Tolan derivatives, liquid crystal compositions containing them, and liquid crystal elements using them
申请人:SEIKO EPSON CORPORATION
公开号:EP0442266A1
公开(公告)日:1991-08-21
The present invention resides in novel compounds represented by the general formula:
wherein R indicates a straight chain alkyl group having 1 to 10 carbon atoms, A represents either
or single bond, and X represents hydrogen or fluorine, provided that the cyclohexane ring has the trans configuration, and liquid crystal compositions containing them. The compounds of the present invention have the following characteristics.
1. The anisotropy of dielectric constant Δε is positive and very large.
2. The anisotropy of double refraction Δn is large.
3. The nematic-isotopic liquid transition point (N-I point) is high.
Therefore, the use of a liquid crystal composition containing the compound of the present invention can provide a liquid crystal display device having the following characteristics.
1. The driving voltage is low.
2. The response speed is high.
3. The temperature range for practical use is wide.
本发明涉及通式所代表的新型化合物:
其中 R 表示具有 1 至 10 个碳原子的直链烷基,A 表示
或单键,X 代表氢或氟,条件是环己烷环具有反式构型,以及含有它们的液晶组合物。本发明的化合物具有以下特点。
1.介电常数 Δε 的各向异性为正且非常大。
2.双折射率 Δn 的各向异性很大。
3.向列-异构液体转变点(N-I 点)高。
因此,使用含有本发明化合物的液晶组合物可以提供具有以下特性的液晶显示设备。
1.驱动电压低。
2.响应速度快
3.实用温度范围广。