DIELECTRIC MATERIALS

摘要

A material suitable for a guest-host liquid crystal device comprises a solution of a liquid crystal material and a pleochroic dye characterized in that the dye comprises at least one anthraquinone compound free from water-solubilizing and ionic substituents and having the formula: Formula I wherein each of R and R1 independently represents an n-alkyl group having from 4 to 7 carbon atoms inclusive and wherein each of R2 and R3 is independently selected from hydrogen and alkyl groups having from 1 to 4 carbon atoms inclusive.