摘要 |
Novel liquid crystal materials are provided having the general formula <IMAGE> where A is a 4-alkylphenyl group and B is a 2-(6-alkyl)naphthyl group, or vice versa, wherein the alkyl groups in A and B may be the same or different. These materials have a dielectric anisotropy sign change at moderate frequencies, i.e., in the range 1kHz to 50kHz and are thus useful for twisted nematic device cells of the frequency switching type. |