| 摘要 |
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 CF<SUB>3 </SUB>or at least monosubstituted by halogen, where one or more CH<SUB>2 </SUB>groups 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 CH<SUB>2 </SUB>groups 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<SUB>2</SUB>-, -CH<SUB>2</SUB>CH<SUB>2</SUB>-, -CH-CH-, -CF<SUB>2</SUB>O-, -OCF<SUB>2</SUB>-, -C<SUB>2</SUB>F<SUB>4</SUB>- or a single bond; and n is 1 or 2. And the mixture contains one or more dioxane compounds of the following formula wherein R<SUP>0 </SUP>is n-alkyl, oxoalkyl, fluoroalkyl or alkenyl, in each case having 1 to 7 carbon atoms; and X<SUP>0 </SUP>is F, Cl, halogenated alkyl, alkenyl or alkoxy having 1 to 6 carbon atoms.
|
