Patent ID: 9657231
Date: 2017-05-23
CPC Classifications: C09K

Claim:
1. A liquid-crystal medium, which comprises: at least one compound of the formula I and at least one compound of the formula II and at least one compound of the formula III: in which L 11 denotes R 11 or X 11 , L 12 denotes R 12 or X 12 , R 11 and R 12 , independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 15 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, X 11 and X 12 , independently of one another, denote H, F, Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated or fluorinated alkoxyalkyl having 2 to 7 C atoms, and independently of one another, denote in which L 21 denotes R 21 and, in the case where Z 21 and/or Z 22 denote trans-CH═CH— or trans-CF═CF—, alternatively denotes X 21 , L 22 denotes R 22 and, in the case where Z 21 and/or Z 22 denote trans-CH═CH— or trans-CF═CF—, alternatively denotes X 22 , R 21 and R 22 , independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, X 21 and X 22 , independently of one another, denote F or Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, fluorinated alkenyloxy or fluorinated alkoxyalkyl having 2 to 7 C atoms, one of Z 21 and Z 22 denotes trans-CH═CH—, trans-CF═CF— or —C≡C— and the other, independently thereof, denotes trans-CH═CH—, trans-CF═CF— or a single bond, and independently of one another, denote in which L 31 denotes R 31 or X 31 , L 32 denotes R 32 or X 32 , R 31 and R 32 , independently of one another, denote H, unfluorinated alkyl or unfluorinated alkoxy having 1 to 17 C atoms or unfluorinated alkenyl, unfluorinated alkenyloxy or unfluorinated alkoxyalkyl having 2 to 15 C atoms, X 31 and X 32 , independently of one another, denote H, F, Cl, —CN, —NCS, —SF 5 , fluorinated alkyl or fluorinated alkoxy having 1 to 7 C atoms or fluorinated alkenyl, unfluorinated or fluorinated alkenyloxy or unfluorinated or fluorinated alkoxyalkyl having 2 to 7 C atoms, Z 31 to Z 33 , independently of one another, denote trans-CH═CH—, trans-CF═CF—, —C≡C— or a single bond, and independently of one another, denote and optionally one or more further compounds, provided that the liquid-crystal medium has a birefringence, Δn, at 20° C. and 589 nm, of 0.250 or more.