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.

There is provided a liquid crystal display device which enables reductions in image sticking and droplet stains caused in production thereof without degradation of properties such as dielectric anisotropy, viscosity, the upper limit of the temperature of nematic phase, and rotational viscosity (γ.sub.1); and there is also provided a method for manufacturing such a liquid crystal display device. The liquid crystal display device is characterized in that a liquid crystal layer containing a liquid crystal composition is disposed between a substrate provided with a common electrode and a color filter layer and another substrate provided with a plurality of pixels each having a pixel electrode, each of the substrates is not provided with an alignment film but provided with an orientation controlling layer composed of at least two polymerizable compounds, each of the pixels has two or more regions having different directions of pretilt, and the liquid crystal composition contains a compound represented by General Formula (I) and a compound represented by General Formula (II).

A liquid-crystal medium containing a component A of one or more compounds of formula X ##STR00001##
the preparation thereof, and the use of these liquid-crystal media, in particular in components for high-frequency technology, and components of this type which contain the media, and the production and use of these components. The components are suitable for phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and for tuneable reflectarrays.

Liquid-crystalline media comprising one or more compounds of formula G ##STR00001##
and one or more compounds selected from the group of compounds of formulae I, II and III, ##STR00002##
in which the parameters have the meaning indicated in claim 1, and components comprising these media, are suitable for use in high-frequency technology, in particular, in phase shifters and microwave array antennas.

The present invention discloses a compound of which a structural formula thereof is represented as the following formula: ##STR00001##
The compound disclosed by the present invention can be used as a liquid crystal compound and overcomes the problem that solubility of the traditional dibenzothiophene-class liquid crystals is poor, and thus can be better applied to the liquid crystal material field. The present invention further discloses a liquid crystal medium containing the compound and an application thereof.

A liquid crystal dielectric applicable to high-frequency electromagnetic wave modulation has a clearing point of the liquid crystal dielectric higher than 110° C., a low-temperature storage temperature lower than −20° C., and an optical anisotropy greater than 0.35. The liquid crystal dielectric includes: one or more compounds selected by general formula I, which occupy 30-80% of the total weight of the liquid crystal dielectric, and one or more compounds selected by general formula II and/or general formula III, which occupy 20-70% of the total weight of the liquid crystal dielectric. The liquid crystal dielectric has good low-temperature stability, high dielectric anisotropy, a high phase width, appropriate rotary viscosity, appropriate optical anisotropy, low dielectric loss, and a low loss tangent, exhibits strong high-frequency electromagnetic wave tuning capability, is specifically suitable for electromagnetic wave modulation in microwave or millimeter wave areas, and has a good application prospect in liquid crystal phase shifters. ##STR00001##

The present invention relates to aromatic isothiocyanates of formula U ##STR00001##
as defined in claim 1, to liquid-crystalline media comprising one or more compounds of formula U and to 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.

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. ##STR00001##

A liquid crystal composition, which is a material used for an element for electromagnetic wave signal control in a frequency range of 1 GHz to 10 THz, satisfies at least one of characteristics such as a wide temperature range of a nematic phase and a large refractive index anisotropy and a small dielectric loss tangent (tan δ) in the frequency region used for control, and has an excellent balance of characteristics, and an element containing the composition. A liquid crystal composition including: at least one compound selected from the group consisting of compounds represented by Formula (1). For example, R.sup.1 is C1-12 alkyl; Z.sup.11 is a single bond; L.sup.11, L.sup.12, L.sup.13 and L.sup.18 are hydrogen; L.sup.17 is methyl; Y.sup.11 and Y.sup.22 are hydrogen; and a, b, and c are respectively 0, 1, and 0.

##STR00001##

A material used in an element for phase control of an electromagnetic wave signal having a frequency of 1 GHz to 10 THz. A liquid crystal composition containing at least one compound selected from a group of compounds represented by Formula (1), at least one compound selected from a group of compounds represented by Formula (2) and at least one compound selected from a group of compounds represented by Formula (3).

##STR00001##

For example, R.sup.1, R.sup.21, R.sup.22, R.sup.31, and R.sup.32 are alkyls having 1 to 12 carbon atoms; a ring A.sup.1 is 1,4-phenylene; Z.sup.11, Z.sup.13, Z.sup.21, Z.sup.23, Z.sup.31, and Z.sup.33 are single bonds; Z.sup.12, Z.sup.22, and Z.sup.32 are —C≡C— or —C≡C—C≡C—; L.sup.13 to L.sup.16, L.sup.21 to L.sup.23, and L.sup.31 to L.sup.36 are hydrogen or fluorine; Y.sup.11 and Y.sup.12 are hydrogen or fluorine; and n.sup.1 is 0.