Patent ID: 7316830

Claim:
A liquid-crystalline medium comprising: at least one phenol ester of formula I in which R is H, an alkyl radical or alkenyl radical having up to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF 3 or at least monosubstituted by halogen, where, in addition, one or more CH 2 groups in said radicals are optionally replaced by —O—, —S—, —C≡C—, —OC—O— or —O—CO— in such a way that O atoms are not linked directly to one another, A 1 a) is a 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which in each case one or two non-adjacent CH 2 groups are each optionally replaced by —O— or —S—, b) is a 1,4-phenylene radical, in which one or two CH groups are each optionally replaced by N, c) is a piperidine-1,4-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl or 1,2,3,4-tetrahydronaphthalene-2,6-diyl radical, where the radicals a), b) and c) are in each case unsubstituted, monosubstituted or polysubstituted by halogen atoms, Z 1 is —CO—O—, —O—CO—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CH 2 CH 2 —, —C 2 F 4 —, —C 2 F 2 —, —CH═CH—, —C≡C— or a single bond, Y is F, Cl, or a monohalogenated or polyhalogenated alkyl, alkenyl, alkenyloxy or alkoxy radical having up to 5 carbon atoms, L is H or F, and m is 0, 1 or 2; and one or more compounds of formulae RII to RVI wherein R 0 is n-alkyl, oxoalkyl, fluoroalkyl, alkenyloxy or alkenyl, in each case having up to 9 carbon atoms, b is 0, 1 or 2, Y 1 is H or F, Alkyl* is a straight-chain alkyl radical having up to 9 carbon atoms, and Alkenyl or Alkenyl* is, in each case independently of one another, an alkenyl radical having up to 9 carbon atoms.