A liquid crystal composition includes at least one compound of general formula I and at least one compound selected from a group consisting of the compounds of general formula II-1 and general formula II-2. The liquid crystal composition provided by the present invention has suitable optical anisotropy, high clearing point, high elastic constants K.sub.11 and K.sub.33, and relatively low dielectric anisotropy. When the liquid crystal composition is applied to a liquid crystal display device, the liquid crystal display device may have better weather resistance and higher contrast ratio. ##STR00001##

The disclosure provides a liquid crystal device including a liquid crystal composition containing a dichroic dye (dye-containing liquid crystal composition) that is in a light transmissive state when no voltage is applied to the transparent electrode and in a light scattering state when voltage is applied. The liquid crystal composition exhibits a negative dielectric constant anisotropy. The haze value of the liquid crystal device is 10% or less when no voltage is applied at 25° C., and the haze value is 50% or more when a rectangular wave voltage (AC 50 V, 60 Hz) is applied. The voltage holding ratio of the dye-containing liquid crystal composition is 60% or less at 25° C. The liquid crystal device provided by the disclosure is used as a component to provide a liquid crystal display apparatus, a light control apparatus, or a light transmitting apparatus with a high contrast.

A liquid crystal composition containing a dibenzo derivative comprising a compound of general formula I and a compound of general formula II, and a liquid crystal display device containing the same, are disclosed. The liquid crystal composition is characterized by its excellent physical properties with respect to a liquid crystal display. The liquid crystal display device containing the liquid crystal composition has a good transmittance and a high contrast. ##STR00001##

A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH,

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in which Z.sup.1 denotes a single bond, —CH.sub.2CH.sub.2—, —CH═CH—, —CH.sub.2O—, —OCH.sub.2—, —CF.sub.2O—, —OCF.sub.2—, —COO—, —OCO—, —C.sub.2F.sub.4—, —(CH.sub.2).sub.4—, —CHFCHF—, —CF.sub.2CH.sub.2—, —CH.sub.2CF.sub.2—, —C≡C—, —CF═CF—, —CH═CHCHO— or —CH.sub.2CF.sub.2O—,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

The present invention relates to a liquid crystalline medium comprising dichroitic dyes made of benzothiadiazoles and related extended heterocyclic derivatives, the use of said medium for optical, electro-optical and electronic purposes, in particular in devices for regulating the passage of radiation energy from an outside space into an inside space, for example in windows. The invention further relates to devices containing the liquid crystalline medium according to the invention. Some new dichroitic dyes are disclosed.

The present invention relates to a liquid-crystal medium which comprises one or more compounds each of formulae I and II

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in which the occurring groups and parameters have the meanings given in claim 1.

The present invention relates to benzotriazole derivatives selected from the group of compounds of formulae Ia, Ib and Ic as defined in claim 1, to mesogenic media comprising the compounds of formulae Ia, Ib and Ic, and to the use of these compounds and mesogenic media in optical, electronic and electro-optical applications, in particular in devices for regulating the passage of energy from an outside space into an inside space, for example in windows.

A liquid-crystalline media (LC media) containing a low-molecular-weight, non-polymer component, and a combination of self-alignment additives for vertical alignment of two or more of the specified kinds (formulae IA to IM). The combination of two or more self-alignment additives affect homeotropic (vertical) alignment of the LC media at a surface or the cell surfaces of a liquid-crystal display (LC display).

Provided are an alignment aid that sufficiently exerts an alignment control force causing liquid crystal molecules to be vertically aligned and can reduce a change in pretilt angle over time, a liquid crystal composition containing the alignment aid, and a liquid crystal display device. The alignment aid of the present invention has the function of causing the liquid crystal molecules to be aligned spontaneously. In the light absorption spectrum of the alignment aid, the longest wavelength at which the absorbance is 0.5 is 330 nm or shorter. Preferably, the light absorption spectrum is measured on a solution prepared by dissolving the alignment aid in tetrahydrofuran at a concentration of 1000 ppm.

A liquid crystal composition includes at least one compound of general Formula I, at least one compound of general Formula II and at least one compound of general Formula M. The polymerizable liquid crystal composition provides a higher VHR (especially an excellent VHR after UV irradiation), a lower surface roughness of the polymer layer, a faster polymerization rate, a lower residual amount of the polymerizable compound and a better pretilt angle stability, which enables the production of a liquid crystal display device with a better voltage stability and a faster response speed, and can effectively reduce or prevent the occurrences of problems such as “burn-in”, “image sticking”, “Zara Particle” and “uneven display” in the liquid crystal display device. A liquid crystal display includes the liquid crystal composition.

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