JP3852789B2 - Epoxy resin, epoxy resin composition and cured product thereof - Google Patents

Description

【０００７】
（式中、ｎは平均値を示し０〜１０の値を取る。Ｐ、Ｒは水素原子、ハロゲン原子、炭素数１〜８のアルキル基、アリール基のいずれかを表し個々のＰ、Ｒは互いに同一であっても異なっていてもよい。Ｇはグリシジル基を表す。）
で表されるエポキシ樹脂、
【０００８】
（２）上記（１）記載のエポキシ樹脂および硬化剤、必要により硬化促進剤を含有するエポキシ樹脂組成物、
（３）上記（２）記載のエポキシ樹脂組成物を硬化してなる硬化物、
を提供するものである。
【０００９】
【発明の実施の形態】
式（１）で表される化合物は例えば、式（２）
【００１０】
【化３】

【００１１】
（式中、ｎ、Ｐ、Ｒは式（１）におけるのと同じ意味を表す。）
【００１２】
で表される化合物とエピハロヒドリンとの反応をアルカリ金属水酸化物の存在下で行うことにより得ることができる。
【００１３】
式（２）で表される化合物は例えば式（３）
【００１４】
【化４】

【００１５】
（式中、Ｘはハロゲン原子、水酸基、低級アルコキシ基を表す。Ｒは式（１）におけるのと同じ意味を表す。）で表される化合物とフェノール類とを酸触媒の存在下で縮合反応させることにより得ることができる。
【００１６】
式（３）のＸにおいてハロゲン原子としては塩素原子、臭素原子などが、低級アルキル基としてはメチル基、エチル基、ｔ−ブチル基などが、低級アルコキシ基としてはメトキシ基、エトキシ基などがそれぞれ好ましい基として挙げられる。
【００１７】
ここでフェノール類とはフェノール性水酸基を１分子中に１個有する芳香族化合物が挙げられ、その用いうる具体例としては、フェノール、クレゾール、エチルフェノール、ｎ−プロピルフェノール、イソブチルフェノール、ｔ−ブチルフェノール、オクチルフェノール、ノニルフェノール、キシレノール、メチルブチルフェノール、ジ−ｔ−ブチルフェノール等のアルキルフェノールの各種ｏ−、ｍ−、ｐ−異性体、またはビニルフェノール、アリルフェノール、プロペニルフェノール、エチニルフェノールの各種ｏ−、ｍ−、ｐ−異性体、またはシクロペンチルフェノール、シクロヘキシルフェノール、シクロヘキシルクレゾール等のシクロアルキルフェノール、またはフェニルフェノールなどの置換フェノール類が挙げられる。これらのフェノール類は１種類のみを用いてもよく、２種類以上を組み合わせて用いてもよい。
【００１８】
上記縮合反応を行う場合フェノール類の使用量は式（３）で表される化合物１モルに対して好ましくは０．５〜２０モル、特に好ましくは２〜１５モルである。
【００１９】
上記縮合反応においては酸触媒を用いるのが好ましく、酸触媒としては種々のものが使用できるが塩酸、硫酸、ｐ−トルエンスルホン酸、シュウ酸等の無機あるいは有機酸、三弗化ホウ素、無水塩化アルミニウム、塩化亜鉛等のルイス酸などが好ましく、特にｐ−トルエンスルホン酸、硫酸、塩酸が好ましい。これら酸触媒の使用量は特に限定されるものではないが、式（３）で表される化合物の０．１〜３０重量％用いるのが好ましい。
【００２０】
上記縮合反応は無溶剤下で、あるいは有機溶剤の存在下で行うことができる。有機溶剤を使用する場合の具体例としてはトルエン、キシレン、メチルイソブチルケトンなどが挙げられる。有機溶剤の使用量は仕込んだ原料の総重量に対して５０〜３００重量％が好ましく、特に１００〜２５０重量％が好ましい。反応温度は４０〜１８０℃の範囲が好ましく、反応時間は１〜８時間が好ましい。
【００２１】
反応終了後、洗浄液のｐＨ値が３〜７、好ましくは５〜７になるまで水洗処理を行う。この場合必要により水酸化ナトリウム、水酸化カリウムなどのアルカリ金属水酸化物、水酸化カルシウム、水酸化マグネシウムなどのアルカリ土類金属水酸化物、アンモニア、リン酸二水素ナトリウムさらにはジエチレントリアミン、トリエチレンテトラミン、アニリン、フェニレンジアミンなどの有機アミンなど様々な塩基性物質等を中和剤として用いて処理してもよい。水洗処理は常法にしたがって行えばよい。例えば反応混合物中に上記中和剤を溶解した水を加え分液抽出操作をくり返す。
【００２２】
水洗処理を行った後、減圧加熱下で未反応のジヒドロキシベンゼン類及び溶剤を留去し生成物の濃縮を行い、式（２）で表される化合物を得ることが出来る。
【００２３】
式（２）で表される化合物から本発明のエポキシ樹脂を得る方法としては公知の方法が採用できる。例えば前記で得られた式（２）で表される化合物と過剰のエピクロルヒドリン、エピブロムヒドリン等のエピハロヒドリンとの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あらかじめ添加し、または添加しながら２０〜１２０℃の温度で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。
【００２４】
本発明の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。
【００２５】
また、式（２）で表される化合物とエピハロヒドリンと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、２０〜１２０℃の温度で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。
【００２６】
通常これらの反応において使用されるエピハロヒドリンの量は式（２）で表される化合物の水酸基１当量に対し通常１〜２０モル、好ましくは２〜１０モルである。アルカリ金属水酸化物の使用量は式（２）で表される化合物の水酸基１当量に対し０．８〜１５モル、好ましくは０．９〜１１モルである。また、４級アンモニウム塩の使用量は式（２）の化合物の水酸基１当量に対して、通常１〜１０ｇ、好ましくは２〜８ｇである。更に、反応を円滑に進行させるためにメタノール、エタノールなどのアルコール類の他、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。
【００２７】
アルコール類を使用する場合、その使用量はエピハロヒドリンの量に対し２〜２０重量％、好ましくは４〜１５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５〜１００重量％、好ましくは１０〜９０重量％である。
【００２８】
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、得られたエポキシ樹脂をトルエン、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を行い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エポキシ化に使用した式（２）で表される化合物の水酸基１当量に対して好ましくは０．０１〜０．３モル、特に好ましくは０．０５〜０．２モルである。反応温度は５０〜１２０℃、反応時間は通常０．５〜２時間である。
【００２９】
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。
【００３０】
本発明のエポキシ樹脂組成物は本発明のエポキシ樹脂、硬化剤、必要により硬化促進剤等を均一に混合することにより得ることができる。本発明のエポキシ樹脂組成物において、エポキシ樹脂として本発明のエポキシ樹脂以外のエポキシ樹脂を併用することも可能である。他のエポキシ樹脂を併用する場合、全エポキシ樹脂中の本発明のエポキシ樹脂の占める割合は、２０重量％以上が好ましい。
本発明のエポキシ樹脂組成物において、硬化剤としてはアミン系化合物、酸無水物系化合物、アミド系化合物、フェノ−ル系化合物などが使用できる。用いうる硬化剤の具体例としては、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−ルノボラック、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。また本発明のエポキシ樹脂の原料として用いた式（２）で表される化合物も硬化剤として用いることが出来る。これらの硬化剤はそれぞれ単独で用いてもよいし、２種以上組み合わせて用いてもよい。
【００３１】
これらの硬化剤の使用量は、エポキシ樹脂のエポキシ基１当量に対して０．７〜１．２当量が好ましい。エポキシ基１当量に対して、０．７当量に満たない場合、あるいは１．２当量を超える場合、いずれも硬化が不完全となり良好な硬化物性が得られない恐れがある。
【００３２】
また上記硬化剤を用いる際に硬化促進剤を併用しても差し支えない。用いうる硬化促進剤の具体例としては２−メチルイミダゾール、２−エチルイミダゾール、２−エチル−４−メチルイミダゾール等のイミダゾ−ル類、２−（ジメチルアミノメチル）フェノール、１，８−ジアザ−ビシクロ（５，４，０）ウンデセン−７等の第３級アミン類、トリフェニルホスフィン等のホスフィン類、オクチル酸スズなどの金属化合物などが挙げられる。硬化促進剤は、エポキシ樹脂１００重量部に対して０．１〜５．０重量部が必要に応じ用いられる。さらに、本発明のエポキシ樹脂組成物には、必要に応じてシリカ、アルミナ、タルク等の充填材や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。
【００３３】
本発明のエポキシ樹脂組成物は、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その硬化物とすることができる。
例えば本発明のエポキシ樹脂と硬化剤、充填剤及びその他の添加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本発明のエポキシ樹脂組成物を得、そのエポキシ樹脂組成物を溶融後注型あるいはトランスファ−成形機などを用いて成形し、さらに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る。
【００３４】
また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、ガラス繊維、カ−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得たプリプレグを熱プレス成形して硬化物を得ることもできる。
【００３５】
この際の希釈溶剤は本発明のエポキシ樹脂組成物と該希釈溶剤の混合物中で通常１０〜７０重量％、好ましくは１５〜６５重量％を占める量を使用する。
【００３６】
こうして得られる硬化物は耐熱性、耐水性及び機械的強度に優れているため、耐熱性、耐水性の要求される広範な分野で用いることができる。具体的には封止材料、積層板、絶縁材料などのあらゆる電気・電子材料として有用である。また、成型材料、接着剤、塗料などの分野にも用いることができる。
【００３７】
【実施例】
次に本発明を実施例、比較例により更に具体的に説明するが、以下において部は特に断わりのない限り重量部を意味する。
【００３８】
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、下記式（４）
【００３９】
【化５】

【００４０】
で表される化合物２４２部、フェノール２８２部を仕込み、室温下、窒素を吹き込みながら撹拌した。ｐ−トルエンスルホン酸（１水和物）２．８部を発熱に注意しながら液温が５０℃を超えないようにゆっくり添加した。その後油浴中で１１０℃まで加熱し、２時間反応させた。反応終了後、更にメチルイソブチルケトン１０００ｍｌを加え、分液ロートに移し水洗した。洗浄水が中性を示すまで水洗後有機層から溶媒及び未反応物を加熱減圧下に除去し、軟化点が１０８℃の樹脂状化合物２９９部を得た。この化合物について溶媒にテトラヒドロフランを用いてＧＰＣ分析、マススペクトル（ＦＡＢ−ＭＳ）分析によって分析した結果、この化合物は下記式（５）
【００４１】
【化６】

【００４２】
で表される化合物であることが確認された。ＧＰＣ分析の結果から水酸基当量を算出すると２２８ｇ／ｅｑとなった。またｎの平均値は２．１であった。
【００４３】
ついで、温度計、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上記反応で得られた化合物２２８部、エピクロルヒドリン３７０部、ジメチルスルホキシド９２．５部を仕込み溶解させた。更に５０℃に加熱しフレーク状水酸化ナトリウム（純分９９％）４０．４部を９０分かけて分割添加し、その後更に６０℃で２時間、７０℃で１時間反応させた。反応終了後、１３０℃で加熱減圧下ジメチルスルホキシド及びエピクロルヒドリンを留去し、残留物に５６８部のメチルイソブチルケトンを加え溶解した。
【００４４】
更にこのメチルイソブチルケトンの溶液を７０℃に加熱し３０重量％の水酸化ナトリウム水溶液１０部を添加し１時間反応させた後、水洗を３回繰り返しｐＨを中性とした。更に水層は分離除去し、ロータリエバポレーターを使用して油層から加熱減圧下メチルイソブチルケトンを留去し、下記式（６）
【００４５】
【化７】

【００４６】
（式中、Ｇはグリシジル基を表し、ｎの平均値は２．１である。）
で表される本発明のエポキシ樹脂（Ａ）２６７部を得た。得られたエポキシ樹脂の軟化点は８５．３℃、エポキシ当量は２９５ｇ／ｅｑであった。
【００４７】
実施例２
フェノールの代わりにｏ−クレゾール４３２部を用いた以外は実施例１と同様に反応を行い軟化点が１０１．５℃の樹脂状化合物３３７部を得た。この化合物について溶媒にテトラヒドロフランを用いてＧＰＣ分析、マススペクトル（ＦＡＢ−ＭＳ）分析によって分析した結果、この化合物は下記式（７）
【００４８】
【化８】

【００４９】
で表される化合物であることが確認された。ＧＰＣ分析の結果から水酸基当量を算出すると２２９ｇ／ｅｑとなった。またｎの平均値は１．１であった。次いで式（７）で表される化合物２２９部を用いた以外は実施例１と同様にエポキシ化反応を行い下記式（８）
【００５０】
【化９】

【００５１】
（式中、Ｇはグリシジル基を表し、ｎの平均値は１．１である。）
で表される本発明のエポキシ樹脂（Ｂ）２７３部を得た。得られたエポキシ樹脂の軟化点は８２．２℃、エポキシ当量は２９３ｇ／ｅｑであった。
【００５２】
比較例１
特開平５−１１７３５０号の実施例１に従い下記式（９）
【００５３】
【化１０】

【００５４】
で示される化合物を得た。
【００５５】
次いで式（９）の化合物を用いて同公報実施例２に従いエポキシ樹脂（Ｃ）を得た。
【００５６】
実施例３〜４、比較例２
本発明のエポキシ樹脂（Ａ）、（Ｂ）、比較用の前記エポキシ樹脂（Ｃ）、硬化剤としてフェノールノボラック（水酸基当量１０６ｇ／ｅｑ、軟化点８０．２℃）、硬化促進剤としてトリフェニルホスフィン（ＴＰＰ）を用い、表１の配合物の組成の欄に示す組成で配合して、７０℃で１５分ロールで混練し、１５０℃、成形圧力５０ｋｇ／ｃｍ² で１８０秒間トランスファー成形して、その後１６０℃で２時間、更に１８０℃で８時間硬化せしめて試験片を作成し、ガラス転移点、吸水率を測定した。結果を表１に示す。尚、ガラス転移点、吸水率及び曲げ強度の測定条件は次の通りである。また、表中、配合物の組成の欄の数値は重量部を示す。
【００５７】
ガラス転移点
熱機械測定装置（ＴＭＡ）：真空理工（株）製 ＴＭ−７０００
昇温速度：２℃／ｍｉｎ
吸水率

１００℃の水中で２４時間煮沸した後の重量増加率（％）
曲げ強度
ＪＩＳ Ｋ−６９１１に準拠し測定
【００５８】
【表１】

【００５９】
表１より本発明のエポキシ樹脂の硬化物は、公知のビフェニル骨格を有するエポキシ樹脂の硬化物に較べ、高いガラス転移点、低い吸水率及び、高い機械強度を示した。
【００６０】
【発明の効果】
本発明のエポキシ樹脂は耐熱性及び耐水性及び機械的強度に優れた特性を兼ね備えた硬化物を与えることができ、成形材料、注型材料、積層材料、塗料、接着剤、レジストなど広範囲の用途にきわめて有用である。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an epoxy resin and an epoxy resin composition that provide a cured product having excellent heat resistance, water resistance, and mechanical strength.
[0002]
[Prior art]
Epoxy resins are generally cured with various curing agents, resulting in cured products with excellent mechanical properties, water 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, epoxy resins most industrially used include liquid and solid bisphenol A type epoxy resins obtained by reacting bisphenol A with epichlorohydrin. In addition, a flame retardant solid epoxy resin obtained by reacting tetrabromobisphenol A with a liquid bisphenol A type epoxy resin is industrially used as a general-purpose epoxy resin.
[0003]
[Problems to be solved by the invention]
However, the general-purpose epoxy resin as described above has a drawback that, as the molecular weight increases, the toughness of a cured product obtained by curing it increases, but the heat resistance decreases. In addition, a cured product obtained by mixing a polyfunctional epoxy resin such as a cresol novolac epoxy resin to compensate for a decrease in heat resistance has a drawback that although the heat resistance increases, the toughness decreases and the water absorption increases. . On the other hand, with recent remarkable developments in the electronics industry, the heat resistance, water resistance and mechanical strength (for example, toughness) required for the electrical insulating materials used in these are becoming increasingly severe and excellent in these characteristics. The emergence of new epoxy resins is awaited. Moreover, as an epoxy resin satisfying these characteristics, an epoxy resin having a biphenyl skeleton is described in JP-A-5-117350, but the epoxy resin specifically disclosed therein is excellent in water resistance and mechanical strength. However, since the number of functional groups is 2, it cannot be said that the heat resistance is sufficient.
[0004]
[Means for Solving the Problems]
In light of these circumstances, the present inventors have intensively studied for an epoxy resin that gives a cured product having excellent heat resistance, water resistance and mechanical strength. As a result, an epoxy resin having a specific molecular structure is excellent in the cured product. The present invention has been completed by finding that it imparts high heat resistance, water resistance and mechanical strength.
[0005]
That is, the present invention relates to (1) formula (1)
[0006]
[Chemical 2]

[0007]
(In the formula, n represents an average value and takes a value of 0 to 10. P and R represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group, and each P and R is They may be the same or different from each other, G represents a glycidyl group.
Epoxy resin represented by
[0008]
(2) An epoxy resin composition and a curing agent as described in (1) above, and an epoxy resin composition containing a curing accelerator if necessary,
(3) Hardened | cured material formed by hardening | curing the epoxy resin composition of said (2),
Is to provide.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
The compound represented by the formula (1) is, for example, the formula (2)
[0010]
[Chemical 3]

[0011]
(In the formula, n, P and R have the same meaning as in formula (1).)
[0012]
It can obtain by performing reaction of the compound represented by and epihalohydrin in presence of an alkali metal hydroxide.
[0013]
The compound represented by the formula (2) is, for example, the formula (3)
[0014]
[Formula 4]

[0015]
(Wherein X represents a halogen atom, a hydroxyl group or a lower alkoxy group. R represents the same meaning as in formula (1)) and a phenol compound in the presence of an acid catalyst. Can be obtained.
[0016]
In X of the formula (3), a halogen atom is a chlorine atom, a bromine atom, etc., a lower alkyl group is a methyl group, an ethyl group, a t-butyl group, etc., and a lower alkoxy group is a methoxy group, an ethoxy group, etc. It is mentioned as a preferable group.
[0017]
Here, phenols include aromatic compounds having one phenolic hydroxyl group in one molecule, and specific examples that can be used include phenol, cresol, ethylphenol, n-propylphenol, isobutylphenol, t-butylphenol. Various o-, m-, and p-isomers of alkylphenols such as octylphenol, nonylphenol, xylenol, methylbutylphenol, and di-t-butylphenol, or various o-, m- of vinylphenol, allylphenol, propenylphenol, and ethynylphenol , P-isomers, or cycloalkylphenols such as cyclopentylphenol, cyclohexylphenol, and cyclohexylresole, or substituted phenols such as phenylphenol. These phenols may be used alone or in combination of two or more.
[0018]
When performing the said condensation reaction, the usage-amount of phenols becomes like this. Preferably it is 0.5-20 mol with respect to 1 mol of compounds represented by Formula (3), Most preferably, it is 2-15 mol.
[0019]
In the above condensation reaction, an acid catalyst is preferably used. Various acid catalysts can be used, but inorganic or organic acids such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, oxalic acid, boron trifluoride, anhydrous chloride. Lewis acids such as aluminum and zinc chloride are preferable, and p-toluenesulfonic acid, sulfuric acid, and hydrochloric acid are particularly preferable. Although the usage-amount of these acid catalysts is not specifically limited, It is preferable to use 0.1 to 30 weight% of the compound represented by Formula (3).
[0020]
The condensation reaction can be performed in the absence of a solvent or in the presence of an organic solvent. Specific examples in the case of using an organic solvent include toluene, xylene, methyl isobutyl ketone and the like. The amount of the organic solvent used is preferably 50 to 300% by weight, particularly preferably 100 to 250% by weight, based on the total weight of the charged raw materials. The reaction temperature is preferably in the range of 40 to 180 ° C., and the reaction time is preferably 1 to 8 hours.
[0021]
After completion of the reaction, washing with water is carried out until the pH value of the washing liquid becomes 3 to 7, preferably 5 to 7. In this case, alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkaline earth metal hydroxides such as calcium hydroxide and magnesium hydroxide, ammonia, sodium dihydrogen phosphate, diethylenetriamine, and triethylenetetramine as necessary Further, various basic substances such as organic amines such as aniline and phenylenediamine may be used as a neutralizing agent. What is necessary is just to perform a washing process according to a conventional method. For example, water in which the neutralizing agent is dissolved is added to the reaction mixture, and the liquid separation extraction operation is repeated.
[0022]
After washing with water, unreacted dihydroxybenzenes and the solvent are distilled off under heating under reduced pressure to concentrate the product, whereby the compound represented by the formula (2) can be obtained.
[0023]
As a method for obtaining the epoxy resin of the present invention from the compound represented by the formula (2), a known method can be adopted. For example, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is added in advance to a mixture of the compound represented by the formula (2) obtained above and an epihalohydrin such as excess epichlorohydrin or epibromohydrin, Or the epoxy resin of this invention can be obtained by making it react at the temperature of 20-120 degreeC for 1 to 10 hours, adding.
[0024]
In the reaction for obtaining the epoxy resin of 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 under reduced pressure. Alternatively, water and epihalohydrin may be continuously distilled off under normal pressure, followed by liquid separation, removal of water, and epihalohydrin being continuously returned to the reaction system.
[0025]
Further, a quaternary ammonium salt such as tetramethylammonium chloride, tetramethylammonium bromide, trimethylbenzylammonium chloride or the like is added as a catalyst to a dissolved mixture of the compound represented by the formula (2) and epihalohydrin, and the mixture is added at 1 to 50 to Hydrogen halide solid or aqueous solution is added to the halohydrin etherified compound of the formula (2) obtained by reacting for ~ 5 hours, and reacted at a temperature of 20 to 120 ° C. for 1 to 10 hours to dehydrohalogenate A method of (ring closure) may be used.
[0026]
Usually, the amount of epihalohydrin used in these reactions is usually 1 to 20 mol, preferably 2 to 10 mol, relative to 1 equivalent of the hydroxyl group of the compound represented by formula (2). The usage-amount of an alkali metal hydroxide is 0.8-15 mol with respect to 1 equivalent of hydroxyl groups of a compound represented by Formula (2), Preferably it is 0.9-11 mol. Moreover, the usage-amount of a quaternary ammonium salt is 1-10g normally with respect to 1 equivalent of hydroxyl groups of the compound of Formula (2), Preferably it is 2-8g. Furthermore, in order to make the reaction proceed smoothly, it is preferable to carry out the reaction by adding an aprotic polar solvent such as dimethyl sulfone or dimethyl sulfoxide in addition to alcohols such as methanol and ethanol.
[0027]
When alcohols are used, the amount used is 2 to 20% by weight, preferably 4 to 15% by weight, based on the amount of epihalohydrin. Moreover, when using an aprotic polar solvent, it is 5 to 100 weight% with respect to the quantity of epihalohydrin, Preferably it is 10 to 90 weight%.
[0028]
After the epoxidation reaction product is washed with water or without washing with water, epihalohydrin, added solvent, and the like are removed at 110 to 250 ° C. under a pressure of 10 mmHg or less under reduced pressure. Further, in order to make an epoxy resin with less hydrolyzable halogen, the obtained epoxy resin is dissolved in a solvent such as toluene or methyl isobutyl ketone, and an aqueous solution of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is prepared. In addition, a further reaction can be performed to ensure ring closure. In this case, the amount of the alkali metal hydroxide used is preferably 0.01 to 0.3 mol, particularly preferably 0.05 to 1 equivalent to 1 equivalent of the hydroxyl group of the compound represented by formula (2) used for epoxidation. 0.2 mole. The reaction temperature is 50 to 120 ° C., and the reaction time is usually 0.5 to 2 hours.
[0029]
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.
[0030]
The epoxy resin composition of the present invention can be obtained by uniformly mixing the epoxy resin of the present invention, a curing agent, and a curing accelerator if necessary. In the epoxy resin composition of the present invention, an epoxy resin other than the epoxy resin of the present invention can be used in combination as the epoxy resin. When another epoxy resin is used in combination, the proportion of the epoxy resin of the present invention in the total epoxy resin is preferably 20% by weight or more.
In the epoxy resin composition of the present invention, an amine compound, an acid anhydride compound, an amide compound, a phenol compound, or the like can be used as the curing agent. Specific examples of the curing agent that can be used include diaminodiphenylmethane, diethylenetriamine, triethylenetetramine, diaminodiphenylsulfone, isophoronediamine, dicyandiamide, a polyamide resin synthesized from linolenic acid and ethylenediamine, phthalic anhydride, triethylene anhydride. Merit acid, pyromellitic anhydride, maleic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, phenol novolac, and modified products thereof, Examples include imidazole, BF ₃ -amine complex, and guanidine derivatives. Moreover, the compound represented by Formula (2) used as a raw material of the epoxy resin of this invention can also be used as a hardening | curing agent. These curing agents may be used alone or in combination of two or more.
[0031]
The amount of these curing agents used is preferably 0.7 to 1.2 equivalents relative to 1 equivalent of the epoxy group of the epoxy resin. When less than 0.7 equivalent or more than 1.2 equivalent with respect to 1 equivalent of epoxy group, curing may be incomplete and good cured properties may not be obtained.
[0032]
Moreover, when using the said hardening | curing agent, a hardening accelerator may be used together. Specific examples of the curing accelerator that can be used include imidazoles such as 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2- (dimethylaminomethyl) phenol, 1,8-diaza- And tertiary amines such as bicyclo (5,4,0) undecene-7, phosphines such as triphenylphosphine, and metal compounds such as tin octylate. The curing accelerator is used as necessary in an amount of 0.1 to 5.0 parts by weight based on 100 parts by weight of the epoxy resin. Furthermore, various compounding agents, such as fillers, such as a silica, an alumina, and a talc, a silane coupling agent, a mold release agent, and a pigment, can be added to the epoxy resin composition of this invention as needed.
[0033]
The epoxy resin composition of this invention 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.
For example, the epoxy resin of the present invention is thoroughly mixed with the curing agent, filler and other additives as necessary using an extruder, kneader, roll or the like until uniform. A cured product can be obtained by obtaining a resin composition, molding the epoxy resin composition after casting using a casting or transfer molding machine, and further heating at 80 to 200 ° C. for 2 to 10 hours. .
[0034]
In addition, the epoxy resin composition of the present invention is dissolved in a solvent such as toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, etc., and is applied to a substrate such as glass fiber, carbon fiber, polyester fiber, polyamide fiber, alumina fiber, paper, etc. A prepreg obtained by impregnation and drying by heating can be subjected to hot press molding to obtain a cured product.
[0035]
The dilution solvent used here is usually 10 to 70% by weight, preferably 15 to 65% by weight in the mixture of the epoxy resin composition of the present invention and the dilution solvent.
[0036]
Since the cured product thus obtained is excellent in heat resistance, water resistance and mechanical strength, it can be used in a wide range of fields requiring heat resistance and water resistance. Specifically, it is useful as any electrical / electronic material such as a sealing material, a laminate, and an insulating material. It can also be used in fields such as molding materials, adhesives and paints.
[0037]
【Example】
Next, the present invention will be described more specifically with reference to examples and comparative examples. In the following, parts means parts by weight unless otherwise specified.
[0038]
Example 1
In a flask equipped with a thermometer, dropping funnel, condenser, and stirrer, the following formula (4)
[0039]
[Chemical formula 5]

[0040]
242 parts of a compound represented by the above and 282 parts of phenol were charged and stirred at room temperature while blowing nitrogen. 2.8 parts of p-toluenesulfonic acid (monohydrate) was slowly added so that the liquid temperature did not exceed 50 ° C. while paying attention to heat generation. Then, it heated to 110 degreeC in the oil bath, and was made to react for 2 hours. After completion of the reaction, 1000 ml of methyl isobutyl ketone was further added, transferred to a separatory funnel and washed with water. After washing with water until the washing water shows neutrality, the solvent and unreacted substances were removed from the organic layer under heating and reduced pressure to obtain 299 parts of a resinous compound having a softening point of 108 ° C. This compound was analyzed by GPC analysis and mass spectrum (FAB-MS) analysis using tetrahydrofuran as a solvent. As a result, the compound was represented by the following formula (5).
[0041]
[Chemical 6]

[0042]
It was confirmed that it is a compound represented by. The hydroxyl equivalent calculated from the results of GPC analysis was 228 g / eq. The average value of n was 2.1.
[0043]
Subsequently, 228 parts of the compound obtained by the above reaction, 370 parts of epichlorohydrin, and 92.5 parts of dimethyl sulfoxide were charged and dissolved in a flask equipped with a thermometer, a condenser, and a stirrer while performing nitrogen gas purge. The mixture was further heated to 50 ° C., and 40.4 parts of flaky sodium hydroxide (pure 99%) were added in portions over 90 minutes, and then reacted at 60 ° C. for 2 hours and at 70 ° C. for 1 hour. After completion of the reaction, dimethyl sulfoxide and epichlorohydrin were distilled off at 130 ° C. under reduced pressure by heating, and 568 parts of methyl isobutyl ketone was added to the residue and dissolved.
[0044]
Further, this methyl isobutyl ketone solution was heated to 70 ° C., 10 parts of a 30% by weight aqueous sodium hydroxide solution was added and reacted for 1 hour, followed by washing with water three times to neutralize the pH. Further, the aqueous layer was separated and removed, and methyl isobutyl ketone was distilled off from the oil layer using a rotary evaporator under heating and reduced pressure.
[0045]
[Chemical 7]

[0046]
(In the formula, G represents a glycidyl group, and the average value of n is 2.1.)
267 parts of the epoxy resin (A) of this invention represented by these was obtained. The resulting epoxy resin had a softening point of 85.3 ° C. and an epoxy equivalent of 295 g / eq.
[0047]
Example 2
A reaction was carried out in the same manner as in Example 1 except that 432 parts of o-cresol was used instead of phenol to obtain 337 parts of a resinous compound having a softening point of 101.5 ° C. This compound was analyzed by GPC analysis and mass spectrum (FAB-MS) analysis using tetrahydrofuran as a solvent. As a result, the compound was represented by the following formula (7).
[0048]
[Chemical 8]

[0049]
It was confirmed that it is a compound represented by. The hydroxyl equivalent calculated from the results of GPC analysis was 229 g / eq. The average value of n was 1.1. Next, an epoxidation reaction was performed in the same manner as in Example 1 except that 229 parts of the compound represented by the formula (7) were used.
[0050]
[Chemical 9]

[0051]
(In the formula, G represents a glycidyl group, and the average value of n is 1.1.)
273 parts of epoxy resin (B) of this invention represented by these were obtained. The resulting epoxy resin had a softening point of 82.2 ° C. and an epoxy equivalent of 293 g / eq.
[0052]
Comparative Example 1
According to Example 1 of JP-A-5-117350, the following formula (9)
[0053]
[Chemical Formula 10]

[0054]
The compound shown by these was obtained.
[0055]
Subsequently, the epoxy resin (C) was obtained according to Example 2 of the publication using the compound of the formula (9).
[0056]
Examples 3-4, Comparative Example 2
Epoxy resins (A) and (B) of the present invention, the comparative epoxy resin (C), a phenol novolak (hydroxyl equivalent: 106 g / eq, softening point: 80.2 ° C.) as a curing agent, and triphenylphosphine as a curing accelerator (TPP), blended with the composition shown in the composition column of Table 1, kneaded with a roll at 70 ° C. for 15 minutes, transfer molded at 150 ° C. and a molding pressure of 50 kg / cm ² for 180 seconds, Thereafter, it was cured at 160 ° C. for 2 hours and further at 180 ° C. for 8 hours to prepare a test piece, and the glass transition point and water absorption were measured. The results are shown in Table 1. In addition, the measurement conditions of a glass transition point, a water absorption rate, and bending strength are as follows. Moreover, the numerical value of the column of the composition of a compound in a table | surface shows a weight part.
[0057]
Glass transition point thermomechanical measurement device (TMA): TM-7000, manufactured by Vacuum Riko Co., Ltd.
Temperature increase rate: 2 ° C / min
Water absorption

Weight increase rate after boiling for 24 hours in 100 ° C water (%)
Bending strength Measured according to JIS K-6911.
[Table 1]

[0059]
From Table 1, the cured product of the epoxy resin of the present invention showed a high glass transition point, a low water absorption, and a high mechanical strength as compared with a cured product of an epoxy resin having a known biphenyl skeleton.
[0060]
【The invention's effect】
The epoxy resin of the present invention can give a cured product having excellent heat resistance, water resistance and mechanical strength, and can be used in a wide range of applications such as molding materials, casting materials, laminate materials, paints, adhesives, and resists. Very useful for.

Claims (3)

Formula (1)

(In the formula, n represents an average value and takes a value of 1.1 to 2.1. P and R each represents a hydrogen atom, a halogen atom, an alkyl group having 1 to 8 carbon atoms, or an aryl group. P and R may be the same or different, and G represents a glycidyl group. An epoxy resin composition comprising the epoxy resin according to claim 1 and a curing agent, and optionally a curing accelerator. A cured product obtained by curing the epoxy resin composition according to claim 2.