JP4227680B2 - Liquid crystal film and manufacturing method thereof - Google Patents

Description

【００２２】
【化２】

【００２３】
本発明の光硬化性液晶性組成物は、以上説明した非液晶性化合物を少なくとも１種含有するものである。当該組成物に占める上記化合物の割合としては、目的とする光硬化型液晶性組成物の液晶性、配向性、硬化性に支障が無い限り特に限定されるものではないが、通常０．０１〜４０重量％、好ましくは０．１〜２０重量％、さらに好ましくは１〜１０重量％の範囲である。０．０１重量％より少ない場合には、本発明の効果である配向基板または配向膜と光硬化後の液晶層との密着性に対して十分な改善が得られない恐れがある。また４０重量％を越える場合には、後述する液晶物質の種類によっては液晶性を示さなくなる恐れがある。さらには液晶相とアイソトロピック相との相分離が起こる恐れもある。
【００２４】
次いで液晶物質について説明する。
液晶物質としては、特に限定されるものではなく、例えばネマチック液晶、カイラルネマチック液晶、スメクチック液晶、カイラルスメクチック液晶、ディスコチックネマチック液晶、カイラルディスコチックネマチック液晶、ディスコチックカラムナー液晶、カイラルディスコチックカラムナー液晶などの液晶性を呈する低分子液晶および／または高分子液晶が挙げられる。なお本発明でいう液晶物質とは、１種単独の液晶化合物および少なくとも２種以上の液晶化合物からなる液晶性組成物を意味するものである。また液晶化合物としては、例えば二量体、三量体乃至数量体のいわゆるオリゴマーや重合体物をも本発明では包含する。また液晶物質中に、例えばアクリル基、メタクリル基、ビニル基、アリル基、フタルイミド基などの光重合性官能基を有するか否かについても特に制限されるものでもない。さらに光重合性官能基を有する液晶物質を用いる場合および／または後述にて説明する任意成分である非液晶性の光重合性化合物を配合する場合、本発明の光硬化性液晶性組成物に占める光重合性官能基としては、光重合性官能基等量として通常１０ｍｍｏｌ／ｇ以下、好ましくは０．０１〜５ｍｍｏｌ／ｇ、さらに好ましくは０．１〜３ｍｍｏｌ／ｇとなるように上述にて説明した一般式１で表される非液晶性化合物との組成比を調整することが望ましい。
【００２５】
上記低分子液晶として具体的には、液晶性が既知である例えばビフェニル誘導体、フェニルベンゾエート誘導体、スチルベン誘導体など広く知られているカラミティック（棒状）液晶化合物、トリフェニレン誘導体、トルクセン誘導体などのディスコティック（円盤状）液晶化合物等を基本骨格としたものが挙げられる。
また高分子液晶としては、例えば液晶性ポリエステルに代表される縮合系高分子液晶、ビニル重合系高分子液晶、ポリシロキサン系高分子液晶、エポキシ系高分子液晶などを例示として挙げることができる。
また液晶物質としては、ライオトロピック性またはサーモトロピック性のどちらを用いることができるが、サーモトロピック性を示すものがフィルム化プロセスなどの面でより好適である。
以上説明した、一般式１で表される非液晶性化合物および液晶物質とから少なくとも本発明の光硬化型液晶性組成物を得ることができる。
【００２６】
また当該組成物としては、最終的に得られる組成物が、光硬化性および液晶性を示すものであれば、必要に応じて任意成分として一般式１で表される非液晶性化合物以外の非液晶性を示す光重合性物質、光反応開始剤などを適宜配合することができる。
光重合性物質としては、光照射を行うことにより重合・硬化しうるアクリル基、メタクリル基、ビニル基、アリル基、フタルイミド基などの官能基を有する非液晶性化合物または非液晶性組成物を意味し、その構造・組成比などについては特に制限されるものではない。
光重合性物質を配合する場合、本発明の組成物に対して通常５０重量％以下、好ましくは４０重量％以下、さらに好ましくは５〜３０重量％で配合することができる。
【００２７】
また光反応開始剤としては、１種または少なくとも２種以上の当該開始剤を本発明の組成物に配合することができる。光反応開始剤としては、例えばベンジル、ベンゾイルエーテル、ベンゾインイソブチルエーテル、ベンゾインイソプロピルエーテル、ベンゾフェノン、ベンゾイル安息香酸、ベンゾイル安息香酸メチル、４−ベンゾイル−４’−メチルジフェニルサルファイド、ベンジルメチルケタール、ジメチルアミノメチルベンゾエート、２−ｎ−ブトキシエチル−４−ジメチルアミノベンゾエート、ｐ−ジメチルアミノ安息香酸イソアミル、３，３’−ジメチル−４−メトキシベンゾフェノン、メチロベンゾイルフォーメート、２−メチル−１−（４−（メチルチオ）フェニル）−２−モルフォリノプロパン−１−オン、２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタン−１−オン、１−（４−ドデシルフェニル）−２−ヒドロキシ−２−メチルプロパン−１−オン、１−ヒドロキシシクロヘキシルフェニルケトン、２−ヒドロキシ−２−メチル−１−フェニルプロパン−１−オン、１−（４−イソプロピルフェニル）−２−ヒドロキシ−２−メチルプロパン−１−オン、２−クロロチオキサントン、２，４−ジエチルチオキサントン２，４−ジイソプロピルチオキサントン、２，４−ジメチルチオキサントン、イソプロピルチオキサントン、１−クロロ−４−プロポキシチオキサントンなどが例示される。
【００２８】
上記の如き光反応開始剤の配合量は、本発明の組成物に対して通常０．０１〜２０重量％、好ましくは０．１〜１０重量％、さらに好ましくは０．５〜５重量％配合することができる。
また本発明の光硬化型液晶性組成物には、光反応開始剤の他に本発明の効果を損なわない範囲でさらに増感剤等を配合することもできる。
なお本発明の光硬化型液晶性組成物は、上記の如き光反応開始剤を全く用いずにＥＢ（電子ビーム）を照射することにより硬化することが可能な当該組成物も包含するものである。
【００２９】
以上説明した光硬化型液晶性組成物は、配向基板または配向膜と当該組成物から形成される光硬化後の液晶層との密着性を改良できるという、これまでの光硬化型液晶では得ることが困難であった効果を有するものである。したがって本発明の光硬化型液晶性組成物を用いて液晶フィルムを作成した際には、上記密着性に優れた当該フィルムを得ることができる。
【００３０】
本発明の液晶フィルムは、支持フィルムまたは配向膜を有する支持フィルムに配し、熱処理、光照射工程を踏んで得ることが望ましい。
支持フィルムとしては、液晶配向用フィルムとして利用できるフィルムであれば特に限定されるものではないが、例えばポリイミド、ポリアミドイミド、ポリアミド、ポリエーテルイミド、ポリエーテルエーテルケトン、ポリエーテルケトン、ポレケトンサルファイド、ポリエーテルスルフォン、ポリスルフォン、ポリフェニレンサルファイド、ポリフェニレンオキサイド、ポリエチレンテレフタレート、ポリブチレンテレフタレート、ポリエチレンナフタレート、ポリアセタール、ポリカーボネート、ポリアリレート、アクリル樹脂、ポリビニルアルコール、ポリプロピレン、セルロース、トリアセチルセルロース、表面鹸化処理を施したトリアセチルセルロース、エポキシ樹脂、フェノール樹脂などのプラスチックフィルムおよび当該フィルムに直接ラビング処理を施したラビングプラスチックフィルムが挙げられる。
【００３１】
上記支持フィルムには、必要に応じて一軸または二軸延伸操作を適宜加えても良い。また支持フィルムとしては、親水化処理や疎水化処理などの表面処理を施したものであっても構わない。また上記支持フィルムは１種単独、必要に応じて２種以上のフィルムを積層して用いることもできる。さらに支持フィルムとしては、表面にスリット状の溝をつけたアルミ、鉄、銅などの金属基板、表面をスリット状にエッチング加工したアルカリガラス、ホウ珪酸ガラス、フリントガラスなどのガラス基板などを用いることもできる。
【００３２】
上記支持フィルム上に設けられる配向膜の種類としては、ポリイミド、ポリアミド、ポリビニルアルコール等を例示することができる。さらに配向膜としては、支持フィルム上に酸化珪素を斜め蒸着して得られる蒸着膜であっても構わない。
【００３３】
以上説明した支持フィルム、配向膜はいずれも本発明に使用可能なものではあるが、本発明の効果がより顕著に期待できるのは光硬化型液晶性組成物が接する支持フィルム表面または配向膜表面にヒドロキシル基を有するものを使用した場合である。このような支持フィルム、配向膜としては、ヒドロキシル基を有するポリイミド、ポリアミド、アクリル樹脂、フェノール樹脂、セルロース、表面鹸化処理を施したトリアセチルセルロースフィルム、ポリビニルアルコール等を例示することができる。また配向膜としては、ゼラチンやキチン質等を原料として得られるものであってもよい。本発明では、上記支持フィルム中でもトリアセチルセルロースフィルムをフィルム成形後に表面をアルカリ処理などの手法により鹸化したフィルムが特に好ましい。
【００３４】
本発明の光硬化型液晶性組成物層が接する表面にヒドロキシル基を有する支持フィルムまたは配向膜を用いた場合、上述にて説明した当該組成物を構成する非液晶性化合物のイソシアネート基部分が、後述する加熱工程などによって当該ヒドロキシル基と反応することにより、光硬化型液晶性組成物層と支持フィルム表面または配向膜表面とを化学結合を介して強固に固定化することが可能となる。さらに一般式１で表される非液晶性化合物中には、光重合性官能基である（メタ）アクリロイル基を有しているため、当該組成物に対して硬化のために光照射を行った際、当該組成物に光重合性官能基を有する液晶物質または必要に応じ非液晶性を示す光重合性物質などが含まれていた場合には当該物質との光架橋反応も起こることによって、硬化後の液晶層と支持フィルムまたは配向膜との密着性をより著しく改善することができる。
【００３５】
次いで上記の如き支持フィルム上または配向膜上に光硬化型液晶性組成物を配する方法について説明する。当該方法としては、光硬化型液晶性組成物の溶液を調整して行う溶液塗布を好適な方法として本発明では推奨する。ここで当該組成物を溶解することができる溶剤としては、本発明の光硬化型液晶性組成物の特性を損なうことなく溶解することができ、塗布した際に支持フィルムまたは配向膜の配向能を侵すことがなく、さらには乾燥によって溶剤成分を除去できるものであれば特に限定されない。なお上述において説明した一般式１で表される非液晶性化合物中のイソシアネート基を保護せずに用いる際には、当該化合物の効果を損なうことがないような溶剤を選定する必要がある。このような溶剤としては光硬化型液晶性組成物の組成比、液晶物質の種類などによって異なるため一概には言えないが、例えばベンゼン、トルエン、キシレン、ｎ−ブチルベンゼン、ジエチルベンゼン、テトラリン等の炭化水素系溶剤、メトキシベンゼン、１，２−ジメトキシベンゼン、ジエチレングリコールジメチルエーテル等のエーテル系溶剤、アセトン、メチルエチルケトン、メチルイソブチルケトン、シクロヘキサノン等のケトン系溶剤、酢酸エチル、エチレングリコールモノメチルエーテルアセテート、プロピレンエチレングリコールモノメチルエーテルアセテート、γ−ブチロラクトン等のエステル系溶剤、２−ピロリドン、Ｎ−メチル−２−ピロリドン、ジメチルホルムアミド、ジメチルアセトアミド等のアミド系溶剤、クロロホルム、ジクロロメタン、四塩化炭素、ジクロロエタン、テトラクロロエタン、トリトリクロロエチレン、テトラクロロエチレン、クロロベンゼン、オルソジクロロベンゼン等のハロゲン系溶剤、および上記溶剤の少なくとも２種以上混合した混合溶剤といったヒドロキシル基や活性メチレン基などのイソシアネート基と反応しうる官能基を持たないものが例示される。但し、一般式１で表される非液晶性化合物中のイソシアネート基を保護した状態で当該工程に供する際にはこの限りではなく、例えばｔｅｒｔ−ブチルアルコール、グリセリン、エチレングリコール、トリエチレングリコール、エチレングリコールモノメチルエーテル、エチルセルソルブ、ブチルセルソルブ等のアルコール類や、フェノール、パラクロロフェノール等のフェノール類および上記溶剤の少なくとも２種以上混合した混合溶剤であっても本発明では用いることができる。
【００３６】
溶液の濃度は、光硬化型液晶性組成物の溶解性や最終的に目的とする液晶フィルムの膜厚に依存するため一概にはいえないが、通常１〜６０重量％、好ましくは３〜４０重量％の範囲である。
【００３７】
さらに上記溶液には、界面活性剤を添加することもできる。界面活性剤としては、例えばイミダゾリン、第四級アンモニウム塩、アルキルアミンオキサイド、ポリアミン誘導体等の陽イオン系界面活性剤、ポリオキシエチレン−ポリオキシプロピレン縮合物、第一級あるいは第二級アルコールエトキシレート、アルキルフェノールエトキシレート、ポリエチレングリコールおよびそのエステル、ラウリル硫酸ナトリウム、ラウリル硫酸アンモニウム、ラウリル硫酸アミン類、アルキル置換芳香族スルホン酸塩、アルキルリン酸塩、脂肪族または芳香族スルホン酸ホルマリン縮合物等の陰イオン系界面活性剤、ラウリルアミドプロピルベタイン、ラウリルアミノ酢酸ベタイン等の両性系界面活性剤、ポリエチレングリコール脂肪酸エステル類、ポリオキシエチレンアルキルアミン等の非イオン系界面活性剤、パーフルオロアルキルスルホン酸塩、パーフルオロアルキルカルボン酸塩、パーフルオロアルキルエチレンオキシド付加物、パーフルオロアルキルトリメチルアンモニウム塩、パーフルオロアルキル基・親水性基含有オリゴマー、パーフルオロアルキル・親油基含有オリゴマーパーフルオロアルキル基含有ウレタン等のフッ素系界面活性剤などを用いることができる。界面活性剤の添加量は、界面活性剤の種類や光硬化型液晶性組成物、溶剤、あるいは塗布すべき基板フィルムにもよるが、通常該光硬化型液晶性組成物に対して通常１０ｐｐｍ〜１０％、好ましくは１００ｐｐｍ〜５％、さらに好ましくは０．１％〜１％の範囲である。
【００３８】
溶液塗布法としては、スピンコート法、ロールコート法、プリント法、浸漬引き上げ法、カーテンコート法（ダイコート法）などを採用することができる。
塗布後、溶剤を乾燥除去し、支持フィルム上または配向膜上に膜厚の均一な光硬化型液晶性組成物層を形成させる。溶剤の乾燥除去条件は特に限定されず、溶剤がおおむね除去でき、当該液晶性組成物層が流動したり、流れ落ちたりさえしなければ良い。通常、室温での風乾、ホットプレートでの乾燥、乾燥炉での乾燥、温風や熱風の吹き付けなどを利用して溶剤を除去する。
【００３９】
溶剤を乾燥除去した後の該光硬化型液晶性組成物層の膜厚は、当該組成物の種類や液晶フィルムの用途により一概には言えないが、例えば本発明の液晶フィルムを視野角改良フィルム、色補償フィルム、位相差板といった光学補償フィルムとして用いる場合には、通常０．０１μｍ〜１００μｍ、好ましくは０．１μｍ〜２０μｍ、さらに好ましくは０．２〜１０μｍの範囲であることが望ましい。
【００４０】
塗布・乾燥工程の段階は、まず支持フィルム上に均一に光硬化型液晶性組成物層を形成させることが目的であるが、該光硬化型液晶性組成物の種類によっては、溶剤が除去される温度でサーモトロピックに、または溶剤が除去される過程においてライオトロピックに配向が完了している場合もあり得る。しかしながら、通常、液晶を配向させるために、またはより均一な配向状態を得るために、次の熱処理工程を行うことが本発明においては望ましい。
【００４１】
熱処理は、光硬化型液晶性組成物の液晶転移点以上の温度で行う。すなわち該光硬化型液晶性組成物の液晶状態で配向させるか、または、一旦液晶相を呈する温度範囲よりもさらに高温の等方性液体状態にした後、液晶相を呈する温度範囲にまで温度を下げることにより行う。液晶相を呈する温度範囲内で温度を変化させる方法も採用することができる。例えば、同じネマチック相を呈する温度範囲内で、高温で熱処理し、液晶を概ね配向させた後、温度を下げることによって液晶配向の秩序度を増す方法、またはネマチック相を呈する温度で熱処理しネマチック配向させた後、温度を下げてスメクチック相などのより高次の液晶相で配向させる方法なども本発明では用いることができる。
【００４２】
熱処理温度は、光硬化型液晶性組成物の組成比および当該組成物を構成する液晶物質の種類によって異なるため一概には言えないが、通常４０℃〜２２０℃、好ましくは５０℃〜１８０℃、さらに好ましくは６０℃〜１６０℃の範囲で行われる。
【００４３】
また液晶が十分な配向をするために要する時間は、光硬化型液晶性組成物の種類および当該組成物を構成する液晶物質の種類によって異なるため一概には言えないが、通常５秒〜２時間、好ましくは１０秒〜４０分、さらに好ましくは２０秒〜２０分の範囲である。５秒より短い場合、該液晶性組成物層の温度が所定温度まで上がりきらず配向不十分となる恐れがある。また、２時間より長い場合には、生産性が低下するので望ましくない。
【００４４】
熱処理終了後、光照射を行うことによって、液晶状態において形成した配向状態を固定化した液晶フィルムを得ることができる。
光照射に用いられる光の波長は特に限定されず、電子線、紫外線、可視光線、赤外線（熱線）を必要に応じて用いることができる。通常、紫外光または可視光線が用いられ、波長１５０〜５００ｎｍ、好ましくは２５０〜４５０、さらに好ましくは３００〜４００ｎｍの照射光が好適に用いられる。
【００４５】
また光源としては、低圧水銀ランプ（殺菌ランプ、蛍光ケミカルランプ、ブラックライト）、高圧放電ランプ（高圧水銀ランプ、メタルハライドランプ）、ショートアーク放電ランプ（超高圧水銀ランプ、キセノンランプ、水銀キセノンランプ）などが挙げられる。なかでもメタルハライドランプやキセノンランプ、高圧水銀ランプ灯からの紫外光、可視光が最も一般的であり、本発明にも好適に用いることができる。なお上記光源と被照射体（熱処理後の光硬化型液晶性組成物層）との間に、フィルター等を設け、特定の波長領域を露遮することによって照射光源の波長領域を限定して用いても構わない。
照射する光量は、光硬化型液晶性組成物の組成比、液晶物質の種類や組成比、光反応開始剤の添加量などによって異なるため一概には言えないが、通常２〜５０００ｍＪ／ｃｍ² 、好ましくは１０〜３０００ｍＪ／ｃｍ² 、さらに好ましくは１００〜２０００ｍＪ／ｃｍ² の範囲である。
【００４６】
光照射を行う温度については、光硬化型液晶性組成物の液晶相挙動や流動性、硬化性などに強く影響されるため一概には言えないが、通常０〜２００℃、好ましくは２０〜１８０℃、さらに好ましくは２５〜１６０℃の範囲である。
但し、例えば室温付近の低温領域にてスメクチック相や結晶相といった高次相を有し、さらにその上の温度領域にネマチック相の温度領域を有するような光硬化型液晶性組成物を、ネチマック相の状態で光硬化により固定化する場合には、高次相−ネマチック相の相転移点以上の温度で光照射を行うことによって均一なネマチック相を固定化できる場合もあり得る。また熱処理後、冷却することによってネマチック相が過冷却により固定化された場合においても、液晶相がガラス化されて流動性に乏しく、光硬化速度が遅い場合がある。このような光硬化型液晶性組成物を用いた際には、再加熱して流動性を与えた後に光照射を行うことによって、より均一な配向状態でもって固定化された液晶フィルムを得ることができる場合がある。
【００４７】
また光照射は、数回に分けて行っても良く、たとえば加熱下で一度光照射を行ってある程度光硬化型液晶性組成物を硬化させた後、冷却し、さらに光照射を行う等、より光反応の反応率を向上させる方法を採用することもできる。
さらに本発明では、光照射の後に熱処理を行い未反応部位をさらに反応させる、いわゆるエージングを行っても構わない。
いずれにせよ光照射を行う温度は、用いられる光硬化型液晶性組成物の種類によって適宜調整する必要がある。
【００４８】
また光照射雰囲気は、光硬化型液晶性組成物の硬化性や光反応開始剤の種類、照射光の強度、照射温度等の様々な要因により一概に言えない。例えば被硬化物（熱処理後の光硬化型液晶性組成物層）が、空気中の酸素により硬化阻害を受けやすい場合には、被硬化物または支持フィルム等の光照射される部材が空気中の酸素により酸化されて着色などの問題が生じる可能性がある。また照射光源からの強い光を空気中で照射することによって、オゾンの発生等が起こり得る可能性もある。このような場合には、例えば窒素ガス下において光照射を行う方法を採用する。また熱処理後の光硬化型液晶性組成物の配向状態を損なわれることがない範囲において、適当なカバーフィルム、例えばポリエチレンテレフタレートフィルム、ポリエチレンナフタレートフィルム、ポリフェニレンサルファイドフィルム、ポリアリレートフィルム、ポリカーボネートフィルム、ポリビニルアルコールフィルム、ポリ酢酸ビニルフィルム、ポリエチレンフィルム、ポリプロピレンフィルム、ポリ塩化ビニルフィルム、ポリ塩化ビニリデンフィルム、ポリアミドフィルム、ポリイミドフィルム、ポリエチレン−酢酸共押し出しフィルム等で覆うことによって酸素遮断を行っても良い。
【００４９】
以上の如くして得られる本発明の液晶フィルムは、上述した光硬化型液晶性組成物の性質故に光硬化後の液晶層と支持フィルムとの層間密着性に非常に優れるものである。また所望の配向状態を均一に固定化することができることから、その配向状態に応じて、例えば液晶表示素子に用いられる光学機能性フィルム、具体的には視野角改良フィルム、色補償フィルム、複屈折型位相差補償フィルム、ヘッドアップディスプレイなどに使用される旋光子フィルムとして用いることもできる。上記の如き用途に本発明の液晶フィルムを用いた際には、光学性能、信頼性、取り扱い性、力学強度の面で非常に好適なフィルムとなり得るなど、その工業的利用価値は極めて高い。
【００５０】
【実施例】
以下に実施例について述べるが、本発明はこれらに限定されるものではない。（参考例１ アクリル基含有イソシアネート化合物の合成）
トリレンジイソシアネート（東京化成（株）製試薬）を蒸留精製後、１０．０ｇ（５７．４ｍｍｏｌ）フラスコに量り取り、モレキュラーシーブ４Ａにて脱水処理したジクロロメタン５０ｍｌで希釈した。これに反応触媒として４−ジメチルアミノピリジン０．０７０ｇ（０．５７ｍｍｏｌ）を加え、窒素雰囲気下で攪拌しながら、さらに６−ヒドロキシ２−エチルヘキシルアクリレート１２．３ｇ（５７．４ｍｍｏｌ）のジクロロメタン溶液を室温で滴下した。この後、フラスコを６０度のオイルバスに浸け加温し、リフラックス状態で６時間反応させた。その後、反応液をロータリーエバポレーターにより濃縮し、若干の溶媒を含む粘性のある褐色の液体生成物２４．２ｇを得た（反応生成物１）。
【００５１】
得られた生成物を岩塩板に薄く塗布し、透過ＩＲ分光測定を日本分光製ＦＴ／ＩＲ−７０００にて行ったところ、イソシアネート基に特徴的に見られる波数２２００〜２３００ｃｍ^-1に鋭い吸収ピーク、イソシアネート基が反応して生じたカルバミド酸エステル結合に由来する３３００〜３６００ｃｍ^-1のややブロードな吸収ピークと１６９０〜１７８０ｃｍ^-1の強い吸収ピークが見られた。
【００５２】
生成物の組成を定量するためにＧＰＣ分析を行った。溶出溶媒として、脱水処理したテトラヒドロフランを用い、高速ＧＰＣ用充填カラム（ＴＳＫｇｅｌ Ｇ−１０００ＨＸＬ）を装着した東ソー製ＧＰＣ分析装置ＣＣＰ＆８０００（ＣＰ−８０００、ＣＯ−８０００、ＲＩ−８０００）を用いて分析を行った。また測定は反応生成物１のＴＨＦ希釈試料を用いて行った。試料から検出されたピークは、未反応のトリレンジイソシアネート、トリレンジイソシアネートと６−ヒドロキシ２−エチルヘキシルアクリレートの１：１付加物（化合物２）および、トリレンジイソシアネート１ｍｏｌに対して６−ヒドロキシ２−エチルヘキシルアクリレートが２ｍｏｌ反応した化合物（化合物３）であった。ピークの積分値比から、反応液試料はモル比してトリレンジイソシアネートが１４．７％、化合物２が８４．７％、化合物３が０．６％であることがわかった。
【００５３】
（参考例２）
５００ｍｌ三角フラスコ中で水酸化ナトリウム（和光純薬）と超純水を用いて０．９８規定水酸化ナトリウム水溶液４５０ｍｌを調整した。この水溶液を深さ６ｃｍ、３５ｃｍ角のテフロン製バットに移し、大気中の二酸化炭素の影響をなくすためバット上部にガラス板をのせた状態でホットプレート上で５０℃に加温した。ここに、３０ｃｍ角に切り出したトリアセチルセルロースフィルム（フジタックＵＶＤ−８０ 富士写真フィルム社製）を浸漬し、５分間鹸化処理を行った。処理後、フィルムを純水シャワーでアルカリ分をあらかた洗い流した後、中性リン酸塩標準緩衝液（和光純薬製、２５℃におけるｐＨ６．８６）に十分に浸した後、再度純水洗浄を行った。得られたフィルムを乾燥エアーガンにより水分をあらかた除去した後、８０℃のオーブン中でさらに１０分間乾燥させた。
原料トリアセチルセルロースフィルムと得られた鹸化処理トリアセチルセルロースフィルムの純水接触角を、協和界面科学社製接触角測定装置ＣＡ−Ａにて測定した結果を表１に示す。
【００５４】
【表１】

【００５５】
（実施例１）
メチルヒドロキノンのビス（４−（８−アクリロイロキシオクチルオキシ）安息香酸）エステル（液晶物質１）４ｇと、参考例１にて合成した反応生成物１を０．２ｇ（液晶物質１に対して５重量％、反応生成物１中の有効成分たる非液晶性化合物２の重量にして約４．７重量％）とからなる光硬化型液晶性組成物１を調整した。
次いで当該組成物１を１５．８ｇのｍ−キシレンに溶解させ、２１重量％溶液を調製した。これにフッ素系界面活性剤（Ｓ−３８３ アサヒガラス社製）を０．０２１ｇ（組成物１に対して０．５重量％）、光反応開始剤（イルガキュアー３６９ チバガイギー社製）を０．０８４ｇ（組成物１に対して２重量％）添加し光硬化型液晶性組成物溶液を調整した。
【００５６】
次いで参考例２で得られた表面鹸化処理トリアセチルセルロースフィルムをポリアミド繊維にてラビング処理した。ラビング処理面に０．５μｍ径テフロンフィルターにより濾過した光硬化型液晶性組成物溶液をディップコート法によって塗布し、５０℃に設定したオーブン中で５分間乾燥後、さらに８０℃に設定したオーブン中、窒素雰囲気下で１５分間熱処理を行った。
熱処理後、オーブン中に設置した高圧水銀灯により、３６５ｎｍの光の積算量で１２００ｍＪの光を照射して光硬化を行い、液晶フィルム１（構成：表面鹸化処理トリアセチルセルロースフィルム／液晶フィルム１）を得た。
液晶フィルム１の液晶表面は、鉛筆硬度にしてＨＢ程度まで硬化していた。
【００５７】
次いで液晶フィルム１をバックライト上でクロスニコル配置の２枚の偏光板の間に配置して観察したところ、ラビング方向に正の複屈折を持つ、均一に配向したネマチック液晶相が固定化されていることが判明した。
フィルム１の膜厚を触針式膜厚計により測定したところ１．７μｍであった。また、このサンプルを偏光顕微鏡下で、ベレックコンペンセーターを用いて複屈折を測定したところ、ラビング方向に軸を有しており、リターデーションは１８７ｎｍであることが判明した。
次いで液晶フィルム１とトリアセチルセルロースフィルム間の密着性を評価するために、塗膜基盤目試験（ＪＩＳ規格 Ｋ５４００）を行ったところ、全ての升目で一切剥離が生じなかった。
【００５８】
（比較例１）
液晶物質１を含み、反応生成物１を含まない液晶溶液を実施例１と同様に調製し、実施例１と同様に操作を行い比較用フィルム１を作成した。
得られた比較用フィルム１の配向状態および硬化度は実施例１で得られた液晶フィルム１とほぼ同程度であった。
また比較用フィルム１の膜厚は触針式測定で１．６μｍ、リターデーションは１８４ｎｍであった。
比較用フィルム１を実施例１と同様に基盤目試験を行ったところ、全ての升目で剥がれが生じ、また剥離の際の抵抗感も一切なかった。
【００５９】
（参考例３ アクリル基含有イソシアネート化合物の合成）
イソホロンジイソシアネート（東京化成（株）製試薬）を蒸留精製した後、２０．０ｇ（９０ｍｍｏｌ）フラスコに量り取り、２回蒸留したテトラヒドロフラン８０ｍｌで希釈した。これに反応触媒としてジブチル錫ジアセテート０．３ｇ（１．８ｍｍｏｌ）を加え、窒素雰囲気下でフラスコを６０度のオイルバスに浸け加温した。この溶液の加温状態に攪拌下２−ヒドロキシエチルアクリレート１２．５３ｇ（１０８ｍｍｏｌ）の２０ｍｌテトラヒドロフラン溶液を１５分かけて滴下した。滴下終了後、反応液をリフラックス温度まで加温し、攪拌下２時間反応を行った。その後、反応液をロータリーエパポレーターにより濃縮し、若干の溶媒を含む粘性のある液体生成物３３．２ｇを得た（反応生成物４）。
【００６０】
得られた生成物の組成を定量するため、参考例１と同様の方法によって当該生成物のＧＰＣ分析を行った。試料から検出されたピークは、イソホロンジイソシアネート、ヒドロキシエチルアクリレートの１：１付加物（化合物５）、イソホロンジイソシアネート１ｍｏｌに対してヒドロキシエチルアクリレートが２ｍｏｌ反応した化合物（化合物６）であった。ピークの積分値比から、反応液試料はモル比にして化合物５が８０．５％、化合物６が１９．５％であることが判明した。この結果は、イソホロンジイソシアネートのモル数に対して１．２当量加えられたヒドロキシエチルアクリレートのうち、ほぼ１当量がイソホロンジイソシアネートの反応しやすい一方のイソシアネート基と反応し、残りの０．２当量分がもう片側のイソシアネート基とも反応したという当量関係ともほぼ一致するものであった。
【００６１】
（参考例４ ヘキサキス（６−（９−アクリロイロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセン（液晶物質２）の合成）
ヘキサアセトキシトルクセン１０．０ｇ（１２．５ｍｍｏｌ）と、６−（９−ベンジロキシノニルオキシ）−２−ナフタレンカルボン酸３６．８ｇ（８７．６ｍｍｏｌ）をフラスコに量り取り、フラスコを窒素雰囲気下２７０℃に加熱したオイルバスに浸け加熱した。１５分後、カルボン酸成分の融解とともに反応が始まり、酢酸が生成し始めた。フラスコに枝管をつけ、流出する酢酸をコンデンサーにより冷却し系外へ除去しながら攪拌を行い、その温度で２時間反応させた。さらに、フラスコ内部に３０ｍｌ／分で窒素フローをしながら２時間、５０ｍｌ／分のフローで２時間反応を行った。反応終了後、生成物は反応温度で液晶性・流動性を示しており、この状態でフラスコから内容物を抜き出すと、生成物として室温で淡黄色の固体３８．４ｇ（回収率９３％）が得られた。
【００６２】
生成物の１Ｈ−ＮＭＲ測定（２７０ＭＨｚ、クロロホルム−ｄ溶媒）から、生成物はヘキサキス（６−（９−ベンジロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセンを主成分として９５％以上含むことがわかった。生成物をメトラー製ホットステージ上で加熱しながら偏光顕微鏡下で観察したところ、２００度ではディスコチックネマチック液晶相、アイソトロピック転移温度は３００度以上、また２００度から１０℃／分で室温まで冷却しても結晶相や高次の液晶相は観察されなかった。
【００６３】
このヘキサキス（６−（９−ベンジロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセンの全量を酢酸エチル１６０ｍｌとエチルアルコール４０ｍｌの混合溶媒に溶解し、さらにパラジウム−カーボン（エヌ・イー・ケムキャット（株）製、パラジウム５％担持、Ｋタイプ）３ｇを加え、５００ｍｌ耐圧容器に移した。容器内を水素ガスで置換し、さらに水素を５ｋｇ／ｃｍ² の圧力になるまで加圧した。この状態で、室温で１２時間反応させ、脱ベンジル化を行った。反応終了後、反応溶液をセライト濾過し、ロータリーエバポレーターにより濃縮すると、淡黄色の結晶が得られた。これをメタノールで洗浄後、真空乾燥機で６０℃、０．５ｍｍＨｇにて１２時間乾燥を行い、生成物であるヘキサキス（６−（９−ヒドロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセン３０．５ｇ（９８％）を得た。生成物の１Ｈ−ＮＭＲ測定（２７０ＭＨｚ、ＤＭＳＯ−ｄ６溶媒）では、ベンジル基に由来する４．５ｐｍｍ付近のピークが完全に消失しており、脱ベンジル化がほぼ定量的に行われたことを確認した。
【００６４】
得られたヘキサキス（６−（９−ヒドロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセンの全量をテトラヒドロフラン１５０ｍｌに溶解し、蒸留精製したトリエチルアミン１０．０ｇ（９８．９ｍｍｏｌ）を加えて０℃に冷却、攪拌しながらアクリル酸クロライド（東京化成製試薬）８．９５ｇ（９８．９ｍｍｏｌ）のテトラヒドロフラン溶液を徐々に滴下した。３０分後フラスコを４０℃に加温し、さらに２時間反応させた。反応液を酢酸エチル３００ｍｌで希釈し、１規定塩酸水２００ｍｌを加えて分液操作を行った。さらに、有機層を１規定塩酸水１００ｍｌで２回、飽和炭酸水素ナトリウム水溶液で２回洗浄した。洗浄後の有機層に無水硫酸マグネシウム２０ｇを加えて良く攪拌することにより水分除去を行い、硫酸マグネシウムを櫨別除去した後、溶液をロータリーエバポレーターにより濃縮すると、粘躊な液晶が得られた。これをメタノール３００ｍｌに分散し、−２０℃に冷却しながら激しく攪拌すると徐々に結晶化し、濾過、メタノール洗浄すると白色結晶が得られた。真空乾燥後の重量は３１．３ｇ（収率９０％）であった。生成物の１Ｈ−ＮＭＲ測定（２７０ＭＨｚ、クロロホルム−ｄ溶媒）を行ったところ、ヘキサキス（６−（９−アクリロイロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセン（液晶物質２）を主成分として含むことがわかった。
【００６５】
生成物をメトラー製ホットステージ上で加熱しながら偏光顕微鏡下で観察したころ、１２０度でディスコチックネマチック液晶相を示し、２００度付近でアクリル基の重合が始まるまでアイソトロピック転移は起こらなかった。また１２０度から１０℃／分で室温まで冷却すると、８５℃付近で高次の液晶相が、５０℃付近で結晶相が観察された。
生成物をシリカゲルカラムクロマトグラフィーにより２回精製した後、再結晶によりさらに精製し、液晶物質２を白色結晶の状態で得た。生成物のＧＰＣ分析を、溶出溶媒として脱水処理したテトラヒドロフランを用い、高速ＧＰＣ用充填カラム（ＴＳＫｇｅｌ Ｇ−１０００ＨＸＬ）を装着した東ソー製ＧＰＣ分析装置ＣＣＰ＆８０００（ＣＰ−８０００、ＣＯ−８０００、ＲＩ−８０００）により行ったところ、液晶物質２に由来するピークの近傍に１％未満のサブピークが見られた。よって液晶物質２の精製後の純度は９９％以上であることがわかった。
【００６６】
（参考例５）
ポリビニルアルコール（クラレ社製 ＭＰ−２０３）１０ｇを水／２−プロパノールの重量比で１／１の混合溶媒９５ｇに溶解し、５重量％の溶液を調製した。
トリアセチルセルロースフィルム（フジタックＵＶＤ−８０ 富士写真フィルム社製）の片側表面をゼラチン処理により接着性を高めた後、このゼラチン処理面にポリビニルアルコール溶液をスピンコート法により塗布した。塗布後、塗布に用いたガラス基板ごと６０℃のホットプレート上で３０分乾燥させた後、さらに１００℃に設定したオーブン中で１０分乾燥させた。トリアセチルセルロースフィルム上に形成されたポリビニルアルコール膜はゼラチン層を介して支持トリアセチルセルロースフィルムと良く密着しており、ポリビニルアルコール面はセロテープ等では容易に剥離されなかった。また、乾燥後のポリビニルアルコール層のみを一部削り落としたサンプルを触針式膜厚計で測定したところ、ポリビニルアルコール層の膜厚は１．１μｍであった。
【００６７】
（実施例２）
参考例４で得られたヘキサキス（６−（９−アクリロイロキシノニルオキシ）−２−ナフタレンカルボキシ）トルクセン（液晶物質２）４ｇと、参考例３にて合成した反応生成物４を０．３ｇ（液晶物質２に対して７．５重量％、反応生成物４中の有効成分たる非液晶性化合物５の重量にして約５．６％）とからなる光硬化型液晶性組成物２を調整した。
次いで当該組成物を１５．７ｇの２−ブトキシエチルアセテートに溶解し、２１．５重量％溶液を調製した。これに、非液晶性の光重合性物質としてテトラエチレングリコールジアクリレート０．２１５ｇ（組成物２に対して５重量％）、フッ素系界面活性剤０．０３２３ｇ（組成物２に対して０．７５重量％）、光反応開始剤（イルガキュア−９０７ チバガイギー社製）０．２５８ｇ（組成物２に対して６重量％）添加し、光硬化型液晶性組成物溶液を調製した。
【００６８】
この溶液を、０．４５μｍ径テフロンフィルターにより濾過した後、次いで参考例５で得られたポリビニルアルコール配向膜にポリアミド繊維にてラビング処理を施した。ラビング処理面に０．４５μｍ径テフロンフィルターで濾過した光硬化型液晶性組成物溶液をパーコート法により塗布し、５０℃に設定したホットプレート上で６０分間乾燥後、１６５℃に設定したオーブン中で１０分間熱処理を行った。熱処理後、オーブンから取りだして、窒素雰囲気下、高圧水銀灯により３６５ｎｍの光の積算量で８００ｍＪの光を照射して光硬化を行った。さらに液晶層面に、表面をシリコン処理したポリエチレンテレフタレートフィルムをラミネートし、当該フィルムを通して１２００ｍＪの光照射を再度行い液晶フィルム２（構成：トリアセチルセルロースフィルム／ポリビニルアルコール配向膜／液晶フィルム２）を得た。
【００６９】
得られた液晶フィルム２の液晶表面は、鉛筆硬度にして２Ｈ程度まで硬化しており、当該フィルム２をバックライト上でクロスニコル配置の２枚の偏光板の間に配置して観察すると、ディスコチック液晶のハイブリッド配向構造が得られていることが判明した。またフィルム２は面内にリターデーションを有しており、その方向はラビング方向に一致していた。リターデーションは−５５ｎｍであり、均一に配向した負の複屈折を示すディスコチックネマチック液晶相が固定化されていることが判明した。
液晶フィルム２の膜厚を触針式膜厚計により測定したところ、２．２μｍであった。
液晶フィルム２の密着性を評価するべく、実施例１と同様な方法によって基盤目試験を行ったところ、全ての升目で一切剥離が生じなかった。
【００７０】
（比較例２）
反応生成物４を加えない以外、全て実施例２と同様な操作を行い比較用フィルム２を作成した。
比較用フィルム２を用いて実施例１と同様に基盤目試験を行うべく準備をしたところ、既に剥がれが生じ、当該試験を行うことができなかった。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photocurable liquid crystal composition and a liquid crystal film formed from the composition.
[0002]
[Prior art]
Light-curing liquid crystalline substances have increased durability by light diffusion display using polymer network liquid crystal, active elements such as polymer-stabilized ferroelectric liquid crystal display, photopolymerization-induced liquid crystal phase separation film, or photocuring. In recent years, applications to various optical films have been reported, and the demand thereof has increased, and attention has been paid to optical properties and physical properties thereof (JL Fergason et.al., SID Dig.Tech.Paper, 16). 68 (1985), PS Drzaic, J. Appl. Phys., 60, 2142 (1986), T. Fujisawa et al., 1989 Japan Display, 690 (1989), etc.).
Here, the optical film is a film that expresses a specific optical characteristic based on the liquid crystalline substance layer after orientation-forming / photocuring the photocurable liquid crystalline substance.
[0003]
When using a photocurable liquid crystalline material for an optical film or the like, there is often a problem of adhesion between the photocured liquid crystalline material layer and peripheral members such as a support film, a liquid crystal alignment film, and a protective layer.
As one method of eliminating this adhesiveness, a substituent that can react with the photopolymerizable group at the same time when the photocurable liquid crystalline compound is photocrosslinked by itself is preliminarily chemically bonded to the liquid crystal alignment film. There is a method of introducing the above (Japanese Patent Laid-Open No. 8-338913 etc.). In this method, the adhesion with the liquid crystalline substance layer after photocuring is improved by using as the alignment film a compound having an acrylic group that becomes a photoreactive group through an ester bond in polyvinyl alcohol. To do.
[0004]
However, in this method, it is necessary to introduce a compound having an acrylic group into polyvinyl alcohol by an ester bond. For example, when aligning a photocurable liquid crystalline compound on an existing film or alignment film having no photoreactive group. Is not applicable. In addition, there is a limit to the amount of the compound that can be introduced into polyvinyl alcohol, and the density of photoreactive groups in the vicinity of the interface that can react with the liquid crystalline substance layer because the photoreactive groups are uniformly present in the alignment film. You ca n’t raise. Furthermore, by introducing a photoreactive group into the liquid crystal alignment film, there are various problems such as not only the photocurable liquid crystalline compound but also the liquid crystal alignment film requiring attention such as light shielding during storage. It was.
[0005]
[Problems to be solved by the invention]
  The present invention solves the above-mentioned problems. Specifically, without introducing a photoreactive group into the alignment film, there is no substantial adverse effect on the liquid crystal alignment formation in the alignment film, and light irradiation after alignment is performed. High adhesion to alignment filmLiquid crystal film and manufacturing method thereofIs to provide.
[0006]
[Means for Solving the Problems]
  The first of the present invention isPhotopolymerizationA layer of a photocurable liquid crystalline composition comprising a liquid crystalline substance and a non-liquid crystalline compound comprising a (meth) acrylate compound having one or more isocyanate groupsOn the surfaceIt is a liquid crystal film formed from a support film having a hydroxyl group or a composite disposed on an alignment film.
  In the second aspect of the present invention, a support film or alignment film having a hydroxyl group on the surface is used.PhotopolymerizationApplying a photocurable liquid crystalline composition containing a liquid crystalline substance and a non-liquid crystalline compound comprising a (meth) acrylate compound having one or more isocyanate groups, aligning the liquid crystal, and then irradiating with light. It is the manufacturing method of the liquid crystal film characterized.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail.
The photocurable liquid crystalline composition of the present invention essentially contains at least one (meth) acrylate compound having at least one isocyanate group as a non-liquid crystalline compound together with a liquid crystal substance.
In the above, (meth) acrylate means acrylate or / and methacrylate.
[0008]
The (meth) acrylate compound having the isocyanate group can be represented by the general formula (1).
General formula (1)
(CH₂= C (-R) -COO-X-)_m-Y- (ZN = C = O)_n
X and Z are sites having a single bond or a divalent functional group, Y is a (m + n) -valent site, m and n are integers of 1 or more, and R is a hydrogen atom or a methyl group.
[0009]
As the non-liquid crystalline compound, a compound having a carbamic acid ester bond at X in the general formula (1) can be preferably used. Specifically, the compound can be obtained by reacting a (meth) acrylate having a hydroxyl group with a polyisocyanate having at least two isocyanate groups in an excess of isocyanate groups with respect to the hydroxyl groups. That is, the (meth) acrylate having a hydroxyl group in an amount less than the isocyanate group equivalent of the polyisocyanate introduces a (meth) acryl group via a carbamic acid ester bond while leaving the isocyanate group partially in the molecule. The said compound can be obtained by employ | adopting a method.
[0010]
When the said method is employ | adopted, the mixture of the compound with which the (meth) acrylate compound which has 0 to n hydroxyl groups of n isocyanate groups of polyisocyanate reacted can be obtained. The mixture has a non-liquid crystalline compound represented by the general formula (1), specifically having 1 to (n-1) hydroxyl groups of n isocyanate groups of polyisocyanate (meth). The acrylate reacts to include a non-liquid crystalline compound having (n-1) to 1 unreacted isocyanate group in the molecule.
[0011]
The (meth) acrylate having a hydroxyl group is not particularly limited as long as it is a compound having a (meth) acryl group and a hydroxyl group in one molecule. Examples of the compound include hydroxyalkyl acrylates such as hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxybutyl acrylate, and 6-hydroxy 2-ethylhexyl acrylate, and glycol monoacrylates such as diethylene glycol monoacrylate, dipropylene glycol monoacrylate, and triethylene glycol monoacrylate. Examples include acrylates, phenols such as 4- (2-acryloyloxyethoxy) phenol, 6- (2-acryloyloxyethoxy) -2-naphthol, and hydroxyalkyl (meth) acrylate is particularly preferable.
[0012]
In the (meth) acrylate having a hydroxyl group, the equivalent of the hydroxyl group is usually 0.3 to 0.8 equivalent, preferably 0.4 to 0.7 equivalent, more preferably with respect to the isocyanate group equivalent of the polyisocyanate described later. Can be used to obtain the non-liquid crystalline compound used in the present invention. Here, in the case of 0.3 equivalent or less, the amount of unreacted polyisocyanate compound increases, and in the case of exceeding 0.8 equivalent, all of the isocyanate groups reacted with the (meth) acrylate compound having a hydroxyl group. The ratio of the compound increases, and in either case, the yield of the non-liquid crystalline compound having a (meth) acryl group and a hydroxyl group in one target molecule is undesirably lowered.
[0013]
Next, the polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule. In the present invention, diisocyanate can be mentioned as a suitable example. Examples of the diisocyanate include 1,6-hexane diisocyanate, 1,4-diisocyanatobenzene, tolylene diisocyanate, cyclohexane diisocyanate, dicyclopentadienyl diisocyanate, and isophorone diisocyanate.
As the isocyanate group in the polyisocyanate, a compound protected by a protecting group capable of regenerating the isocyanate group by an operation such as heating can be used. By introducing a protective group, an isocyanate group that is highly active and unstable to moisture can be stabilized, which is desirable in terms of a usable period (pot life).
[0014]
A protecting group and a method for introducing the protecting group are not particularly limited as long as a method known in the art can be adopted and an isocyanate group can be regenerated. For example, compounds such as hydrocyanic acid, boric acid, acidic sulfites, aliphatic amines, aromatic amines, tertiary alcohols, phenols, mercaptans, enols, oximes, lactams, β-ketoesters, malonic acid esters are used. Thus, a protecting group can be introduced.
[0015]
The method for synthesizing the non-liquid crystalline compound used in the present invention is not particularly limited, and can be synthesized by employing a method known in the art. For example, according to a general synthesis method of carbamic acid ester (described in SR Sandler, W. Karo, “Organic Functional Group Preparations”, vol. 2, Academic (1971), Chapters 10 to 11) This is done by dropping a (meth) acrylate having a hydroxyl group into a solution containing an isocyanate, or dropping a polyisocyanate into a solution of a (meth) acrylate having a hydroxyl group, or mixing both at the same time. The method of dripping the (meth) acrylate which has a hydroxyl group in the solution containing this can be employ | adopted as a preferable method.
[0016]
Examples of the solvent that can be used in the above reaction include hydrocarbon solvents such as hexane, cyclohexane, benzene, toluene, xylene, ethylbenzene, diethylbenzene, cumene, butylbenzene, and tetralin, dichloromethane, chloroform, tetrachloroethane, chlorobenzene, and dibenzene. Halogen solvents such as chlorobenzene, ether solvents such as THF, dioxane, diethyl ether, anisole, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, butyl acetate, 2-methoxypropanol acetate, γ- Examples thereof include ester solvents such as butyrolactone and amide solvents having no active hydrogen such as N-methylpyrrolidone and N, N-dimethylacetamide. These solvents can be used alone or in combination of two or more. The type and amount of the solvent are not particularly limited as long as the target product is obtained. It is also possible to carry out the reaction without solvent without using any of the above solvents.
[0017]
In the above reaction, hydrogen chloride, boron trifluoride ether complex, aluminum chloride, dialkyltin dichloride, dialkyltin diacetate, pyridine, 4-dimethylaminopyridine, N-methylpiperidine, sodium acetate or the like may be used as a catalyst. it can. Of these, dialkyltin diacetate can be cited as a suitable catalyst. The addition amount of the catalyst is usually in the range of 0.1 mmol to 0.1 mol, preferably 0.5 mmol to 50 mmol, more preferably 1 mmol to 20 mmol with respect to 1 mol of polyisocyanate.
[0018]
Although the target product can be obtained even at room temperature, it is usually desirable to set the reaction temperature to about 40 to 100 ° C., preferably about 50 to 80 ° C. in order to obtain the target product more efficiently.
The reaction time is usually 10 minutes to 30 hours, preferably 20 minutes to 10 hours, more preferably 30 minutes to 5 hours.
[0019]
In the above reaction, for example, when a compound having two isocyanate groups having different reactivities such as isophorone diisocyanate is used, a catalyst is added in advance to a solution containing the isocyanate and heated, and the compound has a hydroxyl group under stirring (meta ) By adopting a method such as gradually dropping the acrylate compound, it is possible to selectively react the isocyanate group having the higher reactivity and leave the isocyanate group having the lower reactivity unreacted. In any case, the reaction conditions and the like are appropriately adjusted depending on the properties of the polyisocyanate and hydroxyl group-containing (meth) acrylate used for the reaction.
[0020]
After completion of the reaction, the target product can be separated and purified by techniques such as distillation, recrystallization, reprecipitation, column chromatography, etc. in some cases, but the product is a highly active compound having an isocyanate group. Therefore, most purification means are difficult. Therefore, when the product is used as the non-liquid crystalline compound to be used in the present invention, it may be used in a state where the solvent is removed from the reaction solution without purification or in the state of the reaction solvent.
Specific examples of the non-liquid crystalline compound described above include the following compounds, but the present invention is not limited thereto.
[0021]
[Chemical 1]

[0022]
[Chemical formula 2]

[0023]
The photocurable liquid crystalline composition of the present invention contains at least one non-liquid crystalline compound described above. The proportion of the compound in the composition is not particularly limited as long as it does not hinder the liquid crystallinity, orientation, and curability of the target photocurable liquid crystalline composition, but is usually 0.01 to It is in the range of 40% by weight, preferably 0.1-20% by weight, more preferably 1-10% by weight. When it is less than 0.01% by weight, there is a possibility that sufficient improvement cannot be obtained with respect to the adhesion between the alignment substrate or alignment film and the photocured liquid crystal layer, which is an effect of the present invention. On the other hand, if it exceeds 40% by weight, liquid crystal properties may not be exhibited depending on the type of liquid crystal substance described later. Further, phase separation between the liquid crystal phase and the isotropic phase may occur.
[0024]
Next, the liquid crystal substance will be described.
The liquid crystal substance is not particularly limited, and examples thereof include nematic liquid crystal, chiral nematic liquid crystal, smectic liquid crystal, chiral smectic liquid crystal, discotic nematic liquid crystal, chiral discotic nematic liquid crystal, discotic columnar liquid crystal, and chiral discotic columnar liquid crystal. A low-molecular liquid crystal and / or a high-molecular liquid crystal exhibiting a liquid crystal property of The liquid crystal substance referred to in the present invention means a liquid crystal composition comprising one single liquid crystal compound and at least two liquid crystal compounds. In addition, as the liquid crystal compound, for example, dimers, trimers or quantifiers of so-called oligomers and polymers are also included in the present invention. Further, whether or not the liquid crystal material has a photopolymerizable functional group such as an acryl group, a methacryl group, a vinyl group, an allyl group, or a phthalimide group is not particularly limited. Further, when a liquid crystal substance having a photopolymerizable functional group is used and / or when a non-liquid crystalline photopolymerizable compound, which is an optional component described later, is blended, it accounts for the photocurable liquid crystalline composition of the present invention. The photopolymerizable functional group is described above so that the equivalent amount of the photopolymerizable functional group is usually 10 mmol / g or less, preferably 0.01 to 5 mmol / g, more preferably 0.1 to 3 mmol / g. It is desirable to adjust the composition ratio with the non-liquid crystalline compound represented by the general formula 1.
[0025]
Specific examples of the low-molecular liquid crystal include discotic compounds such as biphenyl derivatives, phenylbenzoate derivatives, stilbene derivatives, and other widely known calamitic (rod-like) liquid crystal compounds, triphenylene derivatives, torquesen derivatives, etc. Examples thereof include those having a basic skeleton of a discoid liquid crystal compound.
Examples of the polymer liquid crystal include condensation polymer liquid crystal represented by liquid crystalline polyester, vinyl polymer polymer liquid crystal, polysiloxane polymer liquid crystal, and epoxy polymer liquid crystal.
As the liquid crystal substance, either lyotropic property or thermotropic property can be used, but a material exhibiting thermotropic property is more preferable in terms of a film forming process.
The photocurable liquid crystalline composition of the present invention can be obtained at least from the non-liquid crystalline compound represented by the general formula 1 and the liquid crystal substance described above.
[0026]
Further, as the composition, as long as the finally obtained composition exhibits photocurability and liquid crystallinity, a non-liquid crystal compound other than the non-liquid crystal compound represented by the general formula 1 is optionally used as an optional component. A photopolymerizable substance exhibiting liquid crystallinity, a photoreaction initiator, and the like can be appropriately blended.
As a photopolymerizable substance, it means a non-liquid crystalline compound or a non-liquid crystalline composition having a functional group such as an acryl group, a methacryl group, a vinyl group, an allyl group, or a phthalimide group that can be polymerized and cured by light irradiation. However, the structure and composition ratio are not particularly limited.
When mix | blending a photopolymerizable substance, it is 50 weight% or less normally with respect to the composition of this invention, Preferably it is 40 weight% or less, More preferably, it can mix | blend at 5-30 weight%.
[0027]
Moreover, as a photoinitiator, 1 type or at least 2 or more types of the said initiator can be mix | blended with the composition of this invention. Examples of the photoinitiator include benzyl, benzoyl ether, benzoin isobutyl ether, benzoin isopropyl ether, benzophenone, benzoylbenzoic acid, methyl benzoylbenzoate, 4-benzoyl-4′-methyldiphenyl sulfide, benzylmethyl ketal, dimethylaminomethyl. Benzoate, 2-n-butoxyethyl-4-dimethylaminobenzoate, isoamyl p-dimethylaminobenzoate, 3,3′-dimethyl-4-methoxybenzophenone, methylobenzoyl formate, 2-methyl-1- (4- (Methylthio) phenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 1- (4-dodecylphenyl)- 2 Hydroxy-2-methylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2- Examples include methylpropan-1-one, 2-chlorothioxanthone, 2,4-diethylthioxanthone 2,4-diisopropylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 1-chloro-4-propoxythioxanthone and the like.
[0028]
The amount of the photoinitiator as described above is usually 0.01 to 20% by weight, preferably 0.1 to 10% by weight, more preferably 0.5 to 5% by weight, based on the composition of the present invention. can do.
In addition to the photoinitiator, the photocurable liquid crystalline composition of the present invention may further contain a sensitizer and the like as long as the effects of the present invention are not impaired.
The photocurable liquid crystalline composition of the present invention includes such a composition that can be cured by irradiation with EB (electron beam) without using any photoreaction initiator as described above. .
[0029]
The photocurable liquid crystal composition described above can be obtained with conventional photocurable liquid crystals that can improve the adhesion between the alignment substrate or alignment film and the liquid crystal layer after photocuring formed from the composition. Has the effect of being difficult. Therefore, when a liquid crystal film is prepared using the photocurable liquid crystalline composition of the present invention, the film having excellent adhesion can be obtained.
[0030]
It is desirable that the liquid crystal film of the present invention is provided on a support film or a support film having an alignment film and obtained through a heat treatment and a light irradiation process.
The support film is not particularly limited as long as it can be used as a liquid crystal alignment film. For example, polyimide, polyamideimide, polyamide, polyetherimide, polyetheretherketone, polyetherketone, polyketonesulfide, Polyethersulfone, polysulfone, polyphenylene sulfide, polyphenylene oxide, polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyacetal, polycarbonate, polyarylate, acrylic resin, polyvinyl alcohol, polypropylene, cellulose, triacetyl cellulose, surface saponification treatment Triacetylcellulose, epoxy resin, phenolic resin, etc. Rubbing plastic film subjected to direct rubbing treatment Lum and the like.
[0031]
A uniaxial or biaxial stretching operation may be appropriately added to the support film as necessary. Further, the support film may be subjected to a surface treatment such as a hydrophilic treatment or a hydrophobic treatment. Moreover, the said support film can also be used individually by 1 type and laminating | stacking 2 or more types of films as needed. In addition, as the support film, use a metal substrate such as aluminum, iron or copper with slit-shaped grooves on the surface, or a glass substrate such as alkali glass, borosilicate glass or flint glass whose surface is etched into a slit shape. You can also.
[0032]
Examples of the alignment film provided on the support film include polyimide, polyamide, and polyvinyl alcohol. Furthermore, the alignment film may be a deposited film obtained by obliquely depositing silicon oxide on a support film.
[0033]
Although the support film and alignment film described above can be used in the present invention, the effect of the present invention can be expected more significantly from the surface of the support film or alignment film on which the photocurable liquid crystalline composition is in contact. This is a case where the one having a hydroxyl group is used. Examples of such support film and alignment film include hydroxyl group-containing polyimide, polyamide, acrylic resin, phenol resin, cellulose, surface saponified triacetyl cellulose film, polyvinyl alcohol, and the like. The alignment film may be obtained using gelatin, chitin or the like as a raw material. In the present invention, among the above support films, a film obtained by saponifying the surface of the triacetyl cellulose film by an alkali treatment after forming the film is particularly preferable.
[0034]
When using a support film or an alignment film having a hydroxyl group on the surface with which the photocurable liquid crystalline composition layer of the present invention is in contact, the isocyanate group portion of the non-liquid crystalline compound constituting the composition described above is By reacting with the hydroxyl group by a heating step described later, it is possible to firmly fix the photocurable liquid crystalline composition layer and the surface of the support film or the alignment film surface through chemical bonds. Furthermore, since the non-liquid crystalline compound represented by the general formula 1 has a (meth) acryloyl group which is a photopolymerizable functional group, the composition was irradiated with light for curing. In the case where the composition contains a liquid crystal substance having a photopolymerizable functional group or a photopolymerizable substance exhibiting non-liquid crystallinity, if necessary, a photo-crosslinking reaction with the substance also occurs, so that curing occurs. The adhesion between the subsequent liquid crystal layer and the support film or alignment film can be significantly improved.
[0035]
Next, a method for arranging the photocurable liquid crystalline composition on the support film or the alignment film as described above will be described. As the method, solution coating performed by preparing a solution of a photocurable liquid crystalline composition is recommended in the present invention as a suitable method. Here, the solvent capable of dissolving the composition can be dissolved without impairing the characteristics of the photocurable liquid crystalline composition of the present invention, and the orientation ability of the support film or the orientation film can be improved when applied. There is no particular limitation as long as it does not attack and can further remove the solvent component by drying. When the isocyanate group in the non-liquid crystalline compound represented by the general formula 1 described above is used without protection, it is necessary to select a solvent that does not impair the effect of the compound. Such a solvent varies depending on the composition ratio of the photocurable liquid crystal composition, the type of the liquid crystal substance, etc., and cannot be generally stated. For example, carbonization of benzene, toluene, xylene, n-butylbenzene, diethylbenzene, tetralin, etc. Hydrogen solvents, ether solvents such as methoxybenzene, 1,2-dimethoxybenzene, diethylene glycol dimethyl ether, ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, ethyl acetate, ethylene glycol monomethyl ether acetate, propylene ethylene glycol monomethyl Ester solvents such as ether acetate and γ-butyrolactone, amide solvents such as 2-pyrrolidone, N-methyl-2-pyrrolidone, dimethylformamide and dimethylacetamide, Isocyanates such as hydroxyl groups and active methylene groups such as halogen solvents such as form, dichloromethane, carbon tetrachloride, dichloroethane, tetrachloroethane, tritrichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene, and mixed solvents in which at least two of the above solvents are mixed. The thing which does not have the functional group which can react with group is illustrated. However, it is not limited to this when the isocyanate group in the non-liquid crystalline compound represented by the general formula 1 is protected, and for example, tert-butyl alcohol, glycerin, ethylene glycol, triethylene glycol, ethylene Alcohols such as glycol monomethyl ether, ethyl cellosolve, butyl cellosolve, etc., phenols such as phenol and parachlorophenol, and mixed solvents obtained by mixing at least two of the above solvents can also be used in the present invention.
[0036]
Although the concentration of the solution depends on the solubility of the photocurable liquid crystalline composition and the final film thickness of the liquid crystal film, it cannot be generally stated, but is usually 1 to 60% by weight, preferably 3 to 40%. It is in the range of wt%.
[0037]
Further, a surfactant can be added to the solution. Surfactants include, for example, cationic surfactants such as imidazoline, quaternary ammonium salts, alkylamine oxides, polyamine derivatives, polyoxyethylene-polyoxypropylene condensates, primary or secondary alcohol ethoxylates. , Alkylphenol ethoxylates, polyethylene glycol and its esters, sodium lauryl sulfate, ammonium lauryl sulfate, amines of lauryl sulfate, alkyl-substituted aromatic sulfonates, alkyl phosphates, aliphatic or aromatic sulfonate formalin condensates, etc. Surfactants, amphoteric surfactants such as laurylamidopropyl betaine, laurylaminoacetic acid betaine, non-ionic surfactants such as polyethylene glycol fatty acid esters, polyoxyethylene alkylamine, etc. Perfluoroalkyl sulfonate, perfluoroalkyl carboxylate, perfluoroalkyl ethylene oxide adduct, perfluoroalkyl trimethyl ammonium salt, perfluoroalkyl group / hydrophilic group-containing oligomer, perfluoroalkyl / lipophilic group-containing oligomer par Fluorosurfactants such as fluoroalkyl group-containing urethane can be used. The addition amount of the surfactant depends on the kind of the surfactant, the photocurable liquid crystalline composition, the solvent, or the substrate film to be applied, but is usually 10 ppm to usually from the photocurable liquid crystalline composition. The range is 10%, preferably 100 ppm to 5%, more preferably 0.1% to 1%.
[0038]
As the solution coating method, a spin coating method, a roll coating method, a printing method, a dip pulling method, a curtain coating method (die coating method), or the like can be employed.
After coating, the solvent is removed by drying to form a photocurable liquid crystalline composition layer having a uniform film thickness on the support film or the alignment film. The conditions for drying and removing the solvent are not particularly limited, as long as the solvent can be generally removed and the liquid crystalline composition layer does not flow or even flow down. Usually, the solvent is removed using air drying at room temperature, drying on a hot plate, drying in a drying furnace, blowing hot air or hot air, and the like.
[0039]
The film thickness of the photocurable liquid crystalline composition layer after the solvent is removed by drying cannot be generally determined depending on the type of the composition or the use of the liquid crystal film. For example, the liquid crystal film of the present invention is used as a viewing angle improving film. When used as an optical compensation film such as a color compensation film or a phase difference plate, it is usually 0.01 μm to 100 μm, preferably 0.1 μm to 20 μm, more preferably 0.2 to 10 μm.
[0040]
The purpose of the coating / drying step is to first uniformly form a photocurable liquid crystalline composition layer on the support film, but depending on the type of the photocurable liquid crystalline composition, the solvent may be removed. The orientation may be completed thermotropic at a certain temperature or lyotropic in the process of removing the solvent. However, it is usually desirable in the present invention to perform the following heat treatment step in order to align the liquid crystal or to obtain a more uniform alignment state.
[0041]
The heat treatment is performed at a temperature equal to or higher than the liquid crystal transition point of the photocurable liquid crystalline composition. That is, the photocurable liquid crystalline composition is aligned in the liquid crystal state, or once it is in an isotropic liquid state having a higher temperature than the temperature range in which the liquid crystal phase is exhibited, and then the temperature is increased to the temperature range in which the liquid crystal phase is exhibited. Do by lowering. A method of changing the temperature within a temperature range exhibiting a liquid crystal phase can also be employed. For example, heat treatment at a high temperature within the temperature range exhibiting the same nematic phase, orienting the liquid crystal roughly, and then increasing the order of the liquid crystal alignment by lowering the temperature, or heat treating at a temperature exhibiting the nematic phase and nematic alignment Then, a method of lowering the temperature and aligning in a higher-order liquid crystal phase such as a smectic phase can also be used in the present invention.
[0042]
The heat treatment temperature varies depending on the composition ratio of the photocurable liquid crystal composition and the type of liquid crystal substance constituting the composition, but cannot be generally stated, but is usually 40 ° C to 220 ° C, preferably 50 ° C to 180 ° C, More preferably, it is performed in a range of 60 ° C to 160 ° C.
[0043]
In addition, the time required for the liquid crystal to be sufficiently oriented varies depending on the type of the photocurable liquid crystalline composition and the type of liquid crystal substance constituting the composition, but cannot be generally stated, but is usually 5 seconds to 2 hours. The range is preferably 10 seconds to 40 minutes, more preferably 20 seconds to 20 minutes. If the time is shorter than 5 seconds, the temperature of the liquid crystalline composition layer may not rise to a predetermined temperature and the alignment may be insufficient. Further, if it is longer than 2 hours, productivity is lowered, which is not desirable.
[0044]
By performing light irradiation after the heat treatment, a liquid crystal film in which the alignment state formed in the liquid crystal state is fixed can be obtained.
The wavelength of the light used for the light irradiation is not particularly limited, and an electron beam, an ultraviolet ray, a visible ray, or an infrared ray (heat ray) can be used as necessary. Usually, ultraviolet light or visible light is used, and irradiation light having a wavelength of 150 to 500 nm, preferably 250 to 450, more preferably 300 to 400 nm is suitably used.
[0045]
Low-pressure mercury lamps (sterilization lamps, fluorescent chemical lamps, black lights), high-pressure discharge lamps (high-pressure mercury lamps, metal halide lamps), short arc discharge lamps (super-high pressure mercury lamps, xenon lamps, mercury xenon lamps), etc. Is mentioned. Of these, ultraviolet light and visible light from metal halide lamps, xenon lamps, and high-pressure mercury lamps are the most common and can be suitably used in the present invention. A filter or the like is provided between the light source and the object to be irradiated (photocured liquid crystalline composition layer after heat treatment), and the wavelength region of the irradiation light source is limited by exposing and blocking a specific wavelength region. It doesn't matter.
The amount of light to be irradiated varies depending on the composition ratio of the photocurable liquid crystalline composition, the type and composition ratio of the liquid crystal substance, the addition amount of the photoreaction initiator, and the like, but cannot generally be said, but usually 2 to 5000 mJ / cm.², Preferably 10 to 3000 mJ / cm²More preferably, it is 100-2000mJ / cm²Range.
[0046]
The temperature at which the light irradiation is performed is not influenced by the liquid crystal phase behavior, fluidity, curability, etc. of the photocurable liquid crystalline composition, but cannot generally be said, but is usually 0 to 200 ° C., preferably 20 to 180. ° C, more preferably in the range of 25-160 ° C.
However, for example, a photocurable liquid crystalline composition having a high-order phase such as a smectic phase or a crystalline phase in a low temperature region near room temperature, and further having a temperature region of a nematic phase in the temperature region above the nematic phase. In the case of immobilization by photocuring in this state, it may be possible to immobilize a uniform nematic phase by performing light irradiation at a temperature equal to or higher than the phase transition point of the higher-order phase-nematic phase. Even when the nematic phase is fixed by supercooling by cooling after the heat treatment, the liquid crystal phase is vitrified and poor in fluidity, and the photocuring speed may be slow. When such a photocurable liquid crystalline composition is used, a liquid crystal film fixed in a more uniform alignment state is obtained by performing light irradiation after reheating to give fluidity. May be possible.
[0047]
Further, the light irradiation may be performed in several times, for example, by performing light irradiation once under heating to cure the photocurable liquid crystalline composition to some extent, cooling, and further performing light irradiation, etc. A method for improving the reaction rate of the photoreaction can also be adopted.
Furthermore, in this invention, you may perform what is called aging which heat-processes after light irradiation, and makes an unreacted site | part react further.
In any case, the temperature at which the light irradiation is performed needs to be appropriately adjusted depending on the type of the photocurable liquid crystalline composition used.
[0048]
Further, the light irradiation atmosphere cannot be generally described due to various factors such as the curability of the photocurable liquid crystalline composition, the type of photoreaction initiator, the intensity of irradiation light, and the irradiation temperature. For example, when the object to be cured (photocured liquid crystalline composition layer after heat treatment) is susceptible to curing inhibition by oxygen in the air, the member to be irradiated with light such as the object to be cured or the support film is in the air. Oxidation by oxygen may cause problems such as coloring. In addition, there is a possibility that ozone may be generated by irradiating strong light from the irradiation light source in the air. In such a case, for example, a method of performing light irradiation under nitrogen gas is adopted. In addition, an appropriate cover film such as a polyethylene terephthalate film, a polyethylene naphthalate film, a polyphenylene sulfide film, a polyarylate film, a polycarbonate film, or polyvinyl is used as long as the alignment state of the photocurable liquid crystalline composition after the heat treatment is not impaired. Oxygen blocking may be performed by covering with an alcohol film, a polyvinyl acetate film, a polyethylene film, a polypropylene film, a polyvinyl chloride film, a polyvinylidene chloride film, a polyamide film, a polyimide film, a polyethylene-acetic acid coextruded film, or the like.
[0049]
The liquid crystal film of the present invention obtained as described above is very excellent in interlayer adhesion between the liquid crystal layer after photocuring and the support film because of the properties of the above-mentioned photocurable liquid crystalline composition. In addition, since a desired alignment state can be fixed uniformly, depending on the alignment state, for example, an optical functional film used in a liquid crystal display element, specifically, a viewing angle improving film, a color compensation film, birefringence It can also be used as an optical rotatory film used for a type retardation compensation film, a head-up display, and the like. When the liquid crystal film of the present invention is used for the above-mentioned applications, its industrial utility value is extremely high because it can be a very suitable film in terms of optical performance, reliability, handleability, and mechanical strength.
[0050]
【Example】
Examples will be described below, but the present invention is not limited thereto. (Reference Example 1 Synthesis of Acrylic Group-Containing Isocyanate Compound)
Tolylene diisocyanate (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was purified by distillation, and weighed into a 10.0 g (57.4 mmol) flask and diluted with 50 ml of dichloromethane dehydrated with molecular sieve 4A. To this, 0.070 g (0.57 mmol) of 4-dimethylaminopyridine was added as a reaction catalyst, and further a solution of 12.3 g (57.4 mmol) of 6-hydroxy-2-ethylhexyl acrylate in dichloromethane was stirred at room temperature while stirring. It was dripped at. Thereafter, the flask was immersed in a 60 ° oil bath and heated, and reacted in a reflux state for 6 hours. Thereafter, the reaction solution was concentrated by a rotary evaporator to obtain 24.2 g of a viscous brown liquid product containing some solvent (reaction product 1).
[0051]
The obtained product was thinly applied to a rock salt plate, and transmission IR spectroscopic measurement was performed with FT / IR-7000 manufactured by JASCO Corporation. Wavenumbers of 2200 to 2300 cm characteristic of isocyanate groups were found.^-1A sharp absorption peak, 3300-3600 cm derived from a carbamic acid ester bond formed by reaction of an isocyanate group^-1Slightly broad absorption peak and 1690-1780cm^-1A strong absorption peak was observed.
[0052]
GPC analysis was performed to quantify the product composition. Analysis was performed using Tosoh GPC analyzer CCP & 8000 (CP-8000, CO-8000, RI-8000) equipped with a high-speed GPC packed column (TSKgel G-1000HXL) using dehydrated tetrahydrofuran as an elution solvent. It was. The measurement was performed using a THF diluted sample of reaction product 1. The peaks detected from the sample are unreacted tolylene diisocyanate, a 1: 1 adduct of tolylene diisocyanate and 6-hydroxy 2-ethylhexyl acrylate (compound 2), and 6-hydroxy 2-hydroxyl to 1 mol of tolylene diisocyanate. It was a compound (compound 3) obtained by reacting 2 mol of ethylhexyl acrylate. From the integrated value ratio of the peaks, it was found that the reaction liquid sample had a molar ratio of tolylene diisocyanate of 14.7%, compound 2 of 84.7%, and compound 3 of 0.6%.
[0053]
(Reference Example 2)
In a 500 ml Erlenmeyer flask, 450 ml of 0.98 N sodium hydroxide aqueous solution was prepared using sodium hydroxide (Wako Pure Chemical Industries) and ultrapure water. This aqueous solution was transferred to a Teflon bat having a depth of 6 cm and a 35 cm square, and heated to 50 ° C. on a hot plate with a glass plate placed on the top of the bat in order to eliminate the influence of carbon dioxide in the atmosphere. A triacetyl cellulose film (Fujitac UVD-80 manufactured by Fuji Photo Film Co., Ltd.) cut into a 30 cm square was immersed therein and saponified for 5 minutes. After the treatment, the film was washed away with an alkali in a pure water shower, then sufficiently immersed in a neutral phosphate standard buffer (manufactured by Wako Pure Chemicals, pH 6.86 at 25 ° C.), and then washed with pure water again. went. The obtained film was removed with a dry air gun, and then further dried in an oven at 80 ° C. for 10 minutes.
Table 1 shows the results of measuring the pure water contact angle of the raw material triacetylcellulose film and the obtained saponified triacetylcellulose film with a contact angle measuring device CA-A manufactured by Kyowa Interface Science Co., Ltd.
[0054]
[Table 1]

[0055]
Example 1
4 g of bis (4- (8-acryloyloxyoctyloxy) benzoic acid) ester (liquid crystal substance 1) of methylhydroquinone and 0.2 g of reaction product 1 synthesized in Reference Example 1 (relative to liquid crystal substance 1) A photocurable liquid crystalline composition 1 comprising 5% by weight and about 4.7% by weight of the non-liquid crystalline compound 2 as an active ingredient in the reaction product 1) was prepared.
Next, the composition 1 was dissolved in 15.8 g of m-xylene to prepare a 21 wt% solution. 0.021 g (0.5% by weight based on Composition 1) of a fluorine-based surfactant (S-383 Asahi Glass Co., Ltd.) and 0.084 g of a photoreaction initiator (Irgacure 369 manufactured by Ciba Geigy) (2% by weight based on composition 1) was added to prepare a photocurable liquid crystalline composition solution.
[0056]
Subsequently, the surface saponification-treated triacetyl cellulose film obtained in Reference Example 2 was rubbed with polyamide fibers. A photocurable liquid crystalline composition solution filtered through a 0.5 μm-diameter Teflon filter was applied to the rubbing treated surface by dip coating, dried in an oven set at 50 ° C. for 5 minutes, and further in an oven set at 80 ° C. Then, heat treatment was performed for 15 minutes in a nitrogen atmosphere.
After the heat treatment, the liquid crystal film 1 (structure: surface saponified triacetyl cellulose film / liquid crystal film 1) is obtained by irradiating 1200 mJ light with an integrated amount of 365 nm light with a high pressure mercury lamp installed in an oven. Obtained.
The liquid crystal surface of the liquid crystal film 1 was cured to a pencil hardness of about HB.
[0057]
Next, when the liquid crystal film 1 is placed on the backlight and observed between two polarizing plates in a crossed Nicol arrangement, a uniformly oriented nematic liquid crystal phase having positive birefringence in the rubbing direction is fixed. There was found.
It was 1.7 micrometers when the film thickness of the film 1 was measured with the stylus type film thickness meter. When this sample was measured for birefringence under a polarizing microscope using a Belek compensator, it was found to have an axis in the rubbing direction and a retardation of 187 nm.
Subsequently, in order to evaluate the adhesiveness between the liquid crystal film 1 and the triacetyl cellulose film, a film base test (JIS standard K5400) was performed. As a result, no peeling occurred in all the cells.
[0058]
(Comparative Example 1)
A liquid crystal solution containing the liquid crystal substance 1 and not containing the reaction product 1 was prepared in the same manner as in Example 1, and the same operation as in Example 1 was performed to prepare a comparative film 1.
The alignment state and the degree of curing of the obtained comparative film 1 were almost the same as those of the liquid crystal film 1 obtained in Example 1.
Further, the film thickness of the comparative film 1 was 1.6 μm by stylus measurement, and the retardation was 184 nm.
When the base film test was conducted on the comparative film 1 in the same manner as in Example 1, peeling occurred in all the cells, and there was no resistance at the time of peeling.
[0059]
(Reference Example 3 Synthesis of Acrylic Group-Containing Isocyanate Compound)
After isophorone diisocyanate (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was distilled and purified, it was weighed into a 20.0 g (90 mmol) flask and diluted with 80 ml of tetrahydrofuran distilled twice. To this was added 0.3 g (1.8 mmol) of dibutyltin diacetate as a reaction catalyst, and the flask was immersed in a 60 ° oil bath and heated in a nitrogen atmosphere. A 20 ml tetrahydrofuran solution of 12.53 g (108 mmol) of 2-hydroxyethyl acrylate was added dropwise to the warmed state of this solution over 15 minutes. After completion of the dropping, the reaction solution was heated to the reflux temperature and reacted for 2 hours with stirring. Thereafter, the reaction solution was concentrated by a rotary evaporator to obtain 33.2 g of a viscous liquid product containing some solvent (reaction product 4).
[0060]
In order to quantify the composition of the obtained product, GPC analysis of the product was performed in the same manner as in Reference Example 1. The peak detected from the sample was a 1: 1 adduct of isophorone diisocyanate and hydroxyethyl acrylate (compound 5), and a compound (compound 6) obtained by reacting 2 mol of hydroxyethyl acrylate with 1 mol of isophorone diisocyanate. From the integrated value ratio of the peaks, it was found that the reaction solution sample was 80.5% of compound 5 and 19.5% of compound 6 in terms of molar ratio. As a result, among the hydroxyethyl acrylates added in 1.2 equivalents relative to the number of moles of isophorone diisocyanate, approximately 1 equivalent reacted with one of the reactive isocyanate groups of isophorone diisocyanate, and the remaining 0.2 equivalents. Was almost in agreement with the equivalent relationship in that it reacted with the isocyanate group on the other side.
[0061]
(Reference Example 4 Synthesis of hexakis (6- (9-acryloyloxynonyloxy) -2-naphthalenecarboxy) torquecene (liquid crystal substance 2))
10.0 g (12.5 mmol) of hexaacetoxy torquesen and 36.8 g (87.6 mmol) of 6- (9-benzyloxynonyloxy) -2-naphthalenecarboxylic acid were weighed into a flask, and the flask was placed under a nitrogen atmosphere at 270. It was immersed in an oil bath heated to ° C and heated. After 15 minutes, the reaction started with melting of the carboxylic acid component, and acetic acid began to form. A branch pipe was attached to the flask, and the acetic acid flowing out was cooled with a condenser and stirred out while being removed from the system, and reacted at that temperature for 2 hours. Further, the reaction was carried out for 2 hours at a flow of 50 ml / min for 2 hours while flowing nitrogen at 30 ml / min inside the flask. After completion of the reaction, the product shows liquid crystallinity and fluidity at the reaction temperature. When the contents are extracted from the flask in this state, 38.4 g of a light yellow solid (recovery rate: 93%) is obtained as a product at room temperature. Obtained.
[0062]
From the 1H-NMR measurement (270 MHz, chloroform-d solvent) of the product, it was found that the product contained 95% or more of hexakis (6- (9-benzyloxynonyloxy) -2-naphthalenecarboxy) torquecene as a main component. It was. The product was observed under a polarizing microscope while being heated on a Mettler hot stage. At 200 ° C, the discotic nematic liquid crystal phase, the isotropic transition temperature was 300 ° C or higher, and it was cooled from 200 ° C to 10 ° C / minute to room temperature. However, no crystal phase or higher-order liquid crystal phase was observed.
[0063]
The total amount of this hexakis (6- (9-benzyloxynonyloxy) -2-naphthalenecarboxy) torxene was dissolved in a mixed solvent of 160 ml of ethyl acetate and 40 ml of ethyl alcohol, and further palladium-carbon (N Chemchem Co., Ltd.). Manufactured, 5% palladium supported, K type) was added and transferred to a 500 ml pressure vessel. The inside of the container is replaced with hydrogen gas, and further hydrogen is 5 kg / cm.²The pressure was increased to In this state, the reaction was allowed to proceed for 12 hours at room temperature to effect debenzylation. After completion of the reaction, the reaction solution was filtered through Celite and concentrated by a rotary evaporator to obtain pale yellow crystals. This was washed with methanol, dried in a vacuum dryer at 60 ° C. and 0.5 mmHg for 12 hours, and the product hexakis (6- (9-hydroxynonyloxy) -2-naphthalenecarboxy) torquecene 30.5 g (98%) was obtained. In the 1H-NMR measurement (270 MHz, DMSO-d6 solvent) of the product, the peak near 4.5 ppm derived from the benzyl group disappeared completely, and it was confirmed that debenzylation was performed almost quantitatively. did.
[0064]
The total amount of the obtained hexakis (6- (9-hydroxynonyloxy) -2-naphthalenecarboxy) torxene was dissolved in 150 ml of tetrahydrofuran, 10.0 g (98.9 mmol) of distilled and purified triethylamine was added, and the mixture was cooled to 0 ° C. While stirring, a tetrahydrofuran solution of 8.95 g (98.9 mmol) of acrylic acid chloride (Tokyo Kasei reagent) was gradually added dropwise. After 30 minutes, the flask was heated to 40 ° C. and reacted for another 2 hours. The reaction solution was diluted with 300 ml of ethyl acetate, and 200 ml of 1N hydrochloric acid was added to carry out a liquid separation operation. Furthermore, the organic layer was washed twice with 100 ml of 1N aqueous hydrochloric acid and twice with a saturated aqueous sodium hydrogen carbonate solution. Water was removed by adding 20 g of anhydrous magnesium sulfate to the washed organic layer and stirring well. After removing the magnesium sulfate by filtration, the solution was concentrated by a rotary evaporator to obtain a viscous liquid crystal. When this was dispersed in 300 ml of methanol and stirred vigorously while cooling to −20 ° C., it gradually crystallized, and when filtered and washed with methanol, white crystals were obtained. The weight after vacuum drying was 31.3 g (yield 90%). When 1H-NMR measurement (270 MHz, chloroform-d solvent) of the product was performed, hexakis (6- (9-acryloyloxynonyloxy) -2-naphthalenecarboxy) torquecene (liquid crystal substance 2) was contained as a main component. I understood it.
[0065]
When the product was observed under a polarizing microscope while heating on a Mettler hot stage, it showed a discotic nematic liquid crystal phase at 120 °, and no isotropic transition occurred until polymerization of the acrylic group started at around 200 °. When the temperature was cooled from 120 ° C. to 10 ° C./min to room temperature, a high-order liquid crystal phase was observed at around 85 ° C. and a crystal phase was observed at around 50 ° C.
The product was purified twice by silica gel column chromatography and then further purified by recrystallization to obtain liquid crystal substance 2 in the form of white crystals. Tosoh GPC analyzer CCP & 8000 (CP-8000, CO-8000, RI-8000) equipped with a packed column for high-speed GPC (TSKgel G-1000HXL) using tetrahydrofuran dehydrated as an elution solvent for GPC analysis of the product As a result, a sub-peak less than 1% was observed in the vicinity of the peak derived from the liquid crystal substance 2. Therefore, it was found that the purity of the liquid crystal substance 2 after purification was 99% or more.
[0066]
(Reference Example 5)
10 g of polyvinyl alcohol (MP-203, manufactured by Kuraray Co., Ltd.) was dissolved in 95 g of a 1/1 mixed solvent at a weight ratio of water / 2-propanol to prepare a 5 wt% solution.
One surface of a triacetylcellulose film (Fujitac UVD-80 manufactured by Fuji Photo Film Co., Ltd.) was subjected to gelatin treatment to improve adhesion, and then a polyvinyl alcohol solution was applied to the gelatin treated surface by a spin coating method. After coating, the glass substrate used for coating was dried on a hot plate at 60 ° C. for 30 minutes, and further dried in an oven set at 100 ° C. for 10 minutes. The polyvinyl alcohol film formed on the triacetyl cellulose film was in close contact with the supporting triacetyl cellulose film through the gelatin layer, and the polyvinyl alcohol surface was not easily peeled off with cellophane or the like. Further, when a sample obtained by partially removing the polyvinyl alcohol layer after drying was measured with a stylus type film thickness meter, the film thickness of the polyvinyl alcohol layer was 1.1 μm.
[0067]
(Example 2)
4 g of hexakis (6- (9-acryloyloxynonyloxy) -2-naphthalenecarboxy) torquecene (liquid crystal substance 2) obtained in Reference Example 4 and 0.3 g of the reaction product 4 synthesized in Reference Example 3 were obtained. A photocurable liquid crystalline composition 2 comprising 7.5% by weight with respect to the liquid crystal substance 2 and about 5.6% by weight of the non-liquid crystalline compound 5 as an active ingredient in the reaction product 4 is prepared. did.
The composition was then dissolved in 15.7 g of 2-butoxyethyl acetate to prepare a 21.5 wt% solution. Further, 0.215 g of tetraethylene glycol diacrylate (5% by weight with respect to composition 2) and 0.0323 g of a fluorosurfactant (0.75 with respect to composition 2) were used as non-liquid crystalline photopolymerizable substances. % By weight) and a photoinitiator (Irgacure-907 manufactured by Ciba Geigy) 0.258 g (6% by weight with respect to Composition 2) were added to prepare a photocurable liquid crystal composition solution.
[0068]
This solution was filtered through a 0.45 μm-diameter Teflon filter, and then the polyvinyl alcohol alignment film obtained in Reference Example 5 was rubbed with polyamide fibers. The rubbing-treated surface was coated with a photocurable liquid crystalline composition solution filtered through a 0.45 μm diameter Teflon filter by a percoat method, dried on a hot plate set at 50 ° C. for 60 minutes, and then in an oven set at 165 ° C. Heat treatment was performed for 10 minutes. After the heat treatment, it was taken out from the oven, and photocured by irradiating 800 mJ of light with an integrated amount of 365 nm light with a high-pressure mercury lamp in a nitrogen atmosphere. Further, a polyethylene terephthalate film whose surface was treated with silicon was laminated on the liquid crystal layer surface, and light irradiation of 1200 mJ was performed again through the film to obtain a liquid crystal film 2 (configuration: triacetyl cellulose film / polyvinyl alcohol alignment film / liquid crystal film 2). .
[0069]
The liquid crystal surface of the obtained liquid crystal film 2 is cured to a pencil hardness of about 2H. When the film 2 is observed between two polarizing plates in a crossed Nicol arrangement on a backlight, a discotic liquid crystal is obtained. It was proved that a hybrid alignment structure was obtained. Moreover, the film 2 had retardation in the surface and the direction corresponded with the rubbing direction. The retardation was -55 nm, and it was found that a uniformly oriented discotic nematic liquid crystal phase exhibiting negative birefringence was fixed.
It was 2.2 micrometers when the film thickness of the liquid crystal film 2 was measured with the stylus type film thickness meter.
In order to evaluate the adhesiveness of the liquid crystal film 2, a base eye test was conducted by the same method as in Example 1. As a result, no peeling occurred at all the squares.
[0070]
(Comparative Example 2)
A comparative film 2 was prepared in the same manner as in Example 2 except that the reaction product 4 was not added.
Using the comparative film 2, preparations were made to perform a foundation eye test in the same manner as in Example 1. As a result, peeling occurred and the test could not be performed.

Claims (2)

Support film or oriented layers of photocurable liquid crystal composition containing a non-liquid crystalline compound consisting of a photopolymerizable liquid crystal material and one or more isocyanate groups (meth) acrylate compound to the surface having a hydroxyl group A liquid crystal film formed from a composite disposed on a film. A photocurable liquid crystal composition comprising a photopolymerizable liquid crystal substance and a non-liquid crystal compound comprising a (meth) acrylate compound having one or more isocyanate groups on a support film or alignment film having a hydroxyl group on the surface. A method for producing a liquid crystal film, comprising applying liquid crystal to align liquid crystals and then irradiating with light.