A polar compound has a high chemical stability, high ability to align liquid crystal molecules and high solubility in a liquid crystal composition, and causes no decrease of liquid crystallinity of the liquid crystal composition, a liquid crystal composition contains the compound, and a liquid crystal display device includes the composition. The compound is represented by formula (1), the composition contains the compound, and the liquid crystal display device uses the composition. ##STR00001## In formula (1), R.sup.1 is alkyl having 3 to 15 carbons, alkenyl having 4 to 15 carbons or the like; a is an integer from 2 to 12; and R.sup.2 is a group represented by formula (1a), formula (1b) or formula (1c). ##STR00002## In the formulas, S.sup.1 and S.sup.2 are independently a single bond, alkylene having 1 to 10 carbons; S.sup.3 is >CH— or >N—; S.sup.4 is >C< or >Si<; and X.sup.1 is —OH, —NH.sub.2 or the like.

A problem is to provide a liquid crystal compound satisfying at least one physical property such as high stability to heat and light, a high clearing point (or high maximum temperature), a 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 solution is a compound represented by formula (1). ##STR00001## In which, R.sup.1 is alkyl having 1 to 10 carbons or the like; Z.sup.1, Z.sup.2 and Z.sup.3 are independently a single bond, —COO—, —OCH.sub.2—, —CF.sub.2O— or the like, and at least one of Z.sup.1, Z.sup.2 and Z.sup.3 is —CF.sub.2O—; X.sup.1 is hydrogen, fluorine, —CF.sub.3 or —OCF.sub.3; and L.sup.1, L.sup.2, L.sup.3 and L.sup.4 are independently hydrogen, fluorine or chlorine.

The invention provides a liquid crystal compound satisfying at least one of physical properties such as a high stability to heat or light, a high clearing point (or a high maximum temperature), a low minimum temperature of a liquid crystal phase, a small viscosity, a suitable optical anisotropy, a small dielectric anisotropy, a suitable elastic constant and a good compatibility with other liquid crystal compounds, a liquid crystal composition including this compound, and a liquid crystal display device containing this composition. The invention provdes a compound represented by formula (1):

##STR00001##

where R.sup.1 and R.sup.2 is alkyl having 1 to 20 carbons or the like; one of L.sup.1 and L.sup.2 is both hydrogens, and the other is both fluorines; Z.sup.1 and Z.sup.2 are independently a single bond, —COO—, —OCO—, —OCH.sub.2—, —CH.sub.2O—, —CF.sub.2O—, —OCF.sub.2—, —CH.sub.2CH.sub.2—, —CH═CH—, —C≡C— or the like.

Provided is a liquid crystal compound satisfying at least one of physical properties such as high stability to heat and light, a high clearing point (or high maximum temperature), 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, represented by formula (1):

##STR00001##

wherein, in formula (1), R.sup.1 is alkoxy having 1 to 9 carbons or the like; R.sup.2 is alkenyl having 2 to 10 carbons; Z.sup.1 and Z.sup.2 are independently a single bond, —CH.sub.2CH.sub.2—, —CH═CH— or the like; and a and b are independently 0 or 1.

Provided are a polymerizable compound having at least one monovalent group (A), a polymerizable composition containing the polymerizable compound, a liquid crystal composite prepared from the polymerizable composition, and a liquid crystal device having the polymerizable composition. ##STR00001## In monovalent group (A), R.sup.1 and R.sup.2 are independently hydrogen, halogen or alkyl having 1 to 20 carbons, and in the alkyl, at least one piece of —CH.sub.2— may be replaced by —O— or —S—, and at least one piece of —(CH.sub.2).sub.2— may be replaced by —CH═CH—, and in the groups, at least one hydrogen may be replaced by halogen.

The present invention relates to an assembly of switching layers for dimming and scattering of light and to window elements comprising the arrangement of switching layers.

Provided is a liquid crystal composition, which comprises a component prepared from one or more compounds selected from a general formula I; and a component prepared from one or more compounds selected from a general formula II. The liquid crystal composition has the characteristics of low viscosity, high reliability, appropriate optical anisotropy, and appropriate dielectric anisotropy, and is applicable to liquid crystal display devices. ##STR00001##

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.

A liquid crystal display device having a liquid crystal composition, requiring neither an alignment film nor alignment treatment on a substrate. The problem is solved by a low molecular weight polar compound for homogeneously aligning a liquid crystal medium relative to the substrate, for example, the low molecular weight polar compound represented by formula (1).
Formula 95
M-P(1) In formula (1), M is a nonpolar group having 1 or more carbons, and P is a polar group.

The problem is to provide a polymerizable compound having suitable polymerization reactivity, a high conversion ratio, low polymerization starting temperature, and high solubility in a liquid crystal composition; a liquid crystal composition containing the compound; and a liquid crystal display device including the composition.

A means thereof includes a compound represented by formula (1) and a liquid crystal composition containing the compound.

##STR00001##

In formula (1), R.sup.1, R.sup.2 and R.sup.3 are independently alkyl or the like; n is 0 or the like; ring A.sup.1 is phenyl or the like, and ring A.sup.2 and ring A.sup.3 are independently 1,4-phenylene or the like; Z.sup.1 and Z.sup.2 are independently a single bond or the like; Sp.sup.1 to Sp.sup.4 are a single bond or the like; a is 1 or the like; c, d and e are independently 0 or 1, and a sum of c, d and e is 1 or the like; and P.sup.1 to P.sup.4 are a polymerizable group, and at least one of P.sup.1 to P.sup.4 is a polymerizable group represented by formula (P-1).

##STR00002##