Patent ID: 7455894

Claim:
A liquid-crystalline medium, comprising: one or more compounds of the formula Ia of Ib: in which R is a halogenated or unsubstituted alkyl or alkoxy radical having 1 to 15 C atoms, where one or more CH 2 groups in these radicals, independently of one another, are optionally replaced by —C≡C—, —CF 2 O—, —CH═CH—, —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another; and one or more compounds of at least one of formulae II′, IX, XI-XV, XXI and Q-3: wherein: R 0 is n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having 1 to 9 C atoms, R 1 and R 2 each, independently of one another, are n-alkyl, alkoxy, oxaalkyl, fluoroalkyl or alkenyl, each having 1 to 9 C atoms, X 0 is F, Cl, or halogenated alkyl, halogenated alkenyl, halogenated oxaalkyl, halogenated alkenyloxy or halogenated alkoxy having 1 to 6 C atoms, and Y 1 to Y 12 each, independently of one another are, H or F, provided that for formula II′, Y 4 , Y 5 and Y 6 are each H.