JP2004145071A - Optical retardation plate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method in which an optical retardation plate having high adhesive strength between an alignment film and an optical anisotropic layer and superior weatherability can easily be manufactured. <P>SOLUTION: The manufacturing method for the optical retardation plate having a transparent support, the alignment film formed of a polymer having a polymerizable group, and at least one optical anisotropic layer where a photosetting rod-type liquid crystal compound is fixed by polymerization in a state wherein it is aligned substantially horizontally to the alignment film surface includes a high-temperature light irradiating process of light irradiation within a temperature range of 60 to 130°C. <P>COPYRIGHT: (C)2004,JPO

Description

【００２９】
前記式（Ｉ）中、Ｌ^１およびＬ^４はそれぞれ独立に二価の連結基である。Ｌ^１およびＬ^４はそれぞれ独立に、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ^２−、二価の鎖状基、二価の環状基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。上記Ｒ^２は炭素原子数が１〜７のアルキル基または水素原子である。
【００３０】
組み合わせからなる二価の連結基の例を以下に示す。ここで、左側がＱ（Ｑ^１またはＱ^２）に、右側がＣｙ（Ｃｙ^１またはＣｙ^３）に結合する。
Ｌ−１：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−
Ｌ−２：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−
Ｌ−３：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−
Ｌ−４：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−二価の環状基−
Ｌ−５：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−二価の環状基−ＣＯ−Ｏ−
Ｌ−６：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−二価の環状基−Ｏ−ＣＯ−
Ｌ−７：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−二価の環状基−二価の鎖状基−
Ｌ−８：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−二価の環状基−二価の鎖状基−ＣＯ−Ｏ−
Ｌ−９：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−二価の環状基−二価の鎖状基−Ｏ−ＣＯ−
【００３１】
Ｌ−１０：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−二価の環状基−
Ｌ−１１：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−二価の環状基−ＣＯ−Ｏ−
Ｌ−１２：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−二価の環状基−Ｏ−ＣＯ−
Ｌ−１３：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−二価の環状基−二価の鎖状基−
Ｌ−１４：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−二価の環状基−二価の鎖状基−ＣＯ−Ｏ−
Ｌ−１５：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−二価の環状基−二価の鎖状基−Ｏ−ＣＯ−
Ｌ−１６：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−二価の環状基−
Ｌ−１７：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−二価の環状基−ＣＯ−Ｏ−
Ｌ−１８：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−二価の環状基−Ｏ−ＣＯ−
Ｌ−１９：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−二価の環状基−二価の鎖状基−
Ｌ−２０：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−二価の環状基−二価の鎖状基−ＣＯ−Ｏ−
Ｌ−２１：−ＣＯ−Ｏ−二価の鎖状基−Ｏ−ＣＯ−Ｏ−二価の環状基−二価の鎖状基−Ｏ−ＣＯ−
【００３２】
前記式中、二価の鎖状基は、アルキレン基、置換アルキレン基、アルケニレン基、置換アルケニレン基、アルキニレン基または置換アルキニレン基を意味する。アルキレン基、置換アルキレン基、アルケニレン基、置換アルケニレン基が好ましく、アルキレン基およびアルケニレン基がさらに好ましい。
アルキレン基は、分岐を有していてもよい。アルキレン基の炭素数は１〜１２であることが好ましく、２〜１０であることがさらに好ましく、２〜８であることがもっとも好ましい。
置換アルキレン基のアルキレン部分は、上記アルキレン基と同様である。置換基の例としてはハロゲン原子が含まれる。
アルケニレン基は、分岐を有していてもよい。アルケニレン基の炭素数は２〜１２であることが好ましく、２〜１０であることがさらに好ましく、２〜８であることがもっとも好ましい。
置換アルキレン基のアルキレン部分は、上記アルキレン基と同様である。置換基の例としてはハロゲン原子が含まれる。
アルキニレン基は、分岐を有していてもよい。アルキニレン基の炭素数は２〜１２であることが好ましく、２〜１０であることがさらに好ましく、２〜８であることがもっとも好ましい。
置換アルキニレン基のアルキニレン部分は、上記アルキニレン基と同様である。置換基の例としてはハロゲン原子が含まれる。
二価の鎖状基の具体例としては、エチレン、トリメチレン、プロピレン、ブタメチレン、１−メチル−ブタメチレン、ペンタメチレン、ヘキサメチレン、オクタメチレン、２−ブテニレン、２−ブチニレンなどが上げられる。
【００３３】
二価の環状基の定義および例は、後述するＣｙ^１、Ｃｙ^２およびＣｙ^３の定義および例と同様である。
Ｒ^２は、炭素原子数１から４のアルキル基または水素原子であることが好ましく、メチル基、エチ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もっとも好ましい。
【００３４】
Ｌ^２またはＬ^３はそれぞれ独立に単結合または二価の連結基である。Ｌ^２およびＬ^３はそれぞれ独立に、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ_２−、二価の鎖状基、二価の環状基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または単結合であることが好ましい。上記Ｒ^２は炭素原子数が１〜７のアルキル基または水素原子であり、炭素原子数１から４のアルキル基または水素原子であることが好ましく、メチル基、エチ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もっとも好ましい。二価の鎖状基、および二価の環状基についてはＬ^１およびＬ^４の定義と同義である。
【００３５】
式（Ｉ）において、ｎは０、１または２である。ｎが２の場合、二つのＬ^３は同じであっても異なっていてもよく、２つのＣｙ^２も同じであっても異なっていてもよい。ｎは１または２であることが好ましく、１であることがさらに好ましい。
【００３６】
式（Ｉ）において、Ｃｙ^１、Ｃｙ^２およびＣｙ^３は、それぞれ独立に、二価の環状基である。
環状基に含まれる環は、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。環状基に含まれる環は、縮合環であってもよい。ただし、縮合環よりも単環であることがより好ましい。環状基に含まれる環は、芳香族環、脂肪族環、および複素環のいずれでもよい。芳香族環の例には、ベンゼン環およびナフタレン環が含まれる。脂肪族環の例には、シクロヘキサン環が含まれる。複素環の例には、ピリジン環およびピリミジン環が含まれる。ベンゼン環を有する環状基としては、１，４−フェニレンが好ましい。ナフタレン環を有する環状基としては、ナフタレン−１，５−ジイルおよびナフタレン−２，６−ジイルが好ましい。シクロヘキサン環を有する環状基としては１，４−シクロへキシレンであることが好ましい。ピリジン環を有する環状基としてはピリジン−２，５−ジイルが好ましい。ピリミジン環を有する環状基としては、ピリミジン−２，５−ジイルが好ましい。
【００３７】
環状基は、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、シアノ基、ニトロ基、炭素原子数が１〜５のアルキル基、炭素原子数が１〜５のハロゲン置換アルキル基、炭素原子数が１〜５のアルコキシ基、炭素原子数が１〜５のアルキルチオ基、炭素原子数が２〜６のアシルオキシ基、炭素原子数が２〜６のアルコキシカルボニル基、カルバモイル基、炭素原子数が２〜６のアルキル置換カルバモイル基および炭素原子数が２〜６のアシルアミノ基が含まれる。
【００３８】
以下に、本発明に使用可能な光硬化型棒状液晶性化合物の具体例を示すが、本発明はこれらによって限定されるものではない。
【００３９】
【化２】

【００４０】
【化３】

【００４１】
【化４】

【００４２】
【化５】

【００４３】
本発明において、光硬化型液晶性化合物として、光硬化型円盤状液晶性化合物を用いることができる。円盤状液晶性化合物は、ポリマーフィルム面に対して実質的に垂直（５０〜９０度の範囲の平均傾斜角）に配向させることが好ましい。円盤状液晶性化合物は、様々な文献（Ｃ．Ｄｅｓｔｒａｄｅ　ｅｔ　ａｌ．，Ｍｏｌ．Ｃｒｙｓｒ．Ｌｉｑ．Ｃｒｙｓｔ．，ｖｏｌ．７１，ｐａｇｅ　１１１（１９８１）；日本化学会編、季刊化学総説、Ｎｏ．２２、液晶の化学、第５章、第１０章第２節（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））に記載されている。円盤状液晶性化合物の重合については、特開平８−２７２８４公報に記載がある。円盤状液晶性化合物を重合により固定するためには、円盤状液晶性化合物の円盤状コアに、置換基として重合性基を結合させる必要がある。ただし、円盤状コアに重合性基を直結させると、重合反応において配向状態を保つことが困難になる。そこで、円盤状コアと重合性基との間に、連結基を導入する。即ち、光硬化型円盤状液晶性化合物は、下記式（ＩＩ）で表わされる化合物であることが好ましい。
式（ＩＩ）
Ｄ（−Ｌ−Ｐ）_ｎ
式中、Ｄは円盤状コアであり、Ｌは二価の連結基であり、Ｐは重合性基であり、ｎは４〜１２の整数である。
【００４４】
前記式（ＩＩ）中の円盤状コア（Ｄ）、二価の連結基（Ｌ）および重合性基（Ｐ）の好ましい具体例は、それぞれ、特開２００１−４８３７号公報に記載の（Ｄ１）〜（Ｄ１５）、（Ｌ１）〜（Ｌ２５）、（Ｐ１）〜（Ｐ１８）であり、同公報に記載の内容を好ましく用いることができる。
【００４５】
これらの光硬化型液晶性化合物は、重合により配向状態に固定化されて、光学異方性層を構成する。前記液晶性化合物は、実質的に均一に配向している状態に固定化されているのが好ましい。
光硬化型棒状液晶性化合物の場合は、実質的に水平（ホモジニアス）配向させるのが好ましい。実質的に水平とは、棒状液晶性化合物の長軸方向と光学異方性層の面との平均角度（平均傾斜角）が０°〜４０°の範囲内であることを意味する。棒状液晶性化合物を斜め配向させても良いし、傾斜角が徐々に変化するように（ハイブリッド配向）させても良い。斜め配向またはハイブリッド配向の場合でも、平均傾斜角は０°〜４０°であることが好ましい。
光硬化型円盤状液晶性化合物の場合は、実質的に垂直配向させるのが好ましい。実質的に垂直とは、円盤状液晶性化合物の円盤面と光学異方性層の面との平均角度（平均傾斜角）が５０°〜９０°の範囲内であることを意味する。円盤状液晶性化合物を斜め配向させても良いし、傾斜角が徐々に変化するように（ハイブリッド配向）させてもよい。斜め配向またはハイブリッド配向の場合でも、平均傾斜角は５０°〜９０°であることが好ましい。
【００４６】
隣接する光学異方性層を有する位相差板を作製する場合は、隣接する下方の光学異方性層を、その上に形成する光学異方性層の配向膜として機能させることができる。但し、光学異方性層を、その上に形成する光学異方性層の配向膜として機能させる場合は、液晶性化合物とともに、炭素原子数が９以下の炭化水素基を有する変性ポリビニルアルコールを含有する組成物を用いて光学異方性層を形成し、さらに引き続き、該光学異方性層の表面にラビングを行って、上層の光学異方異方性層を形成するのが好ましい。
【００４７】
液晶性化合物とともに用いる、前記炭素原子数が９以下の炭化水素基を有する変性ポリビニルアルコールについて説明する。
好ましい変性ポリビニルアルコールとしては、下記式（ＰＸ）で表されるものである。
（ＰＸ）−（ＶＡｌ）_ｘ−（ＨｙＤ）_ｙ−（ＶＡｃ）_ｚ−
式中、ＶＡｌは、ビニルアルコールの繰り返し単位であり、ＨｙＤは炭素原子数が９以下の炭化水素基を有する繰り返し単位であり、ＶＡｃは酢酸ビニル繰り返し単位であり、ｘは２０〜９５質量％（好ましくは２５〜９０質量％）であり、ｙは２〜９８質量％（好ましくは１０〜８０質量％）であり、ｚは０〜３０質量％（好ましくは２〜２０質量％）である。
【００４８】
ＨｙＤに含まれる炭化水素基は、脂肪族基、芳香族基またはそれらの組み合わせである。脂肪族基は、環状、分岐状あるいは直鎖状のいずれでもよい。脂肪族基は、アルキル基（シクロアルキル基であってもよい）またはアルケニル基（シクロアルケニル基であってもよい）であることが好ましい。前記炭化水素基は置換基を有していてもよい。前記炭化水素基の炭素原子数は１〜９であり、１〜８が好ましい。ＨｙＤの好ましい例は、下記式（ＨｙＤ−Ｉ）および（ＨｙＤ−ＩＩ）で表される。
【００４９】
【化６】

【００５０】
式中、Ｌ^１は、−Ｏ−、−ＣＯ−、−ＳＯ_２−、−ＮＨ−、アルキレン基、アリーレン基およびそれらの組み合わせから選ばれる二価の連結基であり、Ｌ^２は単結合、または−Ｏ−、−ＣＯ−、−ＳＯ_２−、−ＮＨ−、アルキレン基、アリーレン基およびそれらの組み合わせから選ばれる二価の連結基であり、Ｒ^１およびＲ^２は、それぞれ炭素原子数が９以下の炭化水素基である。上記の組み合わせにより形成される二価の連結基の例を以下に示す。
【００５１】
Ｌ１：−Ｏ−ＣＯ−
Ｌ２：−Ｏ−ＣＯ−アルキレン基−Ｏ−
Ｌ３：−Ｏ−ＣＯ−アルキレン基−ＣＯ−ＮＨ−
Ｌ４：−Ｏ−ＣＯ−アルキレン基−ＮＨ−ＳＯ_２−アリーレン基−Ｏ−
Ｌ５：−アリーレン基−ＮＨ−ＣＯ−
Ｌ６：−アリーレン基−ＣＯ−Ｏ−
Ｌ７：−アリーレン基−ＣＯ−ＮＨ−
Ｌ８：−アリーレン基−Ｏ−
Ｌ９：−Ｏ−ＣＯ−ＮＨ−アリーレン基−ＮＨ−ＣＯ−
【００５２】
ＨｙＤの具体例を以下に示す。
【００５３】
【化７】

【００５４】
前記変性ポリビニルアルコールの重合度は、２００〜５０００であることが好ましく、３００〜３０００であることが好ましい。ポリマーの分子量は、９０００〜２０００００であることが好ましく、１３０００〜１３００００であることがさらに好ましい。二種類以上のポリマーを併用してもよい。
【００５５】
以下に好ましい変性ポリビニルアルコールの具体例を示すが、本発明はこれらに限定されるものではない。
ＰＸ−１：−（ＶＡｌ）_２１−（ＨｙＤ−１３）_７７−（ＶＡｃ）_２−
ＰＸ−２：−（ＶＡｌ）_１４−（ＨｙＤ−１３）_８４−（ＶＡｃ）_２−
ＰＸ−３：−（ＶＡｌ）_２１−（ＨｙＤ−１６）_７７−（ＶＡｃ）_２−
ＰＸ−４：−（ＶＡｌ）_３４−（ＨｙＤ−１５）_６４−（ＶＡｃ）_２−
ＰＸ−５：−（ＶＡｌ）_２９−（ＨｙＤ−１２）_６９−（ＶＡｃ）_２−
ＰＸ−６：−（ＶＡｌ）_４６−（ＨｙＤ−１４）_５２−（ＶＡｃ）_２−
ＰＸ−７：−（ＶＡｌ）_２１−（ＨｙＤ−２）_７７−（ＶＡｃ）_２−
ＰＸ−８：−（ＶＡｌ）_１７−（ＨｙＤ−８）_８５−（ＶＡｃ）_２−
ＰＸ−９：−（ＶＡｌ）_２１−（ＨｙＤ−１３）_７７−（ＶＡｃ）_２−
ＰＸ−１０：−（ＶＡｌ）_４６−（ＨｙＤ−９）_５２−（ＶＡｃ）_２−
【００５６】
上記変性ポリビニルアルコールの添加量は、該制御剤の添加する液晶性化合物に対し０．０５質量％〜１０質量％添加することが好ましい。より好ましくは０．１質量〜５質量％である。
【００５７】
上記変性ポリビニルアルコールは縮合剤と併用してもよい。縮合剤としてはイソシアネート基またはホルミル基を末端に有する化合物が好ましい。以下に具体的な化合物を挙げるが、これらに限定されるものではない。
【００５８】
ポリ（１，４−ブタンジオール）、イソホロンジイソシアネートターミネーテッド
ポリ（１，４−ブタンジオール）、トリレン２，４−ジイソシアネートターミネーテッド
ポリ（エチレンアジペート）、トリレン２，４−ジイソシアネートターミネーテッド
ポリ（プロピレングリコール）、トリレン２，４−ジイソシアネートターミネーテッド、
１、６−ジイソシアナートヘキサン
１、８−ジイソシアナートオクタン
１、１２−ジイソシアナートドデカン
イソホロンジイソシアナート
グリオキザール
【００５９】
［空気界面側の配向制御用添加剤］
棒状液晶性化合物は、ホモジニアス配向（水平配向）においては、配向膜側では水平であるものの空気界面側では傾斜（チルト）配向する傾向がある。この性質を抑えるためには、配向制御用添加剤を用いるのが好ましく、下記式（Ｖ）で表される添加剤を用いるのが特に好ましい。
一般式（Ｖ）
（Ｈｂ−Ｌ^２−）_ｎＢ^１
式（Ｖ）において、Ｈｂは、炭素原子数が６〜４０の脂肪族基または炭素原子数が６〜４０の脂肪族置換オリゴシロキサノキシ基を表す。Ｈｂは、炭素原子数が６〜４０の脂肪族基であることが好ましく、炭素原子数が６〜４０のフッ素置換脂肪族基または炭素原子数が６〜４０の分岐を有する脂肪族基であることがさらに好ましく、炭素原子数が６〜４０のフッ素置換アルキル基もしくは炭素原子数が６〜４０の分岐を有するアルキル基であることが最も好ましい。
【００６０】
脂肪族基は、環状脂肪族基よりも鎖状脂肪族基の方が好ましい。鎖状脂肪族基は分岐を有していてもよい。脂肪族基の炭素原子数は、７〜３５であることが好ましく、８〜３０であることがより好ましく、９〜２５であることがさらに好ましく、１０〜２０であることが最も好ましい。
脂肪族基には、アルキル基、置換アルキル基、アルケニル基、置換アルケニル基、アルキニル基および置換アルキニル基が含まれる。アルキル基、置換アルキル基、アルケニル基および置換アルケニル基が好ましく、アルキル基および置換アルキル基がさらに好ましい。
脂肪族基の置換基の例には、ハロゲン原子、ヒドロキシル基、シアノ基、ニトロ基、アルコキシ基、置換アルコキシ基（例えば、オリゴアルコキシ基）、アルケニルオキシ基（例、ビニルオキシ）、アシル基（例、アクリロイル、メタクリロイル）、アシルオキシ基（例、アクリロイルオキシ、ベンゾイルオキシ）、スルファモイル基、脂肪族置換スルファモイル基およびエポキシアルキル基（例、エポキシエチル）が含まれる。置換基としては、ハロゲン原子が好ましく、フッ素原子がさらに好ましい。フッ素置換脂肪族基において、フッ素原子が脂肪族基の水素原子を置換している割合は、５０〜１００％であることが好ましく、６０〜１００％であることがより好ましく、７０〜１００％であることがさらに好ましく、８０〜１００％であることがさらにまた好ましく、８５〜１００％であることが最も好ましい。
【００６１】
前記脂肪族置換オリゴシロキサノキシ基の炭素原子数は、７〜３５であることが好ましく、８〜３０であることがより好ましく、９〜２５であることがさらに好ましく、１０〜２０であることが最も好ましい。脂肪族置換オリゴシロキサノキシ基は、下記式で表される。
Ｒ^１−（Ｓｉ（Ｒ^２）_２−Ｏ）_ｑ−
式中、Ｒ^１は水素原子、ヒドロキシルまたは脂肪族基を表し；Ｒ^２は水素原子、脂肪族基またはアルコキシ基を表し；そして、ｑは１〜１２のいずれかの整数を表す。Ｒ^１およびＲ^２でそれぞれ表される脂肪族基は、環状脂肪族基よりも鎖状脂肪族基の方が好ましい。鎖状脂肪族基は分岐を有していてもよい。脂肪族基の炭素原子数は、１〜１２であることが好ましく、１〜８であることがより好ましく、１〜６であることがさらに好ましく、１〜４であることが特に好ましい。
Ｒ^１およびＲ^２でそれぞれ表される脂肪族基には、アルキル基、置換アルキル基、アルケニル基、置換アルケニル基、アルキニル基および置換アルキニル基が含まれる。アルキル基、置換アルキル基、アルケニル基および置換アルケニル基が好ましく、アルキル基および置換アルキル基がさらに好ましい。
Ｒ^１およびＲ^２でそれぞれ表される脂肪族基は、置換基を有していてもよく、該置換基の例には、ハロゲン原子、ヒドロキシル基、シアノ基、ニトロ基、アルコキシ基、置換アルコキシ基（例えば、オリゴアルコキシ基）、アルケニルオキシ基（例、ビニルオキシ）、アシル基（例、アクリロイル、メタクリロイル）、アシルオキシ基（例、アクリロイルオキシ、ベンゾイルオキシ）、スルファモイル基、脂肪族置換スルファモイル基およびエポキシアルキル基（例、エポキシエチル）が含まれる。
【００６２】
Ｒ^２で表されるアルコキシ基は、環状構造あるいは分岐を有していてもよい。アルコキシ基の炭素原子数は、１〜１２であることが好ましく、１〜８であることがより好ましく、１〜６であることがさらに好ましく、１〜４であることがさらにまた好ましい。
以下に、Ｈｂの例を示す。
【００６３】
Ｈｂ１：ｎ−Ｃ_１６Ｈ_３３−
Ｈｂ２：ｎ−Ｃ_２０Ｈ_４１−
Ｈｂ３：ｎ−Ｃ_６Ｈ_１３−ＣＨ（ｎ−Ｃ_４Ｈ_９）−ＣＨ_２−ＣＨ_２−
Ｈｂ４：ｎ−Ｃ_１２Ｈ_２５−
Ｈｂ５：ｎ−Ｃ_１８Ｈ_３７−
Ｈｂ６：ｎ−Ｃ_１４Ｈ_２９−
Ｈｂ７：ｎ−Ｃ_１５Ｈ_３１−
Ｈｂ８：ｎ−Ｃ_１０Ｈ_２１−
Ｈｂ９：ｎ−Ｃ_１０Ｈ_２１−ＣＨ（ｎ−Ｃ_４Ｈ_９）−ＣＨ_２−ＣＨ_２−
Ｈｂ１０：ｎ−Ｃ_８Ｆ_１７−
【００６４】
Ｈｂ１１：ｎ−Ｃ_８Ｈ_１７−
Ｈｂ１２：ＣＨ（ＣＨ_３）_２−｛Ｃ_３Ｈ_６−ＣＨ（ＣＨ_３）｝_３−Ｃ_２Ｈ_４−
Ｈｂ１３：ＣＨ（ＣＨ_３）_２−｛Ｃ_３Ｈ_６−ＣＨ（ＣＨ_３）｝_２−Ｃ_３Ｈ_６−Ｃ（ＣＨ_３）＝ＣＨ−ＣＨ_２−
Ｈｂ１４：ｎ−Ｃ_８Ｈ_１７−ＣＨ（ｎ−Ｃ_６Ｈ_１３）−ＣＨ_２−ＣＨ_２−
Ｈｂ１５：ｎ−Ｃ_６Ｈ_１３−ＣＨ（Ｃ_２Ｈ_５）−ＣＨ_２−ＣＨ_２−
Ｈｂ１６：ｎ−Ｃ_８Ｆ_１７−ＣＨ（ｎ−Ｃ_４Ｆ_９）−ＣＨ_２−
Ｈｂ１７：ｎ−Ｃ_８Ｆ_１７−ＣＦ（ｎ−Ｃ_６Ｆ_１３）−ＣＦ_２−ＣＦ_２−
Ｈｂ１８：ｎ−Ｃ_３Ｆ_７−ＣＦ（ＣＦ_３）−ＣＦ_２−
Ｈｂ１９：Ｓｉ（ＣＨ_３）_３−｛Ｓｉ（ＣＨ_３）_２−Ｏ｝_６−Ｏ−
Ｈｂ２０：Ｓｉ（ＯＣ_３Ｈ_７）（Ｃ_１６Ｆ_３３）（Ｃ_２Ｈ_４−ＳＯ_２−ＮＨ−Ｃ_８Ｆ_１７）−Ｏ−
【００６５】
前記式（Ｖ）において、Ｌ^２は、単結合または二価の連結基を表す。前記二価の連結基は、−アルキレン基−、−フッ素置換アルキレン基−、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ−、−ＳＯ_２−およびそれらの組み合わせからなる群より選ばれる基であることが好ましい。Ｒは、水素原子または炭素原子数が１〜２０のアルキル基である。Ｌ^１Ａは、−アルキレン基−、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ−、−ＳＯ_２−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さらに好ましい。Ｒは、水素原子または炭素原子数が１〜２０のアルキル基であることが好ましく、水素原子または炭素原子数が１〜１５のアルキル基であることがさらに好ましく、水素原子または炭素原子数が１〜１２のアルキル基であることが最も好ましい。
上記アルキレン基またはフッ素置換アルキレン基の炭素原子数は、１〜４０であることが好ましく、１〜３０であることがより好ましく、１〜２０であることがさらに好ましく、１〜１５であることがさらにまた好ましく、１〜１２であることが最も好ましい。
以下に、Ｌ^２の例を示す。左側がＨｂに結合し、右側がＢ^１に結合する。
【００６６】
Ｌ１０：単結合
Ｌ１１：−Ｏ−
Ｌ１２：−Ｏ−ＣＯ−
Ｌ１３：−ＣＯ−Ｃ_４Ｈ_８−Ｏ−
Ｌ１４：−Ｏ−Ｃ_２Ｈ_４−Ｏ−Ｃ_２Ｈ_４−Ｏ−
Ｌ１５：−Ｓ−
Ｌ１６：−Ｎ（ｎ−Ｃ_１２Ｈ_２５）−
Ｌ１７：−ＳＯ_２−Ｎ（ｎ−Ｃ_３Ｈ_７）−ＣＨ_２ＣＨ_２−Ｏ−
Ｌ１８：−Ｏ−｛ＣＦ（ＣＦ_３）−ＣＦ_２−Ｏ｝_３−ＣＦ（ＣＦ_３）−
【００６７】
前記式（Ｖ）において、ｎは２〜１２のいずれかの整数を表す。ｎは２〜９のいずれかの整数であることが好ましく、２〜６のいずれかの整数であることがより好ましく、２、３または４であることがさらに好ましく、３または４であることが最も好ましい。
【００６８】
前記式（Ｖ）において、Ｂ^１は、少なくとも三つの環状構造を含む排除体積効果を有するｎ価の基である。Ｂ^１は下記式（Ｖ−ａ）で表されるｎ価の基であることが好ましい。
一般式（Ｖ−ａ）
（−Ｃｙ^１−Ｌ^３−）_ｎＣｙ^２
前記式（Ｖ−ａ）において、Ｃｙ^１は二価の環状基を表す。Ｃｙ^１は二価の芳香族炭化水素基または二価の複素環基を表すのが好ましく、二価の芳香族炭化水素基を表すのがより好ましい。
二価の芳香族炭化水素基とは、アリーレン基および置換アリーレン基を意味する。
アリーレン基の例には、フェニレン基、インデニレン基、ナフチレン基、フルオレニレン基、フェナントレニレン基、アントリレン基およびピレニレン基が含まれる。フェニレン基およびナフチレン基が好ましい。
置換アリーレン基の置換基の例には、脂肪族基、芳香族炭化水素基、複素環基、ハロゲン原子、アルコキシ基（例えば、メトキシ基、エトキシ基、メトキシエトキシ基）、アリールオキシ基（例えば、フェノキシ基）、アリールアゾ基（例えば、フェニルアゾ基）、アルキルチオ基（例えば、メチルチオ基、エチルチオ基、プロピルチオ基）、アルキルアミノ基（例えば、メチルアミノ基、プロピルアミノ基）、アシル基（例えば、アセチル基、プロパノイル基、オクタノイル基、ベンゾイル基）、アシルオキシ基（例えば、アセトキシ基、ピバロイルオキシ基、ベンゾイルオキシ基）、ヒドロキシル基、メルカプト基、アミノ基、カルボキシル基、スルホ基、カルバモイル基、スルファモイル基およびウレイド基が含まれる。
二価の芳香族炭化水素基に、別の芳香族炭化水素環が単結合、ビニレン結合またはエチニレン結合を介して置換基として結合していると、前述したように特定の液晶配向促進機能が得られる。
また、Ｈｂ−Ｌ^２−に相当する基を、置換基として有してもよい。
【００６９】
Ｃｙ^１で表される二価の複素環基は、５員、６員または７員の複素環を有することが好ましい。５員環または６員環がさらに好ましく、６員環が最も好ましい。複素環を構成する複素原子としては、窒素原子、酸素原子および硫黄原子が好ましい。前記複素環は、芳香族性複素環であることが好ましい。芳香族性複素環は、一般に不飽和複素環である。最多二重結合を有する不飽和複素環がさらに好ましい。複素環の例には、フラン環、チオフェン環、ピロール環、ピロリン環、ピロリジン環、オキサゾール環、イソオキサゾール環、チアゾール環、イソチアゾール環、イミダゾール環、イミダゾリン環、イミダゾリジン環、ピラゾール環、ピラゾリン環、ピラゾリジン環、トリアゾール環、フラザン環、テトラゾール環、ピラン環、チイン環、ピリジン環、ピペリジン環、オキサジン環、モルホリン環、チアジン環、ピリダジン環、ピリミジン環、ピラジン環、ピペラジン環およびトリアジン環が含まれる。
【００７０】
複素環に、他の複素環、脂肪族環または芳香族炭化水素環が縮合していてもよい。縮合複素環の例には、ベンゾフラン環、イソベンゾフラン環、ベンゾチオフェン環、インドール環、インドリン環、イソインドール環、ベンゾオキサゾール環、ベンゾチアゾール環、インダゾール環、ベンゾイミダゾール環、クロメン環、クロマン環、イソクロマン環、キノリン環、イソキノリン環、シンノリン環、フタラジン環、キナゾリン環、キノキサリン環、ジベンゾフラン環、カルバゾール環、キサンテン環、アクリジン環、フェナントリジン環、フェナントロリン環、フェナジン環、フェノキサジン環、チアントレン環、インドリジン環、キノリジン環、キヌクリジン環、ナフチリジン環、プリン環およびプテリジン環が含まれる。
二価の複素環基は、置換基を有していてもよい。置換基の例は、置換アリーレン基の置換基の例と同様である。
二価の複素環基は、複素原子（例えば、ピペリジン環の窒素原子）で、Ｌ^３または（Ｌ^３が単結合の場合）分子中心の環状基（Ｃｙ^２）と結合してもよい。また、結合する複素原子がオニウム塩（例、オキソニウム塩、スルホニウム塩、アンモニウム塩）を形成していもよい。
【００７１】
Ｃｙ^１および後述するＣｙ^２の環状構造が、全体として平面構造を形成していてもよい。環状構造が全体として平面構造（すなわち円盤状構造）を形成していると、前述したように特定の液晶配向促進機能が得られる。
以下に、Ｃｙ^１の例を示す。複数のＨｂ−Ｌ^２−に相当する基が二価の芳香族炭化水素基または二価の複素環基に結合している場合、いずれか一つが前記式で定義するＨｂ−Ｌ^２−であって、残りは二価の芳香族炭化水素基または二価の複素環基の置換基である。
【００７２】
【化８】

【００７３】
【化９】

【００７４】
【化１０】

【００７５】
【化１１】

【００７６】
【化１２】

【００７７】
【化１３】

【００７８】
【化１４】

【００７９】
式（Ｖ−ａ）において、Ｌ^３は、単結合または−アルキレン基−、−アルケニレン基−、−アルキニレン基−、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ−、−ＳＯ_２−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。Ｒは、水素原子または炭素原子数が１〜３０のアルキル基を表す。Ｌ^３は、−Ｏ−、−Ｓ−、−ＣＯ−、−ＮＲ−、−ＳＯ_２−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。Ｒは水素原子または炭素原子数が１〜２０のアルキル基であることが好ましく、水素原子または炭素原子数が１〜１５のアルキル基であることがさらに好ましく、水素原子または炭素原子数が１〜１２のアルキル基であることが最も好ましい。
上記アルキレン基の炭素原子数は、１〜４０であることが好ましく、１〜３０であることがより好ましく、１〜２０であることがさらに好ましく、１〜１５であることがさらにまた好ましく、１〜１２であることが最も好ましい。
上記アルケニレン基またはアルキニレン基の炭素原子数は、２〜４０であることが好ましく、２〜３０であることがより好ましく、２〜２０であることがさらに好ましく、２〜１５であることがさらにまた好ましく、２〜１２であることが最も好ましい。
以下に、Ｌ^３の例を示す。左側がＣｙ^１に結合し、右側がＣｙ^２に結合する。
【００８０】
Ｌ２０：単結合
Ｌ２１：−Ｓ−
Ｌ２２：−ＮＨ−
Ｌ２３：−ＮＨ−ＳＯ_２−ＮＨ−
Ｌ２４：−ＮＨ−ＣＯ−ＮＨ−
Ｌ２５：−ＳＯ_２−
Ｌ２６：−Ｏ−ＮＨ−
Ｌ２７：−Ｃ≡Ｃ−
Ｌ２８：−ＣＨ＝ＣＨ−Ｓ−
Ｌ２９：−ＣＨ_２−Ｏ−
Ｌ３０：−Ｎ（ＣＨ_３）−
Ｌ３１：−ＣＯ−Ｏ−
【００８１】
前記式（Ｖ−ａ）において、ｎは２〜１２のいずれかの整数を表す。ｎは２〜９のいずれかの整数であることが好ましく、２〜６のいずれかの整数であることがより好ましく、２、３または４であることがさらに好ましく、３または４であることが最も好ましい。
前記式（Ｖ−ａ）において、Ｃｙ^２は、ｎ価の環状基である。Ｃｙ^２は、ｎ価の芳香族炭化水素基またはｎ価の複素環基であることが好ましい。
Ｃｙ^２で表される芳香族炭化水素基の芳香族炭化水素環の例には、ベンゼン環、インデン環、ナフタレン環、フルオレン環、フェナントレン環、アントラセン環およびピレン環が含まれる。ベンゼン環およびナフタレン環が好ましく、ベンゼン環が特に好ましい。
Ｃｙ^２で表される芳香族炭化水素基は置換基を有していてもよい。置換基の例には、脂肪族基、芳香族炭化水素基、複素環基、ハロゲン原子、アルコキシ基（例えば、メトキシ基、エトキシ基、メトキシエトキシ基）、アリールオキシ基（例えば、フェノキシ基）、アリールアゾ基（例えば、フェニルアゾ基）、アルキルチオ基（例えば、メチルチオ基、エチルチオ基、プロピルチオ基）、アルキルアミノ基（例えば、メチルアミノ基、プロピルアミノ基）、アリールアミノ基（例えば、フェニルアミノ基）、アシル基（例えば、アセチル基、プロパノイル基、オクタノイル基、ベンゾイル基）、アシルオキシ基（例えば、アセトキシ基、ピバロイルオキシ基、ベンゾイルオキシ基）、ヒドロキシル基、メルカプト基、アミノ基、カルボキシル基、スルホ基、カルバモイル基、スルファモイル基およびウレイド基が含まれる。
【００８２】
Ｃｙ^２で表される複素環基は、５員、６員または７員の複素環を有することが好ましい。５員環または６員環がさらに好ましく、６員環が最も好ましい。前記複素環を構成する複素原子としては、窒素原子、酸素原子および硫黄原子が好ましい。前記複素環は、芳香族性複素環であることが好ましい。芳香族性複素環は、一般に不飽和複素環である。最多二重結合を有する不飽和複素環がさらに好ましい。前記複素環の例には、フラン環、チオフェン環、ピロール環、ピロリン環、ピロリジン環、オキサゾール環、イソオキサゾール環、チアゾール環、イソチアゾール環、イミダゾール環、イミダゾリン環、イミダゾリジン環、ピラゾール環、ピラゾリン環、ピラゾリジン環、トリアゾール環、フラザン環、テトラゾール環、ピラン環、チイン環、ピリジン環、ピペリジン環、オキサジン環、モルホリン環、チアジン環、ピリダジン環、ピリミジン環、ピラジン環、ピペラジン環およびトリアジン環が含まれる。トリアジン環が好ましく、１，３，５−トリアジン環が特に好ましい。
前記複素環に他の複素環、脂肪族環または芳香族炭化水素環が縮合していてもよい。ただし、単環式複素環が好ましい。
以下に、Ｃｙ^２の例を示す。
【００８３】
【化１５】

【００８４】
【化１６】

【００８５】
【化１７】

【００８６】
【化１８】

【００８７】
液晶配向促進剤は、以上述べた疎水性基（Ｈｂ）、連結基（Ｌ^２）および排除体積効果を有する基（Ｂ^１）を組み合わせた化合物である。これらの組み合わせについて、特に制限はない。
以下に、前記一般式（Ｖ）で表される液晶配向促進剤の例を示す。
【００８８】
【化１９】

【００８９】
【化２０】

【００９０】
【化２１】

【００９１】
【化２２】

【００９２】
【化２３】

【００９３】
【化２４】

【００９４】
【化２５】

【００９５】
【化２６】

【００９６】
【化２７】

【００９７】
【化２８】

【００９８】
【化２９】

【００９９】
【化３０】

【０１００】
【化３１】

【０１０１】
【化３２】

【０１０２】
【化３３】

【０１０３】
【化３４】

【０１０４】
【化３５】

【０１０５】
【化３６】

【０１０６】
【化３７】

【０１０７】
【化３８】

【０１０８】
【化３９】

【０１０９】
【化４０】

【０１１０】
【化４１】

【０１１１】
【化４２】

【０１１２】
【化４３】

【０１１３】
【化４４】

【０１１４】
【化４５】

【０１１５】
【化４６】

【０１１６】
【化４７】

【０１１７】
【化４８】

【０１１８】
【化４９】

【０１１９】
【化５０】

【０１２０】
【化５１】

【０１２１】
【化５２】

【０１２２】
【化５３】

【０１２３】
【化５４】

【０１２４】
【化５５】

【０１２５】
【化５６】

【０１２６】
【化５７】

【０１２７】
【化５８】

【０１２８】
【化５９】

【０１２９】
【化６０】

【０１３０】
【化６１】

【０１３１】
【化６２】

【０１３２】
【化６３】

【０１３３】
【化６４】

【０１３４】
本発明において、光学異方性層は、前記光硬化型液晶性化合物、所望により、前記変性ポリビニルアルコール、および下記の重合開始剤や他の添加剤を溶媒に溶解させた塗布液を、ラビング表面に塗布して形成するのが好ましい。塗布液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。塗布液の塗布は、公知の方法（例、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。
【０１３５】
［液晶性化合物の配向状態の固定化］
配向させた液晶性化合物は、配向状態を維持して固定化することが好ましい。固定化は、液晶性化合物に導入した重合性基の重合反応により実施することが好ましい。重合反応における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０．０１〜２０質量％であることが好ましく、０．５〜５質量％であることがさらに好ましい。
【０１３６】
光硬化型液晶性化合物の重合のための光照射には、紫外線を用いることが好ましい。照射エネルギーは、２０ｍＪ／ｃｍ^２〜５０Ｊ／ｃｍ^２であることが好ましく、１００〜８００ｍＪ／ｃｍ^２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。また、光照射する際の雰囲気中の酸素濃度を窒素置換等によって下げることも反応促進に効果がある。
光学異方性層の厚さは、０．１〜１０μｍであることが好ましく、０．５〜５μｍであることがさらに好ましい。
【０１３７】
［配向膜と光学異方性層間の密着性］
本発明では、配向膜と光学異方性層との密着性を向上させるために、配向膜に上記記載の重合性基を有するポリマーを使用するとともに、光照射と加熱を同時に行う工程を実施する。光照射の好ましい条件については、前記と同様である。加熱は、６０度以上、好ましくは７０度以上、さらに好ましくは８０度以上である。但し、１３０度を超えて加熱を行うと、支持体の変形、配向膜の配向規制力の低下等の不具合が生じ、好ましくない。光照射と加熱を同時に行う前記工程は、光硬化型液晶性化合物の硬化、即ち、光学異方性層の形成のための工程であってもよいし、また、一旦、前記光硬化型液晶性化合物を仮重合により固定させて光学異方性層を形成した後、さらにその上に光学異方性層を積層した後に行ってもよい。後者の態様では、光硬化型液晶性化合物の液晶相の温度範囲が低温側にある場合、低温で仮重合して光学異方性層を形成でき、加熱状態の重合では得られない、高い屈折率異方性を有する光学異方性層を形成できる点で有効である。また、不要な熱重合による配向乱れを防ぐことができる点でも有利である。
【０１３８】
［光学異方性層同士間の密着性］
光硬化型液晶性化合物からなる、直接接する２層の光学異方性層の密着性を向上させるためには、下層の光学異方性層を形成する重合工程において、該層の最表面の重合を不完全として、表面に重合性基を残し、続いて、該光学異方性層上に、光硬化型液晶性化合物を含む層を塗布し、さらに重合を行って、上層の光学異方性層を形成する。下層と上層の光学異方性層間に化学結合が形成され、密着性が向上する。該光学異方性層の最表面の重合を不完全とする方法としては、ラジカル失活剤等が存在する雰囲気（例えば、酸素濃度がの１０％以上の雰囲気）下で重合を行うこと、光照射量を落とす等の方法が上げられるがこれらに限定されない。
【０１３９】
［位相差板の光学的性質］
本発明の製造方法によって製造された位相差板は、光学異方性層が特定の波長において、実質的にπまたはπ／２の位相差を達成していることが好ましい。特定波長（λ）において位相差πを達成するためには、特定波長（λ）において測定した偏光子のレターデーション値をλ／２に調整すればよく、特定波長（λ）において位相差π／２を達成するためには、特定波長（λ）において測定した偏光子のレターデーション値をλ／４に調整すればよい。例えば、２層の光学異方性層を有する位相差板では、可視領域のほぼ中間の波長である５５０ｎｍにおいて、一方が位相差πおよび他方がπ／２を達成していることが好ましい。一方の光学異方性層（第１光学異方性層）は、波長５５０ｎｍで測定したレターデーション値が２４０〜２９０ｎｍであることが好ましく、２５０〜２８０ｎｍであることがより好ましい。もう一方の光学異方性層（第２光学異方性層）は、波長５５０ｎｍで測定したレターデーション値が１１０〜１４５ｎｍであることが好ましく、１２０〜１４０ｎｍであることがより好ましい。
【０１４０】
レターデーション値とは、光学異方性層の法線方向から入射した光に対する面内のレターデーション値を意味する。具体的には、下記式により定義される値である。
レターデーション値（Ｒｅ）＝（ｎｘ−ｎｙ）×ｄ
式中、ｎｘおよびｎｙは光学異方性層の面内の主屈折率であり、そしてｄは光学異方性層の厚み（ｎｍ）である。
【０１４１】
前記第１および第２の光学異方性層の厚さは、各々の層が所望のレターデーションを示す範囲で任意に決定することができる。例えば、同一の棒状液晶化合物を水平配向させて、前記第１および第２の光学異方性層を各々形成する場合は、位相差がπである光学異方性層の厚みを、位相差がπ／２の光学異方性の厚みの倍にするのが好ましい。それぞれの光学異方性層の厚みの好ましい範囲は、用いる液晶性化合物の種類によって異なるが、一般的には、０．１〜１０μｍであり、０．２〜０．８μｍがより好ましく、０．５〜５μｍがさらに好ましい。
【０１４２】
［位相差板および円偏光板の構成］
図１は、棒状液晶性化合物を用いた場合の、位相差板の代表的な構成を示す模式図である。図１に示すように、基本的な位相差板は、長尺状の透明支持体（Ｓ）および第１の光学異方性層（Ａ）に加えて、さらに第２の光学異方性層（Ｂ）を有する。第１の光学異方性層（Ａ）の位相差はπである。第２の光学異方性層（Ｂ）の位相差は、π／２である。透明支持体（Ｓ）の長手方向と第１の光学異方性層（Ａ）の遅相軸（ａ）とのなす角は３０°である。第２の光学異方性層（Ｂ）の遅相軸（ｂ）と第１の光学異方性層（Ａ）の遅相軸（ａ）との角度（γ）は６０゜である。図１に示す第１光学異方性層（Ａ）および第２光学異方性層（Ｂ）は、それぞれ棒状液晶性化合物（ｃ１およびｃ２）を含む。棒状液晶性化合物ｃ１およびｃ２は水平に配向している。棒状液晶性化合物の長軸方向が光学異方性層の遅相軸（ａおよびｂ）に相当する。
【０１４３】
なお、図１では、便宜のため、透明支持体Ｓにより近い位置にあるのが光学異方性層Ａ（位相差がπ）で、その外側に位置するのが光学異方性層Ｂ（位相差がπ／２）である位相差板および円偏光板の構成を示したが、光学異方性層Ａと光学異方性層Ｂとの位置を入れ替えた構成であってもよいが、好ましくは、透明支持体Ｓにより近い位置に光学異方性層Ａ（位相差がπ）、その外側に光学異方性層Ｂ（位相差がπ／２）が位置する構成である。
後述する図２においても同様である。
【０１４４】
［円偏光板］
本発明の位相差板は、反射型液晶表示装置において使用されるλ／４板、光ディスクの書き込み用のピックアップに使用されるλ／４板、あるいは反射防止膜として利用されるλ／４板として、特に有利に用いることができる。λ／４板は、一般に偏光膜と組み合わせた円偏光板として使用される。よって、位相差板と偏光膜とを組み合わせた円偏光板として構成しておくと、容易に反射型液晶表示装置のような用途とする装置に組み込むことができる。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ィルムを用いて製造する。
【０１４５】
［円偏光板の構成］
図２は、棒状液晶性化合物を用いた位相差板を有する円偏光板の代表的な構成を示す模式図である。図２に示す円偏光板は、図１に示した透明支持体（Ｓ）、第１光学異方性層（Ａ）および第２光学異方性層（Ｂ）に加えて、さらに偏光膜（Ｐ）を有する。偏光膜の偏光透過軸（ｐ）は透明支持体（Ｓ）の長手方向（ｓ）のなす角は４５°であり、偏光透過軸と光学異方性層（Ａ）の遅相軸（ａ）のなす角は１５°であり、図１と同様に、光学異方性層（Ａ）の遅相軸（ａ）と光学異方性層（Ｂ）の遅相軸（ｂ）とのなす角は６０°である。図２に示す第１光学異方性層（Ａ）および第２光学異方性層（Ｂ）も、それぞれ棒状液晶性化合物（ｃ１およびｃ２）を含む。棒状液晶性化合物（ｃ１およびｃ２）は、それぞれ水平に配向している。棒状液晶性化合物（ｃ１およびｃ２）の長軸方向が、光学異方性層（ＡおよびＢ）の面内の遅相軸（ａおよびｂ）に相当する。
【０１４６】
本発明の位相差板と組み合わせる偏光膜については、特に制限はなく、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を用いることができる。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ィルムを用いて製造する。本発明の位相差板の透明支持体の長手方向に対して、偏光膜の透過軸を４５°となるように積層するのが好ましい。長手方向に対して実質的に４５°方向に偏光の透過軸を有する偏光膜（以下４５°偏光膜と称する）を用いれば、積層の際の角度調整が不要になり、本発明の円偏光板を容易に作製できる。延伸フィルムからなる偏光膜の透過軸は、延伸方向と実質的に一致するので、フィルムを長手方向に対して４５°の方向に延伸処理することで、４５°偏光膜を作製することができる。このような実質的に４５°方向に偏光の透過軸を有する偏光膜（以下４５°偏光膜と称する）は、特開２００２−８６５５４号公報に記載の斜め延伸方法により作製することができ、第０００９欄〜第００４５欄の記載の条件、使用可能な装置の構成等を参考に作製することができる。
【０１４７】
本発明に用いられる４５°偏光板は、偏光の吸収軸すなわち延伸軸が長手方向に対して４５゜傾斜しており、この角度がＬＣＤにおける液晶セルに貼り合わせる際の偏光板の吸収軸と、液晶セル自身の縦または横方向とのなす角度に一致しているため、打ち抜き工程において斜めの打ち抜きは不要となる。しかも、前記斜め延伸方法によって作製された偏光板は切断が長手方向に沿って一直線であるため、打ち抜かず長手方向に沿ってスリットすることによっても製造可能であるため、生産性も格段に優れている。
【０１４８】
前記斜め延伸方法によって製造された偏光膜は、そのままの形態で偏光板として本発明の位相差板に用いることもできるが、両面あるいは片面に保護フィルムを貼り付けた形態のものを偏光板として用いるのが好ましい。保護フィルムの種類は特に限定されず、セルロースアセテート、セルロースアセテートブチレート、セルロースプロピオネート等のセルロースエステル類、ポリカーボネート、ポリオレフィン、ポリスチレン、ポリエステル等を用いることができるが、保護フィルムのレターデーション値が一定値以上であると、偏光軸と保護フィルムの配向軸が斜めにずれているため、直線偏光が楕円偏光に変化し、好ましくない。このため保護フィルムのレターデーションは低いことが好ましい。例えば、６３２．８ｎｍにおいて１０ｎｍ以下が好ましく、５ｎｍ以下がさらに好ましい。このような低レターデーションを得るためには、保護フィルムとして使用するポリマーはセルローストリアセテートが特に好ましい。また、ゼオネックス、ゼオノア（共に日本ゼオン（株）製）、ＡＲＴＯＮ（ＪＳＲ（株）製）のようなポリオレフィン類も好ましく用いられる。その他、例えば特開平８−１１０４０２号公報あるいは特開平１１−２９３１１６号公報に記載されているような非複屈折性光学樹脂材料が挙げられる。
【０１４９】
偏光膜と保護層との接着剤は特に限定されないが、ＰＶＡ系樹脂（アセトアセチル基、スルホン酸基、カルボキシル基、オキシアルキレン基等の変性ＰＶＡを含む）やホウ素化合物水溶液等が挙げられ、中でもＰＶＡ系樹脂が好ましい。接着剤層厚みは、乾燥後に０．０１〜１０μｍが好ましく、０．０５〜５μｍが特に好ましい。
【０１５０】
本発明に用いる偏光板は、液晶表示装置のコントラストを高める観点から、透過率は高い方が好ましく、偏光度は高い方が好ましい。透過率は好ましくは５５０ｎｍで３０％以上が好ましく、４０％以上がさらに好ましい。偏光度は５５０ｎｍで９５．０％以上が好ましく、９９％以上がさらに好ましく、特に好ましくは９９．９％以上である。
【０１５１】
偏光膜は、上記した様に、一般に両側に保護膜を有するが、本発明では、本発明の位相差板を偏光膜の片側の保護膜として機能させることができる。４５°偏光膜を用いて円偏光板を作製する場合、重ね合わせ方を変えることで容易に右および左円偏光板を作り分けることができる。
［円偏光板の構成］
図３に本発明の位相差板を用いた円偏光板の一態様の概略断面図を示す。
図３に示す円偏光板は、本発明の位相差版に４５°偏光膜Ｐおよび保護膜Ｇを積層した構成である。位相差板は、光学異方性層ＡおよびＢ（但し、図中には一層として示した）と、透明支持体Ｓとからなる。位相差板は、透明支持体Ｓの光学異方性層ＡおよびＢが設けられていない側の面を、４５°偏光膜Ｐに向けて積層されている。この構成において、前記位相差板は４５°偏光膜Ｐの保護膜としても機能する。図３中に、透明支持体Ｓの長手方向ｓと、光学異方性層ＡおよびＢの遅相軸ａおよびｂと、４５°偏光膜Ｐの透過軸ｐとの関係を併せて示す。
【０１５２】
図３の円偏光板を表示装置に組み込む場合は、保護膜Ｐ側を表示面側にする（図中の矢印で示す方向が見る方向を示す）。図３の構成から得られる円偏光板は右円偏光である。図３中、矢印方向から入射した光は、偏光膜Ｐ、光学異方性層ＡおよびＢを順次通過することによって右円偏光となって出射する。
【０１５３】
本発明の位相差版を用いた円偏光板の他の構成の概略断面図を図４に示す。図４に示す円偏光板は、図３に示す円偏光板の保護膜Ｇと位相差板の位置を代えた構成であり、図４中下方から、保護膜Ｇ、４５°偏光膜Ｐ、透明支持体Ｓおよび光学異方性層ＡおよびＢを積層した構成である。かかる構成の円偏光板では左円偏光が得られる。
この様に、４５°偏光膜に、保護層と位相差板を貼り合わせる場合に、上下を入れ替えて貼り合せるだけで右円偏光と左円偏光を製造することができる。
【０１５４】
透明支持体とは別に保護膜を用いる場合は、保護膜として光学的等方性が高いセルロースエステルフィルム、特にトリアセチルセルロースフィルムを用いることが好ましい。
【０１５５】
本発明の円偏光板は、波長４５０ｎｍ、５５０ｎｍおよび６５０ｎｍで測定したレターデーション値／波長の値が、いずれも０．２〜０．３の範囲内である、広帯域λ／４板であるのが好ましい。レターデーション値／波長の値は、０．２１〜０．２９の範囲内であることがより好ましく、０．２２〜０．２８の範囲内であることがさらに好ましく、０．２３〜０．２７の範囲内であることが特に好ましく、０．２４〜０．２６の範囲内であることが最も好ましい。
【０１５６】
【実施例】
以下に実施例を挙げて本発明をさらに具体的に説明する。以下の実施例に示す材料、試薬、物質量とその割合、操作等は本発明の主旨から逸脱しない限り適宜変更することができる従って本発明の範囲は以下の具体例に制限されるものではない。
［実施例１］
厚さ８０μｍ、幅６８０ｍｍ、長さ５００ｍの光学的に等方性のトリアセチルセルロースフィルム（酢化度６０．９％）を透明支持体として用いた。この透明支持体の両面をケン化処理した後、下記組成の配向膜塗布液を透明支持体の片面に連続的に塗布および乾燥し、厚さ１μｍの配向膜を形成した。次いで、透明支持体の長手方向に対し左手３０°の方向に連続的に配向膜上にラビング処理を実施した。
【０１５７】
配向膜塗布液組成
下記の変性ポリビニルアルコール　　　　　　　　　　　４．０重量％
水　　　　　　　　　　　　　　　　　　　　　　　　７２．５重量％
メタノール　　　　　　　　　　　　　　　　　　　　２３．３重量％
グルタールアルデヒド　　　　　　　　　　　　　　　　０．２重量％
【０１５８】
【化６５】

【０１５９】
配向膜の上に、下記の組成の塗布液をバーコーターを用いて連続的に塗布、乾燥、および加熱（配向熟成）し、さらに紫外線照射して光学異方性層（Ａ）を形成した。この紫外線照射時の温度を５０℃、６０℃および８０℃とした３種類の光学異方性層（Ａ５０、Ａ６０およびＡ８０）を作製した。光学異方性層は透明支持体の長手方向に対して３０°の方向に遅相軸を有していた。３種類の光学異方性層（Ａ５０、Ａ６０およびＡ８０）は５５０ｎｍにおけるレターデーション値（Ｒｅ５５０）が２６５ｎｍとなるように膜厚を調整した。それぞれの膜厚は２．０μｍ、２．２μｍおよび２．４μｍとなり、低温で重合することで膜厚を薄くすることが可能となった。
光学異方性層（Ａ）用塗布液組成
本発明の棒状液晶性化合物（例示化合物　Ｉ−１）　　　２０．１重量％
本発明の棒状液晶性化合物（例示化合物　Ｉ−４）　　　１８．０重量％
下記の増感剤（１）　　　　　　　　　　　　　　　　　　０．４重量％
下記の光重合開始剤（１）　　　　　　　　　　　　　　　１．１重量％
本明細書中の例示化合物（ＰＸ−８）　　　　　　　　　　０．４質量％
メチルエチルケトン　　　　　　　　　　　　　　　　　６０．０重量％
【０１６０】
増感剤（１）
【化６６】

【０１６１】
光重合開始剤（１）
【化６７】

【０１６２】
光学異方性層（Ａ）の遅相軸に対し＋６０°であり、かつ長手方向に対し＋３０°になるように連続的に光学異方性層（Ａ）上にラビング処理を施した。
ラビング処理した光学異方性層（Ａ５０、Ａ６０およびＡ８０）の上に、下記の組成の塗布液を、バーコーターを用いて連続的に塗布、乾燥、および加熱（配向熟成）し、さらに紫外線照射して光学異方性層（Ｂ）を形成し位相差板を作製した。３種の光学異方性層（Ａ５０、Ａ６０、Ａ８０）それぞれの上に、上記紫外線照射時の温度を５０，６０、８０度とした３種類の光学異方性層（Ｂ５０、Ｂ６０、Ｂ８０）を作製し、合計９種類の位相差板（Ａ５０−Ｂ５０、Ａ５０−Ｂ６０、Ａ５０−Ｂ８０、Ａ６０−Ｂ５０、Ａ６０−Ｂ６０、Ａ６０−Ｂ８０、Ａ８０−Ｂ５０、Ａ８０−Ｂ６０、Ａ８０−Ｂ８０）を作製した。
光学異方性層（Ｂ）用塗布液組成
本発明の棒状液晶性化合物（例示化合物　Ｉ−１）　　　２０．１重量％
本発明の棒状液晶性化合物（例示化合物　Ｉ−４）　　　１８．０重量％
実施例（１）の増感剤　　　　　　　　　　　　　　　　　０．４重量％
実施例（１）の光重合開始剤　　　　　　　　　　　　　　１．２重量％
式（Ｖ）の例示化合物Ｖ−（２７）　　　　　　　　　　　０．１重量％
メチルエチルケトン　　　　　　　　　　　　　　　　　６０．０重量％
【０１６３】
位相差板Ａ５０−Ｂ５０は一部を切り出し、５０℃、６０℃または８０℃に加熱しながらＵＶ照射をさらに行った。この３枚の位相差板をそれぞれＡ５０−Ｂ５０−５０、Ａ５０−Ｂ５０−６０、Ａ５０−Ｂ５０−８０とした。
光学異方性層（Ｂ）の膜厚は、位相差板の長手方向に対し４５度の角度で偏光板の遅相軸を配置し、偏光板側より常光を照射した場合に、偏光板、位相差板を透過した光が円偏光となるように決定した。
【０１６４】
［実施例２］
下式表わされる化合物を１：１で混合して重合性液晶組成物を調製した。得られた重合性液晶組成物は、室温でネマチック相を示し、ネマチック相から等方性液体相への相転移温度は４６℃であった。
実施例１と同様な方法で作製した配向膜の上に、下記の組成の塗布液をバーコーターを用いて連続的に塗布、乾燥、および加熱（配向熟成）し、さらに紫外線照射して光学異方性層（Ｃ）を形成した。この紫外線照射時の温度を４０℃および６０℃度とした２種類の光学異方性層（それぞれ、Ｃ４０およびＣ６０）を作製した。
光学異方性層（Ｃ）用塗布液組成
棒状液晶性化合物　（Ｎ１）　　　　　　　　　　　３０．０重量％
棒状液晶性化合物　（Ｎ２）　　　　　　　　　　　３０．０重量％
増感剤（１）　　　　　　　　　　　　　　　　　　　０．３重量％
光重合開始剤（１）　　　　　　　　　　　　　　　　１．０重量％
メチルエチルケトン　　　　　　　　　　　　　　　　３８．７重量％
【０１６５】
棒状液晶化合物（Ｎ１）
【化６８】

【０１６６】
棒状液晶化合物（Ｎ２）
【化６９】

【０１６７】
光学異方性層Ｃ４０は一部を切り出し、５０℃、６０℃、１３０℃および１４０℃に加熱しながらＵＶ照射をさらに行った。これら３枚の位相差板を、Ｃ４０−５０、Ｃ４０−６０、Ｃ４０−８０、Ｃ４０−１３０、Ｃ４０−１４０とした。ただし、Ｃ４０−１４０は、支持体が変形し光学異方性層の配向が乱れており位相差板として使用できないことがわかった。
【０１６８】
［密着試験］
得られた位相差板それぞれについて、光学異方性層の表面に、片刃のカミソリの刃を面に対して６０°の角度で切り込み、幅１０ｍｍ、深さはトリアセチルセルロースフィルムの表面に僅か達する程度の切込みを入れた。市販のセロファンテープを切れ込み部分をまたいでテープの一端を残して貼り、その上を擦ってよく接着させ、貼られてないテープのその一端を手で持ってなるべく垂直に力強く引張って剥がし、切り込み線からの貼られたテープ面積に対する硬化皮膜層が剥がされた面積の割合を下記の様に評価した。
Ａ　：　全く剥離されなかった
Ｂ　：　剥離された面積割合が３０％未満であった
Ｃ　：　剥離された面積割合が３０〜７０％未満であった
Ｄ　：　剥離された面積割合が７０％以上であった。
下表には作成した位相差板の密着性、配向性、光学異方性層全体ＡとＢの厚みを示した。
【０１６９】
【表１】

【０１７０】
以上の結果より、光照射時に６０℃以上の加熱を行った場合にのみ良好な密着が得られることが分かった。
また、６０℃より８０℃で光照射を行った場合により密着性が向上していた。低温で硬化した場合に膜厚が薄い位相差板が得られ、５０℃で光学異方性層ＡおよびＢを硬化し、その後さらに光照射を行ったサンプルにおいて膜厚も薄く密着も充分な位相差板が得られた。
光学異方性層Ｃでは、液晶の転移温度が低く、６０℃では液晶が等方相であったため硬化したものでは密着は高かったものの、配向状態が固定化されなかった。４０℃で硬化したものでは、配向固定後に６０℃以上で再度光照射することにより充分な密着性が得られ、この方法によれば、液晶相温度範囲が低温側にある場合にも充分な密着を得ることができる。
【０１７１】
【発明の効果】
本発明によれば、液晶層が室温近辺の棒状液晶性化合物を用いる場合や屈折率異方性を高くしたい場合等においても、配向膜との充分な密着が得られ長期保存時等であっても剥離等の不具合が発生しない高品質な位相差板を、容易に製造可能な製造方法が提供できる。
【図面の簡単な説明】
【図１】本発明の位相差板の例を示す概略図である。
【図２】本発明の位相差板を用いた円偏光板の基本的な構成を示す模式図である。
【図３】本発明の位相差板を用いた円偏光板の層構成の一例を示す概略断面図である。
【図４】本発明の位相差板を用いた円偏光板の層構成の他の例を示す概略断面図である。
【符号の説明】
Ｓ　　　透明支持体
Ｇ　　　保護膜
Ｐ　　　偏光膜
Ａ　　　第１の光学異方性層
Ｂ　　　第２の光学異方性層
ｓ　　　透明支持体の長手方向
ａ　　　第１の光学異方性層の遅相軸
ｂ　　　第２の光学異方性層の遅相軸
ｐ　　　偏光膜の透過軸
ｃ１　　棒状液晶性化合物
ｃ２　　棒状液晶性化合物[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an optical compensation sheet and a retardation plate that can be used in an optical element such as a liquid crystal cell of a liquid crystal display element. In particular, the present invention relates to a retardation plate effective as a λ / 4 plate used for a reflection type liquid crystal display device, an optical disk writing pickup, or an antireflection film.
[0002]
[Prior art]
Retardation plates, especially λ / 4 plates, have a great many applications and have already been used in practice. Conventional techniques capable of achieving λ / 4 in a wide wavelength region include a method of laminating two polymer films having optical anisotropy (see, for example, Patent Documents 1 and 2), and an optical anisotropy including a liquid crystalline compound. There is a method of providing at least two layers (for example, see Patent Documents 3 to 6). However, in the method of laminating two polymer films having optical anisotropy, in order to adjust the optical orientation (optical axis and slow axis) of the two polymer films, two kinds of polymer films are provided in a predetermined manner. It is necessary to cut the angle and paste the resulting chips together. If a phase difference plate is manufactured by bonding chips, the process is complicated, the quality is likely to deteriorate due to axial misalignment, the yield decreases, the cost increases, and deterioration due to contamination is likely to occur. In addition, it is difficult for the polymer film to strictly adjust the retardation value required for the λ / 4 plate. On the other hand, there is a method of providing a broadband λ / 4 plate more easily by providing at least two optically anisotropic layers containing a liquid crystalline compound (see, for example, Patent Documents 7, 8, and 9).
[0003]
However, the liquid crystal alignment film used in the above documents cannot easily and stably perform the tilt alignment of the rod-like liquid crystalline compound. It has been found that problems such as peeling of the optically anisotropic layer and the alignment film occur when the retardation plate is used for a long period of time or when the usage environment changes. As a method for solving this problem, there is a method in which a polymerizable group is introduced into the alignment film and is adhered to the optically anisotropic layer by chemical bonding (see, for example, Patent Document 10). However, when a rod-like liquid crystalline compound having a liquid crystal phase near room temperature is used, when there are few polymerizable groups in the liquid crystalline molecule, or when it is desired to increase the refractive index anisotropy, the method of Patent Document 10 is introduced. In addition, it has been newly found that problems such as peeling occur during long-term storage.
[0004]
[Patent Document 1]
JP-A-10-68816
[Patent Document 2]
JP-A-10-90521
[Patent Document 3]
JP 2000-206331 A
[Patent Document 4]
JP 2001-4837 A
[Patent Document 5]
JP 2001-21720 A
[Patent Document 6]
Japanese Patent Laid-Open No. 2001-91741
[Patent Document 7]
JP 2001-4837 A
[Patent Document 8]
JP 2001-21720 A
[Patent Document 9]
JP 2000-206331 A
[Patent Document 10]
JP 9-152509 A
[0005]
[Problems to be solved by the invention]
As a result of intensive studies by the present inventors, the above problem is that when the liquid crystal phase temperature is low, the chemical bond between the alignment film, the liquid crystal compound, and the liquid crystal compound is not a sufficient bond by the conventional method. It was found that this was the cause.
The object of the present invention is to provide excellent adhesion between the alignment film and the optically anisotropic layer, even when it has an optically anisotropic layer composed of a rod-like liquid crystalline compound having a liquid crystal phase at room temperature. Another object of the present invention is to provide a manufacturing method capable of easily manufacturing a retardation film having weather resistance.
[0006]
[Means for Solving the Problems]
The problems of the present invention have been solved by the following means.
[1] At least one layer in which a transparent support, an alignment film composed of a polymer having a polymerizable group, and a photocurable rod-like liquid crystalline compound are fixed in a state of being aligned substantially horizontally with respect to the alignment film surface. A method for producing a retardation plate having an optically anisotropic layer, comprising a high-temperature light irradiation step of performing light irradiation at a temperature of 60 ° C. or higher and 130 ° C. or lower.
[2] A first optically anisotropic layer in which the photocurable rod-like liquid crystalline compound that is in direct contact with the alignment film is fixed by polymerization so as to be aligned substantially horizontally with respect to the alignment film surface is formed. The method of manufacturing a retardation plate according to [1], wherein the first step is the high temperature light irradiation step, or the high temperature light irradiation step is performed after the first step.
[3] After the step of applying a composition containing a photocurable rod-like liquid crystalline compound to the surface of the alignment film, the high-temperature light irradiation step is performed to cure the photocurable rod-like liquid crystalline compound, The optically curable liquid crystalline compound forms an optically anisotropic layer fixed in a state of being aligned substantially horizontally with respect to the alignment film surface, and the adhesion between the optically anisotropic layer and the alignment film is increased. The method for producing a retardation plate according to [1] or [2], which is improved.
[0007]
[4] The composition containing the photocurable rod-like liquid crystalline compound applied to the surface of the alignment film is irradiated with light at a temperature of less than 60 ° C. to cure the photocurable rod-like liquid crystalline compound, and the light After the low temperature light irradiation step for forming the optically anisotropic layer in which the curable liquid crystalline compound is fixed in a state of being aligned substantially horizontally with respect to the alignment film surface, the high temperature light irradiation step is performed, The method for producing a retardation plate according to [1] or [2], wherein adhesion between the isotropic layer and the alignment film is improved.
[5] The composition containing the photocurable liquid crystalline compound applied to the surface of the alignment film or the surface above the alignment film is irradiated with light to cure the photocurable liquid crystalline compound, and the alignment state A first light irradiation step of forming the first optically anisotropic layer by fixing to a composition, and a composition containing a photocurable liquid crystalline compound applied to the surface of the first optically anisotropic layer A second light irradiation step of curing the photocurable liquid crystalline compound by light irradiation and fixing in an oriented state to form the second optically anisotropic layer, wherein the first and second The method for producing a retardation plate according to [1] or [2], wherein at least one of the light irradiation steps is the high-temperature light irradiation step.
[6] A composition containing a photocurable liquid crystalline compound applied to the surface of the alignment film or the surface above the alignment film is irradiated with light at a temperature of less than 60 ° C. A first light irradiation step of curing and fixing in an oriented state to form the first optically anisotropic layer; and a photocurable liquid crystalline compound applied to the surface of the first optically anisotropic layer. A second light irradiation step of irradiating the composition containing, curing the photocurable liquid crystalline compound, fixing in an oriented state, and forming the second optically anisotropic layer, The method for producing a retardation plate according to [1] or [2], wherein the high-temperature light irradiation step is performed after at least one of the first and second light irradiation steps.
[7] A retardation plate produced by the production method according to any one of [1] to [6].
[0008]
In the present specification, “substantially” with respect to an angle means that the angle is within a range of an exact angle of less than ± 5 °. The error from the exact angle is preferably less than 4 °, more preferably less than 3 °. Further, the “slow axis” means a direction in which the refractive index is maximized. Further, in the present specification, “substantially vertical” does not mean only strict vertical alignment, but includes an alignment having an average angle (average inclination angle) within a range of 50 ° to 90 °, “Substantially horizontal” does not mean only a strict horizontal orientation, but includes an orientation having an average angle (average inclination angle) in the range of 0 ° to 40 °.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
[Method for producing retardation plate]
The present invention provides a transparent support, an alignment film composed of a polymer having a polymerizable group, and at least one layer in which a photocurable rod-like liquid crystalline compound is fixed in a state of being aligned substantially horizontally with respect to the alignment film surface. A method for producing a phase difference plate, comprising the step of irradiating light at a temperature of 60 ° C. or higher and 130 ° C. or lower. By performing light irradiation in the temperature range, the polymerizable group in the alignment film and the polymerizable group in the optically anisotropic layer are chemically bonded, and the mutual adhesion is improved. As a result, it is possible to produce a high-quality retardation plate that does not cause defects such as peeling even when stored for a long time.
[0010]
In the manufacturing method of the present invention, the timing of performing light irradiation in the temperature range is not limited. For example, the step may be performed in order to cure the photocurable rod-like liquid crystalline compound, and an optically anisotropic layer is formed by the step, and the optically anisotropic layer and the alignment film are adhered to each other. Can be improved. Alternatively, the step may be carried out after the photocurable rod-like liquid crystalline compound is once cured to form an optically anisotropic layer. The latter embodiment is particularly effective when a liquid crystal compound exhibiting a liquid crystal phase at a relatively low temperature is used. By carrying out the polymerization of the photocurable liquid crystalline compound at a low temperature, the liquid crystalline compound can be stably fixed in a desired alignment state, and high refractive index anisotropy can be stably expressed. By performing the process, the adhesion between the alignment film and the optically anisotropic layer can be secured.
[0011]
The first aspect of the present invention is a method in which a transparent support, an alignment film made of a polymer having a polymerizable group, and a photocurable rod-like liquid crystal compound are fixed in a state of being aligned substantially horizontally with respect to the alignment film surface. A method for producing a retardation plate having at least one optically anisotropic layer, wherein the photocurable rod-like liquid crystalline compound applied to the alignment film surface is irradiated with light at a temperature of 60 ° C. or higher and 130 ° C. or lower. The photocurable rod-like liquid crystalline compound is fixed in a state of being aligned substantially horizontally with respect to the alignment film surface by polymerization, and a retardation plate including a step of forming a first optically anisotropic layer is produced. Is the method.
In the second aspect of the present invention, a transparent support, an alignment film made of a polymer having a polymerizable group, and a photocurable rod-like liquid crystalline compound are fixed by polymerization in a state of being aligned substantially horizontally with respect to the alignment film surface. A method for producing a retardation plate having at least one optically anisotropic layer, wherein the photocurable rod-like liquid crystalline compound applied to the surface of the alignment film is irradiated with light at a temperature of less than 60 ° C. , A low-temperature light irradiation step of curing the photocurable rod-like liquid crystalline compound and forming an optically anisotropic layer fixed in a state where the photocurable liquid crystalline compound is aligned substantially horizontally with respect to the alignment film surface Thereafter, light is irradiated at a temperature of 60 ° C. or higher and 130 ° C. or lower to improve the adhesion between the optically anisotropic layer and the alignment film.
[0012]
In the first and second embodiments, by performing light irradiation in the temperature range, the polymerizable group in the alignment film and the polymerizable group in the optically anisotropic layer are chemically bonded to each other, so that the mutual adhesion is improved. improves. In the first aspect, the optically anisotropic layer can be formed by light irradiation in the temperature range, and the adhesion between the alignment film and the optically anisotropic layer can be improved. In the second aspect, the light irradiation in the temperature range is performed after forming the optically anisotropic layer, and contributes to the improvement in adhesion between the alignment film and the optically anisotropic layer. The latter embodiment is particularly effective when a liquid crystal compound exhibiting a liquid crystal phase at a relatively low temperature is used.
[0013]
The third aspect of the present invention is a method in which a transparent support, an alignment film composed of a polymer having a polymerizable group, and a photocurable rod-like liquid crystalline compound are fixed in a state of being aligned substantially horizontally with respect to the alignment film surface. A method for producing a retardation plate having at least one optically anisotropic layer, comprising a photocurable liquid crystalline compound applied to the surface of the alignment film or the surface above the alignment film A first light irradiation step of forming a first optically anisotropic layer by irradiating an object with light, curing the photocurable liquid crystalline compound and fixing the alignment state; The composition containing the photocurable liquid crystalline compound applied to the surface of the light-sensitive layer is irradiated with light to cure the photocurable liquid crystalline compound and fix the alignment state to the second optical anisotropy. A second light irradiation step for forming a layer, and the first and second light irradiation steps. At least one of a phase difference plate manufacturing method is a step of performing light irradiation at 60 ° C. or higher 130 ° C. or less.
[0014]
According to a fourth aspect of the present invention, a transparent support, an alignment film composed of a polymer having a polymerizable group, and a photocurable rod-like liquid crystalline compound are fixed by polymerization in a state of being aligned substantially horizontally with respect to the alignment film surface. A method for producing a retardation plate having at least one optically anisotropic layer, comprising a photocurable liquid crystalline compound applied to the surface of the alignment film or the surface above the alignment film A first light irradiation step of irradiating the product with light at a temperature of less than 60 ° C. to cure the photocurable liquid crystalline compound and fixing the alignment state to form the first optically anisotropic layer; The composition containing the photocurable liquid crystalline compound applied to the surface of one optically anisotropic layer is irradiated with light to cure the photocurable liquid crystalline compound and fix it in an alignment state. A second light irradiation step of forming an optically anisotropic layer of the first and After at least one of the second light irradiation step, a method of manufacturing a phase difference plate is irradiated with light at a temperature 60 ° C. or higher 130 ° C. or less.
[0015]
In the third and fourth aspects, by performing light irradiation in the temperature range, the polymerizable group in the alignment film and the polymerizable group in the optically anisotropic layer are chemically bonded, and the mutual adhesion is improves. In the third aspect, the optically anisotropic layer can be formed by light irradiation in the temperature range, and the adhesion between the alignment film and the optically anisotropic layer can be improved. In the fourth aspect, the light irradiation in the temperature range is carried out after forming the optically anisotropic layer, and contributes to improving the adhesion between the alignment film and the optically anisotropic layer. This is particularly effective when a liquid crystal compound exhibiting a liquid crystal phase at a low temperature is used. In addition, as in the third and fourth embodiments, in the case of producing a retardation plate having an embodiment in which at least two optically anisotropic layers made of a polymerizable liquid crystal compound are directly laminated, the directly laminated optical films are produced. It also contributes to improving the adhesion between the anisotropic layers.
[0016]
In the present invention, a photocurable rod-like liquid crystalline compound is used for at least one of the optically anisotropic layers, but the photocurable liquid crystalline compound of any structure is used for the other layers. Alternatively, an optically anisotropic layer formed by a method other than photocuring or an optically anisotropic layer formed of a material other than the photocurable liquid crystalline compound may be included. In addition, the production method of the present invention is applied to the production of a retardation plate composed of one or two optically anisotropic layers, as well as a retardation having three or more optically anisotropic layers. It can be widely applied to the production of plates.
[0017]
An example of the production method of the present invention includes the following steps.
(1) A step of applying and drying a composition containing a polymer having a polymerizable group for the alignment film in the side chain on the transparent support and forming the alignment film,
(2) A step of rubbing the surface of the alignment film,
(3) A step of applying a composition containing a photocurable liquid crystalline compound on the rubbing surface of the alignment film to form a film,
(4) A step of polymerizing and curing the photocurable liquid crystalline compound in the film obtained in (3) to form an optically anisotropic layer.
When producing a phase difference plate having one optically anisotropic layer, in the step (4) and / or after the step (4), simultaneously with light irradiation, 60 ° C. or more and 130 ° C. or less. Heating.
[0018]
A retardation plate having two or more optically anisotropic layers can be produced by performing the following step (5 ′) and subsequent steps after the step (4).
(5 ') a step of rubbing the surface of the optically anisotropic layer obtained in (4),
(6 ′) A step of repeating the above (3) to (5 ′) one or more times to form one or more optically anisotropic layers on the optically anisotropic layer formed in (4).
Of the step (4) performed twice or more, at least once, at the same time as the light irradiation, heating at 60 ° C. or more and 130 ° C. or less is performed to cure the photocurable liquid crystalline compound, thereby forming an optically anisotropic layer. Form. Alternatively, after the formation of any of the optically anisotropic layers, heating at 60 ° C. to 130 ° C. is performed simultaneously with light irradiation.
[0019]
Details of each step will be described below.
[Transparent support]
In the present invention, a transparent support is used. The transparent support means a support having a light transmittance of 80% or more. Further, the wavelength dispersion of the transparent support is preferably small, and specifically, the ratio of Re400 / Re700 is preferably less than 1.2. Further, the transparent support preferably has a small optical anisotropy. Specifically, the in-plane retardation (Re) is preferably 20 nm or less, and more preferably 10 nm or less. Furthermore, the in-plane retardation change caused by environmental changes is preferably 20 nm or less, and more preferably 10 nm or less.
[0020]
The transparent support is preferably a polymer film. Examples of the polymer include cellulose ester, polycarbonate, polysulfone, polyethersulfone, polyacrylate and polymethacrylate. Cellulose esters are preferred, acetyl cellulose is more preferred, and triacetyl cellulose is most preferred. In particular, when triacetyl cellulose is used, one having an acetylation degree of 60.25 to 61.50 is preferable. The polymer film is preferably formed by a solvent cast method.
[0021]
In this invention, it is preferable to apply | coat an optically anisotropic layer continuously using a long roll-shaped support body. After forming the optically anisotropic layer, it can be cut into the required size. The thickness of the transparent support is preferably 20 to 500 μm, and more preferably 40 to 200 μm. In addition, in order to improve the adhesion between the transparent support and the layer (adhesive layer, horizontal alignment film, vertical alignment film or optically anisotropic layer) provided thereon, surface treatment (eg, glow discharge treatment) is applied to the transparent support. , Corona discharge treatment, ultraviolet (UV) treatment, flame treatment, saponification treatment) may be carried out, or an adhesive layer (undercoat layer) may be provided on the transparent support. The surface treatment is preferably saponification treatment.
[0022]
[Alignment film]
In the present invention, it is preferable to use an alignment film in order to align the liquid crystalline compound. The alignment film may be an organic compound (for example, ω-triconic acid) formed by rubbing treatment of an organic compound (preferably a polymer), oblique deposition of an inorganic compound, formation of a layer having a micro group, or Langmuir-Blodgett method (LB film). , Dioctadecyldimethylammonium chloride, methyl stearylate, etc.). 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 process is carried out by rubbing the surface of the polymer layer several times in a certain direction with paper or cloth.
[0023]
The type of polymer used for the alignment film is determined according to the alignment (particularly the average tilt angle) of the liquid crystal compound.
In order to align the liquid crystal compound horizontally, a polymer that does not decrease the surface energy of the alignment film (ordinary alignment polymer) is used. Specific types of polymers are described in various documents about liquid crystal cells or optical compensation sheets. In the present invention, a polymer having a polymerizable group in the alignment film is used for the purpose of improving the adhesion between the optically anisotropic layer made of a liquid crystalline compound and the transparent support (alignment film). The polymerizable group can be introduced by introducing a repeating unit having a polymerizable group in the side chain or as a substituent of a cyclic group. It is more preferable to use an alignment film that forms a chemical bond with the liquid crystalline compound at the interface. Examples of such an alignment film include those described in JP-A-9-152509.
The thickness of the alignment film is preferably 0.01 to 5 μm, more preferably 0.05 to 1 μm.
[0024]
[Rubbing]
The rubbing treatment can be performed at a predetermined arbitrary angle with respect to the conveying direction of the long roll-shaped support. The angle of the rubbing direction with respect to the transport direction is preferably rubbed in the same direction or an oblique direction with respect to the transport direction. The angle in the oblique direction is preferably in the range of −45 degrees to +45 degrees.
The rubbing treatment can be performed by any method, but it is preferably performed by at least one rubbing roll. For example, on a stage that transports a long film in the transport direction, a rubbing roll is arranged at an arbitrary angle with respect to the transport direction of the long film, and the rubbing roll is rotated while transporting the film in the transport direction. The alignment film surface of the transparent support can be rubbed. It is preferable to provide a mechanism that can freely adjust the angle formed by the rubbing roll and the moving direction of the stage. The rubbing roll refers to a roll having an appropriate rubbing cloth material attached to the surface.
[0025]
[Optically anisotropic layer made of liquid crystalline compound]
In the present invention, a photocurable liquid crystalline compound is used for forming the optically anisotropic layer. As the photocurable liquid crystalline compound, a photocurable rod-like liquid crystal compound or a photocurable discotic liquid crystalline compound having a polymerizable group is preferable, and at least one optically anisotropic layer (preferably adjacent to the alignment film). In the formation of the optically anisotropic layer, a photocurable rod-like liquid crystalline compound is used. Examples of the rod-like liquid crystalline compounds include azomethines, azoxys, cyanobiphenyls, cyanophenyl esters, benzoic acid esters, cyclohexanecarboxylic acid phenyl esters, cyanophenylcyclohexanes, cyano-substituted phenylpyrimidines, alkoxy-substituted phenylpyrimidines. , Phenyldioxanes, tolanes and alkenylcyclohexylbenzonitriles are preferably used. In addition to the above low-molecular liquid crystalline molecules, high-molecular liquid crystalline molecules can also be used. As the polymer liquid crystal, those in which a rod-like liquid crystal is bonded to a polymer chain in a pendant shape are particularly preferable, and are included in the category of a rod-like liquid crystalline compound in this specification.
[0026]
A particularly preferred low-molecular photocurable rod-like liquid crystal compound (hereinafter sometimes referred to as “polymerizable rod-like liquid crystal compound”) includes a compound represented by the following formula (I).
Formula (I)
Q¹-L¹-Cy¹-L²-(Cy²-L³)_n-Cy³-L⁴-Q²
Where Q¹And Q²Each independently represents a polymerizable group, L¹And L⁴Are each independently a divalent linking group, L²And L³Are each independently a single bond or a divalent linking group, and Cy¹, Cy²And Cy³Are each independently a divalent cyclic group, and n is 0, 1 or 2.
[0027]
The polymerizable rod-like liquid crystal compound will be further described below.
Where Q¹And Q²Are each independently a polymerizable group. The polymerization reaction of the polymerizable group is preferably addition polymerization (including ring-opening polymerization) or condensation polymerization. In other words, the polymerizable group is preferably a functional group capable of addition polymerization reaction or condensation polymerization reaction. Examples of polymerizable groups are shown below.
[0028]
[Chemical 1]

[0029]
In the formula (I), L¹And L⁴Are each independently a divalent linking group. L¹And L⁴Are each independently -O-, -S-, -CO-, -NR²It is preferably a divalent linking group selected from the group consisting of-, a divalent chain group, a divalent cyclic group, and combinations thereof. R above²Is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom.
[0030]
The example of the bivalent coupling group which consists of a combination is shown below. Here, the left side is Q (Q¹Or Q²), The right side is Cy (Cy¹Or Cy³).
L-1: —CO—O—divalent chain group —O—
L-2: -CO-O-divalent chain group -O-CO-
L-3: —CO—O—divalent chain group —O—CO—O—
L-4: -CO-O-divalent chain group -O-divalent cyclic group-
L-5: -CO-O-divalent chain group -O-divalent cyclic group -CO-O-
L-6: -CO-O-divalent chain group -O-divalent cyclic group -O-CO-
L-7: -CO-O-divalent chain group-O-divalent cyclic group-divalent chain group-
L-8: -CO-O-divalent chain group -O-divalent cyclic group -divalent chain group -CO-O-
L-9: -CO-O-divalent chain group -O-divalent cyclic group -divalent chain group -O-CO-
[0031]
L-10: —CO—O—divalent chain group—O—CO—divalent cyclic group—
L-11: -CO-O-divalent chain group -O-CO-divalent cyclic group -CO-O-
L-12: -CO-O-divalent chain group -O-CO-divalent cyclic group -O-CO-
L-13: —CO—O—Divalent chain group—O—CO—Divalent cyclic group—Divalent chain group—
L-14: -CO-O-divalent chain group -O-CO-divalent cyclic group -divalent chain group -CO-O-
L-15: -CO-O-divalent chain group-O-CO-divalent cyclic group-divalent chain group-O-CO-
L-16: —CO—O—divalent chain group—O—CO—O—divalent cyclic group—
L-17: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -CO-O-
L-18: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -O-CO-
L-19: —CO—O—Divalent chain group—O—CO—O—Divalent cyclic group—Divalent chain group—
L-20: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -divalent chain group -CO-O-
L-21: -CO-O-divalent chain group -O-CO-O-divalent cyclic group -divalent chain group -O-CO-
[0032]
In the above formula, the divalent chain group means an alkylene group, a substituted alkylene group, an alkenylene group, a substituted alkenylene group, an alkynylene group or a substituted alkynylene group. An alkylene group, a substituted alkylene group, an alkenylene group and a substituted alkenylene group are preferred, and an alkylene group and an alkenylene group are more preferred.
The alkylene group may have a branch. The alkylene group preferably has 1 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom.
The alkenylene group may have a branch. The alkenylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkylene part of the substituted alkylene group is the same as the above alkylene group. Examples of the substituent include a halogen atom.
The alkynylene group may have a branch. The alkynylene group preferably has 2 to 12 carbon atoms, more preferably 2 to 10 carbon atoms, and most preferably 2 to 8 carbon atoms.
The alkynylene part of the substituted alkynylene group is the same as the above alkynylene group. Examples of the substituent include a halogen atom.
Specific examples of the divalent chain group include ethylene, trimethylene, propylene, butamethylene, 1-methyl-butamethylene, pentamethylene, hexamethylene, octamethylene, 2-butenylene, 2-butynylene and the like.
[0033]
The definition and examples of the divalent cyclic group are described later in Cy.¹, Cy²And Cy³Definitions and examples are the same.
R²Is preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, and most preferably a hydrogen atom.
[0034]
L²Or L³Are each independently a single bond or a divalent linking group. L²And L³Are each independently -O-, -S-, -CO-, -NR₂It is preferably a divalent linking group or a single bond selected from the group consisting of-, a divalent chain group, a divalent cyclic group, and combinations thereof. R above²Is an alkyl group having 1 to 7 carbon atoms or a hydrogen atom, preferably an alkyl group having 1 to 4 carbon atoms or a hydrogen atom, more preferably a methyl group, an ethyl group or a hydrogen atom, Most preferably, it is a hydrogen atom. L for a divalent chain group and a divalent cyclic group¹And L⁴It is synonymous with the definition of
[0035]
In the formula (I), n is 0, 1 or 2. If n is 2, then two L³May be the same or different and the two Cy²May be the same or different. n is preferably 1 or 2, and more preferably 1.
[0036]
In formula (I), Cy¹, Cy²And Cy³Are each independently a divalent cyclic group.
The ring contained in the cyclic group is preferably a 5-membered ring, a 6-membered ring, or a 7-membered ring, more preferably a 5-membered ring or a 6-membered ring, and most preferably a 6-membered ring. The ring contained in the cyclic group may be a condensed ring. However, it is more preferably a monocycle than a condensed ring. The ring contained in the cyclic group may be any of an aromatic ring, an aliphatic ring, and a heterocyclic ring. Examples of the aromatic ring include a benzene ring and a naphthalene ring. Examples of the aliphatic ring include a cyclohexane ring. Examples of the heterocyclic ring include a pyridine ring and a pyrimidine ring. As the cyclic group having a benzene ring, 1,4-phenylene is preferable. As the cyclic group having a naphthalene ring, naphthalene-1,5-diyl and naphthalene-2,6-diyl are preferable. The cyclic group having a cyclohexane ring is preferably 1,4-cyclohexylene. As the cyclic group having a pyridine ring, pyridine-2,5-diyl is preferable. The cyclic group having a pyrimidine ring is preferably pyrimidine-2,5-diyl.
[0037]
The cyclic group may have a substituent. Examples of the substituent include a halogen atom, a cyano group, a nitro group, an alkyl group having 1 to 5 carbon atoms, a halogen-substituted alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. , An alkylthio group having 1 to 5 carbon atoms, an acyloxy group having 2 to 6 carbon atoms, an alkoxycarbonyl group having 2 to 6 carbon atoms, a carbamoyl group, and an alkyl-substituted carbamoyl group having 2 to 6 carbon atoms And an acylamino group having 2 to 6 carbon atoms.
[0038]
Although the specific example of the photocurable rod-shaped liquid crystalline compound which can be used for this invention below is shown, this invention is not limited by these.
[0039]
[Chemical 2]

[0040]
[Chemical 3]

[0041]
[Formula 4]

[0042]
[Chemical formula 5]

[0043]
In the present invention, a photocurable discotic liquid crystalline compound can be used as the photocurable liquid crystalline compound. The discotic liquid crystalline compound is preferably oriented substantially perpendicularly to the polymer film surface (average inclination angle in the range of 50 to 90 degrees). The discotic liquid crystalline compounds are disclosed in various documents (C. Destrade et al., Mol. Crysr. Liq. Cryst., Vol. 71, page 111 (1981); edited by the Chemical Society of Japan, Quarterly Chemical 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 the discotic liquid crystalline compound is described in JP-A-8-27284. In order to fix the discotic liquid crystalline compound by polymerization, it is necessary to bond a polymerizable group as a substituent to the discotic core of the discotic liquid crystalline compound. 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. That is, the photocurable discotic liquid crystalline compound is preferably a compound represented by the following formula (II).
Formula (II)
D (-LP)_n
In the formula, D is a discotic core, L is a divalent linking group, P is a polymerizable group, and n is an integer of 4 to 12.
[0044]
Preferred specific examples of the discotic core (D), the divalent linking group (L) and the polymerizable group (P) in the formula (II) are (D1) described in JP-A No. 2001-4837, respectively. To (D15), (L1) to (L25), and (P1) to (P18), and the contents described in the publication can be preferably used.
[0045]
These photocurable liquid crystalline compounds are fixed in an aligned state by polymerization to constitute an optically anisotropic layer. The liquid crystalline compound is preferably fixed in a substantially uniformly aligned state.
In the case of a photocurable rod-like liquid crystalline compound, it is preferable to substantially horizontally (homogeneously) align. Substantially horizontal means that the average angle (average inclination angle) between the major axis direction of the rod-like liquid crystal compound and the surface of the optically anisotropic layer is in the range of 0 ° to 40 °. The rod-like liquid crystalline compound may be aligned obliquely, or may be gradually changed (hybrid alignment). Even in the case of oblique alignment or hybrid alignment, the average inclination angle is preferably 0 ° to 40 °.
In the case of a photocurable discotic liquid crystalline compound, it is preferable to substantially align it vertically. Substantially perpendicular means that the average angle (average tilt angle) between the disc surface of the discotic liquid crystalline compound and the surface of the optically anisotropic layer is in the range of 50 ° to 90 °. The discotic liquid crystalline compound may be oriented obliquely or may be changed so that the inclination angle gradually changes (hybrid orientation). Even in the case of oblique orientation or hybrid orientation, the average inclination angle is preferably 50 ° to 90 °.
[0046]
In the case of producing a retardation plate having an adjacent optically anisotropic layer, the adjacent lower optically anisotropic layer can function as an alignment film for the optically anisotropic layer formed thereon. However, when the optically anisotropic layer functions as an alignment film of the optically anisotropic layer formed thereon, it contains a modified polyvinyl alcohol having a hydrocarbon group having 9 or less carbon atoms together with the liquid crystalline compound. It is preferable that an optically anisotropic layer is formed using the composition to be formed, and then the surface of the optically anisotropic layer is rubbed to form an upper optically anisotropic layer.
[0047]
The modified polyvinyl alcohol having a hydrocarbon group having 9 or less carbon atoms used together with the liquid crystal compound will be described.
A preferable modified polyvinyl alcohol is represented by the following formula (PX).
(PX)-(VAl)_x-(HyD)_y-(VAc)_z−
In the formula, VAl is a repeating unit of vinyl alcohol, HyD is a repeating unit having a hydrocarbon group having 9 or less carbon atoms, VAc is a vinyl acetate repeating unit, and x is 20 to 95% by mass ( Preferably it is 25-90 mass%), y is 2-98 mass% (preferably 10-80 mass%), z is 0-30 mass% (preferably 2-20 mass%).
[0048]
The hydrocarbon group contained in HyD is an aliphatic group, an aromatic group, or a combination thereof. The aliphatic group may be cyclic, branched or linear. The aliphatic group is preferably an alkyl group (which may be a cycloalkyl group) or an alkenyl group (which may be a cycloalkenyl group). The hydrocarbon group may have a substituent. The hydrocarbon group has 1 to 9 carbon atoms, and preferably 1 to 8 carbon atoms. Preferred examples of HyD are represented by the following formulas (HyD-I) and (HyD-II).
[0049]
[Chemical 6]

[0050]
Where L¹Are —O—, —CO—, and —SO.₂A divalent linking group selected from-, -NH-, an alkylene group, an arylene group, and combinations thereof;²Is a single bond, or -O-, -CO-, -SO₂A divalent linking group selected from-, -NH-, an alkylene group, an arylene group, and combinations thereof;¹And R²Are hydrocarbon groups each having 9 or less carbon atoms. Examples of divalent linking groups formed by the above combinations are shown below.
[0051]
L1: -O-CO-
L2: -O-CO-alkylene group -O-
L3: -O-CO-alkylene group -CO-NH-
L4: -O-CO-alkylene group -NH-SO₂-Arylene group-O-
L5: -Arylene group -NH-CO-
L6: -Arylene group -CO-O-
L7: -Arylene group -CO-NH-
L8: -Arylene group -O-
L9: -O-CO-NH-arylene group -NH-CO-
[0052]
Specific examples of HyD are shown below.
[0053]
[Chemical 7]

[0054]
The degree of polymerization of the modified polyvinyl alcohol is preferably 200 to 5000, and preferably 300 to 3000. The molecular weight of the polymer is preferably 9000 to 200000, and more preferably 13000 to 130,000. Two or more kinds of polymers may be used in combination.
[0055]
Specific examples of preferable modified polyvinyl alcohol are shown below, but the present invention is not limited thereto.
PX-1 :-( VAl)₂₁-(HyD-13)₇₇-(VAc)₂−
PX-2 :-( VAl)₁₄-(HyD-13)₈₄-(VAc)₂−
PX-3 :-( VAl)₂₁-(HyD-16)₇₇-(VAc)₂−
PX-4 :-( VAl)₃₄-(HyD-15)₆₄-(VAc)₂−
PX-5 :-( VAl)₂₉-(HyD-12)₆₉-(VAc)₂−
PX-6 :-( VAl)₄₆-(HyD-14)₅₂-(VAc)₂−
PX-7 :-( VAl)₂₁-(HyD-2)₇₇-(VAc)₂−
PX-8 :-( VAl)₁₇-(HyD-8)₈₅-(VAc)₂−
PX-9 :-( VAl)₂₁-(HyD-13)₇₇-(VAc)₂−
PX-10 :-( VAl)₄₆-(HyD-9)₅₂-(VAc)₂−
[0056]
The amount of the modified polyvinyl alcohol added is preferably 0.05% by mass to 10% by mass with respect to the liquid crystalline compound added by the control agent. More preferably, it is 0.1 mass-5 mass%.
[0057]
The modified polyvinyl alcohol may be used in combination with a condensing agent. As the condensing agent, a compound having an isocyanate group or a formyl group at the terminal is preferable. Specific compounds are listed below, but are not limited thereto.
[0058]
Poly (1,4-butanediol), isophorone diisocyanate terminated
Poly (1,4-butanediol), tolylene 2,4-diisocyanate terminated
Poly (ethylene adipate), tolylene 2,4-diisocyanate terminated
Poly (propylene glycol), tolylene 2,4-diisocyanate terminated,
1,6-diisocyanatohexane
1,8-diisocyanate octane
1,12-diisocyanatododecane
Isophorone diisocyanate
Glioquizal
[0059]
[Air interface side orientation control additive]
In the homogeneous alignment (horizontal alignment), the rod-like liquid crystalline compound tends to be tilted (tilt) aligned on the air interface side while being horizontal on the alignment film side. In order to suppress this property, it is preferable to use an additive for alignment control, and it is particularly preferable to use an additive represented by the following formula (V).
General formula (V)
(Hb-L²−)_nB¹
In the formula (V), Hb represents an aliphatic group having 6 to 40 carbon atoms or an aliphatic substituted oligosiloxanoxy group having 6 to 40 carbon atoms. Hb is preferably an aliphatic group having 6 to 40 carbon atoms, and is a fluorine-substituted aliphatic group having 6 to 40 carbon atoms or a branched aliphatic group having 6 to 40 carbon atoms. More preferably, it is most preferably a fluorine-substituted alkyl group having 6 to 40 carbon atoms or a branched alkyl group having 6 to 40 carbon atoms.
[0060]
The aliphatic group is preferably a chain aliphatic group rather than a cyclic aliphatic group. The chain aliphatic group may have a branch. The number of carbon atoms in the aliphatic group is preferably 7 to 35, more preferably 8 to 30, further preferably 9 to 25, and most preferably 10 to 20.
Aliphatic groups include alkyl groups, substituted alkyl groups, alkenyl groups, substituted alkenyl groups, alkynyl groups and substituted alkynyl groups. An alkyl group, a substituted alkyl group, an alkenyl group and a substituted alkenyl group are preferred, and an alkyl group and a substituted alkyl group are more preferred.
Examples of the substituent of the aliphatic group include a halogen atom, hydroxyl group, cyano group, nitro group, alkoxy group, substituted alkoxy group (for example, oligoalkoxy group), alkenyloxy group (for example, vinyloxy), acyl group (for example, , Acryloyl, methacryloyl), acyloxy groups (eg, acryloyloxy, benzoyloxy), sulfamoyl groups, aliphatic substituted sulfamoyl groups and epoxyalkyl groups (eg, epoxyethyl). As the substituent, a halogen atom is preferable, and a fluorine atom is more preferable. In the fluorine-substituted aliphatic group, the ratio of the fluorine atom replacing the hydrogen atom of the aliphatic group is preferably 50 to 100%, more preferably 60 to 100%, and 70 to 100%. More preferably, it is more preferably 80 to 100%, and most preferably 85 to 100%.
[0061]
The number of carbon atoms of the aliphatic-substituted oligosiloxanoxy group is preferably 7 to 35, more preferably 8 to 30, further preferably 9 to 25, and 10 to 20. Is most preferred. The aliphatic substituted oligosiloxanoxy group is represented by the following formula.
R¹-(Si (R²)₂-O)_q−
Where R¹Represents a hydrogen atom, hydroxyl or an aliphatic group; R²Represents a hydrogen atom, an aliphatic group or an alkoxy group; and q represents an integer of 1 to 12. R¹And R²Are preferably a chain aliphatic group rather than a cyclic aliphatic group. The chain aliphatic group may have a branch. The number of carbon atoms in the aliphatic group is preferably 1 to 12, more preferably 1 to 8, still more preferably 1 to 6, and particularly preferably 1 to 4.
R¹And R²The aliphatic group represented by each includes an alkyl group, a substituted alkyl group, an alkenyl group, a substituted alkenyl group, an alkynyl group, and a substituted alkynyl group. An alkyl group, a substituted alkyl group, an alkenyl group and a substituted alkenyl group are preferred, and an alkyl group and a substituted alkyl group are more preferred.
R¹And R²Each of the aliphatic groups represented by formula (1) may have a substituent, and examples of the substituent include a halogen atom, a hydroxyl group, a cyano group, a nitro group, an alkoxy group, a substituted alkoxy group (for example, an oligo group). Alkoxy group), alkenyloxy group (eg, vinyloxy), acyl group (eg, acryloyl, methacryloyl), acyloxy group (eg, acryloyloxy, benzoyloxy), sulfamoyl group, aliphatic substituted sulfamoyl group and epoxyalkyl group (eg, Epoxyethyl).
[0062]
R²The alkoxy group represented by may have a cyclic structure or a branch. The number of carbon atoms of the alkoxy group is preferably 1 to 12, more preferably 1 to 8, still more preferably 1 to 6, and still more preferably 1 to 4.
An example of Hb is shown below.
[0063]
Hb1: n-C₁₆H₃₃−
Hb2: n-C₂₀H₄₁−
Hb3: n-C₆H₁₃-CH (n-C₄H₉) -CH₂-CH₂−
Hb4: n-C₁₂H₂₅−
Hb5: n-C₁₈H₃₇−
Hb6: n-C₁₄H₂₉−
Hb7: n-C₁₅H₃₁−
Hb8: n-C₁₀H₂₁−
Hb9: n-C₁₀H₂₁-CH (n-C₄H₉) -CH₂-CH₂−
Hb10: n-C₈F₁₇−
[0064]
Hb11: n-C₈H₁₇−
Hb12: CH (CH₃)₂-{C₃H₆-CH (CH₃)}₃-C₂H₄−
Hb13: CH (CH₃)₂-{C₃H₆-CH (CH₃)}₂-C₃H₆-C (CH₃) = CH-CH₂−
Hb14: n-C₈H₁₇-CH (n-C₆H₁₃) -CH₂-CH₂−
Hb15: n-C₆H₁₃-CH (C₂H₅) -CH₂-CH₂−
Hb16: n-C₈F₁₇-CH (n-C₄F₉) -CH₂−
Hb17: n-C₈F₁₇-CF (n-C₆F₁₃) -CF₂-CF₂−
Hb18: n-C₃F₇-CF (CF₃) -CF₂−
Hb19: Si (CH₃)₃-{Si (CH₃)₂-O}₆-O-
Hb20: Si (OC₃H₇) (C₁₆F₃₃) (C₂H₄-SO₂-NH-C₈F₁₇-O-
[0065]
In the formula (V), L²Represents a single bond or a divalent linking group. The divalent linking group is -alkylene group-, -fluorine-substituted alkylene group-, -O-, -S-, -CO-, -NR-, -SO.₂It is preferably a group selected from the group consisting of-and combinations thereof. R is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. L^1ARepresents -alkylene group-, -O-, -S-, -CO-, -NR-, -SO.₂More preferably, it is a divalent linking group selected from the group consisting of-and combinations thereof. R is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and a hydrogen atom or carbon number of 1 Most preferred is an alkyl group of ˜12.
The alkylene group or the fluorine-substituted alkylene group preferably has 1 to 40 carbon atoms, more preferably 1 to 30, more preferably 1 to 20, and more preferably 1 to 15. Furthermore, it is preferable and it is most preferable that it is 1-12.
Below, L²An example of The left side is bound to Hb, the right side is B¹To join.
[0066]
L10: Single bond
L11: -O-
L12: -O-CO-
L13: -CO-C₄H₈-O-
L14: -O-C₂H₄-OC₂H₄-O-
L15: -S-
L16: -N (n-C₁₂H₂₅) −
L17: -SO₂-N (n-C₃H₇) -CH₂CH₂-O-
L18: -O- {CF (CF₃) -CF₂-O}₃-CF (CF₃) −
[0067]
In the formula (V), n represents an integer of 2 to 12. n is preferably an integer of 2 to 9, more preferably an integer of 2 to 6, further preferably 2, 3 or 4, and preferably 3 or 4. Most preferred.
[0068]
In the formula (V), B¹Is an n-valent group having an excluded volume effect comprising at least three cyclic structures. B¹Is preferably an n-valent group represented by the following formula (Va).
General formula (Va)
(-Cy¹-L³−)_nCy²
In the formula (Va), Cy¹Represents a divalent cyclic group. Cy¹Preferably represents a divalent aromatic hydrocarbon group or a divalent heterocyclic group, and more preferably represents a divalent aromatic hydrocarbon group.
The divalent aromatic hydrocarbon group means an arylene group and a substituted arylene group.
Examples of the arylene group include a phenylene group, an indenylene group, a naphthylene group, a fluorenylene group, a phenanthrenylene group, an anthrylene group, and a pyrenylene group. A phenylene group and a naphthylene group are preferred.
Examples of the substituent of the substituted arylene group include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group, methoxyethoxy group), an aryloxy group (for example, Phenoxy group), arylazo group (for example, phenylazo group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group), alkylamino group (for example, methylamino group, propylamino group), acyl group (for example, acetyl group) , Propanoyl group, octanoyl group, benzoyl group), acyloxy group (for example, acetoxy group, pivaloyloxy group, benzoyloxy group), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl group, sulfamoyl group and ureido group Is included.
When another aromatic hydrocarbon ring is bonded to the divalent aromatic hydrocarbon group as a substituent via a single bond, vinylene bond or ethynylene bond, a specific liquid crystal alignment promoting function is obtained as described above. It is done.
Hb-L²A group corresponding to-may be present as a substituent.
[0069]
Cy¹It is preferable that the bivalent heterocyclic group represented by these has a 5-membered, 6-membered or 7-membered heterocyclic ring. A 5-membered ring or a 6-membered ring is more preferable, and a 6-membered ring is most preferable. As the hetero atom constituting the heterocyclic ring, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocycle is generally an unsaturated heterocycle. An unsaturated heterocyclic ring having the most double bond is more preferable. Examples of heterocyclic rings include furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, pyrazoline Ring, pyrazolidine ring, triazole ring, triazane ring, tetrazole ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring included.
[0070]
The heterocycle may be condensed with other heterocycle, aliphatic ring or aromatic hydrocarbon ring. Examples of the condensed heterocyclic ring include benzofuran ring, isobenzofuran ring, benzothiophene ring, indole ring, indoline ring, isoindole ring, benzoxazole ring, benzothiazole ring, indazole ring, benzimidazole ring, chromene ring, chroman ring, Isochroman ring, quinoline ring, isoquinoline ring, cinnoline ring, phthalazine ring, quinazoline ring, quinoxaline ring, dibenzofuran ring, carbazole ring, xanthene ring, acridine ring, phenanthridine ring, phenanthroline ring, phenazine ring, phenoxazine ring, thianthrene ring , An indolizine ring, a quinolidine ring, a quinuclidine ring, a naphthyridine ring, a purine ring and a pteridine ring.
The divalent heterocyclic group may have a substituent. The example of a substituent is the same as the example of the substituent of a substituted arylene group.
A divalent heterocyclic group is a heteroatom (for example, a nitrogen atom of a piperidine ring) and L³Or (L³Is a single bond) Cyclic group at the center of the molecule (Cy²). Further, the bonded hetero atom may form an onium salt (eg, oxonium salt, sulfonium salt, ammonium salt).
[0071]
Cy¹And Cy to be described later²The annular structure may form a planar structure as a whole. When the annular structure as a whole forms a planar structure (that is, a disk-like structure), a specific liquid crystal alignment promoting function can be obtained as described above.
Below, Cy¹An example of Multiple Hb-L²When a group corresponding to-is bonded to a divalent aromatic hydrocarbon group or a divalent heterocyclic group, any one of them is Hb-L defined by the above formula²-And the remainder is a substituent of a divalent aromatic hydrocarbon group or a divalent heterocyclic group.
[0072]
[Chemical 8]

[0073]
[Chemical 9]

[0074]
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[0075]
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[0076]
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[0077]
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[0078]
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[0079]
In the formula (Va), L³Is a single bond or -alkylene group-, -alkenylene group-, -alkynylene group-, -O-, -S-, -CO-, -NR-, -SO.₂-And a divalent linking group selected from the group consisting of combinations thereof. R represents a hydrogen atom or an alkyl group having 1 to 30 carbon atoms. L³Are —O—, —S—, —CO—, —NR—, —SO.₂It is preferably a divalent linking group selected from the group consisting of-and combinations thereof. R is preferably a hydrogen atom or an alkyl group having 1 to 20 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 15 carbon atoms, and a hydrogen atom or an alkyl group having 1 to 15 carbon atoms. Most preferably, it is 12 alkyl groups.
The alkylene group preferably has 1 to 40 carbon atoms, more preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 15, and still more preferably 1 to 1. Most preferably, it is ~ 12.
The number of carbon atoms of the alkenylene group or alkynylene group is preferably 2 to 40, more preferably 2 to 30, further preferably 2 to 20, and further preferably 2 to 15. Preferably, it is 2-12.
Below, L³An example of Cy on the left¹And the right side is Cy²To join.
[0080]
L20: Single bond
L21: -S-
L22: —NH—
L23: —NH—SO₂-NH-
L24: -NH-CO-NH-
L25: -SO₂−
L26: -O-NH-
L27: -C≡C-
L28: -CH = CH-S-
L29: -CH₂-O-
L30: -N (CH₃) −
L31: -CO-O-
[0081]
In the formula (Va), n represents an integer of 2 to 12. n is preferably an integer of 2 to 9, more preferably an integer of 2 to 6, further preferably 2, 3 or 4, and preferably 3 or 4. Most preferred.
In the formula (Va), Cy²Is an n-valent cyclic group. Cy²Is preferably an n-valent aromatic hydrocarbon group or an n-valent heterocyclic group.
Cy²Examples of the aromatic hydrocarbon ring of the aromatic hydrocarbon group represented by the formula include a benzene ring, an indene ring, a naphthalene ring, a fluorene ring, a phenanthrene ring, an anthracene ring and a pyrene ring. A benzene ring and a naphthalene ring are preferable, and a benzene ring is particularly preferable.
Cy²The aromatic hydrocarbon group represented by may have a substituent. Examples of the substituent include an aliphatic group, an aromatic hydrocarbon group, a heterocyclic group, a halogen atom, an alkoxy group (for example, methoxy group, ethoxy group, methoxyethoxy group), an aryloxy group (for example, phenoxy group), Arylazo group (for example, phenylazo group), alkylthio group (for example, methylthio group, ethylthio group, propylthio group), alkylamino group (for example, methylamino group, propylamino group), arylamino group (for example, phenylamino group), Acyl group (for example, acetyl group, propanoyl group, octanoyl group, benzoyl group), acyloxy group (for example, acetoxy group, pivaloyloxy group, benzoyloxy group), hydroxyl group, mercapto group, amino group, carboxyl group, sulfo group, carbamoyl Group, sulfamoyl group and urei It includes groups.
[0082]
Cy²It is preferable that the heterocyclic group represented by has a 5-membered, 6-membered or 7-membered heterocyclic ring. A 5-membered ring or a 6-membered ring is more preferable, and a 6-membered ring is most preferable. As the hetero atom constituting the heterocycle, a nitrogen atom, an oxygen atom and a sulfur atom are preferable. The heterocycle is preferably an aromatic heterocycle. The aromatic heterocycle is generally an unsaturated heterocycle. An unsaturated heterocyclic ring having the most double bond is more preferable. Examples of the heterocyclic ring include furan ring, thiophene ring, pyrrole ring, pyrroline ring, pyrrolidine ring, oxazole ring, isoxazole ring, thiazole ring, isothiazole ring, imidazole ring, imidazoline ring, imidazolidine ring, pyrazole ring, Pyrazoline ring, pyrazolidine ring, triazole ring, furazane ring, tetrazole ring, pyran ring, thiyne ring, pyridine ring, piperidine ring, oxazine ring, morpholine ring, thiazine ring, pyridazine ring, pyrimidine ring, pyrazine ring, piperazine ring and triazine ring Is included. A triazine ring is preferred, and a 1,3,5-triazine ring is particularly preferred.
The heterocycle may be condensed with another heterocycle, an aliphatic ring or an aromatic hydrocarbon ring. However, monocyclic heterocycles are preferred.
Below, Cy²An example of
[0083]
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[0084]
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[0085]
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[0086]
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[0087]
The liquid crystal alignment accelerator includes the hydrophobic group (Hb) and linking group (L²) And groups with excluded volume effect (B¹). There are no particular restrictions on these combinations.
Examples of the liquid crystal alignment accelerator represented by the general formula (V) are shown below.
[0088]
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[0089]
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[0090]
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[0091]
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[0092]
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[0093]
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[0094]
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[0095]
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[0096]
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[0097]
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[0098]
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[0099]
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[0100]
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[0101]
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[0102]
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[0103]
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[0104]
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[0105]
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[0106]
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[0107]
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[0108]
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[0109]
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[0110]
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[0111]
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[0112]
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[0113]
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[0114]
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[0115]
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[0116]
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[0117]
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[0118]
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[0119]
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[0120]
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[0121]
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[0122]
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[0123]
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[0124]
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[0125]
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[0126]
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[0127]
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[0128]
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[0129]
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[0130]
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[0131]
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[0132]
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[0133]
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[0134]
In the present invention, the optically anisotropic layer is formed by rubbing the coating liquid obtained by dissolving the photocurable liquid crystalline compound, and optionally the modified polyvinyl alcohol, and the following polymerization initiator and other additives in a solvent. It is preferable to form by coating. As a solvent used for preparing the coating solution, 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 coating liquid can be applied by a known method (eg, extrusion coating method, direct gravure coating method, reverse gravure coating method, die coating method).
[0135]
[Fixation of alignment state of liquid crystalline compounds]
The aligned liquid crystalline compound is preferably fixed while maintaining the alignment state. The immobilization is preferably carried out by a polymerization reaction of a polymerizable group introduced into the liquid crystal compound. Examples of the photopolymerization initiator in the polymerization reaction include an α-carbonyl compound (described in US Pat. Nos. 2,367,661 and 2,367,670), acyloin ether (described in US Pat. No. 2,448,828), α-hydrocarbon substitution Aromatic acyloin compounds (described in US Pat. No. 2,722,512), polynuclear quinone compounds (described in US Pat. Nos. 3,046,127 and 2,951,758), combinations of triarylimidazole dimers and p-aminophenyl ketone (US Pat. No. 3,549,367) Acridine and phenazine compounds (JP-A-60-105667, US Pat. No. 4,239,850) and oxadiazole compounds (US Pat. No. 4,221,970).
The amount of the photopolymerization initiator used is preferably 0.01 to 20% by mass, more preferably 0.5 to 5% by mass, based on the solid content of the coating solution.
[0136]
Ultraviolet rays are preferably used for light irradiation for polymerization of the photocurable liquid crystalline compound. Irradiation energy is 20mJ / cm²~ 50J / cm²It is preferably 100 to 800 mJ / cm.²More preferably. In order to accelerate the photopolymerization reaction, light irradiation may be performed under heating conditions. In addition, reducing the oxygen concentration in the atmosphere at the time of light irradiation by nitrogen substitution or the like is also effective for promoting the reaction.
The thickness of the optically anisotropic layer is preferably 0.1 to 10 μm, and more preferably 0.5 to 5 μm.
[0137]
[Adhesion between alignment film and optically anisotropic layer]
In the present invention, in order to improve the adhesion between the alignment film and the optically anisotropic layer, the polymer having the above-described polymerizable group is used for the alignment film, and a step of simultaneously performing light irradiation and heating is performed. . The preferable conditions for light irradiation are the same as described above. Heating is 60 degrees or more, preferably 70 degrees or more, and more preferably 80 degrees or more. However, heating exceeding 130 degrees is not preferable because defects such as deformation of the support and a decrease in the alignment regulating force of the alignment film occur. The step of performing light irradiation and heating at the same time may be a step for curing a photocurable liquid crystalline compound, that is, for forming an optically anisotropic layer, or once the photocurable liquid crystalline property. After the compound is fixed by temporary polymerization to form an optically anisotropic layer, the optically anisotropic layer may be further laminated thereon. In the latter embodiment, when the temperature range of the liquid crystal phase of the photocurable liquid crystalline compound is on the low temperature side, an optically anisotropic layer can be formed by preliminary polymerization at a low temperature, which is not obtained by polymerization in a heated state. This is effective in that an optically anisotropic layer having a refractive index anisotropy can be formed. It is also advantageous in that it can prevent alignment disturbance due to unnecessary thermal polymerization.
[0138]
[Adhesion between optically anisotropic layers]
In order to improve the adhesion of the two optically anisotropic layers that are in direct contact with the photocurable liquid crystalline compound, in the polymerization step of forming the lower optically anisotropic layer, the outermost surface of the layer is polymerized. Incompletely, leaving a polymerizable group on the surface, and subsequently applying a layer containing a photocurable liquid crystalline compound on the optically anisotropic layer, followed by polymerization to obtain an optical anisotropy of the upper layer Form a layer. A chemical bond is formed between the lower and upper optically anisotropic layers, and adhesion is improved. As a method for incomplete polymerization of the outermost surface of the optically anisotropic layer, polymerization is performed in an atmosphere in which a radical quencher or the like is present (for example, an atmosphere having an oxygen concentration of 10% or more), light Methods such as reducing the irradiation amount can be raised, but are not limited thereto.
[0139]
[Optical properties of retardation plate]
In the retardation plate manufactured by the manufacturing method of the present invention, it is preferable that the optically anisotropic layer substantially achieves a phase difference of π or π / 2 at a specific wavelength. In order to achieve the phase difference π at the specific wavelength (λ), the retardation value of the polarizer measured at the specific wavelength (λ) may be adjusted to λ / 2, and the phase difference π / In order to achieve 2, the retardation value of the polarizer measured at a specific wavelength (λ) may be adjusted to λ / 4. For example, in a retardation plate having two optically anisotropic layers, it is preferable that one achieves a phase difference of π and the other achieves π / 2 at 550 nm, which is a substantially intermediate wavelength in the visible region. One optically anisotropic layer (first optically anisotropic layer) preferably has a retardation value measured at a wavelength of 550 nm of 240 to 290 nm, and more preferably 250 to 280 nm. The other optically anisotropic layer (second optically anisotropic layer) preferably has a retardation value measured at a wavelength of 550 nm of 110 to 145 nm, and more preferably 120 to 140 nm.
[0140]
The retardation value means an in-plane retardation value for light incident from the normal direction of the optically anisotropic layer. Specifically, it is a value defined by the following formula.
Retardation value (Re) = (nx−ny) × d
Where nx and ny are the in-plane main refractive indices of the optically anisotropic layer, and d is the thickness (nm) of the optically anisotropic layer.
[0141]
The thicknesses of the first and second optically anisotropic layers can be arbitrarily determined as long as each layer exhibits a desired retardation. For example, when the first and second optically anisotropic layers are formed by horizontally aligning the same rod-like liquid crystal compound, the thickness of the optically anisotropic layer having a phase difference of π is set as the phase difference. It is preferable to double the thickness of the optical anisotropy of π / 2. Although the preferable range of the thickness of each optically anisotropic layer varies depending on the type of liquid crystal compound used, it is generally 0.1 to 10 μm, more preferably 0.2 to 0.8 μm, 5-5 micrometers is further more preferable.
[0142]
[Configuration of retardation plate and circularly polarizing plate]
FIG. 1 is a schematic diagram showing a typical configuration of a retardation plate when a rod-like liquid crystalline compound is used. As shown in FIG. 1, in addition to the long transparent support (S) and the first optical anisotropic layer (A), the basic retardation plate further includes a second optical anisotropic layer. (B). The phase difference of the first optically anisotropic layer (A) is π. The retardation of the second optical anisotropic layer (B) is π / 2. The angle formed by the longitudinal direction of the transparent support (S) and the slow axis (a) of the first optically anisotropic layer (A) is 30 °. The angle (γ) between the slow axis (b) of the second optical anisotropic layer (B) and the slow axis (a) of the first optical anisotropic layer (A) is 60 °. The first optical anisotropic layer (A) and the second optical anisotropic layer (B) shown in FIG. 1 each contain a rod-like liquid crystalline compound (c1 and c2). The rod-like liquid crystal compounds c1 and c2 are horizontally aligned. The major axis direction of the rod-like liquid crystal compound corresponds to the slow axis (a and b) of the optically anisotropic layer.
[0143]
In FIG. 1, for convenience, the optically anisotropic layer A (having a phase difference of π) is located closer to the transparent support S, and the optically anisotropic layer B (positional phase) is located on the outer side thereof. Although the configuration of the retardation plate and the circularly polarizing plate having a phase difference of π / 2) is shown, a configuration in which the positions of the optically anisotropic layer A and the optically anisotropic layer B are interchanged may be preferable. Is a configuration in which the optically anisotropic layer A (having a phase difference of π) is located closer to the transparent support S, and the optically anisotropic layer B (having a phase difference of π / 2) is located outside thereof.
The same applies to FIG. 2 described later.
[0144]
[Circularly polarizing plate]
The retardation plate of the present invention is a λ / 4 plate used in a reflective liquid crystal display device, a λ / 4 plate used for a pickup for writing on an optical disk, or a λ / 4 plate used as an antireflection film. Can be used particularly advantageously. The λ / 4 plate is generally used as a circularly polarizing plate combined with a polarizing film. Therefore, if it is configured as a circularly polarizing plate in which a retardation plate and a polarizing film are combined, it can be easily incorporated into a device for use such as a reflective liquid crystal display device. 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 produced using a polyvinyl alcohol film.
[0145]
[Configuration of Circular Polarizing Plate]
FIG. 2 is a schematic diagram showing a typical configuration of a circularly polarizing plate having a retardation plate using a rod-like liquid crystal compound. In addition to the transparent support (S), the first optical anisotropic layer (A) and the second optical anisotropic layer (B) shown in FIG. P). The polarizing transmission axis (p) of the polarizing film has an angle formed by the longitudinal direction (s) of the transparent support (S) of 45 °, and the slow axis (a) of the polarizing transmission axis and the optically anisotropic layer (A). The angle between the slow axis (a) of the optically anisotropic layer (A) and the slow axis (b) of the optically anisotropic layer (B) is the same as in FIG. Is 60 °. The first optical anisotropic layer (A) and the second optical anisotropic layer (B) shown in FIG. 2 also contain rod-like liquid crystalline compounds (c1 and c2), respectively. The rod-like liquid crystal compounds (c1 and c2) are horizontally aligned. The major axis direction of the rod-like liquid crystal compounds (c1 and c2) corresponds to the in-plane slow axis (a and b) of the optically anisotropic layer (A and B).
[0146]
There is no restriction | limiting in particular about the polarizing film combined with the phase difference plate of this invention, The dye type polarizing film and polyene type polarizing film using an iodine type polarizing film, a dichroic dye can be used. The iodine polarizing film and the dye polarizing film are generally produced using a polyvinyl alcohol film. The polarizing film is preferably laminated so that the transmission axis of the polarizing film is 45 ° with respect to the longitudinal direction of the transparent support of the retardation plate of the present invention. If a polarizing film having a transmission axis of polarized light substantially in the direction of 45 ° with respect to the longitudinal direction (hereinafter referred to as 45 ° polarizing film) is used, the angle adjustment at the time of lamination becomes unnecessary, and the circularly polarizing plate of the present invention Can be easily produced. Since the transmission axis of the polarizing film made of a stretched film substantially coincides with the stretching direction, a 45 ° polarizing film can be produced by stretching the film in a direction of 45 ° with respect to the longitudinal direction. Such a polarizing film having a polarization transmission axis substantially in the 45 ° direction (hereinafter referred to as a 45 ° polarizing film) can be produced by the oblique stretching method described in JP-A-2002-86554. It can be produced with reference to the conditions described in columns 0009 to 0045, the configuration of the usable apparatus, and the like.
[0147]
In the 45 ° polarizing plate used in the present invention, the absorption axis of polarized light, that is, the stretching axis is inclined by 45 ° with respect to the longitudinal direction, and this angle is the absorption axis of the polarizing plate when bonded to the liquid crystal cell in the LCD, Since the angle coincides with the vertical or horizontal direction of the liquid crystal cell itself, oblique punching is not necessary in the punching process. Moreover, since the polarizing plate produced by the oblique stretching method is straight along the longitudinal direction, and can be manufactured by slitting along the longitudinal direction without punching, the productivity is remarkably excellent. Yes.
[0148]
The polarizing film produced by the oblique stretching method can be used as it is for the retardation plate of the present invention as a polarizing plate, but a polarizing plate having a protective film attached on both sides or one side is used. Is preferred. The type of protective film is not particularly limited, and cellulose esters such as cellulose acetate, cellulose acetate butyrate, and cellulose propionate, polycarbonate, polyolefin, polystyrene, polyester, and the like can be used. If the value is above a certain value, the polarization axis and the orientation axis of the protective film are obliquely shifted, so that the linearly polarized light changes to elliptically polarized light, which is not preferable. For this reason, it is preferable that the retardation of a protective film is low. For example, at 632.8 nm, it is preferably 10 nm or less, and more preferably 5 nm or less. In order to obtain such low retardation, the polymer used as the protective film is particularly preferably cellulose triacetate. Polyolefins such as ZEONEX, ZEONOR (both manufactured by Nippon Zeon Co., Ltd.) and ARTON (manufactured by JSR Co., Ltd.) are also preferably used. Other examples include non-birefringent optical resin materials as described in JP-A-8-110402 or JP-A-11-293116.
[0149]
The adhesive between the polarizing film and the protective layer is not particularly limited, and examples thereof include PVA resins (including modified PVA such as acetoacetyl group, sulfonic acid group, carboxyl group, oxyalkylene group) and boron compound aqueous solution. PVA resin is preferable. The thickness of the adhesive layer is preferably 0.01 to 10 μm, and particularly preferably 0.05 to 5 μm after drying.
[0150]
From the viewpoint of increasing the contrast of the liquid crystal display device, the polarizing plate used in the present invention preferably has a higher transmittance and a higher degree of polarization. The transmittance is preferably 30% or more at 550 nm, and more preferably 40% or more. The degree of polarization is preferably 95.0% or more at 550 nm, more preferably 99% or more, and particularly preferably 99.9% or more.
[0151]
As described above, the polarizing film generally has protective films on both sides, but in the present invention, the retardation plate of the present invention can function as a protective film on one side of the polarizing film. In the case of producing a circularly polarizing plate using a 45 ° polarizing film, the right and left circularly polarizing plates can be easily made separately by changing the way of superposition.
[Configuration of Circular Polarizing Plate]
FIG. 3 shows a schematic cross-sectional view of one embodiment of a circularly polarizing plate using the retardation plate of the present invention.
The circularly polarizing plate shown in FIG. 3 has a structure in which a 45 ° polarizing film P and a protective film G are laminated on the retardation plate of the present invention. The retardation plate is composed of optically anisotropic layers A and B (shown as one layer in the drawing) and a transparent support S. The phase difference plate is laminated so that the surface of the transparent support S on which the optically anisotropic layers A and B are not provided is directed to the 45 ° polarizing film P. In this configuration, the retardation plate also functions as a protective film for the 45 ° polarizing film P. FIG. 3 also shows the relationship among the longitudinal direction s of the transparent support S, the slow axes a and b of the optically anisotropic layers A and B, and the transmission axis p of the 45 ° polarizing film P.
[0152]
When the circularly polarizing plate of FIG. 3 is incorporated in a display device, the protective film P side is set to the display surface side (the direction indicated by the arrow in the figure indicates the viewing direction). The circularly polarizing plate obtained from the configuration of FIG. 3 is right circularly polarized light. In FIG. 3, the light incident from the direction of the arrow passes through the polarizing film P and the optically anisotropic layers A and B sequentially, and is emitted as right circularly polarized light.
[0153]
FIG. 4 shows a schematic cross-sectional view of another configuration of a circularly polarizing plate using the retardation plate of the present invention. The circularly polarizing plate shown in FIG. 4 has a configuration in which the positions of the protective film G and the retardation plate of the circularly polarizing plate shown in FIG. 3 are changed. From the lower side in FIG. 4, the protective film G, 45 ° polarizing film P, transparent The support S and optically anisotropic layers A and B are laminated. In the circularly polarizing plate having such a configuration, left circularly polarized light is obtained.
As described above, when the protective layer and the retardation plate are bonded to the 45 ° polarizing film, the right circularly polarized light and the left circularly polarized light can be manufactured simply by switching the upper and lower layers.
[0154]
When a protective film is used separately from the transparent support, it is preferable to use a cellulose ester film having high optical isotropy, particularly a triacetyl cellulose film, as the protective film.
[0155]
The circularly polarizing plate of the present invention is a broadband λ / 4 plate in which retardation values / wavelength values measured at wavelengths of 450 nm, 550 nm, and 650 nm are all in the range of 0.2 to 0.3. preferable. The retardation value / wavelength value is more preferably in the range of 0.21 to 0.29, further preferably in the range of 0.22 to 0.28, and 0.23 to 0.27. Is particularly preferably within the range of 0.24 to 0.26.
[0156]
【Example】
The present invention will be described more specifically with reference to the following examples. The materials, reagents, amounts and ratios, operations, etc. shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention is not limited to the following specific examples. .
[Example 1]
An optically isotropic triacetylcellulose film (acetylation degree 60.9%) having a thickness of 80 μm, a width of 680 mm, and a length of 500 m was used as a transparent support. After saponifying both surfaces of this transparent support, an alignment film coating solution having the following composition was continuously applied to one surface of the transparent support and dried to form an alignment film having a thickness of 1 μm. Next, a rubbing treatment was performed on the alignment film continuously in the direction of 30 ° to the left hand with respect to the longitudinal direction of the transparent support.
[0157]
Alignment film coating solution composition
The following modified polyvinyl alcohol: 4.0% by weight
Water water 72.5% by weight
Methanol methanol 23.3% by weight
Glutaraldehyde 0.2% by weight
[0158]
Embedded image

[0159]
On the alignment film, a coating solution having the following composition was continuously applied using a bar coater, dried and heated (alignment aging), and further irradiated with ultraviolet rays to form an optically anisotropic layer (A). Three types of optically anisotropic layers (A50, A60, and A80) were produced at temperatures of 50 ° C., 60 ° C., and 80 ° C. during the ultraviolet irradiation. The optically anisotropic layer had a slow axis in the direction of 30 ° with respect to the longitudinal direction of the transparent support. The film thickness of the three types of optically anisotropic layers (A50, A60 and A80) was adjusted so that the retardation value (Re550) at 550 nm was 265 nm. The film thicknesses were 2.0 μm, 2.2 μm, and 2.4 μm, respectively, and it became possible to reduce the film thickness by polymerization at a low temperature.
Coating liquid composition for optically anisotropic layer (A)
Rod-like liquid crystalline compound of the present invention (Exemplary Compound I-1) 20.1% by weight
Rod-like liquid crystalline compound of the present invention (Exemplary Compound I-4) 18.0% by weight
The following sensitizer (1): 0.4% by weight
The following photopolymerization initiator (1) 1.1% by weight
Exemplified compound (PX-8) in this specification: 0.4% by mass
Methyl ethyl ketone 60.0% by weight
[0160]
Sensitizer (1)
Embedded image

[0161]
Photopolymerization initiator (1)
Embedded image

[0162]
The rubbing treatment was continuously performed on the optically anisotropic layer (A) so as to be + 60 ° with respect to the slow axis of the optically anisotropic layer (A) and + 30 ° with respect to the longitudinal direction.
On the optically anisotropic layer (A50, A60 and A80) subjected to the rubbing treatment, a coating solution having the following composition is continuously applied using a bar coater, dried and heated (alignment aging), and further irradiated with ultraviolet rays. Then, an optically anisotropic layer (B) was formed to produce a retardation plate. Three types of optically anisotropic layers (B50, B60, B80) on the three types of optically anisotropic layers (A50, A60, A80), respectively, with the temperature at the time of ultraviolet irradiation being 50, 60, and 80 degrees. A total of nine types of retardation plates (A50-B50, A50-B60, A50-B80, A60-B50, A60-B60, A60-B80, A80-B50, A80-B60, A80-B80) are manufactured. did.
Coating liquid composition for optically anisotropic layer (B)
Rod-like liquid crystalline compound of the present invention (Exemplary Compound I-1) 20.1% by weight
Rod-like liquid crystalline compound of the present invention (Exemplary Compound I-4) 18.0% by weight
Sensitizer of Example (1) 0.4% by weight
Photopolymerization initiator of Example (1) 1.2% by weight
Example compound V- (27) of formula (V) 0.1% by weight
Methyl ethyl ketone 60.0% by weight
[0163]
A part of the phase difference plate A50-B50 was cut out and further irradiated with UV while being heated to 50 ° C, 60 ° C or 80 ° C. These three retardation plates were designated as A50-B50-50, A50-B50-60, and A50-B50-80, respectively.
The film thickness of the optically anisotropic layer (B) is such that when the slow axis of the polarizing plate is arranged at an angle of 45 degrees with respect to the longitudinal direction of the retardation plate and normal light is irradiated from the polarizing plate side, the polarizing plate, The light transmitted through the retardation plate was determined to be circularly polarized light.
[0164]
[Example 2]
A compound represented by the following formula was mixed at 1: 1 to prepare a polymerizable liquid crystal composition. The obtained polymerizable liquid crystal composition exhibited a nematic phase at room temperature, and the phase transition temperature from the nematic phase to the isotropic liquid phase was 46 ° C.
On the alignment film produced in the same manner as in Example 1, a coating solution having the following composition was continuously applied using a bar coater, dried and heated (orientation aging), and further irradiated with ultraviolet rays for optical properties. An isotropic layer (C) was formed. Two types of optically anisotropic layers (C40 and C60, respectively) were produced at temperatures of 40 ° C. and 60 ° C. during the ultraviolet irradiation.
Coating liquid composition for optically anisotropic layer (C)
Rod-like liquid crystalline compound (N1) 30.0% by weight
Rod-like liquid crystalline compound (N2) 30.0% by weight
Sensitizer (1) 0.3% by weight
Photopolymerization initiator (1) 1.0% by weight
Methyl ethyl ketone 38.7% by weight
[0165]
Rod-shaped liquid crystal compound (N1)
Embedded image

[0166]
Rod-shaped liquid crystal compound (N2)
Embedded image

[0167]
A part of the optically anisotropic layer C40 was cut out and further irradiated with UV while being heated to 50 ° C, 60 ° C, 130 ° C and 140 ° C. These three retardation plates were designated as C40-50, C40-60, C40-80, C40-130, and C40-140. However, it was found that C40-140 cannot be used as a retardation plate because the support is deformed and the orientation of the optically anisotropic layer is disturbed.
[0168]
[Adhesion test]
For each of the obtained retardation plates, a single-edged razor blade is cut into the surface of the optically anisotropic layer at an angle of 60 ° with respect to the surface, the width is 10 mm, and the depth slightly reaches the surface of the triacetylcellulose film. I made a notch. Apply commercially available cellophane tape across the slit and leave one end of the tape, rub it over and bond it well, hold the end of the unattached tape with your hand, pull it as hard as possible, and peel it off. The ratio of the area from which the cured film layer was peeled to the tape area applied from was evaluated as follows.
A: No peeling at all
B: The peeled area ratio was less than 30%
C: The peeled area ratio was 30 to less than 70%
D: The peeled area ratio was 70% or more.
The following table shows the adhesiveness, orientation, and thickness of the entire optically anisotropic layer A and B of the prepared retardation plate.
[0169]
[Table 1]

[0170]
From the above results, it was found that good adhesion can be obtained only when heating at 60 ° C. or higher is performed during light irradiation.
In addition, adhesion was improved when light irradiation was performed at 60 ° C. to 60 ° C. A retardation plate with a thin film thickness is obtained when cured at a low temperature, the optically anisotropic layers A and B are cured at 50 ° C., and then the sample is further irradiated with light, so that the film thickness is thin and the adhesion is sufficient. A phase difference plate was obtained.
In the optically anisotropic layer C, the transition temperature of the liquid crystal was low, and at 60 ° C., the liquid crystal was in the isotropic phase. For those cured at 40 ° C., sufficient adhesion can be obtained by irradiating light again at 60 ° C. or higher after orientation fixing. According to this method, sufficient adhesion can be obtained even when the liquid crystal phase temperature range is on the low temperature side. Can be obtained.
[0171]
【The invention's effect】
According to the present invention, when the liquid crystal layer uses a rod-like liquid crystalline compound near room temperature or when it is desired to increase the refractive index anisotropy, sufficient adhesion with the alignment film can be obtained, and during long-term storage, etc. In addition, it is possible to provide a manufacturing method capable of easily manufacturing a high-quality retardation plate that does not cause defects such as peeling.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an example of a retardation plate of the present invention.
FIG. 2 is a schematic diagram showing a basic configuration of a circularly polarizing plate using the retardation plate of the present invention.
FIG. 3 is a schematic cross-sectional view showing an example of a layer structure of a circularly polarizing plate using the retardation plate of the present invention.
FIG. 4 is a schematic cross-sectional view showing another example of the layer structure of a circularly polarizing plate using the retardation plate of the present invention.
[Explanation of symbols]
S transparent support
G Protective film
P Polarizing film
A 1st optically anisotropic layer
B Second optically anisotropic layer
s Longitudinal direction of transparent support
a Slow axis of the first optically anisotropic layer
b Slow axis of the second optically anisotropic layer
p: Transmission axis of polarizing film
c1 Rod-like liquid crystalline compound
c2 Rod-like liquid crystalline compound

Claims (7)

At least one optically anisotropic layer in which a transparent support, an alignment film composed of a polymer having a polymerizable group, and a photocurable rod-like liquid crystalline compound are fixed in a state of being aligned substantially horizontally with respect to the alignment film surface A method for producing a phase difference plate, comprising a high temperature light irradiation step of irradiating light at a temperature of 60 ° C. or higher and 130 ° C. or lower, which is a method for producing a phase difference plate having a crystalline layer. A first step of forming a first optically anisotropic layer fixed directly by polymerization in a state in which the photocurable rod-like liquid crystalline compound directly in contact with the alignment film is aligned substantially horizontally with respect to the alignment film surface. 2. The method of manufacturing a retardation plate according to claim 1, wherein the first step is the high temperature light irradiation step, or the high temperature light irradiation step is performed after the first step. After the step of applying a composition containing a photocurable rod-like liquid crystalline compound to the surface of the alignment film, the high-temperature light irradiation step is performed to cure the photocurable rod-like liquid crystalline compound, and the photocuring Forming an optically anisotropic layer fixed in a state where the liquid crystalline compound is aligned substantially horizontally with respect to the alignment film surface, and improving the adhesion between the optically anisotropic layer and the alignment film Item 3. A method for producing a retardation plate according to Item 1 or 2. The composition containing the photocurable rod-like liquid crystalline compound applied to the surface of the alignment film is irradiated with light at a temperature of less than 60 ° C. to cure the photocurable rod-like liquid crystalline compound, and the photocurable liquid crystal After the low-temperature light irradiation step for forming the optically anisotropic layer fixed in a state where the functional compound is aligned substantially horizontally with respect to the alignment film surface, the high-temperature light irradiation step is performed, and the optically anisotropic layer The method for producing a retardation plate according to claim 1, wherein adhesion between the alignment film and the alignment film is improved. The composition containing the photocurable liquid crystalline compound applied to the surface of the alignment film or the surface above the alignment film is irradiated with light to cure the photocurable liquid crystalline compound and fix it in the aligned state. A first light irradiation step for forming the first optically anisotropic layer, and a composition containing a photocurable liquid crystalline compound coated on the surface of the first optically anisotropic layer. A second light irradiation step of curing the photocurable liquid crystalline compound and fixing the alignment state to form the second optically anisotropic layer, wherein the first and second light irradiations are performed. The method for producing a retardation film according to claim 1, wherein at least one of the steps is the high-temperature light irradiation step. A composition containing a photocurable liquid crystalline compound applied to the surface of the alignment film or the surface above the alignment film is irradiated with light at a temperature of less than 60 ° C. to cure the photocurable liquid crystalline compound, A composition comprising a first light irradiation step for forming the first optically anisotropic layer fixed in an orientation state, and a photocurable liquid crystalline compound applied to the surface of the first optically anisotropic layer A second light irradiating step of irradiating the product with light to cure the photocurable liquid crystalline compound and fixing the alignment state to form the second optically anisotropic layer, The manufacturing method of the phase difference plate of Claim 1 or 2 which implements the said high temperature light irradiation process after at least one of a 2nd light irradiation process. The phase difference plate manufactured by the manufacturing method of any one of Claims 1-6.

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