| 摘要 |
A liquid crystal medium based on a mixture of polar compounds with positive dielectric anisotropy also contains (i) one or more ester compounds and (ii) one or more 4-ring compounds. A liquid crystal medium based on a mixture of polar compounds with positive dielectric anisotropy also contains: (i) one or more ester compounds of formula (I) and (ii) one or more 4-ring compounds of formula (II). R1 and R2 = H or 1-15C alkyl (optionally substituted by halogen and optionally with one or more -CH2- groups replaced by -C-triple bond-C-, -CH=CH-, -O-, -CO-O- or -O-CO- such that O atoms are not directly bonded with each other); X1 and X2 = F, Cl, CN, SF6, SCN, NCS or up to 6C halo-alkyl, -alkenyl, -alkoxy or -alkenyloxy; Z1 and Z2 = -CF2O-, -OCF2- or a single bond but are not the same; rings A and B = 1,4-cyclohexylene, 1,4-phenylene or a group of formula (III)-(VIII); and L1-L6 = H or F. |
