Patent ID: 6039893
Filing Date: 2000-03-21
Classification: C09K

Abstract:
A guest-host liquid crystal display device comprising:a pair of substrates opposing each other with a space therebetween;a guest-host liquid crystal held in said space, said guest-host liquid crystal containing a mixture of dichroic dyes exhibiting a black color as a whole, said mixture of dichroic dyes is present in an amount less than or equal to 5 percent by weight; andelectrodes provided on said substrates for applying a voltage to said guest host liquid crystal;said mixture of dichroic dyes comprising 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): ##STR49## 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 ##STR50## or ##STR51## and a combination of R.sub.2 and R.sub.3 may form ##STR52## 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.