JP2004250415A - Indane compound and nematic liquid crystal composition containing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a nematic liquid crystal composition having a high upper limit temperature (T<SB>→N</SB>) of a liquid crystal phase and a lower limit temperature (T<SB>N-1</SB>) of the liquid crystal phase and further having a wide liquid crystal phase temperature range, and an indane compound. <P>SOLUTION: The present invention provides a 5,6-difluoroindane-based compound represented by formula (I) (wherein R<SP>1</SP>is an alkyl group, an alkenyl group, or the like; A<SP>1</SP>is phenylene group, cyclohexyl group, or the like) and the nematic liquid crystal composition obtained by using the compound. The nematic liquid crystal composition is extremely useful for display elements, or the like, capable of corresponding also to use in the open air, because the composition has the wide liquid crystal phase temperature range. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

（式中Ｒ^１は、水素原子、炭素数１〜１５のアルキル基、少なくとも一つのハロゲンにより置換された炭素数１〜１５のアルキル基、炭素数２〜１５のアルケニル基又は少なくとも一つのハロゲンにより置換された炭素数２〜１５のアルケニル基を表し、これらの基中に存在する１個又は２個以上のＣＨ_２基はそれぞれ独立してＯ原子が相互に直接結合しないものとして −Ｏ−、−Ｓ−、−ＣＯ−、−ＣＯＯ−、−ＯＣＯ−又は−ＯＣＯ−Ｏ−により置き換えられても良く、
Ａ^１は、
（ａ） トランス−１，４−シクロへキシレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は −Ｏ− 及び又は −Ｓ− に置き換えられてもよい）
（ｂ） １，４−フェニレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は −Ｎ− に置き換えられてもよい）
（ｃ） １，４−シクロヘキセニレン、１，４−ビシクロ（２．２．２）オクチレン、ピペリジン−１，４−ジイル、ナフタレン−２，６−ジイル、デカヒドロナフタレン−２，６−ジイル及び１，２，３，４−テトラヒドロナフタレン−２，６−ジイル
からなる群より選ばれる基であり、上記の基（ａ）、基（ｂ）、基（ｃ）はＣＮ又はハロゲンで置換されていても良く、
ｎは、１又は２である。）で表される化合物。
【００１１】
また、本件発明は一般式（Ｉ）で表される化合物を１種又は２種以上を含有することを特徴とするネマチック液晶組成物を提供する。
【００１２】
更に、本件発明は一般式（Ｉ）で表される化合物及び一般式（ＩＩ）
【化６】

（式中、Ｒ^２及びＲ^３はそれぞれ独立的にＲ^１と同じ意味を表し、
Ｂ^１、Ｂ^２及びＢ^３はそれぞれ独立的に
（ａ） トランス−１，４−シクロへキシレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は −Ｏ− 及び又は −Ｓ− に置き換えられてもよい）
（ｂ） １，４−フェニレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は −Ｎ− に置き換えられてもよい）
（ｃ） １，４−シクロヘキセニレン、１，４−ビシクロ（２．２．２）オクチレン、ピペリジン−１，４−ジイル、ナフタレン−２，６−ジイル、デカヒドロナフタレン−２，６−ジイル及び１，２，３，４−テトラヒドロナフタレン−２，６−ジイル
からなる群より選ばれる基であり、上記の基（ａ）、基（ｂ）、基（ｃ）はＣＮ又はハロゲンで置換されていても良く、
ｏは０、１又は２であり、
Ｌ^１、Ｌ^２及びＬ^３はそれぞれ独立的に単結合、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−又は−Ｃ≡Ｃ−を表し、Ｌ^２及びＢ^３が複数存在する場合はそれらは同一でも良く異なっていても良い。）から選ばれる化合物及び／又は一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群
【００１３】
【化７】

【００１４】
（式中Ｒ^４はＲ^１と同じ意味を表し、Ｃ^１、Ｃ^２及びＣ^３はそれぞれ独立して、
（ｄ） トランス−１，４−シクロへキシレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は −Ｏ− 及び又は −Ｓ− に置き換えられてもよい）
（ｅ） １，４−フェニレン基（この基中に存在する１個のＣＨ_２基又は隣接していない２個以上のＣＨ_２基は −Ｎ− に置き換えられてもよい）
（ｆ） １，４−シクロヘキセニレン、１，４−ビシクロ（２．２．２）オクチレン、ピペリジン−１，４−ジイル、ナフタレン−２，６−ジイル、１，２，３，４−テトラヒドロナフタレン−２，６−ジイル及びデカヒドロナフタレン−２，６−ジイル
からなる群より選ばれる基であり、上記の基（ｄ）、基（ｅ）、基（ｆ）はＣＮ又はハロゲンで置換されていても良いが、１，２，３，４−テトラヒドロナフタレン−２，６−ジイルを表す場合、無置換であるか、少なくとも２つ以上のハロゲンによって置換されており、
Ｋ^１、Ｋ^２及びＫ^３はそれぞれ独立的に単結合、−ＣＨ_２ＣＨ_２−、−（ＣＨ_２）_４−、−ＯＣＨ_２−、−ＣＨ_２Ｏ−又は−Ｃ≡Ｃ−を表し、
Ｘ^１、Ｘ^３、Ｘ^４、Ｘ^５及びＸ^６はそれぞれ独立してＨ又はＦであり、
ｐ及びｑはそれぞれ独立して、０、１又は２であるが、ｐ及びｑの和は２以下であり、
Ｘ^２は、−Ｈ、−Ｆ、−Ｃｌ、ＣＮ、−ＣＦ_３、−ＣＨＦ_２、−ＯＣＨ_２Ｆ、−ＯＣＨＦ_２、−ＯＣＦ_３、−ＣＨ_２ＣＦ_３又はＲ^１と同じ定義である。）から選ばれる１種又は２種以上の化合物を含有することを特徴とするネマチック液晶組成物を提供する。
【００１５】
【発明の実施の形態】
以下に本発明の一例について説明する。
【００１６】
一般式（Ｉ）の化合物は以下のようにして製造することができる。一般式（ＩＶ）
【化８】

（式中、Ｒ及びｎは一般式（Ｉ）におけると同じ定義。）で表されるヘキサン酸誘導体をリチウムジイソプロピルアミド、リチウムヘキサメチルジシラジドやブチルリチウムなどを用いてエノール化した後、３，４−ジフルオロベンジルブロミドを反応させることにより一般式（Ｖ）
【００１７】
【化９】

（式中、Ｒ及びｎは一般式（Ｉ）におけると同じ定義。）で表されるエステルを得ることができる。このエステルを水酸化ナトリウムや水酸化カリウムを用いて加水分解し、得られたカルボン酸を塩化チオニル等を用いて酸塩化物に変換した後、塩化アルミニウムなどのルイス酸と反応させることによって、一般式（ＶＩ）
【００１８】
【化１０】

（式中、Ｒ及びｎは一般式（Ｉ）におけると同じ定義。）で表されるインダノン誘導体を得ることができる。これを水素化ホウ素ナトリウムや水素化アルミニウムリチウム等を用いて還元し、得られたアルコールをｐ−トルエンスルホン酸等の酸触媒存在下、加熱することによって、一般式（ＶＩＩ）
【００１９】
【化１１】

（式中、Ｒ及びｎは一般式（Ｉ）におけると同じ定義。）で表されるインデン誘導体を得ることができる。これをＰｄ−Ｃ、Ｒｈ−Ｃ、Ｐｔ−Ｃ、Ｐｄ（ＯＨ）_２等の金属触媒存在下、水素添加することによって、目的の一般式（Ｉ）で表される化合物を得ることができる。
【００２０】
本発明の液晶組成物において、第一成分として一般式（Ｉ）から選ばれる化合物を１種又は２種以上を含有するが、１種〜６種が好ましく、１種〜４種がより好ましく、１種〜３種が特に好ましい。
又、一般式（Ｉ）の含有率は５〜５０質量％の範囲であることが好ましく、１０〜４０質量％の範囲であることが特に好ましい。
【００２１】
一般式（Ｉ）において、Ｒ^１は、炭素数１〜１０のアルキル基又は炭素数２〜１０のアルケニル基が好ましく、未置換の直鎖状炭素数１〜８のアルキル基又は炭素数２〜８のアルケニル基がより好ましく、アルケニル基では以下の式（ａ）〜（ｅ）の構造がさらに好ましい。
【化１２】

（構造式は右端で環に連結しているものとする。）
【００２２】
Ａ^１はトランス−１，４−シクロへキシレン基、１，４−フェニレン基、３−フルオロ−１，４−フェニレン基又は３，５−ジフルオロ−１，４−フェニレン基が好ましく、トランス−１，４−シクロへキシレン基がより好ましく、ｎは１が好ましい。
【００２３】
一般式（Ｉ）で表される化合物は具体的な構造として次の化合物が特に好ましい。
【化１３】

（式中、Ｒ^１は、炭素原子数１〜８のアルキル基又はアルコキシル基を表す。）
これらの一般式（Ｉ）から選ばれる化合物のうち少なくとも１種以上の組成物の誘電率異方性（Δε）が１．５以上の化合物を含有することが好ましく、２以上を示すことがより好ましい。
【００２４】
第二成分として一般式（ＩＩ）、一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を１種又は２種以上を含有するが、１種〜２０種が好ましく、１種〜１５種がより好ましく、１種〜１０種が特に好ましい。また、これらの含有率は１０質量％〜８０質量％が好ましい。
【００２５】
一般式（ＩＩ）においてＲ^２及びＲ^３は、未置換の直鎖状炭素数１〜１５のアルキル基又は炭素数２〜１５のアルケニル基が好ましく、未置換の直鎖状炭素数１〜１０のアルキル基又は炭素数２〜１０のアルケニル基がより好ましく、未置換の直鎖状炭素数１〜８のアルキル基又は炭素数２〜６のアルケニル基が特に好ましく、アルケニル基では式（ａ）〜（ｅ）の構造がさらに好ましい。
また、Ｒ^２及びＲ^３は同一でも異なっていても良いが、同一分子中のＲ^２及びＲ^３は異なっていることがより好ましい。Ｌ^１及びＬ^２は、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ_２ＣＨ_２−、−Ｃ≡Ｃ−、−（ＣＨ_２）_４−又は単結合が好ましく、−ＣＨ_２ＣＨ_２−、−Ｃ≡Ｃ−又は単結合がより好ましく、−ＣＨ_２ＣＨ_２−又は単結合が特に好ましく、Ｌ^１及びＬ^２が複数存在する場合少なくとも一つは単結合であることが好ましい。ｏは、０又は１が好ましい。
【００２６】
Ｃ^１、Ｃ^２及びＣ^３はそれぞれ独立してトランス−１，４−シクロへキシレン基、１，４−フェニレン基、３−フルオロ−１，４−フェニレン基又は３，５−ジフルオロ−１，４−フェニレン基が好ましく、トランス−１，４−シクロへキシレン基又は１，４−フェニレン基より好ましく、Ｃ^１、Ｃ^２及びＣ^３の内少なくとも一つはトランス−１，４−シクロへキシレン基であることが好ましい。
【００２７】
一般式（ＩＩ）は以下の一般式（ＩＩａ）で示される構造が好ましい。
【化１４】

（式中、Ｒ^２及びＲ^３は炭素原子数１〜８のアルキル基又はアルコキシル基、炭素原子数２〜８のアルケニル基、炭素原子数３〜１６のアルケニルオキシ基を表し、Ｂ^３は１，４−フェニレン基又はトランス−１，４−シクロヘキシレン基を表し、ｒは０又は１を表す。）
一般式（ＩＩａ）の化合物の含有率は１０〜８０質量％の範囲であることが好ましい。
【００２８】
又、一般式（ＩＩ）は具体的な構造として以下の一般式で示される構造も好ましい。
【化１５】

（式中、Ｒ^５及びＲ^６はそれぞれ独立して炭素原子数１〜８のアルキル基又はアルコキシル基、炭素原子数２〜８のアルケニル基、炭素原子数３〜１６のアルケニルオキシ基を表す。）で示される構造が好ましい。
又、一般式（ＩＩ）から選ばれる化合物を１種又は２種以上を含有するが、１種〜６種が好ましく、１種〜４種が特に好ましい。
【００２９】
一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）においてＲ^４は、未置換の直鎖状炭素数１〜１５のアルキル基又は炭素数２〜１５のアルケニル基が好ましく、未置換の直鎖状炭素数１〜１０のアルキル基又は炭素数２〜１０のアルケニル基がより好ましく、未置換の直鎖状炭素数１〜８のアルキル基又は炭素数２〜６のアルケニル基が特に好ましく、アルケニル基では式（ａ）〜（ｅ）の構造がさらに好ましい。Ｋ^１、Ｋ^２及びＫ^３は、−ＣＯＯ−、−ＯＣＯ−、−ＣＨ_２ＣＨ_２−、−Ｃ≡Ｃ−、−（ＣＨ_２）_４−又は単結合が好ましく、−ＣＨ_２ＣＨ_２−、−Ｃ≡Ｃ−又は単結合がより好ましく、−ＣＨ_２ＣＨ_２−又は単結合が特に好ましく、Ｋ^１、Ｋ^２又はＫ^３が複数存在する場合少なくとも一つは単結合であることが好ましい。ｐ及びｑは、０又は１が好ましい。Ｃ^１、Ｃ^２及びＣ^３はそれぞれ独立してトランス−１，４−シクロへキシレン基、１，４−フェニレン基、３−フルオロ−１，４−フェニレン基又は３，５−ジフルオロ−１，４−フェニレン基が好ましく、トランス−１，４−シクロへキシレン基又は１，４−フェニレン基より好ましく、トランス−１，４−シクロへキシレン基が特に好ましい。
【００３０】
Ｘ^２は、−Ｈ、−Ｆ、−Ｃｌ、ＣＮ、−ＣＦ_３、−ＣＨＦ_２、−ＯＣＨ_２Ｆ、−ＯＣＨＦ_２、−ＯＣＦ_３、−ＣＨ_２ＣＦ_３又はＲ^１と同じ定義であるが、−Ｆ、−ＣＮ、−ＣＦ_３、−ＣＨＦ_２、−ＯＣＨ_２Ｆ、−ＯＣＨＦ_２、−ＯＣＦ_３が好ましく、Ｆが特に好ましい。
一般式（ＩＩＩａ）は具体的な構造として以下の一般式
【化１６】

【００３１】
【化１７】

【００３２】
【化１８】

【００３３】
【化１９】

（式中、Ｒ^７は炭素原子数１〜８のアルキル基又はアルコキシル基、炭素原子数２〜８のアルケニル基を表し、Ｘ^３及びＸ^４はそれぞれ独立してＨ又はＦを表し、Ｙ^４は−ＣＮ、−Ｆ、−Ｃｌ、−ＣＦ_３、−ＯＣＦ_３又は−ＯＣＨＦ_２を表す。）で示される構造が好ましく、以下の一般式（ＩＩＩａ−１）で示される構造も好ましい。
【００３４】
【化２０】

（式中、Ｒ^７は炭素原子数１〜８のアルキル基又はアルコキシル基、炭素原子数２〜８のアルケニル基を表し、Ｌ^５、Ｌ^６はそれぞれ独立して、−ＣＨ_２ＣＨ_２−、−ＣＨ＝ＣＨ−、−Ｃ≡Ｃ−、−（ＣＨ_２）_４−又は単結合を表し、環Ｉは１，４−フェニレン基又はトランス−１，４−シクロヘキシレン基を表し、Ｘ^６はＨ又はＦを表し、ｎは０又は１を表し、Ｙ^４は−ＣＮ、−Ｆ、−Ｃｌ、−ＣＦ_３、−ＯＣＦ_３又は−ＯＣＨＦ_２を表す。）
【００３５】
一般式（ＩＩＩｂ）は具体的な構造として以下の一般式
【化２１】

【００３６】
【化２２】

（式中、Ｒ^７は炭素原子数１〜８のアルキル基又はアルコキシル基、炭素原子数２〜８のアルケニル基を表し、Ｙ^４は−ＣＮ、−Ｆ、−Ｃｌ、−ＣＦ_３、−ＯＣＦ_３又は−ＯＣＨＦ_２を表す。）で示される構造が好ましく、一般式（ＩＩＩｃ）は具体的な構造として以下の一般式
【００３７】
【化２３】

【００３８】
【化２４】

【００３９】
【化２５】

（式中、Ｒ^７は炭素原子数１〜８のアルキル基又はアルコキシル基、炭素原子数２〜８のアルケニル基を表し、Ｙ^４は−ＣＮ、−Ｆ、−Ｃｌ、−ＣＦ_３、−ＯＣＦ_３又は−ＯＣＨＦ_２を表す。）
【００４０】
一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を１種又は２種以上を含有するが、１種〜１０種が好ましく、２種〜８種が特に好ましい。
【００４１】
本発明のネマチック液晶組成物は一般式（Ｉ）から選ばれる化合物を１種又は２種以上を含有し、さらに一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を１種又は２種以上含有することが好ましく、一般式（Ｉ）から選ばれる化合物を１種又は２種以上を含有し、さらに一般式（ＩＩ）から選ばれる化合物を１種又は２種以上含有することも好ましい。
【００４２】
一般式（Ｉ）の化合物を１種又は２種以上含有し、さらに一般式（ＩＩ）の化合物を１種又は２種以上含有し、さらに一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を少なくとも１種又は２種以上含有することが好ましく、少なくとも１種以上の一般式（ＩＩ）の化合物を含有し、さらに一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を少なくとも２種以上含有することが好ましい。
【００４３】
又、一般式（ＩＩＩａ）から選ばれる化合物を１種又は２種以上含有し、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を１種又は２種以上含有することが好ましく、一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群の含有率が１０〜５０質量％の範囲であることが好ましい。
【００４４】
一般式（Ｉ）で表される化合物を１種又は２種以上を含有し、その含有率が５〜５０質量％の範囲で、なおかつ一般式（ＩＩａ）の化合物を１種又は２種以上を含有し、その含有率が１０〜６０質量％の範囲で、なおかつ一般式（ＩＩＩａ）、一般式（ＩＩＩｂ）及び一般式（ＩＩＩｃ）からなる群から選ばれる化合物を１種又は２種以上を含有し、その含有率が５〜５０質量％の範囲であることが特に好ましい。
【００４５】
本発明のネマチック液晶組成物は広い液晶相温度範囲（液晶相下限温度と液晶相上限温度の差の絶対値）を有するが、液晶相温度範囲が８０℃以上であることが好ましく、９０℃以上であることがより好ましく、１００℃以上が特に好ましい。また、液晶相上限温度は７０℃以上が好ましく、８０℃以上がより好ましい。さらに、液晶相下限温度は−２０℃以下が好ましく、−３０℃以下がより好ましい。
【００４６】
上記ネマチック液晶組成物はＡＭ−ＬＣＤやＳＴＮ−ＬＣＤに有用であるがＡＭ−ＬＣＤに特に有用であり、透過型あるいは反射型の液晶表示素子に用いることができる。本発明のネマチック液晶組成物は、上記の化合物以外に、通常のネマチック液晶、スメクチック液晶、コレステリック液晶などを含有していてもよい。
【００４７】
【実施例】
以下、実施例を挙げて本発明を更に詳述するが、本発明はこれらの実施例に限定されるものではない。また、以下の実施例及び比較例の組成物における「％」は『質量％』を意味する。
【００４８】
実施例中、測定した特性は以下の通りである。
Ｔ_Ｎ−Ｉ ：ネマチック相−等方性液体相転移温度（℃）を液晶相上限温度とする
Ｔ_{→ Ｎ} ：固体相又はスメクチック相−ネマチック相転移温度（℃）を液晶相下限温度とする
ΔＴ ：ネマチック液晶相温度範囲、｜Ｔ_Ｎ−Ｉ − Ｔ_{→ Ｎ} ｜
Ｖｔｈ ：セル厚６μｍのＴＮ−ＬＣＤを構成した時のしきい値電圧（Ｖ）
Δε ：誘電異方性
Δｎ ：複屈折率
τｒ＝τｄ ：応答速度 （ｍｓ）
化合物記載に下記の略号を使用する。
末端のｎ（数字） Ｃ_ｎＨ_２ｎ＋１−
Ｃ トランス−１，４−シクロヘキシレン基
Ｐ １，４フェニレン基
Ｅ −ＣＯＯ−
ｅ −ＯＣＯ−
Ａ −ＣＨ_２ＣＨ_２−
ｔ −Ｃ≡Ｃ−
４ −ＣＨ_２ＣＨ_２ＣＨ_２ＣＨ_２−
ＣＮ −Ｃ≡Ｎ
Ｏｎ −ＯＣ_ｎＨ_２ｎ＋１
Ｆ −Ｆ
ｆ 末端基のオルト位に結合したＦ原子
ｎｄｍ− Ｃ_ｎＨ_２ｎ＋１−Ｃ＝Ｃ−（ＣＨ_２）_ｍ−１−
−Ｏ（ｄｍ）ｎ −Ｏ（ＣＨ２）ｍ−２−Ｃ＝Ｃ−ＣｎＨ２ｎ＋１
【００４９】
【化２６】

【００５０】
（実施例１） ５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インダン（Ｉ−１）の合成
【化２７】

【００５１】
（１−１） ２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸エチルの合成
ジイソプロピルアミン（４．８ ｇ）のテトラヒドロフラン（ＴＨＦ）（５０ ｍｌ）溶液に、−７８℃で１．５ Ｍブチルリチウム−ヘキサン溶液（３１ ｍｌ）を加え、−７８℃で３０分、０℃で１５分間撹拌した。−７８℃に冷却し、６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸エチル（１０ ｇ）のＴＨＦ（３０ ｍｌ）溶液を加えた。１時間撹拌した後、３，４−ジフルオロベンジルブロミド（１０ ｇ）のＴＨＦ（３０ ｍｌ）溶液を加え、３時間かけて、室温まで昇温した。反応液を１０％塩酸にあけ、酢酸エチルで抽出し、有機層を飽和食塩水で洗い、無水硫酸ナトリウムで乾燥後、濃縮した。残渣をシリカゲルカラムクロマトグラフィー（ヘキサン：酢酸エチル＝９：１）で精製し、２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸エチル（１５．２ ｇ）を得た。
【００５２】
（１−２） ２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸の合成
２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸エチル（１５ ｇ）に、エタノール（１００ ｍｌ）、水（４０ ｍｌ）、水酸化ナトリウム（９ ｇ）を加え、４時間加熱還流した。エタノール（約６０ ｍｌ）を減圧留去し、濃塩酸を加え、トルエンで抽出、濃縮し、２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸粗生成物（１２．５ ｇ）を得た。
【００５３】
（１−３） ５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インダノンの合成
２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸粗生成物（１２ ｇ）にジクロロメタン（２５ ｍｌ）と塩化チオニル（２０ ｍｌ）を加え、４時間加熱還流した。ジクロロメタンを常圧で留去し、塩化チオニルを減圧留去し、残渣にジクロロメタン（５０ ｍｌ）を加え、２−（３，４−ジフルオロフェニルメチル）−６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸塩化物のジクロロメタン溶液を調製した。これを、塩化アルミニウム（８ ｇ）のジクロロメタン（２０ ｍｌ）懸濁液に室温で３０分かけて滴下した。さらに２時間撹拌した後、反応液を氷冷下で１０％塩酸にあけた。有機層を無水硫酸ナトリウムで乾燥後、濃縮した。残渣をシリカゲルカラムクロマトグラフィー（ヘキサン：酢酸エチル＝２０：１）で精製し、５，６−ジフルオロ−２−（４−（トランス−４−プロピルシクロヘキシル）ブチル）インダノン粗生成物（８．２ ｇ、純度７０％）を得た。これをエタノールから再結晶し、５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インダノン（４．５ ｇ、純度９９％）を得た。この化合物は質量分析で、分子量３４８であった。
【００５４】
（１−４） ５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インデンの合成
５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インダノン（４．５ ｇ）のエタノール（５０ ｍｌ）溶液に、水素化ホウ素ナトリウム（２ ｇ）を加え、室温で１時間撹拌した。反応液を１０％塩酸にあけ、酢酸エチルで抽出し、有機層を飽和食塩水で洗い、無水硫酸ナトリウムで乾燥後、濃縮した。残渣にトルエン（１００ ｍｌ）とｐ−トルエンスルホン酸（１ ｇ）を加え、１５分間加熱還流した。反応液を室温に戻し、１０％塩酸と飽和食塩水で洗い、無水硫酸ナトリウムで乾燥後、濃縮した。残渣をシリカゲルカラムクロマトグラフィー（ヘキサン）で精製し、５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インデン（４ ｇ）を得た。この化合物は、質量分析で、分子量３３２であった。
【００５５】
（１−５） ５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インダンの合成
５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インデン（４ ｇ）に、エタノール（７０ ｍｌ）、酢酸エチル（３０ ｍｌ）と５％パラジウム−炭素（４５０ ｍｇ）を加え、水素雰囲気下で１時間撹拌した。反応液をセライトで濾過し、濾液を濃縮し、残渣をシリカゲルショートカラム（ヘキサン）で精製し、５，６−ジフルオロ−２−（４−（トランス−４−プロピルシクロヘキシル）ブチル）インダン（４ ｇ）を得た。さらにエタノールから再結晶して、５，６−ジフルオロ−２−［４−（トランス−４−プロピルシクロヘキシル）ブチル］インダン（４ ｇ、純度９９．８％）を得た。この化合物は、質量分析で、分子量３３４であった。
ＭＳ ｍ／ｚ ３３４ （Ｍ＋）
１Ｈ ＮＭＲ （ＣＤＣｌ_３） δ ０．９５ （ｔ， Ｊ ＝ ７ Ｈｚ， ３Ｈ）、１．２〜１．５ （ｍ， ２２Ｈ）、２．０ （ｍ， １Ｈ）、２．９ （ｄ， ４Ｈ）、６．８ （ｍ， ２Ｈ）
【００５６】
（実施例２） ５，６−ジフルオロ−２−｛４−［トランス−４−（トランス−４−プロピルシクロヘキシル）シクロヘキシル］ブチル｝インダンの合成
実施例１において、６−（トランス−４−プロピルシクロヘキシル）ヘキサン酸エチルに代えて６−（トランス−４−（トランス−４−プロピルシクロヘキシル）シクロヘキシル）ヘキサン酸エチルを出発原料として、同様な手順により５，６−ジフルオロ−２−｛４−［トランス−４−（トランス−４−プロピルシクロヘキシル）シクロヘキシル］ブチル｝インを得た。
【００５７】
（実施例３及び４） 液晶組成物の調整
以下に示すネマチック液晶組成物（Ｎｏ．１）及び（Ｎｏ．２）を調整しその物性値を測定し、その結果を表１に示す。
【表１】

【００５８】
表１に示すように、実施例３及び４のネマチック液晶組成物は、液晶相の下限温度（Ｔ_{→ Ｎ}）が高く、液晶相上限温度（Ｔ_Ｎ−Ｉ）が低く、広い液晶温度範囲を有することが解る。
このネマチック液晶組成物を用いて、表示品位の優れたＴＦＴ液晶表示素子を作成することができた。
【００５９】
（比較例１及び２）
比較例１及び２のネマチック液晶組成物を調整しその物性値を表２に示す。
【表２】

【００６０】
比較例１のネマチック液晶組成物は、比較的本願発明に近い構成を有するが、液晶相上限温度が劣っていることがわかる。液晶相上限温度を実施例の液晶組成物に近づけた比較例２の液晶組成物は液晶相上限温度では実施例１と同等であるが、今度は液晶相下限温度が大幅に上昇してしまっていることがわかる。
【００６１】
【発明の効果】
本発明のネマチック液晶組成物により、５，６−ジフルオロインダン系化合物を用いた、液晶相の下限温度が高く、液晶相上限温度が低く、液晶相温度範囲の広いネマチック液晶組成物を提供することが可能となった。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a nematic crystal composition useful as an electro-optical liquid crystal display material, a liquid crystal display device using the same, and an indane-based compound useful as a constituent material of the nematic liquid crystal composition.
[0002]
[Prior art]
In liquid crystal display elements such as twisted nematic, super twisted nematic or active matrix, especially in small and medium-sized portable liquid crystal display elements, display stability with respect to the operating temperature is an important point, and responsiveness and A liquid crystal material having a lower drive voltage capable of reducing power consumption, a drive voltage in a temperature range of -30 to 0 ° C. or 40 to 80 ° C., a sharpness, a desired frequency dependency of duty drive, and the like are smaller. It has been demanded.
[0003]
In particular, the liquid crystal phase temperature range (ΔT), which is the absolute value of the difference between the lower limit temperature of the liquid crystal phase (T _{→ N} ) and the upper limit temperature of the liquid crystal phase (T _NI ), takes advantage of the low power consumption characteristics of the liquid crystal display element. This is important because of increased use outdoors. However, with conventional material combinations, the liquid crystal phase temperature range can be expanded, but the threshold voltage and the response speed increase with this, so that a sufficient liquid crystal phase temperature range cannot be obtained at present. (See Patent Document 1).
Therefore, it has been desired to develop a liquid crystal composition having a wide liquid crystal phase temperature range without deteriorating various liquid crystal characteristics such as a response speed and a threshold voltage, or a liquid crystal material most suitable for this use.
[0004]
On the other hand, liquid crystal compounds having indan in the skeleton are already known, and some compounds have been disclosed (see Patent Document 2). However, although there are disclosures of compounds having fluorine atoms at the 5- and 6-positions of the indane ring, there is no disclosure as to what characteristics the compounds have when used as a nematic liquid crystal composition. In addition, a liquid crystal composition using an indane-based compound is already known, and specific examples of preferred compounds are disclosed (see Patent Document 3). However, the compounds disclosed herein do not have a fluorine atom at the 5- and 6-positions of the indane ring, and the substituent at the 2-position mainly has a special ring structure or non-ring structure. Moreover, the liquid crystal composition disclosed herein is a liquid crystal composition used for a ferroelectric liquid crystal display device, and there is no disclosure regarding a nematic liquid crystal composition.
[0005]
From the above, a nematic liquid crystal composition using a compound having a fluorine atom at the 5-position and the 6-position of the indane ring is not known, and a wide liquid crystal phase temperature range using a 5,6-difluoroindane-based compound is used. It has been desired to develop a nematic liquid crystal composition having excellent characteristics.
[0006]
[Patent Document 1]
JP 2001-11450 A (p. 6)
[Patent Document 2]
WO 94/18285 pamphlet (pages 26 to 31)
[Patent Document 3]
WO 99/19420 pamphlet (p. 30-35)
[0007]
[Problems to be solved by the invention]
An object of the present invention is to provide a 5,6-difluoroindan compound and a liquid crystal phase using the compound, which have a high minimum temperature (T _{→ N} ), a low maximum liquid crystal phase temperature (T _N−I ), and a low liquid crystal phase temperature. An object of the present invention is to provide a nematic liquid crystal composition having a wide range and the compound.
[0008]
[Means for Solving the Problems]
The present inventor studied a 5,6-difluoroindane compound and a nematic liquid crystal composition containing the same in order to solve the above problems, and as a result, completed the present invention.
[0009]
That is, the present invention provides the liquid crystal compounds described below.
[0010]
General formula (I)
Embedded image

(Wherein R ¹ is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, an alkyl group having 1 to 15 carbon atoms substituted by at least one halogen, an alkenyl group having 2 to 15 carbon atoms, or at least one halogen. Represents a substituted alkenyl group having 2 to 15 carbon atoms, wherein one or two or more CH ₂ groups present in each of these groups independently represent -O-, -S-, -CO-, -COO-, -OCO- or -OCO-O-,
A ¹ is,
(A) trans-1,4-one CH ₂ group or nonadjacent two or more CH ₂ groups existing in xylene group (in this group the cycloalkyl is replaced by -O- and or -S- May be)
(B) 1,4-phenylene group (one more CH ₂ groups not CH ₂ group or adjacent the present in this group may be replaced by-N-)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein the groups (a), (b) and (c) are substituted with CN or halogen. May be
n is 1 or 2. ).
[0011]
The present invention also provides a nematic liquid crystal composition comprising one or more compounds represented by the general formula (I).
[0012]
Furthermore, the present invention relates to a compound represented by the general formula (I) and a compound represented by the general formula (II):
Embedded image

(Wherein, R ² and R ³ each independently represent the same meaning as R ¹ ,
B ^{1, B 2} and ^{B 3} are each independently (a) trans-1,4-cyclohexylene group (not one CH ₂ group or adjacent present in this group two or more CH ₂ The group may be replaced by -O- and or -S-)
(B) 1,4-phenylene group (one more CH ₂ groups not CH ₂ group or adjacent the present in this group may be replaced by-N-)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein the groups (a), (b) and (c) are substituted with CN or halogen. May be
o is 0, 1 or 2;
L ¹ , L ² and L ³ each independently represent a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O— or —C≡C—, When a plurality of L ² and B ³ exist, they may be the same or different. And / or a group consisting of the general formula (IIIa), the general formula (IIIb) and the general formula (IIIc)
Embedded image

[0014]
(Wherein R ⁴ has the same meaning as R ^1, and C ¹ , C ² and C ³ each independently represent
(D) a trans-1,4-cyclohexylene group (in which one CH ₂ group or two or more non-adjacent CH ₂ groups are replaced by —O— and / or —S— May be)
(E) 1,4-phenylene group (one more CH ₂ groups not CH ₂ group or adjacent the present in this group may be replaced by-N-)
(F) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, 1,2,3,4-tetrahydro A group selected from the group consisting of naphthalene-2,6-diyl and decahydronaphthalene-2,6-diyl, wherein the groups (d), (e) and (f) are substituted with CN or halogen. However, when it represents 1,2,3,4-tetrahydronaphthalene-2,6-diyl, it is unsubstituted or substituted by at least two or more halogens,
K ¹ , K ² and K ³ each independently represent a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O— or —C≡C—,
X ¹ , X ³ , X ⁴ , X ⁵ and X ⁶ are each independently H or F;
p and q are each independently 0, 1 or 2, but the sum of p and q is 2 or less;
X ² _{is, -H, -F, -Cl, CN} , -CF 3, -CHF 2, -OCH 2 F, -OCHF 2, -OCF 3, is the same definition as _-CH 2 CF _3, or ^{R 1.} A) a nematic liquid crystal composition comprising one or more compounds selected from the group consisting of:
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, an example of the present invention will be described.
[0016]
The compound of the general formula (I) can be produced as follows. General formula (IV)
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(Wherein R and n have the same definitions as in the general formula (I)). After enolizing the hexanoic acid derivative represented by the general formula (I) using lithium diisopropylamide, lithium hexamethyldisilazide, butyllithium or the like, 3 By reacting 2,4-difluorobenzyl bromide with a compound of the general formula (V)
[0017]
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(Wherein R and n have the same definitions as in general formula (I)). This ester is hydrolyzed using sodium hydroxide or potassium hydroxide, and the resulting carboxylic acid is converted into an acid chloride using thionyl chloride or the like, and then reacted with a Lewis acid such as aluminum chloride to obtain an ester. Formula (VI)
[0018]
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(Wherein R and n have the same definitions as in general formula (I)). This is reduced using sodium borohydride, lithium aluminum hydride, or the like, and the obtained alcohol is heated in the presence of an acid catalyst such as p-toluenesulfonic acid to obtain a compound represented by the general formula (VII).
[0019]
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(Wherein R and n have the same definitions as in general formula (I)). By hydrogenating this in the presence of a metal catalyst such as Pd-C, Rh-C, Pt-C, and Pd (OH) ₂ , the desired compound represented by the general formula (I) can be obtained.
[0020]
In the liquid crystal composition of the present invention, one or more compounds selected from the general formula (I) are contained as the first component, but one to six are preferable, and one to four are more preferable. One to three are particularly preferred.
Further, the content of the general formula (I) is preferably in the range of 5 to 50% by mass, and particularly preferably in the range of 10 to 40% by mass.
[0021]
In the general formula (I), R ¹ is preferably an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, and an unsubstituted linear alkyl group having 1 to 8 carbon atoms or 2 to 2 carbon atoms. The alkenyl group of No. 8 is more preferable, and the structures of the following formulas (a) to (e) are more preferable in the alkenyl group.
Embedded image

(The structural formula is linked to the ring at the right end.)
[0022]
A ¹ is preferably a trans-1,4-cyclohexylene group, 1,4-phenylene group, 3-fluoro-1,4-phenylene group or 3,5-difluoro-1,4-phenylene group, and trans-1 , 4-cyclohexylene group is more preferable, and n is preferably 1.
[0023]
The compound represented by the general formula (I) is particularly preferably the following compound as a specific structure.
Embedded image

(In the formula, R ¹ represents an alkyl group or an alkoxyl group having 1 to 8 carbon atoms.)
It is preferable that at least one of the compounds selected from the general formula (I) contains a compound having a dielectric anisotropy (Δε) of 1.5 or more, more preferably 2 or more. preferable.
[0024]
The second component contains one or more compounds selected from the group consisting of general formula (II), general formula (IIIa), general formula (IIIb) and general formula (IIIc). Species are preferred, 1 to 15 are more preferred, and 1 to 10 are particularly preferred. Further, their content is preferably from 10% by mass to 80% by mass.
[0025]
In the general formula (II), R ² and R ³ are preferably an unsubstituted linear alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms. Is more preferable, and an unsubstituted linear alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 6 carbon atoms is particularly preferable. In the alkenyl group, the formula (a) Structures (a) to (e) are more preferable.
Further, R ² and R ³ may be the same or different, but R ² and R ³ in the same molecule are more preferably different. L ¹ and L ² are preferably —COO—, —OCO—, —CH ₂ CH ₂ —, —C≡C—, — (CH ₂ ) ₄ — or a single bond, and —CH ₂ CH ₂ —, —C ≡C— or a single bond is more preferred, —CH ₂ CH ₂ — or a single bond is particularly preferred, and when a plurality of L ¹ and L ² are present, at least one is preferably a single bond. o is preferably 0 or 1.
[0026]
C ¹ , C ² and C ³ are each independently a trans-1,4-cyclohexylene group, a 1,4-phenylene group, a 3-fluoro-1,4-phenylene group or a 3,5-difluoro-1, A 4-phenylene group is preferable, and a trans-1,4-cyclohexylene group or a 1,4-phenylene group is more preferable. At least one of C ¹ , C ² and C ³ is trans-1,4-cyclohexylene It is preferably a group.
[0027]
The general formula (II) preferably has a structure represented by the following general formula (IIa).
Embedded image

(Wherein, R ² and R ³ represent an alkyl or alkoxyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkenyloxy group having ³ to 16 carbon atoms, and B ³ represents 1 , 4-phenylene group or trans-1,4-cyclohexylene group, and r represents 0 or 1.)
The content of the compound of the general formula (IIa) is preferably in the range of 10 to 80% by mass.
[0028]
Further, the general formula (II) is also preferably a specific structure represented by the following general formula.
Embedded image

(Wherein, R ⁵ and R ⁶ each independently represent an alkyl or alkoxyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkenyloxy group having 3 to 16 carbon atoms. Are preferred.
Further, one or more compounds selected from the general formula (II) are contained, but one to six are preferable, and one to four are particularly preferable.
[0029]
In the general formulas (IIIa), (IIIb) and (IIIc), R ⁴ is preferably an unsubstituted linear alkyl group having 1 to 15 carbon atoms or an alkenyl group having 2 to 15 carbon atoms. A linear alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms is more preferable, and an unsubstituted linear alkyl group having 1 to 8 carbon atoms or an alkenyl group having 2 to 6 carbon atoms is particularly preferable. Preferably, the structures of the formulas (a) to (e) are more preferable for the alkenyl group. K ¹ , K ² and K ³ are preferably —COO—, —OCO—, —CH ₂ CH ₂ —, —C≡C—, — (CH ₂ ) ₄ — or a single bond, and —CH ₂ CH ₂ — , —C≡C— or a single bond is more preferable, —CH ₂ CH ₂ — or a single bond is particularly preferable, and when a plurality of K ¹ , K ² or K ³ are present, at least one is preferably a single bond. . p and q are preferably 0 or 1. C ¹ , C ² and C ³ are each independently a trans-1,4-cyclohexylene group, a 1,4-phenylene group, a 3-fluoro-1,4-phenylene group or a 3,5-difluoro-1, A 4-phenylene group is preferred, a trans-1,4-cyclohexylene group or a 1,4-phenylene group is more preferred, and a trans-1,4-cyclohexylene group is particularly preferred.
[0030]
X ² has the same definition as —H, —F, —Cl, CN, —CF ₃ , —CHF ₂ , —OCH ₂ F, —OCHF ₂ , —OCF ₃ , —CH ₂ CF _3, or R ¹ _{, -F, -CN, -CF 3,} -CHF 2, -OCH 2 F, -OCHF 2, preferably -OCF _3, F is particularly preferred.
The general formula (IIIa) has the following general formula as a specific structure:

[0031]
Embedded image

[0032]
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[0033]
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(Wherein, R ⁷ represents an alkyl group or an alkoxyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, X ³ and X ⁴ each independently represent H or F, and Y ⁴ Represents a structure of —CN, —F, —Cl, —CF ₃ , —OCF ₃ or —OCHF _2. ), And a structure represented by the following formula (IIIa-1) is also preferable.
[0034]
Embedded image

(Wherein, R ⁷ represents an alkyl group or alkoxyl group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, and L ⁵ and L ⁶ each independently represent —CH ₂ CH ₂ —, —CH ＝ CH—, —C≡C—, — (CH ₂ ) ₄ — or a single bond, ring I represents a 1,4-phenylene group or trans-1,4-cyclohexylene group, and X ⁶ represents Represents H or F, n represents 0 or 1, and Y ⁴ represents —CN, —F, —Cl, —CF ₃ , —OCF _3, or —OCHF _2. )
[0035]
The general formula (IIIb) has the following general formula as a specific structure:

[0036]
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(Wherein, R ⁷ represents an alkyl group or alkoxyl group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, and Y ⁴ represents —CN, —F, —Cl, —CF ₃ , —OCF. ₃ or —OCHF ₂ ). The general formula (IIIc) is a specific structure represented by the following general formula:
Embedded image

[0038]
Embedded image

[0039]
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(Wherein, R ⁷ represents an alkyl group or alkoxyl group having 1 to 8 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms, and Y ⁴ represents —CN, —F, —Cl, —CF ₃ , —OCF. It represents a ₃ or -OCHF _2.)
[0040]
It contains one or more compounds selected from the group consisting of the general formula (IIIa), the general formula (IIIb) and the general formula (IIIc), and one to ten kinds are preferable, and two to eight kinds are preferable. Particularly preferred.
[0041]
The nematic liquid crystal composition of the present invention contains one or more compounds selected from the general formula (I), and further includes a compound selected from the group consisting of the general formulas (IIIa), (IIIb) and (IIIc) It is preferable that one or more compounds selected from the formula (I) are contained, and one or more compounds selected from the general formula (I) are further contained, and one or more compounds selected from the general formula (II) are contained. It is also preferable to contain two or more types.
[0042]
It contains one or more compounds of the general formula (I), further contains one or more compounds of the general formula (II), and further contains the general formulas (IIIa), (IIIb) and (IIIb) It preferably contains at least one compound or two or more compounds selected from the group consisting of (IIIc), contains at least one compound of the general formula (II), and further contains the general formula (IIIa), It is preferable to contain at least two or more compounds selected from the group consisting of IIIb) and general formula (IIIc).
[0043]
It may contain one or more compounds selected from the general formula (IIIa), and may contain one or more compounds selected from the group consisting of the general formula (IIIb) and the general formula (IIIc). Preferably, the content of the group consisting of the general formulas (IIIa), (IIIb) and (IIIc) is in the range of 10 to 50% by mass.
[0044]
One or more compounds represented by the general formula (I) are contained, and the content thereof is in the range of 5 to 50% by mass, and one or more compounds of the general formula (IIa) are used. Containing at least one compound selected from the group consisting of the general formulas (IIIa), (IIIb) and (IIIc) in a content range of 10 to 60% by mass. It is particularly preferable that the content is in the range of 5 to 50% by mass.
[0045]
The nematic liquid crystal composition of the present invention has a wide liquid crystal phase temperature range (absolute value of the difference between the liquid crystal phase lower limit temperature and the liquid crystal phase upper limit temperature), but the liquid crystal phase temperature range is preferably 80 ° C or higher, more preferably 90 ° C or higher. Is more preferable, and 100 ° C. or higher is particularly preferable. The upper limit temperature of the liquid crystal phase is preferably 70 ° C. or higher, more preferably 80 ° C. or higher. Further, the lower limit temperature of the liquid crystal phase is preferably −20 ° C. or lower, more preferably −30 ° C. or lower.
[0046]
The nematic liquid crystal composition is useful for AM-LCDs and STN-LCDs, but is particularly useful for AM-LCDs, and can be used for transmissive or reflective liquid crystal display devices. The nematic liquid crystal composition of the present invention may contain a normal nematic liquid crystal, a smectic liquid crystal, a cholesteric liquid crystal, and the like, in addition to the above compounds.
[0047]
【Example】
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples. Further, “%” in the compositions of the following Examples and Comparative Examples means “% by mass”.
[0048]
The characteristics measured in the examples are as follows.
T _N-I: nematic phase - isotropic liquid phase transition temperature (℃) a liquid crystal phase upper limit temperature T _{→ N:} Solid phase or smectic phase - [Delta] T of the nematic phase transition temperature (℃) and liquid crystal phase lower limit temperature : Temperature range of nematic liquid crystal phase, | T _N−I −T _{→ N} |
Vth: threshold voltage (V) when a TN-LCD having a cell thickness of 6 μm is formed
Δε: dielectric anisotropy Δn: birefringence τr = τd: response speed (ms)
The following abbreviations are used in describing the compounds.
Terminal n (number) C _n H _{2n + 1} −
C trans-1,4-cyclohexylene group P 1,4 phenylene group E-COO-
e-OCO-
A -CH ₂ CH ₂ -
t-C≡C-
_{4 -CH 2 CH 2 CH 2 CH} 2 -
CN-C≡N
On -OC _n H _{2n + 1}
FF
F atom bonded at the ortho position of the f-terminal groups _{ndm- C n H 2n + 1 -C} = C- (CH 2) m-1 -
-O (dm) n -O (CH2) m-2-C = C-CnH2n + 1
[0049]
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[0050]
Example 1 Synthesis of 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indane (I-1)

[0051]
(1-1) Synthesis of ethyl 2- (3,4-difluorophenylmethyl) -6- (trans-4-propylcyclohexyl) hexanoate A solution of diisopropylamine (4.8 g) in tetrahydrofuran (THF) (50 ml). To the mixture was added a 1.5 M butyllithium-hexane solution (31 ml) at -78 ° C, and the mixture was stirred at -78 ° C for 30 minutes and at 0 ° C for 15 minutes. After cooling to -78 ° C, a solution of ethyl 6- (trans-4-propylcyclohexyl) hexanoate (10 g) in THF (30 ml) was added. After stirring for 1 hour, a solution of 3,4-difluorobenzyl bromide (10 g) in THF (30 ml) was added, and the temperature was raised to room temperature over 3 hours. The reaction solution was poured into 10% hydrochloric acid, extracted with ethyl acetate, the organic layer was washed with saturated saline, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 9: 1), and ethyl 2- (3,4-difluorophenylmethyl) -6- (trans-4-propylcyclohexyl) hexanoate (15.2 g) was used. ) Got.
[0052]
(1-2) Synthesis of 2- (3,4-difluorophenylmethyl) -6- (trans-4-propylcyclohexyl) hexanoic acid 2- (3,4-difluorophenylmethyl) -6- (trans-4- Ethanol (100 ml), water (40 ml) and sodium hydroxide (9 g) were added to ethyl propylcyclohexyl) hexanoate (15 g), and the mixture was heated under reflux for 4 hours. Ethanol (about 60 ml) was distilled off under reduced pressure, concentrated hydrochloric acid was added, and the mixture was extracted with toluene and concentrated to give crude 2- (3,4-difluorophenylmethyl) -6- (trans-4-propylcyclohexyl) hexanoic acid. (12.5 g) was obtained.
[0053]
(1-3) Synthesis of 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indanone 2- (3,4-difluorophenylmethyl) -6- (trans-4-propylcyclohexyl) ) Dichloromethane (25 ml) and thionyl chloride (20 ml) were added to the crude product of hexanoic acid (12 g), and the mixture was heated under reflux for 4 hours. Dichloromethane was distilled off under normal pressure, thionyl chloride was distilled off under reduced pressure, dichloromethane (50 ml) was added to the residue, and 2- (3,4-difluorophenylmethyl) -6- (trans-4-propylcyclohexyl) hexane was added. A dichloromethane solution of the acid chloride was prepared. This was added dropwise to a suspension of aluminum chloride (8 g) in dichloromethane (20 ml) at room temperature over 30 minutes. After further stirring for 2 hours, the reaction solution was poured into 10% hydrochloric acid under ice cooling. The organic layer was dried over anhydrous sodium sulfate and concentrated. The residue was purified by silica gel column chromatography (hexane: ethyl acetate = 20: 1) to give a crude product of 5,6-difluoro-2- (4- (trans-4-propylcyclohexyl) butyl) indanone (8.2 g). , Purity 70%). This was recrystallized from ethanol to obtain 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indanone (4.5 g, purity 99%). This compound was found to have a molecular weight of 348 by mass spectrometry.
[0054]
(1-4) Synthesis of 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indene 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] Sodium borohydride (2 g) was added to a solution of indanone (4.5 g) in ethanol (50 ml), and the mixture was stirred at room temperature for 1 hour. The reaction solution was poured into 10% hydrochloric acid, extracted with ethyl acetate, the organic layer was washed with saturated saline, dried over anhydrous sodium sulfate, and concentrated. Toluene (100 ml) and p-toluenesulfonic acid (1 g) were added to the residue, and the mixture was heated under reflux for 15 minutes. The reaction solution was returned to room temperature, washed with 10% hydrochloric acid and saturated saline, dried over anhydrous sodium sulfate, and concentrated. The residue was purified by silica gel column chromatography (hexane) to obtain 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indene (4 g). This compound had a molecular weight of 332 by mass spectrometry.
[0055]
(1-5) Synthesis of 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indane 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] Ethanol (70 ml), ethyl acetate (30 ml) and 5% palladium-carbon (450 mg) were added to indene (4 g), and the mixture was stirred under a hydrogen atmosphere for 1 hour. The reaction solution was filtered through celite, the filtrate was concentrated, and the residue was purified with a silica gel short column (hexane) to give 5,6-difluoro-2- (4- (trans-4-propylcyclohexyl) butyl) indane (4 g). ) Got. Further recrystallization from ethanol gave 5,6-difluoro-2- [4- (trans-4-propylcyclohexyl) butyl] indane (4 g, purity 99.8%). This compound had a molecular weight of 334 by mass spectrometry.
MS m / z 334 (M +)
1H NMR (CDCl ₃ ) δ 0.95 (t, J = 7 Hz, 3H), 1.2-1.5 (m, 22H), 2.0 (m, 1H), 2.9 (d, 4H) ), 6.8 (m, 2H)
[0056]
Example 2 Synthesis of 5,6-difluoro-2- {4- [trans-4- (trans-4-propylcyclohexyl) cyclohexyl] butyl} indane In Example 1, 6- (trans-4-propylcyclohexyl) )), Instead of ethyl hexanoate, using ethyl 6- (trans-4- (trans-4-propylcyclohexyl) cyclohexyl) hexanoate as a starting material, by the same procedure as in 5,6-difluoro-2- {4- [trans- 4- (trans-4-propylcyclohexyl) cyclohexyl] butyldiyne was obtained.
[0057]
(Examples 3 and 4) Preparation of liquid crystal composition Nematic liquid crystal compositions (No. 1) and (No. 2) shown below were prepared, and their physical properties were measured. The results are shown in Table 1.
[Table 1]

[0058]
As shown in Table 1, the nematic liquid crystal compositions of Examples 3 and 4 have a high liquid crystal phase minimum temperature (T _{→ N} ), a low liquid crystal phase maximum temperature (T _N−I ), and a wide liquid crystal temperature range. It turns out to have.
Using this nematic liquid crystal composition, a TFT liquid crystal display element having excellent display quality could be produced.
[0059]
(Comparative Examples 1 and 2)
The nematic liquid crystal compositions of Comparative Examples 1 and 2 were prepared, and the physical properties thereof are shown in Table 2.
[Table 2]

[0060]
It can be seen that the nematic liquid crystal composition of Comparative Example 1 has a configuration relatively close to the present invention, but is inferior in the maximum liquid crystal phase temperature. The liquid crystal composition of Comparative Example 2 in which the upper limit temperature of the liquid crystal phase was close to the liquid crystal composition of the example was equivalent to that of Example 1 at the upper limit temperature of the liquid crystal phase, but the lower limit temperature of the liquid crystal phase was significantly increased. You can see that there is.
[0061]
【The invention's effect】
The nematic liquid crystal composition of the present invention provides a nematic liquid crystal composition using a 5,6-difluoroindane-based compound, having a high liquid crystal phase minimum temperature, a low liquid crystal phase maximum temperature, and a wide liquid crystal phase temperature range. Became possible.

Claims (13)

General formula (I)

(Wherein R ¹ is a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, an alkyl group having 1 to 15 carbon atoms substituted by at least one halogen, an alkenyl group having 2 to 15 carbon atoms, or at least one halogen. Represents a substituted alkenyl group having 2 to 15 carbon atoms, wherein one or two or more CH ₂ groups present in each of these groups independently represent -O-, -S-, -CO-, -COO-, -OCO- or -OCO-O-,
A ¹ is,
(A) trans-1,4-one CH ₂ group or nonadjacent two or more CH ₂ groups existing in xylene group (in this group the cycloalkyl is replaced by -O- and or -S- May be)
(B) 1,4-phenylene group (one more CH ₂ groups not CH ₂ group or adjacent the present in this group may be replaced by-N-)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein the groups (a), (b) and (c) are substituted with CN or halogen. May be
n is 1 or 2. The indane compound represented by). A nematic liquid crystal composition comprising one or more compounds represented by formula (I). General formula (II)

(Wherein, R ² and R ³ each independently represent the same meaning as R ¹ ,
B ^{1, B 2} and ^{B 3} are each independently (a) trans-1,4-cyclohexylene group (not one CH ₂ group or adjacent present in this group two or more CH ₂ The group may be replaced by -O- and or -S-)
(B) 1,4-phenylene group (one more CH ₂ groups not CH ₂ group or adjacent the present in this group may be replaced by-N-)
(C) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl And 1,2,3,4-tetrahydronaphthalene-2,6-diyl, wherein the groups (a), (b) and (c) are substituted with CN or halogen. May be
o is 0, 1 or 2;
L ¹ , L ² and L ³ each independently represent a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O— or —C≡C—, When a plurality of L ² and B ³ exist, they may be the same or different. And / or a group consisting of general formulas (IIIa), (IIIb) and (IIIc)

(Wherein R ⁴ has the same meaning as R ^1, and C ¹ , C ² and C ³ each independently represent
(D) a trans-1,4-cyclohexylene group (in which one CH ₂ group or two or more non-adjacent CH ₂ groups are replaced by —O— and / or —S— May be)
(E) 1,4-phenylene group (one more CH ₂ groups not CH ₂ group or adjacent the present in this group may be replaced by-N-)
(F) 1,4-cyclohexenylene, 1,4-bicyclo (2.2.2) octylene, piperidine-1,4-diyl, naphthalene-2,6-diyl, 1,2,3,4-tetrahydro A group selected from the group consisting of naphthalene-2,6-diyl and decahydronaphthalene-2,6-diyl, wherein the groups (d), (e) and (f) are substituted with CN or halogen. However, when it represents 1,2,3,4-tetrahydronaphthalene-2,6-diyl, it is unsubstituted or substituted by at least two or more halogens,
K ¹ , K ² and K ³ each independently represent a single bond, —CH ₂ CH ₂ —, — (CH ₂ ) ₄ —, —OCH ₂ —, —CH ₂ O— or —C≡C—,
X ¹ , X ³ , X ⁴ , X ⁵ and X ⁶ are each independently H or F;
p and q are each independently 0, 1 or 2, but the sum of p and q is 2 or less;
X ² _{is, -H, -F, -Cl, CN} , -CF 3, -CHF 2, -OCH 2 F, -OCHF 2, -OCF 3, is the same definition as _-CH 2 CF _3, or ^{R 1.} 3. The nematic liquid crystal composition according to claim 2, comprising one or more compounds selected from the group consisting of: 4. The nematic liquid crystal composition according to claim 2, wherein the content of the compound of the formula (I) is in the range of 5 to 50% by mass. 4. The nematic liquid crystal composition according to claim 3, wherein the composition comprises at least two compounds selected from the group consisting of formulas (IIIa), (IIIb) and (IIIc). Claims: It contains at least one compound of the general formula (II), and further contains at least two or more compounds selected from the group consisting of the general formulas (IIIa), (IIIb) and (IIIc). 4. The nematic liquid crystal composition according to 3. As the compound of the general formula (II), a compound of the general formula (IIa)

(Wherein, R ² and R ³ represent an alkyl or alkoxyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkenyloxy group having ³ to 16 carbon atoms, and B ³ represents 1 , 4-phenylene group or trans-1,4-cyclohexylene group, and r represents 0 or 1.). The nematic liquid crystal composition according to claim 7, wherein the content of the compound of the formula (IIa) is in the range of 10 to 80% by mass. 4. The composition according to claim 3, which comprises one or more compounds selected from the general formula (IIIa), and one or more compounds selected from the group consisting of the general formulas (IIIb) and (IIIc). 7. The nematic liquid crystal composition according to 5 or 6. The nematic liquid crystal composition according to claim 9, wherein the content of the group consisting of the general formulas (IIIa), (IIIb), and (IIIc) is in the range of 10 to 50% by mass. One or more compounds represented by the general formula (I) are contained, and the content thereof is in the range of 5 to 50% by mass, and one or more compounds of the general formula (IIa) are used. Containing at least one compound selected from the group consisting of the general formulas (IIIa), (IIIb) and (IIIc) in a content range of 10 to 60% by mass. The nematic liquid crystal composition according to claim 10, wherein the content is in the range of 5 to 50% by mass. A liquid crystal display device using the nematic liquid crystal composition according to claim 2. An active matrix liquid crystal display device using the nematic liquid crystal composition according to claim 2.