It is an object of the present invention to provide a liquid crystal composition having positive Δ∈, having a liquid crystal phase in a wide temperature range, having high solubility at low temperatures, having high ODF process compatibility, having a high specific resistance and voltage holding ratio, and being insensitive to heat and light. In order to achieve this object, there is provided a liquid crystal composition containing at least one compound represented by the following general formula (i) and at least one compound represented by the following general formula (ii). ##STR00001## (wherein R.sup.i1 denotes an alkyl group having 2 to 5 carbon atoms) ##STR00002## (wherein R.sup.ii1 and R.sup.ii2 independently denote an alkyl group having 1 to 5 carbon atoms or an alkenyl group having 2 to 5 carbon atoms, and X.sup.ii1 and X.sup.ii2 independently denote a hydrogen atom or a fluorine atom)

As a material used in an element used for phase control of an electromagnetic wave signal having a frequency of 1 GHz to 10 THz, a liquid crystal composition is required, which has a high upper limit temperature of a nematic phase, a low lower limit temperature of a nematic phase, large dielectric anisotropy and a small tan δ in a frequency region where the phase control of an electromagnetic wave signal is performed, and stability against heat, and which has an excellent balance of the characteristics. A liquid crystal composition which is used in an element for phase control of an electromagnetic wave signal having any frequency from 1 GHz to 10 THz, the liquid crystal composition containing at least one compound selected from compounds represented by Formula (1) as a first component. ##STR00001##

The present invention provides a novel liquid crystal material composition comprising one or more compound, in order to achieve the properties of low viscosity, high resistivity, good low-temperature mutual solubility, fast response, excellent transmission, and which can be used for a variety of fast response display modes. Since the working temperature of a LCD material is subjected to the temperature range of individual LC molecules, information can only be displayed in a specific temperature range of the specific liquid crystal macro-alignment phase. At low temperature, the viscosity of liquid crystal increases exponentially, which in turn substantially reduces the response speed and overall performances of the display system. The liquid crystal composition according to the present invention overcomes these problems with balanced chemical composition by achieving low viscosity, good low-temperature performance and excellent transmission in a wide range of LCD applications including TN, IPS or FFS displays, thus improving display performance.

Provided is a liquid crystal composition satisfying at least one or having suitable balance regarding at least two of characteristics such as high maximum or low minimum temperature of a nematic phase, large optical anisotropy, large positive dielectric anisotropy and high stability to ultraviolet light, and a liquid crystal display device including such a composition, particularly an encapsulated liquid crystal display device, and a liquid crystal display device serving as a constituent of 3D lenses. The liquid crystal composition contains a specific compound having large optical anisotropy as a first component, and a specific compound having large optical anisotropy and large positive dielectric anisotropy as a second component; a specific compound having large positive dielectric anisotropy as a third component; and a specific compound having large optical anisotropy and further having high maximum or low minimum temperature as a fourth component, and the liquid crystal display device includes the composition.

The present invention relates to liquid-crystalline media comprising—one or more compounds of formulae CC and/or CP and—one or more compounds selected from the group of compounds of formulae (I), (II) and (III), 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.

##STR00001##

An object of the present invention is to provide a composition that has positive Δε, exhibits a liquid crystal phase over a wide temperature range, has low viscosity, excellent solubility at low temperatures, and high resistivity and voltage holding ratio, and is stable against heat and light. By using this composition, IPS or TN liquid crystal display devices and the like that have excellent display quality and suppress display failures such as image-sticking and drop marks are provided in high yield. Provided is a composition that contains at least one selected from the group consisting of compounds represented by general formulae (i) and (ii) and at least one compound represented by general formula (iii). Also provided is a liquid crystal display device that uses the composition and an IPS or FFS device that uses the composition.

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.

The present invention provides a liquid crystal composition having negative dielectric anisotropy, large refractive index anisotropy, and low viscosity and containing as a first component, one or two or more compounds represented by general formula (I) and, as a second component, one or two or more compounds represented by general formula (II), wherein dielectric anisotropy (Δ∈) at 25° C. is −2.0 or less. Also, provided is a liquid crystal display device having high contrast, fast response, and excellent display quality without causing image sticking and display defects.

Liquid-crystalline media comprising one or more compounds of formula T ##STR00001##
as defined in claim 1, and high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g. phased array antennas.

To provide a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and heat, or having a suitable balance regarding at least two of the characteristics; and an AM device having characteristics such as short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio and long service life. The composition has negative dielectric anisotropy and contains a specific compound having large negative dielectric anisotropy as a first component, a specific compound having small viscosity as a second component, and may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having negative dielectric anisotropy as a fourth component, or a specific compound having a polymerizable group as an additive component.