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

Abstract

Provided are: a modified epoxy resin having excellent dielectric properties, heat conductivity, and fluidity; a resin composition containing said modified epoxy resin and a curing agent; a cured product thereof having excellent dielectric properties and heat conductivity; and a laminate for electric / electronic circuits.　This modified epoxy resin is represented by formula (1) and has an epoxy equivalent of 250-50,000 g / eq. (In the formula, X represents a divalent group, and has a phenylene group or a naphthylene group, and a biphenylene group. Y represents a hydrogen atom, an acyl group having 2-20 carbon atoms, or a glycidyl group. Z represents an acyl group having 2-20 carbon atoms or a hydrogen atom, and 5 mol% or more of Z is the acyl group. The average of n is 1-500.)

Description

[Technical Field]

[0001] The present invention relates to a modified epoxy resin having excellent dielectric properties, thermal conductivity, and fluidity, a resin composition containing this modified epoxy resin and a curing agent, a cured product thereof having excellent dielectric properties and thermal conductivity, and a laminate for electric and electronic circuits made using 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 not only heat resistance but also solvent solubility and resin compatibility. 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 excellent dielectric properties and thermal conductivity to accompany thinner and more highly functional substrates.

[0004] In response to such demands, a method has been proposed for improving the dielectric properties by converting the hydroxyl groups present in the side chains of phenoxy resins into esters using acetyl or benzoyl groups. Patent Document 1 discloses that phenoxy resins obtained by reacting bifunctional epoxy resins with diester compounds and their cured products have excellent dielectric properties, but their thermal conductivity is still insufficient.

[0005] On the other hand, Patent Document 2 exemplifies a method for improving both the dielectric properties and thermal conductivity by introducing a rigid moiety such as a biphenyl structure into the main skeleton and further converting the side chain hydroxyl groups of the phenoxy resin into esters. However, this method significantly deteriorates the fluidity of the phenoxy resin, which causes the problem of poor impregnation when the phenoxy resin composition is impregnated into glass cloth or the like. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-089165 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-18679 Summary of the Invention

[0007] An object of the present invention is to provide an epoxy resin having excellent dielectric properties, thermal conductivity, and fluidity, and to provide a cured product having excellent dielectric properties and thermal conductivity by curing a resin composition containing the epoxy resin.

[0008] In order to solve the above problems, the present inventors have conducted extensive research on epoxy resins and have found that epoxy resins having a specific structure have excellent dielectric properties, thermal conductivity, and fluidity, and have also found that a cured product obtained by curing a resin composition containing such an epoxy resin has excellent dielectric properties and thermal conductivity, thereby completing the present invention.

[0009] That is, the present invention relates to a modified epoxy resin represented by the following formula (1) and having an epoxy equivalent of 250 to 50,000 g / eq. [ka] During the ceremony, X is a divalent group having at least a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group. The phenylene group, biphenylene group, and naphthylene group may have a substituent on each aromatic ring. 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-mentioned group. n is the average number of repetitions, and is 1 to 500.

[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 of the present invention 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 anhydrides, 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 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-mentioned modified epoxy resin, which comprises reacting a bifunctional epoxy resin represented by the following formula (5) with a compound represented by the following formula (6). [ka] During the ceremony, X 1 , X 2 is a divalent group, and X 1 and / or X 2 includes a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group. The phenylene group, the biphenylene group, and the naphthylene group may have a substituent on each aromatic ring. G is a glycidyl group. Q is independently 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. The compound represented by formula (6) may be a compound in which at least one Q is an acyl group, or a mixture of a compound in which at least one Q is an acyl group and a compound in which both Q are hydrogen atoms. m is the average number of repetitions, and is between 0 and 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 (8) with 1 mole of an alcoholic hydroxyl group equivalent of the epoxy resin represented by the following formula (7). [ka] During the ceremony, X is a divalent group, and includes a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group. The phenylene group, the biphenylene group, and the naphthylene group may have a substituent on each aromatic ring. 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 to 500.

[0016] According to the present invention, a modified epoxy resin having excellent dielectric properties, thermal conductivity, and fluidity can be provided. Furthermore, a resin composition using this modified epoxy resin can provide a cured product having excellent dielectric properties and thermal conductivity. [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 7. [Figure 4] 1 is an IR chart of the modified epoxy resin of Example 7. [Figure 5] 1 is a GPC chart of the modified epoxy resin of Example 8. [Figure 6] 1 is an IR chart of the modified epoxy resin of Example 8. 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 250 to 50,000, and has a structure in which a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group, and further in which some or all of the hydrogen atoms in the hydroxyl groups have been substituted (modified) with an acyl group (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 400 to 40,000, more preferably 600 to 30,000, and even more preferably 700 to 20,000. For film applications, film-forming properties are required, so the epoxy equivalent is desirably higher, 5,000 to 50,000, more preferably 8,000 to 49,000, and even more preferably 9,000 to 48,000. On the other hand, in substrate applications where the resin is used by impregnating a substrate, good impregnation properties are required, so the epoxy equivalent is preferably low, 250 to 10,000, more preferably 260 to 5,000, and even more preferably 270 to 3,000.

[0019] The weight-average molecular weight (Mw) of the modified epoxy resin of the present invention is preferably 1,000 or more and 200,000 or less. Here, if Mw is less than 1,000, there is a risk that the introduction of a structure that improves the heat resistance of the cured product will be reduced. If Mw is more than 200,000, compatibility may decrease and the resin may be difficult to handle. 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 and excellent dielectric properties, as well as low moisture absorption, solvent solubility, and resin compatibility. Furthermore, the presence of a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group, results in excellent thermal conductivity and fluidity. The phenylene group, biphenylene group, and naphthylene group may have a substituent on each aromatic ring.

[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 a divalent group consisting of a phenylene group and / or a naphthylene group (X 1 ), a divalent group consisting of a biphenylene group (X 2) is essential, and other divalent groups (X 3 ) may have a group (X 1 ) and group (X 2 The molar ratio of the groups (X) is preferably 1 / 9 to 9 / 1, more preferably 2 / 8 to 8 / 2, further preferably 3 / 7 to 7 / 3, and particularly preferably 4 / 6 to 6 / 4. 1 ) and group (X 2 The total of (a) and (b) is preferably 1 mol % or more, more preferably 10 mol % or more, even more preferably 30 mol % or more, and particularly preferably 50 mol % or more, based on the total number of moles of X.

[0023] In addition, phenylene group and naphthylene group (X 1 ), and biphenylene groups (X 2 ) may be unsubstituted or may have a substituent on each aromatic ring. The number of substituents is preferably 0 to 2 for a phenylene group, 0 to 2 for a biphenylene group, and 0 to 4 for a naphthylene group. The substituent is preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aryl group having 6 to 12 carbon atoms, an aralkyl group having 7 to 13 carbon atoms, an aryloxy group having 6 to 12 carbon atoms, an aralkyloxy group having 7 to 13 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkynyl group having 2 to 12 carbon atoms. The phenylene group, biphenylene group, and naphthylene group are preferably unsubstituted or substituted with an alkyl group having 1 to 4 carbon atoms, and more preferably unsubstituted or substituted with a methyl group, because a substituent with a large number of carbon atoms may result in a decrease in heat resistance.

[0024] The phenylene group is represented by the following formula (2), the naphthylene group is represented by the following formula (3), and the biphenylene group is represented by the following formula (4). [ka] Here, R is a substituent, i and k are integers of 0 to 4, and j is an integer of 0 to 6.

[0025] 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, a cyclododecyl group, a benzyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a naphthylmethyl group, a phenethyl group, and a 2-phenylisopropyl group.

[0026] The alkoxy group having 1 to 12 carbon atoms may be linear, branched, or cyclic, and examples thereof include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a t-butoxy group, an n-pentoxy group, an isopentoxy group, a neopentoxy group, a t-pentoxy group, a cyclopentoxy group, an n-hexyloxy group, an isohexyloxy group, a cyclohexyloxy group, an n-heptoxy group, a cycloheptoxy group, a methylcyclopentoxy group, an alkoxy group having 1 to 12 carbon atoms ... Examples thereof include a cyclohexyloxy group, an n-octyloxy group, a cyclooctyloxy group, an n-nonyloxy group, a 3,3,5-trimethylcyclohexyloxy group, an n-decyloxy group, a cyclodecyloxy group, an n-undecyloxy group, an n-dodecyloxy group, a cyclododecyloxy group, a benzyloxy group, a methylbenzyloxy group, a dimethylbenzyloxy group, a trimethylbenzyloxy group, a naphthylmethoxy group, a phenethyloxy group, and a 2-phenylisopropoxy group.

[0027] Examples of the aryl group having 6 to 12 carbon atoms include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, an ethylphenyl group, a styryl group, a xylyl group, an n-propylphenyl group, an isopropylphenyl group, a mesityl group, an ethynylphenyl group, a naphthyl group, and a vinylnaphthyl group.

[0028] Examples of the aralkyl group having 7 to 13 carbon atoms include a benzyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a phenethyl group, a 1-phenylethyl group, a 2-phenylisopropyl group, and a naphthylmethyl group.

[0029] Examples of the aryloxy group having 6 to 12 carbon atoms include a phenoxy group, an o-tolyloxy group, an m-tolyloxy group, a p-tolyloxy group, an ethylphenoxy group, a styryloxy group, a xylyloxy group, an n-propylphenoxy group, an isopropylphenoxy group, a mesityloxy group, an ethynylphenoxy group, a naphthyloxy group, and a vinylnaphthyloxy group.

[0030] Examples of the aralkyloxy group having 7 to 13 carbon atoms include a benzyloxy group, a methylbenzyloxy group, a dimethylbenzyloxy group, a trimethylbenzyloxy group, a phenethyloxy group, a 1-phenylethyloxy group, a 2-phenylisopropyloxy group, and a naphthylmethyloxy group.

[0031] Examples of alkenyl groups having 2 to 12 carbon atoms include vinyl, 1-propenyl, 2-propenyl, 1-methylvinyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl, cyclohexenyl, cyclohexadienyl, cinnamyl, and naphthylvinyl groups.

[0032] Examples of the alkynyl group having 2 to 12 carbon atoms include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1,3-butadienyl group, a phenylethynyl group, and a naphthylethynyl group.

[0033] The divalent group other than a phenylene group, a naphthylene group, and a biphenylene group 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-, or -SO2-. 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.

[0034] 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.

[0035] Specific examples of the aliphatic skeleton include alkylene glycol skeletons such as ethylene glycol, propylene glycol, and butylene glycol.

[0036] Specific examples of the alicyclic skeleton include hydrogenated bisphenol skeletons such as hydrogenated bisphenol A, hydrogenated bisphenol F, and hydrogenated bisphenol acetophenone.

[0037] 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 the aralkyl group having 7 to 13 carbon atoms include a benzyl group, a methylbenzyl group, a dimethylbenzyl group, a trimethylbenzyl group, a phenethyl group, a 2-phenylisopropyl group, and a naphthylmethyl group. 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.

[0038] In formula (1), Z is an acyl group having 2 to 20 carbon atoms (hereinafter sometimes simply referred to as "acyl group") or a hydrogen atom. 5 mol % or more of Z are acyl groups, and the remainder are hydrogen atoms. The content (mol %) of acyl groups in all Z in formula (1) is also referred to as the acylation rate. The acylation rate is preferably 10 mol % or more, more preferably 50 mol % or more, even more preferably 70 mol % or more, and even more preferably 90 mol % or more. On the other hand, there is no upper limit to the acylation rate, and it may be 100%, but in terms of reactivity, it is about 95%. 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 can be further improved. Improvements in solubility and moisture resistance can also be expected. On the other hand, for example, when fine-tuning adhesion to metals, by leaving some of the Z's as hydrogen atoms, 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, as long as this does not significantly affect other physical properties, including moisture resistance. Specific examples of the acyl group are the same as those exemplified above for Y, and preferred acyl groups are also the same.

[0039] In formula (1), n ​​is the number of repeats and is an average value. The value ranges from 1 to 500. From the viewpoint of flowability 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.

[0040] 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 (5) is reacted with a diester compound represented by the above formula (6), which may hereinafter be referred to as production method (A). (B): A production method in which an epoxy resin represented by the above formula (7) (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 organic acid anhydride, an organic acid halide, or an organic acid ester, preferably an organic acid anhydride. 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).

[0041] The above production method (A) is a method in which a bifunctional epoxy resin represented by formula (5) is reacted with a diester compound represented by formula (6). In formula (5), G is a glycidyl group, m is the number of repetitions, and the average value is 0 or more and 6 or less, preferably 0 or more and 3 or less. In formula (6), Q is independently an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and can be defined as above. In formula (6), 5 mol % or more of Q is an acyl group having 2 to 20 carbon atoms, and the remainder is a hydrogen atom. Here, the diester compound represented by formula (6) is 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 bifunctional phenol compounds in which both are hydrogen atoms, and may be a diester compound or a monoester compound, or a mixture containing a diester compound and / or a monoester compound. The diester compound may be a diester compound in which both Qs are acyl groups, or a mixture in which the main component (50 mol% or more) is a diester compound. The acylation rate decreases when the amount of monoester compound or bifunctional phenol compound is large.

[0042] X in equation (5) 1 and X in equation (6) 2 is selected to give X in formula (1). Therefore, either or both of the bifunctional epoxy resin represented by formula (5) or the diester compound represented by formula (6) contain a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group, and these groups are X 1 and X 2 For example, when only one of the bifunctional epoxy resins represented by formula (5) contains a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group, X 1 an epoxy resin in which X is a phenylene group; 1 In the case where only one of the compounds represented by formula (6) contains such a group, or in the case where both of the compounds represented by formula (6) contain such a group, a mixture of epoxy resins containing at least one of the epoxy resins represented by formula (6) and an epoxy resin in which X is a biphenylene group can be used. 1 or X 2 From the viewpoint of fully exhibiting the dielectric properties and thermal conductivity attributable to phenylene groups and biphenylene groups, or naphthylene groups and biphenylene groups, the phenylene groups and biphenylene groups, or naphthylene groups and biphenylene groups, are 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 phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group. As long as this requirement is met, these groups may be contained in either the bifunctional epoxy resin represented by formula (5) and / or the diester compound represented by formula (6), which are raw materials, and the proportions thereof are not limited. 1 Or X in formula (6) 2 When the phenylene group and the biphenylene group, or the naphthylene group and the biphenylene group are not included as X 1 or X 2 Other divalent groups as described above can be introduced into .

[0043] The bifunctional epoxy resin used in the production method (A) of the present invention is an epoxy resin represented by the above formula (5), 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 (5) 1 is the same as:

[0044] The epoxy equivalent (g / eq.) of the raw material epoxy resin represented by formula (5) is preferably 100 to 400, more preferably not more than 300. The value of m in formula (5) is preferably 0 to 1, more preferably not more than 0.3.

[0045] 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.

[0046] 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. If the amount is less than this, the amount of residual hydrolyzable chlorine may increase. The alkali metal compound is used in the form of an aqueous solution, an alcohol solution, or a solid.

[0047] 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 in some cases.

[0048] 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 purification. The temperature is preferably 100°C or lower, and more preferably 85°C or lower.

[0049] 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.

[0050] The diester compound of formula (6) used in the production method (A) of the present invention can be obtained, for example, by acylation of the bifunctional phenol compound with an acid anhydride of an organic acid, a halide of an organic acid, or a condensation reaction with an organic acid.

[0051] By using an epoxy resin in which m in formula (5) is 0 as a raw material, the modified epoxy resin of the present invention will not contain secondary hydroxyl groups, and dielectric properties and moisture resistance can be further improved. Furthermore, for example, when fine-tuning adhesion to metals, by using an epoxy resin with an appropriate m number, it is possible to intentionally cause an appropriate amount of secondary hydroxyl groups to be present in the modified epoxy resin of the present invention, as long as other physical properties, including moisture resistance, are not significantly affected, and the raw materials can be appropriately adjusted within a range that satisfies the resulting Z in formula (1).

[0052] The amounts of the bifunctional epoxy resin and diester compound of formula (6) used need to be adjusted depending on the epoxy equivalent of the desired modified epoxy resin. Preferably, the total amount of ester groups and phenolic hydroxyl groups is 0.3 to 1.0 equivalents per equivalent of epoxy groups. This equivalent ratio facilitates high molecular weight formation while maintaining epoxy groups at the molecular terminals. It is also possible to replace a portion of the diester compound of formula (6) with the bifunctional phenol compound. As described 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 the 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.

[0053] 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, imidazole compounds, organic phosphorus compounds, and quaternary ammonium salts. These catalysts may be used alone or in combination of two or more.

[0054] Examples of tertiary amines include triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, and 2,4,6-tris(dimethylaminomethyl)phenol.

[0055] Examples of cyclic amines include 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).

[0056] Examples of imidazole compounds include 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, and 1-benzyl-2-phenylimidazole.

[0057] 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, and tetrabutylphosphonium hydride; and phosphonium salts such as methyl cyclohexyl phosphonium chloride, trimethyl cyclohexyl phosphonium bromide, trimethyl benzyl phosphonium chloride, trimethyl benzyl phosphonium bromide, tetraphenyl phosphonium bromide, triphenyl methyl phosphonium bromide, triphenyl methyl phosphonium iodide, triphenyl ethyl phosphonium chloride, triphenyl ethyl phosphonium bromide, triphenyl ethyl phosphonium iodide, triphenyl benzyl phosphonium chloride, and triphenyl benzyl phosphonium bromide.

[0058] Examples of quaternary ammonium salts include 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.

[0059] Among the catalysts listed above, 4-dimethylaminopyridine, 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.

[0060] 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.

[0061] 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.

[0062] Examples of aromatic solvents include benzene, toluene, and xylene.

[0063] Examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, dioxane, diisobutyl ketone, isophorone, methylcyclohexanone, and acetophenone.

[0064] Examples of amide solvents include formamide, N-methylformamide, N,N-dimethylformamide (DMF), acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, and N-methylpyrrolidone.

[0065] 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 monoalkyl 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 dialkyl ethers such as diethylene 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.

[0066] 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.

[0067] Other solvents include, for example, dimethyl sulfoxide, sulfolane, and N-methyl-2-pyrrolidone.

[0068] 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.

[0069] 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.

[0070] Next, the production method (B) of the present invention will be described. As described above, production method (B) involves reacting epoxy resin (a) represented by formula (7) with an acid component (acylating agent) such as an acid anhydride of an organic acid, an organic acid halide, or an organic acid ester. Preferably, this method involves reacting 0.05 to 2.0 moles of acid anhydride represented by formula (8) per mole of the alcoholic hydroxyl group equivalent of the epoxy resin to obtain a modified epoxy resin represented by formula (1) having an epoxy equivalent of 250 to 50,000 g / eq., i.e., the modified epoxy resin of the present invention.

[0071] The raw material epoxy resin (a) represented by formula (7) essentially contains a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group, in X in formula (7). Here, n in formula (7) is the repeating number and is an average value. Its value ranges from 1 to 500. From the viewpoint of flowability 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. This epoxy resin (a) can be obtained by a conventional method. For example, it can be produced by reacting a bifunctional phenol compound having a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group (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 a bifunctional epoxy resin having a phenylene group and a biphenylene group, or a naphthylene group and a biphenylene group, with 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.

[0072] 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.

[0073] Examples of the bifunctional phenol compound (a) used in the one-stage and two-stage production methods include hydroquinone and 4,4'-dihydroxybiphenyl, or 1,6'-dihydroxynaphthalene and 4,4'-dihydroxybiphenyl.

[0074] 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.

[0075] First, the one-stage method will be described. In the one-step process, a bifunctional phenol compound (a) 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 an 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 (5) 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 (a). 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 (a).

[0076] 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.

[0077] 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.

[0078] 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.

[0079] Next, the two-stage method will be described. As the bifunctional epoxy resin serving as the raw material epoxy resin in the two-stage process, the same bifunctional epoxy resin as that represented by the above formula (5) used in the production method (A) of the present invention is used.

[0080] 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 (5), 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.

[0081] 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 (5) 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.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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 (7) obtained in this manner. Acylation can be carried out by direct esterification or by a method such as transesterification.

[0086] 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, organic acid halides, and organic acid esters. Of these, acid anhydrides of organic acids are preferred.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] 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%.

[0094] 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.

[0095] 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.

[0096] 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 relative to 100 parts by mass of the solid content of the modified epoxy resin of the present invention, more preferably 0.5 to 80 parts by mass, and even more preferably 1 to 50 parts by mass. Note that this refers to the amount of non-volatile content (solid content) in the resin composition. In the present invention, the term "solid content" means the components excluding the solvent, and includes not only solid modified epoxy resins and other epoxy resins, but also semi-solid and viscous liquid substances.

[0097] The curing agent used in the resin composition of the present invention is not particularly limited, and any curing agent generally known as an epoxy resin curing agent can be used. From the viewpoint of improving heat resistance, preferred curing agents include phenolic resins, amide compounds, imidazole compounds, and active ester curing agents. These curing agents may be used alone or in combination of two or more.

[0098] Examples of phenolic resins 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, 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.

[0099] Examples of the amide compounds include dicyandiamide and its derivatives, polyamide resins, and the like.

[0100] Examples of the imidazole compounds 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'-methylimidazole] Examples of suitable imidazole compounds 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 imidazole compounds. Note that, because imidazole compounds 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.

[0101] 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.

[0102] Examples of other curing agents that can be used in the resin composition of the present invention include acrylic ester resins, melamine resins, urea resins, cationic polymerization agents, amine compounds, acid anhydrides, tertiary amines, organic phosphines, phosphonium salts, tetraphenylboron salts, organic acid dihydrazides, boron halide amine complexes, polymercaptan curing agents, isocyanate compounds, polyisocyanate compounds, blocked isocyanate compounds, carbodiimide compounds, etc. These other curing agents may be used alone, or two or more may be mixed in any combination and ratio.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] Examples of polyglycidyl ester compounds include dimer acid type epoxy resins, hexahydrophthalic acid type epoxy resins, and trimellitic acid type epoxy resins.

[0107] Examples of the alicyclic epoxy compound include aliphatic cyclic epoxy resins such as CELLOXIDE 2021 (manufactured by Daicel Chemical Industries, Ltd.).

[0108] 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.

[0109] 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. Furthermore, when the modified epoxy resin of the present invention is used together with another epoxy resin, the curing agent is preferably contained in an amount of 0.1 to 100 parts by mass, more preferably 0.5 to 80 parts by mass, and even more preferably 1 to 50 parts by mass, as solid content, per 100 parts by mass of the total solid content of the modified epoxy resin and the other epoxy resin.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] 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.

[0114] If necessary, a curing accelerator or catalyst can be used in the resin composition of the present invention. Examples of the curing accelerator or catalyst include imidazole compounds, 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.

[0115] 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.

[0116] 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.

[0117] 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.

[0118] 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.

[0119] 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.

[0120] Other components include organic pigments such as quinacridone, azo, and phthalocyanine pigments; inorganic pigments such as titanium oxide, metal foil pigments, and rust-preventive pigments; UV absorbers such as hindered amines, benzotriazoles, and benzophenones; antioxidants such as hindered phenols, phosphorus, sulfur, and hydrazides; 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 antifoaming agents. Even for components not listed as examples, known components can be used without limitation. The amount of these other components is preferably 0.01 to 20% by mass based on the total solids content of the resin composition.

[0121] 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%.

[0122] 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.

[0123] 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 in which the viscosity of the resin composition has been adjusted with a solvent, and then heated and dried to semi-cure (B-stage) the resin composition. For example, the prepreg can be obtained by heating and drying at 100 to 200°C for 1 to 40 minutes. The amount of the resin composition in the prepreg is preferably 30 to 80% by mass.

[0124] 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. This laminate 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.

[0125] 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.

[0126] 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.

[0127] 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.

[0128] The cured product and laminate for electric / electronic circuits obtained from the resin composition of the present invention have excellent dielectric properties and thermal conductivity. [Example]

[0129] 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."

[0130] (1) Weight average molecular weight (Mw) and number average molecular weight (Mn): The chromatographic index was determined by GPC measurement. Specifically, a Tosoh HLC8320 GPC main unit equipped with columns (TSKgel SuperH-H, SuperH2000, SuperHM-H, and SuperHM-H, all manufactured by Tosoh) was used. The column temperature was 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 was dissolved in 10 mL of THF and filtered through a 0.45 μm microfilter. 50 μL of the sample was used. A calibration curve was prepared using standard polystyrenes (Tosoh PStQuick A, PStQuick B, and PStQuick C). Data processing was performed using a Tosoh GPC8020 Model II version 6.00.

[0131] (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 500 to 4000 cm. -1 The transmittance was measured.

[0132] (3) Epoxy equivalent: Measurements were carried out in accordance with JIS K7236, and the unit was expressed in g / eq. Specifically, a potentiometric titrator (Hiranuma Sangyo Co., Ltd., COM-1600ST) was used, and cyclohexanone was used as the solvent, to which tetraethylammonium bromide acetate solution was added, followed by a 0.1 mol / L perchloric acid-acetic acid solution. For solvent-diluted products (resin varnishes), the solid content was calculated from the nonvolatile content.

[0133] (4) Non-volatile content (solid content): Measurement was performed in accordance with JIS K7235. The drying temperature was 200°C and the drying time was 60 minutes.

[0134] (5) 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 1 to 6, 8 to 16, and Comparative Examples 1 to 4 were evaluated by measuring them 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 17 and 18 and Comparative Examples 5 and 6 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 23°C and humidity 50% RH using test pieces measuring 30 mm square and 1 mm thick.

[0135] (6) Thermal conductivity: Measurements were made by the transient hot wire method using a NETZSCH LFA447 thermal conductivity meter.

[0136] (7) Liquidity: The solution viscosity was measured at 25°C using a B-type rotational viscometer TVB-10M manufactured by Toki Sangyo Co., Ltd. and evaluated.

[0137] The abbreviations used in the examples and comparative examples are as follows:

[0138] [Bifunctional epoxy resin] A1: Hydroquinone-type epoxy resin (Nippon Steel Chemical & Material Co., Ltd., ZX-1027, epoxy equivalent 130, m≒0.18) [ka] A2: Naphthalene-type liquid epoxy resin (DIC Corporation, Epicron HP4032D, epoxy equivalent 142, m≒0.06) [ka] A3: Biphenyl-type epoxy resin (Mitsubishi Chemical Corporation, YX-4000, epoxy equivalent 196, melting point 105°C, m≒0.13) [ka] A4: Bisphenol A liquid epoxy resin (Nippon Steel Chemical & Material Co., Ltd., YD-128, epoxy equivalent 186, m≒0.11) 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 (5).

[0139] [Diester compounds] B1: 2,5-di-t-butyl-1,4-diacetoxybenzene (active equivalent = 153) obtained in Synthesis Example 1 [ka] B2: 1,6-diacetoxynaphthalene (active equivalent = 122) obtained in Synthesis Example 2 [ka] B3: 4,4'-diacetoxybiphenyl (Tokyo Chemical Industry Co., Ltd., active equivalent = 135) [ka]

[0140] [Bifunctional phenolic compounds] C1: 4,4'-dihydroxybiphenyl (Tokyo Chemical Industry Co., Ltd., hydroxyl equivalent: 93) C2: 2,5-di-t-butyl-hydroquinone (Tokyo Chemical Industry Co., Ltd., hydroxyl equivalent: 111) C3: 1,6-dihydroxynaphthalene (Tokyo Chemical Industry Co., Ltd., hydroxyl equivalent: 80)

[0141] [catalyst] D1: 4-Dimethylaminopyridine (Fujifilm Wako Pure Chemical Industries, Ltd.) D2: 2-ethyl-4-methylimidazole (Curesol 2E4MZ, manufactured by Shikoku Chemicals Corporation)

[0142] [Solvents] S1: Cyclohexanone S2: Methyl ethyl ketone (MEK)

[0143] [Acid anhydride] E1: Acetic anhydride (Fujifilm Wako Pure Chemical Industries, Ltd.) E2: Benzoic anhydride (Tokyo Chemical Industry Co., Ltd.)

[0144] [Hardening agent] H1: Phenol novolac resin (manufactured by Aica Kogyo Co., Ltd., Shounol BRG-557, hydroxyl group equivalent: 105) H2: 2-ethyl-4-methylimidazole (Curesol 2E4MZ, manufactured by Shikoku Chemicals Corporation)

[0145] 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 C2, 92 parts of acid anhydride E1, and 71 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 138 parts of diester compound B1.

[0146] 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 C3, 128 parts of acid anhydride E1, and 99 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 153 parts of diester compound B2.

[0147] 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 epoxy resin A1, 99 parts of diester compound B3, and 50 parts of reaction solvent S1 at room temperature. The mixture was heated to 130°C while stirring under a nitrogen gas stream, and 0.1 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 using 50 parts of dilution solvent S1 and 199 parts of S2 to obtain a modified epoxy resin varnish (R1) with a non-volatile content of 40%.

[0148] Examples 2 to 9, Comparative Examples 1 to 2 A resin varnish was obtained in the same manner as in Example 1, using the amounts (parts) of each raw material and the reaction times 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.

[0149] [Table 1]

[0150] Example 10 100 parts (40 parts solids) of the resin varnish (HR1) obtained in Comparative Example 1 and 600 parts of reaction solvent S1 were blended, and the mixture was heated to 100°C. Then, 4 parts of acid anhydride E1 were added and the mixture was allowed to react for 4 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 oven at 150°C and 0.4 kPa (3 torr) for 1 hour to obtain a modified epoxy resin. 21 parts of dilution solvent S1 and 42 parts of dilution solvent S2 were added to the resulting modified epoxy resin, and the mixture was dissolved uniformly to obtain a resin varnish (R10) with a nonvolatile content of 40%.

[0151] Example 11 A resin varnish (R11) was obtained in the same manner as in Example 10, except that the amount of acid anhydride E1 was 18 parts, the amount of dilution solvent S1 was 25 parts, and the amount of S2 was 51 parts.

[0152] Example 12 A resin varnish (R12) was obtained in the same manner as in Example 10, except that 41 parts of E2 were used instead of acid anhydride E1, 29 parts of dilution solution S1, and 59 parts of S2 were used.

[0153] The resin varnishes R1 to R12 and HR1 to HR2 obtained in Examples 1 to 12 and Comparative Examples 1 and 2 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, Mw, and fluidity of the resin varnish were measured, and the dielectric properties and thermal conductivity of the resin film were measured. The results are shown in Table 2. In the table, "acylation rate" refers to the acyl group content (mol%) in the total Z, "phenylene group rate," "naphthylene group rate," and "biphenylene group rate" refer to the phenylene group content (mol%), naphthylene group content (mol%), and biphenylene group content (mol%) in the total X, respectively, and "-" indicates not measured. In Example 7, a resin film was not obtained, so the dielectric properties and thermal conductivity were not measured. In Comparative Example 1, insoluble components (crystals) were precipitated, so the fluidity was not measured. The examples using resin varnishes HR1 and HR2 are comparative examples.

[0154] [Table 2]

[0155] Examples 13 to 16, Comparative Examples 3 and 4 A resin composition was prepared by blending 30 parts (12 parts solids) of the modified epoxy resin varnishes (R1-R4, H1, HR2) obtained in Examples 1-4 and Comparative Examples 1 and 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 agent H2. This was then applied to an iron plate to a dry thickness of 100 μm and dried at 150°C for 1 hour in a dryer to obtain a cured polymer film. The dielectric properties and thermal conductivity were measured, and the results are shown in Table 3.

[0156] [Table 3]

[0157] Example 17 250 parts (100 parts solids) of the modified epoxy resin varnish (R7) obtained in Example 7, 25.6 parts of curing agent H1, and 0.3 parts of H2 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.

[0158] 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 dielectric properties and thermal conductivity of the test piece were measured, and the results are shown in Table 4.

[0159] Example 18 A prepreg and a test piece were obtained in the same manner as in Example 17, except that R8 was used as the modified epoxy resin varnish. The same tests as in Example 17 were carried out, and the results are shown in Table 4.

[0160] Comparative Example 5 A prepreg and a test piece were obtained in the same manner as in Example 17, except that 100 parts of A5 were used instead of 250 parts of the modified epoxy resin varnish (solid content 100 parts). The same tests as in Example 17 were carried out, and the results are shown in Table 4.

[0161] Comparative Example 6 A prepreg and a test piece were obtained in the same manner as in Example 17, except that 100 parts of A6 were used instead of 250 parts of the modified epoxy resin varnish (solid content 100 parts). The same tests as in Example 17 were carried out, and the results are shown in Table 4.

[0162] [Table 4]

[0163] As can be seen from Table 2, the modified epoxy resin of the present invention is excellent in dielectric properties, thermal conductivity, and fluidity. Furthermore, as can be seen from Tables 3 and 4, the cured product made from the resin composition of the present invention is also excellent in dielectric properties and thermal conductivity. [Industrial Applicability]

[0164] The modified epoxy resin and resin composition of the present invention are applicable to various fields such as adhesives, paints, civil engineering and building materials, and insulating materials for electric and electronic components, and are particularly useful in the electric and electronic fields as insulating casting materials, laminate materials, sealing materials, etc. The phenoxy resin of the present invention and a resin composition containing it are suitable for use in laminates for electric and electronic circuits such as multilayer printed wiring boards and capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor sealing materials, underfill materials, interchip fill materials for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, etc.

Claims

1. A modified epoxy resin represented by the following formula (1) and having an epoxy equivalent of 250 to 50,000 g / eq.: 【Chemical 1】 (In the formula, X is a divalent group, and X is a phenylene group represented by the following formula (2) or a biphenylene group represented by the following formula (4), or X is a naphthylene group represented by the following formula (3) or a biphenylene group represented by the following formula (4). The phenylene group, biphenylene group, and naphthylene group may have a substituent on each aromatic ring. 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. n is the average number of repeating units and is 1 to 500.) 【Chemistry 2】 Here, in formulas (2) to (4), R is a substituent, i and k are integers of 0 to 4, and j is an integer of 0 to 6.

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. A resin composition 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, wherein the curing agent is contained in an amount of 0.1 to 100 parts by mass 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 anhydrides, 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 5.

8. A laminate for electric / electronic circuits, which is obtained by using the resin composition according to any one of claims 2 to 5.

9. A method for producing a modified epoxy resin, comprising reacting a bifunctional epoxy resin represented by the following formula (5) with a compound represented by the following formula (6) to obtain a modified epoxy resin represented by the following formula (1) having an epoxy equivalent of 250 to 50,000 g / eq.: 【Chemistry 3】 (where X １ , X ２ are each independently a divalent group, and X １ and / or X ２ includes a phenylene group represented by the following formula (2) and a biphenylene group represented by the following formula (4), or a naphthylene group represented by the following formula (3) and a biphenylene group represented by the following formula (4). X is a divalent group, and X is a phenylene group represented by the following formula (2) and a biphenylene group represented by the following formula (4), or X is a naphthylene group represented by the following formula (3) and a biphenylene group represented by the following formula (4). The phenylene group, biphenylene group, and naphthylene group may have a substituent on each aromatic ring. 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-mentioned acyl group. Q is independently an acyl group having 2 to 20 carbon atoms or a hydrogen atom, and 5 mol % or more of Q is the above-mentioned acyl group. The compound represented by formula (6) may be a compound in which at least one Q is an acyl group, or a mixture of a compound in which at least one Q is an acyl group and a compound 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. 【Chemistry 4】 Here, in formulas (2) to (4), R is a substituent, i and k are integers of 0 to 4, and j is an integer of 0 to 6.

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 (8) with 1 mol of an alcoholic hydroxyl group equivalent of an epoxy resin represented by the following formula (7), to obtain a modified epoxy resin represented by the following formula (1) having an epoxy equivalent of 250 to 50,000 g / eq. 【Chemistry 5】 (In the formula, X is a divalent group, and X is a phenylene group represented by the following formula (2) or a biphenylene group represented by the following formula (4), or X is a naphthylene group represented by the following formula (3) or a biphenylene group represented by the following formula (4). The phenylene group, biphenylene group, and naphthylene group may have a substituent on each aromatic ring. L independently represents a hydrogen atom or a glycidyl group. Y independently represents a hydrogen atom, an acyl group having 2 to 20 carbon atoms, or a glycidyl group. Z independently represents 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. 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.) 【Chemistry 6】 Here, in formulas (2) to (4), R is a substituent, i and k are integers of 0 to 4, and j is an integer of 0 to 6.

11. A cured product obtained by curing the resin composition according to claim 6.

12. A laminate for electric / electronic circuits, which is obtained by using the resin composition according to claim 6.

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