Crosslinked gel formulation

Abstract

To provide a novel gel medium comprising: at least one non-aqueous solvent; a crosslinked polymer resulting from the reaction of a polyfunctional polymer containing at least two carboxyl moieties capable of undergoing crosslinking reactions and a crosslinking agent chosen from a polycarbodiimide or a non-toxic polyaziridine; such gel medium being suitable for manufacturing articles such as batteries or electrochromic devices or photochromic devices.SOLUTION: The present invention relates to a gel medium comprising: at least one non-aqueous solvent; and a crosslinked polymer resulting from the reaction of a polyfunctional polymer containing at least two carboxyl moieties capable of undergoing crosslinking reactions, wherein the polyfunctional polymer has a weight average molecular weight from 2,000 g / mol to 3,000,000 g / mol, with a crosslinking agent chosen from a polycarbodiimide or a polyaziridine.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a novel gel medium containing at least one non-aqueous solvent; a crosslinked polymer obtained by reaction of a multifunctional polymer containing at least two carboxyl sites capable of undergoing a crosslinking reaction with a crosslinker selected from polycarbodiimides or non-toxic polyaziridines; such gel medium is suitable for the manufacture of articles such as batteries or electrochromic or photochromic devices. [Background technology]

[0002] Electrochromism is a well-known physical phenomenon observed in a specific class of compounds that reversibly change color when a voltage is applied: these materials undergo a reversible change in optical properties upon oxidation and reduction.

[0003] Electrochromic systems can be used in a variety of applications. For example, in the ophthalmology field, unlike photochromic lenses that passively darken under UV irradiation and take a certain time to fade again when UV irradiation is stopped, electrochromic lenses allow the user to actively control the darkening of the lens under certain lighting conditions to protect the eyes and to quickly switch when these conditions change. Electrochromic glass is also used in the manufacture of "smart windows" or "rearview mirrors". Electrochromic devices are usually manufactured from electrochromic compositions that contain either a liquid or solid electrolyte in addition to the electrochromic compound.

[0004] The liquid electrolyte is usually introduced into a pre-assembled functional electrochromic cell of an electrochromic device by surface capillarity, for example, two small openings are placed at opposite corners when filling is performed at atmospheric pressure. When the liquid electrolyte comes into contact with one of the openings, it rises up the cavity inside the cell. However, this method limits the size of the device and increases the risk of air bubbles, as it becomes more difficult to rise due to the increasing potential energy of the electrolyte as the filling proceeds. Furthermore, the layer containing the liquid electrolyte may exhibit low mechanical resistance to deformation when introduced into an electrochromic device. Conversely, it is very difficult to assemble solid electrolytes to rigid electrode substrates due to their non-deformable nature. This limits the electronic contact between the electrode substrate and the electrochromic material, resulting in colorless areas in the colored state, which is more pronounced in the case of large-area electrochromic devices. Furthermore, another disadvantage of solid electrolytes is their low ionic conductivity and slow or non-uniform color change.

[0005] Very similar problems can be encountered in the case of photochromic systems, either liquid or solid state.

[0006] A passive photochromic device is one that contains a photochromic dye whose absorbance depends only on the presence or absence of UV light. The photochromic dye is typically incorporated into an ophthalmic lens by an absorption (or impregnation) or coating process that is not suitable for ophthalmic substrates. Such dyes typically exhibit rapid activation (i.e., coloration), but it usually takes minutes or even tens of minutes for the photochromic device to return to its inactive (i.e., colorless) state.

[0007] In the case of optical lenses, this slow deactivation (i.e. fading) is problematic since the user of photochromic glasses is forced to remove them when moving suddenly from a bright environment to a dark one. The same problem can occur in the case of other optical articles, where slow deactivation leads to long waiting times that are unsatisfactory for the end user. The deactivation speed of photochromic dyes depends not only on their chemical structure but also in no small part on the matrix in which they are present. It has therefore been possible to show that the fading of photochromic dyes is virtually always faster in liquid media than in solid media. However, the use of liquid media has several drawbacks, such as defects occurring after assembly in the final article and a low mechanical resistance to deformation.

[0008] Therefore, it is necessary to obtain a strong cohesive medium in order to avoid deformation of the layer or composition containing the active dye, i.e. deformation of the electrochromic layer or composition in an electrochromic device during handling, or deformation of the photochromic layer or composition in a photochromic device during handling, while still ensuring the desired ionic conductivity in the system containing the active dye. This is particularly important in the case of flexible and therefore deformable devices, such as goggles, for example ski goggles. Otherwise, optical defects such as white defects or air bubbles may occur when the device is activated, which are considered unaesthetic by the user.

[0009] A similar need to provide an electrolyte system that exhibits both good ionic conductivity and resistance to deformation is encountered in batteries, where all-solid-state electrolytes are rarely of practical use due to their typically low ionic conductivity.

[0010] Since gel or semi-solid electrolytes are easier to handle than liquid electrolytes and have better interactions with the electrodes than solid electrolytes (due to their tackiness and / or adhesiveness), their use avoids the above-mentioned concerns and opens up new possibilities for the industrialization stage.

[0011] Electrochromic devices based on gel electrolytes or all-in-one gels are mentioned in the scientific review All-in-One Gel-Based Electrochromic Devices: Strengths and Recent Developments (Alesanco Y. et al;. Materials (Basel). 2018; 11(3): 414. Published 2018 Mar 10) and several have been fabricated.

[0012] In particular, in the context of transparent materials that can be adapted to any surface (i.e. flexible), electrochromic devices based on all-in-one gels have been proven to meet the requirements of flexibility due to two main advantages: First, they are compatible with plastic electrode substrates (such as tin-doped indium oxide (ITO) / PET) since the assembly process does not involve high temperature steps. Second, the high viscosity and / or self-supporting characteristics of the gel compared to liquid electrochromic mixtures avoid the risk of leakage and provide a more regular distribution (thickness) of the electrochromic mixture over the entire device area, thereby providing better uniformity and avoiding short circuits between electrode substrates that are prone to occur in flexible and therefore deformable systems.

[0013] Among the possible ways of obtaining such gels, the authors mention UV photopolymerization or ionic crosslinking of polyvinyl alcohol with borax, the latter carried out in water. The main drawback is that borax is not soluble in the usual non-aqueous solvents such as propylene carbonate used in most electrochromic formulations and therefore cannot be used.

[0014] Another drawback is that although UV photopolymerization is an effective way to obtain gels, it requires the presence of photoinitiator molecules to initiate the polymerization, which can have undesirable interactions with the electrochromic dyes and degrade their electrochromic properties.

[0015] The following documents US Patent No. 7,001,540, US Patent No. 8,928,966, and US Patent No. 6,057,956 all relate to crosslinked electrochromic formulations. The crosslinked polymer is obtained between a preferred crosslinker, such as one with isocyanate or isothiocyanate functionality, and any prepolymer with hydroxyl (or any reactive group with active hydrogen, such as thiol, hydroxyl, acetoacetyl, urea, melamine, urethane, etc.). A wide range of polymers with hydroxyl groups are available, such as polyols containing reactive hydroxyl (OH) groups. Thus, said reactive hydroxyl groups can react with isocyanate (NCO) groups to form polyurethanes. The resulting crosslinked polymer is then subjected to a thermal curing process to obtain the final gel, or cured at room temperature for extended periods of time.

[0016] The main drawback is the use of isocyanates, since the use of crosslinkers based on isocyanates is limited by the high toxicity of the chemistry.

[0017] In the absence of a crosslinker in the concentrated polymer composition, a layer is obtained with a sufficient amount of polymer to achieve a solid state, but attempts to achieve good mechanical properties fail. Thus, after bending the sample, over time, flow of the formulation from the pinch zone may be observed. Even if the composition is very viscous, the layer does not maintain a uniform thickness.

[0018] Therefore, there is a need to obtain an improved gel for use as a transparent medium for forming high quality articles, in particular high quality batteries or electrochromic or photochromic devices, said gel being made of low toxicity components, being flexible when bent, and being compatible with other components forming the article without disturbing its properties, while the preparation process of such a gel can be carried out fairly quickly, in less than one hour, at relatively low temperatures, preferably less than 150°C. Summary of the Invention [Means for solving the problem]

[0019] After conducting extensive research, according to a first aspect, the inventors have discovered a gel medium comprising: at least one non-aqueous solvent present in said gel medium in an amount of at least 30% by weight relative to the total weight of the gel, more preferably at least 50% by weight relative to the total weight of the gel; A crosslinked polymer, a multifunctional polymer comprising at least two carboxyl moieties capable of undergoing a crosslinking reaction, the multifunctional polymer having a molecular weight between 2,000 g / mol and 3,000,000 g / mol, preferably between 10,000 and 1,000,000 g / mol, more preferably between 25,000 g / mol and 400,000 g / mol; a crosslinking agent selected from polycarbodiimides or non-toxic polyaziridines; a crosslinked polymer obtained by the reaction of A gel medium is provided which contains:

[0020] Preferably, said polyfunctional polymer has an acid value of 1 to 50 mg KOH / g, preferably 3 to 40 mg KOH / g, preferably 4 to 15 mg KOH / g.

[0021] The gel medium is particularly useful as an electrolyte in articles such as batteries or electrochromic or photochromic devices.

[0022] According to one embodiment, the gel medium further comprises a dye or a mixture of dyes, preferably independently selected from photochromic dyes, electrochromic dyes, dichroic dyes, and fixed color dyes, more preferably selected from photochromic dyes and electrochromic dyes.

[0023] Another object of the invention is a device comprising a gel medium as defined in the first aspect, said gel medium comprising: (a) external to the device; said at least one non-aqueous solvent; - said at least one optional dye, preferably chosen from at least one photochromic dye or at least one electrochromic dye; - said multifunctional polymer comprising at least two carboxyl moieties capable of undergoing a crosslinking reaction, said multifunctional polymer having a molecular weight of 2,000 g / mol to 3,000,000 g / mol, preferably 10,000 to 1,000,000 g / mol, more preferably 25,000 g / mol to 400,000 g / mol; - said crosslinking agent being chosen from polycarbodiimides or non-toxic polyaziridines; forming a liquid composition by mixing; (b) placing the liquid composition of step (a) into the device and polymerizing the multifunctional polymer and the polycarbodiimide or polyaziridine, thereby forming a crosslinked polymer and forming a gel medium in which the compound and solvent are retained in a matrix containing the crosslinked polymer; It is a device formed by:

[0024] Preferably, said polyfunctional polymer has an acid value of 1 to 50 mg KOH / g, preferably 3 to 40 mg KOH / g, preferably 4 to 15 mg KOH / g.

[0025] The device is for example a battery or an electrochromic or photochromic device, preferably the device is an electrochromic or photochromic device and is selected from optical articles such as optical lenses, optical filters, attenuators, windows, visors, mirrors (such as rearview mirrors) and displays, preferably an optical lens, more preferably an ophthalmic lens or an optical lens for goggles.

[0026] Another object of the present invention is to provide a multifunctional polymer comprising at least two carboxyl moieties capable of undergoing a crosslinking reaction, the multifunctional polymer having a molecular weight between 10,000 g / mol and 3,000,000 g / mol, preferably between 30,000 and 1,000,000 g / mol, more preferably between 50,000 g / mol and 400,000 g / mol; - a crosslinking agent selected from polycarbodiimides or non-toxic polyaziridines for the in situ preparation of a gel medium that acts as an electrolyte in said device, in order to obtain a medium of high cohesion so that deformation of the medium is limited or strongly reduced upon deformation of the device; This relates to the use of mixtures of

[0027] Preferably, said polyfunctional polymer has an acid value of 1 to 50 mg KOH / g, preferably 3 to 40 mg KOH / g, preferably 4 to 15 mg KOH / g.

[0028] Gel medium As used herein, "gel" refers to a semi-solid that can have properties ranging from soft and weak to hard and tough. The gel is defined as a substantially dilute crosslinked system or polymer that does not exhibit flowability at steady state.

[0029] The gels of the invention have the advantage that they have mechanical strength, in other words they are self-supporting.

[0030] The gel of the present invention is not a hydrogel (i.e., it is not a gel in which the swelling agent is water). In other words, the gel does not contain water. It is devoid of water.

[0031] The gel medium comprises a non-aqueous solvent, preferably said solvent is present in said gel medium at least 30% by weight based on the total weight of the gel, more preferably at least 50% by weight based on the total weight of the gel.

[0032] The gel comprises a crosslinked polymer resulting from the reaction of a multifunctional polymer containing at least two carboxyl sites with a crosslinking agent.

[0033] Crosslinked polymers: Multifunctional polymers containing at least two carboxyl moieties Chemical cross-linking is a process that links polymer chains by covalent bonds to form a three-dimensional network that reduces the flexibility of the structure.

[0034] Multifunctional polymers containing at least two carboxyl sites useful in the present invention contain two or more functional or reactive groups.

[0035] As used herein, the term "polymer" refers to homopolymers (eg, prepared from a single monomer type), copolymers (eg, prepared from at least two monomer types), and graft polymers.

[0036] Multifunctional polymers that contain at least two carboxyl sites can take on any number of different structures or geometries, such as "branched," "linear," "forked," "multi-branched," or "multi-armed," "dendrimer," "comb-shaped," etc.

[0037] "Branched" in reference to the shape or overall structure of a polymer refers to a polymer having two or more polymer "arms" extending from a branch point. A branched polymer can have two polymer arms, three polymer arms, four polymer arms, six polymer arms, eight polymer arms, or more. A subset of branched polymers are multi-arm polymers, i.e., polymers having three or more arms extending from a central core.

[0038] Without wishing to be bound by theory, it is believed that the lack of steric hindrance between the arms of a multi-arm polymer allows for efficient cross-linking by the cross-linking agent, and therefore it is preferred that the arms of a multi-arm polymer are sufficiently spaced apart to avoid steric hindrance of the carboxyl moieties located within said arms.

[0039] The term "dendrimer" is intended to include, but is not limited to, a molecular structure having an inner core, layers (or generations) of repeating units attached to and extending from the inner core, and an outer surface of terminal groups attached to the outermost generation, each layer having one or more branch points. Dendrimers have a regular dendrimer or "starburst" molecular structure.

[0040] "Branch point" refers to a branching point containing one or more atoms at which a polymer or linking group splits or branches from a linear structure into one or more additional polymer arms. As used herein, the term "functional group" or any synonym thereof is intended to encompass protected and unprotected forms thereof.

[0041] A functional group in "protected form" refers to a functional group bearing a protecting group. As used herein, the term "functional group" or any synonym thereof is meant to encompass protected forms thereof.

[0042] Terms such as "multifunctional" or "polyfunctional" in defining a polymer refer to a polymer that includes at least two functional groups, which may be the same or different.

[0043] Multifunctional polymers useful in the present application may have at least two carboxyl sites capable of undergoing a crosslinking reaction, as well as at least one reactive group such as, but not limited to, allyl, vinyl, (meth)acrylate, thiol, hydroxyl, isocyanate, epoxy, episulfide, amine, silane, and / or imine, or any combination thereof.

[0044] In some embodiments, and by way of non-limiting illustration, the multifunctional polymer may have at least two carboxyl sites capable of undergoing a crosslinking reaction, as well as (meth)acrylate groups and at least one additional group that is an allyl, vinyl, epoxy, silane, or any combination thereof.

[0045] The multifunctional polymer containing at least two carboxyl moieties has a molecular weight of 2,000 g / mol to 3,000,000 g / mol, preferably 10,000 to 1,000,000 g / mol, more preferably 25,000 g / mol to 400,000 g / mol.

[0046] As used herein, molecular weight values ​​of polymers, such as weight average molecular weight (Mw) and number average molecular weight (Mn), are determined by gel permeation chromatography using appropriate standards, such as polystyrene standards, in the presence of an appropriate eluent, such as tetrahydrofuran. In some instances, and where noted, nuclear magnetic resonance (NMR) spectroscopy, such as 1H NMR, is used to determine Mn values.

[0047] Preferably, said multifunctional polymer comprising at least two carboxyl sites has an acid value of 1-50 mg KOH / g, preferably 3-40 mg KOH / g, preferably 4-15 mg KOH / g.

[0048] Unless otherwise indicated, all ranges disclosed herein should be understood to encompass all subranges subsumed therein. For example, a stated range of "1 to 10" should be considered to include all subranges between a minimum value of 1 and a maximum value of 10 (inclusive), i.e., all subranges beginning with a minimum value of 1 or more and ending with a maximum value of 10 or less, such as, but not limited to, 1 to 6.1, 3.5 to 7.8, and 5.5 to 10.

[0049] The term "acid number" as used herein is defined as the mass of potassium hydroxide (KOH, mg) required to neutralize 1 g of polycondensate and is measured by direct titration with a standard ethanolic potassium hydroxide solution.

[0050] Unless expressly stated otherwise, the term "acid equivalent" as used herein, such as with respect to multifunctional polymers containing at least two carboxyl sites, means "carboxylic acid equivalent" and is determined by determining the molecular weight or average molecular weight and the average number of carboxylic acid groups per molecule, such as by NMR analysis, and calculating the acid equivalent by dividing the molecular weight by the number of carboxylic acid groups per molecule.

[0051] Multifunctional polymers containing at least two carboxyl sites useful in the present invention can be selected from carboxylic acid functional polyesters, carboxylic acid functional polyethers, carboxylic acid functional polyurethanes, carboxylic acid functional polyacrylates, carboxylic acid functional polymethacrylates, carboxylic acid functional polyvinyl acetate copolymers, combinations thereof, or reaction products or copolymers thereof.

[0052] The multifunctional polymer can be selected or prepared according to art-recognized methods.

[0053] In some embodiments, and for purposes of non-limiting illustration, carboxylic acid functional polyesters, which may be selected as carboxylic acid functional polymers (or multifunctional polymers), are prepared by reacting a carboxylic acid functional material (and / or its cyclic anhydride and / or its ester) having a carboxylic acid functionality (or available carboxylic acid functionality, such as in the case of cyclic anhydrides and carboxylic acid esters) of at least 2 with a polyol having a hydroxy functionality of at least 2. The molar equivalent ratio of carboxylic acid groups to hydroxy groups of the reactants is selected such that the resulting polyester has hydroxyl functionality and the desired molecular weight.

[0054] Examples of polyfunctional carboxylic acids useful in the preparation of carboxylic acid functional polyesters that can be selected as the carboxylic acid functional material of the curable photochromic composition of the present invention include, but are not limited to, polyfunctional carboxylic acids such as benzene-1,2,4-tricarboxylic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid, endobicyclo-2,2,1,5-heptyne-2,3-dicarboxylic acid, tetrachlorophthalic acid, cyclohexanedioic acid, succinic acid, isophthalic acid, terephthalic acid, azelaic acid, maleic acid, trimesic acid, 3,6-dichlorophthalic acid, adipic acid, sebacic acid, and the like (optionally including the appropriate cyclic anhydrides and / or esters thereof).

[0055] Examples of polyols that can be used to prepare carboxylic acid functional polyesters that can be selected as the carboxylic acid functional polymers of the curable photochromic compositions of the present invention include, but are not limited to, glycerin, trimethylolpropane, trimethylolethane, trishydroxyethyl isocyanurate, pentaerythritol, ethylene glycol, propylene glycol, trimethylene glycol, 1,3-, 1,2-, and 1,4-butanediol, pentanediol (including, but not limited to, 1,5-pentanediol), and the like. and the like polyols, such as 1,6-hexanediol, 4,4'-(propane-2,2-diyl)dicyclohexanol, 4,4'-methylenedicyclohexanol, neopentyl glycol, 2,2,3-trimethylpentane-1,3-diol, 1,4-dimethylolcyclohexane, 2,2,4-trimethylpentanediol, 4,4'-(propane-2,2-diyl)diphenol, 4,4'-methylenediphenol, and the like.

[0056] In some embodiments, a carboxylic acid functional polyester is selected that includes or is a carboxylic acid functional oligomeric, branched, or hyperbranched polyester that contains at least three terminal carboxylic acid groups. Carboxylic acid functional oligomeric, branched, or hyperbranched polyesters can be prepared according to art-recognized methods, such as from the reaction of a polyol having at least three hydroxyl groups with a cyclic carboxylic acid ester, which in some embodiments includes the formation of a hydroxyl functional polyester intermediate that is subsequently modified to contain carboxylic acid groups. Examples of polyols from which the carboxylic acid functional oligomeric, branched, or hyperbranched polyesters can be prepared include, but are not limited to, glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, diglycerol (such as α,α'-diglycerol), di(trimethylolethane), di(trimethylolpropane), di(pentaerythritol), and combinations of two or more thereof. Examples of cyclic carboxylic acid esters that can be used as starting materials for preparing carboxylic acid functional oligomeric or branched or hyperbranched polyesters include, but are not limited to, lactones having 4 to 8 atoms in a cyclic ring in which the ester oxygen and the carbonyl carbon are directly bonded to each other, such as β-propiolactone, γ-butyrolactone, δ-valerolactone, δ-valerolactone, ε-caprolactone, and combinations of two or more thereof.

[0057] According to some embodiments, when the preparation of a carboxylic acid functional oligomeric or branched or hyperbranched polyester involves the formation of a hydroxyl functional polyester intermediate, the hydroxyl functional polyester intermediate can be modified to contain a carboxylic acid functionality by reaction with a cyclic anhydride, such as, but not limited to, succinic anhydride.

[0058] Commercially available examples of polyols that can be used to prepare the carboxylic acid functional polyesters of the compositions of the present invention include, but are not limited to: Linear aliphatic polyester polyols include, but are not limited to, STEPANOL PC polyester polyols available from Stepan Company; The following polyols are available from DIC Corporation: OD-X-286, OD-X-102, OD-X-355, OD-X-2330, OD-X-240, OD-X-668, OD-X-21068, OD-X-2547, OD-X-2420, OD-X-2523, OD-X-2555, and OD-X-2560 polyester polyols; OD-X-2155 and OD-X-640 polycaprolactone diols; and OD-X-2586 triol. The following polyols are commercially available from MilliporeSigma: polycaprolactone polyol with CAS number 36890-68-3; triol with CAS number 37625-56-2. The following polyols are commercially available from TriiSO: PERSTORP BOLTORN H2004 hyperbranched polyester polyol; and INGEVITY CAPA polycaprolactone polyol.

[0059] In some embodiments, and for purposes of non-limiting illustration, carboxylic acid functional polyethers are prepared by first preparing a polyether intermediate having hydroxyl functional groups, and then modifying the polyether intermediate to include carboxylic acid groups.

[0060] In some embodiments, and for non-limiting illustrative purposes, polyether intermediates can be prepared by ring-opening polymerization of cyclic ethers or mixtures of cyclic ethers, such as, but not limited to, alkylene oxides and / or tetrahydrofuran, using an acid or base catalyst with a polyhydric initiator or mixtures of polyhydric initiators. Non-limiting examples of polyhydric initiators include polyols as previously described herein. Exemplary alkylene oxides include ethylene oxide, propylene oxide, butylene oxide, amylene oxide, styrene oxide, and halogenated alkylene oxides, such as trichlorobutylene oxide. Examples of polyether polyols include, but are not limited to, poly(tetrahydrofuran)diol, also known as poly(tetramethylene ether)glycol.

[0061] In some embodiments, and for purposes of non-limiting illustration, carboxylic acid functional polyurethanes are prepared by first forming a polyurethane intermediate having hydroxyl or isocyanate functionality, and then modifying the polyurethane intermediate to include carboxylic acid groups. The polyurethane intermediate can be prepared according to art-recognized methods, such as, but not limited to, the reaction of a polyol, such as a diol, with a polyisocyanate, such as a diisocyanate. The polyols and polyisocyanates that can be used to prepare the polyurethane intermediate can, in some embodiments, be selected from the classes and examples of polyols and polyisocyanates previously described herein.

[0062] The hydroxyl functional polyurethane intermediate can be modified to include carboxylic acid functionality according to art-recognized methods. In some embodiments, the hydroxyl functional polyurethane intermediate is reacted with a cyclic anhydride, such as, but not limited to, succinic anhydride, to form a carboxylic acid functional polyurethane. In some further embodiments, the hydroxyl functional polyurethane intermediate is reacted with an isocyanate functional carboxylic acid ester, such as, but not limited to, alkyl 3-isocyanatopropanoate, and then subjected to art-recognized post-treatment procedures to form a carboxylic acid functional polyurethane. The isocyanate functional polyurethane intermediate can be modified to include carboxylic acid functionality according to art-recognized methods. In some embodiments, the isocyanate functional polyurethane intermediate is reacted with a hydroxyl functional carboxylic acid ester, such as, but not limited to, an appropriate carboxylic acid ester of 3-hydroxypropionic acid, to form a carboxylic acid ester functional polyurethane. In some embodiments, the carboxylic acid ester functional polyurethane is converted to a carboxylic acid functional polyurethane by undergoing art-recognized post-treatment procedures.

[0063] In some embodiments, and for purposes of non-limiting illustration, the multifunctional polymer can be selected from copolymers prepared from (meth)acrylic acid monomers or C1-C4 substituted (meth)acrylic acid monomers and at least one ethylenically unsaturated organic carboxyl monomer containing 3-9 carbon atoms and at least one carboxyl group, such as poly(acrylic acid-co-maleic acid), poly(acrylic acid-co-fumaric acid), poly(acrylic acid-co-crotonic acid).

[0064] As used herein, the terms "(meth)acrylate" and similar terms such as the term "(meth)acrylic acid ester" refer to methacrylate and / or acrylate. The term "(meth)acrylic acid" as used herein refers to methacrylic acid and / or acrylic acid.

[0065] Examples of such ethylenically unsaturated organic carboxyl monomers include, but are not limited to, succinic acid or its substitutes, 3-butenoic acid; 6-heptenoic acid; 6-methyl 6-heptenoic acid; 2-methyl 6-heptenoic acid; 3-methyl 6-heptenoic acid; 3-ethyl 6-heptenoic acid; 5-methyl 6-heptenoic acid; 4-methyl 6-heptenoic acid; 6-octenoic acid; 2-propyl 6-heptenoic acid; and 2,4-dimethyl 6-heptenoic acid; and combinations of two or more thereof.

[0066] Examples of such commercially available copolymers that can be used with the gel medium of the present invention include, but are not limited to, poly(acrylic acid-co-maleic acid) from SigmaAldrich or Carbosynth.

[0067] The multifunctional polymer may be selected from copolymers prepared from (meth)acrylic acid monomers or C1-C4 substituted (meth)acrylic acid monomers and at least one C1-C12 alkyl (meth)acrylate monomer, such as poly(methyl methacrylate / methacrylic acid).

[0068] The term "alkyl" refers to any monovalent radical of a straight or branched hydrocarbon chain containing from 1 to 12 carbon atoms. Examples of C1-C12 alkyl groups include C1-C4 alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, or t-butyl, C6-C8 alkyl groups such as n-hexyl, n-heptyl, or n-octyl, as well as n-pentyl, 2-ethylhexyl, 3,5,5-trimethylhexyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, or n-octadecyl.

[0069] Examples of C1-C12 alkyl (meth)acrylate monomers include, but are not limited to, methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate, and combinations of two or more thereof.

[0070] Examples of such commercially available copolymers that can be used with the gel medium of the present invention include, but are not limited to, poly(methyl methacrylate / methacrylic acid) from Sigma Aldrich or Polysciences.

[0071] The multifunctional polymer may be selected from copolymers prepared from (meth)acrylic acid monomers or C1-C4 substituted (meth)acrylic acid monomers and at least one ethylenically unsaturated C1-C12 alkene.

[0072] The term "alkene" refers to any unsaturated hydrocarbon straight or branched chain containing from 1 to 12 carbon atoms containing a carbon-carbon double bond.

[0073] Examples of ethylenically unsaturated C1-C12 alkenes include, but are not limited to, 1-octene, 1-undecene, 1-octadecene, 5-methyl-1-heptene, and combinations of two or more thereof.

[0074] The multifunctional polymer may be selected from copolymers prepared from (meth)acrylic acid monomers or C1-C4 substituted (meth)acrylic acid monomers and at least one aromatic monoalkenyl monomer, such as styrene.

[0075] The polyfunctional polymer may be selected from copolymers prepared from vinyl acetate monomer and at least one ethylenically unsaturated organic carboxyl monomer containing 3 to 9 carbon atoms and at least one carboxyl group, such as copolymers of vinyl acetate and fumaric acid, copolymers of vinyl acetate and crotonic acid, copolymers of vinyl acetate and maleic acid.

[0076] Examples of such ethylenically unsaturated organic carboxylic monomers include, but are not limited to, succinic acid or its substitutes, 3-butenoic acid; 6-heptenoic acid; 6-methyl 6-heptenoic acid; 2-methyl 6-heptenoic acid; 3-methyl 6-heptenoic acid; 3-ethyl 6-heptenoic acid; 5-methyl 6-heptenoic acid; 4-methyl 6-heptenoic acid; 6-octenoic acid; 2-propyl 6-heptenoic acid; and 2,4-dimethyl 6-heptenoic acid; and combinations of two or more thereof.

[0077] Preferably, the copolymer comprises 80% to 99.95% by weight of vinyl acetate monomer and 0.05% to 20% by weight of at least one ethylenically unsaturated organic carboxyl monomer containing from 3 to 9 carbon atoms and at least one carboxyl group.

[0078] More preferably, the copolymer comprises 90% to 99.95% by weight of vinyl acetate monomer and 0.05% to 10% by weight of at least one ethylenically unsaturated organic carboxyl monomer containing from 3 to 9 carbon atoms and at least one carboxyl group.

[0079] Examples of such commercially available copolymers that can be used in the gel medium of the present invention include, but are not limited to, Wacker's Vinnapas C grades, such as Vinnapas C501.

[0080] The polyfunctional polymer is a C1-C 12Copolymers prepared from alkyl vinyl ether monomers and at least one ethylenically unsaturated organic carboxyl monomer containing 3 to 9 carbon atoms and at least one carboxyl group, such as poly(methyl vinyl ether-alt-maleic acid).

[0081] Examples of such ethylenically unsaturated organic carboxylic monomers include, but are not limited to, succinic acid or its substitutes, 3-butenoic acid; 6-heptenoic acid; 6-methyl 6-heptenoic acid; 2-methyl 6-heptenoic acid; 3-methyl 6-heptenoic acid; 3-ethyl 6-heptenoic acid; 5-methyl 6-heptenoic acid; 4-methyl 6-heptenoic acid; 6-octenoic acid; 2-propyl 6-heptenoic acid; and 2,4-dimethyl 6-heptenoic acid; and combinations of two or more thereof.

[0082] Examples of C1-C12 alkyl vinyl ether monomers include, but are not limited to, methyl vinyl ether, ethyl methyl vinyl ether, propyl methyl vinyl ether, isopropyl methyl vinyl ether, butyl methyl vinyl ether, isobutyl methyl vinyl ether, tert-butyl methyl vinyl ether, and 2-ethylhexyl methyl vinyl ether, and combinations of two or more thereof.

[0083] The multifunctional polymer may be selected from carboxydifunctional PEG or PPG derivatives, such as PEG-dipropionic acid, PEG-di-succinic acid, PEG-di-glutaric acid, PEG bis[2-(succinylamino)ethyl].

[0084] Examples of carboxy bifunctional PEG or PPG derivatives can have the general structure: X-PEG-Y or X-PPG-Y, where X and Y can be the same or different and can be selected from residues comprising at least one carboxyl group and an additional group selected from C1-C5 alkylene, C1-C5 amide, or C1-C5 ester, such as [ka] It is.

[0085] The term "PEG" as used herein corresponds to polyethylene glycol.

[0086] The term "PPG" as used herein corresponds to polypropylene glycol.

[0087] Examples of commercially available carboxy difunctional PEG or PPG derivatives that can be used with the gel media of the present invention include, but are not limited to, AA-PEG-AA (carboxymethyl-PEG-carboxymethyl), GAA-PEG-GAA (having a C3 amide bond between the PEG and the carboxy COOH group), SA-PEG-SA (succinic acid-PEG-succinic acid) (), SAA-PEG-SAA (having a C2 amide bond between the PEG and the carboxy COOH group), PEG Diacid by Polyure, (O,O'-bis(2-carboxyethyl)dodecaethylene glycol (or PEG-dipropionic acid) by Jenkem Technology, and PEO Bis Carboxylic Acid by Specific Polymers.

[0088] The multifunctional polymers include 4-arm PEG-carboxylic acid with a pentaerythritol core, 4-arm PEG-dicarboxylic acid-diol with a pentaerythritol core, carboxylic acid terminated PEG dendrimers of the formula: [ka] (In the formula, n is an integer of 200 to 20,000.) The compound can be selected from multi-arm PEG carboxylic acid-terminated derivatives such as:

[0089] Another multi-arm PEG carboxylic acid terminated derivative can have the following chemical structure: [ka] (wherein n is an integer of 20 to 20,000).

[0090] An example of a multi-arm PEG carboxylic acid terminated derivative can have the following general structure: C-[CH2-O-(PEG)-R 3 -COOH]4(wherein, R 3 is selected from C1-C5 alkylene, C1-C5 amide, or C1-C5 ester, e.g., a 4-arm PEG-carboxylic acid having a pentaerythritol core; · x [OH-R 3 '-(PEG)-CH2]-C-[CH2-O-(PEG)-R 3 '-COOH] 4-x (wherein x may be 1 or 2; R 3 ' is selected from C1-C5 alkylene, e.g., 4-arm PEG-dicarboxylic acid, diols with a pentaerythritol core). Examples of commercially available multi-arm PEG carboxylic acid terminated derivatives that can be used with the gel media of the present invention include, but are not limited to, 4-arm-PEG-AA, 4-arm-PEG-GA, 4-arm-PEG-GAA, 4-arm-PEG-SA, 4-arm-PEG-SAA available from NanoSoft Polymers, 4-arm-PEG, 2-arm Hydroxyl, 2-arm-Acetic Acid from Jenkem Technology.

[0091] The multifunctional polymer may be selected from poly(lactide-co-glycolide) (PLGA) carboxylic acid terminated derivatives, such as poly(D,L-lactide-co-glycolide) end-capped with acid groups (PLGA diacid).

[0092] The term "endcapped" is used herein to refer to an end or terminus of a polymer having an endcap carboxyl moiety.

[0093] Examples of such commercially available derivatives that can be used in the gel medium of the present invention include, but are not limited to, PLGA DIACID available from NanoSoft Polymers.

[0094] The multifunctional polymer may also be selected from multi-arm PLGA carboxylic acid end derivatives, such as a 4-arm PLGA carboxylic acid with a pentaerythritol core.

[0095] Examples of carboxy bifunctional PEG or PPG derivatives have the following general structure: [ka] where n is an integer from 2 to 20000, and x and y are the same or different integers ranging from 1 to 150; R is selected from C1 to C5 alkylene.

[0096] An example of a multi-arm PLGA carboxylic acid-terminated derivative has the general structure: C-[CH2-O-(PLGA)-R 6 —COOH]4, where R 6 is selected from a C1 to C5 alkylene, a C1 to C5 amide, or a C1 to C5 ester.

[0097] Examples of commercially available multi-arm PLGA carboxylic acid-terminated derivatives that can be used with the gel media of the present invention include, but are not limited to, 4-arm PLGA-COOH available from NanoSoft Polymers.

[0098] The multifunctional polymer may be selected from poly(ε-caprolactone)-PEG (PCL-PEG) carboxylic acid terminated derivatives.

[0099] The multifunctional polymer may be selected from PLGA-PEG carboxylic acid terminated derivatives.

[0100] The multifunctional polymer may be selected from PLA-PEG carboxylic acid terminated derivatives.

[0101] The multifunctional polymer may be selected from PCL-PEG carboxylic acid terminated derivatives.

[0102] The multifunctional polymer is [ka] The polyester dendrimers may be selected from polyester dendrimers having 2,2-bis(hydroxymethyl)propanoic acid (bis-MPA), trimethylolpropane, or pentaerythritol as the core, such as:

[0103] Examples of commercially available dendrimers that can be used in the gel medium of the present invention include, but are not limited to, Bis-MPA carboxyl dendrimer, generation 1, TMP core, or Bis-MPA carboxyl dendrimer, generation 2, TMP core from Polymer Factory.

[0104] The multifunctional polymer can be selected from a polyurethane matrix containing at least two carboxyl sites, the polyurethane matrix being obtained from the reaction of a polyol with an alkylene oxide isocyanate compound.

[0105] Thus, either or both of the polyol, alkylene oxide, and isocyanate compounds further contain at least one carboxyl moiety.

[0106] The polyurethane matrix can be prepared according to art-recognized methods. Polyurethanes can be prepared from the reaction of a polyol, such as a diol, with a polyisocyanate, such as a diisocyanate.

[0107] Examples of the alkylene oxide in the alkylene oxide isocyanate compound include ethylene oxide, propylene oxide, butylene oxide, and styrene oxide.

[0108] An example of a polyol that can be used to prepare the polyurethane matrix can be a four-arm PEG, each endcapped with both hydroxyl and carboxyl sites.

[0109] The multifunctional polymer may be selected from mixtures or reaction products of the multifunctional polymers described above.

[0110] Copolymers of acrylates and methacrylates or styrene acrylates or styrene methacrylates, examples of polymers or copolymers made from ionic liquids can also be used. Such ionic liquid monomers developed by SOLVIONIC can be easily converted into polymers by thermal means or UV polymerization. Examples include, but are not limited to, 1,4-butanediyl-3,3'-bis-1-vinylimidazolium di-bis(trifluoromethanesulfonyl)imide or 3-ethyl-1-vinylimidazolium bis(fluorosulfonyl)imide.

[0111] Crosslinker: A crosslinking agent is used in the preparation of the gel of the present invention.

[0112] If a crosslinker is not used, a layer is obtained that has a sufficient amount of polymer to achieve a solid state, but does not have good mechanical properties, and therefore, after bending the sample, flow of the formulation from the pinch zone can be observed over time.

[0113] The crosslinking agent useful in the present invention may be a polycarbodiimide.

[0114] Polycarbodiimides react selectively with the carboxylic acid (-COOH) groups of polyfunctional (or multifunctional) polymers. This type of crosslinking reaction results in the formation of a classical 3D polymer-crosslinker network.

[0115] Polycarbodiimides useful in the present invention contain at least two carbodiimide groups, such as at least three carbodiimide groups, or at least four carbodiimide groups.

[0116] Here we show a schematic of the synthesis route to the resulting crosslinked polymer containing the polycarbodiimide. After the formation of an unstable intermediate, the stable N-acylurea shown here is formed. Because polycarbodiimides contain multiple -N=C=N- groups, one polycarbodiimide molecule can react with carboxylic acid residues on different polymer chains, linking them together to form a three-dimensional network. The reaction of carboxylic acids with carbodiimides can be very fast under ambient or mild thermal cure conditions (Derksen, Andre. (2017). Polycarbodiimides as classification-free and easy to use crosslinkers for water-based coatings. Pci Journal). [ka]

[0117] In some embodiments of the invention, the crosslinking agent for preparing the crosslinked polymer of the gel medium is a polycarbodiimide obtainable by a reaction comprising the condensation of multifunctional isocyanates, each multifunctional isocyanate being selected from the group consisting of aliphatic multifunctional isocyanates, cycloaliphatic multifunctional isocyanates, heteroaliphatic multifunctional isocyanates, aryl multifunctional isocyanates, arylaliphatic multifunctional isocyanates, and combinations of two or more thereof.

[0118] As used herein, the term "polyfunctional isocyanate" means a material having at least two isocyanate groups. The polyfunctional isocyanates used to form the polycarbodiimides can have 2 to 10 isocyanate groups, or 2 to 8 isocyanate groups, or 2 to 6 isocyanate groups, or 2 to 5 isocyanate groups, or 2 or 3 isocyanate groups, inclusive of the recited values ​​in each case.

[0119] Preferably, the resulting polycarbodiimide does not contain free isocyanate functional groups.

[0120] In another embodiment, the polycarbodiimide is selected from oligomeric materials that include carbodiimide functional groups and hydrophilic segment groups that are not reactive toward the carbodiimide functional groups.

[0121] The oligomeric materials containing carbodiimide functional groups are further substituted with at least alkylalkoxysilane or alkoxysilane groups, preferably further substituted trimethoxysilane or triethoxysilane.

[0122] Examples of commercially available polycarbodiimide materials that can be used in the gel media of the present invention include, but are not limited to, PICASSIAN® XL-701, XL-702, XL-725, XL-721, and XL-732, EX-5558 from Stahl Holland; STABAXOL P, STABAXOL P100, and STABAXOL P200 polycarbodiimides available from Rhein Chemie Staboxol; carbodiimide crosslinkers XL-1 V and CX-300® from DSM Coating Resins; carbodiimide crosslinkers CARBODILITE® V-02, V-04, E-02, and SV-02 from GSI Exim America; CARBODILITE V-02B, CARBODILITE V-04K, CARBODILITE V-05, CARBODILITE E02, CARBODILITE E04, CARBODILITE V-02 ... Examples of polycarbodiimides include polycarbodiimides commercially available from NISSHINBO INDUSTRIES, NK ASSIST CIR polycarbodiimides commercially available from Nicca Chemical Co., Ltd, ZOLDINE from ANGUS, and the carbodiimide crosslinker UCARLINK® XL-29SE from Union Carbide Corporation. Preferably, the polycarbodiimide is used in its pure form or in a composition further comprising an organic solvent.

[0123] Importantly, the crosslinker is not harmful, irritating or toxic, as confirmed by toxicological studies.

[0124] Alternatively, the cross-linking agent for preparing the cross-linked polymer of the gel medium according to the present invention is a non-toxic polyaziridine.

[0125] US Pat. No. 9,500,888 generally mentions the use of aziridines as curable functional groups in gel electrolytes.

[0126] Examples of commercially available non-toxic polyaziridine materials that can be used in the gel medium of the present invention include, but are not limited to, NeoAdd™ PAX521 and NeoAdd™ PAX523 by DSM.

[0127] A schematic of the synthesis route to the resulting crosslinked polymers containing said polyaziridines is presented here: The reaction involves a ring-opening step of an electrophilic aziridine with an acid as the nucleophile. [ka]

[0128] Another crosslinker combines an aziridine functional group with a carbodiimide functional group in one molecule, as described in EP 0 507 407 B1.

[0129] The gel according to the invention advantageously comprises an equivalent ratio of carbodiimide equivalents of the polycarbodiimide to carboxylic acid equivalents of said multifunctional polymer of between 0.1:1 and 10:1, preferably between 0.2:1 and 5:1.

[0130] pigment The gel medium may further comprise at least one dye which is a passive (or permanent) dye, an active dye, or a mixture thereof, preferably selected from photochromic compounds (dichroic or non-dichroic), dichroic compounds, electrochromic compounds, and fixed color dyes, and mixtures thereof, more preferably at least one photochromic compound or at least one electrochromic compound, preferably at least two electrochromic compounds.

[0131] Thus, the gel medium may comprise at least one dye or a mixture of dyes, said at least one dye being, for example, selected from: Electrochromic compounds (electrochromic pigments) or mixtures of electrochromic pigments; Photochromic dyes (dichroic or non-dichroic) or mixtures of photochromic dyes; · dichroic compounds or mixtures of dichroic compounds; · a fixed color dye as described herein; · and any mixture of the above.

[0132] When a dichroic compound or a mixture of dichroic compounds is used, the solvent is preferably a mesogenic compound (liquid crystal phase), which is understood herein to be a phase in which liquid crystal mesogens are ordered, as opposed to an isotropic phase in which the liquid crystal is in an isotropic state, and which is typically one of a nematic phase and a smectic phase.

[0133] Electrochromic Dyes When the gel medium of the present invention is an electrochromic gel medium, said gel may further comprise a redox chemical mixture interspersed in the crosslinked polymer in solution in a non-aqueous solvent, said mixture being composed of at least one reducing compound, preferably at least one electrochromic reducing compound and at least one electrochromic oxidizing compound, which is in an activated state in the presence of an applied voltage and fades to an inactivated state in the absence of an applied voltage.

[0134] The at least one reducing compound of the solution of the present invention is not particularly limited. The at least one reducing compound does not have to be an electrochromic compound. However, it should be selected from among compounds that have at least the following properties: low absorption of visible light in the bleached state (when the reducing compound is also an electrochromic compound), good stability, especially good stability to oxygen, and good solubility in conventional electrochromic solvents such as propylene carbonate.

[0135] The electrochromic reducing compound may be selected from ethylferrocene, t-butylferrocene, phenoxazines and their derivatives, such as N-benzylphenoxazine, phenazines and their derivatives, such as 5,10-dihydrophenazine, N,N,N',N'-tetramethyl-p-phenylenediamine, phenothiazines and their derivatives, such as 10-methylphenothiazine and isopropylphenothiazine; thioanthrene; thiophene, and tetrathiafulvalene.

[0136] The at least one electrochromic oxidizing compound is not particularly limited. The at least one electrochromic oxidizing compound is selected from monoviologens or bisviologens (i.e., 4,4'-bipyridinium salts or bis[4,4'-bipyridinium] salts), such as alkyl viologens, aryl viologens, aryl alkyl viologens, alkyl aryl viologens, anthraquinones, benzazoles, imidazo[1,2-α]pyridines, 2,1,3-benzothiadiazoles, imidazoles, benzoselenadiazoles, benzoselenazoles, and derivatives thereof.

[0137] Non-limiting examples of such viologen compounds or viologen derivatives, more particularly substituted dialkyl, diaryl 4,4'-bipyridinium salts, substituted dialkyl, diaryl bis[4,4'-bipyridinium] salts, and mixtures thereof, are described in EP 2848667A1, EP 2848668A1, EP 2848669A1, EP 2848670A1, EP 3115433A1, and EP 3345981A1, the teachings of which are incorporated herein. Preferred examples are now mentioned.

[0138] In a preferred embodiment, the redox chemical mixture comprises at least one reducing compound, preferably one reducing compound (such as 10-methylphenothiazine), and at least one electrochromic oxidizing compound, preferably at least two electrochromic oxidizing compounds, for example two or three electrochromic oxidizing compounds, preferably each electrochromic oxidizing compound independently selected from a substituted dialkyl 4,4'-bipyridinium salt, a substituted diaryl 4,4'-bipyridinium salt, a substituted dialkyl bis[4,4'-bipyridinium] salt, or a substituted diaryl bis[4,4'-bipyridinium] salt, more preferably the at least two electrochromic oxidizing compounds are at least a substituted diaryl 4,4'-bipyridinium and at least a substituted diaryl bis[4,4'-bipyridinium].

[0139] Preferably, at least one oxidizing compound is selected, or at least two electrochromic oxidizing compounds are independently selected, from the following series of compounds:

[0140] [Table 1]

[0141] [Table 2]

[0142] [Table 3]

[0143] [Table 4]

[0144] [Table 5]

[0145] [Table 6]

[0146] [Table 7]

[0147] [Table 8]

[0148] [Table 9]

[0149] [Table 10]

[0150] [Table 11]

[0151] [Table 12]

[0152] More preferably, at least one electrochromic oxidizing compound is selected, or at least two electrochromic oxidizing compounds are independently selected, from the following series of compounds:

[0153] [Table 13]

[0154] [Table 14]

[0155] [Table 15]

[0156] [Table 16]

[0157] [Table 17]

[0158] [Table 18]

[0159] [Table 19]

[0160] [Table 20]

[0161] [Table 21]

[0162] In one particularly preferred embodiment, the redox chemical mixture comprises: One reducing compound and at least one electrochromic oxidizing compound, preferably at least two electrochromic oxidizing compounds, It is composed of The at least one electrochromic oxidizing compound is either a compound of formula Ia or a compound of formula IIa, and the at least two electrochromic oxidizing compounds are selected from the group consisting of compounds of formula Ia and compounds of formula IIa: [ka] (In the formula, R 1 and R 2 are, independently: [ka] Selected from X - is a counterion selected from halide, tetrafluoroborate, tetraphenylborate, hexafluorophosphate, nitrate, methanesulfonate, trifluoromethanesulfonate, toluenesulfonate, hexachloroantimonate, bis(trifluoromethanesulfonyl)imide, perchlorate, acetate, and sulfate. [ka] (wherein Z is -CH2-, -(CH2)2-, -(CH2)3-, -(CH2)4-, -(CH2)5-, -CH2-CH(CH3)-CH2-, -CH2-CH(CH2phenyl)-CH2-, -(CH2)2-CH(CH3)-CH2-, -(CH2)3-CH(CH3)-CH2-, -(CH2)2-, and CH(CH3)-(CH2)2-; R 3 and R 4 is selected from alkyl and optionally substituted phenyl groups, preferably [ka] is a substituted phenyl group independently selected from:

[0163] According to a preferred embodiment, the redox chemical mixture is selected from a mixture consisting of 10-methylphenothiazine and at least two electrochromic oxidizing compounds selected from the group consisting of compounds of formulae I-10 and II-10, and I-38 and II-10. [ka]

[0164] Photochromic Dyes When the gel medium of the present invention is a photochromic gel medium, said gel further comprises at least one photochromic dye (or photochromic compound).

[0165] In principle, any stable photochromic dye can be used that is soluble in the non-aqueous solvent or solvents used in the gel medium described above. It is preferable to choose a photochromic dye that shows a large difference in transmittance between the activated and deactivated states. Advantageously, the photochromic dye is colorless in the deactivated state.

[0166] As used herein, the term "dichroic" and similar terms such as "dichroic" refer to the ability to absorb one of two orthogonal plane-polarized components of radiation (including transmitted and / or reflected radiation) more strongly than the other orthogonal plane-polarized component.

[0167] The photochromic dye may be selected from the group consisting of naphthopyrans, benzopyrans, phenanthropyrans, indenonaphthopyrans, spiro(indoline)naphthoxazines, spiro(indoline)pyridobenzoxazines, spiro(benzindoline)pyridobenzoxazines, spiro(benzindoline)naphthoxazines, spiro(indoline)-benzoxazines, fulgides, fulgimides, diarylethenes, and mixtures of such photochromic compounds.

[0168] The photochromic dye is preferably selected from spirooxazines, spiroindoline[2,3']benzoxazines, chromenes, homoazaadamantanes, azobenzenes, spirofluorene-(2H)-benzopyrans, naphtho[2,1-b]pyrans, and naphtho[1,2-b]pyrans, and mixtures of such photochromic compounds.

[0169] Further examples of other photochromic compounds that can be used in the curable photochromic compositions of the present invention include, but are not limited to, those disclosed in U.S. Pat. No. 9,028,728 B2, column 34, line 20 to column 35, line 13, the disclosures of which are specifically incorporated by reference herein.

[0170] dichroic compound The gel medium of the present invention may include dichroic dyes that do not exhibit electrochromic or photochromic properties.

[0171] Examples of dichroic dyes include, but are not limited to, azomethines, indigoids, thioindigoids, merocyanines, indanes, quinophthalone dyes, perylenes, phthaloperines, triphenodioxazines, indoloquinoxalines, imidazotriazines, tetrazines, azo and (poly)azo dyes, benzoquinones, naphthaquinones, anthraquinones and (poly)anthraquinones, anthrapyrimidinones, iodine, iodates, or combinations of two or more thereof.

[0172] fixed color dye The gel medium of the present invention may also include a dye selected from passive dyes, such as fixed color dyes, either alone or in addition to photochromic or electrochromic dyes.

[0173] The term "fixed color pigment" as used herein is equivalent to "fixed colorant," "static colorant," "fixed pigment," and "static dye," "permanent dye." Such terms refer to a pigment that is a non-photochromic or non-electrochromic material that does not respond physically or chemically to electromagnetic radiation with respect to its visually observed color. As used herein, the term "fixed color pigment" and related terms are not included in and are distinguishable from the terms photochromic compound, electrochromic mixture, and related terms.

[0174] One or more fixed color pigments can be present in the gel medium such that a final article is obtained that has at least a base (or first) color characteristic of the fixed color pigment when the photochromic or electrochromic compound is not activated, and optionally a second color characteristic of the combination of the fixed color pigment and the photochromic or electrochromic compound when activated, such as by exposure to actinic radiation or leakage current.

[0175] The terms "active" or "activated," when used in conjunction with a particular state or condition of a gel composition, refer to an activated state or condition of the gel composition in which a dye, such as a photochromic or electrochromic dye, has been exposed to actinic radiation or leakage current. These terms are in contrast to the terms "inactive" or "deactivated," which refer to an inactive state or condition of the gel composition in which a dye, such as a photochromic or electrochromic dye, has not been exposed to actinic radiation or leakage current.

[0176] The optional fixed color dyes include at least one of azo dyes, anthraquinone dyes, xanthene dyes, azido dyes, iodine, iodide salts, polyazo dyes, stilbene dyes, pyrazolone dyes, triphenylmethane dyes, quinoline dyes, oxazine dyes, thiazine dyes, and polyene dyes.

[0177] The fixed color pigment may be present in the gel medium in an amount of 0.001 to 15 weight percent, or 0.01 to 10 weight percent, or 0.1 to 2.5 weight percent based on the weight of total solids.

[0178] solvent: As mentioned above, the gels of the present invention are organogel comprising a non-aqueous solvent, preferably said solvent being present in said gel medium in an amount of at least 30% by weight relative to the total weight of the gel, more preferably at least 50% by weight relative to the total weight of the gel.

[0179] The term "non-aqueous" solvent as used herein means that no water is specifically added to the formulations described herein. The term "non-aqueous" does not exclude the presence of trace amounts of water present in the formulation, such as less than 10% by weight based on the total weight of the gel medium, preferably less than 1% by weight based on the gel medium, and more preferably less than 0.5% by weight based on the gel medium.

[0180] The gel medium may contain trace amounts of water, such as less than 10% by weight based on the total weight of the gel medium, preferably less than 1% by weight based on the total weight of the gel medium, and more preferably less than 0.5% by weight based on the total weight of the gel medium.

[0181] Preferably, the gel medium is free of water. Suitable solvents are those that are chemically inert towards the other compounds of the gel medium according to the invention and towards the materials forming the device that receives said gel medium.

[0182] Additionally, suitable solvents are those in which the other compounds of the gel medium, except for the crosslinked polymer, are soluble. In particular, non-aqueous solvents useful in the present invention are liquids that solubilize the dyes, particularly electrochromic or photochromic dyes, but do not solubilize the crosslinked polymer.

[0183] The non-aqueous solvent of the gel medium of the present invention may be selected from an organic solvent or solvent mixture and / or at least one ionic liquid.

[0184] The non-aqueous solvent of the gel medium of the present invention, particularly when an electrochromic dye is present, may be selected from the group consisting of ethylene carbonate, propylene carbonate, butylene carbonate, 1,2-dimethylethylene carbonate, ethyl butyl carbonate, methyl butyl carbonate, dibutyl carbonate, diethyl carbonate, dimethyl carbonate, trifluoromethylethylene carbonate, vinylene carbonate, di-n-propyl carbonate, diisopropyl carbonate, methyl ethyl carbonate, ethyl propyl carbonate, ethyl isopropyl carbonate, and the like. Pyrcarbonate, methylpropyl carbonate, gamma-butyrolactone, gamma-valerolactone, acetonitrile, propionitrile, benzonitrile, glutaronitrile, methylglutaronitrile, dimethylformamide, N-methylpyrrolidone, sulfolane, 3-methylsulfolane, methylpropionate, ethylene glycol, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, dimethyl sulfoxide, sulfolane, 4-methyl-1,3-Butyrolactone, γ-Butyrolactone, Methyl formate, Ethyl formate, Methyl acetate, Ethyl acetate, Methyl propionate, Ethyl propionate, Methyl butyrate, Ethyl butyrate, Propylene glycol diacetate, Propylene glycol methyl ether diacetate, Propylene glycol, Propane sultone, Ethylene sulfite, Dimethoxyethane, Diethoxyethane, Tetrahydrofuran, 2-Methyltetrahydrofuran, Methyl ether acetate, Methyl ethyl ketone, Acetone, Ethanol, Tetrahydrofurfur alcohol, N-methylpyrrolidone, 2-methoxyethyl ether, xylene, cyclohexane, 3-methylcyclohexanone, ethyl acetate, ethyl phenylacetate, ethyl methoxyphenylacetate, propylene carbonate, diphenylmethane, diphenylpropane, tetrahydrofuran, methanol, methyl propionate, high-boiling or low-melting phthalate derivatives (such phthalate derivatives are bis(2-ethylhexyl phthalate) (DEHP), diisononyl phthalate (DINP), di-n-octyl phthalate, etc.) diisodecyl phthalate (DNOP), diisodecyl phthalate (DIDP), dipropylheptyl phthalate (DPHP), di-2-ethylhexyl terephthalate (DOTP or DEHT), high-boiling or low-melting polyethylene glycol dibenzoates or polypropylene glycol dibenzoates, halomethanes, dichloromethane; cyclic ethers, tetrahydrofuran, and dioxane; alkyl acetates, ethyl acetate; alkyl lactates, ethyl lactate; alkyl nitriles (or alkyl cyanides), acetonitrile (or methyl cyanide); dialkyl The solvent may be selected from alkylformamide, dimethylformamide; dialkylsulfoxides, dimethylsulfoxide; ketones, acetone, and methyl ethyl ketone; N-substituted cyclic amides (lactams), N-methyl-2-pyrrolidone, and N-butyl-2-pyrrolidone; aromatics, benzene, toluene, xylene, anisole, butyl benzoate, dialkylbenzenes, trialkylbenzenes, and mixtures thereof, and preferably the solvent is propylene carbonate, especially when an electrochromic dye is present.

[0185] The solvent may be a mixture of acetate compounds such as propylene glycol acetate or propylene glycol methyl ether acetate. Such a solvent or solvent mixture is particularly useful for diluting the carbodiimide.

[0186] Examples of suitable solvents for the gel in the presence of photochromic dyes are halomethanes such as dichloromethane; cyclic ethers such as tetrahydrofuran and dioxane; high-boiling or low-melting phthalic acid derivatives (such phthalate ester derivatives are bis(2-ethylhexyl phthalate) (DEHP), diisononyl phthalate (DINP), di-n-octyl phthalate (DNOP), diisodecyl phthalate (DIDP), dipropylheptyl phthalate (DPHP), di-2-ethylhexyl terephthalate (DOTP or DEHT)); high-boiling or low-melting polyethylene glycol dibenzoates; ethyl acetate, etc. dialkyl sulfoxides such as dimethyl sulfoxide; ketones such as acetone and methyl ethyl ketone; N-substituted cyclic amides (lactams) such as N-methyl-2-pyrrolidone and N-butyl-2-pyrrolidone; aromatic compounds such as toluene, xylene, anisole, butyl benzoate, dialkylbenzenes, trialkylbenzenes, AROMATIC 100 Fluid, a commercially available mixture of C9-C10 dialkyl- and trialkyl-benzenes, and AROMATIC 150 Fluid, a commercially available mixture of C9-C11 alkylbenzenes.

[0187] Preferably, the solvent may be a mixture of multiple phthalate-based and / or acetate-based compounds.

[0188] When a dichroic compound or a mixture of dichroic compounds is used, the solvent is preferably a liquid crystal solvent (nematic or cholesteric).The organic solvent may further be selected from the group consisting of benzene, toluene, methyl ethyl ketone, acetone, ethanol, tetrahydrofurfuryl alcohol, N-methylpyrrolidone, 2-methoxyethyl ether, xylene, cyclohexane, 3-methylcyclohexanone, ethyl acetate, ethyl phenylacetate, ethyl methoxyphenylacetate, propylene carbonate, diphenylmethane, diphenylpropane, tetrahydrofuran, methanol, methyl propionate, ethylene glycol, and mixtures thereof. Ionic liquids may also be used as solvents in the present invention. Such ionic liquids are, for example, those described in WO 2009 / 115721, preferably 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, 1-butyl-2,3-dimethylimidazolium bis(trifluoromethylsulfonyl)amide, N-butyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, 1-methyl-1-propylpiperidinium bis(trifluoromethylsulfonyl)amide, 1-octyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, 2,3-dimethyl-1-propylimidazolium bis(trifluoromethylsulfonyl)amide, N-propyl-N-methylpyrrolidinium bis(trifluoromethylsulfonyl)amide, N,N,N-trib ethyl-N-methylammonium bis(trifluoromethylsulfonyl)amide, N,N,N-trimethyl-N-butylammonium bis(trifluoromethylsulfonyl)amide, N,N,N-trimethyl-N-hexylammonium bis(trifluoromethylsulfonyl)amide, N,N,N-trimethyl-N-propylammonium bis(trifluoromethylsulfonyl)amide, 1-phenylethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, (phenylethyl)-dimethylbenzylammonium bis(trifluoromethylsulfonyl)amide, ethyldimethylbenzylammonium bis(trifluoromethylsulfonyl)amide, 1-butyl-3-methylimidazolium tetrafluoroborate, 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, N,N,N-trimethyl-N-butylammonium tetrafluoroborate, N,N,N-trimethyl-N-hexylammonium tetrafluoroborate, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium acetate, bromide, chloride, dicyanamide, hexafluorophosphate, hydrogen sulfate, methanesulfonate, tetrachloroaluminate, and trifluoromethanesulfonate, 1-butyl-1-methylpyrrolidinium acetate, chloride, bromide, dicyanamide, hexafluorophosphate, hydrogen sulfate, and trifluoromethanesulfonate , 1-(2-hydroxyethyl)-3-methylimidazolium bromide, chloride, dicyanamide, and hexafluorophosphate, 1-ethyl-3-methylimidazolium bromide, chloride, hexafluorophosphate, tetrachloroaluminate, and trifluoromethanesulfonate, 1-hexyl-3-methylimidazolium hexafluorophosphate, 1-hexyl-3-methylimidazolium trifluoromethanesulfonate, or hydromethylimidazolium hydrochloride or methanesulfonate.

[0189] Said ionic liquids can therefore be incorporated into the gel medium according to the invention in the form of "ionic solvents", a term which has a broader meaning than "ionic liquid" and which encompasses any liquid having a melting point below 20° C. and comprising in total at least 50% by weight, preferably at least 70% by weight, of one or more "ionic liquids" as defined above (organic salts with a melting point below 100° C.).

[0190] Examples of suitable solvents for the gel according to the invention that is adapted to be incorporated into a battery are ethylene carbonate, propylene carbonate, butylene carbonate, 1,2-dimethylethylene carbonate, ethyl butyl carbonate, methyl butyl carbonate, dibutyl carbonate, diethyl carbonate, dimethyl carbonate, trifluoromethylethylene carbonate, di-n-propyl carbonate, diisopropyl carbonate, methyl ethyl carbonate, ethyl propyl carbonate, ethyl isopropyl carbonate, methyl propyl carbonate, The alkyl ether compound may be, for example, dimethyl ether, dimethoxyethane, diethoxyethane, tetrahydrofuran, 2-methyltetrahydrofuran, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, dimethyl sulfoxide, sulfolane, 4-methyl-1,3-butyrolactone, γ-butyrolactone, methyl formate, ethyl formate, methyl acetate, ethyl acetate, methyl propionate, ethyl propionate, methyl butyrate, ethyl butyrate, vinylene carbonate, propane sultone, or ethylene sulfite.

[0191] Electrolytes: The composition of the present invention may further comprise an inert conductive electrolyte. The inert conductive electrolyte must be compatible with the other components of the composition. In particular, the inert conductive electrolyte should not react with the electrochromic compound.

[0192] Examples of inert conductive electrolytes include, but are not limited to, alkali metal salts, lithium, sodium, or tetraalkylammonium salts, aluminum chloride and aluminum boride, persulfates, and bis(fluorosulfonyl)imides. The inert conductive electrolytes are preferably selected from sodium, lithium, and tetraalkylammonium ions in combination with inert anions preferably selected from chlorides, tetrafluoroborates, hexafluoroborates, and perchlorates.

[0193] Other examples of inert anions include, but are not limited to, tetraphenylborate, cyano-triphenylborate, tetramethoxyborate, tetrapropoxyborate, tetraphenoxyborate, perchlorate, chloride, nitrate, sulfate, phosphate, methanesulfonate, ethanesulfonate, tetradecanesulfonate, pentadecanesulfonate, trifluoromethanesulfonate, perfluorobutanesulfonate, perfluoroctanesulfonate, benzenesulfonate, chlorobenzenesulfonate, toluenesulfonate, butylbenzenesulfonate, tert-butylbenzenesulfonate, dodecylbenzenesulfonate, trifluoromethylbenzenesulfonate, hexafluorophosphate, hexafluoroarsenate, or hexafluorosilicate. The most preferred inert conductive electrolyte is tetra-n-butylammonium tetrafluoroborate.

[0194] When present in a gel medium, the concentration of the inert, electrically conducting electrolyte is typically 0.005-2M, preferably 0.01-1M, and more preferably 0.05-0.5M.

[0195] Suitable additional additives for electrochromic media, where protection against UV light (<400 nm) is optionally desired, are for example UV absorbers. Examples are 2,4-dihydroxybenzophenone (UVINUL® 3000, BASF), 2-hydroxy-4-n-octyloxybenzophenone (SANDUVOR® 3035, Clariant), 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (Tinuvin® 571, Ciba), 2,2′-dihydroxy-4-methoxy-benzophenone (Cyasorb24™, American Cyanamid). Company), ethyl 2-cyano-3,3-diphenylacrylate (UVINUL® 3035, BASF), 2-ethylhexyl 2-cyano-3,3-diphenyl-acrylate (UVINUL® 3039, BASF), 2-ethylhexyl p-methoxycinnamate (UVINUL® 3088, BASF), 2-hydroxy-4-methoxy-benzophenone (CHIMASSORB® 90, Ciba), dimethyl 4-methoxybenzylidenemalonate (SANDUVOR® PR-25, Clariant).

[0196] The cross-linking reaction between the multifunctional polymer and the cross-linking agent resulting in the self-supporting gel medium of the present invention occurs in the "reservoir" zone of the active element, particularly an electrically controllable or electrochromic device.

[0197] This gel medium is particularly satisfactory for potentially large devices (such as glazing) that are used in a vertical orientation and where the medium moves within the reservoir under its own weight, and therefore there is a risk of openings in the glazing due to hydrostatic pressure causing the glazing to "blister" if the two substrates are not sufficiently mechanically reinforced with a perimeter seal.

[0198] This gel medium is also particularly satisfactory for flexible and therefore deformable devices such as goggles, which can be used for activities such as skiing, or cycling, or motorcycling.

[0199] The gel medium according to the invention is advantageously 10 -5 It has a conductivity of better than 1.0 S / cm.

[0200] Furthermore, the gel preferably comprises Lack of color, Transparency, especially for visible light, Thermal and photochemical stability, Chemical inertia with respect to the optional pigments and with respect to the materials forming the walls of the active elements, in particular with respect to electrically controllable or electrochromic devices; Shows.

[0201] device According to another aspect, the present invention relates to a device comprising a gel medium as defined in the first aspect, said gel medium comprising: (a) external to the device; said at least one non-aqueous solvent; - said at least one optional dye, preferably selected from photochromic dyes, electrochromic dyes, dichroic dyes and fixed color dyes, more preferably selected from photochromic dyes and electrochromic dyes; - said multifunctional polymer comprising at least two carboxyl moieties capable of undergoing a crosslinking reaction, said multifunctional polymer having a molecular weight of 2,000 g / mol to 3,000,000 g / mol, preferably 10,000 to 1,000,000 g / mol, more preferably 25,000 g / mol to 400,000 g / mol; - said crosslinking agent being chosen from polycarbodiimides or non-toxic polyaziridines; forming a liquid composition by mixing; (b) placing the liquid composition of step (a) into the device and polymerizing the multifunctional polymer and the polycarbodiimide or polyaziridine, thereby forming a crosslinked polymer and forming a gel medium in which the compound and solvent are retained in a matrix containing the crosslinked polymer; is formed by.

[0202] The mixing step may be advantageously followed by a degassing step to remove oxygen and water from the liquid composition.

[0203] All the features previously described in relation to the gel medium of the present invention also apply to the device.

[0204] Preferably, said polyfunctional polymer has an acid value of 1 to 50 mg KOH / g, preferably 3 to 40 mg KOH / g, preferably 4 to 15 mg KOH / g.

[0205] The polyaziridine is advantageously in the form of a non-aqueous composition comprising between 40 and 100% of solid polyaziridine material relative to the total weight of said composition.

[0206] A suitable non-toxic polyaziridine is NeoAdd™ PAX-521 from DSM, supplied as an 80% solution in ethyl acetate. Another suitable polyaziridine is NeoAdd™ PAX-523 from DSM, supplied as an 80% solution in methoxypropyl acetate.

[0207] The content of each of the polycarbodiimide and polyaziridine is 0.2 to 50% by weight, preferably 0.5 to 15% by weight, and more preferably 1.0 to 10.0% by weight, based on the total weight of the polyfunctional polymer in the liquid composition.

[0208] The content of the polyfunctional polymer is 2 to 60% by weight, preferably 5 to 40% by weight, and more preferably 10 to 30% by weight, based on the total weight of the liquid composition.

[0209] The device includes a mechanism for maintaining the gel medium in a mechanically stable environment.

[0210] The device is a battery or an electrochromic or photochromic device, preferably the device is an electrochromic or photochromic device and is selected from optical articles such as optical lenses, optical filters, attenuators, windows, visors, mirrors (such as rear-view mirrors) and displays, preferably an optical lens, more preferably an optical lens for an ophthalmic lens or goggles.

[0211] The electrochromic device includes at least one transparent electrochromic cell comprising a pair of opposing substrates facing each other to form a gap, the gap being filled with a gel medium as defined above.

[0212] More generally, all the features mentioned above in relation to the gel medium also apply to the device, said device being another object of the invention, and conversely, all the features described below in relation to the device also apply to the gel medium.

[0213] Non-limiting examples of ophthalmic lenses include corrective lenses, such as single or multifocal lenses (i.e., afocal, unifocal, bifocal, trifocal, and progressive lenses), and non-corrective lenses (which may or may not be segmented), as well as contact lenses, intraocular lenses, magnifying lenses (such as contrast enhancing lenses in augmented or virtual reality devices), and other elements used to correct, protect, or enhance vision, such as protective lenses (such as sunglasses and sun lenses), or visors. Non-limiting examples of display elements and devices include screens and monitors. Non-limiting examples of windows include window filters, attenuators, shutters, and light switches in automobiles, boats, and aircraft. Non-limiting examples of mirrors are side mirrors, rearview mirrors, and other vehicle mirrors.

[0214] The device may include functional layers such as polarizing layers, photochromic layers, anti-reflective coatings, visible and UV absorbing coatings, impact resistant coatings, abrasion resistant coatings, anti-fouling coatings, anti-fog coatings, anti-dust coatings, etc., all of which are well known to those skilled in the art.

[0215] The device of the present invention may include a mechanism for holding the composition in a mechanically stable environment. For example, the electrochromic device of the present invention includes an electrochromic cell including two substrates facing each other. The substrate is preferably an optical substrate, such as any inorganic or organic glass commonly known and used in the optical field. It may be, for example, soda-lime glass or borosilicate inorganic glass. It may be a thermoplastic resin, such as thermoplastic polycarbonate (PC), PET, PEN, PMMA, COC, COP, PVDC, cellulose triacetate, or a thermosetting or photosetting resin, such as polyurethane, polyurethane / polyurea (such as TRIVEX®), or polythiourethane. When the electrochromic device is used as an ophthalmic lens, the substrate used to manufacture the cell may be spherical or aspherical. The inner side of the substrate may be coated with a transparent conductive electrode.The conductive electrodes are generally doped metal oxides having a formula containing oxygen atoms and at least two other elements in various proportions, and may be transparent conductive materials such as transparent conductive oxides ("TCOs"), e.g., indium tin oxide ("ITO"), fluorine doped tin oxide ("FTO"), aluminum doped zinc oxide ("AZO"), gallium doped zinc oxide ("GZO"), indium doped zinc oxide ("IZO"), aluminum gallium zinc oxide ("AGZO"), indium gallium zinc oxide ("IGZO"), antimony doped tin oxide ("ATO"), aluminum tin zinc oxide ("ATZO"), indium tin zinc oxide ("ITZO"), or insulator-metal-insulator ("IMI"), such as indium tin oxide / silver / indium tin oxide ("ITO / Ag / ITO"), or metal nanogrids based on copper, gold, silver, or graphene. The substrate may be formed of a metal, nanomesh, or nanowire, and / or an organic conductive polymer (such as PEDOT or its derivatives (e.g. PEDOT:PSS), other polythiophenes, polyanilines, polypyrroles, polyacetylenes, or mixtures thereof), or may comprise nanoparticles selected from metal nanoparticles, metal oxide nanoparticles, carbon nanotubes, graphene nanosheets, graphene oxide nanosheets, and mixtures thereof, preferably the metal oxide nanoparticles are ITO nanoparticles, SnO2 nanoparticles, ZnO nanoparticles, AZO nanoparticles, WO3 nanoparticles, or mixtures thereof, or additives that may be selected from surfactants, polyethylene glycol (PEG), ethylene glycol oligomers, ethylene glycol, DMSO, organic ionic liquids, or mixtures thereof. The substrates may be held at a fixed distance from each other using spacers, for example 10 μm to 400 μm, preferably 20 to 250 μm, more preferably 150 μm, to form a gap through which the electrochromic composition is introduced.

[0216] As defined herein, a nanomesh is an interconnected network of nanowires. Nanowires are nanostructures with a length to width ratio of at least 10 and widths ranging from 1 to 100 nm. To obtain acceptable transmittance, the thin metal layer should typically have a thickness of less than 50 nm. Nanomeshes can be obtained by methods known in the art, including deposition of a layer of a suspension of nanowires in a solvent, followed by solvent removal, for example by drying. Nanogrids are typically made by photolithographic techniques.

[0217] The gel medium can be injected into the device in its liquid state, for example, by using either a vacuum backfilling process or a drop injection process. If a vacuum buckfilling process is used to inject the solution into the cell, it is preferable to fabricate the cell with only one hole.

[0218] Another device of the invention comprises an optical component with at least one transparent cell arrangement juxtaposed in a direction parallel to its surface, each cell being sealed and containing said fluid, a mesomorphic or gel host medium and said at least one compound of the invention. Another device according to the invention can be a device according to patent FR 2 937 154 or FR 2 950 710, containing at least one compound of the invention.

[0219] use According to another aspect, the present invention provides a method for producing a method for manufacturing a pharmaceutical composition comprising: a multifunctional polymer comprising at least two carboxyl moieties capable of undergoing a crosslinking reaction, the multifunctional polymer having a molecular weight between 10,000 g / mol and 3,000,000 g / mol, preferably between 30,000 g / mol and 1,000,000 g / mol, more preferably between 50,000 g / mol and 400,000 g / mol; - a crosslinking agent selected from polycarbodiimides or non-toxic polyaziridines for the in situ preparation of a gel medium that acts as an electrolyte in said device, in order to obtain a medium of high cohesion so that deformation of the medium is limited or strongly reduced upon deformation of the device; This relates to the use of mixtures of

[0220] The use of such mixtures results in the in situ preparation of a gel medium that exhibits very good mechanical properties in bending and high ionic conductivity therein.

[0221] Preferably, said polyfunctional polymer has an acid value of 1 to 50 mg KOH / g, preferably 3 to 40 mg KOH / g, preferably 4 to 15 mg KOH / g. EXAMPLES

[0222] The present invention is further described by the following non-limiting examples, which are presented for illustrative purposes only and are not intended to limit the scope of the appended claims.

[0223] The formulation is prepared as follows: The electrochromic mixture (3.1%), a copolymer of vinyl acetate and crotonic acid sold by Wacker as Vinnapas® C501 (19.4%), and propylene carbonate (77.5%) are blended together at room temperature until all components are completely dissolved in the solvent. Propylene carbonate and an electrochromic mixture formed from ethyl viologen perchlorate and 10-methylphenothiazine, all available from Sigma Aldrich.

[0224] The resulting viscous liquid is mixed with 2% carbodiimide crosslinker relative to the total weight of the multifunctional polymer in the liquid composition. The carbodiimide crosslinker is a highly viscous liquid. The resulting composition is immediately used to fabricate an electrochromic device. After one hour at ambient temperature or after a few minutes at 50° C., the liquid at least partially gels sufficiently to allow the device thus obtained to be moved without optical defects. The device can then be removed from the assembly machine to undergo a post-curing step, for example in an oven. The device is post-cured, for example, overnight at 50° C.

[0225] The polycarbodiimide crosslinker used is sold under the trade name Picassian® XL725 by Stahl.

[0226] The curve shown in FIG. 1 shows the change in viscosity of the mixture as a function of time at room temperature.

[0227] After 24 hours, the electrochromic device is bent and activated for 100 hours. No defects are observed. More precisely, the mechanical deformation does not affect the uniformity of the coloring. [Brief description of the drawings]

[0228] [Figure 1] FIG. 2 shows the change in viscosity of the mixture as a function of time at room temperature.

Claims

1. at least one non-aqueous solvent present in said gel medium in an amount of at least 30% by weight based on the total weight of the gel medium; A crosslinked polymer, a multifunctional polymer comprising at least two carboxyl sites capable of undergoing a crosslinking reaction, said multifunctional polymer having a weight average molecular weight of between 2,000 g / mol and 3,000,000 g / mol; a crosslinking agent selected from polycarbodiimides or non-toxic polyaziridines; a crosslinked polymer obtained by the reaction of a redox chemical mixture dispersed in said crosslinked polymer in solution in said solvent, said mixture being comprised of at least one electrochromic reducing compound and at least one electrochromic oxidizing compound, and being in an activated state in the presence of an applied voltage and fading to an inactivated state in the absence of an applied voltage; An electrochromic gel medium comprising:

2. 2. The electrochromic gel medium of claim 1, wherein the multifunctional polymer comprising at least two carboxyl moieties is selected from carboxylic acid functional polyesters, carboxylic acid functional polyethers, carboxylic acid functional polyurethanes, carboxylic acid functional polyacrylates, carboxylic acid functional polymethacrylates, carboxylic acid functional polyvinyl acetate copolymers, copolymers made from ionic liquid monomers, combinations thereof or reaction products thereof or copolymers.

3. The multifunctional polymer is a. (Meth)acrylic acid monomer or C １ ~C ４ a substituted (meth)acrylic acid monomer; at least one ethylenically unsaturated organic carboxyl monomer containing from 3 to 9 carbon atoms and at least one carboxyl group, or - at least one C １ ~C １２ an alkyl (meth)acrylate monomer, or at least one ethylenically unsaturated C １ ~C １２ Alkenes, or at least one aromatic monoalkenyl monomer; and a copolymer prepared from b. a copolymer prepared from vinyl acetate monomer and at least one ethylenically unsaturated organic carboxyl monomer containing from 3 to 9 carbon atoms and at least one carboxyl group; c.C １ ~C １２ Copolymers prepared from alkyl vinyl ether monomers and at least one ethylenically unsaturated organic carboxyl monomer containing from 3 to 9 carbon atoms and at least one carboxyl group; d. Carboxybifunctional PEG or PPG derivatives; e. Multi-arm PEG or PPG carboxylic acid terminated derivatives: f. Poly(lactide-co-glycolide) (PLGA) carboxylic acid terminated derivatives; g. Multi-arm PLGA carboxylic acid-terminated derivatives; h. Poly(ε-caprolactone)-PEG carboxylic acid terminated derivatives; i. PLGA-PEG carboxylic acid terminated derivatives; j. PLA-PEG carboxylic acid terminated derivatives; k. polyester dendrimers with 2,2-bis(hydroxymethyl)propanoic acid (bis-MPA), trimethylolpropane, or pentaerythritol as the core; l. a polyurethane matrix containing at least two carboxyl sites resulting from the reaction of a polyol with an alkylene oxide isocyanate compound; or mixtures or reaction products thereof; 3. The electrochromic gel medium according to claim 1 or 2,

4. 4. The electrochromic gel medium of claim 3, wherein the multifunctional polymer is a copolymer of vinyl acetate and crotonic acid.

5. 5. The electrochromic gel medium of claim 1, wherein the crosslinking agent is a polycarbodiimide selected from oligomeric materials containing carbodiimide functional groups and hydrophilic segment groups that are not reactive to the carbodiimide functional groups.

6. 6. The electrochromic gel medium of claim 5, wherein the oligomeric material containing carbodiimide functional groups is further substituted with at least an alkylalkoxysilane or alkoxysilane group.

7. 7. The electrochromic gel medium of claim 1, wherein the electrochromic reducing compound is selected from ferrocene and derivatives thereof, phenoxazine and derivatives thereof, phenazine and derivatives thereof, phenothiazine and derivatives thereof, thioanthrene, thiophene and tetrathiafulvalene.

8. 8. The electrochromic gel medium according to claim 1, wherein the electrochromic oxidizing compound is selected from mono- or bis-viologens (i.e., 4,4'-bipyridinium salts or bis[4,4'-bipyridinium] salts), anthraquinones, benzazoles, imidazo[1,2-α]pyridines, 2,1,3-benzothiadiazoles, imidazoles, benzoselenadiazoles, benzoselenazoles, and derivatives thereof.

9. Electrochromic gel medium according to any one of claims 1 to 8, wherein the redox chemical mixture is composed of 10-methylphenothiazine and two electrochromic oxidizing compounds, the two electrochromic oxidizing compounds being either a compound of formula (I-10) and a compound of formula (II-10) or a compound of formula (I-38) and a compound of formula (II-10): 【Chemistry 1】

10. 10. The electrochromic gel medium of claim 1, wherein the non-aqueous solvent is propylene carbonate.

11. A method for producing an electrochromic device comprising the gel medium according to any one of claims 1 to 10, the gel medium comprising: (a) external to the device, said at least one non-aqueous solvent; said redox chemical mixture, a multifunctional polymer capable of undergoing a crosslinking reaction and containing at least two carboxyl sites, said multifunctional polymer having a weight average molecular weight of between 2,000 g / mol and 3,000,000 g / mol, said multifunctional polymer having an acid number of between 1 and 50 mg KOH / g; said crosslinking agent being chosen from polycarbodiimides or non-toxic polyaziridines; forming a liquid composition by mixing (b) placing the liquid composition of step (a) into the device and polymerizing the multifunctional polymer and the polycarbodiimide or polyaziridine, thereby forming a crosslinked polymer and forming a gel medium in which the compound and solvent are retained in a crosslinked polymer-containing matrix; A method formed by

12. The method according to claim 11, wherein the content of each of the polycarbodiimide or polyaziridine is 0.2 to 30% by weight based on the total weight of the multifunctional polymer in the liquid composition.

13. The method according to claim 11 or 12, wherein the content of the multifunctional polymer is 2 to 60% by weight based on the total weight of the liquid composition.

14. The method of any one of claims 11 to 13, wherein the electrochromic device is selected from an optical lens, an optical filter, an attenuator, a window, a visor, a mirror, and a display.

15. a multifunctional polymer comprising at least two carboxyl sites capable of undergoing a crosslinking reaction, said multifunctional polymer having a weight average molecular weight of between 10,000 g / mol and 3,000,000 g / mol; a crosslinker chosen from polycarbodiimides or non-toxic polyaziridines for the in situ preparation of an electrochromic gel medium that acts as an electrolyte in the electrochromic device in order to obtain a medium of high cohesion so that the deformation of said medium is limited or strongly reduced upon deformation of said device; Use of a mixture of.

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