Patent ID: 6929834

Claim:
A liquid-crystalline medium based on a mixture of polar compounds of negative dielectric anisotropy which comprises at least one compound of formula I in which R 11 and R 12 are each, independently of one another, an alkyl or alkenyl radical having up to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, where, in addition, one or more CH 2 groups in these radicals may each, independently of one another, be replaced by —O—, —S—, —C≡C—, —CO—, —CO—O—, -0-CO— or —O—CO—O— in such a way that 0 atoms are not linked directly to one another, L 1 and L 2 are each, independently of one another, H or F, Z is —CF 2 O-, —OCF 2 —, —C≡C—, —CF═CF—, —C 2 F 4 —, —COO—, —CH 2 O—, —OCH 2 —, —OCO— or a single bond, a is 0 or 1, and one or more compounds of formula III in which R 31 and R 32 are each, independently of one another, a straight-chain alkylalkoxy, alkyl or alkoxy radical having 1-12 carbon atoms, and