Patent ID: 7078079

Claim:
A liquid-crystalline medium containing a mixture of polar compounds of positive or negative dielectric anisotropy, said medium comprising one or more compounds of formula I in which R 1 is an alkyl radical having from 1 to 12 carbon atoms which is unsubstituted, monosubstituted by CN or CF 3 or at least monosubstituted by halogen, where one or more CH 2 groups in these radicals may also, in each case independently of one another, be replaced by —O—, —S—, —CH═CH—, —C═C—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O atoms are not linked directly to one another, L 1-6 are each, independently of one another, H or F, Z 1 and Z 2 are each, independently of one another, —CF 2 CF 2 — or a single bond, where Z 1 ≠Z 2 , X is F, Cl, CN, OCN, NCS, SCN, an unsubstituted alkyl or alkoxy radical, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical having up to 6 carbon atoms, and u is 0 or 1, and v is 0 or 1, wherein