Patent ID: 6692796
Filing Date: 2004-02-17
Classification: C09K

Abstract:
A liquid crystal medium, comprising:15-40% by weight of a component A which comprises one or ore compounds of formula I: wherein R11 and R12 are, independently of one another, n-alkyl, n-alkoxy with 1 to 7 C atoms, alkenyl, alkenyloxy or alkoxyalkyl with 2 to 7 C atoms, at least one of the A11, A12 and 13 rings is â€ƒand the others of the A1, A12 and A13 rings are each, independently of each other, and further optionally the R11ring is one of Z11 and Z12 is â€”Câ‰¡Câ€” and the other one, if present, is â€”Câ‰¡Câ€”, â€”CH2Oâ€”, â€”CF2Oâ€”, â€”OCF2â€”, trans- â€”CH&boxH;CHâ€”, trans â€”CF&boxH;CFâ€”, â€”COOâ€”, â€”CH2â€”CH2â€”, â€”CF2â€”CF2â€” or a single bond, and n is 0 or 1; and 25-60% by weight of a component B which comprises one or more dielectrically positive compounds of formula II: wherein R2 has the meaning given for R11 in this claim, the A21, A22 and A23 rings each independently have the meaning given for the Aâ€‚ ring above Z21 and Z22 are independently of each other â€”CH2CH2â€”, â€”COOâ€”, trans- â€”CH&boxH;CHâ€”, trans-CF&boxH;CFâ€”, â€”CH2Oâ€”, â€”CF2Oâ€” or a single bond, X2 is, F, Cl, CF3, OCF2H or OCF3 and m is 0, 1 or 2; and 6-40% by weight of a component C, which comprises one or ore compounds of formula III: wherein R31 and R32 each, independently of each other, have the meaning given for R11, Z31 and Z32 are, independently of each other, â€”CH2C2â€”, â€”COOâ€”, â€”Câ‰¡Câ€”, trans- â€”CH&boxH;CHâ€”, trans- â€”CF&boxH;CFâ€”, â€”CH2O, â€”CF2Oâ€” or a single bond, the A31, A32 and A33 rings each have the meaning given for the A11 ring, and k is 0 or 1; and 2-30% of a component D comprising one or more compounds of formula IV: wherein R41 and R42 each, independently of each other, have the meaning given for R11, Z4 are, independently of each other, â€”CH2CH2, â€”COOâ€”, â€”Câ‰¡Câ€” or a single bond, preferably a single bond and o is 0 or 1.