The present invention relates to liquid crystalline (LC) medium, to a method of its production and to the use of such LC media in polymer network liquid crystalline (PNLC) light modulation elements operated in the normally transparent mode. Furthermore, the present invention relates to such light modulation elements, as such, to the use of such light modulation elements as light shutters for transparent OLED displays, to the use of such light modulation elements in smart windows, and to a method of production of such light modulation elements according to the present invention.

To show a liquid crystal composition having at least one or a suitable balance regarding at least two of characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio, a long service life and a small flicker rate; and an AM device having characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life. The liquid crystal composition has a negative dielectric anisotropy and contains a specific compound having a large negative dielectric anisotropy as a first component, and the composition may contain a specific compound having a high maximum temperature or a small viscosity as a second component, a specific compound having a large negative dielectric anisotropy as a third component, and a specific compound having a polymerizable group as an additive component.

A liquid crystal composition containing a polymerizable compound of the present invention has excellent characteristics of being able to prepare a PSA type liquid crystal display element with no problem of depositing in a wide temperature range, having high polymerization speed, high liquid crystal alignment regulation force after polymerization, excellent display qualities with no display unevenness, and excellent display characteristics with no defects in display characteristics such as image sticking and is appropriate as a liquid crystal composition in a practical use. Further, the liquid crystal display element with the above-described liquid crystal composition can be appropriately used for a PSA type liquid crystal display element.

A liquid crystal composition satisfying at least one characteristic such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to UV light or to heat, or having a suitable balance regarding at least two of the characteristics, and an AM device having characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio and a long service life are shown. The liquid crystal composition contains a specific compound having at least three polymerizable groups, and the liquid crystal display device includes the composition. The composition may contain a specific compound having large negative dielectric anisotropy as a first component, and a specific compound having a high maximum temperature or small viscosity as a second component.

A liquid crystal composition satisfying at least one of characteristics such as high maximum temperature of a nematic phase, low minimum temperature thereof, small viscosity, suitable optical anisotropy, large negative dielectric anisotropy, large specific resistance, high stability to ultraviolet light and high stability to heat, or having a suitable balance regarding at least two of the characteristics; and an AM device having characteristics such as short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio and a long service life. The liquid crystal composition contains a compound that can contribute to high stability to heat or ultraviolet light, and has negative dielectric anisotropy and the nematic phase.

Provided are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy and large negative dielectric anisotropy, or the liquid crystal composition having a suitable balance regarding at least two of the characteristics; and an AM device including the composition. The liquid crystal composition may contain a specific compound having small viscosity or low minimum temperature as a first component, a specific compound having negative dielectric anisotropy, small viscosity and low threshold voltage as a second component, a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having negative dielectric anisotropy or low minimum temperature as a fourth component, or a specific compound having a polymerizable group as an additive component.

Shown are a liquid crystal composition satisfying at least one of characteristics such as high maximum temperature, low minimum temperature, small viscosity, suitable optical anisotropy and large dielectric anisotropy, or having a suitable balance regarding at least two of the characteristics; and an AM device including the composition. The liquid crystal composition contains a specific compound having large positive dielectric anisotropy as a first component and a specific compound having small viscosity as a second component, and the composition may contain a specific compound having high maximum temperature or small viscosity as a third component, a specific compound having positive dielectric anisotropy as a fourth component, or a specific compound having negative dielectric anisotropy as a fifth component.

The invention relates to a liquid-crystalline medium which comprises one or more compounds of the formula BO

##STR00001##

in which the parameters have the meanings indicated in Claim 1, to the use of the liquid-crystalline medium for electro-optical purposes, in particular in liquid-crystal light valves for lighting devices for motor vehicles, and to liquid-crystal light valves which comprise this medium and lighting devices for motor vehicles which contain such liquid-crystal light valves and to compounds of the formula BO.

The subject is to shown a liquid crystal display device that has characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large contrast ratio, a long service life and a small flicker rate. The disclosure relates to a liquid crystal display device having an electrode group formed on one or both of a pair of substrates that are opposed to each other, and a plurality of active devices connected to the electrode group, and a liquid crystal alignment film formed on the opposing surfaces of the pair of substrates, and a liquid crystal composition sandwiched in between the pair of substrates, wherein the liquid crystal alignment film includes a polymer having a photodegradable group, and the liquid crystal composition includes at least one compound selected from the group consisting of compounds represented by formula (1) as a first component: ##STR00001##

Provided are a liquid crystal composition in which vertical alignment of liquid crystal molecules can be achieved by action of a polymer, and a liquid crystal display device including the composition. The composition is a nematic liquid crystal composition that has negative dielectric anisotropy and contains a specific liquid crystal compound having large negative dielectric anisotropy as a first component and a polar compound having a polymerizable group as a first additive, and may contain a specific liquid crystal compound having high maximum temperature or small viscosity as a second component, a specific liquid crystal compound having large negative dielectric anisotropy as a third component, and a polymerizable compound as a second additive, and the liquid crystal display device includes the composition.