KR102637324B1 - Electrochromism element composite having improved light- light transmissibility and stretchable, and manufacturing method of electrochromism member - Google Patents

Abstract

The present invention relates to a composition for an electrochromic device and a method of manufacturing an electrochromic member with improved light transparency and elasticity.
A composition for an electrochromic device according to an embodiment of the present invention includes a light-transmitting polymer resin; plasticizer; and electrochromic materials.

Description

Electrochromism element composite having improved light-light transmissibility and stretchable, and manufacturing method of electrochromism member}

The present invention relates to a composition for an electrochromic device and a method of manufacturing an electrochromic member with improved light transparency and elasticity.

An electrochromic device is a device that contains an electrochromic material and changes color by an externally applied voltage. Various materials such as polymer compounds and metal oxides are used as the electrochromic material, and the color changes reversibly depending on the voltage applied to the electrode.

Recently, the field of application of these color-changing devices has been expanding, such as being used in smart window systems that block external views and sunlight, and in automobile glass that displays information such as maps and letters.

Since conventional electrochromic devices use liquid electrochromic materials, there is a problem of electrolyte leakage, and their use as a flexible display is limited. Recently, a solidified water-based electrolyte has been developed, but there is a problem of installing an additional protective layer to prevent water from easily evaporating.

Korean Patent No. 10-2078481

The purpose of the present invention is to provide a composition for an electrochromic device and a method for manufacturing an electrochromic member with improved light transparency and elasticity.

Additionally, it has a long lifespan and excellent durability.

Additionally, its flexibility and elasticity allow it to be applied to various fields.

In addition, the manufacturing method is simple, making it possible to increase production efficiency and reduce manufacturing costs.

A composition for an electrochromic device according to an embodiment of the present invention includes a light-transmitting polymer resin; plasticizer; and electrochromic materials.

The electrochromic material is diheptyl viologen dihexafluorophosphate, and the content of the electrochromic material may be 5 to 20 parts by weight based on 100 parts by weight of the polymer resin.

The electrochromic material can be expressed by Chemical Formula 1 below.

[Formula 1]

It may further include an ionic liquid having a content of 100 to 200 parts by weight based on 100 parts by weight of the polymer resin.

It may further include an anode redox compound in an amount of 1 to 7 parts by weight based on 100 parts by weight of the polymer resin.

An electrochromic device according to an embodiment of the present invention includes a first electrode; second electrode; and an electrochromic device layer that changes color by voltage applied to the first electrode and the second electrode. The electrochromic device layer includes the composition for an electrochromic device described above.

A method of manufacturing an electrochromic member according to an embodiment of the present invention includes the steps of dissolving a polymer resin, a plasticizer, an ionic liquid, and an electrochromic material in a solvent to prepare a mixed solution; and removing the solvent of the mixed solution.

The electrochromic material is Diheptyl viologen dihexafluorophosphate, and the method for producing the color changing material includes preparing a solution of 1,1'-Diheptyl-4,4'-bipyridinium Dibromide in a solvent; And it may include adding NH ₄ PF ₆ to the solution.

In the step of preparing the mixed solution, the content of the plasticizer is 700 to 1200 parts by weight based on 100 parts by weight of the polymer resin, the content of the ionic liquid is 100 to 200 parts by weight, and the content of the electrochromic material is It may be 5 to 20 parts by weight based on 100 parts by weight of the polymer resin.

In the step of preparing the mixed solution, an anode redox compound having a content of 1 to 7 parts by weight based on 100 parts by weight of the polymer resin may be further added.

According to the method for producing a composition for an electrochromic device and an electrochromic member according to an embodiment of the present invention, improved light transmittance and elasticity can be achieved.

Additionally, it has a long lifespan and excellent durability.

Additionally, its flexibility and elasticity allow it to be applied to various fields.

In addition, the manufacturing method is simple, making it possible to increase production efficiency and reduce manufacturing costs.

Figure 1 shows measurement results according to the cyclic voltammetry method.
Figure 2 shows the results of light absorption rate measurement.
Figure 3 is a photograph of the degree of color development according to potential.
Figure 4 shows the results of the light transmittance experiment.
Figure 5 shows the results of optical density versus charge density analysis.
Figure 6 shows the results of the coloring/decolorizing repeated cycle experiment.

Hereinafter, preferred embodiments of the present invention will be described with reference to the attached drawings. However, the embodiments of the present invention may be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Additionally, the embodiments of the present invention are provided to more completely explain the present invention to those with average knowledge in the relevant technical field. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer explanation, and elements indicated by the same symbol in the drawings are the same element. In addition, the same symbols are used throughout the drawings for parts that perform similar functions and actions. In addition, throughout the specification, “including” a certain element means that other elements may be further included, rather than excluding other elements, unless specifically stated to the contrary.

Composition for electrochromic devices

A composition for an electrochromic device according to an embodiment of the present invention includes a light-transmitting polymer resin; plasticizer; and electrochromic materials.

The polymer resin forms the basic body in the composition for electrochromic devices. The polymer resin may have light transparency, flexibility, and elasticity when cured by a plasticizer. For this purpose, the polymer resins include polyvinyl chloride (PVC), polytetrafluoroethylene (PTFE), polyurethane (PU), polymethyl methacrylate (PMMA), polydimethylsiloxane (PDMS), and polyvinyl alcohol (PVA). , polyvinylpyrrolidone (PVP), polyethylene oxide (PEO), polyimide (PI), and polyethylene terephthalate (PET). In particular, by using polyvinyl chloride (PVC), it can have high light transparency, flexibility, and elasticity.

A plasticizer is a substance that plasticizes the polymer resin. The plasticizer is not particularly limited, but may be DBA (Dibutyl Adipate).

The DBA can be expressed by the molecular formula below.

[Molecular formula]

The content of the plasticizer may be 700 to 1200 parts by weight, preferably 800 to 1000 parts by weight, based on 100 parts by weight of the polymer resin. If the content of the plasticizer is too low, crystals are easily formed in the manufactured color change element member, and if the content of the plasticizer is too high, the mechanical properties may decrease.

Electrochromic materials are materials that change color by changing the wavelength they absorb depending on the voltage applied from the outside. In an embodiment of the present invention, the electrochromic material may preferably be diheptyl viologen dihexafluorophosphate. The diheptyl viologen dihexafluorophosphate can be expressed as DHV[PF ₆ ] ₂ and can be expressed in Chemical Formula 1 below. The diheptyl viologen dihexafluorophosphate can produce a blue or cyan color when voltage is applied. By limiting the electrochromic material in this way, the light transmittance of the electrochromic device layer can be maintained high, while the light transmittance can be controlled according to voltage and color can be accurately implemented.

[Formula 1]

The content of the electrochromic material may be 5 to 20 parts by weight, preferably 14 to 17 parts by weight, based on 100 parts by weight of the polymer resin. If the content of the electrochromic material is too low, it may be difficult to control the light transmittance and the color may not be accurately realized, and if the content is too high, crystals are formed in the electrochromic layer, causing uneven discoloration.

In one embodiment, the composition for an electrochromic device may further include an ionic liquid. Ionic liquids are substances that can improve the movement of ions and electrons while generally remaining in a non-volatile liquid state at 100°C. A variety of ionic liquids may be used, but 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfony)imide (EMIM-TFSI) is preferably used. By limiting the ionic liquid in this way, the light transmittance of the electrochromic device layer can be maintained high. The EMIM-TFSI can be expressed by Formula 2 below.

[Formula 2]

The content of the ionic liquid may be 100 to 200 parts by weight, preferably 150 to 170 parts by weight, based on 100 parts by weight of the polymer resin. If the content of the ionic liquid is too high, light transmittance may decrease.

In one embodiment, the composition for an electrochromic device may further include an anode redox compound. The anode redox compound may be either ferrocene or dimethyl ferrocene, preferably dimethyl ferrocene. The dimethyl ferrocene can be expressed in Chemical Formula 3 below.

[Formula 3]

The content of the anode redox compound may be 1 to 5 parts by weight based on 100 parts by weight of the polymer resin.

electrochromic device

An electrochromic device according to an embodiment of the present invention includes a first electrode; second electrode; and an electrochromic device layer that changes color by voltage applied to the first electrode and the second electrode. The electrochromic device layer includes the composition for an electrochromic device described above.

The first electrode and the second electrode are generally used in electric devices and are not particularly limited. However, it may be made of ITO glass or ITO-PEN in order to have light transparency, flexibility and elasticity.

The electrochromic device layer contains the composition for an electrochromic device described above, and may be manufactured by manufacturing the composition for an electrochromic device to an appropriate size and thickness according to the manufacturing method described below.

Manufacturing method of electrochromic material

A method of manufacturing an electrochromic member according to an embodiment of the present invention includes the steps of dissolving a polymer resin, a plasticizer, an ionic liquid, and an electrochromic material in a solvent to prepare a mixed solution; and removing the solvent of the mixed solution.

The polymer resin, plasticizer, and ionic liquid mixed in the step of preparing the mixed solution are the same as described above.

In this step, when the electrochromic material is Diheptyl viologen dihexafluorophosphate, the method for producing the color changing material includes preparing a solution of 1,1'-Diheptyl-4,4'-bipyridinium Dibromide in a solvent; And it may include adding NH ₄ PF ₆ to the solution.

The 1,1'-Diheptyl-4,4'-bipyridinium Dibromide can be expressed as DHV(Br) ₂ .

The solvent is a liquid that can dissolve 1,1'-Diheptyl-4,4'-bipyridinium Dibromide, and is preferably water. In this step, 1,1'-Diheptyl-4,4'-bipyridinium Dibromide can be completely dissolved by adding it to water and stirring.

The step of adding NH ₄ PF ₆ to the solution can be performed by slowly dropping NH ₄ PF ₆ onto the 1,1'-Diheptyl-4,4'-bipyridinium Dibromide solution.

Next, DHV[PF ₆ ] ₂ can be produced by reacting at room temperature. Afterwards, the solvent is removed, washed and dried, and finally DHV[PF ₆ ] ₂ can be prepared.

The content of the plasticizer added in this step is 700 to 1200 parts by weight based on 100 parts by weight of the polymer resin, the content of the ionic liquid is 100 to 200 parts by weight, and the content of the electrochromic material is 100 parts by weight of the polymer resin. It may be 5 to 20 parts by weight. In addition, an anode redox compound having a content of 1 to 5 parts by weight based on 100 parts by weight of the polymer resin may be further added.

After this step, a step of removing the solvent is performed. This step can be performed by leaving the solution mixed with various substances at room temperature for a long period of time, and if necessary, a dryer, etc. can be used. Additionally, this step can be performed on a film or mold to produce the desired shape and thickness.

Manufacturing example: Manufacturing of electrochromic materials

To prepare DHV[PF ₆ ] ₂ , an electrochromic material, 0.2 g of DHV(Br) ₂ from TCI was dissolved in 40 ml of water, and then 0.19 g of NH ₄ PF ₆ was dissolved in another 40 ml of water. Afterwards, the aqueous solution containing NH ₄ PF ₆ was added dropwise to the aqueous solution containing DHV(Br) ₂ . Next, the mixed solution was left at 25°C for 24 hours to generate DHV[PF ₆ ] ₂ . The mixed solution was filtered under reduced pressure, washed with distilled water, and dried at 80°C for 24 hours using a vacuum oven.

To manufacture DBV[PF ₆ ] ₂ , an electrochromic material, 0.2 g of DBV(Br) ₂ (Benzyl viologen dichloride) from Alfa aeser was dissolved in 40 ml of water, and then 0.2389 g of NH ₄ PF ₆ was added one drop at a time. It was added dropwise so that the molar ratio of DBV(Br) ₂ and NH ₄ PF ₆ was 1:3. Next, the mixed solution was left at 25°C for 24 hours to generate DBV[PF ₆ ] ₂ . The mixed solution was filtered under reduced pressure, washed with distilled water, and dried at 80°C for 24 hours using a vacuum oven.

To prepare DEV[PF ₆ ] ₂ , an electrochromic material, 0.2 g of DEV(Br) ₂ (1,1'-diethyl-4, 4'-bipyridinium dibromide) was dissolved in 40 ml of water, and then NH ₄ PF was added thereto. ₆ 0.34g was added drop by drop. Next, the mixed solution was left at 25°C for 24 hours to generate DEV[PF ₆ ] ₂ . The mixed solution was filtered under reduced pressure, washed with distilled water, and dried at 80°C for 24 hours using a vacuum oven.

Manufacturing example: Manufacturing of electrochromic material

Example 1

The polymer resin is 0.3424g of PVC (a product of Schientific Polymer Products), the plasticizer is 3.0816g of DBA (a product of TCI), the ionic liquid is 0.5478g of EMIMTFSI (a product of io-li-tec), and the electrochromic material is DHV[PF _6] . ] ₂ (previously prepared) 0.0333 g and 0.0111 g of dimethyl ferrocene (TCI product) as an anode redox compound were added to THF as a solvent and mixed.

Next, the mixed solution was poured into a glass dish and the solvent was evaporated and dried at room temperature for 3 days.

Example 2

It was prepared in the same manner as Example 1, except that 0.0416 g of DHV[PF ₆ ] ₂ and 0.0138 g of dimethyl ferrocene were used.

Example 3

It was prepared in the same manner as in Example 1, except that 0.0499 g of DHV[PF ₆ ] ₂ and 0.0166 g of dimethyl ferrocene were used.

Example 4

It was prepared in the same manner as in Example 1, except that 0.0583 g of DHV[PF ₆ ] ₂ and 0.0194 g of dimethyl ferrocene were used.

Comparison example 1

It was prepared in the same manner as in Example 1, except that 0.0325 g _of DBV[PF ₆ ] ₂ (prepared previously) was used instead of DHV[PF ₆ ] 2 and 0.0111 g of dimethyl ferrocene was used.

Comparison example 2

It was prepared in the same manner as in Example 2, except that 0.0406 g _{of DBV[PF 6 ] 2 ( prepared} previously) and 0.0138 g of dimethyl ferrocene were used instead of DHV[PF ₆ ] 2.

Comparison example 3

In Example 3, it was prepared in the same manner as Example 1, except that 0.0487 g _{of DBV[PF 6 ] 2 ( prepared} previously) and 0.0166 g of dimethyl ferrocene were used instead of DHV[PF ₆ ] 2.

Comparison example 4

It was prepared in the same manner as in Example 1, except that 0.0130 g _of DEV[PF ₆ ] ₂ (prepared previously) was used instead of DHV[PF ₆ ] 2 and 0.0055 g of dimethyl ferrocene was used.

Comparison example 5

It was prepared in the same manner as Comparative Example 4, except that 0.0196 g of DEV[PF ₆ ] ₂ and 0.008 g of dimethyl ferrocene were used.

Comparison example 6

It was prepared in the same manner as Comparative Example 4, except that 0.0261 g of DEV[PF ₆ ] ₂ and 0.0111 g of dimethyl ferrocene were used.

Manufacturing example: Manufacturing of electrochromic devices

The previously prepared electrochromic member was placed on ITO glass, a 100 μm thick spacer was placed on the edge of the electrochromic member, and the top was covered with another ITO glass. The electrochromic elements manufactured in this way were defined as Examples 5 to 8, respectively, corresponding to Examples 1 to 4 of the electrochromic members, and Comparative Examples 7 to 12, respectively, corresponding to Comparative Examples 1 to 6.

Experiment example: visual inspection

The examples and comparative examples were visually inspected to confirm that there were no abnormalities. In Comparative Examples 3 and 6, it was confirmed that crystals were generated inside.

Experimental example: cyclic voltammetry (cyclic voltammetry) measurement

Current/potential curves were obtained according to cyclic voltammetry for Examples 5 to 8 and Comparative Examples 7 to 11 under 20 mVs ^-1 conditions using a potential generator (biologics, SP240). Figure 1 shows the results of this experiment. Referring to Figure 1, it can be seen that Examples 5 to 8 show a clear change in current compared to the Comparative Example, and in particular, Examples 7 and 8 are more clear.

Experiment example: Measurement of light absorption rate

Example 8, Comparative Example 8, and Comparative Example 11 were measured in the range of 400 to 800 nm using an ultraviolet-visible spectrometer (UV-Vis Spectrometer, Perkin Elmer, Lambda 465). Figure 2(a) shows the experimental results of Example 8, Figure 2(b) shows the experimental results of Comparative Example 8, and Figure 2(c) shows the experimental results of Comparative Example 11. Referring to FIG. 2, it can be seen that Example 8 has the highest absorption rate for a wavelength of 606 nm, and that the light absorption rate is adjusted depending on the applied voltage. In the case of the comparative example, the light absorption rate around 606 nm was higher than that of other wavelengths, but the difference in absorption amount was not large compared to the example.

Experiment example: color expression experiment

A change in color was observed by applying a voltage from 0V to -1.4V to Example 8, Comparative Example 8, and Comparative Example 11. Figure 3 shows the results of this experiment. Referring to FIG. 3, in Example 8, color control according to the applied voltage was most evident and had a darker blue color than the comparative example.

Experiment example: light transmittance experiment

For Examples 5 to 8 and Comparative Examples 7 to 11, the degree to which light with a wavelength of 606 nm was transmitted was measured. At this time, changes in light transmittance were observed while coloring and decolorizing were performed by applying and blocking voltage. Figure 4 shows the results of this experiment. Referring to FIG. 4, the degree of change in light transmittance of the Example was greater than that of the Comparative Example, and even within the Examples, Examples 7 and 8 had a greater degree of change in light transmittance compared to other Examples.

Experimental Example: Optical Density Versus Charge Density Analysis

The optical density versus charge density relationship was analyzed for Examples 5 to 8 and Comparative Examples 7 to 11 under the conditions of 606 nm and -1.0 V, and coloration efficiency (η) was calculated. Figure 8 shows the results of this experiment. Referring to Figure 5, it can be seen that the coloration efficiency (η) of the Example is greater than that of the Comparative Example, and in particular, the increase in coloration efficiency (η) is greater in Examples 6 to 8, and even within the Examples, Examples 7 and 8 are greater. You can.

Experimental example: Light transmittance experiment according to repeated coloring/decolorizing cycles

For Example 8 and Comparative Examples 8 and 11, coloring and decolorization were repeated by repeatedly applying voltage, and the degree to which light with a wavelength of 606 nm was transmitted was measured for 40,000 seconds. At this time, changes in light transmittance were observed while coloring and decolorizing were performed by applying and blocking voltage. Figure 6 shows the results of this experiment, (a) is the result of Example 8, (b) is the result of Comparative Example 8, and (c) is the result of Comparative Example 11. Referring to FIG. 6, it can be seen that the light transmittance of Example 8 was maintained constant during the cycle period, but the light transmittance of Comparative Examples 8 and 11 decreased.

The present invention is not limited by the above-described embodiments and attached drawings, but is intended to be limited by the attached claims. Accordingly, various forms of substitution, modification, and change may be made by those skilled in the art without departing from the technical spirit of the present invention as set forth in the claims, and this also falls within the scope of the present invention. something to do.

Claims (10)

Light-transmissive polymer resin;
plasticizer;
ionic liquid; and
Contains electrochromic substances;
The light-transmitting polymer resin is Polyvinyl Chloride (PVC),
The electrochromic material is Diheptyl viologen dihexafluorophosphate, and is expressed in Chemical Formula 1 below,
[Formula 1]

The content of the electrochromic material is 14 to 17 parts by weight based on 100 parts by weight of the polymer resin,
The ionic liquid is 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfony)imide (EMIM-TFSI) and is expressed in Formula 2 below,
[Formula 2]

Composition for electrochromic devices. delete delete According to paragraph 1,
The content of the ionic liquid is 100 to 200 parts by weight based on 100 parts by weight of the polymer resin,
Composition for electrochromic devices. According to paragraph 1,
Further comprising an anode redox compound having a content of 1 to 7 parts by weight based on 100 parts by weight of the polymer resin,
Composition for electrochromic devices.
first electrode;
second electrode; and
It includes an electrochromic element layer that changes color depending on the voltage applied by the first electrode and the second electrode,
The electrochromic device layer includes the electrochromic device composition of claim 1,
Electrochromic device.
Preparing a mixed solution by dissolving a light-transmissive polymer resin, a plasticizer, an ionic liquid, and an electrochromic material in a solvent; and
It includes the step of removing the solvent of the mixed solution,
The light-transmitting polymer resin is Polyvinyl Chloride (PVC),
The electrochromic material is Diheptyl viologen dihexafluorophosphate, and is expressed in Chemical Formula 1 below,
[Formula 1]

The content of the electrochromic material is 14 to 17 parts by weight based on 100 parts by weight of the polymer resin,
The ionic liquid is 1-Ethyl-3-methylimidazolium bis(trifluoromethanesulfony)imide (EMIM-TFSI) and is expressed in Formula 2 below,
[Formula 2]

Manufacturing method of electrochromic material. In clause 7,
A method of manufacturing an electrochromic member wherein the electrochromic material is manufactured by the manufacturing method below.
Preparing a solution of 1,1'-Diheptyl-4,4'-bipyridinium Dibromide in a solvent; and
Adding NH ₄ PF ₆ to the solution. In clause 7,
In the step of preparing the mixed solution,
The content of the plasticizer is 700 to 1200 parts by weight based on 100 parts by weight of the polymer resin,
The content of the ionic liquid is 100 to 200 parts by weight,
Manufacturing method of electrochromic material. In clause 7,
In the step of preparing the mixed solution,
Further adding an anode redox compound in an amount of 1 to 7 parts by weight based on 100 parts by weight of the polymer resin,
Manufacturing method of electrochromic material.