JPS6315229A - Electrochromic element - Google Patents

Abstract

PURPOSE:To enable application of a production process which does not use a vacuum system and is excellent in mass productivity and to permit easy production of a thick EC layer as well by using a chlorine compd. of tungsten as a raw material and adding an org. carbonyl compd. and org. carboxylic acid compd. thereto, then supplying the compd. onto a substrate and subjecting the same to thermal decomposition. CONSTITUTION:The tungsten oxide layer is formed by bringing the chlorine compd. of the tungsten into reaction with an org. acid, then bringing the same into reaction with an org. solvent to synthesize an org. compd. of the tungsten, adding the org. carbonyl compd. and org. carboxylic acid compd. of <=20C thereto, supplying the compd. into an electrode and heating the same. The production process for production which does not use the vacuum system and is excellent in mass productivity is applicable to form the above-mentioned EC layer. The thick EC layer is thus easily produced and since the layer does not contain HCl and Cl, the dissolution of the transparent conductive film is obviated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to an electrochromic device in which a tungsten oxide layer is formed without using a vacuum system such as vapor deposition.

[Prior art] An electrochromic (hereinafter abbreviated as "EC") element is
Usually, the surface is coated with a tin oxide coating or a tin oxide-indium oxide (1-0) coating 115! An EC material layer such as tungsten oxide or molybdenum oxide is formed on a substrate such as glass or plastic on which a transparent conductive film such as or a metal coating such as aluminum, gold, copper, etc. is formed as an electrode, and the EC material layer is formed. It is constructed by inserting an electrolyte layer between an electrode substrate and another opposing electrode substrate.

Brewed tungsten is widely used as an EC material, and is usually formed in the form of a film on an electrode substrate by vacuum deposition. However, in order to achieve deeper coloring and extend the coloring/decoloring cycle life, the EC material film must be thicker, and if the film is formed by vacuum evaporation, the deposition time must be longer. This was a factor that increased manufacturing costs.

On the other hand, after applying a solution of a tungsten organic compound dissolved in an organic solvent onto a glass substrate having a transparent electrode. There is a method of heating and thermally decomposing it to form a tungsten oxide layer (#+j 1983-38379), or a method of applying a transition metal compound solution such as an alcoholic solution of tungsten chloride onto the electrode substrate and drying it. How to form layers (
JP-A-55-11207) has also been reported.

[Problem to be Solved by the Invention 1] In the conventional method for forming a tungsten oxide film described above, forming a thick tungsten oxide film by vacuum evaporation has poor productivity and high cost. Therefore, it was not suitable for large EC equipment. Fine control of film density was difficult.

Furthermore, the method described above is known as a method suitable for mass production without using a vacuum device.

However, when a tungsten compound solution is applied onto a glass substrate and then heated to form a tungsten oxide layer, the heating temperature is important. When the heating temperature is low, the formed tungsten oxide layer becomes very porous and has a fast coloring/decoloring response, but lacks adhesion to the substrate and has a short coloring/decoloring cycle life.

On the other hand, when the heating temperature is high, although the adhesion to the substrate is good, the tungsten oxide layer becomes dense and the coloring/decoloring response becomes slow.

The present invention was made to eliminate the drawbacks of the conventional tungsten oxide film formation method, and when used as an EC device, it has excellent response characteristics and stability due to multiple coloring and decoloring operations. It is an object of the present invention to provide a method for forming a tungsten oxide film that can form a tungsten oxide film with a tungsten oxide film.

[Means for solving the problem] The present invention includes a first substrate with an electrode on which a tungsten oxide layer as an EC material is formed on one surface, and a second substrate with an electrode, which are arranged so that the electrode surfaces face each other. In an EC device in which an electrolyte is arranged between the tungsten oxide layer and the tungsten oxide layer, a tungsten chlorine compound is reacted with an organic acid, and then reacted with an organic solvent containing a hydroxyl group to synthesize an organic tungsten compound. , an EC element characterized in that it is formed by adding an organic carbonyl compound or an organic carboxylic acid compound having 20 or less carbon atoms, supplying the tungsten organic compound onto an electrode, and heating the tungsten organic compound.

The EC layer of the present invention can be manufactured by using a chlorine-based compound in tungsten as a raw material, supplying it onto a substrate, and thermally decomposing it, which is excellent in mass production without using a vacuum system.
Thick EC layers can be manufactured easily and with high productivity, and even the EC layers formed in this way do not become strongly acidic because they contain almost no HCl or AT, and dissolve the underlying transparent conductive film. Never.

In addition, since no acid remains in the generated tungsten oxide film, it does not have a negative effect on coloring and fading, and has a long cycle life.The density of the tungsten oxide film can be controlled by the amount of organic compounds added, and the responsiveness , an EC layer with excellent durability can be obtained.

The present invention is to interact with tungsten by adding an organic carbonyl compound or an organic carboxylic acid compound to suppress densification of the WO3 film during heating. Among organic carbonyl compounds and organic carboxylic acid compounds, diketones,
Preference is given to ketoesters and dicarboxylic acids, which are
This is because the two C=0 atoms present in these molecules coordinate with the tungsten atom to form a type of chain.

Examples of the specific M include diketones such as acetonylacetone, benzoylacetylacetone, benzoyltrifluoroacetylacetone, and t-butylacetylacetone;
Ketoesters such as methyl acetoacetate, ethyl acetoacetate, phenyl acetoacetate, methyl propionyl acetate, methyl acetopropionate, carboxylic acids such as acetone dicarboxylic acid, diethyl acetone dicarboxylate, dimethyl succinate, oxalic acid, diethyl oxalate, etc. be.

Also, the solubility in alcohol, WO prepared by heating
3. From the viewpoint of coloring/decoloring properties of the film, the number of carbon atoms is preferably 20 or less.

If the carbon number exceeds 20, the solubility will be low, the boiling point will be high, and even after firing, the carbon number will tend to remain in the tungsten oxide film and deteriorate the EC characteristics, so the carbon number is set to 20 or less.

F, N, S atoms, C-C, -NO3 as long as they do not interfere with the solubility and coloring/decoloring properties of the above organic compounds.
It can also be used even if it contains a functional group such as a group or an -OH group.

The amount added is preferably 0.3 to 10 times the molar ratio of tungsten, especially 0.5 to B times, and less than 0.3 times,
This is because the effect of addition is small, and if the amount is 1θ or more, the adhesion force with the substrate decreases.

In the present invention, a chlorine-based compound of tungsten is dissolved in an organic solvent, and this is reacted with an organic acid to produce an organic acid salt of tungsten, which is further reacted with an organic solvent containing a hydroxy group to produce W( An organic compound of tungsten, which is tungsten alkoxide or tungsten phenoxide, represented by OR) It is supplied and fired to produce tungsten oxide.

Methods for supplying this tungsten organic compound onto the electrode include dipping the substrate in a tungsten organic compound solution and then pulling it up to coat it, spin-coating or spray coating the tungsten organic compound solution, or printing. Any well-known supply method can be used.

Next, the supplied organic compound of tungsten is fired to form tungsten oxide. This firing temperature is sufficient as long as the organic compound of tungsten becomes tungsten oxide, and
Desirably 0℃ or higher and 350℃ or lower, because 50℃
This is because at lower temperatures, crystals form on the tungsten oxide film and patterns appear on the film surface.
This is because if the tungsten oxide film is fired at a higher temperature, the entire tungsten oxide film becomes crystalline, and when used as an EC device, the tungsten oxide film becomes discolored and the response time becomes slower. The temperature may be about 100 to 300°C.

The first electrode-attached substrate used in the present invention is a substrate made of glass, plastic, or the like. ,5n0
A second electrode is formed, and a tungsten oxide layer as an EC material is formed on the electrode.The second electrode-attached substrate has a counter electrode formed on a glass, plastic, etc. substrate. . At least one of the first electrode-attached substrate and the second electrode-attached substrate is a transparent substrate, and the electrode formed thereon is also a transparent TL pole. Furthermore, in the case of a transmissive EC element such as a transmissive ECD or a light control window, both elements are a transparent substrate and a transparent electrode formed on the transparent substrate.

Of course, a part of this transparent electrode contains AI, Ni, Ti,
Leads made of a low resistance metal such as Cu, Ag, or Cr may be formed in a linear shape, a mesh shape, a grid pattern, or the like.

In addition, the electrode of the electrode-attached substrate on which this tungsten oxide layer is formed may be used by patterning it into a desired shape in the case of ECD, and it is usually used as a solid electrode on the entire surface in the case of light control body. Bye.

In the case of a reflective type EC element such as a reflective ECD with a structure in which a background plate is placed on the counter electrode, the counter electrode is
In a transmissive EC element, which may be a mixture of opaque carbon and EC material, an opaque EC material, or a material that changes color and disappears upon application of a voltage similar to the EC material of the present invention, the counter electrode is transparent or EC material. The EC material of the present invention is a material that changes color and disappears when a voltage is applied in the opposite direction, so that it can be in a transparent state or a colored state. Further, in the case of a specular reflection type such as a dimming mirror, the transmission type EC element and a mirror may be combined, or the electrode on the back side may be made of a material having specular reflection property.

The electrolyte disposed between the first electrode-attached substrate and the second electrode-attached substrate may be any substance capable of coloring or decolorizing the EC substance, such as propylene carbonate, γ-butyrolactone, butyl alcohol, etc. perchlorinated lithium in an organic solvent.

What is necessary is to use a supporting electrolyte such as lithium iodide, and if necessary, further mixed with various additives such as a gelling agent and a dye.

In this way, the first substrate with electrodes and the second substrate with electrodes are arranged so that their electrode surfaces face each other, and the electrolyte is placed between them. In this case, if the electrolyte is a liquid or gel, it is preferable to provide a sealing material around the electrolyte to seal the electrolyte.Of course, a seal may also be formed in the case of a solid electrolyte.

[Example] WCIb or WOC]a was used as a raw material, 0.03 mol of these was dissolved in CC1a 20hQ, and 0.1 mol of RCOOH (R is a C1 to C4 hydrocarbon group) was dissolved.
Then, the solvent was evaporated using a rotary evaporator, and methyl acetoacetate, ethyl acetoacetate, diketones, trifluoroacetylacetone, benzoylacetylacetone, and tartaric acid were added as dicarboxylic acids. These solutions were directly coated on a transparent electrode (ITO) and the density of a tungsten oxide layer was measured by baking at 200°C.

As a result, the density of the tungsten oxide layer to which any of the compounds was added decreased as the amount of the compound added increased.

Among these, the relationship between the concentration of tungsten added and the density of the tungsten oxide layer for examples of methyl acetoacetate, trifluoroacetylacetone, and tartaric acid is shown in FIG.

In addition, these solutions were directly coated on a transparent electrode (ITO) and baked at 200°C to form a tungsten oxide layer.
A substrate with electrodes and a transparent electrode (ITO) as the counter electrode.
The formed second electrode-attached substrate was placed so that the electrode surfaces faced each other, and the periphery was sealed with epoxy resin, and at the same time, polyvinyl butyral was mixed with γ-butyrolactone containing 0.5M/12 Lil. An EC light control body was manufactured by placing the gelled electrolyte thereon, and its coloring/decoloring response was investigated. As a result, the coloring response of the EC dimmers to which any compound was added was almost the same as that of the EC dimmers to which no compound was added, and the decoloring response was significantly faster. Table 1 shows the time required for the transmittance of the system with added methyl acetoacetate to change from 15% to 70%.

Table 1 As can be seen from Table 1, even in the system in which one methyl acetoacetate was added to tungsten, the response speed increased by 40%, and in the system in which six methyl acetoacetates were added, the response speed increased to about 175.

[Effects of the Invention] The EC layer of the present invention uses a tungsten chlorine compound as a raw material, adds an organic carbonyl compound and an organic carboxylic acid compound, and then supplies it onto a substrate and thermally decomposes it, without using a vacuum system. It is possible to apply a manufacturing method that is excellent in mass production, and thick EC layers can be easily manufactured with high productivity, making it extremely productive.

Furthermore, even if an EC layer is formed by using a tungsten chlorine compound as a starting material and heating an organic tungsten compound on an electrode, it will not be strongly acidic because it contains almost no HCI or CI. Since the underlying transparent conductive film is not dissolved, there is no need for a protective coating for the underlying transparent electrode.

Furthermore, since the density of the produced tungsten oxide film can be controlled, an EC layer with excellent responsiveness and durability can be formed.

In addition, the present invention can be applied in various ways, such as forming an antireflection layer on the surface, providing a printed layer, combining with other display elements, adding an automatic light control mechanism, and combining with a mirror. It can be used in various ECD and EC dimming devices.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the relationship between the concentration of an additive and the density of a tungsten oxide layer in an example of the present invention. a: Methyl acetoacetate b = Nitrifluoroacetylacetone: Tartaric acid

Claims (6)

[Claims] (1) A first substrate with an electrode on which a tungsten oxide layer as an electrochromic substance is formed and a second substrate with an electrode are arranged so that the electrode surfaces face each other, and an electrolyte is arranged between them. In the electrochromic device, the tungsten oxide layer reacts the chlorine-based compound of tungsten with an organic acid, and then reacts it with an organic solvent containing a hydroxy group to synthesize an organic compound of tungsten. 1. An electrochromic device, characterized in that it is formed by adding a compound or an organic carboxylic acid compound, supplying the organic compound of tungsten onto an electrode, and heating it. (2) The electrochromic device according to claim 1, in which a chlorine-based compound of tungsten is dissolved in an organic solvent and reacted in a dehydrated state. (3) The electrochromic device according to claim 1, wherein the organic acid is a carboxylic acid having 1 to 4 carbon atoms. (4) The electrochromic device according to claim 1, wherein the organic solvent containing a hydroxy group is an alcohol. (5) The electrochromic device according to claim 4, wherein the alcohol is isopropyl alcohol. (6) The amount of organic carbonyl compound or organic carboxylic acid compound added is 0.3 to 10% relative to the concentration of tungsten.
The electrochromic device according to claim 1, which is twice as large.