Active ester resin, production method therefor, epoxy resin composition, cured object of epoxy resin composition, prepreg, resin sheet, laminate, and material for circuit board

Abstract

Provided is a resin composition such that a resultant active ester has excellent solubility in solvents and a cured object exhibits excellent heat resistance and dielectric properties.　This active ester resin comprises polyaryloxy units, monoaryloxy units, and polyarylcarbonyl units, and is characterized in that the polyaryloxy units include a structure derived from an aromatic polyhydroxy compound and represented by formula (1), and the content of the structure derived from an aromatic polyhydroxy compound and represented by formula (1) in the polyaryloxy units is higher than 10 mol% but not higher than 60 mol%. In formula (1), the R1 moieties each independently represent a C1-C8 hydrocarbon group and i is an integer of 0-3.

Description

Active ester resins and methods for producing the same, epoxy resin compositions, cured epoxy resin compositions, prepregs, resin sheets, laminates, and materials for circuit boards.

[0001] This invention relates to an active ester resin with excellent dielectric properties and adhesiveness, a method for producing the same, and epoxy resin compositions using the active ester resin, cured products of epoxy resin compositions, prepregs, resin sheets, laminates, and materials for circuit boards.

[0002] Epoxy resins are used in a wide range of applications, including paints, civil engineering adhesives, casting, electrical and electronic materials, and film materials, due to their excellent adhesive properties, flexibility, heat resistance, chemical resistance, insulation, and curing reaction. In particular, they are widely used in printed circuit board applications, a type of electrical and electronic material, by imparting flame retardancy to epoxy resins.

[0003] In recent years, information devices have become smaller and more high-performance at an accelerating pace, and consequently, materials used in the fields of semiconductors and electronic components are required to have higher performance than ever before. In particular, epoxy resin compositions used as materials for electrical and electronic components require low dielectric properties to accommodate the thinning and high-performance nature of substrates.

[0004] To achieve low dielectric properties in such epoxy resin compositions, Patent Document 1 reports that by using an activated ester compound obtained by reacting phenols with aromatic dicarboxylic acid halides and curing it with epoxy resin, a cured product with excellent low dielectric properties can be obtained.

[0005] Patent Document 2 reports an active ester resin in which heat resistance, low dielectric properties, and solvent solubility are enhanced by reacting dicyclopentadiene-type aromatic polyvalent hydroxy compounds and monohydroxy compounds as phenols with aromatic dicarboxylic acid halides.

[0006] Patent documents 3 and 4 report polyarylate resins comprising a divalent phenol component and an aromatic dicarbon component of a specific structure, which, although having a high glass transition temperature, can be used to obtain polyarylate resins that are reactive with epoxy resins.

[0007] However, the activated ester resins disclosed in these documents did not fully satisfy the performance requirements based on the increasing functionality of modern materials, and were insufficient to ensure solubility in solvents, low dielectric properties, and heat resistance.

[0008] Japanese Patent Publication No. 2004-277461 Japanese Patent Publication No. 2009-235165 Japanese Patent Publication No. 6193574 Japanese Patent Publication No. 7217472

[0009] Therefore, the problem that the present invention aims to solve is to provide a resin composition in which the resulting active ester resin exhibits excellent solvent solubility, and further exhibits excellent heat resistance and dielectric properties in the cured product.

[0010] To solve the above problems, the present inventors discovered that when polyaryloxy units containing a polyvalent phenol structure of a specific structure are activated esterified, the resulting activated ester resin exhibits excellent solvent solubility, and when cured with epoxy resin, the resulting cured product exhibits excellent heat resistance and low dielectric properties, thus completing the present invention.

[0011] In other words, the present invention relates to an active ester resin comprising polyaryloxy units, monoaryloxy units, and polyarylcarbonyl units, wherein the polyaryloxy units contain a structure derived from an aromatic polyhydric hydroxy compound represented by the following formula (1), and the content of the structure derived from the aromatic polyhydric hydroxy compound represented by the following formula (1) in the polyaryloxy units is more than 10 mol% and 60 mol% or less. Here, R １ Each of these independently represents a hydrocarbon group having 1 to 8 carbon atoms. i is an integer from 0 to 3.

[0012] The polyaryloxy unit preferably includes structures derived from aromatic polyhydric hydroxy compounds other than the unit represented by formula (1) above, specifically structures represented by the following formulas (2) and / or (3). Here, Ar １Each is independently an aromatic ring group of any of a benzene ring, a naphthalene ring, a diphenylmethane ring or a biphenyl ring, and these aromatic ring groups may have an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms as a substituent. Ar １１ is a divalent hydrocarbon group having 1 to 12 carbon atoms or a divalent group represented by the formula (2a). R １１ Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. R ３ is a divalent group selected from the group consisting of a direct bond, a hydrocarbon group having 1 to 20 carbon atoms, -CO-, -O-, -S-, -SO ２ -, and -C(CF ３ ) ２ -. m represents the number of repetitions, and the average value thereof is a number from 1 to 5. k is 0 or 1.

[0013] The content of the monoaryloxy unit is preferably 10 mol% or more and 200 mol% or less with respect to the content of the polyaryloxy unit. Further, as the monoaryloxy unit, it is preferable to contain a structure derived from an aromatic monohydroxy compound represented by the following formula (4) or formula (4'). Here, Ar ２ Each is independently an aromatic ring group of any of a benzene ring, a naphthalene ring, a diphenylmethane ring or a biphenyl ring, and these aromatic ring groups may have an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms as a substituent. R ４ is a divalent group selected from the group consisting of a direct bond, a hydrocarbon group having 1 to 20 carbon atoms, -CO-, -O-, -S-, -SO ２ -, and -C(CF ３ ) ２ -. R １４ is -CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３)-, and-C(CF ３ ) ２ It is a divalent group selected from the group consisting of -. k is 0 or 1.

[0014] It is preferable that the polyarylcarbonyl unit is a unit represented by the following formula (5). Here, Ar ３ Each of these is independently an aromatic ring group consisting of a benzene ring, a naphthalene ring, a diphenylmethane ring, or a biphenyl ring, and these aromatic ring groups may have substituents of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. ５ These are directly bonded hydrocarbon groups with 1 to 20 carbon atoms, -CO-, -O-, -S-, and -SO ２ -, and -C(CF ３ ) ２ It is a divalent group selected from the group consisting of -. k is 0 or 1.

[0015] A method for producing an active ester resin from an aromatic hydroxy compound, including an aromatic polyhydric hydroxy compound and an aromatic monohydroxy compound, and an aromatic carboxylic acid or its acid halide, characterized in that the aromatic polyhydric hydroxy compound contains an aromatic polyhydric hydroxy compound represented by the following formula (1'), and the content of the aromatic polyhydric hydroxy compound represented by the following formula (1') in the total aromatic polyhydric hydroxy compound is greater than 10 mol% and less than or equal to 60 mol%. Here, R １ Each of these independently represents a hydrocarbon group having 1 to 8 carbon atoms. i is an integer from 0 to 3.

[0016] Furthermore, the present invention relates to an epoxy resin composition comprising the above-mentioned active ester resin and an epoxy resin as essential components.

[0017] Furthermore, the present invention relates to a cured product obtained by curing the above epoxy resin composition, and to a prepreg, resin sheet, laminate, and circuit board material using the above epoxy resin composition.

[0018] The epoxy resin composition of the present invention exhibits excellent dielectric properties in its cured product, and further provides an epoxy resin composition with excellent copper foil peel strength and interlayer adhesion strength for printed circuit board applications. In particular, it can be suitably used in mobile and server applications where a low dielectric loss tangent is strongly required.

[0019] This is the GPC chart of the activated ester resin obtained in Example 1. This is the IR chart of the activated ester resin obtained in Example 1.

[0020] The embodiments of the present invention will be described in detail below.

[0021] The active ester resin of the present invention is an active ester resin comprising polyaryloxy units, monoaryloxy units, and polyarylcarbonyl units, characterized in that the polyaryloxy units contain a structure derived from an aromatic polyvalent hydroxy compound represented by the above formula (1), and the content of the structure represented by the above formula (1) in the polyaryloxy units is more than 10 mol% and 60 mol% or less. In this specification, monoaralkyloxy groups are also treated as monoaryloxy groups. Here, the content (mol%) indicates the content (mol%) relationship based on the hydroxyl group of the aromatic polyvalent hydroxy compound from which the structure is derived, as described in the examples below. The same applies to the content of polyaryloxy units (aromatic polyvalent hydroxy compounds) and monoaryloxy units (aromatic monohydroxy compounds) described later. Furthermore, the content of polyaryloxycarbonyl units (aromatic polyvalent carboxylic acids or their acid halides) and monoaryloxycarbonyl units (aromatic monocarboxylic acids or their acid halides) indicates the content based on the carboxyl group and / or its acid halogen group relative to the hydroxyl group content. The same applies to the amount used in the manufacturing process.

[0022] The polyaryloxy unit is a structural unit derived from a raw aromatic polyhydric hydroxy compound, including aromatic polyhydric hydroxy compounds, and is represented by formula (1) above. In addition to the structural unit represented by formula (1) above, it may also include structural units derived from aromatic polyhydric hydroxy compounds represented by formula (2) described later, and structural units derived from aromatic polyhydric hydroxy compounds (aromatic dihydroxy compounds) represented by formula (3). Furthermore, the polyarylcarbonyl unit is a structural unit derived from a raw aromatic polycarboxylic acid (or aromatic polycarboxylic acid halide), and as described later, the monoaryloxy unit located at the end of the molecular chain is a structural unit derived from a raw aromatic monohydroxy compound, including an aromatic monohydroxy compound represented by formula (4) or (4') above. In this specification, aromatic polyhydric hydroxy compounds and aromatic monohydroxy compounds may be collectively referred to simply as "aromatic hydroxy compounds." Also, aromatic polycarboxylic acids or their acid halides and aromatic monocarboxylic acids or their acid halides may be collectively referred to simply as "aromatic carboxylic acids or their acid halides."

[0023] The ester bonds in the active ester resin of the present invention have high reactive activity toward epoxy groups, making the active ester resin of the present invention suitable for use as a curing agent for epoxy resins. Furthermore, due to the effect of not generating highly polar hydroxyl groups during curing, the resulting cured product exhibits a low dielectric loss tangent and a low relative permittivity. Moreover, as described above or below, since the molecular chain ends are aryloxycarbonyl groups derived from the compound represented by formula (7) or formula (8) described below, even if the ester bonds at the crosslinking points of the resulting cured product are hydrolyzed by moisture absorption, low molecular weight carboxylic acids that increase the dielectric loss tangent are not released, and the resulting cured product exhibits a low dielectric loss tangent even under high humidity conditions. In addition, since there are many ester bonds within the molecular chain that have reactive activity toward epoxy groups, the secondary hydroxyl groups generated when reacting with the epoxy resin react with the ester bonds within the molecular chain to form a crosslinked structure, resulting in a cured product with a high crosslink density and high heat resistance (glass transition temperature: Tg).

[0024] In the above formula (1), R １The substituent represents a hydrocarbon group having 1 to 8 carbon atoms, and is preferably an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, or an allyl group. The alkyl group having 1 to 8 carbon atoms can be linear, branched, or cyclic, and examples include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl, pentyl, isopentyl, neopentyl, cyclopentyl, hexyl, methylpentyl, dimethylbutane, cyclohexyl, and methylcyclohexyl groups. The aryl group having 6 to 8 carbon atoms can be, but is not limited to, phenyl, tolyl, xylyl, and ethylphenyl groups. The aralkyl group having 7 to 8 carbon atoms can be, but is not limited to, benzyl and α-methylbenzyl groups. Among these substituents, phenyl and methyl groups are preferred from the viewpoint of ease of availability and reactivity when cured, and methyl groups are particularly preferred. １ The substitution position of the substituent R may be ortho, meta, or para relative to the oxy group, but the ortho position is preferred. Furthermore, from the viewpoint of ease of acquisition and reactivity when cured, substituent R １ It is also preferable that there is no substitution (i=0).

[0025] i is the number of substitutions, which is between 0 and 3, preferably 0 or 1.

[0026] The above polyaryloxy units include structural units other than those derived from the aromatic polyvalent hydroxy compound represented by formula (1) above, in an amount of 40 mol% or more and less than 90 mol% based on the hydroxyl group content. These other structural units are preferably those represented by formula (2) and / or formula (3) above. That is, with respect to the total amount of polyaryloxy units constituting the active ester resin of the present invention, the structural units derived from the aromatic polyvalent hydroxy compound represented by formula (1) above are contained in an amount of more than 10 mol% and 60 mol% or less based on the hydroxyl group content. Preferably, it is contained in an amount of 15 mol% or more and 55 mol% or less, and more preferably 20 mol% or more and 50 mol% or less. If it is lower than this range, the dielectric properties and heat resistance of the resulting active ester resin may deteriorate, and if it is higher than this range, the solvent solubility of the resulting active ester may be poor.

[0027] In the above formula (2), Ar １ Each of these independently represents an aromatic ring group consisting of a benzene ring, a naphthalene ring, a diphenylmethane ring, or a biphenyl ring. These aromatic ring groups may consist only of a benzene ring, a naphthalene ring, a diphenylmethane ring, or a biphenyl ring, and the substituent R described later may also be present. ６ [(R ６ )p or (R ６ )q] may have substituent R ６ This is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. １１ is a divalent hydrocarbon group having 1 to 12 carbon atoms or a divalent group represented by formula (2a), and represents the linking group of the novolac resin. Examples of divalent hydrocarbon groups having 1 to 12 carbon atoms include the methylene group and the dicyclopentadienylene group. m indicates the number of repetitions, and its average value is between 1 and 5.

[0028] In the above formula (2a), Ar １ The same applies as described above. Also, R １１Each of these is independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. Examples of hydrocarbon groups having 1 to 8 carbon atoms include alkyl groups having 1 to 6 carbon atoms or aryl groups having 6 to 8 carbon atoms. Preferably, it is a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 7 carbon atoms (more preferably 6 carbon atoms), and particularly preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. C1 to 6 alkyl groups represent linear, branched, or cyclic alkyl groups. Examples include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, and cyclohexyl groups. Among these, branched or cyclic alkyl groups tend to provide higher heat resistance than linear groups. The number of carbon atoms is preferably 1 to 4 for linear alkyl groups and 6 for cyclic alkyl groups. From the viewpoint of improving heat resistance, isopropyl groups, isobutyl groups, t-butyl groups, and cyclohexyl groups are preferred, and t-butyl groups and cyclohexyl groups are more preferred. Methyl groups are also preferred because they tend to improve flame retardancy.

[0029] Examples of divalent groups represented by formula (2a) include -CH ２ -Ph-CH ２ -ien-CH ２ -Ph-Ph-CH ２ -ien-CH ２ -Ph-CH ２ -Ph-CH ２ -ien-CH ２ -Ph-C(CH ３ ) ２ -Ph-CH ２ -ien-CH ２ -Ph-CH(CH ３ )-Ph-CH ２ -ien-CH ２ -Ph-CH(C) ６ H ５ )-Ph-CH ２ -ien-CH ２ -Ph-Flu-Ph-CH ２ -ien-CH ２ -Np-CH ２ -ien-CH ２ -Np-Np-CH ２ -ien-CH２ -Np-CH ２ -Np-CH ２ -, and -CH ２ -Np-Flu-Np-CH ２ - are examples. These aromatic rings (Ph, Np, and Flu) may further have substituents such as C1-C6 alkyl groups, C1-C6 alkoxy groups, C6-C12 aryl groups, C6-C12 aryloxy groups, C7-C12 aralkyl groups, or C7-C12 aralkyloxy groups. The total number of carbon atoms is 6-50, and more preferably 6-20. Here, Ph is a phenylene group (-C ６ H ４ -) represents a naphthylene group (-C) １０ H ６ -) represents the 9H-fluorene-9,9-diyl group (-C １３ H ８ - represents a biphenylene group, and Ph-Ph represents a biphenylene group. More preferably, an unsubstituted, alkyl group substituted, alkoxy group substituted, or phenyl group substituted -CH ２ -Ph-CH ２ -ien-CH ２ -Ph-Ph-CH ２ -, or -CH ２ -Np-CH ２ - and more preferably, unsubstituted, alkyl-substituted, alkoxy-substituted, or phenyl-substituted -CH ２ -Ph-CH ２ - or -CH ２ -Ph-Ph-CH ２ - is the case.

[0030] Equation (3) above is a generalization of the units expressed in equations (3a) to (3h) below. Similarly, equations (4) and (4') also generalize the R among them. １４ Other Ar ２ and R ４ The structure is a generalized form obtained by omitting one oxygen atom from the monoaryloxy unit or polyaryloxy unit corresponding to formulas (3a) to (3h).

[0031]

[0032] In Formula (3) and Formulas (3a) to (3h), R ３ is synonymous with R in the above Formula (3). R ３ is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. p is an integer from 0 to 4, and q is an integer from 0 to 6.

[0033] In the above Formula (3), Ar １ represents any aromatic ring group of a benzene ring, a naphthalene ring, a diphenylmethane ring or a biphenyl ring as described above. The diphenylmethane ring refers to the structure of Ph-CH ２ -Ph shown in the above Formulas (3f) to (3h). And, similar to the above, these aromatic ring groups may consist only of a benzene ring, a naphthalene ring or a biphenyl ring, or may have a substituent R ６ . Here, the substituent R ６ is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms.

[0034] ​​The above C1-C12 alkyl group may be linear, branched, or cyclic, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, isobutyl group, t-butyl group, n-pentyl group, isopentyl group, neopentyl group, t-pentyl group, methylbutyl group, n-hexyl group, dimethylbutyl group, n-heptyl group, methylhexyl group, trimethylbutyl group, n-octyl group, dimethylpentyl group, ethylpentyl group, isooctyl group, Examples include, but are not limited to, hydrocarbon groups such as ethylhexyl, n-octyl, n-nonyl, n-decyl, and n-dodecyl groups, and cycloalkyl groups having 5 to 12 carbon atoms such as cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, methylcyclohexyl, dimethylcyclohexyl, ethylcyclohexyl, methylcycloheptyl, trimethylcyclohexyl, cyclodecyl, n-undecyl, cyclododecyl, and dicyclopentenyl groups.

[0035] The above carbon-1 to carbon-10 alkoxy groups may be linear, branched, or cyclic. Examples include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentyloxy, n-hexyloxy, n-heptyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, isopropoxy, sec-butoxy, t-butoxy, isopentyloxy, neopentyloxy, t-pentyloxy, isohexyloxy, cyclopentyloxy, cyclohexyloxy, cycloheptyloxy, methylcyclohexyloxy, cyclooctyloxy, dimethylcyclohexyloxy, ethylcyclohexyloxy, trimethylcyclohexyloxy, and cyclodecyloxy groups.

[0036] Examples of the aryl group or aryloxy group having 6 to 11 carbon atoms include a phenyl group, a tolyl group, an ethylphenyl group, a xylyl group, a propylphenyl group, a mesityl group, a naphthyl group, a methylnaphthyl group, a phenoxy group, a tolyloxy group, an ethylphenoxy group, a xylyloxy group, a propylphenoxy group, a mesityloxy group, a naphthyloxy group, a methylnaphthyloxy group, and the like.

[0037] Examples of the aralkyl group or aralkyloxy group having 7 to 12 carbon atoms include a benzyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a phenethyl group, a 1-phenylethyl group, a 2-phenylisopropyl group, a naphthylmethyl group, a benzyloxy group, a methylbenzyloxy group, a dimethylbenzyloxy group, a trimethylbenzyloxy group, a phenethyloxy group, a 1-phenylethyloxy group, a 2-phenylisopropyloxy group, a naphthylmethyloxy group, and the like.

[0038] The above Ar １ is preferably a phenylene group, a naphthylene group, or an aromatic ring group substituted with a methyl group or a 1-phenylethyl group thereon.

[0039] In the above formula (3), R ３ is a divalent group selected from the group consisting of a direct bond, a hydrocarbon group having 1 to 20 carbon atoms, -CO-, -O-, -S-, -SO ２ -, and -C(CF ３ )( ２ ).

[0040] Examples of the hydrocarbon group having 1 to 20 carbon atoms include -CH ２ -, -CH(CH ３ )-, -C ２ H ４ -, -C(CH ３ )( ２-, cyclohexylene group, methylcyclohexylene group, dimethylcyclohexylene group, methylisopropylcyclohexylene group, cyclohexylcyclohexylene group, cyclohexyllidene group, methylcyclohexyllidene group, dimethylcyclohexyllidene group, trimethylcyclohexyllidene group, tetramethylcyclohexyllidene group, ethylcyclohexyllidene group, isopropylcyclohexyllidene group, t-butylcyclohexyllidene group, phenylcyclohexyllidene group, cyclohexylcyclohexyllidene group, (methylcyclohexyl)cyclohexyllidene group, (ethylcyclohexyl)cyclohexyllidene group, (phenyl Examples of divalent groups include cyclohexyl(cyclohexyllidene), cyclododecylene, cyclopentylidene, methylcyclopentylidene, trimethylcyclopentylidene, cyclooctylidene, cyclododecylidene, 9H-fluorene-9,9-diyl, bicyclo[4.4.0]decylidene, bicyclohexanediyl, phenylene, xylylene, phenylmethylene, diphenylmethylene, norbornylene, adamantylene, tetrahydrodicyclopentadienylene, tetrahydrotricyclopentadienylene, norbornane, and tetrahydrotricyclopentadiene.

[0041] Preferred R ３ This is a direct bond, -CH ２ -, -CH(CH ３ )-,-C(CH ３ ) ２ -, -CO-, -O-, -S-, -SO ２ -, trimethylcyclohexylidene group, cyclooctylidene group, cyclododecylidene group, bicyclohexanediyl group, 9H-fluorene-9,9-diyl group, phenylmethylene group.

[0042] The active ester resin of the present invention has monoaryloxy units. Preferably, monoaryloxy units are present at the end of the molecular chain. The monoaryloxy units are represented by formulas (4) and (4') above and are derived from aromatic monohydroxy compounds described later. Here, the content of monoaryloxy units, based on the hydroxyl group, is preferably 10 mol% or more, more preferably 40 mol% or more, even more preferably 90 mol% or more, and preferably 200 mol% or less, relative to the content of the polyaryloxy units mentioned above. That is, the amount of the aromatic monohydroxy compound used, based on the hydroxyl group, is preferably 10 mol% or more, more preferably 40 mol% or more, even more preferably 90 mol% or more, and preferably 200 mol% or less, relative to the total amount of all aromatic polyhydroxy compounds. If the amount of monoaryloxy units (aromatic monohydroxy compounds) is lower than this range, the molecular weight of the resulting active ester resin will be too high, which may result in a high softening point and reduced solvent solubility. If it is higher than this range, the molecular weight of the resulting active ester resin will be too low, which may result in reduced heat resistance of the resulting cured product.

[0043] In equations (4) and (4'), Ar ２ This is Ar in the above formula (2) or formula (3). １ It is an aromatic ring group similar to that of the above, and may have similar substituents, and the preferred substituents are also similar. ４ R ３ Similar to the above, it involves direct bonding, hydrocarbon groups with 1 to 20 carbon atoms, -CO-, -O-, -S-, -SO ２ -, and -C(CF ３ ) ２ It is a divalent group selected from the group consisting of -. １４ is, -CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３ )-, and-C(CF ３ ) ２ It is a divalent group selected from the group consisting of -. k is 0 or 1.

[0044] There are no particular restrictions on the polyarylcarbonyl unit, but the unit represented by formula (5) above is preferred. In formula (5), Ar ３ This is Ar in the above formula (2) or formula (3). １ It is an aromatic ring group similar to that of the above, and may have similar substituents, and the preferred substituents are also similar. ５ R is in equation (3) ３ This is equivalent to the above. k is either 0 or 1.

[0045] The aromatic hydroxy compound, which is an essential raw material for synthesizing the above-mentioned active ester resin, is an aromatic polyvalent hydroxy compound represented by the above formula (1'). However, the aromatic polyvalent hydroxy compound (structural unit) represented by the above formula (1') is contained in an amount of more than 10 mol% and 60 mol% or less, based on the hydroxyl group, relative to the total amount of polyaryloxy units constituting the active ester resin of the present invention. Preferably, it is contained in an amount of 15 mol% to 55 mol%, and more preferably 20 mol% to 50 mol%. If it is lower than this range, the dielectric properties and heat resistance of the obtained active ester resin may deteriorate, and if it is higher than this range, the solvent solubility of the obtained active ester may be poor.

[0046] The structure represented by the above formula (1') is one in which a substituent R is placed on the aromatic ring. １ 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol, which may have substituent R １ As described above, the substituent R represents a hydrocarbon group having 1 to 8 carbon atoms, and is preferably an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, or an allyl group. From the viewpoint of ease of availability and reactivity when cured, substituent R １ The compound is preferably unsubstituted (i=0) or has a phenyl or methyl group.

[0047] When producing the active ester resin of the present invention, it is preferable to use aromatic polyhydric hydroxy compounds other than the aromatic polyhydric hydroxy compound represented by formula (1') above in combination. A preferred range is when, based on the amount used, the other aromatic polyhydric hydroxy compound other than the aromatic polyhydric hydroxy compound represented by formula (1') above is contained in an amount of 40 mol% or more relative to the total amount of aromatic hydroxy compounds used as raw materials, preferably 40 mol% or more and less than 90 mol%, more preferably 45 mol% or more and 85 mol%, and even more preferably 50 mol% or more and 80 mol% or less. If the amount is lower than this range, the crystallinity of the resulting active ester resin may increase, and its solvent solubility may decrease.

[0048] Other aromatic polyhydric hydroxy compounds can be used in combination without particular limitations, but aromatic polyhydric hydroxy compounds constituting the structural units represented by formula (2) and / or formula (3) are preferred.

[0049] Examples of aromatic polyvalent hydroxy compounds constituting the structural unit represented by formula (2) above include novolac resins such as phenol novolac resins (e.g., Showol BRG-555 (manufactured by Aica Kogyo Co., Ltd.)), cresol novolac resins (e.g., DC-5 (manufactured by Nippon Steel Chemical & Material Co., Ltd.)), xylenol novolac resins, biphenol novolac resins, aromatic modified phenol novolac resins, naphthol novolac resins, and other novolac resins, as well as reaction products of phenols and dicyclopentadiene (dicyclopentadiene-type phenol resins), reaction products of naphthols and dicyclopentadiene (dicyclopentadiene-type naphthol resins), and phenols. Examples include aralkyl novolac resins such as reaction products of phenols with terpenes (terpene-type phenolic resins), reaction products of naphthols with terpenes (terpene-type naphthol resins), condensates of phenols and / or naphthols with xylylene glycol (e.g., SN-160, SN-395, SN-485 (all manufactured by Nippon Steel Chemical & Material Co., Ltd.)), condensates of phenols and / or naphthols with isopropenylacetophenone, reaction products of phenols and / or naphthols with divinylbenzene, and condensates of phenols and / or naphthols with biphenyl-based crosslinking agents (e.g., MEH-7851 (manufactured by UBE Corporation)).

[0050] When using aromatic polyvalent hydroxy compounds that constitute the structural unit represented by formula (2) in combination, it is preferable to use those in which the average value of m is in the range of 1 to 2 in order to improve solvent solubility (suppression of gel component generation). Furthermore, gelation can be prevented by appropriately adjusting the amount of aromatic polyvalent hydroxy compounds that constitute the structural unit represented by formula (2) according to the value of m. Here, the aromatic polyvalent hydroxy compounds that constitute the structural unit represented by formula (2) are represented by the following formula (2'), but the aromatic polyvalent hydroxy compounds represented by the following formula (6) are preferred.

[0051] Ar in equation (2') １ Ar １１ And m is Ar in formula (2) above. １ Ar １１ These are synonymous with m, respectively.

[0052] In the formula, R ７ The above R ６ These are synonymous and each independently represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. j is an integer from 0 to 3, and r is synonymous with m in the above formulas (2) and (2') and indicates the number of repetitions, with its average value being a number from 1 to 5.

[0053] Examples of aromatic polyvalent hydroxy compounds (aromatic dihydroxy compounds) that constitute the structural unit represented by formula (3) above include dihydroxybenzenes such as catechol, resorcinol, methylresorcinol, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-t-butylhydroquinone, and di-t-butylhydroquinone, as well as naphthalenediols such as naphthalenediol, methylnaphthalenediol, and methylmethoxynaphthalenediol, and biphenol, dimethylbiphenol, and tetramethylbiphenol. Examples of biphenols include bisphenol A, bisphenol F, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, tetramethylbisphenol Z, dihydroxydiphenyl sulfide, 4,4'-thiobis(3-methyl-6-t-butylphenol), bisphenol fluorene, biscresol fluorene, and 9,9-bis(3,5-dimethyl-4-hydroxyphenyl)-9H-fluorene.

[0054] Furthermore, as described above, when producing the active ester resin of the present invention, an aromatic monohydroxy compound constituting the monoaryloxy unit is essential. While there are no particular restrictions on the aromatic monohydroxy compound that can be used, an aromatic monohydroxy compound represented by the following formula (4-1) is preferred. Alternatively, instead of the aromatic monohydroxy compound represented by the following formula (4-1) (aromatic monophenol compound), an aromatic monoalcohol compound may be used as the aromatic monohydroxy compound. While there are no particular restrictions on the aromatic monoalcohol compound that can be used, an aromatic monoalcohol compound represented by the following formula (4'-1) is preferred.

[0055] In equations (4-1) and (4'-1), Ar ２ , R ４ , R １４ and k are Ar in the above formulas (4) and (4'). ２ , R ４ , R １４ These are synonymous with k, respectively.

[0056] Examples of aromatic monohydroxy compounds (aromatic monophenol compounds) represented by the above formula (4-1) include phenol, o-cresol, m-cresol, p-cresol, 3,5-xylenol, o-phenylphenol, p-phenylphenol, 2-benzylphenol, 4-benzylphenol, 4-(α-cumyl)phenol, octylphenol, α-naphthol, and β-naphthol. Among these, cured products using an active ester resin containing α-naphthol, β-naphthol, o-phenylphenol, p-phenylphenol, and 4-(α-cumyl)phenol as a curing agent have particularly low dielectric loss tangent.

[0057] Examples of aromatic monohydroxy compounds (aromatic monoalcohol compounds) represented by the above formula (4'-1) include benzyl alcohol, tolylmethanol, dimethylbenzyl alcohol, biphenylmethanol, benzylbenzyl alcohol, naphthylmethanol, and the like, with benzyl alcohol, biphenylmethanol, and naphthylmethanol being preferred.

[0058] The active ester resin of the present invention is obtained by reacting the above-mentioned aromatic hydroxy compound, which includes an aromatic polyhydric hydroxy compound and an aromatic monohydroxy compound, with the above-mentioned aromatic carboxylic acid or its acid halide, which includes an aromatic polyhydric carboxylic acid or its acid halide. In this case, the aromatic polyhydric hydroxy compound represented by formula (1') is an essential component. In addition, an aromatic monocarboxylic acid or its acid halide may be used in combination in this reaction. As the halogen of the halogen of the halogen of the aromatic carboxylic acid used, chlorine or bromine is generally used. Examples of halogens of aromatic polyhydric carboxylic acids include halogens of aromatic dicarboxylic acids represented by formula (7) below, and halogens of aromatic tricarboxylic acids such as trimesic acid and trimellitic acid.

[0059] In the formula, Ar ３ , R ５ and k are Ar in formula (5) above. ３ , R ５ These are synonymous with k, respectively.

[0060] Examples of aromatic dicarboxylic acids represented by formula (7) above include phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 4,4-biphenyldicarboxylic acid, 4,4'-methylenebisbenzoic acid, 4,4'-carbonylbisbenzoic acid, and 4,4'-isopropylidenedibenzoic acid. Among these, isophthalic acid chloride and terephthalic acid chloride are preferred as aromatic carboxylic acids or their acid halides from the viewpoint of balancing solvent solubility and heat resistance.

[0061] Examples of halogenated aromatic monocarboxylic acids include halogenated aromatic monocarboxylic acids represented by the following formula (8). When halogenated aromatic monocarboxylic acids are used in combination, a portion of the molecular chain ends become aryloxycarbonyl groups.

[0062] In the formula, Ar ３ , R ５and k are Ar in formula (7) above. ３ , R ５ These are synonymous with k, respectively.

[0063] Examples of aromatic monocarboxylic acids represented by formula (8) include benzoic acid, 1-naphthalenecarboxylic acid, 2-naphthalenecarboxylic acid, and biphenylcarboxylic acid.

[0064] The method for reacting the above-mentioned aromatic hydroxy compound with the above-mentioned aromatic carboxylic acid or its acid halide is, specifically, a method of reacting these components in the presence of an alkaline catalyst. The amount of aromatic carboxylic acid or its acid halide used is preferably 50 to 150 mol%, and more preferably 80 to 120 mol%, based on the amount of carboxyl groups or their acid halogen groups, relative to the amount of hydroxyl groups used in the total aromatic hydroxy compounds (total aromatic polyvalent hydroxy compounds and aromatic monohydroxy compounds) described above. That is, in the active ester resin of the present invention, the aryloxycarbonyl units (polyaryloxycarbonyl units and monoaryloxycarbonyl units) are preferably 50 to 150 mol%, and more preferably 80 to 120 mol%, based on the content of carboxyl groups or their acid halogen groups, relative to the total content of hydroxyl groups constituting the above-mentioned polyaryloxy units and monoaryloxy units.

[0065] The alkaline catalysts that can be used here include inorganic bases such as sodium hydroxide, potassium hydroxide, potassium carbonate, and sodium carbonate, as well as organic bases such as triethylamine, diisopropylethylamine, and pyridine. Among these, sodium hydroxide and potassium hydroxide are preferred due to their superior reactivity and cost-effectiveness.

[0066] The above reaction can be carried out by mixing an aromatic hydroxy compound with an aromatic carboxylic acid or its acid halide in the presence of an organic solvent, and then adding the alkaline catalyst. The amount of alkaline catalyst added is preferably 0.9 to 2.0 moles per mole of phenolic hydroxyl groups of the aromatic hydroxy compound.

[0067] Examples of organic solvents used in the above reaction include toluene, dichloromethane, and chloroform, but toluene is preferred from the viewpoint of cost and environmental impact.

[0068] In the above reaction, a reaction catalyst may be used. Examples of reaction catalysts include quaternary ammonium salts such as tri-n-butylbenzylammonium halide, tetra-n-butylammonium halide, trimethylbenzylammonium halide, and triethylbenzylammonium halide, and quaternary phosphonium salts such as tri-n-butylbenzylphosphonium halide, tetra-n-butylphosphonium halide, trimethylbenzylphosphonium halide, and triethylbenzylphosphonium halide.

[0069] After the reaction is complete, the reaction solution can be neutralized and washed with water to obtain the desired resin.

[0070] The active ester equivalent (g / eq.) of the active ester resin of the present invention is preferably 180 to 500, more preferably 200 to 400, and even more preferably 210 to 350. If it is smaller than this range, the dielectric properties may deteriorate, and if it is larger, the heat resistance and adhesive properties may decrease. Note that the active ester group refers to the aryloxycarbonyl group in the active ester resin.

[0071] The average molecular weight of the active ester resin of the present invention is preferably 1,000 to 4,000, more preferably 1,100 to 3,000, with a weight-average molecular weight (Mw) of 500 to 1,500, more preferably 600 to 1,100. The softening point is preferably 100 to 150°C, more preferably 110 to 140°C.

[0072] By using such an activated ester resin as a curing agent, the epoxy resin composition of the present invention can be obtained.

[0073] The epoxy resin composition of the present invention comprises an epoxy resin and the above-mentioned activated ester resin as essential components. In this embodiment, some or all of the activated ester resin is the activated ester resin of the present invention, and of the total activated ester resin, the activated ester resin of the present invention is preferably at least 30% by mass, more preferably 50% by mass or more, and even more preferably 75% by mass or more. If the amount is less than this, the dielectric properties may deteriorate.

[0074] As the epoxy resin used to obtain the epoxy resin composition of the present invention, any ordinary epoxy resin having two or more epoxy groups in its molecule can be used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, tetramethylbisphenol F type epoxy resin, hydroquinone type epoxy resin, biphenyl type epoxy resin, bisphenol fluorene type epoxy resin, bisphenol S type epoxy resin, bisthioether type epoxy resin, resorcinol type epoxy resin, biphenyl aralkylphenol type epoxy resin, naphthalenediol type epoxy resin, phenol novolac type epoxy resin, styrene-modified phenol novolac type epoxy resin, cresol novolac type epoxy resin, alkyl novolac type epoxy resin, bisphenol no Examples of epoxy resins include, but are not limited to, volac-type epoxy resins, naphthol novolac-type epoxy resins, β-naphthol aralkyl-type epoxy resins, dinaphthol aralkyl-type epoxy resins, α-naphthol aralkyl-type epoxy resins, trisphenylmethane-type epoxy resins, trisphenylmethane-type epoxy resins, dicyclopentadiene-type epoxy resins, alkylene glycol-type epoxy resins, aliphatic cyclic epoxy resins, diaminodiphenylmethane tetraglycidylamine, aminophenol-type epoxy resins, phosphorus-containing epoxy resins, urethane-modified epoxy resins, and oxazolidone ring-containing epoxy resins. Furthermore, these epoxy resins may be used individually or in combination of two or more types.

[0075] From the standpoint of ease of availability, it is preferable to use naphthalenediol-type epoxy resin, phenol novolac-type epoxy resin, aromatic-modified phenol novolac-type epoxy resin, cresol novolac-type epoxy resin, α-naphthol aralkyl-type epoxy resin, dicyclopentadiene-type epoxy resin, phosphorus-containing epoxy resin, or oxazolidone ring-containing epoxy resin.

[0076] In addition to the active ester resin of the present invention, one or more commonly used curing agents such as various phenolic resins, acid anhydrides, amines, hydrazides, and acidic polyesters may be used in combination as needed. When these curing agents are used in combination, the amount of curing agent used is preferably 70% by mass or less, more preferably 50% by mass or less, and even more preferably 25% by mass or less of the total curing agent. If the proportion of curing agent used in combination is too high, the dielectric properties and adhesive properties of the epoxy resin composition may deteriorate.

[0077] In the epoxy resin composition of the present invention, the amount of active hydrogen groups of the curing agent is preferably 0.2 to 1.5 moles, more preferably 0.3 to 1.4 moles, even more preferably 0.5 to 1.3 moles, and particularly preferably 0.8 to 1.2 moles, per mole of epoxy groups of the epoxy resin. If the amount is outside this range, curing may be incomplete and good cured properties may not be obtained. For example, when a phenolic resin-based curing agent or an amine-based curing agent is used in combination, the amount of active hydrogen groups is approximately equimolar to the epoxy groups. When an acid anhydride-based curing agent is used in combination, the amount of acid anhydride groups is preferably 0.5 to 1.2 moles, more preferably 0.6 to 1.0 moles, per mole of epoxy groups. When the active ester resin of the present invention is used alone as a curing agent, the amount used is in the range of 0.5 to 1.5 moles, and preferably in the range of 0.9 to 1.1 moles, per mole of epoxy resin.

[0078] In this invention, an active hydrogen group refers to a functional group having an active hydrogen that reacts with an epoxy group (including functional groups having latent active hydrogen that generates active hydrogen by hydrolysis, etc., and functional groups that exhibit equivalent curing effects). Specifically, examples include acid anhydride groups, carboxyl groups, amino groups, and phenolic hydroxyl groups. Regarding active hydrogen groups, 1 mole of a carboxyl group or phenolic hydroxyl group is 1 mole of an amino group (NH ２ ) is calculated as 2 moles. Furthermore, if the active hydrogen group is not clear, the active hydrogen equivalent can be determined by measurement. For example, by reacting a monoepoxy resin such as phenylglycidyl ether with a known epoxy equivalent with a curing agent whose active hydrogen equivalent is unknown, and measuring the amount of monoepoxy resin consumed, the active hydrogen equivalent of the curing agent used can be determined.

[0079] Specific examples of phenolic resin curing agents that can be used in combination with the epoxy resin composition of the present invention include bisphenols such as bisphenol A, bisphenol F, bisphenol C, bisphenol K, bisphenol Z, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol S, tetramethylbisphenol Z, dihydroxydiphenyl sulfide, and 4,4'-thiobis(3-methyl-6-t-butylphenol); dihydroxybenzenes such as catechol, resorcinol, methylresorcinol, hydroquinone, monomethylhydroquinone, dimethylhydroquinone, trimethylhydroquinone, mono-t-butylhydroquinone, and di-t-butylhydroquinone; and dihydroxynaphthalene (naphthalenediol), dihydroxymethylnaphthalene (methylnaphthalenediol), dihydroxydimethylnaphthalene (dimethylnaphthalenediol), and dihydroxymethylmethoxynaphthalene (methylmethoxynaphthalenediol) Examples include hydroxynaphthalenes such as trihydroxynaphthalene, phosphorus-containing phenol curing agents such as LC-950PM60 (manufactured by Shin-AT&C), phenol novolac resins, cresol novolac resins, aromatically modified phenol novolac resins, bisphenol A novolac resins, trishydroxyphenylmethane type novolac resins such as Resitopp TPM-100 (manufactured by Gun-ei Chemical Industry Co., Ltd.), naphthol novolac resins, phenols, naphthols, and / or condensates of bisphenols and aldehydes, phenols, naphthols, and / or condensates of bisphenols and xylylene glycol, phenols and / or naphthols and isopropenylacetophenone, phenols, naphthols, and / or reaction products of bisphenols and dicyclopentadiene, phenols, naphthols, and / or condensates of bisphenols and biphenyl crosslinking agents, and other phenol compounds known as novolac phenol resins. From the standpoint of availability, phenol novolac resins, dicyclopentadiene-type phenolic resins, trishydroxyphenylmethane-type novolac resins, aromatically modified phenol novolac resins, etc., are preferred.

[0080] In the case of novolacphenol resins, examples of phenols include phenol, cresol, xylenol, butylphenol, amylphenol, nonylphenol, butylmethylphenol, trimethylphenol, and phenylphenol. Examples of naphthols include 1-naphthol and 2-naphthol. Other examples include the bisphenols mentioned above. Examples of aldehydes include formaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, valeraldehyde, caproaldehyde, benzaldehyde, chloraldehyde, bromaldehyde, glyoxal, malonaldehyde, succinaldehyde, glutaraldehyde, adipinealdehyde, pimelinaldehyde, sebacinaldehyde, acrolein, crotonaldehyde, salicylaldehyde, phthalaldehyde, and hydroxybenzaldehyde. Examples of biphenyl-based crosslinking agents include bis(methylol)biphenyl, bis(methoxymethyl)biphenyl, bis(ethoxymethyl)biphenyl, and bis(chloromethyl)biphenyl.

[0081] Examples of acid anhydride-based curing agents include methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, phthalic anhydride, trimellitic anhydride, and methylnadic acid.

[0082] Examples of amine-based curing agents include amine compounds such as diethylenetriamine, triethylenetetramine, metaxylenediamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiphenyl ether, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, dicyandiamide, and polyamidoamine, which are condensates of acids such as dimer acid and polyamines.

[0083] Other curing agents include, specifically, phosphine compounds such as triphenylphosphine, phosphonium salts such as tetraphenylphosphonium bromide, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-undecylimidazole, and 1-cyanoethyl-2-methylimidazole, imidazole salts which are salts of imidazoles with trimellitic acid, isocyanuric acid, or boron, quaternary ammonium salts such as trimethylammonium chloride, diazabicyclo compounds, salts of diazabicyclo compounds with phenols or phenol novolac resins, complex compounds of boron trifluoride with amines or ether compounds, aromatic phosphoniums, or iodonium salts.

[0084] The epoxy resin composition of the present invention may use known and conventional epoxy resin curing accelerators as needed. Examples of usable curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, and 2-undecylimidazole; tertiary amines such as 4-dimethylaminopyridine, 2-(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)undecene-7; and 3-phenyl-1,1-dimethylurea and 3-(4-methylphenyl)-1,1 Examples include urea compounds such as dimethylurea, chlorophenylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea; phosphines such as triphenylphosphine, tributylphosphine, tricyclohexylphosphine, triphenylphosphinetriphenylborane; quaternary phosphonium salts such as TBP-DA, TBP-3PC, TBP-3S, and TPP-phthalic acid manufactured by Hokko Chemical Industry Co., Ltd.; and metal compounds such as tin octylate. These curing accelerators may be used alone or in combination of two or more types. Among these, 4-dimethylaminopyridine and imidazoles are preferred.

[0085] When using a curing accelerator, the amount used can be appropriately selected depending on the purpose of use, but 0.01 to 15 parts by mass per 100 parts by mass of epoxy resin component in the epoxy resin composition is used as needed, preferably 0.02 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, and even more preferably 0.1 to 5 parts by mass. By using a curing accelerator, the curing temperature can be lowered and the curing time can be shortened.

[0086] The epoxy resin composition may be used with an organic solvent or reactive diluent to adjust its viscosity.

[0087] Examples of organic solvents include amides such as N,N-dimethylformamide and N,N-dimethylacetamide; ethers such as ethylene glycol monomethyl ether, dimethoxydiethylene glycol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, and triethylene glycol dimethyl ether; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; alcohols such as methanol, ethanol, 1-methoxy-2-propanol, 2-ethyl-1-hexanol, benzyl alcohol, ethylene glycol, propylene glycol, butyl diglycol, and pine oil; and vinegar. Examples of acetate esters such as butyl acid, methoxybutyl acetate, methyl cellosolve acetate, cellosolve acetate, ethyl diglycol acetate, propylene glycol monomethyl ether acetate, carbitol acetate, and benzyl alcohol acetate; benzoic acid esters such as methyl benzoate and ethyl benzoate; cellosolves such as methyl cellosolve, cellosolve, and butyl cellosolve; carbitols such as methyl carbitol, carbitol, and butyl carbitol; aromatic hydrocarbons such as benzene, toluene, and xylene; and dimethyl sulfoxide, acetonitrile, and N-methylpyrrolidone, but are not limited to these.

[0088] Examples of reactive diluents include, but are not limited to, monofunctional glycidyl ethers such as allyl glycidyl ether, butyl glycidyl ether, 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, and tolyl glycidyl ether; difunctional glycidyl ethers such as resorcinol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, cyclohexanedimethanol diglycidyl ether, and propylene glycol diglycidyl ether; polyfunctional glycidyl ethers such as glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolethane polyglycidyl ether, and pentaerythritol polyglycidyl ether; glycidyl esters such as neodecanoic acid glycidyl ester; and glycidylamines such as phenyl diglycidylamine and tolyl diglycidylamine.

[0089] These organic solvents or reactive diluents are preferably used individually or in mixtures of several types, at a non-volatile content of 90% by mass or less, and the appropriate type and amount are selected as appropriate depending on the application. For example, in printed circuit board applications, polar solvents with a boiling point of 160°C or less, such as methyl ethyl ketone, acetone, and 1-methoxy-2-propanol, are preferred, and the amount used is preferably 40 to 80% by mass in terms of non-volatile content. In adhesive film applications, for example, ketones, acetate esters, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferred, and the amount used is preferably 30 to 60% by mass in terms of non-volatile content.

[0090] The epoxy resin composition may contain other thermosetting resins or thermoplastic resins to the extent that it does not impair the properties. Examples include, but are not limited to, phenolic resins, acrylic resins, petroleum resins, indene resins, coumarone indene resins, phenoxy resins, polyurethane resins, polyester resins, polyamide resins, polyimide resins, polyamide-imide resins, polyetherimide resins, polyphenylene ether resins, modified polyphenylene ether resins, polyethersulfone resins, polysulfone resins, polyetheretherketone resins, polyphenylene sulfide resins, and polyvinyl formal resins.

[0091] Various known flame retardants can be used in the epoxy resin composition to improve the flame retardancy of the resulting cured product. Examples of usable flame retardants include halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organometallic salt-based flame retardants. From an environmental standpoint, halogen-free flame retardants are preferred, and phosphorus-based flame retardants are particularly preferred. These flame retardants may be used individually or in combination of two or more types.

[0092] Phosphorus-based flame retardants can be either inorganic phosphorus compounds or organophosphorus compounds. Examples of inorganic phosphorus compounds include ammonium phosphates such as red phosphorus, monoammonium phosphate, diammonium phosphate, triammonium phosphate, and polyammonium phosphate, as well as inorganic nitrogen-containing phosphorus compounds such as phosphate amides. Examples of organophosphorus compounds include aliphatic phosphate esters, phosphate ester compounds, condensed phosphate esters such as PX-200 (manufactured by Daihachi Chemical Industry Co., Ltd.), phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phospholane compounds, and organic nitrogen-containing phosphorus compounds, as well as metal salts of phosphinic acid, cyclic organophosphorus compounds such as 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10-(2,5-dihydrooxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and 10-(2,7-dihydrooxynaphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, and derivatives obtained by reacting these with compounds such as epoxy resins and phenolic resins, such as phosphorus-containing epoxy resins and phosphorus-containing curing agents.

[0093] The amount of flame retardant added is appropriately selected depending on the type of phosphorus-based flame retardant, the components of the epoxy resin composition, and the desired degree of flame retardancy. For example, the phosphorus content in the organic components (excluding organic solvents) of the epoxy resin composition is preferably 0.2 to 4% by mass, more preferably 0.4 to 3.5% by mass, and even more preferably 0.6 to 3% by mass. If the phosphorus content is too low, it may be difficult to ensure flame retardancy, and if it is too high, it may adversely affect the heat resistance. When using a phosphorus-based flame retardant, a flame retardant aid such as magnesium hydroxide may also be used in combination.

[0094] Fillers may be used in epoxy resin compositions as needed. Specifically, examples include fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, boehmite, magnesium hydroxide, talc, mica, calcium carbonate, calcium silicate, calcium hydroxide, magnesium carbonate, barium carbonate, barium sulfate, boron nitride, carbon, carbon fiber, glass fiber, alumina fiber, silica-alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aramid fiber, ceramic fiber, fine particle rubber, thermoplastic elastomer, and pigments. Generally, the reason for using fillers is to improve impact resistance. In addition, when metal hydroxides such as aluminum hydroxide, boehmite, and magnesium hydroxide are used, they act as flame retardant aids, improving flame retardancy. The amount of these fillers added to the epoxy resin composition is preferably 1 to 150% by mass, and more preferably 10 to 70% by mass. If the amount added is too high, the adhesion required for laminate applications may decrease, and the cured product may become brittle, resulting in insufficient mechanical properties. Furthermore, if the amount of filler used is too small, the intended effects of the filler, such as improved impact resistance of the cured product, may not be realized.

[0095] The epoxy resin composition may further contain radionuclide additives such as silane coupling agents, antioxidants, mold release agents, defoaming agents, emulsifiers, thixotropy-inducing agents, smoothing agents, flame retardants, and pigments, as needed. The amount of these additives added is preferably in the range of 0.01 to 20% by mass relative to the epoxy resin composition.

[0096] The epoxy resin composition of the present invention is obtained by uniformly mixing the above components. An epoxy resin composition containing an active ester resin, an epoxy resin, and various other materials as needed can be cured in the same manner as known epoxy resin compositions to obtain an epoxy resin cured product. Examples of cured products include molded cured products such as laminates, cast products, molded products, adhesive layers, insulating layers, and films. Methods for obtaining a cured product can be the same as those for known epoxy resin compositions, and methods such as casting, injection, potting, dipping, drip coating, transfer molding, compression molding, and lamination of resin sheets, resin-coated copper foil, prepregs, etc., followed by heating, pressing, and curing to form a laminate are preferably used.

[0097] The curing method for epoxy resin compositions varies depending on the components and their proportions in the epoxy resin composition, but typically the curing temperature is 80 to 300°C and the curing time is 10 to 360 minutes. This heating is preferably carried out in two stages: primary heating at 80 to 180°C for 10 to 90 minutes and secondary heating at 120 to 200°C for 60 to 150 minutes. Furthermore, in formulations where the glass transition temperature (Tg) exceeds the secondary heating temperature, it is preferable to perform a tertiary heating at 150 to 280°C for 60 to 120 minutes. Such secondary and tertiary heating can reduce curing defects. When producing resin semi-cured products such as resin sheets, resin-coated copper foil, and prepregs, the curing reaction of the epoxy resin composition is usually advanced by heating or other means to the extent that the shape can be maintained. If the epoxy resin composition contains a solvent, most of the solvent is usually removed by methods such as heating, reduced pressure, and air drying, but it is also acceptable to leave 5% by mass or less of solvent in the resin semi-cured product. Furthermore, the uncured or partially cured sheets of the epoxy resin composition of the present invention can be suitably used, for example, as build-up films, bonding sheets, coverlay sheets, bump sheets for flip-chip bonders, or as insulating or adhesive layers for substrates.

[0098] Epoxy resin compositions can be used in a variety of applications, including circuit board materials, encapsulating materials, casting materials, conductive pastes, adhesives, and insulating materials. They are particularly useful in the electrical and electronic fields as insulating casting materials, laminating materials, and encapsulating materials. Examples of applications include, but are not limited to, printed circuit boards, flexible circuit boards, laminates for electrical and electronic circuits such as capacitors, resin-coated metal foils, adhesives such as film adhesives and liquid adhesives, semiconductor encapsulating materials, underfill materials, interchip fill materials for 3D-LSIs, insulating materials for circuit boards, insulating sheets, prepregs, heat dissipation substrates, and resist inks.

[0099] Among these various applications, in applications such as printed circuit board materials, insulating materials for circuit boards, and build-up adhesive films, it can be used as an insulating material for so-called electronic component-embedded boards, in which passive components such as capacitors and active components such as IC chips are embedded within the board. Among these, it is preferable to use it as a material for circuit boards (laminated boards) such as printed circuit board materials, epoxy resin compositions for flexible wiring boards, and interlayer insulating materials for build-up boards, as well as semiconductor encapsulation materials, due to its properties of high flame retardancy, high heat resistance, and solvent solubility.

[0100] When epoxy resin compositions are formed into plates such as laminates, fibrous fillers are preferred in terms of dimensional stability and bending strength, with glass cloth, glass mat, and glass roving cloth being more preferred.

[0101] By impregnating a fibrous reinforcing substrate with an epoxy resin composition, prepregs used in printed circuit boards and the like can be created. Examples of fibrous reinforcing substrates include, but are not limited to, inorganic fibers such as glass, or woven or nonwoven fabrics of organic fibers such as polyester resin, polyamine resin, polyacrylic resin, polyimide resin, and aromatic polyamide resin.

[0102] The method for producing a prepreg from an epoxy resin composition is not particularly limited. For example, the epoxy resin composition may be prepared as a resin varnish by adjusting the viscosity of the epoxy resin composition with an organic solvent, the resin varnish may be impregnated into the fibrous reinforcing substrate, and then heated and dried to partially cure (B-stage) the resin component. The heating temperature is preferably 50 to 200°C, and more preferably 100 to 170°C, depending on the type of organic solvent used. The heating time is adjusted depending on the type of organic solvent used and the curability of the prepreg, and is preferably 1 to 40 minutes, and more preferably 3 to 20 minutes. In this case, the mass ratio of the epoxy resin composition to the reinforcing substrate is not particularly limited, but it is usually preferable to adjust it so that the resin content in the prepreg is 20 to 80% by mass.

[0103] The epoxy resin composition of the present invention can be used by molding it into a sheet or film. In this case, it is possible to form a sheet or film using conventionally known methods. The method for producing the resin sheet is not particularly limited, but examples include: (a) an extrusion molding method in which the epoxy resin composition is kneaded in an extruder and then extruded and molded into a sheet using a T-die or circular die; (b) a casting molding method in which the epoxy resin composition is dissolved or dispersed in a solvent such as an organic solvent and then cast to form a sheet; and (c) other conventionally known sheet molding methods. The film thickness (μm) of the resin sheet is not particularly limited, but is preferably 10 to 300, more preferably 25 to 200, and even more preferably 40 to 180. When used in the build-up method, the film thickness of the resin sheet is particularly preferably 40 to 90 μm. If the film thickness is 10 μm or more, insulating properties can be obtained, and if it is 300 μm or less, the distance between electrodes in the circuit will not become unnecessarily long. The solvent content of the resin sheet is not particularly limited, but it is preferably 0.01 to 5% by mass relative to the entire epoxy resin composition. If the solvent content in the film is 0.01% by mass or more relative to the entire epoxy resin composition, adhesion and bonding properties are easily obtained when laminating to a circuit board, and if it is 5% by mass or less, flatness after heat curing is easily obtained.

[0104] A more specific method for manufacturing the adhesive sheet involves applying a varnish-like epoxy resin composition containing the above-mentioned organic solvent onto a support base film that does not dissolve in the organic solvent, using a coating machine such as a reverse roll coater, comma coater, or die coater, and then heating and drying it to B-stage the resin component. If necessary, another support base film can be placed on the coated surface (adhesive layer) as a protective film and dried to obtain an adhesive sheet having release layers on both sides of the adhesive layer.

[0105] Examples of support base films include metal foils such as copper foil, polyethylene films, polyolefin films such as polypropylene films, polyester films such as polyethylene terephthalate films, polycarbonate films, silicone films, and polyimide films. Among these, polyethylene terephthalate film is preferred because it is free of defects, has excellent dimensional accuracy, and is cost-effective. Metal foils, especially copper foil, are also preferred because they facilitate the multilayering of laminates. The thickness of the support base film is not particularly limited, but it is preferably 10 to 150 μm, and more preferably 25 to 50 μm, as it provides sufficient strength as a support and is less prone to lamination defects.

[0106] The thickness of the protective film is not particularly limited, but is generally 5 to 50 μm. It is preferable to pre-treat the surface with a release agent to facilitate the removal of the molded adhesive sheet. The thickness of the resin varnish applied after drying is preferably 5 to 200 μm, and more preferably 5 to 100 μm.

[0107] The heating temperature is preferably 50 to 200°C, and more preferably 100 to 170°C, depending on the type of organic solvent used. The heating time is adjusted according to the type of organic solvent used and the curability of the prepreg, and is preferably 1 to 40 minutes, and more preferably 3 to 20 minutes.

[0108] The resin sheet obtained in this manner is usually an insulating adhesive sheet, but a conductive adhesive sheet can also be obtained by mixing a conductive metal or metal-coated fine particles into the epoxy resin composition. The support base film is peeled off after lamination to the circuit board or after heat curing to form an insulating layer. Peeling off the support base film after heat curing the adhesive sheet prevents the adhesion of dust and other contaminants during the curing process. Here, the insulating adhesive sheet is also an insulating sheet.

[0109] Furthermore, when the resin sheet of the present invention is used as a bonding sheet, for example, two substrates can be bonded together with the resin sheet. Each of the two substrates is, for example, a laminate or a printed circuit board. Specifically, for example, the resin sheet is produced by forming an epoxy resin composition into a sheet shape on a support film by a coating method or the like, and then drying or semi-curing it by heating. This resin sheet is placed on a substrate (first substrate), the support film is peeled off the resin sheet, and another substrate (second substrate) is placed on top. That is, the first substrate, the resin sheet, and the second substrate are laminated in that order. Subsequently, by heating and curing, the first substrate and the second substrate are bonded together via the cured resin composition.

[0110] The present invention describes resin-coated metal foil obtained using the epoxy resin composition. As the metal foil, single, alloy, or composite metal foils of copper, aluminum, brass, nickel, etc. can be used. It is preferable to use metal foil with a thickness of 9 to 70 μm. The method for producing resin-coated metal foil from the epoxy resin composition and metal foil of the present invention is not particularly limited, and for example, it can be obtained by applying a resin varnish, obtained by adjusting the viscosity of the epoxy resin composition with a solvent, to one surface of the metal foil using a roll coater or the like, and then heating and drying to semi-cure (B-stage) the resin component and form a resin layer. For example, the resin component can be semi-cured by heating and drying at 100 to 200°C for 1 to 40 minutes. Here, it is preferable to form the resin portion of the resin-coated metal foil with a thickness of 5 to 110 μm.

[0111] Furthermore, while the curing method for laminates used in the manufacture of printed circuit boards can generally be used to cure prepregs and insulating adhesive sheets, it is not limited to this method. For example, when forming a laminate using prepregs, one or more prepregs are stacked, metal foil is placed on one or both sides to form a laminate, and this laminate is heated under pressure to cure and integrate the prepregs, thereby obtaining a laminate. Here, as the metal foil, single, alloy, or composite metal foils of copper, aluminum, brass, nickel, etc. can be used.

[0112] The conditions for heating and pressurizing the laminate can be adjusted as appropriate to the conditions under which the epoxy resin composition hardens. However, if the pressurizing pressure is too low, air bubbles may remain inside the resulting laminate, which may reduce its electrical properties. Therefore, it is preferable to pressurize under conditions that satisfy moldability. The heating temperature is preferably 160 to 250°C, and more preferably 170 to 220°C. The pressurizing pressure is preferably 0.5 to 10 MPa, and more preferably 1 to 5 MPa. The heating and pressurizing time is preferably 10 minutes to 4 hours, and more preferably 40 minutes to 3 hours. If the heating temperature is too low, the hardening reaction may not proceed sufficiently, and if it is too high, thermal decomposition of the hardened material may occur. If the pressurizing pressure is too low, air bubbles may remain inside the resulting laminate, which may reduce its electrical properties. If it is too high, the resin may flow before hardening, and a laminate of the desired thickness may not be obtained. Also, if the heating and pressurizing time is too short, the hardening reaction may not proceed sufficiently, and if it is too long, thermal decomposition of the hardened material may occur.

[0113] Furthermore, a multilayer board can be created using the single-layer laminate obtained in this way as an inner layer material. In this case, first, circuits are formed on the laminate using an additive method or a subtractive method, and the formed circuit surface is treated with an acid solution to blacken it and obtain the inner layer material. An insulating layer is formed on one or both sides of the circuit-formed surface of this inner layer material using prepreg, resin sheet, insulating adhesive sheet, or resin-coated metal foil, and a conductive layer is formed on the surface of the insulating layer to form a multilayer board.

[0114] Furthermore, when forming an insulating layer using prepreg, one or more layers of prepreg are laminated and placed on the circuit-forming surface of the inner layer material, and metal foil is placed on the outside to form a laminate. This laminate is then heated and pressurized to form a single unit, thereby forming the cured prepreg as an insulating layer and the outer metal foil as a conductive layer. Here, the same type of metal foil used for the laminate used as the inner layer material can be used. The heating and pressing molding can be carried out under the same conditions as for molding the inner layer material. On the surface of the multilayer laminate thus formed, via holes and circuits can be formed using additive or subtractive methods to form a printed circuit board. Furthermore, by repeating the above method using this printed circuit board as the inner layer material, even more multilayer boards can be formed.

[0115] For example, when forming an insulating layer with an insulating adhesive sheet, the insulating adhesive sheet is placed on the circuit-forming surfaces of multiple inner layer materials to form a laminate. Alternatively, the insulating adhesive sheet is placed between the circuit-forming surface of the inner layer material and the metal foil to form a laminate. This laminate is then heated and pressurized to form a single unit, thereby forming a hardened insulating adhesive sheet as an insulating layer and creating a multilayer structure of the inner layer material. Alternatively, the hardened insulating adhesive sheet is formed as an insulating layer between the inner layer material and the metal foil which is the conductive layer. Here, the metal foil can be the same as the one used for the laminate used as the inner layer material. Furthermore, the heating and pressing molding can be carried out under the same conditions as the molding of the inner layer material.

[0116] Furthermore, when forming an insulating layer by applying an epoxy resin composition to a laminate, the epoxy resin composition is applied to a thickness of preferably 5 to 100 μm, and then heated and dried at 100 to 200°C, preferably 150 to 200°C, for 1 to 120 minutes, preferably 30 to 90 minutes, to form a sheet. This is generally formed by a method called the casting method. The thickness after drying is preferably 5 to 150 μm, preferably 5 to 80 μm. The viscosity of the epoxy resin composition is preferably 10 to 40,000 mPa·s at 25°C, and more preferably 200 to 30,000 mPa·s, in order to obtain a sufficient film thickness and to prevent uneven coating and streaks. On the surface of the multilayer laminate formed in this way, via holes and circuits can be formed using the additive method or the subtractive method to form a printed circuit board. Furthermore, by repeating the above method using this printed circuit board as an inner layer material, an even more multilayer laminate can be formed.

[0117] The epoxy resin composition of the present invention can be used to obtain encapsulants for tape-shaped semiconductor chips, potting-type liquid encapsulants, underfills, and interlayer insulating films for semiconductors, and is suitable for these applications. For example, in semiconductor package molding, the epoxy resin composition can be molded using a casting mold or a transfer molding machine, injection molding machine, etc., and then heated at 50 to 200°C for 2 to 10 hours to obtain a molded product.

[0118] To prepare an epoxy resin composition for use as a semiconductor encapsulating material, one method involves pre-mixing the epoxy resin composition with additives such as inorganic fillers, coupling agents, and mold release agents, which are added as needed, and then thoroughly melt-mixing the mixture until it becomes uniform using an extruder, kneader, rolls, etc. In this case, silica is usually used as the inorganic filler, and it is preferable to add the inorganic filler to the epoxy resin composition in a proportion of 70 to 95% by mass.

[0119] When the epoxy resin composition obtained in this way is used as a tape-type encapsulant, it can be heated to produce a semi-cured sheet, which is then made into an encapsulant tape. This encapsulant tape is then placed on a semiconductor chip, heated to 100-150°C to soften and mold it, and then completely cured at 170-250°C. When used as a potting-type liquid encapsulant, the obtained epoxy resin composition can be dissolved in a solvent as needed, applied to a semiconductor chip or electronic component, and cured directly.

[0120] Furthermore, the epoxy resin composition of the present invention can also be used as a resist ink. In this case, a vinyl monomer having an ethylenically unsaturated double bond and a cationic polymerization catalyst as a curing agent are added to the epoxy resin composition, and then a pigment, talc, and filler are added to make a resist ink composition. This composition is then applied to a printed circuit board by screen printing, and finally cured into a resist ink. The curing temperature in this case is preferably in the range of 20 to 250°C.

[0121] We prepared an epoxy resin composition and evaluated the laminate and cured product by heat curing. As a result, we were able to provide an epoxy resin composition that exhibits excellent low dielectric properties in the cured product, and furthermore, has excellent copper foil peel strength and interlayer adhesion strength for printed circuit board applications.

[0122] The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these. Unless otherwise specified, "parts" refers to parts by mass, "%" refers to mass percent, and "ppm" refers to mass ppm. The measurements were performed by the following methods.

[0123] (1) Hydroxyl group equivalent: Measurement was performed in accordance with JIS K0070 standard, and the unit is expressed as "g / eq.". Unless otherwise specified, the hydroxyl group equivalent of aromatic polyvalent hydroxy compounds refers to the phenolic hydroxyl group equivalent.

[0124] (2) Softening point: Measured in accordance with JIS K7234 standard, ring-sphere method. Specifically, an automatic softening point device (ASP-MG4, manufactured by Maytec Co., Ltd.) was used.

[0125] (3) Total chlorine: Measured in accordance with JIS K7243-3 standard. Specifically, 1.0 g of the sample was dissolved in 25 mL of butyl carbitol, then 25 mL of 1 N-KOH propylene glycol solution was added and heated under reflux for 10 minutes, then cooled to room temperature, and 100 mL of 80% aqueous acetone was added to measure 0.002 N-AgNO ３ The measurement was performed by potentiometric titration using an aqueous solution.

[0126] (4) Relative permittivity and dielectric loss tangent: The relative permittivity (ε1) and dielectric loss tangent (Tanδ1) of the resin sample (test piece) at a frequency of 10 GHz were measured using a vector network analyzer (Keysight Technologies, product name: Vector Network Analyzer E8363C) and an SPDR resonator.

[0127] (5) Glass transition temperature (Tg): In accordance with IPC-TM-650 2.4.25. c, the temperature was expressed as DSC-Tgm (the temperature midway between the tangent lines of the displacement curve between the glass state and the rubber state) when measured using a differential scanning calorimetry system (Hitachi High-Tech Science Co., Ltd., EXSTAR6000 DSC6200) under a heating condition of 20°C / min.

[0128] (6) GPC (Gel Permeation Chromatography) Measurement: Main unit (Tosoh Corporation, HLC-8220GPC) and column (Tosoh Corporation, TSKgelG4000H ＸＬ ,TSKgelG3000H ＸＬ ,TSKgelG2000H ＸＬ A column with two columns in series was used, and the column temperature was set to 40°C. Tetrahydrofuran (THF) was used as the eluent at a flow rate of 1 mL / min, and a differential refractive index detector was used. For the measurement sample, 0.1 g of the sample was dissolved in 10 mL of THF, filtered through a microfilter, and 50 μL of the result was used. Mw and Mn were determined by conversion from a calibration curve obtained from standard polystyrene (PStQuick Kit-H, manufactured by Tosoh Corporation). Data processing was performed using Tosoh Corporation's GPC-8020 Model II version 6.00.

[0129] (7) IR: Fourier transform infrared spectrophotometer (Perkin Elmer Precisly, Spectrum One FT-IR Spectrometer 1760X) with diamond ATR, wavenumber 650-4000 cm －１ The absorbance was measured.

[0130] The abbreviations used in the examples and comparative examples are as follows:

[0131] [Aromatic Hydroxy Compounds] PH1: 4,4'-(3,3,5-trimethylcyclohexane-1,1-diyl)diphenol PH2: Aromatic hydroxy compound obtained in Synthesis Example 1 PH3: Aromatic hydroxy compound obtained in Synthesis Example 2 PH4: 1-Naphthol PH5: Biphenylaralkyl type aromatic hydroxy resin (manufactured by Meiwa Chemicals, Inc., MEH-7851, phenolic hydroxyl group equivalent 213)

[0132] [Aromatic carboxylic acid halides] B1: Isophthalic acid chloride B2: Terephthalic acid chloride

[0133] [Epoxy Resin] E1: Phenol-dicyclopentadiene type epoxy resin (manufactured by Kokuto Chemical Co., Ltd., KDCP-130, epoxy equivalent 254, softening point 72°C)

[0134] [Curing agent] A1: Active ester resin obtained in Example 1 A2: Active ester resin obtained in Example 2 A3: Active ester resin obtained in Example 3 A4: Active ester resin obtained in Example 4 A5: Active ester resin obtained in Example 5 A6: Active ester resin obtained in Example 6 A7: Active ester resin obtained in Example 7 A8: Active ester resin obtained in Comparative Example 1 A9: Active ester resin obtained in Comparative Example 2 A10: Active ester resin obtained in Comparative Example 3 A11: Active ester resin obtained in Comparative Example 4

[0135] [Curing accelerator] C1: 4-dimethylaminopyridine (manufactured by Kishida Chemical Co., Ltd.)

[0136] Synthesis Example 1 A reaction apparatus consisting of a glass separable flask equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser is used to synthesize 2,6-xylenol (structural formula below). 500 copies, 47% BF３ 7.3 parts of the ether complex were charged and heated to 100°C while stirring. While maintaining the same temperature, dicyclopentadiene (structural formula below) was added. 67.6 parts (0.12 molars relative to 2,6-xylenol) were added dropwise over 1 hour. The mixture was then reacted at 115-125°C for 4 hours, and 11 parts of calcium hydroxide were added. Further, 19 parts of a 10% oxalic acid aqueous solution were added. Afterward, the mixture was heated to 160°C to dehydrate it, and then heated to 200°C under reduced pressure of 5 mmHg to evaporate and remove any unreacted raw materials. 1320 parts of methyl isobutyl ketone (MIBK) were added to dissolve the product, and 400 parts of 80°C warm water were added for washing, separating and removing the lower layer of water. Then, the mixture was heated to 160°C under reduced pressure of 5 mmHg to evaporate and remove the MIBK, yielding 164 parts of a reddish-brown aromatic hydroxy compound (PH2). The hydroxyl equivalent of the obtained aromatic hydroxy compound (PH2) was 195, and its softening point was 73°C. The aromatic hydroxy compound is represented by formula (6), where R ７ The group was a methyl group, j was 2, r was 1.1, and the Mw and Mn values ​​in the GPC were 470 and 440, respectively.

[0137] Synthesis Example 2: In the same reaction apparatus as in Synthesis Example 1, 400 parts of phenol and 47% BF ３ 7.5 parts of the ether complex were charged and heated to 70°C with stirring. While maintaining the same temperature, 70.2 parts of dicyclopentadiene were added dropwise over 2 hours. The reaction was further carried out at 125-135°C for 4 hours, and 11.7 parts of calcium hydroxide were added. Then 20 parts of a 10% oxalic acid aqueous solution were added. After that, the mixture was heated to 160°C to dehydrate it, and then heated to 200°C under reduced pressure of 5 mmHg to evaporate and remove any unreacted starting materials. 1100 parts of MIBK were added to dissolve the product, and 330 parts of 80°C warm water were added for washing, and the lower layer of water was separated and removed. Then, the MIBK was evaporated and removed under reduced pressure of 5 mmHg to 160°C to obtain 158 parts of a reddish-brown aromatic hydroxy compound (pH 3). The hydroxyl equivalent was 177, and the softening point was 92°C. The aromatic hydroxy compound represented by formula (6) had j = 0, r = 1.3, GPC Mw = 460, and Mn = 390.

[0138] Example 1 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 125.6 parts of pH2 from Synthesis Example 1 (100 mol% relative to the hydroxyl groups of pH1), 185.8 parts of 1-naphthol (pH4) (100 mol% relative to the total hydroxyl groups of pH1 and pH2), 24.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH2, and pH4), 261.6 parts of B1 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH2, and pH4), and 1650 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 515.5 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 570 parts of activated ester resin (A1). The activated ester equivalent calculated from the amount of raw materials charged was 226, the phenolic hydroxyl group equivalent was 26500, the total chlorine content was 100 ppm, the softening point was 127°C, the Mw in GPC was 1400, and the Mn was 750. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 50 mol%. The GPC chart of the obtained active ester resin (A1) is shown in Figure 1, and the FT-IR chart is shown in Figure 2.

[0139] Example 2 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 251.3 parts of pH2 from Synthesis Example 1 (200 mol% relative to the hydroxyl groups of pH1), 278.7 parts of 1-naphthol (pH4) (100 mol% relative to the total hydroxyl groups of pH1 and pH2), 37.4 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH2, and pH4), 392.4 parts of B1 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH2, and pH4), and 2520 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 773.2 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 868 parts of activated ester resin (A2). The activated ester equivalent calculated from the amount of raw materials charged was 229, the phenolic hydroxyl group equivalent was 13900, the total chlorine content was 160 ppm, the softening point was 138°C, the Mw in GPC was 1420, and the Mn was 760. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 33 mol%.

[0140] Example 3 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 502.6 parts of pH2 from Synthesis Example 1 (400 mol% relative to the hydroxyl groups of pH1), 464.6 parts of 1-naphthol (pH4) (100 mol% relative to the total hydroxyl groups of pH1 and pH2), 62.3 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH2, and pH4), 654.1 parts of B1 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH2, and pH4), and 4270 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 1288.7 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 1463 parts of activated ester resin (A3). The activated ester equivalent calculated from the amount of raw materials was 232, the phenolic hydroxyl group equivalent was 19800, the total chlorine content was 180 ppm, the softening point was 133°C, the Mw in GPC was 1480, and the Mn was 770. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 20 mol%.

[0141] Example 4 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 125.6 parts of pH2 from Synthesis Example 1 (100 mol% relative to the hydroxyl groups of pH1), 92.9 parts of 1-naphthol (pH4) (50 mol% relative to the total hydroxyl groups of pH1 and pH2), 18.7 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH2, and pH4), 196.2 parts of B1 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH2, and pH4), and 1270 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 386.6 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 437 parts of activated ester resin (A4). The activated ester equivalent calculated from the amount of raw materials charged was 231, the phenolic hydroxyl group equivalent was 18400, the total chlorine content was 130 ppm, the softening point was 142°C, the Mw in GPC was 2540, and the Mn was 1020. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 50 mol%.

[0142] Example 5 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 114.0 parts of pH3 from Synthesis Example 2 (100 mol% relative to the hydroxyl groups of pH1), 185.8 parts of 1-naphthol (pH4) (100 mol% relative to the total hydroxyl groups of pH1 and pH3), 24.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH3, and pH4), 261.6 parts of B1 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH3, and pH4), and 1600 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 515.5 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B13) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 559 parts of activated ester resin (A5). The activated ester equivalent calculated from the amount of raw materials charged was 221, the phenolic hydroxyl group equivalent was 25400, the total chlorine content was 115 ppm, the softening point was 122°C, the Mw in GPC was 1240, and the Mn was 690. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 50 mol%.

[0143] Example 6 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 125.6 parts of pH2 from Synthesis Example 1 (100 mol% relative to the hydroxyl groups of pH1), 185.8 parts of 1-naphthol (pH4) (100 mol% relative to the total hydroxyl groups of pH1 and pH2), 24.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH2, and pH4), 261.6 parts of B2 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH2, and pH4), and 1650 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 515.5 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B2) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 564 parts of activated ester resin (A6). The activated ester equivalent calculated from the amount of raw materials charged was 226, the phenolic hydroxyl group equivalent was 19800, the total chlorine content was 155 ppm, the softening point was 137°C, the Mw on GPC was 1430, and the Mn was 750. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 50 mol%.

[0144] Example 7 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1, 137.2 parts of pH5 (100 mol% relative to the hydroxyl groups of pH1), 185.8 parts of 1-naphthol (pH4) (100 mol% relative to the total hydroxyl groups of pH1 and pH5), 24.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH1, pH4, and pH5), 261.6 parts of B1 (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH1, pH4, and pH5) as an aromatic carboxylic acid halide, and 1690 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 515.5 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 575 parts of activated ester resin (A7). The activated ester equivalent calculated from the amount of raw materials charged was 230, the phenolic hydroxyl group equivalent was 22100, the total chlorine content was 110 ppm, the softening point was 125°C, the Mw in GPC was 1380, and the Mn was 740. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 50 mol%.

[0145] Comparative Example 1 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH2 from Synthesis Example 1 as an aromatic hydroxy compound, 73.9 parts of 1-naphthol (pH4) (100 mol%) relative to the hydroxyl groups of pH2, 9.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol%) relative to the total hydroxyl groups of pH2 and pH4), 104.1 parts of B1 as an aromatic carboxylic acid halide (100 mol%) relative to the total hydroxyl groups of pH2 and pH4 as acid halogen groups, and 700 parts of toluene (TL). The mixture was heated to 50°C and dissolved. While controlling the temperature in the system to below 60°C, 205.1 parts of 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol%) relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This procedure was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, toluene was removed by heating to 180°C under reduced pressure of 5 mmHg to obtain 237 parts of activated ester resin (A8). The activated ester equivalent calculated from the amount of raw materials charged was 236, with a phenolic hydroxyl group equivalent of 24000, a total chlorine content of 190 ppm, a softening point of 130°C, a GPC Mw of 1370, and a Mn of 740. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 0 mol%.

[0146] Comparative Example 2 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH3 from Synthesis Example 2 as an aromatic hydroxy compound, 81.5 parts of 1-naphthol (pH4) (100 mol%) relative to the hydroxyl groups of pH3, 10.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol%) relative to the total hydroxyl groups of pH3 and pH4), 114.7 parts of B1 as an aromatic carboxylic acid halide (100 mol%) relative to the total hydroxyl groups of pH3 and pH4 as acid halogen groups, and 730 parts of toluene (TL). The mixture was heated to 50°C and dissolved. While controlling the temperature in the system to below 60°C, 226.0 parts of 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol%) relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This procedure was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, toluene was removed by heating to 180°C under reduced pressure of 5 mmHg to obtain 251 parts of activated ester resin (A9). The activated ester equivalent calculated from the amount of raw materials charged was 227, the phenolic hydroxyl group equivalent was 14200, the total chlorine content was 140 ppm, the softening point was 124°C, the Mw in GPC was 1140, and the Mn was 620. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 0 mol%.

[0147] Comparative Example 3 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH3 from Synthesis Example 2 as an aromatic hydroxy compound, 40.7 parts of 1-naphthol (pH4) (50 mol% relative to the hydroxyl groups of pH3), 8.2 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH3 and pH4), 86.0 parts of B1 as an aromatic carboxylic acid halide (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH3 and pH4), and 560 parts of toluene (TL). The mixture was heated to 50°C and dissolved. While controlling the temperature in the system to below 60°C, 169.5 parts of 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This procedure was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, toluene was removed by heating to 180°C under reduced pressure of 5 mmHg to obtain 191 parts of activated ester resin (A10). The activated ester equivalent calculated from the amount of raw materials charged was 232, the phenolic hydroxyl group equivalent was 18000, the total chlorine content was 150 ppm, the softening point was 141°C, the Mw on GPC was 2050, and the Mn was 920. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 0 mol%.

[0148] Comparative Example 4 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 1130.9 parts of pH2 from Synthesis Example 1 (900 mol%) relative to the hydroxyl groups of pH1, 929.2 parts of 1-naphthol (pH4) (100 mol%) relative to the total hydroxyl groups of pH1 and pH2), 124.7 parts of tetra-n-butylammonium bromide (TBAB) (3 mol%) relative to the total hydroxyl groups of pH1, pH2, and pH4), 1308.2 parts of B1 as an aromatic carboxylic acid halide (100 mol%) relative to the total hydroxyl groups of pH1, pH2, and pH4 as acid halogen groups), and 8640 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. While controlling the temperature in the system to below 60°C, 2577.6 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of B1) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This operation was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, the mixture was heated to 180°C under reduced pressure of 5 mmHg to remove toluene, yielding 2920 parts of activated ester resin (A11). The activated ester equivalent calculated from the amount of raw materials was 234, the phenolic hydroxyl group equivalent was 19500, the total chlorine content was 120 ppm, the softening point was 127°C, the Mw in GPC was 1410, and the Mn was 780. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit was 10 mol%.

[0149] Comparative Example 5 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of pH1 as an aromatic hydroxy compound, 62.8 parts of pH2 from Synthesis Example 1 (50 mol%) relative to the hydroxyl groups of pH1, 139.4 parts of 1-naphthol (pH4) (100 mol%) relative to the total hydroxyl groups of pH1 and pH2), 18.7 parts of tetra-n-butylammonium bromide (TBAB) (3 mol%) relative to the total hydroxyl groups of pH1, pH2, and pH4), 196.2 parts of B1 as an aromatic carboxylic acid halide (100 mol%) relative to the total hydroxyl groups of pH1, pH2, and pH4 as acid halogen groups, and 1210 parts of toluene (TL), and the mixture was heated to 50°C to dissolve. When 386.6 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen group of B1) were added dropwise over 3 hours while controlling the temperature in the system to below 60°C, a white solid precipitated during the process, and the desired active ester resin could not be obtained. The content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit, calculated from the amount of raw materials used, was 67 mol%.

[0150] Comparative Example 6 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser was charged with 100 parts of PH1 as an aromatic hydroxy compound, 92.9 parts of 1-naphthol (PH4) (100 mol%) relative to the hydroxyl groups of PH1, 12.5 parts of tetra-n-butylammonium bromide (TBAB) (3 mol%) relative to the total hydroxyl groups of PH1 and PH4), 130.8 parts of B1 as an aromatic carboxylic acid halide (100 mol%) relative to the total hydroxyl groups of PH1 and PH4 as acid halogen groups, and 770 parts of toluene (TL). The mixture was heated to 50°C and dissolved. While controlling the temperature in the system to 60°C or lower, 257.7 parts of a 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol%) relative to the acid halogen groups of B1) were added dropwise over 3 hours. However, a white solid precipitated during the process, and the desired active ester resin could not be obtained. Furthermore, the content of the structure derived from the aromatic polyvalent hydroxy compound represented by formula (1) in the polyaryloxy unit, calculated from the amount of raw materials used, was 100 mol%.

[0151] Example 8 A 100 part A1 was used as a curing agent, 113 parts E1 as an epoxy resin, and 0.56 parts C1 as a curing accelerator. These were mixed and dissolved in toluene to obtain an epoxy resin composition varnish with a non-volatile content of 50%. The obtained epoxy resin composition varnish was impregnated into glass cloth (manufactured by Nitto Boseki Co., Ltd., WEA 7628 XS13, 0.18 mm thick). The impregnated glass cloth was dried in a hot air circulating oven at 130°C for 5 minutes to obtain a prepreg.

[0152] The obtained prepreg was loosened and sieved to obtain a 100-mesh pass prepreg powder. The obtained prepreg powder was placed in a fluororesin mold and subjected to a vacuum press at 2 MPa under the temperature conditions of 130°C for 15 minutes + 210°C for 80 minutes to obtain a 70 mm square × 0.5 mm thick test specimen. The glass transition temperature, relative permittivity, and dielectric loss tangent of the test specimen are shown in Table 1.

[0153] Examples 9-14 and Comparative Examples 7-10 were prepared using the amounts (parts) shown in Table 1, and the same procedure as in Example 8 was followed to obtain test specimens. The results are shown in Table 1.

[0154]

[0155] As is clear from these results, the activated ester resins obtained in the examples, and the resin compositions containing them, exhibit very good low dielectric properties and can provide cured resin products with excellent heat resistance.

Claims

1. An active ester resin comprising polyaryloxy units, monoaryloxy units, and polyarylcarbonyl units, wherein the polyaryloxy units contain a structure derived from an aromatic polyvalent hydroxy compound represented by the following formula (1), and the content of the structure derived from the aromatic polyvalent hydroxy compound represented by the following formula (1) in the polyaryloxy units is more than 10 mol% and 60 mol% or less. Here, R １ Each of these independently represents a hydrocarbon group having 1 to 8 carbon atoms. i is an integer from 0 to 3.

2. The active ester resin according to claim 1, characterized in that the polyaryloxy unit includes structures derived from aromatic polyhydric hydroxy compounds other than the unit represented by formula (1) above, as structures derived from aromatic polyhydric hydroxy compounds represented by the following formula (2) and / or formula (3). Here, Ar １ Each of these is independently an aromatic ring group of any of the following: a benzene ring, a naphthalene ring, a diphenylmethane ring, or a biphenyl ring. These aromatic ring groups may have substituents of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. １１ R is a divalent hydrocarbon group having 1 to 12 carbon atoms or a divalent group represented by formula (2a). １１ Each of these independently represents a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. ３ These are directly bonded hydrocarbon groups with 1 to 20 carbon atoms, -CO-, -O-, -S-, and -SO ２ - and -C (CF ３ ) ２ It is a divalent group selected from the group consisting of -. m indicates the number of repetitions, and its average value is a number between 1 and 5. k is 0 or 1.

3. The activated ester resin according to claim 1, characterized in that the content of monoaryloxy units is 10 mol% or more and 200 mol% or less relative to the content of polyaryloxy units.

4. The active ester resin according to claim 1, characterized in that it contains, as a monoaryloxy unit, a structure derived from an aromatic monohydroxy compound represented by the following formula (4) or formula (4'). Here, Ar ２ is each independently an aromatic ring group of any one of a benzene ring, a naphthalene ring, a diphenylmethane ring or a biphenyl ring, and these aromatic ring groups may have, as a substituent, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms or an aralkyloxy group having 7 to 12 carbon atoms. R ４ is a divalent group selected from the group consisting of a direct bond, a hydrocarbon group having 1 to 20 carbon atoms, -CO-, -O-, -S-, -SO ２ -, and -C(CF ３ ) ２ -. R １４ is a divalent group selected from the group consisting of -CH ２ -, -C(CH ３ ) ２ -, -CH(CH ３ )-, and -C(CF ３ ) ２ -. k is 0 or 1.

5. The active ester resin according to claim 1, wherein the polyarylcarbonyl unit is a unit represented by the following formula (5). Here, Ar ３ Each of these is independently an aromatic ring group consisting of a benzene ring, a naphthalene ring, a diphenylmethane ring, or a biphenyl ring, and these aromatic ring groups may have substituents of an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an aryl group having 6 to 11 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, an aryloxy group having 6 to 11 carbon atoms, or an aralkyloxy group having 7 to 12 carbon atoms. ５ These are directly bonded hydrocarbon groups with 1 to 20 carbon atoms, -CO-, -O-, -S-, and -SO ２ -, and -C(CF ３ ) ２ It is a divalent group selected from the group consisting of -. k is 0 or 1.

6. A method for producing an active ester resin from an aromatic hydroxy compound, which includes an aromatic polyhydric hydroxy compound and an aromatic monohydroxy compound, and an aromatic carboxylic acid or its acid halide, characterized in that the aromatic polyhydric hydroxy compound contains an aromatic polyhydric hydroxy compound represented by the following formula (1'), and the content of the aromatic polyhydric hydroxy compound represented by the following formula (1') in the total aromatic polyhydric hydroxy compound is more than 10 mol% and 60 mol% or less. Here, R １ Each of these independently represents a hydrocarbon group having 1 to 8 carbon atoms. i is an integer from 0 to 3.

7. An epoxy resin composition comprising an active ester resin according to any one of claims 1 to 5 and an epoxy resin as essential components.

8. A cured product obtained by curing the epoxy resin composition according to claim 7.

9. A prepreg characterized by using the epoxy resin composition described in claim 7.

10. A resin sheet characterized by using the epoxy resin composition described in claim 7.

11. A laminate characterized by using the epoxy resin composition described in claim 7.

12. A circuit board material characterized by using the epoxy resin composition described in claim 7.

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