The present application relates to novel compounds and to devices which contain these compounds. The application also relates to a device for regulating the passage of energy from an outside space into an inside space, to a window containing the said device, and to uses of the said devices and compounds.

The present invention relates to a temperature-reactive device for the regulation of light transmission, containing a liquid-crystalline medium and a compound of formula I, capable of promoting or inducing homeotropic alignment to the adjacent liquid crystal medium at a given temperature. The invention furthermore relates to a process for the temperature-dependent control of light transmission through a layer of a liquid-crystalline medium.

The present invention relates to liquid crystalline media comprising one or more benzothiadiazol derivatives of formula I,

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in which R.sup.11, R.sup.12, A.sup.11, A.sup.12, A.sup.21, A.sup.22, Z.sup.11, Z.sup.12, Z.sup.21, Z.sup.22, W, X.sup.11, X.sup.12, r and s have the meanings indicated in claim 1, to the use of such liquid crystal media for optical, electro-optical and electronic purposes, in particular in devices for regulating the passage of energy from an outside space into an inside space, for example in windows.

Thermochromic filters are constructed using absorptive, reflective, or fluorescent dyes, molecules, polymers, particles, rods, or other orientation-dependent colorants that have their orientation, order, or director influenced by carrier materials, which are themselves influenced by temperature. These order-influencing carrier materials include thermotropic liquid crystals, which provide orientation to dyes and polymers in a Guest-Host system in the liquid-crystalline state at lower temperatures, but do not provide such order in the isotropic state at higher temperatures. The varying degree to which the absorptive, reflective, or fluorescent particles interact with light in the two states can be exploited to make many varieties of thermochromic filters. Thermochromic filters can control the flow of light and radiant heat through selective reflection, transmission, absorption, and/or re-emission. The filters have particular application in passive or active light-regulating and temperature-regulating films, materials, and devices, and particularly as construction materials and building and vehicle surfaces.

The application relates to a device for regulating the entry of light into a room, which comprises a switchable layer of specific design comprising a twisted nematic liquid-crystalline medium and a dichroic compound.

The present application relates to mixtures which have liquid-crystalline properties. The application furthermore relates to the use of the mixtures in devices which regulate the transmission of light through an area element.

The present application relates to novel compounds and to devices which contain these compounds. The application also relates to a device for regulating the passage of energy from an outside space into an inside space, to a window containing the said device, and to uses of the said devices and compounds.

The present application relates to a device for regulating the passage of light through a light-transmitting area which comprises a switching layer comprising a liquid-crystalline medium comprising at least one dichroic dye, where the parameters degree of light transmission and degree of anisotropy of the device are selected in a certain manner.

The invention relates to a device for the regulation of light transmission, preferably a window, more preferably a privacy window, comprising a liquid crystalline medium exhibiting a converse flexoelectric effect, and which is sandwiched between two substrates, wherein at least one substrate is provided with an electrode structure.

A liquid crystal polyester comprising a repeating unit derived from an aromatic hydroxycarboxylic acid. The content of the repeating unit derived from an aromatic hydroxycarboxylic acid is 80% or more based on 100% of a total number of all repeating units of the liquid crystal polyester. The repeating unit derived from an aromatic hydroxycarboxylic acid comprises a repeating unit (A1) represented by the formula (A1) and a repeating unit (A2) represented by the formula (A2). A ratio [repeating unit (A2)/repeating unit (A1)] is 1.2 or larger. A molar ratio [phenolic hydroxyl groups/(the phenolic hydroxyl groups+acyl groups)] is 0.3 or lower, as calculated by .sup.1H-NMR.
OAr.sup.11CO(A1)
OAr.sup.12CO(A1)
Ar.sup.11 represents a phenylene group and Ar.sup.12 represents a naphthylene group. A hydrogen atom is optionally substituted.