Method for manufacturing a stretchable electrochromic device and a stretchable electrochromic device manufactured thereby

Abstract

The present invention relates to a method for manufacturing a stretchable color-changing element and a stretchable color-changing element manufactured thereby. More specifically, the stretchable color-changing element is manufactured by stretching a color-changing polymer gel and then coating one and / or the other side of the gel with a metal solution. The stretchable color-changing element has excellent water resistance and initial transmittance.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a stretchable electrochromic device and a stretchable electrochromic device manufactured thereby. More specifically, the stretchable electrochromic device manufactured by stretching a color-changing polymer gel and then coating a metal solution on one surface and / or the other surface thereof is characterized by having excellent water resistance and an initial transmittance.

Background Art

[0002] Electrochromism is a phenomenon in which the hue reversibly changes depending on the electric field direction when a voltage is applied. A substance whose optical properties reversibly change by an electrochemical oxidation-reduction reaction having such characteristics is called an electrochromic substance. Such an electrochromic substance does not have a color unless an electrical signal is applied from the outside, and when an electrical signal is applied, it becomes colored, or conversely, it has a color when no signal is applied from the outside, and the color disappears when a signal is applied.

[0003] An electrochromic device is a device whose light transmission characteristics change when the color of an electrochromic substance changes by an electrochemical oxidation-reduction reaction due to the application of a voltage. Currently, the demand for electrochromic devices that selectively transmit light in various technical fields is increasing. Such electrochromic devices are applied in various fields such as smart windows, smart mirrors, display devices, and camouflage devices.

[0004] Therefore, various technologies related to electrochromic devices have been developed. For example, Patent Document 1 (Applicant: LG Electronics Inc.) relates to an electrochromic element with improved discoloration speed. The present invention provides an electrochromic element including a first transparent electrode, a second transparent electrode facing the first transparent electrode, a first bus electrode of a predetermined pattern formed on the upper surface of the first transparent electrode, an electrolyte layer positioned between the first bus electrode and the second transparent electrode, a first electrochromic layer positioned between the first transparent electrode and the electrolyte layer and in contact with the electrolyte layer, and a passivation layer formed between the first bus electrode and the electrochromic layer to prevent contact between the first bus electrode and the electrochromic layer and surrounding the first bus electrode.

[0005] However, an electrochromic device (element) or a discoloration element using a polymer gel generally has reduced stability against water, and thus research to overcome this has been continuously conducted.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] The present invention provides a method for manufacturing a stretchable electrochromic element with excellent stability against water.

[0008] The present invention also provides a stretchable electrochromic element manufactured by the method for manufacturing the stretchable electrochromic element.

[0009] The present invention also provides a product including the stretchable electrochromic element.

Means for Solving the Problems

[0010] As a technical means for achieving the above-described technical problems, one aspect of the present invention is a method for manufacturing a stretchable discoloration element, comprising a step of stretching a polymer gel, a step of coating a metal solution on one surface of the stretched polymer gel, and a step of restoring the stretched polymer gel.

[0011] The polymer gel includes a polymer resin, a plasticizer, an ionic liquid, a discoloring substance, and a reducing agent.

[0012] The polymer resin includes a polymer resin selected from the group consisting of polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), polyethylene terephthalate (PET), and combinations thereof.

[0013] The ionic liquid includes an ionic liquid selected from the group consisting of a neutral liquid, an anionic liquid, a cationic liquid, and combinations thereof.

[0014] The neutral liquid includes a neutral liquid selected from the group consisting of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Emim TFSI), 1-methyl-3-propylimidazolium iodide (MPII), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIHSO4), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide (PYRTFSI), and combinations thereof.

[0015] The anionic liquid is trifluoroacetic acid ([tfa] - ), trifluoromethanesulfonate ([CF3SO3] - ), bis(fluorosulfonyl)imide ([N(SO2F)2] - ), bis(trifluoromethanesulfonyl)imide ([N(SO2CF3)2] - ), dicyanamide ([N(CN)2] - ), tetracyanoborate ([B(CN)4] - ), dihydrogen phosphate ([H2PO4] - ), hydrogen sulfate ([HSO4] - ), or an anionic liquid selected from the group consisting of combinations thereof.

[0016] The cationic liquid includes a cationic liquid selected from the group consisting of imidazolium, pyrrolidinium, piperidinium alkylmethylimidazolium, and combinations thereof.

[0017] Based on 100 parts by weight of the polymer resin, the content of the ionic liquid is 40 to 140 parts by weight, the content of the plasticizer is 300 to 1,500 parts by weight, and the contents of the discoloring substance and the reducing agent are each 10 to 140 parts by weight.

[0018] The stretching of the polymer gel is carried out by stretching it by 20% to 80% with respect to the length of the polymer gel.

[0019] The metal solution includes a solution of a metal selected from the group consisting of silver (Ag), gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), ruthenium (Ru), osmium (Os), and combinations thereof.

[0020] The concentration of the metal solution is 1 mg / mL to 20 mg / mL.

[0021] The manufacturing method of the stretchable variable color element further includes a step of coating a metal solution on one surface of the stretched polymer gel, and then a step of annealing by spraying water on one surface of the gel coated with the metal solution.

[0022] The annealing is performed for 10 seconds to 1 minute.

[0023] The recovery of the polymer gel is performed at a speed of 0.01 mm / s to 5.0 mm / s.

[0024] The manufacturing method of the stretchable variable color element further includes a step of recovering the stretched polymer gel, and then a step of further performing the same process on the other surface of the polymer gel.

[0025] Another aspect of the present invention provides a stretchable variable color element manufactured by the manufacturing method of the stretchable variable color element, and a product including the stretchable variable color element.

Advantages of the Invention

[0026] The stretchable variable color element manufactured by the manufacturing method of the stretchable variable color element according to the present invention as described above is manufactured by coating a metal solution on one surface and / or the other surface after stretching a color-changing polymer gel, so it has excellent stability in water.

[0027] In addition, the stretchable variable color element has excellent initial transmittance and has stability in any deformation, so the performance as a variable color element is maintained.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

BEST MODE FOR CARRYING OUT THE INVENTION

[0029] Hereinafter, the present invention will be described in more detail. However, the present invention may be embodied in various different forms, and the present invention is not limited by the embodiments described herein, and the present invention is only defined by the claims described later.

[0030] In addition, the terms used in the present invention are only used to describe specific embodiments and are not intended to limit the present invention. A singular expression includes plural expressions unless the context clearly indicates otherwise. Throughout the specification of the present invention, saying that a component "includes" means including other components rather than excluding other components, unless otherwise stated to the contrary.

[0031] The first aspect of the present application provides a method for manufacturing a stretchable variable color device, including the steps of stretching a polymer gel, coating a metal solution on one surface of the stretched polymer gel, and recovering the stretched polymer gel.

[0032] Hereinafter, the method for manufacturing a stretchable variable color device according to the first aspect of the present application will be described in detail step by step with reference to FIGS. 1 and 2. At this time, FIG. 1 is a sequence diagram showing the method for manufacturing a stretchable variable color device according to an embodiment of the present invention, and FIG. 2 is a schematic diagram showing the method for manufacturing a stretchable variable color device according to the present invention.

[0033] On the one hand, since the configurations shown in FIGS. 1 and 2 respectively are only one embodiment, any deformation of some forms or replacement of components should be understood to be included within the scope that does not harm the scope of rights of the present invention. First, in one embodiment of the present invention, the manufacturing method of the stretchable discoloring element includes a step S10 of stretching a polymer gel.

[0034] In one embodiment of the present application, the stretching of the polymer gel is to stretch by 20% to 80% with respect to the length of the polymer gel, but according to one embodiment of the present invention, it is stretched by 50%. At this time, the degree of stretching is to stretch by the corresponding percentage (%) with respect to the original length of the polymer gel. For example, when the length of the polymer gel is 5 cm and it is stretched by 50%, the length of the stretched polymer gel is 7.5 cm. On the other hand, the stretching of the polymer gel is to stretch by applying a certain force in the length direction, and both ends are fixed to maintain the length of the stretched polymer gel.

[0035] In one embodiment of the present application, the polymer gel includes a polymer resin, a plasticizer, an ionic liquid, a discoloring substance, and a reducing agent.

[0036] In one embodiment of the present application, the polymer resin is plasticized without a solvent, and includes a polymer resin selected from the group consisting of polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), polyethylene terephthalate (PET), and combinations thereof.

[0037] In one embodiment of the present application, the plasticizer is a substance that plasticizes the polymer resin at a certain temperature and has a flash point of 200 °C or higher. On the other hand, according to one embodiment of the present invention, the plasticizer is dibutyl adipate (DBA), and the dibutyl adipate is represented by the following Chemical Formula 1.

[0038]

Chemical formula

[0039] In one embodiment of the present application, the ionic liquid means a liquid containing ions, and includes, for example, a neutral liquid, an anionic liquid, or a cationic liquid.

[0040] In one embodiment of the present application, the neutral liquid includes a neutral liquid selected from the group consisting of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Emim TFSI), 1-methyl-3-propylimidazolium iodide (MPII), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIHSO4), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), N-methyl-N-butylpyrrolidinium bis(trifluoromethylsulfonyl)imide (PYRTFSI), and combinations thereof.

[0041] In one embodiment of the present application, the anionic liquid is trifluoroacetic acid ([tfa] - ), trifluoromethanesulfonate ([CF3SO3] - ), bis(fluorosulfonyl)imide ([N(SO2F)2] - ), bis(trifluoromethylsulfonyl)imide ([N(SO2CF3)2] - ), dicyanamide ([N(CN)2] - ), tetracyanoborate ([B(CN)4] -) and dihydrogen phosphate ([H2PO4] - ) and hydrogen sulfate ([HSO4] - ) and an anionic liquid selected from the group consisting of combinations thereof.

[0042] In one embodiment of the present application, the cationic liquid includes a cationic liquid selected from the group consisting of imidazolium, pyrrolidinium, piperidinium alkylmethylimidazolium, and combinations thereof.

[0043] On the other hand, according to one embodiment of the present invention, the ionic liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Emim TFSI), which is represented by the following Chemical Formula 2.

[0044]

Chemical formula

[0045] In one embodiment of the present application, the discoloring substance is a substance used for discoloration of the polymer gel. According to one embodiment of the present invention, DHV[TFSI]2 is used, but it is not limited thereto. On the other hand, the DHV[TFSI]2 is represented by the following Chemical Formula 3.

[0046]

Chemical formula

[0047] In one embodiment of the present application, the reducing agent is a substance that reduces the target substance. According to one embodiment of the present invention, dimethylferrocene is used, but it is not limited thereto. On the other hand, the dimethylferrocene is represented by the following Chemical Formula 4.

[0048]

Chemical formula

[0049] In an embodiment of the present application, based on 100 parts by weight of the polymer resin, the content of the ionic liquid is 40 to 140 parts by weight, the content of the plasticizer is 300 to 1,500 parts by weight, and the contents of the discoloring substance and the reducing agent are each 10 to 140 parts by weight. Preferably, the content of the ionic liquid is 100 to 140 parts by weight, the content of the plasticizer is 800 to 1,000 parts by weight, and the contents of the discoloring substance and the reducing agent are each 10 to 120 parts by weight. On the other hand, according to an embodiment of the present invention, the weight content ratios of the polymer resin, plasticizer, ionic liquid, discoloring substance, and reducing agent are 1:9:1.2:0.7061:0.1652. If the content of the constituent substances deviates from the above range, there may be a problem that the ionic conductivity, discoloration rate, and decoloration rate of the polymer gel decrease.

[0050] Next, in an embodiment of the present application, the manufacturing method of the stretchable discoloring element includes step S20 of coating a metal solution on one surface of the stretched polymer gel.

[0051] In an embodiment of the present application, the coating can be used without limitation as long as it is a general coating method. For example, the metal solution is sprayed and coated in a spray method.

[0052] According to an embodiment of the present application, the metal solution includes a solution of a metal selected from the group consisting of silver (Ag), gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), ruthenium (Ru), osmium (Os), and combinations thereof. Preferably, a silver (Ag) nanowire solution is used. At this time, when using the silver (Ag) nanowire solution, polymers such as polyvinylpyrrolidone (PVP) are used in the manufacturing process, and the size of the silver nanowires is an average diameter of 30 nm and an average length of 20 μm. On the other hand, the metal solution means a solution in which the metal is dissolved in a solvent. Ethanol, water, isopropyl alcohol, etc. are used as the solvent, but it is not limited thereto. According to an embodiment of the present invention, ethanol is used. On the other hand, the concentration of the metal solution is 1 mg / mL to 20 mg / mL, preferably 1 mg / mL to 10 mg / mL, and according to an embodiment of the present invention, it is about 5 mg / mL. If the concentration of the metal solution is less than 1 mg / mL, the content of the metal contained is relatively too small, and the performance as a variable color device may be reduced. If it exceeds 20 mg / mL, the content of the metal contained is relatively too large, and there may be a problem of reduced dispersion stability.

[0053] Next, in an embodiment of the present application, the method for manufacturing the stretchable variable color device includes a step of spraying water onto one surface of a polymer gel coated with the metal solution and annealing.

[0054] In an embodiment of the present application, the spraying and annealing of the water are performed simultaneously. Also, the annealing is performed for 10 seconds to 1 minute, preferably 20 seconds to 40 seconds, and according to an embodiment of the present invention, it is performed for about 30 seconds. If the annealing is performed for less than 10 seconds, the time is too short and the annealing may not be sufficiently performed. If it is performed for more than 1 minute, there may be a problem that the coated metal desorbs.

[0055] Next, in an embodiment of the present application, the method for manufacturing the stretchable variable color device includes a step S30 of recovering the stretched polymer gel.

[0056] In an embodiment of the present application, the step of restoring is a step of simultaneously performing the annealing process and further restoring the length of the stretched polymer gel to its original length.

[0057] In an embodiment of the present application, the restoration of the polymer gel is performed at a speed of 0.01 mm / s to 5.0 mm / s, but is not limited thereto, and may be appropriately changed depending on the original length of the polymer gel.

[0058] Next, in an embodiment of the present application, the method for manufacturing the stretchable variable color element includes a step of further performing the same steps (S10 to S30) on the other surface of the polymer gel.

[0059] In an embodiment of the present application, in the method for manufacturing the stretchable variable color element described above, the metal solution is coated only on one surface of the polymer gel, but the metal solution may also be coated on the other surface.

[0060] More specifically, it further includes a step of restoring the stretched polymer gel, and then a step of further stretching the restored polymer gel, a step of coating a metal solution on the other surface of the stretched polymer gel, and a step of restoring the stretched polymer gel. Therefore, as shown in FIG. 2, the stretchable variable color element has a form in which the metal solution is coated on both surfaces of the polymer gel.

[0061] The second aspect of the present application provides a stretchable variable color element manufactured by the method for manufacturing a stretchable variable color element according to the first aspect of the present application, and a product including the stretchable variable color element.

[0062] Although detailed description of the parts overlapping with the first aspect of the present application is omitted, the content described for the first aspect of the present application is equally applicable even if the description is omitted in the second aspect.

[0063] Hereinafter, the stretchable variable color element according to the second aspect of the present application and the product including the same will be described in detail.

[0064] In one embodiment of the present application, the stretchable discoloration element is manufactured by stretching a discolorable polymer gel and then coating a metal solution on one surface and / or the other surface thereof, so that it has excellent stability against water. In addition, the stretchable discoloration element has excellent initial transmittance and has stability against any deformation, so that the performance as a discoloration element is smoothly maintained.

[0065] In one embodiment of the present application, the product containing the stretchable discoloration element is applied without limitation as long as it is a product that requires a stretchable discoloration element. For example, it is applied to architectural window glass, smart windows, vehicle mirrors, displays, or electronic shelf labels (ESL).

[0066] Hereinafter, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. However, the present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0067] Example. Manufacture of Stretchable Discoloration Element by Stretching 1. Manufacture of PVC Discoloration Gel Polyvinyl chloride (PVC) was added to tetrahydrofuran (THF) stirred at 400 rpm with a magnetic bar and dissolved. 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSI] which is an ionic liquid, DHV[TFSI]2 which is a discoloring substance, and dimethylferrocene which is a reducing agent were added to the solution, and finally dibutyl adipate (DBA) which is a plasticizer was added and stirred well for 12 hours. At this time, the weight mixing ratio of the PVC, DBA, [EMIM][TFSI], DHV[TFSI]2, and dimethylferrocene was 1:9:1.2:0.7061:0.1652. Next, the solution was poured into a Petri dish and dried at room temperature for 48 hours to manufacture a PVC discoloration gel.

[0068] 2. Manufacture of Stretchable Discoloration Element As shown in Fig. 2, a stretchable discoloration element was manufactured. Specifically, after cutting the PVC discoloration gel manufactured in the above 1. into a size of 5 cm × 6 cm, it was fabricated to a thickness of 0.5 mm and stretched by 50% with respect to its original length.

[0069] Next, a silver nanowire solution (concentration: 5 mg / mL) mixed with ethanol was put into an air spray and sprayed onto one surface of the stretched PVC discoloration gel to coat the silver nanowires (height: 15 cm / spray pressure: 1 psi).

[0070] Next, after drying the coated solution, water was sprayed onto the coated surface and annealed for 30 minutes, and at the same time, the length of the stretched PVC gel was restored at a speed of 0.5 mm / s.

[0071] Finally, a stretchable discoloration element was manufactured by coating silver nanowires on the opposite surface of the PVC gel coated with the silver nanowires by the same process.

[0072] Experimental Example 1. Evaluation of Resistance to Water To evaluate the resistance of the stretchable discoloration element manufactured according to the above example to water, the discoloration element was immersed in water, and the volume change caused thereby was measured and shown in Fig. 3, and the transmittance over time was measured and shown in Fig. 4.

[0073] As shown in Fig. 3, it was confirmed that the stretchable discoloration element manufactured according to the example of the present invention has no volume change even when immersed in water for about one day.

[0074] Also, as shown in Fig. 4, it was confirmed that the stretchable discoloration element manufactured according to the example of the present invention has almost no change in transmittance over time before and after immersion in water.

[0075] This was analyzed to be because the stretchable discoloration element according to the present invention is made of a non-aqueous base material.

[0076] Experimental Example 2. Evaluation of the Optical Performance of the Stretchable Variable Color Element The transmittance of the stretchable variable color element manufactured in the above example before and after stretching was measured and shown in FIG. 5 according to time.

[0077] As shown in FIG. 5, it was confirmed that the initial transmittance increased when the stretchable variable color element was stretched.

[0078] Also, the optical density according to the charge density of the stretchable variable color element manufactured in the above example before and after stretching was measured and shown in FIG. 6.

[0079] As shown in FIG. 6, it was confirmed that when the stretchable variable color element was stretched, the amount of color change, the color change speed, and the discoloration speed decreased. This was analyzed to be due to an increase in the resistance of the electrode.

[0080] Experimental Example 3. Evaluation of the Stability of the Stretchable Variable Color Element The stability of the stretchable variable color element manufactured in the above example when deformed in various ways was evaluated, and the results are shown in FIG. 7.

[0081] As shown in FIG. 7, it was confirmed that the stretchable variable color element manufactured according to the example of the present invention was stable even when deformed in various ways, and it was also confirmed that the performance as a variable color element was maintained.

[0082] As described above, the present invention has been described in detail with reference to the drawings and preferred embodiments. However, the scope of the technical idea of the present invention is not limited by such drawings and embodiments. Therefore, there are various modified examples or equivalent range embodiments within the scope of the technical idea of the present invention. Therefore, the scope of the rights of the technical idea according to the present invention should be interpreted by the scope of the claims, and the technical ideas within the equivalent or equivalent range should be interpreted as belonging to the scope of the rights of the present invention.

[0083] This patent is the result of the application of "Next-generation transparent stretchable sensors and electrochemical display devices using non-aqueous, high-performance, multifunctional ion-conductive and non-ion-conductive polymer gels" by the National Research Foundation of Korea (NRF-2021R1A2C201198).

Claims

1. A step of stretching a polymer gel; A step of coating a metal solution on one surface of the stretched polymer gel; A step of recovering the stretched polymer gel; comprising The polymer gel contains a polymer resin, a plasticizer, an ionic liquid, a discoloring substance, and a reducing agent, and is a method for manufacturing a stretchable discoloring element.

2. The method for manufacturing a stretchable discoloring element according to claim 1, wherein the polymer resin includes a polymer resin selected from the group consisting of polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), polyethylene terephthalate (PET), and combinations thereof.

3. The method for manufacturing a stretchable discoloring element according to claim 1, wherein the ionic liquid includes an ionic liquid selected from the group consisting of a neutral liquid, an anionic liquid, a cationic liquid, and combinations thereof.

4. The neutral liquid is 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (Emim TFSI) and 1-methyl-3-propylimidazolium iodide (MPII), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF ４ ) and 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMITf), 1-ethyl-3-methylimidazolium hydrogen sulfate (EMIHSO ４ ) and N-methyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide (PYRTFSI), and a method for producing a stretchable discoloring element according to claim 3, comprising a neutral liquid selected from the group consisting of combinations thereof.

5. The anionic liquid is trifluoroacetic acid ([tfa] － ), trifluoromethanesulfonate ([CF ３ SO ３ ] － ) and bis(fluorosulfonyl)imide ([N(SO ２ F) ２ ] － ) and bis(trifluoromethanesulfonyl)imide ([N(SO ２ CF ３ ) ２ ] － ) and dicyanamide ([N(CN) ２ ] － ) and tetracyanoborate ([B(CN) ４ ] － ) and dihydrogen phosphate ([H ２ P.O. ４ ] － ) and hydrogen sulfate ([HSO ４ ] － 4. The method for producing the stretchable color-changing element according to claim 3, comprising an anionic liquid selected from the group consisting of:

6. The method for manufacturing a stretchable discoloring element according to claim 3, wherein the cationic liquid includes a cationic liquid selected from the group consisting of imidazolium, pyrrolidinium, piperidinium alkylmethylimidazolium, and combinations thereof.

7. Based on 100 parts by weight of the polymer resin, the content of the ionic liquid is 40 to 140 parts by weight, the content of the plasticizer is 300 to 1,500 parts by weight, and the content of the discoloring substance and the reducing agent is 10 to 140 parts by weight each, and is a method for manufacturing a stretchable discoloring element according to claim 1.

8. The method for manufacturing a stretchable discoloring element according to claim 1, wherein the stretching of the polymer gel is performed by stretching it by 20% to 80% with respect to the length of the polymer gel.

9. The method for manufacturing a stretchable discoloring element according to claim 1, wherein the metal solution includes a solution of a metal selected from the group consisting of silver (Ag), gold (Au), platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), ruthenium (Ru), osmium (Os), and combinations thereof.

10. The method for manufacturing a stretchable discoloring element according to claim 1, wherein the concentration of the metal solution is 1 mg / mL to 20 mg / mL.

11. The manufacturing method of the stretchable variable color element is as follows: Coating a metal solution on one surface of the stretched polymer gel, and then Spraying water on one surface of the gel coated with the metal solution and annealing it, The manufacturing method of the stretchable variable color element according to claim 1, further comprising the above steps.

12. The manufacturing method of the stretchable variable color element according to claim 11, wherein the annealing is performed for 10 seconds to 1 minute.

13. The manufacturing method of the stretchable variable color element according to claim 1, wherein the recovery of the polymer gel is performed at a speed of 0.01 mm / s to 5.0 mm / s.

14. The manufacturing method of the stretchable variable color element is as follows: Recovering the stretched polymer gel, and then Performing the same process on the other surface of the polymer gel, The manufacturing method of the stretchable variable color element according to claim 1, further comprising the above steps.

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