Liquid-crystalline medium

Abstract

A liquid-crystalline medium containing a mixture of polar compounds of positive dielectric anisotropy. The mixture contains 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 CFor at least monosubstituted by halogen, where one or more CHgroups 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 CHgroups are optionally replaced by —O— and/or —S—, or a cyclohexenylene ring; Y is halogenated alkyl, halogenated alkenyl, halogenated alkoxy or halogenated alkenyloxy having 1 to 6 carbon atoms; Z is —OCH—, —CHCH—, —CH═CH—, —CFO—, —OCF—, —CF— or a single bond; and n is 1 or 2. And the mixture contains one or more dioxane compounds of the following formula wherein Ris n-alkyl, oxoalkyl, fluoroalkyl or alkenyl, in each case having 1 to 7 carbon atoms; and Xis F, Cl, halogenated alkyl, alkenyl or alkoxy having 1 to 6 carbon atoms.