JP4604438B2 - Photo-alignment film material, photo-alignment film and method for producing the same - Google Patents
Photo-alignment film material, photo-alignment film and method for producing the same Download PDFInfo
- Publication number
- JP4604438B2 JP4604438B2 JP2001294300A JP2001294300A JP4604438B2 JP 4604438 B2 JP4604438 B2 JP 4604438B2 JP 2001294300 A JP2001294300 A JP 2001294300A JP 2001294300 A JP2001294300 A JP 2001294300A JP 4604438 B2 JP4604438 B2 JP 4604438B2
- Authority
- JP
- Japan
- Prior art keywords
- group
- photo
- alignment
- carbon atoms
- groups
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 0 CC(C(N1****)=O)=C(*)C1=O Chemical compound CC(C(N1****)=O)=C(*)C1=O 0.000 description 2
Landscapes
- Liquid Crystal (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、液晶表示素子に用いられる光配向膜に関し、さらに詳しくは、光を照射することにより、ラビングを行うことなく液晶分子を配向させることができる光配向膜の形成材料、該材料からなる光配向膜、その製造方法及び該光配向膜を用いた液晶表示素子に関する。
【０００２】
【従来の技術】
液晶表示装置においては、液晶の分子配列の状態を電場等の作用によって変化させて、これに伴う光学的特性の変化を表示に利用している。多くの場合、液晶は二枚の基板の間隙に挟んだ状態で用いられるが、ここで液晶分子を特定の方向に配列させるために、基板の内側に配向処理が行われる。
【０００３】
通常、配向処理には、ガラス等の基板にポリイミド等の高分子の膜を設け、これを一方向に布等で摩擦する、ラビングという方法が用いられる。しかし、この方法は、製造工程において静電気や埃が発生するため、配向処理後の洗浄工程が必要となる。また、特に近年多く用いられているＴＦＴ方式の液晶セルでは、ラビング時の摩擦により静電気が発生し、あらかじめ基板に設けられたＴＦＴ素子が破壊されることもあり、これが製造における歩留まり低下の原因にもなっている。
【０００４】
これに対し、近年、斜方蒸着法、ＬＢ（ラングミュアー−ブロジェット）膜法、フォトリソグラフィ法、光配向法等のような、ラビングを行わない液晶配向制御技術が注目されてきている。とりわけ、偏光された光を基板上に設けられた塗膜に照射して、液晶配向性を生じさせる光配向法は、簡便且つ、配向処理後の洗浄工程が不必要であることから、盛んに研究が行われている。
この光配向法は、有機分子中の光配向機能を発現させる光配向性基、例えばアゾ基等の光異性化反応、シンナモイル基、クマリン基、カルコン基等の光二量化反応、ベンゾフェノン基等の光架橋やポリイミド樹脂等の光分解反応等を利用したものが報告されている。これらは、ガラス等の基板に塗布した際に均一な膜が得られるように高分子材料を用い、かつ光配向性基を側鎖や主鎖に導入する場合が多い。また、光配向性を有する分子をゲスト分子とし、高分子化合物からなるホスト化合物に分散させて用いる場合もある。
【０００５】
しかし、これらの高分子材料を用いた光配向膜材料の多くは、液晶配向能および耐熱性が十分ではないといった問題がある。例えば、液晶表示素子の製造工程では、基板に液晶配向膜を形成後液晶セルに組み立てる際、封止剤を硬化させる目的で加熱処理が行われるが、この時、液晶配向膜の耐熱性が十分でないと、液晶配向能の劣化を生じてしまう。
耐熱性を向上させるためには、架橋構造を有する高分子材料を用いる場合があるが、架橋構造を有する高分子化合物の多くは、溶剤に対する溶解性が乏しく、基板に塗布する際に用いることのできる溶剤の種類が著しく制限され、実用的には好ましくない。
【０００６】
このような欠点を克服し、光配向膜の液晶配向能を安定に得る方法として、光配向性基を有する重合性モノマーを基板上に塗布した後、重合させる方法が、特開２００１−４８９０４号公報に開示されている。しかし、モノマーを熱もしくは光重合させるには重合開始剤の添加が必要となる。この重合開始剤は低分子化合物であるため、重合後であっても、長期間が経過すると、セル内の液晶層に残存する重合開始剤が拡散し、液晶表示素子としての特性、例えば電圧保持率を劣化させるおそれがある。また、酸素による重合阻害を防ぐために窒素雰囲気下で重合を行わなければならないといった問題もある。
【０００７】
重合開始剤が不要で空気中でも光重合反応が可能な化合物として、マレイミド化合物が挙げられる。このようなものとして、特開２００１―１２２９８１号公報には、重合性マレイミド基を有する芳香族化合物を用いた光配向膜材料が開示されているが、この化合物による光配向能は未だ十分ではない。
【０００８】
一方、液晶配向膜に求められる特性の一つに、液晶分子に適度なプレチルト角を与えることが挙げられる。特に、TNやSTN方式の液晶表示素子では、プレチルト角が小さいと、ねじれ方向の異なるドメイン状の欠陥が生じたり、ディスクリネーションと呼ばれる線状の配向欠陥を生じることがある。
従来のラビング膜は、一定の向きにラビング処理を施すことによって容易に液晶分子のプレチルト角を得ることができる。しかし、光配向膜の場合、桂皮酸誘導体やクマリン誘導体を側鎖に有する高分子膜よりなる光配向膜に斜め方向から直線偏光や無偏光を照射する方法によりプレチルトが得られることが知られているが、得られるプレチルト角は小さいうえ、加熱あるいは経時的に不安定であるといった問題を有する。また、上記のマレイミド化合物を使用した光配向膜用材料であっても、十分なプレチルト角は得られず、実用化にはなお問題を有している。
【０００９】
以上のように、優れた液晶配向能が得られ、生産性に優れ、耐熱性や長期安定性を有し、且つ十分なプレチルト角を得られるとともに、良好な液晶素子特性を示す光配向膜用材料は未だ得られていないのが現状である。
【００１０】
【発明が解決しようとする課題】
本発明が解決しようとする課題は、塗布時の溶媒に対する溶解性が高く、さらに良好な液晶配向性を示すとともに、十分な液晶分子のプレチルト角が得られ、かつこのプレチルト角が熱的、経時的に十分な安定性を有する液晶表示素子用の光配向膜を提供することにある。
【００１１】
【課題を解決するための手段】
すなわち、本発明は上記課題を解決するために、（ａ）１分子中に光二量化反応により光配向機能を発現する少なくとも１個の光配向性基と、少なくとも２個の重合性マレイミド基とを有する単量体、及び、（ｂ）１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基とを有するが、光配向性基を有さない単量体を含有する光配向膜用材料を提供する。
【００１２】
また、本発明は上記課題を解決するために、（ａ）１分子中に少なくとも１個の光二量化反応により光配向機能を発現する光配向性基と少なくとも２個の重合性マレイミド基を有する単量体、及び、（ｂ）１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基を有するが、光配向性基を有さない単量体との共重合体を含有し、（ａ）の単量体が有する光配向性基の光二量化により発現した光配向機能と、（ａ）及び（ｂ）の単量体が有する重合性マレイミド基の重合により生じた架橋構造とを有する光配向膜を提供する。
【００１３】
また、本発明は上記課題を解決するために、上記記載の光配向膜用材料を基板上に塗布し、該塗膜を加熱することにより前記重合性マレイミド基の熱重合反応を生起させて架橋された高分子膜を形成し、前記高分子膜に光照射することにより前記構造単位の光二量化反応を生起させて前記高分子膜に光配向機能を発現させる光配向膜の製造方法を提供する。
【００１４】
また、本発明は上記課題を解決するために、内側に配向膜を有する二枚の基板間に液晶を挟持した構造を有する液晶表示素子において、前記配向膜が、（ａ）１分子中に少なくとも１個の光二量化反応により光配向機能を発現する光配向性基と少なくとも２個の重合性マレイミド基を有する単量体、及び、（ｂ）１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基を有する単量体との共重合体を含有し、前記光配向性基の光二量化により発現した光配向機能と前記重合性マレイミド基の重合により生じた架橋構造とを有する光配向膜である液晶表示素子を提供する。
【００１５】
【発明の実施の形態】
本発明の光配向膜用材料に使用する、１分子中に、光二量化反応により光配向機能を発現する少なくとも１個の光配向性基と、少なくとも２個の重合性マレイミド基を有する単量体において、光二量化反応により光配向機能を発現する光配向性基は、偏光照射によって引き起こされる異方的な二量化反応により、光反応を生起し、配向性が得られるような官能基であるならば特に限定されないが、中でもＣ＝Ｃ、Ｃ＝Ｏで表わされる少なくとも一つの二重結合（但し、芳香環を形成する二重結合を除く）を有する構造単位が特に好ましく用いられる。
【００１６】
これらの光二量化反応によって光配向機能を発現する光配向性基の基本構造としては、以下のものが挙げられる。
Ｃ＝Ｃ結合を有する光二量化反応によって光配向機能を発現する光配向性基としては、例えば、ポリエン骨格、スチルベン骨格、スチルバゾール骨格、スチルバゾリウム骨格、シンナモイル骨格、ヘミチオインジゴ骨格、カルコン骨格等の構造を有する基が挙げられる。Ｃ＝Ｏ結合を有する光二量化反応によって光配向機能を発現する光配向性基としては、例えば、ベンゾフェノン骨格、クマリン骨格等の構造を有する基が挙げられる。
【００１７】
中でも、ベンゾフェノン骨格、シンナモイル骨格、カルコン骨格及びクマリン骨格からなる１〜４価の基の群から選ばれる光配向性基が好ましく、具体的には、以下の構造で表される。勿論、これらの構造にアルキル基、アルコキシ基、アリール基、アリルオキシ基、シアノ基、アルコキシカルボニル基、ヒドロキシル基、スルホン酸基、ハロゲン化アルキル基等の置換基を有していても良い。
【００１８】
【化４】
具体的には、１分子中に少なくとも１個の光二量化反応により光配向機能を発現する光配向性基と少なくとも２個の重合性マレイミド基を有する単量体は、一般式（１）
【化５】
【００２０】
【化６】
【００２１】
一般式（１）及び（４）において、Ｒ１は、炭素原子数１〜３０の直鎖状又は分岐状アルキレン基、炭素原子数３〜１２のシクロアルキレン基、アリールアルキレン基及びシクロアルキルアルキレン基からなる群より選ばれる少なくとも１つの基を表わす。
【００２２】
Ｒ１を表わす基の具体例としては、例えば、メチレン基、エチレン基、トリメチレン基、テトラメチレン基、ペンタメチレン基、ヘキサメチレン基、ヘプタメチレン基、オクタメチレン基、ノナメチレン基、デカメチレン基、ウンデカメチレン基、ドデカメチレン基の如き直鎖状アルキレン基；１−メチルエチレン基、１−メチル−トリメチレン基、２−メチル−トリメチレン基、１−メチル−テトラメチレン基、２−メチル−テトラメチレン基、１−メチル−ペンタメチレン基、２−メチル−ペンタメチレン基、３−メチルペンタメチレン基、ネオペンチル基の如き分岐アルキル基を有するアルキレン基；
【００２３】
シクロペンチレン基、シクロヘキシレン基の如きシクロアルキレン基；ベンジレン基、２，２−ジフェニル−トリメチレン基、１−フェニル−エチレン基、１−フェニル−テトラエチレン基の如き主鎖または側鎖にアリール基を有するアリールアルキレン基；シクロヘキシルメチレン基、１−シクロヘキシル−エチレン基、１−シクロヘキシル−テトラエチレン基の如き主鎖あるいは側鎖にシクロアルキル基を有するシクロアルキル−アルキレン基等が挙げられる。これらの中でも、炭素原子数１〜３０のアルキレン基又は炭素原子数３〜１２のシクロアルキレン基が好ましい。
【００２４】
また、Ｒ１は、これら上記に挙げた基の２〜５個が、単結合、エステル結合、エーテル結合またはウレタン結合で連結した基であっても良い。
【００２５】
このような連結された基としては、例えば、少なくとも２つのアルキレン基が、エーテル結合で結合された（ポリ）エーテルから構成される基、少なくとも２つのアルキレン基がエステル結合で結合された（ポリ）エステルから構成される基、少なくとも２つのアルキレン基がウレタン結合で結合された（ポリ）ウレタンから構成される基、少なくとも２つのアルキレン基が、エーテル結合で結合された（ポリ）エーテル（ポリ）オールと（ポリ）カルボン酸とをエステル化して得られる（ポリ）カルボン酸｛（ポリ）エーテル（ポリ）オール｝エステルから構成される基等が挙げられる。
【００２６】
上記一般式（１）及び（４）において、Ｒ２は上記した光二量化反応によって光配向機能を発現する光配向性基を表わす。
【００２７】
一般式（１）及び（４）で表わされる化合物において、これらＲ２で表わされる光二量化反応によって光配向機能を発現する光配向性基は、Ｒ１で表わされる基と、単結合、エステル結合又はウレタン結合を介して結合している。光二量化反応によって光配向機能を発現する光配向性基の結合数は、１分子中に有する重合性マレイミド基の数と同数であるが、本発明で使用するマレイミド誘導体は、複数の重合性マレイミド基を有するため、その数は２から４までの範囲が好ましい。中でも、重合性マレイミド基の重合が容易に進行し、安定なマレイミド重合体を形成すること、光配向機能を発現する光配向性基の光配向を発現するに必要な光エネルギーの量が比較的少ないことから、光二量化反応によって光配向機能を発現する光配向性基の結合数は２個であることが好ましい。
【００２８】
上記一般式（１）及び（４）において、Ｒ３及びＲ４は、各々独立して、水素原子、炭素原子数１〜８のアルキル基、フェニル基またはハロゲン原子を表わす。
【００２９】
上記一般式（１）において、ｎは、２から４までの整数を表わす。中でも、重合性マレイミド基の重合が容易に進行し、安定なマレイミド重合体を形成すること、光配向性基の光配向機能を発現するに必要な光エネルギーの量が比較的少ないことから、ｎが２である一般式（４）で表わされる化合物が特に好ましい。
【００３０】
本発明で使用する、１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基を有する単量体は、具体的には、一般式（２）又は（３）で表される。
【００３１】
【化７】
【化８】
一般式（２）および（３）において、Ｒ５、Ｒ９、Ｒ１０、およびＲ１１は、炭素原子数１〜１０の直鎖状又は分岐状アルキレン基、炭素原子数３〜１２のシクロアルキレン基、アリールアルキレン基及びシクロアルキルアルキレン基からなる群より選ばれる少なくとも１つの基を表す。
【００３４】
これらＲ５、Ｒ９、Ｒ１０、およびＲ１１の具体例としては、例えば、メチレン基、エチレン基、トリメチレン基、テトラメチレン基、ペンタメチレン基、ヘキサメチレン基、ヘプタメチレン基、オクタメチレン基、ノナメチレン基、デカメチレン基、ウンデカメチレン基、ドデカメチレン基の如き直鎖状アルキレン基；１−メチルエチレン基、１−メチル−トリメチレン基、２−メチル−トリメチレン基、１−メチル−テトラメチレン基、２−メチルテトラメチレン基、１−メチル−ペンタメチレン基、２−メチル−ペンタメチレン基、３−メチル−ペンタメチレン基、２，２−ジメチル−トリメチレン基の如き分岐アルキル基を有するアルキレン基；
【００３５】
シクロペンチレン基、シクロヘキシレン基の如きシクロアルキレン基；ベンジレン基、２，２−ジフェニル−トリメチレン基、１−フェニル-エチレン基、１−フェニル−テトラエチレン基の如き主鎖又は側鎖にアリール基を有するアリールアルキレン基；シクロヘキシルメチレン基、１−シクロヘキシル−エチレン基、１−シクロヘキシル−テトラエチレン基の如き主鎖あるいは側差にシクロアルキル基を有するシクロアルキル−アルキレン基等が挙げられる。これらの中でも炭素原子数１〜１０のアルキレン基又は炭素原子数３〜１２のシクロアルキレン基が好ましい。
【００３６】
また、Ｒ５、Ｒ９、Ｒ１０、およびＲ１１は、これら上記に挙げた基の２〜５個が、単結合、エステル結合、エーテル結合、またはウレタン結合で連結した基であっても良い。このような連結された基としては、例えば、少なくとも２つのアルキレン基が、エーテル結合で結合された（ポリ）エーテルから構成される基、少なくとも２つのアルキレン基がエステル結合で結合された（ポリ）エステルから構成される基、少なくとも２つのアルキレン基がウレタン結合で結合された（ポリ）ウレタンから構成される基、少なくとも２つのアルキレン基が、エーテル結合で結合された（ポリ）エーテル（ポリ）オールと（ポリ）カルボン酸とをエステル化して得られる（ポリ）カルボン酸｛（ポリ）エーテル（ポリ）オール｝エステルから構成される基等が挙げられる。
【００３７】
上記一般式（２）および（３）において、Ｒ６およびＲ１３は、炭素原子数が４〜３０のアルキル基を表す。具体的には、ステアリル基、ラウリル基、トリデシル基、ミリスチル基、ペンタデシル基、セチル基、ヘプタデシル基、ノナデシル基等が挙げられる。なお、これらのアルキル基は、置換基としてアルキル基を有していても差し支えない。
【００３８】
上記一般式（２）および（３）において、Ｒ７、Ｒ８、Ｒ１４、Ｒ１５、Ｒ１６およびＲ１７は、それぞれ水素原子、炭素原子数１〜８個のアルキル基、フェニル基またはハロゲン原子を表す。
【００３９】
上記一般式（３）において、Ｒ１２は炭素数１〜１０の３価の炭化水素基を表す。価すなわち遊離原子価は炭化水素基のどの部位に存在しても良く、３つの価のうち２つに、上記Ｒ９、Ｒ１０で表される基を介してマレイミド基が、１つに、Ｒ１１で表される基を介してＲ１３で表される炭素原子数４〜３０のアルキル基が結合する。これらの炭化水素基は、直鎖状でも分岐状でも構わない。具体的には、例えばメチリジン基、エチリジン基、プロパニリジン基、ブタニリジン基、１−エタニル−２−イリデン基、１，２，３−プロパントリイル基、１−プロパニル−３−イリデン基、１，２，４−ブタントリイル基、１−ブタニル−４−イリデン基、１，２，５−ペンタントリイル基、１，３，５−ペンタントリイル基、１−ペンタニル−５−イリデン基、
【００４０】
１，２，６−ヘキサントリイル基、１，３，６−ヘキサントリイル基、１−ヘキサニル−６−イリデン基、２−プロパニル−１−イリデン基、２−メチレン−１，３−プロパンジイル基、１−プロパニル−３−イリデン基、３−ブタニル−１−イリデン基、１，２，３−ブタントリイル基、１−ブタニル−２−イリデン基、２−メチル−１−プロパニル−３−イリデン基、２−メチル−１，２，３−プロパントリイル基、２−エチル−１，２，３−プロパントリイル基、２−ブタニル−１−イリデン基、２−ブタニル−３−イリデン基、２−ブタニル−４−イリデン基、の如き３価の非環式炭化水素よりなる基；１，２，３−シクロペンタントリイル基、１，２，５−シクロペンタントリイル基、１−シクロペンチル−２−イリデン基、１−シクロペンチル−３−イリデン基、１，２，３−シクロヘキサントリイル基、１，２，４−シクロヘキサントリイル基、１，３，５−シクロヘキサントリイル基、１−シクロヘキシル−２−イリデン基、１−シクロヘキシル−３−イリデン基、１−シクロヘキシル−４−イリデン基、シクロヘキシルメチリジン基、４−シクロへキシレンメチレン基、１−シクロヘキシル−２−エタニル−１−イリデンの如き環式脂肪族炭化水素を含む３価の炭化水素よりなる基；１，３，５−ベンゼントリイル基、ベンジリジン基、２−フェニル−１，２，３−プロパントリイル基の如き芳香族炭化水素を含む３価の炭化水素よりなる基等が挙げられる。
【００４１】
本発明の光配向膜用材料は、上記一般式（１）で表される、１分子中に少なくとも１個の１光二量化反応により光配向機能を発現する光配向性基と少なくとも２個の重合性マレイミド基を有する単量体と、上記一般式（２）又は（３）で表される、１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基を有する単量体とを含有する。一般にラビング配向膜は、長い分子鎖を有する化合物からなる層が基板面上に設けられており、その長い分子鎖が配向している場合、この層に隣接している液晶分子は、長鎖方向にその長軸を揃えて配向すると考えられている。本発明の光配向膜用材料は、配向および重合処理を行うことで、炭素原子数が４〜３０のアルキル基が基板面に対してある角度をもって配向し、液晶のプレチルト角が得られるものと考えられる。
【００４２】
しかし、一般式（１）の単量体の含有量が少ないと十分な光配向性が得られないため、本発明の光配向膜用材料１００質量部に対して、上記一般式（２）又は（３）で表される、１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基を有する単量体の含有量は、１０〜７０質量部の範囲が好ましく、２０〜６０質量部の範囲が最も好ましい。
【００４３】
次に、本発明の光配向膜用材料を用いて、光配向膜とこれを具備した液晶表示素子を製造する方法の例を述べる。
【００４４】
まず、本発明の光配向膜用材料は適切な溶媒に溶解して用いる。この際、溶媒は特に限定されないが、Ｎ−メチルピロリドン、ジメチルホルムアミド、ブチルセロソルブ、γ−ブチロラクトン、クロロベンゼン、ジメチルスルホキシド、ジメチルアセトアミド、テトラヒドロフラン等が一般的に用いられる。中でもブチルセロソルブ、γ−ブチロラクトンは塗布性が良好で、均一な膜が得られることから、特に好ましい。これらの溶剤は、塗布性や、塗布後に短時間で溶剤を揮発させることを考慮して、２種類以上を混合して用いることもできる。
【００４５】
上記光配向膜用材料の溶液を基板上にスピンコーティング法、印刷法等の方法によって塗布し、乾燥後、重合性マレイミド基の重合および光配向操作を行う。
【００４６】
本発明で使用する基板は、光配向膜に通常用いられる基板であって、熱硬化に耐えうる耐熱性を有するものである。そのような基板としては、ガラス基板が挙げられる。
【００４７】
光や熱による重合性マレイミド基の重合操作は、光二量化反応によって光配合した構造単位に影響を与える恐れがあるため、配向操作に先立って行うことがより好ましい。
【００４８】
重合性マレイミド基の重合は紫外線等の光照射あるいは加熱によって行う。光照射で行う場合は、光配向性基が光配向機能を発現しない波長の光で行うことが好ましい。一方、加熱による重合は、光配向操作の前に行うと、基板に塗布する際に用いた溶媒の乾燥も兼ねることができ、より好ましい。また、重合性マレイミド基を完全に重合させるため、最初に、光照射あるいは加熱で重合を行い、次に光照射により光配向を発現する操作を行った後、更に加熱もしくは重合性マレイミド基の光重合に適した無偏光の光照射を行っても良い。
【００４９】
一方、重合性マレイミド基が重合する光の波長と光配向機能を発現させる光の波長とが近い場合には、重合性マレイミド基の重合と光配向機能を発現させる操作を一回の光照射で同時に行うことが可能である。このような重合性マレイミド基の光重合に用いる照射光は特に限定されないが、紫外線が好ましく使用することができる。照射方法についても特に限定されず、無偏光あるいは直線偏光、楕円偏光などの偏光を使用することができる。
【００５０】
光二量化反応によって光配向を発現させる操作は偏光を照射することによって行う。偏光の波長は、光配向性基が効率よく二量化する波長が選ばれ、可視光線、紫外線等が挙げられるが、中でも紫外線が好ましい。また、偏光は、直線偏光や楕円偏光が多く用いられる。このとき、プレチルトを得るためには、基板に対して斜め方向から偏光や無偏光の照射を十分な照射光量で行うか、基板面に対して垂直方向からの偏光照射に引き続いて、この斜め方向からの照射を行うことが好ましい。
【００５１】
本発明によれば、１分子中に、光二量化反応により光配向機能を発現する少なくとも１個の光配向性基と、少なくとも２個の重合性マレイミド基とを有する単量体、及び、１分子中に炭素原子数４〜３０のアルキル基と、１又は２個のマレイミド基を有する単量体とを含有する光配向膜材料を基板に塗布した後、重合性マレイミド基を重合させ、さらに光配向性基の光二量化反応を生起させることによって光配向膜を得る。本発明で使用するマレイミド化合物は、低分子であるため、溶剤溶解性が高く、塗布が容易であるという特徴を有する。また、長鎖のアルキル基が光配向膜表面に多く分布することで、十分な液晶分子のプレチルト角を得ることができ、さらにマレイミド基が重合し網状構造を有する塗膜となることで、熱や光に対して安定な光配向膜を得ることができる。
また、マレイミド基による重合は重合開始剤を必要としないため、液晶セル作製後に、液晶中に重合開始剤が溶出することがなく、電圧保持率の低下等、液晶表示素子の性能劣化を防ぐことができる。
【００５２】
【実施例】
以下、合成例、実施例および比較例を用いて本発明をさらに詳細に説明するが、本発明は、これらの実施例の範囲に限定されるものではない。
【００５３】
［参考例１］マレイミド酢酸の合成
撹拌機、温度計、滴下ロート、ディーンスターク分留器及び冷却管を備えた容量５００ミリリットルの４つ口フラスコに、トルエン１４０ｇ、ｐ−トルエンスルホン酸一水和物５．２ｇ及びトリエチルアミン２．８ｇを順次仕込み、撹拌しながら無水マレイン酸３０ｇを加えた後、３０℃まで昇温させながら溶解させた。さらにグリシン２３ｇを加えた後、撹拌しながら７０℃で３時間反応させた。トルエン５０ｇ、トリエチルアミン６０ｇを加え、溶媒を加熱還流させて生成する水を除去しながら１時間反応させた。反応混合物から溶媒を留去して得られた残留物に、４ｍｏｌ／ｄｍ3塩酸を加えてｐＨ２に調整した後、加熱−再結晶して、マレイミド酢酸の淡黄色固体７．３ｇを得た。
【００５４】
［参考例２］ ４，４’−ビス（２−ヒドロキシエトキシ）ベンゾフェノンの合成
攪拌機、温度計、滴下ロートおよび冷却管を備えた容量３００ミリリットルの４つ口フラスコに、２−ブロモエタノール６２．５ｇを入れ、氷浴による冷却下、撹拌しながら、Ｎ−メチルピロリドン１００ｇを加えた。これにｐ−トルエンスルホン酸一水和物１０ｍｇを加え、ジヒドロピラン４２．１ｇを約１０分かけて滴下した。氷冷下で２時間撹拌し、さらに室温で２時間撹拌した後、４，４’−ジヒドロキシベンゾフェノン４２．８ｇおよび炭酸カリウム６９．１ｇを加え、１２０℃で３時間反応した。冷却後４００ｍｌの水に反応混合物を加え、４００ｍｌのトルエンで２回抽出し、得られたトルエン層を無水硫酸ナトリウムで乾燥し、エバポレーターで溶媒を留去した。
得られた残渣にメタノール４５０ｇ、水７０ｇ、濃塩酸１．０ｇを加え、室温で一晩撹拌し、生成した沈殿を濾過し、メタノールでよく洗浄した後に乾燥させ、４，４’−ビス（２−ヒドロキシエトキシ）ベンゾフェノン５２ｇを得た。
【００５５】
［参考例３］２，２−ジメチル−５−エチル−５−（ブロモメチル）−１，３−ジオキサン（化合物Ａ）の合成
撹拌機、温度計及び塩化カルシウム乾燥管を付けた冷却管を備えた容量５００ミリリットル４つ口フラスコに、トリメチロールプロパン６７．１ｇ、２,２−ジメトキシプロパン５７．３ｇ、トルエン１００ｇ及びｐ−トルエンスルホン酸一水和物２．９ｇを入れ、６０℃で３時間撹拌した。冷却後、炭酸カリウム ２．５ｇを加え、一晩室温で撹拌した。フラスコ内の固体を濾過で除き、減圧下、溶媒を留去して中間体Ａ８０．６ｇ（液体）を得た。
【００５６】
撹拌機、温度計、窒素導入管及び塩化カルシウム乾燥管を付けた冷却管を備えた容量５００ミリリットル４つ口フラスコに中間体Ａ４３．８ｇ、四臭化炭素１１６．６ｇ及びＮ，Ｎ−ジメチルホルムアミド３００ｍｌを加え、窒素雰囲気下、撹拌しながら氷塩浴で充分に冷却させ、トリフェニルフォスフィン９１．９ｇを少しずつ、液温が０℃を越えないように加えた。トリフェニルフォスフィン添加終了後、３０分氷塩浴中で撹拌し、その後、氷浴中で１時間、室温で２時間撹拌した後、溶媒を５０℃で減圧下、留去した。濃縮された混合物をアセトン−ヘキサン混合溶媒（１／３）２００ｇで３回抽出し、得られた抽出液を、シリカゲルを用いたカラムクロマトグラフィーで精製して目的の化合物Ａ ４７ｇを得た。
（収率 ７９％）
【００５７】
［合成例１］
攪拌機、温度計、ディーンスターク分留器及び冷却管を備えた容量５００ミリリットルの３つ口フラスコに、参考例１で得られたマレイミド酢酸８．８ｇ、参考例２で得た４，４’−ビス（２−ヒドロキシエトキシ）ベンゾフェノン６．１ｇ、ｐ−トルエンスルホン酸一水和物０．４ｇ、ヒドロキノン２０ｍｇ及びトルエン１５０ｍｌを順次仕込み、減圧下、９０℃に加熱して、溶媒を環流させて生成する水を除去しながら１５時間反応させた。反応終了後、反応混合物を熱時濾過し、得られた固体をメタノールでよく洗浄し、乾燥させることにより式（５）
【００５８】
【化９】
【００５９】
［合成例２］
撹拌機、温度計、滴下ロート及び冷却管を備えた容量３００ミリリットル４つ口フラスコに、２−ブロモエタノール６．３ｇをいれ、氷浴による冷却下、撹拌しながらＮ−メチルピロリドン１０ｇを加えた。これにｐ−トルエンスルホン酸一水和物２ｍｇを加え、ジヒドロピラン４．２ｇを約１０分かけて滴下した。氷冷下で２時間撹拌し、さらに室温で２時間撹拌した後、７−ヒドロキシクマリン ８．５ｇおよび炭酸カリウム６．９ｇを加え、１２０℃で３時間反応した。冷却後、１００ｍｌの水に反応混合物を加え、１００ｍｌのトルエンで２回抽出し、得られたトルエン層を無水硫酸ナトリウムで乾燥し、エバポレータで溶媒を留去した。得られた残渣にメタノール４５ｇ、水７ｇ、濃塩酸０．５ｇを加え、室温で一晩撹拌した。溶媒を留去後、トルエン２５０ｇを加えて溶液とし、５０ｇの水で２回洗浄した。
【００６０】
撹拌機、温度計及び冷却管を備えた容量５００ミリリットル３つ口フラスコに、上で得られたトルエン溶液を入れ、参考例３で合成した化合物Ａ１０．５ｇ、テトラブチルアンモニウムブロミド０．９ｇ及び４０％水酸化ナトリウム水溶液８０ｇを加え、撹拌しながら５時間還流した。冷却後、この混合物を分液ロートに移して、水層を分離、除去し、２０ｇの水で３回洗浄した。
得られたトルエン溶液を減圧下で溶媒を留去し、残渣をテトラヒドロフラン１００ｇに溶かし、６％塩酸３０ｇを加え、室温で４時間撹拌した。減圧下、溶媒を留去し、得られた固体を水洗後、濾過、乾燥した。
【００６１】
撹拌機、温度計、ディーンスターク分留器及び冷却管を備えた容量５００ミリリットルの３つ口フラスコに、得られた固体１０．８ｇ、マレイミド酢酸１２．６ｇ、ｐ−トルエンスルホン酸一水和物０．８ｇ、ヒドロキノン４０ｍｇ及びトルエン２００ミリリットルを順次仕込み、減圧下、９０℃に加熱して、溶媒を還流させて生成する水を除去しながら１５時間反応させた。反応終了後、反応液にトルエン２００ミリリットルを加えて希釈し、５０ｇの水で４回洗浄した。このトルエン溶液を硫酸ナトリウムで乾燥後、減圧下溶媒を留去し、得られた固体を、シリカゲルを用いたカラムクロマトグラフィーで精製することにより式（６）、
【００６２】
【化１０】
【００６３】
［合成例３］
攪拌機、温度計、滴下ロート及び冷却管を備えた容量３００ミリリットルの４つ口フラスコに、参考例３で得た化合物Ａ１１．９ｇ、ステアリルアルコール１３．８ｇ、Ｎ−メチルピロリドン４０ｇを加えて撹拌した。均一な溶液になったところで、炭酸カリウム７．１ｇを加え、１５０℃で２時間反応させた、冷却後、減圧下、溶媒を留去し、濃縮した混合物を４リットルの酢酸エチルに溶解した。この溶液を５００ｇの水で３回洗浄し、硫酸ナトリウムで乾燥した後に溶媒を減圧下、留去した。得られた１８．８ｇの固体をテトラヒドロフラン１００ｇに溶かし、６％の塩酸３０ｇを加え、室温で４時間撹拌した。減圧下、溶媒を留去し、得られた固体を水洗後、濾過、乾燥した。
【００６４】
攪拌機、温度計、ディーンスターク分留器および冷却管を備えた容量５００ミリリットルの３つ口フラスコに、得られた固体９．４ｇ、マレイミド酢酸１２．６ｇ、ｐ−トルエンスルホン酸一水和物０．８ｇ、ヒドロキノン４０ｍｇおよびトルエン２００ミリリットルを順次仕込み、減圧下、９０℃に加熱して、溶媒を環流させて、生成する水を除去しながら１５時間反応させた。反応終了後、反応液にトルエン２００ミリリットルを加えて希釈し、５０ｇの水で４回洗浄した。このトルエン溶液を硫酸ナトリウムで乾燥後、減圧下溶媒を留去し、得られた固体を、シリカゲルを用いたカラムクロマトグラフィーで精製することにより式（７）
【００６５】
【化１１】
【００６６】
［実施例１］
合成例１で得られたマレイミド誘導体（５）５０質量部およびラウリルマレイミド（大八化学製）５０質量部を、Ｎ，Ｎ−ジメチルホルムアミドに溶かして、固形分濃度５％溶液とし、これを０．４５μｍのフィルターで濾過し、光配向膜用材料溶液とした。得られた光配向膜用材料溶液を、スピンコーターにてＩＴＯ電極付ガラス基板に均一に塗布し、１９０℃で１時間加熱し、溶媒の乾燥およびマレイミド基の熱重合による硬化を行った。次に、得られた塗膜表面に超高圧水銀ランプを用い、波長３１３ｎｍ、エネルギー密度２０ｍＷ／ｃｍ２の紫外線の直線偏光を５０秒間照射した。続いて、波長３１３ｎｍ、エネルギー密度４０ｍＷ／ｃｍ２の無偏光の紫外光を、先に照射された直線偏光の偏光方向と垂直な方向で、かつ基板面から４５°の角度から１２０秒間照射し、光配向膜を作成した。
【００６７】
上記の方法で得られた光配向膜付基板の周囲に直径５μｍのスチレンビーズを含んだ熱硬化性接着剤を液晶注入口を残して塗布し、もう１枚の光配向膜付基板を配向面が相対し、かつ先に照射した直線偏光の偏光方向が一致するように重ね合わせて圧着し、接着剤を１５０℃で９０分かけて硬化させた。次いで、液晶注入口よりネマチック液晶組成物ＥＬＳ−００１（大日本インキ化学工業（株）製）を加温しながら等方相の状態で真空注入により充填を行った後、エポキシ系接着剤で液晶注入口を封止した。このようにして得られた液晶素子を偏光顕微鏡で観察し、液晶の配向を確認した。このとき、配向欠陥によるディスクリネーションは認められなかった。
次に、この液晶素子の液晶のプレチルト角を回転結晶法により測定した結果、プレチルト角は３．２°であった。また、液晶素子を３ヶ月間、自然光下、室温で放置してもプレチルト角には変化は認められなかった。
【００６８】
［実施例２］
合成例２で得られたマレイミド誘導体（６）５０質量部およびラウリルマレイミド５０質量部を、Ｎ，Ｎ−ジメチルホルムアミドに溶かして、固形分濃度５％溶液とし、これを０．４５μｍのフィルターで濾過し、光配向膜用材料溶液とした。これを、ガラス基板上に実施例１と同様の方法で塗布、加熱による乾燥および熱重合を行い、さらに紫外光の照射を行った。さらに、実施例１と同様の方法で液晶セルの作製、液晶の注入を行うことで液晶素子を作製した。このようにして得られた液晶表示素子を偏光顕微鏡で観察し、液晶の配向を確認した。このとき、配向欠陥によるディスクリネーションは認められなかった。
次に、この液晶素子の液晶のプレチルト角を回転結晶法により測定した結果、プレチルト角は３．５°であった。また、液晶素子を３ヶ月間、自然光下、室温で放置してもプレチルト角には変化は認められなかった。
【００６９】
［実施例３］
合成例２で得られたマレイミド誘導体（６）５０質量部、および合成例３で得られたマレイミド誘導体（７）５０質量部をＮ，Ｎ−ジメチルホルムアミドに溶かして、固形分濃度５％溶液とし、これを０．４５μｍのフィルターで濾過し、光配向膜用材料溶液とした。これを、ガラス基板上に実施例１と同様の方法で塗布、加熱による乾燥および熱重合を行い、さらに紫外光の照射を行った。さらに、実施例１と同様の方法で液晶セルの作製、液晶の注入を行うことで液晶素子を作製した。このようにして得られた液晶表示素子を偏光顕微鏡で観察し、液晶の配向を確認した。このとき、配向欠陥によるディスクリネーションは認められなかった。
次に、この液晶素子の液晶のプレチルト角を回転結晶法により測定した結果、プレチルト角は４．０°であった。また、液晶素子を３ヶ月間、自然光下、室温で放置してもプレチルト角には変化は認められなかった。
【００７０】
［比較例］
式（８）で表される、４，４−ジフェニルメタンビスマレイミド（ケイ・アイ化成（株）製）、
【００７１】
【化１２】
をＮ，Ｎ−ジメチルホルムアミドに溶かして、固形分濃度５％溶液とし、これを０．４５μｍのフィルターで濾過し、光配向膜用材料溶液とした。これを、ガラス基板上に実施例１と同様の方法で塗布、加熱による乾燥および熱重合を行い、さらに紫外光の照射を行った。さらに、実施例１と同様の方法で液晶セルの作製、液晶の注入を行うことで液晶素子を作製した。このようにして得られた液晶素子を偏光顕微鏡で観察したところ、液晶の配向が確認された。
次に、この液晶素子の液晶のプレチルト角を実施例１と同様に回転結晶法にとって測定を行ったが、プレチルト角はほとんど観測されなかった。
【００７３】
【発明の効果】
本発明の光配向膜用材料を使用した光配向膜用材料を用いることにより、生産性に優れるとともに、良好な液晶配向性を示し、十分な液晶分子のプレチルト角が得られ、かつこのプレチルト角が熱的、経時的に十分な安定性を有する液晶表示素子用の光配向膜を得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a photo-alignment film used in a liquid crystal display device, and more specifically, a photo-alignment film forming material capable of aligning liquid crystal molecules without being rubbed by irradiation with light, and the material. The present invention relates to a photo-alignment film, a manufacturing method thereof, and a liquid crystal display device using the photo-alignment film.
[0002]
[Prior art]
In the liquid crystal display device, the state of the molecular arrangement of the liquid crystal is changed by the action of an electric field or the like, and the change in the optical characteristics accompanying this is used for display. In many cases, the liquid crystal is used in a state of being sandwiched between two substrates. Here, in order to align liquid crystal molecules in a specific direction, an alignment process is performed on the inside of the substrate.
[0003]
Usually, for the orientation treatment, a method called rubbing is used in which a polymer film such as polyimide is provided on a substrate such as glass and is rubbed with a cloth or the like in one direction. However, since this method generates static electricity and dust in the manufacturing process, a cleaning process after the alignment process is required. In particular, TFT-type liquid crystal cells that are frequently used in recent years may generate static electricity due to friction during rubbing, and the TFT elements previously provided on the substrate may be destroyed, which causes a decrease in yield in manufacturing. It is also.
[0004]
On the other hand, in recent years, liquid crystal alignment control techniques that do not perform rubbing, such as oblique vapor deposition, LB (Langmuir-Blodget) film method, photolithography method, photo-alignment method, and the like, have attracted attention. In particular, the photo-alignment method that irradiates the coating film provided on the substrate with polarized light to produce liquid crystal alignment is simple and does not require a washing step after the alignment treatment, so Research is underway.
This photo-alignment method is a photo-isomerization reaction that develops a photo-alignment function in organic molecules, such as a photoisomerization reaction such as an azo group, a photodimerization reaction such as a cinnamoyl group, a coumarin group, or a chalcone group, or a light such as a benzophenone group. The thing using photolysis reaction etc., such as bridge | crosslinking and a polyimide resin, has been reported. In these cases, a polymer material is used so that a uniform film can be obtained when applied to a substrate such as glass, and a photo-alignment group is often introduced into a side chain or main chain. In some cases, molecules having photo-alignment properties are used as guest molecules and dispersed in a host compound made of a polymer compound.
[0005]
However, many photo-alignment film materials using these polymer materials have a problem that their liquid crystal alignment ability and heat resistance are not sufficient. For example, in the manufacturing process of a liquid crystal display element, when a liquid crystal alignment film is formed on a substrate and then assembled into a liquid crystal cell, heat treatment is performed for the purpose of curing the sealant. At this time, the liquid crystal alignment film has sufficient heat resistance. Otherwise, the liquid crystal alignment ability deteriorates.
In order to improve heat resistance, a polymer material having a crosslinked structure may be used, but many of the polymer compounds having a crosslinked structure have poor solubility in a solvent and may be used when applied to a substrate. The kind of solvent that can be produced is remarkably limited, which is not preferable for practical use.
[0006]
As a method for overcoming such drawbacks and stably obtaining the liquid crystal alignment ability of the photo-alignment film, a method in which a polymerizable monomer having a photo-alignment group is coated on a substrate and then polymerized is disclosed in JP-A-2001-48904. It is disclosed in the publication. However, it is necessary to add a polymerization initiator to heat or photopolymerize the monomer. Since this polymerization initiator is a low molecular weight compound, even after polymerization, after a long period of time, the polymerization initiator remaining in the liquid crystal layer in the cell diffuses, and the characteristics as a liquid crystal display element such as voltage holding There is a risk of deteriorating the rate. Another problem is that the polymerization must be carried out in a nitrogen atmosphere in order to prevent polymerization inhibition by oxygen.
[0007]
A maleimide compound is an example of a compound that does not require a polymerization initiator and can undergo a photopolymerization reaction in air. As such, JP-A-2001-122981 discloses a photo-alignment film material using an aromatic compound having a polymerizable maleimide group, but the photo-alignment ability by this compound is not yet sufficient. .
[0008]
On the other hand, one of the characteristics required for the liquid crystal alignment film is that an appropriate pretilt angle is given to the liquid crystal molecules. In particular, in a TN or STN liquid crystal display element, if the pretilt angle is small, domain-like defects having different twist directions may occur, or linear alignment defects called disclinations may occur.
A conventional rubbing film can easily obtain a pretilt angle of liquid crystal molecules by performing a rubbing treatment in a certain direction. However, in the case of a photo-alignment film, it is known that a pretilt can be obtained by irradiating linearly polarized light or non-polarized light from an oblique direction onto a photo-alignment film made of a polymer film having a cinnamic acid derivative or a coumarin derivative in the side chain. However, the obtained pretilt angle is small, and there are problems such as heating or instability with time. Moreover, even if it is the material for photo-alignment films using the said maleimide compound, sufficient pretilt angle cannot be obtained and it has a problem in practical use.
[0009]
As described above, it has excellent liquid crystal alignment ability, excellent productivity, heat resistance, long-term stability, sufficient pretilt angle, and good liquid crystal element characteristics. The material is not yet available.
[0010]
[Problems to be solved by the invention]
The problems to be solved by the present invention are high solubility in a solvent at the time of coating, further exhibiting good liquid crystal alignment properties, a sufficient pretilt angle of liquid crystal molecules is obtained, and this pretilt angle is thermally and time-dependent. It is an object of the present invention to provide a photo-alignment film for a liquid crystal display element having sufficient stability.
[0011]
[Means for Solving the Problems]
That is, in order to solve the above problems, the present invention provides (a) at least one photoalignable group that exhibits a photoalignment function by a photodimerization reaction in one molecule, and at least two polymerizable maleimide groups. And (b) a monomer having an alkyl group having 4 to 30 carbon atoms and one or two maleimide groups in one molecule but having no photo-alignment group An optical alignment film material is provided.
[0012]
In order to solve the above-mentioned problems, the present invention provides: (a) a single molecule having a photoalignment group that exhibits a photoalignment function by at least one photodimerization reaction and at least two polymerizable maleimide groups in one molecule. And (b) a copolymer of a monomer having an alkyl group having 4 to 30 carbon atoms and one or two maleimide groups in one molecule but having no photo-alignment group And a photo-alignment function expressed by photodimerization of the photo-alignment group of the monomer (a) and polymerization of the polymerizable maleimide group of the monomers (a) and (b) Provided is a photo-alignment film having a crosslinked structure.
[0013]
In order to solve the above-mentioned problems, the present invention applies the photoalignment film material described above onto a substrate, and heats the coating film to cause a thermal polymerization reaction of the polymerizable maleimide group, thereby crosslinking. A method for producing a photo-alignment film is provided, in which a photo-dimerization reaction of the structural unit is caused by forming a polymer film and irradiating the polymer film with light so that the polymer film exhibits a photo-alignment function. .
[0014]
In order to solve the above problems, the present invention provides a liquid crystal display element having a structure in which a liquid crystal is sandwiched between two substrates having an alignment film on the inner side, wherein (a) the alignment film is at least in one molecule. A monomer having a photo-alignment group that exhibits a photo-alignment function by one photodimerization reaction and at least two polymerizable maleimide groups, and (b) an alkyl group having 4 to 30 carbon atoms in one molecule And a copolymer of a monomer having one or two maleimide groups, a photo-alignment function expressed by photodimerization of the photo-alignable group and a crosslinked structure generated by polymerization of the polymerizable maleimide group A liquid crystal display element which is a photo-alignment film having
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Monomer having at least one photo-alignable group that expresses a photo-alignment function by a photodimerization reaction and at least two polymerizable maleimide groups in one molecule used in the photo-alignment film material of the present invention The photo-alignment group that develops the photo-alignment function by the photo-dimerization reaction is a functional group that causes a photo-reaction by the anisotropic dimerization reaction caused by polarized light irradiation and can obtain orientation. Although not particularly limited, a structural unit having at least one double bond represented by C = C and C = O (excluding a double bond forming an aromatic ring) is particularly preferably used.
[0016]
Examples of the basic structure of the photoalignable group that exhibits the photoalignment function by these photodimerization reactions include the following.
Examples of the photoalignable group that exhibits a photoalignment function by a photodimerization reaction having a C═C bond include structures such as a polyene skeleton, a stilbene skeleton, a stilbazole skeleton, a stilbazolium skeleton, a cinnamoyl skeleton, a hemithioindigo skeleton, and a chalcone skeleton. Groups. Examples of the photoalignable group that exhibits a photoalignment function by a photodimerization reaction having a C═O bond include groups having a structure such as a benzophenone skeleton and a coumarin skeleton.
[0017]
Among them, a photo-alignment group selected from the group of 1 to 4 valent groups consisting of a benzophenone skeleton, a cinnamoyl skeleton, a chalcone skeleton, and a coumarin skeleton is preferable, and specifically represented by the following structure. Of course, these structures may have substituents such as alkyl groups, alkoxy groups, aryl groups, allyloxy groups, cyano groups, alkoxycarbonyl groups, hydroxyl groups, sulfonic acid groups, and halogenated alkyl groups.
[0018]
[Formula 4]
Specifically, a monomer having a photoalignment group that exhibits a photoalignment function by at least one photodimerization reaction and at least two polymerizable maleimide groups in one molecule is represented by the general formula (1).
[Chemical formula 5]
[0020]
[Chemical 6]
[0021]
In the general formulas (1) and (4), R 1 Represents at least one group selected from the group consisting of a linear or branched alkylene group having 1 to 30 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, an arylalkylene group and a cycloalkylalkylene group.
[0022]
R 1 Specific examples of the group representing are, for example, methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group. A linear alkylene group such as a dodecamethylene group; 1-methylethylene group, 1-methyl-trimethylene group, 2-methyl-trimethylene group, 1-methyl-tetramethylene group, 2-methyl-tetramethylene group, 1- An alkylene group having a branched alkyl group such as methyl-pentamethylene group, 2-methyl-pentamethylene group, 3-methylpentamethylene group, neopentyl group;
[0023]
Cycloalkylene groups such as cyclopentylene group and cyclohexylene group; aryl groups in the main chain or side chain such as benzylene group, 2,2-diphenyl-trimethylene group, 1-phenyl-ethylene group, 1-phenyl-tetraethylene group Cycloalkyl-alkylene groups having a cycloalkyl group in the main chain or side chain such as a cyclohexylmethylene group, a 1-cyclohexyl-ethylene group, and a 1-cyclohexyl-tetraethylene group. Among these, an alkylene group having 1 to 30 carbon atoms or a cycloalkylene group having 3 to 12 carbon atoms is preferable.
[0024]
R 1 May be a group in which 2 to 5 groups mentioned above are linked by a single bond, an ester bond, an ether bond or a urethane bond.
[0025]
Examples of such linked groups include a group composed of (poly) ether in which at least two alkylene groups are bonded by an ether bond, and at least two alkylene groups bonded by an ester bond (poly). A group composed of an ester, a group composed of (poly) urethane in which at least two alkylene groups are bonded by a urethane bond, and a (poly) ether (poly) ol in which at least two alkylene groups are bonded by an ether bond And a group composed of (poly) carboxylic acid {(poly) ether (poly) ol} ester obtained by esterification of (poly) carboxylic acid.
[0026]
In the general formulas (1) and (4), R 2 Represents a photo-alignment group that exhibits a photo-alignment function by the above-described photodimerization reaction.
[0027]
In the compounds represented by the general formulas (1) and (4), these R 2 The photo-alignment group that expresses the photo-alignment function by the photodimerization reaction represented by 1 And a group represented by a single bond, an ester bond or a urethane bond. The number of bonds of photo-alignable groups that express the photo-alignment function by the photodimerization reaction is the same as the number of polymerizable maleimide groups in one molecule, but the maleimide derivatives used in the present invention are a plurality of polymerizable maleimides. Since it has groups, the number is preferably in the range of 2 to 4. Among them, the polymerization of the polymerizable maleimide group easily proceeds to form a stable maleimide polymer, and the amount of light energy required to develop the photo-alignment group that exhibits the photo-alignment function is relatively small. Since it is small, it is preferable that the number of bonds of the photoalignable group that exhibits the photoalignment function by the photodimerization reaction is two.
[0028]
In the general formulas (1) and (4), R 3 And R 4 Each independently represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a phenyl group or a halogen atom.
[0029]
In the general formula (1), n represents an integer of 2 to 4. Among them, the polymerization of the polymerizable maleimide group easily proceeds to form a stable maleimide polymer, and since the amount of light energy necessary to develop the photo-alignment function of the photo-alignment group is relatively small, n A compound represented by the general formula (4) in which is 2 is particularly preferred.
[0030]
The monomer having an alkyl group having 4 to 30 carbon atoms and one or two maleimide groups in one molecule used in the present invention is specifically represented by the general formula (2) or (3). expressed.
[0031]
[Chemical 7]
[Chemical 8]
In the general formulas (2) and (3), R 5 , R 9 , R 10 And R 11 Represents at least one group selected from the group consisting of a linear or branched alkylene group having 1 to 10 carbon atoms, a cycloalkylene group having 3 to 12 carbon atoms, an arylalkylene group and a cycloalkylalkylene group.
[0034]
These R 5 , R 9 , R 10 And R 11 Specific examples of are, for example, methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group. Linear alkylene group such as 1-methylethylene group, 1-methyl-trimethylene group, 2-methyl-trimethylene group, 1-methyl-tetramethylene group, 2-methyltetramethylene group, 1-methyl-pentamethylene An alkylene group having a branched alkyl group such as a group, 2-methyl-pentamethylene group, 3-methyl-pentamethylene group, 2,2-dimethyl-trimethylene group;
[0035]
Cycloalkylene groups such as cyclopentylene group and cyclohexylene group; aryl groups in the main chain or side chain such as benzylene group, 2,2-diphenyl-trimethylene group, 1-phenyl-ethylene group, 1-phenyl-tetraethylene group And arylalkylene groups having a cycloalkyl-alkylene group having a cycloalkyl group in the main chain or side difference, such as a cyclohexylmethylene group, a 1-cyclohexyl-ethylene group, and a 1-cyclohexyl-tetraethylene group. Among these, an alkylene group having 1 to 10 carbon atoms or a cycloalkylene group having 3 to 12 carbon atoms is preferable.
[0036]
R 5 , R 9 , R 10 And R 11 May be a group in which 2 to 5 groups mentioned above are linked by a single bond, an ester bond, an ether bond or a urethane bond. Examples of such linked groups include a group composed of (poly) ether in which at least two alkylene groups are bonded by an ether bond, and at least two alkylene groups bonded by an ester bond (poly). A group composed of an ester, a group composed of (poly) urethane in which at least two alkylene groups are bonded by a urethane bond, and a (poly) ether (poly) ol in which at least two alkylene groups are bonded by an ether bond And a group composed of (poly) carboxylic acid {(poly) ether (poly) ol} ester obtained by esterification of (poly) carboxylic acid.
[0037]
In the general formulas (2) and (3), R 6 And R 13 Represents an alkyl group having 4 to 30 carbon atoms. Specific examples include a stearyl group, a lauryl group, a tridecyl group, a myristyl group, a pentadecyl group, a cetyl group, a heptadecyl group, and a nonadecyl group. Note that these alkyl groups may have an alkyl group as a substituent.
[0038]
In the general formulas (2) and (3), R 7 , R 8 , R 14 , R 15 , R 16 And R 17 Each represents a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, a phenyl group or a halogen atom.
[0039]
In the general formula (3), R 12 Represents a trivalent hydrocarbon group having 1 to 10 carbon atoms. The valence or free valence may be present at any part of the hydrocarbon group, and two of the three 9 , R 10 Via the group represented by 11 Through a group represented by 13 An alkyl group having 4 to 30 carbon atoms represented by These hydrocarbon groups may be linear or branched. Specifically, for example, a methylidyne group, an ethylidyl group, a propanilidine group, a butanilysine group, a 1-ethanyl-2-ylidene group, a 1,2,3-propanetriyl group, a 1-propanyl-3-ylidene group, 1,2 , 4-butanetriyl group, 1-butanyl-4-ylidene group, 1,2,5-pentanetriyl group, 1,3,5-pentanetriyl group, 1-pentanyl-5-ylidene group,
[0040]
1,2,6-hexanetriyl group, 1,3,6-hexanetriyl group, 1-hexanyl-6-ylidene group, 2-propanyl-1-ylidene group, 2-methylene-1,3-propanediyl Group, 1-propanyl-3-ylidene group, 3-butanyl-1-ylidene group, 1,2,3-butanetriyl group, 1-butanyl-2-ylidene group, 2-methyl-1-propanyl-3-ylidene group 2-methyl-1,2,3-propanetriyl group, 2-ethyl-1,2,3-propanetriyl group, 2-butanyl-1-ylidene group, 2-butanyl-3-ylidene group, 2 A group consisting of a trivalent acyclic hydrocarbon such as -butanyl-4-ylidene group; 1,2,3-cyclopentanetriyl group, 1,2,5-cyclopentanetriyl group, 1-cyclopentyl- 2-ylidene group, 1- Clopentyl-3-ylidene group, 1,2,3-cyclohexanetriyl group, 1,2,4-cyclohexanetriyl group, 1,3,5-cyclohexanetriyl group, 1-cyclohexyl-2-ylidene group, 1 Cycloaliphatic hydrocarbons such as -cyclohexyl-3-ylidene group, 1-cyclohexyl-4-ylidene group, cyclohexylmethylidine group, 4-cyclohexyleneethylene group, 1-cyclohexyl-2-ethanyl-1-ylidene A group comprising a trivalent hydrocarbon containing; a trivalent carbon containing an aromatic hydrocarbon such as 1,3,5-benzenetriyl group, benzylidine group, 2-phenyl-1,2,3-propanetriyl group Examples include groups consisting of hydrogen.
[0041]
The photoalignment film material of the present invention comprises a photoalignment group that expresses a photoalignment function by at least one 1-dimerization reaction in one molecule and at least two polymerizations represented by the general formula (1). A monomer having a reactive maleimide group, an alkyl group having 4 to 30 carbon atoms and one or two maleimide groups in one molecule represented by the general formula (2) or (3). Containing a polymer. In general, a rubbing alignment film is provided with a layer made of a compound having a long molecular chain on the substrate surface. When the long molecular chain is aligned, the liquid crystal molecules adjacent to this layer are aligned in the long chain direction. It is considered that the long axes are aligned to the same orientation. The material for a photo-alignment film of the present invention is obtained by aligning an alkyl group having 4 to 30 carbon atoms with a certain angle with respect to the substrate surface by performing alignment and polymerization treatment, and obtaining a pretilt angle of liquid crystal. Conceivable.
[0042]
However, if the content of the monomer of the general formula (1) is small, sufficient photo-alignment property cannot be obtained. Therefore, with respect to 100 parts by mass of the photo-alignment film material of the present invention, the general formula (2) or The content of the monomer represented by (3) having an alkyl group having 4 to 30 carbon atoms and one or two maleimide groups in one molecule is preferably in the range of 10 to 70 parts by mass, A range of 20 to 60 parts by mass is most preferable.
[0043]
Next, an example of a method for producing a photoalignment film and a liquid crystal display device having the photoalignment film using the photoalignment film material of the present invention will be described.
[0044]
First, the photo-alignment film material of the present invention is used after being dissolved in a suitable solvent. At this time, the solvent is not particularly limited, but N-methylpyrrolidone, dimethylformamide, butyl cellosolve, γ-butyrolactone, chlorobenzene, dimethyl sulfoxide, dimethylacetamide, tetrahydrofuran and the like are generally used. Of these, butyl cellosolve and γ-butyrolactone are particularly preferable since they have good coatability and a uniform film can be obtained. These solvents can be used in combination of two or more in consideration of coating properties and volatilization of the solvent in a short time after coating.
[0045]
The solution of the photoalignment film material is applied onto a substrate by a method such as spin coating or printing, and after drying, polymerization of polymerizable maleimide groups and photoalignment operation are performed.
[0046]
The substrate used in the present invention is a substrate usually used for a photo-alignment film, and has heat resistance that can withstand thermosetting. Examples of such a substrate include a glass substrate.
[0047]
Since the polymerization operation of the polymerizable maleimide group by light or heat may affect the structural unit photomixed by the photodimerization reaction, it is more preferably performed prior to the alignment operation.
[0048]
Polymerization of the polymerizable maleimide group is carried out by irradiation with light such as ultraviolet rays or heating. When performing by light irradiation, it is preferable to carry out with the light of the wavelength which a photo-alignment group does not express a photo-alignment function. On the other hand, when the polymerization by heating is performed before the photo-alignment operation, it can also serve as drying of the solvent used for application to the substrate, and is more preferable. In addition, in order to completely polymerize the polymerizable maleimide group, first, the polymerization is performed by light irradiation or heating, and then the operation of expressing the photo-alignment by light irradiation is performed, and then the light of the polymerizable maleimide group is further heated. Non-polarized light irradiation suitable for polymerization may be performed.
[0049]
On the other hand, when the wavelength of light for polymerizing the polymerizable maleimide group is close to the wavelength of light for developing the photo-alignment function, the polymerization of the polymerizable maleimide group and the operation for expressing the photo-alignment function can be performed with a single light irradiation. It is possible to do it at the same time. Irradiation light used for photopolymerization of such a polymerizable maleimide group is not particularly limited, but ultraviolet rays can be preferably used. The irradiation method is not particularly limited, and polarized light such as non-polarized light, linearly polarized light, and elliptically polarized light can be used.
[0050]
The operation for expressing the photo-alignment by the photodimerization reaction is performed by irradiating polarized light. As the wavelength of the polarized light, a wavelength at which the photo-alignment group efficiently dimerizes is selected, and examples thereof include visible light and ultraviolet light. Among them, ultraviolet light is preferable. As the polarized light, linearly polarized light or elliptically polarized light is often used. At this time, in order to obtain a pretilt, the substrate is irradiated with polarized or non-polarized light from an oblique direction with a sufficient amount of irradiation, or following the polarized irradiation from a direction perpendicular to the substrate surface, this oblique direction It is preferable to perform irradiation from.
[0051]
According to the present invention, in one molecule, a monomer having at least one photoalignable group that exhibits a photoalignment function by a photodimerization reaction and at least two polymerizable maleimide groups, and one molecule A photo-alignment film material containing an alkyl group having 4 to 30 carbon atoms and a monomer having 1 or 2 maleimide groups is applied to the substrate, and then polymerizable maleimide groups are polymerized, A photo-alignment film is obtained by causing a photodimerization reaction of the orientation group. Since the maleimide compound used in the present invention has a low molecular weight, it has the characteristics of high solvent solubility and easy application. In addition, a large amount of long-chain alkyl groups are distributed on the surface of the photo-alignment film, so that a sufficient pretilt angle of liquid crystal molecules can be obtained, and further, a maleimide group is polymerized to form a coating film having a network structure. In addition, a photo-alignment film that is stable against light can be obtained.
In addition, since polymerization with a maleimide group does not require a polymerization initiator, the polymerization initiator does not elute into the liquid crystal after the production of the liquid crystal cell, thereby preventing performance deterioration of the liquid crystal display element such as a decrease in voltage holding ratio. Can do.
[0052]
【Example】
EXAMPLES Hereinafter, although this invention is demonstrated further in detail using a synthesis example, an Example, and a comparative example, this invention is not limited to the range of these Examples.
[0053]
[Reference Example 1] Synthesis of maleimidoacetic acid
In a 500 ml four-necked flask equipped with a stirrer, thermometer, dropping funnel, Dean-Stark fractionator and condenser, 140 g of toluene, 5.2 g of p-toluenesulfonic acid monohydrate and 2.8 g of triethylamine Were added in order, 30 g of maleic anhydride was added with stirring, and then dissolved while heating up to 30 ° C. Further, 23 g of glycine was added, and the mixture was reacted at 70 ° C. for 3 hours with stirring. 50 g of toluene and 60 g of triethylamine were added, and the reaction was carried out for 1 hour while removing the water produced by heating and refluxing the solvent. The residue obtained by distilling off the solvent from the reaction mixture was 4 mol / dm. Three Hydrochloric acid was added to adjust the pH to 2, followed by heating and recrystallization to obtain 7.3 g of a pale yellow solid of maleimidoacetic acid.
[0054]
Reference Example 2 Synthesis of 4,4′-bis (2-hydroxyethoxy) benzophenone
62.5 g of 2-bromoethanol was placed in a four-necked flask with a capacity of 300 ml equipped with a stirrer, thermometer, dropping funnel and condenser, and 100 g of N-methylpyrrolidone was added with stirring under cooling in an ice bath. It was. To this was added 10 mg of p-toluenesulfonic acid monohydrate, and 42.1 g of dihydropyran was added dropwise over about 10 minutes. After stirring for 2 hours under ice-cooling and further stirring for 2 hours at room temperature, 42.8 g of 4,4′-dihydroxybenzophenone and 69.1 g of potassium carbonate were added and reacted at 120 ° C. for 3 hours. After cooling, the reaction mixture was added to 400 ml of water and extracted twice with 400 ml of toluene. The obtained toluene layer was dried over anhydrous sodium sulfate, and the solvent was distilled off with an evaporator.
To the obtained residue, 450 g of methanol, 70 g of water, and 1.0 g of concentrated hydrochloric acid were added, and the mixture was stirred overnight at room temperature. The resulting precipitate was filtered, washed well with methanol, dried, and then 4,4′-bis (2 -Hydroxyethoxy) benzophenone 52 g was obtained.
[0055]
Reference Example 3 Synthesis of 2,2-dimethyl-5-ethyl-5- (bromomethyl) -1,3-dioxane (Compound A)
To a 500 ml four-necked flask equipped with a stirrer, a thermometer and a condenser tube equipped with a calcium chloride drying tube, 67.1 g of trimethylolpropane, 57.3 g of 2,2-dimethoxypropane, 100 g of toluene and p-toluene 2.9 g of sulfonic acid monohydrate was added and stirred at 60 ° C. for 3 hours. After cooling, 2.5 g of potassium carbonate was added and stirred overnight at room temperature. The solid in the flask was removed by filtration, and the solvent was distilled off under reduced pressure to obtain 80.6 g of Intermediate A (liquid).
[0056]
Intermediate A 43.8 g, carbon tetrabromide 116.6 g and N, N-dimethylformamide were added to a 500 ml four-necked flask equipped with a stirrer, thermometer, nitrogen inlet tube and condenser tube equipped with a calcium chloride drying tube. 300 ml was added, and the mixture was sufficiently cooled in an ice-salt bath with stirring under a nitrogen atmosphere, and 91.9 g of triphenylphosphine was added little by little so that the liquid temperature did not exceed 0 ° C. After completion of the addition of triphenylphosphine, the mixture was stirred in an ice salt bath for 30 minutes, and then stirred in an ice bath for 1 hour and at room temperature for 2 hours, and then the solvent was distilled off at 50 ° C. under reduced pressure. The concentrated mixture was extracted three times with 200 g of acetone-hexane mixed solvent (1/3), and the resulting extract was purified by column chromatography using silica gel to obtain 47 g of the desired compound A.
(Yield 79%)
[0057]
[Synthesis Example 1]
Into a 500 ml three-necked flask equipped with a stirrer, a thermometer, a Dean-Stark fractionator and a condenser tube, 8.8 g of maleimide acetic acid obtained in Reference Example 1 and 4,4′- obtained in Reference Example 2 were added. 6.1 g of bis (2-hydroxyethoxy) benzophenone, 0.4 g of p-toluenesulfonic acid monohydrate, 20 mg of hydroquinone and 150 ml of toluene are sequentially added, heated to 90 ° C. under reduced pressure, and the solvent is refluxed. The reaction was allowed to proceed for 15 hours while removing the water. After completion of the reaction, the reaction mixture is filtered while hot, and the resulting solid is washed thoroughly with methanol and dried to obtain the formula (5).
[0058]
[Chemical 9]
[0059]
[Synthesis Example 2]
To a 300 ml four-necked flask equipped with a stirrer, thermometer, dropping funnel and condenser, 6.3 g of 2-bromoethanol was added, and 10 g of N-methylpyrrolidone was added with stirring under cooling in an ice bath. . To this, 2 mg of p-toluenesulfonic acid monohydrate was added, and 4.2 g of dihydropyran was added dropwise over about 10 minutes. After stirring for 2 hours under ice-cooling and further stirring for 2 hours at room temperature, 8.5 g of 7-hydroxycoumarin and 6.9 g of potassium carbonate were added and reacted at 120 ° C. for 3 hours. After cooling, the reaction mixture was added to 100 ml of water and extracted twice with 100 ml of toluene. The obtained toluene layer was dried over anhydrous sodium sulfate, and the solvent was distilled off with an evaporator. To the obtained residue, 45 g of methanol, 7 g of water and 0.5 g of concentrated hydrochloric acid were added and stirred overnight at room temperature. After distilling off the solvent, 250 g of toluene was added to form a solution, which was washed twice with 50 g of water.
[0060]
The toluene solution obtained above was put into a 500 ml three-necked flask equipped with a stirrer, a thermometer and a condenser tube, and 10.5 g of compound A synthesized in Reference Example 3, 0.9 g of tetrabutylammonium bromide and 40 A 80% aqueous sodium hydroxide solution was added, and the mixture was refluxed for 5 hours with stirring. After cooling, the mixture was transferred to a separatory funnel, the aqueous layer was separated and removed, and washed with 20 g of water three times.
The obtained toluene solution was evaporated under reduced pressure, the residue was dissolved in 100 g of tetrahydrofuran, 30 g of 6% hydrochloric acid was added, and the mixture was stirred at room temperature for 4 hours. The solvent was distilled off under reduced pressure, and the resulting solid was washed with water, filtered and dried.
[0061]
In a 500 ml three-necked flask equipped with a stirrer, thermometer, Dean-Stark fractionator and condenser, the obtained solid 10.8 g, maleimidoacetic acid 12.6 g, p-toluenesulfonic acid monohydrate 0.8 g, 40 mg of hydroquinone and 200 ml of toluene were sequentially added, and the mixture was heated to 90 ° C. under reduced pressure to react for 15 hours while refluxing the solvent to remove the generated water. After completion of the reaction, the reaction solution was diluted with 200 ml of toluene and washed with 50 g of water four times. The toluene solution was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and the obtained solid was purified by column chromatography using silica gel to obtain the formula (6),
[0062]
Embedded image
[0063]
[Synthesis Example 3]
To a 300 ml four-necked flask equipped with a stirrer, thermometer, dropping funnel and condenser, the compound A 11.9 g obtained in Reference Example 3, 13.8 g stearyl alcohol and 40 g N-methylpyrrolidone were added and stirred. . When the solution became uniform, 7.1 g of potassium carbonate was added and reacted at 150 ° C. for 2 hours. After cooling, the solvent was distilled off under reduced pressure, and the concentrated mixture was dissolved in 4 liters of ethyl acetate. This solution was washed with 500 g of water three times and dried over sodium sulfate, and then the solvent was distilled off under reduced pressure. The obtained 18.8 g of solid was dissolved in 100 g of tetrahydrofuran, 30 g of 6% hydrochloric acid was added, and the mixture was stirred at room temperature for 4 hours. The solvent was distilled off under reduced pressure, and the resulting solid was washed with water, filtered and dried.
[0064]
Into a 500 ml three-necked flask equipped with a stirrer, a thermometer, a Dean-Stark fractionator and a condenser tube, 9.4 g of the obtained solid, 12.6 g of maleimidoacetic acid, p-toluenesulfonic acid monohydrate 0 .8 g, hydroquinone 40 mg, and toluene 200 ml were sequentially added, heated to 90 ° C. under reduced pressure, and the solvent was refluxed to react for 15 hours while removing generated water. After completion of the reaction, the reaction solution was diluted with 200 ml of toluene and washed with 50 g of water four times. The toluene solution was dried over sodium sulfate, the solvent was distilled off under reduced pressure, and the resulting solid was purified by column chromatography using silica gel to obtain the formula (7).
[0065]
Embedded image
[0066]
[Example 1]
50 parts by mass of the maleimide derivative (5) obtained in Synthesis Example 1 and 50 parts by mass of laurylmaleimide (manufactured by Daihachi Chemical) are dissolved in N, N-dimethylformamide to obtain a 5% solid content solution. It filtered with a 45 micrometer filter, and was set as the material solution for photo-alignment films. The obtained material solution for photo-alignment film was uniformly applied to a glass substrate with an ITO electrode by a spin coater, heated at 190 ° C. for 1 hour, and dried by solvent and cured by thermal polymerization of maleimide groups. Next, an ultrahigh pressure mercury lamp was used on the surface of the obtained coating film, wavelength 313 nm, energy density 20 mW / cm. 2 Was irradiated for 50 seconds. Subsequently, wavelength 313 nm, energy density 40 mW / cm 2 The non-polarized ultraviolet light was irradiated in a direction perpendicular to the polarization direction of the linearly polarized light previously irradiated and at an angle of 45 ° from the substrate surface for 120 seconds to produce a photo-alignment film.
[0067]
A thermosetting adhesive containing styrene beads having a diameter of 5 μm was applied around the substrate with a photo-alignment film obtained by the above method, leaving a liquid crystal injection port, and another substrate with a photo-alignment film was aligned on the alignment surface. Were opposed to each other, and the linearly polarized light previously irradiated was superposed and pressure-bonded so as to coincide with each other, and the adhesive was cured at 150 ° C. for 90 minutes. Next, after filling nematic liquid crystal composition ELS-001 (manufactured by Dainippon Ink & Chemicals, Inc.) from the liquid crystal injection port by vacuum injection in an isotropic phase state, the liquid crystal is filled with an epoxy adhesive. The inlet was sealed. The liquid crystal element thus obtained was observed with a polarizing microscope, and the alignment of the liquid crystal was confirmed. At this time, disclination due to orientation defects was not recognized.
Next, as a result of measuring the pretilt angle of the liquid crystal of this liquid crystal element by the rotating crystal method, the pretilt angle was 3.2 °. In addition, no change was observed in the pretilt angle even when the liquid crystal element was allowed to stand at room temperature under natural light for 3 months.
[0068]
[Example 2]
50 parts by mass of maleimide derivative (6) obtained in Synthesis Example 2 and 50 parts by mass of laurylmaleimide were dissolved in N, N-dimethylformamide to give a 5% solid content solution, which was filtered through a 0.45 μm filter. Thus, a material solution for a photo-alignment film was obtained. This was coated on a glass substrate in the same manner as in Example 1, dried by heating and thermally polymerized, and further irradiated with ultraviolet light. Further, a liquid crystal cell was manufactured by injecting liquid crystal cells and injecting liquid crystal in the same manner as in Example 1. The liquid crystal display device thus obtained was observed with a polarizing microscope, and the alignment of the liquid crystal was confirmed. At this time, disclination due to orientation defects was not recognized.
Next, as a result of measuring the pretilt angle of the liquid crystal of this liquid crystal element by a rotating crystal method, the pretilt angle was 3.5 °. Further, even when the liquid crystal element was left at room temperature under natural light for 3 months, no change was observed in the pretilt angle.
[0069]
[Example 3]
50 parts by mass of the maleimide derivative (6) obtained in Synthesis Example 2 and 50 parts by mass of the maleimide derivative (7) obtained in Synthesis Example 3 were dissolved in N, N-dimethylformamide to obtain a 5% solid content solution. This was filtered through a 0.45 μm filter to obtain a photoalignment film material solution. This was coated on a glass substrate in the same manner as in Example 1, dried by heating and thermally polymerized, and further irradiated with ultraviolet light. Further, a liquid crystal cell was manufactured by injecting liquid crystal cells and injecting liquid crystal in the same manner as in Example 1. The liquid crystal display device thus obtained was observed with a polarizing microscope, and the alignment of the liquid crystal was confirmed. At this time, disclination due to orientation defects was not recognized.
Next, as a result of measuring the pretilt angle of the liquid crystal of this liquid crystal element by the rotating crystal method, the pretilt angle was 4.0 °. In addition, no change was observed in the pretilt angle even when the liquid crystal element was allowed to stand at room temperature under natural light for 3 months.
[0070]
[Comparative example]
4,4-diphenylmethane bismaleimide represented by formula (8) (manufactured by Kay Kasei Co., Ltd.),
[0071]
Embedded image
Was dissolved in N, N-dimethylformamide to obtain a 5% solid content solution, which was filtered through a 0.45 μm filter to obtain a photoalignment film material solution. This was coated on a glass substrate in the same manner as in Example 1, dried by heating and thermally polymerized, and further irradiated with ultraviolet light. Further, a liquid crystal cell was manufactured by injecting liquid crystal cells and injecting liquid crystal in the same manner as in Example 1. When the liquid crystal element thus obtained was observed with a polarizing microscope, the alignment of the liquid crystal was confirmed.
Next, the pretilt angle of the liquid crystal of this liquid crystal element was measured by the rotating crystal method in the same manner as in Example 1. Almost no pretilt angle was observed.
[0073]
【The invention's effect】
By using the photo-alignment film material using the photo-alignment film material of the present invention, the productivity is excellent, the liquid crystal orientation is good, and a sufficient pre-tilt angle of liquid crystal molecules is obtained. However, it is possible to obtain a photo-alignment film for a liquid crystal display element having sufficient stability over time and heat.
Claims (6)
で表わされる化合物である請求項１に記載の光配向膜用材料。The monomer (a) having a photo-alignment group is represented by the general formula (1)
The material for photo-alignment films according to claim 1, which is a compound represented by the formula:
で表わされる化合物である請求項１に記載の光配向膜用材料。The monomer (b) having an alkyl group having 4 to 30 carbon atoms in one molecule is represented by the general formula (2) or (3).
The material for photo-alignment films according to claim 1, which is a compound represented by the formula:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001294300A JP4604438B2 (en) | 2001-09-26 | 2001-09-26 | Photo-alignment film material, photo-alignment film and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2001294300A JP4604438B2 (en) | 2001-09-26 | 2001-09-26 | Photo-alignment film material, photo-alignment film and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2003098527A JP2003098527A (en) | 2003-04-03 |
| JP4604438B2 true JP4604438B2 (en) | 2011-01-05 |
Family
ID=19115934
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2001294300A Expired - Fee Related JP4604438B2 (en) | 2001-09-26 | 2001-09-26 | Photo-alignment film material, photo-alignment film and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP4604438B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4826897B2 (en) * | 2005-03-31 | 2011-11-30 | Ｄｉｃ株式会社 | Method for manufacturing liquid crystal alignment film, and method for reducing tilt angle of liquid crystal alignment film |
| EP2131233B1 (en) * | 2007-03-26 | 2017-03-29 | Sharp Kabushiki Kaisha | Liquid crystal display device and polymer for aligning film material |
| KR101527402B1 (en) * | 2007-12-21 | 2015-06-09 | 롤릭 리미티드 | Photoalignment composition |
| TWI460209B (en) * | 2008-05-09 | 2014-11-11 | Chi Mei Corp | Liquid crystal aligning agent and method for producing liquid crystal alignment film |
| US10100201B2 (en) | 2014-02-28 | 2018-10-16 | Nissan Chemical Industries, Ltd. | Cured film formation composition, orientation material and retardation material |
Family Cites Families (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH08328005A (en) * | 1995-05-26 | 1996-12-13 | Hitachi Chem Co Ltd | Liquid crystal oriented film, treatment of liquid crystal oriented film, liquid crystal holding substrate, liquid crystal display element, production of liquid crystal display element and material for liquid crystal oriented film |
| KR100261119B1 (en) * | 1997-04-18 | 2000-08-01 | 김순택 | Optical alignment polymer |
| JPH11326912A (en) * | 1998-05-11 | 1999-11-26 | Hitachi Ltd | Liquid crystal display |
| KR100279043B1 (en) * | 1998-07-15 | 2001-01-15 | 윤종용 | Polymaleimide and Polyimide Photoalignment Material for Liquid Crystal Display |
| WO2000010974A2 (en) * | 1998-08-20 | 2000-03-02 | Dsm N.V. | Process for the preparation of a maleimide compound, maleimide compound, radiation-curable compositions comprising said compound and coated products |
| JP4228459B2 (en) * | 1999-03-16 | 2009-02-25 | チッソ株式会社 | Liquid crystal alignment film and liquid crystal display device using the alignment film |
| JP3508918B2 (en) * | 1999-08-12 | 2004-03-22 | 日本電気株式会社 | Method for manufacturing liquid crystal alignment film and liquid crystal display device |
| JP2001122981A (en) * | 1999-10-25 | 2001-05-08 | Nec Corp | Organic thin membrane, its production and photocuring composition |
| JP4803412B2 (en) * | 2001-03-14 | 2011-10-26 | Ｄｉｃ株式会社 | Photoalignment material containing maleimide derivative and method for producing photoalignment film |
| KR100465445B1 (en) * | 2001-07-31 | 2005-01-13 | 삼성전자주식회사 | Photo-induced Alignment Material for Liquid Crystal Alignment Film |
-
2001
- 2001-09-26 JP JP2001294300A patent/JP4604438B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JP2003098527A (en) | 2003-04-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4900632B2 (en) | Photo-alignment film material, photo-alignment film and method for producing the same | |
| JP4803412B2 (en) | Photoalignment material containing maleimide derivative and method for producing photoalignment film | |
| KR100803615B1 (en) | Photo-alignment film material, photo-alignment film and manufacturing method thereof | |
| CN102741740B (en) | Polymer for use in a liquid-crystal alignment layer | |
| JP5186734B2 (en) | Azo compound, composition for photo-alignment film, photo-alignment film and liquid crystal display element | |
| CN103732638B (en) | Copolymer and liquid crystal alignment layer comprising cured product of the copolymer | |
| JP4006608B2 (en) | Liquid crystalline (meth) acrylate compound, composition containing the compound, and optical anisotropic body using the same | |
| TWI810273B (en) | Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal element, polymer and compound | |
| JP4957976B2 (en) | Composition for vertical alignment layer | |
| CN103619803B (en) | Cinnamic acid derivative, its polymer, and liquid crystal alignment layer composed of its cured product | |
| JP2003270638A (en) | Composition for photo-alignment film and method for producing photo-alignment film using the same | |
| JP4522662B2 (en) | Composition for liquid crystal alignment film, liquid crystal alignment film, method for producing liquid crystal alignment film, and maleimide compound | |
| JP6644676B2 (en) | Cyanostilbene | |
| JP4604438B2 (en) | Photo-alignment film material, photo-alignment film and method for producing the same | |
| CN108603036B (en) | Liquid crystal aligning agent, liquid crystal alignment film, and liquid crystal display element | |
| CN102030653A (en) | Polymerizable compound | |
| CN101792391A (en) | Polymerizable biphenyl compound | |
| TWI854033B (en) | Liquid crystal alignment agent, liquid crystal alignment film, liquid crystal element, polymer and compound | |
| JP4756296B2 (en) | Maleimide derivative and method for producing photoalignment film using the same | |
| JP2004035722A (en) | Composition for photo-alignment film and method for producing photo-alignment film | |
| TWI910358B (en) | Liquid crystal alignment agents, liquid crystal alignment films, liquid crystal elements, polymers, and methods for manufacturing the same. | |
| TW553932B (en) | Material for light-oriented film, light-oriented film and process for producing the same | |
| JP2003064032A (en) | Polymerizable compound, liquid crystalline composition and polymer of the same | |
| JP2007100098A (en) | Polymerizable liquid crystal composition and optical anisotropic body using the same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| RD01 | Notification of change of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7421 Effective date: 20050822 |
|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20080908 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20100831 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20100907 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20100920 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 4604438 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131015 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20131015 Year of fee payment: 3 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |