| abstract |
Liquid crystal compositions having guest anthraquinone-based dyes dissolved therein, are disclosed. The anthraquinone-based dyes have the general formula: <IMAGE> wherein at least one of X and X' is a 5-membered ring connected to the lateral positions of the lateral benzene rings in the anthraquinone molecule, the five membered ring having the structure: <IMAGE> wherein R is an alkoxy alkyl radical, a straight chain or branched chain alkyl radical, a phenyl radical, a benzyl radical and/or substituted derivatives of the foregoing radicals. The anthraquinone-based dyes of the invention may be used alone or with other compatible dyes as guest dyes to form various colors for coloring the host liquid crystal compositions. One preferred class of guest anthraquinone-based dyes which are dissolved in the host liquid crystal material, are various derivatives of 1,4-diamino-2,3-anthraquinone-dicarboximide. |