DIFLUORBENZOLDERIVATE

摘要

Difluorobenzol derivatives of formula (I) wherein Q<1> and Q<2>, independently, denote R or R-A<1>-A<2>-Z, where R denotes an unsubstituted C1-C15 alkyl or a C1-C15 alkyl or C3-C15 alkenyl monosubstituted by cyanogen or at least monosubstituted by fluorine or chlorine, whereby a CH2 group in these residues can also be substituted by -O-, -CO-, -O-CO-, -CO-O- or -O-CO-O-; A<1> and A<2>, independently, denote trans-1,4-cyclohexylene, wherein one or two non-neighbouring CH2 groups can also be replaced by -O-, or unsubstituted 1,4-phenylene or 1,4- phenylene substituted by one or two fluorine atoms, wherein one or two CH2 groups can also be replaced by N; or one of the two groups A<1> and A<2> can also denote a single bond; Z denotes -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2- or a single bond; and m is equal to 0 or 2; provided that when (a) Q<1> = alkyl or alkoxy and Q<2> = alkyl, alkoxy, -Z- alpha -alkyl- or -Z- alpha -alkoxy, or (b) Q<1> = alkyl- alpha or alkoxy- alpha and Q<2> = alkyl or alkoxy, m is equal to 0. These derivatives are suitable as components of liquid crystal phases.