Patent ID: 6056894
Filing Date: 2000-05-02
Classification: C09K

Abstract:
A liquid-crystal display comprising:two 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 the insides of the outer plates,a pretilt angle between the longitudinal axis of the molecules at the surface of the outer plates and the outer plates of 0-30 degrees, anda twist angle of said liquid-crystal mixture in the cell from alignment layer to alignment layer with a value of 22.5.degree.-600.degree.;wherein said nematic liquid-crystal mixture comprises:a) 20-90% by weight of a liquid-crystalline component A 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 of one or more compounds having a dielectric anisotropy of -1.5-+1.5;c) 0-20% by weight of a liquid-crystalline component C of one or more compounds having a dielectric anisotropy of below -1.5, andd) optionally an optically active component D in an amount whereby the ratio between the separation of the outer plates and the natural pitch of the resultant chiral nematic liquid-crystal mixture is 0.2-1.3;wherein component A comprises at least one compound of formula IA ##STR85## 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 or 1; andwherein component B comprises at least one compound of formula IB ##STR86## in which R.sup.b and R.sup.c are each, independently of one another, an alkenyl group having, 2 to 7 carbon atoms.