JPS58207029A - All solid-state type electrochromic display - Google Patents

Abstract

PURPOSE:To produce a titled EC display which is fast in response, permits multi- color display, has high resistance to environment and has a long life by using prescribed polymer films in forming the constituting layers of the display except the transparent electrode, display electrode and counter electrode thereof. CONSTITUTION:A colored active material layer is formed of the film of a polymer (e.g; acrylic resin, fluororesin) containing (A) an organic EC material (e.g; viologen, diphthalocyanine) incorporated therein, (B) an ion donating and accepting material (e.g; lead halide, pyridine halide) and (C) a cross-linking material (e.g.; the compds. expressed by the formula I , the formula II) incorporated therein. More specifically, a transparent display elctrode (e.g.; tin oxide film) 2 is provided on a transparent substrate (e.g.; glass plate) 1 and further the above-described colored active material layer 7 and counter electrode 5 are provided thereon, whereby the EC display is produced (a symbol 6 is a sealing layer using an epoxy resin or the like). Since the above-mentioned display has the colored active material layer which is three-dimensionally crosslinked by the crosslinking agent, the device has particularly high resistance to environment.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrochromic display device (hereinafter referred to as ECD).
), especially all-solid-state EO
This is related to D.

EOD is a substance that is easily oxidized or reduced when electricity is applied, and that causes a large change in the absorption spectrum in the visible region (hereinafter, such substances are called electrochromic materials, abbreviated as EC materials). ) ONO materials, which refer to display devices using ONO materials as display materials, can be roughly divided into two types: inorganic materials and organic materials (this includes organic metal materials). To give typical examples of these, inorganic materials are oxidized transition metal compounds, and organic materials are aromatic and heterocyclic compounds, or coordination compounds of these compounds and transition metals (i.e., organometallic materials). be. Furthermore, organic materials can produce a wider variety of colors than inorganic materials. It is excellent in that respect.

In addition to the above-mentioned EC materials, ECDs basically consist of an electrolyte, a display electrode, and a counter electrode.Due to their structure, ECDs can be of the liquid type, which uses a liquid (i.e., electrolyte) as the electrolyte, or the all-solid type, which uses a solid electrolyte. It is roughly divided into two types. Most of the nine EODs announced so far have a liquid type structure, but liquid types always have the risk of leakage due to thermal expansion of the electrolyte, and when liquid leaks, it may damage other electronic components. There is a risk of causing damage to the person. Further, it is not possible to omit the process of constructing a cell that can be sealed with an electrolytic solution and injecting the electrolytic solution into the cell, which requires a large number of steps.

All-solid-state BCDs that use a solid electrolyte have no risk of liquid leakage, can reduce the number of man-hours during manufacturing, and are superior in that they can solidify electronic components, but their performance is still limited. Not enough has been done. Conventional all-solid type E
An example of the basic structure of OD is shown in FIG. On this line transparent substrate 1, a transparent display electrode 2, an electrochromic layer (hereinafter referred to as EC layer) 3, a solid electrolyte layer 4, and a counter electrode 5
, a sealing layer 6 is formed in sequence. This conventional I
In the C0D structure, an inorganic EC material such as a tungsten oxide thin film is used for the 10 layer 3, and an 8 layer is used for the solid electrolyte layer.
i0. OaF: , λIgF, % insulation or L
Li+, Na'' ion conductive materials such as i s N and β-AJ20 s are used.IODs with this structure have the following drawbacks due to the 10 layers and solid electrolyte layer. Firstly, because the 10th layer uses an inorganic FiC material, the display color is limited to deep blue, making it difficult to provide a variety of displays.Secondly, the solid electrolyte layer In a type of ICD using an insulating material, 10
Since the oxidation-reduction of the material is caused by the moisture adsorbed in the insulation material, the characteristics of EOD are strongly affected by the surrounding environment, especially humidity, and bubbles are also generated due to the decomposition of water.
Significant lack of reliability. In addition, in a type of EOD that uses a Li+ or Na+ ion conductive material for the solid electrolyte layer,
Due to the low mobility of ions, it has drawbacks such as slow response, insufficient adhesion at the interface between the EC layer or electrode and the solid electrolyte layer, and reactions tend to occur at the interface, resulting in a short period of time. ing.

Furthermore, as shown in FIG. 2, as an EOD having the same structure as the ECD according to the present invention (a colored active material layer is used in place of the 10 layers 3 and electrolytic layer 4 in FIG. 1), a colored active material layer 7
phosphotungstic acid n,po,・(WO,),2・n
Nine EODs using H,0 (hereinafter abbreviated as PWA) are known, but these (1) can only produce blue color. That is, there is no possibility of multicoloring. (2) Since the water contained in PWA is involved in coloring and decoloring, the performance of 10D is easily influenced by the surrounding environment, and it also deteriorates quickly. (3) In the case of PWM, the contact with the electrode is the main cause of variation in characteristics and initial deterioration. It has the following drawbacks. Therefore, the 11OD using PWA is not a practical device, and even if it could be put into practical use, it would be expensive. Here, the difference between the EC layer and the colored active material layer will be described. In conventional EOD, as mentioned above, the EC layer is in contact with the electrolytic solution or the solid electrolyte, and the exchange of ions between the two causes coloring and decoloring of the 10 layers, but in the structure shown in Figure 2, Since the colored active material layer contains an EC material and an ion exchange material, coloring and decoloring of the colored active material layer occurs due to the exchange of ions in the colored active material layer.

Many types of organic EC materials (hereinafter abbreviated as organic EC materials) have been discovered by replacing their terminal groups with various functional groups, and they also come in a variety of display colors. There is such a ff1E.

All of the known structures of nine EODs using electrolytes use electrolytes, and all solid-state ECDs using organic EC materials are not yet known.

An object of the present invention is to provide a low-cost all-solid-state electrochromic display device that has high environmental resistance, long life, and can display multiple colors.

The all-solid-state electrochromic display device of the present invention displays on a transparent substrate! In an all-solid-state W-r electrochromic display device having a structure in which a pole, a colored active material layer, and a facing type are sequentially stacked, the colored active material layer includes at least one type of electrochromic material and one or more types of electrochromic material. The present invention is characterized in that it is a polymer membrane containing a material, one or more types of ion exchange materials, and one or more types of crosslinking materials.

One of the features of this invention is transparent substrate and display! pole, opposite [&
The other layer is made up of polymer layers.

This m-class polymer is limited to some extent in terms of display performance, or if the electrochromic phenomenon of coloring and fading occurs simply by applying a voltage, only the g-forming ability becomes a problem. , almost any polymer can be used.

An example of the basic structure of the ECD of the present invention is shown in FIG. 2, as shown in FIG.
The counter electrodes 5 are sequentially laminated, and a sealing layer 6 is formed to seal this laminated structure. Each component will be explained in detail below.

A transparent material such as glass or a plastic plate is used for the transparent substrate 1, and the transparent surface display electrode 2 is made of tin oxide (8nO
2) A transparent conductor such as a film or an indium oxide-tin oxide (ITO) film is used. Display electrodes are usually formed by vacuum deposition, but methods such as spraying, OV'D, and precipitation can also be used.

The colored active material layer 7 of the present invention is a polymer film containing one or more types of EC material and one or more types of ion transfer material, and more specifically, the No material and the ion transfer material are dispersed in the polymer film. pancreas (hereinafter referred to as 10-dispersed membrane) or polymeric EC
A membrane or membrane in which an ion exchange material is dispersed in a material (hereinafter referred to as EC polymer).

It is a membrane in which an EC material is dispersed in a polymeric ion exchange material (hereinafter referred to as an ion exchange polymer), or a membrane in which an EC polymer and an ion exchange polymer are mixed. Ion exchange materials are substances that can exchange ions with the EC material mentioned above, and are not only ordinary ion conductive materials or ion conductors, but also have low conductivity and cannot be used as ion conductive materials. It also includes things.

The EC material to be dispersed can be any of the organic EC materials mentioned above and is not particularly unique to the present invention. For example, viologen, tetrathiafulvalene, allylpyrazoline, fluorene.

These include aromatic or heterocyclic compounds such as anthraquinone, pyrylium, pyridium, and methylene blue, and derivatives of solera, and organometallic compounds such as ferroin, 7-erocene, and siphthalodianine.

Ion exchange materials include, for example, lead halides, alkali metal halides, alkaline earth metal halides, rare earth metal halides, alkylammonium halides, solid solutions thereof, or complexes of alkali metal halides with crown ethers. , halogenated pyridine such as 1-n-butylpyridinium iodide, proton conductive materials such as Ugly and its hydrates, ion exchange resins, alkali metal conductive materials such as transition metal oxides, alkali metals, and alkali halides. Metal, alkali metal perchlorate, alkali metal tetrafluoroborate MBF4 (hereinafter M stands for alkali metal), alkali metal fluorophosphate MPFe=L
Alkali metal compounds such as lsN, thiocyanate/acid alkali metal M8ON, and alkali metal trifluoroacetate, MI4
Zn (GaO2) at MsL M-β-alumina, silver decagenide as a chain conductive material, halogenated steel as a damping conductive material, etc. can be used, and a surface active agent etc. can also be used. be able to.

Examples of polymers for dispersing ion exchange materials or FiO materials include melamine resins, silicon resins, xylene resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, polycarbonate resins, cellulose derivative resins, and polyvinyl carboxylic acid. (Sole resin, polyethylene oxide, polypropylene oxide.

Any polymer can be used as long as it functions as a needle medium, such as polyether resins such as polyacrylonitrile, acrylic resins such as polyacrylonitrile, fluorine resins such as polyvinylidene fluoride, etc. , those having highly polar functional groups, such as acrylic resins and fluororesins, are desirable.

Me polymers include l! of organic materials and organometallic materials. i.

Laminated polymers and EC that bond material molecules together with covalent bonds
As the synthetic polymer used for the dispersion membrane, a pendant polymer in which the polymers listed above or their derivatives and an IC material are covalently bonded can be used. In addition, similar to EC polymers, ion transfer polymers include crown ether, etc.
Laminated polymers in which the molecules of ion transfer materials are bonded together by covalent bonds, and pendant polymers in which the polymers and derivatives thereof already listed as synthetic polymers used in 10-dispersion membranes are bonded to ion transfer materials by covalent bonds. can be used.

The colored active material layer 7 contains a crosslinking material in addition to the above-mentioned substances, and this is included in the coating solution for forming the colored active material layer. By creating crosslinks between molecules of chain-like synthetic polymers, the stability, mechanical strength, and adhesion to the substrate of the colored active material layer are increased. As the crosslinking material used in the present invention, many of the crosslinking materials already known in the fields of polymer chemistry, pigment printing, and photoresists can be used, and the structure thereof is X-R-Y or x-4Y. The structure is Here, x, y, and z are functional groups that can react with polymer molecules by the action of light or heat, and as shown in the figure, are functional groups containing oxygen, sulfur, nitrogen, halogen, etc. R
is an organic compound that connects these functional groups, and is primarily a hydrocarbon chain. As thermal and photocrosslinking materials, those having the chemical formula shown below are used (Examples of thermal crosslinking materials).
8 (OHt OHt OJ ) to t) OH3s
o, (OHt )n038G)H3)) OH,=O
H-80, -0H=OH.

) CICjHt O(OH2)nooo CI
) CI Cjoo<CHt ) n000 01
[Example of photocrosslinking material] 4.4'~Diazidochalcone 2.6-di(4'~azidobenzylidene)cyclohexanone 0H.

2.6-di(41-azidobenzylidene)-4-methylcyclohexanone OH 26-di(4'-azidobenzylidene)-1-oxycyclohexanone is known, and bisazide type is often used as a photocrosslinking material.

For the counter electrode 5, any conductive material can be used, such as gold, silver, copper, carbon (including amorphous and black metal), and the above-mentioned transparent electrode.

For the sealing layer 6, any material can be used as long as it has a sealing effect, such as an organic adhesive such as epoxy resin, low melting point glass, and an IC molding material. Further, as shown in FIG. 2, a substrate made of glass, metal, plastic, etc. can be used instead of the sealing layer.

In that case, the material for the sealing layer is one that is unique to the material for the sealing layer.

Although not a basic constituent requirement, the colored active material layer 7 is made of alumina HLTOS or titanium oxide 'I'i0. A white background of 0ECD can be obtained by mixing white fine powders such as Furthermore, if a colored fine powder is used instead of a white fine powder, a colored background can be obtained.

In addition, it is possible to include a plasticizer in the colored active material layer 7. Generally known plasticizers such as esters of phosphoric acid can be used, and propylene carbonate, propylene carbonate, etc.
High dielectric constant compounds such as ethylene carbonate and γ-butyrolactone and organic compounds commonly known as liquid crystals can also be used. Such a plasticizer made it possible to increase the ionic conductivity in the colored active material layer.

In addition, the colored active material layer contains substances that are commonly used as polymeric stabilizers, antioxidants, and ultraviolet absorbers.
! : CD stability could be increased.

Next, the present invention will be explained by examples.

Example 1 As shown in FIG. 2, ITO transparent electrodes were provided as display electrodes 2 on a transparent glass substrate 1 by vacuum evaporation. A colored active material layer 7 was formed on the display electrode 2 based on the following recipe. Tetrathiafulvalene (T'I) is used as an EC material.
'F) 0.1 mol/11 Lithium perchlorate (Li010.) 0.2 mol/〆 as ion transfer material, Folding II
Methylenebisacrylamide 001 mol/1.
A cyclohexanone solution containing 0.75 mol/l of polymethacrylonitrile as a synthetic polymer and an equal weight of alumina Al2O5 as a white fine powder was applied as a colored active material layer coating solution 7 on the display electrode 2 to a film thickness of 1 μm. The colored active material layer 7 was spinner-coated and placed in an oven uniformly heated to 80° C. for 2 hours in an N2 atmosphere to dry completely. (The number of moles of synthetic polymers such as polymethacrylonitrile is expressed in terms of the number of moles of monomer.) This substrate was crosslinked by irradiating ultraviolet light emitted from a mercury lamp with an output of 3 kW.

The element temperature during irradiation was 60 to 70°C. Furthermore, gold 30001 is vacuum-deposited on this colored active material layer 3, and a counter electrode 5 is formed.
And so. Furthermore, by covering the periphery of the above laminated structure with a sealing layer 6 of epoxy resin, a highly reliable ECD could be manufactured.

In the nine EODs manufactured in this way, when a positive voltage was applied to the display electrode 2 with respect to the counter electrode 5, a dark red display appeared, and when a negative voltage was applied, it disappeared. Practically speaking, by applying a voltage of +3V, the white contrast becomes 4:1 in about 150 m5ec, and a red display with high contrast against a white background is obtained, and then by applying a voltage of -3V with the opposite polarity, the white contrast becomes complete in 200 m5ec. The color disappeared. Furthermore f 3 V 150 m5ec.

When a life test was performed by applying a pulse voltage of -3V for 200 msec, no deterioration phenomenon was observed in the colored active material layer 7 and each interface between it and the electrode 2.5 even after 5 x 106 times of coloring and decoloring. Ta.

The ECD according to this example was carried out at a temperature of 30°C and a relative humidity of 100%.
When a life test was conducted under the above-mentioned driving conditions in an atmosphere of

Example 2 As a colored active material layer coating solution, 0.1 mol of butyl anthraquinone-adducted polystyrene/L 0.1 mol of LiCl-crystalline ether polymer M body/
l, di(chloro70vir)-methylammonia OHs
N (OHt OHt C6)t O, 02 mol/l
, using a cyclohegisanone solution containing an equal weight of alumina,
After coating and drying, a device was manufactured in the same manner as in Example 1, except that it was crosslinked by heating at 120° C. for 3 hours.

This rCD is approximately 50m5e with an applied voltage of -2.5v.
At c, a red display with a white contrast of 4:1 is obtained, and +2
．． The color completely disappeared by applying a voltage of 5V and 70m5ec. No deterioration was observed even after coloring and decoloring 106 times in an atmosphere with a temperature of 30°C and a relative humidity of 10%.

In the above examples, only the spinner method was used as a coating method for the polymer layer, but coating using a screen printing method or a doctor blade method using a coating solution with the same composition as in the previous example was also used. However, when an EOD similar to the above example was manufactured, the same performance was obtained. Thus, the performance of the ECD according to the present invention does not depend on the polymeric coach ink method, and any coating method can be used to fabricate the EOD.

The all-solid-state EOD of the present invention has no risk of liquid leakage.
Liquid type EC is easy to make thin and has low manufacturing cost.
It is a matter of course that it is superior to D, and it is also superior to conventional all-solid-state RODs in the following respects. (1) In the EOD of the present invention, a polymer is used for both the electrochromic layer and the solid electrolyte layer. F of the present invention is protected from the surrounding environment, especially moisture, because the material and the ion exchange material are protected from the surrounding environment, especially moisture.
iOD has a long life and high environmental resistance. (2) Since polymer is a material suitable for mass production, it can be manufactured with high productivity, and therefore it is possible to provide [D] at a low price. (3) Any material that can be dispersed in a polymer can be used as an electrochromic material, so various nighttime displays are possible. (4) Since the colored active material layer is three-dimensionally crosslinked with a crosslinking material, the coloring/decoloring life and environmental resistance can be improved.

1:, , 1 Due to the above various factors, the present invention has been able to provide a practical EOD with a long life and quick response.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a conventional all-solid-state EOD, and FIG. 2 is a cross-sectional view of an all-solid-state EOD obtained by the present invention.
It is a sectional view showing an example of D. In the figure, 1. Transparent substrate, 25 display electrodes, 3. Electrochromic layer, 4. solid electrolyte layer, 5, counter electrode,
6. Seal layer, 7. YK Colored Materials Layer - Hitoben Danshi Uchihara!

Claims (1)

[Claims] In an all-solid-state electrochromic display device having a structure in which a display electrode, a colored active material layer, and a counter electrode are sequentially laminated on a transparent substrate, the colored active material layer includes at least one type of electrochromic material and one or more types of electrochromic material. Ion transfer material and 1
An all-solid-state electrochromic display device characterized by being a polymer film containing at least one crosslinking material.