Patent ID: 7449222

Claim:
A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, comprising one or more pyran compounds of formula I and one or more compounds of formulae C1, C2, C3, C4, C5, C6, C8 and/or C9 wherein R and R 1 are each, independently of one another, H, a halogenated or unsubstituted alkyl or alkoxy radical having 1 to 15 carbon atoms, wherein one or more CH 2 groups are optionally each, independently of one another, replaced by —C≡C—, —CH═CH—, —O—, —CO—O—, —O—CO—, in such a way that O atoms are not linked directly to one another, are each, independently of one another, X and X 1 are each, independently of one another, F, CI, SF 5 , NCS, a halogenated alkyl radical having up to 8 carbon atoms, wherein one or more CH 2 groups are optionally replaced by —O— or —CH═CH— in such a way that O atoms are not linked directly to one another, Z 1 and Z 2 are each, independently of one another, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CF 2 CF 2 —, —CF═CF—, —C≡C—, —CF 2 O—, —OCF 2 , —CH═CF—, —CF═CH—, —CH 2 CH 2 —, —(CH 2 ) 4 —, —CH═CH— or a single bond, L 1 and L 2 are each, independently of one another, H or F, and m and n are each, independently of one another, 0, 1, 2 or 3, where m+n is ≦3 with the proviso that said medium does not contain compounds having the backbone unit structure where D is H or F.