New 4,4,4-tri:fluoro-butyl ether(s) of 2,6-di:fluoro:benzene cpds. used in LCD

摘要

Liquid crystal (LC) medium based on a mixt of polar cpds.with positive dielectric anisotropy contains ether(s) of formula (I). R = H, 1-15C alk(en)yl, opt with one CN or CF3 or at least one halogen substit in which 1 or more CH2 gps may be replaced by -O-, -S-, cyclobutan-1,3-diyl, -CO-, -CO-O-, -O-CO- or -O-CO-O- without directly linked O atoms; A<1>, A<2> = (a) trans-1,4-cyclohexylene (Cyc), in which one or more non-adjacent CH2 gps may be replaced by -O- and/or -S-; (b) 1,4-phenylene (Phe), in which 1 or 2 CH gps may be replaced by N; (c) 1,4-cyclohexenylene, 1,4-bicyclo(2,2,2)-octylene, piperidin-1,4-diyl, naphthalene-2,6-dilyl, decahydronaphthalen-2,6-diyl and 1,2,3,4-tetrahydronapthalen-2,6-diyl; and gps (a) and (b) may be mono- or di-substd by F; Z<1>, Z<2> = -CO-O-, -O-CO-, -CH2O-, -OCH2-, -CH2CH2-, -CH=CH-, -C?=C- or a single bond and one of Z<1> and Z<2> may also = -(CH2)4- or -CH=CH-CH2CH2-; L<1>, L<2> = H or F; m = 0, 1 or 1; n = 0 or 1. Also claimed are new (I; A<2> = 2-fluoro-1,4-phenylene (Phe-F) or 2,6-difuoro-1,4-phenylene (Phe-2F) with Z<2> = a single bond in the 1-position), esp (I; A<1> = Cyc; A<2> = Ph-F or Phe-2F; Z<1>, Z<2> = single bond); and the cpd 4,4,4-trifluoro-n-butyl 4-bromo-2,6-difluorophenyl ether (II) per se.