Patent ID: 6028655
Filing Date: 2000-02-22
Classification: C09K

Abstract:
A liquid-crystal display containingtwo outer plates which, together with a frame, form a cell,a nematic liquid-crystal mixture of positive dielectric anisotropy which is present in the cell,electrode layers with alignment layers on insides of the outer plates,a pretilt angle between a longitudinal axis of molecules at a surface of the outer plates and the outer plates of from 8 degree to 30 degrees, anda twist angle of the liquid-crystal mixture in the cell from alignment layer to alignment layer with a value of between 22.5.degree. and 600.degree.,a chiral nematic liquid-crystal mixture comprisinga) 20-90% by weight of a liquid-crystalline component A consisting of one or more compounds having a dielectric anisotropy of greater than +1.5;b) 10-65% by weight of a liquid-crystalline component B consisting of one or more compounds having a dielectric anisotropy of -1.5 to +1.5;c) 0-20% by weight of a liquid-crystalline component D consisting of one or more compounds having a dielectric anisotropy of below -1.5, andd) 0-5% by weight of an optically active component C in such an amount that the ratio of the cell gap and the natural pitch of the chiral nematic liquid-crystal mixture is from about 0.2 to 1.3,wherein component A comprises at least one component of the formula IA ##STR82## in which R.sup.a is an alkyl group having 1 to 12 carbon atoms, in which, in addition, one or two non-adjacent CH.sub.2 groups may be replaced by --O--, --CH.dbd.CH--, --CO--, --OCO-- or --COO--,L is H or F, andr is 0 to 1,and component B comprises at least one compound of the formula IB ##STR83## in which R.sup.b is an alkenyl radical having 2 to 12 carbon atoms,R.sup.c is F, or an unsubstituted or at least monofluoro-substituted alkyl or alkoxy radical having 1-6 carbon atoms, ##STR84## are each, independently of one another, ##STR85## l is 0 or 1, and L.sup.1 and L.sup.2 are each, independently of one another, H or F.