The present invention provides a compound represented by General Formula (I). The compound according to the present invention prevents the liquid crystal composition from being deteriorated due to light, has high compatibility with the liquid crystal composition, and does not impair the storage stability of the liquid crystal composition, thus the compound is useful as a constituent member of a liquid crystal composition. Since the liquid crystal composition and the liquid crystal display element containing the compound of the present invention exhibit UV resistance and have a high VHR, it is possible to obtain a liquid crystal display element with excellent display quality in which display defects such as burn-in and display unevenness do not occur or are suppressed.

##STR00001##

Compounds of formula I, and liquid-crystalline media, preferably having a nematic phase and negative dielectric anisotropy, comprising: a) one or more compounds of formula I

##STR00001## and one or more other compounds selected from: b) one or more compounds of formula II

##STR00002## and/or c) one or more compounds selected from compounds of formulae III-1 to III-4 and B

##STR00003##

Use thereof in electro-optical displays, particularly in active-matrix displays based on the VA, ECB, PALC, FFS or IPS effect and use of compounds of formula I for stabilisation of liquid-crystalline media which comprise one or more compounds of formula II and/or one or more compounds selected from compounds of formulae III-1 to III-4 and B.

Compounds of the formula I, and liquid-crystalline media, preferably having a nematic phase and negative dielectric anisotropy, comprising a) one or more compounds of the formula I

##STR00001## and one or more compounds selected from b) one or more compounds of formula II

##STR00002## and/or c) one or more compounds selected from compounds of formulae III-1 to III-4 and formula B

##STR00003##

Methods for making and using these liquid-crystalline media in electro-optical displays, particularly in active-matrix displays based on the VA, ECB, PALC, FFS or IPS effect and the displays which contain these media. Methods for stabilizing liquid-crystalline media with compounds of formula I, where the liquid-crystalline media comprise one or more compounds of the formula II and one or more compounds selected from compounds of the formulae III-1 to III-4 and formula B.

A curved liquid crystal display comprises, a first curved substrate; a second curved substrate facing the first curved substrate; a liquid crystal layer disposed between the first curved substrate and the second curved substrate; a first curved liquid crystal alignment layer disposed between the liquid crystal layer and the first curved substrate and containing a light stabilizer; and a second curved liquid crystal alignment layer disposed between the liquid crystal layer and the second curved substrate.

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 present invention is to provide a polymerizable liquid crystal compound represented by Formula (I);

Q.sup.1-Sp.sup.1A-L.sub.m-1A-Sp.sup.2-Q.sup.2(I)

A represents a divalent nitrogen-containing saturated cyclic group (that may have a substituent) formed by removing two hydrogen atoms from piperidine or piperazine, a phenylene group that may have a substituent, or a trans-1,4-cyclohexylene group that may have a substituent, L represents C(O)O, OC(O), or the like, m represents 3 to 12, Sp.sup.1 and Sp.sup.2 represent an alkylene group having 1 to 20 carbon atoms, any one of Q.sup.1 and Q.sup.2 represents a polymerizable group, Formula (I) has a nitrogen-containing saturated cyclic group and a phenylene group that are directly bonded to each other via C(O)O. By using a polymerizable composition including the polymerizable liquid crystal compound, a film such as a retardation film having low birefringence or a reflection film having high selectivity in a reflection wavelength range can be provided.

The present invention relates to dielectrically positive liquid-crystalline media comprising one or more compounds of the formula I and/or TINUVIN 770,

##STR00001##

in which the parameters have the respective meanings indicated in the specification, and optionally one or more further dielectrically positive compounds and optionally one or more further dielectrically neutral compounds, and to liquid-crystal displays, especially active-matrix displays and in particular TN, IPS and FFS displays, containing these media.

The invention relates to compounds of the formula I, and to 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 formula II

##STR00002##

in which the parameters have the respective meanings indicated in Claim 1, to the use thereof in an electro-optical display, particularly in an active-matrix display based on the VA, ECB, PALC, FFS or IPS effect,

The liquid crystal composition contains a compound contributing to high stability to heat or ultraviolet light, has negative dielectric anisotropy and has a nematic phase, and may contain a specific compound having high negative dielectric anisotropy as a first component, a specific compound having a high maximum temperature or small viscosity as a second component, and a specific compound having a polymerizable group.

The present invention relates to liquid-crystalline media (LC media), characterised in that they comprise one or more compounds of the formula I,

##STR00001## and one or more compounds of the formula II,

##STR00002## where the parameters have the meaning indicated in claim 1, to the use thereof in electro-optical displays, and to LC displays which contain these LC media.