MXPA00005835A - Uv protected electrochromic device - Google Patents

Abstract

Electrochromic devices are protected from UV light by nanoparticles.

Description

DEVICE ELECTROCROMIC PROTECTED FROM ULTRAVIOLET RAYS FIELD OF THE INVENTION The present invention relates to an electrochromic device protected against UV.

BACKGROUND OF THE INVENTION Electrochromic devices are already known, for example from the publications D. Theis in Ullmann's Encyclopedia of Industry Chemistry. Vol. A 8, page 622, Verlag Chemie 1987 and WO-A 94/23333 * Two basic types are distinguished: T ± po 1: Full-surface electrochromic device. Type 2: Electrochromic signaling devices with structured electrodes. Type 1 finds application, for example, in the case of electrically obscure window panes or in electrically diaphragmatic car mirrors. Such devices are known, for example, from U.S. patent application 4 902 108. Type 2 finds application in the case of REF. : 120617 segmented and matrix markers. Such signaling devices have been proposed, for example, in the German patent application P 196 31 728. Such devices can be observed by transmission or reflection in the case of a mercury. WO-A 94/23333 compares electrochromic materials of different construction, which, however, are not used as signaling devices: Construction a: The electrochromic substances are in the form of a film or a solid layer on the electrodes ( see Ullmann, previously indicated). Construction b: Electrochromic substances are deposited on the electrodes in the form of a layer in the redox process (see Ullmann, previously indicated). Construction c_ Electrochromic substances are permanently in solution. For construction a) the most known electrochromic material is the tungsten oxide / palladium hydride pair. For the construction b) viologens have been described as electrochromic substances. These devices are not self-extinguishing, that is to say that the generated image remains after the disconnection of the current and can only be canceled again by reversing the poles of the voltage. Such devices are not particularly stable and do not allow a large number of connection cycles. In addition, the cells formed especially with tungsten oxide / palladium hydride can not be operated with incident light but can only be operated by reflection due to the diffraction of the light on these electrochromic layers. It is known by the publications Elektro himiya, 13, 32-37 (1977), 13, 404-408, 14, 319 322 (1978). US-A 4 902 108 and US-A 5 140 455 an electrochromic system of the construction c) cited last. In an electrochromic cell, which is formed by glass plates covered with a conductive manner, a solution of a pair of electrochromic substances in an inert solvent is contained. As a pair of electrochromic substances, respectively, a reversibly reducible electrochromic substance and a reversibly oxidizable electrochromic substance are used. In basic condition both are colorless or only slightly colored. Under the effect of an electrical voltage one of the substances is reduced, the other oxidizing, with which both are colored. After the voltage disconnection, the base substance is regenerated in the case of the two substances, with which a discolouration or a color rinse occurs.

ED! + OX2 OX? + RED; (colorless) (colored) (low energy pair) (for high energy) It is known from US-A 4 902 108 that those pairs of redox substances are suitable in which the reducible substance contains at least two chemically reversible reduction thresholds in the cyclic voltammogram and in which the oxidizable substance contains, correspondingly, at least two chemically reversible oxidation thresholds. According to WO-A 94/23333 such systems in solution with the construction c have, without However serious inconveniences. The diffusion of the electrochromic substances in the solution causes unclear color limits causes a high current consumption for the maintenance of the colored state since the colored substances are permanently decomposed by recombination and reaction on the corresponding counter electrode. However, various applications have been described for those electrochromic cells of construction c). In this way they can be shaped, for example, as rear-view mirrors for cars that can be obscured by the application of a voltage during night driving and, thus, prevent the dazzling caused by the headlights of subsequent vehicles (see for example US-A 3 280 701, US-A 4 902 108, EP-A 0435 689). In addition, such cells can also be used in window panes or for self-sunroof roofs, which obscure sunlight after the application of a voltage. The use of such devices as electrochromic signaling devices has also been described, for example in segmented signaling devices or matrix-structured signaling devices (German patent application P 196 31 728). Electrochromic cells are usually constituted by a pair of glass plates, one of which is specular in the case of automotive mirrors. One side of these crystals is coated on its entire surface with a transparent, electrically conductive layer, for example indium tin oxide (ITO), this conductive coating being subdivided, in the case of signaling devices, into electrically separated segments each other, that are contacted individually. From these crystals a cell is now constructed by its connection with its coated, electrically conductive sides, directed to each other, by means of a joint ring to form a cell. In this cell an electrochromic liquid is now charged through an opening and the cell is hermetically sealed. The two crystals are connected to a voltage source through the ITO layers. The electrochromic devices described above have, as a rule, a sensitivity to light, especially against UV light. Therefore, for example, US-A 5 280 380 electrochromic devices containing UV stabilizers have been described. Most of the time, organic compounds have been used to absorb UV light, which have a molecular absorption band in the relevant wavelength range and non-absorbers in the visible spectral range. In these compounds it is a disadvantage that they have to be dissolved at partially high concentrations in the electrochromic solution or in a polymeric layer, which is disposed on one of the two plates. However, frequently, the solubility in these media is limited and, as a consequence, so is the activity of the UV absorber. In addition they can be bleached under the effect of light and / or they can evaporate from the polymeric substrate or they can be washed away. It is also known that solid inorganic materials can absorb UV light. These inorganic particles can absorb and / or disperse harmful light ranges and / or according to their size and the choice of material. In this case preference must be given to the absorption against dispersion since, especially in the case of an incorporation of the particles in the material to be protected, the scattered photons could subsequently damage it. In addition, a too high dispersion ratio of the light leads to a turbidity of the material to be protected. It is known from the publication Absorption and Scattering of Light by Small Particles. C.F. Bohren. D. R. Huffman, pages 93 to 104 and 130 to 141, 1983 that as the size of the particles decreases, their light absorption capacity is greater than their ability to disperse light. For a transparent absorber of. UV light are therefore suitable only very small particles. To ensure the absence of color of the UV light absorber, the material of the particles must have an absorption edge in the wavelength range between approximately 300 nm and 400 nm. According to WO-A 93/06164, for an effect of this type, materials with an energy separation between 2.8 eV and 4.1 eV are suitable., which corresponds to a range of wavelengths comprised between 303 nm and 445 nm. For this application purpose, Ti02, ZnO, Ce02, SiO, for exa, WO-A 93/06164, WO-A 95/09895 and WO-A 92/21315, among others, are used for this purpose. Thus, there was the task of making available UV absorbers, which did not present the drawbacks known from the state of the art and which were suitable in the best possible way for the protection against UV of the electrochromic cells.

DETAILED DESCRIPTION OF THE INVENTION It has now been found that electrochromic devices, described above, can be effectively protected against destruction due to UV light by means of nanoparticles. The object of the invention is, therefore, an electrochromic device, which is protected against UV light by means of nanoparticles. The object of the invention is preferably an electrochromic device, constituted by two plates or sheets, at least one of which is transparent and which are provided with a conductive layer on the sides facing each other, at least one conductive layer being transparent , and being joined together with a sealing ring, a volume being defined by means of the plates or sheets and the sealing ring, in which is an electrochromic means, characterized in that the electrochromic device is protected against UV light by means of of nanoparticles. The plates are constituted by glass or synthetic material, the sheets are constituted by synthetic material or by special thin glass. In a special mode form of the electrochromic device, the nanoparticles are contained in the electrochromic system and / or are fixed on and / or at least on one of the two transparent plates or sheets. According to the invention, electrochromic devices in which at least one of the two conductive layers is coated with an electrochromic layer, as well as electrochromic devices in which the electrochromic means represents an electrochromic solution, characterized in that the electrochromic device is protected against the electrochromic device, are especially preferred. UV light by means of nanoparticles. Suitable nanoparticles are those based on SiC, AISi, Fe203, Fe30, Ti02, ZnO, GaP, Ce02, ZnS, Sn02, SiyGe? -y, WxM ?? _ x03, NiO, Bi203, ln203, Hf02, BaTi03, CaTi03, Ge, A1P, GaN, where 0. 7 < and < l and O < x < í. Particularly suitable nanoparticles, in the sense of the invention, are the materials known from the literature and from the aforementioned patent applications, based on Ti02, ZnO, Ce02, SiC, AISi, Fe203, Fe304, WxM ?? _ x03 , BaTi03, CaTi03 or mixtures thereof. A turbidity of an electrochromic device due to the UV absorber particles is not acceptable since it is required in the various fields of application mentioned, such as automotive mirrors or signaling devices, a high transmission of light roasted, as, especially , a clear image. The radical-forming particles are especially unusable when these panicles are in the electrochromic solution. An interaction with the OXi and RED2, as a rule radical or ionic, formed by the action of the electrodes, would intervene in the balance indicated above and lead to undesirable color changes and / or insufficient color dissipation after the disconnection of the tension. Nanoparticles with an average diameter of less than 500 nm, preferably less than 100 nm, more preferably less than 50 nm, most preferably less than 20 nm are particularly preferred. Therefore, UV light absorbers containing predominantly silicon particles and / or solid compounds, in which the silicon is present in stoichiometric excess, are very particularly preferred. An average diameter of less than 120 nm is advantageous. These have advantageous properties such as high transparency in the visible spectral range at low particle concentrations, high air stability, high compatibility with the environment and biological and complete absence of photocatalytic activities as well as the separation by filtration of light in the range UVA and UVB with high efficiency. Mean diameter should be understood as the maximum of the numerical distribution. Elemental silicon consists of crystalline amorphous silicon, preferably it is constituted by crystalline silicon. The size of the silicon particles is preferably between 1 nm and 120 nm, more preferably between 1 nm and 70 nm, very particularly preferably between 10 nm and 50 nm. Preferably these particles have a size distribution with a maximum semiamplitude of 40 nm. Silicon particles with this average diameter are preferably produced by means of gas phase reaction (CVR) according to the process described in US-A 5 472 477. Likewise, manufacture according to J. Phys. Chem. , 97, page 1224 up 1230 (1973). J. Vac. Sci. Technol. A10, page 1048 (1992) as well as Int. J. Heat Mass Transfer 31, page 2236 (1988). They are encompassed by the expression of solid compounds, the solid compounds at room temperature, such as for example silicides CaSi2 and / or BaSi2- are preferably encompassed by the expression of compounds in which the silicon is present in stoichiometric excess. the compounds of the formula SixZ? _? with 0.5 < x < 1, preferably 0.7 < x < 1 and Z = C, N, O, Ge, Ca, Ba and Mr. The presence of other materials describes the energetic position of the absorption edges in certain limits and modifies the shape of the edges. As solid compounds, SixCix or SixGe? _x are preferred in this case. Nanoparticles of all the materials described hitherto, which have the form of a sphere or are almost spherical, are preferred. It will be understood by the almost spherical expression, for example, ellipsoids with a ratio between axes of 1: 4. preferably 1: 2. In the same way, nanoparticles of all the materials described hitherto, which have a core-shell structure, are preferred. The envelope may be organically modified. The wrapping is constituted, for example, by an oxide of the material of the nanoparticles. However, it can also be constituted by another material that is transparent in the visible and whose refractive index is similar to that of the nanoparticles. The thickness of an oxide layer can be comprised, for example, between 1 and 300 nm. In a preferred embodiment of the invention, the solid compounds, in which the silicon is present in stoichiometric excess, have a core-shell structure. In this case it is preferred that it be constituted by a titanium nitride core and by a silicon shell, the volume ratio of the silicon being at least 30% of each particle. The average diameter of the particles of all types described heretofore is preferably less than 120 nm, more preferably less than 100 nm, very particularly preferably less than 50 nm. These preferably have a particle size distribution with a maximum semiamplitude of 40 nm, preferably of 30 nm, more preferably of 20 nm. The manufacture of the solid compounds, including their core-shell structure, can be carried out, for example, by means of thermal decomposition of a gas containing silicon, such as, for example, silanes, organosilanes or SiCl 4 / in such a way that an aerosol is formed (see J. Phys. Chem., 97, page 1224 to 1230 (1973) J. Vac. Sci. Technol.A 10. page 1048 (1992)). By mixing other gases, which contain, for example, germanium or carbon, stoichiometrically constituted compounds are formed correspondingly. In the case of solid compounds with a core-shell structure, the core is first produced by means of the process described above, and then the shell is applied by decomposition or gas-phase reaction of the correspondingly constituted gases, as for example SiH4 or SiCl4 together with H2. The thermal decomposition can take place in a gas phase reactor, preferably in a CVR reactor (Chemical Vapor Reaction), or also by laser absorption. (See J. Heat Heat Transfer, 31 page 2239 (1988).) Thermal decomposition of gases is especially suitable for the manufacture of crystalline particles, and manufacturing by means of a PECVD (Plasma Enhanced Chemical Vapor) process is also possible. Deposition) (see J. Vac. Sic. Technol., A10, page 1048 (1992)) In the latter process amorphous particles are formed which can be crystallized by means of a subsequent heat treatment (see Nanostructured Materials, volume 6, pages 493 up to 496 (1995).) The particles contained in the UV light absorber can also be present in the form of agglomerates In the case of silicon, the optical properties of the agglomerate are differentiated from those of the primary particles since new water channels are formed. absorption due to the electromagnetic interaction of the particles with each other, which are also partially in the visible spectral range. The primary particles, contained in the UV light absorber, can also be surrounded by an oxide layer. In this way direct contact of the primary particles and, thus, their agglomeration is prevented. The thickness of the oxide layer is preferably from 1 nm to 300 nm, more preferably from 10 to 100 nm. Advantageous oxide layers are those whose refractive index in the visible spectral range has values very similar to those of the materials to be protected against UV irradiation, such as for example: polycarbonate, polyurethane, organic solvents such as the electrochromic medium. In this way, the light scattering effect is reduced and the matrix remains transparent. This oxide layer can be formed, for example, by oxygen metering in the CVR reactor after the manufacture of the particles. In a preferred embodiment, the UV light absorber according to the invention also contains particles, for example oxides and / or metal nitrides, which have an absorption in the red spectral range of 600 nm <; ? < 700 nm higher than in the blue-green spectral range of 400 nm < ? < 550 nm. As such additives, titanium nitride particles with an average diameter of 1 nm to 400 nm, preferably 10 nm to 120 nm or agglomerates of these primary particles of titanium nitride are preferred. Their manufacture can be carried out, for example, according to US-A-5 472 477. In a preferred embodiment, the UV light absorber contains, in addition to silicon particles, also TiN particles with an average diameter of 10 to 120 nm. This UV light absorber acts very efficiently in the UVA range and at the same time guarantees a neutrality of color with high transparency. Also preferred are particulate additions of sodium aluminum silicates (ultramarine pigments), obtainable for example from the company Nubiola S.A., under the designation Nubix® pigment. They may also contain, as an additive, hexacyanoferrate (II) of iron (III). In another form of embodiment of the invention, the UV light absorber is preferably constituted by a mixture formed by particles containing silicon and by particles of the following group: silicon carbide and / or oxides of the metals titanium, cerium, tungsten, zinc , tin as well as iron. By means of such mixtures, the absorption edge, especially its slope, can be manipulated. The size of the aggregated particles is preferably between 1 nm and 200 nm. These can also be obtained, inter alia, according to the process described in US-A 5 472 477. The materials for the electrochromic layers are either inorganic layers such as the above-described system of tungsten oxide / palladium hydride or are organic layers, which they are constituted, for example, by electrochromic substances such as those which will be cited below for the special application in an electrochromic solution. Especially suitable are oligomeric and polymeric electrochromic substances of this type for layers, as well as those electrochromic substances which must be rendered insoluble, for example by the choice of counter-ion.Another object of the invention is the electrochromic devices according to the invention, characterized in that they contain as an electrochromic solution. a) a solvent, b) at least one oxidizable redx substance reversibly, and at least one 0x2 reducible substance reversibly dissolved in this solvent, which become respectively forms OXi or RED2 by donating electrons an anode and by the gain of electrons in a cathode, being related to at least one of these donations of electrons or electron gains a modification of the extinction in the visible range of the spectrum, and recovering the original form REDi and 0X2 respectively after load compensation, and c) dispersed nanoparticles. Dispersed nanoparticles will be understood as the inorganic solid materials described above in greater detail. By modification of the extinction. in the visible range of the spectrum it can be understood that a) 0X2 and / or REDi are colorless or that they are only slightly colored, while the RED2 and / or 0X? They formed at the cathode or the anode, are colored, preferably are strongly colored, b) at least one of two electrochromic substances 0x2 or Redi is colored, while forms RED2 or OXi, formed on the cathode or on the anode, are not colored or are only colored weakly or otherwise. By choosing the REDi and 0X2 electrochromic compounds and / or their mixtures arbitrary monochromatic color shades can be established. For a polychrome adjustment of the color, two or more electrochromic devices of this type can be stacked, by means of their surface, each of these devices being able to generate a different color tonality. Preferably, such a stack will be constituted in such a way that the devices in physical contact have in common a transparent plate, which is also coated in a conductive manner on both sides and which is subdivided into segments according to the corresponding mode. By way of example, a stack formed by three electrochromic devices is then constituted by at least four plates. Through the connection of segments in several of these stacked devices, multicrhythmic signals can be made. If segments are connected, successively, of various devices of this type, mixed colors will be obtained. In this way, arbitrary colors can be represented in the context of a trichromy, that is, for example, images in multiple colors. The 0X2 and REDi, suitable in the sense of the invention, are those substances that provide RED2 and OXi products at the time of their reduction or oxidation on the cathode or on the anode in the aforementioned solvent, which do not intervene in a subsequent chemical reaction, but can be oxidized or reduced again completely to give 0X2 and REDi. The reducible OX2 substances, suitable in the sense of the invention, are those in which, a) they show a cyclic voltammogram in the solvent used in the device, having at least one level, preferably at least two chemically reversible levels of reduction. bl) representing an organic compound, for example cyclic, which is transformed into a compound, for example an open ring after the gain of one or two electrons with breaking of a bond s and which is transformed back into the starting compound, cyclic example, after the loss of one or two electrons. The oxidizable REDi substances, suitable in the sense according to the invention, are those which, a2) show a cyclic voltammogram in the solvent used in the signaling device, having at least one level, preferably two chemically reversible levels of oxidation, b2) represent an organic compound, for example cyclic, which is transformed into a compound, for example an open ring, after loss of one or two electrons with breakage of a bond s and which is transformed back into the starting compound, for example cyclic, after gain of one or two electrons. Such compounds, indicated in bl) and b2) show, as a rule, in the cyclic voltammogram a level of reduction or chemically irreversible oxidation followed by a level of oxidation or chemically irreversible reduction. As a rule, two electrons are transferred in it. moment of the break or of the formation of the link s. The compounds indicated in bl) and b2) should therefore not be limited to those that exhibit the aforementioned behavior in the cyclic voltammogram or those in which two electrons are transferred at the time of rupture or link formation or those with which is related the opening of the ring or the closure of the ring with the break or the formation of the bond s. In the sense of the invention, the suitable 0X2 are: 2X- 10 '"- • CH O - R" (VI), X- R 10 wherein R up to R R °, R > 3 > 'RIVER, up to R 19 independently of one another, mean alkyl having 1 to 18 carbon atoms, alkenyl having 2 to 12 carbon atoms, cycloalkyl having 4 to 7 carbon atoms, aralkyl having 7 to 15 carbon atoms or aryl having 6 to 10 carbon atoms or R4; R5 or R8; R9 can together form a bridge - (CH2) 2-o- (CH2) 3-, R6, R7 and R22 to R25, independently of one another, denote hydrogen, alkyl having 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, carbon, halogen, cyano, nitro or coxycarbonyl with 1 to 4 carbon atoms or R, 22, • • 2¿3i and .t // rom D R24; "R25 can form a bridge -CH = CH-CH = CH-, R10; Rn; R12; R13 and R14; R15, independently of one another, mean hydrogen or in a paired manner a bridge - (CH2) 2-, - (CH2) 3- or -CH = CH-, R20 and R21, independently of each other, mean 0, N-CN, C (CN) 2 or N-aryl with 6 to 10 carbon atoms, R "26 and R mean hydrogen, alkyl with 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, halogen, cyano, nitro, alkoxycarbonyl with 1 to 4 carbon atoms or aryl with 6 to 10 carbon atoms, R69 to R74, independently of one another, mean hydrogen or alkyl with 1 to 6 carbon atoms or R69, R12 and / or R70, R13 together form a bridge -CH = CH-CH = CH-, E1 and E2, independently of each other, mean O, S, NR1, or C (CH3) 2 or E1 and E2 together form a bridge -N- (CH2) 2-N-, R1 means alkyl with 1 to 18 atoms of arbono, alkenyl with 2 to 12 carbon atoms, icloalkyl with 4 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms, aryl with 6 to 10 carbon atoms, Z1 means a direct bond -CH = CH -, -C (CH3) = CH-, -C (CN) = CH- -CC1 = CC1-, -C (OH) = CH-, -CC1 = CH-, -C = C-, -CH = NN = CH-, -C (CH3) = NN = C (CH3) - or -CC1 = NN = CC1-, Z2 means - (CH2) r- O -CH2-C6H4- CH2-, r means an integer from 1 to 10, R101 to R105, independently of one another, mean aryl with 6 to 10 carbon atoms or an aromatic or quasiaromatic ring with 5 or 6 members, heterocyclic, optionally benzo-ring, R107 , R109, R113 and R114, independently of each other, mean one of the residues of the formulas (CV) up to (CVI I) where R 108 R 115 and R, independently of one another, mean aryl with 6 to 10 carbon atoms or a radical of the formula (CV), R110 to R112, R117 and R118, independently of one another, mean hydrogen, alkyl with 1 to 4 carbon atoms, halogen or cyano, E101 and E102, independently of one another, mean O, S or NR 119 R 119 R 122 independently of one another, meaning alkyl with 1 to 18 carbon atoms, alkenyl with 2 to 8 carbon atoms , cycloalkyl with 4 to 7 carbon atoms, arylalkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms, R106, R120, R121, R123 and R124 means, independently of each other, hydrogen, alkyl having 1 to 4 carbon atoms , alkoxy with 1 to 4 carbon atoms, halogen, cyano, nitro or alkoxycarbonyl with 1 to 4 carbon atoms, or R120, R121 or R123, R124 together form a bridge -CH = CH-CH = CH- and X ~ means an inert anion under redox conditions. In the sense of the invention, suitable OX2 are also metal salts or metal complexes, preferably those metal ions, whose oxidation levels are differentiated by 1. Suitable metal ions 0X2 / RED2 are for example Fe3 + / Fe2 +, Ni3 + / Ni2 +, Co3 + / Co2 +, Cu2 + / Cu +. The REDi suitable according to the invention are: R "/" \ r N \ (H), V), where R28 to R31, R34, R35, R38, R39, R46, R53 and R 54 independently of each other, they mean alkyl with 1 to 18 carbon atoms, alkenyl with 2 to 12 carbon atoms, cycloalkyl with 4 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms, R32, R33, R36, R37, R40, R41, R42 to R45, R47, R, 480, R > 4"9 to R, 532" and R, 5"5 to R, 5 ° 8 ° mean, independently of each other, hydrogen, alkyl having 1 to 4 carbon atoms, alkoxy with 1 to 4 carbon atoms, halogen, cyano, nitro, alkoxycarbonyl having 1 to 4 carbon atoms, aryl with 6 to 10 carbon atoms, YR 57 and R additionally mean a heterocyclic, aromatic or quasiaromatic ring with 5 members, which optionally is benzo-ring, and R48 also means NR75R76 or R49; R5s and / or R51; R52 form a bridge - (CH2) 3-, - (CH2) 4-, ~ (CH2) 5- or -CH = CH-CH = CH-, Z3 means a direct bond , a bridge -CH = CH = or -N = N-, = Z = means a direct link, a bridge = CH-CH = or = NN =, until E ~ E10 and E11, independently of each other, mean 0, S , NR or C (CH3) 2 and E5 further means C = 0 or S02, E3 and E4 can mean, independently of each other, in addition -CH = CH-, E6 to E9 mean, independently of each other, S, Se or NR59, R59; R75 and R76 mean, independently yes, alkyl with 1 to 12 carbon atoms, alkenyl with 2 to 8 carbon atoms, cycloalkyl with 4 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms, aryl with 6 to 10 carbon atoms, and R75 means, in addition, hydrogen or R75 and R76, in the meaning of N75R76 mean, together with the N atom, with which they are linked, a ring with 5 or 6 members, which contains, if appropriate, other heteroatoms, R ' 61 to R, independently of one another, denote hydrogen, alkyl having 1 to 6 carbon atoms, alkoxy with 1 to 4 carbon atoms, cyano, alkoxycarbonyl with 1 to 4 carbon atoms or aryl with 6 to 10 carbon atoms and R61; R62 and R67; R68, independently of each other, also form a bridge - (CH2) 3-, - (CH2) 4- or -CH = CH-CH = CH- and v means an integer between 0 and 10. The REDi, suitable in the sense of the invention, are also metal salts or metal complexes, preferably those metal ions, whose oxidation levels are differentiated by 1. Suitable REDi / OXi metal ions are, for example, Fe2 + / Fe3 +, Ni2 + / Ni3 +, Co2 + / Co3 +, Cu + / Cu +. Also suitable in the sense of the invention are those redox couples that are linked together via a covalent bridge according to the formula Y - [- (- BZ) a - (- BY-) b-] cBZ (I) , wherein Y and Z, independently of each other, mean an OX2 or RED residue, with OX2 meaning, however, at least one Y and means RED at least one Z, where 0X means the rest of a Redox system that can be reversibly reduced electrochemically and REDi means a remnant of a Redox system oxidizable electrochemically in a reversible manner, B means a bridge member, c means an integer from 0 to 1,000, and a and b mean, independently of each other, an integer from 0 to 100. Preferably it is verified (a + b) .c < 10,000. In this case, it is indicated by the term "reversibly reducible or electrochemically oxidizable" that the electronic transfer can be carried out without or also with modification of the structure completely within the meaning of the aforementioned definition of the 0X2 and REDX according to the invention. It is particularly desirable to indicate, by means of the electrochromic compounds of the formula (I), those of the formula 0X2-B-RED? (la), 0X2-B-RED! -B-0X2 (Ib), REDx-B-0X2-B-RED? (le), or 0X2- (B-RED? -B-0X2) d-B-RED? (Id) where 0X2, REDi and B have the meaning indicated above and d means an integer from 1 to 5. In the formulas (I) and (la) to (Id) they are to be indicated with 0X2 and REDi especially residues of the above-described ORP systems of the formulas (II) up to (IX), (Cl) up to (CIV) and (X) up to (XX), verifying the link with the bridge member B through one of the remains R¿ up to R, R- " to R, 27, R, 2a8a to R58, R61, R62, R67, R68, R122 or, in the case where one of the residues E1 or E2 means NR1 or one of the residues E3 to ill means N, 59 one of the remains E up to E •, 102 means NR 119 through R1, R59 or R119 and the above-mentioned residues mean then a direct link, and B means a bridge of the formulas - (CH2) n- or - [Y1s (CH2) m -.Y2] or - (CH2) p-Y3q-, can be substituted by alkyl with 1 to 4 carbon atoms, by alkoxy with 1 to 4 carbon atoms carbon, by halogen or by phenyl, Y1 to Y3, independently of each other, mean O, S, NR60 'C00, CONH, NHCONH, cyclopentadienyl, cyclohexadienyl, phenylene or naphthylene, R60 means alkyl with 1 to 6 carbon atoms, alkenyl with 2 to 6 carbon atoms, cycloalkyl with 4 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms, n means an integer from 1 to 12, m and p, independently of each other, they mean an integer from 0 to 8, or means an integer from 0 to 6 and qys, independently of each other, mean 0 or 1. Examples of metal salts or metal complexes, which can be used as 0X2 or REDi, are Fe3 + / 2 +, Ni3 + / 2 +, Co3 + / 2 +, Co3 + / 2 +, Cu2 + / +, [Fe (CN) 6] 3 '4", Fe [Fe (CN) 6] 30 / ~, [Co (CN) 6] 3"" ~, [ Fe (cyclopentadienyl) 2] 0 +. As counterions for metal ions and cationic complexes, all Redox-inert anions X ~ are included, as will be described in more detail below, as counterions of the anionic complexes all Redox cations come into consideration. -M '+ rings, for example alkali metals or quaternary ammonium salts, such as Na +, K +, N (CH3) 4+, N (C4H9) 4+, C6H5CH2N (CH3) 3+ and others. An electrochromic signaling device is preferred, in which 0X2 means a residue of the formulas (I), (III). (IV), (V) or (Cl), wherein R2, R3, R4, R5, R and R, independently of each other, mean alkyl with 1 to 1 * 2 carbon atoms, alkenyl with 2 to 8 carbon atoms , cycloalkyl with 5 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms, R6 and R7, independently of each other, mean hydrogen, methyl, ethyl, methoxy, ethoxy, fluorine, chlorine , bromine, cyano, nitro, methoxycarbonyl or ethoxycarbonyl, R10, R11, R12, R13 and R14, R15, independently of each other, mean hydrogen or, when Z1 means a direct bond, they mean paired a bridge - (CH2) 2- , - (CH2) 3- or -CH = CH-, O R4; R5; and R8; R9 independently of each other, mean, paired, a bridge - (CH2) 2_ or - (CH2) 3-, when Z1 means a direct bond, and then R69 to R74, independently of each other, mean hydrogen, or alkyl with 1 up to 4 carbon atoms, E1 and E2 are equal and mean O, S, NR1 or C (CH3) 2o together form a bridge - - (CH2) 2-N-, R1 means alkyl with 1 to 12 carbon atoms, alkenyl with 2 to 4 carbon atoms, cycloalkyl with 5 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms, Z1 means a direct bond, -CH = CH-, -C ( CH3) = CH-, -C (CN) = CH-, -CSC- or -C = NN = CH-, Z2 means - (CH2) r_ or -CH2-C6H4-p-CH2-, r means a whole number , comprised between 1 and 6, R101 to R103, independently of each other, mean a remainder of the formulas: , 161 where R to R, 162, independently of one another, mean hydrogen, alkyl having 1 to 6 carbon atoms, alkoxy with 1 to 6 carbon atoms, halogen, cyano, nitro, bis- (alkyl having 1 to 4 carbon atoms) amino, tris- (alkyl with 1 to 4 carbon atoms) ammonium, alkoxycarbonyl, with 1 to 4 carbon atoms or COOH, or paired form, the adjacent residues together form a bridge -O- (CH-2) 2- 3, -O- (CH)? -2-0-, 16 NR163- (CH2) 2-3- or NR, iD3J- (CH2)? -2-O- or R 158 R 159 and / or R 161, 162 form a bridge -CH = CH-CH = CH-, which may be substituted by methyl, methoxy or chlorine, R163 means hydrogen or alkyl with 1 to 4 carbon atoms, E112 means 0, S or NR164, R 164 means hydrogen, alkyl with 1 up 18 carbon atoms, alkenyl with 2 to 12 carbon atoms, cycloalkyl with 4 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms and X ~ means a low inert colorless anion the Redox conditions, REDi means a remainder of an anionic Redox system of the formulas (X), (XI), (XII), (XIII), (XVI), (XVII), (XVIII) or (XX) R, 28B to R, 3J1i, R, 3J5a, RJB, R, 3J93, R, 446b, R, 533J and R, 5M4, mutually dependent, mean alkyl with 1 to 12 carbon atoms, alkenyl with 2 to 8 carbon atoms, cycloalkyl with 5 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms, 32 R 33 R 36 R 37 R0 R? R47, R8 R49 up R 52 R: 55 independently from one another, meaning hydrogen, methyl, ethyl, methoxy, ethoxy, fluorine, chlorine, bromine, cyano, nitro, methoxycarbonyl, ethoxycarbonyl or phenyl, R48 further means NR75R76, Z3 means a direct bond, a bridge - CH = CH- or = NN =, = Z4 = means a direct double bond, a bridge = CH-CH = or -N = N-, E3 to E5, E10 and E11 independently of each other, mean O, S, NR59 or C (CH3) 2, having however the same meaning E3 and E4, E6 to E9 are equal to each other and signify S, Se or NR59, E further means C = 0, R '59 R75 and R76, independently of each other, mean alkyl with 1 to 12 carbon atoms, alkenyl with 2 to 8 carbon atoms, cycloalkyl with 5 to 7 carbon atoms, aralkyl with 7 to 15 carbon atoms or aryl with 6 to 10 carbon atoms. and R means, furthermore, hydrogen or R 75 and R in the meaning of NR75R76 mean, together with the N- atom, with which they are linked, pyrrolidino, piperidino or morpholino, R61, R62, R67 and R68, independently of each other , they mean hydrogen, alkyl with 1 to 4 carbon atoms, methoxycarbonyl, ethoxycarbonyl or phenyl or, in a paired manner, form a bridge - (CH2) 3- or - (CH2) -, R63 to R65 mean hydrogen and v means a whole number Also preferred is an electrochromic device containing one of the compounds of formulas (la) through (Id), wherein 0X2 means one of the residues of formulas (II), (III), (IV) or (V), the link being verified with respect to the bridge member B through one of the remains R2 to R11 or, in the case where E1 or E2 means NR1, through R1 and the quoted residues mean then a direct link and all other residues have the preferred meaning indicated above.

REDi means one of the remains of the formulas (X), (XI), (XII), (XIII), (XVI), (XVII), (XVIII) or (XX), verifying the link with respect to the bridge member B through one of the residues R28 to R41, R46 to R56, R61, R62, R67, R68 or, when one of the residues E3 to E11 signifies NR59, they are verified through R59 and the residues quoted then mean a bond direct and all the rest have the preferred meaning previously indicated, and B means a bridge of the formulas - (CHR80) s- (CH2) n- (CHR80) s-, - (CHR80) s- (CH2) mo- (CH2) p- (CHR80), -, - (CHR80) s- (CH2) m- NR60- (CH2) p- (CHR80) s-, - (CHR80) s- (CH2) m-C6H4- (CH2) P- (CHR80) s-, - [0 (CH2) P] 0-0-, - [NR60- (CH2) P] or -NR60-, - (CHR80) s- (CH2) m-0C0-C6H4-C00- (CH2) p- (CHR80) s-, - (CHR80) s- (CH2 ) m-NHCO-C6H4-CONH- (CH2) p- (CHR80) s-, - (CHRBU) s- (CH2)? a-NHC0NH-C6H-NHC0NH- (CH2) p- (CHRBU) s-, - (CHR80) s_ (CH2) -OCO- (CH2) t-C00- (CH2) p- (CHR80) s-, - (CHR80) s- (CH2) m-NHC0- (CH2) t-CONH- (CH2 ) p- (CHR80) s_ - (CHR, 8B0U) s- (CH2) m-NHC0- (CH2) t-C0NH- (CH2) P- (CHR 8B0U), s-, 60 means methyl, ethyl, n-benzyl or phenyl, R80 means hydrogen, methyl, or ethyl, n means an integer from 1 to 10, m and p, independently of each other, mean an integer from 0 to 4, or means a number An integer from 0 to 2, s means 0 or 1, and t means an integer from 1 to 6. Also preferred is an electrochromic device containing mixtures of the above-mentioned electrochromic substances generally and preferably. Examples of such mixtures are (II) + (Cl) + (XVI), (II) + (IV) + (XII), (la) + (II) + (XVI), (la) + (Cl), without wishing to express any delimitation. Mixing ratios can vary within wide limits. These allow optimizing a desired color tone and / or optimizing the desired dynamics of the device. In the meanings of the abovementioned substituents, the alkyl radicals are, even in the modified state, such as, for example, 2-alkoxy or aralkyl radicals, preferably those with 1 to 12 carbon atoms, especially 1 to 8 carbon atoms, as long as it is not said otherwise. These can be straight chain or branched chain and, if appropriate, can carry other substituents such as alkoxy with 1 to 4 carbon atoms, fluorine, chlorine, hydroxy, cyano, alkoxycarbonyl with 1 to 4 carbon atoms or COOH. Cycloalkyl radicals are preferably those with 3 to 7 carbon atoms, especially 5 or 6 carbon atoms. The alkenyl radicals are preferably those with 2 to 8 carbon atoms, especially with 2 to 4 carbon atoms. Aryl moieties, even those in the arylalkyl moieties, are phenyl or naphthyl moieties, especially phenyl moieties. These can be substituted by one to three of the following substituents: alkyl with 1 to 6 carbon atoms, alkoxy with 1 to 6 carbon atoms, fluorine, chlorine, bromine, cyano, hydroxy, alkoxycarbonyl with 1 to 6 carbon atoms or nitro. Two contiguous residues can also form a ring. Means heterocyclic rings with 5 or 6 aromatic or quasi-aromatic members, optionally benzoanillated, especially imidazole, benzoim-idazole, oxazole, benzooxazole, thiazole, benzothiazole, indole, pyrazole, triazole, thiophene, isothiazole, benzoisothiazole, 1,3, 4- or 1, 2, 4-thiadiazole, pyridine, quinoline, pyrimidine, and pyrazine. These may be substituted by one to three of the following radicals: alkyl having 1 to 6 carbon atoms, alkoxy with 1 to 6 carbon atoms, fluorine, chlorine, bromine, cyano, nitro, hydroxy, mono- or di-alkylamino with 1 to 6 carbon atoms, alkoxycarbonyl with 1 to 6 carbon atoms, alkylsulfonyl with 1 to 6 carbon atoms, alkanoylamino with 1 to 6 carbon atoms, phenyl or naphthyl. Two contiguous residues can also form a ring. Electrochromic substances are known (Topics in Current Chemistry, Vol. 92, pages 1-44 (1980), Angew, Chem, 90, 927 (1978, Ad. Mater, 3, 225, (1991), DE-OS 3,917,323, J. Am. Chem. Soc. 117, 8528 (1995), JCS Perkin II 1990, 1777, DE-OS 4,435,211, EP-A 476,456, EP-A 476,457, DE-OS 4,007,058, J. Org. Chem. 57, 1849 (1992) and J. Am. Chem. Soc. -99, 6120, 6122 (1977)) or can be prepared analogously. The compounds of the formula (I) can be synthesized from yes known, for example according to the following scheme: The synthesis-dependent ions such as bromide are finally exchanged for Redox-inert ions. The electrochromic signaling device according to the invention contains at least one solvent, in which the electrochromic substances are dissolved, optionally a conductive salt and, if appropriate, other additives. The solvent can also be thickened in the form of a gel, for example by polyelectrolytes, porous solid products or nanoparticles with a large active surface. Suitable solvents are all Redox-inert solvents under the chosen tensions which can not dissociate electrophiles or nucleophiles or which do not react by themselves in the form of electrophiles or nucleophiles with sufficient intensity and which, in this way, could react with the radical-colored ions. Examples are propylene carbonate, β-butyrolactone, acetonitrile, propionitrile, glutaronitrile. methylglutaronitrile, 3,3'-oxydipropionitrile, hydroxypropionitrile, dimethylformamide, N-methylpyrrolidone sulfolane, 3-methylsulpholane or mixtures thereof. Preferred are propylene carbonate and mixtures thereof with glutaronitrile or with 3-methylsulfolane The electrochromic solution according to the invention can contain at least one inert conductive salt, especially when at least one of the substances of the Redox pair RED1 / OX2 is of nature However, the addition of a conductive salt can be avoided as inert conductive salts, the lithium, sodium and tetraalkylammonium salts, especially the latter, are suitable.The alkyl groups can have between 1 and 18 carbon atoms and can be the same or Tetrabutylammonium is preferred.

As anions of these salts, as well as anions X in the formulas (11) to (VI), (Cl), (CII) and (CV) to (CVII) in the metal salts come into consideration all the colorless, Redox-inert anions. Examples are tetrafluoroborate, tetraphenylborate, cyano-triphenylborate, tetramethoxybhorate, tetrapropoxybrate, tetraphenoxybutorate perchlorate, chloride, nitrate, sulfate, phosphate, methanesulfonate, ethanesulfonate, tetradecanesulfonate, pentadecane sulphonate, trifluoromethanesulfonate, perfluorobutane sulfonate, perfluorooctanesulfonate, benzenesulfonate, chlorobenzenesulfonate, toluenesulfonate, butylbenzenesulfonate, tere. -butylbenzenesulfonate. Dodecylbenzenesulfonate, trifluoromethylbenzenesulfonate, hexafluorophosphate, hexafluoroacetate, hexafluorosilicate, 7,8- or 7,9-dicarbanide-undecaborate (-1) or (-2), which are optionally substituted on the B and / or C atom by of one or two methyl, ethyl, butyl or phenyl groups, dodecahydrodicated carbonate (-2) or B-methyl-C-phenyl-dodecahydro-dicarbadodecaborate (- 1). The conductive salts are preferably used in the range of 0 to 1 mol / 1. As other additives, thickeners can be used to control the viscosity of the electroactive solution. This may have significance in order to avoid segregation, ie the formation of color occurrences in the form of strips or spots during prolonged operation of the electrochromic device in the connected state and to control the speed of discoloration after disconnection of the current. Suitable thickeners are all the compounds customary for this purpose, such as, for example, polyacrylate, polymethacrylate (Luctite L®), polycarbonate or polyurethane. As other additives for electrochromic liquids, they are considered to reinforce, if necessary, the protection against UV, UV absorbers. Examples are UVINUL® 3000 (2,4-dihydroxybenzophenone, BASF), SANDUVOR® 3035 (2-hydroxy-4-n-octyloxybenzophenone, Clariant), Tinuvin® 571 (2- (2H-benzo-triazol-2-yl) -6- dodecyl-4-methylphenol, Ciba); Cyasorb 24MR (2, 2 '-dihydroxy-4-methoxybenzophenone, American Cyanamid Company), UVINUL® 3035 (ethyl-2-cyano-3,3-diphenylacrylate, BASF), UVINUL® 3039 (2-ethylhexyl-2-cyano- 3,3-diphenylacrylate, BASF), UVINUL® 3088 (2-ethylhexyl-p-methoxycinnamate, BASF), CHIMASSORB® 90 (2-hydroxy-4-methoxy-benzophenone, Ciba). The last four are preferred. Mixtures of UV absorbers, for example of the last four mentioned, are also preferred. The mixture formed by UVINUL® 3039 (BASF) and by CHIMASSORB® 90 is preferred. The UV absorbers are used in the range of 0.01 to 2 mol / liter, preferably 0.04 to 1 mol / liter. The electrochromic solution contains electrochromic substances 0X2 and REDi, especially those of formulas (1) to (XX) and (Cl) to (CIV) respectively in a concentration of at least 10-4 moles / liter, preferably from 0.001 to 0.5 moles /liter. The total concentration of all the electrochromic substances contained is preferably below 1 mol / liter. For the operation of the electrochromic device according to the invention current is used. continuous constant, pulsed or varying in amplitude, for example that varies sinusoidally. The tension depends on the intensity of the desired color, especially, however, of the reduction or oxidation potentials of the 0X2 and REDi employed. Such potentials can be taken for example from the publications Topics in Current Chemistry, volume 92, pages 1-44, (1980) or Angew. Chem. 90, 927 (1978) or from the literature quoted therein. The difference of its potentials is a guideline value of the necessary voltage, however the electrochromic device can already be operated with. a lower voltage or also with a higher voltage. In many cases, for example when using OX2 = formula (II) or (IV) and REDi = formula (X), (XII), (XVI) or (XVII) or link through a bridge according to the formula (I ), especially according to the formulas (the) up to (Id), this potential difference, necessary for the operation, is <1 V. - Such electrochromic devices can therefore be fed in a simple manner with the current from silicon photovoltaic cells. When the voltage is disconnected, the electrochromic device according to the invention returns to its original state again. This extinction can be considerably accelerated if the segments or contacted plates are short-circuited. The signaling device can also be extinguished very quickly if several polar inversions of the voltage are carried out, possibly even with a simultaneous reduction of the voltage. By varying the thickness of the layer of the electrochromic device, the viscosity of the solution, electrochromic and / or the ability to diffuse or drift of the electrochromic substances can influence the times of connection and disconnection of the signaling device within of ample limits. In this way, for example, thin layers have shorter connection times than thick ones. Therefore, switchable devices can be constructed quickly and slowly and, thus, optimally adapted to the corresponding purposes of use. In the case of slow devices, especially signaling devices, a current or refreshment saving mode may be used for the maintenance of the displayed information in the connected state. After the establishment of the information to be displayed, for example by constant direct voltage or that is modified with high frequency or pulsating, of sufficient level it is switched to pulsating continuous voltage s variable of low frequency, the contact of the segments not being short-circuited during the phases in which the voltage is zero. This low frequency can be found, for example, in the range of 1 Hz or below this value, the connection and disconnection phases need not be of identical duration, but, for example, the disconnection phases can be clearly longer. Since during the pauses of the current in the non-short-circuited state, only slowly disappears at the color intensity of the displayed information, relatively short current pulses are sufficient to compensate again for these losses in the subsequent refreshment phase. In this way, an image free of spots with an almost constant color intensity is obtained, for which maintenance only a fraction of the current that would be required in the case of a permanent flow of current is required. The UV light absorber based on the nanoparticles according to the invention can be homogeneously dispersed in the electrochromic system, for example in the electrochromic solution. However, it can be distributed homogeneously in electrochromic stratified systems, which are located on the conductive layer. By way of example, such layers constituted by the solution in which the nanoparticles are dispersed and the electrochromic substance dissolved or dispersed can be spilled or applied. After removal of the solvent an electrochromic layer containing the nanoparticles is obtained. The nanoparticles can also be homogeneously distributed in a synthetic material or in a varnish, the synthetic material or the varnish being applied as a coating on at least one of the two plates or sheets. The nanoparticles can also be contained in the plates or in the sheets, especially when these plates or sheets are constituted by a synthetic material. All these forms of application of the nanoparticles can also be combined, that is to say that the nanoparticles are contained both in the electrochromic system and also in one of the. cited coatings and / or on plates or sheets. The electrochromic system or one of the said coatings of synthetic material or varnish or glass plates or plaques or sheets of synthetic material of the electrochromic device contains the UV light absorbers based on the nanoparticles according to the invention in a concentration of 0.001 to 30, preferably from 0.01 to 10% in atoms. The synthetic materials and varnishes can be, for example, polycarbonate, polyurethane, polyester, polyimide, polyamide, acrylates or polyacrylonitrile. The incorporation of the nanoparticles in such materials can be carried out according to conventional methods, for example according to WO-A 95/09 895, WO-A 92/21 315, EP-A 0 628 303. In addition to special types of types 1 and 2 mentioned above can be, for example, the following ones, which also constitute an object of the invention, when they are protected against UV light by means of nanoparticles. Type 1: (not azogado). In the area of light protection / light filter: windows for example for buildings, land vehicles, aircraft, trains, boats, glazing for roofs, self-cleaning roofs, glazing of greenhouses and winter gardens, light filters of any type; in the security / confidentiality sector: separation glass for example for space distributors, for example in offices, land vehicles, aircrafts, trains, glasses for protection against the sight, for example in ship counters, glass doors, glass for example for motorcycle or pilot helmets; in the design sector: glazing of ovens, microwave devices, other household devices, furniture. Type 1: (Azogado) Mirrors of any kind, for example for land vehicles, trains, especially flat, spherical, non-spherical mirrors and combinations thereof, for example spherical / non-spherical specular glazing in furniture. Type 2: Signaling devices of any type, for example, segment or matrix signaling devices, for example for watches, computers, electrical devices, electronic devices such as radios, amplifiers, televisions, CD players, etc., destination indicating devices in buses and trains, indicating devices for the departure of trains and aircraft in stations and airports, flat screens, all the applications that have been indicated in type 1 and 2, containing at least one switchable, static or variable signaling device, for example crystals separation, containing indications such as for example "please do not disturb", "counter out of service", for example automotive mirrors, containing indications of any kind, such as for example temperature indications, disturbances in the vehicle (for example oil temperature, open door), time, cardinal points, etc.

Examples Example 1 A cell was constructed according to figure 1. For this, two glass plates 1 and 2 were used, which were coated with ITO on one of the sides. On the other side they were provided with a layer containing Ce02 nanoparticles. The layer was applied in the following manner. First a solution of polyvinyl alcohol at 6% by weight and a dispersion of Ce02 at 7%, respectively in water, was prepared. The Ce02 nanoparticles were purchased from Rhodia, Frankfurt, and had a size distribution of 8 ± 2 nm. These solutions were mixed in the 1: 1 ratio. This mixture is a solution of polyvinyl alcohol at 4% by weight with a proportion in Ce02, corresponding to 20% by weight, based on the total proportion of solid matter. A mixture consisting of 97% light-cured epoxy glue DELO-Katiobond 4594 was applied (DÉLO Industrieklebstoffe, Landsberg) and 3% of glass balls with a diameter of 200 μm, in an annular shape 3, on the side coated with ITO of the glass plate 1 in such a way that an opening 4 was left free with a width of 2 mm. Now the glass plate 2 was placed on the glue macaroni in such a way that the ITO layers of both plates 1 and 2 were mutually directed and a geometry was formed as indicated in figure 1. The hardening of glue it was carried out by irradiation for 10 minutes with daylight in the vicinity of a window and then for 20 minutes at 105 ° C without illumination. A capsule was filled, under a nitrogen atmosphere, with a solution that was 0.02 molar in the electrochromic compound of the formula in anhydrous polycarbonate, free of oxygen. The cell was then placed vertically in the capsule, under a nitrogen atmosphere, in such a way that the orifice 4 was below the level of the liquid. The capsule with the cell was placed in a desiccator. This was subjected to a vacuum of 0.05 mbar and then carefully ventilated with nitrogen. During ventilation the electrochromic solution ascended through hole 4 in the cell and filled the entire volume with the exception of a small bubble. The cell was removed from the solution, cleaned in hole 4 under a nitrogen atmosphere, by rubbing with a paper tissue and closed with the photochemically hardenable acrylate adhesive DELO-Photobond® (DÉLO Industrieklebstoffe, Landsberg). It was then irradiated, under a nitrogen atmosphere, with the Lampe DELOLUX® 03 lamp (DÉLO lndustrieklebstoffe, Landsberg) which was at a distance of 8 cm from hole 4, at room temperature and hardened overnight under a nitrogen atmosphere. By applying a voltage of 0.9 V on the two plates 1 and 2 the cell was rapidly colored dark greenish blue. By disconnection of the voltage and short-circuiting of the contacts the coloration quickly disappeared again.

Example the (comparative).

A cell was constructed as in Example 1, however, glass plates that were only coated with ITO were used.

Light stability test.

For the light stability test, cells according to Example 1 were irradiated, together with reference cells according to the example, with a working voltage of 0.9 V in a Suntest CPS + test device from Atlas, Linsengericht Altenhaßlau equipped with the filter scale A and with an irradiation power of 765 V / m2. Before the start of the irradiation, the absorption spectra of each cell in the connected state (0.9 V) and in an unconnected state (0 V) were collected with an absorption photometer Cary AG (Firma Varian, Darmstadt). Irradiation was verified at intervals respectively multiplied by at least 2 (30 minutes, 1 hour, 2 hours, 4 hours, 8 hours, 16 hours) such that each sample had finally irradiated a total of 183.5 hours. After each irradiation interval, absorption measurements were again carried out in the connected and unconnected state. From these measurements, differential spectra were formed, respectively representing the current spectra in connected and not connected state minus the starting spectra. The deterioration of the cell was defined by means of the decrease of the electrochromic trajectory. This means the decrease of the transmission variation at a certain wavelength. The wavelength maximums at 605 nm were evaluated. In the evaluation of the differential spectra, it must be taken into account that the variations of the transmission in the non-connected state also appear in the differential spectra of the connected state and must be subtracted from them. In the following table, the decrements of the electrochromic trajectory during the cumulative irradiation time for the cell according to the invention with nanoparticles (according to example 1) and as a comparison thereto which correspond in the absence of nanoparticles (according to the example ). The comparison between cells without nanoparticles shows a strong increase in stability.

The deterioration of the cell (20% less electrochromic trajectory) was determined after 78 hours. Faced with the unprotected state, this means an improvement by a factor of 250. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (24)

1. An electrochromic device, characterized in that it is protected against ultraviolet (UV) light by means of nanoparticles.

2. An electrochromic device that is constituted by two plates or sheets, at least one of which is transparent and which are provided with a conductive layer on the sides directed to each other, at least one of the conductive layers being transparent, and are joined to each other with a seal ring, a volume in which an electrochromic medium is defined by means of the plates or sheets and the sealing ring, characterized in that the electrochromic device is protected from UV light by means of nanoparticles.

3. The electrochromic device according to claim 2, characterized in that at least one of the two protective layers is coated with an electrochromic layer.

4. The electrochromic device according to claim 2, characterized in that the electrochromic means represents an electrochromic solution.

5. The electrochromic device according to one or more of claims 1 to 4, characterized in that the nanoparticles are contained in the electrochromic system and / or are applied to at least one of the two plates or sheets and / or are incorporated in at least one of the two plates or sheets, these sheets or plates being transparent.

6. The electrochromic device according to one or more of claims 1 to 4, characterized in that the nanoparticles are dispersed in the electrochromic system.

7. The electrochromic device according to one or more of claims 1 to 4, characterized in that the nanoparticles are contained in a coating that has been applied to at least one of the two plates or sheets.

8. The electrochromic device according to one or more of claims 1 to 4, characterized in that the nanoparticles have been introduced into at least one of the two plates or sheets.

9. The electrochromic device according to one or more of claims 1 to 8, characterized in that the nanoparticles are constituted by materials based on SiC, AISi, Fe203, Fe30, Ti0, ZnO, GaP, Ce02, ZnS, Sn02, SiyGe? - and, WxM ?? - x03, NiO, Bi203, ln203, Hf02, BaTi03, CaTi03, Ge, AIP, GaN, where 0.7 < and < 1 and 0 < x < 1.

10. The electrochromic device according to one or more of claims 1 to 8, characterized in that the nanoparticles are constituted by materials based on SiC, AISi, silver halide emulsion layer, Fe203, Fe3? 4, Ti02, ZnO, Ce02 , WxM ?? _ x03, BaTi03, CaTi03, where O < x < 1.

11. The electrochromic device according to one or more of claims 1 to 10, characterized in that the nanoparticles are preponderantly composed of silicon and / or solid compounds, in which the silicon is present in stoichiometric excess.

12. The electrochromic device according to one or more of claims 1 to 11, characterized in that the nanoparticles have an average diameter of less than 500 nm, preferably < 100 nm, more preferably < 50 nm, more preferably < 20 nm.

13. The electrochromic device according to one or more of claims 1 to 11, characterized in that the noparticles have a spherical or almost spherical shape.

14. The electrochromic device according to one or more of claims 1 to 13, characterized in that the nanoparticles have a core-shell structure.

15. The electrochromic device according to one or more of claims 1 to 14, characterized in that the envelope is organically modified.

16. The electrochromic device according to one or more of claims 1 to 11, characterized in that the solid compounds, in which silicon is present in stoichiometric excess, are compounds of the formula SixZ? _x, in which 0.5 < x < 1 and Z means C, N, O, Ge, Ca, Ba or Sr or mixtures thereof.

17. Electrochromic device according to one or more of claims 1 to 16, characterized in that the solid compounds, in which the silicon is present in stoichiometric excess, have a core-shell structure.

18. The electrochromic device according to one or more of claims 1 to 17, characterized in that the nanoparticles are constituted by a core of titanium nitride and by a silicon shell, the volume ratio of silicon being on average at least 30% based on the nanoparticles.

19. The electrochromic device according to one or more of claims 1 to 18, characterized in that the nanoparticles have a particle size distribution with a maximum semiamplitude of 40 nm, preferably of 30 nm, more preferably of 20 nm.

20. The electrochromic device according to one or more of claims 1 to 19, characterized in that the nanoparticles are coated with an oxide layer with a thickness of 1 to 300 nm.

21. The electrochromic device according to one or more of claims 1 to 20, characterized in that the shell represents an oxide of the material of the nanoparticles or is constituted by another material, transparent in the visible, whose diffraction index is similar to that of the nanoparticles .

22. The electrochromic device according to one or more of claims 1 to 21, characterized in that particles of oxides and / or metal nitrides absorbing in the red spectral range of 600 nm have been mixed with these nanoparticles. ? < 700 nm, with greater intensity than in the blue-green spectral range 400 nm < ? < 550 nm.

23. The electrochromic device according to claim 22, characterized in that the additional particles are constituted by titanium nitride with an average diameter of the particles of up to 400 nm, preferably from 1 to 100 nm, particularly preferably from 1 to 50 nm , or are agglomerated from these primary particles of titanium nitride.

24. The electrochromic device according to claim 23, characterized in that the additional particles are aluminum and sodium silicates.