Liquid-crystalline halogen compounds, process for their preparation, dielectrics containing these, and electro-optical display element

Abstract

Liquid-crystalline halogen compounds of the formula ##STR1## wherein the ring A is 1,4-phenylene or trans-1,4-cyclohexylene; R.sub.1 is alkyl or alkoxy each of 1 to 12 carbon atoms or, when A is 1,4-phenylene, is also cyano; R.sub.2 is alkyl or alkoxy each of 1 to 12 carbon atoms or, when A is 1,4-cyclohexylene, is also chlorine or bromine; and X is fluorine, chlorine or hydrogen; with the proviso that at least one of the substituents R.sub.2 and X is a halogen atom are valuable components in liquid-crystalline dielectrics.

Dependencies are inferred from the claim text.