Disclosed are a liquid crystal composition and a liquid crystal display device. The liquid crystal composition comprises at least one compound of general formula I, at least one compound of general formula II, at least one compound of general formula III, and at least one compound of general formula IV. By compounding the four compounds, the composition can have advantages of a wide temperature range of nematic phase, a low viscosity and a low threshold voltage, and the liquid crystal display element can have a short response time and great power saving performance.

A polymerizable LC material comprising one or more reactive mesogenic compounds, one or more chiral compounds and a block copolymer that comprises at least one polyfluorooxetane block bonded to a polyether block, said polyfluorooxetane block having a repeating unit of the formula

##STR00001##

Further, a method for its preparation, a polymer film obtainable from a corresponding polymerizable LC material, a method of preparation of such polymer film, and the use of such polymer film and said polymerizable LC material in optical, electro-optical, decorative or security devices.

A double layer liquid crystal device comprises a first and a second layer with orthogonal or crossed alignment of the liquid crystal phase of the two layers, in which the first and second layer have first and second alignment aids comprised of a polymerized or polymerizable molecular compound. The layers are aligned by UV photoalignment and vertical self-alignment by the aid of suitable additives.

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.1, 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 liquid-crystal (LC) media having negative dielectric anisotropy comprising one or more compounds of formula I

##STR00001##

and one, two, three or more compounds of formula III

##STR00002##

as defined in claim 1, and to the use of the LC media for optical, electro-optical and electronic purposes, in particular useful to enable energy-saving LC displays of the VA, IPS or FFS type.

To suppress a phenomenon where an optical axis of the optically anisotropic layer is tilted when the optically anisotropic layer is produced by using a liquid crystalline compound showing smectic phase as a materials showing a higher level of orderliness. An optically anisotropic layer wherein a polymerizable composition, containing one or more polymerizable rod-like liquid crystal compound showing a smectic phase, is fixed in a state of smectic phase, and a direction of maximum refractive index of the optically anisotropic layer is inclined at 10° or smaller to the surface of the optically anisotropic layer, a method for manufacturing the same, a laminate and a method for manufacturing the same, a polarizing plate, a liquid crystal display device, and an organic EL display device.

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 invention relates to a polymerisable LC material comprising at least one di- or multireactive mesogenic compound and at least one compound of formula I,

##STR00001##

in which the parameter R.sup.1, A.sup.1, Z.sup.1, Z.sup.2, n, Sp, P, p1, p2, L.sup.1, L.sup.2, r1, r2, m and R.sup.2 have one of the meanings as given in claim 1. Furthermore, the present invention relates also to a method for the preparation of a polymerisable LC material, a polymer film obtainable from the corresponding polymerisable LC material, to a method of preparation of such polymer film, and to the use of such polymer film and said polymerisable LC material for optical, electro-optical, decorative or security devices.

Provided is a compound which is capable of reducing a tilt angle of a liquid crystal molecule, and a polymerizable composition, a cured product, an optical film, a polarizing plate, and an image display device, each using the compound. The compound is represented, for example, by Formula (I), P-Sp-Z-G.sup.1-(X.sup.1-Cy.sup.1)n-(X.sup.2-A.sup.1)m-X.sup.3-A.sup.2.