The compounds of the formula I, and a liquid-crystalline medium, preferably having a nematic phase and negative dielectric anisotropy, which comprises a) one or more compounds of the formula I ##STR00001## and b) one or more compounds of the formulae II-1 to II-4, ##STR00002##
in which the parameters have the meanings defined herein, are suitable for use in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect.

There is provided a liquid crystal composition that exhibits a sufficiently low viscosity (η), a sufficiently low rotational viscosity (γ1), and a large elastic modulus (K.sub.33) without decreasing the refractive index anisotropy (Δn) 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.

There is provided a liquid crystal composition that exhibits a sufficiently low viscosity (η), a sufficiently low rotational viscosity (γ1), and a large elastic modulus (K.sub.33) without decreasing the refractive index anisotropy (Δn) 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.

The present invention belongs to the technical field of liquid crystal materials, and in particular relates to a negative liquid crystal composition and a liquid crystal display element or liquid crystal display containing the liquid crystal composition. The present invention discloses a negative dielectric nematic liquid crystal composition, comprising a compound represented by Formula I, one or more compounds represented by Formula II, and one or more compounds represented by Formula III. The liquid crystal composition has a relatively low rotational viscosity (γ.sub.1), a high clearing point (Cp), a good solubility and a high stability to heat and light (VHR) on the basis of maintaining an appropriate optical anisotropy (Δn), and can be used for developing a liquid crystal display element or liquid crystal display with a low cell thickness, a wide temperature for display, and a fast response.

##STR00001##

The present invention belongs to the technical field of liquid crystal materials, and in particular relates to a negative liquid crystal composition and a liquid crystal display element or liquid crystal display containing the liquid crystal composition. The present invention discloses a negative dielectric nematic liquid crystal composition, comprising a compound represented by Formula I, one or more compounds represented by Formula II, and one or more compounds represented by Formula III. The liquid crystal composition has a relatively low rotational viscosity (γ.sub.1), a high clearing point (Cp), a good solubility and a high stability to heat and light (VHR) on the basis of maintaining an appropriate optical anisotropy (Δn), and can be used for developing a liquid crystal display element or liquid crystal display with a low cell thickness, a wide temperature for display, and a fast response.

##STR00001##

A liquid crystal composition containing a benzochromene compound and the use thereof in a liquid crystal display element or liquid crystal display. The liquid crystal composition comprises one or more compounds represented by Formula I and one or more compounds represented by Formula II. The liquid crystal composition has the characteristics of a small rotational viscosity, a large elastic constant, a high transmittance, a fast response speed, a strong resistance to ultraviolet light irradiation, and a high long-time light stability, and is particularly suitable for the field of TV display.

##STR00001##

A liquid crystal composition containing a benzochromene compound and the use thereof in a liquid crystal display element or liquid crystal display. The liquid crystal composition comprises one or more compounds represented by Formula I and one or more compounds represented by Formula II. The liquid crystal composition has the characteristics of a small rotational viscosity, a large elastic constant, a high transmittance, a fast response speed, a strong resistance to ultraviolet light irradiation, and a high long-time light stability, and is particularly suitable for the field of TV display.

##STR00001##

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.

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.

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.