PURPOSE: To provide a liquid crystal which has spontaneous polarization at least equal to that of conventional liquid crystal compsn. and has ferroelectricity over a temp. range wider than that of conventional ones, containing a specified optically active Schiff base compd.
CONSTITUTION: A liquid crystal contains a 4-(4'-alkoxybenzylideneamino)-cinnamate of formula I (wherein R1 is a 1W18C alkyl; R2 is an optically active halogenated 4C or higher alkyl, an optically active halogenated aralkyl; Y is H, CH3). The compd. of formula I has spontaneous polarization at least equal to that of the compd. of formula II and has ferroelectricity over a temp. range wider than that of the compd. of formula II which has ferroelectricity over the widest temp. range among conventional compds. The compd. of formula I can be obtd. by a dehydration-condensation reaction between a p-aminocinnamate of formula III (wherein R3 is a residue of an amino acid; X is halogen; Y is H, CH3) and a p-n-alkoxybenzaldehyde of formula IV (wherein R1 is as defined above).
HONMA MASAO
MIKAMI NAOKO
