Liq. crystal compsn. for electro=optical display - contains 1-anilino-4-hydroxy- or 1,5-di:anilino-anthraquinone pleochroic dye

摘要

Liq. crystal material contains a dissolved pleochroic dye of formula (I): (R2 = H or OH; R3 = anilino (opt. substd. or modified). R1 = H when R2 = OH; or R1 is as R3 when R2 = H). Some pref. R3 gps. are cyclohexylamino (opt. substd.); heterocyclylamino; (Z2 = heterocyclic bridging gp.); 2-R5-anilino (R5= halo, or lower alkyl or alkoxy); 3-R6-anilino (R6=R5 or H) or 4-substd. anilino. In guest-host electro-optical devices. (I) have order parameters >=0.5 and better chemical, electrochemical or photochemical stability than azo dyes.