TWI600943B - Liquid-crystalline medium, temperature-reactive device for the regulation of light transmission, application thereof, and process for producing the same - Google Patents

Description

Liquid crystal medium, temperature reactive device for adjusting light transmittance, use thereof, and method for producing same

The present invention relates to a temperature-reactive device for adjusting light transmittance, which comprises a liquid crystal medium and a component (N) comprising nanoparticle and/or one or more compounds (V) having a three-dimensional structure. The invention further relates to a method of temperature dependent control of light transmission via a liquid crystal dielectric layer.

For the purposes of the present invention, the term liquid crystal medium means a material that exhibits liquid crystal properties under certain conditions. In particular, the term means a material that forms a nematic liquid crystal phase under certain conditions. The liquid crystal medium can include one or more liquid crystal compounds and other materials.

The term liquid crystal compound means a compound which exhibits liquid crystal properties under certain conditions, and specifically means a compound which forms a nematic liquid crystal phase under certain conditions.

For the purposes of this application, a temperature-reactive device means a device that assumes various states depending on the temperature. An example of this is a device that exhibits varying degrees of light transmission depending on temperature.

For the purposes of this application, the term light transmittance refers to the pass rate of electromagnetic radiation transmitted through the device in visible (VIS), near infrared (near-IR, NIR) and UV-A regions. In the present application, the term light also correspondingly refers to electromagnetic radiation in the visible, near-infrared and UV-A regions of the spectrum. According to the physical definition commonly used, UV-A light, visible light, and near-infrared light together mean radiation having a wavelength of 320 nm to 3000 nm.

For the purposes of this application, the term nanoparticle means a diameter of between 1 nm and Particles between 1 μm.

For the purposes of the present invention, the term compound having a three-dimensional structure means a compound which does not extend predominantly in a linear manner and in only one dimension (for example, a polymer or a small organic molecule, for example, sin-1,7-di Alkyne, n-decane or p-terphenyl), and additionally does not extend predominantly in a planar manner and in only two dimensions (eg, benzene or hydrazine), but instead is substantially equivalent in space Extends in all three dimensions.

Examples of such compounds based tetraphenylmethane, cubane, closo-carborane _{(e.g., C 2 B 10 H 12)} , fullerene (Fullerene) and sesqui silicon oxide. In general, molecular cage compounds as defined in the following sections are generally compounds having a three-dimensional structure as defined above. A compound having a three-dimensional structure may, for example, have a substantially spherical, cubic, tetrahedral or tapered structure.

Such compounds preferably have a length dimension _dmax and another length dimension _dmin , wherein _{dmax is} defined as the largest dimension and _{dmin is} defined as the smallest dimension, and wherein _dmin is at least 30% of the _dmax value, preferably The ground is at least 50% of the value of d _max , equally preferably at least 70% and very preferably at least 80%.

For structural structures of the compounds, such structural parameters can be determined by analog methods known to those skilled in the art. These parameters are generally sufficiently precise that a person skilled in the art can classify a compound into a compound having a three-dimensional structure according to the above definition. In addition, in particular, in the case of novel and/or lesser-known structural types, those skilled in the art may rely on structural determination by means of crystallography or spectroscopic methods.

As the energy efficiency of buildings becomes more and more important, there is a growing need for devices. The light transmission through the window or glass surface can be controlled and thus the energy flow can be controlled. In particular, there is a need in the industry for devices that are capable of adapting the flow of energy through the glass surface to the primary conditions (hot, cold, high insolation, low insolation) at a particular point in time. Of particular interest is the provision of such devices in temperate climate zones where seasonal variations occur from the warm outside temperature combined with high insolation to the cold outside temperature combined with low insolation.

The effect caused by the insolation on the glass surface in the building will be presented below. Equivalent effects may occur not only in the case of a building, but also in the case of a vehicle or shipping container (eg, a shipping container).

During warm seasons in warm temperate zones and temperate climate zones, the glass surfaces in buildings can cause undesired heating of the interior space when the insolation affects these surfaces. This is due to the fact that the radiation in the VIS or near-IR region of the electromagnetic spectrum is permeable to the glass. Objects in the interior space absorb the transmitted radiation and thus heat up, which increases the room temperature (greenhouse effect). However, this effect of the glass surface in a building is not always undesired: in the case of low external temperatures, in particular in the cold seasons of cold climate zones or temperate climate zones, the effect is caused by insolation Internal space heating can be advantageous as a result of the reduced energy requirements for space heating and thus cost savings.

Therefore, the technical goal is to provide means for adjusting the light transmission through windows or other glass surfaces. In particular, the target is to provide a device (smart window) that adjusts the transmittance to automatically adapt to the above-mentioned main conditions. Another object is to provide a device that is preferably energy efficient to operate, can be installed using the lowest possible technical work, is technically reliable and meets aesthetic requirements. May mention An example of this is followed by a highly regular switching of the device and avoiding color or pattern effects.

The prior art discloses a device that can be reversibly switched from a transparent state to a less opaque state (eg, opaque (astigmatism) or dark transparent state) after application of a voltage (eg, CMLampert et al, Solar Energy Materials & Solar Cells, 2003, 489). -499).

However, electrical switchable devices, such as those described above, have the disadvantage that they do not adapt to environmental conditions immediately and automatically. In addition, it requires electrical connections, which are related to the increased work during installation and increased maintenance requirements.

US 2009/0015902 and US 2009/0167971 disclose temperature-reactive devices comprising a liquid-crystalline medium in a layer between two polarizers. The liquid crystal medium is switched between a relatively high transmittance state and a relatively low transmittance state by a phase change from a nematic state to an isotropic state. Due to the phase change, a sudden transition occurs between the high transmittance state and the relatively low transmittance state at this time. At this time, it may happen that a high light transmittance state exists on the entire surface of the device (considering certain regions), and a low light transmittance state exists simultaneously in other adjacent regions.

In summary, it can be determined that there is a continuing need for temperature responsive devices for adjusting the transmittance of light through windows or generally light transmissive surfaces. In particular, the switching process is required to be based on an alternative principle device. Also specifically, it is desirable that the switching process does not occur abruptly but instead is a device that gradually proceeds via intermediate transmittance values.

S.-C. Jeng et al., Optics Letters 2009, 34, 455-457 discloses that certain liquid crystal compounds are in polyhedral oligomeric sesquioxanes (sesquioxanes, PSS) is spontaneously vertical (vertically) aligned. The degree of vertical alignment can be influenced here by the concentration of sesquioxanes. Further, it is disclosed that a mixture including a liquid crystal compound and a sesquiterpene oxide is used in an LC display based on a VA technique (VA technique = vertical alignment) in which a liquid crystal compound which is not vertically arranged is reversibly rotated by application of an electric field. Equal applications are additionally disclosed in US 2008/0198301 and S.-C. Jeng et al., Appl. Phys. Lett. 2007, 91, 0611121-0611123.

The present invention relates to the use of a liquid crystal medium in a temperature-reactive switching element comprising - one or more liquid crystal compounds and - comprising nanoparticles (and) or a component (N) of one or more compounds (V), One or more compounds (V) have a three-dimensional structure and a molecular weight of more than 450 Da.

The invention thus additionally relates to a temperature-reactive device for adjusting light transmittance, characterized in that it comprises a liquid crystal medium layer, wherein the liquid crystal medium comprises - one or more liquid crystal compounds and - comprising nanoparticles and/or one or A component (N) of a plurality of compounds (V) having a three-dimensional structure and a molecular weight of more than 450 Da.

In a preferred embodiment of the invention, the liquid crystal dielectric layer is disposed between the two substrate layers.

According to the invention, the substrate layer can be composed in particular of a polymeric material, a metal oxide (eg ITO), glass or metal composition. It preferably consists of glass or ITO. In a preferred embodiment, the substrates are arranged at an interval of at least 1 [mu]m from each other, wherein the liquid crystal dielectric layer is located in the gap. The substrate layers can be held at a defined spacing from each other by, for example, a spacer or a protruding structure in the layer.

The device may additionally have one or more alignment layers in direct contact with the liquid crystal dielectric layer. The alignment layer can also be used as a substrate layer, so that the substrate layer is not necessarily present in the device. If a substrate layer is additionally present, the alignment layer is arranged between the substrate layer and the liquid crystal dielectric layer in each case. In a preferred embodiment of the invention, the alignment layer is comprised of a rubbed polyimide. Methods of rubbing polyimine are well known to those skilled in the art and are therefore not explicitly set forth herein. In an alternate embodiment of the invention, the alignment layer consists of an unfriction polyimine. Compared to the unfriction polyimine, if the liquid crystal compound is present in a planar arrangement corresponding to the alignment layer, the friction polyimine tends to preferentially align the liquid crystal compounds in the rubbing direction.

Preferably, the device according to the invention and under certain conditions may also comprise an alignment layer adjacent to the liquid crystal dielectric layer.

In a preferred embodiment of the invention, the device has two or more polarizers, one polarizer disposed on one side of the liquid crystal dielectric layer and the other polarizer disposed on the opposite side of the liquid crystal dielectric layer. The liquid crystal dielectric layer and the polarizer here are preferably arranged in parallel to each other.

The polarizer can be a linear polarizer or a circular polarizer. Preferably, exactly two polarizers are present in the device. In this case, preferably, the polarizers are all linear polarizers or both are circular polarizers. However, in accordance with a possible embodiment of the invention, a linear polarizer can also be used with a circular polarizer.

If two linear polarizers are present in the device, it is preferred according to the invention that the two polarizers have the same polarization direction or only a small angle to each other.

Further preferably, in the case where there are two circular polarizers in the device, the circular polarizers have the same polarization direction, that is, both are right-handed circular polarizations or both are left-handed circular polarizations.

The polarizer can be a reflective or absorptive polarizer. In the sense of the present application, a reflective polarizer reflects light having one polarization direction or a type of circularly polarized light, while transmitting light having another polarization direction or another type of circularly polarized light. Accordingly, an absorbing polarizer absorbs light having one polarization direction or a type of circularly polarized light while transmitting light having another polarization direction or another type of circularly polarized light. Reflection or absorption is usually not quantitative, which means that light passing through the polarizer does not undergo full polarization.

For the purposes of the present invention, both an absorbing polarizer and a reflective polarizer can be used. It is preferred to use a polarizer in the form of a thin optical film. Examples of reflective polarizers that can be used in the apparatus of the present invention are DRPF (diffuse reflective polarizer film from 3M), DBEF (double brightness enhancement film from 3M), DBR (multilayer polymer distributed Bragg reflector, such as US 7,038,745 and US 6,099,758) and APF (Advanced Polarizer Film from 3M). In addition, a wire grid based polarizer (WGP, wire grid polarizer) that reflects infrared light can be used. Examples of absorption polarizers that can be used in the apparatus of the present invention are Itos XP38 polarizer membranes and Nitto Denko GU-1220DUN polarizer membranes. An example of a circular polarizer that can be used in the present invention is an APNCP 37-035-STD polarizer (American Polarizers). Another example is a CP42 polarizer (ITOS).

In one embodiment of the invention, the polarizer represents a substrate layer in which a liquid crystal medium is disposed, that is, no other substrate layers are present in the device.

In another preferred embodiment of the invention, the liquid crystal dielectric layer is between the flexible layers (e.g., flexible polymer film). The device of the invention is therefore flexible and bendable and can be rolled up, for example. The flexible layer can represent a substrate layer, an alignment layer, and/or a polarizer. Other layers of the same preferred flexibility may additionally be present. For a more detailed disclosure of a preferred embodiment of the liquid crystal dielectric layer between the flexible layers, see application US 2010/0045924.

In another preferred embodiment of the invention, the liquid crystal medium has a solid or gel-like consistency. The device of the invention is therefore less susceptible to damage. In addition, if only a flexible, bendable, and smable layer is present in addition to the liquid crystal dielectric layer, the device can be rolled up and the portion of the desired area can be cut in each case.

The device may additionally include a filter that blocks light of certain wavelengths, such as a UV filter. Other functional layers, such as protective films, thermal barrier films or metal oxide layers, may also be present in accordance with the present invention.

In addition, electrodes and other electrical components and connections may be present in the device of the present invention to facilitate electrical switching of the device (equivalent to switching of the LC display). However, in a preferred embodiment of the invention, there are no electrodes and other electrical components and connections.

In addition, it is generally preferred to use a device that achieves switching by temperature changes (and without applying an electric field). The preferred temperature range for the switching operation is given in the following sections.

According to the invention, component (N) comprises nanoparticles and/or one or more compounds (V) having a three-dimensional structure and a molecular weight greater than 450 Da.

According to the invention, component (N) is dissolved or dispersed in a liquid crystal medium. Component (N) is preferably dispersed in a liquid crystal medium.

Component (N) is preferably chemically inert, aging resistant and lipophilic and compatible with the liquid crystal compounds present in the liquid crystal medium. For the purposes of the present invention, in particular, compatibility means that component (N) does not react with the compound in any chemical reaction that impairs the function of the device.

The component (N) is preferably used in the liquid crystal medium in the following concentrations: 50% by weight to 0.01% by weight, particularly preferably 30% by weight to 0.1% by weight and very preferably 10% by weight to 0.1% by weight. The concentration of component (N) is even more preferably between 5% and 0.1% by weight.

In a preferred embodiment of the invention, component (N) comprises nanoparticles. In a preferred embodiment, component (N) comprises nanoparticles in a proportion of 50% by weight, 70% by weight, 90% by weight or more by weight. The component (N) is particularly preferably composed entirely of nanoparticle. The nanoparticles can be, for example, metal nanoparticles, metal oxide nanoparticles or clusters.

The nanoparticles preferably have a diameter of from 1 nm to 100 nm, more preferably from 1 nm to 50 nm, more preferably from 1 nm to 10 nm and even more preferably from 1 nm to 5 nm. Further preferably, the side length ratio d _max /d _min of the particles is at most 3:1, preferably at most 2:1. d _max here denotes the maximum length dimension of the particles and d _min denotes the minimum length dimension. The size and shape of the nanoparticles can be determined, for example, by a scattering method in solution or by a transmission electron microscope (TEM).

The nanoparticles used may have the same or different shapes, sizes and structures.

In a preferred embodiment of the invention, the nanoparticles comprise at least one anchoring group A ¹ . This is preferably an organic chemical group. The anchoring group A ^{1 is} additionally preferably a group which undergoes non-covalent interaction with the surface of the glass or metal oxide. This type of surface can be, for example, the surface of the substrate layer of the device.

In a preferred embodiment, the anchoring group A ¹ is constructed in such a way that hydrogen bonds can be formed via polar structural elements. Suitable groups are polar groups comprising groups selected from the group consisting of N, O, S and P, which are preferably stable to both air and water. A ¹ is preferably in the presence of one or more (preferably two or more) heteroatoms such anchoring group.

The anchoring group A ^{1 is} particularly preferably composed of at least two individual structural elements containing a hetero atom selected from N and O, preferably N, and at least one other between the structural elements and A covalently linked structure between one or more structural elements and the binding site of the anchoring group A ¹ is required.

The covalent structure consists of a chain or cyclic aliphatic group and/or an aromatic ring, preferably consisting of a saturated hydrocarbon chain and/or an aliphatic ring. The aliphatic ring contains, for example, cyclohexane and cyclopentane.

The anchoring group A ^{1 is} preferably a group of the following formula (A-1): *-E-[X ¹ -Z ¹ ] _a -X ² (A-1), wherein in each case independently, E Represents a single bond or any desired spacer group; X ¹ is selected from the group consisting of -NH-, -NR ¹ -, -O-, and a single bond; X ² is selected from -NH ₂ , -NHR ¹ , NR ¹ ₂ ,- OR ¹ and -OH; Z ¹ is selected from the group consisting of an alkenyl group having 1 to 15 C atoms, a carbocyclic group having 5 or 6 C atoms or a combination of such groups, wherein the groups are each In this case, it may be substituted by OH, OR ¹ , -NH ₂ , -NHR ¹ , -NR ¹ ₂ or halogen; R ¹ is the same or different from H, D or 1 to 30 C atoms at each occurrence. An aliphatic, aromatic and/or heteroaromatic organic group, wherein one or more H atoms may be replaced by D or F; a is equal to 0, 1, 2 or 3, preferably 1 or 2, excellently 1; and * indicates the binding site of the anchoring group.

The general names of the organic groups used for the purposes of this application are explained below. The specific embodiments are preferred in the present invention.

The aryl group in the sense of the present invention contains 6 to 60 C atoms; the heteroaryl group in the sense of the present invention contains 1 to 60 C atoms and at least one hetero atom, provided that the total number of C atoms and hetero atoms is at least 5. The hetero atom is preferably selected from the group consisting of N, O and/or S.

The aryl or heteroaryl group as used herein means a simple aromatic ring (i.e., benzene) or a simple heteroaromatic ring (e.g., pyridine, pyrimidine or thiophene) or a condensed (fused) aromatic or heteroaromatic polycyclic group. (eg naphthalene, phenanthrene, quinoline or carbazole). A condensed (fused) aromatic or heteroaromatic polycyclic group in the sense of the present application consists of two or more simple aromatic or heteroaromatic rings fused to each other.

In particular, an aryl or heteroaryl group optionally substituted by the above groups means a group derived from benzene, naphthalene, anthracene, phenanthrene, anthracene, indoline, , fluorene, fluoranthene, benzopyrene, benzophenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isophthalic And thiophene, dibenzothiophene, pyrrole, hydrazine, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6, 7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, oxazole, imidazole, benzimidazole, naphthimidazole, phenamimidazole, pyridoimidazole, pyrazine Imidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, indoloxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzo Thiazole, pyridazine, benzoxazine, pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenolphthalein, naphthyridine, azacarbazole, benzoporphyrin, phenanthroline, 1,2,3-three Oxazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3, 4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3, 5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4 , 5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, anthracene, pteridine, pyridazine and benzothiadiazole.

For the purposes of the present invention, alkyl, alkenyl or alkynyl which may be optionally substituted may preferably mean the following groups: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, Second butyl, tert-butyl, 2-methylbutyl, n-pentyl, second pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl , n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, Cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl Or octynyl. Optionally substituted alkoxy, alkylthio, alkenyloxy, alkenethio, alkynyloxy or alkynylthio is preferably methoxy, trifluoromethoxy, ethoxy, n-propoxy , isopropoxy, n-butoxy, isobutoxy, second butoxy, tert-butoxy, n-pentyloxy, second pentyloxy, 2-methylbutoxy, n-hexyloxy , cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy, 2,2,2-trifluoroethoxy Base, methylthio, ethylthio, N-propylthio, isopropylthio, n-butylthio, isobutylthio, second butylthio, tert-butylthio, n-pentylthio, second pentylthio, n-hexylthio, cyclohexyl sulfide Base, n-heptylthio, cycloheptylthio, n-octylthio, cyclooctylthio, 2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoro Ethylthio, ethylenethio, propylenethio, butenylthio, pentenethio, cyclopentenethio, hexenethio, cyclohexenethio, heptenethio, cycloheptenylthio, Octenylthio, cyclooctenethio, acetylenethio, propynylthio, butynylthio, pentynylthio, hexynylthio, heptynylthio or octynylthio.

In a preferred embodiment of the invention, the group E is a single bond or a spacer selected from an alkenyl group having from 1 to 20 C atoms, optionally selected from the group consisting of F, Cl, Bf, I and CN. Substituting a group wherein one or more CH ₂ groups in the alkenyl group may each be independently substituted with each other by the group: -O-, -S-, -NH-, -N(R ¹ )-, - Si((R ¹ ) ₂ )-, -CO-, -CO-O-, -O-CO-, -O-CO-O-, -S-CO-, -CO-S-, -N(R ¹ ) -CO-O-, -O-CO-N(R ¹ )-, -N(R ¹ )-CO-N(R ¹ )-, -CH=CH- or -C≡C-.

E particularly preferably represents a single bond or is selected from the group consisting of -(CH ₂ ) _b -, -(CH ₂ ) _b -O-, -(CH ₂ ) _b -O-CO- and -(CH ₂ ) _b -O-CO a group of -O-, wherein b represents an integer of from 1 to 20, preferably from 1 to 10.

R ^{1 is} preferably selected from an alkyl or alkoxy group having 1 to 15 C atoms (which may be optionally substituted by D and/or a halogen) or an alkenyl group, an alkynyl group or an alkenyloxy group having 2 to 15 C atoms. Or an alkynyloxy group (which is optionally substituted by D and/or halogen) and an aryl or heteroaryl group having 5 to 18 aromatic ring atoms, which are optionally substituted by D and/or halogen, and such groups The combination.

R ^{1 is} particularly preferably selected from alkyl or alkenyl groups having up to 15 C atoms, which are optionally substituted by D, phenyl and/or halogen.

The anchoring group A ^{1 is} particularly preferably a group of the following formula (A-2): Wherein E, X ¹ , X ² and R ¹ are as defined above, and c has a value of from 1 to 10, preferably from 1 to 5, particularly preferably from 1 to 3. R ¹ is preferably selected from the above preferred groups herein.

In another preferred embodiment of the present invention, the nano-particles free from the anchor group A ^1. In this case, it is preferably functionalized by means of other chemical groups which are preferably non-polar such as, if desired, substituted alkyl, alkoxy, alkylthio, alkene Base, alkenyloxy, alkenethio, alkynyl, alkynyloxy, alkynylthio, aryl, aryloxy, arylthio, aralkyl, heteroaryl, heteroaryloxy, heteroarylthio and Heteroaralkyl. These groups preferably have up to 20 C atoms, particularly preferably up to 10 C atoms.

In another preferred embodiment of the invention, component (N) comprises one or more compounds (V) having a three-dimensional structure and a molecular weight greater than 450 Da. In a preferred embodiment of the invention, the compound (V) has a molecular weight greater than 500 Da, more preferably greater than 600 Da, and most preferably greater than 700 Da. The compound (V) is preferably a molecular compound. Further, preferred embodiments are the preferred embodiments described above under the definition of the term "compound having a three-dimensional structure" in relation to the maximum size to minimum size ratio of the compound.

In a preferred embodiment, the compound (V) containing one or more anchoring groups A ^1.

In a preferred embodiment of the invention, component (N) comprises a single compound (V). In an equally preferred alternative embodiment of the invention, component (N) comprises a plurality of different compounds (V), preferably 2, 3, 4 or 5, particularly preferably 2 or 3 different compounds (V) .

The compound (V) is particularly preferably a molecular cage compound. Alternatively, however, the compound may also be a tetrasubstituted methane derivative.

In a preferred embodiment of the invention, the device thus comprises a component (N) comprising one or more of the following compounds (V): it has a three-dimensional structure and a molecular weight greater than 450 Da and is a molecular cage compound.

For the purposes of this application, a molecular cage compound means a polycyclic molecular compound whose atoms and chemical bonds form a three-dimensional closed structure (cage).

In a particularly preferred embodiment of the invention, the molecular cage compound is a fullerene derivative, a borane derivative, a carborane derivative, a sesquioxane derivative, a cubane derivative or a tetrahedral alkyl derivative. . The molecular cage compound is excellently a sesquioxane derivative.

In a particularly preferred embodiment of the invention, the device thus comprises a component (N) comprising one or more of the following compounds (V): it has a three-dimensional structure and a molecular weight greater than 450 Da and is a sesquiterpene derivative.

Preferred sesquiterpene oxide derivatives of the invention have the general structure N-1: Wherein each occurrence of R, on the same or different basis, represents an anchoring group A ¹ or a group R ¹ as defined above, which groups are identical or differently selected from H, D or have each occurrence An aliphatic, aromatic and/or heteroaromatic organic group of 1 to 30 C atoms, wherein one or more H atoms may be replaced by D or F.

Preferably, one, two or three groups R are anchoring groups A ¹ . More preferably one or two groups R, and one group R is an excellent and precise anchoring group A ¹ .

The anchoring group A ¹ is as defined above. The anchoring group A ^{1 is} preferably selected from the preferred embodiments shown above.

If the substrate layer used is a metal oxide layer (for example ITO) or a glass layer, preferably at least one anchor group A ¹ containing N and/or O atoms is present, for example, as an amine group, a hydroxyl group and/or an ether. The composition of the group.

If the substrate layer used is a polymer layer (preferably polyimine), at least one anchor group A ¹ containing an N atom (for example, present in the amine group) is preferably present.

However, according to the present invention, it is also preferred that the anchor group A ¹ is not present in the compound.

R ^{1 is} further preferably selected from an alkyl or alkoxy group having 1 to 15 C atoms (which is optionally substituted by D and/or a halogen) or an alkenyl group, an alkynyl group, an olefin having 2 to 15 C atoms. Or alkynyloxy group (which may optionally be substituted by D and/or halogen) or an aryl or heteroaryl group having 5 to 18 aromatic ring atoms (which may optionally be substituted by D and/or halogen) or such groups The combination of the group.

R ^{1 is} particularly preferably selected from alkyl or alkenyl groups having up to 15 C atoms, which are optionally substituted by D, phenyl and/or halogen.

A preferred embodiment of the molecular cage compound used in the present invention is a sesquiterpene oxide derivative shown below.

Further examples of molecular cage compounds of the invention are dimers or oligomers of sesquiterpene oxides which function by anchoring groups on each sesquiterpoxyalkylene unit. Chemical. a plurality of sesquiterpene units can be The organic groups bonded at the corners are joined to form a dimer or oligomer.

The liquid-crystalline medium of the present invention comprises one or more, preferably a plurality of liquid crystal compounds and, if desired, other compounds (e.g., stabilizers and/or palmitic dopants). Such compounds are well known to those skilled in the art. It is preferably used in a concentration of from 0% to 30%, particularly preferably from 0.1% to 20% and very preferably from 0.1% to 10%.

Preferably, at least three, particularly preferably at least four, and excellently at least five different liquid crystal compounds are used in the liquid crystal medium of the present invention.

According to the present invention, the liquid crystal medium may have a positive dielectric anisotropy Δ ε. In this case, Δε preferably has The value of 1.5.

According to the present invention, the liquid crystal medium may have a negative dielectric anisotropy Δ ε. In this case, Δε preferably has A value of -1.5.

According to the present invention, the liquid crystal medium may additionally have a low positive or negative dielectric anisotropy Δ ε. In this case, the following is preferably applied to the following Δε: -1.5 < Δ ε < 1.5. The invention is also related to such liquid crystal media. In this case, the following applies particularly preferably to -1.0 < Δ ε < 1.0.

The liquid crystal medium preferably has a nematic phase in a temperature range of 0 °C to 50 °C. The liquid crystal medium particularly preferably has a nematic phase in the range of -20 ° C to 80 ° C, and even more preferably in the range of -40 ° C to 100 ° C.

According to the invention, the liquid crystal medium can comprise any desired liquid crystal compound.

The liquid crystal medium preferably comprises one or more compounds of the following formula (F-1): Wherein R ¹¹ and R ¹² represent F, Cl, -CN, -NCS, -SCN, R ¹³ -O-CO-, R ¹³ -CO-O- or have 1 to 10 identically or differently at each occurrence An alkyl or alkoxy group of a C atom or an alkenyl or alkenyloxy group having 2 to 10 C atoms, wherein one or more of the above hydrogen atoms may be replaced by F or Cl, and one or more CH ₂ groups may be replaced by O or S; and R ^{13 represents,} on each occurrence, the same or differently represents an alkyl group having 1 to 10 C atoms, wherein one or more hydrogen atoms may be replaced by F or Cl, and one of them Or a plurality of CH ₂ groups may be replaced by O or S; Selected identically or differently at each occurrence Wherein X, at each occurrence, is the same or differently selected from the group consisting of F, Cl, CN or an alkyl, alkoxy or alkylthio group having from 1 to 10 C atoms, wherein one or more of the above groups are hydrogen atoms may be replaced by F or Cl, and wherein said one or more of the groups CH ₂ group can be replaced by O or S; and Z ^11, at each occurrence, identically or differently selected from -CO-O -, - O-CO-, -CF ₂ -CF ₂ -, -CF ₂ -O-, -O-CF ₂ -, -CH ₂ -CH ₂ -, -CH=CH-, -CF=CF-, -CF= CH-, -CH=CF-, -C≡C-, -OCH ₂ -, -CH ₂ O- and a single bond; and d is 0, 1, 2, 3, 4, 5 or 6, preferably 0 1, 2 or 3 is particularly preferably a value of 1, 2 or 3. For the sake of clarity, it should be noted that the group It can be the same or different each time it appears.

A particularly preferred embodiment of the liquid crystal compound used in the apparatus of the present invention meets the formulas disclosed in Tables A and B below.

The manner in which the apparatus of the present invention is produced is well known to those skilled in the art of devices incorporating liquid crystal media.

To this end, in particular, the following liquid-crystalline media will be included: - one or more liquid crystal compounds and - comprising nanoparticles and / or one or more compounds (V) component (N), the one or more compounds (V) Has a three-dimensional structure and a molecular weight of at least 450 Da It is applied to the substrate layer in the form of a layer. Preferably a layer is applied between the two substrate layers.

In accordance with the present invention, it may be desirable to carry out a heating and/or cooling step to obtain the initial vertical alignment of the liquid crystal compound.

To prepare a liquid crystal medium, the component (N) is dissolved or dispersed in a liquid crystal compound or a mixture including a liquid crystal compound.

The functional principle of the device of the present invention will be explained in more detail below. It should be noted that the scope of the claimed invention, which does not exist in the scope of the claims, is not limited by the

The light transmission rate of the device of the invention depends on the temperature. In a preferred embodiment, the transmittance of the device is higher at low temperatures and lower at elevated temperatures.

In a preferred embodiment, the apparatus of the present invention has a boundary state A and a boundary state B. For the purposes of this application, the term boundary state means a state in which the light transmittance reaches a maximum or minimum value and there is no further or substantially no further change when the temperature is further reduced or increased. However, this does not exclude further changes in light transmittance in the case where the temperature is significantly reduced or increased beyond the boundary state temperature.

Means preferably has a boundary state A (T _A having a light transmittance at a temperature lower than the boundary temperature θ _A) and the boundary conditions B (T _B having a light transmittance at a temperature higher than the boundary temperature θ _B), wherein : θ _A <θ _B and T _A> T _B.

θ _{A is} preferably between -15 ° C and +25 ° C, and more preferably between -5 ° C and +10 ° C.

θ _{B is} preferably between +60 ° C and +100 ° C, particularly preferably between +70 ° C and +90 ° C.

The temperature span between the two boundary temperatures θ _A and θ _B represents the range in which the device reacts to temperature changes and the transmittance changes (the operating range or switching range of the device). The device is preferably used at temperatures within this range. However, the device can also be used at temperatures outside this range, preferably at temperatures below θ _A .

According to the invention, the working range of the device can be set and varied by varying the concentration of the component (N) and/or the composition of the liquid crystal mixture. According to the invention, the operating range of the device can be additionally set and varied by changing the substrate material.

The switching range of the device is preferably above room temperature and above room temperature. Switching range span between the boundary temperature θ _A and θ _B and the apparatus whereby the plus value: 0 ℃ to 100 deg.] C; more preferably 5 ℃ to 80 deg.] C; even more preferably 20 ℃ to 60 ℃.

According to the present invention, as the temperature increases, the transition between the two boundary states A and B and as the temperature decreases, the transition between the two boundary states B and A proceeds gradually through the intermediate value of the transmittance T.

According to the present invention, a relatively large proportion of the liquid crystal compound is vertically aligned (vertical alignment) with the surface of the substrate at a low temperature. In the case of increasing the temperature, the proportion of the compound in the vertical alignment is lowered. From a certain temperature (the value depends on the component (N) used and the composition of the liquid crystal medium and the type of the substrate material), the compound is aligned with the surface of the substrate in a planar form. In the state A of the switching element The liquid crystal compounds are preferably predominantly vertically aligned and, when in the state B of the switching element, are preferably predominantly aligned in a planar arrangement.

A temperature dependent change in device transmittance can be achieved using a change in liquid crystal compound from vertical alignment to planar alignment.

The invention thus also relates to a method for temperature dependent control of light transmission via a device comprising a liquid crystal dielectric layer, characterized in that the liquid crystal medium comprises - one or more liquid crystal compounds and - comprising nanoparticles and/or one or more The component (N) of the compound (V), the one or more compounds (V) have a three-dimensional structure and a molecular weight of at least 450 Da, and the liquid crystal compounds change from a vertical alignment to a planar alignment with a change in temperature.

In this method, a polarizer is preferably present on one side of the liquid crystal dielectric layer and on the opposite side of the liquid crystal dielectric layer. A preferred embodiment of the polarizer is set forth in the previous section.

Examples are used to illustrate the manner in which such methods can be implemented. At the same time, this example also shows a preferred embodiment of the apparatus of the invention. In this example, a linear polarizer is present on one side of the liquid crystal dielectric layer. Another linear polarizer that is aligned to the plane of polarization in the same manner as the plane of polarization of the first linear polarizer is present on the opposite side of the layer of liquid crystal dielectric. In the case of a liquid crystal compound in a vertically aligned liquid crystal dielectric layer, light passing through the first polarizer thus also passes through the second polarizer. This corresponds to the boundary state _A having a high light transmittance T _A as defined above. However, in the case of a liquid crystal compound in a planar alignment liquid crystal dielectric layer, the polarization property of light passing through the first polarizer varies as it passes through the liquid crystal dielectric layer. This causes the light to be partially or completely blocked by the second polarizer, ie absorbed or reflected. This state corresponds to the boundary state _B having a low light transmittance T _B as defined above. At intermediate temperature values between the temperatures of boundary states A and B, the achieved transmittance values are between the boundary values A and B.

The device of the invention can be mounted to a window, a transparent facade, a door or a roof.

The invention thus also relates to the use of the device of the invention for adjusting light entry and/or energy input into the interior.

The invention further relates to the use of a liquid-crystalline medium comprising - one or more liquid crystal compounds and - comprising nanoparticles (or) and/or one or more compounds (V), the one or more compounds (V) A three-dimensional structure having a molecular weight of at least 450 Da, which is used for temperature-dependent adjustment of light transmittance from the environment to the enclosed space.

As described above, the present invention is not limited to buildings, but can also be used in transport containers (e.g., transport containers) or vehicles. It is especially preferred to mount the device on a glass pane of a window or to use the device as a component of a multi-pane insulating glass. The device of the invention can be mounted on the outside, inside or (in the case of multi-pane glass) a cavity between two panes of glass, wherein the inside means the side facing the interior of the glass surface. It is preferred to use a cavity located between the inside or between two glass panes (in the case of multi-pane insulating glass).

The device of the present invention can completely cover or be partially covered by the individual glass surfaces to which it is mounted. In the case of complete coverage, the effect on the transmittance through the glass surface is greatest. In contrast, in the case of partial coverage, even in In the state of a device having a low light transmittance, a certain amount of light also passes through the surface of the glass in the uncovered portion. Partial coverage can be achieved, for example, by mounting the device in a strip or in some form on a glass surface.

In a preferred embodiment of the invention, the device automatically adjusts the light transmission through the surface of the glass into the interior solely due to its temperature reactivity. No manual adjustment is required here.

In accordance with this preferred embodiment, the device does not include any electrode or other electronic component that can be used to electrically switch the device.

In an alternate embodiment of the invention, the device has electrical switchability in addition to its temperature switchability. In particular, electrodes are present in the device in this case, and the liquid crystal medium has a positive or negative dielectric anisotropy Δ ε. Preferably, Δε here 1.5 or △ ε -1.5. In this embodiment of the invention, manual, electrical facilitation switching from high light transmission to low light transmission can be performed on the device, and vice versa. This manner of achieving electrical switching of the liquid crystal medium from a vertical state to another state is well known to those skilled in the art of devices incorporating liquid crystal media.

Preferred liquid crystal compounds of the invention are shown in Tables A and B below.

The structure of the liquid crystal compound is given below by means of an acronym, wherein it is converted into a chemical formula according to the following Tables A and B. All groups C _n H _2n+1 and C _m H _2m+1 are linear alkyl groups having n and m C atoms, respectively; n, m, z and k are integers and preferably represent 1, 2, 3 , 4, 5, 6, 7, 8, 9, 10, 11 or 12.

Table A shows only the acronym for the parent structure. In individual cases, the acronym for the parent structure is followed by a code (separated by a dash) to replace the radicals R ^1* , R ^2* , L ^1* and L ^2* :

Table C below shows the stabilizers preferred for use in the liquid crystal media of the present invention.

Table C Note: n in this table represents an integer from 1 to 12.

All concentrations in this application are given in weight percent and are based on the corresponding mixture as a whole (including all solid or liquid crystal components, in which no solvent is present), unless otherwise stated.

The following abbreviations and symbols are used: Δn optical anisotropy at 20 ° C and 589 nm, Δ ε 20 ° C and dielectric anisotropy at 1 kHz, cl.p., T(N, l) clarification point [°C].

All physical properties were determined according to "Merck Liquid Crystals, Physical Properties of Liquid Crystals", status Nov. 1997, Merck KGaA, Germany, and have been determined and applied to temperatures of 20 °C. Unless otherwise explicitly stated in each case, the Δn value was measured at 589 nm and the Δε value was measured at 1 kHz.

The following examples are illustrative of the invention and are not intended to be limited to the subject matter of the invention derived from such examples.

Applications 1) General procedure for producing the device of the invention

The liquid crystal medium, the composition of which is varied according to the examples below, is introduced into an electro-optical unit having a thickness of about 4 μm. The substrate material of the unit is based on the following examples There is a change (ITO, glass or AL-3046 (90 ° friction of polyimine, JSR)). Two linear polarizers are provided in the unit that are parallel-aligned to the plane of polarization on the front or back side of the cells. Finally, the units are subjected to temperature dependent measurements of light transmission.

2) Examples of liquid crystal media used

a) Mixture 1+0.3% N-2

b) Mixture 2+0.25% N-2

c) Mixture 3+0.25% N-2

d) Mixture 4+0.25% N-2

e) Mixture 5+1.0% N-8

f) Mixture 5+1.0% N-7 component (N): Liquid crystal mixture used:

3) An example of the device of the present invention and its switching window

The table below shows the results of combinations of media a) to f) with different substrate materials AL-3046, ITO and glass in the device of the invention. For each device, the switching window (i.e., the range between boundary states A and B) is given in degrees Celsius.

4) Switching process of the device of the present invention

The apparatus of the present invention displays a stepwise change in the temperature transmittance of the entire switching range ("switching window").

Fig. 1 shows, by way of example, a switching process (triangle symbol) of a device comprising a medium a) and a substrate material ITO (column 1, row 1 of the above table). In contrast, the change in light transmittance (circular symbol) of a device containing medium a) but no component (N) is shown.

It can be seen that for the device of the invention, the operating range of 40 ° C - 70 ° C (switching window, highlighted by the line of arrows between the dashed lines) occurs from high transmittance to low with increasing temperature. Gradual transfer of light transmittance change. In the case of a device containing a liquid crystal medium without component (N), the light transmittance does not change with temperature.

In addition, FIG. 2 shows a switching process of the unit including the medium c) and the substrate material AL-3046 (the third column and the second row of the above table). A curve is drawn in the form of a triangular symbol for the measured value of the transmittance. In contrast, the change in light transmittance (circular symbol) of a device containing medium c) but no component (N) is shown.

It can be seen that for the device of the invention, the operating range of 5 ° C to 50 ° C (switching window, highlighted by the line of arrows between the dashed lines) occurs from high transmittance to low with increasing temperature. The gradual shift in light transmittance. In the case of a device containing a liquid crystal medium and no component (N), the light transmittance does not substantially change with temperature.

Figure 1 shows the switching process (triangle symbol) of a device containing medium a) and substrate material ITO (column 1, row 1 of the table on page 50).

Figure 2 shows the switching process for cells containing medium c) and substrate material AL-3046 (column 3, row 2 of the table on page 50).

Claims (14)

A temperature-reactive device for adjusting light transmittance, characterized in that it comprises a liquid crystal medium layer, wherein the liquid crystal medium comprises one or more liquid crystal compounds and comprises (1) nano particles and (2) one or more compounds (V) a component (N) of at least one of the compounds (V) having a three-dimensional structure and a molecular weight greater than 450 Da, wherein the device has a light transmittance T _A at a temperature below the boundary temperature θ _A A boundary conditions of the boundary conditions T _B and B has a light transmittance at temperatures above the boundary temperature [theta] _B, wherein: θ _A <θ _B and T _A> T _B. The device of claim 1, wherein the liquid crystal dielectric layer is disposed between the two substrate layers. The device of claim 1 or 2, wherein the device has two or more polarizers, one of which is disposed on one side of the liquid crystal dielectric layer and the other of which is disposed on an opposite side of the liquid crystal dielectric layer . The device of claim 1 or 2, wherein the device does not include an alignment layer adjacent to the liquid crystal dielectric layer. The device of claim 1 or 2, wherein the nanoparticles and/or compound (V) carry at least one anchoring group A ¹ , the at least one anchoring group A ¹ is non-covalently interacting with the glass or metal surface It acts as an organic chemical group. The device of claim 1 or 2, wherein the component (N) comprises a diameter of 1 nm to 50 Nanoparticles of nm. A device according to claim 1 or 2, wherein the component (N) comprises one or more compounds (V) having a three-dimensional structure and a molecular weight of more than 450 Da, and the compounds (V) are molecular cage compounds. A device according to claim 1 or 2, wherein the component (N) comprises one or more compounds (V) having a three-dimensional structure and a molecular weight of more than 450 Da, and the compounds (V) are sesquioxane derivatives. The apparatus of claim 1 or 2, wherein the boundary temperature θ _A is between -15 ° C and +25 ° C and wherein the boundary temperature θ _B is between 60 ° C and 100 ° C. The apparatus of claim 1 or 2, wherein the transition between the two boundary states A and B as the temperature increases and the transition between the two boundary states B and A as the temperature decreases is via the middle of the transmittance T The value is gradually carried out. Use of a device according to any one of claims 1 to 10 for adjusting light entry and/or energy input into the interior. A method of producing a device according to any one of claims 1 to 10, characterized in that a liquid crystal medium comprising: a liquid crystal medium comprising: one or more liquid crystal compounds and comprising (1) nanoparticle and (including) 2) A component (N) of at least one of one or more compounds (V) having a three-dimensional structure and a molecular weight of at least 450 Da. a liquid crystal medium comprising one or more liquid crystal compounds and And comprising (1) a nanoparticle and (2) a component (N) of at least one of the one or more compounds (V) having a three-dimensional structure and a molecular weight greater than 450 Da, the liquid crystal medium It is characterized in that it has the following dielectric anisotropy Δ ε: -1.5 < Δ ε < 1.5. A method for controlling light transmittance through temperature dependence of a device comprising a liquid crystal dielectric layer, characterized in that the liquid crystal medium comprises one or more liquid crystal compounds and comprises (1) nano particles and (2) one or more compounds (V) In at least one component (N), the one or more compounds (V) have a three-dimensional structure and a molecular weight of at least 450 Da, and the liquid crystal compounds change from a vertical alignment to a planar alignment as a function of temperature.