JP5841947B2 - Epoxy resin composition and cured product - Google Patents

Description

  The present invention relates to an epoxy resin composition that provides a cured product that is excellent in flame retardancy and also excellent in fluidity and curability during molding, and the cured product.

  In recent years, particularly with the advancement of the advanced material field, development of higher performance base resins has been demanded. For example, in the field of semiconductor encapsulation, the problem of package cracking has become serious due to the reduction in the size and area of packages corresponding to recent high-density mounting, and the spread of surface mounting methods. There is a strong demand for improvement in moisture resistance, heat resistance, adhesion to metal substrates, and the like. Furthermore, from the viewpoint of reducing the environmental load, there is a movement to eliminate halogen-based flame retardants, and there is a demand for a base resin that is more excellent in flame retardancy.

  However, it is not yet known that conventional epoxy resin-based materials sufficiently satisfy these requirements. For example, the well-known bisphenol type epoxy resin is in a liquid state at room temperature and is widely used because it is excellent in workability and easy to mix with a curing agent, an additive, etc. There is a problem in terms of moisture resistance. Also, phenol novolac type epoxy resins are known as improved heat resistance, but there are problems with moisture resistance and impact resistance. JP-A-63-238122 proposes an epoxy compound of a phenol aralkyl resin for the purpose of improving moisture resistance and impact resistance, but it is not sufficient in terms of heat resistance and flame retardancy.

  JP-A-9-235449, JP-A-10-182792 and the like disclose a method for adding a phosphate ester-based flame retardant as a measure for improving flame retardancy without using a halogen-based flame retardant. Has been. However, the method using a phosphate ester flame retardant does not have sufficient moisture resistance. In addition, the phosphoric acid ester is hydrolyzed under a high temperature and humidity environment, and there is a problem that the reliability as an insulating material is lowered.

JP-A-11-140166 JP 2004-57992 A Japanese Patent Laid-Open No. 4-173831 JP 2000-129092 A Japanese Patent Laid-Open No. 3-90075 JP-A-3-281623 JP-A-8-120039 Japanese Patent Laid-Open No. 5-140265

  Patent Documents 1, 3, and 4 disclose an example in which an aralkyl epoxy resin having a biphenyl structure is applied to a semiconductor sealing material as an element that improves flame retardancy without containing phosphorus atoms or halogen atoms. Yes. Patent Document 2 discloses an example in which an aralkyl type epoxy resin having a naphthalene structure is used. However, these epoxy resins have insufficient performance in any of flame retardancy, moisture resistance, and heat resistance. Patent Documents 5 and 6 disclose a naphthol-based aralkyl epoxy resin and a semiconductor sealing material containing the naphthol-based aralkyl epoxy resin, but nothing focuses on flame retardancy. On the other hand, Patent Document 7 discloses benzylated polyphenol and its epoxy resin as an example focusing on improving heat resistance, moisture resistance and crack resistance, but these do not focus on flame retardancy. In addition, benzylated polyphenol type epoxy resins have a problem in flowability during molding as the molecular weight increases due to benzylation. Furthermore, Patent Document 8 discloses an epoxy resin composition containing a styrenated phenol novolac type epoxy resin, which is excellent in low water absorption and low stress, but does not focus on flame retardancy, Performance is not sufficient in fluidity during molding.

  Therefore, the object of the present invention is to ensure non-halogen flame retardancy, and also has excellent performance in fluidity and curability during molding, for use in lamination, molding, casting, adhesion, etc. An object of the present invention is to provide a useful epoxy resin composition and a cured product thereof.

  That is, the present invention provides an epoxy resin composition containing an epoxy resin, a phenolic curing agent, and an inorganic filler, wherein the epoxy resin component is an amorphous epoxy resin represented by the following general formula (1) and 150 ° C. Containing a bifunctional crystalline epoxy resin having a melt viscosity of 0.001 to 0.05 Pa · s, and the content of the amorphous epoxy resin represented by the following general formula (1) with respect to the entire epoxy resin The epoxy resin composition is characterized in that the content of the bifunctional crystalline epoxy resin is 30% by weight or more.

（一般式（１）において、Ｇはグリシジル基を示し、Ｒ_１は水素又は炭素数１〜６の炭化水素基を示し、Ｒ_２は下記式（ａ）で表される置換基を示し、ｎは１〜２０の数を示す。また、ｐは０．１〜２．５の数を示す。式（ａ）において、Ｒ_３は水素原子又は炭素数１〜６の炭化水素基を示す。）

(In General Formula (1), G represents a glycidyl group, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents a substituent represented by the following formula (a), and n Represents a number of 1 to 20. Further, p represents a number of 0.1 to 2.5.In the formula (a), R ₃ represents a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms.

（ここで、Ｒ_４〜Ｒ_１１は水素原子及び炭素数１〜６の炭化水素基から選ばれ、全てが同一でも異なっていてもよい。Ｘは、単結合、−ＣＨ_２−、−Ｃ（ＣＨ_３）_２−、−ＣＯ−、−Ｏ−、−Ｓ−または−ＳＯ_２−を示す。Ｇはグリシジル基を示し、ｍは０〜３の数を示す。）The bifunctional crystalline epoxy resin component may be an epoxy resin represented by the following general formula (2).

(Here, R _{4 to} R ₁₁ are selected from a hydrogen atom and a hydrocarbon group having 1 to 6 carbon atoms, and all may be the same or different. X is a single bond, —CH ₂ —, —C ( CH ₃ ) ₂ —, —CO—, —O—, —S— or —SO ₂ —, G represents a glycidyl group, and m represents a number of 0 to _3. )

  Moreover, it is preferable that the said hardening | curing agent component contains at least 1 sort (s) among an aralkyl type phenol type hardening | curing agent and a novolak type phenol hardening agent.

  Furthermore, this invention relates to said epoxy resin composition whose content rate of an inorganic filler is 70 to 95 weight%, and the epoxy resin hardened | cured material formed by hardening | curing these epoxy resin compositions.

  The epoxy resin composition of the present invention comprises two kinds of epoxy resin components, a phenolic curing agent component and an inorganic filler as essential components. Advantageously, these essential components are contained in an amount of 50% by weight or more, preferably 80% by weight or more, more preferably 95% by weight or more.

  First, the epoxy resin represented by the general formula (1) which is the first type of epoxy resin component in the epoxy resin composition of the present invention will be described. The epoxy resin represented by the general formula (1) is an amorphous epoxy resin. The epoxy resin represented by the general formula (1) can be obtained by epoxidizing the styrene-added polyvalent hydroxy resin represented by the general formula (3). Further, the styrene-added polyvalent hydroxy resin (also referred to as StPN) represented by the general formula (3) comprises a polyvalent hydroxy compound (also referred to as the polyvalent hydroxy compound (4)) represented by the general formula (4) and styrenes. It can be obtained by addition reaction.

（Ｒ_１は水素又は炭素数１〜６の炭化水素基を示し、Ｒ_２は上記式（ａ）で表される置換基を示し、ｎは０〜２０の数を示す。また、ｐは０．１〜２．５の数を示す。）

（ここで、Ｒ_１は水素又は炭素数１〜６の炭化水素基を示し、ｎは１〜２０の数を示す。）

(R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents a substituent represented by the above formula (a), n represents a number of 0 to 20, and p represents 0. .Shows numbers from 1 to 2.5.)

(Here, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, and n represents a number of 1 to 20)

  In the styrene-added polyvalent hydroxy resin represented by the general formula (3), the hydroxyl equivalent can be arbitrarily adjusted by adding styrene to the basic structure of the polyvalent hydroxy compound (4). . Here, the addition of styrenes means that the hydrogen of the benzene ring of the polyvalent hydroxy compound (4) is substituted with the substituent represented by the formula (a) (also referred to as a styrenyl group). In other words, in the epoxy resin cured product, the hydroxypropyl group generated by the reaction between the epoxy group and the hydroxyl group is said to burn easily, but by increasing the hydroxyl equivalent, aliphatic carbon of the flammable component derived from the epoxy group The rate is low and a high degree of flame retardancy can be expressed. Moreover, by adding styrene rich in aromaticity, the aromaticity is further improved, and it is effective in improving moisture resistance in addition to flame retardancy.

  Therefore, a highly flame-retardant epoxy resin composition, especially an epoxy resin composition for semiconductor encapsulation is obtained using these. In other words, high flame retardancy, moisture resistance and low elasticity are exhibited in addition to excellent curability in these compositions, and highly reliable sealing of electrical and electronic parts and circuits using this material A substrate material or the like is obtained.

  StPN is obtained by addition reaction of the polyvalent hydroxy compound (4) represented by the general formula (4) and styrenes. In this case, the ratio of the polyvalent hydroxy compound (4) and the styrenes is 0 when the ratio of the styrenes to 1 mol of the polyvalent hydroxy compound is 0 in consideration of the balance between flame retardancy and curability of the resulting cured product. The range is preferably from 1 to 2.5 mol, more preferably from 0.1 to 1.0 mol, still more preferably from 0.3 to 0.8 mol. When the amount is less than this range, the properties of the starting polyvalent hydroxy compound are not improved. When the amount is more than this range, the functional group density tends to be too low and the curability tends to decrease.

In general formula (3) and general formula (1), a common symbol has the same meaning. R ₁ represents a styryl group represented by the above formula (a). p shows the number of 0.1-2.5, and this means the average number (number average) of the styryl group which substitutes to one phenol ring. p is preferably in the order of 0.1 to 2 mol, 0.1 to 1.0 mol, 0.3 to 1 mol, and 0.3 to 0.8 mol. In addition, a maximum of 4 styryl groups can be substituted on the phenol ring at both ends, and a maximum of 3 styryl groups can be substituted on the intermediate phenol ring. Therefore, when n is 1, a maximum of 8 styryl groups can be substituted. it can.
From another point of view, the StPN used in the present invention preferably has a substitution number (number average) of styryl groups per molecule of 1 or more, more preferably 2 or more, and still more preferably 2.6 to 4.

In formula (a), R ₃ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, preferably hydrogen or an alkyl group having 1 to 3 carbon atoms, and more preferably hydrogen. This R ₃ is determined by the styrenes used as reaction raw materials.

  In the general formula (1), n represents a number of 1 to 20, preferably 1.5 to 5.0 as an average.

  Next, a method for manufacturing StPN will be described. The production method of StCN is performed by reacting 0.1 to 2.5 mol of styrene with 1 mol of the hydroxy group of the polyvalent hydroxy compound represented by the general formula (4) in the presence of an acid catalyst. . Typical examples of the polyvalent hydroxy compound represented by the general formula (4) include phenol novolac and cresol novolak. Although the usage-amount of styrene is 0.1-2.5 with respect to 1 mol of hydroxy groups, 0.1-1.0 are preferable and 0.3-0.8 are more preferable.

  The phenols used to obtain the polyvalent hydroxy compound (4) are phenols or phenols substituted with a hydrocarbon group having 1 to 6 carbon atoms, preferably phenol or alkyl having 1 to 4 carbon atoms. Phenols substituted with a group, more preferably phenol. When phenol is used as the phenol, it may contain a small amount of other phenol components. For example, o-cresol, m-cresol, p-cresol, ethylphenols, isopropylphenols, tertiary butylphenols, allylphenols, phenylphenols, 2,6-xylenol, 2,6-diethylphenol, hydroquinone, Resorcin, catechol, 1-naphthol, 2-naphthol, 1,5-naphthalenediol, 1,6-naphthalenediol, 1,7-naphthalenediol, 2,6-naphthalenediol, 2,7-naphthalenediol, etc. . These phenols or naphthols may contain 2 or more types.

  The styrene used for the reaction with the polyvalent hydroxy compound is styrene or styrene substituted with a hydrocarbon group having 1 to 6 carbon atoms, and is preferably styrene. These styrenes may contain a small amount of other reaction components. When styrene is used as the styrenes, other reaction components include α-methylstyrene, divinylbenzene, indene, coumarone, benzothiophene, indole, vinylnaphthalene, etc. In this case, the resulting polyvalent hydroxy compound includes a compound in which a group resulting therefrom is substituted on the aromatic ring.

  The reaction of polyvalent hydroxy compounds with styrenes can be carried out in the presence of an acid catalyst, and the amount of the catalyst used is in the range of 10 to 1000 ppm, preferably in the range of 100 to 500 ppm. If it is more than this, the methylene crosslinks of phenol novolac will be easily cleaved, and the unit price phenol component by-produced by the cleavage reaction will lower the curability and heat resistance. On the other hand, if it is less than this, the reactivity is lowered, and a large amount of unreacted styrene monomer remains.

  The acid catalyst can be appropriately selected from known inorganic acids and organic acids. For example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, organic acids such as formic acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, dimethyl sulfuric acid, diethyl sulfuric acid, zinc chloride, aluminum chloride, iron chloride, trifluoride. Examples thereof include Lewis acids such as boron fluoride or ion exchange resins, activated clays, silica-alumina, solid acids such as zeolite, and the like.

  Moreover, the reaction temperature in this reaction is performed in the range of 40-120 degreeC. If it is lower than this, the reactivity is lowered and the reaction time is prolonged. On the other hand, if it is higher than this, a part of the methylene crosslink of phenol novolac is likely to be cleaved, and the unit price phenol component by-produced by the open-chain reaction reduces curability and heat resistance.

  Moreover, this reaction is normally performed for 1 to 20 hours. Further, during the reaction, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, ethyl cellosolve, ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, dimethyl ether, diethyl ether, diisopropyl ether, Ethers such as tetrahydrofuran and dioxane, aromatic compounds such as benzene, toluene, chlorobenzene, and dichlorobenzene can be used as the solvent.

  As a specific method for carrying out this reaction, all raw materials are charged in a lump and reacted at a predetermined temperature as it is, or a polyvalent hydroxy compound and a catalyst are charged and maintained at a predetermined temperature while maintaining styrenes. A method of reacting while dropping is generally used. At this time, the dropping time is preferably 5 hours or less, and usually 1 to 10 hours. After the reaction, if a solvent is used, the catalyst component can be removed if necessary, and then the solvent can be distilled off to obtain a resin for use in the present invention. By doing so, the object can be obtained.

The epoxy resin used in the present invention is a bifunctional crystalline epoxy resin having an epoxy resin represented by the above general formula (1) and a melt viscosity at 150 ° C. of 0.001 to 0.05 Pa · s.
Hereinafter, the epoxy resin represented by the general formula (1) is abbreviated as StPNE, and the bifunctional crystalline epoxy resin having a melt viscosity at 150 ° C. of 0.001 to 0.05 Pa · s is referred to as a crystalline epoxy resin. is there. StPNE can be obtained by epoxidizing the above StPN.

In the general formula (1), symbols common to the general formula (3) have the same meaning, but G represents a glycidyl group, which is generated by the reaction of the hydroxyl group of the general formula (3). R ₁ is a styryl group.

  StPNE used in the present invention is advantageously produced by reacting StPN represented by the general formula (3) with epichlorohydrin, but is not limited to this reaction.

  In addition to the reaction of reacting StPN with epichlorohydrin, StPN and allyl halide can be reacted to form an allyl ether compound and then reacted with peroxide. The reaction of reacting StPN with epichlorohydrin can be performed in the same manner as a normal epoxidation reaction.

  For example, after the above StPN is dissolved in excess epichlorohydrin, in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, it is 20 to 150 ° C., preferably 30 to 80 ° C. The method of making it react for time is mentioned. The amount of alkali metal hydroxide used in this case is in the range of 0.8 to 1.5 mol, preferably 0.9 to 1.2 mol, relative to 1 mol of StPN hydroxyl group. In addition, epichlorohydrin is used in excess with respect to 1 mol of hydroxyl group in StPN, but is usually in the range of 1.5 to 30 mol, preferably 2 to 15 mol, relative to 1 mol of hydroxyl group in StPN. 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 composition of the present invention contains the epoxy resin represented by the above general formula (1) in a total epoxy resin component of 30% by weight or more, preferably 30 to 70% by weight, more preferably 40 to 60% by weight. To do.

  In the epoxy resin composition of the present invention, 30 wt.% Of bifunctional crystalline epoxy resin having a melt viscosity of 0.001 to 0.05 Pa · s at 150 ° C. in all epoxy resin components as a second type of epoxy component. % Or more, preferably 30 to 70% by weight, more preferably 40 to 60% by weight. If it is more than this, the flame retardancy will be reduced, and if it is less than this, the fluidity during molding, which is the object of the present invention, will not be sufficiently exhibited.

  The melt viscosity at 150 ° C. of the bifunctional crystalline epoxy resin is 0.001 to 0.05 Pa · s, preferably 0.005 to 0.03 Pa · s. When the melt viscosity is higher than 0.05 Pa · s, it is difficult to increase the filling rate of the inorganic filler, and improvement in performance such as flame retardancy cannot be expected.

As the bifunctional crystalline epoxy resin, an epoxy resin represented by the general formula (2) is preferably used. In the general formula (2), R _{4 to} R ₁₁ are selected from a hydrogen atom and a hydrocarbon group having 1 to 6 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. These may all be the same or different. X represents a single bond, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, —O—, —S— or —SO ₂ —. G represents a glycidyl group. m represents a number from 0 to 3, but m represents a number average value when the resin is composed of a plurality of components having different m.

Preferably, epoxy resins as shown in the following general formulas (5) to (14) are used. In the formula, R _{4 to} R ₁₁ are selected from a hydrogen atom and a hydrocarbon group having 1 to 6 carbon atoms, and all may be the same or different. G shows a glycidyl group, m shows the number of 0-3.

  Bifunctional crystalline epoxy resins may be used alone or in combination of two or more. Among these epoxy resins, it is particularly preferable to use a biphenyl type epoxy resin, a bisphenol F type epoxy resin, and a sulfide type epoxy resin from the viewpoint of achieving both fluidity and flame retardancy.

  The bifunctional crystalline epoxy resin as described above can be synthesized by reacting a compound having a phenolic hydroxyl group typified by a bisphenol compound with epichlorohydrin. This reaction can be performed in the same manner as a normal epoxidation reaction. When using a bisphenol compound, for example, after dissolving the bisphenol compound in excess epichlorohydrin, in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, 50 to 150 ° C., preferably 60 to 120 ° C. The method of making it react for 1 to 10 hours is mentioned. Under the present circumstances, the usage-amount of an alkali metal hydroxide is 0.8-2 mol with respect to 1 mol of hydroxyl groups of a bisphenol compound, Preferably it is 0.9-1.2 mol. 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 obtain the desired It can be an epoxy resin.

The amount of hydrolyzable chlorine in the epoxy resin used in the present invention is preferably small from the viewpoint of improving the reliability of the electronic component to be sealed. Although it does not specifically limit, 1000 ppm or less is preferable, 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. That is, 0.5 g of a sample was dissolved in 30 ml of dioxane, 10 ml of 1N-KOH was added and the mixture was boiled and refluxed for 30 minutes, then cooled to room temperature, and further 100 ml of 80% acetone water was added, and potentiometric titration with 0.002N-AgNO ₃ aqueous solution. Is a value obtained by performing

  The epoxy resin composition of the present invention uses the epoxy resin represented by the general formula (1) as an epoxy resin component and a bifunctional crystalline epoxy resin as essential epoxy resins, but does not impair the purpose of the present invention. Other epoxy resins can be used in combination.

  Examples of such other epoxy resins include epoxidized products of divalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 2,2′-biphenol, resorcin, and naphthalenediol (showing crystallinity). Epoxides of trihydric or higher phenols such as tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak, etc. Epoxidized products of co-condensation resins of dicyclopentadiene and phenols, epoxidized products of phenol aralkyl resins synthesized from phenols and paraxylylene dichloride, biphenyl aralkyls synthesized from phenols and bischloromethylbiphenyl, etc. Epoxidized type phenolic resins, epoxidized naphthol aralkyl resin and the like which are synthesized from naphthols and para-xylylene dichloride and the like. These epoxy resins may be used alone or in combination of two or more. These blending amounts may be in a range that does not impair the object of the present invention, but are less than 50% by weight with respect to the total of StPNE and the bifunctional crystalline epoxy resin.

  Specific examples of the phenolic curing agent used in the epoxy resin composition of the present invention include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone, and resorcinol. Divalent phenols such as catechol and naphthalenediols, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak, naphthol Trivalent or higher phenols typified by novolak, polyvinylphenol, etc., as well as phenols, naphthols, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-bifu Divalent phenols such as enol, hydroquinone, resorcin, catechol, naphthalenediol, and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, p-xylylene glycol, p-xylylene glycol dimethyl ether, divinylbenzene, diisopropenylbenzene And polyphenolic compounds synthesized by reaction with crosslinking agents such as dimethoxymethylbiphenyls, divinylbiphenyls, diisopropenylbiphenyls, and the like.

  The softening point range of the phenolic curing agent is preferably 40 to 150 ° C, more preferably 50 to 120 ° C. If it is lower than this, there is a problem of blocking during storage, and if it is higher than this, there is a problem in kneadability and moldability during preparation of the epoxy resin composition. Further, the melt viscosity at 150 ° C. is preferably 1 Pa · s or less, more preferably 0.5 Pa · s or less. When higher than this, there exists a problem in the kneadability at the time of preparation of an epoxy resin composition, and a moldability.

  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 even after curing, and physical properties such as reliability and water absorption when the cured product is reduced.

  Examples of the inorganic filler used in the present invention include silica, alumina, zircon, calcium silicate, calcium carbonate, silicon carbide, silicon nitride, boron nitride, zirconia, fosterite, steatite, spinel, mullite, and titania. However, it is preferable to use fused silica as a main component, and examples of the form include crushed or spherical ones. Usually, silica is used in combination with those having several kinds of particle size distributions. The range of the average particle diameter of the silica to be combined is preferably 0.5 to 100 μm. The content of the inorganic filler is preferably in the range of 70 to 95% by weight, preferably 80 to 95% by weight, and more preferably 85 to 95% by weight. If it is smaller than this, the content of the organic component becomes high, and the flame retardancy is not sufficiently exhibited. On the other hand, if it is larger than this, the thermal conductivity of the molded product will increase, so that the decomposition rate of the organic component will increase, and the amount of heat-insulating carbonized layer will decrease, making it difficult to exhibit flame retardancy.

  Moreover, 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 coumarone resin, or phenoxy resin is appropriately blended as necessary. Alternatively, additives such as pigments, refractory agents, thixotropic agents, coupling agents, and fluidity improvers may be blended. 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, oxidized polyethylene wax, and organic bentonite-based. Moreover, you may mix | blend hardening accelerators, such as amines, imidazoles, organic phosphines, and Lewis acid, as needed. As a compounding quantity, it is 0.2-5 weight part normally with respect to 100 weight part of epoxy resins. Furthermore, 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. A flame retardant such as antimony, a low stress agent such as silicone oil, a lubricant such as calcium stearate, and the like can be blended.

  The cured product of the present invention can be obtained by curing the epoxy resin composition by a molding method such as casting, compression molding, transfer molding or the like. The temperature at which the cured product is generated is usually 120 to 220 ° C.

Hereinafter, based on a synthesis example, an Example, and a comparative example, this invention is demonstrated concretely.
(Synthesis of polyvalent hydroxy resin)
Synthesis example 1
Into a 1 L 4-neck flask, phenol novolak (manufactured by Showa Polymer; BRG-555, hydroxyl group equivalent of 105 g / eq., Softening point 67 ° C., melt viscosity 0.080 Pa · s at 150 ° C.) as a polyvalent hydroxy compound component. 105 g, 5.3 g of toluene, and 0.055 g (300 ppm) of p-toluenesulfonic acid as an acid catalyst were charged and the temperature was raised to 100 ° C. Next, with stirring at 100 ° C., 73 g (0.7 mol) of styrene was dropped over 3 hours to be reacted. Furthermore, after reacting at 100 ° C. for 2 hours, 0.049 g of 30% Na ₂ CO ₃ was added for neutralization. Next, it was dissolved in 330 g of MIBK and washed 5 times with water at 80 ° C. Subsequently, after MIBK was distilled off under reduced pressure, 170 g of a polyvalent hydroxy resin was obtained. Its hydroxyl equivalent is 178 g / eq. The softening point was 78 ° C., and the melt viscosity at 150 ° C. was 0.13 Pa · s. This resin is referred to as StPN-A.

Synthesis example 2
(Synthesis of epoxy resin)
In a four-neck separable flask, 150 g of StPN-A obtained in Synthesis Example 1, 468 g of epichlorohydrin, and 70 g of diethylene glycol dimethyl ether were added and dissolved by stirring. After uniformly dissolving, maintaining at 65 ° C. under a reduced pressure of 130 mmHg, 70.3 g of 48% aqueous sodium hydroxide solution was added dropwise over 4 hours, and the water and epichlorohydrin distilled off during the addition were separated in a separation tank, and epichlorohydrin was The mixture was returned to the reaction vessel, and water was removed from the system to react. After completion of the reaction, the salt produced by filtration was removed, and after further washing with water, epichlorohydrin was distilled off to obtain 185 g of an epoxy resin (StPNE-A). The epoxy equivalent of the obtained resin was 246 g / eq. The softening point was 56 ° C. and the melt viscosity at 150 ° C. was 0.10 Pa · s.

Examples 1-4, Comparative Examples 1-3
Tables 1-2 show the epoxy resin (StPNE-A) obtained in Synthesis Example 2 above, the epoxy resin shown below, a curing agent, an inorganic filler, triphenylphosphine as a curing accelerator, and other additives. An epoxy resin composition was prepared by kneading at a blending ratio shown in FIG. The numerical value in a table | surface shows the weight part in a mixing | blending.
As a bifunctional crystalline epoxy resin, epoxy resin A: epoxidized product of 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxybiphenyl (YX4000H; epoxy equivalent 195, melting point 105 ° C., 150 ° C. Melt viscosity 0.011 Pa · s, manufactured by Mitsubishi Chemical), epoxy resin B: epoxidized product of 3,3 ′, 5,5′-tetramethyl-4,4′-dihydroxydiphenylmethane (YSLV-80XY; epoxy equivalent 193, melting point) Melt viscosity at 78 ° C. and 150 ° C. 0.008 Pa · s, manufactured by Nippon Steel Chemical Co., Ltd.) was used. Further, as a comparative epoxy resin, an epoxy resin C: o-cresol novolac type epoxy resin (epoxy equivalent 200, softening point 65 ° C., manufactured by Nippon Steel Chemical Co., Ltd.) was used.
As a hardener component, phenol aralkyl resin (PA; MEH-7800SS (Maywa Kasei), OH equivalent 175, softening point 67 ° C.) or phenol novolak (PN; PSM-4261 (Gunei Chemical)), OH equivalent 103, softening Point 82 ° C) was used.

  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 3-4.

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 the potential was measured using a 0.1 mol / L perchloric acid-acetic acid solution.

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

3) Melt viscosity The viscosity was measured at 150 ° C. using a CAP2000H rotational viscometer manufactured by BROOKFIELD.

4) Gel time An epoxy resin composition is added onto a plate of a gelation tester (manufactured by Nisshin Kagaku Co., Ltd.) that has been heated to 175 ° C., and is rotated at a rate of 2 revolutions per second using a fluororesin rod. The gelation time required for stirring and curing of the epoxy resin composition was examined.

5) Spiral flow About spiral flow, the epoxy resin composition was injected into the spiral flow measurement die in accordance with the standard (EMMI-1-66), the injection pressure of spiral flow (150 Kgf / cm ² ), and the setting time of 3 minutes. And the flow length was examined.

6) Linear expansion coefficient (CTE), glass transition point (Tg)
Using a TMA120C type thermomechanical measuring device manufactured by Seiko Instruments Inc., Tg was obtained under the condition of a heating rate of 10 ° C./min. Α1 (CTE of Tg or less) was an average value in the range of 30 to 50 ° C., and α2 (Tg The above CTE) was determined from the average value in the range of Tg plus 20 ° C to 40 ° C.

7) Bending strength and bending elasticity According to JISK6911, it measured at normal temperature by the three-point bending test method.

8) Adhesive strength A molded product of 25 mm x 12.5 mm x 0.5 mm was formed between two copper plates at 175 ° C with a compression molding machine, post-cured at 180 ° C for 12 hours, and then subjected to tensile shear strength. Evaluated by seeking.

9) Water absorption rate The conditions of 25 ° C. and 50% relative humidity were set to the standard state, and the weight change rate after absorbing water for 100 hours under the conditions of 85 ° C. and 85% relative humidity.

10) Flame retardance A test piece having a thickness of 1/16 inch was molded, evaluated according to the UL94V-0 standard, and represented by the total burning time of five test pieces.

Industrial applicability

  The epoxy resin composition of the present invention is excellent in fluidity and curability, and gives a cured product excellent in flame retardancy, moisture resistance and low elasticity, such as sealing of electric / electronic parts, circuit board materials, etc. It is possible to use it suitably for a use. In particular, the fluidity and flame retardancy are excellent, and the use of a flame retardant having an environmental load is made unnecessary or reduced while ensuring excellent moldability.

Claims (4)

In an epoxy resin composition containing an epoxy resin, a phenolic curing agent, and an inorganic filler, the epoxy resin component has an amorphous epoxy resin represented by the following general formula (1) and a melt viscosity of 0 at 150 ° C. A bifunctional crystalline epoxy resin of 0.001 to 0.05 Pa · s is contained, and the content of the amorphous epoxy resin represented by the following general formula (1) is 30 to 70% by weight with respect to the whole epoxy resin. An epoxy resin composition having a bifunctional crystalline epoxy resin content of 30 to 70% by weight and an inorganic filler content of 70 to 95% by weight .

Here, G represents a glycidyl group, R ₁ represents hydrogen or a hydrocarbon group having 1 to 6 carbon atoms, R ₂ represents a substituent represented by the following formula (a), and n represents 1 to 20 Indicates a number. Moreover, p shows the number of 0.3-1.0 .

Here, R < ₃ > shows hydrogen or a C1-C6 hydrocarbon group. The epoxy resin composition according to claim 1, wherein the bifunctional crystalline epoxy resin component is an epoxy resin represented by the following general formula (2).

Here, R _{4 to} R ₁₁ are selected from hydrogen and a hydrocarbon group having 1 to 6 carbon atoms, and all may be the same or different. X represents a single bond, —CH ₂ —, —C (CH ₃ ) ₂ —, —CO—, —O—, —S— or —SO ₂ —. G shows a glycidyl group, m shows the number of 0-3.   The epoxy resin composition according to claim 1, wherein the phenolic curing agent component contains at least one selected from an aralkyl type phenolic curing agent and a novolac type phenolic curing agent. The epoxy resin hardened | cured material formed by hardening | curing the epoxy resin composition in any one of Claims 1-3 .