Compound (1) is provided.

R.sup.1-MES-Sp.sup.1-P.sup.1(1)

In compound (1), R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having an at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons, and in the alkylene, at least one hydrogen is replaced by group (1a); P.sup.1 is group (1e) or (1f);

##STR00001##

wherein, M.sup.1, M.sup.2, M.sup.3 and M.sup.4 are hydrogen; Sp.sup.2 and Sp.sup.3 are a single bond or alkylene having 1 to 10 carbons; R.sup.2 is alkyl having 1 to 15 carbons; R.sup.3 is group (1g), (1h) or (1i);

##STR00002##

wherein, Sp.sup.4 and Sp.sup.5 are a single bond or alkylene having 1 to 10 carbons; S.sup.1 is >CH, and S.sup.2 is >C<; and X is OH.

A liquid crystal composition without requiring an alignment film or alignment treatment on a substrate. The problem is solved by a low molecular weight polar compound capable of homogeneously aligning a liquid crystal medium relative to the substrate, for example, a low molecular weight polar compound represented by formula (1).

M-P(1)

In formula (1), M is a nonpolar group having 1 or more carbons, and P is a polar group.

Disclosed is a liquid crystal composition comprising one or more compounds represented by formula I, one or more compounds represented by formula II, and one or more compounds represented by formula III:

##STR00001##

The liquid crystal composition has simultaneously a lower rotary viscosity, a better photoelectric performance, a higher clearing point, a good low temperature performance, and less display defects. Further disclosed is a liquid crystal display element or device comprising the liquid crystal composition.

There is provided a liquid crystal display element. The liquid crystal layer contains a liquid crystal composition between the first substrate and the second substrate. The first common electrode contains a transparent conductive material on the first substrate. The second common electrode contains a transparent conductive material on the second substrate. The pixel electrode contains a transparent conductive material. Distances R between the pixel electrode and the common electrode is smaller than distance G between the first substrate and the second substrate. The common electrode is disposed closer to the first substrate than the pixel electrode over nearly the entire surface of the first substrate. The liquid crystal composition has negative dielectric anisotropy and contains one or two or more compounds selected from the group of compounds represented by General Formula (i), General Formula (ii), and General Formula (iii).

An object of the present invention is to provide a composition that has positive , exhibits a liquid crystal phase over a wide temperature range, has low viscosity, excellent solubility at low temperatures, and high resistivity and voltage holding ratio, and is stable against heat and light. By using this composition, IPS or TN liquid crystal display devices and the like that have excellent display quality and suppress display failures such as image-sticking and drop marks are provided in high yield. Provided is a composition that contains at least one selected from the group consisting of compounds represented by general formulae (i) and (ii) and at least one compound represented by general formula (iii). Also provided is a liquid crystal display device that uses the composition and an IPS or FFS device that uses the composition.

Provided is a polymerizable liquid crystal compound represented by formula (1). ##STR00001## An aspect can be exemplified, in which, in formula (1), W.sup.1 is hydrogen or a substituent, A.sup.1 is 1,4-phenylene, 1,4-cyclohexylene or naphthalene-2,6-diyl, Z.sup.1 and Y.sup.1 are a connecting group, m and n each are an integer from 0 to 7, in which an expression: 3m+n8 holds, Q.sup.1 is a spacer, and PG is a polymerizable group.

Provided is a polar compound having high chemical stability, high capability of aligning liquid crystal molecules, high solubility in a liquid crystal composition, and a large voltage holding ratio when used in a liquid crystal display device. The compound is represented by formula (1): ##STR00001##
in which, for example, R.sup.1 is alkyl having 1 to 15 carbons; MES is a mesogen group having at least one ring; Sp.sup.1 is a single bond or alkylene having 1 to 10 carbons; M.sup.1 and M.sup.2 are hydrogen; and R.sup.2 is a group represented by formulas (1a) to (1c): ##STR00002##
in which, Sp.sup.2 and Sp.sup.3 are a single bond or alkylene having 1 to 10 carbons; S.sup.1 is >CH; S.sup.2 is >C<; and X.sup.1 is OH.

The invention relates to a RM lens obtainable from a polymerizable liquid crystalline medium comprising, a polymerizable liquid crystalline component A comprising one or more polymerizable mesogenic compounds, and at most 12% by weight of the total medium of a non-mesogenic component B. Moreover, the invention relates to the use of such birefringent RM lenses in electro optical devices, such as liquid crystal displays (LCDs) or other optical or electrooptical devices, for decorative or security applications.

To provide a liquid crystal composition having at least one or a suitable balance regarding two of characteristics such as high maximum or low minimum temperature of a nematic phase, small viscosity, suitable optical anisotropy, large dielectric anisotropy, large specific resistance, high stability to ultraviolet light or heat and a large elastic constant; and an AM device including the composition and having a short response time, a large voltage holding ratio, low threshold voltage, a large contrast ratio, a long service life and so forth. The liquid crystal composition contains a quencher as an additive component and a specific compound having large positive dielectric anisotropy as a first component, and a liquid crystal display device includes the composition. The composition may contain a specific compound having high maximum temperature or small viscosity as a second component, or a specific compound having negative dielectric anisotropy as a third component.

A liquid crystal composition for dimming that satisfies at least one of characteristics such as a high maximum temperature, a low minimum temperature, a small viscosity, a large optical anisotropy and a large negative dielectric anisotropy, or that is suitably balanced between at least two of these characteristics, and a liquid crystal dimming device including this composition. A liquid crystal composition for dimming that includes a specific compound having a large negative dielectric anisotropy as a first component and that may include a specific compound having a high maximum temperature or a low minimum temperature as a second component.