| abstract |
Liquid-crystalline medium having a birefringence Δn ≥ 0.12 on the basis of a mixture of polar compounds having a positive dielectric anisotropy, characterized in that it contains one or more compounds of the general formula I wherein X is fluorine, chlorine, CF 3 , OCF 3 or OCHF 2 and R is alkyl, oxaalkyl, fluoroalkyl or alkenyl each having up to 7 carbon atoms, and in that it additionally one or more compounds selected from the group consisting of contains general formulas V and VI, wherein R and X have the meanings given in relation to formula I and Y is Y or F. |