JP2010224240A - Electrochromic display element and method for manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochromic display element having performance excellent in reliability, and to provide a method for manufacturing the electrochromic display element. <P>SOLUTION: The electrochromic display element includes: a display substrate 1; and an opposite substrate 6 arranged opposite to the display substrate 1. In addition, the electrochromic display element has: a first partition 7 which is formed in a display area 11 having a plurality of pixels 10; and a second partition 8, which surrounds the display area 11 and formed of the same material as that of the first partition 7 between the display substrate 1 and the opposite substrate 6. In addition, an electrolyte layer 4 is formed in a recessed part which is surrounded by the first partition 7. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electrochromic display element and a manufacturing method thereof.

  With the proliferation of computers in the office, the amount of paper used for document storage and transmission has decreased, but the tendency to print and read on paper when browsing digital information is still persistent. Accordingly, the amount of paper discarded only by temporary use tends to increase in recent years. Further, the amount of paper consumed daily for books, magazines, newspapers, etc. is a threat from the viewpoint of resources and the environment, and these are unlikely to decrease unless the medium changes. However, in consideration of human information recognition methods and thinking methods, the superiority of “paper” over “displays” such as CRT (cathodery tube) and transmissive liquid crystal cannot be ignored.

  Therefore, in recent years, as an electronic medium that replaces paper, it is expected to realize electronic paper that combines the advantages of paper with the advantages of a display that can handle digital information as it is. Necessary characteristics expected for electronic paper include a reflective display element, a high white reflectance and a high contrast ratio, a high-definition display, and a memory effect on the display. It can be driven by voltage, it is thin and light, and it is inexpensive.

  Electronic paper display methods include a reflective liquid crystal method, an electrophoresis method, a two-color ball method, an electrochromic method, and the like. The reflective liquid crystal system is a display element that uses a polarizing plate that utilizes the optical rotation and birefringence of the liquid crystal, so that it is dark, and due to the nature of the metal reflector, the white display becomes a reflected light. Have. For this reason, if a user keeps looking at the screen for a long time, a considerable burden is placed on the eyes.

  The electrophoresis method uses a phenomenon called electrophoresis in which a white pigment, black toner, or the like moves on an electrode by the action of an electric field. The two-color ball display system is composed of spheres that are separately painted in two colors, such as white in half and black in half, and utilizes rotation by the action of an electric field. Both methods require a gap that allows the granular material to enter, and it is difficult to obtain a high contrast because it is not possible to close the packing.

  The electrochromic system utilizes the fact that a reversible oxidation-reduction reaction occurs when an electric field is applied, and color development / decoloration associated therewith occurs. Since the electrochromic method is a reflective display element that repeats color development / decoloration electrically, it can be said that it is advantageous in terms of the burden on the eyes and the contrast with respect to other display methods (Patent Document 1). 2, 3, 4).

  As a method for displaying an arbitrary pattern with a display element using such an electrochromic method, a simple matrix driving method is generally used. In order to perform display by a matrix driving method, a plurality of striped transparent electrodes are formed as display electrodes and counter electrodes in the display element. And each electrode is arranged so that it may oppose and cross | intersect. In the electrochromic element having such a configuration, a display electrode and a counter electrode are selected one by one and an appropriate voltage is applied between them. Thereby, it is possible to cause coloring / decoloring due to the electrochromism phenomenon only in the pixel portion where the selected electrodes intersect. Such a simple matrix driving method is not limited to an electrochromic display element, and is also a method performed with a liquid crystal display element or the like.

  However, in the case of simple matrix driving, since the electric field spreads around the area to which the voltage is applied, other pixels near the target pixel are also colored / decolored (cross) Talk). Conventionally, as a method for eliminating crosstalk in an electrochromic element, there is a method using active matrix driving (see, for example, Patent Document 5). In the case of active matrix driving, a switching element is connected to each pixel, and only the target pixel is electrically connected. In addition, a configuration is known in which an electrochromic solution is filled in a groove provided in a substrate so that an electric field does not spread outside a target pixel (see, for example, Patent Document 6).

  However, these methods have some problems. First, in the case of active matrix driving using a switching element as described in Patent Document 5, a switching element for driving a pixel must be installed in each pixel. There is a problem that the manufacturing cost of the product increases. In addition, a region for forming a switching element has to be provided in the vicinity of the pixel, and there is a problem that an area that can be used for display is relatively reduced.

  On the other hand, as described in Patent Document 6, by forming an electrode inside a recess provided in a substrate, high resolution is obtained by a method of forming a substrate shape in which an electric field does not widen other than the target pixel. For this reason, it is difficult to reduce the pixel. A photolithography technique often used as a patterning method is a technique for a flat substrate. Therefore, it is difficult to apply the photolithography technique when forming the electrode in the recess, and a special patterning method is required. This can be a factor that increases manufacturing costs.

  Therefore, as a method for solving these problems, a separator having a large number of through holes is installed between the upper substrate and the lower substrate, and an electrolyte is filled in the through holes on the separator, so that adjacent electrodes can be formed. There is also a method for preventing the electric field from spreading (see Patent Document 7). However, this method also has a problem that the response speed is slow because the separator is filled with the electrolyte.

  Therefore, as a display element that solves this problem, a display element in which a first partition wall is provided around an electrode corresponding to each pixel, an electrolyte is filled therein, and a counter substrate is bonded to the display element can be considered. As a result, crosstalk due to the electrolyte is prevented, and since the electrolyte is in contact with the entire surface of the pixel electrode, an element having a high response speed can be obtained.

JP 2002-287173 A JP 2006-208862 A JP 2006-058617 A JP-A-7-134317 JP-A-56-165186 JP-A-8-137712 JP 2004-226735 A

  In the formation of the electrochromic display element shown in the prior art, it is necessary to attach the counter substrate after filling the electrolyte in the first partition corresponding to each pixel. For example, when a liquid electrolyte (electrolytic solution) is used in order to obtain an element having a high response speed, it is necessary to fill the electrolytic solution with a sufficient amount so as to contact the entire electrode surface. If the counter substrate is bonded in this state, excess electrolyte overflows from the outermost periphery of the first partition wall. Further, at this time, when a sealing resin for bonding between the substrates is provided on the outermost periphery of the first partition, there is a high possibility of causing poor curing due to the contact between the electrolytic solution and the sealing resin.

  Accordingly, the present invention has been made in view of the above-described problems, and an object thereof is to provide an electrochromic display element having a performance with excellent reliability and a method for manufacturing the same.

  The electrochromic display element according to the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, and a plurality of electrochromic display elements between the first substrate and the second substrate. The first partition formed in the display region having the pixels and the first substrate and the second substrate surround the display region and are formed of the same material as the first partition. A second partition and an electrolyte layer formed in a recess surrounded by the first partition. Thereby, the EC display element has a performance excellent in reliability.

  Further, in the electrochromic display element, the sealing resin is formed on a side opposite to the first partition with respect to the second partition, and bonds the first substrate and the second substrate. It is preferable to further have.

  In the above electrochromic display element, it is preferable that an adhesive layer is formed on at least one of the first partition and the second partition. Thereby, crosstalk due to the electrolyte in the electrolyte layer is less likely to occur. In addition, the adhesive strength between the substrates is improved.

  Furthermore, in the above electrochromic display element, the electrolyte layer is preferably formed of a liquid electrolyte. This makes it easier to fill the electrolyte into the first partition wall, and further increases the response speed.

  On the other hand, an electrochromic display element according to the present invention includes a first substrate, a second substrate disposed opposite to the first substrate, and between the first substrate and the second substrate. A first partition formed in a display region having a plurality of pixels, a second partition surrounding the display region between the first substrate and the second substrate, and the first partition An electrolyte layer formed in a recess surrounded by the substrate, and a seal formed on the opposite side of the first partition to the second partition, and bonding the first substrate and the second substrate together And a stop resin. Thereby, the EC display element has a performance excellent in reliability.

  In the method for manufacturing an electrochromic display element according to the present invention, a first partition is formed in a display region having a plurality of pixels on a first substrate, and the display region is formed of the same material as the first partition. Forming a surrounding second partition; forming an electrolyte layer in a recess surrounded by the first partition; and sandwiching the electrolyte layer between the first substrate and the second substrate As described above, the method includes a step of bonding the first substrate and the second substrate. Thereby, the EC display element has a performance excellent in reliability.

  Further, in the method of manufacturing the electrochromic display element, in the step of forming the first partition and the second partition, the first partition and the second partition are formed simultaneously. Is preferred. Thereby, productivity can be improved.

  And it is a manufacturing method of said electrochromic display element, Comprising: In the process of forming the said electrolyte layer, it is preferable to form the said electrolyte layer by apply | coating electrolyte by the inkjet method. By using the ink jet method, the amount of electrolyte filled in the recess surrounded by the first partition wall can be controlled, and excess filling can be reduced.

  On the other hand, in the method for manufacturing an electrochromic display element according to the present invention, a first partition is formed in a display region having a plurality of pixels on a first substrate, and a second partition surrounding the display region is formed. A step of forming an electrolyte layer in a recess surrounded by the first partition; and the second partition so as to sandwich the electrolyte layer between the first substrate and the second substrate On the other hand, a step of bonding the first substrate and the second substrate through a sealing resin formed on the side opposite to the first partition is provided. Thereby, the EC display element has a performance excellent in reliability.

  ADVANTAGE OF THE INVENTION According to this invention, the electrochromic display element with the performance excellent in reliability and its manufacturing method can be provided.

It is the schematic which shows the structure of EC display element concerning embodiment. It is a schematic sectional drawing which shows the other structure of EC display element concerning embodiment. It is a schematic sectional drawing which shows the manufacturing method of EC display element concerning embodiment.

Embodiments An electrochromic display element is one in which a coloring layer and an electrolyte layer exhibiting electrochromic (hereinafter referred to as EC) characteristics are formed between a first electrode layer and a second electrode layer. . The EC display element is a reflective display element that repeats coloring / decoloring by applying a forward voltage and a reverse voltage to electrodes. First, the configuration of the EC display element will be described with reference to FIG. FIG. 1A is a schematic top view showing the configuration of the EC display element. In FIG. 1A, the display electrode and the counter electrode are represented by dotted lines. FIG.1 (b) is IB-IB schematic sectional drawing of Fig.1 (a).

  As shown in FIG. 1A, the plurality of first electrode layers (display electrodes) 2 are formed in parallel at regular intervals. Similarly, the plurality of second electrode layers (counter electrodes) 5 are formed in parallel at regular intervals. The display electrode 2 and the counter electrode 5 intersect. Specifically, the display electrode 2 and the counter electrode 5 are orthogonal to each other. A portion where the display electrode 2 and the counter electrode 5 intersect is a pixel 10. The pixels 10 are arranged in an array.

  The first partition 7 is formed in the display area 11. The display area 11 is an area in which a plurality of pixels 10 are arranged in an array. The first partition 7 is formed so as to surround each pixel 10. That is, the first partition 7 is formed so as to define the pixel 10. The second partition 8 is formed on the outermost periphery of the first partition 7 so as to surround all the pixels 10. That is, the second partition wall 8 is formed so as to surround the display area 11. Inside the second partition 8 is the first partition 7. The sealing resin 9 is formed so as to surround the second partition wall 8. The sealing resin 9 is formed on the side opposite to the first partition 7 with respect to the second partition 8. That is, the first partition wall 7 and the second partition wall 8 are inside the sealing resin 9.

  As shown in FIG. 1B, the display electrode 2 is formed on the display substrate 1 which is an insulating substrate. On the display electrode 2, a first partition 7, a second partition 8, and a sealing resin 9 are formed. The first partition wall 7 and the second partition wall 8 are formed on the display substrate 1 side, for example, and are not bonded to the counter substrate 6 described later. The first partition wall 7 and the second partition wall 8 have the same height as the inter-substrate spacing. That is, there is almost no gap between the upper end of the first partition 7 and the upper end of the second partition 8. Moreover, the 1st partition 7 and the 2nd partition 8 can be formed with the same material.

  In the recess surrounded by the first partition wall 7, a coloring layer (EC material layer) 3 and an electrolyte layer 4 are sequentially provided. The EC material layer 3 is a coloring layer that has electroactivity and changes color by electrochemical oxidation or reduction. The EC material layer 3 is formed for each pixel 10. For each pixel 10, for example, cyan (C), magenta (M), and yellow (Y) dyes that can be used for subtractive color mixing are applied to the EC material layer 3, and each color is applied separately. Display can be made. The electrolyte layer 4 is formed of a liquid, gel, solid, or other electrolyte.

  A counter substrate 6 that is an insulating substrate is disposed to face the display substrate 1. A counter electrode 5 is formed on the display substrate 1 side of the counter substrate 6. In each pixel 10, the display electrode 2 and the counter electrode 5 are disposed to face each other. In each pixel 10, the EC material layer 3 and the electrolyte layer 4 are sandwiched between the display electrode 2 and the counter electrode 5. Thus, in each pixel 10, the display electrode 2, the EC material layer 3, the electrolyte layer 4, and the counter electrode 5 are formed in order from the viewing side. The display electrode 2 and the EC material layer 3, the EC material layer 3 and the electrolyte layer 4, and the electrolyte layer 4 and the counter electrode 5 are in direct contact with each other.

  The sealing resin 9 bonds the display substrate 1 and the counter substrate 6 together. That is, the sealing resin 9 bonds and seals between the substrates. Specifically, the display substrate 1, the display electrode 2, the counter electrode 5, and the counter substrate 6 are bonded to the sealing resin 9. The EC display element is configured as described above.

  The EC display element according to the present embodiment has a first partition wall 7 for separating the electrolyte layer 4 into each pixel 10. For this reason, it is possible to perform color development / decoloration independently without crosstalk. A second partition 8 is provided so as to surround the display area 11. For this reason, even if the electrolyte filled in the pixel 10 overflows, it hardly overflows outside the element. That is, the electrolyte overflowing from the first partition 7 is blocked by the second partition 8. Thereby, the EC display element according to the present embodiment has a performance with excellent reliability.

  Further, by providing the sealing resin 9 on the opposite side of the second partition wall 8 from the first partition wall 7, it is difficult for the overflowing electrolyte to come into contact with the sealing resin 9. Thereby, the curing failure of the sealing resin 9 hardly occurs, and the substrates can be favorably bonded.

  In FIG. 1B, the counter electrode 5 and the like are shown thick for easy understanding of the invention, but in actuality, they are formed to about 100 nm. For this reason, the thickness of the counter electrode 5 is negligible with respect to the height (10 μm or more) of the first partition wall 7 and the second partition wall 8. Accordingly, even when the heights of the first partition wall 7 and the second partition wall 8 are uniform, the space between the first partition wall 7 and the counter substrate 6 or the space between the second partition wall 8 and the counter substrate 6 is used. There are almost no gaps. For this reason, the electrolyte hardly overflows from the second partition wall 8.

  Since the display substrate 1 needs to be able to visually recognize the EC material layer 3 from an observer, it needs to be transparent and desirably has a total light transmittance of 70% or more. More preferably, it has a total light transmittance of 80% or more. As the display substrate 1, a glass substrate, polystyrene (PS), polymethyl methacrylate (PMMA), styrene-methyl methacrylate copolymer (MS), polycarbonate (PC), cycloolefin polymer (COP), cycloolefin copolymer (COC) ), Polyethylene terephthalate (PET), polyethylene naphthalate (PEN), and other resin substrates can be used. If importance is attached to the flexibility, it is preferable to use a resin substrate. Among the resin substrates, PEN is preferable from the viewpoint of solvent resistance and dimensional stability.

  The display electrode 2 needs to be transparent for the same reason as described above, and desirably has a total light transmittance of 70% or more. More preferably, it has a total light transmittance of 80% or more. The display electrode 2 is made of a generally used metal oxide such as indium-tin oxide (ITO), antimony-doped tin oxide (ATO), antimony-doped zinc oxide (AZO), or zinc oxide (ZnO). A transparent conductive film may be used. Furthermore, conductive polymers such as conductive carbides such as single wall carbon nanotubes (SWCNT) and double wall carbon nanotubes (DWCNT), poly (3,4-ethylenedioxythiophene) (PEDOT), polyaniline derivatives, and polypyrrole derivatives. May be laminated so as not to decrease the transmittance.

Any material can be used for the EC material layer 3 as long as it is an electrochromic material that changes color by oxidation or reduction. Examples of this material include inorganic materials such as IrO _x , NiO _x , WO ₃ , MoO ₃ , and TiO ₂ . Further, in order to realize a discoloration with a good display quality, a π-conjugated conductive polymer is preferable. Examples of the π-conjugated conductive polymer include polyacetylene, poly-p-phenylene, poly-p-phenylene oxide, poly-p-phenylene sulfide, poly-p-phenylene vinylene, polynaphthylene vinylene, and polyisothianaphthene. , Polypyrrole, polythiophene, polythiophene vinylene, polyalkylthiophene, polyethylene dioxythiophene, polypropylene dioxythiophene, polyaniline, polyperiphthalene, polyoxadiazole, polythiazyl, polyacene, polyfuran, polyalkylfuran, polyselenophene, polytellophene , Polyaminopyrene, polyphenanthrene, polyimidazole, polyoxazole, polythiazole, polypyrazole, polyisoxazole, polyisothiazole, polybenzoto Azole, polyfluorene, polymers in which part of the main chain is substituted with boron, polypyridine, polypyridazine, polypyrimidine, polypyrazine, polymers in which some carbon of the aromatic ring represented by polyquinoline is substituted with nitrogen, polypyran Examples thereof include, but are not limited to, a conjugated polymer selected from the group of polymers in which a part of carbon of an aromatic ring is substituted with oxygen.

The electrolyte layer 4 may be any form of electrolyte. For example, in the case of a solution, since the ionic conductivity is large, the response speed can be increased and the drive voltage / current can be decreased. Moreover, if it is a gel and solid, it will be more difficult to leak, and a more reliable device can be provided. As a solution electrolyte, it is common to use a solution in which a lithium salt such as LiClO ₄ , LiAsF ₆ , LiPF ₆ , or LiBF ₄ is dissolved in an organic solvent such as acetonitrile, butyrolactone, or propylene carbonate.

  Recently, a normal temperature molten salt (ionic liquid) is sometimes used as the electrolyte layer 4 for the purpose of improving efficiency and safety. As the ionic liquid, any combination of the following anions and cations can be used. Examples of the anion include compounds having tetrafluoroborate, trifluoromethylsulfonylimide, pentafluoroethylsulfonylimide and the like. Examples of cations include imidazolium cations such as ethylmethylimidazolium and methylbutylimidazolium, pyrrolidinium cations such as butylmethylpyrrolidinium and butylpyridinium, and ammonium cations such as butyltrimethylammonium and diethylmethoxyethylmethylammonium. And the like. By using an ionic liquid, high-speed response and good memory performance can be realized.

As the solid electrolyte, a solid electrolyte such as Ta ₂ O ₅ or MgF ₂ is used. Further, as the polymer solid electrolyte, a matrix (matrix) polymer material in which a supporting electrolyte is dispersed may be used. As the matrix polymer, polyethylene oxide and polyethylene whose skeleton units are represented by — (C—C—O) _n —, — (C—C—N) _n —, and — (C—C—S) _n —, respectively. Examples include imine and polyethylene sulfide. These may be branched as a main chain structure. Polymethyl methacrylate, polyvinylidene fluoride, polycarbonate and the like are also preferable.

  When forming the electrolyte layer 4 with a solid electrolyte, it is preferable to add a required plasticizer to the matrix polymer. As a preferable plasticizer, when the matrix polymer is hydrophilic, water, ethyl alcohol, isopropyl alcohol and a mixture thereof are preferable. When the matrix polymer is hydrophobic, propylene carbonate, dimethyl carbonate, ethylene carbonate, γ-butyrolactone, acetonitrile, sulfolane, dimethoxyethane, ethyl alcohol, isopropyl alcohol, dimethylformaldehyde, dimethyl sulfoxide, dimethylacetamide, n -Methylpyrrolidone and mixtures thereof are preferred.

Further, as the supporting electrolyte dispersed in the matrix polymer, lithium salts such as LiCl, LiBr, LiI, LiBF ₄ , LiClO ₄ , LiPF ₆ , LiCF ₃ SO ₃ ; potassium salts such as KCl, KI, KBr; Sodium salts such as NaCl, NaI, and NaBr; or tetraalkylammonium salts such as tetraethylammonium borofluoride, tetraethylammonium perchlorate, tetrabutylammonium borofluoride, tetrabutylammonium perchlorate, and tetrabutylammonium halide. . The alkyl chain length of the quaternary ammonium salt (tetraalkylammonium salt) described above may be uneven.

  The counter electrode 5 may be transparent or opaque, and various metal materials, polymer materials, ceramic materials, semiconductor materials, and other conductive materials can be used. In general, it is preferable to use a metal material as the counter electrode 5 due to high electrical conductivity. Examples of metal materials include lithium, beryllium, magnesium, calcium, strontium, barium, boron, aluminum, gallium, indium, silver, gold, copper, nickel, palladium, platinum, chromium, molybdenum, tungsten, manganese, nickel, cobalt And their oxides and combinations or alloys thereof. Of course, the material of the counter electrode 5 is not limited to these. In particular, gold, silver, and copper are more preferable because they are highly conductive and chemically inert.

  Further, a highly reflective material may be laminated on the counter electrode 5. Thereby, the light reflection efficiency on the counter electrode 5 side of the light incident from the outside can be improved. And the visibility of EC display element can be improved.

  The counter substrate 6 may be transparent or opaque, and various materials can be used. For example, an insulating metal material, a polymer material, a ceramic material, or a semiconductor material can be used as the counter substrate 6. As the counter substrate 6, for example, a glass substrate such as a quartz glass substrate or a white plate glass substrate, a ceramic substrate, a paper substrate, or a wood substrate can be used. Furthermore, the counter substrate 6 is not limited to these, and the counter substrate 6 is an ester such as polyethylene naphthalate or polyethylene terephthalate, a cellulose ester such as polyamide, polycarbonate, or cellulose acetate, or a fluorine such as polyvinylidene fluoride or polytetrafluoroethylene-cohexafluoropropylene. Polymers, polyethers such as polyoxymethylene, polyacetals, polyolefins such as polystyrene, polyethylene, polypropylene, and methylpentene polymers, and synthetic resins such as polyimides such as polyimide-amide and polyetherimide can be used. When these synthetic resins are used as a substrate, it is possible to form a rigid substrate that does not easily bend, but it is also possible to have a flexible film-like structure. Of course, the same substrate as the display substrate 1 can be used as the counter substrate 6.

  The first partition wall 7 and the second partition wall 8 are made of a general resin such as an epoxy resin, an acrylic resin, a polyester resin, a polyether resin, a polyethylene resin, a polyimide resin, an inorganic oxide, or a hybrid material thereof. Can be used. In view of resistance to the electrolyte, a photo-curable epoxy resin is preferably used.

  The sealing resin 9 is not limited to an ultraviolet curable adhesive, and for example, a two-component adhesive such as a two-component epoxy adhesive can be used. An acrylic adhesive can be used as the ultraviolet curable adhesive.

  Next, a passive drive (simple matrix drive) method for the EC display element will be described. First, the display electrode 2 and the counter electrode 5 are sequentially selected in time series, and for example, a scanning voltage is applied to the display electrode 2 and a display voltage is applied to the counter electrode 5. As a result, a forward voltage / reverse voltage is applied to the pixel 10 where the selected display electrode 2 and counter electrode 5 intersect. Then, ions are doped / dedoped into the EC material of the EC material layer 3 through the electrolyte layer 4, and coloring / decoloring is repeated.

  Specifically, when a voltage is applied and the anion is doped, the EC material is oxidized. Then, when a voltage is applied in the reverse direction and the doped anion is dedoped, the oxidized EC material is reduced. Thus, a reversible oxidation-reduction reaction occurs by applying an electric field, and color development / decoloration associated therewith occurs. Since the EC material has retentivity, the color development / decolorization does not change even when the voltage is turned off. Thereby, the color of the EC material layer 3 changes for each pixel 10, and the display can be changed. That is, the display can be changed by independently driving the pixels 10 that are separately applied to C, M, and Y.

  Specifically, the light incident on the EC display element from the outside passes through the EC material layer 3 and is reflected on the counter substrate 6 side. Then, the reflected light again passes through the EC material layer 3 and is emitted to the viewing side. When light passes through the EC material layer 3 and is emitted to the viewing side, the color of the EC material layer 3 is displayed. For example, when C, M, and Y of the EC material layer 3 are colored by doping or dedoping, these are mixed and displayed in black. Then, by applying a voltage in the reverse direction, for example, when C, M, and Y of the EC material layer 3 are decolored, a background color such as white is displayed. Thus, the desired display can be obtained by oxidizing and reducing the EC material layer 3 for each pixel and changing the color for each pixel 10 arranged in a matrix.

  Further, the EC display element may be configured as shown in FIG. FIG. 2 is a schematic cross-sectional view showing another configuration of the EC display element according to the present embodiment. FIG. 2 is a schematic cross-sectional view at the same location as FIG.

  The EC display element shown in FIG. 2 has a configuration in which an adhesive layer 12 is added to the EC display element shown in FIG. The adhesive layer 12 is provided on at least one of the first partition wall 7 and the second partition wall 8. In FIG. 2, the adhesive layer 12 is provided on the first partition wall 7 and the second partition wall 8. By the adhesive layer 12, the first partition 7 and the counter substrate 6, and the first partition 7 and the counter electrode 5 are bonded. Similarly, the second partition 8 and the counter substrate 6, and the second partition 8 and the counter electrode 5 are bonded by the adhesive layer 12.

  By providing the adhesive layer 12, the electrolyte forming the electrolyte layer 4 is more reliably separated. That is, the electrolyte compartment is more clearly defined, and crosstalk due to the electrolyte is less likely to occur. In addition, the adhesive strength between the substrates is improved, and the electrolyte can be reliably separated even if the substrate is changed to a flexible substrate such as a plastic material. As the adhesive layer 12, an ultraviolet curable adhesive or a thermosetting adhesive is used, but an ultraviolet curable acrylic adhesive that is insoluble in the electrolyte is preferably used.

  In the present embodiment, a simple matrix drive EC display element has been described as an example from the viewpoint of manufacturing cost, but the present invention is not limited thereto. For example, the second partition may be formed in an active matrix drive EC display element. Even in this case, overflow of the electrolyte can be suppressed, and an EC display element having excellent performance can be obtained. Further, it is preferable to form the first partition 7 so as to surround each pixel 10 from the point of crosstalk, but the present invention is not limited to this. For example, the first partition 7 may be formed so as to surround the pixels 10 for one column. Even in this case, by forming the second partition wall, the electrolyte can be prevented from overflowing, and an EC display element having excellent performance can be obtained.

  Next, a manufacturing method of the EC display element shown in FIG. 2 will be described with reference to FIG. FIG. 3 is a schematic cross-sectional view showing a method for manufacturing an EC display element.

  First, the display electrodes 2 having a predetermined pattern are formed on the display substrate 1. A plurality of display electrodes 2 are formed linearly. Further, the method of laminating the display electrodes 2 is not particularly limited, but a known method can be applied. For example, vapor deposition, spin coating, slit coating, knife coating, lip coating, die coating, dip coating, spray coating, screen printing using solvents containing metals, metal oxides, conductive carbides, conductive polymers, etc. as inks And wet coating such as ink jet printing, flexographic printing, and gravure printing, and techniques such as vapor deposition, sputtering, and dry coating.

  Next, a first partition wall 7 and a second partition wall 8 are formed on the display electrode 2. The first partition wall 7 and the second partition wall 8 may be formed in separate steps, but are preferably formed simultaneously in the same step. This simplifies the manufacturing process and improves productivity. The first partition wall 7 and the second partition wall 8 may be formed by applying a polyester resin solution or the like on the display electrode 2 with a roll coater or a gravure coater, followed by drying and curing. A roll coater or a gravure coater is a type in which a predetermined coating thickness is obtained by transferring a coating solution that has been weighed in advance to a predetermined amount onto a substrate. Strictly speaking, since a certain amount of the coating liquid is applied to the substrate as it is, unevenness in the thickness of the substrate remains as it is after coating, but there is little loss of the coating liquid. The coating liquid needs low viscosity and is not suitable for thick film coating.

  Not only this but the 1st partition 7 and the 2nd partition 8 apply | coat resin before hardening on the display electrode 2, and harden the resin material in the state which pressed the jig | tool which has the unevenness | corrugation corresponding to the pixel 10. FIG. May be formed. Further, the first partition wall 7 and the second partition wall 8 may be formed by directly forming an array pattern of the pixels 10 using a method such as screen printing or ink jet. That is, the pattern of the first partition wall 7 and the second partition wall 8 may be directly formed. Screen printing is a method of obtaining a film by applying a coating liquid onto a patterned mesh screen by pressurizing with a squeegee and then transferring it onto a substrate. This is a method suitable for obtaining a thick film because a film can be formed by pressurizing a squeegee even if it has a high viscosity.

  Alternatively, the array pattern of the pixels 10 may be formed by a photolithography method using a photosensitive material that does not affect the display electrode 2. Among these forming methods, it is preferable to form the first partition wall 7 and the second partition wall 8 by photolithography using a photo-curable epoxy resin. In the present embodiment, the first partition wall 7 and the second partition wall 8 are formed directly on the display electrode 2 by photolithography.

  After forming the first partition wall 7 and the second partition wall 8, the EC material layer 3 is formed on the display electrode 2 in the recess surrounded by the first partition wall 7. As a method for forming the EC material layer 3, the display electrode 2 may be formed by immersing the display electrode 2 in an electrolyte solution in which the EC material is dissolved and performing electrolytic polymerization. In this case, the EC material layer 3 and the electrolyte layer 4 can be formed simultaneously. Not limited to this, the EC material solution may be directly formed by an ink jet method, an electrospinning method, a screen printing method, or the like. With the above process, the configuration shown in FIG.

  Next, an adhesive layer 12 is formed on the first partition wall 7 and the second partition wall 8. Examples of the method for forming the adhesive layer 12 include a transfer method, a screen printing method, and an ink jet method. Among these, the screen printing method is preferably used in terms of productivity and physical properties of the adhesive layer. In addition, the adhesive layer 12 is formed on the first partition wall 7 and the second partition wall 8, but is not limited thereto. For example, you may form in the part corresponding to the partition by the side of the opposing board | substrate 6 to bond.

  Then, a sealing resin 9 is formed on the display electrode 2. Since the sealing resin 9 may be formed only on the outermost periphery of the pixel 10, it is preferably formed by a dispenser method. As the sealing resin 9, at least a resin having higher adhesiveness than the material of the first partition wall 7 and the material of the second partition wall 8 is used.

  Then, the electrolyte layer 4 is formed in the first partition wall 7. As the electrolyte forming the electrolyte layer 4, it is desirable to use a liquid electrolyte (electrolytic solution) in terms of ease of filling the first partition wall 7 and response speed. Moreover, as the formation method, a wet coating method is preferable. Examples of the wet coating method include methods such as wet coating such as slit coating, knife coating, lip coating, die coating, dip coating, screen printing, inkjet method, flexographic printing, and gravure printing. Moreover, by using the inkjet method, the filling amount of the electrolyte in the recess surrounded by the first partition wall 7 can be controlled, and the extra filling can be reduced. Note that the adhesive layer 12, the sealing resin 9, and the electrolyte layer 4 may be formed in any order. With the above process, the configuration shown in FIG.

  Then, a counter electrode 5 having a predetermined pattern is formed on the counter substrate 6. A plurality of counter electrodes 5 are formed linearly. This can be formed by a method similar to that for the display electrode 2. Then, the display substrate 1 and the counter substrate 6 are bonded together by the sealing resin 9 and the adhesive layer 12. At this time, the display electrode 2 and the counter electrode 5 are bonded so as to face each other. Further, the display electrode 2 and the counter electrode 5 are bonded so as to cross each other. As a method of bonding them together, in the case of a rigid substrate such as a glass substrate, it is necessary to perform vacuum bonding in order to eliminate air entrainment in the atmosphere. In the case of a film substrate such as a plastic material, a laminating method can be used.

  Next, preferred specific examples of the present invention will be described together with comparative examples, but the above description and the following examples are illustrative and are not limited to these examples.

[Example 1]
A negative resist (TMMF-S2000: manufactured by Tokyo Ohka Kogyo Co., Ltd.) was applied on an ITO substrate (manufactured by Geomatek). Here, the ITO substrate corresponds to the display substrate 1 in which ITO as the display electrode 2 is formed in a predetermined pattern. Then, a photolithography process for exposing and developing the applied negative resist was performed. Thereby, the negative resist was patterned into a desired shape, and the first partition wall 7 and the second partition wall 8 having a thickness of 30 μm were formed. Next, the EC material layer 3 was formed by applying a dispersion of EC material on the ITO in the first partition wall 7 by an inkjet method. As this dispersion, a polyaniline dispersion (Aqua-PASS: manufactured by Mitsubishi Rayon Co., Ltd.) in which 20% by mass of polyaniline sulfonic acid and 80% by mass of pure water were dispersed was used. That is, a polyaniline film was formed as the EC material layer 3.

Next, an aqueous solution of ammonium hexafluorophosphate (NH ₄ -PF ₆ ) (manufactured by Wako Pure Chemical Industries, Ltd.) was injected onto the polyaniline film formed on the ITO in the first partition wall 7 by an inkjet method. Thereby, the electrolyte layer 4 was formed. Then, another ITO substrate was superimposed on the ITO substrate having the above-described configuration. Here, the other ITO substrate corresponds to the counter substrate 6 in which ITO as the counter electrode 5 is formed in a predetermined pattern. Here, the EC material layer 3 and the electrolyte layer 4 were sandwiched so that the ITOs face each other. An EC display element was produced as described above.

  In the manufactured EC display element, when the forward voltage / reverse voltage was inverted to the electrode corresponding to the desired pixel 10, the polyaniline film exhibited electrochromic properties. Specifically, the polyaniline film showed a color change from purple to yellow to green. Then, almost no color change other than the desired pixel due to crosstalk was observed. Further, the electrolyte did not overflow from the outer periphery of the fabricated element.

[Example 2]
In this example, an EC display element was produced in the same manner as in Example 1 except that the sealing resin 9 was formed. The sealing resin 9 was applied by using a dispenser so as to surround the second partition wall 8 on the side opposite to the first partition wall 7 with respect to the second partition wall 8. As the sealing resin 9, a photo-curable sealing resin (XNR5516ZHV: manufactured by Nagase ChemteX) was used. And like Example 1, after overlapping ITO board | substrates, it sealed by irradiating UV with the irradiation amount of 18 J / cm < ² > (wavelength 365nm) with respect to sealing resin 9 using UV irradiation apparatus. Resin 9 was cured. Further, when the sealing resin 9 was cured, the sealing resin 9 was not in contact with the electrolyte due to the second partition wall 8. For this reason, the sealing resin 9 can be completely cured, and no peeling occurs between the substrates even when a force is applied.

  In the manufactured EC display element, when the forward voltage / reverse voltage was inverted to the electrode corresponding to the desired pixel 10, the polyaniline film exhibited electrochromic properties. Specifically, the polyaniline film showed a color change from purple to yellow to green. Then, almost no color change other than the desired pixel due to crosstalk was observed. Further, the electrolyte did not overflow from the outer periphery of the fabricated element.

[Example 3]
In this example, an EC display element was produced in the same manner as in Example 2 except that the adhesive layer 12 was formed. The adhesive layer 12 was formed on the first partition wall 7 and the second partition wall 8 by screen printing. As the adhesive layer 12, ThreeBond 1549 (manufactured by ThreeBond) was used. Since the adhesive layer 12 was formed on the first partition wall 7 and the second partition wall 8 in addition to the EC display element of Example 2, the adhesion between the substrates was stronger than that of Example 2.

  Similarly to Example 2, in the manufactured EC display element, when the forward voltage / reverse voltage was inverted to the electrode corresponding to the desired pixel 10, the polyaniline film exhibited electrochromic properties. Specifically, the polyaniline film showed a color change from purple to yellow to green. Further, the color change other than the desired pixel due to crosstalk was not further observed than in Example 2. Further, the electrolyte did not overflow from the outer periphery of the fabricated element.

[Comparative Example 1]
In this comparative example, an EC display element was manufactured in the same manner as in Example 1 except that the second partition wall 8 was not provided. In the produced EC display element, excess electrolyte overflowed from the outer periphery of the first partition wall 7.

[Comparative Example 2]
In this comparative example, an EC display element was manufactured in the same manner as in Example 2 except that the second partition wall 8 was not provided. In the produced EC display element, the electrolyte overflowing from the first partition 7 was brought into contact with the sealing resin 9, so that the curing was insufficient, and peeling occurred when force was applied.

1 display substrate, 2 display electrode, 3 EC material layer, 4 electrolyte layer, 5 counter electrode,
6 counter substrate, 7 first partition, 8 second partition, 9 sealing resin, 10 pixels,
11 Display area, 12 Adhesive layer

Claims (9)

A first substrate;
A second substrate disposed opposite to the first substrate;
A first partition formed in a display region having a plurality of pixels between the first substrate and the second substrate;
A second partition wall that surrounds the display area and is formed of the same material as the first partition wall between the first substrate and the second substrate;
An electrochromic display element comprising: an electrolyte layer formed in a recess surrounded by the first partition wall.   The sealing resin according to claim 1, further comprising a sealing resin that is formed on a side opposite to the first partition with respect to the second partition, and bonds the first substrate to the second substrate. The electrochromic display element as described.   The electrochromic display element according to claim 1, wherein an adhesive layer is formed on at least one of the first partition and the second partition.   The electrochromic display element according to claim 1, wherein the electrolyte layer is formed of a liquid electrolyte. A first substrate;
A second substrate disposed opposite to the first substrate;
A first partition formed in a display region having a plurality of pixels between the first substrate and the second substrate;
A second partition wall surrounding the display area between the first substrate and the second substrate;
An electrolyte layer formed in a recess surrounded by the first partition;
An electrochromic display element, which is formed on a side opposite to the first partition with respect to the second partition, and includes a sealing resin for bonding the first substrate and the second substrate. Forming a first partition in a display region having a plurality of pixels on the first substrate, and forming a second partition surrounding the display region with the same material as the first partition;
Forming an electrolyte layer in a recess surrounded by the first partition;
A method for manufacturing an electrochromic display element, comprising: bonding the first substrate and the second substrate so that the electrolyte layer is sandwiched between the first substrate and the second substrate.   The manufacturing method of the electrochromic display element according to claim 6, wherein in the step of forming the first partition and the second partition, the first partition and the second partition are formed simultaneously. Method.   8. The method for manufacturing an electrochromic display element according to claim 6, wherein in the step of forming the electrolyte layer, the electrolyte layer is formed by applying an electrolyte by an ink jet method. Forming a first partition in a display region having a plurality of pixels on the first substrate, and forming a second partition surrounding the display region;
Forming an electrolyte layer in a recess surrounded by the first partition;
Through a sealing resin formed on the opposite side of the first partition to the second partition so as to sandwich the electrolyte layer between the first substrate and the second substrate, The manufacturing method of an electrochromic display element provided with the process of bonding a said 1st board | substrate and a said 2nd board | substrate.

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