Polyhydroxy resin, epoxy resin, methods for producing them, epoxy resin composition using them, and cured product

Abstract

To provide: a polyhydric hydroxy resin which can form a cured product excellent in heat resistance, moisture resistance, low dielectricity, high thermal conductivity and the like, and is useful in applications such as lamination, molding, casting and bonding; and an epoxy resin thereof.SOLUTION: The polyhydric hydroxy resin is represented by the general formula (1) in the figure, where A represents a divalent aromatic group and n represents a number from 1 to 50. The epoxy resin is obtained by reacting the polyhydric hydroxy resin with epichlorohydrin.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin that provides a cured product that is excellent in heat resistance, moisture resistance, and low dielectric properties as well as high thermal conductivity, and also relates to an intermediate thereof, a curing agent, an epoxy resin composition using the same, and a cured product thereof, which are suitable for use as insulating materials in the electrical and electronic fields, such as printed wiring boards and semiconductor encapsulation. [Background technology]

[0002] In recent years, advances in advanced materials have led to a demand for the development of higher-performance base resins. For example, in the field of semiconductor encapsulation, the trend toward thinner, larger-area packages for higher-density packaging, coupled with the widespread adoption of surface-mounting methods, has exacerbated the problem of package cracking. This has led to a strong demand for base resins with improved moisture resistance, heat resistance, and adhesion to metal substrates. Recently, materials with high thermal decomposition stability and thermal conductivity are required to improve heat resistance and heat dissipation, particularly in the power device field. Furthermore, materials with excellent dielectric properties are also required for high-speed communications.

[0003] However, none of the conventionally known epoxy resins has yet satisfied these requirements. For example, well-known bisphenol-type epoxy resins are widely used because they are liquid at room temperature, have excellent workability, and are easily mixed with curing agents, additives, etc., but have problems with heat resistance and moisture resistance. Phenol novolac-type epoxy resins are known to have improved heat resistance, but have problems with moisture resistance and impact resistance. Patent Document 1 also proposes an epoxy compound of a phenol aralkyl resin with the aim of improving moisture resistance and impact resistance, but the compound is insufficient in terms of heat resistance and flame retardancy.

[0004] Patent Document 2 proposes the application of an aralkyl epoxy resin having a biphenyl structure to a semiconductor encapsulation material, but the heat resistance is insufficient. Patent Documents 3, 4, and 5 propose liquid crystalline epoxy resins having rigid mesogen groups and epoxy resin compositions using the same, but they have problems with moldability and do not achieve a sufficient effect of improving thermal conductivity.

[0005] Patent Document 6 discloses various epoxy resins containing fluorine atoms, but none of them are sufficient for use as electrical insulating materials in terms of heat resistance, thermal conductivity, etc. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 63-238122 [Patent Document 2] Japanese Patent Application Publication No. 11-140166 [Patent Document 3] Japanese Patent Application Publication No. 11-323162 [Patent Document 4] Japanese Patent Application Laid-Open No. 2004-331811 [Patent Document 5] Japanese Patent Application Publication No. 9-118673 [Patent Document 6] Japanese Patent Application Laid-Open No. 2003-321409 Summary of the Invention [Problem to be solved by the invention]

[0007] Accordingly, an object of the present invention is to provide a polyhydric hydroxy resin and an epoxy resin thereof which have excellent moldability and can give a cured product which is excellent in heat resistance, moisture resistance, low dielectric properties, high thermal conductivity, etc., and which are useful for applications such as lamination, molding, casting, and adhesion, as well as methods for producing them, epoxy resin compositions using them, and cured products thereof. [Means for solving the problem]

[0008] That is, the present invention relates to a novel polyhydroxy resin represented by the following general formula (1). [ka] (wherein A represents a divalent aromatic group, and n represents a number from 1 to 50.)

[0009] The present invention also provides a compound represented by the following general formula (3): [ka] (wherein each Y independently represents a halogen atom.) The method for producing the polyvalent hydroxy resin of the above general formula (1) is characterized by reacting 0.1 to 0.9 moles of a trifluoromethylbenzene compound represented by the following formula (1):

[0010] Furthermore, the present invention provides a compound represented by the following general formula (4): [ka] (wherein, A independently represents a divalent aromatic group, G represents a glycidyl group, and n represents a number from 1 to 50.) The epoxy resin is characterized by being represented by the formula:

[0011] Furthermore, the present invention is a method for producing a novel epoxy resin represented by the above general formula (4), which comprises reacting a polyhydric hydroxy resin represented by the above general formula (1) with epichlorohydrin.

[0012] Furthermore, the present invention relates to an epoxy resin composition containing at least one of the above-mentioned epoxy resin and polyhydroxy resin as an essential component of the epoxy resin component or curing agent component, and also to a cured product obtained by curing this epoxy resin composition. [Effects of the Invention]

[0013] The cured product obtained by curing the epoxy resin composition obtained from the epoxy resin or polyhydroxy resin of the present invention has excellent heat resistance, low dielectric properties and moisture resistance, and can be suitably used in applications such as lamination, molding, casting and adhesion. [Brief explanation of the drawings]

[0014] [Figure 1] 1 shows a GPC chart of polyhydroxy resin A obtained in Example 1. [Figure 2] 1 shows an IR spectrum of polyhydroxy resin A obtained in Example 1. [Figure 3] 1 shows a GPC chart of polyhydroxy resin B obtained in Example 2. [Figure 4] 1 shows a GPC chart of epoxy resin A obtained in Example 4. [Figure 5] 1 shows an IR spectrum of epoxy resin A obtained in Example 4. DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention will be described in detail below. The polyhydric hydroxy resin of the present invention is represented by general formula (1). [ka] Here, A independently represents a divalent aromatic group. The divalent aromatic group is a benzene ring, a naphthalene ring, or a ring represented by the following formula (2): [ka] Examples of the bisphenylene group include bisphenylene groups represented by the following formula: Here, X represents a single bond, an oxygen atom, a sulfur atom, -SO2-, -CO-, -CH2-, -CH(CH3)-, -C(CH3)2-, -CH(φ)-, -Cφ(CH3)-, a 1,1-cycloalkane group, or a 9,9-fluorenyl group. Here, φ represents a phenylene group. R1 to R4 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an aryl group, an alkoxy group, an aralkyl group, or a halogen atom. Preferably, R1 to R4 are a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an aralkyl group having 7 to 9 carbon atoms.

[0016] The polyhydroxy resin of the present invention may be a single compound or a mixture of compounds satisfying formula (1). n represents the number of repeating units and is 1 to 50, preferably 1 to 15. In the case of a mixture having a molecular weight distribution, the average value of n (Σn / Σ number of molecules) is preferably 0.1 to 10.0, more preferably 0.5 to 5.0.

[0017] The polyhydric hydroxy resin of the present invention has a hydroxyl group equivalent of preferably 150 to 3000 g / eq., more preferably 180 to 1000 g / eq., and even more preferably 200 to 500 g / eq. The softening point or melting point is preferably 35 to 300°C.

[0018] The polyhydric hydroxy resin of the present invention preferably has a molecular weight distribution such that, in formula (1), n=0 units account for 5 to 50%, n=1 units for 10 to 40%, n=2 units for 10 to 30%, and the remainder are n=3 or more units.

[0019] The polyhydric hydroxy resin of the present invention can be obtained by reacting an aromatic dihydroxy compound with a trifluoromethylbenzene compound represented by general formula (3). [ka] Here, Y independently represents a halogen atom.

[0020] The aromatic dihydroxy compound is a divalent dihydroxybenzene or dihydroxynaphthalene substituted or unsubstituted with an alkyl group having 1 to 6 carbon atoms, or a compound represented by the following formula (5): [ka] In formula (5), X and R1 to R4 have the same meanings as in general formula (2). Specific examples of dihydroxybenzenes include hydroquinone, 2,5-dimethylhydroquinone, 2,3,5-trimethylhydroquinone, resorcinol, and catechol, and examples of dihydroxynaphthalenes include 1,4-naphthalenediol, 1,5-naphthalenediol, 1,6-naphthalenediol, 1,7-naphthalenediol, 2,6-naphthalenediol, and 2,7-naphthalenediol. Examples of bisphenol compounds include bisphenol A, bisphenol F, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxybiphenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxybenzophenone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 1,1-bis(4-hydroxyphenyl)cyclohexane, and 9,9-bis(4-hydroxyphenyl)fluorene.

[0021] Regarding the substitution position of the dihydroxy group, the dihydroxybenzenes are preferably 1,4-dihydroxy or 1,3-dihydroxy, the dihydroxynaphthalenes are preferably 1,5-dihydroxy, 1,6-dihydroxy, 2,6-dihydroxy, or 2,7-dihydroxy, and the bisphenol compounds are preferably 4,4'-dihydroxy. In the aromatic dihydroxy compound used, these dihydroxy substitutions are preferably 50 mol % or more.

[0022] Among these aromatic dihydroxy compounds, dihydroxybenzenes, dihydroxynaphthalenes, and dihydroxybiphenyls are preferred from the viewpoints of heat resistance, thermal conductivity, mechanical strength, etc. The above aromatic dihydroxy compounds may be used alone or in combination of two or more.

[0023] In the trifluoromethylbenzene compound of general formula (3), Y is a halogen atom, exemplified by a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom or a chlorine atom being preferred. Furthermore, the substitution position of the halogen atom is preferably the 2,4-position, the 2,5-position, the 2,6-position, or the 3,5-position. Specific examples include 1-trifluoromethyl-2,4-difluorobenzene, 1-trifluoromethyl-2,5-difluorobenzene, 1-trifluoromethyl-2,6-difluorobenzene, 1-trifluoromethyl-2,4-dichlorobenzene, 1-trifluoromethyl-2,5-dichlorobenzene, and 1-trifluoromethyl-2,6-dichlorobenzene.

[0024] In the reaction between an aromatic dihydroxy compound and a trifluoromethylbenzene compound, an excess amount of the aromatic dihydroxy compound relative to the trifluoromethylbenzene compound is used. The amount of trifluoromethylbenzene compound used is in the range of 0.1 to 0.9 mol, preferably 0.1 to 0.6 mol, per mol of the aromatic dihydroxy compound. A higher amount increases the softening point of the resin, hindering molding workability. Furthermore, gelation may occur. A lower amount results in a large amount of excess aromatic dihydroxy compound remaining after the reaction is complete. The remaining excess aromatic dihydroxy compound can be used as a raw material or curing agent for epoxy resins without removal. However, the content of the resin of general formula (1) or (4) is reduced, which reduces the effect of improving properties such as low dielectric constant, thermal conductivity, heat resistance, and low water absorption when the cured product is obtained.

[0025] This reaction is preferably carried out in the presence of a basic catalyst, and at least one compound selected from the group consisting of tertiary amine compounds, quaternary ammonium compounds, imidazole compounds, tertiary phosphine compounds, quaternary phosphonium compounds, alkali metal hydroxide compounds, alkaline earth metal hydroxide compounds, alkali metal carbonates, and alkali metal hydrogencarbonates can be used.

[0026] These basic catalysts may be used alone or may be dissolved in water or a solvent beforehand and then added to the reaction system. The proportion of the basic catalyst used is usually 0.001 to 10 mol %, preferably 0.05 to 5 mol %, per mol of the phenolic hydroxyl group of the aromatic dihydroxy compound.

[0027] This reaction is usually carried out for 1 to 20 hours at 10 to 250° C. Furthermore, as a reaction solvent, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, and ethyl cellosolve, as well as benzene, toluene, chlorobenzene, and dichlorobenzene can be used.

[0028] After the reaction is completed, the catalyst is removed, if necessary, by neutralization, washing with water, etc., and the remaining solvent is removed from the system, if necessary, by washing with water, distillation under reduced pressure, etc., to obtain a hydroxy resin. The unreacted aromatic dihydroxy compound may or may not be removed from the system by washing with water, distillation under reduced pressure, etc.

[0029] The epoxy resin of the present invention is represented by general formula (4). [ka] Here, G represents a glycidyl group, and A and n have the same meanings as in the general formula (1).

[0030] The epoxy resin of the present invention represented by general formula (4) has a glycidyl group instead of the phenolic hydroxyl group of the polyhydric hydroxy resin represented by general formula (1), and the molecular weight distribution of the polyhydric hydroxy resin is almost the same as that of the polyhydric hydroxy resin. The epoxy resin of the present invention has an epoxy equivalent of preferably 180 to 3000 g / eq., more preferably 200 to 1500 g / eq., and even more preferably 220 to 1000 g / eq. The softening point or melting point is preferably 50 to 300° C., more preferably 80 to 200° C. The content of hydrolyzable chlorine is 1000 ppm or less.

[0031] The epoxy resin of the present invention can be obtained by reacting the polyhydric hydroxy resin represented by the above general formula (1) with epichlorohydrin. This reaction can be carried out in the same manner as a conventional epoxidation reaction.

[0032] For example, a method can be used in which the polyhydric hydroxy resin represented by the general formula (1) is dissolved in excess epichlorohydrin and then reacted in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide at 50 to 150°C, preferably 60 to 120°C, for 1 to 10 hours. The alkali metal hydroxide is used in an amount of 0.8 to 2 moles, preferably 0.9 to 1.2 moles, per mole of hydroxyl groups in the polyhydric hydroxy resin. Epichlorohydrin is used in excess relative to the hydroxyl groups in the polyhydric hydroxy resin, typically in an amount of 1.5 to 15 moles, preferably 2 to 8 moles, per mole of hydroxyl groups in the polyhydric hydroxy resin. A quaternary ammonium salt or the like can be added during the reaction. Examples of quaternary ammonium salts include tetramethylammonium chloride, tetrabutylammonium chloride, and benzyltriethylammonium chloride. The amount of the quaternary ammonium salt added is preferably 0.1 to 2.0 wt% of the polyhydric hydroxy resin. If the amount is less than this, the effect of adding the quaternary ammonium salt is small, and if it is more than this, the generation of difficult-to-hydrolyze chlorine increases, making it difficult to achieve high purity. Furthermore, polar solvents such as dimethyl sulfoxide and diglyme may be used, and the amount added is preferably in the range of 10 to 200 wt% relative to the polyhydroxy resin. If the amount is less than this, the effect of adding is small, and if it is more than this, the volume efficiency decreases, which is not economically preferable. After completion of the reaction, the excess epichlorohydrin is distilled off, and the residue is dissolved in a solvent such as toluene or methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the solvent is distilled off to obtain the desired epoxy resin. The epoxy resin of the present invention contains as a main component a compound represented by general formula (4), but may also contain a compound in which the epoxy groups in the epoxy resin are oligomerized as ether bonds.

[0033] The epoxy resin composition of the present invention comprises an epoxy resin and a curing agent, and contains, as an essential component, at least one of an epoxy resin represented by general formula (4) as an epoxy resin component and a polyhydroxy resin represented by general formula (1) as a curing agent component. An epoxy resin represented by general formula (4) may be blended as the epoxy resin component, and a polyhydroxy resin represented by general formula (1) may be blended as the curing agent component.

[0034] When the epoxy resin represented by general formula (4) is used as an essential component, any curing agent generally known as an epoxy resin curing agent can be used. Examples include dicyandiamide, polyhydric phenols, acid anhydrides, aromatic and aliphatic amines, etc. Specific examples of polyhydric phenols include dihydric phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, and naphthalenediol; trihydric or higher phenols such as tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol novolac, o-cresol novolac, naphthol novolac, and polyvinylphenol; and further, phenols, naphthols, bisphenol A, bisphenol B, and the like. Examples of suitable phenolic compounds include polyhydric phenolic compounds synthesized by condensing dihydric phenols such as phenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, and naphthalenediol with condensing agents such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, and p-xylylene glycol. Examples of suitable acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl ... Examples of amines include aromatic amines such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylsulfone, m-phenylenediamine, and p-xylylenediamine, and aliphatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine. Alternatively, a polyhydric hydroxyl resin represented by general formula (1) may be used. The resin composition of the present invention can use one or a mixture of two or more of these curing agents. In this case, the blending amount of the epoxy resin of the present invention is preferably in the range of 5 to 100 wt %, more preferably in the range of 50 to 100 wt %, and even more preferably in the range of 80 to 100 wt % of the total epoxy resin.

[0035] When the polyhydric hydroxy resin represented by general formula (1) is used as an essential component of the curing agent, any conventional epoxy resin having two or more epoxy groups in the molecule can be used as the epoxy resin. Examples include dihydric phenols such as bisphenol A, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, and resorcinol; trihydric or higher phenols such as tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol novolac, and o-cresol novolac; and glycidyl ethers derived from halogenated bisphenols such as tetrabromobisphenol A. Alternatively, a multifunctional epoxy resin represented by general formula (1) can be used. These epoxy resins can be used alone or in combination. In this case, the blending amount of the polyhydric hydroxy resin of the present invention is preferably in the range of 5 to 100 wt %, more preferably in the range of 50 to 100 wt %, and even more preferably in the range of 70 to 100 wt % of the total curing agent.

[0036] The blending ratio of epoxy resin to curing agent is preferably in the range of 0.8 to 1.5 in terms of equivalent ratio of epoxy groups to functional groups in the curing agent. Outside this range, there is a possibility that unreacted epoxy groups or functional groups in the curing agent may remain after curing.

[0037] The epoxy resin composition of the present invention, which contains either or both of the epoxy resin represented by general formula (4) and the polyhydroxy resin represented by general formula (1), may contain, as an essential component, oligomeric or polymeric compounds such as polyesters, polyamides, polyimides, polyethers, polyurethanes, petroleum resins, indene coumarone resins, and phenoxy resins. It may also contain additives such as inorganic fillers, pigments, flame retardants, thixotropic agents, coupling agents, and flowability improvers. Examples of inorganic fillers include silica powders such as spherical or crushed fused silica and crystalline silica, alumina powders, glass powders, mica, talc, calcium carbonate, alumina, and hydrated alumina. Examples of pigments include organic or inorganic extender pigments and scaly pigments. Examples of thixotropic agents include silicone-based agents, castor oil-based agents, aliphatic amide waxes, oxidized polyethylene waxes, and organic bentonite-based agents. Furthermore, conventionally known curing accelerators may be used as needed. Examples include amines, imidazoles, organic phosphines, Lewis acids, etc. The amount added is usually in the range of 0.2 to 5 parts by weight per 100 parts by weight of the epoxy resin. Furthermore, if necessary, the resin composition of the present invention may further contain a mold release agent such as carnauba wax or OP wax, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a colorant such as carbon black, a flame retardant such as antimony trioxide, a stress reducer such as silicone oil, a lubricant such as calcium stearate, etc.

[0038] The cured product of the present invention can be obtained by molding the above-mentioned epoxy resin composition by a method such as casting, compression molding, transfer molding, etc. The temperature during molding is usually in the range of 120 to 220°C. [Example]

[0039] The present invention will be specifically described below based on examples and comparative examples. Example 1 (Production of Polyhydroxy Resin A) In a 0.5 L four-neck separable flask, 45.4 g of 4,4'-dihydroxybiphenyl was dissolved in 165 g of N-methylpyrrolidone (NMP), and then 25.0 g of potassium carbonate was added. The mixture was heated to 100°C while stirring under a nitrogen stream. 25.0 g of 3,5-dibromotrifluoromethylbenzene (DBTFB) was then added, and the mixture was reacted at 160°C for 3 hours. 11.6 g of acetic acid was then added to the reaction solution to neutralize it, and the NMP was then distilled off under reduced pressure at 165°C. The product was washed with water and dried to obtain 56 g of a powdery polyhydric hydroxy resin (polyhydric hydroxy resin A). The hydroxyl equivalent of the obtained hydroxy resin A was 206 g / eq., and the melting point by the capillary method was 252°C. The GPC chart is shown in Figure 1. From this, it was found that the unreacted 4,4'-dihydroxybiphenyl was 42.7%, that in formula (1) n=1 was 30.6%, that n=2 was 14.9%, that n=3 was 6.7%, that n=4 was 2.8%, that n=5 was 1.1%, and that n=6 was 0.4%. The infrared absorption spectrum is shown in Figure 2. Here, the hydroxyl group equivalent was measured by potentiometric titration with potassium hydroxide in an acetyl chloride solution. GPC measurements were performed using an HLC-8320 (manufactured by Tosoh Corporation) and two TSKgel SuperHZ2500 columns and two TSKgel SuperHZ2000 columns (both manufactured by Tosoh Corporation) under the following conditions: solvent: tetrahydrofuran, flow rate: 0.35 ml / min, temperature: 40°C, detector: RI. Infrared absorption spectra were measured by the KBr tablet method using a JASCO FT / IR-6100 infrared absorption analyzer. Melting points by the capillary method were measured in accordance with JIS K 6910.

[0040] Example 2 (Production of Polyhydroxy Resin B) In a 1 L four-neck separable flask, 45.4 g of 4,4'-dihydroxybiphenyl was dissolved in 225 g of NMP, and then 26.8 g of potassium carbonate was added. The mixture was heated to 100°C while stirring under a nitrogen stream. 50.1 g of DBTFB was then added, and the mixture was reacted at 160°C for 3 hours. 23.3 g of acetic acid was then added to the reaction solution to neutralize it, and the NMP was then distilled off under reduced pressure at 165°C. The product was washed with water and dried to obtain 60 g of a powdery polyhydric hydroxy resin (polyhydric hydroxy resin B). The hydroxyl equivalent of the obtained hydroxy resin B was 385 g / eq., and the melting point by the capillary method was 178°C. The GPC chart is shown in Figure 3. From this, it was found that the unreacted 4,4'-dihydroxybiphenyl was 9.1%, and in formula (1), n=1 was 19.5%, n=2 was 18.9%, n=3 was 14.9%, n=4 was 11.3%, n=5 was 8.6%, n=6 was 5.5%, n=7 was 4.0%, n=8 was 3.0%, and n≧9 was 4.5%.

[0041] Example 3 (Production of Polyhydroxy Resin C) In a 0.5 L four-neck separable flask, 41.5 g of 2,2-bis(4-hydroxyphenyl)hexafluoropropane (BPAF) was dissolved in 125 g of NMP, and then 6.7 g of potassium carbonate was added. The mixture was heated to 120°C while stirring under a nitrogen stream. 12.5 g of DBTFB was then added, and the mixture was allowed to react at 160°C for 3 hours. 5.8 g of acetic acid was then added to the reaction solution to neutralize it, and the NMP was then distilled off under reduced pressure at 165°C. The product was washed with water and dried to obtain 46 g of a resin that was solid at room temperature (polyhydric hydroxy resin C). The resulting hydroxy resin A had a hydroxyl equivalent of 304 g / eq., a softening point of 45°C, and a melt viscosity of 0.2 Pa·s at 150°C. GPC analysis revealed that the unreacted BPAF was 38.4%, with n=1 in formula (1) being 32.6%, n=2 being 16.0%, n=3 being 7.2%, n=4 being 2.8%, n=5 being 1.2%, n=6 being 0.3%, and n≧7 being 0.3%.

[0042] Example 4 (Production of Epoxy Resin A) 40 g of the polyhydric hydroxy resin A obtained in Example 1 was dissolved in 470 g of epichlorohydrin (ECH) and 95 g of diglyme, and 21.9 g of 48.8% aqueous sodium hydroxide solution was added dropwise under reduced pressure at 65°C over 4 hours. During this time, the water produced was removed from the system by azeotropy with the ECH, and the distilled ECH was returned to the system. After the addition was completed, the reaction was continued for another hour. The ECH and diglyme were then distilled off under reduced pressure, and the resulting solution was dissolved in 200 mL of toluene. After filtration and washing with water to remove the salt produced, 1.1 g of 48.8% aqueous potassium hydroxide solution was added, and the reaction was continued for 1 hour at 80°C. The toluene was then distilled off under reduced pressure, yielding 48 g of an epoxy resin that was solid at room temperature (epoxy resin A). The resulting epoxy resin A had an epoxy equivalent of 232 g / eq., a softening point of 137°C, a melt viscosity at 150°C of 20 mPa·s, and a hydrolyzable chlorine content of 320 ppm. Figure 4 shows a GPC chart. From this, we can see that in formula (4), n=0 accounted for 42.4%, n=1 for 30.1%, n=2 for 14.9%, n=3 for 6.8%, n=4 for 2.9%, n=5 for 1.1%, and n=6 for 0.5%. Figure 5 also shows the infrared absorption spectrum. The hydrolyzable chlorine content was determined by dissolving 0.5 g of the resin sample in 30 ml of 1,4-dioxane, boiling and refluxing the solution in 5 ml of 1N KOH / methanol solution for 30 minutes, and then performing potentiometric titration with silver nitrate solution.

[0043] Example 5 (Production of Epoxy Resin B) 20 g of the polyhydric hydroxy resin B obtained in Example 2 was dissolved in 100 g of ECH and 30 g of diglyme, and 4.47 g of 48.8% aqueous sodium hydroxide solution was added dropwise at 65°C under reduced pressure over 4 hours. During this time, the water produced was removed from the system by azeotropy with the ECH, and the distilled ECH was returned to the system. After the addition was completed, the reaction was continued for another hour. The ECH and diglyme were then distilled off under reduced pressure, and the resulting solution was dissolved in 100 mL of toluene. After filtration and washing with water to remove the salt produced, 0.18 g of 48.8% aqueous potassium hydroxide solution was added, and the reaction was continued for 1 hour at 80°C. The toluene was then distilled off under reduced pressure, yielding 20 g of an epoxy resin that was solid at room temperature (epoxy resin B). The epoxy equivalent of the obtained epoxy resin B was 472 g / eq., the melting point by the capillary method was 169°C, and the hydrolyzable chlorine content was 230 ppm. GPC measurement showed that in formula (4), n=0 was 9.1%, n=1 was 19.4%, n=2 was 18.8%, n=3 was 14.9%, n=4 was 11.3%, n=5 was 8.1%, n=6 was 5.6%, n=7 was 4.0%, n=8 was 2.5%, and n≧9 was 5.8%.

[0044] Example 6 (Production of Epoxy Resin C) 30 g of the polyhydric hydroxy resin C obtained in Example 3 was dissolved in 195 g of ECH and 40 g of diglyme, and 9.1 g of 48.8% aqueous sodium hydroxide solution was added dropwise over 4 hours at 65°C under reduced pressure. During this time, the water produced was removed from the system by azeotropy with the ECH, and the distilled ECH was returned to the system. After the addition was completed, the reaction was continued for another hour. The ECH and diglyme were then distilled off under reduced pressure, and the resulting solution was dissolved in 200 mL of methyl isobutyl ketone (MIBK). After filtration and washing with water to remove the salt produced, 0.4 g of 48.8% aqueous potassium hydroxide solution was added, and the reaction was continued for 1 hour at 80°C. The MIBK was then distilled off under reduced pressure, yielding 36 g of an epoxy resin (epoxy resin C) that was viscous at room temperature. The epoxy equivalent of the resulting epoxy resin C was 366 g / eq., a viscous solid with a softening point of 50°C or less, a melt viscosity of 30 mPa·s at 150°C, and a hydrolyzable chlorine content of 280 ppm. GPC analysis revealed that in formula (4), n=0 was 38.8%, n=1 was 30.0%, n=2 was 15.7%, n=3 was 6.9%, n=4 was 2.9%, n=5 was 1.2%, n=6 was 0.5%, and n≧7 was 0.4%.

[0045] Examples 7 to 10 and Comparative Example 1 The polyhydroxy resins or epoxy resins synthesized in Examples 1 to 6, biphenyl-based epoxy resin (epoxy resin D: Mitsubishi Chemical Corporation, YX-4000H, epoxy equivalent 193, melting point 105°C), o-cresol novolac epoxy resin (epoxy resin E: Nippon Kayaku Corporation, EOCN-1020, epoxy equivalent 197, softening point 54°C), and phenol novolac (polyhydroxy resin D: OH equivalent 104, softening point 83°C, melt viscosity at 150°C 0.3 Pa s; BRG-557, AICA Corporation) were used in combination with triphenylphosphine as a curing accelerator to prepare resin compositions according to the formulations shown in Table 1. This was used for molding (150°C, 5 minutes), followed by post-curing (175°C, 4 hours) to obtain test pieces, which were then subjected to various physical property tests. The results are shown in Table 1.

[0046] [evaluation] (1) Glass transition temperature and thermal expansion coefficient The measurements were carried out using a thermomechanical measuring device, Model TMA7100, manufactured by Hitachi High-Tech Science Corporation, at a temperature rise rate of 10°C / min. (2) Pyrolysis temperature and residual carbon ratio Using a Hitachi High-Tech Science TG / DTA7300 thermogravimetric analyzer, the thermal decomposition temperature at a weight loss of 5 wt% and the residual carbon ratio at 700°C were determined under nitrogen flow at a heating rate of 10°C / min. (3) Thermal conductivity The thermal conductivity was measured by the xenon flash method using a NETZSCH LFA447 thermal conductivity meter. (4) Water absorption rate A disk with a diameter of 50 mm and a thickness of 3 mm was molded, and after post-curing, it was left to absorb moisture for 100 hours under conditions of 85°C and a relative humidity of 85%, after which the weight change rate was recorded.

[0047] [Table 1]

Claims

1. The following general formula (1): 【Chemistry 1】 and is a mixture with unreacted n=0, and has a hydroxyl group equivalent of 200 to 500 g / eq. In the general formula (1), A is the following formula (2): 【Chemistry 2】 (wherein X is a single bond, -CH ２ -, -CH(CH ３ ) -, -C(CH ３ ) ２ -, or -C(CF ３ ) ２ Indicates -. １ ~R ４ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. The bisphenylene group is represented by the formula: n is a number from 1 to 15, and the average value of n is from 0.5 to 5.

0.

2. With respect to 1 mole of an aromatic dihydroxy compound, a compound represented by the following general formula (3): 【Transformation 3】 (wherein each Y independently represents a halogen atom.) 2. The method for producing a polyvalent hydroxy resin according to claim 1, wherein 0.1 to 0.9 moles of a trifluoromethylbenzene compound represented by the formula:

3. The following general formula (4): 【Chemistry 4】 The epoxy resin is a mixture of unreacted n=0 and has an epoxy equivalent of 220 to 1000 g / eq. In the general formula (4), A is the following formula (2): 【Transformation 5】 (wherein X is a single bond, -CH ２ -, -CH(CH ３ ) -, -C(CH ３ ) ２ -, or -C(CF ３ ) ２ Indicates -. １ ~R ４ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. G represents a glycidyl group. n represents a number from 1 to 15, and the average value of n is 0.5 to 5.

0.

4. 4. The method for producing an epoxy resin according to claim 3, which comprises reacting the polyhydric hydroxy resin according to claim 1 with epichlorohydrin.

5. 10. An epoxy resin composition comprising an epoxy resin and a curing agent, wherein at least one of the polyhydroxy resin according to claim 1 and the epoxy resin according to claim 3 is blended as an essential component.

6. A cured product obtained by curing the epoxy resin composition according to claim 5.

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