Nematic liquid crystal compositions

摘要

Nematic liquid crystal compositions for use in displays and in other liquid crystal applications comprising a mixture of a nematic biphenyl liquid crystal material, nematic liquid crystal material other than nematic biphenyl which is incompatible with the nematic biphenyl (e.g. when mixed together, it will form a smectic phase instead of a nematic phase) which is present in a concentration that will render the total mixture with improved electro-optic properties and nematic liquid crystal material other than a nematic biphenyl which is compatible with the nematic biphenyl and present in a concentration sufficient so that the mixture forms a satisfactory nematic phase for use in a field-effect display device. The preferred biphenyl-incompatible constituents are certain ester-type nematic liquid crystals and the biphenyl-compatible constituent are other certain ester-type nematic liquid crystal. Further preferred embodiments are the selection of positive dielectric anisotropic (PDA) materials and negative dielectric anisotropic (NDA) materials and the inclusion of certain chiral additives. These liquid crystal mixtures exhibited very good electro-optic characteristics (e.g. low threshold voltages and fast response times).