| 摘要 |
A liquid crystal composition having at least one or a suitable balance regarding at least two of characteristic such as high maximum temperature of a nematic phase, low minimum temperature thereof, small viscosity, suitable optical anisotropy, large dielectric anisotropy, large specific resistance, high stability to ultraviolet-light or heat, or large elastic constant; an AM-device having short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio, a negatively large DC brightness relaxation time constant and long-service-life. The liquid crystal composition contains a compound contributing to high stability to heat or ultraviolet-light as an additive component and a specific compound having positively large dielectric anisotropy, and a liquid crystal display device includes the composition. The composition may contain a specific compound having high maximum temperature or small viscosity as a second component or a specific compound having negative dielectric anisotropy as a third component. |
| 主权项 |
1. A liquid crystal composition that has a positive dielectric anisotropy and a nematic phase, and contains at least one compound selected from the group of compounds represented by formula (1) as an additive component and at least one compound from the group of compounds represented by formula (2) as a first component:wherein, in formula (1), R1 is hydrogen or alkyl having 1 to 15 carbons; R2, R3, R4 and R5 are independently hydrogen or alkyl having 1 to 4 carbons; ring A is a polyvalent group derived from benzene or cyclohexane by eliminating hydrogen; a is 3 or 4; and
in formula (2), R6 is alkyl having 1 to 12 carbons, alkoxy having to 12 carbons or alkenyl having 2 to 12 carbons; ring B is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; Z1 is a single bond, ethylene, carbonyloxy or difluoromethyleneoxy; X1 and X2 are independently hydrogen or fluorine; Y1 is fluorine, chlorine, alkyl having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine, alkoxy having 1 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine, or alkenyloxy having 2 to 12 carbons in which at least one of hydrogen is replaced by fluorine or chlorine; and b is 1, 2, 3 or 4. |
