COLOR-CHANGING POLYMER COMPOSITION AND ELECTROCHROMIC DEVICE COMPRISING THE SAME

Abstract

A color-changing polymer composition for an electrochromic device, comprising: an amount of 5 to 30 wt.% of a color-changing material; an amount of 0.01 to 1 wt% ferrocene; an amount of 10 to 30 wt.% of a polymer matrix; an amount of 20 to 70 wt.% of an ion-conducting material; and an amount of 1 to 10 wt.% of a polyhedral oligomeric silsesquioxane (POSS) derivative, all wt% are based on the total weight of the color-changing polymer composition.

Description

TECHNICAL FIELDThe present invention relates to a color-changing polymer composition and an electrochromic device containing the same. The color changing polymer composition can be used in a paint-like spray coating process.BACKGROUNDRecently, the importance of marketing color has increased in various fields such as home appliances, mobile appliances, and the like. In particular, in the automobile industry, the need to use paint for marketing purposes is required for the luxus and differentiation of paint. Accordingly, attempts are being made to provide novel colors by means of electrochromic.Electrochromic is a phenomenon in which a reversible color change occurs when an oxidation or reduction reaction is electrochemically induced in an electrode material. For example, when Li + or H + and electrons are injected in WO 3, which is a typical reduction dye, a color is formed due to electrochromicity and transparency is restored upon release thereof, whereas in an oxidation dye such as MnO, LiO and the like, a color is formed upon release of Li + or H + and electrons and transparency is restored upon injection thereof.A general electrochromic device is provided in the form of a laminated structure of a substrate / an electroconductive layer / an ion electrolyte and a color-changing material layer / an electroconductive layer / a substrate.However, the conventional electrochromic device is limited in that it must be formed on a smooth and flat substrate such as glass or a film because the material of which the individual layers are formed and the manufacturing method thereof are limited, making it difficult to use various substrate materials. In addition, when a substrate material having a distorted surface is used, it is impossible to produce and form a material thereon.KR 10 2014 0 027 671 A discloses a polymer electrolyte for lithium secondary batteries. KR 10 2016 0 007 336 A describes a binder for lithium secondary batteries.The background information is provided to aid in understanding the background of the invention and is not to be taken as an admission that the details described correspond to the state of the art already known to those skilled in the art.SUMMARY OF THE INVENTIONThe invention provides a color-changing polymer composition and an electrochromic device containing the same.In one aspect, a color-changing polymer composition for an electrochromic device is provided. The color-change polymer composition contains: an amount of about 5 to 30 wt% of a color-change material; an amount of about 0.01 to 1 wt% ferrocene; an amount of about 10 to 30 wt% of a polymer matrix; an amount of about 20 to 70 wt% of an ion-conducting material; and an amount of about 1 to 10 wt% of a POSS (polyhedral oligomeric silsesquioxane) derivative, wt%, based on the total weight of the composition.The color change material may correspondingly contain octahexylviologen polyhedral oligomeric silsesquioxane (OHV-POSS) containing one to eight monohexylviologens at the reactive functional group of POSS (polyhedral oligomeric silsesquioxane).The ferrocene may correspondingly contain ferrocene substituted with an alkyl group.The polymer matrix may suitably contain one or more selected from polyvinylidene fluoride (PVDF) and derivatives thereof, polymethyl methacrylate (PMMA) and derivatives thereof, and polyvinyl alcohol (PVA).The ion conducting material may contain one or more room temperature ionic liquids and a lithium salt.The POSS (polyhedral oligomeric silsesquioxane) derivative may contain one or more groups selected from alkyl, vinyl, and glycidyl.The color-changing polymer composition may further contain a solvent component, and the solvent component may contain one or more selected from isopropyl alcohol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).In one aspect, an electrochromic device is provided. The electrochromic device includes: a color-changing layer formed of a color-changing polymer composition according to the above aspect; and a first electrode layer and a second electrode layer formed on the respective surfaces of the color-changing layer.Each of the first electrode layer and the second electrode layer may be formed of a transparent electrode layer composition containing an amount of about 30 to 80 wt % of a silver nanowire (1%) suspension, an amount of about 10 to 60 wt % of a PEDOT:PSS (1-2%) suspension, an amount of about 0.001 to 10 wt % of glycerin, an amount of about 0.001 to 10 wt % of ethylene glycol, an amount of about 0.001 to 10 wt % of dodecylbenzenesulfonic acid, an amount of about 0.001 to 10 wt % of divinyl sulfone, and an amount of about 0.001 to 10 wt % of dimethyl sulfoxide based on the total weight of the transparent electrode layer composition.The electrochromic device may further include an ion conductive layer formed between the color-changing layer and the first electrode layer.The ion-conducting layer may be formed from an ion-conducting composition containing an amount of about 20 to 40 wt % of a polymer matrix, an amount of about 20 to 40 wt % of a reactive POSS (polyhedral oligomeric silsesquioxane) material, an amount of about 20 to 40 wt % of a lithium salt, and an amount of about 0 to 20 wt % (excluding 0 wt %) of a room temperature ionic liquid based on the total weight of the ion-conducting composition.The electrochromic device may further include a clear coating layer formed on the surface of the first electrode layer.The clear coating layer may correspondingly contain one or more selected from polycarbonate, polystyrene, polyethylene and polyester.The electrochromic device may further include a silver mesh layer formed between the first electrode layer and the clear coating layer.According to various exemplary embodiments of the present invention, by developing respective compositions that can be used for painting in a spray coating method to form a color-changing layer, an ion-conductive layer, and an electrode layer constituting an electrochromic device, effects in manufacturing an electrochromic device having different structures can be expected.Further aspects of the invention are described infra.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 illustrates an exemplary electrochromic device according to an exemplary embodiment of the present invention; FIG. 2 shows an exemplary electrochromic device according to an exemplary embodiment of the present invention; and FIG. 3 shows an exemplary electrochromic device according to an exemplary embodiment of the present invention.DESCRIPTION OF SPECIFIC EMBODIMENTSThe terminology used herein is for describing particular exemplary embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" also include the plural forms, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of particular features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. As used herein, the term "and / or" includes any combination of one or more of the listed items.Unless expressly stated or evident from context, the term "about" is understood herein to be within a normal tolerance range, e.g., within 2 standard deviations of the mean. "About" may be understood to be within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless the context indicates otherwise, all numerical values indicated here are modified by the term "about".It is understood that the term "vehicle" or "vehicle... " or similar term as used herein is inclusive of motor vehicles in general such as passenger cars including sports utility vehicles (SUVs), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). A hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.In the present specification, when describing a range for a variable, it is assumed that the variable includes all values including the described end points within the specified range. For example, the range "5 to 10" includes all sub-ranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., and single widths of 5, 6, 7, 8, 9, and 10, and also includes all values between valid integers within the stated range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, etc. The range "10% to 30%" includes sub-ranges such as 10% to 15%, 12% to 18%, 20% to 30%, etc., and all integers having values of 10%, 11%, 12%, 13%, etc., up to 30%, and also includes any value between valid integers within the stated range, such as 10.5%, 15.5%, 25.5%, etc.Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments, and may be changed to have a variety of different forms. These embodiments are provided to complete the disclosure of the present invention and to fully describe the present invention to those skilled in the art.As used herein, a "color-changing polymer composition" refers to a composition used for forming a color-changing layer of an electrochromic device. The color-change polymer composition may further contain a solvent component to form a color-change layer by using a spray coating method. In particular, the color-changing polymer composition can change its color depending on the applied voltage and the applied current.The color-change polymer composition contains an amount of 5 to 30 wt% of a color-change material, an amount of 0.01 to 1 wt% ferrocene, an amount of 10 to 30 wt% of a polymer matrix, an amount of 20 to 70 wt% of an ion conducting material, and an amount of 1 to 10 wt% of a POSS (polyhedral oligomeric silsesquioxane) derivative based on the total weight of the composition.The color-changing polymer composition composed of the components in the above-described amounts may further contain or be mixed with a solvent component so that it can be used for painting for the purpose of spray coating.The color-change polymer composition including the solvent component may contain an amount of 0.1 to 10 wt% of the color-change material, an amount of 0.01 to 1 wt% ferrocene, an amount of 0.1 to 10 wt% of the polymer matrix, an amount of 0.1 to 10 wt% of the ion conducting material, an amount of 0.1 to 5 wt% of the POSS (polyhedral oligomeric silsesquioxane) derivative, and the balance of the solvent that can be used for painting.Preferably, the color-change polymer composition including the solvent component may contain an amount of 0.1 to 2.0 wt% of the color-change material, an amount of 0.01 to 0.05 wt% ferrocene, an amount of 1.0 to 3.0 wt% of the polymer matrix, an amount of 4 to 10 of the ion-conducting material, an amount of 0.3 to 0.7 wt% of the POSS (polyhedral oligomeric silsesquioxane) derivative, and an amount of 80 to 92 wt% of the solvent. Based on the total weight of the compositionThe color change material may correspondingly contain octahexylviologen polyhedral oligomeric silsesquioxane (OHV-POSS) containing 1 to 8 monohexylviologens substituted on the reactive functional group of POSS (polyhedral oligomeric silsesquioxane). In particular, by changing the chemical structure of the color-changing material, various colors such as blue, green and red can be realized. When the amount of the color-changing material is less than the above lower limit, the detectable color change may deteriorate, while when the amount thereof is greater than the above upper limit, the solution may be saturated and agglomeration may occur, resulting in decreased solubility.Ferrocene as used herein is an oxidizing aid. Preferably, the ferrocene may contain ferrocene substituted with an alkyl group. When the amount of ferrocene is less than the above lower limit, the oxidation-reduction reaction may not be compensated and thus the stability of the color change may deteriorate, while when the amount of ferrocene is greater than the above upper limit, neutral transmission may decrease due to the intrinsic yellow color thereof.The polymer matrix may suitably contain one or more selected from polyvinylidene fluoride (PVDF) and derivatives thereof, polymethyl methacrylate (PMMA) and derivatives thereof, and polyvinyl alcohol (PVA). When the amount of the polymer matrix is less than the above lower limit, film formation may be insufficient, while when the amount of the polymer matrix is greater than the upper limit, the activity of the color-changing layer may decrease, resulting in deteriorated color-changing performance.The ion conducting material may correspondingly contain one or more room temperature ionic liquids and a lithium salt. When the amount of the ion conductive material is less than the above lower limit, the ion conductivity is low so that a color change does not occur, while when the amount of the ion conductive material is above the above upper limit, the mechanical properties of the color-changing layer may deteriorate.The POSS derivative used herein can improve the mechanical strength and conductivity of the color-changing layer and may contain one or more substituted groups selected from alkyl, vinyl and glycidyl groups. When the amount of the POSS derivative is less than the above lower limit, curing may be deteriorated, while when the amount thereof is more than the upper limit, the time to color change due to a decrease in the movement of electrons and ions may be prolonged.The solvent component may be included or admixed to produce a color-changing polymer composition for use in spray coating finishes. The solvent component may suitably contain one or more selected from isopropyl alcohol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). When the amount of the solvent is less than the above lower limit, clogging of the nozzles may often occur in spraying, while when the amount of the solvent is greater than the above upper limit, film formation and curing may be delayed due to the diluted concentration.As used herein, the term "ion-conductive composition" refers to a composition used to form an ion-conductive layer of an electrochromic device. The ion conductive composition may further contain or be mixed with a solvent component to form an ion conductive layer by using a spray coating method.The ion conducting composition may correspondingly contain an amount of about 20 to 40 wt % of a polymer matrix, an amount of about 20 to 40 wt % of a reactive POSS (polyhedral oligomeric silsesquioxane) material, and an amount of about 20 to 40 wt % of a lithium salt. The ion conductive composition may further contain an amount of about 20 wt % or less of a room temperature ionic liquid.The ion conducting composition may contain or be mixed with the solvent component for use in painting for purposes of spray coating. The ion conductive layer formed by subjecting the ion conductive composition composed of the components in the above-described amounts to spray coating has a high surface hardness, so that damage thereof does not occur in the additional spray coating process for forming an electrode layer.The ion conductive composition including the solvent component may correspondingly contain an amount of about 5 to 20 wt % of the polymer matrix, an amount of about 5 to 20 wt % of the reactive POSS (polyhedral oligomeric silsesquioxane) material, an amount of about 5 to 20 wt % of the lithium salt, and the balance of the solvent based on the total weight of the composition. The ion-conducting composition may also further contain an amount of about 20 wt % or less of the room temperature ionic liquid based on the total weight of the composition.Preferably, the ion conducting composition including the solvent component may suitably contain an amount of about 5 to 15 wt% of the polymer matrix, an amount of about 5 to 15 wt% of the reactive POSS material, an amount of about 5 to 15 wt% of the lithium salt, and an amount of about 80 to 96 wt% of the solvent.The polymer matrix may suitably contain one or more selected from polyvinylidene fluoride (PVDF) and derivatives thereof, polymethyl methacrylate (PMMA) and derivatives thereof, and polyvinyl alcohol (PVA). When the amount of the polymer matrix is less than the above lower limit, film formation may be insufficient, while when the amount of the polymer matrix is greater than the above upper limit, the activity of the ion conductive layer may decrease, resulting in deteriorated color changing performance.The reactive POSS material may correspondingly include one or more selected from glycidyl POSS, acrylic POSS, octaphenyl POSS, isocyanate POSS and alkyl POSS. When the amount of the reactive POSS material is less than the above lower limit, the amount of curing in forming the ion conductive layer may decrease, while when the amount of the reactive POSS material is greater than the above upper limit, the time to color change due to a decrease in the movement of electrons and ions may be prolonged.The lithium salt may form ions that move in the ion conducting layer. When the amount of the lithium salt is less than the above lower limit, the ionic conductivity may decrease, while when the amount of the lithium salt is greater than the above upper limit, the transmittance due to saturation may decrease and the detectable color change may decrease. Here, the lithium salt may include two or more selected from the group consisting of LiPF 6, LiB 4, LiClO 4, LiCl, LiBr, LiI, LiB 10 Cl 10, LiCF 3 SO 3, LiCF 3 CO 2, LiAsF 6, LiNbF6, LiAlCl4, CH3SO3Li, CF3SO3Li, LiN(SO 2 C 2 F 5)2, Li(CF 3 SO 2)2 N, LiC 4 F 9 SO 3, LiB(C 6 H 5)4, Li(SO2F)2N (LiFSI), and (CF3SO2)2NLi.The solvent component may be included or admixed to produce an ion conducting composition used in spray coating finishes. The solvent component may correspondingly contain at least one selected from isopropyl alcohol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). When the amount of the solvent is less than the above lower limit, clogging of the nozzles may often occur in spraying, while when the amount of the solvent is greater than the above upper limit, film formation and curing may be delayed due to the diluted concentration.The term "transparent electrode layer composition" refers to a composition used for forming an electrode layer of an electrochromic device. The transparent electrode layer composition may be contained in or mixed with a solvent component to form an electrode layer by using a spray coating method.The transparent electrode layer composition may include an amount of about 30 to 80 wt % of a silver nanowire (1%) suspension, an amount of about 10 to 60 wt % of a PEDOT:PSS (1-2%) suspension, an amount of about 0.001 to 10 wt % of glycerin, an amount of about 0.001 to 10 wt % of ethylene glycol, an amount of about 0.001 to 10 wt % of dodecylbenzenesulfonic acid, an amount of about 0.001 to 10 wt % of divinylsulfone, and an amount of about 0.001 to 10 wt % of dimethyl sulfoxide based on the total weight of the composition.Preferably, the transparent electrode layer composition may contain an amount of about 30 to 50 wt % of the silver nanowire (1%) suspension, an amount of about 39 to 59 wt % of the aqueous PEDOT:PSS (1-2%) suspension, an amount of about 5 to 7.5 wt % of glycerin, an amount of about 2.5 to 3.75 wt % of ethylene glycol, an amount of about 0.25 to 0.375 wt % of dodecylbenzenesulfonic acid, an amount of about 0.25 to 0.375 wt % of divinyl sulfone, and an amount of about 2.5 to 3.75 wt % of dimethyl sulfoxide based on the total weight of the composition.The transparent electrode layer composition may further contain or be mixed with a solvent to be used as a paint for spray coating.The transparent electrode layer composition including a solvent component may contain an amount of about 1 to 30 wt % of the silver nanowire (1%) suspension, an amount of about 1 to 30 wt % of the PEDOT:PSS (1-2%) suspension, an amount of about 0.001 to 3 wt % of glycerin, an amount of about 0.001 to 3 wt % of ethylene glycol, an amount of about 0.001 to 3 wt % of dodecylbenzenesulfonic acid, an amount of about 0.001 to 3 wt % of divinyl sulfone, an amount of about 0.001 to 3 wt % of dimethyl sulfoxide, and the balance of the solvent based on the total weight of the composition.When the amount of the silver nanowire (1%) suspension is less than the above lower limit, conductivity may decrease, while when the amount thereof is greater than the above upper limit, transmission may be lowered.When the amount of the PEDOT:PSS (1-2%) suspension is less than the above lower limit, conductivity may decrease and the surface roughness of the electrode layer may deteriorate, while when the amount of the PEDOT:PSS (1-2%) suspension is greater than the above upper limit, a blue color may occur and thus the detectable color change may decrease.Glycerol and ethylene glycol are used as additives for the PEDOT:PSS (1-2%) suspension. When the amounts of glycerin and ethylene glycol are within the above ranges, an excellent effect for improving the conductivity of the PEDOT:PSS (1-2%) suspension can be obtained. However, if the amounts thereof fall outside the above ranges, the effect of conductivity improvement may deteriorate and the conductivity of the electrode layer may decrease.When the amount of dodecylbenzenesulfonic acid is less than the above lower limit, dispersibility of the solution may deteriorate, while when the amount thereof is greater than the above upper limit, agglomeration may occur due to the reaction with the PEDOT:PSS (1-2%) suspension.Divinyl sulfone can make the surface of the electrode layer hard by a crosslinking reaction with an additive. When the amount of divinyl sulfone is less than the above lower limit, curing may not sufficiently occur, while when the amount thereof is greater than the above upper limit, overcure may occur.The solvent component may be contained or blended to produce a transparent electrode layer composition for use in spray coating paints. The solvent component may suitably contain one or more selected from isopropyl alcohol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO). When the amount of the solvent is less than the above lower limit, clogging of the nozzles may often occur in spraying, while when the amount of the solvent is greater than the above upper limit, film formation and curing may be delayed due to the diluted concentration.Using the color-changing polymer composition, the ion-conductive composition, and the transparent electrode layer composition as described above, a laminated electrochromic device can be produced by spray coating. In particular, since a spray coating method can be applied, an electrochromic device can be formed on various substrate materials, and the configuration like the substrate can be eliminated.FIG. 1 shows an exemplary electrochromic device according to an exemplary embodiment of the present invention, FIG. 2 shows an exemplary electrochromic device according to an exemplary embodiment of the present invention, and FIG. 3 shows an exemplary electrochromic device according to an exemplary embodiment of the present invention.As shown in FIG. 1, the electrochromic device includes a color-changing layer 200 formed of the color-changing polymer composition, and a first electrode layer 100 and a second electrode layer 300 formed of the transparent electrode layer composition on respective surfaces of the color-changing layer 200.In addition, as shown in FIG. 2, the electrochromic device may further include an ion conductive layer 400 formed of the ion conductive composition between the color-changing layer 200 and the first electrode layer 100, and a clear coating layer 500 formed on the surface of the first electrode layer 100.In addition, as shown in FIG. 3, the electrochromic device may further include a silver mesh layer 600 formed between the first electrode layer 100 and the clear coating layer 500, and a substrate 700 formed under the second electrode layer 300.The color-change layer 200 is a layer in which a color change actually occurs depending on the applied voltage and the applied current, and can be formed by mixing the color-change polymer composition as described above. For example, the color-change polymer composition may contain an amount of about 5 to 30 wt % of the color-change material, an amount of about 0.01 to 1 wt % ferrocene, an amount of about 10 to 30 wt % of the polymer matrix, an amount of about 20 to 70 wt % of the ion-conducting material, an amount of about 1 to 10 wt % of the POSS (polyhedral oligomeric silsesquioxane) derivative, and a solvent component, followed by spray coating.The color-changing layer 200 contains a color-changing material, which is a hybrid organic / inorganic material in which POSS as an inorganic material and viologen as an organic material are bonded to each other, and electrochromic properties are imparted by substituting 1 to 8 monohexylviologens as an electrochromic material at the reactive organic functional group around POSS. The octahexylviologen polyhedral oligomeric silsesquioxane (OHV-POSS) in the color-changing material has advantages that a short time can be required for color change, low voltage driving is possible, and high color efficiency can be exhibited.The first electrode layer 100 and the second electrode layer 300 are layers serving as electrodes for transferring oxidation and reduction potentials, which can be formed by mixing the transparent electrode layer composition as described above and spray coating. For example, the transparent electrode layer composition may include an amount of about 30 to 80 wt % of the silver nanowire (1%) suspension, an amount of about 10 to 60 wt % of the PEDOT:PSS (1-2%) suspension, an amount of about 0.001 to 10 wt % of glycerin, an amount of about 0.001 to 10 wt % of ethylene glycol, an amount of about 0.001 to 10 wt % of dodecylbenzenesulfonic acid, an amount of about 0.001 to 10 wt % of divinyl sulfone, an amount of about 0.001 to 10 wt % of dimethyl sulfoxide, and a solvent component based on the total weight of the transparent electrode layer composition. For example, a paint solution obtained by mixing the transparent electrode layer composition with the solvent may be applied by spraying and then heat-treated at low temperature (80° C.) to form an electrode layer having a mirror-like surface and a sheet resistance of about 3 Ω.The first electrode layer 100 and the second electrode layer 300 are transparent electrode layers and have a transmittance of 80% or more and a relatively uniform and improved electrical conductivity by filling gaps between silver nanowires, which are a metal material, with PEDOT:PSS, which is an organic conductive polymer material, due to the use of a composite of poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) and silver nanowires. Divinyl sulfone may be added as a crosslinking agent to allow formation of an independent conductive film by reaction with PEDOT:PSS, improve stability of the film, maintain conductivity, and improve mechanical properties.The ion conductive layer 400 is a layer that stores ions to realize charge balancing depending on electron movement, and may be formed by mixing the ion conductive composition as described above and spray coating. The ion-conducting composition may include an amount of about 20 to 40 wt % of the polymer matrix, an amount of about 20 to 40 wt % of the reactive POSS (polyhedral oligomeric silsesquioxane) material, an amount of about 20 to 40 wt % of the lithium salt, and the solvent, based on the total weight of the ion-conducting composition.This ion conductive layer 400 contains a thermosetting ion conductive layer composition by using glycidyl POSS and electrolyte LiTFSI so that a paint-like spraying method can be applied, and by adding PVDF-HFP used as a polymer matrix in the color-changing material layer, a film can be formed efficiently.The polymer matrix, the reactive POSS (polyhedral oligomeric silsesquioxane) material, and the lithium salt may each have the greatest ionic conductivity when mixed in a weight ratio of 1:1:1.The clear coating layer 500 is located at the outermost position of the electrochromic device to protect the electrochromic device and impart repeatable, variable properties, and contains an acrylic composition that is photo-curable or thermosetting and has a high surface hardness.For example, the clear coating layer 500 may include one or more selected from polycarbonate, polystyrene, polyethylene, and polyester.The silver mesh layer 600 is formed to change the time required for changing colors and patterns, and may be formed in a silver mesh or line structure.The substrate 700 is a base material constituting an electrochromic device, and various substrates may be used. Since all the individual layers constituting the electrochromic device can be formed by spray coating, it is possible to use not only a smooth and flat glass or film substrate but also a substrate having a somewhat rough surface, a curved surface or a distorted structure. Accordingly, the electrochromic device is expected to be widely usable and to be used in technical fields such as flexible displays.Moreover, individual layers constituting the electrochromic device can be provided with design elements such as patterns by using a mask in spray coating.

Claims

A color-changing polymer composition for an electrochromic device, comprising: an amount of 5 to 30 wt% of a color-changing material; an amount of 0.01 to 1 wt% of ferrocene; an amount of 10 to 30 wt% of a polymer matrix; an amount of 20 to 70 wt% of an ion-conducting material; and an amount of 1 to 10 wt% of a polyhedral oligomeric silsesquioxane (POSS) derivative, all wt% based on the total weight of the color-changing polymer composition.The color-change polymer composition of claim 1, wherein the color-change material comprises octahexylviologen polyhedral oligomeric silsesquioxane (OHV-POSS) containing one to eight monohexylviologens at a reactive functional group of POSS.The color-change polymer composition of claim 1, wherein the ferrocene comprises ferrocene substituted with an alkyl group.The color-changing polymer composition according to claim 1, wherein the polymer matrix comprises one or more selected from polyvinylidene fluoride (PVDF) and derivatives thereof, polymethyl methacrylate (PMMA) and derivatives thereof, and polyvinyl alcohol (PVA).The color-change polymer composition of claim 1, wherein the ion-conducting material comprises one or more of a room temperature ionic liquid and a lithium salt.The color-change polymer composition of claim 1, wherein the POSS derivative comprises one or more substituted alkyl, vinyl and glycidyl groups.The color-changing polymer composition according to claim 1, wherein the color-changing polymer composition further comprises a solvent component, and the solvent comprises one or more selected from the group consisting of isopropyl alcohol (IPA), ethanol, methanol, acetone, toluene, methyl ethyl ketone (MEK), ethyl acetate, methyl isobutyl ketone (MIBK), dimethylformamide (DMF), and dimethyl sulfoxide (DMSO).An electrochromic device comprising: a color-changing layer formed of a color-changing polymer composition according to claim 1; and a first electrode layer and a second electrode layer formed on the respective surfaces of the color-changing layer.The electrochromic device according to claim 8, wherein each of the first electrode layer and the second electrode layer is formed of a transparent electrode layer composition comprising an amount of 30 to 80 wt% of a silver nanowire suspension, an amount of 10 to 60 wt% of a PEDOT:PSS suspension, an amount of 0.001 to 10 wt% of glycerin, an amount of 0.001 to 10 wt% of ethylene glycol, an amount of 0.001 to 10 wt% of dodecylbenzenesulfonic acid, an amount of 0.001 to 10 wt% of divinylsulfone, and an amount of 0.001 to 10 wt% of dimethyl sulfoxide, based on the total weight of the transparent electrode layer composition.The electrochromic device of claim 8, further comprising an ion conductive layer formed between the color-changing layer and the first electrode layer.The electrochromic device of claim 10, wherein the ion-conducting layer is formed from an ion-conducting composition comprising an amount of 20 to 40 wt% of a polymer matrix, an amount of 20 to 40 wt% of a reactive POSS material, an amount of 20 to 40 wt% of a lithium salt, and an amount of greater than 0 to 20 wt% of a room temperature ionic liquid, based on the total weight of the ion-conducting composition.The electrochromic device according to claim 8, further comprising a clear coating layer formed on a surface of the first electrode layer.The electrochromic device of claim 12, wherein the clear coating layer comprises one or more materials selected from polycarbonate, polystyrene, polyethylene, and polyester.The electrochromic device of claim 12, further comprising a silver mesh layer formed between the first electrode layer and the clear coating layer.

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