COMPOUNDS AND PROCESS FOR CONTROLLING CONE TILT ANGLE IN MIXTURES OF SMECTIC LIQUID CRYSTAL COMPOUNDS

摘要

A process for controlling the cone tilt angle of a tilted smectic liquid crystal composition comprises the step of combining (a) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound comprising (i) an aliphatic fluorocarbon terminal portion comprising a terminal fluoroalkyl or fluoroether group and an alkylene group having at least two carbon atoms and containing at least one catenary ether oxygen atom, (ii) an aliphatic hydrocarbon terminal portion, and (iii) a central core connecting the terminal portions, wherein the alkylene group of the aliphatic fluorocarbon terminal portion is directly linked to the central core by a moiety selected from the group consisting of a covalent bond, -CH=CH-, and -CC-; and (b) at least one liquid crystal composition comprising at least one smectic or latent smectic liquid crystal compound; with the provisos that at least one of the compositions (a) and (b) comprises at least one chiral liquid crystal compound and that the combining of compositions (a) and (b) provides an optically active, tilted chiral smectic liquid crystal composition. The process enables control of cone tilt angle and thereby control of the brightness characteristics of liquid crystal display devices.