To show a liquid crystal composition containing a polymerizable compound, to exhibit excellent persistence characteristics and display unevenness characteristics, a liquid crystal display device including such a composition, and an optical device. To show a liquid crystal composition containing the polymerizable compound and satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy and large specific resistance; and an AM device having characteristics such as a small persistence ratio, a short response time, a low threshold voltage, a large voltage holding ratio, a large contrast ratio and a long service life. The liquid crystal composition contains as a first component a polymerizable monomer that has a capability of a hydrogen bond donor and can form a hydrogen bond with an alignment film surface, or an oligomer, a prepolymer or a polymer of the monomer.

The present invention relates to liquid crystalline media comprising one or more naphthothiadiazol derivatives of formula I,

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in which R.sup.11, R.sup.12, A.sup.11, A.sup.12, A.sup.21, A.sup.22, Z.sup.11, Z.sup.12, Z.sup.21, Z.sup.22, W, X.sup.11, X.sup.12, L, r, s and t have the meanings indicated in claim 1, to the use of such liquid crystal media for optical, electro-optical and electronic purposes, in particular in devices for regulating the passage of energy from an outside space into an inside space, for example in windows.

A liquid crystal composite according to the technology described herein includes liquid crystal molecules showing liquid crystal properties, a polymerizable monomer polymerized by an external stimulus, the polymerizable monomer having substantially no optical activity, and a chiral compound that is racemized by an external stimulus, the chiral compound having an optical activity.

The present invention relates to a nematic liquid crystal composition containing a polymerizable compound and having a negative dielectric anisotropy () and PSA or PSVA liquid crystal display element produced by using the same. The liquid crystal composition according to the present invention can provide PSA or PSVA liquid crystal display element, in which a sufficient pretilt angle is included, the amount of remaining monomer is small, there are no or almost no problems, e.g., alignment defects and display defects, arisen from a low voltage holding rate (VHR) and the like, and excellent response performance is exhibited. A liquid crystal display element using the liquid crystal composition according to the present invention is useful for an active-matrix-drive liquid crystal display element and can be applied to PSA, PSVA, and other liquid crystal display elements.

Disclosed are liquid crystal compounds of cycloalkyl-containing dibenzofuran derivatives, a preparation method therefor and use thereof. The compounds are as represented by formula I. In the molecular structures of the compounds of formula I provided by the present invention, liquid crystal compounds of cycloalkyl terminal group-containing dibenzofuran derivatives, compared with those having flexible alkyl chains as terminal groups, exhibit better intersolubility, and thus the use of a compound as represented by formula I provided by the present invention can improve the intersolubility of a liquid crystal compound and extend the application range of a liquid crystal mixture, producing an important application value. ##STR00001##

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 (.sub.1); and 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).

The present invention relates to an LC medium comprising and a liquid-crystalline host consisting of an LC component H) comprising one or more mesogenic or liquid-crystalline compounds and an optically active component D) and optionally a polymerizable component P) comprising one or more polymerizable compounds; and to the use of the polymerizable compounds and LC media for optical, electro-optical and electronic purposes, in particular in LC displays, especially in LC displays of the polymer sustained alignment type.

There is provided a liquid crystal composition that exhibits a sufficiently low viscosity (), a sufficiently low rotational viscosity (1), and a large elastic modulus (K.sub.33) without decreasing the refractive index anisotropy (n) and the nematic phase-isotropic liquid phase transition temperature (T.sub.ni) and without increasing the solid phase-nematic phase transition temperature (T.sub.cn). The liquid crystal display element that uses this liquid crystal composition satisfactorily obtains a pretilt angle and has a high voltage holding ratio (VHR) and high-speed response. Thus, a liquid crystal display element that has no or less alignment defects and display defects such as image sticking, and has high display quality and high response speed is obtained.

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 () at 25 C. is 2.0 or less. Also, a liquid crystal display device having high contrast, fast response, and excellent display quality without causing image sticking and display defects.

Provide is a polar compound having high chemical stability, high capability of aligning liquid crystal molecules, high solubility in a liquid crystal composition, and a large voltage holding ratio when the compound is used in a liquid crystal display device. The problem is solved by a compound represented by formula (1).

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For example, R.sup.1 is alkyl having 1 to 15 carbons; rings A.sup.1 to A.sup.5 are cyclohexylene or phenylene; Z.sup.1, Z.sup.4 and Z.sup.5 are a single bond or alkylene having 1 to 10 carbons; a, b and c are 0 to 4; d and e are 1 to 4; P.sup.2 and P.sup.3 are a polymerizable group; and Sp.sup.2 and Sp.sup.3 are a single bond or alkylene having 1 to 10 carbons.