Dichroic liquid crystal compositions made with asymmetric tris-azo dyes

Abstract

Novel asymmetric tris-azo dye compositions and a liquid crystal composition containing the asymmetric tris-azo dye compositions are disclosed. The asymmetric dye compositions having asymmetric terminal groups have the general formula: ##STR1## wherein R.sub.1 is one of the three following groups: ##STR2## 5-nitrothiazolyl group, 4-cyanophenyl group, and 4-nitrophenyl; wherein R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are selected from the group consisting of hydrogen, alkyl, halogen and alkoxy, and R.sub.6 is selected from the group consisting of N,N-diethylamino-3-methylphenyl; N,N-diethylamino-3-methylphenyl; N,N-diethylamino-3,5-dimethylphenyl; 2-pentylperimidyl; N-ethylamino-1-naphthyl; N,N-dimethylamino-1-naphthyl; and N,N-diethylamino-1-naphthyl. When the asymmetric tris-azo dichroic dyes are used as a guest in a host liquid crystal material, they form a novel liquid crystal composition for use in liquid crystal displays.

Dependencies are inferred from the claim text.