JP4142385B2 - Silicone resin composition and silicone resin molded article - Google Patents

Description

（式中、Ｘは（Ａ）−Ｒ¹−ＯＣＯ−ＣＲ²＝ＣＨ₂、（Ｂ）−Ｒ¹−ＣＲ²＝ＣＨ₂又は（Ｃ）−ＣＨ＝ＣＨ₂で示される反応性官能基のいずれかである。但し、Ｒ¹はアルキレン基、アルキリデン基又はフェニレン基を示し、Ｒ²は水素又はアルキル基を示す）で表されるトリオルガノシリル基が結合しているシリコーン樹脂と、分子中に−Ｒ³−ＣＲ⁴＝ＣＨ₂又は−ＣＲ⁴＝ＣＨ₂（但し、Ｒ³はアルキレン基、アルキリデン基又は−ＯＣＯ−基を示し、Ｒ⁴は水素又はアルキル基を示す）で表される不飽和基を少なくとも１個含み、前記シリコーン樹脂とラジカル共重合が可能な下記一般式（ａ）以外の不飽和化合物と下記一般式（ａ）で表される脂環式不飽和化合物を１０〜６０：１０〜７０：１０〜５０の重量割合で配合したことを特徴とするシリコーン樹脂組成物である。ここで、前記シリコーン樹脂は、末端が篭状に閉じていて、シラノール基を含まない篭型ポリオルガノシルセスキオキサンと下記一般式（２）で示される反応性官能基を有するジシロキサン化合物（式中、Ｘは上記一般式（１）と同じ意味を有する）を有機溶剤中、アルカリ性転位及び縮合触媒の存在下、加熱して平衡化反応させて製造されたものであり、１分子当たり平均１．１個以上の反応性官能基Ｘを有するものである。
【化６】

（式中、Ｚは下記式（ａ１）又は（ａ２）で表される２価の基を示し、また、Ｒは水素又はメチル基を示す）
【化７】

【００１３】
ここで、１）不飽和基が、アクリロイル基、メタクリロイル基、アリル基及びビニル基からなる群から選ばれる少なくとも１種であること、２）シリコーン樹脂が、篭型構造及び片末端が篭型状に閉じたラダー型構造から選ばれる少なくとも１種又はこれらの少なくとも１種とラダー型構造との混合物であること、３）シリコーン樹脂は、末端が篭状に閉じていて、シラノール基を含まない篭型ポリオルガノシルセスキオキサンと下記一般式（２）で示される反応性官能基を有するジシロキサン化合物（式中、Ｘは上記一般式（１）と同じ意味を有する）を有機溶剤中、アルカリ性転位及び縮合触媒の存在下、加熱して平衡化反応させて製造されたものであり、１分子当たり平均１．５個以上の反応性官能基Ｘを有するものであること、又は、４）不飽和化合物が、１分子中に不飽和基を２〜５個有するモノマー又はオリゴマーを含有し、１分子当たり平均１．１個以上の不飽和基を有するものであることは、本発明のシリコーン樹脂組成物の好ましい態様の一つである。
【化８】

【００１４】
また、本発明は、前記のシリコーン樹脂組成物を、加熱又はエネルギー線を照射してラジカル共重合させることを特徴とするシリコーン樹脂共重合体の製造方法である。更に、本発明は、前記のシリコーン樹脂組成物を、ラジカル共重合させて得られたシリコーン樹脂共重合体又はその成形体である。ここで、前記シリコーン樹脂共重合体又は成形体は、ガラス転移温度及び５％重量減少温度のいずれの物性値も３００℃以上であり、且つ、全光線透過率が８５％以上、吸水率が１．０％以下であることが好ましい。
【００１５】
以下、本発明を具体的に説明する。
本発明のシリコーン樹脂組成物は、シリコーン樹脂とこれと共重合可能な不飽和化合物を主要成分とする。本発明のシリコーン樹脂共重合体は、このシリコーン樹脂組成物をラジカル共重合させて得られる。本発明の成形体は、このシリコーン樹脂組成物を成形硬化又はこのシリコーン樹脂共重合体を成形して得られる。本発明のシリコーン樹脂共重合体は、架橋重合体であって、この場合、熱硬化性樹脂と同様な成形硬化法が採用できる。以下、シリコーン樹脂組成物、シリコーン樹脂共重合体及びその製法及び成形体の順に説明する。
【００１６】
本発明に用いられるシリコーン樹脂の最大の特徴は、末端に反応性官能基を有する篭型構造を有するポリオルガノシルセスキオキサン（篭型ポリオルガノシルセスキオキサンともいう）を含んでいることである。前述したように、従来のシリコーン樹脂はラダー型、非ラダー型を問わず、アクリル樹脂のような官能基を有する有機化合物との相溶性が低く、これらの組成物からは透明な成形体を得ることはできなかった。しかしながら、本発明のシリコーン樹脂は、有機化合物との相溶性が高いアルキル基やフェニル基等の置換基が篭の外側に張り出し、逆に有機化合物との相溶性が低いシロキサン骨格部分が篭の内側に取り込まれることにより、擬似的なミセル構造を形成しているため、アクリルモノマー、オリゴマー等の不飽和化合物と任意の比率で混合することができる。
【００１７】
本発明に用いられるシリコーン樹脂は、一般式(i)で表されるポリオルガノシルセスキオキサンの分子鎖末端に位置するＳｉＯの少なくとも一部に、前記した一般式（１）で示される反応性官能基Ｘを有するトリオルガノシリル基が結合した構造式からなるものであって、通常はＧＰＣにより測定されるポリスチレン換算の重量平均分子量Ｍｗが８００〜１００，０００、好ましくは８００〜５，０００のものである。一般式（１）において、Ｘは上記（Ａ）〜（Ｃ）で表される反応性官能基であり、一般式(i)において、ｎは繰り返し数を示し、その平均値は上記Ｍｗから容易に計算される。
【００１８】
その具体的な構造式としては、下記構造式（３）に示した篭型構造体、構造式（４）に示した片末端が篭状に閉じたラダー構造体が挙げられる。本発明に用いられるシリコーン樹脂は、上記の篭型構造体、ラダー構造体又は両者を必須とし、その割合は５０ｗｔ％以上、好ましくは７０ｗｔ％以上である。その他のシリコーン樹脂としては、構造式（５）に示したラダー構造体があり、これの含有割合は５０ｗｔ％未満であることがよい。各構造式において、Ｙの一部、好ましくは全部が一般式（１）で表されるトリオルガノシリル基である。
【００１９】
なお、以下、本発明で使用するシリコーン樹脂を説明するにあたり、ポリオルガノシルセスキオキサンの例としてオクタフェニルシルセスキオキサンで代表することがあるが、本発明はこれに制限されるものではない。
また、篭型ポリオルガノシルセスキオキサンとは、構造式（３）又は構造式（４）のような篭型構造を分子中に有するものをいう。
【００２０】
【化９】

【化１０】

【化１１】

（上記各式中、Ｙの少なくとも一部は、一般式（１）で表されるトリオルガノシリル基を示し、ｎは繰返し数を示す）
【００２１】
末端が篭状に閉じていて、シラノール基を含まない篭型ポリフェニルシルセスキオキサンとしては、前記した特公昭４０−１５９８９号公報や特開平10-251407号公報等に記載されているように、フェニルトリクロロシランを有機溶媒中、加水分解してフェニルトリヒドロキシシランとし、アルカリ性転位及び縮合触媒を用いて加熱し、脱水縮重合させて得られる篭型オクタフェニルシルセスキオキサンが好適に用いられる。
【００２２】
本発明で使用するシリコーン樹脂は、上記のような篭型ポリフェニルシルセスキオキサン又はこれを含むポリフェニルシルセスキオキサンと、一般式（２）で表されるジシロキサン化合物と反応させる方法などにより得ることができる。
一般式（１）及び（２）で示される反応性官能基Ｘは、（Ａ）−Ｒ¹−ＯＣＯ−ＣＲ²＝ＣＨ₂、（Ｂ）−Ｒ¹−ＣＲ²＝ＣＨ₂又は（Ｃ）−ＣＨ＝ＣＨ₂で示される基のいずれかである。なお、各式中のＲ¹はアルキレン基、アルキリデン基又はフェニレン基を示すが、炭素数１〜６の低級アルキレン基、炭素数１〜６のアルキリデン基又はフェニレン基が好ましい。また、Ｒ²は水素又はアルキル基を示すが、水素又は炭素数１〜６の低級アルキル基（有利にはメチル基）が好ましい。
一般式（２）で表されるジシロキサン化合物の製造方法としては、例えば、ジメチルクロルシランとアリル（メタ）アクリレートを、塩化白金酸を触媒としてヒドロシリレーション反応を行い、その後加水分解、縮重合することにより反応性官能基Ｘが−Ｃ₃Ｈ₆−ＯＣＯ−Ｃ（ＣＨ₃）＝ＣＨ₂、すなわち前記（Ａ）であるジシロキサン化合物が容易に得られる。
【００２３】
ポリフェニルシルセスキオキサンと、上記ジシロキサン化合物との反応に使用するアルカリ性転位及び縮合触媒としては、一般的なラダー型又は篭型のポリフェニルシルセスキオキサンの合成に用いられる水酸化セシウム、水酸化カリウム、水酸化ナトリウム、水酸化ルビジウム等のアルカリ金属水酸化物、あるいはテトラメチルアンモニウムヒドロキサイド、テトラエチルアンモニウムヒドロキサイド、ベンジルトリメチルアンモニウムヒドロキサイド、ベンジルトリエチルアンモニウムヒドロキサイド等の水酸化アンモニウム塩、テトラブチルフォスフォニウムハイドロキサイド、テトラエチルフォスフォニウムハイドロキサイド等のテトラオルガノフォスフォニウム化合物を使用できる。
【００２４】
電子材料用途をはじめとしてアルカリ金属イオンが本体中に残存することを嫌う場合は、水酸化アンモニウム塩等が選ばれる。また、反応時間の短縮を目的にして反応温度を１３０℃以上に設定して本平衡化反応を行う場合には、水酸化アンモニウム塩等は分解するので、アルカリ金属水酸化物が好んで用いられ、その中でも反応性が大きい水酸化セシウムが好んで用いられる。アルカリ性転位及び縮合触媒の添加量は、原料であるジシロキサン化合物の重量に対し０．０１〜２０重量％の範囲で用いるのが好ましい。０．０１重量％以下では目的物の収率が非常に小さく、２０重量％以上では篭型ポリフェニルシルセスキオキサンが単独で高分子量化する副反応が支配的に進行し、目的の生成物とこれら副生成物及び触媒の再沈操作による分離・精製が容易ではなくなる。
【００２５】
上記反応において使用される有機溶剤としては、ベンゼン、トルエン、キシレン、エチレングリコールジメチルエーテル、Ｎ−メチル−２−ピロリジノン、Ｏ−ジクロロベンゼン、ジフェニルエーテル、１，４−ジオキサン、アセトン、メチルエチルケトン、メチルイソブチルケトン、酢酸エチル、酢酸ブチル、アセト酢酸エチル、エチレングリコールモノメチルエーテル、プロピレングリコールモノメチルエーテル、シクロヘキサン、ベンゾニトリル、メチルフェニルエーテル、メシチン、デュレン、ｍ−ジメトキシベンゼン、ジフェニル、塩化ジフェニル、クロロベンゼン等が例示されるが、これに何ら制限されるものではない。
上記有機溶剤の中では、特にベンゼン、トルエン、キシレン等の非極性溶剤を選択するのが好ましい。その理由は、それらに対して溶解性の低い篭型オクタフェニルシルセスキオキサンと溶解性の高いジシロキサン化合物とを水酸化セシウム又はテトラメチルアンモニウムヒドロキサイド等のアルカリ性触媒下で平衡化反応を行わせる場合は、篭型オクタフェニルシルセスキオキサンがシリル化されることにより溶剤中に溶解していくので反応の進行具合及び終了時点が観測されやすく、また未反応の篭型オクタフェニルシルセスキオキサンと目的生成物との濾過による分離が容易になるからである。
【００２６】
前記ポリフェニルシルセスキオキサンとジシロキサン化合物とのアルカリ触媒下での平衡化反応は、前記した一例の反応機構により進行するが、これは篭型ポリフェニルシルセスキオキサン単独での開環、あるいは、高分子量化反応と競争関係にあるため、前者をできる限り優先的に行う必要がある。また、この反応は基本的に平衡化反応であることから、目的の末端に反応性官能基を含有する篭型及びラダー型ポリフェニルシルセスキオキサンの重量平均分子量Ｍｗ、収率や生成速度が、反応温度、反応時間、両原料の添加量比、アルカリ触媒量等によって自ずと決定されるため以下に記した条件下で行うのが好ましい。
【００２７】
すなわち、篭型ポリフェニルシルセスキオキサンの添加量Ａとジシロキサン化合物の添加量Ｂの重量比Ｂ／Ａは、０．０１≦Ｂ／Ａ≦１００の範囲から選ばれるのが好ましく、更に好ましくは０．０１≦Ｂ／Ａ≦１０である。Ｂ／Ａが０．０１未満の場合は、反応性官能基は殆ど導入されず、単独で高分子量化する副反応が優先する。またＢ／Ａが１００場合は、末端に反応性官能基を含有する篭型及びラダー型ポリフェニルシルセスキオキサンが選択的に収率よく合成されるが、反応系中には未反応のジシロキサン化合物が多量に残存することになり、目的の生成物との再沈操作による分離・精製が容易ではなくなるため不適当である。
【００２８】
上記平衡化反応は一般的に、より高温条件下で行うことによりアルカリ性触媒のシロキサン結合への溶解性が増大し、反応速度及び反応収率が大きくなる傾向にあるが、逆にジシロキサンと篭型ポリフェニルシルセスキオキサンのアルカリ性触媒に対する反応性の差が結果的に小さくなり、反応選択性は減少する方向へ進む。即ち、篭型ポリフェニルシルセスキオキサンが単独で高分子量化する副反応が誘発される。故に反応温度は６０〜２００℃の範囲が好ましく、更には１００〜１５０℃の範囲が特に好ましい。また、ジシロキサン化合物が末端に有する官能基種によっては、例えばアクリロイル基やメタクリロイル基などは反応温度が高すぎると官能基間で自己重合反応を起こすので、反応温度を抑制するか、場合によっては重合禁止剤等を添加するなどの処置が必要である。反応時間については、反応温度、撹拌効率によって多少変化するが、目的とする平衡化反応を十分達成するためには、上記温度範囲内で１〜７２時間が好ましい。
上記製造方法で得られるシリコーン樹脂は、篭型構造体、末端篭型ラダー型構造体及びラダー型構造体のいずれかを単独又は２種以上含む混合物であるが、条件を選択することにより、実質的に又は９０ｗｔ％以上が篭型構造体又は末端篭型ラダー型構造体のみからなるもの、実質的に又は９０ｗｔ％以上が篭型構造体及び末端篭型ラダー型構造体の両者からなるもの、５０ｗｔ％以上が篭型構造体、末端篭型ラダー型構造体又は両者からなり、他がラダー型構造体からなる混合物などが得られる。これらの反応条件は上記説明あるいは上記の刊行物の記載等から容易に理解される。
【００２９】
本発明に用いられるシリコーン樹脂は、上記製法で得られたものに限らず、構造単位中に篭型構造を有するポリオルガノシルセスキオキサンを主たる成分とするポリオルガノシルセスキオキサンであって、ポリオルガノシルセスキオキサンのシロキシ基（ＳｉＯ−）の少なくとも一部に、一般式（１）で示される反応性官能基を有するものであればよい。反応性官能基は一分子中に１〜４個を有することが好ましく、架橋構造の共重合体を得るためには１．１個以上有することがよい。また、このシリコーン樹脂は、多くの有機化合物に対し良好な相溶性を有しているため、アクリレート、メタクリレート、アリル化合物、ビニル化合物等の不飽和基を有する不飽和化合物と任意の比率で混合し、組成物とすることができる。
【００３０】
本発明のシリコーン樹脂組成物において、シリコーン樹脂と共に使用される不飽和化合物は、少なくとも前記一般式（ａ）で表される脂環式不飽和化合物を含む。更に、不飽和化合物は、上記脂環式不飽和化合物と共に非脂環式不飽和化合物を含むことが有利である。ここで、非脂環式不飽和化合物としては、鎖式不飽和化合物や芳香族不飽和化合物が好ましく挙げられる。
【００３１】
不飽和化合物の必須成分として使用される脂環式不飽和化合物は、上記一般式（ａ）で表される。
具体的な化合物としては、Ｚが(a1)、Ｒが水素であるジシクロペンタニルジアクリレート（＝トリシクロ[５．２．１．０^2,6]デカンジアクリレート）、Ｚが(a2)、Ｒが水素であるペンタシクロ[６．５．１．１^3,6．０^2,7．０^9,13]ペンタデカンジアクリレートがある。
【００３２】
非脂環式不飽和化合物は、分子中に−Ｒ³−ＣＲ⁴＝ＣＨ₂又は−ＣＲ⁴＝ＣＨ₂で表される不飽和基を少なくとも１個含み、前記シリコーン樹脂とラジカル共重合が可能な不飽和化合物である。ここで、Ｒ³はアルキレン基、アルキリデン基又は−ＯＣＯ−基を示すが、アルキレン基及びアルキリデン基としては、炭素数１〜６の低級アルキレン基及びアルキリデン基が好ましい。Ｒ⁴は水素又はアルキル基を示すが、好ましくは水素又はメチル基である。好ましい不飽和基としては、アクリロキシ基、メタクリロキシ基又はアリル基及びビニル基からなる群から選ばれる少なくとも１種が挙げられる。
【００３３】
非脂環式不飽和化合物は、構造単位の繰り返し数が２〜２０程度の重合体である反応性オリゴマーと、低分子量、低粘度の反応性モノマーに大別される。また、不飽和基を１個有する単官能不飽和化合物と２個以上有する多官能不飽和化合物に大別される。良好な３次元架橋体を得るためには、多官能不飽和化合物を極少量（１％以下程度）含むことがよいが、共重合体の耐熱性、強度等を期待する場合には１分子当たり平均１．１個以上、好ましくは１．５個以上とすることがよい。このためには、単官能不飽和化合物と不飽和基を２〜５個有する多官能不飽和化合物を混合使用したりして、平均の官能基数を調整することがよい。
【００３４】
反応性オリゴマーとしては、エポキシアクリレート、エポキシ化油アクリレート、ウレタンアクリレート、不飽和ポリエステル、ポリエステルアクリレート、ポリエーテルアクリレート、ビニルアクリレート、ポリエン／チオール、シリコーンアクリレート、ポリブタジエン、ポリスチリルエチルメタクリレート等を例示することができる。これらには、単官能不飽和化合物と多官能不飽和化合物がある。
【００３５】
反応性の単官能モノマーとしては、スチレン、酢酸ビニル、Ｎ−ビニルピロリドン、ブチルアクリレート、２−エチルヘキシルアクリレート、ｎ−ヘキシルアクリレート、シクロヘキシルアクリレート、ｎ−デシルアクリレート、イソボニルアクリレート、ジシクロペンテニロキシエチルアクリレート、フェノキシエチルアクリレート、トリフルオロエチルメタクリレート等を例示することができる。
反応性の多官能モノマーとしては、一般式（ａ）以外の不飽和化合物であるトリプロピレングリコールジアクリレート、１，６−ヘキサンジオールジアクリレート、ビスフェノールＡジグリシジルエーテルジアクリレート、テトラエチレングリコールジアクリレート、ヒドロキシピバリン酸ネオペンチルグリコールジアクリレート、トリメチロールプロパントリアクリレート、ペンタエリスリトールトリアクリレート、ペンタエリスリトールテトラアクリレート、ジペンタエリスリトールヘキサアクリレート等を例示することができる。
【００３６】
本発明で使用する不飽和化合物としては、以上に例示したもの以外に、例えば（株）総合技術センター１９８９年発行の成書「紫外線硬化システム」に記載された各種反応性オリゴマー、モノマーを用いることができるが、これに何ら制限されるものではない。また、これらの反応性オリゴマーやモノマーは、それぞれ単独で使用しても、２種類以上を混合して使用してもよい。
【００３７】
本発明のシリコーン樹脂組成物は、シリコーン樹脂と前記不飽和化合物を配合してなる。ここで、不飽和化合物の全部が上記一般式（ａ）で表される脂環式不飽和化合物であってもよいが、上記非脂環式不飽和化合物を含むことが望ましい。この場合の重量配合割合は、シリコーン樹脂：非脂環式不飽和化合物：脂環式不飽和化合物＝５〜８０：０〜８０：１０〜５０、好ましくは１０〜６０：１０〜７０：１０〜５０である。シリコーン樹脂の割合が多いと得られる共重合体は、シリコーン樹脂としての物性が優勢となるが、その欠点のいくつかが改良される。不飽和化合物の割合が多いと得られる共重合体は、不飽和化合物からの樹脂としての物性が優勢となるが、その欠点のいくつかが改良される。
【００３８】
本発明のシリコーン樹脂組成物はこれをラジカル共重合することにより、シリコーン樹脂共重合体を得ることができる。シリコーン樹脂共重合体の物性を改良するため又はラジカル共重合を促進するためなどの目的で、本発明のシリコーン樹脂組成物に種々の添加剤を配合することができる。反応を促進する添加剤として熱重合開始剤、熱重合促進剤、光重合開始剤、光開始助剤、鋭感剤等を例示することができる。光重合開始剤又は熱重合開始剤を配合する場合、その添加量はシリコーン樹脂と不飽和化合物の合計１００重量量に対して、０．１〜５重量部の範囲とすることがよく、０．１〜３重量部の範囲とすることが更に好ましい。この添加量が０．１重量部に満たないと硬化が不十分となり、得られる成形体の強度、剛性が低くなり、一方、５重量部を超えると成形体の着色等の問題が生じるおそれがある。
【００３９】
本発明のシリコーン樹脂組成物には、本発明の目的から外れない範囲で各種添加剤を添加することができる。各種添加剤として有機／無機フィラー、可塑剤、難燃剤、熱安定剤、酸化防止剤、光安定剤、紫外線吸収剤、滑剤、帯電防止剤、離型剤、発泡剤、核剤、着色剤、架橋剤、分散助剤等を例示することが出来るが、これに何ら制限されるものではない。
【００４０】
本発明のシリコーン樹脂組成物をラジカル共重合することによりシリコーン樹脂共重合体を得ることができる。また、シリコーン樹脂組成物を所定の形状として、ラジカル共重合することによりシリコーン樹脂共重合体の成形体を得ることができる。ラジカル共重合には、加熱又は電子線、紫外線等のエネルギー線照射が適当である。
【００４１】
このようにして得られた本発明のシリコーン樹脂共重合体（成形体）は、動的熱機械分析装置（ＤＭＡ）又は熱機械分析装置（ＴＭＡ）で測定したガラス転移温度と、熱重量分析装置（ＴＧＡ）で測定した５％重量減少温度のいずれの物性値も３００℃以上であり、且つ全光線透過率（厚み０．７ｍｍ）が８５％以上であり、更に、吸水率が１％以下であるものとすることができる。したがって、高耐熱、高透明性、高い寸法安定性を有しているため、ガラスに替わって様々な用途に用いることができる。
【００４２】
【実施例】
以下、本発明の実施例を示す。なお、下記の実施例に使用したシリコーン樹脂は、下記の合成例に示した方法で得たものである。
【００４３】
合成例１
まず、特公昭４０−１５９８９号公報に記載された方法を使用して篭型オクタフェニルシルセスキオキサンの製造例を示す。１０５ｇのフェニルトリクロロシラン（０．５モル）を５００ｃｃのベンゼンに溶解し、水で加水分解が完了するまで振とうする。加水分解生成物を水洗後、市販の３０％ベンジルトリメチルアンモニウムヒドロキサイド溶液１６．６ｃｃ（０．０３モル）を加え、この混合物を４時間還流温度に加熱した。次いで全体を冷却し、約９６時間放置した。この時間経過後、得られたスラリーを再び２４時間還流温度に加熱し、次いで冷却し濾過した。かくして篭型オクタフェニルシルセスキオキサン約７５ｇを得た。赤外吸収スペクトル分析を測定したところ、Ｓｉ−Ｃ₆Ｈ₅に帰属される吸収が１５９５ｃｍ^-1及び１４３０ｃｍ^-1に、Ｓｉ−Ｏ−Ｓｉの逆対称伸縮振動に帰属される吸収が１１３５ｃｍ^-1に観測され、Ｓｉ−ＯＨに帰属される吸収は３４００ｃｍ^-1に観測されなかった。²⁹Ｓｉ−ＭＡＳＮＭＲを測定したところ−７７ｐｐｍに篭型オクタフェニルシルセスキオキサン中のＳｉ核のシャープなシグナルが観測された。J. Polymer Sci.Part A Vol.33, 55‐62(1995)に記載されたような、ヒドロキシル基と結合したＳｉ核は−７０ｐｐｍ及び−６２ｐｐｍに観測されなかった。
【００４４】
次に、反応容器中に上記の篭型オクタフェニルシルセスキオキサン８重量部と１，３−ビス（３−メタクリロキシプロピル）−１，１，３，３−テトラメチルジシロキサン８重量部と、トルエン３２重量部と、水酸化セシウム０．１６重量部と、重合禁止剤（精工化学社製メトキノン）０．０３重量部を仕込み、この混合物を還流温度にて強撹拌し７時間加熱した。仕込み時は篭型オクタフェニルシルセスキオキサンの白色粉末はトルエンに溶解しなかったが、反応が進むにつれ徐々に溶解し、７時間後にはすべて溶解した。この溶液を室温まで冷却し、不溶な未反応の水酸化セシウムを濾過により除去した後、メタノール５００重量部に注ぎ込み、末端にメタクリロイル基を有したシリル化ポリフェニルシルセスキオキサンを沈殿せしめた。沈殿生成物を濾別した後、真空乾燥して、白色固体の末端にメタクリロイル基を有した単一構造の篭型シリル化ポリフェニルシルセスキオキサン（シリコーン樹脂）１４重量部を得た。
【００４５】
ＧＰＣによりポリスチレン換算の重量平均分子量Ｍｗを測定したところ約１５００であった。ＫＢｒ錠剤法により赤外吸収スペクトル分析を測定したところ、Ｓｉ−Ｃ₆Ｈ₅に帰属される吸収が１５９５ｃｍ^-1及び１４３０ｃｍ^-1に、Ｓｉ−Ｏ−Ｓｉの逆対称伸縮振動に帰属される吸収が１１３５ｃｍ^-1と１０２０ｃｍ^-1に観測され、該オリゴマー（シリコーン樹脂）中にはラダー構造を有するものは少なく、その多くは篭型構造を有しているのが分かった。また、Ｓｉ−ＯＨに帰属される吸収は３４００ｃｍ^-1に観測されなかった。¹Ｈ−ＮＭＲ及び¹³Ｃ−ＭＡＳＮＭＲを測定したところ、３−メタクリロキシプロピルジメチルシリル基とフェニル基中のＨ核とＣ核が観測された。また、²⁹Ｓｉ−ＭＡＳＮＭＲを測定したところ１０．９ｐｐｍに３−メタクリロキシプロピルジメチルシリル基中のＳｉ核と７９．２ｐｐｍに篭型オクタフェニルシルセスキオキサン骨格中のＳｉ核が強度比２：８で観測され、７．７ｐｐｍに再沈操作にて除かれず該オリゴマー中に若干含まれている原料１，１，３，３テトラメチル−１，３−ジ（３−メタクリロキシプロピル）ジシロキサン中のＳｉ核も観測された。また、ヒドロキシル基と結合したＳｉ核のシグナル−７０ｐｐｍ及び−６２ｐｐｍは観測されなかった。
【００４６】
合成例２
まず、特公昭４０−１５９８９号公報に記載された方法を使用してシラノールのないラダー型フェニルポリシロキサンプレポリマーの製造例を示す。５００部のトルエンに中に溶解した約５００部のフェニルトリクロロシランを徐々に撹拌下２０００部の水の中に加えた。そして酸層は分別し、トルエン溶液の形の樹脂層は残留する水とＨＣｌを除去するため共沸蒸留せしめた。その後、計算量のヒドロキシ基のないフェニルポリシロキサンの重量に対しＫＯＨ約０．０７８％加え、トルエン溶液を撹拌下９時間還流し、シラノールのないラダー型フェニルポリシロキサンプレポリマーを得た。トルエン溶液の約５０．３％からなる得られたシラップ状フェニルポリシロキサンプレポリマーは式Ｃ₆Ｈ₅ＳｉＯ_1.5の循環単位からなるものであった。固体のフェニルプレポリマーの分離は、このフェニルポリシロキサンのトルエン溶液を約１．５倍の重量のミネラルスピリット（沸点約１５６−１９６℃、Ｋ．Ｂ値約３７）で希釈して行った。得られたスラリーを約１０分間強力に撹拌し、次いで濾別し、得られた固体を約１６時間風乾し、次いで１５０℃で４時間乾燥した。
かくして得られるプレポリマーの赤外吸収スペクトル分析を測定したところ、Ｓｉ−Ｃ６Ｈ５に帰属される吸収が１５９５ｃｍ^-1及び１４３０ｃｍ^-1に、また該プレポリマーがラダー構造を有することを示すＳｉ−Ｏ−Ｓｉの逆対称伸縮振動に帰属される吸収が１１３５ｃｍ^-1及び１０４５ｃｍ^-1に観測され、Ｓｉ−ＯＨに帰属される吸収は３４００ｃｍ^-1に観測されなかった。²⁹Ｓｉ−ＭＡＳＮＭＲを測定したところ−７７ｐｐｍにラダー型フェニルポリシロキサンプレポリマー中のＳｉ核による線幅が多少広くなったシグナルが観測され、ヒドロキシル基と結合したＳｉ核のシグナル−７０ｐｐｍ及び−６２ｐｐｍは観測されなかった。
【００４７】
次に、キシレン５０重量部中に上記で製造したシラノール基を有さないラダー型フェニルポリシロキサンプレポリマー（ＧＰＣによるポリスチレン換算の重量平均分子量Ｍｗ４０００）１０重量部と１，３−ビス（３−メタクリロキシプロピル）−１，１，３，３−テトラメチルジシロキサン５０重量部を溶解させ、水酸化カリウム５重量部と、重合禁止剤（精工化学社製メトキノン）０．０５重量部を添加し、この混合物を還流温度にて撹拌し１０時間加熱した。この溶液を室温まで冷却し、不溶な未反応の水酸化セシウムを濾過により除去した後、ｎ−ヘキサン１０００重量部に注ぎ込み、末端にメタクリロイル基を有したシリル化ポリフェニルシルセスキオキサンを沈殿せしめた。沈殿生成物を濾別した後、真空乾燥して、白色固体の末端にメタクリロイル基を有したラダー型シリコーン樹脂１２重量部を得た。
ＧＰＣによりポリスチレン換算の重量平均分子量Ｍｗを測定したところ約５０００であった。赤外吸収スペクトル分析を測定したところ、Ｓｉ−Ｃ₆Ｈ₅に帰属される吸収が１５９５ｃｍ^-1及び１４３０ｃｍ^-1に、また該ポリマーがラダー構造を有することを示すＳｉ−Ｏ−Ｓｉの逆対称伸縮振動に帰属される吸収が１１３５ｃｍ^-1及び１０４５ｃｍ^-1に観測され、Ｓｉ−ＯＨに帰属される吸収は３４００ｃｍ^-1に観測されなかった。¹Ｈ−ＮＭＲを測定したところ、３−メタクリロキシプロピルジメチルシリル基とフェニル基中のＨ核が観測された。
合成例１で得たシリコーン樹脂はかご型体が主成分であり、合成例２で得たシリコーン樹脂ははラダー型体がほぼ１００％であった。
【００４８】
実施例１
合成例１で得たメタクリロイル基を有した篭型シリル化ポリフェニルシルセスキオキサン（シリコーン樹脂）：５０重量部、トリメチロールプロパントリアクリレート：４０重量部、ジシクロペンタニルジアクリレート：１０重量部、光重合開始剤として１−ヒドロキシシクロヘキシルフェニルケトン：２重量部を混合し、透明なシリコーン樹脂組成物を得た。
次に、ロールコーターを用いて、厚さ１．０ｍｍになるようにキャスト（流延）し、３０Ｗ／ｃｍの高圧水銀ランプを用い、１０００ｍＪ／ｃｍ²の積算露光量で硬化させ、所定の厚みとしたシート状のシリコーン樹脂成形体を得た。
【００４９】
実施例２〜５及び比較例１〜７
配合組成を表１に示す割合とした他は、実施例１と同様にして樹脂成形体を得た。得られた成形体の物性値をまとめて表２に示した。
【００５０】
略号は次のとおり。
Ａ：合成例1で得られた化合物（シリコーン樹脂）
Ｂ：合成例２で得られた化合物（シリコーン樹脂）
Ｃ：トリメチロールプロパントリアクリレート
Ｄ：ジシクロペンタニルジアクリレート（共栄社化学（株）製ライトアクリレートＤＣＰ−Ａ：一般式（ａ）において、Ｚが（a2）で、ＲがＨ）
Ｅ：１−ヒドロキシシクロヘキシルフェニルケトン（重合開始剤）
【００５１】
【表１】

【００５２】
【表２】

【００５３】
１）破断強さ、引張破断伸び（参考規格JIS K 7162）：試験片試験速度５．０ｍｍ／分、チャック間距離５０ｍｍ
２）曲げ弾性率（参考規格JIS K 7171準拠）：試験速度０．３ｍｍ／分、支点間距離１２ｍｍ、支点半径０．５ｍｍ、圧子半径１．５ｍｍ
３）ガラス転移温度：動的熱機械分析法（DMA）、昇温速度５℃／ｍｉｎ、チャック間距離１０ｍｍ
４）5％重量減少温度（Td⁵）：熱重量分析装置（TGA）により、窒素雰囲気下、10℃/minの昇温速度にて測定
５）全光線透過率（参考規格JIS K 7361-1準拠）：試料厚み０．７ｍｍ
６）吸水率（参考規格JIS K 7209準拠）：試料予備乾燥条件５０℃、２４時間
７）成形性：樹脂組成物を基材上で上記実施例の条件にて硬化させ、基材上に２ｍｍ厚みのシート状の硬化物（成形体）を形成した。当該成形体を基材から取り外す際の取り外し易さを下記基準にて評価した。
〇：非常に取り外し安いもの
△：通常の取り外しでは問題ないが、１０枚に１枚程度割れが生じるもの
×：割れやすく取り外しが困難なもの
８）熱変形性：厚み０．４ｍｍ（１００×１００ｍｍ）の成形体を１６０℃の熱風循環式オーブンに１時間入れ、そり、うねりの有無を目視にて評価した。
〇：そり、うねりが認められないもの
△：そりが認められたもの
×：波うち状のうねりが認められたもの
【００５４】
【発明の効果】
本発明の組成物は、耐熱性及び可視光線の透過率が優れた樹脂共重合体を与える。また、本発明の成形体は吸水率が低く、高い寸法安定性と高い成形性を有しているため、ガラスに替わって様々な用途に用いることができる。[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to a silicone resin composition and a silicone resin molded body that is a three-dimensional cross-linked product thereof. Specifically, in place of inorganic glass, optical applications such as lenses, optical disks, optical fibers, and flat panel display substrates, and various transport machines. The present invention relates to a transparent member having a light weight and high impact strength that can be applied to window materials for houses and houses.
[0002]
[Prior art]
Since inorganic glass has high transparency, heat resistance, and dimensional stability, it has been used in a wider range of industrial fields since long ago as a structure that transmits visible light while separating spaces but does not hinder visibility. . Although it is an inorganic glass having such excellent characteristics, it has two major drawbacks: its specific gravity is as heavy as 2.5 or more, and it is weak against impact and easily broken. In particular, as a result of recent progress in downsizing such as light weight and thinning in all industrial fields, users are increasingly demanding improvement of the above defects.
As a material that meets such demands from the industry, there are high expectations for transparent thermoplastic and thermosetting plastics. Here, examples of the transparent thermoplastic plastic include PMMA (polymethyl methacrylate) and PC (polycarbonate). Among them, PMMA is also called organic glass, and has attracted attention as a material that has excellent transparency and overcomes the two major drawbacks of glass. However, these transparent plastics are extremely inferior in heat resistance as compared with inorganic glass, and there is a problem that their use is limited.
[0003]
On the other hand, examples of transparent thermosetting plastics include epoxy resins, curable (meth) acrylate resins, silicone resins, and the like, and these generally have higher heat resistance than the above thermoplastics. . Among these, epoxy resins have a low curing shrinkage ratio and excellent moldability, but have the disadvantage that the molded article has low impact resistance and is brittle. Further, the curable (meth) acrylate resin has an excellent balance of heat resistance and moldability, physical properties of the molded product, and the like, but has a drawback in that the water absorption rate and the dimensional change rate thereby are large.
Among thermosetting plastics, silicone resin is superior in terms of heat resistance, weather resistance, and water resistance. Therefore, it is a material that solves the problems of the above plastics and is most likely to replace inorganic glass. is there. In particular, it is known that ladder-structured polyorganosilsesquioxane exhibits heat resistance not inferior to that of polyimide.
[0004]
As an example of such a polyorganosilsesquioxane, phenyltrichlorosilane is hydrolyzed in an organic solvent to phenyltrihydroxysilane, and the hydrolysis product is subjected to alkaline rearrangement and condensation catalyst in a solvent free of water. Intrinsic viscosity obtained by separating the vertical octaphenylsilsesquioxane and the vertical octaphenylsilsesquioxane obtained by heating and dehydrating polycondensation and again using the alkaline rearrangement and condensation catalyst. A method for producing a phenylsilsesquioxane polymer having a high intrinsic viscosity obtained by heat-polymerizing a phenylsiloxane prepolymer having a low viscosity or further using an alkaline rearrangement and condensation catalyst is disclosed in Japanese Patent Publication No. 40-15589, JP, Sho 50-139900 and J. Polymer Sci. Part C, No. 1, PP. 83-97 (1963).
[0005]
However, silicone resins including such polyorganosilsesquioxanes have a high flexibility of siloxane bonds, so that the crosslink density must be increased in order to develop the elastic modulus required for the structure. However, when the crosslinking density is increased, the curing shrinkage rate is remarkably increased, and the molded product becomes brittle. Moreover, since the residual stress due to curing shrinkage increases, it is extremely difficult to obtain a thick molded product. For these reasons, silicone resins having a high crosslinking density are limited to coating applications, and the present situation is that silicone rubber having a low crosslinking density is used for molding applications.
In order to solve this problem, a method of copolymerizing with an acrylic resin excellent in moldability has been proposed. For example, as a non-ladder type silicone resin, an acrylic polymer having an alkoxysilyl group in the side chain is used, and this is copolymerized with an alkoxysilane so that the acrylic polymer is an organic component and polysiloxane is an inorganic component. A technique for forming a body is disclosed in Journal of Chemical Society of Japan, 571-580 (1998) (Non-patent Document 1). However, since the silicone resin is originally not sufficiently compatible with the acrylate resin, optical properties such as light transmittance are often impaired even when there is no problem in mechanical strength.
[0006]
In addition, as a ladder-type silicone resin, a polyorganosilsesquide having a reactive functional group introduced into a part of the side chain for the purpose of copolymerization with an organic compound having a reactive functional group in order to solve the above-mentioned problems. Oxane is disclosed in JP-A-3-281616, JP-A-4-33936, JP-A-62-215944, and the like. Furthermore, a polyorganosilsesquioxane having a structure in which all or part of the hydrogen atoms of the silanol group contained in the polyorganosilsesquioxane is substituted with a triorganosilyl group is disclosed in JP-A-61-221232. These are disclosed in Kaihei 2-332356, JP-A-4-185541, JP-A-4-353521, EP0516144A1, etc., and most of these are reactions of molecular terminal silanol groups of ladder-type polyorganosilsesquioxane. In order to improve the storage stability by deactivating the properties, or to add a silylating agent for the purpose of controlling the molecular weight of polyorganosilsesquioxane to stop the polyorganosilsesquioxane polycondensation reaction. The main purpose is end sealing.
[0007]
The sealing method includes polyorganosilsesquioxane and triorganochlorosilane containing unreacted silanol groups once synthesized as disclosed in JP-A Nos. 61-212232 and 63-13446. In a method in which a dehydrochlorination reaction is carried out under an alkaline catalyst such as pyridine, a method in which a silanol group of polyorganosilsesquioxane is reacted with an organomonoisocyanatosilane, or JP-A-57-12057. As disclosed in JP-A-60-110726, which actively synthesizes a terminal hydroxy group-containing polyorganosilsesquioxane and performs a dealcoholization reaction with the triorganomonoalkoxysilane. Method and dehydrochlorination reaction with triorganomonochlorosilane There is a method described in 13728 JP, It is also known a method in which reacting a EP0516144A1 or terminal hydroxy polyorganosilsesquioxane as disclosed in JP-A-4-353521 discloses silsesquioxane and disilazane. Japanese Patent Application Laid-Open No. 7-70321 also describes a method in which a silanol group and an alkoxy group at the terminal of methylsilsesquioxane are reacted with hexamethyldisiloxane in an acid catalyst to undergo trimethylsilylation.
[0008]
Various methods are known to bind reactive functional groups as heterogeneous functional groups to side chains or terminals in the molecular structure of ladder-type polyorganosilsesquioxane as described above. All of them synthesized ladder-type polyorganosilsesquioxanes having hydroxyl groups (silanol groups) in the side chain or terminal, and chlorosilanes, alkoxysilanes, isocyanates having reactive functional groups with these hydroxyl groups. This is a method of reacting silanes, disilazanes and the like.
However, these ladder-type polyorganosilsesquioxanes have low compatibility with organic compounds having a functional group such as an acrylic resin, as in the case of the non-ladder-type silicone resins described above, and when both are copolymerized. Transparency decreases due to phase separation. Therefore, it is difficult to use a molded body composed of these compositions as a substitute for inorganic glass. In addition, in the structure of the synthesized polyorganosilsesquioxane, a small amount of silanol groups that did not contribute to polymerization remain and are included as defects and branched structures, resulting in deterioration of physical properties such as mechanical and heat resistance and storage. The problem that stability is impaired is also included.
The applicant of the present application has proposed a cage-type or ladder-type polyorganosilsesquioxane having a reactive functional group and a method for producing the same in JP-A-10-251407 (Patent Document 1).
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-251407
[Non-Patent Document 1]
The Chemical Society of Japan, 571-580 (1998)
[0010]
[Problems to be solved by the invention]
Accordingly, an object of the present invention is to provide a silicone resin composition capable of providing a silicone resin copolymer having excellent transparency. Another object is to provide a silicone resin composition comprising a silicone resin having good compatibility and an unsaturated compound copolymerizable. Another object of the present invention is to provide a silicone resin composition that does not contain a silanol group as a defect or a branched structure and has excellent storage stability. Another object of the present invention is to provide a silicone resin copolymer and a silicone resin copolymer molded article that are excellent in heat resistance, transparency, water resistance, mechanical properties, and the like, and that are suitably used for alternative applications of inorganic glass. There is. Furthermore, another object is to provide a silicone resin copolymer that is a three-dimensional crosslinked structure and a molded product thereof.
[0011]
[Means for Solving the Problems]
As a result of intensive studies in order to achieve the above-mentioned problems, the present inventors have succeeded in replacing inorganic glass by blending a silicone resin having a reactive functional group X at the molecular chain terminal and a reactive monomer at a specific ratio. The present inventors have found that a silicone resin copolymer and a molded product thereof that can be suitably used for applications can be provided.
[0012]
  That is, the present invention relates to the general formula (i),
  [RSiO_3/2]_n    (I)
(Wherein R represents an alkyl group having 1 to 6 carbon atoms or a phenyl group, and n represents the number of repetitions), and the main component is polyorganosilsesquioxane having a cage structure in the structural unit. A silicone resin, wherein at least a part of the siloxy group (SiO-) of the polyorganosilsesquioxane has the following general formula (1)
[Chemical formula 5]

Wherein X is (A) -R¹-OCO-CR²= CH₂, (B) -R¹-CR²= CH₂Or (C) -CH = CH₂Any one of the reactive functional groups represented by However, R¹Represents an alkylene group, an alkylidene group or a phenylene group, and R²Represents a hydrogen or alkyl group) and a silicone resin to which a triorganosilyl group is bonded, and -R in the molecule^Three-CR^Four= CH₂Or -CR^Four= CH₂(However, R^ThreeRepresents an alkylene group, an alkylidene group or an —OCO— group, and R^FourRepresents at least one unsaturated group represented by the following formula (a): an unsaturated compound other than the following general formula (a) capable of radical copolymerization with the silicone resin. The alicyclic unsaturated compound represented10-60: 10-70: 10-50It is the silicone resin composition characterized by mix | blending by the weight ratio.Here, the silicone resin is a disiloxane compound having a cage-like polyorganosilsesquioxane having a terminal closed in a cage shape and containing no silanol group and a reactive functional group represented by the following general formula (2) ( In the formula, X has the same meaning as in the general formula (1) above, and is prepared by heating and equilibrating reaction in an organic solvent in the presence of an alkaline rearrangement and condensation catalyst. 1. It has one or more reactive functional groups X.
[Chemical 6]

(In the formula, Z represents a divalent group represented by the following formula (a1) or (a2), and R represents hydrogen or a methyl group)
[Chemical 7]

[0013]
  Here, 1) the unsaturated group is at least one selected from the group consisting of acryloyl group, methacryloyl group, allyl group and vinyl group, and 2) the silicone resin has a cage structure and one end has a cage shape. And at least one selected from ladder-type structures closed to each other, or a mixture of at least one of these and a ladder-type structure, and 3) the silicone resin has a terminal closed in a bowl shape and does not contain silanol groups. Type polyorganosilsesquioxane and a disiloxane compound having a reactive functional group represented by the following general formula (2) (wherein X has the same meaning as in the above general formula (1)) in an organic solvent, alkaline Produced by heating and equilibrating reaction in the presence of rearrangement and condensation catalyst, per molecule1.5 or more on averageOr 4) the unsaturated compound contains a monomer or oligomer having 2 to 5 unsaturated groups in one molecule, and an average of 1.1 per molecule It is one of the preferable aspects of the silicone resin composition of this invention to have the above unsaturated group.
[Chemical 8]

[0014]
In addition, the present invention is a method for producing a silicone resin copolymer, wherein the silicone resin composition is radically copolymerized by heating or irradiation with energy rays. Furthermore, the present invention is a silicone resin copolymer obtained by radical copolymerization of the above silicone resin composition or a molded product thereof. Here, the silicone resin copolymer or molded product has a glass transition temperature and a 5% weight loss temperature both of 300 ° C. or higher, a total light transmittance of 85% or higher, and a water absorption of 1 It is preferably 0.0% or less.
[0015]
Hereinafter, the present invention will be specifically described.
The silicone resin composition of the present invention comprises a silicone resin and an unsaturated compound copolymerizable therewith as main components. The silicone resin copolymer of the present invention is obtained by radical copolymerization of this silicone resin composition. The molded article of the present invention can be obtained by molding and curing this silicone resin composition or molding this silicone resin copolymer. The silicone resin copolymer of the present invention is a crosslinked polymer, and in this case, a molding and curing method similar to that of a thermosetting resin can be adopted. Hereinafter, the silicone resin composition, the silicone resin copolymer, the production method thereof, and the molded body will be described in this order.
[0016]
The greatest feature of the silicone resin used in the present invention is that it contains a polyorganosilsesquioxane having a cage structure having a reactive functional group at the terminal (also called a cage polyorganosilsesquioxane). is there. As described above, the conventional silicone resin has low compatibility with an organic compound having a functional group such as an acrylic resin regardless of whether it is a ladder type or a non-ladder type, and a transparent molded body is obtained from these compositions. I couldn't. However, in the silicone resin of the present invention, a substituent such as an alkyl group or a phenyl group having high compatibility with an organic compound protrudes outside the cocoon, and conversely, a siloxane skeleton portion having low compatibility with the organic compound has an inside of the candy. Since a pseudo micelle structure is formed by being taken in, it can be mixed with an unsaturated compound such as an acrylic monomer or an oligomer at an arbitrary ratio.
[0017]
The silicone resin used in the present invention has a reactivity represented by the above general formula (1) on at least a part of SiO located at the molecular chain terminal of the polyorganosilsesquioxane represented by the general formula (i). It has a structural formula in which a triorganosilyl group having a functional group X is bonded, and usually has a polystyrene-equivalent weight average molecular weight Mw measured by GPC of 800 to 100,000, preferably 800 to 5,000. Is. In the general formula (1), X is a reactive functional group represented by the above (A) to (C). In the general formula (i), n represents the number of repetitions, and the average value is easy from the above Mw. Is calculated.
[0018]
Specific examples of the structural formula include a saddle-type structure shown in the following structural formula (3) and a ladder structure in which one end shown in the structural formula (4) is closed like a bowl. The silicone resin used in the present invention essentially comprises the above saddle structure, ladder structure, or both, and the ratio thereof is 50 wt% or more, preferably 70 wt% or more. As another silicone resin, there is a ladder structure represented by the structural formula (5), and the content ratio thereof is preferably less than 50 wt%. In each structural formula, a part, preferably all, of Y is a triorganosilyl group represented by the general formula (1).
[0019]
In the following description, the silicone resin used in the present invention may be represented by octaphenylsilsesquioxane as an example of polyorganosilsesquioxane, but the present invention is not limited thereto. .
The cage polyorganosilsesquioxane refers to those having in the molecule a cage structure such as structural formula (3) or structural formula (4).
[0020]
[Chemical 9]

[Chemical Formula 10]

Embedded image

(In the above formulas, at least a part of Y represents a triorganosilyl group represented by the general formula (1), and n represents the number of repetitions)
[0021]
Examples of the cage-type polyphenylsilsesquioxane which is closed in a cage shape and does not contain a silanol group are as described in the above-mentioned Japanese Patent Publication Nos. 40-15589 and 10-251407. In addition, a caged octaphenylsilsesquioxane obtained by hydrolyzing phenyltrichlorosilane in an organic solvent to form phenyltrihydroxysilane, heating using an alkaline rearrangement and condensation catalyst, and dehydrating polycondensation is preferably used. .
[0022]
The silicone resin used in the present invention is a method of reacting the above-described cage-type polyphenylsilsesquioxane or polyphenylsilsesquioxane containing the same with the disiloxane compound represented by the general formula (2). Can be obtained.
The reactive functional group X represented by the general formulas (1) and (2) is (A) -R¹-OCO-CR²= CH₂, (B) -R¹-CR²= CH₂Or (C) -CH = CH₂Any one of the groups represented by In addition, R in each formula¹Represents an alkylene group, an alkylidene group or a phenylene group, preferably a lower alkylene group having 1 to 6 carbon atoms, an alkylidene group or phenylene group having 1 to 6 carbon atoms. R²Represents hydrogen or an alkyl group, preferably hydrogen or a lower alkyl group having 1 to 6 carbon atoms (preferably a methyl group).
As a method for producing the disiloxane compound represented by the general formula (2), for example, dimethylchlorosilane and allyl (meth) acrylate are subjected to a hydrosilylation reaction using chloroplatinic acid as a catalyst, followed by hydrolysis and condensation polymerization. The reactive functional group X is -C_ThreeH₆-OCO-C (CH_Three) = CH₂That is, the disiloxane compound (A) can be easily obtained.
[0023]
As an alkaline rearrangement and condensation catalyst used for the reaction of polyphenylsilsesquioxane and the above disiloxane compound, cesium hydroxide used for the synthesis of a general ladder type or cage type polyphenylsilsesquioxane, Alkali metal hydroxides such as potassium hydroxide, sodium hydroxide and rubidium hydroxide, or ammonium hydroxide salts such as tetramethylammonium hydroxide, tetraethylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, tetra Tetraorganophosphonium compounds such as butyl phosphonium hydroxide and tetraethyl phosphonium hydroxide can be used.
[0024]
When alkali metal ions are not desired to remain in the main body such as for electronic materials, ammonium hydroxide salt or the like is selected. In addition, when the equilibration reaction is performed with the reaction temperature set to 130 ° C. or more for the purpose of shortening the reaction time, ammonium hydroxide salts and the like are decomposed, so alkali metal hydroxides are preferably used. Of these, cesium hydroxide having high reactivity is preferably used. The addition amount of the alkaline rearrangement and condensation catalyst is preferably used in the range of 0.01 to 20% by weight based on the weight of the disiloxane compound as a raw material. If the amount is 0.01% by weight or less, the yield of the target product is very small, and if it is 20% by weight or more, the side reaction in which the cage polyphenylsilsesquioxane alone becomes a high molecular weight proceeds predominantly, and the target product And separation and purification by reprecipitation of these by-products and catalyst are not easy.
[0025]
Examples of the organic solvent used in the above reaction include benzene, toluene, xylene, ethylene glycol dimethyl ether, N-methyl-2-pyrrolidinone, O-dichlorobenzene, diphenyl ether, 1,4-dioxane, acetone, methyl ethyl ketone, methyl isobutyl ketone, Examples include ethyl acetate, butyl acetate, ethyl acetoacetate, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, cyclohexane, benzonitrile, methyl phenyl ether, mesitine, durene, m-dimethoxybenzene, diphenyl, diphenyl chloride, and chlorobenzene. This is not a limitation.
Among the organic solvents, it is particularly preferable to select a nonpolar solvent such as benzene, toluene and xylene. The reason for this is that an equilibration reaction between a low-solubility octagonal silsesquioxane and a highly soluble disiloxane compound is carried out in an alkaline catalyst such as cesium hydroxide or tetramethylammonium hydroxide. In this case, since the cocoon-type octaphenylsilsesquioxane is dissolved in the solvent by silylation, the progress and end point of the reaction can be easily observed, and unreacted cocoon-type octaphenylsilsesquioxane can be observed. This is because separation of the sun and the target product by filtration becomes easy.
[0026]
The equilibration reaction of the polyphenylsilsesquioxane and the disiloxane compound under an alkali catalyst proceeds by the reaction mechanism of the above-described example. This is a ring-opening with a cage-type polyphenylsilsesquioxane alone, Or since it is in a competitive relationship with high molecular weight reaction, it is necessary to perform the former as preferentially as possible. In addition, since this reaction is basically an equilibration reaction, the weight average molecular weight Mw, yield and production rate of cage-type and ladder-type polyphenylsilsesquioxane containing a reactive functional group at the target end are high. It is preferably carried out under the conditions described below because it is naturally determined by the reaction temperature, reaction time, addition ratio of both raw materials, amount of alkali catalyst, and the like.
[0027]
That is, the weight ratio B / A of the addition amount A of the cage polyphenylsilsesquioxane and the addition amount B of the disiloxane compound is preferably selected from the range of 0.01 ≦ B / A ≦ 100, more preferably Is 0.01 ≦ B / A ≦ 10. When B / A is less than 0.01, the reactive functional group is hardly introduced, and the side reaction for increasing the molecular weight by itself is preferred. In addition, when B / A is 100, cage-type and ladder-type polyphenylsilsesquioxane containing a reactive functional group at the terminal are selectively synthesized with high yield, but unreacted diester is synthesized in the reaction system. A large amount of the siloxane compound remains and is not suitable because it is not easy to separate and purify by reprecipitation with the target product.
[0028]
In general, the above equilibration reaction tends to increase the solubility of the alkaline catalyst in the siloxane bond and increase the reaction rate and the reaction yield by performing the reaction under higher temperature conditions. As a result, the difference in reactivity of the polyphenylsilsesquioxane with respect to the alkaline catalyst is reduced, and the reaction selectivity is reduced. That is, a side reaction in which the cage polyphenylsilsesquioxane alone becomes a high molecular weight is induced. Therefore, the reaction temperature is preferably in the range of 60 to 200 ° C, more preferably in the range of 100 to 150 ° C. In addition, depending on the functional group species at the end of the disiloxane compound, for example, an acryloyl group or a methacryloyl group causes a self-polymerization reaction between functional groups if the reaction temperature is too high. It is necessary to take measures such as adding a polymerization inhibitor. The reaction time varies slightly depending on the reaction temperature and stirring efficiency, but is preferably 1 to 72 hours within the above temperature range in order to sufficiently achieve the target equilibration reaction.
The silicone resin obtained by the above production method is a mixture containing any one of a cage structure, a terminal cage ladder structure, and a ladder structure, or a mixture containing two or more kinds. In particular, 90 wt% or more consists of a saddle type structure or a terminal saddle type ladder type structure, or substantially or 90 wt% or more consists of both a saddle type structure and a terminal saddle type ladder type structure, A mixture of 50 wt% or more consisting of a saddle type structure, a terminal saddle type ladder type structure, or both and the other consisting of a ladder type structure is obtained. These reaction conditions can be easily understood from the above description or the descriptions in the above publications.
[0029]
The silicone resin used in the present invention is not limited to those obtained by the above-described production method, but is a polyorganosilsesquioxane mainly composed of polyorganosilsesquioxane having a cage structure in the structural unit, What is necessary is just to have the reactive functional group shown by General formula (1) in at least one part of the siloxy group (SiO-) of polyorgano silsesquioxane. It is preferable to have 1 to 4 reactive functional groups in one molecule, and in order to obtain a crosslinked structure copolymer, it is preferable to have 1.1 or more. In addition, since this silicone resin has good compatibility with many organic compounds, it can be mixed with an unsaturated compound having an unsaturated group such as acrylate, methacrylate, allyl compound, vinyl compound, etc. at an arbitrary ratio. It can be a composition.
[0030]
In the silicone resin composition of the present invention, the unsaturated compound used together with the silicone resin contains at least the alicyclic unsaturated compound represented by the general formula (a). Furthermore, it is advantageous that the unsaturated compound contains a non-alicyclic unsaturated compound together with the alicyclic unsaturated compound. Here, the non-alicyclic unsaturated compound is preferably a chain unsaturated compound or an aromatic unsaturated compound.
[0031]
The alicyclic unsaturated compound used as an essential component of the unsaturated compound is represented by the general formula (a).
Specific compounds include dicyclopentanyl diacrylate wherein Z is (a1) and R is hydrogen (= tricyclo [5.2.1.0^2,6Decanediacrylate), Z is (a2), and R is hydrogen pentacyclo [6.5.1.1^3,6. 0^2,7. 0^9,13] Pentadecanediacrylate.
[0032]
Non-alicyclic unsaturated compounds are represented by -R in the molecule.^Three-CR^Four= CH₂Or -CR^Four= CH₂And an unsaturated compound capable of radical copolymerization with the silicone resin. Where R^ThreeRepresents an alkylene group, an alkylidene group or an —OCO— group, and the alkylene group and alkylidene group are preferably a lower alkylene group having 1 to 6 carbon atoms and an alkylidene group. R^FourRepresents hydrogen or an alkyl group, preferably hydrogen or a methyl group. Preferable unsaturated groups include at least one selected from the group consisting of acryloxy group, methacryloxy group, allyl group and vinyl group.
[0033]
Non-alicyclic unsaturated compounds are roughly classified into reactive oligomers, which are polymers having a structural unit having about 2 to 20 repeating units, and reactive monomers having low molecular weight and low viscosity. Moreover, it divides roughly into the monofunctional unsaturated compound which has one unsaturated group, and the polyfunctional unsaturated compound which has two or more. In order to obtain a good three-dimensional cross-linked product, it is preferable to contain a very small amount of polyfunctional unsaturated compound (about 1% or less), but per molecule when the heat resistance and strength of the copolymer are expected. The average is 1.1 or more, preferably 1.5 or more. For this purpose, it is preferable to adjust the average number of functional groups by mixing and using a monofunctional unsaturated compound and a polyfunctional unsaturated compound having 2 to 5 unsaturated groups.
[0034]
Examples of reactive oligomers include epoxy acrylate, epoxidized oil acrylate, urethane acrylate, unsaturated polyester, polyester acrylate, polyether acrylate, vinyl acrylate, polyene / thiol, silicone acrylate, polybutadiene, and polystyrylethyl methacrylate. it can. These include monofunctional unsaturated compounds and polyfunctional unsaturated compounds.
[0035]
Reactive monofunctional monomers include styrene, vinyl acetate, N-vinylpyrrolidone, butyl acrylate, 2-ethylhexyl acrylate, n-hexyl acrylate, cyclohexyl acrylate, n-decyl acrylate, isobornyl acrylate, dicyclopentenyloxyethyl Examples include acrylate, phenoxyethyl acrylate, trifluoroethyl methacrylate, and the like.
As reactive polyfunctional monomers, unsaturated compounds other than general formula (a), such as tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, bisphenol A diglycidyl ether diacrylate, tetraethylene glycol diacrylate, Examples include hydroxypivalate neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, and the like.
[0036]
As the unsaturated compound used in the present invention, in addition to those exemplified above, for example, various reactive oligomers and monomers described in the book “UV Curing System” published by General Technology Center Co., Ltd. 1989 are used. However, this is not a limitation. These reactive oligomers and monomers may be used alone or in combination of two or more.
[0037]
The silicone resin composition of the present invention comprises a silicone resin and the unsaturated compound. Here, although all of the unsaturated compounds may be the alicyclic unsaturated compounds represented by the general formula (a), it is desirable to include the non-alicyclic unsaturated compounds. The weight blending ratio in this case is: silicone resin: non-alicyclic unsaturated compound: alicyclic unsaturated compound = 5-80: 0-80: 10-50, preferably 10-60: 10-70: 10 50. When the proportion of the silicone resin is large, the copolymer obtained has superior physical properties as a silicone resin, but some of its drawbacks are improved. The copolymer obtained when the proportion of the unsaturated compound is large, the physical properties of the unsaturated compound as a resin are dominant, but some of the drawbacks are improved.
[0038]
The silicone resin composition of this invention can obtain a silicone resin copolymer by radical copolymerizing this. Various additives can be added to the silicone resin composition of the present invention for the purpose of improving the physical properties of the silicone resin copolymer or promoting radical copolymerization. Examples of the additive that accelerates the reaction include a thermal polymerization initiator, a thermal polymerization accelerator, a photopolymerization initiator, a photoinitiation assistant, and a sharpening agent. When blending a photopolymerization initiator or a thermal polymerization initiator, the amount added is preferably in the range of 0.1 to 5 parts by weight with respect to a total of 100 parts by weight of the silicone resin and unsaturated compound. More preferably, it is in the range of 1 to 3 parts by weight. If this addition amount is less than 0.1 parts by weight, curing will be insufficient and the strength and rigidity of the resulting molded product will be low, while if it exceeds 5 parts by weight, problems such as coloring of the molded product may occur. is there.
[0039]
Various additives can be added to the silicone resin composition of the present invention within a range not departing from the object of the present invention. Various additives include organic / inorganic fillers, plasticizers, flame retardants, heat stabilizers, antioxidants, light stabilizers, UV absorbers, lubricants, antistatic agents, mold release agents, foaming agents, nucleating agents, colorants, Crosslinking agents, dispersion aids and the like can be exemplified, but are not limited thereto.
[0040]
A silicone resin copolymer can be obtained by radical copolymerization of the silicone resin composition of the present invention. Moreover, the molded body of a silicone resin copolymer can be obtained by radical copolymerizing the silicone resin composition in a predetermined shape. For radical copolymerization, heating or irradiation with an energy beam such as an electron beam or an ultraviolet ray is suitable.
[0041]
The silicone resin copolymer (molded product) of the present invention thus obtained has a glass transition temperature measured by a dynamic thermomechanical analyzer (DMA) or a thermomechanical analyzer (TMA), and a thermogravimetric analyzer. Any physical property value of 5% weight loss temperature measured by (TGA) is 300 ° C. or higher, total light transmittance (thickness 0.7 mm) is 85% or higher, and water absorption is 1% or lower. There can be. Therefore, since it has high heat resistance, high transparency, and high dimensional stability, it can be used for various applications in place of glass.
[0042]
【Example】
Examples of the present invention will be described below. In addition, the silicone resin used for the following Example was obtained by the method shown to the following synthesis example.
[0043]
Synthesis example 1
First, an example of production of cage-type octaphenylsilsesquioxane will be shown using the method described in Japanese Patent Publication No. 40-15959. Dissolve 105 g of phenyltrichlorosilane (0.5 mol) in 500 cc of benzene and shake with water until hydrolysis is complete. After washing the hydrolysis product with water, 16.6 cc (0.03 mol) of a commercially available 30% benzyltrimethylammonium hydroxide solution was added and the mixture was heated to reflux for 4 hours. The whole was then cooled and left for about 96 hours. After this time, the resulting slurry was again heated to reflux for 24 hours, then cooled and filtered. Thus, about 75 g of cage-type octaphenylsilsesquioxane was obtained. When the infrared absorption spectrum analysis was measured, Si-C₆H_FiveAbsorption attributed to 1595cm^-1And 1430cm^-1Further, the absorption attributed to the antisymmetric stretching vibration of Si—O—Si is 1135 cm.^-1The absorption attributed to Si—OH is 3400 cm.^-1Not observed.²⁹When Si-MAS NMR was measured, a sharp signal of Si nuclei in the cage octaphenylsilsesquioxane was observed at -77 ppm. As described in J. Polymer Sci. Part A Vol. 33, 55-62 (1995), Si nuclei bonded to hydroxyl groups were not observed at -70 ppm and -62 ppm.
[0044]
Next, 8 parts by weight of the above-mentioned octaphenylsilsesquioxane and 8 parts by weight of 1,3-bis (3-methacryloxypropyl) -1,1,3,3-tetramethyldisiloxane in the reaction vessel 32 parts by weight of toluene, 0.16 part by weight of cesium hydroxide and 0.03 part by weight of a polymerization inhibitor (methoquinone manufactured by Seiko Chemical Co., Ltd.) were charged, and this mixture was vigorously stirred at the reflux temperature and heated for 7 hours. At the time of charging, the white powder of vertical octaphenylsilsesquioxane did not dissolve in toluene, but gradually dissolved as the reaction proceeded, and all dissolved after 7 hours. The solution was cooled to room temperature, insoluble unreacted cesium hydroxide was removed by filtration, and then poured into 500 parts by weight of methanol to precipitate silylated polyphenylsilsesquioxane having a methacryloyl group at the terminal. The precipitated product was separated by filtration and then vacuum dried to obtain 14 parts by weight of a single-structured caged silylated polyphenylsilsesquioxane (silicone resin) having a methacryloyl group at the end of a white solid.
[0045]
When the weight average molecular weight Mw in terms of polystyrene was measured by GPC, it was about 1500. When infrared absorption spectrum analysis was measured by the KBr tablet method, Si-C₆H_FiveAbsorption attributed to 1595cm^-1And 1430cm^-1Further, the absorption attributed to the antisymmetric stretching vibration of Si—O—Si is 1135 cm.^-1And 1020cm^-1It was found that few oligomers (silicone resins) have a ladder structure, and many of them have a cage structure. Moreover, the absorption attributed to Si-OH is 3400 cm.^-1Not observed.¹H-NMR and¹³When C-MAS NMR was measured, an H nucleus and a C nucleus in a 3-methacryloxypropyldimethylsilyl group and a phenyl group were observed. Also,²⁹When Si-MAS NMR was measured, an Si nucleus in the 3-methacryloxypropyldimethylsilyl group was observed at 10.9 ppm and an Si nucleus in the cage octaphenylsilsesquioxane skeleton was observed at 79.2 ppm at an intensity ratio of 2: 8. Si in raw material 1,1,3,3 tetramethyl-1,3-di (3-methacryloxypropyl) disiloxane which is not removed by reprecipitation operation to 7.7 ppm and is slightly contained in the oligomer Nuclei were also observed. In addition, signals of -70 ppm and -62 ppm of Si nuclei bonded to hydroxyl groups were not observed.
[0046]
Synthesis example 2
First, an example of producing a ladder-type phenyl polysiloxane prepolymer having no silanol using the method described in Japanese Patent Publication No. 40-15989 is shown. About 500 parts of phenyltrichlorosilane dissolved in 500 parts of toluene was slowly added to 2000 parts of water with stirring. The acid layer was then separated, and the resin layer in the form of a toluene solution was azeotropically distilled to remove residual water and HCl. Thereafter, about 0.078% of KOH was added to the calculated amount of the phenylpolysiloxane having no hydroxy group, and the toluene solution was refluxed for 9 hours with stirring to obtain a ladder type phenylpolysiloxane prepolymer having no silanol. The resulting syrup-like phenylpolysiloxane prepolymer consisting of about 50.3% of the toluene solution has the formula C₆H_FiveSiO_1.5It consisted of a circulation unit. Separation of the solid phenyl prepolymer was performed by diluting this toluene solution of phenylpolysiloxane with about 1.5 times the weight of mineral spirit (boiling point: about 156-196 ° C., KB value: about 37). The resulting slurry was stirred vigorously for about 10 minutes, then filtered off, and the resulting solid was air dried for about 16 hours and then dried at 150 ° C. for 4 hours.
When the infrared absorption spectrum analysis of the prepolymer thus obtained was measured, the absorption attributed to Si-C6H5 was 1595 cm.^-1And 1430cm^-1Further, the absorption attributed to the antisymmetric stretching vibration of Si—O—Si indicating that the prepolymer has a ladder structure is 1135 cm.^-1And 1045cm^-1The absorption attributed to Si—OH is 3400 cm.^-1Not observed.²⁹When Si-MASNMR was measured, a signal indicating that the line width due to Si nuclei in the ladder-type phenylpolysiloxane prepolymer was somewhat widened was observed at -77 ppm, and signals of -70 ppm and -62 ppm of Si nuclei bonded to hydroxyl groups were observed. Was not.
[0047]
Next, 10 parts by weight of ladder-type phenylpolysiloxane prepolymer (polystyrene converted weight average molecular weight Mw 4000 by GPC) produced in the above and having no silanol group in 50 parts by weight of xylene and 1,3-bis (3-methacrylic). (Roxypropyl) -1,1,3,3-tetramethyldisiloxane 50 parts by weight is dissolved, 5 parts by weight of potassium hydroxide and a polymerization inhibitor (methoquinone manufactured by Seiko Chemical Co., Ltd.) 0.05 parts by weight are added, The mixture was stirred at reflux temperature and heated for 10 hours. The solution was cooled to room temperature, insoluble unreacted cesium hydroxide was removed by filtration, and then poured into 1000 parts by weight of n-hexane to precipitate silylated polyphenylsilsesquioxane having a methacryloyl group at the terminal. It was. The precipitated product was filtered off and vacuum dried to obtain 12 parts by weight of a ladder type silicone resin having a methacryloyl group at the end of a white solid.
It was about 5000 when the weight average molecular weight Mw of polystyrene conversion was measured by GPC. When the infrared absorption spectrum analysis was measured, Si-C₆H_FiveAbsorption attributed to 1595cm^-1And 1430cm^-1Further, the absorption attributed to the antisymmetric stretching vibration of Si—O—Si indicating that the polymer has a ladder structure is 1135 cm.^-1And 1045cm^-1The absorption attributed to Si—OH is 3400 cm.^-1Not observed.¹When H-NMR was measured, a 3-methacryloxypropyldimethylsilyl group and an H nucleus in the phenyl group were observed.
The silicone resin obtained in Synthesis Example 1 was mainly composed of a cage type body, and the silicone resin obtained in Synthesis Example 2 was almost 100% of a ladder type body.
[0048]
Example 1
Vertically silylated polyphenylsilsesquioxane (silicone resin) having a methacryloyl group obtained in Synthesis Example 1: 50 parts by weight, trimethylolpropane triacrylate: 40 parts by weight, dicyclopentanyl diacrylate: 10 parts by weight As a photopolymerization initiator, 1 part of 1-hydroxycyclohexyl phenyl ketone was mixed to obtain a transparent silicone resin composition.
Next, it is cast (cast) to a thickness of 1.0 mm using a roll coater, and 1000 mJ / cm using a 30 W / cm high-pressure mercury lamp.²A sheet-like silicone resin molded body having a predetermined thickness was obtained by curing with the accumulated exposure amount.
[0049]
Examples 2-5 and Comparative Examples 1-7
A resin molded body was obtained in the same manner as in Example 1 except that the composition was changed to the ratio shown in Table 1. Table 2 summarizes the physical property values of the obtained molded body.
[0050]
The abbreviations are as follows.
A: Compound obtained in Synthesis Example 1 (silicone resin)
B: Compound (silicone resin) obtained in Synthesis Example 2
C: Trimethylolpropane triacrylate
D: Dicyclopentanyl diacrylate (Kyoeisha Chemical Co., Ltd. light acrylate DCP-A: In general formula (a), Z is (a2) and R is H)
E: 1-hydroxycyclohexyl phenyl ketone (polymerization initiator)
[0051]
[Table 1]

[0052]
[Table 2]

[0053]
1) Breaking strength, tensile breaking elongation (reference standard JIS K 7162): Test piece test speed 5.0 mm / min, distance between chucks 50 mm
2) Flexural modulus (based on reference standard JIS K 7171): Test speed 0.3 mm / min, distance between fulcrums 12 mm, fulcrum radius 0.5 mm, indenter radius 1.5 mm
3) Glass transition temperature: Dynamic thermomechanical analysis (DMA), heating rate 5 ° C./min, distance between chucks 10 mm
4) 5% weight loss temperature (Td^Five): Measured with a thermogravimetric analyzer (TGA) at a heating rate of 10 ° C / min in a nitrogen atmosphere
5) Total light transmittance (based on reference standard JIS K 7361-1): Sample thickness 0.7 mm
6) Water absorption rate (reference standard JIS K 7209 compliant): Sample predrying condition 50 ° C., 24 hours
7) Moldability: The resin composition was cured on the base material under the conditions of the above-described example, and a 2 mm thick sheet-like cured product (molded body) was formed on the base material. The ease of removal when removing the molded body from the substrate was evaluated according to the following criteria.
○: Very cheap to remove
Δ: There is no problem with normal removal, but about 1 in 10 breaks
×: Easy to break and difficult to remove
8) Thermal deformability: A molded body having a thickness of 0.4 mm (100 × 100 mm) was placed in a hot air circulation oven at 160 ° C. for 1 hour, and the presence or absence of warpage and swell was visually evaluated.
〇: Sled or swell is not allowed
△: Sled was recognized
X: A wave-like swell was observed
[0054]
【The invention's effect】
The composition of the present invention provides a resin copolymer having excellent heat resistance and visible light transmittance. Moreover, since the molded object of this invention has a low water absorption, and has high dimensional stability and high moldability, it can be used for various uses instead of glass.

Claims (11)

The following general formula (i),
[RSiO _3/2 ] _n (i)
(However, R represents an alkyl group having 1 to 6 carbon atoms and a phenyl group, and n represents the number of repetitions.) At least a part of the siloxy group (SiO-) of the polyorganosilsesquioxane represented by General formula (1)

(Wherein, X is ^{(A) -R 1 -OCO-CR} 2 = CH 2, the reactive functional groups represented by ^{(B) -R 1 -CR 2 =} CH 2 or (C) -CH = CH ₂ either. However, R ¹ is an alkylene group, an alkylidene group or a phenylene group, R ² is silicone resin triorganosilyl group is bonded, represented by a hydrogen or an alkyl group), wherein The silicone resin has a cage-like end and a cage-type polyorganosilsesquioxane containing no silanol group and the following general formula (2)

(Wherein X has the same meaning as in general formula (1))
The disiloxane compound having a reactive functional group represented by the formula is produced by heating and equilibrating reaction in an organic solvent in the presence of an alkaline rearrangement and condensation catalyst. A silicone resin mainly composed of polyorganosilsesquioxane having an average of 1.1 or more reactive functional groups X per molecule,
For the silicone resin , the following general formula (a)

(In the formula, Z represents one of the groups represented by the following formula (a1) or (a2), and R represents hydrogen or a methyl group)

An alicyclic unsaturated compound represented by the formula: —R ³ —CR ⁴ ═CH ₂ or —CR ⁴ ═CH ₂ (wherein R ³ represents an alkylene group, an alkylidene group or an —OCO— group; R ⁴ represents hydrogen or an alkyl group), and includes a non-alicyclic unsaturated compound capable of radical copolymerization with the silicone resin. The silicone resin composition characterized by mix | blending the weight ratio of a saturated compound: alicyclic unsaturated compound in the ratio used as 10-60: 10-70: 10-50 . The silicone resin composition according to claim 1, wherein the unsaturated group is at least one selected from the group consisting of an acryloyl group, a methacryloyl group, an allyl group, and a vinyl group. The silicone resin composition according to any one of claims 1 and 2, wherein the silicone resin is mainly composed of at least one selected from a saddle type structure and a ladder type structure having one end closed in a saddle shape. object. The silicone resin composition according to any one of claims 1 to 3, wherein the silicone resin is a mixture containing a ladder structure in a range of 50 wt% or less. The silicone resin composition according to any one of claims 1 to 4, wherein the silicone resin has an average of 1.5 or more reactive functional groups X per molecule . The non-alicyclic unsaturated compound contains a monomer or oligomer having 2 to 5 unsaturated groups in one molecule and has an average of 1.1 or more unsaturated groups per molecule. The silicone resin composition in any one of -5. A method for producing a silicone resin copolymer, wherein the silicone resin composition according to claim 1 is radically copolymerized by heating or irradiation with energy rays. A silicone resin copolymer obtained by radical copolymerization of the silicone resin composition according to claim 1. 9. The silicone resin copolymer according to claim 8, wherein both of the glass transition temperature and the 5% weight reduction temperature are 300 ° C. or higher, the total light transmittance is 85% or higher, and the water absorption is 1.0% or lower. . The molded object obtained by shape-hardening the silicone resin composition in any one of Claims 1-6. A molded article formed by molding the silicone resin copolymer according to claim 8 or 9.