| 摘要 |
Liquid crystalline mixtures with at least two liquid-crystalline compounds free of perfluoro alkylene groups and at least one partially fluorinated additive of formula (I): R<1>-(CH2)m-(CF2)n-R<2>, wherein m is 0 to 12, n is 1 to 16 and R<1> and R<2> each signify a group of formula (II), in which R is F or alkyl with 1-15 C atoms, being possible for one or two non-adjacent CH2 groups to be replaced by -O-, -CO-, -O-CO-, -CO-O-, -O-CO-O-, -C=C- and/or -CH=CH-, A<1> and A<2> in each case an unsubstituted, mono- or polysubstituted 1,4-cyclohexylene group, also possible for one or two non-adjacent CH2 groups to be replaced by -O- and/or -S-; or a 1,4-bicyclo-[2,2,2]octylene group, or a 1,4-phenylene group unsubstituted or substituted by one or two F and/or Cl atoms and/or CH3 groups and/or CN groups, being possible for one or two CH groups to be replaced by N, Z<1> -CO-O-, -O-CO-, -CH2CH2-, -CHCN-CH2-, -CH2-CHCN-, -CH=CH-, -C=C-, -OCH2-, -CH2O, -CH=N-, -N=CH-, -N=N-, -NO=N-, -N=NO- or Z<2> -CO-O-, -O-CO-, -CH2CH2-, -CHCN-CH2, -CH2-CHCN-, -CH=CH-, -C=C-, -OCH2-, -CH2O-, -CH=N-, -N=CH-, -N=N-, -NO=N-, -N=NO-, -(CH2)k-CO-O- or k 1 to 6, p: 0, 1, 2; q: 0, 1. R<1> or R<2> may also be H, with the proviso that m+p+q = 1 to 15. Means of reducing the refractive indices of a L.C. mixture by adding one or more additives of formula (I). |
