Guest-host liquid crystal display device and guest-host liquid crystal

Abstract

A guest-host liquid crystal display device comprises a pair of substrates opposing each other with a space therebetween, a guest-host liquid crystal held in the space, the guest-host liquid crystal containing a dichroic dye mixture exhibiting a black color as a whole, and electrodes provided on the substrates for applying a voltage to the guest-host liquid crystal. The dichroic dye mixture comprises a bis-azo blue dye having a thienothiazole ring represented by the following chemical formula (1) and a tris-azo bluish purple dye having a benzothiazole ring represented by the following chemical formula (2): ##STR1## wherein R.sub.1 is a hydrogen or halogen atom, C.sub.n H.sub.2n+1, COC.sub.n H.sub.2n+1, OCOC.sub.n H.sub.2n+1, COOC.sub.n H.sub.2n+1, or CH.sub.2 COOC.sub.n H.sub.2n+1, wherein n is an integer from 1 to 8; each of R.sub.2 and R.sub.3 is a hydrogen atom or C.sub.n H.sub.2n+1 ; R.sub.3 may be ##STR2## or ##STR3## and a combination of R.sub.2 and R.sub.3 may form ##STR4## wherein n is an integer from 1 to 8, and m is an integer from 1 to 5; and R.sub.4 is a hydrogen or halogen atom, or C.sub.n H.sub.2n+1, wherein n is an integer from 1 to 8.