JP2005344081A - Epoxy resin composition and cured product - Google Patents

Abstract

で表されるユニットを含有し、かつエポキシ当量が２３０〜３００、１５０℃における溶融粘度が０.０２〜０.２Pa・sであるエポキシ樹脂を５０wt％以上含有するエポキシ樹脂を使用し、フェノール系硬化剤成分としてナフトールアラルキル樹脂を含有するフェノール樹脂を使用したエポキシ樹脂組成物。
【選択図】 なしPROBLEM TO BE SOLVED: To show excellent heat resistance and moisture resistance and to exhibit high carbonization yield at the time of combustion, so that excellent flame retardancy is exhibited, and semiconductor encapsulant, molding material, laminated material, powder coating material and adhesive material An epoxy resin composition useful for the above is provided.
In an epoxy resin composition comprising an epoxy resin component, a phenolic curing agent component, and an inorganic filler, the following general formula (1) or (2) is used as the epoxy resin component:
[Chemical 1]

And an epoxy resin containing 50 wt% or more of an epoxy resin having an epoxy equivalent of 230 to 300 and a melt viscosity at 150 ° C. of 0.02 to 0.2 Pa · s. An epoxy resin composition using a phenol resin containing a naphthol aralkyl resin as a curing agent component.
[Selection figure] None

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 moisture resistance, heat resistance, and the like, and a cured product thereof.

  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 with more excellent 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 of its excellent workability and easy mixing with curing agents, additives, 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-63-238,122 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, etc. 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 2004-59792 A JP 4-173831 A JP 2000-129092 JP Japanese Patent Laid-Open No. 3-90075 JP-A-3-281623

  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.

  Accordingly, an object of the present invention is to provide an epoxy that has non-halogen flame retardancy and has excellent properties such as moisture resistance and heat resistance, and is useful for applications such as lamination, molding, casting, and adhesion. It is providing the resin composition and its hardened | cured material.

で表されるユニットを含有し、且つエポキシ当量が２３０〜３００、１５０℃における溶融粘度が０.０２〜０.２Pa・sであるエポキシ樹脂を４０wt％以上含有するものであることを特徴とするエポキシ樹脂組成物である。 That is, the present invention provides an epoxy resin composition comprising an epoxy resin component, a phenolic curing agent component, and an inorganic filler, wherein the epoxy resin component is represented by the following general formula (1) or (2):

And having an epoxy equivalent of 230 to 300 and an epoxy resin having a melt viscosity at 150 ° C. of 0.02 to 0.2 Pa · s in an amount of 40 wt% or more. It is an epoxy resin composition.

で表されるユニットを含有するナフトール樹脂を３０wt％以上含有するものである前記のエポキシ樹脂組成物である。
更に、本発明は、前記のエポキシ樹脂組成物を硬化してなるエポキシ樹脂硬化物である。 In the present invention, the phenolic curing agent component is represented by the following general formula (3) or (4).

It is the said epoxy resin composition which contains 30 wt% or more of naphthol resin containing the unit represented by these.
Furthermore, this invention is an epoxy resin hardened | cured material formed by hardening | curing the said epoxy resin composition.

Hereinafter, the present invention will be described in detail.
The epoxy resin composition of the present invention includes an epoxy resin component, a phenolic curing agent component, and an inorganic filler as essential components and a main component. Advantageously, the above essential components should be contained in an amount of 70 wt% or more, preferably 90 wt% or more.

  As an epoxy resin component, the unit represented by the above general formula (1) or (2) is contained, the epoxy equivalent is 230 to 300, and the melt viscosity at 150 ° C. is 0.02 to 0.2 Pa · s. An epoxy resin containing 40 wt% or more, preferably 70 wt% or more is good. Here, the glycidyl ether group can be substituted with any carbon atom having a replaceable hydrogen in the naphthalenenaphthalene ring, but is preferably in the 1-position or 2-position, and more preferably in the 2-position.

  The epoxy resin component used in the present invention has a glycidyl ether group-substituted naphthalene skeleton and a p-xylylene skeleton represented by the general formula (1) or (2), but instead of the p-xylylene skeleton, methylene, It may contain a skeleton such as ethylidene, isopropylidene or benzylidene. Further, instead of the glycidyl ether group-substituted naphthalene skeleton, a glycidyl group-substituted benzene skeleton, a glycidyl group-substituted methylbenzene skeleton, or the like may be contained. Furthermore, although another type of epoxy compound may be included, it is an essential requirement to contain a unit represented by the above formula (1) or (2), and the desirable content is 40 wt% or more. is there. If it is less than this, the flame retardancy targeted by the present invention will not be sufficiently exhibited.

  The epoxy equivalent of the epoxy resin used for this invention is 230-300, Preferably it is 240-290. If it is smaller than this, the content of the flammable epoxy unit will be high and flame retardancy will not be exhibited, and if it is higher than this, the crosslinking density will be reduced and flame retardancy will not be manifested.

  The epoxy resin used in the present invention has a melt viscosity at 150 ° C. of 0.02 to 0.4 Pa · s, preferably 0.04 to 0.2 Pa · s. When it is lower than this, the heat resistance is lowered, and when it is higher than this, the fluidity is lowered. For the purpose of adjusting the viscosity within this range, the epoxy resin used in the present invention may contain another type of epoxy resin having no unit represented by the above formula (1) or (2). The content is 30 wt% or less. If it is more than this, flame retardancy will decrease.

  The epoxy resin used for this invention can be manufactured by making the naphthol resin used as the precursor react with epichlorohydrin based on the method of normal epoxidation. The precursor naphthol resin can be synthesized according to the production methods described in Patent Documents 5 and 6 and the like.

  That is, a naphthol such as 1-naphthol or 2-naphthol (which may be a mixture of both) and an aromatic cross-linking agent such as o-xylylene dichloride, o-xylylene glycol, o-xylylene glycol dimethyl ether It is good to form the naphthol resin which has a unit represented by the said General formula (3) or (4) by making it react in presence of an acidic catalyst.

  In this reaction, in addition to naphthols, phenol components such as phenol, o-cresol, and naphthol diols may be used in combination. Furthermore, in addition to the aromatic crosslinking agent, paraformaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, o-hydroxybenzaldehyde, divinylbenzenes, bischloromethylbiphenyl, bismethoxymethylbiphenyl, and the like may be used in combination. In the reaction, 0.1 to 0.9 mol of a crosslinking agent is usually used for 1 mol of phenols.

  After completion of the reaction, excess phenols are usually removed from the system by a method such as vacuum distillation. Further, without removing excessive residual phenols out of the system, for example, as described in JP-A-5-148333, by reacting residual naphthols with formaldehyde such as paraformaldehyde, A method of remaining in the system as a dimer and apparently reducing the remaining naphthols may be used. Naphthol is usually removed until the amount remaining in the naphthol resin is 5 wt% or less, preferably 2 wt% or less.

  The naphthol resin thus obtained is suitably used not only as an epoxy resin raw material for the epoxy resin composition of the present invention but also as a curing agent. However, when used as an epoxy resin raw material, the epoxy equivalent and the viscosity at 150 ° C. are within the above range, so that the molecular weight of the naphthol resin should not be made too high, and both ends should be made naphthols as much as possible. is important. That is, the unit represented by the general formula (2) is 30 mol% or more, preferably 50 mol% or more, and the unit represented by the general formula (1) is 70 mol% or less, preferably 50 mol% or less. That's good. For this purpose, it is desirable to adjust the molar ratio of naphthols to the condensing agent and the reaction conditions within the above range.

  The epoxy resin of the epoxy resin composition of the present invention is obtained by reacting the naphthol resin obtained as described above with epichlorohydrin. This reaction can be performed in the same manner as a normal epoxidation reaction. For example, after dissolving naphthol resin in excess epichlorohydrin, reaction is performed 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 0.8-2 mol with respect to 1 mol of hydroxyl groups in a naphthol resin, Preferably it is 0.9-1.2 mol. Moreover, although the usage-amount of epichlorohydrin is used excessively with respect to the hydroxyl group in a naphthol resin, it is 1.5-15 mol normally with respect to 1 mol of hydroxyl groups in a naphthol resin, Preferably it is 2-8 mol.

  Moreover, a quaternary ammonium salt etc. can be added in the case of reaction. Examples of the quaternary ammonium salt include tetramethylammonium chloride, tetrabutylammonium chloride, benzyltriethylammonium chloride, and the like, and the addition amount is preferably 0.1 to 2.0 wt% with respect to the naphthol resin. If the amount is less than this, the effect of adding a quaternary ammonium salt is small. Furthermore, polar solvents such as dimethyl sulfoxide and diglyme may be used, and the addition amount is preferably 10 to 200 wt% with respect to the polyvalent hydroxy resin. If it is less than this, the effect of addition is small, and if it is more than this, the volumetric efficiency is lowered, which is not economical. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene or methyl isobutyl ketone, filtered, washed with water to remove inorganic salts, and then the target epoxy is distilled off. A resin can be obtained.

  The epoxy resin obtained in this way. Although it is an epoxy resin containing the units represented by the general formulas (1) and (2), it may contain a small amount of impurities derived from reaction raw materials and reaction by-products, but those are 20 wt% or less. However, it is preferable to keep it at 10 wt% or less. Moreover, although the thing which the epoxy group in an epoxy resin oligomerized as an ether bond is contained, it may be contained in the range which satisfies the said epoxy equivalent and viscosity.

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, after dissolving the sample 0.5g dioxane 30 ml, after a 1N-KOH was boiled under reflux 10ml was added 30 min, cooled to room temperature, 80% aqueous acetone 100ml was added, potentiometric titration with 0.002 N-AgNO ₃ aqueous solution Is a value obtained by performing

  The epoxy resin composition of the present invention uses, as an essential epoxy resin, an epoxy resin having units represented by the general formulas (1) and (2) as an epoxy resin component, but does not impair the purpose of the present invention. Other epoxy resins can be used in combination. Examples of such an epoxy resin include divalent phenols such as bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2′-biphenol, hydroquinone, and resorcin, tris- (4 -Hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, trivalent or higher phenols such as o-cresol novolak, and halogenated bisphenols such as tetrabromobisphenol A Examples thereof include glycidyl etherification products derived. 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 usually within 50 wt% with respect to the epoxy resin of the present invention.

  Moreover, it is preferable that the epoxy resin composition of this invention uses a naphthol resin which has a unit represented by General formula (3) and (4) as an essential epoxy resin as a phenol type hardening | curing agent component. The naphthol resin as the curing agent component has a hydroxyl group equivalent of 150 to 230, preferably 160 to 220. If it is smaller than this, the content of the epoxy unit in the epoxy resin composition becomes high and flame retardancy is hardly exhibited, and if it is higher than this, the crosslinking density is lowered and flame retardancy is hardly exhibited.

Moreover, as long as the effect of this invention is not inhibited, another phenol resin or another hardening | curing agent can be used, or it can also use together with the said naphthol resin. When other curing agents are used in combination, a phenolic curing agent is preferable, and the blending amount thereof is 70 wt% or less, preferably 60 wt% or less of the total curing agent components.
Specific examples of other phenolic curing agents 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, and hydroquinone. , Divalent phenols such as resorcin, catechol, naphthalenediols, tris- (4-hydroxyphenyl) methane, 1,1,2,2-tetrakis (4-hydroxyphenyl) ethane, phenol novolak, o-cresol novolak , Naphthol novolak, trihydric or higher phenols typified by polyvinylphenol, etc., further phenols, naphthols, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4′-biphenol, 2,2 ′ -Bivalent phenols such as biphenol, hydroquinone, resorcin, catechol, naphthalenediol and formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, divinylbenzene, diisopropenylbenzene, dimethoxymethylbiphenyls, divinylbiphenyl, diisopropenyl Examples thereof include polyhydric phenolic compounds synthesized by reaction with a crosslinking agent such as biphenyls.

  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.

  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, titania, and the like. You may combine these 1 type, or 2 or more types. In particular, those containing fused silica as the main component are preferred, 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 65 to 85 wt%, preferably 70 to 80 wt%. 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 increases, so that the decomposition rate of the organic component increases and the amount of the heat-insulating carbonized layer decreases, making it difficult to exhibit flame retardancy.

  In addition, the epoxy resin composition of the present invention is appropriately blended with an oligomer or a polymer compound such as polyester, polyamide, polyimide, polyether, polyurethane, petroleum resin, indene coumarone resin, or phenoxy resin 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. Further, if necessary, the epoxy 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 the like. A flame retardant such as antimony oxide, 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.

  The epoxy resin composition of the present invention exhibits excellent heat resistance and moisture resistance due to the condensed polycyclic structure of naphthalene. In particular, the naphthalene and aralkyl structures excellent in hydrophobicity have extremely good low hygroscopicity. Furthermore, since it exhibits a high carbonization yield during combustion due to the condensed polycyclic aromatic structure of the naphthalene skeleton, excellent flame retardancy is exhibited. Due to the above-described excellent low moisture absorption, high heat resistance and flame retardancy, when applied to a semiconductor encapsulant, in addition to a significant improvement in solder heat resistance, non-halogen flame retardance can be expected. It can also be suitably used for various molding materials, laminated materials, powder coating materials, adhesive materials, and the like.

Hereinafter, based on an Example and a comparative example, this invention is demonstrated concretely.
Table 1 shows epoxy resins having units represented by the formulas (1) and (2). In addition, for comparison, a biphenyl aralkyl type epoxy resin (BPN) and an o-cresol novolac type epoxy resin (ECN) were also used. Here, the biphenyl aralkyl type epoxy resin has a structure in which the naphthalene ring is a benzene ring and the benzene ring is a biphenyl ring in the general formula (1) or (2). These epoxy resins are all available from Nippon Steel Chemical Co., Ltd.

  A naphthol resin having units represented by the general formulas (3) and (4) was used as a curing agent. SN-170L is one in which the naphthol ring is a 2-naphthol ring in the general formula (3) or (4), and SN-475L is one in which the naphthol ring is a 1-naphthol ring. For comparison, a phenol aralkyl resin (PA: in general formula (3) or (4), the naphthol ring is a phenol ring) and a phenol novolak resin were used as a curing agent.

Examples 1-3, Comparative Example 1
An epoxy resin, a curing agent, a filler (fused silica powder), triphenylphosphine as a curing accelerator, blended as shown in Table 2, kneaded at 110 ° C. for 4 minutes, cooled and pulverized to obtain an epoxy resin composition Obtained. A test piece was prepared using this resin composition, post-cured at 175 ° C. for 12 hours, and then subjected to various physical property tests.

  The glass transition point was calculated | required on the conditions of the temperature increase rate of 7 degree-C / min with the thermomechanical measuring apparatus. The bending test was performed by a three-point bending method for high-temperature bending strength and bending elastic modulus at 240 ° C. The adhesive strength was 25mm x 12.5mm x 0.5mm molded product between two 42 or 194 alloy plates, molded at 175 ° C with a compression molding machine, post-cured at 175 ° C for 12 hours, and then tensile. Evaluation was made by determining the shear strength. The water absorption is the value obtained when a disk having a diameter of 50 mm and a thickness of 3 mm is molded using the epoxy resin composition and moisture-absorbed for 100 hours under conditions of 85 ° C. and 85% RH after post-curing. Flame retardancy was measured by molding a 1/16 inch thick test piece, evaluated according to UL94V-0 standard, and expressed as the total burning time in a test with n = 5. The results are summarized in Tables 3-4.

Examples 4-5, Comparative Example 2
Experiments similar to those in Examples 1 to 3 were performed by changing the curing agent. Table 3 shows the composition and the evaluation results.

Comparative Examples 3-7
The experiment similar to the said Examples 1-3 was performed by changing an epoxy resin or a hardening | curing agent. Table 4 shows the composition and evaluation results.

  From the above, it can be seen that the epoxy resin composition of the present invention exhibits good fluidity even when a large amount of filler is blended, and also exhibits high heat resistance and moisture resistance.

Claims (4)

In an epoxy resin composition comprising an epoxy resin component, a phenolic curing agent component, and an inorganic filler, the epoxy resin component is represented by the following general formula (1) or (2)

And having an epoxy equivalent of 230 to 300 and an epoxy resin having a melt viscosity at 150 ° C. of 0.02 to 0.2 Pa · s in an amount of 40 wt% or more. Epoxy resin composition. The phenolic curing agent component is represented by the following general formula (3) or (4)

The epoxy resin composition according to claim 1, wherein the epoxy resin composition contains 30 wt% or more of a naphthol resin containing a unit represented by:   The epoxy resin composition according to claim 1 or 2, wherein the content of the inorganic filler is 65 to 85 wt%.   An epoxy resin cured product obtained by curing the epoxy resin composition according to claim 1.