JP6605828B2 - Polyvalent hydroxy resin, epoxy resin, production method thereof, epoxy resin composition and cured product thereof - Google Patents

Description

  The present invention relates to an epoxy resin composition excellent in high Tg property, thermal decomposition stability and high thermal conductivity, a cured product, and an epoxy resin used therein.

  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.

  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. In addition, 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. It wasn't something we focused on. Furthermore, Patent Document 6 discloses a biphenol aralkyl type epoxy resin composition, which describes that it is excellent in low stress property, thermal conductivity, etc., but was not focused on thermal decomposition stability. . Further, Patent Document 7 discloses a biphenol aralkyl type epoxy resin in which the content of a low molecular weight component is defined, and describes that it is excellent in solvent solubility, thermal conductivity, thermal decomposition stability, and the like. However, it was not sufficient in the expression of thermal conductivity and thermal decomposition stability.

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 JP 2013-209503 A Japanese Patent Laying-Open No. 2015-3972

  The object of the present invention is to provide a sealing material for electrical and electronic parts that provides a cured product excellent in high Tg property, thermal decomposition stability, high thermal conductivity, and the like 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 such as a heat dissipation sheet and a high heat dissipation substrate, and to provide a cured product thereof. Another object is to provide an epoxy resin used in the epoxy resin composition.

下記一般式（２）で表される芳香族架橋剤

とを反応させて得られることを特徴とする下記一般式（３）で表される多価ヒドロキシ樹脂である。

（ここで、ｎは０〜２０の数を示す。） The present invention relates to a biphenol compound represented by the following general formula (1):

Aromatic crosslinking agent represented by the following general formula (2)

And a polyvalent hydroxy resin represented by the following general formula (3).

(Here, n represents a number from 0 to 20.)

  Moreover, this invention is said polyvalent hydroxy resin (3), Comprising: Total chlorine amount is 10,000 ppm or less, It is polyvalent hydroxy resin characterized by the above-mentioned.

  In addition, the present invention reacts a biphenol compound represented by the general formula (1) with an aromatic crosslinking agent represented by the general formula (2) to produce a polyvalent hydroxy resin represented by the general formula (3). In the production, it is a polyvalent hydroxy resin obtained by reacting the above reaction in the presence of an acid catalyst of 100 to 5000 ppm.

  Further, in the production of the polyvalent hydroxy resin represented by the general formula (3), the present invention provides the biphenol compound represented by the general formula (1) and the aromatic represented by the general formula (2). The method for producing a polyvalent hydroxy resin, wherein the crosslinking agent is reacted in the presence of 100 to 5000 ppm of an acid catalyst.

  Moreover, this invention is an epoxy resin obtained by making said polyhydric hydroxy resin and epichlorohydrin react.

  Furthermore, the present invention is an epoxy resin composition comprising the above epoxy resin and a curing agent as essential components. This epoxy resin composition can contain an inorganic filler as an essential component, and an inorganic filler having a thermal conductivity of 20 W / m · K or more is used as a part or all of the inorganic filler in this case. Can do. Moreover, the use of this epoxy resin composition can be expanded by dissolving or suspending it in a solvent.

  Furthermore, the present invention is a prepreg characterized by combining the above epoxy resin composition with a fibrous base material. Moreover, this invention is a hardened | cured material formed by hardening | curing 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, and this cured product is excellent in terms of high Tg property, thermal decomposition stability, and high thermal conductivity. And can be suitably used for applications such as sealing materials for electric and electronic parts, circuit board materials such as high heat dissipation sheets and high heat dissipation boards.

  The polyvalent hydroxy resin of the present invention is a polyvalent hydroxy resin obtained by a condensation reaction between a biphenol compound represented by the general formula (1) and an aromatic crosslinking agent represented by the general formula (2). This resin is inferior in reactivity compared with the case of the phenol aralkyl resin obtained by the reaction of the generally well-known phenol and the aromatic crosslinking agent represented by the general formula (2). This is because the biphenol compound has high crystallinity and poor solubility, and as a result, unreacted components containing chlorine are likely to remain in the resin. In order to reduce such unreacted components containing chlorine, the reaction is preferably performed in the presence of an acid catalyst. The reaction proceeds even in the absence of a catalyst, but 10,000 ppm or more of unreacted components containing chlorine remain. On the other hand, when an acid catalyst is used, unreacted components can be reduced to 10000 ppm or less at a reaction temperature of 160 ° C. or less and a reaction time of 12 hours or less.

  In the polyvalent hydroxy resin of the present invention, the total chlorine content in the resin is preferably 10,000 ppm or less. When the total amount of chlorine is large, in a cured product obtained by curing using an epoxy resin obtained by epoxidizing the present polyvalent hydroxy resin, the glass transition point (Tg) is lowered and the thermal decomposition stability is lowered.

  The polyvalent hydroxy resin of the present invention uses p-xylylene dichloride represented by the general formula (2) as an aromatic crosslinking agent. When the condensation reaction is carried out using this crosslinking agent, the reactivity is higher than when the condensation reaction is carried out using p-xylylene glycols or p-xylylene dialkoxides. The reaction can be reduced. However, it is preferable to add a catalyst rather than no catalyst in order to reduce unreacted components containing chlorine and improve physical properties. Since the polyvalent hydroxy resin of the present invention is a reaction under relatively mild conditions using p-xylylene dichloride as an aromatic cross-linking agent, the regioselectivity of the electrophilic addition reaction of the cross-linking agent to biphenol is improved. It is easy to add a crosslinking agent in the ortho position with respect to the hydroxyl group of biphenol. By increasing the regularity of the molecular chain of the resulting resin, the cured product cured with the present epoxy resin will increase the orientation of the molecular chain in the cured product, and high thermal conductivity is easily exhibited. It is considered to be.

  The reaction for obtaining the polyvalent hydroxy resin is performed in the presence of an acid catalyst such as a known inorganic acid or organic acid. Examples of such an acid catalyst include mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid, organic acids such as formic acid, oxalic acid, trifluoroacetic acid, and p-toluenesulfonic acid, zinc chloride, aluminum chloride, iron chloride, Examples include Lewis acids such as boron trifluoride and solid acids such as activated clay, silica-alumina, and zeolite.

  The amount of the catalyst used is preferably 100 to 5000 ppm with respect to the total weight of 4,4′-dihydroxybiphenyl and p-xylylene dichloride. A more preferable range is 100 to 1000 ppm. When the amount of the catalyst is less than this, the reaction promoting effect is low, the reaction time is increased, and the productivity is greatly inferior.

  Usually, this reaction is performed at 10 to 250 ° C. for 1 to 20 hours. Further, as a solvent during the reaction, for example, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, ethyl cellosolve, diglyme and triglyme, and aromatic compounds such as benzene, toluene, chlorobenzene and dichlorobenzene Of these, ethyl cellosolve, diglyme, triglyme and the like are particularly preferable. After completion of the reaction, the obtained polyvalent hydroxy resin may be removed by a method such as distillation under reduced pressure, washing with water or reprecipitation in a poor solvent, but as a raw material for the epoxidation reaction while leaving the solvent. It may be used.

  The epoxy resin of the present invention can be produced by reacting the above polyvalent hydroxy resin with epichlorohydrin. This reaction can be performed in the same manner as a normal epoxidation reaction. For example, after dissolving a polyvalent hydroxy resin in excess epichlorohydrin, the reaction is carried out at 50 to 150 ° C., preferably 60 to 120 ° C. for 1 to 10 hours in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide. The method of letting it be mentioned. Under the present circumstances, the usage-amount of an alkali metal hydroxide is 0.8-1.2 mol with respect to 1 mol of hydroxyl groups in a polyvalent hydroxy compound, Preferably it is 0.9-1.0 mol. If it is less than this, the amount of total chlorine will increase, and if it is more than this, the amount of gel produced during the epoxy resin synthesis will increase, causing the formation of an emulsion during washing with water and causing a decrease in yield, which is not preferable. Epichlorohydrin is used in excess with respect to the hydroxyl group in the polyvalent hydroxy resin, but is usually 1.5 to 15 mol, preferably 2 to 8 mol, relative to 1 mol of the hydroxyl group in the polyvalent hydroxy compound. 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 solvent is distilled off to give a general formula. The epoxy resin represented by (1) can be obtained. In the case of epoxidation, when the epoxy group of the produced epoxy compound is ring-opened and condensed to form an oligomerized epoxy compound, a small amount of such an epoxy compound may be present.

The purity of the epoxy resin of the present invention, in particular, the total chlorine amount, is preferably small from the viewpoint of improving the performance of the applied electronic component. In particular, in the present invention, polyhydroxyl having a total chlorine content reduced to 10,000 ppm or less by controlling reaction conditions while using p-xylylene dichloride represented by the formula (2) as an aromatic crosslinking agent. In a cured product obtained by using an epoxy resin derived from a resin, high Tg property, thermal decomposition stability, and thermal conductivity are improved. The total chlorine content of the epoxy resin is preferably 2000 ppm or less, more preferably 1500 ppm or less. In addition, the total chlorine as used in the field of this invention means the value measured by the following method. That is, after dissolving 0.5 g of a sample in 30 ml of dioxane, adding 0.1 N-KOH and 25 ml, heating and refluxing for 10 minutes, cooling to room temperature, adding 100 ml of 80% acetone water, and adding 0.01 N-AgNO ₃ aqueous solution It is a value obtained by performing potentiometric titration with.

  In the production of the epoxy resin of the present invention, when the total chlorine amount is reduced, the lower the total chlorine amount of the polyvalent hydroxy resin used for epoxidation, the better. When the total chlorine amount of the epoxy resin is 2000 ppm or less, the total chlorine amount of the polyvalent hydroxy resin to be used is preferably 15000 ppm or less. Furthermore, when the total chlorine amount of the epoxy resin is 1500 ppm or less, the polyvalent hydroxy to be used The total chlorine content of the resin is preferably 10,000 ppm or less.

  The softening point or melting point of the epoxy resin can be easily adjusted by changing the molar ratio of the biphenols and the crosslinking agent when synthesizing the polyvalent hydroxy resin that is the raw material of the epoxy resin. 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 undissolved remaining high melting point components during the mixing treatment. When the softening point or melting point is higher than this, physical properties such as curability and heat resistance tend to be lowered.

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

  As the curing agent to be blended in the epoxy resin composition of the present invention, polyhydric phenols are preferably used as the curing agent in fields where high electrical insulation properties such as semiconductor sealing materials are required. Below, the specific example of a hardening | curing agent is shown.

  Examples of the 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 , Resorcinol, catechol, naphthalenediols and other divalent phenols 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 methylbiphenyls, divinylbiphenyls, diisopropenylbiphenyls, biphenylaralkyl type phenol resins obtained from phenols and bischloromethylbiphenyls, 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.

  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) 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 bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl, resorcin, naphthalenediols Trivalent or higher epoxides such as divalent phenols such as tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak, etc. Epoxidized products of phenols, epoxidized products of cocondensation resins obtained from dicyclopentadiene and phenols, epoxidized products of cocondensation resins obtained from cresols, formaldehyde and alkoxy-substituted naphthalenes, phenols and paraxylylene dichloride Obtained from etc. E Nord aralkyl resin epoxidized product, there phenols and bis-chloromethyl biphenyl biphenyl aralkyl type phenolic resins obtained from the epoxy compound, 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 the epoxy resin of this invention in the whole epoxy resin should be 50-100 wt%, Preferably it is the range of 60-100 wt%, and the compounding quantity of another kind of epoxy resin is 0-40 wt%. A range is preferable.

  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 less than this, low elasticity will not be exhibited sufficiently. On the other hand, if the amount 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 blending an inorganic filler, examples of the inorganic filler include spherical or crushed fused silica, crystalline silica and other silica powder, alumina powder, glass powder, or mica, talc, calcium carbonate, alumina, hydration Alumina etc. are mentioned, The preferable compounding quantity when using for a semiconductor sealing material is 70 weight% or more, More preferably, it is 80 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 70% 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 addition to the above essential components, other additives can be added to the epoxy resin composition of the present invention.

  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. Although it is desirable that the epoxy resin in the resin composition is completely dissolved, the epoxy resin of the present invention has the characteristics that it is excellent in solubility and the solid content hardly precipitates in the storage state. When a part of the epoxy resin in the varnish becomes a solid and separates, the properties of the cured epoxy resin 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 also be set as a laminated body by laminating | stacking the said prepreg two or more 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.

Test conditions for the epoxy resin, the epoxy resin composition and the cured product are shown below.
1) 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.

2) Softening point It measured by the ring and ball method according to JIS-K-2207 using the automatic softening point apparatus (Myohosha make, ASP-M4SP).

4) Melt viscosity It measured at 150 degreeC using the Toa Kogyo Co., Ltd. make and ICI cone plate viscometer CV-1S.

3) Total chlorine After dissolving 0.5 g of the sample in 30 ml of dioxane, 0.1 N-KOH, 25 ml was added and heated under reflux for 10 minutes, then cooled to room temperature, and further 100 ml of 80% acetone water was added, and 0.01 N-AgNO. It measured by performing potentiometric titration with ₃ aqueous solution.

4) 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).

5) Weight retention (wt%)
Using a thermostat with a rotating frame, the weight retention (wt%) was determined from the difference between the weight of the test piece after 1000 hours at 250 ° C. and the weight of the test piece before heating.

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

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

Example 1
In a 2 L 4-neck flask, 186 g (1.0 mol) of 4,4′-dihydroxybiphenyl, 87.5 g (0.5 mol) of p-xylylene dichloride, 273 g of diethylene glycol dimethyl ether as a solvent, p-toluenesulfone as an acid catalyst 1.37 g (5000 ppm) of acid was charged and the temperature was raised to 160 ° C. Next, it was made to react for 12 hours, stirring at 160 degreeC. Subsequently, the solvent was distilled off under reduced pressure. The total chlorine content of this polyvalent hydroxy resin was 7800 ppm. Into 237 g of the obtained resin, 185 g of epichlorohydrin was charged and dissolved. Subsequently, 163.3 g of a 49% sodium hydroxide aqueous solution was added dropwise at 70 ° C. under reduced pressure over 4 hours, and water and epichlorohydrin distilled under reflux were separated in the dropping tank 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 262 g of epoxy resin (epoxy resin A). The epoxy equivalent of the obtained resin was 186 g / eq. The softening point was 123 ° C., the melt viscosity at 150 ° C. was 0.33 Pa · s, and the total chlorine was 1410 ppm.

Example 2
A 1 L 4-necked flask was charged with 186 g (1.0 mol) of 4,4′-dihydroxybiphenyl, 87.5 g (0.5 mol) of p-xylylene dichloride and 273 g of diethylene glycol dimethyl ether as a solvent, and the temperature was raised to 160 ° C. . Next, it was made to react for 12 hours, stirring at 160 degreeC. Subsequently, the solvent was distilled off under reduced pressure. The total chlorine content of this polyvalent hydroxy resin was 14300 ppm. Into 237 g of the obtained resin, 185 g of epichlorohydrin was charged and dissolved. Subsequently, 163.3 g of a 49% aqueous sodium hydroxide solution was added dropwise at 70 ° C. under reduced pressure over 4 hours, and water and epichlorohydrin distilled under reflux were separated in the dropping 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 255 g of epoxy resin (epoxy resin B). The epoxy equivalent of the obtained resin was 189 g / eq. The softening point was 120 ° C., the melt viscosity at 150 ° C. was 0.30 Pa · s, and the total chlorine was 1950 ppm.

Comparative 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 (10000 ppm) 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 C). The epoxy equivalent of the obtained resin was 185 g / eq. Met. The softening point was 125 ° C., and the melt viscosity at 150 ° C. was 0.48 Pa · s.

Comparative Example 2
A 1 L 4-neck flask was charged with 94 g (1.0 mol) of phenol, 87.5 g (0.5 mol) of p-xylylene dichloride and 182 g of diethylene glycol dimethyl ether as a solvent, and the temperature was raised to 160 ° C. Next, it was made to react for 12 hours, stirring at 160 degreeC. Subsequently, the solvent and unreacted phenol were distilled off under reduced pressure. The total chlorine content of this polyvalent hydroxy resin was 80 ppm. In 100 g of the obtained resin, 211 g of epichlorohydrin was charged and dissolved. Subsequently, 46.7 g of a 49% aqueous sodium hydroxide solution was added dropwise at 70 ° C. under reduced pressure over 4 hours, and water and epichlorohydrin refluxed during the addition 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 112 g of epoxy resin (epoxy resin D). The epoxy equivalent of the obtained resin was 243 g / eq. The softening point was 67 ° C., the melt viscosity at 150 ° C. was 0.28 Pa · s, and the total chlorine was 830 ppm.

Examples 3-4, Comparative Examples 3-5
Table 1 shows the epoxy resins A to D obtained in Examples 1 and 2 and Comparative Examples 1 and 2, a curing agent, an inorganic filler, triphenylphosphine as a curing accelerator, and other additives. An epoxy resin composition was prepared by kneading at a ratio. The numerical value in a table | surface shows the weight part in a mixing | blending.

  Other ingredients used are shown below. PN was used as a curing agent, spherical alumina was used as an inorganic filler, carnauba wax was used as a release agent, and carbon black was used as a colorant.

Epoxy resin E: o-cresol novolac type epoxy resin (epoxy equivalent 200, softening point 65 ° C., manufactured by Nippon Steel Chemical Co., Ltd.)
PN: phenol novolak (PSM-4261 (manufactured by Gunei Chemical), OH equivalent 103, softening point 82 ° C.)
Spherical alumina: Product name; DAW-100, manufactured by Denki Kagaku Kogyo Co., Ltd., thermal conductivity 38 W / m · K
Triphenylphosphine: product name; Hokuko TPP, carnauba wax manufactured by Hokuko Chemical Co., Ltd .: product name; purified carnauba wax No. 1. Carbon black manufactured by Celerica NODA Co., Ltd .: Product name; MA-100, manufactured by Mitsubishi Chemical Corporation

  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 Table 1.

Claims (7)

In producing a polyvalent hydroxy resin represented by the following general formula (3), a biphenol compound represented by the following general formula (1) and an aromatic crosslinking agent represented by the following general formula (2): A method for producing a polyvalent hydroxy resin , wherein the reaction is carried out in the presence of 100 to 5000 ppm of an acid catalyst.

(Here, n represents a number from 0 to 20.) An epoxy resin production method obtained by reacting a polyvalent hydroxy resin obtained by the production method according to claim 1 with epichlorohydrin. Method for producing an epoxy resin composition, characterized in that an epoxy resin and a curing agent as essential components obtained by the production method according to claim 2. An inorganic filler is further contained as an essential component in the epoxy resin composition obtained by the production method according to claim 3, and the inorganic material has a thermal conductivity of 20 W / m · K or more as part or all of the inorganic filler. The manufacturing method of the epoxy resin composition characterized by using a filler. The method for producing an epoxy resin composition according to claim 3 or 4 , wherein the epoxy resin composition is in a state of being dissolved or suspended in a solvent. A method for producing a prepreg , characterized in that the epoxy resin composition obtained by the production method according to any one of claims 3 to 5 is combined with a fibrous base material. The method according to claim 3-5 epoxy resin cured product, characterized in that curing the epoxy resin composition obtained by the production method according to any one of.