The present invention pertains to: a liquid crystal composition for controlling light that contains, as a dichroic dye, an anthraquinone compound having a specific structure; and a light-controlling element that contains a cured product of said liquid crystal composition for controlling light and exhibits excellent contrast, light-blocking performance, lightfastness, and heat tolerance during current supply. More specifically, the present invention pertains to: a liquid crystal composition for controlling light that contains a compound represented by formula (A) (in the formula. R1 represents a C1-12 alkyl group or a C1-12 alkoxy group, and each R2 independently represents a C1-8 alkyl group), a liquid crystal material, a photocurable compound, and a photoinitiator; and a light-controlling element that is formed by sandwiching a photocured product of said composition between a pair of substrates.

##STR00001##

The present invention is a liquid crystal composition having negative dielectric anisotropy containing one or two or more of compounds represented by General Formula (i), and is also a liquid crystal display element using the liquid crystal composition. The problem to be solved by the present invention is to provide a liquid crystal composition with a large refractive index anisotropy (n), a low rotational viscosity (.sub.1), a large elastic constant (K.sub.33), a high voltage holding ratio (VHR), and which has a negative dielectric anisotropy (), and a liquid crystal display element which, when using the liquid crystal composition, has a high response speed with excellent display quality in which display defects such as drop marks, burn-in, and display unevenness are absent or suppressed.

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.

It is an object of the present invention to provide a compound that can provide a liquid crystal composition with a high T.sub.ni, a high ?n, a low V.sub.th, a high ??.sub.r, a low tan ?.sub.iso, and high storage stability at low temperatures, a liquid crystal composition, as well as a liquid crystal display element, a sensor, a liquid crystal lens, optical communication equipment, and an antenna each using this. Specifically disclosed are a compound represented by the general formula (i) having an ethynylene group (C?C) and an isothiocyanate group (NCS) and a liquid crystal composition containing one or two or more of the compounds.

The present application relates to mixtures which have liquid-crystalline properties. The application furthermore relates to the use of the mixtures in devices which regulate the transmission of light through an area element.

An object of the present invention is to provide a composition that realizes high n, has a wide liquid crystal phase temperature range, small viscosity, excellent low-temperature solubility, and high resistivity and voltage holding ratio, and is stable against heat and light, and to provide a liquid crystal composition having an excellent lens effect and excellent chemical stability using the composition, and a liquid crystal display device and a liquid crystal lens that use the liquid crystal composition. The present invention provides a liquid crystal composition that contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii), a liquid crystal display device using the liquid crystal composition, a liquid crystal lens using the liquid crystal composition, and a birefringence lens for stereoscopic image display using the liquid crystal composition.

To provide a liquid crystal compound satisfying at least one of high stability to heat, light and so forth, a high clearing point, low minimum temperature of a liquid-crystal phase, small viscosity, suitable optical anisotropy, large dielectric anisotropy, a suitable elastic constant and excellent compatibility with other liquid-crystal compounds, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. A compound is represented by formula (1-1). ##STR00001##
For example, R.sup.1 and R.sup.2 are independently hydrogen, alkyl having 1 to 10 carbons, alkenyl having 3 to 10 carbons and alkoxy having 1 to 9 carbons; ring A.sup.1 is 1,4-cyclohexylene; ring A.sup.2 and ring A.sup.3 are independently 1,4-cyclohexylene or 1,4-phenylene; Z.sup.1 is a single bond or (CH.sub.2).sub.2; l is 0 or 1, m and n are 0, 1 or 2, a sum: l+m+n is 0, 1 or 2; x is 0 or 1.

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.

The composite liquid crystal composition contains a liquid crystal compound and a polymerizable compound. The liquid crystal compound includes a compound having a biphenyl skeleton including two or three rings, and two or more compounds other than the compound having the biphenyl skeleton. The composition includes polymerizable compound. The ratio of the content (mass) of the one or more compounds selected from the compounds represented by General Formulas (II-a1) and (II-a2) to the compound represented by General Formula (II-b) is 70:30 to 30:70. The total content of the liquid crystal compounds is 65% to 85% by mass, and the total content of the polymerizable compounds is 15% to 35% by mass.

The present invention pertains to: a liquid crystal composition for controlling light that contains, as a dichroic dye, an anthraquinone compound having a specific structure; and a light-controlling element that contains a cured product of said liquid crystal composition for controlling light and exhibits excellent contrast, light-blocking performance, lightfastness, and heat tolerance during current supply. More specifically, the present invention pertains to: a liquid crystal composition for controlling light that contains a compound represented by formula (A) (in the formula. R1 represents a C1-12 alkyl group or a C1-12 alkoxy group, and each R2 independently represents a C1-8 alkyl group), a liquid crystal material, a photocurable compound, and a photoinitiator; and a light-controlling element that is formed by sandwiching a photocured product of said composition between a pair of substrates. ##STR00001##