Ferroelectric chiral smectic liquid crystal composition

Claim 2

A ferroelectric chiral smectic liquid crystal composition comprising (i) at least one member selected from the group consisting of liquid crystal compounds having a smectic C phase and no helical structure and liquid crystal compounds having only a nematic phase as a liquid crystal phase and no helical structure and (ii) at least one chiral smectic liquid crystal compound.

Claim 3

A ferroelectric chiral smectic liquid crystal composition according to claim 1 in which said at least one chiral smectic liquid crystal compound is at least one compound having a twist sense of helix left-handed and at least one compound having a twist sense of helix right-handed.

Claim 4

A ferroelectric chiral smectic liquid crystal composition according to claim 1 which comprises 1 -30% by weight of at least one liquid crystal compound having only nematic phase as liquid phase and no helical structure and 99-70% by weight of said at least one chiral smectic liquid crystal compound.

Claim 5

A ferroelectric chiral smectic liquid crystal composition according to claim 3 wherein said liquid crystal compound having only nematic phase as a liquid crystal phase and no helical structure, is a compound having a clearing point higher than 70°C but lower than 250°C.

Claim 6

A ferroelectric chiral smectic liquid crystal composition according to claim 1 which comprises 5 ~ 95% by weight of said liquid crystal compound having a smectic C phase and no helical structure and 99 ~ 5% by weight of said chiral smectic liquid crystal compound.

Claim 7

A ferroelectric chiral smectic liquid crystal composition according to claim 1 wherein said chiral smectic liquid crystal compound is an optically active compound represented by a general formula of (I) in which and each independently represent a benzene ring or a cyclohexane ring; m and n each independently are an integer of 1 or 2; X is -CH=N-, -CH 2 O-, -N=CH-, -OCH 3 - or a single bond; R 1 is an alkyl group of 1 ~ 18 carbon atoms or an alkyloxy group of 1 ~ 18 carbon atoms; Y is an alkyl group, an alkyloxy group, an alkoxy carbonyl group, an alkanoyl group or an alkanoyloxy group, having an asymmetric carbon atom.

Claim 8

A ferroelectric chiral smectic liquid crystal composition according to claim 1 wherein said liquid crystal compound having no helical structure is at least one compound selected from the group consisting of the following compound group represented by the general formula of (II) ~ (XIV); wherein each of R 2 and R 3 is an alkyl group having 1 ~ 18 carbon atoms; each of R 4 and R 5 is an alkyl, or alkoxy group having 1 ~ 18 carbon atoms; each of R 6 and R 7 is an alkyl group having 5 ~ 18 carbon atoms; R 8 is an alkyl or alkyloxy group having 5 ~ 18 carbon atoms; R 9 is an alkyl group having 6 ~ 9 carbon atoms or an alkyloxy group having 8 ~ 9 carbon atoms; R 10 is an alkyl or alkyloxy group having 6 ~ 10 carbon atoms; each of R 11 and R 12 is an alkyloxy group having 7 ~ 10 carbon atoms; R 13 is an alkyl or alkyloxy group having 7 ~ 9 carbon atoms; R 14 is an alkyloxy group having 7 ~ 9 carbon atoms; R 15 is an alkyloxy group having 5 ~ 7 carbon atoms; R 16 is an alkyl group having 4 ~ 8 carbon atoms; each of R 17 , R 18 and R 20 is an alkyl group having 7 ~ 18 carbon atoms; each of R 19 and R 22 is an alkyl group having 6 ~ 18 carbon atoms; R 21 is an alkyl or alkyloxy group having 5-18 carbon atoms; R23 is an alkyl or alkyloxy group having 6 ~ 18 carbon atoms; and R 24 is an alkyl group having 5 -18 carbon atoms.

Claim 9

A ferroelectric chiral smectic liquid crystal composition according to claim 1 in which said liquid crystal compound having a smectic C phase and no helical structure is at least one of the racemate of the compound represented by a general formula (I).

Claim 10

A light-switching element employing a ferroelectric chiral smectic liquid crystal composition comprising (i) at least one member selected from the group consisting of liquid crystal compounds having a smectic C phase and no helical structure and a liquid crystal compound having only a nematic phase as a liquid crystal phase and no helical structure and (ii) at least one chiral smectic liquid crystal compound.

Claim 11

A light-switching element employing a ferroelectric chiral smectic liquid crystal composition comprising (i) at least one member selected from the group consisting of liquid crystal compounds having a smectic C phase and no helical structure and a liquid crystal compound having only a nematic phase as a liquid crystal phase and no helical structure and (ii) at least one chiral smectic liquid crystal compound.