A liquid-crystalline medium, in particular based on a mixture of polar compounds, having compounds of formulae Y, CY, PY and/or LY, and compounds of formula S1 and/or S2:

##STR00001##

The present invention relates to compounds that have ultraviolet light absorbing properties, and which can also have mesogenic properties. The present invention also relates to compositions that include one or more such compounds, and to articles of manufacture that include one or more such compounds, such as optical elements that include an optical substrate and a layer that includes at least one compound of the present invention.

Compounds that have ultraviolet light absorbing properties, and which can also have mesogenic properties. Compositions that include one or more such compounds. Articles of manufacture that include one or more such compounds, such as optical elements that include an optical substrate and a layer that includes at least one such compound.

Object To provide a tilt-imparted liquid crystal display element that is obtained through UV irradiation of a polymerizable liquid crystal composition, whose drive voltage can be reduced with a fast decay time maintained, and that is well balanced between characteristics, such as decay time, drive voltage, and transmittance. A polymerizable liquid crystal composition for use in it is also provided. Solution A liquid crystal display element has polymer networks formed in the liquid crystal phase 5 in FIG. 3. The polymer networks are formed by polymerizing a polymerizable liquid crystal composition that contains, as essential ingredients, a radically polymerizable monomer component (A), a liquid crystal material (B), and a polymerization initiator (C) that has a molecular structure resulting from substituting any two or more hydrogen atoms in the aromatic nucleus in the molecular structure of an alkylphenone-based photopolymerization initiator, for example with a C1-10 alkyl group (i).

An electro-polarizable compound has the following general formula: ##STR00001##
Core1 is an aromatic polycyclic conjugated molecule having two-dimensional flat form and that self-assembles to form supramolecular structures. R1 are electron donor groups connected to Core1 and R1 are electron acceptor groups connected to Corel, m is number of acceptor groups R1, m is a number of donor groups R. The numbers m and m are equal to 0, 1, 2, 3, 4, 5 or 6, but both m and m are not both equal to 0. R2 is a substituent comprising one or more ionic groups connected to Core1 directly or via a connecting group; a number p of ionic groups R2 is 0, 1, 2, 3 or 4. The fragment marked NLE has a nonlinear effect of polarization. Core2 is a self-assembling electro-conductive oligomer, a number n of the such oligomers is 0, 2, or 4. R3 is a substituent comprising one or more ionic groups connected to Core2; a number s of the ionic groups R3 is 0, 1, 2, 3 or 4. R4 is a resistive substituent electrically insulating the supramolecular structures from each other. A number k of substituents R4 is 0, 1, 2, 3, 4, 5, 6, 7 or 8.

A liquid-crystalline medium, in particular based on a mixture of polar compounds, having compounds of formulae Y, CY, PY and/or LY, and compounds of formula S1 and/or S2: ##STR00001##

There is provided a polymerizable composition, by which discoloration or alignment defects are less likely to occur when a filmy polymer, which is obtained by adding a polymerizable compound to the polymerizable composition and polymerizing this composition, is irradiated with ultraviolet light. There are also provided a polymer obtained by polymerizing the polymerizable composition, and an optically anisotropic body using the polymer. The present invention provides a polymerizable low-wavelength dispersive or polymerizable reverse-wavelength dispersive compound having a partial structure represented by Formula (Z-0). Further, the present invention provides a composition containing the compound; a polymer obtained by polymerizing the composition; and an optically anisotropic body obtained by using the polymer.

##STR00001##

Liquid crystal polymerization films, prepared by applying a polymerizable liquid crystal composition containing a polymerizable liquid crystal compound represented by formula (2) on an alignment film prepared by calcinating a composition containing a polymer represented by a repeating unit of formula (1), and subsequently polymerizing the polymerizable liquid crystal composition.

##STR00001##

In formula (1), R.sup.1 is independently a tetravalent group, R.sup.2 is independently a divalent functional group and R.sup.3 is independently a hydrogen atom or a monovalent functional group.

PG.sup.1-Sp.sup.1-R.sup.4-Sp.sup.2-PG.sup.2(2)

In formula (2), R.sup.4 represents a divalent group formed by combining five or more and nine or less of alicycles and/or aromatic rings, SP.sup.1 and SP.sup.2 represent a spacer group, and PG.sup.1 and PG.sup.2 represents an alkyl group, an alkoxyl group, a cyano group, fluorine or a polymerizable functional group, in which either group is the polymerizable functional group.

An electro-polarizable compound has the following general formula:

##STR00001##

Core1 is an aromatic polycyclic conjugated molecule having two-dimensional flat form and that self-assembles to form supramolecular structures. R1 are electron donor groups connected to Core1 and R1 are electron acceptor groups connected to Corel, m is number of acceptor groups R1, m is a number of donor groups R. The numbers m and m are equal to 0, 1, 2, 3, 4, 5 or 6, but both m and m are not both equal to 0. R2 is a substituent comprising one or more ionic groups connected to Core1 directly or via a connecting group; a number p of ionic groups R2 is 0, 1, 2, 3 or 4. The fragment marked NLE has a nonlinear effect of polarization. Core2 is a self-assembling electro-conductive oligomer, a number n of the such oligomers is 0, 2, or 4. R3 is a substituent comprising one or more ionic groups connected to Core2; a number s of the ionic groups R3 is 0, 1, 2, 3 or 4. R4 is a resistive substituent electrically insulating the supramolecular structures from each other. A number k of substituents R4 is 0, 1, 2, 3, 4, 5, 6, 7 or 8.