Patent ID: 7390539

Claim:
A composition having a negative dielectric anisotropy comprising a liquid crystal consisting essentially of at least one compound selected from a group of compounds represented by formula (1) as a first component, at least one compound selected from a group of compounds represented by formula (2) as a second component, at least one compound selected from a group of compounds represented by formula (3) as a third component and at least one compound selected from a group of compounds represented by formula (4) as a fourth component: wherein R 1 is alkyl or alkenyl; R 2 is alkyl or alkoxy; R 3 is alkyl or alkoxymethyl; R 4 is alkyl; A 1 is 1,4-cyclohexylene or 1,4-phenylene; A 2 is 1,4-cyclohexylene, 1,4-phenylene or 2-fluoro-1,4-phenhlene; and Z 1 is a single bond or —COO—.