The present invention relates to liquid-crystalline media comprising a) one or more compounds of the formula ST-1, as defined herein, and b) one or more compounds of the formula ST-2, as defined herein, and c) one or more compounds of the formula RV, as defined herein, and d) one or more compounds selected from formula IA and IB, as defined herein, and to liquid-crystal displays containing these media, especially to displays addressed by an active matrix and in particular to displays of the in-plane switching (IPS) or fringe-field switching (FFS) type.

The spontaneous orientation aid for a liquid crystal composition provides storage stability and allows liquid crystal molecules to be vertically aligned without a PI layer when added to a liquid crystal composition. When used in a liquid crystal composition, the spontaneous orientation aid can adsorb to substrates sandwiching a liquid crystal composition (liquid crystal layer) and keep the liquid crystal molecules aligned in a vertical direction. The spontaneous orientation aid makes it possible to align liquid crystal molecules without a PI layer (to induce vertical alignment of liquid crystal molecules under no applied voltage and to achieve horizontal alignment of the liquid crystal molecules under an applied voltage).

The invention relates to a compound of formula I,

##STR00001##

wherein R.sup.11, R.sup.21, A.sup.11, A, Z, X.sup.11, X.sup.21, Y.sup.11, Y.sup.12, Sp.sup.11, Sp.sup.21, o and p have one of the meanings as given in claim 1. The invention further relates to method of production of a compound of formula I, to the use of said compounds in LC media and to LC media comprising one or more compounds of formula I. Further, the invention relates to a method of production of such LC media, to the use of such media in LC devices, and to LC device comprising a LC medium according to the present invention. The present invention further relates to a process for the fabrication such liquid crystal display and to the use of the liquid crystal mixtures according to the invention for the fabrication of such liquid crystal display.

The purpose of the invention is to control, by using a colorless alignment control monomer, the alignment of liquid crystal molecules of a liquid crystal display element that does not include an alignment film, and to provide a liquid crystal composition with which the colorless alignment control monomer exhibits excellent compatibility. The invention uses a liquid crystal display element that comprises an alignment control monomer including an aromatic ester that undergoes photo-Fries rearrangement by light irradiation, and that employs a liquid crystal composition having a negative dielectric anisotropy. The invention also uses the liquid crystal composition.

Provided is a compound represented by formula (1) described below.

##STR00001##

In formula (1), a and b are independently 0, 1 or 2, and expressions: 0a+b3 hold, ring A.sup.1, ring A.sup.2, ring A.sup.3 and ring A.sup.4 are independently 1,4-cyclohexylene, for example, Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4 and Z.sup.3 are independently a single bond, alkylene having 1 to 10 carbons, or the like, Sp.sup.1 and Sp.sup.2 are independently a single bond, alkylene having 1 to 10 carbons, or the like, and P.sup.1 and P.sup.2 are independently a specific polymerizable group.

Disclosed is a liquid crystal composition comprising one or more compounds represented by formula I and/or formula II and one or more compounds represented by formula III: ##STR00001##
wherein the definition of each substituent is given. The composition involved in the present invention has a low viscosity .sub.1, a high clearing point Tni and a large optical anisotropy n, and can realize a rapid response of liquid crystal display.

A display panel includes a first substrate, an electrode layer, and a display medium layer. The electrode layer is disposed on the first substrate. The display medium layer is disposed on the electrode layer and includes a filler and liquid crystal capsules. The liquid crystal capsules are distributed in the filler, and the filler has a birefringence difference n in a range from 0.02 to 0.175.

A liquid crystal cell includes a pair of facing substrates having a photo-alignment film, and a liquid crystal layer. The liquid crystal material contains a liquid crystal compound having a structure represented by any of the following chemical formula (1-1) and chemical formula (1-2):
A.sub.1-C.sub.nF.sub.2nX.sub.1-A.sub.2(1-1)
A.sub.1-X.sub.1C.sub.nF.sub.2n+1(1-2)
in the chemical formula (1-1), A.sub.1 is a phenyl group, a phenylene group, a naphthyl group, a naphthylene group, a cyclohexyl group, or a cyclohexylene group; A.sub.2 is a phenyl group, a phenylene group, a naphthyl group, or a naphthylene group (provided that a hydrogen atom in functional groups A.sub.1 and A.sub.2 is optionally substituted by a fluoro group, a chloro group, a bromo group, a methyl group, or an ethyl group); X.sub.1 is an oxygen atom or a direct bond; and n is an integer of 1 to 6. The photo-alignment film is obtained by subjecting a polymer film to a photo-alignment treatment.

The liquid crystal display device of the disclosure has: a first substrate; a plurality of pixel electrodes formed on the first substrate; a second substrate; a counter electrode formed on the second substrate and facing the pixel electrode; a liquid crystal layer including a liquid crystal composition between the pixel electrode and the counter electrode; and an alignment control layer formed of a polymer containing an alignable monomer that is one component of the liquid crystal composition, in which the alignment control layers are each formed on a side of the first substrate and on a side of the second substrate. The alignable monomer is a polymerizable polar compound having a mesogen moiety formed of at least one ring, and a polar group.

A negative dielectric anisotropy liquid crystal composition having one or more A-R.sub.0B compounds represented by formula I above as a first component, and one or more compounds represented by formula II above as a second component: ##STR00001##
The liquid crystal composition has a good stability against light and heat, a lower viscosity, a wider refractive index that may be achieved by adjusting the monomer ratio, and a higher clearing point (a very wide service temperature range). The liquid crystal composition has a higher light transmittance, thus allowing a display device to have a higher brightness or an energy saving effect.