Polyhydric hydroxyl resin, method for producing the same, and epoxy resin composition containing the same, and epoxy resin hardened product

Abstract

Provided is a polyhydric hydroxyl resin which is excellent in reliability, can be effectively used as an insulating material for electrical / electronic parts such as semiconductor sealing, laminated boards, and heat dissipation substrates, is excellent in handleability as a solid at normal temperature, and is excellent in low viscosity at the time of molding and solvent solubility, a method for producing the same, an epoxy resin composition containing the same, and an epoxy resin hardened product. The polyhydric hydroxyl resin represented by the following general formula (1) contains at least one ester structure.

Description

TECHNICAL FIELD

[0001] The present application relates to a polyhydric alcohol resin, a method for producing the same, an epoxy resin composition using the same, and an epoxy resin cured product, and more particularly to a polyhydric alcohol resin which is excellent in handling properties as a solid at normal temperature, low viscosity at the time of molding, and solvent solubility, and which is effective for an insulating material for electrical / electronic parts such as semiconductor sealing, laminated boards, heat dissipating substrates, and the like, a method for producing the same, an epoxy resin composition, and an epoxy resin cured product which is excellent in high thermal conductivity, heat resistance, and low thermal expansion by curing the same. BACKGROUND

[0002] In recent years, in electronic devices, high-density mounting of semiconductor packages, high integration and high speed of large scale integrated circuits (LSIs), and the like are sought, and a material having higher dimensional stability is sought. Further, due to the development of one-sided mounting of packages, reduction of warpage of the packages has become an important issue, and development of a resin having lower thermal expansion is required. In addition, in correspondence with the above trend, heat dissipation countermeasures for heat generated from elements have become a very important issue. In particular, in the field of power devices, since heat from electronic circuits becomes large, the heat dissipation property of a resin cured product for an insulating portion becomes a problem. With respect to the heat dissipation property, in the past, the thermal conductivity of a filler was utilized to cope with it, but toward further high integration, improvement of the thermal conductivity of a matrix resin itself is required.

[0003] As an epoxy resin composition excellent in high thermal conductivity, a composition using an epoxy resin having a mesogen structure is known, and for example, in Patent Document 1, an epoxy resin composition using a biphenol type epoxy resin and a polyhydric phenol resin curing agent as essential components is shown, and it is disclosed that the composition is excellent in stability and strength at high temperatures and can be used in a wide range of fields such as bonding, casting, sealing, molding, lamination, and the like. In addition, in Patent Document 2, an epoxy compound having two mesogen structures linked by a bent chain in the molecule is disclosed. Further, in Patent Document 3, a resin composition containing an epoxy compound having a mesogen group is disclosed.

[0004] However, the epoxy resin having such a liquid crystal primary structure has a high melting point, and in the case of performing a mixing process, the high melting point component is difficult to melt, and melting residue can occur, and thus there is a problem in that the curability or heat resistance is reduced. In addition, high temperatures are required to uniformly mix such an epoxy resin with a hardening agent. At high temperatures, the hardening reaction of the epoxy resin proceeds rapidly and the gelation time becomes short, and thus there is a problem in that the mixing process is strictly limited and is difficult to operate. Furthermore, if a third component that dissolves is added in order to compensate for this disadvantage, although the melting point of the resin is reduced and becomes easy to uniformly mix, the cured product thereof can have a problem in that the thermal conductivity is reduced.

[0005] As a high thermal conductive resin that can perform a melt mixing process, an epoxy resin obtained by epoxidizing a mixture of hydroquinone and 4,4'-dihydroxybiphenyl is disclosed in Patent Document 4, and an epoxy resin obtained by epoxidizing a mixture of 4,4'-dihydroxydiphenylmethane and 4,4'-dihydroxybiphenyl is disclosed in Patent Document 5. However, these resins lack solvent solubility, and the application use is limited.

[0006] An epoxy resin composition using a phenol compound having a diphenyl ester structure is disclosed in Patent Document 6, but since the melting point is high, it is difficult to uniformly melt and knead, and it is necessary to perform micro-pulverization using a jet mill or the like, and since it lacks solvent solubility, it is difficult to apply to a substrate or a sheet that must be varnished. In addition, a difunctional ester group-containing phenol of hydroquinone and p-hydroxybenzoic acid is disclosed in Patent Document 7, but since the crystallinity is high, there are problems in terms of solvent solubility and melt kneadability.

[0007] [Related Art Documents]

[0008] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Laid-Open No. 7-90052

[0010] [Patent Document 2] Japanese Patent Laid-Open No. 9-118673

[0011] [Patent Document 3] Japanese Patent Laid-Open No. 11-323162

[0012] [Patent Document 4] WO 2009 / 110424

[0013] [Patent Document 5] Japanese Patent Laid-Open No. 2010-43245

[0014] [Patent Document 6] Japanese Patent Laid-Open No. 2010-184993

[0015] [Patent Document 7] US 4762901 SUMMARY

[0016] [Problems to be solved by the invention]

[0017] Therefore, an object of the present application is to solve the problems described above, and to provide a polyhydric hydroxyl resin which is excellent in reliability, can be effectively used for an insulating material for an electrical / electronic component such as a semiconductor sealing, a laminated board, a heat dissipating substrate, etc., is excellent in handleability as a solid at ordinary temperature, and is excellent in low viscosity at the time of molding and solvent solubility, a method for producing the same, an epoxy resin composition containing the same, and an epoxy resin hardened product.

[0018] [Means of solving the problems]

[0019] The present inventors have found, as a result of intensive studies, that a polyhydric phenol resin having a specific ester group is expected to solve the problems described above, and that a hardened product thereof exhibits effects in terms of thermal conductivity.

[0020] That is, the present application relates to a polyhydric hydroxyl resin represented by the following general formula (1), characterized by containing at least one ester structure.

[0021] [Chemical Formula 1]

[0022]

[0023] (X represents an OH group or a monovalent substituent represented by formula (a), and n represents a number greater than 0 and 20 or less.)

[0024] [Chemical Formula 2]

[0025]

[0026] (Y represents an aromatic hydrocarbon group having 6 to 12 carbon atoms, R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms, and p represents a number of 1 to 3.)

[0027] The polyhydric hydroxyl resin preferably has a number average molecular weight of 3,000 or less.

[0028] Further, the present application relates to a method for producing a polyhydric hydroxyl resin, which is a method for producing the polyhydric hydroxyl resin, characterized by reacting 0.1 mole to 0.7 mole of an OH group-containing ester represented by general formula (3) with 1 mole of an OH group of a polyhydric hydroxyl resin represented by general formula (2).

[0029] [Chemical Formula 3]

[0030]

[0031] (X represents an OH group or a monovalent substituent represented by formula (a), and n represents a number greater than 0 and 20 or less.)

[0032] [Chemical Formula 4]

[0033]

[0034] (wherein Y represents an aromatic hydrocarbon group having 6 to 12 carbons, R and R 1 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbons, and p represents a number of 1 to 3.)

[0035] Further, the present application relates to an epoxy resin composition comprising an epoxy resin and a hardening agent, the epoxy resin composition being characterized in that, as a part or all of the hardening agent, the polyvalent hydroxyl resin according to any one of the above is used as an essential component.

[0036] As the epoxy resin of the epoxy resin composition of the present application, a difunctional crystalline epoxy resin is preferred.

[0037] Further, the present application relates to an epoxy resin hardened product obtained by hardening the epoxy resin composition.

[0038] [EFFECTS OF THE INVENTION]

[0039] The polyvalent hydroxyl resin of the present application and the epoxy resin composition using the same are excellent in solvent solubility, moldability, and reliability, and can exhibit excellent high thermal conductivity of the hardened product. Further, the yield is improved by suppressing crystallinity, and is also advantageous in terms of production. Furthermore, the polyvalent hydroxyl resin having a basic skeleton of hydroquinone exhibits an effect of suppressing polymerization caused by self-polymerization at the time of esterification. Thus, control of the molecular weight and the ratio of esterification, which is usually difficult, can be achieved. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 is a gel permeation chromatography (GPC) chart of the polyvalent hydroxyl resin containing an ester group (Example 1).

[0041] Figure 2 is an infrared ray (IR) chart of the polyvalent hydroxyl resin containing an ester group (Example 1).

[0042] Figure 3 is a field desorption-mass spectrometry (FD-MS) spectrum of the polyvalent hydroxyl resin containing an ester group (Example 1). DETAILED DESCRIPTION

[0043] Hereinafter, the present application will be described in detail.

[0044] The polyhydric hydroxyl resin of the present application is represented by the general formula (1) and contains at least one ester structure represented by formula (a). n is the number of repetitions (number average) and represents a number greater than 0 and 20 or less. The component with n = 0 has the strongest crystallinity, has excellent orientation, on the other hand, has low solvent solubility, and thus it is preferable to be a mixture of components having different n values. Further, the component with a large n has high viscosity, which can reduce flowability, and because of self-aggregation, dissolution in a solvent also requires a long time, and thus it is more preferable to be a mixture of components with n greater than 0 and 10 or less. As the molecular weight, it is preferable to be 3000 or less in terms of the number average molecular weight.

[0045] The ester structure as a monovalent substituent is represented by the formula (a), Y represents an aromatic hydrocarbon group having 6 to 12 carbons, R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbons, and p represents a number of 1 to 3. The preferred structure of Y is a benzene ring, a naphthalene ring, or a biphenyl structure. Further, the more rigid polycyclic aromatic hydrocarbon, the more it contributes to orientation and thermal stability, but the solvent solubility decreases, and it is difficult to balance reactivity, and thus the more preferred structure is a benzene ring. As for the structure in which the number of OH groups of the monovalent substituent is 2 or more, because the reaction control is complex and sharp, in addition, it is difficult to universally supply raw materials, p is more preferably 1.

[0046] The polyhydric hydroxyl resin represented by the general formula (1) containing an ester structure can be obtained by reacting a polyhydric hydroxyl resin represented by the general formula (2) with an OH group-containing ester represented by the general formula (3) in the presence of an acid catalyst. This reaction can be performed using the conditions for esterification in general. Here, the polyhydric hydroxyl resin represented by the general formula (2) can be obtained from the condensation reaction of hydroquinone and formaldehyde. The method is a general method for producing a phenol resin, and as the formaldehyde, paraformaldehyde or formalin can be used, and the reaction can be performed in the presence of an acid catalyst. The ratio of formaldehyde used as the condensing agent is preferably in the range of 0.1 to 0.5 mol, more preferably in the range of 0.2 to 0.4 mol, per 1 mol of the OH group of hydroquinone. In the case of more than 0.5 mol, the tackiness is increased and the solvent solubility is decreased, and thus the handling is difficult. In the case of less than 0.1 mol, the high molecular weight component is small, and a large amount of unreacted monomer remains, and there is a concern that the heat resistance, thermal conductivity, mechanical strength and the like of the hardened product are decreased. In addition, in the case of removing a large amount of unreacted hydroquinone, a high-temperature high-pressure process is required, and this is a problem in the production, and thus the above range is preferred. In addition, as the OH group-containing ester represented by the general formula (3), there are p-hydroxybenzoic acid, 4-hydroxy-2-methylbenzoic acid, 4-hydroxy-3-methylbenzoic acid, 2,4-dihydroxybenzoic acid, 3,4-dihydroxybenzoic acid, 6-hydroxy-2-naphthoic acid, 3,5-dihydroxy-2-naphthoic acid, 4-(4-hydroxyphenyl)benzoic acid, and as the carboxylic acid ester, there are methyl p-hydroxybenzoate, ethyl p-hydroxybenzoate, methyl 6-hydroxy-2-naphthoate, ethyl 6-hydroxy-2-naphthoate, methyl 4'-hydroxy[l,l'-biphenyl]-4-carboxylate, and the like, and from the viewpoints of reactivity and solvent solubility, p-hydroxybenzoic acid and methyl p-hydroxybenzoate are preferred. As the modification rate of esterification in the reaction, 0.1 to 0.7 mol of the OH group-containing ester represented by the general formula (3) is reacted per 1 mol of the OH group of the polyhydric hydroxyl resin represented by the general formula (2). In the case of less than 0.1 mol, the effect of promoting the orientation is small, and the improvement of the thermal conductivity at the time of hardening cannot be expected. On the other hand, in the case of more than 0.7 mol, the steric hindrance is large, and this becomes a cause of irregularity in the orientation, and thus is not preferred. In addition, since the self-polymerization of the OH group-containing carboxylic acid as a side reaction also easily occurs, partial esterification is preferred. From the viewpoint of improving the thermal conductivity of the hardened product, further, the range of 0.4 to 0.6 mol is preferred.

[0047] The epoxy resin composition of the present application is an epoxy resin composition containing an epoxy resin and a hardener, and as part or all of the hardener, the polyhydric hydroxyl resin represented by the general formula (1) is formulated as an essential component.

[0048] The amount of the epoxy resin is adjusted in consideration of the equivalent balance with the OH groups of the hardener. The OH groups of the hardener are generally in the range of 0.5 equivalents to 2.0 equivalents, and preferably in the range of 0.7 equivalents to 1.5 equivalents, relative to 1 equivalent of the epoxy groups. If the range is deviated, unreacted monomers remain, and there is a concern that the heat resistance, thermal conductivity, mechanical strength, and the like of the hardened product decrease.

[0049] In the epoxy resin composition, as the hardener component, other types of hardeners than the polyvalent hydroxyl resin of the present application represented by General Formula (1) can also be adjusted, and generally known substances as hardeners can be used. As such other types of hardeners, for example, dicyandiamine, polyvalent phenols, acid anhydrides, aromatic and aliphatic amines, and the like are exemplified. If specific examples are exemplified, as the polyvalent phenols, for example, diphenylol A, diphenylol F, diphenylol S, fluorene bisphenol, 4,4'-diphenylol, 2,2'-diphenylol, hydroquinone, resorcinol, naphthalene diol, or the like, or phenol novolac, o-cresol novolac, naphthol novolac, polyvinyl phenol, or the like represented by triphenols of three or more valences are exemplified. Further, polyvalent phenolic compounds synthesized by condensing phenol, naphthol, or diphenylol A, diphenylol F, diphenylol S, fluorene bisphenol, 4,4'-diphenylol, 2,2'-diphenylol, hydroquinone, resorcinol, naphthalene diol, or the like with a condensing agent such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, p-xylyleneglycol, or the like are exemplified.

[0050] As the acid anhydride, phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylhimic anhydride, nadic anhydride, trimellitic anhydride, and the like are exemplified.

[0051] Further, as the amine, aromatic amines such as 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylsulfone, m-phenylenediamine, p-xylylenediamine, and the like, aliphatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, and the like are exemplified.

[0052] In the resin composition of the present application, one or a mixture of two or more of the hardening agents can be used. Also, in the case of the epoxy resin composition of the present application, the polyvalent hydroxyl resin represented by General Formula (1) can be used in a blending amount of 5 to 100% by weight, preferably 60 to 100% by weight, in the entire hardening agent. As other kinds of hardening agents, from the viewpoint of reliability and thermal conductivity of the hardened product, a dihydric phenol is preferred, and 4,4'-diphenylol phenyl, 2,2'-diphenylol phenyl, hydroquinone, resorcinol, naphthalene diol, 4,4'-dihydroxy diphenyl ether are more preferred.

[0053] As the epoxy resin component in the epoxy resin composition of the present application, any of the usual epoxy resins having two or more epoxy groups in the molecule can be used. If exemplified, there are diglycidyl ethers derived from bisphenol A, bisphenol F, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, fluorene bisphenol, 4,4'-diphenylol phenyl, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenyl, 2,2'-diphenylol phenyl, resorcinol, catechol, t-butylcatechol, t-butylhydroquinone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allyl or polyallyl compounds of the dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenol novolacs, and the like dihydric phenols; or phenol novolacs, bisphenol A novolacs, o-cresol novolacs, m-cresol novolacs, p-cresol novolacs, dimethylphenol novolacs, poly-p-hydroxystyrene, tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, phloroglucinol, pyrocatechol, t-butylpyrocatechol, allylated pyrocatechol, polyallylated pyrocatechol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, phenol aralkyl resins, naphthol aralkyl resins, dicyclopentadiene-based resins, and the like trihydric or higher phenols; or halogenated bisphenols such as tetrabromobisphenol A, and the like glycidyl ether derivatives. One or a mixture of two or more of these epoxy resins can be used.

[0054] In order to obtain a hardened product having excellent thermal conductivity, a difunctional epoxy resin having strong crystallinity is preferred. For example, glycidyl ether derivatives derived from dihydric phenols such as 4,4'-diphenylol phenyl, 2,2'-diphenylol phenyl, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl ether, and the like. An epoxy compound containing 4,4'-diphenylol phenyl is particularly preferred.

[0055] In the epoxy resin composition of the present application, an oligomer or a high molecular compound such as a polyester, a polyamide, a polyimide, a polyether, a polyurethane, a petroleum resin, an indene resin, an indene-benzofuran resin, a phenoxy resin, or the like can be appropriately added as another modifier or the like. As to the amount of addition, it is usually in the range of 1 to 30 parts by weight, relative to 100 parts by weight of the total of the resin components.

[0056] In addition, in the epoxy resin composition of the present application, an inorganic filler, a pigment, a flame retardant, a warpage imparting agent, a coupling agent, a flowability improving agent, or the like can be added. As the inorganic filler, for example, there can be mentioned a spherical or crushed fused silica, a crystalline silica powder, an alumina powder, a glass powder, or mica, talc, calcium carbonate, alumina, hydrated alumina, or the like, and the preferable amount of addition when used for a semiconductor sealing material is 70% by weight or more, and further preferably 80% by weight or more.

[0057] As the pigment, there are a bulk pigment, a flaky pigment, or the like of an organic or inorganic system. As the warpage imparting agent, there can be mentioned a silicon system, a castor oil system, an aliphatic amide wax, an oxidized polyethylene wax, an organic bentonite system, or the like.

[0058] Further, in the epoxy resin composition of the present application, a hardening accelerator can be used as necessary. If exemplified, there are an amine system, an imidazole system, an organic phosphine system, a Lewis acid, or the like, and specifically there are 1,8-diazabicyclo(5,4,0)undecene-7, triethylenediamine, benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol, or the like tertiary amine; 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, or the like imidazole; tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, or the like organic phosphine; tetraphenylphosphonium-tetraphenylborate, tetraphenylphosphonium-ethyltriphenylborate, tetrabutylphosphonium-tetrabutylborate, or the like tetra-substituted phosphonium-tetra-substituted borate, 2-ethyl-4-methylimidazole-tetraphenylborate, N-methylmorpholine-tetraphenylborate, or the like tetraphenylborate. As to the amount of addition, it is usually in the range of 0.01 to 5 parts by weight, relative to 100 parts by weight of the total of the resin components.

[0059] Further, a release agent such as carnauba wax, OP wax, or the like, a coupling agent such as γ-glycidoxypropyltrimethoxysilane or the like, a colorant such as carbon black or the like, a flame retardant such as antimony trioxide or the like, a low stress agent such as silicone oil or the like, a lubricant such as calcium stearate or the like, or the like can be used in the epoxy resin composition of the present application as necessary.

[0060] The epoxy resin composition of the present application, after being dissolved in an organic solvent to be in a varnish state, can be impregnated in a fibrous material such as a glass cloth, a polyaramide nonwoven fabric, a polyester nonwoven fabric of a liquid crystal polymer, and the like, and then subjected to solvent removal to produce a prepreg. Alternatively, depending on the case, a laminate can be produced by coating on a sheet material such as a copper foil, a stainless steel foil, a polyimide film, a polyester film, and the like.

[0061] If the epoxy resin composition of the present application is heat-hardened, a resin hardened product of the present application can be produced. The hardened product can be obtained by subjecting the epoxy resin composition to molding processing by a known method such as casting, compression molding, transfer molding, and the like. The temperature at this time is usually in the range of 100°C to 220°C.

[0062] [Examples]

[0063] Hereinafter, the present application will be specifically described by citing a synthesis example, examples, and comparative examples. However, the present application is not limited to these. Unless otherwise specified, "parts" means parts by weight, and "%" means % by weight. Also, regarding the measurement method, each was measured by using the following method.

[0064] 1) Measurement of OH equivalent

[0065] About 6 mg / eq of a sample was precisely weighed in a 100 mL flask with a common plug, 3 mL of a reagent mixed at acetic anhydride / pyridine = 3 / 1 (volume ratio) was added, a cooling tube was attached, and heating was performed by a hot plate to reflux for 5 minutes. After being left to cool for 5 minutes, 1 mL of water was added. The liquid was subjected to potentiometric titration with a 0.5 mol / L KOH / MeOH solution, and the OH equivalent was calculated therefrom.

[0066] 2) Measurement of epoxy equivalent

[0067] Using a potentiometric titration device, using methyl ethyl ketone as a solvent, adding a tetraethylammonium bromide acetic acid solution, and measuring by potentiometric titration using a 0.1 mol / L perchloric acid-acetic acid solution.

[0068] 3) Melting point

[0069] Using a differential scanning calorimetry device (EXSTAR 6000 DSC / 6200 manufactured by SII NanoTechnology, Inc.), the differential scanning calorimetry (DSC) peak temperature was found under the condition of a temperature increase rate of 5°C / min. That is, the DSC peak temperature was taken as the melting point of the resin.

[0070] 4) Melt viscosity

[0071] The measurement was performed at 150°C using a CAP2000H-type rotational viscometer manufactured by the BROOKFIELD Company.

[0072] 5) Softening point

[0073] The measurement was performed by the ring and ball method according to Japanese Industrial Standards (JIS)-K-2207.

[0074] 6) GPC measurement

[0075] The apparatus had a column (manufactured by Tosoh Corporation, TSKgel G4000HXL, TSKgel G3000HXL, TSKgel G2000HXL) connected in series, and the column temperature was set to 40°C. In addition, tetrahydrofuran (THF) was used as the eluent at a flow rate of 1 mL / min, and a differential refractive index detector was used as the detector. The sample to be measured was 50 μL of a sample obtained by dissolving 0.1 g of a sample in 10 mL of THF and filtering with a microfilter. The data processing used a GPC-8020 Model II Version 6.00 manufactured by Tosoh Corporation. In addition, the number average molecular weight (Mn) was calculated using a calibration curve obtained from a standard polystyrene.

[0076] 7) Glass transition point (Tg)

[0077] The Tg was calculated at a temperature increase rate of 10°C / min using a thermal mechanical measurement apparatus (EXSTAR 6000 TMA / 6100 manufactured by SII NanoTechnology, Inc.).

[0078] 8) 10% weight reduction temperature (Td10), residual carbon rate

[0079] The 10% weight reduction temperature (Td10) was measured at a temperature increase rate of 10°C / min under a nitrogen atmosphere using a thermogravimetric / differential thermal analysis apparatus (EXSTAR 6000 TG / DTA6200 manufactured by SII NanoTechnology). In addition, the weight reduction at 700°C was measured, and the residual carbon rate was calculated.

[0080] 9) Thermal conductivity

[0081] The thermal conductivity was measured by the transient hot wire method using a thermal conductivity meter, LFA447 manufactured by NETZSCH.

[0082] 10) Infrared absorption (IR) measurement

[0083] The absorbance at a wave number of 400 cm"1~4000 cm"1was measured by the total reflection measurement method (attenuated total reflection (ATR) method) using a Fourier transform infrared spectrophotometer (Frontier Gold FT-IR Spectrometer) manufactured by Perkinelmer Inc. -1 ~4000 cm -1

[0084] 11) Field desorption mass spectrometry (FD-MS)

[0085] The measurement was performed using a mass spectrometer JMS-T100GCV manufactured by JEOL Ltd. The sample was dissolved in acetone for the measurement.

[0086] Reference Example 1

[0087] A flask equipped with a Dean-Stark tube was charged with hydroquinone 300.0 g, paraformaldehyde 28.9 g, and diethylene glycol dimethyl ether 263.1 g, and the mixture was dissolved by heating to about 100°C under nitrogen flow while stirring. Next, p-toluenesulfonic acid 0.33 g was added, and the temperature was raised to 160°C, and the mixture was reacted for 6 hours while removing water. Diethylene glycol dimethyl ether was distilled off, and methyl isobutyl ketone was added, and the mixture was neutralized, washed with water, and filtered. Next, methyl isobutyl ketone was distilled off under reduced pressure to obtain a polyhydric alcohol resin a of general formula (2) 295.1 g. The OH equivalent weight of the polyhydric alcohol resin a was 59 g / eq. The number average molecular weight was 430, and it was a mixture of n (number average) of 0 to 5.

[0088] Example 1

[0089] ​The polybasic hydroxyl resin a obtained in Reference Example 1, 50.0 g (about 0.85 mole), p-hydroxybenzoic acid, 58.5 g (about 0.42 mole), chlorobenzene, 200.0 g, p-toluenesulfonic acid, 1.9 g were charged in a flask equipped with a Dean-Stark tube, and heated to 120°C under nitrogen stream while stirring, and a reaction was carried out for 5 hours while dehydrating water in the system by refluxing. After cooling to room temperature, filtration, water washing were repeated, and drying under reduced pressure was carried out, whereby a yellowish-brown powder of ester group-containing polybasic hydroxyl resin A, 44.9 g was obtained. The number average molecular weight was 484, and it was a mixture of n (number average) = 0 to 5. Further, the content of n = 0 (GPC area %) was 11 area %. The GPC chart is shown in Figure 1 The IR chart is shown in Figure 2 The FD-MS spectrum is shown in Figure 3 As for the melting point based on DSC, three peak temperatures of 177°C, 193°C, and 247°C were confirmed. The OH equivalent was calculated to be 119 g / eq. from the results of analysis of each component by GPC, FD-MS, and the input ratio.

[0090] Example 2

[0091] A reaction was carried out in the same manner as in Example 1 except that 6-hydroxy-2-naphthoic acid, 79.7 g (about 0.42 mole) was used instead of p-hydroxybenzoic acid, and a tan powder of ester group-containing polybasic hydroxyl resin, 87.9 g (polybasic hydroxyl resin B) was obtained. The OH equivalent of the resin was calculated to be 156 g / eq.

[0092] Reference Example 2

[0093] In a flask equipped with a Dean-Stark tube, hydroquinone, 50.0 g, p-hydroxybenzoic acid, 39.9 g, boric acid, 0.75 g, sulfuric acid, 3.1 g, xylene, 400 g were charged, and heated to 130°C under nitrogen stream while stirring, and a reaction was carried out for 5 hours while dehydrating water in the system by refluxing. After cooling to room temperature, filtration, neutralization were carried out, and then water washing was repeated, and further washing with methanol was carried out, and drying under reduced pressure was carried out, whereby white crystals, 54.1 g were obtained. The OH equivalent was calculated to be 115 g / eq., and the melting point based on DSC was 240°C.

[0094] Reference Example 3

[0095] Hydroquinone 50.0 g, 4,4'-dihydroxydiphenyl 100.0 g were dissolved in epichlorohydrin 1000 g, diethylene glycol dimethyl ether 150 g, and 48% sodium hydroxide 16.5 g was added at 60°C, and stirred for 1 hour. Thereafter, 48% aqueous sodium hydroxide solution 148.8 g was added dropwise under reduced pressure (about 130 Torr) over 3 hours. During this time, the generated water was removed from the system by azeotropy with epichlorohydrin, and the distilled epichlorohydrin was returned to the system. After the dropwise addition was completed, the reaction was further continued for 1 hour for dehydration, and thereafter, the epichlorohydrin was distilled off, methyl isobutyl ketone 600 g was added, and the salt was removed by water washing. Thereafter, 48% sodium hydroxide 13.5 g was added at 85°C, and stirred for 1 hour, and water washing was performed with warm water 200 mL. Thereafter, the water was removed by liquid separation, and the methyl isobutyl ketone was distilled off under reduced pressure, and a white crystalline modified epoxy resin (epoxy resin A) 224 g was obtained. The epoxy equivalent was 138, the hydrolyzable chlorine was 320 ppm, the melting point based on the capillary method was 104°C to 141°C, and the viscosity at 150°C was 3.4 mPa-s.

[0096] Examples 3 to 7, Comparative Examples 1 to 5

[0097] As the epoxy resin component, the epoxy resin of Reference Example 3 (epoxy resin A), an epoxide of 4,4'-dihydroxydiphenyl ether (epoxy resin B: manufactured by NIPPON STEEL Chemical & Material, YSLV-80DE 163 g / eq.), a biphenyl-based epoxy resin (epoxy resin C: manufactured by Japan Epoxy Resin, YX-4000H, epoxy equivalent 188 g / eq.), or a phenol novolak-type epoxy resin (epoxy resin D: manufactured by NIPPON STEEL Chemical & Material, YDPN-638, epoxy equivalent 177 g / eq.) were used, and as the hardener, the polyvalent hydroxyl resin A of Example 1 (hardener A), the polyvalent hydroxyl resin B of Example 2 (hardener B), the polyvalent hydroxyl resin a of Reference Example 1 (hardener C), hydroquinone (hardener D), a phenol novolak resin (hardener E: hydroxyl equivalent 105, softening point 67°C), or the reactant of hydroquinone and p-hydroxybenzoic acid of Reference Example 2 (hardener F) were used. In addition, as the hardening accelerator, triphenylphosphine was used, and epoxy resin compositions were obtained in the formulations shown in Table 1. The values in the table indicate parts by weight in the formulation. Using the epoxy resin compositions, molding was performed at 175°C, post-curing was performed at 175°C for 5 hours, and hardened test pieces were obtained, and thereafter, various physical property measurements were performed.

[0098] [Table 1]

[0099]

[0100] As is clear from these results, the epoxy resin compositions obtained in the examples are excellent in moldability, the thermal conductivities of their cured products are good, the heat resistance and low thermal expansion can be confirmed, and thus are suitable for power devices and vehicle uses.

Claims

1. A polyol resin characterized in that, represented by the following general formula (1) and containing at least one ester structure, Here, X represents an OH group or a monovalent substituent represented by formula (a), at least one of which is formula (a); n represents a number greater than 0 and 20 or less; Here, Y represents an aromatic hydrocarbon group having 6 to 12 carbons, R represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbons, and p represents a number of 1 to 3.

2. The polyhydroxy resin of claim 1, wherein, The number average molecular weight is 3000 or less.

3. A method for producing a polyhydroxy resin according to claim 1 or 2, characterized by comprising, reacting 0.1 moles to 0.7 moles of a compound represented by general formula (3) with 1 mole of OH groups of a polyhydroxy resin represented by general formula (2), Here, n represents a number greater than 0 and 20 or less; Here, Y represents an aromatic hydrocarbon group having 6 to 12 carbons, R and R 1 each independently represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbons, and p represents a number of 1 to 3.

4. An epoxy resin composition comprising an epoxy resin and a hardening agent, characterized in that the polyhydroxy resin according to claim 1 or 2 is used as part or all of the hardening agent.

5. The epoxy resin composition according to claim 4, characterized in that The epoxy resin is a difunctional crystalline epoxy resin.

6. An epoxy resin hardened product obtained by hardening the epoxy resin composition according to claim 4 or 5.

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