Composite for stretchable electrochromic device, manufacturing method of stretchable electrochromic member and stretchable electrochromic device manufactured through the method

Abstract

The present invention relates to a flexible electrochromic device composition, a method for manufacturing an electrochromic member, and a flexible electrochromic device manufactured thereby. One embodiment includes propylene carbonate (PC) and ethylene carbonate (EC).

Description

Technology Field

[0001] The present invention relates to a flexible electrochromic device composition, a method for manufacturing an electrochromic member, and a flexible electrochromic device manufactured thereby. One embodiment includes propylene carbonate (PC) and ethylene carbonate (EC). Background Technology

[0002] An electrochromic device is a device that contains an electrochromic material and changes color in response to an externally applied voltage. Various materials, such as polymer compounds and metal oxides, are used for the electrochromic material, and the color changes reversibly in response to the voltage applied to the electrode.

[0003] Recently, the application fields of these electrochromic devices are expanding, such as being used in smart window systems that block external views and sunlight, or in automotive glass that displays information like maps and text.

[0004] Conventional electrochromic devices utilize liquid electrochromic materials, which leads to electrolyte leakage and limits their use as flexible displays. Although solidified water-based electrolytes have recently been developed, the ease with which water evaporates necessitates the installation of an additional protective layer to prevent this. Prior art literature

[0005] Korean Registered Patent Publication No. 10-2078481 The problem to be solved

[0006] The present invention aims to provide a flexible electrochromic device composition with improved color change efficiency and color change speed, a method for manufacturing an electrochromic member, and a flexible electrochromic device manufactured thereby.

[0007] In addition, the present invention has light transmittance and elasticity.

[0008] In addition, it has a long lifespan and excellent durability.

[0009] In addition, its flexibility and elasticity allow for application in various fields.

[0010] In addition, the simple manufacturing method allows for increased production efficiency and reduced manufacturing costs. means of solving the problem

[0011] An electrochromic element composition according to an embodiment of the present invention comprises a polymer resin, a color-changing material, a main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC).

[0012] The above-mentioned main plasticizer may be dibutyl adipate (DBA).

[0013] The above propylene carbonate may be included in an amount of 2 to 8 weight percent, preferably 4 to 6 weight percent, with respect to the weight of the main plasticizer.

[0014] The above ethylene carbonate may be included in an amount of 2 to 8 weight percent, preferably 4 to 6 weight percent, relative to the weight of the main plasticizer.

[0015] The above propylene carbonate may be included in an amount of 25 to 75 weight percent relative to the weight of the polymer resin.

[0016] The above ethylene carbonate may be included in an amount of 25 to 75 weight percent relative to the weight of the polymer resin.

[0017] The weight ratio of the propylene carbonate and ethylene carbonate may be 3:1 to 1:3, preferably 6:4 to 4:6, and more preferably 1:1.

[0018] The above polymer resin may include at least one of polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), and polyethylene terephthalate (PET).

[0020] A method for manufacturing an electrochromic member according to an embodiment of the present invention comprises the steps of: preparing a mixture by dissolving a polymer resin in a solvent; adding a plasticizer to the mixture; and adding a color-changing material to the mixture.

[0021] The above plasticizers are the main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC).

[0022] The step of adding the plasticizer may include the step of adding a main plasticizer to the mixture and the step of adding propylene carbonate and ethylene carbonate to the mixture to which the main plasticizer has been added.

[0024] An electrochromic element according to an embodiment of the present invention comprises an electrochromic element layer, wherein the electrochromic element layer is prepared by drying an electrochromic element composition comprising a polymer resin, a color-changing material, a main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC). Effects of the invention

[0025] A flexible electrochromic element composition and a method for manufacturing an electrochromic member according to an embodiment of the present invention can provide a flexible electrochromic element with improved color change efficiency and color change speed.

[0026] In addition, the present invention has light transmittance and elasticity.

[0027] In addition, it has a long lifespan and excellent durability.

[0028] In addition, its flexibility and elasticity allow for application in various fields.

[0029] In addition, the simple manufacturing method allows for increased production efficiency and reduced manufacturing costs. Brief explanation of the drawing

[0030] FIG. 1 illustrates a method for manufacturing an electrochromic member according to an embodiment of the present invention. Figure 2 shows the measurement results of ionic conductivity. Figure 3 shows the measurement results of light transmittance. Figure 4 shows the discoloration efficiency. Specific details for implementing the invention

[0031] Hereinafter, preferred embodiments of the present invention are described as follows with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. Furthermore, embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

[0033] Electrochromic element composition

[0034] An electrochromic device composition according to an embodiment of the present invention comprises a polymer resin, a color-changing material, a main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC). One embodiment may further comprise an ionic liquid. Additionally, one embodiment may further comprise general additives used in the field for manufacturing electrochromic devices, such as a reducing agent.

[0036] The above polymer resin forms the basic body in the electrochromic device composition. The above polymer resin may possess light transmittance, flexibility, and elasticity when plasticized by a plasticizer. To this end, the above polymer resin may be at least one of polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), and polyethylene terephthalate (PET). In particular, high light transmittance, flexibility, and elasticity can be achieved by using polyvinyl chloride (PVC). The above polyvinyl chloride can be represented by the following structural formula 1.

[0037] [Structural Formula 1]

[0038]

[0039] (n is a natural number)

[0041] The present invention comprises a main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC) as plasticizers. A plasticizer is a substance that plasticizes the polymer resin.

[0043] The above-mentioned main plasticizer is not specifically limited but may be dibutyl adipate (DBA).

[0044] The above dibutyl adipate can be represented by the following structural formula 2.

[0045] [Structural Formula 2]

[0046]

[0047] The content of the main plasticizer may be 700 to 1200 parts by weight, preferably 700 to 1000 parts by weight, and more preferably 700 to 900 parts by weight, based on 100 parts by weight of the polymer resin. If the content of the main plasticizer is too low, crystals may easily form in the manufactured electrochromic device, and if the content of the main plasticizer is too high, mechanical properties may decrease.

[0049] The above propylene carbonate (PC) improves the color change speed and color change efficiency by increasing the ionic conductivity of the electrochromic device. The above propylene carbonate can be represented by Structural Formula 3.

[0050] [Structural Formula 3]

[0051]

[0052] The above propylene carbonate may be included in an amount of 2 to 8 weight%, preferably 4 to 6 weight%, relative to the weight of the main plasticizer. Additionally, the above propylene carbonate may be included in an amount of 25 to 75 weight% relative to the weight of the polymer resin. If the content of the above propylene carbonate is too high, leakage and clouding of the gel occur, and if the content is too low, the ion conductivity is not sufficiently improved.

[0054] The above ethylene carbonate (EC) is a material having a high dielectric constant and increases the number of free ions in an electrochromic device. The above ethylene carbonate can be represented by structural formula 4.

[0055] [Structural Formula 4]

[0056]

[0057] The above ethylene carbonate may be included in an amount of 2 to 8 weight%, preferably 4 to 6 weight%, relative to the weight of the main plasticizer. Additionally, the above ethylene carbonate may be included in an amount of 25 to 75 weight% relative to the weight of the polymer resin. If the content of the ethylene carbonate is too high, there is a problem where a solid forms on the surface of the gel because it does not melt, and if the content is too low, the ion conductivity is not sufficiently improved.

[0059] In the present invention, the weight ratio of the propylene carbonate and ethylene carbonate may be 3:1 to 1:3, preferably 6:4 to 4:6, and more preferably 1:1. In this content range, the ionic conductivity, color change speed, and color change efficiency of the electrochromic element are most excellent.

[0061] In one embodiment of the present invention, the discoloration material may be a material used for discoloring the polymer gel, and according to one embodiment of the present invention, DHV[TFSI]2 may be used, but is not limited thereto. Meanwhile, the DHV[TFSI]2 may be represented by the following structural formula 5.

[0062] [Structural Formula 5]

[0063]

[0064] The content of the above-mentioned discoloration substance may be 5 to 100 parts by weight, preferably 10 to 20 parts by weight, per 100 parts by weight of polymer resin.

[0066] In one embodiment, the electrochromic device composition may further include an ionic liquid. An ionic liquid is a material that can enhance the movement of ions and electrons while generally remaining in a non-volatile liquid state at 100°C or lower. Various types of ionic liquids may be used, but preferably, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (EMIM-TFSI) may be used. By limiting the ionic liquid in this way, the light transmittance of the electrochromic device layer can be maintained at a high level. The EMIM-TFSI can be represented by the following structural formula 6.

[0067] [Structural Formula 6]

[0068]

[0069] The content of the ionic liquid may be 100 to 200 parts by weight, preferably 110 to 130 parts by weight, per 100 parts by weight of the polymer resin. If the content of the ionic liquid is too high, the light transmittance may decrease.

[0071] In one embodiment, the electrochromic element composition may further include a reducing agent, and the reducing agent may be an anode redox compound. The anode redox compound may be either ferrocene or dimethyl ferrocene (dmFC), and preferably may be dimethyl ferrocene. The dimethyl ferrocene can be represented by the following structural formula 7.

[0072] [Structural Formula 7]

[0073]

[0074] The content of the above anode redox compound may be 1 to 20 parts by weight, preferably 12 to 18 parts by weight, per 100 parts by weight of the polymer resin.

[0076] Method for manufacturing an electrochromic material

[0077] A method for manufacturing an electrochromic member according to an embodiment of the present invention comprises the steps of: preparing a mixture by dissolving a polymer resin in a solvent; adding a plasticizer to the mixture; and adding a color-changing material to the mixture. The plasticizer is a primary plasticizer, propylene carbonate (PC), and ethylene carbonate (EC). One embodiment may further include the step of adding an additive such as an ionic liquid or a reducing agent. Additionally, the method may further include the step of removing the solvent from the mixed solution.

[0079] The above polymer resin, main plasticizer, propylene carbonate, ethylene carbonate, ionic liquid, reducing agent, etc. are the same as those described above.

[0081] The step of preparing a mixture by dissolving the polymer resin in a solvent involves mixing the polymer resin with the solvent and then stirring. The solvent may be a polar organic solvent. This is to facilitate the dissolution of polymer resins such as PVC. The polar organic solvent may be any one of dioxane, tetrahydrofuran (THF), acetone, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and 1-methyl-2-pyrrolidone (NMP). The amount of the solvent may be sufficient to dissolve the polymer resin. This step may be performed at room temperature.

[0083] In the step of adding a plasticizer to the above mixture, the plasticizer is a primary plasticizer, propylene carbonate (PC), and ethylene carbonate (EC). The plasticizers can be mixed in any order, but preferably, the primary plasticizer is added first to increase the plasticization and ion conductivity efficiency of the polymer resin. In this case, the step may include the step of adding the primary plasticizer to the above mixture and the step of adding propylene carbonate and ethylene carbonate to the mixture to which the primary plasticizer has been added.

[0084] In the step of adding a main plasticizer to the above mixture, the content of the main plasticizer may be 700 to 1200 parts by weight, preferably 700 to 1000 parts by weight, and more preferably 700 to 900 parts by weight, per 100 parts by weight of the polymer resin.

[0085] The step of adding propylene carbonate and ethylene carbonate to the mixture to which the main plasticizer is added may involve first mixing and stirring the propylene carbonate and ethylene carbonate, and then adding them to the mixture to which the main plasticizer is added.

[0087] The step of adding a discoloration substance to the mixture may involve directly adding the discoloration substance to the mixture. In another embodiment, the discoloration substance may be dissolved in a solvent to prepare a discoloration substance solution, which is then mixed with the previously prepared mixture. The solvent may vary depending on the discoloration substance as it is capable of dissolving the discoloration substance. In one embodiment, the solvent may be any one of dioxane, tetrahydrofuran (THF), acetone, dimethyl sulfoxide (DMSO), dimethylformamide (DMF), and 1-methyl-2-pyrrolidone (NMP).

[0089] One embodiment may further include a step of adding additives such as ionic liquids or reducing agents. Each step may be performed regardless of the order of the preceding steps and each step. Preferably, it may be performed after the step of mixing a plasticizer.

[0091] The step of removing the solvent from the above mixed solution can be performed by drying the mixture at room temperature or in an oven.

[0093] electrochromic device

[0094] An electrochromic element according to an embodiment of the present invention comprises: a first electrode; a second electrode; and an electrochromic element layer that changes color by a voltage applied by the first electrode and the second electrode; and the electrochromic element layer comprises the composition for an electrochromic element described above.

[0096] The first and second electrodes mentioned above are not particularly limited to those generally used in electrical devices. However, they may be made of ITO glass or ITO-PEN, etc., to provide light transmittance and flexibility.

[0098] The above electrochromic element layer comprises the composition for an electrochromic element described above, and may be manufactured with a suitable size and thickness according to the method for manufacturing an electrochromic member described above.

[0099] In one embodiment, the electrochromic element layer is prepared by drying an electrochromic element composition comprising a polymer resin, a color-changing material, a main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC).

[0100] The above polymer resin, main plasticizer, propylene carbonate, ethylene carbonate, ionic liquid, reducing agent, etc. are the same as those described above.

[0102] Example: Manufacture of an electrochromic member

[0103] Example 1 (D8P0.75E0.25): PVC was from Scientific Polymer Products, Inc., DBA was from TCI, PC was from Daejeong Chemical Co., Ltd., EC was from Daejeong Chemical Co., Ltd., EMIM-TFSI was from io-li-tec, dmFC was from TCI, and THF was used as the solvent from Daejeong Chemical Co., Ltd. First, 0.2216g of PC and 0.0738g of EC were mixed at room temperature. 0.3545g of PVC was dissolved in 25mL of THF at room temperature by stirring, and then 2.8358g of DBA was added and stirred. The previously mixed mixture of PC and EC was added, and 0.4254g of EMIM-TFSI, 20.2483g of DHV[TFSI], and 0.0581g of dmFC were added and stirred at room temperature. The mixture, after stirring was completed, was poured into a Petri dish and dried at room temperature for 24 hours. The prepared electrochromic material was a gel-type film with a thickness of 0.5 mm.

[0105] Example 2 (D8P0.5E0.5): Prepared in the same manner as Example 1, except that 0.1477g of PC and 0.1477g of EC were added.

[0107] Example 3 (D8P0.25E0.75): Prepared in the same manner as Example 1, except that 0.0738g of PC and 0.2216g of EC were added.

[0109] Comparative Example 1 (D9P0E0): 0.3517g of PVC, 3.1653g of DBA, and 0.4220g of EMIM-TFSI were added, and the same as Example 1 was prepared except that PC and EC were not added.

[0111] Comparative Example 2 (D8P1E0): Prepared in the same manner as Example 1, except that 0.2954g of PC was added and no EC was added.

[0113] Experimental Example: Measurement of Ionic Conductivity

[0114] The examples and comparative examples were cut to a size of 10 mm x 10 mm, placed on a Pt-coated electrode, and covered again with a Pt-coated electrode. The gap between the electrodes was 0.3 mm. Using a potentiostat (Biologics, SP240), 10 5 -10 -1 Ionic conductivity was measured under AC conditions of Hz, 10mV. The measured results are shown in Fig. 2.

[0115] Referring to Figure 2, the ionic conductivity was the best in Example 2.

[0117] Experimental Example: Measurement of Transmittance

[0118] Examples and comparative examples were cut to a size of 2 cm X 2 cm, placed on an ITO-PET electrode, and then covered with another ITO-PET electrode to manufacture an electrochromic device.

[0119] A UV-visible spectrophotometer (Perkin Elmer, Lambda 465) and a potentiostat (Biologics, SP240) were used. The electrochromic elements of the examples and comparative examples were set to a 100% baseline, and UV-vis spectra were measured at 607 nm. The measured results are shown in Fig. 3.

[0120] Referring to Figure 3, it can be seen that the change in light transmittance in Example 2 is the fastest, indicating the best discoloration speed.

[0122] Experimental Example: Calculation of Color Efficiency

[0123] The discoloration efficiency was measured using the formula below, and the results are shown in Table 1 and Figure 4.

[0124] [ceremony]

[0125]

[0126] (η is the discoloration efficiency, ΔQ is the charge change, ΔOD is the change in optical density at ΔQ, T bε is the light transmittance in the decolorized state, T c is the light transmittance in the discolored state)

[0127] division Ionic conductivity (mS / cm) T c,max (%) ΔT max (%) t c,90% (s) t b,90% (s) the (cm) 2 / C) Comparative Example 1 0.21436 0.6 99.3 13 25 162.13 Comparative Example 2 0.55477 0.1 99.7 11 21 184.93 Example 1 0.58761 0.5 99.6 10 19 197.9 Example 2 0.65462 0.6 99.4 9 16 209.01 Example 3 0.61484 0.1 99.8 10 20 201.07

[0129] Referring to Table 1 and Figure 4, it can be seen that the discoloration efficiency of Example 2 is the best.

[0131] The present invention is not limited by the embodiments described above and the attached drawings, but is intended to be limited by the appended claims. Accordingly, various substitutions, modifications, and changes may be made by those skilled in the art within the scope of the technical concept of the present invention as described in the claims, without departing from the technical spirit of the invention, and such are also to be considered to fall within the scope of the present invention.

Claims

Claim 1 An electrochromic device composition comprising a polymer resin; a color-changing material; a primary plasticizer; propylene carbonate (PC) and ethylene carbonate (EC), wherein the primary plasticizer is dibutyl adipate (DBA). Claim 2 delete Claim 3 An electrochromic element composition according to claim 1, wherein the propylene carbonate is included in an amount of 2 to 8 weight% with respect to the weight of the main plasticizer, and the ethylene carbonate is included in an amount of 2 to 8 weight% with respect to the weight of the main plasticizer. Claim 4 An electrochromic element composition according to claim 1, wherein the propylene carbonate is included in an amount of 25 to 75 weight% with respect to the weight of the polymer resin, and the ethylene carbonate is included in an amount of 25 to 75 weight% with respect to the weight of the polymer resin. Claim 5 An electrochromic element composition according to claim 1, wherein the weight ratio of propylene carbonate and ethylene carbonate is 3:1 to 1:

3. Claim 6 The electrochromic element composition according to claim 1, wherein the polymer resin comprises at least one of polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), and polyethylene terephthalate (PET). Claim 7 A method for manufacturing an electrochromic material comprising the steps of: dissolving a polymer resin in a solvent to prepare a mixture; adding a plasticizer to the mixture; and adding a color-changing material to the mixture, wherein the plasticizer is a primary plasticizer, propylene carbonate (PC), and ethylene carbonate (EC), and the primary plasticizer is dibutyl adipate (DBA). Claim 8 A method for manufacturing an electrochromic member according to claim 7, wherein the step of adding the plasticizer comprises the step of adding a main plasticizer to the mixture and the step of adding propylene carbonate and ethylene carbonate to the mixture to which the main plasticizer has been added. Claim 9 A method for manufacturing an electrochromic member according to claim 7, wherein, in the step of adding the plasticizer, the weight ratio of the propylene carbonate and the ethylene carbonate is 3:1 to 1:

3. Claim 10 An electrochromic element comprising an electrochromic element layer, wherein the electrochromic element layer is prepared by drying an electrochromic element composition comprising a polymer resin, a color-changing material, a main plasticizer, propylene carbonate (PC), and ethylene carbonate (EC), and wherein the main plasticizer is dibutyl adipate (DBA). Claim 11 An electrochromic element according to claim 10, wherein the weight ratio of the propylene carbonate and ethylene carbonate is 3:1 to 1:3.

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