JP2010072070A - Electrochemical display element and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochemical display element capable of stably rewiring display, while securing high definition of an image, utilizing electrochemical reaction, and to provide a method of manufacturing the element. <P>SOLUTION: In the electrochemical display element comprising a pair of substrates 2a and 2b having electrode layers 5a and 5b formed on surfaces, an electrolyte layer 3 charged between the substrates 2a and 2b, and a partition wall 4 provided between the substrates 2a and 2b to partition the electrolyte layer 3, the electrolyte layer 3 includes a substance which discolors through electrochemical oxidation or reduction; and a gap control member 6 is disposed between the partition wall 4 and substrate 2a and forms a predetermined gap. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an electrochemical display element capable of stably rewriting display while ensuring the definition of an image using an electrochemical reaction, and a method for manufacturing the same.

  Instead of the conventional method of printing and browsing document information and image information on a paper medium, in recent years, a cathode ray tube (hereinafter referred to as CRT), a plasma display (plasma display panel, hereinafter referred to as PDP), a liquid crystal display ( Opportunities for displaying and browsing document information and image information on a display device such as a Liquid Crystal Display (hereinafter referred to as LCD) are increasing. At this time, since the document information often needs to be displayed for a long time, these display devices are required to have excellent visibility and low power consumption.

  However, CRTs, PDPs, and LCDs that are generally used at present are display devices that modulate natural light or light emitted from natural light bodies, and such display devices are bright and easy to see, but have a large visual burden. I have the problem of high power consumption. Specifically, the visibility of the LCD decreases due to the angle at which the screen is viewed and the reflected light, and the visibility of the CRT decreases due to the occurrence of flickering. For this reason, when document information is displayed on these display devices and characters on the screen are read for a long time, compared to reading characters printed on a paper medium, the burden on human vision is greater and the eyes become tired. There was a problem. Further, from the viewpoint of low power consumption, it is desirable to have a memory characteristic that once retains a displayed image even in a non-powered state, and further, a low driving voltage is desirable. However, these display devices such as CRTs do not have this memory characteristic and cannot be said to have a low driving voltage.

  Accordingly, in recent years, development of an electrochemical display element that performs erasing / discoloring based on an electrochemical action has been actively performed as a display device having excellent visibility and low power consumption. Specific examples include electrochemical displays such as an electrochromic display (hereinafter referred to as ECD) and an electrodeposition display (hereinafter referred to as EDD). ECD applies a driving voltage to an electrochromic compound in which a colored state and a colorless state are reversibly changed by an electrochemical oxidation-reduction reaction, and repeatedly displays the color. EDD uses an electrolyte in which silver or a compound containing silver in the chemical structure is dissolved as a material that develops color by an electrochemical redox reaction, and is deposited by deposition of silver on the electrode and dissolution in the electrolyte. Display is repeated by decoloring.

  At this time, both the display principles of ECD and EDD can be driven at a low voltage, and have a memory characteristic that keeps a once displayed image even in a non-powered state. In addition, since the redox reaction on the electrode is used and the change in light absorption by the reactant alone is used, additional components such as a polarizing plate and a backlight are also poorer than LCD, which reduces costs and saves costs. It is very advantageous to process.

  However, since ECD and EDD require movement of ions to change the light absorption state, when dot matrix type display is performed in which a specific pixel region is colored to display dots, it is affected by the potential state of adjacent pixels. There was a thing. At this time, when ions move in a direction that should not be moved, a phenomenon that the display is changed in a place other than the rewritten pixel portion (hereinafter referred to as a bleeding phenomenon) occurs, and the resolution of the image is reduced. It was one. In addition, in order to perform display with higher definition, it is necessary to reduce the size per pixel and to form a narrow space between adjacent pixels. At this time, it is considered that the bleeding phenomenon is more likely to occur. In order to avoid such a phenomenon, as shown in Patent Document 1 and Patent Document 2, an attempt is made to limit the movement of ions by providing a partition wall that partitions an electrolyte layer between adjacent pixels and isolating each pixel region. It has been done.

  In the ECD described in Patent Document 1, a row of grooves is formed on one substrate between a pair of opposed substrates. A transparent electrode and a common electrode are formed on the other substrate surface where no groove is formed. With this configuration, when the two substrates are bonded together, the side surface of the groove formed in the substrate forms a partition, and the inside of the groove is electrically insulated. In addition, the groove is filled with an electrochromic solution, and by applying a voltage to the transparent electrode and the common electrode in the groove, a decolored display can be performed on a predetermined transparent electrode.

The ECD described in Patent Document 2 has a cell structure in which adjacent pixels are partitioned by a partition wall provided between opposing substrates. Electrode layers are formed on the surfaces of both substrates, and the cells are filled with an electrochromic compound that develops, decolors, or changes color when a voltage is applied. The cell structure formed by the partition walls prevents image blurring due to the flow of the electrochromic compound.
Japanese Patent Laid-Open No. 10-143125 JP 2007-178733 A Japanese Patent Laid-Open No. 2002-328401 JP 2004-537743 A

  At this time, the electrolyte filled in the groove or the cell needs to be completely in contact with the electrode or the color changing material formed on the electrode. If the electrolyte is not completely in contact with the electrode or the color-changing material and there is a gap between the electrolyte and the electrode, no oxidation or reduction reaction takes place in that area, and a discoloration display is performed. I can't. As a result, the display cannot be rewritten.

  However, in the ECD described in Patent Document 1 and Patent Document 2 in which adjacent pixels are separated by a partition, the partition and the substrate are bonded by an adhesive or thermal bonding to seal the opening of each cell. In this case, it is necessary to seal the opening of each cell by filling a fluid electrolyte in each cell partitioned by a groove or partition wall and then bonding the partition wall and the substrate by an adhesive or thermal bonding. It was. For this reason, when a cell having a gap between the electrolytic solution and the electrode is found after the substrates are bonded together, the electrolyte cannot be replenished in the cell.

  Further, the partition wall and the substrate are bonded by an adhesive or thermal bonding, and adjacent cells are completely isolated by the partition wall. For this reason, after bonding the opposing substrates, it was not possible to inject an electrolyte having fluidity into each empty cell by a vacuum injection method or the like.

  Accordingly, in view of the above problems, the present invention utilizes an electrochemical reaction, has excellent visibility, can be driven with low power consumption, and suppresses occurrence of a bleeding phenomenon in a display region, while preventing an electrolyte solution, an electrode, and the like. It is an object of the present invention to provide an electrochemical display element and a method for manufacturing the same that prevent the occurrence of chipping in a pixel region caused by a gap generated between the two.

  In order to solve the above problems, the electrochemical display element of the present invention includes a pair of substrates having an electrode layer formed on a surface thereof, an electrolyte layer filled between the substrates, and the electrode provided between the substrates. Partition walls that partition the electrolyte layer, the electrolyte layer having a substance that changes color by electrochemical oxidation or reduction, and a gap control member that forms a predetermined gap between the partition walls and the substrate. It is characterized by being.

  In the electrochemical display device having the above-described configuration, the gap control member is lower than the partition wall between the opposing substrates.

  According to the present invention, in the electrochemical display element configured as described above, the width of the gap control member is smaller than the width of the partition wall.

  According to the present invention, in the electrochemical display element configured as described above, the gap control member is spherical.

  The present invention also provides a method for manufacturing an electrochemical display element having the above-described configuration, wherein the gap control member is selectively disposed on the partition wall by an inkjet method using a solvent in which the gap control member is dispersed. It is characterized by including.

  According to the first configuration of the present invention, by applying a driving voltage to an electrolyte layer containing a substance that changes color by electrochemical oxidation or reduction, it is possible to perform decolorization based on an electrochemical action. . Accordingly, it is possible to provide a display element that has excellent visibility and can be driven with low power consumption. In addition, since the partition wall that partitions the electrolyte layer filled between the substrates is provided, the potential effect of adjacent pixels is blocked by the partition wall, and the bleeding phenomenon in which the display other than the rewritten pixel portion is changed can be prevented. Further, by providing a gap control member between the partition wall and the substrate, a gap is formed between the partition wall and the substrate. When the electrolytic solution having fluidity is injected after the opposing substrates are bonded together by the gap, the electrolytic solution passes through the gap and is uniformly filled into each cell partitioned by the partition walls. Therefore, in each cell, the electrolyte solution can be stably injected without generating a gap between the substrate and the electrolyte. For this reason, the oxidation-reduction reaction does not occur due to the gap between the electrolytic solution and the electrode, and a pixel region in which display cannot be rewritten does not occur. Note that the bleeding phenomenon of the display portion can be prevented by controlling the gap between the partition wall and the substrate so as not to be influenced by the potential of the adjacent pixels.

  According to the second configuration of the present invention, between the opposing substrates, when the height of the gap control member disposed between the partition walls and the substrate is larger than the height of the partition walls, the gap control member is formed between the partition walls and the substrate. The gap becomes large, and adjacent pixels are affected by the potential from this gap, and the bleeding phenomenon of the display portion is likely to occur. Therefore, it is necessary to prevent the occurrence of bleeding phenomenon by suppressing at least the height of the gap control member to be lower than the height of the partition wall and narrowing the gap between the partition wall and the substrate, and to suppress the display quality deterioration of the electrochemical display element.

  According to the third configuration of the present invention, when the gap control member is disposed on the observation-side substrate among the opposing substrates, the gap control member is visually recognized by the gap control member by forming the gap control member to be smaller than the partition wall. It is possible to prevent the hindrance of the property and to prevent the display quality of the electrochemical display element from deteriorating. For the purpose of avoiding the bleeding phenomenon, it is necessary to limit the height of the gap control member to ensure the partition wall at a predetermined height. For this reason, if the width of the partition wall is made too small, the strength of the partition wall is lowered, and there is a problem that the opposing substrates cannot be supported. Therefore, it is necessary to form the gap control member smaller than the width of the partition wall after forming a partition wall having a predetermined height with a predetermined width to ensure sufficient strength.

  According to the fourth configuration of the present invention, when the gap control member is arranged in a spherical shape, when the gap control member is dispersed and arranged, in the case of a spherical shape, it can be uniformly dispersed on the substrate. Become. Therefore, the manufacturing process of the electrochemical display element is simplified. Moreover, the hindrance to visibility can be minimized.

  According to the fifth configuration of the present invention, it is possible to arrange the gap control member at a desired position on the partition wall by arranging the gap control member by the ink jet method using the solvent in which the gap control member is dispersed. Thus, waste of members can be reduced. In addition, the gap control member can be selectively disposed at a position where visibility is not hindered as much as possible, such as a corner portion of a pixel.

  Hereinafter, an electrochemical display device which is an example of the electrochemical display element of the present invention will be described in detail with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing a part of an electrochemical display device 1 as an example of the electrochemical display element of the present invention, and FIG. 2 is an exploded perspective view showing the electrochemical display device 1 of FIG. FIG. 3 is a cross-sectional view taken along the line AA ′ of FIG. In FIG. 2, the observation-side substrate 2a is transmitted for the sake of explanation, and is shown by a broken line. 1 and 2, the electrodes 5a and 5b formed on the surfaces of the substrates 2a and 2b are not shown.

  As shown in FIGS. 1 to 3, the electrochemical display device 1 is filled with an electrolyte layer 3 between two opposing substrates 2 a and 2 b, and an electrolyte layer is formed by a partition wall 4 formed between the opposing substrates 2 a and 2 b. 3 is partitioned to form a plurality of cells. Here, in this embodiment, the “cell” means a single space formed by being partitioned by the partition walls 4. By separating the pixel regions by the partition walls 4, the movement of ions is limited.

  Moreover, as shown in FIG. 3, among the opposing substrates 2a and 2b, the observation-side substrate 2a disposed on the observation side of the electrochemical display device 1 is composed of a transparent substrate such as a glass substrate or a plastic substrate, and is observed. An electrode 5a is formed of a transparent conductive film typified by an ITO electrode on the surface of the side substrate 2a in contact with the electrolyte layer 3. Further, the non-observation side substrate 2b facing the observation side substrate 2a does not have to be a transparent substrate, and an electrode 5b such as a metal electrode is formed on the surface of the non-observation side substrate 2b in contact with the electrolyte layer 3. .

At this time, the electrolyte layer 3 is filled in each cell partitioned by the partition 4 formed between the electrode 5a and the electrode 5b. For example, when the display device 1 is ECD, the electrolyte layer 3 is composed of an electrolytic solution containing an electrochromic compound. When the display device 1 is EDD, the electrolyte layer 3 contains silver or a compound having silver in the chemical structure. It is comprised by the electrolyte solution to contain. For the purpose of improving the whiteness, a layer in which fine particles such as TiO ₂ are made porous using a binder such as a water-soluble polymer may be disposed in these electrolyte layers 3.

  In addition, the electrochemical display device 1 of the present invention can be applied to both a simple matrix type and an active matrix type. In the case of a simple matrix display device, the electrodes 5a and 5b are formed on the substrates 2a and 2b so that the linearly formed electrodes 5a and 5b are orthogonal to each other when the substrates 2a and 2b are bonded to each other. In the case of an active matrix display device, a transparent common electrode is formed on the observation-side substrate 2a, and a pixel electrode and a switching element such as a transistor array corresponding to the pixel electrode are formed on the non-observation-side substrate 2b.

  1 to 3 show a part of the electrochemical display device 1 of the present invention, and seals (not shown) are formed on the outer edges of the opposing substrates 2a and 2b. The seals are formed on both substrates 2a. It plays the role which seals the electrolyte layer 3 which has fluidity | liquidity, such as the electrolyte solution filled between 2b. In addition, for example, when the electrolytic solution is injected after the substrates 2a and 2b are bonded to each other by a vacuum injection method, an injection port is provided in a part of the seal formed on the periphery of the opposing substrates 2a and 2b. After the injection, the injection port is sealed.

  Here, in the electrochemical display device 1 according to the present invention, when a plurality of gap control members 6 are formed at predetermined positions on the partition 4 and the substrate 2a and the substrate 2b are bonded together, the partition 4 and the substrate 2a are interposed. A gap corresponding to the thickness of the gap control member 6 is formed. At this time, the gap is limited to a predetermined height in order to suppress the potential effect from the adjacent pixel region. Further, the gap control member 6 needs to have sufficient strength to maintain a gap formed between the substrate 2a and the partition wall 4, and can be specifically composed of spherical beads or protruding resin. . In FIG. 2, the observation side substrate 2a is bonded from above the partition wall 4 on which the gap control member 6 is disposed. However, the gap control member 6 is disposed in advance on a predetermined portion of the observation side substrate 2a, and the substrate 2a and the substrate 2b. May be pasted together. The formation method and material of the partition wall 4 and the gap control member 6 will be described in detail later.

  According to the electrochemical display element 1 having the above-described configuration, in each cell partitioned by the partition walls 4, by applying a driving voltage between the opposing electrodes 5a and 5b, electrochemical oxidation or electrolyte contained in the electrolyte layer 3 can be obtained. A substance that changes color due to reduction undergoes discoloration based on an electrochemical action. At this time, the electrochromic (EC) compound or electrodeposition (ED) compound that changes color due to electrochemical oxidation or reduction has an excellent memory effect and does not require an optical member such as a polarizing material. It is possible to provide an electrochemical display element 1 which is excellent in characteristics and can be driven with low power consumption.

  In addition, cells are formed for each pixel region by the partition walls 4 that partition the electrolyte layer 3 filled between the substrates 2a and 2b. As a result, the partition wall 4 blocks the potential effect from the adjacent pixel region, thereby preventing the phenomenon that the display other than the rewritten pixel portion changes (bleeding phenomenon). A gap is formed by a gap control member 6 disposed between the partition wall 4 and the substrate 2a. Thereby, the space in each adjacent cell is not completely isolated by the partition wall 4, but the adjacent cells are slightly conducted through the gap formed by the gap control member 6. Thereby, for example, when the electrolyte solution is injected from the injection port formed at the peripheral edge of the substrates 2a and 2b after bonding the opposing substrates 2a and 2b, the electrolyte solution spreads through the gap to the entire display unit, Each cell is uniformly filled with the electrolyte. Therefore, in each cell, the electrolyte solution can be filled in each cell so that the electrolyte solution having fluidity is in complete contact with the electrodes 5a and 5b formed in each cell.

  Note that this gap is formed so as to be controlled to a height that is not affected by the potential of the adjacent pixel region. Thereby, in all the cells, the electrochemical display element 1 can be easily manufactured without generating a gap between the electrodes 5a, 5b formed on the surfaces of the substrates 2a, 2b and the electrolyte layer 3. . In addition, a redox reaction does not occur due to the gap between the electrodes 5a and 5b and the electrolyte layer 3, and a pixel region where display cannot be rewritten does not occur.

  Further, as shown in FIG. 3, when the height of the gap control member 6 is sufficiently lower than the height of the partition wall 4 between the opposing substrates 2a and 2b, the gap formed by the gap control member 6 is interposed. Thus, the adjacent electrodes 5a are influenced by potentials, and the bleeding phenomenon does not occur. However, when the height of the gap control member 6 is larger than the height of the partition wall 4, the ratio of the gap between the partition wall 4 and the substrate 2a with respect to the space between the substrates 2a and 2b becomes too large. When a large gap is provided in this way, the adjacent electrodes 5a are influenced by potential through the gap, and the bleeding phenomenon is likely to occur. Therefore, it is necessary to suppress the display quality deterioration due to the bleeding phenomenon of the electrochemical display element 1 by forming the gap control member 6 lower than the partition wall 4 and limiting the gap between the partition wall 4 and the substrate 2a.

  In addition, as shown in FIG. 2, when the gap control member 6 is disposed on the observation-side substrate 2a, the gap control member 6 is formed with a width smaller than that of the partition wall 4 so that the visibility from the observation side is improved. The hindrance can be suppressed. The width of the partition wall 4 is preferably as narrow as possible in order to prevent the visibility from the observation side from being hindered. However, since the strength of the partition wall 4 is reduced when the width of the partition wall 4 is reduced, the gap control member 6 is made smaller than the width of the partition wall 4 while ensuring a sufficient width of the partition wall 4 that requires a predetermined height. Need to form. Thereby, the fall of the visibility of the electrochemical display apparatus 1 can be suppressed. Further, by making the gap control member 6 spherical, the manufacturing process of the electrochemical display device 1 can be simplified, and further the hindrance to visibility can be minimized.

  Further, when the gap control member 6 is disposed by an ink jet method using a solvent in which the gap control member 6 is dispersed, the gap control member 6 can be disposed at a desired position on the partition wall 4. Thereby, the waste of the gap control member 6 can be reduced. It is also possible to selectively dispose the gap control member 6 at a position where the visibility is not hindered as much as possible, at a corner portion of the pixel, or the like.

[Partition wall]
Hereinafter, each component of the electrochemical display element 1 of this invention is demonstrated in detail. In the electrochemical display element 1 of the present invention, the partition 4 has a structure surrounding a specific electrode region between opposing substrates. At this time, as shown in FIGS. 1 to 3, the electrolyte layer 3 is partitioned between the substrates 2 a and 2 b, and a cell is formed by a space surrounded by the partition walls 4. The electrodes 5a and 5b may be individually formed for each cell partitioned by the partition walls 4, or one electrode may be formed on the entire surface of the electrochemical display element 1. A material such as a thermoplastic resin, a thermosetting resin, or a photocurable resin can be used as the material constituting the partition 4. At this time, the precursor of the thermoplastic resin or thermoset can be selected from the group consisting of polyfunctional acrylates or methacrylates, vinyl ethers, epoxides, oligomers or polymers thereof, and the like. Of these, multifunctional acrylates and oligomers thereof are most preferred, and combinations of multifunctional epoxides and multifunctional acrylates can achieve desirable physical and mechanical properties and are very useful. The precursor of the photocurable resin is composed of a mixture of an epoxy acrylate, an oligomer such as urethane acrylate, a reactive diluent, and a photopolymerization initiator (benzoin-based, acetophenone-based, etc.). Moreover, the cross-sectional shape from the upper side of the partition 4 specifically has the structure shown in FIGS. 4A to 4F, but is not limited to these shapes.

[Method of forming partition wall]
In addition, as a method for forming the barrier rib structure, for example, a photosensitive resin composition to be a barrier rib is applied on a substrate by a method such as spin coating or slit coating, and a desired barrier rib pattern is formed through an exposure and development process. A method of obtaining a non-photosensitive resin composition on a substrate, forming a resist pattern using a photo process or a printing process, and then removing the resin composition by a sandblast etching method, direct screen printing Examples thereof include a method of directly printing a partition pattern by a method, and a method of aligning and bonding a resin sheet having a partition structure formed in advance. At this time, the material can be appropriately selected according to the forming method.

Hereinafter, as an example of a method for forming the partition walls 4, a method for forming the partition walls 4 using a photosensitive material will be described in detail. First, SU-83050 (manufactured by Kayaku Microchem Co., Ltd.), which is a negative photosensitive photoresist material, is applied by spin coating at a rotational speed of 4000 rpm on a non-observation side glass substrate on which metal electrodes are formed, and 100 ° C. On the hot plate for 30 minutes. After performing the pre-baking treatment, a parallel light exposure machine was used to irradiate ultraviolet rays of 400 mJ / cm ² through a photomask on which a partition wall pattern was formed, followed by heat treatment on a hot plate at 100 ° C. for 10 minutes. . Next, after heat treatment, development processing is performed using propylene glycol monomethyl ether acetate (PGMEA) solution, the photoresist material not irradiated with ultraviolet rays is removed, and rinse treatment is performed with isopropyl alcohol (IPA) solution. The partition can be formed on the non-observation side substrate by drying the liquid. By this formation step, the partition wall can be formed to a height of 40 μm, and the shape of the partition wall can be easily controlled by changing the photomask pattern to be used.

[Gap control member]
In the electrochemical display element 1 of the present invention, the gap control member 6 is disposed between the partition wall 4 and the substrate 2a, and forms a predetermined gap between the partition wall 4 and the substrate 2a. At this time, if the gap between the partition wall 4 formed by the gap control member 6 and the substrate 2a is too large, a bleeding phenomenon occurs. Therefore, the height of the gap control member 6 needs to be lower than the height of the partition wall 4. . In addition, the gap control member 6 needs to be formed smaller than the width of the partition wall 4 in order to prevent poor vision from the observation side.

[Gap Control Member Forming Method]
The gap control member 6 may be formed by patterning with a resin composition to form the gap control member 6 at a desired position or to arrange polystyrene or acrylic beads at a desired position. Thus, the gap control member 6 can be formed. At this time, fibers and beads of inorganic fine particles such as SiO ₂ , Al ₂ O ₃ , and TiO ₂ may be used.

Hereinafter, as an example of the formation method of the gap control member, a formation method by a photolithography method will be described in detail. First, Optmer NN700 (manufactured by JSR), which is a negative photosensitive resin composition, was applied on a glass substrate on the observation side on which a transparent electrode was formed by a spin coating method at a rotational speed of 3000 rpm, dried at 100 ° C. after drying under reduced pressure. Pre-bake for 3 minutes. Thereafter, exposure treatment is performed at 100 mJ / cm ² , development is then performed using potassium hydroxide, and then a heat treatment is performed at 230 ° C. for 30 minutes to form a gap control member. By this forming step, the gap control member can be formed to a height of 3.0 μm, and the shape of the gap control member can be easily obtained by changing the photomask pattern.

  When the beads are arranged at desired positions, the beads are uniformly dispersed and dispersed on the observation side glass substrate on which the partition walls 4 are formed by a dry spraying method generally used in the LCD manufacturing process. The gap control member 6 can also be arranged on 4.

  Further, for example, by using a piezo head KM512M (manufactured by Konica Minolta IJ Co., Ltd.) as an ink jet device, a few drops of the ink in which the beads are dispersed are sprayed at a desired position on the partition wall 4 by an ink jet method. The beads can be accurately placed on 4. At this time, the gap control member 6 can be accurately formed at a position where visibility is not hindered as much as possible. Therefore, this method can reduce the waste of beads used as the gap control member 6.

[Electrolyte layer]
In the electrochemical display element 1 of the present invention, the electrolyte layer 3 is composed of an electrolyte having fluidity. Usually, the electrolyte is classified into a liquid electrolyte and a polymer electrolyte. The polymer electrolyte is further classified into a solid electrolyte substantially composed of a solid compound, a gel electrolyte composed of a polymer compound and a liquid electrolyte. From the viewpoint of fluidity, the solid electrolyte has substantially no fluidity, while the gel electrolyte has fluidity intermediate between the liquid electrolyte and the solid electrolyte. Therefore, the electrolyte layer 3 referred to in the present invention refers to a liquid electrolyte having high viscosity and fluidity at room temperature. For example, the gel at 25 ° C. has a viscosity of 100 mPa · s to 1000 mPa · s. Or a high-viscosity electrolyte solution. In addition, the gel electrolyte as used in the field of this invention does not necessarily need to have the characteristic which produces the sol-gel change with temperature. The viscosity of the low-viscosity electrolyte of the present invention refers to an electrolyte solution having a viscosity at 25 ° C. of 0.1 mPa · s or more and less than 100 mPa · s, and the amount of the polymer binder to the electrolyte solvent is less than 10% by weight. Preferably there is.

[EC material]
The electrochromic compound (EC compound) used in the present invention is a compound that changes the light absorption state by accepting electrons, and an organic compound or a metal complex can be used. The organic compound is a pyridine compound or a conductive polymer. A styryl compound can be used, and various viologen compounds described in Patent Document 3, dyes described in Patent Document 4, and other known dyes can be used. Moreover, when using a leuco type | mold pigment | dye, you may use together a color developer or a decoloring agent as needed.

These materials may be applied directly on the electrode, or an oxide semiconductor nanostructure typified by TiO ₂ is formed on the electrode for the purpose of more efficiently accepting and receiving electrons, and an electrochromic compound is formed thereon. A structure in which coating and impregnation are performed by a method such as an inkjet method may also be used.

[ED material]
The electrodeposition compound (ED compound) used in the present invention is used by dissolving in an electrolyte solvent. Specific examples include silver or a compound containing silver in the chemical structure. For example, silver is a generic term for compounds such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compounds, and silver ions. There is no particular limitation on the state species of the layer such as the solid state, the solubilized state in the liquid, and the gas state, and the charged state species such as neutral, anionic, and cationic.

  The silver ion concentration contained in the electrolyte according to the present invention is preferably 0.2 mol / kg ≦ [Ag] ≦ 2.0 mol / kg. If the silver ion concentration is less than 0.2 mol / kg, it becomes a dilute silver solution, and the driving speed is delayed. If it is more than 2.0 mol / kg, the solubility is deteriorated and precipitation tends to occur during low-temperature storage, which is disadvantageous. It is.

[Method for producing electrochemical optical element]
Next, an example is shown about the manufacturing method of the electrochemical optical apparatus 1 used for this invention. The electrochemical display device 1 according to the present invention can be manufactured by injecting an electrolytic solution after bonding the observation side substrate 2a and the non-observation side substrate 2b on which the partition walls 4 are formed. At this time, in order to form a gap between the partition wall 4 and the observation-side substrate 2a, as shown in FIG. 2, after the gap control member 6 is disposed at a predetermined position on the partition wall 4, the opposing substrate 2a is replaced with the substrate. It can be formed by bonding to 2b. At this time, after forming the gap control member 6 at a predetermined position on the substrate 2a, the gap control member 6 may be aligned so as to contact the partition wall 4, and the substrate 2a and the substrate 2b may be bonded together. The cell gap between the substrates 2a and 2b is the sum of the height of the partition wall 4 and the height of the gap control member 6.

  Next, a seal portion for sealing the electrolytic solution is formed on the peripheral edge of one of the substrates 2a or 2b, and the substrates 2a and 2b are bonded together. At this time, an injection port for injecting the electrolyte into a part of the seal portion is formed. In general, a thermosetting or ultraviolet curable sealing material is used for the seal portion. Thereafter, an electrolyte solution is filled between the substrates from the electrolyte inlet, and finally, the cell gap between the substrates 2a and 2b is adjusted to an optimum gap, and the electrolyte inlet is sealed with a resin or the like.

  In the above process, the electrolyte to be filled has fluidity, and the electrolyte injected from the injection port diffuses uniformly throughout the gap formed between the substrate 2a and the partition wall 4. Therefore, the electrolyte can be filled so that the fluid electrolyte is in complete contact with both substrates in all the cells. Accordingly, it is possible to provide the electrochemical display device 1 that prevents the pixel region from being chipped due to the gap generated between the electrolyte and the electrode.

  Hereinafter, the present invention will be described in detail with reference to examples. In this example, EDDs according to the present invention 1 to 3 and EDDs according to comparative examples 1 to 4 were prepared, and the display quality of each EDD was compared and evaluated by simple matrix driving.

[Production of EDD according to Invention 1]
(Preparation of electrolyte)
First, in 2.5 g of dimethyl sulfoxide, 90 mg of sodium iodide and 75 mg of silver iodide were added and completely dissolved. Thereafter, 150 mg of polyvinyl pyrrolidone (average molecular weight 15000) was added and stirred for 1 hour while heating at 120 ° C. to prepare an electrolytic solution.

(Preparation of observation side substrate)
First, ITO, which is a transparent conductive film, is formed on a glass substrate by a sputtering method so as to have a thickness of 150 nm, and is patterned by a known photolithography method to form a stripe shape having an electrode width of 180 μm and an electrode pitch of 200 μm. Were formed on the substrate. Next, Optomer NN700 (manufactured by JSR), which is a negative photosensitive resin composition, was applied to the surface of the glass substrate on which the electrode was formed by a spin coating method at a rotational speed of 3000 rpm, dried under reduced pressure, and then subjected to 3 at 100 ° C. A pre-bake treatment was performed for a minute. Thereafter, exposure is performed at 100 mJ / cm ² , development is then performed using potassium hydroxide, and finally, a heat treatment is performed at 230 ° C. for 30 minutes, and a width of 10 μm and a height of 3 μm are provided between the stripe electrodes. A stripe-shaped gap control member was formed in parallel between the stripe-shaped electrodes to produce an observation side substrate.

(Preparation of non-observation side substrate)
First, a silver-palladium electrode (Pd: 2 wt%), which is a metal electrode, is formed on a glass substrate so as to have a film thickness of 200 nm by a sputtering method, and is patterned by a known photolithography method, and an electrode width of 180 μm. A striped electrode having an electrode pitch of 200 μm was obtained. Next, SU-83050 (manufactured by Kayaku Microchem Co., Ltd.), a negative photosensitive photoresist, was applied on the glass substrate on the side where the metal electrode was formed by a spin coating method at a rotational speed of 4000 rpm, and a hot plate at 100 ° C. A pre-bake treatment was performed for 30 minutes above. Next, after pre-baking treatment, a parallel light exposure machine is used to irradiate 400 mJ / cm ² of ultraviolet rays through a photomask having a partition wall pattern formed thereon, followed by heat treatment on a hot plate at 100 ° C. for 10 minutes. I did it. Next, after the heat treatment, development processing was performed using a propylene glycol monomethyl ether acetate (PGMEA) solution to remove the photoresist material not irradiated with ultraviolet rays. Finally, after rinsing with isopropyl alcohol (IPA) liquid, the liquid was dried to form a barrier on the substrate. At this time, the cross-sectional shape of the partition wall was as shown in FIG. 4A, and the partition wall width was 20 μm.

(Formation of scattering layer)
Next, 20% by mass of titanium oxide was mixed with an ultrasonic disperser in an isopropanol solution containing 2% by mass of polyvinyl alcohol (average polymerization degree 3500, saponification degree 87%) by the dispenser method. A scattering layer was formed in each cell by applying the liquid and drying by heating. At this time, the scattering layer was formed to have a thickness of about 10 μm. Furthermore, in order to seal the electrolytic solution, the peripheral edge of the substrate was sealed with an epoxy-based ultraviolet curable resin except for the injection port.

(Injection of electrolyte)
Next, after aligning the prepared observation side substrate and the non-observation side substrate so that the striped electrodes are orthogonal to each other and bonding the both substrates, the cell gap between the two substrates is increased by heating and pressing. An empty cell was prepared with uniform adjustment. Next, the prepared electrolytic solution was vacuum-injected into an empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin, thereby producing an EDD according to the present invention 1.

[Production of EDD according to Invention 2]
In the EDD manufacturing process according to the first aspect of the present invention, the observation side substrate is not provided with a gap control member made of a resin structure, and the number of micropearls SP-203 (manufactured by Sekisui Chemical Co., Ltd.) is 50 / mm by the dry spray method. The EDD according to the second aspect of the present invention was manufactured.

[Production of EDD according to Invention 3]
In the same manufacturing process as the EDD according to the first aspect of the invention, KM512M (manufactured by Konica Minolta IJ) is used as a piezo-type inkjet head, and Micropearl SP-203 (3 μm) is used as an ink in ethylene glycol 50 and water 50. An EDD according to the third aspect of the present invention was manufactured by using a dispersion liquid added by 5 wt% and injecting it to the corner of the partition wall of the non-observation side substrate to form a gap control member.

[Production of EDD according to Comparative Example 1]
In the same manufacturing process as the EDD according to the invention 1, the gap control member is not formed on the observation side substrate, and the non-observation side substrate is bonded to create an empty cell, which is then filled with an electrolytic solution, and a comparative example 1 was prepared.

[Production of EDD according to Comparative Example 2]
In the same manufacturing process as the EDD according to the first aspect of the present invention, SU-83050 (manufactured by Kayaku Microchem Co., Ltd.), which is a negative photosensitive photoresist, is rotated on the glass substrate on the side on which the metal electrode is formed. It apply | coated by several 3000 rpm by the spin coat method, and prebaked for 30 minutes on the 100 degreeC hotplate. Next, after pre-baking treatment, a parallel light exposure machine is used to irradiate 400 mJ / cm ² of ultraviolet rays through a photomask having a partition wall pattern formed thereon, followed by heat treatment on a hot plate at 100 ° C. for 10 minutes. I did it. Next, after the heat treatment, development processing was performed using a propylene glycol monomethyl ether acetate (PGMEA) solution to remove the photoresist material not irradiated with ultraviolet rays. Finally, after rinsing with isopropyl alcohol (IPA) liquid, the liquid was dried to form a gap control member on the observation side substrate. At this time, the gap control member was formed in a stripe shape having a height of 45 μm and a width of 15 μm. In addition, on the non-observation side, an EDD according to Comparative Example 2 was manufactured by the same manufacturing process as the EDD according to the present invention 1 except that the seal member was changed to 100 μm.

[Production of EDD according to Comparative Example 3]
In the same manufacturing process as the EDD according to the first invention, the EDD according to Comparative Example 3 was manufactured so that the height of the partition wall formed on the non-observation side substrate was 10 μm.

[Production of EDD according to Comparative Example 4]
In the same manufacturing process as the EDD according to the first invention, the EDD according to Comparative Example 4 was manufactured so that the width of the gap control member formed on the observation side substrate was 30 μm.

[Evaluation 1]
In the EDD according to the first aspect of the present invention and the EDD according to Comparative Example 1, a voltage of -1.5 V is applied to the ITO electrode formed on the observation side substrate, and the voltage of the metal electrode formed on the non-observation side substrate Was set to 0 V, and voltage was applied to all the pixels for 1 second, and the entire display area was set to black display. At this time, the display area of the EDD that became black display in the entire display area was measured with a spectrocolorimeter (CM-3700d: manufactured by Konica Minolta Sensing Co., Ltd.) in the D65 light source and regular reflection removal mode. as a result,
EDD Y value according to the present invention 1 = 4.5
EDD Y value according to Comparative Example 1 = 5.8
The value was obtained. Further, when the surface of the display area of the EDD according to Comparative Example 1 was observed with a microscope, bubbles were observed in a large number of pixels, and the display could not be rewritten, that is, could not be made black.

[Evaluation 2]
In the EDD according to the present invention 1 and the EDD according to comparative example 2, DC voltages of 0V and −1.5V are alternately applied to the adjacent stripe-shaped ITO electrodes formed on the observation side substrate. At the same time, all the voltages of the striped metal electrodes formed on the non-observation side substrate were set to 0 V, and a striped image was displayed in the display area. At this time, the display area of the EDD according to the present invention 1 and Comparative Example 2 was measured with a spectrocolorimeter (CM-3700d: manufactured by Konica Minolta Sensing) in a D65 light source and a regular reflection removal mode. as a result,
EDD Y value according to the present invention = 18.5
EDD Y value according to Comparative Example 2 = 16.2
The value was obtained. Further, when the surface of the display region of the EDD according to Comparative Example 2 was observed with a microscope, blackened silver was deposited on the ITO electrode to which 0 V was applied due to the bleeding phenomenon.

[Evaluation 3]
When the surface of the display area of the EDD according to Comparative Example 3 was observed with a microscope, a part of the panel was not formed with a partition which was thought to be caused by tilting due to insufficient strength of the partition, and a display defect occurred. Observed.

[Evaluation 4]
As a result of measuring the contrast ratio of the EDD according to the present invention 1 and the EDD according to the comparative example 4, the contrast ratio of the EDD according to the present invention 1 was 12, whereas the contrast ratio of the EDD according to the comparative example 4 was It was 8.

[Evaluation 5]
As a result of measuring the contrast ratio of the EDD according to the present invention 2, the contrast ratio of the EDD according to the present invention 2 was 15.

[Evaluation 6]
As a result of measuring the contrast ratio of the EDD according to the present invention 3, a contrast ratio equivalent to that of the EDD according to the present invention 2 was obtained. In addition, the consumption of the micropearl used when producing the EDD according to the present invention 3 was about 1/5 of the consumption of the micropearl used when producing the EDD according to the present invention 2. .

FIG. 2 is a perspective view showing a part of the electrochemical display device of the first embodiment. FIG. 2 is an exploded perspective view showing the electrochemical display device shown in FIG. 1 in an exploded manner. These are sectional drawings in A-A 'as described in the electrochemical display apparatus of FIG. (A)-(f) is a top view which shows the shape of a partition.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrochemical display element 2 Board | substrate 2a Observation side board | substrate 2b Non-observation side board | substrate 3 Electrolyte 4 Partition 5 Electrode 5a Electrode (observation side)
5b Electrode (non-observation side)
6 Gap control member

Claims (5)

  A pair of substrates each having an electrode layer formed on the surface; an electrolyte layer filled between the substrates; and a partition wall provided between the substrates and partitioning the electrolyte layer, wherein the electrolyte layer is electrochemical An electrochemical display element comprising a substance that changes color by oxidation or reduction, and a gap control member that forms a predetermined gap between the partition and the substrate.   The electrochemical display element according to claim 1, wherein a height of the gap control member is lower than a height of the partition wall between the opposing substrates.   The electrochemical display element according to claim 1, wherein a width of the gap control member is smaller than a width of the partition wall.   The electrochemical display element according to any one of claims 1 to 3, wherein the gap control member is spherical.   5. The method for manufacturing an electrochemical display device according to claim 1, wherein the gap control member is selectively formed on the partition wall by an inkjet method using a solvent in which the gap control member is dispersed. The manufacturing method of the electrochemical display element characterized by including the process arrange | positioned in.

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