Patent ID: 8574455

Claim:
A liquid crystal compound represented by formula (1) R 1 -(A 1 -Z 1 ) a -(A 2 -Z 2 ) b -(A 3 -Z 3 ) c -A 4 -(CH 2 ) n —CF═CF—R 2 (1) wherein R 1 is a hydrogen atom, or an alkyl group having 1 to 10 carbons, R 2 is a halogen atom or an alkyl group having 1 to 10 carbons, at least one hydrogen atom in the alkyl group in R 1 and R 2 is optionally substituted with a halogen atom, and an ethereal oxygen atom or a thioethereal sulfur atom is optionally inserted between carbon-carbon atoms in the alkyl group or at a bond end of the alkyl group, A 1 , A 2 , A 3 and A 4 independently represent a phenylene group or a cyclohexylene group, wherein one or two —CH═ in the groups of A 1 , A 2 , A 3 and A 4 is optionally substituted with a nitrogen atom; and one or two —CH 2 — in these groups is optionally substituted with an ethereal oxygen atom or an thioethereal sulfur atom, Z 1 , Z 2 and Z 3 independently represent a single bond, —O—, —S—, or a divalent aliphatic hydrocarbon group having 1 to 4 carbons, wherein at least one hydrogen atom in the aliphatic hydrocarbon group is optionally substituted with a halogen atom, and an ethereal oxygen atom or a thioethereal sulfur atom is optionally inserted between carbon-carbon atoms in the aliphatic hydrocarbon group or at a bond end of the aliphatic hydrocarbon group, a, b, c independently represent 0 or 1, wherein a+b+c is 1 or greater, n is 0 or 2, wherein when A 4 is a phenylene group, n is 2, and when A 4 is a cyclohexylene group and n=0, R 2 is an alkyl group having 1 to 10 carbons.