Patent ID: 7662443

Claim:
A liquid-crystalline medium consisting of: one or more compounds of the formula I in which are 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 selected 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 monosubstituted or polysubstituted by halogen atoms, x, y and z are each, independently of one another, 0, 1 or 2, provided that the compound has at least one ring A 1 to A 4 which is a 2,3-difluoro-1,4-phenylene ring, Z 1 , Z 2 and Z 3 are each, independently of one another, —CO—O—, —O—CO—, —CF 2 O—, —OCF 2 —, —CH 2 O—, —OCH 2 —, —CH 2 CH 2 —, —(CH 2 ) 4 —, —C 2 F 4 —, —CH 2 CF 2 —, —CF 2 CH 2 —, —CF═CF—, —CH═CH—, —C≡C— or a single bond, X is F, Cl, CN, SF 5 , NCS, a halogenated or unsubstituted alkyl radical having 1 to 8 carbon atoms, in which one or more CH 2 groups are optionally replaced by —O— or —CH═CH— in such a way that O atoms are not linked directly to one another, a is 0, 1 or 2, b is 0, 1 or 2, and c is 0, 1 or 2, where a+b+c is from 1 to 3; and additionally consisting of at least one compound of the formula RVIII: in which alkyl and alkyl* are each, independently of one another, a straight-chain or branched alkyl radical having from 2 to 8 carbon atoms; optionally, further containing one or more compounds of the formulae RI to RVII, RIX to RXII or RXIV: in which R 0 is n-alkyl, oxaalkyl, fluoroalkyl, alkenyloxy or alkenyl, each having from 2 to 8 carbon atoms, d is 0, 1 or 2, Y 1 is H or F, alkyl and alkyl* are each, independently of one another, a straight-chain or branched alkyl radical having from 2 to 8 carbon atoms, and alkenyl and alkenyl* are each, independently of one another, a straight-chain or branched alkenyl radical having from 2 to 8 carbon atoms; optionally, further containing one or more compounds of the formulae II to XX: wherein R 0 is n-alkyl, oxaalkyl, fluoroalkyl, alkenyloxy or alkenyl, each having from 2 to 12 carbon atoms, X 0 is F, Cl, halogenated alkyl, halogenated alkenyl, halogenated alkenyloxy or halogenated alkoxy each having up to 8 carbon atoms, Z 0 is —CH═CH—, —C 2 H 4 —, —CH 2 O—, —OCH 2 —, —(CH 2 ) 4 —, —C 2 F 4 —, —CF═CF—, —CF 2 O—, —OCF 2 — or —COO—, Y 1 , Y 2 , Y 3 and Y 4 are each, independently of one another, H or F, and r is 0 or 1; and optionally, further containing one or more compounds of the formula DI or DII: wherein R 0 is as defined above.