JP2008116786A - Display element and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a display element of which the white color tone variation at repetitive driving is reduced, focusing on a display element of an ED (electrodeposition) system which can be driven with a simple member constitution and at a low voltage and has high display contrast and white display reflectance. <P>SOLUTION: The display element holds an electrolyte containing silver or a silver compound between counter electrodes and performs driving operation of the counter electrodes so that dissolution and deposition of silver are generated, the display element is characterized in that at least one electrode of the counter electrodes is bonded to a compound having a mercapto group, represented by general formula (I) via a siloxane bond (Si-O). General formula (I) is (R)<SB>n</SB>-Si(A)<SB>3-n</SB>-(B), wherein R is a 1-8C alkyl group, A represents an alkoxy group or a halogen atom, B represents a substituent containing an SH group, and n represents an integer of 0-2. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrochemical display element using silver dissolution precipitation and a method for manufacturing the same.

  In recent years, with the increase in the operating speed of personal computers, the spread of network infrastructure, the increase in capacity and price of data storage, information such as documents and images provided on printed paper on paper has become easier to use electronic information. Opportunities to obtain and browse electronic information are increasing more and more.

  As a means for browsing such electronic information, a conventional liquid crystal display or CRT, and in recent years, a light emitting type such as an organic EL display is mainly used. In particular, when the electronic information is document information, it is relatively long time. It is necessary to pay close attention to this browsing means, and these actions are not necessarily human-friendly means. Generally, as a drawback of light-emitting displays, eyes flicker due to flickering, inconvenient to carry, reading posture is limited It is known that it is necessary to adjust the line of sight to a still screen, and that power consumption increases when read for a long time.

  As a display means that compensates for these drawbacks, a reflection type display that uses external light and does not consume power for image retention (memory type) is known, but has sufficient performance for the following reasons. It's hard to say.

  That is, the method using a polarizing plate such as a reflective liquid crystal has a low reflectance of about 40% and is difficult to display white, and many of the production methods used for producing the constituent members are not easy. In addition, the polymer dispersed liquid crystal requires a high voltage and utilizes the difference in refractive index between organic substances, so that the resulting image has insufficient contrast. In addition, the polymer network type liquid crystal has problems such as a high voltage and a complicated TFT circuit required to improve the memory performance. In addition, a display element based on electrophoresis requires a high voltage of 10 V or more, and there is a concern about durability due to electrophoretic particle aggregation. In addition, the electrochromic display element can be driven at a low voltage of 3 V or less, but the color quality of black or color (yellow, magenta, cyan, blue, green, red, etc.) is not sufficient, and the memory property is low. In order to ensure, there is a concern that the display cell requires a complicated film configuration such as a vapor deposition film.

  An electrodeposition (hereinafter abbreviated as ED) method that utilizes dissolution or precipitation of a metal or a metal salt is known as a display method that eliminates the drawbacks of the above-described methods. The ED method can be driven at a low voltage of 3 V or less, has advantages such as a simple cell configuration, excellent black-white contrast and black quality, and various methods have been disclosed (for example, Patent Document 1). -3)).

As a result of detailed examination of the techniques disclosed in each of the above-mentioned patent documents, the inventor has found that there is a problem that white tone fluctuations during whitening occur in the conventional technique when repeated driving is repeated. did.
U.S. Pat. No. 4,240,716 Japanese Patent No. 3428603 JP 2003-241227 A

  The present invention has been made in view of the above problems, and its purpose is to repeatedly drive by focusing on an ED display element that can be driven with a simple member configuration, low voltage, and has high display contrast and white display reflectance. It is an object of the present invention to provide a display element in which a change in white color tone is reduced.

  The above object of the present invention is achieved by the following means.

  1. A display element that holds an electrolyte containing silver or a silver compound between counter electrodes and performs a driving operation of the counter electrode so as to cause dissolution and precipitation of silver, and includes at least one electrode of the counter electrodes Is bonded to the compound having a mercapto group represented by the general formula (I) through a siloxane bond (Si—O).

Formula (I) (R) _n -Si (A) _3-n- (B)
(Here, R represents an alkyl group having 8 or less carbon atoms, A represents an alkoxy group or a halogen atom, B represents a substituent containing an SH group, and n represents an integer of 0 to 2.) .)
2. 2. The display device according to 1 above, wherein the compound of the general formula (I) has a triazine ring.

  3. The electrolyte contains at least one compound represented by the following general formula (1) or (2) and at least one compound represented by the following general formula (3) or (4). 3. The display element according to 1 or 2 above.

[Wherein, L represents an oxygen atom or CH ₂ , and R _{1 to} R ₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group. ]

[Wherein, R ₅ and R ₆ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group or an alkoxy group. ]
General formula (3)
R ₇ -S-R ₈
[Wherein R ₇ and R ₈ each represents a substituted or unsubstituted hydrocarbon group. However, when a ring containing an S atom is formed, an aromatic group is not taken. ]

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents an atom or an atomic group constituting a nitrogen-containing heterocycle together with -C = N-. n represents an integer of 0 to 5, and R ₉ represents a hydrogen atom or a substituent. ]
4). The molar concentration of halogen ions or halogen atoms contained in the electrolyte was [X] (mol / kg), and the total molar concentration of silver or silver of the silver compound contained in the electrolyte was [Ag] (mol / kg). When satisfy | filling the conditions prescribed | regulated by the following Formula (1), The display element as described in any one of said 1-3 characterized by the above-mentioned.

Formula (1): 0 ≦ [X] / [Ag] ≦ 0.01
5. 5. The method for producing a display element according to any one of 1 to 4, wherein a solution containing the compound represented by the general formula (I) is brought into contact with at least one electrode of the counter electrode, and the general formula A method for producing a display element, wherein the compound represented by (I) is bonded to the electrode through a siloxane bond (Si-O).

6). A method of manufacturing a display element that holds an electrolyte containing silver or a silver compound between counter electrodes, and performs a driving operation of the counter electrode so as to cause dissolution and precipitation of silver.
A solution containing the compound represented by the general formula (I) is brought into contact with the substrate, and the substrate on which the compound represented by the general formula (I) is bonded through a siloxane bond (Si—O) is irradiated with light. A method for manufacturing a display element, wherein a region where a metal can be bonded and a region where a metal cannot be bonded are separated to produce at least one type of counter electrode.

Formula (I) (R) _n -Si (A) _3-n- (B)
(Here, R represents an alkyl group having 8 or less carbon atoms, A represents an alkoxy group or a halogen atom, B represents a substituent containing an SH group, and n represents an integer of 0 to 2.) .)
7). 7. The method for manufacturing a display element according to 6, wherein a solution containing a metal is brought into contact with the substrate after the light irradiation, and the metal is bonded to a region where the metal can be bonded.

  8). 8. The method for manufacturing a display element according to 7, wherein a plating process is performed on a substrate in which a metal is bonded to a region where the metal can be bonded, and a plating film is selectively formed in a light irradiation region.

  By means of the above-described means of the present invention, a display element with a simple member configuration, which can be driven at a low voltage, and has a high display contrast and a high white display reflectance, in which variation in white color tone during repeated driving is reduced. Can be provided.

  A display element of the present invention is a display element that holds an electrolyte containing silver or a silver compound and that drives the counter electrode so as to cause dissolution and precipitation of silver, and includes at least one kind of the counter electrode. The mercapto compound is bonded to the electrode through an O atom of the —O—Si— group.

  The “electrolyte” generally refers to a substance that dissolves in a solvent such as water and exhibits ionic conductivity in a solution (hereinafter referred to as “narrowly defined electrolyte”). A mixture containing other metals, compounds, etc., regardless of whether it is an electrolyte or a non-electrolyte, is also referred to as an electrolyte (“broadly defined electrolyte”).

  In the configuration of the display element of the present invention, the reason why the durability of the transparent electrode is improved by coating the electrode with a compound containing a mercapto group is as follows. 1. The dissolution of the transparent electrode is reduced by the bond between the metal contained in the electrode and the compound contained in the electrolyte. 2. Hydrophobizing the defect site on the electrode with a coating to prevent contact with the electrolyte; Furthermore, a compound containing a mercapto group can form a complex with silver ions in the electrolyte, and the silver redox reaction on the complex surface with silver ions becomes more dominant than the silver redox reaction on the electrode surface. And the like.

  Hereinafter, the present invention and components will be described in detail.

[Silver or silver compound]
The silver or silver compound according to the present invention is silver or a compound containing silver in the chemical structure, such as silver oxide, silver sulfide, metallic silver, silver colloidal particles, silver halide, silver complex compound, silver ion, etc. It is a general term for compounds, and there are no particular limitations on the state species of the phase such as the solid state, the solubilized state in liquid and the gas state, and the charged state species such as neutral, anionic and cationic.

[Basic structure of display element]
In the display element of the present invention, the ED display portion is provided with one corresponding counter electrode. The electrode 1 which is one of the counter electrodes close to the ED display portion is provided with a transparent electrode such as an ITO electrode, and the other electrode 2 is provided with a metal electrode such as a silver electrode. An electrolyte having silver or a compound containing silver in the chemical structure is held between the electrode 1 and the electrode 2. By applying a voltage of both positive and negative polarity between the counter electrodes, the electrode 1 and the electrode 2 are Thus, a redox reaction of silver is carried out, and the reduced silver image and the transparent transparent silver state can be switched reversibly.

(Compound represented by formula (I))
Formula (I) (R) n-Si (A) _3-n- (B)
R is an alkyl group having 8 or less carbon atoms, preferably a lower alkyl group having 1 to 4 carbon atoms, and n represents an integer of 0 to 2. A is an alkoxy group or a halogen atom, and the alkoxy group is, for example, a lower alkoxy group (1 to 4 carbon atoms) such as methoxy, ethoxy, propoxy, or butoxy, and particularly preferably a methoxy or ethoxy group. Of the halogen atoms, a chlorine atom is preferred. B represents a substituent containing an SH group. B is not particularly limited and may be an aliphatic or (hetero) aromatic group containing at least one, preferably two or more mercapto groups in the structure.

  Examples of these include the following.

(A-1) Triethoxysilyl-propylamino-triazine-dithiol (A-2) γ-mercaptopropyl-trimethoxysilane (A-3) 3-mercaptopropylmethyldimethoxysilane (A-4) mercaptopropyltriethoxysilane (A-5) γ-mercaptopropylmethyldimethoxysilane (A-6) γ-mercaptopropyl-trichlorosilane Among the compounds represented by the above general formula (I), a compound having a triazine ring is particularly preferable. A-1) Triethoxysilyl-propylamino-triazine-dithiol is a mercaptoamine corresponding to γ-propyltriethoxysilane, in this case 1-amino-3,5-dimercaptotriazine (Japanese Patent Laid-Open No. 2001-316872 etc.) Can be easily obtained by condensation reaction It is.

According to a fifth aspect of the present invention, there is provided the compound represented by the general formula (I) by bringing a solution containing the compound represented by the general formula (I) into contact with at least one kind of the counter electrode. The silyl group (—Si (A) ₃ ) contained is reacted and bonded to the electrode via a siloxane bond (Si—O). As a solvent of the solution containing the compound represented by the general formula (I), any solvent species can be used as long as the solvent can dissolve the compound represented by the general formula (I), such as water, an aqueous solvent, and an organic solvent. However, from the viewpoint of handling properties and drying properties, the use of an alcohol solvent is preferred, and ethanol and isopropanol are more preferred.

  Examples of the pretreatment of the electrode that is brought into contact with the solution containing the compound represented by the general formula (I) include alcohol cleaning, acid or alkali liquid cleaning, surfactant liquid cleaning, atmospheric pressure plasma processing, UV ozone processing, and the like. A known processing method can be used. Of these, it is preferable to perform UV ozone treatment after washing with an alkaline solution.

  The manufacturing method of Claim 6 of this invention is a manufacturing method of the metal electrode which can be used for preparation of the 2nd metal electrode facing a transparent electrode.

  This manufacturing method is characterized in that a substrate to which a compound represented by the general formula (I) is bonded is irradiated with light to separate a region where a metal can be bonded from a region where a metal cannot be bonded.

  Here, the substrate is not selected as long as it is reactive with alkoxysilanes and has a group such as a hydroxy group on the surface which is bonded to the alkoxysilane via a siloxane bond (Si—O). For example, a substrate having a layer on the surface of which a group having reactivity with the alkoxylane or the like such as a hydroxy group is present, or the surface of the substrate itself may be such as metal oxide such as silicon oxide. And a substrate having a film composed of a metal oxide such as

  Moreover, the metal film surface and the resin film surface may be treated with a high pH alkali to hydrolyze a part of the surface, or may be a surface hydrophilized by ozone treatment or the like. Among the above methods, when an alkaline aqueous solution is used, pH> 5 and pH <12 are preferable. Of course, the surface of the metal oxide or the like may be subjected to an alkali treatment to further increase the number of hydroxyl groups on the surface.

  After the compound containing the mercapto group is bonded to these surfaces, light irradiation is performed to separate a region where the metal can be bonded and a region where the metal cannot be bonded, and the light irradiation is preferably UV light irradiation. It is presumed that the region separation can be performed by changing the SH group in the compound represented by the general formula (I) to -SS- by irradiation with light and eliminating the metal binding site on the surface. The distinction between the light irradiation part and the light non-irradiation part may be exposure through a photomask or patterning using a scanning laser beam.

  A seventh aspect of the present invention is characterized in that a metal-containing solution is brought into contact with the substrate after the light irradiation, and the metal is bonded to a region where the metal can be bonded. The solution containing metal may be any solution in which metal ions are dissolved, but is preferably an aqueous solution containing gold, silver, copper, chromium, and palladium.

  According to an eighth aspect of the present invention, a plating process is performed on a substrate in which a metal is bonded to a region where the metal can be bonded, and a plating film is selectively formed in a light irradiation region. By performing such a process, it is possible to perform a plating process at a position selectively separated by light exposure, omitting a complicated process such as photolithography necessary for patterned plating, and easily and quickly. Thus, a plating pattern can be obtained. In addition, since the anchor portion is bonded by a —O—Si group, a plating film having a good strength with a film can be obtained.

  Thereby, the metal electrode which consists of a desired pattern can be obtained by plating.

(Porous white scattering layer)
In this invention, you may have a porous white scattering layer from a viewpoint of raising a display contrast and a white display reflectance more.

  The porous white scattering layer applicable to the present invention can be formed by applying and drying an aqueous mixture of an aqueous polymer and a white pigment that is substantially insoluble in the electrolyte solvent.

  Examples of the white pigment applicable in the present invention include titanium dioxide (anatase type or rutile type), barium sulfate, calcium carbonate, aluminum oxide, zinc oxide, magnesium oxide and zinc hydroxide, magnesium hydroxide, magnesium phosphate, Magnesium hydrogen phosphate, alkaline earth metal salt, talc, kaolin, zeolite, acidic clay, glass, organic compounds such as polyethylene, polystyrene, acrylic resin, ionomer, ethylene-vinyl acetate copolymer resin, benzoguanamine resin, urea-formalin resin, A melamine-formalin resin, a polyamide resin, or the like may be used alone or in combination, or in a state having voids that change the refractive index in the particles.

In the present invention, among the white particles, titanium dioxide, zinc oxide, and zinc hydroxide are preferably used. In addition, titanium dioxide surface-treated with inorganic oxides (Al ₂ O ₃ , AlO (OH), SiO _2, etc.), in addition to these surface treatments, trimethylolethane, triethanolamine acetate, trimethylcyclosilane, etc. Titanium dioxide subjected to organic treatment can be used.

  Of these white particles, it is more preferable to use titanium oxide or zinc oxide from the viewpoint of coloring prevention at high temperature and the reflectance of the element due to the refractive index.

  In the present invention, examples of the water-based polymer that does not substantially dissolve in the electrolyte solvent include a water-soluble polymer and a polymer dispersed in the water-based solvent.

Examples of water-soluble compounds include proteins such as gelatin and gelatin derivatives, cellulose derivatives, natural compounds such as starch, gum arabic, dextran, pullulan, and carrageenan, and the like, polyvinyl alcohol, polyvinyl pyrrolidone, acrylamide polymers, and the like. Examples include synthetic polymer compounds such as derivatives. As gelatin derivatives, acetylated gelatin, phthalated gelatin, polyvinyl alcohol derivatives as terminal alkyl group-modified polyvinyl alcohol, terminal mercapto group-modified polyvinyl alcohol, and cellulose derivatives include hydroxyethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and the like. It is done. Furthermore, Research Disclosure and those described in pages (71) to (75) of JP-A No. 64-13546, US Pat. No. 4,960,681, JP-A No. 62-245260, etc. superabsorbent polymers described, namely -COOM or -SO ₃ M (M is a hydrogen atom or an alkali metal) homopolymer or a vinyl monomer together or with other vinyl monomers (e.g., sodium methacrylate in the vinyl monomer having a methacrylic acid Copolymers with ammonium, potassium acrylate, etc.) are also used. These binders can be used in combination of two or more.

  In the present invention, gelatin and gelatin derivatives, or polyvinyl alcohol or derivatives thereof can be preferably used.

  Polymers dispersed in an aqueous solvent include natural rubber latex, styrene butadiene rubber, butadiene rubber, nitrile rubber, chloroprene rubber, isoprene rubber and other latexes, polyisocyanate, epoxy, acrylic, silicone, polyurethane, Examples thereof include a thermosetting resin in which urea, phenol, formaldehyde, epoxy-polyamide, melamine, alkyd resin, vinyl resin and the like are dispersed in an aqueous solvent. Of these polymers, it is preferable to use an aqueous polyurethane resin described in JP-A-10-76621.

  In the present invention, “substantially insoluble in an electrolyte solvent” is defined as a state in which the dissolved amount per kg of electrolyte solvent is 0 g or more and 10 g or less at a temperature of −20 ° C. to 120 ° C. The amount of dissolution can be determined by a known method such as a component determination method using a chromatogram or a gas chromatogram.

  In the present invention, the water mixture of the water-based polymer and the white pigment is preferably in the form in which the white pigment is dispersed in water according to a known dispersion method. The mixing ratio of the water-based polymer / white pigment is preferably 1 to 0.01, more preferably 0.3 to 0.05 in terms of volume ratio.

  In the present invention, the medium for applying the water mixture of the water-based polymer and the white pigment may be at any position as long as it is on the component between the counter electrodes of the display element, but at least one electrode surface of the counter electrode It is preferable to apply on top. As a method for applying to a medium, for example, a coating method, a liquid spraying method, a spraying method via a gas phase, a method of flying droplets using vibration of a piezoelectric element, for example, a piezoelectric inkjet head, Examples thereof include a bubble jet (registered trademark) type ink jet head that causes droplets to fly using a thermal head that uses bumping, and a spray type that sprays liquid by air pressure or liquid pressure.

  The coating method can be appropriately selected from known coating methods. For example, an air doctor coater, blade coater, rod coater, knife coater, squeeze coater, impregnation coater, reverse roller coater, transfer roller coater, curtain coater, double coater Examples include roller coaters, slide hopper coaters, gravure coaters, kiss roll coaters, bead coaters, cast coaters, spray coaters, calendar coaters, and extrusion coaters.

  Drying of the water mixture of the aqueous compound and the white pigment applied on the medium may be performed by any method as long as water can be evaporated. For example, heating from a heat source, a heating method using infrared light, a heating method using electromagnetic induction, and the like can be given. Further, water evaporation may be performed under reduced pressure.

  The porous as used in the present invention means that a water mixture of the water-based polymer and the white pigment is applied on an electrode and dried to form a porous white scattering material, and then silver or silver is formed on the scattering material. After applying an electrolyte solution containing the compound contained in the chemical structure, it can be sandwiched between the counter electrodes, giving a potential difference between the counter electrodes, causing a silver dissolution precipitation reaction, and ionic species can move between the electrodes Says the penetration state.

  In the display element of the present invention, it is desirable to carry out a curing reaction of the water-based polymer with a curing agent during or after application and drying of the water mixture described above.

  Examples of the hardener used in the present invention include, for example, U.S. Pat. No. 4,678,739, column 41, 4,791,042, JP-A-59-116655, and 62-245261. No. 61-18942, 61-249054, 61-245153, JP-A-4-218044, and the like. More specifically, aldehyde hardeners (formaldehyde, etc.), aziridine hardeners, epoxy hardeners, vinyl sulfone hardeners (N, N'-ethylene-bis (vinylsulfonylacetamide) Ethane, etc.), N-methylol hardeners (dimethylolurea, etc.), boric acid, metaboric acid or polymer hardeners (compounds described in JP-A-62-234157). When gelatin is used as the aqueous polymer, it is preferable to use a vinyl sulfone type hardener or a chlorotriazine type hardener alone or in combination. Moreover, when using polyvinyl alcohol, it is preferable to use boron-containing compounds such as boric acid and metaboric acid.

  These hardeners are used in an amount of 0.001 to 1 g, preferably 0.005 to 0.5 g, per 1 g of the water-based polymer. In addition, it is possible to perform heat treatment and humidity adjustment during the curing reaction in order to increase the film strength.

[Compounds represented by general formulas (1) to (4)]
In the display element of the present invention, the electrolyte is composed of at least one compound represented by the general formula (1) or (2) and a compound represented by the general formula (3) or the general formula (4). It is preferable to contain at least one kind.

  First, the compound represented by the general formula (1) according to the present invention will be described.

In the general formula (1), L represents an oxygen atom or CH ₂ , and R _{1 to} R ₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like as aryl groups. Examples of the cycloalkyl group such as phenyl group, naphthyl group and the like include, for example, a cyclopentyl group, cyclohexyl group and the like, an alkoxyalkyl group, for example, a β-methoxyethyl group, a γ-methoxypropyl group and the like, as an alkoxy group, Examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group.

  Specific examples of the compound represented by the general formula (1) according to the present invention are shown below, but the present invention is not limited to these exemplified compounds.

  Next, the compound represented by formula (2) according to the present invention will be described.

In the general formula (2), R ₅ and R ₆ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group or an alkoxy group.

  Examples of alkyl groups include methyl, ethyl, propyl, isopropyl, tert-butyl, pentyl, hexyl, octyl, dodecyl, tridecyl, tetradecyl, pentadecyl, and the like as aryl groups. Examples of the cycloalkyl group such as phenyl group, naphthyl group and the like include, for example, a cyclopentyl group, cyclohexyl group and the like, an alkoxyalkyl group, for example, a β-methoxyethyl group, a γ-methoxypropyl group and the like, as an alkoxy group, Examples thereof include a methoxy group, an ethoxy group, a propyloxy group, a pentyloxy group, a hexyloxy group, an octyloxy group, and a dodecyloxy group.

  Hereinafter, although the specific example of a compound represented by General formula (2) which concerns on this invention is shown, in this invention, it is not limited only to these illustrated compounds.

  Among the compounds represented by the general formula (1) and the general formula (2) exemplified above, the exemplary compounds (1-1), (1-2), and (2-3) are particularly preferable.

  The compounds represented by the general formulas (1) and (2) according to the present invention are one type of electrolyte solvent. However, in the display element of the present invention, another solvent is used as long as the object effects of the present invention are not impaired. Can be used together. Specifically, tetramethylurea, sulfolane, dimethyl sulfoxide, 1,3-dimethyl-2-imidazolidinone, 2- (N-methyl) -2-pyrrolidinone, hexamethylphosphortriamide, N-methylpropionamide, N, N-dimethylacetamide, N-methylacetamide, N, N dimethylformamide, N-methylformamide, butyronitrile, propionitrile, acetonitrile, acetylacetone, 4-methyl-2-pentanone, 2-butanol, 1-butanol, 2 -Propanol, 1-propanol, ethanol, methanol, acetic anhydride, ethyl acetate, ethyl propionate, dimethoxyethane, diethoxyfuran, tetrahydrofuran, ethylene glycol, diethylene glycol, triethylene glycol monobuty Ether, water and the like. Among these solvents, it is preferable to include at least one solvent having a freezing point of −20 ° C. or lower and a boiling point of 120 ° C. or higher.

  Furthermore, as a solvent which can be used in the present invention, J.P. A. Riddick, W.M. B. Bunger, T.A. K. Sakano, “Organic Solvents”, 4th ed. , John Wiley & Sons (1986). Marcus, “Ion Solvation”, John Wiley & Sons (1985), C.I. Reichardt, “Solvents and Solvent Effects in Chemistry”, 2nd ed. VCH (1988), G .; J. et al. Janz, R.A. P. T.A. Tomkins, “Nonqueous Electrical Handsbook”, Vol. 1, Academic Press (1972).

  In the present invention, the electrolyte solvent may be a single type or a mixture of solvents, but a mixed solvent containing ethylene carbonate is preferred. The addition amount of ethylene carbonate is preferably 10% by mass or more and 90% by mass or less of the total electrolyte solvent mass. A particularly preferable electrolyte solvent is a mixed solvent having a mass ratio of propylene carbonate / ethylene carbonate of 7/3 to 3/7. When the propylene carbonate ratio is larger than 7/3, the ionic conductivity is inferior and the response speed is lowered. When the propylene carbonate ratio is smaller than 3/7, the electrolyte tends to be deposited at a low temperature.

  In the display element of the present invention, it is preferable to use the compound represented by the general formula (3) or (4) together with the compound represented by the general formula (1) or (2).

In the general formula (3), R ₇ and R ₈ each represent a substituted or unsubstituted hydrocarbon group, and these include a linear group or a branched group. Further, these hydrocarbon groups may contain one or more nitrogen atoms, oxygen atoms, phosphorus atoms, sulfur atoms, and halogen atoms. However, when a ring containing an S atom is formed, an aromatic group is not taken. Each element adjacent to the S atom is preferably a carbon atom.

  Examples of groups that can be substituted for the hydrocarbon group include amino groups, guanidino groups, quaternary ammonium groups, hydroxyl groups, halogen compounds, carboxylic acid groups, carboxylate groups, amide groups, sulfinic acid groups, sulfonic acid groups, and sulfates. Groups, phosphonic acid groups, phosphate groups, nitro groups, cyano groups and the like.

  Generally, in order to cause dissolution and precipitation of silver, it is necessary to solubilize silver in an electrolyte. For example, solubilize silver or a compound containing silver by coexisting with a compound containing a chemical structural species that interacts with silver, such as a coordinate bond with silver or a weak covalent bond with silver. It is common to use a means for converting to an object. As the chemical structural species, a halogen atom, a mercapto group, a carboxyl group, an imino group, and the like are known, but in the present invention, the thioether group is also useful as a silver solvent and has little influence on the coexisting compound, It is characterized by high solubility in solvents.

  Hereinafter, although the specific example of a compound represented by General formula (3) which concerns on this invention is shown, in this invention, it is not limited only to these illustrated compounds.

3-1: CH ₃ SCH ₂ CH ₂ OH
3-2: HOCH ₂ CH ₂ SCH ₂ CH ₂ OH
3-3: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
3-4: HOCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OH
3-5: HOCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ OH
3-6: HOCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OH
3-7: H ₃ CSCH ₂ CH ₂ COOH
3-8: HOOCCH ₂ SCH ₂ COOH
3-9: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ COOH
3-10: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ COOH
3-11: HOOCCH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ COOH
3-12: HOOCCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH (OH) CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ COOH
_{3-13: HOOCCH 2 CH 2 SCH 2} CH 2 SCH 2 CH (OH) CH (OH) CH 2 SCH 2 CH 2 SCH 2 CH 2 COOH
3-14: H ₃ CSCH ₂ CH ₂ CH ₂ NH ₂
3-15: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
3-16: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
3-17: H ₃ CSCH ₂ CH ₂ CH (NH ₂ ) COOH
3-18: H ₂ NCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ NH ₂
3-19: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
3-20: H ₂ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NH ₂
3-21: HOOC (NH ₂ ) CHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH (NH ₂ ) COOH
3-22: HOOC (NH ₂ ) CHCH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ CH (NH ₂ ) COOH
3-23: HOOC (NH ₂ ) CHCH ₂ OCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ OCH ₂ CH (NH ₂ ) COOH
3-24: H ₂ NC (═O) CH ₂ SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SCH ₂ C (═O) NH ₂
3-25: H ₂ NC (═O) CH ₂ SCH ₂ CH ₂ SCH ₂ C (═O) NH ₂
3-26: H ₂ NHNC (═O) CH ₂ SCH ₂ CH ₂ SCH ₂ C (═O) NHNH ₂
3-27: H ₃ CC (═O) NHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHC (═O) CH ₃
3-28: H ₂ NO ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ SO ₂ NH ₂
3-29: NaO ₃ SCH ₂ CH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ CH ₂ SO ₃ Na
3-30: H ₃ CSO ₂ NHCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ NHO ₂ SCH ₃
3-31: H ₂ NC (NH) SCH ₂ CH ₂ SC (═NH) NH ₂ .2HBr
3-32: H ₂ NC (═NH) SCH ₂ CH ₂ OCH ₂ CH ₂ OCH ₂ CH ₂ SC (═NH) NH ₂ .2HCl
_{3-33: H 2 NC (= NH} ) NHCH 2 CH 2 SCH 2 CH 2 SCH 2 CH 2 NHC (= NH) NH 2 · 2HBr
3-34: [(CH ₃ ) ₃ NCH ₂ CH ₂ SCH ₂ CH ₂ SCH ₂ CH ₂ N (CH ₃ ) ₃ ] 2 ⁺ · 2Cl ⁻

  Among the above-exemplified compounds, Exemplified Compound 3-2 is particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

  Next, the compound represented by formula (4) according to the present invention will be described.

In the general formula (4), M represents a hydrogen atom, a metal atom, or quaternary ammonium. Z represents an atom or an atomic group that forms a nitrogen-containing heterocycle with -C = N-. n represents an integer of 0 to 5, and R ₉ represents a hydrogen atom or a substituent. Substituents include halogen atoms, alkyl groups, aryl groups, alkylcarbonamide groups, arylcarbonamide groups, alkylsulfonamide groups, arylsulfonamide groups, alkoxy groups, aryloxy groups, alkylthio groups, arylthio groups, alkylcarbamoyl groups. , Arylcarbamoyl group, carbamoyl group, alkylsulfamoyl group, arylsulfamoyl group, sulfamoyl group, cyano group, alkylsulfonyl group, arylsulfonyl group, alkoxycarbonyl group, aryloxycarbonyl group, alkylcarbonyl group, arylcarbonyl group , an acyloxy group, a carboxyl group, a carbonyl group, a sulfonyl group, an amino group, a hydroxy group or a heterocyclic group, when n is 2 or more, each R ₉ may be the same, different It may be I, may form a condensed ring by combining to each other.

Examples of the metal atom represented by M in the general formula (4) include Li, Na, K, Mg, Ca, Zn, and Ag. Examples of the quaternary ammonium include NH ₄ , N (CH ₃ ) ₄ , N (C ₄ H ₉ ) ₄ , N (CH ₃ ) ₃ C ₁₂ H ₂₅ , N (CH ₃ ) ₃ C ₁₆ H ₃₃ , N (CH ₃ ) ₃ CH ₂ C ₆ H _{5 and the} like It is done.

  Examples of the nitrogen-containing heterocyclic ring formed by the atom or atomic group represented by Z in the general formula (4) include a tetrazole ring, a triazole ring, an imidazole ring, an oxadiazole ring, a thiadiazole ring, an indole ring, and an oxazole ring. Benzoxazole ring, benzimidazole ring, benzothiazole ring, benzoselenazole ring, naphthoxazole ring and the like, among which a triazole ring is preferable.

Examples of the halogen atom represented by R ₉ in the general formula (4) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group include methyl, ethyl, propyl, i- Examples include propyl, butyl, t-butyl, pentyl, cyclopentyl, hexyl, cyclohexyl, octyl, dodecyl, hydroxyethyl, methoxyethyl, trifluoromethyl, benzyl, etc. Examples of the aryl group include phenyl, naphthyl and the like. Examples of the alkylcarbonamide group include acetylamino, propionylamino, butyroylamino and the like. Examples of the arylcarbonamide group include benzoylamino and the like. Examples of the sulfonamide group include methanesulfonyl. Minosulfonyl, ethanesulfonylamino group, etc., and arylsulfonamide groups include, for example, benzenesulfonylamino group, toluenesulfonylamino group, etc., and alkoxy groups include methoxy group, ethoxy group, butoxy group, octyl. Examples include an oxy group, a dodecyloxy group, etc., examples of the aryloxy group include phenoxy and the like, examples of the alkylthio group include groups such as methylthio, ethylthio, butylthio, etc. For example, phenylthio group, tolylthio group and the like can be mentioned. Examples of the alkylcarbamoyl group include, for example, methylcarbamoyl, dimethylcarbamoyl, ethylcarbamoyl, diethylcarbamoyl, dibutylcarbamoyl, piperidylcarbamoyl, morpholylcarbacarbyl. Examples of the arylcarbamoyl group include phenylcarbamoyl, methylphenylcarbamoyl, ethylphenylcarbamoyl, and benzylphenylcarbamoyl. Examples of the alkylsulfamoyl group include methyl Examples include sulfamoyl, dimethylsulfamoyl, ethylsulfamoyl, diethylsulfamoyl, dibutylsulfamoyl, piperidylsulfamoyl, morpholylsulfamoyl and the like, and arylsulfamoyl group includes Examples thereof include phenylsulfamoyl, methylphenylsulfamoyl, ethylphenylsulfamoyl, benzylphenylsulfamoyl and the like. Examples of the alkylsulfonyl group include methanesulfonyl group, ethanesulfo group, and the like. Examples of the arylsulfonyl group include phenylsulfonyl, 4-chlorophenylsulfonyl, p-toluenesulfonyl, and the like. Examples of the alkoxycarbonyl group include methoxycarbonyl, ethoxycarbonyl, and butoxy. Examples of the aryloxycarbonyl group include phenoxycarbonyl and the like. Examples of the alkylcarbonyl group include groups such as acetyl, propionyl, butyroyl, and the arylcarbonyl group. Examples thereof include a benzoyl group, an alkylbenzoyl group, and the like. Examples of the acyloxy group include groups such as acetyloxy, propionyloxy, and butyroyloxy. Examples of the heterocyclic group include an oxazole ring. Thiazole ring, triazole ring, selenazole ring, tetrazole ring, oxadiazole ring, thiadiazole ring, thiazine ring, triazine ring, benzoxazole ring, benzthiazole ring, indolenine ring, benzselenazole ring, naphthothiazole ring, triazaind A lysine ring, a diazaindolizine ring, a tetraazaindolizine ring group, etc. are mentioned. These substituents further include those having a substituent.

  Next, although the preferable specific example of a compound represented by General formula (4) is shown, this invention is not limited to these compounds.

  Among the above-exemplified compounds, Exemplified Compounds 4-12 and 4-18 are particularly preferable from the viewpoint that the object and effects of the present invention can be exhibited.

[Halogen ion, silver ion concentration ratio]
In the display element of the present invention, the molar concentration of halogen ions or halogen atoms contained in the electrolyte is [X] (mol / kg), and silver contained in the electrolyte or the total silver of the compound containing silver in the chemical structure. When the molar concentration is [Ag] (mol / kg), it is preferable to satisfy the condition defined by the following formula (1).

Formula (1): 0 ≦ [X] / [Ag] ≦ 0.01
The halogen atom as used in the field of this invention means an iodine atom, a chlorine atom, a bromine atom, and a fluorine atom. When [X] / [Ag] is larger than 0.01, X ₂ is generated from X during the oxidation-reduction reaction of silver, and X ₂ easily cross-oxidizes with blackened silver to dissolve the blackened silver. Therefore, the molar concentration of halogen atoms is preferably as low as possible with respect to the molar concentration of silver. In the present invention, 0 ≦ [X] / [Ag] ≦ 0.001 is more preferable. In the case of adding halogen ions, the halogen species preferably have a total molar concentration of [I] <[Br] <[Cl] <[F] from the viewpoint of improving memory properties.

[Electrolyte-silver salt]
In the display element of the present invention, silver iodide, silver chloride, silver bromide, silver oxide, silver sulfide, silver citrate, silver acetate, silver behenate, silver p-toluenesulfonate, silver trifluoromethanesulfonate, mercapto A known silver salt compound such as a silver salt with an acid or a silver complex with iminodiacetic acid can be used. Among these, it is preferable to use, as a silver salt, a compound that does not have a nitrogen atom having coordination properties with halogen, carboxylic acid, or silver, and for example, silver p-toluenesulfonate is preferable.

  The silver ion concentration [Ag] 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 greater than 2 mol / kg, the solubility deteriorates, and precipitation tends to occur during low-temperature storage, which is disadvantageous. It is.

  In the display element of the present invention, in addition to the above-described constituent elements, various constituent layers can be provided as necessary.

[Porous electrode containing metal oxide]
In the display element of the present invention, a porous electrode containing a metal oxide can also be used.

  In the display element of the present invention, the surface of the counter electrode that is not on the image observation side is protected by a porous electrode containing a metal oxide, so that silver or silver on the surface that is not on the image observation side has a chemical structure. When the oxidation-reduction reaction of the compound contained therein is performed on or in the porous electrode containing the metal oxide, it is possible to expand the choice of types of electrodes that are not on the image observation side and improve the durability. .

  Examples of the metal oxide constituting the porous electrode according to the present invention include titanium oxide, silicon oxide, zinc oxide, tin oxide, Sn-doped indium oxide (ITO), antimony-doped tin oxide (ATO), and fluorine-doped tin oxide. (FTO), aluminum-doped zinc oxide and the like, or a mixture thereof.

The porous electrode is formed by binding or contacting a plurality of fine particles of the metal oxide. The average particle diameter of the metal oxide fine particles is preferably 5 nm to 10 μm, more preferably 20 nm to 1 μm. The specific surface area of the metal oxide fine particles is preferably ^{1 × 10 -3 ~1 × 10 2} m 2 / g by a simple BET method, more preferably at 1 × 10 ^-2 ~10m ² / g . In addition, the metal oxide fine particles may have any shape such as an indefinite shape, a needle shape, a spherical shape, or the like.

  As a method for forming or binding metal oxide fine particles, a known sol-gel method or sintering method can be employed. For example, (1) Journal of the Ceramic Society of Japan, 102, 2, p200 (1994), (2) Ceramics Association Magazine 90, 4, p157, (3) J. of Non-Cryst. Solids, 82, 400 (1986) and the like. In addition, a method of obtaining a porous electrode by dispersing titanium oxide dendrimer particles prepared by a vapor phase method on a solution and applying the particles on a substrate and drying at a temperature of about 120 to 150 ° C. to remove the solvent is used. You can also. The metal oxide fine particles are preferably bound, and preferably have a resistance of 0.1 g or more, preferably 1 g or more with a continuous load type surface property measuring instrument (for example, a scratch tester).

  Porous as used in the present invention refers to a penetrating state in which a porous electrode is disposed, a potential difference is applied between the counter electrodes, and a dissolution and precipitation reaction of silver can occur, and the ionic species can move within the porous electrode. Say.

(Electronic insulation layer)
In the display element of the present invention, an electrical insulating layer can be provided.

  The electronic insulating layer applicable to the present invention may be a layer having both ionic conductivity and electronic insulating properties. For example, a solid electrolyte membrane in which a polymer or salt having a polar group is formed into a film, electronic insulating properties And a porous solid body having a low relative dielectric constant, such as a silicon-containing compound, and the like.

  As a method for forming a porous film, a sintering method (fusing method) (using fine pores formed between particles by partially fusing polymer fine particles or inorganic particles by adding a binder, etc.), extraction method ( After forming a constituent layer with a solvent-soluble organic substance or inorganic substance and a binder that does not dissolve in the solvent, the organic substance or inorganic substance is dissolved with the solvent to obtain pores), and the polymer is heated or degassed Known forming methods such as a foaming method in which foaming is performed, a phase change method in which a mixture of polymers is phase-separated by operating a good solvent and a poor solvent, and a radiation irradiation method in which pores are formed by radiating various types of radiation Can be used. Specifically, JP-A-10-30181, JP-A-2003-107626, JP-B-7-95403, JP-A-2635715, JP-A-2894523, JP-A-2987474, JP-A-3066426, and JP-A-3464513. No. 3,483,464, No. 3535942, No. 30622203, and the like.

[Electrolyte material]
In the display element of the present invention, when the electrolyte is a liquid, the following compounds can be included in the electrolyte. KCl, KI, KBr, etc. as potassium compounds, LiBF ₄ , LiClO ₄ , LiPF ₆ , LiCF ₃ SO ₃ etc. as lithium compounds, tetraethylammonium perchlorate, tetrabutylammonium perchlorate, tetraethylammonium borofluoride as tetraalkylammonium compounds And tetrabutylammonium borofluoride and tetrabutylammonium halide. Moreover, the molten salt electrolyte composition described in paragraph numbers [0062] to [0081] of JP-A-2003-187881 can also be preferably used. Furthermore, a compound that becomes a redox pair such as I ⁻ / I ₃ ⁻ , Br ⁻ / Br ₃ ⁻ , and quinone / hydroquinone can be used.

  Further, when the supporting electrolyte is a solid, the following compounds exhibiting electron conductivity and ion conductivity can be contained in the electrolyte.

Vinyl fluoride polymer containing perfluorosulfonic acid, polythiophene, polyaniline, polypyrrole, triphenylamines, polyvinylcarbazoles, polymethylphenylsilanes, Cu ₂ S, Ag ₂ S, Cu ₂ Se, AgCrSe _2, etc. F-containing compounds such as chalcogenide, CaF ₂ , PbF ₂ , SrF ₂ , LaF ₃ , TlSn ₂ F ₅ , CeF ₃ , Li salts such as Li ₂ SO ₄ , Li ₄ SiO ₄ , Li ₃ PO ₄ , ZrO ₂ , CaO , Cd ₂ O ₃ , HfO ₂ , Y ₂ O ₃ , Nb ₂ O ₅ , WO ₃ , Bi ₂ O ₃ , AgBr, AgI, CuCl, CuBr, CuBr, CuI, LiI, LiBr, LiCl, LiAlCl ₄ , LiAlF _{4 , AgSBr, C 5 H 5 NHAg} 5 I 6, Rb 4 Cu 16 I 7 Cl 13, Rb 3 Cu 7 Cl 10, LiN, Li 5 NI 2 Compounds such as li ₆ NBr _3, and the like.

  Moreover, a gel electrolyte can also be used as the supporting electrolyte. When the electrolyte is non-aqueous, the oil gelling agents described in paragraphs [0057] to [0059] of JP-A No. 11-185836 can be used.

[Thickener added with electrolyte]
In the display element of the present invention, a thickener can be used for the electrolyte. For example, gelatin, gum arabic, poly (vinyl alcohol), hydroxyethyl cellulose, hydroxypropyl cellulose, cellulose acetate, cellulose acetate butyrate, poly ( Vinylpyrrolidone), poly (alkylene glycol), casein, starch, poly (acrylic acid), poly (methyl methacrylic acid), poly (vinyl chloride), poly (methacrylic acid), copoly (styrene-maleic anhydride), copoly ( Styrene-acrylonitrile), copoly (styrene-butadiene), poly (vinyl acetal) s (eg, poly (vinyl formal) and poly (vinyl butyral)), poly (esters), poly (urethanes), phenoxy resins, poly (PVC Redene), poly (epoxide) s, poly (carbonates), poly (vinyl acetate), cellulose esters, poly (amides), hydrophobic transparent binders such as polyvinyl butyral, cellulose acetate, cellulose acetate butyrate, polyester, Examples include polycarbonate, polyacrylic acid, polyurethane and the like.

  These thickeners may be used in combination of two or more. Moreover, the compound as described in pages 71-75 of Unexamined-Japanese-Patent No. 64-13546 can be mentioned. Among these, the compounds preferably used are polyvinyl alcohols, polyvinyl pyrrolidones, hydroxypropyl celluloses, and polyalkylene glycols from the viewpoint of compatibility with various additives and improvement in dispersion stability of white particles.

[Other additives]
Examples of the constituent layers of the display element of the present invention include auxiliary layers such as a protective layer, a filter layer, an antihalation layer, a crossover light cut layer, and a backing layer. Various chemical sensitizers, noble metal sensitizers, photosensitive dyes, supersensitizers, couplers, high boiling point solvents, antifoggants, stabilizers, development inhibitors, bleach accelerators, fixing accelerators described in Disclosure Agent, anti-color mixing agent, formalin scavenger, toning agent, hardening agent, surfactant, thickener, plasticizer, slip agent, UV absorber, irradiation prevention dye, filter light absorption dye, antibacterial agent, polymer latex Further, heavy metals, antistatic agents, matting agents and the like can be contained as necessary.

  These additives mentioned above are more specifically described in Research Disclosure (hereinafter abbreviated as RD) 176 Item / 17643 (December 1978), 184 Item / 18431 (August 1979), 187. Volume Item / 18716 (November 1979) and Volume 308 Item / 308119 (December 1989).

  The types of compounds and their descriptions shown in these three research disclosures are listed below.

Additive RD17643 RD18716 RD308119
Page Classification Page Classification Page Classification Chemical sensitizer 23 III 648 Upper right 96 III
Sensitizing dye 23 IV 648-649 996-8 IV
Desensitizing dye 23 IV 998 IV
Dye 25-26 VIII 649-650 1003 VIII
Development accelerator 29 XXI 648 Upper right Anti-fogging agent / stabilizer
24 IV 649 Upper right 1006-7 VI
Brightener 24 V 998 V
Hardener 26 X 651 Left 1004-5 X
Surfactant 26-7 XI 650 Right 1005-6 XI
Antistatic agent 27 XII 650 Right 1006-7 XIII
Plasticizer 27 XII 650 Right 1006 XII
Slipper 27 XII
Matting agent 28 XVI 650 Right 1008-9 XVI
Binder 26 XXII 1003-4 IX
Support 28 XVII 1009 XVII
〔Layer structure〕
The constituent layers between the counter electrodes of the display element of the present invention will be further described.

As a constituent layer according to the display element of the present invention, a constituent layer containing a hole transport material can be provided. Examples of hole transport materials include aromatic amines, triphenylene derivatives, oligothiophene compounds, polypyrroles, polyacetylene derivatives, polyphenylene vinylene derivatives, polythienylene vinylene derivatives, polythiophene derivatives, polyaniline derivatives, polytoluidine derivatives, CuI, CuSCN CuInSe ₂ , Cu (In, Ga) Se, CuGaSe ₂ , Cu ₂ O, CuS, CuGaS ₂ , CuInS ₂ , CuAlSe ₂ , GaP, NiO, CoO, FeO, Bi ₂ O ₃ , MoO ₂ , Cr ₂ O ₃ Etc.

〔substrate〕
Examples of the substrate that can be used in the present invention include polyolefins such as polyethylene and polypropylene, polycarbonates, cellulose acetate, polyethylene terephthalate, polyethylene dinaphthalene dicarboxylate, polyethylene naphthalates, polyvinyl chloride, polyimide, and polyvinyl acetal. Synthetic plastic films such as polystyrene can also be preferably used. Also preferred are syndiotactic polystyrenes. These can be obtained, for example, by the methods described in JP-A Nos. 62-117708, 1-46912 and 1-178505. Further, a metal substrate such as stainless steel, a paper support such as baryta paper and resin coated paper, and a support provided with a reflective layer on the plastic film, supported by JP-A-62-253195 (pages 29-31) The thing described as a body is mentioned. RDNo. 17643, page 28, ibid. No. 18716, page 647, right column to page 648, left column, and No. 307105, page 879 can also be preferably used. As these supports, those having resistance to curling due to heat treatment of Tg or less as in US Pat. No. 4,141,735 can be used. Further, the surface of these supports may be subjected to surface treatment for the purpose of improving the adhesion between the support and other constituent layers. In the present invention, glow discharge treatment, ultraviolet irradiation treatment, corona treatment, and flame treatment can be used as the surface treatment. Furthermore, the support body described in pages 44 to 149 of publicly known technology No. 5 (issued by Aztec Co., Ltd. on March 22, 1991) can also be used. Furthermore, RDNo. 308119, page 1009, Product Licensing Index, Volume 92, P108, “Supports”, and the like. In addition, a glass substrate or an epoxy resin kneaded with glass can be used.

〔electrode〕
In the display element of the present invention, it is preferable that at least one of the counter electrodes is a metal electrode. As the metal electrode, for example, known metal species such as platinum, gold, silver, copper, aluminum, zinc, nickel, titanium, bismuth, and alloys thereof can be used. The metal electrode is preferably a metal having a work function close to the redox potential of silver in the electrolyte. Above all, silver or a silver electrode having a silver content of 80% or more is advantageous for maintaining the reduced state of silver. Excellent in preventing dirt. As an electrode manufacturing method, an existing method such as an evaporation method, a printing method, an ink jet method, a spin coating method, or a CVD method can be used.

  In the display element of the present invention, it is preferable that at least one of the counter electrodes is a transparent electrode. The transparent electrode is not particularly limited as long as it is transparent and conducts electricity. For example, Indium Tin Oxide (ITO: Indium Tin Oxide), Indium Zinc Oxide (IZO: Indium Zinc Oxide), Fluorine Doped Tin Oxide (FTO), Indium Oxide, Zinc Oxide, Platinum, Gold, Silver, Rhodium, Copper, Examples thereof include chromium, carbon, aluminum, silicon, amorphous silicon, and BSO (Bismuth Silicon Oxide). In order to form the electrode in this manner, for example, an ITO film may be vapor-deposited on the substrate by a sputtering method or the like, or an ITO film may be formed on the entire surface and then patterned by a photolithography method. The surface resistance value is preferably 100Ω / □ or less, and more preferably 10Ω / □ or less. The thickness of the transparent electrode is not particularly limited, but is generally 0.1 to 20 μm.

[Other components of the display element]
In the display element of the present invention, a sealant, a columnar structure, and spacer particles can be used as necessary.

  Sealing agent is for sealing so that it does not leak out. It is also called sealing agent. Epoxy resin, urethane resin, acrylic resin, vinyl acetate resin, ene-thiol resin, silicone resin, modified resin A curing type such as a polymer resin, such as a thermosetting type, a photocurable type, a moisture curable type, and an anaerobic curable type can be used.

  The columnar structure provides strong self-holding (strength) between the substrates, for example, a columnar body, a quadrangular columnar body, an elliptical columnar body, a trapezoidal array arranged in a predetermined pattern such as a lattice arrangement. A columnar structure such as a columnar body can be given. Alternatively, stripes arranged at predetermined intervals may be used. This columnar structure is not a random array, but can maintain an appropriate interval between substrates, such as an evenly spaced array, an array in which the interval gradually changes, and an array in which a predetermined arrangement pattern is repeated at a constant period. The arrangement is preferably considered so as not to disturb the display. If the ratio of the area occupied by the columnar structure in the display area of the display element is 1 to 40%, a practically sufficient strength as a display element can be obtained.

  A spacer may be provided between the pair of substrates for uniformly maintaining a gap between the substrates. Examples of the spacer include a sphere made of resin or inorganic oxide. Further, a fixed spacer having a surface coated with a thermoplastic resin is also preferably used. In order to hold the gap between the substrates uniformly, only the columnar structure may be provided, but both the spacer and the columnar structure may be provided, or instead of the columnar structure, only the spacer is used as the space holding member. May be used. The diameter of the spacer is equal to or less than the height of the columnar structure, preferably equal to the height. When the columnar structure is not formed, the diameter of the spacer corresponds to the thickness of the cell gap.

[Screen printing]
In the present invention, a sealant, a columnar structure, an electrode pattern, and the like can be formed by a screen printing method. In the screen printing method, a screen on which a predetermined pattern is formed is placed on an electrode surface of a substrate, and a printing material (a composition for forming a columnar structure, such as a photocurable resin) is placed on the screen. Then, the squeegee is moved at a predetermined pressure, angle, and speed. Thereby, the printing material is transferred onto the substrate through the pattern of the screen. Next, the transferred material is heat-cured and dried. When the columnar structure is formed by the screen printing method, the resin material is not limited to a photocurable resin, and for example, a thermosetting resin such as an epoxy resin or an acrylic resin or a thermoplastic resin can also be used. As thermoplastic resins, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, polymethacrylate resin, polyacrylate resin, polystyrene resin, polyamide resin, polyethylene resin, polypropylene resin, fluororesin, polyurethane resin , Polyacrylonitrile resin, polyvinyl ether resin, polyvinyl ketone resin, polyether resin, polyvinyl pyrrolidone resin, saturated polyester resin, polycarbonate resin, chlorinated polyether resin and the like. The resin material is preferably used in the form of a paste by dissolving the resin in an appropriate solvent.

  After the columnar structure or the like is formed on the substrate as described above, a spacer is provided on at least one of the substrates as desired, and the pair of substrates are overlapped with the electrode formation surfaces facing each other to form an empty cell. . A pair of stacked substrates is heated while being pressed from both sides, whereby the display cells are obtained. In order to obtain a display element, an electrolyte composition may be injected between substrates by a vacuum injection method or the like. Alternatively, when the substrates are bonded together, the electrolyte composition may be dropped on one substrate, and the liquid crystal composition may be sealed simultaneously with the bonding of the substrates.

[Display element driving method]
In the display element of the present invention, it is preferable to perform a driving operation in which silver black is precipitated by applying a voltage equal to or higher than the precipitation overvoltage and silver black is continuously precipitated by applying a voltage lower than the precipitation overvoltage. By performing this driving operation, the writing energy can be reduced, the driving circuit load can be reduced, and the writing speed as a screen can be improved. It is generally known that overvoltage exists in electrode reactions in the electrochemical field. For example, overvoltage is described in detail on page 121 of “Introduction to Chemistry of Electron Transfer—Introduction to Electrochemistry” (published by Asakura Shoten in 1996). Since the display element of the present invention can also be regarded as an electrode reaction between the electrode and silver in the electrolyte, it can be easily understood that overvoltage exists even in silver dissolution precipitation. Since the magnitude of the overvoltage is governed by the exchange current density, it is possible to continue silver black precipitation by applying a voltage equal to or lower than the precipitation overvoltage after the formation of silver black as in the present invention. However, it is estimated that electron injection can be easily performed with little excess electric energy.

  The driving operation of the display element of the present invention may be simple matrix driving or active matrix driving. The simple matrix driving in the present invention is a driving method in which a current is sequentially applied to a circuit in which a positive line including a plurality of positive electrodes and a negative electrode line including a plurality of negative electrodes are opposed to each other in a vertical direction. Say that. By using simple matrix driving, there is an advantage that the circuit configuration and driving IC can be simplified and manufactured at low cost. The active matrix drive is a system in which scanning lines, data lines, and current supply lines are formed in a grid pattern, and are driven by TFT circuits provided in each grid pattern. Since switching can be performed for each pixel, there are merits such as gradation and memory function. For example, a circuit described in FIG. 5 of JP-A-2004-29327 can be used.

[Product application]
The display element of the present invention can be used in an electronic book field, an ID card field, a public field, a traffic field, a broadcast field, a payment field, a distribution logistics field, and the like. Specifically, keys for doors, student ID cards, employee ID cards, various membership cards, convenience store cards, department store cards, vending machine cards, gas station cards, subway and railway cards, bus cards, Cash cards, credit cards, highway cards, driver's licenses, hospital examination cards, electronic medical records, health insurance cards, Basic Resident Registers, passports, electronic books, etc.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. In addition, although the display of "part" or "%" is used in an Example, unless otherwise indicated, "part by mass" or "mass%" is represented.

Example 1
<< Production of display element >>
[Production of Display Element 1]
(Preparation of electrolyte 1)
In 2.5 g of dimethyl sulfoxide, 90 mg of sodium iodide and 75 mg of silver iodide were added and completely dissolved, and then 150 mg of polyvinylpyrrolidone (average molecular weight 15000) was added and stirred for 1 hour while heating to 120 ° C. Liquid 1 was obtained.

(Production of electrode 1)
An ITO film having a pitch of 145 μm and an electrode width of 130 μm was formed in a stripe shape on a glass substrate having a thickness of 1.5 mm and a size of 2 cm × 4 cm to obtain a transparent electrode (electrode 1).

(Preparation of electrode 2)
Using a known method, a silver-palladium electrode (electrode 2) having an electrode thickness of 0.8 μm, a pitch of 145 μm, and an electrode interval of 130 μm is formed on a glass substrate having a thickness of 1.5 mm and a size of 2 cm × 4 cm, An electrode 2 was obtained.

(Preparation of electrode 3)
Polyvinyl alcohol (average polymerization degree 3500, saponification degree 87%) 2 on the periphery 2 of the electrode 2 bordered with an olefin-based sealant containing 10% glass spherical beads having an average particle diameter of 40 μm as a volume fraction 2 100 μm of a mixed solution in which 20% by mass of titanium oxide is dispersed with an ultrasonic disperser in an isopropanol solution containing 5% by mass, and then dried at 15 ° C. for 30 minutes to evaporate the solvent. The electrode 3 was produced by drying for 1 hour.

(Production of display element)
The electrodes 3 and 1 were bonded together so that the striped electrodes were orthogonal to each other, and then heated and pressed to produce an empty cell. The electrolytic solution 1 was vacuum-injected into the empty cell, and the injection port was sealed with an epoxy-based ultraviolet curable resin to produce the display element 1.

[Production of Display Element 2]
Display element 2 was produced in the same manner as display element 1 except that 0.1 g of the exemplified compound (4-12) was added to electrolyte solution 1 of display element 1.

[Production of Display Element 3]
Display element 3 was produced in the same manner as display element 1 except that 0.1 g of (A-2) was added to electrolytic solution 1 of display element 1.

(A-2) γ-mercaptopropyl-trimethoxysilane (Preparation of electrode 4)
Electrode 1 was immersed in an ethanol solution of 5 mM of exemplified compound (A-2) for 2 hours, and methanol was dried at 120 ° C. for 1 hour to prepare electrode 4.

[Production of Display Element 4]
A display element 4 was produced in the same manner as the display element 1 except that the electrode 1 of the display element 1 was changed to the electrode 4.

[Preparation of display element 5]
In the display element 4, the display element 5 was produced in the same manner as the display element 4 except that (A-2) used for producing the electrode 4 was changed to an equimolar amount (A-1).

(A-1) Triethoxysilyl-propylamino-triazine-dithiol [Preparation of Display Element 6]
Display element 6 was produced in the same manner as display element 5 except that dimethyl sulfoxide in the electrolyte solution of display element 5 was changed to propylene carbonate of the same mass, and sodium iodide was changed to an equimolar example compound (4-12). .

[Production of display element 7]
A display element 7 was produced in the same manner as the display element 6 except that the silver iodide in the electrolyte solution of the display element 6 was changed to equimolar silver p-toluenesulfonate.

<< Evaluation of display element: Evaluation of color tone fluctuation >>
For each of the manufactured display elements, after obtaining a driving condition such that the L ^* value in the D65 light source of the spectrocolorimeter CM-3700d manufactured by Konica Minolta Sensing Co., Ltd. is 65, whitening is performed under this driving condition. The L ^* value, a ^* value, and b ^* value were measured and designated as L ₁ , a ₁ , and b ₁ , respectively. Thereafter, whitening-blackening was driven 1000 times under the driving conditions, and then L ^* value, a ^* value, and b ^* value when whitening was performed again were measured to be L ₂ , a ₂ , and b ₂ , respectively. ΔE = [(L ₂ −L ₁ ) ² + (a ₂ −a ₁ ) ² + (b ₂ −b ₁ ) ² ] ^1/2 is calculated from the obtained measured values as an evaluation value of the color tone fluctuation, The obtained results are shown in Table 1. The smaller the value of ΔE, the smaller the color tone variation in repeated driving, and the better.

Example 2
A glass substrate having a thickness of 1.5 mm and a size of 2 cm × 4 cm was immersed in a pH 10 ammonium hydroxide solution for 1 hour to dry the water, and then subjected to surface treatment with a UV ozone apparatus. Then, this board | substrate was immersed in the ethanol solution of 5 millimoles exemplary compound (A-2) for 2 hours, and ethanol was dried at 120 degreeC for 1 hour. Next, the substrate was irradiated with UV light through a mask having a pitch of 145 μm and an electrode interval of 130 μm, and this substrate was immersed in a 0.1 M chloroauric acid solution and dried. It was observed that a stripe pattern was formed (electrode 5).

  When the same evaluation as in Example 1 was performed using the electrode 5 instead of the electrode 3 in Example 1, it was found that the effect of Example 1 could be improved by 10% on average.

  As is apparent from the results shown in Table 1 and the results of Example 2, it can be seen that the display element having the configuration defined by the present invention is excellent in that the color tone fluctuation after repeated driving is reduced.

Claims (8)

A display element that holds an electrolyte containing silver or a silver compound between counter electrodes and performs a driving operation of the counter electrode so as to cause dissolution and precipitation of silver, and includes at least one electrode of the counter electrodes Is bonded to the compound having a mercapto group represented by the general formula (I) through a siloxane bond (Si—O).
Formula (I) (R) _n -Si (A) _3-n- (B)
(Here, R represents an alkyl group having 8 or less carbon atoms, A represents an alkoxy group or a halogen atom, B represents a substituent containing an SH group, and n represents an integer of 0 to 2.) .) The display device according to claim 1, wherein the compound of the general formula (I) has a triazine ring. The electrolyte contains at least one compound represented by the following general formula (1) or (2) and at least one compound represented by the following general formula (3) or (4). The display element according to claim 1, wherein the display element is a display element.

[Wherein, L represents an oxygen atom or CH ₂ , and R _{1 to} R ₄ each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group, or an alkoxy group. ]

[Wherein, R ₅ and R ₆ each represent a hydrogen atom, an alkyl group, an alkenyl group, an aryl group, a cycloalkyl group, an alkoxyalkyl group or an alkoxy group. ]
General formula (3)
R ₇ -S-R ₈
[Wherein R ₇ and R ₈ each represents a substituted or unsubstituted hydrocarbon group. However, when a ring containing an S atom is formed, an aromatic group is not taken. ]

[Wherein, M represents a hydrogen atom, a metal atom or quaternary ammonium. Z represents an atom or an atomic group constituting a nitrogen-containing heterocycle together with -C = N-. n represents an integer of 0 to 5, and R ₉ represents a hydrogen atom or a substituent. ] The molar concentration of halogen ions or halogen atoms contained in the electrolyte was [X] (mol / kg), and the total molar concentration of silver or silver of the silver compound contained in the electrolyte was [Ag] (mol / kg). When satisfy | filling the conditions prescribed | regulated by the following Formula (1), The display element as described in any one of Claims 1-3 characterized by the above-mentioned.
Formula (1): 0 ≦ [X] / [Ag] ≦ 0.01 It is a manufacturing method of the display element as described in any one of Claims 1-4, Comprising: The solution containing the compound represented by general formula (I) is made to contact at least 1 type of electrode of a counter electrode, and general A method for producing a display element, wherein the compound represented by the formula (I) is bonded to the electrode through a siloxane bond (Si-O). A method of manufacturing a display element that holds an electrolyte containing silver or a silver compound between counter electrodes, and performs a driving operation of the counter electrode so as to cause dissolution and precipitation of silver.
A solution containing the compound represented by the general formula (I) is brought into contact with the substrate, and the substrate on which the compound represented by the general formula (I) is bonded through a siloxane bond (Si—O) is irradiated with light. A method for manufacturing a display element, wherein a region where a metal can be bonded and a region where a metal cannot be bonded are separated to produce at least one type of counter electrode.
Formula (I) (R) _n -Si (A) _3-n- (B)
(Here, R represents an alkyl group having 8 or less carbon atoms, A represents an alkoxy group or a halogen atom, B represents a substituent containing an SH group, and n represents an integer of 0 to 2.) .) The method for manufacturing a display element according to claim 6, wherein a solution containing metal is brought into contact with the substrate after the light irradiation, and the metal is bonded to a region where the metal can be bonded. The method for manufacturing a display element according to claim 7, wherein a plating process is performed on a substrate in which a metal is bonded to a region where the metal can be bonded, and a plating film is selectively formed in the light irradiation region.