A liquid crystal composition and a display device are provided. The liquid crystal composition includes a compound having a structure represented by general formula (I) and a compound having a structure represented by general formula (II), ##STR00001## and L.sub.1, L.sub.2, L.sub.3 and L.sub.4 are independently selected from ##STR00002## Z.sub.1 is selected from a single bond or —C≡C—; R.sub.1, R.sub.2 and R.sub.3 are independently selected from alkyl, alkenyl, alkynyl, haloalkyl or OR.sub.4; and R.sub.4 is selected from alkyl, alkenyl, alkynyl or haloalkyl.

The present invention provides a liquid crystal composition, containing: one kind or two or more kinds of a first monomer having a first mesogenic skeleton, at least one polymerizable group represented by the general formula (PG1) linked to the first mesogenic skeleton, and at least one polar group linked to the mesogenic skeleton or the polymerizable group; and one kind or two or more kinds of a second monomer having a second mesogenic skeleton and a polymerizable group represented by the general formula (PG2) linked to the second mesogenic skeleton, and having a chemical structure different from that of the first monomer, in an amount of more than 0.4% by mass, which is excellent in vertical alignment, burn-in characteristics (change with time of pretilt angle), and compatibility, and provides a liquid crystal display element using the liquid crystal composition.

A liquid crystal composition and a display device are provided. The liquid crystal composition includes a compound having a structure represented by general formula (I) and a compound having a structure represented by general formula (II),

##STR00001##

and L.sub.11, L.sub.2, L.sub.3 and L.sub.4 are independently selected from

##STR00002##

Z.sub.1 is selected from a single bond or —C≡C—; R.sub.1, R.sub.2 and R.sub.3 are independently selected from alkyl, alkenyl, alkynyl, haloalkyl or OR.sub.4; and R.sub.4 is selected from alkyl, alkenyl, alkynyl or haloalkyl.

Provided is a liquid crystal alignment agent that makes it possible to obtain a liquid crystal alignment film having a superior balance among solvent resistance, liquid crystal alignment properties, and voltage holding ratio. The liquid crystal alignment agent contains a polymer [P] including: at least one ring structure of an oxetane ring and an oxirane ring; (B) a functional group that reacts with at least one of the oxetane ring and the oxirane ring by heating; and (C) an optically aligning group.

Disclosed is a liquid crystalline epoxy compound wherein an epoxy group is positioned at a side chain of the longer direction of a mesogen group and each of the mesogen group and the epoxy group is connected to the center of the molecular structure through a flexible linkage. Since the liquid crystalline epoxy compound includes an epoxy group positioned at a side chain of the longer direction of a mesogen group and each of the mesogen group and the epoxy group is connected to the center of the molecular structure through a flexible linkage, the interaction between the mesogens in a cured resin product occurs significantly without weakening even after curing, thereby improving the heat conductivity of the resin compound through the active heat transfer between the mesogens.

The present invention provides a liquid crystal composition, containing: one kind or two or more kinds of a first monomer having a first mesogenic skeleton, at least one polymerizable group represented by the general formula (PG1) linked to the first mesogenic skeleton, and at least one polar group linked to the mesogenic skeleton or the polymerizable group; and one kind or two or more kinds of a second monomer having a second mesogenic skeleton and a polymerizable group represented by the general formula (PG2) linked to the second mesogenic skeleton, and having a chemical structure different from that of the first monomer, in an amount of more than 0.4% by mass, which is excellent in vertical alignment, burn-in characteristics (change with time of pretilt angle), and compatibility, and provides a liquid crystal display element using the liquid crystal composition.

There are provided a compound having a thermotropic liquid crystalline structure and a polyethylene glycol polymer. The compound is obtained by modifying an epoxide functional group in a thermotropic liquid crystalline molecule. The polyethylene glycol polymer is obtained by ring-opening polymerization thereof. The polyethylene glycol main chain polymer is easy to form in thin film, bulk, or fiber form, and has a high thermal conductivity and thus can be used alone or in the form of a composite material as a heat-dissipating polymer.

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.

A polymerizable 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 from the composition and a liquid crystal display device having the composite are shown. The polymerizable compound has three or four rings in a serial arrangement and not being mutually condensed, and has three or more polymerizable groups among which at least one is bonded with a ring which is not an either terminal of the three or four rings. The polymerizable composition contains the above polymerizable compound and a liquid crystal composition. The liquid crystal composite is prepared from the above polymerizable composition, and the liquid crystal display device has the liquid crystal composite.

Disclosed is a liquid crystalline epoxy compound wherein an epoxy group is positioned at a side chain of the longer direction of a mesogen group and each of the mesogen group and the epoxy group is connected to the center of the molecular structure through a flexible linkage. Since the liquid crystalline epoxy compound includes an epoxy group positioned at a side chain of the longer direction of a mesogen group and each of the mesogen group and the epoxy group is connected to the center of the molecular structure through a flexible linkage, the interaction between the mesogens in a cured resin product occurs significantly without weakening even after curing, thereby improving the heat conductivity of the resin compound through the active heat transfer between the mesogens.