JP4399764B2 - Epoxy resin having no silane-modified unsaturated bond, and semi-cured product and cured product obtained from the resin-containing composition - Google Patents

Description

【００１９】
（式中、ｍは０以上の整数を表す）で表される化合物であり、市販品としては、東都化成（株）製の「ＳＴ−３０００」、「ＳＴ−４０００Ｄ」、「ＳＴ−４１００Ｄ」、ジャパンエポキシレジン（株）製の「ＹＸ８０００」、「ＹＸ８０３４」等が挙げられる。
【００２０】
なお、不飽和結合を有さないエポキシ樹脂が水酸基を有さないものを一部含む場合には、水酸基を有さないエポキシ樹脂はメトキシシラン部分縮合物（２）とは反応しないため、未反応のままメトキシ基含有シラン変性エポキシ樹脂（Ａ）中に存在することとなる。水酸基を有さないエポキシ樹脂は、エポキシ樹脂−シリカハイブリッド半硬化膜形成時に、柔軟性および密着性を付与することができる。そのため、エポキシ樹脂（１）１分子中に含まれる水酸基の平均個数が、０．３を超えて５未満となるようにすることが好ましい。１分子中に含まれる水酸基の平均個数が０．３個以下であると、シリカ成分との間の結合点が少ないため、シリカ成分を多くした場合には硬化したエポキシ樹脂中にシリカが旨く分散できず、シリカとエポキシ樹脂が相分離した白濁した硬化物となる傾向があり、また、最終的に得られる硬化膜の耐熱性が不十分となる傾向があるため好ましくない。一方、１分子中に含まれる水酸基の平均が５以上になると、多官能のメトキシシラン部分縮合物（２）との反応によってゲル化する傾向にあるので好ましくない。なお、メトキシ基含有シラン変性エポキシ樹脂（Ａ）中に当該分子が多く含まれる場合、最終的に得られる硬化膜の耐熱性が不十分となる場合がある。
【００２１】
本発明に用いるメトキシシラン部分縮合物（２）としては、一般的にゾル−ゲル法に用いられているメトキシシランを部分的に加水分解、縮合したオリゴマー、例えば、一般式：Ｒ_ｐＳｉ（ＯＣＨ₃）_４−ｐ（式中、ｐは０または１を示し、Ｒは炭素数６以下の低級アルキル基またはフェニル基を示す。）で表される化合物の部分縮合物等を例示できる。なお、ｐが２〜４である場合は、３次元架橋が起こらなくなるため、最終的に得られる硬化物に所望の高耐熱性を付与することが難しくなる。
【００２２】
前記メトキシシラン部分縮合物（２）の具体例としては、テトラメトキシシランの部分縮合物；メチルトリメトキシシラン、エチルトリメトキシシラン、ｎ−プロピルトリメトキシシラン、イソプロピルトリメトキシシラン、ビニルトリメトキシシラン、フェニルトリメトキシシラン等のトリメトキシシラン類の部分縮合物があげられる。これらの中でも、テトラメトキシシランの部分縮合物が、硬化物に高度の耐熱性を付与し、かつゾル−ゲル硬化速度が速いため好ましい。
【００２３】
メトキシシラン部分縮合物（２）は、上記物質の中から１種または２種以上を適宜選択すればよいが、１分子あたりのＳｉの平均個数は３〜１２であることが好ましい。Ｓｉの平均個数が３未満であると、エポキシ樹脂（１）との脱メタノール反応の際、副生メタノールと一緒に系外に流出する有毒なメトキシシラン類の量が増えるため好ましくない。また１２を超えるとエポキシ樹脂（１）との相溶性が悪化するため、目的とするメトキシ基含有シラン変性エポキシ樹脂（Ａ）は得にくくなる。
【００２４】
特に、一般式（ｂ）：
【００２５】
【化２】

【００２６】
（式中、Ｍｅはメチル基を示し、ｎの平均繰り返し単位数は３〜１２である。）で表されるテトラメトキシシランの部分縮合物、あるいは一般式（ｃ）：
【００２７】
【化３】

【００２８】
（式中、Ｍｅはメチル基を示し、ｎの平均繰り返し単位数は３〜１２である。）で表されるメチルトリメトキシシランの部分縮合物が好ましい。
【００２９】
本発明に用いられるメトキシ基含有シラン変性エポキシ樹脂（Ａ）は、エポキシ樹脂（１）およびメトキシシラン部分縮合物（２）を、溶剤の存在下または無溶剤下に脱メタノール縮合反応させることにより得られる。エポキシ樹脂（１）とメトキシシラン部分縮合物（２）の使用量は特に限定されず、エポキシ樹脂（１）の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量（当量比）は特に制限されないが、通常は０．０２〜０．６であり、好ましくは０．０５〜０．５である。当量比が０．０２未満であると未反応のメトキシシラン部分縮合物（２）が多くなりすぎるため、０．６を超える（化学量論的に等量に近づく）と脱メタノール反応の進行でゲル化しやすくなるため好ましくない。
【００３０】
エポキシ樹脂（１）の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量（当量比）が０．２以上の場合や、１分子あたりのＳｉの平均個数が７個以上のメトキシシラン部分縮合物（２）を使用原料とする場合には、エポキシ樹脂（１）の水酸基が完全に消失するまで脱メタノール縮合反応を行うと、高粘度化やゲル化を招き易い。このような場合には、脱メタノール反応を反応途中で停止させるなどの方法により、高粘度化やゲル化を防ぐ。例えば、高粘度化してきた時点で、流出するメタノールを還流して反応系からのメタノールの留去量を調整することや、反応系を冷却し反応を終了させる等の方法を採用できる。
【００３１】
なお、本発明に用いられるメトキシ基含有シラン変性エポキシ樹脂（Ａ）は、エポキシ樹脂（１）、メトキシシラン部分縮合物（２）および１分子中に１つの水酸基および１つのエポキシ基を有するエポキシ化合物（３）（以下、単にエポキシ化合物（３）という）を溶剤の存在下または無溶剤下に脱メタノール縮合反応して得られるものであってもよい。エポキシ化合物（３）を用いることにより、特に、水酸基を有さないエポキシ樹脂が多く存在するエポキシ樹脂（１）を使用した場合であっても、得られるエポキシ樹脂−シリカハイブリッド硬化物の耐熱性を向上させることができる。
【００３２】
本発明に用いるエポキシ化合物（３）とは、複数のエポキシ基を有するエポキシ樹脂とは異なり、エポキシ基を一つだけ有する化合物であれば特に制限されないが、分子量が小さいものほどエポキシ樹脂（１）やメトキシシラン部分縮合物（２）に対する相溶性がよく、耐熱性付与効果が高いことから、炭素数が１５以下のものが好適である。具体例としては、例えば、エピクロロヒドリンと、水、２価アルコール類とを反応させて得られる分子末端に１つの水酸基を有するモノグリシジルエーテル類；エピクロロヒドリンとアミノモノアルコールとを反応させて得られる分子末端に１つの水酸基を有するエポキシ化合物；分子中に１つの水酸基を有する脂環式炭化水素モノエポキシド（例えば、エポキシ化テトラヒドロベンジルアルコール）などが例示できる。これらのエポキシ化合物の中でも、グリシドールが耐熱性付与効果の点で最も優れており、またメトキシシラン部分縮合物（２）との反応性も高いため最適である。
【００３３】
なお、エポキシ化合物（３）を用いる場合のエポキシ化合物（３）の使用量は特に限定されず、エポキシ樹脂（１）中の水酸基を有さない分子の含有量に応じて適宜に決定すればよいが、得られるエポキシ樹脂−シリカハイブリッド硬化物の耐熱性の観点から、１分子中に含まれる水酸基が２．０個以下の不飽和結合を有さないエポキシ樹脂（１）を使用する場合には、エポキシ化合物（３）の重量／エポキシ樹脂（１）の重量＝０．０３程度以上とし、１分子中に含まれる水酸基が１．０個以下の場合には０．１以上とするのが好ましい。なお、環境の点から、メトキシ基含有シラン変性エポキシ樹脂（Ａ）中のエポキシ化合物（３）残存量を極力少なくすることが好ましいが、上記重量比が０．３を超える場合には、未反応のエポキシ化合物（３）を低減させるためにメトキシ基含有シラン変性エポキシ樹脂（Ａ）の製造時間が長くなり、製造効率が低下する。
【００３４】
メトキシ基含有シラン変性エポキシ樹脂（Ａ）の製造を溶剤の存在下で行う場合に用いられる反応溶剤としては、エポキシ基と反応せず、沸点が上記脱メタノールの反応温度以上で、エポキシ樹脂（１）およびメトキシシラン部分縮合物（２）を溶解するものであれば、従来公知の溶剤を使用することができる。このような有機溶剤としては、メチルエチルケトン、メチルイソブチルケトン、トルエン、キシレン、テトラヒドロフラン、ジメチルジグリコール、ジメチルトリグリコール、ジメチルホルムアミド、ジメチルアセトアミド、ジメチルスルホキシド、Ｎ−メチルピロリドン等が例示できる。これらの中でも、半硬化状態での加工が必要な用途には、メチルエチルケトン、トルエンのような沸点が１２０℃未満で、乾燥が容易な有機溶剤が好ましい。なお、当該無溶剤用途に適用する場合には、溶剤存在下で製造されたメトキシ基含有シラン変性エポキシ樹脂（Ａ）の有機溶剤溶液を減圧して脱溶剤してもよい。
【００３５】
また、エポキシ樹脂（１）とメトキシシラン部分縮合物（２）との相溶性が高い場合、無溶剤下で反応を行うこともできる。無溶剤下で製造されるメトキシ基含有シラン変性エポキシ樹脂（Ａ）は、無溶剤で使用される用途、例えば接着剤、成形加工品、シーリング材などの材料として、そのまま使用できる利点がある。また、このような無溶剤メトキシ基含有シラン変性エポキシ樹脂（Ａ）は、溶剤存在下で製造された該エポキシ樹脂（Ａ）の有機溶剤溶液を減圧して脱溶剤しても得ることができる。
【００３６】
脱メタノール縮合反応に際しては、反応促進のために従来公知の触媒の内、エポキシ環を開環しないものを使用することができる。該触媒としては、例えば、リチウム、ナトリウム、カリウム、ルビジウム、セシウム、マグネシウム、カルシウム、バリウム、ストロンチウム、亜鉛、アルミニウム、チタン、コバルト、ゲルマニウム、錫、鉛、アンチモン、砒素、セリウム、硼素、カドミウム、マンガンのような金属；これら金属の酸化物、有機酸塩、ハロゲン化物、メトキシド等があげられる。これらのなかでも、特に有機錫、有機酸錫が好ましく、具体的には、ジブチル錫ジラウレート、オクチル酸錫等が有効である。
【００３７】
なお、脱メタノール縮合反応する際の、反応温度は５０〜１３０℃程度、好ましくは７０〜１３０℃であり、全反応時間は１〜２４時間程度である。この反応は、メトキシシラン部分縮合物（２）自体の重縮合反応を防止するため、実質的に無水条件下で行うのが好ましい。
【００３８】
このようにして得られたメトキシ基含有シラン変性エポキシ樹脂（Ａ）は、その分子中にメトキシシラン部分縮合物（２）に由来するメトキシ基を有している。このメトキシ基は加熱処理や水分（湿気）との反応により、ゾル−ゲル反応や脱メタノール縮合して、相互に結合したハイブリッド硬化物を形成するために必要となるため、当該メトキシ基の含有量は、通常、原料となるメトキシシラン部分縮合物（２）のメトキシ基の４０〜９５モル％程度、好ましくは５０〜９０モル％を未反応のままで保持しておくのがよい。なお、メトキシ基含有シラン変性エポキシ樹脂（Ａ）中には、メトキシシラン部分縮合物（２）が未反応のまま含有されていてもよい。未反応のメトキシシラン部分縮合物（２）は、ゾル−ゲル硬化時に加水分解、重縮合によりシリカとなり、メトキシ基含有シラン変性エポキシ樹脂（Ａ）と結合する。
【００３９】
本発明では、メトキシ基含有シラン変性エポキシ樹脂（Ａ）とエポキシ樹脂用硬化剤（Ｂ）を組み合わせてシラン変性エポキシ樹脂組成物として使用する。
【００４０】
エポキシ樹脂用硬化剤（Ｂ）としては、通常、エポキシ樹脂の硬化剤として使用されている従来公知の硬化剤が使用できるが、無色透明な硬化物が得られるため、脂環式酸無水物系硬化剤、アニオン重合型硬化剤、カチオン重合型硬化剤等を用いることが好ましい。脂環式酸無水物系硬化剤としては、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、３，６−エンドメチレンテトラヒドロ無水フタル酸、ヘキサクロルエンドメチレンテトラヒドロ無水フタル酸、メチル−３，６−エンドメチレンテトラヒドロ無水フタル酸があげられる。アニオン重合型硬化剤としてはベンジルジメチルアミン、２−（ジメチルアミノメチル）フェノール、２，４，６−トリス（ジアミノメチル）フェノール等の芳香族トリアミン類や、２-メチルイミダゾール、２−エチル−４−メチルイミダゾール、２-エチルへキシルイミダゾール、２−ウンデシルイミダゾール、１−シアノエチル−２‐メチルイミダール等のイミダゾール類があげられる。カチオン重合型硬化剤としては、芳香族ジアゾニウム塩、ジアリルヨードニウム塩、トリアリルスルホニウム塩、トリアリルスルホニウム塩等の光分解型硬化剤があげられる。
【００４１】
前記シラン変性エポキシ樹脂組成物には、硬化物の着色を防止するため、公知の酸化劣化防止剤、着色防止剤、紫外線吸収材等を用いることができる。他にも、必要に応じて、有機溶剤、充填剤、離型剤、表面処理剤、難燃剤、粘度調節剤、可塑剤、抗菌剤、防黴剤、レベリング剤、消泡剤、着色剤、安定剤、カップリング剤等を本発明の効果を損なわない範囲で配合してもよい。また、本発明のシラン変性エポキシ樹脂組成物を各種用途へ適用するにあたっては、エポキシ樹脂−シリカハイブリッド硬化物や半硬化物の柔軟性や力学強度等を調整するため、各種のエポキシ樹脂やゴム成分などを併用することもできる。当該併用しうるエポキシ樹脂としては、本発明の構成成分として記載した前記ノボラック型エポキシ樹脂；ビスフェノール類とエピクロロヒドリンを反応させて得られるビスフェノール型エポキシ樹脂；フタル酸、ダイマー酸などの多塩基酸類およびエピクロロヒドリンを反応させて得られるグリシジルエステル型エポキシ樹脂；ジアミノジフェニルメタン、イソシアヌル酸などのポリアミン類とエピクロロヒドリンを反応させて得られるグリシジルアミン型エポキシ樹脂；オレフィン結合を過酢酸などの過酸で酸化して得られる線状脂肪族エポキシ樹脂および脂環式エポキシ樹脂などがあげられる。またゴム成分としてはポリイソブテン、ポリブチレン、ポリブタジエン、ブタジエン−アクリロニトリルゴム、クロロプレンゴム、シリコンゴム等が挙げられる。
【００４２】
前記シラン変性エポキシ樹脂組成物からエポキシ樹脂−シリカハイブリッド硬化物を得るためには、メトキシ基含有シラン変性エポキシ樹脂（Ａ）のメトキシシリル部位のゾル−ゲル硬化およびエポキシ基のエポキシ硬化を行わねばならない。この際、エポキシ硬化に先立ってゾル−ゲル硬化を行わなければならない。エポキシ硬化をゾル−ゲル硬化に先行させると、エポキシ樹脂−シリカハイブリッド硬化物はゾル−ゲル硬化に起因するメタノールの発生によって、発泡やクラックを生じる。
【００４３】
ゾル−ゲル硬化をエポキシ硬化に先行させるためには、ゾル−ゲル硬化を促進させるための触媒を当該樹脂組成物中に配合することが好ましい。ゾル−ゲル硬化触媒としては、酸または塩基性触媒、金属系触媒など従来公知のものをあげることができるが、特にオクチル酸錫やジブチル錫ジラウレートが高活性で、しかも溶解性に優れており好ましい。前記触媒の使用量は使用する触媒の活性、目的とする硬化物の膜厚、エポキシ樹脂用硬化剤（Ｂ）の種類により適宜決めることができる。通常、使用するメトキシ基含有シラン変性エポキシ樹脂（Ａ）のメトキシ基に対し、モル比率で、触媒能力の高いパラトルエンスルホン酸やオクチル酸錫などで０．０１〜５モル％程度、触媒能力の低いギ酸、酢酸などで０．１〜５０モル％程度使用される
【００４４】
シラン変性エポキシ樹脂組成物から直接ハイブリッド硬化物を得るには、用いた硬化剤（Ｂ）の種類に応じた方法によって硬化を行う必要がある。これは、メトキシシリル部位のゾル−ゲル硬化反応によりメタノールが発生するため、メトキシ基含有シラン変性エポキシ樹脂（Ａ）中のエポキシ基とエポキシ樹脂用硬化剤（Ｂ）とのエポキシ基の開環・架橋反応による硬化が進行した後に、当該メタノールが発生した場合には、発泡やクラックが生じるため、触媒を適宜に選択することによってゾル−ゲル硬化反応速度を調整する必要がある。当該硬化剤（Ｂ）として脂環式酸無水物系硬化剤を用いる場合には、当該硬化剤（Ｂ）以外にゾル−ゲル硬化触媒を０．１％以上併用して、１５０〜２００℃で硬化させるのが好ましい。
【００４５】
また、シラン変性エポキシ樹脂組成物を、エポキシ硬化を進行させることなくゾル−ゲル硬化のみを進行させることで、エポキシ樹脂−シリカ半硬化物を得ることができる。該半硬化物はエポキシ基が未硬化であるため熱可塑性であり、熱成形や熱圧着を行うことにより、任意に加工を行うことができる。
【００４６】
このようなエポキシ樹脂−シリカ半硬化物を得るためには、エポキシ基の反応率を３０％以下、好ましくは２０％以下に留めたまま、メトキシシリル部位を７０％以上、好ましくは９０％以上生成させればよい。具体的には、前記ゾル−ゲル触媒を添加したシラン変性エポキシ樹脂組成物を、好ましくは５０〜１２０℃で加熱することにより、ゾル−ゲル硬化反応のみを進行させればよい。エポキシ硬化反応が３０％を超えて進行すると、エポキシ硬化のため熱可塑性が失われ、加工を行うことができない。メトキシシリル部位の反応率が７０％未満であると、半硬化物作製に引き続く完全硬化反応において硬化収縮やクラック、発泡が生じる可能性がある。
【００４７】
さらにこのような半硬化物は、用いた硬化剤（Ｂ）の種類に応じた方法によって完全硬化させて、エポキシ樹脂−シリカハイブリッド硬化物へと導かれる。また、シラン変性エポキシ樹脂組成物から直接エポキシ樹脂−シリカハイブリッド硬化物を得ることも可能である。硬化剤（Ｂ）やゾル−ゲル触媒を適宜に選択することによってゾル−ゲル硬化反応速度を調整し、エポキシ硬化に先立ってゾル−ゲル硬化が進行するようにすればよい。
【００４８】
得られたエポキシ樹脂−シリカハイブリッド硬化物は高度な耐熱性、絶縁性、密着性とともに無色透明性を有しているため、特に発光素子、受光素子、光電変換素子、光伝送関連部品用バインダー、液晶パネルやカラーフィルター、プラスチックフィルムの保護コート剤、偏光板、プラスチックLANケーブル、光導路基板、ピックアップレンズ、液晶セル用プラスチック基板、プリズム、液晶画面のコーティング剤等の光学部品の構成材料として有用である。
【００４９】
上記の用途の中でも基材の保護を目的とする保護コート剤では、エポキシ−シリカハイブリッド硬化物中にシリカを１５〜６０％含み、鉛筆硬度４Ｈ〜８Ｈのエポキシ樹脂−シリカハイブリッドを作る様に調製するのが好ましい。また偏光板、プラスチックLANケーブル、光導路基板、ピックアップレンズ、プラスチック基板、プリズム、液晶画面のコーティング剤等の光学用途では、特に光散乱を防ぐ必要性からエポキシ−シリカハイブリッドの屈折率を１．５未満となるように調整するのが好ましい。プラスチック基板や光導波路基板などはんだのリフローが必要な用途では、２３０℃での弾性率が１×１０^８Ｐａ以上になり、５％熱分解温度が２８０℃以上になるように調製するのが好ましい。
【００５０】
【発明の効果】
本発明によれば、高度な耐熱性、絶縁性、密着性と無色透明性を有するエポキシ樹脂−シリカハイブリッド硬化物を提供することができる。
【００５１】
【実施例】
以下、実施例および比較例をあげて本発明を具体的に説明する。なお、各例中、％は特記しない限り重量基準である。
【００５２】
実施例１（メトキシ基含有シラン変性エポキシ樹脂（Ａ）の製造）
攪拌機、冷却管、温度計、窒素吹き込み口を備えた反応装置に、水添ビスフェノールＡ型エポキシ樹脂（東都化成（株）製、商品名「サントートＳＴ−４０００Ｄ」、エポキシ当量７４０ｇ／ｅｑ、水酸基当量３８０ｇ／ｅｑ）８００ｇをジグライム８００ｇに１２０℃で溶解させ、ポリ（テトラメトキシシラン）（多摩化学（株）製、商品名「Ｍシリケート５１」、１分子あたりのＳｉの平均個数４．０）７２６ｇと触媒としてジブチル錫ジラウレート０．７ｇを加え、１２０℃で１２時間脱メタノール反応させることによって、メトキシ基含有シラン変性エポキシ樹脂（以下、樹脂（Ａ−１）という）を得た。
なお、エポキシ樹脂（１）の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量＝０．１３７であった。樹脂（Ａ−１）のエポキシ当量は２１１０ｇ／ｅｑであった。
【００５３】
実施例２
実施例１と同様の反応装置に、水添ビスフェノールＡ型エポキシ樹脂（東都化成（株）製、商品名「サントートＳＴ−４０００Ｄ」、エポキシ当量７４０ｇ／ｅｑ、水酸基当量３８０ｇ／ｅｑ）８００ｇをジグライム７２０ｇに１２０℃で溶解させ、ポリ（テトラメトキシシラン）（多摩化学（株）製、商品名「Ｍシリケート５１」、１分子あたりのＳｉの平均個数４．０）９０８ｇと触媒としてジブチル錫ジラウレート０．７ｇを加え、１２０℃で１２時間脱メタノール反応させることによって、メトキシ基含有シラン変性エポキシ樹脂（以下、樹脂（Ａ−２）という）を得た。
なお、仕込み時のエポキシ樹脂（１）の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量＝０．１であった。樹脂（Ａ−２）のエポキシ当量は２２００ｇ／ｅｑであった。
【００５４】
実施例３
攪拌機、分水器、温度計、窒素吹き込み口を備えた反応装置に、水添ビスフェノールＡ型エポキシ樹脂（東都化成（株）製、商品名「サントートＳＴ−４０００Ｄ」、エポキシ当量７４０ｇ／ｅｑ、水酸基当量３８０ｇ／ｅｑ）４００ｇ、液状の水添ビスフェノールＡ型エポキシ樹脂（東都化成（株）製、商品名「ＹＸ８０００」、エポキシ当量２０５ｇ／ｅｑ、水酸基を有さない）１０４２ｇ、グリシドール１１４ｇを１２０℃で溶解させ、ポリ（テトラメトキシシラン）（多摩化学（株）製、商品名「Ｍシリケート５１」、１分子あたりのＳｉの平均個数４．０）７３４ｇと触媒としてジブチル錫ジラウレート２．０ｇを加え、１００℃で８時間、生成するメタノールを分水器によって流出させながら脱メタノール反応させることによって、メトキシ基含有シラン変性エポキシ樹脂（以下、樹脂（Ａ−３）という）を得た。
なお、仕込み時のエポキシ樹脂（１）の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量＝０．０６８、グリシドールの重量／不飽和結合を有さないエポキシ樹脂（１）＝０．０７９であった。樹脂（Ａ−３）のエポキシ当量は２９０ｇ／ｅｑであった。
【００５５】
実施例４（メトキシ基含有シラン変性エポキシ樹脂（Ａ）の製造）
実施例１と同様の反応装置に、水添ビスフェノールＡ型エポキシ樹脂（東都化成（株）製、商品名「サントートＳＴ−４０００Ｄ」、エポキシ当量７４０ｇ／ｅｑ、水酸基当量３８０ｇ／ｅｑ）８００ｇをジグライム９２０ｇに１２０℃で溶解させ、ポリ（メチルトリメトキシシラン）（多摩化学（株）製、商品名「ＭＴＭＳ−Ａ」、１分子あたりのＳｉの平均個数３．２）４３０ｇと触媒としてジブチル錫ジラウレート０．６ｇを加え、１２０℃で１０時間脱メタノール反応させることによってメトキシ基含有シラン変性エポキシ樹脂（以下、樹脂（Ａ−４）という）を得た。
なお、仕込み時の不飽和結合を有さないエポキシ樹脂（１）の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量＝０．２８６であった。樹脂（Ａ−４）のエポキシ当量は１９５０ｇ／ｅｑであった。
【００５６】
比較例１
サントートＳＴ−４０００Ｄ ８００ｇにジグライム８００ｇを加えて溶解させた。以下、該樹脂組成物を樹脂（ａ−１）という。
【００５７】
比較例２
サントートＳＴ−４０００Ｄ ８００ｇ、ＭＳ−５１ ７２６ｇおよびジグライム８００ｇを混合することにより、エポキシ樹脂組成物を得た。以下、該樹脂組成物を樹脂（ａ−２）という。
【００５８】
比較例３
実施例１と同様の反応装置に、ビスフェノールＡ型エポキシ樹脂（ジャパンエポキシレジン（株）製、商品名「エピコート１００１」、エポキシ当量４７２ｇ／ｅｑ）３３６．０ｇおよびメチルエチルケトン２６８．８ｇを加え、７０℃で溶解した。さらにポリ（テトラメトキシシラン）（多摩化学（株）製、商品名「ＭＳ−５１」、１分子あたりのＳｉの平均個数４）３６０．４ｇと、触媒としてジブチル錫ジラウレート０．３ｇを加え、８０℃で６時間還流反応させた後、５０℃まで冷却し、メタノール３３．６ｇを加え、メトキシ基含有シラン変性エポキシ樹脂（以下、樹脂（ａ−３）という）を得た。ビスフェノール型エポキシ樹脂の水酸基の当量／メトキシシラン部分縮合物（２）のメトキシ基の当量＝０．１、エポキシ当量は１４００ｇ／ｅｑであった。
【００５９】
実施例５〜８および比較例４〜６（シラン変性エポキシ樹脂組成物の調製とエポキシ樹脂−シリカハイブリッド半硬化物の作製）
実施例１〜４および比較例１〜３で得られた各樹脂に、４−メチルヘキサヒドロ無水フタル酸（新日本理化（株）製、商品名「ＭＨ−７００」）をエポキシ基の当量／酸無水物基の当量が１／１となる割合で加え、オクチル酸錫（エーピーアイコーポレーション製、商品名「スタノクト」）を固形分あたり１％加え、シラン変性エポキシ樹脂組成物（Ｂ−５〜８、ｂ−４〜６）とした。
【００６０】
（エポキシ樹脂−シリカハイブリッド半硬化物の評価）
実施例５〜８および比較例４〜６で得られた各エポキシ樹脂組成物を、フッ素樹脂コーティングされた容器（縦×横×深さ＝１０ｃｍ×１０ｃｍ×１．５ｃｍ）に注ぎ、１００℃で１５分間加熱することにより、溶剤の揮発およびゾル−ゲル硬化を行い、エポキシ樹脂−シリカハイブリッド半硬化物を得た。得られた半硬化物の状態（外観、収縮、発泡、成形加工性）を以下の基準で評価した。結果を表１に示す。
【００６１】
（外観の評価）
○：透明。
△：曇りがある。
×：白化している。
【００６２】
（収縮の評価）
○：硬化物にクラック、そりがない。
△：硬化物にそりが存在する。
×：硬化物にクラックがある。
【００６３】
（発泡の評価）
○：硬化物中に気泡がない。
△：硬化物中に気泡が５つ未満存在する。
×：硬化物中に気泡が５つ以上存在する。
【００６４】
（成形加工性の評価）
○：柔軟であり、成形性に富む。
×：変形させると割れる。
【００６５】
【表１】

【００６６】
表１から明らかなように、実施例５〜８および比較例４、６では、いずれも透明で、熱成形や熱圧着可能な半硬化物が得られた。しかし比較例５で得られた半硬化物は、エポキシ樹脂とシリカの相分離によって白化しており、しかも非常に脆いものであった。比較例６で得られた半硬化物は透明であったが、変形させると割れてしまった。従って、実施例５〜８の半硬化物は、成型加工が必要な発光ダイオードの封止材、光ディスク基板、ピックアップレンズ、液晶セル用プラスチック基板、プリズムなどの構成材料として好適である。
【００６７】
実施例９〜１２および比較例７〜９（エポキシ樹脂−シリカハイブリッド硬化物の調製および評価）
実施例５〜８および比較例４〜６で得られた半硬化物をさらに１５０℃で３時間加熱することによって、エポキシ硬化させ、完全硬化物を得た。得られた完全硬化物の状態（外観、収縮、発泡）を以下の基準で評価した。結果を表２に示す。
【００６８】
（外観の評価）
○：透明。
△：曇りがある。
×：白化している。
【００６９】
（収縮の評価）
○：硬化物にクラック、そりがない。
△：硬化物にそりが存在する。
×：硬化物にクラックがある。
【００７０】
（発泡の評価）
○：硬化物中に気泡がない。
△：硬化物中に気泡が５つ未満存在する。
×：硬化物中に気泡が５つ以上存在する。
【００７１】
（着色の評価）
○：硬化物が無色透明。
△：硬化物が黄色透明。
×：硬化物が不透明。
【００７２】
【表２】

【００７３】
実施例９〜１２では、いずれも透明なエポキシ樹脂−シリカハイブリッド硬化物が得られた。比較例９で得られたエポキシ樹脂−シリカハイブリッド硬化物は透明であったが、黄色に着色した。比較例８で得られた完全硬化物にはエポキシ樹脂とシリカの相分離によってムラ、発泡、クラックがあり、非常に脆いものであった。
【００７４】
（耐熱性）
実施例９および比較例７で得られた硬化フィルムを５ｍｍ×２０ｍｍにカットし、粘弾性測定器（レオロジ社製、商品名「ＤＶＥ−Ｖ４」、測定条件：振幅０．５μｍ、振動数１０Ｈｚ、スロープ３℃／分）を用いて動的貯蔵弾性率を測定して、耐熱性を評価した。測定結果を図１に示す。
【００７５】
図１から明らかなように、実施例９では比較例７に比べ、硬化フィルムのガラス転移点は上昇しており、また、高温でも弾性率の低下が少なく、耐熱性に優れている。従って、実施例９の硬化物は、耐熱性が要求される発光ダイオードの封止材、光導波路基板の構成材料等として好適である。
【００７６】
（耐熱分解性）
実施例９および比較例７で得られた硬化物の熱重量損失を、示差熱・熱重量同時測定装置（セイコーインスツルメンス（株）製、商品名「ＴＧ／ＤＴＡ２２０」、測定条件：スロープ１０℃／分）により測定した。結果を表３に示す。
【００７７】
【表３】

【００７８】
表３から明らかなように、実施例９は比較例７に比べて１０％重量損失時の温度が十分に高く、耐熱分解性に優れているため、発光ダイオードの封止材、光導波路基板の構成材料等として好適である。
【００７９】
（密着性）
実施例９および比較例７で得られた各エポキシ樹脂組成物をバーコーターで各基材に塗布し、１００℃で１５分間加熱することによって溶剤の揮発およびゾル−ゲル硬化を行い、さらに１５０℃で３時間加熱することによって、エポキシ硬化させ、完全に硬化させて、膜厚２０μｍの硬化物を得た。
【００８０】
ＪＩＳ Ｋ−５４００の一般試験法によるゴバン目セロハンテープ剥離試験を行い、以下の基準で判定した。評価結果を表４に示す。
◎：１００／１００
○：９９〜９５／１００
△：９４〜７０／１００
×：６９〜０／１００
【００８１】
【表４】

【００８２】
表４から明らかなように、実施例９の硬化膜は比較例７のものと同様に金属やセラミック基材に対する密着性に優れており、液晶画面のコーティング剤、カラーフィルターの保護コート剤等の構成材料として好適である。
【００８３】
（耐熱黄変性）
上記の（密着性）の項目で使用したガラス板上の硬化膜をさらに２００℃で２時間加熱した後、硬化膜の外観を以下の基準で評価した。結果を表５に示す。
○：硬化物が無色透明。
△：硬化物が黄変。
×：硬化物が褐変。
【００８４】
【表５】

【００８５】
実施例９の硬化膜は比較例７のものに比べて高温環境下でも着色がなく、発光ダイオードの封止材、光導波路基盤などの光伝送関連部品の構成材料等として好適である。
【００８６】
（耐傷付き性）
上記の（耐熱黄変性）の項目で使用したガラス板上の硬化膜を用いて、ＪＩＳＫ−５４００の塗料一般試験方法による鉛筆引っかき試験を行った。結果を表６に示す。
【００８７】
【表６】

【００８８】
実施例９の硬化膜は比較例７のものに比べて耐傷つき性に優れているため、液晶画面のコーティング剤、カラーフィルターの保護コート剤等の構成材料として好適である。
【００８９】
実施例１３、１４および比較例１０（シラン変性エポキシ樹脂組成物の調製とエポキシ樹脂−シリカハイブリッド硬化物の作製）
実施例１、２および比較例１で得られた各樹脂に、光硬化触媒（光カチオン発生触媒（ローディア（株）製、商品名シリコリース ＣＡＴＡ２１１：イソプロピルアルコール溶液、有効成分１８％）を固形分あたり１％加え、オクチル酸錫（エーピーアイコーポレーション製、商品名「スタノクト」）を固形分あたり１％加え、シラン変性エポキシ樹脂組成物とした後、１００℃で１５分間加熱することによって溶剤の揮発およびゾル−ゲル硬化を行い、紫外線露光装置を用いて紫外線を照射してエポキシ硬化させた。得られた硬化物の５８９ｎｍでの屈折率を測定した。結果を表７に示す。
【００９０】
【表７】

【００９１】
表７から明らかなように、硬化物中のシリカ含有量によって屈折率をコントロールすることが可能であり、光導波路基盤などの光伝送関連部品の構成材料として好適である。
【図面の簡単な説明】
【図１】 実施例９および比較例７で得られた硬化フィルムの耐熱性の評価結果である。[0001]
BACKGROUND OF THE INVENTION
The present invention is silane modified Hydrogenated bisphenol A type epoxy resin The resin-containing composition, an epoxy resin-silica hybrid semi-cured product and an epoxy resin-silica hybrid cured product obtained from the composition. Since the epoxy resin-silica hybrid cured product obtained by the present invention is excellent in heat resistance, adhesion, electrical insulation, colorless transparency, and low birefringence, it can be used for paints, adhesives, sealing agents, printed wiring board materials, IC seals. Can be used as a fixing material, insulating sealant, etc., especially light emitting element, light receiving element, photoelectric conversion element, optical transmission related parts, liquid crystal screen coating agent, color filter protective coating agent, optical disk substrate, pickup lens, liquid crystal cell plastic It is useful as a constituent material for optical components such as substrates, prisms, liquid crystal screen coating agents, and color filter protective coating agents.
[0002]
[Prior art]
Epoxy resins are excellent in heat resistance, adhesion, water resistance, mechanical properties, electrical properties, etc., and have been used in various fields such as coating agents, adhesives, and insulating materials for electrical and electronic parts. In recent years, with the development of technology especially in the fields of electrical and electronic parts, optical parts, etc., higher heat resistance, insulation, adhesion and the like have been demanded.
[0003]
In order to improve the heat resistance of the cured product of the epoxy resin composition, for example, a method of mixing a filler such as glass fiber in addition to the epoxy resin and the curing agent has been proposed (for example, see Non-Patent Document 1). In this method, sufficient heat resistance cannot be obtained, the transparency of the obtained cured product is lost, and the adhesiveness at the interface between the filler and the epoxy resin is inferior. It was enough.
[0004]
Also, by adding a hydrolyzable alkoxysilane to the partially cured epoxy resin solution, further curing the cured product, hydrolyzing the alkoxysilane into a sol, and further polycondensing to gel. A method of improving the heat resistance of the obtained cured product using a composite of the obtained epoxy resin and silica has been proposed (Patent Document 1, etc.), but the cured product of the composite is an epoxy resin alone. Although the heat resistance is improved to some extent as compared with the cured product, there is a problem that voids (bubbles) are generated in the cured product due to water contained in the composite, water generated during curing, alcohol. Further, when the amount of alkoxysilane is increased for the purpose of further improving the heat resistance, the silica produced by the sol-gel curing reaction aggregates and the resulting cured product loses its transparency and whitens. , Requires a large amount of water to a sol of a large amount of the alkoxysilane, warpage of the resulting cured product was achieved, leading to cracks.
[0005]
Further, a composition (Patent Document 2) in which a silane-modified epoxy resin obtained by reacting an epoxy resin with a silicone compound and a phenol novolac resin as a curing agent, bisphenol A type epoxy resin, tetrabisbromobisphenol A and methoxy are combined. Compositions (Patent Document 3, Patent Document 4, etc.) in which a silane-modified epoxy resin obtained by reacting a group-containing silicone intermediate and a phenol novolak resin as a curing agent have also been proposed. These epoxy resin compositions The cured product was insufficient in heat resistance because the main constituent unit of the silicone compound or methoxy group-containing silicone intermediate was a diorganopolysiloxane unit and silica could not be produced.
[0006]
By the way, the present applicant has solved the above-mentioned problems, and the glass transition point disappears, and a bisphenol type epoxy resin or novolak type epoxy resin and a methoxysilane partial condensate, which become a high heat resistance material, are subjected to a demethanol reaction. An epoxy-silica hybrid cured product obtained by curing a methoxy group-containing silane-modified epoxy resin is proposed (Patent Document 5, Patent Document 6, etc.). The epoxy-silica hybrid cured product obtained by this method has high heat resistance, insulation and adhesion, and can be used in a wide range of applications such as paints, adhesives and sealants, especially insulation coating agents and printed wiring. It is particularly useful as a substrate material, IC sealing material, insulating sealant, etc., but since the base epoxy resin has an aromatic ring, the cured product is colored during heat curing or under heat history, and is colorless and transparent However, there is a problem that it is difficult to use as an optical material.
[0007]
By the way, an epoxy resin having no unsaturated bond typified by hydrogenated bisphenol A type epoxy resin has a cured product that is colorless and transparent and has a low birefringence. (Patent Document 7, Patent Document 8, Patent Document 9, etc.). However, the hydrogenated bisphenol A type epoxy resin has a problem in heat resistance because the stability of the cyclohexane ring is lower than that of the aromatic ring and the glass transition temperature of the resulting cured product is also low.
[0008]
In addition, since the composition which mixed hydrogenated bisphenol A type epoxy resin and alkoxysilane is proposed (patent document 10, patent document 11), since it is the same as the composite_body | complex of the epoxy resin and silica mentioned above. The disadvantages of the method remain.
[0009]
[Patent Document 1]
JP-A-8-100107
[Patent Document 2]
JP-A-3-2014466
[Patent Document 3]
JP-A-61-272243
[Patent Document 4]
JP-A-61-272244
[Patent Document 5]
Japanese Patent No. 3077695
[Patent Document 6]
JP 2003-55435 A
[Patent Document 7]
JP 2003-12896 A
[Patent Document 8]
JP 2002-69155 A
[Patent Document 9]
JP 2001-342240 A
[Patent Document 10]
Japanese National Patent Publication No. 10-509195
[Patent Document 11]
JP-T-2001-509188
[Non-Patent Document 1]
Edited by Hiroshi Kakiuchi, “New Epoxy Resin”, Shosho-do, May 10, 1985, p. 292-307
[0010]
[Problems to be solved by the invention]
The present invention is an epoxy resin having no silane-modified unsaturated bond, which can obtain an epoxy resin-silica hybrid cured product having both high heat resistance, insulation, adhesion and colorless transparency. And a semi-cured product and a cured product obtained from the resin-containing composition.
[0011]
[Means for Solving the Problems]
As a result of intensive studies to solve the above problems, the present inventors have used a methoxy group-containing silane-modified epoxy resin obtained by demethanol reaction of a specific epoxy resin and a specific methoxysilane partial condensate. In addition, by using a silane-modified epoxy resin composition comprising the methoxy group-containing silane-modified epoxy resin and a specific epoxy resin curing agent, it is found that an epoxy resin-silica hybrid cured product meeting the above-mentioned purpose can be obtained. The present invention has been completed.
[0012]
That is, the present invention Has a hydroxyl group The present invention relates to a methoxy group-containing silane-modified epoxy resin (A) obtained by subjecting a hydrogenated bisphenol A type epoxy resin (1) and a methoxysilane partial condensate (2) to a demethanol condensation reaction. The present invention also provides Has a hydroxyl group It is obtained by subjecting a hydrogenated bisphenol A type epoxy resin (1), a methoxysilane partial condensate (2), and an epoxy compound (3) having one hydroxyl group and one epoxy group in one molecule to a demethanol condensation reaction. The present invention relates to a methoxy group-containing silane-modified epoxy resin. Furthermore, the present invention relates to a silane-modified epoxy resin composition comprising a methoxy group-containing silane-modified epoxy resin (A) and an epoxy resin curing agent (B). The present invention also relates to an epoxy resin-silica hybrid semi-cured product obtained by heating the silane-modified epoxy resin composition at 50 to 120 ° C. and curing it. Furthermore, the present invention relates to an epoxy resin-silica hybrid cured product obtained by completely curing a silane-modified epoxy resin composition or semi-cured product.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
In the present invention, as a constituent component of the methoxy group-containing silane-modified epoxy resin (A), Hydrogenated bisphenol A type epoxy resin (1) Essentially used (hereinafter simply referred to as epoxy resin (1)). In the present invention, the epoxy resin (1) does not have an unsaturated bond, and a hydroxyl group for forming a silicate ester by a demethanol condensation reaction with the methoxysilane partial condensate (2). What is necessary is just to have. When it has an unsaturated bond, coloring occurs due to oxidation of the unsaturated bond, which is not preferable. In the present invention, the unsaturated bond means an aromatic ring such as a benzene ring in addition to a carbon-carbon double bond and triple bond.
[0016]
water It is possible to adjust the number of hydroxyl groups contained in one molecule by combining bisphenol A type epoxy resins having various molecular weights, and it is easily available. Is .
[0017]
The hydrogenated bisphenol A type epoxy resin has the general formula (a):
[0018]
[Chemical 1]

[0019]
(Wherein, m represents an integer of 0 or more), and commercially available products include “ST-3000”, “ST-4000D”, and “ST-4100D” manufactured by Toto Kasei Co., Ltd. “YX8000”, “YX8034”, etc., manufactured by Japan Epoxy Resins Co., Ltd.
[0020]
In addition, when the epoxy resin which does not have an unsaturated bond partially contains what does not have a hydroxyl group, since the epoxy resin which does not have a hydroxyl group does not react with a methoxysilane partial condensate (2), it is unreacted It remains in the methoxy group-containing silane-modified epoxy resin (A). An epoxy resin having no hydroxyl group can impart flexibility and adhesion when forming an epoxy resin-silica hybrid semi-cured film. Therefore, it is preferable that the average number of hydroxyl groups contained in one molecule of the epoxy resin (1) is more than 0.3 and less than 5. When the average number of hydroxyl groups contained in one molecule is 0.3 or less, the number of bonding points with the silica component is small, so when the silica component is increased, the silica is dispersed well in the cured epoxy resin. This is not preferable because it tends to be a cloudy cured product in which silica and epoxy resin are phase-separated and the heat resistance of the finally obtained cured film tends to be insufficient. On the other hand, if the average number of hydroxyl groups contained in one molecule is 5 or more, it tends to gel by reaction with the polyfunctional methoxysilane partial condensate (2), which is not preferable. In addition, when many said molecules are contained in a methoxy group containing silane modified epoxy resin (A), the heat resistance of the finally obtained cured film may become inadequate.
[0021]
As the methoxysilane partial condensate (2) used in the present invention, an oligomer obtained by partially hydrolyzing and condensing methoxysilane generally used in a sol-gel method, for example, a general formula: R _p Si (OCH _Three ) _4-p (Wherein, p represents 0 or 1, and R represents a lower alkyl group having 6 or less carbon atoms or a phenyl group). In addition, when p is 2-4, since three-dimensional crosslinking does not occur, it becomes difficult to impart desired high heat resistance to the finally obtained cured product.
[0022]
Specific examples of the methoxysilane partial condensate (2) include tetramethoxysilane partial condensate; methyltrimethoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, isopropyltrimethoxysilane, vinyltrimethoxysilane, Examples thereof include partial condensates of trimethoxysilanes such as phenyltrimethoxysilane. Among these, a partial condensate of tetramethoxysilane is preferable because it imparts high heat resistance to the cured product and has a high sol-gel curing rate.
[0023]
The methoxysilane partial condensate (2) may be appropriately selected from one or more of the above substances, but the average number of Si per molecule is preferably 3-12. If the average number of Si is less than 3, the amount of toxic methoxysilanes flowing out of the system together with by-product methanol during the demethanol reaction with the epoxy resin (1) is not preferable. Moreover, since compatibility with an epoxy resin (1) will deteriorate when it exceeds 12, the target methoxy group containing silane modified epoxy resin (A) becomes difficult to obtain.
[0024]
In particular, the general formula (b):
[0025]
[Chemical formula 2]

[0026]
(Wherein Me represents a methyl group and the average number of repeating units of n is 3 to 12), or a partial condensate of tetramethoxysilane represented by the general formula (c):
[0027]
[Chemical 3]

[0028]
(In the formula, Me represents a methyl group, and the average number of repeating units of n is 3 to 12.) A methyltrimethoxysilane partial condensate represented by the following formula is preferred.
[0029]
The methoxy group-containing silane-modified epoxy resin (A) used in the present invention is obtained by subjecting the epoxy resin (1) and the methoxysilane partial condensate (2) to a demethanol condensation reaction in the presence or absence of a solvent. It is done. The amount of the epoxy resin (1) and the methoxysilane partial condensate (2) used is not particularly limited, and the hydroxyl group equivalent of the epoxy resin (1) / the methoxy group equivalent (equivalent ratio) of the methoxysilane partial condensate (2). Although it does not restrict | limit in particular, Usually, it is 0.02-0.6, Preferably it is 0.05-0.5. If the equivalence ratio is less than 0.02, the amount of unreacted methoxysilane partial condensate (2) increases too much, and if it exceeds 0.6 (closer to the stoichiometric amount), the methanol removal reaction proceeds. This is not preferable because it easily gels.
[0030]
Epoxy resin (1) hydroxyl group equivalent / methoxysilane partial condensate (2) methoxy group equivalent (equivalent ratio) of 0.2 or more, or methoxy having an average number of Si of 7 or more per molecule When the silane partial condensate (2) is used as a raw material, if the demethanol condensation reaction is performed until the hydroxyl group of the epoxy resin (1) completely disappears, viscosity increase or gelation tends to occur. In such a case, high viscosity or gelation is prevented by a method such as stopping the methanol removal reaction during the reaction. For example, when the viscosity is increased, the flowing methanol is refluxed to adjust the amount of methanol distilled from the reaction system, or the reaction system is cooled to terminate the reaction.
[0031]
The methoxy group-containing silane-modified epoxy resin (A) used in the present invention is composed of epoxy resin (1), methoxysilane partial condensate (2), and one hydroxyl group in one molecule. And one epoxy group It may be obtained by subjecting an epoxy compound (3) having benzene (hereinafter simply referred to as an epoxy compound (3)) to a demethanol condensation reaction in the presence of a solvent or in the absence of a solvent. By using the epoxy compound (3), the heat resistance of the resulting epoxy resin-silica hybrid cured product can be obtained even when the epoxy resin (1) containing a large amount of epoxy resin having no hydroxyl group is used. Can be improved.
[0032]
Unlike the epoxy resin having a plurality of epoxy groups, the epoxy compound (3) used in the present invention is not particularly limited as long as it is a compound having only one epoxy group. However, the smaller the molecular weight, the epoxy resin (1). And those having 15 or less carbon atoms are preferred because they have good compatibility with the partial condensate of methoxysilane (2) and high heat resistance imparting effect. Specific examples include, for example, monoglycidyl ethers having one hydroxyl group at the molecular end obtained by reacting epichlorohydrin with water and dihydric alcohols; reacting epichlorohydrin with amino monoalcohols. Examples thereof include an epoxy compound having one hydroxyl group at the molecular end obtained; and an alicyclic hydrocarbon monoepoxide having one hydroxyl group in the molecule (for example, epoxidized tetrahydrobenzyl alcohol). Among these epoxy compounds, glycidol is most excellent in terms of the effect of imparting heat resistance, and is also optimal because of its high reactivity with the methoxysilane partial condensate (2).
[0033]
In addition, the usage-amount of the epoxy compound (3) in the case of using an epoxy compound (3) is not specifically limited, What is necessary is just to determine suitably according to content of the molecule | numerator which does not have a hydroxyl group in an epoxy resin (1). However, from the viewpoint of the heat resistance of the resulting epoxy resin-silica hybrid cured product, when using an epoxy resin (1) having no unsaturated bond having 2.0 or less hydroxyl groups in one molecule. The weight of the epoxy compound (3) / the weight of the epoxy resin (1) is about 0.03 or more, and when the number of hydroxyl groups contained in one molecule is 1.0 or less, it is preferably 0.1 or more. . In view of the environment, it is preferable to reduce the amount of the epoxy compound (3) remaining in the methoxy group-containing silane-modified epoxy resin (A) as much as possible. In order to reduce the epoxy compound (3), the production time of the methoxy group-containing silane-modified epoxy resin (A) becomes longer, and the production efficiency is lowered.
[0034]
As a reaction solvent used when the methoxy group-containing silane-modified epoxy resin (A) is produced in the presence of a solvent, the reaction solvent does not react with the epoxy group, and the boiling point is equal to or higher than the reaction temperature of the above methanol removal, And a methoxysilane partial condensate (2) can be used as long as they are conventionally known solvents. Examples of such an organic solvent include methyl ethyl ketone, methyl isobutyl ketone, toluene, xylene, tetrahydrofuran, dimethyl diglycol, dimethyl triglycol, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, N-methylpyrrolidone and the like. Among these, organic solvents that have a boiling point of less than 120 ° C. and can be easily dried, such as methyl ethyl ketone and toluene, are preferable for applications that require processing in a semi-cured state. In addition, when applying to the said solvent-free use, you may depressurize and desolvate the organic solvent solution of the methoxy group containing silane modified epoxy resin (A) manufactured in the presence of a solvent.
[0035]
In addition, when the compatibility between the epoxy resin (1) and the methoxysilane partial condensate (2) is high, the reaction can be performed in the absence of a solvent. The methoxy group-containing silane-modified epoxy resin (A) produced in the absence of a solvent has an advantage that it can be used as it is as a material such as an adhesive, a molded product, and a sealing material. Such a solvent-free methoxy group-containing silane-modified epoxy resin (A) can also be obtained by depressurizing an organic solvent solution of the epoxy resin (A) produced in the presence of a solvent to remove the solvent.
[0036]
In the demethanol condensation reaction, a catalyst that does not open an epoxy ring among conventionally known catalysts can be used for promoting the reaction. Examples of the catalyst include lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, barium, strontium, zinc, aluminum, titanium, cobalt, germanium, tin, lead, antimony, arsenic, cerium, boron, cadmium, manganese. And metals such as oxides, organic acid salts, halides, and methoxides of these metals. Among these, organic tin and organic acid tin are particularly preferable, and specifically, dibutyltin dilaurate, tin octylate and the like are effective.
[0037]
In addition, the reaction temperature in the demethanol condensation reaction is about 50 to 130 ° C., preferably 70 to 130 ° C., and the total reaction time is about 1 to 24 hours. In order to prevent the polycondensation reaction of the methoxysilane partial condensate (2) itself, this reaction is preferably carried out under substantially anhydrous conditions.
[0038]
The methoxy group-containing silane-modified epoxy resin (A) thus obtained has a methoxy group derived from the methoxysilane partial condensate (2) in the molecule. This methoxy group is necessary to form a hybrid cured product bonded to each other by sol-gel reaction or demethanol condensation by heat treatment or reaction with moisture (humidity). Usually, about 40 to 95 mol%, preferably 50 to 90 mol% of the methoxy group of the methoxysilane partial condensate (2) as a raw material is preferably kept unreacted. In the methoxy group-containing silane-modified epoxy resin (A), the methoxysilane partial condensate (2) may be contained unreacted. The unreacted methoxysilane partial condensate (2) is converted into silica by hydrolysis and polycondensation during sol-gel curing, and is bonded to the methoxy group-containing silane-modified epoxy resin (A).
[0039]
In the present invention, the methoxy group-containing silane-modified epoxy resin (A) and the epoxy resin curing agent (B) are used in combination as a silane-modified epoxy resin composition.
[0040]
As the curing agent for epoxy resin (B), a conventionally known curing agent that is usually used as a curing agent for epoxy resin can be used, but since a colorless transparent cured product is obtained, an alicyclic acid anhydride system is obtained. It is preferable to use a curing agent, an anionic polymerization curing agent, a cationic polymerization curing agent, or the like. Examples of the alicyclic acid anhydride curing agent include tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3,6-endomethylenetetrahydrophthalic anhydride, hexachloroendomethylenetetrahydrophthalic anhydride, methyl-3,6-endo. And methylenetetrahydrophthalic anhydride. Anionic polymerization type curing agents include aromatic triamines such as benzyldimethylamine, 2- (dimethylaminomethyl) phenol, 2,4,6-tris (diaminomethyl) phenol, 2-methylimidazole, 2-ethyl-4 Examples include imidazoles such as -methylimidazole, 2-ethylhexylimidazole, 2-undecylimidazole, 1-cyanoethyl-2-methylimidazole. Examples of the cationic polymerization type curing agent include photodegradable curing agents such as aromatic diazonium salts, diallyl iodonium salts, triallyl sulfonium salts, triallyl sulfonium salts and the like.
[0041]
In the silane-modified epoxy resin composition, a known oxidative degradation inhibitor, coloring inhibitor, ultraviolet absorber and the like can be used in order to prevent the cured product from being colored. In addition, if necessary, organic solvents, fillers, release agents, surface treatment agents, flame retardants, viscosity modifiers, plasticizers, antibacterial agents, antifungal agents, leveling agents, antifoaming agents, colorants, You may mix | blend a stabilizer, a coupling agent, etc. in the range which does not impair the effect of this invention. In applying the silane-modified epoxy resin composition of the present invention to various applications, various epoxy resins and rubber components are used to adjust the flexibility and mechanical strength of the epoxy resin-silica hybrid cured product and semi-cured product. Etc. can also be used together. Examples of the epoxy resin that can be used in combination include the novolak type epoxy resin described as a constituent of the present invention; a bisphenol type epoxy resin obtained by reacting bisphenols with epichlorohydrin; polybasic bases such as phthalic acid and dimer acid Glycidyl ester type epoxy resin obtained by reacting acids and epichlorohydrin; Glycidylamine type epoxy resin obtained by reacting polyamines such as diaminodiphenylmethane and isocyanuric acid with epichlorohydrin; Examples thereof include linear aliphatic epoxy resins and alicyclic epoxy resins obtained by oxidation with peracids. Examples of the rubber component include polyisobutene, polybutylene, polybutadiene, butadiene-acrylonitrile rubber, chloroprene rubber, and silicon rubber.
[0042]
In order to obtain an epoxy resin-silica hybrid cured product from the silane-modified epoxy resin composition, sol-gel curing of the methoxysilyl moiety of the methoxy group-containing silane-modified epoxy resin (A) and epoxy curing of the epoxy group must be performed. . In this case, sol-gel curing must be performed prior to epoxy curing. When the epoxy curing is preceded by the sol-gel curing, the epoxy resin-silica hybrid cured product generates foam and cracks due to the generation of methanol resulting from the sol-gel curing.
[0043]
In order for sol-gel curing to precede epoxy curing, it is preferable to incorporate a catalyst for promoting sol-gel curing into the resin composition. Examples of the sol-gel curing catalyst include conventionally known catalysts such as acid or basic catalysts and metal catalysts. In particular, tin octylate and dibutyltin dilaurate are preferable because of high activity and excellent solubility. . The usage-amount of the said catalyst can be suitably determined with the activity of the catalyst to be used, the film thickness of the target hardened | cured material, and the kind of hardening | curing agent (B) for epoxy resins. Usually, the molar ratio of the methoxy group-containing silane-modified epoxy resin (A) to be used is about 0.01 to 5 mol%, such as paratoluenesulfonic acid or tin octylate, which has high catalytic ability, Used in low formic acid, acetic acid, etc. about 0.1-50 mol%
[0044]
In order to obtain a hybrid cured product directly from the silane-modified epoxy resin composition, it is necessary to perform curing by a method according to the type of the curing agent (B) used. This is because methanol is generated by the sol-gel curing reaction of the methoxysilyl moiety, so that the epoxy group in the methoxy group-containing silane-modified epoxy resin (A) and the epoxy resin curing agent (B) are ring-opened. When the methanol is generated after the curing by the crosslinking reaction proceeds, foaming and cracks are generated. Therefore, it is necessary to adjust the sol-gel curing reaction rate by appropriately selecting a catalyst. When using an alicyclic acid anhydride-based curing agent as the curing agent (B), a sol-gel curing catalyst is used in combination with 0.1% or more in addition to the curing agent (B) at 150 to 200 ° C. It is preferable to cure.
[0045]
Moreover, an epoxy resin-silica semi-cured material can be obtained by allowing the silane-modified epoxy resin composition to proceed only with sol-gel curing without allowing epoxy curing to proceed. The semi-cured product is thermoplastic because the epoxy group is uncured, and can be arbitrarily processed by thermoforming or thermocompression bonding.
[0046]
In order to obtain such an epoxy resin-silica semi-cured product, the methoxysilyl moiety is generated at 70% or more, preferably 90% or more while keeping the reaction rate of the epoxy group at 30% or less, preferably 20% or less. You can do it. Specifically, the silane-modified epoxy resin composition to which the sol-gel catalyst is added is preferably heated at 50 to 120 ° C. so that only the sol-gel curing reaction proceeds. When the epoxy curing reaction proceeds over 30%, thermoplasticity is lost due to epoxy curing, and processing cannot be performed. When the reaction rate of the methoxysilyl site is less than 70%, there is a possibility that curing shrinkage, cracks and foaming may occur in the complete curing reaction subsequent to the production of the semi-cured product.
[0047]
Further, such a semi-cured product is completely cured by a method according to the type of the curing agent (B) used, and led to an epoxy resin-silica hybrid cured product. It is also possible to obtain an epoxy resin-silica hybrid cured product directly from the silane-modified epoxy resin composition. The sol-gel curing reaction rate may be adjusted by appropriately selecting the curing agent (B) and the sol-gel catalyst so that the sol-gel curing proceeds prior to the epoxy curing.
[0048]
The resulting epoxy resin-silica hybrid cured product has a high degree of heat resistance, insulation, adhesion, and colorless transparency, and in particular, a light emitting element, a light receiving element, a photoelectric conversion element, a binder for optical transmission related parts, Useful as a constituent material for optical components such as liquid crystal panels, color filters, plastic film protective coating agents, polarizing plates, plastic LAN cables, optical path substrates, pickup lenses, plastic substrates for liquid crystal cells, prisms, and liquid crystal screen coating agents. is there.
[0049]
Among the above-mentioned uses, the protective coating agent for the purpose of protecting the substrate is prepared so as to produce an epoxy resin-silica hybrid having a pencil hardness of 4H to 8H, containing 15 to 60% silica in the cured epoxy-silica hybrid. It is preferable to do this. For optical applications such as polarizing plates, plastic LAN cables, optical path substrates, pickup lenses, plastic substrates, prisms, and liquid crystal screen coating agents, the refractive index of epoxy-silica hybrid is set to 1.5 because of the necessity to prevent light scattering. It is preferable to adjust so that it may become less. For applications that require solder reflow, such as plastic substrates and optical waveguide substrates, the elastic modulus at 230 ° C. is 1 × 10 ⁸ It is preferable to prepare such that it is Pa or higher and the 5% thermal decomposition temperature is 280 ° C. or higher.
[0050]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to this invention, the epoxy resin-silica hybrid hardened | cured material which has high heat resistance, insulation, adhesiveness, and colorless transparency can be provided.
[0051]
【Example】
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In each example, “%” is based on weight unless otherwise specified.
[0052]
Example 1 (Production of methoxy group-containing silane-modified epoxy resin (A))
In a reactor equipped with a stirrer, a condenser, a thermometer, and a nitrogen inlet, a hydrogenated bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., trade name “Santoto ST-4000D”, epoxy equivalent 740 g / eq, hydroxyl equivalent) 380 g / eq) 800 g was dissolved in diglyme 800 g at 120 ° C., and poly (tetramethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “M silicate 51”, average number of Si per molecule 4.0) 726 g Then, 0.7 g of dibutyltin dilaurate was added as a catalyst, and a methanol removal reaction was performed at 120 ° C. for 12 hours to obtain a methoxy group-containing silane-modified epoxy resin (hereinafter referred to as “resin (A-1)”).
The hydroxyl group equivalent of the epoxy resin (1) / the methoxy group equivalent of the methoxysilane partial condensate (2) = 0.137. The epoxy equivalent of the resin (A-1) was 2110 g / eq.
[0053]
Example 2
In the same reactor as in Example 1, 800 g of hydrogenated bisphenol A type epoxy resin (manufactured by Tohto Kasei Co., Ltd., trade name “Santoto ST-4000D”, epoxy equivalent 740 g / eq, hydroxyl group equivalent 380 g / eq) 720 g 908 g of poly (tetramethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “M silicate 51”, average number of Si per molecule 4.0) and 0.02 of dibutyltin dilaurate as a catalyst. 7 g was added and subjected to demethanol reaction at 120 ° C. for 12 hours to obtain a methoxy group-containing silane-modified epoxy resin (hereinafter referred to as “resin (A-2)”).
The hydroxyl group equivalent of the epoxy resin (1) at the time of charging / the methoxy group equivalent of the methoxysilane partial condensate (2) was 0.1. The epoxy equivalent of resin (A-2) was 2200 g / eq.
[0054]
Example 3
In a reactor equipped with a stirrer, a water separator, a thermometer, and a nitrogen inlet, a hydrogenated bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., trade name “Santoto ST-4000D”, epoxy equivalent 740 g / eq, hydroxyl group 400 g of equivalent 380 g / eq), 1042 g of liquid hydrogenated bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., trade name “YX8000”, epoxy equivalent 205 g / eq, no hydroxyl group), and 114 g of glycidol at 120 ° C. Dissolve, poly (tetramethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “M silicate 51”, average number of Si per molecule 4.0) 734 g and dibutyltin dilaurate 2.0 g as a catalyst, For 8 hours at 100 ° C, the methanol produced was allowed to undergo a demethanol reaction while flowing through a water separator. , A methoxy group-containing silane-modified epoxy resin (hereinafter, referred to as resin (A-3)) was obtained.
In addition, the hydroxyl group equivalent of the epoxy resin (1) at the time of charging / the methoxy group equivalent of the methoxysilane partial condensate (2) = 0.068, the weight of glycidol / the epoxy resin having no unsaturated bond (1) = 0.079. The epoxy equivalent of the resin (A-3) was 290 g / eq.
[0055]
Example 4 (Production of methoxy group-containing silane-modified epoxy resin (A))
In a reactor similar to Example 1, 800 g of hydrogenated bisphenol A type epoxy resin (manufactured by Toto Kasei Co., Ltd., trade name “Santoto ST-4000D”, epoxy equivalent 740 g / eq, hydroxyl group equivalent 380 g / eq) 920 g of diglyme. 430 g of poly (methyltrimethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “MTMS-A”, average number of Si per molecule 3.2) and dibutyltin dilaurate 0 as a catalyst. .6 g was added, and a methanol removal reaction was performed at 120 ° C. for 10 hours to obtain a methoxy group-containing silane-modified epoxy resin (hereinafter referred to as “resin (A-4)”).
In addition, the equivalent of the hydroxyl group of the epoxy resin (1) having no unsaturated bond at the time of charging / the equivalent of the methoxy group of the methoxysilane partial condensate (2) was 0.286. The epoxy equivalent of the resin (A-4) was 1950 g / eq.
[0056]
Comparative Example 1
To 800 g of Santo Tote ST-4000D, 800 g of diglyme was added and dissolved. Hereinafter, this resin composition is called resin (a-1).
[0057]
Comparative Example 2
An epoxy resin composition was obtained by mixing 800 g of Santo Tote ST-4000D, 726 g of MS-51 and 800 g of diglyme. Hereinafter, this resin composition is called resin (a-2).
[0058]
Comparative Example 3
Bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name “Epicoat 1001”, epoxy equivalent 472 g / eq) 336.0 g and methyl ethyl ketone 268.8 g were added to the same reactor as in Example 1, and 70 ° C. And dissolved. Further, 360.4 g of poly (tetramethoxysilane) (manufactured by Tama Chemical Co., Ltd., trade name “MS-51”, average number of Si per molecule 4) and 0.3 g of dibutyltin dilaurate as a catalyst were added. The mixture was refluxed at 6 ° C. for 6 hours and then cooled to 50 ° C., and 33.6 g of methanol was added to obtain a methoxy group-containing silane-modified epoxy resin (hereinafter referred to as resin (a-3)). The hydroxyl group equivalent of the bisphenol-type epoxy resin / the methoxy group equivalent of the methoxysilane partial condensate (2) = 0.1, and the epoxy equivalent was 1400 g / eq.
[0059]
Examples 5 to 8 and Comparative Examples 4 to 6 (Preparation of silane-modified epoxy resin composition and preparation of epoxy resin-silica hybrid semi-cured product)
To each of the resins obtained in Examples 1 to 4 and Comparative Examples 1 to 3, 4-methylhexahydrophthalic anhydride (trade name “MH-700”, manufactured by Shin Nippon Rika Co., Ltd.) The acid anhydride group equivalent is added at a ratio of 1/1, tin octylate (manufactured by API Corporation, trade name “STANOCTO”) is added at 1% per solid content, and a silane-modified epoxy resin composition (B-5-5) is added. 8, b-4 to 6).
[0060]
(Evaluation of epoxy resin-silica hybrid semi-cured product)
Each epoxy resin composition obtained in Examples 5 to 8 and Comparative Examples 4 to 6 was poured into a fluororesin-coated container (length × width × depth = 10 cm × 10 cm × 1.5 cm) at 100 ° C. By heating for 15 minutes, the solvent was volatilized and sol-gel curing was performed to obtain an epoxy resin-silica hybrid semi-cured product. The state (appearance, shrinkage, foaming, moldability) of the obtained semi-cured product was evaluated according to the following criteria. The results are shown in Table 1.
[0061]
(Appearance evaluation)
○: Transparent.
Δ: Cloudy
×: Whitened.
[0062]
(Evaluation of shrinkage)
○: There is no crack or warpage in the cured product.
Δ: Warpage exists in the cured product.
X: The cured product has cracks.
[0063]
(Evaluation of foaming)
○: There are no bubbles in the cured product.
Δ: Less than 5 bubbles exist in the cured product.
X: Five or more bubbles exist in hardened | cured material.
[0064]
(Evaluation of moldability)
○: Flexible and rich in moldability.
X: Cracked when deformed.
[0065]
[Table 1]

[0066]
As is clear from Table 1, in Examples 5 to 8 and Comparative Examples 4 and 6, a semi-cured product that was transparent and capable of thermoforming and thermocompression bonding was obtained. However, the semi-cured product obtained in Comparative Example 5 was whitened due to the phase separation of the epoxy resin and silica, and was very brittle. The semi-cured product obtained in Comparative Example 6 was transparent but cracked when deformed. Therefore, the semi-cured products of Examples 5 to 8 are suitable as constituent materials for light-emitting diode encapsulating materials, optical disk substrates, pickup lenses, liquid crystal cell plastic substrates, prisms, and the like that require molding.
[0067]
Examples 9 to 12 and Comparative Examples 7 to 9 (Preparation and Evaluation of Epoxy Resin-Silica Hybrid Cured Product)
The semi-cured products obtained in Examples 5 to 8 and Comparative Examples 4 to 6 were further epoxy cured by heating at 150 ° C. for 3 hours to obtain fully cured products. The state (appearance, shrinkage, foaming) of the obtained completely cured product was evaluated according to the following criteria. The results are shown in Table 2.
[0068]
(Appearance evaluation)
○: Transparent.
Δ: Cloudy
×: Whitened.
[0069]
(Evaluation of shrinkage)
○: There is no crack or warpage in the cured product.
Δ: Warpage exists in the cured product.
X: The cured product has cracks.
[0070]
(Evaluation of foaming)
○: There are no bubbles in the cured product.
Δ: Less than 5 bubbles exist in the cured product.
X: Five or more bubbles exist in hardened | cured material.
[0071]
(Evaluation of coloring)
○: The cured product is colorless and transparent.
(Triangle | delta): Hardened | cured material is yellow transparent.
X: Hardened | cured material is opaque.
[0072]
[Table 2]

[0073]
In Examples 9 to 12, transparent epoxy resin-silica hybrid cured products were obtained. The cured epoxy resin-silica hybrid obtained in Comparative Example 9 was transparent but colored yellow. The completely cured product obtained in Comparative Example 8 was very brittle with unevenness, foaming, and cracks due to phase separation of the epoxy resin and silica.
[0074]
(Heat-resistant)
The cured film obtained in Example 9 and Comparative Example 7 was cut into 5 mm × 20 mm, and viscoelasticity measuring device (manufactured by Rheology, trade name “DVE-V4”, measurement conditions: amplitude 0.5 μm, frequency 10 Hz, The dynamic storage elastic modulus was measured using a slope of 3 ° C./min to evaluate the heat resistance. The measurement results are shown in FIG.
[0075]
As is clear from FIG. 1, the glass transition point of the cured film is increased in Example 9 as compared with Comparative Example 7, and the decrease in elastic modulus is small even at high temperatures, and the heat resistance is excellent. Therefore, the cured product of Example 9 is suitable as a light-emitting diode encapsulant that requires heat resistance, a constituent material of an optical waveguide substrate, and the like.
[0076]
(Heat-resistant decomposition)
The thermogravimetric loss of the cured products obtained in Example 9 and Comparative Example 7 was measured using a differential thermal / thermogravimetric simultaneous measurement apparatus (trade name “TG / DTA220” manufactured by Seiko Instruments Inc., measurement condition: slope 10 (° C./min). The results are shown in Table 3.
[0077]
[Table 3]

[0078]
As apparent from Table 3, Example 9 has a sufficiently high temperature at the time of 10% weight loss as compared with Comparative Example 7 and is excellent in thermal decomposition resistance. Therefore, the sealing material of the light emitting diode, the optical waveguide substrate It is suitable as a constituent material.
[0079]
(Adhesion)
Each epoxy resin composition obtained in Example 9 and Comparative Example 7 was applied to each substrate with a bar coater, and the solvent was volatilized and sol-gel cured by heating at 100 ° C. for 15 minutes. And cured for 3 hours to obtain a cured product having a thickness of 20 μm.
[0080]
The Goban eyes cellophane tape peeling test by the general test method of JIS K-5400 was conducted, and the determination was made according to the following criteria. The evaluation results are shown in Table 4.
A: 100/100
○: 99 to 95/100
Δ: 94-70 / 100
X: 69-0 / 100
[0081]
[Table 4]

[0082]
As is clear from Table 4, the cured film of Example 9 is excellent in adhesion to metals and ceramic substrates as in Comparative Example 7, and includes a liquid crystal screen coating agent, a color filter protective coating agent, and the like. Suitable as a constituent material.
[0083]
(Heat resistant yellowing)
After the cured film on the glass plate used in the above (Adhesion) item was further heated at 200 ° C. for 2 hours, the appearance of the cured film was evaluated according to the following criteria. The results are shown in Table 5.
○: The cured product is colorless and transparent.
Δ: Cured product is yellowed.
X: Cured product is browned.
[0084]
[Table 5]

[0085]
The cured film of Example 9 is not colored even under a high temperature environment as compared with that of Comparative Example 7, and is suitable as a constituent material for light transmission-related parts such as a light-emitting diode sealing material and an optical waveguide substrate.
[0086]
(Scratch resistance)
Using the cured film on the glass plate used in the above item (heat-resistant yellowing), a pencil scratch test was conducted by the paint general test method of JISK-5400. The results are shown in Table 6.
[0087]
[Table 6]

[0088]
Since the cured film of Example 9 has better scratch resistance than that of Comparative Example 7, it is suitable as a constituent material for liquid crystal screen coating agents, color filter protective coating agents, and the like.
[0089]
Examples 13 and 14 and Comparative Example 10 (Preparation of silane-modified epoxy resin composition and preparation of epoxy resin-silica hybrid cured product)
To each resin obtained in Examples 1 and 2 and Comparative Example 1, a photocuring catalyst (photocation generation catalyst (manufactured by Rhodia Co., Ltd., trade name Silicolys CATA211: isopropyl alcohol solution, active ingredient 18%) per solid content 1% was added, tin octylate (product name “STANOCTO” manufactured by API Corporation) was added 1% per solid content to obtain a silane-modified epoxy resin composition, and then heated at 100 ° C. for 15 minutes to volatilize the solvent and Sol-gel curing was performed, and epoxy curing was performed by irradiating with ultraviolet rays using an ultraviolet exposure device, and the refractive index at 589 nm of the obtained cured product was measured.
[0090]
[Table 7]

[0091]
As is clear from Table 7, the refractive index can be controlled by the silica content in the cured product, which is suitable as a constituent material for optical transmission-related parts such as an optical waveguide substrate.
[Brief description of the drawings]
1 is an evaluation result of heat resistance of cured films obtained in Example 9 and Comparative Example 7. FIG.

Claims (8)

A methoxy group-containing silane-modified epoxy resin obtained by subjecting a hydrogenated bisphenol A type epoxy resin (1) having a hydroxyl group and a methoxysilane partial condensate (2) to a demethanol condensation reaction. Hydrogenated bisphenol A type epoxy resin (1) having a hydroxyl group, a methoxysilane partial condensate (2), and an epoxy compound (3) having one hydroxyl group and one epoxy group in one molecule are subjected to a demethanol condensation reaction. A methoxy group-containing silane-modified epoxy resin obtained.   The methoxy group-containing silane-modified epoxy resin according to claim 2, wherein the epoxy compound (3) having one hydroxyl group and one epoxy group in one molecule is glycidol.   The methoxy group-containing silane-modified epoxy resin according to any one of claims 1 to 3, wherein the methoxysilane partial condensate (2) is a partial condensate of tetramethoxysilane. ( Equivalent of hydroxyl group of hydrogenated bisphenol A type epoxy resin (1) having hydroxyl group) / (Equivalent of methoxy group of methoxysilane partial condensate (2)) (equivalent ratio) is 0.02 to 0.6. The methoxy group-containing silane-modified epoxy resin according to any one of claims 1 to 4.   The methoxy group-containing silane-modified epoxy resin (A) according to any one of claims 1 to 5, and an alicyclic acid anhydride curing agent, an anionic polymerization curing agent, and a cationic polymerization curing agent. A silane-modified epoxy resin composition comprising at least one epoxy resin curing agent (B).   An epoxy resin-silica hybrid semi-cured product obtained by heating the silane-modified epoxy resin composition according to claim 6 at 50 to 120 ° C and curing the sol-gel.   An epoxy resin-silica hybrid cured product obtained by completely curing the silane-modified epoxy resin composition or semi-cured product according to claim 6 or 7.

Images