Modified epoxy resin, resin composition, cured product, laminate for electric / electronic circuits, and method for producing modified epoxy resin

Abstract

To provide a modified epoxy resin having excellent solvent solubility and resin compatibility, a resin composition containing the same, a cured product thereof having excellent thermostability and dielectric properties, and a laminate for electric / electronic circuits.SOLUTION: The present invention relates to a modified epoxy resin represented by a formula (1) (where each X is a divalent group, including at least a divalent group represented by a formula (2)).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a modified epoxy resin having excellent solvent solubility and resin compatibility, a resin composition containing this modified epoxy resin and a curing agent, a cured product thereof having excellent heat resistance and dielectric properties, and a laminate for electric and electronic circuits made from the resin composition. [Background technology]

[0002] Epoxy resins are widely used in fields such as paints, civil engineering, adhesives, and electrical materials due to their excellent heat resistance, adhesive properties, chemical resistance, water resistance, mechanical strength, and electrical properties. Furthermore, film-forming properties can be imparted by increasing their molecular weight through various methods. Such high-molecular-weight epoxy resins are called phenoxy resins. In particular, bisphenol A-type phenoxy resins are primarily used as base resins for paint varnishes and film molding, and are added to epoxy resin varnishes to adjust flowability and improve toughness and adhesive properties when cured. Furthermore, those containing phosphorus or bromine atoms in their skeletons are used as flame retardants incorporated into epoxy resin compositions and thermoplastic resins.

[0003] Epoxy resins used in electrical materials such as laminates for electric and electronic circuits require solvent solubility and resin compatibility in addition to heat resistance, etc. In recent years, information devices have rapidly become smaller and more powerful, and as a result, materials used in the fields of semiconductors and electronic components are required to have higher performance than ever before, especially low dielectric properties to accompany thinner and more highly functional substrates.

[0004] In response to such demands, a method has been proposed for improving heat resistance by increasing the bulk of molecular chains and suppressing micro-Brownian motion. Patent Document 1 discloses a phenoxy resin with excellent heat resistance, which is obtained by reacting a bulky bisphenol compound with a difunctional epoxy resin, and a cured product thereof. However, while this method can impart excellent heat resistance to the phenoxy resin and its cured product, there is a problem in that the dielectric properties are not improved.

[0005] Meanwhile, a method has been proposed for improving dielectric properties by converting the hydroxyl groups present in the side chains of phenoxy resins into esters using acetyl or benzoyl groups. Patent Document 2 discloses that phenoxy resins obtained by reacting a bifunctional epoxy resin with a diester compound and their cured products have excellent dielectric properties, but there is a problem in that their heat resistance is still insufficient. Patent Document 3 discloses that cured products of epoxy resins obtained by reacting a diacylated bisphenol compound with a bisphenol-type epoxy resin have low viscosity and high heat resistance, but only dicyandiamide is disclosed as a curing agent, and when a phenol-based curing agent is used, there is a problem in that heat resistance is poor. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-231428 [Patent Document 2] Japanese Patent Application Laid-Open No. 2016-089165 [Patent Document 3] Japanese Patent Application Publication No. 8-333437 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention aims to provide an epoxy resin having excellent solvent solubility and resin compatibility, and to provide a cured product having excellent heat resistance and dielectric properties by curing a resin composition containing the epoxy resin. [Means for solving the problem]

[0008] In order to solve the above problems, the present inventors have conducted extensive research into epoxy resins and have found that epoxy resins having a specific structure have excellent solvent solubility and resin compatibility, and further found that a cured product obtained by curing a resin composition containing such an epoxy resin has excellent heat resistance and dielectric properties, thereby completing the present invention.

[0009] That is, the present invention is a modified epoxy resin represented by the following formula (1) and having an epoxy equivalent of 400 to 100,000 g / eq. [ka] In the formula, X is a divalent group and has at least a divalent group represented by the above formula (2). Y is independently a hydrogen atom, an acyl group having 2 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of the acyl group is the above. n is the average number of repetitions and is 1 or more and 500 or less. A is an arylene group, and R 1 and R 2 are independently divalent groups having no active hydrogen and having a heteroatom.

[0010] The present invention also provides a resin composition containing the above-mentioned modified epoxy resin and a curing agent. The resin composition preferably contains 0.1 to 100 parts by mass of the curing agent as solid content per 100 parts by mass of the solid content of the modified epoxy resin.

[0011] The resin composition contains the modified epoxy resin, another epoxy resin, and a curing agent, and the mass ratio of the solid content of the modified epoxy resin to the other epoxy resin can be 99 / 1 to 1 / 99. This resin composition preferably contains 0.1 to 100 parts by mass of the curing agent as solid content per 100 parts by mass of the total solid content of the modified epoxy resin and other epoxy resins.

[0012] The curing agent to be blended in the resin composition is at least one selected from the group consisting of acrylic ester resins, melamine resins, urea resins, phenolic resins, acid anhydride compounds, amine compounds, imidazole compounds, amide compounds, cationic polymerization initiators, organic phosphines, polyisocyanate compounds, blocked isocyanate compounds, carbodiimide compounds, and active ester curing agents.

[0013] The present invention also relates to a cured product obtained by curing the above-mentioned resin composition. Furthermore, the present invention relates to a laminate for electric / electronic circuits, which is made using the above resin composition.

[0014] The present invention also provides a method for producing the above modified epoxy resin, which comprises reacting a bifunctional epoxy resin represented by the following formula (3) with a compound represented by the following formula (4): [ka] In the formula, X 1 , X 2 is a divalent group, and X 1 and / or X 2 contains a divalent group represented by the above formula (2). G is a glycidyl group. Q is an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of the acyl group is the above. Here, the compound represented by formula (4) may be a mixture of two or more selected from compounds in which both Qs are acyl groups, compounds in which one is an acyl group, and compounds in which both are hydrogen atoms. m is the average number of repeating units and is 0 to 6.

[0015] The method for producing the modified epoxy resin is characterized by reacting 0.05 to 2.0 moles of an acid anhydride represented by the following formula (6) with 1 mole of an alcoholic hydroxyl group equivalent of the epoxy resin represented by the following formula (5). [ka] In the formula, X is a divalent group and includes a divalent group represented by the above formula (2). L is independently a hydrogen atom or a glycidyl group. T is an acyl group having 2 to 20 carbon atoms. n is the average number of repetitions and is 1 or more and 500 or less. [Effects of the Invention]

[0016] According to the present invention, a modified epoxy resin having excellent dielectric properties and heat resistance can be provided. Furthermore, a resin composition using this modified epoxy resin can provide a cured product having excellent dielectric properties and heat resistance. Therefore, the modified epoxy resin and resin composition of the present invention are applicable to a variety of fields, such as adhesives, paints, civil engineering and building materials, and insulating materials for electric and electronic components, and are particularly useful as insulating casting materials, laminate materials, and encapsulating materials in the electric and electronic fields. The phenoxy resin of the present invention and a resin composition containing the same can be suitably used in multilayer printed wiring boards, laminates for electric and electronic circuits such as capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor encapsulating materials, underfill materials, interchip fill materials for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, and the like. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a GPC chart of the modified epoxy resin of Example 1. [Figure 2] 1 is an IR chart of the modified epoxy resin of Example 1. [Figure 3] 1 is a GPC chart of the modified epoxy resin of Example 8. [Figure 4] 1 is an IR chart of the modified epoxy resin of Example 8. [Figure 5] 1 is a GPC chart of the modified epoxy resin of Example 9. [Figure 6] 1 is an IR chart of the modified epoxy resin of Example 9. DETAILED DESCRIPTION OF THE INVENTION

[0018] The modified epoxy resin of the present invention is an epoxy resin represented by the above formula (1) and having an epoxy equivalent (g / eq.) of 400 to 100,000, and has a structure represented by the above formula (2), in which some or all of the hydrogen atoms in the hydroxyl groups have been substituted (modified) with acyl groups (Z). If the epoxy equivalent is within the above range, the modified epoxy resin can participate in the curing reaction and be incorporated into a crosslinked structure. The epoxy equivalent is preferably 500 to 80,000, more preferably 600 to 70,000, and even more preferably 700 to 60,000. For film applications, film-forming properties are required, so the epoxy equivalent is desirably higher, 5,000 to 100,000, more preferably 10,000 to 100,000, and even more preferably 20,000 to 100,000. On the other hand, in applications such as substrates where the resin is used by impregnating a substrate, good impregnation properties are required, so the epoxy equivalent is rather desirably low, 400 to 10,000, more preferably 400 to 5,000, and even more preferably 400 to 3,000.

[0019] The weight-average molecular weight (Mw) of the modified epoxy resin of the present invention is preferably 500 or more and 200,000 or less. Here, an Mw of less than 500 is undesirable because there is a risk of incorporation of less of a structure that improves the heat resistance of the cured product. An Mw of more than 200,000 is undesirable because it may result in reduced compatibility and difficulty in handling the resin. Furthermore, from the viewpoint of improving the film-forming properties of the modified epoxy resin, Mw is preferably 5,000 or more, more preferably 10,000 or more, and even more preferably 15,000 or more. From the viewpoint of improving compatibility and handleability, Mw is more preferably 160,000 or less, even more preferably 120,000 or less, and particularly preferably 80,000 or less. For substrate applications in which the resin is impregnated into a substrate, Mw may be 10,000 or less, more preferably 5,000 or less. The Mw of the modified epoxy resin can be measured by the gel permeation chromatography method (GPC method) described in the examples.

[0020] The modified epoxy resin of the present invention has a structure in which hydrogen atoms in hydroxyl groups are replaced (modified) with acyl groups, resulting in low polarity, excellent dielectric properties, low moisture absorption, solvent solubility, and resin compatibility. Furthermore, the structure represented by formula (2) above provides excellent heat resistance.

[0021] The modified epoxy resin of the present invention can be advantageously obtained by the production method of the present invention. In this specification, the modified epoxy resin obtained by the production method of the present invention will sometimes be referred to as the "modified epoxy resin of the present invention," the cured product obtained by curing the resin composition of the present invention will sometimes be referred to as the "cured product of the present invention," and the production method of the modified epoxy resin of the present invention will sometimes be referred to as the "production method of the present invention."

[0022] In the above formula (1), X is a divalent group, and is either a divalent group represented by the above formula (2) or a divalent group other than these, but the divalent group represented by formula (2) is always included as a whole. Furthermore, the divalent group represented by formula (2) preferably accounts for 1 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and particularly preferably 40 mol% or more, based on the total number of moles of X. Outside this range, heat resistance may be impaired.

[0023] In formula (2), A is an arylene group, and the arylene group is not particularly limited. Examples of the arylene group include monocyclic aromatic groups such as a phenylene group and polycyclic aromatic groups such as a naphthalene ring. The arylene group also includes derivatives in which a hydrogen atom bonded to the aromatic ring is substituted with a functional group such as an alkyl group, an alkenyl group, an alkynyl group, a formyl group, an alkyloxy group, an alkenyloxy group, an alkynyloxy group, an alkylcarbonyl group, an alkenylcarbonyl group, or an alkynylcarbonyl group. The alkyl group is not particularly limited, and is preferably an alkyl group having 1 to 18 carbon atoms, more preferably an alkyl group having 1 to 10 carbon atoms. Specific examples include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, and a decyl group. As these arylene groups, an unsubstituted phenylene group, an unsubstituted naphthylene group, a phenylene group having an alkyl group with 1 to 10 carbon atoms, or a naphthylene group having an alkyl group with 1 to 10 carbon atoms is preferred.

[0024] R in the above formula (2) 1 and R 2 are each independently a divalent group having no active hydrogen and a heteroatom, -R 1 -R 2 -Contains at least one hetero element in the structure.

[0025] In the present invention, "active hydrogen" refers to a hydrogen atom directly bonded to any of an oxygen atom, a sulfur atom, and a nitrogen atom. These active hydrogens are highly reactive and react with various reagents. Examples of substituents having active hydrogen include -OH, -SH, -NH2, -NH-, and -COOH. When active hydrogen is present in the R 1 and R 2 If at least one of R in formula (2) is present, gelation during production and deterioration of stability during storage may occur. 1 and R 2 In the above, it does not have active hydrogen.

[0026] In the present invention, the term "heteroelement" means nitrogen, phosphorus, arsenic, antimony, oxygen, sulfur, selenium, and tellurium. 1 and R 2 Preferred examples of the group include -O-, -N(R 3 )-(R 3 (C1-C10 hydrocarbon group), -CO-, -SO2-, -S-, -PO2-, etc. Among these, R 1 is preferably —O— or —N(Ph)— (Ph: phenyl group), and R 2 As the alkyl group, -CO- and -SO2- are preferred.

[0027] Examples of the divalent group represented by the above formula (2) include, but are not limited to, divalent groups represented by the following formulas (2a) to (2i). Among these, (2a), (2b), (2c), (2d), (2g), (2h), and (2i) are preferred, and (2 a), (2c), (2d), (2g), (2h), and (2i) are more preferred, and (2a), (2c), (2g), (2h), and (2i) are even more preferred.

[0028] [ka]

[0029] The divalent group other than the divalent group structure represented by formula (2) is preferably a divalent hydrocarbon group or a hydrocarbon group which may have in the hydrocarbon chain a group such as -O-, -CO-, -S-, -COO-, -SO-, -SO2-, etc. Examples of these divalent groups include an aromatic skeleton representing a residual skeleton obtained by removing two hydroxyl groups from an aromatic diol compound, an aliphatic skeleton representing a residual skeleton obtained by removing two hydroxyl groups from an aliphatic diol compound, and an alicyclic skeleton representing a residual skeleton obtained by removing two hydroxyl groups from an alicyclic diol compound. These groups are derived from the residual skeleton obtained by removing two glycidyloxy groups from a difunctional epoxy resin (diglycidyl ether compound), the residual skeleton obtained by removing two ester structures from a diester compound, and the residual skeleton obtained by removing two hydroxyl groups from a difunctional phenol compound.

[0030] Specific examples of aromatic skeletons having a structure in which two hydroxyl groups have been removed from an aromatic diol compound include bisphenol types which may be unsubstituted or have an alkyl group having 1 to 10 carbon atoms as a substituent, such as bisphenol A, bisphenolacetophenone, bisphenol AF, bisphenol AD, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol S, bisphenol P, bisphenol PH, bisphenoltrimethylcyclohexane, and bisphenolcyclohexane; benzene types such as dihydroxyphenyls which may be unsubstituted or have an alkyl group having 1 to 10 carbon atoms as a substituent, such as hydroquinone, resorcinol, and catechol; naphthalene types such as dihydroxynaphthalenes which may be unsubstituted or have an alkyl group having 1 to 10 carbon atoms as a substituent; biphenyl types such as dihydroxybiphenyls which may be unsubstituted or have an alkyl group having 1 to 10 carbon atoms as a substituent; bisphenolfluorene and Fluorene-type fluorenes such as bisphenolfluorenes and bisnaphtholfluorenes, which may be unsubstituted or have an alkyl group having 1 to 10 carbon atoms as a substituent, such as biscresolfluorene; 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), 10-(2,7-dihydroxynaphthyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-NQ), 10-(1 and phosphorus-containing phenols which may be unsubstituted or have an alkyl group, an aryl group or an aralkyl group having 1 to 10 carbon atoms as a substituent, such as 1,4-dihydroxy-2-naphthyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, diphenylphosphinylhydroquinone, diphenylphosphinyl-1,4-dioxynaphthalene, 1,4-cyclooctylenephosphinyl-1,4-phenyldiol and 1,5-cyclooctylenephosphinyl-1,4-phenyldiol.

[0031] Specific examples of the aliphatic skeleton include alkylene glycol skeletons such as ethylene glycol, propylene glycol, and butylene glycol.

[0032] Specific examples of the alicyclic skeleton include hydrogenated bisphenol skeletons such as hydrogenated bisphenol A, hydrogenated bisphenol F, and hydrogenated bisphenol acetophenone.

[0033] In formula (1), Y is independently a hydrogen atom, an acyl group having 2 to 20 carbon atoms, or a glycidyl group. When Y is a hydrogen atom, a hydroxyl group is provided at the end; when Y is an acyl group, an ester group is provided at the end; and when Y is a glycidyl group, an epoxy group is provided at the end. An acyl group is represented by R-CO-, where R is a hydrocarbon group having 1 to 19 carbon atoms. It is advisable to control the proportion of these end groups depending on the application. In the acyl group (R—CO—), the hydrocarbon group having 1 to 19 carbon atoms represented by R is preferably an alkyl group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 13 carbon atoms. The alkyl group having 1 to 12 carbon atoms may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, a neopentyl group, a t-pentyl group, a cyclopentyl group, an n-hexyl group, an isohexyl group, a cyclohexyl group, an n-heptyl group, a cycloheptyl group, a methylcyclohexyl group, an n-octyl group, a cyclooctyl group, an n-nonyl group, a 3,3,5-trimethylcyclohexyl group, an n-decyl group, a cyclodecyl group, an n-undecyl group, an n-dodecyl group, and a cyclododecyl group. Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, a tolyl group, an ethylphenyl group, a xylyl group, an n-propylphenyl group, an isopropylphenyl group, a mesityl group, a naphthyl group, and a methylnaphthyl group. Examples of aralkyl groups having 7 to 13 carbon atoms include, but are not limited to, benzyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl, phenethyl, 2-phenylisopropyl, and naphthylmethyl groups. Among these, acyl groups having a hydrocarbon group of 1 to 7 carbon atoms are more preferred, with acetyl, propanoyl, butanoyl, benzoyl and methylbenzoyl groups being even more preferred, and acetyl and benzoyl groups being particularly preferred.

[0034] In formula (1), Z is an acyl group having 2 to 20 carbon atoms or a hydrogen atom. 5 mol % or more of Z are acyl groups, and the remainder are hydrogen atoms. 10 mol % or more, preferably 50 mol % or more, more preferably 70 mol % or more, and even more preferably 90 mol % or more of Z are acyl groups. On the other hand, the upper limit is 100%, but in terms of reaction, it may be substantially about 95%. The acyl groups are the same as those exemplified for Y above, and preferred acyl groups are also the same. When all Z's (100 mol%) are acyl groups, the modified epoxy resin of the present invention does not contain secondary hydroxyl groups, and the dielectric properties and moisture resistance can be further improved. On the other hand, for example, when fine-tuning the adhesion to metals, it is possible to intentionally allow an appropriate amount of secondary hydroxyl groups to be present in the modified epoxy resin of the present invention by leaving some of the Z's as hydrogen atoms, as long as this does not significantly affect other physical properties such as moisture resistance.

[0035] In formula (1), n ​​is the number of repeating units and is an average value. The value ranges from 1 to 500. From the viewpoint of moldability and handleability, it is preferably from 1 to 400, more preferably from 1 to 300. The number n can be calculated from the number average molecular weight (Mn) obtained by GPC.

[0036] The modified epoxy resin of the present invention is one in which some or all of the secondary hydroxyl groups are acylated, and can be obtained by various methods. Preferred production methods include, for example, the following production method. (A): A production method in which a bifunctional epoxy resin represented by the above formula (3) is reacted with a diester compound and / or a bifunctional phenol compound represented by the above formula (4). Hereinafter, this method may be referred to as production method (A). (B): A production method in which an epoxy resin represented by the above formula (5) (sometimes referred to as epoxy resin (a) to distinguish it from the modified epoxy resin of the present invention) is reacted with an acid component (acylating agent) such as an acid anhydride of an organic acid, an organic acid halide, or an organic acid ester. Hereinafter, this method may be referred to as production method (B). The modified epoxy resins obtained by the production methods (A) and (B) are the modified epoxy resins of the present invention, and are represented by the same formula (1).

[0037] The above production method (A) is a method in which a bifunctional epoxy resin represented by formula (3) is reacted with a compound represented by formula (4). In the above formula (3), G is a glycidyl group, m is the number of repetitions, the average value of which is 0 or more and 6 or less, and preferably 0 or more and 3 or less. In formula (4), Q is an acyl group having 2 to 20 carbon atoms. In formula (4), 5 mol % or more of Q are acyl groups having 2 to 20 carbon atoms, and the remainder are hydrogen atoms. Here, the compound represented by formula (4) may be a mixture of two or more compounds selected from diester compounds in which both Qs are acyl groups, monoester compounds in which one is an acyl group and the other is a hydrogen atom, and diphenol compounds in which both Qs are hydrogen atoms. The compound represented by formula (4) is called a diester compound. The diester compound may be a diester compound in which both Qs are acyl groups, or a compound (mixture) in which the main component (50% or more) is such a compound.

[0038] X in equation (3) 1 and X in equation (4) 2 is selected to give X in formula (1). Therefore, either the epoxy resin represented by formula (3) or the compound represented by formula (4), or both, contain a divalent group represented by formula (2), and this group is X 1 and X 2It is preferable that the divalent group represented by formula (2) is contained in an amount of 1 to 100 mol % relative to the total number of moles of the divalent group represented by formula (2). From the viewpoint of fully exhibiting the heat resistance attributable to the divalent group represented by formula (2), the divalent group represented by formula (2) is more preferably 10 mol % or more, even more preferably 20 mol % or more, and particularly preferably 40 mol % or more. The modified epoxy resin of the present invention necessarily contains a divalent group represented by formula (2), and as long as this requirement is met, the structure of formula (2) may be contained in either the starting bifunctional epoxy resin and / or the compound represented by formula (4), and the proportion thereof is not limited. 1 Or X in formula (4) 2 When the divalent group represented by formula (2) is not included, X 1 or X 2 Another divalent group can be introduced into

[0039] The bifunctional epoxy resin used in the production method (A) of the present invention is an epoxy resin represented by the above formula (3), for example, HO-X 1 Examples of epoxy resins include those obtained by reacting a bifunctional phenol compound represented by —OH with epihalohydrin in the presence of an alkali metal compound. 1 is X in the above formula (3) 1 is the same as:

[0040] The raw material epoxy resin represented by formula (3) preferably has an epoxy equivalent of 100 to 400 g / eq., more preferably 300 g / eq or less. The m value in formula (3) is preferably 0 to 1, more preferably 0.3 or less.

[0041] Examples of epihalohydrins include epichlorohydrin and epibromohydrin. Examples of alkali metal compounds include alkali metal hydroxides such as sodium hydroxide, lithium hydroxide, and potassium hydroxide; alkali metal salts such as sodium carbonate, sodium bicarbonate, sodium chloride, lithium chloride, and potassium chloride; alkali metal alkoxides such as sodium methoxide and sodium ethoxide; alkali metal salts of organic acids such as sodium acetate and sodium stearate; alkali metal phenoxides, sodium hydride, and lithium hydride.

[0042] In the reaction of a bifunctional phenol compound with epihalohydrin to obtain the starting epoxy resin, an alkali metal compound is used in an amount of 0.80 to 1.20 times by mole, preferably 0.85 to 1.05 times by mole, relative to the functional groups in the bifunctional phenol compound. Less than this amount is undesirable because the amount of residual hydrolyzable chlorine increases. The alkali metal compound is used in the form of an aqueous solution, an alcohol solution, or a solid.

[0043] In the epoxidation reaction, an excess amount of epihalohydrin is used relative to the bifunctional phenol compound. Typically, 1.5 to 15 moles of epihalohydrin are used per mole of functional groups in the bifunctional phenol compound, preferably 2 to 10 moles, and more preferably 5 to 8 moles. If the amount is greater than this, production efficiency decreases, and if it is less than this, the amount of high molecular weight epoxy resin produced increases, making it unsuitable as a raw material.

[0044] The epoxidation reaction is usually carried out at a temperature of 120°C or lower. If the reaction temperature is high, the amount of so-called difficultly hydrolyzable chlorine increases, making it difficult to achieve high purity. The temperature is preferably 100°C or lower, and more preferably 85°C or lower.

[0045] When the bifunctional phenol compound is reacted with epihalohydrin, m usually becomes greater than 0. In order to make m 0, an epoxy resin produced by a known method can be highly purified by distillation, crystallization, or the like, or the bifunctional phenol compound can be allylated and then epoxidized by oxidizing the olefin moiety.

[0046] The diester compound used in the production method (A) of the present invention can be obtained, for example, by acylation of the bifunctional phenol compound by a condensation reaction with an acid anhydride of an organic acid, a halide of an organic acid, or an organic acid.

[0047] By using an epoxy resin in which m in formula (3) is 0 as the raw material, the modified epoxy resin of the present invention will not contain secondary hydroxyl groups, and the dielectric properties and moisture resistance can be further improved. Furthermore, for example, when fine-tuning the adhesion to metal, by using an epoxy resin with an appropriate m number, it is possible to intentionally allow an appropriate amount of secondary hydroxyl groups to be present in the modified epoxy resin of the present invention, within a range that does not significantly affect other physical properties such as moisture resistance.

[0048] The amounts of the bifunctional epoxy resin and diester compound used need to be adjusted depending on the epoxy equivalent of the desired modified epoxy resin, but a ratio of 0.3 to 1.0 equivalents of ester groups per equivalent of epoxy groups is preferred. This equivalent ratio facilitates high molecular weight formation with epoxy groups at the molecular terminals. It is also possible to replace a portion of the diester compound with the bifunctional phenol compound. As mentioned above, this allows for the presence of an appropriate amount of secondary hydroxyl groups in the modified epoxy resin of the present invention, allowing for fine adjustment of physical properties. In the production method (A), a polymerization reaction and an esterification reaction of secondary hydroxyl groups occur, resulting in an increase in Mw and the production of a modified epoxy resin.

[0049] In the production method (A), a catalyst may be used. The catalyst may be any compound having catalytic activity that promotes the reaction between the epoxy group and the ester group. Examples of the catalyst include tertiary amines, cyclic amines, imidazoles, organic phosphorus compounds, and quaternary ammonium salts. These catalysts may be used alone or in combination of two or more.

[0050] Examples of tertiary amines include, but are not limited to, triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, 2,4,6-tris(dimethylaminomethyl)phenol, and the like.

[0051] Examples of cyclic amines include, but are not limited to, 1,4-diazabicyclo[2,2,2]octane (DABCO), 1,8-diazabicyclo[5,4,0]undecene-7 (DBU), 1,5-diazabicyclo[4,3,0]nonene-5 (DBN), N-methylmorpholine, pyridine, and N,N-dimethylaminopyridine (DMAP).

[0052] Examples of imidazoles include, but are not limited to, 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-phenylimidazole.

[0053] Examples of the organic phosphorus compounds include phosphines such as tri-n-propylphosphine, tri-n-butylphosphine, diphenylmethylphosphine, triphenylphosphine, tris(p-tolyl)phosphine, tricyclohexylphosphine, tri(t-butyl)phosphine, tris(p-methoxyphenyl)phosphine, paramethylphosphine, 1,2-bis(dimethylphosphino)ethane, and 1,4-bis(diphenylphosphino)butane; tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, and tetramethylphosphonium iodide; Examples of the phosphonium salts include, but are not limited to, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, and triphenylbenzylphosphonium bromide.

[0054] Examples of quaternary ammonium salts include, but are not limited to, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium hydroxide, triethylmethylammonium chloride, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetrapropylammonium bromide, tetrapropylammonium hydroxide, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, benzyltrimethylammonium chloride, benzyltrimethylammonium bromide, benzyltrimethylammonium hydroxide, benzyltributylammonium chloride, and phenyltrimethylammonium chloride.

[0055] Among the catalysts listed above, 4-(dimethylamino)pyridine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, 2-ethyl-4-methylimidazole, tris(p-tolyl)phosphine, tricyclohexylphosphine, tri(t-butyl)phosphine, and tris(p-methoxyphenyl)phosphine are preferred, and 4-(dimethylamino)pyridine, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, and 2-ethyl-4-methylimidazole are particularly preferred.

[0056] The amount of catalyst used is usually 0.001 to 1 mass% of the reaction solids. However, when these compounds are used as catalysts, the catalyst may remain as residue in the resulting modified epoxy resin, which may deteriorate the insulating properties of the printed wiring board or shorten the pot life of the composition. Therefore, the nitrogen content derived from the catalyst in the modified epoxy resin is preferably 0.5 mass% or less, more preferably 0.3 mass% or less. Furthermore, the phosphorus content derived from the catalyst in the modified epoxy resin is preferably 0.5 mass% or less, more preferably 0.3 mass% or less.

[0057] In the production method (A), a reaction solvent may be used. Any solvent that dissolves the modified epoxy resin may be used. Examples of the solvent include aromatic solvents, ketone solvents, amide solvents, glycol ether solvents, and ester solvents. These solvents may be used alone or in combination of two or more.

[0058] Examples of aromatic solvents include benzene, toluene, and xylene.

[0059] Examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, diisobutyl ketone, isophorone, methylcyclohexanone, and acetophenone.

[0060] Examples of amide solvents include formamide, N-methylformamide, N,N-dimethylformamide (DMF), acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, and N-methylpyrrolidone.

[0061] Examples of glycol ether solvents include ethylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and ethylene glycol mono-n-butyl ether; diethylene glycol dialkyl ethers such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol mono-n-butyl ether; propylene glycol monoalkyl ethers such as propylene glycol monomethyl ether, propylene glycol monoethyl ether, and propylene glycol mono-n-butyl ether; ethylene glycol dialkyl ethers such as ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and ethylene glycol dibutyl ether; and polyethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, and triethylene glycol dibutyl ether. ethylene glycol dialkyl ethers, propylene glycol dialkyl ethers such as propylene glycol dimethyl ether, propylene glycol diethyl ether, and propylene glycol dibutyl ether; polypropylene glycol dialkyl ethers such as dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol dibutyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl ether, and tripropylene glycol dibutyl ether; ethylene glycol monoalkyl ether acetates such as ethylene glycol monoethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate; diethylene glycol monoethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate, and triethylene glycol monoethyl ether acetate;Examples include polyethylene glycol monoalkyl ether acetates such as triethylene glycol monobutyl ether acetate, and propylene glycol monoalkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monobutyl ether acetate.

[0062] Examples of ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, benzyl acetate, ethyl propionate, ethyl butyrate, butyl butyrate, valerolactone, and butyrolactone.

[0063] Other solvents include, for example, dioxane, dimethyl sulfoxide, sulfolane, γ-butyrolactone, and the like.

[0064] In production method (A), the solids concentration during the reaction is preferably 35 to 95% by mass, more preferably 50 to 90% by mass, and even more preferably 70 to 90% by mass. If a highly viscous product is produced during the reaction, the reaction can be continued by adding additional solvent. After the reaction is complete, the solvent can be removed or further added as necessary.

[0065] The reaction temperature is preferably within a range that does not decompose the catalyst used. If the reaction temperature is too high, the catalyst may decompose, halting the reaction or degrading the resulting modified epoxy resin. If the reaction temperature is too low, the reaction may not proceed sufficiently to achieve the desired molecular weight. Therefore, the reaction temperature is preferably 50 to 230°C, more preferably 120 to 200°C. The reaction time is typically 1 to 12 hours, preferably 3 to 10 hours. When using a low-boiling solvent such as acetone or methyl ethyl ketone, the reaction temperature can be maintained by conducting the reaction under high pressure using an autoclave. If the heat of reaction needs to be removed, this is usually achieved by evaporating, condensing, and refluxing the solvent using the heat of reaction, by indirect cooling, or by a combination of these methods.

[0066] Next, the production method (B) of the present invention will be described. Production method (B) is a method for obtaining a modified epoxy resin represented by formula (1) having an epoxy equivalent of 400 to 100,000 g / eq., i.e., the modified epoxy resin of the present invention, by reacting an epoxy resin represented by formula (5) with 0.05 to 2.0 moles of an acid anhydride represented by formula (6) per mole of alcoholic hydroxyl group equivalent of the epoxy resin.

[0067] The starting epoxy resin (a) represented by formula (5) essentially contains a divalent group represented by formula (2) in X of formula (5). This epoxy resin (a) can be obtained by a conventionally known method. For example, it can be produced by reacting a bifunctional phenol compound having the structure represented by the above formula (2) (sometimes referred to as "bifunctional phenol compound (a)") with epihalohydrin in the presence of an alkali metal compound (hereinafter referred to as "one-step method"). It can also be produced by reacting at least one of a bifunctional epoxy resin and a bifunctional phenol compound with a bifunctional epoxy resin having the structure represented by the above formula (2) and a bifunctional phenol compound in the presence of a catalyst (hereinafter referred to as "two-step method"). Epoxy resin (a) can be obtained by either method.

[0068] The weight average molecular weight and epoxy equivalent of the epoxy resin (a) can be produced within the desired range by appropriately adjusting the molar ratio of the epihalohydrin and the bifunctional phenol compound charged in the one-stage process, or by appropriately adjusting the molar ratio of the bifunctional epoxy resin and the bifunctional phenol compound charged in the two-stage process.

[0069] Examples of the bifunctional phenol compound (a) used in the production of the one-step method and the two-step method include phenolphthalein and phenolphthalein anilide containing a divalent group represented by the above formula (2).

[0070] Other bifunctional phenol compounds may be used in combination as long as the object of the present invention is not impaired. Examples of bifunctional phenol compounds that may be used in combination include bisphenols such as bisphenol A, bisphenol F, bisphenol S, bisphenol B, bisphenol E, bisphenol C, bisphenolacetophenone, bisphenolfluorene, dihydroxybiphenyl ether, and dihydroxybiphenyl thioether, biphenols such as 4,4'-biphenol and 2,4'-biphenol, dihydroxynaphthalene, hydroquinone, catechol, resorcinol, 1,1-bi-2-naphthol, 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-HQ), and 10-(2,7-dihydroxynaphthyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-NQ). In addition, a plurality of types of these bifunctional phenol compounds may be used in combination.

[0071] First, the one-stage method will be described. In the one-step process, a bifunctional phenol compound and an epihalohydrin are reacted in a non-reactive solvent in the presence of an alkali metal compound, and the epihalohydrin is consumed to undergo a condensation reaction, thereby obtaining the epoxy resin (a). After completion of the reaction, the by-product salt must be removed by filtration or washing with water. Examples of the alkali metal compound include the same alkali metal compounds as those used in the production of the bifunctional epoxy resin represented by formula (3) used in production method (A) of the present invention. The weight average molecular weight and epoxy equivalent of the epoxy resin (a) can be adjusted to fall within the desired range by appropriately adjusting the molar ratio of the bifunctional phenol compound and epihalohydrin charged. For example, when the weight average molecular weight of the epoxy resin (a) is set to 10,000 or more, the amount of epihalohydrin is adjusted to 0.985 to 1.015 mol, preferably 0.99 to 1.012 mol, more preferably 0.995 to 1.01 mol, per 1 mol of the bifunctional phenol compound. When the epoxy equivalent of the epoxy resin (a) is set to 5,000 g / eq or less, the amount of epihalohydrin is adjusted to 1.015 to 8 mol, preferably 1.05 to 6 mol, more preferably 1.1 to 5 mol, per 1 mol of the bifunctional phenol compound.

[0072] The molar amount of the bifunctional phenol compound (a) used as a raw material is preferably 1 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and particularly preferably 40 mol% or more, based on the total amount of the bifunctional phenol compounds. If the amount is outside this range, the heat resistance of the modified epoxy resin of the present invention may be deteriorated.

[0073] This reaction can be carried out under normal pressure or under reduced pressure. The reaction temperature is preferably 20 to 200°C, more preferably 30 to 170°C, even more preferably 40 to 150°C, and particularly preferably 50 to 100°C, when carried out under normal pressure. The reaction temperature is preferably 20 to 100°C, more preferably 30 to 90°C, and even more preferably 35 to 80°C, when carried out under reduced pressure. A reaction temperature within this range makes it difficult for side reactions to occur and facilitates the reaction to proceed. The reaction pressure is usually normal pressure. Furthermore, when heat of reaction needs to be removed, this is usually achieved by evaporation, condensation, and reflux of the solvent used, indirect cooling, or a combination of these.

[0074] As the reactive solvent, in addition to the reaction solvents exemplified in the production method (A) of the present invention, alcohols such as ethanol, isopropyl alcohol, butyl alcohol, etc. may be used. Only one type may be used, or two or more types may be used in combination.

[0075] Next, the two-stage method will be described. As the bifunctional epoxy resin serving as the starting epoxy resin in the two-stage process, the same bifunctional epoxy resin as that represented by the above formula (3) used in the production method (A) of the present invention is used.

[0076] The bifunctional epoxy resin used as the raw material for the two-stage process is preferably the bifunctional epoxy resin represented by the above formula (3), but other bifunctional epoxy resins may be used in combination as long as the objectives of the present invention are not impaired. Examples of bifunctional epoxy resins that can be used in combination include bisphenol-type epoxy resins such as bisphenol A-type epoxy resins, bisphenol F-type epoxy resins, bisphenol S-type epoxy resins, bisphenolacetophenone-type epoxy resins, diphenyl sulfide-type epoxy resins, and diphenyl ether-type epoxy resins, biphenol-type epoxy resins, diphenyldicyclopentadiene-type epoxy resins, alkylene glycol-type epoxy resins, and aliphatic cyclic epoxy resins. These epoxy resins may be substituted with non-detrimental substituents such as alkyl groups and aryl groups. Multiple types of these epoxy resins may be used in combination.

[0077] In the two-stage process, a catalyst can be used, and any compound having catalytic activity that promotes the reaction between the epoxy group and the phenolic hydroxyl group can be used. Examples include the same catalysts as those exemplified in Production Method (A) of the present invention. The alkali metal compounds used in the production of the bifunctional epoxy resin represented by formula (3) above can also be used. These catalysts may be used alone or in combination of two or more. The amount used is also the same as that exemplified in Production Method (A) of the present invention.

[0078] In the two-stage process, a solvent may be used. Any solvent may be used as long as it dissolves the epoxy resin and does not adversely affect the reaction. For example, the same solvents as those exemplified in the production method (A) of the present invention may be used. These solvents may be used alone or in combination of two or more.

[0079] The amount of solvent used can be appropriately selected depending on the reaction conditions. For example, in the case of a two-stage process, a solids concentration of 35 to 95% by mass is preferred. If a highly viscous product is produced during the reaction, the reaction can be continued by adding solvent during the reaction. After the reaction is complete, the solvent can be removed by distillation or the like, or more solvent can be added, as necessary.

[0080] The reaction temperature is maintained within a range that does not decompose the catalyst used. If the reaction temperature is too high, the catalyst may decompose, halting the reaction or degrading the resulting epoxy resin. If the reaction temperature is too low, the reaction may not proceed sufficiently to achieve the desired molecular weight. Therefore, the reaction temperature is preferably 50 to 230°C, more preferably 100 to 210°C, and even more preferably 120 to 200°C. The reaction time is typically 1 to 12 hours, with 3 to 10 hours being preferred. When using low-boiling solvents such as acetone or methyl ethyl ketone, the reaction temperature can be maintained by conducting the reaction under high pressure using an autoclave. If the heat of reaction needs to be removed, this is typically accomplished by evaporation, condensation, and reflux of the solvent using the reaction heat, indirect cooling, or a combination of these.

[0081] The modified epoxy resin of the present invention can be obtained by acylation of the hydroxyl groups in the epoxy resin (a) represented by the above formula (5) obtained in this manner. Acylation can be carried out by direct esterification or by a method such as transesterification.

[0082] Examples of the acid component used in the acylation include organic acids such as acetic acid, propionic acid, butyric acid, isobutyric acid, pentanoic acid, octanoic acid, caprylic acid, lauric acid, stearic acid, oleic acid, benzoic acid, t-butylbenzoic acid, hexahydrobenzoic acid, phenoxyacetic acid, acrylic acid, and methacrylic acid, as well as acid anhydrides of organic acids, halides of organic acids, and esters of organic acids.

[0083] Examples of the acid anhydrides of organic acids include acetic anhydride, benzoic anhydride, and phenoxyacetic anhydride. Examples of organic acid esters include methyl acetate, ethyl acetate, butyl acetate, methyl benzoate, ethyl benzoate, etc. Examples of organic acid halides include acetic acid chloride, benzoic acid chloride, phenoxyacetic acid chloride, etc.

[0084] The compound used for esterification is preferably an organic acid halide such as acetic acid chloride, benzoic acid chloride, or phenoxyacetic acid chloride, or an acid halide or an organic acid anhydride such as acetic anhydride, benzoic acid anhydride, or phenoxyacetic acid anhydride, and more preferably an acid anhydride such as acetic anhydride or benzoic acid anhydride, since this does not require washing with water after esterification and avoids contamination with halogens, which are undesirable in electrical materials applications.

[0085] The charge ratio of the acid component such as the organic acid, acid anhydride of an organic acid, halide of an organic acid, or ester of an organic acid used for esterifying the hydroxyl groups of the epoxy resin (a) when reacting with the epoxy resin (a) may be the same as the target esterification ratio, or when the reactivity is low, the acid component may be charged in excess relative to the hydroxyl groups, and after the reaction has been carried out until the target esterification ratio is reached, the unreacted acid component may be removed.

[0086] Direct esterification with an acid component can be carried out while dehydrating using various esterification catalysts, such as acid catalysts (e.g., paratoluenesulfonic acid, phosphoric acid, etc.) or metal catalysts (e.g., tetraisopropyl titanate, tetrabutyl titanate, dibutyltin oxide, dioctyltin oxide, zinc chloride, etc.) It is usually carried out in a nitrogen atmosphere at 100 to 250°C, more preferably 130 to 230°C.

[0087] When an acid halide or an acid anhydride is used for esterification, the generated acid can be removed by any of the following methods, or a combination of these: a method of neutralizing with a basic compound and then filtering the salt; a method of neutralizing with a basic compound and then washing with water; a method of washing with water without neutralization; or a method of removing the acid by distillation or adsorption. When an acid having a boiling point lower than that of the reaction solvent is to be removed, it is preferable to remove it by distillation.

[0088] When the epoxy resin (a) is esterified by transesterification, it is generally desirable to carry out the esterification under a nitrogen atmosphere while dealcoholizing the resin using a known esterification catalyst, for example, an organometallic catalyst such as dibutyltin oxide, dioctyltin oxide, a stannoxane catalyst, tetraisopropyl titanate, tetrabutyl titanate, lead acetate, zinc acetate, or antimony trioxide; an acid catalyst such as hydrochloric acid, sulfuric acid, phosphoric acid, or sulfonic acid; or a basic catalyst such as lithium hydroxide or sodium hydroxide.

[0089] In the production method (B) of the present invention, a reaction solvent may be used, and any solvent that dissolves the epoxy resin may be used. Examples include the solvents exemplified in the production method (A) of the present invention. These solvents may be the same as or different from those used in preparing the epoxy resin (a). Furthermore, only one solvent may be used, or two or more solvents may be used in combination. The solid content concentration during the reaction is also the same as in the production method (A), and is preferably 35 to 95 mass%, more preferably 50 to 90 mass%, and even more preferably 70 to 90 mass%.

[0090] The resin composition of the present invention is a resin composition containing at least the modified epoxy resin of the present invention and a curing agent. Furthermore, various additives such as epoxy resins, inorganic fillers, coupling agents, and antioxidants can be appropriately blended into the resin composition of the present invention as needed. The resin composition of the present invention provides a cured product that satisfies the various physical properties required for various applications.

[0091] A resin composition can be prepared by blending a curing agent with the modified epoxy resin of the present invention. In the present invention, the curing agent refers to a substance that contributes to the crosslinking reaction and / or chain extension reaction with the modified epoxy resin. In the present invention, even substances that are normally called "curing accelerators" are considered to be curing agents as long as they contribute to the crosslinking reaction and / or chain extension reaction of the modified epoxy resin.

[0092] The content of the curing agent in the resin composition of the present invention is preferably 0.1 to 100 parts by mass in terms of solid content, more preferably 80 parts by mass or less, and even more preferably 60 parts by mass or less, per 100 parts by mass of the solid content of the modified epoxy resin of the present invention.

[0093] When the resin composition of the present invention contains other epoxy resins described below, the weight ratio of the solid content of the modified epoxy resin of the present invention to the other epoxy resins is 99 / 1 to 1 / 99. In the present invention, "solid content" refers to the components excluding the solvent, and includes not only solid modified epoxy resins and other epoxy resins, but also semi-solid and viscous liquids. Furthermore, "resin component" refers to the total of the modified epoxy resin of the present invention and the other epoxy resins described below.

[0094] The curing agent used in the resin composition of the present invention is not particularly limited, and any commonly known curing agent for epoxy resins can be used. From the viewpoint of improving heat resistance, preferred curing agents include phenol-based curing agents, amide-based curing agents, imidazoles, and active ester-based curing agents. These curing agents may be used alone or in combination of two or more.

[0095] Examples of phenolic curing agents include bisphenol A, bisphenol F, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 1,4-bis(4-hydroxyphenoxy)benzene, 1,3-bis(4-hydroxyphenoxy)benzene, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxybiphenyl, 2,2'-dihydroxybiphenyl, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, phenol novolac, bisphenol A novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolac, poly-p-hydroxystyrene, hydroquinone, resorcinol, catechol, t-butylcatechol, t-butylhydroquinone, fluoroglycinol, pyrogallol, t-butylpyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, Examples of the allylated phenol include 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated products or polyallylated products of the above dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, and allylated pyrogallol.

[0096] Examples of the amide-based curing agent include dicyandiamide and its derivatives, polyamide resins, and the like.

[0097] Examples of imidazoles include 2-phenylimidazole, 2-ethyl-4(5)methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl Examples of suitable imidazoles include 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins with the above imidazoles. Note that, since imidazoles have catalytic activity, they can generally be classified as curing accelerators, which will be described later, but in the present invention they are classified as curing agents.

[0098] Examples of active ester curing agents include compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. Among these, phenol esters obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group are more preferred. Specific examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. Examples of aromatic compounds having a phenolic hydroxyl group include catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, dicyclopentadienyldiphenol, and phenol novolac.

[0099] Examples of other curing agents that can be used in the resin composition of the present invention include amine-based curing agents, acid anhydride-based curing agents, tertiary amines, organic phosphines, phosphonium salts, tetraphenylboron salts, organic acid dihydrazides, boron halide amine complexes, polymercaptan-based curing agents, isocyanate-based curing agents, blocked isocyanate-based curing agents, carbodiimide compounds, etc. These other curing agents may be used alone, or two or more may be mixed in any combination and ratio.

[0100] The resin composition of the present invention can contain epoxy resins other than the modified epoxy resin of the present invention. The use of other epoxy resins can compensate for insufficient physical properties or improve various physical properties. The epoxy resin preferably has two or more epoxy groups in the molecule, and more preferably has three or more epoxy groups. Examples include polyglycidyl ether compounds, polyglycidyl amine compounds, polyglycidyl ester compounds, alicyclic epoxy compounds, and other modified epoxy resins. These epoxy resins may be used alone, or two or more types of epoxy resins of the same type may be used in combination, or different types of epoxy resins may be used in combination.

[0101] Examples of the polyglycidyl ether compound include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, bisphenol Z type epoxy resins, bisphenol fluorene type epoxy resins, diphenyl sulfide type epoxy resins, diphenyl ether type epoxy resins, naphthalene type epoxy resins, hydroquinone type epoxy resins, resorcinol type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, alkyl novolac type epoxy resins, styrenated phenol novolac type epoxy resins, bisphenol novolac type epoxy resins, naphthol novolac type epoxy resins, phenol aralkyl type epoxy resins, β-naphthol aralkyl type epoxy resins, naphthalenediol aralkyl type epoxy resins, α-naphthol aralkyl type epoxy resins, biphenyl aralkyl phenol type epoxy resins, biphenyl type epoxy resins, triphenylmethane type epoxy resins, dicyclopentadiene type epoxy resins, alkylene glycol type epoxy resins, and various epoxy resins such as aliphatic cyclic epoxy resins.

[0102] Examples of polyglycidylamine compounds include diaminodiphenylmethane type epoxy resins, metaxylenediamine type epoxy resins, 1,3-bisaminomethylcyclohexane type epoxy resins, isocyanurate type epoxy resins, aniline type epoxy resins, hydantoin type epoxy resins, and aminophenol type epoxy resins.

[0103] Examples of polyglycidyl ester compounds include dimer acid type epoxy resins, hexahydrophthalic acid type epoxy resins, and trimellitic acid type epoxy resins.

[0104] Examples of the alicyclic epoxy compound include aliphatic cyclic epoxy resins such as CELLOXIDE 2021 (manufactured by Daicel Chemical Industries, Ltd.).

[0105] Other modified epoxy resins include, for example, urethane-modified epoxy resins, oxazolidone ring-containing epoxy resins, epoxy-modified polybutadiene rubber derivatives, carboxyl-terminated butadiene nitrile rubber (CTBN)-modified epoxy resins, polyvinylarene polyoxides (e.g., divinylbenzene dioxide, trivinylnaphthalene trioxide, etc.), and phenoxy resins.

[0106] When the modified epoxy resin of the present invention and another epoxy resin are used in the resin composition of the present invention, the amount of the modified epoxy resin in the total epoxy resin components and the modified epoxy resin as solids is preferably 1 to 99 mass %, more preferably 50 mass % or more, and even more preferably 80 mass % or more.

[0107] The resin composition of the present invention may contain a solvent or reactive diluent to adjust the viscosity of the resin composition appropriately when handling the composition to form a coating film. In the resin composition of the present invention, the solvent or reactive diluent is used to ensure the ease of handling and workability when molding the resin composition, and there is no particular limit to the amount used. In the present invention, the term "solvent" and the aforementioned term "solvent" are used separately depending on the form of use, but the same or different substances may be used independently.

[0108] Examples of solvents that may be contained in the resin composition of the present invention include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, cyclohexanone, etc., esters such as ethyl acetate, ethers such as ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide, N,N-dimethylacetamide, etc., alcohols such as methanol, ethanol, etc., alkanes such as hexane, cyclohexane, etc., aromatics such as toluene, xylene, etc. The above-mentioned solvents may be used alone, or two or more may be mixed in any combination and ratio.

[0109] Examples of reactive diluents include monofunctional glycidyl ethers such as allyl glycidyl ether, bifunctional glycidyl ethers such as propylene glycol diglycidyl ether, polyfunctional glycidyl ethers such as trimethylolpropane polyglycidyl ether, glycidyl esters, and glycidyl amines.

[0110] These solvents or reactive diluents are preferably used in an amount of 90% by mass or less as nonvolatile matter, and the appropriate type and amount are appropriately selected depending on the application. For example, for printed wiring 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 as nonvolatile matter. For 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 as nonvolatile matter.

[0111] The resin composition of the present invention may contain a curing accelerator or catalyst as needed. Examples of the curing accelerator or catalyst include imidazoles, tertiary amines, phosphorus compounds such as phosphines, metal compounds, Lewis acids, and amine complex salts. These may be used alone or in combination of two or more.

[0112] The amount of curing accelerator or catalyst used may be selected appropriately depending on the intended use, but is preferably 0.01 to 15 parts by mass per 100 parts by mass of the epoxy resin component in the resin composition. It is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, even more preferably 0.1 to 5 parts by mass, and particularly preferably 0.1 to 1.0 part by mass. The use of a curing accelerator or catalyst can lower the curing temperature and shorten the curing time.

[0113] In order to improve the flame retardancy of the resulting cured product, various known flame retardants can be used in the resin composition of the present invention, as long as the reliability is not reduced. Usable flame retardants include, for example, halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organic metal salt-based flame retardants. From an environmental perspective, halogen-free flame retardants are preferred, and phosphorus-based flame retardants are particularly preferred. These flame retardants may be used alone, or two or more of the same type of flame retardants may be used in combination, or different types of flame retardants may be used in combination.

[0114] The resin composition of the present invention may contain components other than those listed above (sometimes referred to as "other components" in the present invention) for the purpose of further improving its functionality. Examples of such other components include fillers, thermoplastic resins, thermosetting resins, photocurable resins, ultraviolet inhibitors, antioxidants, coupling agents, plasticizers, fluxes, thixotropic agents, smoothing agents, colorants, pigments, dispersants, emulsifiers, elasticity reducing agents, release agents, antifoaming agents, and ion trapping agents.

[0115] Examples of fillers include inorganic fillers such as fused silica, crystalline silica, alumina, silicon nitride, boron nitride, aluminum nitride, aluminum hydroxide, calcium hydroxide, magnesium hydroxide, boehmite, talc, mica, clay, calcium carbonate, magnesium carbonate, barium carbonate, zinc oxide, titanium oxide, magnesium oxide, magnesium silicate, calcium silicate, zirconium silicate, barium sulfate, and carbon; fibrous fillers such as carbon fiber, glass fiber, alumina fiber, silica alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aramid fiber, and ceramic fiber; and fine particle rubber.

[0116] The resin composition of the present invention may contain a thermoplastic resin other than the modified epoxy resin of the present invention. Examples of thermoplastic resins include modified epoxy resins other than those of the present invention, phenoxy resins, polyurethane resins, polyester resins, polyethylene resins, polypropylene resins, polystyrene resins, ABS resins, AS resins, vinyl chloride resins, polyvinyl acetate resins, polymethyl methacrylate resins, polycarbonate resins, polyacetal resins, cyclic polyolefin resins, polyamide resins, thermoplastic polyimide resins, polyamideimide resins, polytetrafluoroethylene resins, polyetherimide resins, polyphenylene ether resins, modified polyphenylene ether resins, polyethersulfone resins, polysulfone resins, polyetheretherketone resins, polyphenylene sulfide resins, and polyvinyl formal resins. In terms of compatibility, modified epoxy resins and phenoxy resins other than those of the present invention are preferred, and polyphenylene ether resins and modified polyphenylene ether resins are preferred in terms of low dielectric properties.

[0117] Examples of other components include organic pigments such as quinacridone, azo, and phthalocyanine pigments, inorganic pigments such as titanium oxide, metal foil pigments, and anti-rust pigments, ultraviolet absorbers such as hindered amine, benzotriazole, and benzophenone, antioxidants such as hindered phenol, phosphorus, sulfur, and hydrazide, release agents such as stearic acid, palmitic acid, zinc stearate, and calcium stearate, and additives such as leveling agents, rheology control agents, pigment dispersants, anti-cracking agents, and anti-foaming agents. The amount of these other components added is preferably 0.01 to 20% by mass based on the total solid content of the resin composition.

[0118] The resin composition of the present invention can be obtained by uniformly mixing the above-mentioned components. Resin compositions containing modified epoxy resins, curing agents, and other optional components can be easily cured using methods similar to those known in the art. These cured products exhibit excellent balance of low moisture absorption, dielectric properties, heat resistance, adhesion, and other properties, and exhibit favorable cured physical properties. "Curing" here refers to intentionally curing the resin composition using heat and / or light, and the degree of curing can be controlled depending on the desired physical properties and application. The degree of curing may be fully cured or semi-cured, and is not particularly limited; however, the reaction rate of the curing reaction between the epoxy groups and the curing agent is typically 5 to 95%.

[0119] The resin composition of the present invention can be cured to obtain a cured product by the same method as for known epoxy resin compositions. Methods for obtaining a cured product include those similar to those for known epoxy resin compositions, such as casting, injection, potting, dipping, drip coating, transfer molding, and compression molding, as well as laminating the resin in the form of a resin sheet, resin-coated copper foil, or prepreg, followed by heating and pressure curing to obtain a laminate. The curing temperature is typically in the range of 80 to 300°C, and the curing time is typically about 10 to 360 minutes. This heating is preferably carried out in two stages: a primary heating step at 80 to 180°C for 10 to 90 minutes, followed by a secondary heating step at 120 to 200°C for 60 to 150 minutes. Furthermore, for formulations whose glass transition temperature (Tg) exceeds the secondary heating temperature, a tertiary heating step at 150 to 280°C for 60 to 120 minutes is preferably carried out. Such secondary and tertiary heating steps can reduce poor curing. When producing a semi-cured resin product such as a resin sheet, a resin-coated copper foil, or a prepreg, the curing reaction of the resin composition is usually allowed to proceed to an extent that the shape can be maintained by heating, etc. When the resin composition contains a solvent, most of the solvent is usually removed by techniques such as heating, decompression, or air drying, but 5% by mass or less of the solvent may remain in the semi-cured resin product.

[0120] The prepreg obtained using the resin composition of the present invention will now be described. The sheet-like substrate can be, but is not limited to, a woven or nonwoven fabric made of inorganic fibers such as glass, or organic fibers such as polyester, polyamine, polyacrylic, polyimide, Kevlar, or cellulose. The method for producing a prepreg from the resin composition of the present invention and the substrate is not particularly limited. For example, the substrate can be immersed in a resin varnish obtained by adjusting the viscosity of the resin composition with a solvent, and then heated and dried to semi-cure (B-stage) the resin component. For example, the prepreg can be obtained by heating and drying at 100 to 200°C for 1 to 40 minutes. Here, the amount of resin in the prepreg is preferably 30 to 80% by mass.

[0121] This section explains a method for manufacturing a laminate using prepreg or an insulating adhesive sheet. When forming a laminate using prepreg, one or more prepreg sheets are laminated together, and metal foil is placed on one or both sides to form a laminate, which is then heated and pressed to form an integrated laminate. The metal foil used here can be a single, alloy, or composite metal foil of copper, aluminum, brass, nickel, or the like. The conditions for heating and pressing the laminate can be appropriately adjusted to cure the resin composition. However, if the pressure is too low, air bubbles may remain inside the resulting laminate, resulting in reduced electrical properties. Therefore, it is desirable to pressurize under conditions that satisfy moldability. For example, a temperature of 160 to 220°C and a pressure of 49 to 490 N / cm are preferable. 2 (5-50kgf / cm 2 ) and heating time can be set from 40 to 240 minutes.

[0122] Furthermore, a multilayer board can be produced using the single-layer laminate thus obtained as an inner layer material. In this case, a circuit is first formed on the laminate by an additive method, a subtractive method, or the like, and the surface of the formed circuit is then treated with an acid solution for blackening to obtain an inner layer material. An insulating layer is formed on one or both circuit-forming surfaces of this inner layer material using a prepreg or an insulating adhesive sheet, and a conductor layer is formed on the surface of the insulating layer to form a multilayer board.

[0123] When forming an insulating layer using an insulating adhesive sheet, a laminate is formed by placing an insulating adhesive sheet on the circuit-forming surfaces of multiple inner layer materials. Alternatively, a laminate is formed by placing an insulating adhesive sheet between the circuit-forming surfaces of the inner layer materials and metal foil. This laminate is then heated and pressurized to form an integral molding, thereby forming the cured insulating adhesive sheet as an insulating layer and forming a multilayer inner layer material. Alternatively, the inner layer material and the metal foil serving as the conductor layer are combined to form the cured insulating adhesive sheet as an insulating layer. Here, the metal foil can be the same as that used in the laminate used as the inner layer material. Furthermore, the hot and pressure molding can be carried out under the same conditions as those for molding the inner layer material. When forming an insulating layer by applying a resin composition to a laminate, the resin for forming the circuit on the outermost layer of the inner layer material is preferably applied to a thickness of 5 to 100 μm with the above-mentioned resin composition, and then heated and dried at 100 to 200°C for 1 to 90 minutes to form a sheet. This is generally formed by a method called a casting method. The thickness after drying is preferably formed to 5 to 80 μm. A printed wiring board can be formed by further forming via holes and circuits on the surface of the multilayer laminate thus formed by an additive method or a subtractive method. Furthermore, by repeating the above process using this printed wiring board as an inner layer material, it is possible to form a multi-layer laminate.

[0124] When forming an insulating layer using prepreg, one or more prepreg sheets are placed on the circuit-forming surface of the inner layer material, and a metal foil is placed on the outside of the prepreg to form a laminate. This laminate is then heated and pressurized to form an integral molding, whereby the cured prepreg is formed as an insulating layer and the outer metal foil is formed as a conductor layer. Here, the metal foil may be the same as that used in the laminate used as the inner layer material. The hot-press molding can be carried out under the same conditions as those for molding the inner layer material. The surface of the multilayer laminate thus molded can be further subjected to via hole formation and circuit formation by an additive method or a subtractive method to mold a printed wiring board. Furthermore, by repeating the above process using this printed wiring board as an inner layer material, it is possible to form a multi-layer board with even more layers.

[0125] The cured product and laminate for electric / electronic circuits obtained from the resin composition of the present invention have excellent dielectric properties and heat resistance. [Example]

[0126] The present invention will be explained in more detail below based on examples and comparative examples, but the present invention is not limited thereto. Unless otherwise specified, parts represent "parts by mass" and % represents "% by mass." Analytical and measurement methods are shown below. Furthermore, the unit of various equivalents is "g / eq."

[0127] (1) Weight average molecular weight (Mw) and number average molecular weight (Mn): The solubility was determined by GPC measurement. Specifically, a Tosoh HLC8320 GPC main body equipped with columns (TSKgel SuperH-H, SuperH2000, SuperHM-H, SuperHM-H, all Tosoh) 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 1.0 mL / min, and a refractive index detector was used. 0.1 g of solids were dissolved in 10 mL of THF and filtered through a 0.45 μm microfilter, resulting in 50 μL of the sample. Data processing was performed using a Tosoh GPC8020 Model II version 6.00.

[0128] (2) IR (infrared absorption spectrum): A Fourier transform infrared spectrophotometer (Perkin Elmer Precisely, Spectrum One FT-IR Spectrometer 1760X) was used, and the cell was filled with sodium chloride. The sample dissolved in chloroform was applied to the cell, dried, and then measured at a wavenumber of 400 to 4000 cm. -1 The transmittance was measured.

[0129] (3) Epoxy equivalent: Measurements were carried out in accordance with JIS K 7236. Specifically, a potentiometric titrator was used, cyclohexanone was used as the solvent, tetraethylammonium bromide acetate solution was added, and a 0.1 mol / L perchloric acid-acetic acid solution was used. For solvent-diluted products (resin varnishes), the solid content was calculated from the nonvolatile content.

[0130] (4) Nonvolatile content: Measurement was performed in accordance with JIS K 7235. The drying temperature was 200°C and the drying time was 60 minutes.

[0131] (5) Solvent solubility: The modified epoxy resin was dissolved in methyl ethyl ketone (MEK) to prepare a resin varnish with a resin content of 40%, which was then kept in a thermostatic chamber at 25°C for 24 hours, after which the state was visually judged. Clear: ○, Cloudy: △, Separation: ×

[0132] (6) Resin compatibility: The modified epoxy resin was mixed with A1, a bisphenol A liquid epoxy resin, under heat, and then the mixture was left in a thermostatic chamber at 25°C for 24 hours, after which the state was visually inspected. The mixture was made in a ratio of modified epoxy resin / A1 = 50 / 50 (mass ratio). Clear: ○, Cloudy: △, Separation: ×

[0133] (7) Glass transition temperature (Tg): Measurements were performed in accordance with IPC-TM-650 2.4.25.c. Specifically, a 4 mm thick, 3 mm diameter sample was measured using a differential scanning calorimeter (EXSTAR6000 DSC6200, manufactured by SII NanoTechnology Inc.) in the range of 20 to 280°C at a temperature increase rate of 10°C / min for two cycles, and the glass transition temperature (Tmg) was expressed as the midpoint of the second scan measurement chart.

[0134] (8) Dielectric properties: The film-shaped sample was measured using the cavity resonator perturbation method, and the plate-shaped sample was measured using the capacitance method. The dielectric loss tangents of Examples 14 to 19 and Comparative Examples 4 and 5 were evaluated by measuring at 1 GHz using a cavity resonator perturbation method. Specifically, measurements were performed using a PNA network analyzer N5230A (manufactured by Agilent Technologies) and a cavity resonator CP431 (manufactured by Kanto Electronics Application Development Co., Ltd.) in a measurement environment of room temperature 23°C and humidity 50% RH, using test pieces with a width of 1.5 mm, length of 80 mm, and thickness of 150 μm. The dielectric loss tangents of Examples 20 and 21 and Comparative Examples 6 and 7 were evaluated by measuring them at 1 GHz by a capacitance method. Specifically, the measurements were carried out in accordance with the IPC-TM-650 2.5.5.9 standard using a material analyzer (manufactured by Agilent Technologies) under a measurement environment of room temperature of 23°C and humidity of 50% RH using test pieces of 30 mm square and 1 mm thick.

[0135] (9) Film formability: A film was prepared from the modified epoxy resin and a cured product thereof, and the obtained film was bent 180 degrees and evaluated based on the number of times it could be bent. 10 or more times: ○, 1 to 9 times: △, 0 times: ×

[0136] The abbreviations used in the examples and comparative examples are as follows:

[0137] [Bifunctional epoxy resin] A1: Bisphenol A liquid epoxy resin (Nippon Steel Chemical & Material Co., Ltd., YD-128, epoxy equivalent 186, m≒0.11) A2: Fluorene-type epoxy resin (manufactured by Nippon Steel Chemical & Material Co., Ltd., ESF-300, epoxy equivalent 250, softening point 87°C, m≒0.09) A3: Biphenyl-type epoxy resin (Mitsubishi Chemical Corporation, YX-4000, epoxy equivalent 196, melting point 105°C, m≒0.13) A4: Naphthalene-type liquid epoxy resin (DIC Corporation, Epicron HP4032D, epoxy equivalent 142, m≒0.06) A5: Bisphenol A solid epoxy resin (Nippon Steel Chemical & Material Co., Ltd., YD-901, epoxy equivalent 410, m≒1.7) A6: Bisphenol A solid epoxy resin (Nippon Steel Chemical & Material Co., Ltd., YD-7910, epoxy equivalent 2500, m≒16) Here, m has the same meaning as m in the above formula (3).

[0138] [Diester compounds] B1: Diacetoxyphenolphthalein (active equivalent = 201) obtained in Synthesis Example 1 B2: Diacetoxyphenolphthalein anilide (active equivalent = 261) obtained in Synthesis Example 2 B3: 4,4'-diacetoxybiphenyl (Tokyo Chemical Industry Co., Ltd., active equivalent weight = 135)

[0139] [Bifunctional phenolic compounds] C1: Phenolphthalein (Fujifilm Wako Pure Chemical Industries, Ltd., hydroxyl equivalent: 159) C2: Phenolphthalein anilide (manufactured by Yamanishi Ryusei Pharmaceutical Co., Ltd., hydroxyl equivalent weight 219) C3: 4,4'-dihydroxybiphenyl (Tokyo Chemical Industry Co., Ltd., hydroxyl equivalent: 93)

[0140] [catalyst] D1: N,N'-dimethylaminopyridine (Tokyo Chemical Industry Co., Ltd.) D2: 2-ethyl-4-methylimidazole (Curesol 2E4MZ, manufactured by Shikoku Chemicals Corporation)

[0141] [Solvents] S1: Cyclohexanone S2: Methyl ethyl ketone (MEK)

[0142] [Acid anhydride] E1: Acetic anhydride (Fujifilm Wako Pure Chemical Industries, Ltd.) E2: Benzoic anhydride (Tokyo Chemical Industry Co., Ltd.)

[0143] [Hardening agent] H1: Phenol novolac resin (manufactured by Aica Kogyo Co., Ltd., Shounol BRG-557, hydroxyl group equivalent: 105)

[0144] Synthesis Example 1 A glass reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet, condenser, and dropping device was charged with 100 parts of bifunctional phenol compound C1, 64 parts of acid anhydride E1, and 50 parts of pyridine at room temperature, and the mixture was heated to 60°C while stirring under nitrogen gas flow, and reacted for 2 hours. Thereafter, the mixture was dried under reduced pressure at 150°C and 1.3 kPa (10 torr) for 2 hours, yielding 126 parts of diester compound B1.

[0145] Synthesis Example 2 A glass reaction vessel equipped with a stirrer, thermometer, nitrogen gas inlet, condenser, and dropping device was charged with 100 parts of bifunctional phenol compound C2, 47 parts of acid anhydride E1, and 36 parts of pyridine at room temperature, and the mixture was heated to 60°C while stirring under nitrogen gas flow, and reacted for 2 hours. Thereafter, the mixture was dried under reduced pressure at 150°C and 1.3 kPa (10 torr) for 2 hours, yielding 119 parts of diester compound B2.

[0146] Example 1 A glass reactor equipped with a stirrer, thermometer, nitrogen gas inlet, condenser, and dropping device was charged with 100 parts of bifunctional epoxy resin A1, 103 parts of diester compound B1, and 51 parts of reaction solvent S1 at room temperature. The mixture was heated to 130°C while stirring under a nitrogen gas stream, and 0.2 parts of catalyst D1 was added. The mixture was then heated to 145°C and reacted at the same temperature for 7 hours. The mixture was diluted and mixed with 51 parts of dilution solvent S1 and 203 parts of S2 to obtain a modified epoxy resin varnish (R1) with a non-volatile content of 40%.

[0147] Examples 2 to 11, Comparative Examples 1 to 3 A resin varnish was obtained in the same manner as in Example 1, using the amounts (parts) of each raw material shown in Table 1. The "molar ratio" in the table indicates the molar ratio of the difunctional epoxy resin to the diester compound and the difunctional phenol compound.

[0148] [Table 1]

[0149] Example 12 100 parts (40 parts solids) of the resin varnish (HR3) obtained in Comparative Example 3 and 600 parts of reaction solvent S1 were blended, and the mixture was heated to 100°C. Five parts of acid anhydride E1 were added and reacted for four hours. The resulting resin varnish was added to methanol, and the precipitated insoluble matter was filtered off. The filtrate was then dried in a vacuum dryer at 150°C and 0.4 kPa (3 torr) for one hour to obtain a modified epoxy resin. 20 parts of dilution solvent S1 and 41 parts of S2 were added to the resulting modified epoxy resin, and the mixture was dissolved uniformly to obtain a resin varnish (R12) with a nonvolatile content of 40%.

[0150] Example 13 A resin varnish (R13) was obtained in the same manner as in Example 11, except that the amount of acid anhydride E1 was 24 parts, the amount of dilution solvent S1 was 22 parts, and the amount of S2 was 44 parts.

[0151] Example 14 A resin varnish (R14) was obtained in the same manner as in Example 11, except that 52 parts of E2 were used instead of acid anhydride E1, 25 parts of dilution solution S1, and 52 parts of S2 were used.

[0152] The resin varnishes R1 to R14 and HR1 to HR3 obtained in Examples 1 to 14 and Comparative Examples 1 to 3 were applied to an iron plate so that the film thickness after drying would be 100 μm, and then dried in a dryer at 150° C. for 1 hour to obtain a resin film. The epoxy equivalent and Mw of the resin varnish were measured, and the solvent solubility, resin compatibility, and film-forming properties (excluding low-molecular-weight epoxies) of the resin film were measured. The results are shown in Table 2. In the table, "acylation rate" indicates the content (mol%) of acyl groups in all Z, "formula (2) rate" indicates the content (mol%) of divalent groups represented by formula (2) in all X, and "-" indicates not measured. The examples using resin varnishes HR1 to HR3 are comparative examples.

[0153] [Table 2]

[0154] Examples 15 to 20, Comparative Examples 4 and 5 A resin composition was prepared by blending 30 parts (12 parts solids) of the modified epoxy resin varnishes (R1-R5, R13, HR1-HR2) obtained in Examples 1-5 and 13 and Comparative Examples 1-2 with 2 parts of another epoxy resin A1, 2.5 parts of a 50% MEK solution of curing agent H1, and 0.6 parts of a 20% MEK solution of curing accelerator D2. These compositions were then applied to steel plates to dry to thicknesses of 100 μm and 150 μm, and dried in a dryer at 150°C for 1 hour to obtain cured polymer films. The Tg, dielectric loss tangent, and film-forming properties were measured. The results are shown in Table 3.

[0155] [Table 3]

[0156] Example 21 250 parts (100 parts solids) of modified epoxy resin varnish R8, 25.6 parts of curing agent H1, and 0.3 parts of curing accelerator D2 were blended and dissolved in a mixed solvent prepared from MEK, propylene glycol monomethyl ether, and N,N-dimethylformamide to obtain a resin composition varnish. The resulting resin composition varnish was impregnated into glass cloth (Nitto Boseki Co., Ltd., WEA 7628 XS13, 0.18 mm thick). The impregnated glass cloth was dried in a hot air circulating oven at 150 °C for 9 minutes to obtain a prepreg.

[0157] The resulting prepreg was loosened and sieved to a powder form (100-mesh pass). The resulting prepreg powder was placed in a fluororesin mold and vacuum pressed at 2 MPa under the following temperature conditions: 130°C for 15 minutes and 190°C for 80 minutes to obtain a 30 mm square x 1 mm thick test piece. The Tg and dielectric loss tangent of the test piece are shown in Table 4.

[0158] Example 22, Comparative Examples 6 and 7 The components were blended in the amounts (parts) shown in Table 4, and the same operations as in Example 21 were carried out to obtain a resin composition varnish, a prepreg, and a test piece. The same tests as in Example 21 were carried out, and the results are shown in Table 4.

[0159] [Table 4]

[0160] As can be seen from Table 2, the modified epoxy resin of the present invention has excellent dielectric properties and heat resistance. Furthermore, as can be seen from Tables 3 and 4, the cured product made from the resin composition of the present invention also has excellent dielectric properties and heat resistance.

Claims

1. A modified epoxy resin represented by the following formula (1) and having an epoxy equivalent of 400 to 100,000 g / eq. 【Chemistry 1】 (In the formula, X is a divalent group and has at least a divalent group represented by the above formula (2). Y is independently a hydrogen atom, an acyl group having 2 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of the acyl group is the above. n is the average number of repetitions and is 1 or more and 500 or less. A is an arylene group, R 1 is selected from —O— or —N(Ph)— (Ph: phenyl group), and R 2 is —CO— or —SO 2 —.)

2. A resin composition comprising the modified epoxy resin according to claim 1 and a curing agent.

3. 3. The resin composition according to claim 2, comprising 0.1 to 100 parts by mass of the curing agent as a solid content per 100 parts by mass of the epoxy resin solid content.

4. 4. The resin composition according to claim 2 or 3, comprising the modified epoxy resin according to claim 1, another epoxy resin, and a curing agent, wherein the mass ratio of the solid content of the modified epoxy resin to the other epoxy resin is 99 / 1 to 1 / 99.

5. 5. The resin composition according to claim 4, comprising 0.1 to 100 parts by mass of the curing agent as solid content per 100 parts by mass of the total solid content of the modified epoxy resin and the other epoxy resin.

6. The resin composition according to any one of claims 2 to 5, wherein the curing agent is at least one selected from the group consisting of acrylic ester resins, melamine resins, urea resins, phenolic resins, acid anhydride compounds, amine compounds, imidazole compounds, amide compounds, cationic polymerization initiators, organic phosphines, polyisocyanate compounds, blocked isocyanate compounds, carbodiimide compounds, and active ester curing agents.

7. A cured product obtained by curing the resin composition according to any one of claims 2 to 6.

8. A laminate for electric / electronic circuits, which is obtained by using the resin composition according to any one of claims 2 to 6.

9. A method for producing a modified epoxy resin, comprising reacting a bifunctional epoxy resin represented by the following formula (3) with a compound represented by the following formula (4) to obtain a modified epoxy resin represented by the following formula (1) having an epoxy equivalent of 400 to 100,000 g / eq.: 【Chemistry 2】 (where X １ , X ２ is a divalent group, and X １ and / or X ２ contains a divalent group represented by the above formula (2). X is a divalent group and has at least a divalent group represented by the above formula (2). G is a glycidyl group, and Y is independently a hydrogen atom, an acyl group having 2 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Z is the above acyl group. Q is an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Q is the above acyl group. Here, the compound represented by formula (4) may be a mixture of two or more selected from compounds in which both Qs are acyl groups, compounds in which one Q is an acyl group, and compounds in which both Qs are hydrogen atoms. m is the average number of repeats and is 0 to 6. n is the average number of repeats and is 1 to 500. A is an arylene group, R 1 is selected from —O— or —N(Ph)— (Ph: phenyl group), and R 2 is —CO— or —SO 2 —.

10. A method for producing a modified epoxy resin, comprising reacting 0.05 mol to 2.0 mol of an acid anhydride represented by the following formula (6) with 1 mol of an alcoholic hydroxyl group equivalent of an epoxy resin represented by the following formula (5), to obtain a modified epoxy resin represented by the following formula (1) having an epoxy equivalent of 400 to 100,000 g / eq. 【Transformation 3】 (In the formula, X is a divalent group and includes a divalent group represented by the above formula (2). L is independently a hydrogen atom or a glycidyl group. Y is independently a hydrogen atom, an acyl group having 2 to 20 carbon atoms, or a glycidyl group. Z is an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Z are the above acyl groups. T is an acyl group having 2 to 20 carbon atoms. n is the average number of repeating groups and is 1 or more and 500 or less. A is an arylene group, R 1 is selected from —O— or —N(Ph)— (Ph: phenyl group), and R 2 is —CO— or —SO 2 —.)

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