JP4201183B2 - Alignment film and manufacturing method thereof - Google Patents

Description

【００７３】
（式中、ｎは１から１０の整数を表す）等のジアミノシロキサン等が挙げられる。
【００７４】
また、これらのジアミンの１種又は２種以上を混合して使用することもできる。本態様に用いられるポリイミドを得るために使用される直鎖状アルキル基を含有するジアミン成分の具体例を挙げると、下記化学式（２）のようなジアミノベンゼン誘導体、化学式（３）のようなジアミノビフェニル誘導体、化学式（４）のようなジアミノターフェニル誘導体、化学式（５）のようなジアミノジフェニルエーテル誘導体、化学式（６）のようなジフェニルメタン誘導体、化学式（７）のようなビス（アミノフェノキシ）フェニル誘導体などが挙げられ、Ｒは炭素数１２以上の直鎖状アルキル基、アルキロキシ基、アルキロキシメチレン基などである。
【００７５】
【化２】

【００７６】
また、これらのアルキルジアミンの１種又は２種以上を混合して使用することもできる。本態様に用いられるポリイミドを得るために使用される直鎖状アルキル基を含有するモノアミンの具体例を挙げれば、下記化学式（８）のような脂肪族アミン、化学式（９）の様な脂環式ジアミン、化学式（１０）のような芳香族アミンが挙げられ、Ｒは炭素数１２以上の直鎖状アルキル基、アルキロキシ基、アルキロキシメチレン基などである。
【００７７】
また、これらのアルキルジアミンの１種又は２種以上を混合して使用することもできる。
【００７８】
【化３】

【００７９】
本態様に用いられるポリイミドを得るために使用される直鎖状アルキル基を含有するジカルボン酸成分の具体例を挙げれば、下記化学式（１１）のような脂肪族ジカルボン酸及びその酸無水物及びその酸ハライド、化学式（１２）のような脂環式ジカルボン酸及びその酸無水物及びその酸ハライド、化学式（１３）のような芳香族ジカルボン酸及びその酸無水物及びその酸ハライドが挙げられ、Ｒは炭素数１２以上の直鎖状アルキル基、アルキロキシ基、アルキロキシメチレン基などである。
【００８０】
また、これらのジカルボン酸成分の１種又は２種以上を混合して使用することもできる。
【００８１】
【化４】

【００８２】
テトラカルボン酸成分とジアミン成分とを反応、重合させポリイミド樹脂前駆体とした後、これを脱水閉環イミド化するが、この際用いるテトラカルボン酸成分としてはテトラカルボン酸二無水物を用いるのが一般的である。テトラカルボン酸二無水物の総モル数とジアミン成分の総モル数との比は０．８から１．２であることが好ましい。通常の重縮合反応同様、このモル比が１に近いほど生成する重合体の重合度は大きくなる。
【００８３】
重合度が小さすぎると配向膜として使用する際にポリイミド膜の強度が不十分で、液晶の配向が不安定となる。また、重合度が大きすぎるとポリイミド樹脂膜形成時の作業性が悪くなる場合がある。従って本反応における生成物の重合度は、ポリイミド前駆体溶液の還元粘度換算で０．０５〜３．０ｄｌ／ｇ（温度３０℃のＮ−メチルピロリドン中、濃度０．５ｇ／ｄｌ）とするのが好ましい。
【００８４】
また、本態様に用いられる直鎖状アルキル基を含有するポリイミドを得る方法の一つとして、直鎖状アルキル基を含有するジイミド化合物を混合する方法がある。このジイミド化合物を得るには、直鎖状アルキル基を含有するジカルボン酸成分とジアミン成分をモル比２対１で反応させジイミド化合物前駆体とした後、これを脱水閉環イミド化する方法及び／又は直鎖状アルキル基を含有するモノアミン成分とテトラカルボン酸二無水物をモル比２対１で反応させジイミド化合物駆体とした後、これを脱水閉環イミド化する方法がある。
【００８５】
さらに、本態様の直鎖状アルキル基を含有するポリイミドを得る方法の一つとして、ポリイミドの分子鎖末端に直鎖状アルキル基を導入する方法がある。この場合には、テトラカルボン酸成分とジアミン成分とを反応、重合させる際に、直鎖状アルキル基を含有するジカルボン酸成分を反応させる方法、及び／又は、テトラカルボン酸成分とジアミン成分とを反応、重合させる際に、直鎖状アルキル基を含有するモノアミン成分を反応させる方法がある。直鎖状アルキル基を含有するジカルボン酸成分を反応させる際には、テトラカルボン酸成分及びジカルボン酸成分のカルボン酸残基の総モル数ａとジアミン成分のアミン残基の総モル数ｂの比ａ／ｂは２以下であり、又、直鎖状アルキル基を含有するモノアミン成分を反応させる際には、テトラカルボン酸成分のカルボン酸残基の総モル数ａ’とジアミン成分及びモノアミン成分のアミン残基の総モル数ｂ’との比ａ’／ｂ’は２以上であることが好ましい。
【００８６】
モル比ａ／ｂが２より大きい場合、又はモル比ａ’／ｂ’が２より小さい場合には、ポリイミド前駆体とした後、これを脱水閉環イミド化した際に、ジカルボン酸成分又はモノアミン成分の反応が不十分となり、液晶配向処理剤としたときに液晶セルの特性に悪影響を及ぼす可能性がある。これらのテトラカルボン酸成分、ジアミン成分、ジカルボン酸成分、モノアミン成分は、N-メチルピロリドン、N,N-ジメチルアセトアミド、N,N-ジメチルホルムアミド等の有機極性溶媒中で反応させるのが一般的である。
【００８７】
これらを反応させポリイミド前駆体とする際の反応温度は、−２０から１５０℃、好ましくは−５から１００℃の任意の温度を選択することができる。
【００８８】
さらに、このポリイミド前駆体を１００〜４００℃で加熱脱水するか、または通常用いられているトリエチルアミン／無水酢酸などのイミド化触媒を用いて化学的イミド化を行うことにより、ポリイミドとすることができる。
【００８９】
（ポリアミド系）
一方、本態様に用いられるポリアミドとしては、例えば特開平９−２３０３５４号公報に示されるもの等を用いることができる。
【００９０】
具体的には、繰り返し単位が下記一般式（１４）
【００９１】
【化５】

【００９２】
（式（１４）中、Ａはジカルボン酸を構成する２価の有機基、Ｘは、下記一般式（１５）
【００９３】
【化６】

【００９４】
または下記一般式（１６）
【００９５】
【化７】

【００９６】
で表される置換基であり、上記式（１５）または（１６）中、Ｙ¹は酸素原子、または−ＣＨ₂Ｏ−、−Ｃ（＝Ｏ）Ｏ−もしくは−ＯＣ（＝Ｏ）−で表される２価の有機基、Ｒ¹は炭素数８〜２２のアルキル基または含フッ素アルキル基、Ｙ²は−（ＣＨ₂）_n −、−Ｏ（ＣＨ₂）_n −、−ＣＨ₂Ｏ（ＣＨ₂）_n−、−Ｃ（＝Ｏ）Ｏ（ＣＨ₂）_n −もしくは−ＯＣ（＝Ｏ）（ＣＨ₂）_n −（ｎは２〜６の整数）で表される２価の有機基、Ｒ²〜Ｒ⁶は同一または異なっても良く炭素数１〜６のアルキル基、ｍは１以上の整数である。）で表わされ、重量平均分子量が１０００以上であるポリアミド等を挙げることができる。
【００９７】
上記一般式（１５）中Ｒ¹で表されるアルキル基としては、オクチル基、ノニル基、ウンデシル基、デシル基、ドデシル基、トリデシル基、テトラデシル基、ペンタデシル基、ヘキサデシル基、ヘプタデシル基、オクタデシル基、エイコサニル基及びドコサニル基等の直鎖状アルキル基、１−エチルヘキシル基、２−エチルヘキシル基、３−エチルヘキシル基、１−メチルヘプチル基、２−メチルヘプチル基、３−メチルヘプチル基、１−メチルオクチル基、２−メチルオクチル基、２−エチルオクチル基、１−メチルデシル基、２−メチルデシル基、３−メチルデシル基、１−メチルドデシル基、１−メチルテトラデシル基、１−メチルヘキサデシル基、１−メチルオクタデシル基、１−メチルエイコサニル基及び２−エチルエイコサニル基等の分岐状アルキル基を例示することができる。
【００９８】
また、同じくＲ¹で表される含フッ素アルキル基としては、上記アルキル基の水素原子が１個以上フッ素原子で置換されたものが挙げられるが、特に好ましいものとしては、ペルフルオロオクチル基、ペルフルオロノニル基、ペルフルオロウンデシル基、ペルフルオロデシル基、ペルフルオロドデシル基、ペルフルオロトリデシル基、ペルフルオロテトラデシル基、ペルフルオロペンタデシル基、ペルフルオロヘキサデシル基、ペルフルオロヘプタデシル基、ペルフルオロオクタデシル基、ペルフルオロエイコサニル基、ペルフルオロドコサニル基、１Ｈ，１Ｈ−ペンタデカフルオロオクチル基、１Ｈ,１Ｈ−ヘプタデカフルオロノニル基、１Ｈ,１Ｈ−ノナデカフルオロデシル基、１Ｈ,１Ｈ−ヘンイコサフルオロウンデシル基、１Ｈ,１Ｈ−トリコサフルオロドデシル基、１Ｈ,１Ｈ−ペンタコサフルオロトリデシル基、１Ｈ,１Ｈ,２Ｈ,２Ｈ−トリデカフルオロオクチル基、１Ｈ,１Ｈ,２Ｈ,２Ｈ−ヘプタデカフルオロデシル基、１Ｈ,１Ｈ,２Ｈ,２Ｈ−ヘンイコサフルオロドデシル基及び１Ｈ,１Ｈ,２Ｈ,２Ｈ−ペンタコサフルオロテトラデシル基等を例示することができる。なお、上記のアルキル基および含フッ素アルキル基は繰り返し単位ごとに任意に異なっても良い。
【００９９】
また、上記一般式（１６）中Ｒ²〜Ｒ⁶で表わされるアルキル基としては、メチル基、エチル基、プロピル基、イソプロピル基、ブチル基、イソブチル基、ｔ−ブチル基、ペンチル基、ヘキシル基等の直鎖状または分岐状の低級アルキル基が挙げられる。しかしながら、合成の容易さおよび本発明の液晶配向膜としての特性を生かすためには、上記の置換基のうちメチル基が最も好ましい。
【０１００】
（ポリシロキサン系）
本態様のバインダに用いられる材料としては、後述するように光触媒により表面処理を行う点から考慮すると、露光により光触媒含有配向膜中の光触媒により濡れ性が変化する材料で、かつ光触媒の作用により劣化、分解しにくい主鎖を有するものが好ましい。この点から、好ましい材料としてはオルガノポリシロキサンを挙げることができる。本態様においては、中でも上記オルガノポリシロキサンが、フルオロアルキル基を含有するオルガノポリシロキサンであることが好ましい。
【０１０１】
このようなオルガノポリシロキサンとしては、例えば、ゾルゲル反応等によりクロロまたはアルコキシシラン等を加水分解、重縮合して大きな強度を発揮するオルガノポリシロキサンを挙げることができる。
【０１０２】
上記の場合、一般式：
Ｙ_ｎＳｉＸ_{（４−ｎ）}
（ここで、Ｙはアルキル基、フルオロアルキル基、ビニル基、アミノ基、フェニル基またはエポキシ基を示し、Ｘはアルコキシル基、アセチル基またはハロゲンを示す。ｎは０〜３までの整数である。）
で示される珪素化合物の１種または２種以上の加水分解縮合物もしくは共加水分解縮合物であるオルガノポリシロキサンであることが好ましい。なお、ここでＹで示される基の炭素数は１〜２０の範囲内であることが好ましく、また、Ｘで示されるアルコキシ基は、メトキシ基、エトキシ基、プロポキシ基、ブトキシ基であることが好ましい。
【０１０３】
また、特に側鎖として下記に示すようなフルオロアルキル基を含有するオルガノポリシロキサンを好ましく用いることができ、具体的には、下記のフルオロアルキルシランの１種または２種以上の加水分解縮合物、共加水分解縮合物が挙げられる。
【０１０４】
ＣＦ_３（ＣＦ_２）_３ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_５ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_７ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_９ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
（ＣＦ_３）_２ＣＦ（ＣＦ_２）_４ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
（ＣＦ_３）_２ＣＦ（ＣＦ_２）_６ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
（ＣＦ_３）_２ＣＦ（ＣＦ_２）_８ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_３（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_５（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_７（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４Ｓｉ（ＯＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_３ＣＨ_２ＣＨ_２ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_５ＣＨ_２ＣＨ_２ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_７ＣＨ_２ＣＨ_２ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_９ＣＨ_２ＣＨ_２ＳｉＣＨ_３（ＯＣＨ_３）_２；
（ＣＦ_３）_２ＣＦ（ＣＦ_２）_４ＣＨ_２ＣＨ_２ＳｉＣＨ_３（ＯＣＨ_３）_２；
（ＣＦ_３）_２ＣＦ（ＣＦ_２）_６ＣＨ_２ＣＨ_２Ｓｉ ＣＨ_３（ＯＣＨ_３）_２；
（ＣＦ_３）_２ＣＦ（ＣＦ_２）_８ＣＨ_２ＣＨ_２Ｓｉ ＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_３（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_５（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_７（Ｃ_６Ｈ_４）Ｃ_２Ｈ_４ＳｉＣＨ_３（ＯＣＨ_３）_２；
ＣＦ_３（ＣＦ_２）_３ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_２ＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_５ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_２ＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_７ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_２ＣＨ_３）_３；
ＣＦ_３（ＣＦ_２）_９ＣＨ_２ＣＨ_２Ｓｉ（ＯＣＨ_２ＣＨ_３）_３；および
ＣＦ_３（ＣＦ_２）_７ＳＯ_２Ｎ（Ｃ_２Ｈ_５）Ｃ_２Ｈ_４ＣＨ_２Ｓｉ（ＯＣＨ_３）_３。
【０１０５】
上記のようなフルオロアルキル基を側鎖として含有するポリシロキサンを配向層として用いることにより、濡れ性変化層の未露光部の撥水性が大きく向上し、かつ側鎖が形成されることから、大幅に配向特性を向上させることができる。
【０１０６】
（ａ−２）第２の態様
第２の態様に用いられるバインダ、すなわち光触媒の作用により光触媒含有配向膜上の濡れ性を変化させる機能を特に必要としないバインダとしては、バインダの主骨格が光触媒の光励起により分解されないような高い結合エネルギーを有するものであれば特に限定されるものではない。例えば、無定形シリカ前駆体を用いることができる。この無定形シリカ前駆体は、一般式ＳｉＸ_４で表され、Ｘはハロゲン、メトキシ基、エトキシ基、またはアセチル基等であるケイ素化合物、それらの加水分解物であるシラノール、または平均分子量３０００以下のポリシロキサンが好ましい。具体的には、テトラエトキシシラン、テトライソプロポキシシラン、テトラ−ｎ−プロポキシシラン、テトラブトキシシラン、テトラメトキシシラン等が挙げられる。また、この場合には、無定形シリカの前駆体と光触媒の粒子とを非水性溶媒中に均一に分散させ、基板上に空気中の水分により加水分解させてシラノールを形成させた後、常温で脱水縮重合することにより光触媒含有配向膜を形成できる。シラノールの脱水縮重合を１００℃以上で行えば、シラノールの重合度が増し、膜表面の強度を向上できる。また、これらの結着剤は、単独あるいは２種以上を混合して用いることができる。
【０１０７】
このようなバインダを用いた場合は、添加剤として後述するエネルギー照射による光触媒の作用により分解され、これにより光触媒含有配向膜上の濡れ性を変化させることができる分解物質を光触媒含有配向膜中に含有させることが必須となる。
【０１０８】
（分解物質）
上記第２の態様および第３の態様においては、エネルギー照射による光触媒の作用により分解され、これにより光触媒含有配向膜上の濡れ性を変化させることができる分解物質を光触媒含有配向膜に含有させる必要がある。すなわち、バインダ自体に光触媒含有配向膜上の濡れ性を変化させる機能がない場合、およびそのような機能が不足している場合に、上述したような分解物質を添加して、上記光触媒含有配向膜上の濡れ性の変化を起こさせる、もしくはそのような変化を補助させるようにするのである。
【０１０９】
このような分解物質としては、光触媒の作用により分解し、かつ分解されることにより光触媒含有配向膜表面の濡れ性を変化させる機能を有する界面活性剤を挙げることができる。具体的には、日光ケミカルズ（株）製ＮＩＫＫＯＬ ＢＬ、ＢＣ、ＢＯ、ＢＢの各シリーズ等の炭化水素系、デュポン社製ＺＯＮＹＬ ＦＳＮ、ＦＳＯ、旭硝子（株）製サーフロンＳ−１４１、１４５、大日本インキ化学工業（株）製メガファックＦ−１４１、１４４、ネオス（株）製フタージェントＦ−２００、Ｆ２５１、ダイキン工業（株）製ユニダインＤＳ−４０１、４０２、スリーエム（株）製フロラードＦＣ−１７０、１７６等のフッ素系あるいはシリコーン系の非イオン界面活性剤を挙げることかでき、また、カチオン系界面活性剤、アニオン系界面活性剤、両性界面活性剤を用いることもできる。
【０１１０】
また、界面活性剤の他にも、ポリビニルアルコール、不飽和ポリエステル、アクリル樹脂、ポリエチレン、ジアリルフタレート、エチレンプロピレンジエンモノマー、エポキシ樹脂、フェノール樹脂、ポリウレタン、メラミン樹脂、ポリカーボネート、ポリ塩化ビニル、ポリアミド、ポリイミド、スチレンブタジエンゴム、クロロプレンゴム、ポリプロピレン、ポリブチレン、ポリスチレン、ポリ酢酸ビニル、ポリエステル、ポリブタジエン、ポリベンズイミダゾール、ポリアクリルニトリル、エピクロルヒドリン、ポリサルファイド、ポリイソプレン等のオリゴマー、ポリマー等を含有させることができる。
【０１１１】
ｂ．光触媒
次に、本実施態様で使用する光触媒について説明する。本実施態様で使用する光触媒としては、光半導体として知られる例えば二酸化チタン（ＴｉＯ_２）、酸化亜鉛（ＺｎＯ）、酸化スズ（ＳｎＯ_２）、チタン酸ストロンチウム（ＳｒＴｉＯ_３）、酸化タングステン（ＷＯ_３）、酸化ビスマス（Ｂｉ_２Ｏ_３）、および酸化鉄（Ｆｅ_２Ｏ_３）を挙げることができ、これらから選択して１種または２種以上を混合して用いることができる。
【０１１２】
本実施態様においては、特に二酸化チタンが、バンドギャップエネルギーが高く、化学的に安定で毒性もなく、入手も容易であることから好適に使用される。二酸化チタンには、アナターゼ型とルチル型があり本実施態様ではいずれも使用することができるが、アナターゼ型の二酸化チタンが好ましい。アナターゼ型二酸化チタンは励起波長が３８０ｎｍ以下にある。
【０１１３】
このようなアナターゼ型二酸化チタンとしては、例えば、塩酸解膠型のアナターゼ型チタニアゾル（石原産業（株）製ＳＴＳ−０２（平均粒径７ｎｍ）、石原産業（株）製ＳＴ−Ｋ０１）、硝酸解膠型のアナターゼ型チタニアゾル（日産化学（株）製ＴＡ−１５（平均粒径１２ｎｍ））等を挙げることができる。
【０１１４】
光触媒の粒径は小さいほど光触媒反応が効果的に起こるので好ましく、平均粒径か５０ｎｍ以下が好ましく、２０ｎｍ以下の光触媒を使用するのが特に好ましい。
【０１１５】
本実施態様に用いられる光触媒含有配向膜中の光触媒の含有量は、５〜６０重量％、好ましくは２０〜４０重量％の範囲で設定することができる。
【０１１６】
光触媒含有配向膜における、二酸化チタンに代表される光触媒の作用機構は、必ずしも明確なものではないが、光の照射によって生成したキャリアが、近傍の化合物との直接反応、あるいは、酸素、水の存在下で生じた活性酸素種によって、有機物の化学構造に変化を及ぼすものと考えられている。本実施態様においては、このキャリアが光触媒含有配向膜中の化合物に作用を及ぼすものであると思われる。
【０１１７】
（３）その他
本実施態様における光触媒含有配向膜の膜厚としては、光触媒による濡れ性の変化速度の関係により、０．０５〜１０μｍの範囲内が好ましい。
【０１１８】
また、本実施態様の光触媒配向膜は、通常液晶表示装置において配向膜が配置される位置、すなわち液晶層を挟むように配置される。また、本実施態様の配向膜は、通常液晶層のカラーフィルタ側もしくはアレイ基板側のいずかの表面に配置されるが、必要であれば両方に配置するようにしてもよい。
【０１１９】
２．第二実施態様
次に、本発明の配向膜の第二実施態様について説明する。本発明の配向膜の第二実施態様は、光触媒配向膜が、光触媒を含有する光触媒処理層と、上記光触媒処理層上に形成された濡れ性変化配向膜とからなることを特徴とするものである。このような本実施態様の配向膜について、各構成について説明する。
【０１２０】
（１）撥水性領域および親水性領域
本実施態様における撥水性領域および親水性領域に関しては、上述した「１．第一実施態様」に記載したものと同様であるので、ここでの説明は省略する。
【０１２１】
（２）濡れ性変化配向膜
本実施態様における濡れ性変化配向膜は、光触媒の作用により濡れ性が変化するものであれば、特にその材料は限定されるものではない。しかしながら、上記第一実施態様の光触媒含有配向膜中のバインダと同様の材料で形成することが好ましい。なお、このように上記第一実施態様の光触媒含有配向膜中のバインダと同様の材料で形成した場合の濡れ性変化配向膜の材料に関しては、上述した「１．第一実施態様」に記載したものと同様であるので、ここでの説明は省略する。
【０１２２】
本実施態様の濡れ性変化配向膜の膜厚としては、光触媒による濡れ性の変化速度の関係により、好ましくは０．００１〜１μｍの範囲内、より好ましくは０．０１〜０．１μｍの範囲内である。
【０１２３】
（３）光触媒処理層
次に、光触媒処理層について説明する。本実施態様においては、光触媒処理層は、光触媒処理層中の光触媒が、上記光触媒処理層上に形成された濡れ性配向膜の濡れ性を変化させるように形成されたものであれば、特に限定されるものではなく、光触媒単体で製膜されたものであってもよいし、光触媒とバインダとから構成されているものであってもよい。また、その表面の濡れ性は特に親水性であっても撥水性であってもよい。
【０１２４】
本実施態様で用いられる光触媒に関しては、上述した「１．第一実施態様」に記載したものと同様であるので、ここでの説明は省略する。
【０１２５】
また、光触媒処理層がバインダを有する場合は、上記第一実施態様で説明した光触媒含有配向膜と同様であるので、ここでの説明は省略する。
【０１２６】
光触媒処理層の厚みは、０．０５〜１０μｍの範囲内が好ましい。
【０１２７】
（４）その他
本実施態様の光触媒配向膜は、通常液晶表示装置において配向膜が配置される位置、すなわち液晶層を挟むように配置される。また、本発明の配向膜は、通常液晶層のカラーフィルタ側もしくはアレイ基板側のいずかの表面に配置されるが、必要であれば両方に配置するようにしてもよい。
【０１２８】
Ｂ．配向膜の製造方法
次に、本発明に含まれる配向膜の製造方法について説明する。本発明の配向膜の製造方法は、２つの実施態様がある。以下、それぞれの配向膜の製造方法について説明する。
【０１２９】
１．第三実施態様
まず、本発明の配向膜の製造方法の第三実施態様について説明する。本発明の第三実施態様は、基板上に形成され、光触媒とバインダとを有し、光触媒の作用により表面の濡れ性が変化する光触媒含有配向膜からなる光触媒配向膜を形成する光触媒配向膜形成工程と、上記光触媒含有配向膜にパターン状にエネルギーを照射することにより、上記光触媒含有配向膜上に撥水性領域とこの撥水性領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを形成する濡れ性パターン形成工程とを有することを特徴とするものである。
【０１３０】
本発明においては、このように配向膜上に撥水性領域と撥水性領域とからなる濡れ性のパターンを形成することのみで、画素内における液晶分子の配向を行うことが可能である。したがって、液晶表示装置がＭＶＡモードの液晶表示装置の場合、例えば突起部等の構造物を形成する等の方法よりも容易に画素内における液晶分子の配向方向を分割することを可能とすることができる。
【０１３１】
（１）光触媒配向膜形成工程
本実施態様の光触媒配向膜形成工程においては、まず基板上に、バインダと光触媒とを有し、光触媒の作用により表面の濡れ性が変化する光触媒含有配向膜からなる光触媒配向膜を形成する光触媒配向膜形成工程が行われる。
【０１３２】
ａ．基板
本実施態様においては、図１２に示すように、光触媒配向膜用基板３は、少なくとも基板１と、この基板１上に形成された光触媒含有配向膜２とを有するものである。
【０１３３】
本実施態様に用いられる基板としては、透明な材料であれば、樹脂製フィルム等の可撓性を有するものであっても、ガラス等の可撓性を有さないものであってもよい。
【０１３４】
一般的には、このような基板上に透明電極層等の種々の機能層が形成され、その上に光触媒含有配向膜が形成される。
【０１３５】
ｂ．光触媒含有配向膜
本実施態様に用いられる光触媒含有配向膜は、バインダと光触媒とを有し、光触媒の作用により濡れ性が変化するものである。
【０１３６】
本実施態様の光触媒含有配向膜を構成するバインダ、光触媒に関しては、上述した「Ａ．配向膜」に記載したものと同様であるので、ここでの説明は省略する。
【０１３７】
バインダとしてポリシロキサンを用いた場合は、上記光触媒含有配向膜は、光触媒とバインダであるポリシロキサンとを必要に応じて他の添加剤とともに溶剤中に分散して塗布液を調製し、この塗布液を基板上に塗布することにより形成することができる。使用する溶剤としては、エタノール、イソプロパノール等のアルコール系の有機溶剤が好ましい。塗布はスピンコート、スプレーコート、ディッブコート、ロールコート、ビードコート等の公知の塗布方法により行うことができる。バインダとして紫外線硬化型の成分を含有している場合、紫外線を照射して硬化処理を行うことにより光触媒含有配向膜を形成することができる。
【０１３８】
（２）濡れ性パターン形成工程
本実施態様においては、上記光触媒含有配向膜にパターン状にエネルギーを照射することにより、上記光触媒含有配向膜上に撥水性領域とこの撥水性領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを形成する濡れ性パターン形成工程が行われる。
【０１３９】
本実施態様でいうエネルギー照射（露光）とは、光触媒による光触媒含有配向膜表面の濡れ性を変化させることが可能ないかなるエネルギー線の照射をも含む概念であり、可視光の照射に限定されるものではない。
【０１４０】
通常このような露光に用いる光の波長は、４００ｎｍ以下の範囲、好ましくは３８０ｎｍ以下の範囲から設定される。これは、上述したように光触媒含有配向膜に用いられる好ましい光触媒が二酸化チタンであり、この二酸化チタンにより光触媒作用を活性化させるエネルギーとして、上述した波長の光が好ましいからである。
【０１４１】
このような露光に用いることができる光源としては、水銀ランプ、メタルハライドランプ、キセノンランプ、エキシマランプ、その他種々の光源を挙げることができる。
【０１４２】
上述したような光源を用い、フォトマスクを介したパターンエネルギー照射により行う方法の他、エキシマ、ＹＡＧ等のレーザを用いてパターン状に描画照射する方法を用いることも可能である。
【０１４３】
また、露光に際してのエネルギーの照射量は、光触媒含有配向膜表面が光触媒含有配向膜中の光触媒の作用により光触媒含有配向膜表面の濡れ性の変化が行われるのに必要な照射量とする。
【０１４４】
この際、光触媒含有配向膜を加熱しながら露光することにより、感度を上昇させことが可能となり、効率的な濡れ性の変化を行うことができる点で好ましい。具体的には３０℃〜８０℃の範囲内で加熱することが好ましい。
【０１４５】
本実施態様における露光方向としては、基板側および光触媒含有配向膜側のいずれの方向からフォトマスクを介したパターンエネルギー照射もしくはレーザの描画照射を行ってもよいものである。
【０１４６】
（３）その他
本実施態様におけるその他の点、例えば撥水性領域および親水性領域の事項に関しては、上記「Ａ．配向膜」の欄で説明したものと同様であるので、ここでの説明は省略する。
【０１４７】
２．第四実施態様
次に、本発明の配向膜の製造方法の第四実施態様について説明する。本発明の第四実施態様は、基板上に形成され、光触媒を含有する光触媒処理層と、上記光触媒処理層上に形成され、光触媒により表面の濡れ性が変化する濡れ性変化配向膜とからなる光触媒配向膜を形成する光触媒配向膜形成工程と、上記濡れ性変化配向膜にパターン状にエネルギーを照射することにより、上記濡れ性変化配向膜上に撥水性領域とこの撥水性領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを形成する濡れ性パターン形成工程とを有することを特徴とするものである。
【０１４８】
本実施態様においては、このように配向膜上に撥水性領域と撥水性領域とからなる濡れ性のパターンを形成することのみで、画素内における液晶分子の配向分割を行うことが可能である。したがって、例えば突起部等の構造物を形成する等の方法よりも容易に画素内における液晶分子の配向方向を分割することを可能とすることができる。
【０１４９】
（１）光触媒配向膜形成工程
本実施態様の光触媒配向膜形成工程においては、まず基板上に形成され、光触媒を含有する光触媒処理層と、この光触媒処理層上に形成され、光触媒により表面の濡れ性が変化する濡れ性変化配向膜とからなる光触媒配向膜を形成する光触媒配向膜形成工程が行われる。
【０１５０】
ａ．基板
本実施態様においては、図１３に示すように、光触媒配向膜用基板３は、少なくとも基板１と、この基板１上に形成された光触媒処理層４と、この光触媒処理層上に形成された濡れ性変化配向膜５とを有するものである。
【０１５１】
本実施態様に用いられる基板としては、第三実施態様と同様に、透明な材料であれば、樹脂製フィルム等の可撓性を有するものであっても、ガラス等の可撓性を有さないものであってもよい。
【０１５２】
一般的には、このような基板上に透明電極層等の種々の機能層が形成され、その上に光触媒配向膜が形成される。
【０１５３】
ｂ．光触媒処理層
本実施態様に用いられる光触媒処理層は、光触媒処理層中の光触媒が、上記光触媒処理層上に形成された濡れ性変化配向膜の濡れ性を変化させるように形成されるものであれば、特に限定されるものではなく、光触媒とバインダとから構成されているものであってもよいし、光触媒単体で製膜されたものであってもよい。また、その表面の濡れ性は特に親水性であっても撥水性であってもよい。
【０１５４】
本実施態様においては、例えば図１３に示すように、基板１上に全面に光触媒処理層４が形成され、この光触媒処理層上に濡れ性変化配向膜５が形成されて光触媒配向膜基板３としたものであってもよいが、例えば図１４に示すように、基板１上に光触媒処理層４がパターン状に形成され、この光触媒処理層上に濡れ性変化配向膜５が形成されたものであってもよい。
【０１５５】
このように光触媒処理層をパターン状に形成することにより、後述する濡れ性パターン形成工程において説明するように、濡れ性変化配向膜にエネルギーを照射する際に、フォトマスク等を用いるパターン照射をする必要がなく、全面に照射することにより、濡れ性変化配向膜上に親水性領域と撥水性領域とからなる濡れ性パターンを形成することができる。
【０１５６】
この光触媒処理層のパターニング方法は、特に限定されるものではないが、例えばフォトリソグラフィ法等により行うことが可能である。
【０１５７】
また、実際に光触媒処理層上の濡れ性変化配向膜の部分のみの濡れ性が変化するものであるので、エネルギーの照射方向は上記光触媒処理層上の濡れ性変化配向膜の部分にエネルギーが照射されるものであれば、いかなる方向から照射されてもよく、さらには、照射されるエネルギーも特に平行光等の平行なものに限定されないという利点を有するものとなる。
【０１５８】
本実施様態で使用する光触媒に関しては、上述した「Ａ．配向膜」に記載したものと同様であるので、ここでの説明は省略する。
【０１５９】
また、光触媒処理層がバインダを有する場合は、上述した「１．第三実施態様」で説明した光触媒含有配向膜と同様であるので、ここでの説明は省略する。
【０１６０】
光触媒のみからなる光触媒処理層の形成方法としては、例えば、スパッタリング法、ＣＶＤ法、真空蒸着法等の真空製膜法を用いる方法を挙げることができる。真空製膜法により光触媒処理層を形成することにより、均一な膜でかつ光触媒のみを含有する光触媒処理層とすることができる。これにより、濡れ性変化配向膜上の濡れ性を均一に変化させることが可能であり、かつ光触媒のみからなることから、バインダを用いる場合と比較して効率的に濡れ性変化層上の濡れ性を変化させることが可能となる。
【０１６１】
また、光触媒のみからなる光触媒処理層の形成方法としては、例えば光触媒が二酸化チタンの場合は、基板上に無定形チタニアを形成し、次いで焼成により結晶性チタニアに相変化させる方法等が挙げられる。ここで用いられる無定形チタニアとしては、例えば四塩化チタン、硫酸チタン等のチタンの無機塩の加水分解、脱水縮合、テトラエトキシチタン、テトライソプロポキシチタン、テトラ−ｎ−プロポキシチタン、テトラブトキシチタン、テトラメトキシチタン等の有機チタン化合物を酸存在下において加水分解、脱水縮合によって得ることができる。次いで、４００℃〜５００℃における焼成によってアナターゼ型チタニアに変性し、６００℃〜７００℃の焼成によってルチル型チタニアに変性することができる。
【０１６２】
光触媒のみからなる光触媒処理層の場合は、濡れ性変化配向膜上の濡れ性の変化に対する効率が向上し、処理時間の短縮化等のコスト面で有利である。一方、光触媒とバインダとからなる光触媒処理層の場合は、光触媒処理層の形成が容易であるという利点を有する。
【０１６３】
ｃ．濡れ性変化配向膜
次に、濡れ性変化配向膜について説明する。本実施態様においては、濡れ性変化配向膜は、光触媒の作用により濡れ性が変化するものであれば、特にその材料は限定されるものではないが、上記第三実施態様の光触媒含有配向膜中のバインダと同様の材料で形成することが好ましい。このように上記第三実施態様の光触媒含有配向膜中のバインダと同様の材料で形成した場合の濡れ性変化配向膜の材料および形成方法に関しては、上述した「１．第三実施態様」に記載したものと同様であるので、ここでの説明は省略する。
【０１６４】
（２）濡れ性パターン形成工程
次に、本実施態様の濡れ性パターン形成工程について説明する。本実施態様においては、上記濡れ性変化配向膜にパターン状にエネルギーを照射することにより、上記濡れ性変化配向膜上に撥水性領域とこの撥水性領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを形成する濡れ性パターン形成工程が行われる。
【０１６５】
上記光触媒処理層が基板上に全面に形成されている場合は、基板側および濡れ性変化配向膜側のいずれの方向からフォトマスクを介したパターンエネルギー照射もしくはレーザの描画照射を行ってもよいものである。
【０１６６】
一方、上記光触媒層が基板上にパターン状に形成されている場合は、上述したように、上記光触媒処理層上の濡れ性変化配向膜の部分にエネルギーが照射されるものであれば、いかなる方向から照射されてもよい。さらに、照射されるエネルギーは、特に平行光等の平行なものに限定されないものである。
【０１６７】
本実施態様の濡れ性パターン形成工程における、エネルギーやエネルギーの照射方法等に関しては、上述した「１．第三実施態様」に記載したものと同様であるので、ここでの説明は省略する。
【０１６８】
（３）その他
本実施態様におけるその他の点、例えば撥水性領域および親水性領域の事項に関しては、上記「Ａ．配向膜」の欄で説明したものと同様であるので、ここでの説明は省略する。
【０１６９】
Ｃ．配向膜付基板
次に、本発明の配向膜付基板について説明する。本発明の配向膜付基板は、基板と、上記基板上に形成され、液晶層が接触する側に表面に、撥水性領域とこの撥水性領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを有しており、光触媒を含有し、かつ光触媒の作用により表面の濡れ性が変化する配向膜とを有することを特徴とする。このように、撥水性領域内に親水性領域をパターン状に形成された配向膜を有することにより、例えば垂直配向モードの液晶表示装置に用いた場合、撥水性領域では垂直に配向する液晶分子が、親水性領域では傾く性質を利用することにより、垂直に配向した液晶分子の画素内での配向分割を可能とすることができる。
【０１７０】
図１５は、このような本発明の配向膜付基板の一例を示すものであり、基板１上に透明電極層７を介して配向膜６が形成された状態を示すものである。
【０１７１】
本発明の配向膜付基板に用いられる配向膜は、上記「Ａ．配向膜」の欄で説明したものと同様であるので、ここでの説明は省略する。
【０１７２】
また、本発明で用いられる基板は、通常は透明基板であり、ガラス等の可撓性を有さないものであっても、透明樹脂等の可撓性を有するものであってもよい。
【０１７３】
本発明においては、例えば図１６に示すように、通常、上記配向膜の表面側に液晶層８が配置される。
【０１７４】
なお、本発明の配向膜を利用して、硬化性のコレステリック液晶（例えば、硬化性のネマティック液晶と硬化性のカイラル剤との混合物）を配向させ硬化させることで半透過反射膜を作成することもでき、また、硬化性のネマティック液晶、硬化性の短ピッチのコレステリック液晶、硬化性のディスコティック液晶を用いて、同様に、本発明の配向膜で配向させ硬化させることで、複屈折率を持つ位相差層となり、光学補償シートとして利用することができる。
【０１７５】
上記液晶層に用いられる液晶分子としては、負の誘電率異方性を有するネガ型液晶材料であって、常温において、ネマティック相を有するものであれば特に限定されるものではない。具体的には、メルク社のＭＬＣ−６６０８、ＭＬＣ−２０３７、ＭＬＣ−２０３８、ＭＬＣ−２０３９（それぞれ商品名）等を挙げることができる。
【０１７６】
本発明の配向膜付基板は、基板と配向膜との間に他の層が形成されたものであってもよく、例えば図１７に示すように、基板１上に、着色層９およびその境界部分に形成された遮光部（ブラックマトリックス）１３が設けられ、その上に透明電極層７が設けられ、その上に上記配向膜６が形成されたものであってもよい。
【０１７７】
このような本発明に用いられる着色層および遮光部は、通常カラーフィルタにおいて用いられるものであれば特に限定されるものではなく、着色層としては通常の顔料分散法等に用いられる赤、青、または緑の顔料を含有する感光性樹脂が好適に用いられ、遮光部としては、クロム等の金属やカーボンブラック等の遮光性を有する粒子が分散された樹脂等が好適に用いられる。
【０１７８】
また、透明電極層には、特に限定されるものはないが、一般的にはＩＴＯが好適に用いられる。
【０１７９】
Ｄ．液晶表示装置
最後に、本発明の液晶表示装置について説明する。本発明の液晶表示装置は、第１基板と、上記第１基板上に形成された着色層と、上記着色層上に形成された透明電極層と、上記透明電極層上に形成され、液晶層が接触する側の表面に、撥水領域とこの撥水領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを有しており、光触媒を含有し、かつ光触媒の作用により表面の濡れ性が変化する配向膜とを有するカラーフィルタ側基板、および、
第２基板と、上記第２基板上に形成された透明電極層と、上記透明電極層表面に形成され、液晶層が接触する側の表面に、撥水性領域とこの撥水性領域より水との接触角が小さい領域である親水性領域とからなる濡れ性パターンを有しており、光触媒を含有し、かつ光触媒の作用により表面の濡れ性が変化する配向膜とを有する対向基板を、
上記カラーフィルタ側基板の配向膜と、上記対向基板側の配向膜とが向かい合うように配置し、
上記二つの配向膜間に液晶を封入してなることを特徴とする。
【０１８０】
このような液晶表示装置は、撥水性領域内に親水性領域をパターン状に形成された配向膜を有するものであるので、例えば垂直配向モードの液晶表示装置においては、撥水性領域では垂直に配向する液晶分子が、親水性領域では傾く性質を利用することにより、垂直に配向した液晶分子の画素内での配向分割を可能とすることができる。
【０１８１】
このような液晶表示装置の一例を図１８に示す。まず、カラーフィルタが形成されているカラーフィルタ側基板は、第１基板４１上に通常は、赤、緑、および青のパターンを有する着色層９が形成されており、さらにその表面には透明電極層７が形成され、さらにその表面に上述したような配向膜６が形成されている。
【０１８２】
一方、カラーフィルタ側基板に対向する対向基板は、第２基板４２上に透明電極層７が形成され、さらにその表面に上述したような配向膜６が形成されている。
【０１８３】
なお、上記カラーフィルタ側基板の透明電極層もしくは対向基板側の透明電極層のいずれかが、アクティブマトリックス方式であってもよい。
【０１８４】
上記カラーフィルタ側基板の配向膜６と、対向基板側の配向膜６とが対向するように配置され、これらの間隙に液晶分子が封入されることにより液晶層８が形成され、本発明の液晶表示装置とされる。
【０１８５】
このような本発明の液晶表示装置に用いられる配向膜は、上記「Ａ．配向膜」において説明したものと同様であるので、ここでの説明は省略する。また、他の第１および第２基板は、上記「Ｂ．配向膜の製造方法」で説明した基板と同様であり、さらに、着色層および透明電極層、さらには液晶層に関しても、上記「Ｃ．配向膜付基板」で説明したものと同様であるので、ここでの説明は省略する。
【０１８６】
なお、本発明は、上記実施形態に限定されるものではない。上記実施形態は例示であり、本発明の特許請求の範囲に記載された技術的思想と実質的に同一な構成を有し、同様な作用効果を奏するものは、いかなるものであっても本発明の技術的範囲に包含される。
【０１８７】
【実施例】
以下、本発明について実施例を用いて具体的に説明する。
【０１８８】
［実施例１］
（ｉ）配向膜付基板の作製
（光触媒処理層の形成）
光触媒である酸化チタンの水分散体ＳＴ−Ｋ０１（石原産業（株）製）をカラーフィルタのＩＴＯ電極上にスピンコーターにより塗布し、１５０℃で１０分間の乾燥硬化処理し、透明な光触媒処理層を形成した。
【０１８９】
（濡れ性変化配向膜の形成）
フルオロアルキルシラン（ＧＥ東芝シリコーン製ＴＳＬ８２３３）５ｇ、テトラメトキシシラン２ｇ、１規定塩酸２ｇを８時間混合し、この溶液を上記光触媒処理層が形成されたカラーフィルタ上に塗布し、１５０℃１０分加熱することにより光触媒処理層を覆うように濡れ性変化配向膜を形成した。形成された濡れ性変化配向膜上の水との接触角は、１１２°であった。
【０１９０】
（露光）
上記濡れ性変化配向膜が形成されたカラーフィルタに、高圧水銀ランプ（散乱光）を用いて、マスクを介して７００ｍＪ／ｃｍ^２（３６５ｎｍ）のエネルギーを照射した。その結果、光が透過した部位のみ濡れ性が変化して、水の接触角が１０°以下となった。上記一連の操作により、濡れ性パターンが形成された配向膜付基板を得た。
【０１９１】
（ii）液晶表示装置の作製
上記の配向膜付基板を、同様にして得られた配向膜付基板と貼り合わせ接着した。その際、基板間の間隙を５μｍにするため、片方の配向膜付基板に、積水ファインケミカル製ＳＰシリーズを散布した。上下の基板の接着と液晶が充填される閉鎖空間を確保するため、外周にシール材を塗布し、プレスした後、熱硬化させた。
【０１９２】
上記基板間の間隙に、メルク社製ネガ型液晶材料ＭＬＣ６６０８を注入し、液晶層を形成した。この液晶材料は、負の誘電異方性を有し、電界印加すると分子長軸が電界方向と垂直になる性質がある。上記一連の操作により液晶表示装置を作製した。
【０１９３】
得られた液晶セルを偏光顕微鏡で観察したところ、初期配向は垂直配向が得られた。この液晶セルに電圧を印加したところ、親水性領域で予め傾斜した液晶分子を起点として傾き方向が定まり、液晶のダイレクタがほぼ平行になる様子が観察された。さらに、十分に電圧を印加すると、水平配向が得られた。
【０１９４】
［実施例２］
（ｉ）配向膜付基板の作製
（光触媒含有配向膜の形成）
フルオロアルキルシラン（ＧＥ東芝シリコーン製ＴＳＬ８２３３）５ｇ、テトラメトキシシラン２ｇ、１規定塩酸２ｇを８時間混合した溶液０．１ｇと光触媒である酸化チタンの水分散体ＳＴ−Ｋ０３（石原産業（株）製）５０ｇを混合し、この溶液をカラーフィルタのＩＴＯ電極上にスピンコーターにより塗布し、１５０℃で１０分間の乾燥硬化処理し、透明な光触媒含有配向膜を形成した。形成された光触媒含有配向膜上の水との接触角は１１０°であった。
【０１９５】
（露光）
上記光触媒含有配向膜が形成されたカラーフィルタに高圧水銀ランプ（散乱光）を用いて、マスクを介して６００ｍＪ／ｃｍ^２（３６５ｎｍ）のエネルギーを照射した。その結果、光が透過した部位のみ濡れ性が変化して、水の接触角が１０°以下となった。上記一連の操作により、濡れ性パターンが形成された配向膜付基板を得た。
【０１９６】
（ii）液晶表示装置の作製
実施例１と同様にして液晶表示装置を作製した。
【０１９７】
得られた液晶セルを偏光顕微鏡で観察したところ、初期配向は垂直配向が得られた。この液晶セルに電圧を印加したところ、親水性領域で予め傾斜した液晶分子を起点として傾き方向が定まり、液晶のダイレクタがほぼ平行になる様子が観察された。さらに、十分に電圧を印加すると、水平配向が得られた。
【０１９８】
［実施例３］
（ｉ）配向膜付基板の作製
（光触媒含有配向膜の形成）
ポリイミドが主成分である液晶配向膜材料サンエバーＳＥ−１２１１（日産化学製）１０ｇと光触媒である酸化チタンの水分散体ＳＴ−Ｋ０１（石原産業（株）製）をＩＰＡにて４倍希釈した溶液１０ｇを混合し、この溶液をカラーフィルタのＩＴＯ電極上にスピンコーターにより塗布し、１５０℃で１０分間の乾燥硬化処理し、透明な光触媒含有配向膜を形成した。形成された光触媒含有配向膜上の水との接触角は９９°であった。
【０１９９】
（露光）
上記光触媒含有配向膜が形成されたカラーフィルタに高圧水銀ランプ（散乱光）を用いて、マスクを介して１２００ｍＪ／ｃｍ^２（３６５ｎｍ）のエネルギーを照射した。その結果、光が透過した部位のみ濡れ性が変化して、水の接触角が１０°以下となった。上記一連の操作により、濡れ性パターンが形成された配向膜付基板を得た。
【０２００】
（ii）液晶表示装置の作製
実施例１と同様にして液晶表示装置を作製した。
【０２０１】
得られた液晶セルを偏光顕微鏡で観察したところ、初期配向は垂直配向が得られた。この液晶セルに電圧を印加したところ、親水性領域で予め傾斜した液晶分子を起点として傾き方向が定まり、液晶のダイレクタがほぼ平行になる様子が観察された。さらに、十分に電圧を印加すると、水平配向が得られた。
【０２０２】
【発明の効果】
本発明によれば、撥水性領域内に親水性領域をパターン状に形成して、撥水性領域では垂直に配向する液晶分子が、親水性領域では傾く性質を利用することにより、垂直に配向した液晶分子の画素内での配向分割を可能とするものであるので、このような配向膜を用いることにより、視角依存性の少ない液晶表示装置とすることができる。
【図面の簡単な説明】
【図１】垂直配向モードの液晶表示装置を説明するための説明図である。
【図２】画素内における配向分割が行われた垂直配向モード液晶表示装置の従来例を示す説明図である。
【図３】ＭＶＡモードに用いる配向膜に用いられる親水性パターンを示す平面図である。
【図４】図３に示す親水性パターン上に液晶分子を配置した例を示す平面図である。
【図５】図４に示す例を断面から見た状態を示す概略断面図である。
【図６】ＩＰＳモードに用いる配向膜に用いられる親水性パターンを示す平面図である。
【図７】図６に示す親水性パターン上に液晶分子を配置した例を示す平面図である。
【図８】図７に示す例を断面から見た状態を示す概略断面図である。
【図９】ＴＮモードに用いる配向膜に用いられる親水性パターンを示す平面図である。
【図１０】図９に示す親水性パターン上に液晶分子を配置した例を示す平面図である。
【図１１】図１０に示す例を断面から見た状態を示す概略断面図である。
【図１２】本発明に用いられる光触媒配向膜用基板の一例を示す概略断面図である。
【図１３】本発明に用いられる光触媒配向膜用基板の他の例を示す概略断面図である。
【図１４】本発明に用いられる光触媒配向膜用基板の他の例を示す概略断面図である。
【図１５】本発明の配向膜付基板の一例を示す概略断面図である。
【図１６】本発明の配向膜付基板の他の例を示す概略断面図である。
【図１７】本発明の配向膜付基板の他の例を示す概略断面図である。
【図１８】本発明の液晶表示装置の一例を示す概略断面図である。
【符号の説明】
１ … 基板
２ … 光触媒含有配向膜
４ … 光触媒処理層
５ … 濡れ性変化配向膜
６ … 配向膜
７ … 透明電極層
８ … 液晶層
９ … 着色層
３１ … 撥水性領域
３２ … 親水性領域
４１ … 第１基板（カラーフィルタ側基板）
４２ … 第２基板（対向基板）[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an alignment film that can align liquid crystal molecules in a suitable direction with respect to a substrate and is advantageous in terms of cost. In particular, the alignment division within a pixel is easy in order to improve visual field characteristics. The present invention relates to an alignment film that has been made possible, a substrate with an alignment film provided with the alignment film, and a liquid crystal display device using the substrate with an alignment film.
[0002]
[Prior art]
A liquid crystal cell is a display element that utilizes electro-optic changes in liquid crystal. Its characteristics are small, lightweight, and low power consumption. In recent years, it has made remarkable progress as a display device for various displays. ing. Among them, nematic liquid crystal having positive dielectric anisotropy is used, and so-called homogeneous alignment in which liquid crystal molecules are arranged parallel to the substrate is taken at each interface between a pair of opposing electrode substrates. A typical example is a twisted nematic (TN type) field effect liquid crystal cell in which both substrates are combined so that the alignment directions are orthogonal to each other.
[0003]
On the other hand, when nematic liquid crystal having negative dielectric anisotropy is used, the so-called homeotropic alignment in which liquid crystal molecules are arranged perpendicularly to the substrate is taken at the respective interfaces of a pair of opposing electrode substrates, and voltage is applied. Electric field-controlled birefringence type (ECB type) using the change in birefringence of the liquid crystal layer when applied, phase transition type (PC type) using the phase structure change of liquid crystal, guest / host type mixed with dye molecules Many field effect liquid crystal cells such as (GH type) are known.
[0004]
Such a vertical alignment type liquid crystal display device will be briefly described with reference to FIG. The vertical alignment method is a method in which a negative liquid crystal material having a negative dielectric anisotropy and a vertical alignment film are combined. As shown in FIG. 1 (1), the liquid crystal molecules 21 are vertical when no voltage is applied. Oriented in the direction, black display. As shown in (3) of FIG. 1, when a predetermined voltage is applied, the liquid crystal molecules 21 are aligned in the horizontal direction and white display is obtained. Such a vertical alignment method has advantages such as higher display contrast and faster black-and-white level response speed than the TN method.
[0005]
However, when halftone display is performed using the vertical alignment method, there is a problem that the viewing angle depends on the display state. That is, when displaying a halftone by the vertical alignment method, a voltage smaller than that for white display is applied. In this case, the liquid crystal molecules 21 are aligned in an oblique direction as shown in FIG. become. In this case, as shown in the drawing, the liquid crystal molecules are aligned in parallel with respect to the light 52 traveling from the lower right to the upper left. Therefore, since the liquid crystal hardly exhibits the birefringence effect, it looks black when viewed from the left side. On the other hand, since the liquid crystal molecules are aligned vertically with respect to the light 52 from the lower left to the upper right, the liquid crystal exhibits a large birefringence effect on the incident light, resulting in a display close to white. Thus, the vertical alignment method has a problem that the viewing angle depends on the display state.
[0006]
In order to solve such a problem, it is known that the viewing angle characteristic is improved by dividing the alignment direction of liquid crystal molecules into a plurality of different directions in a pixel. For example, a vertical alignment method in which an opening is provided in a portion of the counter electrode facing the center of the pixel electrode to generate a portion where the electric field is inclined at the center of the pixel, and the alignment direction of the liquid crystal molecules is divided into two or four directions. A liquid crystal display device is disclosed (Patent Document 1). However, the liquid crystal display device disclosed in Patent Document 1 has a problem that the response speed is slow, and it has been found that the response speed is particularly slow when changing from a state where no voltage is applied to a state where the voltage is applied. This seems to be because it takes time until the alignment of all the liquid crystals in the region is aligned because the length of the continuous region formed in the pixel in the alignment direction is about half the length of the pixel.
[0007]
On the other hand, a vertical alignment type liquid crystal display device that divides the alignment direction of liquid crystal into a plurality of regions in a pixel by providing inclined surfaces having different directions on electrodes is disclosed (Patent Document 2). However, in the disclosed configuration, since the inclined surface is provided for the entire pixel, all liquid crystals that contact the alignment surface are aligned along the inclined surface when no voltage is applied, so that a complete black display can be obtained. There was a problem that the contrast was lowered. Moreover, since the inclined surface is provided in the whole pixel, it was found that the inclined surface is loose and is not sufficient for defining the alignment direction of the liquid crystal. To make the inclined surface steep, it is necessary to increase the thickness of the structure. However, if the thickness of the dielectric structure is increased, charges are accumulated in the structure during the operation of the device, and the voltage between the electrodes is caused by the accumulated charge. It has been found that a so-called burn-in phenomenon occurs in which the direction of liquid crystal molecules does not change even when a voltage is applied.
[0008]
Furthermore, as a solution to such problems, a technique of forming a protrusion on a substrate is disclosed as a domain regulating means (Patent Document 3). FIG. 2 is a diagram for explaining the principle. As shown in (1) of FIG. 2, the liquid crystal molecules 21 are aligned perpendicularly to the substrate surface when no voltage is applied. When an intermediate voltage is applied, an oblique electric field is generated at the electrode slit part (electrode edge part) with respect to the substrate surface as shown in FIG. Further, the liquid crystal molecules of the protrusions 22 are slightly tilted from the state where no voltage is applied. The tilt direction of the liquid crystal molecules is determined by the influence of the inclined surface of the protrusion and the oblique electric field, and the alignment direction of the liquid crystal is divided in the middle of the protrusion 22 and the slit. At this time, for example, the light 52 that is transmitted from directly below to above is slightly inclined by liquid crystal molecules, so that transmission is suppressed due to the influence of a slight birefringence, and a gray halftone display is obtained. The light 52 transmitted from the lower right to the upper left is difficult to transmit in the region where the liquid crystal is tilted to the left, and is very easily transmitted in the region tilted to the right. On average, a gray halftone display is obtained. The light 52 transmitted from the lower left to the upper right is also displayed in gray on the same principle, and a uniform display can be obtained in all directions. Further, as shown in (3) of FIG. 2, when a predetermined voltage is applied, the liquid crystal molecules 21 become almost horizontal, and a white display is obtained. Therefore, in all the black, halftone, and white display states, a good display with little viewing angle dependency can be obtained.
[0009]
However, in such a method, since it is necessary to form a structure such as a protrusion on the liquid crystal substrate, the manufacturing process is complicated, the cost is increased, and the yield is reduced. .
[0010]
[Patent Document 1]
JP-A-6-301036
[Patent Document 2]
JP 7-199193 A
[Patent Document 3]
Patent Publication No. 2947350
[0011]
[Problems to be solved by the invention]
The present invention has been made in view of the above problems, and it is possible to perform suitable alignment of liquid crystal molecules without forming a structure such as the above-described protrusions or without rubbing. The main purpose is to provide an alignment film.
[0012]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a wettability pattern comprising a water repellent region and a hydrophilic region having a smaller contact angle with water than the water repellent region on the surface on which the liquid crystal layer contacts. An alignment film characterized by comprising a photocatalyst alignment film which contains a photocatalyst and whose surface wettability changes by the action of the photocatalyst is provided.
[0013]
Thus, by forming a hydrophilic region in a pattern in the water-repellent region, for example, in a vertical alignment mode liquid crystal display device, liquid crystal molecules that are vertically aligned in the water-repellent region are inclined in the hydrophilic region. By using this, it is possible to divide the alignment of vertically aligned liquid crystal molecules within the pixel. Therefore, by using such an alignment film, it is possible to easily perform alignment division within the pixel, and a liquid crystal display device with less viewing angle dependency can be obtained by the same action as the example in which the protrusions are formed.
[0014]
In the said invention, it is preferable that the said photocatalyst alignment film consists of a photocatalyst containing alignment film which has a binder and a photocatalyst. Or it is preferable that the said photocatalyst alignment film consists of a photocatalyst processing layer which has a photocatalyst, and the wettability change alignment film formed on the said photocatalyst processing layer.
[0015]
Moreover, in the said invention, it is preferable that the contact angle with the water in the said water-repellent area | region is larger in the range of 10 degrees-120 degrees than the contact angle with the water in the said hydrophilic area | region. This is because, when the difference in wettability between the water repellent region and the hydrophilic region is within the above range, the alignment division of the liquid crystal molecules within the pixel can be more effectively performed.
[0016]
Furthermore, in the said invention, it is preferable that the contact angle with the water in the said water-repellent area | region is in the range of 40 degrees-120 degrees. For example, when used in a liquid crystal display device in a vertical alignment mode, in order to align liquid crystal molecules vertically in a water repellent region, it is preferable to have the above-described water repellency.
[0017]
In the above invention, the photocatalyst-containing alignment film or the wettability changing alignment film has polyimide, polyamide, or organopolysiloxane as a main chain, and a linear alkyl group having 4 to 22 carbon atoms as a side chain. Or it consists of a compound which has a fluorine-containing alkyl group, and it is preferable that the density of the side chain in the said water repellent area | region is larger than the density of the side chain in the said hydrophilic area | region.
[0018]
For example, when used in a vertical alignment mode liquid crystal display device, as described above, the present invention utilizes the property that liquid crystal molecules are vertically aligned in a water-repellent region and liquid crystal molecules are inclined in a hydrophilic region. Furthermore, it is preferable to use a film in which a side chain for vertically aligning liquid crystal molecules is formed on the alignment film surface in order to improve the alignment characteristics of the liquid crystal molecules. From such a point of view, an alignment film made of the above-described compound is preferable. Further, in the hydrophilic region, it is preferable that the liquid crystal molecules are tilted. Therefore, the density of the side chain is higher in the hydrophilic region than in the water-repellent region. It is preferable to form smaller.
[0019]
Furthermore, in the said invention, it is preferable in the said water-repellent area | region that the weight of the said side chain has 5 weight% or more with respect to the total weight. This is because having such a side chain has sufficient vertical alignment characteristics as an alignment film.
[0020]
In the above invention, the organopolysiloxane is a polysiloxane containing a fluoroalkyl group, and the organopolysiloxane is Y_nSiX_(4-n)Wherein Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group or a halogen, and n is an integer from 0 to 3. It is preferable that it is the organopolysiloxane which is a 1 type, or 2 or more types of hydrolyzed condensate or cohydrolyzed condensate of the silicon compound. By using such an organopolysiloxane and treating with a photocatalyst as described later, it is possible to form a hydrophilic region in the water-repellent region relatively easily, and the water-repellent region and the hydrophilic region This is because the difference in the wettability of the liquid crystal molecules can be greatly increased, which is preferable for the purpose of the alignment division in the pixel of the liquid crystal molecules.
[0021]
Furthermore, in the said invention, the said polyimide makes the polyimide precursor containing a linear alkyl group by reaction-polymerizing at least the tetracarboxylic acid component and the diamine component containing a linear alkyl group, It is preferable that it is a polyimide formed by imidizing. This is because such a polyimide has been conventionally used as an alignment film, and there is very little possibility of problems occurring when the alignment film is formed using this material.
[0022]
In the present invention, a photocatalyst alignment film forming step of forming a photocatalyst alignment film comprising a photocatalyst-containing alignment film that is formed on a substrate, has a photocatalyst and a binder, and whose surface wettability is changed by the action of the photocatalyst, and By irradiating energy in a pattern on the photocatalyst-containing alignment film, a wettability pattern comprising a water-repellent region and a hydrophilic region in which the contact angle with water is smaller than the water-repellent region on the photocatalyst-containing alignment film And a wettability pattern forming step for forming an alignment film.
[0023]
Thus, it is possible to form a pattern with different wettability consisting of a water-repellent region and a hydrophilic region on the photocatalyst-containing alignment film only by irradiating energy using the photocatalyst-containing alignment film. A wettability pattern can be easily formed on the alignment film, and alignment division within the pixel can be performed. Thereby, it has the advantage that it can manufacture more easily than methods, such as forming structures, such as a projection part, for example.
[0024]
Further, in the present invention, a photocatalytic alignment comprising a photocatalyst treatment layer formed on a substrate and containing a photocatalyst, and a wettability changing alignment film formed on the photocatalyst treatment layer and whose surface wettability is changed by the photocatalyst. A photocatalytic alignment film forming step for forming a film and a contact angle between the water repellent region on the wettability changing alignment film and water from the water repellent region by irradiating the wettability changing alignment film with energy in a pattern. And providing a wettability pattern forming step of forming a wettability pattern including a hydrophilic region which is a small region.
[0025]
In this way, it is possible to form a pattern with different wettability consisting of a water-repellent region and a hydrophilic region on the wettability changing alignment film only by irradiating energy using the photocatalyst treatment layer. A wettability pattern can be easily formed on the alignment film, and alignment division within the pixel can be performed. Thereby, it has the advantage that it can manufacture more easily than methods, such as forming structures, such as a projection part, for example.
[0026]
In the above invention, the photocatalyst-containing alignment film or the wettability changing alignment film has polyimide, polyamide, or organopolysiloxane as a main chain, and an alkyl group or fluorine-containing alkyl having 4 to 22 carbon atoms as a side chain. It preferably consists of a compound having a group. As described above, it may be difficult to align liquid crystal molecules vertically with only water repellency. Therefore, an alignment film having better alignment characteristics can be produced by using the compound having a side chain as described above as the alignment film.
[0027]
Furthermore, in the said invention, the said photocatalyst is a titanium oxide (TiO2).₂), Zinc oxide (ZnO), tin oxide (SnO)₂), Strontium titanate (SrTiO)₃), Tungsten oxide (WO₃), Bismuth oxide (Bi₂O₃), And iron oxide (Fe₂O₃It is preferable that the substance is one or more substances selected from the group consisting of a titanium oxide (TiO 2).₂) Is preferable. This is because titanium dioxide has a high band gap energy and is effective as a photocatalyst, and is chemically stable, non-toxic and easily available.
[0028]
Moreover, in the said invention, it is preferable that the contact angle with the water in the said water-repellent area | region is a thing larger within the range of 10 degrees-120 degrees than the contact angle with the water in the said hydrophilic area | region. This is because, when the difference in wettability between the water repellent region and the hydrophilic region is within the above range, the alignment division of the liquid crystal molecules within the pixel can be more effectively performed.
[0029]
Furthermore, in the said invention, it is preferable that the contact angle with the water in the said water-repellent area | region is in the range of 40 degrees-120 degrees. This is because in order to align the liquid crystal molecules vertically in the water repellent region, it is preferable to have the above-described water repellency.
[0030]
In the present invention, a substrate and a hydrophilic region that is formed on the substrate and is in contact with the liquid crystal layer have a water-repellent region and a hydrophilic region that has a smaller contact angle with water than the water-repellent region. There is provided an alignment film-attached substrate having a wettability pattern comprising: an alignment film containing a photocatalyst and having a surface wettability changed by the action of the photocatalyst. Thus, by having an alignment film in which a hydrophilic region is formed in a pattern in the water-repellent region, for example, when used in a liquid crystal display device in a vertical alignment mode, liquid crystal molecules that are vertically aligned in the water-repellent region. By utilizing the property of tilting in the hydrophilic region, it is possible to make alignment division within the pixel of vertically aligned liquid crystal molecules.
[0031]
Furthermore, in the said invention, even if the liquid crystal layer is arrange | positioned at the surface side of the said alignment film, the colored layer is formed in the said substrate surface, A transparent electrode layer is formed in this colored layer surface. It may be formed, and the alignment film may be formed on the transparent electrode layer.
[0032]
In the present invention, the first substrate, the colored layer formed on the first substrate, the transparent electrode layer formed on the colored layer, the liquid crystal layer formed on the transparent electrode layer, The surface on the contact side has a wettability pattern consisting of a water-repellent region and a hydrophilic region, which is a region having a smaller contact angle with water than this water-repellent region, contains a photocatalyst, and acts as a photocatalyst And a color filter side substrate having an alignment film whose surface wettability changes, and
A second substrate, a transparent electrode layer formed on the second substrate, and a surface formed on the surface of the transparent electrode layer, on the side in contact with the liquid crystal layer, are provided with a water repellent region and water from the water repellent region. A counter substrate having a wettability pattern composed of a hydrophilic region, which is a region having a small contact angle, and having an alignment film containing a photocatalyst and whose surface wettability is changed by the action of the photocatalyst,
Arranged so that the alignment film on the color filter side substrate and the alignment film on the opposite substrate side face each other,
A liquid crystal display device comprising a liquid crystal sealed between the two alignment films is provided.
[0033]
Since such a liquid crystal display device has an alignment film in which hydrophilic regions are formed in a pattern in the water repellent region, for example, in a liquid crystal display device in a vertical alignment mode, the water repellent region is vertically aligned. By utilizing the property that the liquid crystal molecules to be tilted in the hydrophilic region, the alignment of vertically aligned liquid crystal molecules can be made possible within the pixel.
[0034]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be specifically described. The present invention includes an alignment film, a method for manufacturing the alignment film, a substrate with an alignment film, and a liquid crystal display device. Hereinafter, each item will be described separately.
[0035]
A. Alignment film
The alignment film of the present invention has a wettability pattern consisting of a water-repellent region and a hydrophilic region, which is a region having a smaller contact angle with water than the water-repellent region, on the surface that is in contact with the liquid crystal layer. And a photocatalyst alignment film which contains a photocatalyst and whose surface wettability changes by the action of the photocatalyst.
[0036]
In the present invention, it is possible to perform alignment division in the same pixel by forming the hydrophilic film pattern in the water repellent region in the alignment film surface as described above. This is due to the following reason.
[0037]
That is, for example, in a liquid crystal display device in a vertical alignment mode (hereinafter sometimes referred to as MVA mode), a hydrophilic region is formed in a predetermined pattern on a surface having water repellency of an alignment film in a region where pixels are formed. Form. The liquid crystal molecules are aligned vertically in the water-repellent region due to their properties, but are slightly inclined in the hydrophilic region. Therefore, by adjusting the wettability degree, shape, and the like of the hydrophilic region, it is possible to control the alignment direction of the liquid crystal molecules to be two different directions or four different directions in the same pixel. Therefore, by using such an alignment film, a liquid crystal display device with less viewing angle dependency can be obtained.
[0038]
In addition, when liquid crystal molecules such as IPS mode and TN mode are arranged in parallel to the substrate, the liquid crystal molecules are aligned along the hydrophilic region pattern, thereby forming a striped hydrophilic region pattern. By doing so, alignment of liquid crystal molecules can be performed. In the present invention, this has the advantage that the alignment film can be formed without performing the conventional rubbing process.
[0039]
The alignment film of the present invention includes a photocatalyst alignment film comprising a photocatalyst-containing alignment film having a binder and a photocatalyst (first embodiment), a photocatalyst treatment layer in which the photocatalyst alignment film has a photocatalyst, and the photocatalyst. There are two embodiments, one consisting of a wettability changing alignment film formed on the treatment layer (second embodiment). Hereinafter, each embodiment will be described separately.
[0040]
1. First embodiment
First, the first embodiment of the alignment film of the present invention will be described. The first embodiment of the alignment film of the present invention is characterized in that the photocatalyst alignment film comprises a photocatalyst-containing alignment film having a binder and a photocatalyst. Each configuration of the alignment film of this embodiment will be described.
[0041]
(1) Water repellent area and hydrophilic area
The alignment film of the present invention is characterized in that a wettability pattern composed of a water repellent region and a hydrophilic region is formed on the surface on the side in contact with the liquid crystal layer as described above. The hydrophilic region is not particularly limited as long as the contact angle with water is smaller than that of the water-repellent region, and the wettability in the hydrophilic region may be uniform or non-uniform. Good.
[0042]
Further, the difference in wettability with the water repellent region is not particularly limited, but from the viewpoint of ease of controlling the orientation direction, the contact angle with water in the water repellent region and the water in the hydrophilic region It is preferable that the difference from the contact angle is in the range of 10 ° to 120 °, particularly in the range of 60 ° to 120 °.
[0043]
It is preferable that the material for forming the hydrophilic region and the water-repellent region is usually the same, and the surface of the material is subjected to a surface treatment using a photocatalyst described later to cause a difference in wettability. However, the present invention is not particularly limited to this, and the hydrophilic region and the water repellent region may be formed of different materials.
[0044]
The pattern shape of the hydrophilic region in the region where the pixel is formed may be various depending on the type of liquid crystal display device in which the alignment film is used.
[0045]
For example, the MVA mode liquid crystal display device may have any pattern as long as the alignment direction of the liquid crystal molecules can be divided and controlled in a plurality of directions in the pixel. This shape differs depending on the difference in wettability between the hydrophilic region and the water-repellent region, the type of liquid crystal molecules, and the like, and is appropriately determined according to each condition.
[0046]
Specifically, as shown in FIG. 3, a pattern in which hydrophilic regions 32 are arranged in a wedge shape can be exemplified. In FIG. 3, reference numeral 41 denotes an upper substrate which is a color filter side substrate, and 42 denotes a lower substrate which is a counter substrate. In the case of the pattern as shown in FIG. 3, as shown in FIG. 4 (1) or FIG. 5 (1), the liquid crystal molecules 21 arranged vertically in the absence of an electric field are converted into those shown in FIG. 4 (2) or FIG. As shown in 2), by applying an electric field 51, alignment is performed along this wedge-shaped pattern, so that the alignment direction of the liquid crystal molecules is controlled to be different from the four directions in the same pixel. Therefore, a liquid crystal display device with less viewing angle dependency can be obtained. Such a hydrophilic region pattern is preferably formed in a pattern on both the color filter side substrate 41 and the opposite side substrate 42. FIG. 5 shows a state in which liquid crystal molecules are viewed from a cross section, and in the figure, 7 indicates an electrode layer.
[0047]
In the IPS mode liquid crystal display device, as shown in FIG. 6, the hydrophilic regions 32 are patterned in a stripe shape. In this case, for example, the upper substrate 41 which is a color filter side substrate and the counter substrate are used. The stripes are formed in parallel with the lower substrate 42. In this way, the stripe pattern of the hydrophilic region is formed in parallel between the upper substrate and the lower substrate, so that the liquid crystal molecules 21 can be obtained in the absence of an electric field as shown in FIG. 7 (1) or FIG. 8 (1). It is in a state of being oriented parallel to the hydrophilic region. Further, as shown in FIG. 7B or FIG. 8B, when the electric field 51 is applied, the liquid crystal molecules 21 are oriented so as to intersect the stripe pattern of the hydrophilic region. FIG. 8 shows a state in which liquid crystal molecules are viewed from a cross section, and in the figure, 7 indicates an electrode layer.
[0048]
By forming hydrophilic regions in stripes in this way, liquid crystal molecules can be aligned without performing a rubbing process on the alignment film.
[0049]
Furthermore, in the TN mode liquid crystal display device, as shown in FIG. 9, the hydrophilic region 32 is patterned in a stripe shape. However, in the TN mode, for example, it is opposed to the upper substrate 41 which is a color filter side substrate. The stripes are formed so as to be orthogonal to the lower substrate 42 which is a substrate. By forming the hydrophilic region stripe patterns so as to be orthogonal to each other between the upper substrate and the lower substrate, the liquid crystal molecules 21 are in an electric field-free state as shown in FIG. 10 (1) or FIG. 11 (1). Then, the orientation is twisted 90 degrees from the lower substrate to the upper substrate. As shown in FIG. 10B or FIG. 11B, when an electric field 51 is applied, the liquid crystal molecules 21 are aligned perpendicular to the substrate. This state is shown in FIG. 11 showing a state where the liquid crystal molecules are viewed from the cross section. In FIG. 11, 7 indicates an electrode layer.
[0050]
Also in this case, it can be used as an alignment film that can align liquid crystal molecules without rubbing the alignment film.
[0051]
In addition, the area ratio between the hydrophilic region and the water-repellent region in the region where the pixels are formed is also greatly different depending on the type and conditions of the liquid crystal display device used, as in the above-described pattern shape of the hydrophilic region. However, from the viewpoint that control is usually difficult when the hydrophilic region is too large, the range in which 0.1% to 90% is set when the region where the pixel is formed is defined as 100%, particularly 0.1%. A hydrophilic region is formed within the range of 50% to 50%.
[0052]
On the other hand, the water-repellent region is usually a region where the surface treatment using the photocatalyst as described above is not performed, but the present invention is not limited to this. A pattern may be formed.
[0053]
Such a water repellent region is not particularly limited as long as it has a higher contact angle with water than the hydrophilic region as described above. However, in order to align liquid crystal molecules vertically, a predetermined repellent property is not required. It is preferable to have water. From such a viewpoint, the contact angle with water in the water-repellent region in the present invention is preferably in the range of 40 ° to 120 °, particularly in the range of 70 ° to 120 °.
[0054]
In addition, the contact angle with water in the present invention is the measurement of the contact angle with water using a contact angle measuring device (CA-Z type manufactured by Kyowa Interface Science Co., Ltd.). 30 seconds later).
[0055]
(2) Photocatalyst-containing alignment film
The photocatalyst-containing alignment film used in this embodiment is composed of a binder and a photocatalyst, and the wettability is changed by the action of the photocatalyst. A binder and a photocatalyst constituting such a photocatalyst-containing alignment film will be described.
[0056]
a. Binder
First, the binder used in this embodiment will be described. In this embodiment, when the wettability change on the photocatalyst-containing alignment film is performed by the photocatalyst acting on the binder itself (first aspect), it is decomposed by the action of the photocatalyst by energy irradiation, thereby containing the photocatalyst. Three cases of changing by adding a decomposition substance capable of changing the wettability on the alignment film to the photocatalyst-containing alignment film (second embodiment) and combining them (third embodiment) It can be divided into one aspect. The binder used in the first and third aspects must have a function capable of changing the wettability on the photocatalyst-containing alignment film by the action of the photocatalyst. In the second aspect, such a binder is used. No special functions are necessary.
[0057]
Hereinafter, the binder used in the first and third embodiments, that is, the binder having a function of changing the wettability on the photocatalyst-containing alignment film by the action of the photocatalyst will be described, and then used in the second embodiment. The binder to be used, that is, the binder that does not particularly require the function of changing the wettability on the photocatalyst-containing alignment film by the action of the photocatalyst will be described.
[0058]
(A-1) 1st aspect and 3rd aspect
The binder used in the first and third embodiments is not particularly limited as long as the wettability is changed by the action of the photocatalyst. However, a polymer material having a predetermined side chain is preferably used for the following reason.
[0059]
First, as will be described later, in the present invention, it is preferable to form a pattern comprising a hydrophilic region by subjecting the surface of the water-repellent region to a surface treatment with a photocatalyst. It is preferable to have a group or a fluorine-containing alkyl group in the side chain because a difference in wettability due to surface treatment tends to occur.
[0060]
Further, as described above, in the water-repellent region in the present invention, it is preferable that the liquid crystal molecules are aligned vertically, but in addition to the water-repellent property of the alignment film, it has a predetermined side chain, which is rubbed This is because the liquid crystal molecules can be aligned more effectively.
[0061]
Such a side chain is not particularly limited, but is a linear alkyl group or a fluorine-containing alkyl group having 4 to 22 carbon atoms, preferably 5 to 10 carbon atoms.
[0062]
In the water-repellent region, the weight of the side chain is preferably 5% by weight or more based on the total weight. This is because if the density of the side chain is about this level, the alignment ability of the liquid crystal molecules can be sufficiently exhibited.
[0063]
On the other hand, the main chain having such a side chain is not particularly limited, but is preferably a polyimide system, a polyamide system, or a polysiloxane system.
[0064]
Hereinafter, preferred materials for such a binder will be described separately for polyimide, polyamide, or polysiloxane.
[0065]
(Polyimide type)
As a polyimide resin used for the binder of this embodiment, polyimide is a polyimide precursor containing a linear alkyl group by reactive polymerization of at least a tetracarboxylic acid component and a diamine component containing a linear alkyl group. It is preferable that it is the polyimide which makes a body and imidizes this.
[0066]
In this embodiment, for example, polyimide disclosed in JP-A-6-3678 can be used. That is, the polyimide containing a linear alkyl group has a tetracarboxylic acid component and a diamine component not containing a linear alkyl group and / or a diamine component containing a linear alkyl group and / or a linear alkyl group. It is a polyimide obtained by imidating a polyimide precursor containing a linear alkyl group by reactive polymerization of a monoamine component and / or a dicarboxylic acid component containing a linear alkyl group. .
[0067]
Specifically, a polyimide containing no linear alkyl group may be mixed with a diimide compound containing a linear alkyl group, and a polyimide containing a linear alkyl group in the polyimide side chain may be used. It may be used, and a linear alkyl group may be reacted with a molecular chain terminal of a polyimide that does not contain a linear alkyl group. However, in order to obtain the stable vertical alignment which is the object of the present invention, the linear alkyl group must have 12 or more carbon atoms and the content thereof should be 5% or more based on the weight of the alkyl group with respect to the total polyimide weight. I must.
[0068]
The tetracarboxylic acid component used for obtaining the polyimide used in this embodiment is not particularly limited. Specific examples thereof include pyromellitic acid, 2,3,6,7-naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5,6-anthracenetetracarboxylic acid, 3,3 ', 4,4'-biphenyltetracarboxylic acid, 2,3,3', 4- Biphenyltetracarboxylic acid, bis (3,4-dicarboxyphenyl) ether, 3,3 ′, 4,4′-benzophenonetetracarboxylic acid, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4- Dicarboxyphenyl) methane, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1,1,3,3,3-hexafluoro-2,2-bis (3,4-dicarboxyphenyl) ) Propane, bis (3,4-dicarboxyphenyl) dimethylsilane, bis (3,4-dicarboxyphenyl) diphenylsilane, 2,3,4,5-pyridinetetracar Acids, aromatic tetracarboxylic acids such as 2,6-bis (3,4-dicarboxyphenyl) pyridine and their dianhydrides and their dicarboxylic acid diacid halides, 1,2,3,4-cyclobutane Tetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 2,3,5-tricarboxycyclopentylacetic acid, 3,4-dicarboxy-1 , 2,3,4-Tetrahydro-1-naphthalene succinic acid and other alicyclic tetracarboxylic acids and their dianhydrides and their dicarboxylic acid diacid halides, 1,2,3,4-butanetetracarboxylic acid And aliphatic tetracarboxylic acids and their dianhydrides and their dicarboxylic acid diacid halides.
[0069]
In particular, alicyclic tetracarboxylic acids and their dianhydrides and their dicarboxylic acid diacid halides are preferable from the viewpoint of the transparency of the coating film, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride is more preferable. Things are preferred. Moreover, 1 type, or 2 or more types of these tetracarboxylic acid and its derivative (s) can also be mixed and used.
[0070]
The diamine component which does not contain a linear alkyl group used for obtaining the polyimide used in this embodiment is a diamine generally used for polyimide synthesis, and is not particularly limited.
[0071]
For example, p-phenylenediamine, m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3 , 3'-dimethoxy-4,4'-diaminobiphenyl, diaminodiphenylmethane, diaminodiphenyl ether, 2,2-diaminodiphenylpropane, bis (3,5-diethyl-4-aminophenyl) methane, diaminodiphenylsulfone, diaminobenzophenone, Diaminonaphthalene, 1,4-bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1,3-bis (4- Aminophenoxy) benzene, 4,4'-bis (4-aminophenoxy) diphenyl sulfone, 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis (4-aminophenyl) hexa Aromatic diamine such as fluoropropane, 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane, etc. Alicyclic diamines and aliphatic diamines such as tetramethylene diamine and hexamethylene diamine,
[0072]
[Chemical 1]

[0073]
(Wherein n represents an integer of 1 to 10) and the like.
[0074]
Moreover, 1 type, or 2 or more types of these diamines can also be mixed and used. Specific examples of the diamine component containing a linear alkyl group used for obtaining the polyimide used in this embodiment are diaminobenzene derivatives as shown in the following chemical formula (2), diamino as shown in the chemical formula (3). Biphenyl derivatives, diaminoterphenyl derivatives such as chemical formula (4), diaminodiphenyl ether derivatives such as chemical formula (5), diphenylmethane derivatives such as chemical formula (6), bis (aminophenoxy) phenyl derivatives such as chemical formula (7) R is a linear alkyl group having 12 or more carbon atoms, an alkyloxy group, an alkyloxymethylene group, or the like.
[0075]
[Chemical 2]

[0076]
Moreover, 1 type, or 2 or more types of these alkyldiamines can also be mixed and used. Specific examples of monoamines containing linear alkyl groups used to obtain the polyimide used in this embodiment include aliphatic amines such as chemical formula (8) below and alicyclic rings such as chemical formula (9). Examples thereof include aromatic diamines such as formula diamine and chemical formula (10), and R is a linear alkyl group having 12 or more carbon atoms, alkyloxy group, alkyloxymethylene group, and the like.
[0077]
Moreover, 1 type, or 2 or more types of these alkyldiamines can also be mixed and used.
[0078]
[Chemical 3]

[0079]
Specific examples of the dicarboxylic acid component containing a linear alkyl group used to obtain the polyimide used in this embodiment include aliphatic dicarboxylic acids such as the following chemical formula (11) and their acid anhydrides and their And acid halide, alicyclic dicarboxylic acid such as chemical formula (12) and its acid anhydride and its acid halide, aromatic dicarboxylic acid such as chemical formula (13) and its acid anhydride and its acid halide, and R Is a linear alkyl group having 12 or more carbon atoms, an alkyloxy group, an alkyloxymethylene group, or the like.
[0080]
Moreover, 1 type, or 2 or more types of these dicarboxylic acid components can also be mixed and used.
[0081]
[Formula 4]

[0082]
After reacting and polymerizing a tetracarboxylic acid component and a diamine component to form a polyimide resin precursor, this is dehydrated and ring-closed imidized. As the tetracarboxylic acid component used in this case, a tetracarboxylic dianhydride is generally used. Is. The ratio of the total number of moles of tetracarboxylic dianhydride to the total number of moles of the diamine component is preferably 0.8 to 1.2. Similar to the normal polycondensation reaction, the closer the molar ratio is to 1, the greater the degree of polymerization of the polymer produced.
[0083]
If the degree of polymerization is too small, the strength of the polyimide film is insufficient when used as an alignment film, and the alignment of the liquid crystal becomes unstable. On the other hand, if the degree of polymerization is too large, the workability at the time of forming the polyimide resin film may deteriorate. Therefore, the polymerization degree of the product in this reaction is 0.05 to 3.0 dl / g (concentration 0.5 g / dl in N-methylpyrrolidone at a temperature of 30 ° C.) in terms of reduced viscosity of the polyimide precursor solution. Is preferred.
[0084]
Further, as one method for obtaining a polyimide containing a linear alkyl group used in this embodiment, there is a method of mixing a diimide compound containing a linear alkyl group. In order to obtain this diimide compound, a dicarboxylic acid component containing a linear alkyl group and a diamine component are reacted at a molar ratio of 2 to 1 to obtain a diimide compound precursor, which is then subjected to dehydration ring-closing imidization and / or There is a method in which a monoamine component containing a linear alkyl group and a tetracarboxylic dianhydride are reacted at a molar ratio of 2 to 1 to obtain a diimide compound precursor, which is then subjected to dehydration and ring-closing imidization.
[0085]
Furthermore, as one method for obtaining a polyimide containing a linear alkyl group of this embodiment, there is a method of introducing a linear alkyl group into the molecular chain terminal of the polyimide. In this case, when the tetracarboxylic acid component and the diamine component are reacted and polymerized, the method of reacting the dicarboxylic acid component containing a linear alkyl group and / or the tetracarboxylic acid component and the diamine component are combined. There is a method of reacting a monoamine component containing a linear alkyl group when reacting or polymerizing. When the dicarboxylic acid component containing a linear alkyl group is reacted, the ratio of the total mole number a of the carboxylic acid residues of the tetracarboxylic acid component and the dicarboxylic acid component to the total mole number b of the amine residues of the diamine component a / b is 2 or less, and when reacting a monoamine component containing a linear alkyl group, the total number of moles a ′ of the carboxylic acid residue of the tetracarboxylic acid component and the diamine component and monoamine component The ratio a ′ / b ′ to the total number of moles b ′ of amine residues is preferably 2 or more.
[0086]
When the molar ratio a / b is larger than 2 or when the molar ratio a ′ / b ′ is smaller than 2, a dicarboxylic acid component or a monoamine component is obtained after dehydrating and ring-closing imidizing the polyimide precursor. This reaction becomes insufficient, and when used as a liquid crystal aligning agent, the characteristics of the liquid crystal cell may be adversely affected. These tetracarboxylic acid component, diamine component, dicarboxylic acid component, and monoamine component are generally reacted in an organic polar solvent such as N-methylpyrrolidone, N, N-dimethylacetamide, and N, N-dimethylformamide. is there.
[0087]
The reaction temperature when these are reacted to form a polyimide precursor can be selected from any temperature of -20 to 150 ° C, preferably -5 to 100 ° C.
[0088]
Furthermore, this polyimide precursor can be dehydrated by heating at 100 to 400 ° C., or can be made into a polyimide by chemical imidization using a commonly used imidation catalyst such as triethylamine / acetic anhydride. .
[0089]
(Polyamide type)
On the other hand, as the polyamide used in this embodiment, for example, those disclosed in JP-A-9-230354 can be used.
[0090]
Specifically, the repeating unit is represented by the following general formula (14)
[0091]
[Chemical formula 5]

[0092]
(In the formula (14), A is a divalent organic group constituting a dicarboxylic acid, and X is the following general formula (15).
[0093]
[Chemical 6]

[0094]
Or the following general formula (16)
[0095]
[Chemical 7]

[0096]
In the above formula (15) or (16), Y¹Is an oxygen atom or -CH₂A divalent organic group represented by O—, —C (═O) O— or —OC (═O) —, R¹Is an alkyl group having 8 to 22 carbon atoms or a fluorine-containing alkyl group, Y²Is-(CH₂)_n -, -O (CH₂)_n -, -CH₂O (CH₂)_n-, -C (= O) O (CH₂)_n -Or-OC (= O) (CH₂)_n A divalent organic group represented by-(n is an integer of 2 to 6), R²~ R⁶May be the same or different and each is an alkyl group having 1 to 6 carbon atoms, and m is an integer of 1 or more. And a polyamide having a weight average molecular weight of 1000 or more.
[0097]
R in the general formula (15)¹Examples of the alkyl group represented by octyl group, nonyl group, undecyl group, decyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, octadecyl group, eicosanyl group, docosanyl group, etc. Chain alkyl group, 1-ethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 1-methylheptyl group, 2-methylheptyl group, 3-methylheptyl group, 1-methyloctyl group, 2-methyloctyl group, 2-ethyloctyl group, 1-methyldecyl group, 2-methyldecyl group, 3-methyldecyl group, 1-methyldodecyl group, 1-methyltetradecyl group, 1-methylhexadecyl group, 1-methyloctadecyl group, 1-methyl Branched alkyl groups such as eicosanyl group and 2-ethyleicosanyl group It can Shimesuru.
[0098]
Also R¹Examples of the fluorine-containing alkyl group represented by formula (1) include those in which one or more hydrogen atoms of the alkyl group are substituted with fluorine atoms. Particularly preferred are perfluorooctyl group, perfluorononyl group, perfluoroundecyl. Group, perfluorodecyl group, perfluorododecyl group, perfluorotridecyl group, perfluorotetradecyl group, perfluoropentadecyl group, perfluorohexadecyl group, perfluoroheptadecyl group, perfluorooctadecyl group, perfluoroeicosanyl group, perfluorodocosanyl group, 1H, 1H-pentadecafluorooctyl group, 1H, 1H-heptadecafluorononyl group, 1H, 1H-nonadecafluorodecyl group, 1H, 1H-henicosafluoroundecyl group, 1H, 1H-tricosafluoride Decyl group, 1H, 1H-pentacosafluorotridecyl group, 1H, 1H, 2H, 2H-tridecafluorooctyl group, 1H, 1H, 2H, 2H-heptadecafluorodecyl group, 1H, 1H, 2H, 2H- Examples include henicosafluorododecyl group and 1H, 1H, 2H, 2H-pentacosafluorotetradecyl group. In addition, said alkyl group and fluorine-containing alkyl group may differ arbitrarily for every repeating unit.
[0099]
In the general formula (16), R²~ R⁶Examples of the alkyl group represented by the formula include linear or branched lower alkyl groups such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, and hexyl group. It is done. However, in order to make use of the ease of synthesis and the properties as the liquid crystal alignment film of the present invention, the methyl group is most preferable among the above substituents.
[0100]
(Polysiloxane)
The material used for the binder of this embodiment is a material whose wettability is changed by the photocatalyst in the photocatalyst-containing alignment film by exposure and is deteriorated by the action of the photocatalyst in consideration of the surface treatment by the photocatalyst as described later. Those having a main chain that is difficult to decompose are preferred. From this point, organopolysiloxane can be mentioned as a preferable material. In this embodiment, the organopolysiloxane is preferably an organopolysiloxane containing a fluoroalkyl group.
[0101]
Examples of such organopolysiloxanes include organopolysiloxanes that exhibit high strength by hydrolyzing and polycondensing chloro or alkoxysilane by sol-gel reaction or the like.
[0102]
In the above case, the general formula:
Y_nSiX_(4-n)
(Here, Y represents an alkyl group, a fluoroalkyl group, a vinyl group, an amino group, a phenyl group or an epoxy group, X represents an alkoxyl group, an acetyl group or a halogen. N is an integer from 0 to 3. )
It is preferable that it is the organopolysiloxane which is a 1 type, or 2 or more types of hydrolysis condensate or cohydrolysis condensate of the silicon compound shown by these. Here, the number of carbon atoms of the group represented by Y is preferably in the range of 1 to 20, and the alkoxy group represented by X is a methoxy group, an ethoxy group, a propoxy group, or a butoxy group. preferable.
[0103]
In particular, an organopolysiloxane containing a fluoroalkyl group as shown below as a side chain can be preferably used. Specifically, one or more hydrolysis condensates of the following fluoroalkylsilanes, Cohydrolyzed condensates can be mentioned.
[0104]
CF₃(CF₂)₃CH₂CH₂Si (OCH₃)₃;
CF₃(CF₂)₅CH₂CH₂Si (OCH₃)₃;
CF₃(CF₂)₇CH₂CH₂Si (OCH₃)₃;
CF₃(CF₂)₉CH₂CH₂Si (OCH₃)₃;
(CF₃)₂CF (CF₂)₄CH₂CH₂Si (OCH₃)₃;
(CF₃)₂CF (CF₂)₆CH₂CH₂Si (OCH₃)₃;
(CF₃)₂CF (CF₂)₈CH₂CH₂Si (OCH₃)₃;
CF₃(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₃(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₅(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₇(C₆H₄) C₂H₄Si (OCH₃)₃;
CF₃(CF₂)₃CH₂CH₂SiCH₃(OCH₃)₂;
CF₃(CF₂)₅CH₂CH₂SiCH₃(OCH₃)₂;
CF₃(CF₂)₇CH₂CH₂SiCH₃(OCH₃)₂;
CF₃(CF₂)₉CH₂CH₂SiCH₃(OCH₃)₂;
(CF₃)₂CF (CF₂)₄CH₂CH₂SiCH₃(OCH₃)₂;
(CF₃)₂CF (CF₂)₆CH₂CH₂Si CH₃(OCH₃)₂;
(CF₃)₂CF (CF₂)₈CH₂CH₂Si CH₃(OCH₃)₂;
CF₃(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₃(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₅(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₇(C₆H₄) C₂H₄SiCH₃(OCH₃)₂;
CF₃(CF₂)₃CH₂CH₂Si (OCH₂CH₃)₃;
CF₃(CF₂)₅CH₂CH₂Si (OCH₂CH₃)₃;
CF₃(CF₂)₇CH₂CH₂Si (OCH₂CH₃)₃;
CF₃(CF₂)₉CH₂CH₂Si (OCH₂CH₃)₃;and
CF₃(CF₂)₇SO₂N (C₂H₅) C₂H₄CH₂Si (OCH₃)₃.
[0105]
By using a polysiloxane containing a fluoroalkyl group as a side chain as described above as an alignment layer, the water repellency of the unexposed part of the wettability changing layer is greatly improved and side chains are formed. The orientation characteristics can be improved.
[0106]
(A-2) Second aspect
As the binder used in the second embodiment, that is, a binder that does not particularly require a function of changing the wettability on the photocatalyst-containing alignment film by the action of the photocatalyst, a high bond such that the main skeleton of the binder is not decomposed by photoexcitation of the photocatalyst If it has energy, it will not specifically limit. For example, an amorphous silica precursor can be used. This amorphous silica precursor has the general formula SiX₄X is preferably a silicon compound such as halogen, methoxy group, ethoxy group, or acetyl group, silanol as a hydrolyzate thereof, or polysiloxane having an average molecular weight of 3000 or less. Specific examples include tetraethoxysilane, tetraisopropoxysilane, tetra-n-propoxysilane, tetrabutoxysilane, and tetramethoxysilane. In this case, the amorphous silica precursor and the photocatalyst particles are uniformly dispersed in a non-aqueous solvent, hydrolyzed with moisture in the air on the substrate to form silanol, and then at room temperature. A photocatalyst-containing alignment film can be formed by dehydration condensation polymerization. If dehydration condensation polymerization of silanol is carried out at 100 ° C. or higher, the degree of polymerization of silanol increases and the strength of the film surface can be improved. Moreover, these binders can be used individually or in mixture of 2 or more types.
[0107]
When such a binder is used, a decomposed substance capable of changing the wettability on the photocatalyst-containing alignment film can be changed in the photocatalyst-containing alignment film by being decomposed by the action of a photocatalyst by energy irradiation described later as an additive. It is essential to contain it.
[0108]
(Degradable substance)
In the second and third aspects, the photocatalyst-containing alignment film needs to contain a decomposition substance that can be decomposed by the action of the photocatalyst by energy irradiation and thereby change the wettability on the photocatalyst-containing alignment film. There is. That is, when the binder itself does not have a function of changing the wettability on the photocatalyst-containing alignment film, and when such a function is insufficient, the above-described photocatalyst-containing alignment film is added by adding a decomposition substance as described above. It causes a change in the wettability above, or assists with such a change.
[0109]
Examples of such a decomposing substance include a surfactant having a function of decomposing by the action of a photocatalyst and changing the wettability of the photocatalyst-containing alignment film surface by being decomposed. Specifically, hydrocarbons such as NIKKOL BL, BC, BO, BB series manufactured by Nikko Chemicals Co., Ltd., ZONYL FSN, FSO manufactured by DuPont, Surflon S-141, 145 manufactured by Asahi Glass Co., Ltd., Dainippon Megafac F-141, 144 manufactured by Ink Chemical Industry Co., Ltd., Footgent F-200, F251 manufactured by Neos Co., Ltd., Unidyne DS-401, 402 manufactured by Daikin Industries, Ltd., Fluorard FC-170 manufactured by 3M Co., Ltd. Fluorine-based or silicone-based nonionic surfactants such as 176 can be used, and cationic surfactants, anionic surfactants, and amphoteric surfactants can also be used.
[0110]
Besides surfactants, polyvinyl alcohol, unsaturated polyester, acrylic resin, polyethylene, diallyl phthalate, ethylene propylene diene monomer, epoxy resin, phenol resin, polyurethane, melamine resin, polycarbonate, polyvinyl chloride, polyamide, polyimide Styrene butadiene rubber, chloroprene rubber, polypropylene, polybutylene, polystyrene, polyvinyl acetate, polyester, polybutadiene, polybenzimidazole, polyacrylonitrile, epichlorohydrin, polysulfide, polyisoprene, oligomers, polymers, and the like can be contained.
[0111]
b. photocatalyst
Next, the photocatalyst used in this embodiment will be described. As a photocatalyst used in this embodiment, for example, titanium dioxide (TiO 2) known as an optical semiconductor.₂), Zinc oxide (ZnO), tin oxide (SnO)₂), Strontium titanate (SrTiO)₃), Tungsten oxide (WO₃), Bismuth oxide (Bi₂O₃), And iron oxide (Fe₂O₃1) or a mixture of two or more selected from these.
[0112]
In this embodiment, titanium dioxide is particularly preferably used because it has a high band gap energy, is chemically stable, has no toxicity, and is easily available. Titanium dioxide includes anatase type and rutile type, and both can be used in this embodiment, but anatase type titanium dioxide is preferable. Anatase type titanium dioxide has an excitation wavelength of 380 nm or less.
[0113]
Examples of such anatase type titanium dioxide include hydrochloric acid peptizer type anatase type titania sol (STS-02 manufactured by Ishihara Sangyo Co., Ltd. (average particle size 7 nm), ST-K01 manufactured by Ishihara Sangyo Co., Ltd.), nitric acid solution An anatase type titania sol (TA-15 manufactured by Nissan Chemical Co., Ltd. (average particle size 12 nm)) and the like can be mentioned.
[0114]
The smaller the particle size of the photocatalyst, the more effective the photocatalytic reaction occurs. The average particle size is preferably 50 nm or less, and it is particularly preferable to use a photocatalyst of 20 nm or less.
[0115]
The content of the photocatalyst in the photocatalyst-containing alignment film used in this embodiment can be set in the range of 5 to 60% by weight, preferably 20 to 40% by weight.
[0116]
The mechanism of action of photocatalysts typified by titanium dioxide in photocatalyst-containing alignment films is not always clear, but carriers generated by light irradiation react directly with nearby compounds or the presence of oxygen or water. It is believed that the reactive oxygen species generated below will change the chemical structure of organic matter. In this embodiment, it is considered that this carrier acts on the compound in the photocatalyst-containing alignment film.
[0117]
(3) Other
The film thickness of the photocatalyst-containing alignment film in this embodiment is preferably in the range of 0.05 to 10 μm due to the relationship of the change rate of wettability by the photocatalyst.
[0118]
In addition, the photocatalytic alignment film of this embodiment is usually disposed at a position where the alignment film is disposed in the liquid crystal display device, that is, with the liquid crystal layer interposed therebetween. In addition, the alignment film of this embodiment is usually disposed on the surface of either the color filter side or the array substrate side of the liquid crystal layer, but may be disposed on both surfaces if necessary.
[0119]
2. Second embodiment
Next, a second embodiment of the alignment film of the present invention will be described. A second embodiment of the alignment film of the present invention is characterized in that the photocatalyst alignment film is composed of a photocatalyst treatment layer containing a photocatalyst and a wettability changing alignment film formed on the photocatalyst treatment layer. is there. Each configuration of the alignment film of this embodiment will be described.
[0120]
(1) Water repellent area and hydrophilic area
The water-repellent region and the hydrophilic region in the present embodiment are the same as those described in “1. First embodiment” described above, and thus the description thereof is omitted here.
[0121]
(2) Wetting change orientation film
The wettability changing alignment film in this embodiment is not particularly limited as long as the wettability is changed by the action of the photocatalyst. However, it is preferable to form the same material as the binder in the photocatalyst-containing alignment film of the first embodiment. In addition, regarding the material of the wettability changing alignment film when formed with the same material as the binder in the photocatalyst-containing alignment film of the first embodiment as described above, it is described in “1. First embodiment” described above. Since it is the same as that of a thing, description here is abbreviate | omitted.
[0122]
The film thickness of the wettability changing alignment film of this embodiment is preferably in the range of 0.001 to 1 μm, more preferably in the range of 0.01 to 0.1 μm, depending on the relationship of the change rate of wettability by the photocatalyst. It is.
[0123]
(3) Photocatalyst treatment layer
Next, the photocatalyst treatment layer will be described. In this embodiment, the photocatalyst treatment layer is particularly limited as long as the photocatalyst in the photocatalyst treatment layer is formed so as to change the wettability of the wettability alignment film formed on the photocatalyst treatment layer. However, the film may be formed of a photocatalyst alone or may be composed of a photocatalyst and a binder. The wettability of the surface may be particularly hydrophilic or water repellent.
[0124]
The photocatalyst used in the present embodiment is the same as that described in “1. First embodiment” described above, and thus the description thereof is omitted here.
[0125]
Moreover, when the photocatalyst processing layer has a binder, since it is the same as the photocatalyst-containing alignment film described in the first embodiment, description thereof is omitted here.
[0126]
The thickness of the photocatalyst treatment layer is preferably in the range of 0.05 to 10 μm.
[0127]
(4) Other
The photocatalytic alignment film of this embodiment is usually disposed at a position where the alignment film is disposed in a liquid crystal display device, that is, with a liquid crystal layer interposed therebetween. The alignment film of the present invention is usually disposed on the surface of either the color filter side or the array substrate side of the liquid crystal layer, but may be disposed on both surfaces if necessary.
[0128]
B. Alignment film manufacturing method
Next, a method for producing an alignment film included in the present invention will be described. The method for producing an alignment film of the present invention has two embodiments. Hereinafter, a method for manufacturing each alignment film will be described.
[0129]
1. Third embodiment
First, a third embodiment of the method for producing an alignment film according to the present invention will be described. A third embodiment of the present invention is a photocatalyst alignment film formation formed on a substrate, having a photocatalyst and a binder, and forming a photocatalyst alignment film comprising a photocatalyst-containing alignment film whose surface wettability is changed by the action of the photocatalyst. And irradiating the photocatalyst-containing alignment film with energy in a pattern to form a water-repellent region on the photocatalyst-containing alignment film and a hydrophilic region having a smaller contact angle with water than the water-repellent region. And a wettability pattern forming step for forming a wettability pattern.
[0130]
In the present invention, alignment of liquid crystal molecules in a pixel can be performed only by forming a wettability pattern including a water-repellent region and a water-repellent region on the alignment film. Therefore, when the liquid crystal display device is an MVA mode liquid crystal display device, it is possible to divide the alignment direction of the liquid crystal molecules in the pixel more easily than a method such as forming a structure such as a protrusion. it can.
[0131]
(1) Photocatalyst alignment film forming step
In the photocatalyst alignment film forming step of the present embodiment, first, a photocatalyst alignment film is formed on a substrate, which has a binder and a photocatalyst, and is formed of a photocatalyst-containing alignment film whose surface wettability is changed by the action of the photocatalyst. A film forming step is performed.
[0132]
a. substrate
In this embodiment, as shown in FIG. 12, the photocatalyst alignment film substrate 3 has at least a substrate 1 and a photocatalyst-containing alignment film 2 formed on the substrate 1.
[0133]
As a board | substrate used for this embodiment, if it is a transparent material, even if it has flexibility, such as a resin-made film, it may not have flexibility, such as glass.
[0134]
In general, various functional layers such as a transparent electrode layer are formed on such a substrate, and a photocatalyst-containing alignment film is formed thereon.
[0135]
b. Photocatalyst-containing alignment film
The photocatalyst-containing alignment film used in this embodiment has a binder and a photocatalyst, and the wettability changes by the action of the photocatalyst.
[0136]
Since the binder and the photocatalyst constituting the photocatalyst-containing alignment film of this embodiment are the same as those described in the above-mentioned “A. alignment film”, description thereof is omitted here.
[0137]
When polysiloxane is used as a binder, the photocatalyst-containing alignment film is prepared by dispersing a photocatalyst and a polysiloxane as a binder in a solvent together with other additives as necessary. Can be formed by coating on the substrate. As the solvent to be used, alcohol-based organic solvents such as ethanol and isopropanol are preferable. The coating can be performed by a known coating method such as spin coating, spray coating, dip coating, roll coating or bead coating. When an ultraviolet curable component is contained as a binder, a photocatalyst-containing alignment film can be formed by performing a curing treatment by irradiating ultraviolet rays.
[0138]
(2) Wetting pattern formation process
In this embodiment, the photocatalyst-containing alignment film is irradiated with energy in a pattern so that the water-repellent region on the photocatalyst-containing alignment film and the hydrophilicity that is a region having a smaller contact angle with water than the water-repellent region A wettability pattern forming step for forming a wettability pattern composed of regions is performed.
[0139]
The energy irradiation (exposure) referred to in the present embodiment is a concept including irradiation of any energy ray capable of changing the wettability of the photocatalyst-containing alignment film surface by a photocatalyst, and is limited to irradiation with visible light. It is not a thing.
[0140]
Usually, the wavelength of light used for such exposure is set in the range of 400 nm or less, preferably in the range of 380 nm or less. This is because, as described above, the preferred photocatalyst used in the photocatalyst-containing alignment film is titanium dioxide, and light having the above-described wavelength is preferable as energy for activating the photocatalytic action by the titanium dioxide.
[0141]
Examples of light sources that can be used for such exposure include mercury lamps, metal halide lamps, xenon lamps, excimer lamps, and various other light sources.
[0142]
In addition to the above-described method using pattern energy irradiation through a photomask using a light source as described above, it is also possible to use a method of drawing and irradiating in a pattern using a laser such as excimer or YAG.
[0143]
Further, the amount of energy irradiation upon exposure is set to an amount necessary for the photocatalyst-containing alignment film surface to change the wettability of the photocatalyst-containing alignment film surface by the action of the photocatalyst in the photocatalyst-containing alignment film.
[0144]
In this case, it is preferable in that the photocatalyst-containing alignment film is exposed while being heated, so that sensitivity can be increased and efficient wettability can be changed. Specifically, it is preferable to heat within a range of 30 ° C to 80 ° C.
[0145]
As the exposure direction in this embodiment, pattern energy irradiation or laser drawing irradiation through a photomask may be performed from any direction on the substrate side and the photocatalyst-containing alignment film side.
[0146]
(3) Other
Other points in the present embodiment, such as the water-repellent region and the hydrophilic region, are the same as those described in the section “A. Alignment film”, and thus the description thereof is omitted here.
[0147]
2. Fourth embodiment
Next, a fourth embodiment of the method for producing an alignment film of the present invention will be described. The fourth embodiment of the present invention comprises a photocatalyst treatment layer that is formed on a substrate and contains a photocatalyst, and a wettability changing alignment film that is formed on the photocatalyst treatment layer and changes the wettability of the surface by the photocatalyst. A photocatalyst alignment film forming step for forming a photocatalyst alignment film, and irradiating the wettability changing alignment film with energy in a pattern form, thereby forming a water repellent region on the wettability changing alignment film and water from the water repellent region. And a wettability pattern forming step of forming a wettability pattern including a hydrophilic region that is a region having a small contact angle.
[0148]
In this embodiment, alignment division of liquid crystal molecules in a pixel can be performed only by forming a wettability pattern including a water-repellent region and a water-repellent region on the alignment film. Accordingly, it is possible to divide the alignment direction of the liquid crystal molecules in the pixel more easily than a method of forming a structure such as a protrusion.
[0149]
(1) Photocatalyst alignment film forming step
In the photocatalyst alignment film forming step of this embodiment, first, a photocatalyst treatment layer that is formed on a substrate and contains a photocatalyst, and a wettability change orientation that is formed on the photocatalyst treatment layer and the surface wettability is changed by the photocatalyst. A photocatalyst alignment film forming step of forming a photocatalyst alignment film comprising the film is performed.
[0150]
a. substrate
In this embodiment, as shown in FIG. 13, the photocatalyst alignment film substrate 3 includes at least the substrate 1, the photocatalyst treatment layer 4 formed on the substrate 1, and the wetting formed on the photocatalyst treatment layer. The property change alignment film 5 is included.
[0151]
As in the third embodiment, the substrate used in this embodiment has a flexibility such as glass even if it is a transparent material as long as it is a transparent material. It may not be.
[0152]
In general, various functional layers such as a transparent electrode layer are formed on such a substrate, and a photocatalytic alignment film is formed thereon.
[0153]
b. Photocatalyst treatment layer
The photocatalyst treatment layer used in this embodiment is particularly suitable if the photocatalyst in the photocatalyst treatment layer is formed so as to change the wettability of the wettability changing alignment film formed on the photocatalyst treatment layer. It is not limited, The thing comprised from the photocatalyst and the binder may be sufficient, and it may be formed into a film by the photocatalyst single-piece | unit. The wettability of the surface may be particularly hydrophilic or water repellent.
[0154]
In this embodiment, for example, as shown in FIG. 13, a photocatalyst processing layer 4 is formed on the entire surface of the substrate 1, and a wettability changing alignment film 5 is formed on the photocatalyst processing layer. For example, as shown in FIG. 14, the photocatalyst processing layer 4 is formed in a pattern on the substrate 1, and the wettability changing alignment film 5 is formed on the photocatalyst processing layer. There may be.
[0155]
By forming the photocatalyst processing layer in a pattern like this, pattern irradiation using a photomask or the like is performed when irradiating energy to the wettability changing alignment film as described in the wettability pattern forming step described later. The wettability pattern which consists of a hydrophilic region and a water-repellent region can be formed on the wettability changing alignment film by irradiating the entire surface.
[0156]
The patterning method of the photocatalyst processing layer is not particularly limited, but can be performed by, for example, a photolithography method.
[0157]
In addition, since the wettability of only the portion of the wettability changing alignment film on the photocatalyst treatment layer actually changes, the energy irradiation direction is such that the portion of the wettability change alignment film on the photocatalyst treatment layer is irradiated with energy. As long as it is applied, the irradiation may be performed from any direction, and the irradiation energy is not particularly limited to parallel light such as parallel light.
[0158]
The photocatalyst used in the present embodiment is the same as that described in “A. Alignment film” described above, and thus the description thereof is omitted here.
[0159]
Further, when the photocatalyst processing layer has a binder, it is the same as the photocatalyst-containing alignment film described in the above-mentioned “1. Third embodiment”, and therefore the description thereof is omitted here.
[0160]
Examples of a method for forming a photocatalyst treatment layer composed of only a photocatalyst include a method using a vacuum film forming method such as a sputtering method, a CVD method, or a vacuum deposition method. By forming the photocatalyst processing layer by a vacuum film forming method, a photocatalyst processing layer that is a uniform film and contains only the photocatalyst can be obtained. This makes it possible to uniformly change the wettability on the wettability-changing alignment film, and because it consists of only a photocatalyst, the wettability on the wettability-change layer is more efficient than using a binder. Can be changed.
[0161]
Examples of a method for forming a photocatalyst treatment layer composed of only a photocatalyst include a method in which amorphous titania is formed on a substrate when the photocatalyst is titanium dioxide, and then the phase is changed to crystalline titania by firing. As the amorphous titania used here, for example, hydrolysis, dehydration condensation, tetraethoxytitanium, tetraisopropoxytitanium, tetra-n-propoxytitanium, tetrabutoxytitanium, titanium inorganic salts such as titanium tetrachloride and titanium sulfate, An organic titanium compound such as tetramethoxytitanium can be obtained by hydrolysis and dehydration condensation in the presence of an acid. Next, it can be modified to anatase titania by baking at 400 ° C. to 500 ° C. and modified to rutile type titania by baking at 600 ° C. to 700 ° C.
[0162]
In the case of a photocatalyst treatment layer composed only of a photocatalyst, the efficiency with respect to the change in wettability on the wettability changing alignment film is improved, which is advantageous in terms of cost such as shortening the treatment time. On the other hand, in the case of a photocatalyst treatment layer comprising a photocatalyst and a binder, there is an advantage that the formation of the photocatalyst treatment layer is easy.
[0163]
c. Wetting change orientation film
Next, the wettability changing alignment film will be described. In this embodiment, the wettability-changing alignment film is not particularly limited as long as the wettability is changed by the action of the photocatalyst, but the photocatalyst-containing alignment film of the third embodiment is not limited thereto. It is preferable to form the same material as that of the binder. As described above, the material and the forming method of the wettability changing alignment film when formed of the same material as the binder in the photocatalyst-containing alignment film of the third embodiment are described in “1. Third embodiment” described above. Since it is the same as what was done, description here is abbreviate | omitted.
[0164]
(2) Wetting pattern formation process
Next, the wettability pattern forming process of this embodiment will be described. In this embodiment, by irradiating the wettability changing alignment film with energy in a pattern, the wettability changing alignment film is a region having a contact angle between the water repellent region and water smaller than the water repellent region. A wettability pattern forming step for forming a wettability pattern including a hydrophilic region is performed.
[0165]
When the photocatalyst processing layer is formed on the entire surface of the substrate, pattern energy irradiation or laser drawing irradiation may be performed via a photomask from either the substrate side or the wettability changing alignment film side. It is.
[0166]
On the other hand, when the photocatalyst layer is formed in a pattern on the substrate, as described above, any direction can be used as long as energy is applied to the wettability changing alignment film portion on the photocatalyst treatment layer. May be irradiated. Further, the energy to be irradiated is not particularly limited to parallel light such as parallel light.
[0167]
In the wettability pattern forming process of the present embodiment, the energy, the energy irradiation method, and the like are the same as those described in “1. Third embodiment” described above, and thus the description thereof is omitted here.
[0168]
(3) Other
Other points in the present embodiment, such as the water-repellent region and the hydrophilic region, are the same as those described in the section “A. Alignment film”, and thus the description thereof is omitted here.
[0169]
C. Substrate with alignment film
Next, the substrate with an alignment film of the present invention will be described. The substrate with an alignment film of the present invention is hydrophilic, which is a region formed on the substrate and on the surface in contact with the liquid crystal layer, on the surface where the liquid-repellent region is in contact with water. And an alignment film containing a photocatalyst and having the surface wettability changed by the action of the photocatalyst. Thus, by having an alignment film in which a hydrophilic region is formed in a pattern in the water-repellent region, for example, when used in a liquid crystal display device in a vertical alignment mode, liquid crystal molecules that are vertically aligned in the water-repellent region. By utilizing the property of tilting in the hydrophilic region, it is possible to make alignment division within the pixel of vertically aligned liquid crystal molecules.
[0170]
FIG. 15 shows an example of such a substrate with an alignment film of the present invention, and shows a state in which the alignment film 6 is formed on the substrate 1 through the transparent electrode layer 7.
[0171]
The alignment film used in the substrate with an alignment film of the present invention is the same as that described in the above section “A. Alignment film”, and thus description thereof is omitted here.
[0172]
Moreover, the board | substrate used by this invention is a transparent substrate normally, and may have flexibility, such as transparent resin, even if it does not have flexibility, such as glass.
[0173]
In the present invention, for example, as shown in FIG. 16, a liquid crystal layer 8 is usually disposed on the surface side of the alignment film.
[0174]
A transflective film is formed by aligning and curing a curable cholesteric liquid crystal (for example, a mixture of a curable nematic liquid crystal and a curable chiral agent) using the alignment film of the present invention. In addition, by using a curable nematic liquid crystal, a curable short pitch cholesteric liquid crystal, and a curable discotic liquid crystal, the birefringence is similarly adjusted by aligning and curing the alignment film of the present invention. It can be used as an optical compensation sheet.
[0175]
The liquid crystal molecules used in the liquid crystal layer are not particularly limited as long as they are negative liquid crystal materials having negative dielectric anisotropy and have a nematic phase at room temperature. Specific examples include MLC-6608, MLC-2037, MLC-2038, and MLC-2039 (each trade name) manufactured by Merck.
[0176]
The substrate with an alignment film of the present invention may be one in which another layer is formed between the substrate and the alignment film. For example, as shown in FIG. 17, the colored layer 9 and its boundary are formed on the substrate 1. The light shielding part (black matrix) 13 formed in the part may be provided, the transparent electrode layer 7 may be provided thereon, and the alignment film 6 may be formed thereon.
[0177]
Such a colored layer and a light-shielding part used in the present invention are not particularly limited as long as they are usually used in a color filter, and the colored layer is red, blue, or the like used in a usual pigment dispersion method. Alternatively, a photosensitive resin containing a green pigment is preferably used, and as the light shielding part, a resin in which particles having light shielding properties such as a metal such as chromium or carbon black are dispersed is preferably used.
[0178]
Further, the transparent electrode layer is not particularly limited, but generally ITO is preferably used.
[0179]
D. Liquid crystal display
Finally, the liquid crystal display device of the present invention will be described. The liquid crystal display device of the present invention includes a first substrate, a colored layer formed on the first substrate, a transparent electrode layer formed on the colored layer, and a liquid crystal layer formed on the transparent electrode layer. Has a wettability pattern consisting of a water-repellent region and a hydrophilic region where the contact angle between water and the water-repellent region is smaller than that of the water-repellent region. A color filter side substrate having an alignment film whose surface wettability changes by action; and
A second substrate, a transparent electrode layer formed on the second substrate, a surface formed on the surface of the transparent electrode layer, on a side in contact with the liquid crystal layer, and a water repellent region and water from the water repellent region; A counter substrate having a wettability pattern composed of a hydrophilic region, which is a region having a small contact angle, and having an alignment film containing a photocatalyst and whose surface wettability is changed by the action of the photocatalyst,
Arranged so that the alignment film on the color filter side substrate and the alignment film on the opposite substrate side face each other,
A liquid crystal is sealed between the two alignment films.
[0180]
Since such a liquid crystal display device has an alignment film in which hydrophilic regions are formed in a pattern in the water repellent region, for example, in a liquid crystal display device in a vertical alignment mode, the water repellent region is vertically aligned. By utilizing the property that the liquid crystal molecules to be tilted in the hydrophilic region, the alignment of vertically aligned liquid crystal molecules can be made possible within the pixel.
[0181]
An example of such a liquid crystal display device is shown in FIG. First, in the color filter side substrate on which the color filter is formed, a colored layer 9 having a red, green, and blue pattern is usually formed on the first substrate 41, and a transparent electrode is formed on the surface thereof. The layer 7 is formed, and the alignment film 6 as described above is formed on the surface thereof.
[0182]
On the other hand, the counter substrate facing the color filter side substrate has the transparent electrode layer 7 formed on the second substrate 42 and the alignment film 6 as described above formed on the surface thereof.
[0183]
Note that either the transparent electrode layer on the color filter side substrate or the transparent electrode layer on the counter substrate side may be an active matrix type.
[0184]
The alignment film 6 on the color filter side substrate and the alignment film 6 on the counter substrate side are arranged so as to face each other, and liquid crystal molecules 8 are sealed in these gaps to form a liquid crystal layer 8. It is considered as a display device.
[0185]
Such an alignment film used in the liquid crystal display device of the present invention is the same as that described in the above-mentioned “A. Alignment film”. The other first and second substrates are the same as those described in “B. Alignment film manufacturing method”, and the colored layer, the transparent electrode layer, and the liquid crystal layer are also described in “C. The description is omitted here because it is the same as that described in “.
[0186]
The present invention is not limited to the above embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. Are included in the technical scope.
[0187]
【Example】
Hereinafter, the present invention will be specifically described with reference to examples.
[0188]
[Example 1]
(I) Production of substrate with alignment film
(Formation of photocatalyst treatment layer)
A photocatalyst aqueous dispersion of titanium oxide ST-K01 (manufactured by Ishihara Sangyo Co., Ltd.) is applied onto the ITO electrode of the color filter by a spin coater, dried and cured at 150 ° C. for 10 minutes, and a transparent photocatalyst treatment layer Formed.
[0189]
(Formation of wettability changing alignment film)
Fluoroalkylsilane (GE Toshiba Silicone TSL8233) 5g, tetramethoxysilane 2g, 1N hydrochloric acid 2g are mixed for 8 hours, this solution is applied on the color filter on which the photocatalyst treatment layer is formed, and heated at 150 ° C for 10 minutes. Thus, a wettability changing alignment film was formed so as to cover the photocatalyst processing layer. The contact angle with water on the formed wettability changing alignment film was 112 °.
[0190]
(exposure)
Using a high-pressure mercury lamp (scattered light) on the color filter on which the wettability changing alignment film is formed, 700 mJ / cm through a mask.²Irradiated with (365 nm) energy. As a result, the wettability changed only at the site where light was transmitted, and the contact angle of water became 10 ° or less. Through the above series of operations, an alignment film-coated substrate on which a wettability pattern was formed was obtained.
[0191]
(Ii) Fabrication of liquid crystal display device
The above-mentioned substrate with an alignment film was bonded and bonded to the substrate with an alignment film obtained in the same manner. At that time, in order to make the gap between the substrates 5 μm, SP series made by Sekisui Fine Chemical was sprayed on one of the substrates with the alignment film. In order to secure the closed space where the upper and lower substrates are bonded and the liquid crystal is filled, a sealant is applied to the outer periphery, pressed, and then thermally cured.
[0192]
Into the gap between the substrates, a negative type liquid crystal material MLC6608 manufactured by Merck was injected to form a liquid crystal layer. This liquid crystal material has negative dielectric anisotropy, and has a property that the molecular long axis is perpendicular to the electric field direction when an electric field is applied. A liquid crystal display device was produced by the series of operations described above.
[0193]
When the obtained liquid crystal cell was observed with a polarizing microscope, the initial alignment was a vertical alignment. When a voltage was applied to the liquid crystal cell, it was observed that the tilt direction was determined starting from liquid crystal molecules tilted in advance in the hydrophilic region, and the directors of the liquid crystal were almost parallel. Furthermore, when a sufficient voltage was applied, horizontal alignment was obtained.
[0194]
[Example 2]
(I) Production of substrate with alignment film
(Formation of photocatalyst-containing alignment film)
ST-K03, an aqueous dispersion of titanium oxide as a photocatalyst, with 0.1 g of a solution in which 5 g of fluoroalkylsilane (GE Toshiba Silicone TSL8233), 2 g of tetramethoxysilane and 2 g of 1N hydrochloric acid are mixed for 8 hours. 50 g) was mixed, and this solution was applied onto the ITO electrode of the color filter by a spin coater, followed by drying and curing at 150 ° C. for 10 minutes to form a transparent photocatalyst-containing alignment film. The contact angle with water on the formed photocatalyst-containing alignment film was 110 °.
[0195]
(exposure)
Using a high-pressure mercury lamp (scattered light) for the color filter on which the photocatalyst-containing alignment film is formed, 600 mJ / cm through a mask.²Irradiated with (365 nm) energy. As a result, the wettability changed only at the site where light was transmitted, and the contact angle of water became 10 ° or less. Through the above series of operations, an alignment film-coated substrate on which a wettability pattern was formed was obtained.
[0196]
(Ii) Fabrication of liquid crystal display device
A liquid crystal display device was produced in the same manner as in Example 1.
[0197]
When the obtained liquid crystal cell was observed with a polarizing microscope, the initial alignment was a vertical alignment. When a voltage was applied to the liquid crystal cell, it was observed that the tilt direction was determined starting from liquid crystal molecules tilted in advance in the hydrophilic region, and the directors of the liquid crystal were almost parallel. Furthermore, when a sufficient voltage was applied, horizontal alignment was obtained.
[0198]
[Example 3]
(I) Production of substrate with alignment film
(Formation of photocatalyst-containing alignment film)
A solution in which 10 g of liquid crystal alignment film material SANEVER SE-1211 (manufactured by NISSAN CHEMICAL), whose main component is polyimide, and an aqueous dispersion ST-K01 (manufactured by Ishihara Sangyo Co., Ltd.) of photocatalyst are diluted 4-fold with IPA 10 g was mixed, and this solution was applied onto the ITO electrode of the color filter by a spin coater, followed by drying and curing at 150 ° C. for 10 minutes to form a transparent photocatalyst-containing alignment film. The contact angle with water on the formed photocatalyst-containing alignment film was 99 °.
[0199]
(exposure)
Using a high-pressure mercury lamp (scattered light) for the color filter on which the photocatalyst-containing alignment film is formed, 1200 mJ / cm through a mask.²Irradiated with (365 nm) energy. As a result, the wettability changed only at the site where light was transmitted, and the contact angle of water became 10 ° or less. Through the above series of operations, an alignment film-coated substrate on which a wettability pattern was formed was obtained.
[0200]
(Ii) Fabrication of liquid crystal display device
A liquid crystal display device was produced in the same manner as in Example 1.
[0201]
When the obtained liquid crystal cell was observed with a polarizing microscope, the initial alignment was a vertical alignment. When a voltage was applied to the liquid crystal cell, it was observed that the tilt direction was determined starting from liquid crystal molecules tilted in advance in the hydrophilic region, and the directors of the liquid crystal were almost parallel. Furthermore, when a sufficient voltage was applied, horizontal alignment was obtained.
[0202]
【The invention's effect】
According to the present invention, a hydrophilic region is formed in a pattern in a water-repellent region, and liquid crystal molecules that are aligned vertically in the water-repellent region are aligned vertically by utilizing the property of tilting in the hydrophilic region. Since alignment division within the pixel of the liquid crystal molecules is possible, by using such an alignment film, a liquid crystal display device with little viewing angle dependency can be obtained.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram for explaining a vertical alignment mode liquid crystal display device;
FIG. 2 is an explanatory diagram showing a conventional example of a vertical alignment mode liquid crystal display device in which alignment division is performed in a pixel.
FIG. 3 is a plan view showing a hydrophilic pattern used for an alignment film used in an MVA mode.
4 is a plan view showing an example in which liquid crystal molecules are arranged on the hydrophilic pattern shown in FIG. 3. FIG.
5 is a schematic cross-sectional view showing a state of the example shown in FIG. 4 as viewed from the cross-section.
FIG. 6 is a plan view showing a hydrophilic pattern used for an alignment film used in the IPS mode.
7 is a plan view showing an example in which liquid crystal molecules are arranged on the hydrophilic pattern shown in FIG.
8 is a schematic cross-sectional view showing a state of the example shown in FIG. 7 as seen from a cross-section.
FIG. 9 is a plan view showing a hydrophilic pattern used for an alignment film used in the TN mode.
10 is a plan view showing an example in which liquid crystal molecules are arranged on the hydrophilic pattern shown in FIG.
11 is a schematic cross-sectional view showing a state of the example shown in FIG. 10 viewed from a cross-section.
FIG. 12 is a schematic cross-sectional view showing an example of a substrate for a photocatalytic alignment film used in the present invention.
FIG. 13 is a schematic sectional view showing another example of the photocatalyst alignment film substrate used in the present invention.
FIG. 14 is a schematic cross-sectional view showing another example of a photocatalyst alignment film substrate used in the present invention.
FIG. 15 is a schematic cross-sectional view showing an example of a substrate with alignment film of the present invention.
FIG. 16 is a schematic cross-sectional view showing another example of the alignment film-coated substrate of the present invention.
FIG. 17 is a schematic sectional view showing another example of the alignment film-coated substrate of the present invention.
FIG. 18 is a schematic cross-sectional view showing an example of a liquid crystal display device of the present invention.
[Explanation of symbols]
1 ... Substrate
2 ... Photocatalyst-containing alignment film
4 ... Photocatalyst treatment layer
5 ... Wetting change orientation film
6 ... Alignment film
7 ... Transparent electrode layer
8 ... Liquid crystal layer
9 ... colored layer
31 ... Water-repellent area
32 ... hydrophilic region
41 ... 1st substrate (color filter side substrate)
42 ... Second substrate (counter substrate)

Claims (20)

The liquid crystal layer has a wettability pattern consisting of a water-repellent region and a hydrophilic region, which is a region having a smaller contact angle with water than the water-repellent region, on the surface that is in contact with the liquid crystal layer, contains a photocatalyst, and An alignment film comprising a photocatalyst alignment film whose surface wettability is changed by the action of a photocatalyst. The alignment film according to claim 1, wherein the photocatalyst alignment film is composed of a photocatalyst-containing alignment film having a binder and a photocatalyst. The alignment film according to claim 1, wherein the photocatalyst alignment film includes a photocatalyst processing layer having a photocatalyst and a wettability changing alignment film formed on the photocatalyst processing layer. 4. The contact angle with water in the water repellent region is larger in a range of 10 ° to 120 ° than the contact angle with water in the hydrophilic region. 5. The alignment film according to claim. 5. The alignment film according to claim 1, wherein a contact angle with water in the water-repellent region is within a range of 40 ° to 120 °. The photocatalyst-containing alignment film or the wettability changing alignment film has polyimide, polyamide, or organopolysiloxane as a main chain, and a linear alkyl group or fluorine-containing alkyl group having 4 to 22 carbon atoms as a side chain. The alignment film according to any one of claims 2 to 5, wherein the alignment film is made of a compound, and the density of the side chain in the water-repellent region is higher than the density of the side chain in the hydrophilic region. The alignment film according to claim 6, wherein in the water-repellent region, the weight of the side chain is 5% by weight or more based on the total weight. The organopolysiloxane is a polysiloxane containing a fluoroalkyl group, and further the organopolysiloxane is Y _n SiX _(4-n) (where Y is an alkyl group, a fluoroalkyl group, a vinyl group, an amino group) 1 represents a phenyl group or an epoxy group, X represents an alkoxyl group or a halogen, and n represents an integer of 0 to 3. The alignment film according to claim 6 or 7, which is an organopolysiloxane which is a decomposition condensate. The polyimide is a polyimide formed by imidizing a polyimide precursor containing a linear alkyl group by reactive polymerization of at least a tetracarboxylic acid component and a diamine component containing a linear alkyl group. The alignment film according to claim 6, wherein the alignment film is provided. A photocatalyst alignment film forming step of forming a photocatalyst alignment film comprising a photocatalyst-containing alignment film formed on a substrate, having a photocatalyst and a binder, and having wettability on the surface by the action of the photocatalyst;
By irradiating the photocatalyst-containing alignment film with energy in a pattern, wettability comprising a water-repellent region on the photocatalyst-containing alignment film and a hydrophilic region having a smaller contact angle with water than the water-repellent region. And a wettability pattern forming step of forming a pattern. A photocatalyst alignment film formed on a substrate and comprising a photocatalyst treatment layer containing a photocatalyst, and a wettability changing alignment film formed on the photocatalyst treatment layer, the wettability changing alignment film changing the surface wettability by the photocatalyst. Forming process;
By irradiating the wettability changing alignment film with energy in a pattern, the wettability changing alignment film comprises a water repellent area and a hydrophilic area having a smaller contact angle with water than the water repellent area. And a wettability pattern forming step of forming a wettability pattern. The photocatalyst-containing alignment film or the wettability changing alignment film is composed of a compound having polyimide, polyamide, or organopolysiloxane as a main chain and an alkyl group having 4 to 22 carbon atoms or a fluorine-containing alkyl group as a side chain. The method for producing an alignment film according to claim 10 or 11, wherein: The photocatalyst is composed of titanium oxide (TiO ₂ ), zinc oxide (ZnO), tin oxide (SnO ₂ ), strontium titanate (SrTiO ₃ ), tungsten oxide (WO ₃ ), bismuth oxide (Bi ₂ O ₃ ), and oxide. The method for producing an alignment film according to any one of claims 10 to 12, wherein the material is one or more substances selected from iron (Fe ₂ O ₃ ). The method for producing an alignment film according to claim 13, wherein the photocatalyst is titanium oxide (TiO ₂ ). The contact angle with water in the water repellent region is larger in the range of 10 ° to 120 ° than the contact angle with water in the hydrophilic region. The manufacturing method of the alignment film of Claim. The method for producing an alignment film according to any one of claims 10 to 15, wherein a contact angle with water in the water repellent region is within a range of 40 ° to 120 °. A wettability pattern comprising a water-repellent region and a hydrophilic region having a smaller contact angle with water than the water-repellent region is formed on the surface of the substrate, which is formed on the substrate and contacts the liquid crystal layer. And an alignment film containing a photocatalyst and having a surface wettability that changes by the action of the photocatalyst. The substrate with an alignment film according to claim 17, wherein a liquid crystal layer is disposed on a surface side of the alignment film. 19. A colored layer is formed on the surface of the substrate, a transparent electrode layer is formed on the surface of the colored layer, and the alignment film is formed on the transparent electrode layer. The substrate with an alignment film as described in 1. On the first substrate, the colored layer formed on the first substrate, the transparent electrode layer formed on the colored layer, the surface formed on the transparent electrode layer and in contact with the liquid crystal layer, It has a wettability pattern consisting of a water-repellent region and a hydrophilic region that has a smaller contact angle with water than this water-repellent region. It contains a photocatalyst and the surface wettability changes due to the action of the photocatalyst. A color filter side substrate having an alignment film, and
A second substrate, a transparent electrode layer formed on the second substrate, a surface formed on the surface of the transparent electrode layer, and a surface on which the liquid crystal layer is in contact with a water repellent region and water from the water repellent region. A counter substrate having a wettability pattern composed of a hydrophilic region, which is a region having a small contact angle, and having an alignment film containing a photocatalyst and whose surface wettability is changed by the action of the photocatalyst,
The color filter side substrate alignment film and the counter substrate side alignment film are arranged to face each other,
A liquid crystal display device comprising a liquid crystal sealed between the two alignment films.

Images