Patent ID: 7189440

Claim:
A liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, which comprises one or more pyran compounds of the formula I: and one or more compounds selected from the group consisting of the compounds of formulae C-1 to C-5: in which R and R 1 are each, independently of one another, H, a halogenated or unsubstituted alkyl or alkoxy radical having from 1 to 15 carbon atoms, where, optionally, one or more CH 2 groups in these radicals, independently of one another, are replaced by —C≡C—, —CH═CH—, —O—, —CO—O— or —O—CO— in such a way that O atoms are not linked directly to one another, and are each, independently of one another, X and X 1 are each, independently of one another, F, Cl, CN, SF 5 , NCS, a halogenated alkyl radical having 1 to 8 carbon atoms, where 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 and Z 2 are each, independently of one another, —COO—, —OCO—, —CH 2 O—, —OCH 2 —, —CH═CF—, —CF═CH—, —CF 2 CF 2 —, —CF═CF—, —C≡C—, —CH 2 CH 2 —, —(CH 2 ) 4 —, —CH═CH— or a single bond, L 1-6 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≦3.