There is provided a liquid crystal composition including at least one compound represented by General Formula (i) and at least one compound represented by General Formula (N). The total amount of the compound represented by General Formula (i) is 10% by mass or greater. In the liquid crystal composition and the liquid crystal display element using the composition, the liquid crystal composition has a positive Δ∈ and a flat transmission characteristic curve. Therefore, gradation characteristics are easily controlled. Furthermore, display defects due to burn-in, dropping marks, and the like can be suppressed, and therefore excellent display quality is exhibited. The liquid crystal display element using this liquid crystal composition can be also provided.

The present invention relates to liquid-crystalline media comprising one or more pleochroic dyes and one or more compounds selected from the group of compounds of formulae I, II and III,

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in which the parameters have the meaning indicated in Claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

The invention relates to a liquid crystal compound having the structure of formula I wherein R is selected from the group consisting of H and alkyl or alkoxy groups of 1 to 12 carbon atoms in which one or more H are unsubstituted or substituted with halogen; A.sub.1 is selected from the group consisting of a single bond or a 1,4-phenylene group in which each H in the 1,4-phenylene group is independently substituted by one or more halogen atoms; L.sub.1 and L.sub.2 are each independently selected from H or halogen; Z.sub.1 is a single bond or —(CH.sub.2).sub.2—. The compound has advantages of low rotational viscosity, large dielectric anisotropy, good mutual solubility and stability, which can be added to LC composition to reduce the driving voltage of the display. Thus, the novel compound has prosperous applications in LCD industry.

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The invention relates to a liquid crystal compound having the structure of formula I wherein R is selected from the group consisting of H and alkyl or alkoxy groups of 1 to 12 carbon atoms in which one or more H are unsubstituted or substituted with halogen; A.sub.1 is selected from the group consisting of a single bond or a 1,4-phenylene group in which each H in the 1,4-phenylene group is independently substituted by one or more halogen atoms; L.sub.1 and L.sub.2 are each independently selected from H or halogen; Z.sub.1 is a single bond or —(CH.sub.2).sub.2—. The compound has advantages of low rotational viscosity, large dielectric anisotropy, good mutual solubility and stability, which can be added to LC composition to reduce the driving voltage of the display. Thus, the novel compound has prosperous applications in LCD industry.

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To provide a liquid crystal display device, whereby transparency when no voltage is applied and scattering properties when a voltage is applied, are good, adhesion between a liquid crystal layer and a vertical liquid crystal alignment film is high, and its lifespan is long even in a severe environment. The liquid crystal display device has a liquid crystal layer formed by disposing a liquid crystal composition containing a liquid crystal and a polymerizable compound between a pair of substrates provided with electrodes, and irradiating and curing the composition with ultraviolet rays by an ultraviolet irradiation apparatus, and at least one of the substrates is provided with a liquid crystal alignment film to vertically align a liquid crystal, wherein the ultraviolet irradiation apparatus is an ultraviolet irradiation apparatus capable of controlling the irradiation light intensity and wavelength of the ultraviolet rays to be irradiated and the surface temperature of the pair of the substrates, the liquid crystal composition contains a compound represented by the formula [1], and the liquid crystal alignment film is a liquid crystal alignment film obtained from a liquid crystal alignment treating agent containing a polymer having a side chain structure represented by the formula [2-1] or formula [2-2].

X.sup.1-X.sup.2-X.sup.3-X.sup.4-X.sup.5-X.sup.6X.sup.7.sub.pX.sup.8  [1]

(X.sup.1 is a specific side chain structure; X.sup.2, X.sup.3, X.sup.4 and X.sup.6 are each a single bond, etc.; X.sup.5 and X.sup.7 are each a benzene ring, etc.; p is an integer of from 0 to 4; and X.sup.8 is a C.sub.1-18 alkyl group, etc.),

—Y.sup.1-Y.sup.2-Y.sup.3-Y.sup.4Y.sup.5.sub.nY.sup.6  [2-1]

(Y.sup.1, Y.sup.2 and Y.sup.3 are each a single bond; Y.sup.4 and Y.sup.5 are each a benzene ring, etc.; n is from 0 to 4; and Y.sup.6 is a C.sub.1-18 alkyl group, etc.,

—Y.sup.7-Y.sup.8  [2-2]

(Y.sup.7 is a single bond; and Y.sup.8 is a C.sub.8-22 alkyl group, etc.).

There is provided a liquid crystal composition which enables a significant reduction in crystallization temperature as compared with addition of a homolog while having a similar skeleton structure, which has an excellent compatibility, and which enables an increase in the absolute value of negative dielectric anisotropy (Δ∈). The liquid crystal composition contains two or more compounds which each have two to four ring structures between two side chains. At least one of the ring structures is a 2,3-difluorobenzene skeleton. The two side chains are bonded to different ring structures. The positions of the 2,3-difluorobenzene skeletons are different from each other, and the number of the ring structures are the same as each other.

The present invention relates to the technical field of liquid crystal displays, and particularly relates to a liquid crystal composition containing a 2-methyl-3,4,5-trifluorobenzene liquid crystal compound and use thereof, wherein the liquid crystal composition of the present invention comprises, in percentages by weight, 1-50% of one or more compounds represented by general formula I and 10-70% of one or more compounds represented by general formula II, and may further comprise 0-30% of compounds represented by general formula III and/or 6-45% of one or more compounds represented by general formulas IV to XIII The liquid crystal composition provided by the present invention has a low rotational viscosity and a large elastic constant, is presented as having a shorter response time, and can significantly improve the display effect of a liquid crystal display when applied to TN, IPS and FFS mode displays.

The invention relates to a liquid-crystalline medium, in particular based on a mixture of polar compounds, and to the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PA-VA, PALC, FFS, PS-FFS, IPS or PS-IPS effect.

A liquid-crystalline medium, in particular based on a mixture of polar compounds, having compounds of formulae Y, CY, PY and/or LY, and compounds of formula S1 and/or S2:

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The present invention provides a compound represented by general formula (1) as well as a liquid crystal composition containing this compound and a liquid crystal display using this liquid crystal composition. Using the compound represented by general formula (1) as a component of a liquid crystal composition makes it possible to obtain a liquid crystal composition having a low viscosity (η), a high Δn, suitable T.sub.-i, high miscibility with other liquid crystal compounds, and presenting a liquid crystal phase over a wide temperature range. This is therefore extremely useful as a structural component of a liquid crystal composition for a liquid crystal display requiring a high speed response.