WO2006087815A1

WO2006087815A1 - Electrodeposition display and method for fabricating the same

Info

Publication number: WO2006087815A1
Application number: PCT/JP2005/002693
Authority: WO
Inventors: Makoto Fukuda; Naoyuki Hayashi; Tsuneo Watanuki
Original assignee: Fujitsu Limited
Priority date: 2005-02-21
Filing date: 2005-02-21
Publication date: 2006-08-24

Abstract

An electrodeposition display performing display by arranging a display composition containing a color developing substance capable of repeating color development and decoloring by deposition and dissolution through oxidation-reduction reaction between a transparent display electrode and a counter electrode, and by coloring or decoloring the color developing substance by conduction between the transparent display electrode and the counter electrode. An electrode layer including a structure insoluble to the display composition and having an air gap in the surface is employed as the counter electrode. An electrodeposition display having high response of display/erasure and ensuring high contrast, high whiteness and high quality display stably even when rewriting is repeated can be attained.

Description

Specification

Electrodeposition display device and manufacturing method thereof

Technical field

[0001] The present invention relates to an electrodeposition display device using a color-developing substance that can be repeatedly developed and decolored by an oxidation-reduction reaction, such as silver.

Background art

[0002] Conventionally, a display device called an electronic paper, a paper-like display, a digital paper, or the like, which displays an image by changing optical absorption or reflection by an electric field has been proposed.

[0003] As an element whose optical absorption and reflection change due to an electric field, a microcapsule containing rotating particles combined with hemispheres having different colors and electrical characteristics together with an insulating liquid, and electrophoretic particles are dispersed. A microcapsule encapsulating this solvent (see Patent Document 1), an electochromic device that utilizes a color change of a substance due to a change in voltage, a dichroic dye and a smectic liquid crystal There are liquid crystal / polymer composite films. Display devices using these technologies are expected to be an alternative to paper because they have memory characteristics, can hold image information without a power source, and are reflective display devices. As a substrate with electrodes, for example, a PET (polyethylene terephthalate) film can be used, so that the display device is thin, light and bendable.

[0004] Among the above, an electro-deposition display device, which is a kind of electochromic display device and deposits and dissolves metal on a transparent display electrode, is characterized by being capable of realizing paper-like contrast and whiteness. (See Patent Documents 2 and 3.) In this electrodeposition display device, a silver halide silver is dissolved in a display composition together with a supporting electrolyte containing a halogen, and the silver is deposited on a transparent display electrode by a predetermined potential to cause color development. . In addition, the silver on the transparent display electrode is re-dissolved by the reverse electric potential, thereby decoloring. Furthermore, by using a white porous background plate together with the display composition, or using a solid electrolyte in which a white inorganic pigment is dispersed, the reflectance and whiteness of the background are increased, and the contrast is high. A method for realizing whiteness has also been proposed (see Patent Documents 4 and 5). [0005] Many of the electrodeposition display devices have a structure in which a layer of a display composition containing a color-developing substance that develops and decolors by oxidation and reduction is sealed between two electrode plates, at least one of which is transparent. Become. By applying a voltage between the two electrode plates and energizing them, the chromogenic material is deposited on the transparent display electrode plate to display. In the case of erasing, by applying a voltage having a potential opposite to that at the time of precipitation, the precipitate is dissolved again and the display is erased. However, when precipitation and dissolution are repeated, dendrites called dendrites, dendritic protrusions, and acicular protrusion deposits are generated and grow on the electrode plate, eventually shorting between the electrodes, There is a known problem that display and deletion are impossible.

[0006] On the other hand, a method of making the material composition of the electrolyte difficult to grow dendrites (see Patent Documents 6 and 7) and the shape of the edge portion of the electrode where precipitates grow easily due to concentration of electric field. A method of controlling metal deposition by rounding the shape (see Patent Document 8) has been proposed.

Patent Document 1: Japanese Patent Application Laid-Open No. 01-086116

Patent Document 2: U.S. Pat.No. 4,240,716

Patent Document 3: U.S. Pat.No. 4,240,717

Patent Document 4: Japanese Patent Application Laid-Open No. 11-101994

Patent Document 5: Japanese Patent Application Laid-Open No. 2002-258327

Patent Document 6: Special Table 2004-513379

Patent Document 7: Special Table 2001-527226

Patent Document 8: Japanese Patent Laid-Open No. 10-274790

Disclosure of the invention

Problems to be solved by the invention

[0007] An object of the present invention is to solve the above-described problems and provide an electrodeposition display technique capable of repeatedly and stably performing display with high reflectance and high contrast. Still other objects and advantages of the present invention will become apparent from the following description.

Means for solving the problem

[0008] According to one embodiment of the present invention, a display composition containing a color-forming substance capable of repeatedly performing color development and decoloration by precipitation and dissolution by an oxidation-reduction reaction is opposed to a transparent display electrode. In an electrodeposition display device that is placed between electrodes and displays by coloring or decoloring the chromogenic substance by energization between the transparent display electrode and the counter electrode, the display composition as the counter electrode There is provided an electrodeposition display device using an electrode layer including a structure that is insoluble in an object and has a void on the surface.

[0009] According to the aspect of the present invention, there is provided an electrodeposition display device capable of stably displaying high-quality images with high contrast and high whiteness even when repeated rewriting is performed at a high response speed of display and erasure. realizable.

[0010] The counter electrode is a combination of a structure that is insoluble in the display composition and that has a void on the surface thereof, and a metal that is contained in the coloring material and that is deposited and dissolved on the electrode. The electrode layer is insoluble in the display composition, and the first layer including the structure having a void on the surface and the chromogenic material are deposited and dissolved on the electrode. The electrode layer is formed by laminating a metal to be formed and a second layer containing the same type of metal, and the electrode layer is insoluble in the display composition and has voids on the surface thereof. The electrode layer contains particles containing the same type of metal as the metal that precipitates and dissolves on the electrode, the counter electrode is insoluble in the display composition, and has a void on the surface. The same type of metal as the metal that precipitates and dissolves on the electrode must be supported on the surface of the structure. It is an electrode layer, the counter electrode includes a structure in which fibers or particles are regularly or irregularly integrated, and the counter electrode is irregularly woven, non-woven fabric, knitted fabric, laminated fabric, mesh or fiber. Included in the coloring material is that it contains an integrated structure, the counter electrode contains carbon, the carbon is made of one or more materials selected from the group consisting of carbon fiber, carbon nanotube, and carbon particles. The metal is a metal selected from the group consisting of silver, bismuth, palladium, copper, lithium, iron, chromium, nickel and cadmium

The porosity of the counter electrode is in the range of 50-95%, the insulating material is disposed between the P-contacting counter electrodes, and the display composition is at least a color-forming material, polymer, colored A solid layer containing an agent and a solvent is a preferred form.

[0011] According to another aspect of the present invention, a display composition containing a color forming substance capable of repeatedly performing color development and decoloration by precipitation and dissolution by an oxidation-reduction reaction is paired with a transparent display electrode. The chromogenic substance is placed between the counter electrode and the energization between the transparent display electrode and the counter electrode. In a method of manufacturing an electrodeposition display device that displays by developing or erasing color, a counter electrode is formed by disposing carbon fiber woven fabric, non-woven fabric, or random aggregate on an electrode substrate. A method of manufacturing a deposition display device is provided.

[0012] According to an aspect of the present invention, there is provided an electrodeposition display device that can stably display a high-quality display with high contrast and high whiteness even when repeated rewriting is performed with a fast response speed of display and erasure. Can be manufactured. The counter electrode is preferably formed by applying a dispersion liquid containing carbon fiber, a binder resin, and a solvent on the electrode substrate.

The invention's effect

[0013] According to the present invention, an electrodeposition display device capable of stable, high-contrast, high-whiteness, high-quality display even when repeated rewriting with a fast display / erase response speed is performed, and its manufacture The method can be realized.

Brief Description of Drawings

FIG. 1 is a schematic cross-sectional view of the entire display panel of an electrodeposition display device.

FIG. 2 is a schematic cross-sectional view of a part of a display panel of an electrodeposition display device.

FIG. 3 is a schematic perspective view of a display panel of an electrodeposition display device.

FIG. 4 is a schematic perspective view of a display panel of an electrodeposition display device.

FIG. 5 is a schematic cross-sectional view of a part of a display panel of an electrodeposition display device.

FIG. 6 is a schematic cross-sectional view of a part of a display panel of an electrodeposition display device.

FIG. 7 is a schematic cross-sectional view of a part of a display panel of an electrodeposition display device.

FIG. 8 is a schematic cross-sectional view of a part of a display panel of an electrodeposition display device.

FIG. 9 is a plan view of a counter electrode substrate in Example 5.

FIG. 10 is a cross sectional view of a counter electrode substrate and a counter electrode in Example 5. Explanation of symbols

1 Display

2 Transparent display electrode

3 Transparent display electrode side substrate

4 Counter electrode

5 Counter electrode side substrate

6 Indication composition

7 Sinore Wall

8 Silver layer

12 Via

13 Wiring

14 Protective layer

15 Auxiliary electrode

51 First layer

52 Second layer

61 Structure

62 particles

71 Electrode layer

81 Counter electrode

82 Insulation layer

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings, examples and the like. In addition, these figures, examples, etc., and description illustrate the present invention and do not limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention. In the drawings, the same reference numeral represents the same element.

[0017] An electrodeposition display device according to the present invention provides a transparent display electrode side substrate provided with a transparent display electrode and a counter electrode side substrate provided with a counter electrode so that the transparent display electrode and the counter electrode face each other. A display composition containing a chromophoric substance in between, and transparent This is an electrodeposition display device that performs display by developing or erasing a chromogenic substance by energization between a bright display electrode and a counter electrode. When a voltage is applied between the transparent display electrode and the counter electrode, the chromophoric material is oxidized or reduced, and the metal contained in the chromophoric material precipitates and dissolves on the transparent display electrode surface, thereby developing and decoloring. Can be repeated.

[0018] The counter electrode according to the present invention is an electrode layer including a structure that is insoluble in the display composition and has a void on the surface. Since the surface has voids, metal ions such as a chromogenic substance contained in the display composition and supporting electrolyte ions described later can easily move and diffuse through the voids. For this reason, compared with a flat electrode, the electrode area effective for the reaction is increased, and the amount of metal necessary for display can be deposited or dissolved in a short time when the reaction efficiency of the chromogenic substance is high. Therefore, it is possible to realize an electrodeposition display device that has a high response speed for display and erasure and can stably display high-quality images with high contrast and high whiteness even when rewriting is performed repeatedly. In addition, when the counter electrode has a structure having a void on the surface, the amount of deposition per unit area on the outermost surface of the electrode can be reduced when metal is deposited on the surface of the counter electrode during decoloring. Therefore, the growth of precipitates outside the electrode can be reduced.

Here, having a void on the surface means that in an electrode layer having a certain volume, there is a space inside the electrode layer where the material constituting the electrode does not exist densely, It means that a substance, for example, a display composition or a part of a material constituting the display composition is filled and the electrolyte can move in the electrode layer. By forming the counter electrode in such a form, even if a precipitate starts to grow on the counter electrode, a certain amount of the precipitate is included in the voids in the electrode, so that the transparent display electrode side The precipitates are less likely to extend on the outermost surface facing in the direction.

[0020] The shape of the structure having voids on the surface according to the present invention may be any shape as long as it is not contrary to the gist of the present invention. Structures with independent pores on the surface, called ordinary porous bodies, structures in which these pores are connected toward the inside, fibers or particles are accumulated regularly or irregularly A structure can be mentioned. In the case of a structure in which fibers or particles are regularly or irregularly integrated, the fibers or particles These gaps form voids on the surface of the counter electrode according to the present invention. Note that the void portion on the surface of the structure according to the present invention does not necessarily indicate a portion existing only on the surface portion. In particular, in the case of a structure in which fibers or particles are regularly or irregularly accumulated, the voids are usually connected deeply.

[0021] In the case of fibers, long fibers or short fibers may be used. The shape of the particles is arbitrary. As particles

Even a collection of single particles or a collection of shapes in which multiple particles are combined, for example, in a bead shape. It can be shaped like a nanotube or nanohorn.

[0022] Examples of the regularly accumulated structures include woven fabrics, nonwoven fabrics, knitted fabrics, laminated fabrics, meshes, and accumulated products. In the case of non-woven fabric, it may or may not use a binder.

[0023] The nonwoven fabric may be an irregularly accumulated structure. Irregularly accumulated structures include those produced by applying a liquid containing short fibers to a substrate or spraying it onto the substrate.

[0024] These structures may be used alone or in combination. The size of these structures is not particularly limited as long as it can be used for the electrodeposition display device according to the present invention.

1 and 2 are schematic cross-sectional views of a display panel of an electrodeposition display device according to the present invention. 1 and 2, the display panel 1 is colored by oxidation and reduction between the transparent display electrode 2 and the counter electrode 4 provided on the opposing transparent display electrode side substrate 3 and the counter electrode side substrate 5, respectively. A display composition 6 containing a color-developing substance capable of repeatedly performing erasing and decoloring is provided. A sealing wall 7 that surrounds and seals the display composition 6 is provided on the inner periphery of the substrates 3 and 5. The arrow indicates the direction in which a person views the display on the display panel 1. In FIG. 2, an example of an electrode layer (counter electrode 4) including a structure that is insoluble in the display composition and has a void on the surface is schematically illustrated as a laminate of short fibers. .

[0026] The counter electrode 4 is a structure that is insoluble in the display composition and has a void on the surface. The counter electrode is patterned in various shapes depending on the configuration of the display device. For example, a dot matrix as shown in Fig. 3 or passive matrix drive In this case, it may be a stripe shape as shown in FIG. 4 or any other shape.

[0027] The counter electrode according to the present invention is insoluble in the display composition and has the same type of structure as the metal having a void portion on the surface and the metal contained in the coloring material and deposited and dissolved on the electrode. The electrode layer is preferably a composite of metal and metal. By using an electrode layer that is a composite of a metal of the same type contained in a chromophoric material that precipitates and dissolves on the electrode, a metal ion is supplied into the display composition, resulting in a display with a high response speed. A device can be made. At this time, the same kind of metal as the metal to be deposited makes it possible to repeat stable coloring and erasing without changing the electrolyte composition when the dissolution reaction and precipitation reaction are repeated.

[0028] Such a composite electrode layer includes (1) a first layer containing a structure which is insoluble in the display composition and has a void portion on the surface thereof, and a color developing substance on the electrode. An electrode layer formed by laminating a metal that precipitates and dissolves in the second layer containing the same type of metal, and (2) a void portion of a structure that is insoluble in the display composition and has a void portion on the surface And an electrode layer containing particles containing the same type of metal as the metal that precipitates and dissolves on the electrode, and (3) a structure that is insoluble in the display composition and has a void on the surface. An electrode layer in which the same type of metal as the metal that precipitates and dissolves on the electrode is supported on the surface can be exemplified.

[0029] These will be further described with reference to FIGS. FIG. 5 shows an electrodeposition display device in which a counter electrode is insoluble in a display composition and includes a first layer including a structure having a void on the surface, and an electrode included in a chromogenic material. It is an example of an electrodeposition display device which is an electrode layer formed by laminating a metal deposited and dissolved above and a second layer containing the same type of metal.

Here, the first layer 51 is disposed in contact with the display composition layer 6, and the second layer 52 is on the opposite side, that is, between the first layer 51 and the counter electrode side substrate 5. Arranged. Here, since the first layer 51 has a void portion on the surface thereof, movement and diffusion of metal ions and supporting electrolyte ions described later are easy as described above.

[0031] With such a structure, an amount of metal necessary for display can be deposited or dissolved in a short time, and the response speed of the display device is increased. metal Since the amount of precipitation per unit area on the outermost surface of the electrode can be reduced, the growth of precipitates outside the electrode can be reduced.

[0032] FIG. 6 shows that in the electrodeposition display device, the counter electrode is insoluble in the display composition and is deposited and dissolved on the electrode in the void portion of the structure 61 having the void portion on the surface. This is an example of an electrodeposition display device which is an electrode layer containing particles 62 containing the same type of metal as the metal.

[0033] Even in such a structure, the amount of metal necessary for display can be deposited or dissolved in a short time, the response speed of the display device can be increased, and the surface of the counter electrode can be discolored during decoloring. When the metal is deposited, the amount of deposition per unit area on the outermost surface of the electrode can be reduced, so that the growth of the deposit to the outside of the electrode can be reduced.

Here, the same type of metal as the metal that precipitates and dissolves on the electrode is, for example, when the metal that precipitates and dissolves on the electrode is silver, the silver is “the same type of metal”. Particles containing the same type of metal as the metal that precipitates and dissolves on the electrode may contain a substance other than the “same type of metal”, for example, a metal, for example, as a component of an alloy. In the following, in order to simplify the description, a case will be described in which particles containing the same type of metal as the metal that precipitates and dissolves on the electrode are particles of only the same type of metal as the metal that precipitates and dissolves on the electrode. .

[0035] It is preferable that the metal particles are sufficiently small with respect to the size of the voids, and the particle diameter is preferably 10 / m or less. Moreover, in order to suppress aggregation, the surface of the metal particles may be coated with a dispersing agent such as a resin or a surfactant, or may be adhered or adsorbed.

[0036] The metal particles may be contained in the voids of the structure having voids on the surface by any method. It may simply be trapped or may be chemically or physically attached or adsorbed to the structure.

[0037] Next, FIG. 7 shows a metal in the electrodeposition display device in which the counter electrode is insoluble in the display composition and is deposited and dissolved on the surface of the structure having voids on the surface. This is an example of an electrodeposition display device that is an electrode layer 71 on which the same kind of metal is supported. The supported metal (not shown) covers the fibrous electrode layer material ing. However, the case where the electrode layer material is not uniformly covered and is supported on the surface while maintaining the particulate shape is also included. The difference between being supported and attached or adsorbed is not related to the essence of the present invention. Even with such a structure, an amount of metal necessary for display can be deposited or dissolved in a short time, the response speed of the display device is increased, and further, metal is deposited on the surface of the counter electrode during decoloring. At this time, since the amount of precipitation per unit area on the outermost surface of the electrode can be reduced, the growth of precipitates outside the electrode can be reduced.

[0038] The support on the electrode surface may be performed by coating the surface of the electrode, for example, by subjecting the surface to electrolytic plating treatment to attach a metal, and then attaching the metal compound to the electrode surface. This may be carried out by reducing the metal to cause the metal particles to adhere to the metal surface.

[0039] There may be a form in which the forms (1) to (3) are combined. For example, a structure in which metal particles are contained or supported in the voids of the structure (1) can be exemplified.

[0040] If the porosity of each of the above-mentioned counter electrodes is less than 50%, the movement and diffusion of the electrolyte ions are hindered and the display speed becomes slow, and the part involved in the reaction of the electrolyte is transparent in the electrode layer. Only in the vicinity of the surface facing the display electrode, the effective electrode area involved in the reaction of the chromogenic substance is reduced, and the precipitates easily grow like protrusions, and the effect of the present invention can be obtained. It becomes difficult. On the other hand, if it exceeds 95%, the resistance of the electrode increases and the display speed decreases, and the surface area of the electrode does not increase as compared with the plate-like case without voids, and the effects of the present invention are difficult to obtain. The porosity is {c / (a X b)} X 100 where true density is a (g / cm ³ ), Balta volume is b (cm ³ ), and its weight is c (g). (%)

[0041] In the electrodeposition display device according to the present invention, it is preferable that an insulating material is disposed between the counter electrodes in contact with P.

[0042] The counter electrode has a limit in thinning and inevitably has a certain thickness. Therefore, when the distance from the adjacent counter electrode is short, current leaks through the display composition. As a result, problems such as the occurrence of so-called crosstalk, in which surrounding pixels develop or decolor, arise. In order to reduce this, it is effective to provide an insulating layer between adjacent counter electrodes. [0043] The insulating material according to the present invention is not particularly limited, and can be used for a counter electrode substrate described later.

[0044] As a method of forming the insulating layer, for example, a sheet-like insulating layer processed into a shape in which the counter electrode portion is cut off is pasted on a plate-like counter electrode substrate, or a photolithographic screen is used. A method of forming a convex portion such as a resin by a known method such as printing is a method in which a concave portion is formed by cutting or the like to form a concave portion and a counter electrode is disposed in the concave portion. As another method, for example, the surface of the counter electrode side substrate is pressed using a mold, or a liquid resin or a raw material composition thereof is cured in the mold. There is a method in which a certain counter electrode substrate is formed in advance and the counter electrode is disposed in the recess. Furthermore, as another method, after disposing the counter electrode on the counter electrode side substrate, an insulating material is disposed between the electrodes or at the end or side of the electrode by a method such as printing or coating, or A method of forming an insulating material such as silica or alumina by sputtering, vapor deposition, ion plating, or the like can be used.

FIG. 8 shows an example in which an insulating layer 82 is disposed between adjacent counter electrodes 81 in the electrodeposition display device. Any of the counter electrodes shown in FIG. By arranging an insulating layer between adjacent counter electrodes in this way, the leakage current flowing between the counter electrodes is suppressed, and the phenomenon of crosstalk that causes coloration or decoloration of adjacent pixels is reduced. it can. Furthermore, power consumption is reduced.

[0046] The counter electrode according to the present invention is indispensable in terms of its properties. From this viewpoint, the counter electrode preferably contains carbon. In addition, carbon is preferably in the form of fibers, rods, needles, les, and a large aspect ratio because the conductivity is increased with a smaller amount. Particles with a small aspect ratio can also be used Force conductivity is somewhat low, resulting in energy loss during operation. There are no particular restrictions on the raw materials for carbon fiber. In addition, as the particles, carbon particles and carbon nanotubes can be cited.

[0047] In the case of carbon fibers, for example, non-woven fabric or cloth-like carbon fibers are suitable.

Examples of commercially available non-woven carbon fibers and woven carbon fibers include carbon paper (manufactured by Toray) and trading card cloth (manufactured by Toray). [0048] Further, as another form of the electrode layer containing a structure that is insoluble in the display composition and has a void on the surface, a paste containing at least carbon fiber and a binder resin is applied. Can also be used. When forming a counter electrode having a complicated shape or a fine shape on the counter electrode side substrate, a method of applying a paste is more suitable. Examples of a method for producing such an electrode include a method in which a carbon fiber and a binder resin dispersed in a volatile solvent are coated in a desired electrode shape and then the solvent is dried. As another production method, a mixture of carbon fiber, a polymerizable compound, and a solvent is coated on a counter electrode substrate in a desired electrode shape, and superposed by heating or active energy ray irradiation to solidify. The method of doing is mentioned.

[0049] As the counter electrode side substrate for supporting the counter electrode, the counter electrode can be formed on the substrate and the display composition can be blocked without being dissolved or deformed by the display composition. Any material can be used, such as quartz glass, soda glass, borosilicate glass, etc., thermoplastic polyester resins such as polyethylene naphthalate and polyethylene terephthalate, polyamide, polycarbonate, Cellulose ester resins such as cellulose acetate, polyvinylidene fluoride, tetrafluoroethylene fluorinated resins such as monohexafluoropropylene copolymer, polyethers such as polyoxymethylene, polyacetal, polystyrene, polyethylene , Polypropylene, methyl pentene polymer, etc. Indo, Zeonor, ZEONEX (manufactured by ZEON Corporation, Arton CJSR) and other products such as cycloolefin resins represented by product brands, polyimide resins such as polyamide-amide and polyetherimide, and glass nonwoven fabric base epoxy resins And so on.

[0050] Since the transparent display electrode needs to have high transmittance for visible light for the purpose of display, for example, ITO (indium tin oxide), FT0 (Foot) is formed on the transparent display electrode side substrate surface. Elementally doped tin oxide), SnO, and IZO (indium zinc oxide) are produced by vapor deposition or coating. Further, an inorganic material layer such as silicon oxide or aluminum oxide, or an organic material film such as polyamide may be formed between the conductive material layer and the transparent display electrode side substrate. As a result, effects such as improved adhesion of the conductive material layer and improved barrier properties against gases and solvents can be obtained. The image is displayed by energization between the electrodes. Further, this is performed by causing the color developing substance in the vicinity of the transparent display electrode to color by electrochemical oxidation or reduction reaction.

[0051] The transparent display electrode is disposed on the transparent display electrode side substrate directly or via a layer provided for the purpose of improving adhesion between the transparent display electrode and the substrate. The material of the transparent display electrode side substrate needs to be transparent, and is capable of using transparent glass such as quartz glass, soda glass, and borosilicate glass. Thermoplastic polyester resins such as polyethylene terephthalate, cellulose esters such as polyamide, polycarbonate, and cellulose acetate, fluoropolymers such as polyvinylidene fluoride, polytetrafluoroethylene, and hexafluoropropylene, and polyoxymethylene Polyolefins such as polyethers, polyacetals, polystyrene, polyethylene, polypropylene, methylpentene polymer, Zeonor, Zeonex (manufactured by Zeon Japan, Arton CFSR), and cycloolefin-based trees represented by two product brands It can be cited as examples of polyimides such as classes and polyimide amide Ya polyetherimide.

[0052] The display composition that can be used in the present invention contains at least a color-developing substance capable of repeatedly performing color development and decoloration by an oxidation-reduction reaction. Support electrolyte for accelerating or stabilizing the dissolution and reaction of chromogenic substances in the solvent, polymer for solidifying or increasing the viscosity of the display composition, colorant for coloring the display screen, transparent display electrode And a spacer for keeping the distance between the electrode and the counter electrode constant.

[0053] The solvent contained in the display composition is used for dissolving or swelling these coloring substances, supporting electrolytes, and polymers. The amount of solvent used can be determined arbitrarily according to the actual situation.

[0054] As such a solvent, an aprotic polar solvent is preferred in order to suppress the generation of hydrogen gas due to the oxidation-reduction reaction. Specific examples include dimethylformamide (DMF), dimethylsulfoxide (DMSO), and jetyl. Formamide (DEF), N, N-dimethylacetamide (D MAA), N-methylpropionic acid amide (MPA), N-methylpyrrolidone (NMP), propylene carbonate (PC), ethylene carbonate (EC), Oxamethyl phosphate triamide, Sulfolane, acetonitrile (AN), 2-ethoxyethanol (EEOH), 2-methoxyethanol (MEOH), dioxolane (DOL), ethyl acetate (EA), tetrahydrofuran (THF), methyltetrahydrofuran (MeTHF), dimethoxyether Tan (DME), γ_butyrolacton (GBL), pyridine, ethyl alcohol, isopropyl alcohol, water, etc. can be used, and these may be used in combination.

[0055] As the polymer contained in the display composition, known materials such as polybulurpyrrolidone, polyvinylidene fluoride, polyacrylonitrile and the like can be used. Moreover, what polymerized bulul polymerizable compounds, such as a bur monomer and a bulul oligomer, may be used. Examples of the butyl polymerizable compound that can be used include butyl alcohol, methoxydiethylene glycol methacrylate, methoxytriethylene glycol acrylate, and phenoloxy acrylate. , Pyrrole pyrrolidone, ethylene glycolidene methacrylate, propylene glycololidine methacrylate, polyethylene glycolol diatalylate, 2-hydroxy-1,3-dimethacryloxypropane, 2-hydroxy-1-atarioxy-3-methacryloxypropane, tricyclode Candimethanol ditalidate, 1,6-hexanediol diglycidyl ether ditalylate, 1,4-butanediol diglycidinole ether ditalylate, diethylene glycol diglycidyl ester Ether di Atari rate preparative trimethylolpropane trimethacrylate tributary rate, tetramethylolmethane trimethacrylate tributary rate, tetramethylene Chi roll tetra Atari rate, pentaerythritol tetra Atari rate, include known materials such as hexa Atari rate to Jipentaeri Suritoru.

[0056] In order to react the bulle polymerizable compound, a polymerization initiator can be added.

Examples of such a polymerization initiator include known materials such as azo polymerization initiators and peroxides. The polymerization initiator is preferably added in an amount of 0.5 to 10 parts by weight with respect to 100 parts by weight of the Bull polymerizable compound.

[0057] Known materials can be used as the chromogenic substance capable of repeatedly performing color development and decoloration by an oxidation-reduction reaction. For example, it is possible to list metal salt compounds containing ions that can be deposited, such as bismuth, palladium, copper, silver, lithium, iron, chromium, nickel, and cadmium. In particular, in an electrodeposition display device capable of high-contrast display by electrodeposition, it is preferable to use halogenated silver as a chromogenic substance. [0058] As silver halide, silver fluoride (AgF), silver chloride (AgCl), silver bromide (AgBr), or silver silver with silver (Agl) can be used. Silver iodide is preferred from the viewpoint of solubility. Further, the concentration of silver halide is preferably 0.05 to 5.0 moL / L.

[0059] In addition to these chromogenic substances, the display composition may contain other supporting electrolytes in order to adjust the solubility and reactivity of the chromogenic substance. Supporting electrolytes for dissolving silver halide silver include ammonium iodide, tetraethyl ammonium iodide, potassium iodide, potassium bromide, potassium chloride salt, sodium iodide, sodium bromide, sodium chloride, Known materials such as lithium iodide, lithium bromide, and lithium chloride can be used. In view of the display speed of the electrodeposition display device and the solubility of silver halide, it is preferable to use an ammonium salt. The supporting electrolyte is preferably in the range of 0.1 to 12 moles times the silver halide concentration.

[0060] In addition, other supporting electrolytes include perchlorates such as tetrabutyl ammonium perchlorate, tetraethyl ammonium perchlorate, isocyanato thiocyanate, ammonium thiocyanate, sodium sulfate, Known materials such as thiocyanate, sulfate, oxalic acid, maleic acid, malonic acid, fumaric acid, lactic acid, and salicylic acid can be used.

[0061] The display composition according to the present invention may contain a colorant in order to adjust the color of the non-display portion. As such a colorant, it is preferable to use a fine powder insoluble in the above-mentioned solvent. In order to improve contrast, it is preferable to add a white pigment.

[0062] Specific examples of white pigments include titanium dioxide, silicon dioxide, calcium carbonate, ano-reminium, barium titanate, zirconium oxide and the like. From the viewpoint of power hiding ratio, it is preferable to use titanium dioxide. ,.

[0063] In addition, inorganic pigments such as iron oxide, and organic pigments such as copper phthalocyanine pigments and quinacridone pigments can also be used. The pigment concentration is not particularly limited, but it is preferable to add 5 to 100% by weight in the display composition. When the amount added is small, the concealability is low and sufficient coloring cannot be performed. On the other hand, when the addition amount is too large, it is difficult to uniformly disperse the pigment, and the pigment aggregates to reduce colorability and cause color unevenness.

[0064] The ratio of each component in the display composition according to the present invention is not particularly limited. Although it can be arbitrarily determined according to the situation, a solid layer containing at least a chromogenic substance, a polymer, a colorant and a solvent is easy to handle and there is no risk of leakage from the apparatus. preferable. Here, the solid layer means a layer that does not have fluidity such as a liquid, and may be a so-called solid, but may be deformable, for example, clay. In order to obtain a solid layer, it is preferable to contain 5% by weight or more of the polymer component in the display composition.

[0065] The spacer according to the present invention is preferably in the form of a particle having a small contact area with the transparent display electrode in that it can be used in the form of particles or columns and does not interfere with force display. Any material can be used for the spacer as long as it is insoluble in the other components in the display composition. For example, various ceramics such as glass, silica, anoremina, dioleourea and aluminum nitride, resins such as polyethylene, polypropylene and styrene dibenzene, metals such as iron and stainless steel can be suitably used. The size of the particulate spacer can be selected appropriately according to the purpose. Generally, the average particle size is preferably in the range of 20-1000 μΐη. Smaller variations in particle size are preferred. Further, the shape of the particulate spacer may not be a perfect sphere, and other fine particles may be attached to the surface of the particles, and the surface of the particles may be uneven.

[0066] As a method of manufacturing such an electrodeposition display device, a transparent display electrode side substrate provided with a transparent display electrode and a counter electrode side substrate provided with a counter electrode are used. Manufacture of an electrodeposition display device in which a display composition containing a chromogenic substance capable of repeatedly performing color development and decoloration by precipitation and dissolution by oxidation-reduction reaction is arranged oppositely while facing each other. A method can be mentioned.

[0067] The display composition may be disposed between the transparent display electrode and the counter electrode by any method such as coating, vacuum injection, and transfer. For example, the transparent display electrode side substrate and the counter electrode side substrate are bonded together by sealing the periphery with a sealant, and a liquid display composition is injected into the space sealed by the seal wall, An example is a method in which the display composition is preliminarily formed into a sheet and then sandwiched between the transparent display electrode side substrate and the counter electrode side substrate under reduced pressure to seal the periphery.

[0068] When a liquid display composition is used, for example, a polymerizable compound is used as a raw material. After the liquid display composition is injected between the transparent display electrode and the counter electrode, the polymerizable compound is polymerized or cross-linked to form the solid layer described above. That power S. In the case of using a sheet-shaped display composition in advance, it may be handled as a solid layer as it is, or may be further polymerized or crosslinked.

[0069] In the electrodeposition display device, it is preferable to form a counter electrode by disposing carbon fiber woven fabric, non-woven fabric or random aggregate on an electrode substrate. Such a counter electrode is preferable because it can be easily prepared by applying a dispersion containing carbon fiber, a binder resin, and a solvent on the electrode substrate.

[0070] In this way, it is possible to easily form a counter electrode having a void on the surface thereof, and thus deposit the amount of metal necessary for display in a short time when the reaction efficiency of the chromogenic substance is high. Electrodeposition display that can stably display high-quality images with high contrast and high whiteness even after repeated rewriting due to the fact that it can be dissolved. An apparatus can be realized. Example

Next, examples and comparative examples of the present invention will be described in detail.

[0072] [Example 1]

(1) Preparation of raw material composition for display

Dissolve silver iodide (1. OmolZL), ammonium iodide (1. Omol / L), and ammonium thiocyanate (0.5 molZL) in a mixed solvent of propylene carbonate and ethylene carbonate to obtain an electrolyte solution. For Og, 2-hydroxy_1,3-dimethacryloxypropane (701: Shin-Nakamura Chemical Co., Ltd.) 0.9g and 1,6-hexanediol diglycidyl ether atrelate (EA-5521: Shin-Nakamura Chemical Co., Ltd.) 0.9 g and Cyanoresin (CR—S: manufactured by Shin-Etsu Chemical Co., Ltd.) 0.2 g and polymerization initiator V-65 (manufactured by Wako Pure Chemical Industries, Ltd.) 0.05 g were dissolved and mixed. Next, titanium dioxide fine particles CR-58 (Ishihara Sangyo Co., Ltd.) 8. Og was dispersed in this mixture to produce a white liquid display raw material composition.

[0073] (2) Preparation of test sheet

ITO (surface resistance 10 Ω / port) was formed in stripes (line width 7 mm, line spacing lmm) on a glass substrate to form a transparent display electrode. [0074] A heat-sealing sheet was placed on a polyethylene naphthalate substrate (Q65, Teijin DuPont Films Co., Ltd., thickness 0.2 mm), and a striped silver foil (line width 6 mm, line spacing lmm) was placed on it. Furthermore, after placing carbon paper TGP—H-030 (made by Toray) (thickness 0. l lmm, porosity 80%) cut into stripes with a line width of 7 mm on it, 120. Crimping was performed with C to produce a counter electrode.

[0075] Next, the transparent display electrode and the counter electrode were bonded to each other via a sheet-like heat fusion resin bond-in TX8030 (manufactured by Sumitomo Chemical Co., Ltd.) having a frame shape, and an empty cell was produced by thermocompression bonding. .

[0076] Next, the display raw material composition prepared in (1) was injected into the space between the electrodes of the empty cell under a reduced pressure of the injection loca, and then heated at 80 ° C for 2 hours to display the raw material for display. The display raw material composition was solidified by polymerization of the vinyl polymerizable compound in the composition (that is, the display composition was formed). Thereafter, the inlet was sealed under reduced pressure to prepare a test sheet.

[0077] (3) Repeated display test

Repeated test of coloring and erasing by applying voltage of 1.0V, 0.3 seconds, erasing + 1.2V, 0.3 seconds alternately every 1 second when coloring on transparent display electrode of test sheet As a result, stable operation was shown over 1 million times.

[Example 2]

Propylene carbonate / ethylene carbonate mixed solvent 18. Og, 2-hydroxy-1,3-dimetatalyloxypropane (701: Shin-Nakamura Chemical Co., Ltd.) 0 · 9 g, 1,6-hexanediol diglycidyl monoteratalylate (EA — 5521: Shin-Nakamura Chemical Co., Ltd.) 0.9g and Cyanoresin (CR—S: Shin-Etsu Chemical Co., Ltd.) 0.2g, polymerization initiator V-65 (Wako Pure Chemical Industries, Ltd.) 0.05g A suspension in which -6080 (Tanaka Kikinzoku Kogyo) was dispersed was prepared.

[0079] Next, carbon paper TGP_H_030 (manufactured by Toray) was immersed in this suspension under reduced pressure, and then the carbon paper was taken out of the suspension and heated at 80 ° C for 1 hour to disperse the silver fine particles in the voids. Carbon paper was produced. A test sheet was prepared in the same manner as in Example 1 except that the carbon paper in which the silver particles were dispersed was used as the carbon paper for the counter electrode. The amount of silver fine particles per lcm ^{2 of} carbon paper is 0. OlOg [0080] Color development and color erasing are performed by alternately applying a voltage of 1.0 V, 0.3 seconds, and decoloring + 1.2 V, 0.3 seconds to the transparent display electrode of this test sheet every second. When the above test was repeated, stable operation was observed over 1 million times.

[0081] [Example 3]

A test sheet was produced in the same manner as in Example 1 except that the carbon fiber surface of carbon paper TGP_H_030 (manufactured by Toray) with silver attached to the surface by electrolytic plating was used as the counter electrode. The adhesion amount of silver fine particles per lcm ^{2 of} carbon paper was 0.005 g / cm ² .

[0082] On the transparent display electrode of this test sheet, a voltage of 1.0 V, 0.3 s, decoloring + 1.2 V, 0.3 s was applied alternately every 1 s when coloring and disappearing. A repeated color test showed stable operation over 1 million times.

[0083] [Example 4]

A heat-sealing sheet is placed on a polyethylene naphthalate substrate (Q65, Teijin DuPont Films Co., Ltd., thickness 0.2 mm), and striped silver foil (thickness 0 · 03 mm), line width 6 mm, line spacing lmm) Was pasted by heating. Next, carbon fiber VGCF (manufactured by Showa Denko) (fiber length 10-20 / im) in butyl acetate in which polybulurpyrrolidone (K90; manufactured by Wako Pure Chemical Industries) was dissolved in a strip shape with a line width of 7 mm on a silver foil. A suspension in which a fiber diameter of 150 nm) was mixed and dispersed was applied and then dried to obtain a counter electrode.

A test cell was produced in the same manner as Example 1 using this counter electrode. This test sheet repeats coloring and decoloring by applying alternating voltage of 1.2 V, 0.6 seconds, and decoloring +1.4 V, 0.6 seconds every 2 seconds. As a result, stable operation was shown over 1 million times.

[0085] [Example 5]

A test sheet using a dot matrix counter electrode (1.8 X 1.8 mmZ dots, inter-dot space 0.2 mm) shown in Figs. 9 and 10 was prepared. Here, as the transparent display electrode 2, ITO (10 Ω / port) was formed on the glass transparent display electrode side substrate 3 by sputtering, and the auxiliary electrode 15 was arranged around the periphery. The auxiliary electrode 15 was connected to a driving power source. On the other hand, the dot portion of the transparent counter electrode side substrate is recessed, and the counter electrode 4 and the silver layer 8 are arranged. Opposite power The pole 4 is the surplus paste that was applied from the electrode surface using a scraper after applying the carbon fiber paste prepared in Example 4 on the counter electrode-side substrate 5 provided with the silver layer 8 and filling the recess under reduced pressure. Was removed and heated at 80 ° C for 1 hour. The silver layer 8 is electrically connected to the back wiring 13 through the via 12, and the wiring 13 is connected to the driving power source. A protective layer 14 is formed on the back surface.

[0086] Next, the transparent display electrode and the counter electrode were bonded to each other through a frame-shaped seal wall 7 to produce an empty cell. Here, Bondine TX8030 (manufactured by Sumitomo Chemical Co., Ltd.) was used as the seal wall 7. Next, the display raw material composition prepared in Example 1 (1) was injected into the space between the electrodes of the empty cell under reduced pressure of the injection loca, and then heated at 80 ° C. for 2 hours to be used for display. The raw material composition for display was formed into a solid layer by polymerization of the vinyl polymerizable compound in the raw material composition (that is, the display composition was formed). Thereafter, the inlet was sealed under reduced pressure to prepare a test sheet.

[0087] When a voltage was applied between the electrodes of the test sheet to repeat the coloring and decoloring tests, stable operation was exhibited over 1 million times.

[0088] [Comparative Example 1]

A test sheet was prepared in the same manner as in Example 1 except that the counter electrode was only silver foil.

[0089] On the transparent display electrode of this test sheet, a voltage of 1.0 V, 0.3 s, and erasing +1.2 V, 0.3 s are applied alternately every 1 s for coloring and erasing. When the color was repeatedly tested, the electrodes were short-circuited at about 100,000 times, making display impossible.

Claims

The scope of the claims

[1] A display composition containing a coloring material that can be repeatedly colored and decolored by precipitation and dissolution by an oxidation-reduction reaction is disposed between a transparent display electrode and a counter electrode, and the transparent In an electrodeposition display device for performing display by developing or erasing the chromogenic substance by energization between a bright display electrode and the counter electrode.

An electrodeposition display device using, as the counter electrode, an electrode layer including a structure insoluble in the display composition and having a void on the surface.

[2] The counter electrode is insoluble in the display composition and has a structure having a void on the surface, and a metal of the same type as the metal contained in the coloring material and deposited and dissolved on the electrode; The electrodeposition display device according to claim 1, wherein the electrode layer is a composite electrode layer.

[3] A metal that is insoluble in the display composition and includes a first layer including a structure having a void on the surface and a metal that is deposited and dissolved on the electrode in the chromogenic material. The electrodeposition display device according to claim 1, which is an electrode layer formed by laminating a second layer containing the same type of metal.

[4] Particles containing the same type of metal as the metal that precipitates and dissolves on the electrodes in the voids of the structure in which the electrode layer is insoluble in the display composition and has voids on the surface. 2. The electrodeposition display device according to claim 1, wherein the electrodeposition display device is an electrode layer.

[5] The counter electrode is insoluble in the display composition and has a void on the surface thereof. The electrode is formed by supporting the same type of metal as the metal that precipitates and dissolves on the electrode. The electrodeposition display device according to claim 1, wherein the electrodeposition display device is a layer.

6. The electrodeposition display device according to claim 1, wherein the counter electrode includes a structure in which fibers or particles are regularly or irregularly integrated.

7. The electrodeposition display device according to claim 1, wherein the counter electrode includes a woven fabric, a nonwoven fabric, a knitted fabric, a laminated fabric, a mesh, or a structure in which fibers are irregularly integrated.

8. The electrodeposition display device according to claim 1, wherein the counter electrode contains carbon.

[9] The electrodeposition display device according to [1], wherein the carbon is made of one or more materials selected from the group consisting of carbon fibers, carbon nanotubes, and carbon particles.

[10] The electrodeposition according to claim 1, wherein the metal contained in the coloring substance is a metal selected from the group consisting of silver, bismuth, palladium, copper, lithium, iron, chromium, nickel, and cadmium. Display device.

[11] The electo-deposition display device according to claim 1, wherein the counter electrode has a porosity of 50 to 95%.

[12] The outer electrode deposition display apparatus according to [1], wherein an insulating material is disposed between adjacent counter electrodes.

13. The electrodeposition display device according to claim 1, wherein the display composition is a solid layer containing at least a color forming substance, a polymer, a colorant and a solvent.

[14] A display composition containing a coloring material that can be repeatedly colored and decolored by precipitation and dissolution by an oxidation-reduction reaction is disposed between a transparent display electrode and a counter electrode, and the transparent In a method for manufacturing an electrodeposition display device that performs display by coloring or decoloring the chromogenic substance by energization between a bright display electrode and the counter electrode, carbon fiber woven fabric, non-woven fabric, or random integration A method of manufacturing an electrodeposition display device, wherein the counter electrode is formed by placing an object on an electrode substrate.

15. The method for manufacturing an electrodeposition display device according to claim 14, wherein the counter electrode is formed by applying a dispersion containing carbon fiber, a binder resin, and a solvent on the electrode substrate.