Patent ID: 6287648
Filing Date: 2001-09-11
Classification: C09K

Abstract:
A liquid-crystalline medium having a mixture of polar compounds of positive dielectric anisotropy, comprising one or more compounds of the formula I: ##STR66##whereinR.sup.1 and R.sup.2 are each, independently of one another, an alkyl or alkenyl radical having 1 to 12 carbon atoms which is unsubstituted, monosubstituted by CN or CF.sub.3 or at least monosubstituted by halogen, where one or more CH.sub.2 groups in these radicals may also, in each case independly of one another, be replaced by --O--, --S--, ##STR67##--CO--, --CO--O, --O--CO-- or --O--CO--O-- in such a way that O atoms are not linked directly to one another, and u is 1 or 2; andone or more compounds of the formulae II, III, V, VI, VII or VIII; ##STR68##wherein the individual radicals have the following meanings:R.sup.0 : n-alkyl, oxaalkyl, fluoroalkyl or alkenyl, in each case having up to 9 carbon atoms;X.sup.0 : F, Cl, halogentated alkyl, alkenyl or alkoxy having 1 to 6 carbon atoms;Z.sup.0 : --C.sub.2 H.sub.4 --, --CH.sub.2 --O--, --OCH.sub.2 --, --CF.sub.2 O-- or --C.sub.2 F.sub.4 --,Y.sup.1 and Y.sup.2 : each, independently of one another, H or F; andr: 0 or 1.