Epoxy resin, cured epoxy resin, method for producing cured epoxy resin, and epoxy resin composition

Abstract

To provide an epoxy resin which gives an epoxy resin cured product good in both chemical heat resistance and physical heat resistance.SOLUTION: The epoxy resin is represented by the following formula (1) (where R1-R20 are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, a nitro group, an amino group, an amide group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a formyl group, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group or an aryl group).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin, a cured epoxy resin, a method for producing a cured epoxy resin, and an epoxy resin composition. [Background technology]

[0002] Epoxy resins have excellent heat resistance, mechanical properties, adhesive properties, and electrical insulation properties, and these properties are utilized in a wide range of applications, including adhesives, paints, and construction and civil engineering materials. However, as their use expands to fields such as aircraft materials and semiconductor encapsulation, even higher heat resistance is required. To address this issue, attempts have been made to suppress micro-Brownian motion and improve physical heat resistance by introducing rigid or highly symmetrical skeletons into the molecular structure (Non-Patent Document 1). [Prior art documents] [Non-patent literature]

[0003] [Non-Patent Document 1] Epoxy Resin Technology Association, "Review of Recent Advances in Epoxy Resins", p3-11 (2009) Summary of the Invention [Problem to be solved by the invention]

[0004] Common epoxy resins, such as bisphenol A diglycidyl ether (DGEBA), have a glycidyl ether structure, which contains an -O-CH2- moiety. However, the -O-CH2- moiety is easily thermally decomposed, and the thermal decomposition onset temperature (T d ) decreases, and a decrease in chemical heat resistance is unavoidable. In addition, cured products of epoxy resins with a glycidyl ether structure have many single bonds, as seen in the -O-CH2- moiety, and are prone to rotation of the main chain. For this reason, they are physically unstable and the glass transition temperature (T g ) decreases, and the decrease in physical heat resistance is unavoidable.

[0005] There are also alicyclic epoxy resins that do not contain a glycidyl ether structure, but these epoxy resins have substituents on both carbon atoms of the epoxy ring, so they have low reactivity with curing agents such as polyfunctional amines and polyfunctional phenols. Furthermore, because alicyclic epoxy resins are produced by the oxidation reaction of olefins using peroxides, there are safety concerns during production.

[0006] In view of the above problems, an object of the present invention is to provide an epoxy resin that can give a cured epoxy resin product having good chemical heat resistance and good physical heat resistance. [Means for solving the problem]

[0007] As a result of extensive research, the present inventors have found that the above problems can be solved by providing an epoxy resin represented by any one of the following formulas (1) to (6).

[0008] In one aspect, the present invention is an epoxy resin represented by any one of the following formulas (1) to (6). [ka] [ka] [ka] [ka] [ka] [ka] (In formulas (1) to (6), R 1 ~R 120are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, a nitro group, an amino group, an amido group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a formyl group, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group.

[0009] In another aspect, the present invention provides a cured epoxy resin product obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) above.

[0010] In one embodiment, the cured epoxy resin product of the present invention is obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) above with a curing agent represented by the following formula (7): [ka] (In formula (7), n is a positive integer.)

[0011] In another embodiment, the epoxy resin cured product of the present invention is obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) above with a curing agent represented by the following formula (8): [ka]

[0012] In yet another embodiment, the epoxy resin cured product of the present invention is obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) above with a curing agent represented by the following formula (9): [ka]

[0013] In yet another embodiment, the epoxy resin cured product of the present invention is obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) above with a curing agent represented by the following formula (21): [ka] (In formula (21), X represents a benzene ring, a naphthalene ring, a benzene ring or a naphthalene ring nucleus-substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group; Y represents a benzene ring, a naphthalene ring, a benzene ring or a naphthalene ring nucleus-substituted with an alkyl group having 1 to 4 carbon atoms; Z represents an alkyl group having 1 to 4 carbon atoms; k represents 0 or 1; and n represents an average of 0.25 to 3.0 in repeating units.)

[0014] In yet another aspect, the present invention provides a method for producing a cured epoxy resin by curing an epoxy resin represented by any one of the formulas (1) to (6) above.

[0015] In one embodiment, the method for producing an epoxy resin cured product of the present invention comprises curing an epoxy resin represented by any one of the formulas (1) to (6) with a curing agent represented by the formula (7).

[0016] In another embodiment of the method for producing an epoxy resin cured product of the present invention, an epoxy resin represented by any one of the formulas (1) to (6) is cured with a curing agent represented by the formula (8).

[0017] In yet another embodiment of the method for producing an epoxy resin cured product of the present invention, an epoxy resin represented by any one of the formulas (1) to (6) is cured with a curing agent represented by the formula (9).

[0018] In yet another embodiment of the method for producing an epoxy resin cured product of the present invention, an epoxy resin represented by any one of the formulas (1) to (6) is cured with a curing agent represented by the formula (21).

[0019] In yet another aspect, the present invention provides an epoxy resin composition containing an epoxy resin represented by any one of the formulas (1) to (6) and a curing agent.

[0020] In one embodiment of the epoxy resin composition of the present invention, the curing agent is at least one of the compounds represented by the formulas (7) to (9) and (21). [Effects of the Invention]

[0021] According to the present invention, an epoxy resin can be provided that can give an epoxy resin cured product having good chemical heat resistance and good physical heat resistance. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a graph showing the results of TGA measurement according to Example 2 and Comparative Example 1. [Figure 2] 1 is a graph showing the results of DMA measurements according to Example 2 and Comparative Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0023] Next, embodiments of the present invention will be described in detail with reference to the drawings. It should be understood that the present invention is not limited to the following embodiments, and that appropriate design changes and improvements may be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

[0024] (epoxy resin) The epoxy resin of the present invention is represented by any one of the following formulas (1) to (6). [ka] [ka] [ka] [ka] [ka] [ka]

[0025] In formulas (1) to (6), R 1 ~R 120 are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, a nitro group, an amino group, an amido group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a formyl group, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. 1 ~R 120 and are each more preferably a hydrogen atom, an alkyl group, or a cycloalkyl group.

[0026] The epoxy resin of the present invention may be represented by the following formula (22) or (23):

[0027] [ka]

[0028] [ka]

[0029] In formulas (22) and (23), R 131 ~R 162 are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, a nitro group, an amino group, an amido group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a formyl group, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. 131 ~R 162 More preferably, X is a hydrogen atom, an alkyl group, or a cycloalkyl group. 1 ~X 4are each independently a carbonyl group, an oxygen atom, an amino group, a sulfur atom, a sulfoxide group, a sulfonyl group or a hydrocarbon group having 1 to 12 carbon atoms.

[0030] (cured epoxy resin) The cured epoxy resin material of the present invention is obtained by curing an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23). None of the cured epoxy resin materials obtained by curing the epoxy resins represented by the formulas (1) to (6), (22), and (23) has an -O-CH2- moiety derived from a glycidyl ether structure, which is susceptible to thermal decomposition, in its structure. Therefore, the thermal decomposition onset temperature (T d ) can be prevented from decreasing. In addition, since the cured products of the epoxy resins of the formulas (1) to (6), (22), and (23) do not have an -O-CH2- moiety derived from a glycidyl ether structure in their structure, there are few single bonds and the rotation of the main chain is unlikely to occur. Therefore, they are physically stable and the glass transition temperature (T g ) can be suppressed. Therefore, the cured products of the epoxy resins of the formulas (1) to (6), (22), and (23) have good chemical heat resistance and physical heat resistance. Furthermore, since they are not produced by an oxidation reaction of an olefin using a peroxide, there are no safety concerns during production.

[0031] The curing agent used to cure the epoxy resin in the cured epoxy resin product of the present invention may be any commonly known curing agent for epoxy resins, such as acid anhydride compounds, phenolic compounds, amine compounds, and active ester compounds.

[0032] Examples of the acid anhydride compound curing agent include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, maleic anhydride, maleic anhydride polypropylene glycol, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylnadic anhydride, hexahydrophthalic anhydride, and methylhexahydrophthalic anhydride.

[0033] As the curing agent for the phenolic compound, for example, a curing agent represented by the following formula (10) can be used. [ka]

[0034] In formula (10), m is 0 to 3, and n is a positive integer. 121 R is a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, a nitro group, an amino group, an amido group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a formyl group, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. 122 and R 123 are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group. Other phenolic compounds include dicyclopentadiene-phenol addition type resins, phenol aralkyl resins, naphthol aralkyl resins, triphenylolmethane resins, tetraphenylolethane resins, naphthol novolac resins, naphthol-phenol co-condensed novolac resins, naphthol-cresol co-condensed novolac resins, biphenyl-modified phenolic resins, aminotriazine-modified phenolic resins, and modified products thereof.

[0035] Furthermore, any amine compound, whether aliphatic or aromatic, having three or more N-H bonds can be used as a curing agent for the amine compound. Examples of the amine compound curing agent include aliphatic polyamines such as ethylenediamine, propylenediamine, butylenediamine, hexamethylenediamine, polypropylene glycol diamine, diethylenetriamine, triethylenetetramine, and pentaethylenehexamine; aromatic polyamines such as metaxylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, and phenylenediamine; alicyclic polyamines such as 1,3-bis(aminomethyl)cyclohexane, isophoronediamine, and norbornanediamine; and dicyandiamide.

[0036] Furthermore, in recent years, electronic devices have become smaller and more precise, which has led to a demand for finer and denser substrate wiring, and furthermore, the development of insulating materials with low dielectric loss tangents is desired in order to reduce transmission loss. Against this background, the present inventors have conducted extensive research and found that the cured epoxy resin product according to an embodiment of the present invention, which is produced using an active ester compound as a curing agent, has particularly excellent dielectric properties.

[0037] An active ester compound is a compound having one or more active ester groups per molecule, and can reduce the dielectric loss tangent of a resin composition. The active ester compound used as a curing agent in the present invention is not particularly limited, but compounds having two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds, are generally preferred. The active ester compound is preferably one obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. From the perspective of improving heat resistance, active ester resins obtained from a carboxylic acid compound or its halide and a hydroxy compound are preferred, and active ester resins obtained from a carboxylic acid compound or its halide and a phenol compound and / or a naphthol compound are more preferred. The active ester compound may be linear or multi-branched. Furthermore, if the carboxylic acid compound having at least two or more carboxy groups per molecule contains an aliphatic chain, it can improve compatibility with epoxy resins, and if it contains an aromatic ring, it can improve heat resistance.

[0038] 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, and the like, and halides thereof.

[0039] Examples of phenol compounds or naphthol compounds include hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, dihydroxydiphenyl ether, phenolphthalein, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, polyhydroxynaphthylene ether, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, benzenetriol, and dicyclopentadiene-phenol adduct resins.

[0040] Specific examples of the active ester compound include active ester resins containing a dicyclopentadiene-phenol addition structure, active ester resins containing a naphthalene structure, active ester resins which are acetylated phenol novolac, and active ester resins which are benzoylated phenol novolac. Of these, active ester resins containing a dicyclopentadiene-phenol addition structure and active ester resins containing a naphthalene structure are more preferred because of their excellent ability to improve peel strength. More specific examples of the active ester resins containing a dicyclopentadiene-phenol addition structure include compounds represented by the following formula (21): [ka] (In formula (21), X represents a benzene ring, a naphthalene ring, a benzene ring or a naphthalene ring nucleus-substituted with an alkyl group having 1 to 4 carbon atoms, or a biphenyl group; Y represents a benzene ring, a naphthalene ring, a benzene ring or a naphthalene ring nucleus-substituted with an alkyl group having 1 to 4 carbon atoms; Z represents an alkyl group having 1 to 4 carbon atoms; k represents 0 or 1; and n represents an average of 0.25 to 3.0 in repeating units.)

[0041] From the viewpoint of decreasing the dielectric loss tangent and improving the heat resistance, X is preferably a naphthalene ring, Y is preferably a benzene ring, k is preferably 0, and n is preferably 0.25 to 2.0.

[0042] The active ester compound may be the active ester compound disclosed in JP 2004-277460 A, or may be a commercially available active ester compound. Commercially available active ester compounds include, for example, active ester curing agents containing a dicyclopentadienyl structure, active ester curing agents containing a naphthalene structure, active ester curing agents containing an acetylated product of phenol novolac, and active ester curing agents containing a benzoylated product of phenol novolac. Active ester curing agents containing a naphthalene structure and active ester curing agents containing a dicyclopentadienyl diphenol structure are more preferred. Examples of active ester curing agents containing a dicyclopentadienyl diphenol structure include EXB9451, EXB9460, EXB9460S, HPC-8000-65T (manufactured by DIC Corporation), and HPC-8000L-65TM (manufactured by DIC Corporation). Examples of active ester curing agents containing a naphthalene structure include EXB9416-70BK, HPC-8900-70BK, and HPC-8150-62T (manufactured by DIC Corporation). Examples of active ester curing agents containing an acetylated phenol novolac include DC808 (manufactured by Mitsubishi Chemical Corporation). Examples of active ester curing agents containing a benzoylated phenol novolac include YLH1026 (manufactured by Mitsubishi Chemical Corporation).

[0043] When the number of epoxy groups in an epoxy resin is taken as 1, the number of reactive groups in an active ester compound is preferably 0.2 to 2, more preferably 0.3 to 1.5, and even more preferably 0.4 to 1, from the viewpoint of improving the mechanical properties of the resin composition. Here, the "number of epoxy groups in an epoxy resin" refers to the total value obtained by dividing the solid content mass of each epoxy resin present in the resin composition by the epoxy equivalent, for all epoxy resins. Furthermore, "reactive group" refers to a functional group capable of reacting with an epoxy group, and the "number of reactive groups in an active ester compound" refers to the total value obtained by dividing the solid content mass of active ester compounds present in the resin composition by the reactive group equivalent.

[0044] The cured epoxy resin product of the present invention may be one obtained by repeatedly polymerizing and curing the epoxy resin of the present invention, or may further contain a repeating unit derived from a curing agent. For example, a cured product obtained by curing an epoxy resin represented by formula (1) with a curing accelerator such as an imidazole has a repeating unit represented by the following formula (11), (12), or (13).

[0045] [ka] (In formula (11), m and n are positive integers.)

[0046] [ka] (In equation (12), j is a positive integer.)

[0047] [ka] (In equation (13), k is a positive integer.)

[0048] The cured epoxy resin product of the present invention may be obtained by curing an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) above with a curing agent represented by the following formula (7) (phenol novolac: PN): [ka] (In formula (7), n is a positive integer.)

[0049] The cured epoxy resin of the present invention, which is produced by curing an example of an epoxy resin represented by formula (1) with an example of a curing agent represented by formula (7), ideally contains a repeating unit represented by formula (14). However, there may be cases where some of the epoxy groups and phenolic OH groups remain unreacted.

[0050] [ka]

[0051] The cured epoxy resin product of the present invention may be obtained by curing an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) above with a curing agent represented by the following formula (8) (4,4'-diaminodiphenyl sulfone: DDS). [ka]

[0052] The cured epoxy resin of the present invention, which is prepared by curing an example of an epoxy resin represented by formula (1) with a curing agent represented by formula (8), ideally contains a repeating unit represented by formula (15). However, there may be cases where some of the epoxy groups and amino groups remain unreacted.

[0053] [ka]

[0054] The cured epoxy resin product of the present invention may be obtained by curing an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) above with a curing agent represented by the following formula (9) (m-phenylenediamine: MPDA). [ka]

[0055] The cured epoxy resin of the present invention, which is produced by curing an example of an epoxy resin represented by formula (1) with a curing agent represented by formula (9), ideally contains a repeating unit represented by formula (16). However, there may be cases where some of the epoxy groups and amino groups remain unreacted.

[0056] [ka]

[0057] (Epoxy resin manufacturing method) Next, a method for producing the epoxy resin of the present invention will be described in detail. The epoxy resin of the present invention can be produced by the Corey-Chaykovsky reaction of a sulfur ylide generated from trimethylsulfonium bromide, trimethylsulfonium iodide, trimethylsulfoxonium bromide, or trimethylsulfoxonium iodide with a polyfunctional aldehyde or ketone. This production method allows for the production of an epoxy resin that does not contain an -O-CH2- moiety derived from a glycidyl ether structure. Furthermore, since production by oxidation of an olefin using a peroxide is not required, safety during production is improved. The polyfunctional aldehyde or ketone is selected to have appropriate substituents and other groups at appropriate positions, taking into account the chemical formula of the desired epoxy resin. Examples of polyfunctional ketones that can be used as raw materials for the epoxy resin of the present invention are shown in the following formulas (24) to (29).

[0058] [ka]

[0059] In formulas (24) to (29), R 163 ~R 258are each independently a hydrogen atom, a halogen atom, a hydroxy group, an alkoxy group, an aralkyloxy group, an aryloxy group, a nitro group, an amino group, an amido group, a carboxy group, an alkyloxycarbonyl group, an aryloxycarbonyl group, a formyl group, a cyano group, an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group.

[0060] An example of a method for producing an epoxy resin of the present invention is described below. First, an organic solvent, water, and an alkali such as KOH are added to trimethylsulfonium bromide, trimethylsulfonium iodide, trimethylsulfoxonium bromide, or trimethylsulfoxonium iodide, and the mixture is stirred. A solution of the carbonyl compound (4,4'-bicyclohexanone) shown in the reaction formula (17) below dissolved in an organic solvent is then added, and the mixture is stirred again to allow the reaction to proceed. After the reaction, the mixture is cooled to room temperature, suction filtered, and separated. The organic layer is then washed, dried, filtered, concentrated, and dried under reduced pressure to obtain the epoxy resin (1,1'-dioxa-6,6'-bispyro[2.5]octane): DBO, which is the reaction product of formula (17).

[0061] [ka]

[0062] Another method for producing the epoxy resin of the present invention will now be described. First, the above-mentioned carbonyl compound is added to trimethylsulfonium bromide, trimethylsulfonium iodide, trimethylsulfoxonium bromide, or trimethylsulfoxonium iodide, and the reaction system is made into an inert atmosphere by argon substitution or the like. Then, an organic solvent such as dehydrated DMSO is added and stirred. Then, a solution of a base such as potassium tert-butoxide dissolved in an organic solvent is added and stirred, and the reaction proceeds according to the reaction formula shown in formula (17). After the reaction, the mixture is cooled to room temperature, suction filtered, and separated. The organic layer is then washed, dried, filtered, concentrated, and dried under reduced pressure to obtain the above-mentioned epoxy resin.

[0063] It is preferable to use 2 to 4 moles of trimethylsulfonium bromide, trimethylsulfonium iodide, trimethylsulfoxonium bromide, or trimethylsulfoxonium iodide per mole of the carbonyl compound. The reaction conditions may be appropriately determined, but for example, the reaction temperature is preferably 45 to 75°C, more preferably 55 to 65°C. The reaction time is preferably 2 to 7 hours, more preferably 3 to 4 hours. Examples of organic solvents that can be used include acetonitrile, dimethyl sulfoxide, and tetrahydrofuran.

[0064] The structure of the obtained epoxy resin can be confirmed by common organic analysis methods such as 1H-nuclear magnetic resonance (NMR) spectroscopy, 13C-NMR spectroscopy, 19F-NMR spectroscopy, infrared absorption (IR) spectroscopy using Fourier transform infrared spectroscopy (FT-IR) or the like, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

[0065] (Method of producing a cured epoxy resin product) Next, the method for producing the cured epoxy resin of the present invention will be described in detail. The cured epoxy resin of the present invention can be produced by curing the above-mentioned epoxy resin. To cure the epoxy resin, a commonly known curing accelerator such as the curing accelerator (2E4MZ-CN) represented by the following formula (18) can be used.

[0066] [ka]

[0067] The epoxy resin cured product of the present invention can be produced by curing an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) using a commonly known epoxy resin curing agent, as described above. Specifically, the epoxy resin can be produced by curing an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) with a curing agent represented by the formula (7) (phenol novolac: PN), a curing agent represented by the formula (8) (4,4'-diaminodiphenyl sulfone: DDS), or a curing agent represented by the formula (9) (m-phenylenediamine). Alternatively, the epoxy resin can be produced by curing with a curing agent represented by the formula (21). More specifically, an organic solvent such as acetone is first added to an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) and the mixture is stirred. Thereafter, the curing agent represented by the formula (7), (8), or (9) is added, and the mixture is stirred again to cause a reaction. After concentration and drying under reduced pressure, the mixture is cast and heat-cured to obtain a cured epoxy resin product.

[0068] The structure of the obtained cured epoxy resin product can be confirmed by infrared absorption (IR) spectroscopy using Fourier transform infrared spectroscopy (FT-IR) or the like, elemental analysis, X-ray scattering, or the like.

[0069] (Epoxy resin composition) The epoxy resin composition of the present invention contains an epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) and a curing agent. The epoxy resin cured product of the present invention can be produced by further mixing a curing accelerator with the epoxy resin composition and reacting them.

[0070] The curing agent contained in the epoxy resin composition of the present invention may be any of the curing agents that can be used to prepare the above-mentioned cured epoxy resin product of the present invention. Also, the curing accelerator that can be used in the curing reaction of the epoxy resin composition of the present invention may be any of the curing accelerators that can be used to prepare the above-mentioned cured epoxy resin product of the present invention.

[0071] The epoxy resin composition of the present invention may further contain an epoxy resin (other epoxy resin) other than the epoxy resin represented by any one of the formulas (1) to (6), (22), and (23), a filler, a fibrous substrate, a dispersion medium, a resin other than the various compounds described above, etc. Each of these components will be described in detail below.

[0072] <Other epoxy resins> The epoxy resin composition of the present invention may contain other epoxy resins in addition to the epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) as long as the effects of the present invention are not impaired. In this case, the proportion of the epoxy resin represented by any one of the formulas (1) to (6), (22), and (23) used in the epoxy resin composition of the present invention is preferably 30% by mass or more, and particularly preferably 40% by mass or more, of the total epoxy resins.

[0073] The epoxy resins that can be used in combination are not limited in any way, and examples thereof include liquid epoxy resins such as bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AD ​​type epoxy resins, resorcinol type epoxy resins, hydroquinone type epoxy resins, catechol type epoxy resins, dihydroxynaphthalene type epoxy resins, biphenyl type epoxy resins, and tetramethylbiphenyl type epoxy resins; brominated epoxy resins such as brominated phenol novolac type epoxy resins; solid bisphenol A type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, and triphenylmethane type epoxy resins. Examples of epoxy resins include epoxy resins, tetraphenylethane type epoxy resins, dicyclopentadiene-phenol addition reaction type epoxy resins, phenol aralkyl type epoxy resins, phenylene ether type epoxy resins, naphthylene ether type epoxy resins, naphthol novolac type epoxy resins, naphthol aralkyl type epoxy resins, naphthol-phenol co-condensed novolac type epoxy resins, naphthol-cresol co-condensed novolac type epoxy resins, aromatic hydrocarbon formaldehyde resin-modified phenolic resin-type epoxy resins, and biphenyl-modified novolac type epoxy resins. These may be used alone or in combination of two or more types, and it is preferable to select and use various types depending on the intended use, the physical properties of the cured product, etc.

[0074] The amounts of epoxy resin and curing agent in the epoxy resin composition of the present invention are not particularly limited, but in terms of good mechanical properties and the like of the resulting cured product, it is preferable that the amount of active groups in the curing agent be 0.7 to 1.5 equivalents per total equivalent of epoxy groups in the total amount of epoxy resin.

[0075] <Filler> The epoxy resin composition of the present invention may further contain a filler. Examples of the filler include inorganic fillers and organic fillers. Examples of the inorganic filler include inorganic fine particles.

[0076] Examples of inorganic fine particles with excellent heat resistance include alumina, magnesia, titania, zirconia, and silica (quartz, fumed silica, precipitated silica, silicic anhydride, fused silica, crystalline silica, and ultrafine amorphous silica). Examples of inorganic fine particles with excellent thermal conductivity include boron nitride, aluminum nitride, alumina oxide, titanium oxide, magnesium oxide, zinc oxide, silicon oxide, and diamond. Examples of inorganic fine particles with excellent electrical conductivity include metal fillers and / or metal-coated fillers using metals or alloys (e.g., iron, copper, magnesium, aluminum, gold, silver, platinum, zinc, manganese, and stainless steel). Examples of inorganic fine particles with excellent barrier properties include minerals such as mica, clay, kaolin, talc, zeolite, wollastonite, and smectite, as well as potassium titanate, magnesium sulfate, sepiolite, zonolite, aluminum borate, calcium carbonate, titanium oxide, barium sulfate, zinc oxide, and magnesium hydroxide. Examples of materials with a high refractive index include barium titanate, zirconia oxide, and titanium oxide. Examples of materials exhibiting photocatalytic properties include photocatalytic metals such as titanium, cerium, zinc, copper, aluminum, tin, indium, phosphorus, carbon, sulfur, thorium, nickel, iron, cobalt, silver, molybdenum, strontium, chromium, barium, and lead, as well as composites of these metals and oxides thereof. Examples of materials with excellent abrasion resistance include metals such as silica, alumina, zirconia, and magnesium oxide, as well as composites and oxides thereof. Examples of materials with excellent conductivity include metals such as silver and copper, tin oxide, and indium oxide. Examples of materials with excellent insulating properties include silica. Examples of materials with excellent UV blocking properties include titanium oxide and zinc oxide.

[0077] These inorganic fine particles may be selected appropriately depending on the application, and may be used alone or in combination of two or more kinds. In addition, the inorganic fine particles have various properties other than those exemplified, so they may be selected appropriately depending on the application.

[0078] For example, when silica is used as inorganic fine particles, known silica fine particles such as powdered silica or colloidal silica can be used without any particular limitation.As commercially available powdered silica fine particles, for example, Aerosil 50, 200 manufactured by Nippon Aerosil Co., Ltd., Sildex H31, H32, H51, H52, H121, H122 manufactured by Asahi Glass Co., Ltd., E220A, E220 manufactured by Nippon Silica Industrial Co., Ltd., SYLYSIA470 manufactured by Fuji Silysia Co., Ltd., SG Flake manufactured by Nippon Sheet Glass Co., Ltd., etc. can be mentioned.In addition, as commercially available colloidal silica, for example, methanol silica sol, IPA-ST, MEK-ST, NBA-ST, XBA-ST, DMAC-ST, ST-UP, ST-OUP, ST-20, ST-40, ST-C, ST-N, ST-O, ST-50, ST-OL manufactured by Nissan Chemical Industries, Ltd. can be mentioned.

[0079] Surface-modified silica fine particles may also be used, for example, the silica fine particles that have been surface-treated with a reactive silane coupling agent having a hydrophobic group, or modified with a compound having a (meth)acryloyl group. Examples of commercially available powdered silica modified with a compound having a (meth)acryloyl group include Aerosil RM50, R711, etc. manufactured by Nippon Aerosil Co., Ltd., and examples of commercially available colloidal silica modified with a compound having a (meth)acryloyl group include MIBK-SD, etc. manufactured by Nissan Chemical Industries, Ltd.

[0080] The shape of the silica fine particles is not particularly limited, and spherical, hollow, porous, rod-like, plate-like, fibrous, or amorphous shapes can be used. The primary particle diameter is preferably in the range of 5 to 200 nm. A diameter of 5 nm or more ensures sufficient dispersion of the inorganic fine particles in the dispersion, while a diameter of 200 nm or less facilitates maintaining sufficient strength of the cured product.

[0081] Titanium oxide microparticles can be used not only as extender pigments but also as ultraviolet light-responsive photocatalysts, such as anatase titanium oxide, rutile titanium oxide, and brookite titanium oxide. Furthermore, particles designed to respond to visible light by doping different elements into the crystalline structure of titanium oxide can also be used. Suitable elements for doping titanium oxide include anionic elements such as nitrogen, sulfur, carbon, fluorine, and phosphorus, and cationic elements such as chromium, iron, cobalt, and manganese. The titanium oxide can be used in the form of a powder, a sol dispersed in an organic solvent or water, or a slurry. Commercially available powdered titanium oxide microparticles include, for example, Aerosil P-25 manufactured by Nippon Aerosil Co., Ltd. and ATM-100 manufactured by Teika Co., Ltd. Commercially available slurry-type titanium oxide microparticles include, for example, TKD-701 manufactured by Teika Co., Ltd.

[0082] <Fibrous substrate> The epoxy resin composition of the present invention may further contain a fibrous substrate. The fibrous substrate is not particularly limited, but is preferably one used in fiber-reinforced resins, such as inorganic fibers and organic fibers.

[0083] Examples of inorganic fibers include inorganic fibers such as carbon fiber, glass fiber, boron fiber, alumina fiber, and silicon carbide fiber, as well as carbon fiber, activated carbon fiber, graphite fiber, glass fiber, tungsten carbide fiber, silicon carbide fiber (silicon carbide fiber), ceramic fiber, alumina fiber, natural fiber, mineral fiber such as basalt, boron fiber, boron nitride fiber, boron carbide fiber, and metal fiber. Examples of the metal fiber include aluminum fiber, copper fiber, brass fiber, stainless steel fiber, and steel fiber.

[0084] Examples of organic fibers include synthetic fibers made from resin materials such as polybenzazole, aramid, PBO (polyparaphenylene benzoxazole), polyphenylene sulfide, polyester, acrylic, polyamide, polyolefin, polyvinyl alcohol, and polyarylate; natural fibers such as cellulose, pulp, cotton, wool, and silk; and regenerated fibers such as protein, polypeptide, and alginic acid.

[0085] Among these, carbon fiber and glass fiber are preferred because they have a wide range of industrial applications. Of these, only one type may be used, or two or more types may be used simultaneously.

[0086] The fibrous substrate may be an assembly of fibers, with continuous or discontinuous fibers, in the form of a woven or nonwoven fabric, in the form of a fiber bundle in which the fibers are aligned in one direction, or in the form of a sheet in which fiber bundles are arranged, or in the form of a three-dimensional shape in which a thickness is added to an assembly of fibers.

[0087] <Dispersion medium> The epoxy resin composition of the present invention may contain a dispersion medium for the purpose of adjusting the solid content mass and viscosity of the composition. The dispersion medium may be any liquid medium that does not impair the effects of the present invention, and examples of the dispersion medium include various organic solvents and liquid organic polymers.

[0088] Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone (MEK), and methyl isobutyl ketone (MIBK); cyclic ethers such as tetrahydrofuran (THF) and dioxolane; esters such as methyl acetate, ethyl acetate, and butyl acetate; aromatics such as toluene and xylene; and alcohols such as carbitol, cellosolve, methanol, isopropanol, butanol, and propylene glycol monomethyl ether. These can be used alone or in combination, but methyl ethyl ketone is preferred from the standpoint of volatility during coating and solvent recovery.

[0089] The liquid organic polymer is a liquid organic polymer that does not directly contribute to the curing reaction, and examples thereof include modified carboxyl group-containing polymers (Floren G-900, NC-500: Kyoeisha), acrylic polymers (Floren WK-20: Kyoeisha), amine salts of special modified phosphate esters (HIPLAAD ED-251: Kusumoto Chemical), and modified acrylic block copolymers (DISPERBYK2000; BYK-Chemie).

[0090] <Resin> The epoxy resin composition of the present invention may contain a resin other than the various compounds described above. As the resin, any known and commonly used resin may be blended as long as it does not impair the effects of the present invention, and for example, a thermosetting resin or a thermoplastic resin may be used.

[0091] Thermosetting resins are resins that can become substantially insoluble and infusible when cured by heat, radiation, or catalysts. Examples include phenolic resins, urea resins, melamine resins, benzoguanamine resins, alkyd resins, unsaturated polyester resins, vinyl ester resins, diallyl terephthalate resins, silicone resins, urethane resins, furan resins, ketone resins, xylene resins, thermosetting polyimide resins, benzoxazine resins, active ester resins, aniline resins, cyanate ester resins, styrene-maleic anhydride (SMA) resins, and maleimide resins. These thermosetting resins can be used alone or in combination.

[0092] Thermoplastic resins refer to resins that can be melt-molded by heating. Specific examples include polyethylene resins, polypropylene resins, polystyrene resins, rubber-modified polystyrene resins, acrylonitrile-butadiene-styrene (ABS) resins, acrylonitrile-styrene (AS) resins, polymethyl methacrylate resins, acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polyethylene terephthalate resins, ethylene vinyl alcohol resins, cellulose acetate resins, ionomer resins, polyacrylonitrile resins, polyamide resins, polyacetal resins, polybutylene terephthalate resins, polylactic acid resins, polyphenylene ether resins, modified polyphenylene ether resins, polycarbonate resins, polysulfone resins, polyphenylene sulfide resins, polyetherimide resins, polyethersulfone resins, polyarylate resins, thermoplastic polyimide resins, polyamideimide resins, polyetheretherketone resins, polyketone resins, liquid crystal polyester resins, fluororesins, syndiotactic polystyrene resins, and cyclic polyolefin resins. These thermoplastic resins can be used alone or in combination of two or more.

[0093] (Uses of epoxy resin cured products and epoxy resin compositions) The epoxy resin cured product and epoxy resin composition of the present invention are excellent in both chemical heat resistance and physical heat resistance, and are useful for the following applications:

[0094] <Fiber reinforced resin> When the epoxy resin composition of the present invention has a fibrous substrate, and the fibrous substrate is a reinforcing fiber, the epoxy resin composition containing the fibrous substrate can be used as a fiber-reinforced resin. The method for incorporating the fibrous substrate into the composition is not particularly limited as long as the effects of the present invention are not impaired. Examples include methods for combining the fibrous substrate and the composition by methods such as kneading, coating, impregnation, injection, and pressure bonding, and the method can be selected appropriately depending on the form of the fiber and the application of the fiber-reinforced resin.

[0095] The method for molding the fiber-reinforced resin of the present invention is not particularly limited. To produce a plate-shaped product, extrusion molding is commonly used, but flat presses are also possible. Other methods that can be used include extrusion molding, blow molding, compression molding, vacuum molding, and injection molding. To produce a film-shaped product, melt extrusion and solution casting can be used. Examples of melt molding methods include inflation film molding, cast molding, extrusion lamination molding, calendar molding, sheet molding, fiber molding, blow molding, injection molding, rotational molding, and coating molding. For resins that are cured with active energy rays, cured products can be produced using various curing methods using active energy rays. In particular, when a thermosetting resin is used as the main component of the matrix resin, examples of molding methods include prepreg molding of the molding material and pressurizing and heating it using a press or autoclave. Other examples include RTM (Resin Transfer Molding) molding, Vacuum-assisted Resin Transfer Molding (VaRTM) molding, laminate molding, and hand layup molding.

[0096] <Prepreg> The fiber-reinforced resin of the present invention can be formed into a state called an uncured or semi-cured prepreg. After distributing the product in the prepreg state, final curing may be performed to form a cured product. When forming a laminate, it is preferable to form the prepreg, then laminate other layers, and then perform final curing, since this allows the formation of a laminate in which each layer is in close contact. The mass ratio of the composition and fibrous substrate used here is not particularly limited, but it is usually preferable to prepare the prepreg so that the resin content is 20 to 60 mass %.

[0097] <Heat-resistant materials and electronic materials> The epoxy resin composition of the present invention provides cured epoxy resin products having excellent chemical and physical heat resistance, making it suitable for use as heat-resistant materials and electronic materials. It is particularly suitable for semiconductor encapsulation, circuit boards, build-up films, build-up boards, adhesives, and resist materials. It is also suitable for use as a matrix resin for fiber-reinforced resins, and is particularly suitable as a highly heat-resistant prepreg. The heat-resistant and electronic components thus obtained are suitable for a variety of applications, including, but not limited to, industrial machine parts, general machine parts, automobile, railway, and vehicle parts, aerospace and aviation-related parts, electronic and electrical components, building materials, containers and packaging materials, household goods, sports and leisure goods, and housing components for wind power generation.

[0098] Below, we will explain some representative products by giving examples. 1.Semiconductor encapsulation materials A method for obtaining a semiconductor encapsulating material from the epoxy resin composition of the present invention includes thoroughly melt-mixing the composition, a curing accelerator, and compounding ingredients such as an inorganic filler, using an extruder, kneader, roll, or the like, as needed, until the mixture is homogeneous. In this process, fused silica is typically used as the inorganic filler. However, when used as a high-thermal-conductivity semiconductor encapsulating material for power transistors and power ICs, highly filled materials such as crystalline silica, alumina, and silicon nitride, which have higher thermal conductivity than fused silica, or fused silica, crystalline silica, alumina, and silicon nitride may be used. The inorganic filler is preferably used in an amount of 30 to 95% by mass per 100 parts by mass of the epoxy resin composition. In particular, a filler content of 70 parts by mass or more is more preferred, and 80 parts by mass or more is even more preferred, in order to improve flame retardancy, moisture resistance, and solder crack resistance and to reduce the linear expansion coefficient.

[0099] 2. Semiconductor Devices The semiconductor package molding method for obtaining a semiconductor device from the epoxy resin composition of the present invention includes molding the semiconductor encapsulating material using a casting machine, a transfer molding machine, an injection molding machine or the like, and then heating the molded product at 50 to 250°C for 2 to 10 hours.

[0100] 3. Printed wiring board A method for obtaining a printed wiring board from the epoxy resin composition of the present invention includes laminating the above prepreg by a conventional method, appropriately overlaying copper foil, and heat-pressing the laminate under a pressure of 1 to 10 MPa at 170 to 300°C for 10 minutes to 3 hours.

[0101] 4. Build-up board A method for obtaining a build-up substrate from the epoxy resin composition of the present invention includes, for example, the following steps. First, the composition, which contains an appropriate blend of rubber, filler, and the like, is applied to a circuit board on which a circuit has been formed using a spray coating method, curtain coating method, or the like, and then cured (Step 1). Subsequently, if necessary, predetermined through-holes or the like are drilled, the surface is treated with a roughening agent, and the surface is washed with hot water to form a roughened surface, followed by plating with a metal such as copper (Step 2). These operations are sequentially repeated as desired to alternately build up resin insulating layers and conductor layers of a predetermined circuit pattern (Step 3). Note that drilling of through-holes is performed after the formation of the outermost resin insulating layer. Alternatively, the build-up substrate of the present invention can be produced by forming a roughened surface by heat-pressing a copper foil, in which the resin composition has been semi-cured on a copper foil, onto a wiring board on which a circuit has been formed, at 170 to 300°C, thereby eliminating the steps of forming a roughened surface and plating.

[0102] 5. Build-up film A build-up film can be obtained from the epoxy resin composition of the present invention by applying the composition to the surface of a support film (Y) as a substrate, and then drying the organic solvent by heating or blowing hot air or the like to form a layer of the composition (X).

[0103] The organic solvent used here is preferably, for example, a ketone such as acetone, methyl ethyl ketone, or cyclohexanone; an acetate ester such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, or carbitol acetate; a carbitol such as cellosolve or butyl carbitol; an aromatic hydrocarbon such as toluene or xylene; dimethylformamide, dimethylacetamide, or N-methylpyrrolidone; and it is preferably used in a proportion such that the nonvolatile content is 30 to 60% by mass.

[0104] The thickness of the layer (X) formed is usually equal to or greater than the thickness of the conductor layer. Since the thickness of the conductor layer of a circuit board is usually in the range of 5 to 70 μm, the thickness of the resin composition layer is preferably 10 to 100 μm. In addition, the layer (X) of the composition in the present invention may be protected with a protective film described below. Protection with a protective film can prevent adhesion of dust and the like to the surface of the resin composition layer and scratches.

[0105] Examples of the support film and protective film include polyolefins such as polyethylene, polypropylene, and polyvinyl chloride; polyesters such as polyethylene terephthalate (hereinafter sometimes abbreviated as "PET") and polyethylene naphthalate; polycarbonate; polyimide; and even release paper and metal foils such as copper foil and aluminum foil. The support film and protective film may be subjected to a mud treatment, a corona treatment, or a release treatment. The thickness of the support film is not particularly limited, but is usually 10 to 150 μm, and preferably 25 to 50 μm. The thickness of the protective film is preferably 1 to 40 μm.

[0106] The support film (Y) is peeled off after laminating it onto a circuit board or after forming an insulating layer by heat curing. If the support film (Y) is peeled off after the curable resin composition layer constituting the build-up film is heat cured, adhesion of dust and the like during the curing process can be prevented. When peeling off after curing, the support film is usually subjected to a release treatment in advance.

[0107] A multilayer printed circuit board can be produced using the build-up film obtained as described above. For example, if the layer (X) is protected by a protective film, the film is peeled off, and then the layer (X) is laminated to one or both sides of the circuit board so as to be in direct contact with the circuit board, for example, by a vacuum lamination method. The lamination method may be a batch method or a continuous method using a roll. If necessary, the build-up film and the circuit board may be heated (preheated) before lamination. The lamination conditions are preferably a pressure bonding temperature (lamination temperature) of 70 to 140°C and a pressure bonding pressure of 1 to 11 kgf / cm. 2 (9.8×10 4 ~107.9×10 4 N / m 2 ), and lamination is preferably carried out under reduced air pressure of 20 mmHg (26.7 hPa) or less.

[0108] 6.Conductive paste A conductive paste can be obtained from the epoxy resin composition of the present invention by dispersing conductive particles in the composition. Depending on the type of conductive particles used, the conductive paste can be a paste resin composition for circuit connection or an anisotropic conductive adhesive. [Example]

[0109] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0110] (Epoxy resin manufacturing) [Example 1] A 300 mL three-neck flask was charged with 23.56 g (0.15 mol) of trimethylsulfonium bromide, 150 mL of acetonitrile, 0.45 mL (0.025 mol) of water, and 33.67 g (0.60 mol) of potassium hydroxide. The mixture was stirred at 60°C for 15 min. Then, a solution of 9.71 g (0.050 mol) of 4,4'-bicyclohexanone (Tokyo Chemical Industry Co., Ltd.) dissolved in 70 mL of acetonitrile was slowly added dropwise to the recovery flask and stirred again at 60°C for 3 h. After the reaction was complete, the mixture was cooled to room temperature, suction filtered (rinsing with methylene chloride), and concentrated in an evaporator. This was followed by three phases of separation (methylene chloride / pure water). The organic layer was then washed with saturated brine, dried over anhydrous sodium sulfate, filtered, concentrated, and dried under reduced pressure (rt / ovn) to yield 10.61 g of a pale yellow-white solid. Next, the obtained pale yellowish white solid was purified by silica gel column chromatography (developing solvent: ethyl acetate / hexane = 1 / 2 (volume ratio)), and R f The component with a pH of 0.50 was collected. The resulting solution was concentrated using an evaporator and then dried under reduced pressure (40°C / 16 hours) to obtain 10.12 g of a white solid (yield 91%). 1 H-NMR spectrum analysis and 13 C-NMR spectrum analysis and FT-IR spectrum analysis (KBr) confirmed that the epoxy resin (DBO) represented by formula (19) was obtained.

[0111] [ka]

[0112] (Curing of epoxy resins with polyfunctional amine curing agents) [Example 2] A 50 mL recovery flask was charged with 1.9002 g (EEW ​​= 111.17 g / eq.) of the epoxy resin (DBO) obtained in Example 1, 0.5299 g (active hydrogen equivalent = 31.0 g / eq.) of the curing agent (MPDA) represented by the following formula (9), and acetone, followed by stirring (rt / 40 min). After confirming complete dissolution, the mixture was concentrated by evaporation and dried under reduced pressure (rt / ovn) to obtain a colorless, transparent liquid (mixture). The colorless, transparent liquid was then melted at 70°C and poured into a silicone casting mold. The mixture was then degassed (70°C / 15 min) and heat-cured in the following order: 70°C for 1 hour, 90°C for 1 hour, 140°C for 1 hour, 180°C for 3 hours, 210°C for 4 hours, and 240°C for 4 hours, to obtain a polyfunctional amine-cured epoxy resin cured product (brown, transparent cured product) according to Example 2.

[0113] [ka]

[0114] [Comparative Example 1] A 50 mL recovery flask was charged with 1.5392 g (EEW ​​= 155.2 g / eq.) of epoxy resin (4,4'-bis(oxiran-2-ylmethoxy)-1,1'-bi(cyclohexane):BGOBH) represented by the following formula (20), 0.3074 g (active hydrogen equivalent = 31.0 g / eq.) of curing agent (MPDA) represented by the above formula (9), and acetone, followed by stirring (rt / 40 min). After confirming complete dissolution, the mixture was evaporated and dried under reduced pressure (rt / ovn) to obtain a transparent orange liquid (mixture). The orange liquid was then melted at 70 °C and poured into a silicone casting mold. Subsequently, after degassing (70°C / 30 minutes), the mixture was subjected to heat curing treatments at 70°C for 1 hour, 90°C for 1 hour, 130°C for 3 hours, 170°C for 3 hours, 200°C for 3 hours, and 230°C for 3 hours in this order, thereby obtaining a polyfunctional amine-cured epoxy resin cured product according to Comparative Example 1.

[0115] [ka]

[0116] (Evaluation of Polyfunctional Amine-Cured Epoxy Resin Cured Products) The polyfunctional amine-cured epoxy resin cured products obtained in Example 2 and Comparative Example 1 were subjected to FT-IR spectrum analysis (KBr), and it was confirmed that the absorption at the same position as the absorption of the epoxy group of the epoxy resin had disappeared. Furthermore, thermogravimetric analysis (TGA measurement) was carried out on each of the cured epoxy resin products using a TGA-50 manufactured by Shimadzu Corporation. The heating rate was set to 10°C / min, and the measurement was carried out in a N2 gas atmosphere. The temperature at which 5% of the weight was lost from the initial weight (5% weight loss temperature: T d5 ), the temperature at which the weight has decreased by 10% from the initial value (10% weight loss temperature: T d10 ) was measured. In addition, the glass transition temperature (Tg) of the cured epoxy resin product was measured by dynamic viscoelasticity measurement (DMA measurement) using a DMS6100 manufactured by SII Nano Technology Inc. The measurement was performed at a heating rate of 5°C / min and a frequency of 1.0 Hz. The measurement results are shown in Table 1, Figures 1 and 2. Figure 1 is a graph showing the TGA measurement results for Example 2 and Comparative Example 1. Figure 2 is a graph showing the DMA measurement results for Example 2 and Comparative Example 1. Furthermore, test pieces measuring 40 mm in length, 10 mm in width, and 2.0 mm in thickness were prepared from the cured epoxy resin product of Example 2, and a three-point bending test was performed using a Shimadzu AG-X 10 kN universal testing machine at a test speed of 2.0 mm / min and a support distance of 28 mm to determine the flexural modulus and flexural strength. The measurement results are shown in Table 1.

[0117] [Table 1]

[0118] Table 1 and Figures 1 and 2 show that the cured epoxy resin material of Example 2 (the product of the present invention) is superior to the cured epoxy resin material of Comparative Example 1 (the conventional product) in both chemical heat resistance and physical heat resistance.

[0119] (Curing of epoxy resin with active ester type curing agent) [Example 3] According to the equivalent blending ratio shown in Table 2 below, the epoxy resin (DBO) represented by the formula (19) above and an active ester-type curing agent containing a dicyclopentadienyldiphenol structure (the solid component of "EPICLON HPC-8000L-75™" manufactured by DIC Corporation (hereinafter referred to as EPICLON HPC-8000L), active equivalent: 220 g / eq) were melt-blended at 150°C, and dimethylaminopyridine was further added as a curing catalyst to prepare a liquid sample (mixture). Next, the liquid sample was poured into a mold and cured by heat curing treatment at 180°C for 2 hours, 200°C for 2 hours, and 230°C for 2 hours in that order, and molded into a plate-shaped test piece (cured epoxy resin) with a thickness of 2 mm. Next, the test piece was stored in a room at 23°C and 50% humidity for 24 hours, and then the dielectric loss tangent of the test piece at 1 GHz was measured in accordance with JIS-C-2138 using an open coaxial resonance type dielectric constant measuring device "ADMS01Oc1" manufactured by AET Corporation.

[0120] Comparative Example 2 An epoxy resin cured product was prepared using an active ester curing agent in the same manner as in Example 3, except that the epoxy resin was the epoxy resin (BGOBH) represented by the formula (20) above, and the dielectric loss tangent was measured. The evaluation results are shown in Table 2.

[0121] [Table 2]

[0122] The results in Table 2 show that the cured epoxy resin material of Example 3 (the present invention) has a dielectric loss tangent that is approximately 30% better than that of the cured epoxy resin material of Comparative Example 2 (a conventional product). Therefore, circuit boards using the cured epoxy resin material of Example 3 are expected to enable high-speed operation of high-frequency devices.

Claims

1. An epoxy resin represented by any one of the following formulas (1) to (6): 【Chemical 1】 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】 【Chemistry 6】

2. A cured epoxy resin product obtained by curing the epoxy resin represented by any one of formulas (1) to (6) according to claim 1.

3. 3. The epoxy resin cured product according to claim 2, obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) with a curing agent represented by the following formula (7): 【Chemistry 7】 (In formula (7), n is a positive integer.)

4. 3. The epoxy resin cured product according to claim 2, obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) with a curing agent represented by the following formula (8): 【Chemistry 8】

5. 3. The epoxy resin cured product according to claim 2, obtained by curing an epoxy resin represented by any one of the formulas (1) to (6) with a curing agent represented by the following formula (9): 【Chemistry 9】

6. A method for producing a cured epoxy resin by curing the epoxy resin represented by any one of formulas (1) to (6) according to claim 1.

7. The method for producing a cured epoxy resin product according to claim 6, wherein the epoxy resin represented by any one of the formulas (1) to (6) is cured with a curing agent represented by the following formula (7): 【Chemistry 10】 (In formula (7), n is a positive integer.)

8. The method for producing a cured epoxy resin product according to claim 6, wherein the epoxy resin represented by any one of the formulas (1) to (6) is cured with a curing agent represented by the following formula (8): 【Chemistry 11】

9. The method for producing a cured epoxy resin product according to claim 6, wherein the epoxy resin represented by any one of the formulas (1) to (6) is cured with a curing agent represented by the following formula (9): 【Chemistry 12】

10. An epoxy resin represented by any one of formulas (1) to (6) according to claim 1; A hardener; 1. An epoxy resin composition comprising:

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