. It was inferior in flexibility. In addition, the cured product of Comparative Example 3 in which the thermal weight reduction rate of the resin sheet was more than 0.4% by mass and the cured product of Comparative Example 4 that did not use the epoxy resin monomer having a mesogen skeleton had a thermal conductivity. It was low.
　２０１４年１２月１５日に出願された日本出願２０１４－２５３３５６の開示はその全体が参照により本明細書に取り込まれる。
　本明細書に記載された全ての文献、特許出願、及び技術規格は、個々の文献、特許出願、及び技術規格が参照により取り込まれることが具体的かつ個々に記された場合と同程度に、本明細書中に参照により取り込まれる。 The disclosure of Japanese application 2014-253356 filed on Dec. 15, 2014 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims (12)

  1. 　メソゲン骨格を有するエポキシ樹脂モノマー及びそのオリゴマー体と、ノボラック樹脂を含む硬化剤と、無機フィラーと、を含有し、
    　前記オリゴマー体は、前記メソゲン骨格を有するエポキシ樹脂モノマーと前記ノボラック樹脂との反応物を含み、
    　ゲルパーミエーションクロマトグラフィー測定における前記オリゴマー体の重量平均分子量が１０００～３０００であり、
    　示差走査熱量測定における吸熱ピーク面積が２．５Ｊ／ｇ以下であり、
    　４ｃｍ×４ｃｍ×１５０μｍのサンプルを１９０℃の恒温槽で２時間加熱したときの熱重量減少率が０．４質量％以下であるエポキシ樹脂組成物。     An epoxy resin monomer having a mesogenic skeleton and an oligomer thereof, a curing agent containing a novolac resin, and an inorganic filler,
    The oligomer body includes a reaction product of the epoxy resin monomer having the mesogenic skeleton and the novolak resin,
    The weight average molecular weight of the oligomer in the gel permeation chromatography measurement is 1000 to 3000,
    The endothermic peak area in differential scanning calorimetry is 2.5 J / g or less,
    An epoxy resin composition having a thermal weight loss rate of 0.4% by mass or less when a sample of 4 cm × 4 cm × 150 μm is heated in a thermostat at 190 ° C. for 2 hours.
  2. 　示差走査熱量測定における発熱ピーク面積が１２．８Ｊ／ｇ～２０．５Ｊ／ｇである請求項１に記載のエポキシ樹脂組成物。 The epoxy resin composition according to claim 1, wherein the exothermic peak area in differential scanning calorimetry is 12.8 J / g to 20.5 J / g.
  3. 　前記メソゲン骨格を有するエポキシ樹脂モノマーが、下記一般式（Ｉ－１）で表される化合物を含む請求項１又は請求項２に記載のエポキシ樹脂組成物。
    Figure JPOXMLDOC01-appb-C000001
         The epoxy resin composition according to claim 1 or 2, wherein the epoxy resin monomer having a mesogenic skeleton contains a compound represented by the following general formula (I-1).
    Figure JPOXMLDOC01-appb-C000001
  4. 　前記ノボラック樹脂が、下記一般式（ＩＩ－１）及び（ＩＩ－２）からなる群より選択される少なくとも１つで表される構造単位を有する化合物を含む請求項１～請求項３のいずれか１項に記載のエポキシ樹脂組成物。
    Figure JPOXMLDOC01-appb-C000002
    ［一般式（ＩＩ－１）及び（ＩＩ－２）中、Ｒ２１及びＲ２４はそれぞれ独立に、アルキル基、アリール基、又はアラルキル基を示し、該アルキル基、アリール基、及びアラルキル基は置換基を有していてもよい。Ｒ２２、Ｒ２３、Ｒ２５、及びＲ２６はそれぞれ独立に、水素原子、アルキル基、アリール基、又はアラルキル基を示し、該アルキル基、アリール基、及びアラルキル基は置換基を有していてもよい。ｍ２１及びｍ２２はそれぞれ独立に０～２の整数を示す。ｎ２１及びｎ２２はそれぞれ独立に１～７の整数を示す。］     4. The method according to claim 1, wherein the novolak resin includes a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (II-1) and (II-2). 2. The epoxy resin composition according to item 1.
    Figure JPOXMLDOC01-appb-C000002
    [In the general formulas (II-1) and (II-2), R 21 and R 24 each independently represents an alkyl group, an aryl group, or an aralkyl group, and the alkyl group, aryl group, and aralkyl group are substituted. It may have a group. R 22 , R 23 , R 25 , and R 26 each independently represent a hydrogen atom, an alkyl group, an aryl group, or an aralkyl group, and the alkyl group, aryl group, and aralkyl group each have a substituent. Also good. m21 and m22 each independently represents an integer of 0-2. n21 and n22 each independently represents an integer of 1 to 7. ]
  5. 　前記ノボラック樹脂が、下記一般式（ＩＩＩ－１）～（ＩＩＩ－４）からなる群より選択される少なくとも１つで表される構造単位を有する化合物を含む請求項１～請求項３のいずれか１項に記載のエポキシ樹脂組成物。
    Figure JPOXMLDOC01-appb-C000003
    Figure JPOXMLDOC01-appb-C000004
    Figure JPOXMLDOC01-appb-C000005
    Figure JPOXMLDOC01-appb-C000006
    ［一般式（ＩＩＩ－１）～（ＩＩＩ－４）中、ｍ３１～ｍ３４及びｎ３１～ｎ３４はそれぞれ独立に、正の整数を示す。Ａｒ３１～Ａｒ３４はそれぞれ独立に、下記一般式（ＩＩＩ－ａ）で表される基又は下記一般式（ＩＩＩ－ｂ）で表される基を示す。］
    Figure JPOXMLDOC01-appb-C000007
    ［一般式（ＩＩＩ－ａ）及び（ＩＩＩ－ｂ）中、Ｒ３１及びＲ３４はそれぞれ独立に、水素原子又は水酸基を示す。Ｒ３２及びＲ３３はそれぞれ独立に、水素原子又は炭素数１～８のアルキル基を示す。］     4. The method according to claim 1, wherein the novolak resin includes a compound having a structural unit represented by at least one selected from the group consisting of the following general formulas (III-1) to (III-4): 2. The epoxy resin composition according to item 1.
    Figure JPOXMLDOC01-appb-C000003
    Figure JPOXMLDOC01-appb-C000004
    Figure JPOXMLDOC01-appb-C000005
    Figure JPOXMLDOC01-appb-C000006
    [In the general formulas (III-1) to (III-4), m31 to m34 and n31 to n34 each independently represent a positive integer. Ar 31 to Ar 34 each independently represent a group represented by the following general formula (III-a) or a group represented by the following general formula (III-b). ]
    Figure JPOXMLDOC01-appb-C000007
    [In the general formulas (III-a) and (III-b), R 31 and R 34 each independently represents a hydrogen atom or a hydroxyl group. R 32 and R 33 each independently represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. ]
  6. 　前記無機フィラーの含有率が、６０体積％～９０体積％である請求項１～請求項５のいずれか１項に記載のエポキシ樹脂組成物。 The epoxy resin composition according to any one of claims 1 to 5, wherein a content of the inorganic filler is 60% by volume to 90% by volume.
  7. 　前記無機フィラーが、アルミナ、窒化ホウ素、シリカ、酸化マグネシウム、窒化アルミニウム、及びマイカからなる群より選択される少なくとも１つの粒子である請求項１～請求項６のいずれか１項に記載のエポキシ樹脂組成物。 The epoxy resin according to any one of claims 1 to 6, wherein the inorganic filler is at least one particle selected from the group consisting of alumina, boron nitride, silica, magnesium oxide, aluminum nitride, and mica. Composition.
  8. 　請求項１～請求項７のいずれか１項に記載のエポキシ樹脂組成物のシート状成形体である樹脂シート。 A resin sheet which is a sheet-like molded body of the epoxy resin composition according to any one of claims 1 to 7.
  9. 　繊維基材と、請求項１～請求項７のいずれか１項に記載のエポキシ樹脂組成物を含む樹脂マトリックスと、を有するプリプレグ。 A prepreg having a fiber base material and a resin matrix containing the epoxy resin composition according to any one of claims 1 to 7.
  10. 　被着材と、
    　前記被着材上に配置され、請求項１～請求項７のいずれか１項に記載のエポキシ樹脂組成物、請求項８に記載の樹脂シート、及び請求項９に記載のプリプレグからなる群より選択される少なくとも１つの半硬化体である半硬化層又は硬化体である硬化層と、を有する積層板。     A substrate,
    From the group consisting of the epoxy resin composition according to any one of claims 1 to 7, the resin sheet according to claim 8, and the prepreg according to claim 9 disposed on the adherend. A laminate having a semi-cured layer that is at least one semi-cured body or a cured layer that is a cured body.
  11. 　メソゲン骨格を有するエポキシ樹脂モノマーと、ノボラック樹脂を含む硬化剤と、無機フィラーと、を含有する組成物を熱処理し、前記メソゲン骨格を有するエポキシ樹脂モノマーのオリゴマー体を生成させて請求項１～請求項７のいずれか１項に記載のエポキシ樹脂組成物を得る工程を含むエポキシ樹脂組成物の製造方法。 A composition containing an epoxy resin monomer having a mesogen skeleton, a curing agent containing a novolak resin, and an inorganic filler is heat-treated to produce an oligomer of the epoxy resin monomer having the mesogen skeleton. Item 8. A method for producing an epoxy resin composition, comprising a step of obtaining the epoxy resin composition according to any one of items 7.
  12. 　請求項１～請求項７のいずれか１項に記載のエポキシ樹脂組成物、請求項８に記載の樹脂シート、又は請求項９に記載のプリプレグを硬化させた硬化体。 A cured product obtained by curing the epoxy resin composition according to any one of claims 1 to 7, the resin sheet according to claim 8, or the prepreg according to claim 9.
PCT/JP2015/084842 2014-12-15 2015-12-11 Epoxy resin composition, resin sheet, prepreg, laminate, process for producing epoxy resin composition, and cured object WO2016098709A1 (en)

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