A novel liquid crystal material having a carbon chain containing a conjugated diene as a terminal substituent of the molecule and exhibiting superior characteristics is provided, which is a diene derivative expressed by the formula (I)
wherein R and R' each independently represent 1-5C alkyl; A and B each independently represent 1,4-cyclohexylene or 1,4-phenylene; n is 0 or 1; m is an integer of 0 to 2; X and X' each independently represent H atom or F atom when A is 1,4-phenylene or represent H atom when A is 1,4-cyclohexylene; Y is alkyl, halogen or CN, alkoxy, methyl group substituted by 1-3 halogen atoms or trihaloalkoxy when A is 1,4-phenylene, or represent alkyl, alkoxy, methyl group substituted by 1-3 halogen atoms or trihaloalkoxy when A is 1,4-cyclohexylene; and R and R' are not simultaneously alkyl chain of 4 or more carbon atoms.
The compound of the present invention has a generally usable viscosity and a high NI point and a high elastic constant ratio; hence the liquid crystal composition, particularly the liquid crystal composition for STN, containing the compound of the present invention exhibits improved characteristics as compared with the conventional ones.
本发明提供了一种新型液晶材料,其碳链含有共轭二烯作为分子的末端取代基,具有优异的特性,它是由式 (I) 表示的二烯衍
生物
其中 R 和 R'各自独立地代表 1-5C 烷基;A 和 B 各自独立地代表 1,4-
环己烯或 1,4-亚苯基;n 为 0 或 1;m 为 0 至 2 的整数;X 和 X'各自独立地代表 H 原子或 F 原子(当 A 为 1,4-亚苯基时)或代表 H 原子(当 A 为 1,4-
环己烯时);Y是烷基、卤素或CN、烷氧基、被1-3个卤素原子或三卤代烷氧基取代的甲基(当A为1,4-亚苯基时),或代表烷基、烷氧基、被1-3个卤素原子或三卤代烷氧基取代的甲基(当A为1,4-
环己烯时);且R和R'不同时是4个或更多碳原子的烷基链。
本发明的化合物具有一般可用的粘度、高 NI 点和高弹性常数比;因此,与传统的液晶组合物相比,含有本发明化合物的液晶组合物,特别是 STN 用液晶组合物,具有更好的特性。