Compounds containing at least one C—C triple bond within a chain of at least 3 ring systems which have positive dielectric anisotropy, the use thereof for high-frequency components, liquid-crystalline media containing these compounds, and high-frequency components, in particular antennae, especially for the gigahertz region, containing these media. The liquid-crystalline media serve, for example, for the phase shifting of microwaves for tuneable phased-array antennae.

The present invention provides a liquid crystal composition having negative dielectric anisotropy, large refractive index anisotropy, and low viscosity and containing as a first component, one or two or more compounds represented by general formula (I) and, as a second component, one or two or more compounds represented by general formula (II), wherein dielectric anisotropy (Δ∈) at 25° C. is −2.0 or less. Also, provided is a liquid crystal display device having high contrast, fast response, and excellent display quality without causing image sticking and display defects.

There is provided a polymerizable compound-containing liquid crystal composition having strong alignment regulating force of a liquid crystal compound. The polymerizable compound-containing liquid crystal composition includes: a polymerizable compound; and a liquid crystal compound, in which the polymerizable compound includes at least one polymerizable compound represented by General Formula (I), and in which the liquid crystal compound includes at least one component selected from the group consisting of at least one compound represented by General Formula (II) as a second component, at least one compound represented by General Formulae (IIIa), (IIIb), and (IIIc) as a third component, and at least one compound represented by General Formulae (IVa), (IVb), and (IVc) as a fourth component.

There is provided a liquid crystal composition containing at least one compound represented by General Formula (a). There is also provided a liquid crystal display device using such a liquid crystal composition. The liquid crystal composition of the present invention has the following properties without suffering reductions in refractive index anisotropy (Δn) and nematic phase-isotropic liquid phase transition temperature (T.sub.ni): sufficiently low viscosity (η), sufficiently low rotational viscosity (γ.sub.1), a large elastic constant (K.sub.33), a high voltage holding ratio after UV exposure (VHR (UV)), and a negative dielectric anisotropy (Δ∈) with a large absolute value. A liquid crystal display device of, for example, a VA type that uses such a liquid crystal composition has a high response speed and excellent display quality with defective display being eliminated or reduced.

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The present invention provides a liquid crystal composition including at least one compound represented by General Formula (1), at least one compound represented by General Formula (2), and at least one compound represented by General Formula (LC1).

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The liquid crystal composition of the present invention has high refractive index anisotropy (Δn) and sufficiently low viscosity (η), achieves a wide nematic phase temperature range by suppressing a decrease in nematic phase-isotropic liquid phase transition temperature (T.sub.ni), and exhibits high compatibility. By using the liquid crystal composition of the present invention in a liquid crystal display element, a liquid crystal display element having a high response speed and high practical reliability can be obtained.

An optical film, a polarizing plate, and an image display device, each having an optically anisotropic layer obtained by curing a polymerizable liquid crystal composition including a polymerizable liquid crystal compound (LCC) having forward wavelength dispersion and a monofunctional compound, and immobilizing an alignment state of the polymerizable LCC. The number a.sub.1 of atoms of the polymerizable LCC and the number a.sub.2 of atoms of the monofunctional compound satisfy a relationship of Expression (1): 0.2<a.sub.2/a.sub.1<0.55; the number b.sub.1 of the rings B.sup.1 contained in the polymerizable LCC and the total number b.sub.2 of the aromatic rings Ar and the rings B.sup.2 contained in the monofunctional compound satisfy a relationship of Expression (2): b.sub.2=b.sub.1×0.5 or b.sub.2=(b.sub.1+1)×0.5.

There is provided a liquid crystal display device which enables reductions in image sticking and droplet stains caused in production thereof without degradation of properties such as dielectric anisotropy, viscosity, the upper limit of the temperature of nematic phase, and rotational viscosity (γ.sub.1); and there is also provided a method for manufacturing such a liquid crystal display device. The liquid crystal display device is characterized in that a liquid crystal layer containing a liquid crystal composition is disposed between a substrate provided with a common electrode and a color filter layer and another substrate provided with a plurality of pixels each having a pixel electrode, each of the substrates is not provided with an alignment film but provided with an orientation controlling layer composed of at least two polymerizable compounds, each of the pixels has two or more regions having different directions of pretilt, and the liquid crystal composition contains a compound represented by General Formula (I) and a compound represented by General Formula (II).

A liquid-crystal medium containing a component A of one or more compounds of formula X ##STR00001##
the preparation thereof, and the use of these liquid-crystal media, in particular in components for high-frequency technology, and components of this type which contain the media, and the production and use of these components. The components are suitable for phase shifters in the microwave and millimeter wave region, for microwave and millimeter wave array antennae and for tuneable reflectarrays.

Reactive mesogens (RMs), mixtures and formulations comprising RMs, polymers obtained from such RMs and RM mixtures, and the use of the RMs, RM mixtures and polymers in optical or electrooptical components or devices, like optical films for liquid crystal displays (LCDs).

Provided is an optically anisotropic layer having an excellent surface condition, with which an image display device having an excellent contrast can be manufactured; and an optical film, a polarizing plate, and an image display device, each having the optically anisotropic layer. The optically anisotropic layer is obtained by immobilizing a polymerizable liquid crystal composition including a polymerizable rod-shaped liquid crystal compound exhibiting a liquid crystal state of a smectic phase and an additive in a liquid crystal state of a smectic phase, in which a molecular length A (Å) of the polymerizable rod-shaped liquid crystal compound, a layer interval B (Å) of the smectic phase of the optically anisotropic layer, and a molecular length C (Å) of the additive satisfy a relationship of Expression (1-1), 0.5×B≤C≤0.6×A . . . (1-1).