JPH01239533A - Electrochromic display element - Google Patents

Abstract

PURPOSE:To improve the reliability of leads on a counter electrode side by making a counter electrode substrate of metal, providing a display electrode substrate and a conduction part to the metallic counter electrode substrate integrally and bringing the conduction part into contact with a transparent conductive film of the display electrode substrate. CONSTITUTION:The counter electrode substrate 5 is formed of a stainless steel plate, and the display electrode substrate 1 and conduction part 13 are provided at the outer peripheral end of the counter electrode substrate 5 integrally. Then the conduction part 13 consists of a vertical part 13a and a horizontal part 13b and the vertical part 13a extends upward from the outer peripheral end of the counter electrode substrate 5 along the outer peripheral surface of a spacer 10; and the horizontal part 3b projects from the tip of the vertical part 13a and the top surface of the horizontal part 13b contacts the transparent conductive film 1b of the display electrode substrate 1. Consequently, leads between counter electrode lead terminals 12 fitted to the display electrode substrate 1 and the counter electrodes substrate 5 never become unstable and the reliability of the leads of the counter electrode side is improved.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electrochromic display element, and more particularly, to a lead on the opposite pole side thereof, that is, a lead terminal on the opposite pole attached to a display electrode substrate. This invention relates to improvements in electrical connection with a counter-polar substrate.

[Conventional technology]

In order to cause the electrochromic material on the display electrode of the electrochromic display element to undergo a coloring reaction and exhibit its display function, it is necessary to supply electricity to the electrochromic display element from an external driving power source. The connection between this driving power source and the electrochromic display element is generally performed by attaching lead terminals to the display electrode substrate of the electrochromic display element and connecting the lead terminals and the driving power source with lead wires. .

By the way, when attaching the lead terminals to the display electrode board as described above, it is of course necessary to attach the lead terminals on the display electrode side (hereinafter referred to as display electrode lead terminals) to the display electrode board, but recently, workability etc. Due to the relationship, the lead terminal on the opposite pole side (hereinafter referred to as the opposite pole lead terminal)
As shown in FIG. (The display terminal is electrically insulated from the terminal 11.)

The electrical connection (hereinafter referred to as a lead) between the opposite electrode terminal 12 attached to the display electrode substrate 1 and the opposite electrode substrate 5 is made by connecting the silver paste 4 to the opposite electrode as shown in FIG. The transparent conductive film 5b of the lead terminal 12 and the counter electrode substrate 5 (,
As the counter homopolar substrate 5, a transparent conductive film 5b formed on a glass plate 5a is generally used.
520 Publication).

[Problem to be solved by the invention]

However, when silver paste) 14 comes in contact with air, the silver is oxidized and electrical conductivity is impaired, and the coefficient of thermal expansion is different from that of the resin spacer 10 made of synthetic resin such as polyester. Cracks occur in the silver paste mesh 4, making electrical conduction unstable, and as time passes, the amount of electricity that can be injected into the electrochromic material of the display electrode decreases, resulting in a decrease in color density.

As mentioned above, in the conventional electrochromic display element, the lead between the counter electrode lead terminal 12 and the counter electrode substrate 5 is made by the silver base) 14, and therefore the electrical conduction thereof lacks stability. The purpose is to solve the problem that caused the coloring density to decrease and to improve the reliability of the lead for the same polar case.

(Means for Solving the Problems) The present invention provides a method in which a counter-homoelectrode substrate is made of metal, a conductive portion with a display electrode substrate is integrally provided on the metal counter-electrode substrate, and the conductive portion is connected to a display electrode. It is brought into contact with the transparent conductive film of the substrate.

[Function] Since a conductive part with the display electrode substrate is integrally provided on the counter homopolar substrate and the conductive part is brought into contact with the transparent conductive film of the display electrode substrate, the counter electrode lead attached to the display electrode substrate The lead between the terminal and the opposite electrode substrate does not become unstable, and the reliability of the lead between the opposite electrode and the same electrode is improved.

〔Example〕

FIG. 1 is a schematic perspective view and an enlarged cross-sectional view of essential parts of an embodiment of the electrochromic display element of the present invention, and FIG. FIG. 2 is a schematic perspective view of a substrate.

In the figure, 1 is a display electrode substrate, and this display electrode substrate 1 is formed by forming a transparent conductive film 1b of doFO (indium tin oxide) on a transparent substrate 1a made of a transparent glass plate. A display electrode 3 is fabricated by forming a layer 2 of an electrochromic material on the transparent conductive film lb of the display electrode substrate 1. In this embodiment, a vapor-deposited film of silicon oxide (Sing) for protecting the transparent conductive film is formed on the transparent substrate 1a of the display electrode substrate 1 and on the transparent conductive film lb where the electrochromic material layer 2 is not formed. A protective film 4 is formed thereon, and this protective film 4 is also a component of the display electrode 3, but this protective film 4 is not necessarily necessary from the viewpoint of the display function of the display electrode 3.

In this embodiment, the electrochromic material layer 2
is formed by vapor deposition of tungsten oxide (wO3), and the electrochromic material layer 2 is formed by 7
It is formed so as to form one figure-eight-shaped digit by a collection of segments, and is arranged inside the element.

5 is a counter-homopolar substrate, and a counter-pole 7 is fabricated by forming a counter-pole material layer 6 on this counter-homopolar substrate 5.

The counter homopolar substrate 5 is made of a stainless steel plate (SUS304) and has a thickness of 0.311II11, and a conductive portion 13 with the display electrode substrate 1 is integrally provided at the outer peripheral edge of the counter homopolar substrate 5. There is. Furthermore, this integrated provision means that
This means that the counter-homopolar substrate 5 and the conductive part 13 are provided in metal-to-metal contact, and it does not literally mean that the counter-homopolar board 5 and the conductive part 13 are integrally formed. For example, the counter electrode substrate 5 and the conductive portion 13 may be manufactured separately and then welded together using a low melting point alloy or the like. The conductive portion 13 has a vertical portion 13a.
and a horizontal part 13b, the vertical part 13a extends upward along the outer peripheral surface of the spacer 10 from the outer peripheral end of the counter electrode substrate 5, and the horizontal part 13b projects horizontally from the tip of the vertical part 13a, The upper surface of the horizontal portion 13b is the display electrode substrate 1.
The transparent conductive film 1b is in contact with the transparent conductive film 1b. In this example,
The width of this conductive portion 13 is 1.5 mm for both the vertical portion 13a and the horizontal portion 13b. It's omm.

The counter electrode material layer 6 is formed by using activated carbon fiber cloth as a counter electrode material and adhering and fixing it on the counter electrode substrate 5 with a conductive adhesive called carbon paste. 6 is disposed inside the device so as to face the electrochromic material layer 2 of the display electrode 3.

8 is propylene carbonate with LiCl0. 1.0r
The electrochromic material layer 2 is a liquid electrolyte in which water is added at a ratio of 1 part by volume to 100 parts by volume of propylene carbonate;
The display electrode substrate 1 and the counter electrode material layer 6 are arranged between the display electrode substrate 1 and the counter electrode substrate 5. 9 is a background material made of an ion-permeable polytetrafluoroethylene film containing titanium dioxide dispersed therein;
The electrochromic material layer 21 is disposed between the counter electrode material layer 6 and is white in color and hides the counter electrode material layer 6.
However, depending on the type of electrochromic material and the type of counter-homopolar material, this is not always necessary, and the periphery of the display electrode substrate 1 and the counter-electrode substrate 5 may be A polyester spacer lO is interposed between the periphery and the spacer IO is adhesively fixed to the periphery of the display electrode substrate 1 and the counter electrode substrate 5 using an epoxy resin adhesive or the like. Spacer 10 and bipolar substrate! , 5 form a sealed chamber that accommodates element contents such as the electrochromic material N2, the electrolyte 8, the background material 9, and the counter electrode material layer 6.

The opposite pole lead terminal 12 has a clamping part 12a and a clamping part 12a.
a and a vertical part 12b extending downward, and the clamping part 12a has an upper clamping piece and a lower clamping piece,
It is attached to the display electrode substrate 1 so that the end portion of the display electrode substrate 1 is held between the two clamping pieces. As shown in the whole part of FIG. 1, the counter electrode lead terminals 12 are attached to both ends of the display electrode substrate 1, and all other lead terminals are the display electrode side lead terminals 11 on the 0 display electrode side. The structure of the lead terminal 11 itself is similar to that of the opposite electrode lead terminal 12, but the reason why there are a large number of lead terminals as shown in the figure is that each segment of the electrochromic material layer 2 is independently mated. This is to supply electricity to each segment independently so that a color reaction can occur. Although not clearly shown in the drawings, the transparent conductive film 1b of the display electrode substrate l also has a number of segments in the electrochromic material layer 2 so that electricity can be supplied independently to each segment of the electrochromic material layer 2. It is divided into multiple pieces depending on the situation.

The following Table 1 shows the initial state (before storage) and 40% of the electrochromic display element of the present invention shown in Fig. 1 and the conventional electrochromic display element (conventional product) shown in Fig. 3.
The figure shows the amount of electricity injected during coloring for 1.2 seconds and 0.6 seconds after storage for 30 days at 5° C. without humidification. The electrochromic display elements used in the above tests were all 7D elements (in the drawings, for the sake of simplicity, the electrochromic material layer is (Only two digits are shown), and the number of samples tested was 10 for each electrochromic display element.
The test results are shown for each sample (indicated by samples 1 to 10) in each electrochromic display element and their average value.

As shown in Table 1 above, in the electrochromic display element of the present invention, the decrease in the amount of injected electricity due to storage was as small as 0.1 mC/cd on average, whereas in the conventional electrochromic display element, the decrease in the amount of injected electricity due to storage was as small as 0.1 mC/cd. The amount decreases by 1
．． It was as large as 5mC/cd. In addition, in some conventional electrochromic display elements, such as Sample Nα9 and Sample Nα10, the amount of electricity injected due to storage decreases as much as 2.2 mC/c4, whereas in Sample Nα3, the amount of electricity injected due to storage decreases as much as 2.2 mC/c4. There were variations in the decrease in the amount of electricity injected due to storage, with some exhibiting a decrease of 0°5 mC/cJ. Of course, in the electrochromic display element of the present invention, the decrease in the amount of injected electricity due to storage was small, and there was also little variation in the decrease in the amount of injected electricity between samples.

As described above, in the conventional electrochromic display element, since the lead between the counter electrode lead terminal 12 and the counter electrode substrate 5 is established by the silver paste 4, the lead paste 14
However, in the electrochromic display element of the present invention, the conductive portion 13 with the display electrode substrate 1 is integrated with the counter electrode substrate 5, and the electrical conduction becomes unstable due to oxidation of the electrode. Since the conductive portion 13 is brought into contact with the transparent conductive film 1b of the display electrode substrate 1, a large decrease in the amount of injected electricity due to storage as seen in conventional electrochromic display elements does not occur.

In the above embodiment, the counter electrode substrate 5 is made of stainless steel (
SUS304) was used, but it is not limited to this.
Other stainless steels such as 5US316.5US430 may also be used, or any corrosion resistant metal such as titanium may be used.

In addition, although tungsten oxide was used as the electrochromic material of the display electrode in the example, Ir,
Transition metal oxides such as O□ and MnO+, Prussian blue, tetrathiafulvalene derivatives, viologen derivatives, etc. can also be used. Furthermore, in the examples, activated carbon fiber cloth was used as the counter-homopolar material, but the material is not limited thereto, and iron tungstate, M n O! , M n
O:l etc. can also be used. Furthermore, the electrolyte is not limited to those exemplified in the examples, and any electrolyte, liquid or solid, can be used as long as the ionic species necessary for coloring and decoloring reactions can be transferred.

[Effects of the Invention] As explained above, in the present invention, the counter homopolar substrate 5 is made of metal, and the counter homopolar substrate 5 is integrally provided with the conductive portion 13 with the display electrode substrate l. By bringing 13 into contact with the transparent conductive film 1b of the display electrode substrate 1, the reliability of the lead on the opposite side was improved, and an electrochromic display element with less decrease in the amount of injected electricity due to storage could be provided. .

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing an embodiment of an electrochromic display element of the present invention and an enlarged cross-sectional view of its essential parts. FIG. 2 is a schematic perspective view of a counter homopolar substrate used in the electrochromic display element shown in FIG. 1. FIG. 3 is a schematic perspective view showing a conventional electrochromic display element and an enlarged sectional view of its main parts. l... Display electrode substrate, 1a... Transparent substrate, 1b.
...Transparent conductive film, 2... Electrochromic material layer, 5... Counter electrode substrate, 6... Counter electrode material layer,
8... Electrolyte, 13... Conductive part with display electrode substrate 1 Figure 2 1 Display electrode substrate 1a Transparent substrate 5 Counter electrode substrate 6... Counter electrode material layer 8... Electrolyte 13・Conductive part with display electrode board

Claims (1)

[Claims] (1) At least an electrochromic material layer 2, an electrolyte 8, and a counter electrode material layer 6 are arranged between a display electrode substrate 1 formed by forming a transparent conductive film 1b on a transparent substrate 1a and a counter electrode substrate 5. In the chromic display element, the counter electrode substrate 5 is made of metal, a conductive portion 13 is integrally provided on the counter electrode substrate 5 and the display electrode substrate 1, and the conductive portion 13 is connected to the transparent conductive film of the display electrode substrate 1. An electrochromic display element characterized in that it is in contact with 1b.