Mixture of non-cyano high birefringence laterally fluorinated terphenyl amp; cyclohexyl-biphenyl liquid crystalline compounds having halogenated terminal groups

摘要

The invention relates to a liquid-crystalline medium based on a mixture of polar compounds of positive dielectric anisotropy, characterized in that it contains one or more fluorinated terphenyls having the formula I and one or more compounds of the formula II wherein R and R' are independently an alkyl or alkenyl radical having up to 12 C atoms, these radicals being unsubstituted or substituted by halogen, it also being possible for one or more CH 2 groups in these radicals to be replaced, in each case independently of one another, by -O-, -CO-O- or -O-CO- in such a manner that oxygen atoms are not linked directly to one another; X and X' are independently F, Cl, CF 3 , OCF 3 or OCHF 2 ; and L 1 and L 2 are independently H or F.