Cyclische Strukturelemente enthaltende Silan-Koppler als Orientierungsfilme

摘要

An alignment (orientation) film for liquid crystals, comprising a quasi-monomolecular layer of compounds of the formula II Cy-Sp-An (II> in which Cy and Sp are as defined in the formula I, and Cy is a mediocyclic or macrocyclic carbon ring having 8 or more ring members, it also being possible for this ring to contain fused benzene rings and -O-, -N-, -S-, -Si- and -B- as heteroatoms; Sp is an alkyl group having 1 to 20 carbon atoms in which one or more non-adjacent CH2 groups may be replaced by -O-, -S-, -CO-, -O-CO-, -NH-CO-, -O-COO-, -NH-CO-NH-, -NH-CO-O-, -SO2-, -SI(CH3)2-, -CH=CH- or -C IDENTICAL C-; An is SiX<1>X<2>X<3>, where X<1> is a single bond and X<2> and X<3>, independently of one another, are a single bond or an alkyl or alkoxy group, where the compounds of the formula (II) are bonded to an oxidic layer via the single bond(s) of group An. The alignment films according to the invention are highly suitable for the alignment of liquid crystals, in particular ferroelectric liquid crystals. The low thickness of the alignment film prevents dielectric losses in the display. The occurrence of ghost images is substantially suppressed.