Patent ID: 6929833

Claim:
A liquid-crystalline medium comprising a mixture of polar compounds having positive dielectric anisotropy, wherein said mixture comprises one or more compounds of formula I, in which R is alkyl having 1 to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF3, and in which one or more CH 2 groups are each replaced by —O—in such a way that O atoms are not linked directly to one another, A 1 (a) is a trans- 1 ,4-cyclohexylene radical in which, in addition, one or more non-adjacent CH 2 groups may be replaced, in each case independently, by—O—or—S—, or a 1 ,4-cyclohexenylene radical, (b) is a 1 ,4-phenylene radical, in which, in addition, one or two CH groups may be replaced by N, (c) is a radical from the group consisting of 1,4-bicyclo[2.2.2]octylene, piperidine-1, 4-diyl, naphthalene-2,6-diyl, decahydro-naphthalene-2,6-diyl and 1,2,3,4-tetrahydro-naphthalene-2,6-diyl, wherein the radicals (a) and (b) may be monosubstituted or polysubstituted by CN, CH 3 or F, Z 1 is —CO—O—, —O—CO—, —CH 2 —O—, —OCH 2 —, —CH 2 CH2—, —CF 2 O—,—OCF 2 —, —CH═CH—, —C≡C—, —(CH 2 ) 4 —, —CH═CH—CH 2 CH 2 — or a single bond, Y is F, Cl, halogenated alkyl having 1 to 6 carbon atoms, halogenated alkenyl having up to 6 carbon atoms or halogenated alkoxy having 1 to 6 carbon atoms, L 1 is H or F,and m is 0 or 1.