JP4257985B2 - Epoxy resin composition - Google Patents

Description

【０００９】
（式中、Ｒ１及びＲ２は、水素原子、炭素数１〜４のアルキル基又は炭素数１〜４のアルコキシ基を表す。）
以下、本発明について詳細に説明する。
【００１０】
本発明で用いられる、ａ）エポキシ樹脂については特に限定はないが、融点が５０〜１２０℃で、１分子当たり平均２個以上のエポキシ基を含むエポキシ樹脂が好適に使用される。例えば、ビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビスフェノールＳ型エポキシ樹脂、ダイマー酸グリシジルエステル型エポキシ樹脂、ポリアルキレンエーテル型エポキシ樹脂、ビフェニル型エポキシ樹脂、ジシクロペンタジエン型エポキシ樹脂、ナフトール型エポキシ樹脂、ナフタレン型エポキシ樹脂、脂環式エポキシ樹脂、複素環含有エポキシ樹脂、グリシジルアミン型エポキシ樹脂等が挙げられ、これらを単独の他、２種以上混合して用いても良い。さらには難燃化のためブロム化エポキシ樹脂を使用することもできる。
【００１１】
本発明で用いられる、ｂ）フェノール樹脂系硬化剤については特に限定はないが、融点が５０〜１２０℃で、１分子当たり平均２個以上のフェノール性水酸基を有するフェノール系樹脂が好適に使用される。例えば、フェノールノボラック樹脂、オルトクレゾールノボラック樹脂、パラクレゾールノボラック樹脂、ターシャリーブチルフェノールノボラック樹脂、トリフェノールメタン樹脂、キシリレン変性ノボラック樹脂、フェノールアラルキル樹脂、ナフタレン環含有フェノール樹脂、ジシクロペンタジエン含有フェノール樹脂、テルペン環含有フェノール樹脂、ポリパラビニルフェノール等が挙げられる。また、硬化剤の添加量は、その使用目的や硬化特性、硬化剤の種類により適宜決定され特に限定するものではないが、硬化物の耐水性、耐熱性を考慮すると好ましくはエポキシ樹脂１当量に対して０．５〜１．５当量の範囲で添加される。
【００１２】
本発明で用いられる、ｃ）Ｎ−ベンジルピペラジン類については前述の式（１）で表されるものであり、式中、Ｒ１及びＲ２は水素原子、炭素数１〜４のアルキル基又は炭素数１〜４アルコキシ基を表す。アルキル基又はアルコキシ基の炭素数が４を越えると、本発明の効果である硬化物の耐水性及び耐熱性への優れた性能の発現が難しくなる恐れがある。ｃ）Ｎ−ベンジルピペラジン類については、具体的には、N−ベンジルピペラジン、N−（メチルベンジル）ピペラジン、N−（ジメチルベンジル）ピペラジン、N−（トリメチルベンジル）ピペラジン、N−（エチルベンジル）ピペラジン、N−（ジエチルベンジル）ピペラジン、N−（メトキシベンジル）ピペラジン、N−ベンジル（２−メチル）ピペラジン、N−ベンジル（３−メチル）ピペラジン、N−ベンジル（２，６−ジメチル）ピペラジン、N−ベンジル（３，５−ジメチル）ピペラジン等が挙げられる。これらN−ベンジルピペラジン類は単一化合物で用いる他、２種以上混合して用いても良い。また、N−ベンジルピペラジン類はそのままでも良好な保存安定性を示すが、さらに優れた保存安定性を得るには塩の状態にするのが好ましい。N−ベンジルピペラジン類の塩について、その対アニオンは有機酸あるいはテトラ置換有機ボレートである。特に限定するものではないが、具体的には、安息香酸、フタル酸、トリメリット酸、ピロメリット酸、無水トリメリット酸、無水ピロメリット酸、サリチル酸、（オルト、メタ、及びパラ）ヒドロキシ安息香酸、酢酸、プロピオン酸、マロン酸、コハク酸、アジピン酸、フマル酸、マレイン酸、シアヌル酸よりなるアニオン、及びテトラフェニルボレート、テトラ（４−メチルフェニル）ボレート、テトラ（２，４−ジメチルフェニル）ボレート、テトラ（４−メトキシフェニル）ボレート等が例示される。一方、エポキシ樹脂組成物への添加量は、特に限定するものではないが、速硬化性、保存安定性、硬化物の樹脂物性等を考慮すると好ましくはエポキシ樹脂１００重量部に対して０．２〜１０重量部、さらに好ましくは０．５〜５重量部である。さらに、本発明の硬化促進剤であるＮ−ベンジルピペラジン類あるいはその塩に、該化合物の特性を損なわない範囲で、公知の硬化促進剤を併用することも可能である。
【００１３】
本発明のエポキシ樹脂組成物は、本発明の目的を損なわない範囲で必要に応じて通常のエポキシ樹脂組成物に用いられている他の添加剤、例えば、充填剤、有機溶剤、難燃剤、染料、変色防止剤、酸化防止剤、離型剤、可撓性付与剤、液状ゴム、レべリング剤、粘着付与剤、カップリング剤、消泡剤、反応性又は非反応性希釈剤等を適宜に配合することができる。例えば、充填剤としては、結晶性シリカ、溶融シリカ、アルミナ、珪酸ジルコニウム、石英粉、鉱物性珪酸塩、炭酸カルシウム、硫酸バリウム、カーボンブラック、コールタール、ガラス繊維、アスベスト繊維、ホウ素繊維、炭素繊維、セルロース粉、アスベスト粉、スレート粉、石膏、エアロゾル、二酸化チタン、グラファイト、酸化鉄、アルミニウム粉等を挙げることができるが、これらに特に限定されるものではない。
【００１４】
本発明のエポキシ樹脂組成物は、前記のａ）エポキシ樹脂、ｂ）フェノール樹脂系硬化剤、及びｃ）式（１）で示されるＮ−ベンジルピペラジン類あるいはその塩、さらに必要に応じて充填剤や各種添加剤を、三本ロール、ニーダー、万能攪拌機、ボールミル、プラネタリミキサー、ホモジナイザー、ホモディスパーザー等により混練することにより得ることができる。さらに、こうして得られたエポキシ樹脂組成物を、従来から用いられている成形法、例えば、トランスファー成形、インジェクション成形、ディスペンサー、注型法等により加熱成形することで所望の成形材料を得ることができる。
【００１５】
加熱成形時の温度については特に規定はないが、本発明のエポキシ樹脂組成物の必須成分であるN−ベンジルピペラジン類あるいはその塩は優れた速硬化性を有しているため比較的低温でも硬化が可能である。最適硬化温度はエポキシ樹脂、及び硬化剤等その他配合される種類により適宜決定されるものではあるが、特に１００〜２００℃の範囲で優れた硬化樹脂物性を与えることができる。
【００１６】
【実施例】
以下、実施例、比較例に基づいて具体的に説明するが、本発明はこれら実施例のみに限定されるものではない。
【００１７】
実施例、比較例で得られたエポキシ樹脂組成物は以下の方法により評価した。
【００１８】
＜ゲルタイム＞：１５０℃の熱板上に試料を載せ、ニードルで攪拌を行いながら流動性を失いゲル化するまでの時間を測定した。
【００１９】
＜ポットライフ＞：密栓した容器中にエポキシ樹脂組成物を４０℃で保存し、これを経時的に取り出し、１５０℃でのゲルタイムが保存開始前のゲルタイムの１／２となる時間をポットライフとした。
【００２０】
＜熱変形温度＞：ＪＩＳ Ｋ−７２０７（１９９７）に準拠した試験片の規格、試験条件において、エポキシ樹脂組成物を１００℃で２時間さらに１５０℃で２時間熱硬化させた硬化物について熱変形温度を測定した。
【００２１】
＜電気物性及び耐水性＞：エポキシ樹脂組成物を１０×１０×０．２ｃｍのサイズのモールドに入れ、１５０℃、３時間の条件でホットプレスにて加圧、熱硬化させ試験片を作成した。こうして得られた試験片の体積抵抗値を測定した。さらに、試験片を１２０℃の高圧水蒸気下、２０時間処理（プレッシャークッカーテスト：以下ＰＣＴと略す）した後の体積抵抗値により耐水性を評価した。
【００２２】
実施例１
エポキシ樹脂として軟化点が７０℃、エポキシ当量が１９８のオルトクレゾールノボラックエポキシ樹脂（日本化薬（株）製ＥＯＣＮ−１０２０−７０）を１００重量部、硬化剤として軟化点が８０℃、フェノール当量１１０のフェノールノボラック樹脂（群栄化学（株）製ＰＳＭ−４２６１）を５５重量部、硬化促進剤としてＮ−ベンジルピペラジンのコハク酸塩を２．０重量部用い、これらを常温、乳鉢中で粉砕、混合した。こうして得られた混合物をモールド内に入れ８０℃、５分間、７０ｋｇ／ｃｍ²の条件で溶融混合プレスし、冷却後粉砕しエポキシ樹脂組成物を得た。得られたエポキシ樹脂組成物のゲルタイム（速硬化性）、ポットライフ（保存安定性）、硬化物の熱変形温度（耐熱性）、ＰＣＴ前後の体積抵抗値（電気物性及び耐水性）の測定を行い、この結果を表１に示した。
【００２３】
【表１】

【００２４】
実施例２〜実施例４、比較例１〜比較例５
硬化促進剤として、それぞれ表１に示した硬化促進剤を所定量用いた以外は実施例１と同様の方法によりエポキシ樹脂組成物を得、この評価結果を表１に示した。
【００２５】
実施例５
エポキシ樹脂として軟化点が１０７℃、エポキシ当量が１９３のビフェニル型エポキシ樹脂（油化シェルエポキシ（株）製ＹＸ４０００Ｈ）を１００重量部、硬化剤として軟化点が７６℃、フェノール当量１７４のパラキシリレンフェノール樹脂（三井化学（株）製ミレックスＸＬＣ−２２５−ＬＬ）を９０重量部、硬化促進剤としてＮ−ベンジルピペラジンのコハク酸塩を３．０重量部用い、これらを実施例１と同様の方法で混合しエポキシ樹脂組成物を得た。得られたエポキシ樹脂組成物のゲルタイム、ポットライフ、硬化物の耐熱性、電気物性及び耐水性の評価結果を表２に示した。
【００２６】
【表２】

【００２７】
実施例６〜実施例７、比較例６〜比較例８
硬化促進剤として、それぞれ表２に示した硬化促進剤を所定量用いた以外は実施例５と同様の方法によりエポキシ樹脂組成物を得、この評価結果を表２に示した。
【００２８】
【本発明の効果】
本発明のＮ−ベンジルピペラジン類の塩を含むエポキシ樹脂組成物は、優れた速硬化性、保存安定性を有するので、冷凍保存が不要になり生産性が向上する効果がある。さらに、熱硬化物はＰＣＴ後の体積抵抗値が高く耐水性に優れていると共に、耐熱性も優れているので、半導体封止材をはじめとした電子部品材料、あるいは積層板材料等に好適に用いられる。[0001]
[Technical field to which the invention belongs]
The present invention relates to an epoxy resin composition, and more specifically, an epoxy resin composition having excellent quick curability and storage stability, and giving both thermoresistance and excellent water resistance to heat cured products. It is about.
[0002]
[Prior art]
There are various properties required for the curing accelerator in the epoxy resin composition, and among them, storage stability can be obtained over a long period of time even if the curing accelerator is mixed with a compound mixed with the epoxy resin and the curing agent in advance. There is a demand for the property that a cured resin can be obtained quickly upon heating, that is, the potential. In response to this requirement, a method of improving amines and the like conventionally used as curing accelerators by converting them to salts with organic acids or borates is generally used. Organic acid or borate salt of 8-diazabicyclo [5,4,0] -7-undecene (hereinafter abbreviated as DBU) (for example, JP 59-75923 A, JP 7-188395 A), 2 -Organic salts of ethyl-4-methylimidazole and the like are shown.
[0003]
On the other hand, the properties required for thermosets include heat resistance, water resistance, electrical properties, mechanical properties, and the like, and it is said that the curing accelerator greatly affects these properties. In particular, in electrical / electronic material applications such as semiconductor encapsulants, there is a strong demand for curing accelerators to have both excellent water resistance and heat resistance in addition to electrical properties. To date, DBU, imidazoles, triphenylphosphine, and phosphonium borate salts (for example, JP-A-9-208669) have been frequently used for electrical and electronic materials.
[0004]
[Problems to be solved by the invention]
However, when a curing accelerator such as that described above is used, it has excellent rapid curability and storage stability, and also provides the epoxy resin composition with both excellent water resistance and heat resistance against the thermoset. Is very difficult. The organic acid salt and borate salt of DBU have good fast curability and storage stability, and the thermoset has good water resistance, but has a problem of low heat resistance. Although organic acid salts of imidazoles are excellent in fast curability, storage stability, and heat resistance of thermosets, they have a problem of low water resistance. Although triphenylphosphine is excellent in both water resistance and heat resistance of the thermosetting product, there is a problem that storage stability is poor. Although the phosphonium borate salt is excellent in both water resistance and heat resistance of the thermoset, it is poor in rapid curability and requires long time heating at high temperature for curing.
[0005]
The present invention has been made in view of the above problems, and its purpose is to have excellent fast curability and storage stability and to provide a thermoset with both excellent water resistance and heat resistance. It is to provide an epoxy resin composition.
[0006]
[Means for Solving the Problems]
As a result of intensive studies on the problems as described above, the inventors of the present invention have found that specific piperazine derivative salts provide excellent rapid curability and storage stability to the epoxy resin composition, and have excellent water resistance. The present invention has been completed by finding out that the heat-cured product is compatible with heat resistance.
[0007]
That is, the present invention comprises an epoxy resin composition comprising a) an epoxy resin, b) a phenol resin-based curing agent, and c) an N-benzylpiperazine represented by the formula (1) or a salt thereof. It is.
[0008]
[Chemical formula 2]

[0009]
(In formula, R1 and R2 represent a hydrogen atom, a C1-C4 alkyl group, or a C1-C4 alkoxy group.)
Hereinafter, the present invention will be described in detail.
[0010]
The a) epoxy resin used in the present invention is not particularly limited, but an epoxy resin having a melting point of 50 to 120 ° C. and an average of 2 or more epoxy groups per molecule is preferably used. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, dimer acid glycidyl ester type epoxy resin, polyalkylene ether type epoxy resin, biphenyl type epoxy resin, dicyclopentadiene type epoxy resin, naphthol type epoxy Examples thereof include resins, naphthalene type epoxy resins, alicyclic epoxy resins, heterocyclic ring-containing epoxy resins, glycidylamine type epoxy resins and the like, and these may be used alone or in combination. Furthermore, brominated epoxy resins can be used for flame retardancy.
[0011]
The b) phenolic resin curing agent used in the present invention is not particularly limited, but a phenolic resin having a melting point of 50 to 120 ° C. and an average of 2 or more phenolic hydroxyl groups per molecule is preferably used. The For example, phenol novolak resin, orthocresol novolak resin, paracresol novolak resin, tertiary butylphenol novolak resin, triphenolmethane resin, xylylene modified novolak resin, phenol aralkyl resin, naphthalene ring-containing phenol resin, dicyclopentadiene-containing phenol resin, terpene Examples thereof include ring-containing phenol resins and polyparavinylphenol. Moreover, the addition amount of the curing agent is appropriately determined depending on the purpose of use, curing characteristics, and the type of the curing agent, and is not particularly limited. However, considering the water resistance and heat resistance of the cured product, it is preferably 1 equivalent of epoxy resin. It is added in the range of 0.5 to 1.5 equivalents.
[0012]
C) N-benzylpiperazines used in the present invention are those represented by the above formula (1), wherein R1 and R2 are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a carbon number. 1-4 represents an alkoxy group. If the alkyl group or alkoxy group has more than 4 carbon atoms, it may be difficult to achieve excellent performance of the cured product in terms of water resistance and heat resistance, which is an effect of the present invention. c) For N-benzylpiperazines, specifically, N-benzylpiperazine, N- (methylbenzyl) piperazine, N- (dimethylbenzyl) piperazine, N- (trimethylbenzyl) piperazine, N- (ethylbenzyl) Piperazine, N- (diethylbenzyl) piperazine, N- (methoxybenzyl) piperazine, N-benzyl (2-methyl) piperazine, N-benzyl (3-methyl) piperazine, N-benzyl (2,6-dimethyl) piperazine, N-benzyl (3,5-dimethyl) piperazine and the like can be mentioned. These N-benzylpiperazines may be used as a single compound or in combination of two or more. Further, N-benzylpiperazines show good storage stability as they are, but in order to obtain further excellent storage stability, it is preferably in a salt state. For the salts of N-benzylpiperazines, the counter anion is an organic acid or a tetra-substituted organic borate. Specific examples include, but are not limited to, benzoic acid, phthalic acid, trimellitic acid, pyromellitic acid, trimellitic anhydride, pyromellitic anhydride, salicylic acid, (ortho, meta, and para) hydroxybenzoic acid , Anion consisting of acetic acid, propionic acid, malonic acid, succinic acid, adipic acid, fumaric acid, maleic acid, cyanuric acid, and tetraphenylborate, tetra (4-methylphenyl) borate, tetra (2,4-dimethylphenyl) Examples include borate and tetra (4-methoxyphenyl) borate. On the other hand, the amount of addition to the epoxy resin composition is not particularly limited, but is preferably 0.2 with respect to 100 parts by weight of the epoxy resin in view of fast curability, storage stability, resin physical properties of the cured product, and the like. -10 parts by weight, more preferably 0.5-5 parts by weight. Furthermore, a known curing accelerator can be used in combination with the N-benzylpiperazines or salts thereof, which are the curing accelerator of the present invention, as long as the properties of the compound are not impaired.
[0013]
The epoxy resin composition of the present invention may be added to other additives used in ordinary epoxy resin compositions as necessary within a range that does not impair the object of the present invention, such as fillers, organic solvents, flame retardants, and dyes. , Anti-discoloring agent, antioxidant, release agent, flexibility imparting agent, liquid rubber, leveling agent, tackifier, coupling agent, antifoaming agent, reactive or non-reactive diluent, etc. Can be blended. Examples of fillers include crystalline silica, fused silica, alumina, zirconium silicate, quartz powder, mineral silicate, calcium carbonate, barium sulfate, carbon black, coal tar, glass fiber, asbestos fiber, boron fiber, carbon fiber. , Cellulose powder, asbestos powder, slate powder, gypsum, aerosol, titanium dioxide, graphite, iron oxide, aluminum powder and the like, but are not particularly limited thereto.
[0014]
The epoxy resin composition of the present invention comprises a) an epoxy resin, b) a phenol resin-based curing agent, and c) an N-benzylpiperazine represented by the formula (1) or a salt thereof, and further, if necessary, a filler. And various additives can be obtained by kneading with a three roll, kneader, universal stirrer, ball mill, planetary mixer, homogenizer, homodisperser or the like. Furthermore, a desired molding material can be obtained by heat-molding the epoxy resin composition thus obtained by a conventionally used molding method such as transfer molding, injection molding, dispenser, or casting method. .
[0015]
There is no particular restriction on the temperature at the time of heat molding, but N-benzylpiperazines or salts thereof, which are essential components of the epoxy resin composition of the present invention, have excellent fast curability and therefore cure even at relatively low temperatures. Is possible. The optimum curing temperature is appropriately determined depending on the epoxy resin, the curing agent, and other types to be blended, but can provide excellent cured resin properties particularly in the range of 100 to 200 ° C.
[0016]
【Example】
Hereinafter, although it demonstrates concretely based on an Example and a comparative example, this invention is not limited only to these Examples.
[0017]
The epoxy resin compositions obtained in Examples and Comparative Examples were evaluated by the following methods.
[0018]
<Gel time>: A sample was placed on a hot plate at 150 ° C., and while stirring with a needle, the time until it lost fluidity and gelled was measured.
[0019]
<Pot life>: The epoxy resin composition is stored at 40 ° C. in a sealed container, taken out with time, and the time at which the gel time at 150 ° C. is ½ of the gel time before the start of storage is defined as the pot life. did.
[0020]
<Heat deformation temperature>: Thermal deformation of a cured product obtained by thermosetting an epoxy resin composition at 100 ° C. for 2 hours and further at 150 ° C. for 2 hours under the test piece standard and test conditions in accordance with JIS K-7207 (1997). The temperature was measured.
[0021]
<Electrical properties and water resistance>: An epoxy resin composition was put into a mold having a size of 10 × 10 × 0.2 cm, and a test piece was prepared by pressurizing and thermosetting with a hot press at 150 ° C. for 3 hours. . The volume resistance value of the test piece thus obtained was measured. Furthermore, water resistance was evaluated by the volume resistance value after the test piece was treated under high-pressure steam at 120 ° C. for 20 hours (pressure cooker test: hereinafter abbreviated as PCT).
[0022]
Example 1
100 parts by weight of orthocresol novolac epoxy resin (EOCN-1020-70 manufactured by Nippon Kayaku Co., Ltd.) having a softening point of 70 ° C. and an epoxy equivalent of 198 as an epoxy resin, and a softening point of 80 ° C. and a phenol equivalent of 110 as a curing agent 55 parts by weight of phenol novolac resin (PSM-4261 manufactured by Gunei Chemical Co., Ltd.) and 2.0 parts by weight of succinate of N-benzylpiperazine as a curing accelerator, these were pulverized in a mortar at room temperature. Mixed. The mixture thus obtained was put in a mold, melt mixed and pressed at 80 ° C. for 5 minutes at 70 kg / cm ² , cooled and pulverized to obtain an epoxy resin composition. Measurement of gel time (fast curing), pot life (storage stability), heat distortion temperature (heat resistance) of cured product, volume resistance value (electrical properties and water resistance) before and after PCT of the obtained epoxy resin composition The results are shown in Table 1.
[0023]
[Table 1]

[0024]
Examples 2 to 4, Comparative Examples 1 to 5
An epoxy resin composition was obtained in the same manner as in Example 1 except that a predetermined amount of each of the curing accelerators shown in Table 1 was used as the curing accelerator, and the evaluation results are shown in Table 1.
[0025]
Example 5
100 parts by weight of biphenyl type epoxy resin (YX4000H manufactured by Yuka Shell Epoxy Co., Ltd.) having a softening point of 107 ° C. and an epoxy equivalent of 193 as an epoxy resin, paraxylylene having a softening point of 76 ° C. and a phenol equivalent of 174 as a curing agent 90 parts by weight of phenol resin (Mirex XLC-225-LL manufactured by Mitsui Chemicals, Inc.) and 3.0 parts by weight of succinate of N-benzylpiperazine as a curing accelerator were used, and these were used in the same manner as in Example 1. To obtain an epoxy resin composition. Table 2 shows the evaluation results of gel time, pot life, heat resistance of the cured product, electrical properties, and water resistance of the obtained epoxy resin composition.
[0026]
[Table 2]

[0027]
Example 6 to Example 7, Comparative Example 6 to Comparative Example 8
An epoxy resin composition was obtained in the same manner as in Example 5 except that a predetermined amount of each of the curing accelerators shown in Table 2 was used as the curing accelerator, and the evaluation results are shown in Table 2.
[0028]
[Effect of the present invention]
The epoxy resin composition containing the salt of the N-benzylpiperazines of the present invention has excellent rapid curability and storage stability, and thus has the effect of eliminating the need for frozen storage and improving productivity. Furthermore, since the thermoset has a high volume resistance after PCT and is excellent in water resistance, it is also excellent in heat resistance. Therefore, it is suitable for electronic component materials such as semiconductor encapsulating materials or laminated board materials. Used.

Claims (2)

An epoxy resin composition comprising a) an epoxy resin, b) a phenol resin-based curing agent, and c) a salt of N-benzylpiperazine represented by the formula (1).

(In the formula, R1 and R2 represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. The counter anion of the salt of N-benzylpiperazine is phthalic acid or trimellitic acid. , Pyromellitic acid, trimellitic anhydride, pyromellitic anhydride, salicylic acid, (ortho, meta, and para) hydroxybenzoic acid, propionic acid, malonic acid, succinic acid, adipic acid, fumaric acid, or cyanuric acid , And tetraphenylborate, tetra (4-methylphenyl) borate, tetra (2,4-dimethylphenyl) borate, tetra (4-methoxyphenyl) borate .) The salt of N-benzylpiperazine is selected from the group consisting of N-benzylpiperazine / phthalic acid, N-benzylpiperazine / trimellitic acid, N-benzylpiperazine / succinic acid, and N-benzylpiperazine / tetraphenylborate. The epoxy resin composition according to claim 1 .