Patent ID: 7056561

Claim:
A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, comprising at least one ester compound of formula I and at least one compound of formula IA wherein: R 1 and R 2 are each, independently H, a halogenated unsubstituted alkyl radical having from 1 to 15 carbon atoms, where one or more CH 2 groups in these radicals is optionally independently replaced by —C≡C—, —CH═CH—, —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, X 1 and X 2 are each, independently F, Cl, CN, SF 5 , SCN, NCS, a halogenated alkyl radical, a halogenated alkenyl radical, a halogenated alkoxy radical or a halogenated alkenyloxy radical, each having up to 6 carbon atoms, Z 1 and Z 2 are each, independently —CF 2 O—, —OCF 2 — or a single bond, where Z 1 ≠Z 2 , and are each, independently L 3 is F, and L 1 , L 2 and L 4 to L 6 are each, independently H or F.