Liquid crystal medium for electro-optical use contains compounds with two ethylene- or butylene-linked cyclohexane rings attached to a fluorinated 4-trifluoro-methoxyphenyl group, optionally by a connecting group

摘要

A liquid crystal medium contains compounds with the following groups linked in the sequence (1) optionally 4-substituted cyclohexyl, (2) ethylene or butylene, (3) trans-1,4-cyclohexylene or -cyclohexenylene, (4) a single bond or a connecting group such as ester or ethylene, (5) 3-fluoro- or 3,5-difluoro-4-trifluoromethoxyphenyl. A liquid crystal (LC) medium, based on compounds with positive dielectric anisotropy, contains one or more compounds of formula (I). [Image] R : H or 1-15C alkyl or alkenyl (optionally substituted with one CN or CF3 group or with at least one halogen, and optionally with one or more CH2 groups replaced by O, S, 1,3-cyclobutylene-CO, COO, OCO or OCOO with no direct bonds between oxygen atoms); L : H or F; A : trans-1,4-cyclohexylene (optionally with one or two CH2 groups replaced by O and/or S) or cyclohexenylene; Z : COO, CH2CH2, CH2O, OCF2, CF2O, OCH2, (CH2)4 or a single bond; and n : 1 or 2 An independent claim is also included for electro-optical LC displays containing the LC medium.