PURPOSE: To prepare a ferroelectric liq. crystal compsn. having a rapid response and useful for an optical switching element, by incorporating a particular compd. having negative dielectric anisotropy.
CONSTITUTION: This liq. crystal compsn. comprises at least one compd. of formula I having negative dielectric anisotropy. In the formula, R1 and R2 which may be the same or different are each a 1W18C straight-chain or branched alkyl, X and Y are independently -F, -Cl, -Br or -CN, formulas II and III are independently formula IV or V, m and n are each 0 or 1, and m+n is 1 or 2. The compd. of formula I is characterized by having very large dielectric anisotropy because it has a large dipole moment in the direction of a minor axis of the molecule. Example of the compd. include a non-chiral compd. having two CN groups on the same side and represented by formula VI (wherein R3 and R4 are each a 1W18C straight-chain or branched alkyl; and l is 1 or 2).
ICHIHASHI MITSUYOSHI
KIKUCHI MAKOTO
TAKESHITA FUSAYUKI
FURUKAWA KENJI
Next Patent: DATA TRANSMISSION SYSTEM