Cpds. for improving properties of pref. ferroelectric LC mixts.

摘要

Cpds. of formula (I) with multiple methyl branching are new: R<1>(-A<1>-M<1>)a(-A<2>-M<2>)b(-A<3>-M<3>)c(-A<4>)-G(C<*>H(CH3)-CH2) n-R2 (I); A<1>-A<4> = 1,4-phenylene (opt. contg. one or more H atoms replaced by F, Cl and/or CN), pyrazine-2,5-diyl (opt. contg. 1-2H atoms replaced by Fl, Cl, and/or CN), pyridazine-3,6-diyl (opt. contg. 1-2H atoms replaced by Fl, Cl and/or CN), pyridine-2,5-diyl (opt. contg. one or more H atoms replaced by F, Cl and/or CN), pyrimidine-2,5-diyl (opt. contg. 1-2H atoms replaced by F, Cl and/or CN), trans-1,4-cyclohexylene (opt. contg. 1-2H atoms replaced by CN and/or CH3) (1,3,4)-thiazole-2,5-diyl, 1,3-dioxane-2,5-diyl, 1,3-dithiane-2,5-diyl, 1,3-thiazole-2,4-diyl (opt. contg. 1 H atom replaced by F, Cl and/or CN), 1,3-thiazole-2,5-diyl (opt. contg. 1 H atom replaced by F, Cl and/or CN), thiophene-2,4-diyl (opt. contg. 1 H atom replaced by F, Cl and/or CN), thiophene-2,5-diyl (opt. contg. 1-2 H atoms replaced by F, Cl and/or CN) or naphthalene-2,6-diyl(opt. contg. one or more H atoms replaced by F, Cl, and/or CN); <*>C = chiral C atom; G = -CO-O-CH20, -CO-O-, -O-CO-, -O-CO-O-CH2-, -O-CO-O-, -O-CH2-, O, S or single bond; G' = -CO-O-, -CH2-O- or single bond; M<1> - M<4> = -CO-O-, -O-CO-, -O-CO-O-, -CH2-O-, -O-CH2-, -CH2-S-, -S-CH2-, -CH=CH- or single bond; R<1> = optically active or racemic gp. of formula (1)-(9) H, CN, F, Cl, CF3, CHF2, CH2F, OCF3, OCHF2, 1-30C alkyl (opt. contg. one or more CH2 gps. replaced by O, S, -CO-O-, -O-CO-, -O-CO-O-, CO, CS, -CH=CH-1 or -C?=C - cyclopropane-1,2-diyl -Si(CH3)2-, 1,4-phenylene, trans-1,3-cyclohexylene or trans-1,3-cyclopentylene), with the provision that O and/or S atoms are not bonded to each other, and/or /- one H atoms in the alkyl gp. may be replaced by F, Cl, Br, -OR3, -SCN, -OCN or N3 R<2> = 1-6C n-alkyl; R<3>,R<6>,R<7> = H or 1-16C alkyl ,opt. contg. one or more CH2 gps. replaced by O and/or -CH=CH- with the provision that the O atoms are non-adjacent, and one or more H atoms in the alky gp. may be replaced by F or Cl; R<4>,R<5> = R<3> or they may be -(CH2)4- or -(CH2)5- when bonded to an oxirane, dioxolane or tetrahydrofuran system; a-c = 0-1; (a+b+c) = 1-3; and n = 2-6; Also claimed are (i) liq. crystals mixts. (LCM) contg. one or more cpds. (I) and (ii) switch and/or display devices comprising carrier plates, electrode, /- one polariser, /- one orientation layer and (LCM).