JP5079721B2 - Epoxy resin composition and molded article - Google Patents

Description

  The present invention relates to an epoxy resin composition useful as an insulating material for electrical / electronic materials such as semiconductor sealing, laminated board, heat dissipation board and the like having excellent reliability, and a molded article using the same.

  Conventionally, as a sealing method for electrical and electronic parts such as diodes, transistors, and integrated circuits, and semiconductor devices, for example, a sealing method using an epoxy resin or a silicon resin, or a hermetic sealing method using glass, metal, ceramic, or the like In recent years, resin sealing by transfer molding, which can be mass-produced with improved reliability and cost-effective, has been the mainstream in recent years.

  In a resin composition used for resin sealing by transfer molding, a sealing material composed of an epoxy resin and a resin composition mainly composed of a phenol resin as a curing agent is generally used.

  Epoxy resin compositions used for the purpose of protecting elements such as power devices are filled with an inorganic filler such as crystalline silica at a high density in order to cope with a large amount of heat released from the element.

  Power devices include one-chip devices incorporating IC technology and modularized devices, and further improvements in heat dissipation, heat resistance, and thermal expansion for sealing materials are desired. Yes.

  In order to meet these demands, attempts have been made to include inorganic fillers such as crystalline silica, silicon nitride, aluminum nitride, and spherical alumina powder having high thermal conductivity in order to improve thermal conductivity (patents). As Documents 1 and 2) increase the content of the inorganic filler, there is a problem in that the fluidity decreases with increasing viscosity during molding, and the moldability is impaired. Therefore, there is a limit to the method of simply increasing the content of the inorganic filler.

  From the above background, a method for improving the thermal conductivity of the composition by increasing the thermal conductivity of the matrix resin itself has been studied. For example, Patent Literature 3, Patent Literature 4 and Patent Literature 5 propose a liquid crystalline epoxy resin having a rigid mesogenic group and an epoxy resin composition using the same. However, an aromatic diamine compound is used as the curing agent used in these epoxy resin compositions, and there is a limit in increasing the filling rate of the inorganic filler, and there is also a problem in terms of electrical insulation. Further, when an aromatic diamine compound is used, the liquid crystallinity of the cured product can be confirmed, but the crystallinity of the cured product is low, which is not sufficient in terms of high thermal conductivity, low thermal expansion, low hygroscopicity, and the like. Furthermore, in order to exhibit liquid crystallinity, it is necessary to orient the molecules by applying a strong magnetic field, and there are significant restrictions in terms of equipment for wide industrial use. In addition, in the compounding system with the inorganic filler, the thermal conductivity of the inorganic filler is overwhelmingly larger than that of the matrix resin, and even if the thermal conductivity of the matrix resin itself is increased, There is a reality that it does not greatly contribute to the improvement of thermal conductivity, and a sufficient effect of improving thermal conductivity has not been obtained. Non-Patent Document 1 discloses an epoxy resin having an etheretherketone group and discloses physical properties of an epoxy cured product obtained by using a diamine compound as a curing agent. There is no teaching about the physical properties of the cured product obtained from the functional phenol curing agent.

JP-A-11-147936 JP 2002-309067 A JP-A-11-323162 JP-A-2004-331811 JP-A-9-118673

K.S.Lee, et.al., Bull. Korean Chem. Soc. 2001, 22, 424

  Therefore, the object of the present invention is to eliminate the above-mentioned problems, to obtain a molded article having excellent moldability, high thermal conductivity when combined with an inorganic filler, low thermal expansion, and excellent moisture resistance. An epoxy resin composition is provided, and a molded article using the composition is further provided.

  When the present inventors combine an epoxy resin having an ether ether ketone group and a specific bifunctional curing agent in which the reaction proceeds two-dimensionally, physical properties such as thermal conductivity, heat resistance, and low thermal expansion are obtained. The inventors have found that it can be improved specifically, and have reached the present invention.

  The present invention relates to an epoxy resin and a curing agent, or an epoxy resin composition mainly composed of these and an inorganic filler, wherein 50 wt% or more of the epoxy resin has an ether ether ketone group represented by the following formula (1). An epoxy resin composition characterized in that it is a resin and 50 wt% or more of the curing agent is a bifunctional phenolic compound.

（但し、Ａは１，４−フェニレン基、１，３−フェニレン基、４，４’−ビフェニレン基、４，４’−ジフェニルエーテル基、４，４’−ジフェニルケトン基、４，４’−ジフェニルメタン基、４，４’−ジフェニルスルフィド基またはナフチレン基より選ばれた二価の芳香族基であり、ｍは１〜１０、ｎは０〜５０の数を示す。）

(However, A is 1,4-phenylene group, 1,3-phenylene group, 4,4′-biphenylene group, 4,4′-diphenyl ether group, 4,4′-diphenyl ketone group, 4,4′-diphenylmethane. A divalent aromatic group selected from a group, 4,4′-diphenyl sulfide group or naphthylene group, m is 1 to 10, and n is a number from 0 to 50.)

  Examples of the bifunctional phenolic compound include hydroquinone, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl ketone, 1,4-bis (4-hydroxyphenoxy) benzene, Preference is given to at least one bifunctional phenolic compound selected from the group consisting of dihydroxydiphenylmethanes, 4,4′-dihydroxydiphenyl sulfide or naphthalenediols.

  The epoxy resin composition of the present invention can contain an inorganic filler. In this case, the epoxy resin composition preferably contains 50 to 96 wt% of the inorganic filler. As the inorganic filler, spherical alumina is preferably exemplified, and the amount used is preferably 50 wt% or more of the inorganic filler.

  The epoxy resin composition of the present invention is suitable as an epoxy resin composition for an electronic material such as a sealing material or an insulating substrate.

  Furthermore, the present invention is a molded product obtained by reacting the above epoxy resin composition and molding and curing it. This molded article preferably has a thermal conductivity of 4 W / m · K or more.

  The epoxy resin composition of the present invention provides a molded product excellent in moldability and reliability, and excellent in high thermal conductivity, low water absorption, and low thermal expansibility. It is suitably applied as an insulating material for electronic materials and exhibits excellent high heat dissipation and high dimensional stability. The reason why such a specific effect occurs is that the orientation of the resin skeleton is improved by using a rigid structure of the ether ether ketone group and a phenolic compound, especially a bifunctional phenolic compound as a curing agent. Inferred.

  Hereinafter, the present invention will be described in detail.

  The epoxy resin used for the epoxy resin composition of the present invention contains 50 wt% or more of an epoxy resin having an ether ether ketone group represented by the above formula (1).

In the formula (1), —A— is a divalent aromatic group represented by —Ar ₁ — or —Ar ₂ —X—Ar ₃ —. Here, Ar ₁ is a phenylene group or a naphthylene group, Ar ₂ and Ar ₃ are phenylene groups, and X is a direct bond, O, CO, CH ₂ or S. Specifically, 1,4-phenylene group, 1,3-phenylene group, 4,4′-biphenylene group, 4,4′-diphenyl ether group, 4,4′-diphenyl ketone group, 4,4′-diphenylmethane A divalent aromatic group selected from a group, 4,4′-diphenyl sulfide group and naphthylene group, preferably 1,4-phenylene group or 1,3-phenylene group.

  Although m represents the number of 1-10, the preferable value of m changes according to the application to apply. For example, for the use of a semiconductor encapsulant that requires a high filling rate of the filler, a material having a low viscosity is desirable, and the average value of m is in the range of 1 to 3, preferably 1.1 to 2. . More preferably, 80% by weight or more of m is included.

  n represents a number from 0 to 50, but a preferable value of n varies depending on the application. For example, for a semiconductor encapsulant that requires a high filling factor of filler, one having a low viscosity is desirable, and n is in the range of 0 to 5, preferably 0 to 2. When the epoxy resin is a mixture having different values of n, the number average value of n is preferably from 0 to 5, and preferably from 0.1 to 2. More preferably, those having n of 0 are contained in an amount of 50 wt% or more, and the number average value of n is 0.1 to 1. These low molecular weight epoxy resins are optionally crystallized and used as a solid at room temperature. Moreover, a high molecular weight epoxy resin is used suitably for uses, such as a printed wiring board, The value of n in this case is 5-50, Preferably it is 10-40, More preferably, it is 20-40. In the case of a mixture in which the value of n is different, the above range is also good as the number average value of n. In this case, as long as the number average value is 50 or less, a molecule in which the value of n is an integer of 50 or more may be included.

  Although the manufacturing method of the epoxy resin used for this invention is not specifically limited, It can manufacture by making the phenolic compound which has the ether ether ketone group represented by following formula (2), and epichlorohydrin react. This reaction can be performed in the same manner as a normal epoxidation reaction.

  In the general formula (2), A has the same meaning as A in the general formula (1), and is preferably a 1,4-phenylene group or a 1,3-phenylene group. m also has the same meaning as m in the general formula (1). When this phenolic compound is used as a raw material for an epoxy resin, it may be a single compound or a mixture of multimers that are compounds having different values of m.

  The reaction between the phenolic compound and epichlorohydrin is, for example, after dissolving the phenolic compound in excess epichlorohydrin and then in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, preferably at 50 to 150 ° C., preferably The method of making it react for 1 to 10 hours in the range of 60-100 degreeC is mentioned. In this case, the amount of the alkali metal hydroxide used is in the range of 0.8 to 2.0 mol, preferably 0.9 to 1.5 mol, with respect to 1 mol of the hydroxyl group in the dihydroxy body. Epichlorohydrin is used in an excess amount with respect to the hydroxyl group in the phenolic compound, and is usually 1.5 to 15 mol with respect to 1 mol of the hydroxyl group in the phenolic compound. By changing the use ratio of epichlorohydrin to the phenolic compound, n in the general formula (1) can be controlled. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the target epoxy is removed by distilling off the solvent. A resin can be obtained.

  The epoxy resin used in the epoxy resin composition of the present invention can also be synthesized using a mixture of a phenolic compound having an ether ether ketone group and another phenolic compound not having an ether ether ketone group. In this case, the mixing ratio of the phenolic compound having an ether ether ketone group is 50 wt% or more. Other phenolic compounds are not particularly limited and are selected from those having two or more hydroxyl groups in one molecule.

  The epoxy equivalent of the epoxy resin used in the epoxy resin composition of the present invention is usually in the range of 250 to 600. However, from the viewpoint of increasing the filling rate of inorganic filler and improving fluidity, it is preferable that the epoxy resin has a low viscosity. Those having an equivalent weight in the range of 250 to 400 are preferred.

  As the epoxy resin having an ether ether ketone group, those having crystallinity at normal temperature are preferably used. The range of preferable melting | fusing point is 70 to 250 degreeC, More preferably, it is the range of 100 to 200 degreeC. If it is lower than this, blocking and the like are likely to occur, resulting in poor handling as a solid, and if it is higher than this, compatibility with a curing agent or the like, solubility in a solvent, and the like are reduced.

The purity of the epoxy resin or the epoxy resin having an ether ether ketone group, particularly the amount of hydrolyzable chlorine used in the epoxy resin composition of the present invention is preferably smaller than 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, hydrolyzable chlorine as used in this specification means the value measured by the following method. That is, the potential difference the sample 0.5g were dissolved in dioxane 30 ml, 1N-KOH, after the added boiled under reflux for 30 minutes 10 ml, cooled to room temperature, 80% aqueous acetone 100ml was added, with 0.002 N-AgNO ₃ aqueous solution This is a value obtained by titration.

  In addition to the epoxy resin having an ether ether ketone group used as an essential component, the epoxy resin composition of the present invention may be used in combination with another epoxy resin having two or more epoxy groups in the molecule as an epoxy resin component. Good. Examples include bisphenol A, bisphenol F, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenylsulfone, 4,4′-dihydroxydiphenyl sulfide, Divalent phenols such as fluorene bisphenol, 2,2'-biphenol, resorcin, catechol, t-butylcatechol, t-butylhydroquinone, allylated bisphenol A, allylated bisphenol F, allylated phenol novolak, or phenol novolak Bisphenol A novolak, o-cresol novolak, m-cresol novolak, p-cresol novolak, xylenol novolak, poly-p-hydroxystyrene, tris- (4-hydroxyphenyl) meta 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, fluoroglycinol, pyrogallol, t-butyl pyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3, There are glycidyl ethers derived from 4-trihydroxybenzophenone, phenol aralkyl resins, naphthol aralkyl resins, trivalent or higher phenols such as dicyclopentadiene resins, or halogenated bisphenols such as tetrabromobisphenol A . These epoxy resins can be used alone or in combination of two or more. Moreover, as another epoxy resin, the epoxy resin which has a mesogen group can be used preferably, and these can use 1 type (s) or 2 or more types.

  The compounding ratio of the epoxy resin having an ether ether ketone group used in the epoxy resin composition of the present invention is 50 wt% or more, preferably 70 wt% or more, more preferably 90 wt% or more of the total epoxy resin. Furthermore, it is desirable that the total amount of the bifunctional epoxy resin is 90 wt% or more, preferably 95 wt% or more. If it is less than this, the effect of improving physical properties such as thermal conductivity when cured is small. This is because the higher the content of the epoxy resin having an ether ether ketone group and the higher the content of the bifunctional epoxy resin, the higher the degree of orientation as a molded product.

（但し、Ｚは単結合、メチレン基、酸素原子または硫黄原子、ｒは０または１を示す。） As an epoxy resin other than an epoxy resin having an ether ether ketone group, a bisphenol-based epoxy resin represented by the following general formula (3) is preferable.

(However, Z represents a single bond, a methylene group, an oxygen atom or a sulfur atom, and r represents 0 or 1.)

  These epoxy resins are synthesized, for example, by performing a normal epoxidation reaction using hydroquinone, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, or 4,4′-dihydroxydiphenyl sulfide as a raw material. be able to. These epoxy resins may be synthesized alone or in combination with any of these dihydroxy compounds at the raw material stage, or may be synthesized using a mixture of other dihydroxy compounds other than these. May be.

  The bifunctional phenolic compound used as the curing agent has two phenolic hydroxyl groups in one molecule and is not particularly limited. For example, bisphenol A, bisphenol F, 4,4′-dihydroxy Diphenylmethane, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) benzene, 1,3-bis (4-hydroxyphenoxy) benzene, 4,4′-dihydroxydiphenyl sulfide, 4,4′- Dihydroxydiphenyl ketone, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 10- (2,5-dihydroxyphenyl) -10H-9-oxa-10-phospha Phenanthrene-10-oxide, hydroxy , Resorcin, 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, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, and bisphenol compounds having an ether ether ketone group of the above formula (2) Can do. Two or more of these may be used.

As a preferable bifunctional phenolic compound, there is a bifunctional phenolic compound represented by the following general formula.
HO-Ar ₄ -OH or HO-Ar ₅ -Y-Ar ₅ -OH
Here, Ar ₄ is preferably a phenylene group or a naphthylene group, more preferably a 1,4-phenylene group. Ar ₅ is preferably a phenylene group, more preferably a 1,4-phenylene group. Y is preferably a single bond, CH ₂ , O, a phenylene group, S, CO, or SO ₂ .

  As the bifunctional phenolic compound used as a curing agent, those having a mesogenic group are preferably used. Specifically, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ketone, 1,5-naphthalenediol 2,6-naphthalenediol, 2,7-naphthalenediol, and bisphenol compounds having the ether ether ketone group of the above formula (2). In addition, those having no mesogenic group and preferred bifunctional phenolic compounds include hydroquinone, resorcin, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, 1,4-bis (4-hydroxyphenoxy) Mention may be made of benzene and 4,4′-dihydroxydiphenyl sulfide.

  The amount of the bifunctional phenolic compound used as the curing agent is 50 wt% or more of the total curing agent, preferably 70 wt% or more, more preferably 80 wt% or more. If it is less than this, the effect of improving physical properties such as thermal conductivity when cured is small. This is because the higher the content of the bifunctional phenolic compound, the higher the degree of orientation as a molded product.

  As a hardening | curing agent used with the epoxy resin composition of this invention, the other hardening agent generally known as a hardening | curing agent other than said bifunctional phenolic compound can be used in combination. Examples include amine curing agents, acid anhydride curing agents, phenolic curing agents, polymercaptan curing agents, polyaminoamide curing agents, isocyanate curing agents, block isocyanate curing agents, and the like. What is necessary is just to set the compounding quantity of these other hardening | curing agents suitably considering the kind of hardening | curing agent to mix | blend and the physical property of the heat conductive epoxy resin molded object obtained. However, it does not exceed 50 wt% of the total curing agent.

  In the epoxy resin composition of the present invention, the mixing ratio of the epoxy resin and the curing agent is preferably in the range of 0.8 to 1.5 in terms of an equivalent ratio of the epoxy group and the functional group in the curing agent. Outside this range, unreacted epoxy groups or functional groups in the curing agent remain after curing, and the reliability of the insulating material for electronic parts is lowered.

  The epoxy resin composition of the present invention preferably contains an inorganic filler. In this case, the amount of the inorganic filler added is usually 50 to 96 wt% with respect to the epoxy resin composition, preferably 75 to 96 wt%, and more preferably 85 to 96 wt%. If it is less than this, effects such as high thermal conductivity, low thermal expansion, high heat resistance and flame retardancy will not be sufficiently exhibited. These effects are improved as the added amount of the inorganic filler is increased, but are not improved in accordance with the volume fraction, and are drastically improved from the point when the added amount exceeds the specific amount. These physical properties are due to the effect of controlling the higher order structure in the polymer state, and since this higher order structure is achieved mainly on the surface of the inorganic filler, a specific amount of inorganic filler is required. It is thought to be. On the other hand, when the added amount of the inorganic filler is larger than this, the viscosity is increased and the moldability is deteriorated.

  In the case of blending an inorganic filler, the inorganic filler is preferably spherical, and is not particularly limited as long as it has a spherical shape including those having a cross section on an ellipse. It is particularly preferable that the shape is close to a true sphere. Thereby, it is easy to take a close-packed structure such as a face-centered cubic structure or a hexagonal close-packed structure, and a sufficient filling amount can be obtained. If it is not spherical, if the filling amount increases, the friction between the fillers increases, and before reaching the above upper limit, the fluidity is extremely lowered, the viscosity becomes high, and the moldability deteriorates, so the filling amount may be suppressed. There is.

  From the viewpoint of improving thermal conductivity, it is preferable that 50 wt% or more, preferably 80 wt% or more of the inorganic filler has a thermal conductivity of 5 W / m · K or more. As such an inorganic filler, alumina, aluminum nitride, crystalline silica and the like are suitable. Among these, spherical alumina is excellent. In addition, an amorphous inorganic filler such as fused silica or crystalline silica may be used in combination, if necessary, regardless of the shape.

  Moreover, it is preferable that the average particle diameter of an inorganic filler is 30 micrometers or less. If the average particle size is larger than this, the fluidity of the epoxy resin composition is impaired, and the strength is also lowered.

  A conventionally well-known hardening accelerator can be used for the epoxy resin composition of this invention. 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, imidazoles such as 2-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole, Organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, phenylphosphine, tetraphenylphosphonium / tetraphenylborate, tetraphenylphosphonium / ethyltriphenyl Rate, tetra-substituted phosphonium tetra-substituted borate such as tetrabutylphosphonium-tetrabutyl borate, 2-ethyl-4-methylimidazole · tetraphenyl port rate, and the like tetraphenyl boron salts such as N- methylmorpholine-tetraphenyl port rate. These may be used alone or in combination.

  As for the addition amount of the said hardening accelerator, 0.1-10.0 wt% is preferable with respect to the sum total of an epoxy resin and a hardening | curing agent. If it is less than 0.1 wt%, the gelation time will be delayed, resulting in a decrease in workability due to a decrease in rigidity during the heating reaction. Conversely, if it exceeds 10.0 wt%, the reaction will progress during the molding and unfilling will occur. It becomes easy.

  In the epoxy resin composition of the present invention, in addition to the above components, a mold release agent, a coupling agent, a thermoplastic oligomer, and other components that can be generally used for an epoxy resin composition are appropriately blended and used. be able to. For example, phosphorus-based flame retardants, flame retardants such as bromine compounds and antimony trioxide, and colorants such as carbon black and organic dyes can be used.

  Wax can be used as the release agent. As the wax, for example, stearic acid, montanic acid, montanic acid ester, phosphoric acid ester and the like can be used.

  As the coupling agent, for example, epoxy silane can be used. The addition amount of the coupling agent is preferably 0.1 to 2.0 wt% with respect to the epoxy resin composition. If it is less than 0.1 wt%, the resin and the base material will not be well-matched, and the moldability will be poor. Conversely, if it exceeds 2.0 wt%, the molded product will become dirty with continuous moldability. The coupling agent is used to improve the adhesion between the inorganic filler and the resin component.

  Thermoplastic oligomers include C5 and C9 petroleum resins, styrene resins, indene resins, indene / styrene copolymer resins, indene / styrene / phenol copolymer resins, indene / coumarone copolymer resins, indene / benzothiophene. Examples thereof include copolymer resins. As addition amount, it is the range of 2-30 weight part normally with respect to 100 weight part of epoxy resins. Thermoplastic oligomers are used to improve fluidity during molding of the epoxy resin composition and to improve adhesion to a substrate such as a lead frame.

  The epoxy resin composition of the present invention comprises an epoxy resin and a curing agent as essential components, and a blending component (excluding a coupling agent) containing components such as an inorganic filler is uniformly mixed by a mixer or the like, and then a coupling agent. And knead | mixing with a heating roll, a kneader, etc. can manufacture. There is no restriction | limiting in particular in the mixing | blending order of these components except a coupling agent. Further, after kneading, the melt-kneaded material can be pulverized to be powdered or tableted.

  The epoxy resin composition of the present invention is particularly suitable as an epoxy resin composition for electronic materials because it is excellent for electronic component sealing and heat dissipation substrates.

  The epoxy resin composition of the present invention can be combined with a fibrous base material such as glass fiber to form a composite material. For example, a sheet fiber base material impregnated with an epoxy resin composition mainly composed of an epoxy resin and a curing agent in an organic solvent is impregnated and dried by heating to partially react the epoxy resin to obtain a prepreg. be able to.

  In order to obtain a molded product using the epoxy resin composition of the present invention, for example, a heat molding method such as transfer molding, press molding, cast molding, injection molding, extrusion molding or the like is applied. From the above, transfer molding is preferred. By thermoforming, curing and molding are performed to obtain a cured molded product. Here, curing means that the reaction between the epoxy resin and the curing agent proceeds sufficiently.

  Even when the epoxy resin composition of the present invention is composed only of a bifunctional epoxy resin and a curing agent, when the epoxy resin and the curing agent are heated and reacted, the epoxy resin and the curing agent react with each other. Since this part further reacts with the epoxy group in the epoxy resin, it usually gives a three-dimensional cured product, but in some cases, by use of an organic solvent, selection of a curing accelerator type, and control of heating reaction conditions such as reaction temperature, It can be set as the thermoplastic molding substantially comprised only by the two-dimensional polymer.

  The cured molded product of the present invention preferably has crystallinity from the viewpoints of high heat resistance, low thermal expansion and high thermal conductivity. The expression of the crystallinity of the molded product can be confirmed by observing an endothermic peak accompanying melting of the crystal as a melting point by scanning differential thermal analysis. A preferred melting point is in the range of 120 ° C. to 280 ° C., more preferably in the range of 150 ° C. to 250 ° C. Moreover, the preferable thermal conductivity of the cured molded product is 4 W / m · K or more, and particularly preferably 6 W / m · K or more.

  Here, the effect of crystallinity will be briefly described. Generally, in a cured epoxy resin, a glass transition point is used as an index of heat resistance. This is because a normal epoxy resin cured product is an amorphous (glassy) molded product having no crystallinity, and the physical properties greatly change at the glass transition point. Therefore, in order to increase the heat resistance of the cured epoxy resin, that is, to increase the glass transition point, it is necessary to increase the crosslink density. On the other hand, the cured molded product of the present invention is characterized in that crystallinity is developed, but since the change in physical properties is small up to the melting point, the melting point can be used as an index of heat resistance. Since the polymer material has a melting point higher than the glass transition point, the cured molded product of the present invention can ensure high heat resistance while maintaining high flexibility due to low crosslink density. In addition, the expression of crystallinity means a high intermolecular force, which suppresses the movement of molecules, achieves low thermal expansibility, exhibits high thermal diffusivity, and improves thermal conductivity.

  Accordingly, the higher the degree of crystallinity of the cured molded product of the present invention, the better. Here, the degree of crystallization can be evaluated from the endothermic amount accompanying the melting of the crystal in the scanning differential thermal analysis. A preferable endothermic amount is 10 J / g or more per unit weight of the resin component excluding the filler. More preferably, it is 30 J / g or more, Most preferably, it is 50 J / g or more. When smaller than this, the improvement effect of the heat resistance, low thermal expansibility, and thermal conductivity as a molded product is small. The endothermic amount referred to here refers to the endothermic amount obtained by measuring with a differential scanning calorimeter using a sample accurately weighed about 10 mg in a nitrogen stream under a temperature rising rate of 10 ° C./min. . Further, the crystallized cured molded product of the present invention can be observed as a clear peak even in wide-angle X-ray diffraction. In this case, the crystallinity can be obtained by dividing the area obtained by subtracting the peak of the amorphous resin that is not crystallized from the entire peak area by the entire peak area. The desired crystallinity thus obtained is 15% or more, more preferably 30% or more, and particularly preferably 50% or more.

  The cured molded product of the present invention can be obtained by heat reaction by the above molding method. Usually, the molding temperature is 80 ° C. to 250 ° C. In order to increase the crystallinity of the molded product, It is desirable to react at a temperature lower than the melting point of the molded product. A preferable molding temperature is in the range of 100 ° C to 200 ° C, more preferably 130 ° C to 180 ° C. The preferable molding time is 30 seconds to 1 hour, more preferably 1 minute to 30 minutes. Further, after molding, the crystallinity can be further increased by post-cure. Usually, the post-cure temperature is 130 ° C. to 250 ° C., and the time is in the range of 1 hour to 20 hours. However, the temperature is 5 ° C. to 40 ° C. lower than the endothermic peak temperature in the differential thermal analysis. It is desirable to perform post-cure.

  Hereinafter, the present invention will be described more specifically with reference to examples.

Reference example 1
In a 2 L separable flask, 87.3 g (0.4 mol) of 4,4′-difluorobenzophenone, 176.2 g (1.6 mol) of hydroquinone, 98.7 g of 86.0% potassium carbonate, N-methylpyrrolidone (NMP) 941 g and toluene 145 g were charged and stirred at room temperature for 1 hour under a nitrogen stream. Then, it heated up at 140 degreeC and stirred for 4 hours, distilling off water. Thereafter, the mixture was further heated to 205 ° C. and stirred for 4 hours while distilling off NMP. After cooling, the reaction product was added dropwise to a large amount of water (5 L), and the product was filtered through a glass filter. The product was further recovered by washing with 1500 ml of water. Then, after neutralizing with 30% sulfuric acid aqueous solution, it was dried to obtain 150.8 g of a solid (phenolic compound in which A is a 1,4-phenylene group in the general formula (2)). The melting point peak based on the capillary method was 208.3 ° C. to 215.4 ° C. The OH equivalent was 214.0 g / eq.

Reference example 2
40.0 g of the phenolic compound obtained in Reference Example 1, 864.5 g of epichlorohydrin and 120 g of diethylene glycol dimethyl ether were charged, and 18.0 g of 48.8% aqueous sodium hydroxide solution was added at 65 ° C. under reduced pressure (about 130 Torr) over 3 hours. And dripped. 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 and dehydrated. Thereafter, epichlorohydrin was concentrated, and the resulting product was added dropwise to 2 L of MeOH. The resulting product was filtered, washed with ethanol, and dried to obtain 29.5 g of a white powdery solid. From GPC measurement, n = 1 was 97.9%, and n = 2 bodies was 2.1%. The epoxy equivalent was 262 g / eq, and the melting point obtained by the capillary method at a heating rate of 2 ° C./min was 192.7 ° C. to 194.6 ° C.

Reference example 3
The reaction was carried out in the same manner as in Reference Example 1 using resorcinol instead of hydroquinone. After the reaction, NMP was distilled off under reduced pressure, 700 mL of MIBK was added, neutralized with 30% aqueous sulfuric acid solution, and then washed with water. Thereafter, the solvent was distilled off under reduced pressure to obtain 124 g of a brown resin. From GPC measurement, n = 1 was 40%, n = 2 bodies were 32%, and n ≧ 3 bodies were 28%. The softening point was 102.5 ° C., the melt viscosity at 150 ° C. was 1.5 Pa · s, and the OH equivalent was 172.0 g / eq.

Reference example 4
The reaction was performed in the same manner as in Reference Example 2 using 40.0 g of the phenolic compound obtained in Reference Example 3. Thereafter, epichlorohydrin was distilled off under reduced pressure, 150 mL of MIBK was added, and after filtration and washing with water, MIBK was distilled off under reduced pressure to obtain 30.4 g of a brown resin. From GPC measurement, n = 1 was 36%, n = 2 bodies were 30%, and n ≧ 3 bodies were 34%. The softening point was 83 ° C., the melt viscosity at 150 ° C. was 0.6 Pa · s, and the epoxy equivalent was 239 g / eq.

Examples 1-4, Comparative Examples 1-3
As an epoxy resin, the epoxy resins (epoxy resins A and B) obtained in Reference Examples 2 and 4 and a biphenyl epoxy resin (epoxy resin C: manufactured by Japan Epoxy Resin, YX-4000H, epoxy equivalent 193, melting point 105 ° C.) are used. To do. Bisphenol F (curing agent A; manufactured by Honshu Chemical Co., dinuclear purity 92.5 wt%), dihydroxy diphenyl ketone (curing agent B), phenol novolak (curing agent C: manufactured by Gunei Chemical Co., PSM-4261) OH equivalent weight 103, softening point 80 ° C.). Triphenylphosphine is used as a curing accelerator, and spherical alumina (average particle size 12.2 μm) is used as an inorganic filler.

  After blending the components shown in Table 1 and thoroughly mixing with a mixer, the mixture kneaded for about 5 minutes with a heating roll was cooled and ground to obtain the epoxy resin compositions of Examples 1 to 4 and Comparative Examples 1 to 3, respectively. Obtained. Using this epoxy resin composition, after molding at 170 ° C. for 5 minutes, post-curing was carried out at 170 ° C. for 12 hours to obtain a molded product to obtain a cured molded product, and its physical properties were evaluated. The results are summarized in Table 1. In addition, the number of each component in Table 1 represents parts by weight.

[Evaluation]
(1) Thermal conductivity Thermal conductivity was measured by the unsteady hot wire method using an LFA447 type thermal conductivity meter manufactured by NETZSCH.
(2) Thermal (linear) linear expansion coefficient, glass transition temperature The thermal expansion coefficient and glass transition temperature were measured at a heating rate of 10 ° C./min using a TMA120C type thermomechanical measuring device manufactured by Seiko Instruments Inc. did.
(3) Water absorption rate A disk having a diameter of 50 mm and a thickness of 3 mm was formed, and after post-curing, the weight change rate after absorbing for 100 hours under the conditions of 85 ° C. and relative humidity of 85% was used.

Claims (5)

In an epoxy resin composition containing an epoxy resin and a curing agent, 50 wt% or more of the epoxy resin is an epoxy resin having an ether ether ketone group represented by the following formula (1), and 50 wt% or more of the curing agent is a bifunctional phenol. An epoxy resin composition, which is a functional compound.

(However, A is 1,4-phenylene group, 1,3-phenylene group, 4,4′-biphenylene group, 4,4′-diphenyl ether group, 4,4′-diphenyl ketone group, 4,4′-diphenylmethane. A divalent aromatic group selected from a group, 4,4′-diphenyl sulfide group or naphthylene group, m is 1 to 10, and n is a number from 0 to 50.)   Bifunctional phenolic compounds are hydroquinone, 4,4′-dihydroxybiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl ketone, 1,4-bis (4-hydroxyphenoxy) benzene, dihydroxydiphenylmethanes 2. The epoxy resin composition according to claim 1, which is at least one phenolic compound selected from the group consisting of 4,4′-dihydroxydiphenyl sulfide or naphthalenediols.   The epoxy resin composition according to claim 1 or 2, which contains 50 to 96 wt% of an inorganic filler.   The epoxy resin composition according to claim 1, which is an epoxy resin composition for electronic materials.   A molded product obtained by molding and curing the epoxy resin composition according to claim 1.