| 摘要 |
Liquid crystalline medium having a helical twisted structure comprising a nematic component and an optically active component is characterized in that the optically active component contains one or more chiral compounds whose twist properties and concentration are such that the helical pitch of the medium is no greater than 1 mu m and the nematic component comprises at least aromatic compounds. A liquid crystalline medium having a helical twisted structure comprising a nematic component and an optically active component is characterized in that the optically active component contains one or more chiral compounds whose twist properties and concentration are such that the helical pitch of the medium is no greater than 1 mu m and the nematic component comprises a compound of formula (I) and one or more compounds of formula (II) and/or (III): R, R<1>, R<2> = H, 1-15C alkyl or alkenyl, optionally mono-substituted by CN or CF3 or at least monosubstituted by halogen whereby non-neighboring CH2 groups are replaced by -O-, -S-, 1,4-cyclobutyl, -CO-, -CO-O-, -O-CO-O-; A<1>-A<3> = 1,4-cyclohexlyene or a group of formula (V): L<1>-L<6> = H or F; Z<1> = -COO- when A<1> and A<2> are trans-1,4-cyclohexylene, or -CH2CH2 or a single bond; Z<2> = -CH2CH2 or a single bond; Z<3> = -COO-, -CH2CH2 or single bond; X = F, Cl, CN or 1-6C halogenated alkyl, alkenyl or alkoxy; a, b, c = 0 or 1 An Independent claim is included for an electrooptical liquid crystal display containing a liquid crystalline medium (I). |
