Patent ID: 7198828

Claim:
A liquid-crystalline medium comprising one or more compounds of formula A and at least one compound of formula B in which R a is H or an alkyl radical having 1 to 12 carbon atoms which is unsubstituted or monosubstituted by CN or CF 3 , or at least monosubstituted by halogen, in which one or more CH 2 groups are optionally, independently of one another, replaced by —O—, —S—, —CH═CH—, —C≡C—, —CO—, —CO—O—, —O—CO— or —O—CO—O— in such a way that O atoms are not linked directly to one another, R b is H or an alkyl radical having 1 to 12 carbon atoms which is unsubstituted or monosubstituted by CN or CF 3 , or at least monosubstituted by halogen, in which one or more CH 2 groups are optionally, independently of one another, replaced by —O—, —S—, —C≡C—, —CO—, —CO—O—, —O—CO— or —O—CO—O— 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, —(CH 2 ) 4 —, —CF 2 O—, —COO—, —OCF 2 —, —OCH 2 —, —CH 2 O—, —CH 2 —, —(CH 2 ) 3 — or a single bond, wherein at least one of Z 1 and Z 2 is —OCF 2 — or —CF 2 O—, L 1 to L 9 are each, independently of one another, H or F, and Y is F, Cl, SF 5 , NCS, OCN, CN, SCN, or a monohalogenated or polyhalogenated alkyl, alkoxy, alkenyl or alkenyloxy radical, each having up to 5 carbon atoms; provided that the medium comprises: at least one compound of formula IV in which m is 1, R 4 is an alkenyl group having 2 to 7 carbon atoms, R 5 is as defined for R a or is F, Cl, CF 3 or OCF 3 , L 1 is F and L 2 is H or F, or that at least one compound of formula B is of the following formula B-2; in which R b is a C 2-12 alkenyl radical.