| abstract |
A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, which contains:n one or more compounds of the general formula I n n in which R, n n Y, Z and n are as defined in claim 1, one or more compounds of the following formulae IIa, IIb, IIc and IId n n nandn one or more compounds of the formula n n in which R o , X o , Y 2 and r are as defined in claim 1. |