JP2000214493A - Electrochromic device and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochromic(EC) device in which a sealing agent is hardly peeled and the leaking of an electrolyte can be prevented, and to provide a method for the production of the device. SOLUTION: In this device, an electrolyte layer 5 and an electrochromic(EC) layer 4 are sealed with a sealing agent applied between a first transparent substrate 1 or a first transparent electrode layer 2 and a second transparent substrate 7 or a second transparent electrode 6. Thereby, the end face of the EC layer 4 is not exposed to air so that the water content in the air does not intrude into the EC layer through the end face of the EC layer 4. Thereby, the adhesion property of the sealing agent is well maintained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly reliable electrochromic (EC) device having a small amount of electrolyte leakage and a method of manufacturing the same.

[0002]

2. Description of the Related Art As an EC element, a first transparent electrode layer 22 and a sealant 23 are formed on a first transparent substrate 21 as shown in FIG.
A transmission-type EC in which an electrolyte layer 24, an EC layer 25, a second transparent electrode layer 26, and a second transparent substrate 27 encapsulated therein are laminated.
Devices are known. Further, as shown in FIG. 6 or FIG. 7, a reflection type EC element in which a reflection film 28 is formed outside the first transparent substrate 21 or the second transparent substrate 27 is also known.

[0003] These EC elements are composed of a first transparent electrode layer 22.
By applying a predetermined voltage between the first transparent electrode layer 26 and the second transparent electrode layer 26, an oxidation / reduction reaction occurs in the solute of the EC layer 25,
As a result, a reversible change of charge and discharge can be obtained.

[0004]

However, the above conventional E
In the C element, a sealant 23 is provided between the first transparent electrode layer 22 or the second transparent electrode layer 26 and the EC layer 25, and only the electrolyte layer 24 is sealed by the sealant 23. The end face of the EC layer 25 is exposed to the outside air, and the moisture in the outside air penetrates into the EC layer 25 through the end face, and the adhesion of the sealant 23 to the EC layer 25 is easily impaired. In particular, according to the test results of the inventors, E
This tendency is remarkable when the C layer 25 is a porous solid such as WO ₃ .nNb ₂ O ₅ (where n is zero or a positive number).

For this reason, in this kind of EC device,
In particular, under the conditions of high temperature and high humidity, the sealing agent 23 is easily peeled off, which tends to cause a problem that the electrolyte of the electrolyte layer 24 leaks. The present invention has been made in view of the above-mentioned conventional circumstances, and an object of the present invention is to provide an EC element which can prevent a sealant from peeling easily and prevent electrolyte leakage, and a method for manufacturing the same.

[0006]

An EC device according to the present invention comprises a first substrate, a first electrode layer formed on the first substrate, and a second substrate provided to face the first substrate. And a second electrode layer provided on the second substrate so as to face the first electrode layer;
In an EC device having an electrolyte layer and an EC layer interposed between the first electrode layer and the second electrode layer, the electrolyte layer and the EC layer may be formed on the first substrate or the first electrode layer. It is characterized by being sealed by a sealant interposed between the second substrate and the second electrode layer.

[0007] In the EC device of the present invention, between the first substrate and the second substrate, between the first substrate and the second electrode layer, between the first electrode layer and the second substrate, or between the first electrode layer and the second electrode layer. A sealant is interposed between the first electrode layer and the second electrode layer, and seals the electrolyte layer and the EC layer with the sealant. For this reason, the end face of the EC layer is not exposed to the outside air, and moisture in the outside air does not enter the EC layer through the end face of the EC layer. For this reason, the adhesiveness of the sealant is suitably maintained.

Therefore, in the EC device of the present invention, the sealant is hardly peeled off, especially under high temperature and high humidity conditions, thereby preventing leakage of the electrolyte from the electrolyte layer. A glass plate or a resin plate can be used as the first and second substrates. Either one of the first and second substrates needs to be transparent. First and second electrode layers, in particular a transparent first,
As the two electrode layers, ITO (indium tin oxide (In ₂ O ₃ .SnO ₂ )) or fluorine-doped SnO ₂
A film or the like can be employed.

As the EC layer, a layer containing tungsten oxide, molybdenum oxide, vanadium oxide, niobium oxide, titanium oxide, or the like can be used. The above effects are particularly remarkable when the EC layer is a porous solid such as WO ₃ .nNb ₂ O ₅ (where n is zero or a positive number). The electrolyte layer includes a cation source for coloring the EC layer,
The effect of the present invention is great when it is composed of a redox agent for reversibly oxidizing and reducing the C layer, an organic solvent for dissolving the cation source and the redox agent, and water. Li salts such as lithium perchlorate, Na salts,
A supporting salt such as K salt can be employed. By adding a redox agent, the redox agent can cause a reduction / oxidation reaction (compensate for electric charge) while the EC layer is undergoing an oxidation / reduction reaction so that the reversible reaction can be continued semipermanently. And the cycle life is improved. It is preferable to use a ferrocene compound as the redox agent. The redox agent is preferably added to the electrolyte at a concentration of about 0.1M. As an organic solvent, γ-
Butyrolactone, sulfolane, a mixture thereof or propylene carbonate can be employed.

As the sealant, an epoxy resin, a silicone resin, a fluorine resin, an acrylic resin, a urethane resin, or the like, or a mixture thereof can be used. In the case where the EC element is a reflective EC element, an evaporated film of Al or the like can be used as the reflective film. EC of the present invention
The device can be manufactured by the following method for manufacturing an EC device of the present invention. This manufacturing method is a method for manufacturing an EC device including a first substrate, a first electrode layer, an electrolyte layer, an EC layer, a second electrode layer, and a second substrate. A first electrode substrate on which a first electrode layer is formed;
A preparation step of preparing a second electrode substrate having the second electrode layer formed on the substrate, and applying a liquid composition to be the EC layer by solidification on the first electrode layer of the first electrode substrate A coating step of solidifying a necessary portion of the composition to form the EC layer, a removing step of removing the composition other than the EC layer, and a sealing agent surrounding the EC layer by the first step. Forming a sealant on the first substrate or the first electrode layer of the electrode substrate, and bonding the second electrode substrate on the sealant such that the EC layer side becomes the second electrode layer; Process and the EC
A sealing step of sealing the electrolyte layer between the layer and the second electrode layer.

In the manufacturing method of the present invention, first, in a preparation step, first and second electrode layers are formed on the first and second substrates to form first and second electrode substrates. Next, in a coating step, a liquid composition that becomes an EC layer by solidification is coated on the first electrode layer of the first electrode substrate. As this composition, one in which a peroxide of a transition metal is dissolved can be employed. More specifically, WO ₃ .nNb ₂ O ₅ (where n
, A polymolybdic peroxide solution, a polyvanadate solution, a polyniobate peroxide solution, a polytitanic peroxide solution, etc., in addition to a polytungstic acid solution containing zero or a positive number. . Application methods include dip coating, spin coating,
A spray coating method or the like can be employed.

Then, in a solidifying step, a necessary portion of the applied composition is solidified to form an EC layer. As a solidification method, a method of irradiating a necessary portion with ultraviolet rays, a method of heating a necessary portion, or the like can be employed. In the removing step, the composition that did not become the EC layer in the solidifying step is removed. In the case where the composition is a polytungsten peroxide solution containing WO ₃ · aNb ₂ O ₅ (where a is zero or a positive number) as a solute, dissolution of the composition with water or an organic solvent is employed as the removing step. can do.

Next, in a sealant forming step, a sealant is formed on the first substrate or the first electrode layer of the first electrode substrate so as to surround the EC layer. Then, in the joining step, the first electrode substrate and the second electrode substrate are joined. At this time, the first
The second electrode layer is made to face the EC layer on the electrode substrate, and a gap for forming an electrolyte layer is left between the EC layer and the second electrode layer.

Thereafter, in the encapsulation step, the EC layer and the second
An electrolyte is sealed in a gap between the electrode layer and the electrode layer to form an electrolyte layer. As described above, it is possible to easily manufacture an EC element with less leakage of the electrolyte. Further, a reflection type EC element can be similarly manufactured by forming a reflection film on the first and second substrates on the side opposite to the first and second electrode layers.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments 1 to 3 embodying the present invention will be described together with comparative examples 1 and 2 with reference to the drawings.

[0016]

Embodiment 1 As shown in FIGS. 1 and 2, the EC element of Embodiment 1 is a reflection type EC element used for an interior rearview mirror of an automobile. This EC device was manufactured by the following manufacturing method. First, as a preparation step, as shown in FIG. 1A, a first transparent substrate 1 having a rearview mirror shape made of a glass plate is prepared. A first transparent electrode layer 2 made of ITO is formed on the entire surface of the first transparent substrate 1.
As shown in FIG. 2, the entire back surface of the first transparent substrate 1 has A
The first electrode substrate 10 was formed by depositing a reflective film 8 made of 1 or the like. A second transparent substrate 7 of the same shape made of a glass plate
Was prepared, and a second transparent electrode layer 6 made of ITO was also formed on the entire surface of the second transparent substrate 7 to obtain a second electrode substrate 11. The electrical resistance of the first and second transparent electrode layers 2 and 6 is 7Ω / □.
Met.

Then, as an application step, the first electrode substrate 1
The polytungstic peroxide solution 12 is applied to the entire first transparent electrode layer 2 by a dip coating method.
Thereafter, as a solidification step, as shown in FIG. 1B, while applying a masking 13 covering the outer peripheral edge of the applied polytungstic peroxide solution 12, ultraviolet irradiation is performed to irradiate polytungstic peroxide in the central region. The solution 12 is solidified to form the EC layer 4 (see FIG. 2).

Next, as a removing step, a masking 13 is used.
Is removed, and the tungstic peroxide solution 12 other than the EC layer 4 is removed by washing with water. Then, as a sealant forming step, the EC layer 4 is surrounded by the epoxy resin 3 on the first transparent electrode layer 2 of the first electrode substrate 10. At this time, a part that is not applied is formed as an injection port for the electrolytic solution.

Thereafter, as a bonding step, a second electrode substrate 11 is provided on the epoxy resin 3 so that the EC layer 4 side becomes the second transparent electrode layer 6, as shown in FIG. At this time,
The distance between the second transparent electrode layer 6 and the EC layer 4 is set to 0.1 mm. Then, the epoxy resin 3 is cured by irradiating ultraviolet rays to form a sealant 3. Next, as an encapsulation step, an electrolyte layer 5 is interposed between the EC layer 4 and the second transparent electrode layer 6.
From the inlet. Then, an acrylic resin is applied to the injection port, and the resin is cured by irradiating ultraviolet rays, and then sealed. The electrolyte of the electrolyte layer 5 includes a 1: 1 mixture of propylene carbonate and sulfolane as an organic solvent, 0.1 M / l ferrocene as a redox agent, and 1 as a supporting salt.
M / l LiCF ₃ SO ₃ was used.

Thus, the electrolyte layer 5 and the EC layer 4 are
A reflective EC device sealed with the sealant 3 interposed between the transparent electrode layer 2 and the second transparent electrode layer 6 is manufactured.
When this EC element was left in a predetermined high-temperature, high-humidity environment, peeling of the sealant 3 did not occur even after 1000 hours. This is because, in this EC element, a sealant 3 is interposed between the first transparent electrode layer 2 and the second transparent electrode layer 6, and the electrolyte layer 5 and the EC layer 4 are sealed by the sealant 3. Therefore, the end face of the EC layer 4 is not exposed to the outside air, and the moisture in the outside air passes through the end face of the EC layer 4.
This is because the adhesive does not penetrate into the inside, so that the adhesion of the sealant 3 is appropriately maintained.

Therefore, it can be seen that, in this EC element, the sealant 3 is hardly peeled off even under high-temperature and high-humidity conditions, whereby leakage of the electrolyte in the electrolyte layer 5 can be prevented.

[0022]

Embodiment 2 The EC device of Embodiment 2 is a reflection type EC device shown in FIG. In this EC device, a reflective film 8 made of Al or the like is deposited on the entire back surface of the second transparent substrate 7.
Other configurations and manufacturing methods are the same as in the first embodiment. This E
In the C element, the same operation and effect as those of the first embodiment can be obtained.

[0023]

Third Embodiment An EC device according to a third embodiment is a transmission type EC device shown in FIG. In this EC element, the first and second transparent substrates 1 and 7 do not have a reflective film on the back surface. Other configurations and manufacturing methods are the same as in the first embodiment. This EC element can also provide the same functions and effects as those of the first embodiment.

[0024]

Comparative Example 1 As a EC element of Comparative Example 1, a reflective EC element shown in FIG. 5 was obtained. Here, a polytungstic peroxide solution was applied to the entire second transparent electrode layer 26 by dip coating, and baked at 120 ° C. for 1 hour to form the EC layer 25. Also, the first transparent electrode layer 22 and the EC layer 2
5, a sealant 23 was formed. Other configurations and manufacturing methods are the same as in the first embodiment.

Thus, a reflective EC device in which the electrolyte layer 24 is sealed by the sealant 23 interposed between the first transparent electrode layer 22 and the EC layer 25 is manufactured. When this EC element was left under the same conditions as in Example 1, peeling of the sealant 23 occurred after 100 hours.

[0026]

Comparative Example 2 As the EC element of Comparative Example 2, a reflection type EC element shown in FIG. 5 was also obtained. Here, an EC layer 25 is formed by applying a polytungstic peroxide solution to the entire second transparent electrode layer 26 by a dip coating method and irradiating the entire surface with ultraviolet rays without performing the masking 13 as in the first embodiment. did. Other configurations and manufacturing methods are the same as in the first embodiment.

Thus, a reflective EC device in which the electrolyte layer 24 is sealed by the sealant 23 interposed between the first transparent electrode layer 22 and the EC layer 25 is manufactured. When this EC element was left under the same conditions as in Example 1, peeling of the sealant 23 occurred after 100 hours.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a method of manufacturing a reflective EC device according to a first embodiment.

FIG. 2 is a schematic cross-sectional view of the reflective EC device of Example 1.

FIG. 3 is a schematic cross-sectional view of a reflective EC device of Example 2.

FIG. 4 is a schematic cross-sectional view of a transmission-type EC element according to a third embodiment.

FIG. 5 is a schematic cross-sectional view of a conventional transmission type EC element.

FIG. 6 is a schematic cross-sectional view of a conventional reflective EC device.

FIG. 7 is a schematic cross-sectional view of a conventional reflective EC device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... 1st board | substrate (1st transparent substrate) 2 ... 1st electrode layer (1st transparent electrode layer) 3 ... Sealant 4 ... EC layer 5 ... Electrolyte layer 6 ... 2nd electrode layer (2nd transparent electrode layer) 7 ... Second substrate (second transparent substrate) 8 ... Reflective film 10 ... First electrode substrate 11 ... Second electrode substrate 12 ... Composition (polytungstic peroxide solution) 13 ... Masking

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takanori Murasaki 2-1-1, Toyota-cho, Kariya-shi, Aichi Pref. Inside Toyota Industries Corporation (72) Inventor Takashi Komori 2-1-1, Toyota-cho, Kariya-shi, Aichi Pref. F-term in Toyota Industries Corporation (reference) 2K001 AA10 BB28 BB42 BB45 BB48 CA20 CA31 CA32 DA21

Claims (7)

[Claims] A first substrate, a first electrode layer formed on the first substrate, a second substrate provided facing the first substrate, and a first electrode formed on the second substrate. An electrochromic device comprising: a second electrode layer provided to face an electrode layer; and an electrolyte layer and an electrochromic layer interposed between the first electrode layer and the second electrode layer. And the electrochromic layer is sealed with a sealant interposed between the first substrate or the first electrode layer and the second substrate or the second electrode layer. element. 2. The electrochromic device according to claim 1, wherein the electrochromic layer is a porous solid. 3. An electrochromic layer comprising WO ₃ .nNb ₂
3. The electrochromic device according to claim 2, wherein O ₅ (where n is zero or a positive number) is used. 4. A first substrate, a first electrode layer, an electrolyte layer,
In a method for manufacturing an electrochromic device having an electrochromic layer, a second electrode layer, and a second substrate, the first electrode substrate having the first electrode layer formed on the first substrate; The second electrode layer is formed on the second
A preparation step of preparing an electrode substrate; a coating step of applying a liquid composition that becomes the electrochromic layer by solidification on the first electrode layer of the first electrode substrate; and a necessary portion of the composition. A solidifying step of solidifying to form the electrochromic layer; a removing step of removing the composition other than the electrochromic layer; and a sealing agent surrounding the electrochromic layer, wherein the sealing agent surrounds the electrochromic layer. Forming a sealant on the first electrode layer; bonding the second electrode substrate on the sealant such that the electrochromic layer side becomes the second electrode layer; And a sealing step of sealing the electrolyte layer between the second electrode layer and the second electrode layer. 5. The method for manufacturing an electrochromic device according to claim 4, wherein the composition is prepared by dissolving a peroxide of a transition metal. 6. A composition comprising WO ₃ .nNb ₂ O as a solute.
_The method for producing an electrochromic device according to claim 5, wherein the solution is a polytungstic peroxide solution containing ₅ (where n is zero or a positive number). 7. The method for producing an electrochromic device according to claim 6, wherein the removing step is performed by dissolving the composition with water or an organic solvent.