JPS61228423A - Method for constituting electrochromic display element - Google Patents

Abstract

PURPOSE:To prevent deterioration in display quality due to foaming by reducing at least one of a color developing layer and its opposite electrode in advance before fabrication. CONSTITUTION:The preliminary by using constant-potential electrolytic reducing process is carried out before fabrication by using the color developing layer, generally combined with a base plate electrode into one body, as a cathode, with respect to an opposite electrode at the time of electrolytic reduction, and maintaining this cathode at an optional constant potential with respect with the potential of a standard electrode, thus permitting the reduction extent of the color developing layer to be controlled considerably exactly. For example, the electrolytic reduction process can be executed by using the color developing layer prepared by vapor depositing tungsten oxide on a transparent conductive base, a platinum black-attached platinum plate as an opposite electrode, and a silver-silver chloride electrode as the standard electrode, and setting the potential of the color developing layer electrode to -1.5-+0.3V, preferably, -0.5-+0.2V with respect to that of the standard electrode in an aq. soln. of 1N H2SO4 with a potentiostat.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an electrochromic display (hereinafter referred to as EC).
(also abbreviated as D) relates to a method of configuring an element.

(Prior art and problems to be solved by the invention) ECD
The device is a display device that utilizes changes in light absorption caused by electrochemical redox reactions in the coloring layer. In general, ECD elements are subjected to so-called aging that repeats coloring and decoloring at a relatively high voltage before being used for normal use, so that compared to ECD elements, even when driven at the same voltage, the ΔOD is larger, that is, when coloring and decoloring. It is known that differences in the degree of light absorption during color can be obtained and response speed can be improved.

Furthermore, since it becomes possible to drive the ECD element with a low voltage, it is expected that the lifespan will be improved. In addition, in the type 0 ECD element, which has a monoxide coloring layer and a reduction coloring layer facing each other, the transmittance when decoloring increases. It is also known to improve

On the other hand, in ECD elements that do not undergo aging,
When driven with a constant voltage, ΔOD often increases gradually in proportion to the number of repetitions, and for this reason, E
It is not possible to control the coloring state of the CD element, and there is a tendency for differences in the coloring state between segments to occur, resulting in color unevenness.

Therefore, in general, it is preferable to perform aging blowfish, but on the other hand, bubbles are often observed inside the aging device, and especially when the voltage on the A-Song is high or the A-Song top gap is long, air bubbles The occurrence of is remarkable.

The generation of bubbles significantly deteriorates the display quality of the ECD element, and also causes deterioration, posing a problem for ASONG.

The inventor of the present invention has conducted extensive research to address such Ason problems, and as a result has found that the generation of bubbles is related to the decomposition of water. That is, 2H20→2H++1/20□↑+
It was found that the oxygen 02 produced by the decomposition of water by 26 is the cause of bubbles, and that the hydrogen ions H+ produced at the same time increase the total amount of ions involved in coloring and fading, resulting in an increase in ΔOD. Ta.

Based on this knowledge, the present invention provides an increase in ΔOD equal to or greater than that achieved by aging; an improvement in response speed;
The present invention provides a method for constructing an ECD element that improves the characteristics of a CD element and does not cause deterioration or deterioration of display quality due to the generation of bubbles.

(Means for Solving the Problems) The present invention is a method of configuring an ECD element in which, when configuring the ECD element, at least one of the coloring layer and its counter electrode is subjected to a reduction treatment in advance before configuring the ECD element. .

In the present invention, materials for the coloring layer and its counter electrode may be those that are conventionally known as materials generally used for the coloring layer and its counter electrode, as well as materials that have the functions thereof. Specifically, the materials for the coloring layer include tungsten oxide, molybdenum oxide, titanium oxide, vanadium oxide, chromium oxide, iridium oxide, iridium hydroxide,
Inorganic materials such as nickel hydroxide, rhodium hydroxide, niobium oxide, biorodane, rare earth diphthalocyanine/,
Organic materials such as TTF polystyrene and viologen polymer are used.

Examples of the counter electrode include a mixed compact of a carbon material with a large specific surface area, such as carbon or graphite, and an iron complex or tungsten oxide powder.

The reduction treatment in the present invention includes electrical reduction treatment and chemical reduction treatment.

The reduction treatment of the coloring layer will be explained below as an example.

Electrical reduction treatment refers to a substrate on which a color-forming layer is generally integrated, for example, a transparent conductive substrate, with a substrate on which a color-forming layer is integrated by means of vapor deposition, etc. as one electrode, and the electrode is electrolyzed. This is a method of electrolytic reduction by applying a voltage in an electrolyte solution so that the electrode becomes a negative electrode with respect to the original counter electrode. As the counter electrode, an inert electrode such as platinum or a platinum plate with black platinum is usually used.

However, in the case of simply electrolyzing with two electrodes in this way, it is impossible to control the amount of reduction in the coloring layer, in other words, the amount of ions injected or extracted, or the amount of charge injected or extracted (hereinafter simply referred to as the amount of injected charge). Since this is somewhat difficult, the amount of charge injected differs between ECD elements or segments, and as a result, there is a tendency for ΔOD to vary widely when driven with the same voltage. To deal with this, the following constant potential electrolytic reduction method and constant current electrolytic reduction method are recommended.

What is the constant potential electrolytic reduction method? Color forming layer Generally, a substrate electrode with an integrated color forming layer (hereinafter referred to as color forming layer electrode) is used as a cathode with respect to a counter electrode during electrolytic reduction, and the potential of the cathode is set relative to a reference electrode. Electrolytic reduction is carried out while maintaining a constant potential, and by setting the potential of one color-forming layer electrode to an arbitrary value, the amount of reduction in the color-forming layer can be controlled quite accurately. The operation of keeping the potential of the coloring layer electrode constant can be easily carried out by using, for example, a commercially available potentiostat.

The preferred potential of the color forming layer electrode with respect to the reference electrode is usually -1
, 5v to +0.3v, and further -0.5v to +〇, 2v.

Specifically, for example, a tungsten oxide vapor deposited on a transparent conductive substrate is used as the coloring layer electrode, a platinum black plate with platinum is used as the counter electrode, and a silver-silver chloride electrode is used as the reference electrode. The potential of the color forming layer electrode is set to -1, preferably -1, with respect to the reference electrode using a potentiostat.
What is necessary is just to set it to 5v - +0.3v, and furthermore, -0.5v - +0.2v, and just to carry out electrolytic reduction. As a result, a phenomenon in which the tungsten oxide on the color-forming layer electrode becomes colored is observed. This means that hydrogen ions H+ were implanted and reduced.

For example, tungsten oxide is deposited on a transparent conductive substrate to obtain 10 similar coloring layer electrodes, a platinum black plate is used as a counter electrode, and -o,
osv was electrolytically reduced for 1 hour, and there was almost no difference in ΔOD at a given voltage between the ECD devices constructed using the same.

As described above, in the constant potential electrolytic reduction method, since the coloring layer is not reduced to a potential lower than the set potential, it is easy to reduce the amount of the coloring layer to a desired amount by making the electrolysis time relatively long.

Furthermore, in the constant current electrolytic reduction method, the color forming layer electrode is used as a full cathode, and electrolytic reduction is carried out while the current flowing through the color forming layer electrode, that is, the current flowing through the color forming layer, is kept constant, and the amount of electricity related to the amount of reduction is has the advantage that it can be easily determined as the product of current value and electrolysis time. The operation of maintaining a constant current flowing through the coloring layer electrode can be easily carried out using a commercially available galvanostat. However, in order to accurately determine the amount of charge to be injected, the current efficiency must be 100%. That is, it is necessary that the entire amount of electricity that flows is used only for the reaction in which ions are injected into or extracted from the coloring layer, and that no side reactions such as electrolysis of impurities or generation of hydrogen gas occur. Therefore, the electrolyte solution to be used is not preferably an electrolyte substance that causes severe electrolysis under electrolytic conditions, that is, causes a side reaction on the coloring layer side of the cathode. However, even with such an electrolyte substance, side reactions can be suppressed by lowering the set current value, and it is generally better that the current value is not too high. The range of the current value usually preferably used as the current flowing through the coloring layer electrode is 1 μA/cm” to 10 mA.
/J is further 5 μA/z” to 1 mA/cn”. Specifically, for example, a tungsten oxide vapor deposited on a transparent conductive substrate is used as a coloring layer electrode, and lN-H
When constant current electrolysis is performed in a 2SO4 aqueous solution, the set current value is set in the range of 1 pA/cm'' to 10 mAlt-, and electrolytic reduction is performed for a certain period of time ranging from several seconds to several tens of minutes, thereby reducing tungsten oxide. It is possible to implant hydrogen ions of several millicoulombs/cm" to several tens of millicoulombs/erR" into the coloring layer. Using a tungsten oxide coloring layer that has been subjected to such reduction treatment, ECD
When the device was constructed, the ΔOD was 0 in the reflection mode compared to an ECD device similarly constructed without reduction treatment.
．． An improvement of 2 or more was observed. Further, when eight 0ECD elements with the same amount of charge injected through constant current electrolytic reduction treatment were driven with the same voltage, the variation in ΔOD was extremely small.

Further, in addition to the case where the coloring layer in the ECD element is a single layer, in a more preferable embodiment, a plurality of coloring layers such as a reduced coloring layer of tungsten oxide and an oxidized coloring layer of iridium oxide may be used.

In such a case, in the present invention, at least one coloring layer may be subjected to a reduction treatment. For example, for the coloring layer of iridium oxide, preferably 5 millicoulombs/611" to 200 millicoulombs/1M12, more preferably 30 millicoulombs,
Ions are implanted in the range of 4 to 100 milliCoulombs/sub2, or preferably 3 to 3
Ions are implanted in the range of millicoulombs/cIn2 to 50 millicoulombs/cM1, more preferably 5 millicoulombs/cWl" to 30 millicoulombs/cm", or the above-mentioned ions are implanted into both the iridium oxide and tungsten oxide coloring layers, respectively. There is an embodiment in which a gcD element is constructed using a plurality of color-forming layers after ion implantation within a range of Improvements in speed and life characteristics, etc. 0
It is possible to improve the characteristics of the ECD element.

Various electrolyte solutions can be used in the electrical reduction treatment described above. That is, the electrolyte solution may be acidic, neutral, or alkaline, and may be an aqueous solution or an organic solution as long as it contains an electrolyte.

However, depending on the material of the coloring layer, for example, some materials may be stable in acidic solutions but unstable in alkaline solutions.
Good vocal fluids should be adopted accordingly. For example, in the case of a coloring layer made of tungsten oxide, an acidic electrolyte solution should be used because it is more stable in an acidic environment than in an alkaline environment.

Typical electrolyte solutions used in the present invention include electrolyte inorganic acid aqueous solutions such as sulfuric acid, hydrochloric acid, and nitric acid; aqueous solutions containing electrolytes such as sodium sulfate, sodium chloride, and potassium chloride; Examples include aqueous electrolyte alkaline solutions such as potassium and ammonia, and organic solutions such as globylene carbonate, γ-butyrolactone, and acetonitrile containing electrolytes such as perchloric acid, lithium perchlorate, sodium perchlorate, and potassium perchlorate.

Further, the reduction treatment in the present invention can be performed not only by electrical reduction treatment but also by chemical reduction treatment described below. Chemical reduction treatment is generally carried out by preparing a solution of a reducing agent at an appropriate concentration and immersing the coloring layer, generally the substrate with which the coloring layer is integrated, in the solution for an appropriate amount of time.

Typical reducing agents include sodium borohydride, ferrous chloride, potassium ferrocyanide, L-ascorbic acid, hydroquinone, hydrazine, hydrogen iodide, hydrogen sulfide, formic acid, oxalic acid, and the like. From among these reducing agents, an appropriate reducing agent may be selected in consideration of the material of the coloring layer and the like. For example, in the case of a coloring layer made of tungsten oxide, a reducing agent exhibiting alkalinity such as sodium borohydride is not preferable because it dissolves in an alkaline solution. To specifically describe a coloring layer made of iridium oxide as an example, an acidic reducing agent such as L-ascorbic acid is preferably used as the reducing agent, and the concentration is usually preferably o, oi to 2 tnol/l. Preferably 0
．． The reduction treatment in the present invention can be sufficiently carried out by immersion in an aqueous solution with a concentration of 1 to 1 mol/l for 10 minutes to 1 hour.

This type of chemical reduction treatment does not require the trouble of attaching lead wires to the individual coloring layer electrodes and electrolyzing them, as is the case with the electrical reduction treatment described above. Even in the case of having a colored layer, it is advantageous in terms of productivity because it only requires immersion in a solution containing a reducing agent.

Although the above description has been made by taking the coloring layer as an example, the reduction treatment may be performed in the same manner when the counter electrode of the coloring layer is subjected to the reduction treatment.

That is, in the electrical reduction process, electrolytic reduction may be performed by applying a voltage in an electrolytic solution using the counter electrode as a cathode with respect to the counter electrode during electrolytic reduction. In the chemical reduction treatment, the counter electrode may be reduced in a solution containing an appropriate reducing agent.

In addition, what should be noted in the present invention is that the amount of reduction in the reduction process, that is, the amount of charge injected, is generally based on the ECD
There is a proportional relationship between the ΔOD of the element and the amount of charge injected at that time, and the proportionality constant at this time is the coloring efficiency ηcm"
/ expressed in coulombs. Here, η is defined as the area where a color change of ΔOD −1 is obtained with a charge amount of 1 coulomb. In other words, the smaller η is, the lower the power consumption is possible.

Therefore, if the desired values of ΔOD and display area are determined at the design stage of the ECD element, the amount of charge to be injected can be calculated.

Although the amount of charge injected in the reduction treatment of the present invention cannot be determined unconditionally because it is related to many factors such as the substances in the electrolyte layer described above, the amount of charge injected in the reduction treatment of the present invention is 1.5% of the amount of charge calculated above. The preferable range is 5 to 10 times, more preferably 2 to 5 times. If the reduction treatment exceeds these upper limits and is excessively reduced, the characteristics of the ECD element may deteriorate, and if the reduction is below the lower limit, sufficient effects may not be obtained.

As described above, in the present invention, when constructing an ECD element, the coloring layer is previously subjected to a reduction treatment, but most of the coloring layer subjected to the reduction treatment is in an extremely low oxidation state, that is, Since it is reduced and in an unstable state, it tends to be re-oxidized when left in the air. Therefore, after performing the reduction treatment, it is preferable to take measures such as constructing the K ECD element immediately or storing it in an anaerobic atmosphere.

(Action and Effect) ECD obtained by adopting the composition method of the present invention
The element has a larger ΔCDj5 even when driven with the same voltage.
E is obtained, and the response speed is improved. E at even lower voltage
In addition to being able to drive the CD element and improving its lifespan, it is also possible to use type 0E, which has an oxidized coloring layer and a reduced coloring layer facing each other.
In a CD element, the transmittance when decoloring is improved.

The reason why such an effect is obtained is not clear, but the inventor of the present invention conjectures as follows. That is, it is said that the coloring and fading of the ECD element is caused by ions being implanted into or extracted from the coloring layer. Therefore, for example, in order to inject ions into the coloring layer from the electrolyte layer, ions must be transferred in and out between the counter electrode and the electrolyte layer in order to maintain charge neutrality, and vice versa. Even when ions are released into the electrolyte, the ions must be transferred in and out between the counter electrode and the electrolyte layer. At this time, if there are not many ions that can be taken in and out of both the coloring layer and the counter electrode, the degree of coloring and decoloring will be small, but a sufficient amount can be created in the coloring layer and the counter electrode by reduction treatment. If such ions can be present, the exchange of ions between the coloring layer and the counter electrode will be smooth, and
It is expected that improvements in characteristics such as an increase in ΔOD will occur because a sufficient amount of ions can be exchanged. The ion that brings about this effect is not limited to hydrogen ion H''K, but other ions that have the same function as hydrogen ion are also expected to have similar effects.For example, in electrical reduction treatment, lithium perchlorate, perchlorate When an electrolyte containing sodium or potassium perchlorate dissolved in an organic solvent is used as an electrolyte solution, Li" + Na" + and + are considered to replace H+, respectively.

Furthermore, in some cases, -valent anions such as OH- are extracted, and the same effect as when monovalent cations are injected may be produced.

It is assumed that anion abstraction occurs together with cation injection or alone.

Furthermore, compared to the conventional A-SONG method, the notable difference is that in the case of the present invention, bubbles do not occur as in A-SONG, and there is no deterioration or deterioration of the display quality of the ECD element. . As mentioned above, this seems to be due to the fact that water decomposition, which causes bubbles, does not occur in the present invention.

Furthermore, the display memory function of the ECD element can be improved. The reason for this is that the ECD that performed the A song
In the device, the oxygen generated by A-SONG is dissolved in the electrolyte, and this oxygen becomes a reductant that reoxidizes the colored or discolored coloring layer material, which is thought to be the cause of poor memory performance. On the other hand, in an ECD element in which the coloring layer is subjected to reduction treatment as a pre-treatment, 02 is almost never generated due to water decomposition as in A-SONG treatment.
Furthermore, it is considered that the memory property can be further improved by lowering the amount of dissolved oxygen in the electrolyte in advance.

In addition, in the case of ASONG, it is not necessarily easy to control the degree of improvement in the characteristics of the ECD element, but the electrical reduction treatment in the present invention makes it easy to control the amount of reduction, which is closely related to the degree of improvement in the characteristics of the ECD element. The chemical reduction treatment also has the advantage that it is easy to treat a plurality of color-forming layers or a large amount of color-forming layers or counter electrodes at once.

Examples and comparative examples will be given below to further specifically demonstrate the effects of the present invention.

Note that the characteristics of the ECD elements in the following Examples and the like were evaluated by the following method.

When only one coloring layer is used, a coloring layer is used as the counter electrode. A porous alumina plate was inserted between the two layers as a white background plate. An aqueous 1N-H2SO4 solution was used as the electrolyte layer.

Furthermore, when two coloring layers were used, an alumina substrate was used as the substrate for one of the coloring layers.

(1) ΔOD Difference in the degree of light absorption during coloring and decolorization, that is, difference in optical density between coloring and decolorization ΔOD = −tag
The evaluation of IC/III (where Ic+IB is the intensity of reflected light when colored and when decolored, respectively) is the change in reflectance when the ECD element is driven with a square wave with a period of 4 seconds and an amplitude of ±0.5V. Changes in reflectance were investigated by using a halogen lamp as a light source, measuring the intensity of reflected light with a photomultiplier corrected for visibility, and recording it with a transient recorder.

(2) Response speed When switching from decoloring to coloring, evaluation was made based on the time from decoloring to coloring by 0.5 in ΔOD.

(3 memory characteristics When the ECD element is driven at ±0.5v, the ECD element is brought into an open circuit state in the maximum colored state, and the attenuation rate of ΔOD is 5
Evaluation was made based on the time taken to exceed %. However, at the beginning of changing the period of the drive waveform, ΔOD is not stable, so it varies from several tens to
The measurement was started at the time when ΔOD became stable after several hundred repetitions.

(4) Life characteristics The ECD element was evaluated by the number of repetitions until ΔOD exceeded ±10% of the initial value when the ECD element was driven with a square wave having a period of 1 second and an amplitude of ±0.5V.

Example 1 Tungsten oxide was vapor-deposited by resistance heating in the air on a glass substrate with ITO to form a film layer with a thickness of 3000×, which was used as a coloring layer. This coloring layer was I
Reduction treatment was performed by constant potential electrolysis using a Tendiostat. The potential of the coloring layer is kAgC! - With respect to the reference electrode, it was set to -o, osv, and electrolysis was stopped at the point where no current flowed, and the ECD element was quickly washed and dried, and then the ECD element was assembled and its characteristics were evaluated. As a result, ΔOD: 0.73, response time: 130 milliseconds, memory characteristics were good for more than 3 hours, and life characteristics showed that the change in ΔOD was still ±10% of the initial value after 3×10 cycles. It was within

Further, during the measurement of life characteristics, no bubbles were observed and the display was clear.

Example 2 The same conditions as in Example 1 were carried out except that the reduction treatment was carried out by constant current electrolysis using a galvanostat. Electrolysis was performed for 400 seconds at a set current value of 50 μA/crn.

The results showed that ΔOD: 0.66, response speed of 140 milliseconds, memory characteristics, life characteristics, no bubbles, and display clarity were almost as good as in Example 1.

Example 3 The same conditions as in Example 2 were carried out except that the reduction treatment was carried out by constant current electrolysis in an aqueous solution of 1N-HNO.

The result is ΔOD: 0.69. Response speed: 140 milliseconds, life characteristics: 4×10′ times, and other aspects were almost the same as in Example 1.

Example 4 The same conditions as in Example 1 were carried out except that the reduction treatment was carried out for 10 minutes in a 1 molti L-ascorbic acid aqueous solution.

The result is ΔOD: 0.63. Response time: 165 milliseconds; Life characteristics: 2X10'Others are the same as Example 1'
were similar.

Example 5 Iridium oxide was formed into a film layer with a thickness of 51,000X by using high-frequency reactive foam in an elemental atmosphere on a glass substrate with ITO, and this was used as a coloring layer. Further, the potential of the coloring layer was set to +0.2V with respect to the reference electrode.

Other than these conditions, the same conditions as in Example 1 were used.

The results are ΔOD: 0.59, response time: 80
The life characteristics were 5×10' times in milliseconds, and the other characteristics were the same as in Example 1.

were similar.

Example 6 A coloring layer of iridium oxide film similar to Example 5 was prepared in Example 2.
The reduction treatment was carried out by constant current electrolysis under the same conditions as described above. Electrolysis was performed for 800 seconds at a set current value of 50 μA/cm.

The result is Δ00: 0.61, response time; 75
Milliseconds, life characteristics: 6 x 10' times.

Example 7 I N -KCt in place of 1 N -H2So4 aqueous solution
The same conditions as in Example 6 were used except that an aqueous solution was used.

The result is ΔOD: 0.60. Response time: 80 milliseconds, life characteristics: 6 x 10' times.

Example 8 A coloring layer of the same iridium oxide film as in Example 5 was prepared at 1 M
The process was carried out under the same conditions as in Example 5, except that the chemical reduction treatment was carried out in an aqueous solution of -NaBH4.

The results are ΔOD: 0.64, response speed: 70 ms,
The life characteristics were 5 x 10 times.

Example 9 A coloring layer was formed in the same manner as in Example 1, and in the same manner as in Example 5, an iridium oxide film layer having a thickness of 500× was formed on a white alumina substrate with ITO to obtain a coloring layer. Of these, only the coloring layer of the tungsten oxide film was reduced under the same conditions as in Example 2, and the two coloring layers were made to face each other.
An ECD element was assembled and its characteristics were investigated.

As a result, ΔOD; 0.68, response speed; 150
Milliseconds, life characteristics: 2 x 10' times, reflectance when decolored is 8
The other parts were almost the same as in Example 1.

Example 10 Of the two coloring layers obtained in the same manner as in Example 9, only the coloring layer of the iridium oxide film was heated to 50% by the same method as in Example 6.
The reduction treatment was carried out by constant current electrolysis at 2 μA/2 for 700 seconds. An ECD element was assembled in the same manner as in Example 9, and its characteristics were investigated.

The results were as follows: ΔOD: 0.74, response speed: 120 milliseconds, life characteristics: 5×10' times, and reflectance when decolored was 86 cm.

Example 11 Of the two coloring layers obtained in the same manner as in Example 9, the coloring layer of the tungsten oxide film was 50 μA in the same manner as in Example 9.
/an2 for 200 seconds, and the coloring layer of the iridium oxide film was reduced by constant current electrolysis in the same manner as in Example 10 for 70 seconds. An ECD element was assembled in the same manner as in Example 9, and its characteristics were investigated.

The results were as follows: ΔOD: 0.79, response speed: 110 milliseconds, life characteristic 7×10' times, and reflectance upon decolorization reaching 89 inches.

The rest was almost the same as in Example 1.

Example 12 A film layer of molybdenum oxide with a thickness of 4000× was formed on an ITO glass substrate using reactive vines, and this was used as a coloring layer.

Other conditions were the same as in Example 2.

The results were: ΔoD: 56, response speed: 500 milliseconds, and life characteristics: 5×10'.

Example 13 Sputtered iridium film was used as a coloring layer in IN-H2S
Using iridium hydroxide obtained by anodic oxidation in O4, the coloring layer was reduced in the same manner as in Example 5, and then a KECD element was assembled.

The results are ΔOD: 0.65, response speed: 70 ms,
Life characteristics: 4 x I 95 times.

Example 14 The same conditions as in Example 2 were carried out except that ion implantation was performed in a propylene cargenate solution containing 1 mol L i C1O4. However, a propylene carbinate solution containing 1 mol LiC2O4 was also used as the electrolyte solution when assembling the ECD element. As a result, ΔoD; 0.65,
Response speed: 140 milliseconds, life characteristics: 5×10 cycles, and other aspects were almost the same as in Example 1.

Example 15 A tungsten oxide film coloring layer was used as the coloring layer, and only the counter electrode was chemically reduced in the same manner as in Example 4.
Assembled the CD element.

The result is ΔOD: 0.71. Response time: 135 milliseconds, life characteristics: 3×10' times, and other aspects were almost the same as in Example 1.

Example 16 The same procedure as in Example 15 was carried out except that both the coloring layer and the counter electrode were subjected to the reduction treatment.

The result is ΔOD: 0.75, response time: 13
0 millisecond, life characteristics: 6 x 10' times, and other aspects were almost the same as in Example 1.

Comparative Example 1 An ECD element was assembled in the same manner as in Example 1 without being subjected to reduction treatment, and its characteristics were investigated. When we first investigated its characteristics without aging, we found that in the initial stage, ΔO
D was only about 0.2, but ΔOD gradually increased and by the 1000th repetition, ΔOD reached 0.
4, and ΔOD remained unstable even after that.

After this 0ECD element was further aged 500 times at ±0.8 V, ΔOD increased to 0.62 when driven at ±0, SV, which is the evaluation standard. After this, ±0.5V
Even after driving 1000 times, the change in ΔOD was extremely small. Further, the response speed was 135 milliseconds, which was almost the same value as in Example 1. However, when examining the memory characteristics of this ECD element, it was approximately 20 minutes, indicating extremely poor memory characteristics. In addition, the life characteristics are not good after about 8 x 10' cycles, and moreover, if the cycle exceeds 2 x 10 times, bubbles will be generated in the electrolyte layer, and if it exceeds 5 x 10 cycles, countless bubbles will be generated. Color unevenness also increased, and the display quality deteriorated significantly.

Comparative Example 2 An ECD element was assembled in the same manner as in Example 6 without being subjected to reduction treatment, and its characteristics were investigated.

As a result, as in Comparative Example 1, ΔOD was small and unstable before Aison. Furthermore, 500 at ±0.8V
After aging twice, a ΔOD of 0.51 was obtained, but the memory property was poor as in Comparative Example 1, lasting less than 30 minutes.

Moreover, the life characteristics were 4×10 times, and when the number of times exceeded 10 times, the amount of bubbles generated increased and other characteristics were also extremely deteriorated.

Comparative Example 3 EC similar to Example 11 without reducing the coloring layer
I assembled a D element and learned its characteristics.

As a result, the initial ΔOD was about 0.2 before Aison, but after 1000 times it reached 0.45. Next, after performing an aging process 500 times at ±0.8V, the characteristics were measured and a ΔOD of 0.70 and a response speed of 125 milliseconds were obtained, but the memory performance was extremely poor at just under 20 minutes. In addition, the lifetime characteristics were 8×10 times, and as compared to 1×105 times, the occurrence of bubbles was more frequent, and the deterioration of the element quality was significant.

Claims (11)

[Claims] (1) A method for configuring an electrochromic display element, characterized in that, when configuring the electrochromic display element, at least one of the coloring layer and its counter electrode is subjected to a reduction treatment in advance before configuring the electrochromic display element. (2) When the color-forming layer is composed of a plurality of color-forming layers, the composition method according to claim 1, wherein at least one color-forming layer is subjected to a reduction treatment. (3) The method of construction according to claim 1, in which the reduction treatment is performed by applying a voltage in an electrolyte solution using the coloring layer or the counter electrode as a cathode with respect to a counter electrode during electrolytic reduction. (4) As a method of electrolytic reduction, a coloring layer or a counter electrode is used as a cathode with respect to a counter electrode during electrolytic reduction, and electrolysis is carried out while maintaining the potential of the cathode at a constant potential with respect to a reference electrode. Construction method described in Section 3 (5) As a method of electrolytic reduction, the color forming layer or the counter electrode is used as a cathode, and electrolysis is carried out while keeping the current flowing through the cathode constant. (6) As the electrolyte solution, electrolyte inorganic acid aqueous solution such as sulfuric acid, hydrochloric acid, nitric acid; aqueous solution containing electrolyte such as sodium sulfate, sodium chloride, potassium chloride; electrolyte alkaline aqueous solution or supernatant such as sodium hydroxide, potassium hydroxide, ammonia. The composition according to claim 3, which uses an organic solution such as propylene carbonate, γ-butyrolactone, acetonitrile, etc. containing an electrolyte such as chloric acid, lithium perchlorate, sodium perchlorate, potassium perchlorate, etc. law (7) The method of construction according to claim 1, wherein the reduction treatment method involves reducing the coloring layer or its counter electrode in a solution containing a reducing agent. (8) As a reducing agent, sodium borohydride, ferrous chloride, potassium ferrocyanide, L-ascorbic acid,
Claim 7 using a reducing agent such as hydroquinone, hydrazine, hydrogen iodide, hydrogen sulfide, formic acid, oxalic acid, etc.
Configuration method described in section (9) Claims in which the ion species injected into the coloring layer during the reduction treatment are monovalent cations such as H^+, Li^+, Na^+, K^+, Ag^+, etc. Construction method described in paragraph 1 (10) The composition method according to claim 1, wherein the ionic species extracted from the coloring layer during the reduction treatment is a monovalent anion such as OH^-. (11) The coloring layer is an inorganic material such as tungsten oxide, molybdenum oxide, titanium oxide, vanadium oxide, chromium oxide, iridium oxide, iridium hydroxide, nickel hydroxide, rhodium hydroxide, niobium oxide or viologen,
The composition method according to claim 1, which is made of organic materials such as rare earth diphthalocyanine, TTF polystyrene, and viologen polymer.