JP3385883B2 - Electrochromic device and method for manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochromic device having an excellent pattern definition and applicable to various display devices, and an electrochromic device capable of manufacturing the electrochromic device in a simple and inexpensive process. The present invention relates to a method for manufacturing a chromic device.

[0002]

BACKGROUND OF THE INVENTION Electrochromism is a phenomenon in which absorption of light by a substance is changed by electrochemical redox upon application of a current or an electric field, resulting in reversible coloring or color change. Say. A substance that gives such a phenomenon is called an electrochromic substance, and a material that can electrochemically control this change is an electrochromic device.

As this electrochromic substance,
Currently, tungsten oxide is widely used. This tungsten oxide changes from colorless to blue by reduction.
When this tungsten oxide is formed as a thin film on a transparent electrode and applied to glass, electrochromic glass (light control glass) can be obtained in which the light transmittance of glass can be arbitrarily controlled by voltage operation. By using a reflective material such as aluminum as the counter electrode, an antiglare mirror whose reflectance can be switched by voltage operation can be obtained.

Such an electrochromic device is
It has been researched for a long time because it has a memory property for display, low power consumption, no viewing angle dependence, and is suitable for large area display.

However, an electrochromic element having a conventional transparent electrode, an electrochromic film, an electrolyte, and a laminated structure of a counter electrode, especially for an element requiring a display pattern, is formed after the electrochromic film is formed on the transparent electrode. A resist layer having photoreactivity is formed on the resist layer, and the resist layer is irradiated with light through a photomask on which a desired pattern is formed, and the exposed portion (or non-exposed portion) of the resist layer and the electrochromic layer thereunder are exposed. By patterning the electrochromic layer by dissolving and removing the layer with an appropriate solvent, further removing the remaining resist layer, and then laminating the counter electrode via the electrolyte layer, a very complicated process for its production. I needed it. Further, the electrochromic pattern thus prepared has a problem that it lacks stability due to peeling or melting from the transparent electrode over time, and development of an electrochromic device and a manufacturing method thereof without these defects has been desired.

The present invention has been made in view of the above circumstances, and provides an electrochromic element having an excellent pattern definition and a method for manufacturing the electrochromic element, which can easily and inexpensively manufacture the electrochromic element. The purpose is to

[0007]

Means for Solving the Problems and Modes for Carrying Out the Invention The present inventor has conducted extensive studies to achieve the above object, and as a result, a transparent film on which an electrochromic substance film which is colored by reduction of tungsten oxide is formed. When a polysilane film is laminated on the film on the electrode substrate, and the polysilane film is covered with a mask having a desired pattern and selectively irradiated with light, the polysilane in the exposed portion is converted from Si--Si bonds to Si-- The polysilane in the non-exposed area is converted to an O-bond and is very stable and inert to electrochemical reduction and maintains electrical insulation, while the exposed area is electrically conductive in a solvent in which the supporting electrolyte is dissolved. Therefore, by stacking a counter electrode on the polysilane film selectively irradiated with light through an electrolyte layer, an electrochromic film that develops color by reduction of tungsten oxide or the like. When a voltage is operated between the transparent electrode substrate having a black substance layer and the counter electrode so that the electrochromic substance is reduced, only the electrochromic substance film portion corresponding to the exposed portion of the polysilane film is colored by reduction. To obtain an electrochromic element that does, and finds that this electrochromic element has excellent definition according to the pattern of the polysilane film,
The present invention has been completed.

That is, it has been conventionally known that polysilane can be converted into a conductive polymer by oxidizing it, and researches utilizing such properties of polysilane have been actively conducted. For example, a conductive layer and an insulating layer. Polysilane has been used for the purpose of developing a photoresist for forming a very fine pattern of the above with high precision (JP-A-6-2912).
No. 73). However, this proposal uses polysilane as a conductive layer and a siloxane layer converted from polysilane by light irradiation as an insulating layer, and was an application using polysilane having a Si—Si bond as a conductive material.

In contrast, the present invention utilizes polysilane as an insulating layer and the exposed portion of polysilane as a conductive layer, which is very stable and inert to electrochemical reduction. The electrical insulation is maintained, and the Si-Si bond in the polysilane molecule is easily Si-O by light irradiation.
It is utilized that it has a property of being converted into a —Si bond or a Si—OH bond and exhibiting conductivity in a solvent in which the supporting electrolyte is dissolved by converting the above bond. .

As described above, it is already known that a high molecular compound such as polysilane becomes a conductive polymer when it is oxidized, but polysilane is very stable to electrochemical reduction and retains its insulating property. It has not been noticed that the polysilane shows very good conductivity in a solution containing an electrolyte when it is converted into siloxane or silanol by photooxidation reaction. It is a new finding of the present inventor that an electrochromic device having a can be industrially manufactured advantageously.

Therefore, according to the present invention, (1) a polysilane film patterned by selective light irradiation is laminated on the electrochromic material film of a transparent electrode substrate on which a film of electrochromic material that develops color by reduction is formed. And a counter electrode laminated on the polysilane film via an electrolyte layer, (2) a transparent electrode substrate having a film of an electrochromic substance that develops color by reduction. A method for manufacturing an electrochromic device, which comprises forming a polysilane film on an electrochromic substance film, selectively irradiating the polysilane film with light, and then laminating a counter electrode on the polysilane film via an electrolyte layer. I will provide a.

The present invention will be described in more detail below.
In the electrochromic device of the present invention, as shown in FIG. 1, an electrochromic substance film 2 which is colored by reduction is formed on a transparent electrode substrate 1, and a pattern is formed on the electrochromic substance film 2 by selective light irradiation. Is formed of a polysilane film 3 serving as a conductive layer, and a counter electrode 5 is further formed via an electrolyte layer 4. The electrode substrate 1 and the counter electrode 5 are electrically connected by a power source 6 such that the substrate 1 side is the negative electrode and the counter electrode 5 side is the positive electrode.

Here, as the transparent electrode substrate, a glass substrate, a known transparent substrate such as an epoxy resin, or the like on which a transparent conductive layer of indium tin oxide (ITO), tin oxide, indium oxide or the like is formed is used. Moreover, as the electrochromic substance, tungsten oxide or the like is used, and the one in which an electrochromic layer of tungsten oxide or the like is formed on the transparent conductive layer by a vapor deposition or sputtering method can be used. Typically, a tungsten oxide transparent conductive substrate is used as the transparent electrode substrate having the electrochromic material film.

Further, as the polysilane film, the main chain is made of Si.
Any one having a —Si bond may be used, but one represented by the following general formula (1) can be preferably used.

(R ¹ _m R ² _n X _o Si) _p (1) (wherein R ¹ and R ² are each a hydrogen atom, a substituted or unsubstituted aliphatic, alicyclic or aromatic monovalent carbon) Hydrogen radical,
X is the same group as R ¹ , an alkoxy group or a halogen atom. Further, m, n and o are numbers satisfying 1 ≦ m + n + o ≦ 2, and p is an integer of 10 ≦ p ≦ 100,000. )

In the above formula (1), R ¹ and R ² are each a hydrogen atom, a substituted or unsubstituted aliphatic, alicyclic or aromatic monovalent hydrocarbon group, and an aliphatic or alicyclic hydrocarbon. The group preferably has 1 to 12 carbon atoms, more preferably 1
Are preferably a methyl group, an ethyl group,
Examples thereof include a propyl group, a butyl group, a pentyl group, a hexyl group, a cyclopentyl group and a cyclohexyl group. The aromatic hydrocarbon group preferably has 6 to 6 carbon atoms.
14, more preferably 6 to 10, for example, phenyl group, benzyl group, tolyl group, xylyl group,
Examples thereof include naphthyl group. Examples of the substituted hydrocarbon group include those in which some or all of the hydrogen atoms of the unsubstituted hydrocarbon group exemplified above are substituted with a halogen atom, an alkoxy group, an amino group, an alkylamino group, and the like.
Examples thereof include p-dimethylaminophenyl group and m-dimethylaminophenyl group.

X is the same group as R ¹ , an alkoxy group or a halogen atom, and the alkoxy group is a methoxy group,
Examples of the halogen atom such as an ethoxy group having 1 to 4 carbon atoms include a chlorine atom and a bromine atom, and a chlorine atom, a methoxy group and an ethoxy group are usually used. This X is
It has the effect of preventing peeling of the polysilane film from the substrate and improving the adhesion.

The numbers m, n, o, and p are not particularly limited as long as they are as described above, but more preferably 1.5≤m + n.
+ O ≦ 2, in this case 0.1 ≦ m ≦ 1, especially 0.
5 ≦ m ≦ 1, 0.1 ≦ n ≦ 1, especially 0.5 ≦ n ≦ 1, 0
It is preferable that ≦ o ≦ 0.5, particularly 0 ≦ o ≦ 0.2. Further, p is preferably 10 ≦ p ≦ 10,000.

Further, in the present invention, as the counter electrode,
Any conductive material may be used, and in addition to transparent electrodes such as ITO glass, various metals such as gold, copper and stainless, graphite, and various organic conductive materials can be used.

Further, the electrolyte layer is composed of a solvent containing a supporting electrolyte, and an electrolyte containing a proton or a lithium cation is suitable as the electrolyte, for example, AZ
A salt corresponding to (A = proton or lithium cation, Z = electrochemically inactive, compatible anion, which represents perchlorate, borate, phosphate, sulfonate, etc.) is used. Specific examples include tetramethylammonium perchlorate, lithium perchlorate, tetraethylammonium tetrafluoroborate, lithium tetrafluoroborate and lithium trifluorometasulfonate.

As the solvent, those which are electrochemically inert and dissolve the supporting electrolyte and hardly dissolve the polysilane are preferable. Examples of such a solvent include water,
In addition to alcohols and ethers, propylene carbonate, ethylene carbonate and the like are preferably used. Further, polymers such as polyacrylic acid, polyvinyl alcohol, polyethylene glycol and cyclodextrin can also be preferably used when producing a sealed device.

The electrolyte concentration in the solvent is 0.01 to 1 M /
1 may be used, but usually 0.1 to 0.5 M / l is often used.

When manufacturing the electrochromic device of the present invention, as shown in FIG. 2, after forming the electrochromic substance film 2 of tungsten oxide or the like on the transparent electrode substrate 1, and further forming the polysilane film 3, Polysilane film 3 through a photomask 7 on which a desired pattern is formed
Irradiate light on.

Here, the method for forming the polysilane layer on the tungsten oxide transparent electrode substrate is not particularly limited, and examples thereof include spin coating method, dipping method, casting method, vacuum deposition method, LB method (Langmuir-Brosit method) and the like. Although the usual polysilane thin film forming method can be used, a spin coating method in which a solution of polysilane is formed while rotating at a high speed is particularly preferably used.

In this case, as the solvent for dissolving the polysilane, for example, aromatic hydrocarbons such as benzene, toluene and xylene, and ether solvents such as tetrahydrofuran and dibutyl ether are preferably used. The concentration of the polysilane solution is preferably 1 to 20% by weight, particularly 5 to 15% by weight.

In order to form a polysilane film, it is effective to apply this polysilane solution to a substrate and then leave it in a dry atmosphere for a while or leave it under reduced pressure at a temperature of about 40 to 60 ° C. for drying. Is. As a result, a polysilane thin film having a film thickness of usually 0.01 to 100 μm can be formed on the substrate.

Further, in order to form a pattern on the polysilane film, light such as ultraviolet rays is irradiated from above the polysilane film through a mask on which a desired pattern is formed, whereby light such as ultraviolet rays in the polysilane film is irradiated. Only in the exposed portion 3a hit by Si, the Si-Si bond is converted into Si-O-Si bond or Si-OH bond to form a conductive layer, while in the non-exposed portion, the Si-Si bond of polysilane is maintained. It

The light source may be a continuous spectrum light source such as a hydrogen discharge tube, a rare gas discharge tube, a tungsten lamp or a halogen lamp, or a discontinuous spectrum light source such as various lasers or a mercury lamp, but it is inexpensive and easy to handle. A mercury lamp is preferably used, and a light amount of 0.1 to 100 J / cm ² per 1 μm thickness of polysilane is preferable. This produces a transparent conductive substrate having a film of electrochromic material such as tungsten oxide having a patterned polysilane film. This film can be subjected to heat treatment or the like as necessary so that the film of the silicon-containing polymer is not separated from the electrochromic material film.

After that, the counter electrode 5 is laminated on the polysilane film 3 with the electrolyte layer 4 interposed therebetween. In addition, 8 is a frame for electrolyte retention.

As a stacking method, the substrate 1, the electrochromic material film 2, the polysilane film 3 and the counter electrode 5 are bonded to each other through the frame body 8 using an adhesive such as an epoxy resin,
The electrolyte layer 4 dissolved in a solvent may be introduced later.

The electrochromic device of the present invention is transparent.
When electricity is applied between the bright electrode substrate 1 and the counter electrode 5, polysilane
Electrochromic corresponding to the exposed portion 3a of the film 3
The material film 2a is colored, and the unexposed portion 3b of the polysilane film 3 is exposed.
The corresponding electrochromic material film 2b does not develop color,
Therefore, it corresponds to the selective light irradiation pattern of the polysilane film 3.
A colored pattern is formed. For example, oxidation
In the case of tungsten film, electrochromic material film 2
a (WO₃) Was electrically reduced (WO ₃ ^-)
By doing so, it develops a deep blue color.

That is, when the above-mentioned counter electrode and a transparent electrode made of a tungsten oxide transparent electrode substrate are laminated via an electrolyte layer and a current is applied between both electrodes, a conductive polysiloxane layer in the exposed portion of the polysilane film is formed. When only the tungsten oxide layer in the area where is laminated develops color and the transparent electrode substrate is minus and the counter electrode is plus and voltage is applied through the electrolyte layer, the exposed portion of the polysilane film becomes conductive and the unexposed portion is insulated. The state is maintained, only the tungsten oxide film corresponding to the exposed portion of the polysilane film exhibits a blue color, and when the polarity is reversed, it becomes colorless and transparent.

[0033]

The display device using the polysilane according to the present invention is such that a polysilane thin film is formed on a thin film of an electrochromic substance that develops color upon reduction of tungsten oxide or the like, and a pattern is formed on the thin film of the polysilane to expose the exposed portion. It has a conductive layer formed only on it, has an excellent pattern definition, and can be applied to various display elements such as optical switch elements, optical memory elements, various display panels, and sensors. Further, according to the method of the present invention, the above-mentioned display element can be obtained at a low cost in a simple process, which is industrially very advantageous.

[0034]

EXAMPLES The present invention will be specifically described below by showing synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples.

[Synthesis Example 1] Synthesis of phenylmethylpolysilane 5.06 g (220 mmo) of sodium metal under a nitrogen stream.
1) was added to 60 ml of toluene, and the mixture was heated to 110 ° C. with high speed stirring to disperse it. 19.1 g (100 mmol) of phenylmethyldichlorosilane was slowly added dropwise thereto with stirring. The reaction was completed by stirring for 4 hours until the raw materials disappeared. Then, after cooling, the salt is filtered,
Upon concentration, 10.0 g of polysilane crude product (crude yield 83%) could be obtained.

The obtained polymer was again dissolved in 30 ml of toluene, 120 ml of hexane was added to the solution, and the mixture was precipitated and separated to obtain 6.6 g of phenylmethylpolysilane having a weight average molecular weight of 45,000 (yield 55%). It was

When a film was formed by a spin coating method using the obtained 10% toluene solution of phenylmethylpolysilane polymer, a polymer having a desired film thickness could be obtained.

Example 1 The phenylmethylpolysilane produced in Synthesis Example 1 was dissolved in toluene to obtain a 10% solution.

On the other hand, a transparent conductive layer of indium tin oxide (surface resistance 10 Ω / cm ² ) having a thickness of 0.4 μm is formed on the glass plate.
The counter electrode was formed by m. As the electrochromic transparent electrode, a transparent conductive layer of indium tin oxide on a glass plate was further formed with a layer of tungsten oxide having a thickness of 0.2 μm by a sputtering method.

The above polysilane solution was spin-coated on this, dried at 2 mmHg / 50 ° C., and the thickness was 1.5 μm.
The polysilane thin film of was prepared as a substrate for pattern formation.
This substrate is irradiated with a 500 W high pressure mercury lamp through a mask on which a desired pattern is formed to form a pattern,
A tungsten oxide transparent conductive substrate having a film patterned with an insulating layer of polysilane and an ion conductive layer of polysiloxane was prepared.

The counter electrode and the tungsten oxide transparent conductive substrate were sandwiched by a spacer having a thickness of 2 mm and bonded with an epoxy resin, and then a 0.2 M / l propylene carbonate solution of lithium perchlorate was injected into this space.

A voltage of 1 V was applied with the counter electrode as a positive electrode and the tungsten oxide transparent conductive substrate as a negative electrode.
A blue color was observed which was patterned on the tungsten oxide transparent conductive substrate. Although this color development did not change even when the voltage was 0 V, it disappeared when -1 V was applied, and it was confirmed that the device could be used as an electrochromic device.

[Brief description of drawings]

FIG. 1 is a schematic sectional view showing a configuration of an electrochromic device of the present invention.

FIG. 2 is a schematic cross-sectional view showing a pattern forming method in an electrochromic device of the present invention.

[Explanation of symbols]

1 Transparent electrode substrate 2 Electrochromic material film 2a Coloring part 2b Non-coloring part 3 Polysilane film 3a exposure part 3b Unexposed area 4 Electrolyte layer 5 opposite poles 6 power supply 7 mask 8 Electrolyte holding frame 9 UV

Claims (6)

(57) [Claims] 1. A polysilane film patterned by selective light irradiation is laminated on the electrochromic material film of a transparent electrode substrate on which a film of electrochromic material that develops color by reduction is formed, and on the polysilane film. An electrochromic device, characterized in that a counter electrode is laminated on an electrolyte layer via an electrolyte layer. 2. The polysilane film has the following general formula (1) (R ¹ _m R ² _n X _o Si) _p (1) (wherein R ¹ and R ² are each a hydrogen atom, a substituted or unsubstituted fatty acid). Group, alicyclic or aromatic monovalent hydrocarbon group,
X is the same group as R ¹ , an alkoxy group or a halogen atom. Further, m, n and o are numbers satisfying 1 ≦ m + n + o ≦ 2, and p is an integer of 10 ≦ p ≦ 100,000. ) Is formed of a polysilane represented by
The electrochromic device described. 3. The electrochromic device according to claim 1, wherein the electrochromic substance is tungsten oxide. 4. A polysilane film is formed on the electrochromic material film of a transparent electrode substrate on which a film of an electrochromic material that develops color by reduction is formed, and the polysilane film is selectively irradiated with light, and then the polysilane film is formed. A method for manufacturing an electrochromic device, which comprises laminating a counter electrode on top of the electrolyte layer. 5. The polysilane film has the following general formula (1) (R ¹ _m R ² _n X _o Si) _p (1) (wherein R ¹ and R ² are each a hydrogen atom, a substituted or unsubstituted fatty acid). Group, alicyclic or aromatic monovalent hydrocarbon group,
X is the same group as R ¹ , an alkoxy group or a halogen atom. Further, m, n and o are numbers satisfying 1 ≦ m + n + o ≦ 2, and p is an integer of 10 ≦ p ≦ 100,000. 5. A polysilane represented by:
The manufacturing method described. 6. The method according to claim 4, wherein the electrochromic substance is tungsten oxide.