Patent ID: 6146720
Filing Date: 2000-11-14
Classification: C09K

Abstract:
Electro-optical liquid crystal displayhaving a realignment layer for realigning the liquid crystals whose field has a significant component parallel to the liquid crystal layerand which contains a liquid-crystalline medium of positive dielectric anisotropy, characterized in that the medium comprises at least one compound selected from the group of formulae Ia and Ib ##STR39## in which ##STR40## and R.sup.1 is H, an alkyl or alkenyl radical having 1 to 15 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 independently of one another, be 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,and at least one compound selected from the group of formulae IVa and IVb ##STR41## in which R.sup.5 is as defined for R.sup.1 and/or at least one compound of formula I which is different from the compounds of formulae Ia and Ib ##STR42## in which R.sup.1 is H, an alkyl or alkenyl radical having 1 to 10 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 independently of one another, be replaced by --O--, --S--, ##STR43## --CO, --CO--O, --O--CO-- or --O--CO--O-- in such a way that O-atoms are not linked directly to one another,A.sup.1 andA.sup.2 are each, independently of one another, a(a) trans-1,4-cyclohexylene radical or 1,4-cyclohexenylene radical, in which, in addition, one or more non-adjacent CH.sub.2 groups may be replaced by --O-- and/or --S--,(b) 1,4-phenylene radical, in which, in addition, one or two CH-groups may be replaced by N,(c) radical from the group consisting of 1,4-dicyclo (2,2,2)octylene, piperidine-1,4-diyl, napthaline-2,6- diyl, decahydronaphthaline-2,6-diyl and 1,2,3,4,-tetrahydronaphthaline-2,6-diylwhere the radicals (a) and (b) may be substituted by one two fluorine atoms,Z.sup.1 andZ.sup.2 are each, independently of one another, --CO--O--, --O--CO--, --CH.sub.2 O--, --OCH.sub.2 --, --CH.sub.2 CH.sub.2 --, --CH.dbd.CH--, --C.tbd.C--, or a single bond, or one of the radicals Z.sup.1 and Z.sup.2 is --(CH.sub.2).sub.4 -- or --CH.dbd.CH--CH.sub.2 CH.sub.2 -- andm is 0, 1 or 2.