Devices for regulating light transmission

Abstract

The invention relates to a device for regulating light transmission. The application relates to a device for regulating light transmission, characterized in that the device has a layer containing a liquid crystal mixture, the liquid crystal mixture having characteristic structural units.

Description

[0001] This application is a divisional application of the Chinese patent application with application number 201480068767.6, application date November 26, 2014, and invention name “Device for adjusting light transmission”. Technical Field

[0002] The present application relates to a device for regulating light transmission, wherein the device has a layer comprising a liquid crystal material, the liquid crystal mixture comprising a dye compound and a compound having a characteristic structural unit. Background Art

[0003] In the context of the present application, the term light is understood to mean, in particular, electromagnetic radiation in the UV-A, VIS and NIR ranges. Also understood in particular is light of a wavelength which is not absorbed, or only slightly absorbed, by the materials commonly used for windows (e.g. glass). According to the commonly used definitions, the UV-A range is understood to mean wavelengths of 320 to 380 nm, the VIS range is understood to mean wavelengths of 380 to 780 nm, and the NIR range is understood to mean wavelengths of 780 to 2000 nm.

[0004] Preferably, the light whose transmission is conditioned by the device according to the invention is understood to be natural light. Natural light is light emitted by the sun. Natural light is preferably emitted directly by the sun. However, it can also be emitted indirectly by the sun by reflection, refraction or by absorption and subsequent emission by any material.

[0005] In the context of the present application, the term liquid crystal material is understood to mean a material that has liquid crystal properties under certain conditions. The term liquid crystal properties is well known to those skilled in the art and is generally understood in the same way as in the field of physical chemistry. In a narrow sense, liquid crystal materials are understood to mean materials that are liquid and have properties that depend on direction. Liquid crystal properties generally depend on temperature. Therefore, in a narrow sense, liquid crystal materials are understood to mean materials that have liquid crystal properties in a temperature range that includes room temperature.

[0006] The device for regulating the light transmission is a switching device which covers a plane and, depending on its switching state, more or less blocks the transmission of light through this plane.

[0007] Such a device may be based on different mechanisms and may be, for example, thermally switchable or electrically switchable.An example of an electrically switchable device for regulating light transmission is disclosed in WO 2009 / 141295 and the not yet published applications WO 2014 / 090367 and WO 2014 / 090373.

[0008] The device described in said application has a layer comprising a liquid crystal material, wherein the liquid crystal material comprises at least one dye compound and at least one host material. The host material is a mixture of different liquid crystal compounds.

[0009] Even though the devices disclosed in the above-mentioned prior art can be used well and have satisfactory performance, there is still a need for alternative devices. Particularly needed are devices in which the layer comprising liquid crystal material has a high stability and thus a long lifetime. It is particularly desirable that the liquid crystal material comprising the dye is a stable solution and / or that no crystallization or formation of new phases occurs in the liquid crystal material, especially at low temperatures. It is also desirable that the liquid crystal material of the device has a high anisotropy of absorption. Summary of the invention

[0010] It has surprisingly been found within the scope of the present invention that when liquid crystal materials having a clearing point of at least 95° C. and having the characteristic structural features shown below are used in devices, devices with extremely long lifetimes and high stability with respect to low temperatures are obtained.

[0011] The liquid crystal materials according to the invention comprising one or more dye compounds are characterized by one or more, preferably all, of the following properties: high solubility of the dye compound, high long-term stability of the solution at room and low temperatures, and high anisotropy of the absorption.

[0012] The subject of the present application is therefore a device for regulating light transmission, characterized in that the device has a layer comprising a liquid crystal material comprising a dye compound, wherein the liquid crystal material has a clearing point of at least 95° C. and comprises at least one compound V comprising at least one unit selected from the group consisting of units of the formulae (E-1), (E-2) and (E-3)

[0013]

[0014]

[0015] in

[0016] X is, at each occurrence, identically or differently, selected from F, Cl, Br, I, -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, and N3;

[0017] W is, at each occurrence, identically or differently, selected from F, Cl, Br, I, -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, and N3;

[0018] U is selected, identically or differently at each occurrence, from H, F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, N3 and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S;

[0019] The dashed line represents the remaining portion bound to the compound.

[0020] And at least one group U in each unit of formula (E-3) is selected from F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS and N3.

[0021] Preferably, X is selected, identically or differently at each occurrence, from F and -CN.

[0022] Preferably, W is equal to -CN.

[0023] Preferably, a maximum of four, particularly preferably a maximum of two, radicals U per unit of formula (E-3) are selected from the group consisting of F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS and N3. Very particularly preferably, exactly one radical U per unit of formula (E-3) is selected from the group consisting of F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS and N3. Furthermore, preferably in conjunction with the preferred embodiments, the remaining radicals U in the unit of formula (E-3) are equal to H.

[0024] Preferably, U is selected, identically or differently on each occurrence, from H, F and CN.

[0025] It is also preferred that compound V comprises at least one unit of the formula (E-1), particularly preferably exactly one unit of the formula (E-1).

[0026] Preferably, compound V comprises at least one unit of the formula (E-2), particularly preferably exactly one unit of the formula (E-2).

[0027] It is also preferred that compound V comprises exactly one unit selected from the group consisting of units of the formulae (E-1), (E-2) and (E-3). Particularly preferably, compound V comprises exactly one unit selected from the group consisting of units of the formulae (E-1) and (E-2).

[0028] Preferred embodiments of the unit of formula (E-1) are units of the following formulae (E-1-1) to (E-1-3):

[0029]

[0030] The dashed line represents the remainder of the compound bound to which:

[0031] X 1 is selected, identically or differently at each occurrence, from F, Cl, Br and I; and

[0032] X 2 is, at each occurrence, identically or differently selected from -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS and N3.

[0033] X 1 Preferably equal to F.

[0034] X 2 Preferably equal to CN.

[0035] Particularly preferred embodiments of the unit of formula (E-1) are units of the following formulae (E-1-1a) to (E-1-3a):

[0036]

[0037]

[0038] The dashed line represents the remaining portion bound to the compound.

[0039] A preferred embodiment of the unit of formula (E-2) is a unit of the following formula (E-2-1):

[0040]

[0041] The dashed line represents the remaining portion bound to the compound.

[0042] A preferred embodiment of the unit of formula (E-3) is a unit of the following formula (E-3-1):

[0043]

[0044] The dashed line represents the remaining portion bound to the compound.

[0045] Compound V preferably has a structure according to the formula

[0046]

[0047] in

[0048] R V1 , R V2represents, identically or differently on each occurrence, alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms, wherein one or more hydrogen atoms in the abovementioned radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S;

[0049] are selected identically or differently on each occurrence from the following groups or a unit of formula (E-1), (E-2) or (E-3);

[0050] Y is selected, identically or differently at each occurrence, from F, Cl, CN, and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S;

[0051] n is equal to 1, 2 or 3; and

[0052] At least one group A unit selected from formula (E-1), (E-2) or (E-3).

[0053] Preferably, the units of formula (E-1) or (E-2) or (E-3) are present in their preferred embodiments, in particular in the embodiments corresponding to formula (E-1-1a), (E-1-2a), (E-1-3a), (E-2-1) and (E-3-1).

[0054] Preferably, the compound of formula (V) comprises exactly one unit selected from the units of the formulae (E-1), (E-2) and (E-3), particularly preferably exactly one unit selected from the units of the formulae (E-1) and (E-2).

[0055] The index n in formula (V) is preferably equal to 1 or 2.

[0056] In this application, for ease of reading, For example Smoothly shortened to "A x ”, for example, “A V1 ”.

[0057] Preferably, A V1 In each occurrence, the same or different selection is made from and units of formula (E-1-1a), (E-1-2a), (E-1-3a), (E-2-1) and (E-3-1).

[0058] Preferred embodiments of compound V correspond to the following formulae (V-1) to (V-8):

[0059]

[0060]

[0061] Where R V1 and R V2 and X are defined as above.

[0062] Preferably, for compounds of formula (V-1) to (V-8), the group R V1 and R V2 is selected identically or differently on each occurrence from alkyl or alkoxy radicals having 1 to 10 C atoms.

[0063] Preferably, for the compounds of the formulae (V-1) to (V-4), the group X is selected, identically or differently on each occurrence, from F and CN. Particularly preferably, the group X is equal to F.

[0064] The liquid crystal material preferably has a clearing point of at least 100° C., particularly preferably at least 105° C.

[0065] It is also preferred that the liquid crystal material is a nematic liquid crystal at least in the temperature range of -20°C to 100°C, particularly preferably at least in the temperature range of -30°C to 100°C, very particularly preferably at least in the temperature range of -40°C to 105°C, and most preferably at least in the temperature range of -50°C to 105°C.

[0066] It is also preferred that the liquid crystal material has a dielectric anisotropy Δε of -2 to -10, preferably -3 to -8, particularly preferably -4 to -7. The method for measuring the dielectric anisotropy is given in the Examples.

[0067] It is also preferred that the liquid crystal material has an optical anisotropy Δn of 0.01 to 0.3, particularly preferably 0.03 to 0.20. The method for measuring the optical anisotropy is given in the examples.

[0068] Furthermore, the liquid crystal material is preferably a mixture of different organic compounds which themselves preferably have liquid crystal properties. Particularly preferably, the liquid crystal material comprises 8 to 30 different organic compounds, very particularly preferably 10 to 25 different organic compounds.

[0069] The organic compound preferably has an elongated shape, ie its dimension in one of the three spatial directions is significantly greater than its dimensions in the other two spatial directions.

[0070] A large number of organic compounds with the described properties are known to the person skilled in the art. Particularly preferred as components of the liquid crystal material according to the present application are organic compounds derived from two or more, preferably two, three or four six-membered rings (especially cyclohexane rings, cyclohexene rings, benzene rings, pyridine rings, pyrimidine rings and tetrahydropyran rings) connected in the para position.

[0071] The compound V is preferably an organic compound as described above. Preferably, the liquid crystal material contains 1 to 20 compounds V each having a different structure, particularly preferably 5 to 15 compounds V each having a different structure.

[0072] Preferably, the liquid crystal material contains one or more compounds of the following formula (F):

[0073]

[0074] in

[0075] R 1 , R 2 represents F, Cl, -CN, -NCS, -SCN, R, etc., identically or differently on each occurrence 3 -O-CO-, R 3 -CO-O- or an alkyl or alkoxy radical having 1 to 10 C atoms or an alkenyl or alkenyloxy radical having 2 to 10 C atoms, wherein one or more hydrogen atoms in the radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S; and

[0076] R 3 represents, identically or differently on each occurrence, an alkyl group having 1 to 10 C atoms, in which one or more hydrogen atoms may be replaced by F or Cl and in which one or more CH2 groups may be replaced by O or S; and

[0077] A 1 are selected identically or differently on each occurrence from the following groups

[0078]

[0079]

[0080] in

[0081] Y is selected, identically or differently on each occurrence, from F, Cl, CN and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S; and

[0082] Z 1is selected, identically or differently at each occurrence, from -CO-O-, -O-CO-, -CF2-CF2-, -CF2-O-, -O-CF2-, -CH2-CH2-, -CH=CH-, -CF=CF-, -CF=CH-, -CH=CF-, -C≡C-, -OCH2-, -CH2O-, and a single bond; and

[0083] a has a value of 0, 1, 2, 3, 4, 5 or 6, preferably 0, 1, 2 or 3, particularly preferably 1, 2 or 3.

[0084] Preferably, the liquid crystal material contains no compounds having siloxane groups, particularly preferably no compounds having silicon.

[0085] It is further preferred if the liquid-crystalline material has a total proportion of compound V of at least 40% by weight, particularly preferably at least 50% by weight, very particularly preferably at least 60% by weight, most preferably at least 70% by weight.

[0086] It is also preferred that the liquid crystal material comprises one or more compounds corresponding to formula (F-1)

[0087] in

[0088] R 11 , R 12 represents F, Cl, -CN, -NCS, -SCN, R, etc., identically or differently on each occurrence 3 -O-CO-, R 3 -CO-O- or an alkyl or alkoxy radical having 1 to 10 C atoms or an alkenyl or alkenyloxy radical having 2 to 10 C atoms, wherein one or more hydrogen atoms in the radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S; and

[0089] R 3 represents, identically or differently on each occurrence, alkyl having 1 to 10 C atoms, in which one or more hydrogen atoms may be replaced by F or Cl and in which one or more CH2 groups may be replaced by O or S;

[0090] Z 11 is selected, identically or differently at each occurrence, from -CO-O-, -O-CO-, -CF2-CF2-, -CF2-O-, -O-CF2-, -CH2-CH2-, -CH=CH-, -CF=CF-, -CF=CH-, -CH=CF-, -C≡C-, -OCH2-, -CH2O-, and a single bond; and

[0091] A 11 are selected identically or differently on each occurrence from the following groups

[0092]

[0093]

[0094] in

[0095] Y is selected, identically or differently on each occurrence, from F, Cl, CN, and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S.

[0096] R 11 , R 12 It preferably represents, identically or differently on each occurrence, alkyl having 1 to 10 C atoms.

[0097] Z 11 It is preferably selected identically or differently on each occurrence from the group consisting of -CO-O-, -O-CO- and a single bond.

[0098] A 11 Preferably, the same or different ones are selected on each occurrence from

[0099]

[0100] in

[0101] Y is as defined above and is preferably equal to F or CN.

[0102] Particularly preferred compounds of formula (F-1) correspond to the following formula

[0103]

[0104]

[0105] wherein Y is as defined above and is preferably equal to F.

[0106] The liquid-crystalline material preferably contains the compound of the formula (F-1) in a total fraction of 0% to 30% by weight, particularly preferably 5% to 25% by weight, very particularly preferably 10% to 20% by weight.

[0107] Preferably, the liquid crystal material comprises at least one compound V having units of the formula (E-2) and at least one compound of the formula (F-1). Preferably, the liquid crystal material comprises a total fraction of at least 10% by weight, particularly preferably at least 20% by weight, very particularly preferably at least 30% by weight, more preferably at least 40% by weight, most preferably at least 50% by weight of the compounds selected from the group consisting of the compound V having units of the formula (E-2) and the compound of the formula (F-1).

[0108] It is also preferred that the liquid crystal material comprises one or more compounds corresponding to formula (F-2)

[0109] in

[0110] R 21 The definition of R is as above 11 ;

[0111] R 22 The definition of R is as above 12 ;

[0112] Z 21 The definition of Z is as above 11 ;and

[0113] A 21 The definition of A is as above 11 .

[0114] R 21 , R 22 Preferably, identically or differently on each occurrence, it represents alkyl having 1 to 10 C atoms or alkoxy having 1 to 10 C atoms.

[0115] Z 21 Preferred is a single bond.

[0116] A 21 Preferably, the same or different ones are selected on each occurrence from

[0117]

[0118] Particularly preferred compounds of formula (F-2) correspond to the following formulae (F-2-1) and (F-2-2)

[0119]

[0120] The liquid-crystalline material preferably contains the compounds of the formula (F-2) in a total fraction of 0% to 30% by weight, particularly preferably 3% to 20% by weight, very particularly preferably 5% to 15% by weight.

[0121] According to the invention it is preferred that the liquid crystal material according to the invention contains one or more chiral dopants. In this case it is preferred that the molecules of the liquid crystal material are present in the layer of the device according to the invention twisted relative to one another, particularly preferably as known from the TN mode of displays.

[0122] According to an alternative embodiment which is also preferred, the liquid crystal material according to the invention does not contain a chiral dopant. In this case, preferably, the molecules of the liquid crystal material are present in the guest-host liquid crystal device without being twisted relative to one another. In this case, it is particularly preferred that the liquid crystal device is present in antiparallel mode.

[0123] In the liquid crystal material according to the invention, the chiral dopant is preferably used in a total concentration of 0.01 to 3% by weight, particularly preferably 0.05 to 1% by weight. In order to obtain high twist values, the total concentration of the chiral dopant can also be higher than 3% by weight, preferably up to 10% by weight.

[0124] When the proportions of the liquid crystal compound and the dye compound are specified, the proportions of these compounds and other minor components are not taken into consideration.

[0125] Preferred dopants are the compounds shown in the following table:

[0126]

[0127]

[0128]

[0129] The liquid crystal material according to the invention also preferably contains one or more stabilizers. The total concentration of the stabilizers is preferably between 0.00001 and 10% by weight, particularly preferably between 0.0001 and 1% by weight, based on the entire mixture.

[0130] Preferred stabilizers are shown in the table below:

[0131]

[0132]

[0133]

[0134]

[0135]

[0136] The liquid crystal material according to the present invention comprises one or more dye compounds. The dye compound is preferably an organic compound, particularly preferably an organic compound comprising at least one condensed aromatic or heteroaromatic group.

[0137] Preferably, the liquid-crystalline material according to the invention comprises at least two, particularly preferably at least three, very particularly preferably three or four different dye compounds. Preferably, the at least two dye compounds each cover a different spectral range.

[0138] When two or more dye compounds are present in the liquid crystal material according to the present invention, the absorption spectra of the dye compounds are preferably complementary so that substantially all visible spectra are absorbed. Therefore, a black impression is produced to the naked eye. This is preferably achieved by using three or more dye compounds, wherein at least one dye compound absorbs blue light, at least one dye compound absorbs green to yellow light and at least one dye compound absorbs red light. The light color is here according to B. Bahadur, Liquid Crystals-Applications and Uses, Vol. 3, 1992, World Scientific Publishing House, Chapter 11.2.1. It should be noted that the perceptible colors of the dye compounds are respectively complementary to the absorption colors, i.e., the dye compound absorbing blue light has a yellow color.

[0139] The proportion of the dye compounds in the liquid-crystal material according to the invention is preferably 0.01 to 10% by weight in total, particularly preferably 0.1 to 7% by weight, very particularly preferably 0.2 to 7% by weight. The proportion of an individual dye compound is preferably 0.01 to 10% by weight, particularly preferably 0.05 to 7% by weight, very particularly preferably 0.1 to 7% by weight.

[0140] The dye compound contained in the liquid crystal material is preferably dissolved in the liquid crystal material. The alignment of the dye compound is preferably affected by the molecular alignment of the liquid crystal material.

[0141] It is also preferred that the dye compound is a dichroic dye compound, particularly preferably a positive dichroic dye compound. Positive dichroism is understood to mean that the dye compound has a positive anisotropy R as determined in the manner given in the examples. Particularly preferably, the positive anisotropy R is greater than 0.4, very particularly preferably greater than 0.5, most preferably greater than 0.6.

[0142] Preferably, the absorption of the dye compound reaches a maximum when the polarization direction of light is parallel to the direction of the longest dimension of the molecules of the dye compound, and reaches a minimum when the polarization direction of light is perpendicular to the direction of the longest dimension of the molecules of the dye compound.

[0143] It is also preferred that the dye compound according to the present application absorbs mainly light in the UV-VIS-NIR range, ie in the wavelength range from 320 to 2000 nm.

[0144] It is also preferred that the dye compound is a fluorescent dye compound. In this context, fluorescence is understood to mean that the compound enters an electronically excited state by absorbing light of a certain wavelength, wherein the compound subsequently converts to the ground state by emitting light. Preferably, the emitted light has a longer wavelength than the absorbed light. It is also preferred that the transition from the excited state to the ground state is spin-permitting, i.e. the transition is performed without spin change. It is also preferred that the lifetime of the excited state of the fluorescent compound is shorter than 10 -5 s, particularly preferably shorter than 10-6 s, very particularly preferably 10 -9 and 10 -7 Between s.

[0145] Also preferably, the dye compound is selected from the classes of dyes given in B. Bahadur, Liquid Crystals—Applications and Uses, Vol. 3, 1992, World Scientific Publishing, Chapter 11.2.1, particularly preferably from the explicit compounds listed in the table.

[0146] Preferably, the dye compound is selected from azo compounds, anthraquinones, methine compounds, azomethine compounds, merocyanine compounds, naphthoquinones, tetrazines, perylenes, teracenes, quateracenes, higher rylenes, benzothiadiazoles, pyrrolemethines and diketopyrrolopyrroles. Particularly preferred are perylenes, benzothiadiazoles and diketopyrrolopyrroles.

[0147] Such dye compounds are extensively described in the literature. Anthraquinone dyes are described, for example, in EP 34832, EP 44893, EP 48583, EP 54217, EP 56492, EP 59036, GB 2065158, GB 2065695, GB 2081736, GB 2082196, GB 2094822, GB 2094825, JP-OS 55-123673, DE 3017877, DE 3040102, DE 3115147, DE 3115762, DE 3150803 and DE 3201120, naphthoquinone dyes are described in DE 3126108 and DE 3202761, azo dyes are described in EP 43904, DE 3123519, WO 82 / 2054, GB 2079770, JP-OS 56-57850, JP-OS 56-104984, US 4308161, US 4308162, US 4340973, T. Uchida, C. Shishido, H. Seki and M. Wada: Mol. Cryst. Lig. Cryst. 39, 39-52 (1977) and H. Seki, C. Shishido, S. Yasui and T. Uchida: Jpn. J. Appl. Phys. 21, 191-192 (1982), perylene is described in EP 60895, EP 68427 and WO 82 / 1191.

[0148] Particularly preferred are anthraquinone dyes, azo dyes and naphthoquinone dyes such as are disclosed in detail in DE 3307238, and rylene dyes such as are disclosed in EP 2166040, US 2011 / 0042651, EP 68427, EP 47027, EP 60895, DE 3110960 and EP698649, and benzothiadiazole dyes such as are disclosed in the as yet unpublished application EP13002711.3.

[0149] Examples of preferred dyes are shown in the table below:

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156]

[0157]

[0158]

[0159]

[0160]

[0161] Another subject of the present invention is the use of a liquid-crystalline material comprising a dye compound in a device for regulating light transmission, wherein the liquid-crystalline material has a clearing point of at least 95° C. and comprises at least one compound V comprising at least one unit selected from the group consisting of units of formulae (E-1), (E-2) and (E-3).

[0162] The preferred embodiments of compound V and the further preferred embodiments given above for the liquid-crystalline material according to the invention are likewise preferred here.

[0163] The liquid crystal material is present in the device in the form of a layer. The layer is preferably switchable, ie a switching layer.

[0164] The device according to the invention is preferably suitable for regulating the transmission of light in the form of natural light from the environment into a room. Here, the light to be regulated is transmitted from the environment (outdoors) into the room. Here, the room can be any room that is essentially isolated from the environment, such as a building, an aircraft or a container. In general, the device can be used in any room, in particular when the room has only a limited air exchange with the environment and has a light-transmitting interface through which energy can be input from the outside in the form of light energy. Particularly relevant is the use of the device for rooms that are exposed to strong solar radiation due to light-transmitting surfaces (for example due to window surfaces).

[0165] The device according to the invention is preferably arranged in an opening of a larger planar structure, wherein the planar structure itself does not allow light to pass through or only allows a small amount of light to pass through, and wherein the opening is relatively more transparent to light. Preferably, the planar structure is a wall or other boundary of the chamber facing outwards. Preferably, the device according to the invention is characterized in that the device has a width of at least 0.05 m 2 , preferably at least 0.1 m 2 , particularly preferably at least 0.5 m 2 , very particularly preferably at least 0.8 m 2 Area size.

[0166] The device according to the invention is switchable. Switching is understood here to mean a change in the light transmission through the device. The device according to the invention is preferably switchable electrically controllably.

[0167] If the device is electrically switchable, it preferably comprises two or more electrodes, which are attached to both sides of the switching layer comprising the liquid crystal material. The electrodes preferably consist of ITO or of a thin, preferably transparent metal layer and / or metal oxide layer, such as silver or FTO (fluorine-doped zinc oxide) or alternative materials known to the person skilled in the art for this purpose. The electrodes are preferably provided with electrical connections. The voltage is preferably provided by a battery, an accumulator or by an external power supply.

[0168] In the case of electrical switching, the switching process is performed by applying a voltage to align the molecules of the liquid crystal material.

[0169] In a preferred embodiment, the device is switched from a state with high absorption (i.e. low light transmittance) in the absence of voltage to a state with lower absorption (i.e. higher light transmittance) by applying a voltage. Preferably, the liquid crystal material in the layer of the device is nematic in both states. The absence of voltage state is preferably characterized in that the molecules of the liquid crystal material and therefore the molecules of the dye compound are present in a manner parallel to the plane of the switching layer. This is preferably achieved by a correspondingly selected orientation layer. The voltage state is preferably characterized in that the molecules of the liquid crystal material and therefore the molecules of the dye compound are present perpendicular to the plane of the switching layer.

[0170] In an alternative embodiment to the above, the device is converted from a state with low absorption (i.e. high light transmittance) in a voltage-free form to a state with higher absorption (i.e. lower light transmittance) by applying a voltage. Preferably, the liquid crystal material in the layer of the device is nematic in both states. The voltage-free state is preferably characterized in that the molecules of the liquid crystal material and therefore the molecules of the dye compound are present in a manner perpendicular to the plane of the switching layer. This is preferably achieved by a correspondingly selected orientation layer. The voltage-existing state is preferably characterized in that the molecules of the liquid crystal material and therefore the molecules of the dye compound are present parallel to the plane of the switching layer.

[0171] According to a preferred embodiment of the present invention, the device can be operated without external power supply, wherein the required energy is provided by a solar cell combined with the device or other devices that convert light energy and / or heat energy into electrical energy. Providing energy by solar cells can be done directly or indirectly (i.e., by a battery or storage battery connected therebetween or other units for storing energy). Preferably, the solar cell is mounted on the outside of the device or is an internal component of the device, such as disclosed in WO 2009 / 141295. Particularly preferred are solar cells that are particularly effective under diffuse light and transparent solar cells.

[0172] The device according to the invention preferably has the following layer sequence, wherein further layers may additionally be present. Preferably, the layers specified below directly adjoin one another in the device.

[0173] - A substrate layer preferably made of glass or polymer

[0174] - Conductive transparent layer preferably made of ITO

[0175] - Orientation layer

[0176] -Switching layer containing liquid crystal material

[0177] - Orientation layer

[0178] - Conductive transparent layer preferably made of ITO

[0179] - A substrate layer preferably made of glass or a polymer.

[0180] Preferred embodiments of the various layers are described below.

[0181] Preferably, the device according to the invention comprises one or more, particularly preferably two, orientation layers. The orientation layers preferably directly adjoin the layer comprising liquid crystal material on both sides.

[0182] As an orientation layer for the device according to the present invention, any layer known to those skilled in the art can be used. Preferred is a polyimide layer, particularly preferably a layer of rubbed polyimide. When the molecules are present parallel to the orientation layer (planar alignment), the polyimide rubbed in a certain manner known to those skilled in the art causes the alignment of the molecules of the liquid crystal material in the rubbing direction. It is preferred that the molecules of the liquid crystal material are not completely plane-parallel to the orientation layer, but have a small tilt angle (pretilt). In order to achieve a vertical alignment of the compounds of the liquid crystal material relative to the surface of the orientation layer (homeotropic alignment), it is preferred to use a polyimide treated in a certain manner as the material of the orientation layer (polyimide for extremely high pretilt angles). It is also possible to use a polymer obtained by exposure to polarized light as an orientation layer to achieve the alignment of the compounds of the liquid crystal material according to the orientation axis (photoalignment).

[0183] Also preferably, in the device according to the invention the layer comprising the liquid crystal material is arranged between or surrounded by two substrate layers.The substrate layers may for example consist of glass or a polymer, preferably a light-transmitting polymer.

[0184] The device is preferably characterized in that it comprises no polymer-based polarizer, particularly preferably no polarizer present in a solid material phase, very particularly preferably no polarizer at all.

[0185] According to an alternative embodiment, however, the device may also comprise one or more polarisers. In this case the polarisers are preferably linear polarisers.

[0186] When exactly one polariser is present, its absorption direction is preferably perpendicular to the orientation axis of the compounds of the liquid-crystalline material of the device according to the invention on that side of the switching layer where the polariser is present.

[0187] In the device according to the present invention, not only absorptive polarizers but also reflective polarizers can be used. Preferably, a polarizer in the form of an optical film is used. Examples of reflective polarizers that can be used in the device according to the present invention are DRPF- (diffuse reflective polarizing film, 3M), DBEF- (double brightness enhancement film, 3M), DBR- (Bragg reflector of layered polymer distribution, as described in US 7,038,745 and US 6,099,758) and APF- film (improved polarizing film, 3M, with reference to Technical Digest SID 2006, 45.1, US 2011 / 0043732 and US 7023602). A polarizer (WGP, wire grid polarizer) based on reflective infrared rays of wire grid can also be used. Examples of absorptive polarizers that can be used in the device according to the present invention are Itos XP38- polarizing film and Nitto Denko GU-1220DUN- polarizing film. One example of a circular polarizer that can be used according to the present invention is polarizer APNCP37-035-STD (American Polarizer). Another example is polarizer CP42 (ITOS).

[0188] Also preferably, the device according to the invention comprises a light-conducting system, which conducts light to a solar cell or other device for converting light energy and / or heat energy into electrical energy, preferably as described in WO 2009 / 141295. The light-conducting system collects and concentrates the light that hits the device. Preferably, the light emitted by the dye compound is collected and concentrated. The light-conducting system is in contact with the device for converting light energy into electrical energy, preferably a solar cell, so as to concentrate all the light that hits the device. In a preferred embodiment of the invention, the device for converting light energy into electrical energy is mounted on the edge of the device, integrated into the device and electrically connected to the device for electrical switching of the device of the invention.

[0189] In a preferred embodiment, the device according to the invention is a window, particularly preferably a window comprising at least one glass pane, very particularly preferably an assembly of windows comprising a plurality of insulating glass panes.

[0190] A window is here understood to be a structure in a building, which comprises a frame and at least one glass pane surrounded by the frame. Preferably, the structure comprises an insulating frame and two or more glass panes (multi-pane insulating glass).

[0191] According to a preferred embodiment, the device according to the invention is applied directly on the glass surface of a window, particularly preferably in the intermediate space between two glass panes of a multi-pane insulating glass.

[0192] A window comprising a device according to the invention, in particular having the preferred features described above, is another subject of the invention. DETAILED DESCRIPTION

[0193] The present invention also relates to the following embodiments:

[0194] Embodiment 1. A device for adjusting light transmission, characterized in that the device has a layer comprising a liquid crystal material, the liquid crystal material comprising a dye compound, wherein the liquid crystal material has a clearing point of at least 95° C. and comprises at least one compound V, wherein the compound V comprises at least one unit selected from the group consisting of units of formula (E-1), (E-2) and (E-3)

[0195]

[0196] in

[0197] X is, at each occurrence, identically or differently, selected from F, Cl, Br, I, -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, and N3;

[0198] W is, at each occurrence, identically or differently, selected from F, Cl, Br, I, -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, and N3;

[0199] U is selected, identically or differently at each occurrence, from H, F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, N3 and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S;

[0200] The dashed line represents the remaining portion bound to the compound.

[0201] And at least one group U in each unit of formula (E-3) is selected from F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS and N3.

[0202] Embodiment 2. The apparatus according to embodiment 1, characterized in that X is selected from F and -CN, identically or differently at each occurrence.

[0203] Embodiment 3. The device according to embodiment 1 or 2 is characterized in that W is equal to -CN.

[0204] Embodiment 4. The apparatus according to any one or more of embodiments 1 to 3, characterized in that U is selected from H, F and -CN, the same or different at each occurrence.

[0205] Embodiment 5. The device according to any one or more of embodiments 1 to 4, characterized in that compound V comprises exactly one unit selected from the group consisting of units of formulae (E-1), (E-2) and (E-3).

[0206] Embodiment 6. The device according to any one or more of Embodiments 1 to 5, characterized in that compound V has a structure according to the following formula

[0207]

[0208] in

[0209] R V1 , R V2 represents, identically or differently on each occurrence, alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms, wherein one or more hydrogen atoms in the abovementioned radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S;

[0210] are selected identically or differently on each occurrence from the following groups

[0211] or a unit of formula (E-1), (E-2) or (E-3);

[0212] Y is selected, identically or differently on each occurrence, from F, Cl, CN and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S;

[0213] n is equal to 1, 2 or 3; and

[0214] At least one group A unit selected from formula (E-1), (E-2) or (E-3).

[0215] Embodiment 7. The device according to embodiment 6, characterized in that the compound of formula (V) contains exactly one unit selected from the units of formula (E-1), (E-2) and (E-3).

[0216] Embodiment 8. The device according to embodiment 6 or 7 is characterized in that the index n in formula (V) is equal to 1 or 2.

[0217] Embodiment 9. The device according to any one or more of Embodiments 6 to 8, characterized in that A in formula (V) V1In each occurrence, the same or different selection is made from and units of formula (E-1-1a), (E-1-2a), (E-1-3a), (E-2-1) and (E-3-1).

[0218] Embodiment 10. The device according to any one or more of embodiments 1 to 9, characterized in that the liquid crystal material has a clearing point of at least 100°C.

[0219] Embodiment 11. A device according to any one or more of embodiments 1 to 10, characterized in that the liquid crystal material has a dielectric anisotropy Δε of -2 to -10.

[0220] Embodiment 12. The device according to any one or more of embodiments 1 to 11, characterized in that the liquid crystal material contains 5 to 15 compounds V, each with a different structure.

[0221] Embodiment 13. The device according to any one or more of embodiments 1 to 12, characterized in that the liquid-crystalline material has a total content of compound V of at least 40% by weight.

[0222] Embodiment 14. The device according to any one or more of embodiments 1 to 13, characterized in that the liquid crystal material comprises one or more compounds corresponding to formula (F-1)

[0223]

[0224] in

[0225] R 11 , R 12 represents F, Cl, -CN, -NCS, -SCN, R, etc., identically or differently on each occurrence 3 -O-CO-, R 3 -CO-O- or an alkyl or alkoxy radical having 1 to 10 C atoms or an alkenyl or alkenyloxy radical having 2 to 10 C atoms, wherein one or more hydrogen atoms in the radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S; and

[0226] R 3 represents, identically or differently on each occurrence, alkyl having 1 to 10 C atoms, in which one or more hydrogen atoms may be replaced by F or Cl and in which one or more CH2 groups may be replaced by O or S;

[0227] Z 11is selected, identically or differently at each occurrence, from -CO-O-, -O-CO-, -CF2-CF2-, -CF2-O-, -O-CF2-, -CH2-CH2-, -CH=CH-, -CF=CF-, -CF=CH-, -CH=CF-, -C≡C-, -OCH2-, -CH2O-, and a single bond; and

[0228] A 11 are selected identically or differently on each occurrence from the following groups

[0229]

[0230]

[0231] in

[0232] Y is selected, identically or differently on each occurrence, from F, Cl, CN and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S.

[0233] Embodiment 15. A device according to any one or more of embodiments 1 to 14, characterized in that the liquid crystal material contains a compound selected from compound V having at least one unit of formula (E-2) and a compound of formula (F-1) in a total proportion of at least 10% by weight.

[0234] Embodiment 16. The device according to any one or more of embodiments 1 to 15, characterized in that the liquid crystal material comprises one or more compounds corresponding to formula (F-2)

[0235]

[0236] in

[0237] R 21 Definition and implementation scheme 14 of R 11 same;

[0238] R 22 Definition and implementation scheme 14 of R 12 same;

[0239] Z 21 Definition and implementation plan 14 of Z 11 are the same; and

[0240] A 21 Definition and implementation plan 14 in A 11 same.

[0241] Embodiment 17. A device according to any one or more of embodiments 1 to 16, characterized in that the liquid crystal material contains at least three different dye compounds.

[0242] Embodiment 18. The apparatus according to any one or more of embodiments 1 to 17, characterized in that the anisotropy R of the dye compound is greater than 0.4.

[0243] Embodiment 19. The apparatus according to any one or more of embodiments 1 to 18, characterized in that the dye compound is selected from azo compounds, anthraquinones, methine compounds, imine compounds, merocyanine compounds, naphthoquinones, tetrazines, perylenes, teracenes, quartacenes, higher naphthylenes, benzothiadiazoles, pyrromethenes and diketopyrrolopyrroles.

[0244] Embodiment 20. The device according to any one or more of embodiments 1 to 19, characterized in that the device is suitable for regulating the transmission of light in the form of natural light from the environment into the room.

[0245] Embodiment 21. The device according to any one or more of embodiments 1 to 20, characterized in that the device has at least 0.5m 2 Area size.

[0246] Embodiment 22. The device according to any one or more of embodiments 1 to 21 is characterized in that the device can be switched electrically.

[0247] Embodiment 23. The device according to any one or more of embodiments 1 to 22, characterized in that the device has the following layer sequence, wherein further layers may be additionally present:

[0248] -Base material layer

[0249] -Conductive transparent layer

[0250] - Orientation layer

[0251] -Switching layer containing liquid crystal material

[0252] - Orientation layer

[0253] -Conductive transparent layer

[0254] -Substrate layer.

[0255] Embodiment 24. The device according to any one or more of Embodiments 1 to 23, characterized in that the device does not include a polarizer.

[0256] Embodiment 25. A window comprising an apparatus according to any one or more of Embodiments 1 to 24.

[0257] Embodiment 26. Use of a liquid crystal material in a device for adjusting light transmission, wherein the liquid crystal material comprises a dye compound, wherein the liquid crystal material has a clearing point of at least 95°C and comprises at least one compound V, wherein the compound V comprises at least one unit selected from the units of formula (E-1), (E-2) and (E-3) as defined in Embodiment 1.

[0258] Example

[0259] A) Preparation of Liquid Crystal Mixture

[0260] Two comparative mixtures V1 and V2 were prepared. Liquid-crystal mixtures E1 to E10 according to the present application were also prepared.

[0261] The compositions of mixtures V1, V2 and E1-E10 are given below. The chemical structures of the individual components of the mixtures are reproduced here by abbreviations (acronyms). The abbreviations are clearly stated and explained in WO 2012 / 052100 (pages 63-89), so reference is made to the application for explanation.

[0262] The following suffixes do not correspond to the so-called nomenclature, so that the corresponding chemical structures are shown explicitly.

[0263]

[0264]

[0265] The clearing point, the optical anisotropy Δn and the dielectric anisotropy Δε of the mixtures are given in degrees Celsius. The physical properties were determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals" (status November 1997, Merck KGaA, Germany) and apply to a temperature of 20° C. The values ​​for Δn were determined at 589 nm, the values ​​for Δε at 1 kHz.

[0266] The low temperature stability was determined in vials and in test cells approximately 6 micrometers thick at room temperature (+20° C.) and at temperatures of −20° C., −30° C. and −40° C., respectively.

[0267] The samples were visually checked at 24 h intervals for the development of crystals or smectic phases. As long as no crystals or smectic phases were observed in either the bottle or the test box at the stated temperature, the test continued.

[0268] As soon as a crystal or smectic phase was observed in a sample, the test was terminated and the number of days reached was counted as low temperature stability.

[0269]

[0270]

[0271]

[0272]

[0273]

[0274]

[0275]

[0276]

[0277]

[0278]

[0279] B) Preparation of liquid crystal mixtures containing dyes and determination of their physical properties

[0280] In all mixtures E1 to E10 shown in A), mixtures were prepared comprising one or more dyes. Representative selected results are shown below.

[0281] B-1) Preparation of mixtures containing dye F1 and determination of anisotropy and solubility

[0282] A mixture was prepared which contained the dye F1 in one of the liquid-crystal mixtures V1, E1, E2, E3 and E7 (composition see table below).

[0283]

[0284] Dye F1

[0285] The anisotropy R is determined by the value of the extinction coefficient E(p) (extinction coefficient of the mixture in the case where the molecules are aligned parallel to the polarization direction of the light) and the value of the extinction coefficient E(s) of the mixture (extinction coefficient of the mixture in the case where the molecules are aligned perpendicular to the polarization direction of the light) at the wavelength of the peak of the absorption band of the relevant dye. If the dye has multiple absorption bands, the absorption band with the longest wavelength is selected. The alignment of the molecules of the mixture is achieved by an orientation layer, as known to those skilled in the art of liquid crystal devices. In order to eliminate the influence caused by the liquid crystal medium, other absorption and / or reflection, the measurements are respectively carried out relative to the same mixture without the dye and the obtained values ​​are subtracted.

[0286] The measurement is performed using linearly polarized light, the vibration direction of which is parallel to the orientation direction (determination of E(p)) or perpendicular to the orientation direction (determination of E(s)). This can be achieved by a linear polarizer, which is twisted relative to the device so that two different vibration directions are achieved. The measurement of E(p) and E(s) is performed by twisting the vibration direction of the incident polarized light. Alternatively, the sample can also be twisted relative to the spatially fixed polarization direction of the incident polarized light.

[0287] The anisotropy R is calculated from the resulting values ​​of E(s) and E(p) according to the formula R=[E(p)-E(s)] / [E(p)+2*E(s)], as described in particular in "Polarized Light in Optics and Spectroscopy" (DS Kliger et al., Academic Press, 1990). For a detailed description of the method for determining the anisotropy of liquid-crystalline media containing dichroic dyes, see B. Bahadur, Liquid Crystals-Applications and Uses, Volume 3, 1992, World Scientific Publishing, Chapter 11.4.2.

[0288] The method was used in the same manner in all the following examples.

[0289] Liquid crystal mixture dye Dye concentration Maximum absorption wavelength Anisotropy V1(Comparison) F1 0.25 wt% 504nm 0.73 E1 F1 0.25 wt% 507nm 0.74 E2 F1 0.25 wt% 507nm 0.75 E3 F1 0.25 wt% 506nm 0.75 E7 F1 0.25 wt% 505nm 0.77

[0290] The results show that the anisotropy of the mixture according to the invention is higher than that of the comparative mixture.

[0291] The solubility of dye F1 in different liquid crystal mixtures at +20°C and -20°C was also studied.

[0292] Liquid crystal mixture dye temperature Maximum solubility (observed after 1 week) V1(Comparison) F1 +20℃ 1.4 wt% V1(Comparison) F1 -20℃ 0.9 wt% E1 F1 +20℃ 1.4 wt% E1 F1 -20℃ 3.3 wt% E2 F1 +20℃ 4 wt% E2 F1 -20℃ 4 wt% E7 F1 +20℃ 1.3 wt% E7 F1 -20℃ 3.3 wt%

[0293] It was found here that the solubility in the mixture according to the invention was significantly higher than in the comparative mixture.

[0294] B-2) Preparation of the mixture comprising dye F2 and determination of the anisotropy and solubility procedures are as described in B-1).

[0295]

[0296] Dye F2

[0297]

[0298]

[0299] The results show that improved solubility and comparable anisotropy are achieved with the liquid-crystal mixtures according to the invention.

[0300] B-3) Preparation of the mixture comprising dye F3 and determination of the anisotropy and solubility procedures are as described in B-1).

[0301]

[0302] Dye F3

[0303]

[0304]

[0305] The results show that improved solubility and comparable anisotropy are achieved with the liquid-crystal mixtures according to the invention.

[0306] B-4) Preparation of the mixture comprising dye F4 and determination of the anisotropy and solubility procedures are as described in B-1).

[0307]

[0308] Dye F4

[0309]

[0310]

[0311] The results show that comparable or better degrees of anisotropy are achieved with the liquid-crystal mixtures according to the invention than with the comparative mixture V1.

[0312] B-5) Preparation of the mixture comprising dye F5 and determination of the anisotropy and solubility procedures are as described in B-1).

[0313]

[0314] Dye F5

[0315] Liquid crystal mixture dye Dye concentration Maximum absorption wavelength Anisotropy V1(Comparison) F5 0.25 wt% 539nm 0.80 E3 F5 0.25 wt% 545nm 0.80 E7 F5 0.25 wt% 543nm 0.81

[0316] For dye F5, the mixture according to the invention exhibits a degree of anisotropy that is as good as or better than that of comparative mixture V1.

[0317] B-6) Preparation of the mixture comprising dye F6 and determination of the anisotropy and solubility procedures are as described in B-1).

[0318]

[0319] Dye F6

[0320] Liquid crystal mixture dye Dye concentration Maximum absorption wavelength Anisotropy V1(Comparison) F6 0.25 wt% 447nm 0.81 E3 F6 0.25 wt% 453nm 0.81 E7 F6 0.25 wt% 451nm 0.81

[0321] The examples show that, for dye F6, the mixture according to the invention has a degree of anisotropy similar to that of comparative mixture V1.

[0322] Comparative mixture V2 gave a similar degree of anisotropy and solubility of the dye as comparative mixture V1.

[0323] The above examples show that liquid crystal mixtures with different dyes can be prepared with the compounds according to the invention. The mixtures obtained are characterized by high anisotropy and high solubility of the dye compounds and high solution stability and are therefore particularly suitable for use in devices for regulating light transmission.

[0324] C) Use of the mixture E7 according to the invention in a device for regulating the light transmission

[0325] C-1) A mixture of the liquid crystal mixture E7 and the dyes F1 (0.10% by weight), F2 (0.23% by weight), F7 (0.09% by weight) and F8 (0.33% by weight) was prepared.

[0326]

[0327] Dye F7

[0328]

[0329] Dye F8

[0330] The anisotropy of the mixture was determined according to the above method. In a wide range of light wavelengths from 430 nm to 630 nm, the anisotropy was 0.8.

[0331] Liquid crystal material containing dye is filled into a device for adjusting light transmission. The device has the following layer sequence:

[0332] -Glass substrate layer

[0333] -ITO conductive transparent layer, 200 angstroms

[0334] -Antiparallel rubbed polyimide alignment layer

[0335] -Switching layer containing liquid crystal material, 24.4 μm

[0336] -Polyimide orientation layer

[0337] -ITO conductive transparent layer

[0338] -Glass substrate layer

[0339] In this arrangement, the liquid crystal material is oriented flat with an anti-parallel pre-tilt angle. The orientation is achieved by polyimide layers rubbed anti-parallel to each other. The thickness of the liquid crystal layer is controlled by spacers. The ITO layer is electrically contacted so that a voltage can be applied to the switching layer containing the liquid crystal material.

[0340] By applying a voltage, the device can be switched color-neutral between a dark state (no voltage) and a light state (voltage applied). The color impression is gray in this case.

[0341] For the device in both switching states, the light transmittance τ is obtained as ν Values:

[0342] τ ν亮态 =84%

[0343] τ ν暗态 =49%.

[0344] The light transmittance τ is calculated according to the European standard EN410 equation (1) (Optical technology and determination of radiation physical characteristic values ​​of glass). ν亮态 and τ ν暗态 According to the standard light transmittance τ ν The relative spectral distribution of standard light and the spectral brightness sensitivity of a standard observer are taken into account.

[0345] Another device according to the invention was prepared, comprising two switching layers, as described in the embodiments of the as yet unpublished application EP13002445.8. The device had the following layer arrangement:

[0346] -Glass layer

[0347] -ITO layer, 200 angstroms

[0348] -Antiparallel rubbed polyimide alignment layer

[0349] -Switching layer containing liquid crystal material, 24.4 μm

[0350] -Antiparallel rubbed polyimide alignment layer

[0351] -ITO layer, 200 angstroms

[0352] -Glass layer

[0353] The above-mentioned layer sequence of 7 layers is twisted by 90° relative to itself about an axis running perpendicularly through the layers.

[0354] For the device in both switching states, the light transmittance τ is obtained as ν Values:

[0355] τ ν亮态 =71%

[0356] τ ν暗态 =11%.

[0357] C-2) A mixture of the liquid crystal mixture E7 and the dyes F1 (0.103% by weight), F8 (0.287% by weight), F9 (0.101% by weight) and F10 (0.518% by weight) was prepared.

[0358]

[0359] Dye F9

[0360]

[0361] Dye F10

[0362] As described above under 1), a device for regulating light transmission having a single switching layer is produced using the mixture.

[0363] For the device in both switching states, the light transmittance τ is obtained as ν Values:

[0364] τ ν亮态 =81%

[0365] τ ν暗态 =47%.

[0366] As described above in 1), the mixture is also used to prepare a device for regulating light transmission having a double switching layer.

[0367] For the device in both switching states, the light transmittance τ is obtained as ν Values:

[0368] τ ν亮态 =66%

[0369] τ ν暗态 =10%.

[0370] C-3) A mixture of the liquid crystal mixture E7 and the dyes F1 (0.048% by weight), F8 (0.223% by weight), F9 (0.116% by weight) and F11 (0.679% by weight) was prepared.

[0371]

[0372] Dye F11

[0373] As described above under 1), a device for regulating light transmission having a single switching layer is produced using the mixture.

[0374] For the device in both switching states, the light transmittance τ is obtained asν Values:

[0375] τ ν亮态 =82%

[0376] τ ν暗态 =48%.

[0377] As described above in 1), the mixture is also used to prepare a device for regulating light transmission having a double switching layer.

[0378] For the device in both switching states, the light transmittance τ is obtained as ν Values:

[0379] τ ν亮态 =68%

[0380] τ ν暗态 =12%.

Claims

1. A window comprising a device suitable for regulating the transmission of light in the form of natural light from the environment to the interior of the room, characterized in that The device comprises a layer comprising a liquid crystal material, the liquid crystal material comprising at least three different dye compounds selected from the group consisting of perylene, benzothiadiazole and diketopyrrolopyrrole, wherein the liquid crystal material has a clearing point of at least 105° C. and comprises a total content of at least 40% by weight of at least one compound V, the compound V comprising at least one unit selected from the group consisting of units of the formulae (E-1), (E-2) and (E-3) in X is, at each occurrence, identically or differently, selected from F, Cl, Br, I, -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, and N3; W is, at each occurrence, identically or differently, selected from F, Cl, Br, I, -CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, and N3; U is selected, identically or differently at each occurrence, from H, F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS, N3 and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S; The dashed lines represent the bonds to the rest of the compound. and at least one group U in each unit of formula (E-3) is selected from F, Cl, Br, I, CN, -NCO, -NCS, -SCN, -OCN, -NC, -CNO, -CNS and N3; Furthermore, the liquid crystal material contains at least one compound of the formula (F-1-2) in a total proportion of 5% by weight to 25% by weight in R 11 , R 12 represents F, Cl, -CN, -NCS, -SCN, R, etc., identically or differently on each occurrence 3 -O-CO-, R 3 -CO-O- or an alkyl or alkoxy radical having 1 to 10 C atoms or an alkenyl or alkenyloxy radical having 2 to 10 C atoms, wherein one or more hydrogen atoms in the radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S; and R 3 represents, identically or differently on each occurrence, alkyl having 1 to 10 C atoms, in which one or more hydrogen atoms may be replaced by F or Cl and in which one or more CH2 groups may be replaced by O or S; In addition, the liquid crystal material comprises one or more compounds of formula (F-1-1) in Y is F; and Where R 11 and R 12 is an alkyl group having 1 to 10 C atoms; The liquid crystal material has a dielectric anisotropy Δε of -2 to -7; The window has a width of at least 0.5 m 2 Area size.

2. The window according to claim 1, characterized in that The liquid crystal material contains one or more compounds of the formula (F-1-1) in a total proportion of 5% to 25% by weight.

3. The window according to claim 2, characterized in that X is identically or differently selected at each occurrence from F and -CN.

4. The window according to claim 2 or 3, characterized in that: W equals -CN.

5. The window according to claim 2 or 3, characterized in that: U is selected, identically or differently at each occurrence, from H, F and -CN.

6. The window according to claim 1 or 2, characterized in that: Compound V comprises exactly one unit selected from the group consisting of units of the formulae (E-1), (E-2) and (E-3).

7. The window according to claim 1 or 2, characterized in that: Compound V has a structure according to the formula in R V1 , R V2 represents, identically or differently on each occurrence, alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms, wherein one or more hydrogen atoms in the abovementioned radicals may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S; is selected identically or differently on each occurrence from the following groups or a unit of formula (E-1), (E-2) or (E-3); Y is selected, identically or differently on each occurrence, from F, Cl, CN and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl, and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S; n is equal to 1, 2 or 3; and At least one group A unit selected from formula (E-1), (E-2) or (E-3).

8. The window according to claim 7, characterized in that The compounds of formula (V) comprise exactly one unit selected from the group consisting of units of formulae (E-1), (E-2) and (E-3).

9. The window according to claim 7, characterized in that The index n in formula (V) is equal to 1 or 2.

10. The window according to claim 7, characterized in that A in formula (V) V1 In each occurrence, the same or different selection is made from and units of formula (E-1-1a), (E-1-2a), (E-1-3a), (E-2-1) and (E-3-1) as shown below: Wherein the dashed line represents the bond to the rest of the compound; Wherein the dashed line represents the bond to the rest of the compound; The dashed line represents the bond to the rest of the compound.

11. The window according to claim 1 or 2, characterized in that: The liquid crystal material is a nematic liquid crystal at least in the temperature range of -20°C to 100°C.

12. The window according to claim 1 or 2, characterized in that: The liquid crystal material contains 5 to 15 kinds of compounds V each having a different structure.

13. The window according to claim 1 or 2, characterized in that: The liquid-crystalline material contains compound V having at least one unit of the formula (E-2), the compound of the formula (F-1-1) and the compound of the formula (F-1-2) in a total proportion of at least 10% by weight.

14. The window according to claim 1 or 2, characterized in that: The liquid crystal material comprises one or more compounds corresponding to formula (F-2) in R 21 , R 22 represents F, Cl, -CN, -NCS, -SCN, R, etc., identically or differently on each occurrence 3 -O-CO-, R 3 -CO-O- or alkyl or alkoxy having 1 to 10 C atoms or alkenyl or alkenyloxy having 2 to 10 C atoms, wherein one or more hydrogen atoms in the above mentioned groups may be replaced by F or Cl and one or more CH2 groups may be replaced by O or S; R 3 represents, identically or differently on each occurrence, alkyl having 1 to 10 C atoms, in which one or more hydrogen atoms may be replaced by F or Cl and in which one or more CH2 groups may be replaced by O or S; Z 21 is selected, identically or differently at each occurrence, from -CO-O-, -O-CO-, -CF2-CF2-, -CF2-O-, -O-CF2-, -CH2-CH2-, -CH=CH-, -CF=CF-, -CF=CH-, -CH=CF-, -C≡C-, -OCH2-, -CH2O-, and a single bond; and A 21 is selected identically or differently on each occurrence from the following groups in Y is selected, identically or differently on each occurrence, from F, Cl, CN and alkyl, alkoxy or alkylthio having 1 to 10 C atoms, wherein one or more hydrogen atoms in the alkyl, alkoxy or alkylthio group may be replaced by F or Cl and wherein one or more CH2 groups in the alkyl, alkoxy or alkylthio group may be replaced by O or S.

15. The window according to claim 1 or 2, characterized in that: The anisotropy R of the dye compound is greater than 0.

4.

16. The window according to claim 1 or 2, characterized in that: The window has a width of at least 0.8 m 2 Area size.

17. The window according to claim 1 or 2, characterized in that: The window can be switched electrically.

18. The window according to claim 1 or 2, characterized in that: The window has the following layer sequence, where further layers may be present in addition: -Base material layer -Conductive transparent layer - Orientation layer -Switching layer containing liquid crystal material - Orientation layer -Conductive transparent layer -Substrate layer.

19. The window according to claim 1 or 2, characterized in that: The device does not include a polariser.

20. Use of a liquid crystal material in a window comprising an apparatus for regulating the transmission of light in the form of natural light from the environment into a room, the liquid crystal material comprising at least three different dye compounds selected from perylene, benzothiadiazole and diketopyrrolopyrrole, wherein the liquid crystal material has a clearing point of at least 105° C. and comprises a total fraction of at least 40% by weight of at least one compound V comprising at least one unit selected from the group consisting of units of the formulae (E-1), (E-2) and (E-3) as defined in claim 1; Furthermore, the liquid crystal material further comprises one or more compounds corresponding to the formula (F-1-2) as defined in claim 1 in a total content of 5% by weight to 25% by weight; Furthermore, the liquid crystal material comprises one or more compounds corresponding to formula (F-1-1) as defined in claim 1; The liquid crystal material has a dielectric anisotropy Δε of -2 to -7; the window has a dielectric anisotropy of at least 0.5m 2 Area size.

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