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.

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##

The present invention relates to liquid-crystal (LC) media as defined in claim 1, having negative dielectric anisotropy and to the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays.

The present invention relates to a compound of formula T

##STR00001##

as defined in claim 1, to a liquid crystal medium comprising a compound of formula T 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##

There is provided an element which has large dielectric anisotropy and low dielectric loss in a high frequency range, has high reliability, and is used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz. An element in which a liquid crystal composition contains a compound represented by the following Formula (1) and has a refractive index anisotropy of 0.30 or more at a wavelength of 589 nm, and a polyimide alignment film contains 10% or more of a repeating unit represented by the following Formula (2) with respect to all repeating units:

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A liquid crystal compound represented by general formula F is useful as a liquid crystal composition and as a liquid crystal display device that contains the liquid crystal composition. The liquid crystal compound has a large clearing point, large optical anisotropy and sizable or large dielectric anisotropy absolute value under the condition of maintaining a suitable rotary viscosity, enabling the liquid crystal composition that contains the compound represented by general formula F has a large optical anisotropy, small rotational viscosity, high VHR (UV) and long low-temperature storage duration under the condition of maintaining proper clearing point, proper dielectric anisotropy absolute value and proper VHR (initial), and the liquid crystal display device that contains the liquid crystal composition of the present invention has good contrast, high response speed, high reliability and good low-temperature storage stability.

The present invention relates to liquid-crystal (LC) media as defined in claim 1, having negative dielectric anisotropy and to the use thereof for optical, electro-optical and electronic purposes, in particular in LC displays.

A liquid crystal compound represented by general formula F is useful as a liquid crystal composition and as a liquid crystal display device that contains the liquid crystal composition. The liquid crystal compound has a large clearing point, large optical anisotropy and sizable or large dielectric anisotropy absolute value under the condition of maintaining a suitable rotary viscosity, enabling the liquid crystal composition that contains the compound represented by general formula F has a large optical anisotropy, small rotational viscosity, high VHR (UV) and long low-temperature storage duration under the condition of maintaining proper clearing point, proper dielectric anisotropy absolute value and proper VHR (initial), and the liquid crystal display device that contains the liquid crystal composition of the present invention has good contrast, high response speed, high reliability and good low-temperature storage stability. ##STR00001##