Patent ID: 8585924

Claim:
A compound represented by formula (1-1): wherein R 1 and R 2 are independently hydrogen, alkyl having 1 to 10 carbons, alkenyl having 2 to 10 carbons, alkoxy having 1 to 9 carbons, alkoxyalkyl having 2 to 9 carbons or alkenyloxy having 2 to 9 carbons; ring A 1 and ring A 2 are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,3-difluoro-1,4-phenylene; Z 1 and Z 2 are independently a single bond, —(CH 2 ) 2 —, —CH 2 O—, —OCH 2 —, —COO— or —OCO—; >W 1 —W 2 — and >W 4 —W 3 — are independently >CH—CH 2 — or >C═CH—; and m and n are independently 0, 1 or 2, and the sum of m and n is 1 or 2.