Patent ID: 7371437

Claim:
Liquid-crystalline medium based on a mixture of polar compounds which comprises at least one compound of the formula I in which R 11 and R 12 each, independently of one another, denote H, an alkyl or alkenyl radical having 1 to 15 C atoms which is unsubstituted, monosubstituted by CN or CF 3 or monosubstituted to perhalo-substituted by halogen, where, in addition, one or more CH 2 groups in these radicals are optionally replaced by —O—, —S—, —C≡C—, —CF 2 O—, —OCF 2 —, —OC—O— or —O—CO— in such a way that O atoms are not linked directly to one another, denotes a) a 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which one or two non-adjacent CH 2 groups are optionally replaced by —O— or —S—, b) a 1,4-phenylene radical, in which one or two CH groups are optionally replaced by N, c) a radical from the group consisting of piperidine-1,4-diyl, 1,4-bicyclo[2.2.2]octylene, naphthalene-2,6-diyl, decahydronaphthalene-2,6-diyl, 1,2,3,4-tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl and fluorene-2,7-diyl, where the radicals a), b) and c) are optionally mono-or polysubstituted by halogen atoms; and further comprises one or more compounds of the formulae IIA and/or IIB in which R 2 denotes an alkyl or alkenyl radical having 1 to 15 C atoms which is unsubstituted, monosubstituted by CN or CF 3 or monosubstituted to perhalo-substituted by halogen, where, one or more CH 2 groups in these radicals are optionally, independently of one another, replaced by —O—, —S—, —C≡C—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O atoms are not linked directly to one another, p denotes 1 or 2, and v denotes 1 to 6.