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.

The present invention relates to a compound of formula UI

##STR00001##

as defined in claim 1, to a liquid crystal medium comprising a compound of formula UI 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 and a display device are provided. The liquid crystal composition includes a compound having a structure represented by general formula (I) and a compound having a structure represented by general formula (II),

##STR00001##

and L.sub.11, L.sub.2, L.sub.3 and L.sub.4 are independently selected from

##STR00002##

Z.sub.1 is selected from a single bond or —C≡C—; R.sub.1, R.sub.2 and R.sub.3 are independently selected from alkyl, alkenyl, alkynyl, haloalkyl or OR.sub.4; and R.sub.4 is selected from alkyl, alkenyl, alkynyl or haloalkyl.

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.

An object of the present invention is to provide a polymerizable liquid crystal composition used for formation of an optically anisotropic film having excellent moisture-heat resistance and an excellent surface condition, an optically anisotropic film, an optical film, a polarizing plate, and an image display device. The polymerizable liquid crystal composition of an embodiment of the present invention is a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound and a compound represented by Formula (1): L.sup.1-SP.sup.1-(E.sup.3-A.sup.1).sub.m-E.sup.1-G.sup.1-C(═O)—O—C(═O)-G.sup.2-E.sup.2-(A.sup.2-E.sup.4).sub.n-SP.sup.2-L.sup.2, in which a content of the compound represented by Formula (1) is 0.01 to 5 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound.

A composition having a high n, a wide temperature range of a liquid crystal phase, low viscosity, good solubility at a low temperature, high resistivity, a high voltage holding ratio, and stability against heat and light; a liquid crystal composition containing the composition, the liquid crystal composition having a good lens effect and good chemical stability; a liquid crystal display device including the liquid crystal composition; and a liquid crystal lens including the liquid crystal composition. The liquid crystal composition contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii).

An object of the present invention is to provide a composition that realizes high n, has a wide liquid crystal phase temperature range, small viscosity, excellent low-temperature solubility, and high resistivity and voltage holding ratio, and is stable against heat and light, and to provide a liquid crystal composition having an excellent lens effect and excellent chemical stability using the composition, and a liquid crystal display device and a liquid crystal lens that use the liquid crystal composition. The present invention provides a liquid crystal composition that contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii), a liquid crystal display device using the liquid crystal composition, a liquid crystal lens using the liquid crystal composition, and a birefringence lens for stereoscopic image display using the liquid crystal composition.

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.

Disclosed is a liquid crystal composition comprising one or more compounds represented by formula I and/or formula II and one or more compounds represented by formula III: ##STR00001##
wherein the definition of each substituent is given. The composition involved in the present invention has a low viscosity .sub.1, a high clearing point Tni and a large optical anisotropy n, and can realize a rapid response of liquid crystal display.