Liquid crystals mixture

Abstract

Abstract A liquid crystal mixture for electro-optical displays without polarising cover discs consists essentially of a nematic liquid crystal mass with positive or negative dielectric anisotropy as host phase, an optically active additive to effect cholesteric orientation of the host phase and, embedded as a guest phase in the host phase, at least one pleochroic anthraquinone dye of the formula (1) <IMAGE> where R<1>, R<2>, R<3> and R<4> are each hydrogen, hydroxyl, amino or nitro, m is 1 or 2, n is zero, 1 or 2, R<5> and R<6> are identical or different and each is hydrogen or a radical of the formula (1a) or (1b) <IMAGE> where a is an integer from 1 to 10, b is zero or an integer from 1 to 6, and X is oxygen, sulphur, a single bond or oxycarbonyl, and R<7> is hydrogen, an alkyl or alkoxy group of 1 to 12 carbon atoms or a phenyl or phenoxy group.

Inventors

• 👤 Maged A. Dr. Osman
• 👤 Laszlo Dr. Révész
• 👤 Terry J. Dr. Scheffer
• 👤 Jürgen Dr. Markert

Bibliographic Details