Patent ID: 7749576

Claim:
A liquid crystal composition comprising 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 formulae (2) to (4) as a second component, and at least one compound selected from a group of compounds represented by formulae (5) to (7) as a third component, having a positive dielectric anisotropy, and having a nematic phase: wherein R 1 is alkyl; R 3 is alkyl or alkenyl; R 4 is alkyl, alkenyl or alkenyl having arbitrary hydrogen substituted by fluorine; R 5 is alkyl or alkoxy; R 6 is alkyl or alkoxymethyl; R 11 and R 12 are alkyls having different carbon numbers; A 1 and A 6 are independently 1,4-cyclohexylene or 1,4-phenylene; A 2 is 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl or 1,4-phenylene; A 3 is 1,4-cyclohexylene, 1,3-dioxane-2,5-diyl, 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,6-difluoro-1,4-phenylene; A 4 is 1,4-cyclohexylene, 1,4-phenylene or 2-fluoro-1,4-phenylene; A 5 is 1,4-phenylene, 2-fluoro-1,4-phenylene or 2,6-difluoro-1,4-phenylene; A 7 is 1,4-phenylene or 2-fluoro-1,4-phenylene; Z 1 is a single bond, —(CH 2 ) 2 —, —CF 2 O— or —COO—; Z 2 is a single bond or —(CH 2 ) 2 —; Z 3 is —CF 2 O—; Z 4 is a single bond or —COO—; X 1 and X 2 are independently hydrogen or fluorine; Y 1 is fluorine, chlorine, —OCF 3 or —OCF 2 H; and Y 2 is fluorine or chlorine; and wherein the second component at least includes a compound selected from the group of compounds represented by formula (4).