JP2015160893A - Epoxy resin composition and hardened product of the shame - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an epoxy resin composition which provides a hardened product excellent in heat resistance, thermal decomposition stability and mechanical strength retention and also in fluidity during molding and is suitable for power device sealing materials and its resin hardened product.SOLUTION: An epoxy resin composition comprises an epoxy resin and an epoxy resin hardening agent and contains 50% or more of a biphenyl aralkyl type epoxy resin as the epoxy resin, and the epoxy resin used contains at least 10% of one or more polyfunctional epoxy resins selected from bisphenol methane type epoxy resin, trisphenol methane type epoxy resin and tetrakisphenol ethane type epoxy resin. The epoxy resin composition uses as a phenol-based hardening agent as the hardening agent.

Description

  The present invention relates to an epoxy resin composition and a cured product excellent in solvent solubility, high thermal conductivity, and insulation.

  Epoxy resins have been used in a wide range of industrial applications, but their required performance has become increasingly sophisticated in recent years. Among them, as an epoxy resin composition excellent in high thermal conductivity, one using an epoxy resin having a mesogenic structure is known. For example, Patent Document 1 discloses a biphenol type epoxy resin and a polyhydric phenol resin. An epoxy resin composition containing a curing agent as an essential component is shown, and it is disclosed that it is excellent in stability and strength at high temperatures and can be used in a wide range of fields such as adhesion, casting, sealing, molding and lamination. Patent Document 2 discloses an epoxy compound having in its molecule two mesogenic structures connected by a bent chain. Furthermore, Patent Document 3 discloses a resin composition containing an epoxy compound having a mesogenic group.

Japanese Patent Laid-Open No. 7-90052 JP-A-9-118673 JP-A-11-323162 JP-A-4-255714 Japanese Patent Laid-Open No. 10-292032 WO2011 / 074517

  However, the epoxy resin having such a mesogenic structure has a high melting point, and when performing a mixing process, the high melting point component is difficult to dissolve and remains undissolved, resulting in a problem that curability and heat resistance are lowered. Moreover, the mesogen-based poxy resin composition has low solvent solubility, and there has been a problem in application to epoxy resin compositions such as varnish. High temperature is required to uniformly mix such an epoxy resin with a curing agent. At high temperatures, the curing reaction of the epoxy resin proceeds rapidly and the gelation time is shortened, so that the mixing process is severely limited and difficult to handle. When a soluble third component is added to make up for the drawback, the melting point of the resin is lowered to facilitate uniform mixing, but the cured product has a problem that the thermal conductivity is lowered.

  On the other hand, Patent Documents 4 and 5 disclose a biphenol aralkyl type epoxy resin and a resin composition thereof, which are described as being excellent in heat resistance, moisture resistance, mechanical properties, etc. None focused on thermal conductivity. Patent Document 6 describes an aralkyl type epoxy resin having a biphenyl ring and a composition containing the same.

  The purpose of the present invention is to seal electrical and electronic components that give a cured product that is excellent in solvent solubility, high thermal conductivity, insulation, etc. in applications such as lamination, molding, casting, and adhesion, An object of the present invention is to provide an epoxy resin composition useful for circuit board materials and the like and to provide a cured product thereof.

（但し、ｋは平均値として０．２〜４．０を示し、ｔは１又は２の数を示し、Ｇはグリシジル基を示す。）

（但し、ｌは１以上の数を示し、Ｇはグリシジル基を示す。）

（但し、ｍは０以上の数を示し、Ｇはグリシジル基を示す。）

（但し、ｎは０以上の数を示し、Ｇはグリシジル基を示す。） The present invention is an epoxy resin composition containing an epoxy resin and a phenolic curing agent, containing 50 wt% or more of an epoxy resin represented by the following general formula (1), and the general formulas (2) to (4) 10 wt% or more of any of the epoxy resins represented by

(However, k shows 0.2-4.0 as an average value, t shows the number of 1 or 2, and G shows a glycidyl group.)

(However, l represents a number of 1 or more, and G represents a glycidyl group.)

(However, m represents a number of 0 or more, and G represents a glycidyl group.)

(However, n represents a number of 0 or more, and G represents a glycidyl group.)

  Moreover, this invention is said epoxy resin composition characterized by containing an inorganic filler. Furthermore, this invention is an epoxy resin hardened | cured material characterized by hardening said epoxy resin composition.

  If the epoxy resin composition containing the epoxy resin of the present invention is cured by heating, it can be made into an epoxy resin cured product. This epoxy resin composition has excellent solvent solubility, and the cured product obtained therefrom has a high thermal conductivity. It is excellent in terms of insulation and the like, and can be suitably used for applications such as sealing materials for electrical and electronic parts, high heat dissipation sheets for semiconductor modules, circuit board materials, and the like.

  Hereinafter, the present invention will be described in detail.

（但し、ｎは平均値として０．２〜４．０を示し、ｔは１又は２の数を示す。）

（但し、ｔは１又は２の数を示し、Ｘは水酸基、ハロゲン原子又は炭素数１〜６のアルコキシ基を示す。） The epoxy resin represented by the general formula (1), which is an essential component of the epoxy resin composition of the present invention, reacts a polyvalent hydroxy resin represented by the following general formula (a) with epichlorohydrin. Can be manufactured. The polyvalent hydroxy resin can be produced by reacting 4,4′-biphenol and a condensing agent represented by the following general formula (b).

(However, n represents an average value of 0.2 to 4.0, and t represents a number of 1 or 2.)

(However, t shows the number of 1 or 2, X shows a hydroxyl group, a halogen atom, or a C1-C6 alkoxy group.)

  4,4'-dihydroxybiphenyl is used as a raw material for synthesizing the polyvalent hydroxy resin, but a small amount of an isomer such as 2,2'-dihydroxybiphenyl may be used in such a range that the thermal conductivity does not decrease. These dihydroxybiphenyls are preferably unsubstituted from the viewpoint of thermal conductivity expression, but contain dihydroxybiphenyls having a hydrocarbon group having 1 to 6 carbon atoms as a substituent in a range that does not cause deterioration in physical properties. Also good. Examples of the hydrocarbon substituent include a methyl group, an ethyl group, an isopropyl group, an allyl group, a tertiary butyl group, an amyl group, a cyclohexyl group, and a phenyl group.

In general formula (b), t shows the number of 1 or 2, and X shows a hydroxyl group, a halogen atom, or a C1-C6 alkoxy group. The phenyl-based condensing agent in which t is 1 may be any of o-, m-, and p-forms, and preferably m-forms and p-forms. Specifically, p-xylylene glycol, α, α′-dimethoxy-p-xylene, α, α′-diethoxy-p-xylene, α, α′-diisopropyl-p-xylene, α, α′-dibutoxy -P-xylene, m-xylylene glycol, α, α'-dimethoxy-m-xylene, α, α'-diethoxy-m-xylene, α, α'-diisopropoxy-m-xylene, α, α ' -Dibutoxy-m-xylene etc. are mentioned.
Specific examples of the biphenyl condensing agent in which t is 2 include 4,4′-bishydroxymethylbiphenyl, 4,4′-bischloromethylbiphenyl, 4,4′-bisbromomethylbiphenyl, 4, Examples include 4'-bismethoxymethylbiphenyl and 4,4'-bisethoxymethylbiphenyl. From the viewpoint of reactivity, 4,4′-bishydroxymethylbiphenyl and 4,4′-bischloromethylbiphenyl are preferable. From the viewpoint of reducing ionic impurities, 4,4′-bishydroxymethylbiphenyl, 4 4,4'-bismethoxymethylbiphenyl is preferred.

  The molar ratio at the time of reaction is preferably 1 mol or less of the condensing agent with respect to 1 mol of 4,4′-dihydroxybiphenyl, generally in the range of 0.1 to 0.7 mol, more preferably 0. The range is from 2 to 0.5 mol. If it is less than this, the crystallinity becomes strong, the solubility in epichlorohydrin when synthesizing the epoxy resin is lowered, the melting point of the obtained epoxy resin is increased, and the handleability is lowered. On the other hand, if the amount is larger than this, the crystallinity of the resin is lowered and the softening point and the melt viscosity are increased, which hinders handling workability and moldability.

  In general formulas (1), (a) and (b), common symbols have the same meanings unless otherwise specified. K in the general formula (1) and n in the general formula (a) usually have the same meaning. k and n are 0.2 to 4.0 as an average value (number average), preferably 0.4 to 2.0. These are related to epoxy equivalent or hydroxyl equivalent, and the epoxy equivalent is preferably in the range of 150 to 500 g / eq. The epoxy equivalent is also related to the softening point or melting point of the epoxy resin, and the softening point or melting point is increased by increasing the epoxy equivalent.

  The softening point or melting point of the epoxy resin represented by the general formula (1) can be easily adjusted by changing the molar ratio of the biphenols and the crosslinking agent when synthesizing the polyvalent hydroxy resin which is the epoxy resin raw material. However, the softening point or melting point is preferably 130 ° C. or lower, more preferably 120 ° C. or lower, from the viewpoint of suppressing deterioration in physical properties due to unmelted high melting point components when preparing the epoxy resin composition. When the softening point or melting point is higher than this, physical properties such as curability and heat resistance tend to be lowered.

  Moreover, when using the bischloromethyl compound whose X in General formula (b) is Cl as a condensing agent, it can also make it react in the absence of a catalyst, However, It is preferable to carry out in presence of an acidic catalyst. The acidic catalyst can be appropriately selected from known inorganic acids and organic acids. For example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, metasulfone Examples thereof include organic acids such as acid and trifluorometasulfonic acid, Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride, and solid acids.

  The reaction of reacting 4,4′-biphenol and the condensing agent represented by the general formula (b) is performed at 10 to 250 ° C. for 1 to 20 hours. In the reaction, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve and ethyl cellosolve, and aromatic compounds such as benzene, toluene, chlorobenzene and dichlorobenzene can be used as a solvent. . After completion of the reaction, the solvent, water produced by the condensation reaction, alcohols, etc. are removed as necessary.

  The method for producing the epoxy resin of the present invention by the reaction between the polyvalent hydroxy resin represented by the general formula (a) and epichlorohydrin will be described. This reaction can be performed in the same manner as a well-known epoxidation reaction.

  For example, after the polyvalent hydroxy resin represented by the general formula (a) is dissolved in excess epichlorohydrin, it is 50 to 150 ° C., preferably 60 in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. The method of making it react for 1 to 10 hours in the range of -120 degreeC is mentioned. In this case, the amount of epichlorohydrin used is in the range of 0.8 to 2 mol, preferably 0.9 to 1.2 mol, relative to 1 mol of the hydroxyl group in the polyvalent hydroxy resin. Excess epichlorohydrin was distilled off after completion of the reaction, the residue was dissolved in a solvent such as toluene and methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the solvent was distilled off to remove the general formula ( The target epoxy resin represented by 1) can be obtained. When performing the epoxidation reaction, a catalyst such as a quaternary ammonium salt may be used.

The purity of the epoxy resin of the present invention, in particular the amount of hydrolyzable chlorine, is better from the viewpoint of improving the reliability of the applied electronic component. Although it does not specifically limit, Preferably it is 1000 ppm or less, More preferably, it is 500 ppm or less. In addition, the hydrolyzable chlorine as used in the field of this invention means the value measured by the following method. Specifically, 0.5 g of a sample was dissolved in 30 ml of dioxane, 1N-KOH, 10 ml was added, and the mixture was boiled and refluxed for 30 minutes. The mixture was cooled to room temperature, and further 100 ml of 80% acetone water was added, and a potential difference was obtained with 0.002N-AgNO ₃ aqueous solution. This is a value obtained by titration.

  Next, the epoxy resin composition of the present invention will be described. The epoxy resin composition of this invention contains the epoxy resin of the said General formula (1), the at least 1 sort (s) of epoxy resin chosen from General formula (2)-(4), and a hardening | curing agent.

  Content of the epoxy resin represented by General formula (1) in an epoxy resin is 50 wt% or more, Preferably it is 60 wt% or more, More preferably, it is 70 wt% or more. If it is less than this, the thermal conductivity is not sufficiently developed.

  Further, the content of the epoxy resin represented by the general formulas (2) to (4) is 10 wt% to 50 wt% in the epoxy resin component, preferably 20 wt% to 40 wt%, more preferably 30 wt%. It is in the range of ˜40 wt%. If it is less than this, solvent solubility will fall, and if it is more than this, heat conductivity will not fully be expressed.

  The epoxy resin represented by the general formula (2) can be produced by reacting a paraformaldehyde or formalin solution with a phenolic hydroxyl group-containing compound to obtain a polyvalent hydroxy compound, followed by epoxidation.

  Moreover, in General formula (2), l is 1 or more, From a viewpoint of expression of high Tg property and a solvent solubility improvement, Preferably it is 2-10 as an average value (number average), More preferably, it is 2 The range is 5. Further, it is most preferable that 1 is 2 or 3 and 50 wt% or more is contained. If it is smaller than this, the Tg will decrease due to a decrease in the crosslinking density, and if it is higher than this, the solvent solubility may decrease due to an increase in molecular weight.

  Moreover, in General formula (3), m is 0 or more, and from a viewpoint of expression of high Tg property and a solvent solubility improvement, Preferably it is 0-5 as an average value (number average), More preferably, it is 0-0. 1 range. If it is larger than this, the solvent solubility may be lowered due to the increase in molecular weight.

  The epoxy resin represented by the general formula (3) can be produced by reacting salicylaldehyde or p-hydroxyaldehyde with a phenolic hydroxyl group-containing compound to obtain a polyvalent hydroxy compound, followed by epoxidation.

  Moreover, in General formula (4), m is 0 or more, From a viewpoint of expression of high Tg property and a solvent solubility improvement, Preferably it is 0-5 as an average value (number average), More preferably, it is 0-0. 1 range. If it is larger than this, the solvent solubility may be lowered due to the increase in molecular weight.

  The epoxy resin represented by the general formula (4) can be produced by reacting glyoxal with a phenolic hydroxyl group-containing compound to obtain a polyvalent hydroxy compound, followed by epoxidation.

  Here, as the phenolic hydroxyl group-containing compound used in the production of the epoxy resin represented by the general formulas (3) and (4), unsubstituted phenol is preferable from the viewpoint of thermal conductivity expression. A phenolic hydroxyl group-containing compound having a group may be included within a range that does not hinder a decrease in physical properties. Examples of the phenolic hydroxyl group-containing compound having a substituent include o-cresol, m-cresol, p-cresol, 2-ethylphenol, 4-ethylphenol, 2-propylphenol, 4-propylphenol, 4-tert-butylphenol, 4 -Pentylphenol, 4-tert-pentylphenol, 4-neopentylphenol, 2-cyclopentylphenol, 2-hexylphenol, 4-hexylphenol and the like.

  The epoxy resins represented by the general formulas (2) to (4) are preferably used alone and mixed with the epoxy resin of the general formula (1), but the general formulas (2) to (4) You may mix and use these 2-3 types in arbitrary ratios in the range which the sum total of an epoxy resin does not exceed 50 wt%. Among them, the epoxy resin of the general formula (2) is preferably used from the balance between the solvent solubility when mixed with the epoxy resin of the general formula (1) and the thermal conductivity of the cured product.

  The epoxy resin composition of the present invention contains the above epoxy resin and a phenolic curing agent as essential components. Advantageously, these and inorganic fillers are essential components.

  As the phenolic curing agent, polyhydric phenols are preferably used in a field where high electrical insulation properties such as a semiconductor sealing material are required. Below, the specific example of a hardening | curing agent is shown.

  Examples of polyhydric phenols include divalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, hydroquinone, resorcin, catechol, biphenols, naphthalenediols, and tris- (4-hydroxyphenyl). ) Trivalent or higher typified by methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak, naphthol novolak, dicyclopentadiene type phenol resin, phenol aralkyl resin, etc. Phenols, further phenols, naphthols, or bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroxyl Divalent phenols such as ethanol, resorcin, catechol, naphthalenediols, and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, p-xylylene glycol, p-xylylene glycol dimethyl ether, divinylbenzene, diisopropenylbenzene, dimethoxy Polyphenolic compounds synthesized by reaction with crosslinkers such as methyl biphenyls, divinyl biphenyls, diisopropenyl biphenyls, biphenyl aralkyl type phenol resins obtained from phenols and bischloromethyl biphenyls, naphthols and para Examples thereof include naphthol aralkyl resins synthesized from xylylene dichloride and the like.

  Other curing agent components can also be used, such as dicyandiamide, acid anhydrides, aromatic and aliphatic amines. In the epoxy resin composition of the present invention, one or more of these curing agents can be mixed and used. However, the phenolic curing agent is essential and is preferably 50 wt% or more of the curing agent.

  The amount of the curing agent is blended in consideration of an equivalent balance between the epoxy group in the epoxy resin and the functional group of the curing agent (a hydroxyl group in the case of polyhydric phenols). The equivalent ratio of epoxy resin and curing agent is usually in the range of 0.2 to 5.0, preferably in the range of 0.5 to 2.0, more preferably in the range of 0.8 to 1.5. It is. If it is larger or smaller than this, the curability of the epoxy resin composition is lowered, and the heat resistance, mechanical strength and the like of the cured product are lowered.

  Moreover, in this epoxy resin composition, you may mix | blend another kind of epoxy resin other than the epoxy resin represented by General formula (1)-(4) as an epoxy resin component. As other types of epoxy resins in this case, all ordinary epoxy resins having two or more epoxy groups in the molecule can be used. Examples include 2 such as bisphenol A, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, resorcin, naphthalenediols, etc. Epoxidized products of polyvalent phenols, epoxidized products of trivalent or higher phenols such as tris- (4-hydroxyphenyl) methane, o-cresol novolak, epoxidized products of cocondensation resins obtained from dicyclopentadiene and phenols, Epoxy products of cocondensation resins obtained from cresols, formaldehyde and alkoxy-substituted naphthalenes, epoxidation products of phenol aralkyl resins obtained from phenols and paraxylylene dichloride, bifes obtained from phenols and bischloromethylbiphenyl, etc. Ruararukiru type phenolic resin of epoxide, there is epoxidized naphthol aralkyl resin and the like which are synthesized from naphthols and para-xylylene dichloride and the like. These epoxy resins can be used alone or in combination of two or more. And the compounding quantity of another kind of epoxy resin in the whole epoxy resin is the range of 0-40 wt%, Preferably it is the range of 0-20 wt%.

  In addition to the above components, other additives can be added to the epoxy resin composition of the present invention.

  Furthermore, a crosslinked elastic body can be contained in the epoxy resin composition for the purpose of reducing the stress of the cured product. When a crosslinked elastic body is blended, it is possible to significantly reduce the occurrence of package cracks in a thermal shock test of a cured product.

  The content of the cross-linked elastic body is preferably in the range of 3 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin, preferably 5 to 20 parts by weight, and more preferably 5 to 15 parts by weight. If it is smaller than this, low elasticity is not sufficiently exhibited. On the other hand, if it is larger than this, the Tg of the cured product is lowered, the fluidity is lowered, and the moldability tends to be inferior.

  As the cross-linked elastic body, known materials can be used, but from the viewpoint of improving compatibility with the epoxy resin, it is preferable to use styrene rubber or acrylic rubber.

  When an inorganic filler is blended in the epoxy resin composition, examples of the inorganic filler include silica powder such as spherical or crushed fused silica and crystalline silica, alumina powder, glass powder, mica, talc, and calcium carbonate. , Alumina, hydrated alumina, and the like, and a preferable blending amount when used for a semiconductor encapsulant is 70% by weight or more, and more preferably 80% by weight or more. Although there is no restriction | limiting in the shape of an inorganic filler, A spherical shape, a crushing shape, a flat shape, a fiber shape, etc. can be used, The range of 1-1000 micrometers is preferable for the particle size or major axis. When the prepreg is used, the fiber length of the fibrous base material is preferably 10 mm or more, and the amount of the inorganic filler blended therein is preferably in the range of 10 to 90% by weight.

  For the purpose of imparting higher thermal conductivity, the inorganic filler is preferably as high as possible. It is preferably 20 W / m · K or more, more preferably 30 W / m · K or more, and still more preferably 50 W / m · K or more. At least a part of the inorganic filler, preferably 50 wt% or more, has a thermal conductivity of 20 W / m · K or more. The average thermal conductivity of the inorganic filler as a whole is improved in the order of 20 W / m · K or higher, 30 W / m · K or higher, and 50 W / m · K or higher.

  Examples of inorganic fillers having such thermal conductivity include inorganic powder fillers such as boron nitride, aluminum nitride, silicon nitride, silicon carbide, titanium nitride, zinc oxide, tungsten carbide, alumina, and magnesium oxide. It is done.

  In the epoxy resin composition of the present invention, an oligomer or a polymer compound such as polyester, polyamide, polyimide, polyether, polyurethane, petroleum resin, indene resin, indene-coumarone resin, phenoxy resin, etc. is used as another modifier. You may mix | blend suitably. The addition amount is usually in the range of 2 to 30 parts by weight with respect to 100 parts by weight of the epoxy resin.

  The epoxy resin composition of the present invention may contain additives such as pigments, refractory agents, thixotropic agents, coupling agents, fluidity improvers and the like.

  Examples of the pigment include organic or inorganic extender pigments and scaly pigments. Examples of the thixotropic agent include silicon-based, castor oil-based, aliphatic amide wax, polyethylene oxide wax, and organic bentonite.

  Furthermore, a curing accelerator can be used in the epoxy resin composition of the present invention as necessary. Examples include amines, imidazoles, organic phosphines, Lewis acids, etc., specifically 1,8-diazabicyclo (5,4,0) undecene-7, triethylenediamine, benzyldimethylamine, Tertiary amines such as ethanolamine, dimethylaminoethanol, tris (dimethylaminomethyl) phenol, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methylimidazole, 2- Imidazoles such as heptadecylimidazole, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine, tetraphenylphosphonium tetraphenylborate, tetraphenyl Tetraphenyl such as ruphosphonium / ethyltriphenylborate, tetrabutylphosphonium / tetrabutylborate, tetrasubstituted phosphonium / tetrasubstituted borate, 2-ethyl-4-methylimidazole / tetraphenylborate, N-methylmorpholine / tetraphenylborate, etc. There is boron salt. As addition amount, it is the range of 0.2-5 weight part normally with respect to 100 weight part of epoxy resins.

  Further, if necessary, the resin composition of the present invention includes a release agent such as carnauba wax and OP wax, a coupling agent such as γ-glycidoxypropyltrimethoxysilane, a colorant such as carbon black, and trioxide. Flame retardants such as antimony and lubricants such as calcium stearate can be used.

  The epoxy resin composition of the present invention can be advantageously used as a varnish state (referred to as varnish) in which a part or all of the epoxy resin composition is dissolved in an organic solvent. When a solvent-insoluble component such as an inorganic filler is included, it is not necessary to dissolve it, but it is desirable to make it a suspended state to obtain a uniform solution. The epoxy resin in the resin composition is desirably completely dissolved, but the epoxy resin of the present invention has the characteristics that the solubility is excellent and the solid content hardly precipitates in the storage state. If a part of the epoxy resin in the varnish becomes a solid and separates, the properties of the cured product are inferior.

  The epoxy resin composition of the present invention is preferably a fibrous base material such as a glass cloth, an aramid nonwoven fabric, a liquid crystal polymer polyester nonwoven fabric, etc. after a resin component is dissolved in a solvent (varnish). By removing the solvent after impregnating, the prepreg in which the epoxy resin composition and the fibrous base material are combined can be obtained. Moreover, it can be set as a laminated body by apply | coating the said varnish on sheet-like objects, such as copper foil, stainless steel foil, a polyimide film, and a polyester film depending on the case. Moreover, it can be set as a laminated body also by laminating | stacking a plurality of said prepregs, and laminating | stacking a prepreg and the said sheet-like material.

  If the epoxy resin composition of the present invention is cured by heating, an epoxy resin cured product can be obtained, and this cured product is excellent in terms of low hygroscopicity, high heat resistance, adhesion, flame retardancy, and the like. Become. This cured product can be obtained by molding the epoxy resin composition by a method such as casting, compression molding, transfer molding or the like. The temperature at this time is usually in the range of 120 to 220 ° C.

  Hereinafter, based on a synthesis example, an Example, and a comparative example, this invention is demonstrated concretely.

Synthesis example 1
In a 2 L 4-neck flask, 186 g (1.0 mol) of 4,4′-dihydroxybiphenyl, 69 g (0.5 mol) of p-xylylene glycol, 743 g of diethylene glycol dimethyl ether as a solvent, p-toluenesulfonic acid 2 as an acid catalyst .55 g was charged and the temperature was raised to 160 ° C. Next, it was made to react for 3 hours, stirring at 160 degreeC. Next, a part of the solvent was distilled off under reduced pressure. Into 237 g of the obtained resin, 740 g of epichlorohydrin was charged and dissolved. Subsequently, 150.8 g of a 49% aqueous sodium hydroxide solution was added dropwise at 75 ° C. under reduced pressure over 4 hours, and water and epichlorohydrin distilled under reflux during the dropping were separated in a separation tank, and epichlorohydrin was returned to the reaction vessel. Water reacted outside the system. After completion of the reaction, the salt produced by filtration was removed, and after further washing with water, epichlorohydrin was distilled off to obtain 279 g of an epoxy resin (epoxy resin A). The epoxy equivalent of the obtained resin was 185 g / eq. Met. The peak temperature (melting point) in DSC measurement was 125 ° C., and the melt viscosity at 150 ° C. was 0.48 Pa · s.

Synthesis example 2
In a 1000 ml four-necked flask, 77.5 g of 4,4′-dihydroxybiphenyl, 180.8 g of diethylene glycol dimethyl ether, and 52.3 g of 4,4′-bischloromethylbiphenyl were charged, and the temperature was raised to 170 ° C. with stirring in a nitrogen stream. The reaction was allowed to warm for 2 hours. After the reaction, 123 g of diethylene glycol dimethyl ether was recovered, dissolved in 385.4 g of epichlorohydrin and 57.8 g of diethylene glycol dimethyl ether, and 69.4 g of 48% aqueous sodium hydroxide solution was added dropwise at 62 ° C. under reduced pressure (about 130 Torr) over 4 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 completion of the dropwise addition, the reaction was continued for another hour. Thereafter, epichlorohydrin was distilled off, methyl isobutyl ketone was added, salts were removed by washing with water, filtration and washing were performed, and then methyl isobutyl ketone as a solvent was distilled off under reduced pressure to obtain 129 g of an epoxy resin. (Epoxy resin B). The epoxy equivalent of the obtained resin was 196 g / eq. Met. The peak temperature (melting point) in DSC measurement was 126 ° C., and the melt viscosity at 150 ° C. was 0.68 Pa · s.

Examples 1-7, Comparative Examples 1-4
An epoxy resin composition shown in Table 1 was prepared, and a resin solution in which the resin solubility of this resin composition was dissolved using cyclopentanone as a solvent and a solid content concentration of 30 wt% was obtained. The solution stability was evaluated based on the number of days (hours) until the precipitate was confirmed after standing at room temperature. The results are shown in Table 1. Examples 1 and 3 to 7 showed stability for 7 days or more, but Comparative Examples 3 and 4 were as short as 3 hours and 6 hours. Note that the ratio 1 means Comparative Example 1, and the same applies to the ratio 2 and later.

The abbreviations in the table are explained as follows.
(Epoxy resin)
Epoxy resin A; Epoxy resin obtained in Synthesis Example 1 Epoxy resin B; Epoxy resin obtained in Synthesis Example 2 Epoxy resin C; Epoxy resin represented by the general formula (2) (epoxy equivalent 175 g / eq., The content of l = 1 component by GPC measurement is 9.0%, l = 2 component; 37.7%, l = 3 component; 17.1%, l = 4 component; 8.2%, and l = 5 (The total content of the components or more is 27.9%.)
Epoxy resin D: epoxy resin represented by general formula (2) (epoxy equivalent 177 g / eq., 1 = 1 component content by GPC measurement is 21.9%, l = 2 component; 14.7%, (1 = 3 component; 10.4%, l = 4 component; 8.1%, and the total content of 1 = 5 component or more is 44.9%.)
Epoxy resin E; epoxy resin represented by the general formula (3) (EPPN-501H (manufactured by Nippon Kayaku) epoxy equivalent 168 g / eq.)
Epoxy resin F: epoxy resin represented by the general formula (4) (epoxy equivalent 173 g / eq.)
Epoxy resin G; bisphenol A type epoxy resin (YD-128 (manufactured by Nippon Steel & Sumikin Chemical) epoxy equivalent 188 g / eq.)
Epoxy resin H; o-cresol novolac type epoxy resin (YDCN-700-3 (manufactured by Nippon Steel & Sumikin Chemical) epoxy equivalent 200 g / eq.)

(Curing agent)
Curing agent A: phenol novolac type polyvalent hydroxy resin (PSM-4261 (manufactured by Gunei Chemical Industry Co., Ltd.), OH equivalent 103, softening point 82 ° C.)
Curing agent B: Triphenolmethane type polyvalent hydroxy resin (TPM-100 (manufactured by Gunei Chemical Industry Co., Ltd.), OH equivalent 97.5, softening point 105 ° C.)
(Curing catalyst)
Curing catalyst A: triphenylphosphine (product name: TPP, manufactured by Hokuko Chemical Co., Ltd.)
(Inorganic filler)
Spherical alumina (Product name: DAW-100, manufactured by Denki Kagaku Kogyo Co., Ltd., thermal conductivity 38 W / m · K)
(Release agent)
・ Carnauba wax (Product name: TOWAX171, manufactured by Toa Kasei Co., Ltd.)
(Coloring agent)
・ Carbon black (Product name: MA-100, manufactured by Mitsubishi Chemical Corporation)

Examples 8-14, Comparative Examples 5-8
Epoxy resin compositions were prepared with the formulations (parts by weight) shown in Tables 2-3. This epoxy resin composition was molded at 175 ° C., and further post-cured at 175 ° C. for 12 hours to obtain a cured product test piece, which was then subjected to various physical property measurements. The results are shown in Tables 2-3.

Test conditions for the epoxy resin, the epoxy resin composition and the cured product are shown below.
1) Gel permeation chromatography (GPC) measurement Tosoh Corporation TSKgelG4000HXL, TSKgelG3000HXL, TSKgelG2000HXL were used in series, and the column temperature was 40 ° C. Tetrahydrofuran was used as the eluent, the flow rate was 1 ml / min, and an RI (differential refractometer) detector was used as the detector.
2) Measurement of epoxy equivalent Using a potentiometric titrator, methyl ethyl ketone was used as a solvent, a brominated tetraethylammonium acetic acid solution was added, and a 0.1 mol / L perchloric acid-acetic acid solution was measured with a potentiometric titrator.

3) Melting | fusing point DSC peak temperature was calculated | required on the conditions of the temperature increase rate of 5 degree-C / min with the differential scanning calorimetry apparatus (SII nanotechnology Co., Ltd. EXSTAR6000 DSC / 6200). That is, this DSC peak temperature was taken as the melting point of the epoxy resin.

4) Melt viscosity Measured at 150 ° C. using a CAP2000H type rotational viscometer manufactured by BROOKFIELD.

5) Gel time (seconds)
According to JISK6910, it measured at 175 degreeC.

6) Glass transition point (Tg)
Tg was calculated | required on the conditions of the temperature increase rate of 10 degree-C / min with the thermomechanical measuring apparatus (SII nanotechnology Co., Ltd. product EXSTAR6000TMA / 6100).

7) Thermal conductivity Thermal conductivity was measured by the unsteady hot wire method using an LFA447 type thermal conductivity meter manufactured by NETZSCH.

8) Insulation (volume resistivity)
The volume resistivity was measured according to JIS-K-6911 using a volume resistivity measuring device (manufactured by ADVANTEST, R8340 ULTRA HIGH RESISTANCE METER).

Claims (3)

It is an epoxy resin composition containing an epoxy resin and a phenolic curing agent, and the epoxy resin is represented by the following general formula (1) with 50 wt% or more of the epoxy resin represented by the general formulas (2) to (4). An epoxy resin composition comprising 10 wt% or more of any of the represented epoxy resins.

(However, k shows 0.2-4.0 as an average value, t shows the number of 1 or 2, and G shows a glycidyl group.)

(However, l represents a number of 1 or more, and G represents a glycidyl group.)

(However, m represents a number of 0 or more, and G represents a glycidyl group.)

(However, n represents a number of 0 or more, and G represents a glycidyl group.)
  The epoxy resin composition according to claim 1, further comprising an inorganic filler.   An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 1.