Liquid crystal medium with positive dielectric anisotropy, used in electrooptical e.g. twisted nematic, thin film transistor or optically compensated bent display, contains pyranyl-benzene and fluoro-phenyl or -terphenyl or ester compounds

摘要

Liquid crystal (LC) medium based on a mixture of polar compounds with positive dielectric anisotropy contains tetrahydropyran-2- or -3-yl or 3,6-dihydropyran-2-yl-benzene compounds (I), optionally with a bridge and/or other rings, and compound(s) selected from 3,5-difluoro-4-substituted-phenyl compounds, 4-substituted phenyl 4-cyclohexylbenzoates and 3,3'-difluoroterphenyl compounds. Liquid crystal (LC) medium based on a mixture of polar compounds with positive dielectric anisotropy contains pyran compound(s) (I) and compound(s) selected from 1-(trans-4-cyclohexyl-cyclohexyl)-3,5-difluoro-4-substituted-benzenes, biphenylyl-difluoromethyl 3,5-difluoro-4-substituted-phenyl ethers, 1-(trans-(tetrahydropyran-2-yl)-cyclohexyl-difluoromethyl 3,5-difluoro-4-substituted-phenyl ethers, 4-substituted phenyl 4-cyclohexylbenzoates and 3,3'-difluoroterphenyl compounds of formulae (C'), (C-4) and (C-5). R, R 1H or 1-15 C (halo)alkyl or (halo)alkoxy, in which 1 or more CH 2 groups may be replaced by -Ctriple boundC-, -CH=CH-, -O-, -CO-O- or -O-CO- with no directly linked O atoms; rings A, B : trans-1,4-cyclohexylene, 1,4-phenylene, 3-fluoro- or 3,5- or 2,3-difluoro-1,4-phenylene, 1,4-cyclohex-3-enylene, 2,5-dihydropyran-3,6-diyl, tetrahydropyran-2,5- or 3,6-diyl, bicyclo[2.2.2]octan-1,4-diyl, 3-fluoro-1,4-cyclohex-3-enylene or 1,3-dioxan-2,5- or -5,2-diyl; P : tetrahydropyran-3,6- or 2,5-diyl or 2,5-dihydropyran-3,6-diyl; Z 1, Z 2-COO-, -OCO-, -CH 2O-, -OCH 2-, -CH=CF-, -CF=CH-, -CF 2-CF 2-, -CF=CF-, -Ctriple boundC-, -CH 2CH 2-, -(CH 2) 4-, -CH=CH- or a single bond; X, X 1F, Cl, CN, SF 5, NCS, 1-8 C haloalkyl, in which CH 2 group(s) may be replaced by -O- or -CH=CH- without directly linked O atoms; L 1-L 6H or F; Q : 4,4'-bi-cyclohexylene, a group of formula (a') or -3,6-tetrahydropyranyl-1,4-cyclohexylene; m, n : 0-3 to a total m+n less than 3. [Image] [Image] [Image] [Image].