The present invention relates to heteroaromatic isothiocyanates of formula N

##STR00001##

as defined in claim 1, to liquid-crystalline media comprising one or more compounds of formula N 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 a compound of formula G

##STR00001##

as defined in claim 1, to a liquid crystal medium comprising a compound of formula G 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 compound having large refractive index anisotropy (?n), the effect of increasing the phase transition temperature of a liquid crystal phase, and high solubility, and showing large dielectric anisotropy (??) in a high frequency region, a composition containing the compound, a liquid crystal composition, and a device using the liquid crystal composition. The compound has large refractive index anisotropy ?n, sufficiently high T.sub.n-i, and high compatibility with a liquid crystal composition, and shows large dielectric anisotropy in a high frequency region, and is thus useful for a material of an element of a device such as a high-frequency phase shifter, a phased array antenna, an image recognition device, a distance measuring device, a liquid crystal display device, a liquid crystal lens, a birefringent lens for stereoscopic image display.

Shown is a method for producing a liquid crystal capsule having a particle diameter of 30 to 150 nanometers, and a method for producing a liquid crystal capsule without using a homogenizer. The disclosure concerns a method for producing a liquid crystal capsule, including a step of preparing an emulsion by performing phase inversion emulsification of a mixed material obtained by mixing a liquid crystal composition, a monomer, a surfactant, and a polymerization initiator; and a step of producing a liquid crystal capsule by applying a coacervation method to the emulsion. The disclosure also concerns a liquid crystal capsule having a liquid crystal composition, a surfactant and a capsule wall, wherein the capsule wall has a closed curved shape, the liquid crystal composition and a hydrophobic moiety of the surfactant are arranged inside the capsule wall, and a hydrophilic moiety of the surfactant is arranged outside the capsule wall.

The present invention relates to a switching layer based on a liquid-crystalline mixture for use in an optical switching element. The invention also encompasses a switching element comprising the switching layer and a window element containing the switching element. The liquid crystalline mixture comprises a low-molecular liquid crystal component, a polymer component and a self-alignment additive for vertical alignment.

The disclosure is a liquid crystal compound represented by Formula (I),

##STR00001## wherein R.sup.1, R.sup.2, R.sup.3, ring A.sup.1, ring A.sup.2, ring A.sup.3, Z.sup.1, Z.sup.2, and n have definitions that are described in details herein. The liquid crystal compound represented by Formula (I) can be used to prepare a liquid crystal composition that has superior low-temperature storage.

A liquid crystal composition that satisfies a plurality of characteristics in characteristics such as a high maximum temperature of a nematic phase, a low minimum temperature of the nematic phase, small viscosity, large optical anisotropy, large dielectric anisotropy (1 kHz and 20 GHz), large specific resistance, high stability to ultraviolet light and high stability to heat, and that can be used in the form of a millimeter wave phase or microwave phase antenna.

The liquid crystal composition contains at least two specific compounds having the large optical anisotropy and the large dielectric anisotropy as a first component, and a specific compound having a wide nematic phase and capable of adjusting suitable optical anisotropy as a second component, and may contain such a component compound that can finely control the characteristics of the composition.

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.

According to one embodiment, a liquid crystal optical element includes a transparent substrate including a main surface, an alignment film disposed on the main surface, and a liquid crystal layer overlapping the alignment film and including a cholesteric liquid crystal including liquid crystal molecules stacked helically and an additive exhibiting a liquid crystalline property. In the liquid crystal layer, a reflective surface along which alignment directions of the liquid crystal molecules are identical is inclined with respect to the main surface.

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