The subject is to provide a liquid crystal composition that includes a polymerizable compound (or polymer) and a polar compound, where the homeotropic alignment of liquid crystal molecules can be achieved by the action of these compounds, and a liquid crystal display device including this composition.

The means concerns a nematic liquid crystal composition that has positive dielectric anisotropy and that includes a polymerizable compound as a first additive and a polar compound as a second additive, and the composition may include a specific liquid crystal compound having a large positive dielectric anisotropy and a specific liquid crystal compound having a high maximum temperature or a small viscosity, and concerns a liquid crystal display device including the composition.

Provided are a liquid crystal compound having larger dielectric anisotropy and superb heating reliability in comparison with a similar compound, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. A compound is represented by formula (1).

##STR00001##

In formula (1), for example, R.sup.1 is alkyl having 1 to 15 carbons, ring A.sup.1 is 1,4-cyclohexylene, 1,4-cyclohexenylene, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by halogen or tetrahydropyran-2,5-diyl; Z.sup.1 is a single bond or CF.sub.2O; L.sup.1 and L.sup.2 are hydrogen or halogen; Y.sup.1 and Y.sup.2 are hydrogen or halogen; and a is an integer from 1 to 4.

Provided is a polar compound that has high chemical stability and high capability of aligning liquid crystal molecules, and has a large voltage holding ratio when used in a liquid crystal display device.

The compound represented by formula (1) is applied.

##STR00001##

For example, R.sup.1 is alkyl having 1 to 15 carbons; rings A.sup.1 to A.sup.5 are 1,4-cyclohexylene or 1,4-phenylene; Z.sup.1 and Z.sup.5 are a single bond or alkylene having 1 to 10 carbons; a and b are 0 to 4, and a sum of a and b is 4 or less; d is 1 to 4; c and e are 0 to 4; P.sup.1 to P.sup.3 are a polymerizable group represented by formulas (P-1) to (P-5):

##STR00002##

in which M.sup.1 to M.sup.3 are hydrogen or alkyl having 1 to 5 carbons; and R.sup.2 is a group represented by formulas (1a) to (1c):

##STR00003##

in which Sp.sup.1 to Sp.sup.5 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.

Provided is a compound having an effect on preventing photolysis of a liquid crystal composition and having a high solubility in the liquid crystal composition, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. The compound is represented by formula (1), the liquid crystal composition contains the compound, and the liquid crystal display device uses the composition: ##STR00001##
wherein in formula (1), R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently hydrogen or alkyl having 1 to 4 carbons; R.sup.5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons; ring A.sup.1 is 1,4-cyclohexylene, 1,4-cyclohexenylene or the like; Z.sup.1 and Z.sup.2 are independently a single bond or alkylene having 1 to 10 carbons; and a is 0, 1, 2 or 3.

A solution is a compound represented by formula (1), a liquid crystal composition containing the compound and a liquid crystal display device including the composition. ##STR00001## In formula (1), R.sup.a and R.sup.b are independently alkyl having 1 to 30 carbons or the like; and X and Y are independently fluoroalkyl having 1 to 5 carbons, fluoroalkoxy having 1 to 5 carbons or pentafluorosulfanil, and one of X and Y may be fluorine.

A liquid crystal compound represented by

##STR00001##

R.sup.1 and R.sup.2 are independently hydrogen, fluorine, chlorine, alkyl or the like; ring A.sup.1 and ring A.sup.3 are independently 1,4-cyclohexylene, 1,4-phenylene or the like; and A.sup.2 is a divalent group represented by formula (A-1) or formula (A-2)

##STR00002##

Z.sup.1, Z.sup.2, Z.sup.3, Z.sup.4 and Z.sup.5 are independently a single bond, COO or the like; and a to d is 0, 1 or the like.

To provide a liquid crystal compound having high polymerization reactivity, a high conversion ratio and high solubility in a liquid crystal composition, a polymerizable composition containing the compound, a liquid crystal composite prepared using the composition, and a liquid crystal display device including the composite. The liquid crystal display device prepared using the polymerizable composition containing the compound represented by formula (1): ##STR00001##
wherein, in formula (1), P.sup.1 to P.sup.6 are a polymerizable group; S.sup.1 to S.sup.6 are a single bond, alkylene or the like; a1, a3 and a4 are an integer from 0 to 4, a2 is an integer from 1 to 4; ring A.sup.1 to ring A.sup.4 are a divalent group derived from benzene, naphthalene, anthracene, pyrimidine, pyridine or the like; Z.sup.1 to Z.sup.3 are a single bond, alkylene or the like, and at least one of Z.sup.1, Z.sup.2 and Z.sup.3 is CC; and b1 is 0 or 1.

Provided is a compound having an effect on preventing photolysis of a liquid crystal composition and having a high solubility in the liquid crystal composition, a liquid crystal composition containing the compound and a liquid crystal display device including the composition. The compound is represented by formula (1), the liquid crystal composition contains the compound, and the liquid crystal display device uses the composition.

##STR00001##

In formula (1), R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are independently hydrogen or alkyl having 1 to 4 carbons; R.sup.5 is hydrogen, hydroxy, oxy radical, alkyl having 1 to 10 carbons or alkoxy having 1 to 10 carbons; ring A.sup.1 is 1,4-cyclohexylene, 1,4-cyclohexenylene or the like; Z.sup.1 and Z.sup.2 are independently a single bond or alkylene having 1 to 10 carbons; and a is 0, 1, 2 or 3.

To provide a liquid crystal compound satisfying at least one of physical properties such as high stability to light, a high clearing point, a low minimum temperature of a liquid crystal phase, small viscosity, suitable optical anisotropy, large dielectric anisotropy, a large dielectric constant in a minor axis direction, a suitable elastic constant and excellent compatibility; a liquid crystal composition containing the compound; and a liquid crystal display device including the composition. The compound is represented by formula (1). ##STR00001##
For example, R.sup.1 is alkyl having 1 to 15 carbons, ring A.sup.1 to ring A.sup.4 are 1,4-cyclohexylene or 1,4-phenylene, Z.sup.1 to Z.sup.4 are a single bond, (CH.sub.2).sub.2, COO or CH.sub.2O, X.sup.1 is halogen, CN, CF.sub.3 or OCF.sub.3, L.sup.1 and L.sup.2 are hydrogen or fluorine, Y.sup.1 and Y.sup.2 are fluorine; a, b, c and d each are 0 or 1, and a sum thereof is 1 or 2.

A liquid crystal composition is provided containing a compound that is effective in preventing photolysis of the liquid crystal composition, and has high solubility in the liquid crystal composition. A liquid crystal display device including the composition is also provided. The liquid crystal composition contains a compound represented by formula (1), and a liquid crystal display device uses the composition: ##STR00001##
in which, in formula (1), R.sup.1 to R.sup.8 are hydrogen or alkyl having 1 to 4 carbons; ring A.sup.1 and ring A.sup.2 are cyclohexylene, phenylene, or naphthalenediyl; Z.sup.1, Z.sup.2 and Z.sup.3 are a single bond; and a and b are independently 1 or 2, and c is 0, 1 or 2.