Liquid crystal composition containing a pleochroic azo type compound.

摘要

A liquid crystal composition suitable for a guest-host liquid crystal device and the composition comprises a solution of a liquid crystal substance and a pleochroic dye which comprises at least one azo type compound having the formula (I), <CHEM> wherein R<1> represents a hydrogen atom; an alkyl group or an alkoxy group each of which may be substituted by an alkoxy or an aryl group; a cyclohexyl group which may be substituted by an alkyl group; or -COOR<3> (wherein R<3> represents an alkyl group which may be substituted by an alkoxy group, a cyclohexyl group which may be substituted by an alkyl group, or an aryl group which may be substituted by an alkoxy or an alkyl group); R<2> represents <CHEM> where R<4> and R<5> each represents an alkyl group which may be substituted by an alkoxy or an aryl group; or R<4> and R<5> may be connected to each other to form a ring; Z<1> and Z<2> each represents a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, or Z<1> and Z<2> may be connected to each other to form a carbocyclic ring or a nitrogenous heterocyclic ring; m is 1 or 2; and n is 0 or 1. o