Provided is a liquid crystal composition capable of forming an optically anisotropic layer, and method thereof, in which a variation in a twisted angle of liquid crystal compound in an in-plane direction is suppressed an optical film, and a circularly polarizing plate for an organic EL display. The liquid crystal composition contains a liquid crystal, optically active compound A which is a photosensitive optically active compound whose helical twisting power changes upon irradiation with light and has a molar absorption coefficient of 5,000 M.sup.−1.Math.cm.sup.−1 or more with respect to light having a wavelength of 365 nm, and an optically active compound B having a molar absorption coefficient with respect to light having a wavelength of 365 nm smaller than the molar absorption coefficient of the optically active compound A, in which a mass content ratio of the optically active compound A to the liquid crystal compound is less than 0.01.

The present invention relates to liquid-crystalline media comprising one or more mesogenic compounds, one or more chiral compounds, and one or more polymerisable mesogenic compounds, wherein the media exhibit a pitch of 0.55 μm or more and a clearing point of 80° C. or more and wherein the one or more polymerisable mesogenic compounds are contained in an amount, based on the overall contents of the media, of 5% by weight or less. The present invention further relates to modulation materials obtainable from the media and to switching layers and window elements containing the materials.

An object of the present invention is to provide a compound which increases the intensity of HTP by exposure to irradiation with light such as ultraviolet rays, and a mixture including the compound. Another object of the present invention is to provide a liquid crystal composition, a cured product, an optically anisotropic body, and a reflective film.

The compound of the present invention is represented by General Formula (1).

##STR00001##

Chiral compounds of formula I ##STR00001##
wherein the paramters have the meaning given in claim 1, liquid crystal mixtures comprising at least one chiral compound of formula I, to chiral linear or crosslinked liquid crystal polymers obtainable by polymerizing a polymerizable mixture comprising at least one chiral compound of formula I, to the use of chiral compound of formula I and mixtures and polymers obtained thereof in liquid crystal displays, active and passive optical elements, adhesives, synthetic resins with anisotropic mechanical properties, cosmetic and pharmaceutical compositions, diagnostics, liquid crystal pigments, for decorative and security applications, nonlinear optics, optical information storage or as chiral dopants, and a liquid crystal display comprising a mixture comprising at least one chiral compound of formula I.

A liquid-crystalline medium which comprises at least one compound selected from the group of compounds of the formulae IA to IH, ##STR00001##
in which Z.sup.1 denotes a single bond, —CH.sub.2CH.sub.2—, —CH═CH—, —CH.sub.2O—, —OCH.sub.2—, —CF.sub.2O—, —OCF.sub.2—, —COO—, —OCO—, —C.sub.2F.sub.4—, —(CH.sub.2).sub.4—, —CHFCHF—, —CF.sub.2CH.sub.2—, —CH.sub.2CF.sub.2—, —C≡C—, —CF═CF—, —CH═CHCHO— or —CH.sub.2CF.sub.2O—,
and the use thereof for an active-matrix display, in particular based on the VA, PSA, PS-VA, PALC, FFS, PS-FFS, SA-VA, PS-IPS or IPS effect.

A method for obtaining a material containing mesogenic compounds forming a liquid crystal mix with a stabilized blue phase. The method includes the steps of a) inducing the liquid crystal mix, contained in a chemical composition, to form the blue phase, then b) illuminating the chemical composition with a light beam of visible wavelength in order to trigger the polymerization of monomers contained in the chemical composition, to obtain the material comprising the liquid crystal mix in the blue phase stabilized by the polymerized monomers. The chemical composition contains a mesogenic system and a chemical photo-initiator system adapted to trigger the polymerization of the monomers when illuminated by the light beam of visible wavelength, in which the mesogenic system includes the mesogenic compounds forming the liquid crystal mix, a chiral dopant adapted to induce the blue phase, and a monomer mix comprising the monomers adapted to polymerize.

The present invention provides the following: a photo alignment method-use liquid crystal aligning agent used to obtain a photo alignment method-use liquid crystal alignment film that does not cause bright spots even when negative liquid crystals are used, and that is capable of achieving good after-image characteristics; a liquid crystal alignment film obtained from the liquid crystal aligning agent; and a liquid crystal display element provided with the liquid crystal aligning agent. Provided is the liquid crystal aligning agent which contains a polyimide or polyimide precursor obtained from a reaction between: a tetracarboxylic acid dianhydride represented by formula (1) (in the formula, X.sup.1 is as set forth in the present specification) or a derivative thereof; and a diamine component that contains a diamine represented by formula (2) (in the formula, R.sup.1, Z.sup.1 and n are as set forth in the present specification).

Disclosed is a polymerizable compound having a structural formula as represented by the following formula I: ##STR00001##
The polymerizable compound disclosed in the present invention has a plurality of ring systems, and the entire molecular structure thereof is curved and twisted. The present invention further discloses a liquid crystal medium comprising the polymerizable compound, the polymerizable compound provided by the present invention has an appropriate polymerization rate in the liquid crystal medium, and the liquid crystal medium can be well applied to a PS-(polymer stabilized)- or PSA-(polymer stabilized alignment)-type liquid crystal display device. Further disclosed is a liquid crystal display device prepared from the liquid crystal medium.

A light modulation element comprising, preferably consisting of a cholesteric liquid crystalline medium sandwiched between two opposing substrates, an electrode arrangement, which is capable to allow the application of an electric field, which is substantially perpendicular to the main plane of substrate or the layer of the cholesteric liquid-crystalline medium, characterized in that one of the substrates is provided with a processed alignment layer adjacent to the cholesteric liquid crystalline medium and the other substrate is either provided with an unprocessed alignment layer adjacent to the cholesteric liquid crystalline medium or is not provided with an alignment layer. The invention is further related to a method of production of said light modulation element and to the use of said light modulation element in various types of optical and electro-optical devices, such as electro-optical displays, liquid crystal displays (LCDs), non-linear optic (NLO) devices, and optical information storage devices.

The present application relates to a liquid-crystalline material comprising a sterically hindered N-oxide and a dye. The invention furthermore relates to the use of the liquid-crystalline material in an optical switching device for regulation of the passage of sunlight.