Liquid crystal medium with helical twisted structure, for electrooptical purposes e.g. cholesteric, surface- or polymer-stabilized cholesteric flexoelectric or active matrix display, contains chiral compound and 2 types of nematic compound

Liquid crystal (LC) medium with helical twisted structure contains an optically active component comprising chiral compound(s) of twisting power and concentration giving medium a helix pitch = 1 mu m and a nematic component comprising 2 types of 2- or 3-ring 1-fluoro-, -chloro-, -haloalk(en)yl or -haloalkoxy-4-substituted-benzene compounds, comprising compound(s) (I) with cyclohexyl and/or phenyl rings and (II) with 1,3-dioxan-2-yl or 5-cyclohexyl-1,3-dioxan-2-yl rings. Liquid crystal (LC) medium with helical twisted structure contains an optically active component comprising chiral compound(s) of twisting power and concentration giving medium a helix pitch = 1 mu m and a nematic component comprising 2 types of 2- or 3-ring 1-fluoro-, -chloro-, -haloalk(en)yl or -haloalkoxy-4-substituted-benzene compounds, comprising compound(s) of formula (I) with cyclohexyl and/or phenyl rings and of formula (II) with 1,3-dioxan-2-yl or 5-cyclohexyl-1,3-dioxan-2-yl rings; A 1>, A 2> independently : trans-1,4-cyclohexylene, 1,4-phenylene or 2-fluoro- or 2,6-difluoro-1,4-phenylene; Z 1>, Z 2> : a single bond or bridging group; X 0> : F, Cl or 1-6 C haloalk(en)yl or haloalkoxy; a, b : 0 or 1 The full definitions are given in the DEFINITIONS (Full Definitions) Field. [Image]. Die vorliegende Erfindung betrifft ein flüssigkristallines Medium mit hoher Verdrillung, seine Verwendung für elektrooptische Zwecke und dieses Medium enthaltende Anzeigen.