Liquid-crystalline media containing one or more compounds of formula T ##STR00001##
and one or more compounds of formulae I, II and/or III, ##STR00002##
high-frequency components containing 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 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 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 a liquid-crystal medium which comprises one or more compounds each of formulae I and II

##STR00001##

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.

The present invention relates to light-scattering liquid crystal devices suited for use in light control glass such as optical shutters and use in segment displays in, for example, clocks. A light-scattering liquid crystal device according to the present invention includes two substrates 1, of which at least one includes an electrode layer 2 and at least one is transparent, and a light control layer 4 held between the substrates, the light control layer 4 containing a liquid crystal material and a polymer substance, wherein the light-scattering liquid crystal device includes, between the substrates and the light control layer, a thin film layer 3 formed by subjecting a thermally curable compound containing a reactive group to thermal curing. According to the present invention, a light-scattering liquid crystal device having dramatically improved adhesion can be provided.

Described herein are liquid crystal compositions that can allow for the adjustment of their refractive indices by the application of an electric field. Also described herein are liquid crystal mixtures containing these compositions. In addition, selectively dimmable reverse-mode polymer dispersed liquid crystal (PDLC) elements and devices using these compositions are also described, which are transparent when no or low voltage is applied and opaque when a voltage or high voltage is applied.

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-crystalline media comprising one or more compounds selected from the group of compounds of formula I

##STR00001##

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 present invention relates to isothiocyanato tolane derivatives of formula I

##STR00001##

in which the occurring groups have the meanings indicated in claim 1, to a process for their preparation, to liquid-crystalline media comprising same and to high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, in particular for microwave phased-array antennas.