JP3944765B2 - Epoxy resin, epoxy resin composition and cured product thereof - Google Patents

Description

（式中、Ｒ _１ 〜Ｒ₃は、互いに同一でも異なっていてもよい水素原子、メチル基、
フェニルエチリデン基、またはフェニル基を表わし、且つ、Ｒ₁〜Ｒ₃の少なくとも1つがメチル基、フェニル基、フェニルエチリデン基を表し、Ｒ _７ は水素原子又はメチル基を表し、ｑは平均値で０から１０の値を表わす。）で表されるエポキシ樹脂を提供する。
【０００８】
また、本発明は、一般式（３）
【化７】

（式中、Ｒ _１ 〜Ｒ₃は、互いに同一でも異なっていてもよい水素原子、メチル基、
フェニルエチリデン基、またはフェニル基を表わし、且つ、Ｒ₁〜Ｒ₃の少なくとも1つがメチル基、フェニル基、フェニルエチリデン基を表わす。）で表される芳香族ジオール化合物とエピハロヒドリンとを反応させて得られるエポキシ樹脂をも提供する。
【０００９】
また、本発明は、上記のエポキシ樹脂と硬化剤とを必須成分とするエポキシ樹脂組成物、上記のエポキシ樹脂と硬化剤を必須成分とし、かつハロゲン化合物を実質的に含有しないことを特徴とする難燃性エポキシ樹脂組成物、または、前記のエポキシ樹脂組成物を硬化して得られる硬化物、さらに下記、一般式（３）
【化８】

（式中、Ｒ _１ 〜Ｒ ₃ は、互いに同一でも異なっていてもよい水素原子、メチル基、
フェニルエチリデン基、またはフェニル基を表わし、且つ、Ｒ ₁ 〜Ｒ ₃ の少なくとも 1 つがメチル基、フェニル基、フェニルエチリデン基を表し、Ｒ _７ は水素原子又はメチル基を表わす。）で表される芳香族ジオール化合物をも提供する。
【００１０】
本発明に用いるエポキシ樹脂としては、例えば、下記構造式（５）
【化９】

で示される結節基を介して、少なくとも1つがメチル基、フェニル基、またはフェニルエチリデン基で置換されているフェニルグリシジルエーテル残基が結合している化合物が挙げられる。
【００１１】
本発明の一般式（１）で表わされるエポキシ樹脂としては、例えば、構造式（２）で表わされるエポキシ樹脂が挙げられる。
【００１２】
【化１０】

【００１３】
前記のエポキシ樹脂は、例えば芳香族性水酸基含有化合物と芳香族骨格含有ケトン類または芳香族骨格含有アルデヒド類等の芳香族骨格含有カルボニル化合物との縮合物と、エピハロヒドリンとを反応させて得られる。
【００１６】
また、本発明のエポキシ樹脂は、耐熱性、および粘度が低く無機充填材の充填率を上げることができ、耐湿性、難燃性といった半導体封止材料としての性能に優れることから、１５０℃におけるＩＣＩ粘度が、５ｄＰａ・ｓ以下が好ましく、３ｄＰａ・ｓ以下がより好ましい。
【００１７】
本発明に用いられる芳香族性水酸基含有化合物と芳香族骨格含有カルボニル化合物との縮合物の製造方法について説明する。該縮合物は、フェノール類とビフェニルアルデヒド類等の芳香族骨格含有カルボニル化合物を縮合反応させることで得ることができる。
【００１８】
次いで、一般式（４）で表わされる芳香族性水酸基含有化合物と芳香族骨格含有ケトン類または芳香族骨格含有アルデヒド類等の芳香族骨格含有カルボニル化合物との縮合物と、エピハロヒドリンとを反応させて得られるエポキシ樹脂について説明する。
【００１９】
前記の芳香族性水酸基含有化合物と芳香族骨格含有カルボニル化合物との縮合物（以下縮合物と記す。）としては、下記構造式（５）
【化１１】

で示される結節基を介して、２個結合された構造をもつフェノール化合物であれば特に構造が限定されるものではない。
【００２０】
上記縮合物としては、例えば下記一般式（３）で表される本発明の芳香族ジオール化合物が挙げられる。
【化１２】

（式中、Ｒ _１ 〜Ｒ₃は、互いに同一でも異なっていてもよい水素原子、メチル基、
フェニルエチリデン基、またはフェニル基を表わし、且つ、Ｒ₁〜Ｒ₃の少なくとも1つがメチル基、フェニル基、フェニルエチリデン基を表わす。）
【００２３】
ここで用いられる芳香族性水酸基含有化合物類は、芳香族性水酸基を１分子中に１個もつ芳香族性化合物であれば特に限定されることはないが、例示するならばクレゾール、ジメチルフェノール（キシレノール）、トリメチルフェノール、フェニルフェノールなどが挙げられる。これらのなかでも、２、６−キシレノール、２、４−キシレノール等に代表されるアルデヒド官能基との縮合反応性に関して１官能性を示すフェノール化合物を用いることが、後述するようにビスフェノール化合物の収率を高めやすいことから好ましい。
フェノール等に代表されるアルデヒド官能基との縮合反応性に関して多官能性を示すフェノール化合物を用いるとノボラック化し、２官能成分のみを取り出すためには、再結晶等の精製を繰り返す必要があり収率が著しく低下する。また、難燃性の観点からは、メチル基または縮合環を含有した化合物が好ましく、それらの中でも更難燃性が著しく向上することから２、６−キシレノール、２、４−キシレノールが特に好ましい。また、これらのなかから２種類以上を併用しても構わない。
【００２４】
したがって、難燃性と製造上の簡便さを併せて考慮すると、芳香族性水酸基含有化合物としては２、６−キシレノールや２、４−キシレノールを用いることが好ましく、中でも２，６−キシレノールが特に好ましい。
【００２５】
また、芳香族骨格含有カルボニル化合物としては、芳香族骨格含有ケトン類、芳香族骨格含有アルデヒド類が挙げられる。中でも、フェノール類との反応性優れている点から芳香族骨格含有アルデヒド類が好ましい。これら芳香族アルデヒド基を含有した化合物は、例示するならば、４−ビフェニルアルデヒドが挙げられる。
【００２６】
上述の一般式（１）で表わされる芳香族性水酸基含有化合物とビフェニル骨格含有アルデヒド化合物との縮合物の中でも、例えば、下記構造式（９）〜（１２）で示されるフェノール類が、得られるエポキシ樹脂として好ましい。
【化１３】

【００２７】
これらの芳香族ジオール化合物がの中でも、難燃性が飛躍的に向上することから分子内に２，６−キシレノール構造とビフェニル構造を有する前記構造式（９）の芳香族ジオール化合物が特に好ましい。
【００２８】
これらの芳香族ジオール化合物とエピハロヒドリンから得られるエポキシ樹脂は、耐熱性、および粘度が低く無機充填材の充填率を上げることができ、耐湿性、難燃性といった半導体封止材料としての性能に優れることから、１５０℃におけるＩＣＩ粘度が、５ｄＰａ・ｓ以下が好ましく、更に３ｄＰａ・ｓ以下がより好ましい。
【００２９】
次いで、本発明に用いられる芳香族性水酸基含有化合物と芳香族骨格含有カルボニル化合物との縮合物の製造方法について説明する。該縮合物は、フェノール類とビフェニルアルデヒド類等の芳香族骨格含有カルボニル化合物を縮合反応させることで得ることができる。
【００３０】
この縮合反応は通常、フェノール類とビフェニルアルデヒド類を前者／後者＝２／１〜３０／１（モル比率）の仕込み、酸触媒の存在下でおこなわれる。また必要に応じて、有機溶媒を用いても構わない。仕込み比率としては、フェノールやクレゾール等の前記カルボニル化合物類との縮合反応に関して２官能以上の性質を有するフェノール類を用いた場合は、フェノール類／前記カルボニル化合物類（モル比率）を４倍以上に高めた方が、目的のビスフェノール化合物の収率が高まることが好ましい。２、６−キシレノールや２、６−キシレノールなどの前記カルボニル化合物類との縮合反応に関して、１官能性を示すフェノール類を用いた場合は、フェノール類／前記カルボニル化合物類＝２〜４（モル比率）でも目的のビスフェノール化合物が高収率で得ることが可能である。また上記酸触媒としては、通常、フェノール類と前記カルボニル化合物類との縮合反応に用いられる触媒であれば特に限定されるもこではないが、例示するならば塩酸、硫酸、無水硫酸、ｐ−トルエンスルホン酸、メタンスルホン酸、トリフルオロメタンスルホン酸、シユウ酸、ギ酸、リン酸、トリクロロ酢酸、トリフルオロ酢酸等が挙げられる。触媒の添加量としては、フェノール類とアルデヒド類の合計重量に対して、０．０１〜５重量％の範囲で用いられる。また上記有機溶媒としては、ベンゼン、トルエン、キシレンなどの芳香族性有機溶媒や、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノンなどのケトン系有機溶媒、メタノール、エタノール、イソプロピルアルコール、ノルマルブタノールなどのアルコール系有機溶媒等をもちいることができ、用いる原料や生成物の溶解度などの性状や反応条件や経済性等を考慮して適宜選択すればよい。有機溶媒の量としては、フェノール類とアルデヒド類の合成重量に対して、１０〜５００重量％の範囲で用いられる。反応条件としては、通常、室温から２００℃、好ましくは、５０〜１５０℃の温度にて、０．５〜３０時間程度加熱攪拌すればよい。反応終了後、反応生成物が容易に結晶化する場合は、反応液を冷却して晶析によって、目的物を単離させればよい。その際、必要に応じて、濃縮、中和、洗浄、再結晶等の作業をおこなってもよい。反応生成物が結晶化しづらいものでは、濃縮物を再結晶或いは再沈などによって精製して目的物の純度を高めればよい。
【００３１】
次いで、芳香族性水酸基含有化合物と芳香族骨格含有カルボニル化合物との縮合物類、例えば上記一般式（４）で表される芳香族ジオール化合物から本発明のエポキシ樹脂を得る方法について説明する。本発明のエポキシ樹脂を得る方法としてはそれ自体公知の方法が採用できが、例えば、前記で得られた一般式（４）で表されるビスフェノール化合物とエピクロルヒドリン、エピブロムヒドリン、メチルエピクロルヒドリン等のエピハロヒドリンの溶解混合物に水酸化ナトリウム、水酸化カリウム等のアルカリ金属水酸化物を添加し、または添加しながら２０〜１２０℃で１〜１０時間反応させることにより本発明のエポキシ樹脂を得ることが出来る。
【００３２】
エピハロヒドリンの添加量は、原料の芳香族ジオール化合物中の水酸基１当量に対して、通常０．３〜２０当量の範囲が用いられる。エピハロヒドリンが２．５当量よりも少ない場合、エポキシ基と未反応水酸基が反応しやすくなるため、エポキシ基と未反応水酸基が付加反応して生成する基（-CH₂CR(OH)CH₂-、R：水素原子又は有機炭素基）を含んだ高分子量物が得られる。一方、２．５当量よりも多い場合、理論構造物の含有量が高くなる。所望の特性によってエピハロヒドリンの量を適宜調節すればよい。
【００３３】
本発明に用いるエポキシ樹脂を得る反応において、アルカリ金属水酸化物はその水溶液を使用してもよく、その場合は該アルカリ金属水酸化物の水溶液を連続的に反応系内に添加すると共に減圧下、または常圧下連続的に水及びエピハロヒドリンを留出させ、更に分液し水は除去しエピハロヒドリンは反応系内に連続的に戻す方法でもよい。
【００３４】
また、芳香族性水酸基含有化合物と芳香族骨格含有カルボニル化合物との縮合物類、例えば上記一般式（４）で表わされる芳香族ジオール化合物で表されるビスフェノール化合物とエピハロヒドリンの溶解混合物にテトラメチルアンモニウムクロライド、テトラメチルアンモニウムブロマイド、トリメチルベンジルアンモニウムクロライド等の４級アンモニウム塩を触媒として添加し５０〜１５０℃で１〜５時間反応させて得られる一般式（１）、または上記一般式（２）の化合物のハロヒドリンエーテル化物にアルカリ金属水酸化物の固体または水溶液を加え、再び２０〜１２０℃で１〜１０時間反応させ脱ハロゲン化水素（閉環）させる方法でもよい。
【００３５】
更に、反応を円滑に進行させるためにメタノール、エタノール、イソプロピルアルコール、ブタノールなどのアルコール類、アセトン、メチルエチルケトンなどのケトン類、ジオキサンなどのエーテル類、ジメチルスルホン、ジメチルスルホキシド等の非プロトン性極性溶媒などを添加して反応を行うことが好ましい。
溶媒を使用する場合のその使用量は、エピハロヒドリンの量に対し通常５〜５０重量％、好ましくは１０〜３０重量％である。また非プロトン性極性溶媒を用いる場合はエピハロヒドリンの量に対し通常５〜１００重量％、好ましくは１０〜６０重量％である。
【００３６】
これらのエポキシ化反応の反応物を水洗後、または水洗無しに加熱減圧下、１１０〜２５０℃、圧力１０ｍｍＨｇ以下でエピハロヒドリンや他の添加溶媒などを除去する。また更に加水分解性ハロゲンの少ないエポキシ樹脂とするために、エピハロヒドリン等を回収した後に得られる粗エポキシ樹脂を再びトルエン、メチルイソブチルケトンなどの溶剤に溶解し、水酸化ナトリウム、水酸化カリウムなどのアルカリ金属水酸化物の水溶液を加えて更に反応させて閉環を確実なものにすることもできる。この場合、アルカリ金属水酸化物の使用量は粗エポキシ樹脂中に残存する加水分解性塩素１モルに対して、通常０．５〜１０モル、好ましくは１．２〜５．０モルである。反応温度は通常５０〜１２０℃、反応時間は通常０．５〜３時間である。反応速度の向上を目的として、４級アンモニウム塩やクラウンエーテル等の相関移動触媒を存在させてもよい。相関移動触媒を使用する場合のその使用量は、粗エポキシ樹脂に対して０．１〜３．０重量％の範囲が好ましい。
【００３７】
反応終了後、生成した塩を濾過、水洗などにより除去し、更に、加熱減圧下トルエン、メチルイソブチルケトンなどの溶剤を留去することにより本発明のエポキシ樹脂が得られる。
【００３８】
次いで、本発明のエポキシ樹脂組成物について説明する。本発明のエポキシ樹脂組成物は、前記の一般式（１）、一般式（２）で表わされるエポキシ樹脂、或いは、一般式（３）、一般式（４）、或いは、構造式（９）〜（１１）で表わされる縮合物とエピハロヒドリンとを反応させて得られるエポキシ樹脂と硬化剤を必須成分として含有する。
【００３９】
また、本発明のエポキシ樹脂成形材料には他のエポキシ樹脂を併用して使用することが出来る。併用する場合、前述のエポキシ樹脂の全エポキシ樹脂中に占める割合は３０重量％以上が好ましく、特に４０重量％以上が好ましい。本発明のエポキシ樹脂と併用し得る他のエポキシ樹脂としては、公知公用の全てのエポキシ樹脂を用いることができるが、例示するならばビスフェノールＡ型エポキシ樹脂、ビスフェノールＦ型エポキシ樹脂、ビフェニル型エポキシ樹脂、テトラメチルビフェニル型エポキシ樹脂、フェノールノボラック型エポキシ樹脂、クレゾールノボラック型エポキシ樹脂、トリフェニルメタン型エポキシ樹脂、テトラフェニルエタン型エポキシ樹脂、ジシクロペンタジエン−フェノール付加反応型エポキシ樹脂、フェノールアラルキル型エポキシ樹脂、ナフトールノボラック型エポキシ樹脂、ナフトールアラルキル型エポキシ樹脂、ナフトール−フェノール共縮ノボラック型エポキシ樹脂、ナフトール−クレゾール共縮ノボラック型エポキシ樹脂、芳香族炭化水素ホルムアルデヒド樹脂変性フェノール樹脂型エポキシ樹脂、ビフェニル変性ノボラック型エポキシ樹脂、テトラブロモビスフェノールＡ型エポキシ樹脂、ブロム化フェノールノボラック型エポキシ樹脂などが挙げられるがこれらに限定されるものではない。これらエポキシ樹脂は単独で用いてもよく、２種以上混合して使用してもよい。
【００４０】
また、下記の一般式（５）で表される多価芳香族性水酸基含有化合物類
【化１４】

（式中、Ｒ _１ 〜Ｒ₃は、互いに同一でも異なっていてもよい水素原子、メチル基、フェニルエチリデン基、またはフェニル基を表わし、ｎは１を超える繰り返し単位数を表す。）で表される多価芳香族性水酸基含有化合物とエピハロヒドリンとの反応によって得られるエポキシ樹脂も使用できるエポキシ樹脂類に含まれる。
【００４１】
本発明に用いられる硬化剤としては、例えばアミン系化合物、酸無水物系化合物、アミド系化合物、フェノ−ル系化合物などの公知公用の硬化剤が全て用いることができる。例示するならば、ジアミノジフェニルメタン、ジエチレントリアミン、トリエチレンテトラミン、ジアミノジフェニルスルホン、イソホロンジアミン、ジシアンジアミド、リノレン酸の２量体とエチレンジアミンとより合成されるポリアミド樹脂、無水フタル酸、無水トリメリット酸、無水ピロメリット酸、無水マレイン酸、テトラヒドロ無水フタル酸、メチルテトラヒドロ無水フタル酸、無水メチルナジック酸、ヘキサヒドロ無水フタル酸、メチルヘキサヒドロ無水フタル酸、フェノールノボラック樹脂、クレゾールノボラック樹脂、芳香族炭化水素ホルムアルデヒド樹脂変性フェノール樹脂、ジシクロペンタジエンフェノール付加型樹脂、フェノールアラルキル樹脂、ナフトールアラルキル樹脂、トリメチロールメタン樹脂、テトラフェニロールエタン樹脂、ナフトールノボラック樹脂、ナフトール−フェノール共縮ノボラック樹脂、ナフトール−クレゾール共縮ノボラック樹脂、ビフェニル変性フェノール樹脂、アミノトリアジン変性フェノール樹脂等を始めとする多価フェノール化合物、及びこれらの変性物、イミダゾ−ル、ＢＦ₃ −アミン錯体、グアニジン誘導体などが挙げられるがこれらに限定されるものではない。これらは単独で用いてもよく、２種以上併用してもよい。これらのなかでも、フェノールノボラック樹脂、クレゾールノボラック樹脂、芳香族炭化水素ホルムアルデヒド樹脂変性フェノール樹脂、フェノールアラルキル樹脂、ナフトールアラルキル樹脂、ナフトールノボラック樹脂、ナフトール−フェノール共縮ノボラック樹脂、ナフトール−クレゾール共縮ノボラック樹脂、ビフェニル変性フェノール樹脂、アミノトリアジン変性フェノール樹脂が難燃性に優れることから好ましく、そのなかでも芳香族炭化水素ホルムアルデヒド樹脂変性フェノール樹脂、フェノールアラルキル樹脂、ナフトールアラルキル樹脂、ビフェニル変性フェノール樹脂、アミノトリアジン変性フェノール樹脂などの水酸基非含有芳香族骨格含有基を結節基として、水酸基含有芳香族核が連結された構造を有する多価芳香族性水酸基含有化合物が特に難燃性に優れることから好ましい。
【００４２】
また、上記の多価芳香族性水酸基含有化合物としては、前記一般式（３）、（４）、及び（９）〜（１２）で表わされる化合物も含まれる。
【００４３】
また、更に、上記の一般式（５）で表される多価芳香族性水酸基含有化合物も含まれる。
【００４４】
本発明で用いられる硬化剤の使用量は、硬化反応が完結し、良好な硬化物性が得られる点から、エポキシ樹脂のエポキシ基１当量に対して、硬化剤中の活性水素基が０．７〜１．５当量になる量が好ましい。
【００４５】
また、本発明のエポキシ樹脂組成物には、硬化促進剤を適宜使用することもできる。硬化促進剤としては公知慣用のものがいずれも使用できるが、例えば、リン系化合物、第３級アミン、イミダゾール、有機酸金属塩、ルイス酸、アミン錯塩、等が挙げられ、これらは単独のみならず２種以上の併用も可能である．半導体封止材料用途としては、リン系ではトリフェニルホスフィン、アミン系では１，８−ビシクロ−[５，４，０]−ウンデセン（ＤＢＵ）などが、硬化性、耐熱性、電気特性、耐湿信頼性などが優れるために好ましいものである。
【００４６】
また、本発明のエポキシ樹脂組成物には、無機質充填材を適宜使用することもできる。本発明で用いられる無機質充填材としては、例えば、溶融シリカ、結晶シリカ、アルミナ、窒化珪素、窒化アルミ等が挙げられる。無機質充填材の配合量を特に大きくする場合は、溶融シリカを用いるのが一般的である。溶融シリカは、破砕状、球状のいずれでも使用可能であるが、溶融シリカの配合量を高め、且つ成形材料の溶融粘度の上昇を抑えるためには、球状のものを主に用いる方が好ましい。更に球状シリカの配合量を高めるためには、球状シリカの粒度分布がより広くなるように調整することが好ましい。その充填率は難燃性を鑑みれば高い方が好ましく、エポキシ樹脂組成物の全体量に対して６５重量％以上が特に好ましく、更に８５重量％以上が好ましい。
【００４７】
また、本発明のエポキシ樹脂組成物には、難燃剤、または難燃付与剤を適宜使用することもできる。本発明で用いられる難燃剤、または難燃付与剤としては、公知のものが全て使用できるが、例えば、燐原子含有化合物や窒素原子含有化合物、有機ケイ素化合物や無機系難燃化合物などが挙げられる。
【００４８】
それらの具体例を挙げるならば、燐原子含有化合物としては、赤燐、ポリ燐酸アンモニウム及び燐酸エステル化合物、ホスフィン酸、ホスファゼン化合物などの有機燐化合物が挙げられる。ここでいう赤燐とは、表面処理が施されていてもよく、例えば、水酸化マグネシウム、水酸化亜鉛、水酸化チタン等の金属水酸化物の被膜で被覆処理されたもの、水酸化マグネシウム、水酸化亜鉛、水酸化チタン等および熱硬化性樹脂よりなる被膜で被覆処理されたもの、水酸化マグネシウム、水酸化亜鉛、水酸化チタン等より選ばれる金属水酸化物の被膜の上に熱硬化性樹脂の被膜で二重に被覆処理されたもの等がいずれも使用可能である。また上記燐化合物としては、燐酸アミド等、アミノ基、フェノール性水酸基、エポキシ基等の官能基を有していてもよい。これらの燐化合物の添加量は、前記に例示される充填材を除く他の全配合成分に対して、難燃性の向上効果が顕著となる点から０．１重量％以上が好ましく、成形性、耐湿性の低下の影響や燐原子含有化合物のブリードがない少なく燐原子の量で、難燃性の向上効果が顕著である点から０．１重量％以上が好ましく、成形性、耐湿性が良好で、燐原子含有化合物のブリードがない点から５．０重量％以下が好ましい。更に、より好ましくは０．２〜３．０重量％の範囲である。
【００４９】
窒素原子含有化合物としては、メラミン、ベンゾグアナミン、アセトグアナミンおよび上記したトリアジン化合物から誘導される化合物、硫酸メラミン、硫酸アミノトリアジン、メラミンシアヌレート、シアヌル酸等が挙げられ、これらはフェノール性水酸基等の官能基を有していてもよい。これらの窒素原子含有化合物の添加量は、前記に例示される充填材を除く他の全配合成分に対して、窒素原子の量で、難燃性の向上効果が顕著となる点から０．１重量％以上が好ましく、耐湿性が良好である点から２０重量％以下が好ましく、更に、より好ましくは１〜１０重量％の範囲である。
【００５０】
有機ケイ素化合物としては、フェニル基やメチル基等のアルキル基を含有する化合物が挙げられ、これらはフェノール性水酸基、アミノ基、エポキシ基等の官能基を有していてもよい。これらの有機ケイ素化合物の添加量は、前記に例示される充填材を除く他の全配合成分に対して、窒素原子の量で難燃性の向上効果が顕著であることから０．１以上が好ましく、密着性が良好な点から２０重量％以下が好ましい。更に、好ましくは１〜１０重量％の範囲である。
【００５１】
無機系難燃化合物としては、水酸化アルミニウム、水酸化マグネシウム、ドロマイト、ハイドロタルサイト、水酸化カルシウム、水酸化バリウム、塩基性炭酸マグネシウム、水酸化ジルコニウム、酸化スズの水和物等の水和金属系化合物、シリカ、酸化アルミニウム、酸化鉄、酸化チタン、酸化マンガン、酸化マグネシウム、酸化ジルコニウム、酸化亜鉛、酸化モリブデン、酸化コバルト、酸化ビスマス、酸化クロム、酸化スズ、酸化アンチモン、酸化ニッケル、酸化銅、酸化タングステン等の金属酸化物、アルミニウム、鉄、フェロセン、チタン、マンガン、亜鉛、モリブデン等の金属類表面を樹脂や無機物で表面被覆したもの、コバルト、コバルトナフテン酸錯体、コバルトエチレンジアミン錯体等のコバルト金属錯体、ホウ酸、ホウ砂、ホウ酸亜鉛等のホウ酸金属塩、炭酸亜鉛、炭酸マグネシウム、炭酸カルシウム、炭酸バリウム等が挙げられる。上記無機系難燃化合物は、表面を樹脂や無機物で表面被覆したものが使用可能であり、表面被覆により密着性向上など封止材とした場合の信頼性が向上する。これらの無機系難燃化合物の添加量は、前記に例示される充填材を除く他の全配合成分に対して、難燃性の向上効果が顕著となる点から０．１重量％以上が好ましく、成形性が良好な点から１０重量％以下が好ましい。また、より好ましくは０．１〜５重量％の範囲である。
【００５２】
また、本発明のエポキシ樹脂組成物には、必要に応じて、シランカップリング剤、離型剤、顔料等の種々の配合剤を添加することができる。
【００５３】
前記のように配合したエポキシ樹脂組成物は、エポキシ樹脂成形材料として用いることができる。前記エポキシ樹脂成形材料は、各成分を均一に混合することにより得られる。本発明のエポキシ樹脂、硬化剤、更に必要により硬化促進剤の配合された本発明のエポキシ樹脂組成物は従来知られている方法と同様の方法で容易に硬化物とすることができる。
【００５４】
例えば、エポキシ樹脂成形材料として半導体封止材料用に調製するためには、エポキシ樹脂と硬化剤、充填剤等の配合剤とを必要に応じて押出機、ニ−ダ、ロ−ル等を用いて均一になるまで充分に混合して溶融混合型のエポキシ樹脂組成物を得ればよい。その際、充填剤としては、通常シリカが用いられるが、その充填率は、エポキシ樹脂組成物全量当たり３０〜９５重量％の範囲が用いられ、難燃性や耐湿性や耐ハンダクラック性の向上、線膨張係数の低下を図るためには、好ましくは６５重量％以上、それら効果を格段に上げるためには８０重量％以上が特に好ましい。
【００５５】
また、エポキシ樹脂成形材料として回路基板材料用に調製するためには、本発明のエポキシ樹脂組成物をトルエン、キシレン、アセトン、メチルエチルケトン、メチルイソブチルケトン等の溶剤に溶解させてワニス状組成物として用いることができる。この際の溶剤は、本発明のエポキシ樹脂組成物と該溶剤の混合物中で通常１０〜７０重量％、好ましくは１５〜６５重量％、特に好ましくは２０〜５０重量％を占める量を用いる。なお、前記回路基板材料としては、例えば、プリント配線基板、プリント回路板、フレキシブルプリント配線板、ビルドアップ配線板等が挙げられる。
【００５６】
本発明の硬化物は、本発明のエポキシ樹脂組成物を熱硬化させて得ることができ、成型物、積層物、注型物、接着剤、塗膜、フィルムなどの形態をもつ。例えば、溶融混合型の組成物の場合は、該組成物を注型あるいはトランスファ−成形機、射出成形機などを用い８０〜２００℃で２〜１０時間に加熱することにより硬化物を得ることができ、半導体パッケージ成形はこれに該当する。また、ワニス状組成物の場合は、それをガラス繊維、カーボン繊維、ポリエステル繊維、ポリアミド繊維、アルミナ繊維、紙などの基材に含浸させ加熱乾燥してプリプレグを得、それを熱プレス成形して硬化物を得ることができ、プリント配線板材料用の積層材料はこれに該当する。
【００５７】
上記のエポキシ樹脂組成物は、実質的にハロゲン化合物を含有しない難燃性エポキシ樹脂として使用できる。本発明の実質的にハロゲン化合物を含有しない難燃性エポキシ樹脂とは、難燃性の目的をもって添加されるハロゲン化合物を含まなくとも、難燃性を示すエポキシ樹脂組成物を意味する。したがって、エピハロヒドリン類から誘導されるエポキシ樹脂に含まれる５０００ppm以下程度の微量不純物ハロゲンはこの意味とは異なるので、仮に含まれていてもかまわない。
【００５８】
【実施例】
次に本発明を実施例、比較例により具体的に説明するが、以下において部及び％は特に断わりのない限り重量部である。
【００５９】
実施例１
温度計、滴下ロート、冷却管、撹拌機を取り付けたフラスコに窒素ガスパージを施しながら、２、６−キシレノール３６６ｇ（３．０モル）と４−ビフェニルアルデヒド２７３ｇ（１．５モル）とトルエン５００ｇを入れて溶解した。次いでパラトルエンスルホン酸１３．７ｇを加えて、環留温度まで昇温してホールドした。留出したトルエンと水分をディーントラップ中で分離して、トルエンのみを系内に戻した。そのまま５時間撹拌を続けた後に、室温まで冷却すると結晶が析出した。その結晶を濾別して、トルエンとメタノールで洗浄したのちに、乾燥して目的のビスフェノール化合物５０５ｇを得た。得られた結晶の純度はGPC分析で９９％であり、NMRスペクトル（C¹³、溶媒DMSO、図１）とIRスペクトル（KBr法、図２）とマススペクトル（FD-MS、図３）から、前記構造式（９）で表されるビスフェノール化合物であることが確認された。
【００６０】
次いで得られたビスフェノール化合物２０４ｇ（水酸基１．０当量）、エピクロルヒドリン４６３ｇ（５．０モル）、ｎ−ブタノール５３ｇ、テトラエチルベンジルアンモニウムクロライド２．３ｇを仕込み溶解させた。６５℃に昇温した後に、共沸する圧力までに減圧して、４９％水酸化ナトリウム水溶液８２ｇ（１．０モル）を５時間かけて滴下した、次いで同条件下で０．５時間撹拌を続けた。この間、共沸で留出してきた留出分をディーンスタークトラップで分離して、水層を除去し、油層を反応系内に戻しながら反応した。その後、未反応のエピクロルヒドリンを減圧蒸留して留去させた。それで得られた粗エポキシ樹脂にメチルイソブチルケトン５５０ｇとｎ−ブタノール５５ｇとを加え溶解した。更にこの溶液に１０％水酸化ナトリウム水溶液１５ｇを添加して８０℃で２時間反応させた後に洗浄液のＰＨが中性となるまで水１００ｇで水洗を３回繰り返した。次いで共沸によって系内を脱水し、精密濾過を経た後に、溶媒を減圧下で留去して前記構造式（３）で表わされるエポキシ樹脂（Ａ）２３８ｇを得た。得られたエポキシ樹脂のエポキシ当量は２８５g/eq．、軟化点８４℃、150℃での溶融粘度（ICI粘度計）は２．３psであった。このエポキシ樹脂はとNMRスペクトル（C¹³、溶媒DMSO、図４）とIRスペクトル（図５）とマススペクトル（FD-MS、図６）とGPC（東ソー製 HLC-802A、カラム：TSK gel G4、３、２、２HXL、検出器RI、溶媒THF、図７）から前記構造式（３）で表される化学構造を有していることが確認された。（ｒは平均値で０．１）
【００６１】
合成例１
温度計、滴下ロート、冷却管、撹拌機を取り付けたフラスコに窒素ガスパージを施しながら、下記構造式（４０）で表わされるで表されるビスフェノール化合物１７６ｇ（水酸基１．０当量）、エピクロルヒドリン３７０部（４．０モル）、ｎ−ブタノール４２ｇ、テトラエチルベンジルアンモニウムクロライド２．３ｇを仕込み溶解させた。６５℃に昇温した後に、共沸する圧力までに減圧して、４９％水酸化ナトリウム水溶液８２ｇ（１．０モル）を５時間かけて滴下した、次いで同条件下で０．５時間撹拌を続けた。この間、共沸で留出してきた留出分をディーンスタークトラップで分離して、水層を除去し、油層を反応系内に戻しながら反応した。その後、未反応のエピクロルヒドリンを減圧蒸留して留去させた。それで得られた粗エポキシ樹脂にメチルイソブチルケトン４９０ｇとｎ−ブタノール４９ｇとを加え溶解した。更にこの溶液に１０％水酸化ナトリウム水溶液１５ｇを添加して８０℃で２時間反応させた後に洗浄液のＰＨが中性となるまで水１００ｇで水洗を３回繰り返した。次いで共沸によって系内を脱水し、精密濾過を経た後に、溶媒を減圧下で留去して下記構造式（４１）で表わされるエポキシ樹脂（Ｂ）２１２ｇを得た。得られたエポキシ樹脂のエポキシ当量は２４７g/eq．、軟化点５６℃、１５０℃での溶融粘度（ICI粘度計）は０．３psであった。
【化２２】

実施例２〜３と比較例１〜６
実施例１で得られたエポキシ樹脂（Ａ）と比較として、合成例１で合成したエポキシ樹脂（Ｂ）、ビスフェノールＡ型エポキシ樹脂（EPICLON １０５５：大日本インキ化学工業（株）製、エポキシ当量４７５g/eq．）、クレゾールノボラック型エポキシ樹脂（EPICLON N-665-EXP-S：大日本インキ化学工業製、エポキシ当量２０２g/eq．）を用いて、硬化剤としてフェノールノボラック樹脂（PHENOLITE TD-2131：大日本インキ化学工業製、軟化点８０℃、水酸基当量１０４g/eq．）、フェノールアラルキル樹脂（ミレックス XL-225-2L：三井化学（株）製、軟化点７４℃、水酸基当量１７５g/eq．）、硬化促進剤としてトリフェニルホスフィン（ＴＰＰ）、無機充填材として溶融シリカ（龍森（株）製、RD-8）を用いて、表１に示した組成で配合し、２本ロールを用いて１００℃の温度で１０分間溶融混練して目的の組成物を得た。これを１８０℃で１０分間プレス成形し、その後１８０℃で５時間さらに硬化せしめた後に、難燃性試験を行った。試験はＵＬ−９４Ｖ試験に準拠して行い、評価は試験片５本の合計燃焼時間で比較した。
尚、試験片は厚さ１／１６インチのものを用いた。
難燃性試験結果を第１表に示す。
【００６２】
【表１】

【００６３】
【発明の効果】
本発明のエポキシ樹脂は難燃性に優れ、ハロゲン化合物を含有しなくても優れた難燃性をその硬化物に付与できる。環境問題に対応した半導体封止材料やプリント配線基板などの電子材料分野のエポキシ樹脂材料としてきわめて有用である。
【図面の簡単な説明】
【図１】 実施例１で得られた本発明に係る芳香族性水酸基含有化合物とビフェニル骨格含有カルボニル化合物との縮合物の¹³Ｃ核磁気共鳴吸収スペクトルである。
【図２】 実施例１で得られた本発明に係る芳香族性水酸基含有化合物とビフェニル骨格含有カルボニル化合物との縮合物の赤外吸収スペクトルである。
【図３】 実施例１で得られた本発明に係る芳香族性水酸基含有化合物とビフェニル骨格含有カルボニル化合物との縮合物のマススペクトルある。
【図４】 実施例１で得られた本発明に係るエポキシ樹脂の縮合物の¹³Ｃ核磁気共鳴吸収スペクトルである。
【図５】 実施例１で得られた本発明に係るエポキシ樹脂の赤外吸収スペクトルである。
【図６】 実施例１で得られた本発明に係るエポキシ樹脂のマススペクトルある。
【図７】 実施例１で得られた本発明に係るエポキシ樹脂のＧＰＣチャートである。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin composition that contains a halogen-free epoxy resin containing a skeleton excellent in flame retardancy, a halogen-free cured flame retardant used for semiconductor sealing materials and printed wiring board materials, etc. And a composition for semiconductor sealing material and printed wiring board material containing the epoxy resin.
[0002]
[Prior art]
Epoxy resins are generally cured with various curing agents, resulting in cured products with excellent mechanical properties, moisture resistance, chemical resistance, heat resistance, electrical properties, etc., adhesives, paints, laminates, molding It is used in a wide range of fields such as materials and casting materials. Conventionally, the most industrially used epoxy resins are liquid and solid bisphenol A type epoxy resins obtained by reacting bisphenol A with epichlorohydrin, and novolaks obtained by reacting phenols with an aldehyde component. There are novolak-type epoxy resins obtained by reacting a resin with epichlorohydrin.
In the field of electronic materials such as semiconductor encapsulants and printed wiring boards, high flame retardancy (UL-94V-0) is required. For semiconductor encapsulant applications, cresol novolac-type epoxy resins and phenol novolac resins have tetra Compositions in which halogen compounds such as bromobisphenol A type epoxy resin are combined are widely used. On the other hand, in printed wiring board applications, an epoxy resin obtained by reacting bisphenol A type epoxy resin with tetrabisphenol A is used as a main raw material component, and an epoxy resin in which various epoxy resins are mixed and a curing agent are used. Yes.
[0003]
[Problems to be solved by the invention]
As described above, a material using a bisphenol A type epoxy resin or a novolac type epoxy resin is flame retardant, and therefore a halogen compound is essential.
However, in recent years, halogen-based flame retardants as a factor for generating dioxins have been regarded as a problem from the viewpoint of environmental protection, and a flame-retardant epoxy resin material containing no halogen compound is strongly demanded.
[0004]
On the other hand, in semiconductor encapsulating material applications, as the surface mounting method of semiconductors has become widespread, solder crack resistance of semiconductor packages has become an important issue, and the cresol novolac type epoxy resin and phenol novolac resin are combined. Although the semiconductor sealing material has excellent heat resistance, it has a problem that solder crack resistance deteriorates due to poor moisture resistance. As a means for solving such a problem, for example, in Japanese Patent Application Laid-Open No. 2000-1524, moisture resistance is improved by using an epoxy resin derived from bis (hydroxyphenyl) methyl-1,1′-biphenyl. Technology is disclosed. However, the invention of Japanese Patent Laid-Open No. 2000-1524 only describes an epoxy resin having a structure that does not contain a substituent in the aromatic ring, and although a cured product having a low viscosity and excellent moisture resistance can be obtained, it is inferior in flame retardancy. Therefore, in order to obtain the flame retardancy required in the field of electronic materials, the combined use of halogen-based epoxy resins is inevitable, and there is a problem that it cannot be put into practical use as a halogen-free prescription.
[0005]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a flame-retardant epoxy resin material characterized by substantially not containing a halogen compound.
[0006]
[Means for Solving the Problems]
In light of these circumstances, the present inventors have intensively searched for an epoxy resin that gives a cured product that is halogen-free and excellent in flame retardancy. As a result, the epoxy resin having a specific structure having a substituent in the condensed ring or aromatic ring, particularly the same An epoxy resin having a 2,6-xylenol structure and a biphenyl structure in the molecular structure is a novel compound, and the structure has been found to dramatically improve flame retardancy and satisfy the above requirements. It came to complete.
[0007]
That is, the present invention relates to the general formula (1)
[Chemical 6]

( Wherein R _{1 to} R ₃ are the same as or different from each other, a hydrogen atom, a methyl group,
Phenyl ethylidene group or a phenyl group, and at least one of the methyl groups of R ₁ to R _3, a phenyl group, a phenyl ethylidene group, R ₇ represents a hydrogen atom or a methyl group, q is an average value of 0 Represents a value from 10 to 10. The epoxy resin represented by this is provided.
[0008]
In addition, the present invention provides a general formula (3)
[Chemical 7]

( Wherein R _{1 to} R ₃ are the same as or different from each other, a hydrogen atom, a methyl group,
Phenyl ethylidene group or a phenyl group, and at least one of the methyl groups of R ₁ to R _3, a phenyl group, a phenyl ethylidene group. An epoxy resin obtained by reacting an aromatic diol compound represented by (II) with an epihalohydrin is also provided.
[0009]
Further, the present invention is characterized in that an epoxy resin composition comprising the above epoxy resin and a curing agent as essential components, the above epoxy resin and a curing agent as essential components, and substantially free of a halogen compound. A flame retardant epoxy resin composition, or a cured product obtained by curing the epoxy resin composition, and the following general formula (3)
[Chemical 8]

(Wherein R _{1 to} R ₃ are the same as or different from each other, a hydrogen atom, a methyl group,
It represents a phenylethylidene group or a phenyl group, and at least one of R _{1 to} R ₃ represents a methyl group, a phenyl group or a phenylethylidene group, and R ₇ represents a hydrogen atom or a methyl group. The aromatic diol compound represented by this is also provided.
[0010]
Examples of the epoxy resin used in the present invention include the following structural formula ( 5 )
[Chemical 9]

In through the knot group represented, at least one methyl group, a phenyl group or a phenyl glycidyl ether residue substituted with phenyl ethylidene group is bound compound.
[0011]
The epoxy resin represented by the general formula (1) of the present invention, for example, epoxy resins represented by structural formula (2).
[0012]
[Chemical Formula 10]

[0013]
The epoxy resin is obtained by condensation of an aromatic skeleton-containing carbonyl compounds such as aromatic hydroxyl group-containing compound and an aromatic skeleton-containing ketones or aromatic skeleton-containing aldehydes, and epihalohydrin are reacted For example .
[0016]
In addition, the epoxy resin of the present invention has low heat resistance and low viscosity, can increase the filling rate of the inorganic filler, and is excellent in performance as a semiconductor sealing material such as moisture resistance and flame retardancy. The ICI viscosity is preferably 5 dPa · s or less, and more preferably 3 dPa · s or less.
[0017]
A method for producing a condensate of an aromatic hydroxyl group-containing compound and an aromatic skeleton-containing carbonyl compound used in the present invention will be described. The condensate can be obtained by subjecting an aromatic skeleton-containing carbonyl compound such as phenols and biphenylaldehydes to a condensation reaction.
[0018]
Subsequently, a condensate of an aromatic hydroxyl group-containing compound represented by the general formula (4) with an aromatic skeleton-containing carbonyl compound such as an aromatic skeleton-containing ketone or an aromatic skeleton-containing aldehyde is reacted with an epihalohydrin. The obtained epoxy resin will be described.
[0019]
As a condensate (hereinafter referred to as a condensate) of the aromatic hydroxyl group-containing compound and the aromatic skeleton-containing carbonyl compound, the following structural formula ( 5 )
Embedded image

The structure is not particularly limited as long as it is a phenol compound having a structure in which two are bonded via a nodule group represented by the following formula.
[0020]
As said condensate, the aromatic diol compound of this invention represented, for example by the following general formula ( 3 ) is mentioned.
Embedded image

( Wherein R _{1 to} R ₃ are the same as or different from each other, a hydrogen atom, a methyl group,
Phenyl ethylidene group or a phenyl group, and, Wath at least one methyl group R ₁ to R _3, a phenyl group, a phenyl ethylidene group table. )
[0023]
Aromatic hydroxyl group-containing compounds, as used herein, is not limited in particular as long as the aromatic compound having one aromatic hydroxyl groups in the molecule, if illustrated cresol, dimethylphenol ( Xylenol), trimethylphenol , phenylphenol and the like. Among these, the use of a phenol compound that exhibits monofunctionality with respect to condensation reactivity with aldehyde functional groups represented by 2,6-xylenol, 2,4-xylenol, etc. It is preferable because the rate is easily increased.
When a phenol compound showing polyfunctionality with respect to condensation reactivity with aldehyde functional groups represented by phenol, etc. is used, it becomes novolak, and in order to extract only two functional components, it is necessary to repeat purification such as recrystallization and yield. Is significantly reduced. From the viewpoint of flame retardancy, compounds containing a methyl group or a condensed ring are preferred, and among them, 2,6-xylenol and 2,4-xylenol are particularly preferred because the flame retardancy is remarkably improved. Two or more of these may be used in combination.
[0024]
Thus, when considered in conjunction with simplicity of manufacture and flame retardancy, the aromatic hydroxyl-containing compound is preferable to use 2,6-xylenol and 2,4-xylenol, and among them, 2,6-xylenol are particularly preferable.
[0025]
In addition, examples of the aromatic skeleton-containing carbonyl compound include aromatic skeleton-containing ketones and aromatic skeleton-containing aldehydes. Among these, aromatic skeleton-containing aldehydes are preferable from the viewpoint of excellent reactivity with phenols. Compounds containing these aromatic aldehyde group By way of example, 4-biphenyl aldehyde and the like.
[0026]
Among the condensation products of aromatic hydroxyl group-containing compound and a biphenyl skeleton-containing aldehyde compound represented by the above general formula (1), for example, phenols represented by the following structural formula (9) to (12), obtained Preferred as an epoxy resin.
Embedded image

[0027]
Among these aromatic diol compounds, since the flame retardancy is dramatically improved, the aromatic diol compound of the structural formula (9) having a 2,6-xylenol structure and a biphenyl structure in the molecule is particularly preferable.
[0028]
Epoxy resins obtained from these aromatic diol compounds and epihalohydrins have low heat resistance and low viscosity, can increase the filling rate of inorganic fillers, and are excellent in performance as semiconductor sealing materials such as moisture resistance and flame resistance. Therefore, the ICI viscosity at 150 ° C. is preferably 5 dPa · s or less, and more preferably 3 dPa · s or less.
[0029]
Subsequently, the manufacturing method of the condensate of the aromatic hydroxyl group containing compound and aromatic skeleton containing carbonyl compound used for this invention is demonstrated. The condensate can be obtained by subjecting an aromatic skeleton-containing carbonyl compound such as phenols and biphenylaldehydes to a condensation reaction.
[0030]
This condensation reaction is usually carried out in the presence of an acid catalyst by adding phenols and biphenylaldehydes in the former / the latter = 2/1 to 30/1 (molar ratio). Moreover, you may use an organic solvent as needed. As for the charging ratio, when phenols having a bifunctional or higher property with respect to the condensation reaction with the carbonyl compounds such as phenol and cresol are used, the phenols / the carbonyl compounds (molar ratio) should be four times or more. It is preferable to increase the yield of the desired bisphenol compound. In the case of using monofunctional phenols for the condensation reaction with carbonyl compounds such as 2,6-xylenol and 2,6-xylenol, phenols / carbonyl compounds = 2-4 (molar ratio). ) But the desired bisphenol compound can be obtained in high yield. The acid catalyst is not particularly limited as long as it is a catalyst usually used in the condensation reaction of phenols and the carbonyl compounds. For example, hydrochloric acid, sulfuric acid, sulfuric anhydride, p-toluene Examples include sulfonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, oxalic acid, formic acid, phosphoric acid, trichloroacetic acid, and trifluoroacetic acid. The added amount of the catalyst is 0.01 to 5% by weight based on the total weight of the phenols and aldehydes. The organic solvent includes aromatic organic solvents such as benzene, toluene and xylene, ketone organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and alcohols such as methanol, ethanol, isopropyl alcohol and normal butanol. An organic solvent or the like can be used, and may be appropriately selected in consideration of properties such as the raw materials used and the solubility of the product, reaction conditions, economy, and the like. The amount of the organic solvent is 10 to 500% by weight based on the synthetic weight of phenols and aldehydes. The reaction conditions are usually from room temperature to 200 ° C., preferably from 50 to 150 ° C., with stirring for about 0.5 to 30 hours. When the reaction product easily crystallizes after completion of the reaction, the reaction solution may be cooled and the target product may be isolated by crystallization. At that time, operations such as concentration, neutralization, washing, and recrystallization may be performed as necessary. If the reaction product is difficult to crystallize, the concentrate may be purified by recrystallization or reprecipitation to increase the purity of the target product.
[0031]
Next, a method for obtaining the epoxy resin of the present invention from a condensate of an aromatic hydroxyl group-containing compound and an aromatic skeleton-containing carbonyl compound, for example, an aromatic diol compound represented by the general formula (4) will be described. As a method for obtaining the epoxy resin of the present invention, a method known per se can be adopted. For example, the bisphenol compound represented by the general formula (4) obtained above and epichlorohydrin, epibromohydrin, methyl epichlorohydrin, etc. The epoxy resin of the present invention can be obtained by adding an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide to a dissolved mixture of epihalohydrin or reacting at 20 to 120 ° C. for 1 to 10 hours while adding. .
[0032]
The addition amount of epihalohydrin is usually in the range of 0.3 to 20 equivalents per 1 equivalent of hydroxyl group in the starting aromatic diol compound. When the epihalohydrin is less than 2.5 equivalents, the epoxy group and the unreacted hydroxyl group are likely to react with each other. Therefore, a group formed by the addition reaction of the epoxy group and the unreacted hydroxyl group (—CH ₂ CR (OH) CH ₂ —, A high molecular weight product containing R: a hydrogen atom or an organic carbon group is obtained. On the other hand, when it is more than 2.5 equivalents, the content of the theoretical structure becomes high. The amount of epihalohydrin may be appropriately adjusted according to desired characteristics.
[0033]
In the reaction for obtaining the epoxy resin used in the present invention, an aqueous solution of the alkali metal hydroxide may be used. In that case, the aqueous solution of the alkali metal hydroxide is continuously added to the reaction system and the pressure is reduced. Alternatively, water and epihalohydrin may be distilled off continuously under normal pressure, followed by liquid separation to remove water and epihalohydrin to be continuously returned to the reaction system.
[0034]
Further, a condensate of an aromatic hydroxyl group-containing compound and an aromatic skeleton-containing carbonyl compound, for example, tetramethylammonium in a dissolved mixture of a bisphenol compound and an epihalohydrin represented by the aromatic diol compound represented by the above general formula (4) General formula (1) obtained by adding a quaternary ammonium salt such as chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride or the like as a catalyst and reacting at 50 to 150 ° C. for 1 to 5 hours, or the above general formula (2) A method of adding a solid or aqueous solution of an alkali metal hydroxide to a halohydrin etherified compound and reacting again at 20 to 120 ° C. for 1 to 10 hours to dehydrohalogenate (ring closure) may be used.
[0035]
Furthermore, alcohols such as methanol, ethanol, isopropyl alcohol and butanol, ketones such as acetone and methyl ethyl ketone, ethers such as dioxane, aprotic polar solvents such as dimethyl sulfone and dimethyl sulfoxide, etc. are used in order to facilitate the reaction. It is preferable to carry out the reaction by adding.
The amount of the solvent used is usually 5 to 50% by weight, preferably 10 to 30% by weight, based on the amount of epihalohydrin. Moreover, when using an aprotic polar solvent, it is 5-100 weight% normally with respect to the quantity of epihalohydrin, Preferably it is 10-60 weight%.
[0036]
After the epoxidation reaction product is washed with water or without washing with water, epihalohydrin and other added solvents are removed at 110 to 250 ° C. under a pressure of 10 mmHg or less under reduced pressure. Further, in order to obtain an epoxy resin with less hydrolyzable halogen, the crude epoxy resin obtained after recovering epihalohydrin or the like is dissolved again in a solvent such as toluene or methyl isobutyl ketone, and an alkali such as sodium hydroxide or potassium hydroxide is obtained. An aqueous solution of a metal hydroxide can be added and further reacted to ensure ring closure. In this case, the amount of alkali metal hydroxide used is usually 0.5 to 10 mol, preferably 1.2 to 5.0 mol, per 1 mol of hydrolyzable chlorine remaining in the crude epoxy resin. The reaction temperature is usually 50 to 120 ° C., and the reaction time is usually 0.5 to 3 hours. For the purpose of improving the reaction rate, a phase transfer catalyst such as a quaternary ammonium salt or crown ether may be present. The amount of the phase transfer catalyst used is preferably in the range of 0.1 to 3.0% by weight based on the crude epoxy resin.
[0037]
After completion of the reaction, the produced salt is removed by filtration, washing with water, and the solvent of toluene, methyl isobutyl ketone, etc. is distilled off under heating and reduced pressure to obtain the epoxy resin of the present invention.
[0038]
Next, the epoxy resin composition of the present invention will be described. The epoxy resin composition of the present invention, the general formula (1), an epoxy resin represented by the general formula (2), or the general formula (3), the general formula (4) or the structural formula (9) to An epoxy resin obtained by reacting the condensate represented by ( 11 ) with epihalohydrin and a curing agent are contained as essential components.
[0039]
Further, the epoxy resin molding material of the present invention can be used in combination with other epoxy resins. When used in combination, the proportion of the aforementioned epoxy resin in the total epoxy resin is preferably 30% by weight or more, and particularly preferably 40% by weight or more. As other epoxy resins that can be used in combination with the epoxy resin of the present invention, all publicly known epoxy resins can be used, but bisphenol A type epoxy resins, bisphenol F type epoxy resins, biphenyl type epoxy resins are exemplified. , Tetramethylbiphenyl type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene-phenol addition reaction type epoxy resin, phenol aralkyl type epoxy resin , Naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, naphthol-phenol co-condensed novolac type epoxy resin, naphthol-cresol co-condensed novolac type epoxy resin, aromatic Hydrocarbon formaldehyde resin-modified phenol resin type epoxy resin, biphenyl-modified novolak type epoxy resin, do not tetrabromobisphenol A type epoxy resins and brominated phenol novolak type epoxy resins are not limited thereto. These epoxy resins may be used alone or in combination of two or more.
[0040]
In addition, polyvalent aromatic hydroxyl group-containing compounds represented by the following general formula ( 5 )

( Wherein R _{1 to} R ₃ represent a hydrogen atom, a methyl group, a phenylethylidene group, or a phenyl group, which may be the same as or different from each other , and n represents a number of repeating units of more than 1). Epoxy resins obtained by reaction of polyaromatic hydroxyl group-containing compounds with epihalohydrins are also included in the usable epoxy resins.
[0041]
As the curing agent used in the present invention, for example, all known and publicly known curing agents such as amine compounds, acid anhydride compounds, amide compounds, phenol compounds and the like can be used. For example, polyamide resin synthesized from diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, and linolenic acid and ethylenediamine, phthalic anhydride, trimellitic anhydride, pyrone anhydride Mellitic acid, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolac resin, cresol novolac resin, aromatic hydrocarbon formaldehyde resin modified Phenol resin, dicyclopentadiene phenol addition type resin, phenol aralkyl resin, naphthol aralkyl resin, trimethylol methane resin, tetraphenol Polyphenol compounds such as roll ethane resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin, biphenyl-modified phenol resin, aminotriazine-modified phenol resin, and the like, and modified products thereof, Examples include, but are not limited to, imidazole, BF ₃ -amine complexes, guanidine derivatives, and the like. These may be used alone or in combination of two or more. Among these, phenol novolak resin, cresol novolak resin, aromatic hydrocarbon formaldehyde resin modified phenol resin, phenol aralkyl resin, naphthol aralkyl resin, naphthol novolak resin, naphthol-phenol co-condensed novolak resin, naphthol-cresol co-condensed novolak resin Biphenyl-modified phenolic resins and aminotriazine-modified phenolic resins are preferred because of their excellent flame retardancy, among which aromatic hydrocarbon formaldehyde resin-modified phenolic resins, phenol aralkyl resins, naphthol aralkyl resins, biphenyl-modified phenolic resins, aminotriazine modified Polyvalent aromatics having a structure in which hydroxyl-containing aromatic nuclei are linked to a hydroxyl group-free aromatic skeleton-containing group such as a phenol resin Sex hydroxyl group-containing compound is preferable because of particularly excellent in flame retardancy.
[0042]
Moreover, as said polyvalent aromatic hydroxyl-containing compound, the compound represented by the said General formula ( 3 ), ( 4 ) and (9)-( 12 ) is also contained.
[0043]
Furthermore, the polyvalent aromatic hydroxyl group-containing compound represented by the general formula ( 5 ) is also included.
[0044]
The use amount of the curing agent used in the present invention is such that the active hydrogen group in the curing agent is 0.7 per 1 equivalent of the epoxy group of the epoxy resin from the point that the curing reaction is completed and good cured properties are obtained. An amount of ~ 1.5 equivalents is preferred.
[0045]
Moreover, a hardening accelerator can also be used suitably for the epoxy resin composition of this invention. As the curing accelerator, any known and conventional ones can be used. Examples thereof include phosphorus compounds, tertiary amines, imidazoles, organic acid metal salts, Lewis acids, amine complex salts, and the like. Two or more types can be used together. For semiconductor sealing materials, phosphorus-based triphenylphosphine, amine-based 1,8-bicyclo- [5,4,0] -undecene (DBU), etc. are curable, heat-resistant, electrical characteristics, moisture-resistant reliability It is preferable because of its excellent properties.
[0046]
Moreover, an inorganic filler can also be used suitably for the epoxy resin composition of this invention. Examples of the inorganic filler used in the present invention include fused silica, crystalline silica, alumina, silicon nitride, and aluminum nitride. When the blending amount of the inorganic filler is particularly large, it is common to use fused silica. The fused silica can be used in either a crushed shape or a spherical shape, but in order to increase the blending amount of the fused silica and to suppress an increase in the melt viscosity of the molding material, it is preferable to mainly use a spherical shape. In order to further increase the blending amount of the spherical silica, it is preferable to adjust so that the particle size distribution of the spherical silica becomes wider. In view of flame retardancy, the filling rate is preferably as high as possible, particularly preferably 65% by weight or more, and more preferably 85% by weight or more based on the total amount of the epoxy resin composition.
[0047]
Moreover, a flame retardant or a flame retardant imparting agent can be appropriately used in the epoxy resin composition of the present invention. As the flame retardant or flame retardant imparting agent used in the present invention, all known ones can be used. Examples thereof include phosphorus atom-containing compounds, nitrogen atom-containing compounds, organosilicon compounds, and inorganic flame retardant compounds. .
[0048]
If those specific examples are given, examples of the phosphorus atom-containing compound include organic phosphorus compounds such as red phosphorus, ammonium polyphosphate and phosphate ester compounds, phosphinic acid, and phosphazene compounds. As used herein, red phosphorus may be subjected to a surface treatment, for example, coated with a metal hydroxide film such as magnesium hydroxide, zinc hydroxide, titanium hydroxide, magnesium hydroxide, Thermosetting on a coating of metal hydroxide selected from a coating made of zinc hydroxide, titanium hydroxide, etc. and a thermosetting resin, magnesium hydroxide, zinc hydroxide, titanium hydroxide, etc. Any of the resin coatings that are doubly coated can be used. Moreover, as said phosphorus compound, you may have functional groups, such as phosphoric acid amide, an amino group, a phenolic hydroxyl group, an epoxy group. The addition amount of these phosphorus compounds is preferably 0.1% by weight or more from the viewpoint that the effect of improving the flame retardancy becomes remarkable with respect to all the other compounding ingredients excluding the fillers exemplified above. In view of the remarkable effect of improving the flame retardancy, the amount of phosphorus atoms is small and there is no bleeding effect of the phosphorus atom-containing compound, and the flame resistance improvement effect is remarkable, and the moldability and moisture resistance are preferable. It is preferably 5.0% by weight or less from the viewpoint of good and no bleeding of the phosphorus atom-containing compound. More preferably, it is in the range of 0.2 to 3.0% by weight.
[0049]
Examples of the nitrogen atom-containing compound include compounds derived from melamine, benzoguanamine, acetoguanamine and the above-described triazine compounds, melamine sulfate, aminotriazine sulfate, melamine cyanurate, cyanuric acid and the like, and these include functional groups such as phenolic hydroxyl groups. It may have a group. The addition amount of these nitrogen atom-containing compounds is 0.1 from the point that the effect of improving flame retardancy is significant with the amount of nitrogen atoms with respect to all the other compounding ingredients except the fillers exemplified above. It is preferably 20% by weight or less, more preferably 20% by weight or less, and still more preferably in the range of 1-10% by weight.
[0050]
Examples of the organosilicon compound include compounds containing an alkyl group such as a phenyl group or a methyl group, and these may have a functional group such as a phenolic hydroxyl group, an amino group, or an epoxy group. The addition amount of these organosilicon compounds is 0.1 or more because the effect of improving flame retardancy is remarkable with the amount of nitrogen atoms relative to all the other compounding ingredients except the fillers exemplified above. It is preferably 20% by weight or less from the viewpoint of good adhesion. Furthermore, it is preferably in the range of 1 to 10% by weight.
[0051]
Examples of inorganic flame retardant compounds include hydrated metals such as aluminum hydroxide, magnesium hydroxide, dolomite, hydrotalcite, calcium hydroxide, barium hydroxide, basic magnesium carbonate, zirconium hydroxide, and tin oxide hydrates. Compounds, silica, aluminum oxide, iron oxide, titanium oxide, manganese oxide, magnesium oxide, zirconium oxide, zinc oxide, molybdenum oxide, cobalt oxide, bismuth oxide, chromium oxide, tin oxide, antimony oxide, nickel oxide, copper oxide, Metal oxide such as tungsten oxide, metal surface such as aluminum, iron, ferrocene, titanium, manganese, zinc, molybdenum, etc., coated with resin or inorganic material, cobalt metal such as cobalt, cobalt naphthenic acid complex, cobalt ethylenediamine complex Complex, boric acid, borax Boric acid metal salts such as zinc borate, zinc carbonate, magnesium carbonate, calcium carbonate, barium carbonate, and the like. As the inorganic flame retardant compound, those whose surface is coated with a resin or an inorganic substance can be used, and the reliability when the sealing material such as adhesion is improved by the surface coating is improved. The added amount of these inorganic flame retardant compounds is preferably 0.1% by weight or more from the viewpoint that the effect of improving flame retardancy is remarkable with respect to all the other components except the fillers exemplified above. From the viewpoint of good moldability, it is preferably 10% by weight or less. More preferably, it is in the range of 0.1 to 5% by weight.
[0052]
Moreover, various compounding agents, such as a silane coupling agent, a mold release agent, and a pigment, can be added to the epoxy resin composition of this invention as needed.
[0053]
The epoxy resin composition blended as described above can be used as an epoxy resin molding material. The said epoxy resin molding material is obtained by mixing each component uniformly. The epoxy resin composition of the present invention, in which the epoxy resin of the present invention, a curing agent and, if necessary, a curing accelerator are blended, can be easily made into a cured product by a method similar to a conventionally known method.
[0054]
For example, in order to prepare an epoxy resin molding material for a semiconductor sealing material, an epoxy resin and a compounding agent such as a curing agent and a filler are used as necessary using an extruder, a kneader, a roll, etc. It is sufficient to obtain a melt-mixed epoxy resin composition by thoroughly mixing until uniform. At that time, silica is usually used as the filler, but the filling rate is in the range of 30 to 95% by weight based on the total amount of the epoxy resin composition, and the flame resistance, moisture resistance and solder crack resistance are improved. In order to lower the linear expansion coefficient, it is preferably 65% by weight or more, and 80% by weight or more is particularly preferable in order to significantly increase the effects.
[0055]
Further, in order to prepare an epoxy resin molding material for a circuit board material, the epoxy resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone and used as a varnish-like composition. be able to. In this case, the solvent is used in an amount of 10 to 70% by weight, preferably 15 to 65% by weight, particularly preferably 20 to 50% by weight in the mixture of the epoxy resin composition of the present invention and the solvent. In addition, as said circuit board material, a printed wiring board, a printed circuit board, a flexible printed wiring board, a buildup wiring board etc. are mentioned, for example.
[0056]
The cured product of the present invention can be obtained by thermally curing the epoxy resin composition of the present invention, and has forms such as a molded product, a laminate, a cast product, an adhesive, a coating film, and a film. For example, in the case of a melt-mixed type composition, a cured product can be obtained by heating the composition at 80 to 200 ° C. for 2 to 10 hours using a casting, transfer molding machine, injection molding machine or the like. The semiconductor package molding corresponds to this. In the case of a varnish-like composition, it is impregnated into a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc. and dried by heating to obtain a prepreg, which is subjected to hot press molding. A cured product can be obtained, and the laminated material for printed wiring board material corresponds to this.
[0057]
The above epoxy resin composition can be used as a flame retardant epoxy resin which does not substantially contain a halogen compound. The flame-retardant epoxy resin containing substantially no halogen compound of the present invention means an epoxy resin composition exhibiting flame retardancy even if it does not contain a halogen compound added for the purpose of flame retardancy. Therefore, a trace impurity halogen of about 5000 ppm or less contained in an epoxy resin derived from epihalohydrins is different from this meaning, and may be included temporarily.
[0058]
【Example】
Next, the present invention will be specifically described with reference to examples and comparative examples. In the following, parts and% are parts by weight unless otherwise specified.
[0059]
Example 1
While subjecting a flask equipped with a thermometer, a dropping funnel, a condenser, and a stirrer to nitrogen purge, 366 g (3.0 mol) of 2,6-xylenol, 273 g (1.5 mol) of 4-biphenylaldehyde, and 500 g of toluene were added. Added and dissolved. Next, 13.7 g of paratoluenesulfonic acid was added, and the temperature was raised to the ring temperature and held. Distilled toluene and water were separated in a Dean trap, and only toluene was returned to the system. After stirring for 5 hours as it was, when cooled to room temperature, crystals precipitated. The crystals were separated by filtration, washed with toluene and methanol, and then dried to obtain 505 g of the desired bisphenol compound. The purity of the obtained crystal was 99% by GPC analysis. From the NMR spectrum (C ¹³ , solvent DMSO, FIG. 1), IR spectrum (KBr method, FIG. 2) and mass spectrum (FD-MS, FIG. 3), It was confirmed that it was a bisphenol compound represented by the structural formula (9).
[0060]
Next, 204 g of the obtained bisphenol compound (hydroxyl group 1.0 equivalent), 463 g of epichlorohydrin (5.0 mol), 53 g of n-butanol, and 2.3 g of tetraethylbenzylammonium chloride were charged and dissolved. After raising the temperature to 65 ° C., the pressure was reduced to the azeotropic pressure, and 82 g (1.0 mol) of 49% aqueous sodium hydroxide solution was added dropwise over 5 hours, and then the mixture was stirred for 0.5 hours under the same conditions. Continued. During this time, the distillate distilled azeotropically was separated by a Dean-Stark trap, the aqueous layer was removed, and the reaction was carried out while returning the oil layer to the reaction system. Thereafter, unreacted epichlorohydrin was distilled off under reduced pressure. 550 g of methyl isobutyl ketone and 55 g of n-butanol were added to the crude epoxy resin thus obtained and dissolved. Further, 15 g of a 10% aqueous sodium hydroxide solution was added to this solution and reacted at 80 ° C. for 2 hours. Then, washing with 100 g of water was repeated three times until the pH of the washing solution became neutral. Next, the system was dehydrated by azeotropic distillation, and after passing through microfiltration, the solvent was distilled off under reduced pressure to obtain 238 g of an epoxy resin (A) represented by the structural formula (3). The epoxy equivalent of the obtained epoxy resin was 285 g / eq. The melt viscosity (ICI viscometer) at a softening point of 84 ° C. and 150 ° C. was 2.3 ps. This epoxy resin has an NMR spectrum (C ¹³ , solvent DMSO, FIG. 4), an IR spectrum (FIG. 5), a mass spectrum (FD-MS, FIG. 6), and GPC (Tosoh HLC-802A, column: TSK gel G4, 3, 2, 2HXL, detector RI, solvent THF, FIG. 7), it was confirmed to have the chemical structure represented by the structural formula (3). (R is an average value of 0.1)
[0061]
Synthesis example 1
While performing nitrogen gas purging on a flask equipped with a thermometer, a dropping funnel, a condenser, and a stirrer, 176 g of a bisphenol compound represented by the following structural formula (40) (1.0 equivalent of hydroxyl group), 370 parts of epichlorohydrin ( 4.0 mol), 42 g of n-butanol, and 2.3 g of tetraethylbenzylammonium chloride were charged and dissolved. After raising the temperature to 65 ° C., the pressure was reduced to an azeotropic pressure, and 82 g (1.0 mol) of a 49% aqueous sodium hydroxide solution was added dropwise over 5 hours, and then the mixture was stirred for 0.5 hours under the same conditions. Continued. During this time, the distillate distilled azeotropically was separated by a Dean-Stark trap, the aqueous layer was removed, and the reaction was carried out while returning the oil layer to the reaction system. Thereafter, unreacted epichlorohydrin was distilled off under reduced pressure. 490 g of methyl isobutyl ketone and 49 g of n-butanol were added to the crude epoxy resin thus obtained and dissolved. Further, 15 g of a 10% aqueous sodium hydroxide solution was added to this solution and reacted at 80 ° C. for 2 hours. Then, washing with 100 g of water was repeated three times until the pH of the washing solution became neutral. Next, the system was dehydrated by azeotropic distillation, and after microfiltration, the solvent was distilled off under reduced pressure to obtain 212 g of an epoxy resin (B) represented by the following structural formula (41). The epoxy equivalent of the obtained epoxy resin was 247 g / eq. The melt viscosity (ICI viscometer) at a softening point of 56 ° C. and 150 ° C. was 0.3 ps.
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Examples 2-3 and Comparative Examples 1-6
As compared with the epoxy resin (A) obtained in Example 1, the epoxy resin (B) synthesized in Synthesis Example 1 and a bisphenol A type epoxy resin (EPICLON 1055: manufactured by Dainippon Ink & Chemicals, Inc., epoxy equivalent 475 g) eq.), cresol novolac type epoxy resin (EPICLON N-665-EXP-S: manufactured by Dainippon Ink and Chemicals, epoxy equivalent 202 g / eq.), and phenol novolac resin (PHENOLITE TD-2131: Dainippon Ink & Chemicals, softening point 80 ° C., hydroxyl equivalent 104 g / eq.), Phenol aralkyl resin (Millex XL-225-2L: Mitsui Chemicals, softening point 74 ° C., hydroxyl equivalent 175 g / eq.) Using triphenylphosphine (TPP) as a curing accelerator and fused silica (manufactured by Tatsumori Co., Ltd., RD-8) as an inorganic filler, blended in the composition shown in Table 1, and using two rolls To obtain the desired composition was 10 minutes melt-kneaded at a temperature of 100 ° C.. This was press-molded at 180 ° C. for 10 minutes, then further cured at 180 ° C. for 5 hours, and then subjected to a flame retardancy test. The test was performed based on the UL-94V test, and the evaluation was made by comparing the total burning time of five test pieces.
A test piece having a thickness of 1/16 inch was used.
The flame retardant test results are shown in Table 1.
[0062]
[Table 1]

[0063]
【The invention's effect】
The epoxy resin of the present invention is excellent in flame retardancy, and can impart excellent flame retardancy to the cured product without containing a halogen compound. It is extremely useful as an epoxy resin material in the field of electronic materials such as semiconductor encapsulating materials and printed wiring boards for environmental problems.
[Brief description of the drawings]
1 is a ¹³ C nuclear magnetic resonance absorption spectrum of a condensate of an aromatic hydroxyl group-containing compound according to the present invention and a biphenyl skeleton-containing carbonyl compound obtained in Example 1. FIG.
2 is an infrared absorption spectrum of a condensate of an aromatic hydroxyl group-containing compound and a biphenyl skeleton-containing carbonyl compound according to the present invention obtained in Example 1. FIG.
3 is a mass spectrum of a condensate of an aromatic hydroxyl group-containing compound according to the present invention and a biphenyl skeleton-containing carbonyl compound obtained in Example 1. FIG.
4 is a ¹³ C nuclear magnetic resonance absorption spectrum of a condensate of an epoxy resin according to the present invention obtained in Example 1. FIG.
5 is an infrared absorption spectrum of the epoxy resin according to the present invention obtained in Example 1. FIG.
6 is a mass spectrum of the epoxy resin according to the present invention obtained in Example 1. FIG.
7 is a GPC chart of the epoxy resin according to the present invention obtained in Example 1. FIG.

Claims (16)

General formula (1)

(Wherein R _{1 to} R ₃ represent a hydrogen atom, a methyl group, a phenylethylidene group, or a phenyl group, which may be the same or different from each other, and at least one of R _{1 to} R ₃ is a methyl group, a phenyl group, Group, a phenylethylidene group, R ₇ represents a hydrogen atom or a methyl group, and q represents an average value of 0 to 10). Structural formula (2)

The epoxy resin of Claim 1 which is an epoxy resin represented by these. (In the formula, r is an average value and represents an integer of 0 to 10).   The epoxy resin according to claim 1 or 2, wherein the melt viscosity at 150 ° C is 0.1 dPa · s to 5 dPa · s. General formula (3)

(Wherein R _{1 to} R ₃ are the same as or different from each other, a hydrogen atom, a methyl group,
It represents a phenylethylidene group or a phenyl group, and at least one of R _{1 to} R ₃ represents a methyl group, a phenyl group, or a phenylethylidene group . An epoxy resin obtained by reacting an aromatic diol compound represented by) and an epihalohydrin. The aromatic diol compound is represented by the general formula (4)

The epoxy resin of Claim 4 which is a compound represented by (In formula, R < ₁ > represents a methyl group, a phenyl ethylidene group, or a phenyl group.).   The epoxy resin according to claim 4 or 5, which has a melt viscosity at 150 ° C of 0.1 dPa · s to 5 dPa · s.   An epoxy resin composition comprising the epoxy resin according to any one of claims 1 to 6 and a curing agent as essential components.   The epoxy resin composition according to claim 7, wherein the curing agent is a polyvalent aromatic hydroxyl group-containing compound having a structure in which a hydroxyl group-containing aromatic nucleus is linked with a hydroxyl group-free aromatic skeleton-containing group as a nodule group. The epoxy resin composition according to claim 8, wherein the polyvalent aromatic hydroxyl group-containing compound is a phenol aralkyl resin.   The epoxy resin composition according to any one of claims 8 to 9, which is prepared for a semiconductor sealing material.   Furthermore, the epoxy resin composition as described in any one of Claims 7-10 which uses an inorganic filler as an essential component.   The epoxy resin composition according to claim 11, wherein a filling rate of the inorganic filler in the epoxy resin composition is 65 parts by weight or more per epoxy resin composition.   The epoxy resin composition according to claim 7, which is prepared for a circuit board material. A flame retardant epoxy resin composition comprising the epoxy resin according to any one of claims 1 to 6 and a curing agent as essential components and substantially free of a halogen compound.   Hardened | cured material obtained by hardening | curing the epoxy resin composition as described in any one of Claims 7-14. The following general formula (3)

(Wherein R _{1 to} R ₃ are the same as or different from each other, a hydrogen atom, a methyl group,
It represents a phenylethylidene group or a phenyl group, and at least one of R _{1 to} R ₃ represents a methyl group, a phenyl group, or a phenylethylidene group. An aromatic diol compound represented by:

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