Patent ID: 6183821
Filing Date: 2001-02-06
Classification: C07C,C09K

Abstract:
A supertwist liquid-crystal display comprising:two outer plates which, together with a frame, form a 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 from about 1 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 100.degree. and 600.degree., anda nematic liquid-crystal mixture of positive dielectric anisotropy which is present in the cell, comprising:a) 5-90% by weight of a liquid-crystalline component A consisting of one or more compounds having a dielectric anisotropy of greater than +1.5;b) 10-80% by weight of a liquid-crystalline component B consisting of one or more compounds having a dielectric anisotropy of between -1.5 and +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) an optically active component C in such an amount that the ratio between the layer thickness and the natural pitch of the chiral nematic liquid-crystal mixture is from about 0.2 to 1.3,wherein the liquid-crystal mixture comprises one or more compounds of the formula IA ##STR96##in whichR.sup.a is alkyl, alkoxy, alkenyl or alkenyloxy having 1 to 12 carbon atoms,R.sup.b is alkyl or alkoxy having 1 to 5 carbon atoms,Z is --COO--, --CH.sub.2 CH.sub.2 -- or a single bond, and ##STR97##are each, independently of one another, ##STR98##and one of the rings ##STR99##may alternatively be ##STR100##and component B comprises one or more compounds of the formula IB ##STR101##in whichR.sup.3 is an alkenyl group having 2 to 7 carbon atoms,R.sup.4 is as defined for R.sup.a in the formula IA, andc is 0 or 1.