Patent ID: 6951669

Claim:
Liquid-crystalline medium comprising a mixture of polar compounds of positive dielectric anisotropy, wherein the medium comprises: one or more compounds of formula I in which R is H, an alkyl or alkenyl radical having 1 to 15 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 are optionally, in each case independently of one another, replaced by —O—, —S—, —CO—, —CO—O—, —O—CO— or —O—CO—O in such a way that O atoms are not linked directly to one another, is a trans-1,4-cyclohexylene ring, in which one or two CH 2 groups are optionally replaced by —O— and/or —S—, or a cyclohexenylene ring, Y is CF 3 , CHFCF 3 , CF 2 CF 3 or halogenated alkoxy having 1 to 6 carbon atoms, Z is —CH 2 O—, —OCH 2 —, —CH 2 CH 2 —, —CH═CH—, —CF 2 O—, —OCF 2 —, —C 2 F 4 — or a single bond, and n is 1 or 2; and one or more ester compounds of the formulae E2, E3 or E4 θ wherein R 0 is n-alkyl, oxoalkyl, fluoroalkyl or alkenyl, in each case having 1 to 7 carbon atoms, and Alkyl and Alkyl* are each, independently, straight or branched chain alkyl of 1 to 7 carbon atoms.