Silane couplers containing cyclic structural elements as alignment films

Abstract

An alignment film for liquid crystals comprising a quasi-monomolecular layer of compounds of the formula II C.sub.y --S.sub.p --A.sub.n (II) in which C .sub.y 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; S.sub.p is an alkyl group having from 1 to 20 carbon atoms, in which one or more non-adjacent --CH.sub.2 --groups may be replaced by --O--, --S--, --CO--, --O--CO--, --NH--CO--, --O--COO--, --NH--CO--NH--, --NH--CO--O--, --SO.sub.2 --, --Si(CH.sub.3).sub.2 --, --CH.dbd.CH-- or --C.tbd.C--; A.sub.n is SiX.sup.1 X.sup.2 X.sup.3, where X.sup.1 is a single bond, and X.sup.2 and X.sup.3, independently of one another, are a single bond or an alkyl or alkoxy group, where the compound of the formula (II) is bonded to an oxidic layer via the single bond(s) of the group A.sub.n. 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.

Dependencies are inferred from the claim text.