Liquid crystals having pleochroic dyes
AssigneeSiemens Aktiengesellschaft
InventorsAlexander Moeller, Guenther Scherowsky
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Abstract
Anthraquinone dyes of the general formula: ##STR1## wherein R.sup.1, R.sup.3, R.sup.4 and R.sup.6 are selected from the group consisting of H, OH, OCH.sub.3, NO.sub.2, NH.sub.2 and NHCH.sub.3 ; R.sup.2 and R.sup.5 are selected from the group consisting of: ##STR2## wherein R.sup.7 is selected from the group consisting of alkyl-, aryl-, amino-, alkylamino-, dialkylamino-, arylamino-, alkyloxy-, and aryloxy radicals, along with their syntheses routes are disclosed. The dyes are particularly useful in liquid crystal displays which function with a "guest host" effect or in other electrooptical display devices having a medium therein switchable between different ordering states.
Claims3
A liquid crystal composition containing a pleochroic dye wherein the pleochroic dye is an anthraquinone dye having the general formula:
- ##STR17## wherein R.sup.1, R.sup.3, R.sup.4 and R.sup.6 are selected from the group consisting of H, OH, OCH.sub.3, NO.sub.2, NH.sub.2 and NHCH.sub.3 ;
- and R.sup.2 and R.sup.5 are each ##STR18## wherein R.sup.7 is selected from the group consisting of alkyl-, aryl-, amino-, alkylamino-, dialkylamino-, arylamino-, alkyloxy-, and aryloxy radicals.
Dependencies are inferred from the claim text.