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.

An object of the present invention is to provide a composition that realizes high n, has a wide liquid crystal phase temperature range, small viscosity, excellent low-temperature solubility, and high resistivity and voltage holding ratio, and is stable against heat and light, and to provide a liquid crystal composition having an excellent lens effect and excellent chemical stability using the composition, and a liquid crystal display device and a liquid crystal lens that use the liquid crystal composition. The present invention provides a liquid crystal composition that contains one or two or more compounds represented by general formula (i) and one or two or more compounds represented by general formula (ii), a liquid crystal display device using the liquid crystal composition, a liquid crystal lens using the liquid crystal composition, and a birefringence lens for stereoscopic image display using the liquid crystal composition.

Described herein are liquid crystal compositions and derivative mixtures thereof that can allow for the adjustment of their refractive indices by the application of an electric field. In addition, selectively dimmable reverse-mode polymer dispersed liquid crystal (PDLC) elements and devices using the aforementioned compositions are also described, which are transparent when no voltage is applied and opaque when a voltage is applied.

A polyamic acid composition is polymerized by dianhydride monomers and diamine monomers. A range of molar ratio of the dianhydride monomers to the diamine monomers is from 0.9 to 1.1. The diamine monomers have a combination of specific functional groups containing at least one nitrogen heterocycle structure, at least one liquid crystal structure, and at least one soft structure, wherein the diamine monomer containing nitrogen heterocycle structure has a molar weight percentage of 3% to 8% of a total molar weight of the diamine monomers, and the diamine monomers containing at least one liquid crystal structure and at least one soft structure have a molar weight percentage of 92% to 97% of the total molar weight of the diamine monomers. The disclosure further relates to a polyimide film, a copper clad laminate, and a printed circuit board.

Liquid-crystalline media comprising one or more compounds of formula T

##STR00001##

as defined in claim 1, and high-frequency components comprising these media, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, tunable filters, tunable metamaterial structures, and electronic beam steering antennas, e.g. phased array antennas.

There is provided an element which has large dielectric anisotropy and low dielectric loss in a high frequency range, has high reliability, and is used for phase control of an electromagnetic wave signal with a frequency of 1 MHz to 400 THz. An element in which a liquid crystal composition contains a compound represented by the following Formula (1) and has a refractive index anisotropy of 0.30 or more at a wavelength of 589 nm, and a polyimide alignment film contains 10% or more of a repeating unit represented by the following Formula (2) with respect to all repeating units:

##STR00001##

The present invention relates to liquid-crystalline media comprising one or more pleochroic compounds, and one or more compounds selected from the group of compounds of formulae I, II and III,

##STR00001##

in which the groups have the meanings as set forth in claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

The present invention relates to liquid-crystalline media comprising one or more compounds of formula T ##STR00001##
and one or more compounds selected from the group of compounds of formulae I, II and III, ##STR00002##
in which the parameters have the meaning indicated in Claim 1, and to components comprising these media for high-frequency technology, in particular phase shifters and microwave array antennas.

The invention relates to a liquid crystalline medium, characterised in that it comprises one or more compounds of formula A ##STR00001##
and
one or more compounds of formula II ##STR00002##
wherein the parameters have the meaning indicated in claim 1, and to high-frequency components comprising the same, especially microwave components for high-frequency devices, such as devices for shifting the phase of microwaves, in particular microwave phased-array antennas.

Provided are a liquid-crystal-medium having stability to heat, light and so forth, a wide liquid-crystal-phase temperature-range and significantly large dielectric-anisotropy and developing an optically isotropic liquid-crystal-phase; and various optical-devices used in a wide temperature-range, having short response-time, a large contrast-ratio and low drive-voltage and suppressing decrease in an effective dielectric-constant in a high-frequency range. A Liquid-crystal composition contains achiral-component T containing at least one compound selected from a first component represented by formula (1) and at least one compound selected from a second component represented by formula (2) or (3) and a chiral-agent to develop optically-isotropic liquid-crystal-phase: ##STR00001##
In formula (1), R.sup.1: alkyl, ring A.sup.1: 1,4-cyclohexylene, ring B.sup.1: 1,4-phenylene, L.sup.11 to L.sup.14: fluorine, Y.sup.1: fluorine, n.sup.1: 1 or 2, R.sup.2: alkyl, Z.sup.21 and Z.sup.22: single-bond or CF.sub.2O, L.sup.21 to L.sup.23: fluorine, Y.sup.2: fluorine, R.sup.3: alkyl, Z.sup.31 and Z.sup.32: single-bond or CF.sub.2O, L.sup.31 to L.sup.34: fluorine, Y.sup.3: fluorine, for example.