Liquid crystals having pleochroic dyes

US4363743A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Alexander Moeller · Gelnhausen, DE
• Guenther Scherowsky · Berlin, DE

Key dates

• Filing date: Feb 4, 1981
• Grant date: Dec 14, 1982
• Expiry date: Feb 4, 2001

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C09B43/22
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

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.