JP4094791B2 - Optical compensation sheet, elliptically polarizing plate, and liquid crystal display device - Google Patents

Description

【００２１】
【化２】

【００２２】
【化３】

【００２３】
【化４】

【００２４】
【化５】

【００２５】
【化６】

【００２６】
【化７】

【００２７】
上記式において、二価の連結基（Ｌ）は、アルキレン基、アルケニレン基、アリーレン基、−ＣＯ−、−ＮＨ−、−Ｏ−、−Ｓ−およびそれらの組み合わせからなる群より選ばれる二価の連結基であることが好ましい。二価の連結基（Ｌ）は、アルキレン基、アルケニレン基、アリーレン基、−ＣＯ−、−ＮＨ−、−Ｏ−および−Ｓ−からなる群より選ばれる二価の基を少なくとも二つ組み合わせた基であることがさらに好ましい。二価の連結基（Ｌ）は、アルキレン基、アルケニレン基、アリーレン基、−ＣＯ−および−Ｏ−からなる群より選ばれる二価の基を少なくとも二つ組み合わせた基であることが最も好ましい。アルキレン基の炭素原子数は、１乃至１２であることが好ましい。アルケニレン基の炭素原子数は、２乃至１２であることが好ましい。アリーレン基の炭素原子数は、６乃至１０であることが好ましい。アルキレン基、アルケニレン基およびアリーレン基は、置換基（例、アルキル基、ハロゲン原子、シアノ、アルコキシ基、アシルオキシ基）を有していてもよい。
二価の連結基（Ｌ）の例を以下に示す。左側が円盤状コア（Ｄ）に結合し、右側が重合性基（Ｑ）に結合する。ＡＬはアルキレン基またはアルケニレン基を意味し、ＡＲはアリーレン基を意味する。
【００２８】
Ｌ１：−ＡＬ−ＣＯ−Ｏ−ＡＬ−
Ｌ２：−ＡＬ−ＣＯ−Ｏ−ＡＬ−Ｏ−
Ｌ３：−ＡＬ−ＣＯ−Ｏ−ＡＬ−Ｏ−ＡＬ−
Ｌ４：−ＡＬ−ＣＯ−Ｏ−ＡＬ−Ｏ−ＣＯ−
Ｌ５：−ＣＯ−ＡＲ−Ｏ−ＡＬ−
Ｌ６：−ＣＯ−ＡＲ−Ｏ−ＡＬ−Ｏ−
Ｌ７：−ＣＯ−ＡＲ−Ｏ−ＡＬ−Ｏ−ＣＯ−
Ｌ８：−ＣＯ−ＮＨ−ＡＬ−
Ｌ９：−ＮＨ−ＡＬ−Ｏ−
Ｌ10：−ＮＨ−ＡＬ−Ｏ−ＣＯ−
Ｌ11：−Ｏ−ＡＬ−
Ｌ12：−Ｏ−ＡＬ−Ｏ−
Ｌ13：−Ｏ−ＡＬ−Ｏ−ＣＯ−
【００２９】
Ｌ14：−Ｏ−ＡＬ−Ｏ−ＣＯ−ＮＨ−ＡＬ−
Ｌ15：−Ｏ−ＡＬ−Ｓ−ＡＬ−
Ｌ16：−Ｏ−ＣＯ−ＡＬ−ＡＲ−Ｏ−ＡＬ−Ｏ−ＣＯ−
Ｌ17：−Ｏ−ＣＯ−ＡＲ−Ｏ−ＡＬ−ＣＯ−
Ｌ18：−Ｏ−ＣＯ−ＡＲ−Ｏ−ＡＬ−Ｏ−ＣＯ−
Ｌ19：−Ｏ−ＣＯ−ＡＲ−Ｏ−ＡＬ−Ｏ−ＡＬ−Ｏ−ＣＯ−
Ｌ20：−Ｏ−ＣＯ−ＡＲ−Ｏ−ＡＬ−Ｏ−ＡＬ−Ｏ−ＡＬ−Ｏ−ＣＯ−
Ｌ21：−Ｓ−ＡＬ−
Ｌ22：−Ｓ−ＡＬ−Ｏ−
Ｌ23：−Ｓ−ＡＬ−Ｏ−ＣＯ−
Ｌ24：−Ｓ−ＡＬ−Ｓ−ＡＬ−
Ｌ25：−Ｓ−ＡＲ−ＡＬ−
【００３０】
式（Ｉ）の重合性基（Ｑ）は、重合反応の種類に応じて決定する。重合性基（Ｑ）の例を以下に示す。
【００３１】
【化８】

【００３２】
重合性基（Ｑ）は、不飽和重合性基（Ｑ１〜Ｑ７）、エポキシ基（Ｑ８）またはアジリジニル基（Ｑ９）であることが好ましく、不飽和重合性基であることがさらに好ましく、エチレン性不飽和重合性基（Ｑ１〜Ｑ６）であることが最も好ましい。
式（Ｉ）において、ｎは４乃至１２の整数である。具体的な数字は、ディスコティックコア（Ｄ）の種類に応じて決定される。なお、複数のＬとＱの組み合わせは、異なっていてもよいが、同一であることが好ましい。
【００３３】
二種類以上のディスコティック液晶性分子を併用してもよい。例えば、以上述べたような重合性ディスコティック液晶性分子と非重合性ディスコティック液晶性分子とを併用することができる。
非重合性ディスコティック液晶性分子は、前述した重合性ディスコティック液晶性分子の重合性基（Ｑ）を、水素原子またはアルキル基に変更した化合物であることが好ましい。すなわち、非重合性ディスコティック液晶性分子は、下記式（Ｉａ）で表わされる化合物であることが好ましい。
（Ｉａ）Ｄ（−Ｌ−Ｒ）_n
式中、Ｄは円盤状コアであり；Ｌは二価の連結基であり；Ｒは水素原子またはアルキル基であり；そして、ｎは４乃至１２の整数である。
式（Ｉａ）の円盤状コア（Ｄ）の例は、ＬＱ（またはＱＬ）をＬＲ（またはＲＬ）に変更する以外は、前記の重合性ディスコティック液晶分子の例と同様である。
また、二価の連結基（Ｌ）の例も、前記の重合性ディスコティック液晶分子の例と同様である。
Ｒのアルキル基は、炭素原子数が１乃至４０であることが好ましく、１乃至３０であることがさらに好ましい。環状アルキル基よりも鎖状アルキル基の方が好ましく、分岐を有する鎖状アルキル基よりも直鎖状アルキル基の方が好ましい。Ｒは、水素原子または炭素原子数が１乃至３０の直鎖状アルキル基であることが特に好ましい。
【００３４】
ディスコティック液晶性分子の円盤面と透明支持体面との平均傾斜角が５°未満の状態でディスコティック液晶性分子を配向させるためには、ディスコティック液晶性分子と相分離できる化合物を一定の範囲の量で使用することが好ましい。
【００３５】
ディスコティック液晶性分子と相分離できる化合物には、含フッ素界面活性剤および１，３，５−トリアジン環を有する化合物が含まれる。
【００３６】
含フッ素界面活性剤は、フッ素原子を含む疎水性基、ノニオン性、アニオン性、カチオン性あるいは両性の親水性基および任意に設けられる連結基からなる。一つの疎水性基と一つの親水性基からなる含フッ素界面活性剤は、下記式（II）で表わされる。
【００３７】
（II） Ｒｆ−Ｌ³ −Ｈｙ
式中、Ｒｆは、フッ素原子で置換された一価の炭化水素残基であり；Ｌ³ は、単結合または二価の連結基であり；そして、Ｈｙは親水性基である。
式（II）のＲｆは、疎水性基として機能する。炭化水素残基は、アルキル基またはアリール基であることが好ましい。アルキル基の炭素原子数は３乃至３０であることが好ましく、アリール基の炭素原子数は６乃至３０であることが好ましい。
炭化水素残基に含まれる水素原子の一部または全部は、フッ素原子で置換されている。フッ素原子で、炭化水素残基に含まれる水素原子の５０％以上を置換することが好ましく、６０％以上を置換することがより好ましく、７０％以上を置換することがさらに好ましく、８０％以上を置換することが最も好ましい。
残りの水素原子は、さらに他のハロゲン原子（例、塩素原子、臭素原子）で置換されていてもよい。
Ｒｆの例を以下に示す。
【００３８】
Ｒｆ１：ｎ−Ｃ₈ Ｆ₁₇−
Ｒｆ２：ｎ−Ｃ₆ Ｆ₁₃−
Ｒｆ３：Ｃｌ−（ＣＦ₂ −ＣＦＣｌ）₃ −ＣＦ₂ −
Ｒｆ４：Ｈ−（ＣＦ₂ ）₈ −
Ｒｆ５：Ｈ−（ＣＦ₂ ）₁₀−
Ｒｆ６：ｎ−Ｃ₉ Ｆ₁₉−
Ｒｆ７：ペンタフルオロフェニル
Ｒｆ８：ｎ−Ｃ₇ Ｆ₁₅−
Ｒｆ９：Ｃｌ−（ＣＦ₂ −ＣＦＣｌ）₂ −ＣＦ₂ −
Ｒｆ10：Ｈ−（ＣＦ₂ ）₄ −
Ｒｆ11：Ｈ−（ＣＦ₂ ）₆ −
Ｒｆ12：Ｃｌ−（ＣＦ₂ ）₆ −
Ｒｆ13：Ｃ₃ Ｆ₇ −
【００３９】
式（II）において、二価の連結基は、アルキレン基、アリーレン基、二価のヘテロ環残基、−ＣＯ−、−ＮＲ−（Ｒは炭素原子数が１乃至５のアルキル基または水素原子）、−Ｏ−、−ＳＯ₂ −およびそれらの組み合わせからなる群より選ばれる二価の連結基であることが好ましい。
式（II）のＬ³ の例を以下に示す。左側が疎水性基（Ｒｆ）に結合し、右側が親水性基（Ｈｙ）に結合する。ＡＬはアルキレン基、ＡＲはアリーレン基、Ｈｃは二価のヘテロ環残基を意味する。なお、アルキレン基、アリーレン基および二価のヘテロ環残基は、置換基（例、アルキル基）を有していてもよい。
【００４０】
Ｌ０：単結合
Ｌ31：−ＳＯ₂ −ＮＲ−
Ｌ32：−ＡＬ−Ｏ−
Ｌ33：−ＣＯ−ＮＲ−
Ｌ34：−ＡＲ−Ｏ−
Ｌ35：−ＳＯ₂ −ＮＲ−ＡＬ−ＣＯ−Ｏ−
Ｌ36：−ＣＯ−Ｏ−
Ｌ37：−ＳＯ₂ −ＮＲ−ＡＬ−Ｏ−
Ｌ38：−ＳＯ₂ −ＮＲ−ＡＬ−
Ｌ39：−ＣＯ−ＮＲ−ＡＬ−
Ｌ40：−ＡＬ¹ −Ｏ−ＡＬ² −
Ｌ41：−Ｈｃ−ＡＬ−
Ｌ42：−ＳＯ₂ −ＮＲ−ＡＬ¹ −Ｏ−ＡＬ² −
Ｌ43：−ＡＲ−
Ｌ44：−Ｏ−ＡＲ−ＳＯ₂ −ＮＲ−ＡＬ−
Ｌ45：−Ｏ−ＡＲ−ＳＯ₂ −ＮＲ−
Ｌ46：−Ｏ−ＡＲ−Ｏ−
【００４１】
式（II）のＨｙは、ノニオン性親水性基、アニオン性親水性基、カチオン性親水性基あるいはそれらの組み合わせ（両性親水性基）のいずれかである。ノニオン性親水性基が特に好ましい。
式（II）のＨｙの例を以下に示す。
【００４２】

【００４３】
ノニオン性親水性基（Ｈｙ１、Ｈｙ２、Ｈｙ３）が好ましく、ポリエチレンオキサイドからなる親水性基（Ｈｙ１）が最も好ましい。
式（II）で表わされる含フッ素界面活性剤の具体例を、以上のＲｆ、Ｌ³ およびＨｙの例を引用して示す。
【００４４】
ＦＳ−１：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝６）
ＦＳ−２：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝11）
ＦＳ−３：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝16）
ＦＳ−４：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝21）
ＦＳ−５：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₂ Ｈ₅ ）−Ｈｙ１（ｎ＝６）
ＦＳ−６：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₂ Ｈ₅ ）−Ｈｙ１（ｎ＝11）
ＦＳ−７：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₂ Ｈ₅ ）−Ｈｙ１（ｎ＝16）
ＦＳ−８：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₂ Ｈ₇ ）−Ｈｙ１（ｎ＝21）
ＦＳ−９：Ｒｆ２−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝６）
ＦＳ−10：Ｒｆ２−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝11）
ＦＳ−11：Ｒｆ２−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝16）
ＦＳ−12：Ｒｆ２−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝21）
ＦＳ−13：Ｒｆ３−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝５）
ＦＳ−14：Ｒｆ３−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝10）
ＦＳ−15：Ｒｆ３−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝15）
ＦＳ−16：Ｒｆ３−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝20）
ＦＳ−17：Ｒｆ４−Ｌ33（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝７）
ＦＳ−18：Ｒｆ４−Ｌ33（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝13）
ＦＳ−19：Ｒｆ４−Ｌ33（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝19）
ＦＳ−20：Ｒｆ４−Ｌ33（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ１（ｎ＝25）
【００４５】
ＦＳ−21：Ｒｆ５−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝11）
ＦＳ−22：Ｒｆ５−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝15）
ＦＳ−23：Ｒｆ５−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝20）
ＦＳ−24：Ｒｆ５−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝30）
ＦＳ−25：Ｒｆ６−Ｌ34（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝11）
ＦＳ−26：Ｒｆ６−Ｌ34（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝17）
ＦＳ−27：Ｒｆ６−Ｌ34（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝23）
ＦＳ−28：Ｒｆ６−Ｌ34（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝29）
ＦＳ−29：Ｒｆ１−Ｌ35（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝20）
ＦＳ−30：Ｒｆ１−Ｌ35（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝30）
ＦＳ−31：Ｒｆ１−Ｌ35（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝40）
ＦＳ−32：Ｒｆ１−Ｌ36−Ｈｙ１（ｎ＝５）
ＦＳ−33：Ｒｆ１−Ｌ36−Ｈｙ１（ｎ＝10）
ＦＳ−34：Ｒｆ１−Ｌ36−Ｈｙ１（ｎ＝15）
ＦＳ−35：Ｒｆ１−Ｌ36−Ｈｙ１（ｎ＝20）
ＦＳ−36：Ｒｆ７−Ｌ36−Ｈｙ１（ｎ＝８）
ＦＳ−37：Ｒｆ７−Ｌ36−Ｈｙ１（ｎ＝13）
ＦＳ−38：Ｒｆ７−Ｌ36−Ｈｙ１（ｎ＝18）
ＦＳ−39：Ｒｆ７−Ｌ36−Ｈｙ１（ｎ＝25）
【００４６】
ＦＳ−40：Ｒｆ１−Ｌ０−Ｈｙ１（ｎ＝６）
ＦＳ−41：Ｒｆ１−Ｌ０−Ｈｙ１（ｎ＝11）
ＦＳ−42：Ｒｆ１−Ｌ０−Ｈｙ１（ｎ＝16）
ＦＳ−43：Ｒｆ１−Ｌ０−Ｈｙ１（ｎ＝21）
ＦＳ−44：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ２（ｎ＝７、Ｒ¹ ＝Ｃ₂ Ｈ₅ ）
ＦＳ−45：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ２（ｎ＝13、Ｒ¹ ＝Ｃ₂ Ｈ₅ ）
ＦＳ−46：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ２（ｎ＝20、Ｒ¹ ＝Ｃ₂ Ｈ₅ ）
ＦＳ−47：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ２（ｎ＝28、Ｒ¹ ＝Ｃ₂ Ｈ₅ ）
ＦＳ−48：Ｒｆ８−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝５）
ＦＳ−49：Ｒｆ８−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝10）
ＦＳ−50：Ｒｆ８−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝15）
ＦＳ−51：Ｒｆ８−Ｌ32（ＡＬ＝ＣＨ₂ ）−Ｈｙ１（ｎ＝20）
ＦＳ−52：Ｒｆ１−Ｌ37（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝CH₂CH₂）−Ｈｙ３（ｎ＝５）
ＦＳ−53：Ｒｆ１−Ｌ37（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝CH₂CH₂）−Ｈｙ３（ｎ＝７）
ＦＳ−54：Ｒｆ１−Ｌ37（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝CH₂CH₂）−Ｈｙ３（ｎ＝９）
ＦＳ−55：Ｒｆ１−Ｌ37（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝CH₂CH₂）−Ｈｙ３（ｎ＝12）
ＦＳ−56：Ｒｆ９−Ｌ０−Ｈｙ４（Ｍ＝Ｈ）
ＦＳ−57：Ｒｆ３−Ｌ０−Ｈｙ４（Ｍ＝Ｈ）
ＦＳ−58：Ｒｆ１−Ｌ38（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝ＣＨ₂ ）−Ｈｙ４（Ｍ＝Ｋ）
ＦＳ−59：Ｒｆ４−Ｌ39（Ｒ＝Ｃ₃ Ｈ₇ 、ＡＬ＝ＣＨ₂ ）−Ｈｙ４（Ｍ＝Na）
【００４７】
ＦＳ−60：Ｒｆ１−Ｌ０−Ｈｙ５（Ｍ＝Ｋ）
ＦＳ−61：Ｒｆ10−Ｌ40（ＡＬ¹ ＝CH₂ 、ＡＬ² ＝CH₂CH₂）−Ｈｙ５（Ｍ＝Na）
ＦＳ−62：Ｒｆ11−Ｌ40（ＡＬ¹ ＝CH₂ 、ＡＬ² ＝CH₂CH₂）−Ｈｙ５（Ｍ＝Na）
ＦＳ−63：Ｒｆ５−Ｌ40（ＡＬ¹ ＝CH₂ 、ＡＬ² ＝CH₂CH₂）−Ｈｙ５（Ｍ＝Na）
ＦＳ−64：Ｒｆ１−Ｌ38（Ｒ＝C₃H₇、ＡＬ＝CH₂CH₂CH₂ ）−Ｈｙ５（Ｍ＝Na)
ＦＳ−65：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ６（ｎ＝５、Ｍ＝Na）
ＦＳ−66：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ６（ｎ＝10、Ｍ＝Na）
ＦＳ−67：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ６（ｎ＝15、Ｍ＝Na）
ＦＳ−68：Ｒｆ１−Ｌ31（Ｒ＝Ｃ₃ Ｈ₇ ）−Ｈｙ６（ｎ＝20、Ｍ＝Na）
ＦＳ−69：Ｒｆ１−Ｌ38（Ｒ＝Ｃ₂ Ｈ₅ 、ＡＬ＝ＣＨ₂ ＣＨ₂ ）−Ｈｙ７
ＦＳ−70：Ｒｆ１−Ｌ38（Ｒ＝Ｈ、ＡＬ＝CH₂CH₂CH₂ ）−Ｈｙ８（Ｘ＝Ｉ）
ＦＳ−71：Ｒｆ11−Ｌ41（下記Ｈｃ、ＡＬ＝CH₂CH₂CH₂ ）−Ｈｙ６（Ｍは解離）
【００４８】
【化９】

【００４９】
ＦＳ−72：Ｒｆ１−Ｌ42(R=C₃H₇、AL¹=CH₂CH₂、AL²＝CH₂CH₂CH₂)−Ｈｙ６(M=Na)
ＦＳ−73：Ｒｆ12−Ｌ０−Ｈｙ５（Ｍ＝Na）
ＦＳ−74：Ｒｆ13−Ｌ43（ＡＲ＝o-フェニレン）−Ｈｙ６（Ｍ＝Ｋ）
ＦＳ−75：Ｒｆ13−Ｌ43（ＡＲ＝m-フェニレン）−Ｈｙ６（Ｍ＝Ｋ）
ＦＳ−76：Ｒｆ13−Ｌ43（ＡＲ＝p-フェニレン）−Ｈｙ６（Ｍ＝Ｋ）
ＦＳ−77：Ｒｆ６−Ｌ44（Ｒ＝C₂H₅、ＡＬ＝CH₂CH₂）−Ｈｙ５（Ｍ＝Ｈ）
ＦＳ−78：Ｒｆ６−Ｌ45（ＡＲ＝p-フェニレン、Ｒ＝C₂H₅）−Ｈｙ１（ｎ＝９）
ＦＳ−79：Ｒｆ６−Ｌ45（ＡＲ＝p-フェニレン、Ｒ＝C₂H₅）−Ｈｙ１（ｎ＝14）
ＦＳ−80：Ｒｆ６−Ｌ45（ＡＲ＝p-フェニレン、Ｒ＝C₂H₅）−Ｈｙ１（ｎ＝19）
ＦＳ−81：Ｒｆ６−Ｌ45（ＡＲ＝p-フェニレン、Ｒ＝C₂H₅）−Ｈｙ１（ｎ＝28）
ＦＳ−82：Ｒｆ６−Ｌ46（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝５）
ＦＳ−83：Ｒｆ６−Ｌ46（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝10）
ＦＳ−84：Ｒｆ６−Ｌ46（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝15）
ＦＳ−85：Ｒｆ６−Ｌ46（ＡＲ＝p-フェニレン）−Ｈｙ１（ｎ＝20）
【００５０】
フッ素原子を含む疎水性基または親水性基を二以上有する含フッ素界面活性剤を用いてもよい。二以上の疎水性基または親水性基を有する含フッ素界面活性剤の例を以下に示す。
【００５１】
【化１０】

【００５２】
ＦＳ−86：n1＋n2＝12、ＦＳ−87：n1＋n2＝18、ＦＳ−88：n1＋n2＝24
【００５３】
【化１１】

【００５４】
ＦＳ−89：n1＋n2＝20、ＦＳ−90：n1＋n2＝30、ＦＳ−91：n1＋n2＝40
【００５５】
【化１２】

【００５６】
ＦＳ−92：ｎ＝５、ＦＳ−93：ｎ＝10、ＦＳ−94：ｎ＝15、ＦＳ−95：ｎ＝20
【００５７】
【化１３】

【００５８】
二種類以上の含フッ素界面活性剤を併用してもよい。
界面活性剤については、様々な文献（例、堀口弘著「新界面活性剤」三共出版(1975)、M.J. Schick, Nonionic Surfactants, Marcell Dekker Inc., New York, (1967)、特開平７−１３２９３号公報）に記載がある。
含フッ素界面活性剤は、ディスコティック液晶性分子の量の２乃至３０重量％の量で使用することが好ましく、３乃至２５重量％の量で使用することがさらに好ましく、５乃至１０重量％の量で使用すること最も好ましい。
含フッ素界面活性剤の塗布量は、２５乃至１０００ｍｇ／ｍ² の範囲であることが好ましく、３０乃至５００ｍｇ／ｍ² の範囲であることがさらに好ましく、３５乃至２００ｍｇ／ｍ² の範囲であることが最も好ましい。
【００５９】
１，３，５−トリアジン環を有する化合物は、下記式(III）で表される化合物であることが好ましい。
【００６０】
【化１４】

【００６１】
式中、Ｘ¹ 、Ｘ² およびＸ³ は、それぞれ独立に、単結合、−ＮＲ−（Ｒは炭素原子数が１乃至３０のアルキル基または水素原子）、−Ｏ−または−Ｓ−であり；そして、Ｒ³¹、Ｒ³²およびＲ³³は、それぞれ独立に、アルキル基、アルケニル基、アリール基または複素環基である。
式(III）で表される化合物は、メラミン化合物であることが特に好ましい。メラミン化合物では、式(III）において、Ｘ¹ 、Ｘ² またはＸ³ が−ＮＲ−であるか、あるいは、Ｘ¹ 、Ｘ² またはＸ³ が単結合であり、かつＲ³¹、Ｒ³²およびＲ³³が窒素原子に遊離原子価をもつ複素環基である。メラミン化合物については、式（IV）を引用して、さらに詳細に説明する。
−ＮＲ−のＲは、水素原子であることが特に好ましい。
Ｒ³¹、Ｒ³²およびＲ³³は、アリール基であることが特に好ましい。
【００６２】
上記アルキル基は、環状アルキル基よりも鎖状アルキル基である方が好ましい。分岐を有する鎖状アルキル基よりも、直鎖状アルキル基の方が好ましい。アルキル基の炭素原子数は、１乃至３０であることが好ましく、２乃至３０であることがより好ましく、４乃至３０であることがさらに好ましく、６乃至３０であることが最も好ましい。アルキル基は、置換基を有していてもよい。置換基の例には、ハロゲン原子、アルコキシ基(例、メトキシ、エトキシ、エポキシエチルオキシ）およびアシルオキシ基（例、アクリロイルオキシ、メタクリロイルオキシ）が含まれる。
上記アルケニル基は、環状アルケニル基よりも鎖状アルケニル基である方が好ましい。分岐を有する鎖状アルケニル基よりも、直鎖状アルケニル基の方が好ましい。アルケニル基の炭素原子数は、２乃至３０であることが好ましく、３乃至３０であることがより好ましく、４乃至３０であることがさらに好ましく、６乃至３０であることが最も好ましい。アルケニル基は、置換基を有していてもよい。置換基の例には、ハロゲン原子、アルコキシ基(例、メトキシ、エトキシ、エポキシエチルオキシ）およびアシルオキシ基（例、アクリロイルオキシ、メタクリロイルオキシ）が含まれる。
【００６３】
上記アリール基は、フェニルまたはナフチルであることが好ましく、フェニルであることが特に好ましい。
アリール基は、置換基を有していてもよい。置換基の例には、ハロゲン原子、ヒドロキシル、シアノ、ニトロ、カルボキシル、アルキル基、アルケニル基、アリール基、アルコキシ基、アルケニルオキシ基、アリールオキシ基、アシルオキシ基、アルコキシカルボニル基、アルケニルオキシカルボニル基、アリールオキシカルボニル基、スルファモイル、アルキル置換スルファモイル基、アルケニル置換スルファモイル基、アリール置換スルファモイル基、スルホンアミド基、カルバモイル、アルキル置換カルバモイル基、アルケニル置換カルバモイル基、アリール置換カルバモイル基、アミド基、アルキルチオ基、アルケニルチオ基、アリールチオ基およびアシル基が含まれる。
上記アルキル基は、前述したアルキル基と同様の定義を有する。アルコキシ基、アシルオキシ基、アルコキシカルボニル基、アルキル置換スルファモイル基、スルホンアミド基、アルキル置換カルバモイル基、アミド基、アルキルチオ基とアシル基のアルキル部分も、前述したアルキル基と同様である。
上記アルケニル基は、前述したアルケニル基と同様の定義を有する。アルケニルオキシ基、アシルオキシ基、アルケニルオキシカルボニル基、アルケニル置換スルファモイル基、スルホンアミド基、アルケニル置換カルバモイル基、アミド基、アルケニルチオ基およびアシル基のアルケニル部分も、前述したアルケニル基と同様である。
上記アリール基の例には、フェニル、α−ナフチル、β−ナフチル、４−メトキシフェニル、３，４−ジエトキシフェニル、４−オクチルオキシフェニルおよび４−ドデシルオキシフェニルが含まれる。アリールオキシ基、アシルオキシ基、アリールオキシカルボニル基、アリール置換スルファモイル基、スルホンアミド基、アリール置換カルバモイル基、アミド基、アリールチオ基およびアシル基の部分の例は、上記アリール基の例と同様である。
【００６４】
Ｘ¹ 、Ｘ² またはＸ³ が−ＮＲ−、−Ｏ−または−Ｓ−である場合の複素環基は、芳香族性を有することが好ましい。芳香族性を有する複素環は、一般に不飽和複素環であり、好ましくは最多の二重結合を有する複素環である。複素環は、５員環、６員環または７員環であることが好ましく、５員環または６員環であることがさらに好ましく、６員環であることが最も好ましい。複素環のヘテロ原子は、Ｎ、ＳまたはＯであることが好ましく、Ｎであることが特に好ましい。芳香族性を有する複素環としては、ピリジン環（複素環基としては、２−ピリジルまたは４−ピリジル）が特に好ましい。複素環基は、置換基を有していてもよい。複素環基の置換基の例は、上記アリール部分の置換基の例と同様である。
Ｘ¹ 、Ｘ² またはＸ³ が単結合である場合の複素環基は、窒素原子に遊離原子価をもつ複素環基であることが好ましい。窒素原子に遊離原子価をもつ複素環基は、５員環、６員環または７員環であることが好ましく、５員環または６員環であることがさらに好ましく、５員環であることが最も好ましい。複素環基は、複数の窒素原子を有していてもよい。また、複素環基は、窒素原子以外のヘテロ原子（例、Ｏ、Ｓ）を有していてもよい。複素環基は、置換基を有していてもよい。複素環基の置換基の例は、上記アリール部分の置換基の例と同様である。以下に、窒素原子に遊離原子価をもつ複素環基の例を示す。
【００６５】
【化１５】

【００６６】
【化１６】

【００６７】
【化１７】

【００６８】
【化１８】

【００６９】
Ｒ³¹、Ｒ³²およびＲ³³の少なくとも一つは、炭素原子数が９乃至３０のアルキレン部分またはアルケニレン部分を含むことが好ましい。炭素原子数が９乃至３０のアルキレン部分またはアルケニレン部分は、直鎖状であることが好ましい。アルキレン部分またはアルケニレン部分は、アリール基の置換基に含まれていることが好ましい。
また、Ｒ³¹、Ｒ³²およびＲ³³の少なくとも一つは、重合性基を置換基として有することが好ましい。１，３，５−トリアジン環を有する化合物は、少なくとも二つの重合性基を有することが好ましい。また、重合性基は、Ｒ³¹、Ｒ³²またはＲ³³の末端に位置することが好ましい。
１，３，５−トリアジン環を有する化合物に重合性基を導入することで、１，３，５−トリアジン環を有する化合物とディスコティック液晶性分子とが重合している状態で光学異方性層に含ませることができる。
重合性基を置換基として有するＲ³¹、Ｒ³²またはＲ³³を、下記式（Ｒｐ）で示す。
【００７０】
（Ｒｐ） −Ｌ⁵ （−Ｑ）_n
式中、Ｌ⁵ は、（ｎ＋１）価の連結基であり；Ｑは、重合性基であり；そして、ｎは１乃至５の整数である。
式（ＲｐＩ）において、（ｎ＋１）価の連結基（Ｌ⁵ ）は、アルキレン基、アルケニレン基、ｎ＋１価の芳香族基、二価のヘテロ環残基、−ＣＯ−、−ＮＲ−（Ｒは炭素原子数が１乃至３０のアルキル基または水素原子）、−Ｏ−、−Ｓ−および−ＳＯ₂ −からなる群より選ばれる基を少なくとも二つ組み合わせた連結基であることが好ましい。アルキレン基の炭素原子数は、１乃至１２であることが好ましい。アルケニレン基の炭素原子数は、２乃至１２であることが好ましい。芳香族基の炭素原子数は、６乃至１０であることが好ましい。
式（Ｒｐ）のＬ⁵ の例を以下に示す。左側が式(III）のＸ¹ 、Ｘ² またはＸ³ に結合（Ｘ¹ 、Ｘ² またはＸ³ が単結合の場合は、１，３，５−トリアジン環に直結）し、右側が（Ｌ53〜Ｌ59ではｎ個の）重合性基（Ｑ）に結合する。ＡＬはアルキレン基またはアルケニレン基、Ｈｃは二価のヘテロ環残基、ＡＲは芳香族基を意味する。なお、アルキレン基、アルケニレン基、ヘテロ環残基および芳香族基は、置換基（例、アルキル基、ハロゲン原子）を有していてもよい。
【００７１】
Ｌ51：−ＡＬ−Ｏ−ＣＯ−
Ｌ52：−ＡＬ−Ｏ−
Ｌ53：−ＡＲ（−Ｏ−ＡＬ−Ｏ−ＣＯ−）_n
Ｌ54：−ＡＲ（−Ｏ−ＡＬ−Ｏ−）_n
Ｌ55：−ＡＲ（−Ｏ−ＣＯ−ＡＬ−Ｏ−ＣＯ−）_n
Ｌ56：−ＡＲ（−ＣＯ−Ｏ−ＡＬ−Ｏ−ＣＯ−）_n
Ｌ57：−ＡＲ（−Ｏ−ＣＯ−ＡＲ−Ｏ−ＡＬ−Ｏ−ＣＯ−）_n
Ｌ58：−ＡＲ（−ＮＲ−ＳＯ₂ −ＡＬ−Ｏ−ＣＯ−）_n
Ｌ59：−ＡＲ（−ＳＯ₂ −ＮＲ−ＡＬ−Ｏ−ＣＯ−）_n
【００７２】
式（Ｒｐ）における重合性基（Ｑ）の例は、ディスコティック液晶性分子の重合性基の例（Ｑ１〜Ｑ１７）と同様である。重合性基は、１，３，５−トリアジン環を有する化合物とディスコティック液晶性分子とを重合させるために使用する。よって、１，３，５−トリアジン環を有する化合物の重合性基とディスコティック液晶性分子の重合性基とは、類似の官能基であることが好ましい。従って、ディスコティック液晶性分子の重合性基と同様に、１，３，５−トリアジン環を有する化合物の重合性基（Ｑ）は、不飽和重合性基（Ｑ１〜Ｑ７）、エポキシ基（Ｑ８）またはアジリジニル基（Ｑ９）であることが好ましく、不飽和重合性基であることがさらに好ましく、エチレン性不飽和重合性基（Ｑ１〜Ｑ６）であることが最も好ましい。
ｎが複数（２乃至５）である場合、連結基（Ｌ⁵ ）はｎ＋１価の芳香族基を含み芳香族基において分岐することが好ましい。ｎは、１乃至３の整数であることが好ましい。
【００７３】
１，３，５−トリアジン環を有する化合物の（メラミン化合物を除く）具体例を以下に示す。
【００７４】
【化１９】

【００７５】
ＴＲ−１：R³¹、R³²、R³³:-(CH₂)₉-O-CO-CH=CH₂
ＴＲ−２：R³¹、R³²、R³³:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
ＴＲ−３：R³¹、R³²:-(CH₂)₉-O-CO-CH=CH₂ ;R³³:-(CH₂)₁₂-CH₃
ＴＲ−４：R³¹、R³²:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R³³:-(CH₂)₁₂-CH₃
ＴＲ−５：R³¹:-(CH₂)₉-O-CO-CH=CH₂;R³²、R³³:-(CH₂)₁₂-CH₃
ＴＲ−６：R³¹:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R³²、R³³:-(CH₂)₁₂-CH₃
ＴＲ−７：R³¹、R³²:-(CH₂)₄-O-CO-CH=CH₂ ;R³³:-(CH₂)₁₂-CH₃
ＴＲ−８：R³¹:-(CH₂)₄-O-CO-CH=CH₂ ;R³²、R³³:-(CH₂)₁₂-CH₃
ＴＲ−９：R³¹、R³²、R³³:-(CH₂)₉-O-EpEt
ＴＲ−10：R³¹、R³²、R³³:-(CH₂)₄-CH=CH-(CH₂)₄-O-EpEt
ＴＲ−11：R³¹、R³²:-(CH₂)₉-O-EpEt;R³³:-(CH₂)₁₂-CH₃
ＴＲ−12：R³¹、R³²、R³³:-(CH₂)₉-O-CH=CH₂
ＴＲ−13：R³¹、R³²:-(CH₂)₉-O-CH=CH₂;R³³:-(CH₂)₁₂-CH₃
（註）EpEt：エポキシエチル
【００７６】
【化２０】

【００７７】

【００７８】

【００７９】

【００８０】

【００８１】
１，３，５−トリアジン環を有する化合物は、下記式（IV）で表されるメラミン化合物であることが好ましい。
【００８２】
【化２１】

【００８３】
式中、Ｒ⁴¹、Ｒ⁴³およびＲ⁴⁵は、それぞれ独立に、炭素原子数が１乃至３０のアルキル基または水素原子であり、Ｒ⁴²、Ｒ⁴⁴およびＲ⁴⁶は、それぞれ独立にアルキル基、アルケニル基、アリール基または複素環基であるか、あるいは、Ｒ⁴¹とＲ⁴²、Ｒ⁴³とＲ⁴⁴またはＲ⁴⁵とＲ⁴⁶が結合して、複素環を形成する。
Ｒ⁴¹、Ｒ⁴³およびＲ⁴⁵は、炭素原子数が１乃至２０のアルキル基または水素原子であることが好ましく、炭素原子数が１乃至１０のアルキル基または水素原子であることがより好ましく、炭素原子数が１乃至６のアルキル基または水素原子であることがさらに好ましく、水素原子であることが最も好ましい。
Ｒ⁴²、Ｒ⁴⁴およびＲ⁴⁶は、アリール基であることが特に好ましい。
上記アルキル基、アルケニル基、アリール基および複素環基の定義および置換基は、前記式(III）で説明した各基の定義および置換基と同様である。
Ｒ⁴¹とＲ⁴²、Ｒ⁴³とＲ⁴⁴またはＲ⁴⁵とＲ⁴⁶が結合して形成する複素環は、前記式(III）で説明した窒素原子に遊離原子価をもつ複素環基と同様である。
【００８４】
Ｒ⁴²、Ｒ⁴⁴およびＲ⁴⁶の少なくとも一つは、炭素原子数が９乃至３０のアルキレン部分またはアルケニレン部分を含むことが好ましい。炭素原子数が９乃至３０のアルキレン部分またはアルケニレン部分は、直鎖状であることが好ましい。アルキレン部分またはアルケニレン部分は、アリール基の置換基に含まれていることが好ましい。
また、Ｒ⁴²、Ｒ⁴⁴およびＲ⁴⁶の少なくとも一つは、重合性基を置換基として有することが好ましい。メラミン化合物は、少なくとも二つの重合性基を有することが好ましい。また、重合性基は、Ｒ⁴²、Ｒ⁴⁴およびＲ⁴⁶の末端に位置することが好ましい。
メラミン化合物に重合性基を導入することで、メラミン化合物とディスコティック液晶性分子とが重合している状態で光学異方性層に含ませることができる。
重合性基を置換基として有するＲ⁴²、Ｒ⁴⁴およびＲ⁴⁶は、前述した式（Ｒｐ）で示される基と同様である。
【００８５】
メラミン化合物の具体例を以下に示す。
【００８６】
【化２２】

【００８７】
ＭＭ−１：R⁴³、R⁴⁴、R⁵³、R⁵⁴、R⁶³、R⁶⁴:-O-(CH₂)₉-CH₃
ＭＭ−２：R⁴³、R⁴⁴、R⁵³、R⁵⁴、R⁶³、R⁶⁴:-O-(CH₂)₁₁-CH₃
ＭＭ−３：R⁴³、R⁴⁴、R⁵³、R⁵⁴、R⁶³、R⁶⁴:-O-(CH₂)₁₅-CH₃
ＭＭ−４：R⁴⁴、R⁵⁴、R⁶⁴:-O-(CH₂)₉-CH₃
ＭＭ−５：R⁴⁴、R⁵⁴、R⁶⁴:-O-(CH₂)₁₅-CH₃
ＭＭ−６：R⁴³、R⁵³、R⁶³:-O-CH₃;R⁴⁴、R⁵⁴、R⁶⁴:-O-(CH₂)₁₇-CH₃
ＭＭ−７：R⁴⁴、R⁵⁴、R⁶⁴:-CO-O-(CH₂)₁₁-CH₃
ＭＭ−８：R⁴⁴、R⁵⁴、R⁶⁴:-SO₂-NH-(CH₂)₁₇-CH₃
ＭＭ−９：R⁴³、R⁵³、R⁶³:-O-CO-(CH₂)₁₅-CH₃
ＭＭ−10：R⁴²、R⁵²、R⁶²:-O-(CH₂)₁₇-CH₃
ＭＭ−11：R⁴²、R⁵²、R⁶²:-O-CH₃;R⁴³、R⁵³、R⁶³:-CO-O-(CH₂)₁₁-CH₃
ＭＭ−12：R⁴²、R⁵²、R⁶²:-Cl;R⁴³、R⁵³、R⁶³:-CO-O-(CH₂)₁₁-CH₃
ＭＭ−13：R⁴²、R⁵²、R⁶²:-O-(CH₂)₁₁-CH₃;R⁴⁵、R⁵⁵、R⁶⁵:-SO₂-NH-iso-C₃H₇
【００８８】

【００８９】

【００９０】
ＭＭ−34：R⁴⁴、R⁵⁴、R⁶⁴:-O-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−35：R⁴³、R⁴⁴、R⁵³、R⁵⁴、R⁶³、R⁶⁴:-O-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−36：R⁴⁴、R⁵⁴、R⁶⁴:-O-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
ＭＭ−37：R⁴³、R⁴⁴、R⁵³、R⁵⁴、R⁶³、R⁶⁴:-O-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
ＭＭ−38：R⁴³、R⁴⁵、R⁵³、R⁵⁵、R⁶³、R⁶⁵:-O-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−39：R⁴³、R⁴⁴、R⁴⁵、R⁵³、R⁵⁴、R⁵⁵、R⁶³、R⁶⁴、R⁶⁵:-O-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−40：R⁴⁴、R⁵⁴:-O-(CH₂)₄-O-CO-CH=CH₂;R⁶⁴:-O-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−41：R⁴⁴、R⁵⁴:-O-(CH₂)₄-O-CO-CH=CH₂;R⁶⁴:-O-(CH₂)₁₂-CH₃
ＭＭ−42：R⁴⁴、R⁵⁴:-O-(CH₂)₄-O-CO-CH=CH₂;R⁶³、R⁶⁴:-O-(CH₂)₁₂-CH₃
ＭＭ−43：R⁴⁴、R⁵⁴:-O-(CH₂)₄-O-CO-CH=CH₂;R⁶³、R⁶⁴:-O-CO-(CH₂)₁₁-CH₃
ＭＭ−44：R⁴³、R⁴⁵:-O-(CH₂)₁₂-CH₃;R⁵⁴、R⁶⁴:-O-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−45：R⁴³、R⁴⁴:-O-(CH₂)₆-O-CO-CH=CH₂;R⁵⁴、R⁶⁴:-O-(CH₂)₁₁-CH₃
ＭＭ−46：R⁴³、R⁴⁴、R⁴⁵:-O-(CH₂)₆-O-CO-CH=CH₂;R⁵⁴、R⁶⁴:-O-(CH₂)₁₁-CH₃
（註）定義のないＲ：無置換（水素原子）
p-Ph：ｐ−フェニレン
【００９１】
【化２３】

【００９２】

【００９３】
【化２４】

【００９４】

【００９５】
【化２５】

【００９６】
ＭＭ−72：R⁴¹、R⁴³、R⁴⁵:-CH₃
ＭＭ−73：R⁴¹、R⁴³、R⁴⁵:-C₂H₅
ＭＭ−74：R⁴¹、R⁴³:-C₂H₅;R⁴⁵:-CH₃
ＭＭ−75：R⁴¹、R⁴³、R⁴⁵:-(CH₂)₃-CH₃
【００９７】
【化２６】

【００９８】
ＭＭ−76：R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₉-O-CO-CH=CH₂
ＭＭ−77：R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
ＭＭ−78：R⁴²、R⁴⁴:-(CH₂)₉-O-CO-CH=CH₂ ;R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−79：R⁴²、R⁴⁴:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−80：R⁴²:-(CH₂)₉-O-CO-CH=CH₂;R⁴⁴、R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−81：R⁴²:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R⁴⁴、R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−82：R⁴²、R⁴⁴:-(CH₂)₄-O-CO-CH=CH₂ ;R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−83：R⁴²:-(CH₂)₄-O-CO-CH=CH₂ ;R⁴⁴、R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−84：R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₉-O-EpEt
ＭＭ−85：R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₄-CH=CH-(CH₂)₄-O-EpEt
ＭＭ−86：R⁴²、R⁴⁴:-(CH₂)₉-O-EpEt;R⁴⁶:-(CH₂)₁₂-CH₃
ＭＭ−87：R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₉-O-CH=CH₂
ＭＭ−88：R⁴²、R⁴⁴:-(CH₂)₉-O-CH=CH₂;R⁴⁶:-(CH₂)₁₂-CH₃
（註）EpEt：エポキシエチル
【００９９】
【化２７】

【０１００】
ＭＭ−89：R⁴¹、R⁴²、R⁴³、R⁴⁴、R⁴⁵、R⁴⁶:-(CH₂)₉-CH₃
ＭＭ−90：R⁴¹、R⁴³、R⁴⁵:-CH₃;R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₁₇-CH₃
ＭＭ−91：R⁴¹、R⁴²、R⁴³、R⁴⁴:-(CH₂)₇-CH₃;R⁴⁵、R⁴⁶:-(CH₂)₅-CH₃
ＭＭ−92：R⁴¹、R⁴²、R⁴³、R⁴⁴、R⁴⁵、R⁴⁶:-CyHx
ＭＭ−93：R⁴¹、R⁴²、R⁴³、R⁴⁴、R⁴⁵、R⁴⁶:-(CH₂)₂-O-C₂H₅
ＭＭ−94：R⁴¹、R⁴³、R⁴⁵:-CH₃;R⁴²、R⁴⁴、R⁴⁶:-(CH₂)₁₂-O-CO-CH=CH₂
ＭＭ−95：R⁴¹、R⁴²、R⁴³、R⁴⁴、R⁴⁵、R⁴⁶:-(CH₂)₈-O-CO-CH=CH₂
（註）CyHx：シクロヘキシル
【０１０１】
【化２８】

【０１０２】
メラミン化合物として、メラミンポリマーを用いてもよい。メラミンポリマーは、下記式（Ｖ）で示すメラミン化合物とカルボニル化合物との重合反応により合成することが好ましい。
【０１０３】
【化２９】

【０１０４】
式中、Ｒ⁷¹、Ｒ⁷²、Ｒ⁷³、Ｒ⁷⁴、Ｒ⁷⁵およびＲ⁷⁶は、それぞれ独立に、水素原子、アルキル基、アルケニル基、アリール基または複素環基である。
上記アルキル基、アルケニル基、アリール基および複素環基の定義および置換基は、前記式(III）で説明した各基の定義および置換基と同様である。
メラミン化合物とカルボニル化合物との重合反応は、通常のメラミン樹脂（例、メラミンホルムアルデヒド樹脂）の合成方法と同様である。市販のメラミンポリマー（メラミン樹脂）を用いてもよい。
メラミンポリマーの分子量は、２千以上４０万以下であることが好ましい。
【０１０５】
Ｒ⁷¹、Ｒ⁷²、Ｒ⁷³、Ｒ⁷⁴、Ｒ⁷⁵およびＲ⁷⁶の少なくとも一つは、炭素原子数が９乃至３０のアルキレン部分またはアルケニレン部分を含むことが好ましい。炭素原子数が９乃至３０のアルキレン部分またはアルケニレン部分は、直鎖状であることが好ましい。アルキレン部分またはアルケニレン部分は、アリール基の置換基に含まれていることが好ましい。
また、Ｒ⁷¹、Ｒ⁷²、Ｒ⁷³、Ｒ⁷⁴、Ｒ⁷⁵およびＲ⁷⁶の少なくとも一つは、重合性基を置換基として有することが好ましい。また、重合性基は、Ｒ⁷¹、Ｒ⁷²、Ｒ⁷³、Ｒ⁷⁴、Ｒ⁷⁵およびＲ⁷⁶の末端に位置することが好ましい。
メラミンポリマーに重合性基を導入することで、メラミンポリマーとディスコティック液晶性分子とが重合している状態で光学異方性層に含ませることができる。
重合性基を置換基として有するＲ⁷¹、Ｒ⁷²、Ｒ⁷³、Ｒ⁷⁴、Ｒ⁷⁵およびＲ⁷⁶は、前述した式（Ｒｐ）で示される基と同様である。
重合性基は、カルボニル化合物（Ｒ⁷¹、Ｒ⁷²）とメラミン化合物（Ｒ⁷³、Ｒ⁷⁴、Ｒ⁷⁵、Ｒ⁷⁶）の一方に導入すればよい。メラミン化合物が重合性基を有する場合は、カルボニル化合物はホルムアルデヒドのような簡単な化学構造の化合物が好ましく用いられる。カルボニル化合物が重合性基を有する場合は、メラミン化合物は、（無置換）メラミンのような簡単な化学構造の化合物が好ましく用いられる。
【０１０６】
重合性基を有するカルボニル化合物の例を以下に示す。
【０１０７】
【化３０】

【０１０８】
ＣＯ−１：R⁷²:-H;R⁸²:-O-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−２：R⁷²:-H;R⁸¹、R⁸²:-O-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−３：R⁷²:-H;R⁸²:-O-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
ＣＯ−４：R⁷²:-H;R⁸¹、R⁸²:-O-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
ＣＯ−５：R⁷²:-H;R⁸¹、R⁸³:-O-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−６：R⁷²:-H;R⁸¹、R⁸²、R⁸³:-O-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−７：R⁷²:-CH₃;R⁸²:-O-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−８：R⁷²:-(CH₂)₁₁-CH₃;R⁸²:-O-(CH₂)₄-O-CO-CH=CH₂
ＣＯ−９：R⁷²:-(CH₂)₉-O-CO-CH=CH₂;R⁸²:-O-(CH₂)₄-O-CO-CH=CH₂
ＣＯ−10：R⁷²:-(CH₂)₉-O-CO-EpEt;R⁸²:-O-(CH₂)₄-O-CO-CH=CH₂
ＣＯ−11：R⁷²:-(CH₂)₄-O-CO-CH=CH₂;R⁸¹、R⁸³:-O-(CH₂)₁₂-CH₃
（註）定義のないＲ：無置換（水素原子）
EpEt：エポキシエチル
【０１０９】
【化３１】

【０１１０】
ＣＯ−12：R⁸¹、R⁸²、R⁸³、R⁸⁴:-O-(CH₂)₆-O-CO-CH=CH₂
ＣＯ−13：R⁸²、R⁸³:-O-(CH₂)₉-O-CO-CH=CH₂
（註）定義のないＲ：無置換（水素原子）
【０１１１】
【化３２】

【０１１２】
ＣＯ−14：R⁷¹:-(CH₂)₉-O-CO-CH=CH₂;R⁷²:-H
ＣＯ−15：R⁷¹:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R⁷²:-H
ＣＯ−16：R⁷¹:-(CH₂)₉-O-CO-CH=CH₂;R⁷²:-CH₃
ＣＯ−17：R⁷¹:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R⁷²:-CH₃
ＣＯ−18：R⁷¹:-(CH₂)₉-O-CO-CH=CH₂;R⁷²:-Ph
ＣＯ−19：R⁷¹:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂;R⁷²:-Ph
ＣＯ−20：R⁷¹:-(CH₂)₄-O-CO-CH=CH₂;R⁷²:-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−21：R⁷¹:-(CH₂)₄-O-CO-CH=CH₂;R⁷²:-(CH₂)₁₂-CH₃
ＣＯ−22：R⁷¹:-(CH₂)₉-O-EpEt;R⁷²:-H
ＣＯ−23：R⁷¹:-(CH₂)₄-CH=CH-(CH₂)₄-O-EpEt;R⁷²:-H
ＣＯ−24：R⁷¹、R⁷²:-(CH₂)₉-O-EpEt
ＣＯ−25：R⁷¹、R⁷²:-(CH₂)₉-O-CO-CH=CH₂
ＣＯ−26：R⁷¹、R⁷²:-(CH₂)₄-CH=CH-(CH₂)₄-O-CO-CH=CH₂
（註）Ph：フェニル
EpEt：エポキシエチル
【０１１３】
メラミン化合物側に重合性基を有するメラミンポリマーの例を以下に示す。
【０１１４】
【化３３】

【０１１５】

【０１１６】
二種類以上の１，３，５−トリアジン環を有する化合物（メラミン化合物およびメラミンポリマーを含む）を併用してもよい。
１，３，５−トリアジン環を有する化合物は、ディスコティック液晶性分子の量の０．０１乃至２０重量％の量で使用することが好ましく、０．１乃至１５重量％の量で使用することがさらに好ましく、０．５乃至１０重量％の量で使用することが最も好ましい。
１，３，５−トリアジン環を有する化合物の塗布量は、１乃至１０００ｍｇ／ｍ² の範囲であることが好ましく、２乃至３００ｍｇ／ｍ² の範囲であることがさらに好ましく、３乃至１００ｍｇ／ｍ² の範囲であることが最も好ましい。
【０１１７】
光学異方性層は、ディスコティック液晶性分子あるいは下記の重合性開始剤や任意の添加剤（例、可塑剤、モノマー、界面活性剤、セルロースエステル、１，３，５−トリアジン化合物、カイラル剤）を含む液晶組成物（塗布液）を、配向膜の上に塗布することで形成する。
液晶組成物の調製に使用する溶媒としては、有機溶媒が好ましく用いられる。有機溶媒の例には、アミド（例、Ｎ，Ｎ−ジメチルホルムアミド）、スルホキシド（例、ジメチルスルホキシド）、ヘテロ環化合物（例、ピリジン）、炭化水素（例、ベンゼン、ヘキサン）、アルキルハライド（例、クロロホルム、ジクロロメタン）、エステル（例、酢酸メチル、酢酸ブチル）、ケトン（例、アセトン、メチルエチルケトン）、エーテル（例、テトラヒドロフラン、１，２−ジメトキシエタン）が含まれる。アルキルハライドおよびケトンが好ましい。二種類以上の有機溶媒を併用してもよい。
液晶組成物の塗布は、公知の方法（例、ワイヤーバーコーティング法、押し出しコーティング法、ダイレクトグラビアコーティング法、リバースグラビアコーティング法、ダイコーティング法）により実施できる。
【０１１８】
ディスコティック液晶性分子の重合反応には、熱重合開始剤を用いる熱重合反応と光重合開始剤を用いる光重合反応とが含まれる。光重合反応が好ましい。
光重合開始剤の例には、α−カルボニル化合物（米国特許２３６７６６１号、同２３６７６７０号の各明細書記載）、アシロインエーテル（米国特許２４４８８２８号明細書記載）、α−炭化水素置換芳香族アシロイン化合物（米国特許２７２２５１２号明細書記載）、多核キノン化合物（米国特許３０４６１２７号、同２９５１７５８号の各明細書記載）、トリアリールイミダゾールダイマーとｐ−アミノフェニルケトンとの組み合わせ（米国特許３５４９３６７号明細書記載）、アクリジンおよびフェナジン化合物（特開昭６０−１０５６６７号公報、米国特許４２３９８５０号明細書記載）およびオキサジアゾール化合物（米国特許４２１２９７０号明細書記載）が含まれる。
光重合開始剤の使用量は、塗布液の固形分の０．０１乃至２０重量％であることが好ましく、０．５乃至５重量％であることがさらに好ましい。
ディスコティック液晶性分子の重合のための光照射は、紫外線を用いることが好ましい。
照射エネルギーは、２０ｍＪ／ｃｍ² 乃至５０Ｊ／ｃｍ² であることが好ましく、１００乃至８００ｍＪ／ｃｍ² であることがさらに好ましい。光重合反応を促進するため、加熱条件下で光照射を実施してもよい。
光学異方性層の厚さは、０．１乃至２０μｍであることが好ましく、０．５乃至１５μｍであることがさらに好ましく、１乃至１０μｍであることが最も好ましい。
【０１１９】
［偏光膜］
偏光膜には、ヨウ素系偏光膜、二色性染料を用いる染料系偏光膜やポリエン系偏光膜がある。ヨウ素系偏光膜および染料系偏光膜は、一般にポリビニルアルコール系フイルムを用いて製造する。偏光膜の偏光軸は、フイルムの延伸方向に垂直な方向に相当する。
偏光膜の面内の透過軸は、透明支持体の遅相軸と、実質的に平行または直交するように配置することが好ましい。
【０１２０】
［透明保護膜］
透明保護膜としては、透明なポリマーフイルムが用いられる。保護膜が透明であるとは、光透過率が８０％以上であることを意味する。
透明保護膜としては、一般にセルロースエステルフイルム、好ましくはトリアセチルセルロースフイルムが用いられる。セルロースエステルフイルムは、ソルベントキャスト法により形成することが好ましい。
透明保護膜の厚さは、２０乃至５００μｍであることが好ましく、５０乃至２００μｍであることがさらに好ましい。
【０１２１】
［液晶表示装置］
本発明は、様々な表示モードの液晶セルに適用できる。前述したように、液晶性分子を用いた光学補償シートは、ＴＮ（Twisted Nematic）、ＩＰＳ（In-Plane Switching）、ＦＬＣ（Ferroelectric Liquid Crystal）、ＯＣＢ（Optically Compensatory Bend）、ＳＴＮ（Supper Twisted Nematic）、ＶＡ（Vertically Aligned）、ＥＣＢ（Electrically Controlled Birefringence ）およびＨＡＮ（Hybrid Aligned Nematic）モードの液晶セルに対応するものが既に提案されている。本発明は、実質的に垂直に配向している棒状液晶性分子が多いＶＡモード、ＯＣＢモード、ＨＡＮモードのような液晶セルを用いた液晶表示装置において有効であり、大部分の棒状液晶性分子が実質的に垂直に配向しているＶＡモードの液晶表示装置において特に効果がある。
ＶＡモードの液晶セルには、（１）棒状液晶性分子を電圧無印加時に実質的に垂直に配向させ、電圧印加時に実質的に水平に配向させる狭義のＶＡモードの液晶セル（特開平２−１７６６２５号公報記載）に加えて、（２）視野角拡大のため、ＶＡモードをマルチドメイン化した（ＭＶＡモードの）液晶セル（ＳＩＤ９７、Digest of tech. Papers（予稿集）２８（１９９７）８４５記載）、（３）棒状液晶性分子を電圧無印加時に実質的に垂直配向させ、電圧印加時にねじれマルチドメイン配向させるモード（ｎ−ＡＳＭモード）の液晶セル（日本液晶討論会の予稿集５８〜５９（１９９８）記載）および（４）ＳＵＲＶＡＩＶＡＬモードの液晶セル（ＬＣＤインターナショナル９８で発表）が含まれる。
【０１２２】
【実施例】
［実施例１］
（光学補償シートの作製）
セルローストリアセテートフイルムの一方の面に、セルロースジアセテートを塗布し、乾燥して、乾燥膜厚が０．５μｍの下塗り層（ラビング処理していない配向膜）を形成した。
下記のディスコティック液晶性分子（１）９０重量部、エチレンオキサイド変性トリメチロールプロパントリアクリレート（Ｖ＃３６０、大阪有機化学（株）製）１０重量部、メラミンホルムアルデヒド／アクリル酸コポリマー（アルドリッチ試薬）０．６重量部、光重合開始剤（イルガキュア９０７、日本チバガイギー（株）製）３．０重量部および光増感剤（カヤキュアーＤＥＴＸ、日本化薬（株）製）１．０重量部を、メチルエチルケトンに溶解して、固形分濃度が３８重量％の塗布液を調製した。
【０１２３】
【化３４】

【０１２４】
塗布液を下塗り層の上に塗布、乾燥した。１３０℃で２分間加熱して、ディスコティック液晶性分子を配向させた。直ちに室温に冷却し、５００ｍＪ／ｃｍ² の紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。形成した光学異方性層の厚さは、１．７μｍであった。
光学異方性層のレターデーションの角度依存性を、エリプソメーター（日本分光（株）製）で測定した。その結果、ディスコティック液晶性分子の平均傾斜角は０．２゜、厚み方向のレターデーション（Ｒth）は８８ｎｍであった。
【０１２５】
セルローストリアセテートフイルムの他方の面に、粘着剤を用いて、光学的一軸性を有するポリカーボネートフイルムを貼り合わせて光学補償シートを作製した。
光学的一軸性を有するポリカーボネートフイルムは、面内に光軸を有し、面内レターデーション（Ｒｅ）は５０ｎｍ、厚み方向のレターデーションは ｎｍであった。
作製した光学補償シート全体の面内レターデーション（Ｒｅ）は５０ｎｍ、厚み方向のレターデーション（Ｒth）は１００ｎｍであった。
【０１２６】
（楕円偏光板の作製）
光学補償シートの透明支持体（ポリカーボネートフイルム）側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１２７】
（液晶表示装置の作製）
市販のＶＡ液晶表示装置（ＬＣＤ５０００）から楕円偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＶＡ液晶表示装置について、全方位のコントラストデータを測定したところ、コントラスト比２０：１が得られる視野角は、上下左右１６０゜であった。これに対して、市販のＶＡ液晶表示装置（ＬＣＤ５０００）において、コントラスト比２０：１が得られる視野角は、上下左右１２０゜であった。
【０１２８】
［実施例２］
（光学的二軸性透明支持体の作製）
セルローストリアセテート８７重量部、トリフェニルフォスフェート１０重量部および紫外線吸収剤（ＴＭ１６５、住友化学（株）製）３重量部をメチレンクロライドに溶解して、固形分濃度が１８重量％の溶液を調製した。溶液をガラス板の上に流延し、４０℃で２０分間乾燥した。形成したフイルム（厚さ：１００μｍ）をガラス板から剥離した。
作製したセルローストリアセテートフイルムに、１４５℃で１０分間、２０Ｋｇ／ｍｍ² の応力を加えた。このようにして、面内レターデーション（Ｒｅ）が２０ｎｍ、厚み方向のレターデーション（Ｒth）が８０ｎｍである光学的二軸性透明支持体を作製した。
【０１２９】
（光学補償シートの作製）
実施例１で用いた光学異方性層の塗布液を、光学的二軸性透明支持体の上に、３ｍｌ／ｍ² 塗布し、室温で乾燥した。１３０℃で１分間加熱して、ディスコティック液晶性分子を配向させ、紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。
光学異方性層のレターデーションの角度依存性を、エリプソメーター（日本分光（株）製）で測定した。その結果、ディスコティック液晶性分子の平均傾斜角は０．１゜であった。
作製した光学補償シート全体の面内レターデーション（Ｒｅ）は２０ｎｍ、厚み方向のレターデーション（Ｒth）は１４０ｎｍであった。
【０１３０】
（楕円偏光板の作製）
光学補償シートの透明支持体側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１３１】
（液晶表示装置の作製）
市販のＶＡ液晶表示装置（ＬＣＤ５０００）から楕円偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＶＡ液晶表示装置について、全方位のコントラストデータを測定したところ、コントラスト比２０：１が得られる視野角は、上下左右１６０゜であった。
【０１３２】
［実施例３］
（光学的二軸性透明支持体の作製）
セルローストリアセテート８５重量部、トリフェニルフォスフェート１０重量部および紫外線吸収剤（ＴＭ１６５、住友化学（株）製）５重量部をメチレンクロライドに溶解して、固形分濃度が１８重量％の溶液を調製した。溶液をガラス板の上に流延し、４０℃で２０分間乾燥した。形成したフイルム（厚さ：１００μｍ）をガラス板から剥離した。
作製したセルローストリアセテートフイルムに、１４５℃で１０分間、２０Ｋｇ／ｍｍ² の応力を加えた。このようにして、面内レターデーション（Ｒｅ）が５０ｎｍ、厚み方向のレターデーション（Ｒth）が１２０ｎｍである光学的二軸性透明支持体を作製した。
【０１３３】
（光学補償シートの作製）
実施例１で用いた光学異方性層の塗布液を、光学的二軸性透明支持体の上に、６ｍｌ／ｍ² 塗布し、室温で乾燥した。１３０℃で１分間加熱して、ディスコティック液晶性分子を配向させ、紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。
光学異方性層のレターデーションの角度依存性を、エリプソメーター（日本分光（株）製）で測定した。その結果、ディスコティック液晶性分子の平均傾斜角は０．５゜であった。
作製した光学補償シート全体の面内レターデーション（Ｒｅ）は５０ｎｍ、厚み方向のレターデーション（Ｒth）は２５０ｎｍであった。
【０１３４】
（楕円偏光板の作製）
光学補償シートの透明支持体側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１３５】
（液晶表示装置の作製）
市販のＶＡ液晶表示装置（ＬＣＤ５０００）から楕円偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＶＡ液晶表示装置について、全方位のコントラストデータを測定したところ、コントラスト比２０：１が得られる視野角は、上下左右１６０゜であった。
【０１３６】
［実施例４］
（光学的二軸性透明支持体の作製）
平均酢化度６０．９％のセルロースアセテート４５重量部、下記のレターデーション上昇剤２．３５重量部、リン酸トリフェニル２．７５重量部およびリン酸ビフェニルジフェニル２．２０重量部を、塩化メチレン２３２．７５重量部、メタノール４２．５７重量部およびｎ−ブタノール８．５０重量部に溶解した。得られた溶液をドラム流延機を用いて流延し、乾燥後の厚さが１０５μｍのセルロースアセテートフイルムを作製した。
【０１３７】
【化３５】

【０１３８】
セルロースアセテートフイルムを実質延伸倍率２０％で延伸して、光学的二軸性透明支持体を作製した。
波長６３３ｎｍにおける透明支持体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、厚み方向のレターデーション（Ｒth）は８５ｎｍ、面内レターデーション（Ｒｅ）は４０ｎｍであった。
【０１３９】
（光学補償シートの作製）
透明支持体の一方の面に、ゼラチンを塗布して下塗り層を形成した。
下塗り層の上に、下記の変性ポリビニルアルコール２重量％およびグルタルアルデヒド０．１重量％の水溶液を塗布、乾燥して、厚さ０．５μｍの配向膜を形成した。
【０１４０】
【化３６】

【０１４１】
実施例１で用いたディスコティック液晶性分子（１）９０重量部、エチレンオキサイド変性トリメチロールプロパントリアクリレート（Ｖ＃３６０、大阪有機化学（株）製）１０重量部、メラミンホルムアルデヒド／アクリル酸コポリマー（アルドリッチ試薬）０．６重量部、光重合開始剤（イルガキュア９０７、日本チバガイギー（株）製）３．０重量部および光増感剤（カヤキュアーＤＥＴＸ、日本化薬（株）製）１．０重量部を、メチルエチルケトン１７０重量部に溶解して、塗布液を調製した。
塗布液を配向膜の上に塗布、乾燥した。１３０℃で１分間加熱して、ディスコティック液晶性分子を配向させた。さらに紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。形成した光学異方性層の厚さは、１．２μｍであった。
波長６３３ｎｍにおける光学補償シート全体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、面内レターデーション（Ｒｅ）は４０ｍ、厚み方向のレターデーション（Ｒth）は１６０ｎｍであった。
【０１４２】
（楕円偏光板の作製）
光学補償シートの透明支持体側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１４３】
（液晶表示装置の作製）
市販のＭＶＡ液晶表示装置（ＶＬ−１５３０Ｓ、富士通（株）製）から偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＭＶＡ液晶表示装置について、画像反転なしでコントラスト比１０：１が得られる視野角を測定した。結果は、第１表に示す。
【０１４４】
［実施例５］
（光学的二軸性透明支持体の作製）
ノルボルネン樹脂（アートン、ＪＳＲ（株）製）３０重量部を、塩化メチレン７０重量部に溶解した。得られた溶液をバンド流延機を用いて流延し、乾燥後の厚さが１００μｍのノルボルネンフイルムを作製した。
ノルボルネンフイルムを長手方向に実質延伸倍率１５％で延伸し、さらに幅方向に実質延伸倍率７％で延伸し、光学的二軸性透明支持体を作製した。
波長６３３ｎｍにおける透明支持体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、厚み方向のレターデーション（Ｒth）は４５ｎｍ、面内レターデーション（Ｒｅ）は４０ｎｍであった。
【０１４５】
（光学補償シートの作製）
透明支持体の一方の面を、コロナ放電処理した。
コロナ放電処理した面の上に、実施例４で用いた変性ポリビニルアルコール２重量％およびグルタルアルデヒド０．１重量％の水溶液を塗布、乾燥して、厚さ０．５μｍの配向膜を形成した。
実施例１で用いたディスコティック液晶性分子（１）９０重量部、エチレンオキサイド変性トリメチロールプロパントリアクリレート（Ｖ＃３６０、大阪有機化学（株）製）１０重量部、メラミンホルムアルデヒド／アクリル酸コポリマー（アルドリッチ試薬）０．６重量部、光重合開始剤（イルガキュア９０７、日本チバガイギー（株）製）３．０重量部および光増感剤（カヤキュアーＤＥＴＸ、日本化薬（株）製）１．０重量部を、メチルエチルケトン１７０重量部に溶解して、塗布液を調製した。
塗布液を配向膜の上に塗布、乾燥した。１３０℃で１分間加熱して、ディスコティック液晶性分子を配向させた。さらに紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。形成した光学異方性層の厚さは、１．４μｍであった。
波長６３３ｎｍにおける光学補償シート全体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、面内レターデーション（Ｒｅ）は３０ｍ、厚み方向のレターデーション（Ｒth）は１２０ｎｍであった。
【０１４６】
（楕円偏光板の作製）
光学補償シートの透明支持体側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１４７】
（液晶表示装置の作製）
市販のＭＶＡ液晶表示装置（ＶＬ−１５３０Ｓ、富士通（株）製）から偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＭＶＡ液晶表示装置について、画像反転なしでコントラスト比１０：１が得られる視野角を測定した。結果は、第１表に示す。
【０１４８】
［実施例６］
（光学的二軸性透明支持体の作製）
市販のポリカーボネートフイルム（帝人（株）製）を長手方向に実質延伸倍率４０％で延伸し、さらに幅方向に実質延伸倍率１５％で延伸し、光学的二軸性透明支持体を作製した。
波長６３３ｎｍにおける透明支持体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、厚み方向のレターデーション（Ｒth）は１００ｎｍ、面内レターデーション（Ｒｅ）は２００ｎｍであった。
【０１４９】
（光学補償シートの作製）
透明支持体の一方の面を、コロナ放電処理した。
コロナ放電処理した面の上に、実施例４で用いた変性ポリビニルアルコール２重量％およびグルタルアルデヒド０．１重量％の水溶液を塗布、乾燥して、厚さ０．５μｍの配向膜を形成した。
実施例１で用いたディスコティック液晶性分子（１）９０重量部、エチレンオキサイド変性トリメチロールプロパントリアクリレート（Ｖ＃３６０、大阪有機化学（株）製）１０重量部、メラミンホルムアルデヒド／アクリル酸コポリマー（アルドリッチ試薬）０．６重量部、光重合開始剤（イルガキュア９０７、日本チバガイギー（株）製）３．０重量部および光増感剤（カヤキュアーＤＥＴＸ、日本化薬（株）製）１．０重量部を、メチルエチルケトン１７０重量部に溶解して、塗布液を調製した。
塗布液を配向膜の上に塗布、乾燥した。１３０℃で１分間加熱して、ディスコティック液晶性分子を配向させた。さらに紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。形成した光学異方性層の厚さは、３．５μｍであった。
波長６３３ｎｍにおける光学補償シート全体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、面内レターデーション（Ｒｅ）は２００ｍ、厚み方向のレターデーション（Ｒth）は３００ｎｍであった。
【０１５０】
（楕円偏光板の作製）
光学補償シートの透明支持体側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１５１】
（液晶表示装置の作製）
市販のＭＶＡ液晶表示装置（ＶＬ−１５３０Ｓ、富士通（株）製）から偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＭＶＡ液晶表示装置について、画像反転なしでコントラスト比１０：１が得られる視野角を測定した。結果は、第１表に示す。
【０１５２】
［比較例１］
（光学的等方性透明支持体の作製）
市販のセルローストリアセテートフイルム（富士写真フイルム（株）製）を透明支持体として用いた。
波長６３３ｎｍにおける透明支持体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、厚み方向のレターデーション（Ｒth）は４０ｎｍ、面内レターデーション（Ｒｅ）は３ｎｍであり、実質的に光学的等方性であった。
【０１５３】
（光学補償シートの作製）
透明支持体の一方の面に、ゼラチンを塗布して下塗り層を形成した。
下塗り層の上に、実施例４で用いた変性ポリビニルアルコール２重量％およびグルタルアルデヒド０．１重量％の水溶液を塗布、乾燥して、厚さ０．５μｍの配向膜を形成した。
実施例１で用いたディスコティック液晶性分子（１）９０重量部、エチレンオキサイド変性トリメチロールプロパントリアクリレート（Ｖ＃３６０、大阪有機化学（株）製）１０重量部、メラミンホルムアルデヒド／アクリル酸コポリマー（アルドリッチ試薬）０．６重量部、光重合開始剤（イルガキュア９０７、日本チバガイギー（株）製）３．０重量部および光増感剤（カヤキュアーＤＥＴＸ、日本化薬（株）製）１．０重量部を、メチルエチルケトン１７０重量部に溶解して、塗布液を調製した。
塗布液を配向膜の上に塗布、乾燥した。１３０℃で１分間加熱して、ディスコティック液晶性分子を配向させた。さらに紫外線を照射して、ディスコティック液晶性分子を重合させ、配向状態を固定した。形成した光学異方性層の厚さは、２．０μｍであった。
波長６３３ｎｍにおける光学補償シート全体のレターデーションを、エリプソメーター（Ｍ１５０、日本分光（株）製）で測定した。その結果、面内レターデーション（Ｒｅ）は３ｍ、厚み方向のレターデーション（Ｒth）は２４０ｎｍであった。
【０１５４】
（楕円偏光板の作製）
光学補償シートの透明支持体側に、偏光膜と透明保護膜とをこの順に積層して、楕円偏光板を作製した。
透明支持体の遅相軸と偏光膜の偏光軸とは平行になるように配置した。
【０１５５】
（液晶表示装置の作製）
市販のＭＶＡ液晶表示装置（ＶＬ−１５３０Ｓ、富士通（株）製）から偏光板を削除し、代わりに作製した楕円偏光板を貼り付けた。
作製したＭＶＡ液晶表示装置について、画像反転なしでコントラスト比１０：１が得られる視野角を測定した。結果は、第１表に示す。
【０１５６】
［参考例１］
市販のＭＶＡ液晶表示装置（ＶＬ−１５３０Ｓ、富士通（株）製）について、画像反転なしでコントラスト比１０：１が得られる視野角を測定した。結果は、第１表に示す。
【０１５７】
【表１】

【図面の簡単な説明】
【図１】透過型液晶表示装置の基本的な構成を示す模式図である。
【図２】反射型液晶表示装置の基本的な構成を示す模式図である。
【符号の説明】
ＢＲ バックライト
ＲＰ 反射板
１、１ａ、１ｂ、１ｃ 透明保護膜
２、２ａ、２ｂ 偏光膜
３、３ａ、３ｂ 透明支持体
４、４ａ、４ｂ 光学異方性層
５ａ 液晶セルの下基板
５ｂ 液晶セルの上基板
６ 棒状液晶性分子[0001]
[Industrial application fields]
The present invention relates to an optical compensation sheet having an optically anisotropic layer formed from liquid crystalline molecules, an elliptically polarizing plate using the same, and a liquid crystal display device.
[0002]
[Prior art]
The liquid crystal display device includes a liquid crystal cell, a polarizing element, and an optical compensation sheet (retardation plate). In a transmissive liquid crystal display device, two polarizing elements are attached to both sides of a liquid crystal cell, and one or two optical compensation sheets are disposed between the liquid crystal cell and the polarizing element. In a reflective liquid crystal display device, a reflector, a liquid crystal cell, a single optical compensation sheet, and a single polarizing element are arranged in this order.
The liquid crystal cell is composed of a rod-like liquid crystal molecule, two substrates for enclosing it, and an electrode layer for applying a voltage to the rod-like liquid crystal molecule. The liquid crystal cell is different in the alignment state of rod-like liquid crystal molecules. As for the transmission type, TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (STN) Various display modes such as TN, HAN (Hybrid Aligned Nematic), and GH (Guest-Host) have been proposed for Supper Twisted Nematic (VA), VA (Vertically Aligned), ECB (Electrically Controlled Birefringence), and reflective type. .
[0003]
Optical compensation sheets are used in various liquid crystal display devices in order to eliminate image coloring and expand the viewing angle. As the optical compensation sheet, a stretched birefringent polymer film has been conventionally used.
It has been proposed to use an optical compensation sheet having an optically anisotropic layer formed of discotic liquid crystalline molecules on a transparent support, instead of the optical compensation sheet made of a stretched birefringent film. Since discotic liquid crystalline molecules have various alignment forms, the use of discotic liquid crystalline molecules makes it possible to realize optical properties that cannot be obtained with conventional stretched birefringent polymer films.
[0004]
The optical properties of the optical compensation sheet are determined according to the optical properties of the liquid crystal cell, specifically, the display mode differences as described above. When discotic liquid crystalline molecules are used, optical compensation sheets having various optical properties corresponding to various display modes of the liquid crystal cell can be produced.
Optical compensation sheets using discotic liquid crystalline molecules have already been proposed for various display modes. For example, an optical compensation sheet for a TN mode liquid crystal cell is described in each specification of JP-A-6-214116, US Pat. Nos. 5,583,679, 5,646,703, and German Patent 3,911,620A1. Further, an optical compensation sheet for liquid crystal cells in IPS mode or FLC mode is described in JP-A-10-54982. Furthermore, OCB mode or HAN mode liquid crystal cell optical compensation sheets are described in US Pat. No. 5,805,253 and International Patent Application WO 96/37804. Furthermore, an optical compensation sheet for an STN mode liquid crystal cell is described in JP-A-9-26572. A VA mode liquid crystal cell optical compensation sheet is described in Japanese Patent No. 2866372.
[0005]
[Problems to be solved by the invention]
By using discotic liquid crystalline molecules instead of the conventional stretched birefringent polymer film, it becomes possible to optically compensate the liquid crystal cell more accurately than in the past. For example, for a liquid crystal cell (VA mode, OCB mode, HAN mode) having a large number of rod-like liquid crystal molecules that are substantially vertically aligned, it is between the disc surface of the discotic liquid crystal molecules and the transparent support surface. When the discotic liquid crystalline molecules are aligned with an average tilt angle of less than 5 °, optical compensation can be effectively performed.
However, according to the research of the present inventor, it is very difficult to completely optically compensate the liquid crystal cell without any problem even if discotic liquid crystalline molecules are used.
An object of the present invention is to provide an optical compensation sheet capable of accurately optically compensating a liquid crystal cell having a large number of rod-like liquid crystal molecules aligned substantially vertically.
[0006]
[Means for Solving the Problems]
  The object of the present invention is the following (1) to(9)Optical compensation sheet, below(10)Ellipsoidal polarizing plate and(11)Of the liquid crystal display device.
  (1) An optical compensation sheet having an optically anisotropic layer formed from a transparent support and discotic liquid crystalline molecules,The optically anisotropic layer further comprises a compound having a 1,3,5-triazine ring in an amount of 0.01 to 20% by weight of the amount of the discotic liquid crystalline molecule;When the transparent support has optical uniaxiality or optical biaxiality, and the average tilt angle between the disc surface of the discotic liquid crystalline molecules and the transparent support surface is less than 5 °, the discotic liquid crystalline molecules An optical compensation sheet characterized by being oriented.
(2) The optical compensation sheet according to (1), wherein the compound having a 1,3,5-triazine ring is a melamine compound.
(3) The optical compensation sheet according to (2), wherein the melamine compound is a melamine polymer.
(4) The optical compensation sheet according to (1), wherein the transparent support is composed of a polymer film subjected to an unbalanced biaxial stretching process.
(5) In the unbalanced biaxial stretching process, the polymer film was stretched at a magnification in the range of 3 to 100% in a certain direction, and further stretched at a magnification in the range of 6 to 200% in the direction perpendicular thereto. The optical compensation sheet according to (4).
[0007]
  (6)The optical compensation sheet according to (1), wherein the transparent support has an in-plane retardation (Re) defined by the following formula in a range of 10 to 1000 nm.
  Re = (nx−ny) × d
  Where nx and ny are the in-plane refractive indices of the transparent support and d is the thickness of the transparent support.
  (7)The optical compensation sheet according to (1), wherein the transparent support has a thickness direction retardation (Rth) defined by the following formula in a range of 10 to 1000 nm.
  Rth = [{(nx + ny) / 2} -nz] × d
  In the formula, nx and ny are in-plane refractive indexes of the transparent support, nz is the refractive index in the thickness direction of the transparent support, and d is the thickness of the transparent support.
  (8)The optical compensation sheet according to (1), wherein the optical compensation sheet has an in-plane retardation (Re) defined by the following formula in a range of 20 to 200 nm.
  Re = (nx−ny) × d
  Where nx and ny are the in-plane refractive indices of the optical compensation sheet, and d is the thickness of the optical compensation sheet.
  (9)The optical compensation sheet according to (1), wherein the optical compensation sheet has a thickness direction retardation (Rth) defined by the following formula in a range of 70 to 500 nm.
  Rth = [{(nx + ny) / 2} -nz] × d
  In the formula, nx and ny are the in-plane refractive indexes of the optical compensation sheet, nz is the refractive index in the thickness direction of the optical compensation sheet, and d is the thickness of the optical compensation sheet.
[0008]
  (10)An elliptically polarizing plate having a transparent support, an optically anisotropic layer formed from a discotic liquid crystalline molecule, a polarizing film and a transparent protective film,The optically anisotropic layer further comprises a compound having a 1,3,5-triazine ring in an amount of 0.01 to 20% by weight of the amount of the discotic liquid crystalline molecule;When the transparent support has optical uniaxiality or optical biaxiality, and the average tilt angle between the disc surface of the discotic liquid crystalline molecules and the transparent support surface is less than 5 °, the discotic liquid crystalline molecules An elliptically polarizing plate characterized by being oriented.
  (11)A liquid crystal display device comprising a VA mode liquid crystal cell and two polarizing elements disposed on both sides thereof, wherein at least one of the polarizing elements is formed of a transparent support and a discotic liquid crystalline molecule. An elliptically polarizing plate having a layer, a polarizing film and a transparent protective film,The optically anisotropic layer further comprises a compound having a 1,3,5-triazine ring in an amount of 0.01 to 20% by weight of the amount of the discotic liquid crystalline molecule;The discotic liquid crystalline molecule has an optical uniaxial property or an optical biaxial property, and the discotic liquid crystalline molecule has an average tilt angle of less than 5 ° between the disc surface of the discotic liquid crystalline molecule and the transparent support surface. A liquid crystal display device characterized in that:
[0009]
【The invention's effect】
As a result of research, the inventor has found that the average tilt angle between the transparent support having optical uniaxiality or optical biaxiality and the disc surface of the discotic liquid crystalline molecule and the transparent support is less than 5 °. In combination with the optically anisotropic layer in which the discotic liquid crystalline molecules are aligned, the liquid crystal cell having a large number of rod-shaped liquid crystalline molecules aligned substantially vertically is optically compensated accurately. Successful.
In the prior art, an attempt was made to optically compensate for a liquid crystal cell having a large number of rod-like liquid crystal molecules aligned substantially vertically by only the optical anisotropy of the discotic liquid crystal molecules. The discotic liquid crystalline molecules have various alignment forms, but the optical compensation of the liquid crystal cell is limited only by the discotic liquid crystalline molecules. In the present invention, in addition to the optical anisotropy of the discotic liquid crystalline molecules aligned with an average tilt angle of less than 5 °, the optical property of the transparent support having optical uniaxiality or optical biaxiality is achieved. By utilizing the optical anisotropy, it is possible to accurately correspond (optically compensate) to the optical properties of a liquid crystal cell having a large number of rod-like liquid crystal molecules that are aligned substantially vertically.
In addition to the liquid crystal cell, the polarizing film also has viewing angle characteristics. According to the study of the present inventor, it is effective to use a transparent support having optical uniaxiality or optical biaxiality (preferably optical biaxiality) for viewing angle compensation of the polarizing film.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a schematic diagram showing a basic configuration of a transmissive liquid crystal display device.
The transmissive liquid crystal display device shown in FIG. 1A includes, in order from the backlight (BL) side, a transparent protective film (1a), a polarizing film (2a), a transparent support (3a), an optically anisotropic layer ( 4a), lower substrate (5a) of liquid crystal cell, rod-like liquid crystal molecule (6), upper substrate (5b) of liquid crystal cell, optical anisotropic layer (4b), transparent support (3b), polarizing film (2b) And a transparent protective film (1b).
The transparent support and the optically anisotropic layer (3a to 4a and 4b to 3b) constitute an optical compensation sheet. And a transparent protective film, a polarizing film, a transparent support body, and an optically anisotropic layer (1a-4a and 4b-1b) comprise an elliptically polarizing plate.
The transmissive liquid crystal display device shown in FIG. 1B has, in order from the backlight (BL) side, a transparent protective film (1a), a polarizing film (2a), a transparent support (3a), an optically anisotropic layer ( 4a) From the lower substrate (5a) of the liquid crystal cell, the rod-like liquid crystal molecule (6), the upper substrate (5b) of the liquid crystal cell, the transparent protective film (1b), the polarizing film (2b), and the transparent protective film (1c) Become.
The transparent support and the optically anisotropic layer (3a to 4a) constitute an optical compensation sheet. And a transparent protective film, a polarizing film, a transparent support body, and an optically anisotropic layer (1a-4a) comprise an elliptically polarizing plate.
[0011]
The transmissive liquid crystal display device shown in FIG. 1C has a transparent protective film (1a), a polarizing film (2a), a transparent protective film (1b), and a lower substrate of a liquid crystal cell (from the backlight (BL) side). 5a), rod-like liquid crystal molecule (6), upper substrate (5b) of liquid crystal cell, optical anisotropic layer (4b), transparent support (3b), polarizing film (2b), and transparent protective film (1c) Become.
The transparent support and the optically anisotropic layer (4b to 3b) constitute an optical compensation sheet. And a transparent protective film, a polarizing film, a transparent support body, and an optically anisotropic layer (4b-1c) comprise an elliptically polarizing plate.
FIG. 2 is a schematic diagram showing a basic configuration of a reflective liquid crystal display device.
The reflective liquid crystal display device shown in FIG. 2 includes, in order from the bottom, the lower substrate (5a) of the liquid crystal cell, the reflector (RP), the rod-like liquid crystal molecule (6), the upper substrate (5b) of the liquid crystal cell, and the optical anisotropic. It consists of a conductive layer (4), a transparent support (3), a polarizing film (2), and a transparent protective film (1).
The transparent support and the optically anisotropic layer (4-3) constitute an optical compensation sheet. And a transparent protective film, a polarizing film, a transparent support body, and an optically anisotropic layer (4-1) comprise an elliptically polarizing plate.
1 to 2, the arrangement order of the optically anisotropic layer (4) and the transparent support (3) may be reversed.
[0012]
[Transparent support]
In the present invention, a transparent support having optical uniaxiality or optical biaxiality is used. That the support is transparent means that the light transmittance is 80% or more.
In the case of an optically uniaxial support, even if it is optically positive (the refractive index in the optical axis direction is larger than the refractive index in the direction perpendicular to the optical axis), it is negative (the refractive index in the optical axis direction is It may be smaller than the refractive index in the vertical direction. In the case of an optical biaxial support, the refractive indexes nx, ny and nz of the transparent support are all different values (nx ≠ ny ≠ nz).
The in-plane retardation (Re) of the transparent support having optical uniaxiality or optical biaxiality is preferably 10 to 1000 nm, more preferably 15 to 300 nm, and more preferably 20 to 200 nm. Is most preferred. The retardation (Rth) in the thickness direction of the transparent support having optical uniaxiality or optical biaxiality is preferably 10 to 1000 nm, more preferably 15 to 300 nm, and more preferably 20 to 200 nm. More preferably. The in-plane retardation (Re) and the thickness direction retardation (Rth) of the transparent support are respectively defined by the following formulas.
Re = (nx−ny) × d
Rth = [{(nx + ny) / 2} -nz] × d
In the formula, nx and ny are in-plane refractive indexes of the transparent support, nz is the refractive index in the thickness direction of the transparent support, and d is the thickness of the transparent support.
[0013]
As the transparent support having optical anisotropy, a synthetic polymer (eg, polycarbonate, polysulfone, polyethersulfone, polyacrylate, polymethacrylate, norbornene resin) is generally used. However, by (1) using a retardation increasing agent described in the specification of European Patent 0911656A2, (2) decreasing the acetylation degree of cellulose acetate, or (3) producing a film by a cooling dissolution method, optical A cellulose ester film having anisotropy can also be produced.
The transparent support made of a polymer film is preferably formed by a solvent cast method.
[0014]
In order to obtain optical uniaxiality or optical biaxiality, the polymer film is preferably subjected to a stretching treatment.
When an optical uniaxial support is produced, a normal uniaxial stretching process or biaxial stretching process may be performed.
When producing an optical biaxial support, it is preferable to perform an unbalanced biaxial stretching process. In unbalanced biaxial stretching, the polymer film is stretched in a certain direction (for example, 3 to 100%, preferably 5 to 30%) in a certain direction, and further in the direction perpendicular thereto (for example, 6 to 200%, preferably 10 to 90%). The bi-directional stretching process may be performed simultaneously.
The stretching direction (the direction in which the stretching ratio is high in unbalanced biaxial stretching) and the in-plane slow axis of the film after stretching are preferably substantially the same direction. The angle between the stretching direction and the slow axis is preferably less than 10 °, more preferably less than 5 °, and most preferably less than 3 °.
[0015]
A transparent support having optical uniaxiality or optical biaxiality and a transparent support having optical isotropy (eg, cellulose acetate film) may be laminated.
The thickness of the transparent support is preferably 10 to 500 μm, and more preferably 50 to 200 μm.
In order to improve the adhesion between the transparent support and the layer (adhesive layer, alignment film or optically anisotropic layer) provided on the transparent support, surface treatment (eg, glow discharge treatment, corona discharge treatment, ultraviolet light ( UV) treatment, flame treatment).
An ultraviolet absorber may be added to the transparent support.
An adhesive layer (undercoat layer) may be provided on the transparent support. The adhesive layer is described in JP-A-7-333433. The thickness of the adhesive layer is preferably 0.1 to 2 μm, and more preferably 0.2 to 1 μm.
[0016]
[Alignment film]
The alignment film is an organic compound (eg, ω-tricosanoic acid) formed by rubbing treatment of an organic compound (preferably polymer), oblique deposition of an inorganic compound, formation of a layer having a microgroove, or Langmuir-Blodgett method (LB film). , Dioctadecylmethylammonium chloride, methyl stearylate). Furthermore, an alignment film in which an alignment function is generated by application of an electric field, application of a magnetic field, or light irradiation is also known. An alignment film formed by a polymer rubbing treatment is particularly preferable. The rubbing treatment is carried out by rubbing the surface of the polymer layer several times in a certain direction with paper or cloth.
In order to align the discotic liquid crystal molecules in a state where the average tilt angle is less than 5 °, it is preferable to use a polymer (ordinary alignment film polymer) that does not decrease the surface energy of the alignment film for the alignment film.
The thickness of the alignment film is preferably 0.01 to 5 μm, and more preferably 0.05 to 1 μm.
In addition, after aligning the discotic liquid crystalline molecules of the optically anisotropic layer using the alignment film, the optically anisotropic layer may be transferred onto the transparent support. The discotic liquid crystalline molecules fixed in the alignment state can maintain the alignment state even without the alignment film.
In the present invention, since the discotic liquid crystalline molecules are aligned with an average tilt angle of less than 5 °, there is no need for rubbing treatment, and in some cases, no alignment film is required. However, for the purpose of improving the adhesion between the liquid crystal molecules and the transparent support, an alignment film (described in JP-A-9-152509) forming a chemical bond with the liquid crystal molecules at the interface may be used. When an alignment film is used for the purpose of improving adhesion, rubbing treatment need not be performed.
[0017]
[Optically anisotropic layer]
The optically anisotropic layer is formed from discotic liquid crystalline molecules. The discotic liquid crystal molecules are aligned in a state where the average inclination angle between the disc surface of the discotic liquid crystal molecules and the transparent support surface is less than 5 °.
As a result of combining the above-mentioned transparent support having optical uniaxiality or optical biaxiality and discotic liquid crystalline molecules having an average tilt angle of less than 5 °, the entire optical compensation sheet is obtained. The in-plane retardation (Re) is preferably 20 to 200 nm, more preferably 20 to 100 nm, and most preferably 20 to 70 nm. The retardation (Rth) in the thickness direction of the entire optical compensation sheet is preferably 70 to 500 nm, more preferably 70 to 300 m, and further preferably 70 to 200 nm. In-plane retardation (Re) and thickness direction retardation (Rth) of the optical compensation sheet are defined by the following equations, respectively.
Re = (nx−ny) × d
Rth = [{(nx + ny) / 2} -nz] × d
In the formula, nx and ny are the in-plane refractive indexes of the optical compensation sheet, nz is the refractive index in the thickness direction of the optical compensation sheet, and d is the thickness of the optical compensation sheet.
[0018]
The discotic liquid crystalline molecules are preferably fixed in an aligned state. The alignment state can be fixed using a polymer binder, but is preferably fixed by a polymerization reaction.
Discotic liquid crystalline molecules are described in various literature (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by the Chemical Society of Japan, Quarterly Review, No. 22, Liquid Crystal Chemistry, Chapter 5, Chapter 10 Section 2 (1994); B. Kohne et al., Angew. Chem. Soc. Chem. Comm., Page 1794 (1985); J. Zhang et al., J Am. Chem. Soc., Vol. 116, page 2655 (1994)). The polymerization of discotic liquid crystalline molecules is described in JP-A-8-27284.
In order to fix the discotic liquid crystalline molecules by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline molecules. However, when the polymerizable group is directly connected to the disc-shaped core, it becomes difficult to maintain the orientation state in the polymerization reaction. Therefore, a linking group is introduced between the discotic core and the polymerizable group. Accordingly, the discotic liquid crystalline molecule is preferably a compound represented by the following formula (I).
[0019]
(I) D (-LQ)_n
Where D is a discotic core; L is a divalent linking group; Q is a polymerizable group; and n is an integer from 4 to 12.
Examples of the disk-shaped core (D) of the above formula are shown below. In each of the following examples, LQ (or QL) means a combination of a divalent linking group (L) and a polymerizable group (Q).
[0020]
[Chemical 1]

[0021]
[Chemical formula 2]

[0022]
[Chemical Formula 3]

[0023]
[Formula 4]

[0024]
[Chemical formula 5]

[0025]
[Chemical 6]

[0026]
[Chemical 7]

[0027]
In the above formula, the divalent linking group (L) is a divalent group selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, —S—, and combinations thereof. The linking group is preferably. The divalent linking group (L) is a combination of at least two divalent groups selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, —CO—, —NH—, —O—, and —S—. More preferably, it is a group. The divalent linking group (L) is most preferably a group obtained by combining at least two divalent groups selected from the group consisting of an alkylene group, an alkenylene group, an arylene group, -CO- and -O-. The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The number of carbon atoms in the arylene group is preferably 6 to 10. The alkylene group, alkenylene group and arylene group may have a substituent (eg, alkyl group, halogen atom, cyano, alkoxy group, acyloxy group).
Examples of the divalent linking group (L) are shown below. The left side is bonded to the discotic core (D), and the right side is bonded to the polymerizable group (Q). AL represents an alkylene group or an alkenylene group, and AR represents an arylene group.
[0028]
L1: -AL-CO-O-AL-
L2: -AL-CO-O-AL-O-
L3: -AL-CO-O-AL-O-AL-
L4: -AL-CO-O-AL-O-CO-
L5: -CO-AR-O-AL-
L6: -CO-AR-O-AL-O-
L7: -CO-AR-O-AL-O-CO-
L8: -CO-NH-AL-
L9: -NH-AL-O-
L10: -NH-AL-O-CO-
L11: -O-AL-
L12: -O-AL-O-
L13: -O-AL-O-CO-
[0029]
L14: -O-AL-O-CO-NH-AL-
L15: -O-AL-S-AL-
L16: -O-CO-AL-AR-O-AL-O-CO-
L17: -O-CO-AR-O-AL-CO-
L18: -O-CO-AR-O-AL-O-CO-
L19: -O-CO-AR-O-AL-O-AL-O-CO-
L20: -O-CO-AR-O-AL-O-AL-O-AL-O-CO-
L21: -S-AL-
L22: -S-AL-O-
L23: -S-AL-O-CO-
L24: -S-AL-S-AL-
L25: -S-AR-AL-
[0030]
The polymerizable group (Q) of the formula (I) is determined according to the type of polymerization reaction. Examples of the polymerizable group (Q) are shown below.
[0031]
[Chemical 8]

[0032]
The polymerizable group (Q) is preferably an unsaturated polymerizable group (Q1 to Q7), an epoxy group (Q8) or an aziridinyl group (Q9), more preferably an unsaturated polymerizable group, and an ethylenic group. Most preferably, it is an unsaturated polymerizable group (Q1 to Q6).
In the formula (I), n is an integer of 4 to 12. A specific number is determined according to the type of discotic core (D). In addition, although the combination of several L and Q may differ, it is preferable that it is the same.
[0033]
Two or more kinds of discotic liquid crystal molecules may be used in combination. For example, a polymerizable discotic liquid crystalline molecule and a non-polymerizable discotic liquid crystalline molecule as described above can be used in combination.
The non-polymerizable discotic liquid crystalline molecule is preferably a compound in which the polymerizable group (Q) of the polymerizable discotic liquid crystalline molecule is changed to a hydrogen atom or an alkyl group. That is, the non-polymerizable discotic liquid crystal molecule is preferably a compound represented by the following formula (Ia).
(Ia) D (-LR)_n
Where D is a discotic core; L is a divalent linking group; R is a hydrogen atom or an alkyl group; and n is an integer from 4 to 12.
The example of the discotic core (D) of the formula (Ia) is the same as the above-described example of the polymerizable discotic liquid crystal molecule except that LQ (or QL) is changed to LR (or RL).
Examples of the divalent linking group (L) are the same as the examples of the polymerizable discotic liquid crystal molecules.
The alkyl group for R preferably has 1 to 40 carbon atoms, and more preferably 1 to 30 carbon atoms. A chain alkyl group is preferred to a cyclic alkyl group, and a linear alkyl group is preferred to a branched chain alkyl group. R is particularly preferably a hydrogen atom or a linear alkyl group having 1 to 30 carbon atoms.
[0034]
  In order to align the discotic liquid crystalline molecules in a state where the average tilt angle between the disc surface of the discotic liquid crystalline molecules and the transparent support surface is less than 5 °, a certain range of compounds that can be phase separated from the discotic liquid crystalline molecules Is preferably used in an amount of.
[0035]
  The compound that can be phase-separated from the discotic liquid crystalline molecule includes a fluorine-containing surfactant and a compound having a 1,3,5-triazine ring.
[0036]
The fluorine-containing surfactant is composed of a hydrophobic group containing a fluorine atom, a nonionic, anionic, cationic or amphoteric hydrophilic group and an optionally provided linking group. The fluorine-containing surfactant composed of one hydrophobic group and one hydrophilic group is represented by the following formula (II).
[0037]
(II) Rf-L^Three-Hy
Where Rf is a monovalent hydrocarbon residue substituted with a fluorine atom;^ThreeIs a single bond or a divalent linking group; and Hy is a hydrophilic group.
Rf in the formula (II) functions as a hydrophobic group. The hydrocarbon residue is preferably an alkyl group or an aryl group. The alkyl group preferably has 3 to 30 carbon atoms, and the aryl group preferably has 6 to 30 carbon atoms.
Some or all of the hydrogen atoms contained in the hydrocarbon residue are substituted with fluorine atoms. It is preferable to substitute 50% or more of the hydrogen atoms contained in the hydrocarbon residue with fluorine atoms, more preferably 60% or more, more preferably 70% or more, and more preferably 80% or more. Most preferred is substitution.
The remaining hydrogen atoms may be further substituted with other halogen atoms (eg, chlorine atom, bromine atom).
An example of Rf is shown below.
[0038]
Rf1: n-C₈ F₁₇−
Rf2: n-C₆ F₁₃−
Rf3: Cl- (CF₂ -CFCl)_Three -CF₂ −
Rf4: H- (CF₂ )₈ −
Rf5: H- (CF₂ )_Ten−
Rf6: n-C₉ F₁₉−
Rf7: Pentafluorophenyl
Rf8: n-C₇ F₁₅−
Rf9: Cl- (CF₂ -CFCl)₂ -CF₂ −
Rf10: H- (CF₂ )_Four −
Rf11: H- (CF₂ )₆ −
Rf12: Cl- (CF₂ )₆ −
Rf13: C_Three F₇ −
[0039]
In the formula (II), the divalent linking group is an alkylene group, an arylene group, a divalent heterocyclic residue, -CO-, -NR- (R is an alkyl group having 1 to 5 carbon atoms or a hydrogen atom. ), -O-, -SO₂ It is preferably a divalent linking group selected from the group consisting of-and combinations thereof.
L in formula (II)^ThreeAn example of this is shown below. The left side is bonded to the hydrophobic group (Rf), and the right side is bonded to the hydrophilic group (Hy). AL represents an alkylene group, AR represents an arylene group, and Hc represents a divalent heterocyclic residue. The alkylene group, arylene group, and divalent heterocyclic residue may have a substituent (eg, an alkyl group).
[0040]
L0: Single bond
L31: -SO₂ -NR-
L32: -AL-O-
L33: -CO-NR-
L34: -AR-O-
L35: -SO₂ -NR-AL-CO-O-
L36: -CO-O-
L37: -SO₂ -NR-AL-O-
L38: -SO₂ -NR-AL-
L39: -CO-NR-AL-
L40: -AL¹ -O-AL² −
L41: -Hc-AL-
L42: -SO₂ -NR-AL¹ -O-AL² −
L43: -AR-
L44: -O-AR-SO₂ -NR-AL-
L45: -O-AR-SO₂ -NR-
L46: -O-AR-O-
[0041]
Hy in the formula (II) is any one of a nonionic hydrophilic group, an anionic hydrophilic group, a cationic hydrophilic group, or a combination thereof (an amphoteric hydrophilic group). Nonionic hydrophilic groups are particularly preferred.
Examples of Hy in formula (II) are shown below.
[0042]

[0043]
Nonionic hydrophilic groups (Hy1, Hy2, Hy3) are preferred, and hydrophilic groups (Hy1) made of polyethylene oxide are most preferred.
Specific examples of the fluorine-containing surfactant represented by the formula (II) include the above Rf, L^ThreeAnd examples of Hy are cited.
[0044]
FS-1: Rf1-L31 (R = C_Three H₇ ) -Hy1 (n = 6)
FS-2: Rf1-L31 (R = C_Three H₇ ) -Hy1 (n = 11)
FS-3: Rf1-L31 (R = C_Three H₇ ) -Hy1 (n = 16)
FS-4: Rf1-L31 (R = C_Three H₇ ) -Hy1 (n = 21)
FS-5: Rf1-L31 (R = C₂ H_Five ) -Hy1 (n = 6)
FS-6: Rf1-L31 (R = C₂ H_Five ) -Hy1 (n = 11)
FS-7: Rf1-L31 (R = C₂ H_Five ) -Hy1 (n = 16)
FS-8: Rf1-L31 (R = C₂ H₇ ) -Hy1 (n = 21)
FS-9: Rf2-L31 (R = C_Three H₇ ) -Hy1 (n = 6)
FS-10: Rf2-L31 (R = C_Three H₇ ) -Hy1 (n = 11)
FS-11: Rf2-L31 (R = C_Three H₇ ) -Hy1 (n = 16)
FS-12: Rf2-L31 (R = C_Three H₇ ) -Hy1 (n = 21)
FS-13: Rf3-L32 (AL = CH₂ ) -Hy1 (n = 5)
FS-14: Rf3-L32 (AL = CH₂ ) -Hy1 (n = 10)
FS-15: Rf3-L32 (AL = CH₂ ) -Hy1 (n = 15)
FS-16: Rf3-L32 (AL = CH₂ ) -Hy1 (n = 20)
FS-17: Rf4-L33 (R = C_Three H₇ ) -Hy1 (n = 7)
FS-18: Rf4-L33 (R = C_Three H₇ ) -Hy1 (n = 13)
FS-19: Rf4-L33 (R = C_Three H₇ ) -Hy1 (n = 19)
FS-20: Rf4-L33 (R = C_Three H₇ ) -Hy1 (n = 25)
[0045]
FS-21: Rf5-L32 (AL = CH₂ ) -Hy1 (n = 11)
FS-22: Rf5-L32 (AL = CH₂ ) -Hy1 (n = 15)
FS-23: Rf5-L32 (AL = CH₂ ) -Hy1 (n = 20)
FS-24: Rf5-L32 (AL = CH₂ ) -Hy1 (n = 30)
FS-25: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 11)
FS-26: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 17)
FS-27: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 23)
FS-28: Rf6-L34 (AR = p-phenylene) -Hy1 (n = 29)
FS-29: Rf1-L35 (R = C_Three H₇ , AL = CH₂ ) -Hy1 (n = 20)
FS-30: Rf1-L35 (R = C_Three H₇ , AL = CH₂ ) -Hy1 (n = 30)
FS-31: Rf1-L35 (R = C_Three H₇ , AL = CH₂ ) -Hy1 (n = 40)
FS-32: Rf1-L36-Hy1 (n = 5)
FS-33: Rf1-L36-Hy1 (n = 10)
FS-34: Rf1-L36-Hy1 (n = 15)
FS-35: Rf1-L36-Hy1 (n = 20)
FS-36: Rf7-L36-Hy1 (n = 8)
FS-37: Rf7-L36-Hy1 (n = 13)
FS-38: Rf7-L36-Hy1 (n = 18)
FS-39: Rf7-L36-Hy1 (n = 25)
[0046]
FS-40: Rf1-L0-Hy1 (n = 6)
FS-41: Rf1-L0-Hy1 (n = 11)
FS-42: Rf1-L0-Hy1 (n = 16)
FS-43: Rf1-L0-Hy1 (n = 21)
FS-44: Rf1-L31 (R = C_Three H₇ ) -Hy2 (n = 7, R¹ = C₂ H_Five )
FS-45: Rf1-L31 (R = C_Three H₇ ) -Hy2 (n = 13, R¹ = C₂ H_Five )
FS-46: Rf1-L31 (R = C_Three H₇ ) -Hy2 (n = 20, R¹ = C₂ H_Five )
FS-47: Rf1-L31 (R = C_Three H₇ ) -Hy2 (n = 28, R¹ = C₂ H_Five )
FS-48: Rf8-L32 (AL = CH₂ ) -Hy1 (n = 5)
FS-49: Rf8-L32 (AL = CH₂ ) -Hy1 (n = 10)
FS-50: Rf8-L32 (AL = CH₂ ) -Hy1 (n = 15)
FS-51: Rf8-L32 (AL = CH₂ ) -Hy1 (n = 20)
FS-52: Rf1-L37 (R = C_Three H₇ , AL = CH₂CH₂) -Hy3 (n = 5)
FS-53: Rf1-L37 (R = C_Three H₇ , AL = CH₂CH₂) -Hy3 (n = 7)
FS-54: Rf1-L37 (R = C_Three H₇ , AL = CH₂CH₂) -Hy3 (n = 9)
FS-55: Rf1-L37 (R = C_Three H₇ , AL = CH₂CH₂) -Hy3 (n = 12)
FS-56: Rf9-L0-Hy4 (M = H)
FS-57: Rf3-L0-Hy4 (M = H)
FS-58: Rf1-L38 (R = C_Three H₇ , AL = CH₂ ) -Hy4 (M = K)
FS-59: Rf4-L39 (R = C_Three H₇ , AL = CH₂ ) -Hy4 (M = Na)
[0047]
FS-60: Rf1-L0-Hy5 (M = K)
FS-61: Rf10-L40 (AL¹ = CH₂ , AL² = CH₂CH₂) -Hy5 (M = Na)
FS-62: Rf11-L40 (AL¹ = CH₂ , AL² = CH₂CH₂) -Hy5 (M = Na)
FS-63: Rf5-L40 (AL¹ = CH₂ , AL² = CH₂CH₂) -Hy5 (M = Na)
FS-64: Rf1-L38 (R = C_ThreeH₇, AL = CH₂CH₂CH₂ ) -Hy5 (M = Na)
FS-65: Rf1-L31 (R = C_Three H₇ ) -Hy6 (n = 5, M = Na)
FS-66: Rf1-L31 (R = C_Three H₇ ) -Hy6 (n = 10, M = Na)
FS-67: Rf1-L31 (R = C_Three H₇ ) -Hy6 (n = 15, M = Na)
FS-68: Rf1-L31 (R = C_Three H₇ ) -Hy6 (n = 20, M = Na)
FS-69: Rf1-L38 (R = C₂ H_Five , AL = CH₂ CH₂ ) -Hy7
FS-70: Rf1-L38 (R = H, AL = CH₂CH₂CH₂ ) -Hy8 (X = I)
FS-71: Rf11-L41 (the following Hc, AL = CH₂CH₂CH₂ ) -Hy6 (M is dissociated)
[0048]
[Chemical 9]

[0049]
FS-72: Rf1-L42 (R = C_ThreeH₇, AL¹= CH₂CH₂, AL²= CH₂CH₂CH₂) -Hy6 (M = Na)
FS-73: Rf12-L0-Hy5 (M = Na)
FS-74: Rf13-L43 (AR = o-phenylene) -Hy6 (M = K)
FS-75: Rf13-L43 (AR = m-phenylene) -Hy6 (M = K)
FS-76: Rf13-L43 (AR = p-phenylene) -Hy6 (M = K)
FS-77: Rf6-L44 (R = C₂H_Five, AL = CH₂CH₂) -Hy5 (M = H)
FS-78: Rf6-L45 (AR = p-phenylene, R = C₂H_Five) -Hy1 (n = 9)
FS-79: Rf6-L45 (AR = p-phenylene, R = C₂H_Five) -Hy1 (n = 14)
FS-80: Rf6-L45 (AR = p-phenylene, R = C₂H_Five) -Hy1 (n = 19)
FS-81: Rf6-L45 (AR = p-phenylene, R = C₂H_Five) -Hy1 (n = 28)
FS-82: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 5)
FS-83: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 10)
FS-84: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 15)
FS-85: Rf6-L46 (AR = p-phenylene) -Hy1 (n = 20)
[0050]
A fluorine-containing surfactant having two or more hydrophobic groups or hydrophilic groups containing a fluorine atom may be used. Examples of the fluorine-containing surfactant having two or more hydrophobic groups or hydrophilic groups are shown below.
[0051]
Embedded image

[0052]
FS-86: n1 + n2 = 12, FS-87: n1 + n2 = 18, FS-88: n1 + n2 = 24
[0053]
Embedded image

[0054]
FS-89: n1 + n2 = 20, FS-90: n1 + n2 = 30, FS-91: n1 + n2 = 40
[0055]
Embedded image

[0056]
FS-92: n = 5, FS-93: n = 10, FS-94: n = 15, FS-95: n = 20
[0057]
Embedded image

[0058]
Two or more fluorine-containing surfactants may be used in combination.
Regarding surfactants, various documents (eg, Hiroshi Horiguchi, “New Surfactant”, Sankyo Publishing (1975), MJ Schick, Nonionic Surfactants, Marcell Dekker Inc., New York, (1967), Japanese Patent Laid-Open No. 7-13293. No.).
The fluorine-containing surfactant is preferably used in an amount of 2 to 30% by weight, more preferably 3 to 25% by weight, more preferably 5 to 10% by weight of the amount of the discotic liquid crystalline molecule. Most preferred to use in amount.
The coating amount of the fluorine-containing surfactant is 25 to 1000 mg / m.²Is preferably in the range of 30 to 500 mg / m²Is more preferably in the range of 35 to 200 mg / m.²Most preferably, it is in the range.
[0059]
The compound having a 1,3,5-triazine ring is preferably a compound represented by the following formula (III).
[0060]
Embedded image

[0061]
Where X¹, X²And X^ThreeEach independently represents a single bond, —NR— (wherein R is an alkyl group having 1 to 30 carbon atoms or a hydrogen atom), —O— or —S—; and R³¹, R³²And R³³Are each independently an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
The compound represented by the formula (III) is particularly preferably a melamine compound. In the melamine compound, X in the formula (III)¹, X²Or X^ThreeIs -NR- or X¹, X²Or X^ThreeIs a single bond and R³¹, R³²And R³³Is a heterocyclic group having a free valence on the nitrogen atom. The melamine compound will be described in more detail with reference to formula (IV).
R in —NR— is particularly preferably a hydrogen atom.
R³¹, R³²And R³³Is particularly preferably an aryl group.
[0062]
The alkyl group is preferably a chain alkyl group rather than a cyclic alkyl group. A linear alkyl group is preferred to a branched alkyl group. The alkyl group preferably has 1 to 30 carbon atoms, more preferably 2 to 30 carbon atoms, still more preferably 4 to 30 carbon atoms, and most preferably 6 to 30 carbon atoms. The alkyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy, ethoxy, epoxyethyloxy) and an acyloxy group (eg, acryloyloxy, methacryloyloxy).
The alkenyl group is preferably a chain alkenyl group rather than a cyclic alkenyl group. A linear alkenyl group is preferable to a branched chain alkenyl group. The alkenyl group preferably has 2 to 30 carbon atoms, more preferably 3 to 30 carbon atoms, still more preferably 4 to 30 carbon atoms, and most preferably 6 to 30 carbon atoms. The alkenyl group may have a substituent. Examples of the substituent include a halogen atom, an alkoxy group (eg, methoxy, ethoxy, epoxyethyloxy) and an acyloxy group (eg, acryloyloxy, methacryloyloxy).
[0063]
The aryl group is preferably phenyl or naphthyl, particularly preferably phenyl.
The aryl group may have a substituent. Examples of the substituent include a halogen atom, hydroxyl, cyano, nitro, carboxyl, alkyl group, alkenyl group, aryl group, alkoxy group, alkenyloxy group, aryloxy group, acyloxy group, alkoxycarbonyl group, alkenyloxycarbonyl group, Aryloxycarbonyl group, sulfamoyl, alkyl-substituted sulfamoyl group, alkenyl-substituted sulfamoyl group, aryl-substituted sulfamoyl group, sulfonamido group, carbamoyl, alkyl-substituted carbamoyl group, alkenyl-substituted carbamoyl group, aryl-substituted carbamoyl group, amide group, alkylthio group, alkenyl A thio group, an arylthio group and an acyl group are included.
The alkyl group has the same definition as the alkyl group described above. The alkyl part of the alkoxy group, the acyloxy group, the alkoxycarbonyl group, the alkyl-substituted sulfamoyl group, the sulfonamide group, the alkyl-substituted carbamoyl group, the amide group, the alkylthio group and the acyl group is the same as the alkyl group described above.
The alkenyl group has the same definition as the alkenyl group described above. The alkenyl part of the alkenyloxy group, acyloxy group, alkenyloxycarbonyl group, alkenyl-substituted sulfamoyl group, sulfonamide group, alkenyl-substituted carbamoyl group, amide group, alkenylthio group and acyl group is the same as the alkenyl group described above.
Examples of the aryl group include phenyl, α-naphthyl, β-naphthyl, 4-methoxyphenyl, 3,4-diethoxyphenyl, 4-octyloxyphenyl and 4-dodecyloxyphenyl. Examples of the aryloxy group, acyloxy group, aryloxycarbonyl group, aryl-substituted sulfamoyl group, sulfonamido group, aryl-substituted carbamoyl group, amide group, arylthio group, and acyl group are the same as the above examples of the aryl group.
[0064]
X¹, X²Or X^ThreeIt is preferable that the heterocyclic group in which is —NR—, —O— or —S— has aromaticity. The heterocycle having aromaticity is generally an unsaturated heterocycle, preferably a heterocycle having the largest number of double bonds. The heterocyclic ring is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and most preferably a 6-membered ring. The hetero atom of the heterocyclic ring is preferably N, S or O, and particularly preferably N. As the heterocyclic ring having aromaticity, a pyridine ring (2-pyridyl or 4-pyridyl as the heterocyclic group) is particularly preferable. The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety.
X¹, X²Or X^ThreeWhen is a single bond, the heterocyclic group is preferably a heterocyclic group having a free valence on the nitrogen atom. The heterocyclic group having a free valence on the nitrogen atom is preferably a 5-membered ring, 6-membered ring or 7-membered ring, more preferably a 5-membered ring or 6-membered ring, and a 5-membered ring. Is most preferred. The heterocyclic group may have a plurality of nitrogen atoms. In addition, the heterocyclic group may have a hetero atom other than the nitrogen atom (eg, O, S). The heterocyclic group may have a substituent. Examples of the substituent of the heterocyclic group are the same as the examples of the substituent of the aryl moiety. Examples of heterocyclic groups having free valences on nitrogen atoms are shown below.
[0065]
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[0066]
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[0067]
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[0068]
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[0069]
R³¹, R³²And R³³Preferably, at least one of these includes an alkylene or alkenylene moiety having 9 to 30 carbon atoms. The alkylene or alkenylene moiety having 9 to 30 carbon atoms is preferably linear. The alkylene moiety or alkenylene moiety is preferably contained in the substituent of the aryl group.
R³¹, R³²And R³³At least one of these preferably has a polymerizable group as a substituent. The compound having a 1,3,5-triazine ring preferably has at least two polymerizable groups. The polymerizable group is R³¹, R³²Or R³³It is preferable that it is located at the terminal of.
By introducing a polymerizable group into a compound having a 1,3,5-triazine ring, an optical anisotropy is produced in a state where a compound having a 1,3,5-triazine ring and a discotic liquid crystalline molecule are polymerized. Can be included in the layer.
R having a polymerizable group as a substituent³¹, R³²Or R³³Is represented by the following formula (Rp).
[0070]
(Rp) -L^Five(-Q)_n
Where L^FiveIs an (n + 1) -valent linking group; Q is a polymerizable group; and n is an integer of 1 to 5.
In the formula (RpI), an (n + 1) -valent linking group (L^Five) Is an alkylene group, an alkenylene group, an n + 1 valent aromatic group, a divalent heterocyclic residue, -CO-, -NR- (R is an alkyl group having 1 to 30 carbon atoms or a hydrogen atom),- O-, -S- and -SO₂A linking group obtained by combining at least two groups selected from the group consisting of — is preferable. The alkylene group preferably has 1 to 12 carbon atoms. The alkenylene group preferably has 2 to 12 carbon atoms. The aromatic group preferably has 6 to 10 carbon atoms.
L in formula (Rp)^FiveAn example of this is shown below. X on the left side of formula (III)¹, X²Or X^ThreeBound to (X¹, X²Or X^ThreeIs directly bonded to the 1,3,5-triazine ring), the right side is bonded to the polymerizable group (Q) (n in L53 to L59). AL represents an alkylene group or alkenylene group, Hc represents a divalent heterocyclic residue, and AR represents an aromatic group. The alkylene group, alkenylene group, heterocyclic residue and aromatic group may have a substituent (eg, alkyl group, halogen atom).
[0071]
L51: -AL-O-CO-
L52: -AL-O-
L53: -AR (-O-AL-O-CO-)_n
L54: -AR (-O-AL-O-)_n
L55: -AR (-O-CO-AL-O-CO-)_n
L56: -AR (-CO-O-AL-O-CO-)_n
L57: -AR (-O-CO-AR-O-AL-O-CO-)_n
L58: -AR (-NR-SO₂-AL-O-CO-)_n
L59: -AR (-SO₂-NR-AL-O-CO-)_n
[0072]
Examples of the polymerizable group (Q) in the formula (Rp) are the same as the examples (Q1 to Q17) of the polymerizable group of the discotic liquid crystalline molecule. The polymerizable group is used for polymerizing a compound having a 1,3,5-triazine ring and a discotic liquid crystalline molecule. Therefore, the polymerizable group of the compound having a 1,3,5-triazine ring and the polymerizable group of the discotic liquid crystal molecule are preferably similar functional groups. Therefore, like the polymerizable group of the discotic liquid crystalline molecule, the polymerizable group (Q) of the compound having a 1,3,5-triazine ring is an unsaturated polymerizable group (Q1 to Q7), an epoxy group (Q8). ) Or an aziridinyl group (Q9), more preferably an unsaturated polymerizable group, and most preferably an ethylenically unsaturated polymerizable group (Q1 to Q6).
When n is plural (2 to 5), a linking group (L^Five) Preferably contains an n + 1 valent aromatic group and is branched at the aromatic group. n is preferably an integer of 1 to 3.
[0073]
Specific examples of compounds having a 1,3,5-triazine ring (excluding melamine compounds) are shown below.
[0074]
Embedded image

[0075]
TR-1: R³¹, R³², R³³:-( CH₂)₉-O-CO-CH = CH₂
TR-2: R³¹, R³², R³³:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
TR-3: R³¹, R³²:-( CH₂)₉-O-CO-CH = CH₂; R³³:-( CH₂)₁₂-CH_Three
TR-4: R³¹, R³²:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R³³:-( CH₂)₁₂-CH_Three
TR-5: R³¹:-( CH₂)₉-O-CO-CH = CH₂; R³², R³³:-( CH₂)₁₂-CH_Three
TR-6: R³¹:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R³², R³³:-( CH₂)₁₂-CH_Three
TR-7: R³¹, R³²:-( CH₂)_Four-O-CO-CH = CH₂; R³³:-( CH₂)₁₂-CH_Three
TR-8: R³¹:-( CH₂)_Four-O-CO-CH = CH₂; R³², R³³:-( CH₂)₁₂-CH_Three
TR-9: R³¹, R³², R³³:-( CH₂)₉-O-EpEt
TR-10: R³¹, R³², R³³:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-EpEt
TR-11: R³¹, R³²:-( CH₂)₉-O-EpEt; R³³:-( CH₂)₁₂-CH_Three
TR-12: R³¹, R³², R³³:-( CH₂)₉-O-CH = CH₂
TR-13: R³¹, R³²:-( CH₂)₉-O-CH = CH₂; R³³:-( CH₂)₁₂-CH_Three
(Ii) EpEt: Epoxyethyl
[0076]
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[0077]

[0078]

[0079]

[0080]

[0081]
The compound having a 1,3,5-triazine ring is preferably a melamine compound represented by the following formula (IV).
[0082]
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[0083]
Where R⁴¹, R⁴³And R⁴⁵Are each independently an alkyl group having 1 to 30 carbon atoms or a hydrogen atom, and R⁴², R⁴⁴And R⁴⁶Are each independently an alkyl group, an alkenyl group, an aryl group or a heterocyclic group, or R⁴¹And R⁴², R⁴³And R⁴⁴Or R⁴⁵And R⁴⁶Combine to form a heterocycle.
R⁴¹, R⁴³And R⁴⁵Is preferably an alkyl group having 1 to 20 carbon atoms or a hydrogen atom, more preferably an alkyl group having 1 to 10 carbon atoms or a hydrogen atom, and an alkyl having 1 to 6 carbon atoms. It is more preferably a group or a hydrogen atom, and most preferably a hydrogen atom.
R⁴², R⁴⁴And R⁴⁶Is particularly preferably an aryl group.
The definitions and substituents of the alkyl group, alkenyl group, aryl group and heterocyclic group are the same as the definitions and substituents of each group described in the formula (III).
R⁴¹And R⁴², R⁴³And R⁴⁴Or R⁴⁵And R⁴⁶The heterocyclic ring formed by bonding is the same as the heterocyclic group having a free valence on the nitrogen atom described in the formula (III).
[0084]
R⁴², R⁴⁴And R⁴⁶Preferably, at least one of these includes an alkylene or alkenylene moiety having 9 to 30 carbon atoms. The alkylene or alkenylene moiety having 9 to 30 carbon atoms is preferably linear. The alkylene moiety or alkenylene moiety is preferably contained in the substituent of the aryl group.
R⁴², R⁴⁴And R⁴⁶At least one of these preferably has a polymerizable group as a substituent. The melamine compound preferably has at least two polymerizable groups. The polymerizable group is R⁴², R⁴⁴And R⁴⁶It is preferable that it is located at the terminal of.
By introducing a polymerizable group into the melamine compound, the optically anisotropic layer can be included in a state where the melamine compound and the discotic liquid crystalline molecule are polymerized.
R having a polymerizable group as a substituent⁴², R⁴⁴And R⁴⁶Is the same as the group represented by the aforementioned formula (Rp).
[0085]
Specific examples of the melamine compound are shown below.
[0086]
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[0087]
MM-1: R⁴³, R⁴⁴, R⁵³, R⁵⁴, R⁶³, R⁶⁴: -O- (CH₂)₉-CH_Three
MM-2: R⁴³, R⁴⁴, R⁵³, R⁵⁴, R⁶³, R⁶⁴: -O- (CH₂)₁₁-CH_Three
MM-3: R⁴³, R⁴⁴, R⁵³, R⁵⁴, R⁶³, R⁶⁴: -O- (CH₂)₁₅-CH_Three
MM-4: R⁴⁴, R⁵⁴, R⁶⁴: -O- (CH₂)₉-CH_Three
MM-5: R⁴⁴, R⁵⁴, R⁶⁴: -O- (CH₂)₁₅-CH_Three
MM-6: R⁴³, R⁵³, R⁶³: -O-CH_Three; R⁴⁴, R⁵⁴, R⁶⁴: -O- (CH₂)₁₇-CH_Three
MM-7: R⁴⁴, R⁵⁴, R⁶⁴: -CO-O- (CH₂)₁₁-CH_Three
MM-8: R⁴⁴, R⁵⁴, R⁶⁴: -SO₂-NH- (CH₂)₁₇-CH_Three
MM-9: R⁴³, R⁵³, R⁶³: -O-CO- (CH₂)₁₅-CH_Three
MM-10: R⁴², R⁵², R⁶²: -O- (CH₂)₁₇-CH_Three
MM-11: R⁴², R⁵², R⁶²: -O-CH_Three; R⁴³, R⁵³, R⁶³: -CO-O- (CH₂)₁₁-CH_Three
MM-12: R⁴², R⁵², R⁶²: -Cl; R⁴³, R⁵³, R⁶³: -CO-O- (CH₂)₁₁-CH_Three
MM-13: R⁴², R⁵², R⁶²: -O- (CH₂)₁₁-CH_Three; R⁴⁵, R⁵⁵, R⁶⁵: -SO₂-NH-iso-C_ThreeH₇
[0088]

[0089]

[0090]
MM-34: R⁴⁴, R⁵⁴, R⁶⁴: -O- (CH₂)₉-O-CO-CH = CH₂
MM-35: R⁴³, R⁴⁴, R⁵³, R⁵⁴, R⁶³, R⁶⁴: -O- (CH₂)₉-O-CO-CH = CH₂
MM-36: R⁴⁴, R⁵⁴, R⁶⁴: -O- (CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
MM-37: R⁴³, R⁴⁴, R⁵³, R⁵⁴, R⁶³, R⁶⁴: -O- (CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
MM-38: R⁴³, R⁴⁵, R⁵³, R⁵⁵, R⁶³, R⁶⁵: -O- (CH₂)₉-O-CO-CH = CH₂
MM-39: R⁴³, R⁴⁴, R⁴⁵, R⁵³, R⁵⁴, R⁵⁵, R⁶³, R⁶⁴, R⁶⁵: -O- (CH₂)₉-O-CO-CH = CH₂
MM-40: R⁴⁴, R⁵⁴: -O- (CH₂)_Four-O-CO-CH = CH₂; R⁶⁴: -O- (CH₂)₉-O-CO-CH = CH₂
MM-41: R⁴⁴, R⁵⁴: -O- (CH₂)_Four-O-CO-CH = CH₂; R⁶⁴: -O- (CH₂)₁₂-CH_Three
MM-42: R⁴⁴, R⁵⁴: -O- (CH₂)_Four-O-CO-CH = CH₂; R⁶³, R⁶⁴: -O- (CH₂)₁₂-CH_Three
MM-43: R⁴⁴, R⁵⁴: -O- (CH₂)_Four-O-CO-CH = CH₂; R⁶³, R⁶⁴: -O-CO- (CH₂)₁₁-CH_Three
MM-44: R⁴³, R⁴⁵: -O- (CH₂)₁₂-CH_Three; R⁵⁴, R⁶⁴: -O- (CH₂)₉-O-CO-CH = CH₂
MM-45: R⁴³, R⁴⁴: -O- (CH₂)₆-O-CO-CH = CH₂; R⁵⁴, R⁶⁴: -O- (CH₂)₁₁-CH_Three
MM-46: R⁴³, R⁴⁴, R⁴⁵: -O- (CH₂)₆-O-CO-CH = CH₂; R⁵⁴, R⁶⁴: -O- (CH₂)₁₁-CH_Three
(註) Undefined R: unsubstituted (hydrogen atom)
p-Ph: p-phenylene
[0091]
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[0092]

[0093]
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[0094]

[0095]
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[0096]
MM-72: R⁴¹, R⁴³, R⁴⁵: -CH_Three
MM-73: R⁴¹, R⁴³, R⁴⁵: -C₂H_Five
MM-74: R⁴¹, R⁴³: -C₂H_Five; R⁴⁵: -CH_Three
MM-75: R⁴¹, R⁴³, R⁴⁵:-( CH₂)_Three-CH_Three
[0097]
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[0098]
MM-76: R⁴², R⁴⁴, R⁴⁶:-( CH₂)₉-O-CO-CH = CH₂
MM-77: R⁴², R⁴⁴, R⁴⁶:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
MM-78: R⁴², R⁴⁴:-( CH₂)₉-O-CO-CH = CH₂; R⁴⁶:-( CH₂)₁₂-CH_Three
MM-79: R⁴², R⁴⁴:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R⁴⁶:-( CH₂)₁₂-CH_Three
MM-80: R⁴²:-( CH₂)₉-O-CO-CH = CH₂; R⁴⁴, R⁴⁶:-( CH₂)₁₂-CH_Three
MM-81: R⁴²:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R⁴⁴, R⁴⁶:-( CH₂)₁₂-CH_Three
MM-82: R⁴², R⁴⁴:-( CH₂)_Four-O-CO-CH = CH₂; R⁴⁶:-( CH₂)₁₂-CH_Three
MM-83: R⁴²:-( CH₂)_Four-O-CO-CH = CH₂; R⁴⁴, R⁴⁶:-( CH₂)₁₂-CH_Three
MM-84: R⁴², R⁴⁴, R⁴⁶:-( CH₂)₉-O-EpEt
MM-85: R⁴², R⁴⁴, R⁴⁶:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-EpEt
MM-86: R⁴², R⁴⁴:-( CH₂)₉-O-EpEt; R⁴⁶:-( CH₂)₁₂-CH_Three
MM-87: R⁴², R⁴⁴, R⁴⁶:-( CH₂)₉-O-CH = CH₂
MM-88: R⁴², R⁴⁴:-( CH₂)₉-O-CH = CH₂; R⁴⁶:-( CH₂)₁₂-CH_Three
(Ii) EpEt: Epoxyethyl
[0099]
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[0100]
MM-89: R⁴¹, R⁴², R⁴³, R⁴⁴, R⁴⁵, R⁴⁶:-( CH₂)₉-CH_Three
MM-90: R⁴¹, R⁴³, R⁴⁵: -CH_Three; R⁴², R⁴⁴, R⁴⁶:-( CH₂)₁₇-CH_Three
MM-91: R⁴¹, R⁴², R⁴³, R⁴⁴:-( CH₂)₇-CH_Three; R⁴⁵, R⁴⁶:-( CH₂)_Five-CH_Three
MM-92: R⁴¹, R⁴², R⁴³, R⁴⁴, R⁴⁵, R⁴⁶: -CyHx
MM-93: R⁴¹, R⁴², R⁴³, R⁴⁴, R⁴⁵, R⁴⁶:-( CH₂)₂-O-C₂H_Five
MM-94: R⁴¹, R⁴³, R⁴⁵: -CH_Three; R⁴², R⁴⁴, R⁴⁶:-( CH₂)₁₂-O-CO-CH = CH₂
MM-95: R⁴¹, R⁴², R⁴³, R⁴⁴, R⁴⁵, R⁴⁶:-( CH₂)₈-O-CO-CH = CH₂
(Ii) CyHx: Cyclohexyl
[0101]
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[0102]
A melamine polymer may be used as the melamine compound. The melamine polymer is preferably synthesized by a polymerization reaction between a melamine compound represented by the following formula (V) and a carbonyl compound.
[0103]
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[0104]
Where R⁷¹, R⁷², R⁷³, R⁷⁴, R⁷⁵And R⁷⁶Are each independently a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or a heterocyclic group.
The definitions and substituents of the alkyl group, alkenyl group, aryl group and heterocyclic group are the same as the definitions and substituents of each group described in the formula (III).
The polymerization reaction between the melamine compound and the carbonyl compound is the same as the method for synthesizing a normal melamine resin (eg, melamine formaldehyde resin). A commercially available melamine polymer (melamine resin) may be used.
The molecular weight of the melamine polymer is preferably 2,000 or more and 400,000 or less.
[0105]
R⁷¹, R⁷², R⁷³, R⁷⁴, R⁷⁵And R⁷⁶Preferably, at least one of these includes an alkylene or alkenylene moiety having 9 to 30 carbon atoms. The alkylene or alkenylene moiety having 9 to 30 carbon atoms is preferably linear. The alkylene moiety or alkenylene moiety is preferably contained in the substituent of the aryl group.
R⁷¹, R⁷², R⁷³, R⁷⁴, R⁷⁵And R⁷⁶At least one of these preferably has a polymerizable group as a substituent. The polymerizable group is R⁷¹, R⁷², R⁷³, R⁷⁴, R⁷⁵And R⁷⁶It is preferable that it is located at the terminal of.
By introducing a polymerizable group into the melamine polymer, it can be contained in the optically anisotropic layer in a state where the melamine polymer and the discotic liquid crystalline molecule are polymerized.
R having a polymerizable group as a substituent⁷¹, R⁷², R⁷³, R⁷⁴, R⁷⁵And R⁷⁶Is the same as the group represented by the aforementioned formula (Rp).
The polymerizable group is a carbonyl compound (R⁷¹, R⁷²) And melamine compounds (R)⁷³, R⁷⁴, R⁷⁵, R⁷⁶). When the melamine compound has a polymerizable group, the carbonyl compound is preferably a compound having a simple chemical structure such as formaldehyde. When the carbonyl compound has a polymerizable group, a compound having a simple chemical structure such as (unsubstituted) melamine is preferably used as the melamine compound.
[0106]
Examples of carbonyl compounds having a polymerizable group are shown below.
[0107]
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[0108]
CO-1: R⁷²: -H; R⁸²: -O- (CH₂)₉-O-CO-CH = CH₂
CO-2: R⁷²: -H; R⁸¹, R⁸²: -O- (CH₂)₉-O-CO-CH = CH₂
CO-3: R⁷²: -H; R⁸²: -O- (CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
CO-4: R⁷²: -H; R⁸¹, R⁸²: -O- (CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
CO-5: R⁷²: -H; R⁸¹, R⁸³: -O- (CH₂)₉-O-CO-CH = CH₂
CO-6: R⁷²: -H; R⁸¹, R⁸², R⁸³: -O- (CH₂)₉-O-CO-CH = CH₂
CO-7: R⁷²: -CH_Three; R⁸²: -O- (CH₂)₉-O-CO-CH = CH₂
CO-8: R⁷²:-( CH₂)₁₁-CH_Three; R⁸²: -O- (CH₂)_Four-O-CO-CH = CH₂
CO-9: R⁷²:-( CH₂)₉-O-CO-CH = CH₂; R⁸²: -O- (CH₂)_Four-O-CO-CH = CH₂
CO-10: R⁷²:-( CH₂)₉-O-CO-EpEt; R⁸²: -O- (CH₂)_Four-O-CO-CH = CH₂
CO-11: R⁷²:-( CH₂)_Four-O-CO-CH = CH₂; R⁸¹, R⁸³: -O- (CH₂)₁₂-CH_Three
(註) Undefined R: unsubstituted (hydrogen atom)
EpEt: Epoxy ethyl
[0109]
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[0110]
CO-12: R⁸¹, R⁸², R⁸³, R⁸⁴: -O- (CH₂)₆-O-CO-CH = CH₂
CO-13: R⁸², R⁸³: -O- (CH₂)₉-O-CO-CH = CH₂
(註) Undefined R: unsubstituted (hydrogen atom)
[0111]
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[0112]
CO-14: R⁷¹:-( CH₂)₉-O-CO-CH = CH₂; R⁷²: -H
CO-15: R⁷¹:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R⁷²: -H
CO-16: R⁷¹:-( CH₂)₉-O-CO-CH = CH₂; R⁷²: -CH_Three
CO-17: R⁷¹:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R⁷²: -CH_Three
CO-18: R⁷¹:-( CH₂)₉-O-CO-CH = CH₂; R⁷²: -Ph
CO-19: R⁷¹:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂; R⁷²: -Ph
CO-20: R⁷¹:-( CH₂)_Four-O-CO-CH = CH₂; R⁷²:-( CH₂)₉-O-CO-CH = CH₂
CO-21: R⁷¹:-( CH₂)_Four-O-CO-CH = CH₂; R⁷²:-( CH₂)₁₂-CH_Three
CO-22: R⁷¹:-( CH₂)₉-O-EpEt; R⁷²: -H
CO-23: R⁷¹:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-EpEt; R⁷²: -H
CO-24: R⁷¹, R⁷²:-( CH₂)₉-O-EpEt
CO-25: R⁷¹, R⁷²:-( CH₂)₉-O-CO-CH = CH₂
CO-26: R⁷¹, R⁷²:-( CH₂)_Four-CH = CH- (CH₂)_Four-O-CO-CH = CH₂
(註) Ph: Phenyl
EpEt: Epoxy ethyl
[0113]
Examples of melamine polymers having a polymerizable group on the melamine compound side are shown below.
[0114]
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[0115]

[0116]
Two or more kinds of compounds having 1,3,5-triazine ring (including melamine compounds and melamine polymers) may be used in combination.
The compound having a 1,3,5-triazine ring is preferably used in an amount of 0.01 to 20% by weight, and preferably in an amount of 0.1 to 15% by weight of the amount of the discotic liquid crystalline molecule. More preferably, it is most preferably used in an amount of 0.5 to 10% by weight.
The coating amount of the compound having a 1,3,5-triazine ring is 1 to 1000 mg / m.²Is preferably in the range of 2 to 300 mg / m²Is more preferably in the range of 3 to 100 mg / m²Most preferably, it is in the range.
[0117]
The optically anisotropic layer is composed of discotic liquid crystalline molecules or the following polymerizable initiators and optional additives (eg, plasticizer, monomer, surfactant, cellulose ester, 1,3,5-triazine compound, chiral agent). ) Containing a liquid crystal composition (coating liquid).
As the solvent used for preparing the liquid crystal composition, an organic solvent is preferably used. Examples of organic solvents include amides (eg, N, N-dimethylformamide), sulfoxides (eg, dimethyl sulfoxide), heterocyclic compounds (eg, pyridine), hydrocarbons (eg, benzene, hexane), alkyl halides (eg, , Chloroform, dichloromethane), esters (eg, methyl acetate, butyl acetate), ketones (eg, acetone, methyl ethyl ketone), ethers (eg, tetrahydrofuran, 1,2-dimethoxyethane). Alkyl halides and ketones are preferred. Two or more organic solvents may be used in combination.
The liquid crystal composition can be applied by a known method (eg, wire bar coating method, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).
[0118]
The polymerization reaction of the discotic liquid crystalline molecule includes a thermal polymerization reaction using a thermal polymerization initiator and a photopolymerization reaction using a photopolymerization initiator. A photopolymerization reaction is preferred.
Examples of the photopolymerization initiator include α-carbonyl compounds (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substituted aromatic acyloin. Compound (described in US Pat. No. 2,722,512), polynuclear quinone compound (described in US Pat. Nos. 3,046,127 and 2,951,758), a combination of triarylimidazole dimer and p-aminophenyl ketone (US Pat. No. 3,549,367) Acridine and phenazine compounds (JP-A-60-105667, U.S. Pat. No. 4,239,850) and oxadiazole compounds (U.S. Pat. No. 4,212,970).
The amount of the photopolymerization initiator used is preferably 0.01 to 20% by weight, more preferably 0.5 to 5% by weight, based on the solid content of the coating solution.
Light irradiation for polymerization of discotic liquid crystalline molecules is preferably performed using ultraviolet rays.
Irradiation energy is 20mJ / cm² ~ 50J / cm² Preferably, 100 to 800 mJ / cm² More preferably. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions.
The thickness of the optically anisotropic layer is preferably 0.1 to 20 μm, more preferably 0.5 to 15 μm, and most preferably 1 to 10 μm.
[0119]
[Polarizing film]
Examples of the polarizing film include an iodine polarizing film, a dye polarizing film using a dichroic dye, and a polyene polarizing film. The iodine polarizing film and the dye polarizing film are generally manufactured using a polyvinyl alcohol film. The polarization axis of the polarizing film corresponds to a direction perpendicular to the film stretching direction.
The transmission axis in the plane of the polarizing film is preferably arranged so as to be substantially parallel or orthogonal to the slow axis of the transparent support.
[0120]
[Transparent protective film]
A transparent polymer film is used as the transparent protective film. That the protective film is transparent means that the light transmittance is 80% or more.
As the transparent protective film, generally a cellulose ester film, preferably a triacetyl cellulose film is used. The cellulose ester film is preferably formed by a solvent cast method.
The thickness of the transparent protective film is preferably 20 to 500 μm, and more preferably 50 to 200 μm.
[0121]
[Liquid Crystal Display]
The present invention can be applied to liquid crystal cells in various display modes. As described above, optical compensation sheets using liquid crystalline molecules are TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (Optically Compensatory Bend), STN (Supper Twisted Nematic). A liquid crystal cell corresponding to a liquid crystal cell of VA (Vertically Aligned), ECB (Electrically Controlled Birefringence) and HAN (Hybrid Aligned Nematic) modes has already been proposed. INDUSTRIAL APPLICABILITY The present invention is effective in a liquid crystal display device using a liquid crystal cell such as a VA mode, an OCB mode, and a HAN mode in which many rod-like liquid crystal molecules are aligned substantially vertically, and most rod-like liquid crystal molecules. This is particularly effective in a VA mode liquid crystal display device in which is substantially vertically aligned.
The VA mode liquid crystal cell includes (1) a narrowly defined VA mode liquid crystal cell in which rod-like liquid crystalline molecules are aligned substantially vertically when no voltage is applied, and substantially horizontally when a voltage is applied (Japanese Patent Laid-Open No. Hei 2- 176625) (2) Liquid crystal cell (SID97, Digest of tech. Papers (Preliminary Proceed) 28 (1997) 845 in which the VA mode is converted into a multi-domain (MVA mode) for widening the viewing angle ), (3) A liquid crystal cell in a mode (n-ASM mode) in which rod-like liquid crystalline molecules are substantially vertically aligned when no voltage is applied and twisted multi-domain alignment is applied when a voltage is applied (Preliminary collections 58-59 of the Japan Liquid Crystal Society) (1998)) and (4) SURVAVAL mode liquid crystal cells (announced at LCD International 98).
[0122]
【Example】
[Example 1]
(Production of optical compensation sheet)
Cellulose diacetate was applied to one surface of the cellulose triacetate film and dried to form an undercoat layer (an alignment film not subjected to rubbing treatment) having a dry film thickness of 0.5 μm.
90 parts by weight of the following discotic liquid crystalline molecules (1), 10 parts by weight of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), melamine formaldehyde / acrylic acid copolymer (Aldrich reagent) 0 .6 parts by weight, 3.0 parts by weight of photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Japan) and 1.0 part by weight of photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) To obtain a coating solution having a solid content concentration of 38% by weight.
[0123]
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[0124]
The coating solution was applied on the undercoat layer and dried. The discotic liquid crystalline molecules were aligned by heating at 130 ° C. for 2 minutes. Immediately cool to room temperature, 500 mJ / cm²The ultraviolet rays were irradiated to polymerize the discotic liquid crystalline molecules, and the alignment state was fixed. The thickness of the formed optically anisotropic layer was 1.7 μm.
The angle dependency of retardation of the optically anisotropic layer was measured with an ellipsometer (manufactured by JASCO Corporation). As a result, the average tilt angle of the discotic liquid crystal molecules was 0.2 °, and the retardation (Rth) in the thickness direction was 88 nm.
[0125]
An optical compensation sheet was prepared by bonding a polycarbonate film having optical uniaxiality to the other surface of the cellulose triacetate film using an adhesive.
The polycarbonate film having optical uniaxial property has an optical axis in the plane, the in-plane retardation (Re) is 50 nm, and the retardation in the thickness direction is nm.
The entire optical compensation sheet produced had an in-plane retardation (Re) of 50 nm and a thickness direction retardation (Rth) of 100 nm.
[0126]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support (polycarbonate film) side of the optical compensation sheet to prepare an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0127]
(Production of liquid crystal display device)
The elliptically polarizing plate was deleted from the commercially available VA liquid crystal display device (LCD5000), and the produced elliptically polarizing plate was attached instead.
When the contrast data in all directions was measured for the manufactured VA liquid crystal display device, the viewing angle at which a contrast ratio of 20: 1 was obtained was 160 ° in the vertical and horizontal directions. On the other hand, in a commercially available VA liquid crystal display device (LCD 5000), the viewing angle at which a contrast ratio of 20: 1 was obtained was 120 ° vertically and horizontally.
[0128]
[Example 2]
(Production of optical biaxial transparent support)
87 parts by weight of cellulose triacetate, 10 parts by weight of triphenyl phosphate and 3 parts by weight of an ultraviolet absorber (TM165, manufactured by Sumitomo Chemical Co., Ltd.) were dissolved in methylene chloride to prepare a solution having a solid content concentration of 18% by weight. . The solution was cast on a glass plate and dried at 40 ° C. for 20 minutes. The formed film (thickness: 100 μm) was peeled from the glass plate.
The produced cellulose triacetate film was 20 Kg / mm for 10 minutes at 145 ° C.²The stress was applied. Thus, an optical biaxial transparent support having an in-plane retardation (Re) of 20 nm and a thickness direction retardation (Rth) of 80 nm was produced.
[0129]
(Production of optical compensation sheet)
The coating solution for the optically anisotropic layer used in Example 1 was placed on an optical biaxial transparent support at 3 ml / m.²It was applied and dried at room temperature. By heating at 130 ° C. for 1 minute, the discotic liquid crystalline molecules were aligned, irradiated with ultraviolet rays, the discotic liquid crystalline molecules were polymerized, and the alignment state was fixed.
The angle dependence of retardation of the optically anisotropic layer was measured with an ellipsometer (manufactured by JASCO Corporation). As a result, the average tilt angle of the discotic liquid crystal molecules was 0.1 °.
The entire optical compensation sheet produced had an in-plane retardation (Re) of 20 nm and a thickness direction retardation (Rth) of 140 nm.
[0130]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support side of the optical compensation sheet to produce an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0131]
(Production of liquid crystal display device)
The elliptically polarizing plate was deleted from the commercially available VA liquid crystal display device (LCD5000), and the produced elliptically polarizing plate was attached instead.
When the contrast data in all directions was measured for the manufactured VA liquid crystal display device, the viewing angle at which a contrast ratio of 20: 1 was obtained was 160 ° in the vertical and horizontal directions.
[0132]
[Example 3]
(Production of optical biaxial transparent support)
85 parts by weight of cellulose triacetate, 10 parts by weight of triphenyl phosphate and 5 parts by weight of an ultraviolet absorber (TM165, manufactured by Sumitomo Chemical Co., Ltd.) were dissolved in methylene chloride to prepare a solution having a solid content concentration of 18% by weight. . The solution was cast on a glass plate and dried at 40 ° C. for 20 minutes. The formed film (thickness: 100 μm) was peeled from the glass plate.
The produced cellulose triacetate film was 20 Kg / mm for 10 minutes at 145 ° C.²The stress was applied. Thus, an optical biaxial transparent support having an in-plane retardation (Re) of 50 nm and a thickness direction retardation (Rth) of 120 nm was produced.
[0133]
(Production of optical compensation sheet)
The coating solution for the optically anisotropic layer used in Example 1 was placed on an optical biaxial transparent support at 6 ml / m.²It was applied and dried at room temperature. By heating at 130 ° C. for 1 minute, the discotic liquid crystalline molecules were aligned, irradiated with ultraviolet rays, the discotic liquid crystalline molecules were polymerized, and the alignment state was fixed.
The angle dependence of retardation of the optically anisotropic layer was measured with an ellipsometer (manufactured by JASCO Corporation). As a result, the average tilt angle of the discotic liquid crystal molecules was 0.5 °.
The entire optical compensation sheet produced had an in-plane retardation (Re) of 50 nm and a thickness direction retardation (Rth) of 250 nm.
[0134]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support side of the optical compensation sheet to produce an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0135]
(Production of liquid crystal display device)
The elliptically polarizing plate was deleted from the commercially available VA liquid crystal display device (LCD5000), and the produced elliptically polarizing plate was attached instead.
When the contrast data in all directions was measured for the manufactured VA liquid crystal display device, the viewing angle at which a contrast ratio of 20: 1 was obtained was 160 ° in the vertical and horizontal directions.
[0136]
[Example 4]
(Production of optical biaxial transparent support)
45 parts by weight of cellulose acetate having an average degree of acetylation of 60.9%, 2.35 parts by weight of the following retardation increasing agent, 2.75 parts by weight of triphenyl phosphate and 2.20 parts by weight of biphenyl diphenyl phosphate were mixed with methylene chloride. It melt | dissolved in 232.75 weight part, methanol 42.57 weight part, and n-butanol 8.50 weight part. The obtained solution was cast using a drum casting machine to produce a cellulose acetate film having a thickness of 105 μm after drying.
[0137]
Embedded image

[0138]
The cellulose acetate film was stretched at a substantial stretch ratio of 20% to produce an optical biaxial transparent support.
The retardation of the transparent support at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the thickness direction retardation (Rth) was 85 nm, and the in-plane retardation (Re) was 40 nm.
[0139]
(Production of optical compensation sheet)
Gelatin was coated on one side of the transparent support to form an undercoat layer.
On the undercoat layer, an aqueous solution of 2% by weight of the modified polyvinyl alcohol and 0.1% by weight of glutaraldehyde described below was applied and dried to form an alignment film having a thickness of 0.5 μm.
[0140]
Embedded image

[0141]
90 parts by weight of the discotic liquid crystalline molecule (1) used in Example 1, 10 parts by weight of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), melamine formaldehyde / acrylic acid copolymer ( Aldrich reagent) 0.6 parts by weight, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Japan, Inc.) 3.0 parts by weight and photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 weight A part was dissolved in 170 parts by weight of methyl ethyl ketone to prepare a coating solution.
The coating solution was applied on the alignment film and dried. The discotic liquid crystalline molecules were aligned by heating at 130 ° C. for 1 minute. Further, ultraviolet rays were irradiated to polymerize the discotic liquid crystalline molecules, and the alignment state was fixed. The thickness of the formed optically anisotropic layer was 1.2 μm.
The retardation of the entire optical compensation sheet at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the in-plane retardation (Re) was 40 m and the thickness direction retardation (Rth) was 160 nm.
[0142]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support side of the optical compensation sheet to produce an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0143]
(Production of liquid crystal display device)
The polarizing plate was deleted from a commercially available MVA liquid crystal display device (VL-1530S, manufactured by Fujitsu Limited), and an elliptically polarizing plate produced instead was attached.
With respect to the manufactured MVA liquid crystal display device, a viewing angle at which a contrast ratio of 10: 1 was obtained without image inversion was measured. The results are shown in Table 1.
[0144]
[Example 5]
(Production of optical biaxial transparent support)
30 parts by weight of norbornene resin (Arton, manufactured by JSR Corporation) was dissolved in 70 parts by weight of methylene chloride. The obtained solution was cast using a band casting machine to produce a norbornene film having a thickness after drying of 100 μm.
The norbornene film was stretched in the longitudinal direction at a substantial stretching ratio of 15%, and further stretched in the width direction at a substantial stretching ratio of 7% to produce an optical biaxial transparent support.
The retardation of the transparent support at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the thickness direction retardation (Rth) was 45 nm, and the in-plane retardation (Re) was 40 nm.
[0145]
(Production of optical compensation sheet)
One side of the transparent support was subjected to corona discharge treatment.
On the surface subjected to the corona discharge treatment, an aqueous solution containing 2% by weight of modified polyvinyl alcohol and 0.1% by weight of glutaraldehyde used in Example 4 was applied and dried to form an alignment film having a thickness of 0.5 μm.
90 parts by weight of the discotic liquid crystalline molecule (1) used in Example 1, 10 parts by weight of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), melamine formaldehyde / acrylic acid copolymer ( Aldrich reagent) 0.6 parts by weight, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Japan, Inc.) 3.0 parts by weight and photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 weight A part was dissolved in 170 parts by weight of methyl ethyl ketone to prepare a coating solution.
The coating solution was applied on the alignment film and dried. The discotic liquid crystalline molecules were aligned by heating at 130 ° C. for 1 minute. Further, ultraviolet rays were irradiated to polymerize the discotic liquid crystalline molecules, and the alignment state was fixed. The thickness of the formed optically anisotropic layer was 1.4 μm.
The retardation of the entire optical compensation sheet at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the in-plane retardation (Re) was 30 m and the thickness direction retardation (Rth) was 120 nm.
[0146]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support side of the optical compensation sheet to produce an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0147]
(Production of liquid crystal display device)
The polarizing plate was deleted from a commercially available MVA liquid crystal display device (VL-1530S, manufactured by Fujitsu Limited), and an elliptically polarizing plate produced instead was attached.
With respect to the manufactured MVA liquid crystal display device, a viewing angle at which a contrast ratio of 10: 1 was obtained without image inversion was measured. The results are shown in Table 1.
[0148]
[Example 6]
(Production of optical biaxial transparent support)
A commercially available polycarbonate film (manufactured by Teijin Ltd.) was stretched in the longitudinal direction at a substantial stretch ratio of 40%, and further stretched in the width direction at a substantial stretch ratio of 15% to produce an optical biaxial transparent support.
The retardation of the transparent support at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the thickness direction retardation (Rth) was 100 nm, and the in-plane retardation (Re) was 200 nm.
[0149]
(Production of optical compensation sheet)
One side of the transparent support was subjected to corona discharge treatment.
On the surface subjected to the corona discharge treatment, an aqueous solution containing 2% by weight of modified polyvinyl alcohol and 0.1% by weight of glutaraldehyde used in Example 4 was applied and dried to form an alignment film having a thickness of 0.5 μm.
90 parts by weight of the discotic liquid crystalline molecule (1) used in Example 1, 10 parts by weight of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), melamine formaldehyde / acrylic acid copolymer ( Aldrich reagent) 0.6 parts by weight, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Japan, Inc.) 3.0 parts by weight and photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 weight A part was dissolved in 170 parts by weight of methyl ethyl ketone to prepare a coating solution.
The coating solution was applied on the alignment film and dried. The discotic liquid crystalline molecules were aligned by heating at 130 ° C. for 1 minute. Further, ultraviolet rays were irradiated to polymerize the discotic liquid crystalline molecules, and the alignment state was fixed. The thickness of the formed optically anisotropic layer was 3.5 μm.
The retardation of the entire optical compensation sheet at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the in-plane retardation (Re) was 200 m, and the thickness direction retardation (Rth) was 300 nm.
[0150]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support side of the optical compensation sheet to produce an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0151]
(Production of liquid crystal display device)
The polarizing plate was deleted from a commercially available MVA liquid crystal display device (VL-1530S, manufactured by Fujitsu Limited), and an elliptically polarizing plate produced instead was attached.
With respect to the manufactured MVA liquid crystal display device, a viewing angle at which a contrast ratio of 10: 1 was obtained without image inversion was measured. The results are shown in Table 1.
[0152]
[Comparative Example 1]
(Production of optically isotropic transparent support)
A commercially available cellulose triacetate film (Fuji Photo Film Co., Ltd.) was used as a transparent support.
The retardation of the transparent support at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the retardation (Rth) in the thickness direction was 40 nm and the in-plane retardation (Re) was 3 nm, which was substantially optically isotropic.
[0153]
(Production of optical compensation sheet)
Gelatin was coated on one side of the transparent support to form an undercoat layer.
On the undercoat layer, an aqueous solution of 2% by weight of modified polyvinyl alcohol and 0.1% by weight of glutaraldehyde used in Example 4 was applied and dried to form an alignment film having a thickness of 0.5 μm.
90 parts by weight of the discotic liquid crystalline molecule (1) used in Example 1, 10 parts by weight of ethylene oxide-modified trimethylolpropane triacrylate (V # 360, manufactured by Osaka Organic Chemical Co., Ltd.), melamine formaldehyde / acrylic acid copolymer ( Aldrich reagent) 0.6 parts by weight, photopolymerization initiator (Irgacure 907, manufactured by Ciba Geigy Japan, Inc.) 3.0 parts by weight and photosensitizer (Kayacure DETX, manufactured by Nippon Kayaku Co., Ltd.) 1.0 weight A part was dissolved in 170 parts by weight of methyl ethyl ketone to prepare a coating solution.
The coating solution was applied on the alignment film and dried. The discotic liquid crystalline molecules were aligned by heating at 130 ° C. for 1 minute. Further, ultraviolet rays were irradiated to polymerize the discotic liquid crystalline molecules, and the alignment state was fixed. The thickness of the formed optically anisotropic layer was 2.0 μm.
The retardation of the entire optical compensation sheet at a wavelength of 633 nm was measured with an ellipsometer (M150, manufactured by JASCO Corporation). As a result, the in-plane retardation (Re) was 3 m and the thickness direction retardation (Rth) was 240 nm.
[0154]
(Production of elliptically polarizing plate)
A polarizing film and a transparent protective film were laminated in this order on the transparent support side of the optical compensation sheet to produce an elliptically polarizing plate.
The slow axis of the transparent support and the polarization axis of the polarizing film were arranged in parallel.
[0155]
(Production of liquid crystal display device)
The polarizing plate was deleted from a commercially available MVA liquid crystal display device (VL-1530S, manufactured by Fujitsu Limited), and an elliptically polarizing plate produced instead was attached.
With respect to the manufactured MVA liquid crystal display device, a viewing angle at which a contrast ratio of 10: 1 was obtained without image inversion was measured. The results are shown in Table 1.
[0156]
[Reference Example 1]
With respect to a commercially available MVA liquid crystal display device (VL-1530S, manufactured by Fujitsu Limited), the viewing angle at which a contrast ratio of 10: 1 was obtained without image inversion was measured. The results are shown in Table 1.
[0157]
[Table 1]

[Brief description of the drawings]
FIG. 1 is a schematic diagram showing a basic configuration of a transmissive liquid crystal display device.
FIG. 2 is a schematic diagram showing a basic configuration of a reflective liquid crystal display device.
[Explanation of symbols]
BR backlight
RP reflector
1, 1a, 1b, 1c Transparent protective film
2, 2a, 2b Polarizing film
3, 3a, 3b transparent support
4, 4a, 4b Optically anisotropic layer
5a Lower substrate of liquid crystal cell
5b Upper substrate of liquid crystal cell
6 Rod-like liquid crystalline molecules

Claims (11)

An optical compensation sheet having an optically anisotropic layer formed from a transparent support and discotic liquid crystalline molecules, wherein the optically anisotropic layer further comprises a compound having a 1,3,5-triazine ring as a discotic liquid crystalline The transparent support has optical uniaxial or optical biaxiality, and is between the disc surface of the discotic liquid crystalline molecule and the transparent support surface. An optical compensation sheet, wherein the discotic liquid crystalline molecules are oriented with an average tilt angle of less than 5 °. The optical compensation sheet according to claim 1, wherein the compound having a 1,3,5-triazine ring is a melamine compound . The optical compensation sheet according to claim 2, wherein the melamine compound is a melamine polymer . The optical compensation sheet according to claim 1, wherein the transparent support comprises a polymer film that has been subjected to an unbalanced biaxial stretching treatment . 5. In the unbalanced biaxial stretching process, the polymer film is stretched in a certain direction at a magnification in the range of 3 to 100%, and further stretched in a direction perpendicular thereto at a magnification in the range of 6 to 200%. The optical compensation sheet according to 1 . The optical compensation sheet according to claim 1, wherein the transparent support has an in-plane retardation (Re) defined by the following formula in a range of 10 to 1000 nm.
Re = (nx−ny) × d
[Wherein nx and ny are the in-plane refractive indices of the transparent support and d is the thickness of the transparent support] . The optical compensation sheet according to claim 1, wherein the transparent support has a thickness direction retardation (R th ) defined by the following formula in a range of 10 to 1000 nm .
R th = [{(nx + ny) / 2} −nz] × d
[Wherein nx and ny are in-plane refractive indices of the transparent support, nz is the refractive index in the thickness direction of the transparent support, and d is the thickness of the transparent support] . The optical compensation sheet according to claim 1, wherein the optical compensation sheet has an in-plane retardation (Re) defined by the following formula in a range of 20 to 200 nm.
  Re = (nx−ny) × d
[Wherein nx and ny are the in-plane refractive indices of the optical compensation sheet and d is the thickness of the optical compensation sheet]. The optical compensation sheet has a thickness direction retardation (R) defined by the following formula in the range of 70 to 500 nm. th The optical compensation sheet according to claim 1, comprising:
  R th = [{(Nx + ny) / 2} -nz] × d
[Where nx and ny are the in-plane refractive indices of the optical compensation sheet, nz is the refractive index in the thickness direction of the optical compensation sheet, and d is the thickness of the optical compensation sheet]. An elliptically polarizing plate having a transparent support, an optically anisotropic layer formed from discotic liquid crystalline molecules, a polarizing film and a transparent protective film, wherein the optically anisotropic layer further has a 1,3,5-triazine ring. The transparent substrate has optical uniaxial or optical biaxiality, the disc surface of the discotic liquid crystalline molecule, An elliptically polarizing plate characterized in that discotic liquid crystal molecules are oriented with an average inclination angle to the transparent support surface of less than 5 °. A liquid crystal display device comprising a VA mode liquid crystal cell and two polarizing elements disposed on both sides thereof, wherein at least one of the polarizing elements is formed of a transparent support and a discotic liquid crystalline molecule. An elliptically polarizing plate having a layer, a polarizing film and a transparent protective film, wherein the optically anisotropic layer further comprises a compound having a 1,3,5-triazine ring in an amount of 0.01 to 20% by weight of the amount of discotic liquid crystalline molecules The transparent support has optical uniaxial or optical biaxiality, and the average tilt angle between the disc surface of the discotic liquid crystalline molecules and the transparent support surface is less than 5 ° A liquid crystal display device characterized in that discotic liquid crystalline molecules are aligned.

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