Polyvalent hydroxy resins, epoxy resins, methods for producing them, epoxy resin compositions and cured products thereof

Abstract

To provide a polyvalent hydroxy resin and its epoxy resin that yield cured products exhibiting excellent dielectric loss tangent and adhesion. [Solution] A phenolic resin characterized by being represented by the following general formula (1). TIFF2026166567000024.tif34146 (In the formula, R 1 Each of these independently represents a hydrocarbon group having 1 to 8 carbon atoms, and R 3 Each of these independently represents a hydrogen atom, a dicyclopentenyl group, or a substituent or linking group containing a substituted or unsubstituted aromatic hydrocarbon group. n indicates the number of repetitions, with an average value between 0 and 5.

Description

[Technical Field]

[0001] The present invention relates to a polyvalent hydroxy resin or epoxy resin with excellent low dielectric properties, and a method for producing the same. [Background technology]

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

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

[0004] To date, dicyclopentadiene epoxy resins (Patent Documents 1 and 2) and aromatically modified dicyclopentadiene phenol resins (Patent Documents 3 and 4) have been proposed. However, in the field of electronic substrate materials, further improvements in dielectric properties are required. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2001-240654 [Patent Document 2] Japanese Patent Application Publication No. 5-339341 [Patent Document 3] Japanese Patent Publication No. 2016-69524 [Patent Document 4] WO2020 / 129724 [Overview of the project] PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] Accordingly, the problem to be solved by the present invention is to provide a polyvalent hydroxy resin capable of obtaining a cured product exhibiting excellent dielectric loss tangent and adhesion, an epoxy resin thereof, an epoxy resin composition using the same, and production methods thereof. MEANS FOR SOLVING THE PROBLEMS

[0007] As a result of various studies conducted by the present inventors to solve the above problems, it has been found that by further reacting a dicyclopentadiene-type phenol resin with an aralkyl compound in a specific ratio, a skeleton derived from the aralkyl compound can be added to the phenol ring of the dicyclopentadiene-type phenol resin, and further, when the epoxy resin obtained by epoxidizing this phenol resin is cured with a curing agent, the resulting cured product is excellent in low dielectric properties and adhesion, and the present invention has been completed.

[0008] That is, the present invention is a polyvalent hydroxy resin represented by the following general formula (1). CHEMICAL FORMULA (In the formula, R 1 each independently represents a hydrocarbon group having 1 to 8 carbon atoms, R 3 each independently represents a hydrogen atom, a dicyclopentenyl group represented by the following formula (1a) or formula (1b), or a group represented by formula (1c) or formula (1d), and at least one of R 3 is a group represented by formula (1c) or formula (1d). Ar represents a substituted or unsubstituted aromatic hydrocarbon group. * represents a residue obtained by removing one R 3 from formula (1). n represents the number of repetitions, and the average value thereof is a number of 0 to 5.)

[0009] The present invention is a method for producing a phenol resin, characterized by reacting a polyhydric hydroxy resin (a) represented by the following general formula (2) with an aralkyl compound (b) represented by the following general formula (3a) and / or general formula (3b).

Chemical Formula

Chemical Formula

[0010] The present invention is an epoxy resin characterized by being represented by the following general formula (4).

Chemical Formula

[0011] The present invention is an epoxy resin composition essentially containing the above polyhydric hydroxy resin and / or epoxy resin, a cured product of the epoxy resin composition, a prepreg, a resin sheet, a laminate, or a circuit board material.

Effects of the Invention

[0012] A cured product using the polyhydric hydroxy resin and / or epoxy resin of the present invention provides an epoxy resin composition that exhibits an excellent dielectric loss tangent.

Brief Description of the Drawings

[0013] [Figure 1] This is an IR chart of the phenol resin obtained in Example 1. [Figure 2] This is a GPC chart of the phenol resin obtained in Example 1. [Figure 3] This is the IR chart of the epoxy resin obtained in Example 9. [Figure 4] This is the GPC chart of the epoxy resin obtained in Example 9. [Modes for carrying out the invention]

[0014] The embodiments of the present invention will be described in detail below. The polyvalent hydroxy resin (also called phenolic resin) of the present invention is a polyvalent hydroxy resin represented by general formula (1). This resin can be obtained, for example, by reacting a dicyclopentadiene-type polyvalent hydroxy resin represented by general formula (2) with an aralkyl compound represented by general formula (3a) and / or general formula (3b) in the presence of an acid catalyst. Here, the polyvalent hydroxy resin represented by general formula (2) has a structure in which phenols are linked by dicyclopentadiene, and further, a dicyclopentenyl group represented by the above formula (2a) or (2b) may be attached to the phenol ring.

[0015] [ka] In general formula (1), R 1 The substituent represents a hydrocarbon group having 1 to 8 carbon atoms, and is preferably an alkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 8 carbon atoms, an aralkyl group having 7 to 8 carbon atoms, or an allyl group. The alkyl group having 1 to 8 carbon atoms can be linear, branched, or cyclic, and is not limited to, but includes, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an t-butyl group, a hexyl group, a cyclohexyl group, a methylcyclohexyl group, etc. The aryl group having 6 to 8 carbon atoms is not limited to, but includes, but includes, a phenyl group, a tolyl group, a xylyl group, an ethylphenyl group, etc. The aralkyl group having 7 to 8 carbon atoms is not limited to, but includes, but includes, a benzyl group, an α-methylbenzyl group, etc. Among these substituents, the phenyl group and the methyl group are preferred from the viewpoint of ease of availability and reactivity when cured, and the methyl group is particularly preferred.

[0016] R 3 Each of these independently represents a hydrogen atom, a dicyclopentenyl group represented by formula (1a) or formula (1b), a group represented by formula (1c), or a group represented by formula (1d), R 2 At least one of these is a group represented by formula (1c) or formula (1d). [ka] The group represented by formula (1c) is a group derived from the monoaralkyl compound represented by general formula (3a) among the aralkyl compounds (b), and the group represented by formula (1d) is a group derived from the dialkyl compound represented by general formula (3b) among the aralkyl compounds (b).

[0017] n is the repeating number, representing a number greater than or equal to 0, and its mean value (number mean) is between 0 and 5, preferably between 0.1 and 4.0, more preferably between 0.2 and 3.0, and even more preferably between 0.5 and 2.5.

[0018] In formula (1c) or formula (1d), Ar represents a substituted or unsubstituted aromatic hydrocarbon group. Examples of aromatic hydrocarbon groups include monocyclic aromatic compounds such as benzene, furan, pyrrole, thiophene, imidazole, pyrazole, oxazole, isoxazole, thiazole, isothiazole, pyridine, pyrimidine, pyridazine, pyrazine, and triazine; fused aromatic compounds such as naphthalene, anthracene, phenalene, phenanthrene, quinoline, isoquinoline, quinazoline, phthalazine, pteridine, coumarin, indole, benzimidazole, benzofuran, and acridine; and ring-assembled aromatic compounds such as biphenyl, binaphthalene, bipyridine, bithiophene, phenylpyridine, phenylthiophene, terphenyl, diphenylthiophene, and quaterphenyl. Preferably, it is benzene, naphthalene, biphenyl, or anthracene. Particularly preferred is benzene. The aromatic hydrocarbon group may be substituted with an alkyl group, such as a methyl group or an ethyl group. When using a diaralkyl compound represented by formula (3b) as a raw material, a leaving group X may be contained. In formula (1d), * represents a residue obtained by removing one R from formula (1) 3 .

[0019] The weight average molecular weight (Mw) of the phenolic resin of the present invention is preferably 400 to 2000, more preferably 700 to 1800. The number average molecular weight (Mn) is preferably 350 to 1500, more preferably 500 to 1000. The phenolic hydroxyl equivalent (g / eq.) is preferably 200 to 500, more preferably 250 to 450, and even more preferably 280 to 400. The softening point is preferably 50 to 180°C, more preferably 80 to 120°C.

[0020] The phenolic resin represented by the general formula (1) of the present invention can be suitably produced by reacting a polyhydric hydroxy resin (a) represented by the general formula (2) with an aralkyl compound (b) represented by the general formula (3a) and / or the general formula (3b).

Chemical Formula

[0021] The monoaralkyl compound represented by the general formula (3a) and the divinylaralkyl compound represented by the general formula (3b) may be used in combination. The larger the blending amount of the monoaralkyl compound, the higher the molecular weight of the polyhydric hydroxy resin (1). Therefore, the blending amount thereof may be adjusted while taking into consideration the molecular weight of the polyhydric hydroxy resin so as to achieve the target molecular weight. The monovinylaralkyl compound becomes the substituent (R represented by formula (1c) through an addition reaction 3 ), and exhibits the effect of reducing dielectric properties.

[0022] Examples of monoaralkyl compounds represented by formula (3a) include, for example, benzyl chloride, benzyl bromide, benzyl iodite, o-methylbenzyl chloride, m-methylbenzyl chloride, p-methylbenzyl chloride, p-ethylbenzyl chloride, p-isopropylbenzyl chloride, p-tert-butylbenzyl chloride, p-cyclohexylbenzyl chloride, p-phenylbenzyl chloride, α-methylbenzyl chloride, α Examples include α-dimethylbenzyl chloride, benzyl methyl ether, o-methylbenzyl methyl ether, m-methylbenzyl methyl ether, p-methylbenzyl methyl ether, p-ethylbenzyl methyl ether, benzyl ethyl ether, benzyl isopropyl ether, benzyl n-propyl ether, benzyl isobutyl ether, benzyl n-butyl ether, p-methylbenzyl methyl ether, benzyl alcohol, o-methylbenzyl alcohol, m-methylbenzyl alcohol, p-methylbenzyl alcohol, p-ethylbenzyl alcohol, p-isopropylbenzyl alcohol, p-tert-butylbenzyl alcohol, p-cyclohexylbenzyl alcohol, p-phenylbenzyl alcohol, α-methylbenzyl alcohol, α,α-dimethylbenzyl alcohol, etc. Preferably, benzyl chloride, benzyl alcohol, or benzyl methyl ether. These can be used individually or in combination of two or more.

[0023] Examples of dialkyl compounds represented by formula (3b) include, for example, 1,2-di(chloromethyl)benzene, 1,2-di(bromomethyl)benzene, 1,3-di(chloromethyl)benzene, 1,3-di(fluoromethyl)benzene, 1,4-di(chloromethyl)benzene, 1,4-di(bromomethyl)benzene, 1,4-di(fluoromethyl)benzene, 1,4-di(chloromethyl)-2,5-dimethylbenzene, 1,3-di(chloromethyl)-4,6-dimethylbenzene, 1,3-di(chloromethyl)-2,4-dimethylbenzene, and 4,4'-bis(chloromethyl) )biphenyl, 2,2'-bis(chloromethyl)biphenyl, 2,4'-bis(chloromethyl)biphenyl, 2,3'-bis(chloromethyl)biphenyl, 4,4'-bis(bromomethyl)biphenyl, 4,4'-bis(chloromethyl)diphenyl ether, 2,7-di(chloromethyl)naphthalene, p-xylylene glycol, m-xylene glycol, 1,4-di(2-hydroxy-2-ethyl)benzene, 4,4'-bis(dimethylol)biphenyl 2,4'-bis(dimethylol)biphenyl, 4,4'-bis(2-hydroxy-2-propyl)biphenyl, 2,4'-bis(2-hydroxy-2-propyl)biphenyl, 1,4'-di(methoxymethyl)benzene, 1,4'-di(ethoxymethyl)benzene, 1,4'-di(isopropoxy)benzene, 1,4'-di(butoxy)benzene, 1,3'-di(methoxymethyl)benzene, 1,3'-di(ethoxymethyl)benzene, 1,3'-di(isopropoxy)benzene, 1,3'-di(butoxy)benzene, 1,4-di(2-methoxy-2-ethyl)benzene, 1,4-di(2-hydroxy-2-ethyl)benzene, 1,4-di(2-ethoxy-2-ethyl)benzene, 4,4'-bis(methoxymethyl)biphenyl Lu, 2,4'-bis(methoxymethyl)biphenyl, 2,2'-bis(methoxymethyl)biphenyl, 2,3'-bis(methoxymethyl)biphenyl, 3,3'-bis(methoxymethyl)biphenyl, 3,4'-bis(methoxymethyl)biphenyl, 4,4'-bis(ethoxymethyl)biphenyl, 2,4'-bis(ethoxymethyl)biphenyl, 4,4'-bis(isopropoxy)methylbiphenyl, 2,Examples include 4'-bis(isopropoxy)methylbiphenyl, bis(1-methoxy-1-ethyl)biphenyl, bis(1-methoxy-1-ethyl)biphenyl, bis(1-isopropoxy-1-ethyl)biphenyl, bis(2-hydroxy-2-propyl)biphenyl, bis(2-methoxy-2-propyl)biphenyl, bis(2-isopropoxy-2-propyl)biphenyl, 1,3-bis(α-hydroxyisopropyl)benzene, 1,4-bis(α-hydroxyisopropyl)benzene, 1,3-bis(1-hydroxyethyl)benzene, and 1,4-bis(1-hydroxyethyl)benzene. These compounds may be used individually or in combination of two or more. Among these, from the viewpoint of industrial availability, it is more preferable to use, for example, p-xylylene glycol, m-xylene glycol, 1,3-bis(α-hydroxyisopropyl)benzene, and 1,4-bis(α-hydroxyisopropyl)benzene.

[0024] The polyvalent hydroxy resin (a) represented by general formula (2) is obtained by reacting dicyclopentadiene (structural formula below) with phenols represented by general formula (5) in the presence of a Lewis acid. [ka] Here, R1 is synonymous with the definition in general formula (1).

[0025] The polyvalent hydroxy resin (a) represented by general formula (2) obtained by these reactions has a phenolic hydroxyl group equivalent (g / eq.) of preferably 180 to 350, more preferably 190 to 320, and even more preferably 190 to 300.

[0026] Examples of phenols represented by formula (5) used as raw materials include dimethylphenol, diethylphenol, dipropylphenol, diisopropylphenol, di(n-butyl)phenol, di(t-butyl)phenol, dihexylphenol, dicyclohexylphenol, diphenylphenol, ditolylphenol, dibenzylphenol, bis(α-methylbenzyl)phenol, methylethylphenol, methylpropylphenol, methylisopropylphenol, methylbutylphenol, methyl-t-butylphenol, methylallylphenol, tolylphenylphenol, and the like. From the viewpoint of ease of availability and reactivity when cured, dimethylphenol and diphenylphenol are preferred, and dimethylphenol is particularly preferred.

[0027] The catalyst used in the reaction is a Lewis acid, such as boron trifluoride, boron trifluoride-phenol complex, boron trifluoride-ether complex, aluminum chloride, tin chloride, zinc chloride, iron chloride, etc., but boron trifluoride-ether complex is preferred due to its ease of handling. In the case of boron trifluoride-ether complex, the amount of catalyst used is 0.001 to 20 parts by mass, preferably 0.5 to 10 parts by mass, per 100 parts by mass of dicyclopentadiene.

[0028] The ratio of phenols to dicyclopentadiene in the reaction is 0.08 to 0.80 moles, preferably 0.09 to 0.70 moles, and more preferably 0.10 to 0.60 moles of dicyclopentadiene per mole of phenols.

[0029] The reaction is best carried out by charging phenols and a catalyst into a reactor and adding dicyclopentadiene dropwise over 0.1 to 10 hours, preferably 0.5 to 8 hours, and more preferably 1 to 6 hours.

[0030] The reaction temperature is preferably 50 to 200°C, more preferably 100 to 180°C, and even more preferably 120 to 160°C. The reaction time is preferably 1 to 10 hours, more preferably 3 to 10 hours, and even more preferably 4 to 8 hours.

[0031] After the reaction is complete, alkalis such as sodium hydroxide, potassium hydroxide, and calcium hydroxide are added to deactivate the catalyst. Then, solvents such as aromatic hydrocarbons like toluene and xylene, or ketones like methyl ethyl ketone and methyl isobutyl ketone are added to dissolve the catalyst. After washing with water, the solvent is recovered under reduced pressure to obtain the desired dicyclopentadienephenol resin represented by general formula (2). It is preferable to react as much of the dicyclopentadiene as possible and recover any unreacted phenolic raw materials under reduced pressure.

[0032] During the reaction, solvents such as aromatic hydrocarbons like benzene, toluene, and xylene, ketones like methyl ethyl ketone and methyl isobutyl ketone, halogenated hydrocarbons like chlorobenzene and dichlorobenzene, and ethers like ethylene glycol dimethyl ether and diethylene glycol dimethyl ether may be used as needed.

[0033] A reaction method for introducing an aralkyl structure of formula (1c) or formula (1d) into a polyvalent hydroxy resin represented by general formula (2) is to react the polyvalent hydroxy resin (2) with a monoaralkyl compound (3a) and / or a dialkyl compound (3b) in a predetermined ratio. The reaction ratio is preferably 0.05 to 2.0 moles, more preferably 0.3 to 1.8 moles, and even more preferably 0.4 to 1.6 moles, of the combined monoaralkyl compound (3a) and dialkyl compound (3b) per mole of phenolic hydroxyl groups of the polyvalent hydroxy resin (2). When using both a monoaralkyl compound and a dialkyl compound, the ratio of the monoaralkyl compound (3a) to the dialkyl compound (3b) should be 1 to 99% by mass of the monoaralkyl compound and 1 to 99% by mass of the dialkyl compound, relative to the total amount of the aralkyl compound. The softening point of the resulting phenolic resin increases with the amount of dialkyl compound used, making it possible to control the softening point by adjusting the amount used.

[0034] The catalyst used in the reaction is an acid catalyst, specifically including mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; organic acids such as formic acid, oxalic acid, trifluoroacetic acid, and p-toluenesulfonic acid; Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride; or solid acids such as activated clay, silica-alumina, and zeolite. Among these, p-toluenesulfonic acid is preferred due to its ease of handling. In the case of p-toluenesulfonic acid, the amount of catalyst used is 0.001 to 20 parts by mass, preferably 0.5 to 10 parts by mass, per 100 parts by mass of polyvalent hydroxy resin (2).

[0035] The reaction is preferably carried out by charging the polyvalent hydroxy resin (2) and the dialkyl compound (3b) into a reactor, dissolving them, and then gradually adding the monoaralkyl compound (3a) dropwise over 0.1 to 10 hours, preferably 0.5 to 8 hours, and more preferably 0.5 to 5 hours.

[0036] The reaction temperature is preferably 50 to 200°C, more preferably 100 to 180°C, and even more preferably 120 to 160°C. The reaction time is preferably 1 to 10 hours, more preferably 3 to 10 hours, and even more preferably 4 to 8 hours.

[0037] After the reaction is complete, alkalis such as sodium hydroxide, potassium hydroxide, and calcium hydroxide are added to deactivate the catalyst. Then, solvents such as aromatic hydrocarbons like toluene and xylene, or ketones like methyl ethyl ketone and methyl isobutyl ketone are added to dissolve the catalyst. After washing with water, the solvent is recovered under reduced pressure to obtain the desired phenolic resin.

[0038] The solvents used in the reaction include aromatic hydrocarbons such as benzene, toluene, and xylene; ketones such as methyl ethyl ketone and methyl isobutyl ketone; halogenated hydrocarbons such as chlorobenzene and dichlorobenzene; and ethers such as ethylene glycol dimethyl ether and diethylene glycol dimethyl ether. These solvents may be used individually or in mixtures of two or more.

[0039] The epoxy resin of the present invention is represented by general formula (4). [ka] In general formula (4), R 1 , R 3 ,Ar, and * are equivalent to their definitions in general formula (1), and m is equivalent to n in general formula (1).

[0040] The epoxy resin represented by general formula (4) of the present invention is obtained by reacting a polyvalent hydroxy resin represented by general formula (1) with an epihalohydrin such as epichlorohydrin (structural formula below). This reaction is carried out according to conventionally known methods. [ka]

[0041] For example, epoxidation can be performed by adding an alkali metal hydroxide such as sodium hydroxide in solid or concentrated aqueous form to a mixture of phenol resin and an excess molar amount of epihalohydrin relative to the hydroxyl groups of the phenol resin, and reacting the mixture at a reaction temperature of 30 to 120°C for 0.5 to 10 hours, or by adding a quaternary ammonium salt such as tetraethylammonium chloride as a catalyst to a phenol resin and an excess molar amount of epihalohydrin, reacting the mixture at a temperature of 50 to 150°C for 1 to 5 hours, and then adding an alkali metal hydroxide such as sodium hydroxide in solid or concentrated aqueous form to the resulting polyhalohydrin ether and reacting the mixture at a temperature of 30 to 120°C for 1 to 10 hours.

[0042] In the reaction, the amount of epihalohydrin used is 1 to 20 times the molar amount relative to the hydroxyl groups of the phenol resin, preferably 2 to 8 times the molar amount. The amount of alkali metal hydroxide used is 0.85 to 1.15 times the molar amount relative to the hydroxyl groups of the phenol resin.

[0043] The epoxy resin obtained from the reaction contains unreacted epihalohydrin and alkali metal halides. Therefore, the unreacted epihalohydrin can be removed from the reaction mixture by evaporation, and the alkali metal halides can be removed by methods such as extraction with water or filtration to obtain the desired epoxy resin.

[0044] The epoxy resin represented by general formula (4) of the present invention preferably has an epoxy equivalent (g / eq.) of 200 to 4000, more preferably 220 to 2000, and even more preferably 250 to 700. In particular, when dicyandiamide is used as a curing agent, it is preferable that the epoxy equivalent be 300 or more in order to prevent the precipitation of dicyandiamide crystals on the prepreg. The total chlorine content is preferably 2000 ppm or less, and more preferably 1500 ppm or less.

[0045] An epoxy resin composition of the present invention can be obtained by using the polyvalent hydroxy resin and / or the epoxy resin of the present invention. The epoxy resin composition of the present invention comprises an epoxy resin and a curing agent as essential components. In this embodiment, part or all of the curing agent is the polyvalent hydroxy resin of the present invention, part or all of the epoxy resin is the epoxy resin of the present invention, or part or all of the curing agent is the polyvalent hydroxy resin of the present invention and part or all of the epoxy resin is the epoxy resin of the present invention.

[0046] Preferably, at least 30% by mass of the curing agent is the polyvalent hydroxy resin of the present invention, or at least 30% by mass of the epoxy resin is the epoxy resin of the present invention. More preferably, each is contained at 50% by mass or more, and even more preferably at 70% by mass. If the amount is less than this, the dielectric properties may deteriorate. In other words, if 30% by mass or more of the curing agent is the polyvalent hydroxy resin of the present invention, the epoxy resin does not need to be the epoxy resin of the present invention, and if the polyvalent hydroxy resin of the present invention is less than 30% by mass of the curing agent, it is essential that 30% by mass or more of the epoxy resin is the epoxy resin of the present invention.

[0047] As the epoxy resin used to obtain the epoxy resin composition of the present invention, one or more types of epoxy resins may be used in combination as needed.

[0048] Any conventional epoxy resin having two or more epoxy groups in its molecule can be used in combination with this product. For example, trifunctional epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, tetramethylbisphenol F type epoxy resin, hydroquinone type epoxy resin, biphenyl type epoxy resin, stilbene type epoxy resin, bisphenol fluorene type epoxy resin, bisphenol S type epoxy resin, bisthioether type epoxy resin, resorcinol type epoxy resin, biphenyl aralkylphenol type epoxy resin, naphthalenediol type epoxy resin, phenol novolac type epoxy resin, aromatic modified phenol novolac type epoxy resin, cresol novolac type epoxy resin, alkyl novolac type epoxy resin, bisphenol novolac type epoxy resin, binaphthol type epoxy resin, naphthol novolac type epoxy resin, β-naphthol aralkyl type epoxy resin, dinaphthol aralkyl type epoxy resin, α-naphthol aralkyl type epoxy resin, trisphenylmethane type epoxy resin, and tetrafunctional epoxy resins such as tetrakisphenylethane type epoxy resin. Other examples of epoxy resins include, but are not limited to, dicyclopentadiene-type epoxy resins, polyhydric alcohol polyglycidyl ethers such as 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, trimethylolethane polyglycidyl ether, and pentaerythritol polyglycidyl ether; alkylene glycol-type epoxy resins such as propylene glycol diglycidyl ether; aliphatic cyclic epoxy resins such as cyclohexanedimethanol diglycidyl ether; glycidyl esters such as dimer acid polyglycidyl esters; glycidylamine-type epoxy resins such as phenyl diglycidylamine, tol diglycidylamine, diaminodiphenylmethane tetraglycidylamine, and aminophenol-type epoxy resins; alicyclic epoxy resins such as Celoxide 2021P (manufactured by Daicel Corporation); phosphorus-containing epoxy resins; bromine-containing epoxy resins; urethane-modified epoxy resins; and oxazolidone ring-containing epoxy resins. These epoxy resins may be used individually or in combination of two or more types.

[0049] As a curing agent, in addition to the polyvalent hydroxy resin (A) of general formula (1), one or more commonly used curing agents such as various phenolic resins, acid anhydrides, amines, cyanate esters, activated esters, hydrazides, acidic polyesters, and aromatic cyanates may be used in combination as needed. When these curing agents are used in combination, the amount of the combined curing agent is preferably 70% by mass or less, and more preferably 50% by mass or less, of the total curing agent. If the proportion of the combined curing agent is too high, the dielectric properties of the epoxy resin composition may deteriorate.

[0050] In the epoxy resin composition of the present invention, the molar ratio of active hydrogen groups of the curing agent to 1 mole of epoxy groups of the total epoxy resin is preferably 0.2 to 1.5 moles, more preferably 0.3 to 1.4 moles, even more preferably 0.5 to 1.3 moles, and particularly preferably 0.8 to 1.2 moles. If the ratio deviates from this range, curing may be incomplete, and good cured properties may not be obtained. For example, when using a phenol resin-based curing agent or an amine-based curing agent, the active hydrogen groups are blended in approximately equimolar amounts to the epoxy groups. When using an acid anhydride-based curing agent, the acid anhydride groups are blended in an amount of 0.5 to 1.2 moles, preferably 0.6 to 1.0 moles, per mole of epoxy groups. When using the phenol resin of the present invention alone as a curing agent, it is desirable to use it in a range of 0.9 to 1.1 moles per mole of epoxy resin.

[0051] The epoxy resin composition of the present invention may use known and conventional epoxy resin curing accelerators as needed. Examples of usable curing accelerators include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 2-heptadecylimidazole, and 2-undecylimidazole; tertiary amines such as 4-dimethylaminopyridine, 2-(dimethylaminomethyl)phenol, and 1,8-diazabicyclo(5,4,0)undecene-7; and 3-phenyl-1,1-dimethylurea and 3-(4-methylphenyl)-1,1 Examples of curing accelerators include urea compounds such as -dimethylurea, chlorophenylurea, 3-(4-chlorophenyl)-1,1-dimethylurea, and 3-(3,4-dichlorophenyl)-1,1-dimethylurea; phosphines such as triphenylphosphine, tributylphosphine, tricyclohexylphosphine, triphenylphosphine, and triphenylborane; quaternary phosphonium salts such as TBP-DA, TBP-3PC, TBP-3S, and TPP-phthalic acid manufactured by Hokko Chemical Industry Co., Ltd.; and metal compounds such as tin octylate. These curing accelerators may be used alone or in combination of two or more types.

[0052] When using a curing accelerator, the amount used can be appropriately selected depending on the purpose of use, but 0.01 to 15 parts by mass are used as needed, preferably 0.02 to 10 parts by mass, more preferably 0.05 to 8 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of epoxy resin component in the epoxy resin composition. By using a curing accelerator, the curing temperature can be lowered and the curing time can be shortened.

[0053] A wide range of known organic solvents or reactive diluents can be used in epoxy resin compositions to adjust their viscosity.

[0054] Examples of organic solvents include, but are not limited to, N,N-dimethylformamide ethers, ketones such as acetone, alcohols such as methanol, acetate esters such as butyl acetate, benzoic acid esters such as methyl benzoate, cellosolves such as methyl cellosolve, carbitols such as methyl carbitol, aromatic hydrocarbons such as benzene and toluene, dimethyl sulfoxide, acetonitrile, and N-methylpyrrolidone.

[0055] Examples of reactive diluents include, but are not limited to, monofunctional glycidyl ethers such as 2-ethylhexylglycidyl ether and monofunctional glycidyl esters such as neodecanoic acid glycidyl ester.

[0056] These organic solvents or reactive diluents are preferably used in the resin composition, either individually or in mixtures of several types, at a non-volatile content of 90% by mass or less, and the appropriate type and amount are selected as appropriate depending on the application. For example, in printed circuit board applications, polar solvents with a boiling point of 160°C or less, such as methyl ethyl ketone, acetone, and 1-methoxy-2-propanol, are preferred, and the amount used in the resin composition is preferably 40 to 80% by mass in terms of non-volatile content. In adhesive film applications, for example, ketones, acetate esters, carbitols, aromatic hydrocarbons, dimethylformamide, dimethylacetamide, and N-methylpyrrolidone are preferred, and the amount used is preferably 30 to 60% by mass in terms of non-volatile content.

[0057] The epoxy resin composition may contain other thermosetting resins or thermoplastic resins to the extent that it does not impair the properties. Examples include, but are not limited to, phenolic resins, benzoxazine resins, bismaleimide resins, bismaleimidotriazine resins, acrylic resins, petroleum resins, indene resins, coumarone indene resins, phenoxy resins, polyurethane resins, polyester resins, polyamide resins, polyimide resins, polyamideimide resins, polyetherimide resins, polyphenylene ether resins, modified polyphenylene ether resins, polyethersulfone resins, polysulfone resins, polyetheretherketone resins, polyphenylene sulfide resins, polyvinyl formal resins, polysiloxane compounds, and alkylene resins containing reactive functional groups such as hydroxyl group-containing polybutadiene.

[0058] Various known flame retardants can be used in the epoxy resin composition to improve the flame retardancy of the resulting cured product. Examples of usable flame retardants include halogen-based flame retardants, phosphorus-based flame retardants, nitrogen-based flame retardants, silicone-based flame retardants, inorganic flame retardants, and organometallic salt-based flame retardants. From an environmental standpoint, halogen-free flame retardants are preferred, and phosphorus-based flame retardants are particularly preferred. These flame retardants may be used individually or in combination of two or more types.

[0059] The amount of flame retardant added is appropriately selected depending on the type of phosphorus-based flame retardant, the components of the epoxy resin composition, and the desired degree of flame retardancy. For example, the phosphorus content in the organic components (excluding organic solvents) of the epoxy resin composition is preferably 0.2 to 5% by mass.

[0060] Fillers may be used in the epoxy resin composition as needed. Specifically, examples include fused silica, crystalline silica, alumina, silicon nitride, aluminum hydroxide, boehmite, magnesium hydroxide, talc, mica, calcium carbonate, calcium silicate, calcium hydroxide, magnesium carbonate, barium carbonate, barium sulfate, boron nitride, carbon, carbon fiber, glass fiber, alumina fiber, silica-alumina fiber, silicon carbide fiber, polyester fiber, cellulose fiber, aramid fiber, ceramic fiber, fine particle rubber, silicone rubber, thermoplastic elastomer, carbon black, and pigments. The amount of these fillers added is, for example, 1 to 200% by mass of the total epoxy resin composition.

[0061] The epoxy resin composition may further contain various additives as needed, such as silane coupling agents, antioxidants, mold release agents, defoaming agents, emulsifiers, thixotropy-inducing agents, smoothing agents, flame retardants, and pigments. The amount of these additives added is preferably in the range of 0.01 to 20% by mass relative to the epoxy resin composition.

[0062] Epoxy resin compositions can be used to create prepregs for printed circuit boards and the like by impregnating them with fibrous substrates. As fibrous substrates, for example, inorganic fibers such as glass, or woven or nonwoven fabrics of organic fibers such as polyester resin, polyamine resin, polyacrylic resin, polyimide resin, and aromatic polyamide resin can be used. One method for producing a prepreg involves immersing an epoxy resin composition in a resin varnish prepared by adjusting its viscosity with an organic solvent, impregnating it, and then heating and drying it to partially cure (B-stage) the resin component. For example, it can be heated and dried at 100-200°C for 1-40 minutes. The amount of resin in the prepreg is preferably 30-80% by mass.

[0063] To cure the prepreg, known lamination curing methods commonly used in the manufacture of printed circuit boards can be used. For example, when forming a laminate using a prepreg, one or more prepregs are stacked, metal foil is placed on one or both sides to form a laminate, and this laminate is heated and pressurized to integrate the layers. As the metal foil, single, alloy, or composite metal foils of copper, stainless steel, titanium, aluminum, brass, nickel, etc. can be used. By pressurizing and heating the prepared laminate, the prepreg is cured and a laminate can be obtained.

[0064] The epoxy resin composition can be molded using known methods, such as casting, injection, potting, dipping, drip coating, transfer molding, and compression molding. The curing conditions can also be known conditions, such as a heating temperature of 100 to 300°C, preferably 160 to 220°C, a pressure of 5 to 50 MPa, and a curing time of 30 minutes to 6 hours.

[0065] The epoxy resin cured product of the present invention can take the form of a laminate, molded product, adhesive product, coating film, film, or the like. [Examples]

[0066] The present invention will be specifically described with reference to examples and comparative examples, but the present invention is not limited to these. The measurement methods were as follows.

[0067] • Hydroxyl group equivalent: Measurements were performed in accordance with JIS K 0070 standard, and the unit is expressed as "g / eq.". Unless otherwise specified, the hydroxyl group equivalent of phenolic resin refers to the phenolic hydroxyl group equivalent. ·Softening point: Measurements were taken in accordance with the JIS K 7234 standard and the ring-sphere method. Specifically, an automatic softening point device (ASP-MG4, manufactured by Maytec Co., Ltd.) was used. • Epoxy equivalent: Measurements were performed in accordance with JIS K 7236 standard, and the unit is expressed as "g / eq.". Specifically, an automatic potentiometric titrator (Hiranuma Sangyo Co., Ltd., COM-1600ST) was used, chloroform was used as the solvent, tetraethylammonium brominated acetate solution was added, and titration was performed with 0.1 mol / L perchloric acid-acetic acid solution. • Total chlorine: The measurement was performed in accordance with JIS K7243-3 standard. Specifically, 1.0 g of the sample was dissolved in 25 mL of butyl carbitol, then 25 mL of 1N-KOH propylene glycol solution was added, and the mixture was heated under reflux for 10 minutes. After cooling to room temperature, 100 mL of 80% aqueous acetone was added, and the measurement was performed by potentiometric titration with 0.002 N-AgNO3 aqueous solution. • Melt viscosity: The melt viscosity at 150°C was measured using an ICI viscosity analyzer (CV-1S, manufactured by Toa Kogyo Co., Ltd.).

[0068] • Relative permittivity and dielectric loss tangent: The relative permittivity (ε1) and dielectric loss tangent (Tanδ1) of a resin sample (test specimen) at a frequency of 10 GHz were measured using a vector network analyzer (Keysight Technologies, product name: Vector Network Analyzer E8363C) and an SPDR resonator. • Glass transition temperature (Tg): In accordance with IPC-TM-650 2.4.25.c, the temperature was expressed as DSC·Tgm (the temperature midway between the displacement curves relative to the tangents of the glassy and rubbery states) when measured using a differential scanning calorimetry system (Hitachi High-Tech Science Co., Ltd., EXSTAR6000 DSC6200) under a heating condition of 20°C / min. ·Interlayer adhesion: The interlayer adhesion strength was measured in accordance with JIS C 6481, by peeling the material between the 7th and 8th layers.

[0069] • GPC (Gel Permeation Chromatography) measurement: The main unit (manufactured by Tosoh Corporation, HLC-8220GPC) is fitted with a column (manufactured by Tosoh Corporation, TSKgel G4000H) XL TSKgel G3000HXL TSKgel G2000H XL A column with two columns in series was used, and the column temperature was set to 40°C. Tetrahydrofuran (THF) was used as the eluent at a flow rate of 1 mL / min, and a differential refractive index detector was used. For the measurement sample, 0.1 g of the sample was dissolved in 10 mL of THF, filtered through a microfilter, and 50 μL of the result was used. Mw and Mn were determined by conversion from a calibration curve obtained from standard polystyrene (PStQuick Kit-H, manufactured by Tosoh Corporation). Data processing was performed using Tosoh Corporation's GPC-8020 Model II version 6.00. ·IR: Using a Fourier transform infrared spectrophotometer (Perkin Elmer Precisely, Spectrum One FT-IR Spectrometer 1760X) and a diamond ATR, the wavenumber range was 650-4000 cm. -1 The absorbance was measured. ·ESI-MS: Mass spectrometry was performed using a mass spectrometer (Shimadzu Corporation, LCMS-2020) with acetonitrile and water as the mobile phases, by measuring the sample dissolved in acetonitrile.

[0070] The abbreviations used in the examples and comparative examples are as follows: [Epoxy resin] E1: Epoxy resin obtained in Example 9 E2: Epoxy resin obtained in Example 10 E3: Epoxy resin obtained in Example 11 E4: Epoxy resin obtained in Example 12 E5: Epoxy resin obtained in Example 13 E6: Epoxy resin obtained in Example 14 E7: Epoxy resin obtained in Example 15 E8: Epoxy resin obtained in Example 16 EH1: Epoxy resin obtained in synthesis example 5 EH2: Epoxy resin obtained in synthesis example 6 EH3: Epoxy resin obtained in Synthesis Example 7 EH4: Epoxy resin obtained in synthesis example 8 [Hardening agent] P1: Phenolic resin obtained in Example 1 P2: Phenolic resin obtained in Example 2 P3: Phenolic resin obtained in Example 3 P4: Phenolic resin obtained in Example 4 P5: Phenolic resin obtained in Example 5 P6: Phenolic resin obtained in Example 6 P7: Phenolic resin obtained in Example 7 P8: Phenolic resin obtained in Example 8 PH1: Phenolic resin obtained in Synthesis Example 1 PH2: Phenolic resin obtained in Synthesis Example 2 PH3: Phenolic resin obtained in Synthesis Example 3 PH4: Phenolic resin obtained in Synthesis Example 4 PH5: Phenol novolac resin (manufactured by Aica Kogyo Co., Ltd., Shownol BRG-557, hydroxyl group equivalent 105, softening point 80°C, melt viscosity at 150°C 0.30 Pa·s) A1: Active ester resin obtained in Reference Example 1 [Curing accelerator] C1:2E4MZ:2-Ethyl-4-methylimidazole (manufactured by Shikoku Chemicals Co., Ltd., Curesol 2E4MZ) C2:4-Dimethylaminopyridine (manufactured by Kishida Chemical Co., Ltd.)

[0071] Synthesis Example 1 A reaction apparatus consisting of a glass separable flask equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser is used to add 2,6-xylenol (structural formula below). [ka] 500 parts of 47% BF3 ether complex (7.3 parts) were charged and heated to 100°C while stirring. While maintaining the same temperature, dicyclopentadiene (structural formula below) was added. [ka] 67.6 parts (0.12 molars relative to 2,6-xylenol) were added dropwise over 1 hour. The mixture was then reacted at 115-125°C for 4 hours, and 11 parts of calcium hydroxide were added. Further, 19 parts of a 10% oxalic acid aqueous solution were added. Afterward, the mixture was heated to 160°C to dehydrate it, and then heated to 200°C under reduced pressure of 5 mmHg to evaporate and remove any unreacted starting materials. 1320 parts of methyl isobutyl ketone (MIBK) were added to dissolve the product, and 400 parts of 80°C water were added for washing, after which the lower layer of water was separated and removed. Finally, MIBK was evaporated and removed under reduced pressure of 5 mmHg to 160°C to obtain 164 parts of a reddish-brown aromatic hydroxy compound (pH 1). The obtained aromatic hydroxy compound (PH1) had a hydroxyl group equivalent of 195 and a softening point of 73°C. The aromatic hydroxy compound is represented by formula (2), and R 1 is a methyl group, R 2 The atoms were hydrogen atoms, with Mw being 470, Mn being 440, and the average value of n being 1.08. Mass spectroscopy using ESI-MS (negative) revealed M-=375 and 629.

[0072] Synthesis Example 2 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of 2,6-xylenol and 1.30 parts of 47% BF3 ether complex (1.6 parts by mass per 100 parts by mass of dicyclopentadiene) were charged and heated to 100°C with stirring. While maintaining the same temperature, 81.2 parts of dicyclopentadiene (0.75 molars relative to 2,6-xylenol) were added dropwise over 1 hour. The reaction was then continued at a temperature of 115-125°C for 4 hours. After that, the mixture was heated to 200°C under reduced pressure of 5 mmHg to evaporate and remove unreacted starting materials, and 2.0 parts of calcium hydroxide were added. Further, 3.5 parts of 10% oxalic acid aqueous solution were added. 180 parts of MIBK were added to dissolve the product, and 55 parts of 80°C warm water were added for washing, separating and removing the lower aqueous layer. The mixture was heated to 120°C, refluxed, and filtered. After that, MIBK was evaporated and removed under reduced pressure of 5 mmHg at 160°C to obtain 134 parts of a reddish-brown hydroxy resin (pH 2). The obtained hydroxy resin (PH2) had a hydroxyl group equivalent of 278 and was a semi-solid resin at room temperature. The hydroxy resin is represented by formula (2), and R1 is a methyl group, R 2 R consists of a hydrogen atom and a dicyclopentenyl group. 2 One of the compounds was dicyclopentadiene, with a GPC value of 285 for Mw, 244 for Mn, and an average n value of 0.40. Mass spectra measured by ESI-MS (negative) revealed M- values ​​of 253, 375, 507, 629, and 639.

[0073] Synthesis Example 3 In a reaction apparatus similar to that used in Synthesis Example 1, 400 parts of phenol and 7.5 parts of 47% BF3 ether complex were charged and heated to 70°C with stirring. While maintaining the same temperature, 70.2 parts of dicyclopentadiene were added dropwise over 2 hours. The reaction was further carried out at 125-135°C for 4 hours, and 11.7 parts of calcium hydroxide were added. Then, 20 parts of 10% oxalic acid aqueous solution were added. After that, the mixture was heated to 160°C to dehydrate it, and then heated to 200°C under reduced pressure of 5 mmHg to evaporate and remove unreacted starting materials. 1100 parts of MIBK were added to dissolve the product, and 330 parts of 80°C warm water were added for washing, and the lower layer of water was separated and removed. Then, under reduced pressure of 5 mmHg, the mixture was heated to 160°C to evaporate and remove MIBK, yielding 158 parts of a reddish-brown aromatic hydroxy compound (PH3). The hydroxyl group equivalent was 177, and the softening point was 92°C. Aromatic hydroxy compounds represented by formula (2), where R 1 , R 2 The atoms were hydrogen atoms, n was 1.3, Mw was 460 and Mn was 390 according to GPC.

[0074] Example 1 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (pH 1) obtained in Synthesis Example 1 were added to 1.6 parts of p-toluenesulfonic acid monohydrate (1 phr relative to the total amount of pH 1 and benzyl alcohol) dissolved in 14.0 parts of water. The mixture was heated to 160°C and stirred to dehydrate it. Benzyl alcohol (structural formula below) [ka] 55.5 parts (1.0 equivalent relative to the hydroxyl groups at pH 1) were added over 30 minutes and reacted at 160°C for 4 hours. 230 parts of MIBK were added to dissolve the product, neutralized with 1.4 parts of sodium bicarbonate, and washed with 80 parts of 80°C water to separate and remove the lower layer of water. Then, under reduced pressure of 5 mmHg, the mixture was heated to 180°C to evaporate and remove the MIBK, yielding 139 parts of reddish-brown phenolic resin (P1). The hydroxyl group equivalent was 293, and the softening point was 93°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 375, 465, 555, 629, 645, 719, and 735. The IR of the obtained phenolic resin (P1) is shown in Figure 1, and the GPC is shown in Figure 2. The Mw value in the GPC was 720, and the Mn value was 630. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 Ar has a group represented by formula (1c) of benzene, and the average value of n was 1.09.

[0075] Example 2 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH1) obtained in Synthesis Example 1 were added to 1.8 parts of p-toluenesulfonic acid monohydrate (1 phr relative to the total amount of PH1 and benzyl alcohol) dissolved in 16.5 parts of water. The mixture was heated to 160°C and stirred to dehydrate it. 83.2 parts of benzyl alcohol (1.5 equivalents relative to the hydroxyl groups of PH1) were added over 30 minutes, and the mixture was reacted at 160°C for 4 hours. 280 parts of MIBK were added to dissolve the product, neutralized with 1.6 parts of sodium bicarbonate, and washed with 90 parts of 80°C warm water. The lower layer of water was separated and removed. Subsequently, the mixture was heated to 180°C under reduced pressure of 5 mmHg to evaporate and remove the MIBK, yielding 161 parts of reddish-brown phenolic resin (P2). The hydroxyl group equivalent was 354, and the softening point was 87°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 375, 465, 555, 629, 645, 719, and 735. GPC showed Mw of 740 and Mn of 590. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3Ar has a group represented by formula (1c) of benzene, and the average value of n was 1.10.

[0076] Example 3 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH1) obtained in Synthesis Example 1 and paraxylene glycol (structural formula below) were added. [ka] 3.5 parts (0.1 equivalents per hydroxyl group at pH 1) of p-toluenesulfonic acid monohydrate dissolved in 16.8 parts of water was added (1 phr relative to the total amount of pH 1, paraxylene glycol, and benzyl alcohol), and the mixture was heated to 160°C and stirred to dehydrate. 83.2 parts of benzyl alcohol (1.5 equivalents per hydroxyl group at pH 1) were added over 30 minutes, and the mixture was reacted at 160°C for 4 hours. 280 parts of MIBK were added to dissolve the product, neutralized with 1.6 parts of sodium bicarbonate, and washed with 90 parts of 80°C water to separate and remove the lower layer of water. Then, under reduced pressure of 5 mmHg, the mixture was heated to 180°C to evaporate and remove the MIBK, yielding 162 parts of reddish-brown phenolic resin (P3). The hydroxyl group equivalent was 372, and the softening point was 94°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 375, 465, 555, 629, 645, 719, and 735. GPC showed Mw to be 970 and Mn to be 640. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 The group had Ar represented by formula (1c) and Ar represented by formula (1d) of benzene, and the average value of n was 1.10.

[0077] Example 4 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH2) obtained in Synthesis Example 2, 9.9 parts of paraxylene glycol (0.4 equivalents relative to the hydroxyl groups of PH2), and 1.1 parts of p-toluenesulfonic acid monohydrate dissolved in 9.9 parts of water (1 phr relative to the total amount of PH2 and paraxylene glycol) were added. The mixture was heated to 160°C and stirred to dehydrate it. The reaction was carried out at 160°C for 4 hours. 170 parts of MIBK were added to dissolve the product, neutralized with 1.0 part of sodium bicarbonate, and washed with 50 parts of 80°C water. The lower layer of water was separated and removed. Then, under reduced pressure of 5 mmHg, the mixture was heated to 180°C to evaporate and remove the MIBK, yielding 98 parts of reddish-brown phenolic resin (P4). The hydroxyl group equivalent was 299, and the softening point was 101°C. Mass spectrometry using ESI-MS (negative) revealed M- values ​​of 253, 375, 385, 507, 609, and 741. GPC showed Mw to be 1240 and Mn to be 640. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 Ar had a group represented by formula (1d) of benzene, and the average value of n was 1.00.

[0078] Example 5 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH2) obtained in Synthesis Example 2, 12.4 parts of paraxylene glycol (0.5 equivalents relative to the hydroxyl groups of PH2), and 1.1 parts of p-toluenesulfonic acid monohydrate dissolved in 10.1 parts of water (1 phr relative to the total amount of PH2 and paraxylene glycol) were added. The mixture was heated to 160°C and stirred to dehydrate it. The reaction was carried out at 160°C for 4 hours. 170 parts of MIBK were added to dissolve the product, neutralized with 1.0 part of sodium bicarbonate, and washed with 50 parts of 80°C water. The lower layer of water was separated and removed. Then, under reduced pressure of 5 mmHg, the mixture was heated to 180°C to evaporate and remove the MIBK, yielding 98 parts of a reddish-brown phenolic resin (P5). The hydroxyl group equivalent was 315, and the softening point was 119°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 253, 375, 385, 507, 609, and 741. GPC showed Mw to be 1660 and Mn to be 770. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 Ar has a group represented by formula (1d) for benzene, and the average value of n was 1.12.

[0079] Example 6 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH2) obtained in Synthesis Example 2, 7.5 parts of paraxylene glycol (0.3 equivalents relative to the hydroxyl groups of PH2), and 1.2 parts of p-toluenesulfonic acid monohydrate dissolved in 11.1 parts of water (1 phr relative to the total amount of PH2, paraxylene glycol, and benzyl alcohol) were added, and the mixture was heated to 160°C and stirred to dehydrate. 15.6 parts of benzyl alcohol (0.4 equivalents relative to the hydroxyl groups of PH2) were added over 30 minutes, and the mixture was reacted at 160°C for 4 hours. 190 parts of MIBK were added to dissolve the product, neutralized with 1.1 parts of sodium bicarbonate, and washed with 60 parts of 80°C water. The lower layer of water was separated and removed. Then, under reduced pressure of 5 mmHg, the mixture was heated to 180°C to evaporate and remove the MIBK, yielding 109 parts of reddish-brown phenolic resin (P6). The hydroxyl group equivalent was 334, and the softening point was 83°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 253, 343, 375, 385, 433, 465, 475, 507, 555, 597, 609, 687, 699, and 741. GPC showed Mw at 960 and Mn at 540. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 The group had Ar represented by formula (1c) and Ar represented by formula (1d) of benzene, and the average value of n was 0.68.

[0080] Example 7 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH2) obtained in Synthesis Example 2, 7.5 parts of paraxylene glycol (0.3 equivalents relative to the hydroxyl groups of PH2), and 1.3 parts of p-toluenesulfonic acid monohydrate dissolved in 11.1 parts of water (1 phr relative to the total amount of PH2, paraxylene glycol, and benzyl alcohol) were added, and the mixture was heated to 160°C and stirred to dehydrate it. 23.3 parts of benzyl alcohol (0.6 equivalents relative to the hydroxyl groups of PH2) were added over 30 minutes, and the mixture was reacted at 160°C for 4 hours. 200 parts of MIBK were added to dissolve the product, neutralized with 1.2 parts of sodium bicarbonate, and washed with 60 parts of 80°C water to separate and remove the lower layer of water. Subsequently, the mixture was heated to 180°C under reduced pressure of 5 mmHg to evaporate and remove the MIBK, yielding 115 parts of reddish-brown phenolic resin (P7). The hydroxyl group equivalent was 347, and the softening point was 89°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 253, 343, 375, 385, 433, 465, 475, 507, 555, 597, 609, 687, 699, and 741. GPC showed Mw to be 1020 and Mn to be 580. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 The group had Ar represented by formula (1c) and Ar represented by formula (1d) of benzene, and the average value of n was 0.71.

[0081] Example 8 In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (PH2) obtained in Synthesis Example 2, 9.9 parts of paraxylene glycol (0.4 equivalents relative to the hydroxyl groups of PH2), and 1.3 parts of p-toluenesulfonic acid monohydrate dissolved in 12.0 parts of water (1 phr relative to the total amount of PH2, paraxylene glycol, and benzyl alcohol) were added, and the mixture was heated to 160°C and stirred to dehydrate. 23.3 parts of benzyl alcohol (0.6 equivalents relative to the hydroxyl groups of PH2) were added over 30 minutes, and the mixture was reacted at 160°C for 4 hours. 200 parts of MIBK were added to dissolve the product, neutralized with 1.2 parts of sodium bicarbonate, and washed with 60 parts of 80°C water. The lower layer of water was separated and removed. Then, under reduced pressure of 5 mmHg, the mixture was heated to 180°C to evaporate and remove the MIBK, yielding 116 parts of reddish-brown phenolic resin (P8). The hydroxyl group equivalent was 355, and the softening point was 106°C. Mass spectroscopy by ESI-MS (negative) revealed M- values ​​of 253, 343, 375, 385, 433, 465, 475, 507, 555, 597, 609, 687, 699, and 741. GPC showed Mw to be 1020 and Mn to be 580. A phenolic resin represented by formula (1), R 1 is a methyl group, R 3 The group had Ar represented by formula (1c) and Ar represented by formula (1d) of benzene, and the average value of n was 0.89.

[0082] Synthesis Example 4 (Comparison) In a reaction apparatus similar to that used in Synthesis Example 1, 100 parts of the aromatic hydroxy compound (pH3) obtained in Synthesis Example 3 were added to 1.6 parts of p-toluenesulfonic acid monohydrate (1 phr relative to the total amount of pH3 and benzyl alcohol) dissolved in 14.5 parts of water. The mixture was heated to 160°C and stirred to dehydrate it. 61.1 parts of benzyl alcohol (1.0 equivalent relative to the hydroxyl groups of pH3) were added over 30 minutes, and the mixture was reacted at 160°C for 4 hours. 240 parts of MIBK were added to dissolve the product, which was then neutralized with 1.4 parts of sodium bicarbonate. 80 parts of 80°C water were added for washing, and the lower layer of water was separated and removed. Subsequently, the MIBK was evaporated and removed under reduced pressure of 5 mmHg by heating to 180°C to obtain 143 parts of a reddish-brown phenolic resin (pH4). The hydroxyl group equivalent was 263, and the softening point was 75°C. The Mw and Mn values ​​in GPC were 830 and 700, respectively.

[0083] Example 9 A reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser was used to add 100 parts of the phenol resin (P1) obtained in Example 1 and epichlorohydrin (structural formula below). [ka] 158 parts of the solution and 24 parts of diethylene glycol dimethyl ether were added and the mixture was heated to 65°C. Under reduced pressure of 125 mmHg, 27.3 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and 280 parts of MIBK were added to dissolve the product. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with aqueous phosphoric acid solution, the resin solution was washed with water until the water wash was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove the MIBK by distillation, yielding 112 parts of reddish-brown epoxy resin (E1). The epoxy resin had an epoxy equivalent weight of 372, a total chlorine content of 610 ppm, and a softening point of 74°C. The IR of the obtained epoxy resin (E1) is shown in Figure 3, and the GPC is shown in Figure 4. The Mw was 810 and the Mn was 650 in the GPC.

[0084] Example 10 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P2) obtained in Example 2, 131 parts of epichlorohydrin, and 20 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 22.6 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and 270 parts of MIBK were added to dissolve the product. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 108 parts of a reddish-brown epoxy resin (E2). The epoxy equivalent was 429, the total chlorine content was 510 ppm, and the softening point was 76°C. The Mw and Mn values ​​measured by GPC were 790 and 610, respectively.

[0085] Example 11 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P3) obtained in Example 3, 124 parts of epichlorohydrin, and 19 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 21.5 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 270 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the water wash was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 108 parts of a reddish-brown epoxy resin (E3). The epoxy equivalent was 449, the total chlorine content was 580 ppm, and the softening point was 82°C. The Mw value in GPC was 1050 and the Mn value was 650.

[0086] Example 12 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P4) obtained in Example 4, 155 parts of epichlorohydrin, and 23 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 26.8 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 280 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 112 parts of a reddish-brown epoxy resin (E4). The epoxy equivalent was 376, the total chlorine content was 540 ppm, and the softening point was 87°C. The Mw value on GPC was 1410 and the Mn value was 650.

[0087] Example 13 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P5) obtained in Example 5, 147 parts of epichlorohydrin, and 22 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 25.4 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 280 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 111 parts of a reddish-brown epoxy resin (E5). The epoxy equivalent was 397, the total chlorine content was 510 ppm, and the softening point was 107°C. The Mw value on GPC was 2170 and the Mn value was 820.

[0088] Example 14 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P6) obtained in Example 6, 139 parts of epichlorohydrin, and 21 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 24.0 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 270 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 110 parts of a reddish-brown epoxy resin (E6). The epoxy equivalent was 419, the total chlorine content was 510 ppm, and the softening point was 75°C. The Mw value on GPC was 1110 and the Mn value was 550.

[0089] Example 15 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P7) obtained in Example 7, 133 parts of epichlorohydrin, and 20 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 23.1 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 270 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 109 parts of a reddish-brown epoxy resin (E7). The epoxy equivalent was 439, the total chlorine content was 440 ppm, and the softening point was 83°C. The Mw value on GPC was 1280 and the Mn value was 610.

[0090] Example 16 In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (P8) obtained in Example 8, 130 parts of epichlorohydrin, and 20 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 22.5 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 270 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 10⁹ parts of a reddish-brown epoxy resin (E8). The epoxy equivalent was 450, the total chlorine content was 600 ppm, and the softening point was 98°C. The Mw value on GPC was 1650 and the Mn value was 750.

[0091] Synthesis Example 5 (Comparison) In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (PH1) obtained in Synthesis Example 1, 237 parts of epichlorohydrin, and 36 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 41.0 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 300 parts of MIBK. Then, 90 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 121 parts of a reddish-brown epoxy resin (EH1). The epoxy equivalent was 261, the total chlorine content was 710 ppm, and the softening point was 55°C. The Mw value was 650 and the Mn value was 560 according to GPC.

[0092] Synthesis Example 6 (Comparison) In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (PH2) obtained in Synthesis Example 2, 166 parts of epichlorohydrin, and 25 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 28.8 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 280 parts of MIBK. Then, 80 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the water wash was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 113 parts of reddish-brown epoxy resin (EH2). The epoxy equivalent was 338, the total chlorine content was 630 ppm, and the resin was semi-solid at room temperature. The Mw value on GPC was 340 and the Mn value was 260.

[0093] Synthesis Example 7 (Comparison) In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (pH 3) obtained in Synthesis Example 3, 261 parts of epichlorohydrin, and 39 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 45.2 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 310 parts of MIBK. Then, 90 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 124 parts of a reddish-brown epoxy resin (EH3). The epoxy equivalent was 257, the total chlorine content was 1090 ppm, and the softening point was 74°C. The Mw value was 650 and the Mn value was 390 according to GPC.

[0094] Synthesis Example 8 (Comparison) In a reaction apparatus equipped with a stirrer, thermometer, nitrogen blowing tube, dropping funnel, and condenser, 100 parts of the phenol resin (PH4) obtained in Synthesis Example 4, 176 parts of epichlorohydrin, and 26 parts of diethylene glycol dimethyl ether were added and heated to 65°C. Under reduced pressure of 125 mmHg, 30.5 parts of 50% sodium hydroxide aqueous solution were added dropwise over 4 hours while maintaining a temperature of 63-67°C. During this time, the epichlorohydrin was azeotropically mixed with water, and the resulting water was sequentially removed from the system. After the reaction was complete, the epichlorohydrin was recovered under conditions of 5 mmHg and 180°C, and the product was dissolved by adding 280 parts of MIBK. Then, 90 parts of water were added to dissolve the by-product sodium chloride, and the mixture was allowed to stand to separate and remove the lower layer of saline solution. After neutralization with phosphoric acid aqueous solution, the resin solution was washed with water until the rinse solution was neutral, and then filtered. Under reduced pressure of 5 mmHg, the mixture was heated to 180°C to remove MIBK by distillation, yielding 114 parts of a reddish-brown epoxy resin (EH4). The epoxy equivalent was 339, the total chlorine content was 760 ppm, and the softening point was 62°C. The Mw value was 880 and the Mn value was 700 according to GPC.

[0095] Reference example 1 In a reactor equipped with a stirrer, thermometer, nitrogen blowing ring, dropping funnel, and condenser, 100 parts of pH3 from Synthesis Example 3, 81.5 parts of 1-naphthol (100 mol% relative to the hydroxyl groups of pH3), 10.9 parts of tetra-n-butylammonium bromide (TBAB) (3 mol% relative to the total hydroxyl groups of pH3 and 1-naphthol) were charged as aromatic hydroxy compounds, 114.7 parts of isophthalic acid chloride (100 mol% as acid halogen groups relative to the total hydroxyl groups of pH3 and 1-naphthol) were charged as aromatic carboxylic acid halides, and 730 parts of toluene (TL) were charged. The mixture was heated to 50°C and dissolved. While controlling the temperature in the system to below 60°C, 226.0 parts of 20% sodium hydroxide aqueous solution (20% NaOH) (100 mol% relative to the acid halogen groups of isophthalic acid chloride) were added dropwise over 3 hours, and stirring was continued at the same temperature for another 4 hours. The reaction mixture was allowed to stand and separated, and the water tank was removed. This procedure was repeated until the pH of the water tank reached 7. After that, water was removed by reflux dehydration, and after filtration, toluene was removed by heating to 180°C under reduced pressure of 5 mmHg to obtain 251 parts of activated ester resin (A1). The activated ester equivalent calculated from the amount of raw materials charged was 227, the phenolic hydroxyl group equivalent was 14200, the total chlorine content was 140 ppm, the softening point was 124°C, the Mw was 1140 and the Mn was 620 according to GPC.

[0096] Example 17 An epoxy resin composition varnish was obtained by mixing 100 parts epoxy resin (E1) as the epoxy resin, 28 parts phenolic resin (PH5) as the curing agent, and 0.40 parts C1 as the curing accelerator, and dissolving them in a mixed solvent prepared with MEK, propylene glycol monomethyl ether, and N,N-dimethylformamide. The obtained epoxy resin composition varnish was impregnated into glass cloth (manufactured by Nitto Boseki Co., Ltd., WEA 7628 XS13, 0.18 mm thick). The impregnated glass cloth was dried in a hot air circulating oven at 150°C for 9 minutes to obtain a prepreg. Eight of the obtained prepregs were stacked with copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC-III, 35 μm thick) on the top and bottom, and vacuum pressing was performed at 2 MPa under the temperature conditions of 130°C for 15 minutes + 190°C for 80 minutes to obtain a 1.6 mm thick laminate. The results of the interlayer adhesion strength of the laminate are shown in Table 1. The obtained prepreg was loosened and sieved to obtain a 100-mesh pass prepreg powder. The obtained prepreg powder was placed in a fluororesin mold and subjected to a 2 MPa vacuum press at a temperature of 130°C for 15 minutes + 190°C for 80 minutes to obtain a 70 mm square × 0.5 mm thick test specimen. The relative permittivity and dielectric loss tangent of the test specimen are shown in Table 1.

[0097] Examples 18-24, 25-32 and Comparative Examples 1-4 The mixture was prepared using the proportions (parts) shown in Tables 1 and 2, and the same procedure as in Example 17 was followed to obtain laminates and test specimens. The same tests as in Example 17 were performed, and the results are shown in Tables 1 and 2.

[0098] [Table 1]

[0099] [Table 2]

[0100] Example 33 E1 was mixed with 100 parts as epoxy resin, 59 parts as curing agent, and 0.5 parts as curing accelerator. This mixture was dissolved in toluene to obtain an epoxy resin composition varnish with a non-volatile content of 50%. The obtained epoxy resin composition varnish was impregnated into glass cloth (manufactured by Nitto Boseki Co., Ltd., WEA 7628 XS13, 0.18 mm thick). The impregnated glass cloth was dried in a hot air circulating oven at 130°C for 5 minutes to obtain a prepreg. Eight of the obtained prepregs were stacked with copper foil (manufactured by Mitsui Mining & Smelting Co., Ltd., 3EC-III, 35 μm thick) on the top and bottom, and a 1.6 mm thick laminate was obtained by vacuum pressing at 2 MPa under the temperature conditions of 130°C for 15 minutes + 210°C for 80 minutes. The results of the interlayer adhesion strength of the laminate are shown in Table 3. The obtained prepreg was loosened and sieved to produce a 100-mesh pass prepreg powder. The obtained prepreg powder was placed in a fluororesin mold and subjected to a vacuum press at 2 MPa under the temperature conditions of 130°C for 15 minutes + 210°C for 80 minutes to obtain a 70 mm square × 0.5 mm thick test specimen. The relative permittivity and dielectric loss tangent of the test specimen are shown in Table 3.

[0101] Examples 34-40 and Comparative Examples 5-8 The mixture was prepared using the proportions (parts) shown in Table 3, and the same procedure as in Example 33 was followed to obtain laminates and test specimens. The same tests as in Example 33 were performed, and the results are shown in Table 3.

[0102] [Table 3]

[0103] As is clear from these results, the polyvalent hydroxy resins and epoxy resins obtained in the examples, and the resin compositions containing them, can provide cured resin products that exhibit very good low dielectric properties while maintaining an adhesive strength of 0.8 kN / m or higher, which is practically acceptable.

Claims

1. A phenolic resin characterized by being represented by the following general formula (1). 【Chemistry 1】 (In the formula, R １ Each independently represents a hydrocarbon group having 1 to 8 carbon atoms, R ３ Each of these independently represents a hydrogen atom, a dicyclopentenyl group represented by formula (1a) or formula (1b) below, or a group represented by formula (1c) or formula (1d), R ３ At least one of these is a group represented by formula (1c) or formula (1d). Ar represents a substituted or unsubstituted aromatic hydrocarbon group. * represents one R from formula (1). ３ These are the residues excluding the specified residue. n indicates the number of repetitions, and its average value is between 0 and 5.

2. R １ The phenol resin according to claim 1, wherein is a methyl group or a phenyl group.

3. A method for producing a phenol resin according to claim 1, characterized by reacting a polyvalent hydroxy resin (a) represented by the following general formula (2) with an aralkyl compound (b) represented by the following general formula (3a) and / or general formula (3b). 【Chemistry 2】 【Transformation 3】 (In equation (2), R1 and n are equivalent to those in equation (1). ２ Each independently represents a hydrogen atom, a dicyclopentenyl group represented by formula (2a), or formula (2b). In formulas (3a) and (3b), Ar is equivalent to that in formulas (1a) and (1b). X represents a leaving group.

4. A method for producing a polyvalent hydroxy resin according to claim 3, characterized in that, in the presence of an acid catalyst, 0.05 to 2.0 moles of an aralkyl compound (b) are reacted with 1 mole of phenolic hydroxyl groups of a polyvalent hydroxy resin (a) at a reaction temperature of 50 to 200°C.

5. An epoxy resin represented by the following general formula (4). 【Chemistry 4】 (In the formula, R １ each independently represents a hydrocarbon group having 1 to 8 carbon atoms, and R ３ each independently represents a hydrogen atom, a dicyclopentenyl group represented by formula (4a) or formula (4b), or a group represented by formula (4c) or formula (4d), and R ３ at least one of is a group represented by formula (4c) or formula (4d). Ar represents a substituted or unsubstituted aromatic hydrocarbon group. * represents a residue obtained by removing one R from formula (4) ２ . m represents the number of repeating units, and the average value thereof is a number of 0 to 5.)

6. A method for producing an epoxy resin according to claim 5, characterized in that 1 to 20 moles of epihalohydrin are reacted with 1 mole of phenolic hydroxyl groups of a polyvalent hydroxyl resin represented by general formula (1) as described in claim 1, in the presence of an alkali metal hydroxide.

7. An epoxy resin composition comprising an epoxy resin and a curing agent, characterized in that it requires the polyvalent hydroxy resin described in claim 1 and / or the epoxy resin described in claim 5.

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

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

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

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

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

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