Patent ID: 6793984
Filing Date: 2004-09-21
Classification: C07C,C09K

Abstract:
A liquid-crystalline medium comprising at least two mesogenic compounds, including at least one (dihydro)phenanthrene derivative of the formula I in whichR is an alkyl or alkenyl radical having up to 15 carbon atoms which is unsubstituted, monosubstituted by CN or CF3 or at least monosubstituted by halogen, where, in addition, one or more CH2 groups in these radicals may be replaced by â€”Oâ€”, â€”Sâ€”, â€”Câ‰¡Câ€”, â€”OCâ€”Oâ€” or â€”Oâ€”COâ€” in such a way that O atoms are not linked directly to one another, A1 a) is a 1,4-cyclohexenylene or 1,4-cyclohexylene radical, in which one or two non-adjacent CH2 groups may be replaced by â€”Oâ€” or â€”Sâ€”, or b) a 1,4-phenylene radical, in which one or two CH groups may be replaced by N, where the radicals a) and b) may be monosubstituted or polysubstituted by fluorine,Z1 is â€”COâ€”Oâ€”, â€”Oâ€”COâ€”, â€”CF2Oâ€”, â€”OCF2â€”, â€”CH2Oâ€”, â€”OCH2â€”, â€”CH2CH2â€”, â€”C2F4â€”, â€”CH&boxH;CHâ€”, â€”Câ‰¡Câ€” or a single bond, Y is H, F, Cl, CN, SF5, NCS, SCN or an alkyl, alkenyl, alkenyloxy or alkoxy radical having from 1 to 5 carbon atoms which is monohalogenated or polyhalogenated, G is â€”CH2CH2â€”, â€”CH&boxH;CFâ€” or â€”CH&boxH;CHâ€”, L1, L2, L3, L4 and L5 are each, independently of one another, H or F, and m is 0, 1 or 2, and one or more compounds selected from the group consisting of the general formulae II, III, IV, V, VI, VII, VIII and IX: in which the individual radicals have the following meanings:R0 is n-alkyl, oxaalkyl, fluoroalkyl, alkenyloxy or alkenyl, each having up to 9 carbon atoms, X0 is halogenated alkoxy having from 1 to 6 carbon atoms, Z0 is â€”C2H4â€”, â€”C2F4â€”, â€”CH2Oâ€”, â€”OCH2â€”, â€”CF2Oâ€”, â€”OCF2â€” or â€”COOâ€”, Y1, Y2, Y3 and Y4 are each, independently of one another, H or F, and r is 0 or 1.