JPH0219445B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an electrochromic device (hereinafter abbreviated as "EC device"), and particularly relates to a method for manufacturing an electrochromic device using a gel electrolyte solution as an electrolyte solution.
The present invention relates to a method for manufacturing an element.

Conventionally, electrolyte solutions for EC devices are often solution-type solutions that use propylene carbonate as an organic solvent, and lithium iodide (LiI) as an electrolyte, or a mixture of lithium perchlorate and ferrocene. I came. However, with solution type devices, if the substrate of the EC element breaks, the electrolyte solution may scatter, or when the substrate is pressed from the outside, opposing electrodes formed on the inner surface of the substrate may come into contact with each other. It had the disadvantage of being prone to accidents such as shooting.
Furthermore, as a method for manufacturing an EC element using a solution type, an injection hole is made in one of two substrates on which an EC material layer is formed on the electrode and the electrode surface of at least one of the substrates. After forming a cell by placing these with the electrode side surfaces facing each other and sealing the periphery with a sealing material,
Alternatively, a method is usually used in which an injection hole is provided in the sealing part in advance, and after the cell is formed, an electrolyte solution is injected into the cell through the injection hole, and after the cell is filled, the injection hole is closed. According to the above, bubbles tend to remain in the cell, and the electrolyte solution tends to overflow from the injection hole, and this overflowing electrolyte solution must be removed and washed after the injection hole is closed. Ta.

For this reason, in recent years, EC devices have been studied that solve the above drawbacks by using an electrolyte solution that is made into a gel by adding an appropriate gelling agent to the solution-type electrolyte solution. Even in the manufacturing method of EC devices, the problem is how to insert the electrolyte solution between the substrates. That is, since the electrolyte solution is in the form of a gel, it is difficult to inject the gel-like electrolyte solution through the injection hole after forming the cell. For this reason, conventional methods have been considered in which the gel-like electrolyte solution is heated, the viscosity is lowered, the solution is injected into the cell of the EC element through the injection hole, and then the solution is cooled and the viscosity is increased again. However, this method had the drawback of poor work efficiency and long injection time, making it unsuitable for mass production. In addition, before applying a sealant to the substrates to form a cell, the gel electrolyte solution is sandwiched between the substrates and crushed, and after peeling off the electrolyte solution that has protruded to the outside, the surrounding area is cleaned and sealed with a sealant, and the cells are sealed. However, the form of the electrolyte solution that protrudes outside is not uniform, making it difficult to streamline the stripping process, and this method is not suitable for mass production. Moreover, the peripheral seal was incomplete and the durability was insufficient.

The present invention was made to eliminate the drawbacks of the conventional EC element manufacturing method, and provides a method for manufacturing EC elements that has good work efficiency, allows continuous production, is suitable for mass production, and has low production costs. The purpose is to provide

That is, the method for manufacturing an EC element according to the present invention includes the steps of forming a bank forming an outer frame using a sealing material at a peripheral position on the surface of the first electrode substrate on the side on which the electrode is formed, and forming a bank surrounded by the bank. a step of placing a gel electrolyte solution on the surface of the first substrate; and a step of placing a gel electrolyte solution on the surface of the first substrate; placing the second substrate on the gel electrolyte solution so as to face the surface of the first substrate; and pressing the second substrate in the direction of the first substrate. The method is characterized in that the step of placing the second substrate on the gel electrolyte solution and the step of pressing the second substrate toward the first substrate are performed under reduced pressure.

Hereinafter, the method for manufacturing an EC element of the present invention will be explained in detail with reference to the drawings.

1 to 12 are side views (partially top views) showing a typical method of the present invention. FIG. 1 shows a step of forming a bank 4 forming an outer frame using a sealing material on the first substrate 2, and FIG. 2 is a top view of the first substrate 2 on which the bank 4 is formed. In the figure, an electrode (not shown) and an EC material layer (not shown) are formed on the surface of a first substrate 2 made of glass or plastic placed on a substrate mounting table 1. ing. On this first substrate 2,
For example, a certain amount of sealant is supplied by a sealant supply device 3 such as a dispenser or a screen printer to form a predetermined width around the first substrate 2 as shown in the top view of FIG. A bank 4 forming a thick outer frame is formed. The embankment 4 may be placed with a frame-shaped film sheet or with a plurality of thread-like polymeric materials twisted together, instead of using the sealing material supply device 3.

The electrode may be made of tin oxide (SnO ₂ ), indium oxide/tin oxide (ITO), or the EC of the present invention.
When the element is used as a light control mirror, a reflective metal such as titanium nitride or the like may be used as the electrode. As the EC substance, tungsten oxide (WO ₃ ), molybdenum oxide (MoO ₂ ), etc. are used.
It is also convenient to bond solder to the end of the first substrate 2 and use it as a connection terminal for a power supply line that supplies voltage to the electrodes.

As a sealing material, it is a polymer that can be thermocompressed at 80℃ to 200℃, has high adhesive strength, low gas (especially oxygen gas) permeability, good moisture and weather resistance, and good chemical resistance. It is desired that the composition is dense and does not collapse and spread when the second substrate is pressed. The embankment 4 is formed by forming such a material into a film or thread, or melting it and applying it onto the first substrate 2. Desirable materials having such characteristics include, for example, ethylene vinyl acetate (EVA), polyethylene (PE), nylon, urethane, silicone, vinylidene chloride, ethylene ethyl acrylate, ethylene vinyl alcohol, and ethylene acrylic acid. Furthermore, if these materials are filled with a silane coupling material, an inorganic or organic filler, etc., better properties in terms of adhesive strength, gas permeability, etc. can be obtained. Furthermore, if the first substrate 2 is subjected to primer treatment in advance, more desirable characteristics can be obtained.

The optimal width of the embankment 4 varies depending on the size of the EC element, but if it is a normal small element, it is 2.
The appropriate height (film thickness) of the embankment 4 is approximately mm.
Approximately 50 μm to several mm is appropriate. More preferably, when the bank 4 is pressed and bonded with the second substrate on which the counter electrode is formed, the film thickness is 50 μm or more.
It is best to have a thickness of about 100μm, and for this purpose 60μm
It is preferable to form the height of the bank 4 to be about 200 μm or so.

FIG. 3 shows the step of placing the gel electrolyte solution 5 on the surface of the first substrate 2 surrounded by the embankment 4, and FIGS. 4 to 10 show the first substrate after this step. FIG. 2 is a top view of the substrate 2 of FIG.

In the figure, a predetermined amount of the gel electrolyte solution is placed on the surface of the first substrate 2 surrounded by the banks 4 by an electrolyte solution supply device 6 such as a dispenser. The gel electrolyte solution 5 may be applied uniformly over the entire surface of the first substrate 2 surrounded by the banks 4 by a printing method, a transfer method, a knife coating method, etc.; When the second substrate is placed on the substrate, bubbles (as described later, the process is performed in a vacuum where a slight amount of N ₂ gas is present, so they become N ₂ gas bubbles) are likely to remain. Therefore, as shown in FIGS. 3 to 11, it is recommended to swell the electrolyte solution 5 at the center of the upper surface of the first substrate 2 and spread the electrolyte solution at the center with the second substrate. desirable. At this time, the electrolyte solution 5 can be placed on the surface of the first substrate 2 by placing it uniformly in a substantially rectangular shape as shown in FIG. , those that are placed uniformly in dotted shapes, those that are placed uniformly in a circular or manual shape as shown in Figures 6 to 8, and those that are placed uniformly in a circular or manual shape as shown in Figures 9 and 10. There are various ways of placing the material, such as placing it in a relatively large lump in the center and placing it in smaller lumps on the periphery. If a small lump is provided near the area to compensate for the lack of spreading of the lumpy electrolyte solution, air bubbles will not remain. Therefore, among the mounting methods shown in Figs. 4 to 10 above, the mounting method with the larger drawing number (that is, the mounting method shown in Fig. 10 rather than the mounting method shown in Fig. 4) leaves more air bubbles. difficult and desirable. At this time, the electrolyte solution 5 is placed on the first substrate 2 in a nitrogen gas atmosphere to prevent oxidation, and the viscosity of the electrolyte solution 5 is preferably about 5000 CPS to 50000 CPS. This is done by heating, cooling, or diluting with a solvent.

The material for the electrolyte solution is γ-butyrolactone (γ-BL), propylene carbonate, butyl alcohol, or other organic solvent, and a resin that dissolves in the organic solvent to form a gel, such as urethane resin, acrylic acid resin, or oxidized resin. It is preferable to use a gel-like electrolyte solution to which other resins or copolymers thereof are added, and further a redox agent, particularly LiI, is used, but it goes without saying that the solution is not limited to these.

FIG. 11 shows the step of placing the second substrate 7 on which electrodes are formed on the gel electrolyte solution 5 with the electrode surface facing the electrode surface of the first substrate 2. As shown in FIG.
The second substrates 7 are held in a substrate holder 8 and are supplied onto the gel electrolyte solution 5 one after another. This process is carried out in a vacuum chamber (not shown) under a nitrogen gas atmosphere, and it is desirable to maintain the pressure of the residual nitrogen gas at about 10 Torr to 60 Torr. Further, the temperature of the substrate mounting table is preferably about 50°C. If the degree of vacuum is too high or the temperature is too high, the solvent in the electrolyte solution 5 will vaporize and begin to foam; if the degree of vacuum is too low, bubbles will form in the cells when pressing the second substrate 7 to form the cells. This is because there is a higher possibility that the remaining particles will remain.

The electrodes formed on the second substrate 7 are the same as those on the first substrate 2.
As with the electrodes, metals such as SnO ₂ , ITO, or TiN are used. Moreover, on the electrode of the first substrate 2
If an EC material layer is not formed, an EC material layer such as WO ₃ is formed on the electrode of this second substrate 7.
Note that, like the first substrate 2, both the electrode and the EC material layer are not shown.

FIG. 12 shows the process of pressing the second substrate 7 toward the first substrate 2 from the back side. This process is carried out in a vacuum chamber (not shown), similar to the process shown in FIG.
The process is carried out in a vacuum with an N ₂ gas pressure of 10 Torr to 60 Torr, and the second substrate 7 is pressed onto the first substrate using a known pressing device 9.
The four peripheries of both substrates are sealed with a sealing material to form a cell. At this time, the temperature in the vacuum chamber is 80°C to 200°C, and the pressure for bonding the second substrate 7 to the first substrate 2 is 1Kg/cm ² to 7Kg/cm ^{2 .}
It is desirable to maintain a certain level in terms of the spread of the electrolyte solution and the pressure bonding of the sealing material to each substrate 2, 7.

When the second substrate 7 is pressed from above by the pressing device 9, the surface of the substrate 7 first presses the gel-like electrolyte solution 5, and the electrolyte solution 5 spreads on the surface of the first substrate 1. It extends and comes into contact with the embankment 4 which becomes the outer frame,
It further extends along the embankment 4. Then dam 4 is the second
The substrate 2 is compressed by being pressed against the surface of the substrate 7,
Press the four peripheries of No. 7 to form a cell. The size of the gap between the first and second substrates 2 and 7 is
It is regulated by the pressure with which the substrate 7 is pressed, the temperature of the sealing material part of the vacuum chamber, the height of the embankment 4, and the amount of gel electrolyte solution 5. In this way, the cell formed by the first and second substrates 2, 7 and the bank 4 was filled with the gel electrolyte solution 5, and by keeping the cell in this state in a vacuum chamber for several minutes, the bank 4 was filled. The pressure bonding of the sealing material forming the cell to both substrates 2 and 7 is completed, and a strong cell is formed. In addition, after this, _N2 gas is introduced into the vacuum chamber to bring the pressure to 1 atmosphere, and the cell is taken out from the vacuum chamber into the atmosphere. The cells are completely filled with the electrolyte solution and have no air bubbles.

The EC element cell is completed through the above steps.
Sufficient durability can be obtained with only the sealing material bank 4, but as shown in the cross-sectional view in FIG. This increases durability. The secondary sealing material 10 may be formed using a material such as butyl rubber, fluororesin, vinylidene chloride resin, or epoxy by a method such as fusion bonding. In addition, the first
Reference numeral 11 in FIG. 3 indicates a solder layer, which is formed at the ends of the first and second substrates 2 and 7 and is used to solder a power supply line connected to an external power source.

Hereinafter, the method for manufacturing an EC element of the present invention will be explained in more detail by showing specific examples.

Example 1 A gel electrolyte solution was prepared by dissolving 25 g of dehydrated polyvinyl butyral in 50 ml of a deoxygenated and dehydrated 0.75M LiI, γ-butyrolactone solution under an N ₂ gas atmosphere. A substrate formed by depositing only an ITO film as an electrode on a 10 cm square glass substrate, and
A substrate is prepared by forming _three layers of WO as an EC material layer on the film by a vapor deposition method, and solder that can be welded to glass is attached to the edge of each substrate, as shown in FIG. was formed. At this time, the sheet resistance of the ITO film was 10Ω, and the thickness of the WO ₃ layer was 5000 Å.

Next, an EVA film with a thickness of 100 μm was used as a sealing material, and as shown in FIG. 14, it was shaped into a rectangular frame with a hole in the center of the same size as the substrate. At this time, the width d of the frame was 2 mm. this
The frame of the EVA film is the first layer on which the ITO film is formed.
It was placed on a substrate and used as an embankment.

Next, 0.55 g of the gel electrolyte solution was applied from a dispenser onto the surface of the first substrate surrounded by the bank in the pattern shown in FIG. This step was performed under an inert atmosphere filled with _N2 gas in a vacuum chamber.

Next, the N ₂ gas is degassed to 30 Torr, and the first
The second substrate was formed with an ITO film and _three WO layers.
The WO ₃ layer forming surface of the substrate is replaced with the ITO layer of the first substrate.
It was placed on top of the mass of the gel electrolyte solution, facing the membrane forming surface, and pressed from the back side with a pressing device. The pressing force at this time was 5 kg/cm ² , and the sealing material portion in the vacuum chamber was heated to 110° C. and pressurized for 3 minutes.

Thereafter, N ₂ gas was introduced to bring the pressure inside the vacuum chamber to atmospheric pressure, and the chamber was left to cool, thereby fixing the sealing material to both substrates.

A power supply line for connecting an external power source was soldered to the solder layer on the end surface of the substrate, and the end surface was sealed with epoxy adhesive as a secondary sealant 10, as shown in FIG. 13, to produce an EC element.

Example 2 A gel electrolyte solution was prepared in the same manner as in Example 1,
In addition, in the same manner as in Example 1, two glass substrates were prepared on which only an ITO film or _three WO layers of an ITO film were deposited and a solder layer was formed on the edges. A hot-melt type EVA was applied using a dispenser to a thickness of 100 μm and a width of 2 mm on the four peripheries of the surface on which the ITO film was formed to form banks.

The first substrate on which the bank has been formed is placed in a vacuum chamber, and the gelled electrolyte solution is heated to lower its viscosity, and then a dispenser is used to apply the gelled electrolyte solution onto the surface of the substrate surrounded by the bank as shown in FIG. The electrolyte solution was applied in a similar pattern. By lowering the viscosity in this way, the electrolyte solution could be easily applied onto the first substrate.

Similarly to Example 1, another glass substrate was placed and pressed on the gel electrolyte solution in a vacuum state,
After holding at atmospheric pressure, a power supply line was soldered to the end.

Next, the periphery was secondarily sealed with hot melt type butyl rubber to produce an EC element.

Example 3 Instead of the hot melt type EVA of Example 2,
EVA was dissolved in a solvent such as tenalahydrofuran (THF), butyl acetate, cyclohexane, dichloroethane, xylene, carbon tetrachloride, etc., and a silane coupling material was added to the solution. The seal material created in this way is a hot melt type.
Stronger adhesive strength was obtained compared to EVA.

Example 4 Instead of the hot melt type EVA of Example 2,
We used a sealing material that is a blend of hot melt type EVA and polyvinylidene chloride. This sealing material showed excellent properties in terms of moisture resistance and oxygen permeation resistance.

Example 5 A gel electrolyte solution and a glass substrate were created in the same manner as in Example 2, and on one of the four peripheries of the glass substrate,
As shown in FIG. 15, hot melt type butyl rubber is applied using a dispenser to form a first outer frame 12, and hot melt type EVA is applied to the inside of the first outer frame 12 using a dispenser as well. The second outer frame 13 was formed by applying the second outer frame 13 to form a double bank. After this, no secondary seals are applied to the outside of the first and second substrates.
An EC element was manufactured in the same manner as in Example 2.

In this example, by forming a double bank, high sealing performance was obtained without applying a secondary seal to the outer end surface of the substrate.

As explained above, in the method for manufacturing an EC element of the present invention, a bank forming an outer frame is formed using a sealing material at a peripheral position on the surface of the first substrate, and the first substrate surrounded by the bank is A gel-like electrolyte solution is placed on the surface of the cell, and a second substrate is pressed onto the cell under reduced pressure to form a cell, so that the electrolyte solution does not protrude outside the cell. There is no need to remove and clean the protruding electrolyte solution, and there is no need to heat the gel electrolyte solution to lower its viscosity before injecting it into the cell, resulting in extremely high work efficiency. Furthermore, no air bubbles remain in the cell, and therefore, the electrolyte solution or redox agent will not be oxidized by the remaining air bubbles and the EC element will not deteriorate, and the electrolyte solution is placed one after another on the first substrate in a vacuum chamber. By pressing the second substrate to form cells, it is possible to achieve the effect that continuous productivity is excellent and it is suitable for mass production and production costs are also reduced.

[Brief explanation of drawings]

Figures 1 to 12 are side (partially top) views showing typical examples of the method for manufacturing the EC element of the present invention;
Figure 3 is a sectional view showing the state in which the secondary sealant is applied, Figure 14 is a top view showing one embodiment of the embankment, and Figure 1
FIG. 5 is a top view showing another embodiment of the embankment. DESCRIPTION OF SYMBOLS 1... Substrate mounting stand, 2, 7... Substrate, 3... Seal material supply device, 4... Bank, 5... Gel electrolyte solution, 6...
Electrolyte solution supply device, 8... Substrate holder, 9... Pressing device, 10... Secondary sealing material layer, 11... Solder layer.

Claims (1)

[Claims] 1. An EC material layer is further formed on at least one electrode surface of the first and second substrates on which electrodes are formed, and the electrodes of the first and second substrates are formed. In the method for manufacturing an electrochromic device, the electrochromic device is sealed by sandwiching and sandwiching a gel electrolyte with the surface of the first substrate facing inside, wherein a sealing material is used at a peripheral position on the surface of the first substrate on which the electrode is formed. forming a bank forming an outer frame; placing a gel electrolyte solution on the surface of the first substrate surrounded by the bank; and placing the second substrate on an electrode of the second substrate. placing the second substrate on the gel electrolyte solution so that the surface on which the electrodes are formed faces the surface of the first substrate on which the electrodes are formed; and placing the second substrate in the direction of the first substrate. The step of placing the second substrate on the gel electrolyte solution and the step of pressing the second substrate toward the first substrate are performed under reduced pressure. A method for manufacturing an electrochromic device characterized by the following. 2. The step of forming a bank forming an outer frame using a sealing material at a peripheral position on the surface of the first substrate on the side where the electrodes are formed is performed at a peripheral position on the surface of the first substrate on the side where the electrodes are formed. The electrochromic device according to claim 1, which is a step of forming a double bank by a first outer frame formed on the inside of the first outer frame and a second outer frame formed inside the first outer frame. manufacturing method.