Ester compound and ester compound composition for resin raw material

Abstract

The present invention addresses the problem of providing a curing agent for forming a cured product having good handling properties and excellent heat resistance and dielectric properties. As a solution, an ester compound represented by general formula (3) is provided, in the [chemical formula 1] # imgabs 0 # formula, R2 each independently represents a single bond or a divalent hydrocarbon group having 1-10 carbon atoms, R3 each independently represents a hydrogen atom or an alkyl group having 1-6 carbon atoms, Y represents a divalent group represented by general formula (3a) or general formula (3b), in the [chemical formula 2] # imgabs 1 # general formula (3a) and (3b), R1 each independently represents an alkyl group having 1-6 carbon atoms or an aryl group having 6-12 carbon atoms, R2 each independently represents a single bond or a divalent hydrocarbon group having 1-10 carbon atoms, R3 each independently represents a hydrogen atom or an alkyl group having 1-6 carbon atoms, and Y represents a divalent group represented by general formula (3a) or general formula (3b). (In general formula (3a), each * represents a bonding position, in general formula (3a), each m independently represents an integer of 1-4, in general formula (3b), each n independently represents 0 or an integer of 1-4, and Z represents a cycloalkylidene group having 7-20 carbon atoms.

Description

Technical Field

[0001] The present invention relates to an ester compound and an ester compound composition for resin raw materials. Specifically, it relates to an ester compound having furan rings at both ends of a bonding group and an ester compound composition for resin raw materials containing the ester compound. Background Art

[0002] Epoxy resins are used in various fields such as adhesives, coatings, composite materials, civil engineering and construction materials, and insulating materials for electrical and electronic components because of their excellent heat resistance, adhesiveness, water resistance, mechanical strength, and electrical properties. Especially in the electrical and electronic field, they are widely used in insulation potting, laminates, sealing materials, etc.

[0003] As important properties required for epoxy resins used as materials for electrical and electronic components, high heat resistance, low CTE, low dielectric constant, low dielectric loss tangent, low moisture absorption, etc. can be cited. In addition, in the field of highly integrated semiconductor materials, in recent years, with the continuous development of high multi-layerization, thinning of insulating layers, and complication of structures, in addition to the above-listed characteristics, it is also required to balance various characteristics such as solvent solubility. Recently, it has been reported that by esterifying the secondary hydroxyl groups generated by the reaction of epoxy groups with a curing agent to suppress polarization, a technique for improving low moisture absorption or dielectric properties has been developed.

[0004] Patent Document 1 discloses a thermosetting composition that uses a thermoplastic resin obtained by esterifying the secondary hydroxyl groups of an epoxy resin in a subsequent process and formulates a thermosetting resin therein, so that while maintaining low moisture absorption and dielectric properties, the adhesion to a conductor layer can be improved, but its heat resistance is not sufficient.

[0005] Patent Document Patent Document 1: International Publication No. 2005 / 095517 Summary of the Invention In view of the above prior art, an object of the present invention is to provide a curing agent that has good processability such as solvent solubility and is used to form a cured product having excellent heat resistance and dielectric properties.

[0006] The inventors of the present invention conducted in-depth research to solve the above problems and found that an ester compound formed from a bisphenol compound having a specific structure and a carboxylic acid containing a furan ring can be dissolved in solvents such as methyl ethyl ketone and has good processability. In addition, when used as a curing agent, it can be chain-linked by reacting with an epoxy resin and cured by chain-linking. Further, the polarization of the cured product obtained by esterifying the secondary hydroxyl groups is suppressed, and thus it has excellent dielectric properties and heat resistance, thereby completing the present invention.

[0007] The present invention is as follows.

[0008] 1. An ester compound, characterized in that it is represented by the general formula (3), [Chemical formula 1]

[0009] In the formula, R 2 each independently represents a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms, and R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Y represents a divalent group represented by the general formula (3a) or the general formula (3b). [Chemical formula 2]

[0010] In the general formulas (3a) and (3b), R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, * each represents a bonding position, in the general formula (3a), m each independently represents an integer of 1 to 4, and in the general formula (3b), n each independently represents 0 or an integer of 1 to 4, and Z represents a cycloalkanediyl group having 7 to 20 carbon atoms.

[0011] 2. The ester compound according to 1., characterized in that all of the R in the ester compound represented by the general formula (3) 2 are single bonds.

[0012] 3. The ester compound according to 2., characterized in that, further, all of the R in the ester compound represented by the general formula (3) 3 are hydrogen atoms.

[0013] 4. The ester compound according to 3., characterized in that the ester compound represented by the general formula (3) is compound (p-139), (p-142), (p-145), (p-148), (p-151), (p-154) or (p-172), [Chemical formula 3] .

[0014] 5. A crystal of an ester compound of compound (p-148), characterized in that the compound (p-148) is the compound described in 4.

[0015] 6. The crystal of the ester compound of compound (p-148) according to 5., characterized in that the maximum endothermic peak temperature obtained by differential scanning calorimetry is in the range of 234 to 240 °C.

[0016] 7. A crystal of an ester compound of compound (p-151), characterized in that the compound (p-151) is the compound described in 4.

[0017] 8. Crystallization of the ester compound of the compound (p-151) according to 7., characterized in that the maximum endothermic peak temperature obtained by differential scanning calorimetry is in the range of 180 to 188 °C.

[0018] 9. An ester compound composition for resin raw materials, characterized by containing the ester compound represented by the general formula (3) according to 1. and the ester compound represented by the general formula (2), [Chemical formula 4]

[0019] In the formula, R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R 6 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a divalent group represented by the general formula (1a), (1b), or (1c), and n each independently represents 0 or an integer of 1 to 4, [Chemical formula 5]

[0020] In the general formulas (1a), (1b), and (1c), R 4 and R 5 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, R 4 and R 5 may be bonded to each other to form a cycloalkanediyl group having 5 to 20 carbon atoms as a whole, Ar 1 and Ar 2 represent an aryl group having 6 to 12 carbon atoms, and * each represents a bonding position.

[0021] 10. The ester compound composition for resin raw materials according to 9., characterized in that 0.1 to 400 parts by weight of the ester compound represented by the general formula (2) is contained relative to 100 parts by weight of the ester compound represented by the general formula (3).

[0022] 11. An epoxy resin, characterized in that it is obtained by reacting the ester compound represented by the general formula (3) according to 1. with any one of an aromatic diglycidyl ether compound, a mixture containing an aromatic dihydroxy compound and epihalohydrin, and a phenoxy resin having an epoxy group obtained by polymerizing an aromatic dihydroxy compound and epihalohydrin.

[0023] The ester compound represented by the general formula (3), which is obtained by ester-bonding a specific bisphenol of the present invention with a carboxylic acid having a furan ring, is soluble in solvents such as methyl ethyl ketone, and thus has good processability. In addition, by using this ester compound as a curing agent, it can react with an epoxy resin, enabling chain-linking and curing. Further, by esterifying secondary hydroxyl groups, polarization can be suppressed, and a cured product having excellent dielectric properties and heat resistance can be provided.

[0024] Therefore, the ester compound represented by the general formula (3) of the present invention can be applied to various fields such as adhesives, composite materials, coatings, civil engineering building materials, and insulating materials for electrical and electronic components, and a cured product that is particularly useful as an insulating potting material, a laminated material, a sealing material, etc. in the electrical and electronic fields can be obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a graph showing the differential scanning calorimetry (DSC) of the ester compound (1-1) (compound (p-151)) obtained in Example 1.

[0026] Figure 2 It is a graph showing the differential scanning calorimetry (DSC) of the ester compound (1-2) (compound (p-28)) obtained in Example 2.

[0027] Figure 3 It is a graph showing the differential scanning calorimetry (DSC) of the ester compound (1-3) (compound (p-148)) obtained in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0028] <Curing Composition> The curing composition of the present invention contains an ester compound represented by the general formula (1), a thermosetting compound, and / or a compound having a radically polymerizable substituent.

[0029] [Chemical Formula 6]

[0030] (In the formula, R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R 2 each independently represents a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms, R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group, or a divalent group represented by the general formula (1a), (1b), or (1c), and n each independently represents 0 or an integer of 1 to 4.) [Chemical Formula 7]

[0031] (In general formulas (1a), (1b) and (1c), R 4 and R 5 each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, R 4 and R 5 may bond to each other to form a cycloalkanediyl group having 5 to 20 carbon atoms as a whole, Ar 1 and Ar 2 represent an aryl group having 6 to 12 carbon atoms, and * each represents a bonding position.) By containing the ester compound represented by general formula (1), a cured product obtained by curing the curable composition can have excellent heat resistance.

[0032] Among them, particularly for the secondary hydroxyl group generated by the reaction of an epoxy resin and a curing agent of a thermosetting compound, the ester compound represented by general formula (1) reacts with the epoxy resin as a curing agent and esterifies the secondary hydroxyl group. As a result, the polarization of the obtained cured product is suppressed, and thus excellent dielectric properties are achieved. Therefore, the curable composition of the present invention is useful and preferred in the form containing an epoxy resin because the obtained cured product has this characteristic. In addition, it can be seen from this that when the ester compound represented by general formula (1) is used as a curing agent for an epoxy resin, the obtained cured product has the above characteristics and is therefore preferred.

[0033] Since the ester compound represented by general formula (1) has a furan ring, it also undergoes a curing reaction with a compound having a radically polymerizable substituent, and thus a cured product can be obtained.

[0034] The ester compound represented by general formula (1) has excellent solubility in solvents such as methyl ethyl ketone, cyclohexanone, N-methylpyrrolidone, toluene, propylene glycol monomethyl ether acetate, and ethyl acetate, and particularly has excellent solubility in methyl ethyl ketone, which is one of the solvents widely used in the manufacture of electronic components such as semiconductors. Therefore, the processability is excellent.

[0035] (The ester compound represented by general formula (1)) R in general formula (1) 1 is preferably each independently an alkyl group having 1 to 4 carbon atoms or a phenyl group, more preferably each independently a methyl group or a phenyl group, and particularly preferably a methyl group.

[0036] R in general formula (1) 2Each independently represents a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms. When it is a divalent hydrocarbon group, specifically, for example, it may include: methylene, ethylene, propane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, a linear or branched alkylene group having 1 to 10 carbon atoms such as cyclohexane-1,3-diyl or cyclohexane-1,4-diyl, or an alkylene group containing a cycloalkane; an alkylidene group having 1 to 10 carbon atoms such as ethylidene, propylidene, isopropylidene, butylidene, cyclopentylidene, cyclohexylidene; a divalent group having 1 to 10 carbon atoms containing a benzene ring such as a phenylene group or a group represented by the following formula.

[0037] [Chemical Formula 8]

[0038] (In the formula, * represents the bonding position.) Among these, R 2 Preferably, each independently represents a single bond or a linear or branched alkylene group having 1 to 10 carbon atoms, an alkylene group containing a cycloalkane, or an alkylidene group having 1 to 10 carbon atoms. More preferably, each independently represents a single bond or a linear or branched alkylene group having 1 to 10 carbon atoms or an alkylene group containing a cycloalkane. Further preferably, each independently represents a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms or an alkylene group containing a cycloalkane. Particularly preferably, all are single bonds. R 2 The ester compound represented by the general formula (1) in which all are single bonds is obtained from a biomass-derived raw material, and thus it is also preferred in terms of a curable composition with an improved biomass yield.

[0039] R in the general formula (1) 3 Preferably, each independently represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. More preferably, each independently represents a hydrogen atom or a methyl group. Particularly preferably, all are hydrogen atoms.

[0040] X in the general formula (1) is preferably a single bond, a sulfonyl group, a carbonyl group, or a divalent group represented by the general formula (1a), (1b), or (1c). More preferably, it is a single bond or a divalent group represented by the general formula (1a) or the general formula (1b). Further preferably, it is a single bond or a divalent group represented by the general formula (1a). Among the single bond or the divalent group represented by the general formula (1a), particularly preferably, R 4 and R 5 are bonded to each other and form, as a whole, a divalent group of an alkylidene group having 5 to 20 carbon atoms.

[0041] When X in the general formula (1) is the general formula (1a), R 4 and R 5More preferably, they are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a haloalkyl group having 1 to 6 carbon atoms, or an aryl group having 6 to 12 carbon atoms. Even more preferably, they are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a trifluoromethyl group, or an aryl group having 6 to 8 carbon atoms. Particularly preferably, they are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a phenyl group.

[0042] In addition, R 4 and R 5 may be bonded to each other to form a cycloalkanediyl group having 5 to 20 carbon atoms as a whole. R 4 and R 5 are more preferably in this form. The cycloalkanediyl group having 5 to 20 carbon atoms may also contain an alkyl group as a side chain. The cycloalkanediyl group is preferably having 5 to 15 carbon atoms, more preferably having 6 to 12 carbon atoms, and particularly preferably having 6 to 9 carbon atoms. As the cycloalkanediyl group, specifically, for example, cyclopentanediyl (5 carbon atoms), cyclohexanediyl (6 carbon atoms), 3-methylcyclohexanediyl (7 carbon atoms), 4-methylcyclohexanediyl (7 carbon atoms), 3,3,5-trimethylcyclohexanediyl (9 carbon atoms), cycloheptanediyl (7 carbon atoms), cyclododecanediyl (12 carbon atoms), etc. may be mentioned. Preferred are cyclohexanediyl (6 carbon atoms), 3-methylcyclohexanediyl (7 carbon atoms), 4-methylcyclohexanediyl (7 carbon atoms), 3,3,5-trimethylcyclohexanediyl (9 carbon atoms), cyclododecanediyl (12 carbon atoms), etc., and more preferred are cyclohexanediyl (6 carbon atoms), 3,3,5-trimethylcyclohexanediyl (9 carbon atoms), cyclododecanediyl (12 carbon atoms).

[0043] When X in the general formula (1) is the general formula (1b), Ar 1 and Ar 2 are preferably each independently a benzene ring or a naphthalene ring. More preferably, Ar 1 and Ar 2 are both benzene rings. For example, when Ar 1 and Ar 2 are both benzene rings, the group represented by the general formula (1b) is a fluorenylidene group.

[0044] When X in the general formula (1) is the general formula (1c), it is preferably a divalent group of 1,3-bis(isopropyl-2-yl)benzene or 1,4-bis(isopropyl-2-yl)benzene.

[0045] The bonding positions of X in the general formula (1) to the two benzene rings relative to the oxygen atom bonded to the benzene ring are preferably each independently an ortho position or a para position, and more preferably a para position.

[0046] In the general formula (1), n is preferably each independently 0, 2, or 3. In addition, when n is an integer of 1 to 4, R 1Relative to the oxygen atom bonded to the benzene ring, it is preferably bonded to the ortho position preferentially.

[0047] As specific examples of the ester compound represented by the general formula (1), compounds (p-1) to (p-171) having the following chemical structures are shown.

[0048] [Chemical formula 9]

[0049] [Chemical formula 10]

[0050] [Chemical formula 11]

[0051] [Chemical formula 12]

[0052] [Chemical formula 13]

[0053] [Chemical formula 14]

[0054] [Chemical formula 15]

[0055] [Chemical formula 16]

[0056] [Chemical formula 17]

[0057] [Chemical formula 18]

[0058] [Chemical formula 19]

[0059] [Chemical formula 20]

[0060] [Chemical formula 21]

[0061] [Chemical formula 22]

[0062] [Chemical formula 23]

[0063] <Manufacturing method of the ester compound represented by the general formula (1)> Regarding the ester compound represented by the general formula (1), there are no particular limitations on the starting materials and manufacturing methods in its production. For example, as exemplified by the following reaction formula, the following manufacturing methods can be cited: In the esterification step of synthesizing the ester compound represented by the general formula (2) by reacting the bisphenol compound represented by the general formula (5) with the acid anhydride represented by the general formula (6), after synthesizing the ester compound represented by the general formula (2), an ester exchange reaction step of reacting the ester compound represented by the general formula (2) with the furan carboxylic acid-containing compound represented by the general formula (8) to obtain the ester compound represented by the general formula (1) is used to obtain the manufacturing method of the ester compound represented by the general formula (1).

[0064] [Chemical formula 24]

[0065] (R in the general formula (5) 1 , X and n, and R in the general formula (8) 2 and R 3 , have the same definitions as those in the general formula (1). R in the general formula (6) and the general formula (7) 6 has the same definition as that of the following general formula (2).) (Esterification step) The reaction method of the esterification step in the above manufacturing method can apply the methods of esterification reactions known in the past.

[0066] As the bisphenol compound represented by the general formula (5), specifically, for example, bisphenol F (bis(2-hydroxyphenyl)methane, 2-hydroxyphenyl-4-hydroxyphenylmethane, bis(4-hydroxyphenyl)methane), bisphenol E (1,1-bis(4-hydroxyphenyl)ethane), bisphenol A (2,2-bis(4-hydroxyphenyl)propane), bisphenol C (2,2-bis(4-hydroxy-3-methylphenyl)propane), 2,2-bis(4-hydroxyphenyl)-4-methylpentane, 4,4'-dihydroxybiphenyl, 4,4'-dihydroxy-3,3'-dimethylbiphenyl, 4,4'-dihydroxy-3,3',5,5'-tetramethylbiphenyl, 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl, bis(4-hydroxyphenyl)ether, 4,4'-dihydroxybenzophenone, bis(4-hydroxyphenyl)sulfone, bis(4-hydroxyphenyl)sulfide, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,1-bis(4-hydroxyphenyl)-1-naphthylethane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, bisphenol Z (1,1-bis(4-hydroxyphenyl)cyclohexane), bisphenol TMC (1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane), 1,1-bis(4-hydroxyphenyl)-3-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-4-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)cyclododecane, 9,9-bis(4-hydroxy-3-methylphenyl)fluorene).

[0067] As the acid anhydride represented by the general formula (6), specifically, for example, acetic anhydride and benzoic anhydride can be cited. Regarding R in the general formula (6) 6 , its definition and preferred form are the same as those of the general formula (2) described later.

[0068] In the above manufacturing method, as the usage amount of the acid anhydride represented by the general formula (6), relative to 1 mole of the bisphenol compound represented by the general formula (5), it is preferably in the range of 2.0 to 10.0 moles, more preferably in the range of 2.0 to 8.0 moles, and further preferably in the range of 2.0 to 4.0 moles.

[0069] The reaction temperature is generally in the range of 50 to 150 °C, preferably in the range of 80 to 140 °C. The reaction pressure can be either under normal pressure or reduced pressure.

[0070] Through the above esterification process, the ester compound represented by the general formula (2) can be manufactured.

[0071] (Ester compound represented by the general formula (2)) [Chemical formula 25]

[0072] (In the formula, R 1 , X and n have the same definitions as those in the general formula (1), R6 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms.) R in the general formula (2) 1 、X and n have the same definitions as in the general formula (1), and preferably have the same forms.

[0073] R in the general formula (2) 6 is preferably each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms, more preferably each independently an alkyl group or a phenyl group having 1 to 6 carbon atoms, still more preferably each independently a methyl group or a phenyl group, and particularly preferably a methyl group.

[0074] As the monovalent hydrocarbon group having 1 to 20 carbon atoms of R in the general formula (2) 6 specific examples include: chain monovalent hydrocarbon groups such as methyl, ethyl, propyl, isobutyl, butyl, hexyl, octyl, decyl; cyclic monovalent hydrocarbon groups such as cyclohexyl; monovalent aromatic hydrocarbon groups such as phenyl and naphthyl.

[0075] The ester compound represented by the general formula (2) obtained from the esterification step can be directly used in the state of being contained in the reaction solution of the esterification reaction as a raw material for the subsequent transesterification reaction step, or can be refined by distilling off the carboxylic acid represented by the general formula (7) generated in the esterification reaction and then used, or can be refined by performing a crystallization operation by mixing a solvent into the esterification reaction solution and then used.

[0076] (Transesterification reaction step) The reaction method of the transesterification reaction step in the above manufacturing method can be an application of the conventionally known transesterification reaction method.

[0077] R in the general formula (8) 2 and R 3 have the same definitions as in the general formula (1), and preferably have the same forms or specific examples.

[0078] As the furan carboxylic acid represented by the general formula (8), specific examples include: 2-furan carboxylic acid, 3-furan carboxylic acid, 2-methyl-3-furan carboxylic acid, 3-methyl-2-furan carboxylic acid.

[0079] As the usage amount of the furan carboxylic acid represented by the general formula (8), relative to 1 mole of the ester compound represented by the general formula (2), it is preferably in the range of 2.0 to 10.0 moles, more preferably in the range of 2.0 to 8.0 moles, still more preferably in the range of 2.0 to 4.0 moles.

[0080] As a catalyst in the reaction of the ester compound represented by the general formula (2) with the furan carboxylic acid represented by the general formula (8), a base is preferably used. Specific examples of these bases include organic bases such as amine bases, inorganic alkali metal compounds such as hydroxides, carbonates, and bicarbonate compounds of alkali metals, organic alkali metal compounds such as alkoxides, phenoxides, and salts with organic carboxylic acids of alkali metals, etc. In addition, mixtures thereof, etc. may be mentioned, but are not limited thereto.

[0081] The reaction is usually carried out in the presence of a solvent. For reasons such as improving the operability during industrial production or the reaction rate, a reaction solvent is preferably used during the reaction. The solvent to be used is not particularly limited as long as it does not distill out of the reaction vessel at the following reaction temperature and is inactive for the transesterification reaction. Specifically, for example, there may be mentioned: aromatic hydrocarbon ether solvents such as alkyl aryl ethers like phenetole and butyl phenyl ether or diaryl ethers like diphenyl ether and di-p-tolyl ether; aromatic hydrocarbons such as biphenyl and terphenyl; alkyl-substituted naphthalenes such as diisopropylnaphthalene; aliphatic hydrocarbons such as decalin and kerosene; polyalkylene glycol ethers such as tetraethylene glycol dimethyl ether and diethylene glycol dibutyl ether; organic solvents such as Therm-S series (manufactured by Nippon Steel Chemical Co., Ltd.), KSK-OIL series (manufactured by Soken Chemical & Engineering Co., Ltd.) or NeoSK-OIL series (manufactured by Soken Chemical & Engineering Co., Ltd.). In addition, the amount of the solvent used is not particularly limited as long as it does not hinder the reaction, and is usually used in a range of 0.5 to 20 weight times, preferably 1 to 10 weight times, relative to the ester compound represented by the general formula (2).

[0082] The reaction temperature is usually carried out in the range of 40 to 260 °C, preferably in the range of 80 to 255 °C, more preferably in the range of 120 to 250 °C, further preferably in the range of 160 to 245 °C, and particularly preferably in the range of 180 to 240 °C.

[0083] The reaction pressure can be carried out under normal pressure conditions. In addition, it can also be carried out under pressure or reduced pressure.

[0084] As another method, it may also include the step of discharging the carboxylic acid represented by the general formula (7) generated in the reaction out of the system. The step of removing the generated carboxylic acid represented by the general formula (7) from the reaction solution is not particularly limited, and can be carried out by distilling the generated carboxylic acid represented by the general formula (7) together with the solvents in the reaction solution. The generated carboxylic acid represented by the general formula (7) can be discharged out of the reaction system, for example, using an isobaric dropping funnel equipped with a stopcock, a Dimroth condenser, a Dean-Stark apparatus, etc.

[0085] Regarding the obtained reaction-terminated mixture, after the reaction is completed, the ester compound represented by the general formula (1) can be obtained from the mixture by known methods. For example, after the reaction, it is conceivable to cool and crystallize the reaction mixture and obtain the target product in the form of powder or granules by filtration. In addition, it is also conceivable to add the reaction mixture to a poor solvent to obtain the precipitated target product, or add a solvent to the reaction mixture for crystallization and then obtain the target product in the form of powder or granules by filtration.

[0086] The ester compound represented by the general formula (1) extracted by the above method can be made into a high-purity product by usual purification methods such as washing or recrystallization with a solvent or water. As the solvent that can be used for crystallization and slurrying, there is no particular limitation as long as it is a solvent that is inactive with respect to the ester compound represented by the general formula (1). Specifically, examples include alcohol solvents such as methanol, ethanol, isopropanol, and 1-butanol; or carbonyl solvents such as acetic anhydride, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; ether solvents such as tetrahydrofuran, methyl isobutyl ether, methyl isopropyl ether, and diphenyl ether; aromatic non-polar solvents such as toluene, xylene, and ethylbenzene; γ-butyrolactone, γ-valerolactone, acrylonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like. Among them, 1-butanol, isopropanol, diphenyl ether, etc. are preferred.

[0087] The conditions for crystallization vary depending on the solvent used and cannot be generalized. For example, when using 1-butanol, the amount of the solvent used is in the range of 1 to 50 parts by weight, more preferably in the range of 2 to 30 parts by weight, and particularly preferably in the range of 2 to 10 parts by weight, relative to 1 part by weight of the total amount of the composition containing the ester compound represented by the general formula (1) to be refined and other impurities. The temperature during dissolution is in the range of 50 to 250 °C, more preferably in the range of 70 to 230 °C, further preferably in the range of 80 to 200 °C, and particularly preferably in the range of 90 to 180 °C. The cooling temperature is in the range of 0 to 50 °C, more preferably in the range of 10 to 40 °C, and further preferably in the range of 15 to 35 °C. The pressure during crystallization can be carried out under normal pressure conditions. In addition, it can also be carried out under pressure.

[0088] When using other solvents, various conditions can be appropriately changed in consideration of the boiling point of the solvent, or the solubility of the ester compound represented by the general formula (1) to be refined, other impurities, and the composition containing these.

[0089] Since the refined product obtained by these refining processes sometimes contains the solvent used, it is preferable to remove the solvent and carry out drying. The method for removing the solvent is not particularly limited. For example, a method of heating under normal pressure or reduced pressure to distill off the solvent can be cited.

[0090] <The ester compound represented by the general formula (3)> Among the ester compounds represented by the general formula (1) used in the curable composition of the present invention, the ester compound represented by the general formula (3) has more excellent heat resistance when a cured product is obtained using the curable composition of the present invention, and is therefore preferred.

[0091] Among them, particularly with respect to the secondary hydroxyl groups generated by the reaction of an epoxy resin, which is a thermosetting compound, with a curing agent, the ester compound represented by the general formula (3), like the ester compound represented by the general formula (1), reacts with the epoxy resin as a curing agent and esterifies the secondary hydroxyl groups, whereby the polarization of the resulting cured product is suppressed, and thus excellent dielectric properties are achieved. In addition, it can be seen from this that when the ester compound represented by the general formula (3) is used as a curing agent for an epoxy resin, like the ester compound represented by the general formula (1), the resulting cured product has the above characteristics, and is therefore preferred.

[0092] Since the ester compound represented by the general formula (3) has a furan ring like the ester compound represented by the general formula (1), it also undergoes a curing reaction with a compound having a radically polymerizable substituent, and thus a cured product can be obtained.

[0093] The ester compound represented by the general formula (3) has excellent solubility in solvents such as methyl ethyl ketone, cyclohexanone, N-methylpyrrolidone, toluene, propylene glycol monomethyl ether acetate, and ethyl acetate, and particularly has excellent solubility in methyl ethyl ketone, which is widely used as one of the solvents for manufacturing electronic components such as semiconductors, and thus has excellent processability.

[0094] [Chemical formula 26]

[0095] (In the formula, R 2 each independently represents a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms, and R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Y represents a divalent group represented by the general formula (3a) or the general formula (3b).) [Chemical formula 27]

[0096] (In the general formulas (3a) and (3b), R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and * each represents a bonding position. In the general formula (3a), m each independently represents an integer of 1 to 4. In the general formula (3b), n each independently represents 0 or an integer of 1 to 4, and Z represents a cycloalkanediyl group having 7 to 20 carbon atoms.) R in the general formula (3) 2 and R 3 Specific examples or preferred forms of are the same as those of R in the general formula (1)2 and R 3 are the same. That is, R in the general formula (3) 2 each independently represents a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms. In the case of a divalent hydrocarbon group, specifically, for example, it may include: methylene, ethylene, propane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl and other linear or branched alkylene groups having 1 to 10 carbon atoms or alkylene groups containing cycloalkanes; ethylidene, propylidene, isopropylidene, butylidene, cyclopentylidene, cyclohexylidene and other alkylidene groups having 1 to 10 carbon atoms; a phenylene group or a divalent group represented by the following formula and other divalent groups having 1 to 10 carbon atoms containing a benzene ring.

[0097] [Chemical formula 28]

[0098] (In the formula, * represents the bonding position.) Among these, R 2 is preferably each independently a single bond or a linear or branched alkylene group having 1 to 10 carbon atoms, an alkylene group containing a cycloalkane, or an alkylidene group having 1 to 10 carbon atoms, more preferably each independently a single bond or a linear or branched alkylene group having 1 to 10 carbon atoms or an alkylene group containing a cycloalkane, still more preferably each independently a single bond or a linear or branched alkylene group having 1 to 6 carbon atoms or an alkylene group containing a cycloalkane, and particularly preferably all are single bonds. R 2 The ester compound represented by the general formula (3) in which all are single bonds is obtained from a biomass-derived raw material, and thus it is also preferred in terms of a curable composition with an improved biomass yield.

[0099] R in the general formula (3) 3 is preferably each independently a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, more preferably each independently a hydrogen atom or a methyl group, and particularly preferably all are hydrogen atoms.

[0100] When Y in the general formula (3) is of the general formula (3a), the preferred form of R 1 is the same as that of R in the general formula (1). That is, when Y in the general formula (3) is of the general formula (3a), R 1 is preferably each independently an alkyl group having 1 to 4 carbon atoms or a phenyl group, more preferably each independently a methyl group or a phenyl group, and particularly preferably a methyl group. 1 When Y in the general formula (3) is of the general formula (3a), m each independently represents an integer of 1 to 4, preferably each independently 1 to 3, more preferably each independently 2 or 3, and particularly preferably all are 3. In addition, R

[0101] 1 ​Relative to the oxygen atom bonded to the benzene ring, it is preferably bonded preferentially to the ortho position.

[0102] As a more preferred form when Y in the general formula (3) is the general formula (3a), it is preferably a structure selected from the general formulas (3a-1) to (3a-4), more preferably a structure selected from the general formulas (3a-2) to (3a-4), further preferably the general formula (3a-3) or (3a-4), and particularly preferably the general formula (3a-4).

[0103] [Chemical formula 29]

[0104] (In the formula, R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, and * represents the bonding position.) When Y in the general formula (3) is the general formula (3b), the preferred form of R 1 is the same as the preferred form of R 1 in the general formula (1). That is, when Y in the general formula (3) is the general formula (3b), R 1 is preferably each independently an alkyl group having 1 to 4 carbon atoms or a phenyl group, more preferably each independently a methyl group or a phenyl group, and particularly preferably a methyl group.

[0105] When Y in the general formula (3) is the general formula (3b), n is preferably 0, 1, or 2, more preferably 0 or 1, and particularly preferably both are 0. In addition, the substitution position of R 1 is preferably the ortho position relative to the oxygen atom.

[0106] Z in the general formula (3b) represents a cycloalkanediyl group having 7 to 20 carbon atoms, and may also contain an alkyl group as a side chain. This cycloalkanediyl group is preferably having 7 to 15 carbon atoms, more preferably having 7 to 12 carbon atoms, and particularly preferably having 7 to 9 carbon atoms. As such a cycloalkanediyl group, specifically, for example, 3-methylcyclohexanediyl (7 carbon atoms), 4-methylcyclohexanediyl (7 carbon atoms), 3,3,5-trimethylcyclohexanediyl (9 carbon atoms), cyclododecanediyl (12 carbon atoms) can be cited. It is preferably 3-methylcyclohexanediyl (7 carbon atoms), 4-methylcyclohexanediyl (7 carbon atoms) or 3,3,5-trimethylcyclohexanediyl (9 carbon atoms), more preferably 3-methylcyclohexanediyl (7 carbon atoms) or 3,3,5-trimethylcyclohexanediyl (9 carbon atoms), and particularly preferably 3,3,5-trimethylcyclohexanediyl (9 carbon atoms).

[0107] As specific examples of the ester compound represented by the general formula (3), compounds (p-139) to (p-177) having the following chemical structures are shown.

[0108] The ester compound represented by the general formula (3) is preferably one compound selected from compounds (p-139) to (p-177), and among these, compounds (p-139), (p-142), (p-145), (p-148), (p-151), (p-154), or (p-172) are particularly preferred.

[0109] [Chemical formula 30]

[0110] [Chemical formula 31]

[0111] [Chemical formula 32]

[0112] [Chemical formula 33]

[0113] <Manufacturing method of the ester compound represented by the general formula (3)> The ester compound represented by the general formula (3) of the present invention can be manufactured in the same manner as the manufacturing method of the ester compound represented by the general formula (1).

[0114] Specifically, for the ester compound represented by the general formula (3), there are no particular limitations on the starting materials and manufacturing methods in its manufacture. For example, as exemplified by the following reaction formula, the following manufacturing methods can be listed: in the esterification step of synthesizing the ester compound represented by the general formula (10) by reacting the bisphenol compound represented by the general formula (9) with the acid anhydride represented by the general formula (6), after synthesizing the ester compound represented by the general formula (10), an ester exchange reaction step of reacting the ester compound represented by the general formula (10) with the furan carboxylic acid-containing compound represented by the general formula (8) to obtain the ester compound represented by the general formula (3) is used to obtain the manufacturing method of the ester compound represented by the general formula (3).

[0115] [Chemical formula 34]

[0116] (Y in the general formulas (9) and (10) has the same definition as that in the general formula (3), R in the general formula (8) 2 and R 3 have the same definition as that in the general formula (1), and R in the general formulas (6), (7), and (10) 6 has the same definition as that in the general formula (2).) (Esterification step) The reaction method of the esterification step in the above manufacturing method can be applied to the methods of esterification reactions known in the past.

[0117] As the bisphenol compound represented by the general formula (9), specifically, for the compound when Y is the general formula (3a), examples include: 4,4'-dihydroxy-3,3'-dimethylbiphenyl, 4,4'-dihydroxy-3,3',5,5'-tetramethylbiphenyl, 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl; for the compound when Y is the general formula (3b), examples include: bisphenol TMC (1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane), 1,1-bis(4-hydroxyphenyl)-3-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)-4-methylcyclohexane, 1,1-bis(4-hydroxyphenyl)cyclododecane.

[0118] As the acid anhydride represented by the general formula (6), specific examples include acetic anhydride and benzoic anhydride.

[0119] In the above manufacturing method, as the usage amount of the acid anhydride represented by the general formula (6), relative to 1 mole of the bisphenol compound represented by the general formula (9), it is preferably in the range of 2.0 to 10.0 moles, more preferably in the range of 2.0 to 8.0 moles, and still more preferably in the range of 2.0 to 4.0 moles.

[0120] The reaction temperature is generally in the range of 50 to 150 °C, preferably in the range of 80 to 140 °C. The reaction pressure can be either under normal pressure or reduced pressure.

[0121] Through the above esterification process, the ester compound represented by the general formula (10) can be manufactured.

[0122] Y in the general formula (10) has the same definition as that in the general formula (3), and the preferred forms are also the same.

[0123] R in the general formula (10) 6 has the same definition as that in the general formula (2), and the specific examples and preferred forms are also the same.

[0124] The ester compound represented by the general formula (10) obtained from the esterification process can be directly used in the state where it is contained in the reaction solution of the esterification reaction as a raw material for the subsequent transesterification reaction process, or can be used after purification by distilling off the carboxylic acid represented by the general formula (7) generated in the esterification reaction, or can be used after purification by performing a crystallization operation by mixing a solvent into the esterification reaction solution.

[0125] (Transesterification reaction process) The reaction method of the transesterification reaction process in the above manufacturing method can apply the methods of transesterification reactions known in the past.

[0126] R in the general formula (8) 2 and R 3It is the same as the definition of the general formula (1), and the preferred forms or specific examples are also the same.

[0127] As the furan carboxylic acid represented by the general formula (8), specifically, for example, 2-furan carboxylic acid, 3-furan carboxylic acid, 2-methyl-3-furan carboxylic acid, 3-methyl-2-furan carboxylic acid can be cited.

[0128] As the usage amount of the furan carboxylic acid represented by the general formula (8), relative to 1 mole of the ester compound represented by the general formula (10), it is preferably in the range of 2.0 to 10.0 moles, more preferably in the range of 2.0 to 8.0 moles, and further preferably in the range of 2.0 to 4.0 moles.

[0129] As the catalyst in the reaction of the ester compound represented by the general formula (10) and the furan carboxylic acid represented by the general formula (8), a base is preferably used. Specifically, for these bases, for example, organic bases such as amine bases, inorganic alkali metal compounds such as hydroxides, carbonates, and bicarbonate compounds of alkali metals, organic alkali metal compounds such as alcohols, phenols, and salts with organic carboxylic acids of alkali metals, etc. can be cited. In addition, mixtures thereof, etc. can also be cited, but it is not limited thereto.

[0130] The reaction is usually carried out in the presence of a solvent. For reasons such as improving the operability or reaction rate during industrial production, it is preferable to use a reaction solvent during the reaction. As the solvent that can be used, there is no particular limitation as long as it does not distill out of the reaction vessel at the following reaction temperature and is inactive for the transesterification reaction. Specifically, for example, aromatic hydrocarbon ether solvents such as alkyl aryl ethers like phenetole and butyl phenyl ether or diaryl ethers like diphenyl ether and di-p-tolyl ether; aromatic hydrocarbons such as biphenyl and terphenyl; alkyl-substituted naphthalenes such as diisopropylnaphthalene; aliphatic hydrocarbons such as decalin and kerosene; polyalkylene glycol ethers such as tetraethylene glycol dimethyl ether and diethylene glycol dibutyl ether; organic solvents such as Therm-S series (manufactured by Nippon Steel Chemical Co., Ltd.), KSK-OIL series (manufactured by Soken Chemical & Engineering Co., Ltd.), or NeoSK-OIL series (manufactured by Soken Chemical & Engineering Co., Ltd.). In addition, the usage amount of the solvent is not particularly limited as long as it does not hinder the reaction, and it is usually used in the range of 0.5 to 20 weight times, preferably in the range of 1 to 10 weight times, relative to the ester compound represented by the general formula (10).

[0131] The reaction temperature is usually carried out in the range of 40 to 260 °C, preferably in the range of 80 to 255 °C, more preferably in the range of 120 to 250 °C, further preferably in the range of 160 to 245 °C, and particularly preferably in the range of 180 to 240 °C.

[0132] The reaction pressure can be carried out under normal pressure conditions. In addition, it can also be carried out under pressure or reduced pressure.

[0133] As another method, it may also include the step of discharging the carboxylic acid represented by the general formula (7) generated in the reaction out of the system. The step of removing the generated carboxylic acid represented by the general formula (7) from the reaction solution is not particularly limited, and can be carried out by distilling the generated carboxylic acid represented by the general formula (7) together with the solvent in the reaction solution. The generated carboxylic acid represented by the general formula (7) can be discharged out of the reaction system, for example, by using an isobaric dropping funnel equipped with a stopcock, a Dimroth condenser, a Dean-Stark apparatus, etc.

[0134] Regarding the obtained reaction-terminated mixture, after the reaction is terminated, the ester compound represented by the general formula (3) can be obtained from this mixture by a known method. For example, after the reaction, it can be considered to cool and crystallize the reaction mixture and obtain the target powder or granular product by filtration. In addition, it can also be considered to add the reaction mixture to a poor solvent to obtain the precipitated target product, or add a solvent to the reaction mixture for crystallization and then obtain the target powder or granular product by filtration.

[0135] The ester compound represented by the general formula (3) extracted by the above method can be made into a high-purity product, for example, by common purification methods such as washing with a solvent or water or recrystallization. As the solvent that can be used for crystallization and slurrying, there is no particular limitation as long as it is a solvent that is inactive with respect to the ester compound represented by the general formula (3). Specifically, examples include alcohol solvents such as methanol, ethanol, isopropyl alcohol, 1-butanol, etc.; carbonyl solvents such as acetic anhydride, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, etc.; ether solvents such as tetrahydrofuran, methyl isobutyl ether, methyl isopropyl ether, diphenyl ether, etc.; aromatic non-polar solvents such as toluene, xylene, ethylbenzene, etc.; γ-butyrolactone, γ-valerolactone, acrylonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, etc. Among them, 1-butanol, isopropyl alcohol, diphenyl ether, etc. are preferred.

[0136] The conditions for crystallization vary depending on the solvent used and cannot be generalized. For example, when using 1-butanol, the amount of this solvent used is in the range of 1 to 50 parts by weight, more preferably in the range of 2 to 30 parts by weight, and particularly preferably in the range of 2 to 10 parts by weight, relative to 1 part by weight of the total amount of the composition containing the ester compound represented by the general formula (3) to be refined and other impurities. The temperature during dissolution is in the range of 50 to 250 °C, more preferably in the range of 70 to 230 °C, further preferably in the range of 80 to 200 °C, and particularly preferably in the range of 90 to 180 °C. The cooling temperature is in the range of 0 °C to 50 °C, more preferably in the range of 10 to 40 °C, and further preferably in the range of 15 to 35 °C. The pressure during crystallization can be carried out under normal pressure conditions. In addition, it can also be carried out under pressure.

[0137] When using other solvents, various conditions can be appropriately changed by considering the boiling point of the solvent, or the solubility of the ester compound represented by the general formula (3) to be refined, other impurities, and the composition containing these.

[0138] Since the refined product obtained by these refining processes sometimes contains the solvent used, it is preferable to remove the solvent and perform drying. The method for removing the solvent is not particularly limited, and examples thereof include heating under normal pressure or reduced pressure to distill off the solvent.

[0139] <Crystallization of Compound (p-148)> In the ester compound of the present invention, the crystallization of the compound represented by the formula (p-148) can be treated as a crystalline solid, and it is very useful because of its excellent processability.

[0140] The maximum endothermic peak temperature obtained by differential scanning calorimetry of this crystallization is preferably in the range of 234 to 240 °C, more preferably in the range of 235 to 240 °C, and particularly preferably in the range of 236 to 239 °C.

[0141] <Method for Producing Crystallization of Compound (p-148)> The crystallization of the compound (p-148) produced by the production method of the ester compound represented by the above general formula (3) can be produced by crystallization using a solvent containing an alcohol solvent such as methanol, ethanol, isopropanol, 1-butanol, etc., especially an alcohol solvent having 1 to 4 carbon atoms, and an ether solvent such as tetrahydrofuran, methyl isobutyl ether, methyl isopropyl ether, diphenyl ether, etc., especially an ether solvent having 4 to 12 carbon atoms.

[0142] As the alcohol solvent having 1 to 4 carbon atoms, 1-butanol and isopropanol are particularly preferred, and as the ether solvent having 4 to 12 carbon atoms, diphenyl ether is particularly preferred.

[0143] Regarding the crystallization conditions, the total amount of the alcohol solvent and the ether solvent used is in the range of 1 to 50 parts by weight, more preferably in the range of 2 to 30 parts by weight, and particularly preferably in the range of 2 to 10 parts by weight, relative to 1 part by weight of the total amount of the composition containing the compound (p-148) and other reaction impurities.

[0144] Regarding the use ratio of the alcohol solvent to the ether solvent, the amount of the ether solvent used is preferably 0.3 to 3.0 times by weight, more preferably 0.5 to 2.5 times by weight, further preferably 1.0 to 2.2 times by weight, and particularly preferably 1.4 to 2.2 times by weight, relative to the amount of the alcohol solvent used.

[0145] The temperature during dissolution is in the range of 50 to 250 °C, more preferably in the range of 70 to 230 °C, still more preferably in the range of 80 to 200 °C, and particularly preferably in the range of 90 to 180 °C. The cooling temperature is in the range of 0 °C to 50 °C, more preferably in the range of 10 to 40 °C, still more preferably in the range of 15 to 35 °C. The pressure during crystallization can be carried out under normal pressure conditions. In addition, it can also be carried out under pressure.

[0146] The crystals obtained by crystallization may sometimes contain the solvent used, so it is preferable to remove the solvent and carry out drying. The method for removing the solvent is not particularly limited. For example, methods such as heating under normal pressure or reduced pressure to distill off the solvent can be cited.

[0147] <Crystals of Compound (p-151)> Among the ester compounds of the present invention, the crystals of the compound represented by formula (p-151) can be treated as crystalline solids, and are very useful because of their excellent processability.

[0148] The maximum endothermic peak temperature obtained by differential scanning calorimetry of the crystals is preferably in the range of 180 to 188 °C, more preferably in the range of 181 to 187 °C, and particularly preferably in the range of 182 to 186 °C.

[0149] <Method for Producing Crystals of Compound (p-151)> The crystals of compound (p-151) produced by the method for producing an ester compound represented by the above general formula (3) can be produced by crystallization using an alcohol solvent such as methanol, ethanol, isopropanol, 1-butanol, etc., especially an alcohol solvent having 1 to 4 carbon atoms.

[0150] As the alcohol solvent having 1 to 4 carbon atoms, 1-butanol and isopropanol are particularly preferred.

[0151] Regarding the conditions for crystallization, the amount of the alcohol solvent used is in the range of 1 part by weight to 50 parts by weight, more preferably in the range of 2 parts by weight to 30 parts by weight, and particularly preferably in the range of 2 parts by weight to 10 parts by weight, relative to 1 part by weight of the total amount of the composition containing compound (p-151) and other impurities after the reaction.

[0152] The temperature during dissolution is in the range of 50 to 250 °C, more preferably in the range of 70 to 230 °C, still more preferably in the range of 80 to 200 °C, and particularly preferably in the range of 90 to 180 °C. The cooling temperature is in the range of 0 °C to 50 °C, more preferably in the range of 10 to 40 °C, still more preferably in the range of 15 to 35 °C. The pressure during crystallization can be carried out under normal pressure conditions. In addition, it can also be carried out under pressure.

[0153] Crystals obtained by crystallization sometimes contain the solvent used. Therefore, it is preferable to remove the solvent and dry the crystals. The method for removing the solvent is not particularly limited, and examples thereof include heating under normal pressure or reduced pressure to distill off the solvent.

[0154] <Ester compound composition for resin raw material> The ester compound represented by the general formula (3) can also be used in the form of a composition for resin raw materials that further contains the ester compound represented by the general formula (2).

[0155] In addition, the ester compound represented by the general formula (2) further contained in the composition for resin raw materials may be the ester compound represented by the general formula (10), and this case is more preferable.

[0156] In this composition for resin raw materials, with respect to 100 parts by weight of the ester compound represented by the general formula (3), it preferably contains 0.1 to 400 parts by weight of the ester compound represented by the general formula (2), more preferably contains 0.1 to 200 parts by weight, further preferably contains 0.1 to 150 parts by weight, more preferably contains 0.1 to 100 parts by weight, and particularly preferably contains 0.1 to 10 parts by weight.

[0157] The composition for resin raw materials of the present invention can also be produced by mixing the ester compound represented by the general formula (3) and the ester compound represented by the general formula (2) separately produced in a desired amount, or the ester compound represented by the general formula (2) can be used as an intermediate for producing the ester compound represented by the general formula (3), and the reaction rate of the transesterification reaction with the furan carboxylic acid-containing ester represented by the general formula (8) can be adjusted to achieve the desired amount for production.

[0158] The ester compound composition for resin raw materials containing the ester compound represented by the general formula (3) and the ester compound represented by the general formula (2) can be used, like a curable composition described later, for example, to react with a thermosetting compound and / or a compound having a radically polymerizable substituent to produce a cured product. In addition, in the production of an epoxy resin obtained by reacting the ester compound represented by the general formula (3), an ester compound composition for resin raw materials that further contains the ester compound represented by the general formula (2) can also be used.

[0159] <Epoxy resin obtained by reacting the ester compound represented by the general formula (3)> The ester compound represented by the general formula (3) of the present invention can react with an aromatic diglycidyl ether compound (for example, a compound obtained by glycidylating the hydroxyl groups of hydroquinone, resorcinol, catechol, a bisphenol compound represented by the general formula (5), etc.) to obtain an epoxy resin. In the state of having an epoxy group at the molecular terminal, in order to facilitate high molecular weightization, the reaction is preferably carried out using an amount in the range of (epoxy group):(ester group)=1~1.2:1 in terms of the blending equivalent ratio.

[0160] As the epoxy resin obtained by reacting the ester compound represented by the general formula (3), there can also be mentioned: an epoxy resin obtained by reacting with a mixture containing an aromatic dihydroxy compound and epihalohydrin; or an epoxy resin obtained by polymerizing an aromatic dihydroxy compound and epihalohydrin to obtain a phenoxy resin having an epoxy group and then reacting with the phenoxy resin.

[0161] That is, as the epoxy resin obtained by reacting the ester compound represented by the general formula (3), there can be mentioned: an epoxy resin obtained by reacting any one selected from an aromatic diglycidyl ether compound, a mixture containing an aromatic dihydroxy compound and epihalohydrin, and a phenoxy resin having an epoxy group obtained by polymerizing an aromatic dihydroxy compound and epihalohydrin, with the ester compound represented by the general formula (3).

[0162] (Manufacturing method of epoxy resin obtained by reacting the ester compound represented by the general formula (3)) When synthesizing an epoxy resin by reacting the ester compound represented by the general formula (3), a catalyst can be used. As this catalyst, any compound can be used as long as it has the catalyst ability to promote the reaction between the epoxy group and the ester group. For example, there can be mentioned: tertiary amines, cyclic amines, imidazoles, organic phosphorus compounds, quaternary ammonium salts, etc.

[0163] As specific examples of tertiary amines, there can be mentioned: triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, pyridine, 4-(dimethylamino)pyridine, etc.

[0164] As specific examples of cyclic amines, there can be mentioned: 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, etc.

[0165] As specific examples of imidazoles, there can be mentioned 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, etc.

[0166] As specific examples of the organophosphorus compound, there may be mentioned: tri-n-propylphosphine, tri-n-butylphosphine, triphenylphosphine, tris(p-tolyl)phosphine, tricyclohexylphosphine, tris(tert-butyl)phosphine, tris(p-methoxyphenyl)phosphine, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide and the like.

[0167] Among the catalysts listed above, 4-(dimethylamino)pyridine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, 2-ethyl-4-methylimidazole, tris(p-tolyl)phosphine, tricyclohexylphosphine, tris(tert-butyl)phosphine, tris(p-methoxyphenyl)phosphine are preferred, and 4-(dimethylamino)pyridine, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, 2-ethyl-4-methylimidazole are particularly preferred. In addition, the catalyst may be used alone or in combination of two or more.

[0168] Relative to the amount of the reaction substrate used in the reaction for obtaining an epoxy resin by reacting the ester compound represented by the general formula (3), the amount of the above catalyst used is in the range of 0.001 to 3% by weight. When using these compounds as the catalyst, there is a risk that catalyst residues remain in the obtained curable composition, deteriorating the insulation characteristics of the printed circuit board or shortening the pot life of the composition. Therefore, when using a nitrogen-containing compound as the catalyst, the nitrogen content in the curable composition is preferably 2000 ppm or less, more preferably 1000 ppm or less. In addition, when using a phosphorus-containing compound as the catalyst, the phosphorus content in the curable composition is preferably 2000 ppm or less, further preferably 1000 ppm or less.

[0169] In the step of the synthesis reaction in the production of an epoxy resin by reacting the ester compound represented by the general formula (3) according to the present invention, a reaction solvent can be used. As the solvent, any substance can be used as long as it can dissolve the epoxy resin. For example, there may be mentioned: aromatic hydrocarbon solvents, ketone solvents, amide solvents, glycol ether solvents and the like. The solvent may be used alone or in combination of two or more.

[0170] Specific examples of the aromatic hydrocarbon solvents include benzene, toluene, xylene, etc. Specific examples of the ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, dioxane, etc.

[0171] Specific examples of the amide solvents include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, etc.

[0172] Specific examples of the glycol ether solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, etc.

[0173] In the synthesis reaction during the production of epoxy resin, the solid content concentration is preferably 10 to 95% by weight. In addition, when a highly viscous product is generated during the reaction, a solvent can be additionally added to continue the reaction. After the reaction is completed, the solvent can be removed as needed or further added.

[0174] In the production of epoxy resin, the polymerization reaction is carried out at a reaction temperature at which the catalyst used does not decompose. When the reaction temperature is too high, there is a risk that the catalyst decomposes and the reaction stops, or the generated epoxy resin deteriorates. On the contrary, when the temperature is too low, the reaction may not proceed sufficiently. For these reasons, the reaction temperature is preferably 50 to 250 °C, more preferably 120 to 230 °C. In addition, the reaction time is usually 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 ensured by using an autoclave and carrying out the reaction under high pressure.

[0175] Since the ester compound represented by the general formula (3) is included in the ester compound represented by the general formula (1) and can be used in the same way, the ester compound represented by the general formula (1) will be described below.

[0176] The invention of renaming the ester compound represented by the general formula (1) as the ester compound represented by the general formula (3) is also disclosed below.

[0177] The curable composition of the present invention contains an ester compound represented by the general formula (1), a thermosetting compound, and / or a compound having a radically polymerizable substituent. That is, as the form of the curable composition of the present invention, there are forms containing an ester compound represented by the general formula (1) and a thermosetting compound, forms containing an ester compound represented by the general formula (1) and a compound having a radically polymerizable substituent, and forms containing an ester compound represented by the general formula (1), a thermosetting compound, and a compound having a radically polymerizable substituent.

[0178] In order to supplement or further improve the physical properties or characteristics of the curable composition of the present invention and the cured product obtained therefrom, those skilled in the art who come into contact with the present invention can appropriately and suitably select the aforementioned forms within the scope disclosed in the present invention and the obvious scope, or select or change the compounds used, or adjust their usage amounts, etc.

[0179] Regarding the ester compound represented by the general formula (1) used in the curable composition of the present invention, among the compounds contained in its range, only 1 type can be used, or 2 or more types can be used in combination.

[0180] The ester compound represented by the general formula (1) used in the curable composition of the present invention can also be used in the form of a curable composition further containing an ester compound represented by the general formula (2).

[0181] In this case, relative to 100 parts by weight of the ester compound represented by the general formula (1), it is preferably to contain 0.1 to 400 parts by weight of the aforementioned ester compound represented by the general formula (2), more preferably to contain 0.1 to 200 parts by weight, further preferably to contain 0.1 to 150 parts by weight, more preferably to contain 0.1 to 100 parts by weight, and particularly preferably to contain 0.1 to 10 parts by weight.

[0182] It can also be manufactured by mixing the ester compound represented by the general formula (1) and the ester compound represented by the general formula (2) separately manufactured in a desired amount, or the ester compound represented by the general formula (2) can be used as an intermediate for manufacturing the ester compound represented by the general formula (1), and the reaction rate of the transesterification reaction with the furan carboxylic acid-containing ester represented by the general formula (8) can be adjusted to achieve the desired amount for manufacturing.

[0183] <Thermosetting compound> As the thermosetting compound used in the curable composition of the present invention, conventionally known thermosetting compounds can be used. When listing specific examples, they are one or more compounds selected from epoxy resins, benzoxazine compounds, benzoxazine resins, phenolic resins, bismaleimide compounds, and maleimide resins.

[0184] Epoxy resins, benzoxazine compounds, benzoxazine resins, phenolic resins, bismaleimide compounds, and maleimide resins can each use various compounds including those known in the past.

[0185] (Epoxy resin) Regarding epoxy resins, glycidyl ether compounds, aromatic diglycidyl ether compounds (for example, compounds obtained by glycidylating the hydroxyl groups of hydroquinone, resorcinol, catechol, bisphenol compounds represented by the general formula (5), etc.), or phenoxy resins having an epoxy group obtained by polymerizing an aromatic dihydroxy compound (for example, hydroquinone, resorcinol, catechol, bisphenol compounds represented by the general formula (5), etc.) with epihalohydrin with or without using an active ester curing agent are also included in epoxy resins, and various epoxy resins including those known in the past can be used. Epoxy resins obtained by reacting the ester compound represented by the general formula (1) of the present invention as the active ester curing agent can also be used, and these epoxy resins are preferably used. These can be used alone or as a mixture of two or more.

[0186] As the epoxy resins known in the past used, those having two or more epoxy groups in the molecule are preferred. For example, various epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, bisphenol Z type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene type epoxy resin, and phenoxy resin can be used.

[0187] When using the epoxy resin obtained by reacting the ester compound represented by the general formula (1) in combination with other epoxy resins, in the total epoxy resin component, the blending amount of the other epoxy resins is preferably 1% by weight or more, more preferably 5% by weight or more, further preferably 10% by weight or more, and on the other hand, preferably 99% by weight or less, more preferably 95% by weight or less, further preferably 90% by weight or less. By making the proportion of the other epoxy resins above the lower limit value, the effect of improving the physical properties brought about by blending the other epoxy resins can be fully obtained. On the other hand, by making the proportion of the other epoxy resins below the upper limit value, the effect of the epoxy resin of the present invention can be fully exerted, which is preferable from the perspective of obtaining film-forming properties.

[0188] The amount of the epoxy resin obtained by reacting the ester compound represented by the general formula (1) or other epoxy resins used is based on the amount after removing the solvent in the case of containing a solvent.

[0189] (Epoxy resin obtained by reacting the ester compound represented by the general formula (1)) The epoxy resin formed by reacting the ester compound represented by the general formula (1) of the present invention can be obtained, for example, by reacting an aromatic diglycidyl ether compound (e.g., a compound obtained by glycidylating the hydroxyl groups of hydroquinone, resorcinol, catechol, a bisphenol compound represented by the general formula (5), etc.) with the ester compound represented by the general formula (1). In the state of having an epoxy group at the molecular terminal, in order to facilitate high molecular weightization, the reaction is preferably carried out using an amount in the range of (epoxy group):(ester group) = 1 to 1.2:1 in terms of the blending equivalent ratio.

[0190] As another method, there may also be mentioned: a method of reacting a mixture containing an aromatic dihydroxy compound and epihalohydrin with the ester compound represented by the general formula (1); or a method of polymerizing an aromatic dihydroxy compound and epihalohydrin to obtain a phenoxy resin having an epoxy group and reacting it with the ester compound represented by the general formula (1).

[0191] That is, the epoxy resin formed by reacting the ester compound represented by the general formula (1) may include: an epoxy resin formed by reacting any one selected from an aromatic diglycidyl ether compound, a mixture containing an aromatic dihydroxy compound and epihalohydrin, and a phenoxy resin having an epoxy group formed by polymerizing an aromatic dihydroxy compound and epihalohydrin with the ester compound represented by the general formula (1).

[0192] When synthesizing an epoxy resin by reacting the ester compound represented by the general formula (1), a catalyst can be used. As this catalyst, any compound can be used as long as it has the catalytic ability to promote the reaction between the epoxy group and the ester group. For example, there may be mentioned: tertiary amines, cyclic amines, imidazoles, organophosphorus compounds, quaternary ammonium salts, etc.

[0193] Specific examples of the tertiary amines may include: triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, pyridine, 4-(dimethylamino)pyridine, etc.

[0194] Specific examples of the cyclic amines may include: 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, etc.

[0195] Specific examples of the imidazoles may include: 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, etc.

[0196] Specific examples of the organophosphorus compound include: tri-n-propylphosphine, tri-n-butylphosphine, triphenylphosphine, tris(p-tolyl)phosphine, tricyclohexylphosphine, tris(tert-butyl)phosphine, tris(p-methoxyphenyl)phosphine, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, triphenylbenzylphosphonium bromide, etc.

[0197] Among the catalysts listed above, 4-(dimethylamino)pyridine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, 2-ethyl-4-methylimidazole, tris(p-tolyl)phosphine, tricyclohexylphosphine, tris(tert-butyl)phosphine, tris(p-methoxyphenyl)phosphine are preferred, and 4-(dimethylamino)pyridine, 1,8-diazabicyclo[5,4,0]-7-undecene, 1,5-diazabicyclo[4,3,0]-5-nonene, 2-ethyl-4-methylimidazole are particularly preferred. In addition, only one kind of catalyst can be used, or two or more kinds can be used in combination.

[0198] Relative to the usage amount of the reaction substrate used in the reaction for obtaining the epoxy resin by reacting the ester compound represented by the general formula (1), the usage amount of the above catalyst is in the range of 0.001 to 3% by weight. When using these compounds as catalysts, there is a risk that catalyst residues remain in the obtained curable composition, deteriorating the insulation properties of the printed circuit board or shortening the pot life of the composition. Therefore, when using a nitrogen-containing compound as a catalyst, the nitrogen content in the curable composition is preferably 2000 ppm or less, more preferably 1000 ppm or less. In addition, when using a phosphorus-containing compound as a catalyst, the phosphorus content in the curable composition is preferably 2000 ppm or less, further preferably 1000 ppm or less.

[0199] In the synthesis reaction process for manufacturing the epoxy resin formed by reacting the ester compound represented by the general formula (1) according to the present invention, a reaction solvent can be used. As this solvent, any substance can be used as long as it can dissolve the epoxy resin. For example, aromatic hydrocarbon solvents, ketone solvents, amide solvents, glycol ether solvents, etc. can be cited. Only one kind of solvent can be used, or two or more kinds can be used in combination.

[0200] Specific examples of aromatic hydrocarbon solvents include benzene, toluene, xylene, etc. Specific examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, dioxane, etc.

[0201] Specific examples of amide solvents include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, etc.

[0202] Specific examples of glycol ether solvents include: ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monon-butyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monon-butyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monon-butyl ether, propylene glycol monomethyl ether acetate, etc.

[0203] In the synthesis reaction during the manufacture of epoxy resin, the solid content concentration is preferably 10 to 95% by weight. In addition, when a highly viscous product is formed during the reaction, a solvent can be additionally added to continue the reaction. After the reaction is completed, the solvent can be removed as needed or further added.

[0204] In the manufacture of epoxy resin, the polymerization reaction is carried out at a reaction temperature at which the catalyst used does not decompose. When the reaction temperature is too high, there is a risk that the catalyst decomposes and the reaction stops, or the epoxy resin produced deteriorates. On the contrary, when the temperature is too low, the reaction may not proceed sufficiently. For these reasons, the reaction temperature is preferably 50 to 250 °C, more preferably 120 to 230 °C. In addition, the reaction time is usually 1 to 12 hours, preferably 3 to 10 hours. When using a low-boiling solvent such as acetone or methyl ethyl ketone, by using an autoclave and carrying out the reaction under high pressure, a reaction temperature higher than the boiling point at normal pressure can be ensured.

[0205] <Compound with a radically polymerizable substituent> As the compound with a radically polymerizable substituent used in the curable composition of the present invention, conventionally known compounds can be used. When listing specific examples, it is one or more compounds selected from diallyl phthalate resin, diallyl phthalate compound, polyphenylene ether resin with a radically polymerizable substituent, and vinyl compound.

[0206] For diallyl phthalate resin, diallyl phthalate compound, polyphenylene ether resin with a radically polymerizable substituent, and vinyl compound, various compounds including conventionally known compounds can be used.

[0207] <Content of thermosetting compound and / or compound having radically polymerizable substituent> In the curable composition of the present invention, relative to 100 parts by weight of the ester compound represented by the general formula (1), the content of the thermosetting compound and / or the compound having a radically polymerizable substituent is preferably contained in the range of 50 to 500 parts by weight, more preferably contained in the range of 50 to 400 parts by weight, still more preferably contained in the range of 50 to 300 parts by weight, and particularly preferably contained in the range of 50 to 200 parts by weight.

[0208] That is, when the curable composition of the present invention is in the form containing the ester compound represented by the general formula (1) and the thermosetting compound, it means that relative to 100 parts by weight of the ester compound represented by the general formula (1), the thermosetting compound is contained in the above range. When it is in the form containing the ester compound represented by the general formula (1) and the compound having a radically polymerizable substituent, it means that relative to 100 parts by weight of the ester compound represented by the general formula (1), the compound having a radically polymerizable substituent is contained in the above range. When it is in the form containing the ester compound represented by the general formula (1), the thermosetting compound, and the compound having a radically polymerizable substituent, it means that relative to 100 parts by weight of the ester compound represented by the general formula (1), the total amount of the thermosetting compound and the compound having a radically polymerizable substituent is contained in the above range.

[0209] In addition, when the ester compound represented by the general formula (2) is used in combination, it can be alternatively referred to as the content relative to 100 parts by weight of the total amount of the ester compound represented by the general formula (1) and the ester compound represented by the general formula (2).

[0210] <Additive> The curable composition of the present invention may further contain various additives such as an ultraviolet absorber, an antioxidant, a coupling agent, a plasticizer, a soldering flux, a flame retardant, a colorant, a dispersant, an emulsifier, a low elasticizer, a diluent, a defoaming agent, an ion scavenger, an inorganic filler, and an organic filler as needed. The type or amount of the additive used can be appropriately adjusted according to its use purpose.

[0211] <Curing agent> The curable composition of the present invention may further contain a curing agent.

[0212] When an epoxy resin is used as a component of the curable composition of the present invention, the so-called curing agent includes substances that contribute to the crosslinking reaction and / or chain length extension reaction between the epoxy groups of the epoxy resin. In this case, as long as it is a substance generally called a "curing accelerator" and contributes to the crosslinking reaction and / or chain length extension reaction between the epoxy groups of the epoxy resin, it is included in the curing agent.

[0213] The amount of the curing agent used is preferably 0.1 to 100 parts by weight, more preferably 80 parts by weight or less, and still more preferably 60 parts by weight or less, based on 100 parts by weight of the total amount of the ester compound represented by the general formula (1), the thermosetting resin, and / or the compound having a radically polymerizable substituent used.

[0214] There is no particular limitation on the curing agent used, and all types known as curing agents for thermosetting resins or compounds having a radically polymerizable substituent can be used.

[0215] As specific examples of the curing agent used in the curable composition of the present invention when an epoxy resin is used, from the viewpoint of improving heat resistance, phenolic curing agents, amide curing agents, imidazoles, and active ester curing agents are preferably cited. Examples of phenolic curing agents, amide curing agents, imidazoles, active ester curing agents, and other curable agents that can be used are listed below.

[0216] (Phenolic curing agents) When a phenolic curing agent is used as the curing agent, it is more preferable from the viewpoints of improving the processability of the resulting curable composition and the heat resistance of the cured product. Specific examples of the phenolic curing agent 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'-dihydroxybenzophenone, 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, tert-butylcatechol, tert-butylhydroquinone, fluoroethanolamine, pyrogallol, tert-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 or polyallylated products of the above dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac, allylated pyrogallol, etc.

[0217] The phenolic curing agents listed above may be used alone, or two or more of them may be mixed in any combination and ratio. In addition, when the curing agent is a phenolic curing agent, it is preferably used in an equivalent ratio of the functional groups in the curing agent to the epoxy groups in the epoxy resin in the range of 0.8 to 1.5. When it is within this range, it is preferred because unreacted epoxy groups or functional groups of the curing agent are not likely to remain.

[0218] (Amide curing agents) When an amide curing agent is used as the curing agent, it is preferred from the perspective of improving heat resistance, etc. By using an amide curing agent as the curing agent, it is preferred from the perspective of improving the heat resistance of the resulting curable composition. Examples of amide curing agents include dicyandiamide and its derivatives, polyamide resins, etc. Specific examples of amide curing agents include "LUCKAMIDE" N-153-IM-65, EA-330, TD-960 (manufactured by DIC Corporation), etc.

[0219] The amide curing agents listed above may be used alone, or two or more of them may be mixed in any combination and ratio. In addition, the amide curing agent is preferably used in the range of 0.1 to 20% by weight based on the total of the epoxy resin and the amide curing agent used in the curable composition.

[0220] (Imidazoles) Using imidazoles as the curing agent is preferred from the perspective of allowing the curing reaction to proceed sufficiently and improving heat resistance. Examples of imidazoles include 2-phenylimidazole, 2-ethyl-4(5)-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct, 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins with the above imidazoles, etc. In addition, since imidazoles have catalytic ability, they are generally also classified as curing accelerators described later, but in the present invention, they are classified as curing agents.

[0221] The imidazoles listed above may be used alone, or two or more of them may be used in any combination and ratio. In addition, the imidazoles are preferably used in the range of 0.1 to 20% by weight based on the total of the epoxy resin and the imidazoles used in the curable composition.

[0222] (Active ester curing agent) When an active ester curing agent is used as the curing agent, it is preferred from the viewpoint of reducing the water absorption of the resulting cured product. As the active ester curing agent, compounds having two or more highly reactive ester groups in one molecule, such as phenolic esters, thiophenolic esters, N-hydroxyamine esters, esters of heterocyclic hydroxy compounds, etc., are preferred. Among them, phenolic esters obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group are more preferred. Specific examples of the carboxylic acid compound include: benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc. Specific examples of the aromatic compound having a phenolic hydroxyl group include: catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzene triol, dicyclopentadienyl diphenol, phenol novolac, etc. In addition, the ester compound represented by the general formula (2) according to the present invention may also be used.

[0223] The active ester curing agents listed above may be used alone, or two or more of them may be used in any combination and ratio. In addition, in terms of the equivalent ratio of the active ester group in the curing agent to the epoxy group in the epoxy resin used in the curable composition, the active ester curing agent is preferably used in the range of 0.2 to 2.0.

[0224] (Other curing agents) As the curing agent that can be used in the curable composition of the present invention, substances other than phenolic curing agents, amide curing agents and imidazoles, for example, include: amine curing agents (except tertiary amines), acid anhydride curing agents, tertiary amines, organic phosphines, phosphonium salts, tetraphenylborate salts, organic acid dihydrazides, boron halide amine complexes, polythiol curing agents, isocyanate curing agents, blocked isocyanate curing agents, etc. The other curing agents listed above may be used alone, or two or more of them may be used in any combination and ratio.

[0225] In addition, as the curing agent that can be used when a compound having a radically polymerizable group is used, for example, include: imidazoles, tertiary amines, quaternary ammonium salts, ionic catalysts such as boron trifluoride amine complexes, organic phosphines, organic phosphonium salts, organic peroxides such as di-tert-butyl peroxide, dilauroyl peroxide, dibenzoyl peroxide, diisopropylbenzene peroxide, tert-butyl peroxybenzoate, hydroperoxides, radical polymerization initiators such as azobisisobutyronitrile, etc.

[0226] In the curable composition of the present invention, when an epoxy resin and other compounds (thermosetting compounds other than the epoxy resin obtained by reacting the ester compound represented by the general formula (1) or a compound having a radically polymerizable substituent) obtained by reacting the ester compound represented by the general formula (1) are used as one component of the thermosetting compound, in the total epoxy resin component based on solid content, the blending amount of the other compound is preferably 1% by weight or more, more preferably 5% by weight or more, still more preferably 10% by weight or more, and on the other hand preferably 99% by weight or less, more preferably 95% by weight or less, still more preferably 90% by weight or less. By making the proportion of the other compound be above the above lower limit value, the effect of improving physical properties brought about by blending the other compound can be sufficiently obtained. On the other hand, by making the proportion of the other compound be below the above upper limit value, the effect of the epoxy resin of the present invention can be fully exerted, which is preferable from the viewpoint of obtaining film-forming properties.

[0227] <Solvent> In the curable composition of the present invention, during the treatment at the time of film formation, in order to appropriately adjust the viscosity of the curable composition, a solvent may be further blended for dilution. In the curable composition of the present invention, the solvent is used to ensure the processability and workability of the curable composition during shaping, and its usage amount is not particularly limited.

[0228] Examples of the solvent that can be contained in the curable composition of the present invention include: ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate; ethers such as ethylene glycol monomethyl ether; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; alcohols such as methanol and ethanol; alkanes such as hexane and cyclohexane; aromatic compounds such as toluene and xylene, etc. The solvents listed above may be used alone, or two or more kinds may be mixed in any combination and ratio.

[0229] <Cured product> The cured product obtained by curing the curable composition of the present invention has excellent dielectric properties and heat resistance. Here, the so-called "curing" means intentionally curing the epoxy resin composition by heat and / or light, etc., and the degree of curing can be controlled according to the desired physical properties and uses. The degree of progress can be in a state of complete curing or semi-curing, and there is no particular limitation. As the reaction rate of the curing reaction, it is usually 5 to 95%.

[0230] <Curing method> The curing method of the curable composition of the present invention varies depending on the formulation components or formulation amounts in the curable composition, and generally, heating conditions of heating at 80 to 280 °C for 60 to 360 minutes can be cited. This heating is preferably a two-stage treatment including a first heating at 80 to 160 °C for 10 to 90 minutes and a second heating at 120 to 200 °C for 60 to 150 minutes. In addition, in a formulation system where the glass transition temperature (Tg) exceeds the second heating temperature, a third heating at 150 to 280 °C for 60 to 120 minutes is further preferred. Performing the second heating and the third heating in this way is preferred from the perspective of reducing curing defects or solvent residues.

[0231] When producing a resin prepreg, it is preferable to carry out the curing reaction of the curable composition by heating or the like to a degree that can maintain the shape. When the curable composition contains a solvent, most of the solvent is usually removed by methods such as heating, reduced pressure, and air drying, but the resin prepreg may also contain 5% by mass or less of the solvent.

[0232] <Usage> The epoxy resin obtained by reacting the ester compound represented by the general formula (1) according to the present invention has excellent film-forming properties. Therefore, it can be applied to various fields such as adhesives, coatings, civil engineering and building materials, and insulating materials for electrical and electronic components, and is particularly useful as insulating potting, laminating materials, and sealing materials in the electrical and electronic fields.

[0233] As an example of the uses of the epoxy resin obtained by reacting the ester compound represented by the general formula (1) according to the present invention, the curable composition of the present invention, and its cured product, there can be cited: film adhesives, liquid adhesives, composite materials, coatings, civil engineering and building materials, insulating materials for electrical and electronic components, multilayer printed wiring boards, laminates for electrical and electronic circuits such as capacitors, semiconductor sealing materials, underfill materials, chip filling materials for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, insulating potting, etc., but are not limited to these.

[0234] (Laminates for electrical and electronic circuits) As described above, the curable composition of the present invention is suitable for use as laminates for electrical and electronic circuits. In the present invention, the so-called "laminates for electrical and electronic circuits" refers to those in which a layer containing the curable composition of the present invention and a conductive metal layer are laminated. As long as a layer containing the curable composition of the present invention and a conductive metal layer are laminated, even if it is not an electrical and electronic circuit, it can be used in the concept including, for example, capacitors. In addition, in the laminates for electrical and electronic circuits, a layer composed of two or more curable compositions can be formed, and the curable composition of the present invention can be used in at least one layer. In addition, two or more conductive metal layers can also be formed.

[0235] The thickness of the layer composed of the curable composition in the laminate for electrical and electronic circuits is usually about 10 to 200 μm. In addition, the thickness of the conductive metal layer is usually about 0.2 to 70 μm.

[0236] (Conductive metal) Examples of the conductive metal in the laminate for electrical and electronic circuits include metals such as copper and aluminum, or alloys containing these metals. In the conductive metal layer of the laminate for electrical and electronic circuits in the present invention, metal foils of these metals or metal layers formed by plating or sputtering can be used.

[0237] (Manufacturing method of laminate for electrical and electronic circuits) As the manufacturing method of the laminate for electrical and electronic circuits in the present invention, for example, the following methods can be cited.

[0238] (1) Impregnate the curable composition of the present invention into a non-woven fabric or cloth made of inorganic and / or organic fiber materials such as glass fiber, polyester fiber, aramid fiber, cellulose, and nanocellulose to prepare a prepreg. Then, after setting a conductive metal layer by a conductive metal foil and / or plating, a circuit is formed using a photoresist or the like, and the required number of the above layers are overlapped to prepare a laminate.

[0239] (2) Use the prepreg of (1) above as a core material, and laminate a layer composed of a curable composition and a conductive metal layer on top of it (one-sided or two-sided). The layer composed of the curable composition may also contain organic and / or inorganic fillers.

[0240] (3) Without using a core material, only laminate the layer composed of the curable composition and the conductive metal layer alternately to prepare a laminate for electrical and electronic circuits.

[0241] According to the present invention, a cured product having excellent heat resistance and dielectric properties can be provided.

[0242] Therefore, the curable composition of the present invention can be applied to various fields such as film adhesives, liquid adhesives, composite materials, coatings, civil engineering building materials, insulating materials for electrical and electronic components, etc., laminates for electrical and electronic circuits such as multilayer printed wiring boards and capacitors, semiconductor encapsulation materials, underfill materials, chip filling materials for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, insulating potting, etc., and is particularly useful as insulating potting, laminating materials, encapsulation materials, etc. in the electrical and electronic field.

[0243] Examples The present invention will be further specifically described below through examples.

[0244] <Analysis method> 1. Analysis of Reaction Solution Composition and Purity (Ultra-Fast Liquid Chromatography: UFLC) Weigh 0.01 g of the ester compound synthesized in the example into a 50 mL volumetric flask and dilute it with acetonitrile.

[0245] Perform purity analysis on the prepared sample according to the following high-performance liquid chromatography.

[0246] Purity analysis (the analysis value is the area percentage) Measuring device: High-performance liquid chromatography analysis device Prominence UFLC (manufactured by Shimadzu Corporation) Pump: LC-20AD Column oven: CTO-20A Detector: SPD-20A Chromatographic column: HALO-C18 (inner diameter 3 mm, length 75 mm) Oven temperature: 50 °C Flow rate: 0.7 mL / min. Mobile phase: (A) 0.1 vol% acetic acid aqueous solution, (B) acetonitrile Gradient condition: (A) vol% (time from the start of analysis) 30% (2.0 min.) → 100% (15.0 min.) → 100% (18.0 min.) Sample injection volume: 7 μL Detection wavelength: 254 nm 2. Evaluation of Curing Characteristics Evaluate the curing characteristics of the synthesized epoxy resin composition by differential scanning calorimetry (DSC) under the following operating conditions. Set the exothermic peak temperature as the curing temperature.

[0247] [Measurement Conditions] Device: DSC7020 / manufactured by Hitachi High-Technologies Corporation Heating rate: 10 °C / min. Measurement temperature range: 30~350 °C Measurement environment: Nitrogen 50 mL / min. Measurement sample: 3 mg of the synthesized epoxy resin composition 3. Measurement of Glass Transition Temperature (Tg) (Dynamic Viscoelasticity Measurement (DMA)) Device: DMA850 / manufactured by TA Instruments Japan Co., Ltd. Measurement conditions: Three-point bending Measurement temperature: 30~310 °C Measurement frequency: 1.0 (Hz) Sample size: (60 mm × 15 mm × 2 mm) Heating rate: 1.0 °C / min. 4. Evaluation of dielectric properties Using the following device, the relative permittivity and the tangent of the dielectric loss angle were measured for the films (sample size: width 1.5 mm, length 8.0 mm) produced in the examples and comparative examples.

[0248] Measuring device: PNA network analyzer N522B (manufactured by Keysight Technologies, Inc.) Cavity resonator: CP531 for 10 GHz (manufactured by Kanto Electronic Application Development Co., Ltd.) [Measurement conditions] Test method: Based on International Electrotechnical Commission IEC 62180 (cavity resonator perturbation method) Test conditions: Frequency; 10 GHz Number of measurements: n = 2 <Example 1> (Synthesis of the ester compound (p-151) represented by the following Chemical Formula 1-1) [Chemical Formula 35]

[0249] Charge 465 g (1.50 moles) of bisphenol TM and 352 g of acetic anhydride into a 1000 mL four-necked flask equipped with a thermometer, a stirrer, a condenser tube, and a dropping funnel. After replacing the inside of the reaction vessel with nitrogen, set the temperature of the mixed solution to 130 °C. Then, stir at 130 °C for 6 hours. Analyze the composition of the reaction solution by UFLC using the above analysis method. As a result, the proportion of 1,1-bis(4-acetoxyphenyl)-3,3,5-trimethylcyclohexane present in the reaction solution was 96 area%. After completion of the reaction, acetic anhydride and the generated acetic acid were removed by vacuum distillation under the condition of 130 °C. The pressure during distillation was slowly reduced, and finally it became 1.5 kPa. A 560 g (purity: 99.9%) composition containing 1,1-bis(4-acetoxyphenyl)-3,3,5-trimethylcyclohexane was obtained.

[0250] From 1 The analysis result of 1H-NMR confirmed that 1,1-bis(4-acetoxyphenyl)-3,3,5-trimethylcyclohexane was obtained.

[0251] 1 1H-NMR analysis (400 MHz, solvent: CDCl 3 , reference substance: tetramethylsilane) 0.40 (3H, s), 0.85 - 0.89 (1H, t), 0.96 - 0.97 (6H, d), 1.14 - 1.20 (1H, t), 1.37 - 1.40 (1H, d), 1.56 (2H, s), 1.92 - 2.10 (2H, m), 2.25 - 2.27 (6H, d), 2.42 - 2.45 (1H, d), 2.64 - 2.68 (1H, d), 6.90 - 6.92 (2H, d), 6.98 - 7.00 (2H, d), 7.18 - 7.20 (2H, d), 7.31 - 7.34 (2H, d). Into a 3000 mL four-necked flask equipped with a thermometer, a stirrer, a condenser, and a dropping funnel, 300 g (0.76 mol) of 1,1-bis(4-acetoxyphenyl)-3,3,5-trimethylcyclohexane, 213 g of furan carboxylic acid, 4.0 g of 4-dimethylaminopyridine, and 1500 g of diphenyl ether were charged. After purging the inside of the reaction vessel with nitrogen, the temperature of the mixed solution was set to 230 °C. Then, while distilling out the liquid containing diphenyl ether and others such as acetic acid and the solvent generated during the reaction to the outside of the system, the mixture was stirred at 230 °C for 8 hours. By the above analytical method, the composition of the reaction solution was analyzed by UFLC, and as a result, the proportion of the target compound present in the reaction solution was 52 area%. After the reaction was completed, acetic acid, diphenyl ether, and furan carboxylic acid generated were removed by vacuum distillation at 210 °C. The pressure during distillation was slowly reduced and finally set to 5.0 kPa. After cooling the diphenyl ether solution containing the concentrated target compound, 845 g of 1-butanol was added. Then, it was cooled to 70 °C to precipitate crystals. 229 g of 1-butanol was added and it was cooled to 30 °C. The slurry containing the obtained target compound was separated by centrifugal filtration, and the obtained crystals containing the solvent were dried at 80 °C and 2.0 kPa to obtain 337 g of the target compound (1-1) (purity: 99.8%). In addition, from the results of differential scanning calorimetry (DSC) of the target compound, it was found that it was a crystal with a maximum endothermic peak temperature of 183.5 °C. The DSC data is shown in Figure 1 .

[0252] From 1 the analysis results of 1H-NMR, it was confirmed that the target compound having the above structure was obtained.

[0253] 1 1H-NMR analysis (400 MHz, solvent: CDCl 3 , reference substance: tetramethylsilane) 0.39 (3H, s), 0.81 - 0.92 (1H, t), 0.98 - 1.00 (6H, d), 1.18 - 1.24 (1H, t), 1.39 - 1.42 (1H, d), 1.56 (4H, s), 1.96 - 2.10 (2H, m), 2.46 - 2.49 (1H, d), 2.68 - 2.72 (1H, d), 6.57 - 6.59 (2H, m), 7.04 - 7.06 (2H, d), 7.13 - 7.15 (2H, d), 7.24 - 7.33 (1H, m), 7.34 - 7.40 (4H, m), 7.65 - 7.67 (2H, m). Regarding the solvent solubility of the obtained target compound, it shows a solubility of 20 - 40 wt% with respect to the weight of each solution of methyl ethyl ketone, cyclohexanone, and N - methylpyrrolidone, and a solubility of 10 - 20 wt% with respect to the weight of each solution of toluene, propylene glycol monomethyl ether acetate, and ethyl acetate. Therefore, its excellent solvent solubility is confirmed.

[0254] <Example 2> (Synthesis of the ester compound (p - 28) represented by the following chemical formula 1 - 2) [Chemical formula 36]

[0255] After synthesizing diacetylbiphenol by acetylating biphenol in the same manner as in Example 1, 70 g (0.26 mol) of diacetylbiphenol, 72 g of furan carboxylic acid, 1.4 g of 4 - dimethylaminopyridine, and 431 g of diphenyl ether were charged into a 1000 mL four - necked flask equipped with a thermometer, a stirrer, a condenser, and a dropping funnel. After replacing the inside of the reaction vessel with nitrogen, the temperature of the mixed solution was set to 210 °C. Then, while distilling the liquid containing acetic acid and the solvent such as diphenyl ether generated during the reaction out of the system under reduced pressure, the mixture was stirred at 210 °C for 4 hours. The pressure during distillation was slowly reduced, and finally set to 25.0 kPa. The composition of the reaction solution was analyzed by UFLC using the above - mentioned analytical method. As a result, the proportion of the target compound present in the reaction solution was 69 area%. After the reaction was completed, the mixture was cooled to 30 °C to precipitate crystals. The slurry containing the obtained target compound was subjected to solid - liquid separation by centrifugal filtration, and the obtained crystals containing the solvent were dried at 80 °C and 2.0 kPa to obtain 81 g of the target compound (1 - 2) (purity: 99.7%). In addition, from the results of differential scanning calorimetry (DSC) of the target compound, it was found that it is a crystal with a maximum endothermic peak temperature of 240.0 °C. The DSC data is shown in Figure 2 .

[0256] From 1 the analysis results of 1H - NMR, it was confirmed that the target compound with the above structure was obtained.

[0257] 1 1H-NMR analysis (400 MHz, solvent: CDCl 3 , reference substance: tetramethylsilane) 6.82 - 6.83 (2H, dd), 7.37 - 7.40 (4H, dt), 7.60 - 7.61 (2H, dd), 7.76 - 7.80 (4H, dt), 8.13 (2H, s). <Example 3> (Synthesis of the ester compound (p-148) represented by the following Chemical Formula 1-3) [Chemical Formula 37]

[0258] In the same manner as in Example 1, 4,4'-dihydroxy-2,2',3,3',5,5'-hexamethylbiphenyl was acetylated to synthesize 4,4'-diacetoxy-2,2',3,3',5,5'-hexamethylbiphenyl. Then, 204 g (0.58 mol) of 4,4'-diacetoxy-2,2',3,3',5,5'-hexamethylbiphenyl, 162 g of furan carboxylic acid, 3.8 g of 4-dimethylaminopyridine, and 1267 g of diphenyl ether were charged into a 2000 mL four-necked flask equipped with a thermometer, a stirrer, a condenser, and a dropping funnel. After replacing the inside of the reaction vessel with nitrogen, the temperature of the mixed solution was set to 220 °C. Then, while distilling out the liquid containing acetic acid and diphenyl ether, etc. generated during the reaction to the outside of the system, the mixture was stirred at 220 °C for 14 hours. The composition of the reaction solution was analyzed by UFLC using the above analysis method, and as a result, the proportion of the target compound present in the reaction solution was 70 area%. After the reaction was completed, acetic acid, diphenyl ether, and furan carboxylic acid generated were removed by vacuum distillation at 220 °C. The pressure during distillation was slowly reduced, and finally set to 5.0 kPa. After cooling the concentrated diphenyl ether solution containing the target compound, 88 g of isopropanol and 149 g of diphenyl ether were added. Then, it was cooled to 30 °C to precipitate crystals. The slurry containing the obtained target compound was subjected to solid-liquid separation by centrifugal filtration, and the obtained crystals containing the solvent were dried at 60 °C and 2.0 kPa to obtain 233 g of the target compound (purity: 99.4%). In addition, from the results of differential scanning calorimetry (DSC) of the target compound, it was found that it was a crystal with a maximum endothermic peak temperature of 237.7 °C. The DSC data is shown in Figure 3 .

[0259] From 1 the analysis results of 1H-NMR, it was confirmed that the target compound having the above structure was obtained.

[0260] 11H-NMR analysis (400 MHz, solvent: C 2 D 6 OS, reference substance: tetramethylsilane) 1.94 (3H, s), 2.09 (6H, s), 2.11 (6H, s), 6.84 - 6.85 (2H, dd), 6.93 (2H, s), 7.67 - 7.68 (2H, dd), 8.15 - 8.15 (2H, d). <Example 4> 10.0 g of the compound (1 - 1) synthesized in Example 1, 10.1 g of dicyclopentadiene - type epoxy resin (XD - 1000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 251 g / eq.), 0.2 g of 4 - dimethylaminopyridine, and 16.2 g of methyl ethyl ketone were placed in a 100 mL beaker, heated to 70 °C and dissolved. The solution was poured onto a release film and air - dried at room temperature. Then, it was dried in a vacuum dryer at 80 °C and 1.5 kPa, and then pulverized to obtain a composition powder containing the compound (1 - 1) and the epoxy resin. The composition powder was placed in a silicone resin mold and cured at 140 °C / 1 hour, 150 °C / 1 hour, 160 °C / 1.5 hours, 180 °C / 1.5 hours, 250 °C / 2 hours. The glass transition temperature (Tg) of the obtained cured product was measured by the above - mentioned analysis method, and the result was 250.0 °C.

[0261] <Example 5> A mixture of 5.1 g of the compound (1 - 1) synthesized in Example 1 and 5.0 g of 1,1 - bis(4 - acetoxyphenyl) - 3,3,5 - trimethylcyclohexane synthesized in Example 1, 11.4 g of dicyclopentadiene - type epoxy resin (XD - 1000, manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 251 g / eq.), 0.2 g of 4 - dimethylaminopyridine, and 11.1 g of methyl ethyl ketone were placed in a 100 mL beaker, heated to 70 °C and dissolved. The solution was poured onto a release film and air - dried at room temperature. Then, it was dried in a vacuum dryer at 80 °C and 1.5 kPa, and then pulverized to obtain a composition powder containing the compound (1 - 1), 1,1 - bis(4 - acetoxyphenyl) - 3,3,5 - trimethylcyclohexane, and the epoxy resin. The composition powder was placed in a silicone resin mold and cured at 140 °C / 1 hour, 150 °C / 1 hour, 160 °C / 1.5 hours, 180 °C / 1.5 hours. The glass transition temperature (Tg) of the obtained cured product was measured by the above - mentioned analysis method, and the result was 206.3 °C.

[0262] It can be seen from Examples 4 and 5 that when the proportion of the compound represented by the general formula (1) is large, the heat resistance is higher.

[0263] <Example 6> 20.0 g of the compound (1-1) synthesized in Example 1, 16.0 g of o-cresol novolak type epoxy resin (manufactured by DIC Corporation: trade name "Epiclon N-673"), and 40.0 g of methyl ethyl ketone were placed in a 100 mL beaker, stirred, and dissolved. 0.72 g of 4-dimethylaminopyridine was added to the solution and further stirred to dissolve 4-dimethylaminopyridine. After complete dissolution, the solution was transferred to a bucket and dried overnight in a ventilation device, and then dried in a vacuum dryer at 60 °C and 1.5 kPa for 5 hours. Thereafter, the obtained composition was placed in a mold (φ100 mm press-in type), and heated using a hot press tester under the conditions of 3 MPa at 160 °C for 2 hours and 180 °C for 2 hours to obtain a cured product.

[0264] <Comparative Example 1> 10.0 g of a novolak type curing agent (manufactured by Aica Kogyo Co., Ltd.: trade name "BRG-555"), 20.0 g of o-cresol novolak type epoxy resin ((manufactured by DIC Corporation: trade name "Epiclon N-673"), and 40.0 g of methyl ethyl ketone were placed in a 100 mL beaker, stirred, and dissolved. 0.60 g of triphenylphosphine was added to the solution and further stirred to dissolve triphenylphosphine. After complete dissolution, the solution was transferred to a bucket and dried overnight in a ventilation device, and then dried in a vacuum dryer at 60 °C and 1.5 kPa for 5 hours. Thereafter, the obtained composition was placed in a mold (φ100 mm press-in type), and heated using a hot press tester under the conditions of 3 MPa at 100 °C for 1 hour and 130 °C for 2 hours. Then, in a hot air circulation oven, the cured product was heated under the conditions of 140 °C for 2 hours, 150 °C for 2 hours, 160 °C for 2 hours, and 180 °C for 2 hours to obtain a cured product.

[0265] By the above analysis method, the glass transition temperature (Tg) of the cured products obtained in Example 6 and Comparative Example 1 was measured and the dielectric properties were evaluated. The results are summarized in Table 1.

[0266] [Table 1]

[0267] As described above, it can be seen that the epoxy resin cured product using the compound of Example 1 of the present invention as a curing agent has a high glass transition temperature and exhibits high heat resistance. In addition, it can be seen that excellent dielectric properties are also exhibited.

[0268] The ester compound of the present invention, when formulated in an epoxy resin and cured, can endow the resulting cured product with excellent heat resistance and dielectric properties. Regarding the secondary hydroxyl groups generated in the reaction between the epoxy resin and the curing agent, it is speculated that the ester compound represented by the general formula (1) reacts with the epoxy resin as a curing agent and esterifies the secondary hydroxyl groups. As a result, the polarization of the resulting cured product is suppressed, thereby exhibiting excellent dielectric properties.

[0269] Therefore, the epoxy resin composition containing the ester compound of the present invention can be applied to various fields such as adhesives, coatings, civil engineering and building materials, and insulating materials for electrical and electronic components. In particular, it is useful as insulating potting, laminating materials, and sealing materials in the electrical and electronic fields.

[0270] Examples of the uses of the ester compound of the present invention and the epoxy resin composition containing the same include, but are not limited to, laminates for electrical and electronic circuits such as multilayer printed wiring boards and capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor sealing materials, underfill materials, chip filling materials for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, etc.

Claims

1. An ester compound, characterized in that, it is represented by the general formula (3), [Chemical formula 1] In the formula, R 2 each independently represents a single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms, and R 3 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Y represents a divalent group represented by the general formula (3a) or the general formula (3b). [Chemical formula 2] In general formulas (3a) and (3b), R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, * each represents a bonding position, in general formula (3a), m each independently represents an integer of 1 to 4, in general formula (3b), n each independently represents 0 or an integer of 1 to 4, and Z represents a cycloalkanediyl group having 7 to 20 carbon atoms.

2. The ester compound according to claim 1, characterized in that, The R of the ester compound represented by the general formula (3) 2 are all single bonds.

3. The ester compound according to claim 2, characterized in that, Further, the R of the ester compound represented by the general formula (3) 3 are all hydrogen atoms.

4. The ester compound according to claim 3, characterized in that, the ester compound represented by the general formula (3) is compound (p-139), (p-142), (p-145), (p-148), (p-151), (p-154) or (p-172), [Chemical formula 3] 。 5. A crystal of an ester compound of compound (p-148), characterized in that, the compound (p-148) is the compound described in claim 4.

6. The crystal of the ester compound of compound (p-148) according to claim 5, characterized in that, the maximum endothermic peak temperature obtained by differential scanning calorimetry is in the range of 234 to 240 °C.

7. A crystal of an ester compound of compound (p-151), characterized in that, the compound (p-151) is the compound described in claim 4.

8. The crystal of the ester compound of compound (p-151) according to claim 7, characterized in that, the maximum endothermic peak temperature obtained by differential scanning calorimetry is in the range of 180 to 188 °C.

9. An ester compound composition for resin raw materials, characterized in that, it contains the ester compound represented by the general formula (3) described in claim 1 and the ester compound represented by the general formula (2), [Chemical formula 4] In the formula, R 1 each independently represents an alkyl group having 1 to 6 carbon atoms or an aryl group having 6 to 12 carbon atoms, R 6 each independently represents a monovalent hydrocarbon group having 1 to 20 carbon atoms, X represents a single bond, an oxygen atom, a sulfur atom, a sulfonyl group, a carbonyl group or a divalent group represented by the general formula (1a), (1b) or (1c), and n each independently represents 0 or an integer of 1 to 4. [Chemical formula 5] In general formulas (1a), (1b) and (1c), R 4 and R 5 each independently represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a halogenated alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 12 carbon atoms, R 4 and R 5 may be bonded to each other to form a cycloalkanediyl group having 5 to 20 carbon atoms as a whole, Ar 1 and Ar 2 represent an aryl group having 6 to 12 carbon atoms, and * each represents a bonding position.

10. The ester compound composition for resin raw materials according to claim 9, characterized in that, relative to 100 parts by weight of the ester compound represented by the general formula (3), it contains 0.1 to 400 parts by weight of the ester compound represented by the general formula (2).

11. An epoxy resin, characterized in that, it is obtained by reacting the ester compound represented by the general formula (3) described in claim 1 with any one of an aromatic diglycidyl ether compound, a mixture containing an aromatic dihydroxy compound and epihalohydrin, and a phenoxy resin having an epoxy group obtained by polymerizing an aromatic dihydroxy compound and epihalohydrin.

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