Patent ID: 6929832

Claim:
A nematic liquid-crystal medium, comprising a) one or more dielectrically positive compound(s) of the formula I in which R 1 is alkyl or alkoxy having 1 to 7 carbon atoms, alkoxyalkyl, alkenyl or alkenyloxy having 2 to 7 carbon atoms, Z 11 , Z 12 and Z 13 are each, independently of one another, —CH 2 —CH 2 —, —CH═CH—, —C≡C—, —COO— or a single bond, are each, independently of one another, X is F, or OCF 3 , where, in the case where X=F, Y is F, and in the case where X=OCF 3 , Y is H or F, and n and m are each, independently of one another, 0 or 1; b) one or more dielectrically negative compound(s) of the formula II in which R 21 and R 22 are each, independently of one another, as defined for R 1 under the formula I, Z 21 and Z 22 are each, independently of one another, as defined for Z 11 above under the formula I, are each, independently of one another, L 1 and L 2 are both C—F or one of the two is N and the other is C—F, and 1 is 0 or 1; and optionally c) one or more dielectrically neutral compound(s) of the formula III in which R 31 and R 32 are each, independently of one another, as defined for R 1 above under the formula I, and Z 31 , Z 32 and Z 33 are each, independently of one another, —CH 2 CH 2 —, —CH 2 O—, —OCH 2 —, —CF 2 O—, —OCF 2 —, —COO— or a single bond, and, additionally, one of Z 31 , Z 32 and Z 33 may also be —CF 2 CF 2 —, are each, independently of one another, o and p, independently of one another, are 0 or 1, wherein the medium has a positive dielectric anisotropy of 3.2 or more, a birefringence, Δn, of less than or equal to 0.11, and the ratio of the dielectric anisotropies of the liquid-crystal medium parallel and perpendicular to the director is less than or equal to 1.93.